Annotation of embedaddon/php/ext/sqlite3/libsqlite/sqlite3.h, revision 1.1

1.1     ! misho       1: /*
        !             2: ** 2001 September 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
        !            26: ** on how SQLite interfaces are suppose 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: ** Add the ability to override 'extern'
        !            47: */
        !            48: #ifndef SQLITE_EXTERN
        !            49: # define SQLITE_EXTERN extern
        !            50: #endif
        !            51: 
        !            52: #ifndef SQLITE_API
        !            53: # define SQLITE_API
        !            54: #endif
        !            55: 
        !            56: 
        !            57: /*
        !            58: ** These no-op macros are used in front of interfaces to mark those
        !            59: ** interfaces as either deprecated or experimental.  New applications
        !            60: ** should not use deprecated interfaces - they are support for backwards
        !            61: ** compatibility only.  Application writers should be aware that
        !            62: ** experimental interfaces are subject to change in point releases.
        !            63: **
        !            64: ** These macros used to resolve to various kinds of compiler magic that
        !            65: ** would generate warning messages when they were used.  But that
        !            66: ** compiler magic ended up generating such a flurry of bug reports
        !            67: ** that we have taken it all out and gone back to using simple
        !            68: ** noop macros.
        !            69: */
        !            70: #define SQLITE_DEPRECATED
        !            71: #define SQLITE_EXPERIMENTAL
        !            72: 
        !            73: /*
        !            74: ** Ensure these symbols were not defined by some previous header file.
        !            75: */
        !            76: #ifdef SQLITE_VERSION
        !            77: # undef SQLITE_VERSION
        !            78: #endif
        !            79: #ifdef SQLITE_VERSION_NUMBER
        !            80: # undef SQLITE_VERSION_NUMBER
        !            81: #endif
        !            82: 
        !            83: /*
        !            84: ** CAPI3REF: Compile-Time Library Version Numbers
        !            85: **
        !            86: ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header
        !            87: ** evaluates to a string literal that is the SQLite version in the
        !            88: ** format "X.Y.Z" where X is the major version number (always 3 for
        !            89: ** SQLite3) and Y is the minor version number and Z is the release number.)^
        !            90: ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer
        !            91: ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same
        !            92: ** numbers used in [SQLITE_VERSION].)^
        !            93: ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also
        !            94: ** be larger than the release from which it is derived.  Either Y will
        !            95: ** be held constant and Z will be incremented or else Y will be incremented
        !            96: ** and Z will be reset to zero.
        !            97: **
        !            98: ** Since version 3.6.18, SQLite source code has been stored in the
        !            99: ** <a href="http://www.fossil-scm.org/">Fossil configuration management
        !           100: ** system</a>.  ^The SQLITE_SOURCE_ID macro evaluates to
        !           101: ** a string which identifies a particular check-in of SQLite
        !           102: ** within its configuration management system.  ^The SQLITE_SOURCE_ID
        !           103: ** string contains the date and time of the check-in (UTC) and an SHA1
        !           104: ** hash of the entire source tree.
        !           105: **
        !           106: ** See also: [sqlite3_libversion()],
        !           107: ** [sqlite3_libversion_number()], [sqlite3_sourceid()],
        !           108: ** [sqlite_version()] and [sqlite_source_id()].
        !           109: */
        !           110: #define SQLITE_VERSION        "3.7.7.1"
        !           111: #define SQLITE_VERSION_NUMBER 3007007
        !           112: #define SQLITE_SOURCE_ID      "2011-06-28 17:39:05 af0d91adf497f5f36ec3813f04235a6e195a605f"
        !           113: 
        !           114: /*
        !           115: ** CAPI3REF: Run-Time Library Version Numbers
        !           116: ** KEYWORDS: sqlite3_version, sqlite3_sourceid
        !           117: **
        !           118: ** These interfaces provide the same information as the [SQLITE_VERSION],
        !           119: ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
        !           120: ** but are associated with the library instead of the header file.  ^(Cautious
        !           121: ** programmers might include assert() statements in their application to
        !           122: ** verify that values returned by these interfaces match the macros in
        !           123: ** the header, and thus insure that the application is
        !           124: ** compiled with matching library and header files.
        !           125: **
        !           126: ** <blockquote><pre>
        !           127: ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
        !           128: ** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 );
        !           129: ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
        !           130: ** </pre></blockquote>)^
        !           131: **
        !           132: ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION]
        !           133: ** macro.  ^The sqlite3_libversion() function returns a pointer to the
        !           134: ** to the sqlite3_version[] string constant.  The sqlite3_libversion()
        !           135: ** function is provided for use in DLLs since DLL users usually do not have
        !           136: ** direct access to string constants within the DLL.  ^The
        !           137: ** sqlite3_libversion_number() function returns an integer equal to
        !           138: ** [SQLITE_VERSION_NUMBER].  ^The sqlite3_sourceid() function returns 
        !           139: ** a pointer to a string constant whose value is the same as the 
        !           140: ** [SQLITE_SOURCE_ID] C preprocessor macro.
        !           141: **
        !           142: ** See also: [sqlite_version()] and [sqlite_source_id()].
        !           143: */
        !           144: SQLITE_API SQLITE_EXTERN const char sqlite3_version[];
        !           145: SQLITE_API const char *sqlite3_libversion(void);
        !           146: SQLITE_API const char *sqlite3_sourceid(void);
        !           147: SQLITE_API int sqlite3_libversion_number(void);
        !           148: 
        !           149: /*
        !           150: ** CAPI3REF: Run-Time Library Compilation Options Diagnostics
        !           151: **
        !           152: ** ^The sqlite3_compileoption_used() function returns 0 or 1 
        !           153: ** indicating whether the specified option was defined at 
        !           154: ** compile time.  ^The SQLITE_ prefix may be omitted from the 
        !           155: ** option name passed to sqlite3_compileoption_used().  
        !           156: **
        !           157: ** ^The sqlite3_compileoption_get() function allows iterating
        !           158: ** over the list of options that were defined at compile time by
        !           159: ** returning the N-th compile time option string.  ^If N is out of range,
        !           160: ** sqlite3_compileoption_get() returns a NULL pointer.  ^The SQLITE_ 
        !           161: ** prefix is omitted from any strings returned by 
        !           162: ** sqlite3_compileoption_get().
        !           163: **
        !           164: ** ^Support for the diagnostic functions sqlite3_compileoption_used()
        !           165: ** and sqlite3_compileoption_get() may be omitted by specifying the 
        !           166: ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time.
        !           167: **
        !           168: ** See also: SQL functions [sqlite_compileoption_used()] and
        !           169: ** [sqlite_compileoption_get()] and the [compile_options pragma].
        !           170: */
        !           171: #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
        !           172: SQLITE_API int sqlite3_compileoption_used(const char *zOptName);
        !           173: SQLITE_API const char *sqlite3_compileoption_get(int N);
        !           174: #endif
        !           175: 
        !           176: /*
        !           177: ** CAPI3REF: Test To See If The Library Is Threadsafe
        !           178: **
        !           179: ** ^The sqlite3_threadsafe() function returns zero if and only if
        !           180: ** SQLite was compiled mutexing code omitted due to the
        !           181: ** [SQLITE_THREADSAFE] compile-time option being set to 0.
        !           182: **
        !           183: ** SQLite can be compiled with or without mutexes.  When
        !           184: ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes
        !           185: ** are enabled and SQLite is threadsafe.  When the
        !           186: ** [SQLITE_THREADSAFE] macro is 0, 
        !           187: ** the mutexes are omitted.  Without the mutexes, it is not safe
        !           188: ** to use SQLite concurrently from more than one thread.
        !           189: **
        !           190: ** Enabling mutexes incurs a measurable performance penalty.
        !           191: ** So if speed is of utmost importance, it makes sense to disable
        !           192: ** the mutexes.  But for maximum safety, mutexes should be enabled.
        !           193: ** ^The default behavior is for mutexes to be enabled.
        !           194: **
        !           195: ** This interface can be used by an application to make sure that the
        !           196: ** version of SQLite that it is linking against was compiled with
        !           197: ** the desired setting of the [SQLITE_THREADSAFE] macro.
        !           198: **
        !           199: ** This interface only reports on the compile-time mutex setting
        !           200: ** of the [SQLITE_THREADSAFE] flag.  If SQLite is compiled with
        !           201: ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but
        !           202: ** can be fully or partially disabled using a call to [sqlite3_config()]
        !           203: ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],
        !           204: ** or [SQLITE_CONFIG_MUTEX].  ^(The return value of the
        !           205: ** sqlite3_threadsafe() function shows only the compile-time setting of
        !           206: ** thread safety, not any run-time changes to that setting made by
        !           207: ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()
        !           208: ** is unchanged by calls to sqlite3_config().)^
        !           209: **
        !           210: ** See the [threading mode] documentation for additional information.
        !           211: */
        !           212: SQLITE_API int sqlite3_threadsafe(void);
        !           213: 
        !           214: /*
        !           215: ** CAPI3REF: Database Connection Handle
        !           216: ** KEYWORDS: {database connection} {database connections}
        !           217: **
        !           218: ** Each open SQLite database is represented by a pointer to an instance of
        !           219: ** the opaque structure named "sqlite3".  It is useful to think of an sqlite3
        !           220: ** pointer as an object.  The [sqlite3_open()], [sqlite3_open16()], and
        !           221: ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
        !           222: ** is its destructor.  There are many other interfaces (such as
        !           223: ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
        !           224: ** [sqlite3_busy_timeout()] to name but three) that are methods on an
        !           225: ** sqlite3 object.
        !           226: */
        !           227: typedef struct sqlite3 sqlite3;
        !           228: 
        !           229: /*
        !           230: ** CAPI3REF: 64-Bit Integer Types
        !           231: ** KEYWORDS: sqlite_int64 sqlite_uint64
        !           232: **
        !           233: ** Because there is no cross-platform way to specify 64-bit integer types
        !           234: ** SQLite includes typedefs for 64-bit signed and unsigned integers.
        !           235: **
        !           236: ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
        !           237: ** The sqlite_int64 and sqlite_uint64 types are supported for backwards
        !           238: ** compatibility only.
        !           239: **
        !           240: ** ^The sqlite3_int64 and sqlite_int64 types can store integer values
        !           241: ** between -9223372036854775808 and +9223372036854775807 inclusive.  ^The
        !           242: ** sqlite3_uint64 and sqlite_uint64 types can store integer values 
        !           243: ** between 0 and +18446744073709551615 inclusive.
        !           244: */
        !           245: #ifdef SQLITE_INT64_TYPE
        !           246:   typedef SQLITE_INT64_TYPE sqlite_int64;
        !           247:   typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
        !           248: #elif defined(_MSC_VER) || defined(__BORLANDC__)
        !           249:   typedef __int64 sqlite_int64;
        !           250:   typedef unsigned __int64 sqlite_uint64;
        !           251: #else
        !           252:   typedef long long int sqlite_int64;
        !           253:   typedef unsigned long long int sqlite_uint64;
        !           254: #endif
        !           255: typedef sqlite_int64 sqlite3_int64;
        !           256: typedef sqlite_uint64 sqlite3_uint64;
        !           257: 
        !           258: /*
        !           259: ** If compiling for a processor that lacks floating point support,
        !           260: ** substitute integer for floating-point.
        !           261: */
        !           262: #ifdef SQLITE_OMIT_FLOATING_POINT
        !           263: # define double sqlite3_int64
        !           264: #endif
        !           265: 
        !           266: /*
        !           267: ** CAPI3REF: Closing A Database Connection
        !           268: **
        !           269: ** ^The sqlite3_close() routine is the destructor for the [sqlite3] object.
        !           270: ** ^Calls to sqlite3_close() return SQLITE_OK if the [sqlite3] object is
        !           271: ** successfully destroyed and all associated resources are deallocated.
        !           272: **
        !           273: ** Applications must [sqlite3_finalize | finalize] all [prepared statements]
        !           274: ** and [sqlite3_blob_close | close] all [BLOB handles] associated with
        !           275: ** the [sqlite3] object prior to attempting to close the object.  ^If
        !           276: ** sqlite3_close() is called on a [database connection] that still has
        !           277: ** outstanding [prepared statements] or [BLOB handles], then it returns
        !           278: ** SQLITE_BUSY.
        !           279: **
        !           280: ** ^If [sqlite3_close()] is invoked while a transaction is open,
        !           281: ** the transaction is automatically rolled back.
        !           282: **
        !           283: ** The C parameter to [sqlite3_close(C)] must be either a NULL
        !           284: ** pointer or an [sqlite3] object pointer obtained
        !           285: ** from [sqlite3_open()], [sqlite3_open16()], or
        !           286: ** [sqlite3_open_v2()], and not previously closed.
        !           287: ** ^Calling sqlite3_close() with a NULL pointer argument is a 
        !           288: ** harmless no-op.
        !           289: */
        !           290: SQLITE_API int sqlite3_close(sqlite3 *);
        !           291: 
        !           292: /*
        !           293: ** The type for a callback function.
        !           294: ** This is legacy and deprecated.  It is included for historical
        !           295: ** compatibility and is not documented.
        !           296: */
        !           297: typedef int (*sqlite3_callback)(void*,int,char**, char**);
        !           298: 
        !           299: /*
        !           300: ** CAPI3REF: One-Step Query Execution Interface
        !           301: **
        !           302: ** The sqlite3_exec() interface is a convenience wrapper around
        !           303: ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
        !           304: ** that allows an application to run multiple statements of SQL
        !           305: ** without having to use a lot of C code. 
        !           306: **
        !           307: ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,
        !           308: ** semicolon-separate SQL statements passed into its 2nd argument,
        !           309: ** in the context of the [database connection] passed in as its 1st
        !           310: ** argument.  ^If the callback function of the 3rd argument to
        !           311: ** sqlite3_exec() is not NULL, then it is invoked for each result row
        !           312: ** coming out of the evaluated SQL statements.  ^The 4th argument to
        !           313: ** sqlite3_exec() is relayed through to the 1st argument of each
        !           314: ** callback invocation.  ^If the callback pointer to sqlite3_exec()
        !           315: ** is NULL, then no callback is ever invoked and result rows are
        !           316: ** ignored.
        !           317: **
        !           318: ** ^If an error occurs while evaluating the SQL statements passed into
        !           319: ** sqlite3_exec(), then execution of the current statement stops and
        !           320: ** subsequent statements are skipped.  ^If the 5th parameter to sqlite3_exec()
        !           321: ** is not NULL then any error message is written into memory obtained
        !           322: ** from [sqlite3_malloc()] and passed back through the 5th parameter.
        !           323: ** To avoid memory leaks, the application should invoke [sqlite3_free()]
        !           324: ** on error message strings returned through the 5th parameter of
        !           325: ** of sqlite3_exec() after the error message string is no longer needed.
        !           326: ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
        !           327: ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
        !           328: ** NULL before returning.
        !           329: **
        !           330: ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
        !           331: ** routine returns SQLITE_ABORT without invoking the callback again and
        !           332: ** without running any subsequent SQL statements.
        !           333: **
        !           334: ** ^The 2nd argument to the sqlite3_exec() callback function is the
        !           335: ** number of columns in the result.  ^The 3rd argument to the sqlite3_exec()
        !           336: ** callback is an array of pointers to strings obtained as if from
        !           337: ** [sqlite3_column_text()], one for each column.  ^If an element of a
        !           338: ** result row is NULL then the corresponding string pointer for the
        !           339: ** sqlite3_exec() callback is a NULL pointer.  ^The 4th argument to the
        !           340: ** sqlite3_exec() callback is an array of pointers to strings where each
        !           341: ** entry represents the name of corresponding result column as obtained
        !           342: ** from [sqlite3_column_name()].
        !           343: **
        !           344: ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer
        !           345: ** to an empty string, or a pointer that contains only whitespace and/or 
        !           346: ** SQL comments, then no SQL statements are evaluated and the database
        !           347: ** is not changed.
        !           348: **
        !           349: ** Restrictions:
        !           350: **
        !           351: ** <ul>
        !           352: ** <li> The application must insure that the 1st parameter to sqlite3_exec()
        !           353: **      is a valid and open [database connection].
        !           354: ** <li> The application must not close [database connection] specified by
        !           355: **      the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
        !           356: ** <li> The application must not modify the SQL statement text passed into
        !           357: **      the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
        !           358: ** </ul>
        !           359: */
        !           360: SQLITE_API int sqlite3_exec(
        !           361:   sqlite3*,                                  /* An open database */
        !           362:   const char *sql,                           /* SQL to be evaluated */
        !           363:   int (*callback)(void*,int,char**,char**),  /* Callback function */
        !           364:   void *,                                    /* 1st argument to callback */
        !           365:   char **errmsg                              /* Error msg written here */
        !           366: );
        !           367: 
        !           368: /*
        !           369: ** CAPI3REF: Result Codes
        !           370: ** KEYWORDS: SQLITE_OK {error code} {error codes}
        !           371: ** KEYWORDS: {result code} {result codes}
        !           372: **
        !           373: ** Many SQLite functions return an integer result code from the set shown
        !           374: ** here in order to indicates success or failure.
        !           375: **
        !           376: ** New error codes may be added in future versions of SQLite.
        !           377: **
        !           378: ** See also: [SQLITE_IOERR_READ | extended result codes],
        !           379: ** [sqlite3_vtab_on_conflict()] [SQLITE_ROLLBACK | result codes].
        !           380: */
        !           381: #define SQLITE_OK           0   /* Successful result */
        !           382: /* beginning-of-error-codes */
        !           383: #define SQLITE_ERROR        1   /* SQL error or missing database */
        !           384: #define SQLITE_INTERNAL     2   /* Internal logic error in SQLite */
        !           385: #define SQLITE_PERM         3   /* Access permission denied */
        !           386: #define SQLITE_ABORT        4   /* Callback routine requested an abort */
        !           387: #define SQLITE_BUSY         5   /* The database file is locked */
        !           388: #define SQLITE_LOCKED       6   /* A table in the database is locked */
        !           389: #define SQLITE_NOMEM        7   /* A malloc() failed */
        !           390: #define SQLITE_READONLY     8   /* Attempt to write a readonly database */
        !           391: #define SQLITE_INTERRUPT    9   /* Operation terminated by sqlite3_interrupt()*/
        !           392: #define SQLITE_IOERR       10   /* Some kind of disk I/O error occurred */
        !           393: #define SQLITE_CORRUPT     11   /* The database disk image is malformed */
        !           394: #define SQLITE_NOTFOUND    12   /* Unknown opcode in sqlite3_file_control() */
        !           395: #define SQLITE_FULL        13   /* Insertion failed because database is full */
        !           396: #define SQLITE_CANTOPEN    14   /* Unable to open the database file */
        !           397: #define SQLITE_PROTOCOL    15   /* Database lock protocol error */
        !           398: #define SQLITE_EMPTY       16   /* Database is empty */
        !           399: #define SQLITE_SCHEMA      17   /* The database schema changed */
        !           400: #define SQLITE_TOOBIG      18   /* String or BLOB exceeds size limit */
        !           401: #define SQLITE_CONSTRAINT  19   /* Abort due to constraint violation */
        !           402: #define SQLITE_MISMATCH    20   /* Data type mismatch */
        !           403: #define SQLITE_MISUSE      21   /* Library used incorrectly */
        !           404: #define SQLITE_NOLFS       22   /* Uses OS features not supported on host */
        !           405: #define SQLITE_AUTH        23   /* Authorization denied */
        !           406: #define SQLITE_FORMAT      24   /* Auxiliary database format error */
        !           407: #define SQLITE_RANGE       25   /* 2nd parameter to sqlite3_bind out of range */
        !           408: #define SQLITE_NOTADB      26   /* File opened that is not a database file */
        !           409: #define SQLITE_ROW         100  /* sqlite3_step() has another row ready */
        !           410: #define SQLITE_DONE        101  /* sqlite3_step() has finished executing */
        !           411: /* end-of-error-codes */
        !           412: 
        !           413: /*
        !           414: ** CAPI3REF: Extended Result Codes
        !           415: ** KEYWORDS: {extended error code} {extended error codes}
        !           416: ** KEYWORDS: {extended result code} {extended result codes}
        !           417: **
        !           418: ** In its default configuration, SQLite API routines return one of 26 integer
        !           419: ** [SQLITE_OK | result codes].  However, experience has shown that many of
        !           420: ** these result codes are too coarse-grained.  They do not provide as
        !           421: ** much information about problems as programmers might like.  In an effort to
        !           422: ** address this, newer versions of SQLite (version 3.3.8 and later) include
        !           423: ** support for additional result codes that provide more detailed information
        !           424: ** about errors. The extended result codes are enabled or disabled
        !           425: ** on a per database connection basis using the
        !           426: ** [sqlite3_extended_result_codes()] API.
        !           427: **
        !           428: ** Some of the available extended result codes are listed here.
        !           429: ** One may expect the number of extended result codes will be expand
        !           430: ** over time.  Software that uses extended result codes should expect
        !           431: ** to see new result codes in future releases of SQLite.
        !           432: **
        !           433: ** The SQLITE_OK result code will never be extended.  It will always
        !           434: ** be exactly zero.
        !           435: */
        !           436: #define SQLITE_IOERR_READ              (SQLITE_IOERR | (1<<8))
        !           437: #define SQLITE_IOERR_SHORT_READ        (SQLITE_IOERR | (2<<8))
        !           438: #define SQLITE_IOERR_WRITE             (SQLITE_IOERR | (3<<8))
        !           439: #define SQLITE_IOERR_FSYNC             (SQLITE_IOERR | (4<<8))
        !           440: #define SQLITE_IOERR_DIR_FSYNC         (SQLITE_IOERR | (5<<8))
        !           441: #define SQLITE_IOERR_TRUNCATE          (SQLITE_IOERR | (6<<8))
        !           442: #define SQLITE_IOERR_FSTAT             (SQLITE_IOERR | (7<<8))
        !           443: #define SQLITE_IOERR_UNLOCK            (SQLITE_IOERR | (8<<8))
        !           444: #define SQLITE_IOERR_RDLOCK            (SQLITE_IOERR | (9<<8))
        !           445: #define SQLITE_IOERR_DELETE            (SQLITE_IOERR | (10<<8))
        !           446: #define SQLITE_IOERR_BLOCKED           (SQLITE_IOERR | (11<<8))
        !           447: #define SQLITE_IOERR_NOMEM             (SQLITE_IOERR | (12<<8))
        !           448: #define SQLITE_IOERR_ACCESS            (SQLITE_IOERR | (13<<8))
        !           449: #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8))
        !           450: #define SQLITE_IOERR_LOCK              (SQLITE_IOERR | (15<<8))
        !           451: #define SQLITE_IOERR_CLOSE             (SQLITE_IOERR | (16<<8))
        !           452: #define SQLITE_IOERR_DIR_CLOSE         (SQLITE_IOERR | (17<<8))
        !           453: #define SQLITE_IOERR_SHMOPEN           (SQLITE_IOERR | (18<<8))
        !           454: #define SQLITE_IOERR_SHMSIZE           (SQLITE_IOERR | (19<<8))
        !           455: #define SQLITE_IOERR_SHMLOCK           (SQLITE_IOERR | (20<<8))
        !           456: #define SQLITE_IOERR_SHMMAP            (SQLITE_IOERR | (21<<8))
        !           457: #define SQLITE_IOERR_SEEK              (SQLITE_IOERR | (22<<8))
        !           458: #define SQLITE_LOCKED_SHAREDCACHE      (SQLITE_LOCKED |  (1<<8))
        !           459: #define SQLITE_BUSY_RECOVERY           (SQLITE_BUSY   |  (1<<8))
        !           460: #define SQLITE_CANTOPEN_NOTEMPDIR      (SQLITE_CANTOPEN | (1<<8))
        !           461: #define SQLITE_CORRUPT_VTAB            (SQLITE_CORRUPT | (1<<8))
        !           462: #define SQLITE_READONLY_RECOVERY       (SQLITE_READONLY | (1<<8))
        !           463: #define SQLITE_READONLY_CANTLOCK       (SQLITE_READONLY | (2<<8))
        !           464: 
        !           465: /*
        !           466: ** CAPI3REF: Flags For File Open Operations
        !           467: **
        !           468: ** These bit values are intended for use in the
        !           469: ** 3rd parameter to the [sqlite3_open_v2()] interface and
        !           470: ** in the 4th parameter to the [sqlite3_vfs.xOpen] method.
        !           471: */
        !           472: #define SQLITE_OPEN_READONLY         0x00000001  /* Ok for sqlite3_open_v2() */
        !           473: #define SQLITE_OPEN_READWRITE        0x00000002  /* Ok for sqlite3_open_v2() */
        !           474: #define SQLITE_OPEN_CREATE           0x00000004  /* Ok for sqlite3_open_v2() */
        !           475: #define SQLITE_OPEN_DELETEONCLOSE    0x00000008  /* VFS only */
        !           476: #define SQLITE_OPEN_EXCLUSIVE        0x00000010  /* VFS only */
        !           477: #define SQLITE_OPEN_AUTOPROXY        0x00000020  /* VFS only */
        !           478: #define SQLITE_OPEN_URI              0x00000040  /* Ok for sqlite3_open_v2() */
        !           479: #define SQLITE_OPEN_MAIN_DB          0x00000100  /* VFS only */
        !           480: #define SQLITE_OPEN_TEMP_DB          0x00000200  /* VFS only */
        !           481: #define SQLITE_OPEN_TRANSIENT_DB     0x00000400  /* VFS only */
        !           482: #define SQLITE_OPEN_MAIN_JOURNAL     0x00000800  /* VFS only */
        !           483: #define SQLITE_OPEN_TEMP_JOURNAL     0x00001000  /* VFS only */
        !           484: #define SQLITE_OPEN_SUBJOURNAL       0x00002000  /* VFS only */
        !           485: #define SQLITE_OPEN_MASTER_JOURNAL   0x00004000  /* VFS only */
        !           486: #define SQLITE_OPEN_NOMUTEX          0x00008000  /* Ok for sqlite3_open_v2() */
        !           487: #define SQLITE_OPEN_FULLMUTEX        0x00010000  /* Ok for sqlite3_open_v2() */
        !           488: #define SQLITE_OPEN_SHAREDCACHE      0x00020000  /* Ok for sqlite3_open_v2() */
        !           489: #define SQLITE_OPEN_PRIVATECACHE     0x00040000  /* Ok for sqlite3_open_v2() */
        !           490: #define SQLITE_OPEN_WAL              0x00080000  /* VFS only */
        !           491: 
        !           492: /* Reserved:                         0x00F00000 */
        !           493: 
        !           494: /*
        !           495: ** CAPI3REF: Device Characteristics
        !           496: **
        !           497: ** The xDeviceCharacteristics method of the [sqlite3_io_methods]
        !           498: ** object returns an integer which is a vector of the these
        !           499: ** bit values expressing I/O characteristics of the mass storage
        !           500: ** device that holds the file that the [sqlite3_io_methods]
        !           501: ** refers to.
