## Coverage Report

#### Created: 2026-05-04 15:30

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    /home/liu/actions-runner/_work/ccv/ccv/lib/3rdparty/sqlite3/sqlite3.h

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    1
    /*
    2
    ** 2001-09-15
    3
    **
    4
    ** The author disclaims copyright to this source code.  In place of
    5
    ** a legal notice, here is a blessing:
    6
    **
    7
    **    May you do good and not evil.
    8
    **    May you find forgiveness for yourself and forgive others.
    9
    **    May you share freely, never taking more than you give.
    10
    **
    11
    *************************************************************************
    12
    ** This header file defines the interface that the SQLite library
    13
    ** presents to client programs.  If a C-function, structure, datatype,
    14
    ** or constant definition does not appear in this file, then it is
    15
    ** not a published API of SQLite, is subject to change without
    16
    ** notice, and should not be referenced by programs that use SQLite.
    17
    **
    18
    ** Some of the definitions that are in this file are marked as
    19
    ** "experimental".  Experimental interfaces are normally new
    20
    ** features recently added to SQLite.  We do not anticipate changes
    21
    ** to experimental interfaces but reserve the right to make minor changes
    22
    ** if experience from use "in the wild" suggest such changes are prudent.
    23
    **
    24
    ** The official C-language API documentation for SQLite is derived
    25
    ** from comments in this file.  This file is the authoritative source
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    ** on how SQLite interfaces are supposed to operate.
    27
    **
    28
    ** The name of this file under configuration management is "sqlite.h.in".
    29
    ** The makefile makes some minor changes to this file (such as inserting
    30
    ** the version number) and changes its name to "sqlite3.h" as
    31
    ** part of the build process.
    32
    */
    33
    #ifndef SQLITE3_H
    34
    #define SQLITE3_H
    35
    #include <stdarg.h>     /* Needed for the definition of va_list */
    36
    37
    /*
    38
    ** Make sure we can call this stuff from C++.
    39
    */
    40
    #ifdef __cplusplus
    41
    extern "C" {
    42
    #endif
    43
    44
    45
    /*
    46
    ** Facilitate override of interface linkage and calling conventions.
    47
    ** Be aware that these macros may not be used within this particular
    48
    ** translation of the amalgamation and its associated header file.
    49
    **
    50
    ** The SQLITE_EXTERN and SQLITE_API macros are used to instruct the
    51
    ** compiler that the target identifier should have external linkage.
    52
    **
    53
    ** The SQLITE_CDECL macro is used to set the calling convention for
    54
    ** public functions that accept a variable number of arguments.
    55
    **
    56
    ** The SQLITE_APICALL macro is used to set the calling convention for
    57
    ** public functions that accept a fixed number of arguments.
    58
    **
    59
    ** The SQLITE_STDCALL macro is no longer used and is now deprecated.
    60
    **
    61
    ** The SQLITE_CALLBACK macro is used to set the calling convention for
    62
    ** function pointers.
    63
    **
    64
    ** The SQLITE_SYSAPI macro is used to set the calling convention for
    65
    ** functions provided by the operating system.
    66
    **
    67
    ** Currently, the SQLITE_CDECL, SQLITE_APICALL, SQLITE_CALLBACK, and
    68
    ** SQLITE_SYSAPI macros are used only when building for environments
    69
    ** that require non-default calling conventions.
    70
    */
    71
    #ifndef SQLITE_EXTERN
    72
    # define SQLITE_EXTERN extern
    73
    #endif
    74
    #ifndef SQLITE_API
    75
    # define SQLITE_API
    76
    #endif
    77
    #ifndef SQLITE_CDECL
    78
    # define SQLITE_CDECL
    79
    #endif
    80
    #ifndef SQLITE_APICALL
    81
    # define SQLITE_APICALL
    82
    #endif
    83
    #ifndef SQLITE_STDCALL
    84
    # define SQLITE_STDCALL SQLITE_APICALL
    85
    #endif
    86
    #ifndef SQLITE_CALLBACK
    87
    # define SQLITE_CALLBACK
    88
    #endif
    89
    #ifndef SQLITE_SYSAPI
    90
    # define SQLITE_SYSAPI
    91
    #endif
    92
    93
    /*
    94
    ** These no-op macros are used in front of interfaces to mark those
    95
    ** interfaces as either deprecated or experimental.  New applications
    96
    ** should not use deprecated interfaces - they are supported for backwards
    97
    ** compatibility only.  Application writers should be aware that
    98
    ** experimental interfaces are subject to change in point releases.
    99
    **
    100
    ** These macros used to resolve to various kinds of compiler magic that
    101
    ** would generate warning messages when they were used.  But that
    102
    ** compiler magic ended up generating such a flurry of bug reports
    103
    ** that we have taken it all out and gone back to using simple
    104
    ** noop macros.
    105
    */
    106
    #define SQLITE_DEPRECATED
    107
    #define SQLITE_EXPERIMENTAL
    108
    109
    /*
    110
    ** Ensure these symbols were not defined by some previous header file.
    111
    */
    112
    #ifdef SQLITE_VERSION
    113
    # undef SQLITE_VERSION
    114
    #endif
    115
    #ifdef SQLITE_VERSION_NUMBER
    116
    # undef SQLITE_VERSION_NUMBER
    117
    #endif
    118
    119
    /*
    120
    ** CAPI3REF: Compile-Time Library Version Numbers
    121
    **
    122
    ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header
    123
    ** evaluates to a string literal that is the SQLite version in the
    124
    ** format "X.Y.Z" where X is the major version number (always 3 for
    125
    ** SQLite3) and Y is the minor version number and Z is the release number.)^
    126
    ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer
    127
    ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same
    128
    ** numbers used in [SQLITE_VERSION].)^
    129
    ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also
    130
    ** be larger than the release from which it is derived.  Either Y will
    131
    ** be held constant and Z will be incremented or else Y will be incremented
    132
    ** and Z will be reset to zero.
    133
    **
    134
    ** Since [version 3.6.18] ([dateof:3.6.18]),
    135
    ** SQLite source code has been stored in the
    136
    ** <a href="http://fossil-scm.org/">Fossil configuration management
    137
    ** system</a>.  ^The SQLITE_SOURCE_ID macro evaluates to
    138
    ** a string which identifies a particular check-in of SQLite
    139
    ** within its configuration management system.  ^The SQLITE_SOURCE_ID
    140
    ** string contains the date and time of the check-in (UTC) and a SHA1
    141
    ** or SHA3-256 hash of the entire source tree.  If the source code has
    142
    ** been edited in any way since it was last checked in, then the last
    143
    ** four hexadecimal digits of the hash may be modified.
    144
    **
    145
    ** See also: [sqlite3_libversion()],
    146
    ** [sqlite3_libversion_number()], [sqlite3_sourceid()],
    147
    ** [sqlite_version()] and [sqlite_source_id()].
    148
    */
    149
    #define SQLITE_VERSION        "3.50.3"
    150
    #define SQLITE_VERSION_NUMBER 3050003
    151
    #define SQLITE_SOURCE_ID      "2025-07-17 13:25:10 3ce993b8657d6d9deda380a93cdd6404a8c8ba1b185b2bc423703e41ae5f2543"
    152
    153
    /*
    154
    ** CAPI3REF: Run-Time Library Version Numbers
    155
    ** KEYWORDS: sqlite3_version sqlite3_sourceid
    156
    **
    157
    ** These interfaces provide the same information as the [SQLITE_VERSION],
    158
    ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
    159
    ** but are associated with the library instead of the header file.  ^(Cautious
    160
    ** programmers might include assert() statements in their application to
    161
    ** verify that values returned by these interfaces match the macros in
    162
    ** the header, and thus ensure that the application is
    163
    ** compiled with matching library and header files.
    164
    **
    165
    ** <blockquote><pre>
    166
    ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
    167
    ** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 );
    168
    ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
    169
    ** </pre></blockquote>)^
    170
    **
    171
    ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION]
    172
    ** macro.  ^The sqlite3_libversion() function returns a pointer to the
    173
    ** to the sqlite3_version[] string constant.  The sqlite3_libversion()
    174
    ** function is provided for use in DLLs since DLL users usually do not have
    175
    ** direct access to string constants within the DLL.  ^The
    176
    ** sqlite3_libversion_number() function returns an integer equal to
    177
    ** [SQLITE_VERSION_NUMBER].  ^(The sqlite3_sourceid() function returns
    178
    ** a pointer to a string constant whose value is the same as the
    179
    ** [SQLITE_SOURCE_ID] C preprocessor macro.  Except if SQLite is built
    180
    ** using an edited copy of [the amalgamation], then the last four characters
    181
    ** of the hash might be different from [SQLITE_SOURCE_ID].)^
    182
    **
    183
    ** See also: [sqlite_version()] and [sqlite_source_id()].
    184
    */
    185
    SQLITE_API SQLITE_EXTERN const char sqlite3_version[];
    186
    SQLITE_API const char *sqlite3_libversion(void);
    187
    SQLITE_API const char *sqlite3_sourceid(void);
    188
    SQLITE_API int sqlite3_libversion_number(void);
    189
    190
    /*
    191
    ** CAPI3REF: Run-Time Library Compilation Options Diagnostics
    192
    **
    193
    ** ^The sqlite3_compileoption_used() function returns 0 or 1
    194
    ** indicating whether the specified option was defined at
    195
    ** compile time.  ^The SQLITE_ prefix may be omitted from the
    196
    ** option name passed to sqlite3_compileoption_used().
    197
    **
    198
    ** ^The sqlite3_compileoption_get() function allows iterating
    199
    ** over the list of options that were defined at compile time by
    200
    ** returning the N-th compile time option string.  ^If N is out of range,
    201
    ** sqlite3_compileoption_get() returns a NULL pointer.  ^The SQLITE_
    202
    ** prefix is omitted from any strings returned by
    203
    ** sqlite3_compileoption_get().
    204
    **
    205
    ** ^Support for the diagnostic functions sqlite3_compileoption_used()
    206
    ** and sqlite3_compileoption_get() may be omitted by specifying the
    207
    ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time.
    208
    **
    209
    ** See also: SQL functions [sqlite_compileoption_used()] and
    210
    ** [sqlite_compileoption_get()] and the [compile_options pragma].
    211
    */
    212
    #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
    213
    SQLITE_API int sqlite3_compileoption_used(const char *zOptName);
    214
    SQLITE_API const char *sqlite3_compileoption_get(int N);
    215
    #else
    216
    # define sqlite3_compileoption_used(X) 0
    217
    # define sqlite3_compileoption_get(X)  ((void*)0)
    218
    #endif
    219
    220
    /*
    221
    ** CAPI3REF: Test To See If The Library Is Threadsafe
    222
    **
    223
    ** ^The sqlite3_threadsafe() function returns zero if and only if
    224
    ** SQLite was compiled with mutexing code omitted due to the
    225
    ** [SQLITE_THREADSAFE] compile-time option being set to 0.
    226
    **
    227
    ** SQLite can be compiled with or without mutexes.  When
    228
    ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes
    229
    ** are enabled and SQLite is threadsafe.  When the
    230
    ** [SQLITE_THREADSAFE] macro is 0,
    231
    ** the mutexes are omitted.  Without the mutexes, it is not safe
    232
    ** to use SQLite concurrently from more than one thread.
    233
    **
    234
    ** Enabling mutexes incurs a measurable performance penalty.
    235
    ** So if speed is of utmost importance, it makes sense to disable
    236
    ** the mutexes.  But for maximum safety, mutexes should be enabled.
    237
    ** ^The default behavior is for mutexes to be enabled.
    238
    **
    239
    ** This interface can be used by an application to make sure that the
    240
    ** version of SQLite that it is linking against was compiled with
    241
    ** the desired setting of the [SQLITE_THREADSAFE] macro.
    242
    **
    243
    ** This interface only reports on the compile-time mutex setting
    244
    ** of the [SQLITE_THREADSAFE] flag.  If SQLite is compiled with
    245
    ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but
    246
    ** can be fully or partially disabled using a call to [sqlite3_config()]
    247
    ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],
    248
    ** or [SQLITE_CONFIG_SERIALIZED].  ^(The return value of the
    249
    ** sqlite3_threadsafe() function shows only the compile-time setting of
    250
    ** thread safety, not any run-time changes to that setting made by
    251
    ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()
    252
    ** is unchanged by calls to sqlite3_config().)^
    253
    **
    254
    ** See the [threading mode] documentation for additional information.
    255
    */
    256
    SQLITE_API int sqlite3_threadsafe(void);
    257
    258
    /*
    259
    ** CAPI3REF: Database Connection Handle
    260
    ** KEYWORDS: {database connection} {database connections}
    261
    **
    262
    ** Each open SQLite database is represented by a pointer to an instance of
    263
    ** the opaque structure named "sqlite3".  It is useful to think of an sqlite3
    264
    ** pointer as an object.  The [sqlite3_open()], [sqlite3_open16()], and
    265
    ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
    266
    ** and [sqlite3_close_v2()] are its destructors.  There are many other
    267
    ** interfaces (such as
    268
    ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
    269
    ** [sqlite3_busy_timeout()] to name but three) that are methods on an
    270
    ** sqlite3 object.
    271
    */
    272
    typedef struct sqlite3 sqlite3;
    273
    274
    /*
    275
    ** CAPI3REF: 64-Bit Integer Types
    276
    ** KEYWORDS: sqlite_int64 sqlite_uint64
    277
    **
    278
    ** Because there is no cross-platform way to specify 64-bit integer types
    279
    ** SQLite includes typedefs for 64-bit signed and unsigned integers.
    280
    **
    281
    ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
    282
    ** The sqlite_int64 and sqlite_uint64 types are supported for backwards
    283
    ** compatibility only.
    284
    **
    285
    ** ^The sqlite3_int64 and sqlite_int64 types can store integer values
    286
    ** between -9223372036854775808 and +9223372036854775807 inclusive.  ^The
    287
    ** sqlite3_uint64 and sqlite_uint64 types can store integer values
    288
    ** between 0 and +18446744073709551615 inclusive.
    289
    */
    290
    #ifdef SQLITE_INT64_TYPE
    291
      typedef SQLITE_INT64_TYPE sqlite_int64;
    292
    # ifdef SQLITE_UINT64_TYPE
    293
        typedef SQLITE_UINT64_TYPE sqlite_uint64;
    294
    # else
    295
        typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
    296
    # endif
    297
    #elif defined(_MSC_VER) || defined(__BORLANDC__)
    298
      typedef __int64 sqlite_int64;
    299
      typedef unsigned __int64 sqlite_uint64;
    300
    #else
    301
      typedef long long int sqlite_int64;
    302
      typedef unsigned long long int sqlite_uint64;
    303
    #endif
    304
    typedef sqlite_int64 sqlite3_int64;
    305
    typedef sqlite_uint64 sqlite3_uint64;
    306
    307
    /*
    308
    ** If compiling for a processor that lacks floating point support,
    309
    ** substitute integer for floating-point.
    310
    */
    311
    #ifdef SQLITE_OMIT_FLOATING_POINT
    312
    # define double sqlite3_int64
    313
    #endif
    314
    315
    /*
    316
    ** CAPI3REF: Closing A Database Connection
    317
    ** DESTRUCTOR: sqlite3
    318
    **
    319
    ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors
    320
    ** for the [sqlite3] object.
    321
    ** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if
    322
    ** the [sqlite3] object is successfully destroyed and all associated
    323
    ** resources are deallocated.
    324
    **
    325
    ** Ideally, applications should [sqlite3_finalize | finalize] all
    326
    ** [prepared statements], [sqlite3_blob_close | close] all [BLOB handles], and
    327
    ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated
    328
    ** with the [sqlite3] object prior to attempting to close the object.
    329
    ** ^If the database connection is associated with unfinalized prepared
    330
    ** statements, BLOB handlers, and/or unfinished sqlite3_backup objects then
    331
    ** sqlite3_close() will leave the database connection open and return
    332
    ** [SQLITE_BUSY]. ^If sqlite3_close_v2() is called with unfinalized prepared
    333
    ** statements, unclosed BLOB handlers, and/or unfinished sqlite3_backups,
    334
    ** it returns [SQLITE_OK] regardless, but instead of deallocating the database
    335
    ** connection immediately, it marks the database connection as an unusable
    336
    ** "zombie" and makes arrangements to automatically deallocate the database
    337
    ** connection after all prepared statements are finalized, all BLOB handles
    338
    ** are closed, and all backups have finished. The sqlite3_close_v2() interface
    339
    ** is intended for use with host languages that are garbage collected, and
    340
    ** where the order in which destructors are called is arbitrary.
    341
    **
    342
    ** ^If an [sqlite3] object is destroyed while a transaction is open,
    343
    ** the transaction is automatically rolled back.
    344
    **
    345
    ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)]
    346
    ** must be either a NULL
    347
    ** pointer or an [sqlite3] object pointer obtained
    348
    ** from [sqlite3_open()], [sqlite3_open16()], or
    349
    ** [sqlite3_open_v2()], and not previously closed.
    350
    ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer
    351
    ** argument is a harmless no-op.
    352
    */
    353
    SQLITE_API int sqlite3_close(sqlite3*);
    354
    SQLITE_API int sqlite3_close_v2(sqlite3*);
    355
    356
    /*
    357
    ** The type for a callback function.
    358
    ** This is legacy and deprecated.  It is included for historical
    359
    ** compatibility and is not documented.
    360
    */
    361
    typedef int (*sqlite3_callback)(void*,int,char**, char**);
    362
    363
    /*
    364
    ** CAPI3REF: One-Step Query Execution Interface
    365
    ** METHOD: sqlite3
    366
    **
    367
    ** The sqlite3_exec() interface is a convenience wrapper around
    368
    ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
    369
    ** that allows an application to run multiple statements of SQL
    370
    ** without having to use a lot of C code.
    371
    **
    372
    ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,
    373
    ** semicolon-separate SQL statements passed into its 2nd argument,
    374
    ** in the context of the [database connection] passed in as its 1st
    375
    ** argument.  ^If the callback function of the 3rd argument to
    376
    ** sqlite3_exec() is not NULL, then it is invoked for each result row
    377
    ** coming out of the evaluated SQL statements.  ^The 4th argument to
    378
    ** sqlite3_exec() is relayed through to the 1st argument of each
    379
    ** callback invocation.  ^If the callback pointer to sqlite3_exec()
    380
    ** is NULL, then no callback is ever invoked and result rows are
    381
    ** ignored.
    382
    **
    383
    ** ^If an error occurs while evaluating the SQL statements passed into
    384
    ** sqlite3_exec(), then execution of the current statement stops and
    385
    ** subsequent statements are skipped.  ^If the 5th parameter to sqlite3_exec()
    386
    ** is not NULL then any error message is written into memory obtained
    387
    ** from [sqlite3_malloc()] and passed back through the 5th parameter.
    388
    ** To avoid memory leaks, the application should invoke [sqlite3_free()]
    389
    ** on error message strings returned through the 5th parameter of
    390
    ** sqlite3_exec() after the error message string is no longer needed.
    391
    ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
    392
    ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
    393
    ** NULL before returning.
    394
    **
    395
    ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
    396
    ** routine returns SQLITE_ABORT without invoking the callback again and
    397
    ** without running any subsequent SQL statements.
    398
    **
    399
    ** ^The 2nd argument to the sqlite3_exec() callback function is the
    400
    ** number of columns in the result.  ^The 3rd argument to the sqlite3_exec()
    401
    ** callback is an array of pointers to strings obtained as if from
    402
    ** [sqlite3_column_text()], one for each column.  ^If an element of a
    403
    ** result row is NULL then the corresponding string pointer for the
    404
    ** sqlite3_exec() callback is a NULL pointer.  ^The 4th argument to the
    405
    ** sqlite3_exec() callback is an array of pointers to strings where each
    406
    ** entry represents the name of corresponding result column as obtained
    407
    ** from [sqlite3_column_name()].
    408
    **
    409
    ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer
    410
    ** to an empty string, or a pointer that contains only whitespace and/or
    411
    ** SQL comments, then no SQL statements are evaluated and the database
    412
    ** is not changed.
    413
    **
    414
    ** Restrictions:
    415
    **
    416
    ** <ul>
    417
    ** <li> The application must ensure that the 1st parameter to sqlite3_exec()
    418
    **      is a valid and open [database connection].
    419
    ** <li> The application must not close the [database connection] specified by
    420
    **      the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
    421
    ** <li> The application must not modify the SQL statement text passed into
    422
    **      the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
    423
    ** <li> The application must not dereference the arrays or string pointers
    424
    **       passed as the 3rd and 4th callback parameters after it returns.
    425
    ** </ul>
    426
    */
    427
    SQLITE_API int sqlite3_exec(
    428
      sqlite3*,                                  /* An open database */
    429
      const char *sql,                           /* SQL to be evaluated */
    430
      int (*callback)(void*,int,char**,char**),  /* Callback function */
    431
      void *,                                    /* 1st argument to callback */
    432
      char **errmsg                              /* Error msg written here */
    433
    );
    434
    435
    /*
    436
    ** CAPI3REF: Result Codes
    437
    ** KEYWORDS: {result code definitions}
    438
    **
    439
    ** Many SQLite functions return an integer result code from the set shown
    440
    ** here in order to indicate success or failure.
    441
    **
    442
    ** New error codes may be added in future versions of SQLite.
    443
    **
    444
    ** See also: [extended result code definitions]
    445
    */
    446
    125
    #define SQLITE_OK           0   /* Successful result */
    447
    /* beginning-of-error-codes */
    448
    #define SQLITE_ERROR        1   /* Generic error */
    449
    #define SQLITE_INTERNAL     2   /* Internal logic error in SQLite */
    450
    #define SQLITE_PERM         3   /* Access permission denied */
    451
    #define SQLITE_ABORT        4   /* Callback routine requested an abort */
    452
    #define SQLITE_BUSY         5   /* The database file is locked */
    453
    #define SQLITE_LOCKED       6   /* A table in the database is locked */
    454
    #define SQLITE_NOMEM        7   /* A malloc() failed */
    455
    #define SQLITE_READONLY     8   /* Attempt to write a readonly database */
    456
    #define SQLITE_INTERRUPT    9   /* Operation terminated by sqlite3_interrupt()*/
    457
    #define SQLITE_IOERR       10   /* Some kind of disk I/O error occurred */
    458
    0
    #define SQLITE_CORRUPT     11   /* The database disk image is malformed */
    459
    #define SQLITE_NOTFOUND    12   /* Unknown opcode in sqlite3_file_control() */
    460
    #define SQLITE_FULL        13   /* Insertion failed because database is full */
    461
    #define SQLITE_CANTOPEN    14   /* Unable to open the database file */
    462
    #define SQLITE_PROTOCOL    15   /* Database lock protocol error */
    463
    #define SQLITE_EMPTY       16   /* Internal use only */
    464
    #define SQLITE_SCHEMA      17   /* The database schema changed */
    465
    38
    #define SQLITE_TOOBIG      18   /* String or BLOB exceeds size limit */
    466
    #define SQLITE_CONSTRAINT  19   /* Abort due to constraint violation */
    467
    #define SQLITE_MISMATCH    20   /* Data type mismatch */
    468
    #define SQLITE_MISUSE      21   /* Library used incorrectly */
    469
    #define SQLITE_NOLFS       22   /* Uses OS features not supported on host */
    470
    #define SQLITE_AUTH        23   /* Authorization denied */
    471
    #define SQLITE_FORMAT      24   /* Not used */
    472
    #define SQLITE_RANGE       25   /* 2nd parameter to sqlite3_bind out of range */
    473
    #define SQLITE_NOTADB      26   /* File opened that is not a database file */
    474
    #define SQLITE_NOTICE      27   /* Notifications from sqlite3_log() */
    475
    #define SQLITE_WARNING     28   /* Warnings from sqlite3_log() */
    476
    151
    #define SQLITE_ROW         100  /* sqlite3_step() has another row ready */
    477
    48
    #define SQLITE_DONE        101  /* sqlite3_step() has finished executing */
    478
    /* end-of-error-codes */
    479
    480
    /*
    481
    ** CAPI3REF: Extended Result Codes
    482
    ** KEYWORDS: {extended result code definitions}
    483
    **
    484
    ** In its default configuration, SQLite API routines return one of 30 integer
    485
    ** [result codes].  However, experience has shown that many of
    486
    ** these result codes are too coarse-grained.  They do not provide as
    487
    ** much information about problems as programmers might like.  In an effort to
    488
    ** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8]
    489
    ** and later) include
    490
    ** support for additional result codes that provide more detailed information
    491
    ** about errors. These [extended result codes] are enabled or disabled
    492
    ** on a per database connection basis using the
    493
    ** [sqlite3_extended_result_codes()] API.  Or, the extended code for
    494
    ** the most recent error can be obtained using
    495
    ** [sqlite3_extended_errcode()].
    496
    */
    497
    #define SQLITE_ERROR_MISSING_COLLSEQ   (SQLITE_ERROR | (1<<8))
    498
    #define SQLITE_ERROR_RETRY             (SQLITE_ERROR | (2<<8))
    499
    #define SQLITE_ERROR_SNAPSHOT          (SQLITE_ERROR | (3<<8))
    500
    #define SQLITE_IOERR_READ              (SQLITE_IOERR | (1<<8))
    501
    #define SQLITE_IOERR_SHORT_READ        (SQLITE_IOERR | (2<<8))
    502
    #define SQLITE_IOERR_WRITE             (SQLITE_IOERR | (3<<8))
    503
    #define SQLITE_IOERR_FSYNC             (SQLITE_IOERR | (4<<8))
    504
    #define SQLITE_IOERR_DIR_FSYNC         (SQLITE_IOERR | (5<<8))
    505
    #define SQLITE_IOERR_TRUNCATE          (SQLITE_IOERR | (6<<8))
    506
    #define SQLITE_IOERR_FSTAT             (SQLITE_IOERR | (7<<8))
    507
    #define SQLITE_IOERR_UNLOCK            (SQLITE_IOERR | (8<<8))
    508
    #define SQLITE_IOERR_RDLOCK            (SQLITE_IOERR | (9<<8))
    509
    #define SQLITE_IOERR_DELETE            (SQLITE_IOERR | (10<<8))
    510
    #define SQLITE_IOERR_BLOCKED           (SQLITE_IOERR | (11<<8))
    511
    #define SQLITE_IOERR_NOMEM             (SQLITE_IOERR | (12<<8))
    512
    #define SQLITE_IOERR_ACCESS            (SQLITE_IOERR | (13<<8))
    513
    #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8))
    514
    #define SQLITE_IOERR_LOCK              (SQLITE_IOERR | (15<<8))
    515
    #define SQLITE_IOERR_CLOSE             (SQLITE_IOERR | (16<<8))
    516
    #define SQLITE_IOERR_DIR_CLOSE         (SQLITE_IOERR | (17<<8))
    517
    #define SQLITE_IOERR_SHMOPEN           (SQLITE_IOERR | (18<<8))
    518
    #define SQLITE_IOERR_SHMSIZE           (SQLITE_IOERR | (19<<8))
    519
    #define SQLITE_IOERR_SHMLOCK           (SQLITE_IOERR | (20<<8))
    520
    #define SQLITE_IOERR_SHMMAP            (SQLITE_IOERR | (21<<8))
    521
    #define SQLITE_IOERR_SEEK              (SQLITE_IOERR | (22<<8))
    522
    #define SQLITE_IOERR_DELETE_NOENT      (SQLITE_IOERR | (23<<8))
    523
    #define SQLITE_IOERR_MMAP              (SQLITE_IOERR | (24<<8))
    524
    #define SQLITE_IOERR_GETTEMPPATH       (SQLITE_IOERR | (25<<8))
    525
    #define SQLITE_IOERR_CONVPATH          (SQLITE_IOERR | (26<<8))
    526
    #define SQLITE_IOERR_VNODE             (SQLITE_IOERR | (27<<8))
    527
    #define SQLITE_IOERR_AUTH              (SQLITE_IOERR | (28<<8))
    528
    #define SQLITE_IOERR_BEGIN_ATOMIC      (SQLITE_IOERR | (29<<8))
    529
    #define SQLITE_IOERR_COMMIT_ATOMIC     (SQLITE_IOERR | (30<<8))
    530
    #define SQLITE_IOERR_ROLLBACK_ATOMIC   (SQLITE_IOERR | (31<<8))
    531
    #define SQLITE_IOERR_DATA              (SQLITE_IOERR | (32<<8))
    532
    #define SQLITE_IOERR_CORRUPTFS         (SQLITE_IOERR | (33<<8))
    533
    #define SQLITE_IOERR_IN_PAGE           (SQLITE_IOERR | (34<<8))
    534
    #define SQLITE_LOCKED_SHAREDCACHE      (SQLITE_LOCKED |  (1<<8))
    535
    #define SQLITE_LOCKED_VTAB             (SQLITE_LOCKED |  (2<<8))
    536
    #define SQLITE_BUSY_RECOVERY           (SQLITE_BUSY   |  (1<<8))
    537
    #define SQLITE_BUSY_SNAPSHOT           (SQLITE_BUSY   |  (2<<8))
    538
    #define SQLITE_BUSY_TIMEOUT            (SQLITE_BUSY   |  (3<<8))
    539
    #define SQLITE_CANTOPEN_NOTEMPDIR      (SQLITE_CANTOPEN | (1<<8))
    540
    #define SQLITE_CANTOPEN_ISDIR          (SQLITE_CANTOPEN | (2<<8))
    541
    #define SQLITE_CANTOPEN_FULLPATH       (SQLITE_CANTOPEN | (3<<8))
    542
    #define SQLITE_CANTOPEN_CONVPATH       (SQLITE_CANTOPEN | (4<<8))
    543
    #define SQLITE_CANTOPEN_DIRTYWAL       (SQLITE_CANTOPEN | (5<<8)) /* Not Used */
    544
    #define SQLITE_CANTOPEN_SYMLINK        (SQLITE_CANTOPEN | (6<<8))
    545
    #define SQLITE_CORRUPT_VTAB            (SQLITE_CORRUPT | (1<<8))
    546
    #define SQLITE_CORRUPT_SEQUENCE        (SQLITE_CORRUPT | (2<<8))
    547
    #define SQLITE_CORRUPT_INDEX           (SQLITE_CORRUPT | (3<<8))
    548
    #define SQLITE_READONLY_RECOVERY       (SQLITE_READONLY | (1<<8))
    549
    #define SQLITE_READONLY_CANTLOCK       (SQLITE_READONLY | (2<<8))
    550
    #define SQLITE_READONLY_ROLLBACK       (SQLITE_READONLY | (3<<8))
    551
    #define SQLITE_READONLY_DBMOVED        (SQLITE_READONLY | (4<<8))
    552
    #define SQLITE_READONLY_CANTINIT       (SQLITE_READONLY | (5<<8))
    553
    #define SQLITE_READONLY_DIRECTORY      (SQLITE_READONLY | (6<<8))
    554
    #define SQLITE_ABORT_ROLLBACK          (SQLITE_ABORT | (2<<8))
    555
    #define SQLITE_CONSTRAINT_CHECK        (SQLITE_CONSTRAINT | (1<<8))
    556
    #define SQLITE_CONSTRAINT_COMMITHOOK   (SQLITE_CONSTRAINT | (2<<8))
    557
    #define SQLITE_CONSTRAINT_FOREIGNKEY   (SQLITE_CONSTRAINT | (3<<8))
    558
    #define SQLITE_CONSTRAINT_FUNCTION     (SQLITE_CONSTRAINT | (4<<8))
    559
    #define SQLITE_CONSTRAINT_NOTNULL      (SQLITE_CONSTRAINT | (5<<8))
    560
    #define SQLITE_CONSTRAINT_PRIMARYKEY   (SQLITE_CONSTRAINT | (6<<8))
    561
    #define SQLITE_CONSTRAINT_TRIGGER      (SQLITE_CONSTRAINT | (7<<8))
    562
    #define SQLITE_CONSTRAINT_UNIQUE       (SQLITE_CONSTRAINT | (8<<8))
    563
    #define SQLITE_CONSTRAINT_VTAB         (SQLITE_CONSTRAINT | (9<<8))
    564
    #define SQLITE_CONSTRAINT_ROWID        (SQLITE_CONSTRAINT |(10<<8))
    565
    #define SQLITE_CONSTRAINT_PINNED       (SQLITE_CONSTRAINT |(11<<8))
    566
    #define SQLITE_CONSTRAINT_DATATYPE     (SQLITE_CONSTRAINT |(12<<8))
    567
    #define SQLITE_NOTICE_RECOVER_WAL      (SQLITE_NOTICE | (1<<8))
    568
    #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8))
    569
    #define SQLITE_NOTICE_RBU              (SQLITE_NOTICE | (3<<8))
    570
    #define SQLITE_WARNING_AUTOINDEX       (SQLITE_WARNING | (1<<8))
    571
    #define SQLITE_AUTH_USER               (SQLITE_AUTH | (1<<8))
    572
    #define SQLITE_OK_LOAD_PERMANENTLY     (SQLITE_OK | (1<<8))
    573
    #define SQLITE_OK_SYMLINK              (SQLITE_OK | (2<<8)) /* internal use only */
    574
    575
    /*
    576
    ** CAPI3REF: Flags For File Open Operations
    577
    **
    578
    ** These bit values are intended for use in the
    579
    ** 3rd parameter to the [sqlite3_open_v2()] interface and
    580
    ** in the 4th parameter to the [sqlite3_vfs.xOpen] method.
    581
    **
    582
    ** Only those flags marked as "Ok for sqlite3_open_v2()" may be
    583
    ** used as the third argument to the [sqlite3_open_v2()] interface.
    584
    ** The other flags have historically been ignored by sqlite3_open_v2(),
    585
    ** though future versions of SQLite might change so that an error is
    586
    ** raised if any of the disallowed bits are passed into sqlite3_open_v2().
    587
    ** Applications should not depend on the historical behavior.
    588
    **
    589
    ** Note in particular that passing the SQLITE_OPEN_EXCLUSIVE flag into
    590
    ** [sqlite3_open_v2()] does *not* cause the underlying database file
    591
    ** to be opened using O_EXCL.  Passing SQLITE_OPEN_EXCLUSIVE into
    592
    ** [sqlite3_open_v2()] has historically be a no-op and might become an
    593
    ** error in future versions of SQLite.
    594
    */
    595
    #define SQLITE_OPEN_READONLY         0x00000001  /* Ok for sqlite3_open_v2() */
    596
    #define SQLITE_OPEN_READWRITE        0x00000002  /* Ok for sqlite3_open_v2() */
    597
    #define SQLITE_OPEN_CREATE           0x00000004  /* Ok for sqlite3_open_v2() */
    598
    #define SQLITE_OPEN_DELETEONCLOSE    0x00000008  /* VFS only */
    599
    #define SQLITE_OPEN_EXCLUSIVE        0x00000010  /* VFS only */
    600
    #define SQLITE_OPEN_AUTOPROXY        0x00000020  /* VFS only */
    601
    #define SQLITE_OPEN_URI              0x00000040  /* Ok for sqlite3_open_v2() */
    602
    #define SQLITE_OPEN_MEMORY           0x00000080  /* Ok for sqlite3_open_v2() */
    603
    #define SQLITE_OPEN_MAIN_DB          0x00000100  /* VFS only */
    604
    #define SQLITE_OPEN_TEMP_DB          0x00000200  /* VFS only */
    605
    #define SQLITE_OPEN_TRANSIENT_DB     0x00000400  /* VFS only */
    606
    #define SQLITE_OPEN_MAIN_JOURNAL     0x00000800  /* VFS only */
    607
    #define SQLITE_OPEN_TEMP_JOURNAL     0x00001000  /* VFS only */
    608
    #define SQLITE_OPEN_SUBJOURNAL       0x00002000  /* VFS only */
    609
    #define SQLITE_OPEN_SUPER_JOURNAL    0x00004000  /* VFS only */
    610
    #define SQLITE_OPEN_NOMUTEX          0x00008000  /* Ok for sqlite3_open_v2() */
    611
    #define SQLITE_OPEN_FULLMUTEX        0x00010000  /* Ok for sqlite3_open_v2() */
    612
    #define SQLITE_OPEN_SHAREDCACHE      0x00020000  /* Ok for sqlite3_open_v2() */
    613
    #define SQLITE_OPEN_PRIVATECACHE     0x00040000  /* Ok for sqlite3_open_v2() */
    614
    #define SQLITE_OPEN_WAL              0x00080000  /* VFS only */
    615
    #define SQLITE_OPEN_NOFOLLOW         0x01000000  /* Ok for sqlite3_open_v2() */
    616
    #define SQLITE_OPEN_EXRESCODE        0x02000000  /* Extended result codes */
    617
    618
    /* Reserved:                         0x00F00000 */
    619
    /* Legacy compatibility: */
    620
    #define SQLITE_OPEN_MASTER_JOURNAL   0x00004000  /* VFS only */
    621
    622
    623
    /*
    624
    ** CAPI3REF: Device Characteristics
    625
    **
    626
    ** The xDeviceCharacteristics method of the [sqlite3_io_methods]
    627
    ** object returns an integer which is a vector of these
    628
    ** bit values expressing I/O characteristics of the mass storage
    629
    ** device that holds the file that the [sqlite3_io_methods]
    630
    ** refers to.
    631
    **
    632
    ** The SQLITE_IOCAP_ATOMIC property means that all writes of
    633
    ** any size are atomic.  The SQLITE_IOCAP_ATOMICnnn values
    634
    ** mean that writes of blocks that are nnn bytes in size and
    635
    ** are aligned to an address which is an integer multiple of
    636
    ** nnn are atomic.  The SQLITE_IOCAP_SAFE_APPEND value means
    637
    ** that when data is appended to a file, the data is appended
    638
    ** first then the size of the file is extended, never the other
    639
    ** way around.  The SQLITE_IOCAP_SEQUENTIAL property means that
    640
    ** information is written to disk in the same order as calls
    641
    ** to xWrite().  The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that
    642
    ** after reboot following a crash or power loss, the only bytes in a
    643
    ** file that were written at the application level might have changed
    644
    ** and that adjacent bytes, even bytes within the same sector are
    645
    ** guaranteed to be unchanged.  The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN
    646
    ** flag indicates that a file cannot be deleted when open.  The
    647
    ** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on
    648
    ** read-only media and cannot be changed even by processes with
    649
    ** elevated privileges.
    650
    **
    651
    ** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying
    652
    ** filesystem supports doing multiple write operations atomically when those
    653
    ** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and
    654
    ** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE].
    655
    **
    656
    ** The SQLITE_IOCAP_SUBPAGE_READ property means that it is ok to read
    657
    ** from the database file in amounts that are not a multiple of the
    658
    ** page size and that do not begin at a page boundary.  Without this
    659
    ** property, SQLite is careful to only do full-page reads and write
    660
    ** on aligned pages, with the one exception that it will do a sub-page
    661
    ** read of the first page to access the database header.
    662
    */
    663
    #define SQLITE_IOCAP_ATOMIC                 0x00000001
    664
    #define SQLITE_IOCAP_ATOMIC512              0x00000002
    665
    #define SQLITE_IOCAP_ATOMIC1K               0x00000004
    666
    #define SQLITE_IOCAP_ATOMIC2K               0x00000008
    667
    #define SQLITE_IOCAP_ATOMIC4K               0x00000010
    668
    #define SQLITE_IOCAP_ATOMIC8K               0x00000020
    669
    #define SQLITE_IOCAP_ATOMIC16K              0x00000040
    670
    #define SQLITE_IOCAP_ATOMIC32K              0x00000080
    671
    #define SQLITE_IOCAP_ATOMIC64K              0x00000100
    672
    #define SQLITE_IOCAP_SAFE_APPEND            0x00000200
    673
    #define SQLITE_IOCAP_SEQUENTIAL             0x00000400
    674
    #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN  0x00000800
    675
    #define SQLITE_IOCAP_POWERSAFE_OVERWRITE    0x00001000
    676
    #define SQLITE_IOCAP_IMMUTABLE              0x00002000
    677
    #define SQLITE_IOCAP_BATCH_ATOMIC           0x00004000
    678
    #define SQLITE_IOCAP_SUBPAGE_READ           0x00008000
    679
    680
    /*
    681
    ** CAPI3REF: File Locking Levels
    682
    **
    683
    ** SQLite uses one of these integer values as the second
    684
    ** argument to calls it makes to the xLock() and xUnlock() methods
    685
    ** of an [sqlite3_io_methods] object.  These values are ordered from
    686
    ** lest restrictive to most restrictive.
    687
    **
    688
    ** The argument to xLock() is always SHARED or higher.  The argument to
    689
    ** xUnlock is either SHARED or NONE.
    690
    */
    691
    #define SQLITE_LOCK_NONE          0       /* xUnlock() only */
    692
    #define SQLITE_LOCK_SHARED        1       /* xLock() or xUnlock() */
    693
    #define SQLITE_LOCK_RESERVED      2       /* xLock() only */
    694
    #define SQLITE_LOCK_PENDING       3       /* xLock() only */
    695
    #define SQLITE_LOCK_EXCLUSIVE     4       /* xLock() only */
    696
    697
    /*
    698
    ** CAPI3REF: Synchronization Type Flags
    699
    **
    700
    ** When SQLite invokes the xSync() method of an
    701
    ** [sqlite3_io_methods] object it uses a combination of
    702
    ** these integer values as the second argument.
    703
    **
    704
    ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
    705
    ** sync operation only needs to flush data to mass storage.  Inode
    706
    ** information need not be flushed. If the lower four bits of the flag
    707
    ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics.
    708
    ** If the lower four bits equal SQLITE_SYNC_FULL, that means
    709
    ** to use Mac OS X style fullsync instead of fsync().
    710
    **
    711
    ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags
    712
    ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL
    713
    ** settings.  The [synchronous pragma] determines when calls to the
    714
    ** xSync VFS method occur and applies uniformly across all platforms.
    715
    ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how
    716
    ** energetic or rigorous or forceful the sync operations are and
    717
    ** only make a difference on Mac OSX for the default SQLite code.
    718
    ** (Third-party VFS implementations might also make the distinction
    719
    ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the
    720
    ** operating systems natively supported by SQLite, only Mac OSX
    721
    ** cares about the difference.)
    722
    */
    723
    #define SQLITE_SYNC_NORMAL        0x00002
    724
    #define SQLITE_SYNC_FULL          0x00003
    725
    #define SQLITE_SYNC_DATAONLY      0x00010
    726
    727
    /*
    728
    ** CAPI3REF: OS Interface Open File Handle
    729
    **
    730
    ** An [sqlite3_file] object represents an open file in the
    731
    ** [sqlite3_vfs | OS interface layer].  Individual OS interface
    732
    ** implementations will
    733
    ** want to subclass this object by appending additional fields
    734
    ** for their own use.  The pMethods entry is a pointer to an
    735
    ** [sqlite3_io_methods] object that defines methods for performing
    736
    ** I/O operations on the open file.
    737
    */
    738
    typedef struct sqlite3_file sqlite3_file;
    739
    struct sqlite3_file {
    740
      const struct sqlite3_io_methods *pMethods;  /* Methods for an open file */
    741
    };
    742
    743
    /*
    744
    ** CAPI3REF: OS Interface File Virtual Methods Object
    745
    **
    746
    ** Every file opened by the [sqlite3_vfs.xOpen] method populates an
    747
    ** [sqlite3_file] object (or, more commonly, a subclass of the
    748
    ** [sqlite3_file] object) with a pointer to an instance of this object.
    749
    ** This object defines the methods used to perform various operations
    750
    ** against the open file represented by the [sqlite3_file] object.
    751
    **
    752
    ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element
    753
    ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method
    754
    ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed.  The
    755
    ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen]
    756
    ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element
    757
    ** to NULL.
    758
    **
    759
    ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
    760
    ** [SQLITE_SYNC_FULL].  The first choice is the normal fsync().
    761
    ** The second choice is a Mac OS X style fullsync.  The [SQLITE_SYNC_DATAONLY]
    762
    ** flag may be ORed in to indicate that only the data of the file
    763
    ** and not its inode needs to be synced.
    764
    **
    765
    ** The integer values to xLock() and xUnlock() are one of
    766
    ** <ul>
    767
    ** <li> [SQLITE_LOCK_NONE],
    768
    ** <li> [SQLITE_LOCK_SHARED],
    769
    ** <li> [SQLITE_LOCK_RESERVED],
    770
    ** <li> [SQLITE_LOCK_PENDING], or
    771
    ** <li> [SQLITE_LOCK_EXCLUSIVE].
    772
    ** </ul>
    773
    ** xLock() upgrades the database file lock.  In other words, xLock() moves the
    774
    ** database file lock in the direction NONE toward EXCLUSIVE. The argument to
    775
    ** xLock() is always one of SHARED, RESERVED, PENDING, or EXCLUSIVE, never
    776
    ** SQLITE_LOCK_NONE.  If the database file lock is already at or above the
    777
    ** requested lock, then the call to xLock() is a no-op.
    778
    ** xUnlock() downgrades the database file lock to either SHARED or NONE.
    779
    ** If the lock is already at or below the requested lock state, then the call
    780
    ** to xUnlock() is a no-op.
    781
    ** The xCheckReservedLock() method checks whether any database connection,
    782
    ** either in this process or in some other process, is holding a RESERVED,
    783
    ** PENDING, or EXCLUSIVE lock on the file.  It returns, via its output
    784
    ** pointer parameter, true if such a lock exists and false otherwise.
    785
    **
    786
    ** The xFileControl() method is a generic interface that allows custom
    787
    ** VFS implementations to directly control an open file using the
    788
    ** [sqlite3_file_control()] interface.  The second "op" argument is an
    789
    ** integer opcode.  The third argument is a generic pointer intended to
    790
    ** point to a structure that may contain arguments or space in which to
    791
    ** write return values.  Potential uses for xFileControl() might be
    792
    ** functions to enable blocking locks with timeouts, to change the
    793
    ** locking strategy (for example to use dot-file locks), to inquire
    794
    ** about the status of a lock, or to break stale locks.  The SQLite
    795
    ** core reserves all opcodes less than 100 for its own use.
    796
    ** A [file control opcodes | list of opcodes] less than 100 is available.
    797
    ** Applications that define a custom xFileControl method should use opcodes
    798
    ** greater than 100 to avoid conflicts.  VFS implementations should
    799
    ** return [SQLITE_NOTFOUND] for file control opcodes that they do not
    800
    ** recognize.
    801
    **
    802
    ** The xSectorSize() method returns the sector size of the
    803
    ** device that underlies the file.  The sector size is the
    804
    ** minimum write that can be performed without disturbing
    805
    ** other bytes in the file.  The xDeviceCharacteristics()
    806
    ** method returns a bit vector describing behaviors of the
    807
    ** underlying device:
    808
    **
    809
    ** <ul>
    810
    ** <li> [SQLITE_IOCAP_ATOMIC]
    811
    ** <li> [SQLITE_IOCAP_ATOMIC512]
    812
    ** <li> [SQLITE_IOCAP_ATOMIC1K]
    813
    ** <li> [SQLITE_IOCAP_ATOMIC2K]
    814
    ** <li> [SQLITE_IOCAP_ATOMIC4K]
    815
    ** <li> [SQLITE_IOCAP_ATOMIC8K]
    816
    ** <li> [SQLITE_IOCAP_ATOMIC16K]
    817
    ** <li> [SQLITE_IOCAP_ATOMIC32K]
    818
    ** <li> [SQLITE_IOCAP_ATOMIC64K]
    819
    ** <li> [SQLITE_IOCAP_SAFE_APPEND]
    820
    ** <li> [SQLITE_IOCAP_SEQUENTIAL]
    821
    ** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN]
    822
    ** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE]
    823
    ** <li> [SQLITE_IOCAP_IMMUTABLE]
    824
    ** <li> [SQLITE_IOCAP_BATCH_ATOMIC]
    825
    ** <li> [SQLITE_IOCAP_SUBPAGE_READ]
    826
    ** </ul>
    827
    **
    828
    ** The SQLITE_IOCAP_ATOMIC property means that all writes of
    829
    ** any size are atomic.  The SQLITE_IOCAP_ATOMICnnn values
    830
    ** mean that writes of blocks that are nnn bytes in size and
    831
    ** are aligned to an address which is an integer multiple of
    832
    ** nnn are atomic.  The SQLITE_IOCAP_SAFE_APPEND value means
    833
    ** that when data is appended to a file, the data is appended
    834
    ** first then the size of the file is extended, never the other
    835
    ** way around.  The SQLITE_IOCAP_SEQUENTIAL property means that
    836
    ** information is written to disk in the same order as calls
    837
    ** to xWrite().
    838
    **
    839
    ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill
    840
    ** in the unread portions of the buffer with zeros.  A VFS that
    841
    ** fails to zero-fill short reads might seem to work.  However,
    842
    ** failure to zero-fill short reads will eventually lead to
    843
    ** database corruption.
    844
    */
    845
    typedef struct sqlite3_io_methods sqlite3_io_methods;
    846
    struct sqlite3_io_methods {
    847
      int iVersion;
    848
      int (*xClose)(sqlite3_file*);
    849
      int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
    850
      int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
    851
      int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
    852
      int (*xSync)(sqlite3_file*, int flags);
    853
      int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);
    854
      int (*xLock)(sqlite3_file*, int);
    855
      int (*xUnlock)(sqlite3_file*, int);
    856
      int (*xCheckReservedLock)(sqlite3_file*, int *pResOut);
    857
      int (*xFileControl)(sqlite3_file*, int op, void *pArg);
    858
      int (*xSectorSize)(sqlite3_file*);
    859
      int (*xDeviceCharacteristics)(sqlite3_file*);
    860
      /* Methods above are valid for version 1 */
    861
      int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
    862
      int (*xShmLock)(sqlite3_file*, int offset, int n, int flags);
    863
      void (*xShmBarrier)(sqlite3_file*);
    864
      int (*xShmUnmap)(sqlite3_file*, int deleteFlag);
    865
      /* Methods above are valid for version 2 */
    866
      int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp);
    867
      int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p);
    868
      /* Methods above are valid for version 3 */
    869
      /* Additional methods may be added in future releases */
    870
    };
    871
    872
    /*
    873
    ** CAPI3REF: Standard File Control Opcodes
    874
    ** KEYWORDS: {file control opcodes} {file control opcode}
    875
    **
    876
    ** These integer constants are opcodes for the xFileControl method
    877
    ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
    878
    ** interface.
    879
    **
    880
    ** <ul>
    881
    ** <li>[[SQLITE_FCNTL_LOCKSTATE]]
    882
    ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging.  This
    883
    ** opcode causes the xFileControl method to write the current state of
    884
    ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
    885
    ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
    886
    ** into an integer that the pArg argument points to.
    887
    ** This capability is only available if SQLite is compiled with [SQLITE_DEBUG].
    888
    **
    889
    ** <li>[[SQLITE_FCNTL_SIZE_HINT]]
    890
    ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
    891
    ** layer a hint of how large the database file will grow to be during the
    892
    ** current transaction.  This hint is not guaranteed to be accurate but it
    893
    ** is often close.  The underlying VFS might choose to preallocate database
    894
    ** file space based on this hint in order to help writes to the database
    895
    ** file run faster.
    896
    **
    897
    ** <li>[[SQLITE_FCNTL_SIZE_LIMIT]]
    898
    ** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that
    899
    ** implements [sqlite3_deserialize()] to set an upper bound on the size
    900
    ** of the in-memory database.  The argument is a pointer to a [sqlite3_int64].
    901
    ** If the integer pointed to is negative, then it is filled in with the
    902
    ** current limit.  Otherwise the limit is set to the larger of the value
    903
    ** of the integer pointed to and the current database size.  The integer
    904
    ** pointed to is set to the new limit.
    905
    **
    906
    ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]]
    907
    ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
    908
    ** extends and truncates the database file in chunks of a size specified
    909
    ** by the user. The fourth argument to [sqlite3_file_control()] should
    910
    ** point to an integer (type int) containing the new chunk-size to use
    911
    ** for the nominated database. Allocating database file space in large
    912
    ** chunks (say 1MB at a time), may reduce file-system fragmentation and
    913
    ** improve performance on some systems.
    914
    **
    915
    ** <li>[[SQLITE_FCNTL_FILE_POINTER]]
    916
    ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
    917
    ** to the [sqlite3_file] object associated with a particular database
    918
    ** connection.  See also [SQLITE_FCNTL_JOURNAL_POINTER].
    919
    **
    920
    ** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]]
    921
    ** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer
    922
    ** to the [sqlite3_file] object associated with the journal file (either
    923
    ** the [rollback journal] or the [write-ahead log]) for a particular database
    924
    ** connection.  See also [SQLITE_FCNTL_FILE_POINTER].
    925
    **
    926
    ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]]
    927
    ** No longer in use.
    928
    **
    929
    ** <li>[[SQLITE_FCNTL_SYNC]]
    930
    ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and
    931
    ** sent to the VFS immediately before the xSync method is invoked on a
    932
    ** database file descriptor. Or, if the xSync method is not invoked
    933
    ** because the user has configured SQLite with
    934
    ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place
    935
    ** of the xSync method. In most cases, the pointer argument passed with
    936
    ** this file-control is NULL. However, if the database file is being synced
    937
    ** as part of a multi-database commit, the argument points to a nul-terminated
    938
    ** string containing the transactions super-journal file name. VFSes that
    939
    ** do not need this signal should silently ignore this opcode. Applications
    940
    ** should not call [sqlite3_file_control()] with this opcode as doing so may
    941
    ** disrupt the operation of the specialized VFSes that do require it.
    942
    **
    943
    ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]]
    944
    ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite
    945
    ** and sent to the VFS after a transaction has been committed immediately
    946
    ** but before the database is unlocked. VFSes that do not need this signal
    947
    ** should silently ignore this opcode. Applications should not call
    948
    ** [sqlite3_file_control()] with this opcode as doing so may disrupt the
    949
    ** operation of the specialized VFSes that do require it.
    950
    **
    951
    ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]]
    952
    ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic
    953
    ** retry counts and intervals for certain disk I/O operations for the
    954
    ** windows [VFS] in order to provide robustness in the presence of
    955
    ** anti-virus programs.  By default, the windows VFS will retry file read,
    956
    ** file write, and file delete operations up to 10 times, with a delay
    957
    ** of 25 milliseconds before the first retry and with the delay increasing
    958
    ** by an additional 25 milliseconds with each subsequent retry.  This
    959
    ** opcode allows these two values (10 retries and 25 milliseconds of delay)
    960
    ** to be adjusted.  The values are changed for all database connections
    961
    ** within the same process.  The argument is a pointer to an array of two
    962
    ** integers where the first integer is the new retry count and the second
    963
    ** integer is the delay.  If either integer is negative, then the setting
    964
    ** is not changed but instead the prior value of that setting is written
    965
    ** into the array entry, allowing the current retry settings to be
    966
    ** interrogated.  The zDbName parameter is ignored.
    967
    **
    968
    ** <li>[[SQLITE_FCNTL_PERSIST_WAL]]
    969
    ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the
    970
    ** persistent [WAL | Write Ahead Log] setting.  By default, the auxiliary
    971
    ** write ahead log ([WAL file]) and shared memory
    972
    ** files used for transaction control
    973
    ** are automatically deleted when the latest connection to the database
    974
    ** closes.  Setting persistent WAL mode causes those files to persist after
    975
    ** close.  Persisting the files is useful when other processes that do not
    976
    ** have write permission on the directory containing the database file want
    977
    ** to read the database file, as the WAL and shared memory files must exist
    978
    ** in order for the database to be readable.  The fourth parameter to
    979
    ** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
    980
    ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent
    981
    ** WAL mode.  If the integer is -1, then it is overwritten with the current
    982
    ** WAL persistence setting.
    983
    **
    984
    ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]]
    985
    ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the
    986
    ** persistent "powersafe-overwrite" or "PSOW" setting.  The PSOW setting
    987
    ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the
    988
    ** xDeviceCharacteristics methods. The fourth parameter to
    989
    ** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
    990
    ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage
    991
    ** mode.  If the integer is -1, then it is overwritten with the current
    992
    ** zero-damage mode setting.
    993
    **
    994
    ** <li>[[SQLITE_FCNTL_OVERWRITE]]
    995
    ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening
    996
    ** a write transaction to indicate that, unless it is rolled back for some
    997
    ** reason, the entire database file will be overwritten by the current
    998
    ** transaction. This is used by VACUUM operations.
    999
    **
    1000
    ** <li>[[SQLITE_FCNTL_VFSNAME]]
    1001
    ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of
    1002
    ** all [VFSes] in the VFS stack.  The names are of all VFS shims and the
    1003
    ** final bottom-level VFS are written into memory obtained from
    1004
    ** [sqlite3_malloc()] and the result is stored in the char* variable
    1005
    ** that the fourth parameter of [sqlite3_file_control()] points to.
    1006
    ** The caller is responsible for freeing the memory when done.  As with
    1007
    ** all file-control actions, there is no guarantee that this will actually
    1008
    ** do anything.  Callers should initialize the char* variable to a NULL
    1009
    ** pointer in case this file-control is not implemented.  This file-control
    1010
    ** is intended for diagnostic use only.
    1011
    **
    1012
    ** <li>[[SQLITE_FCNTL_VFS_POINTER]]
    1013
    ** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level
    1014
    ** [VFSes] currently in use.  ^(The argument X in
    1015
    ** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be
    1016
    ** of type "[sqlite3_vfs] **".  This opcodes will set *X
    1017
    ** to a pointer to the top-level VFS.)^
    1018
    ** ^When there are multiple VFS shims in the stack, this opcode finds the
    1019
    ** upper-most shim only.
    1020
    **
    1021
    ** <li>[[SQLITE_FCNTL_PRAGMA]]
    1022
    ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA]
    1023
    ** file control is sent to the open [sqlite3_file] object corresponding
    1024
    ** to the database file to which the pragma statement refers. ^The argument
    1025
    ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of
    1026
    ** pointers to strings (char**) in which the second element of the array
    1027
    ** is the name of the pragma and the third element is the argument to the
    1028
    ** pragma or NULL if the pragma has no argument.  ^The handler for an
    1029
    ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element
    1030
    ** of the char** argument point to a string obtained from [sqlite3_mprintf()]
    1031
    ** or the equivalent and that string will become the result of the pragma or
    1032
    ** the error message if the pragma fails. ^If the
    1033
    ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal
    1034
    ** [PRAGMA] processing continues.  ^If the [SQLITE_FCNTL_PRAGMA]
    1035
    ** file control returns [SQLITE_OK], then the parser assumes that the
    1036
    ** VFS has handled the PRAGMA itself and the parser generates a no-op
    1037
    ** prepared statement if result string is NULL, or that returns a copy
    1038
    ** of the result string if the string is non-NULL.
    1039
    ** ^If the [SQLITE_FCNTL_PRAGMA] file control returns
    1040
    ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means
    1041
    ** that the VFS encountered an error while handling the [PRAGMA] and the
    1042
    ** compilation of the PRAGMA fails with an error.  ^The [SQLITE_FCNTL_PRAGMA]
    1043
    ** file control occurs at the beginning of pragma statement analysis and so
    1044
    ** it is able to override built-in [PRAGMA] statements.
    1045
    **
    1046
    ** <li>[[SQLITE_FCNTL_BUSYHANDLER]]
    1047
    ** ^The [SQLITE_FCNTL_BUSYHANDLER]
    1048
    ** file-control may be invoked by SQLite on the database file handle
    1049
    ** shortly after it is opened in order to provide a custom VFS with access
    1050
    ** to the connection's busy-handler callback. The argument is of type (void**)
    1051
    ** - an array of two (void *) values. The first (void *) actually points
    1052
    ** to a function of type (int (*)(void *)). In order to invoke the connection's
    1053
    ** busy-handler, this function should be invoked with the second (void *) in
    1054
    ** the array as the only argument. If it returns non-zero, then the operation
    1055
    ** should be retried. If it returns zero, the custom VFS should abandon the
    1056
    ** current operation.
    1057
    **
    1058
    ** <li>[[SQLITE_FCNTL_TEMPFILENAME]]
    1059
    ** ^Applications can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control
    1060
    ** to have SQLite generate a
    1061
    ** temporary filename using the same algorithm that is followed to generate
    1062
    ** temporary filenames for TEMP tables and other internal uses.  The
    1063
    ** argument should be a char** which will be filled with the filename
    1064
    ** written into memory obtained from [sqlite3_malloc()].  The caller should
    1065
    ** invoke [sqlite3_free()] on the result to avoid a memory leak.
    1066
    **
    1067
    ** <li>[[SQLITE_FCNTL_MMAP_SIZE]]
    1068
    ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the
    1069
    ** maximum number of bytes that will be used for memory-mapped I/O.
    1070
    ** The argument is a pointer to a value of type sqlite3_int64 that
    1071
    ** is an advisory maximum number of bytes in the file to memory map.  The
    1072
    ** pointer is overwritten with the old value.  The limit is not changed if
    1073
    ** the value originally pointed to is negative, and so the current limit
    1074
    ** can be queried by passing in a pointer to a negative number.  This
    1075
    ** file-control is used internally to implement [PRAGMA mmap_size].
    1076
    **
    1077
    ** <li>[[SQLITE_FCNTL_TRACE]]
    1078
    ** The [SQLITE_FCNTL_TRACE] file control provides advisory information
    1079
    ** to the VFS about what the higher layers of the SQLite stack are doing.
    1080
    ** This file control is used by some VFS activity tracing [shims].
    1081
    ** The argument is a zero-terminated string.  Higher layers in the
    1082
    ** SQLite stack may generate instances of this file control if
    1083
    ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled.
    1084
    **
    1085
    ** <li>[[SQLITE_FCNTL_HAS_MOVED]]
    1086
    ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a
    1087
    ** pointer to an integer and it writes a boolean into that integer depending
    1088
    ** on whether or not the file has been renamed, moved, or deleted since it
    1089
    ** was first opened.
    1090
    **
    1091
    ** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]]
    1092
    ** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the
    1093
    ** underlying native file handle associated with a file handle.  This file
    1094
    ** control interprets its argument as a pointer to a native file handle and
    1095
    ** writes the resulting value there.
    1096
    **
    1097
    ** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]]
    1098
    ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging.  This
    1099
    ** opcode causes the xFileControl method to swap the file handle with the one
    1100
    ** pointed to by the pArg argument.  This capability is used during testing
    1101
    ** and only needs to be supported when SQLITE_TEST is defined.
    1102
    **
    1103
    ** <li>[[SQLITE_FCNTL_NULL_IO]]
    1104
    ** The [SQLITE_FCNTL_NULL_IO] opcode sets the low-level file descriptor
    1105
    ** or file handle for the [sqlite3_file] object such that it will no longer
    1106
    ** read or write to the database file.
    1107
    **
    1108
    ** <li>[[SQLITE_FCNTL_WAL_BLOCK]]
    1109
    ** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might
    1110
    ** be advantageous to block on the next WAL lock if the lock is not immediately
    1111
    ** available.  The WAL subsystem issues this signal during rare
    1112
    ** circumstances in order to fix a problem with priority inversion.
    1113
    ** Applications should <em>not</em> use this file-control.
    1114
    **
    1115
    ** <li>[[SQLITE_FCNTL_ZIPVFS]]
    1116
    ** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other
    1117
    ** VFS should return SQLITE_NOTFOUND for this opcode.
    1118
    **
    1119
    ** <li>[[SQLITE_FCNTL_RBU]]
    1120
    ** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by
    1121
    ** the RBU extension only.  All other VFS should return SQLITE_NOTFOUND for
    1122
    ** this opcode.
    1123
    **
    1124
    ** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]]
    1125
    ** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then
    1126
    ** the file descriptor is placed in "batch write mode", which
    1127
    ** means all subsequent write operations will be deferred and done
    1128
    ** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE].  Systems
    1129
    ** that do not support batch atomic writes will return SQLITE_NOTFOUND.
    1130
    ** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to
    1131
    ** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or
    1132
    ** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make
    1133
    ** no VFS interface calls on the same [sqlite3_file] file descriptor
    1134
    ** except for calls to the xWrite method and the xFileControl method
    1135
    ** with [SQLITE_FCNTL_SIZE_HINT].
    1136
    **
    1137
    ** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]]
    1138
    ** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write
    1139
    ** operations since the previous successful call to
    1140
    ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically.
    1141
    ** This file control returns [SQLITE_OK] if and only if the writes were
    1142
    ** all performed successfully and have been committed to persistent storage.
    1143
    ** ^Regardless of whether or not it is successful, this file control takes
    1144
    ** the file descriptor out of batch write mode so that all subsequent
    1145
    ** write operations are independent.
    1146
    ** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without
    1147
    ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
    1148
    **
    1149
    ** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]]
    1150
    ** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write
    1151
    ** operations since the previous successful call to
    1152
    ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back.
    1153
    ** ^This file control takes the file descriptor out of batch write mode
    1154
    ** so that all subsequent write operations are independent.
    1155
    ** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without
    1156
    ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
    1157
    **
    1158
    ** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]]
    1159
    ** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode is used to configure a VFS
    1160
    ** to block for up to M milliseconds before failing when attempting to
    1161
    ** obtain a file lock using the xLock or xShmLock methods of the VFS.
    1162
    ** The parameter is a pointer to a 32-bit signed integer that contains
    1163
    ** the value that M is to be set to. Before returning, the 32-bit signed
    1164
    ** integer is overwritten with the previous value of M.
    1165
    **
    1166
    ** <li>[[SQLITE_FCNTL_BLOCK_ON_CONNECT]]
    1167
    ** The [SQLITE_FCNTL_BLOCK_ON_CONNECT] opcode is used to configure the
    1168
    ** VFS to block when taking a SHARED lock to connect to a wal mode database.
    1169
    ** This is used to implement the functionality associated with
    1170
    ** SQLITE_SETLK_BLOCK_ON_CONNECT.
    1171
    **
    1172
    ** <li>[[SQLITE_FCNTL_DATA_VERSION]]
    1173
    ** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to
    1174
    ** a database file.  The argument is a pointer to a 32-bit unsigned integer.
    1175
    ** The "data version" for the pager is written into the pointer.  The
    1176
    ** "data version" changes whenever any change occurs to the corresponding
    1177
    ** database file, either through SQL statements on the same database
    1178
    ** connection or through transactions committed by separate database
    1179
    ** connections possibly in other processes. The [sqlite3_total_changes()]
    1180
    ** interface can be used to find if any database on the connection has changed,
    1181
    ** but that interface responds to changes on TEMP as well as MAIN and does
    1182
    ** not provide a mechanism to detect changes to MAIN only.  Also, the
    1183
    ** [sqlite3_total_changes()] interface responds to internal changes only and
    1184
    ** omits changes made by other database connections.  The
    1185
    ** [PRAGMA data_version] command provides a mechanism to detect changes to
    1186
    ** a single attached database that occur due to other database connections,
    1187
    ** but omits changes implemented by the database connection on which it is
    1188
    ** called.  This file control is the only mechanism to detect changes that
    1189
    ** happen either internally or externally and that are associated with
    1190
    ** a particular attached database.
    1191
    **
    1192
    ** <li>[[SQLITE_FCNTL_CKPT_START]]
    1193
    ** The [SQLITE_FCNTL_CKPT_START] opcode is invoked from within a checkpoint
    1194
    ** in wal mode before the client starts to copy pages from the wal
    1195
    ** file to the database file.
    1196
    **
    1197
    ** <li>[[SQLITE_FCNTL_CKPT_DONE]]
    1198
    ** The [SQLITE_FCNTL_CKPT_DONE] opcode is invoked from within a checkpoint
    1199
    ** in wal mode after the client has finished copying pages from the wal
    1200
    ** file to the database file, but before the *-shm file is updated to
    1201
    ** record the fact that the pages have been checkpointed.
    1202
    **
    1203
    ** <li>[[SQLITE_FCNTL_EXTERNAL_READER]]
    1204
    ** The EXPERIMENTAL [SQLITE_FCNTL_EXTERNAL_READER] opcode is used to detect
    1205
    ** whether or not there is a database client in another process with a wal-mode
    1206
    ** transaction open on the database or not. It is only available on unix.The
    1207
    ** (void*) argument passed with this file-control should be a pointer to a
    1208
    ** value of type (int). The integer value is set to 1 if the database is a wal
    1209
    ** mode database and there exists at least one client in another process that
    1210
    ** currently has an SQL transaction open on the database. It is set to 0 if
    1211
    ** the database is not a wal-mode db, or if there is no such connection in any
    1212
    ** other process. This opcode cannot be used to detect transactions opened
    1213
    ** by clients within the current process, only within other processes.
    1214
    **
    1215
    ** <li>[[SQLITE_FCNTL_CKSM_FILE]]
    1216
    ** The [SQLITE_FCNTL_CKSM_FILE] opcode is for use internally by the
    1217
    ** [checksum VFS shim] only.
    1218
    **
    1219
    ** <li>[[SQLITE_FCNTL_RESET_CACHE]]
    1220
    ** If there is currently no transaction open on the database, and the
    1221
    ** database is not a temp db, then the [SQLITE_FCNTL_RESET_CACHE] file-control
    1222
    ** purges the contents of the in-memory page cache. If there is an open
    1223
    ** transaction, or if the db is a temp-db, this opcode is a no-op, not an error.
    1224
    ** </ul>
    1225
    */
    1226
    #define SQLITE_FCNTL_LOCKSTATE               1
    1227
    #define SQLITE_FCNTL_GET_LOCKPROXYFILE       2
    1228
    #define SQLITE_FCNTL_SET_LOCKPROXYFILE       3
    1229
    #define SQLITE_FCNTL_LAST_ERRNO              4
    1230
    #define SQLITE_FCNTL_SIZE_HINT               5
    1231
    #define SQLITE_FCNTL_CHUNK_SIZE              6
    1232
    #define SQLITE_FCNTL_FILE_POINTER            7
    1233
    #define SQLITE_FCNTL_SYNC_OMITTED            8
    1234
    #define SQLITE_FCNTL_WIN32_AV_RETRY          9
    1235
    #define SQLITE_FCNTL_PERSIST_WAL            10
    1236
    #define SQLITE_FCNTL_OVERWRITE              11
    1237
    #define SQLITE_FCNTL_VFSNAME                12
    1238
    #define SQLITE_FCNTL_POWERSAFE_OVERWRITE    13
    1239
    #define SQLITE_FCNTL_PRAGMA                 14
    1240
    #define SQLITE_FCNTL_BUSYHANDLER            15
    1241
    #define SQLITE_FCNTL_TEMPFILENAME           16
    1242
    #define SQLITE_FCNTL_MMAP_SIZE              18
    1243
    #define SQLITE_FCNTL_TRACE                  19
    1244
    #define SQLITE_FCNTL_HAS_MOVED              20
    1245
    #define SQLITE_FCNTL_SYNC                   21
    1246
    #define SQLITE_FCNTL_COMMIT_PHASETWO        22
    1247
    #define SQLITE_FCNTL_WIN32_SET_HANDLE       23
    1248
    #define SQLITE_FCNTL_WAL_BLOCK              24
    1249
    #define SQLITE_FCNTL_ZIPVFS                 25
    1250
    #define SQLITE_FCNTL_RBU                    26
    1251
    #define SQLITE_FCNTL_VFS_POINTER            27
    1252
    #define SQLITE_FCNTL_JOURNAL_POINTER        28
    1253
    #define SQLITE_FCNTL_WIN32_GET_HANDLE       29
    1254
    #define SQLITE_FCNTL_PDB                    30
    1255
    #define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE     31
    1256
    #define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE    32
    1257
    #define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE  33
    1258
    #define SQLITE_FCNTL_LOCK_TIMEOUT           34
    1259
    #define SQLITE_FCNTL_DATA_VERSION           35
    1260
    #define SQLITE_FCNTL_SIZE_LIMIT             36
    1261
    #define SQLITE_FCNTL_CKPT_DONE              37
    1262
    #define SQLITE_FCNTL_RESERVE_BYTES          38
    1263
    #define SQLITE_FCNTL_CKPT_START             39
    1264
    #define SQLITE_FCNTL_EXTERNAL_READER        40
    1265
    #define SQLITE_FCNTL_CKSM_FILE              41
    1266
    #define SQLITE_FCNTL_RESET_CACHE            42
    1267
    #define SQLITE_FCNTL_NULL_IO                43
    1268
    #define SQLITE_FCNTL_BLOCK_ON_CONNECT       44
    1269
    1270
    /* deprecated names */
    1271
    #define SQLITE_GET_LOCKPROXYFILE      SQLITE_FCNTL_GET_LOCKPROXYFILE
    1272
    #define SQLITE_SET_LOCKPROXYFILE      SQLITE_FCNTL_SET_LOCKPROXYFILE
    1273
    #define SQLITE_LAST_ERRNO             SQLITE_FCNTL_LAST_ERRNO
    1274
    1275
    1276
    /*
    1277
    ** CAPI3REF: Mutex Handle
    1278
    **
    1279
    ** The mutex module within SQLite defines [sqlite3_mutex] to be an
    1280
    ** abstract type for a mutex object.  The SQLite core never looks
    1281
    ** at the internal representation of an [sqlite3_mutex].  It only
    1282
    ** deals with pointers to the [sqlite3_mutex] object.
    1283
    **
    1284
    ** Mutexes are created using [sqlite3_mutex_alloc()].
    1285
    */
    1286
    typedef struct sqlite3_mutex sqlite3_mutex;
    1287
    1288
    /*
    1289
    ** CAPI3REF: Loadable Extension Thunk
    1290
    **
    1291
    ** A pointer to the opaque sqlite3_api_routines structure is passed as
    1292
    ** the third parameter to entry points of [loadable extensions].  This
    1293
    ** structure must be typedefed in order to work around compiler warnings
    1294
    ** on some platforms.
    1295
    */
    1296
    typedef struct sqlite3_api_routines sqlite3_api_routines;
    1297
    1298
    /*
    1299
    ** CAPI3REF: File Name
    1300
    **
    1301
    ** Type [sqlite3_filename] is used by SQLite to pass filenames to the
    1302
    ** xOpen method of a [VFS]. It may be cast to (const char*) and treated
    1303
    ** as a normal, nul-terminated, UTF-8 buffer containing the filename, but
    1304
    ** may also be passed to special APIs such as:
    1305
    **
    1306
    ** <ul>
    1307
    ** <li>  sqlite3_filename_database()
    1308
    ** <li>  sqlite3_filename_journal()
    1309
    ** <li>  sqlite3_filename_wal()
    1310
    ** <li>  sqlite3_uri_parameter()
    1311
    ** <li>  sqlite3_uri_boolean()
    1312
    ** <li>  sqlite3_uri_int64()
    1313
    ** <li>  sqlite3_uri_key()
    1314
    ** </ul>
    1315
    */
    1316
    typedef const char *sqlite3_filename;
    1317
    1318
    /*
    1319
    ** CAPI3REF: OS Interface Object
    1320
    **
    1321
    ** An instance of the sqlite3_vfs object defines the interface between
    1322
    ** the SQLite core and the underlying operating system.  The "vfs"
    1323
    ** in the name of the object stands for "virtual file system".  See
    1324
    ** the [VFS | VFS documentation] for further information.
    1325
    **
    1326
    ** The VFS interface is sometimes extended by adding new methods onto
    1327
    ** the end.  Each time such an extension occurs, the iVersion field
    1328
    ** is incremented.  The iVersion value started out as 1 in
    1329
    ** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2
    1330
    ** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased
    1331
    ** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6].  Additional fields
    1332
    ** may be appended to the sqlite3_vfs object and the iVersion value
    1333
    ** may increase again in future versions of SQLite.
    1334
    ** Note that due to an oversight, the structure
    1335
    ** of the sqlite3_vfs object changed in the transition from
    1336
    ** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0]
    1337
    ** and yet the iVersion field was not increased.
    1338
    **
    1339
    ** The szOsFile field is the size of the subclassed [sqlite3_file]
    1340
    ** structure used by this VFS.  mxPathname is the maximum length of
    1341
    ** a pathname in this VFS.
    1342
    **
    1343
    ** Registered sqlite3_vfs objects are kept on a linked list formed by
    1344
    ** the pNext pointer.  The [sqlite3_vfs_register()]
    1345
    ** and [sqlite3_vfs_unregister()] interfaces manage this list
    1346
    ** in a thread-safe way.  The [sqlite3_vfs_find()] interface
    1347
    ** searches the list.  Neither the application code nor the VFS
    1348
    ** implementation should use the pNext pointer.
    1349
    **
    1350
    ** The pNext field is the only field in the sqlite3_vfs
    1351
    ** structure that SQLite will ever modify.  SQLite will only access
    1352
    ** or modify this field while holding a particular static mutex.
    1353
    ** The application should never modify anything within the sqlite3_vfs
    1354
    ** object once the object has been registered.
    1355
    **
    1356
    ** The zName field holds the name of the VFS module.  The name must
    1357
    ** be unique across all VFS modules.
    1358
    **
    1359
    ** [[sqlite3_vfs.xOpen]]
    1360
    ** ^SQLite guarantees that the zFilename parameter to xOpen
    1361
    ** is either a NULL pointer or string obtained
    1362
    ** from xFullPathname() with an optional suffix added.
    1363
    ** ^If a suffix is added to the zFilename parameter, it will
    1364
    ** consist of a single "-" character followed by no more than
    1365
    ** 11 alphanumeric and/or "-" characters.
    1366
    ** ^SQLite further guarantees that
    1367
    ** the string will be valid and unchanged until xClose() is
    1368
    ** called. Because of the previous sentence,
    1369
    ** the [sqlite3_file] can safely store a pointer to the
    1370
    ** filename if it needs to remember the filename for some reason.
    1371
    ** If the zFilename parameter to xOpen is a NULL pointer then xOpen
    1372
    ** must invent its own temporary name for the file.  ^Whenever the
    1373
    ** xFilename parameter is NULL it will also be the case that the
    1374
    ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
    1375
    **
    1376
    ** The flags argument to xOpen() includes all bits set in
    1377
    ** the flags argument to [sqlite3_open_v2()].  Or if [sqlite3_open()]
    1378
    ** or [sqlite3_open16()] is used, then flags includes at least
    1379
    ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE].
    1380
    ** If xOpen() opens a file read-only then it sets *pOutFlags to
    1381
    ** include [SQLITE_OPEN_READONLY].  Other bits in *pOutFlags may be set.
    1382
    **
    1383
    ** ^(SQLite will also add one of the following flags to the xOpen()
    1384
    ** call, depending on the object being opened:
    1385
    **
    1386
    ** <ul>
    1387
    ** <li>  [SQLITE_OPEN_MAIN_DB]
    1388
    ** <li>  [SQLITE_OPEN_MAIN_JOURNAL]
    1389
    ** <li>  [SQLITE_OPEN_TEMP_DB]
    1390
    ** <li>  [SQLITE_OPEN_TEMP_JOURNAL]
    1391
    ** <li>  [SQLITE_OPEN_TRANSIENT_DB]
    1392
    ** <li>  [SQLITE_OPEN_SUBJOURNAL]
    1393
    ** <li>  [SQLITE_OPEN_SUPER_JOURNAL]
    1394
    ** <li>  [SQLITE_OPEN_WAL]
    1395
    ** </ul>)^
    1396
    **
    1397
    ** The file I/O implementation can use the object type flags to
    1398
    ** change the way it deals with files.  For example, an application
    1399
    ** that does not care about crash recovery or rollback might make
    1400
    ** the open of a journal file a no-op.  Writes to this journal would
    1401
    ** also be no-ops, and any attempt to read the journal would return
    1402
    ** SQLITE_IOERR.  Or the implementation might recognize that a database
    1403
    ** file will be doing page-aligned sector reads and writes in a random
    1404
    ** order and set up its I/O subsystem accordingly.
    1405
    **
    1406
    ** SQLite might also add one of the following flags to the xOpen method:
    1407
    **
    1408
    ** <ul>
    1409
    ** <li> [SQLITE_OPEN_DELETEONCLOSE]
    1410
    ** <li> [SQLITE_OPEN_EXCLUSIVE]
    1411
    ** </ul>
    1412
    **
    1413
    ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
    1414
    ** deleted when it is closed.  ^The [SQLITE_OPEN_DELETEONCLOSE]
    1415
    ** will be set for TEMP databases and their journals, transient
    1416
    ** databases, and subjournals.
    1417
    **
    1418
    ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction
    1419
    ** with the [SQLITE_OPEN_CREATE] flag, which are both directly
    1420
    ** analogous to the O_EXCL and O_CREAT flags of the POSIX open()
    1421
    ** API.  The SQLITE_OPEN_EXCLUSIVE flag, when paired with the
    1422
    ** SQLITE_OPEN_CREATE, is used to indicate that file should always
    1423
    ** be created, and that it is an error if it already exists.
    1424
    ** It is <i>not</i> used to indicate the file should be opened
    1425
    ** for exclusive access.
    1426
    **
    1427
    ** ^At least szOsFile bytes of memory are allocated by SQLite
    1428
    ** to hold the [sqlite3_file] structure passed as the third
    1429
    ** argument to xOpen.  The xOpen method does not have to
    1430
    ** allocate the structure; it should just fill it in.  Note that
    1431
    ** the xOpen method must set the sqlite3_file.pMethods to either
    1432
    ** a valid [sqlite3_io_methods] object or to NULL.  xOpen must do
    1433
    ** this even if the open fails.  SQLite expects that the sqlite3_file.pMethods
    1434
    ** element will be valid after xOpen returns regardless of the success
    1435
    ** or failure of the xOpen call.
    1436
    **
    1437
    ** [[sqlite3_vfs.xAccess]]
    1438
    ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
    1439
    ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
    1440
    ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
    1441
    ** to test whether a file is at least readable.  The SQLITE_ACCESS_READ
    1442
    ** flag is never actually used and is not implemented in the built-in
    1443
    ** VFSes of SQLite.  The file is named by the second argument and can be a
    1444
    ** directory. The xAccess method returns [SQLITE_OK] on success or some
    1445
    ** non-zero error code if there is an I/O error or if the name of
    1446
    ** the file given in the second argument is illegal.  If SQLITE_OK
    1447
    ** is returned, then non-zero or zero is written into *pResOut to indicate
    1448
    ** whether or not the file is accessible.
    1449
    **
    1450
    ** ^SQLite will always allocate at least mxPathname+1 bytes for the
    1451
    ** output buffer xFullPathname.  The exact size of the output buffer
    1452
    ** is also passed as a parameter to both  methods. If the output buffer
    1453
    ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
    1454
    ** handled as a fatal error by SQLite, vfs implementations should endeavor
    1455
    ** to prevent this by setting mxPathname to a sufficiently large value.
    1456
    **
    1457
    ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64()
    1458
    ** interfaces are not strictly a part of the filesystem, but they are
    1459
    ** included in the VFS structure for completeness.
    1460
    ** The xRandomness() function attempts to return nBytes bytes
    1461
    ** of good-quality randomness into zOut.  The return value is
    1462
    ** the actual number of bytes of randomness obtained.
    1463
    ** The xSleep() method causes the calling thread to sleep for at
    1464
    ** least the number of microseconds given.  ^The xCurrentTime()
    1465
    ** method returns a Julian Day Number for the current date and time as
    1466
    ** a floating point value.
    1467
    ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian
    1468
    ** Day Number multiplied by 86400000 (the number of milliseconds in
    1469
    ** a 24-hour day).
    1470
    ** ^SQLite will use the xCurrentTimeInt64() method to get the current
    1471
    ** date and time if that method is available (if iVersion is 2 or
    1472
    ** greater and the function pointer is not NULL) and will fall back
    1473
    ** to xCurrentTime() if xCurrentTimeInt64() is unavailable.
    1474
    **
    1475
    ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces
    1476
    ** are not used by the SQLite core.  These optional interfaces are provided
    1477
    ** by some VFSes to facilitate testing of the VFS code. By overriding
    1478
    ** system calls with functions under its control, a test program can
    1479
    ** simulate faults and error conditions that would otherwise be difficult
    1480
    ** or impossible to induce.  The set of system calls that can be overridden
    1481
    ** varies from one VFS to another, and from one version of the same VFS to the
    1482
    ** next.  Applications that use these interfaces must be prepared for any
    1483
    ** or all of these interfaces to be NULL or for their behavior to change
    1484
    ** from one release to the next.  Applications must not attempt to access
    1485
    ** any of these methods if the iVersion of the VFS is less than 3.
    1486
    */
    1487
    typedef struct sqlite3_vfs sqlite3_vfs;
    1488
    typedef void (*sqlite3_syscall_ptr)(void);
    1489
    struct sqlite3_vfs {
    1490
      int iVersion;            /* Structure version number (currently 3) */
    1491
      int szOsFile;            /* Size of subclassed sqlite3_file */
    1492
      int mxPathname;          /* Maximum file pathname length */
    1493
      sqlite3_vfs *pNext;      /* Next registered VFS */
    1494
      const char *zName;       /* Name of this virtual file system */
    1495
      void *pAppData;          /* Pointer to application-specific data */
    1496
      int (*xOpen)(sqlite3_vfs*, sqlite3_filename zName, sqlite3_file*,
    1497
                   int flags, int *pOutFlags);
    1498
      int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);
    1499
      int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);
    1500
      int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);
    1501
      void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);
    1502
      void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
    1503
      void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);
    1504
      void (*xDlClose)(sqlite3_vfs*, void*);
    1505
      int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
    1506
      int (*xSleep)(sqlite3_vfs*, int microseconds);
    1507
      int (*xCurrentTime)(sqlite3_vfs*, double*);
    1508
      int (*xGetLastError)(sqlite3_vfs*, int, char *);
    1509
      /*
    1510
      ** The methods above are in version 1 of the sqlite_vfs object
    1511
      ** definition.  Those that follow are added in version 2 or later
    1512
      */
    1513
      int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);
    1514
      /*
    1515
      ** The methods above are in versions 1 and 2 of the sqlite_vfs object.
    1516
      ** Those below are for version 3 and greater.
    1517
      */
    1518
      int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr);
    1519
      sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName);
    1520
      const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName);
    1521
      /*
    1522
      ** The methods above are in versions 1 through 3 of the sqlite_vfs object.
    1523
      ** New fields may be appended in future versions.  The iVersion
    1524
      ** value will increment whenever this happens.
    1525
      */
    1526
    };
    1527
    1528
    /*
    1529
    ** CAPI3REF: Flags for the xAccess VFS method
    1530
    **
    1531
    ** These integer constants can be used as the third parameter to
    1532
    ** the xAccess method of an [sqlite3_vfs] object.  They determine
    1533
    ** what kind of permissions the xAccess method is looking for.
    1534
    ** With SQLITE_ACCESS_EXISTS, the xAccess method
    1535
    ** simply checks whether the file exists.
    1536
    ** With SQLITE_ACCESS_READWRITE, the xAccess method
    1537
    ** checks whether the named directory is both readable and writable
    1538
    ** (in other words, if files can be added, removed, and renamed within
    1539
    ** the directory).
    1540
    ** The SQLITE_ACCESS_READWRITE constant is currently used only by the
    1541
    ** [temp_store_directory pragma], though this could change in a future
    1542
    ** release of SQLite.
    1543
    ** With SQLITE_ACCESS_READ, the xAccess method
    1544
    ** checks whether the file is readable.  The SQLITE_ACCESS_READ constant is
    1545
    ** currently unused, though it might be used in a future release of
    1546
    ** SQLite.
    1547
    */
    1548
    #define SQLITE_ACCESS_EXISTS    0
    1549
    #define SQLITE_ACCESS_READWRITE 1   /* Used by PRAGMA temp_store_directory */
    1550
    #define SQLITE_ACCESS_READ      2   /* Unused */
    1551
    1552
    /*
    1553
    ** CAPI3REF: Flags for the xShmLock VFS method
    1554
    **
    1555
    ** These integer constants define the various locking operations
    1556
    ** allowed by the xShmLock method of [sqlite3_io_methods].  The
    1557
    ** following are the only legal combinations of flags to the
    1558
    ** xShmLock method:
    1559
    **
    1560
    ** <ul>
    1561
    ** <li>  SQLITE_SHM_LOCK | SQLITE_SHM_SHARED
    1562
    ** <li>  SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE
    1563
    ** <li>  SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED
    1564
    ** <li>  SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE
    1565
    ** </ul>
    1566
    **
    1567
    ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
    1568
    ** was given on the corresponding lock.
    1569
    **
    1570
    ** The xShmLock method can transition between unlocked and SHARED or
    1571
    ** between unlocked and EXCLUSIVE.  It cannot transition between SHARED
    1572
    ** and EXCLUSIVE.
    1573
    */
    1574
    #define SQLITE_SHM_UNLOCK       1
    1575
    #define SQLITE_SHM_LOCK         2
    1576
    #define SQLITE_SHM_SHARED       4
    1577
    #define SQLITE_SHM_EXCLUSIVE    8
    1578
    1579
    /*
    1580
    ** CAPI3REF: Maximum xShmLock index
    1581
    **
    1582
    ** The xShmLock method on [sqlite3_io_methods] may use values
    1583
    ** between 0 and this upper bound as its "offset" argument.
    1584
    ** The SQLite core will never attempt to acquire or release a
    1585
    ** lock outside of this range
    1586
    */
    1587
    #define SQLITE_SHM_NLOCK        8
    1588
    1589
    1590
    /*
    1591
    ** CAPI3REF: Initialize The SQLite Library
    1592
    **
    1593
    ** ^The sqlite3_initialize() routine initializes the
    1594
    ** SQLite library.  ^The sqlite3_shutdown() routine
    1595
    ** deallocates any resources that were allocated by sqlite3_initialize().
    1596
    ** These routines are designed to aid in process initialization and
    1597
    ** shutdown on embedded systems.  Workstation applications using
    1598
    ** SQLite normally do not need to invoke either of these routines.
    1599
    **
    1600
    ** A call to sqlite3_initialize() is an "effective" call if it is
    1601
    ** the first time sqlite3_initialize() is invoked during the lifetime of
    1602
    ** the process, or if it is the first time sqlite3_initialize() is invoked
    1603
    ** following a call to sqlite3_shutdown().  ^(Only an effective call
    1604
    ** of sqlite3_initialize() does any initialization.  All other calls
    1605
    ** are harmless no-ops.)^
    1606
    **
    1607
    ** A call to sqlite3_shutdown() is an "effective" call if it is the first
    1608
    ** call to sqlite3_shutdown() since the last sqlite3_initialize().  ^(Only
    1609
    ** an effective call to sqlite3_shutdown() does any deinitialization.
    1610
    ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
    1611
    **
    1612
    ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
    1613
    ** is not.  The sqlite3_shutdown() interface must only be called from a
    1614
    ** single thread.  All open [database connections] must be closed and all
    1615
    ** other SQLite resources must be deallocated prior to invoking
    1616
    ** sqlite3_shutdown().
    1617
    **
    1618
    ** Among other things, ^sqlite3_initialize() will invoke
    1619
    ** sqlite3_os_init().  Similarly, ^sqlite3_shutdown()
    1620
    ** will invoke sqlite3_os_end().
    1621
    **
    1622
    ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
    1623
    ** ^If for some reason, sqlite3_initialize() is unable to initialize
    1624
    ** the library (perhaps it is unable to allocate a needed resource such
    1625
    ** as a mutex) it returns an [error code] other than [SQLITE_OK].
    1626
    **
    1627
    ** ^The sqlite3_initialize() routine is called internally by many other
    1628
    ** SQLite interfaces so that an application usually does not need to
    1629
    ** invoke sqlite3_initialize() directly.  For example, [sqlite3_open()]
    1630
    ** calls sqlite3_initialize() so the SQLite library will be automatically
    1631
    ** initialized when [sqlite3_open()] is called if it has not be initialized
    1632
    ** already.  ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
    1633
    ** compile-time option, then the automatic calls to sqlite3_initialize()
    1634
    ** are omitted and the application must call sqlite3_initialize() directly
    1635
    ** prior to using any other SQLite interface.  For maximum portability,
    1636
    ** it is recommended that applications always invoke sqlite3_initialize()
    1637
    ** directly prior to using any other SQLite interface.  Future releases
    1638
    ** of SQLite may require this.  In other words, the behavior exhibited
    1639
    ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
    1640
    ** default behavior in some future release of SQLite.
    1641
    **
    1642
    ** The sqlite3_os_init() routine does operating-system specific
    1643
    ** initialization of the SQLite library.  The sqlite3_os_end()
    1644
    ** routine undoes the effect of sqlite3_os_init().  Typical tasks
    1645
    ** performed by these routines include allocation or deallocation
    1646
    ** of static resources, initialization of global variables,
    1647
    ** setting up a default [sqlite3_vfs] module, or setting up
    1648
    ** a default configuration using [sqlite3_config()].
    1649
    **
    1650
    ** The application should never invoke either sqlite3_os_init()
    1651
    ** or sqlite3_os_end() directly.  The application should only invoke
    1652
    ** sqlite3_initialize() and sqlite3_shutdown().  The sqlite3_os_init()
    1653
    ** interface is called automatically by sqlite3_initialize() and
    1654
    ** sqlite3_os_end() is called by sqlite3_shutdown().  Appropriate
    1655
    ** implementations for sqlite3_os_init() and sqlite3_os_end()
    1656
    ** are built into SQLite when it is compiled for Unix, Windows, or OS/2.
    1657
    ** When [custom builds | built for other platforms]
    1658
    ** (using the [SQLITE_OS_OTHER=1] compile-time
    1659
    ** option) the application must supply a suitable implementation for
    1660
    ** sqlite3_os_init() and sqlite3_os_end().  An application-supplied
    1661
    ** implementation of sqlite3_os_init() or sqlite3_os_end()
    1662
    ** must return [SQLITE_OK] on success and some other [error code] upon
    1663
    ** failure.
    1664
    */
    1665
    SQLITE_API int sqlite3_initialize(void);
    1666
    SQLITE_API int sqlite3_shutdown(void);
    1667
    SQLITE_API int sqlite3_os_init(void);
    1668
    SQLITE_API int sqlite3_os_end(void);
    1669
    1670
    /*
    1671
    ** CAPI3REF: Configuring The SQLite Library
    1672
    **
    1673
    ** The sqlite3_config() interface is used to make global configuration
    1674
    ** changes to SQLite in order to tune SQLite to the specific needs of
    1675
    ** the application.  The default configuration is recommended for most
    1676
    ** applications and so this routine is usually not necessary.  It is
    1677
    ** provided to support rare applications with unusual needs.
    1678
    **
    1679
    ** <b>The sqlite3_config() interface is not threadsafe. The application
    1680
    ** must ensure that no other SQLite interfaces are invoked by other
    1681
    ** threads while sqlite3_config() is running.</b>
    1682
    **
    1683
    ** The first argument to sqlite3_config() is an integer
    1684
    ** [configuration option] that determines
    1685
    ** what property of SQLite is to be configured.  Subsequent arguments
    1686
    ** vary depending on the [configuration option]
    1687
    ** in the first argument.
    1688
    **
    1689
    ** For most configuration options, the sqlite3_config() interface
    1690
    ** may only be invoked prior to library initialization using
    1691
    ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
    1692
    ** The exceptional configuration options that may be invoked at any time
    1693
    ** are called "anytime configuration options".
    1694
    ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
    1695
    ** [sqlite3_shutdown()] with a first argument that is not an anytime
    1696
    ** configuration option, then the sqlite3_config() call will return SQLITE_MISUSE.
    1697
    ** Note, however, that ^sqlite3_config() can be called as part of the
    1698
    ** implementation of an application-defined [sqlite3_os_init()].
    1699
    **
    1700
    ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
    1701
    ** ^If the option is unknown or SQLite is unable to set the option
    1702
    ** then this routine returns a non-zero [error code].
    1703
    */
    1704
    SQLITE_API int sqlite3_config(int, ...);
    1705
    1706
    /*
    1707
    ** CAPI3REF: Configure database connections
    1708
    ** METHOD: sqlite3
    1709
    **
    1710
    ** The sqlite3_db_config() interface is used to make configuration
    1711
    ** changes to a [database connection].  The interface is similar to
    1712
    ** [sqlite3_config()] except that the changes apply to a single
    1713
    ** [database connection] (specified in the first argument).
    1714
    **
    1715
    ** The second argument to sqlite3_db_config(D,V,...)  is the
    1716
    ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code
    1717
    ** that indicates what aspect of the [database connection] is being configured.
    1718
    ** Subsequent arguments vary depending on the configuration verb.
    1719
    **
    1720
    ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
    1721
    ** the call is considered successful.
    1722
    */
    1723
    SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...);
    1724
    1725
    /*
    1726
    ** CAPI3REF: Memory Allocation Routines
    1727
    **
    1728
    ** An instance of this object defines the interface between SQLite
    1729
    ** and low-level memory allocation routines.
    1730
    **
    1731
    ** This object is used in only one place in the SQLite interface.
    1732
    ** A pointer to an instance of this object is the argument to
    1733
    ** [sqlite3_config()] when the configuration option is
    1734
    ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC].
    1735
    ** By creating an instance of this object
    1736
    ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])
    1737
    ** during configuration, an application can specify an alternative
    1738
    ** memory allocation subsystem for SQLite to use for all of its
    1739
    ** dynamic memory needs.
    1740
    **
    1741
    ** Note that SQLite comes with several [built-in memory allocators]
    1742
    ** that are perfectly adequate for the overwhelming majority of applications
    1743
    ** and that this object is only useful to a tiny minority of applications
    1744
    ** with specialized memory allocation requirements.  This object is
    1745
    ** also used during testing of SQLite in order to specify an alternative
    1746
    ** memory allocator that simulates memory out-of-memory conditions in
    1747
    ** order to verify that SQLite recovers gracefully from such
    1748
    ** conditions.
    1749
    **
    1750
    ** The xMalloc, xRealloc, and xFree methods must work like the
    1751
    ** malloc(), realloc() and free() functions from the standard C library.
    1752
    ** ^SQLite guarantees that the second argument to
    1753
    ** xRealloc is always a value returned by a prior call to xRoundup.
    1754
    **
    1755
    ** xSize should return the allocated size of a memory allocation
    1756
    ** previously obtained from xMalloc or xRealloc.  The allocated size
    1757
    ** is always at least as big as the requested size but may be larger.
    1758
    **
    1759
    ** The xRoundup method returns what would be the allocated size of
    1760
    ** a memory allocation given a particular requested size.  Most memory
    1761
    ** allocators round up memory allocations at least to the next multiple
    1762
    ** of 8.  Some allocators round up to a larger multiple or to a power of 2.
    1763
    ** Every memory allocation request coming in through [sqlite3_malloc()]
    1764
    ** or [sqlite3_realloc()] first calls xRoundup.  If xRoundup returns 0,
    1765
    ** that causes the corresponding memory allocation to fail.
    1766
    **
    1767
    ** The xInit method initializes the memory allocator.  For example,
    1768
    ** it might allocate any required mutexes or initialize internal data
    1769
    ** structures.  The xShutdown method is invoked (indirectly) by
    1770
    ** [sqlite3_shutdown()] and should deallocate any resources acquired
    1771
    ** by xInit.  The pAppData pointer is used as the only parameter to
    1772
    ** xInit and xShutdown.
    1773
    **
    1774
    ** SQLite holds the [SQLITE_MUTEX_STATIC_MAIN] mutex when it invokes
    1775
    ** the xInit method, so the xInit method need not be threadsafe.  The
    1776
    ** xShutdown method is only called from [sqlite3_shutdown()] so it does
    1777
    ** not need to be threadsafe either.  For all other methods, SQLite
    1778
    ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
    1779
    ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
    1780
    ** it is by default) and so the methods are automatically serialized.
    1781
    ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other
    1782
    ** methods must be threadsafe or else make their own arrangements for
    1783
    ** serialization.
    1784
    **
    1785
    ** SQLite will never invoke xInit() more than once without an intervening
    1786
    ** call to xShutdown().
    1787
    */
    1788
    typedef struct sqlite3_mem_methods sqlite3_mem_methods;
    1789
    struct sqlite3_mem_methods {
    1790
      void *(*xMalloc)(int);         /* Memory allocation function */
    1791
      void (*xFree)(void*);          /* Free a prior allocation */
    1792
      void *(*xRealloc)(void*,int);  /* Resize an allocation */
    1793
      int (*xSize)(void*);           /* Return the size of an allocation */
    1794
      int (*xRoundup)(int);          /* Round up request size to allocation size */
    1795
      int (*xInit)(void*);           /* Initialize the memory allocator */
    1796
      void (*xShutdown)(void*);      /* Deinitialize the memory allocator */
    1797
      void *pAppData;                /* Argument to xInit() and xShutdown() */
    1798
    };
    1799
    1800
    /*
    1801
    ** CAPI3REF: Configuration Options
    1802
    ** KEYWORDS: {configuration option}
    1803
    **
    1804
    ** These constants are the available integer configuration options that
    1805
    ** can be passed as the first argument to the [sqlite3_config()] interface.
    1806
    **
    1807
    ** Most of the configuration options for sqlite3_config()
    1808
    ** will only work if invoked prior to [sqlite3_initialize()] or after
    1809
    ** [sqlite3_shutdown()].  The few exceptions to this rule are called
    1810
    ** "anytime configuration options".
    1811
    ** ^Calling [sqlite3_config()] with a first argument that is not an
    1812
    ** anytime configuration option in between calls to [sqlite3_initialize()] and
    1813
    ** [sqlite3_shutdown()] is a no-op that returns SQLITE_MISUSE.
    1814
    **
    1815
    ** The set of anytime configuration options can change (by insertions
    1816
    ** and/or deletions) from one release of SQLite to the next.
    1817
    ** As of SQLite version 3.42.0, the complete set of anytime configuration
    1818
    ** options is:
    1819
    ** <ul>
    1820
    ** <li> SQLITE_CONFIG_LOG
    1821
    ** <li> SQLITE_CONFIG_PCACHE_HDRSZ
    1822
    ** </ul>
    1823
    **
    1824
    ** New configuration options may be added in future releases of SQLite.
    1825
    ** Existing configuration options might be discontinued.  Applications
    1826
    ** should check the return code from [sqlite3_config()] to make sure that
    1827
    ** the call worked.  The [sqlite3_config()] interface will return a
    1828
    ** non-zero [error code] if a discontinued or unsupported configuration option
    1829
    ** is invoked.
    1830
    **
    1831
    ** <dl>
    1832
    ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
    1833
    ** <dd>There are no arguments to this option.  ^This option sets the
    1834
    ** [threading mode] to Single-thread.  In other words, it disables
    1835
    ** all mutexing and puts SQLite into a mode where it can only be used
    1836
    ** by a single thread.   ^If SQLite is compiled with
    1837
    ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
    1838
    ** it is not possible to change the [threading mode] from its default
    1839
    ** value of Single-thread and so [sqlite3_config()] will return
    1840
    ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD
    1841
    ** configuration option.</dd>
    1842
    **
    1843
    ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt>
    1844
    ** <dd>There are no arguments to this option.  ^This option sets the
    1845
    ** [threading mode] to Multi-thread.  In other words, it disables
    1846
    ** mutexing on [database connection] and [prepared statement] objects.
    1847
    ** The application is responsible for serializing access to
    1848
    ** [database connections] and [prepared statements].  But other mutexes
    1849
    ** are enabled so that SQLite will be safe to use in a multi-threaded
    1850
    ** environment as long as no two threads attempt to use the same
    1851
    ** [database connection] at the same time.  ^If SQLite is compiled with
    1852
    ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
    1853
    ** it is not possible to set the Multi-thread [threading mode] and
    1854
    ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
    1855
    ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
    1856
    **
    1857
    ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt>
    1858
    ** <dd>There are no arguments to this option.  ^This option sets the
    1859
    ** [threading mode] to Serialized. In other words, this option enables
    1860
    ** all mutexes including the recursive
    1861
    ** mutexes on [database connection] and [prepared statement] objects.
    1862
    ** In this mode (which is the default when SQLite is compiled with
    1863
    ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
    1864
    ** to [database connections] and [prepared statements] so that the
    1865
    ** application is free to use the same [database connection] or the
    1866
    ** same [prepared statement] in different threads at the same time.
    1867
    ** ^If SQLite is compiled with
    1868
    ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
    1869
    ** it is not possible to set the Serialized [threading mode] and
    1870
    ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
    1871
    ** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
    1872
    **
    1873
    ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>
    1874
    ** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is
    1875
    ** a pointer to an instance of the [sqlite3_mem_methods] structure.
    1876
    ** The argument specifies
    1877
    ** alternative low-level memory allocation routines to be used in place of
    1878
    ** the memory allocation routines built into SQLite.)^ ^SQLite makes
    1879
    ** its own private copy of the content of the [sqlite3_mem_methods] structure
    1880
    ** before the [sqlite3_config()] call returns.</dd>
    1881
    **
    1882
    ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>
    1883
    ** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which
    1884
    ** is a pointer to an instance of the [sqlite3_mem_methods] structure.
    1885
    ** The [sqlite3_mem_methods]
    1886
    ** structure is filled with the currently defined memory allocation routines.)^
    1887
    ** This option can be used to overload the default memory allocation
    1888
    ** routines with a wrapper that simulations memory allocation failure or
    1889
    ** tracks memory usage, for example. </dd>
    1890
    **
    1891
    ** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt>
    1892
    ** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of
    1893
    ** type int, interpreted as a boolean, which if true provides a hint to
    1894
    ** SQLite that it should avoid large memory allocations if possible.
    1895
    ** SQLite will run faster if it is free to make large memory allocations,
    1896
    ** but some application might prefer to run slower in exchange for
    1897
    ** guarantees about memory fragmentation that are possible if large
    1898
    ** allocations are avoided.  This hint is normally off.
    1899
    ** </dd>
    1900
    **
    1901
    ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
    1902
    ** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int,
    1903
    ** interpreted as a boolean, which enables or disables the collection of
    1904
    ** memory allocation statistics. ^(When memory allocation statistics are
    1905
    ** disabled, the following SQLite interfaces become non-operational:
    1906
    **   <ul>
    1907
    **   <li> [sqlite3_hard_heap_limit64()]
    1908
    **   <li> [sqlite3_memory_used()]
    1909
    **   <li> [sqlite3_memory_highwater()]
    1910
    **   <li> [sqlite3_soft_heap_limit64()]
    1911
    **   <li> [sqlite3_status64()]
    1912
    **   </ul>)^
    1913
    ** ^Memory allocation statistics are enabled by default unless SQLite is
    1914
    ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
    1915
    ** allocation statistics are disabled by default.
    1916
    ** </dd>
    1917
    **
    1918
    ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>
    1919
    ** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used.
    1920
    ** </dd>
    1921
    **
    1922
    ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
    1923
    ** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool
    1924
    ** that SQLite can use for the database page cache with the default page
    1925
    ** cache implementation.
    1926
    ** This configuration option is a no-op if an application-defined page
    1927
    ** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2].
    1928
    ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to
    1929
    ** 8-byte aligned memory (pMem), the size of each page cache line (sz),
    1930
    ** and the number of cache lines (N).
    1931
    ** The sz argument should be the size of the largest database page
    1932
    ** (a power of two between 512 and 65536) plus some extra bytes for each
    1933
    ** page header.  ^The number of extra bytes needed by the page header
    1934
    ** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ].
    1935
    ** ^It is harmless, apart from the wasted memory,
    1936
    ** for the sz parameter to be larger than necessary.  The pMem
    1937
    ** argument must be either a NULL pointer or a pointer to an 8-byte
    1938
    ** aligned block of memory of at least sz*N bytes, otherwise
    1939
    ** subsequent behavior is undefined.
    1940
    ** ^When pMem is not NULL, SQLite will strive to use the memory provided
    1941
    ** to satisfy page cache needs, falling back to [sqlite3_malloc()] if
    1942
    ** a page cache line is larger than sz bytes or if all of the pMem buffer
    1943
    ** is exhausted.
    1944
    ** ^If pMem is NULL and N is non-zero, then each database connection
    1945
    ** does an initial bulk allocation for page cache memory
    1946
    ** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or
    1947
    ** of -1024*N bytes if N is negative, . ^If additional
    1948
    ** page cache memory is needed beyond what is provided by the initial
    1949
    ** allocation, then SQLite goes to [sqlite3_malloc()] separately for each
    1950
    ** additional cache line. </dd>
    1951
    **
    1952
    ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
    1953
    ** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer
    1954
    ** that SQLite will use for all of its dynamic memory allocation needs
    1955
    ** beyond those provided for by [SQLITE_CONFIG_PAGECACHE].
    1956
    ** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled
    1957
    ** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns
    1958
    ** [SQLITE_ERROR] if invoked otherwise.
    1959
    ** ^There are three arguments to SQLITE_CONFIG_HEAP:
    1960
    ** An 8-byte aligned pointer to the memory,
    1961
    ** the number of bytes in the memory buffer, and the minimum allocation size.
    1962
    ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
    1963
    ** to using its default memory allocator (the system malloc() implementation),
    1964
    ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC].  ^If the
    1965
    ** memory pointer is not NULL then the alternative memory
    1966
    ** allocator is engaged to handle all of SQLites memory allocation needs.
    1967
    ** The first pointer (the memory pointer) must be aligned to an 8-byte
    1968
    ** boundary or subsequent behavior of SQLite will be undefined.
    1969
    ** The minimum allocation size is capped at 2**12. Reasonable values
    1970
    ** for the minimum allocation size are 2**5 through 2**8.</dd>
    1971
    **
    1972
    ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
    1973
    ** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a
    1974
    ** pointer to an instance of the [sqlite3_mutex_methods] structure.
    1975
    ** The argument specifies alternative low-level mutex routines to be used
    1976
    ** in place the mutex routines built into SQLite.)^  ^SQLite makes a copy of
    1977
    ** the content of the [sqlite3_mutex_methods] structure before the call to
    1978
    ** [sqlite3_config()] returns. ^If SQLite is compiled with
    1979
    ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
    1980
    ** the entire mutexing subsystem is omitted from the build and hence calls to
    1981
    ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
    1982
    ** return [SQLITE_ERROR].</dd>
    1983
    **
    1984
    ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>
    1985
    ** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which
    1986
    ** is a pointer to an instance of the [sqlite3_mutex_methods] structure.  The
    1987
    ** [sqlite3_mutex_methods]
    1988
    ** structure is filled with the currently defined mutex routines.)^
    1989
    ** This option can be used to overload the default mutex allocation
    1990
    ** routines with a wrapper used to track mutex usage for performance
    1991
    ** profiling or testing, for example.   ^If SQLite is compiled with
    1992
    ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
    1993
    ** the entire mutexing subsystem is omitted from the build and hence calls to
    1994
    ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
    1995
    ** return [SQLITE_ERROR].</dd>
    1996
    **
    1997
    ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>
    1998
    ** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine
    1999
    ** the default size of [lookaside memory] on each [database connection].
    2000
    ** The first argument is the
    2001
    ** size of each lookaside buffer slot ("sz") and the second is the number of
    2002
    ** slots allocated to each database connection ("cnt").)^
    2003
    ** ^(SQLITE_CONFIG_LOOKASIDE sets the <i>default</i> lookaside size.
    2004
    ** The [SQLITE_DBCONFIG_LOOKASIDE] option to [sqlite3_db_config()] can
    2005
    ** be used to change the lookaside configuration on individual connections.)^
    2006
    ** The [-DSQLITE_DEFAULT_LOOKASIDE] option can be used to change the
    2007
    ** default lookaside configuration at compile-time.
    2008
    ** </dd>
    2009
    **
    2010
    ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt>
    2011
    ** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is
    2012
    ** a pointer to an [sqlite3_pcache_methods2] object.  This object specifies
    2013
    ** the interface to a custom page cache implementation.)^
    2014
    ** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd>
    2015
    **
    2016
    ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt>
    2017
    ** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which
    2018
    ** is a pointer to an [sqlite3_pcache_methods2] object.  SQLite copies of
    2019
    ** the current page cache implementation into that object.)^ </dd>
    2020
    **
    2021
    ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
    2022
    ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite
    2023
    ** global [error log].
    2024
    ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
    2025
    ** function with a call signature of void(*)(void*,int,const char*),
    2026
    ** and a pointer to void. ^If the function pointer is not NULL, it is
    2027
    ** invoked by [sqlite3_log()] to process each logging event.  ^If the
    2028
    ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.
    2029
    ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is
    2030
    ** passed through as the first parameter to the application-defined logger
    2031
    ** function whenever that function is invoked.  ^The second parameter to
    2032
    ** the logger function is a copy of the first parameter to the corresponding
    2033
    ** [sqlite3_log()] call and is intended to be a [result code] or an
    2034
    ** [extended result code].  ^The third parameter passed to the logger is
    2035
    ** log message after formatting via [sqlite3_snprintf()].
    2036
    ** The SQLite logging interface is not reentrant; the logger function
    2037
    ** supplied by the application must not invoke any SQLite interface.
    2038
    ** In a multi-threaded application, the application-defined logger
    2039
    ** function must be threadsafe. </dd>
    2040
    **
    2041
    ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
    2042
    ** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int.
    2043
    ** If non-zero, then URI handling is globally enabled. If the parameter is zero,
    2044
    ** then URI handling is globally disabled.)^ ^If URI handling is globally
    2045
    ** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()],
    2046
    ** [sqlite3_open16()] or
    2047
    ** specified as part of [ATTACH] commands are interpreted as URIs, regardless
    2048
    ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
    2049
    ** connection is opened. ^If it is globally disabled, filenames are
    2050
    ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
    2051
    ** database connection is opened. ^(By default, URI handling is globally
    2052
    ** disabled. The default value may be changed by compiling with the
    2053
    ** [SQLITE_USE_URI] symbol defined.)^
    2054
    **
    2055
    ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN
    2056
    ** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer
    2057
    ** argument which is interpreted as a boolean in order to enable or disable
    2058
    ** the use of covering indices for full table scans in the query optimizer.
    2059
    ** ^The default setting is determined
    2060
    ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on"
    2061
    ** if that compile-time option is omitted.
    2062
    ** The ability to disable the use of covering indices for full table scans
    2063
    ** is because some incorrectly coded legacy applications might malfunction
    2064
    ** when the optimization is enabled.  Providing the ability to
    2065
    ** disable the optimization allows the older, buggy application code to work
    2066
    ** without change even with newer versions of SQLite.
    2067
    **
    2068
    ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]]
    2069
    ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE
    2070
    ** <dd> These options are obsolete and should not be used by new code.
    2071
    ** They are retained for backwards compatibility but are now no-ops.
    2072
    ** </dd>
    2073
    **
    2074
    ** [[SQLITE_CONFIG_SQLLOG]]
    2075
    ** <dt>SQLITE_CONFIG_SQLLOG
    2076
    ** <dd>This option is only available if sqlite is compiled with the
    2077
    ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should
    2078
    ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int).
    2079
    ** The second should be of type (void*). The callback is invoked by the library
    2080
    ** in three separate circumstances, identified by the value passed as the
    2081
    ** fourth parameter. If the fourth parameter is 0, then the database connection
    2082
    ** passed as the second argument has just been opened. The third argument
    2083
    ** points to a buffer containing the name of the main database file. If the
    2084
    ** fourth parameter is 1, then the SQL statement that the third parameter
    2085
    ** points to has just been executed. Or, if the fourth parameter is 2, then
    2086
    ** the connection being passed as the second parameter is being closed. The
    2087
    ** third parameter is passed NULL In this case.  An example of using this
    2088
    ** configuration option can be seen in the "test_sqllog.c" source file in
    2089
    ** the canonical SQLite source tree.</dd>
    2090
    **
    2091
    ** [[SQLITE_CONFIG_MMAP_SIZE]]
    2092
    ** <dt>SQLITE_CONFIG_MMAP_SIZE
    2093
    ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values
    2094
    ** that are the default mmap size limit (the default setting for
    2095
    ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit.
    2096
    ** ^The default setting can be overridden by each database connection using
    2097
    ** either the [PRAGMA mmap_size] command, or by using the
    2098
    ** [SQLITE_FCNTL_MMAP_SIZE] file control.  ^(The maximum allowed mmap size
    2099
    ** will be silently truncated if necessary so that it does not exceed the
    2100
    ** compile-time maximum mmap size set by the
    2101
    ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^
    2102
    ** ^If either argument to this option is negative, then that argument is
    2103
    ** changed to its compile-time default.
    2104
    **
    2105
    ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]]
    2106
    ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE
    2107
    ** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is
    2108
    ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro
    2109
    ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value
    2110
    ** that specifies the maximum size of the created heap.
    2111
    **
    2112
    ** [[SQLITE_CONFIG_PCACHE_HDRSZ]]
    2113
    ** <dt>SQLITE_CONFIG_PCACHE_HDRSZ
    2114
    ** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which
    2115
    ** is a pointer to an integer and writes into that integer the number of extra
    2116
    ** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE].
    2117
    ** The amount of extra space required can change depending on the compiler,
    2118
    ** target platform, and SQLite version.
    2119
    **
    2120
    ** [[SQLITE_CONFIG_PMASZ]]
    2121
    ** <dt>SQLITE_CONFIG_PMASZ
    2122
    ** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which
    2123
    ** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded
    2124
    ** sorter to that integer.  The default minimum PMA Size is set by the
    2125
    ** [SQLITE_SORTER_PMASZ] compile-time option.  New threads are launched
    2126
    ** to help with sort operations when multithreaded sorting
    2127
    ** is enabled (using the [PRAGMA threads] command) and the amount of content
    2128
    ** to be sorted exceeds the page size times the minimum of the
    2129
    ** [PRAGMA cache_size] setting and this value.
    2130
    **
    2131
    ** [[SQLITE_CONFIG_STMTJRNL_SPILL]]
    2132
    ** <dt>SQLITE_CONFIG_STMTJRNL_SPILL
    2133
    ** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which
    2134
    ** becomes the [statement journal] spill-to-disk threshold.
    2135
    ** [Statement journals] are held in memory until their size (in bytes)
    2136
    ** exceeds this threshold, at which point they are written to disk.
    2137
    ** Or if the threshold is -1, statement journals are always held
    2138
    ** exclusively in memory.
    2139
    ** Since many statement journals never become large, setting the spill
    2140
    ** threshold to a value such as 64KiB can greatly reduce the amount of
    2141
    ** I/O required to support statement rollback.
    2142
    ** The default value for this setting is controlled by the
    2143
    ** [SQLITE_STMTJRNL_SPILL] compile-time option.
    2144
    **
    2145
    ** [[SQLITE_CONFIG_SORTERREF_SIZE]]
    2146
    ** <dt>SQLITE_CONFIG_SORTERREF_SIZE
    2147
    ** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter
    2148
    ** of type (int) - the new value of the sorter-reference size threshold.
    2149
    ** Usually, when SQLite uses an external sort to order records according
    2150
    ** to an ORDER BY clause, all fields required by the caller are present in the
    2151
    ** sorted records. However, if SQLite determines based on the declared type
    2152
    ** of a table column that its values are likely to be very large - larger
    2153
    ** than the configured sorter-reference size threshold - then a reference
    2154
    ** is stored in each sorted record and the required column values loaded
    2155
    ** from the database as records are returned in sorted order. The default
    2156
    ** value for this option is to never use this optimization. Specifying a
    2157
    ** negative value for this option restores the default behavior.
    2158
    ** This option is only available if SQLite is compiled with the
    2159
    ** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option.
    2160
    **
    2161
    ** [[SQLITE_CONFIG_MEMDB_MAXSIZE]]
    2162
    ** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE
    2163
    ** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter
    2164
    ** [sqlite3_int64] parameter which is the default maximum size for an in-memory
    2165
    ** database created using [sqlite3_deserialize()].  This default maximum
    2166
    ** size can be adjusted up or down for individual databases using the
    2167
    ** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control].  If this
    2168
    ** configuration setting is never used, then the default maximum is determined
    2169
    ** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option.  If that
    2170
    ** compile-time option is not set, then the default maximum is 1073741824.
    2171
    **
    2172
    ** [[SQLITE_CONFIG_ROWID_IN_VIEW]]
    2173
    ** <dt>SQLITE_CONFIG_ROWID_IN_VIEW
    2174
    ** <dd>The SQLITE_CONFIG_ROWID_IN_VIEW option enables or disables the ability
    2175
    ** for VIEWs to have a ROWID.  The capability can only be enabled if SQLite is
    2176
    ** compiled with -DSQLITE_ALLOW_ROWID_IN_VIEW, in which case the capability
    2177
    ** defaults to on.  This configuration option queries the current setting or
    2178
    ** changes the setting to off or on.  The argument is a pointer to an integer.
    2179
    ** If that integer initially holds a value of 1, then the ability for VIEWs to
    2180
    ** have ROWIDs is activated.  If the integer initially holds zero, then the
    2181
    ** ability is deactivated.  Any other initial value for the integer leaves the
    2182
    ** setting unchanged.  After changes, if any, the integer is written with
    2183
    ** a 1 or 0, if the ability for VIEWs to have ROWIDs is on or off.  If SQLite
    2184
    ** is compiled without -DSQLITE_ALLOW_ROWID_IN_VIEW (which is the usual and
    2185
    ** recommended case) then the integer is always filled with zero, regardless
    2186
    ** if its initial value.
    2187
    ** </dl>
    2188
    */
    2189
    #define SQLITE_CONFIG_SINGLETHREAD         1  /* nil */
    2190
    #define SQLITE_CONFIG_MULTITHREAD          2  /* nil */
    2191
    #define SQLITE_CONFIG_SERIALIZED           3  /* nil */
    2192
    #define SQLITE_CONFIG_MALLOC               4  /* sqlite3_mem_methods* */
    2193
    #define SQLITE_CONFIG_GETMALLOC            5  /* sqlite3_mem_methods* */
    2194
    #define SQLITE_CONFIG_SCRATCH              6  /* No longer used */
    2195
    #define SQLITE_CONFIG_PAGECACHE            7  /* void*, int sz, int N */
    2196
    #define SQLITE_CONFIG_HEAP                 8  /* void*, int nByte, int min */
    2197
    #define SQLITE_CONFIG_MEMSTATUS            9  /* boolean */
    2198
    #define SQLITE_CONFIG_MUTEX               10  /* sqlite3_mutex_methods* */
    2199
    #define SQLITE_CONFIG_GETMUTEX            11  /* sqlite3_mutex_methods* */
    2200
    /* previously SQLITE_CONFIG_CHUNKALLOC    12 which is now unused. */
    2201
    #define SQLITE_CONFIG_LOOKASIDE           13  /* int int */
    2202
    #define SQLITE_CONFIG_PCACHE              14  /* no-op */
    2203
    #define SQLITE_CONFIG_GETPCACHE           15  /* no-op */
    2204
    #define SQLITE_CONFIG_LOG                 16  /* xFunc, void* */
    2205
    #define SQLITE_CONFIG_URI                 17  /* int */
    2206
    #define SQLITE_CONFIG_PCACHE2             18  /* sqlite3_pcache_methods2* */
    2207
    #define SQLITE_CONFIG_GETPCACHE2          19  /* sqlite3_pcache_methods2* */
    2208
    #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20  /* int */
    2209
    #define SQLITE_CONFIG_SQLLOG              21  /* xSqllog, void* */
    2210
    #define SQLITE_CONFIG_MMAP_SIZE           22  /* sqlite3_int64, sqlite3_int64 */
    2211
    #define SQLITE_CONFIG_WIN32_HEAPSIZE      23  /* int nByte */
    2212
    #define SQLITE_CONFIG_PCACHE_HDRSZ        24  /* int *psz */
    2213
    #define SQLITE_CONFIG_PMASZ               25  /* unsigned int szPma */
    2214
    #define SQLITE_CONFIG_STMTJRNL_SPILL      26  /* int nByte */
    2215
    #define SQLITE_CONFIG_SMALL_MALLOC        27  /* boolean */
    2216
    #define SQLITE_CONFIG_SORTERREF_SIZE      28  /* int nByte */
    2217
    #define SQLITE_CONFIG_MEMDB_MAXSIZE       29  /* sqlite3_int64 */
    2218
    #define SQLITE_CONFIG_ROWID_IN_VIEW       30  /* int* */
    2219
    2220
    /*
    2221
    ** CAPI3REF: Database Connection Configuration Options
    2222
    **
    2223
    ** These constants are the available integer configuration options that
    2224
    ** can be passed as the second parameter to the [sqlite3_db_config()] interface.
    2225
    **
    2226
    ** The [sqlite3_db_config()] interface is a var-args functions.  It takes a
    2227
    ** variable number of parameters, though always at least two.  The number of
    2228
    ** parameters passed into sqlite3_db_config() depends on which of these
    2229
    ** constants is given as the second parameter.  This documentation page
    2230
    ** refers to parameters beyond the second as "arguments".  Thus, when this
    2231
    ** page says "the N-th argument" it means "the N-th parameter past the
    2232
    ** configuration option" or "the (N+2)-th parameter to sqlite3_db_config()".
    2233
    **
    2234
    ** New configuration options may be added in future releases of SQLite.
    2235
    ** Existing configuration options might be discontinued.  Applications
    2236
    ** should check the return code from [sqlite3_db_config()] to make sure that
    2237
    ** the call worked.  ^The [sqlite3_db_config()] interface will return a
    2238
    ** non-zero [error code] if a discontinued or unsupported configuration option
    2239
    ** is invoked.
    2240
    **
    2241
    ** <dl>
    2242
    ** [[SQLITE_DBCONFIG_LOOKASIDE]]
    2243
    ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
    2244
    ** <dd> The SQLITE_DBCONFIG_LOOKASIDE option is used to adjust the
    2245
    ** configuration of the [lookaside memory allocator] within a database
    2246
    ** connection.
    2247
    ** The arguments to the SQLITE_DBCONFIG_LOOKASIDE option are <i>not</i>
    2248
    ** in the [DBCONFIG arguments|usual format].
    2249
    ** The SQLITE_DBCONFIG_LOOKASIDE option takes three arguments, not two,
    2250
    ** so that a call to [sqlite3_db_config()] that uses SQLITE_DBCONFIG_LOOKASIDE
    2251
    ** should have a total of five parameters.
    2252
    ** <ol>
    2253
    ** <li><p>The first argument ("buf") is a
    2254
    ** pointer to a memory buffer to use for lookaside memory.
    2255
    ** The first argument may be NULL in which case SQLite will allocate the
    2256
    ** lookaside buffer itself using [sqlite3_malloc()].
    2257
    ** <li><P>The second argument ("sz") is the
    2258
    ** size of each lookaside buffer slot.  Lookaside is disabled if "sz"
    2259
    ** is less than 8.  The "sz" argument should be a multiple of 8 less than
    2260
    ** 65536.  If "sz" does not meet this constraint, it is reduced in size until
    2261
    ** it does.
    2262
    ** <li><p>The third argument ("cnt") is the number of slots. Lookaside is disabled
    2263
    ** if "cnt"is less than 1.  The "cnt" value will be reduced, if necessary, so
    2264
    ** that the product of "sz" and "cnt" does not exceed 2,147,418,112.  The "cnt"
    2265
    ** parameter is usually chosen so that the product of "sz" and "cnt" is less
    2266
    ** than 1,000,000.
    2267
    ** </ol>
    2268
    ** <p>If the "buf" argument is not NULL, then it must
    2269
    ** point to a memory buffer with a size that is greater than
    2270
    ** or equal to the product of "sz" and "cnt".
    2271
    ** The buffer must be aligned to an 8-byte boundary.
    2272
    ** The lookaside memory
    2273
    ** configuration for a database connection can only be changed when that
    2274
    ** connection is not currently using lookaside memory, or in other words
    2275
    ** when the value returned by [SQLITE_DBSTATUS_LOOKASIDE_USED] is zero.
    2276
    ** Any attempt to change the lookaside memory configuration when lookaside
    2277
    ** memory is in use leaves the configuration unchanged and returns
    2278
    ** [SQLITE_BUSY].
    2279
    ** If the "buf" argument is NULL and an attempt
    2280
    ** to allocate memory based on "sz" and "cnt" fails, then
    2281
    ** lookaside is silently disabled.
    2282
    ** <p>
    2283
    ** The [SQLITE_CONFIG_LOOKASIDE] configuration option can be used to set the
    2284
    ** default lookaside configuration at initialization.  The
    2285
    ** [-DSQLITE_DEFAULT_LOOKASIDE] option can be used to set the default lookaside
    2286
    ** configuration at compile-time.  Typical values for lookaside are 1200 for
    2287
    ** "sz" and 40 to 100 for "cnt".
    2288
    ** </dd>
    2289
    **
    2290
    ** [[SQLITE_DBCONFIG_ENABLE_FKEY]]
    2291
    ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt>
    2292
    ** <dd> ^This option is used to enable or disable the enforcement of
    2293
    ** [foreign key constraints].  This is the same setting that is
    2294
    ** enabled or disabled by the [PRAGMA foreign_keys] statement.
    2295
    ** The first argument is an integer which is 0 to disable FK enforcement,
    2296
    ** positive to enable FK enforcement or negative to leave FK enforcement
    2297
    ** unchanged.  The second parameter is a pointer to an integer into which
    2298
    ** is written 0 or 1 to indicate whether FK enforcement is off or on
    2299
    ** following this call.  The second parameter may be a NULL pointer, in
    2300
    ** which case the FK enforcement setting is not reported back. </dd>
    2301
    **
    2302
    ** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]]
    2303
    ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt>
    2304
    ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].
    2305
    ** There should be two additional arguments.
    2306
    ** The first argument is an integer which is 0 to disable triggers,
    2307
    ** positive to enable triggers or negative to leave the setting unchanged.
    2308
    ** The second parameter is a pointer to an integer into which
    2309
    ** is written 0 or 1 to indicate whether triggers are disabled or enabled
    2310
    ** following this call.  The second parameter may be a NULL pointer, in
    2311
    ** which case the trigger setting is not reported back.
    2312
    **
    2313
    ** <p>Originally this option disabled all triggers.  ^(However, since
    2314
    ** SQLite version 3.35.0, TEMP triggers are still allowed even if
    2315
    ** this option is off.  So, in other words, this option now only disables
    2316
    ** triggers in the main database schema or in the schemas of [ATTACH]-ed
    2317
    ** databases.)^ </dd>
    2318
    **
    2319
    ** [[SQLITE_DBCONFIG_ENABLE_VIEW]]
    2320
    ** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt>
    2321
    ** <dd> ^This option is used to enable or disable [CREATE VIEW | views].
    2322
    ** There must be two additional arguments.
    2323
    ** The first argument is an integer which is 0 to disable views,
    2324
    ** positive to enable views or negative to leave the setting unchanged.
    2325
    ** The second parameter is a pointer to an integer into which
    2326
    ** is written 0 or 1 to indicate whether views are disabled or enabled
    2327
    ** following this call.  The second parameter may be a NULL pointer, in
    2328
    ** which case the view setting is not reported back.
    2329
    **
    2330
    ** <p>Originally this option disabled all views.  ^(However, since
    2331
    ** SQLite version 3.35.0, TEMP views are still allowed even if
    2332
    ** this option is off.  So, in other words, this option now only disables
    2333
    ** views in the main database schema or in the schemas of ATTACH-ed
    2334
    ** databases.)^ </dd>
    2335
    **
    2336
    ** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]]
    2337
    ** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt>
    2338
    ** <dd> ^This option is used to enable or disable the
    2339
    ** [fts3_tokenizer()] function which is part of the
    2340
    ** [FTS3] full-text search engine extension.
    2341
    ** There must be two additional arguments.
    2342
    ** The first argument is an integer which is 0 to disable fts3_tokenizer() or
    2343
    ** positive to enable fts3_tokenizer() or negative to leave the setting
    2344
    ** unchanged.
    2345
    ** The second parameter is a pointer to an integer into which
    2346
    ** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled
    2347
    ** following this call.  The second parameter may be a NULL pointer, in
    2348
    ** which case the new setting is not reported back. </dd>
    2349
    **
    2350
    ** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]]
    2351
    ** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt>
    2352
    ** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()]
    2353
    ** interface independently of the [load_extension()] SQL function.
    2354
    ** The [sqlite3_enable_load_extension()] API enables or disables both the
    2355
    ** C-API [sqlite3_load_extension()] and the SQL function [load_extension()].
    2356
    ** There must be two additional arguments.
    2357
    ** When the first argument to this interface is 1, then only the C-API is
    2358
    ** enabled and the SQL function remains disabled.  If the first argument to
    2359
    ** this interface is 0, then both the C-API and the SQL function are disabled.
    2360
    ** If the first argument is -1, then no changes are made to state of either the
    2361
    ** C-API or the SQL function.
    2362
    ** The second parameter is a pointer to an integer into which
    2363
    ** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface
    2364
    ** is disabled or enabled following this call.  The second parameter may
    2365
    ** be a NULL pointer, in which case the new setting is not reported back.
    2366
    ** </dd>
    2367
    **
    2368
    ** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt>
    2369
    ** <dd> ^This option is used to change the name of the "main" database
    2370
    ** schema.  This option does not follow the
    2371
    ** [DBCONFIG arguments|usual SQLITE_DBCONFIG argument format].
    2372
    ** This option takes exactly one additional argument so that the
    2373
    ** [sqlite3_db_config()] call has a total of three parameters.  The
    2374
    ** extra argument must be a pointer to a constant UTF8 string which
    2375
    ** will become the new schema name in place of "main".  ^SQLite does
    2376
    ** not make a copy of the new main schema name string, so the application
    2377
    ** must ensure that the argument passed into SQLITE_DBCONFIG MAINDBNAME
    2378
    ** is unchanged until after the database connection closes.
    2379
    ** </dd>
    2380
    **
    2381
    ** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]]
    2382
    ** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt>
    2383
    ** <dd> Usually, when a database in [WAL mode] is closed or detached from a
    2384
    ** database handle, SQLite checks if if there are other connections to the
    2385
    ** same database, and if there are no other database connection (if the
    2386
    ** connection being closed is the last open connection to the database),
    2387
    ** then SQLite performs a [checkpoint] before closing the connection and
    2388
    ** deletes the WAL file.  The SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE option can
    2389
    ** be used to override that behavior. The first argument passed to this
    2390
    ** operation (the third parameter to [sqlite3_db_config()]) is an integer
    2391
    ** which is positive to disable checkpoints-on-close, or zero (the default)
    2392
    ** to enable them, and negative to leave the setting unchanged.
    2393
    ** The second argument (the fourth parameter) is a pointer to an integer
    2394
    ** into which is written 0 or 1 to indicate whether checkpoints-on-close
    2395
    ** have been disabled - 0 if they are not disabled, 1 if they are.
    2396
    ** </dd>
    2397
    **
    2398
    ** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt>
    2399
    ** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates
    2400
    ** the [query planner stability guarantee] (QPSG).  When the QPSG is active,
    2401
    ** a single SQL query statement will always use the same algorithm regardless
    2402
    ** of values of [bound parameters].)^ The QPSG disables some query optimizations
    2403
    ** that look at the values of bound parameters, which can make some queries
    2404
    ** slower.  But the QPSG has the advantage of more predictable behavior.  With
    2405
    ** the QPSG active, SQLite will always use the same query plan in the field as
    2406
    ** was used during testing in the lab.
    2407
    ** The first argument to this setting is an integer which is 0 to disable
    2408
    ** the QPSG, positive to enable QPSG, or negative to leave the setting
    2409
    ** unchanged. The second parameter is a pointer to an integer into which
    2410
    ** is written 0 or 1 to indicate whether the QPSG is disabled or enabled
    2411
    ** following this call.
    2412
    ** </dd>
    2413
    **
    2414
    ** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt>
    2415
    ** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not
    2416
    ** include output for any operations performed by trigger programs. This
    2417
    ** option is used to set or clear (the default) a flag that governs this
    2418
    ** behavior. The first parameter passed to this operation is an integer -
    2419
    ** positive to enable output for trigger programs, or zero to disable it,
    2420
    ** or negative to leave the setting unchanged.
    2421
    ** The second parameter is a pointer to an integer into which is written
    2422
    ** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if
    2423
    ** it is not disabled, 1 if it is.
    2424
    ** </dd>
    2425
    **
    2426
    ** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt>
    2427
    ** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run
    2428
    ** [VACUUM] in order to reset a database back to an empty database
    2429
    ** with no schema and no content. The following process works even for
    2430
    ** a badly corrupted database file:
    2431
    ** <ol>
    2432
    ** <li> If the database connection is newly opened, make sure it has read the
    2433
    **      database schema by preparing then discarding some query against the
    2434
    **      database, or calling sqlite3_table_column_metadata(), ignoring any
    2435
    **      errors.  This step is only necessary if the application desires to keep
    2436
    **      the database in WAL mode after the reset if it was in WAL mode before
    2437
    **      the reset.
    2438
    ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0);
    2439
    ** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0);
    2440
    ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0);
    2441
    ** </ol>
    2442
    ** Because resetting a database is destructive and irreversible, the
    2443
    ** process requires the use of this obscure API and multiple steps to
    2444
    ** help ensure that it does not happen by accident. Because this
    2445
    ** feature must be capable of resetting corrupt databases, and
    2446
    ** shutting down virtual tables may require access to that corrupt
    2447
    ** storage, the library must abandon any installed virtual tables
    2448
    ** without calling their xDestroy() methods.
    2449
    **
    2450
    ** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt>
    2451
    ** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the
    2452
    ** "defensive" flag for a database connection.  When the defensive
    2453
    ** flag is enabled, language features that allow ordinary SQL to
    2454
    ** deliberately corrupt the database file are disabled.  The disabled
    2455
    ** features include but are not limited to the following:
    2456
    ** <ul>
    2457
    ** <li> The [PRAGMA writable_schema=ON] statement.
    2458
    ** <li> The [PRAGMA journal_mode=OFF] statement.
    2459
    ** <li> The [PRAGMA schema_version=N] statement.
    2460
    ** <li> Writes to the [sqlite_dbpage] virtual table.
    2461
    ** <li> Direct writes to [shadow tables].
    2462
    ** </ul>
    2463
    ** </dd>
    2464
    **
    2465
    ** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt>
    2466
    ** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the
    2467
    ** "writable_schema" flag. This has the same effect and is logically equivalent
    2468
    ** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF].
    2469
    ** The first argument to this setting is an integer which is 0 to disable
    2470
    ** the writable_schema, positive to enable writable_schema, or negative to
    2471
    ** leave the setting unchanged. The second parameter is a pointer to an
    2472
    ** integer into which is written 0 or 1 to indicate whether the writable_schema
    2473
    ** is enabled or disabled following this call.
    2474
    ** </dd>
    2475
    **
    2476
    ** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]]
    2477
    ** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt>
    2478
    ** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates
    2479
    ** the legacy behavior of the [ALTER TABLE RENAME] command such it
    2480
    ** behaves as it did prior to [version 3.24.0] (2018-06-04).  See the
    2481
    ** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for
    2482
    ** additional information. This feature can also be turned on and off
    2483
    ** using the [PRAGMA legacy_alter_table] statement.
    2484
    ** </dd>
    2485
    **
    2486
    ** [[SQLITE_DBCONFIG_DQS_DML]]
    2487
    ** <dt>SQLITE_DBCONFIG_DQS_DML</dt>
    2488
    ** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates
    2489
    ** the legacy [double-quoted string literal] misfeature for DML statements
    2490
    ** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The
    2491
    ** default value of this setting is determined by the [-DSQLITE_DQS]
    2492
    ** compile-time option.
    2493
    ** </dd>
    2494
    **
    2495
    ** [[SQLITE_DBCONFIG_DQS_DDL]]
    2496
    ** <dt>SQLITE_DBCONFIG_DQS_DDL</dt>
    2497
    ** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates
    2498
    ** the legacy [double-quoted string literal] misfeature for DDL statements,
    2499
    ** such as CREATE TABLE and CREATE INDEX. The
    2500
    ** default value of this setting is determined by the [-DSQLITE_DQS]
    2501
    ** compile-time option.
    2502
    ** </dd>
    2503
    **
    2504
    ** [[SQLITE_DBCONFIG_TRUSTED_SCHEMA]]
    2505
    ** <dt>SQLITE_DBCONFIG_TRUSTED_SCHEMA</dt>
    2506
    ** <dd>The SQLITE_DBCONFIG_TRUSTED_SCHEMA option tells SQLite to
    2507
    ** assume that database schemas are untainted by malicious content.
    2508
    ** When the SQLITE_DBCONFIG_TRUSTED_SCHEMA option is disabled, SQLite
    2509
    ** takes additional defensive steps to protect the application from harm
    2510
    ** including:
    2511
    ** <ul>
    2512
    ** <li> Prohibit the use of SQL functions inside triggers, views,
    2513
    ** CHECK constraints, DEFAULT clauses, expression indexes,
    2514
    ** partial indexes, or generated columns
    2515
    ** unless those functions are tagged with [SQLITE_INNOCUOUS].
    2516
    ** <li> Prohibit the use of virtual tables inside of triggers or views
    2517
    ** unless those virtual tables are tagged with [SQLITE_VTAB_INNOCUOUS].
    2518
    ** </ul>
    2519
    ** This setting defaults to "on" for legacy compatibility, however
    2520
    ** all applications are advised to turn it off if possible. This setting
    2521
    ** can also be controlled using the [PRAGMA trusted_schema] statement.
    2522
    ** </dd>
    2523
    **
    2524
    ** [[SQLITE_DBCONFIG_LEGACY_FILE_FORMAT]]
    2525
    ** <dt>SQLITE_DBCONFIG_LEGACY_FILE_FORMAT</dt>
    2526
    ** <dd>The SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option activates or deactivates
    2527
    ** the legacy file format flag.  When activated, this flag causes all newly
    2528
    ** created database file to have a schema format version number (the 4-byte
    2529
    ** integer found at offset 44 into the database header) of 1.  This in turn
    2530
    ** means that the resulting database file will be readable and writable by
    2531
    ** any SQLite version back to 3.0.0 ([dateof:3.0.0]).  Without this setting,
    2532
    ** newly created databases are generally not understandable by SQLite versions
    2533
    ** prior to 3.3.0 ([dateof:3.3.0]).  As these words are written, there
    2534
    ** is now scarcely any need to generate database files that are compatible
    2535
    ** all the way back to version 3.0.0, and so this setting is of little
    2536
    ** practical use, but is provided so that SQLite can continue to claim the
    2537
    ** ability to generate new database files that are compatible with  version
    2538
    ** 3.0.0.
    2539
    ** <p>Note that when the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT setting is on,
    2540
    ** the [VACUUM] command will fail with an obscure error when attempting to
    2541
    ** process a table with generated columns and a descending index.  This is
    2542
    ** not considered a bug since SQLite versions 3.3.0 and earlier do not support
    2543
    ** either generated columns or descending indexes.
    2544
    ** </dd>
    2545
    **
    2546
    ** [[SQLITE_DBCONFIG_STMT_SCANSTATUS]]
    2547
    ** <dt>SQLITE_DBCONFIG_STMT_SCANSTATUS</dt>
    2548
    ** <dd>The SQLITE_DBCONFIG_STMT_SCANSTATUS option is only useful in
    2549
    ** SQLITE_ENABLE_STMT_SCANSTATUS builds. In this case, it sets or clears
    2550
    ** a flag that enables collection of the sqlite3_stmt_scanstatus_v2()
    2551
    ** statistics. For statistics to be collected, the flag must be set on
    2552
    ** the database handle both when the SQL statement is prepared and when it
    2553
    ** is stepped. The flag is set (collection of statistics is enabled)
    2554
    ** by default. <p>This option takes two arguments: an integer and a pointer to
    2555
    ** an integer..  The first argument is 1, 0, or -1 to enable, disable, or
    2556
    ** leave unchanged the statement scanstatus option.  If the second argument
    2557
    ** is not NULL, then the value of the statement scanstatus setting after
    2558
    ** processing the first argument is written into the integer that the second
    2559
    ** argument points to.
    2560
    ** </dd>
    2561
    **
    2562
    ** [[SQLITE_DBCONFIG_REVERSE_SCANORDER]]
    2563
    ** <dt>SQLITE_DBCONFIG_REVERSE_SCANORDER</dt>
    2564
    ** <dd>The SQLITE_DBCONFIG_REVERSE_SCANORDER option changes the default order
    2565
    ** in which tables and indexes are scanned so that the scans start at the end
    2566
    ** and work toward the beginning rather than starting at the beginning and
    2567
    ** working toward the end. Setting SQLITE_DBCONFIG_REVERSE_SCANORDER is the
    2568
    ** same as setting [PRAGMA reverse_unordered_selects]. <p>This option takes
    2569
    ** two arguments which are an integer and a pointer to an integer.  The first
    2570
    ** argument is 1, 0, or -1 to enable, disable, or leave unchanged the
    2571
    ** reverse scan order flag, respectively.  If the second argument is not NULL,
    2572
    ** then 0 or 1 is written into the integer that the second argument points to
    2573
    ** depending on if the reverse scan order flag is set after processing the
    2574
    ** first argument.
    2575
    ** </dd>
    2576
    **
    2577
    ** [[SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE]]
    2578
    ** <dt>SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE</dt>
    2579
    ** <dd>The SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE option enables or disables
    2580
    ** the ability of the [ATTACH DATABASE] SQL command to create a new database
    2581
    ** file if the database filed named in the ATTACH command does not already
    2582
    ** exist.  This ability of ATTACH to create a new database is enabled by
    2583
    ** default.  Applications can disable or reenable the ability for ATTACH to
    2584
    ** create new database files using this DBCONFIG option.<p>
    2585
    ** This option takes two arguments which are an integer and a pointer
    2586
    ** to an integer.  The first argument is 1, 0, or -1 to enable, disable, or
    2587
    ** leave unchanged the attach-create flag, respectively.  If the second
    2588
    ** argument is not NULL, then 0 or 1 is written into the integer that the
    2589
    ** second argument points to depending on if the attach-create flag is set
    2590
    ** after processing the first argument.
    2591
    ** </dd>
    2592
    **
    2593
    ** [[SQLITE_DBCONFIG_ENABLE_ATTACH_WRITE]]
    2594
    ** <dt>SQLITE_DBCONFIG_ENABLE_ATTACH_WRITE</dt>
    2595
    ** <dd>The SQLITE_DBCONFIG_ENABLE_ATTACH_WRITE option enables or disables the
    2596
    ** ability of the [ATTACH DATABASE] SQL command to open a database for writing.
    2597
    ** This capability is enabled by default.  Applications can disable or
    2598
    ** reenable this capability using the current DBCONFIG option.  If the
    2599
    ** the this capability is disabled, the [ATTACH] command will still work,
    2600
    ** but the database will be opened read-only.  If this option is disabled,
    2601
    ** then the ability to create a new database using [ATTACH] is also disabled,
    2602
    ** regardless of the value of the [SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE]
    2603
    ** option.<p>
    2604
    ** This option takes two arguments which are an integer and a pointer
    2605
    ** to an integer.  The first argument is 1, 0, or -1 to enable, disable, or
    2606
    ** leave unchanged the ability to ATTACH another database for writing,
    2607
    ** respectively.  If the second argument is not NULL, then 0 or 1 is written
    2608
    ** into the integer to which the second argument points, depending on whether
    2609
    ** the ability to ATTACH a read/write database is enabled or disabled
    2610
    ** after processing the first argument.
    2611
    ** </dd>
    2612
    **
    2613
    ** [[SQLITE_DBCONFIG_ENABLE_COMMENTS]]
    2614
    ** <dt>SQLITE_DBCONFIG_ENABLE_COMMENTS</dt>
    2615
    ** <dd>The SQLITE_DBCONFIG_ENABLE_COMMENTS option enables or disables the
    2616
    ** ability to include comments in SQL text.  Comments are enabled by default.
    2617
    ** An application can disable or reenable comments in SQL text using this
    2618
    ** DBCONFIG option.<p>
    2619
    ** This option takes two arguments which are an integer and a pointer
    2620
    ** to an integer.  The first argument is 1, 0, or -1 to enable, disable, or
    2621
    ** leave unchanged the ability to use comments in SQL text,
    2622
    ** respectively.  If the second argument is not NULL, then 0 or 1 is written
    2623
    ** into the integer that the second argument points to depending on if
    2624
    ** comments are allowed in SQL text after processing the first argument.
    2625
    ** </dd>
    2626
    **
    2627
    ** </dl>
    2628
    **
    2629
    ** [[DBCONFIG arguments]] <h3>Arguments To SQLITE_DBCONFIG Options</h3>
    2630
    **
    2631
    ** <p>Most of the SQLITE_DBCONFIG options take two arguments, so that the
    2632
    ** overall call to [sqlite3_db_config()] has a total of four parameters.
    2633
    ** The first argument (the third parameter to sqlite3_db_config()) is a integer.
    2634
    ** The second argument is a pointer to an integer.  If the first argument is 1,
    2635
    ** then the option becomes enabled.  If the first integer argument is 0, then the
    2636
    ** option is disabled.  If the first argument is -1, then the option setting
    2637
    ** is unchanged.  The second argument, the pointer to an integer, may be NULL.
    2638
    ** If the second argument is not NULL, then a value of 0 or 1 is written into
    2639
    ** the integer to which the second argument points, depending on whether the
    2640
    ** setting is disabled or enabled after applying any changes specified by
    2641
    ** the first argument.
    2642
    **
    2643
    ** <p>While most SQLITE_DBCONFIG options use the argument format
    2644
    ** described in the previous paragraph, the [SQLITE_DBCONFIG_MAINDBNAME]
    2645
    ** and [SQLITE_DBCONFIG_LOOKASIDE] options are different.  See the
    2646
    ** documentation of those exceptional options for details.
    2647
    */
    2648
    #define SQLITE_DBCONFIG_MAINDBNAME            1000 /* const char* */
    2649
    #define SQLITE_DBCONFIG_LOOKASIDE             1001 /* void* int int */
    2650
    #define SQLITE_DBCONFIG_ENABLE_FKEY           1002 /* int int* */
    2651
    #define SQLITE_DBCONFIG_ENABLE_TRIGGER        1003 /* int int* */
    2652
    #define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */
    2653
    #define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */
    2654
    #define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE      1006 /* int int* */
    2655
    #define SQLITE_DBCONFIG_ENABLE_QPSG           1007 /* int int* */
    2656
    #define SQLITE_DBCONFIG_TRIGGER_EQP           1008 /* int int* */
    2657
    #define SQLITE_DBCONFIG_RESET_DATABASE        1009 /* int int* */
    2658
    #define SQLITE_DBCONFIG_DEFENSIVE             1010 /* int int* */
    2659
    #define SQLITE_DBCONFIG_WRITABLE_SCHEMA       1011 /* int int* */
    2660
    #define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE    1012 /* int int* */
    2661
    #define SQLITE_DBCONFIG_DQS_DML               1013 /* int int* */
    2662
    #define SQLITE_DBCONFIG_DQS_DDL               1014 /* int int* */
    2663
    #define SQLITE_DBCONFIG_ENABLE_VIEW           1015 /* int int* */
    2664
    #define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT    1016 /* int int* */
    2665
    #define SQLITE_DBCONFIG_TRUSTED_SCHEMA        1017 /* int int* */
    2666
    #define SQLITE_DBCONFIG_STMT_SCANSTATUS       1018 /* int int* */
    2667
    #define SQLITE_DBCONFIG_REVERSE_SCANORDER     1019 /* int int* */
    2668
    #define SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE  1020 /* int int* */
    2669
    #define SQLITE_DBCONFIG_ENABLE_ATTACH_WRITE   1021 /* int int* */
    2670
    #define SQLITE_DBCONFIG_ENABLE_COMMENTS       1022 /* int int* */
    2671
    #define SQLITE_DBCONFIG_MAX                   1022 /* Largest DBCONFIG */
    2672
    2673
    /*
    2674
    ** CAPI3REF: Enable Or Disable Extended Result Codes
    2675
    ** METHOD: sqlite3
    2676
    **
    2677
    ** ^The sqlite3_extended_result_codes() routine enables or disables the
    2678
    ** [extended result codes] feature of SQLite. ^The extended result
    2679
    ** codes are disabled by default for historical compatibility.
    2680
    */
    2681
    SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff);
    2682
    2683
    /*
    2684
    ** CAPI3REF: Last Insert Rowid
    2685
    ** METHOD: sqlite3
    2686
    **
    2687
    ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables)
    2688
    ** has a unique 64-bit signed
    2689
    ** integer key called the [ROWID | "rowid"]. ^The rowid is always available
    2690
    ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
    2691
    ** names are not also used by explicitly declared columns. ^If
    2692
    ** the table has a column of type [INTEGER PRIMARY KEY] then that column
    2693
    ** is another alias for the rowid.
    2694
    **
    2695
    ** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of
    2696
    ** the most recent successful [INSERT] into a rowid table or [virtual table]
    2697
    ** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not
    2698
    ** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred
    2699
    ** on the database connection D, then sqlite3_last_insert_rowid(D) returns
    2700
    ** zero.
    2701
    **
    2702
    ** As well as being set automatically as rows are inserted into database
    2703
    ** tables, the value returned by this function may be set explicitly by
    2704
    ** [sqlite3_set_last_insert_rowid()]
    2705
    **
    2706
    ** Some virtual table implementations may INSERT rows into rowid tables as
    2707
    ** part of committing a transaction (e.g. to flush data accumulated in memory
    2708
    ** to disk). In this case subsequent calls to this function return the rowid
    2709
    ** associated with these internal INSERT operations, which leads to
    2710
    ** unintuitive results. Virtual table implementations that do write to rowid
    2711
    ** tables in this way can avoid this problem by restoring the original
    2712
    ** rowid value using [sqlite3_set_last_insert_rowid()] before returning
    2713
    ** control to the user.
    2714
    **
    2715
    ** ^(If an [INSERT] occurs within a trigger then this routine will
    2716
    ** return the [rowid] of the inserted row as long as the trigger is
    2717
    ** running. Once the trigger program ends, the value returned
    2718
    ** by this routine reverts to what it was before the trigger was fired.)^
    2719
    **
    2720
    ** ^An [INSERT] that fails due to a constraint violation is not a
    2721
    ** successful [INSERT] and does not change the value returned by this
    2722
    ** routine.  ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
    2723
    ** and INSERT OR ABORT make no changes to the return value of this
    2724
    ** routine when their insertion fails.  ^(When INSERT OR REPLACE
    2725
    ** encounters a constraint violation, it does not fail.  The
    2726
    ** INSERT continues to completion after deleting rows that caused
    2727
    ** the constraint problem so INSERT OR REPLACE will always change
    2728
    ** the return value of this interface.)^
    2729
    **
    2730
    ** ^For the purposes of this routine, an [INSERT] is considered to
    2731
    ** be successful even if it is subsequently rolled back.
    2732
    **
    2733
    ** This function is accessible to SQL statements via the
    2734
    ** [last_insert_rowid() SQL function].
    2735
    **
    2736
    ** If a separate thread performs a new [INSERT] on the same
    2737
    ** database connection while the [sqlite3_last_insert_rowid()]
    2738
    ** function is running and thus changes the last insert [rowid],
    2739
    ** then the value returned by [sqlite3_last_insert_rowid()] is
    2740
    ** unpredictable and might not equal either the old or the new
    2741
    ** last insert [rowid].
    2742
    */
    2743
    SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);
    2744
    2745
    /*
    2746
    ** CAPI3REF: Set the Last Insert Rowid value.
    2747
    ** METHOD: sqlite3
    2748
    **
    2749
    ** The sqlite3_set_last_insert_rowid(D, R) method allows the application to
    2750
    ** set the value returned by calling sqlite3_last_insert_rowid(D) to R
    2751
    ** without inserting a row into the database.
    2752
    */
    2753
    SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64);
    2754
    2755
    /*
    2756
    ** CAPI3REF: Count The Number Of Rows Modified
    2757
    ** METHOD: sqlite3
    2758
    **
    2759
    ** ^These functions return the number of rows modified, inserted or
    2760
    ** deleted by the most recently completed INSERT, UPDATE or DELETE
    2761
    ** statement on the database connection specified by the only parameter.
    2762
    ** The two functions are identical except for the type of the return value
    2763
    ** and that if the number of rows modified by the most recent INSERT, UPDATE,
    2764
    ** or DELETE is greater than the maximum value supported by type "int", then
    2765
    ** the return value of sqlite3_changes() is undefined. ^Executing any other
    2766
    ** type of SQL statement does not modify the value returned by these functions.
    2767
    ** For the purposes of this interface, a CREATE TABLE AS SELECT statement
    2768
    ** does not count as an INSERT, UPDATE or DELETE statement and hence the rows
    2769
    ** added to the new table by the CREATE TABLE AS SELECT statement are not
    2770
    ** counted.
    2771
    **
    2772
    ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are
    2773
    ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers],
    2774
    ** [foreign key actions] or [REPLACE] constraint resolution are not counted.
    2775
    **
    2776
    ** Changes to a view that are intercepted by
    2777
    ** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value
    2778
    ** returned by sqlite3_changes() immediately after an INSERT, UPDATE or
    2779
    ** DELETE statement run on a view is always zero. Only changes made to real
    2780
    ** tables are counted.
    2781
    **
    2782
    ** Things are more complicated if the sqlite3_changes() function is
    2783
    ** executed while a trigger program is running. This may happen if the
    2784
    ** program uses the [changes() SQL function], or if some other callback
    2785
    ** function invokes sqlite3_changes() directly. Essentially:
    2786
    **
    2787
    ** <ul>
    2788
    **   <li> ^(Before entering a trigger program the value returned by
    2789
    **        sqlite3_changes() function is saved. After the trigger program
    2790
    **        has finished, the original value is restored.)^
    2791
    **
    2792
    **   <li> ^(Within a trigger program each INSERT, UPDATE and DELETE
    2793
    **        statement sets the value returned by sqlite3_changes()
    2794
    **        upon completion as normal. Of course, this value will not include
    2795
    **        any changes performed by sub-triggers, as the sqlite3_changes()
    2796
    **        value will be saved and restored after each sub-trigger has run.)^
    2797
    ** </ul>
    2798
    **
    2799
    ** ^This means that if the changes() SQL function (or similar) is used
    2800
    ** by the first INSERT, UPDATE or DELETE statement within a trigger, it
    2801
    ** returns the value as set when the calling statement began executing.
    2802
    ** ^If it is used by the second or subsequent such statement within a trigger
    2803
    ** program, the value returned reflects the number of rows modified by the
    2804
    ** previous INSERT, UPDATE or DELETE statement within the same trigger.
    2805
    **
    2806
    ** If a separate thread makes changes on the same database connection
    2807
    ** while [sqlite3_changes()] is running then the value returned
    2808
    ** is unpredictable and not meaningful.
    2809
    **
    2810
    ** See also:
    2811
    ** <ul>
    2812
    ** <li> the [sqlite3_total_changes()] interface
    2813
    ** <li> the [count_changes pragma]
    2814
    ** <li> the [changes() SQL function]
    2815
    ** <li> the [data_version pragma]
    2816
    ** </ul>
    2817
    */
    2818
    SQLITE_API int sqlite3_changes(sqlite3*);
    2819
    SQLITE_API sqlite3_int64 sqlite3_changes64(sqlite3*);
    2820
    2821
    /*
    2822
    ** CAPI3REF: Total Number Of Rows Modified
    2823
    ** METHOD: sqlite3
    2824
    **
    2825
    ** ^These functions return the total number of rows inserted, modified or
    2826
    ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed
    2827
    ** since the database connection was opened, including those executed as
    2828
    ** part of trigger programs. The two functions are identical except for the
    2829
    ** type of the return value and that if the number of rows modified by the
    2830
    ** connection exceeds the maximum value supported by type "int", then
    2831
    ** the return value of sqlite3_total_changes() is undefined. ^Executing
    2832
    ** any other type of SQL statement does not affect the value returned by
    2833
    ** sqlite3_total_changes().
    2834
    **
    2835
    ** ^Changes made as part of [foreign key actions] are included in the
    2836
    ** count, but those made as part of REPLACE constraint resolution are
    2837
    ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers
    2838
    ** are not counted.
    2839
    **
    2840
    ** The [sqlite3_total_changes(D)] interface only reports the number
    2841
    ** of rows that changed due to SQL statement run against database
    2842
    ** connection D.  Any changes by other database connections are ignored.
    2843
    ** To detect changes against a database file from other database
    2844
    ** connections use the [PRAGMA data_version] command or the
    2845
    ** [SQLITE_FCNTL_DATA_VERSION] [file control].
    2846
    **
    2847
    ** If a separate thread makes changes on the same database connection
    2848
    ** while [sqlite3_total_changes()] is running then the value
    2849
    ** returned is unpredictable and not meaningful.
    2850
    **
    2851
    ** See also:
    2852
    ** <ul>
    2853
    ** <li> the [sqlite3_changes()] interface
    2854
    ** <li> the [count_changes pragma]
    2855
    ** <li> the [changes() SQL function]
    2856
    ** <li> the [data_version pragma]
    2857
    ** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control]
    2858
    ** </ul>
    2859
    */
    2860
    SQLITE_API int sqlite3_total_changes(sqlite3*);
    2861
    SQLITE_API sqlite3_int64 sqlite3_total_changes64(sqlite3*);
    2862
    2863
    /*
    2864
    ** CAPI3REF: Interrupt A Long-Running Query
    2865
    ** METHOD: sqlite3
    2866
    **
    2867
    ** ^This function causes any pending database operation to abort and
    2868
    ** return at its earliest opportunity. This routine is typically
    2869
    ** called in response to a user action such as pressing "Cancel"
    2870
    ** or Ctrl-C where the user wants a long query operation to halt
    2871
    ** immediately.
    2872
    **
    2873
    ** ^It is safe to call this routine from a thread different from the
    2874
    ** thread that is currently running the database operation.  But it
    2875
    ** is not safe to call this routine with a [database connection] that
    2876
    ** is closed or might close before sqlite3_interrupt() returns.
    2877
    **
    2878
    ** ^If an SQL operation is very nearly finished at the time when
    2879
    ** sqlite3_interrupt() is called, then it might not have an opportunity
    2880
    ** to be interrupted and might continue to completion.
    2881
    **
    2882
    ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
    2883
    ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
    2884
    ** that is inside an explicit transaction, then the entire transaction
    2885
    ** will be rolled back automatically.
    2886
    **
    2887
    ** ^The sqlite3_interrupt(D) call is in effect until all currently running
    2888
    ** SQL statements on [database connection] D complete.  ^Any new SQL statements
    2889
    ** that are started after the sqlite3_interrupt() call and before the
    2890
    ** running statement count reaches zero are interrupted as if they had been
    2891
    ** running prior to the sqlite3_interrupt() call.  ^New SQL statements
    2892
    ** that are started after the running statement count reaches zero are
    2893
    ** not effected by the sqlite3_interrupt().
    2894
    ** ^A call to sqlite3_interrupt(D) that occurs when there are no running
    2895
    ** SQL statements is a no-op and has no effect on SQL statements
    2896
    ** that are started after the sqlite3_interrupt() call returns.
    2897
    **
    2898
    ** ^The [sqlite3_is_interrupted(D)] interface can be used to determine whether
    2899
    ** or not an interrupt is currently in effect for [database connection] D.
    2900
    ** It returns 1 if an interrupt is currently in effect, or 0 otherwise.
    2901
    */
    2902
    SQLITE_API void sqlite3_interrupt(sqlite3*);
    2903
    SQLITE_API int sqlite3_is_interrupted(sqlite3*);
    2904
    2905
    /*
    2906
    ** CAPI3REF: Determine If An SQL Statement Is Complete
    2907
    **
    2908
    ** These routines are useful during command-line input to determine if the
    2909
    ** currently entered text seems to form a complete SQL statement or
    2910
    ** if additional input is needed before sending the text into
    2911
    ** SQLite for parsing.  ^These routines return 1 if the input string
    2912
    ** appears to be a complete SQL statement.  ^A statement is judged to be
    2913
    ** complete if it ends with a semicolon token and is not a prefix of a
    2914
    ** well-formed CREATE TRIGGER statement.  ^Semicolons that are embedded within
    2915
    ** string literals or quoted identifier names or comments are not
    2916
    ** independent tokens (they are part of the token in which they are
    2917
    ** embedded) and thus do not count as a statement terminator.  ^Whitespace
    2918
    ** and comments that follow the final semicolon are ignored.
    2919
    **
    2920
    ** ^These routines return 0 if the statement is incomplete.  ^If a
    2921
    ** memory allocation fails, then SQLITE_NOMEM is returned.
    2922
    **
    2923
    ** ^These routines do not parse the SQL statements thus
    2924
    ** will not detect syntactically incorrect SQL.
    2925
    **
    2926
    ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior
    2927
    ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
    2928
    ** automatically by sqlite3_complete16().  If that initialization fails,
    2929
    ** then the return value from sqlite3_complete16() will be non-zero
    2930
    ** regardless of whether or not the input SQL is complete.)^
    2931
    **
    2932
    ** The input to [sqlite3_complete()] must be a zero-terminated
    2933
    ** UTF-8 string.
    2934
    **
    2935
    ** The input to [sqlite3_complete16()] must be a zero-terminated
    2936
    ** UTF-16 string in native byte order.
    2937
    */
    2938
    SQLITE_API int sqlite3_complete(const char *sql);
    2939
    SQLITE_API int sqlite3_complete16(const void *sql);
    2940
    2941
    /*
    2942
    ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
    2943
    ** KEYWORDS: {busy-handler callback} {busy handler}
    2944
    ** METHOD: sqlite3
    2945
    **
    2946
    ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X
    2947
    ** that might be invoked with argument P whenever
    2948
    ** an attempt is made to access a database table associated with
    2949
    ** [database connection] D when another thread
    2950
    ** or process has the table locked.
    2951
    ** The sqlite3_busy_handler() interface is used to implement
    2952
    ** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout].
    2953
    **
    2954
    ** ^If the busy callback is NULL, then [SQLITE_BUSY]
    2955
    ** is returned immediately upon encountering the lock.  ^If the busy callback
    2956
    ** is not NULL, then the callback might be invoked with two arguments.
    2957
    **
    2958
    ** ^The first argument to the busy handler is a copy of the void* pointer which
    2959
    ** is the third argument to sqlite3_busy_handler().  ^The second argument to
    2960
    ** the busy handler callback is the number of times that the busy handler has
    2961
    ** been invoked previously for the same locking event.  ^If the
    2962
    ** busy callback returns 0, then no additional attempts are made to
    2963
    ** access the database and [SQLITE_BUSY] is returned
    2964
    ** to the application.
    2965
    ** ^If the callback returns non-zero, then another attempt
    2966
    ** is made to access the database and the cycle repeats.
    2967
    **
    2968
    ** The presence of a busy handler does not guarantee that it will be invoked
    2969
    ** when there is lock contention. ^If SQLite determines that invoking the busy
    2970
    ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
    2971
    ** to the application instead of invoking the
    2972
    ** busy handler.
    2973
    ** Consider a scenario where one process is holding a read lock that
    2974
    ** it is trying to promote to a reserved lock and
    2975
    ** a second process is holding a reserved lock that it is trying
    2976
    ** to promote to an exclusive lock.  The first process cannot proceed
    2977
    ** because it is blocked by the second and the second process cannot
    2978
    ** proceed because it is blocked by the first.  If both processes
    2979
    ** invoke the busy handlers, neither will make any progress.  Therefore,
    2980
    ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
    2981
    ** will induce the first process to release its read lock and allow
    2982
    ** the second process to proceed.
    2983
    **
    2984
    ** ^The default busy callback is NULL.
    2985
    **
    2986
    ** ^(There can only be a single busy handler defined for each
    2987
    ** [database connection].  Setting a new busy handler clears any
    2988
    ** previously set handler.)^  ^Note that calling [sqlite3_busy_timeout()]
    2989
    ** or evaluating [PRAGMA busy_timeout=N] will change the
    2990
    ** busy handler and thus clear any previously set busy handler.
    2991
    **
    2992
    ** The busy callback should not take any actions which modify the
    2993
    ** database connection that invoked the busy handler.  In other words,
    2994
    ** the busy handler is not reentrant.  Any such actions
    2995
    ** result in undefined behavior.
    2996
    **
    2997
    ** A busy handler must not close the database connection
    2998
    ** or [prepared statement] that invoked the busy handler.
    2999
    */
    3000
    SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*);
    3001
    3002
    /*
    3003
    ** CAPI3REF: Set A Busy Timeout
    3004
    ** METHOD: sqlite3
    3005
    **
    3006
    ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
    3007
    ** for a specified amount of time when a table is locked.  ^The handler
    3008
    ** will sleep multiple times until at least "ms" milliseconds of sleeping
    3009
    ** have accumulated.  ^After at least "ms" milliseconds of sleeping,
    3010
    ** the handler returns 0 which causes [sqlite3_step()] to return
    3011
    ** [SQLITE_BUSY].
    3012
    **
    3013
    ** ^Calling this routine with an argument less than or equal to zero
    3014
    ** turns off all busy handlers.
    3015
    **
    3016
    ** ^(There can only be a single busy handler for a particular
    3017
    ** [database connection] at any given moment.  If another busy handler
    3018
    ** was defined  (using [sqlite3_busy_handler()]) prior to calling
    3019
    ** this routine, that other busy handler is cleared.)^
    3020
    **
    3021
    ** See also:  [PRAGMA busy_timeout]
    3022
    */
    3023
    SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms);
    3024
    3025
    /*
    3026
    ** CAPI3REF: Set the Setlk Timeout
    3027
    ** METHOD: sqlite3
    3028
    **
    3029
    ** This routine is only useful in SQLITE_ENABLE_SETLK_TIMEOUT builds. If
    3030
    ** the VFS supports blocking locks, it sets the timeout in ms used by
    3031
    ** eligible locks taken on wal mode databases by the specified database
    3032
    ** handle. In non-SQLITE_ENABLE_SETLK_TIMEOUT builds, or if the VFS does
    3033
    ** not support blocking locks, this function is a no-op.
    3034
    **
    3035
    ** Passing 0 to this function disables blocking locks altogether. Passing
    3036
    ** -1 to this function requests that the VFS blocks for a long time -
    3037
    ** indefinitely if possible. The results of passing any other negative value
    3038
    ** are undefined.
    3039
    **
    3040
    ** Internally, each SQLite database handle store two timeout values - the
    3041
    ** busy-timeout (used for rollback mode databases, or if the VFS does not
    3042
    ** support blocking locks) and the setlk-timeout (used for blocking locks
    3043
    ** on wal-mode databases). The sqlite3_busy_timeout() method sets both
    3044
    ** values, this function sets only the setlk-timeout value. Therefore,
    3045
    ** to configure separate busy-timeout and setlk-timeout values for a single
    3046
    ** database handle, call sqlite3_busy_timeout() followed by this function.
    3047
    **
    3048
    ** Whenever the number of connections to a wal mode database falls from
    3049
    ** 1 to 0, the last connection takes an exclusive lock on the database,
    3050
    ** then checkpoints and deletes the wal file. While it is doing this, any
    3051
    ** new connection that tries to read from the database fails with an
    3052
    ** SQLITE_BUSY error. Or, if the SQLITE_SETLK_BLOCK_ON_CONNECT flag is
    3053
    ** passed to this API, the new connection blocks until the exclusive lock
    3054
    ** has been released.
    3055
    */
    3056
    SQLITE_API int sqlite3_setlk_timeout(sqlite3*, int ms, int flags);
    3057
    3058
    /*
    3059
    ** CAPI3REF: Flags for sqlite3_setlk_timeout()
    3060
    */
    3061
    #define SQLITE_SETLK_BLOCK_ON_CONNECT 0x01
    3062
    3063
    /*
    3064
    ** CAPI3REF: Convenience Routines For Running Queries
    3065
    ** METHOD: sqlite3
    3066
    **
    3067
    ** This is a legacy interface that is preserved for backwards compatibility.
    3068
    ** Use of this interface is not recommended.
    3069
    **
    3070
    ** Definition: A <b>result table</b> is memory data structure created by the
    3071
    ** [sqlite3_get_table()] interface.  A result table records the
    3072
    ** complete query results from one or more queries.
    3073
    **
    3074
    ** The table conceptually has a number of rows and columns.  But
    3075
    ** these numbers are not part of the result table itself.  These
    3076
    ** numbers are obtained separately.  Let N be the number of rows
    3077
    ** and M be the number of columns.
    3078
    **
    3079
    ** A result table is an array of pointers to zero-terminated UTF-8 strings.
    3080
    ** There are (N+1)*M elements in the array.  The first M pointers point
    3081
    ** to zero-terminated strings that  contain the names of the columns.
    3082
    ** The remaining entries all point to query results.  NULL values result
    3083
    ** in NULL pointers.  All other values are in their UTF-8 zero-terminated
    3084
    ** string representation as returned by [sqlite3_column_text()].
    3085
    **
    3086
    ** A result table might consist of one or more memory allocations.
    3087
    ** It is not safe to pass a result table directly to [sqlite3_free()].
    3088
    ** A result table should be deallocated using [sqlite3_free_table()].
    3089
    **
    3090
    ** ^(As an example of the result table format, suppose a query result
    3091
    ** is as follows:
    3092
    **
    3093
    ** <blockquote><pre>
    3094
    **        Name        | Age
    3095
    **        -----------------------
    3096
    **        Alice       | 43
    3097
    **        Bob         | 28
    3098
    **        Cindy       | 21
    3099
    ** </pre></blockquote>
    3100
    **
    3101
    ** There are two columns (M==2) and three rows (N==3).  Thus the
    3102
    ** result table has 8 entries.  Suppose the result table is stored
    3103
    ** in an array named azResult.  Then azResult holds this content:
    3104
    **
    3105
    ** <blockquote><pre>
    3106
    **        azResult&#91;0] = "Name";
    3107
    **        azResult&#91;1] = "Age";
    3108
    **        azResult&#91;2] = "Alice";
    3109
    **        azResult&#91;3] = "43";
    3110
    **        azResult&#91;4] = "Bob";
    3111
    **        azResult&#91;5] = "28";
    3112
    **        azResult&#91;6] = "Cindy";
    3113
    **        azResult&#91;7] = "21";
    3114
    ** </pre></blockquote>)^
    3115
    **
    3116
    ** ^The sqlite3_get_table() function evaluates one or more
    3117
    ** semicolon-separated SQL statements in the zero-terminated UTF-8
    3118
    ** string of its 2nd parameter and returns a result table to the
    3119
    ** pointer given in its 3rd parameter.
    3120
    **
    3121
    ** After the application has finished with the result from sqlite3_get_table(),
    3122
    ** it must pass the result table pointer to sqlite3_free_table() in order to
    3123
    ** release the memory that was malloced.  Because of the way the
    3124
    ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
    3125
    ** function must not try to call [sqlite3_free()] directly.  Only
    3126
    ** [sqlite3_free_table()] is able to release the memory properly and safely.
    3127
    **
    3128
    ** The sqlite3_get_table() interface is implemented as a wrapper around
    3129
    ** [sqlite3_exec()].  The sqlite3_get_table() routine does not have access
    3130
    ** to any internal data structures of SQLite.  It uses only the public
    3131
    ** interface defined here.  As a consequence, errors that occur in the
    3132
    ** wrapper layer outside of the internal [sqlite3_exec()] call are not
    3133
    ** reflected in subsequent calls to [sqlite3_errcode()] or
    3134
    ** [sqlite3_errmsg()].
    3135
    */
    3136
    SQLITE_API int sqlite3_get_table(
    3137
      sqlite3 *db,          /* An open database */
    3138
      const char *zSql,     /* SQL to be evaluated */
    3139
      char ***pazResult,    /* Results of the query */
    3140
      int *pnRow,           /* Number of result rows written here */
    3141
      int *pnColumn,        /* Number of result columns written here */
    3142
      char **pzErrmsg       /* Error msg written here */
    3143
    );
    3144
    SQLITE_API void sqlite3_free_table(char **result);
    3145
    3146
    /*
    3147
    ** CAPI3REF: Formatted String Printing Functions
    3148
    **
    3149
    ** These routines are work-alikes of the "printf()" family of functions
    3150
    ** from the standard C library.
    3151
    ** These routines understand most of the common formatting options from
    3152
    ** the standard library printf()
    3153
    ** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]).
    3154
    ** See the [built-in printf()] documentation for details.
    3155
    **
    3156
    ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
    3157
    ** results into memory obtained from [sqlite3_malloc64()].
    3158
    ** The strings returned by these two routines should be
    3159
    ** released by [sqlite3_free()].  ^Both routines return a
    3160
    ** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough
    3161
    ** memory to hold the resulting string.
    3162
    **
    3163
    ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
    3164
    ** the standard C library.  The result is written into the
    3165
    ** buffer supplied as the second parameter whose size is given by
    3166
    ** the first parameter. Note that the order of the
    3167
    ** first two parameters is reversed from snprintf().)^  This is an
    3168
    ** historical accident that cannot be fixed without breaking
    3169
    ** backwards compatibility.  ^(Note also that sqlite3_snprintf()
    3170
    ** returns a pointer to its buffer instead of the number of
    3171
    ** characters actually written into the buffer.)^  We admit that
    3172
    ** the number of characters written would be a more useful return
    3173
    ** value but we cannot change the implementation of sqlite3_snprintf()
    3174
    ** now without breaking compatibility.
    3175
    **
    3176
    ** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
    3177
    ** guarantees that the buffer is always zero-terminated.  ^The first
    3178
    ** parameter "n" is the total size of the buffer, including space for
    3179
    ** the zero terminator.  So the longest string that can be completely
    3180
    ** written will be n-1 characters.
    3181
    **
    3182
    ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
    3183
    **
    3184
    ** See also:  [built-in printf()], [printf() SQL function]
    3185
    */
    3186
    SQLITE_API char *sqlite3_mprintf(const char*,...);
    3187
    SQLITE_API char *sqlite3_vmprintf(const char*, va_list);
    3188
    SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...);
    3189
    SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list);