        !           502: **
        !           503: ** The SQLITE_IOCAP_ATOMIC property means that all writes of
        !           504: ** any size are atomic.  The SQLITE_IOCAP_ATOMICnnn values
        !           505: ** mean that writes of blocks that are nnn bytes in size and
        !           506: ** are aligned to an address which is an integer multiple of
        !           507: ** nnn are atomic.  The SQLITE_IOCAP_SAFE_APPEND value means
        !           508: ** that when data is appended to a file, the data is appended
        !           509: ** first then the size of the file is extended, never the other
        !           510: ** way around.  The SQLITE_IOCAP_SEQUENTIAL property means that
        !           511: ** information is written to disk in the same order as calls
        !           512: ** to xWrite().
        !           513: */
        !           514: #define SQLITE_IOCAP_ATOMIC                 0x00000001
        !           515: #define SQLITE_IOCAP_ATOMIC512              0x00000002
        !           516: #define SQLITE_IOCAP_ATOMIC1K               0x00000004
        !           517: #define SQLITE_IOCAP_ATOMIC2K               0x00000008
        !           518: #define SQLITE_IOCAP_ATOMIC4K               0x00000010
        !           519: #define SQLITE_IOCAP_ATOMIC8K               0x00000020
        !           520: #define SQLITE_IOCAP_ATOMIC16K              0x00000040
        !           521: #define SQLITE_IOCAP_ATOMIC32K              0x00000080
        !           522: #define SQLITE_IOCAP_ATOMIC64K              0x00000100
        !           523: #define SQLITE_IOCAP_SAFE_APPEND            0x00000200
        !           524: #define SQLITE_IOCAP_SEQUENTIAL             0x00000400
        !           525: #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN  0x00000800
        !           526: 
        !           527: /*
        !           528: ** CAPI3REF: File Locking Levels
        !           529: **
        !           530: ** SQLite uses one of these integer values as the second
        !           531: ** argument to calls it makes to the xLock() and xUnlock() methods
        !           532: ** of an [sqlite3_io_methods] object.
        !           533: */
        !           534: #define SQLITE_LOCK_NONE          0
        !           535: #define SQLITE_LOCK_SHARED        1
        !           536: #define SQLITE_LOCK_RESERVED      2
        !           537: #define SQLITE_LOCK_PENDING       3
        !           538: #define SQLITE_LOCK_EXCLUSIVE     4
        !           539: 
        !           540: /*
        !           541: ** CAPI3REF: Synchronization Type Flags
        !           542: **
        !           543: ** When SQLite invokes the xSync() method of an
        !           544: ** [sqlite3_io_methods] object it uses a combination of
        !           545: ** these integer values as the second argument.
        !           546: **
        !           547: ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
        !           548: ** sync operation only needs to flush data to mass storage.  Inode
        !           549: ** information need not be flushed. If the lower four bits of the flag
        !           550: ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics.
        !           551: ** If the lower four bits equal SQLITE_SYNC_FULL, that means
        !           552: ** to use Mac OS X style fullsync instead of fsync().
        !           553: **
        !           554: ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags
        !           555: ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL
        !           556: ** settings.  The [synchronous pragma] determines when calls to the
        !           557: ** xSync VFS method occur and applies uniformly across all platforms.
        !           558: ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how
        !           559: ** energetic or rigorous or forceful the sync operations are and
        !           560: ** only make a difference on Mac OSX for the default SQLite code.
        !           561: ** (Third-party VFS implementations might also make the distinction
        !           562: ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the
        !           563: ** operating systems natively supported by SQLite, only Mac OSX
        !           564: ** cares about the difference.)
        !           565: */
        !           566: #define SQLITE_SYNC_NORMAL        0x00002
        !           567: #define SQLITE_SYNC_FULL          0x00003
        !           568: #define SQLITE_SYNC_DATAONLY      0x00010
        !           569: 
        !           570: /*
        !           571: ** CAPI3REF: OS Interface Open File Handle
        !           572: **
        !           573: ** An [sqlite3_file] object represents an open file in the 
        !           574: ** [sqlite3_vfs | OS interface layer].  Individual OS interface
        !           575: ** implementations will
        !           576: ** want to subclass this object by appending additional fields
        !           577: ** for their own use.  The pMethods entry is a pointer to an
        !           578: ** [sqlite3_io_methods] object that defines methods for performing
        !           579: ** I/O operations on the open file.
        !           580: */
        !           581: typedef struct sqlite3_file sqlite3_file;
        !           582: struct sqlite3_file {
        !           583:   const struct sqlite3_io_methods *pMethods;  /* Methods for an open file */
        !           584: };
        !           585: 
        !           586: /*
        !           587: ** CAPI3REF: OS Interface File Virtual Methods Object
        !           588: **
        !           589: ** Every file opened by the [sqlite3_vfs.xOpen] method populates an
        !           590: ** [sqlite3_file] object (or, more commonly, a subclass of the
        !           591: ** [sqlite3_file] object) with a pointer to an instance of this object.
        !           592: ** This object defines the methods used to perform various operations
        !           593: ** against the open file represented by the [sqlite3_file] object.
        !           594: **
        !           595: ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 
        !           596: ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method
        !           597: ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed.  The
        !           598: ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen]
        !           599: ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element
        !           600: ** to NULL.
        !           601: **
        !           602: ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
        !           603: ** [SQLITE_SYNC_FULL].  The first choice is the normal fsync().
        !           604: ** The second choice is a Mac OS X style fullsync.  The [SQLITE_SYNC_DATAONLY]
        !           605: ** flag may be ORed in to indicate that only the data of the file
        !           606: ** and not its inode needs to be synced.
        !           607: **
        !           608: ** The integer values to xLock() and xUnlock() are one of
        !           609: ** <ul>
        !           610: ** <li> [SQLITE_LOCK_NONE],
        !           611: ** <li> [SQLITE_LOCK_SHARED],
        !           612: ** <li> [SQLITE_LOCK_RESERVED],
        !           613: ** <li> [SQLITE_LOCK_PENDING], or
        !           614: ** <li> [SQLITE_LOCK_EXCLUSIVE].
        !           615: ** </ul>
        !           616: ** xLock() increases the lock. xUnlock() decreases the lock.
        !           617: ** The xCheckReservedLock() method checks whether any database connection,
        !           618: ** either in this process or in some other process, is holding a RESERVED,
        !           619: ** PENDING, or EXCLUSIVE lock on the file.  It returns true
        !           620: ** if such a lock exists and false otherwise.
        !           621: **
        !           622: ** The xFileControl() method is a generic interface that allows custom
        !           623: ** VFS implementations to directly control an open file using the
        !           624: ** [sqlite3_file_control()] interface.  The second "op" argument is an
        !           625: ** integer opcode.  The third argument is a generic pointer intended to
        !           626: ** point to a structure that may contain arguments or space in which to
        !           627: ** write return values.  Potential uses for xFileControl() might be
        !           628: ** functions to enable blocking locks with timeouts, to change the
        !           629: ** locking strategy (for example to use dot-file locks), to inquire
        !           630: ** about the status of a lock, or to break stale locks.  The SQLite
        !           631: ** core reserves all opcodes less than 100 for its own use.
        !           632: ** A [SQLITE_FCNTL_LOCKSTATE | list of opcodes] less than 100 is available.
        !           633: ** Applications that define a custom xFileControl method should use opcodes
        !           634: ** greater than 100 to avoid conflicts.  VFS implementations should
        !           635: ** return [SQLITE_NOTFOUND] for file control opcodes that they do not
        !           636: ** recognize.
        !           637: **
        !           638: ** The xSectorSize() method returns the sector size of the
        !           639: ** device that underlies the file.  The sector size is the
        !           640: ** minimum write that can be performed without disturbing
        !           641: ** other bytes in the file.  The xDeviceCharacteristics()
        !           642: ** method returns a bit vector describing behaviors of the
        !           643: ** underlying device:
        !           644: **
        !           645: ** <ul>
        !           646: ** <li> [SQLITE_IOCAP_ATOMIC]
        !           647: ** <li> [SQLITE_IOCAP_ATOMIC512]
        !           648: ** <li> [SQLITE_IOCAP_ATOMIC1K]
        !           649: ** <li> [SQLITE_IOCAP_ATOMIC2K]
        !           650: ** <li> [SQLITE_IOCAP_ATOMIC4K]
        !           651: ** <li> [SQLITE_IOCAP_ATOMIC8K]
        !           652: ** <li> [SQLITE_IOCAP_ATOMIC16K]
        !           653: ** <li> [SQLITE_IOCAP_ATOMIC32K]
        !           654: ** <li> [SQLITE_IOCAP_ATOMIC64K]
        !           655: ** <li> [SQLITE_IOCAP_SAFE_APPEND]
        !           656: ** <li> [SQLITE_IOCAP_SEQUENTIAL]
        !           657: ** </ul>
        !           658: **
        !           659: ** The SQLITE_IOCAP_ATOMIC property means that all writes of
        !           660: ** any size are atomic.  The SQLITE_IOCAP_ATOMICnnn values
        !           661: ** mean that writes of blocks that are nnn bytes in size and
        !           662: ** are aligned to an address which is an integer multiple of
        !           663: ** nnn are atomic.  The SQLITE_IOCAP_SAFE_APPEND value means
        !           664: ** that when data is appended to a file, the data is appended
        !           665: ** first then the size of the file is extended, never the other
        !           666: ** way around.  The SQLITE_IOCAP_SEQUENTIAL property means that
        !           667: ** information is written to disk in the same order as calls
        !           668: ** to xWrite().
        !           669: **
        !           670: ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill
        !           671: ** in the unread portions of the buffer with zeros.  A VFS that
        !           672: ** fails to zero-fill short reads might seem to work.  However,
        !           673: ** failure to zero-fill short reads will eventually lead to
        !           674: ** database corruption.
        !           675: */
        !           676: typedef struct sqlite3_io_methods sqlite3_io_methods;
        !           677: struct sqlite3_io_methods {
        !           678:   int iVersion;
        !           679:   int (*xClose)(sqlite3_file*);
        !           680:   int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
        !           681:   int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
        !           682:   int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
        !           683:   int (*xSync)(sqlite3_file*, int flags);
        !           684:   int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);
        !           685:   int (*xLock)(sqlite3_file*, int);
        !           686:   int (*xUnlock)(sqlite3_file*, int);
        !           687:   int (*xCheckReservedLock)(sqlite3_file*, int *pResOut);
        !           688:   int (*xFileControl)(sqlite3_file*, int op, void *pArg);
        !           689:   int (*xSectorSize)(sqlite3_file*);
        !           690:   int (*xDeviceCharacteristics)(sqlite3_file*);
        !           691:   /* Methods above are valid for version 1 */
        !           692:   int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
        !           693:   int (*xShmLock)(sqlite3_file*, int offset, int n, int flags);
        !           694:   void (*xShmBarrier)(sqlite3_file*);
        !           695:   int (*xShmUnmap)(sqlite3_file*, int deleteFlag);
        !           696:   /* Methods above are valid for version 2 */
        !           697:   /* Additional methods may be added in future releases */
        !           698: };
        !           699: 
        !           700: /*
        !           701: ** CAPI3REF: Standard File Control Opcodes
        !           702: **
        !           703: ** These integer constants are opcodes for the xFileControl method
        !           704: ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
        !           705: ** interface.
        !           706: **
        !           707: ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging.  This
        !           708: ** opcode causes the xFileControl method to write the current state of
        !           709: ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
        !           710: ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
        !           711: ** into an integer that the pArg argument points to. This capability
        !           712: ** is used during testing and only needs to be supported when SQLITE_TEST
        !           713: ** is defined.
        !           714: **
        !           715: ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
        !           716: ** layer a hint of how large the database file will grow to be during the
        !           717: ** current transaction.  This hint is not guaranteed to be accurate but it
        !           718: ** is often close.  The underlying VFS might choose to preallocate database
        !           719: ** file space based on this hint in order to help writes to the database
        !           720: ** file run faster.
        !           721: **
        !           722: ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
        !           723: ** extends and truncates the database file in chunks of a size specified
        !           724: ** by the user. The fourth argument to [sqlite3_file_control()] should 
        !           725: ** point to an integer (type int) containing the new chunk-size to use
        !           726: ** for the nominated database. Allocating database file space in large
        !           727: ** chunks (say 1MB at a time), may reduce file-system fragmentation and
        !           728: ** improve performance on some systems.
        !           729: **
        !           730: ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
        !           731: ** to the [sqlite3_file] object associated with a particular database
        !           732: ** connection.  See the [sqlite3_file_control()] documentation for
        !           733: ** additional information.
        !           734: **
        !           735: ** ^(The [SQLITE_FCNTL_SYNC_OMITTED] opcode is generated internally by
        !           736: ** SQLite and sent to all VFSes in place of a call to the xSync method
        !           737: ** when the database connection has [PRAGMA synchronous] set to OFF.)^
        !           738: ** Some specialized VFSes need this signal in order to operate correctly
        !           739: ** when [PRAGMA synchronous | PRAGMA synchronous=OFF] is set, but most 
        !           740: ** VFSes do not need this signal and should silently ignore this opcode.
        !           741: ** Applications should not call [sqlite3_file_control()] with this
        !           742: ** opcode as doing so may disrupt the operation of the specialized VFSes
        !           743: ** that do require it.  
        !           744: */
        !           745: #define SQLITE_FCNTL_LOCKSTATE        1
        !           746: #define SQLITE_GET_LOCKPROXYFILE      2
        !           747: #define SQLITE_SET_LOCKPROXYFILE      3
        !           748: #define SQLITE_LAST_ERRNO             4
        !           749: #define SQLITE_FCNTL_SIZE_HINT        5
        !           750: #define SQLITE_FCNTL_CHUNK_SIZE       6
        !           751: #define SQLITE_FCNTL_FILE_POINTER     7
        !           752: #define SQLITE_FCNTL_SYNC_OMITTED     8
        !           753: 
        !           754: 
        !           755: /*
        !           756: ** CAPI3REF: Mutex Handle
        !           757: **
        !           758: ** The mutex module within SQLite defines [sqlite3_mutex] to be an
        !           759: ** abstract type for a mutex object.  The SQLite core never looks
        !           760: ** at the internal representation of an [sqlite3_mutex].  It only
        !           761: ** deals with pointers to the [sqlite3_mutex] object.
        !           762: **
        !           763: ** Mutexes are created using [sqlite3_mutex_alloc()].
        !           764: */
        !           765: typedef struct sqlite3_mutex sqlite3_mutex;
        !           766: 
        !           767: /*
        !           768: ** CAPI3REF: OS Interface Object
        !           769: **
        !           770: ** An instance of the sqlite3_vfs object defines the interface between
        !           771: ** the SQLite core and the underlying operating system.  The "vfs"
        !           772: ** in the name of the object stands for "virtual file system".  See
        !           773: ** the [VFS | VFS documentation] for further information.
        !           774: **
        !           775: ** The value of the iVersion field is initially 1 but may be larger in
        !           776: ** future versions of SQLite.  Additional fields may be appended to this
        !           777: ** object when the iVersion value is increased.  Note that the structure
        !           778: ** of the sqlite3_vfs object changes in the transaction between
        !           779: ** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not
        !           780: ** modified.
        !           781: **
        !           782: ** The szOsFile field is the size of the subclassed [sqlite3_file]
        !           783: ** structure used by this VFS.  mxPathname is the maximum length of
        !           784: ** a pathname in this VFS.
        !           785: **
        !           786: ** Registered sqlite3_vfs objects are kept on a linked list formed by
        !           787: ** the pNext pointer.  The [sqlite3_vfs_register()]
        !           788: ** and [sqlite3_vfs_unregister()] interfaces manage this list
        !           789: ** in a thread-safe way.  The [sqlite3_vfs_find()] interface
        !           790: ** searches the list.  Neither the application code nor the VFS
        !           791: ** implementation should use the pNext pointer.
        !           792: **
        !           793: ** The pNext field is the only field in the sqlite3_vfs
        !           794: ** structure that SQLite will ever modify.  SQLite will only access
        !           795: ** or modify this field while holding a particular static mutex.
        !           796: ** The application should never modify anything within the sqlite3_vfs
        !           797: ** object once the object has been registered.
        !           798: **
        !           799: ** The zName field holds the name of the VFS module.  The name must
        !           800: ** be unique across all VFS modules.
        !           801: **
        !           802: ** [[sqlite3_vfs.xOpen]]
        !           803: ** ^SQLite guarantees that the zFilename parameter to xOpen
        !           804: ** is either a NULL pointer or string obtained
        !           805: ** from xFullPathname() with an optional suffix added.
        !           806: ** ^If a suffix is added to the zFilename parameter, it will
        !           807: ** consist of a single "-" character followed by no more than
        !           808: ** 10 alphanumeric and/or "-" characters.
        !           809: ** ^SQLite further guarantees that
        !           810: ** the string will be valid and unchanged until xClose() is
        !           811: ** called. Because of the previous sentence,
        !           812: ** the [sqlite3_file] can safely store a pointer to the
        !           813: ** filename if it needs to remember the filename for some reason.
        !           814: ** If the zFilename parameter to xOpen is a NULL pointer then xOpen
        !           815: ** must invent its own temporary name for the file.  ^Whenever the 
        !           816: ** xFilename parameter is NULL it will also be the case that the
        !           817: ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
        !           818: **
        !           819: ** The flags argument to xOpen() includes all bits set in
        !           820: ** the flags argument to [sqlite3_open_v2()].  Or if [sqlite3_open()]
        !           821: ** or [sqlite3_open16()] is used, then flags includes at least
        !           822: ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 
        !           823: ** If xOpen() opens a file read-only then it sets *pOutFlags to
        !           824: ** include [SQLITE_OPEN_READONLY].  Other bits in *pOutFlags may be set.
        !           825: **
        !           826: ** ^(SQLite will also add one of the following flags to the xOpen()
        !           827: ** call, depending on the object being opened:
        !           828: **
        !           829: ** <ul>
        !           830: ** <li>  [SQLITE_OPEN_MAIN_DB]
        !           831: ** <li>  [SQLITE_OPEN_MAIN_JOURNAL]
        !           832: ** <li>  [SQLITE_OPEN_TEMP_DB]
        !           833: ** <li>  [SQLITE_OPEN_TEMP_JOURNAL]
        !           834: ** <li>  [SQLITE_OPEN_TRANSIENT_DB]
        !           835: ** <li>  [SQLITE_OPEN_SUBJOURNAL]
        !           836: ** <li>  [SQLITE_OPEN_MASTER_JOURNAL]
        !           837: ** <li>  [SQLITE_OPEN_WAL]
        !           838: ** </ul>)^
        !           839: **
        !           840: ** The file I/O implementation can use the object type flags to
        !           841: ** change the way it deals with files.  For example, an application
        !           842: ** that does not care about crash recovery or rollback might make
        !           843: ** the open of a journal file a no-op.  Writes to this journal would
        !           844: ** also be no-ops, and any attempt to read the journal would return
        !           845: ** SQLITE_IOERR.  Or the implementation might recognize that a database
        !           846: ** file will be doing page-aligned sector reads and writes in a random
        !           847: ** order and set up its I/O subsystem accordingly.
        !           848: **
        !           849: ** SQLite might also add one of the following flags to the xOpen method:
        !           850: **
        !           851: ** <ul>
        !           852: ** <li> [SQLITE_OPEN_DELETEONCLOSE]
        !           853: ** <li> [SQLITE_OPEN_EXCLUSIVE]
        !           854: ** </ul>
        !           855: **
        !           856: ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
        !           857: ** deleted when it is closed.  ^The [SQLITE_OPEN_DELETEONCLOSE]
        !           858: ** will be set for TEMP databases and their journals, transient
        !           859: ** databases, and subjournals.
        !           860: **
        !           861: ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction
        !           862: ** with the [SQLITE_OPEN_CREATE] flag, which are both directly
        !           863: ** analogous to the O_EXCL and O_CREAT flags of the POSIX open()
        !           864: ** API.  The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 
        !           865: ** SQLITE_OPEN_CREATE, is used to indicate that file should always
        !           866: ** be created, and that it is an error if it already exists.
        !           867: ** It is <i>not</i> used to indicate the file should be opened 
        !           868: ** for exclusive access.
        !           869: **
        !           870: ** ^At least szOsFile bytes of memory are allocated by SQLite
        !           871: ** to hold the  [sqlite3_file] structure passed as the third
        !           872: ** argument to xOpen.  The xOpen method does not have to
        !           873: ** allocate the structure; it should just fill it in.  Note that
        !           874: ** the xOpen method must set the sqlite3_file.pMethods to either
        !           875: ** a valid [sqlite3_io_methods] object or to NULL.  xOpen must do
        !           876: ** this even if the open fails.  SQLite expects that the sqlite3_file.pMethods
        !           877: ** element will be valid after xOpen returns regardless of the success
        !           878: ** or failure of the xOpen call.
        !           879: **
        !           880: ** [[sqlite3_vfs.xAccess]]
        !           881: ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
        !           882: ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
        !           883: ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
        !           884: ** to test whether a file is at least readable.   The file can be a
        !           885: ** directory.
        !           886: **
        !           887: ** ^SQLite will always allocate at least mxPathname+1 bytes for the
        !           888: ** output buffer xFullPathname.  The exact size of the output buffer
        !           889: ** is also passed as a parameter to both  methods. If the output buffer
        !           890: ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
        !           891: ** handled as a fatal error by SQLite, vfs implementations should endeavor
        !           892: ** to prevent this by setting mxPathname to a sufficiently large value.
        !           893: **
        !           894: ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64()
        !           895: ** interfaces are not strictly a part of the filesystem, but they are
        !           896: ** included in the VFS structure for completeness.
        !           897: ** The xRandomness() function attempts to return nBytes bytes
        !           898: ** of good-quality randomness into zOut.  The return value is
        !           899: ** the actual number of bytes of randomness obtained.
        !           900: ** The xSleep() method causes the calling thread to sleep for at
        !           901: ** least the number of microseconds given.  ^The xCurrentTime()
        !           902: ** method returns a Julian Day Number for the current date and time as
        !           903: ** a floating point value.
        !           904: ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian
        !           905: ** Day Number multiplied by 86400000 (the number of milliseconds in 
        !           906: ** a 24-hour day).  
        !           907: ** ^SQLite will use the xCurrentTimeInt64() method to get the current
        !           908: ** date and time if that method is available (if iVersion is 2 or 
        !           909: ** greater and the function pointer is not NULL) and will fall back
        !           910: ** to xCurrentTime() if xCurrentTimeInt64() is unavailable.
        !           911: **
        !           912: ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces
        !           913: ** are not used by the SQLite core.  These optional interfaces are provided
        !           914: ** by some VFSes to facilitate testing of the VFS code. By overriding 
        !           915: ** system calls with functions under its control, a test program can
        !           916: ** simulate faults and error conditions that would otherwise be difficult
        !           917: ** or impossible to induce.  The set of system calls that can be overridden
        !           918: ** varies from one VFS to another, and from one version of the same VFS to the
        !           919: ** next.  Applications that use these interfaces must be prepared for any
        !           920: ** or all of these interfaces to be NULL or for their behavior to change
        !           921: ** from one release to the next.  Applications must not attempt to access
        !           922: ** any of these methods if the iVersion of the VFS is less than 3.
        !           923: */
        !           924: typedef struct sqlite3_vfs sqlite3_vfs;
        !           925: typedef void (*sqlite3_syscall_ptr)(void);
        !           926: struct sqlite3_vfs {
        !           927:   int iVersion;            /* Structure version number (currently 3) */
        !           928:   int szOsFile;            /* Size of subclassed sqlite3_file */
        !           929:   int mxPathname;          /* Maximum file pathname length */
        !           930:   sqlite3_vfs *pNext;      /* Next registered VFS */
        !           931:   const char *zName;       /* Name of this virtual file system */
        !           932:   void *pAppData;          /* Pointer to application-specific data */
        !           933:   int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*,
        !           934:                int flags, int *pOutFlags);
        !           935:   int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);
        !           936:   int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);
        !           937:   int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);
        !           938:   void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);
        !           939:   void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
        !           940:   void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);
        !           941:   void (*xDlClose)(sqlite3_vfs*, void*);
        !           942:   int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
        !           943:   int (*xSleep)(sqlite3_vfs*, int microseconds);
        !           944:   int (*xCurrentTime)(sqlite3_vfs*, double*);
        !           945:   int (*xGetLastError)(sqlite3_vfs*, int, char *);
        !           946:   /*
        !           947:   ** The methods above are in version 1 of the sqlite_vfs object
        !           948:   ** definition.  Those that follow are added in version 2 or later
        !           949:   */
        !           950:   int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);
        !           951:   /*
        !           952:   ** The methods above are in versions 1 and 2 of the sqlite_vfs object.
        !           953:   ** Those below are for version 3 and greater.
        !           954:   */
        !           955:   int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr);
        !           956:   sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName);
        !           957:   const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName);
        !           958:   /*
        !           959:   ** The methods above are in versions 1 through 3 of the sqlite_vfs object.
        !           960:   ** New fields may be appended in figure versions.  The iVersion
        !           961:   ** value will increment whenever this happens. 
        !           962:   */
        !           963: };
        !           964: 
        !           965: /*
        !           966: ** CAPI3REF: Flags for the xAccess VFS method
        !           967: **
        !           968: ** These integer constants can be used as the third parameter to
        !           969: ** the xAccess method of an [sqlite3_vfs] object.  They determine
        !           970: ** what kind of permissions the xAccess method is looking for.