    3190
    3191
    /*
    3192
    ** CAPI3REF: Memory Allocation Subsystem
    3193
    **
    3194
    ** The SQLite core uses these three routines for all of its own
    3195
    ** internal memory allocation needs. "Core" in the previous sentence
    3196
    ** does not include operating-system specific [VFS] implementation.  The
    3197
    ** Windows VFS uses native malloc() and free() for some operations.
    3198
    **
    3199
    ** ^The sqlite3_malloc() routine returns a pointer to a block
    3200
    ** of memory at least N bytes in length, where N is the parameter.
    3201
    ** ^If sqlite3_malloc() is unable to obtain sufficient free
    3202
    ** memory, it returns a NULL pointer.  ^If the parameter N to
    3203
    ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
    3204
    ** a NULL pointer.
    3205
    **
    3206
    ** ^The sqlite3_malloc64(N) routine works just like
    3207
    ** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead
    3208
    ** of a signed 32-bit integer.
    3209
    **
    3210
    ** ^Calling sqlite3_free() with a pointer previously returned
    3211
    ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
    3212
    ** that it might be reused.  ^The sqlite3_free() routine is
    3213
    ** a no-op if is called with a NULL pointer.  Passing a NULL pointer
    3214
    ** to sqlite3_free() is harmless.  After being freed, memory
    3215
    ** should neither be read nor written.  Even reading previously freed
    3216
    ** memory might result in a segmentation fault or other severe error.
    3217
    ** Memory corruption, a segmentation fault, or other severe error
    3218
    ** might result if sqlite3_free() is called with a non-NULL pointer that
    3219
    ** was not obtained from sqlite3_malloc() or sqlite3_realloc().
    3220
    **
    3221
    ** ^The sqlite3_realloc(X,N) interface attempts to resize a
    3222
    ** prior memory allocation X to be at least N bytes.
    3223
    ** ^If the X parameter to sqlite3_realloc(X,N)
    3224
    ** is a NULL pointer then its behavior is identical to calling
    3225
    ** sqlite3_malloc(N).
    3226
    ** ^If the N parameter to sqlite3_realloc(X,N) is zero or
    3227
    ** negative then the behavior is exactly the same as calling
    3228
    ** sqlite3_free(X).
    3229
    ** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation
    3230
    ** of at least N bytes in size or NULL if insufficient memory is available.
    3231
    ** ^If M is the size of the prior allocation, then min(N,M) bytes
    3232
    ** of the prior allocation are copied into the beginning of buffer returned
    3233
    ** by sqlite3_realloc(X,N) and the prior allocation is freed.
    3234
    ** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the
    3235
    ** prior allocation is not freed.
    3236
    **
    3237
    ** ^The sqlite3_realloc64(X,N) interfaces works the same as
    3238
    ** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead
    3239
    ** of a 32-bit signed integer.
    3240
    **
    3241
    ** ^If X is a memory allocation previously obtained from sqlite3_malloc(),
    3242
    ** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then
    3243
    ** sqlite3_msize(X) returns the size of that memory allocation in bytes.
    3244
    ** ^The value returned by sqlite3_msize(X) might be larger than the number
    3245
    ** of bytes requested when X was allocated.  ^If X is a NULL pointer then
    3246
    ** sqlite3_msize(X) returns zero.  If X points to something that is not
    3247
    ** the beginning of memory allocation, or if it points to a formerly
    3248
    ** valid memory allocation that has now been freed, then the behavior
    3249
    ** of sqlite3_msize(X) is undefined and possibly harmful.
    3250
    **
    3251
    ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(),
    3252
    ** sqlite3_malloc64(), and sqlite3_realloc64()
    3253
    ** is always aligned to at least an 8 byte boundary, or to a
    3254
    ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
    3255
    ** option is used.
    3256
    **
    3257
    ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
    3258
    ** must be either NULL or else pointers obtained from a prior
    3259
    ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
    3260
    ** not yet been released.
    3261
    **
    3262
    ** The application must not read or write any part of
    3263
    ** a block of memory after it has been released using
    3264
    ** [sqlite3_free()] or [sqlite3_realloc()].
    3265
    */
    3266
    SQLITE_API void *sqlite3_malloc(int);
    3267
    SQLITE_API void *sqlite3_malloc64(sqlite3_uint64);
    3268
    SQLITE_API void *sqlite3_realloc(void*, int);
    3269
    SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64);
    3270
    SQLITE_API void sqlite3_free(void*);
    3271
    SQLITE_API sqlite3_uint64 sqlite3_msize(void*);
    3272
    3273
    /*
    3274
    ** CAPI3REF: Memory Allocator Statistics
    3275
    **
    3276
    ** SQLite provides these two interfaces for reporting on the status
    3277
    ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
    3278
    ** routines, which form the built-in memory allocation subsystem.
    3279
    **
    3280
    ** ^The [sqlite3_memory_used()] routine returns the number of bytes
    3281
    ** of memory currently outstanding (malloced but not freed).
    3282
    ** ^The [sqlite3_memory_highwater()] routine returns the maximum
    3283
    ** value of [sqlite3_memory_used()] since the high-water mark
    3284
    ** was last reset.  ^The values returned by [sqlite3_memory_used()] and
    3285
    ** [sqlite3_memory_highwater()] include any overhead
    3286
    ** added by SQLite in its implementation of [sqlite3_malloc()],
    3287
    ** but not overhead added by the any underlying system library
    3288
    ** routines that [sqlite3_malloc()] may call.
    3289
    **
    3290
    ** ^The memory high-water mark is reset to the current value of
    3291
    ** [sqlite3_memory_used()] if and only if the parameter to
    3292
    ** [sqlite3_memory_highwater()] is true.  ^The value returned
    3293
    ** by [sqlite3_memory_highwater(1)] is the high-water mark
    3294
    ** prior to the reset.
    3295
    */
    3296
    SQLITE_API sqlite3_int64 sqlite3_memory_used(void);
    3297
    SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag);
    3298
    3299
    /*
    3300
    ** CAPI3REF: Pseudo-Random Number Generator
    3301
    **
    3302
    ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
    3303
    ** select random [ROWID | ROWIDs] when inserting new records into a table that
    3304
    ** already uses the largest possible [ROWID].  The PRNG is also used for
    3305
    ** the built-in random() and randomblob() SQL functions.  This interface allows
    3306
    ** applications to access the same PRNG for other purposes.
    3307
    **
    3308
    ** ^A call to this routine stores N bytes of randomness into buffer P.
    3309
    ** ^The P parameter can be a NULL pointer.
    3310
    **
    3311
    ** ^If this routine has not been previously called or if the previous
    3312
    ** call had N less than one or a NULL pointer for P, then the PRNG is
    3313
    ** seeded using randomness obtained from the xRandomness method of
    3314
    ** the default [sqlite3_vfs] object.
    3315
    ** ^If the previous call to this routine had an N of 1 or more and a
    3316
    ** non-NULL P then the pseudo-randomness is generated
    3317
    ** internally and without recourse to the [sqlite3_vfs] xRandomness
    3318
    ** method.
    3319
    */
    3320
    SQLITE_API void sqlite3_randomness(int N, void *P);
    3321
    3322
    /*
    3323
    ** CAPI3REF: Compile-Time Authorization Callbacks
    3324
    ** METHOD: sqlite3
    3325
    ** KEYWORDS: {authorizer callback}
    3326
    **
    3327
    ** ^This routine registers an authorizer callback with a particular
    3328
    ** [database connection], supplied in the first argument.
    3329
    ** ^The authorizer callback is invoked as SQL statements are being compiled
    3330
    ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
    3331
    ** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()],
    3332
    ** and [sqlite3_prepare16_v3()].  ^At various
    3333
    ** points during the compilation process, as logic is being created
    3334
    ** to perform various actions, the authorizer callback is invoked to
    3335
    ** see if those actions are allowed.  ^The authorizer callback should
    3336
    ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
    3337
    ** specific action but allow the SQL statement to continue to be
    3338
    ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
    3339
    ** rejected with an error.  ^If the authorizer callback returns
    3340
    ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
    3341
    ** then the [sqlite3_prepare_v2()] or equivalent call that triggered
    3342
    ** the authorizer will fail with an error message.
    3343
    **
    3344
    ** When the callback returns [SQLITE_OK], that means the operation
    3345
    ** requested is ok.  ^When the callback returns [SQLITE_DENY], the
    3346
    ** [sqlite3_prepare_v2()] or equivalent call that triggered the
    3347
    ** authorizer will fail with an error message explaining that
    3348
    ** access is denied.
    3349
    **
    3350
    ** ^The first parameter to the authorizer callback is a copy of the third
    3351
    ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
    3352
    ** to the callback is an integer [SQLITE_COPY | action code] that specifies
    3353
    ** the particular action to be authorized. ^The third through sixth parameters
    3354
    ** to the callback are either NULL pointers or zero-terminated strings
    3355
    ** that contain additional details about the action to be authorized.
    3356
    ** Applications must always be prepared to encounter a NULL pointer in any
    3357
    ** of the third through the sixth parameters of the authorization callback.
    3358
    **
    3359
    ** ^If the action code is [SQLITE_READ]
    3360
    ** and the callback returns [SQLITE_IGNORE] then the
    3361
    ** [prepared statement] statement is constructed to substitute
    3362
    ** a NULL value in place of the table column that would have
    3363
    ** been read if [SQLITE_OK] had been returned.  The [SQLITE_IGNORE]
    3364
    ** return can be used to deny an untrusted user access to individual
    3365
    ** columns of a table.
    3366
    ** ^When a table is referenced by a [SELECT] but no column values are
    3367
    ** extracted from that table (for example in a query like
    3368
    ** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback
    3369
    ** is invoked once for that table with a column name that is an empty string.
    3370
    ** ^If the action code is [SQLITE_DELETE] and the callback returns
    3371
    ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
    3372
    ** [truncate optimization] is disabled and all rows are deleted individually.
    3373
    **
    3374
    ** An authorizer is used when [sqlite3_prepare | preparing]
    3375
    ** SQL statements from an untrusted source, to ensure that the SQL statements
    3376
    ** do not try to access data they are not allowed to see, or that they do not
    3377
    ** try to execute malicious statements that damage the database.  For
    3378
    ** example, an application may allow a user to enter arbitrary
    3379
    ** SQL queries for evaluation by a database.  But the application does
    3380
    ** not want the user to be able to make arbitrary changes to the
    3381
    ** database.  An authorizer could then be put in place while the
    3382
    ** user-entered SQL is being [sqlite3_prepare | prepared] that
    3383
    ** disallows everything except [SELECT] statements.
    3384
    **
    3385
    ** Applications that need to process SQL from untrusted sources
    3386
    ** might also consider lowering resource limits using [sqlite3_limit()]
    3387
    ** and limiting database size using the [max_page_count] [PRAGMA]
    3388
    ** in addition to using an authorizer.
    3389
    **
    3390
    ** ^(Only a single authorizer can be in place on a database connection
    3391
    ** at a time.  Each call to sqlite3_set_authorizer overrides the
    3392
    ** previous call.)^  ^Disable the authorizer by installing a NULL callback.
    3393
    ** The authorizer is disabled by default.
    3394
    **
    3395
    ** The authorizer callback must not do anything that will modify
    3396
    ** the database connection that invoked the authorizer callback.
    3397
    ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
    3398
    ** database connections for the meaning of "modify" in this paragraph.
    3399
    **
    3400
    ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
    3401
    ** statement might be re-prepared during [sqlite3_step()] due to a
    3402
    ** schema change.  Hence, the application should ensure that the
    3403
    ** correct authorizer callback remains in place during the [sqlite3_step()].
    3404
    **
    3405
    ** ^Note that the authorizer callback is invoked only during
    3406
    ** [sqlite3_prepare()] or its variants.  Authorization is not
    3407
    ** performed during statement evaluation in [sqlite3_step()], unless
    3408
    ** as stated in the previous paragraph, sqlite3_step() invokes
    3409
    ** sqlite3_prepare_v2() to reprepare a statement after a schema change.
    3410
    */
    3411
    SQLITE_API int sqlite3_set_authorizer(
    3412
      sqlite3*,
    3413
      int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
    3414
      void *pUserData
    3415
    );
    3416
    3417
    /*
    3418
    ** CAPI3REF: Authorizer Return Codes
    3419
    **
    3420
    ** The [sqlite3_set_authorizer | authorizer callback function] must
    3421
    ** return either [SQLITE_OK] or one of these two constants in order
    3422
    ** to signal SQLite whether or not the action is permitted.  See the
    3423
    ** [sqlite3_set_authorizer | authorizer documentation] for additional
    3424
    ** information.
    3425
    **
    3426
    ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode]
    3427
    ** returned from the [sqlite3_vtab_on_conflict()] interface.
    3428
    */
    3429
    #define SQLITE_DENY   1   /* Abort the SQL statement with an error */
    3430
    #define SQLITE_IGNORE 2   /* Don't allow access, but don't generate an error */
    3431
    3432
    /*
    3433
    ** CAPI3REF: Authorizer Action Codes
    3434
    **
    3435
    ** The [sqlite3_set_authorizer()] interface registers a callback function
    3436
    ** that is invoked to authorize certain SQL statement actions.  The
    3437
    ** second parameter to the callback is an integer code that specifies
    3438
    ** what action is being authorized.  These are the integer action codes that
    3439
    ** the authorizer callback may be passed.
    3440
    **
    3441
    ** These action code values signify what kind of operation is to be
    3442
    ** authorized.  The 3rd and 4th parameters to the authorization
    3443
    ** callback function will be parameters or NULL depending on which of these
    3444
    ** codes is used as the second parameter.  ^(The 5th parameter to the
    3445
    ** authorizer callback is the name of the database ("main", "temp",
    3446
    ** etc.) if applicable.)^  ^The 6th parameter to the authorizer callback
    3447
    ** is the name of the inner-most trigger or view that is responsible for
    3448
    ** the access attempt or NULL if this access attempt is directly from
    3449
    ** top-level SQL code.
    3450
    */
    3451
    /******************************************* 3rd ************ 4th ***********/
    3452
    #define SQLITE_CREATE_INDEX          1   /* Index Name      Table Name      */
    3453
    #define SQLITE_CREATE_TABLE          2   /* Table Name      NULL            */
    3454
    #define SQLITE_CREATE_TEMP_INDEX     3   /* Index Name      Table Name      */
    3455
    #define SQLITE_CREATE_TEMP_TABLE     4   /* Table Name      NULL            */
    3456
    #define SQLITE_CREATE_TEMP_TRIGGER   5   /* Trigger Name    Table Name      */
    3457
    #define SQLITE_CREATE_TEMP_VIEW      6   /* View Name       NULL            */
    3458
    #define SQLITE_CREATE_TRIGGER        7   /* Trigger Name    Table Name      */
    3459
    #define SQLITE_CREATE_VIEW           8   /* View Name       NULL            */
    3460
    #define SQLITE_DELETE                9   /* Table Name      NULL            */
    3461
    #define SQLITE_DROP_INDEX           10   /* Index Name      Table Name      */
    3462
    #define SQLITE_DROP_TABLE           11   /* Table Name      NULL            */
    3463
    #define SQLITE_DROP_TEMP_INDEX      12   /* Index Name      Table Name      */
    3464
    #define SQLITE_DROP_TEMP_TABLE      13   /* Table Name      NULL            */
    3465
    #define SQLITE_DROP_TEMP_TRIGGER    14   /* Trigger Name    Table Name      */
    3466
    #define SQLITE_DROP_TEMP_VIEW       15   /* View Name       NULL            */
    3467
    #define SQLITE_DROP_TRIGGER         16   /* Trigger Name    Table Name      */
    3468
    #define SQLITE_DROP_VIEW            17   /* View Name       NULL            */
    3469
    #define SQLITE_INSERT               18   /* Table Name      NULL            */
    3470
    #define SQLITE_PRAGMA               19   /* Pragma Name     1st arg or NULL */
    3471
    #define SQLITE_READ                 20   /* Table Name      Column Name     */
    3472
    #define SQLITE_SELECT               21   /* NULL            NULL            */
    3473
    #define SQLITE_TRANSACTION          22   /* Operation       NULL            */
    3474
    #define SQLITE_UPDATE               23   /* Table Name      Column Name     */
    3475
    #define SQLITE_ATTACH               24   /* Filename        NULL            */
    3476
    #define SQLITE_DETACH               25   /* Database Name   NULL            */
    3477
    #define SQLITE_ALTER_TABLE          26   /* Database Name   Table Name      */
    3478
    #define SQLITE_REINDEX              27   /* Index Name      NULL            */
    3479
    #define SQLITE_ANALYZE              28   /* Table Name      NULL            */
    3480
    #define SQLITE_CREATE_VTABLE        29   /* Table Name      Module Name     */
    3481
    #define SQLITE_DROP_VTABLE          30   /* Table Name      Module Name     */
    3482
    #define SQLITE_FUNCTION             31   /* NULL            Function Name   */
    3483
    #define SQLITE_SAVEPOINT            32   /* Operation       Savepoint Name  */
    3484
    #define SQLITE_COPY                  0   /* No longer used */
    3485
    #define SQLITE_RECURSIVE            33   /* NULL            NULL            */
    3486
    3487
    /*
    3488
    ** CAPI3REF: Deprecated Tracing And Profiling Functions
    3489
    ** DEPRECATED
    3490
    **
    3491
    ** These routines are deprecated. Use the [sqlite3_trace_v2()] interface
    3492
    ** instead of the routines described here.
    3493
    **
    3494
    ** These routines register callback functions that can be used for
    3495
    ** tracing and profiling the execution of SQL statements.
    3496
    **
    3497
    ** ^The callback function registered by sqlite3_trace() is invoked at
    3498
    ** various times when an SQL statement is being run by [sqlite3_step()].
    3499
    ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
    3500
    ** SQL statement text as the statement first begins executing.
    3501
    ** ^(Additional sqlite3_trace() callbacks might occur
    3502
    ** as each triggered subprogram is entered.  The callbacks for triggers
    3503
    ** contain a UTF-8 SQL comment that identifies the trigger.)^
    3504
    **
    3505
    ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit
    3506
    ** the length of [bound parameter] expansion in the output of sqlite3_trace().
    3507
    **
    3508
    ** ^The callback function registered by sqlite3_profile() is invoked
    3509
    ** as each SQL statement finishes.  ^The profile callback contains
    3510
    ** the original statement text and an estimate of wall-clock time
    3511
    ** of how long that statement took to run.  ^The profile callback
    3512
    ** time is in units of nanoseconds, however the current implementation
    3513
    ** is only capable of millisecond resolution so the six least significant
    3514
    ** digits in the time are meaningless.  Future versions of SQLite
    3515
    ** might provide greater resolution on the profiler callback.  Invoking
    3516
    ** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the
    3517
    ** profile callback.
    3518
    */
    3519
    SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*,
    3520
       void(*xTrace)(void*,const char*), void*);
    3521
    SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*,
    3522
       void(*xProfile)(void*,const char*,sqlite3_uint64), void*);
    3523
    3524
    /*
    3525
    ** CAPI3REF: SQL Trace Event Codes
    3526
    ** KEYWORDS: SQLITE_TRACE
    3527
    **
    3528
    ** These constants identify classes of events that can be monitored
    3529
    ** using the [sqlite3_trace_v2()] tracing logic.  The M argument
    3530
    ** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of
    3531
    ** the following constants.  ^The first argument to the trace callback
    3532
    ** is one of the following constants.
    3533
    **
    3534
    ** New tracing constants may be added in future releases.
    3535
    **
    3536
    ** ^A trace callback has four arguments: xCallback(T,C,P,X).
    3537
    ** ^The T argument is one of the integer type codes above.
    3538
    ** ^The C argument is a copy of the context pointer passed in as the
    3539
    ** fourth argument to [sqlite3_trace_v2()].
    3540
    ** The P and X arguments are pointers whose meanings depend on T.
    3541
    **
    3542
    ** <dl>
    3543
    ** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt>
    3544
    ** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement
    3545
    ** first begins running and possibly at other times during the
    3546
    ** execution of the prepared statement, such as at the start of each
    3547
    ** trigger subprogram. ^The P argument is a pointer to the
    3548
    ** [prepared statement]. ^The X argument is a pointer to a string which
    3549
    ** is the unexpanded SQL text of the prepared statement or an SQL comment
    3550
    ** that indicates the invocation of a trigger.  ^The callback can compute
    3551
    ** the same text that would have been returned by the legacy [sqlite3_trace()]
    3552
    ** interface by using the X argument when X begins with "--" and invoking
    3553
    ** [sqlite3_expanded_sql(P)] otherwise.
    3554
    **
    3555
    ** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt>
    3556
    ** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same
    3557
    ** information as is provided by the [sqlite3_profile()] callback.
    3558
    ** ^The P argument is a pointer to the [prepared statement] and the
    3559
    ** X argument points to a 64-bit integer which is approximately
    3560
    ** the number of nanoseconds that the prepared statement took to run.
    3561
    ** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes.
    3562
    **
    3563
    ** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt>
    3564
    ** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared
    3565
    ** statement generates a single row of result.
    3566
    ** ^The P argument is a pointer to the [prepared statement] and the
    3567
    ** X argument is unused.
    3568
    **
    3569
    ** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt>
    3570
    ** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database
    3571
    ** connection closes.
    3572
    ** ^The P argument is a pointer to the [database connection] object
    3573
    ** and the X argument is unused.
    3574
    ** </dl>
    3575
    */
    3576
    #define SQLITE_TRACE_STMT       0x01
    3577
    #define SQLITE_TRACE_PROFILE    0x02
    3578
    #define SQLITE_TRACE_ROW        0x04
    3579
    #define SQLITE_TRACE_CLOSE      0x08
    3580
    3581
    /*
    3582
    ** CAPI3REF: SQL Trace Hook
    3583
    ** METHOD: sqlite3
    3584
    **
    3585
    ** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback
    3586
    ** function X against [database connection] D, using property mask M
    3587
    ** and context pointer P.  ^If the X callback is
    3588
    ** NULL or if the M mask is zero, then tracing is disabled.  The
    3589
    ** M argument should be the bitwise OR-ed combination of
    3590
    ** zero or more [SQLITE_TRACE] constants.
    3591
    **
    3592
    ** ^Each call to either sqlite3_trace(D,X,P) or sqlite3_trace_v2(D,M,X,P)
    3593
    ** overrides (cancels) all prior calls to sqlite3_trace(D,X,P) or
    3594
    ** sqlite3_trace_v2(D,M,X,P) for the [database connection] D.  Each
    3595
    ** database connection may have at most one trace callback.
    3596
    **
    3597
    ** ^The X callback is invoked whenever any of the events identified by
    3598
    ** mask M occur.  ^The integer return value from the callback is currently
    3599
    ** ignored, though this may change in future releases.  Callback
    3600
    ** implementations should return zero to ensure future compatibility.
    3601
    **
    3602
    ** ^A trace callback is invoked with four arguments: callback(T,C,P,X).
    3603
    ** ^The T argument is one of the [SQLITE_TRACE]
    3604
    ** constants to indicate why the callback was invoked.
    3605
    ** ^The C argument is a copy of the context pointer.
    3606
    ** The P and X arguments are pointers whose meanings depend on T.
    3607
    **
    3608
    ** The sqlite3_trace_v2() interface is intended to replace the legacy
    3609
    ** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which
    3610
    ** are deprecated.
    3611
    */
    3612
    SQLITE_API int sqlite3_trace_v2(
    3613
      sqlite3*,
    3614
      unsigned uMask,
    3615
      int(*xCallback)(unsigned,void*,void*,void*),
    3616
      void *pCtx
    3617
    );
    3618
    3619
    /*
    3620
    ** CAPI3REF: Query Progress Callbacks
    3621
    ** METHOD: sqlite3
    3622
    **
    3623
    ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
    3624
    ** function X to be invoked periodically during long running calls to
    3625
    ** [sqlite3_step()] and [sqlite3_prepare()] and similar for
    3626
    ** database connection D.  An example use for this
    3627
    ** interface is to keep a GUI updated during a large query.
    3628
    **
    3629
    ** ^The parameter P is passed through as the only parameter to the
    3630
    ** callback function X.  ^The parameter N is the approximate number of
    3631
    ** [virtual machine instructions] that are evaluated between successive
    3632
    ** invocations of the callback X.  ^If N is less than one then the progress
    3633
    ** handler is disabled.
    3634
    **
    3635
    ** ^Only a single progress handler may be defined at one time per
    3636
    ** [database connection]; setting a new progress handler cancels the
    3637
    ** old one.  ^Setting parameter X to NULL disables the progress handler.
    3638
    ** ^The progress handler is also disabled by setting N to a value less
    3639
    ** than 1.
    3640
    **
    3641
    ** ^If the progress callback returns non-zero, the operation is
    3642
    ** interrupted.  This feature can be used to implement a
    3643
    ** "Cancel" button on a GUI progress dialog box.
    3644
    **
    3645
    ** The progress handler callback must not do anything that will modify
    3646
    ** the database connection that invoked the progress handler.
    3647
    ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
    3648
    ** database connections for the meaning of "modify" in this paragraph.
    3649
    **
    3650
    ** The progress handler callback would originally only be invoked from the
    3651
    ** bytecode engine.  It still might be invoked during [sqlite3_prepare()]
    3652
    ** and similar because those routines might force a reparse of the schema
    3653
    ** which involves running the bytecode engine.  However, beginning with
    3654
    ** SQLite version 3.41.0, the progress handler callback might also be
    3655
    ** invoked directly from [sqlite3_prepare()] while analyzing and generating
    3656
    ** code for complex queries.
    3657
    */
    3658
    SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
    3659
    3660
    /*
    3661
    ** CAPI3REF: Opening A New Database Connection
    3662
    ** CONSTRUCTOR: sqlite3
    3663
    **
    3664
    ** ^These routines open an SQLite database file as specified by the
    3665
    ** filename argument. ^The filename argument is interpreted as UTF-8 for
    3666
    ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
    3667
    ** order for sqlite3_open16(). ^(A [database connection] handle is usually
    3668
    ** returned in *ppDb, even if an error occurs.  The only exception is that
    3669
    ** if SQLite is unable to allocate memory to hold the [sqlite3] object,
    3670
    ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
    3671
    ** object.)^ ^(If the database is opened (and/or created) successfully, then
    3672
    ** [SQLITE_OK] is returned.  Otherwise an [error code] is returned.)^ ^The
    3673
    ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
    3674
    ** an English language description of the error following a failure of any
    3675
    ** of the sqlite3_open() routines.
    3676
    **
    3677
    ** ^The default encoding will be UTF-8 for databases created using
    3678
    ** sqlite3_open() or sqlite3_open_v2().  ^The default encoding for databases
    3679
    ** created using sqlite3_open16() will be UTF-16 in the native byte order.
    3680
    **
    3681
    ** Whether or not an error occurs when it is opened, resources
    3682
    ** associated with the [database connection] handle should be released by
    3683
    ** passing it to [sqlite3_close()] when it is no longer required.
    3684
    **
    3685
    ** The sqlite3_open_v2() interface works like sqlite3_open()
    3686
    ** except that it accepts two additional parameters for additional control
    3687
    ** over the new database connection.  ^(The flags parameter to
    3688
    ** sqlite3_open_v2() must include, at a minimum, one of the following
    3689
    ** three flag combinations:)^
    3690
    **
    3691
    ** <dl>
    3692
    ** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
    3693
    ** <dd>The database is opened in read-only mode.  If the database does
    3694
    ** not already exist, an error is returned.</dd>)^
    3695
    **
    3696
    ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
    3697
    ** <dd>The database is opened for reading and writing if possible, or
    3698
    ** reading only if the file is write protected by the operating
    3699
    ** system.  In either case the database must already exist, otherwise
    3700
    ** an error is returned.  For historical reasons, if opening in
    3701
    ** read-write mode fails due to OS-level permissions, an attempt is
    3702
    ** made to open it in read-only mode. [sqlite3_db_readonly()] can be
    3703
    ** used to determine whether the database is actually
    3704
    ** read-write.</dd>)^
    3705
    **
    3706
    ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
    3707
    ** <dd>The database is opened for reading and writing, and is created if
    3708
    ** it does not already exist. This is the behavior that is always used for
    3709
    ** sqlite3_open() and sqlite3_open16().</dd>)^
    3710
    ** </dl>
    3711
    **
    3712
    ** In addition to the required flags, the following optional flags are
    3713
    ** also supported:
    3714
    **
    3715
    ** <dl>
    3716
    ** ^(<dt>[SQLITE_OPEN_URI]</dt>
    3717
    ** <dd>The filename can be interpreted as a URI if this flag is set.</dd>)^
    3718
    **
    3719
    ** ^(<dt>[SQLITE_OPEN_MEMORY]</dt>
    3720
    ** <dd>The database will be opened as an in-memory database.  The database
    3721
    ** is named by the "filename" argument for the purposes of cache-sharing,
    3722
    ** if shared cache mode is enabled, but the "filename" is otherwise ignored.
    3723
    ** </dd>)^
    3724
    **
    3725
    ** ^(<dt>[SQLITE_OPEN_NOMUTEX]</dt>
    3726
    ** <dd>The new database connection will use the "multi-thread"
    3727
    ** [threading mode].)^  This means that separate threads are allowed
    3728
    ** to use SQLite at the same time, as long as each thread is using
    3729
    ** a different [database connection].
    3730
    **
    3731
    ** ^(<dt>[SQLITE_OPEN_FULLMUTEX]</dt>
    3732
    ** <dd>The new database connection will use the "serialized"
    3733
    ** [threading mode].)^  This means the multiple threads can safely
    3734
    ** attempt to use the same database connection at the same time.
    3735
    ** (Mutexes will block any actual concurrency, but in this mode
    3736
    ** there is no harm in trying.)
    3737
    **
    3738
    ** ^(<dt>[SQLITE_OPEN_SHAREDCACHE]</dt>
    3739
    ** <dd>The database is opened [shared cache] enabled, overriding
    3740
    ** the default shared cache setting provided by
    3741
    ** [sqlite3_enable_shared_cache()].)^
    3742
    ** The [use of shared cache mode is discouraged] and hence shared cache
    3743
    ** capabilities may be omitted from many builds of SQLite.  In such cases,
    3744
    ** this option is a no-op.
    3745
    **
    3746
    ** ^(<dt>[SQLITE_OPEN_PRIVATECACHE]</dt>
    3747
    ** <dd>The database is opened [shared cache] disabled, overriding
    3748
    ** the default shared cache setting provided by
    3749
    ** [sqlite3_enable_shared_cache()].)^
    3750
    **
    3751
    ** [[OPEN_EXRESCODE]] ^(<dt>[SQLITE_OPEN_EXRESCODE]</dt>
    3752
    ** <dd>The database connection comes up in "extended result code mode".
    3753
    ** In other words, the database behaves as if
    3754
    ** [sqlite3_extended_result_codes(db,1)] were called on the database
    3755
    ** connection as soon as the connection is created. In addition to setting
    3756
    ** the extended result code mode, this flag also causes [sqlite3_open_v2()]
    3757
    ** to return an extended result code.</dd>
    3758
    **
    3759
    ** [[OPEN_NOFOLLOW]] ^(<dt>[SQLITE_OPEN_NOFOLLOW]</dt>
    3760
    ** <dd>The database filename is not allowed to contain a symbolic link</dd>
    3761
    ** </dl>)^
    3762
    **
    3763
    ** If the 3rd parameter to sqlite3_open_v2() is not one of the
    3764
    ** required combinations shown above optionally combined with other
    3765
    ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits]
    3766
    ** then the behavior is undefined.  Historic versions of SQLite
    3767
    ** have silently ignored surplus bits in the flags parameter to
    3768
    ** sqlite3_open_v2(), however that behavior might not be carried through
    3769
    ** into future versions of SQLite and so applications should not rely
    3770
    ** upon it.  Note in particular that the SQLITE_OPEN_EXCLUSIVE flag is a no-op
    3771
    ** for sqlite3_open_v2().  The SQLITE_OPEN_EXCLUSIVE does *not* cause
    3772
    ** the open to fail if the database already exists.  The SQLITE_OPEN_EXCLUSIVE
    3773
    ** flag is intended for use by the [sqlite3_vfs|VFS interface] only, and not
    3774
    ** by sqlite3_open_v2().
    3775
    **
    3776
    ** ^The fourth parameter to sqlite3_open_v2() is the name of the
    3777
    ** [sqlite3_vfs] object that defines the operating system interface that
    3778
    ** the new database connection should use.  ^If the fourth parameter is
    3779
    ** a NULL pointer then the default [sqlite3_vfs] object is used.
    3780
    **
    3781
    ** ^If the filename is ":memory:", then a private, temporary in-memory database
    3782
    ** is created for the connection.  ^This in-memory database will vanish when
    3783
    ** the database connection is closed.  Future versions of SQLite might
    3784
    ** make use of additional special filenames that begin with the ":" character.
    3785
    ** It is recommended that when a database filename actually does begin with
    3786
    ** a ":" character you should prefix the filename with a pathname such as
    3787
    ** "./" to avoid ambiguity.
    3788
    **
    3789
    ** ^If the filename is an empty string, then a private, temporary
    3790
    ** on-disk database will be created.  ^This private database will be
    3791
    ** automatically deleted as soon as the database connection is closed.
    3792
    **
    3793
    ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3>
    3794
    **
    3795
    ** ^If [URI filename] interpretation is enabled, and the filename argument
    3796
    ** begins with "file:", then the filename is interpreted as a URI. ^URI
    3797
    ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is
    3798
    ** set in the third argument to sqlite3_open_v2(), or if it has
    3799
    ** been enabled globally using the [SQLITE_CONFIG_URI] option with the
    3800
    ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option.
    3801
    ** URI filename interpretation is turned off
    3802
    ** by default, but future releases of SQLite might enable URI filename
    3803
    ** interpretation by default.  See "[URI filenames]" for additional
    3804
    ** information.
    3805
    **
    3806
    ** URI filenames are parsed according to RFC 3986. ^If the URI contains an
    3807
    ** authority, then it must be either an empty string or the string
    3808
    ** "localhost". ^If the authority is not an empty string or "localhost", an
    3809
    ** error is returned to the caller. ^The fragment component of a URI, if
    3810
    ** present, is ignored.
    3811
    **
    3812
    ** ^SQLite uses the path component of the URI as the name of the disk file
    3813
    ** which contains the database. ^If the path begins with a '/' character,
    3814
    ** then it is interpreted as an absolute path. ^If the path does not begin
    3815
    ** with a '/' (meaning that the authority section is omitted from the URI)
    3816
    ** then the path is interpreted as a relative path.
    3817
    ** ^(On windows, the first component of an absolute path
    3818
    ** is a drive specification (e.g. "C:").)^
    3819
    **
    3820
    ** [[core URI query parameters]]
    3821
    ** The query component of a URI may contain parameters that are interpreted
    3822
    ** either by SQLite itself, or by a [VFS | custom VFS implementation].
    3823
    ** SQLite and its built-in [VFSes] interpret the
    3824
    ** following query parameters:
    3825
    **
    3826
    ** <ul>
    3827
    **   <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
    3828
    **     a VFS object that provides the operating system interface that should
    3829
    **     be used to access the database file on disk. ^If this option is set to
    3830
    **     an empty string the default VFS object is used. ^Specifying an unknown
    3831
    **     VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is
    3832
    **     present, then the VFS specified by the option takes precedence over
    3833
    **     the value passed as the fourth parameter to sqlite3_open_v2().
    3834
    **
    3835
    **   <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw",
    3836
    **     "rwc", or "memory". Attempting to set it to any other value is
    3837
    **     an error)^.
    3838
    **     ^If "ro" is specified, then the database is opened for read-only
    3839
    **     access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the
    3840
    **     third argument to sqlite3_open_v2(). ^If the mode option is set to
    3841
    **     "rw", then the database is opened for read-write (but not create)
    3842
    **     access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had
    3843
    **     been set. ^Value "rwc" is equivalent to setting both
    3844
    **     SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE.  ^If the mode option is
    3845
    **     set to "memory" then a pure [in-memory database] that never reads
    3846
    **     or writes from disk is used. ^It is an error to specify a value for
    3847
    **     the mode parameter that is less restrictive than that specified by
    3848
    **     the flags passed in the third parameter to sqlite3_open_v2().
    3849
    **
    3850
    **   <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or
    3851
    **     "private". ^Setting it to "shared" is equivalent to setting the
    3852
    **     SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to
    3853
    **     sqlite3_open_v2(). ^Setting the cache parameter to "private" is
    3854
    **     equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
    3855
    **     ^If sqlite3_open_v2() is used and the "cache" parameter is present in
    3856
    **     a URI filename, its value overrides any behavior requested by setting
    3857
    **     SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
    3858
    **
    3859
    **  <li> <b>psow</b>: ^The psow parameter indicates whether or not the
    3860
    **     [powersafe overwrite] property does or does not apply to the
    3861
    **     storage media on which the database file resides.
    3862
    **
    3863
    **  <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter
    3864
    **     which if set disables file locking in rollback journal modes.  This
    3865
    **     is useful for accessing a database on a filesystem that does not
    3866
    **     support locking.  Caution:  Database corruption might result if two
    3867
    **     or more processes write to the same database and any one of those
    3868
    **     processes uses nolock=1.
    3869
    **
    3870
    **  <li> <b>immutable</b>: ^The immutable parameter is a boolean query
    3871
    **     parameter that indicates that the database file is stored on
    3872
    **     read-only media.  ^When immutable is set, SQLite assumes that the
    3873
    **     database file cannot be changed, even by a process with higher
    3874
    **     privilege, and so the database is opened read-only and all locking
    3875
    **     and change detection is disabled.  Caution: Setting the immutable
    3876
    **     property on a database file that does in fact change can result
    3877
    **     in incorrect query results and/or [SQLITE_CORRUPT] errors.
    3878
    **     See also: [SQLITE_IOCAP_IMMUTABLE].
    3879
    **
    3880
    ** </ul>
    3881
    **
    3882
    ** ^Specifying an unknown parameter in the query component of a URI is not an
    3883
    ** error.  Future versions of SQLite might understand additional query
    3884
    ** parameters.  See "[query parameters with special meaning to SQLite]" for
    3885
    ** additional information.
    3886
    **
    3887
    ** [[URI filename examples]] <h3>URI filename examples</h3>
    3888
    **
    3889
    ** <table border="1" align=center cellpadding=5>
    3890
    ** <tr><th> URI filenames <th> Results
    3891
    ** <tr><td> file:data.db <td>
    3892
    **          Open the file "data.db" in the current directory.
    3893
    ** <tr><td> file:/home/fred/data.db<br>
    3894
    **          file:///home/fred/data.db <br>
    3895
    **          file://localhost/home/fred/data.db <br> <td>
    3896
    **          Open the database file "/home/fred/data.db".
    3897
    ** <tr><td> file://darkstar/home/fred/data.db <td>
    3898
    **          An error. "darkstar" is not a recognized authority.
    3899
    ** <tr><td style="white-space:nowrap">
    3900
    **          file:///C:/Documents%20and%20Settings/fred/Desktop/data.db
    3901
    **     <td> Windows only: Open the file "data.db" on fred's desktop on drive
    3902
    **          C:. Note that the %20 escaping in this example is not strictly
    3903
    **          necessary - space characters can be used literally
    3904
    **          in URI filenames.
    3905
    ** <tr><td> file:data.db?mode=ro&cache=private <td>
    3906
    **          Open file "data.db" in the current directory for read-only access.
    3907
    **          Regardless of whether or not shared-cache mode is enabled by
    3908
    **          default, use a private cache.
    3909
    ** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td>
    3910
    **          Open file "/home/fred/data.db". Use the special VFS "unix-dotfile"
    3911
    **          that uses dot-files in place of posix advisory locking.
    3912
    ** <tr><td> file:data.db?mode=readonly <td>
    3913
    **          An error. "readonly" is not a valid option for the "mode" parameter.
    3914
    **          Use "ro" instead:  "file:data.db?mode=ro".
    3915
    ** </table>
    3916
    **
    3917
    ** ^URI hexadecimal escape sequences (%HH) are supported within the path and
    3918
    ** query components of a URI. A hexadecimal escape sequence consists of a
    3919
    ** percent sign - "%" - followed by exactly two hexadecimal digits
    3920
    ** specifying an octet value. ^Before the path or query components of a
    3921
    ** URI filename are interpreted, they are encoded using UTF-8 and all
    3922
    ** hexadecimal escape sequences replaced by a single byte containing the
    3923
    ** corresponding octet. If this process generates an invalid UTF-8 encoding,
    3924
    ** the results are undefined.
    3925
    **
    3926
    ** <b>Note to Windows users:</b>  The encoding used for the filename argument
    3927
    ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
    3928
    ** codepage is currently defined.  Filenames containing international
    3929
    ** characters must be converted to UTF-8 prior to passing them into
    3930
    ** sqlite3_open() or sqlite3_open_v2().
    3931
    **
    3932
    ** <b>Note to Windows Runtime users:</b>  The temporary directory must be set
    3933
    ** prior to calling sqlite3_open() or sqlite3_open_v2().  Otherwise, various
    3934
    ** features that require the use of temporary files may fail.
    3935
    **
    3936
    ** See also: [sqlite3_temp_directory]
    3937
    */
    3938
    SQLITE_API int sqlite3_open(
    3939
      const char *filename,   /* Database filename (UTF-8) */
    3940
      sqlite3 **ppDb          /* OUT: SQLite db handle */
    3941
    );
    3942
    SQLITE_API int sqlite3_open16(
    3943
      const void *filename,   /* Database filename (UTF-16) */
    3944
      sqlite3 **ppDb          /* OUT: SQLite db handle */
    3945
    );
    3946
    SQLITE_API int sqlite3_open_v2(
    3947
      const char *filename,   /* Database filename (UTF-8) */
    3948
      sqlite3 **ppDb,         /* OUT: SQLite db handle */
    3949
      int flags,              /* Flags */
    3950
      const char *zVfs        /* Name of VFS module to use */
    3951
    );
    3952
    3953
    /*
    3954
    ** CAPI3REF: Obtain Values For URI Parameters
    3955
    **
    3956
    ** These are utility routines, useful to [VFS|custom VFS implementations],
    3957
    ** that check if a database file was a URI that contained a specific query
    3958
    ** parameter, and if so obtains the value of that query parameter.
    3959
    **
    3960
    ** The first parameter to these interfaces (hereafter referred to
    3961
    ** as F) must be one of:
    3962
    ** <ul>
    3963
    ** <li> A database filename pointer created by the SQLite core and
    3964
    ** passed into the xOpen() method of a VFS implementation, or
    3965
    ** <li> A filename obtained from [sqlite3_db_filename()], or
    3966
    ** <li> A new filename constructed using [sqlite3_create_filename()].
    3967
    ** </ul>
    3968
    ** If the F parameter is not one of the above, then the behavior is
    3969
    ** undefined and probably undesirable.  Older versions of SQLite were
    3970
    ** more tolerant of invalid F parameters than newer versions.
    3971
    **
    3972
    ** If F is a suitable filename (as described in the previous paragraph)
    3973
    ** and if P is the name of the query parameter, then
    3974
    ** sqlite3_uri_parameter(F,P) returns the value of the P
    3975
    ** parameter if it exists or a NULL pointer if P does not appear as a
    3976
    ** query parameter on F.  If P is a query parameter of F and it
    3977
    ** has no explicit value, then sqlite3_uri_parameter(F,P) returns
    3978
    ** a pointer to an empty string.
    3979
    **
    3980
    ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean
    3981
    ** parameter and returns true (1) or false (0) according to the value
    3982
    ** of P.  The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the
    3983
    ** value of query parameter P is one of "yes", "true", or "on" in any
    3984
    ** case or if the value begins with a non-zero number.  The
    3985
    ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of
    3986
    ** query parameter P is one of "no", "false", or "off" in any case or
    3987
    ** if the value begins with a numeric zero.  If P is not a query
    3988
    ** parameter on F or if the value of P does not match any of the
    3989
    ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0).
    3990
    **
    3991
    ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a
    3992
    ** 64-bit signed integer and returns that integer, or D if P does not
    3993
    ** exist.  If the value of P is something other than an integer, then
    3994
    ** zero is returned.
    3995
    **
    3996
    ** The sqlite3_uri_key(F,N) returns a pointer to the name (not
    3997
    ** the value) of the N-th query parameter for filename F, or a NULL
    3998
    ** pointer if N is less than zero or greater than the number of query
    3999
    ** parameters minus 1.  The N value is zero-based so N should be 0 to obtain
    4000
    ** the name of the first query parameter, 1 for the second parameter, and
    4001
    ** so forth.
    4002
    **
    4003
    ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and
    4004
    ** sqlite3_uri_boolean(F,P,B) returns B.  If F is not a NULL pointer and
    4005
    ** is not a database file pathname pointer that the SQLite core passed
    4006
    ** into the xOpen VFS method, then the behavior of this routine is undefined
    4007
    ** and probably undesirable.
    4008
    **
    4009
    ** Beginning with SQLite [version 3.31.0] ([dateof:3.31.0]) the input F
    4010
    ** parameter can also be the name of a rollback journal file or WAL file
    4011
    ** in addition to the main database file.  Prior to version 3.31.0, these
    4012
    ** routines would only work if F was the name of the main database file.
    4013
    ** When the F parameter is the name of the rollback journal or WAL file,
    4014
    ** it has access to all the same query parameters as were found on the
    4015
    ** main database file.
    4016
    **
    4017
    ** See the [URI filename] documentation for additional information.
    4018
    */
    4019
    SQLITE_API const char *sqlite3_uri_parameter(sqlite3_filename z, const char *zParam);
    4020
    SQLITE_API int sqlite3_uri_boolean(sqlite3_filename z, const char *zParam, int bDefault);
    4021
    SQLITE_API sqlite3_int64 sqlite3_uri_int64(sqlite3_filename, const char*, sqlite3_int64);
    4022
    SQLITE_API const char *sqlite3_uri_key(sqlite3_filename z, int N);
    4023
    4024
    /*
    4025
    ** CAPI3REF:  Translate filenames
    4026
    **
    4027
    ** These routines are available to [VFS|custom VFS implementations] for
    4028
    ** translating filenames between the main database file, the journal file,
    4029
    ** and the WAL file.
    4030
    **
    4031
    ** If F is the name of an sqlite database file, journal file, or WAL file
    4032
    ** passed by the SQLite core into the VFS, then sqlite3_filename_database(F)
    4033
    ** returns the name of the corresponding database file.
    4034
    **
    4035
    ** If F is the name of an sqlite database file, journal file, or WAL file
    4036
    ** passed by the SQLite core into the VFS, or if F is a database filename
    4037
    ** obtained from [sqlite3_db_filename()], then sqlite3_filename_journal(F)
    4038
    ** returns the name of the corresponding rollback journal file.
    4039
    **
    4040
    ** If F is the name of an sqlite database file, journal file, or WAL file
    4041
    ** that was passed by the SQLite core into the VFS, or if F is a database
    4042
    ** filename obtained from [sqlite3_db_filename()], then
    4043
    ** sqlite3_filename_wal(F) returns the name of the corresponding
    4044
    ** WAL file.
    4045
    **
    4046
    ** In all of the above, if F is not the name of a database, journal or WAL
    4047
    ** filename passed into the VFS from the SQLite core and F is not the
    4048
    ** return value from [sqlite3_db_filename()], then the result is
    4049
    ** undefined and is likely a memory access violation.
    4050
    */
    4051
    SQLITE_API const char *sqlite3_filename_database(sqlite3_filename);
    4052
    SQLITE_API const char *sqlite3_filename_journal(sqlite3_filename);
    4053
    SQLITE_API const char *sqlite3_filename_wal(sqlite3_filename);
    4054
    4055
    /*
    4056
    ** CAPI3REF:  Database File Corresponding To A Journal
    4057
    **
    4058
    ** ^If X is the name of a rollback or WAL-mode journal file that is
    4059
    ** passed into the xOpen method of [sqlite3_vfs], then
    4060
    ** sqlite3_database_file_object(X) returns a pointer to the [sqlite3_file]
    4061
    ** object that represents the main database file.
    4062
    **
    4063
    ** This routine is intended for use in custom [VFS] implementations
    4064
    ** only.  It is not a general-purpose interface.
    4065
    ** The argument sqlite3_file_object(X) must be a filename pointer that
    4066
    ** has been passed into [sqlite3_vfs].xOpen method where the
    4067
    ** flags parameter to xOpen contains one of the bits
    4068
    ** [SQLITE_OPEN_MAIN_JOURNAL] or [SQLITE_OPEN_WAL].  Any other use
    4069
    ** of this routine results in undefined and probably undesirable
    4070
    ** behavior.
    4071
    */
    4072
    SQLITE_API sqlite3_file *sqlite3_database_file_object(const char*);
    4073
    4074
    /*
    4075
    ** CAPI3REF: Create and Destroy VFS Filenames
    4076
    **
    4077
    ** These interfaces are provided for use by [VFS shim] implementations and
    4078
    ** are not useful outside of that context.
    4079
    **
    4080
    ** The sqlite3_create_filename(D,J,W,N,P) allocates memory to hold a version of
    4081
    ** database filename D with corresponding journal file J and WAL file W and
    4082
    ** an array P of N URI Key/Value pairs.  The result from
    4083
    ** sqlite3_create_filename(D,J,W,N,P) is a pointer to a database filename that
    4084
    ** is safe to pass to routines like:
    4085
    ** <ul>
    4086
    ** <li> [sqlite3_uri_parameter()],
    4087
    ** <li> [sqlite3_uri_boolean()],
    4088
    ** <li> [sqlite3_uri_int64()],
    4089
    ** <li> [sqlite3_uri_key()],
    4090
    ** <li> [sqlite3_filename_database()],
    4091
    ** <li> [sqlite3_filename_journal()], or
    4092
    ** <li> [sqlite3_filename_wal()].
    4093
    ** </ul>
    4094
    ** If a memory allocation error occurs, sqlite3_create_filename() might
    4095
    ** return a NULL pointer.  The memory obtained from sqlite3_create_filename(X)
    4096
    ** must be released by a corresponding call to sqlite3_free_filename(Y).
    4097
    **
    4098
    ** The P parameter in sqlite3_create_filename(D,J,W,N,P) should be an array
    4099
    ** of 2*N pointers to strings.  Each pair of pointers in this array corresponds
    4100
    ** to a key and value for a query parameter.  The P parameter may be a NULL
    4101
    ** pointer if N is zero.  None of the 2*N pointers in the P array may be
    4102
    ** NULL pointers and key pointers should not be empty strings.
    4103
    ** None of the D, J, or W parameters to sqlite3_create_filename(D,J,W,N,P) may
    4104
    ** be NULL pointers, though they can be empty strings.
    4105
    **
    4106
    ** The sqlite3_free_filename(Y) routine releases a memory allocation
    4107
    ** previously obtained from sqlite3_create_filename().  Invoking
    4108
    ** sqlite3_free_filename(Y) where Y is a NULL pointer is a harmless no-op.
    4109
    **
    4110
    ** If the Y parameter to sqlite3_free_filename(Y) is anything other
    4111
    ** than a NULL pointer or a pointer previously acquired from
    4112
    ** sqlite3_create_filename(), then bad things such as heap
    4113
    ** corruption or segfaults may occur. The value Y should not be
    4114
    ** used again after sqlite3_free_filename(Y) has been called.  This means
    4115
    ** that if the [sqlite3_vfs.xOpen()] method of a VFS has been called using Y,
    4116
    ** then the corresponding [sqlite3_module.xClose() method should also be
    4117
    ** invoked prior to calling sqlite3_free_filename(Y).
    4118
    */
    4119
    SQLITE_API sqlite3_filename sqlite3_create_filename(
    4120
      const char *zDatabase,
    4121
      const char *zJournal,
    4122
      const char *zWal,
    4123
      int nParam,
    4124
      const char **azParam
    4125
    );
    4126
    SQLITE_API void sqlite3_free_filename(sqlite3_filename);
    4127
    4128
    /*
    4129
    ** CAPI3REF: Error Codes And Messages
    4130
    ** METHOD: sqlite3
    4131
    **
    4132
    ** ^If the most recent sqlite3_* API call associated with
    4133
    ** [database connection] D failed, then the sqlite3_errcode(D) interface
    4134
    ** returns the numeric [result code] or [extended result code] for that
    4135
    ** API call.
    4136
    ** ^The sqlite3_extended_errcode()
    4137
    ** interface is the same except that it always returns the
    4138
    ** [extended result code] even when extended result codes are
    4139
    ** disabled.
    4140
    **
    4141
    ** The values returned by sqlite3_errcode() and/or
    4142
    ** sqlite3_extended_errcode() might change with each API call.
    4143
    ** Except, there are some interfaces that are guaranteed to never
    4144
    ** change the value of the error code.  The error-code preserving
    4145
    ** interfaces include the following:
    4146
    **
    4147
    ** <ul>
    4148
    ** <li> sqlite3_errcode()
    4149
    ** <li> sqlite3_extended_errcode()
    4150
    ** <li> sqlite3_errmsg()
    4151
    ** <li> sqlite3_errmsg16()
    4152
    ** <li> sqlite3_error_offset()
    4153
    ** </ul>
    4154
    **
    4155
    ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
    4156
    ** text that describes the error, as either UTF-8 or UTF-16 respectively,
    4157
    ** or NULL if no error message is available.
    4158
    ** (See how SQLite handles [invalid UTF] for exceptions to this rule.)
    4159
    ** ^(Memory to hold the error message string is managed internally.
    4160
    ** The application does not need to worry about freeing the result.
    4161
    ** However, the error string might be overwritten or deallocated by
    4162
    ** subsequent calls to other SQLite interface functions.)^
    4163
    **
    4164
    ** ^The sqlite3_errstr(E) interface returns the English-language text
    4165
    ** that describes the [result code] E, as UTF-8, or NULL if E is not an
    4166
    ** result code for which a text error message is available.
    4167
    ** ^(Memory to hold the error message string is managed internally
    4168
    ** and must not be freed by the application)^.
    4169
    **
    4170
    ** ^If the most recent error references a specific token in the input
    4171
    ** SQL, the sqlite3_error_offset() interface returns the byte offset
    4172
    ** of the start of that token.  ^The byte offset returned by
    4173
    ** sqlite3_error_offset() assumes that the input SQL is UTF8.
    4174
    ** ^If the most recent error does not reference a specific token in the input
    4175
    ** SQL, then the sqlite3_error_offset() function returns -1.
    4176
    **
    4177
    ** When the serialized [threading mode] is in use, it might be the
    4178
    ** case that a second error occurs on a separate thread in between
    4179
    ** the time of the first error and the call to these interfaces.
    4180
    ** When that happens, the second error will be reported since these
    4181
    ** interfaces always report the most recent result.  To avoid
    4182
    ** this, each thread can obtain exclusive use of the [database connection] D
    4183
    ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
    4184
    ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
    4185
    ** all calls to the interfaces listed here are completed.
    4186
    **
    4187
    ** If an interface fails with SQLITE_MISUSE, that means the interface
    4188
    ** was invoked incorrectly by the application.  In that case, the
    4189
    ** error code and message may or may not be set.
    4190
    */
    4191
    SQLITE_API int sqlite3_errcode(sqlite3 *db);
    4192
    SQLITE_API int sqlite3_extended_errcode(sqlite3 *db);
    4193
    SQLITE_API const char *sqlite3_errmsg(sqlite3*);
    4194
    SQLITE_API const void *sqlite3_errmsg16(sqlite3*);
    4195
    SQLITE_API const char *sqlite3_errstr(int);
    4196
    SQLITE_API int sqlite3_error_offset(sqlite3 *db);
    4197
    4198
    /*
    4199
    ** CAPI3REF: Prepared Statement Object
    4200
    ** KEYWORDS: {prepared statement} {prepared statements}
    4201
    **
    4202
    ** An instance of this object represents a single SQL statement that
    4203
    ** has been compiled into binary form and is ready to be evaluated.
    4204
    **
    4205
    ** Think of each SQL statement as a separate computer program.  The
    4206
    ** original SQL text is source code.  A prepared statement object
    4207
    ** is the compiled object code.  All SQL must be converted into a
    4208
    ** prepared statement before it can be run.
    4209
    **
    4210
    ** The life-cycle of a prepared statement object usually goes like this:
    4211
    **
    4212
    ** <ol>
    4213
    ** <li> Create the prepared statement object using [sqlite3_prepare_v2()].
    4214
    ** <li> Bind values to [parameters] using the sqlite3_bind_*()
    4215
    **      interfaces.
    4216
    ** <li> Run the SQL by calling [sqlite3_step()] one or more times.
    4217
    ** <li> Reset the prepared statement using [sqlite3_reset()] then go back
    4218
    **      to step 2.  Do this zero or more times.
    4219
    ** <li> Destroy the object using [sqlite3_finalize()].
    4220
    ** </ol>
    4221
    */
    4222
    typedef struct sqlite3_stmt sqlite3_stmt;
    4223
    4224
    /*
    4225
    ** CAPI3REF: Run-time Limits
    4226
    ** METHOD: sqlite3
    4227
    **
    4228
    ** ^(This interface allows the size of various constructs to be limited
    4229
    ** on a connection by connection basis.  The first parameter is the
    4230
    ** [database connection] whose limit is to be set or queried.  The
    4231
    ** second parameter is one of the [limit categories] that define a
    4232
    ** class of constructs to be size limited.  The third parameter is the
    4233
    ** new limit for that construct.)^
    4234
    **
    4235
    ** ^If the new limit is a negative number, the limit is unchanged.
    4236
    ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a
    4237
    ** [limits | hard upper bound]
    4238
    ** set at compile-time by a C preprocessor macro called
    4239
    ** [limits | SQLITE_MAX_<i>NAME</i>].
    4240
    ** (The "_LIMIT_" in the name is changed to "_MAX_".))^
    4241
    ** ^Attempts to increase a limit above its hard upper bound are
    4242
    ** silently truncated to the hard upper bound.
    4243
    **
    4244
    ** ^Regardless of whether or not the limit was changed, the
    4245
    ** [sqlite3_limit()] interface returns the prior value of the limit.
    4246
    ** ^Hence, to find the current value of a limit without changing it,
    4247
    ** simply invoke this interface with the third parameter set to -1.
    4248
    **
    4249
    ** Run-time limits are intended for use in applications that manage
    4250
    ** both their own internal database and also databases that are controlled
    4251
    ** by untrusted external sources.  An example application might be a
    4252
    ** web browser that has its own databases for storing history and
    4253
    ** separate databases controlled by JavaScript applications downloaded
    4254
    ** off the Internet.  The internal databases can be given the
    4255
    ** large, default limits.  Databases managed by external sources can
    4256
    ** be given much smaller limits designed to prevent a denial of service
    4257
    ** attack.  Developers might also want to use the [sqlite3_set_authorizer()]
    4258
    ** interface to further control untrusted SQL.  The size of the database
    4259
    ** created by an untrusted script can be contained using the
    4260
    ** [max_page_count] [PRAGMA].
    4261
    **
    4262
    ** New run-time limit categories may be added in future releases.
    4263
    */
    4264
    SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
    4265
    4266
    /*
    4267
    ** CAPI3REF: Run-Time Limit Categories
    4268
    ** KEYWORDS: {limit category} {*limit categories}
    4269
    **
    4270
    ** These constants define various performance limits
    4271
    ** that can be lowered at run-time using [sqlite3_limit()].
    4272
    ** The synopsis of the meanings of the various limits is shown below.
    4273
    ** Additional information is available at [limits | Limits in SQLite].
    4274
    **
    4275
    ** <dl>
    4276
    ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt>
    4277
    ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
    4278
    **
    4279
    ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
    4280
    ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^
    4281
    **
    4282
    ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt>
    4283
    ** <dd>The maximum number of columns in a table definition or in the
    4284
    ** result set of a [SELECT] or the maximum number of columns in an index
    4285
    ** or in an ORDER BY or GROUP BY clause.</dd>)^
    4286
    **
    4287
    ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
    4288
    ** <dd>The maximum depth of the parse tree on any expression.</dd>)^
    4289
    **
    4290
    ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
    4291
    ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
    4292
    **
    4293
    ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt>
    4294
    ** <dd>The maximum number of instructions in a virtual machine program
    4295
    ** used to implement an SQL statement.  If [sqlite3_prepare_v2()] or
    4296
    ** the equivalent tries to allocate space for more than this many opcodes
    4297
    ** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^
    4298
    **
    4299
    ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
    4300
    ** <dd>The maximum number of arguments on a function.</dd>)^
    4301
    **
    4302
    ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt>
    4303
    ** <dd>The maximum number of [ATTACH | attached databases].)^</dd>
    4304
    **
    4305
    ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]]
    4306
    ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
    4307
    ** <dd>The maximum length of the pattern argument to the [LIKE] or
    4308
    ** [GLOB] operators.</dd>)^
    4309
    **
    4310
    ** [[SQLITE_LIMIT_VARIABLE_NUMBER]]
    4311
    ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
    4312
    ** <dd>The maximum index number of any [parameter] in an SQL statement.)^
    4313
    **
    4314
    ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
    4315
    ** <dd>The maximum depth of recursion for triggers.</dd>)^
    4316
    **
    4317
    ** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt>
    4318
    ** <dd>The maximum number of auxiliary worker threads that a single
    4319
    ** [prepared statement] may start.</dd>)^
    4320
    ** </dl>
    4321
    */
    4322
    4
    #define SQLITE_LIMIT_LENGTH                    0
    4323
    #define SQLITE_LIMIT_SQL_LENGTH                1
    4324
    #define SQLITE_LIMIT_COLUMN                    2
    4325
    #define SQLITE_LIMIT_EXPR_DEPTH                3
    4326
    #define SQLITE_LIMIT_COMPOUND_SELECT           4
    4327
    #define SQLITE_LIMIT_VDBE_OP                   5
    4328
    #define SQLITE_LIMIT_FUNCTION_ARG              6
    4329
    #define SQLITE_LIMIT_ATTACHED                  7
    4330
    #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH       8
    4331
    #define SQLITE_LIMIT_VARIABLE_NUMBER           9
    4332
    #define SQLITE_LIMIT_TRIGGER_DEPTH            10
    4333
    #define SQLITE_LIMIT_WORKER_THREADS           11
    4334
    4335
    /*
    4336
    ** CAPI3REF: Prepare Flags
    4337
    **
    4338
    ** These constants define various flags that can be passed into
    4339
    ** "prepFlags" parameter of the [sqlite3_prepare_v3()] and
    4340
    ** [sqlite3_prepare16_v3()] interfaces.
    4341
    **
    4342
    ** New flags may be added in future releases of SQLite.
    4343
    **
    4344
    ** <dl>
    4345
    ** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt>
    4346
    ** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner
    4347
    ** that the prepared statement will be retained for a long time and
    4348
    ** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()]
    4349
    ** and [sqlite3_prepare16_v3()] assume that the prepared statement will
    4350
    ** be used just once or at most a few times and then destroyed using
    4351
    ** [sqlite3_finalize()] relatively soon. The current implementation acts
    4352
    ** on this hint by avoiding the use of [lookaside memory] so as not to
    4353
    ** deplete the limited store of lookaside memory. Future versions of
    4354
    ** SQLite may act on this hint differently.
    4355
    **
    4356
    ** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt>
    4357
    ** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used
    4358
    ** to be required for any prepared statement that wanted to use the
    4359
    ** [sqlite3_normalized_sql()] interface.  However, the
    4360
    ** [sqlite3_normalized_sql()] interface is now available to all
    4361
    ** prepared statements, regardless of whether or not they use this
    4362
    ** flag.
    4363
    **
    4364
    ** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt>
    4365
    ** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler
    4366
    ** to return an error (error code SQLITE_ERROR) if the statement uses
    4367
    ** any virtual tables.
    4368
    **
    4369
    ** [[SQLITE_PREPARE_DONT_LOG]] <dt>SQLITE_PREPARE_DONT_LOG</dt>
    4370
    ** <dd>The SQLITE_PREPARE_DONT_LOG flag prevents SQL compiler
    4371
    ** errors from being sent to the error log defined by
    4372
    ** [SQLITE_CONFIG_LOG].  This can be used, for example, to do test
    4373
    ** compiles to see if some SQL syntax is well-formed, without generating
    4374
    ** messages on the global error log when it is not.  If the test compile
    4375
    ** fails, the sqlite3_prepare_v3() call returns the same error indications
    4376
    ** with or without this flag; it just omits the call to [sqlite3_log()] that
    4377
    ** logs the error.
    4378
    ** </dl>
    4379
    */
    4380
    #define SQLITE_PREPARE_PERSISTENT              0x01
    4381
    #define SQLITE_PREPARE_NORMALIZE               0x02
    4382
    #define SQLITE_PREPARE_NO_VTAB                 0x04
    4383
    #define SQLITE_PREPARE_DONT_LOG                0x10
    4384
    4385
    /*
    4386
    ** CAPI3REF: Compiling An SQL Statement
    4387
    ** KEYWORDS: {SQL statement compiler}
    4388
    ** METHOD: sqlite3
    4389
    ** CONSTRUCTOR: sqlite3_stmt
    4390
    **
    4391
    ** To execute an SQL statement, it must first be compiled into a byte-code
    4392
    ** program using one of these routines.  Or, in other words, these routines
    4393
    ** are constructors for the [prepared statement] object.
    4394
    **
    4395
    ** The preferred routine to use is [sqlite3_prepare_v2()].  The
    4396
    ** [sqlite3_prepare()] interface is legacy and should be avoided.
    4397
    ** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used
    4398
    ** for special purposes.
    4399
    **
    4400
    ** The use of the UTF-8 interfaces is preferred, as SQLite currently
    4401
    ** does all parsing using UTF-8.  The UTF-16 interfaces are provided
    4402
    ** as a convenience.  The UTF-16 interfaces work by converting the
    4403
    ** input text into UTF-8, then invoking the corresponding UTF-8 interface.
    4404
    **
    4405
    ** The first argument, "db", is a [database connection] obtained from a
    4406
    ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
    4407
    ** [sqlite3_open16()].  The database connection must not have been closed.
    4408
    **
    4409
    ** The second argument, "zSql", is the statement to be compiled, encoded
    4410
    ** as either UTF-8 or UTF-16.  The sqlite3_prepare(), sqlite3_prepare_v2(),
    4411
    ** and sqlite3_prepare_v3()
    4412
    ** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(),
    4413
    ** and sqlite3_prepare16_v3() use UTF-16.
    4414
    **
    4415
    ** ^If the nByte argument is negative, then zSql is read up to the
    4416
    ** first zero terminator. ^If nByte is positive, then it is the maximum
    4417
    ** number of bytes read from zSql.  When nByte is positive, zSql is read
    4418
    ** up to the first zero terminator or until the nByte bytes have been read,
    4419
    ** whichever comes first.  ^If nByte is zero, then no prepared
    4420
    ** statement is generated.
    4421
    ** If the caller knows that the supplied string is nul-terminated, then
    4422
    ** there is a small performance advantage to passing an nByte parameter that
    4423
    ** is the number of bytes in the input string <i>including</i>
    4424
    ** the nul-terminator.
    4425
    ** Note that nByte measure the length of the input in bytes, not
    4426
    ** characters, even for the UTF-16 interfaces.
    4427
    **
    4428
    ** ^If pzTail is not NULL then *pzTail is made to point to the first byte
    4429
    ** past the end of the first SQL statement in zSql.  These routines only
    4430
    ** compile the first statement in zSql, so *pzTail is left pointing to
    4431
    ** what remains uncompiled.
    4432
    **
    4433
    ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
    4434
    ** executed using [sqlite3_step()].  ^If there is an error, *ppStmt is set
    4435
    ** to NULL.  ^If the input text contains no SQL (if the input is an empty
    4436
    ** string or a comment) then *ppStmt is set to NULL.
    4437
    ** The calling procedure is responsible for deleting the compiled
    4438
    ** SQL statement using [sqlite3_finalize()] after it has finished with it.
    4439
    ** ppStmt may not be NULL.
    4440
    **
    4441
    ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
    4442
    ** otherwise an [error code] is returned.
    4443
    **
    4444
    ** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(),
    4445
    ** and sqlite3_prepare16_v3() interfaces are recommended for all new programs.
    4446
    ** The older interfaces (sqlite3_prepare() and sqlite3_prepare16())
    4447
    ** are retained for backwards compatibility, but their use is discouraged.
    4448
    ** ^In the "vX" interfaces, the prepared statement
    4449
    ** that is returned (the [sqlite3_stmt] object) contains a copy of the
    4450
    ** original SQL text. This causes the [sqlite3_step()] interface to
    4451
    ** behave differently in three ways:
    4452
    **
    4453
    ** <ol>
    4454
    ** <li>
    4455
    ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
    4456
    ** always used to do, [sqlite3_step()] will automatically recompile the SQL
    4457
    ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY]
    4458
    ** retries will occur before sqlite3_step() gives up and returns an error.
    4459
    ** </li>
    4460
    **
    4461
    ** <li>
    4462
    ** ^When an error occurs, [sqlite3_step()] will return one of the detailed
    4463
    ** [error codes] or [extended error codes].  ^The legacy behavior was that
    4464
    ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
    4465
    ** and the application would have to make a second call to [sqlite3_reset()]
    4466
    ** in order to find the underlying cause of the problem. With the "v2" prepare
    4467
    ** interfaces, the underlying reason for the error is returned immediately.
    4468
    ** </li>
    4469
    **
    4470
    ** <li>
    4471
    ** ^If the specific value bound to a [parameter | host parameter] in the
    4472
    ** WHERE clause might influence the choice of query plan for a statement,
    4473
    ** then the statement will be automatically recompiled, as if there had been
    4474
    ** a schema change, on the first [sqlite3_step()] call following any change
    4475
    ** to the [sqlite3_bind_text | bindings] of that [parameter].
    4476
    ** ^The specific value of a WHERE-clause [parameter] might influence the
    4477
    ** choice of query plan if the parameter is the left-hand side of a [LIKE]
    4478
    ** or [GLOB] operator or if the parameter is compared to an indexed column
    4479
    ** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled.
    4480
    ** </li>
    4481
    ** </ol>
    4482
    **
    4483
    ** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having
    4484
    ** the extra prepFlags parameter, which is a bit array consisting of zero or
    4485
    ** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags.  ^The
    4486
    ** sqlite3_prepare_v2() interface works exactly the same as
    4487
    ** sqlite3_prepare_v3() with a zero prepFlags parameter.
    4488
    */
    4489
    SQLITE_API int sqlite3_prepare(
    4490
      sqlite3 *db,            /* Database handle */
    4491
      const char *zSql,       /* SQL statement, UTF-8 encoded */
    4492
      int nByte,              /* Maximum length of zSql in bytes. */
    4493
      sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
    4494
      const char **pzTail     /* OUT: Pointer to unused portion of zSql */
    4495
    );
    4496
    SQLITE_API int sqlite3_prepare_v2(
    4497
      sqlite3 *db,            /* Database handle */
    4498
      const char *zSql,       /* SQL statement, UTF-8 encoded */
    4499
      int nByte,              /* Maximum length of zSql in bytes. */
    4500
      sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
    4501
      const char **pzTail     /* OUT: Pointer to unused portion of zSql */
    4502
    );
    4503
    SQLITE_API int sqlite3_prepare_v3(
    4504
      sqlite3 *db,            /* Database handle */
    4505
      const char *zSql,       /* SQL statement, UTF-8 encoded */
    4506
      int nByte,              /* Maximum length of zSql in bytes. */
    4507
      unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
    4508
      sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
    4509
      const char **pzTail     /* OUT: Pointer to unused portion of zSql */
    4510
    );
    4511
    SQLITE_API int sqlite3_prepare16(
    4512
      sqlite3 *db,            /* Database handle */
    4513
      const void *zSql,       /* SQL statement, UTF-16 encoded */
    4514
      int nByte,              /* Maximum length of zSql in bytes. */
    4515
      sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
    4516
      const void **pzTail     /* OUT: Pointer to unused portion of zSql */
    4517
    );
    4518
    SQLITE_API int sqlite3_prepare16_v2(
    4519
      sqlite3 *db,            /* Database handle */
    4520
      const void *zSql,       /* SQL statement, UTF-16 encoded */
    4521
      int nByte,              /* Maximum length of zSql in bytes. */
    4522
      sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
    4523
      const void **pzTail     /* OUT: Pointer to unused portion of zSql */
    4524
    );
    4525
    SQLITE_API int sqlite3_prepare16_v3(
    4526
      sqlite3 *db,            /* Database handle */
    4527
      const void *zSql,       /* SQL statement, UTF-16 encoded */
    4528
      int nByte,              /* Maximum length of zSql in bytes. */
    4529
      unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
    4530
      sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
    4531
      const void **pzTail     /* OUT: Pointer to unused portion of zSql */
    4532
    );
    4533
    4534
    /*
    4535
    ** CAPI3REF: Retrieving Statement SQL
    4536
    ** METHOD: sqlite3_stmt
    4537
    **
    4538
    ** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8
    4539
    ** SQL text used to create [prepared statement] P if P was
    4540
    ** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()],
    4541
    ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
    4542
    ** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8
    4543
    ** string containing the SQL text of prepared statement P with
    4544
    ** [bound parameters] expanded.
    4545
    ** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8
    4546
    ** string containing the normalized SQL text of prepared statement P.  The
    4547
    ** semantics used to normalize a SQL statement are unspecified and subject
    4548
    ** to change.  At a minimum, literal values will be replaced with suitable
    4549
    ** placeholders.
    4550
    **
    4551
    ** ^(For example, if a prepared statement is created using the SQL
    4552
    ** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345
    4553
    ** and parameter :xyz is unbound, then sqlite3_sql() will return
    4554
    ** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql()
    4555
    ** will return "SELECT 2345,NULL".)^
    4556
    **
    4557
    ** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory
    4558
    ** is available to hold the result, or if the result would exceed the
    4559
    ** the maximum string length determined by the [SQLITE_LIMIT_LENGTH].
    4560
    **
    4561
    ** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of
    4562
    ** bound parameter expansions.  ^The [SQLITE_OMIT_TRACE] compile-time
    4563
    ** option causes sqlite3_expanded_sql() to always return NULL.
    4564
    **
    4565
    ** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P)
    4566
    ** are managed by SQLite and are automatically freed when the prepared
    4567
    ** statement is finalized.
    4568
    ** ^The string returned by sqlite3_expanded_sql(P), on the other hand,
    4569
    ** is obtained from [sqlite3_malloc()] and must be freed by the application
    4570
    ** by passing it to [sqlite3_free()].
    4571
    **
    4572
    ** ^The sqlite3_normalized_sql() interface is only available if
    4573
    ** the [SQLITE_ENABLE_NORMALIZE] compile-time option is defined.
    4574
    */
    4575
    SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt);
    4576
    SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt);
    4577
    #ifdef SQLITE_ENABLE_NORMALIZE
    4578
    SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt);
    4579
    #endif
    4580
    4581
    /*
    4582
    ** CAPI3REF: Determine If An SQL Statement Writes The Database
    4583
    ** METHOD: sqlite3_stmt
    4584
    **
    4585
    ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
    4586
    ** and only if the [prepared statement] X makes no direct changes to
    4587
    ** the content of the database file.
    4588
    **
    4589
    ** Note that [application-defined SQL functions] or
    4590
    ** [virtual tables] might change the database indirectly as a side effect.
    4591
    ** ^(For example, if an application defines a function "eval()" that
    4592
    ** calls [sqlite3_exec()], then the following SQL statement would
    4593
    ** change the database file through side-effects:
    4594
    **
    4595
    ** <blockquote><pre>
    4596
    **    SELECT eval('DELETE FROM t1') FROM t2;
    4597
    ** </pre></blockquote>
    4598
    **
    4599
    ** But because the [SELECT] statement does not change the database file
    4600
    ** directly, sqlite3_stmt_readonly() would still return true.)^
    4601
    **
    4602
    ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
    4603
    ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
    4604
    ** since the statements themselves do not actually modify the database but
    4605
    ** rather they control the timing of when other statements modify the
    4606
    ** database.  ^The [ATTACH] and [DETACH] statements also cause
    4607
    ** sqlite3_stmt_readonly() to return true since, while those statements
    4608
    ** change the configuration of a database connection, they do not make
    4609
    ** changes to the content of the database files on disk.
    4610
    ** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since
    4611
    ** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and
    4612
    ** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so
    4613
    ** sqlite3_stmt_readonly() returns false for those commands.
    4614
    **
    4615
    ** ^This routine returns false if there is any possibility that the
    4616
    ** statement might change the database file.  ^A false return does
    4617
    ** not guarantee that the statement will change the database file.
    4618
    ** ^For example, an UPDATE statement might have a WHERE clause that
    4619
    ** makes it a no-op, but the sqlite3_stmt_readonly() result would still
    4620
    ** be false.  ^Similarly, a CREATE TABLE IF NOT EXISTS statement is a
    4621
    ** read-only no-op if the table already exists, but
    4622
    ** sqlite3_stmt_readonly() still returns false for such a statement.
    4623
    **
    4624
    ** ^If prepared statement X is an [EXPLAIN] or [EXPLAIN QUERY PLAN]
    4625
    ** statement, then sqlite3_stmt_readonly(X) returns the same value as
    4626
    ** if the EXPLAIN or EXPLAIN QUERY PLAN prefix were omitted.
    4627
    */
    4628
    SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
    4629
    4630
    /*
    4631
    ** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement
    4632
    ** METHOD: sqlite3_stmt
    4633
    **
    4634
    ** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the
    4635
    ** prepared statement S is an EXPLAIN statement, or 2 if the
    4636
    ** statement S is an EXPLAIN QUERY PLAN.
    4637
    ** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is
    4638
    ** an ordinary statement or a NULL pointer.
    4639
    */
    4640
    SQLITE_API int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt);
    4641
    4642
    /*
    4643
    ** CAPI3REF: Change The EXPLAIN Setting For A Prepared Statement
    4644
    ** METHOD: sqlite3_stmt
    4645
    **
    4646
    ** The sqlite3_stmt_explain(S,E) interface changes the EXPLAIN
    4647
    ** setting for [prepared statement] S.  If E is zero, then S becomes
    4648
    ** a normal prepared statement.  If E is 1, then S behaves as if
    4649
    ** its SQL text began with "[EXPLAIN]".  If E is 2, then S behaves as if
    4650
    ** its SQL text began with "[EXPLAIN QUERY PLAN]".
    4651
    **
    4652
    ** Calling sqlite3_stmt_explain(S,E) might cause S to be reprepared.
    4653
    ** SQLite tries to avoid a reprepare, but a reprepare might be necessary
    4654
    ** on the first transition into EXPLAIN or EXPLAIN QUERY PLAN mode.
    4655
    **
    4656
    ** Because of the potential need to reprepare, a call to
    4657
    ** sqlite3_stmt_explain(S,E) will fail with SQLITE_ERROR if S cannot be
    4658
    ** reprepared because it was created using [sqlite3_prepare()] instead of
    4659
    ** the newer [sqlite3_prepare_v2()] or [sqlite3_prepare_v3()] interfaces and
    4660
    ** hence has no saved SQL text with which to reprepare.
    4661
    **
    4662
    ** Changing the explain setting for a prepared statement does not change
    4663
    ** the original SQL text for the statement.  Hence, if the SQL text originally
    4664
    ** began with EXPLAIN or EXPLAIN QUERY PLAN, but sqlite3_stmt_explain(S,0)
    4665
    ** is called to convert the statement into an ordinary statement, the EXPLAIN
    4666
    ** or EXPLAIN QUERY PLAN keywords will still appear in the sqlite3_sql(S)
    4667
    ** output, even though the statement now acts like a normal SQL statement.
    4668
    **
    4669
    ** This routine returns SQLITE_OK if the explain mode is successfully
    4670
    ** changed, or an error code if the explain mode could not be changed.
    4671
    ** The explain mode cannot be changed while a statement is active.
    4672
    ** Hence, it is good practice to call [sqlite3_reset(S)]
    4673
    ** immediately prior to calling sqlite3_stmt_explain(S,E).
    4674
    */
    4675
    SQLITE_API int sqlite3_stmt_explain(sqlite3_stmt *pStmt, int eMode);
    4676
    4677
    /*
    4678
    ** CAPI3REF: Determine If A Prepared Statement Has Been Reset
    4679
    ** METHOD: sqlite3_stmt
    4680
    **
    4681
    ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the
    4682
    ** [prepared statement] S has been stepped at least once using
    4683
    ** [sqlite3_step(S)] but has neither run to completion (returned
    4684
    ** [SQLITE_DONE] from [sqlite3_step(S)]) nor
    4685
    ** been reset using [sqlite3_reset(S)].  ^The sqlite3_stmt_busy(S)
    4686
    ** interface returns false if S is a NULL pointer.  If S is not a
    4687
    ** NULL pointer and is not a pointer to a valid [prepared statement]
    4688
    ** object, then the behavior is undefined and probably undesirable.
    4689
    **
    4690
    ** This interface can be used in combination [sqlite3_next_stmt()]
    4691
    ** to locate all prepared statements associated with a database
    4692
    ** connection that are in need of being reset.  This can be used,
    4693
    ** for example, in diagnostic routines to search for prepared
    4694
    ** statements that are holding a transaction open.
    4695
    */
    4696
    SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*);
    4697
    4698
    /*
    4699
    ** CAPI3REF: Dynamically Typed Value Object
    4700
    ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
    4701
    **
    4702
    ** SQLite uses the sqlite3_value object to represent all values
    4703
    ** that can be stored in a database table. SQLite uses dynamic typing
    4704
    ** for the values it stores.  ^Values stored in sqlite3_value objects
    4705
    ** can be integers, floating point values, strings, BLOBs, or NULL.
    4706
    **
    4707
    ** An sqlite3_value object may be either "protected" or "unprotected".
    4708
    ** Some interfaces require a protected sqlite3_value.  Other interfaces
    4709
    ** will accept either a protected or an unprotected sqlite3_value.
    4710
    ** Every interface that accepts sqlite3_value arguments specifies
    4711
    ** whether or not it requires a protected sqlite3_value.  The
    4712
    ** [sqlite3_value_dup()] interface can be used to construct a new
    4713
    ** protected sqlite3_value from an unprotected sqlite3_value.
    4714
    **
    4715
    ** The terms "protected" and "unprotected" refer to whether or not
    4716
    ** a mutex is held.  An internal mutex is held for a protected
    4717
    ** sqlite3_value object but no mutex is held for an unprotected
    4718
    ** sqlite3_value object.  If SQLite is compiled to be single-threaded
    4719
    ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
    4720
    ** or if SQLite is run in one of reduced mutex modes
    4721
    ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
    4722
    ** then there is no distinction between protected and unprotected
    4723
    ** sqlite3_value objects and they can be used interchangeably.  However,
    4724
    ** for maximum code portability it is recommended that applications
    4725
    ** still make the distinction between protected and unprotected
    4726
    ** sqlite3_value objects even when not strictly required.
    4727
    **
    4728
    ** ^The sqlite3_value objects that are passed as parameters into the
    4729
    ** implementation of [application-defined SQL functions] are protected.
    4730
    ** ^The sqlite3_value objects returned by [sqlite3_vtab_rhs_value()]
    4731
    ** are protected.
    4732
    ** ^The sqlite3_value object returned by
    4733
    ** [sqlite3_column_value()] is unprotected.
    4734
    ** Unprotected sqlite3_value objects may only be used as arguments
    4735
    ** to [sqlite3_result_value()], [sqlite3_bind_value()], and
    4736
    ** [sqlite3_value_dup()].
    4737
    ** The [sqlite3_value_blob | sqlite3_value_type()] family of
    4738
    ** interfaces require protected sqlite3_value objects.
    4739
    */
    4740
    typedef struct sqlite3_value sqlite3_value;
    4741
    4742
    /*
    4743
    ** CAPI3REF: SQL Function Context Object
    4744
    **
    4745
    ** The context in which an SQL function executes is stored in an
    4746
    ** sqlite3_context object.  ^A pointer to an sqlite3_context object
    4747
    ** is always first parameter to [application-defined SQL functions].
    4748
    ** The application-defined SQL function implementation will pass this
    4749
    ** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
    4750
    ** [sqlite3_aggregate_context()], [sqlite3_user_data()],
    4751
    ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
    4752
    ** and/or [sqlite3_set_auxdata()].
    4753
    */
    4754
    typedef struct sqlite3_context sqlite3_context;
    4755
    4756
    /*
    4757
    ** CAPI3REF: Binding Values To Prepared Statements
    4758
    ** KEYWORDS: {host parameter} {host parameters} {host parameter name}
    4759
    ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
    4760
    ** METHOD: sqlite3_stmt
    4761
    **
    4762
    ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
    4763
    ** literals may be replaced by a [parameter] that matches one of the following
    4764
    ** templates:
    4765
    **
    4766
    ** <ul>
    4767
    ** <li>  ?
    4768
    ** <li>  ?NNN
    4769
    ** <li>  :VVV
    4770
    ** <li>  @VVV
    4771
    ** <li>  $VVV
    4772
    ** </ul>
    4773
    **
    4774
    ** In the templates above, NNN represents an integer literal,
    4775
    ** and VVV represents an alphanumeric identifier.)^  ^The values of these
    4776
    ** parameters (also called "host parameter names" or "SQL parameters")
    4777
    ** can be set using the sqlite3_bind_*() routines defined here.
    4778
    **
    4779
    ** ^The first argument to the sqlite3_bind_*() routines is always
    4780
    ** a pointer to the [sqlite3_stmt] object returned from
    4781
    ** [sqlite3_prepare_v2()] or its variants.
    4782
    **
    4783
    ** ^The second argument is the index of the SQL parameter to be set.
    4784
    ** ^The leftmost SQL parameter has an index of 1.  ^When the same named
    4785
    ** SQL parameter is used more than once, second and subsequent
    4786
    ** occurrences have the same index as the first occurrence.
    4787
    ** ^The index for named parameters can be looked up using the
    4788
    ** [sqlite3_bind_parameter_index()] API if desired.  ^The index
    4789
    ** for "?NNN" parameters is the value of NNN.
    4790
    ** ^The NNN value must be between 1 and the [sqlite3_limit()]
    4791
    ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 32766).
    4792
    **
    4793
    ** ^The third argument is the value to bind to the parameter.
    4794
    ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16()
    4795
    ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter
    4796
    ** is ignored and the end result is the same as sqlite3_bind_null().
    4797
    ** ^If the third parameter to sqlite3_bind_text() is not NULL, then
    4798
    ** it should be a pointer to well-formed UTF8 text.
    4799
    ** ^If the third parameter to sqlite3_bind_text16() is not NULL, then
    4800
    ** it should be a pointer to well-formed UTF16 text.
    4801
    ** ^If the third parameter to sqlite3_bind_text64() is not NULL, then
    4802
    ** it should be a pointer to a well-formed unicode string that is
    4803
    ** either UTF8 if the sixth parameter is SQLITE_UTF8, or UTF16
    4804
    ** otherwise.
    4805
    **
    4806
    ** [[byte-order determination rules]] ^The byte-order of
    4807
    ** UTF16 input text is determined by the byte-order mark (BOM, U+FEFF)
    4808
    ** found in the first character, which is removed, or in the absence of a BOM
    4809
    ** the byte order is the native byte order of the host
    4810
    ** machine for sqlite3_bind_text16() or the byte order specified in
    4811
    ** the 6th parameter for sqlite3_bind_text64().)^
    4812
    ** ^If UTF16 input text contains invalid unicode
    4813
    ** characters, then SQLite might change those invalid characters
    4814
    ** into the unicode replacement character: U+FFFD.
    4815
    **
    4816
    ** ^(In those routines that have a fourth argument, its value is the
    4817
    ** number of bytes in the parameter.  To be clear: the value is the
    4818
    ** number of <u>bytes</u> in the value, not the number of characters.)^
    4819
    ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16()
    4820
    ** is negative, then the length of the string is
    4821
    ** the number of bytes up to the first zero terminator.
    4822
    ** If the fourth parameter to sqlite3_bind_blob() is negative, then
    4823
    ** the behavior is undefined.
    4824
    ** If a non-negative fourth parameter is provided to sqlite3_bind_text()
    4825
    ** or sqlite3_bind_text16() or sqlite3_bind_text64() then
    4826
    ** that parameter must be the byte offset
    4827
    ** where the NUL terminator would occur assuming the string were NUL
    4828
    ** terminated.  If any NUL characters occur at byte offsets less than
    4829
    ** the value of the fourth parameter then the resulting string value will
    4830
    ** contain embedded NULs.  The result of expressions involving strings
    4831
    ** with embedded NULs is undefined.
    4832
    **
    4833
    ** ^The fifth argument to the BLOB and string binding interfaces controls
    4834
    ** or indicates the lifetime of the object referenced by the third parameter.
    4835
    ** These three options exist:
    4836
    ** ^ (1) A destructor to dispose of the BLOB or string after SQLite has finished
    4837
    ** with it may be passed. ^It is called to dispose of the BLOB or string even
    4838
    ** if the call to the bind API fails, except the destructor is not called if
    4839
    ** the third parameter is a NULL pointer or the fourth parameter is negative.
    4840
    ** ^ (2) The special constant, [SQLITE_STATIC], may be passed to indicate that
    4841
    ** the application remains responsible for disposing of the object. ^In this
    4842
    ** case, the object and the provided pointer to it must remain valid until
    4843
    ** either the prepared statement is finalized or the same SQL parameter is
    4844
    ** bound to something else, whichever occurs sooner.
    4845
    ** ^ (3) The constant, [SQLITE_TRANSIENT], may be passed to indicate that the
    4846
    ** object is to be copied prior to the return from sqlite3_bind_*(). ^The
    4847
    ** object and pointer to it must remain valid until then. ^SQLite will then
    4848
    ** manage the lifetime of its private copy.
    4849
    **
    4850
    ** ^The sixth argument to sqlite3_bind_text64() must be one of
    4851
    ** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]
    4852
    ** to specify the encoding of the text in the third parameter.  If
    4853
    ** the sixth argument to sqlite3_bind_text64() is not one of the
    4854
    ** allowed values shown above, or if the text encoding is different
    4855
    ** from the encoding specified by the sixth parameter, then the behavior
    4856
    ** is undefined.
    4857
    **
    4858
    ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
    4859
    ** is filled with zeroes.  ^A zeroblob uses a fixed amount of memory
    4860
    ** (just an integer to hold its size) while it is being processed.
    4861
    ** Zeroblobs are intended to serve as placeholders for BLOBs whose
    4862
    ** content is later written using
    4863
    ** [sqlite3_blob_open | incremental BLOB I/O] routines.
    4864
    ** ^A negative value for the zeroblob results in a zero-length BLOB.
    4865
    **
    4866
    ** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in
    4867
    ** [prepared statement] S to have an SQL value of NULL, but to also be
    4868
    ** associated with the pointer P of type T.  ^D is either a NULL pointer or
    4869
    ** a pointer to a destructor function for P. ^SQLite will invoke the
    4870
    ** destructor D with a single argument of P when it is finished using
    4871
    ** P.  The T parameter should be a static string, preferably a string
    4872
    ** literal. The sqlite3_bind_pointer() routine is part of the
    4873
    ** [pointer passing interface] added for SQLite 3.20.0.
    4874
    **
    4875
    ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
    4876
    ** for the [prepared statement] or with a prepared statement for which
    4877
    ** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
    4878
    ** then the call will return [SQLITE_MISUSE].  If any sqlite3_bind_()
    4879
    ** routine is passed a [prepared statement] that has been finalized, the
    4880
    ** result is undefined and probably harmful.
    4881
    **
    4882
    ** ^Bindings are not cleared by the [sqlite3_reset()] routine.
    4883
    ** ^Unbound parameters are interpreted as NULL.
    4884
    **
    4885
    ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
    4886
    ** [error code] if anything goes wrong.
    4887
    ** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB
    4888
    ** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or
    4889
    ** [SQLITE_MAX_LENGTH].
    4890
    ** ^[SQLITE_RANGE] is returned if the parameter
    4891
    ** index is out of range.  ^[SQLITE_NOMEM] is returned if malloc() fails.
    4892
    **
    4893
    ** See also: [sqlite3_bind_parameter_count()],
    4894
    ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
    4895
    */
    4896
    SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
    4897
    SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64,
    4898
                            void(*)(void*));
    4899
    SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double);
    4900
    SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int);
    4901
    SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
    4902
    SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int);
    4903
    SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*));
    4904
    SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
    4905
    SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64,
    4906
                             void(*)(void*), unsigned char encoding);
    4907
    SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
    4908
    SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*));
    4909
    SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
    4910
    SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64);
    4911
    4912
    /*
    4913
    ** CAPI3REF: Number Of SQL Parameters
    4914
    ** METHOD: sqlite3_stmt
    4915
    **
    4916
    ** ^This routine can be used to find the number of [SQL parameters]
    4917
    ** in a [prepared statement].  SQL parameters are tokens of the
    4918
    ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
    4919
    ** placeholders for values that are [sqlite3_bind_blob | bound]
    4920
    ** to the parameters at a later time.
    4921
    **
    4922
    ** ^(This routine actually returns the index of the largest (rightmost)
    4923
    ** parameter. For all forms except ?NNN, this will correspond to the
    4924
    ** number of unique parameters.  If parameters of the ?NNN form are used,
    4925
    ** there may be gaps in the list.)^
    4926
    **
    4927
    ** See also: [sqlite3_bind_blob|sqlite3_bind()],
    4928
    ** [sqlite3_bind_parameter_name()], and
    4929
    ** [sqlite3_bind_parameter_index()].
    4930
    */
    4931
    SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*);
    4932
    4933
    /*
    4934
    ** CAPI3REF: Name Of A Host Parameter
    4935
    ** METHOD: sqlite3_stmt
    4936
    **
    4937
    ** ^The sqlite3_bind_parameter_name(P,N) interface returns
    4938
    ** the name of the N-th [SQL parameter] in the [prepared statement] P.
    4939
    ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
    4940
    ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
    4941
    ** respectively.
    4942
    ** In other words, the initial ":" or "$" or "@" or "?"
    4943
    ** is included as part of the name.)^
    4944
    ** ^Parameters of the form "?" without a following integer have no name
    4945
    ** and are referred to as "nameless" or "anonymous parameters".
    4946
    **
    4947
    ** ^The first host parameter has an index of 1, not 0.
    4948
    **
    4949
    ** ^If the value N is out of range or if the N-th parameter is
    4950
    ** nameless, then NULL is returned.  ^The returned string is
    4951
    ** always in UTF-8 encoding even if the named parameter was
    4952
    ** originally specified as UTF-16 in [sqlite3_prepare16()],
    4953
    ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
    4954
    **
    4955
    ** See also: [sqlite3_bind_blob|sqlite3_bind()],
    4956
    ** [sqlite3_bind_parameter_count()], and
    4957
    ** [sqlite3_bind_parameter_index()].
    4958
    */
    4959
    SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
    4960
    4961
    /*
    4962
    ** CAPI3REF: Index Of A Parameter With A Given Name
    4963
    ** METHOD: sqlite3_stmt
    4964
    **
    4965
    ** ^Return the index of an SQL parameter given its name.  ^The
    4966
    ** index value returned is suitable for use as the second
    4967
    ** parameter to [sqlite3_bind_blob|sqlite3_bind()].  ^A zero
    4968
    ** is returned if no matching parameter is found.  ^The parameter
    4969
    ** name must be given in UTF-8 even if the original statement
    4970
    ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or
    4971
    ** [sqlite3_prepare16_v3()].
    4972
    **
    4973
    ** See also: [sqlite3_bind_blob|sqlite3_bind()],
    4974
    ** [sqlite3_bind_parameter_count()], and
    4975
    ** [sqlite3_bind_parameter_name()].
    4976
    */
    4977
    SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
    4978
    4979
    /*
    4980
    ** CAPI3REF: Reset All Bindings On A Prepared Statement
    4981
    ** METHOD: sqlite3_stmt
    4982
    **
    4983
    ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
    4984
    ** the [sqlite3_bind_blob | bindings] on a [prepared statement].
    4985
    ** ^Use this routine to reset all host parameters to NULL.
    4986
    */
    4987
    SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*);
    4988
    4989
    /*
    4990
    ** CAPI3REF: Number Of Columns In A Result Set
    4991
    ** METHOD: sqlite3_stmt
    4992
    **
    4993
    ** ^Return the number of columns in the result set returned by the
    4994
    ** [prepared statement]. ^If this routine returns 0, that means the
    4995
    ** [prepared statement] returns no data (for example an [UPDATE]).
    4996
    ** ^However, just because this routine returns a positive number does not
    4997
    ** mean that one or more rows of data will be returned.  ^A SELECT statement
    4998
    ** will always have a positive sqlite3_column_count() but depending on the
    4999
    ** WHERE clause constraints and the table content, it might return no rows.
    5000
    **
    5001
    ** See also: [sqlite3_data_count()]
    5002
    */
    5003
    SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt);
    5004
    5005
    /*
    5006
    ** CAPI3REF: Column Names In A Result Set
    5007
    ** METHOD: sqlite3_stmt
    5008
    **
    5009
    ** ^These routines return the name assigned to a particular column
    5010
    ** in the result set of a [SELECT] statement.  ^The sqlite3_column_name()
    5011
    ** interface returns a pointer to a zero-terminated UTF-8 string
    5012
    ** and sqlite3_column_name16() returns a pointer to a zero-terminated
    5013
    ** UTF-16 string.  ^The first parameter is the [prepared statement]
    5014
    ** that implements the [SELECT] statement. ^The second parameter is the
    5015
    ** column number.  ^The leftmost column is number 0.
    5016
    **
    5017
    ** ^The returned string pointer is valid until either the [prepared statement]
    5018
    ** is destroyed by [sqlite3_finalize()] or until the statement is automatically
    5019
    ** reprepared by the first call to [sqlite3_step()] for a particular run
    5020
    ** or until the next call to
    5021
    ** sqlite3_column_name() or sqlite3_column_name16() on the same column.
    5022
    **
    5023
    ** ^If sqlite3_malloc() fails during the processing of either routine
    5024
    ** (for example during a conversion from UTF-8 to UTF-16) then a
    5025
    ** NULL pointer is returned.
    5026
    **
    5027
    ** ^The name of a result column is the value of the "AS" clause for
    5028
    ** that column, if there is an AS clause.  If there is no AS clause
    5029
    ** then the name of the column is unspecified and may change from
    5030
    ** one release of SQLite to the next.
    5031
    */
    5032
    SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N);
    5033
    SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N);
    5034
    5035
    /*
    5036
    ** CAPI3REF: Source Of Data In A Query Result
    5037
    ** METHOD: sqlite3_stmt
    5038
    **
    5039
    ** ^These routines provide a means to determine the database, table, and
    5040
    ** table column that is the origin of a particular result column in a
    5041
    ** [SELECT] statement.
    5042
    ** ^The name of the database or table or column can be returned as
    5043
    ** either a UTF-8 or UTF-16 string.  ^The _database_ routines return
    5044
    ** the database name, the _table_ routines return the table name, and
    5045
    ** the origin_ routines return the column name.
    5046
    ** ^The returned string is valid until the [prepared statement] is destroyed
    5047
    ** using [sqlite3_finalize()] or until the statement is automatically
    5048
    ** reprepared by the first call to [sqlite3_step()] for a particular run
    5049
    ** or until the same information is requested
    5050
    ** again in a different encoding.
    5051
    **
    5052
    ** ^The names returned are the original un-aliased names of the
    5053
    ** database, table, and column.
    5054
    **
    5055
    ** ^The first argument to these interfaces is a [prepared statement].
    5056
    ** ^These functions return information about the Nth result column returned by
    5057
    ** the statement, where N is the second function argument.
    5058
    ** ^The left-most column is column 0 for these routines.
    5059
    **
    5060
    ** ^If the Nth column returned by the statement is an expression or
    5061
    ** subquery and is not a column value, then all of these functions return
    5062
    ** NULL.  ^These routines might also return NULL if a memory allocation error
    5063
    ** occurs.  ^Otherwise, they return the name of the attached database, table,
    5064
    ** or column that query result column was extracted from.
    5065
    **
    5066
    ** ^As with all other SQLite APIs, those whose names end with "16" return
    5067
    ** UTF-16 encoded strings and the other functions return UTF-8.
    5068
    **
    5069
    ** ^These APIs are only available if the library was compiled with the
    5070
    ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol.
    5071
    **
    5072
    ** If two or more threads call one or more
    5073
    ** [sqlite3_column_database_name | column metadata interfaces]
    5074
    ** for the same [prepared statement] and result column
    5075
    ** at the same time then the results are undefined.
    5076
    */
    5077
    SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int);
    5078
    SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
    5079
    SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int);
    5080
    SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
    5081
    SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
    5082
    SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
    5083
    5084
    /*
    5085
    ** CAPI3REF: Declared Datatype Of A Query Result
    5086
    ** METHOD: sqlite3_stmt
    5087
    **
    5088
    ** ^(The first parameter is a [prepared statement].
    5089
    ** If this statement is a [SELECT] statement and the Nth column of the
    5090
    ** returned result set of that [SELECT] is a table column (not an
    5091
    ** expression or subquery) then the declared type of the table
    5092
    ** column is returned.)^  ^If the Nth column of the result set is an
    5093
    ** expression or subquery, then a NULL pointer is returned.
    5094
    ** ^The returned string is always UTF-8 encoded.
    5095
    **
    5096
    ** ^(For example, given the database schema:
    5097
    **
    5098
    ** CREATE TABLE t1(c1 VARIANT);
    5099
    **
    5100
    ** and the following statement to be compiled:
    5101
    **
    5102
    ** SELECT c1 + 1, c1 FROM t1;
    5103
    **
    5104
    ** this routine would return the string "VARIANT" for the second result
    5105
    ** column (i==1), and a NULL pointer for the first result column (i==0).)^
    5106
    **
    5107
    ** ^SQLite uses dynamic run-time typing.  ^So just because a column
    5108
    ** is declared to contain a particular type does not mean that the
    5109
    ** data stored in that column is of the declared type.  SQLite is
    5110
    ** strongly typed, but the typing is dynamic not static.  ^Type
    5111
    ** is associated with individual values, not with the containers
    5112
    ** used to hold those values.
    5113
    */
    5114
    SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int);
    5115
    SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
    5116
    5117
    /*
    5118
    ** CAPI3REF: Evaluate An SQL Statement
    5119
    ** METHOD: sqlite3_stmt
    5120
    **
    5121
    ** After a [prepared statement] has been prepared using any of
    5122
    ** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()],
    5123
    ** or [sqlite3_prepare16_v3()] or one of the legacy
    5124
    ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
    5125
    ** must be called one or more times to evaluate the statement.
    5126
    **
    5127
    ** The details of the behavior of the sqlite3_step() interface depend
    5128
    ** on whether the statement was prepared using the newer "vX" interfaces
    5129
    ** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()],
    5130
    ** [sqlite3_prepare16_v2()] or the older legacy
    5131
    ** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()].  The use of the
    5132
    ** new "vX" interface is recommended for new applications but the legacy
    5133
    ** interface will continue to be supported.
    5134
    **
    5135
    ** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
    5136
    ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
    5137
    ** ^With the "v2" interface, any of the other [result codes] or
    5138
    ** [extended result codes] might be returned as well.
    5139
    **
    5140
    ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the
    5141
    ** database locks it needs to do its job.  ^If the statement is a [COMMIT]
    5142
    ** or occurs outside of an explicit transaction, then you can retry the
    5143
    ** statement.  If the statement is not a [COMMIT] and occurs within an
    5144
    ** explicit transaction then you should rollback the transaction before
    5145
    ** continuing.
    5146
    **
    5147
    ** ^[SQLITE_DONE] means that the statement has finished executing
    5148
    ** successfully.  sqlite3_step() should not be called again on this virtual
    5149
    ** machine without first calling [sqlite3_reset()] to reset the virtual
    5150
    ** machine back to its initial state.
    5151
    **
    5152
    ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]
    5153
    ** is returned each time a new row of data is ready for processing by the
    5154
    ** caller. The values may be accessed using the [column access functions].
    5155
    ** sqlite3_step() is called again to retrieve the next row of data.
    5156
    **
    5157
    ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint
    5158
    ** violation) has occurred.  sqlite3_step() should not be called again on
    5159
    ** the VM. More information may be found by calling [sqlite3_errmsg()].
    5160
    ** ^With the legacy interface, a more specific error code (for example,
    5161
    ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
    5162
    ** can be obtained by calling [sqlite3_reset()] on the
    5163
    ** [prepared statement].  ^In the "v2" interface,
    5164
    ** the more specific error code is returned directly by sqlite3_step().
    5165
    **
    5166
    ** [SQLITE_MISUSE] means that the this routine was called inappropriately.
    5167
    ** Perhaps it was called on a [prepared statement] that has
    5168
    ** already been [sqlite3_finalize | finalized] or on one that had
    5169
    ** previously returned [SQLITE_ERROR] or [SQLITE_DONE].  Or it could
    5170
    ** be the case that the same database connection is being used by two or
    5171
    ** more threads at the same moment in time.
    5172
    **
    5173
    ** For all versions of SQLite up to and including 3.6.23.1, a call to
    5174
    ** [sqlite3_reset()] was required after sqlite3_step() returned anything
    5175
    ** other than [SQLITE_ROW] before any subsequent invocation of
    5176
    ** sqlite3_step().  Failure to reset the prepared statement using
    5177
    ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from
    5178
    ** sqlite3_step().  But after [version 3.6.23.1] ([dateof:3.6.23.1]),
    5179
    ** sqlite3_step() began
    5180
    ** calling [sqlite3_reset()] automatically in this circumstance rather
    5181
    ** than returning [SQLITE_MISUSE].  This is not considered a compatibility
    5182
    ** break because any application that ever receives an SQLITE_MISUSE error
    5183
    ** is broken by definition.  The [SQLITE_OMIT_AUTORESET] compile-time option
    5184
    ** can be used to restore the legacy behavior.
    5185
    **
    5186
    ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
    5187
    ** API always returns a generic error code, [SQLITE_ERROR], following any
    5188
    ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE].  You must call
    5189
    ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
    5190
    ** specific [error codes] that better describes the error.
    5191
    ** We admit that this is a goofy design.  The problem has been fixed
    5192
    ** with the "v2" interface.  If you prepare all of your SQL statements
    5193
    ** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()]
    5194
    ** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead
    5195
    ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
    5196
    ** then the more specific [error codes] are returned directly
    5197
    ** by sqlite3_step().  The use of the "vX" interfaces is recommended.
    5198
    */
    5199
    SQLITE_API int sqlite3_step(sqlite3_stmt*);
    5200
    5201
    /*
    5202
    ** CAPI3REF: Number of columns in a result set
    5203
    ** METHOD: sqlite3_stmt
    5204
    **
    5205
    ** ^The sqlite3_data_count(P) interface returns the number of columns in the
    5206
    ** current row of the result set of [prepared statement] P.
    5207
    ** ^If prepared statement P does not have results ready to return
    5208
    ** (via calls to the [sqlite3_column_int | sqlite3_column()] family of
    5209
    ** interfaces) then sqlite3_data_count(P) returns 0.
    5210
    ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer.
    5211
    ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to
    5212
    ** [sqlite3_step](P) returned [SQLITE_DONE].  ^The sqlite3_data_count(P)
    5213
    ** will return non-zero if previous call to [sqlite3_step](P) returned
    5214
    ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum]
    5215
    ** where it always returns zero since each step of that multi-step
    5216
    ** pragma returns 0 columns of data.
    5217
    **
    5218
    ** See also: [sqlite3_column_count()]
    5219
    */
    5220
    SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
    5221
    5222
    /*
    5223
    ** CAPI3REF: Fundamental Datatypes
    5224
    ** KEYWORDS: SQLITE_TEXT
    5225
    **
    5226
    ** ^(Every value in SQLite has one of five fundamental datatypes:
    5227
    **
    5228
    ** <ul>
    5229
    ** <li> 64-bit signed integer
    5230
    ** <li> 64-bit IEEE floating point number
    5231
    ** <li> string
    5232
    ** <li> BLOB
    5233
    ** <li> NULL
    5234
    ** </ul>)^
    5235
    **
    5236
    ** These constants are codes for each of those types.
    5237
    **
    5238
    ** Note that the SQLITE_TEXT constant was also used in SQLite version 2
    5239
    ** for a completely different meaning.  Software that links against both
    5240
    ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
    5241
    ** SQLITE_TEXT.
    5242
    */
    5243
    #define SQLITE_INTEGER  1
    5244
    #define SQLITE_FLOAT    2
    5245
    #define SQLITE_BLOB     4
    5246
    #define SQLITE_NULL     5
    5247
    #ifdef SQLITE_TEXT
    5248
    # undef SQLITE_TEXT
    5249
    #else
    5250
    # define SQLITE_TEXT     3
    5251
    #endif
    5252
    #define SQLITE3_TEXT     3
    5253
    5254
    /*
    5255
    ** CAPI3REF: Result Values From A Query
    5256
    ** KEYWORDS: {column access functions}
    5257
    ** METHOD: sqlite3_stmt
    5258
    **
    5259
    ** <b>Summary:</b>
    5260
    ** <blockquote><table border=0 cellpadding=0 cellspacing=0>
    5261
    ** <tr><td><b>sqlite3_column_blob</b><td>&rarr;<td>BLOB result
    5262
    ** <tr><td><b>sqlite3_column_double</b><td>&rarr;<td>REAL result
    5263
    ** <tr><td><b>sqlite3_column_int</b><td>&rarr;<td>32-bit INTEGER result
    5264
    ** <tr><td><b>sqlite3_column_int64</b><td>&rarr;<td>64-bit INTEGER result
    5265
    ** <tr><td><b>sqlite3_column_text</b><td>&rarr;<td>UTF-8 TEXT result
    5266
    ** <tr><td><b>sqlite3_column_text16</b><td>&rarr;<td>UTF-16 TEXT result
    5267
    ** <tr><td><b>sqlite3_column_value</b><td>&rarr;<td>The result as an
    5268
    ** [sqlite3_value|unprotected sqlite3_value] object.
    5269
    ** <tr><td>&nbsp;<td>&nbsp;<td>&nbsp;
    5270
    ** <tr><td><b>sqlite3_column_bytes</b><td>&rarr;<td>Size of a BLOB
    5271
    ** or a UTF-8 TEXT result in bytes
    5272
    ** <tr><td><b>sqlite3_column_bytes16&nbsp;&nbsp;</b>
    5273
    ** <td>&rarr;&nbsp;&nbsp;<td>Size of UTF-16
    5274
    ** TEXT in bytes
    5275
    ** <tr><td><b>sqlite3_column_type</b><td>&rarr;<td>Default
    5276
    ** datatype of the result
    5277
    ** </table></blockquote>
    5278
    **
    5279
    ** <b>Details:</b>
    5280
    **
    5281
    ** ^These routines return information about a single column of the current
    5282
    ** result row of a query.  ^In every case the first argument is a pointer
    5283
    ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
    5284
    ** that was returned from [sqlite3_prepare_v2()] or one of its variants)
    5285
    ** and the second argument is the index of the column for which information
    5286
    ** should be returned. ^The leftmost column of the result set has the index 0.
    5287
    ** ^The number of columns in the result can be determined using
    5288
    ** [sqlite3_column_count()].
    5289
    **
    5290
    ** If the SQL statement does not currently point to a valid row, or if the
    5291
    ** column index is out of range, the result is undefined.
    5292
    ** These routines may only be called when the most recent call to
    5293
    ** [sqlite3_step()] has returned [SQLITE_ROW] and neither
    5294
    ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
    5295
    ** If any of these routines are called after [sqlite3_reset()] or
    5296
    ** [sqlite3_finalize()] or after [sqlite3_step()] has returned
    5297
    ** something other than [SQLITE_ROW], the results are undefined.
    5298
    ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
    5299
    ** are called from a different thread while any of these routines
    5300
    ** are pending, then the results are undefined.
    5301
    **
    5302
    ** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16)
    5303
    ** each return the value of a result column in a specific data format.  If
    5304
    ** the result column is not initially in the requested format (for example,
    5305
    ** if the query returns an integer but the sqlite3_column_text() interface
    5306
    ** is used to extract the value) then an automatic type conversion is performed.
    5307
    **
    5308
    ** ^The sqlite3_column_type() routine returns the
    5309
    ** [SQLITE_INTEGER | datatype code] for the initial data type
    5310
    ** of the result column.  ^The returned value is one of [SQLITE_INTEGER],
    5311
    ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].
    5312
    ** The return value of sqlite3_column_type() can be used to decide which
    5313
    ** of the first six interface should be used to extract the column value.
    5314
    ** The value returned by sqlite3_column_type() is only meaningful if no
    5315
    ** automatic type conversions have occurred for the value in question.
    5316
    ** After a type conversion, the result of calling sqlite3_column_type()
    5317
    ** is undefined, though harmless.  Future
    5318
    ** versions of SQLite may change the behavior of sqlite3_column_type()
    5319
    ** following a type conversion.
    5320
    **
    5321
    ** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes()
    5322
    ** or sqlite3_column_bytes16() interfaces can be used to determine the size
    5323
    ** of that BLOB or string.
    5324
    **
    5325
    ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
    5326
    ** routine returns the number of bytes in that BLOB or string.
    5327
    ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
    5328
    ** the string to UTF-8 and then returns the number of bytes.
    5329
    ** ^If the result is a numeric value then sqlite3_column_bytes() uses
    5330
    ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
    5331
    ** the number of bytes in that string.
    5332
    ** ^If the result is NULL, then sqlite3_column_bytes() returns zero.
    5333
    **
    5334
    ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16()
    5335
    ** routine returns the number of bytes in that BLOB or string.
    5336
    ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts
    5337
    ** the string to UTF-16 and then returns the number of bytes.
    5338
    ** ^If the result is a numeric value then sqlite3_column_bytes16() uses
    5339
    ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns
    5340
    ** the number of bytes in that string.
    5341
    ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero.
    5342
    **
    5343
    ** ^The values returned by [sqlite3_column_bytes()] and
    5344
    ** [sqlite3_column_bytes16()] do not include the zero terminators at the end
    5345
    ** of the string.  ^For clarity: the values returned by
    5346
    ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of
    5347
    ** bytes in the string, not the number of characters.
    5348
    **
    5349
    ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
    5350
    ** even empty strings, are always zero-terminated.  ^The return
    5351
    ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.
    5352
    **
    5353
    ** ^Strings returned by sqlite3_column_text16() always have the endianness
    5354
    ** which is native to the platform, regardless of the text encoding set
    5355
    ** for the database.
    5356
    **
    5357
    ** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an
    5358
    ** [unprotected sqlite3_value] object.  In a multithreaded environment,
    5359
    ** an unprotected sqlite3_value object may only be used safely with
    5360
    ** [sqlite3_bind_value()] and [sqlite3_result_value()].
    5361
    ** If the [unprotected sqlite3_value] object returned by
    5362
    ** [sqlite3_column_value()] is used in any other way, including calls
    5363
    ** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
    5364
    ** or [sqlite3_value_bytes()], the behavior is not threadsafe.
    5365
    ** Hence, the sqlite3_column_value() interface
    5366
    ** is normally only useful within the implementation of
    5367
    ** [application-defined SQL functions] or [virtual tables], not within
    5368
    ** top-level application code.
    5369
    **
    5370
    ** These routines may attempt to convert the datatype of the result.
    5371
    ** ^For example, if the internal representation is FLOAT and a text result
    5372
    ** is requested, [sqlite3_snprintf()] is used internally to perform the
    5373
    ** conversion automatically.  ^(The following table details the conversions
    5374
    ** that are applied:
    5375
    **
    5376
    ** <blockquote>
    5377
    ** <table border="1">
    5378
    ** <tr><th> Internal<br>Type <th> Requested<br>Type <th>  Conversion
    5379
    **
    5380
    ** <tr><td>  NULL    <td> INTEGER   <td> Result is 0
    5381
    ** <tr><td>  NULL    <td>  FLOAT    <td> Result is 0.0
    5382
    ** <tr><td>  NULL    <td>   TEXT    <td> Result is a NULL pointer
    5383
    ** <tr><td>  NULL    <td>   BLOB    <td> Result is a NULL pointer
    5384
    ** <tr><td> INTEGER  <td>  FLOAT    <td> Convert from integer to float
    5385
    ** <tr><td> INTEGER  <td>   TEXT    <td> ASCII rendering of the integer
    5386
    ** <tr><td> INTEGER  <td>   BLOB    <td> Same as INTEGER->TEXT
    5387
    ** <tr><td>  FLOAT   <td> INTEGER   <td> [CAST] to INTEGER
    5388
    ** <tr><td>  FLOAT   <td>   TEXT    <td> ASCII rendering of the float
    5389
    ** <tr><td>  FLOAT   <td>   BLOB    <td> [CAST] to BLOB
    5390
    ** <tr><td>  TEXT    <td> INTEGER   <td> [CAST] to INTEGER
    5391
    ** <tr><td>  TEXT    <td>  FLOAT    <td> [CAST] to REAL
    5392
    ** <tr><td>  TEXT    <td>   BLOB    <td> No change
    5393
    ** <tr><td>  BLOB    <td> INTEGER   <td> [CAST] to INTEGER
    5394
    ** <tr><td>  BLOB    <td>  FLOAT    <td> [CAST] to REAL
    5395
    ** <tr><td>  BLOB    <td>   TEXT    <td> [CAST] to TEXT, ensure zero terminator
    5396
    ** </table>
    5397
    ** </blockquote>)^
    5398
    **
    5399
    ** Note that when type conversions occur, pointers returned by prior
    5400
    ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
    5401
    ** sqlite3_column_text16() may be invalidated.
    5402
    ** Type conversions and pointer invalidations might occur
    5403
    ** in the following cases:
    5404
    **
    5405
    ** <ul>
    5406
    ** <li> The initial content is a BLOB and sqlite3_column_text() or
    5407
    **      sqlite3_column_text16() is called.  A zero-terminator might
    5408
    **      need to be added to the string.</li>
    5409
    ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
    5410
    **      sqlite3_column_text16() is called.  The content must be converted
    5411
    **      to UTF-16.</li>
    5412
    ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
    5413
    **      sqlite3_column_text() is called.  The content must be converted
    5414
    **      to UTF-8.</li>
    5415
    ** </ul>
    5416
    **
    5417
    ** ^Conversions between UTF-16be and UTF-16le are always done in place and do
    5418
    ** not invalidate a prior pointer, though of course the content of the buffer
    5419
    ** that the prior pointer references will have been modified.  Other kinds
    5420
    ** of conversion are done in place when it is possible, but sometimes they
    5421
    ** are not possible and in those cases prior pointers are invalidated.
    5422
    **
    5423
    ** The safest policy is to invoke these routines
    5424
    ** in one of the following ways:
    5425
    **
    5426
    ** <ul>
    5427
    **  <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
    5428
    **  <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
    5429
    **  <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
    5430
    ** </ul>
    5431
    **
    5432
    ** In other words, you should call sqlite3_column_text(),
    5433
    ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
    5434
    ** into the desired format, then invoke sqlite3_column_bytes() or
    5435
    ** sqlite3_column_bytes16() to find the size of the result.  Do not mix calls
    5436
    ** to sqlite3_column_text() or sqlite3_column_blob() with calls to
    5437
    ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
    5438
    ** with calls to sqlite3_column_bytes().
    5439
    **
    5440
    ** ^The pointers returned are valid until a type conversion occurs as
    5441
    ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
    5442
    ** [sqlite3_finalize()] is called.  ^The memory space used to hold strings
    5443
    ** and BLOBs is freed automatically.  Do not pass the pointers returned
    5444
    ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
    5445
    ** [sqlite3_free()].
    5446
    **
    5447
    ** As long as the input parameters are correct, these routines will only
    5448
    ** fail if an out-of-memory error occurs during a format conversion.
    5449
    ** Only the following subset of interfaces are subject to out-of-memory
    5450
    ** errors:
    5451
    **
    5452
    ** <ul>
    5453
    ** <li> sqlite3_column_blob()
    5454
    ** <li> sqlite3_column_text()
    5455
    ** <li> sqlite3_column_text16()
    5456
    ** <li> sqlite3_column_bytes()
    5457
    ** <li> sqlite3_column_bytes16()
    5458
    ** </ul>
    5459
    **
    5460
    ** If an out-of-memory error occurs, then the return value from these
    5461
    ** routines is the same as if the column had contained an SQL NULL value.
    5462
    ** Valid SQL NULL returns can be distinguished from out-of-memory errors
    5463
    ** by invoking the [sqlite3_errcode()] immediately after the suspect
    5464
    ** return value is obtained and before any
    5465
    ** other SQLite interface is called on the same [database connection].
    5466
    */
    5467
    SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
    5468
    SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol);
    5469
    SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol);
    5470
    SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
    5471
    SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
    5472
    SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
    5473
    SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
    5474
    SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
    5475
    SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
    5476
    SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol);
    5477
    5478
    /*
    5479
    ** CAPI3REF: Destroy A Prepared Statement Object
    5480
    ** DESTRUCTOR: sqlite3_stmt
    5481
    **
    5482
    ** ^The sqlite3_finalize() function is called to delete a [prepared statement].
    5483
    ** ^If the most recent evaluation of the statement encountered no errors
    5484
    ** or if the statement is never been evaluated, then sqlite3_finalize() returns
    5485
    ** SQLITE_OK.  ^If the most recent evaluation of statement S failed, then
    5486
    ** sqlite3_finalize(S) returns the appropriate [error code] or
    5487
    ** [extended error code].
    5488
    **
    5489
    ** ^The sqlite3_finalize(S) routine can be called at any point during
    5490
    ** the life cycle of [prepared statement] S:
    5491
    ** before statement S is ever evaluated, after
    5492
    ** one or more calls to [sqlite3_reset()], or after any call
    5493
    ** to [sqlite3_step()] regardless of whether or not the statement has
    5494
    ** completed execution.
    5495
    **
    5496
    ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op.
    5497
    **
    5498
    ** The application must finalize every [prepared statement] in order to avoid
    5499
    ** resource leaks.  It is a grievous error for the application to try to use
    5500
    ** a prepared statement after it has been finalized.  Any use of a prepared
    5501
    ** statement after it has been finalized can result in undefined and
    5502
    ** undesirable behavior such as segfaults and heap corruption.
    5503
    */
    5504
    SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt);
    5505
    5506
    /*
    5507
    ** CAPI3REF: Reset A Prepared Statement Object
    5508
    ** METHOD: sqlite3_stmt
    5509
    **
    5510
    ** The sqlite3_reset() function is called to reset a [prepared statement]
    5511
    ** object back to its initial state, ready to be re-executed.
    5512
    ** ^Any SQL statement variables that had values bound to them using
    5513
    ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
    5514
    ** Use [sqlite3_clear_bindings()] to reset the bindings.
    5515
    **
    5516
    ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S
    5517
    ** back to the beginning of its program.
    5518
    **
    5519
    ** ^The return code from [sqlite3_reset(S)] indicates whether or not
    5520
    ** the previous evaluation of prepared statement S completed successfully.
    5521
    ** ^If [sqlite3_step(S)] has never before been called on S or if
    5522
    ** [sqlite3_step(S)] has not been called since the previous call
    5523
    ** to [sqlite3_reset(S)], then [sqlite3_reset(S)] will return
    5524
    ** [SQLITE_OK].
    5525
    **
    5526
    ** ^If the most recent call to [sqlite3_step(S)] for the
    5527
    ** [prepared statement] S indicated an error, then
    5528
    ** [sqlite3_reset(S)] returns an appropriate [error code].
    5529
    ** ^The [sqlite3_reset(S)] interface might also return an [error code]
    5530
    ** if there were no prior errors but the process of resetting
    5531
    ** the prepared statement caused a new error. ^For example, if an
    5532
    ** [INSERT] statement with a [RETURNING] clause is only stepped one time,
    5533
    ** that one call to [sqlite3_step(S)] might return SQLITE_ROW but
    5534
    ** the overall statement might still fail and the [sqlite3_reset(S)] call
    5535
    ** might return SQLITE_BUSY if locking constraints prevent the
    5536
    ** database change from committing.  Therefore, it is important that
    5537
    ** applications check the return code from [sqlite3_reset(S)] even if
    5538
    ** no prior call to [sqlite3_step(S)] indicated a problem.
    5539
    **
    5540
    ** ^The [sqlite3_reset(S)] interface does not change the values
    5541
    ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
    5542
    */
    5543
    SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt);
    5544
    5545
    5546
    /*
    5547
    ** CAPI3REF: Create Or Redefine SQL Functions
    5548
    ** KEYWORDS: {function creation routines}
    5549
    ** METHOD: sqlite3
    5550
    **
    5551
    ** ^These functions (collectively known as "function creation routines")
    5552
    ** are used to add SQL functions or aggregates or to redefine the behavior
    5553
    ** of existing SQL functions or aggregates. The only differences between
    5554
    ** the three "sqlite3_create_function*" routines are the text encoding
    5555
    ** expected for the second parameter (the name of the function being
    5556
    ** created) and the presence or absence of a destructor callback for
    5557
    ** the application data pointer. Function sqlite3_create_window_function()
    5558
    ** is similar, but allows the user to supply the extra callback functions
    5559
    ** needed by [aggregate window functions].
    5560
    **
    5561
    ** ^The first parameter is the [database connection] to which the SQL
    5562
    ** function is to be added.  ^If an application uses more than one database
    5563
    ** connection then application-defined SQL functions must be added
    5564
    ** to each database connection separately.
    5565
    **
    5566
    ** ^The second parameter is the name of the SQL function to be created or
    5567
    ** redefined.  ^The length of the name is limited to 255 bytes in a UTF-8
    5568
    ** representation, exclusive of the zero-terminator.  ^Note that the name
    5569
    ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes.
    5570
    ** ^Any attempt to create a function with a longer name
    5571
    ** will result in [SQLITE_MISUSE] being returned.
    5572
    **
    5573
    ** ^The third parameter (nArg)
    5574
    ** is the number of arguments that the SQL function or
    5575
    ** aggregate takes. ^If this parameter is -1, then the SQL function or
    5576
    ** aggregate may take any number of arguments between 0 and the limit
    5577
    ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]).  If the third
    5578
    ** parameter is less than -1 or greater than 127 then the behavior is
    5579
    ** undefined.
    5580
    **
    5581
    ** ^The fourth parameter, eTextRep, specifies what
    5582
    ** [SQLITE_UTF8 | text encoding] this SQL function prefers for
    5583
    ** its parameters.  The application should set this parameter to
    5584
    ** [SQLITE_UTF16LE] if the function implementation invokes
    5585
    ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the
    5586
    ** implementation invokes [sqlite3_value_text16be()] on an input, or
    5587
    ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8]
    5588
    ** otherwise.  ^The same SQL function may be registered multiple times using
    5589
    ** different preferred text encodings, with different implementations for
    5590
    ** each encoding.
    5591
    ** ^When multiple implementations of the same function are available, SQLite
    5592
    ** will pick the one that involves the least amount of data conversion.
    5593
    **
    5594
    ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC]
    5595
    ** to signal that the function will always return the same result given
    5596
    ** the same inputs within a single SQL statement.  Most SQL functions are
    5597
    ** deterministic.  The built-in [random()] SQL function is an example of a
    5598
    ** function that is not deterministic.  The SQLite query planner is able to
    5599
    ** perform additional optimizations on deterministic functions, so use
    5600
    ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible.
    5601
    **
    5602
    ** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY]
    5603
    ** flag, which if present prevents the function from being invoked from
    5604
    ** within VIEWs, TRIGGERs, CHECK constraints, generated column expressions,
    5605
    ** index expressions, or the WHERE clause of partial indexes.
    5606
    **
    5607
    ** For best security, the [SQLITE_DIRECTONLY] flag is recommended for
    5608
    ** all application-defined SQL functions that do not need to be
    5609
    ** used inside of triggers, views, CHECK constraints, or other elements of
    5610
    ** the database schema.  This flag is especially recommended for SQL
    5611
    ** functions that have side effects or reveal internal application state.
    5612
    ** Without this flag, an attacker might be able to modify the schema of
    5613
    ** a database file to include invocations of the function with parameters
    5614
    ** chosen by the attacker, which the application will then execute when
    5615
    ** the database file is opened and read.
    5616
    **
    5617
    ** ^(The fifth parameter is an arbitrary pointer.  The implementation of the
    5618
    ** function can gain access to this pointer using [sqlite3_user_data()].)^
    5619
    **
    5620
    ** ^The sixth, seventh and eighth parameters passed to the three
    5621
    ** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are
    5622
    ** pointers to C-language functions that implement the SQL function or
    5623
    ** aggregate. ^A scalar SQL function requires an implementation of the xFunc
    5624
    ** callback only; NULL pointers must be passed as the xStep and xFinal
    5625
    ** parameters. ^An aggregate SQL function requires an implementation of xStep
    5626
    ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing
    5627
    ** SQL function or aggregate, pass NULL pointers for all three function
    5628
    ** callbacks.
    5629
    **
    5630
    ** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue
    5631
    ** and xInverse) passed to sqlite3_create_window_function are pointers to
    5632
    ** C-language callbacks that implement the new function. xStep and xFinal
    5633
    ** must both be non-NULL. xValue and xInverse may either both be NULL, in
    5634
    ** which case a regular aggregate function is created, or must both be
    5635
    ** non-NULL, in which case the new function may be used as either an aggregate
    5636
    ** or aggregate window function. More details regarding the implementation
    5637
    ** of aggregate window functions are
    5638
    ** [user-defined window functions|available here].
    5639
    **
    5640
    ** ^(If the final parameter to sqlite3_create_function_v2() or
    5641
    ** sqlite3_create_window_function() is not NULL, then it is the destructor for
    5642
    ** the application data pointer. The destructor is invoked when the function
    5643
    ** is deleted, either by being overloaded or when the database connection
    5644
    ** closes.)^ ^The destructor is also invoked if the call to
    5645
    ** sqlite3_create_function_v2() fails.  ^When the destructor callback is
    5646
    ** invoked, it is passed a single argument which is a copy of the application
    5647
    ** data pointer which was the fifth parameter to sqlite3_create_function_v2().
    5648
    **
    5649
    ** ^It is permitted to register multiple implementations of the same
    5650
    ** functions with the same name but with either differing numbers of
    5651
    ** arguments or differing preferred text encodings.  ^SQLite will use
    5652
    ** the implementation that most closely matches the way in which the
    5653
    ** SQL function is used.  ^A function implementation with a non-negative
    5654
    ** nArg parameter is a better match than a function implementation with
    5655
    ** a negative nArg.  ^A function where the preferred text encoding
    5656
    ** matches the database encoding is a better
    5657
    ** match than a function where the encoding is different.
    5658
    ** ^A function where the encoding difference is between UTF16le and UTF16be
    5659
    ** is a closer match than a function where the encoding difference is
    5660
    ** between UTF8 and UTF16.
    5661
    **
    5662
    ** ^Built-in functions may be overloaded by new application-defined functions.
    5663
    **
    5664
    ** ^An application-defined function is permitted to call other
    5665
    ** SQLite interfaces.  However, such calls must not
    5666
    ** close the database connection nor finalize or reset the prepared
    5667
    ** statement in which the function is running.
    5668
    */
    5669
    SQLITE_API int sqlite3_create_function(
    5670
      sqlite3 *db,
    5671
      const char *zFunctionName,
    5672
      int nArg,
    5673
      int eTextRep,
    5674
      void *pApp,
    5675
      void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
    5676
      void (*xStep)(sqlite3_context*,int,sqlite3_value**),
    5677
      void (*xFinal)(sqlite3_context*)
    5678
    );
    5679
    SQLITE_API int sqlite3_create_function16(
    5680
      sqlite3 *db,
    5681
      const void *zFunctionName,
    5682
      int nArg,
    5683
      int eTextRep,
    5684
      void *pApp,
    5685
      void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
    5686
      void (*xStep)(sqlite3_context*,int,sqlite3_value**),
    5687
      void (*xFinal)(sqlite3_context*)
    5688
    );
    5689
    SQLITE_API int sqlite3_create_function_v2(
    5690
      sqlite3 *db,
    5691
      const char *zFunctionName,
    5692
      int nArg,
    5693
      int eTextRep,
    5694
      void *pApp,
    5695
      void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
    5696
      void (*xStep)(sqlite3_context*,int,sqlite3_value**),
    5697
      void (*xFinal)(sqlite3_context*),
    5698
      void(*xDestroy)(void*)
    5699
    );
    5700
    SQLITE_API int sqlite3_create_window_function(
    5701
      sqlite3 *db,
    5702
      const char *zFunctionName,
    5703
      int nArg,
    5704
      int eTextRep,
    5705
      void *pApp,
    5706
      void (*xStep)(sqlite3_context*,int,sqlite3_value**),
    5707
      void (*xFinal)(sqlite3_context*),
    5708
      void (*xValue)(sqlite3_context*),
    5709
      void (*xInverse)(sqlite3_context*,int,sqlite3_value**),
    5710
      void(*xDestroy)(void*)
    5711
    );
    5712
    5713
    /*
    5714
    ** CAPI3REF: Text Encodings
    5715
    **
    5716
    ** These constant define integer codes that represent the various
    5717
    ** text encodings supported by SQLite.
    5718
    */
    5719
    #define SQLITE_UTF8           1    /* IMP: R-37514-35566 */
    5720
    #define SQLITE_UTF16LE        2    /* IMP: R-03371-37637 */
    5721
    #define SQLITE_UTF16BE        3    /* IMP: R-51971-34154 */
    5722
    #define SQLITE_UTF16          4    /* Use native byte order */
    5723
    #define SQLITE_ANY            5    /* Deprecated */
    5724
    #define SQLITE_UTF16_ALIGNED  8    /* sqlite3_create_collation only */
    5725
    5726
    /*
    5727
    ** CAPI3REF: Function Flags
    5728
    **
    5729
    ** These constants may be ORed together with the
    5730
    ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument
    5731
    ** to [sqlite3_create_function()], [sqlite3_create_function16()], or
    5732
    ** [sqlite3_create_function_v2()].
    5733
    **
    5734
    ** <dl>
    5735
    ** [[SQLITE_DETERMINISTIC]] <dt>SQLITE_DETERMINISTIC</dt><dd>
    5736
    ** The SQLITE_DETERMINISTIC flag means that the new function always gives
    5737
    ** the same output when the input parameters are the same.
    5738
    ** The [abs|abs() function] is deterministic, for example, but
    5739
    ** [randomblob|randomblob()] is not.  Functions must
    5740
    ** be deterministic in order to be used in certain contexts such as
    5741
    ** with the WHERE clause of [partial indexes] or in [generated columns].
    5742
    ** SQLite might also optimize deterministic functions by factoring them
    5743
    ** out of inner loops.
    5744
    ** </dd>
    5745
    **
    5746
    ** [[SQLITE_DIRECTONLY]] <dt>SQLITE_DIRECTONLY</dt><dd>
    5747
    ** The SQLITE_DIRECTONLY flag means that the function may only be invoked
    5748
    ** from top-level SQL, and cannot be used in VIEWs or TRIGGERs nor in
    5749
    ** schema structures such as [CHECK constraints], [DEFAULT clauses],
    5750
    ** [expression indexes], [partial indexes], or [generated columns].
    5751
    ** <p>
    5752
    ** The SQLITE_DIRECTONLY flag is recommended for any
    5753
    ** [application-defined SQL function]
    5754
    ** that has side-effects or that could potentially leak sensitive information.
    5755
    ** This will prevent attacks in which an application is tricked
    5756
    ** into using a database file that has had its schema surreptitiously
    5757
    ** modified to invoke the application-defined function in ways that are
    5758
    ** harmful.
    5759
    ** <p>
    5760
    ** Some people say it is good practice to set SQLITE_DIRECTONLY on all
    5761
    ** [application-defined SQL functions], regardless of whether or not they
    5762
    ** are security sensitive, as doing so prevents those functions from being used
    5763
    ** inside of the database schema, and thus ensures that the database
    5764
    ** can be inspected and modified using generic tools (such as the [CLI])
    5765
    ** that do not have access to the application-defined functions.
    5766
    ** </dd>
    5767
    **
    5768
    ** [[SQLITE_INNOCUOUS]] <dt>SQLITE_INNOCUOUS</dt><dd>
    5769
    ** The SQLITE_INNOCUOUS flag means that the function is unlikely
    5770
    ** to cause problems even if misused.  An innocuous function should have
    5771
    ** no side effects and should not depend on any values other than its
    5772
    ** input parameters. The [abs|abs() function] is an example of an
    5773
    ** innocuous function.
    5774
    ** The [load_extension() SQL function] is not innocuous because of its
    5775
    ** side effects.
    5776
    ** <p> SQLITE_INNOCUOUS is similar to SQLITE_DETERMINISTIC, but is not
    5777
    ** exactly the same.  The [random|random() function] is an example of a
    5778
    ** function that is innocuous but not deterministic.
    5779
    ** <p>Some heightened security settings
    5780
    ** ([SQLITE_DBCONFIG_TRUSTED_SCHEMA] and [PRAGMA trusted_schema=OFF])
    5781
    ** disable the use of SQL functions inside views and triggers and in
    5782
    ** schema structures such as [CHECK constraints], [DEFAULT clauses],
    5783
    ** [expression indexes], [partial indexes], and [generated columns] unless
    5784
    ** the function is tagged with SQLITE_INNOCUOUS.  Most built-in functions
    5785
    ** are innocuous.  Developers are advised to avoid using the
    5786
    ** SQLITE_INNOCUOUS flag for application-defined functions unless the
    5787
    ** function has been carefully audited and found to be free of potentially
    5788
    ** security-adverse side-effects and information-leaks.
    5789
    ** </dd>
    5790
    **
    5791
    ** [[SQLITE_SUBTYPE]] <dt>SQLITE_SUBTYPE</dt><dd>
    5792
    ** The SQLITE_SUBTYPE flag indicates to SQLite that a function might call
    5793
    ** [sqlite3_value_subtype()] to inspect the sub-types of its arguments.
    5794
    ** This flag instructs SQLite to omit some corner-case optimizations that
    5795
    ** might disrupt the operation of the [sqlite3_value_subtype()] function,
    5796
    ** causing it to return zero rather than the correct subtype().
    5797
    ** All SQL functions that invoke [sqlite3_value_subtype()] should have this
    5798
    ** property.  If the SQLITE_SUBTYPE property is omitted, then the return
    5799
    ** value from [sqlite3_value_subtype()] might sometimes be zero even though
    5800
    ** a non-zero subtype was specified by the function argument expression.
    5801
    **
    5802
    ** [[SQLITE_RESULT_SUBTYPE]] <dt>SQLITE_RESULT_SUBTYPE</dt><dd>
    5803
    ** The SQLITE_RESULT_SUBTYPE flag indicates to SQLite that a function might call
    5804
    ** [sqlite3_result_subtype()] to cause a sub-type to be associated with its
    5805
    ** result.
    5806
    ** Every function that invokes [sqlite3_result_subtype()] should have this
    5807
    ** property.  If it does not, then the call to [sqlite3_result_subtype()]
    5808
    ** might become a no-op if the function is used as term in an
    5809
    ** [expression index].  On the other hand, SQL functions that never invoke
    5810
    ** [sqlite3_result_subtype()] should avoid setting this property, as the
    5811
    ** purpose of this property is to disable certain optimizations that are
    5812
    ** incompatible with subtypes.
    5813
    **
    5814
    ** [[SQLITE_SELFORDER1]] <dt>SQLITE_SELFORDER1</dt><dd>
    5815
    ** The SQLITE_SELFORDER1 flag indicates that the function is an aggregate
    5816
    ** that internally orders the values provided to the first argument.  The
    5817
    ** ordered-set aggregate SQL notation with a single ORDER BY term can be
    5818
    ** used to invoke this function.  If the ordered-set aggregate notation is
    5819
    ** used on a function that lacks this flag, then an error is raised. Note
    5820
    ** that the ordered-set aggregate syntax is only available if SQLite is
    5821
    ** built using the -DSQLITE_ENABLE_ORDERED_SET_AGGREGATES compile-time option.
    5822
    ** </dd>
    5823
    ** </dl>
    5824
    */
    5825
    #define SQLITE_DETERMINISTIC    0x000000800
    5826
    #define SQLITE_DIRECTONLY       0x000080000
    5827
    #define SQLITE_SUBTYPE          0x000100000
    5828
    #define SQLITE_INNOCUOUS        0x000200000
    5829
    #define SQLITE_RESULT_SUBTYPE   0x001000000
    5830
    #define SQLITE_SELFORDER1       0x002000000
    5831
    5832
    /*
    5833
    ** CAPI3REF: Deprecated Functions
    5834
    ** DEPRECATED
    5835
    **
    5836
    ** These functions are [deprecated].  In order to maintain
    5837
    ** backwards compatibility with older code, these functions continue
    5838
    ** to be supported.  However, new applications should avoid
    5839
    ** the use of these functions.  To encourage programmers to avoid
    5840
    ** these functions, we will not explain what they do.
    5841
    */
    5842
    #ifndef SQLITE_OMIT_DEPRECATED
    5843
    SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*);
    5844
    SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*);
    5845
    SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
    5846
    SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void);
    5847
    SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void);
    5848
    SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),
    5849
                          void*,sqlite3_int64);
    5850
    #endif
    5851
    5852
    /*
    5853
    ** CAPI3REF: Obtaining SQL Values
    5854
    ** METHOD: sqlite3_value
    5855
    **
    5856
    ** <b>Summary:</b>
    5857
    ** <blockquote><table border=0 cellpadding=0 cellspacing=0>
    5858
    ** <tr><td><b>sqlite3_value_blob</b><td>&rarr;<td>BLOB value
    5859
    ** <tr><td><b>sqlite3_value_double</b><td>&rarr;<td>REAL value
    5860
    ** <tr><td><b>sqlite3_value_int</b><td>&rarr;<td>32-bit INTEGER value
    5861
    ** <tr><td><b>sqlite3_value_int64</b><td>&rarr;<td>64-bit INTEGER value
    5862
    ** <tr><td><b>sqlite3_value_pointer</b><td>&rarr;<td>Pointer value
    5863
    ** <tr><td><b>sqlite3_value_text</b><td>&rarr;<td>UTF-8 TEXT value
    5864
    ** <tr><td><b>sqlite3_value_text16</b><td>&rarr;<td>UTF-16 TEXT value in
    5865
    ** the native byteorder
    5866
    ** <tr><td><b>sqlite3_value_text16be</b><td>&rarr;<td>UTF-16be TEXT value
    5867
    ** <tr><td><b>sqlite3_value_text16le</b><td>&rarr;<td>UTF-16le TEXT value
    5868
    ** <tr><td>&nbsp;<td>&nbsp;<td>&nbsp;
    5869
    ** <tr><td><b>sqlite3_value_bytes</b><td>&rarr;<td>Size of a BLOB
    5870
    ** or a UTF-8 TEXT in bytes
    5871
    ** <tr><td><b>sqlite3_value_bytes16&nbsp;&nbsp;</b>
    5872
    ** <td>&rarr;&nbsp;&nbsp;<td>Size of UTF-16
    5873
    ** TEXT in bytes
    5874
    ** <tr><td><b>sqlite3_value_type</b><td>&rarr;<td>Default
    5875
    ** datatype of the value
    5876
    ** <tr><td><b>sqlite3_value_numeric_type&nbsp;&nbsp;</b>
    5877
    ** <td>&rarr;&nbsp;&nbsp;<td>Best numeric datatype of the value
    5878
    ** <tr><td><b>sqlite3_value_nochange&nbsp;&nbsp;</b>
    5879
    ** <td>&rarr;&nbsp;&nbsp;<td>True if the column is unchanged in an UPDATE
    5880
    ** against a virtual table.
    5881
    ** <tr><td><b>sqlite3_value_frombind&nbsp;&nbsp;</b>
    5882
    ** <td>&rarr;&nbsp;&nbsp;<td>True if value originated from a [bound parameter]
    5883
    ** </table></blockquote>
    5884
    **
    5885
    ** <b>Details:</b>
    5886
    **
    5887
    ** These routines extract type, size, and content information from
    5888
    ** [protected sqlite3_value] objects.  Protected sqlite3_value objects
    5889
    ** are used to pass parameter information into the functions that
    5890
    ** implement [application-defined SQL functions] and [virtual tables].
    5891
    **
    5892
    ** These routines work only with [protected sqlite3_value] objects.
    5893
    ** Any attempt to use these routines on an [unprotected sqlite3_value]
    5894
    ** is not threadsafe.
    5895
    **
    5896
    ** ^These routines work just like the corresponding [column access functions]
    5897
    ** except that these routines take a single [protected sqlite3_value] object
    5898
    ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
    5899
    **
    5900
    ** ^The sqlite3_value_text16() interface extracts a UTF-16 string
    5901
    ** in the native byte-order of the host machine.  ^The
    5902
    ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
    5903
    ** extract UTF-16 strings as big-endian and little-endian respectively.
    5904
    **
    5905
    ** ^If [sqlite3_value] object V was initialized
    5906
    ** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)]
    5907
    ** and if X and Y are strings that compare equal according to strcmp(X,Y),
    5908
    ** then sqlite3_value_pointer(V,Y) will return the pointer P.  ^Otherwise,
    5909
    ** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer()
    5910
    ** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
    5911
    **
    5912
    ** ^(The sqlite3_value_type(V) interface returns the
    5913
    ** [SQLITE_INTEGER | datatype code] for the initial datatype of the
    5914
    ** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER],
    5915
    ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^
    5916
    ** Other interfaces might change the datatype for an sqlite3_value object.
    5917
    ** For example, if the datatype is initially SQLITE_INTEGER and
    5918
    ** sqlite3_value_text(V) is called to extract a text value for that
    5919
    ** integer, then subsequent calls to sqlite3_value_type(V) might return
    5920
    ** SQLITE_TEXT.  Whether or not a persistent internal datatype conversion
    5921
    ** occurs is undefined and may change from one release of SQLite to the next.
    5922
    **
    5923
    ** ^(The sqlite3_value_numeric_type() interface attempts to apply
    5924
    ** numeric affinity to the value.  This means that an attempt is
    5925
    ** made to convert the value to an integer or floating point.  If
    5926
    ** such a conversion is possible without loss of information (in other
    5927
    ** words, if the value is a string that looks like a number)
    5928
    ** then the conversion is performed.  Otherwise no conversion occurs.
    5929
    ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
    5930
    **
    5931
    ** ^Within the [xUpdate] method of a [virtual table], the
    5932
    ** sqlite3_value_nochange(X) interface returns true if and only if
    5933
    ** the column corresponding to X is unchanged by the UPDATE operation
    5934
    ** that the xUpdate method call was invoked to implement and if
    5935
    ** and the prior [xColumn] method call that was invoked to extracted
    5936
    ** the value for that column returned without setting a result (probably
    5937
    ** because it queried [sqlite3_vtab_nochange()] and found that the column
    5938
    ** was unchanging).  ^Within an [xUpdate] method, any value for which
    5939
    ** sqlite3_value_nochange(X) is true will in all other respects appear
    5940
    ** to be a NULL value.  If sqlite3_value_nochange(X) is invoked anywhere other
    5941
    ** than within an [xUpdate] method call for an UPDATE statement, then
    5942
    ** the return value is arbitrary and meaningless.
    5943
    **
    5944
    ** ^The sqlite3_value_frombind(X) interface returns non-zero if the
    5945
    ** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()]
    5946
    ** interfaces.  ^If X comes from an SQL literal value, or a table column,
    5947
    ** or an expression, then sqlite3_value_frombind(X) returns zero.
    5948
    **
    5949
    ** Please pay particular attention to the fact that the pointer returned
    5950
    ** from [sqlite3_value_blob()], [sqlite3_value_text()], or
    5951
    ** [sqlite3_value_text16()] can be invalidated by a subsequent call to
    5952
    ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
    5953
    ** or [sqlite3_value_text16()].
    5954
    **
    5955
    ** These routines must be called from the same thread as
    5956
    ** the SQL function that supplied the [sqlite3_value*] parameters.
    5957
    **
    5958
    ** As long as the input parameter is correct, these routines can only
    5959
    ** fail if an out-of-memory error occurs during a format conversion.
    5960
    ** Only the following subset of interfaces are subject to out-of-memory
    5961
    ** errors:
    5962
    **
    5963
    ** <ul>
    5964
    ** <li> sqlite3_value_blob()
    5965
    ** <li> sqlite3_value_text()
    5966
    ** <li> sqlite3_value_text16()
    5967
    ** <li> sqlite3_value_text16le()
    5968
    ** <li> sqlite3_value_text16be()
    5969
    ** <li> sqlite3_value_bytes()
    5970
    ** <li> sqlite3_value_bytes16()
    5971
    ** </ul>
    5972
    **
    5973
    ** If an out-of-memory error occurs, then the return value from these
    5974
    ** routines is the same as if the column had contained an SQL NULL value.
    5975
    ** Valid SQL NULL returns can be distinguished from out-of-memory errors
    5976
    ** by invoking the [sqlite3_errcode()] immediately after the suspect
    5977
    ** return value is obtained and before any
    5978
    ** other SQLite interface is called on the same [database connection].
    5979
    */
    5980
    SQLITE_API const void *sqlite3_value_blob(sqlite3_value*);
    5981
    SQLITE_API double sqlite3_value_double(sqlite3_value*);
    5982
    SQLITE_API int sqlite3_value_int(sqlite3_value*);
    5983
    SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
    5984
    SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*);
    5985
    SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*);
    5986
    SQLITE_API const void *sqlite3_value_text16(sqlite3_value*);
    5987
    SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*);
    5988
    SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*);
    5989
    SQLITE_API int sqlite3_value_bytes(sqlite3_value*);
    5990
    SQLITE_API int sqlite3_value_bytes16(sqlite3_value*);
    5991
    SQLITE_API int sqlite3_value_type(sqlite3_value*);
    5992
    SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*);
    5993
    SQLITE_API int sqlite3_value_nochange(sqlite3_value*);
    5994
    SQLITE_API int sqlite3_value_frombind(sqlite3_value*);
    5995
    5996
    /*
    5997
    ** CAPI3REF: Report the internal text encoding state of an sqlite3_value object
    5998
    ** METHOD: sqlite3_value
    5999
    **
    6000
    ** ^(The sqlite3_value_encoding(X) interface returns one of [SQLITE_UTF8],
    6001
    ** [SQLITE_UTF16BE], or [SQLITE_UTF16LE] according to the current text encoding
    6002
    ** of the value X, assuming that X has type TEXT.)^  If sqlite3_value_type(X)
    6003
    ** returns something other than SQLITE_TEXT, then the return value from
    6004
    ** sqlite3_value_encoding(X) is meaningless.  ^Calls to
    6005
    ** [sqlite3_value_text(X)], [sqlite3_value_text16(X)], [sqlite3_value_text16be(X)],
    6006
    ** [sqlite3_value_text16le(X)], [sqlite3_value_bytes(X)], or
    6007
    ** [sqlite3_value_bytes16(X)] might change the encoding of the value X and
    6008
    ** thus change the return from subsequent calls to sqlite3_value_encoding(X).
    6009
    **
    6010
    ** This routine is intended for used by applications that test and validate
    6011
    ** the SQLite implementation.  This routine is inquiring about the opaque
    6012
    ** internal state of an [sqlite3_value] object.  Ordinary applications should
    6013
    ** not need to know what the internal state of an sqlite3_value object is and
    6014
    ** hence should not need to use this interface.
    6015
    */
    6016
    SQLITE_API int sqlite3_value_encoding(sqlite3_value*);
    6017
    6018
    /*
    6019
    ** CAPI3REF: Finding The Subtype Of SQL Values
    6020
    ** METHOD: sqlite3_value
    6021
    **
    6022
    ** The sqlite3_value_subtype(V) function returns the subtype for
    6023
    ** an [application-defined SQL function] argument V.  The subtype
    6024
    ** information can be used to pass a limited amount of context from
    6025
    ** one SQL function to another.  Use the [sqlite3_result_subtype()]
    6026
    ** routine to set the subtype for the return value of an SQL function.
    6027
    **
    6028
    ** Every [application-defined SQL function] that invokes this interface
    6029
    ** should include the [SQLITE_SUBTYPE] property in the text
    6030
    ** encoding argument when the function is [sqlite3_create_function|registered].
    6031
    ** If the [SQLITE_SUBTYPE] property is omitted, then sqlite3_value_subtype()
    6032
    ** might return zero instead of the upstream subtype in some corner cases.
    6033
    */
    6034
    SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*);
    6035
    6036
    /*
    6037
    ** CAPI3REF: Copy And Free SQL Values
    6038
    ** METHOD: sqlite3_value
    6039
    **
    6040
    ** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value]
    6041
    ** object V and returns a pointer to that copy.  ^The [sqlite3_value] returned
    6042
    ** is a [protected sqlite3_value] object even if the input is not.
    6043
    ** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a
    6044
    ** memory allocation fails. ^If V is a [pointer value], then the result
    6045
    ** of sqlite3_value_dup(V) is a NULL value.
    6046
    **
    6047
    ** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object
    6048
    ** previously obtained from [sqlite3_value_dup()].  ^If V is a NULL pointer
    6049
    ** then sqlite3_value_free(V) is a harmless no-op.
    6050
    */
    6051
    SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*);
    6052
    SQLITE_API void sqlite3_value_free(sqlite3_value*);
    6053
    6054
    /*
    6055
    ** CAPI3REF: Obtain Aggregate Function Context
    6056
    ** METHOD: sqlite3_context
    6057
    **
    6058
    ** Implementations of aggregate SQL functions use this
    6059
    ** routine to allocate memory for storing their state.
    6060
    **
    6061
    ** ^The first time the sqlite3_aggregate_context(C,N) routine is called
    6062
    ** for a particular aggregate function, SQLite allocates
    6063
    ** N bytes of memory, zeroes out that memory, and returns a pointer
    6064
    ** to the new memory. ^On second and subsequent calls to
    6065
    ** sqlite3_aggregate_context() for the same aggregate function instance,
    6066
    ** the same buffer is returned.  Sqlite3_aggregate_context() is normally
    6067
    ** called once for each invocation of the xStep callback and then one
    6068
    ** last time when the xFinal callback is invoked.  ^(When no rows match
    6069
    ** an aggregate query, the xStep() callback of the aggregate function
    6070
    ** implementation is never called and xFinal() is called exactly once.
    6071
    ** In those cases, sqlite3_aggregate_context() might be called for the
    6072
    ** first time from within xFinal().)^
    6073
    **
    6074
    ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer
    6075
    ** when first called if N is less than or equal to zero or if a memory
    6076
    ** allocation error occurs.
    6077
    **
    6078
    ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
    6079
    ** determined by the N parameter on the first successful call.  Changing the
    6080
    ** value of N in any subsequent call to sqlite3_aggregate_context() within
    6081
    ** the same aggregate function instance will not resize the memory
    6082
    ** allocation.)^  Within the xFinal callback, it is customary to set
    6083
    ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no
    6084
    ** pointless memory allocations occur.
    6085
    **
    6086
    ** ^SQLite automatically frees the memory allocated by
    6087
    ** sqlite3_aggregate_context() when the aggregate query concludes.
    6088
    **
    6089
    ** The first parameter must be a copy of the
    6090
    ** [sqlite3_context | SQL function context] that is the first parameter
    6091
    ** to the xStep or xFinal callback routine that implements the aggregate
    6092
    ** function.
    6093
    **
    6094
    ** This routine must be called from the same thread in which
    6095
    ** the aggregate SQL function is running.
    6096
    */
    6097
    SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
    6098
    6099
    /*
    6100
    ** CAPI3REF: User Data For Functions
    6101
    ** METHOD: sqlite3_context
    6102
    **
    6103
    ** ^The sqlite3_user_data() interface returns a copy of
    6104
    ** the pointer that was the pUserData parameter (the 5th parameter)
    6105
    ** of the [sqlite3_create_function()]
    6106
    ** and [sqlite3_create_function16()] routines that originally
    6107
    ** registered the application defined function.
    6108
    **
    6109
    ** This routine must be called from the same thread in which
    6110
    ** the application-defined function is running.
    6111
    */
    6112
    SQLITE_API void *sqlite3_user_data(sqlite3_context*);
    6113
    6114
    /*
    6115
    ** CAPI3REF: Database Connection For Functions
    6116
    ** METHOD: sqlite3_context
    6117
    **
    6118
    ** ^The sqlite3_context_db_handle() interface returns a copy of
    6119
    ** the pointer to the [database connection] (the 1st parameter)
    6120
    ** of the [sqlite3_create_function()]
    6121
    ** and [sqlite3_create_function16()] routines that originally
    6122
    ** registered the application defined function.
    6123
    */
    6124
    SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*);
    6125
    6126
    /*
    6127
    ** CAPI3REF: Function Auxiliary Data
    6128
    ** METHOD: sqlite3_context
    6129
    **
    6130
    ** These functions may be used by (non-aggregate) SQL functions to
    6131
    ** associate auxiliary data with argument values. If the same argument
    6132
    ** value is passed to multiple invocations of the same SQL function during
    6133
    ** query execution, under some circumstances the associated auxiliary data
    6134
    ** might be preserved.  An example of where this might be useful is in a
    6135
    ** regular-expression matching function. The compiled version of the regular
    6136
    ** expression can be stored as auxiliary data associated with the pattern string.
    6137
    ** Then as long as the pattern string remains the same,
    6138
    ** the compiled regular expression can be reused on multiple
    6139
    ** invocations of the same function.
    6140
    **
    6141
    ** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the auxiliary data
    6142
    ** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument
    6143
    ** value to the application-defined function.  ^N is zero for the left-most
    6144
    ** function argument.  ^If there is no auxiliary data
    6145
    ** associated with the function argument, the sqlite3_get_auxdata(C,N) interface
    6146
    ** returns a NULL pointer.
    6147
    **
    6148
    ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as auxiliary data for the
    6149
    ** N-th argument of the application-defined function.  ^Subsequent
    6150
    ** calls to sqlite3_get_auxdata(C,N) return P from the most recent
    6151
    ** sqlite3_set_auxdata(C,N,P,X) call if the auxiliary data is still valid or
    6152
    ** NULL if the auxiliary data has been discarded.
    6153
    ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL,
    6154
    ** SQLite will invoke the destructor function X with parameter P exactly
    6155
    ** once, when the auxiliary data is discarded.
    6156
    ** SQLite is free to discard the auxiliary data at any time, including: <ul>
    6157
    ** <li> ^(when the corresponding function parameter changes)^, or
    6158
    ** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the
    6159
    **      SQL statement)^, or
    6160
    ** <li> ^(when sqlite3_set_auxdata() is invoked again on the same
    6161
    **       parameter)^, or
    6162
    ** <li> ^(during the original sqlite3_set_auxdata() call when a memory
    6163
    **      allocation error occurs.)^
    6164
    ** <li> ^(during the original sqlite3_set_auxdata() call if the function
    6165
    **      is evaluated during query planning instead of during query execution,
    6166
    **      as sometimes happens with [SQLITE_ENABLE_STAT4].)^ </ul>
    6167
    **
    6168
    ** Note the last two bullets in particular.  The destructor X in
    6169
    ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the
    6170
    ** sqlite3_set_auxdata() interface even returns.  Hence sqlite3_set_auxdata()
    6171
    ** should be called near the end of the function implementation and the
    6172
    ** function implementation should not make any use of P after
    6173
    ** sqlite3_set_auxdata() has been called.  Furthermore, a call to
    6174
    ** sqlite3_get_auxdata() that occurs immediately after a corresponding call
    6175
    ** to sqlite3_set_auxdata() might still return NULL if an out-of-memory
    6176
    ** condition occurred during the sqlite3_set_auxdata() call or if the
    6177
    ** function is being evaluated during query planning rather than during
    6178
    ** query execution.
    6179
    **
    6180
    ** ^(In practice, auxiliary data is preserved between function calls for
    6181
    ** function parameters that are compile-time constants, including literal
    6182
    ** values and [parameters] and expressions composed from the same.)^
    6183
    **
    6184
    ** The value of the N parameter to these interfaces should be non-negative.
    6185
    ** Future enhancements may make use of negative N values to define new
    6186
    ** kinds of function caching behavior.
    6187
    **
    6188
    ** These routines must be called from the same thread in which
    6189
    ** the SQL function is running.
    6190
    **
    6191
    ** See also: [sqlite3_get_clientdata()] and [sqlite3_set_clientdata()].
    6192
    */
    6193
    SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N);
    6194
    SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));
    6195
    6196
    /*
    6197
    ** CAPI3REF: Database Connection Client Data
    6198
    ** METHOD: sqlite3
    6199
    **
    6200
    ** These functions are used to associate one or more named pointers
    6201
    ** with a [database connection].
    6202
    ** A call to sqlite3_set_clientdata(D,N,P,X) causes the pointer P
    6203
    ** to be attached to [database connection] D using name N.  Subsequent
    6204
    ** calls to sqlite3_get_clientdata(D,N) will return a copy of pointer P
    6205
    ** or a NULL pointer if there were no prior calls to
    6206
    ** sqlite3_set_clientdata() with the same values of D and N.
    6207
    ** Names are compared using strcmp() and are thus case sensitive.
    6208
    **
    6209
    ** If P and X are both non-NULL, then the destructor X is invoked with
    6210
    ** argument P on the first of the following occurrences:
    6211
    ** <ul>
    6212
    ** <li> An out-of-memory error occurs during the call to
    6213
    **      sqlite3_set_clientdata() which attempts to register pointer P.
    6214
    ** <li> A subsequent call to sqlite3_set_clientdata(D,N,P,X) is made
    6215
    **      with the same D and N parameters.
    6216
    ** <li> The database connection closes.  SQLite does not make any guarantees
    6217
    **      about the order in which destructors are called, only that all
    6218
    **      destructors will be called exactly once at some point during the
    6219
    **      database connection closing process.
    6220
    ** </ul>
    6221
    **
    6222
    ** SQLite does not do anything with client data other than invoke
    6223
    ** destructors on the client data at the appropriate time.  The intended
    6224
    ** use for client data is to provide a mechanism for wrapper libraries
    6225
    ** to store additional information about an SQLite database connection.
    6226
    **
    6227
    ** There is no limit (other than available memory) on the number of different
    6228
    ** client data pointers (with different names) that can be attached to a
    6229
    ** single database connection.  However, the implementation is optimized
    6230
    ** for the case of having only one or two different client data names.
    6231
    ** Applications and wrapper libraries are discouraged from using more than
    6232
    ** one client data name each.
    6233
    **
    6234
    ** There is no way to enumerate the client data pointers
    6235
    ** associated with a database connection.  The N parameter can be thought
    6236
    ** of as a secret key such that only code that knows the secret key is able
    6237
    ** to access the associated data.
    6238
    **
    6239
    ** Security Warning:  These interfaces should not be exposed in scripting
    6240
    ** languages or in other circumstances where it might be possible for an
    6241
    ** attacker to invoke them.  Any agent that can invoke these interfaces
    6242
    ** can probably also take control of the process.
    6243
    **
    6244
    ** Database connection client data is only available for SQLite
    6245
    ** version 3.44.0 ([dateof:3.44.0]) and later.
    6246
    **
    6247
    ** See also: [sqlite3_set_auxdata()] and [sqlite3_get_auxdata()].
    6248
    */
    6249
    SQLITE_API void *sqlite3_get_clientdata(sqlite3*,const char*);
    6250
    SQLITE_API int sqlite3_set_clientdata(sqlite3*, const char*, void*, void(*)(void*));
    6251
    6252
    /*
    6253
    ** CAPI3REF: Constants Defining Special Destructor Behavior
    6254
    **
    6255
    ** These are special values for the destructor that is passed in as the
    6256
    ** final argument to routines like [sqlite3_result_blob()].  ^If the destructor
    6257
    ** argument is SQLITE_STATIC, it means that the content pointer is constant
    6258
    ** and will never change.  It does not need to be destroyed.  ^The
    6259
    ** SQLITE_TRANSIENT value means that the content will likely change in
    6260
    ** the near future and that SQLite should make its own private copy of
    6261
    ** the content before returning.
    6262
    **
    6263
    ** The typedef is necessary to work around problems in certain
    6264
    ** C++ compilers.
    6265
    */
    6266
    typedef void (*sqlite3_destructor_type)(void*);
    6267
    20
    #define SQLITE_STATIC      ((sqlite3_destructor_type)0)
    6268
    #define SQLITE_TRANSIENT   ((sqlite3_destructor_type)-1)
    6269
    6270
    /*
    6271
    ** CAPI3REF: Setting The Result Of An SQL Function
    6272
    ** METHOD: sqlite3_context
    6273
    **
    6274
    ** These routines are used by the xFunc or xFinal callbacks that
    6275
    ** implement SQL functions and aggregates.  See
    6276
    ** [sqlite3_create_function()] and [sqlite3_create_function16()]
    6277
    ** for additional information.
    6278
    **
    6279
    ** These functions work very much like the [parameter binding] family of
    6280
    ** functions used to bind values to host parameters in prepared statements.
    6281
    ** Refer to the [SQL parameter] documentation for additional information.
    6282
    **
    6283
    ** ^The sqlite3_result_blob() interface sets the result from
    6284
    ** an application-defined function to be the BLOB whose content is pointed
    6285
    ** to by the second parameter and which is N bytes long where N is the
    6286
    ** third parameter.
    6287
    **
    6288
    ** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N)
    6289
    ** interfaces set the result of the application-defined function to be
    6290
    ** a BLOB containing all zero bytes and N bytes in size.
    6291
    **
    6292
    ** ^The sqlite3_result_double() interface sets the result from
    6293
    ** an application-defined function to be a floating point value specified
    6294
    ** by its 2nd argument.
    6295
    **
    6296
    ** ^The sqlite3_result_error() and sqlite3_result_error16() functions
    6297
    ** cause the implemented SQL function to throw an exception.
    6298
    ** ^SQLite uses the string pointed to by the
    6299
    ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
    6300
    ** as the text of an error message.  ^SQLite interprets the error
    6301
    ** message string from sqlite3_result_error() as UTF-8. ^SQLite
    6302
    ** interprets the string from sqlite3_result_error16() as UTF-16 using
    6303
    ** the same [byte-order determination rules] as [sqlite3_bind_text16()].
    6304
    ** ^If the third parameter to sqlite3_result_error()
    6305
    ** or sqlite3_result_error16() is negative then SQLite takes as the error
    6306
    ** message all text up through the first zero character.
    6307
    ** ^If the third parameter to sqlite3_result_error() or
    6308
    ** sqlite3_result_error16() is non-negative then SQLite takes that many
    6309
    ** bytes (not characters) from the 2nd parameter as the error message.
    6310
    ** ^The sqlite3_result_error() and sqlite3_result_error16()
    6311
    ** routines make a private copy of the error message text before
    6312
    ** they return.  Hence, the calling function can deallocate or
    6313
    ** modify the text after they return without harm.
    6314
    ** ^The sqlite3_result_error_code() function changes the error code
    6315
    ** returned by SQLite as a result of an error in a function.  ^By default,
    6316
    ** the error code is SQLITE_ERROR.  ^A subsequent call to sqlite3_result_error()
    6317
    ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
    6318
    **
    6319
    ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an
    6320
    ** error indicating that a string or BLOB is too long to represent.
    6321
    **
    6322
    ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an
    6323
    ** error indicating that a memory allocation failed.
    6324
    **
    6325
    ** ^The sqlite3_result_int() interface sets the return value
    6326
    ** of the application-defined function to be the 32-bit signed integer
    6327
    ** value given in the 2nd argument.
    6328
    ** ^The sqlite3_result_int64() interface sets the return value
    6329
    ** of the application-defined function to be the 64-bit signed integer
    6330
    ** value given in the 2nd argument.
    6331
    **
    6332
    ** ^The sqlite3_result_null() interface sets the return value
    6333
    ** of the application-defined function to be NULL.
    6334
    **
    6335
    ** ^The sqlite3_result_text(), sqlite3_result_text16(),
    6336
    ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
    6337
    ** set the return value of the application-defined function to be
    6338
    ** a text string which is represented as UTF-8, UTF-16 native byte order,
    6339
    ** UTF-16 little endian, or UTF-16 big endian, respectively.
    6340
    ** ^The sqlite3_result_text64() interface sets the return value of an
    6341
    ** application-defined function to be a text string in an encoding
    6342
    ** specified by the fifth (and last) parameter, which must be one
    6343
    ** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE].
    6344
    ** ^SQLite takes the text result from the application from
    6345
    ** the 2nd parameter of the sqlite3_result_text* interfaces.
    6346
    ** ^If the 3rd parameter to any of the sqlite3_result_text* interfaces
    6347
    ** other than sqlite3_result_text64() is negative, then SQLite computes
    6348
    ** the string length itself by searching the 2nd parameter for the first
    6349
    ** zero character.
    6350
    ** ^If the 3rd parameter to the sqlite3_result_text* interfaces
    6351
    ** is non-negative, then as many bytes (not characters) of the text
    6352
    ** pointed to by the 2nd parameter are taken as the application-defined
    6353
    ** function result.  If the 3rd parameter is non-negative, then it
    6354
    ** must be the byte offset into the string where the NUL terminator would
    6355
    ** appear if the string were NUL terminated.  If any NUL characters occur
    6356
    ** in the string at a byte offset that is less than the value of the 3rd
    6357
    ** parameter, then the resulting string will contain embedded NULs and the
    6358
    ** result of expressions operating on strings with embedded NULs is undefined.
    6359
    ** ^If the 4th parameter to the sqlite3_result_text* interfaces
    6360
    ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
    6361
    ** function as the destructor on the text or BLOB result when it has
    6362
    ** finished using that result.
    6363
    ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to
    6364
    ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
    6365
    ** assumes that the text or BLOB result is in constant space and does not
    6366
    ** copy the content of the parameter nor call a destructor on the content
    6367
    ** when it has finished using that result.
    6368
    ** ^If the 4th parameter to the sqlite3_result_text* interfaces
    6369
    ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
    6370
    ** then SQLite makes a copy of the result into space obtained
    6371
    ** from [sqlite3_malloc()] before it returns.
    6372
    **
    6373
    ** ^For the sqlite3_result_text16(), sqlite3_result_text16le(), and
    6374
    ** sqlite3_result_text16be() routines, and for sqlite3_result_text64()
    6375
    ** when the encoding is not UTF8, if the input UTF16 begins with a
    6376
    ** byte-order mark (BOM, U+FEFF) then the BOM is removed from the
    6377
    ** string and the rest of the string is interpreted according to the
    6378
    ** byte-order specified by the BOM.  ^The byte-order specified by
    6379
    ** the BOM at the beginning of the text overrides the byte-order
    6380
    ** specified by the interface procedure.  ^So, for example, if
    6381
    ** sqlite3_result_text16le() is invoked with text that begins
    6382
    ** with bytes 0xfe, 0xff (a big-endian byte-order mark) then the
    6383
    ** first two bytes of input are skipped and the remaining input
    6384
    ** is interpreted as UTF16BE text.
    6385
    **
    6386
    ** ^For UTF16 input text to the sqlite3_result_text16(),
    6387
    ** sqlite3_result_text16be(), sqlite3_result_text16le(), and
    6388
    ** sqlite3_result_text64() routines, if the text contains invalid
    6389
    ** UTF16 characters, the invalid characters might be converted
    6390
    ** into the unicode replacement character, U+FFFD.
    6391
    **
    6392
    ** ^The sqlite3_result_value() interface sets the result of
    6393
    ** the application-defined function to be a copy of the
    6394
    ** [unprotected sqlite3_value] object specified by the 2nd parameter.  ^The
    6395
    ** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
    6396
    ** so that the [sqlite3_value] specified in the parameter may change or
    6397
    ** be deallocated after sqlite3_result_value() returns without harm.
    6398
    ** ^A [protected sqlite3_value] object may always be used where an
    6399
    ** [unprotected sqlite3_value] object is required, so either
    6400
    ** kind of [sqlite3_value] object can be used with this interface.
    6401
    **
    6402
    ** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an
    6403
    ** SQL NULL value, just like [sqlite3_result_null(C)], except that it
    6404
    ** also associates the host-language pointer P or type T with that
    6405
    ** NULL value such that the pointer can be retrieved within an
    6406
    ** [application-defined SQL function] using [sqlite3_value_pointer()].
    6407
    ** ^If the D parameter is not NULL, then it is a pointer to a destructor
    6408
    ** for the P parameter.  ^SQLite invokes D with P as its only argument
    6409
    ** when SQLite is finished with P.  The T parameter should be a static
    6410
    ** string and preferably a string literal. The sqlite3_result_pointer()
    6411
    ** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
    6412
    **
    6413
    ** If these routines are called from within a different thread
    6414
    ** than the one containing the application-defined function that received
    6415
    ** the [sqlite3_context] pointer, the results are undefined.
    6416
    */
    6417
    SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
    6418
    SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*,
    6419
                               sqlite3_uint64,void(*)(void*));
    6420
    SQLITE_API void sqlite3_result_double(sqlite3_context*, double);
    6421
    SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int);
    6422
    SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int);
    6423
    SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*);
    6424
    SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*);
    6425
    SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int);
    6426
    SQLITE_API void sqlite3_result_int(sqlite3_context*, int);
    6427
    SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
    6428
    SQLITE_API void sqlite3_result_null(sqlite3_context*);
    6429
    SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
    6430
    SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64,
    6431
                               void(*)(void*), unsigned char encoding);
    6432
    SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
    6433
    SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
    6434
    SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
    6435
    SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
    6436
    SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*));
    6437
    SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n);
    6438
    SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n);
    6439
    6440
    6441
    /*
    6442
    ** CAPI3REF: Setting The Subtype Of An SQL Function
    6443
    ** METHOD: sqlite3_context
    6444
    **
    6445
    ** The sqlite3_result_subtype(C,T) function causes the subtype of
    6446
    ** the result from the [application-defined SQL function] with
    6447
    ** [sqlite3_context] C to be the value T.  Only the lower 8 bits
    6448
    ** of the subtype T are preserved in current versions of SQLite;
    6449
    ** higher order bits are discarded.
    6450
    ** The number of subtype bytes preserved by SQLite might increase
    6451
    ** in future releases of SQLite.
    6452
    **
    6453
    ** Every [application-defined SQL function] that invokes this interface
    6454
    ** should include the [SQLITE_RESULT_SUBTYPE] property in its
    6455
    ** text encoding argument when the SQL function is
    6456
    ** [sqlite3_create_function|registered].  If the [SQLITE_RESULT_SUBTYPE]
    6457
    ** property is omitted from the function that invokes sqlite3_result_subtype(),
    6458
    ** then in some cases the sqlite3_result_subtype() might fail to set
    6459
    ** the result subtype.
    6460
    **
    6461
    ** If SQLite is compiled with -DSQLITE_STRICT_SUBTYPE=1, then any
    6462
    ** SQL function that invokes the sqlite3_result_subtype() interface
    6463
    ** and that does not have the SQLITE_RESULT_SUBTYPE property will raise
    6464
    ** an error.  Future versions of SQLite might enable -DSQLITE_STRICT_SUBTYPE=1
    6465
    ** by default.
    6466
    */
    6467
    SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int);
    6468
    6469
    /*
    6470
    ** CAPI3REF: Define New Collating Sequences
    6471
    ** METHOD: sqlite3
    6472
    **
    6473
    ** ^These functions add, remove, or modify a [collation] associated
    6474
    ** with the [database connection] specified as the first argument.
    6475
    **
    6476
    ** ^The name of the collation is a UTF-8 string
    6477
    ** for sqlite3_create_collation() and sqlite3_create_collation_v2()
    6478
    ** and a UTF-16 string in native byte order for sqlite3_create_collation16().
    6479
    ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are
    6480
    ** considered to be the same name.
    6481
    **
    6482
    ** ^(The third argument (eTextRep) must be one of the constants:
    6483
    ** <ul>
    6484
    ** <li> [SQLITE_UTF8],
    6485
    ** <li> [SQLITE_UTF16LE],
    6486
    ** <li> [SQLITE_UTF16BE],
    6487
    ** <li> [SQLITE_UTF16], or
    6488
    ** <li> [SQLITE_UTF16_ALIGNED].
    6489
    ** </ul>)^
    6490
    ** ^The eTextRep argument determines the encoding of strings passed
    6491
    ** to the collating function callback, xCompare.
    6492
    ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep
    6493
    ** force strings to be UTF16 with native byte order.
    6494
    ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin
    6495
    ** on an even byte address.
    6496
    **
    6497
    ** ^The fourth argument, pArg, is an application data pointer that is passed
    6498
    ** through as the first argument to the collating function callback.
    6499
    **
    6500
    ** ^The fifth argument, xCompare, is a pointer to the collating function.
    6501
    ** ^Multiple collating functions can be registered using the same name but
    6502
    ** with different eTextRep parameters and SQLite will use whichever
    6503
    ** function requires the least amount of data transformation.
    6504
    ** ^If the xCompare argument is NULL then the collating function is
    6505
    ** deleted.  ^When all collating functions having the same name are deleted,
    6506
    ** that collation is no longer usable.
    6507
    **
    6508
    ** ^The collating function callback is invoked with a copy of the pArg
    6509
    ** application data pointer and with two strings in the encoding specified
    6510
    ** by the eTextRep argument.  The two integer parameters to the collating
    6511
    ** function callback are the length of the two strings, in bytes. The collating
    6512
    ** function must return an integer that is negative, zero, or positive
    6513
    ** if the first string is less than, equal to, or greater than the second,
    6514
    ** respectively.  A collating function must always return the same answer
    6515
    ** given the same inputs.  If two or more collating functions are registered
    6516
    ** to the same collation name (using different eTextRep values) then all
    6517
    ** must give an equivalent answer when invoked with equivalent strings.
    6518
    ** The collating function must obey the following properties for all
    6519
    ** strings A, B, and C:
    6520
    **
    6521
    ** <ol>
    6522
    ** <li> If A==B then B==A.
    6523
    ** <li> If A==B and B==C then A==C.
    6524
    ** <li> If A&lt;B THEN B&gt;A.
    6525
    ** <li> If A&lt;B and B&lt;C then A&lt;C.
    6526
    ** </ol>
    6527
    **
    6528
    ** If a collating function fails any of the above constraints and that
    6529
    ** collating function is registered and used, then the behavior of SQLite
    6530
    ** is undefined.
    6531
    **
    6532
    ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()
    6533
    ** with the addition that the xDestroy callback is invoked on pArg when
    6534
    ** the collating function is deleted.
    6535
    ** ^Collating functions are deleted when they are overridden by later
    6536
    ** calls to the collation creation functions or when the
    6537
    ** [database connection] is closed using [sqlite3_close()].
    6538
    **
    6539
    ** ^The xDestroy callback is <u>not</u> called if the
    6540
    ** sqlite3_create_collation_v2() function fails.  Applications that invoke
    6541
    ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should
    6542
    ** check the return code and dispose of the application data pointer
    6543
    ** themselves rather than expecting SQLite to deal with it for them.
    6544
    ** This is different from every other SQLite interface.  The inconsistency
    6545
    ** is unfortunate but cannot be changed without breaking backwards
    6546
    ** compatibility.
    6547
    **
    6548
    ** See also:  [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
    6549
    */
    6550
    SQLITE_API int sqlite3_create_collation(
    6551
      sqlite3*,
    6552
      const char *zName,
    6553
      int eTextRep,
    6554
      void *pArg,
    6555
      int(*xCompare)(void*,int,const void*,int,const void*)
    6556
    );
    6557
    SQLITE_API int sqlite3_create_collation_v2(
    6558
      sqlite3*,
    6559
      const char *zName,
    6560
      int eTextRep,
    6561
      void *pArg,
    6562
      int(*xCompare)(void*,int,const void*,int,const void*),
    6563
      void(*xDestroy)(void*)
    6564
    );
    6565
    SQLITE_API int sqlite3_create_collation16(
    6566
      sqlite3*,
    6567
      const void *zName,
    6568
      int eTextRep,
    6569
      void *pArg,
    6570
      int(*xCompare)(void*,int,const void*,int,const void*)
    6571
    );
    6572
    6573
    /*
    6574
    ** CAPI3REF: Collation Needed Callbacks
    6575
    ** METHOD: sqlite3
    6576
    **
    6577
    ** ^To avoid having to register all collation sequences before a database
    6578
    ** can be used, a single callback function may be registered with the
    6579
    ** [database connection] to be invoked whenever an undefined collation
    6580
    ** sequence is required.
    6581
    **
    6582
    ** ^If the function is registered using the sqlite3_collation_needed() API,
    6583
    ** then it is passed the names of undefined collation sequences as strings
    6584
    ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,
    6585
    ** the names are passed as UTF-16 in machine native byte order.
    6586
    ** ^A call to either function replaces the existing collation-needed callback.
    6587
    **
    6588
    ** ^(When the callback is invoked, the first argument passed is a copy
    6589
    ** of the second argument to sqlite3_collation_needed() or
    6590
    ** sqlite3_collation_needed16().  The second argument is the database
    6591
    ** connection.  The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
    6592
    ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
    6593
    ** sequence function required.  The fourth parameter is the name of the
    6594
    ** required collation sequence.)^
    6595
    **
    6596
    ** The callback function should register the desired collation using
    6597
    ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
    6598
    ** [sqlite3_create_collation_v2()].
    6599
    */
    6600
    SQLITE_API int sqlite3_collation_needed(
    6601
      sqlite3*,
    6602
      void*,
    6603
      void(*)(void*,sqlite3*,int eTextRep,const char*)
    6604
    );
    6605
    SQLITE_API int sqlite3_collation_needed16(
    6606
      sqlite3*,
    6607
      void*,
    6608
      void(*)(void*,sqlite3*,int eTextRep,const void*)
    6609
    );
    6610
    6611
    #ifdef SQLITE_ENABLE_CEROD
    6612
    /*
    6613
    ** Specify the activation key for a CEROD database.  Unless
    6614
    ** activated, none of the CEROD routines will work.
    6615
    */
    6616
    SQLITE_API void sqlite3_activate_cerod(
    6617
      const char *zPassPhrase        /* Activation phrase */
    6618
    );