        !           971: ** With SQLITE_ACCESS_EXISTS, the xAccess method
        !           972: ** simply checks whether the file exists.
        !           973: ** With SQLITE_ACCESS_READWRITE, the xAccess method
        !           974: ** checks whether the named directory is both readable and writable
        !           975: ** (in other words, if files can be added, removed, and renamed within
        !           976: ** the directory).
        !           977: ** The SQLITE_ACCESS_READWRITE constant is currently used only by the
        !           978: ** [temp_store_directory pragma], though this could change in a future
        !           979: ** release of SQLite.
        !           980: ** With SQLITE_ACCESS_READ, the xAccess method
        !           981: ** checks whether the file is readable.  The SQLITE_ACCESS_READ constant is
        !           982: ** currently unused, though it might be used in a future release of
        !           983: ** SQLite.
        !           984: */
        !           985: #define SQLITE_ACCESS_EXISTS    0
        !           986: #define SQLITE_ACCESS_READWRITE 1   /* Used by PRAGMA temp_store_directory */
        !           987: #define SQLITE_ACCESS_READ      2   /* Unused */
        !           988: 
        !           989: /*
        !           990: ** CAPI3REF: Flags for the xShmLock VFS method
        !           991: **
        !           992: ** These integer constants define the various locking operations
        !           993: ** allowed by the xShmLock method of [sqlite3_io_methods].  The
        !           994: ** following are the only legal combinations of flags to the
        !           995: ** xShmLock method:
        !           996: **
        !           997: ** <ul>
        !           998: ** <li>  SQLITE_SHM_LOCK | SQLITE_SHM_SHARED
        !           999: ** <li>  SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE
        !          1000: ** <li>  SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED
        !          1001: ** <li>  SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE
        !          1002: ** </ul>
        !          1003: **
        !          1004: ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
        !          1005: ** was given no the corresponding lock.  
        !          1006: **
        !          1007: ** The xShmLock method can transition between unlocked and SHARED or
        !          1008: ** between unlocked and EXCLUSIVE.  It cannot transition between SHARED
        !          1009: ** and EXCLUSIVE.
        !          1010: */
        !          1011: #define SQLITE_SHM_UNLOCK       1
        !          1012: #define SQLITE_SHM_LOCK         2
        !          1013: #define SQLITE_SHM_SHARED       4
        !          1014: #define SQLITE_SHM_EXCLUSIVE    8
        !          1015: 
        !          1016: /*
        !          1017: ** CAPI3REF: Maximum xShmLock index
        !          1018: **
        !          1019: ** The xShmLock method on [sqlite3_io_methods] may use values
        !          1020: ** between 0 and this upper bound as its "offset" argument.
        !          1021: ** The SQLite core will never attempt to acquire or release a
        !          1022: ** lock outside of this range
        !          1023: */
        !          1024: #define SQLITE_SHM_NLOCK        8
        !          1025: 
        !          1026: 
        !          1027: /*
        !          1028: ** CAPI3REF: Initialize The SQLite Library
        !          1029: **
        !          1030: ** ^The sqlite3_initialize() routine initializes the
        !          1031: ** SQLite library.  ^The sqlite3_shutdown() routine
        !          1032: ** deallocates any resources that were allocated by sqlite3_initialize().
        !          1033: ** These routines are designed to aid in process initialization and
        !          1034: ** shutdown on embedded systems.  Workstation applications using
        !          1035: ** SQLite normally do not need to invoke either of these routines.
        !          1036: **
        !          1037: ** A call to sqlite3_initialize() is an "effective" call if it is
        !          1038: ** the first time sqlite3_initialize() is invoked during the lifetime of
        !          1039: ** the process, or if it is the first time sqlite3_initialize() is invoked
        !          1040: ** following a call to sqlite3_shutdown().  ^(Only an effective call
        !          1041: ** of sqlite3_initialize() does any initialization.  All other calls
        !          1042: ** are harmless no-ops.)^
        !          1043: **
        !          1044: ** A call to sqlite3_shutdown() is an "effective" call if it is the first
        !          1045: ** call to sqlite3_shutdown() since the last sqlite3_initialize().  ^(Only
        !          1046: ** an effective call to sqlite3_shutdown() does any deinitialization.
        !          1047: ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
        !          1048: **
        !          1049: ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
        !          1050: ** is not.  The sqlite3_shutdown() interface must only be called from a
        !          1051: ** single thread.  All open [database connections] must be closed and all
        !          1052: ** other SQLite resources must be deallocated prior to invoking
        !          1053: ** sqlite3_shutdown().
        !          1054: **
        !          1055: ** Among other things, ^sqlite3_initialize() will invoke
        !          1056: ** sqlite3_os_init().  Similarly, ^sqlite3_shutdown()
        !          1057: ** will invoke sqlite3_os_end().
        !          1058: **
        !          1059: ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
        !          1060: ** ^If for some reason, sqlite3_initialize() is unable to initialize
        !          1061: ** the library (perhaps it is unable to allocate a needed resource such
        !          1062: ** as a mutex) it returns an [error code] other than [SQLITE_OK].
        !          1063: **
        !          1064: ** ^The sqlite3_initialize() routine is called internally by many other
        !          1065: ** SQLite interfaces so that an application usually does not need to
        !          1066: ** invoke sqlite3_initialize() directly.  For example, [sqlite3_open()]
        !          1067: ** calls sqlite3_initialize() so the SQLite library will be automatically
        !          1068: ** initialized when [sqlite3_open()] is called if it has not be initialized
        !          1069: ** already.  ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
        !          1070: ** compile-time option, then the automatic calls to sqlite3_initialize()
        !          1071: ** are omitted and the application must call sqlite3_initialize() directly
        !          1072: ** prior to using any other SQLite interface.  For maximum portability,
        !          1073: ** it is recommended that applications always invoke sqlite3_initialize()
        !          1074: ** directly prior to using any other SQLite interface.  Future releases
        !          1075: ** of SQLite may require this.  In other words, the behavior exhibited
        !          1076: ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
        !          1077: ** default behavior in some future release of SQLite.
        !          1078: **
        !          1079: ** The sqlite3_os_init() routine does operating-system specific
        !          1080: ** initialization of the SQLite library.  The sqlite3_os_end()
        !          1081: ** routine undoes the effect of sqlite3_os_init().  Typical tasks
        !          1082: ** performed by these routines include allocation or deallocation
        !          1083: ** of static resources, initialization of global variables,
        !          1084: ** setting up a default [sqlite3_vfs] module, or setting up
        !          1085: ** a default configuration using [sqlite3_config()].
        !          1086: **
        !          1087: ** The application should never invoke either sqlite3_os_init()
        !          1088: ** or sqlite3_os_end() directly.  The application should only invoke
        !          1089: ** sqlite3_initialize() and sqlite3_shutdown().  The sqlite3_os_init()
        !          1090: ** interface is called automatically by sqlite3_initialize() and
        !          1091: ** sqlite3_os_end() is called by sqlite3_shutdown().  Appropriate
        !          1092: ** implementations for sqlite3_os_init() and sqlite3_os_end()
        !          1093: ** are built into SQLite when it is compiled for Unix, Windows, or OS/2.
        !          1094: ** When [custom builds | built for other platforms]
        !          1095: ** (using the [SQLITE_OS_OTHER=1] compile-time
        !          1096: ** option) the application must supply a suitable implementation for
        !          1097: ** sqlite3_os_init() and sqlite3_os_end().  An application-supplied
        !          1098: ** implementation of sqlite3_os_init() or sqlite3_os_end()
        !          1099: ** must return [SQLITE_OK] on success and some other [error code] upon
        !          1100: ** failure.
        !          1101: */
        !          1102: SQLITE_API int sqlite3_initialize(void);
        !          1103: SQLITE_API int sqlite3_shutdown(void);
        !          1104: SQLITE_API int sqlite3_os_init(void);
        !          1105: SQLITE_API int sqlite3_os_end(void);
        !          1106: 
        !          1107: /*
        !          1108: ** CAPI3REF: Configuring The SQLite Library
        !          1109: **
        !          1110: ** The sqlite3_config() interface is used to make global configuration
        !          1111: ** changes to SQLite in order to tune SQLite to the specific needs of
        !          1112: ** the application.  The default configuration is recommended for most
        !          1113: ** applications and so this routine is usually not necessary.  It is
        !          1114: ** provided to support rare applications with unusual needs.
        !          1115: **
        !          1116: ** The sqlite3_config() interface is not threadsafe.  The application
        !          1117: ** must insure that no other SQLite interfaces are invoked by other
        !          1118: ** threads while sqlite3_config() is running.  Furthermore, sqlite3_config()
        !          1119: ** may only be invoked prior to library initialization using
        !          1120: ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
        !          1121: ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
        !          1122: ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE.
        !          1123: ** Note, however, that ^sqlite3_config() can be called as part of the
        !          1124: ** implementation of an application-defined [sqlite3_os_init()].
        !          1125: **
        !          1126: ** The first argument to sqlite3_config() is an integer
        !          1127: ** [configuration option] that determines
        !          1128: ** what property of SQLite is to be configured.  Subsequent arguments
        !          1129: ** vary depending on the [configuration option]
        !          1130: ** in the first argument.
        !          1131: **
        !          1132: ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
        !          1133: ** ^If the option is unknown or SQLite is unable to set the option
        !          1134: ** then this routine returns a non-zero [error code].
        !          1135: */
        !          1136: SQLITE_API int sqlite3_config(int, ...);
        !          1137: 
        !          1138: /*
        !          1139: ** CAPI3REF: Configure database connections
        !          1140: **
        !          1141: ** The sqlite3_db_config() interface is used to make configuration
        !          1142: ** changes to a [database connection].  The interface is similar to
        !          1143: ** [sqlite3_config()] except that the changes apply to a single
        !          1144: ** [database connection] (specified in the first argument).
        !          1145: **
        !          1146: ** The second argument to sqlite3_db_config(D,V,...)  is the
        !          1147: ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 
        !          1148: ** that indicates what aspect of the [database connection] is being configured.
        !          1149: ** Subsequent arguments vary depending on the configuration verb.
        !          1150: **
        !          1151: ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
        !          1152: ** the call is considered successful.
        !          1153: */
        !          1154: SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...);
        !          1155: 
        !          1156: /*
        !          1157: ** CAPI3REF: Memory Allocation Routines
        !          1158: **
        !          1159: ** An instance of this object defines the interface between SQLite
        !          1160: ** and low-level memory allocation routines.
        !          1161: **
        !          1162: ** This object is used in only one place in the SQLite interface.
        !          1163: ** A pointer to an instance of this object is the argument to
        !          1164: ** [sqlite3_config()] when the configuration option is
        !          1165: ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC].  
        !          1166: ** By creating an instance of this object
        !          1167: ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])
        !          1168: ** during configuration, an application can specify an alternative
        !          1169: ** memory allocation subsystem for SQLite to use for all of its
        !          1170: ** dynamic memory needs.
        !          1171: **
        !          1172: ** Note that SQLite comes with several [built-in memory allocators]
        !          1173: ** that are perfectly adequate for the overwhelming majority of applications
        !          1174: ** and that this object is only useful to a tiny minority of applications
        !          1175: ** with specialized memory allocation requirements.  This object is
        !          1176: ** also used during testing of SQLite in order to specify an alternative
        !          1177: ** memory allocator that simulates memory out-of-memory conditions in
        !          1178: ** order to verify that SQLite recovers gracefully from such
        !          1179: ** conditions.
        !          1180: **
        !          1181: ** The xMalloc and xFree methods must work like the
        !          1182: ** malloc() and free() functions from the standard C library.
        !          1183: ** The xRealloc method must work like realloc() from the standard C library
        !          1184: ** with the exception that if the second argument to xRealloc is zero,
        !          1185: ** xRealloc must be a no-op - it must not perform any allocation or
        !          1186: ** deallocation.  ^SQLite guarantees that the second argument to
        !          1187: ** xRealloc is always a value returned by a prior call to xRoundup.
        !          1188: ** And so in cases where xRoundup always returns a positive number,
        !          1189: ** xRealloc can perform exactly as the standard library realloc() and
        !          1190: ** still be in compliance with this specification.
        !          1191: **
        !          1192: ** xSize should return the allocated size of a memory allocation
        !          1193: ** previously obtained from xMalloc or xRealloc.  The allocated size
        !          1194: ** is always at least as big as the requested size but may be larger.
        !          1195: **
        !          1196: ** The xRoundup method returns what would be the allocated size of
        !          1197: ** a memory allocation given a particular requested size.  Most memory
        !          1198: ** allocators round up memory allocations at least to the next multiple
        !          1199: ** of 8.  Some allocators round up to a larger multiple or to a power of 2.
        !          1200: ** Every memory allocation request coming in through [sqlite3_malloc()]
        !          1201: ** or [sqlite3_realloc()] first calls xRoundup.  If xRoundup returns 0, 
        !          1202: ** that causes the corresponding memory allocation to fail.
        !          1203: **
        !          1204: ** The xInit method initializes the memory allocator.  (For example,
        !          1205: ** it might allocate any require mutexes or initialize internal data
        !          1206: ** structures.  The xShutdown method is invoked (indirectly) by
        !          1207: ** [sqlite3_shutdown()] and should deallocate any resources acquired
        !          1208: ** by xInit.  The pAppData pointer is used as the only parameter to
        !          1209: ** xInit and xShutdown.
        !          1210: **
        !          1211: ** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes
        !          1212: ** the xInit method, so the xInit method need not be threadsafe.  The
        !          1213: ** xShutdown method is only called from [sqlite3_shutdown()] so it does
        !          1214: ** not need to be threadsafe either.  For all other methods, SQLite
        !          1215: ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
        !          1216: ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
        !          1217: ** it is by default) and so the methods are automatically serialized.
        !          1218: ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other
        !          1219: ** methods must be threadsafe or else make their own arrangements for
        !          1220: ** serialization.
        !          1221: **
        !          1222: ** SQLite will never invoke xInit() more than once without an intervening
        !          1223: ** call to xShutdown().
        !          1224: */
        !          1225: typedef struct sqlite3_mem_methods sqlite3_mem_methods;
        !          1226: struct sqlite3_mem_methods {
        !          1227:   void *(*xMalloc)(int);         /* Memory allocation function */
        !          1228:   void (*xFree)(void*);          /* Free a prior allocation */
        !          1229:   void *(*xRealloc)(void*,int);  /* Resize an allocation */
        !          1230:   int (*xSize)(void*);           /* Return the size of an allocation */
        !          1231:   int (*xRoundup)(int);          /* Round up request size to allocation size */
        !          1232:   int (*xInit)(void*);           /* Initialize the memory allocator */
        !          1233:   void (*xShutdown)(void*);      /* Deinitialize the memory allocator */
        !          1234:   void *pAppData;                /* Argument to xInit() and xShutdown() */
        !          1235: };
        !          1236: 
        !          1237: /*
        !          1238: ** CAPI3REF: Configuration Options
        !          1239: ** KEYWORDS: {configuration option}
        !          1240: **
        !          1241: ** These constants are the available integer configuration options that
        !          1242: ** can be passed as the first argument to the [sqlite3_config()] interface.
        !          1243: **
        !          1244: ** New configuration options may be added in future releases of SQLite.
        !          1245: ** Existing configuration options might be discontinued.  Applications
        !          1246: ** should check the return code from [sqlite3_config()] to make sure that
        !          1247: ** the call worked.  The [sqlite3_config()] interface will return a
        !          1248: ** non-zero [error code] if a discontinued or unsupported configuration option
        !          1249: ** is invoked.
        !          1250: **
        !          1251: ** <dl>
        !          1252: ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
        !          1253: ** <dd>There are no arguments to this option.  ^This option sets the
        !          1254: ** [threading mode] to Single-thread.  In other words, it disables
        !          1255: ** all mutexing and puts SQLite into a mode where it can only be used
        !          1256: ** by a single thread.   ^If SQLite is compiled with
        !          1257: ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
        !          1258: ** it is not possible to change the [threading mode] from its default
        !          1259: ** value of Single-thread and so [sqlite3_config()] will return 
        !          1260: ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD
        !          1261: ** configuration option.</dd>
        !          1262: **
        !          1263: ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt>
        !          1264: ** <dd>There are no arguments to this option.  ^This option sets the
        !          1265: ** [threading mode] to Multi-thread.  In other words, it disables
        !          1266: ** mutexing on [database connection] and [prepared statement] objects.
        !          1267: ** The application is responsible for serializing access to
        !          1268: ** [database connections] and [prepared statements].  But other mutexes
        !          1269: ** are enabled so that SQLite will be safe to use in a multi-threaded
        !          1270: ** environment as long as no two threads attempt to use the same
        !          1271: ** [database connection] at the same time.  ^If SQLite is compiled with
        !          1272: ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
        !          1273: ** it is not possible to set the Multi-thread [threading mode] and
        !          1274: ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
        !          1275: ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
        !          1276: **
        !          1277: ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt>
        !          1278: ** <dd>There are no arguments to this option.  ^This option sets the
        !          1279: ** [threading mode] to Serialized. In other words, this option enables
        !          1280: ** all mutexes including the recursive
        !          1281: ** mutexes on [database connection] and [prepared statement] objects.
        !          1282: ** In this mode (which is the default when SQLite is compiled with
        !          1283: ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
        !          1284: ** to [database connections] and [prepared statements] so that the
        !          1285: ** application is free to use the same [database connection] or the
        !          1286: ** same [prepared statement] in different threads at the same time.
        !          1287: ** ^If SQLite is compiled with
        !          1288: ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
        !          1289: ** it is not possible to set the Serialized [threading mode] and
        !          1290: ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
        !          1291: ** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
        !          1292: **
        !          1293: ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>
        !          1294: ** <dd> ^(This option takes a single argument which is a pointer to an
        !          1295: ** instance of the [sqlite3_mem_methods] structure.  The argument specifies
        !          1296: ** alternative low-level memory allocation routines to be used in place of
        !          1297: ** the memory allocation routines built into SQLite.)^ ^SQLite makes
        !          1298: ** its own private copy of the content of the [sqlite3_mem_methods] structure
        !          1299: ** before the [sqlite3_config()] call returns.</dd>
        !          1300: **
        !          1301: ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>
        !          1302: ** <dd> ^(This option takes a single argument which is a pointer to an
        !          1303: ** instance of the [sqlite3_mem_methods] structure.  The [sqlite3_mem_methods]
        !          1304: ** structure is filled with the currently defined memory allocation routines.)^
        !          1305: ** This option can be used to overload the default memory allocation
        !          1306: ** routines with a wrapper that simulations memory allocation failure or
        !          1307: ** tracks memory usage, for example. </dd>
        !          1308: **
        !          1309: ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
        !          1310: ** <dd> ^This option takes single argument of type int, interpreted as a 
        !          1311: ** boolean, which enables or disables the collection of memory allocation 
        !          1312: ** statistics. ^(When memory allocation statistics are disabled, the 
        !          1313: ** following SQLite interfaces become non-operational:
        !          1314: **   <ul>
        !          1315: **   <li> [sqlite3_memory_used()]
        !          1316: **   <li> [sqlite3_memory_highwater()]
        !          1317: **   <li> [sqlite3_soft_heap_limit64()]
        !          1318: **   <li> [sqlite3_status()]
        !          1319: **   </ul>)^
        !          1320: ** ^Memory allocation statistics are enabled by default unless SQLite is
        !          1321: ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
        !          1322: ** allocation statistics are disabled by default.
        !          1323: ** </dd>
        !          1324: **
        !          1325: ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>
        !          1326: ** <dd> ^This option specifies a static memory buffer that SQLite can use for
        !          1327: ** scratch memory.  There are three arguments:  A pointer an 8-byte
        !          1328: ** aligned memory buffer from which the scratch allocations will be
        !          1329: ** drawn, the size of each scratch allocation (sz),
        !          1330: ** and the maximum number of scratch allocations (N).  The sz
        !          1331: ** argument must be a multiple of 16.
        !          1332: ** The first argument must be a pointer to an 8-byte aligned buffer
        !          1333: ** of at least sz*N bytes of memory.
        !          1334: ** ^SQLite will use no more than two scratch buffers per thread.  So
        !          1335: ** N should be set to twice the expected maximum number of threads.
        !          1336: ** ^SQLite will never require a scratch buffer that is more than 6
        !          1337: ** times the database page size. ^If SQLite needs needs additional
        !          1338: ** scratch memory beyond what is provided by this configuration option, then 
        !          1339: ** [sqlite3_malloc()] will be used to obtain the memory needed.</dd>
        !          1340: **
        !          1341: ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
        !          1342: ** <dd> ^This option specifies a static memory buffer that SQLite can use for
        !          1343: ** the database page cache with the default page cache implementation.  
        !          1344: ** This configuration should not be used if an application-define page
        !          1345: ** cache implementation is loaded using the SQLITE_CONFIG_PCACHE option.
        !          1346: ** There are three arguments to this option: A pointer to 8-byte aligned
        !          1347: ** memory, the size of each page buffer (sz), and the number of pages (N).
        !          1348: ** The sz argument should be the size of the largest database page
        !          1349: ** (a power of two between 512 and 32768) plus a little extra for each
        !          1350: ** page header.  ^The page header size is 20 to 40 bytes depending on
        !          1351: ** the host architecture.  ^It is harmless, apart from the wasted memory,
        !          1352: ** to make sz a little too large.  The first
        !          1353: ** argument should point to an allocation of at least sz*N bytes of memory.
        !          1354: ** ^SQLite will use the memory provided by the first argument to satisfy its
        !          1355: ** memory needs for the first N pages that it adds to cache.  ^If additional
        !          1356: ** page cache memory is needed beyond what is provided by this option, then
        !          1357: ** SQLite goes to [sqlite3_malloc()] for the additional storage space.
        !          1358: ** The pointer in the first argument must
        !          1359: ** be aligned to an 8-byte boundary or subsequent behavior of SQLite
        !          1360: ** will be undefined.</dd>
        !          1361: **
        !          1362: ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
        !          1363: ** <dd> ^This option specifies a static memory buffer that SQLite will use
        !          1364: ** for all of its dynamic memory allocation needs beyond those provided
        !          1365: ** for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE].
        !          1366: ** There are three arguments: An 8-byte aligned pointer to the memory,
        !          1367: ** the number of bytes in the memory buffer, and the minimum allocation size.
        !          1368: ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
        !          1369: ** to using its default memory allocator (the system malloc() implementation),
        !          1370: ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC].  ^If the
        !          1371: ** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or
        !          1372: ** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory
        !          1373: ** allocator is engaged to handle all of SQLites memory allocation needs.
        !          1374: ** The first pointer (the memory pointer) must be aligned to an 8-byte
        !          1375: ** boundary or subsequent behavior of SQLite will be undefined.
        !          1376: ** The minimum allocation size is capped at 2^12. Reasonable values
        !          1377: ** for the minimum allocation size are 2^5 through 2^8.</dd>
        !          1378: **
        !          1379: ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
        !          1380: ** <dd> ^(This option takes a single argument which is a pointer to an
        !          1381: ** instance of the [sqlite3_mutex_methods] structure.  The argument specifies
        !          1382: ** alternative low-level mutex routines to be used in place
        !          1383: ** the mutex routines built into SQLite.)^  ^SQLite makes a copy of the
        !          1384: ** content of the [sqlite3_mutex_methods] structure before the call to
        !          1385: ** [sqlite3_config()] returns. ^If SQLite is compiled with
        !          1386: ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
        !          1387: ** the entire mutexing subsystem is omitted from the build and hence calls to
        !          1388: ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
        !          1389: ** return [SQLITE_ERROR].</dd>
        !          1390: **
        !          1391: ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>
        !          1392: ** <dd> ^(This option takes a single argument which is a pointer to an
        !          1393: ** instance of the [sqlite3_mutex_methods] structure.  The
        !          1394: ** [sqlite3_mutex_methods]
        !          1395: ** structure is filled with the currently defined mutex routines.)^
        !          1396: ** This option can be used to overload the default mutex allocation
        !          1397: ** routines with a wrapper used to track mutex usage for performance
        !          1398: ** profiling or testing, for example.   ^If SQLite is compiled with
        !          1399: ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
        !          1400: ** the entire mutexing subsystem is omitted from the build and hence calls to
        !          1401: ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
        !          1402: ** return [SQLITE_ERROR].</dd>
        !          1403: **
        !          1404: ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>
        !          1405: ** <dd> ^(This option takes two arguments that determine the default
        !          1406: ** memory allocation for the lookaside memory allocator on each
        !          1407: ** [database connection].  The first argument is the
        !          1408: ** size of each lookaside buffer slot and the second is the number of
        !          1409: ** slots allocated to each database connection.)^  ^(This option sets the
        !          1410: ** <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE]
        !          1411: ** verb to [sqlite3_db_config()] can be used to change the lookaside
        !          1412: ** configuration on individual connections.)^ </dd>
        !          1413: **
        !          1414: ** [[SQLITE_CONFIG_PCACHE]] <dt>SQLITE_CONFIG_PCACHE</dt>
        !          1415: ** <dd> ^(This option takes a single argument which is a pointer to
        !          1416: ** an [sqlite3_pcache_methods] object.  This object specifies the interface
        !          1417: ** to a custom page cache implementation.)^  ^SQLite makes a copy of the
        !          1418: ** object and uses it for page cache memory allocations.</dd>
        !          1419: **
        !          1420: ** [[SQLITE_CONFIG_GETPCACHE]] <dt>SQLITE_CONFIG_GETPCACHE</dt>
        !          1421: ** <dd> ^(This option takes a single argument which is a pointer to an
        !          1422: ** [sqlite3_pcache_methods] object.  SQLite copies of the current
        !          1423: ** page cache implementation into that object.)^ </dd>
        !          1424: **
        !          1425: ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
        !          1426: ** <dd> ^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
        !          1427: ** function with a call signature of void(*)(void*,int,const char*), 
        !          1428: ** and a pointer to void. ^If the function pointer is not NULL, it is
        !          1429: ** invoked by [sqlite3_log()] to process each logging event.  ^If the
        !          1430: ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.