    6619
    #endif
    6620
    6621
    /*
    6622
    ** CAPI3REF: Suspend Execution For A Short Time
    6623
    **
    6624
    ** The sqlite3_sleep() function causes the current thread to suspend execution
    6625
    ** for at least a number of milliseconds specified in its parameter.
    6626
    **
    6627
    ** If the operating system does not support sleep requests with
    6628
    ** millisecond time resolution, then the time will be rounded up to
    6629
    ** the nearest second. The number of milliseconds of sleep actually
    6630
    ** requested from the operating system is returned.
    6631
    **
    6632
    ** ^SQLite implements this interface by calling the xSleep()
    6633
    ** method of the default [sqlite3_vfs] object.  If the xSleep() method
    6634
    ** of the default VFS is not implemented correctly, or not implemented at
    6635
    ** all, then the behavior of sqlite3_sleep() may deviate from the description
    6636
    ** in the previous paragraphs.
    6637
    **
    6638
    ** If a negative argument is passed to sqlite3_sleep() the results vary by
    6639
    ** VFS and operating system.  Some system treat a negative argument as an
    6640
    ** instruction to sleep forever.  Others understand it to mean do not sleep
    6641
    ** at all. ^In SQLite version 3.42.0 and later, a negative
    6642
    ** argument passed into sqlite3_sleep() is changed to zero before it is relayed
    6643
    ** down into the xSleep method of the VFS.
    6644
    */
    6645
    SQLITE_API int sqlite3_sleep(int);
    6646
    6647
    /*
    6648
    ** CAPI3REF: Name Of The Folder Holding Temporary Files
    6649
    **
    6650
    ** ^(If this global variable is made to point to a string which is
    6651
    ** the name of a folder (a.k.a. directory), then all temporary files
    6652
    ** created by SQLite when using a built-in [sqlite3_vfs | VFS]
    6653
    ** will be placed in that directory.)^  ^If this variable
    6654
    ** is a NULL pointer, then SQLite performs a search for an appropriate
    6655
    ** temporary file directory.
    6656
    **
    6657
    ** Applications are strongly discouraged from using this global variable.
    6658
    ** It is required to set a temporary folder on Windows Runtime (WinRT).
    6659
    ** But for all other platforms, it is highly recommended that applications
    6660
    ** neither read nor write this variable.  This global variable is a relic
    6661
    ** that exists for backwards compatibility of legacy applications and should
    6662
    ** be avoided in new projects.
    6663
    **
    6664
    ** It is not safe to read or modify this variable in more than one
    6665
    ** thread at a time.  It is not safe to read or modify this variable
    6666
    ** if a [database connection] is being used at the same time in a separate
    6667
    ** thread.
    6668
    ** It is intended that this variable be set once
    6669
    ** as part of process initialization and before any SQLite interface
    6670
    ** routines have been called and that this variable remain unchanged
    6671
    ** thereafter.
    6672
    **
    6673
    ** ^The [temp_store_directory pragma] may modify this variable and cause
    6674
    ** it to point to memory obtained from [sqlite3_malloc].  ^Furthermore,
    6675
    ** the [temp_store_directory pragma] always assumes that any string
    6676
    ** that this variable points to is held in memory obtained from
    6677
    ** [sqlite3_malloc] and the pragma may attempt to free that memory
    6678
    ** using [sqlite3_free].
    6679
    ** Hence, if this variable is modified directly, either it should be
    6680
    ** made NULL or made to point to memory obtained from [sqlite3_malloc]
    6681
    ** or else the use of the [temp_store_directory pragma] should be avoided.
    6682
    ** Except when requested by the [temp_store_directory pragma], SQLite
    6683
    ** does not free the memory that sqlite3_temp_directory points to.  If
    6684
    ** the application wants that memory to be freed, it must do
    6685
    ** so itself, taking care to only do so after all [database connection]
    6686
    ** objects have been destroyed.
    6687
    **
    6688
    ** <b>Note to Windows Runtime users:</b>  The temporary directory must be set
    6689
    ** prior to calling [sqlite3_open] or [sqlite3_open_v2].  Otherwise, various
    6690
    ** features that require the use of temporary files may fail.  Here is an
    6691
    ** example of how to do this using C++ with the Windows Runtime:
    6692
    **
    6693
    ** <blockquote><pre>
    6694
    ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current->
    6695
    ** &nbsp;     TemporaryFolder->Path->Data();
    6696
    ** char zPathBuf&#91;MAX_PATH + 1&#93;;
    6697
    ** memset(zPathBuf, 0, sizeof(zPathBuf));
    6698
    ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf),
    6699
    ** &nbsp;     NULL, NULL);
    6700
    ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf);
    6701
    ** </pre></blockquote>
    6702
    */
    6703
    SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory;
    6704
    6705
    /*
    6706
    ** CAPI3REF: Name Of The Folder Holding Database Files
    6707
    **
    6708
    ** ^(If this global variable is made to point to a string which is
    6709
    ** the name of a folder (a.k.a. directory), then all database files
    6710
    ** specified with a relative pathname and created or accessed by
    6711
    ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed
    6712
    ** to be relative to that directory.)^ ^If this variable is a NULL
    6713
    ** pointer, then SQLite assumes that all database files specified
    6714
    ** with a relative pathname are relative to the current directory
    6715
    ** for the process.  Only the windows VFS makes use of this global
    6716
    ** variable; it is ignored by the unix VFS.
    6717
    **
    6718
    ** Changing the value of this variable while a database connection is
    6719
    ** open can result in a corrupt database.
    6720
    **
    6721
    ** It is not safe to read or modify this variable in more than one
    6722
    ** thread at a time.  It is not safe to read or modify this variable
    6723
    ** if a [database connection] is being used at the same time in a separate
    6724
    ** thread.
    6725
    ** It is intended that this variable be set once
    6726
    ** as part of process initialization and before any SQLite interface
    6727
    ** routines have been called and that this variable remain unchanged
    6728
    ** thereafter.
    6729
    **
    6730
    ** ^The [data_store_directory pragma] may modify this variable and cause
    6731
    ** it to point to memory obtained from [sqlite3_malloc].  ^Furthermore,
    6732
    ** the [data_store_directory pragma] always assumes that any string
    6733
    ** that this variable points to is held in memory obtained from
    6734
    ** [sqlite3_malloc] and the pragma may attempt to free that memory
    6735
    ** using [sqlite3_free].
    6736
    ** Hence, if this variable is modified directly, either it should be
    6737
    ** made NULL or made to point to memory obtained from [sqlite3_malloc]
    6738
    ** or else the use of the [data_store_directory pragma] should be avoided.
    6739
    */
    6740
    SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory;
    6741
    6742
    /*
    6743
    ** CAPI3REF: Win32 Specific Interface
    6744
    **
    6745
    ** These interfaces are available only on Windows.  The
    6746
    ** [sqlite3_win32_set_directory] interface is used to set the value associated
    6747
    ** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to
    6748
    ** zValue, depending on the value of the type parameter.  The zValue parameter
    6749
    ** should be NULL to cause the previous value to be freed via [sqlite3_free];
    6750
    ** a non-NULL value will be copied into memory obtained from [sqlite3_malloc]
    6751
    ** prior to being used.  The [sqlite3_win32_set_directory] interface returns
    6752
    ** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported,
    6753
    ** or [SQLITE_NOMEM] if memory could not be allocated.  The value of the
    6754
    ** [sqlite3_data_directory] variable is intended to act as a replacement for
    6755
    ** the current directory on the sub-platforms of Win32 where that concept is
    6756
    ** not present, e.g. WinRT and UWP.  The [sqlite3_win32_set_directory8] and
    6757
    ** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the
    6758
    ** sqlite3_win32_set_directory interface except the string parameter must be
    6759
    ** UTF-8 or UTF-16, respectively.
    6760
    */
    6761
    SQLITE_API int sqlite3_win32_set_directory(
    6762
      unsigned long type, /* Identifier for directory being set or reset */
    6763
      void *zValue        /* New value for directory being set or reset */
    6764
    );
    6765
    SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue);
    6766
    SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue);
    6767
    6768
    /*
    6769
    ** CAPI3REF: Win32 Directory Types
    6770
    **
    6771
    ** These macros are only available on Windows.  They define the allowed values
    6772
    ** for the type argument to the [sqlite3_win32_set_directory] interface.
    6773
    */
    6774
    #define SQLITE_WIN32_DATA_DIRECTORY_TYPE  1
    6775
    #define SQLITE_WIN32_TEMP_DIRECTORY_TYPE  2
    6776
    6777
    /*
    6778
    ** CAPI3REF: Test For Auto-Commit Mode
    6779
    ** KEYWORDS: {autocommit mode}
    6780
    ** METHOD: sqlite3
    6781
    **
    6782
    ** ^The sqlite3_get_autocommit() interface returns non-zero or
    6783
    ** zero if the given database connection is or is not in autocommit mode,
    6784
    ** respectively.  ^Autocommit mode is on by default.
    6785
    ** ^Autocommit mode is disabled by a [BEGIN] statement.
    6786
    ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
    6787
    **
    6788
    ** If certain kinds of errors occur on a statement within a multi-statement
    6789
    ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
    6790
    ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
    6791
    ** transaction might be rolled back automatically.  The only way to
    6792
    ** find out whether SQLite automatically rolled back the transaction after
    6793
    ** an error is to use this function.
    6794
    **
    6795
    ** If another thread changes the autocommit status of the database
    6796
    ** connection while this routine is running, then the return value
    6797
    ** is undefined.
    6798
    */
    6799
    SQLITE_API int sqlite3_get_autocommit(sqlite3*);
    6800
    6801
    /*
    6802
    ** CAPI3REF: Find The Database Handle Of A Prepared Statement
    6803
    ** METHOD: sqlite3_stmt
    6804
    **
    6805
    ** ^The sqlite3_db_handle interface returns the [database connection] handle
    6806
    ** to which a [prepared statement] belongs.  ^The [database connection]
    6807
    ** returned by sqlite3_db_handle is the same [database connection]
    6808
    ** that was the first argument
    6809
    ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
    6810
    ** create the statement in the first place.
    6811
    */
    6812
    SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
    6813
    6814
    /*
    6815
    ** CAPI3REF: Return The Schema Name For A Database Connection
    6816
    ** METHOD: sqlite3
    6817
    **
    6818
    ** ^The sqlite3_db_name(D,N) interface returns a pointer to the schema name
    6819
    ** for the N-th database on database connection D, or a NULL pointer if N is
    6820
    ** out of range.  An N value of 0 means the main database file.  An N of 1 is
    6821
    ** the "temp" schema.  Larger values of N correspond to various ATTACH-ed
    6822
    ** databases.
    6823
    **
    6824
    ** Space to hold the string that is returned by sqlite3_db_name() is managed
    6825
    ** by SQLite itself.  The string might be deallocated by any operation that
    6826
    ** changes the schema, including [ATTACH] or [DETACH] or calls to
    6827
    ** [sqlite3_serialize()] or [sqlite3_deserialize()], even operations that
    6828
    ** occur on a different thread.  Applications that need to
    6829
    ** remember the string long-term should make their own copy.  Applications that
    6830
    ** are accessing the same database connection simultaneously on multiple
    6831
    ** threads should mutex-protect calls to this API and should make their own
    6832
    ** private copy of the result prior to releasing the mutex.
    6833
    */
    6834
    SQLITE_API const char *sqlite3_db_name(sqlite3 *db, int N);
    6835
    6836
    /*
    6837
    ** CAPI3REF: Return The Filename For A Database Connection
    6838
    ** METHOD: sqlite3
    6839
    **
    6840
    ** ^The sqlite3_db_filename(D,N) interface returns a pointer to the filename
    6841
    ** associated with database N of connection D.
    6842
    ** ^If there is no attached database N on the database
    6843
    ** connection D, or if database N is a temporary or in-memory database, then
    6844
    ** this function will return either a NULL pointer or an empty string.
    6845
    **
    6846
    ** ^The string value returned by this routine is owned and managed by
    6847
    ** the database connection.  ^The value will be valid until the database N
    6848
    ** is [DETACH]-ed or until the database connection closes.
    6849
    **
    6850
    ** ^The filename returned by this function is the output of the
    6851
    ** xFullPathname method of the [VFS].  ^In other words, the filename
    6852
    ** will be an absolute pathname, even if the filename used
    6853
    ** to open the database originally was a URI or relative pathname.
    6854
    **
    6855
    ** If the filename pointer returned by this routine is not NULL, then it
    6856
    ** can be used as the filename input parameter to these routines:
    6857
    ** <ul>
    6858
    ** <li> [sqlite3_uri_parameter()]
    6859
    ** <li> [sqlite3_uri_boolean()]
    6860
    ** <li> [sqlite3_uri_int64()]
    6861
    ** <li> [sqlite3_filename_database()]
    6862
    ** <li> [sqlite3_filename_journal()]
    6863
    ** <li> [sqlite3_filename_wal()]
    6864
    ** </ul>
    6865
    */
    6866
    SQLITE_API sqlite3_filename sqlite3_db_filename(sqlite3 *db, const char *zDbName);
    6867
    6868
    /*
    6869
    ** CAPI3REF: Determine if a database is read-only
    6870
    ** METHOD: sqlite3
    6871
    **
    6872
    ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N
    6873
    ** of connection D is read-only, 0 if it is read/write, or -1 if N is not
    6874
    ** the name of a database on connection D.
    6875
    */
    6876
    SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName);
    6877
    6878
    /*
    6879
    ** CAPI3REF: Determine the transaction state of a database
    6880
    ** METHOD: sqlite3
    6881
    **
    6882
    ** ^The sqlite3_txn_state(D,S) interface returns the current
    6883
    ** [transaction state] of schema S in database connection D.  ^If S is NULL,
    6884
    ** then the highest transaction state of any schema on database connection D
    6885
    ** is returned.  Transaction states are (in order of lowest to highest):
    6886
    ** <ol>
    6887
    ** <li value="0"> SQLITE_TXN_NONE
    6888
    ** <li value="1"> SQLITE_TXN_READ
    6889
    ** <li value="2"> SQLITE_TXN_WRITE
    6890
    ** </ol>
    6891
    ** ^If the S argument to sqlite3_txn_state(D,S) is not the name of
    6892
    ** a valid schema, then -1 is returned.
    6893
    */
    6894
    SQLITE_API int sqlite3_txn_state(sqlite3*,const char *zSchema);
    6895
    6896
    /*
    6897
    ** CAPI3REF: Allowed return values from sqlite3_txn_state()
    6898
    ** KEYWORDS: {transaction state}
    6899
    **
    6900
    ** These constants define the current transaction state of a database file.
    6901
    ** ^The [sqlite3_txn_state(D,S)] interface returns one of these
    6902
    ** constants in order to describe the transaction state of schema S
    6903
    ** in [database connection] D.
    6904
    **
    6905
    ** <dl>
    6906
    ** [[SQLITE_TXN_NONE]] <dt>SQLITE_TXN_NONE</dt>
    6907
    ** <dd>The SQLITE_TXN_NONE state means that no transaction is currently
    6908
    ** pending.</dd>
    6909
    **
    6910
    ** [[SQLITE_TXN_READ]] <dt>SQLITE_TXN_READ</dt>
    6911
    ** <dd>The SQLITE_TXN_READ state means that the database is currently
    6912
    ** in a read transaction.  Content has been read from the database file
    6913
    ** but nothing in the database file has changed.  The transaction state
    6914
    ** will be advanced to SQLITE_TXN_WRITE if any changes occur and there are
    6915
    ** no other conflicting concurrent write transactions.  The transaction
    6916
    ** state will revert to SQLITE_TXN_NONE following a [ROLLBACK] or
    6917
    ** [COMMIT].</dd>
    6918
    **
    6919
    ** [[SQLITE_TXN_WRITE]] <dt>SQLITE_TXN_WRITE</dt>
    6920
    ** <dd>The SQLITE_TXN_WRITE state means that the database is currently
    6921
    ** in a write transaction.  Content has been written to the database file
    6922
    ** but has not yet committed.  The transaction state will change to
    6923
    ** SQLITE_TXN_NONE at the next [ROLLBACK] or [COMMIT].</dd>
    6924
    */
    6925
    #define SQLITE_TXN_NONE  0
    6926
    #define SQLITE_TXN_READ  1
    6927
    #define SQLITE_TXN_WRITE 2
    6928
    6929
    /*
    6930
    ** CAPI3REF: Find the next prepared statement
    6931
    ** METHOD: sqlite3
    6932
    **
    6933
    ** ^This interface returns a pointer to the next [prepared statement] after
    6934
    ** pStmt associated with the [database connection] pDb.  ^If pStmt is NULL
    6935
    ** then this interface returns a pointer to the first prepared statement
    6936
    ** associated with the database connection pDb.  ^If no prepared statement
    6937
    ** satisfies the conditions of this routine, it returns NULL.
    6938
    **
    6939
    ** The [database connection] pointer D in a call to
    6940
    ** [sqlite3_next_stmt(D,S)] must refer to an open database
    6941
    ** connection and in particular must not be a NULL pointer.
    6942
    */
    6943
    SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);
    6944
    6945
    /*
    6946
    ** CAPI3REF: Commit And Rollback Notification Callbacks
    6947
    ** METHOD: sqlite3
    6948
    **
    6949
    ** ^The sqlite3_commit_hook() interface registers a callback
    6950
    ** function to be invoked whenever a transaction is [COMMIT | committed].
    6951
    ** ^Any callback set by a previous call to sqlite3_commit_hook()
    6952
    ** for the same database connection is overridden.
    6953
    ** ^The sqlite3_rollback_hook() interface registers a callback
    6954
    ** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
    6955
    ** ^Any callback set by a previous call to sqlite3_rollback_hook()
    6956
    ** for the same database connection is overridden.
    6957
    ** ^The pArg argument is passed through to the callback.
    6958
    ** ^If the callback on a commit hook function returns non-zero,
    6959
    ** then the commit is converted into a rollback.
    6960
    **
    6961
    ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
    6962
    ** return the P argument from the previous call of the same function
    6963
    ** on the same [database connection] D, or NULL for
    6964
    ** the first call for each function on D.
    6965
    **
    6966
    ** The commit and rollback hook callbacks are not reentrant.
    6967
    ** The callback implementation must not do anything that will modify
    6968
    ** the database connection that invoked the callback.  Any actions
    6969
    ** to modify the database connection must be deferred until after the
    6970
    ** completion of the [sqlite3_step()] call that triggered the commit
    6971
    ** or rollback hook in the first place.
    6972
    ** Note that running any other SQL statements, including SELECT statements,
    6973
    ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify
    6974
    ** the database connections for the meaning of "modify" in this paragraph.
    6975
    **
    6976
    ** ^Registering a NULL function disables the callback.
    6977
    **
    6978
    ** ^When the commit hook callback routine returns zero, the [COMMIT]
    6979
    ** operation is allowed to continue normally.  ^If the commit hook
    6980
    ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
    6981
    ** ^The rollback hook is invoked on a rollback that results from a commit
    6982
    ** hook returning non-zero, just as it would be with any other rollback.
    6983
    **
    6984
    ** ^For the purposes of this API, a transaction is said to have been
    6985
    ** rolled back if an explicit "ROLLBACK" statement is executed, or
    6986
    ** an error or constraint causes an implicit rollback to occur.
    6987
    ** ^The rollback callback is not invoked if a transaction is
    6988
    ** automatically rolled back because the database connection is closed.
    6989
    **
    6990
    ** See also the [sqlite3_update_hook()] interface.
    6991
    */
    6992
    SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
    6993
    SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
    6994
    6995
    /*
    6996
    ** CAPI3REF: Autovacuum Compaction Amount Callback
    6997
    ** METHOD: sqlite3
    6998
    **
    6999
    ** ^The sqlite3_autovacuum_pages(D,C,P,X) interface registers a callback
    7000
    ** function C that is invoked prior to each autovacuum of the database
    7001
    ** file.  ^The callback is passed a copy of the generic data pointer (P),
    7002
    ** the schema-name of the attached database that is being autovacuumed,
    7003
    ** the size of the database file in pages, the number of free pages,
    7004
    ** and the number of bytes per page, respectively.  The callback should
    7005
    ** return the number of free pages that should be removed by the
    7006
    ** autovacuum.  ^If the callback returns zero, then no autovacuum happens.
    7007
    ** ^If the value returned is greater than or equal to the number of
    7008
    ** free pages, then a complete autovacuum happens.
    7009
    **
    7010
    ** <p>^If there are multiple ATTACH-ed database files that are being
    7011
    ** modified as part of a transaction commit, then the autovacuum pages
    7012
    ** callback is invoked separately for each file.
    7013
    **
    7014
    ** <p><b>The callback is not reentrant.</b> The callback function should
    7015
    ** not attempt to invoke any other SQLite interface.  If it does, bad
    7016
    ** things may happen, including segmentation faults and corrupt database
    7017
    ** files.  The callback function should be a simple function that
    7018
    ** does some arithmetic on its input parameters and returns a result.
    7019
    **
    7020
    ** ^The X parameter to sqlite3_autovacuum_pages(D,C,P,X) is an optional
    7021
    ** destructor for the P parameter.  ^If X is not NULL, then X(P) is
    7022
    ** invoked whenever the database connection closes or when the callback
    7023
    ** is overwritten by another invocation of sqlite3_autovacuum_pages().
    7024
    **
    7025
    ** <p>^There is only one autovacuum pages callback per database connection.
    7026
    ** ^Each call to the sqlite3_autovacuum_pages() interface overrides all
    7027
    ** previous invocations for that database connection.  ^If the callback
    7028
    ** argument (C) to sqlite3_autovacuum_pages(D,C,P,X) is a NULL pointer,
    7029
    ** then the autovacuum steps callback is canceled.  The return value
    7030
    ** from sqlite3_autovacuum_pages() is normally SQLITE_OK, but might
    7031
    ** be some other error code if something goes wrong.  The current
    7032
    ** implementation will only return SQLITE_OK or SQLITE_MISUSE, but other
    7033
    ** return codes might be added in future releases.
    7034
    **
    7035
    ** <p>If no autovacuum pages callback is specified (the usual case) or
    7036
    ** a NULL pointer is provided for the callback,
    7037
    ** then the default behavior is to vacuum all free pages.  So, in other
    7038
    ** words, the default behavior is the same as if the callback function
    7039
    ** were something like this:
    7040
    **
    7041
    ** <blockquote><pre>
    7042
    ** &nbsp;   unsigned int demonstration_autovac_pages_callback(
    7043
    ** &nbsp;     void *pClientData,
    7044
    ** &nbsp;     const char *zSchema,
    7045
    ** &nbsp;     unsigned int nDbPage,
    7046
    ** &nbsp;     unsigned int nFreePage,
    7047
    ** &nbsp;     unsigned int nBytePerPage
    7048
    ** &nbsp;   ){
    7049
    ** &nbsp;     return nFreePage;
    7050
    ** &nbsp;   }
    7051
    ** </pre></blockquote>
    7052
    */
    7053
    SQLITE_API int sqlite3_autovacuum_pages(
    7054
      sqlite3 *db,
    7055
      unsigned int(*)(void*,const char*,unsigned int,unsigned int,unsigned int),
    7056
      void*,
    7057
      void(*)(void*)
    7058
    );
    7059
    7060
    7061
    /*
    7062
    ** CAPI3REF: Data Change Notification Callbacks
    7063
    ** METHOD: sqlite3
    7064
    **
    7065
    ** ^The sqlite3_update_hook() interface registers a callback function
    7066
    ** with the [database connection] identified by the first argument
    7067
    ** to be invoked whenever a row is updated, inserted or deleted in
    7068
    ** a [rowid table].
    7069
    ** ^Any callback set by a previous call to this function
    7070
    ** for the same database connection is overridden.
    7071
    **
    7072
    ** ^The second argument is a pointer to the function to invoke when a
    7073
    ** row is updated, inserted or deleted in a rowid table.
    7074
    ** ^The update hook is disabled by invoking sqlite3_update_hook()
    7075
    ** with a NULL pointer as the second parameter.
    7076
    ** ^The first argument to the callback is a copy of the third argument
    7077
    ** to sqlite3_update_hook().
    7078
    ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
    7079
    ** or [SQLITE_UPDATE], depending on the operation that caused the callback
    7080
    ** to be invoked.
    7081
    ** ^The third and fourth arguments to the callback contain pointers to the
    7082
    ** database and table name containing the affected row.
    7083
    ** ^The final callback parameter is the [rowid] of the row.
    7084
    ** ^In the case of an update, this is the [rowid] after the update takes place.
    7085
    **
    7086
    ** ^(The update hook is not invoked when internal system tables are
    7087
    ** modified (i.e. sqlite_sequence).)^
    7088
    ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified.
    7089
    **
    7090
    ** ^In the current implementation, the update hook
    7091
    ** is not invoked when conflicting rows are deleted because of an
    7092
    ** [ON CONFLICT | ON CONFLICT REPLACE] clause.  ^Nor is the update hook
    7093
    ** invoked when rows are deleted using the [truncate optimization].
    7094
    ** The exceptions defined in this paragraph might change in a future
    7095
    ** release of SQLite.
    7096
    **
    7097
    ** Whether the update hook is invoked before or after the
    7098
    ** corresponding change is currently unspecified and may differ
    7099
    ** depending on the type of change. Do not rely on the order of the
    7100
    ** hook call with regards to the final result of the operation which
    7101
    ** triggers the hook.
    7102
    **
    7103
    ** The update hook implementation must not do anything that will modify
    7104
    ** the database connection that invoked the update hook.  Any actions
    7105
    ** to modify the database connection must be deferred until after the
    7106
    ** completion of the [sqlite3_step()] call that triggered the update hook.
    7107
    ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
    7108
    ** database connections for the meaning of "modify" in this paragraph.
    7109
    **
    7110
    ** ^The sqlite3_update_hook(D,C,P) function
    7111
    ** returns the P argument from the previous call
    7112
    ** on the same [database connection] D, or NULL for
    7113
    ** the first call on D.
    7114
    **
    7115
    ** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()],
    7116
    ** and [sqlite3_preupdate_hook()] interfaces.
    7117
    */
    7118
    SQLITE_API void *sqlite3_update_hook(
    7119
      sqlite3*,
    7120
      void(*)(void *,int ,char const *,char const *,sqlite3_int64),
    7121
      void*
    7122
    );
    7123
    7124
    /*
    7125
    ** CAPI3REF: Enable Or Disable Shared Pager Cache
    7126
    **
    7127
    ** ^(This routine enables or disables the sharing of the database cache
    7128
    ** and schema data structures between [database connection | connections]
    7129
    ** to the same database. Sharing is enabled if the argument is true
    7130
    ** and disabled if the argument is false.)^
    7131
    **
    7132
    ** This interface is omitted if SQLite is compiled with
    7133
    ** [-DSQLITE_OMIT_SHARED_CACHE].  The [-DSQLITE_OMIT_SHARED_CACHE]
    7134
    ** compile-time option is recommended because the
    7135
    ** [use of shared cache mode is discouraged].
    7136
    **
    7137
    ** ^Cache sharing is enabled and disabled for an entire process.
    7138
    ** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]).
    7139
    ** In prior versions of SQLite,
    7140
    ** sharing was enabled or disabled for each thread separately.
    7141
    **
    7142
    ** ^(The cache sharing mode set by this interface effects all subsequent
    7143
    ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
    7144
    ** Existing database connections continue to use the sharing mode
    7145
    ** that was in effect at the time they were opened.)^
    7146
    **
    7147
    ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
    7148
    ** successfully.  An [error code] is returned otherwise.)^
    7149
    **
    7150
    ** ^Shared cache is disabled by default. It is recommended that it stay
    7151
    ** that way.  In other words, do not use this routine.  This interface
    7152
    ** continues to be provided for historical compatibility, but its use is
    7153
    ** discouraged.  Any use of shared cache is discouraged.  If shared cache
    7154
    ** must be used, it is recommended that shared cache only be enabled for
    7155
    ** individual database connections using the [sqlite3_open_v2()] interface
    7156
    ** with the [SQLITE_OPEN_SHAREDCACHE] flag.
    7157
    **
    7158
    ** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0
    7159
    ** and will always return SQLITE_MISUSE. On those systems,
    7160
    ** shared cache mode should be enabled per-database connection via
    7161
    ** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE].
    7162
    **
    7163
    ** This interface is threadsafe on processors where writing a
    7164
    ** 32-bit integer is atomic.
    7165
    **
    7166
    ** See Also:  [SQLite Shared-Cache Mode]
    7167
    */
    7168
    SQLITE_API int sqlite3_enable_shared_cache(int);
    7169
    7170
    /*
    7171
    ** CAPI3REF: Attempt To Free Heap Memory
    7172
    **
    7173
    ** ^The sqlite3_release_memory() interface attempts to free N bytes
    7174
    ** of heap memory by deallocating non-essential memory allocations
    7175
    ** held by the database library.   Memory used to cache database
    7176
    ** pages to improve performance is an example of non-essential memory.
    7177
    ** ^sqlite3_release_memory() returns the number of bytes actually freed,
    7178
    ** which might be more or less than the amount requested.
    7179
    ** ^The sqlite3_release_memory() routine is a no-op returning zero
    7180
    ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT].
    7181
    **
    7182
    ** See also: [sqlite3_db_release_memory()]
    7183
    */
    7184
    SQLITE_API int sqlite3_release_memory(int);
    7185
    7186
    /*
    7187
    ** CAPI3REF: Free Memory Used By A Database Connection
    7188
    ** METHOD: sqlite3
    7189
    **
    7190
    ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap
    7191
    ** memory as possible from database connection D. Unlike the
    7192
    ** [sqlite3_release_memory()] interface, this interface is in effect even
    7193
    ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is
    7194
    ** omitted.
    7195
    **
    7196
    ** See also: [sqlite3_release_memory()]
    7197
    */
    7198
    SQLITE_API int sqlite3_db_release_memory(sqlite3*);
    7199
    7200
    /*
    7201
    ** CAPI3REF: Impose A Limit On Heap Size
    7202
    **
    7203
    ** These interfaces impose limits on the amount of heap memory that will be
    7204
    ** used by all database connections within a single process.
    7205
    **
    7206
    ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the
    7207
    ** soft limit on the amount of heap memory that may be allocated by SQLite.
    7208
    ** ^SQLite strives to keep heap memory utilization below the soft heap
    7209
    ** limit by reducing the number of pages held in the page cache
    7210
    ** as heap memory usages approaches the limit.
    7211
    ** ^The soft heap limit is "soft" because even though SQLite strives to stay
    7212
    ** below the limit, it will exceed the limit rather than generate
    7213
    ** an [SQLITE_NOMEM] error.  In other words, the soft heap limit
    7214
    ** is advisory only.
    7215
    **
    7216
    ** ^The sqlite3_hard_heap_limit64(N) interface sets a hard upper bound of
    7217
    ** N bytes on the amount of memory that will be allocated.  ^The
    7218
    ** sqlite3_hard_heap_limit64(N) interface is similar to
    7219
    ** sqlite3_soft_heap_limit64(N) except that memory allocations will fail
    7220
    ** when the hard heap limit is reached.
    7221
    **
    7222
    ** ^The return value from both sqlite3_soft_heap_limit64() and
    7223
    ** sqlite3_hard_heap_limit64() is the size of
    7224
    ** the heap limit prior to the call, or negative in the case of an
    7225
    ** error.  ^If the argument N is negative
    7226
    ** then no change is made to the heap limit.  Hence, the current
    7227
    ** size of heap limits can be determined by invoking
    7228
    ** sqlite3_soft_heap_limit64(-1) or sqlite3_hard_heap_limit(-1).
    7229
    **
    7230
    ** ^Setting the heap limits to zero disables the heap limiter mechanism.
    7231
    **
    7232
    ** ^The soft heap limit may not be greater than the hard heap limit.
    7233
    ** ^If the hard heap limit is enabled and if sqlite3_soft_heap_limit(N)
    7234
    ** is invoked with a value of N that is greater than the hard heap limit,
    7235
    ** the soft heap limit is set to the value of the hard heap limit.
    7236
    ** ^The soft heap limit is automatically enabled whenever the hard heap
    7237
    ** limit is enabled. ^When sqlite3_hard_heap_limit64(N) is invoked and
    7238
    ** the soft heap limit is outside the range of 1..N, then the soft heap
    7239
    ** limit is set to N.  ^Invoking sqlite3_soft_heap_limit64(0) when the
    7240
    ** hard heap limit is enabled makes the soft heap limit equal to the
    7241
    ** hard heap limit.
    7242
    **
    7243
    ** The memory allocation limits can also be adjusted using
    7244
    ** [PRAGMA soft_heap_limit] and [PRAGMA hard_heap_limit].
    7245
    **
    7246
    ** ^(The heap limits are not enforced in the current implementation
    7247
    ** if one or more of following conditions are true:
    7248
    **
    7249
    ** <ul>
    7250
    ** <li> The limit value is set to zero.
    7251
    ** <li> Memory accounting is disabled using a combination of the
    7252
    **      [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and
    7253
    **      the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.
    7254
    ** <li> An alternative page cache implementation is specified using
    7255
    **      [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...).
    7256
    ** <li> The page cache allocates from its own memory pool supplied
    7257
    **      by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than
    7258
    **      from the heap.
    7259
    ** </ul>)^
    7260
    **
    7261
    ** The circumstances under which SQLite will enforce the heap limits may
    7262
    ** change in future releases of SQLite.
    7263
    */
    7264
    SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N);
    7265
    SQLITE_API sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 N);
    7266
    7267
    /*
    7268
    ** CAPI3REF: Deprecated Soft Heap Limit Interface
    7269
    ** DEPRECATED
    7270
    **
    7271
    ** This is a deprecated version of the [sqlite3_soft_heap_limit64()]
    7272
    ** interface.  This routine is provided for historical compatibility
    7273
    ** only.  All new applications should use the
    7274
    ** [sqlite3_soft_heap_limit64()] interface rather than this one.
    7275
    */
    7276
    SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N);
    7277
    7278
    7279
    /*
    7280
    ** CAPI3REF: Extract Metadata About A Column Of A Table
    7281
    ** METHOD: sqlite3
    7282
    **
    7283
    ** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns
    7284
    ** information about column C of table T in database D
    7285
    ** on [database connection] X.)^  ^The sqlite3_table_column_metadata()
    7286
    ** interface returns SQLITE_OK and fills in the non-NULL pointers in
    7287
    ** the final five arguments with appropriate values if the specified
    7288
    ** column exists.  ^The sqlite3_table_column_metadata() interface returns
    7289
    ** SQLITE_ERROR if the specified column does not exist.
    7290
    ** ^If the column-name parameter to sqlite3_table_column_metadata() is a
    7291
    ** NULL pointer, then this routine simply checks for the existence of the
    7292
    ** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it
    7293
    ** does not.  If the table name parameter T in a call to
    7294
    ** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is
    7295
    ** undefined behavior.
    7296
    **
    7297
    ** ^The column is identified by the second, third and fourth parameters to
    7298
    ** this function. ^(The second parameter is either the name of the database
    7299
    ** (i.e. "main", "temp", or an attached database) containing the specified
    7300
    ** table or NULL.)^ ^If it is NULL, then all attached databases are searched
    7301
    ** for the table using the same algorithm used by the database engine to
    7302
    ** resolve unqualified table references.
    7303
    **
    7304
    ** ^The third and fourth parameters to this function are the table and column
    7305
    ** name of the desired column, respectively.
    7306
    **
    7307
    ** ^Metadata is returned by writing to the memory locations passed as the 5th
    7308
    ** and subsequent parameters to this function. ^Any of these arguments may be
    7309
    ** NULL, in which case the corresponding element of metadata is omitted.
    7310
    **
    7311
    ** ^(<blockquote>
    7312
    ** <table border="1">
    7313
    ** <tr><th> Parameter <th> Output<br>Type <th>  Description
    7314
    **
    7315
    ** <tr><td> 5th <td> const char* <td> Data type
    7316
    ** <tr><td> 6th <td> const char* <td> Name of default collation sequence
    7317
    ** <tr><td> 7th <td> int         <td> True if column has a NOT NULL constraint
    7318
    ** <tr><td> 8th <td> int         <td> True if column is part of the PRIMARY KEY
    7319
    ** <tr><td> 9th <td> int         <td> True if column is [AUTOINCREMENT]
    7320
    ** </table>
    7321
    ** </blockquote>)^
    7322
    **
    7323
    ** ^The memory pointed to by the character pointers returned for the
    7324
    ** declaration type and collation sequence is valid until the next
    7325
    ** call to any SQLite API function.
    7326
    **
    7327
    ** ^If the specified table is actually a view, an [error code] is returned.
    7328
    **
    7329
    ** ^If the specified column is "rowid", "oid" or "_rowid_" and the table
    7330
    ** is not a [WITHOUT ROWID] table and an
    7331
    ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
    7332
    ** parameters are set for the explicitly declared column. ^(If there is no
    7333
    ** [INTEGER PRIMARY KEY] column, then the outputs
    7334
    ** for the [rowid] are set as follows:
    7335
    **
    7336
    ** <pre>
    7337
    **     data type: "INTEGER"
    7338
    **     collation sequence: "BINARY"
    7339
    **     not null: 0
    7340
    **     primary key: 1
    7341
    **     auto increment: 0
    7342
    ** </pre>)^
    7343
    **
    7344
    ** ^This function causes all database schemas to be read from disk and
    7345
    ** parsed, if that has not already been done, and returns an error if
    7346
    ** any errors are encountered while loading the schema.
    7347
    */
    7348
    SQLITE_API int sqlite3_table_column_metadata(
    7349
      sqlite3 *db,                /* Connection handle */
    7350
      const char *zDbName,        /* Database name or NULL */
    7351
      const char *zTableName,     /* Table name */
    7352
      const char *zColumnName,    /* Column name */
    7353
      char const **pzDataType,    /* OUTPUT: Declared data type */
    7354
      char const **pzCollSeq,     /* OUTPUT: Collation sequence name */
    7355
      int *pNotNull,              /* OUTPUT: True if NOT NULL constraint exists */
    7356
      int *pPrimaryKey,           /* OUTPUT: True if column part of PK */
    7357
      int *pAutoinc               /* OUTPUT: True if column is auto-increment */
    7358
    );
    7359
    7360
    /*
    7361
    ** CAPI3REF: Load An Extension
    7362
    ** METHOD: sqlite3
    7363
    **
    7364
    ** ^This interface loads an SQLite extension library from the named file.
    7365
    **
    7366
    ** ^The sqlite3_load_extension() interface attempts to load an
    7367
    ** [SQLite extension] library contained in the file zFile.  If
    7368
    ** the file cannot be loaded directly, attempts are made to load
    7369
    ** with various operating-system specific extensions added.
    7370
    ** So for example, if "samplelib" cannot be loaded, then names like
    7371
    ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might
    7372
    ** be tried also.
    7373
    **
    7374
    ** ^The entry point is zProc.
    7375
    ** ^(zProc may be 0, in which case SQLite will try to come up with an
    7376
    ** entry point name on its own.  It first tries "sqlite3_extension_init".
    7377
    ** If that does not work, it constructs a name "sqlite3_X_init" where
    7378
    ** X consists of the lower-case equivalent of all ASCII alphabetic
    7379
    ** characters in the filename from the last "/" to the first following
    7380
    ** "." and omitting any initial "lib".)^
    7381
    ** ^The sqlite3_load_extension() interface returns
    7382
    ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
    7383
    ** ^If an error occurs and pzErrMsg is not 0, then the
    7384
    ** [sqlite3_load_extension()] interface shall attempt to
    7385
    ** fill *pzErrMsg with error message text stored in memory
    7386
    ** obtained from [sqlite3_malloc()]. The calling function
    7387
    ** should free this memory by calling [sqlite3_free()].
    7388
    **
    7389
    ** ^Extension loading must be enabled using
    7390
    ** [sqlite3_enable_load_extension()] or
    7391
    ** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL)
    7392
    ** prior to calling this API,
    7393
    ** otherwise an error will be returned.
    7394
    **
    7395
    ** <b>Security warning:</b> It is recommended that the
    7396
    ** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this
    7397
    ** interface.  The use of the [sqlite3_enable_load_extension()] interface
    7398
    ** should be avoided.  This will keep the SQL function [load_extension()]
    7399
    ** disabled and prevent SQL injections from giving attackers
    7400
    ** access to extension loading capabilities.
    7401
    **
    7402
    ** See also the [load_extension() SQL function].
    7403
    */
    7404
    SQLITE_API int sqlite3_load_extension(
    7405
      sqlite3 *db,          /* Load the extension into this database connection */
    7406
      const char *zFile,    /* Name of the shared library containing extension */
    7407
      const char *zProc,    /* Entry point.  Derived from zFile if 0 */
    7408
      char **pzErrMsg       /* Put error message here if not 0 */
    7409
    );
    7410
    7411
    /*
    7412
    ** CAPI3REF: Enable Or Disable Extension Loading
    7413
    ** METHOD: sqlite3
    7414
    **
    7415
    ** ^So as not to open security holes in older applications that are
    7416
    ** unprepared to deal with [extension loading], and as a means of disabling
    7417
    ** [extension loading] while evaluating user-entered SQL, the following API
    7418
    ** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
    7419
    **
    7420
    ** ^Extension loading is off by default.
    7421
    ** ^Call the sqlite3_enable_load_extension() routine with onoff==1
    7422
    ** to turn extension loading on and call it with onoff==0 to turn
    7423
    ** it back off again.
    7424
    **
    7425
    ** ^This interface enables or disables both the C-API
    7426
    ** [sqlite3_load_extension()] and the SQL function [load_extension()].
    7427
    ** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..)
    7428
    ** to enable or disable only the C-API.)^
    7429
    **
    7430
    ** <b>Security warning:</b> It is recommended that extension loading
    7431
    ** be enabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method
    7432
    ** rather than this interface, so the [load_extension()] SQL function
    7433
    ** remains disabled. This will prevent SQL injections from giving attackers
    7434
    ** access to extension loading capabilities.
    7435
    */
    7436
    SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
    7437
    7438
    /*
    7439
    ** CAPI3REF: Automatically Load Statically Linked Extensions
    7440
    **
    7441
    ** ^This interface causes the xEntryPoint() function to be invoked for
    7442
    ** each new [database connection] that is created.  The idea here is that
    7443
    ** xEntryPoint() is the entry point for a statically linked [SQLite extension]
    7444
    ** that is to be automatically loaded into all new database connections.
    7445
    **
    7446
    ** ^(Even though the function prototype shows that xEntryPoint() takes
    7447
    ** no arguments and returns void, SQLite invokes xEntryPoint() with three
    7448
    ** arguments and expects an integer result as if the signature of the
    7449
    ** entry point were as follows:
    7450
    **
    7451
    ** <blockquote><pre>
    7452
    ** &nbsp;  int xEntryPoint(
    7453
    ** &nbsp;    sqlite3 *db,
    7454
    ** &nbsp;    const char **pzErrMsg,
    7455
    ** &nbsp;    const struct sqlite3_api_routines *pThunk
    7456
    ** &nbsp;  );
    7457
    ** </pre></blockquote>)^
    7458
    **
    7459
    ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg
    7460
    ** point to an appropriate error message (obtained from [sqlite3_mprintf()])
    7461
    ** and return an appropriate [error code].  ^SQLite ensures that *pzErrMsg
    7462
    ** is NULL before calling the xEntryPoint().  ^SQLite will invoke
    7463
    ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns.  ^If any
    7464
    ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()],
    7465
    ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail.
    7466
    **
    7467
    ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already
    7468
    ** on the list of automatic extensions is a harmless no-op. ^No entry point
    7469
    ** will be called more than once for each database connection that is opened.
    7470
    **
    7471
    ** See also: [sqlite3_reset_auto_extension()]
    7472
    ** and [sqlite3_cancel_auto_extension()]
    7473
    */
    7474
    SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void));
    7475
    7476
    /*
    7477
    ** CAPI3REF: Cancel Automatic Extension Loading
    7478
    **
    7479
    ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the
    7480
    ** initialization routine X that was registered using a prior call to
    7481
    ** [sqlite3_auto_extension(X)].  ^The [sqlite3_cancel_auto_extension(X)]
    7482
    ** routine returns 1 if initialization routine X was successfully
    7483
    ** unregistered and it returns 0 if X was not on the list of initialization
    7484
    ** routines.
    7485
    */
    7486
    SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void));
    7487
    7488
    /*
    7489
    ** CAPI3REF: Reset Automatic Extension Loading
    7490
    **
    7491
    ** ^This interface disables all automatic extensions previously
    7492
    ** registered using [sqlite3_auto_extension()].
    7493
    */
    7494
    SQLITE_API void sqlite3_reset_auto_extension(void);
    7495
    7496
    /*
    7497
    ** Structures used by the virtual table interface
    7498
    */
    7499
    typedef struct sqlite3_vtab sqlite3_vtab;
    7500
    typedef struct sqlite3_index_info sqlite3_index_info;
    7501
    typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
    7502
    typedef struct sqlite3_module sqlite3_module;
    7503
    7504
    /*
    7505
    ** CAPI3REF: Virtual Table Object
    7506
    ** KEYWORDS: sqlite3_module {virtual table module}
    7507
    **
    7508
    ** This structure, sometimes called a "virtual table module",
    7509
    ** defines the implementation of a [virtual table].
    7510
    ** This structure consists mostly of methods for the module.
    7511
    **
    7512
    ** ^A virtual table module is created by filling in a persistent
    7513
    ** instance of this structure and passing a pointer to that instance
    7514
    ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
    7515
    ** ^The registration remains valid until it is replaced by a different
    7516
    ** module or until the [database connection] closes.  The content
    7517
    ** of this structure must not change while it is registered with
    7518
    ** any database connection.
    7519
    */
    7520
    struct sqlite3_module {
    7521
      int iVersion;
    7522
      int (*xCreate)(sqlite3*, void *pAux,
    7523
                   int argc, const char *const*argv,
    7524
                   sqlite3_vtab **ppVTab, char**);
    7525
      int (*xConnect)(sqlite3*, void *pAux,
    7526
                   int argc, const char *const*argv,
    7527
                   sqlite3_vtab **ppVTab, char**);
    7528
      int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
    7529
      int (*xDisconnect)(sqlite3_vtab *pVTab);
    7530
      int (*xDestroy)(sqlite3_vtab *pVTab);
    7531
      int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
    7532
      int (*xClose)(sqlite3_vtab_cursor*);
    7533
      int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
    7534
                    int argc, sqlite3_value **argv);
    7535
      int (*xNext)(sqlite3_vtab_cursor*);
    7536
      int (*xEof)(sqlite3_vtab_cursor*);
    7537
      int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
    7538
      int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
    7539
      int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
    7540
      int (*xBegin)(sqlite3_vtab *pVTab);
    7541
      int (*xSync)(sqlite3_vtab *pVTab);
    7542
      int (*xCommit)(sqlite3_vtab *pVTab);
    7543
      int (*xRollback)(sqlite3_vtab *pVTab);
    7544
      int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
    7545
                           void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
    7546
                           void **ppArg);
    7547
      int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
    7548
      /* The methods above are in version 1 of the sqlite_module object. Those
    7549
      ** below are for version 2 and greater. */
    7550
      int (*xSavepoint)(sqlite3_vtab *pVTab, int);
    7551
      int (*xRelease)(sqlite3_vtab *pVTab, int);
    7552
      int (*xRollbackTo)(sqlite3_vtab *pVTab, int);
    7553
      /* The methods above are in versions 1 and 2 of the sqlite_module object.
    7554
      ** Those below are for version 3 and greater. */
    7555
      int (*xShadowName)(const char*);
    7556
      /* The methods above are in versions 1 through 3 of the sqlite_module object.
    7557
      ** Those below are for version 4 and greater. */
    7558
      int (*xIntegrity)(sqlite3_vtab *pVTab, const char *zSchema,
    7559
                        const char *zTabName, int mFlags, char **pzErr);
    7560
    };
    7561
    7562
    /*
    7563
    ** CAPI3REF: Virtual Table Indexing Information
    7564
    ** KEYWORDS: sqlite3_index_info
    7565
    **
    7566
    ** The sqlite3_index_info structure and its substructures is used as part
    7567
    ** of the [virtual table] interface to
    7568
    ** pass information into and receive the reply from the [xBestIndex]
    7569
    ** method of a [virtual table module].  The fields under **Inputs** are the
    7570
    ** inputs to xBestIndex and are read-only.  xBestIndex inserts its
    7571
    ** results into the **Outputs** fields.
    7572
    **
    7573
    ** ^(The aConstraint[] array records WHERE clause constraints of the form:
    7574
    **
    7575
    ** <blockquote>column OP expr</blockquote>
    7576
    **
    7577
    ** where OP is =, &lt;, &lt;=, &gt;, or &gt;=.)^  ^(The particular operator is
    7578
    ** stored in aConstraint[].op using one of the
    7579
    ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^
    7580
    ** ^(The index of the column is stored in
    7581
    ** aConstraint[].iColumn.)^  ^(aConstraint[].usable is TRUE if the
    7582
    ** expr on the right-hand side can be evaluated (and thus the constraint
    7583
    ** is usable) and false if it cannot.)^
    7584
    **
    7585
    ** ^The optimizer automatically inverts terms of the form "expr OP column"
    7586
    ** and makes other simplifications to the WHERE clause in an attempt to
    7587
    ** get as many WHERE clause terms into the form shown above as possible.
    7588
    ** ^The aConstraint[] array only reports WHERE clause terms that are
    7589
    ** relevant to the particular virtual table being queried.
    7590
    **
    7591
    ** ^Information about the ORDER BY clause is stored in aOrderBy[].
    7592
    ** ^Each term of aOrderBy records a column of the ORDER BY clause.
    7593
    **
    7594
    ** The colUsed field indicates which columns of the virtual table may be
    7595
    ** required by the current scan. Virtual table columns are numbered from
    7596
    ** zero in the order in which they appear within the CREATE TABLE statement
    7597
    ** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62),
    7598
    ** the corresponding bit is set within the colUsed mask if the column may be
    7599
    ** required by SQLite. If the table has at least 64 columns and any column
    7600
    ** to the right of the first 63 is required, then bit 63 of colUsed is also
    7601
    ** set. In other words, column iCol may be required if the expression
    7602
    ** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to
    7603
    ** non-zero.
    7604
    **
    7605
    ** The [xBestIndex] method must fill aConstraintUsage[] with information
    7606
    ** about what parameters to pass to xFilter.  ^If argvIndex>0 then
    7607
    ** the right-hand side of the corresponding aConstraint[] is evaluated
    7608
    ** and becomes the argvIndex-th entry in argv.  ^(If aConstraintUsage[].omit
    7609
    ** is true, then the constraint is assumed to be fully handled by the
    7610
    ** virtual table and might not be checked again by the byte code.)^ ^(The
    7611
    ** aConstraintUsage[].omit flag is an optimization hint. When the omit flag
    7612
    ** is left in its default setting of false, the constraint will always be
    7613
    ** checked separately in byte code.  If the omit flag is changed to true, then
    7614
    ** the constraint may or may not be checked in byte code.  In other words,
    7615
    ** when the omit flag is true there is no guarantee that the constraint will
    7616
    ** not be checked again using byte code.)^
    7617
    **
    7618
    ** ^The idxNum and idxStr values are recorded and passed into the
    7619
    ** [xFilter] method.
    7620
    ** ^[sqlite3_free()] is used to free idxStr if and only if
    7621
    ** needToFreeIdxStr is true.
    7622
    **
    7623
    ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in
    7624
    ** the correct order to satisfy the ORDER BY clause so that no separate
    7625
    ** sorting step is required.
    7626
    **
    7627
    ** ^The estimatedCost value is an estimate of the cost of a particular
    7628
    ** strategy. A cost of N indicates that the cost of the strategy is similar
    7629
    ** to a linear scan of an SQLite table with N rows. A cost of log(N)
    7630
    ** indicates that the expense of the operation is similar to that of a
    7631
    ** binary search on a unique indexed field of an SQLite table with N rows.
    7632
    **
    7633
    ** ^The estimatedRows value is an estimate of the number of rows that
    7634
    ** will be returned by the strategy.
    7635
    **
    7636
    ** The xBestIndex method may optionally populate the idxFlags field with a
    7637
    ** mask of SQLITE_INDEX_SCAN_* flags. One such flag is
    7638
    ** [SQLITE_INDEX_SCAN_HEX], which if set causes the [EXPLAIN QUERY PLAN]
    7639
    ** output to show the idxNum as hex instead of as decimal.  Another flag is
    7640
    ** SQLITE_INDEX_SCAN_UNIQUE, which if set indicates that the query plan will
    7641
    ** return at most one row.
    7642
    **
    7643
    ** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then
    7644
    ** SQLite also assumes that if a call to the xUpdate() method is made as
    7645
    ** part of the same statement to delete or update a virtual table row and the
    7646
    ** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback
    7647
    ** any database changes. In other words, if the xUpdate() returns
    7648
    ** SQLITE_CONSTRAINT, the database contents must be exactly as they were
    7649
    ** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not
    7650
    ** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by
    7651
    ** the xUpdate method are automatically rolled back by SQLite.
    7652
    **
    7653
    ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info
    7654
    ** structure for SQLite [version 3.8.2] ([dateof:3.8.2]).
    7655
    ** If a virtual table extension is
    7656
    ** used with an SQLite version earlier than 3.8.2, the results of attempting
    7657
    ** to read or write the estimatedRows field are undefined (but are likely
    7658
    ** to include crashing the application). The estimatedRows field should
    7659
    ** therefore only be used if [sqlite3_libversion_number()] returns a
    7660
    ** value greater than or equal to 3008002. Similarly, the idxFlags field
    7661
    ** was added for [version 3.9.0] ([dateof:3.9.0]).
    7662
    ** It may therefore only be used if
    7663
    ** sqlite3_libversion_number() returns a value greater than or equal to
    7664
    ** 3009000.
    7665
    */
    7666
    struct sqlite3_index_info {
    7667
      /* Inputs */
    7668
      int nConstraint;           /* Number of entries in aConstraint */
    7669
      struct sqlite3_index_constraint {
    7670
         int iColumn;              /* Column constrained.  -1 for ROWID */
    7671
         unsigned char op;         /* Constraint operator */
    7672
         unsigned char usable;     /* True if this constraint is usable */
    7673
         int iTermOffset;          /* Used internally - xBestIndex should ignore */
    7674
      } *aConstraint;            /* Table of WHERE clause constraints */
    7675
      int nOrderBy;              /* Number of terms in the ORDER BY clause */
    7676
      struct sqlite3_index_orderby {
    7677
         int iColumn;              /* Column number */
    7678
         unsigned char desc;       /* True for DESC.  False for ASC. */
    7679
      } *aOrderBy;               /* The ORDER BY clause */
    7680
      /* Outputs */
    7681
      struct sqlite3_index_constraint_usage {
    7682
        int argvIndex;           /* if >0, constraint is part of argv to xFilter */
    7683
        unsigned char omit;      /* Do not code a test for this constraint */
    7684
      } *aConstraintUsage;
    7685
      int idxNum;                /* Number used to identify the index */
    7686
      char *idxStr;              /* String, possibly obtained from sqlite3_malloc */
    7687
      int needToFreeIdxStr;      /* Free idxStr using sqlite3_free() if true */
    7688
      int orderByConsumed;       /* True if output is already ordered */
    7689
      double estimatedCost;           /* Estimated cost of using this index */
    7690
      /* Fields below are only available in SQLite 3.8.2 and later */
    7691
      sqlite3_int64 estimatedRows;    /* Estimated number of rows returned */
    7692
      /* Fields below are only available in SQLite 3.9.0 and later */
    7693
      int idxFlags;              /* Mask of SQLITE_INDEX_SCAN_* flags */
    7694
      /* Fields below are only available in SQLite 3.10.0 and later */
    7695
      sqlite3_uint64 colUsed;    /* Input: Mask of columns used by statement */
    7696
    };
    7697
    7698
    /*
    7699
    ** CAPI3REF: Virtual Table Scan Flags
    7700
    **
    7701
    ** Virtual table implementations are allowed to set the
    7702
    ** [sqlite3_index_info].idxFlags field to some combination of
    7703
    ** these bits.
    7704
    */
    7705
    #define SQLITE_INDEX_SCAN_UNIQUE 0x00000001 /* Scan visits at most 1 row */
    7706
    #define SQLITE_INDEX_SCAN_HEX    0x00000002 /* Display idxNum as hex */
    7707
                                                /* in EXPLAIN QUERY PLAN */
    7708
    7709
    /*
    7710
    ** CAPI3REF: Virtual Table Constraint Operator Codes
    7711
    **
    7712
    ** These macros define the allowed values for the
    7713
    ** [sqlite3_index_info].aConstraint[].op field.  Each value represents
    7714
    ** an operator that is part of a constraint term in the WHERE clause of
    7715
    ** a query that uses a [virtual table].
    7716
    **
    7717
    ** ^The left-hand operand of the operator is given by the corresponding
    7718
    ** aConstraint[].iColumn field.  ^An iColumn of -1 indicates the left-hand
    7719
    ** operand is the rowid.
    7720
    ** The SQLITE_INDEX_CONSTRAINT_LIMIT and SQLITE_INDEX_CONSTRAINT_OFFSET
    7721
    ** operators have no left-hand operand, and so for those operators the
    7722
    ** corresponding aConstraint[].iColumn is meaningless and should not be
    7723
    ** used.
    7724
    **
    7725
    ** All operator values from SQLITE_INDEX_CONSTRAINT_FUNCTION through
    7726
    ** value 255 are reserved to represent functions that are overloaded
    7727
    ** by the [xFindFunction|xFindFunction method] of the virtual table
    7728
    ** implementation.
    7729
    **
    7730
    ** The right-hand operands for each constraint might be accessible using
    7731
    ** the [sqlite3_vtab_rhs_value()] interface.  Usually the right-hand
    7732
    ** operand is only available if it appears as a single constant literal
    7733
    ** in the input SQL.  If the right-hand operand is another column or an
    7734
    ** expression (even a constant expression) or a parameter, then the
    7735
    ** sqlite3_vtab_rhs_value() probably will not be able to extract it.
    7736
    ** ^The SQLITE_INDEX_CONSTRAINT_ISNULL and
    7737
    ** SQLITE_INDEX_CONSTRAINT_ISNOTNULL operators have no right-hand operand
    7738
    ** and hence calls to sqlite3_vtab_rhs_value() for those operators will
    7739
    ** always return SQLITE_NOTFOUND.
    7740
    **
    7741
    ** The collating sequence to be used for comparison can be found using
    7742
    ** the [sqlite3_vtab_collation()] interface.  For most real-world virtual
    7743
    ** tables, the collating sequence of constraints does not matter (for example
    7744
    ** because the constraints are numeric) and so the sqlite3_vtab_collation()
    7745
    ** interface is not commonly needed.
    7746
    */
    7747
    #define SQLITE_INDEX_CONSTRAINT_EQ          2
    7748
    #define SQLITE_INDEX_CONSTRAINT_GT          4
    7749
    #define SQLITE_INDEX_CONSTRAINT_LE          8
    7750
    #define SQLITE_INDEX_CONSTRAINT_LT         16
    7751
    #define SQLITE_INDEX_CONSTRAINT_GE         32
    7752
    #define SQLITE_INDEX_CONSTRAINT_MATCH      64
    7753
    #define SQLITE_INDEX_CONSTRAINT_LIKE       65
    7754
    #define SQLITE_INDEX_CONSTRAINT_GLOB       66
    7755
    #define SQLITE_INDEX_CONSTRAINT_REGEXP     67
    7756
    #define SQLITE_INDEX_CONSTRAINT_NE         68
    7757
    #define SQLITE_INDEX_CONSTRAINT_ISNOT      69
    7758
    #define SQLITE_INDEX_CONSTRAINT_ISNOTNULL  70
    7759
    #define SQLITE_INDEX_CONSTRAINT_ISNULL     71
    7760
    #define SQLITE_INDEX_CONSTRAINT_IS         72
    7761
    #define SQLITE_INDEX_CONSTRAINT_LIMIT      73
    7762
    #define SQLITE_INDEX_CONSTRAINT_OFFSET     74
    7763
    #define SQLITE_INDEX_CONSTRAINT_FUNCTION  150
    7764
    7765
    /*
    7766
    ** CAPI3REF: Register A Virtual Table Implementation
    7767
    ** METHOD: sqlite3
    7768
    **
    7769
    ** ^These routines are used to register a new [virtual table module] name.
    7770
    ** ^Module names must be registered before
    7771
    ** creating a new [virtual table] using the module and before using a
    7772
    ** preexisting [virtual table] for the module.
    7773
    **
    7774
    ** ^The module name is registered on the [database connection] specified
    7775
    ** by the first parameter.  ^The name of the module is given by the
    7776
    ** second parameter.  ^The third parameter is a pointer to
    7777
    ** the implementation of the [virtual table module].   ^The fourth
    7778
    ** parameter is an arbitrary client data pointer that is passed through
    7779
    ** into the [xCreate] and [xConnect] methods of the virtual table module
    7780
    ** when a new virtual table is being created or reinitialized.
    7781
    **
    7782
    ** ^The sqlite3_create_module_v2() interface has a fifth parameter which
    7783
    ** is a pointer to a destructor for the pClientData.  ^SQLite will
    7784
    ** invoke the destructor function (if it is not NULL) when SQLite
    7785
    ** no longer needs the pClientData pointer.  ^The destructor will also
    7786
    ** be invoked if the call to sqlite3_create_module_v2() fails.
    7787
    ** ^The sqlite3_create_module()
    7788
    ** interface is equivalent to sqlite3_create_module_v2() with a NULL
    7789
    ** destructor.
    7790
    **
    7791
    ** ^If the third parameter (the pointer to the sqlite3_module object) is
    7792
    ** NULL then no new module is created and any existing modules with the
    7793
    ** same name are dropped.
    7794
    **
    7795
    ** See also: [sqlite3_drop_modules()]
    7796
    */
    7797
    SQLITE_API int sqlite3_create_module(
    7798
      sqlite3 *db,               /* SQLite connection to register module with */
    7799
      const char *zName,         /* Name of the module */
    7800
      const sqlite3_module *p,   /* Methods for the module */
    7801
      void *pClientData          /* Client data for xCreate/xConnect */
    7802
    );
    7803
    SQLITE_API int sqlite3_create_module_v2(
    7804
      sqlite3 *db,               /* SQLite connection to register module with */
    7805
      const char *zName,         /* Name of the module */
    7806
      const sqlite3_module *p,   /* Methods for the module */
    7807
      void *pClientData,         /* Client data for xCreate/xConnect */
    7808
      void(*xDestroy)(void*)     /* Module destructor function */
    7809
    );
    7810
    7811
    /*
    7812
    ** CAPI3REF: Remove Unnecessary Virtual Table Implementations
    7813
    ** METHOD: sqlite3
    7814
    **
    7815
    ** ^The sqlite3_drop_modules(D,L) interface removes all virtual
    7816
    ** table modules from database connection D except those named on list L.
    7817
    ** The L parameter must be either NULL or a pointer to an array of pointers
    7818
    ** to strings where the array is terminated by a single NULL pointer.
    7819
    ** ^If the L parameter is NULL, then all virtual table modules are removed.
    7820
    **
    7821
    ** See also: [sqlite3_create_module()]
    7822
    */
    7823
    SQLITE_API int sqlite3_drop_modules(
    7824
      sqlite3 *db,                /* Remove modules from this connection */
    7825
      const char **azKeep         /* Except, do not remove the ones named here */
    7826
    );
    7827
    7828
    /*
    7829
    ** CAPI3REF: Virtual Table Instance Object
    7830
    ** KEYWORDS: sqlite3_vtab
    7831
    **
    7832
    ** Every [virtual table module] implementation uses a subclass
    7833
    ** of this object to describe a particular instance
    7834
    ** of the [virtual table].  Each subclass will
    7835
    ** be tailored to the specific needs of the module implementation.
    7836
    ** The purpose of this superclass is to define certain fields that are
    7837
    ** common to all module implementations.
    7838
    **
    7839
    ** ^Virtual tables methods can set an error message by assigning a
    7840
    ** string obtained from [sqlite3_mprintf()] to zErrMsg.  The method should
    7841
    ** take care that any prior string is freed by a call to [sqlite3_free()]
    7842
    ** prior to assigning a new string to zErrMsg.  ^After the error message
    7843
    ** is delivered up to the client application, the string will be automatically
    7844
    ** freed by sqlite3_free() and the zErrMsg field will be zeroed.
    7845
    */
    7846
    struct sqlite3_vtab {
    7847
      const sqlite3_module *pModule;  /* The module for this virtual table */
    7848
      int nRef;                       /* Number of open cursors */
    7849
      char *zErrMsg;                  /* Error message from sqlite3_mprintf() */
    7850
      /* Virtual table implementations will typically add additional fields */
    7851
    };
    7852
    7853
    /*
    7854
    ** CAPI3REF: Virtual Table Cursor Object
    7855
    ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
    7856
    **
    7857
    ** Every [virtual table module] implementation uses a subclass of the
    7858
    ** following structure to describe cursors that point into the
    7859
    ** [virtual table] and are used
    7860
    ** to loop through the virtual table.  Cursors are created using the
    7861
    ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
    7862
    ** by the [sqlite3_module.xClose | xClose] method.  Cursors are used
    7863
    ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
    7864
    ** of the module.  Each module implementation will define
    7865
    ** the content of a cursor structure to suit its own needs.
    7866
    **
    7867
    ** This superclass exists in order to define fields of the cursor that
    7868
    ** are common to all implementations.
    7869
    */
    7870
    struct sqlite3_vtab_cursor {
    7871
      sqlite3_vtab *pVtab;      /* Virtual table of this cursor */
    7872
      /* Virtual table implementations will typically add additional fields */
    7873
    };
    7874
    7875
    /*
    7876
    ** CAPI3REF: Declare The Schema Of A Virtual Table
    7877
    **
    7878
    ** ^The [xCreate] and [xConnect] methods of a
    7879
    ** [virtual table module] call this interface
    7880
    ** to declare the format (the names and datatypes of the columns) of
    7881
    ** the virtual tables they implement.
    7882
    */
    7883
    SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL);
    7884
    7885
    /*
    7886
    ** CAPI3REF: Overload A Function For A Virtual Table
    7887
    ** METHOD: sqlite3
    7888
    **
    7889
    ** ^(Virtual tables can provide alternative implementations of functions
    7890
    ** using the [xFindFunction] method of the [virtual table module].
    7891
    ** But global versions of those functions
    7892
    ** must exist in order to be overloaded.)^
    7893
    **
    7894
    ** ^(This API makes sure a global version of a function with a particular
    7895
    ** name and number of parameters exists.  If no such function exists
    7896
    ** before this API is called, a new function is created.)^  ^The implementation
    7897
    ** of the new function always causes an exception to be thrown.  So
    7898
    ** the new function is not good for anything by itself.  Its only
    7899
    ** purpose is to be a placeholder function that can be overloaded
    7900
    ** by a [virtual table].
    7901
    */
    7902
    SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
    7903
    7904
    /*
    7905
    ** CAPI3REF: A Handle To An Open BLOB
    7906
    ** KEYWORDS: {BLOB handle} {BLOB handles}
    7907
    **
    7908
    ** An instance of this object represents an open BLOB on which
    7909
    ** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
    7910
    ** ^Objects of this type are created by [sqlite3_blob_open()]
    7911
    ** and destroyed by [sqlite3_blob_close()].
    7912
    ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
    7913
    ** can be used to read or write small subsections of the BLOB.
    7914
    ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
    7915
    */
    7916
    typedef struct sqlite3_blob sqlite3_blob;
    7917
    7918
    /*
    7919
    ** CAPI3REF: Open A BLOB For Incremental I/O
    7920
    ** METHOD: sqlite3
    7921
    ** CONSTRUCTOR: sqlite3_blob
    7922
    **
    7923
    ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
    7924
    ** in row iRow, column zColumn, table zTable in database zDb;
    7925
    ** in other words, the same BLOB that would be selected by:
    7926
    **
    7927
    ** <pre>
    7928
    **     SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
    7929
    ** </pre>)^
    7930
    **
    7931
    ** ^(Parameter zDb is not the filename that contains the database, but
    7932
    ** rather the symbolic name of the database. For attached databases, this is
    7933
    ** the name that appears after the AS keyword in the [ATTACH] statement.
    7934
    ** For the main database file, the database name is "main". For TEMP
    7935
    ** tables, the database name is "temp".)^
    7936
    **
    7937
    ** ^If the flags parameter is non-zero, then the BLOB is opened for read
    7938
    ** and write access. ^If the flags parameter is zero, the BLOB is opened for
    7939
    ** read-only access.
    7940
    **
    7941
    ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored
    7942
    ** in *ppBlob. Otherwise an [error code] is returned and, unless the error
    7943
    ** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided
    7944
    ** the API is not misused, it is always safe to call [sqlite3_blob_close()]
    7945
    ** on *ppBlob after this function returns.
    7946
    **
    7947
    ** This function fails with SQLITE_ERROR if any of the following are true:
    7948
    ** <ul>
    7949
    **   <li> ^(Database zDb does not exist)^,
    7950
    **   <li> ^(Table zTable does not exist within database zDb)^,
    7951
    **   <li> ^(Table zTable is a WITHOUT ROWID table)^,
    7952
    **   <li> ^(Column zColumn does not exist)^,
    7953
    **   <li> ^(Row iRow is not present in the table)^,
    7954
    **   <li> ^(The specified column of row iRow contains a value that is not
    7955
    **         a TEXT or BLOB value)^,
    7956
    **   <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE
    7957
    **         constraint and the blob is being opened for read/write access)^,
    7958
    **   <li> ^([foreign key constraints | Foreign key constraints] are enabled,
    7959
    **         column zColumn is part of a [child key] definition and the blob is
    7960
    **         being opened for read/write access)^.
    7961
    ** </ul>
    7962
    **
    7963
    ** ^Unless it returns SQLITE_MISUSE, this function sets the
    7964
    ** [database connection] error code and message accessible via
    7965
    ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
    7966
    **
    7967
    ** A BLOB referenced by sqlite3_blob_open() may be read using the
    7968
    ** [sqlite3_blob_read()] interface and modified by using
    7969
    ** [sqlite3_blob_write()].  The [BLOB handle] can be moved to a
    7970
    ** different row of the same table using the [sqlite3_blob_reopen()]
    7971
    ** interface.  However, the column, table, or database of a [BLOB handle]
    7972
    ** cannot be changed after the [BLOB handle] is opened.
    7973
    **
    7974
    ** ^(If the row that a BLOB handle points to is modified by an
    7975
    ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
    7976
    ** then the BLOB handle is marked as "expired".
    7977
    ** This is true if any column of the row is changed, even a column
    7978
    ** other than the one the BLOB handle is open on.)^
    7979
    ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
    7980
    ** an expired BLOB handle fail with a return code of [SQLITE_ABORT].
    7981
    ** ^(Changes written into a BLOB prior to the BLOB expiring are not
    7982
    ** rolled back by the expiration of the BLOB.  Such changes will eventually
    7983
    ** commit if the transaction continues to completion.)^
    7984
    **
    7985
    ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
    7986
    ** the opened blob.  ^The size of a blob may not be changed by this
    7987
    ** interface.  Use the [UPDATE] SQL command to change the size of a
    7988
    ** blob.
    7989
    **
    7990
    ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
    7991
    ** and the built-in [zeroblob] SQL function may be used to create a
    7992
    ** zero-filled blob to read or write using the incremental-blob interface.
    7993
    **
    7994
    ** To avoid a resource leak, every open [BLOB handle] should eventually
    7995
    ** be released by a call to [sqlite3_blob_close()].
    7996
    **
    7997
    ** See also: [sqlite3_blob_close()],
    7998
    ** [sqlite3_blob_reopen()], [sqlite3_blob_read()],
    7999
    ** [sqlite3_blob_bytes()], [sqlite3_blob_write()].
    8000
    */
    8001
    SQLITE_API int sqlite3_blob_open(
    8002
      sqlite3*,
    8003
      const char *zDb,
    8004
      const char *zTable,
    8005
      const char *zColumn,
    8006
      sqlite3_int64 iRow,
    8007
      int flags,
    8008
      sqlite3_blob **ppBlob
    8009
    );
    8010
    8011
    /*
    8012
    ** CAPI3REF: Move a BLOB Handle to a New Row
    8013
    ** METHOD: sqlite3_blob
    8014
    **
    8015
    ** ^This function is used to move an existing [BLOB handle] so that it points
    8016
    ** to a different row of the same database table. ^The new row is identified
    8017
    ** by the rowid value passed as the second argument. Only the row can be
    8018
    ** changed. ^The database, table and column on which the blob handle is open
    8019
    ** remain the same. Moving an existing [BLOB handle] to a new row is
    8020
    ** faster than closing the existing handle and opening a new one.
    8021
    **
    8022
    ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -
    8023
    ** it must exist and there must be either a blob or text value stored in
    8024
    ** the nominated column.)^ ^If the new row is not present in the table, or if
    8025
    ** it does not contain a blob or text value, or if another error occurs, an
    8026
    ** SQLite error code is returned and the blob handle is considered aborted.
    8027
    ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or
    8028
    ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return
    8029
    ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle
    8030
    ** always returns zero.
    8031
    **
    8032
    ** ^This function sets the database handle error code and message.
    8033
    */
    8034
    SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);
    8035
    8036
    /*
    8037
    ** CAPI3REF: Close A BLOB Handle
    8038
    ** DESTRUCTOR: sqlite3_blob
    8039
    **
    8040
    ** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed
    8041
    ** unconditionally.  Even if this routine returns an error code, the
    8042
    ** handle is still closed.)^
    8043
    **
    8044
    ** ^If the blob handle being closed was opened for read-write access, and if
    8045
    ** the database is in auto-commit mode and there are no other open read-write
    8046
    ** blob handles or active write statements, the current transaction is
    8047
    ** committed. ^If an error occurs while committing the transaction, an error
    8048
    ** code is returned and the transaction rolled back.
    8049
    **
    8050
    ** Calling this function with an argument that is not a NULL pointer or an
    8051
    ** open blob handle results in undefined behavior. ^Calling this routine
    8052
    ** with a null pointer (such as would be returned by a failed call to
    8053
    ** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function
    8054
    ** is passed a valid open blob handle, the values returned by the
    8055
    ** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning.
    8056
    */
    8057
    SQLITE_API int sqlite3_blob_close(sqlite3_blob *);
    8058
    8059
    /*
    8060
    ** CAPI3REF: Return The Size Of An Open BLOB
    8061
    ** METHOD: sqlite3_blob
    8062
    **
    8063
    ** ^Returns the size in bytes of the BLOB accessible via the
    8064
    ** successfully opened [BLOB handle] in its only argument.  ^The
    8065
    ** incremental blob I/O routines can only read or overwrite existing
    8066
    ** blob content; they cannot change the size of a blob.
    8067
    **
    8068
    ** This routine only works on a [BLOB handle] which has been created
    8069
    ** by a prior successful call to [sqlite3_blob_open()] and which has not
    8070
    ** been closed by [sqlite3_blob_close()].  Passing any other pointer in
    8071
    ** to this routine results in undefined and probably undesirable behavior.
    8072
    */
    8073
    SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *);
    8074
    8075
    /*
    8076
    ** CAPI3REF: Read Data From A BLOB Incrementally
    8077
    ** METHOD: sqlite3_blob
    8078
    **
    8079
    ** ^(This function is used to read data from an open [BLOB handle] into a
    8080
    ** caller-supplied buffer. N bytes of data are copied into buffer Z
    8081
    ** from the open BLOB, starting at offset iOffset.)^
    8082
    **
    8083
    ** ^If offset iOffset is less than N bytes from the end of the BLOB,
    8084
    ** [SQLITE_ERROR] is returned and no data is read.  ^If N or iOffset is
    8085
    ** less than zero, [SQLITE_ERROR] is returned and no data is read.
    8086
    ** ^The size of the blob (and hence the maximum value of N+iOffset)
    8087
    ** can be determined using the [sqlite3_blob_bytes()] interface.
    8088
    **
    8089
    ** ^An attempt to read from an expired [BLOB handle] fails with an
    8090
    ** error code of [SQLITE_ABORT].
    8091
    **
    8092
    ** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
    8093
    ** Otherwise, an [error code] or an [extended error code] is returned.)^
    8094
    **
    8095
    ** This routine only works on a [BLOB handle] which has been created
    8096
    ** by a prior successful call to [sqlite3_blob_open()] and which has not
    8097
    ** been closed by [sqlite3_blob_close()].  Passing any other pointer in
    8098
    ** to this routine results in undefined and probably undesirable behavior.
    8099
    **
    8100
    ** See also: [sqlite3_blob_write()].
    8101
    */
    8102
    SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
    8103
    8104
    /*
    8105
    ** CAPI3REF: Write Data Into A BLOB Incrementally
    8106
    ** METHOD: sqlite3_blob
    8107
    **
    8108
    ** ^(This function is used to write data into an open [BLOB handle] from a
    8109
    ** caller-supplied buffer. N bytes of data are copied from the buffer Z
    8110
    ** into the open BLOB, starting at offset iOffset.)^
    8111
    **
    8112
    ** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
    8113
    ** Otherwise, an  [error code] or an [extended error code] is returned.)^
    8114
    ** ^Unless SQLITE_MISUSE is returned, this function sets the
    8115
    ** [database connection] error code and message accessible via
    8116
    ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
    8117
    **
    8118
    ** ^If the [BLOB handle] passed as the first argument was not opened for
    8119
    ** writing (the flags parameter to [sqlite3_blob_open()] was zero),
    8120
    ** this function returns [SQLITE_READONLY].
    8121
    **
    8122
    ** This function may only modify the contents of the BLOB; it is
    8123
    ** not possible to increase the size of a BLOB using this API.
    8124
    ** ^If offset iOffset is less than N bytes from the end of the BLOB,
    8125
    ** [SQLITE_ERROR] is returned and no data is written. The size of the
    8126
    ** BLOB (and hence the maximum value of N+iOffset) can be determined
    8127
    ** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less
    8128
    ** than zero [SQLITE_ERROR] is returned and no data is written.
    8129
    **
    8130
    ** ^An attempt to write to an expired [BLOB handle] fails with an
    8131
    ** error code of [SQLITE_ABORT].  ^Writes to the BLOB that occurred
    8132
    ** before the [BLOB handle] expired are not rolled back by the
    8133
    ** expiration of the handle, though of course those changes might
    8134
    ** have been overwritten by the statement that expired the BLOB handle
    8135
    ** or by other independent statements.
    8136
    **
    8137
    ** This routine only works on a [BLOB handle] which has been created
    8138
    ** by a prior successful call to [sqlite3_blob_open()] and which has not
    8139
    ** been closed by [sqlite3_blob_close()].  Passing any other pointer in
    8140
    ** to this routine results in undefined and probably undesirable behavior.
    8141
    **
    8142
    ** See also: [sqlite3_blob_read()].
    8143
    */
    8144
    SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
    8145
    8146
    /*
    8147
    ** CAPI3REF: Virtual File System Objects
    8148
    **
    8149
    ** A virtual filesystem (VFS) is an [sqlite3_vfs] object
    8150
    ** that SQLite uses to interact
    8151
    ** with the underlying operating system.  Most SQLite builds come with a
    8152
    ** single default VFS that is appropriate for the host computer.
    8153
    ** New VFSes can be registered and existing VFSes can be unregistered.
    8154
    ** The following interfaces are provided.
    8155
    **
    8156
    ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
    8157
    ** ^Names are case sensitive.
    8158
    ** ^Names are zero-terminated UTF-8 strings.
    8159
    ** ^If there is no match, a NULL pointer is returned.
    8160
    ** ^If zVfsName is NULL then the default VFS is returned.
    8161
    **
    8162
    ** ^New VFSes are registered with sqlite3_vfs_register().
    8163
    ** ^Each new VFS becomes the default VFS if the makeDflt flag is set.
    8164
    ** ^The same VFS can be registered multiple times without injury.
    8165
    ** ^To make an existing VFS into the default VFS, register it again
    8166
    ** with the makeDflt flag set.  If two different VFSes with the
    8167
    ** same name are registered, the behavior is undefined.  If a
    8168
    ** VFS is registered with a name that is NULL or an empty string,
    8169
    ** then the behavior is undefined.
    8170
    **
    8171
    ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.
    8172
    ** ^(If the default VFS is unregistered, another VFS is chosen as
    8173
    ** the default.  The choice for the new VFS is arbitrary.)^
    8174
    */
    8175
    SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
    8176
    SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
    8177
    SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);
    8178
    8179
    /*
    8180
    ** CAPI3REF: Mutexes
    8181
    **
    8182
    ** The SQLite core uses these routines for thread
    8183
    ** synchronization. Though they are intended for internal
    8184
    ** use by SQLite, code that links against SQLite is
    8185
    ** permitted to use any of these routines.
    8186
    **
    8187
    ** The SQLite source code contains multiple implementations
    8188
    ** of these mutex routines.  An appropriate implementation
    8189
    ** is selected automatically at compile-time.  The following
    8190
    ** implementations are available in the SQLite core:
    8191
    **
    8192
    ** <ul>
    8193
    ** <li>   SQLITE_MUTEX_PTHREADS
    8194
    ** <li>   SQLITE_MUTEX_W32
    8195
    ** <li>   SQLITE_MUTEX_NOOP
    8196
    ** </ul>
    8197
    **
    8198
    ** The SQLITE_MUTEX_NOOP implementation is a set of routines
    8199
    ** that does no real locking and is appropriate for use in
    8200
    ** a single-threaded application.  The SQLITE_MUTEX_PTHREADS and
    8201
    ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix
    8202
    ** and Windows.
    8203
    **
    8204
    ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
    8205
    ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
    8206
    ** implementation is included with the library. In this case the
    8207
    ** application must supply a custom mutex implementation using the
    8208
    ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
    8209
    ** before calling sqlite3_initialize() or any other public sqlite3_
    8210
    ** function that calls sqlite3_initialize().
    8211
    **
    8212
    ** ^The sqlite3_mutex_alloc() routine allocates a new
    8213
    ** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc()
    8214
    ** routine returns NULL if it is unable to allocate the requested
    8215
    ** mutex.  The argument to sqlite3_mutex_alloc() must be one of these
    8216
    ** integer constants:
    8217
    **
    8218
    ** <ul>
    8219
    ** <li>  SQLITE_MUTEX_FAST
    8220
    ** <li>  SQLITE_MUTEX_RECURSIVE
    8221
    ** <li>  SQLITE_MUTEX_STATIC_MAIN
    8222
    ** <li>  SQLITE_MUTEX_STATIC_MEM
    8223
    ** <li>  SQLITE_MUTEX_STATIC_OPEN
    8224
    ** <li>  SQLITE_MUTEX_STATIC_PRNG
    8225
    ** <li>  SQLITE_MUTEX_STATIC_LRU
    8226
    ** <li>  SQLITE_MUTEX_STATIC_PMEM
    8227
    ** <li>  SQLITE_MUTEX_STATIC_APP1
    8228
    ** <li>  SQLITE_MUTEX_STATIC_APP2
    8229
    ** <li>  SQLITE_MUTEX_STATIC_APP3
    8230
    ** <li>  SQLITE_MUTEX_STATIC_VFS1
    8231
    ** <li>  SQLITE_MUTEX_STATIC_VFS2
    8232
    ** <li>  SQLITE_MUTEX_STATIC_VFS3
    8233
    ** </ul>
    8234
    **
    8235
    ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
    8236
    ** cause sqlite3_mutex_alloc() to create
    8237
    ** a new mutex.  ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
    8238
    ** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
    8239
    ** The mutex implementation does not need to make a distinction
    8240
    ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
    8241
    ** not want to.  SQLite will only request a recursive mutex in
    8242
    ** cases where it really needs one.  If a faster non-recursive mutex
    8243
    ** implementation is available on the host platform, the mutex subsystem
    8244
    ** might return such a mutex in response to SQLITE_MUTEX_FAST.
    8245
    **
    8246
    ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
    8247
    ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
    8248
    ** a pointer to a static preexisting mutex.  ^Nine static mutexes are
    8249
    ** used by the current version of SQLite.  Future versions of SQLite
    8250
    ** may add additional static mutexes.  Static mutexes are for internal
    8251
    ** use by SQLite only.  Applications that use SQLite mutexes should
    8252
    ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
    8253
    ** SQLITE_MUTEX_RECURSIVE.
    8254
    **
    8255
    ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
    8256
    ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
    8257
    ** returns a different mutex on every call.  ^For the static
    8258
    ** mutex types, the same mutex is returned on every call that has
    8259
    ** the same type number.
    8260
    **
    8261
    ** ^The sqlite3_mutex_free() routine deallocates a previously
    8262
    ** allocated dynamic mutex.  Attempting to deallocate a static
    8263
    ** mutex results in undefined behavior.
    8264
    **
    8265
    ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
    8266
    ** to enter a mutex.  ^If another thread is already within the mutex,
    8267
    ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
    8268
    ** SQLITE_BUSY.  ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
    8269
    ** upon successful entry.  ^(Mutexes created using
    8270
    ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
    8271
    ** In such cases, the
    8272
    ** mutex must be exited an equal number of times before another thread
    8273
    ** can enter.)^  If the same thread tries to enter any mutex other
    8274
    ** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined.
    8275
    **
    8276
    ** ^(Some systems (for example, Windows 95) do not support the operation
    8277
    ** implemented by sqlite3_mutex_try().  On those systems, sqlite3_mutex_try()
    8278
    ** will always return SQLITE_BUSY. In most cases the SQLite core only uses
    8279
    ** sqlite3_mutex_try() as an optimization, so this is acceptable
    8280
    ** behavior. The exceptions are unix builds that set the
    8281
    ** SQLITE_ENABLE_SETLK_TIMEOUT build option. In that case a working
    8282
    ** sqlite3_mutex_try() is required.)^
    8283
    **
    8284
    ** ^The sqlite3_mutex_leave() routine exits a mutex that was
    8285
    ** previously entered by the same thread.   The behavior
    8286
    ** is undefined if the mutex is not currently entered by the
    8287
    ** calling thread or is not currently allocated.
    8288
    **
    8289
    ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(),
    8290
    ** sqlite3_mutex_leave(), or sqlite3_mutex_free() is a NULL pointer,
    8291
    ** then any of the four routines behaves as a no-op.
    8292
    **
    8293
    ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
    8294
    */
    8295
    SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int);
    8296
    SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*);
    8297
    SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*);
    8298
    SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*);
    8299
    SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*);
    8300
    8301
    /*
    8302
    ** CAPI3REF: Mutex Methods Object
    8303
    **
    8304
    ** An instance of this structure defines the low-level routines
    8305
    ** used to allocate and use mutexes.
    8306
    **
    8307
    ** Usually, the default mutex implementations provided by SQLite are
    8308
    ** sufficient, however the application has the option of substituting a custom
    8309
    ** implementation for specialized deployments or systems for which SQLite
    8310
    ** does not provide a suitable implementation. In this case, the application
    8311
    ** creates and populates an instance of this structure to pass
    8312
    ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
    8313
    ** Additionally, an instance of this structure can be used as an
    8314
    ** output variable when querying the system for the current mutex
    8315
    ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
    8316
    **
    8317
    ** ^The xMutexInit method defined by this structure is invoked as
    8318
    ** part of system initialization by the sqlite3_initialize() function.
    8319
    ** ^The xMutexInit routine is called by SQLite exactly once for each
    8320
    ** effective call to [sqlite3_initialize()].
    8321
    **
    8322
    ** ^The xMutexEnd method defined by this structure is invoked as
    8323
    ** part of system shutdown by the sqlite3_shutdown() function. The
    8324
    ** implementation of this method is expected to release all outstanding
    8325
    ** resources obtained by the mutex methods implementation, especially
    8326
    ** those obtained by the xMutexInit method.  ^The xMutexEnd()
    8327
    ** interface is invoked exactly once for each call to [sqlite3_shutdown()].
    8328
    **
    8329
    ** ^(The remaining seven methods defined by this structure (xMutexAlloc,
    8330
    ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
    8331
    ** xMutexNotheld) implement the following interfaces (respectively):
    8332
    **
    8333
    ** <ul>
    8334
    **   <li>  [sqlite3_mutex_alloc()] </li>
    8335
    **   <li>  [sqlite3_mutex_free()] </li>
    8336
    **   <li>  [sqlite3_mutex_enter()] </li>
    8337
    **   <li>  [sqlite3_mutex_try()] </li>
    8338
    **   <li>  [sqlite3_mutex_leave()] </li>
    8339
    **   <li>  [sqlite3_mutex_held()] </li>
    8340
    **   <li>  [sqlite3_mutex_notheld()] </li>
    8341
    ** </ul>)^
    8342
    **
    8343
    ** The only difference is that the public sqlite3_XXX functions enumerated
    8344
    ** above silently ignore any invocations that pass a NULL pointer instead
    8345
    ** of a valid mutex handle. The implementations of the methods defined
    8346
    ** by this structure are not required to handle this case. The results
    8347
    ** of passing a NULL pointer instead of a valid mutex handle are undefined
    8348
    ** (i.e. it is acceptable to provide an implementation that segfaults if
    8349
    ** it is passed a NULL pointer).
    8350
    **
    8351
    ** The xMutexInit() method must be threadsafe.  It must be harmless to
    8352
    ** invoke xMutexInit() multiple times within the same process and without
    8353
    ** intervening calls to xMutexEnd().  Second and subsequent calls to
    8354
    ** xMutexInit() must be no-ops.
    8355
    **
    8356
    ** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
    8357
    ** and its associates).  Similarly, xMutexAlloc() must not use SQLite memory
    8358
    ** allocation for a static mutex.  ^However xMutexAlloc() may use SQLite
    8359
    ** memory allocation for a fast or recursive mutex.
    8360
    **
    8361
    ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
    8362
    ** called, but only if the prior call to xMutexInit returned SQLITE_OK.
    8363
    ** If xMutexInit fails in any way, it is expected to clean up after itself
    8364
    ** prior to returning.
    8365
    */
    8366
    typedef struct sqlite3_mutex_methods sqlite3_mutex_methods;
    8367
    struct sqlite3_mutex_methods {
    8368
      int (*xMutexInit)(void);
    8369
      int (*xMutexEnd)(void);
    8370
      sqlite3_mutex *(*xMutexAlloc)(int);
    8371
      void (*xMutexFree)(sqlite3_mutex *);
    8372
      void (*xMutexEnter)(sqlite3_mutex *);
    8373
      int (*xMutexTry)(sqlite3_mutex *);
    8374
      void (*xMutexLeave)(sqlite3_mutex *);
    8375
      int (*xMutexHeld)(sqlite3_mutex *);
    8376
      int (*xMutexNotheld)(sqlite3_mutex *);
    8377
    };
    8378
    8379
    /*
    8380
    ** CAPI3REF: Mutex Verification Routines
    8381
    **
    8382
    ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
    8383
    ** are intended for use inside assert() statements.  The SQLite core
    8384
    ** never uses these routines except inside an assert() and applications
    8385
    ** are advised to follow the lead of the core.  The SQLite core only
    8386
    ** provides implementations for these routines when it is compiled
    8387
    ** with the SQLITE_DEBUG flag.  External mutex implementations
    8388
    ** are only required to provide these routines if SQLITE_DEBUG is
    8389
    ** defined and if NDEBUG is not defined.
    8390
    **
    8391
    ** These routines should return true if the mutex in their argument
    8392
    ** is held or not held, respectively, by the calling thread.
    8393
    **
    8394
    ** The implementation is not required to provide versions of these
    8395
    ** routines that actually work. If the implementation does not provide working
    8396
    ** versions of these routines, it should at least provide stubs that always
    8397
    ** return true so that one does not get spurious assertion failures.
    8398
    **
    8399
    ** If the argument to sqlite3_mutex_held() is a NULL pointer then
    8400
    ** the routine should return 1.   This seems counter-intuitive since
    8401
    ** clearly the mutex cannot be held if it does not exist.  But
    8402
    ** the reason the mutex does not exist is because the build is not
    8403
    ** using mutexes.  And we do not want the assert() containing the
    8404
    ** call to sqlite3_mutex_held() to fail, so a non-zero return is
    8405
    ** the appropriate thing to do.  The sqlite3_mutex_notheld()
    8406
    ** interface should also return 1 when given a NULL pointer.
    8407
    */
    8408
    #ifndef NDEBUG
    8409
    SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*);
    8410
    SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*);
    8411
    #endif
    8412
    8413
    /*
    8414
    ** CAPI3REF: Mutex Types
    8415
    **
    8416
    ** The [sqlite3_mutex_alloc()] interface takes a single argument
    8417
    ** which is one of these integer constants.
    8418
    **
    8419
    ** The set of static mutexes may change from one SQLite release to the
    8420
    ** next.  Applications that override the built-in mutex logic must be
    8421
    ** prepared to accommodate additional static mutexes.
    8422
    */
    8423
    #define SQLITE_MUTEX_FAST             0
    8424
    #define SQLITE_MUTEX_RECURSIVE        1
    8425
    #define SQLITE_MUTEX_STATIC_MAIN      2
    8426
    #define SQLITE_MUTEX_STATIC_MEM       3  /* sqlite3_malloc() */
    8427
    #define SQLITE_MUTEX_STATIC_MEM2      4  /* NOT USED */
    8428
    #define SQLITE_MUTEX_STATIC_OPEN      4  /* sqlite3BtreeOpen() */
    8429
    #define SQLITE_MUTEX_STATIC_PRNG      5  /* sqlite3_randomness() */
    8430
    #define SQLITE_MUTEX_STATIC_LRU       6  /* lru page list */
    8431
    #define SQLITE_MUTEX_STATIC_LRU2      7  /* NOT USED */
    8432
    #define SQLITE_MUTEX_STATIC_PMEM      7  /* sqlite3PageMalloc() */
    8433
    #define SQLITE_MUTEX_STATIC_APP1      8  /* For use by application */
    8434
    #define SQLITE_MUTEX_STATIC_APP2      9  /* For use by application */
    8435
    #define SQLITE_MUTEX_STATIC_APP3     10  /* For use by application */
    8436
    #define SQLITE_MUTEX_STATIC_VFS1     11  /* For use by built-in VFS */
    8437
    #define SQLITE_MUTEX_STATIC_VFS2     12  /* For use by extension VFS */
    8438
    #define SQLITE_MUTEX_STATIC_VFS3     13  /* For use by application VFS */
    8439
    8440
    /* Legacy compatibility: */
    8441
    #define SQLITE_MUTEX_STATIC_MASTER    2
    8442
    8443
    8444
    /*
    8445
    ** CAPI3REF: Retrieve the mutex for a database connection
    8446
    ** METHOD: sqlite3
    8447
    **
    8448
    ** ^This interface returns a pointer to the [sqlite3_mutex] object that
    8449
    ** serializes access to the [database connection] given in the argument
    8450
    ** when the [threading mode] is Serialized.
    8451
    ** ^If the [threading mode] is Single-thread or Multi-thread then this
    8452
    ** routine returns a NULL pointer.
    8453
    */
    8454
    SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*);
    8455
    8456
    /*
    8457
    ** CAPI3REF: Low-Level Control Of Database Files
    8458
    ** METHOD: sqlite3
    8459
    ** KEYWORDS: {file control}
    8460
    **
    8461
    ** ^The [sqlite3_file_control()] interface makes a direct call to the
    8462
    ** xFileControl method for the [sqlite3_io_methods] object associated
    8463
    ** with a particular database identified by the second argument. ^The
    8464
    ** name of the database is "main" for the main database or "temp" for the
    8465
    ** TEMP database, or the name that appears after the AS keyword for
    8466
    ** databases that are added using the [ATTACH] SQL command.
    8467
    ** ^A NULL pointer can be used in place of "main" to refer to the
    8468
    ** main database file.
    8469
    ** ^The third and fourth parameters to this routine
    8470
    ** are passed directly through to the second and third parameters of
    8471
    ** the xFileControl method.  ^The return value of the xFileControl
    8472
    ** method becomes the return value of this routine.
    8473
    **
    8474
    ** A few opcodes for [sqlite3_file_control()] are handled directly
    8475
    ** by the SQLite core and never invoke the
    8476
    ** sqlite3_io_methods.xFileControl method.
    8477
    ** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes
    8478
    ** a pointer to the underlying [sqlite3_file] object to be written into
    8479
    ** the space pointed to by the 4th parameter.  The
    8480
    ** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns
    8481
    ** the [sqlite3_file] object associated with the journal file instead of
    8482
    ** the main database.  The [SQLITE_FCNTL_VFS_POINTER] opcode returns
    8483
    ** a pointer to the underlying [sqlite3_vfs] object for the file.
    8484
    ** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter
    8485
    ** from the pager.
    8486
    **
    8487
    ** ^If the second parameter (zDbName) does not match the name of any
    8488
    ** open database file, then SQLITE_ERROR is returned.  ^This error
    8489
    ** code is not remembered and will not be recalled by [sqlite3_errcode()]
    8490
    ** or [sqlite3_errmsg()].  The underlying xFileControl method might
    8491
    ** also return SQLITE_ERROR.  There is no way to distinguish between
    8492
    ** an incorrect zDbName and an SQLITE_ERROR return from the underlying
    8493
    ** xFileControl method.
    8494
    **
    8495
    ** See also: [file control opcodes]
    8496
    */
    8497
    SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);
    8498
    8499
    /*
    8500
    ** CAPI3REF: Testing Interface
    8501
    **
    8502
    ** ^The sqlite3_test_control() interface is used to read out internal
    8503
    ** state of SQLite and to inject faults into SQLite for testing
    8504
    ** purposes.  ^The first parameter is an operation code that determines
    8505
    ** the number, meaning, and operation of all subsequent parameters.
    8506
    **
    8507
    ** This interface is not for use by applications.  It exists solely
    8508
    ** for verifying the correct operation of the SQLite library.  Depending
    8509
    ** on how the SQLite library is compiled, this interface might not exist.
    8510
    **
    8511
    ** The details of the operation codes, their meanings, the parameters
    8512
    ** they take, and what they do are all subject to change without notice.
    8513
    ** Unlike most of the SQLite API, this function is not guaranteed to
    8514
    ** operate consistently from one release to the next.
    8515
    */
    8516
    SQLITE_API int sqlite3_test_control(int op, ...);
    8517
    8518
    /*
    8519
    ** CAPI3REF: Testing Interface Operation Codes
    8520
    **
    8521
    ** These constants are the valid operation code parameters used
    8522
    ** as the first argument to [sqlite3_test_control()].
    8523
    **
    8524
    ** These parameters and their meanings are subject to change
    8525
    ** without notice.  These values are for testing purposes only.
    8526
    ** Applications should not use any of these parameters or the
    8527
    ** [sqlite3_test_control()] interface.
    8528
    */
    8529
    #define SQLITE_TESTCTRL_FIRST                    5
    8530
    #define SQLITE_TESTCTRL_PRNG_SAVE                5
    8531
    #define SQLITE_TESTCTRL_PRNG_RESTORE             6
    8532
    #define SQLITE_TESTCTRL_PRNG_RESET               7  /* NOT USED */
    8533
    #define SQLITE_TESTCTRL_FK_NO_ACTION             7
    8534
    #define SQLITE_TESTCTRL_BITVEC_TEST              8
    8535
    #define SQLITE_TESTCTRL_FAULT_INSTALL            9
    8536
    #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS     10
    8537
    #define SQLITE_TESTCTRL_PENDING_BYTE            11
    8538
    #define SQLITE_TESTCTRL_ASSERT                  12
    8539
    #define SQLITE_TESTCTRL_ALWAYS                  13
    8540
    #define SQLITE_TESTCTRL_RESERVE                 14  /* NOT USED */
    8541
    #define SQLITE_TESTCTRL_JSON_SELFCHECK          14
    8542
    #define SQLITE_TESTCTRL_OPTIMIZATIONS           15
    8543
    #define SQLITE_TESTCTRL_ISKEYWORD               16  /* NOT USED */
    8544
    #define SQLITE_TESTCTRL_GETOPT                  16
    8545
    #define SQLITE_TESTCTRL_SCRATCHMALLOC           17  /* NOT USED */
    8546
    #define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS      17
    8547
    #define SQLITE_TESTCTRL_LOCALTIME_FAULT         18
    8548
    #define SQLITE_TESTCTRL_EXPLAIN_STMT            19  /* NOT USED */
    8549
    #define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD    19
    8550
    #define SQLITE_TESTCTRL_NEVER_CORRUPT           20
    8551
    #define SQLITE_TESTCTRL_VDBE_COVERAGE           21
    8552
    #define SQLITE_TESTCTRL_BYTEORDER               22
    8553
    #define SQLITE_TESTCTRL_ISINIT                  23
    8554
    #define SQLITE_TESTCTRL_SORTER_MMAP             24
    8555
    #define SQLITE_TESTCTRL_IMPOSTER                25
    8556
    #define SQLITE_TESTCTRL_PARSER_COVERAGE         26
    8557
    #define SQLITE_TESTCTRL_RESULT_INTREAL          27
    8558
    #define SQLITE_TESTCTRL_PRNG_SEED               28
    8559
    #define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS     29
    8560
    #define SQLITE_TESTCTRL_SEEK_COUNT              30
    8561
    #define SQLITE_TESTCTRL_TRACEFLAGS              31
    8562
    #define SQLITE_TESTCTRL_TUNE                    32
    8563
    #define SQLITE_TESTCTRL_LOGEST                  33
    8564
    #define SQLITE_TESTCTRL_USELONGDOUBLE           34  /* NOT USED */
    8565
    #define SQLITE_TESTCTRL_LAST                    34  /* Largest TESTCTRL */
    8566
    8567
    /*
    8568
    ** CAPI3REF: SQL Keyword Checking
    8569
    **
    8570
    ** These routines provide access to the set of SQL language keywords
    8571
    ** recognized by SQLite.  Applications can use these routines to determine
    8572
    ** whether or not a specific identifier needs to be escaped (for example,
    8573
    ** by enclosing in double-quotes) so as not to confuse the parser.
    8574
    **
    8575
    ** The sqlite3_keyword_count() interface returns the number of distinct
    8576
    ** keywords understood by SQLite.
    8577
    **
    8578
    ** The sqlite3_keyword_name(N,Z,L) interface finds the 0-based N-th keyword and
    8579
    ** makes *Z point to that keyword expressed as UTF8 and writes the number
    8580
    ** of bytes in the keyword into *L.  The string that *Z points to is not
    8581
    ** zero-terminated.  The sqlite3_keyword_name(N,Z,L) routine returns
    8582
    ** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z
    8583
    ** or L are NULL or invalid pointers then calls to
    8584
    ** sqlite3_keyword_name(N,Z,L) result in undefined behavior.
    8585
    **
    8586
    ** The sqlite3_keyword_check(Z,L) interface checks to see whether or not
    8587
    ** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero
    8588
    ** if it is and zero if not.
    8589
    **
    8590
    ** The parser used by SQLite is forgiving.  It is often possible to use
    8591
    ** a keyword as an identifier as long as such use does not result in a
    8592
    ** parsing ambiguity.  For example, the statement
    8593
    ** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and
    8594
    ** creates a new table named "BEGIN" with three columns named
    8595
    ** "REPLACE", "PRAGMA", and "END".  Nevertheless, best practice is to avoid
    8596
    ** using keywords as identifiers.  Common techniques used to avoid keyword
    8597
    ** name collisions include:
    8598
    ** <ul>
    8599
    ** <li> Put all identifier names inside double-quotes.  This is the official
    8600
    **      SQL way to escape identifier names.
    8601
    ** <li> Put identifier names inside &#91;...&#93;.  This is not standard SQL,
    8602
    **      but it is what SQL Server does and so lots of programmers use this
    8603
    **      technique.
    8604
    ** <li> Begin every identifier with the letter "Z" as no SQL keywords start
    8605
    **      with "Z".
    8606
    ** <li> Include a digit somewhere in every identifier name.
    8607
    ** </ul>
    8608
    **
    8609
    ** Note that the number of keywords understood by SQLite can depend on
    8610
    ** compile-time options.  For example, "VACUUM" is not a keyword if
    8611
    ** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option.  Also,
    8612
    ** new keywords may be added to future releases of SQLite.
    8613
    */
    8614
    SQLITE_API int sqlite3_keyword_count(void);
    8615
    SQLITE_API int sqlite3_keyword_name(int,const char**,int*);
    8616
    SQLITE_API int sqlite3_keyword_check(const char*,int);
    8617
    8618
    /*
    8619
    ** CAPI3REF: Dynamic String Object
    8620
    ** KEYWORDS: {dynamic string}
    8621
    **
    8622
    ** An instance of the sqlite3_str object contains a dynamically-sized
    8623
    ** string under construction.
    8624
    **
    8625
    ** The lifecycle of an sqlite3_str object is as follows:
    8626
    ** <ol>
    8627
    ** <li> ^The sqlite3_str object is created using [sqlite3_str_new()].
    8628
    ** <li> ^Text is appended to the sqlite3_str object using various
    8629
    ** methods, such as [sqlite3_str_appendf()].
    8630
    ** <li> ^The sqlite3_str object is destroyed and the string it created
    8631
    ** is returned using the [sqlite3_str_finish()] interface.
    8632
    ** </ol>
    8633
    */
    8634
    typedef struct sqlite3_str sqlite3_str;
    8635
    8636
    /*
    8637
    ** CAPI3REF: Create A New Dynamic String Object
    8638
    ** CONSTRUCTOR: sqlite3_str
    8639
    **
    8640
    ** ^The [sqlite3_str_new(D)] interface allocates and initializes
    8641
    ** a new [sqlite3_str] object.  To avoid memory leaks, the object returned by
    8642
    ** [sqlite3_str_new()] must be freed by a subsequent call to
    8643
    ** [sqlite3_str_finish(X)].
    8644
    **
    8645
    ** ^The [sqlite3_str_new(D)] interface always returns a pointer to a
    8646
    ** valid [sqlite3_str] object, though in the event of an out-of-memory
    8647
    ** error the returned object might be a special singleton that will
    8648
    ** silently reject new text, always return SQLITE_NOMEM from
    8649
    ** [sqlite3_str_errcode()], always return 0 for
    8650
    ** [sqlite3_str_length()], and always return NULL from
    8651
    ** [sqlite3_str_finish(X)].  It is always safe to use the value
    8652
    ** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter
    8653
    ** to any of the other [sqlite3_str] methods.
    8654
    **
    8655
    ** The D parameter to [sqlite3_str_new(D)] may be NULL.  If the
    8656
    ** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum
    8657
    ** length of the string contained in the [sqlite3_str] object will be
    8658
    ** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead
    8659
    ** of [SQLITE_MAX_LENGTH].
    8660
    */
    8661
    SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*);
    8662
    8663
    /*
    8664
    ** CAPI3REF: Finalize A Dynamic String
    8665
    ** DESTRUCTOR: sqlite3_str
    8666
    **
    8667
    ** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X
    8668
    ** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()]
    8669
    ** that contains the constructed string.  The calling application should
    8670
    ** pass the returned value to [sqlite3_free()] to avoid a memory leak.
    8671
    ** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any
    8672
    ** errors were encountered during construction of the string.  ^The
    8673
    ** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the
    8674
    ** string in [sqlite3_str] object X is zero bytes long.
    8675
    */
    8676
    SQLITE_API char *sqlite3_str_finish(sqlite3_str*);
    8677
    8678
    /*
    8679
    ** CAPI3REF: Add Content To A Dynamic String
    8680
    ** METHOD: sqlite3_str
    8681
    **
    8682
    ** These interfaces add content to an sqlite3_str object previously obtained
    8683
    ** from [sqlite3_str_new()].
    8684
    **
    8685
    ** ^The [sqlite3_str_appendf(X,F,...)] and
    8686
    ** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf]
    8687
    ** functionality of SQLite to append formatted text onto the end of
    8688
    ** [sqlite3_str] object X.
    8689
    **
    8690
    ** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S
    8691
    ** onto the end of the [sqlite3_str] object X.  N must be non-negative.
    8692
    ** S must contain at least N non-zero bytes of content.  To append a
    8693
    ** zero-terminated string in its entirety, use the [sqlite3_str_appendall()]
    8694
    ** method instead.
    8695
    **
    8696
    ** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of
    8697
    ** zero-terminated string S onto the end of [sqlite3_str] object X.
    8698
    **
    8699
    ** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the
    8700
    ** single-byte character C onto the end of [sqlite3_str] object X.
    8701
    ** ^This method can be used, for example, to add whitespace indentation.
    8702
    **
    8703
    ** ^The [sqlite3_str_reset(X)] method resets the string under construction
    8704
    ** inside [sqlite3_str] object X back to zero bytes in length.
    8705
    **
    8706
    ** These methods do not return a result code.  ^If an error occurs, that fact
    8707
    ** is recorded in the [sqlite3_str] object and can be recovered by a
    8708
    ** subsequent call to [sqlite3_str_errcode(X)].
    8709
    */
    8710
    SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...);
    8711
    SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list);
    8712
    SQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N);
    8713
    SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn);
    8714
    SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C);
    8715
    SQLITE_API void sqlite3_str_reset(sqlite3_str*);
    8716
    8717
    /*
    8718
    ** CAPI3REF: Status Of A Dynamic String
    8719
    ** METHOD: sqlite3_str
    8720
    **
    8721
    ** These interfaces return the current status of an [sqlite3_str] object.
    8722
    **
    8723
    ** ^If any prior errors have occurred while constructing the dynamic string
    8724
    ** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return
    8725
    ** an appropriate error code.  ^The [sqlite3_str_errcode(X)] method returns
    8726
    ** [SQLITE_NOMEM] following any out-of-memory error, or
    8727
    ** [SQLITE_TOOBIG] if the size of the dynamic string exceeds
    8728
    ** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors.
    8729
    **
    8730
    ** ^The [sqlite3_str_length(X)] method returns the current length, in bytes,
    8731
    ** of the dynamic string under construction in [sqlite3_str] object X.
    8732
    ** ^The length returned by [sqlite3_str_length(X)] does not include the
    8733
    ** zero-termination byte.
    8734
    **
    8735
    ** ^The [sqlite3_str_value(X)] method returns a pointer to the current
    8736
    ** content of the dynamic string under construction in X.  The value
    8737
    ** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X
    8738
    ** and might be freed or altered by any subsequent method on the same
    8739
    ** [sqlite3_str] object.  Applications must not use the pointer returned by
    8740
    ** [sqlite3_str_value(X)] after any subsequent method call on the same
    8741
    ** object.  ^Applications may change the content of the string returned
    8742
    ** by [sqlite3_str_value(X)] as long as they do not write into any bytes
    8743
    ** outside the range of 0 to [sqlite3_str_length(X)] and do not read or
    8744
    ** write any byte after any subsequent sqlite3_str method call.
    8745
    */
    8746
    SQLITE_API int sqlite3_str_errcode(sqlite3_str*);
    8747
    SQLITE_API int sqlite3_str_length(sqlite3_str*);
    8748
    SQLITE_API char *sqlite3_str_value(sqlite3_str*);
    8749
    8750
    /*
    8751
    ** CAPI3REF: SQLite Runtime Status
    8752
    **
    8753
    ** ^These interfaces are used to retrieve runtime status information
    8754
    ** about the performance of SQLite, and optionally to reset various
    8755
    ** highwater marks.  ^The first argument is an integer code for
    8756
    ** the specific parameter to measure.  ^(Recognized integer codes
    8757
    ** are of the form [status parameters | SQLITE_STATUS_...].)^
    8758
    ** ^The current value of the parameter is returned into *pCurrent.
    8759
    ** ^The highest recorded value is returned in *pHighwater.  ^If the
    8760
    ** resetFlag is true, then the highest record value is reset after
    8761
    ** *pHighwater is written.  ^(Some parameters do not record the highest
    8762
    ** value.  For those parameters
    8763
    ** nothing is written into *pHighwater and the resetFlag is ignored.)^
    8764
    ** ^(Other parameters record only the highwater mark and not the current
    8765
    ** value.  For these latter parameters nothing is written into *pCurrent.)^
    8766
    **
    8767
    ** ^The sqlite3_status() and sqlite3_status64() routines return
    8768
    ** SQLITE_OK on success and a non-zero [error code] on failure.
    8769
    **
    8770
    ** If either the current value or the highwater mark is too large to
    8771
    ** be represented by a 32-bit integer, then the values returned by
    8772
    ** sqlite3_status() are undefined.
    8773
    **
    8774
    ** See also: [sqlite3_db_status()]
    8775
    */
    8776
    SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);
    8777
    SQLITE_API int sqlite3_status64(
    8778
      int op,
    8779
      sqlite3_int64 *pCurrent,
    8780
      sqlite3_int64 *pHighwater,
    8781
      int resetFlag
    8782
    );
    8783
    8784
    8785
    /*
    8786
    ** CAPI3REF: Status Parameters
    8787
    ** KEYWORDS: {status parameters}
    8788
    **
    8789
    ** These integer constants designate various run-time status parameters
    8790
    ** that can be returned by [sqlite3_status()].
    8791
    **
    8792
    ** <dl>
    8793
    ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt>
    8794
    ** <dd>This parameter is the current amount of memory checked out
    8795
    ** using [sqlite3_malloc()], either directly or indirectly.  The
    8796
    ** figure includes calls made to [sqlite3_malloc()] by the application
    8797
    ** and internal memory usage by the SQLite library.  Auxiliary page-cache
    8798
    ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
    8799
    ** this parameter.  The amount returned is the sum of the allocation
    8800
    ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^
    8801
    **
    8802
    ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt>
    8803
    ** <dd>This parameter records the largest memory allocation request
    8804
    ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
    8805
    ** internal equivalents).  Only the value returned in the
    8806
    ** *pHighwater parameter to [sqlite3_status()] is of interest.
    8807
    ** The value written into the *pCurrent parameter is undefined.</dd>)^
    8808
    **
    8809
    ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt>
    8810
    ** <dd>This parameter records the number of separate memory allocations
    8811
    ** currently checked out.</dd>)^
    8812
    **
    8813
    ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt>
    8814
    ** <dd>This parameter returns the number of pages used out of the
    8815
    ** [pagecache memory allocator] that was configured using
    8816
    ** [SQLITE_CONFIG_PAGECACHE].  The
    8817
    ** value returned is in pages, not in bytes.</dd>)^
    8818
    **
    8819
    ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]]
    8820
    ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>
    8821
    ** <dd>This parameter returns the number of bytes of page cache
    8822
    ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE]
    8823
    ** buffer and where forced to overflow to [sqlite3_malloc()].  The
    8824
    ** returned value includes allocations that overflowed because they
    8825
    ** were too large (they were larger than the "sz" parameter to
    8826
    ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
    8827
    ** no space was left in the page cache.</dd>)^
    8828
    **
    8829
    ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>
    8830
    ** <dd>This parameter records the largest memory allocation request
    8831
    ** handed to the [pagecache memory allocator].  Only the value returned in the
    8832
    ** *pHighwater parameter to [sqlite3_status()] is of interest.
    8833
    ** The value written into the *pCurrent parameter is undefined.</dd>)^
    8834
    **
    8835
    ** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt>
    8836
    ** <dd>No longer used.</dd>
    8837
    **
    8838
    ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>
    8839
    ** <dd>No longer used.</dd>
    8840
    **
    8841
    ** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt>
    8842
    ** <dd>No longer used.</dd>
    8843
    **
    8844
    ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt>
    8845
    ** <dd>The *pHighwater parameter records the deepest parser stack.
    8846
    ** The *pCurrent value is undefined.  The *pHighwater value is only
    8847
    ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
    8848
    ** </dl>
    8849
    **
    8850
    ** New status parameters may be added from time to time.
    8851
    */
    8852
    #define SQLITE_STATUS_MEMORY_USED          0
    8853
    #define SQLITE_STATUS_PAGECACHE_USED       1
    8854
    #define SQLITE_STATUS_PAGECACHE_OVERFLOW   2
    8855
    #define SQLITE_STATUS_SCRATCH_USED         3  /* NOT USED */
    8856
    #define SQLITE_STATUS_SCRATCH_OVERFLOW     4  /* NOT USED */
    8857
    #define SQLITE_STATUS_MALLOC_SIZE          5
    8858
    #define SQLITE_STATUS_PARSER_STACK         6
    8859
    #define SQLITE_STATUS_PAGECACHE_SIZE       7
    8860
    #define SQLITE_STATUS_SCRATCH_SIZE         8  /* NOT USED */
    8861
    #define SQLITE_STATUS_MALLOC_COUNT         9
    8862
    8863
    /*
    8864
    ** CAPI3REF: Database Connection Status
    8865
    ** METHOD: sqlite3
    8866
    **
    8867
    ** ^This interface is used to retrieve runtime status information
    8868
    ** about a single [database connection].  ^The first argument is the
    8869
    ** database connection object to be interrogated.  ^The second argument
    8870
    ** is an integer constant, taken from the set of
    8871
    ** [SQLITE_DBSTATUS options], that
    8872
    ** determines the parameter to interrogate.  The set of
    8873
    ** [SQLITE_DBSTATUS options] is likely
    8874
    ** to grow in future releases of SQLite.
    8875
    **
    8876
    ** ^The current value of the requested parameter is written into *pCur
    8877
    ** and the highest instantaneous value is written into *pHiwtr.  ^If
    8878
    ** the resetFlg is true, then the highest instantaneous value is
    8879
    ** reset back down to the current value.
    8880
    **
    8881
    ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a
    8882
    ** non-zero [error code] on failure.
    8883
    **
    8884
    ** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
    8885
    */
    8886
    SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
    8887
    8888
    /*
    8889
    ** CAPI3REF: Status Parameters for database connections
    8890
    ** KEYWORDS: {SQLITE_DBSTATUS options}
    8891
    **
    8892
    ** These constants are the available integer "verbs" that can be passed as
    8893
    ** the second argument to the [sqlite3_db_status()] interface.
    8894
    **
    8895
    ** New verbs may be added in future releases of SQLite. Existing verbs
    8896
    ** might be discontinued. Applications should check the return code from
    8897
    ** [sqlite3_db_status()] to make sure that the call worked.
    8898
    ** The [sqlite3_db_status()] interface will return a non-zero error code
    8899
    ** if a discontinued or unsupported verb is invoked.
    8900
    **
    8901
    ** <dl>
    8902
    ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
    8903
    ** <dd>This parameter returns the number of lookaside memory slots currently
    8904
    ** checked out.</dd>)^
    8905
    **
    8906
    ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt>
    8907
    ** <dd>This parameter returns the number of malloc attempts that were
    8908
    ** satisfied using lookaside memory. Only the high-water value is meaningful;
    8909
    ** the current value is always zero.</dd>)^
    8910
    **
    8911
    ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]]
    8912
    ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt>
    8913
    ** <dd>This parameter returns the number of malloc attempts that might have
    8914
    ** been satisfied using lookaside memory but failed due to the amount of
    8915
    ** memory requested being larger than the lookaside slot size.
    8916
    ** Only the high-water value is meaningful;
    8917
    ** the current value is always zero.</dd>)^
    8918
    **
    8919
    ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]]
    8920
    ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt>
    8921
    ** <dd>This parameter returns the number of malloc attempts that might have
    8922
    ** been satisfied using lookaside memory but failed due to all lookaside
    8923
    ** memory already being in use.
    8924
    ** Only the high-water value is meaningful;
    8925
    ** the current value is always zero.</dd>)^
    8926
    **
    8927
    ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt>
    8928
    ** <dd>This parameter returns the approximate number of bytes of heap
    8929
    ** memory used by all pager caches associated with the database connection.)^
    8930
    ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
    8931
    ** </dd>
    8932
    **
    8933
    ** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]]
    8934
    ** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt>
    8935
    ** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a
    8936
    ** pager cache is shared between two or more connections the bytes of heap
    8937
    ** memory used by that pager cache is divided evenly between the attached
    8938
    ** connections.)^  In other words, if none of the pager caches associated
    8939
    ** with the database connection are shared, this request returns the same
    8940
    ** value as DBSTATUS_CACHE_USED. Or, if one or more of the pager caches are
    8941
    ** shared, the value returned by this call will be smaller than that returned
    8942
    ** by DBSTATUS_CACHE_USED. ^The highwater mark associated with
    8943
    ** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0.</dd>
    8944
    **
    8945
    ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt>
    8946
    ** <dd>This parameter returns the approximate number of bytes of heap
    8947
    ** memory used to store the schema for all databases associated
    8948
    ** with the connection - main, temp, and any [ATTACH]-ed databases.)^
    8949
    ** ^The full amount of memory used by the schemas is reported, even if the
    8950
    ** schema memory is shared with other database connections due to
    8951
    ** [shared cache mode] being enabled.
    8952
    ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.
    8953
    ** </dd>
    8954
    **
    8955
    ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt>
    8956
    ** <dd>This parameter returns the approximate number of bytes of heap
    8957
    ** and lookaside memory used by all prepared statements associated with
    8958
    ** the database connection.)^
    8959
    ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
    8960
    ** </dd>
    8961
    **
    8962
    ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt>
    8963
    ** <dd>This parameter returns the number of pager cache hits that have
    8964
    ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT
    8965
    ** is always 0.
    8966
    ** </dd>
    8967
    **
    8968
    ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt>
    8969
    ** <dd>This parameter returns the number of pager cache misses that have
    8970
    ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS
    8971
    ** is always 0.
    8972
    ** </dd>
    8973
    **
    8974
    ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt>
    8975
    ** <dd>This parameter returns the number of dirty cache entries that have
    8976
    ** been written to disk. Specifically, the number of pages written to the
    8977
    ** wal file in wal mode databases, or the number of pages written to the
    8978
    ** database file in rollback mode databases. Any pages written as part of
    8979
    ** transaction rollback or database recovery operations are not included.
    8980
    ** If an IO or other error occurs while writing a page to disk, the effect
    8981
    ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The
    8982
    ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0.
    8983
    ** </dd>
    8984
    **
    8985
    ** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt>
    8986
    ** <dd>This parameter returns the number of dirty cache entries that have
    8987
    ** been written to disk in the middle of a transaction due to the page
    8988
    ** cache overflowing. Transactions are more efficient if they are written
    8989
    ** to disk all at once. When pages spill mid-transaction, that introduces
    8990
    ** additional overhead. This parameter can be used to help identify
    8991
    ** inefficiencies that can be resolved by increasing the cache size.
    8992
    ** </dd>
    8993
    **
    8994
    ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt>
    8995
    ** <dd>This parameter returns zero for the current value if and only if
    8996
    ** all foreign key constraints (deferred or immediate) have been
    8997
    ** resolved.)^  ^The highwater mark is always 0.
    8998
    ** </dd>
    8999
    ** </dl>
    9000
    */
    9001
    #define SQLITE_DBSTATUS_LOOKASIDE_USED       0
    9002
    #define SQLITE_DBSTATUS_CACHE_USED           1
    9003
    #define SQLITE_DBSTATUS_SCHEMA_USED          2
    9004
    #define SQLITE_DBSTATUS_STMT_USED            3
    9005
    #define SQLITE_DBSTATUS_LOOKASIDE_HIT        4
    9006
    #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE  5
    9007
    #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL  6
    9008
    #define SQLITE_DBSTATUS_CACHE_HIT            7
    9009
    #define SQLITE_DBSTATUS_CACHE_MISS           8
    9010
    #define SQLITE_DBSTATUS_CACHE_WRITE          9
    9011
    #define SQLITE_DBSTATUS_DEFERRED_FKS        10
    9012
    #define SQLITE_DBSTATUS_CACHE_USED_SHARED   11
    9013
    #define SQLITE_DBSTATUS_CACHE_SPILL         12
    9014
    #define SQLITE_DBSTATUS_MAX                 12   /* Largest defined DBSTATUS */
    9015
    9016
    9017
    /*
    9018
    ** CAPI3REF: Prepared Statement Status
    9019
    ** METHOD: sqlite3_stmt
    9020
    **
    9021
    ** ^(Each prepared statement maintains various
    9022
    ** [SQLITE_STMTSTATUS counters] that measure the number
    9023
    ** of times it has performed specific operations.)^  These counters can
    9024
    ** be used to monitor the performance characteristics of the prepared
    9025
    ** statements.  For example, if the number of table steps greatly exceeds
    9026
    ** the number of table searches or result rows, that would tend to indicate
    9027
    ** that the prepared statement is using a full table scan rather than
    9028
    ** an index.
    9029
    **
    9030
    ** ^(This interface is used to retrieve and reset counter values from
    9031
    ** a [prepared statement].  The first argument is the prepared statement
    9032
    ** object to be interrogated.  The second argument
    9033
    ** is an integer code for a specific [SQLITE_STMTSTATUS counter]
    9034
    ** to be interrogated.)^
    9035
    ** ^The current value of the requested counter is returned.
    9036
    ** ^If the resetFlg is true, then the counter is reset to zero after this
    9037
    ** interface call returns.
    9038
    **
    9039
    ** See also: [sqlite3_status()] and [sqlite3_db_status()].
    9040
    */
    9041
    SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
    9042
    9043
    /*
    9044
    ** CAPI3REF: Status Parameters for prepared statements
    9045
    ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters}
    9046
    **
    9047
    ** These preprocessor macros define integer codes that name counter
    9048
    ** values associated with the [sqlite3_stmt_status()] interface.
    9049
    ** The meanings of the various counters are as follows:
    9050
    **
    9051
    ** <dl>
    9052
    ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt>
    9053
    ** <dd>^This is the number of times that SQLite has stepped forward in
    9054
    ** a table as part of a full table scan.  Large numbers for this counter
    9055
    ** may indicate opportunities for performance improvement through
    9056
    ** careful use of indices.</dd>
    9057
    **
    9058
    ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt>
    9059
    ** <dd>^This is the number of sort operations that have occurred.
    9060
    ** A non-zero value in this counter may indicate an opportunity to
    9061
    ** improve performance through careful use of indices.</dd>
    9062
    **
    9063
    ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt>
    9064
    ** <dd>^This is the number of rows inserted into transient indices that
    9065
    ** were created automatically in order to help joins run faster.
    9066
    ** A non-zero value in this counter may indicate an opportunity to
    9067
    ** improve performance by adding permanent indices that do not
    9068
    ** need to be reinitialized each time the statement is run.</dd>
    9069
    **
    9070
    ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt>
    9071
    ** <dd>^This is the number of virtual machine operations executed
    9072
    ** by the prepared statement if that number is less than or equal
    9073
    ** to 2147483647.  The number of virtual machine operations can be
    9074
    ** used as a proxy for the total work done by the prepared statement.
    9075
    ** If the number of virtual machine operations exceeds 2147483647
    9076
    ** then the value returned by this statement status code is undefined.</dd>
    9077
    **
    9078
    ** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt>
    9079
    ** <dd>^This is the number of times that the prepare statement has been
    9080
    ** automatically regenerated due to schema changes or changes to
    9081
    ** [bound parameters] that might affect the query plan.</dd>
    9082
    **
    9083
    ** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt>
    9084
    ** <dd>^This is the number of times that the prepared statement has
    9085
    ** been run.  A single "run" for the purposes of this counter is one
    9086
    ** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()].
    9087
    ** The counter is incremented on the first [sqlite3_step()] call of each
    9088
    ** cycle.</dd>
    9089
    **
    9090
    ** [[SQLITE_STMTSTATUS_FILTER_MISS]]
    9091
    ** [[SQLITE_STMTSTATUS_FILTER HIT]]
    9092
    ** <dt>SQLITE_STMTSTATUS_FILTER_HIT<br>
    9093
    ** SQLITE_STMTSTATUS_FILTER_MISS</dt>
    9094
    ** <dd>^SQLITE_STMTSTATUS_FILTER_HIT is the number of times that a join
    9095
    ** step was bypassed because a Bloom filter returned not-found.  The
    9096
    ** corresponding SQLITE_STMTSTATUS_FILTER_MISS value is the number of
    9097
    ** times that the Bloom filter returned a find, and thus the join step
    9098
    ** had to be processed as normal.</dd>
    9099
    **
    9100
    ** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt>
    9101
    ** <dd>^This is the approximate number of bytes of heap memory
    9102
    ** used to store the prepared statement.  ^This value is not actually
    9103
    ** a counter, and so the resetFlg parameter to sqlite3_stmt_status()
    9104
    ** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED.
    9105
    ** </dd>
    9106
    ** </dl>
    9107
    */
    9108
    #define SQLITE_STMTSTATUS_FULLSCAN_STEP     1
    9109
    #define SQLITE_STMTSTATUS_SORT              2
    9110
    #define SQLITE_STMTSTATUS_AUTOINDEX         3
    9111
    #define SQLITE_STMTSTATUS_VM_STEP           4
    9112
    #define SQLITE_STMTSTATUS_REPREPARE         5
    9113
    #define SQLITE_STMTSTATUS_RUN               6
    9114
    #define SQLITE_STMTSTATUS_FILTER_MISS       7
    9115
    #define SQLITE_STMTSTATUS_FILTER_HIT        8
    9116
    #define SQLITE_STMTSTATUS_MEMUSED           99
    9117
    9118
    /*
    9119
    ** CAPI3REF: Custom Page Cache Object
    9120
    **
    9121
    ** The sqlite3_pcache type is opaque.  It is implemented by
    9122
    ** the pluggable module.  The SQLite core has no knowledge of
    9123
    ** its size or internal structure and never deals with the
    9124
    ** sqlite3_pcache object except by holding and passing pointers
    9125
    ** to the object.
    9126
    **
    9127
    ** See [sqlite3_pcache_methods2] for additional information.
    9128
    */
    9129
    typedef struct sqlite3_pcache sqlite3_pcache;
    9130
    9131
    /*
    9132
    ** CAPI3REF: Custom Page Cache Object
    9133
    **
    9134
    ** The sqlite3_pcache_page object represents a single page in the
    9135
    ** page cache.  The page cache will allocate instances of this
    9136
    ** object.  Various methods of the page cache use pointers to instances
    9137
    ** of this object as parameters or as their return value.
    9138
    **
    9139
    ** See [sqlite3_pcache_methods2] for additional information.
    9140
    */
    9141
    typedef struct sqlite3_pcache_page sqlite3_pcache_page;
    9142
    struct sqlite3_pcache_page {
    9143
      void *pBuf;        /* The content of the page */
    9144
      void *pExtra;      /* Extra information associated with the page */
    9145
    };
    9146
    9147
    /*
    9148
    ** CAPI3REF: Application Defined Page Cache.
    9149
    ** KEYWORDS: {page cache}
    9150
    **
    9151
    ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can
    9152
    ** register an alternative page cache implementation by passing in an
    9153
    ** instance of the sqlite3_pcache_methods2 structure.)^
    9154
    ** In many applications, most of the heap memory allocated by
    9155
    ** SQLite is used for the page cache.
    9156
    ** By implementing a
    9157
    ** custom page cache using this API, an application can better control
    9158
    ** the amount of memory consumed by SQLite, the way in which
    9159
    ** that memory is allocated and released, and the policies used to
    9160
    ** determine exactly which parts of a database file are cached and for
    9161
    ** how long.
    9162
    **
    9163
    ** The alternative page cache mechanism is an
    9164
    ** extreme measure that is only needed by the most demanding applications.
    9165
    ** The built-in page cache is recommended for most uses.
    9166
    **
    9167
    ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an
    9168
    ** internal buffer by SQLite within the call to [sqlite3_config].  Hence
    9169
    ** the application may discard the parameter after the call to
    9170
    ** [sqlite3_config()] returns.)^
    9171
    **
    9172
    ** [[the xInit() page cache method]]
    9173
    ** ^(The xInit() method is called once for each effective
    9174
    ** call to [sqlite3_initialize()])^
    9175
    ** (usually only once during the lifetime of the process). ^(The xInit()
    9176
    ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^
    9177
    ** The intent of the xInit() method is to set up global data structures
    9178
    ** required by the custom page cache implementation.
    9179
    ** ^(If the xInit() method is NULL, then the
    9180
    ** built-in default page cache is used instead of the application defined
    9181
    ** page cache.)^
    9182
    **
    9183
    ** [[the xShutdown() page cache method]]
    9184
    ** ^The xShutdown() method is called by [sqlite3_shutdown()].
    9185
    ** It can be used to clean up
    9186
    ** any outstanding resources before process shutdown, if required.
    9187
    ** ^The xShutdown() method may be NULL.
    9188
    **
    9189
    ** ^SQLite automatically serializes calls to the xInit method,
    9190
    ** so the xInit method need not be threadsafe.  ^The
    9191
    ** xShutdown method is only called from [sqlite3_shutdown()] so it does
    9192
    ** not need to be threadsafe either.  All other methods must be threadsafe
    9193
    ** in multithreaded applications.
    9194
    **
    9195
    ** ^SQLite will never invoke xInit() more than once without an intervening
    9196
    ** call to xShutdown().
    9197
    **
    9198
    ** [[the xCreate() page cache methods]]
    9199
    ** ^SQLite invokes the xCreate() method to construct a new cache instance.
    9200
    ** SQLite will typically create one cache instance for each open database file,
    9201
    ** though this is not guaranteed. ^The
    9202
    ** first parameter, szPage, is the size in bytes of the pages that must
    9203
    ** be allocated by the cache.  ^szPage will always be a power of two.  ^The
    9204
    ** second parameter szExtra is a number of bytes of extra storage
    9205
    ** associated with each page cache entry.  ^The szExtra parameter will be
    9206
    ** a number less than 250.  SQLite will use the
    9207
    ** extra szExtra bytes on each page to store metadata about the underlying
    9208
    ** database page on disk.  The value passed into szExtra depends
    9209
    ** on the SQLite version, the target platform, and how SQLite was compiled.
    9210
    ** ^The third argument to xCreate(), bPurgeable, is true if the cache being
    9211
    ** created will be used to cache database pages of a file stored on disk, or
    9212
    ** false if it is used for an in-memory database. The cache implementation
    9213
    ** does not have to do anything special based upon the value of bPurgeable;
    9214
    ** it is purely advisory.  ^On a cache where bPurgeable is false, SQLite will
    9215
    ** never invoke xUnpin() except to deliberately delete a page.
    9216
    ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to
    9217
    ** false will always have the "discard" flag set to true.
    9218
    ** ^Hence, a cache created with bPurgeable set to false will
    9219
    ** never contain any unpinned pages.
    9220
    **
    9221
    ** [[the xCachesize() page cache method]]
    9222
    ** ^(The xCachesize() method may be called at any time by SQLite to set the
    9223
    ** suggested maximum cache-size (number of pages stored) for the cache
    9224
    ** instance passed as the first argument. This is the value configured using
    9225
    ** the SQLite "[PRAGMA cache_size]" command.)^  As with the bPurgeable
    9226
    ** parameter, the implementation is not required to do anything with this
    9227
    ** value; it is advisory only.
    9228
    **
    9229
    ** [[the xPagecount() page cache methods]]
    9230
    ** The xPagecount() method must return the number of pages currently
    9231
    ** stored in the cache, both pinned and unpinned.
    9232
    **
    9233
    ** [[the xFetch() page cache methods]]
    9234
    ** The xFetch() method locates a page in the cache and returns a pointer to
    9235
    ** an sqlite3_pcache_page object associated with that page, or a NULL pointer.
    9236
    ** The pBuf element of the returned sqlite3_pcache_page object will be a
    9237
    ** pointer to a buffer of szPage bytes used to store the content of a
    9238
    ** single database page.  The pExtra element of sqlite3_pcache_page will be
    9239
    ** a pointer to the szExtra bytes of extra storage that SQLite has requested
    9240
    ** for each entry in the page cache.
    9241
    **
    9242
    ** The page to be fetched is determined by the key. ^The minimum key value
    9243
    ** is 1.  After it has been retrieved using xFetch, the page is considered
    9244
    ** to be "pinned".
    9245
    **
    9246
    ** If the requested page is already in the page cache, then the page cache
    9247
    ** implementation must return a pointer to the page buffer with its content
    9248
    ** intact.  If the requested page is not already in the cache, then the
    9249
    ** cache implementation should use the value of the createFlag
    9250
    ** parameter to help it determine what action to take:
    9251
    **
    9252
    ** <table border=1 width=85% align=center>
    9253
    ** <tr><th> createFlag <th> Behavior when page is not already in cache
    9254
    ** <tr><td> 0 <td> Do not allocate a new page.  Return NULL.
    9255
    ** <tr><td> 1 <td> Allocate a new page if it is easy and convenient to do so.
    9256
    **                 Otherwise return NULL.
    9257
    ** <tr><td> 2 <td> Make every effort to allocate a new page.  Only return
    9258
    **                 NULL if allocating a new page is effectively impossible.
    9259
    ** </table>
    9260
    **
    9261
    ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1.  SQLite
    9262
    ** will only use a createFlag of 2 after a prior call with a createFlag of 1
    9263
    ** failed.)^  In between the xFetch() calls, SQLite may
    9264
    ** attempt to unpin one or more cache pages by spilling the content of
    9265
    ** pinned pages to disk and synching the operating system disk cache.
    9266
    **
    9267
    ** [[the xUnpin() page cache method]]
    9268
    ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page
    9269
    ** as its second argument.  If the third parameter, discard, is non-zero,
    9270
    ** then the page must be evicted from the cache.
    9271
    ** ^If the discard parameter is
    9272
    ** zero, then the page may be discarded or retained at the discretion of the
    9273
    ** page cache implementation. ^The page cache implementation
    9274
    ** may choose to evict unpinned pages at any time.
    9275
    **
    9276
    ** The cache must not perform any reference counting. A single
    9277
    ** call to xUnpin() unpins the page regardless of the number of prior calls
    9278
    ** to xFetch().
    9279
    **
    9280
    ** [[the xRekey() page cache methods]]
    9281
    ** The xRekey() method is used to change the key value associated with the
    9282
    ** page passed as the second argument. If the cache
    9283
    ** previously contains an entry associated with newKey, it must be
    9284
    ** discarded. ^Any prior cache entry associated with newKey is guaranteed not
    9285
    ** to be pinned.
    9286
    **
    9287
    ** When SQLite calls the xTruncate() method, the cache must discard all
    9288
    ** existing cache entries with page numbers (keys) greater than or equal
    9289
    ** to the value of the iLimit parameter passed to xTruncate(). If any
    9290
    ** of these pages are pinned, they become implicitly unpinned, meaning that
    9291
    ** they can be safely discarded.
    9292
    **
    9293
    ** [[the xDestroy() page cache method]]
    9294
    ** ^The xDestroy() method is used to delete a cache allocated by xCreate().
    9295
    ** All resources associated with the specified cache should be freed. ^After
    9296
    ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
    9297
    ** handle invalid, and will not use it with any other sqlite3_pcache_methods2
    9298
    ** functions.
    9299
    **
    9300
    ** [[the xShrink() page cache method]]
    9301
    ** ^SQLite invokes the xShrink() method when it wants the page cache to
    9302
    ** free up as much of heap memory as possible.  The page cache implementation
    9303
    ** is not obligated to free any memory, but well-behaved implementations should
    9304
    ** do their best.
    9305
    */
    9306
    typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2;
    9307
    struct sqlite3_pcache_methods2 {
    9308
      int iVersion;
    9309
      void *pArg;
    9310
      int (*xInit)(void*);
    9311
      void (*xShutdown)(void*);
    9312
      sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable);
    9313
      void (*xCachesize)(sqlite3_pcache*, int nCachesize);
    9314
      int (*xPagecount)(sqlite3_pcache*);
    9315
      sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
    9316
      void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard);
    9317
      void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*,
    9318
          unsigned oldKey, unsigned newKey);
    9319
      void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
    9320
      void (*xDestroy)(sqlite3_pcache*);
    9321
      void (*xShrink)(sqlite3_pcache*);
    9322
    };
    9323
    9324
    /*
    9325
    ** This is the obsolete pcache_methods object that has now been replaced
    9326
    ** by sqlite3_pcache_methods2.  This object is not used by SQLite.  It is
    9327
    ** retained in the header file for backwards compatibility only.
    9328
    */
    9329
    typedef struct sqlite3_pcache_methods sqlite3_pcache_methods;
    9330
    struct sqlite3_pcache_methods {
    9331
      void *pArg;
    9332
      int (*xInit)(void*);
    9333
      void (*xShutdown)(void*);
    9334
      sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable);
    9335
      void (*xCachesize)(sqlite3_pcache*, int nCachesize);
    9336
      int (*xPagecount)(sqlite3_pcache*);
    9337
      void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
    9338
      void (*xUnpin)(sqlite3_pcache*, void*, int discard);
    9339
      void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey);
    9340
      void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
    9341
      void (*xDestroy)(sqlite3_pcache*);
    9342
    };
    9343
    9344
    9345
    /*
    9346
    ** CAPI3REF: Online Backup Object
    9347
    **
    9348
    ** The sqlite3_backup object records state information about an ongoing
    9349
    ** online backup operation.  ^The sqlite3_backup object is created by
    9350
    ** a call to [sqlite3_backup_init()] and is destroyed by a call to
    9351
    ** [sqlite3_backup_finish()].
    9352
    **
    9353
    ** See Also: [Using the SQLite Online Backup API]
    9354
    */
    9355
    typedef struct sqlite3_backup sqlite3_backup;
    9356
    9357
    /*
    9358
    ** CAPI3REF: Online Backup API.
    9359
    **
    9360
    ** The backup API copies the content of one database into another.
    9361
    ** It is useful either for creating backups of databases or
    9362
    ** for copying in-memory databases to or from persistent files.
    9363
    **
    9364
    ** See Also: [Using the SQLite Online Backup API]
    9365
    **
    9366
    ** ^SQLite holds a write transaction open on the destination database file
    9367
    ** for the duration of the backup operation.
    9368
    ** ^The source database is read-locked only while it is being read;
    9369
    ** it is not locked continuously for the entire backup operation.
    9370
    ** ^Thus, the backup may be performed on a live source database without
    9371
    ** preventing other database connections from
    9372
    ** reading or writing to the source database while the backup is underway.
    9373
    **
    9374
    ** ^(To perform a backup operation:
    9375
    **   <ol>
    9376
    **     <li><b>sqlite3_backup_init()</b> is called once to initialize the
    9377
    **         backup,
    9378
    **     <li><b>sqlite3_backup_step()</b> is called one or more times to transfer
    9379
    **         the data between the two databases, and finally
    9380
    **     <li><b>sqlite3_backup_finish()</b> is called to release all resources
    9381
    **         associated with the backup operation.
    9382
    **   </ol>)^
    9383
    ** There should be exactly one call to sqlite3_backup_finish() for each
    9384
    ** successful call to sqlite3_backup_init().
    9385
    **
    9386
    ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b>
    9387
    **
    9388
    ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the
    9389
    ** [database connection] associated with the destination database
    9390
    ** and the database name, respectively.
    9391
    ** ^The database name is "main" for the main database, "temp" for the
    9392
    ** temporary database, or the name specified after the AS keyword in
    9393
    ** an [ATTACH] statement for an attached database.
    9394
    ** ^The S and M arguments passed to
    9395
    ** sqlite3_backup_init(D,N,S,M) identify the [database connection]
    9396
    ** and database name of the source database, respectively.
    9397
    ** ^The source and destination [database connections] (parameters S and D)
    9398
    ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
    9399
    ** an error.
    9400
    **
    9401
    ** ^A call to sqlite3_backup_init() will fail, returning NULL, if
    9402
    ** there is already a read or read-write transaction open on the
    9403
    ** destination database.
    9404
    **
    9405
    ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
    9406
    ** returned and an error code and error message are stored in the
    9407
    ** destination [database connection] D.
    9408
    ** ^The error code and message for the failed call to sqlite3_backup_init()
    9409
    ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
    9410
    ** [sqlite3_errmsg16()] functions.
    9411
    ** ^A successful call to sqlite3_backup_init() returns a pointer to an
    9412
    ** [sqlite3_backup] object.
    9413
    ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and
    9414
    ** sqlite3_backup_finish() functions to perform the specified backup
    9415
    ** operation.
    9416
    **
    9417
    ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b>
    9418
    **
    9419
    ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between
    9420
    ** the source and destination databases specified by [sqlite3_backup] object B.
    9421
    ** ^If N is negative, all remaining source pages are copied.
    9422
    ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there
    9423
    ** are still more pages to be copied, then the function returns [SQLITE_OK].
    9424
    ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages
    9425
    ** from source to destination, then it returns [SQLITE_DONE].
    9426
    ** ^If an error occurs while running sqlite3_backup_step(B,N),
    9427
    ** then an [error code] is returned. ^As well as [SQLITE_OK] and
    9428
    ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
    9429
    ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an
    9430
    ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
    9431
    **
    9432
    ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if
    9433
    ** <ol>
    9434
    ** <li> the destination database was opened read-only, or
    9435
    ** <li> the destination database is using write-ahead-log journaling
    9436
    ** and the destination and source page sizes differ, or
    9437
    ** <li> the destination database is an in-memory database and the
    9438
    ** destination and source page sizes differ.
    9439
    ** </ol>)^
    9440
    **
    9441
    ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then
    9442
    ** the [sqlite3_busy_handler | busy-handler function]
    9443
    ** is invoked (if one is specified). ^If the
    9444
    ** busy-handler returns non-zero before the lock is available, then
    9445
    ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to
    9446
    ** sqlite3_backup_step() can be retried later. ^If the source
    9447
    ** [database connection]
    9448
    ** is being used to write to the source database when sqlite3_backup_step()
    9449
    ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this
    9450
    ** case the call to sqlite3_backup_step() can be retried later on. ^(If
    9451
    ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or
    9452
    ** [SQLITE_READONLY] is returned, then
    9453
    ** there is no point in retrying the call to sqlite3_backup_step(). These
    9454
    ** errors are considered fatal.)^  The application must accept
    9455
    ** that the backup operation has failed and pass the backup operation handle
    9456
    ** to the sqlite3_backup_finish() to release associated resources.
    9457
    **
    9458
    ** ^The first call to sqlite3_backup_step() obtains an exclusive lock
    9459
    ** on the destination file. ^The exclusive lock is not released until either
    9460
    ** sqlite3_backup_finish() is called or the backup operation is complete
    9461
    ** and sqlite3_backup_step() returns [SQLITE_DONE].  ^Every call to
    9462
    ** sqlite3_backup_step() obtains a [shared lock] on the source database that
    9463
    ** lasts for the duration of the sqlite3_backup_step() call.
    9464
    ** ^Because the source database is not locked between calls to
    9465
    ** sqlite3_backup_step(), the source database may be modified mid-way
    9466
    ** through the backup process.  ^If the source database is modified by an
    9467
    ** external process or via a database connection other than the one being
    9468
    ** used by the backup operation, then the backup will be automatically
    9469
    ** restarted by the next call to sqlite3_backup_step(). ^If the source
    9470
    ** database is modified by using the same database connection as is used
    9471
    ** by the backup operation, then the backup database is automatically
    9472
    ** updated at the same time.
    9473
    **
    9474
    ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b>
    9475
    **
    9476
    ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the
    9477
    ** application wishes to abandon the backup operation, the application
    9478
    ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish().
    9479
    ** ^The sqlite3_backup_finish() interfaces releases all
    9480
    ** resources associated with the [sqlite3_backup] object.
    9481
    ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any
    9482
    ** active write-transaction on the destination database is rolled back.
    9483
    ** The [sqlite3_backup] object is invalid
    9484
    ** and may not be used following a call to sqlite3_backup_finish().
    9485
    **
    9486
    ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no
    9487
    ** sqlite3_backup_step() errors occurred, regardless of whether or not
    9488
    ** sqlite3_backup_step() completed.
    9489
    ** ^If an out-of-memory condition or IO error occurred during any prior
    9490
    ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then
    9491
    ** sqlite3_backup_finish() returns the corresponding [error code].
    9492
    **
    9493
    ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step()
    9494
    ** is not a permanent error and does not affect the return value of
    9495
    ** sqlite3_backup_finish().
    9496
    **
    9497
    ** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]]
    9498
    ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b>
    9499
    **
    9500
    ** ^The sqlite3_backup_remaining() routine returns the number of pages still
    9501
    ** to be backed up at the conclusion of the most recent sqlite3_backup_step().
    9502
    ** ^The sqlite3_backup_pagecount() routine returns the total number of pages
    9503
    ** in the source database at the conclusion of the most recent
    9504
    ** sqlite3_backup_step().
    9505
    ** ^(The values returned by these functions are only updated by
    9506
    ** sqlite3_backup_step(). If the source database is modified in a way that
    9507
    ** changes the size of the source database or the number of pages remaining,
    9508
    ** those changes are not reflected in the output of sqlite3_backup_pagecount()
    9509
    ** and sqlite3_backup_remaining() until after the next
    9510
    ** sqlite3_backup_step().)^
    9511
    **
    9512
    ** <b>Concurrent Usage of Database Handles</b>
    9513
    **
    9514
    ** ^The source [database connection] may be used by the application for other
    9515
    ** purposes while a backup operation is underway or being initialized.
    9516
    ** ^If SQLite is compiled and configured to support threadsafe database
    9517
    ** connections, then the source database connection may be used concurrently
    9518
    ** from within other threads.
    9519
    **
    9520
    ** However, the application must guarantee that the destination
    9521
    ** [database connection] is not passed to any other API (by any thread) after
    9522
    ** sqlite3_backup_init() is called and before the corresponding call to
    9523
    ** sqlite3_backup_finish().  SQLite does not currently check to see
    9524
    ** if the application incorrectly accesses the destination [database connection]
    9525
    ** and so no error code is reported, but the operations may malfunction
    9526
    ** nevertheless.  Use of the destination database connection while a
    9527
    ** backup is in progress might also cause a mutex deadlock.
    9528
    **
    9529
    ** If running in [shared cache mode], the application must
    9530
    ** guarantee that the shared cache used by the destination database
    9531
    ** is not accessed while the backup is running. In practice this means
    9532
    ** that the application must guarantee that the disk file being
    9533
    ** backed up to is not accessed by any connection within the process,
    9534
    ** not just the specific connection that was passed to sqlite3_backup_init().
    9535
    **
    9536
    ** The [sqlite3_backup] object itself is partially threadsafe. Multiple
    9537
    ** threads may safely make multiple concurrent calls to sqlite3_backup_step().
    9538
    ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()
    9539
    ** APIs are not strictly speaking threadsafe. If they are invoked at the
    9540
    ** same time as another thread is invoking sqlite3_backup_step() it is
    9541
    ** possible that they return invalid values.
    9542
    **
    9543
    ** <b>Alternatives To Using The Backup API</b>
    9544
    **
    9545
    ** Other techniques for safely creating a consistent backup of an SQLite
    9546
    ** database include:
    9547
    **
    9548
    ** <ul>
    9549
    ** <li> The [VACUUM INTO] command.
    9550
    ** <li> The [sqlite3_rsync] utility program.
    9551
    ** </ul>
    9552
    */
    9553
    SQLITE_API sqlite3_backup *sqlite3_backup_init(
    9554
      sqlite3 *pDest,                        /* Destination database handle */
    9555
      const char *zDestName,                 /* Destination database name */
    9556
      sqlite3 *pSource,                      /* Source database handle */
    9557
      const char *zSourceName                /* Source database name */
    9558
    );
    9559
    SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage);
    9560
    SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p);
    9561
    SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p);
    9562
    SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p);
    9563
    9564
    /*
    9565
    ** CAPI3REF: Unlock Notification
    9566
    ** METHOD: sqlite3
    9567
    **
    9568
    ** ^When running in shared-cache mode, a database operation may fail with
    9569
    ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
    9570
    ** individual tables within the shared-cache cannot be obtained. See
    9571
    ** [SQLite Shared-Cache Mode] for a description of shared-cache locking.
    9572
    ** ^This API may be used to register a callback that SQLite will invoke
    9573
    ** when the connection currently holding the required lock relinquishes it.
    9574
    ** ^This API is only available if the library was compiled with the
    9575
    ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.
    9576
    **
    9577
    ** See Also: [Using the SQLite Unlock Notification Feature].
    9578
    **
    9579
    ** ^Shared-cache locks are released when a database connection concludes
    9580
    ** its current transaction, either by committing it or rolling it back.
    9581
    **
    9582
    ** ^When a connection (known as the blocked connection) fails to obtain a
    9583
    ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the
    9584
    ** identity of the database connection (the blocking connection) that
    9585
    ** has locked the required resource is stored internally. ^After an
    9586
    ** application receives an SQLITE_LOCKED error, it may call the
    9587
    ** sqlite3_unlock_notify() method with the blocked connection handle as
    9588
    ** the first argument to register for a callback that will be invoked
    9589
    ** when the blocking connection's current transaction is concluded. ^The
    9590
    ** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
    9591
    ** call that concludes the blocking connection's transaction.
    9592
    **
    9593
    ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application,
    9594
    ** there is a chance that the blocking connection will have already
    9595
    ** concluded its transaction by the time sqlite3_unlock_notify() is invoked.
    9596
    ** If this happens, then the specified callback is invoked immediately,
    9597
    ** from within the call to sqlite3_unlock_notify().)^
    9598
    **
    9599
    ** ^If the blocked connection is attempting to obtain a write-lock on a
    9600
    ** shared-cache table, and more than one other connection currently holds
    9601
    ** a read-lock on the same table, then SQLite arbitrarily selects one of
    9602
    ** the other connections to use as the blocking connection.
    9603
    **
    9604
    ** ^(There may be at most one unlock-notify callback registered by a
    9605
    ** blocked connection. If sqlite3_unlock_notify() is called when the
    9606
    ** blocked connection already has a registered unlock-notify callback,
    9607
    ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is
    9608
    ** called with a NULL pointer as its second argument, then any existing
    9609
    ** unlock-notify callback is canceled. ^The blocked connection's
    9610
    ** unlock-notify callback may also be canceled by closing the blocked
    9611
    ** connection using [sqlite3_close()].
    9612
    **
    9613
    ** The unlock-notify callback is not reentrant. If an application invokes
    9614
    ** any sqlite3_xxx API functions from within an unlock-notify callback, a
    9615
    ** crash or deadlock may be the result.
    9616
    **
    9617
    ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always
    9618
    ** returns SQLITE_OK.
    9619
    **
    9620
    ** <b>Callback Invocation Details</b>
    9621
    **
    9622
    ** When an unlock-notify callback is registered, the application provides a
    9623
    ** single void* pointer that is passed to the callback when it is invoked.
    9624
    ** However, the signature of the callback function allows SQLite to pass
    9625
    ** it an array of void* context pointers. The first argument passed to
    9626
    ** an unlock-notify callback is a pointer to an array of void* pointers,
    9627
    ** and the second is the number of entries in the array.
    9628
    **
    9629
    ** When a blocking connection's transaction is concluded, there may be
    9630
    ** more than one blocked connection that has registered for an unlock-notify
    9631
    ** callback. ^If two or more such blocked connections have specified the
    9632
    ** same callback function, then instead of invoking the callback function
    9633
    ** multiple times, it is invoked once with the set of void* context pointers
    9634
    ** specified by the blocked connections bundled together into an array.
    9635
    ** This gives the application an opportunity to prioritize any actions
    9636
    ** related to the set of unblocked database connections.
    9637
    **
    9638
    ** <b>Deadlock Detection</b>
    9639
    **
    9640
    ** Assuming that after registering for an unlock-notify callback a
    9641
    ** database waits for the callback to be issued before taking any further
    9642
    ** action (a reasonable assumption), then using this API may cause the
    9643
    ** application to deadlock. For example, if connection X is waiting for
    9644
    ** connection Y's transaction to be concluded, and similarly connection
    9645
    ** Y is waiting on connection X's transaction, then neither connection
    9646
    ** will proceed and the system may remain deadlocked indefinitely.
    9647
    **
    9648
    ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock
    9649
    ** detection. ^If a given call to sqlite3_unlock_notify() would put the
    9650
    ** system in a deadlocked state, then SQLITE_LOCKED is returned and no
    9651
    ** unlock-notify callback is registered. The system is said to be in
    9652
    ** a deadlocked state if connection A has registered for an unlock-notify
    9653
    ** callback on the conclusion of connection B's transaction, and connection
    9654
    ** B has itself registered for an unlock-notify callback when connection
    9655
    ** A's transaction is concluded. ^Indirect deadlock is also detected, so
    9656
    ** the system is also considered to be deadlocked if connection B has
    9657
    ** registered for an unlock-notify callback on the conclusion of connection
    9658
    ** C's transaction, where connection C is waiting on connection A. ^Any
    9659
    ** number of levels of indirection are allowed.
    9660
    **
    9661
    ** <b>The "DROP TABLE" Exception</b>
    9662
    **
    9663
    ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost
    9664
    ** always appropriate to call sqlite3_unlock_notify(). There is however,
    9665
    ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,
    9666
    ** SQLite checks if there are any currently executing SELECT statements
    9667
    ** that belong to the same connection. If there are, SQLITE_LOCKED is
    9668
    ** returned. In this case there is no "blocking connection", so invoking
    9669
    ** sqlite3_unlock_notify() results in the unlock-notify callback being
    9670
    ** invoked immediately. If the application then re-attempts the "DROP TABLE"
    9671
    ** or "DROP INDEX" query, an infinite loop might be the result.
    9672
    **
    9673
    ** One way around this problem is to check the extended error code returned
    9674
    ** by an sqlite3_step() call. ^(If there is a blocking connection, then the
    9675
    ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in
    9676
    ** the special "DROP TABLE/INDEX" case, the extended error code is just
    9677
    ** SQLITE_LOCKED.)^
    9678
    */
    9679
    SQLITE_API int sqlite3_unlock_notify(
    9680
      sqlite3 *pBlocked,                          /* Waiting connection */
    9681
      void (*xNotify)(void **apArg, int nArg),    /* Callback function to invoke */
    9682
      void *pNotifyArg                            /* Argument to pass to xNotify */
    9683
    );
    9684
    9685
    9686
    /*
    9687
    ** CAPI3REF: String Comparison
    9688
    **
    9689
    ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications
    9690
    ** and extensions to compare the contents of two buffers containing UTF-8
    9691
    ** strings in a case-independent fashion, using the same definition of "case
    9692
    ** independence" that SQLite uses internally when comparing identifiers.
    9693
    */
    9694
    SQLITE_API int sqlite3_stricmp(const char *, const char *);
    9695
    SQLITE_API int sqlite3_strnicmp(const char *, const char *, int);
    9696
    9697
    /*
    9698
    ** CAPI3REF: String Globbing
    9699
    *
    9700
    ** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if
    9701
    ** string X matches the [GLOB] pattern P.
    9702
    ** ^The definition of [GLOB] pattern matching used in
    9703
    ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the
    9704
    ** SQL dialect understood by SQLite.  ^The [sqlite3_strglob(P,X)] function
    9705
    ** is case sensitive.
    9706
    **
    9707
    ** Note that this routine returns zero on a match and non-zero if the strings
    9708
    ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
    9709
    **
    9710
    ** See also: [sqlite3_strlike()].
    9711
    */
    9712
    SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr);
    9713
    9714
    /*
    9715
    ** CAPI3REF: String LIKE Matching
    9716
    *
    9717
    ** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if
    9718
    ** string X matches the [LIKE] pattern P with escape character E.
    9719
    ** ^The definition of [LIKE] pattern matching used in
    9720
    ** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E"
    9721
    ** operator in the SQL dialect understood by SQLite.  ^For "X LIKE P" without
    9722
    ** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0.
    9723
    ** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case
    9724
    ** insensitive - equivalent upper and lower case ASCII characters match
    9725
    ** one another.
    9726
    **
    9727
    ** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though
    9728
    ** only ASCII characters are case folded.
    9729
    **
    9730
    ** Note that this routine returns zero on a match and non-zero if the strings
    9731
    ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
    9732
    **
    9733
    ** See also: [sqlite3_strglob()].
    9734
    */
    9735
    SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc);
    9736
    9737
    /*
    9738
    ** CAPI3REF: Error Logging Interface
    9739
    **
    9740
    ** ^The [sqlite3_log()] interface writes a message into the [error log]
    9741
    ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
    9742
    ** ^If logging is enabled, the zFormat string and subsequent arguments are
    9743
    ** used with [sqlite3_snprintf()] to generate the final output string.
    9744
    **
    9745
    ** The sqlite3_log() interface is intended for use by extensions such as
    9746
    ** virtual tables, collating functions, and SQL functions.  While there is
    9747
    ** nothing to prevent an application from calling sqlite3_log(), doing so
    9748
    ** is considered bad form.
    9749
    **
    9750
    ** The zFormat string must not be NULL.
    9751
    **
    9752
    ** To avoid deadlocks and other threading problems, the sqlite3_log() routine
    9753
    ** will not use dynamically allocated memory.  The log message is stored in
    9754
    ** a fixed-length buffer on the stack.  If the log message is longer than
    9755
    ** a few hundred characters, it will be truncated to the length of the
    9756
    ** buffer.
    9757
    */
    9758
    SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...);
    9759
    9760
    /*
    9761
    ** CAPI3REF: Write-Ahead Log Commit Hook
    9762
    ** METHOD: sqlite3
    9763
    **
    9764
    ** ^The [sqlite3_wal_hook()] function is used to register a callback that
    9765
    ** is invoked each time data is committed to a database in wal mode.
    9766
    **
    9767
    ** ^(The callback is invoked by SQLite after the commit has taken place and
    9768
    ** the associated write-lock on the database released)^, so the implementation
    9769
    ** may read, write or [checkpoint] the database as required.
    9770
    **
    9771
    ** ^The first parameter passed to the callback function when it is invoked
    9772
    ** is a copy of the third parameter passed to sqlite3_wal_hook() when
    9773
    ** registering the callback. ^The second is a copy of the database handle.
    9774
    ** ^The third parameter is the name of the database that was written to -
    9775
    ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter
    9776
    ** is the number of pages currently in the write-ahead log file,
    9777
    ** including those that were just committed.
    9778
    **
    9779
    ** The callback function should normally return [SQLITE_OK].  ^If an error
    9780
    ** code is returned, that error will propagate back up through the
    9781
    ** SQLite code base to cause the statement that provoked the callback
    9782
    ** to report an error, though the commit will have still occurred. If the
    9783
    ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value
    9784
    ** that does not correspond to any valid SQLite error code, the results
    9785
    ** are undefined.
    9786
    **
    9787
    ** A single database handle may have at most a single write-ahead log callback
    9788
    ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any
    9789
    ** previously registered write-ahead log callback. ^The return value is
    9790
    ** a copy of the third parameter from the previous call, if any, or 0.
    9791
    ** ^Note that the [sqlite3_wal_autocheckpoint()] interface and the
    9792
    ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will
    9793
    ** overwrite any prior [sqlite3_wal_hook()] settings.
    9794
    */
    9795
    SQLITE_API void *sqlite3_wal_hook(
    9796
      sqlite3*,
    9797
      int(*)(void *,sqlite3*,const char*,int),
    9798
      void*
    9799
    );
    9800
    9801
    /*
    9802
    ** CAPI3REF: Configure an auto-checkpoint
    9803
    ** METHOD: sqlite3
    9804
    **
    9805
    ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around
    9806
    ** [sqlite3_wal_hook()] that causes any database on [database connection] D
    9807
    ** to automatically [checkpoint]
    9808
    ** after committing a transaction if there are N or
    9809
    ** more frames in the [write-ahead log] file.  ^Passing zero or
    9810
    ** a negative value as the nFrame parameter disables automatic
    9811
    ** checkpoints entirely.
    9812
    **
    9813
    ** ^The callback registered by this function replaces any existing callback
    9814
    ** registered using [sqlite3_wal_hook()].  ^Likewise, registering a callback
    9815
    ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism
    9816
    ** configured by this function.
    9817
    **
    9818
    ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface
    9819
    ** from SQL.
    9820
    **
    9821
    ** ^Checkpoints initiated by this mechanism are
    9822
    ** [sqlite3_wal_checkpoint_v2|PASSIVE].
    9823
    **
    9824
    ** ^Every new [database connection] defaults to having the auto-checkpoint
    9825
    ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT]
    9826
    ** pages.  The use of this interface
    9827
    ** is only necessary if the default setting is found to be suboptimal
    9828
    ** for a particular application.
    9829
    */
    9830
    SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N);
    9831
    9832
    /*
    9833
    ** CAPI3REF: Checkpoint a database
    9834
    ** METHOD: sqlite3
    9835
    **
    9836
    ** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to
    9837
    ** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^
    9838
    **
    9839
    ** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the
    9840
    ** [write-ahead log] for database X on [database connection] D to be
    9841
    ** transferred into the database file and for the write-ahead log to
    9842
    ** be reset.  See the [checkpointing] documentation for addition
    9843
    ** information.
    9844
    **
    9845
    ** This interface used to be the only way to cause a checkpoint to
    9846
    ** occur.  But then the newer and more powerful [sqlite3_wal_checkpoint_v2()]
    9847
    ** interface was added.  This interface is retained for backwards
    9848
    ** compatibility and as a convenience for applications that need to manually
    9849
    ** start a callback but which do not need the full power (and corresponding
    9850
    ** complication) of [sqlite3_wal_checkpoint_v2()].
    9851
    */
    9852
    SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb);
    9853
    9854
    /*
    9855
    ** CAPI3REF: Checkpoint a database
    9856
    ** METHOD: sqlite3
    9857
    **
    9858
    ** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint
    9859
    ** operation on database X of [database connection] D in mode M.  Status
    9860
    ** information is written back into integers pointed to by L and C.)^
    9861
    ** ^(The M parameter must be a valid [checkpoint mode]:)^
    9862
    **
    9863
    ** <dl>
    9864
    ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd>
    9865
    **   ^Checkpoint as many frames as possible without waiting for any database
    9866
    **   readers or writers to finish, then sync the database file if all frames
    9867
    **   in the log were checkpointed. ^The [busy-handler callback]
    9868
    **   is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode.
    9869
    **   ^On the other hand, passive mode might leave the checkpoint unfinished
    9870
    **   if there are concurrent readers or writers.
    9871
    **
    9872
    ** <dt>SQLITE_CHECKPOINT_FULL<dd>
    9873
    **   ^This mode blocks (it invokes the
    9874
    **   [sqlite3_busy_handler|busy-handler callback]) until there is no
    9875
    **   database writer and all readers are reading from the most recent database
    9876
    **   snapshot. ^It then checkpoints all frames in the log file and syncs the
    9877
    **   database file. ^This mode blocks new database writers while it is pending,
    9878
    **   but new database readers are allowed to continue unimpeded.
    9879
    **
    9880
    ** <dt>SQLITE_CHECKPOINT_RESTART<dd>
    9881
    **   ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition
    9882
    **   that after checkpointing the log file it blocks (calls the
    9883
    **   [busy-handler callback])
    9884
    **   until all readers are reading from the database file only. ^This ensures
    9885
    **   that the next writer will restart the log file from the beginning.
    9886
    **   ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new
    9887
    **   database writer attempts while it is pending, but does not impede readers.
    9888
    **
    9889
    ** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd>
    9890
    **   ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the
    9891
    **   addition that it also truncates the log file to zero bytes just prior
    9892
    **   to a successful return.
    9893
    ** </dl>
    9894
    **
    9895
    ** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in
    9896
    ** the log file or to -1 if the checkpoint could not run because
    9897
    ** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not
    9898
    ** NULL,then *pnCkpt is set to the total number of checkpointed frames in the
    9899
    ** log file (including any that were already checkpointed before the function
    9900
    ** was called) or to -1 if the checkpoint could not run due to an error or
    9901
    ** because the database is not in WAL mode. ^Note that upon successful
    9902
    ** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been
    9903
    ** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero.
    9904
    **
    9905
    ** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If
    9906
    ** any other process is running a checkpoint operation at the same time, the
    9907
    ** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a
    9908
    ** busy-handler configured, it will not be invoked in this case.
    9909
    **
    9910
    ** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the
    9911
    ** exclusive "writer" lock on the database file. ^If the writer lock cannot be
    9912
    ** obtained immediately, and a busy-handler is configured, it is invoked and
    9913
    ** the writer lock retried until either the busy-handler returns 0 or the lock
    9914
    ** is successfully obtained. ^The busy-handler is also invoked while waiting for
    9915
    ** database readers as described above. ^If the busy-handler returns 0 before
    9916
    ** the writer lock is obtained or while waiting for database readers, the
    9917
    ** checkpoint operation proceeds from that point in the same way as
    9918
    ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible
    9919
    ** without blocking any further. ^SQLITE_BUSY is returned in this case.
    9920
    **
    9921
    ** ^If parameter zDb is NULL or points to a zero length string, then the
    9922
    ** specified operation is attempted on all WAL databases [attached] to
    9923
    ** [database connection] db.  In this case the
    9924
    ** values written to output parameters *pnLog and *pnCkpt are undefined. ^If
    9925
    ** an SQLITE_BUSY error is encountered when processing one or more of the
    9926
    ** attached WAL databases, the operation is still attempted on any remaining
    9927
    ** attached databases and SQLITE_BUSY is returned at the end. ^If any other
    9928
    ** error occurs while processing an attached database, processing is abandoned
    9929
    ** and the error code is returned to the caller immediately. ^If no error
    9930
    ** (SQLITE_BUSY or otherwise) is encountered while processing the attached
    9931
    ** databases, SQLITE_OK is returned.
    9932
    **
    9933
    ** ^If database zDb is the name of an attached database that is not in WAL
    9934
    ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If
    9935
    ** zDb is not NULL (or a zero length string) and is not the name of any
    9936
    ** attached database, SQLITE_ERROR is returned to the caller.
    9937
    **
    9938
    ** ^Unless it returns SQLITE_MISUSE,
    9939
    ** the sqlite3_wal_checkpoint_v2() interface
    9940
    ** sets the error information that is queried by
    9941
    ** [sqlite3_errcode()] and [sqlite3_errmsg()].
    9942
    **
    9943
    ** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface
    9944
    ** from SQL.
    9945
    */
    9946
    SQLITE_API int sqlite3_wal_checkpoint_v2(
    9947
      sqlite3 *db,                    /* Database handle */
    9948
      const char *zDb,                /* Name of attached database (or NULL) */
    9949
      int eMode,                      /* SQLITE_CHECKPOINT_* value */
    9950
      int *pnLog,                     /* OUT: Size of WAL log in frames */
    9951
      int *pnCkpt                     /* OUT: Total number of frames checkpointed */
    9952
    );
    9953
    9954
    /*
    9955
    ** CAPI3REF: Checkpoint Mode Values
    9956
    ** KEYWORDS: {checkpoint mode}
    9957
    **
    9958
    ** These constants define all valid values for the "checkpoint mode" passed
    9959
    ** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface.
    9960
    ** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the
    9961
    ** meaning of each of these checkpoint modes.
    9962
    */
    9963
    #define SQLITE_CHECKPOINT_PASSIVE  0  /* Do as much as possible w/o blocking */
    9964
    #define SQLITE_CHECKPOINT_FULL     1  /* Wait for writers, then checkpoint */
    9965
    #define SQLITE_CHECKPOINT_RESTART  2  /* Like FULL but wait for readers */
    9966
    #define SQLITE_CHECKPOINT_TRUNCATE 3  /* Like RESTART but also truncate WAL */
    9967
    9968
    /*
    9969
    ** CAPI3REF: Virtual Table Interface Configuration
    9970
    **
    9971
    ** This function may be called by either the [xConnect] or [xCreate] method
    9972
    ** of a [virtual table] implementation to configure
    9973
    ** various facets of the virtual table interface.
    9974
    **
    9975
    ** If this interface is invoked outside the context of an xConnect or
    9976
    ** xCreate virtual table method then the behavior is undefined.
    9977
    **
    9978
    ** In the call sqlite3_vtab_config(D,C,...) the D parameter is the
    9979
    ** [database connection] in which the virtual table is being created and
    9980
    ** which is passed in as the first argument to the [xConnect] or [xCreate]
    9981
    ** method that is invoking sqlite3_vtab_config().  The C parameter is one
    9982
    ** of the [virtual table configuration options].  The presence and meaning
    9983
    ** of parameters after C depend on which [virtual table configuration option]
    9984
    ** is used.
    9985
    */
    9986
    SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...);
    9987
    9988
    /*
    9989
    ** CAPI3REF: Virtual Table Configuration Options
    9990
    ** KEYWORDS: {virtual table configuration options}
    9991
    ** KEYWORDS: {virtual table configuration option}
    9992
    **
    9993
    ** These macros define the various options to the
    9994
    ** [sqlite3_vtab_config()] interface that [virtual table] implementations
    9995
    ** can use to customize and optimize their behavior.
    9996
    **
    9997
    ** <dl>
    9998
    ** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]]
    9999
    ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT</dt>
    10000
    ** <dd>Calls of the form
    10001
    ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported,
    10002
    ** where X is an integer.  If X is zero, then the [virtual table] whose
    10003
    ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not
    10004
    ** support constraints.  In this configuration (which is the default) if
    10005
    ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire
    10006
    ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been
    10007
    ** specified as part of the user's SQL statement, regardless of the actual
    10008
    ** ON CONFLICT mode specified.
    10009
    **
    10010
    ** If X is non-zero, then the virtual table implementation guarantees
    10011
    ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before
    10012
    ** any modifications to internal or persistent data structures have been made.
    10013
    ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite
    10014
    ** is able to roll back a statement or database transaction, and abandon
    10015
    ** or continue processing the current SQL statement as appropriate.
    10016
    ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns
    10017
    ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode
    10018
    ** had been ABORT.
    10019
    **
    10020
    ** Virtual table implementations that are required to handle OR REPLACE
    10021
    ** must do so within the [xUpdate] method. If a call to the
    10022
    ** [sqlite3_vtab_on_conflict()] function indicates that the current ON
    10023
    ** CONFLICT policy is REPLACE, the virtual table implementation should
    10024
    ** silently replace the appropriate rows within the xUpdate callback and
    10025
    ** return SQLITE_OK. Or, if this is not possible, it may return
    10026
    ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT
    10027
    ** constraint handling.
    10028
    ** </dd>
    10029
    **
    10030
    ** [[SQLITE_VTAB_DIRECTONLY]]<dt>SQLITE_VTAB_DIRECTONLY</dt>
    10031
    ** <dd>Calls of the form
    10032
    ** [sqlite3_vtab_config](db,SQLITE_VTAB_DIRECTONLY) from within the
    10033
    ** the [xConnect] or [xCreate] methods of a [virtual table] implementation
    10034
    ** prohibits that virtual table from being used from within triggers and
    10035
    ** views.
    10036
    ** </dd>
    10037
    **
    10038
    ** [[SQLITE_VTAB_INNOCUOUS]]<dt>SQLITE_VTAB_INNOCUOUS</dt>
    10039
    ** <dd>Calls of the form
    10040
    ** [sqlite3_vtab_config](db,SQLITE_VTAB_INNOCUOUS) from within the
    10041
    ** [xConnect] or [xCreate] methods of a [virtual table] implementation
    10042
    ** identify that virtual table as being safe to use from within triggers
    10043
    ** and views.  Conceptually, the SQLITE_VTAB_INNOCUOUS tag means that the
    10044
    ** virtual table can do no serious harm even if it is controlled by a
    10045
    ** malicious hacker.  Developers should avoid setting the SQLITE_VTAB_INNOCUOUS
    10046
    ** flag unless absolutely necessary.
    10047
    ** </dd>
    10048
    **
    10049
    ** [[SQLITE_VTAB_USES_ALL_SCHEMAS]]<dt>SQLITE_VTAB_USES_ALL_SCHEMAS</dt>
    10050
    ** <dd>Calls of the form
    10051
    ** [sqlite3_vtab_config](db,SQLITE_VTAB_USES_ALL_SCHEMA) from within the
    10052
    ** the [xConnect] or [xCreate] methods of a [virtual table] implementation
    10053
    ** instruct the query planner to begin at least a read transaction on
    10054
    ** all schemas ("main", "temp", and any ATTACH-ed databases) whenever the
    10055
    ** virtual table is used.
    10056
    ** </dd>
    10057
    ** </dl>
    10058
    */
    10059
    #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1
    10060
    #define SQLITE_VTAB_INNOCUOUS          2
    10061
    #define SQLITE_VTAB_DIRECTONLY         3
    10062
    #define SQLITE_VTAB_USES_ALL_SCHEMAS   4
    10063
    10064
    /*
    10065
    ** CAPI3REF: Determine The Virtual Table Conflict Policy
    10066
    **
    10067
    ** This function may only be called from within a call to the [xUpdate] method
    10068
    ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The
    10069
    ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL],
    10070
    ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode
    10071
    ** of the SQL statement that triggered the call to the [xUpdate] method of the
    10072
    ** [virtual table].
    10073
    */
    10074
    SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *);
    10075
    10076
    /*
    10077
    ** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE
    10078
    **
    10079
    ** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn]
    10080
    ** method of a [virtual table], then it might return true if the
    10081
    ** column is being fetched as part of an UPDATE operation during which the
    10082
    ** column value will not change.  The virtual table implementation can use
    10083
    ** this hint as permission to substitute a return value that is less
    10084
    ** expensive to compute and that the corresponding
    10085
    ** [xUpdate] method understands as a "no-change" value.
    10086
    **
    10087
    ** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that
    10088
    ** the column is not changed by the UPDATE statement, then the xColumn
    10089
    ** method can optionally return without setting a result, without calling
    10090
    ** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces].
    10091
    ** In that case, [sqlite3_value_nochange(X)] will return true for the
    10092
    ** same column in the [xUpdate] method.
    10093
    **
    10094
    ** The sqlite3_vtab_nochange() routine is an optimization.  Virtual table
    10095
    ** implementations should continue to give a correct answer even if the
    10096
    ** sqlite3_vtab_nochange() interface were to always return false.  In the
    10097
    ** current implementation, the sqlite3_vtab_nochange() interface does always
    10098
    ** returns false for the enhanced [UPDATE FROM] statement.
    10099
    */
    10100
    SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*);
    10101
    10102
    /*
    10103
    ** CAPI3REF: Determine The Collation For a Virtual Table Constraint
    10104
    ** METHOD: sqlite3_index_info
    10105
    **
    10106
    ** This function may only be called from within a call to the [xBestIndex]
    10107
    ** method of a [virtual table].  This function returns a pointer to a string
    10108
    ** that is the name of the appropriate collation sequence to use for text
    10109
    ** comparisons on the constraint identified by its arguments.
    10110
    **
    10111
    ** The first argument must be the pointer to the [sqlite3_index_info] object
    10112
    ** that is the first parameter to the xBestIndex() method. The second argument
    10113
    ** must be an index into the aConstraint[] array belonging to the
    10114
    ** sqlite3_index_info structure passed to xBestIndex.
    10115
    **
    10116
    ** Important:
    10117
    ** The first parameter must be the same pointer that is passed into the
    10118
    ** xBestMethod() method.  The first parameter may not be a pointer to a
    10119
    ** different [sqlite3_index_info] object, even an exact copy.
    10120
    **
    10121
    ** The return value is computed as follows:
    10122
    **
    10123
    ** <ol>
    10124
    ** <li><p> If the constraint comes from a WHERE clause expression that contains
    10125
    **         a [COLLATE operator], then the name of the collation specified by
    10126
    **         that COLLATE operator is returned.
    10127
    ** <li><p> If there is no COLLATE operator, but the column that is the subject
    10128
    **         of the constraint specifies an alternative collating sequence via
    10129
    **         a [COLLATE clause] on the column definition within the CREATE TABLE
    10130
    **         statement that was passed into [sqlite3_declare_vtab()], then the
    10131
    **         name of that alternative collating sequence is returned.
    10132
    ** <li><p> Otherwise, "BINARY" is returned.
    10133
    ** </ol>
    10134
    */
    10135
    SQLITE_API const char *sqlite3_vtab_collation(sqlite3_index_info*,int);