        !          1431: ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is
        !          1432: ** passed through as the first parameter to the application-defined logger
        !          1433: ** function whenever that function is invoked.  ^The second parameter to
        !          1434: ** the logger function is a copy of the first parameter to the corresponding
        !          1435: ** [sqlite3_log()] call and is intended to be a [result code] or an
        !          1436: ** [extended result code].  ^The third parameter passed to the logger is
        !          1437: ** log message after formatting via [sqlite3_snprintf()].
        !          1438: ** The SQLite logging interface is not reentrant; the logger function
        !          1439: ** supplied by the application must not invoke any SQLite interface.
        !          1440: ** In a multi-threaded application, the application-defined logger
        !          1441: ** function must be threadsafe. </dd>
        !          1442: **
        !          1443: ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
        !          1444: ** <dd> This option takes a single argument of type int. If non-zero, then
        !          1445: ** URI handling is globally enabled. If the parameter is zero, then URI handling
        !          1446: ** is globally disabled. If URI handling is globally enabled, all filenames
        !          1447: ** passed to [sqlite3_open()], [sqlite3_open_v2()], [sqlite3_open16()] or
        !          1448: ** specified as part of [ATTACH] commands are interpreted as URIs, regardless
        !          1449: ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
        !          1450: ** connection is opened. If it is globally disabled, filenames are
        !          1451: ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
        !          1452: ** database connection is opened. By default, URI handling is globally
        !          1453: ** disabled. The default value may be changed by compiling with the
        !          1454: ** [SQLITE_USE_URI] symbol defined.
        !          1455: ** </dl>
        !          1456: */
        !          1457: #define SQLITE_CONFIG_SINGLETHREAD  1  /* nil */
        !          1458: #define SQLITE_CONFIG_MULTITHREAD   2  /* nil */
        !          1459: #define SQLITE_CONFIG_SERIALIZED    3  /* nil */
        !          1460: #define SQLITE_CONFIG_MALLOC        4  /* sqlite3_mem_methods* */
        !          1461: #define SQLITE_CONFIG_GETMALLOC     5  /* sqlite3_mem_methods* */
        !          1462: #define SQLITE_CONFIG_SCRATCH       6  /* void*, int sz, int N */
        !          1463: #define SQLITE_CONFIG_PAGECACHE     7  /* void*, int sz, int N */
        !          1464: #define SQLITE_CONFIG_HEAP          8  /* void*, int nByte, int min */
        !          1465: #define SQLITE_CONFIG_MEMSTATUS     9  /* boolean */
        !          1466: #define SQLITE_CONFIG_MUTEX        10  /* sqlite3_mutex_methods* */
        !          1467: #define SQLITE_CONFIG_GETMUTEX     11  /* sqlite3_mutex_methods* */
        !          1468: /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 
        !          1469: #define SQLITE_CONFIG_LOOKASIDE    13  /* int int */
        !          1470: #define SQLITE_CONFIG_PCACHE       14  /* sqlite3_pcache_methods* */
        !          1471: #define SQLITE_CONFIG_GETPCACHE    15  /* sqlite3_pcache_methods* */
        !          1472: #define SQLITE_CONFIG_LOG          16  /* xFunc, void* */
        !          1473: #define SQLITE_CONFIG_URI          17  /* int */
        !          1474: 
        !          1475: /*
        !          1476: ** CAPI3REF: Database Connection Configuration Options
        !          1477: **
        !          1478: ** These constants are the available integer configuration options that
        !          1479: ** can be passed as the second argument to the [sqlite3_db_config()] interface.
        !          1480: **
        !          1481: ** New configuration options may be added in future releases of SQLite.
        !          1482: ** Existing configuration options might be discontinued.  Applications
        !          1483: ** should check the return code from [sqlite3_db_config()] to make sure that
        !          1484: ** the call worked.  ^The [sqlite3_db_config()] interface will return a
        !          1485: ** non-zero [error code] if a discontinued or unsupported configuration option
        !          1486: ** is invoked.
        !          1487: **
        !          1488: ** <dl>
        !          1489: ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
        !          1490: ** <dd> ^This option takes three additional arguments that determine the 
        !          1491: ** [lookaside memory allocator] configuration for the [database connection].
        !          1492: ** ^The first argument (the third parameter to [sqlite3_db_config()] is a
        !          1493: ** pointer to a memory buffer to use for lookaside memory.
        !          1494: ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb
        !          1495: ** may be NULL in which case SQLite will allocate the
        !          1496: ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the
        !          1497: ** size of each lookaside buffer slot.  ^The third argument is the number of
        !          1498: ** slots.  The size of the buffer in the first argument must be greater than
        !          1499: ** or equal to the product of the second and third arguments.  The buffer
        !          1500: ** must be aligned to an 8-byte boundary.  ^If the second argument to
        !          1501: ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally
        !          1502: ** rounded down to the next smaller multiple of 8.  ^(The lookaside memory
        !          1503: ** configuration for a database connection can only be changed when that
        !          1504: ** connection is not currently using lookaside memory, or in other words
        !          1505: ** when the "current value" returned by
        !          1506: ** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero.
        !          1507: ** Any attempt to change the lookaside memory configuration when lookaside
        !          1508: ** memory is in use leaves the configuration unchanged and returns 
        !          1509: ** [SQLITE_BUSY].)^</dd>
        !          1510: **
        !          1511: ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt>
        !          1512: ** <dd> ^This option is used to enable or disable the enforcement of
        !          1513: ** [foreign key constraints].  There should be two additional arguments.
        !          1514: ** The first argument is an integer which is 0 to disable FK enforcement,
        !          1515: ** positive to enable FK enforcement or negative to leave FK enforcement
        !          1516: ** unchanged.  The second parameter is a pointer to an integer into which
        !          1517: ** is written 0 or 1 to indicate whether FK enforcement is off or on
        !          1518: ** following this call.  The second parameter may be a NULL pointer, in
        !          1519: ** which case the FK enforcement setting is not reported back. </dd>
        !          1520: **
        !          1521: ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt>
        !          1522: ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].
        !          1523: ** There should be two additional arguments.
        !          1524: ** The first argument is an integer which is 0 to disable triggers,
        !          1525: ** positive to enable triggers or negative to leave the setting unchanged.
        !          1526: ** The second parameter is a pointer to an integer into which
        !          1527: ** is written 0 or 1 to indicate whether triggers are disabled or enabled
        !          1528: ** following this call.  The second parameter may be a NULL pointer, in
        !          1529: ** which case the trigger setting is not reported back. </dd>
        !          1530: **
        !          1531: ** </dl>
        !          1532: */
        !          1533: #define SQLITE_DBCONFIG_LOOKASIDE       1001  /* void* int int */
        !          1534: #define SQLITE_DBCONFIG_ENABLE_FKEY     1002  /* int int* */
        !          1535: #define SQLITE_DBCONFIG_ENABLE_TRIGGER  1003  /* int int* */
        !          1536: 
        !          1537: 
        !          1538: /*
        !          1539: ** CAPI3REF: Enable Or Disable Extended Result Codes
        !          1540: **
        !          1541: ** ^The sqlite3_extended_result_codes() routine enables or disables the
        !          1542: ** [extended result codes] feature of SQLite. ^The extended result
        !          1543: ** codes are disabled by default for historical compatibility.
        !          1544: */
        !          1545: SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff);
        !          1546: 
        !          1547: /*
        !          1548: ** CAPI3REF: Last Insert Rowid
        !          1549: **
        !          1550: ** ^Each entry in an SQLite table has a unique 64-bit signed
        !          1551: ** integer key called the [ROWID | "rowid"]. ^The rowid is always available
        !          1552: ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
        !          1553: ** names are not also used by explicitly declared columns. ^If
        !          1554: ** the table has a column of type [INTEGER PRIMARY KEY] then that column
        !          1555: ** is another alias for the rowid.
        !          1556: **
        !          1557: ** ^This routine returns the [rowid] of the most recent
        !          1558: ** successful [INSERT] into the database from the [database connection]
        !          1559: ** in the first argument.  ^As of SQLite version 3.7.7, this routines
        !          1560: ** records the last insert rowid of both ordinary tables and [virtual tables].
        !          1561: ** ^If no successful [INSERT]s
        !          1562: ** have ever occurred on that database connection, zero is returned.
        !          1563: **
        !          1564: ** ^(If an [INSERT] occurs within a trigger or within a [virtual table]
        !          1565: ** method, then this routine will return the [rowid] of the inserted
        !          1566: ** row as long as the trigger or virtual table method is running.
        !          1567: ** But once the trigger or virtual table method ends, the value returned 
        !          1568: ** by this routine reverts to what it was before the trigger or virtual
        !          1569: ** table method began.)^
        !          1570: **
        !          1571: ** ^An [INSERT] that fails due to a constraint violation is not a
        !          1572: ** successful [INSERT] and does not change the value returned by this
        !          1573: ** routine.  ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
        !          1574: ** and INSERT OR ABORT make no changes to the return value of this
        !          1575: ** routine when their insertion fails.  ^(When INSERT OR REPLACE
        !          1576: ** encounters a constraint violation, it does not fail.  The
        !          1577: ** INSERT continues to completion after deleting rows that caused
        !          1578: ** the constraint problem so INSERT OR REPLACE will always change
        !          1579: ** the return value of this interface.)^
        !          1580: **
        !          1581: ** ^For the purposes of this routine, an [INSERT] is considered to
        !          1582: ** be successful even if it is subsequently rolled back.
        !          1583: **
        !          1584: ** This function is accessible to SQL statements via the
        !          1585: ** [last_insert_rowid() SQL function].
        !          1586: **
        !          1587: ** If a separate thread performs a new [INSERT] on the same
        !          1588: ** database connection while the [sqlite3_last_insert_rowid()]
        !          1589: ** function is running and thus changes the last insert [rowid],
        !          1590: ** then the value returned by [sqlite3_last_insert_rowid()] is
        !          1591: ** unpredictable and might not equal either the old or the new
        !          1592: ** last insert [rowid].
        !          1593: */
        !          1594: SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);
        !          1595: 
        !          1596: /*
        !          1597: ** CAPI3REF: Count The Number Of Rows Modified
        !          1598: **
        !          1599: ** ^This function returns the number of database rows that were changed
        !          1600: ** or inserted or deleted by the most recently completed SQL statement
        !          1601: ** on the [database connection] specified by the first parameter.
        !          1602: ** ^(Only changes that are directly specified by the [INSERT], [UPDATE],
        !          1603: ** or [DELETE] statement are counted.  Auxiliary changes caused by
        !          1604: ** triggers or [foreign key actions] are not counted.)^ Use the
        !          1605: ** [sqlite3_total_changes()] function to find the total number of changes
        !          1606: ** including changes caused by triggers and foreign key actions.
        !          1607: **
        !          1608: ** ^Changes to a view that are simulated by an [INSTEAD OF trigger]
        !          1609: ** are not counted.  Only real table changes are counted.
        !          1610: **
        !          1611: ** ^(A "row change" is a change to a single row of a single table
        !          1612: ** caused by an INSERT, DELETE, or UPDATE statement.  Rows that
        !          1613: ** are changed as side effects of [REPLACE] constraint resolution,
        !          1614: ** rollback, ABORT processing, [DROP TABLE], or by any other
        !          1615: ** mechanisms do not count as direct row changes.)^
        !          1616: **
        !          1617: ** A "trigger context" is a scope of execution that begins and
        !          1618: ** ends with the script of a [CREATE TRIGGER | trigger]. 
        !          1619: ** Most SQL statements are
        !          1620: ** evaluated outside of any trigger.  This is the "top level"
        !          1621: ** trigger context.  If a trigger fires from the top level, a
        !          1622: ** new trigger context is entered for the duration of that one
        !          1623: ** trigger.  Subtriggers create subcontexts for their duration.
        !          1624: **
        !          1625: ** ^Calling [sqlite3_exec()] or [sqlite3_step()] recursively does
        !          1626: ** not create a new trigger context.
        !          1627: **
        !          1628: ** ^This function returns the number of direct row changes in the
        !          1629: ** most recent INSERT, UPDATE, or DELETE statement within the same
        !          1630: ** trigger context.
        !          1631: **
        !          1632: ** ^Thus, when called from the top level, this function returns the
        !          1633: ** number of changes in the most recent INSERT, UPDATE, or DELETE
        !          1634: ** that also occurred at the top level.  ^(Within the body of a trigger,
        !          1635: ** the sqlite3_changes() interface can be called to find the number of
        !          1636: ** changes in the most recently completed INSERT, UPDATE, or DELETE
        !          1637: ** statement within the body of the same trigger.
        !          1638: ** However, the number returned does not include changes
        !          1639: ** caused by subtriggers since those have their own context.)^
        !          1640: **
        !          1641: ** See also the [sqlite3_total_changes()] interface, the
        !          1642: ** [count_changes pragma], and the [changes() SQL function].
        !          1643: **
        !          1644: ** If a separate thread makes changes on the same database connection
        !          1645: ** while [sqlite3_changes()] is running then the value returned
        !          1646: ** is unpredictable and not meaningful.
        !          1647: */
        !          1648: SQLITE_API int sqlite3_changes(sqlite3*);
        !          1649: 
        !          1650: /*
        !          1651: ** CAPI3REF: Total Number Of Rows Modified
        !          1652: **
        !          1653: ** ^This function returns the number of row changes caused by [INSERT],
        !          1654: ** [UPDATE] or [DELETE] statements since the [database connection] was opened.
        !          1655: ** ^(The count returned by sqlite3_total_changes() includes all changes
        !          1656: ** from all [CREATE TRIGGER | trigger] contexts and changes made by
        !          1657: ** [foreign key actions]. However,
        !          1658: ** the count does not include changes used to implement [REPLACE] constraints,
        !          1659: ** do rollbacks or ABORT processing, or [DROP TABLE] processing.  The
        !          1660: ** count does not include rows of views that fire an [INSTEAD OF trigger],
        !          1661: ** though if the INSTEAD OF trigger makes changes of its own, those changes 
        !          1662: ** are counted.)^
        !          1663: ** ^The sqlite3_total_changes() function counts the changes as soon as
        !          1664: ** the statement that makes them is completed (when the statement handle
        !          1665: ** is passed to [sqlite3_reset()] or [sqlite3_finalize()]).
        !          1666: **
        !          1667: ** See also the [sqlite3_changes()] interface, the
        !          1668: ** [count_changes pragma], and the [total_changes() SQL function].
        !          1669: **
        !          1670: ** If a separate thread makes changes on the same database connection
        !          1671: ** while [sqlite3_total_changes()] is running then the value
        !          1672: ** returned is unpredictable and not meaningful.
        !          1673: */
        !          1674: SQLITE_API int sqlite3_total_changes(sqlite3*);
        !          1675: 
        !          1676: /*
        !          1677: ** CAPI3REF: Interrupt A Long-Running Query
        !          1678: **
        !          1679: ** ^This function causes any pending database operation to abort and
        !          1680: ** return at its earliest opportunity. This routine is typically
        !          1681: ** called in response to a user action such as pressing "Cancel"
        !          1682: ** or Ctrl-C where the user wants a long query operation to halt
        !          1683: ** immediately.
        !          1684: **
        !          1685: ** ^It is safe to call this routine from a thread different from the
        !          1686: ** thread that is currently running the database operation.  But it
        !          1687: ** is not safe to call this routine with a [database connection] that
        !          1688: ** is closed or might close before sqlite3_interrupt() returns.
        !          1689: **
        !          1690: ** ^If an SQL operation is very nearly finished at the time when
        !          1691: ** sqlite3_interrupt() is called, then it might not have an opportunity
        !          1692: ** to be interrupted and might continue to completion.
        !          1693: **
        !          1694: ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
        !          1695: ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
        !          1696: ** that is inside an explicit transaction, then the entire transaction
        !          1697: ** will be rolled back automatically.
        !          1698: **
        !          1699: ** ^The sqlite3_interrupt(D) call is in effect until all currently running
        !          1700: ** SQL statements on [database connection] D complete.  ^Any new SQL statements
        !          1701: ** that are started after the sqlite3_interrupt() call and before the 
        !          1702: ** running statements reaches zero are interrupted as if they had been
        !          1703: ** running prior to the sqlite3_interrupt() call.  ^New SQL statements
        !          1704: ** that are started after the running statement count reaches zero are
        !          1705: ** not effected by the sqlite3_interrupt().
        !          1706: ** ^A call to sqlite3_interrupt(D) that occurs when there are no running
        !          1707: ** SQL statements is a no-op and has no effect on SQL statements
        !          1708: ** that are started after the sqlite3_interrupt() call returns.
        !          1709: **
        !          1710: ** If the database connection closes while [sqlite3_interrupt()]
        !          1711: ** is running then bad things will likely happen.
        !          1712: */
        !          1713: SQLITE_API void sqlite3_interrupt(sqlite3*);
        !          1714: 
        !          1715: /*
        !          1716: ** CAPI3REF: Determine If An SQL Statement Is Complete
        !          1717: **
        !          1718: ** These routines are useful during command-line input to determine if the
        !          1719: ** currently entered text seems to form a complete SQL statement or
        !          1720: ** if additional input is needed before sending the text into
        !          1721: ** SQLite for parsing.  ^These routines return 1 if the input string
        !          1722: ** appears to be a complete SQL statement.  ^A statement is judged to be
        !          1723: ** complete if it ends with a semicolon token and is not a prefix of a
        !          1724: ** well-formed CREATE TRIGGER statement.  ^Semicolons that are embedded within
        !          1725: ** string literals or quoted identifier names or comments are not
        !          1726: ** independent tokens (they are part of the token in which they are
        !          1727: ** embedded) and thus do not count as a statement terminator.  ^Whitespace
        !          1728: ** and comments that follow the final semicolon are ignored.
        !          1729: **
        !          1730: ** ^These routines return 0 if the statement is incomplete.  ^If a
        !          1731: ** memory allocation fails, then SQLITE_NOMEM is returned.
        !          1732: **
        !          1733: ** ^These routines do not parse the SQL statements thus
        !          1734: ** will not detect syntactically incorrect SQL.
        !          1735: **
        !          1736: ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 
        !          1737: ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
        !          1738: ** automatically by sqlite3_complete16().  If that initialization fails,
        !          1739: ** then the return value from sqlite3_complete16() will be non-zero
        !          1740: ** regardless of whether or not the input SQL is complete.)^
        !          1741: **
        !          1742: ** The input to [sqlite3_complete()] must be a zero-terminated
        !          1743: ** UTF-8 string.
        !          1744: **
        !          1745: ** The input to [sqlite3_complete16()] must be a zero-terminated
        !          1746: ** UTF-16 string in native byte order.
        !          1747: */
        !          1748: SQLITE_API int sqlite3_complete(const char *sql);
        !          1749: SQLITE_API int sqlite3_complete16(const void *sql);
        !          1750: 
        !          1751: /*
        !          1752: ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
        !          1753: **
        !          1754: ** ^This routine sets a callback function that might be invoked whenever
        !          1755: ** an attempt is made to open a database table that another thread
        !          1756: ** or process has locked.
        !          1757: **
        !          1758: ** ^If the busy callback is NULL, then [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]
        !          1759: ** is returned immediately upon encountering the lock.  ^If the busy callback
        !          1760: ** is not NULL, then the callback might be invoked with two arguments.
        !          1761: **
        !          1762: ** ^The first argument to the busy handler is a copy of the void* pointer which
        !          1763: ** is the third argument to sqlite3_busy_handler().  ^The second argument to
        !          1764: ** the busy handler callback is the number of times that the busy handler has
        !          1765: ** been invoked for this locking event.  ^If the
        !          1766: ** busy callback returns 0, then no additional attempts are made to
        !          1767: ** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned.
        !          1768: ** ^If the callback returns non-zero, then another attempt
        !          1769: ** is made to open the database for reading and the cycle repeats.
        !          1770: **
        !          1771: ** The presence of a busy handler does not guarantee that it will be invoked
        !          1772: ** when there is lock contention. ^If SQLite determines that invoking the busy
        !          1773: ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
        !          1774: ** or [SQLITE_IOERR_BLOCKED] instead of invoking the busy handler.
        !          1775: ** Consider a scenario where one process is holding a read lock that
        !          1776: ** it is trying to promote to a reserved lock and
        !          1777: ** a second process is holding a reserved lock that it is trying
        !          1778: ** to promote to an exclusive lock.  The first process cannot proceed
        !          1779: ** because it is blocked by the second and the second process cannot
        !          1780: ** proceed because it is blocked by the first.  If both processes
        !          1781: ** invoke the busy handlers, neither will make any progress.  Therefore,
        !          1782: ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
        !          1783: ** will induce the first process to release its read lock and allow
        !          1784: ** the second process to proceed.
        !          1785: **
        !          1786: ** ^The default busy callback is NULL.
        !          1787: **
        !          1788: ** ^The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED]
        !          1789: ** when SQLite is in the middle of a large transaction where all the
        !          1790: ** changes will not fit into the in-memory cache.  SQLite will
        !          1791: ** already hold a RESERVED lock on the database file, but it needs
        !          1792: ** to promote this lock to EXCLUSIVE so that it can spill cache
        !          1793: ** pages into the database file without harm to concurrent
        !          1794: ** readers.  ^If it is unable to promote the lock, then the in-memory
        !          1795: ** cache will be left in an inconsistent state and so the error
        !          1796: ** code is promoted from the relatively benign [SQLITE_BUSY] to
        !          1797: ** the more severe [SQLITE_IOERR_BLOCKED].  ^This error code promotion
        !          1798: ** forces an automatic rollback of the changes.  See the
        !          1799: ** <a href="/cvstrac/wiki?p=CorruptionFollowingBusyError">
        !          1800: ** CorruptionFollowingBusyError</a> wiki page for a discussion of why
        !          1801: ** this is important.
        !          1802: **
        !          1803: ** ^(There can only be a single busy handler defined for each
        !          1804: ** [database connection].  Setting a new busy handler clears any
        !          1805: ** previously set handler.)^  ^Note that calling [sqlite3_busy_timeout()]
        !          1806: ** will also set or clear the busy handler.
        !          1807: **
        !          1808: ** The busy callback should not take any actions which modify the
        !          1809: ** database connection that invoked the busy handler.  Any such actions
        !          1810: ** result in undefined behavior.
        !          1811: ** 
        !          1812: ** A busy handler must not close the database connection
        !          1813: ** or [prepared statement] that invoked the busy handler.
        !          1814: */
        !          1815: SQLITE_API int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*);
        !          1816: 
        !          1817: /*
        !          1818: ** CAPI3REF: Set A Busy Timeout
        !          1819: **
        !          1820: ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
        !          1821: ** for a specified amount of time when a table is locked.  ^The handler
        !          1822: ** will sleep multiple times until at least "ms" milliseconds of sleeping
        !          1823: ** have accumulated.  ^After at least "ms" milliseconds of sleeping,
        !          1824: ** the handler returns 0 which causes [sqlite3_step()] to return
        !          1825: ** [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED].
        !          1826: **
        !          1827: ** ^Calling this routine with an argument less than or equal to zero
        !          1828: ** turns off all busy handlers.
        !          1829: **
        !          1830: ** ^(There can only be a single busy handler for a particular
        !          1831: ** [database connection] any any given moment.  If another busy handler
        !          1832: ** was defined  (using [sqlite3_busy_handler()]) prior to calling
        !          1833: ** this routine, that other busy handler is cleared.)^
        !          1834: */
        !          1835: SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms);
        !          1836: 
        !          1837: /*
        !          1838: ** CAPI3REF: Convenience Routines For Running Queries
        !          1839: **
        !          1840: ** This is a legacy interface that is preserved for backwards compatibility.
        !          1841: ** Use of this interface is not recommended.
        !          1842: **
        !          1843: ** Definition: A <b>result table</b> is memory data structure created by the
        !          1844: ** [sqlite3_get_table()] interface.  A result table records the
        !          1845: ** complete query results from one or more queries.
        !          1846: **
        !          1847: ** The table conceptually has a number of rows and columns.  But
        !          1848: ** these numbers are not part of the result table itself.  These
        !          1849: ** numbers are obtained separately.  Let N be the number of rows
        !          1850: ** and M be the number of columns.
        !          1851: **
        !          1852: ** A result table is an array of pointers to zero-terminated UTF-8 strings.
        !          1853: ** There are (N+1)*M elements in the array.  The first M pointers point
        !          1854: ** to zero-terminated strings that  contain the names of the columns.
        !          1855: ** The remaining entries all point to query results.  NULL values result
        !          1856: ** in NULL pointers.  All other values are in their UTF-8 zero-terminated
        !          1857: ** string representation as returned by [sqlite3_column_text()].
        !          1858: **
        !          1859: ** A result table might consist of one or more memory allocations.
        !          1860: ** It is not safe to pass a result table directly to [sqlite3_free()].
        !          1861: ** A result table should be deallocated using [sqlite3_free_table()].
        !          1862: **
        !          1863: ** ^(As an example of the result table format, suppose a query result
        !          1864: ** is as follows:
        !          1865: **
        !          1866: ** <blockquote><pre>
        !          1867: **        Name        | Age
        !          1868: **        -----------------------
        !          1869: **        Alice       | 43
        !          1870: **        Bob         | 28
        !          1871: **        Cindy       | 21
        !          1872: ** </pre></blockquote>
        !          1873: **
        !          1874: ** There are two column (M==2) and three rows (N==3).  Thus the
        !          1875: ** result table has 8 entries.  Suppose the result table is stored
        !          1876: ** in an array names azResult.  Then azResult holds this content:
        !          1877: **
        !          1878: ** <blockquote><pre>
        !          1879: **        azResult&#91;0] = "Name";
        !          1880: **        azResult&#91;1] = "Age";
        !          1881: **        azResult&#91;2] = "Alice";
        !          1882: **        azResult&#91;3] = "43";
        !          1883: **        azResult&#91;4] = "Bob";
        !          1884: **        azResult&#91;5] = "28";
        !          1885: **        azResult&#91;6] = "Cindy";
        !          1886: **        azResult&#91;7] = "21";
        !          1887: ** </pre></blockquote>)^
        !          1888: **
        !          1889: ** ^The sqlite3_get_table() function evaluates one or more
        !          1890: ** semicolon-separated SQL statements in the zero-terminated UTF-8
        !          1891: ** string of its 2nd parameter and returns a result table to the
        !          1892: ** pointer given in its 3rd parameter.