    10136
    10137
    /*
    10138
    ** CAPI3REF: Determine if a virtual table query is DISTINCT
    10139
    ** METHOD: sqlite3_index_info
    10140
    **
    10141
    ** This API may only be used from within an [xBestIndex|xBestIndex method]
    10142
    ** of a [virtual table] implementation. The result of calling this
    10143
    ** interface from outside of xBestIndex() is undefined and probably harmful.
    10144
    **
    10145
    ** ^The sqlite3_vtab_distinct() interface returns an integer between 0 and
    10146
    ** 3.  The integer returned by sqlite3_vtab_distinct()
    10147
    ** gives the virtual table additional information about how the query
    10148
    ** planner wants the output to be ordered. As long as the virtual table
    10149
    ** can meet the ordering requirements of the query planner, it may set
    10150
    ** the "orderByConsumed" flag.
    10151
    **
    10152
    ** <ol><li value="0"><p>
    10153
    ** ^If the sqlite3_vtab_distinct() interface returns 0, that means
    10154
    ** that the query planner needs the virtual table to return all rows in the
    10155
    ** sort order defined by the "nOrderBy" and "aOrderBy" fields of the
    10156
    ** [sqlite3_index_info] object.  This is the default expectation.  If the
    10157
    ** virtual table outputs all rows in sorted order, then it is always safe for
    10158
    ** the xBestIndex method to set the "orderByConsumed" flag, regardless of
    10159
    ** the return value from sqlite3_vtab_distinct().
    10160
    ** <li value="1"><p>
    10161
    ** ^(If the sqlite3_vtab_distinct() interface returns 1, that means
    10162
    ** that the query planner does not need the rows to be returned in sorted order
    10163
    ** as long as all rows with the same values in all columns identified by the
    10164
    ** "aOrderBy" field are adjacent.)^  This mode is used when the query planner
    10165
    ** is doing a GROUP BY.
    10166
    ** <li value="2"><p>
    10167
    ** ^(If the sqlite3_vtab_distinct() interface returns 2, that means
    10168
    ** that the query planner does not need the rows returned in any particular
    10169
    ** order, as long as rows with the same values in all columns identified
    10170
    ** by "aOrderBy" are adjacent.)^  ^(Furthermore, when two or more rows
    10171
    ** contain the same values for all columns identified by "colUsed", all but
    10172
    ** one such row may optionally be omitted from the result.)^
    10173
    ** The virtual table is not required to omit rows that are duplicates
    10174
    ** over the "colUsed" columns, but if the virtual table can do that without
    10175
    ** too much extra effort, it could potentially help the query to run faster.
    10176
    ** This mode is used for a DISTINCT query.
    10177
    ** <li value="3"><p>
    10178
    ** ^(If the sqlite3_vtab_distinct() interface returns 3, that means the
    10179
    ** virtual table must return rows in the order defined by "aOrderBy" as
    10180
    ** if the sqlite3_vtab_distinct() interface had returned 0.  However if
    10181
    ** two or more rows in the result have the same values for all columns
    10182
    ** identified by "colUsed", then all but one such row may optionally be
    10183
    ** omitted.)^  Like when the return value is 2, the virtual table
    10184
    ** is not required to omit rows that are duplicates over the "colUsed"
    10185
    ** columns, but if the virtual table can do that without
    10186
    ** too much extra effort, it could potentially help the query to run faster.
    10187
    ** This mode is used for queries
    10188
    ** that have both DISTINCT and ORDER BY clauses.
    10189
    ** </ol>
    10190
    **
    10191
    ** <p>The following table summarizes the conditions under which the
    10192
    ** virtual table is allowed to set the "orderByConsumed" flag based on
    10193
    ** the value returned by sqlite3_vtab_distinct().  This table is a
    10194
    ** restatement of the previous four paragraphs:
    10195
    **
    10196
    ** <table border=1 cellspacing=0 cellpadding=10 width="90%">
    10197
    ** <tr>
    10198
    ** <td valign="top">sqlite3_vtab_distinct() return value
    10199
    ** <td valign="top">Rows are returned in aOrderBy order
    10200
    ** <td valign="top">Rows with the same value in all aOrderBy columns are adjacent
    10201
    ** <td valign="top">Duplicates over all colUsed columns may be omitted
    10202
    ** <tr><td>0<td>yes<td>yes<td>no
    10203
    ** <tr><td>1<td>no<td>yes<td>no
    10204
    ** <tr><td>2<td>no<td>yes<td>yes
    10205
    ** <tr><td>3<td>yes<td>yes<td>yes
    10206
    ** </table>
    10207
    **
    10208
    ** ^For the purposes of comparing virtual table output values to see if the
    10209
    ** values are the same value for sorting purposes, two NULL values are considered
    10210
    ** to be the same.  In other words, the comparison operator is "IS"
    10211
    ** (or "IS NOT DISTINCT FROM") and not "==".
    10212
    **
    10213
    ** If a virtual table implementation is unable to meet the requirements
    10214
    ** specified above, then it must not set the "orderByConsumed" flag in the
    10215
    ** [sqlite3_index_info] object or an incorrect answer may result.
    10216
    **
    10217
    ** ^A virtual table implementation is always free to return rows in any order
    10218
    ** it wants, as long as the "orderByConsumed" flag is not set.  ^When the
    10219
    ** "orderByConsumed" flag is unset, the query planner will add extra
    10220
    ** [bytecode] to ensure that the final results returned by the SQL query are
    10221
    ** ordered correctly.  The use of the "orderByConsumed" flag and the
    10222
    ** sqlite3_vtab_distinct() interface is merely an optimization.  ^Careful
    10223
    ** use of the sqlite3_vtab_distinct() interface and the "orderByConsumed"
    10224
    ** flag might help queries against a virtual table to run faster.  Being
    10225
    ** overly aggressive and setting the "orderByConsumed" flag when it is not
    10226
    ** valid to do so, on the other hand, might cause SQLite to return incorrect
    10227
    ** results.
    10228
    */
    10229
    SQLITE_API int sqlite3_vtab_distinct(sqlite3_index_info*);
    10230
    10231
    /*
    10232
    ** CAPI3REF: Identify and handle IN constraints in xBestIndex
    10233
    **
    10234
    ** This interface may only be used from within an
    10235
    ** [xBestIndex|xBestIndex() method] of a [virtual table] implementation.
    10236
    ** The result of invoking this interface from any other context is
    10237
    ** undefined and probably harmful.
    10238
    **
    10239
    ** ^(A constraint on a virtual table of the form
    10240
    ** "[IN operator|column IN (...)]" is
    10241
    ** communicated to the xBestIndex method as a
    10242
    ** [SQLITE_INDEX_CONSTRAINT_EQ] constraint.)^  If xBestIndex wants to use
    10243
    ** this constraint, it must set the corresponding
    10244
    ** aConstraintUsage[].argvIndex to a positive integer.  ^(Then, under
    10245
    ** the usual mode of handling IN operators, SQLite generates [bytecode]
    10246
    ** that invokes the [xFilter|xFilter() method] once for each value
    10247
    ** on the right-hand side of the IN operator.)^  Thus the virtual table
    10248
    ** only sees a single value from the right-hand side of the IN operator
    10249
    ** at a time.
    10250
    **
    10251
    ** In some cases, however, it would be advantageous for the virtual
    10252
    ** table to see all values on the right-hand of the IN operator all at
    10253
    ** once.  The sqlite3_vtab_in() interfaces facilitates this in two ways:
    10254
    **
    10255
    ** <ol>
    10256
    ** <li><p>
    10257
    **   ^A call to sqlite3_vtab_in(P,N,-1) will return true (non-zero)
    10258
    **   if and only if the [sqlite3_index_info|P->aConstraint][N] constraint
    10259
    **   is an [IN operator] that can be processed all at once.  ^In other words,
    10260
    **   sqlite3_vtab_in() with -1 in the third argument is a mechanism
    10261
    **   by which the virtual table can ask SQLite if all-at-once processing
    10262
    **   of the IN operator is even possible.
    10263
    **
    10264
    ** <li><p>
    10265
    **   ^A call to sqlite3_vtab_in(P,N,F) with F==1 or F==0 indicates
    10266
    **   to SQLite that the virtual table does or does not want to process
    10267
    **   the IN operator all-at-once, respectively.  ^Thus when the third
    10268
    **   parameter (F) is non-negative, this interface is the mechanism by
    10269
    **   which the virtual table tells SQLite how it wants to process the
    10270
    **   IN operator.
    10271
    ** </ol>
    10272
    **
    10273
    ** ^The sqlite3_vtab_in(P,N,F) interface can be invoked multiple times
    10274
    ** within the same xBestIndex method call.  ^For any given P,N pair,
    10275
    ** the return value from sqlite3_vtab_in(P,N,F) will always be the same
    10276
    ** within the same xBestIndex call.  ^If the interface returns true
    10277
    ** (non-zero), that means that the constraint is an IN operator
    10278
    ** that can be processed all-at-once.  ^If the constraint is not an IN
    10279
    ** operator or cannot be processed all-at-once, then the interface returns
    10280
    ** false.
    10281
    **
    10282
    ** ^(All-at-once processing of the IN operator is selected if both of the
    10283
    ** following conditions are met:
    10284
    **
    10285
    ** <ol>
    10286
    ** <li><p> The P->aConstraintUsage[N].argvIndex value is set to a positive
    10287
    ** integer.  This is how the virtual table tells SQLite that it wants to
    10288
    ** use the N-th constraint.
    10289
    **
    10290
    ** <li><p> The last call to sqlite3_vtab_in(P,N,F) for which F was
    10291
    ** non-negative had F>=1.
    10292
    ** </ol>)^
    10293
    **
    10294
    ** ^If either or both of the conditions above are false, then SQLite uses
    10295
    ** the traditional one-at-a-time processing strategy for the IN constraint.
    10296
    ** ^If both conditions are true, then the argvIndex-th parameter to the
    10297
    ** xFilter method will be an [sqlite3_value] that appears to be NULL,
    10298
    ** but which can be passed to [sqlite3_vtab_in_first()] and
    10299
    ** [sqlite3_vtab_in_next()] to find all values on the right-hand side
    10300
    ** of the IN constraint.
    10301
    */
    10302
    SQLITE_API int sqlite3_vtab_in(sqlite3_index_info*, int iCons, int bHandle);
    10303
    10304
    /*
    10305
    ** CAPI3REF: Find all elements on the right-hand side of an IN constraint.
    10306
    **
    10307
    ** These interfaces are only useful from within the
    10308
    ** [xFilter|xFilter() method] of a [virtual table] implementation.
    10309
    ** The result of invoking these interfaces from any other context
    10310
    ** is undefined and probably harmful.
    10311
    **
    10312
    ** The X parameter in a call to sqlite3_vtab_in_first(X,P) or
    10313
    ** sqlite3_vtab_in_next(X,P) should be one of the parameters to the
    10314
    ** xFilter method which invokes these routines, and specifically
    10315
    ** a parameter that was previously selected for all-at-once IN constraint
    10316
    ** processing using the [sqlite3_vtab_in()] interface in the
    10317
    ** [xBestIndex|xBestIndex method].  ^(If the X parameter is not
    10318
    ** an xFilter argument that was selected for all-at-once IN constraint
    10319
    ** processing, then these routines return [SQLITE_ERROR].)^
    10320
    **
    10321
    ** ^(Use these routines to access all values on the right-hand side
    10322
    ** of the IN constraint using code like the following:
    10323
    **
    10324
    ** <blockquote><pre>
    10325
    ** &nbsp;  for(rc=sqlite3_vtab_in_first(pList, &pVal);
    10326
    ** &nbsp;      rc==SQLITE_OK && pVal;
    10327
    ** &nbsp;      rc=sqlite3_vtab_in_next(pList, &pVal)
    10328
    ** &nbsp;  ){
    10329
    ** &nbsp;    // do something with pVal
    10330
    ** &nbsp;  }
    10331
    ** &nbsp;  if( rc!=SQLITE_OK ){
    10332
    ** &nbsp;    // an error has occurred
    10333
    ** &nbsp;  }
    10334
    ** </pre></blockquote>)^
    10335
    **
    10336
    ** ^On success, the sqlite3_vtab_in_first(X,P) and sqlite3_vtab_in_next(X,P)
    10337
    ** routines return SQLITE_OK and set *P to point to the first or next value
    10338
    ** on the RHS of the IN constraint.  ^If there are no more values on the
    10339
    ** right hand side of the IN constraint, then *P is set to NULL and these
    10340
    ** routines return [SQLITE_DONE].  ^The return value might be
    10341
    ** some other value, such as SQLITE_NOMEM, in the event of a malfunction.
    10342
    **
    10343
    ** The *ppOut values returned by these routines are only valid until the
    10344
    ** next call to either of these routines or until the end of the xFilter
    10345
    ** method from which these routines were called.  If the virtual table
    10346
    ** implementation needs to retain the *ppOut values for longer, it must make
    10347
    ** copies.  The *ppOut values are [protected sqlite3_value|protected].
    10348
    */
    10349
    SQLITE_API int sqlite3_vtab_in_first(sqlite3_value *pVal, sqlite3_value **ppOut);
    10350
    SQLITE_API int sqlite3_vtab_in_next(sqlite3_value *pVal, sqlite3_value **ppOut);
    10351
    10352
    /*
    10353
    ** CAPI3REF: Constraint values in xBestIndex()
    10354
    ** METHOD: sqlite3_index_info
    10355
    **
    10356
    ** This API may only be used from within the [xBestIndex|xBestIndex method]
    10357
    ** of a [virtual table] implementation. The result of calling this interface
    10358
    ** from outside of an xBestIndex method are undefined and probably harmful.
    10359
    **
    10360
    ** ^When the sqlite3_vtab_rhs_value(P,J,V) interface is invoked from within
    10361
    ** the [xBestIndex] method of a [virtual table] implementation, with P being
    10362
    ** a copy of the [sqlite3_index_info] object pointer passed into xBestIndex and
    10363
    ** J being a 0-based index into P->aConstraint[], then this routine
    10364
    ** attempts to set *V to the value of the right-hand operand of
    10365
    ** that constraint if the right-hand operand is known.  ^If the
    10366
    ** right-hand operand is not known, then *V is set to a NULL pointer.
    10367
    ** ^The sqlite3_vtab_rhs_value(P,J,V) interface returns SQLITE_OK if
    10368
    ** and only if *V is set to a value.  ^The sqlite3_vtab_rhs_value(P,J,V)
    10369
    ** inteface returns SQLITE_NOTFOUND if the right-hand side of the J-th
    10370
    ** constraint is not available.  ^The sqlite3_vtab_rhs_value() interface
    10371
    ** can return a result code other than SQLITE_OK or SQLITE_NOTFOUND if
    10372
    ** something goes wrong.
    10373
    **
    10374
    ** The sqlite3_vtab_rhs_value() interface is usually only successful if
    10375
    ** the right-hand operand of a constraint is a literal value in the original
    10376
    ** SQL statement.  If the right-hand operand is an expression or a reference
    10377
    ** to some other column or a [host parameter], then sqlite3_vtab_rhs_value()
    10378
    ** will probably return [SQLITE_NOTFOUND].
    10379
    **
    10380
    ** ^(Some constraints, such as [SQLITE_INDEX_CONSTRAINT_ISNULL] and
    10381
    ** [SQLITE_INDEX_CONSTRAINT_ISNOTNULL], have no right-hand operand.  For such
    10382
    ** constraints, sqlite3_vtab_rhs_value() always returns SQLITE_NOTFOUND.)^
    10383
    **
    10384
    ** ^The [sqlite3_value] object returned in *V is a protected sqlite3_value
    10385
    ** and remains valid for the duration of the xBestIndex method call.
    10386
    ** ^When xBestIndex returns, the sqlite3_value object returned by
    10387
    ** sqlite3_vtab_rhs_value() is automatically deallocated.
    10388
    **
    10389
    ** The "_rhs_" in the name of this routine is an abbreviation for
    10390
    ** "Right-Hand Side".
    10391
    */
    10392
    SQLITE_API int sqlite3_vtab_rhs_value(sqlite3_index_info*, int, sqlite3_value **ppVal);
    10393
    10394
    /*
    10395
    ** CAPI3REF: Conflict resolution modes
    10396
    ** KEYWORDS: {conflict resolution mode}
    10397
    **
    10398
    ** These constants are returned by [sqlite3_vtab_on_conflict()] to
    10399
    ** inform a [virtual table] implementation of the [ON CONFLICT] mode
    10400
    ** for the SQL statement being evaluated.
    10401
    **
    10402
    ** Note that the [SQLITE_IGNORE] constant is also used as a potential
    10403
    ** return value from the [sqlite3_set_authorizer()] callback and that
    10404
    ** [SQLITE_ABORT] is also a [result code].
    10405
    */
    10406
    #define SQLITE_ROLLBACK 1
    10407
    /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */
    10408
    #define SQLITE_FAIL     3
    10409
    /* #define SQLITE_ABORT 4  // Also an error code */
    10410
    #define SQLITE_REPLACE  5
    10411
    10412
    /*
    10413
    ** CAPI3REF: Prepared Statement Scan Status Opcodes
    10414
    ** KEYWORDS: {scanstatus options}
    10415
    **
    10416
    ** The following constants can be used for the T parameter to the
    10417
    ** [sqlite3_stmt_scanstatus(S,X,T,V)] interface.  Each constant designates a
    10418
    ** different metric for sqlite3_stmt_scanstatus() to return.
    10419
    **
    10420
    ** When the value returned to V is a string, space to hold that string is
    10421
    ** managed by the prepared statement S and will be automatically freed when
    10422
    ** S is finalized.
    10423
    **
    10424
    ** Not all values are available for all query elements. When a value is
    10425
    ** not available, the output variable is set to -1 if the value is numeric,
    10426
    ** or to NULL if it is a string (SQLITE_SCANSTAT_NAME).
    10427
    **
    10428
    ** <dl>
    10429
    ** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt>
    10430
    ** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be
    10431
    ** set to the total number of times that the X-th loop has run.</dd>
    10432
    **
    10433
    ** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt>
    10434
    ** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be set
    10435
    ** to the total number of rows examined by all iterations of the X-th loop.</dd>
    10436
    **
    10437
    ** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt>
    10438
    ** <dd>^The "double" variable pointed to by the V parameter will be set to the
    10439
    ** query planner's estimate for the average number of rows output from each
    10440
    ** iteration of the X-th loop.  If the query planner's estimate was accurate,
    10441
    ** then this value will approximate the quotient NVISIT/NLOOP and the
    10442
    ** product of this value for all prior loops with the same SELECTID will
    10443
    ** be the NLOOP value for the current loop.</dd>
    10444
    **
    10445
    ** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt>
    10446
    ** <dd>^The "const char *" variable pointed to by the V parameter will be set
    10447
    ** to a zero-terminated UTF-8 string containing the name of the index or table
    10448
    ** used for the X-th loop.</dd>
    10449
    **
    10450
    ** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt>
    10451
    ** <dd>^The "const char *" variable pointed to by the V parameter will be set
    10452
    ** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN]
    10453
    ** description for the X-th loop.</dd>
    10454
    **
    10455
    ** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECTID</dt>
    10456
    ** <dd>^The "int" variable pointed to by the V parameter will be set to the
    10457
    ** id for the X-th query plan element. The id value is unique within the
    10458
    ** statement. The select-id is the same value as is output in the first
    10459
    ** column of an [EXPLAIN QUERY PLAN] query.</dd>
    10460
    **
    10461
    ** [[SQLITE_SCANSTAT_PARENTID]] <dt>SQLITE_SCANSTAT_PARENTID</dt>
    10462
    ** <dd>The "int" variable pointed to by the V parameter will be set to the
    10463
    ** id of the parent of the current query element, if applicable, or
    10464
    ** to zero if the query element has no parent. This is the same value as
    10465
    ** returned in the second column of an [EXPLAIN QUERY PLAN] query.</dd>
    10466
    **
    10467
    ** [[SQLITE_SCANSTAT_NCYCLE]] <dt>SQLITE_SCANSTAT_NCYCLE</dt>
    10468
    ** <dd>The sqlite3_int64 output value is set to the number of cycles,
    10469
    ** according to the processor time-stamp counter, that elapsed while the
    10470
    ** query element was being processed. This value is not available for
    10471
    ** all query elements - if it is unavailable the output variable is
    10472
    ** set to -1.</dd>
    10473
    ** </dl>
    10474
    */
    10475
    #define SQLITE_SCANSTAT_NLOOP    0
    10476
    #define SQLITE_SCANSTAT_NVISIT   1
    10477
    #define SQLITE_SCANSTAT_EST      2
    10478
    #define SQLITE_SCANSTAT_NAME     3
    10479
    #define SQLITE_SCANSTAT_EXPLAIN  4
    10480
    #define SQLITE_SCANSTAT_SELECTID 5
    10481
    #define SQLITE_SCANSTAT_PARENTID 6
    10482
    #define SQLITE_SCANSTAT_NCYCLE   7
    10483
    10484
    /*
    10485
    ** CAPI3REF: Prepared Statement Scan Status
    10486
    ** METHOD: sqlite3_stmt
    10487
    **
    10488
    ** These interfaces return information about the predicted and measured
    10489
    ** performance for pStmt.  Advanced applications can use this
    10490
    ** interface to compare the predicted and the measured performance and
    10491
    ** issue warnings and/or rerun [ANALYZE] if discrepancies are found.
    10492
    **
    10493
    ** Since this interface is expected to be rarely used, it is only
    10494
    ** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS]
    10495
    ** compile-time option.
    10496
    **
    10497
    ** The "iScanStatusOp" parameter determines which status information to return.
    10498
    ** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior
    10499
    ** of this interface is undefined. ^The requested measurement is written into
    10500
    ** a variable pointed to by the "pOut" parameter.
    10501
    **
    10502
    ** The "flags" parameter must be passed a mask of flags. At present only
    10503
    ** one flag is defined - SQLITE_SCANSTAT_COMPLEX. If SQLITE_SCANSTAT_COMPLEX
    10504
    ** is specified, then status information is available for all elements
    10505
    ** of a query plan that are reported by "EXPLAIN QUERY PLAN" output. If
    10506
    ** SQLITE_SCANSTAT_COMPLEX is not specified, then only query plan elements
    10507
    ** that correspond to query loops (the "SCAN..." and "SEARCH..." elements of
    10508
    ** the EXPLAIN QUERY PLAN output) are available. Invoking API
    10509
    ** sqlite3_stmt_scanstatus() is equivalent to calling
    10510
    ** sqlite3_stmt_scanstatus_v2() with a zeroed flags parameter.
    10511
    **
    10512
    ** Parameter "idx" identifies the specific query element to retrieve statistics
    10513
    ** for. Query elements are numbered starting from zero. A value of -1 may
    10514
    ** retrieve statistics for the entire query. ^If idx is out of range
    10515
    ** - less than -1 or greater than or equal to the total number of query
    10516
    ** elements used to implement the statement - a non-zero value is returned and
    10517
    ** the variable that pOut points to is unchanged.
    10518
    **
    10519
    ** See also: [sqlite3_stmt_scanstatus_reset()]
    10520
    */
    10521
    SQLITE_API int sqlite3_stmt_scanstatus(
    10522
      sqlite3_stmt *pStmt,      /* Prepared statement for which info desired */
    10523
      int idx,                  /* Index of loop to report on */
    10524
      int iScanStatusOp,        /* Information desired.  SQLITE_SCANSTAT_* */
    10525
      void *pOut                /* Result written here */
    10526
    );
    10527
    SQLITE_API int sqlite3_stmt_scanstatus_v2(
    10528
      sqlite3_stmt *pStmt,      /* Prepared statement for which info desired */
    10529
      int idx,                  /* Index of loop to report on */
    10530
      int iScanStatusOp,        /* Information desired.  SQLITE_SCANSTAT_* */
    10531
      int flags,                /* Mask of flags defined below */
    10532
      void *pOut                /* Result written here */
    10533
    );
    10534
    10535
    /*
    10536
    ** CAPI3REF: Prepared Statement Scan Status
    10537
    ** KEYWORDS: {scan status flags}
    10538
    */
    10539
    #define SQLITE_SCANSTAT_COMPLEX 0x0001
    10540
    10541
    /*
    10542
    ** CAPI3REF: Zero Scan-Status Counters
    10543
    ** METHOD: sqlite3_stmt
    10544
    **
    10545
    ** ^Zero all [sqlite3_stmt_scanstatus()] related event counters.
    10546
    **
    10547
    ** This API is only available if the library is built with pre-processor
    10548
    ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined.
    10549
    */
    10550
    SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*);
    10551
    10552
    /*
    10553
    ** CAPI3REF: Flush caches to disk mid-transaction
    10554
    ** METHOD: sqlite3
    10555
    **
    10556
    ** ^If a write-transaction is open on [database connection] D when the
    10557
    ** [sqlite3_db_cacheflush(D)] interface is invoked, any dirty
    10558
    ** pages in the pager-cache that are not currently in use are written out
    10559
    ** to disk. A dirty page may be in use if a database cursor created by an
    10560
    ** active SQL statement is reading from it, or if it is page 1 of a database
    10561
    ** file (page 1 is always "in use").  ^The [sqlite3_db_cacheflush(D)]
    10562
    ** interface flushes caches for all schemas - "main", "temp", and
    10563
    ** any [attached] databases.
    10564
    **
    10565
    ** ^If this function needs to obtain extra database locks before dirty pages
    10566
    ** can be flushed to disk, it does so. ^If those locks cannot be obtained
    10567
    ** immediately and there is a busy-handler callback configured, it is invoked
    10568
    ** in the usual manner. ^If the required lock still cannot be obtained, then
    10569
    ** the database is skipped and an attempt made to flush any dirty pages
    10570
    ** belonging to the next (if any) database. ^If any databases are skipped
    10571
    ** because locks cannot be obtained, but no other error occurs, this
    10572
    ** function returns SQLITE_BUSY.
    10573
    **
    10574
    ** ^If any other error occurs while flushing dirty pages to disk (for
    10575
    ** example an IO error or out-of-memory condition), then processing is
    10576
    ** abandoned and an SQLite [error code] is returned to the caller immediately.
    10577
    **
    10578
    ** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK.
    10579
    **
    10580
    ** ^This function does not set the database handle error code or message
    10581
    ** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions.
    10582
    */
    10583
    SQLITE_API int sqlite3_db_cacheflush(sqlite3*);
    10584
    10585
    /*
    10586
    ** CAPI3REF: The pre-update hook.
    10587
    ** METHOD: sqlite3
    10588
    **
    10589
    ** ^These interfaces are only available if SQLite is compiled using the
    10590
    ** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option.
    10591
    **
    10592
    ** ^The [sqlite3_preupdate_hook()] interface registers a callback function
    10593
    ** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation
    10594
    ** on a database table.
    10595
    ** ^At most one preupdate hook may be registered at a time on a single
    10596
    ** [database connection]; each call to [sqlite3_preupdate_hook()] overrides
    10597
    ** the previous setting.
    10598
    ** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()]
    10599
    ** with a NULL pointer as the second parameter.
    10600
    ** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as
    10601
    ** the first parameter to callbacks.
    10602
    **
    10603
    ** ^The preupdate hook only fires for changes to real database tables; the
    10604
    ** preupdate hook is not invoked for changes to [virtual tables] or to
    10605
    ** system tables like sqlite_sequence or sqlite_stat1.
    10606
    **
    10607
    ** ^The second parameter to the preupdate callback is a pointer to
    10608
    ** the [database connection] that registered the preupdate hook.
    10609
    ** ^The third parameter to the preupdate callback is one of the constants
    10610
    ** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the
    10611
    ** kind of update operation that is about to occur.
    10612
    ** ^(The fourth parameter to the preupdate callback is the name of the
    10613
    ** database within the database connection that is being modified.  This
    10614
    ** will be "main" for the main database or "temp" for TEMP tables or
    10615
    ** the name given after the AS keyword in the [ATTACH] statement for attached
    10616
    ** databases.)^
    10617
    ** ^The fifth parameter to the preupdate callback is the name of the
    10618
    ** table that is being modified.
    10619
    **
    10620
    ** For an UPDATE or DELETE operation on a [rowid table], the sixth
    10621
    ** parameter passed to the preupdate callback is the initial [rowid] of the
    10622
    ** row being modified or deleted. For an INSERT operation on a rowid table,
    10623
    ** or any operation on a WITHOUT ROWID table, the value of the sixth
    10624
    ** parameter is undefined. For an INSERT or UPDATE on a rowid table the
    10625
    ** seventh parameter is the final rowid value of the row being inserted
    10626
    ** or updated. The value of the seventh parameter passed to the callback
    10627
    ** function is not defined for operations on WITHOUT ROWID tables, or for
    10628
    ** DELETE operations on rowid tables.
    10629
    **
    10630
    ** ^The sqlite3_preupdate_hook(D,C,P) function returns the P argument from
    10631
    ** the previous call on the same [database connection] D, or NULL for
    10632
    ** the first call on D.
    10633
    **
    10634
    ** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()],
    10635
    ** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces
    10636
    ** provide additional information about a preupdate event. These routines
    10637
    ** may only be called from within a preupdate callback.  Invoking any of
    10638
    ** these routines from outside of a preupdate callback or with a
    10639
    ** [database connection] pointer that is different from the one supplied
    10640
    ** to the preupdate callback results in undefined and probably undesirable
    10641
    ** behavior.
    10642
    **
    10643
    ** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns
    10644
    ** in the row that is being inserted, updated, or deleted.
    10645
    **
    10646
    ** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to
    10647
    ** a [protected sqlite3_value] that contains the value of the Nth column of
    10648
    ** the table row before it is updated.  The N parameter must be between 0
    10649
    ** and one less than the number of columns or the behavior will be
    10650
    ** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE
    10651
    ** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the
    10652
    ** behavior is undefined.  The [sqlite3_value] that P points to
    10653
    ** will be destroyed when the preupdate callback returns.
    10654
    **
    10655
    ** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to
    10656
    ** a [protected sqlite3_value] that contains the value of the Nth column of
    10657
    ** the table row after it is updated.  The N parameter must be between 0
    10658
    ** and one less than the number of columns or the behavior will be
    10659
    ** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE
    10660
    ** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the
    10661
    ** behavior is undefined.  The [sqlite3_value] that P points to
    10662
    ** will be destroyed when the preupdate callback returns.
    10663
    **
    10664
    ** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate
    10665
    ** callback was invoked as a result of a direct insert, update, or delete
    10666
    ** operation; or 1 for inserts, updates, or deletes invoked by top-level
    10667
    ** triggers; or 2 for changes resulting from triggers called by top-level
    10668
    ** triggers; and so forth.
    10669
    **
    10670
    ** When the [sqlite3_blob_write()] API is used to update a blob column,
    10671
    ** the pre-update hook is invoked with SQLITE_DELETE, because
    10672
    ** the new values are not yet available. In this case, when a
    10673
    ** callback made with op==SQLITE_DELETE is actually a write using the
    10674
    ** sqlite3_blob_write() API, the [sqlite3_preupdate_blobwrite()] returns
    10675
    ** the index of the column being written. In other cases, where the
    10676
    ** pre-update hook is being invoked for some other reason, including a
    10677
    ** regular DELETE, sqlite3_preupdate_blobwrite() returns -1.
    10678
    **
    10679
    ** See also:  [sqlite3_update_hook()]
    10680
    */
    10681
    #if defined(SQLITE_ENABLE_PREUPDATE_HOOK)
    10682
    SQLITE_API void *sqlite3_preupdate_hook(
    10683
      sqlite3 *db,
    10684
      void(*xPreUpdate)(
    10685
        void *pCtx,                   /* Copy of third arg to preupdate_hook() */
    10686
        sqlite3 *db,                  /* Database handle */
    10687
        int op,                       /* SQLITE_UPDATE, DELETE or INSERT */
    10688
        char const *zDb,              /* Database name */
    10689
        char const *zName,            /* Table name */
    10690
        sqlite3_int64 iKey1,          /* Rowid of row about to be deleted/updated */
    10691
        sqlite3_int64 iKey2           /* New rowid value (for a rowid UPDATE) */
    10692
      ),
    10693
      void*
    10694
    );
    10695
    SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **);
    10696
    SQLITE_API int sqlite3_preupdate_count(sqlite3 *);
    10697
    SQLITE_API int sqlite3_preupdate_depth(sqlite3 *);
    10698
    SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **);
    10699
    SQLITE_API int sqlite3_preupdate_blobwrite(sqlite3 *);
    10700
    #endif
    10701
    10702
    /*
    10703
    ** CAPI3REF: Low-level system error code
    10704
    ** METHOD: sqlite3
    10705
    **
    10706
    ** ^Attempt to return the underlying operating system error code or error
    10707
    ** number that caused the most recent I/O error or failure to open a file.
    10708
    ** The return value is OS-dependent.  For example, on unix systems, after
    10709
    ** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be
    10710
    ** called to get back the underlying "errno" that caused the problem, such
    10711
    ** as ENOSPC, EAUTH, EISDIR, and so forth.
    10712
    */
    10713
    SQLITE_API int sqlite3_system_errno(sqlite3*);
    10714
    10715
    /*
    10716
    ** CAPI3REF: Database Snapshot
    10717
    ** KEYWORDS: {snapshot} {sqlite3_snapshot}
    10718
    **
    10719
    ** An instance of the snapshot object records the state of a [WAL mode]
    10720
    ** database for some specific point in history.
    10721
    **
    10722
    ** In [WAL mode], multiple [database connections] that are open on the
    10723
    ** same database file can each be reading a different historical version
    10724
    ** of the database file.  When a [database connection] begins a read
    10725
    ** transaction, that connection sees an unchanging copy of the database
    10726
    ** as it existed for the point in time when the transaction first started.
    10727
    ** Subsequent changes to the database from other connections are not seen
    10728
    ** by the reader until a new read transaction is started.
    10729
    **
    10730
    ** The sqlite3_snapshot object records state information about an historical
    10731
    ** version of the database file so that it is possible to later open a new read
    10732
    ** transaction that sees that historical version of the database rather than
    10733
    ** the most recent version.
    10734
    */
    10735
    typedef struct sqlite3_snapshot {
    10736
      unsigned char hidden[48];
    10737
    } sqlite3_snapshot;
    10738
    10739
    /*
    10740
    ** CAPI3REF: Record A Database Snapshot
    10741
    ** CONSTRUCTOR: sqlite3_snapshot
    10742
    **
    10743
    ** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a
    10744
    ** new [sqlite3_snapshot] object that records the current state of
    10745
    ** schema S in database connection D.  ^On success, the
    10746
    ** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly
    10747
    ** created [sqlite3_snapshot] object into *P and returns SQLITE_OK.
    10748
    ** If there is not already a read-transaction open on schema S when
    10749
    ** this function is called, one is opened automatically.
    10750
    **
    10751
    ** If a read-transaction is opened by this function, then it is guaranteed
    10752
    ** that the returned snapshot object may not be invalidated by a database
    10753
    ** writer or checkpointer until after the read-transaction is closed. This
    10754
    ** is not guaranteed if a read-transaction is already open when this
    10755
    ** function is called. In that case, any subsequent write or checkpoint
    10756
    ** operation on the database may invalidate the returned snapshot handle,
    10757
    ** even while the read-transaction remains open.
    10758
    **
    10759
    ** The following must be true for this function to succeed. If any of
    10760
    ** the following statements are false when sqlite3_snapshot_get() is
    10761
    ** called, SQLITE_ERROR is returned. The final value of *P is undefined
    10762
    ** in this case.
    10763
    **
    10764
    ** <ul>
    10765
    **   <li> The database handle must not be in [autocommit mode].
    10766
    **
    10767
    **   <li> Schema S of [database connection] D must be a [WAL mode] database.
    10768
    **
    10769
    **   <li> There must not be a write transaction open on schema S of database
    10770
    **        connection D.
    10771
    **
    10772
    **   <li> One or more transactions must have been written to the current wal
    10773
    **        file since it was created on disk (by any connection). This means
    10774
    **        that a snapshot cannot be taken on a wal mode database with no wal
    10775
    **        file immediately after it is first opened. At least one transaction
    10776
    **        must be written to it first.
    10777
    ** </ul>
    10778
    **
    10779
    ** This function may also return SQLITE_NOMEM.  If it is called with the
    10780
    ** database handle in autocommit mode but fails for some other reason,
    10781
    ** whether or not a read transaction is opened on schema S is undefined.
    10782
    **
    10783
    ** The [sqlite3_snapshot] object returned from a successful call to
    10784
    ** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()]
    10785
    ** to avoid a memory leak.
    10786
    **
    10787
    ** The [sqlite3_snapshot_get()] interface is only available when the
    10788
    ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
    10789
    */
    10790
    SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get(
    10791
      sqlite3 *db,
    10792
      const char *zSchema,
    10793
      sqlite3_snapshot **ppSnapshot
    10794
    );
    10795
    10796
    /*
    10797
    ** CAPI3REF: Start a read transaction on an historical snapshot
    10798
    ** METHOD: sqlite3_snapshot
    10799
    **
    10800
    ** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read
    10801
    ** transaction or upgrades an existing one for schema S of
    10802
    ** [database connection] D such that the read transaction refers to
    10803
    ** historical [snapshot] P, rather than the most recent change to the
    10804
    ** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK
    10805
    ** on success or an appropriate [error code] if it fails.
    10806
    **
    10807
    ** ^In order to succeed, the database connection must not be in
    10808
    ** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there
    10809
    ** is already a read transaction open on schema S, then the database handle
    10810
    ** must have no active statements (SELECT statements that have been passed
    10811
    ** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()).
    10812
    ** SQLITE_ERROR is returned if either of these conditions is violated, or
    10813
    ** if schema S does not exist, or if the snapshot object is invalid.
    10814
    **
    10815
    ** ^A call to sqlite3_snapshot_open() will fail to open if the specified
    10816
    ** snapshot has been overwritten by a [checkpoint]. In this case
    10817
    ** SQLITE_ERROR_SNAPSHOT is returned.
    10818
    **
    10819
    ** If there is already a read transaction open when this function is
    10820
    ** invoked, then the same read transaction remains open (on the same
    10821
    ** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT
    10822
    ** is returned. If another error code - for example SQLITE_PROTOCOL or an
    10823
    ** SQLITE_IOERR error code - is returned, then the final state of the
    10824
    ** read transaction is undefined. If SQLITE_OK is returned, then the
    10825
    ** read transaction is now open on database snapshot P.
    10826
    **
    10827
    ** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the
    10828
    ** database connection D does not know that the database file for
    10829
    ** schema S is in [WAL mode].  A database connection might not know
    10830
    ** that the database file is in [WAL mode] if there has been no prior
    10831
    ** I/O on that database connection, or if the database entered [WAL mode]
    10832
    ** after the most recent I/O on the database connection.)^
    10833
    ** (Hint: Run "[PRAGMA application_id]" against a newly opened
    10834
    ** database connection in order to make it ready to use snapshots.)
    10835
    **
    10836
    ** The [sqlite3_snapshot_open()] interface is only available when the
    10837
    ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
    10838
    */
    10839
    SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open(
    10840
      sqlite3 *db,
    10841
      const char *zSchema,
    10842
      sqlite3_snapshot *pSnapshot
    10843
    );
    10844
    10845
    /*
    10846
    ** CAPI3REF: Destroy a snapshot
    10847
    ** DESTRUCTOR: sqlite3_snapshot
    10848
    **
    10849
    ** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P.
    10850
    ** The application must eventually free every [sqlite3_snapshot] object
    10851
    ** using this routine to avoid a memory leak.
    10852
    **
    10853
    ** The [sqlite3_snapshot_free()] interface is only available when the
    10854
    ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
    10855
    */
    10856
    SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*);
    10857
    10858
    /*
    10859
    ** CAPI3REF: Compare the ages of two snapshot handles.
    10860
    ** METHOD: sqlite3_snapshot
    10861
    **
    10862
    ** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages
    10863
    ** of two valid snapshot handles.
    10864
    **
    10865
    ** If the two snapshot handles are not associated with the same database
    10866
    ** file, the result of the comparison is undefined.
    10867
    **
    10868
    ** Additionally, the result of the comparison is only valid if both of the
    10869
    ** snapshot handles were obtained by calling sqlite3_snapshot_get() since the
    10870
    ** last time the wal file was deleted. The wal file is deleted when the
    10871
    ** database is changed back to rollback mode or when the number of database
    10872
    ** clients drops to zero. If either snapshot handle was obtained before the
    10873
    ** wal file was last deleted, the value returned by this function
    10874
    ** is undefined.
    10875
    **
    10876
    ** Otherwise, this API returns a negative value if P1 refers to an older
    10877
    ** snapshot than P2, zero if the two handles refer to the same database
    10878
    ** snapshot, and a positive value if P1 is a newer snapshot than P2.
    10879
    **
    10880
    ** This interface is only available if SQLite is compiled with the
    10881
    ** [SQLITE_ENABLE_SNAPSHOT] option.
    10882
    */
    10883
    SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp(
    10884
      sqlite3_snapshot *p1,
    10885
      sqlite3_snapshot *p2
    10886
    );
    10887
    10888
    /*
    10889
    ** CAPI3REF: Recover snapshots from a wal file
    10890
    ** METHOD: sqlite3_snapshot
    10891
    **
    10892
    ** If a [WAL file] remains on disk after all database connections close
    10893
    ** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control]
    10894
    ** or because the last process to have the database opened exited without
    10895
    ** calling [sqlite3_close()]) and a new connection is subsequently opened
    10896
    ** on that database and [WAL file], the [sqlite3_snapshot_open()] interface
    10897
    ** will only be able to open the last transaction added to the WAL file
    10898
    ** even though the WAL file contains other valid transactions.
    10899
    **
    10900
    ** This function attempts to scan the WAL file associated with database zDb
    10901
    ** of database handle db and make all valid snapshots available to
    10902
    ** sqlite3_snapshot_open(). It is an error if there is already a read
    10903
    ** transaction open on the database, or if the database is not a WAL mode
    10904
    ** database.
    10905
    **
    10906
    ** SQLITE_OK is returned if successful, or an SQLite error code otherwise.
    10907
    **
    10908
    ** This interface is only available if SQLite is compiled with the
    10909
    ** [SQLITE_ENABLE_SNAPSHOT] option.
    10910
    */
    10911
    SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb);
    10912
    10913
    /*
    10914
    ** CAPI3REF: Serialize a database
    10915
    **
    10916
    ** The sqlite3_serialize(D,S,P,F) interface returns a pointer to
    10917
    ** memory that is a serialization of the S database on
    10918
    ** [database connection] D.  If S is a NULL pointer, the main database is used.
    10919
    ** If P is not a NULL pointer, then the size of the database in bytes
    10920
    ** is written into *P.
    10921
    **
    10922
    ** For an ordinary on-disk database file, the serialization is just a
    10923
    ** copy of the disk file.  For an in-memory database or a "TEMP" database,
    10924
    ** the serialization is the same sequence of bytes which would be written
    10925
    ** to disk if that database were backed up to disk.
    10926
    **
    10927
    ** The usual case is that sqlite3_serialize() copies the serialization of
    10928
    ** the database into memory obtained from [sqlite3_malloc64()] and returns
    10929
    ** a pointer to that memory.  The caller is responsible for freeing the
    10930
    ** returned value to avoid a memory leak.  However, if the F argument
    10931
    ** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations
    10932
    ** are made, and the sqlite3_serialize() function will return a pointer
    10933
    ** to the contiguous memory representation of the database that SQLite
    10934
    ** is currently using for that database, or NULL if no such contiguous
    10935
    ** memory representation of the database exists.  A contiguous memory
    10936
    ** representation of the database will usually only exist if there has
    10937
    ** been a prior call to [sqlite3_deserialize(D,S,...)] with the same
    10938
    ** values of D and S.
    10939
    ** The size of the database is written into *P even if the
    10940
    ** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy
    10941
    ** of the database exists.
    10942
    **
    10943
    ** After the call, if the SQLITE_SERIALIZE_NOCOPY bit had been set,
    10944
    ** the returned buffer content will remain accessible and unchanged
    10945
    ** until either the next write operation on the connection or when
    10946
    ** the connection is closed, and applications must not modify the
    10947
    ** buffer. If the bit had been clear, the returned buffer will not
    10948
    ** be accessed by SQLite after the call.
    10949
    **
    10950
    ** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the
    10951
    ** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory
    10952
    ** allocation error occurs.
    10953
    **
    10954
    ** This interface is omitted if SQLite is compiled with the
    10955
    ** [SQLITE_OMIT_DESERIALIZE] option.
    10956
    */
    10957
    SQLITE_API unsigned char *sqlite3_serialize(
    10958
      sqlite3 *db,           /* The database connection */
    10959
      const char *zSchema,   /* Which DB to serialize. ex: "main", "temp", ... */
    10960
      sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */
    10961
      unsigned int mFlags    /* Zero or more SQLITE_SERIALIZE_* flags */
    10962
    );
    10963
    10964
    /*
    10965
    ** CAPI3REF: Flags for sqlite3_serialize
    10966
    **
    10967
    ** Zero or more of the following constants can be OR-ed together for
    10968
    ** the F argument to [sqlite3_serialize(D,S,P,F)].
    10969
    **
    10970
    ** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return
    10971
    ** a pointer to contiguous in-memory database that it is currently using,
    10972
    ** without making a copy of the database.  If SQLite is not currently using
    10973
    ** a contiguous in-memory database, then this option causes
    10974
    ** [sqlite3_serialize()] to return a NULL pointer.  SQLite will only be
    10975
    ** using a contiguous in-memory database if it has been initialized by a
    10976
    ** prior call to [sqlite3_deserialize()].
    10977
    */
    10978
    #define SQLITE_SERIALIZE_NOCOPY 0x001   /* Do no memory allocations */
    10979
    10980
    /*
    10981
    ** CAPI3REF: Deserialize a database
    10982
    **
    10983
    ** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the
    10984
    ** [database connection] D to disconnect from database S and then
    10985
    ** reopen S as an in-memory database based on the serialization contained
    10986
    ** in P.  The serialized database P is N bytes in size.  M is the size of
    10987
    ** the buffer P, which might be larger than N.  If M is larger than N, and
    10988
    ** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is
    10989
    ** permitted to add content to the in-memory database as long as the total
    10990
    ** size does not exceed M bytes.
    10991
    **
    10992
    ** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will
    10993
    ** invoke sqlite3_free() on the serialization buffer when the database
    10994
    ** connection closes.  If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then
    10995
    ** SQLite will try to increase the buffer size using sqlite3_realloc64()
    10996
    ** if writes on the database cause it to grow larger than M bytes.
    10997
    **
    10998
    ** Applications must not modify the buffer P or invalidate it before
    10999
    ** the database connection D is closed.
    11000
    **
    11001
    ** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the
    11002
    ** database is currently in a read transaction or is involved in a backup
    11003
    ** operation.
    11004
    **
    11005
    ** It is not possible to deserialize into the TEMP database.  If the
    11006
    ** S argument to sqlite3_deserialize(D,S,P,N,M,F) is "temp" then the
    11007
    ** function returns SQLITE_ERROR.
    11008
    **
    11009
    ** The deserialized database should not be in [WAL mode].  If the database
    11010
    ** is in WAL mode, then any attempt to use the database file will result
    11011
    ** in an [SQLITE_CANTOPEN] error.  The application can set the
    11012
    ** [file format version numbers] (bytes 18 and 19) of the input database P
    11013
    ** to 0x01 prior to invoking sqlite3_deserialize(D,S,P,N,M,F) to force the
    11014
    ** database file into rollback mode and work around this limitation.
    11015
    **
    11016
    ** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the
    11017
    ** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then
    11018
    ** [sqlite3_free()] is invoked on argument P prior to returning.
    11019
    **
    11020
    ** This interface is omitted if SQLite is compiled with the
    11021
    ** [SQLITE_OMIT_DESERIALIZE] option.
    11022
    */
    11023
    SQLITE_API int sqlite3_deserialize(
    11024
      sqlite3 *db,            /* The database connection */
    11025
      const char *zSchema,    /* Which DB to reopen with the deserialization */
    11026
      unsigned char *pData,   /* The serialized database content */
    11027
      sqlite3_int64 szDb,     /* Number of bytes in the deserialization */
    11028
      sqlite3_int64 szBuf,    /* Total size of buffer pData[] */
    11029
      unsigned mFlags         /* Zero or more SQLITE_DESERIALIZE_* flags */
    11030
    );
    11031
    11032
    /*
    11033
    ** CAPI3REF: Flags for sqlite3_deserialize()
    11034
    **
    11035
    ** The following are allowed values for the 6th argument (the F argument) to
    11036
    ** the [sqlite3_deserialize(D,S,P,N,M,F)] interface.
    11037
    **
    11038
    ** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization
    11039
    ** in the P argument is held in memory obtained from [sqlite3_malloc64()]
    11040
    ** and that SQLite should take ownership of this memory and automatically
    11041
    ** free it when it has finished using it.  Without this flag, the caller
    11042
    ** is responsible for freeing any dynamically allocated memory.
    11043
    **
    11044
    ** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to
    11045
    ** grow the size of the database using calls to [sqlite3_realloc64()].  This
    11046
    ** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used.
    11047
    ** Without this flag, the deserialized database cannot increase in size beyond
    11048
    ** the number of bytes specified by the M parameter.
    11049
    **
    11050
    ** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database
    11051
    ** should be treated as read-only.
    11052
    */
    11053
    #define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */
    11054
    #define SQLITE_DESERIALIZE_RESIZEABLE  2 /* Resize using sqlite3_realloc64() */
    11055
    #define SQLITE_DESERIALIZE_READONLY    4 /* Database is read-only */
    11056
    11057
    /*
    11058
    ** Undo the hack that converts floating point types to integer for
    11059
    ** builds on processors without floating point support.
    11060
    */
    11061
    #ifdef SQLITE_OMIT_FLOATING_POINT
    11062
    # undef double
    11063
    #endif
    11064
    11065
    #if defined(__wasi__)
    11066
    # undef SQLITE_WASI
    11067
    # define SQLITE_WASI 1
    11068
    # ifndef SQLITE_OMIT_LOAD_EXTENSION
    11069
    #  define SQLITE_OMIT_LOAD_EXTENSION
    11070
    # endif
    11071
    # ifndef SQLITE_THREADSAFE
    11072
    #  define SQLITE_THREADSAFE 0
    11073
    # endif
    11074
    #endif
    11075
    11076
    #ifdef __cplusplus
    11077
    }  /* End of the 'extern "C"' block */
    11078
    #endif
    11079
    /* #endif for SQLITE3_H will be added by mksqlite3.tcl */
    11080
    11081
    /******** Begin file sqlite3rtree.h *********/
    11082
    /*
    11083
    ** 2010 August 30
    11084
    **
    11085
    ** The author disclaims copyright to this source code.  In place of
    11086
    ** a legal notice, here is a blessing:
    11087
    **
    11088
    **    May you do good and not evil.
    11089
    **    May you find forgiveness for yourself and forgive others.
    11090
    **    May you share freely, never taking more than you give.
    11091
    **
    11092
    *************************************************************************
    11093
    */
    11094
    11095
    #ifndef _SQLITE3RTREE_H_
    11096
    #define _SQLITE3RTREE_H_
    11097
    11098
    11099
    #ifdef __cplusplus
    11100
    extern "C" {
    11101
    #endif
    11102
    11103
    typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;
    11104
    typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info;
    11105
    11106
    /* The double-precision datatype used by RTree depends on the
    11107
    ** SQLITE_RTREE_INT_ONLY compile-time option.
    11108
    */
    11109
    #ifdef SQLITE_RTREE_INT_ONLY
    11110
      typedef sqlite3_int64 sqlite3_rtree_dbl;
    11111
    #else
    11112
      typedef double sqlite3_rtree_dbl;
    11113
    #endif
    11114
    11115
    /*
    11116
    ** Register a geometry callback named zGeom that can be used as part of an
    11117
    ** R-Tree geometry query as follows:
    11118
    **
    11119
    **   SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...)
    11120
    */
    11121
    SQLITE_API int sqlite3_rtree_geometry_callback(
    11122
      sqlite3 *db,
    11123
      const char *zGeom,
    11124
      int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*),
    11125
      void *pContext
    11126
    );
    11127
    11128
    11129
    /*
    11130
    ** A pointer to a structure of the following type is passed as the first
    11131
    ** argument to callbacks registered using rtree_geometry_callback().
    11132
    */
    11133
    struct sqlite3_rtree_geometry {
    11134
      void *pContext;                 /* Copy of pContext passed to s_r_g_c() */
    11135
      int nParam;                     /* Size of array aParam[] */
    11136
      sqlite3_rtree_dbl *aParam;      /* Parameters passed to SQL geom function */
    11137
      void *pUser;                    /* Callback implementation user data */
    11138
      void (*xDelUser)(void *);       /* Called by SQLite to clean up pUser */
    11139
    };
    11140
    11141
    /*
    11142
    ** Register a 2nd-generation geometry callback named zScore that can be
    11143
    ** used as part of an R-Tree geometry query as follows:
    11144
    **
    11145
    **   SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...)
    11146
    */
    11147
    SQLITE_API int sqlite3_rtree_query_callback(
    11148
      sqlite3 *db,
    11149
      const char *zQueryFunc,
    11150
      int (*xQueryFunc)(sqlite3_rtree_query_info*),
    11151
      void *pContext,
    11152
      void (*xDestructor)(void*)
    11153
    );
    11154
    11155
    11156
    /*
    11157
    ** A pointer to a structure of the following type is passed as the
    11158
    ** argument to scored geometry callback registered using
    11159
    ** sqlite3_rtree_query_callback().
    11160
    **
    11161
    ** Note that the first 5 fields of this structure are identical to
    11162
    ** sqlite3_rtree_geometry.  This structure is a subclass of
    11163
    ** sqlite3_rtree_geometry.
    11164
    */
    11165
    struct sqlite3_rtree_query_info {
    11166
      void *pContext;                   /* pContext from when function registered */
    11167
      int nParam;                       /* Number of function parameters */
    11168
      sqlite3_rtree_dbl *aParam;        /* value of function parameters */
    11169
      void *pUser;                      /* callback can use this, if desired */
    11170
      void (*xDelUser)(void*);          /* function to free pUser */
    11171
      sqlite3_rtree_dbl *aCoord;        /* Coordinates of node or entry to check */
    11172
      unsigned int *anQueue;            /* Number of pending entries in the queue */
    11173
      int nCoord;                       /* Number of coordinates */
    11174
      int iLevel;                       /* Level of current node or entry */
    11175
      int mxLevel;                      /* The largest iLevel value in the tree */
    11176
      sqlite3_int64 iRowid;             /* Rowid for current entry */
    11177
      sqlite3_rtree_dbl rParentScore;   /* Score of parent node */
    11178
      int eParentWithin;                /* Visibility of parent node */
    11179
      int eWithin;                      /* OUT: Visibility */
    11180
      sqlite3_rtree_dbl rScore;         /* OUT: Write the score here */
    11181
      /* The following fields are only available in 3.8.11 and later */
    11182
      sqlite3_value **apSqlParam;       /* Original SQL values of parameters */
    11183
    };
    11184
    11185
    /*
    11186
    ** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin.
    11187
    */
    11188
    #define NOT_WITHIN       0   /* Object completely outside of query region */
    11189
    #define PARTLY_WITHIN    1   /* Object partially overlaps query region */
    11190
    #define FULLY_WITHIN     2   /* Object fully contained within query region */
    11191
    11192
    11193
    #ifdef __cplusplus
    11194
    }  /* end of the 'extern "C"' block */
    11195
    #endif
    11196
    11197
    #endif  /* ifndef _SQLITE3RTREE_H_ */
    11198
    11199
    /******** End of sqlite3rtree.h *********/
    11200
    /******** Begin file sqlite3session.h *********/
    11201
    11202
    #if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION)
    11203
    #define __SQLITESESSION_H_ 1
    11204
    11205
    /*
    11206
    ** Make sure we can call this stuff from C++.
    11207
    */
    11208
    #ifdef __cplusplus
    11209
    extern "C" {
    11210
    #endif
    11211
    11212
    11213
    /*
    11214
    ** CAPI3REF: Session Object Handle
    11215
    **
    11216
    ** An instance of this object is a [session] that can be used to
    11217
    ** record changes to a database.
    11218
    */
    11219
    typedef struct sqlite3_session sqlite3_session;
    11220
    11221
    /*
    11222
    ** CAPI3REF: Changeset Iterator Handle
    11223
    **
    11224
    ** An instance of this object acts as a cursor for iterating
    11225
    ** over the elements of a [changeset] or [patchset].
    11226
    */
    11227
    typedef struct sqlite3_changeset_iter sqlite3_changeset_iter;
    11228
    11229
    /*
    11230
    ** CAPI3REF: Create A New Session Object
    11231
    ** CONSTRUCTOR: sqlite3_session
    11232
    **
    11233
    ** Create a new session object attached to database handle db. If successful,
    11234
    ** a pointer to the new object is written to *ppSession and SQLITE_OK is
    11235
    ** returned. If an error occurs, *ppSession is set to NULL and an SQLite
    11236
    ** error code (e.g. SQLITE_NOMEM) is returned.
    11237
    **
    11238
    ** It is possible to create multiple session objects attached to a single
    11239
    ** database handle.
    11240
    **
    11241
    ** Session objects created using this function should be deleted using the
    11242
    ** [sqlite3session_delete()] function before the database handle that they
    11243
    ** are attached to is itself closed. If the database handle is closed before
    11244
    ** the session object is deleted, then the results of calling any session
    11245
    ** module function, including [sqlite3session_delete()] on the session object
    11246
    ** are undefined.
    11247
    **
    11248
    ** Because the session module uses the [sqlite3_preupdate_hook()] API, it
    11249
    ** is not possible for an application to register a pre-update hook on a
    11250
    ** database handle that has one or more session objects attached. Nor is
    11251
    ** it possible to create a session object attached to a database handle for
    11252
    ** which a pre-update hook is already defined. The results of attempting
    11253
    ** either of these things are undefined.
    11254
    **
    11255
    ** The session object will be used to create changesets for tables in
    11256
    ** database zDb, where zDb is either "main", or "temp", or the name of an
    11257
    ** attached database. It is not an error if database zDb is not attached
    11258
    ** to the database when the session object is created.
    11259
    */
    11260
    SQLITE_API int sqlite3session_create(
    11261
      sqlite3 *db,                    /* Database handle */
    11262
      const char *zDb,                /* Name of db (e.g. "main") */
    11263
      sqlite3_session **ppSession     /* OUT: New session object */
    11264
    );
    11265
    11266
    /*
    11267
    ** CAPI3REF: Delete A Session Object
    11268
    ** DESTRUCTOR: sqlite3_session
    11269
    **
    11270
    ** Delete a session object previously allocated using
    11271
    ** [sqlite3session_create()]. Once a session object has been deleted, the
    11272
    ** results of attempting to use pSession with any other session module
    11273
    ** function are undefined.
    11274
    **
    11275
    ** Session objects must be deleted before the database handle to which they
    11276
    ** are attached is closed. Refer to the documentation for
    11277
    ** [sqlite3session_create()] for details.
    11278
    */
    11279
    SQLITE_API void sqlite3session_delete(sqlite3_session *pSession);
    11280
    11281
    /*
    11282
    ** CAPI3REF: Configure a Session Object
    11283
    ** METHOD: sqlite3_session
    11284
    **
    11285
    ** This method is used to configure a session object after it has been
    11286
    ** created. At present the only valid values for the second parameter are
    11287
    ** [SQLITE_SESSION_OBJCONFIG_SIZE] and [SQLITE_SESSION_OBJCONFIG_ROWID].
    11288
    **
    11289
    */
    11290
    SQLITE_API int sqlite3session_object_config(sqlite3_session*, int op, void *pArg);
    11291
    11292
    /*
    11293
    ** CAPI3REF: Options for sqlite3session_object_config
    11294
    **
    11295
    ** The following values may passed as the the 2nd parameter to
    11296
    ** sqlite3session_object_config().
    11297
    **
    11298
    ** <dt>SQLITE_SESSION_OBJCONFIG_SIZE <dd>
    11299
    **   This option is used to set, clear or query the flag that enables
    11300
    **   the [sqlite3session_changeset_size()] API. Because it imposes some
    11301
    **   computational overhead, this API is disabled by default. Argument
    11302
    **   pArg must point to a value of type (int). If the value is initially
    11303
    **   0, then the sqlite3session_changeset_size() API is disabled. If it
    11304
    **   is greater than 0, then the same API is enabled. Or, if the initial
    11305
    **   value is less than zero, no change is made. In all cases the (int)
    11306
    **   variable is set to 1 if the sqlite3session_changeset_size() API is
    11307
    **   enabled following the current call, or 0 otherwise.
    11308
    **
    11309
    **   It is an error (SQLITE_MISUSE) to attempt to modify this setting after
    11310
    **   the first table has been attached to the session object.
    11311
    **
    11312
    ** <dt>SQLITE_SESSION_OBJCONFIG_ROWID <dd>
    11313
    **   This option is used to set, clear or query the flag that enables
    11314
    **   collection of data for tables with no explicit PRIMARY KEY.
    11315
    **
    11316
    **   Normally, tables with no explicit PRIMARY KEY are simply ignored
    11317
    **   by the sessions module. However, if this flag is set, it behaves
    11318
    **   as if such tables have a column "_rowid_ INTEGER PRIMARY KEY" inserted
    11319
    **   as their leftmost columns.
    11320
    **
    11321
    **   It is an error (SQLITE_MISUSE) to attempt to modify this setting after
    11322
    **   the first table has been attached to the session object.
    11323
    */
    11324
    #define SQLITE_SESSION_OBJCONFIG_SIZE  1
    11325
    #define SQLITE_SESSION_OBJCONFIG_ROWID 2
    11326
    11327
    /*
    11328
    ** CAPI3REF: Enable Or Disable A Session Object
    11329
    ** METHOD: sqlite3_session
    11330
    **
    11331
    ** Enable or disable the recording of changes by a session object. When
    11332
    ** enabled, a session object records changes made to the database. When
    11333
    ** disabled - it does not. A newly created session object is enabled.
    11334
    ** Refer to the documentation for [sqlite3session_changeset()] for further
    11335
    ** details regarding how enabling and disabling a session object affects
    11336
    ** the eventual changesets.
    11337
    **
    11338
    ** Passing zero to this function disables the session. Passing a value
    11339
    ** greater than zero enables it. Passing a value less than zero is a
    11340
    ** no-op, and may be used to query the current state of the session.
    11341
    **
    11342
    ** The return value indicates the final state of the session object: 0 if
    11343
    ** the session is disabled, or 1 if it is enabled.
    11344
    */
    11345
    SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable);
    11346
    11347
    /*
    11348
    ** CAPI3REF: Set Or Clear the Indirect Change Flag
    11349
    ** METHOD: sqlite3_session
    11350
    **
    11351
    ** Each change recorded by a session object is marked as either direct or
    11352
    ** indirect. A change is marked as indirect if either:
    11353
    **
    11354
    ** <ul>
    11355
    **   <li> The session object "indirect" flag is set when the change is
    11356
    **        made, or
    11357
    **   <li> The change is made by an SQL trigger or foreign key action
    11358
    **        instead of directly as a result of a users SQL statement.
    11359
    ** </ul>
    11360
    **
    11361
    ** If a single row is affected by more than one operation within a session,
    11362
    ** then the change is considered indirect if all operations meet the criteria
    11363
    ** for an indirect change above, or direct otherwise.
    11364
    **
    11365
    ** This function is used to set, clear or query the session object indirect
    11366
    ** flag.  If the second argument passed to this function is zero, then the
    11367
    ** indirect flag is cleared. If it is greater than zero, the indirect flag
    11368
    ** is set. Passing a value less than zero does not modify the current value
    11369
    ** of the indirect flag, and may be used to query the current state of the
    11370
    ** indirect flag for the specified session object.
    11371
    **
    11372
    ** The return value indicates the final state of the indirect flag: 0 if
    11373
    ** it is clear, or 1 if it is set.
    11374
    */
    11375
    SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect);
    11376
    11377
    /*
    11378
    ** CAPI3REF: Attach A Table To A Session Object
    11379
    ** METHOD: sqlite3_session
    11380
    **
    11381
    ** If argument zTab is not NULL, then it is the name of a table to attach
    11382
    ** to the session object passed as the first argument. All subsequent changes
    11383
    ** made to the table while the session object is enabled will be recorded. See
    11384
    ** documentation for [sqlite3session_changeset()] for further details.
    11385
    **
    11386
    ** Or, if argument zTab is NULL, then changes are recorded for all tables
    11387
    ** in the database. If additional tables are added to the database (by
    11388
    ** executing "CREATE TABLE" statements) after this call is made, changes for
    11389
    ** the new tables are also recorded.
    11390
    **
    11391
    ** Changes can only be recorded for tables that have a PRIMARY KEY explicitly
    11392
    ** defined as part of their CREATE TABLE statement. It does not matter if the
    11393
    ** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY
    11394
    ** KEY may consist of a single column, or may be a composite key.
    11395
    **
    11396
    ** It is not an error if the named table does not exist in the database. Nor
    11397
    ** is it an error if the named table does not have a PRIMARY KEY. However,
    11398
    ** no changes will be recorded in either of these scenarios.
    11399
    **
    11400
    ** Changes are not recorded for individual rows that have NULL values stored
    11401
    ** in one or more of their PRIMARY KEY columns.
    11402
    **
    11403
    ** SQLITE_OK is returned if the call completes without error. Or, if an error
    11404
    ** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned.
    11405
    **
    11406
    ** <h3>Special sqlite_stat1 Handling</h3>
    11407
    **
    11408
    ** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to
    11409
    ** some of the rules above. In SQLite, the schema of sqlite_stat1 is:
    11410
    **  <pre>
    11411
    **  &nbsp;     CREATE TABLE sqlite_stat1(tbl,idx,stat)
    11412
    **  </pre>
    11413
    **
    11414
    ** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are
    11415
    ** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes
    11416
    ** are recorded for rows for which (idx IS NULL) is true. However, for such
    11417
    ** rows a zero-length blob (SQL value X'') is stored in the changeset or
    11418
    ** patchset instead of a NULL value. This allows such changesets to be
    11419
    ** manipulated by legacy implementations of sqlite3changeset_invert(),
    11420
    ** concat() and similar.
    11421
    **
    11422
    ** The sqlite3changeset_apply() function automatically converts the
    11423
    ** zero-length blob back to a NULL value when updating the sqlite_stat1
    11424
    ** table. However, if the application calls sqlite3changeset_new(),
    11425
    ** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset
    11426
    ** iterator directly (including on a changeset iterator passed to a
    11427
    ** conflict-handler callback) then the X'' value is returned. The application
    11428
    ** must translate X'' to NULL itself if required.
    11429
    **
    11430
    ** Legacy (older than 3.22.0) versions of the sessions module cannot capture
    11431
    ** changes made to the sqlite_stat1 table. Legacy versions of the
    11432
    ** sqlite3changeset_apply() function silently ignore any modifications to the
    11433
    ** sqlite_stat1 table that are part of a changeset or patchset.
    11434
    */
    11435
    SQLITE_API int sqlite3session_attach(
    11436
      sqlite3_session *pSession,      /* Session object */
    11437
      const char *zTab                /* Table name */
    11438
    );
    11439
    11440
    /*
    11441
    ** CAPI3REF: Set a table filter on a Session Object.
    11442
    ** METHOD: sqlite3_session
    11443
    **
    11444
    ** The second argument (xFilter) is the "filter callback". For changes to rows
    11445
    ** in tables that are not attached to the Session object, the filter is called
    11446
    ** to determine whether changes to the table's rows should be tracked or not.
    11447
    ** If xFilter returns 0, changes are not tracked. Note that once a table is
    11448
    ** attached, xFilter will not be called again.
    11449
    */
    11450
    SQLITE_API void sqlite3session_table_filter(
    11451
      sqlite3_session *pSession,      /* Session object */
    11452
      int(*xFilter)(
    11453
        void *pCtx,                   /* Copy of third arg to _filter_table() */
    11454
        const char *zTab              /* Table name */
    11455
      ),
    11456
      void *pCtx                      /* First argument passed to xFilter */
    11457
    );
    11458
    11459
    /*
    11460
    ** CAPI3REF: Generate A Changeset From A Session Object
    11461
    ** METHOD: sqlite3_session
    11462
    **
    11463
    ** Obtain a changeset containing changes to the tables attached to the
    11464
    ** session object passed as the first argument. If successful,
    11465
    ** set *ppChangeset to point to a buffer containing the changeset
    11466
    ** and *pnChangeset to the size of the changeset in bytes before returning
    11467
    ** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to
    11468
    ** zero and return an SQLite error code.
    11469
    **
    11470
    ** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes,
    11471
    ** each representing a change to a single row of an attached table. An INSERT
    11472
    ** change contains the values of each field of a new database row. A DELETE
    11473
    ** contains the original values of each field of a deleted database row. An
    11474
    ** UPDATE change contains the original values of each field of an updated
    11475
    ** database row along with the updated values for each updated non-primary-key
    11476
    ** column. It is not possible for an UPDATE change to represent a change that
    11477
    ** modifies the values of primary key columns. If such a change is made, it
    11478
    ** is represented in a changeset as a DELETE followed by an INSERT.
    11479
    **
    11480
    ** Changes are not recorded for rows that have NULL values stored in one or
    11481
    ** more of their PRIMARY KEY columns. If such a row is inserted or deleted,
    11482
    ** no corresponding change is present in the changesets returned by this
    11483
    ** function. If an existing row with one or more NULL values stored in
    11484
    ** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL,
    11485
    ** only an INSERT is appears in the changeset. Similarly, if an existing row
    11486
    ** with non-NULL PRIMARY KEY values is updated so that one or more of its
    11487
    ** PRIMARY KEY columns are set to NULL, the resulting changeset contains a
    11488
    ** DELETE change only.
    11489
    **
    11490
    ** The contents of a changeset may be traversed using an iterator created
    11491
    ** using the [sqlite3changeset_start()] API. A changeset may be applied to
    11492
    ** a database with a compatible schema using the [sqlite3changeset_apply()]
    11493
    ** API.
    11494
    **
    11495
    ** Within a changeset generated by this function, all changes related to a
    11496
    ** single table are grouped together. In other words, when iterating through
    11497
    ** a changeset or when applying a changeset to a database, all changes related
    11498
    ** to a single table are processed before moving on to the next table. Tables
    11499
    ** are sorted in the same order in which they were attached (or auto-attached)
    11500
    ** to the sqlite3_session object. The order in which the changes related to
    11501
    ** a single table are stored is undefined.
    11502
    **
    11503
    ** Following a successful call to this function, it is the responsibility of
    11504
    ** the caller to eventually free the buffer that *ppChangeset points to using
    11505
    ** [sqlite3_free()].
    11506
    **
    11507
    ** <h3>Changeset Generation</h3>
    11508
    **
    11509
    ** Once a table has been attached to a session object, the session object
    11510
    ** records the primary key values of all new rows inserted into the table.
    11511
    ** It also records the original primary key and other column values of any
    11512
    ** deleted or updated rows. For each unique primary key value, data is only
    11513
    ** recorded once - the first time a row with said primary key is inserted,
    11514
    ** updated or deleted in the lifetime of the session.
    11515
    **
    11516
    ** There is one exception to the previous paragraph: when a row is inserted,
    11517
    ** updated or deleted, if one or more of its primary key columns contain a
    11518
    ** NULL value, no record of the change is made.
    11519
    **
    11520
    ** The session object therefore accumulates two types of records - those
    11521
    ** that consist of primary key values only (created when the user inserts
    11522
    ** a new record) and those that consist of the primary key values and the
    11523
    ** original values of other table columns (created when the users deletes
    11524
    ** or updates a record).
    11525
    **
    11526
    ** When this function is called, the requested changeset is created using
    11527
    ** both the accumulated records and the current contents of the database
    11528
    ** file. Specifically:
    11529
    **
    11530
    ** <ul>
    11531
    **   <li> For each record generated by an insert, the database is queried
    11532
    **        for a row with a matching primary key. If one is found, an INSERT
    11533
    **        change is added to the changeset. If no such row is found, no change
    11534
    **        is added to the changeset.
    11535
    **
    11536
    **   <li> For each record generated by an update or delete, the database is
    11537
    **        queried for a row with a matching primary key. If such a row is
    11538
    **        found and one or more of the non-primary key fields have been
    11539
    **        modified from their original values, an UPDATE change is added to
    11540
    **        the changeset. Or, if no such row is found in the table, a DELETE
    11541
    **        change is added to the changeset. If there is a row with a matching
    11542
    **        primary key in the database, but all fields contain their original
    11543
    **        values, no change is added to the changeset.
    11544
    ** </ul>
    11545
    **
    11546
    ** This means, amongst other things, that if a row is inserted and then later
    11547
    ** deleted while a session object is active, neither the insert nor the delete
    11548
    ** will be present in the changeset. Or if a row is deleted and then later a
    11549
    ** row with the same primary key values inserted while a session object is
    11550
    ** active, the resulting changeset will contain an UPDATE change instead of
    11551
    ** a DELETE and an INSERT.
    11552
    **
    11553
    ** When a session object is disabled (see the [sqlite3session_enable()] API),
    11554
    ** it does not accumulate records when rows are inserted, updated or deleted.
    11555
    ** This may appear to have some counter-intuitive effects if a single row
    11556
    ** is written to more than once during a session. For example, if a row
    11557
    ** is inserted while a session object is enabled, then later deleted while
    11558
    ** the same session object is disabled, no INSERT record will appear in the
    11559
    ** changeset, even though the delete took place while the session was disabled.
    11560
    ** Or, if one field of a row is updated while a session is enabled, and
    11561
    ** then another field of the same row is updated while the session is disabled,
    11562
    ** the resulting changeset will contain an UPDATE change that updates both
    11563
    ** fields.
    11564
    */
    11565
    SQLITE_API int sqlite3session_changeset(
    11566
      sqlite3_session *pSession,      /* Session object */
    11567
      int *pnChangeset,               /* OUT: Size of buffer at *ppChangeset */
    11568
      void **ppChangeset              /* OUT: Buffer containing changeset */
    11569
    );
    11570
    11571
    /*
    11572
    ** CAPI3REF: Return An Upper-limit For The Size Of The Changeset
    11573
    ** METHOD: sqlite3_session
    11574
    **
    11575
    ** By default, this function always returns 0. For it to return
    11576
    ** a useful result, the sqlite3_session object must have been configured
    11577
    ** to enable this API using sqlite3session_object_config() with the
    11578
    ** SQLITE_SESSION_OBJCONFIG_SIZE verb.
    11579
    **
    11580
    ** When enabled, this function returns an upper limit, in bytes, for the size
    11581
    ** of the changeset that might be produced if sqlite3session_changeset() were
    11582
    ** called. The final changeset size might be equal to or smaller than the
    11583
    ** size in bytes returned by this function.
    11584
    */
    11585
    SQLITE_API sqlite3_int64 sqlite3session_changeset_size(sqlite3_session *pSession);
    11586
    11587
    /*
    11588
    ** CAPI3REF: Load The Difference Between Tables Into A Session
    11589
    ** METHOD: sqlite3_session
    11590
    **
    11591
    ** If it is not already attached to the session object passed as the first
    11592
    ** argument, this function attaches table zTbl in the same manner as the
    11593
    ** [sqlite3session_attach()] function. If zTbl does not exist, or if it
    11594
    ** does not have a primary key, this function is a no-op (but does not return
    11595
    ** an error).
    11596
    **
    11597
    ** Argument zFromDb must be the name of a database ("main", "temp" etc.)
    11598
    ** attached to the same database handle as the session object that contains
    11599
    ** a table compatible with the table attached to the session by this function.
    11600
    ** A table is considered compatible if it:
    11601
    **
    11602
    ** <ul>
    11603
    **   <li> Has the same name,
    11604
    **   <li> Has the same set of columns declared in the same order, and
    11605
    **   <li> Has the same PRIMARY KEY definition.
    11606
    ** </ul>
    11607
    **
    11608
    ** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables
    11609
    ** are compatible but do not have any PRIMARY KEY columns, it is not an error
    11610
    ** but no changes are added to the session object. As with other session
    11611
    ** APIs, tables without PRIMARY KEYs are simply ignored.
    11612
    **
    11613
    ** This function adds a set of changes to the session object that could be
    11614
    ** used to update the table in database zFrom (call this the "from-table")
    11615
    ** so that its content is the same as the table attached to the session
    11616
    ** object (call this the "to-table"). Specifically:
    11617
    **
    11618
    ** <ul>
    11619
    **   <li> For each row (primary key) that exists in the to-table but not in
    11620
    **     the from-table, an INSERT record is added to the session object.
    11621
    **
    11622
    **   <li> For each row (primary key) that exists in the to-table but not in
    11623
    **     the from-table, a DELETE record is added to the session object.
    11624
    **
    11625
    **   <li> For each row (primary key) that exists in both tables, but features
    11626
    **     different non-PK values in each, an UPDATE record is added to the
    11627
    **     session.
    11628
    ** </ul>
    11629
    **
    11630
    ** To clarify, if this function is called and then a changeset constructed
    11631
    ** using [sqlite3session_changeset()], then after applying that changeset to
    11632
    ** database zFrom the contents of the two compatible tables would be
    11633
    ** identical.
    11634
    **
    11635
    ** Unless the call to this function is a no-op as described above, it is an
    11636
    ** error if database zFrom does not exist or does not contain the required
    11637
    ** compatible table.
    11638
    **
    11639
    ** If the operation is successful, SQLITE_OK is returned. Otherwise, an SQLite
    11640
    ** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg
    11641
    ** may be set to point to a buffer containing an English language error
    11642
    ** message. It is the responsibility of the caller to free this buffer using
    11643
    ** sqlite3_free().
    11644
    */
    11645
    SQLITE_API int sqlite3session_diff(
    11646
      sqlite3_session *pSession,
    11647
      const char *zFromDb,
    11648
      const char *zTbl,
    11649
      char **pzErrMsg
    11650
    );
    11651
    11652
    11653
    /*
    11654
    ** CAPI3REF: Generate A Patchset From A Session Object
    11655
    ** METHOD: sqlite3_session
    11656
    **
    11657
    ** The differences between a patchset and a changeset are that:
    11658
    **
    11659
    ** <ul>
    11660
    **   <li> DELETE records consist of the primary key fields only. The
    11661
    **        original values of other fields are omitted.
    11662
    **   <li> The original values of any modified fields are omitted from
    11663
    **        UPDATE records.
    11664
    ** </ul>
    11665
    **
    11666
    ** A patchset blob may be used with up to date versions of all
    11667
    ** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(),
    11668
    ** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly,
    11669
    ** attempting to use a patchset blob with old versions of the
    11670
    ** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error.
    11671
    **
    11672
    ** Because the non-primary key "old.*" fields are omitted, no
    11673
    ** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset
    11674
    ** is passed to the sqlite3changeset_apply() API. Other conflict types work
    11675
    ** in the same way as for changesets.
    11676
    **
    11677
    ** Changes within a patchset are ordered in the same way as for changesets
    11678
    ** generated by the sqlite3session_changeset() function (i.e. all changes for
    11679
    ** a single table are grouped together, tables appear in the order in which
    11680
    ** they were attached to the session object).
    11681
    */
    11682
    SQLITE_API int sqlite3session_patchset(
    11683
      sqlite3_session *pSession,      /* Session object */
    11684
      int *pnPatchset,                /* OUT: Size of buffer at *ppPatchset */
    11685
      void **ppPatchset               /* OUT: Buffer containing patchset */
    11686
    );
    11687
    11688
    /*
    11689
    ** CAPI3REF: Test if a changeset has recorded any changes.
    11690
    **
    11691
    ** Return non-zero if no changes to attached tables have been recorded by
    11692
    ** the session object passed as the first argument. Otherwise, if one or
    11693
    ** more changes have been recorded, return zero.
    11694
    **
    11695
    ** Even if this function returns zero, it is possible that calling
    11696
    ** [sqlite3session_changeset()] on the session handle may still return a
    11697
    ** changeset that contains no changes. This can happen when a row in
    11698
    ** an attached table is modified and then later on the original values
    11699
    ** are restored. However, if this function returns non-zero, then it is
    11700
    ** guaranteed that a call to sqlite3session_changeset() will return a
    11701
    ** changeset containing zero changes.
    11702
    */
    11703
    SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession);
    11704
    11705
    /*
    11706
    ** CAPI3REF: Query for the amount of heap memory used by a session object.
    11707
    **
    11708
    ** This API returns the total amount of heap memory in bytes currently
    11709
    ** used by the session object passed as the only argument.
    11710
    */
    11711
    SQLITE_API sqlite3_int64 sqlite3session_memory_used(sqlite3_session *pSession);
    11712
    11713
    /*
    11714
    ** CAPI3REF: Create An Iterator To Traverse A Changeset
    11715
    ** CONSTRUCTOR: sqlite3_changeset_iter
    11716
    **
    11717
    ** Create an iterator used to iterate through the contents of a changeset.
    11718
    ** If successful, *pp is set to point to the iterator handle and SQLITE_OK
    11719
    ** is returned. Otherwise, if an error occurs, *pp is set to zero and an
    11720
    ** SQLite error code is returned.
    11721
    **
    11722
    ** The following functions can be used to advance and query a changeset
    11723
    ** iterator created by this function:
    11724
    **
    11725
    ** <ul>
    11726
    **   <li> [sqlite3changeset_next()]
    11727
    **   <li> [sqlite3changeset_op()]
    11728
    **   <li> [sqlite3changeset_new()]
    11729
    **   <li> [sqlite3changeset_old()]
    11730
    ** </ul>
    11731
    **
    11732
    ** It is the responsibility of the caller to eventually destroy the iterator
    11733
    ** by passing it to [sqlite3changeset_finalize()]. The buffer containing the
    11734
    ** changeset (pChangeset) must remain valid until after the iterator is
    11735
    ** destroyed.
    11736
    **
    11737
    ** Assuming the changeset blob was created by one of the
    11738
    ** [sqlite3session_changeset()], [sqlite3changeset_concat()] or
    11739
    ** [sqlite3changeset_invert()] functions, all changes within the changeset
    11740
    ** that apply to a single table are grouped together. This means that when
    11741
    ** an application iterates through a changeset using an iterator created by
    11742
    ** this function, all changes that relate to a single table are visited
    11743
    ** consecutively. There is no chance that the iterator will visit a change
    11744
    ** the applies to table X, then one for table Y, and then later on visit
    11745
    ** another change for table X.
    11746
    **
    11747
    ** The behavior of sqlite3changeset_start_v2() and its streaming equivalent
    11748
    ** may be modified by passing a combination of
    11749
    ** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter.
    11750
    **
    11751
    ** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b>
    11752
    ** and therefore subject to change.
    11753
    */
    11754
    SQLITE_API int sqlite3changeset_start(
    11755
      sqlite3_changeset_iter **pp,    /* OUT: New changeset iterator handle */
    11756
      int nChangeset,                 /* Size of changeset blob in bytes */
    11757
      void *pChangeset                /* Pointer to blob containing changeset */
    11758
    );
    11759
    SQLITE_API int sqlite3changeset_start_v2(
    11760
      sqlite3_changeset_iter **pp,    /* OUT: New changeset iterator handle */
    11761
      int nChangeset,                 /* Size of changeset blob in bytes */
    11762
      void *pChangeset,               /* Pointer to blob containing changeset */
    11763
      int flags                       /* SESSION_CHANGESETSTART_* flags */
    11764
    );
    11765
    11766
    /*
    11767
    ** CAPI3REF: Flags for sqlite3changeset_start_v2
    11768
    **
    11769
    ** The following flags may passed via the 4th parameter to
    11770
    ** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]:
    11771
    **
    11772
    ** <dt>SQLITE_CHANGESETSTART_INVERT <dd>
    11773
    **   Invert the changeset while iterating through it. This is equivalent to
    11774
    **   inverting a changeset using sqlite3changeset_invert() before applying it.
    11775
    **   It is an error to specify this flag with a patchset.
    11776
    */
    11777
    #define SQLITE_CHANGESETSTART_INVERT        0x0002
    11778
    11779
    11780
    /*
    11781
    ** CAPI3REF: Advance A Changeset Iterator
    11782
    ** METHOD: sqlite3_changeset_iter
    11783
    **
    11784
    ** This function may only be used with iterators created by the function
    11785
    ** [sqlite3changeset_start()]. If it is called on an iterator passed to
    11786
    ** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE
    11787
    ** is returned and the call has no effect.
    11788
    **
    11789
    ** Immediately after an iterator is created by sqlite3changeset_start(), it
    11790
    ** does not point to any change in the changeset. Assuming the changeset
    11791
    ** is not empty, the first call to this function advances the iterator to
    11792
    ** point to the first change in the changeset. Each subsequent call advances
    11793
    ** the iterator to point to the next change in the changeset (if any). If
    11794
    ** no error occurs and the iterator points to a valid change after a call
    11795
    ** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned.
    11796
    ** Otherwise, if all changes in the changeset have already been visited,
    11797
    ** SQLITE_DONE is returned.
    11798
    **
    11799
    ** If an error occurs, an SQLite error code is returned. Possible error
    11800
    ** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or
    11801
    ** SQLITE_NOMEM.
    11802
    */
    11803
    SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter);
    11804
    11805
    /*
    11806
    ** CAPI3REF: Obtain The Current Operation From A Changeset Iterator
    11807
    ** METHOD: sqlite3_changeset_iter
    11808
    **
    11809
    ** The pIter argument passed to this function may either be an iterator
    11810
    ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
    11811
    ** created by [sqlite3changeset_start()]. In the latter case, the most recent
    11812
    ** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this
    11813
    ** is not the case, this function returns [SQLITE_MISUSE].
    11814
    **
    11815
    ** Arguments pOp, pnCol and pzTab may not be NULL. Upon return, three
    11816
    ** outputs are set through these pointers:
    11817
    **
    11818
    ** *pOp is set to one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE],
    11819
    ** depending on the type of change that the iterator currently points to;
    11820
    **
    11821
    ** *pnCol is set to the number of columns in the table affected by the change; and
    11822
    **
    11823
    ** *pzTab is set to point to a nul-terminated utf-8 encoded string containing
    11824
    ** the name of the table affected by the current change. The buffer remains
    11825
    ** valid until either sqlite3changeset_next() is called on the iterator
    11826
    ** or until the conflict-handler function returns.
    11827
    **
    11828
    ** If pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change
    11829
    ** is an indirect change, or false (0) otherwise. See the documentation for
    11830
    ** [sqlite3session_indirect()] for a description of direct and indirect
    11831
    ** changes.
    11832
    **
    11833
    ** If no error occurs, SQLITE_OK is returned. If an error does occur, an
    11834
    ** SQLite error code is returned. The values of the output variables may not
    11835
    ** be trusted in this case.
    11836
    */
    11837
    SQLITE_API int sqlite3changeset_op(
    11838
      sqlite3_changeset_iter *pIter,  /* Iterator object */
    11839
      const char **pzTab,             /* OUT: Pointer to table name */
    11840
      int *pnCol,                     /* OUT: Number of columns in table */
    11841
      int *pOp,                       /* OUT: SQLITE_INSERT, DELETE or UPDATE */
    11842
      int *pbIndirect                 /* OUT: True for an 'indirect' change */
    11843
    );
    11844
    11845
    /*
    11846
    ** CAPI3REF: Obtain The Primary Key Definition Of A Table
    11847
    ** METHOD: sqlite3_changeset_iter
    11848
    **
    11849
    ** For each modified table, a changeset includes the following:
    11850
    **
    11851
    ** <ul>
    11852
    **   <li> The number of columns in the table, and
    11853
    **   <li> Which of those columns make up the tables PRIMARY KEY.
    11854
    ** </ul>
    11855
    **
    11856
    ** This function is used to find which columns comprise the PRIMARY KEY of
    11857
    ** the table modified by the change that iterator pIter currently points to.
    11858
    ** If successful, *pabPK is set to point to an array of nCol entries, where
    11859
    ** nCol is the number of columns in the table. Elements of *pabPK are set to
    11860
    ** 0x01 if the corresponding column is part of the tables primary key, or
    11861
    ** 0x00 if it is not.
    11862
    **
    11863
    ** If argument pnCol is not NULL, then *pnCol is set to the number of columns
    11864
    ** in the table.
    11865
    **
    11866
    ** If this function is called when the iterator does not point to a valid
    11867
    ** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise,
    11868
    ** SQLITE_OK is returned and the output variables populated as described
    11869
    ** above.
    11870
    */
    11871
    SQLITE_API int sqlite3changeset_pk(
    11872
      sqlite3_changeset_iter *pIter,  /* Iterator object */
    11873
      unsigned char **pabPK,          /* OUT: Array of boolean - true for PK cols */
    11874
      int *pnCol                      /* OUT: Number of entries in output array */
    11875
    );
    11876
    11877
    /*
    11878
    ** CAPI3REF: Obtain old.* Values From A Changeset Iterator
    11879
    ** METHOD: sqlite3_changeset_iter
    11880
    **
    11881
    ** The pIter argument passed to this function may either be an iterator
    11882
    ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
    11883
    ** created by [sqlite3changeset_start()]. In the latter case, the most recent
    11884
    ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
    11885
    ** Furthermore, it may only be called if the type of change that the iterator
    11886
    ** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise,
    11887
    ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
    11888
    **
    11889
    ** Argument iVal must be greater than or equal to 0, and less than the number
    11890
    ** of columns in the table affected by the current change. Otherwise,
    11891
    ** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
    11892
    **
    11893
    ** If successful, this function sets *ppValue to point to a protected
    11894
    ** sqlite3_value object containing the iVal'th value from the vector of
    11895
    ** original row values stored as part of the UPDATE or DELETE change and
    11896
    ** returns SQLITE_OK. The name of the function comes from the fact that this
    11897
    ** is similar to the "old.*" columns available to update or delete triggers.
    11898
    **
    11899
    ** If some other error occurs (e.g. an OOM condition), an SQLite error code
    11900
    ** is returned and *ppValue is set to NULL.
    11901
    */
    11902
    SQLITE_API int sqlite3changeset_old(
    11903
      sqlite3_changeset_iter *pIter,  /* Changeset iterator */
    11904
      int iVal,                       /* Column number */
    11905
      sqlite3_value **ppValue         /* OUT: Old value (or NULL pointer) */
    11906
    );
    11907
    11908
    /*
    11909
    ** CAPI3REF: Obtain new.* Values From A Changeset Iterator
    11910
    ** METHOD: sqlite3_changeset_iter
    11911
    **
    11912
    ** The pIter argument passed to this function may either be an iterator
    11913
    ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
    11914
    ** created by [sqlite3changeset_start()]. In the latter case, the most recent
    11915
    ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
    11916
    ** Furthermore, it may only be called if the type of change that the iterator
    11917
    ** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise,
    11918
    ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
    11919
    **
    11920
    ** Argument iVal must be greater than or equal to 0, and less than the number
    11921
    ** of columns in the table affected by the current change. Otherwise,
    11922
    ** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
    11923
    **
    11924
    ** If successful, this function sets *ppValue to point to a protected
    11925
    ** sqlite3_value object containing the iVal'th value from the vector of
    11926
    ** new row values stored as part of the UPDATE or INSERT change and
    11927
    ** returns SQLITE_OK. If the change is an UPDATE and does not include
    11928
    ** a new value for the requested column, *ppValue is set to NULL and
    11929
    ** SQLITE_OK returned. The name of the function comes from the fact that
    11930
    ** this is similar to the "new.*" columns available to update or delete
    11931
    ** triggers.
    11932
    **
    11933
    ** If some other error occurs (e.g. an OOM condition), an SQLite error code
    11934
    ** is returned and *ppValue is set to NULL.
    11935
    */
    11936
    SQLITE_API int sqlite3changeset_new(
    11937
      sqlite3_changeset_iter *pIter,  /* Changeset iterator */
    11938
      int iVal,                       /* Column number */
    11939
      sqlite3_value **ppValue         /* OUT: New value (or NULL pointer) */
    11940
    );