        !          1893: **
        !          1894: ** After the application has finished with the result from sqlite3_get_table(),
        !          1895: ** it must pass the result table pointer to sqlite3_free_table() in order to
        !          1896: ** release the memory that was malloced.  Because of the way the
        !          1897: ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
        !          1898: ** function must not try to call [sqlite3_free()] directly.  Only
        !          1899: ** [sqlite3_free_table()] is able to release the memory properly and safely.
        !          1900: **
        !          1901: ** The sqlite3_get_table() interface is implemented as a wrapper around
        !          1902: ** [sqlite3_exec()].  The sqlite3_get_table() routine does not have access
        !          1903: ** to any internal data structures of SQLite.  It uses only the public
        !          1904: ** interface defined here.  As a consequence, errors that occur in the
        !          1905: ** wrapper layer outside of the internal [sqlite3_exec()] call are not
        !          1906: ** reflected in subsequent calls to [sqlite3_errcode()] or
        !          1907: ** [sqlite3_errmsg()].
        !          1908: */
        !          1909: SQLITE_API int sqlite3_get_table(
        !          1910:   sqlite3 *db,          /* An open database */
        !          1911:   const char *zSql,     /* SQL to be evaluated */
        !          1912:   char ***pazResult,    /* Results of the query */
        !          1913:   int *pnRow,           /* Number of result rows written here */
        !          1914:   int *pnColumn,        /* Number of result columns written here */
        !          1915:   char **pzErrmsg       /* Error msg written here */
        !          1916: );
        !          1917: SQLITE_API void sqlite3_free_table(char **result);
        !          1918: 
        !          1919: /*
        !          1920: ** CAPI3REF: Formatted String Printing Functions
        !          1921: **
        !          1922: ** These routines are work-alikes of the "printf()" family of functions
        !          1923: ** from the standard C library.
        !          1924: **
        !          1925: ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
        !          1926: ** results into memory obtained from [sqlite3_malloc()].
        !          1927: ** The strings returned by these two routines should be
        !          1928: ** released by [sqlite3_free()].  ^Both routines return a
        !          1929: ** NULL pointer if [sqlite3_malloc()] is unable to allocate enough
        !          1930: ** memory to hold the resulting string.
        !          1931: **
        !          1932: ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
        !          1933: ** the standard C library.  The result is written into the
        !          1934: ** buffer supplied as the second parameter whose size is given by
        !          1935: ** the first parameter. Note that the order of the
        !          1936: ** first two parameters is reversed from snprintf().)^  This is an
        !          1937: ** historical accident that cannot be fixed without breaking
        !          1938: ** backwards compatibility.  ^(Note also that sqlite3_snprintf()
        !          1939: ** returns a pointer to its buffer instead of the number of
        !          1940: ** characters actually written into the buffer.)^  We admit that
        !          1941: ** the number of characters written would be a more useful return
        !          1942: ** value but we cannot change the implementation of sqlite3_snprintf()
        !          1943: ** now without breaking compatibility.
        !          1944: **
        !          1945: ** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
        !          1946: ** guarantees that the buffer is always zero-terminated.  ^The first
        !          1947: ** parameter "n" is the total size of the buffer, including space for
        !          1948: ** the zero terminator.  So the longest string that can be completely
        !          1949: ** written will be n-1 characters.
        !          1950: **
        !          1951: ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
        !          1952: **
        !          1953: ** These routines all implement some additional formatting
        !          1954: ** options that are useful for constructing SQL statements.
        !          1955: ** All of the usual printf() formatting options apply.  In addition, there
        !          1956: ** is are "%q", "%Q", and "%z" options.
        !          1957: **
        !          1958: ** ^(The %q option works like %s in that it substitutes a null-terminated
        !          1959: ** string from the argument list.  But %q also doubles every '\'' character.
        !          1960: ** %q is designed for use inside a string literal.)^  By doubling each '\''
        !          1961: ** character it escapes that character and allows it to be inserted into
        !          1962: ** the string.
        !          1963: **
        !          1964: ** For example, assume the string variable zText contains text as follows:
        !          1965: **
        !          1966: ** <blockquote><pre>
        !          1967: **  char *zText = "It's a happy day!";
        !          1968: ** </pre></blockquote>
        !          1969: **
        !          1970: ** One can use this text in an SQL statement as follows:
        !          1971: **
        !          1972: ** <blockquote><pre>
        !          1973: **  char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText);
        !          1974: **  sqlite3_exec(db, zSQL, 0, 0, 0);
        !          1975: **  sqlite3_free(zSQL);
        !          1976: ** </pre></blockquote>
        !          1977: **
        !          1978: ** Because the %q format string is used, the '\'' character in zText
        !          1979: ** is escaped and the SQL generated is as follows:
        !          1980: **
        !          1981: ** <blockquote><pre>
        !          1982: **  INSERT INTO table1 VALUES('It''s a happy day!')
        !          1983: ** </pre></blockquote>
        !          1984: **
        !          1985: ** This is correct.  Had we used %s instead of %q, the generated SQL
        !          1986: ** would have looked like this:
        !          1987: **
        !          1988: ** <blockquote><pre>
        !          1989: **  INSERT INTO table1 VALUES('It's a happy day!');
        !          1990: ** </pre></blockquote>
        !          1991: **
        !          1992: ** This second example is an SQL syntax error.  As a general rule you should
        !          1993: ** always use %q instead of %s when inserting text into a string literal.
        !          1994: **
        !          1995: ** ^(The %Q option works like %q except it also adds single quotes around
        !          1996: ** the outside of the total string.  Additionally, if the parameter in the
        !          1997: ** argument list is a NULL pointer, %Q substitutes the text "NULL" (without
        !          1998: ** single quotes).)^  So, for example, one could say:
        !          1999: **
        !          2000: ** <blockquote><pre>
        !          2001: **  char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText);
        !          2002: **  sqlite3_exec(db, zSQL, 0, 0, 0);
        !          2003: **  sqlite3_free(zSQL);
        !          2004: ** </pre></blockquote>
        !          2005: **
        !          2006: ** The code above will render a correct SQL statement in the zSQL
        !          2007: ** variable even if the zText variable is a NULL pointer.
        !          2008: **
        !          2009: ** ^(The "%z" formatting option works like "%s" but with the
        !          2010: ** addition that after the string has been read and copied into
        !          2011: ** the result, [sqlite3_free()] is called on the input string.)^
        !          2012: */
        !          2013: SQLITE_API char *sqlite3_mprintf(const char*,...);
        !          2014: SQLITE_API char *sqlite3_vmprintf(const char*, va_list);
        !          2015: SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...);
        !          2016: SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list);
        !          2017: 
        !          2018: /*
        !          2019: ** CAPI3REF: Memory Allocation Subsystem
        !          2020: **
        !          2021: ** The SQLite core uses these three routines for all of its own
        !          2022: ** internal memory allocation needs. "Core" in the previous sentence
        !          2023: ** does not include operating-system specific VFS implementation.  The
        !          2024: ** Windows VFS uses native malloc() and free() for some operations.
        !          2025: **
        !          2026: ** ^The sqlite3_malloc() routine returns a pointer to a block
        !          2027: ** of memory at least N bytes in length, where N is the parameter.
        !          2028: ** ^If sqlite3_malloc() is unable to obtain sufficient free
        !          2029: ** memory, it returns a NULL pointer.  ^If the parameter N to
        !          2030: ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
        !          2031: ** a NULL pointer.
        !          2032: **
        !          2033: ** ^Calling sqlite3_free() with a pointer previously returned
        !          2034: ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
        !          2035: ** that it might be reused.  ^The sqlite3_free() routine is
        !          2036: ** a no-op if is called with a NULL pointer.  Passing a NULL pointer
        !          2037: ** to sqlite3_free() is harmless.  After being freed, memory
        !          2038: ** should neither be read nor written.  Even reading previously freed
        !          2039: ** memory might result in a segmentation fault or other severe error.
        !          2040: ** Memory corruption, a segmentation fault, or other severe error
        !          2041: ** might result if sqlite3_free() is called with a non-NULL pointer that
        !          2042: ** was not obtained from sqlite3_malloc() or sqlite3_realloc().
        !          2043: **
        !          2044: ** ^(The sqlite3_realloc() interface attempts to resize a
        !          2045: ** prior memory allocation to be at least N bytes, where N is the
        !          2046: ** second parameter.  The memory allocation to be resized is the first
        !          2047: ** parameter.)^ ^ If the first parameter to sqlite3_realloc()
        !          2048: ** is a NULL pointer then its behavior is identical to calling
        !          2049: ** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc().
        !          2050: ** ^If the second parameter to sqlite3_realloc() is zero or
        !          2051: ** negative then the behavior is exactly the same as calling
        !          2052: ** sqlite3_free(P) where P is the first parameter to sqlite3_realloc().
        !          2053: ** ^sqlite3_realloc() returns a pointer to a memory allocation
        !          2054: ** of at least N bytes in size or NULL if sufficient memory is unavailable.
        !          2055: ** ^If M is the size of the prior allocation, then min(N,M) bytes
        !          2056: ** of the prior allocation are copied into the beginning of buffer returned
        !          2057: ** by sqlite3_realloc() and the prior allocation is freed.
        !          2058: ** ^If sqlite3_realloc() returns NULL, then the prior allocation
        !          2059: ** is not freed.
        !          2060: **
        !          2061: ** ^The memory returned by sqlite3_malloc() and sqlite3_realloc()
        !          2062: ** is always aligned to at least an 8 byte boundary, or to a
        !          2063: ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
        !          2064: ** option is used.
        !          2065: **
        !          2066: ** In SQLite version 3.5.0 and 3.5.1, it was possible to define
        !          2067: ** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in
        !          2068: ** implementation of these routines to be omitted.  That capability
        !          2069: ** is no longer provided.  Only built-in memory allocators can be used.
        !          2070: **
        !          2071: ** The Windows OS interface layer calls
        !          2072: ** the system malloc() and free() directly when converting
        !          2073: ** filenames between the UTF-8 encoding used by SQLite
        !          2074: ** and whatever filename encoding is used by the particular Windows
        !          2075: ** installation.  Memory allocation errors are detected, but
        !          2076: ** they are reported back as [SQLITE_CANTOPEN] or
        !          2077: ** [SQLITE_IOERR] rather than [SQLITE_NOMEM].
        !          2078: **
        !          2079: ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
        !          2080: ** must be either NULL or else pointers obtained from a prior
        !          2081: ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
        !          2082: ** not yet been released.
        !          2083: **
        !          2084: ** The application must not read or write any part of
        !          2085: ** a block of memory after it has been released using
        !          2086: ** [sqlite3_free()] or [sqlite3_realloc()].
        !          2087: */
        !          2088: SQLITE_API void *sqlite3_malloc(int);
        !          2089: SQLITE_API void *sqlite3_realloc(void*, int);
        !          2090: SQLITE_API void sqlite3_free(void*);
        !          2091: 
        !          2092: /*
        !          2093: ** CAPI3REF: Memory Allocator Statistics
        !          2094: **
        !          2095: ** SQLite provides these two interfaces for reporting on the status
        !          2096: ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
        !          2097: ** routines, which form the built-in memory allocation subsystem.
        !          2098: **
        !          2099: ** ^The [sqlite3_memory_used()] routine returns the number of bytes
        !          2100: ** of memory currently outstanding (malloced but not freed).
        !          2101: ** ^The [sqlite3_memory_highwater()] routine returns the maximum
        !          2102: ** value of [sqlite3_memory_used()] since the high-water mark
        !          2103: ** was last reset.  ^The values returned by [sqlite3_memory_used()] and
        !          2104: ** [sqlite3_memory_highwater()] include any overhead
        !          2105: ** added by SQLite in its implementation of [sqlite3_malloc()],
        !          2106: ** but not overhead added by the any underlying system library
        !          2107: ** routines that [sqlite3_malloc()] may call.
        !          2108: **
        !          2109: ** ^The memory high-water mark is reset to the current value of
        !          2110: ** [sqlite3_memory_used()] if and only if the parameter to
        !          2111: ** [sqlite3_memory_highwater()] is true.  ^The value returned
        !          2112: ** by [sqlite3_memory_highwater(1)] is the high-water mark
        !          2113: ** prior to the reset.
        !          2114: */
        !          2115: SQLITE_API sqlite3_int64 sqlite3_memory_used(void);
        !          2116: SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag);
        !          2117: 
        !          2118: /*
        !          2119: ** CAPI3REF: Pseudo-Random Number Generator
        !          2120: **
        !          2121: ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
        !          2122: ** select random [ROWID | ROWIDs] when inserting new records into a table that
        !          2123: ** already uses the largest possible [ROWID].  The PRNG is also used for
        !          2124: ** the build-in random() and randomblob() SQL functions.  This interface allows
        !          2125: ** applications to access the same PRNG for other purposes.
        !          2126: **
        !          2127: ** ^A call to this routine stores N bytes of randomness into buffer P.
        !          2128: **
        !          2129: ** ^The first time this routine is invoked (either internally or by
        !          2130: ** the application) the PRNG is seeded using randomness obtained
        !          2131: ** from the xRandomness method of the default [sqlite3_vfs] object.
        !          2132: ** ^On all subsequent invocations, the pseudo-randomness is generated
        !          2133: ** internally and without recourse to the [sqlite3_vfs] xRandomness
        !          2134: ** method.
        !          2135: */
        !          2136: SQLITE_API void sqlite3_randomness(int N, void *P);
        !          2137: 
        !          2138: /*
        !          2139: ** CAPI3REF: Compile-Time Authorization Callbacks
        !          2140: **
        !          2141: ** ^This routine registers an authorizer callback with a particular
        !          2142: ** [database connection], supplied in the first argument.
        !          2143: ** ^The authorizer callback is invoked as SQL statements are being compiled
        !          2144: ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
        !          2145: ** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()].  ^At various
        !          2146: ** points during the compilation process, as logic is being created
        !          2147: ** to perform various actions, the authorizer callback is invoked to
        !          2148: ** see if those actions are allowed.  ^The authorizer callback should
        !          2149: ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
        !          2150: ** specific action but allow the SQL statement to continue to be
        !          2151: ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
        !          2152: ** rejected with an error.  ^If the authorizer callback returns
        !          2153: ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
        !          2154: ** then the [sqlite3_prepare_v2()] or equivalent call that triggered
        !          2155: ** the authorizer will fail with an error message.
        !          2156: **
        !          2157: ** When the callback returns [SQLITE_OK], that means the operation
        !          2158: ** requested is ok.  ^When the callback returns [SQLITE_DENY], the
        !          2159: ** [sqlite3_prepare_v2()] or equivalent call that triggered the
        !          2160: ** authorizer will fail with an error message explaining that
        !          2161: ** access is denied. 
        !          2162: **
        !          2163: ** ^The first parameter to the authorizer callback is a copy of the third
        !          2164: ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
        !          2165: ** to the callback is an integer [SQLITE_COPY | action code] that specifies
        !          2166: ** the particular action to be authorized. ^The third through sixth parameters
        !          2167: ** to the callback are zero-terminated strings that contain additional
        !          2168: ** details about the action to be authorized.
        !          2169: **
        !          2170: ** ^If the action code is [SQLITE_READ]
        !          2171: ** and the callback returns [SQLITE_IGNORE] then the
        !          2172: ** [prepared statement] statement is constructed to substitute
        !          2173: ** a NULL value in place of the table column that would have
        !          2174: ** been read if [SQLITE_OK] had been returned.  The [SQLITE_IGNORE]
        !          2175: ** return can be used to deny an untrusted user access to individual
        !          2176: ** columns of a table.
        !          2177: ** ^If the action code is [SQLITE_DELETE] and the callback returns
        !          2178: ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
        !          2179: ** [truncate optimization] is disabled and all rows are deleted individually.
        !          2180: **
        !          2181: ** An authorizer is used when [sqlite3_prepare | preparing]
        !          2182: ** SQL statements from an untrusted source, to ensure that the SQL statements
        !          2183: ** do not try to access data they are not allowed to see, or that they do not
        !          2184: ** try to execute malicious statements that damage the database.  For
        !          2185: ** example, an application may allow a user to enter arbitrary
        !          2186: ** SQL queries for evaluation by a database.  But the application does
        !          2187: ** not want the user to be able to make arbitrary changes to the
        !          2188: ** database.  An authorizer could then be put in place while the
        !          2189: ** user-entered SQL is being [sqlite3_prepare | prepared] that
        !          2190: ** disallows everything except [SELECT] statements.
        !          2191: **
        !          2192: ** Applications that need to process SQL from untrusted sources
        !          2193: ** might also consider lowering resource limits using [sqlite3_limit()]
        !          2194: ** and limiting database size using the [max_page_count] [PRAGMA]
        !          2195: ** in addition to using an authorizer.
        !          2196: **
        !          2197: ** ^(Only a single authorizer can be in place on a database connection
        !          2198: ** at a time.  Each call to sqlite3_set_authorizer overrides the
        !          2199: ** previous call.)^  ^Disable the authorizer by installing a NULL callback.
        !          2200: ** The authorizer is disabled by default.
        !          2201: **
        !          2202: ** The authorizer callback must not do anything that will modify
        !          2203: ** the database connection that invoked the authorizer callback.
        !          2204: ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
        !          2205: ** database connections for the meaning of "modify" in this paragraph.
        !          2206: **
        !          2207: ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
        !          2208: ** statement might be re-prepared during [sqlite3_step()] due to a 
        !          2209: ** schema change.  Hence, the application should ensure that the
        !          2210: ** correct authorizer callback remains in place during the [sqlite3_step()].
        !          2211: **
        !          2212: ** ^Note that the authorizer callback is invoked only during
        !          2213: ** [sqlite3_prepare()] or its variants.  Authorization is not
        !          2214: ** performed during statement evaluation in [sqlite3_step()], unless
        !          2215: ** as stated in the previous paragraph, sqlite3_step() invokes
        !          2216: ** sqlite3_prepare_v2() to reprepare a statement after a schema change.
        !          2217: */
        !          2218: SQLITE_API int sqlite3_set_authorizer(
        !          2219:   sqlite3*,
        !          2220:   int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
        !          2221:   void *pUserData
        !          2222: );
        !          2223: 
        !          2224: /*
        !          2225: ** CAPI3REF: Authorizer Return Codes
        !          2226: **
        !          2227: ** The [sqlite3_set_authorizer | authorizer callback function] must
        !          2228: ** return either [SQLITE_OK] or one of these two constants in order
        !          2229: ** to signal SQLite whether or not the action is permitted.  See the
        !          2230: ** [sqlite3_set_authorizer | authorizer documentation] for additional
        !          2231: ** information.
        !          2232: **
        !          2233: ** Note that SQLITE_IGNORE is also used as a [SQLITE_ROLLBACK | return code]
        !          2234: ** from the [sqlite3_vtab_on_conflict()] interface.
        !          2235: */
        !          2236: #define SQLITE_DENY   1   /* Abort the SQL statement with an error */
        !          2237: #define SQLITE_IGNORE 2   /* Don't allow access, but don't generate an error */
        !          2238: 
        !          2239: /*
        !          2240: ** CAPI3REF: Authorizer Action Codes
        !          2241: **
        !          2242: ** The [sqlite3_set_authorizer()] interface registers a callback function
        !          2243: ** that is invoked to authorize certain SQL statement actions.  The
        !          2244: ** second parameter to the callback is an integer code that specifies
        !          2245: ** what action is being authorized.  These are the integer action codes that
        !          2246: ** the authorizer callback may be passed.
        !          2247: **
        !          2248: ** These action code values signify what kind of operation is to be
        !          2249: ** authorized.  The 3rd and 4th parameters to the authorization
        !          2250: ** callback function will be parameters or NULL depending on which of these
        !          2251: ** codes is used as the second parameter.  ^(The 5th parameter to the
        !          2252: ** authorizer callback is the name of the database ("main", "temp",
        !          2253: ** etc.) if applicable.)^  ^The 6th parameter to the authorizer callback
        !          2254: ** is the name of the inner-most trigger or view that is responsible for
        !          2255: ** the access attempt or NULL if this access attempt is directly from
        !          2256: ** top-level SQL code.
        !          2257: */
        !          2258: /******************************************* 3rd ************ 4th ***********/
        !          2259: #define SQLITE_CREATE_INDEX          1   /* Index Name      Table Name      */
        !          2260: #define SQLITE_CREATE_TABLE          2   /* Table Name      NULL            */
        !          2261: #define SQLITE_CREATE_TEMP_INDEX     3   /* Index Name      Table Name      */
        !          2262: #define SQLITE_CREATE_TEMP_TABLE     4   /* Table Name      NULL            */
        !          2263: #define SQLITE_CREATE_TEMP_TRIGGER   5   /* Trigger Name    Table Name      */
        !          2264: #define SQLITE_CREATE_TEMP_VIEW      6   /* View Name       NULL            */
        !          2265: #define SQLITE_CREATE_TRIGGER        7   /* Trigger Name    Table Name      */
        !          2266: #define SQLITE_CREATE_VIEW           8   /* View Name       NULL            */
        !          2267: #define SQLITE_DELETE                9   /* Table Name      NULL            */
        !          2268: #define SQLITE_DROP_INDEX           10   /* Index Name      Table Name      */
        !          2269: #define SQLITE_DROP_TABLE           11   /* Table Name      NULL            */
        !          2270: #define SQLITE_DROP_TEMP_INDEX      12   /* Index Name      Table Name      */
        !          2271: #define SQLITE_DROP_TEMP_TABLE      13   /* Table Name      NULL            */
        !          2272: #define SQLITE_DROP_TEMP_TRIGGER    14   /* Trigger Name    Table Name      */
        !          2273: #define SQLITE_DROP_TEMP_VIEW       15   /* View Name       NULL            */
        !          2274: #define SQLITE_DROP_TRIGGER         16   /* Trigger Name    Table Name      */
        !          2275: #define SQLITE_DROP_VIEW            17   /* View Name       NULL            */
        !          2276: #define SQLITE_INSERT               18   /* Table Name      NULL            */
        !          2277: #define SQLITE_PRAGMA               19   /* Pragma Name     1st arg or NULL */
        !          2278: #define SQLITE_READ                 20   /* Table Name      Column Name     */
        !          2279: #define SQLITE_SELECT               21   /* NULL            NULL            */
        !          2280: #define SQLITE_TRANSACTION          22   /* Operation       NULL            */
        !          2281: #define SQLITE_UPDATE               23   /* Table Name      Column Name     */
        !          2282: #define SQLITE_ATTACH               24   /* Filename        NULL            */
        !          2283: #define SQLITE_DETACH               25   /* Database Name   NULL            */
        !          2284: #define SQLITE_ALTER_TABLE          26   /* Database Name   Table Name      */
        !          2285: #define SQLITE_REINDEX              27   /* Index Name      NULL            */
        !          2286: #define SQLITE_ANALYZE              28   /* Table Name      NULL            */
        !          2287: #define SQLITE_CREATE_VTABLE        29   /* Table Name      Module Name     */
        !          2288: #define SQLITE_DROP_VTABLE          30   /* Table Name      Module Name     */
        !          2289: #define SQLITE_FUNCTION             31   /* NULL            Function Name   */
        !          2290: #define SQLITE_SAVEPOINT            32   /* Operation       Savepoint Name  */
        !          2291: #define SQLITE_COPY                  0   /* No longer used */
        !          2292: 
        !          2293: /*
        !          2294: ** CAPI3REF: Tracing And Profiling Functions
        !          2295: **
        !          2296: ** These routines register callback functions that can be used for
        !          2297: ** tracing and profiling the execution of SQL statements.
        !          2298: **
        !          2299: ** ^The callback function registered by sqlite3_trace() is invoked at
        !          2300: ** various times when an SQL statement is being run by [sqlite3_step()].
        !          2301: ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
        !          2302: ** SQL statement text as the statement first begins executing.
        !          2303: ** ^(Additional sqlite3_trace() callbacks might occur
        !          2304: ** as each triggered subprogram is entered.  The callbacks for triggers
        !          2305: ** contain a UTF-8 SQL comment that identifies the trigger.)^
        !          2306: **
        !          2307: ** ^The callback function registered by sqlite3_profile() is invoked
        !          2308: ** as each SQL statement finishes.  ^The profile callback contains
        !          2309: ** the original statement text and an estimate of wall-clock time
        !          2310: ** of how long that statement took to run.  ^The profile callback
        !          2311: ** time is in units of nanoseconds, however the current implementation
        !          2312: ** is only capable of millisecond resolution so the six least significant
        !          2313: ** digits in the time are meaningless.  Future versions of SQLite
        !          2314: ** might provide greater resolution on the profiler callback.  The
        !          2315: ** sqlite3_profile() function is considered experimental and is
        !          2316: ** subject to change in future versions of SQLite.
        !          2317: */
        !          2318: SQLITE_API void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*);
        !          2319: SQLITE_API SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*,
        !          2320:    void(*xProfile)(void*,const char*,sqlite3_uint64), void*);
        !          2321: 
        !          2322: /*
        !          2323: ** CAPI3REF: Query Progress Callbacks
        !          2324: **
        !          2325: ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
        !          2326: ** function X to be invoked periodically during long running calls to
        !          2327: ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for
        !          2328: ** database connection D.  An example use for this
        !          2329: ** interface is to keep a GUI updated during a large query.
        !          2330: **
        !          2331: ** ^The parameter P is passed through as the only parameter to the 
        !          2332: ** callback function X.  ^The parameter N is the number of 
        !          2333: ** [virtual machine instructions] that are evaluated between successive
        !          2334: ** invocations of the callback X.
        !          2335: **
        !          2336: ** ^Only a single progress handler may be defined at one time per
        !          2337: ** [database connection]; setting a new progress handler cancels the
        !          2338: ** old one.  ^Setting parameter X to NULL disables the progress handler.
        !          2339: ** ^The progress handler is also disabled by setting N to a value less
        !          2340: ** than 1.
        !          2341: **
        !          2342: ** ^If the progress callback returns non-zero, the operation is
        !          2343: ** interrupted.  This feature can be used to implement a
        !          2344: ** "Cancel" button on a GUI progress dialog box.
        !          2345: **
        !          2346: ** The progress handler callback must not do anything that will modify
        !          2347: ** the database connection that invoked the progress handler.
        !          2348: ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
        !          2349: ** database connections for the meaning of "modify" in this paragraph.
        !          2350: **
        !          2351: */
        !          2352: SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
        !          2353: 
        !          2354: /*
        !          2355: ** CAPI3REF: Opening A New Database Connection
        !          2356: **
        !          2357: ** ^These routines open an SQLite database file as specified by the 
        !          2358: ** filename argument. ^The filename argument is interpreted as UTF-8 for
        !          2359: ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
        !          2360: ** order for sqlite3_open16(). ^(A [database connection] handle is usually
        !          2361: ** returned in *ppDb, even if an error occurs.  The only exception is that
        !          2362: ** if SQLite is unable to allocate memory to hold the [sqlite3] object,
        !          2363: ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
        !          2364: ** object.)^ ^(If the database is opened (and/or created) successfully, then
        !          2365: ** [SQLITE_OK] is returned.  Otherwise an [error code] is returned.)^ ^The
        !          2366: ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
        !          2367: ** an English language description of the error following a failure of any
        !          2368: ** of the sqlite3_open() routines.
        !          2369: **
        !          2370: ** ^The default encoding for the database will be UTF-8 if
        !          2371: ** sqlite3_open() or sqlite3_open_v2() is called and
        !          2372: ** UTF-16 in the native byte order if sqlite3_open16() is used.
        !          2373: **
        !          2374: ** Whether or not an error occurs when it is opened, resources
        !          2375: ** associated with the [database connection] handle should be released by
        !          2376: ** passing it to [sqlite3_close()] when it is no longer required.
        !          2377: **
        !          2378: ** The sqlite3_open_v2() interface works like sqlite3_open()
        !          2379: ** except that it accepts two additional parameters for additional control
        !          2380: ** over the new database connection.  ^(The flags parameter to
        !          2381: ** sqlite3_open_v2() can take one of
        !          2382: ** the following three values, optionally combined with the 
        !          2383: ** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE],
        !          2384: ** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^
        !          2385: **
        !          2386: ** <dl>
        !          2387: ** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
        !          2388: ** <dd>The database is opened in read-only mode.  If the database does not
        !          2389: ** already exist, an error is returned.</dd>)^
        !          2390: **
        !          2391: ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
        !          2392: ** <dd>The database is opened for reading and writing if possible, or reading
        !          2393: ** only if the file is write protected by the operating system.  In either
        !          2394: ** case the database must already exist, otherwise an error is returned.</dd>)^
        !          2395: **
        !          2396: ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
        !          2397: ** <dd>The database is opened for reading and writing, and is created if
        !          2398: ** it does not already exist. This is the behavior that is always used for
        !          2399: ** sqlite3_open() and sqlite3_open16().</dd>)^
        !          2400: ** </dl>
        !          2401: **
        !          2402: ** If the 3rd parameter to sqlite3_open_v2() is not one of the
        !          2403: ** combinations shown above optionally combined with other
        !          2404: ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits]
        !          2405: ** then the behavior is undefined.
        !          2406: **
        !          2407: ** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection
        !          2408: ** opens in the multi-thread [threading mode] as long as the single-thread
        !          2409: ** mode has not been set at compile-time or start-time.  ^If the
        !          2410: ** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens
        !          2411: ** in the serialized [threading mode] unless single-thread was
        !          2412: ** previously selected at compile-time or start-time.
        !          2413: ** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be
        !          2414: ** eligible to use [shared cache mode], regardless of whether or not shared
        !          2415: ** cache is enabled using [sqlite3_enable_shared_cache()].  ^The
        !          2416: ** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not
        !          2417: ** participate in [shared cache mode] even if it is enabled.
        !          2418: **
        !          2419: ** ^The fourth parameter to sqlite3_open_v2() is the name of the
        !          2420: ** [sqlite3_vfs] object that defines the operating system interface that
        !          2421: ** the new database connection should use.  ^If the fourth parameter is
        !          2422: ** a NULL pointer then the default [sqlite3_vfs] object is used.
        !          2423: **
        !          2424: ** ^If the filename is ":memory:", then a private, temporary in-memory database
        !          2425: ** is created for the connection.  ^This in-memory database will vanish when
        !          2426: ** the database connection is closed.  Future versions of SQLite might
        !          2427: ** make use of additional special filenames that begin with the ":" character.
        !          2428: ** It is recommended that when a database filename actually does begin with
        !          2429: ** a ":" character you should prefix the filename with a pathname such as
        !          2430: ** "./" to avoid ambiguity.
        !          2431: **
        !          2432: ** ^If the filename is an empty string, then a private, temporary
        !          2433: ** on-disk database will be created.  ^This private database will be
        !          2434: ** automatically deleted as soon as the database connection is closed.
        !          2435: **
        !          2436: ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3>
        !          2437: **
        !          2438: ** ^If [URI filename] interpretation is enabled, and the filename argument
        !          2439: ** begins with "file:", then the filename is interpreted as a URI. ^URI
        !          2440: ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is
        !          2441: ** set in the fourth argument to sqlite3_open_v2(), or if it has
        !          2442: ** been enabled globally using the [SQLITE_CONFIG_URI] option with the
        !          2443: ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option.
        !          2444: ** As of SQLite version 3.7.7, URI filename interpretation is turned off
        !          2445: ** by default, but future releases of SQLite might enable URI filename
        !          2446: ** interpretation by default.  See "[URI filenames]" for additional
        !          2447: ** information.
        !          2448: **
        !          2449: ** URI filenames are parsed according to RFC 3986. ^If the URI contains an
        !          2450: ** authority, then it must be either an empty string or the string 
        !          2451: ** "localhost". ^If the authority is not an empty string or "localhost", an 
        !          2452: ** error is returned to the caller. ^The fragment component of a URI, if 
        !          2453: ** present, is ignored.
        !          2454: **
        !          2455: ** ^SQLite uses the path component of the URI as the name of the disk file
        !          2456: ** which contains the database. ^If the path begins with a '/' character, 
        !          2457: ** then it is interpreted as an absolute path. ^If the path does not begin 
        !          2458: ** with a '/' (meaning that the authority section is omitted from the URI)
        !          2459: ** then the path is interpreted as a relative path. 
        !          2460: ** ^On windows, the first component of an absolute path 
        !          2461: ** is a drive specification (e.g. "C:").
        !          2462: **
        !          2463: ** [[core URI query parameters]]
        !          2464: ** The query component of a URI may contain parameters that are interpreted
        !          2465: ** either by SQLite itself, or by a [VFS | custom VFS implementation].
        !          2466: ** SQLite interprets the following three query parameters:
        !          2467: **
        !          2468: ** <ul>
        !          2469: **   <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
        !          2470: **     a VFS object that provides the operating system interface that should
        !          2471: **     be used to access the database file on disk. ^If this option is set to
        !          2472: **     an empty string the default VFS object is used. ^Specifying an unknown
        !          2473: **     VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is
        !          2474: **     present, then the VFS specified by the option takes precedence over
        !          2475: **     the value passed as the fourth parameter to sqlite3_open_v2().
        !          2476: **
        !          2477: **   <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw" or
        !          2478: **     "rwc". Attempting to set it to any other value is an error)^. 
        !          2479: **     ^If "ro" is specified, then the database is opened for read-only 
        !          2480: **     access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 
        !          2481: **     third argument to sqlite3_prepare_v2(). ^If the mode option is set to 
        !          2482: **     "rw", then the database is opened for read-write (but not create) 
        !          2483: **     access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 
        !          2484: **     been set. ^Value "rwc" is equivalent to setting both 
        !          2485: **     SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If sqlite3_open_v2() is 
        !          2486: **     used, it is an error to specify a value for the mode parameter that is 
        !          2487: **     less restrictive than that specified by the flags passed as the third 
        !          2488: **     parameter.
        !          2489: **
        !          2490: **   <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or
        !          2491: **     "private". ^Setting it to "shared" is equivalent to setting the
        !          2492: **     SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to
        !          2493: **     sqlite3_open_v2(). ^Setting the cache parameter to "private" is 
        !          2494: **     equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
        !          2495: **     ^If sqlite3_open_v2() is used and the "cache" parameter is present in
        !          2496: **     a URI filename, its value overrides any behaviour requested by setting
        !          2497: **     SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
        !          2498: ** </ul>
        !          2499: **
        !          2500: ** ^Specifying an unknown parameter in the query component of a URI is not an
        !          2501: ** error.  Future versions of SQLite might understand additional query
        !          2502: ** parameters.  See "[query parameters with special meaning to SQLite]" for
        !          2503: ** additional information.
        !          2504: **
        !          2505: ** [[URI filename examples]] <h3>URI filename examples</h3>
        !          2506: **
        !          2507: ** <table border="1" align=center cellpadding=5>
        !          2508: ** <tr><th> URI filenames <th> Results
        !          2509: ** <tr><td> file:data.db <td> 
        !          2510: **          Open the file "data.db" in the current directory.
        !          2511: ** <tr><td> file:/home/fred/data.db<br>
        !          2512: **          file:///home/fred/data.db <br> 
        !          2513: **          file://localhost/home/fred/data.db <br> <td> 
        !          2514: **          Open the database file "/home/fred/data.db".
        !          2515: ** <tr><td> file://darkstar/home/fred/data.db <td> 
        !          2516: **          An error. "darkstar" is not a recognized authority.
        !          2517: ** <tr><td style="white-space:nowrap"> 
        !          2518: **          file:///C:/Documents%20and%20Settings/fred/Desktop/data.db
        !          2519: **     <td> Windows only: Open the file "data.db" on fred's desktop on drive
        !          2520: **          C:. Note that the %20 escaping in this example is not strictly 
        !          2521: **          necessary - space characters can be used literally
        !          2522: **          in URI filenames.
        !          2523: ** <tr><td> file:data.db?mode=ro&cache=private <td> 
        !          2524: **          Open file "data.db" in the current directory for read-only access.
        !          2525: **          Regardless of whether or not shared-cache mode is enabled by
        !          2526: **          default, use a private cache.
        !          2527: ** <tr><td> file:/home/fred/data.db?vfs=unix-nolock <td>
        !          2528: **          Open file "/home/fred/data.db". Use the special VFS "unix-nolock".
        !          2529: ** <tr><td> file:data.db?mode=readonly <td> 
        !          2530: **          An error. "readonly" is not a valid option for the "mode" parameter.
        !          2531: ** </table>
        !          2532: **
        !          2533: ** ^URI hexadecimal escape sequences (%HH) are supported within the path and
        !          2534: ** query components of a URI. A hexadecimal escape sequence consists of a
        !          2535: ** percent sign - "%" - followed by exactly two hexadecimal digits 
        !          2536: ** specifying an octet value. ^Before the path or query components of a
        !          2537: ** URI filename are interpreted, they are encoded using UTF-8 and all 
        !          2538: ** hexadecimal escape sequences replaced by a single byte containing the
        !          2539: ** corresponding octet. If this process generates an invalid UTF-8 encoding,
        !          2540: ** the results are undefined.
        !          2541: **
        !          2542: ** <b>Note to Windows users:</b>  The encoding used for the filename argument
        !          2543: ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
        !          2544: ** codepage is currently defined.  Filenames containing international
        !          2545: ** characters must be converted to UTF-8 prior to passing them into
        !          2546: ** sqlite3_open() or sqlite3_open_v2().
        !          2547: */
        !          2548: SQLITE_API int sqlite3_open(
        !          2549:   const char *filename,   /* Database filename (UTF-8) */
        !          2550:   sqlite3 **ppDb          /* OUT: SQLite db handle */
        !          2551: );
        !          2552: SQLITE_API int sqlite3_open16(
        !          2553:   const void *filename,   /* Database filename (UTF-16) */
        !          2554:   sqlite3 **ppDb          /* OUT: SQLite db handle */
        !          2555: );
        !          2556: SQLITE_API int sqlite3_open_v2(
        !          2557:   const char *filename,   /* Database filename (UTF-8) */
        !          2558:   sqlite3 **ppDb,         /* OUT: SQLite db handle */
        !          2559:   int flags,              /* Flags */
        !          2560:   const char *zVfs        /* Name of VFS module to use */
        !          2561: );
        !          2562: 
        !          2563: /*
        !          2564: ** CAPI3REF: Obtain Values For URI Parameters
        !          2565: **
        !          2566: ** This is a utility routine, useful to VFS implementations, that checks
        !          2567: ** to see if a database file was a URI that contained a specific query 
        !          2568: ** parameter, and if so obtains the value of the query parameter.
        !          2569: **
        !          2570: ** The zFilename argument is the filename pointer passed into the xOpen()
        !          2571: ** method of a VFS implementation.  The zParam argument is the name of the
        !          2572: ** query parameter we seek.  This routine returns the value of the zParam
        !          2573: ** parameter if it exists.  If the parameter does not exist, this routine
        !          2574: ** returns a NULL pointer.
        !          2575: **
        !          2576: ** If the zFilename argument to this function is not a pointer that SQLite
        !          2577: ** passed into the xOpen VFS method, then the behavior of this routine
        !          2578: ** is undefined and probably undesirable.
        !          2579: */
        !          2580: SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam);
        !          2581: 
        !          2582: 
        !          2583: /*
        !          2584: ** CAPI3REF: Error Codes And Messages
        !          2585: **
        !          2586: ** ^The sqlite3_errcode() interface returns the numeric [result code] or
        !          2587: ** [extended result code] for the most recent failed sqlite3_* API call
        !          2588: ** associated with a [database connection]. If a prior API call failed
        !          2589: ** but the most recent API call succeeded, the return value from
        !          2590: ** sqlite3_errcode() is undefined.  ^The sqlite3_extended_errcode()
        !          2591: ** interface is the same except that it always returns the 
        !          2592: ** [extended result code] even when extended result codes are
        !          2593: ** disabled.
        !          2594: **
        !          2595: ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
        !          2596: ** text that describes the error, as either UTF-8 or UTF-16 respectively.
        !          2597: ** ^(Memory to hold the error message string is managed internally.
        !          2598: ** The application does not need to worry about freeing the result.
        !          2599: ** However, the error string might be overwritten or deallocated by
        !          2600: ** subsequent calls to other SQLite interface functions.)^
        !          2601: **
        !          2602: ** When the serialized [threading mode] is in use, it might be the
        !          2603: ** case that a second error occurs on a separate thread in between
        !          2604: ** the time of the first error and the call to these interfaces.
        !          2605: ** When that happens, the second error will be reported since these
        !          2606: ** interfaces always report the most recent result.  To avoid
        !          2607: ** this, each thread can obtain exclusive use of the [database connection] D
        !          2608: ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
        !          2609: ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
        !          2610: ** all calls to the interfaces listed here are completed.
        !          2611: **
        !          2612: ** If an interface fails with SQLITE_MISUSE, that means the interface
        !          2613: ** was invoked incorrectly by the application.  In that case, the
        !          2614: ** error code and message may or may not be set.
        !          2615: */
        !          2616: SQLITE_API int sqlite3_errcode(sqlite3 *db);
        !          2617: SQLITE_API int sqlite3_extended_errcode(sqlite3 *db);
        !          2618: SQLITE_API const char *sqlite3_errmsg(sqlite3*);
        !          2619: SQLITE_API const void *sqlite3_errmsg16(sqlite3*);
        !          2620: 
        !          2621: /*
        !          2622: ** CAPI3REF: SQL Statement Object
        !          2623: ** KEYWORDS: {prepared statement} {prepared statements}
        !          2624: **
        !          2625: ** An instance of this object represents a single SQL statement.
        !          2626: ** This object is variously known as a "prepared statement" or a
        !          2627: ** "compiled SQL statement" or simply as a "statement".
        !          2628: **
        !          2629: ** The life of a statement object goes something like this:
        !          2630: **
        !          2631: ** <ol>
        !          2632: ** <li> Create the object using [sqlite3_prepare_v2()] or a related
        !          2633: **      function.
        !          2634: ** <li> Bind values to [host parameters] using the sqlite3_bind_*()
        !          2635: **      interfaces.
        !          2636: ** <li> Run the SQL by calling [sqlite3_step()] one or more times.
        !          2637: ** <li> Reset the statement using [sqlite3_reset()] then go back
        !          2638: **      to step 2.  Do this zero or more times.
        !          2639: ** <li> Destroy the object using [sqlite3_finalize()].
        !          2640: ** </ol>
        !          2641: **
        !          2642: ** Refer to documentation on individual methods above for additional
        !          2643: ** information.
        !          2644: */
        !          2645: typedef struct sqlite3_stmt sqlite3_stmt;
        !          2646: 
        !          2647: /*
        !          2648: ** CAPI3REF: Run-time Limits
        !          2649: **
        !          2650: ** ^(This interface allows the size of various constructs to be limited
        !          2651: ** on a connection by connection basis.  The first parameter is the
        !          2652: ** [database connection] whose limit is to be set or queried.  The
        !          2653: ** second parameter is one of the [limit categories] that define a
        !          2654: ** class of constructs to be size limited.  The third parameter is the
        !          2655: ** new limit for that construct.)^
        !          2656: **
        !          2657: ** ^If the new limit is a negative number, the limit is unchanged.
        !          2658: ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 
        !          2659: ** [limits | hard upper bound]
        !          2660: ** set at compile-time by a C preprocessor macro called
        !          2661: ** [limits | SQLITE_MAX_<i>NAME</i>].
        !          2662: ** (The "_LIMIT_" in the name is changed to "_MAX_".))^
        !          2663: ** ^Attempts to increase a limit above its hard upper bound are
        !          2664: ** silently truncated to the hard upper bound.
        !          2665: **
        !          2666: ** ^Regardless of whether or not the limit was changed, the 
        !          2667: ** [sqlite3_limit()] interface returns the prior value of the limit.
        !          2668: ** ^Hence, to find the current value of a limit without changing it,
        !          2669: ** simply invoke this interface with the third parameter set to -1.
        !          2670: **
        !          2671: ** Run-time limits are intended for use in applications that manage
        !          2672: ** both their own internal database and also databases that are controlled
        !          2673: ** by untrusted external sources.  An example application might be a
        !          2674: ** web browser that has its own databases for storing history and
        !          2675: ** separate databases controlled by JavaScript applications downloaded
        !          2676: ** off the Internet.  The internal databases can be given the
        !          2677: ** large, default limits.  Databases managed by external sources can
        !          2678: ** be given much smaller limits designed to prevent a denial of service
        !          2679: ** attack.  Developers might also want to use the [sqlite3_set_authorizer()]
        !          2680: ** interface to further control untrusted SQL.  The size of the database
        !          2681: ** created by an untrusted script can be contained using the
        !          2682: ** [max_page_count] [PRAGMA].
        !          2683: **
        !          2684: ** New run-time limit categories may be added in future releases.
        !          2685: */
        !          2686: SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
        !          2687: 
        !          2688: /*
        !          2689: ** CAPI3REF: Run-Time Limit Categories
        !          2690: ** KEYWORDS: {limit category} {*limit categories}
        !          2691: **
        !          2692: ** These constants define various performance limits
        !          2693: ** that can be lowered at run-time using [sqlite3_limit()].
        !          2694: ** The synopsis of the meanings of the various limits is shown below.
        !          2695: ** Additional information is available at [limits | Limits in SQLite].
        !          2696: **
        !          2697: ** <dl>
        !          2698: ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt>
        !          2699: ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
        !          2700: **
        !          2701: ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
        !          2702: ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^
        !          2703: **
        !          2704: ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt>
        !          2705: ** <dd>The maximum number of columns in a table definition or in the
        !          2706: ** result set of a [SELECT] or the maximum number of columns in an index
        !          2707: ** or in an ORDER BY or GROUP BY clause.</dd>)^
        !          2708: **
        !          2709: ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
        !          2710: ** <dd>The maximum depth of the parse tree on any expression.</dd>)^
        !          2711: **
        !          2712: ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
        !          2713: ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
        !          2714: **
        !          2715: ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt>
        !          2716: ** <dd>The maximum number of instructions in a virtual machine program
        !          2717: ** used to implement an SQL statement.  This limit is not currently
        !          2718: ** enforced, though that might be added in some future release of
        !          2719: ** SQLite.</dd>)^
        !          2720: **
        !          2721: ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
        !          2722: ** <dd>The maximum number of arguments on a function.</dd>)^
        !          2723: **
        !          2724: ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt>
        !          2725: ** <dd>The maximum number of [ATTACH | attached databases].)^</dd>
        !          2726: **
        !          2727: ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]]
        !          2728: ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
        !          2729: ** <dd>The maximum length of the pattern argument to the [LIKE] or
        !          2730: ** [GLOB] operators.</dd>)^
        !          2731: **
        !          2732: ** [[SQLITE_LIMIT_VARIABLE_NUMBER]]
        !          2733: ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
        !          2734: ** <dd>The maximum index number of any [parameter] in an SQL statement.)^
        !          2735: **
        !          2736: ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
        !          2737: ** <dd>The maximum depth of recursion for triggers.</dd>)^
        !          2738: ** </dl>
        !          2739: */
        !          2740: #define SQLITE_LIMIT_LENGTH                    0
        !          2741: #define SQLITE_LIMIT_SQL_LENGTH                1
        !          2742: #define SQLITE_LIMIT_COLUMN                    2
        !          2743: #define SQLITE_LIMIT_EXPR_DEPTH                3
        !          2744: #define SQLITE_LIMIT_COMPOUND_SELECT           4
        !          2745: #define SQLITE_LIMIT_VDBE_OP                   5
        !          2746: #define SQLITE_LIMIT_FUNCTION_ARG              6
        !          2747: #define SQLITE_LIMIT_ATTACHED                  7
        !          2748: #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH       8
        !          2749: #define SQLITE_LIMIT_VARIABLE_NUMBER           9
        !          2750: #define SQLITE_LIMIT_TRIGGER_DEPTH            10
        !          2751: 
        !          2752: /*
        !          2753: ** CAPI3REF: Compiling An SQL Statement
        !          2754: ** KEYWORDS: {SQL statement compiler}
        !          2755: **
        !          2756: ** To execute an SQL query, it must first be compiled into a byte-code
        !          2757: ** program using one of these routines.
        !          2758: **
        !          2759: ** The first argument, "db", is a [database connection] obtained from a
        !          2760: ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
        !          2761: ** [sqlite3_open16()].  The database connection must not have been closed.
        !          2762: **
        !          2763: ** The second argument, "zSql", is the statement to be compiled, encoded
        !          2764: ** as either UTF-8 or UTF-16.  The sqlite3_prepare() and sqlite3_prepare_v2()
        !          2765: ** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2()
        !          2766: ** use UTF-16.
        !          2767: **
        !          2768: ** ^If the nByte argument is less than zero, then zSql is read up to the
        !          2769: ** first zero terminator. ^If nByte is non-negative, then it is the maximum
        !          2770: ** number of  bytes read from zSql.  ^When nByte is non-negative, the
        !          2771: ** zSql string ends at either the first '\000' or '\u0000' character or
        !          2772: ** the nByte-th byte, whichever comes first. If the caller knows
        !          2773: ** that the supplied string is nul-terminated, then there is a small
        !          2774: ** performance advantage to be gained by passing an nByte parameter that
        !          2775: ** is equal to the number of bytes in the input string <i>including</i>
        !          2776: ** the nul-terminator bytes.
        !          2777: **
        !          2778: ** ^If pzTail is not NULL then *pzTail is made to point to the first byte
        !          2779: ** past the end of the first SQL statement in zSql.  These routines only
        !          2780: ** compile the first statement in zSql, so *pzTail is left pointing to
        !          2781: ** what remains uncompiled.
        !          2782: **
        !          2783: ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
        !          2784: ** executed using [sqlite3_step()].  ^If there is an error, *ppStmt is set
        !          2785: ** to NULL.  ^If the input text contains no SQL (if the input is an empty
        !          2786: ** string or a comment) then *ppStmt is set to NULL.
        !          2787: ** The calling procedure is responsible for deleting the compiled
        !          2788: ** SQL statement using [sqlite3_finalize()] after it has finished with it.
        !          2789: ** ppStmt may not be NULL.
        !          2790: **
        !          2791: ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
        !          2792: ** otherwise an [error code] is returned.
        !          2793: **
        !          2794: ** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are
        !          2795: ** recommended for all new programs. The two older interfaces are retained
        !          2796: ** for backwards compatibility, but their use is discouraged.
        !          2797: ** ^In the "v2" interfaces, the prepared statement
        !          2798: ** that is returned (the [sqlite3_stmt] object) contains a copy of the
        !          2799: ** original SQL text. This causes the [sqlite3_step()] interface to
        !          2800: ** behave differently in three ways:
        !          2801: **
        !          2802: ** <ol>
        !          2803: ** <li>
        !          2804: ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
        !          2805: ** always used to do, [sqlite3_step()] will automatically recompile the SQL
        !          2806: ** statement and try to run it again.
        !          2807: ** </li>
        !          2808: **
        !          2809: ** <li>
        !          2810: ** ^When an error occurs, [sqlite3_step()] will return one of the detailed
        !          2811: ** [error codes] or [extended error codes].  ^The legacy behavior was that
        !          2812: ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
        !          2813: ** and the application would have to make a second call to [sqlite3_reset()]
        !          2814: ** in order to find the underlying cause of the problem. With the "v2" prepare
        !          2815: ** interfaces, the underlying reason for the error is returned immediately.
        !          2816: ** </li>
        !          2817: **
        !          2818: ** <li>
        !          2819: ** ^If the specific value bound to [parameter | host parameter] in the 
        !          2820: ** WHERE clause might influence the choice of query plan for a statement,
        !          2821: ** then the statement will be automatically recompiled, as if there had been 
        !          2822: ** a schema change, on the first  [sqlite3_step()] call following any change
        !          2823: ** to the [sqlite3_bind_text | bindings] of that [parameter]. 
        !          2824: ** ^The specific value of WHERE-clause [parameter] might influence the 
        !          2825: ** choice of query plan if the parameter is the left-hand side of a [LIKE]
        !          2826: ** or [GLOB] operator or if the parameter is compared to an indexed column
        !          2827: ** and the [SQLITE_ENABLE_STAT2] compile-time option is enabled.