    11941
    11942
    /*
    11943
    ** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator
    11944
    ** METHOD: sqlite3_changeset_iter
    11945
    **
    11946
    ** This function should only be used with iterator objects passed to a
    11947
    ** conflict-handler callback by [sqlite3changeset_apply()] with either
    11948
    ** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function
    11949
    ** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue
    11950
    ** is set to NULL.
    11951
    **
    11952
    ** Argument iVal must be greater than or equal to 0, and less than the number
    11953
    ** of columns in the table affected by the current change. Otherwise,
    11954
    ** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
    11955
    **
    11956
    ** If successful, this function sets *ppValue to point to a protected
    11957
    ** sqlite3_value object containing the iVal'th value from the
    11958
    ** "conflicting row" associated with the current conflict-handler callback
    11959
    ** and returns SQLITE_OK.
    11960
    **
    11961
    ** If some other error occurs (e.g. an OOM condition), an SQLite error code
    11962
    ** is returned and *ppValue is set to NULL.
    11963
    */
    11964
    SQLITE_API int sqlite3changeset_conflict(
    11965
      sqlite3_changeset_iter *pIter,  /* Changeset iterator */
    11966
      int iVal,                       /* Column number */
    11967
      sqlite3_value **ppValue         /* OUT: Value from conflicting row */
    11968
    );
    11969
    11970
    /*
    11971
    ** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations
    11972
    ** METHOD: sqlite3_changeset_iter
    11973
    **
    11974
    ** This function may only be called with an iterator passed to an
    11975
    ** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case
    11976
    ** it sets the output variable to the total number of known foreign key
    11977
    ** violations in the destination database and returns SQLITE_OK.
    11978
    **
    11979
    ** In all other cases this function returns SQLITE_MISUSE.
    11980
    */
    11981
    SQLITE_API int sqlite3changeset_fk_conflicts(
    11982
      sqlite3_changeset_iter *pIter,  /* Changeset iterator */
    11983
      int *pnOut                      /* OUT: Number of FK violations */
    11984
    );
    11985
    11986
    11987
    /*
    11988
    ** CAPI3REF: Finalize A Changeset Iterator
    11989
    ** METHOD: sqlite3_changeset_iter
    11990
    **
    11991
    ** This function is used to finalize an iterator allocated with
    11992
    ** [sqlite3changeset_start()].
    11993
    **
    11994
    ** This function should only be called on iterators created using the
    11995
    ** [sqlite3changeset_start()] function. If an application calls this
    11996
    ** function with an iterator passed to a conflict-handler by
    11997
    ** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the
    11998
    ** call has no effect.
    11999
    **
    12000
    ** If an error was encountered within a call to an sqlite3changeset_xxx()
    12001
    ** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an
    12002
    ** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding
    12003
    ** to that error is returned by this function. Otherwise, SQLITE_OK is
    12004
    ** returned. This is to allow the following pattern (pseudo-code):
    12005
    **
    12006
    ** <pre>
    12007
    **   sqlite3changeset_start();
    12008
    **   while( SQLITE_ROW==sqlite3changeset_next() ){
    12009
    **     // Do something with change.
    12010
    **   }
    12011
    **   rc = sqlite3changeset_finalize();
    12012
    **   if( rc!=SQLITE_OK ){
    12013
    **     // An error has occurred
    12014
    **   }
    12015
    ** </pre>
    12016
    */
    12017
    SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter);
    12018
    12019
    /*
    12020
    ** CAPI3REF: Invert A Changeset
    12021
    **
    12022
    ** This function is used to "invert" a changeset object. Applying an inverted
    12023
    ** changeset to a database reverses the effects of applying the uninverted
    12024
    ** changeset. Specifically:
    12025
    **
    12026
    ** <ul>
    12027
    **   <li> Each DELETE change is changed to an INSERT, and
    12028
    **   <li> Each INSERT change is changed to a DELETE, and
    12029
    **   <li> For each UPDATE change, the old.* and new.* values are exchanged.
    12030
    ** </ul>
    12031
    **
    12032
    ** This function does not change the order in which changes appear within
    12033
    ** the changeset. It merely reverses the sense of each individual change.
    12034
    **
    12035
    ** If successful, a pointer to a buffer containing the inverted changeset
    12036
    ** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and
    12037
    ** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are
    12038
    ** zeroed and an SQLite error code returned.
    12039
    **
    12040
    ** It is the responsibility of the caller to eventually call sqlite3_free()
    12041
    ** on the *ppOut pointer to free the buffer allocation following a successful
    12042
    ** call to this function.
    12043
    **
    12044
    ** WARNING/TODO: This function currently assumes that the input is a valid
    12045
    ** changeset. If it is not, the results are undefined.
    12046
    */
    12047
    SQLITE_API int sqlite3changeset_invert(
    12048
      int nIn, const void *pIn,       /* Input changeset */
    12049
      int *pnOut, void **ppOut        /* OUT: Inverse of input */
    12050
    );
    12051
    12052
    /*
    12053
    ** CAPI3REF: Concatenate Two Changeset Objects
    12054
    **
    12055
    ** This function is used to concatenate two changesets, A and B, into a
    12056
    ** single changeset. The result is a changeset equivalent to applying
    12057
    ** changeset A followed by changeset B.
    12058
    **
    12059
    ** This function combines the two input changesets using an
    12060
    ** sqlite3_changegroup object. Calling it produces similar results as the
    12061
    ** following code fragment:
    12062
    **
    12063
    ** <pre>
    12064
    **   sqlite3_changegroup *pGrp;
    12065
    **   rc = sqlite3_changegroup_new(&pGrp);
    12066
    **   if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA);
    12067
    **   if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB);
    12068
    **   if( rc==SQLITE_OK ){
    12069
    **     rc = sqlite3changegroup_output(pGrp, pnOut, ppOut);
    12070
    **   }else{
    12071
    **     *ppOut = 0;
    12072
    **     *pnOut = 0;
    12073
    **   }
    12074
    ** </pre>
    12075
    **
    12076
    ** Refer to the sqlite3_changegroup documentation below for details.
    12077
    */
    12078
    SQLITE_API int sqlite3changeset_concat(
    12079
      int nA,                         /* Number of bytes in buffer pA */
    12080
      void *pA,                       /* Pointer to buffer containing changeset A */
    12081
      int nB,                         /* Number of bytes in buffer pB */
    12082
      void *pB,                       /* Pointer to buffer containing changeset B */
    12083
      int *pnOut,                     /* OUT: Number of bytes in output changeset */
    12084
      void **ppOut                    /* OUT: Buffer containing output changeset */
    12085
    );
    12086
    12087
    /*
    12088
    ** CAPI3REF: Changegroup Handle
    12089
    **
    12090
    ** A changegroup is an object used to combine two or more
    12091
    ** [changesets] or [patchsets]
    12092
    */
    12093
    typedef struct sqlite3_changegroup sqlite3_changegroup;
    12094
    12095
    /*
    12096
    ** CAPI3REF: Create A New Changegroup Object
    12097
    ** CONSTRUCTOR: sqlite3_changegroup
    12098
    **
    12099
    ** An sqlite3_changegroup object is used to combine two or more changesets
    12100
    ** (or patchsets) into a single changeset (or patchset). A single changegroup
    12101
    ** object may combine changesets or patchsets, but not both. The output is
    12102
    ** always in the same format as the input.
    12103
    **
    12104
    ** If successful, this function returns SQLITE_OK and populates (*pp) with
    12105
    ** a pointer to a new sqlite3_changegroup object before returning. The caller
    12106
    ** should eventually free the returned object using a call to
    12107
    ** sqlite3changegroup_delete(). If an error occurs, an SQLite error code
    12108
    ** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL.
    12109
    **
    12110
    ** The usual usage pattern for an sqlite3_changegroup object is as follows:
    12111
    **
    12112
    ** <ul>
    12113
    **   <li> It is created using a call to sqlite3changegroup_new().
    12114
    **
    12115
    **   <li> Zero or more changesets (or patchsets) are added to the object
    12116
    **        by calling sqlite3changegroup_add().
    12117
    **
    12118
    **   <li> The result of combining all input changesets together is obtained
    12119
    **        by the application via a call to sqlite3changegroup_output().
    12120
    **
    12121
    **   <li> The object is deleted using a call to sqlite3changegroup_delete().
    12122
    ** </ul>
    12123
    **
    12124
    ** Any number of calls to add() and output() may be made between the calls to
    12125
    ** new() and delete(), and in any order.
    12126
    **
    12127
    ** As well as the regular sqlite3changegroup_add() and
    12128
    ** sqlite3changegroup_output() functions, also available are the streaming
    12129
    ** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm().
    12130
    */
    12131
    SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp);
    12132
    12133
    /*
    12134
    ** CAPI3REF: Add a Schema to a Changegroup
    12135
    ** METHOD: sqlite3_changegroup_schema
    12136
    **
    12137
    ** This method may be used to optionally enforce the rule that the changesets
    12138
    ** added to the changegroup handle must match the schema of database zDb
    12139
    ** ("main", "temp", or the name of an attached database). If
    12140
    ** sqlite3changegroup_add() is called to add a changeset that is not compatible
    12141
    ** with the configured schema, SQLITE_SCHEMA is returned and the changegroup
    12142
    ** object is left in an undefined state.
    12143
    **
    12144
    ** A changeset schema is considered compatible with the database schema in
    12145
    ** the same way as for sqlite3changeset_apply(). Specifically, for each
    12146
    ** table in the changeset, there exists a database table with:
    12147
    **
    12148
    ** <ul>
    12149
    **   <li> The name identified by the changeset, and
    12150
    **   <li> at least as many columns as recorded in the changeset, and
    12151
    **   <li> the primary key columns in the same position as recorded in
    12152
    **        the changeset.
    12153
    ** </ul>
    12154
    **
    12155
    ** The output of the changegroup object always has the same schema as the
    12156
    ** database nominated using this function. In cases where changesets passed
    12157
    ** to sqlite3changegroup_add() have fewer columns than the corresponding table
    12158
    ** in the database schema, these are filled in using the default column
    12159
    ** values from the database schema. This makes it possible to combined
    12160
    ** changesets that have different numbers of columns for a single table
    12161
    ** within a changegroup, provided that they are otherwise compatible.
    12162
    */
    12163
    SQLITE_API int sqlite3changegroup_schema(sqlite3_changegroup*, sqlite3*, const char *zDb);
    12164
    12165
    /*
    12166
    ** CAPI3REF: Add A Changeset To A Changegroup
    12167
    ** METHOD: sqlite3_changegroup
    12168
    **
    12169
    ** Add all changes within the changeset (or patchset) in buffer pData (size
    12170
    ** nData bytes) to the changegroup.
    12171
    **
    12172
    ** If the buffer contains a patchset, then all prior calls to this function
    12173
    ** on the same changegroup object must also have specified patchsets. Or, if
    12174
    ** the buffer contains a changeset, so must have the earlier calls to this
    12175
    ** function. Otherwise, SQLITE_ERROR is returned and no changes are added
    12176
    ** to the changegroup.
    12177
    **
    12178
    ** Rows within the changeset and changegroup are identified by the values in
    12179
    ** their PRIMARY KEY columns. A change in the changeset is considered to
    12180
    ** apply to the same row as a change already present in the changegroup if
    12181
    ** the two rows have the same primary key.
    12182
    **
    12183
    ** Changes to rows that do not already appear in the changegroup are
    12184
    ** simply copied into it. Or, if both the new changeset and the changegroup
    12185
    ** contain changes that apply to a single row, the final contents of the
    12186
    ** changegroup depends on the type of each change, as follows:
    12187
    **
    12188
    ** <table border=1 style="margin-left:8ex;margin-right:8ex">
    12189
    **   <tr><th style="white-space:pre">Existing Change  </th>
    12190
    **       <th style="white-space:pre">New Change       </th>
    12191
    **       <th>Output Change
    12192
    **   <tr><td>INSERT <td>INSERT <td>
    12193
    **       The new change is ignored. This case does not occur if the new
    12194
    **       changeset was recorded immediately after the changesets already
    12195
    **       added to the changegroup.
    12196
    **   <tr><td>INSERT <td>UPDATE <td>
    12197
    **       The INSERT change remains in the changegroup. The values in the
    12198
    **       INSERT change are modified as if the row was inserted by the
    12199
    **       existing change and then updated according to the new change.
    12200
    **   <tr><td>INSERT <td>DELETE <td>
    12201
    **       The existing INSERT is removed from the changegroup. The DELETE is
    12202
    **       not added.
    12203
    **   <tr><td>UPDATE <td>INSERT <td>
    12204
    **       The new change is ignored. This case does not occur if the new
    12205
    **       changeset was recorded immediately after the changesets already
    12206
    **       added to the changegroup.
    12207
    **   <tr><td>UPDATE <td>UPDATE <td>
    12208
    **       The existing UPDATE remains within the changegroup. It is amended
    12209
    **       so that the accompanying values are as if the row was updated once
    12210
    **       by the existing change and then again by the new change.
    12211
    **   <tr><td>UPDATE <td>DELETE <td>
    12212
    **       The existing UPDATE is replaced by the new DELETE within the
    12213
    **       changegroup.
    12214
    **   <tr><td>DELETE <td>INSERT <td>
    12215
    **       If one or more of the column values in the row inserted by the
    12216
    **       new change differ from those in the row deleted by the existing
    12217
    **       change, the existing DELETE is replaced by an UPDATE within the
    12218
    **       changegroup. Otherwise, if the inserted row is exactly the same
    12219
    **       as the deleted row, the existing DELETE is simply discarded.
    12220
    **   <tr><td>DELETE <td>UPDATE <td>
    12221
    **       The new change is ignored. This case does not occur if the new
    12222
    **       changeset was recorded immediately after the changesets already
    12223
    **       added to the changegroup.
    12224
    **   <tr><td>DELETE <td>DELETE <td>
    12225
    **       The new change is ignored. This case does not occur if the new
    12226
    **       changeset was recorded immediately after the changesets already
    12227
    **       added to the changegroup.
    12228
    ** </table>
    12229
    **
    12230
    ** If the new changeset contains changes to a table that is already present
    12231
    ** in the changegroup, then the number of columns and the position of the
    12232
    ** primary key columns for the table must be consistent. If this is not the
    12233
    ** case, this function fails with SQLITE_SCHEMA. Except, if the changegroup
    12234
    ** object has been configured with a database schema using the
    12235
    ** sqlite3changegroup_schema() API, then it is possible to combine changesets
    12236
    ** with different numbers of columns for a single table, provided that
    12237
    ** they are otherwise compatible.
    12238
    **
    12239
    ** If the input changeset appears to be corrupt and the corruption is
    12240
    ** detected, SQLITE_CORRUPT is returned. Or, if an out-of-memory condition
    12241
    ** occurs during processing, this function returns SQLITE_NOMEM.
    12242
    **
    12243
    ** In all cases, if an error occurs the state of the final contents of the
    12244
    ** changegroup is undefined. If no error occurs, SQLITE_OK is returned.
    12245
    */
    12246
    SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData);
    12247
    12248
    /*
    12249
    ** CAPI3REF: Add A Single Change To A Changegroup
    12250
    ** METHOD: sqlite3_changegroup
    12251
    **
    12252
    ** This function adds the single change currently indicated by the iterator
    12253
    ** passed as the second argument to the changegroup object. The rules for
    12254
    ** adding the change are just as described for [sqlite3changegroup_add()].
    12255
    **
    12256
    ** If the change is successfully added to the changegroup, SQLITE_OK is
    12257
    ** returned. Otherwise, an SQLite error code is returned.
    12258
    **
    12259
    ** The iterator must point to a valid entry when this function is called.
    12260
    ** If it does not, SQLITE_ERROR is returned and no change is added to the
    12261
    ** changegroup. Additionally, the iterator must not have been opened with
    12262
    ** the SQLITE_CHANGESETAPPLY_INVERT flag. In this case SQLITE_ERROR is also
    12263
    ** returned.
    12264
    */
    12265
    SQLITE_API int sqlite3changegroup_add_change(
    12266
      sqlite3_changegroup*,
    12267
      sqlite3_changeset_iter*
    12268
    );
    12269
    12270
    12271
    12272
    /*
    12273
    ** CAPI3REF: Obtain A Composite Changeset From A Changegroup
    12274
    ** METHOD: sqlite3_changegroup
    12275
    **
    12276
    ** Obtain a buffer containing a changeset (or patchset) representing the
    12277
    ** current contents of the changegroup. If the inputs to the changegroup
    12278
    ** were themselves changesets, the output is a changeset. Or, if the
    12279
    ** inputs were patchsets, the output is also a patchset.
    12280
    **
    12281
    ** As with the output of the sqlite3session_changeset() and
    12282
    ** sqlite3session_patchset() functions, all changes related to a single
    12283
    ** table are grouped together in the output of this function. Tables appear
    12284
    ** in the same order as for the very first changeset added to the changegroup.
    12285
    ** If the second or subsequent changesets added to the changegroup contain
    12286
    ** changes for tables that do not appear in the first changeset, they are
    12287
    ** appended onto the end of the output changeset, again in the order in
    12288
    ** which they are first encountered.
    12289
    **
    12290
    ** If an error occurs, an SQLite error code is returned and the output
    12291
    ** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK
    12292
    ** is returned and the output variables are set to the size of and a
    12293
    ** pointer to the output buffer, respectively. In this case it is the
    12294
    ** responsibility of the caller to eventually free the buffer using a
    12295
    ** call to sqlite3_free().
    12296
    */
    12297
    SQLITE_API int sqlite3changegroup_output(
    12298
      sqlite3_changegroup*,
    12299
      int *pnData,                    /* OUT: Size of output buffer in bytes */
    12300
      void **ppData                   /* OUT: Pointer to output buffer */
    12301
    );
    12302
    12303
    /*
    12304
    ** CAPI3REF: Delete A Changegroup Object
    12305
    ** DESTRUCTOR: sqlite3_changegroup
    12306
    */
    12307
    SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*);
    12308
    12309
    /*
    12310
    ** CAPI3REF: Apply A Changeset To A Database
    12311
    **
    12312
    ** Apply a changeset or patchset to a database. These functions attempt to
    12313
    ** update the "main" database attached to handle db with the changes found in
    12314
    ** the changeset passed via the second and third arguments.
    12315
    **
    12316
    ** The fourth argument (xFilter) passed to these functions is the "filter
    12317
    ** callback". If it is not NULL, then for each table affected by at least one
    12318
    ** change in the changeset, the filter callback is invoked with
    12319
    ** the table name as the second argument, and a copy of the context pointer
    12320
    ** passed as the sixth argument as the first. If the "filter callback"
    12321
    ** returns zero, then no attempt is made to apply any changes to the table.
    12322
    ** Otherwise, if the return value is non-zero or the xFilter argument to
    12323
    ** is NULL, all changes related to the table are attempted.
    12324
    **
    12325
    ** For each table that is not excluded by the filter callback, this function
    12326
    ** tests that the target database contains a compatible table. A table is
    12327
    ** considered compatible if all of the following are true:
    12328
    **
    12329
    ** <ul>
    12330
    **   <li> The table has the same name as the name recorded in the
    12331
    **        changeset, and
    12332
    **   <li> The table has at least as many columns as recorded in the
    12333
    **        changeset, and
    12334
    **   <li> The table has primary key columns in the same position as
    12335
    **        recorded in the changeset.
    12336
    ** </ul>
    12337
    **
    12338
    ** If there is no compatible table, it is not an error, but none of the
    12339
    ** changes associated with the table are applied. A warning message is issued
    12340
    ** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most
    12341
    ** one such warning is issued for each table in the changeset.
    12342
    **
    12343
    ** For each change for which there is a compatible table, an attempt is made
    12344
    ** to modify the table contents according to the UPDATE, INSERT or DELETE
    12345
    ** change. If a change cannot be applied cleanly, the conflict handler
    12346
    ** function passed as the fifth argument to sqlite3changeset_apply() may be
    12347
    ** invoked. A description of exactly when the conflict handler is invoked for
    12348
    ** each type of change is below.
    12349
    **
    12350
    ** Unlike the xFilter argument, xConflict may not be passed NULL. The results
    12351
    ** of passing anything other than a valid function pointer as the xConflict
    12352
    ** argument are undefined.
    12353
    **
    12354
    ** Each time the conflict handler function is invoked, it must return one
    12355
    ** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or
    12356
    ** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned
    12357
    ** if the second argument passed to the conflict handler is either
    12358
    ** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler
    12359
    ** returns an illegal value, any changes already made are rolled back and
    12360
    ** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different
    12361
    ** actions are taken by sqlite3changeset_apply() depending on the value
    12362
    ** returned by each invocation of the conflict-handler function. Refer to
    12363
    ** the documentation for the three
    12364
    ** [SQLITE_CHANGESET_OMIT|available return values] for details.
    12365
    **
    12366
    ** <dl>
    12367
    ** <dt>DELETE Changes<dd>
    12368
    **   For each DELETE change, the function checks if the target database
    12369
    **   contains a row with the same primary key value (or values) as the
    12370
    **   original row values stored in the changeset. If it does, and the values
    12371
    **   stored in all non-primary key columns also match the values stored in
    12372
    **   the changeset the row is deleted from the target database.
    12373
    **
    12374
    **   If a row with matching primary key values is found, but one or more of
    12375
    **   the non-primary key fields contains a value different from the original
    12376
    **   row value stored in the changeset, the conflict-handler function is
    12377
    **   invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the
    12378
    **   database table has more columns than are recorded in the changeset,
    12379
    **   only the values of those non-primary key fields are compared against
    12380
    **   the current database contents - any trailing database table columns
    12381
    **   are ignored.
    12382
    **
    12383
    **   If no row with matching primary key values is found in the database,
    12384
    **   the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
    12385
    **   passed as the second argument.
    12386
    **
    12387
    **   If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT
    12388
    **   (which can only happen if a foreign key constraint is violated), the
    12389
    **   conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT]
    12390
    **   passed as the second argument. This includes the case where the DELETE
    12391
    **   operation is attempted because an earlier call to the conflict handler
    12392
    **   function returned [SQLITE_CHANGESET_REPLACE].
    12393
    **
    12394
    ** <dt>INSERT Changes<dd>
    12395
    **   For each INSERT change, an attempt is made to insert the new row into
    12396
    **   the database. If the changeset row contains fewer fields than the
    12397
    **   database table, the trailing fields are populated with their default
    12398
    **   values.
    12399
    **
    12400
    **   If the attempt to insert the row fails because the database already
    12401
    **   contains a row with the same primary key values, the conflict handler
    12402
    **   function is invoked with the second argument set to
    12403
    **   [SQLITE_CHANGESET_CONFLICT].
    12404
    **
    12405
    **   If the attempt to insert the row fails because of some other constraint
    12406
    **   violation (e.g. NOT NULL or UNIQUE), the conflict handler function is
    12407
    **   invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT].
    12408
    **   This includes the case where the INSERT operation is re-attempted because
    12409
    **   an earlier call to the conflict handler function returned
    12410
    **   [SQLITE_CHANGESET_REPLACE].
    12411
    **
    12412
    ** <dt>UPDATE Changes<dd>
    12413
    **   For each UPDATE change, the function checks if the target database
    12414
    **   contains a row with the same primary key value (or values) as the
    12415
    **   original row values stored in the changeset. If it does, and the values
    12416
    **   stored in all modified non-primary key columns also match the values
    12417
    **   stored in the changeset the row is updated within the target database.
    12418
    **
    12419
    **   If a row with matching primary key values is found, but one or more of
    12420
    **   the modified non-primary key fields contains a value different from an
    12421
    **   original row value stored in the changeset, the conflict-handler function
    12422
    **   is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since
    12423
    **   UPDATE changes only contain values for non-primary key fields that are
    12424
    **   to be modified, only those fields need to match the original values to
    12425
    **   avoid the SQLITE_CHANGESET_DATA conflict-handler callback.
    12426
    **
    12427
    **   If no row with matching primary key values is found in the database,
    12428
    **   the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
    12429
    **   passed as the second argument.
    12430
    **
    12431
    **   If the UPDATE operation is attempted, but SQLite returns
    12432
    **   SQLITE_CONSTRAINT, the conflict-handler function is invoked with
    12433
    **   [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument.
    12434
    **   This includes the case where the UPDATE operation is attempted after
    12435
    **   an earlier call to the conflict handler function returned
    12436
    **   [SQLITE_CHANGESET_REPLACE].
    12437
    ** </dl>
    12438
    **
    12439
    ** It is safe to execute SQL statements, including those that write to the
    12440
    ** table that the callback related to, from within the xConflict callback.
    12441
    ** This can be used to further customize the application's conflict
    12442
    ** resolution strategy.
    12443
    **
    12444
    ** All changes made by these functions are enclosed in a savepoint transaction.
    12445
    ** If any other error (aside from a constraint failure when attempting to
    12446
    ** write to the target database) occurs, then the savepoint transaction is
    12447
    ** rolled back, restoring the target database to its original state, and an
    12448
    ** SQLite error code returned.
    12449
    **
    12450
    ** If the output parameters (ppRebase) and (pnRebase) are non-NULL and
    12451
    ** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2()
    12452
    ** may set (*ppRebase) to point to a "rebase" that may be used with the
    12453
    ** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase)
    12454
    ** is set to the size of the buffer in bytes. It is the responsibility of the
    12455
    ** caller to eventually free any such buffer using sqlite3_free(). The buffer
    12456
    ** is only allocated and populated if one or more conflicts were encountered
    12457
    ** while applying the patchset. See comments surrounding the sqlite3_rebaser
    12458
    ** APIs for further details.
    12459
    **
    12460
    ** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent
    12461
    ** may be modified by passing a combination of
    12462
    ** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter.
    12463
    **
    12464
    ** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b>
    12465
    ** and therefore subject to change.
    12466
    */
    12467
    SQLITE_API int sqlite3changeset_apply(
    12468
      sqlite3 *db,                    /* Apply change to "main" db of this handle */
    12469
      int nChangeset,                 /* Size of changeset in bytes */
    12470
      void *pChangeset,               /* Changeset blob */
    12471
      int(*xFilter)(
    12472
        void *pCtx,                   /* Copy of sixth arg to _apply() */
    12473
        const char *zTab              /* Table name */
    12474
      ),
    12475
      int(*xConflict)(
    12476
        void *pCtx,                   /* Copy of sixth arg to _apply() */
    12477
        int eConflict,                /* DATA, MISSING, CONFLICT, CONSTRAINT */
    12478
        sqlite3_changeset_iter *p     /* Handle describing change and conflict */
    12479
      ),
    12480
      void *pCtx                      /* First argument passed to xConflict */
    12481
    );
    12482
    SQLITE_API int sqlite3changeset_apply_v2(
    12483
      sqlite3 *db,                    /* Apply change to "main" db of this handle */
    12484
      int nChangeset,                 /* Size of changeset in bytes */
    12485
      void *pChangeset,               /* Changeset blob */
    12486
      int(*xFilter)(
    12487
        void *pCtx,                   /* Copy of sixth arg to _apply() */
    12488
        const char *zTab              /* Table name */
    12489
      ),
    12490
      int(*xConflict)(
    12491
        void *pCtx,                   /* Copy of sixth arg to _apply() */
    12492
        int eConflict,                /* DATA, MISSING, CONFLICT, CONSTRAINT */
    12493
        sqlite3_changeset_iter *p     /* Handle describing change and conflict */
    12494
      ),
    12495
      void *pCtx,                     /* First argument passed to xConflict */
    12496
      void **ppRebase, int *pnRebase, /* OUT: Rebase data */
    12497
      int flags                       /* SESSION_CHANGESETAPPLY_* flags */
    12498
    );
    12499
    12500
    /*
    12501
    ** CAPI3REF: Flags for sqlite3changeset_apply_v2
    12502
    **
    12503
    ** The following flags may passed via the 9th parameter to
    12504
    ** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]:
    12505
    **
    12506
    ** <dl>
    12507
    ** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd>
    12508
    **   Usually, the sessions module encloses all operations performed by
    12509
    **   a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The
    12510
    **   SAVEPOINT is committed if the changeset or patchset is successfully
    12511
    **   applied, or rolled back if an error occurs. Specifying this flag
    12512
    **   causes the sessions module to omit this savepoint. In this case, if the
    12513
    **   caller has an open transaction or savepoint when apply_v2() is called,
    12514
    **   it may revert the partially applied changeset by rolling it back.
    12515
    **
    12516
    ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd>
    12517
    **   Invert the changeset before applying it. This is equivalent to inverting
    12518
    **   a changeset using sqlite3changeset_invert() before applying it. It is
    12519
    **   an error to specify this flag with a patchset.
    12520
    **
    12521
    ** <dt>SQLITE_CHANGESETAPPLY_IGNORENOOP <dd>
    12522
    **   Do not invoke the conflict handler callback for any changes that
    12523
    **   would not actually modify the database even if they were applied.
    12524
    **   Specifically, this means that the conflict handler is not invoked
    12525
    **   for:
    12526
    **    <ul>
    12527
    **    <li>a delete change if the row being deleted cannot be found,
    12528
    **    <li>an update change if the modified fields are already set to
    12529
    **        their new values in the conflicting row, or
    12530
    **    <li>an insert change if all fields of the conflicting row match
    12531
    **        the row being inserted.
    12532
    **    </ul>
    12533
    **
    12534
    ** <dt>SQLITE_CHANGESETAPPLY_FKNOACTION <dd>
    12535
    **   If this flag it set, then all foreign key constraints in the target
    12536
    **   database behave as if they were declared with "ON UPDATE NO ACTION ON
    12537
    **   DELETE NO ACTION", even if they are actually CASCADE, RESTRICT, SET NULL
    12538
    **   or SET DEFAULT.
    12539
    */
    12540
    #define SQLITE_CHANGESETAPPLY_NOSAVEPOINT   0x0001
    12541
    #define SQLITE_CHANGESETAPPLY_INVERT        0x0002
    12542
    #define SQLITE_CHANGESETAPPLY_IGNORENOOP    0x0004
    12543
    #define SQLITE_CHANGESETAPPLY_FKNOACTION    0x0008
    12544
    12545
    /*
    12546
    ** CAPI3REF: Constants Passed To The Conflict Handler
    12547
    **
    12548
    ** Values that may be passed as the second argument to a conflict-handler.
    12549
    **
    12550
    ** <dl>
    12551
    ** <dt>SQLITE_CHANGESET_DATA<dd>
    12552
    **   The conflict handler is invoked with CHANGESET_DATA as the second argument
    12553
    **   when processing a DELETE or UPDATE change if a row with the required
    12554
    **   PRIMARY KEY fields is present in the database, but one or more other
    12555
    **   (non primary-key) fields modified by the update do not contain the
    12556
    **   expected "before" values.
    12557
    **
    12558
    **   The conflicting row, in this case, is the database row with the matching
    12559
    **   primary key.
    12560
    **
    12561
    ** <dt>SQLITE_CHANGESET_NOTFOUND<dd>
    12562
    **   The conflict handler is invoked with CHANGESET_NOTFOUND as the second
    12563
    **   argument when processing a DELETE or UPDATE change if a row with the
    12564
    **   required PRIMARY KEY fields is not present in the database.
    12565
    **
    12566
    **   There is no conflicting row in this case. The results of invoking the
    12567
    **   sqlite3changeset_conflict() API are undefined.
    12568
    **
    12569
    ** <dt>SQLITE_CHANGESET_CONFLICT<dd>
    12570
    **   CHANGESET_CONFLICT is passed as the second argument to the conflict
    12571
    **   handler while processing an INSERT change if the operation would result
    12572
    **   in duplicate primary key values.
    12573
    **
    12574
    **   The conflicting row in this case is the database row with the matching
    12575
    **   primary key.
    12576
    **
    12577
    ** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd>
    12578
    **   If foreign key handling is enabled, and applying a changeset leaves the
    12579
    **   database in a state containing foreign key violations, the conflict
    12580
    **   handler is invoked with CHANGESET_FOREIGN_KEY as the second argument
    12581
    **   exactly once before the changeset is committed. If the conflict handler
    12582
    **   returns CHANGESET_OMIT, the changes, including those that caused the
    12583
    **   foreign key constraint violation, are committed. Or, if it returns
    12584
    **   CHANGESET_ABORT, the changeset is rolled back.
    12585
    **
    12586
    **   No current or conflicting row information is provided. The only function
    12587
    **   it is possible to call on the supplied sqlite3_changeset_iter handle
    12588
    **   is sqlite3changeset_fk_conflicts().
    12589
    **
    12590
    ** <dt>SQLITE_CHANGESET_CONSTRAINT<dd>
    12591
    **   If any other constraint violation occurs while applying a change (i.e.
    12592
    **   a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is
    12593
    **   invoked with CHANGESET_CONSTRAINT as the second argument.
    12594
    **
    12595
    **   There is no conflicting row in this case. The results of invoking the
    12596
    **   sqlite3changeset_conflict() API are undefined.
    12597
    **
    12598
    ** </dl>
    12599
    */
    12600
    #define SQLITE_CHANGESET_DATA        1
    12601
    #define SQLITE_CHANGESET_NOTFOUND    2
    12602
    #define SQLITE_CHANGESET_CONFLICT    3
    12603
    #define SQLITE_CHANGESET_CONSTRAINT  4
    12604
    #define SQLITE_CHANGESET_FOREIGN_KEY 5
    12605
    12606
    /*
    12607
    ** CAPI3REF: Constants Returned By The Conflict Handler
    12608
    **
    12609
    ** A conflict handler callback must return one of the following three values.
    12610
    **
    12611
    ** <dl>
    12612
    ** <dt>SQLITE_CHANGESET_OMIT<dd>
    12613
    **   If a conflict handler returns this value no special action is taken. The
    12614
    **   change that caused the conflict is not applied. The session module
    12615
    **   continues to the next change in the changeset.
    12616
    **
    12617
    ** <dt>SQLITE_CHANGESET_REPLACE<dd>
    12618
    **   This value may only be returned if the second argument to the conflict
    12619
    **   handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this
    12620
    **   is not the case, any changes applied so far are rolled back and the
    12621
    **   call to sqlite3changeset_apply() returns SQLITE_MISUSE.
    12622
    **
    12623
    **   If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict
    12624
    **   handler, then the conflicting row is either updated or deleted, depending
    12625
    **   on the type of change.
    12626
    **
    12627
    **   If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict
    12628
    **   handler, then the conflicting row is removed from the database and a
    12629
    **   second attempt to apply the change is made. If this second attempt fails,
    12630
    **   the original row is restored to the database before continuing.
    12631
    **
    12632
    ** <dt>SQLITE_CHANGESET_ABORT<dd>
    12633
    **   If this value is returned, any changes applied so far are rolled back
    12634
    **   and the call to sqlite3changeset_apply() returns SQLITE_ABORT.
    12635
    ** </dl>
    12636
    */
    12637
    #define SQLITE_CHANGESET_OMIT       0
    12638
    #define SQLITE_CHANGESET_REPLACE    1
    12639
    #define SQLITE_CHANGESET_ABORT      2
    12640
    12641
    /*
    12642
    ** CAPI3REF: Rebasing changesets
    12643
    ** EXPERIMENTAL
    12644
    **
    12645
    ** Suppose there is a site hosting a database in state S0. And that
    12646
    ** modifications are made that move that database to state S1 and a
    12647
    ** changeset recorded (the "local" changeset). Then, a changeset based
    12648
    ** on S0 is received from another site (the "remote" changeset) and
    12649
    ** applied to the database. The database is then in state
    12650
    ** (S1+"remote"), where the exact state depends on any conflict
    12651
    ** resolution decisions (OMIT or REPLACE) made while applying "remote".
    12652
    ** Rebasing a changeset is to update it to take those conflict
    12653
    ** resolution decisions into account, so that the same conflicts
    12654
    ** do not have to be resolved elsewhere in the network.
    12655
    **
    12656
    ** For example, if both the local and remote changesets contain an
    12657
    ** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)":
    12658
    **
    12659
    **   local:  INSERT INTO t1 VALUES(1, 'v1');
    12660
    **   remote: INSERT INTO t1 VALUES(1, 'v2');
    12661
    **
    12662
    ** and the conflict resolution is REPLACE, then the INSERT change is
    12663
    ** removed from the local changeset (it was overridden). Or, if the
    12664
    ** conflict resolution was "OMIT", then the local changeset is modified
    12665
    ** to instead contain:
    12666
    **
    12667
    **           UPDATE t1 SET b = 'v2' WHERE a=1;
    12668
    **
    12669
    ** Changes within the local changeset are rebased as follows:
    12670
    **
    12671
    ** <dl>
    12672
    ** <dt>Local INSERT<dd>
    12673
    **   This may only conflict with a remote INSERT. If the conflict
    12674
    **   resolution was OMIT, then add an UPDATE change to the rebased
    12675
    **   changeset. Or, if the conflict resolution was REPLACE, add
    12676
    **   nothing to the rebased changeset.
    12677
    **
    12678
    ** <dt>Local DELETE<dd>
    12679
    **   This may conflict with a remote UPDATE or DELETE. In both cases the
    12680
    **   only possible resolution is OMIT. If the remote operation was a
    12681
    **   DELETE, then add no change to the rebased changeset. If the remote
    12682
    **   operation was an UPDATE, then the old.* fields of change are updated
    12683
    **   to reflect the new.* values in the UPDATE.
    12684
    **
    12685
    ** <dt>Local UPDATE<dd>
    12686
    **   This may conflict with a remote UPDATE or DELETE. If it conflicts
    12687
    **   with a DELETE, and the conflict resolution was OMIT, then the update
    12688
    **   is changed into an INSERT. Any undefined values in the new.* record
    12689
    **   from the update change are filled in using the old.* values from
    12690
    **   the conflicting DELETE. Or, if the conflict resolution was REPLACE,
    12691
    **   the UPDATE change is simply omitted from the rebased changeset.
    12692
    **
    12693
    **   If conflict is with a remote UPDATE and the resolution is OMIT, then
    12694
    **   the old.* values are rebased using the new.* values in the remote
    12695
    **   change. Or, if the resolution is REPLACE, then the change is copied
    12696
    **   into the rebased changeset with updates to columns also updated by
    12697
    **   the conflicting remote UPDATE removed. If this means no columns would
    12698
    **   be updated, the change is omitted.
    12699
    ** </dl>
    12700
    **
    12701
    ** A local change may be rebased against multiple remote changes
    12702
    ** simultaneously. If a single key is modified by multiple remote
    12703
    ** changesets, they are combined as follows before the local changeset
    12704
    ** is rebased:
    12705
    **
    12706
    ** <ul>
    12707
    **    <li> If there has been one or more REPLACE resolutions on a
    12708
    **         key, it is rebased according to a REPLACE.
    12709
    **
    12710
    **    <li> If there have been no REPLACE resolutions on a key, then
    12711
    **         the local changeset is rebased according to the most recent
    12712
    **         of the OMIT resolutions.
    12713
    ** </ul>
    12714
    **
    12715
    ** Note that conflict resolutions from multiple remote changesets are
    12716
    ** combined on a per-field basis, not per-row. This means that in the
    12717
    ** case of multiple remote UPDATE operations, some fields of a single
    12718
    ** local change may be rebased for REPLACE while others are rebased for
    12719
    ** OMIT.
    12720
    **
    12721
    ** In order to rebase a local changeset, the remote changeset must first
    12722
    ** be applied to the local database using sqlite3changeset_apply_v2() and
    12723
    ** the buffer of rebase information captured. Then:
    12724
    **
    12725
    ** <ol>
    12726
    **   <li> An sqlite3_rebaser object is created by calling
    12727
    **        sqlite3rebaser_create().
    12728
    **   <li> The new object is configured with the rebase buffer obtained from
    12729
    **        sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure().
    12730
    **        If the local changeset is to be rebased against multiple remote
    12731
    **        changesets, then sqlite3rebaser_configure() should be called
    12732
    **        multiple times, in the same order that the multiple
    12733
    **        sqlite3changeset_apply_v2() calls were made.
    12734
    **   <li> Each local changeset is rebased by calling sqlite3rebaser_rebase().
    12735
    **   <li> The sqlite3_rebaser object is deleted by calling
    12736
    **        sqlite3rebaser_delete().
    12737
    ** </ol>
    12738
    */
    12739
    typedef struct sqlite3_rebaser sqlite3_rebaser;
    12740
    12741
    /*
    12742
    ** CAPI3REF: Create a changeset rebaser object.
    12743
    ** EXPERIMENTAL
    12744
    **
    12745
    ** Allocate a new changeset rebaser object. If successful, set (*ppNew) to
    12746
    ** point to the new object and return SQLITE_OK. Otherwise, if an error
    12747
    ** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew)
    12748
    ** to NULL.
    12749
    */
    12750
    SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew);
    12751
    12752
    /*
    12753
    ** CAPI3REF: Configure a changeset rebaser object.
    12754
    ** EXPERIMENTAL
    12755
    **
    12756
    ** Configure the changeset rebaser object to rebase changesets according
    12757
    ** to the conflict resolutions described by buffer pRebase (size nRebase
    12758
    ** bytes), which must have been obtained from a previous call to
    12759
    ** sqlite3changeset_apply_v2().
    12760
    */
    12761
    SQLITE_API int sqlite3rebaser_configure(
    12762
      sqlite3_rebaser*,
    12763
      int nRebase, const void *pRebase
    12764
    );
    12765
    12766
    /*
    12767
    ** CAPI3REF: Rebase a changeset
    12768
    ** EXPERIMENTAL
    12769
    **
    12770
    ** Argument pIn must point to a buffer containing a changeset nIn bytes
    12771
    ** in size. This function allocates and populates a buffer with a copy
    12772
    ** of the changeset rebased according to the configuration of the
    12773
    ** rebaser object passed as the first argument. If successful, (*ppOut)
    12774
    ** is set to point to the new buffer containing the rebased changeset and
    12775
    ** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the
    12776
    ** responsibility of the caller to eventually free the new buffer using
    12777
    ** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut)
    12778
    ** are set to zero and an SQLite error code returned.
    12779
    */
    12780
    SQLITE_API int sqlite3rebaser_rebase(
    12781
      sqlite3_rebaser*,
    12782
      int nIn, const void *pIn,
    12783
      int *pnOut, void **ppOut
    12784
    );
    12785
    12786
    /*
    12787
    ** CAPI3REF: Delete a changeset rebaser object.
    12788
    ** EXPERIMENTAL
    12789
    **
    12790
    ** Delete the changeset rebaser object and all associated resources. There
    12791
    ** should be one call to this function for each successful invocation
    12792
    ** of sqlite3rebaser_create().
    12793
    */
    12794
    SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p);
    12795
    12796
    /*
    12797
    ** CAPI3REF: Streaming Versions of API functions.
    12798
    **
    12799
    ** The six streaming API xxx_strm() functions serve similar purposes to the
    12800
    ** corresponding non-streaming API functions:
    12801
    **
    12802
    ** <table border=1 style="margin-left:8ex;margin-right:8ex">
    12803
    **   <tr><th>Streaming function<th>Non-streaming equivalent</th>
    12804
    **   <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply]
    12805
    **   <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2]
    12806
    **   <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat]
    12807
    **   <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert]
    12808
    **   <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start]
    12809
    **   <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset]
    12810
    **   <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset]
    12811
    ** </table>
    12812
    **
    12813
    ** Non-streaming functions that accept changesets (or patchsets) as input
    12814
    ** require that the entire changeset be stored in a single buffer in memory.
    12815
    ** Similarly, those that return a changeset or patchset do so by returning
    12816
    ** a pointer to a single large buffer allocated using sqlite3_malloc().
    12817
    ** Normally this is convenient. However, if an application running in a
    12818
    ** low-memory environment is required to handle very large changesets, the
    12819
    ** large contiguous memory allocations required can become onerous.
    12820
    **
    12821
    ** In order to avoid this problem, instead of a single large buffer, input
    12822
    ** is passed to a streaming API functions by way of a callback function that
    12823
    ** the sessions module invokes to incrementally request input data as it is
    12824
    ** required. In all cases, a pair of API function parameters such as
    12825
    **
    12826
    **  <pre>
    12827
    **  &nbsp;     int nChangeset,
    12828
    **  &nbsp;     void *pChangeset,
    12829
    **  </pre>
    12830
    **
    12831
    ** Is replaced by:
    12832
    **
    12833
    **  <pre>
    12834
    **  &nbsp;     int (*xInput)(void *pIn, void *pData, int *pnData),
    12835
    **  &nbsp;     void *pIn,
    12836
    **  </pre>
    12837
    **
    12838
    ** Each time the xInput callback is invoked by the sessions module, the first
    12839
    ** argument passed is a copy of the supplied pIn context pointer. The second
    12840
    ** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no
    12841
    ** error occurs the xInput method should copy up to (*pnData) bytes of data
    12842
    ** into the buffer and set (*pnData) to the actual number of bytes copied
    12843
    ** before returning SQLITE_OK. If the input is completely exhausted, (*pnData)
    12844
    ** should be set to zero to indicate this. Or, if an error occurs, an SQLite
    12845
    ** error code should be returned. In all cases, if an xInput callback returns
    12846
    ** an error, all processing is abandoned and the streaming API function
    12847
    ** returns a copy of the error code to the caller.
    12848
    **
    12849
    ** In the case of sqlite3changeset_start_strm(), the xInput callback may be
    12850
    ** invoked by the sessions module at any point during the lifetime of the
    12851
    ** iterator. If such an xInput callback returns an error, the iterator enters
    12852
    ** an error state, whereby all subsequent calls to iterator functions
    12853
    ** immediately fail with the same error code as returned by xInput.
    12854
    **
    12855
    ** Similarly, streaming API functions that return changesets (or patchsets)
    12856
    ** return them in chunks by way of a callback function instead of via a
    12857
    ** pointer to a single large buffer. In this case, a pair of parameters such
    12858
    ** as:
    12859
    **
    12860
    **  <pre>
    12861
    **  &nbsp;     int *pnChangeset,
    12862
    **  &nbsp;     void **ppChangeset,
    12863
    **  </pre>
    12864
    **
    12865
    ** Is replaced by:
    12866
    **
    12867
    **  <pre>
    12868
    **  &nbsp;     int (*xOutput)(void *pOut, const void *pData, int nData),
    12869
    **  &nbsp;     void *pOut
    12870
    **  </pre>
    12871
    **
    12872
    ** The xOutput callback is invoked zero or more times to return data to
    12873
    ** the application. The first parameter passed to each call is a copy of the
    12874
    ** pOut pointer supplied by the application. The second parameter, pData,
    12875
    ** points to a buffer nData bytes in size containing the chunk of output
    12876
    ** data being returned. If the xOutput callback successfully processes the
    12877
    ** supplied data, it should return SQLITE_OK to indicate success. Otherwise,
    12878
    ** it should return some other SQLite error code. In this case processing
    12879
    ** is immediately abandoned and the streaming API function returns a copy
    12880
    ** of the xOutput error code to the application.
    12881
    **
    12882
    ** The sessions module never invokes an xOutput callback with the third
    12883
    ** parameter set to a value less than or equal to zero. Other than this,
    12884
    ** no guarantees are made as to the size of the chunks of data returned.
    12885
    */
    12886
    SQLITE_API int sqlite3changeset_apply_strm(
    12887
      sqlite3 *db,                    /* Apply change to "main" db of this handle */
    12888
      int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
    12889
      void *pIn,                                          /* First arg for xInput */
    12890
      int(*xFilter)(
    12891
        void *pCtx,                   /* Copy of sixth arg to _apply() */
    12892
        const char *zTab              /* Table name */
    12893
      ),
    12894
      int(*xConflict)(
    12895
        void *pCtx,                   /* Copy of sixth arg to _apply() */
    12896
        int eConflict,                /* DATA, MISSING, CONFLICT, CONSTRAINT */
    12897
        sqlite3_changeset_iter *p     /* Handle describing change and conflict */
    12898
      ),
    12899
      void *pCtx                      /* First argument passed to xConflict */
    12900
    );
    12901
    SQLITE_API int sqlite3changeset_apply_v2_strm(
    12902
      sqlite3 *db,                    /* Apply change to "main" db of this handle */
    12903
      int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
    12904
      void *pIn,                                          /* First arg for xInput */
    12905
      int(*xFilter)(
    12906
        void *pCtx,                   /* Copy of sixth arg to _apply() */
    12907
        const char *zTab              /* Table name */
    12908
      ),
    12909
      int(*xConflict)(
    12910
        void *pCtx,                   /* Copy of sixth arg to _apply() */
    12911
        int eConflict,                /* DATA, MISSING, CONFLICT, CONSTRAINT */
    12912
        sqlite3_changeset_iter *p     /* Handle describing change and conflict */
    12913
      ),
    12914
      void *pCtx,                     /* First argument passed to xConflict */
    12915
      void **ppRebase, int *pnRebase,
    12916
      int flags
    12917
    );
    12918
    SQLITE_API int sqlite3changeset_concat_strm(
    12919
      int (*xInputA)(void *pIn, void *pData, int *pnData),
    12920
      void *pInA,
    12921
      int (*xInputB)(void *pIn, void *pData, int *pnData),
    12922
      void *pInB,
    12923
      int (*xOutput)(void *pOut, const void *pData, int nData),
    12924
      void *pOut
    12925
    );
    12926
    SQLITE_API int sqlite3changeset_invert_strm(
    12927
      int (*xInput)(void *pIn, void *pData, int *pnData),
    12928
      void *pIn,
    12929
      int (*xOutput)(void *pOut, const void *pData, int nData),
    12930
      void *pOut
    12931
    );
    12932
    SQLITE_API int sqlite3changeset_start_strm(
    12933
      sqlite3_changeset_iter **pp,
    12934
      int (*xInput)(void *pIn, void *pData, int *pnData),
    12935
      void *pIn
    12936
    );
    12937
    SQLITE_API int sqlite3changeset_start_v2_strm(
    12938
      sqlite3_changeset_iter **pp,
    12939
      int (*xInput)(void *pIn, void *pData, int *pnData),
    12940
      void *pIn,
    12941
      int flags
    12942
    );
    12943
    SQLITE_API int sqlite3session_changeset_strm(
    12944
      sqlite3_session *pSession,
    12945
      int (*xOutput)(void *pOut, const void *pData, int nData),
    12946
      void *pOut
    12947
    );
    12948
    SQLITE_API int sqlite3session_patchset_strm(
    12949
      sqlite3_session *pSession,
    12950
      int (*xOutput)(void *pOut, const void *pData, int nData),
    12951
      void *pOut
    12952
    );
    12953
    SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*,
    12954
        int (*xInput)(void *pIn, void *pData, int *pnData),
    12955
        void *pIn
    12956
    );
    12957
    SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*,
    12958
        int (*xOutput)(void *pOut, const void *pData, int nData),
    12959
        void *pOut
    12960
    );
    12961
    SQLITE_API int sqlite3rebaser_rebase_strm(
    12962
      sqlite3_rebaser *pRebaser,
    12963
      int (*xInput)(void *pIn, void *pData, int *pnData),
    12964
      void *pIn,
    12965
      int (*xOutput)(void *pOut, const void *pData, int nData),
    12966
      void *pOut
    12967
    );
    12968
    12969
    /*
    12970
    ** CAPI3REF: Configure global parameters
    12971
    **
    12972
    ** The sqlite3session_config() interface is used to make global configuration
    12973
    ** changes to the sessions module in order to tune it to the specific needs
    12974
    ** of the application.
    12975
    **
    12976
    ** The sqlite3session_config() interface is not threadsafe. If it is invoked
    12977
    ** while any other thread is inside any other sessions method then the
    12978
    ** results are undefined. Furthermore, if it is invoked after any sessions
    12979
    ** related objects have been created, the results are also undefined.
    12980
    **
    12981
    ** The first argument to the sqlite3session_config() function must be one
    12982
    ** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The
    12983
    ** interpretation of the (void*) value passed as the second parameter and
    12984
    ** the effect of calling this function depends on the value of the first
    12985
    ** parameter.
    12986
    **
    12987
    ** <dl>
    12988
    ** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd>
    12989
    **    By default, the sessions module streaming interfaces attempt to input
    12990
    **    and output data in approximately 1 KiB chunks. This operand may be used
    12991
    **    to set and query the value of this configuration setting. The pointer
    12992
    **    passed as the second argument must point to a value of type (int).
    12993
    **    If this value is greater than 0, it is used as the new streaming data
    12994
    **    chunk size for both input and output. Before returning, the (int) value
    12995
    **    pointed to by pArg is set to the final value of the streaming interface
    12996
    **    chunk size.
    12997
    ** </dl>
    12998
    **
    12999
    ** This function returns SQLITE_OK if successful, or an SQLite error code
    13000
    ** otherwise.
    13001
    */
    13002
    SQLITE_API int sqlite3session_config(int op, void *pArg);
    13003
    13004
    /*
    13005
    ** CAPI3REF: Values for sqlite3session_config().
    13006
    */
    13007
    #define SQLITE_SESSION_CONFIG_STRMSIZE 1
    13008
    13009
    /*
    13010
    ** Make sure we can call this stuff from C++.
    13011
    */
    13012
    #ifdef __cplusplus
    13013
    }
    13014
    #endif
    13015
    13016
    #endif  /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */
    13017
    13018
    /******** End of sqlite3session.h *********/
    13019
    /******** Begin file fts5.h *********/
    13020
    /*
    13021
    ** 2014 May 31
    13022
    **
    13023
    ** The author disclaims copyright to this source code.  In place of
    13024
    ** a legal notice, here is a blessing:
    13025
    **
    13026
    **    May you do good and not evil.
    13027
    **    May you find forgiveness for yourself and forgive others.
    13028
    **    May you share freely, never taking more than you give.
    13029
    **
    13030
    ******************************************************************************
    13031
    **
    13032
    ** Interfaces to extend FTS5. Using the interfaces defined in this file,
    13033
    ** FTS5 may be extended with:
    13034
    **
    13035
    **     * custom tokenizers, and
    13036
    **     * custom auxiliary functions.
    13037
    */
    13038
    13039
    13040
    #ifndef _FTS5_H
    13041
    #define _FTS5_H
    13042
    13043
    13044
    #ifdef __cplusplus
    13045
    extern "C" {
    13046
    #endif
    13047
    13048
    /*************************************************************************
    13049
    ** CUSTOM AUXILIARY FUNCTIONS
    13050
    **
    13051
    ** Virtual table implementations may overload SQL functions by implementing
    13052
    ** the sqlite3_module.xFindFunction() method.
    13053
    */
    13054
    13055
    typedef struct Fts5ExtensionApi Fts5ExtensionApi;
    13056
    typedef struct Fts5Context Fts5Context;
    13057
    typedef struct Fts5PhraseIter Fts5PhraseIter;
    13058
    13059
    typedef void (*fts5_extension_function)(
    13060
      const Fts5ExtensionApi *pApi,   /* API offered by current FTS version */
    13061
      Fts5Context *pFts,              /* First arg to pass to pApi functions */
    13062
      sqlite3_context *pCtx,          /* Context for returning result/error */
    13063
      int nVal,                       /* Number of values in apVal[] array */
    13064
      sqlite3_value **apVal           /* Array of trailing arguments */
    13065
    );
    13066
    13067
    struct Fts5PhraseIter {
    13068
      const unsigned char *a;
    13069
      const unsigned char *b;
    13070
    };
    13071
    13072
    /*
    13073
    ** EXTENSION API FUNCTIONS
    13074
    **
    13075
    ** xUserData(pFts):
    13076
    **   Return a copy of the pUserData pointer passed to the xCreateFunction()
    13077
    **   API when the extension function was registered.
    13078
    **
    13079
    ** xColumnTotalSize(pFts, iCol, pnToken):
    13080
    **   If parameter iCol is less than zero, set output variable *pnToken
    13081
    **   to the total number of tokens in the FTS5 table. Or, if iCol is
    13082
    **   non-negative but less than the number of columns in the table, return
    13083
    **   the total number of tokens in column iCol, considering all rows in
    13084
    **   the FTS5 table.
    13085
    **
    13086
    **   If parameter iCol is greater than or equal to the number of columns
    13087
    **   in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
    13088
    **   an OOM condition or IO error), an appropriate SQLite error code is
    13089
    **   returned.
    13090
    **
    13091
    ** xColumnCount(pFts):
    13092
    **   Return the number of columns in the table.
    13093
    **
    13094
    ** xColumnSize(pFts, iCol, pnToken):
    13095
    **   If parameter iCol is less than zero, set output variable *pnToken
    13096
    **   to the total number of tokens in the current row. Or, if iCol is
    13097
    **   non-negative but less than the number of columns in the table, set
    13098
    **   *pnToken to the number of tokens in column iCol of the current row.
    13099
    **
    13100
    **   If parameter iCol is greater than or equal to the number of columns
    13101
    **   in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
    13102
    **   an OOM condition or IO error), an appropriate SQLite error code is
    13103
    **   returned.
    13104
    **
    13105
    **   This function may be quite inefficient if used with an FTS5 table
    13106
    **   created with the "columnsize=0" option.
    13107
    **
    13108
    ** xColumnText:
    13109
    **   If parameter iCol is less than zero, or greater than or equal to the
    13110
    **   number of columns in the table, SQLITE_RANGE is returned.
    13111
    **
    13112
    **   Otherwise, this function attempts to retrieve the text of column iCol of
    13113
    **   the current document. If successful, (*pz) is set to point to a buffer
    13114
    **   containing the text in utf-8 encoding, (*pn) is set to the size in bytes
    13115
    **   (not characters) of the buffer and SQLITE_OK is returned. Otherwise,
    13116
    **   if an error occurs, an SQLite error code is returned and the final values
    13117
    **   of (*pz) and (*pn) are undefined.
    13118
    **
    13119
    ** xPhraseCount:
    13120
    **   Returns the number of phrases in the current query expression.
    13121
    **
    13122
    ** xPhraseSize:
    13123
    **   If parameter iCol is less than zero, or greater than or equal to the
    13124
    **   number of phrases in the current query, as returned by xPhraseCount,
    13125
    **   0 is returned. Otherwise, this function returns the number of tokens in
    13126
    **   phrase iPhrase of the query. Phrases are numbered starting from zero.
    13127
    **
    13128
    ** xInstCount:
    13129
    **   Set *pnInst to the total number of occurrences of all phrases within
    13130
    **   the query within the current row. Return SQLITE_OK if successful, or
    13131
    **   an error code (i.e. SQLITE_NOMEM) if an error occurs.
    13132
    **
    13133
    **   This API can be quite slow if used with an FTS5 table created with the
    13134
    **   "detail=none" or "detail=column" option. If the FTS5 table is created
    13135
    **   with either "detail=none" or "detail=column" and "content=" option
    13136
    **   (i.e. if it is a contentless table), then this API always returns 0.
    13137
    **
    13138
    ** xInst:
    13139
    **   Query for the details of phrase match iIdx within the current row.
    13140
    **   Phrase matches are numbered starting from zero, so the iIdx argument
    13141
    **   should be greater than or equal to zero and smaller than the value
    13142
    **   output by xInstCount(). If iIdx is less than zero or greater than
    13143
    **   or equal to the value returned by xInstCount(), SQLITE_RANGE is returned.
    13144
    **
    13145
    **   Otherwise, output parameter *piPhrase is set to the phrase number, *piCol
    13146
    **   to the column in which it occurs and *piOff the token offset of the
    13147
    **   first token of the phrase. SQLITE_OK is returned if successful, or an
    13148
    **   error code (i.e. SQLITE_NOMEM) if an error occurs.
    13149
    **
    13150
    **   This API can be quite slow if used with an FTS5 table created with the
    13151
    **   "detail=none" or "detail=column" option.
    13152
    **
    13153
    ** xRowid:
    13154
    **   Returns the rowid of the current row.
    13155
    **
    13156
    ** xTokenize:
    13157
    **   Tokenize text using the tokenizer belonging to the FTS5 table.
    13158
    **
    13159
    ** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback):
    13160
    **   This API function is used to query the FTS table for phrase iPhrase
    13161
    **   of the current query. Specifically, a query equivalent to:
    13162
    **
    13163
    **       ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid
    13164
    **
    13165
    **   with $p set to a phrase equivalent to the phrase iPhrase of the
    13166
    **   current query is executed. Any column filter that applies to
    13167
    **   phrase iPhrase of the current query is included in $p. For each
    13168
    **   row visited, the callback function passed as the fourth argument
    13169
    **   is invoked. The context and API objects passed to the callback
    13170
    **   function may be used to access the properties of each matched row.
    13171
    **   Invoking Api.xUserData() returns a copy of the pointer passed as
    13172
    **   the third argument to pUserData.
    13173
    **
    13174
    **   If parameter iPhrase is less than zero, or greater than or equal to
    13175
    **   the number of phrases in the query, as returned by xPhraseCount(),
    13176
    **   this function returns SQLITE_RANGE.
    13177
    **
    13178
    **   If the callback function returns any value other than SQLITE_OK, the
    13179
    **   query is abandoned and the xQueryPhrase function returns immediately.
    13180
    **   If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK.
    13181
    **   Otherwise, the error code is propagated upwards.
    13182
    **
    13183
    **   If the query runs to completion without incident, SQLITE_OK is returned.
    13184
    **   Or, if some error occurs before the query completes or is aborted by
    13185
    **   the callback, an SQLite error code is returned.
    13186
    **
    13187
    **
    13188
    ** xSetAuxdata(pFts5, pAux, xDelete)
    13189
    **
    13190
    **   Save the pointer passed as the second argument as the extension function's
    13191
    **   "auxiliary data". The pointer may then be retrieved by the current or any
    13192
    **   future invocation of the same fts5 extension function made as part of
    13193
    **   the same MATCH query using the xGetAuxdata() API.
    13194
    **
    13195
    **   Each extension function is allocated a single auxiliary data slot for
    13196
    **   each FTS query (MATCH expression). If the extension function is invoked
    13197
    **   more than once for a single FTS query, then all invocations share a
    13198
    **   single auxiliary data context.
    13199
    **
    13200
    **   If there is already an auxiliary data pointer when this function is
    13201
    **   invoked, then it is replaced by the new pointer. If an xDelete callback
    13202
    **   was specified along with the original pointer, it is invoked at this
    13203
    **   point.
    13204
    **
    13205
    **   The xDelete callback, if one is specified, is also invoked on the
    13206
    **   auxiliary data pointer after the FTS5 query has finished.
    13207
    **
    13208
    **   If an error (e.g. an OOM condition) occurs within this function,
    13209
    **   the auxiliary data is set to NULL and an error code returned. If the
    13210
    **   xDelete parameter was not NULL, it is invoked on the auxiliary data
    13211
    **   pointer before returning.
    13212
    **
    13213
    **
    13214
    ** xGetAuxdata(pFts5, bClear)
    13215
    **
    13216
    **   Returns the current auxiliary data pointer for the fts5 extension
    13217
    **   function. See the xSetAuxdata() method for details.
    13218
    **
    13219
    **   If the bClear argument is non-zero, then the auxiliary data is cleared
    13220
    **   (set to NULL) before this function returns. In this case the xDelete,
    13221
    **   if any, is not invoked.
    13222
    **
    13223
    **
    13224
    ** xRowCount(pFts5, pnRow)
    13225
    **
    13226
    **   This function is used to retrieve the total number of rows in the table.
    13227
    **   In other words, the same value that would be returned by:
    13228
    **
    13229
    **        SELECT count(*) FROM ftstable;
    13230
    **
    13231
    ** xPhraseFirst()
    13232
    **   This function is used, along with type Fts5PhraseIter and the xPhraseNext
    13233
    **   method, to iterate through all instances of a single query phrase within
    13234
    **   the current row. This is the same information as is accessible via the
    13235
    **   xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient
    13236
    **   to use, this API may be faster under some circumstances. To iterate
    13237
    **   through instances of phrase iPhrase, use the following code:
    13238
    **
    13239
    **       Fts5PhraseIter iter;
    13240
    **       int iCol, iOff;
    13241
    **       for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff);
    13242
    **           iCol>=0;
    13243
    **           pApi->xPhraseNext(pFts, &iter, &iCol, &iOff)
    13244
    **       ){
    13245
    **         // An instance of phrase iPhrase at offset iOff of column iCol
    13246
    **       }
    13247
    **
    13248
    **   The Fts5PhraseIter structure is defined above. Applications should not
    13249
    **   modify this structure directly - it should only be used as shown above
    13250
    **   with the xPhraseFirst() and xPhraseNext() API methods (and by
    13251
    **   xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below).
    13252
    **
    13253
    **   This API can be quite slow if used with an FTS5 table created with the
    13254
    **   "detail=none" or "detail=column" option. If the FTS5 table is created
    13255
    **   with either "detail=none" or "detail=column" and "content=" option
    13256
    **   (i.e. if it is a contentless table), then this API always iterates
    13257
    **   through an empty set (all calls to xPhraseFirst() set iCol to -1).
    13258
    **
    13259
    **   In all cases, matches are visited in (column ASC, offset ASC) order.
    13260
    **   i.e. all those in column 0, sorted by offset, followed by those in
    13261
    **   column 1, etc.
    13262
    **
    13263
    ** xPhraseNext()
    13264
    **   See xPhraseFirst above.
    13265
    **
    13266
    ** xPhraseFirstColumn()
    13267
    **   This function and xPhraseNextColumn() are similar to the xPhraseFirst()
    13268
    **   and xPhraseNext() APIs described above. The difference is that instead
    13269
    **   of iterating through all instances of a phrase in the current row, these
    13270
    **   APIs are used to iterate through the set of columns in the current row
    13271
    **   that contain one or more instances of a specified phrase. For example:
    13272
    **
    13273
    **       Fts5PhraseIter iter;
    13274
    **       int iCol;
    13275
    **       for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol);
    13276
    **           iCol>=0;
    13277
    **           pApi->xPhraseNextColumn(pFts, &iter, &iCol)
    13278
    **       ){
    13279
    **         // Column iCol contains at least one instance of phrase iPhrase
    13280
    **       }
    13281
    **
    13282
    **   This API can be quite slow if used with an FTS5 table created with the
    13283
    **   "detail=none" option. If the FTS5 table is created with either
    13284
    **   "detail=none" "content=" option (i.e. if it is a contentless table),
    13285
    **   then this API always iterates through an empty set (all calls to
    13286
    **   xPhraseFirstColumn() set iCol to -1).
    13287
    **
    13288
    **   The information accessed using this API and its companion
    13289
    **   xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext
    13290
    **   (or xInst/xInstCount). The chief advantage of this API is that it is
    13291
    **   significantly more efficient than those alternatives when used with
    13292
    **   "detail=column" tables.
    13293
    **
    13294
    ** xPhraseNextColumn()
    13295
    **   See xPhraseFirstColumn above.
    13296
    **
    13297
    ** xQueryToken(pFts5, iPhrase, iToken, ppToken, pnToken)
    13298
    **   This is used to access token iToken of phrase iPhrase of the current
    13299
    **   query. Before returning, output parameter *ppToken is set to point
    13300
    **   to a buffer containing the requested token, and *pnToken to the
    13301
    **   size of this buffer in bytes.
    13302
    **
    13303
    **   If iPhrase or iToken are less than zero, or if iPhrase is greater than
    13304
    **   or equal to the number of phrases in the query as reported by
    13305
    **   xPhraseCount(), or if iToken is equal to or greater than the number of
    13306
    **   tokens in the phrase, SQLITE_RANGE is returned and *ppToken and *pnToken
    13307
         are both zeroed.
    13308
    **
    13309
    **   The output text is not a copy of the query text that specified the
    13310
    **   token. It is the output of the tokenizer module. For tokendata=1
    13311
    **   tables, this includes any embedded 0x00 and trailing data.
    13312
    **
    13313
    ** xInstToken(pFts5, iIdx, iToken, ppToken, pnToken)
    13314
    **   This is used to access token iToken of phrase hit iIdx within the
    13315
    **   current row. If iIdx is less than zero or greater than or equal to the
    13316
    **   value returned by xInstCount(), SQLITE_RANGE is returned.  Otherwise,
    13317
    **   output variable (*ppToken) is set to point to a buffer containing the
    13318
    **   matching document token, and (*pnToken) to the size of that buffer in
    13319
    **   bytes.
    13320
    **
    13321
    **   The output text is not a copy of the document text that was tokenized.
    13322
    **   It is the output of the tokenizer module. For tokendata=1 tables, this
    13323
    **   includes any embedded 0x00 and trailing data.
    13324
    **
    13325
    **   This API may be slow in some cases if the token identified by parameters
    13326
    **   iIdx and iToken matched a prefix token in the query. In most cases, the
    13327
    **   first call to this API for each prefix token in the query is forced
    13328
    **   to scan the portion of the full-text index that matches the prefix
    13329
    **   token to collect the extra data required by this API. If the prefix
    13330
    **   token matches a large number of token instances in the document set,
    13331
    **   this may be a performance problem.
    13332
    **
    13333
    **   If the user knows in advance that a query may use this API for a
    13334
    **   prefix token, FTS5 may be configured to collect all required data as part
    13335
    **   of the initial querying of the full-text index, avoiding the second scan
    13336
    **   entirely. This also causes prefix queries that do not use this API to
    13337
    **   run more slowly and use more memory. FTS5 may be configured in this way
    13338
    **   either on a per-table basis using the [FTS5 insttoken | 'insttoken']
    13339
    **   option, or on a per-query basis using the
    13340
    **   [fts5_insttoken | fts5_insttoken()] user function.
    13341
    **
    13342
    **   This API can be quite slow if used with an FTS5 table created with the
    13343
    **   "detail=none" or "detail=column" option.
    13344
    **
    13345
    ** xColumnLocale(pFts5, iIdx, pzLocale, pnLocale)
    13346
    **   If parameter iCol is less than zero, or greater than or equal to the
    13347
    **   number of columns in the table, SQLITE_RANGE is returned.
    13348
    **
    13349
    **   Otherwise, this function attempts to retrieve the locale associated
    13350
    **   with column iCol of the current row. Usually, there is no associated
    13351
    **   locale, and output parameters (*pzLocale) and (*pnLocale) are set
    13352
    **   to NULL and 0, respectively. However, if the fts5_locale() function
    13353
    **   was used to associate a locale with the value when it was inserted
    13354
    **   into the fts5 table, then (*pzLocale) is set to point to a nul-terminated
    13355
    **   buffer containing the name of the locale in utf-8 encoding. (*pnLocale)
    13356
    **   is set to the size in bytes of the buffer, not including the
    13357
    **   nul-terminator.
    13358
    **
    13359
    **   If successful, SQLITE_OK is returned. Or, if an error occurs, an
    13360
    **   SQLite error code is returned. The final value of the output parameters
    13361
    **   is undefined in this case.
    13362
    **
    13363
    ** xTokenize_v2:
    13364
    **   Tokenize text using the tokenizer belonging to the FTS5 table. This
    13365
    **   API is the same as the xTokenize() API, except that it allows a tokenizer
    13366
    **   locale to be specified.
    13367
    */
    13368
    struct Fts5ExtensionApi {
    13369
      int iVersion;                   /* Currently always set to 4 */
    13370
    13371
      void *(*xUserData)(Fts5Context*);
    13372
    13373
      int (*xColumnCount)(Fts5Context*);
    13374
      int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow);
    13375
      int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken);
    13376
    13377
      int (*xTokenize)(Fts5Context*,
    13378
        const char *pText, int nText, /* Text to tokenize */
    13379
        void *pCtx,                   /* Context passed to xToken() */
    13380
        int (*xToken)(void*, int, const char*, int, int, int)       /* Callback */
    13381
      );
    13382
    13383
      int (*xPhraseCount)(Fts5Context*);
    13384
      int (*xPhraseSize)(Fts5Context*, int iPhrase);
    13385
    13386
      int (*xInstCount)(Fts5Context*, int *pnInst);
    13387
      int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff);
    13388
    13389
      sqlite3_int64 (*xRowid)(Fts5Context*);
    13390
      int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn);
    13391
      int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken);
    13392
    13393
      int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData,
    13394
        int(*)(const Fts5ExtensionApi*,Fts5Context*,void*)
    13395
      );
    13396
      int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*));
    13397
      void *(*xGetAuxdata)(Fts5Context*, int bClear);
    13398
    13399
      int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*);
    13400
      void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff);
    13401
    13402
      int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*);
    13403
      void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol);
    13404
    13405
      /* Below this point are iVersion>=3 only */
    13406
      int (*xQueryToken)(Fts5Context*,
    13407
          int iPhrase, int iToken,
    13408
          const char **ppToken, int *pnToken
    13409
      );
    13410
      int (*xInstToken)(Fts5Context*, int iIdx, int iToken, const char**, int*);
    13411
    13412
      /* Below this point are iVersion>=4 only */
    13413
      int (*xColumnLocale)(Fts5Context*, int iCol, const char **pz, int *pn);
    13414
      int (*xTokenize_v2)(Fts5Context*,
    13415
        const char *pText, int nText,      /* Text to tokenize */
    13416
        const char *pLocale, int nLocale,  /* Locale to pass to tokenizer */
    13417
        void *pCtx,                        /* Context passed to xToken() */
    13418
        int (*xToken)(void*, int, const char*, int, int, int)       /* Callback */
    13419
      );
    13420
    };
    13421
    13422
    /*
    13423
    ** CUSTOM AUXILIARY FUNCTIONS
    13424
    *************************************************************************/
    13425
    13426
    /*************************************************************************
    13427
    ** CUSTOM TOKENIZERS
    13428
    **
    13429
    ** Applications may also register custom tokenizer types. A tokenizer
    13430
    ** is registered by providing fts5 with a populated instance of the
    13431
    ** following structure. All structure methods must be defined, setting
    13432
    ** any member of the fts5_tokenizer struct to NULL leads to undefined
    13433
    ** behaviour. The structure methods are expected to function as follows:
    13434
    **
    13435
    ** xCreate:
    13436
    **   This function is used to allocate and initialize a tokenizer instance.
    13437
    **   A tokenizer instance is required to actually tokenize text.
    13438
    **
    13439
    **   The first argument passed to this function is a copy of the (void*)
    13440
    **   pointer provided by the application when the fts5_tokenizer_v2 object
    13441
    **   was registered with FTS5 (the third argument to xCreateTokenizer()).
    13442
    **   The second and third arguments are an array of nul-terminated strings
    13443
    **   containing the tokenizer arguments, if any, specified following the
    13444
    **   tokenizer name as part of the CREATE VIRTUAL TABLE statement used
    13445
    **   to create the FTS5 table.
    13446
    **
    13447
    **   The final argument is an output variable. If successful, (*ppOut)
    13448
    **   should be set to point to the new tokenizer handle and SQLITE_OK
    13449
    **   returned. If an error occurs, some value other than SQLITE_OK should
    13450
    **   be returned. In this case, fts5 assumes that the final value of *ppOut
    13451
    **   is undefined.
    13452
    **
    13453
    ** xDelete:
    13454
    **   This function is invoked to delete a tokenizer handle previously
    13455
    **   allocated using xCreate(). Fts5 guarantees that this function will
    13456
    **   be invoked exactly once for each successful call to xCreate().
    13457
    **
    13458
    ** xTokenize:
    13459
    **   This function is expected to tokenize the nText byte string indicated
    13460
    **   by argument pText. pText may or may not be nul-terminated. The first
    13461
    **   argument passed to this function is a pointer to an Fts5Tokenizer object
    13462
    **   returned by an earlier call to xCreate().
    13463
    **
    13464
    **   The third argument indicates the reason that FTS5 is requesting
    13465
    **   tokenization of the supplied text. This is always one of the following
    13466
    **   four values:
    13467
    **
    13468
    **   <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into
    13469
    **            or removed from the FTS table. The tokenizer is being invoked to
    13470
    **            determine the set of tokens to add to (or delete from) the
    13471
    **            FTS index.
    13472
    **
    13473
    **       <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed
    13474
    **            against the FTS index. The tokenizer is being called to tokenize
    13475
    **            a bareword or quoted string specified as part of the query.
    13476
    **
    13477
    **       <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as
    13478
    **            FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is
    13479
    **            followed by a "*" character, indicating that the last token
    13480
    **            returned by the tokenizer will be treated as a token prefix.
    13481
    **
    13482
    **       <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to
    13483
    **            satisfy an fts5_api.xTokenize() request made by an auxiliary
    13484
    **            function. Or an fts5_api.xColumnSize() request made by the same
    13485
    **            on a columnsize=0 database.
    13486
    **   </ul>
    13487
    **
    13488
    **   The sixth and seventh arguments passed to xTokenize() - pLocale and
    13489
    **   nLocale - are a pointer to a buffer containing the locale to use for
    13490
    **   tokenization (e.g. "en_US") and its size in bytes, respectively. The
    13491
    **   pLocale buffer is not nul-terminated. pLocale may be passed NULL (in
    13492
    **   which case nLocale is always 0) to indicate that the tokenizer should
    13493
    **   use its default locale.
    13494
    **
    13495
    **   For each token in the input string, the supplied callback xToken() must
    13496
    **   be invoked. The first argument to it should be a copy of the pointer
    13497
    **   passed as the second argument to xTokenize(). The third and fourth
    13498
    **   arguments are a pointer to a buffer containing the token text, and the
    13499
    **   size of the token in bytes. The 4th and 5th arguments are the byte offsets
    13500
    **   of the first byte of and first byte immediately following the text from
    13501
    **   which the token is derived within the input.
    13502
    **
    13503
    **   The second argument passed to the xToken() callback ("tflags") should
    13504
    **   normally be set to 0. The exception is if the tokenizer supports
    13505
    **   synonyms. In this case see the discussion below for details.
    13506
    **
    13507
    **   FTS5 assumes the xToken() callback is invoked for each token in the
    13508
    **   order that they occur within the input text.
    13509
    **
    13510
    **   If an xToken() callback returns any value other than SQLITE_OK, then
    13511
    **   the tokenization should be abandoned and the xTokenize() method should
    13512
    **   immediately return a copy of the xToken() return value. Or, if the
    13513
    **   input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally,
    13514
    **   if an error occurs with the xTokenize() implementation itself, it
    13515
    **   may abandon the tokenization and return any error code other than
    13516
    **   SQLITE_OK or SQLITE_DONE.
    13517
    **
    13518
    **   If the tokenizer is registered using an fts5_tokenizer_v2 object,
    13519
    **   then the xTokenize() method has two additional arguments - pLocale
    13520
    **   and nLocale. These specify the locale that the tokenizer should use
    13521
    **   for the current request. If pLocale and nLocale are both 0, then the
    13522
    **   tokenizer should use its default locale. Otherwise, pLocale points to
    13523
    **   an nLocale byte buffer containing the name of the locale to use as utf-8
    13524
    **   text. pLocale is not nul-terminated.
    13525
    **
    13526
    ** FTS5_TOKENIZER
    13527
    **
    13528
    ** There is also an fts5_tokenizer object. This is an older, deprecated,
    13529
    ** version of fts5_tokenizer_v2. It is similar except that:
    13530
    **
    13531
    **  <ul>
    13532
    **    <li> There is no "iVersion" field, and
    13533
    **    <li> The xTokenize() method does not take a locale argument.
    13534
    **  </ul>
    13535
    **
    13536
    ** Legacy fts5_tokenizer tokenizers must be registered using the
    13537
    ** legacy xCreateTokenizer() function, instead of xCreateTokenizer_v2().
    13538
    **
    13539
    ** Tokenizer implementations registered using either API may be retrieved
    13540
    ** using both xFindTokenizer() and xFindTokenizer_v2().
    13541
    **
    13542
    ** SYNONYM SUPPORT
    13543
    **
    13544
    **   Custom tokenizers may also support synonyms. Consider a case in which a
    13545
    **   user wishes to query for a phrase such as "first place". Using the
    13546
    **   built-in tokenizers, the FTS5 query 'first + place' will match instances
    13547
    **   of "first place" within the document set, but not alternative forms
    13548
    **   such as "1st place". In some applications, it would be better to match
    13549
    **   all instances of "first place" or "1st place" regardless of which form
    13550
    **   the user specified in the MATCH query text.
    13551
    **
    13552
    **   There are several ways to approach this in FTS5:
    13553
    **
    13554
    **   <ol><li> By mapping all synonyms to a single token. In this case, using
    13555
    **            the above example, this means that the tokenizer returns the
    13556
    **            same token for inputs "first" and "1st". Say that token is in
    13557
    **            fact "first", so that when the user inserts the document "I won
    13558
    **            1st place" entries are added to the index for tokens "i", "won",
    13559
    **            "first" and "place". If the user then queries for '1st + place',
    13560
    **            the tokenizer substitutes "first" for "1st" and the query works
    13561
    **            as expected.
    13562
    **
    13563
    **       <li> By querying the index for all synonyms of each query term
    13564
    **            separately. In this case, when tokenizing query text, the
    13565
    **            tokenizer may provide multiple synonyms for a single term
    13566
    **            within the document. FTS5 then queries the index for each
    13567
    **            synonym individually. For example, faced with the query:
    13568
    **
    13569
    **   <codeblock>
    13570
    **     ... MATCH 'first place'</codeblock>
    13571
    **
    13572
    **            the tokenizer offers both "1st" and "first" as synonyms for the
    13573
    **            first token in the MATCH query and FTS5 effectively runs a query
    13574
    **            similar to:
    13575
    **
    13576
    **   <codeblock>
    13577
    **     ... MATCH '(first OR 1st) place'</codeblock>
    13578
    **
    13579
    **            except that, for the purposes of auxiliary functions, the query
    13580
    **            still appears to contain just two phrases - "(first OR 1st)"
    13581
    **            being treated as a single phrase.
    13582
    **
    13583
    **       <li> By adding multiple synonyms for a single term to the FTS index.
    13584
    **            Using this method, when tokenizing document text, the tokenizer
    13585
    **            provides multiple synonyms for each token. So that when a
    13586
    **            document such as "I won first place" is tokenized, entries are
    13587
    **            added to the FTS index for "i", "won", "first", "1st" and
    13588
    **            "place".
    13589
    **
    13590
    **            This way, even if the tokenizer does not provide synonyms
    13591
    **            when tokenizing query text (it should not - to do so would be
    13592
    **            inefficient), it doesn't matter if the user queries for
    13593
    **            'first + place' or '1st + place', as there are entries in the
    13594
    **            FTS index corresponding to both forms of the first token.
    13595
    **   </ol>
    13596
    **
    13597
    **   Whether it is parsing document or query text, any call to xToken that
    13598
    **   specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit
    13599
    **   is considered to supply a synonym for the previous token. For example,
    13600
    **   when parsing the document "I won first place", a tokenizer that supports
    13601
    **   synonyms would call xToken() 5 times, as follows:
    13602
    **
    13603
    **   <codeblock>
    13604
    **       xToken(pCtx, 0, "i",                      1,  0,  1);
    13605
    **       xToken(pCtx, 0, "won",                    3,  2,  5);
    13606
    **       xToken(pCtx, 0, "first",                  5,  6, 11);
    13607
    **       xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3,  6, 11);
    13608
    **       xToken(pCtx, 0, "place",                  5, 12, 17);
    13609
    **</codeblock>
    13610
    **
    13611
    **   It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time
    13612
    **   xToken() is called. Multiple synonyms may be specified for a single token
    13613
    **   by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence.
    13614
    **   There is no limit to the number of synonyms that may be provided for a
    13615
    **   single token.
    13616
    **
    13617
    **   In many cases, method (1) above is the best approach. It does not add
    13618
    **   extra data to the FTS index or require FTS5 to query for multiple terms,
    13619
    **   so it is efficient in terms of disk space and query speed. However, it
    13620
    **   does not support prefix queries very well. If, as suggested above, the
    13621
    **   token "first" is substituted for "1st" by the tokenizer, then the query:
    13622
    **
    13623
    **   <codeblock>
    13624
    **     ... MATCH '1s*'</codeblock>
    13625
    **
    13626
    **   will not match documents that contain the token "1st" (as the tokenizer
    13627
    **   will probably not map "1s" to any prefix of "first").
    13628
    **
    13629
    **   For full prefix support, method (3) may be preferred. In this case,
    13630
    **   because the index contains entries for both "first" and "1st", prefix
    13631
    **   queries such as 'fi*' or '1s*' will match correctly. However, because
    13632
    **   extra entries are added to the FTS index, this method uses more space
    13633
    **   within the database.
    13634
    **
    13635
    **   Method (2) offers a midpoint between (1) and (3). Using this method,
    13636
    **   a query such as '1s*' will match documents that contain the literal
    13637
    **   token "1st", but not "first" (assuming the tokenizer is not able to
    13638
    **   provide synonyms for prefixes). However, a non-prefix query like '1st'
    13639
    **   will match against "1st" and "first". This method does not require
    13640
    **   extra disk space, as no extra entries are added to the FTS index.
    13641
    **   On the other hand, it may require more CPU cycles to run MATCH queries,
    13642
    **   as separate queries of the FTS index are required for each synonym.
    13643
    **
    13644
    **   When using methods (2) or (3), it is important that the tokenizer only
    13645
    **   provide synonyms when tokenizing document text (method (3)) or query
    13646
    **   text (method (2)), not both. Doing so will not cause any errors, but is
    13647
    **   inefficient.
    13648
    */
    13649
    typedef struct Fts5Tokenizer Fts5Tokenizer;
    13650
    typedef struct fts5_tokenizer_v2 fts5_tokenizer_v2;
    13651
    struct fts5_tokenizer_v2 {
    13652
      int iVersion;             /* Currently always 2 */
    13653
    13654
      int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
    13655
      void (*xDelete)(Fts5Tokenizer*);
    13656
      int (*xTokenize)(Fts5Tokenizer*,
    13657
          void *pCtx,
    13658
          int flags,            /* Mask of FTS5_TOKENIZE_* flags */
    13659
          const char *pText, int nText,
    13660
          const char *pLocale, int nLocale,
    13661
          int (*xToken)(
    13662
            void *pCtx,         /* Copy of 2nd argument to xTokenize() */
    13663
            int tflags,         /* Mask of FTS5_TOKEN_* flags */
    13664
            const char *pToken, /* Pointer to buffer containing token */
    13665
            int nToken,         /* Size of token in bytes */
    13666
            int iStart,         /* Byte offset of token within input text */
    13667
            int iEnd            /* Byte offset of end of token within input text */
    13668
          )
    13669
      );
    13670
    };
    13671
    13672
    /*
    13673
    ** New code should use the fts5_tokenizer_v2 type to define tokenizer
    13674
    ** implementations. The following type is included for legacy applications
    13675
    ** that still use it.
    13676
    */
    13677
    typedef struct fts5_tokenizer fts5_tokenizer;
    13678
    struct fts5_tokenizer {
    13679
      int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
    13680
      void (*xDelete)(Fts5Tokenizer*);
    13681
      int (*xTokenize)(Fts5Tokenizer*,
    13682
          void *pCtx,
    13683
          int flags,            /* Mask of FTS5_TOKENIZE_* flags */
    13684
          const char *pText, int nText,
    13685
          int (*xToken)(
    13686
            void *pCtx,         /* Copy of 2nd argument to xTokenize() */
    13687
            int tflags,         /* Mask of FTS5_TOKEN_* flags */
    13688
            const char *pToken, /* Pointer to buffer containing token */
    13689
            int nToken,         /* Size of token in bytes */
    13690
            int iStart,         /* Byte offset of token within input text */
    13691
            int iEnd            /* Byte offset of end of token within input text */
    13692
          )
    13693
      );
    13694
    };
    13695
    13696
    13697
    /* Flags that may be passed as the third argument to xTokenize() */
    13698
    #define FTS5_TOKENIZE_QUERY     0x0001
    13699
    #define FTS5_TOKENIZE_PREFIX    0x0002
    13700
    #define FTS5_TOKENIZE_DOCUMENT  0x0004
    13701
    #define FTS5_TOKENIZE_AUX       0x0008
    13702
    13703
    /* Flags that may be passed by the tokenizer implementation back to FTS5
    13704
    ** as the third argument to the supplied xToken callback. */
    13705
    #define FTS5_TOKEN_COLOCATED    0x0001      /* Same position as prev. token */
    13706
    13707
    /*
    13708
    ** END OF CUSTOM TOKENIZERS
    13709
    *************************************************************************/
    13710
    13711
    /*************************************************************************
    13712
    ** FTS5 EXTENSION REGISTRATION API
    13713
    */
    13714
    typedef struct fts5_api fts5_api;
    13715
    struct fts5_api {
    13716
      int iVersion;                   /* Currently always set to 3 */
    13717
    13718
      /* Create a new tokenizer */
    13719
      int (*xCreateTokenizer)(
    13720
        fts5_api *pApi,
    13721
        const char *zName,
    13722
        void *pUserData,
    13723
        fts5_tokenizer *pTokenizer,
    13724
        void (*xDestroy)(void*)
    13725
      );
    13726
    13727
      /* Find an existing tokenizer */
    13728
      int (*xFindTokenizer)(
    13729
        fts5_api *pApi,
    13730
        const char *zName,
    13731
        void **ppUserData,
    13732
        fts5_tokenizer *pTokenizer
    13733
      );
    13734
    13735
      /* Create a new auxiliary function */
    13736
      int (*xCreateFunction)(
    13737
        fts5_api *pApi,
    13738
        const char *zName,
    13739
        void *pUserData,
    13740
        fts5_extension_function xFunction,
    13741
        void (*xDestroy)(void*)
    13742
      );
    13743
    13744
      /* APIs below this point are only available if iVersion>=3 */
    13745
    13746
      /* Create a new tokenizer */
    13747
      int (*xCreateTokenizer_v2)(
    13748
        fts5_api *pApi,
    13749
        const char *zName,
    13750
        void *pUserData,
    13751
        fts5_tokenizer_v2 *pTokenizer,
    13752
        void (*xDestroy)(void*)
    13753
      );
    13754
    13755
      /* Find an existing tokenizer */
    13756
      int (*xFindTokenizer_v2)(
    13757
        fts5_api *pApi,
    13758
        const char *zName,
    13759
        void **ppUserData,
    13760
        fts5_tokenizer_v2 **ppTokenizer
    13761
      );
    13762
    };
    13763
    13764
    /*
    13765
    ** END OF REGISTRATION API
    13766
    *************************************************************************/
    13767
    13768
    #ifdef __cplusplus
    13769
    }  /* end of the 'extern "C"' block */
    13770
    #endif
    13771
    13772
    #endif /* _FTS5_H */
    13773
    13774
    /******** End of fts5.h *********/
    13775
    #endif /* SQLITE3_H */