        !          2828: ** the 
        !          2829: ** </li>
        !          2830: ** </ol>
        !          2831: */
        !          2832: SQLITE_API int sqlite3_prepare(
        !          2833:   sqlite3 *db,            /* Database handle */
        !          2834:   const char *zSql,       /* SQL statement, UTF-8 encoded */
        !          2835:   int nByte,              /* Maximum length of zSql in bytes. */
        !          2836:   sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
        !          2837:   const char **pzTail     /* OUT: Pointer to unused portion of zSql */
        !          2838: );
        !          2839: SQLITE_API int sqlite3_prepare_v2(
        !          2840:   sqlite3 *db,            /* Database handle */
        !          2841:   const char *zSql,       /* SQL statement, UTF-8 encoded */
        !          2842:   int nByte,              /* Maximum length of zSql in bytes. */
        !          2843:   sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
        !          2844:   const char **pzTail     /* OUT: Pointer to unused portion of zSql */
        !          2845: );
        !          2846: SQLITE_API int sqlite3_prepare16(
        !          2847:   sqlite3 *db,            /* Database handle */
        !          2848:   const void *zSql,       /* SQL statement, UTF-16 encoded */
        !          2849:   int nByte,              /* Maximum length of zSql in bytes. */
        !          2850:   sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
        !          2851:   const void **pzTail     /* OUT: Pointer to unused portion of zSql */
        !          2852: );
        !          2853: SQLITE_API int sqlite3_prepare16_v2(
        !          2854:   sqlite3 *db,            /* Database handle */
        !          2855:   const void *zSql,       /* SQL statement, UTF-16 encoded */
        !          2856:   int nByte,              /* Maximum length of zSql in bytes. */
        !          2857:   sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
        !          2858:   const void **pzTail     /* OUT: Pointer to unused portion of zSql */
        !          2859: );
        !          2860: 
        !          2861: /*
        !          2862: ** CAPI3REF: Retrieving Statement SQL
        !          2863: **
        !          2864: ** ^This interface can be used to retrieve a saved copy of the original
        !          2865: ** SQL text used to create a [prepared statement] if that statement was
        !          2866: ** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()].
        !          2867: */
        !          2868: SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt);
        !          2869: 
        !          2870: /*
        !          2871: ** CAPI3REF: Determine If An SQL Statement Writes The Database
        !          2872: **
        !          2873: ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
        !          2874: ** and only if the [prepared statement] X makes no direct changes to
        !          2875: ** the content of the database file.
        !          2876: **
        !          2877: ** Note that [application-defined SQL functions] or
        !          2878: ** [virtual tables] might change the database indirectly as a side effect.  
        !          2879: ** ^(For example, if an application defines a function "eval()" that 
        !          2880: ** calls [sqlite3_exec()], then the following SQL statement would
        !          2881: ** change the database file through side-effects:
        !          2882: **
        !          2883: ** <blockquote><pre>
        !          2884: **    SELECT eval('DELETE FROM t1') FROM t2;
        !          2885: ** </pre></blockquote>
        !          2886: **
        !          2887: ** But because the [SELECT] statement does not change the database file
        !          2888: ** directly, sqlite3_stmt_readonly() would still return true.)^
        !          2889: **
        !          2890: ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
        !          2891: ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
        !          2892: ** since the statements themselves do not actually modify the database but
        !          2893: ** rather they control the timing of when other statements modify the 
        !          2894: ** database.  ^The [ATTACH] and [DETACH] statements also cause
        !          2895: ** sqlite3_stmt_readonly() to return true since, while those statements
        !          2896: ** change the configuration of a database connection, they do not make 
        !          2897: ** changes to the content of the database files on disk.
        !          2898: */
        !          2899: SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
        !          2900: 
        !          2901: /*
        !          2902: ** CAPI3REF: Dynamically Typed Value Object
        !          2903: ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
        !          2904: **
        !          2905: ** SQLite uses the sqlite3_value object to represent all values
        !          2906: ** that can be stored in a database table. SQLite uses dynamic typing
        !          2907: ** for the values it stores.  ^Values stored in sqlite3_value objects
        !          2908: ** can be integers, floating point values, strings, BLOBs, or NULL.
        !          2909: **
        !          2910: ** An sqlite3_value object may be either "protected" or "unprotected".
        !          2911: ** Some interfaces require a protected sqlite3_value.  Other interfaces
        !          2912: ** will accept either a protected or an unprotected sqlite3_value.
        !          2913: ** Every interface that accepts sqlite3_value arguments specifies
        !          2914: ** whether or not it requires a protected sqlite3_value.
        !          2915: **
        !          2916: ** The terms "protected" and "unprotected" refer to whether or not
        !          2917: ** a mutex is held.  An internal mutex is held for a protected
        !          2918: ** sqlite3_value object but no mutex is held for an unprotected
        !          2919: ** sqlite3_value object.  If SQLite is compiled to be single-threaded
        !          2920: ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
        !          2921: ** or if SQLite is run in one of reduced mutex modes 
        !          2922: ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
        !          2923: ** then there is no distinction between protected and unprotected
        !          2924: ** sqlite3_value objects and they can be used interchangeably.  However,
        !          2925: ** for maximum code portability it is recommended that applications
        !          2926: ** still make the distinction between protected and unprotected
        !          2927: ** sqlite3_value objects even when not strictly required.
        !          2928: **
        !          2929: ** ^The sqlite3_value objects that are passed as parameters into the
        !          2930: ** implementation of [application-defined SQL functions] are protected.
        !          2931: ** ^The sqlite3_value object returned by
        !          2932: ** [sqlite3_column_value()] is unprotected.
        !          2933: ** Unprotected sqlite3_value objects may only be used with
        !          2934: ** [sqlite3_result_value()] and [sqlite3_bind_value()].
        !          2935: ** The [sqlite3_value_blob | sqlite3_value_type()] family of
        !          2936: ** interfaces require protected sqlite3_value objects.
        !          2937: */
        !          2938: typedef struct Mem sqlite3_value;
        !          2939: 
        !          2940: /*
        !          2941: ** CAPI3REF: SQL Function Context Object
        !          2942: **
        !          2943: ** The context in which an SQL function executes is stored in an
        !          2944: ** sqlite3_context object.  ^A pointer to an sqlite3_context object
        !          2945: ** is always first parameter to [application-defined SQL functions].
        !          2946: ** The application-defined SQL function implementation will pass this
        !          2947: ** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
        !          2948: ** [sqlite3_aggregate_context()], [sqlite3_user_data()],
        !          2949: ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
        !          2950: ** and/or [sqlite3_set_auxdata()].
        !          2951: */
        !          2952: typedef struct sqlite3_context sqlite3_context;
        !          2953: 
        !          2954: /*
        !          2955: ** CAPI3REF: Binding Values To Prepared Statements
        !          2956: ** KEYWORDS: {host parameter} {host parameters} {host parameter name}
        !          2957: ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
        !          2958: **
        !          2959: ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
        !          2960: ** literals may be replaced by a [parameter] that matches one of following
        !          2961: ** templates:
        !          2962: **
        !          2963: ** <ul>
        !          2964: ** <li>  ?
        !          2965: ** <li>  ?NNN
        !          2966: ** <li>  :VVV
        !          2967: ** <li>  @VVV
        !          2968: ** <li>  $VVV
        !          2969: ** </ul>
        !          2970: **
        !          2971: ** In the templates above, NNN represents an integer literal,
        !          2972: ** and VVV represents an alphanumeric identifier.)^  ^The values of these
        !          2973: ** parameters (also called "host parameter names" or "SQL parameters")
        !          2974: ** can be set using the sqlite3_bind_*() routines defined here.
        !          2975: **
        !          2976: ** ^The first argument to the sqlite3_bind_*() routines is always
        !          2977: ** a pointer to the [sqlite3_stmt] object returned from
        !          2978: ** [sqlite3_prepare_v2()] or its variants.
        !          2979: **
        !          2980: ** ^The second argument is the index of the SQL parameter to be set.
        !          2981: ** ^The leftmost SQL parameter has an index of 1.  ^When the same named
        !          2982: ** SQL parameter is used more than once, second and subsequent
        !          2983: ** occurrences have the same index as the first occurrence.
        !          2984: ** ^The index for named parameters can be looked up using the
        !          2985: ** [sqlite3_bind_parameter_index()] API if desired.  ^The index
        !          2986: ** for "?NNN" parameters is the value of NNN.
        !          2987: ** ^The NNN value must be between 1 and the [sqlite3_limit()]
        !          2988: ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999).
        !          2989: **
        !          2990: ** ^The third argument is the value to bind to the parameter.
        !          2991: **
        !          2992: ** ^(In those routines that have a fourth argument, its value is the
        !          2993: ** number of bytes in the parameter.  To be clear: the value is the
        !          2994: ** number of <u>bytes</u> in the value, not the number of characters.)^
        !          2995: ** ^If the fourth parameter is negative, the length of the string is
        !          2996: ** the number of bytes up to the first zero terminator.
        !          2997: **
        !          2998: ** ^The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and
        !          2999: ** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or
        !          3000: ** string after SQLite has finished with it.  ^The destructor is called
        !          3001: ** to dispose of the BLOB or string even if the call to sqlite3_bind_blob(),
        !          3002: ** sqlite3_bind_text(), or sqlite3_bind_text16() fails.  
        !          3003: ** ^If the fifth argument is
        !          3004: ** the special value [SQLITE_STATIC], then SQLite assumes that the
        !          3005: ** information is in static, unmanaged space and does not need to be freed.
        !          3006: ** ^If the fifth argument has the value [SQLITE_TRANSIENT], then
        !          3007: ** SQLite makes its own private copy of the data immediately, before
        !          3008: ** the sqlite3_bind_*() routine returns.
        !          3009: **
        !          3010: ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
        !          3011: ** is filled with zeroes.  ^A zeroblob uses a fixed amount of memory
        !          3012: ** (just an integer to hold its size) while it is being processed.
        !          3013: ** Zeroblobs are intended to serve as placeholders for BLOBs whose
        !          3014: ** content is later written using
        !          3015: ** [sqlite3_blob_open | incremental BLOB I/O] routines.
        !          3016: ** ^A negative value for the zeroblob results in a zero-length BLOB.
        !          3017: **
        !          3018: ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
        !          3019: ** for the [prepared statement] or with a prepared statement for which
        !          3020: ** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
        !          3021: ** then the call will return [SQLITE_MISUSE].  If any sqlite3_bind_()
        !          3022: ** routine is passed a [prepared statement] that has been finalized, the
        !          3023: ** result is undefined and probably harmful.
        !          3024: **
        !          3025: ** ^Bindings are not cleared by the [sqlite3_reset()] routine.
        !          3026: ** ^Unbound parameters are interpreted as NULL.
        !          3027: **
        !          3028: ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
        !          3029: ** [error code] if anything goes wrong.
        !          3030: ** ^[SQLITE_RANGE] is returned if the parameter
        !          3031: ** index is out of range.  ^[SQLITE_NOMEM] is returned if malloc() fails.
        !          3032: **
        !          3033: ** See also: [sqlite3_bind_parameter_count()],
        !          3034: ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
        !          3035: */
        !          3036: SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
        !          3037: SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double);
        !          3038: SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int);
        !          3039: SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
        !          3040: SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int);
        !          3041: SQLITE_API int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*));
        !          3042: SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
        !          3043: SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
        !          3044: SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
        !          3045: 
        !          3046: /*
        !          3047: ** CAPI3REF: Number Of SQL Parameters
        !          3048: **
        !          3049: ** ^This routine can be used to find the number of [SQL parameters]
        !          3050: ** in a [prepared statement].  SQL parameters are tokens of the
        !          3051: ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
        !          3052: ** placeholders for values that are [sqlite3_bind_blob | bound]
        !          3053: ** to the parameters at a later time.
        !          3054: **
        !          3055: ** ^(This routine actually returns the index of the largest (rightmost)
        !          3056: ** parameter. For all forms except ?NNN, this will correspond to the
        !          3057: ** number of unique parameters.  If parameters of the ?NNN form are used,
        !          3058: ** there may be gaps in the list.)^
        !          3059: **
        !          3060: ** See also: [sqlite3_bind_blob|sqlite3_bind()],
        !          3061: ** [sqlite3_bind_parameter_name()], and
        !          3062: ** [sqlite3_bind_parameter_index()].
        !          3063: */
        !          3064: SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*);
        !          3065: 
        !          3066: /*
        !          3067: ** CAPI3REF: Name Of A Host Parameter
        !          3068: **
        !          3069: ** ^The sqlite3_bind_parameter_name(P,N) interface returns
        !          3070: ** the name of the N-th [SQL parameter] in the [prepared statement] P.
        !          3071: ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
        !          3072: ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
        !          3073: ** respectively.
        !          3074: ** In other words, the initial ":" or "$" or "@" or "?"
        !          3075: ** is included as part of the name.)^
        !          3076: ** ^Parameters of the form "?" without a following integer have no name
        !          3077: ** and are referred to as "nameless" or "anonymous parameters".
        !          3078: **
        !          3079: ** ^The first host parameter has an index of 1, not 0.
        !          3080: **
        !          3081: ** ^If the value N is out of range or if the N-th parameter is
        !          3082: ** nameless, then NULL is returned.  ^The returned string is
        !          3083: ** always in UTF-8 encoding even if the named parameter was
        !          3084: ** originally specified as UTF-16 in [sqlite3_prepare16()] or
        !          3085: ** [sqlite3_prepare16_v2()].
        !          3086: **
        !          3087: ** See also: [sqlite3_bind_blob|sqlite3_bind()],
        !          3088: ** [sqlite3_bind_parameter_count()], and
        !          3089: ** [sqlite3_bind_parameter_index()].
        !          3090: */
        !          3091: SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
        !          3092: 
        !          3093: /*
        !          3094: ** CAPI3REF: Index Of A Parameter With A Given Name
        !          3095: **
        !          3096: ** ^Return the index of an SQL parameter given its name.  ^The
        !          3097: ** index value returned is suitable for use as the second
        !          3098: ** parameter to [sqlite3_bind_blob|sqlite3_bind()].  ^A zero
        !          3099: ** is returned if no matching parameter is found.  ^The parameter
        !          3100: ** name must be given in UTF-8 even if the original statement
        !          3101: ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()].
        !          3102: **
        !          3103: ** See also: [sqlite3_bind_blob|sqlite3_bind()],
        !          3104: ** [sqlite3_bind_parameter_count()], and
        !          3105: ** [sqlite3_bind_parameter_index()].
        !          3106: */
        !          3107: SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
        !          3108: 
        !          3109: /*
        !          3110: ** CAPI3REF: Reset All Bindings On A Prepared Statement
        !          3111: **
        !          3112: ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
        !          3113: ** the [sqlite3_bind_blob | bindings] on a [prepared statement].
        !          3114: ** ^Use this routine to reset all host parameters to NULL.
        !          3115: */
        !          3116: SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*);
        !          3117: 
        !          3118: /*
        !          3119: ** CAPI3REF: Number Of Columns In A Result Set
        !          3120: **
        !          3121: ** ^Return the number of columns in the result set returned by the
        !          3122: ** [prepared statement]. ^This routine returns 0 if pStmt is an SQL
        !          3123: ** statement that does not return data (for example an [UPDATE]).
        !          3124: **
        !          3125: ** See also: [sqlite3_data_count()]
        !          3126: */
        !          3127: SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt);
        !          3128: 
        !          3129: /*
        !          3130: ** CAPI3REF: Column Names In A Result Set
        !          3131: **
        !          3132: ** ^These routines return the name assigned to a particular column
        !          3133: ** in the result set of a [SELECT] statement.  ^The sqlite3_column_name()
        !          3134: ** interface returns a pointer to a zero-terminated UTF-8 string
        !          3135: ** and sqlite3_column_name16() returns a pointer to a zero-terminated
        !          3136: ** UTF-16 string.  ^The first parameter is the [prepared statement]
        !          3137: ** that implements the [SELECT] statement. ^The second parameter is the
        !          3138: ** column number.  ^The leftmost column is number 0.
        !          3139: **
        !          3140: ** ^The returned string pointer is valid until either the [prepared statement]
        !          3141: ** is destroyed by [sqlite3_finalize()] or until the statement is automatically
        !          3142: ** reprepared by the first call to [sqlite3_step()] for a particular run
        !          3143: ** or until the next call to
        !          3144: ** sqlite3_column_name() or sqlite3_column_name16() on the same column.
        !          3145: **
        !          3146: ** ^If sqlite3_malloc() fails during the processing of either routine
        !          3147: ** (for example during a conversion from UTF-8 to UTF-16) then a
        !          3148: ** NULL pointer is returned.
        !          3149: **
        !          3150: ** ^The name of a result column is the value of the "AS" clause for
        !          3151: ** that column, if there is an AS clause.  If there is no AS clause
        !          3152: ** then the name of the column is unspecified and may change from
        !          3153: ** one release of SQLite to the next.
        !          3154: */
        !          3155: SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N);
        !          3156: SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N);
        !          3157: 
        !          3158: /*
        !          3159: ** CAPI3REF: Source Of Data In A Query Result
        !          3160: **
        !          3161: ** ^These routines provide a means to determine the database, table, and
        !          3162: ** table column that is the origin of a particular result column in
        !          3163: ** [SELECT] statement.
        !          3164: ** ^The name of the database or table or column can be returned as
        !          3165: ** either a UTF-8 or UTF-16 string.  ^The _database_ routines return
        !          3166: ** the database name, the _table_ routines return the table name, and
        !          3167: ** the origin_ routines return the column name.
        !          3168: ** ^The returned string is valid until the [prepared statement] is destroyed
        !          3169: ** using [sqlite3_finalize()] or until the statement is automatically
        !          3170: ** reprepared by the first call to [sqlite3_step()] for a particular run
        !          3171: ** or until the same information is requested
        !          3172: ** again in a different encoding.
        !          3173: **
        !          3174: ** ^The names returned are the original un-aliased names of the
        !          3175: ** database, table, and column.
        !          3176: **
        !          3177: ** ^The first argument to these interfaces is a [prepared statement].
        !          3178: ** ^These functions return information about the Nth result column returned by
        !          3179: ** the statement, where N is the second function argument.
        !          3180: ** ^The left-most column is column 0 for these routines.
        !          3181: **
        !          3182: ** ^If the Nth column returned by the statement is an expression or
        !          3183: ** subquery and is not a column value, then all of these functions return
        !          3184: ** NULL.  ^These routine might also return NULL if a memory allocation error
        !          3185: ** occurs.  ^Otherwise, they return the name of the attached database, table,
        !          3186: ** or column that query result column was extracted from.
        !          3187: **
        !          3188: ** ^As with all other SQLite APIs, those whose names end with "16" return
        !          3189: ** UTF-16 encoded strings and the other functions return UTF-8.
        !          3190: **
        !          3191: ** ^These APIs are only available if the library was compiled with the
        !          3192: ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol.
        !          3193: **
        !          3194: ** If two or more threads call one or more of these routines against the same
        !          3195: ** prepared statement and column at the same time then the results are
        !          3196: ** undefined.
        !          3197: **
        !          3198: ** If two or more threads call one or more
        !          3199: ** [sqlite3_column_database_name | column metadata interfaces]
        !          3200: ** for the same [prepared statement] and result column
        !          3201: ** at the same time then the results are undefined.
        !          3202: */
        !          3203: SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int);
        !          3204: SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
        !          3205: SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int);
        !          3206: SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
        !          3207: SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
        !          3208: SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
        !          3209: 
        !          3210: /*
        !          3211: ** CAPI3REF: Declared Datatype Of A Query Result
        !          3212: **
        !          3213: ** ^(The first parameter is a [prepared statement].
        !          3214: ** If this statement is a [SELECT] statement and the Nth column of the
        !          3215: ** returned result set of that [SELECT] is a table column (not an
        !          3216: ** expression or subquery) then the declared type of the table
        !          3217: ** column is returned.)^  ^If the Nth column of the result set is an
        !          3218: ** expression or subquery, then a NULL pointer is returned.
        !          3219: ** ^The returned string is always UTF-8 encoded.
        !          3220: **
        !          3221: ** ^(For example, given the database schema:
        !          3222: **
        !          3223: ** CREATE TABLE t1(c1 VARIANT);
        !          3224: **
        !          3225: ** and the following statement to be compiled:
        !          3226: **
        !          3227: ** SELECT c1 + 1, c1 FROM t1;
        !          3228: **
        !          3229: ** this routine would return the string "VARIANT" for the second result
        !          3230: ** column (i==1), and a NULL pointer for the first result column (i==0).)^
        !          3231: **
        !          3232: ** ^SQLite uses dynamic run-time typing.  ^So just because a column
        !          3233: ** is declared to contain a particular type does not mean that the
        !          3234: ** data stored in that column is of the declared type.  SQLite is
        !          3235: ** strongly typed, but the typing is dynamic not static.  ^Type
        !          3236: ** is associated with individual values, not with the containers
        !          3237: ** used to hold those values.
        !          3238: */
        !          3239: SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int);
        !          3240: SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
        !          3241: 
        !          3242: /*
        !          3243: ** CAPI3REF: Evaluate An SQL Statement
        !          3244: **
        !          3245: ** After a [prepared statement] has been prepared using either
        !          3246: ** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy
        !          3247: ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
        !          3248: ** must be called one or more times to evaluate the statement.
        !          3249: **
        !          3250: ** The details of the behavior of the sqlite3_step() interface depend
        !          3251: ** on whether the statement was prepared using the newer "v2" interface
        !          3252: ** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy
        !          3253: ** interface [sqlite3_prepare()] and [sqlite3_prepare16()].  The use of the
        !          3254: ** new "v2" interface is recommended for new applications but the legacy
        !          3255: ** interface will continue to be supported.
        !          3256: **
        !          3257: ** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
        !          3258: ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
        !          3259: ** ^With the "v2" interface, any of the other [result codes] or
        !          3260: ** [extended result codes] might be returned as well.
        !          3261: **
        !          3262: ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the
        !          3263: ** database locks it needs to do its job.  ^If the statement is a [COMMIT]
        !          3264: ** or occurs outside of an explicit transaction, then you can retry the
        !          3265: ** statement.  If the statement is not a [COMMIT] and occurs within an
        !          3266: ** explicit transaction then you should rollback the transaction before
        !          3267: ** continuing.
        !          3268: **
        !          3269: ** ^[SQLITE_DONE] means that the statement has finished executing
        !          3270: ** successfully.  sqlite3_step() should not be called again on this virtual
        !          3271: ** machine without first calling [sqlite3_reset()] to reset the virtual
        !          3272: ** machine back to its initial state.
        !          3273: **
        !          3274: ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]
        !          3275: ** is returned each time a new row of data is ready for processing by the
        !          3276: ** caller. The values may be accessed using the [column access functions].
        !          3277: ** sqlite3_step() is called again to retrieve the next row of data.
        !          3278: **
        !          3279: ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint
        !          3280: ** violation) has occurred.  sqlite3_step() should not be called again on
        !          3281: ** the VM. More information may be found by calling [sqlite3_errmsg()].
        !          3282: ** ^With the legacy interface, a more specific error code (for example,
        !          3283: ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
        !          3284: ** can be obtained by calling [sqlite3_reset()] on the
        !          3285: ** [prepared statement].  ^In the "v2" interface,
        !          3286: ** the more specific error code is returned directly by sqlite3_step().
        !          3287: **
        !          3288: ** [SQLITE_MISUSE] means that the this routine was called inappropriately.
        !          3289: ** Perhaps it was called on a [prepared statement] that has
        !          3290: ** already been [sqlite3_finalize | finalized] or on one that had
        !          3291: ** previously returned [SQLITE_ERROR] or [SQLITE_DONE].  Or it could
        !          3292: ** be the case that the same database connection is being used by two or
        !          3293: ** more threads at the same moment in time.
        !          3294: **
        !          3295: ** For all versions of SQLite up to and including 3.6.23.1, a call to
        !          3296: ** [sqlite3_reset()] was required after sqlite3_step() returned anything
        !          3297: ** other than [SQLITE_ROW] before any subsequent invocation of
        !          3298: ** sqlite3_step().  Failure to reset the prepared statement using 
        !          3299: ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from
        !          3300: ** sqlite3_step().  But after version 3.6.23.1, sqlite3_step() began
        !          3301: ** calling [sqlite3_reset()] automatically in this circumstance rather
        !          3302: ** than returning [SQLITE_MISUSE].  This is not considered a compatibility
        !          3303: ** break because any application that ever receives an SQLITE_MISUSE error
        !          3304: ** is broken by definition.  The [SQLITE_OMIT_AUTORESET] compile-time option
        !          3305: ** can be used to restore the legacy behavior.
        !          3306: **
        !          3307: ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
        !          3308: ** API always returns a generic error code, [SQLITE_ERROR], following any
        !          3309: ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE].  You must call
        !          3310: ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
        !          3311: ** specific [error codes] that better describes the error.
        !          3312: ** We admit that this is a goofy design.  The problem has been fixed
        !          3313: ** with the "v2" interface.  If you prepare all of your SQL statements
        !          3314: ** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead
        !          3315: ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
        !          3316: ** then the more specific [error codes] are returned directly
        !          3317: ** by sqlite3_step().  The use of the "v2" interface is recommended.
        !          3318: */
        !          3319: SQLITE_API int sqlite3_step(sqlite3_stmt*);
        !          3320: 
        !          3321: /*
        !          3322: ** CAPI3REF: Number of columns in a result set
        !          3323: **
        !          3324: ** ^The sqlite3_data_count(P) interface returns the number of columns in the
        !          3325: ** current row of the result set of [prepared statement] P.
        !          3326: ** ^If prepared statement P does not have results ready to return
        !          3327: ** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of
        !          3328: ** interfaces) then sqlite3_data_count(P) returns 0.
        !          3329: ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer.
        !          3330: **
        !          3331: ** See also: [sqlite3_column_count()]
        !          3332: */
        !          3333: SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
        !          3334: 
        !          3335: /*
        !          3336: ** CAPI3REF: Fundamental Datatypes
        !          3337: ** KEYWORDS: SQLITE_TEXT
        !          3338: **
        !          3339: ** ^(Every value in SQLite has one of five fundamental datatypes:
        !          3340: **
        !          3341: ** <ul>
        !          3342: ** <li> 64-bit signed integer
        !          3343: ** <li> 64-bit IEEE floating point number
        !          3344: ** <li> string
        !          3345: ** <li> BLOB
        !          3346: ** <li> NULL
        !          3347: ** </ul>)^
        !          3348: **
        !          3349: ** These constants are codes for each of those types.
        !          3350: **
        !          3351: ** Note that the SQLITE_TEXT constant was also used in SQLite version 2
        !          3352: ** for a completely different meaning.  Software that links against both
        !          3353: ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
        !          3354: ** SQLITE_TEXT.
        !          3355: */
        !          3356: #define SQLITE_INTEGER  1
        !          3357: #define SQLITE_FLOAT    2
        !          3358: #define SQLITE_BLOB     4
        !          3359: #define SQLITE_NULL     5
        !          3360: #ifdef SQLITE_TEXT
        !          3361: # undef SQLITE_TEXT
        !          3362: #else
        !          3363: # define SQLITE_TEXT     3
        !          3364: #endif
        !          3365: #define SQLITE3_TEXT     3
        !          3366: 
        !          3367: /*
        !          3368: ** CAPI3REF: Result Values From A Query
        !          3369: ** KEYWORDS: {column access functions}
        !          3370: **
        !          3371: ** These routines form the "result set" interface.
        !          3372: **
        !          3373: ** ^These routines return information about a single column of the current
        !          3374: ** result row of a query.  ^In every case the first argument is a pointer
        !          3375: ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
        !          3376: ** that was returned from [sqlite3_prepare_v2()] or one of its variants)
        !          3377: ** and the second argument is the index of the column for which information
        !          3378: ** should be returned. ^The leftmost column of the result set has the index 0.
        !          3379: ** ^The number of columns in the result can be determined using
        !          3380: ** [sqlite3_column_count()].
        !          3381: **
        !          3382: ** If the SQL statement does not currently point to a valid row, or if the
        !          3383: ** column index is out of range, the result is undefined.
        !          3384: ** These routines may only be called when the most recent call to
        !          3385: ** [sqlite3_step()] has returned [SQLITE_ROW] and neither
        !          3386: ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
        !          3387: ** If any of these routines are called after [sqlite3_reset()] or
        !          3388: ** [sqlite3_finalize()] or after [sqlite3_step()] has returned
        !          3389: ** something other than [SQLITE_ROW], the results are undefined.
        !          3390: ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
        !          3391: ** are called from a different thread while any of these routines
        !          3392: ** are pending, then the results are undefined.
        !          3393: **
        !          3394: ** ^The sqlite3_column_type() routine returns the
        !          3395: ** [SQLITE_INTEGER | datatype code] for the initial data type
        !          3396: ** of the result column.  ^The returned value is one of [SQLITE_INTEGER],
        !          3397: ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].  The value
        !          3398: ** returned by sqlite3_column_type() is only meaningful if no type
        !          3399: ** conversions have occurred as described below.  After a type conversion,
        !          3400: ** the value returned by sqlite3_column_type() is undefined.  Future
        !          3401: ** versions of SQLite may change the behavior of sqlite3_column_type()
        !          3402: ** following a type conversion.
        !          3403: **
        !          3404: ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
        !          3405: ** routine returns the number of bytes in that BLOB or string.
        !          3406: ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
        !          3407: ** the string to UTF-8 and then returns the number of bytes.
        !          3408: ** ^If the result is a numeric value then sqlite3_column_bytes() uses
        !          3409: ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
        !          3410: ** the number of bytes in that string.
        !          3411: ** ^If the result is NULL, then sqlite3_column_bytes() returns zero.
        !          3412: **
        !          3413: ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16()
        !          3414: ** routine returns the number of bytes in that BLOB or string.
        !          3415: ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts
        !          3416: ** the string to UTF-16 and then returns the number of bytes.
        !          3417: ** ^If the result is a numeric value then sqlite3_column_bytes16() uses
        !          3418: ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns
        !          3419: ** the number of bytes in that string.
        !          3420: ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero.
        !          3421: **
        !          3422: ** ^The values returned by [sqlite3_column_bytes()] and 
        !          3423: ** [sqlite3_column_bytes16()] do not include the zero terminators at the end
        !          3424: ** of the string.  ^For clarity: the values returned by
        !          3425: ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of
        !          3426: ** bytes in the string, not the number of characters.
        !          3427: **
        !          3428: ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
        !          3429: ** even empty strings, are always zero terminated.  ^The return
        !          3430: ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.
        !          3431: **
        !          3432: ** ^The object returned by [sqlite3_column_value()] is an
        !          3433: ** [unprotected sqlite3_value] object.  An unprotected sqlite3_value object
        !          3434: ** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()].
        !          3435: ** If the [unprotected sqlite3_value] object returned by
        !          3436: ** [sqlite3_column_value()] is used in any other way, including calls
        !          3437: ** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
        !          3438: ** or [sqlite3_value_bytes()], then the behavior is undefined.
        !          3439: **
        !          3440: ** These routines attempt to convert the value where appropriate.  ^For
        !          3441: ** example, if the internal representation is FLOAT and a text result
        !          3442: ** is requested, [sqlite3_snprintf()] is used internally to perform the
        !          3443: ** conversion automatically.  ^(The following table details the conversions
        !          3444: ** that are applied:
        !          3445: **
        !          3446: ** <blockquote>
        !          3447: ** <table border="1">
        !          3448: ** <tr><th> Internal<br>Type <th> Requested<br>Type <th>  Conversion
        !          3449: **
        !          3450: ** <tr><td>  NULL    <td> INTEGER   <td> Result is 0
        !          3451: ** <tr><td>  NULL    <td>  FLOAT    <td> Result is 0.0
        !          3452: ** <tr><td>  NULL    <td>   TEXT    <td> Result is NULL pointer
        !          3453: ** <tr><td>  NULL    <td>   BLOB    <td> Result is NULL pointer
        !          3454: ** <tr><td> INTEGER  <td>  FLOAT    <td> Convert from integer to float
        !          3455: ** <tr><td> INTEGER  <td>   TEXT    <td> ASCII rendering of the integer
        !          3456: ** <tr><td> INTEGER  <td>   BLOB    <td> Same as INTEGER->TEXT
        !          3457: ** <tr><td>  FLOAT   <td> INTEGER   <td> Convert from float to integer
        !          3458: ** <tr><td>  FLOAT   <td>   TEXT    <td> ASCII rendering of the float
        !          3459: ** <tr><td>  FLOAT   <td>   BLOB    <td> Same as FLOAT->TEXT
        !          3460: ** <tr><td>  TEXT    <td> INTEGER   <td> Use atoi()
        !          3461: ** <tr><td>  TEXT    <td>  FLOAT    <td> Use atof()
        !          3462: ** <tr><td>  TEXT    <td>   BLOB    <td> No change
        !          3463: ** <tr><td>  BLOB    <td> INTEGER   <td> Convert to TEXT then use atoi()
        !          3464: ** <tr><td>  BLOB    <td>  FLOAT    <td> Convert to TEXT then use atof()
        !          3465: ** <tr><td>  BLOB    <td>   TEXT    <td> Add a zero terminator if needed
        !          3466: ** </table>
        !          3467: ** </blockquote>)^
        !          3468: **
        !          3469: ** The table above makes reference to standard C library functions atoi()
        !          3470: ** and atof().  SQLite does not really use these functions.  It has its
        !          3471: ** own equivalent internal routines.  The atoi() and atof() names are
        !          3472: ** used in the table for brevity and because they are familiar to most
        !          3473: ** C programmers.
        !          3474: **
        !          3475: ** Note that when type conversions occur, pointers returned by prior
        !          3476: ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
        !          3477: ** sqlite3_column_text16() may be invalidated.
        !          3478: ** Type conversions and pointer invalidations might occur
        !          3479: ** in the following cases:
        !          3480: **
        !          3481: ** <ul>
        !          3482: ** <li> The initial content is a BLOB and sqlite3_column_text() or
        !          3483: **      sqlite3_column_text16() is called.  A zero-terminator might
        !          3484: **      need to be added to the string.</li>
        !          3485: ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
        !          3486: **      sqlite3_column_text16() is called.  The content must be converted
        !          3487: **      to UTF-16.</li>
        !          3488: ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
        !          3489: **      sqlite3_column_text() is called.  The content must be converted
        !          3490: **      to UTF-8.</li>
        !          3491: ** </ul>
        !          3492: **
        !          3493: ** ^Conversions between UTF-16be and UTF-16le are always done in place and do
        !          3494: ** not invalidate a prior pointer, though of course the content of the buffer
        !          3495: ** that the prior pointer references will have been modified.  Other kinds
        !          3496: ** of conversion are done in place when it is possible, but sometimes they
        !          3497: ** are not possible and in those cases prior pointers are invalidated.
        !          3498: **
        !          3499: ** The safest and easiest to remember policy is to invoke these routines
        !          3500: ** in one of the following ways:
        !          3501: **
        !          3502: ** <ul>
        !          3503: **  <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
        !          3504: **  <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
        !          3505: **  <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
        !          3506: ** </ul>
        !          3507: **
        !          3508: ** In other words, you should call sqlite3_column_text(),
        !          3509: ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
        !          3510: ** into the desired format, then invoke sqlite3_column_bytes() or
        !          3511: ** sqlite3_column_bytes16() to find the size of the result.  Do not mix calls
        !          3512: ** to sqlite3_column_text() or sqlite3_column_blob() with calls to
        !          3513: ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
        !          3514: ** with calls to sqlite3_column_bytes().
        !          3515: **
        !          3516: ** ^The pointers returned are valid until a type conversion occurs as
        !          3517: ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
        !          3518: ** [sqlite3_finalize()] is called.  ^The memory space used to hold strings
        !          3519: ** and BLOBs is freed automatically.  Do <b>not</b> pass the pointers returned
        !          3520: ** [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
        !          3521: ** [sqlite3_free()].
        !          3522: **
        !          3523: ** ^(If a memory allocation error occurs during the evaluation of any
        !          3524: ** of these routines, a default value is returned.  The default value
        !          3525: ** is either the integer 0, the floating point number 0.0, or a NULL
        !          3526: ** pointer.  Subsequent calls to [sqlite3_errcode()] will return
        !          3527: ** [SQLITE_NOMEM].)^
        !          3528: */
        !          3529: SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
        !          3530: SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
        !          3531: SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
        !          3532: SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol);
        !          3533: SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol);
        !          3534: SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
        !          3535: SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
        !          3536: SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
        !          3537: SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol);
        !          3538: SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
        !          3539: 
        !          3540: /*
        !          3541: ** CAPI3REF: Destroy A Prepared Statement Object
        !          3542: **
        !          3543: ** ^The sqlite3_finalize() function is called to delete a [prepared statement].
        !          3544: ** ^If the most recent evaluation of the statement encountered no errors
        !          3545: ** or if the statement is never been evaluated, then sqlite3_finalize() returns
        !          3546: ** SQLITE_OK.  ^If the most recent evaluation of statement S failed, then
        !          3547: ** sqlite3_finalize(S) returns the appropriate [error code] or
        !          3548: ** [extended error code].
        !          3549: **
        !          3550: ** ^The sqlite3_finalize(S) routine can be called at any point during
        !          3551: ** the life cycle of [prepared statement] S:
        !          3552: ** before statement S is ever evaluated, after
        !          3553: ** one or more calls to [sqlite3_reset()], or after any call
        !          3554: ** to [sqlite3_step()] regardless of whether or not the statement has
        !          3555: ** completed execution.
        !          3556: **
        !          3557: ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op.
        !          3558: **
        !          3559: ** The application must finalize every [prepared statement] in order to avoid
        !          3560: ** resource leaks.  It is a grievous error for the application to try to use
        !          3561: ** a prepared statement after it has been finalized.  Any use of a prepared
        !          3562: ** statement after it has been finalized can result in undefined and
        !          3563: ** undesirable behavior such as segfaults and heap corruption.
        !          3564: */
        !          3565: SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt);
        !          3566: 
        !          3567: /*
        !          3568: ** CAPI3REF: Reset A Prepared Statement Object
        !          3569: **
        !          3570: ** The sqlite3_reset() function is called to reset a [prepared statement]
        !          3571: ** object back to its initial state, ready to be re-executed.
        !          3572: ** ^Any SQL statement variables that had values bound to them using
        !          3573: ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
        !          3574: ** Use [sqlite3_clear_bindings()] to reset the bindings.
        !          3575: **
        !          3576: ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S
        !          3577: ** back to the beginning of its program.
        !          3578: **
        !          3579: ** ^If the most recent call to [sqlite3_step(S)] for the
        !          3580: ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE],
        !          3581: ** or if [sqlite3_step(S)] has never before been called on S,
        !          3582: ** then [sqlite3_reset(S)] returns [SQLITE_OK].
        !          3583: **
        !          3584: ** ^If the most recent call to [sqlite3_step(S)] for the
        !          3585: ** [prepared statement] S indicated an error, then
        !          3586: ** [sqlite3_reset(S)] returns an appropriate [error code].
        !          3587: **
        !          3588: ** ^The [sqlite3_reset(S)] interface does not change the values
        !          3589: ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
        !          3590: */
        !          3591: SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt);
        !          3592: 
        !          3593: /*
        !          3594: ** CAPI3REF: Create Or Redefine SQL Functions
        !          3595: ** KEYWORDS: {function creation routines}
        !          3596: ** KEYWORDS: {application-defined SQL function}
        !          3597: ** KEYWORDS: {application-defined SQL functions}
        !          3598: **
        !          3599: ** ^These functions (collectively known as "function creation routines")
        !          3600: ** are used to add SQL functions or aggregates or to redefine the behavior
        !          3601: ** of existing SQL functions or aggregates.  The only differences between
        !          3602: ** these routines are the text encoding expected for
        !          3603: ** the second parameter (the name of the function being created)
        !          3604: ** and the presence or absence of a destructor callback for
        !          3605: ** the application data pointer.
        !          3606: **
        !          3607: ** ^The first parameter is the [database connection] to which the SQL
        !          3608: ** function is to be added.  ^If an application uses more than one database
        !          3609: ** connection then application-defined SQL functions must be added
        !          3610: ** to each database connection separately.
        !          3611: **
        !          3612: ** ^The second parameter is the name of the SQL function to be created or
        !          3613: ** redefined.  ^The length of the name is limited to 255 bytes in a UTF-8
        !          3614: ** representation, exclusive of the zero-terminator.  ^Note that the name
        !          3615: ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes.  
        !          3616: ** ^Any attempt to create a function with a longer name
        !          3617: ** will result in [SQLITE_MISUSE] being returned.
        !          3618: **
        !          3619: ** ^The third parameter (nArg)
        !          3620: ** is the number of arguments that the SQL function or
        !          3621: ** aggregate takes. ^If this parameter is -1, then the SQL function or
        !          3622: ** aggregate may take any number of arguments between 0 and the limit
        !          3623: ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]).  If the third
        !          3624: ** parameter is less than -1 or greater than 127 then the behavior is
        !          3625: ** undefined.
        !          3626: **
        !          3627: ** ^The fourth parameter, eTextRep, specifies what
        !          3628: ** [SQLITE_UTF8 | text encoding] this SQL function prefers for
        !          3629: ** its parameters.  Every SQL function implementation must be able to work
        !          3630: ** with UTF-8, UTF-16le, or UTF-16be.  But some implementations may be
        !          3631: ** more efficient with one encoding than another.  ^An application may
        !          3632: ** invoke sqlite3_create_function() or sqlite3_create_function16() multiple
        !          3633: ** times with the same function but with different values of eTextRep.
        !          3634: ** ^When multiple implementations of the same function are available, SQLite
        !          3635: ** will pick the one that involves the least amount of data conversion.
        !          3636: ** If there is only a single implementation which does not care what text
        !          3637: ** encoding is used, then the fourth argument should be [SQLITE_ANY].
        !          3638: **
        !          3639: ** ^(The fifth parameter is an arbitrary pointer.  The implementation of the
        !          3640: ** function can gain access to this pointer using [sqlite3_user_data()].)^
        !          3641: **
        !          3642: ** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are
        !          3643: ** pointers to C-language functions that implement the SQL function or
        !          3644: ** aggregate. ^A scalar SQL function requires an implementation of the xFunc
        !          3645: ** callback only; NULL pointers must be passed as the xStep and xFinal
        !          3646: ** parameters. ^An aggregate SQL function requires an implementation of xStep
        !          3647: ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing
        !          3648: ** SQL function or aggregate, pass NULL pointers for all three function
        !          3649: ** callbacks.
        !          3650: **
        !          3651: ** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL,
        !          3652: ** then it is destructor for the application data pointer. 
        !          3653: ** The destructor is invoked when the function is deleted, either by being
        !          3654: ** overloaded or when the database connection closes.)^
        !          3655: ** ^The destructor is also invoked if the call to
        !          3656: ** sqlite3_create_function_v2() fails.
        !          3657: ** ^When the destructor callback of the tenth parameter is invoked, it
        !          3658: ** is passed a single argument which is a copy of the application data 
        !          3659: ** pointer which was the fifth parameter to sqlite3_create_function_v2().
        !          3660: **
        !          3661: ** ^It is permitted to register multiple implementations of the same
        !          3662: ** functions with the same name but with either differing numbers of
        !          3663: ** arguments or differing preferred text encodings.  ^SQLite will use
        !          3664: ** the implementation that most closely matches the way in which the
        !          3665: ** SQL function is used.  ^A function implementation with a non-negative
        !          3666: ** nArg parameter is a better match than a function implementation with
        !          3667: ** a negative nArg.  ^A function where the preferred text encoding
        !          3668: ** matches the database encoding is a better
        !          3669: ** match than a function where the encoding is different.  
        !          3670: ** ^A function where the encoding difference is between UTF16le and UTF16be
        !          3671: ** is a closer match than a function where the encoding difference is
        !          3672: ** between UTF8 and UTF16.
        !          3673: **
        !          3674: ** ^Built-in functions may be overloaded by new application-defined functions.
        !          3675: **
        !          3676: ** ^An application-defined function is permitted to call other
        !          3677: ** SQLite interfaces.  However, such calls must not
        !          3678: ** close the database connection nor finalize or reset the prepared
        !          3679: ** statement in which the function is running.
        !          3680: */
        !          3681: SQLITE_API int sqlite3_create_function(
        !          3682:   sqlite3 *db,
        !          3683:   const char *zFunctionName,
        !          3684:   int nArg,
        !          3685:   int eTextRep,
        !          3686:   void *pApp,
        !          3687:   void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
        !          3688:   void (*xStep)(sqlite3_context*,int,sqlite3_value**),
        !          3689:   void (*xFinal)(sqlite3_context*)
        !          3690: );
        !          3691: SQLITE_API int sqlite3_create_function16(
        !          3692:   sqlite3 *db,
        !          3693:   const void *zFunctionName,
        !          3694:   int nArg,
        !          3695:   int eTextRep,
        !          3696:   void *pApp,
        !          3697:   void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
        !          3698:   void (*xStep)(sqlite3_context*,int,sqlite3_value**),
        !          3699:   void (*xFinal)(sqlite3_context*)
        !          3700: );
        !          3701: SQLITE_API int sqlite3_create_function_v2(
        !          3702:   sqlite3 *db,
        !          3703:   const char *zFunctionName,
        !          3704:   int nArg,
        !          3705:   int eTextRep,
        !          3706:   void *pApp,
        !          3707:   void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
        !          3708:   void (*xStep)(sqlite3_context*,int,sqlite3_value**),
        !          3709:   void (*xFinal)(sqlite3_context*),
        !          3710:   void(*xDestroy)(void*)
        !          3711: );
        !          3712: 
        !          3713: /*
        !          3714: ** CAPI3REF: Text Encodings
        !          3715: **
        !          3716: ** These constant define integer codes that represent the various
        !          3717: ** text encodings supported by SQLite.
        !          3718: */
        !          3719: #define SQLITE_UTF8           1
        !          3720: #define SQLITE_UTF16LE        2
        !          3721: #define SQLITE_UTF16BE        3
        !          3722: #define SQLITE_UTF16          4    /* Use native byte order */
        !          3723: #define SQLITE_ANY            5    /* sqlite3_create_function only */
        !          3724: #define SQLITE_UTF16_ALIGNED  8    /* sqlite3_create_collation only */
        !          3725: 
        !          3726: /*
        !          3727: ** CAPI3REF: Deprecated Functions
        !          3728: ** DEPRECATED
        !          3729: **
        !          3730: ** These functions are [deprecated].  In order to maintain
        !          3731: ** backwards compatibility with older code, these functions continue 
        !          3732: ** to be supported.  However, new applications should avoid
        !          3733: ** the use of these functions.  To help encourage people to avoid
        !          3734: ** using these functions, we are not going to tell you what they do.
        !          3735: */
        !          3736: #ifndef SQLITE_OMIT_DEPRECATED
        !          3737: SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*);
        !          3738: SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*);
        !          3739: SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
        !          3740: SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void);
        !          3741: SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void);
        !          3742: SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),void*,sqlite3_int64);
        !          3743: #endif
        !          3744: 
        !          3745: /*
        !          3746: ** CAPI3REF: Obtaining SQL Function Parameter Values
        !          3747: **
        !          3748: ** The C-language implementation of SQL functions and aggregates uses
        !          3749: ** this set of interface routines to access the parameter values on
        !          3750: ** the function or aggregate.
        !          3751: **
        !          3752: ** The xFunc (for scalar functions) or xStep (for aggregates) parameters
        !          3753: ** to [sqlite3_create_function()] and [sqlite3_create_function16()]
        !          3754: ** define callbacks that implement the SQL functions and aggregates.
        !          3755: ** The 3rd parameter to these callbacks is an array of pointers to
        !          3756: ** [protected sqlite3_value] objects.  There is one [sqlite3_value] object for
        !          3757: ** each parameter to the SQL function.  These routines are used to
        !          3758: ** extract values from the [sqlite3_value] objects.
        !          3759: **
        !          3760: ** These routines work only with [protected sqlite3_value] objects.
        !          3761: ** Any attempt to use these routines on an [unprotected sqlite3_value]
        !          3762: ** object results in undefined behavior.
        !          3763: **
        !          3764: ** ^These routines work just like the corresponding [column access functions]
        !          3765: ** except that  these routines take a single [protected sqlite3_value] object
        !          3766: ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
        !          3767: **
        !          3768: ** ^The sqlite3_value_text16() interface extracts a UTF-16 string
        !          3769: ** in the native byte-order of the host machine.  ^The
        !          3770: ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
        !          3771: ** extract UTF-16 strings as big-endian and little-endian respectively.
        !          3772: **
        !          3773: ** ^(The sqlite3_value_numeric_type() interface attempts to apply
        !          3774: ** numeric affinity to the value.  This means that an attempt is
        !          3775: ** made to convert the value to an integer or floating point.  If
        !          3776: ** such a conversion is possible without loss of information (in other
        !          3777: ** words, if the value is a string that looks like a number)
        !          3778: ** then the conversion is performed.  Otherwise no conversion occurs.
        !          3779: ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
        !          3780: **
        !          3781: ** Please pay particular attention to the fact that the pointer returned
        !          3782: ** from [sqlite3_value_blob()], [sqlite3_value_text()], or
        !          3783: ** [sqlite3_value_text16()] can be invalidated by a subsequent call to
        !          3784: ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
        !          3785: ** or [sqlite3_value_text16()].
        !          3786: **
        !          3787: ** These routines must be called from the same thread as
        !          3788: ** the SQL function that supplied the [sqlite3_value*] parameters.
        !          3789: */
        !          3790: SQLITE_API const void *sqlite3_value_blob(sqlite3_value*);
        !          3791: SQLITE_API int sqlite3_value_bytes(sqlite3_value*);
        !          3792: SQLITE_API int sqlite3_value_bytes16(sqlite3_value*);
        !          3793: SQLITE_API double sqlite3_value_double(sqlite3_value*);
        !          3794: SQLITE_API int sqlite3_value_int(sqlite3_value*);
        !          3795: SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
        !          3796: SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*);
        !          3797: SQLITE_API const void *sqlite3_value_text16(sqlite3_value*);
        !          3798: SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*);
        !          3799: SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*);
        !          3800: SQLITE_API int sqlite3_value_type(sqlite3_value*);
        !          3801: SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*);
        !          3802: 
        !          3803: /*
        !          3804: ** CAPI3REF: Obtain Aggregate Function Context
        !          3805: **
        !          3806: ** Implementations of aggregate SQL functions use this
        !          3807: ** routine to allocate memory for storing their state.
        !          3808: **
        !          3809: ** ^The first time the sqlite3_aggregate_context(C,N) routine is called 
        !          3810: ** for a particular aggregate function, SQLite
        !          3811: ** allocates N of memory, zeroes out that memory, and returns a pointer
        !          3812: ** to the new memory. ^On second and subsequent calls to
        !          3813: ** sqlite3_aggregate_context() for the same aggregate function instance,
        !          3814: ** the same buffer is returned.  Sqlite3_aggregate_context() is normally
        !          3815: ** called once for each invocation of the xStep callback and then one
        !          3816: ** last time when the xFinal callback is invoked.  ^(When no rows match
        !          3817: ** an aggregate query, the xStep() callback of the aggregate function
        !          3818: ** implementation is never called and xFinal() is called exactly once.
        !          3819: ** In those cases, sqlite3_aggregate_context() might be called for the
        !          3820: ** first time from within xFinal().)^
        !          3821: **
        !          3822: ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer if N is
        !          3823: ** less than or equal to zero or if a memory allocate error occurs.
        !          3824: **
        !          3825: ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
        !          3826: ** determined by the N parameter on first successful call.  Changing the
        !          3827: ** value of N in subsequent call to sqlite3_aggregate_context() within
        !          3828: ** the same aggregate function instance will not resize the memory
        !          3829: ** allocation.)^
        !          3830: **
        !          3831: ** ^SQLite automatically frees the memory allocated by 
        !          3832: ** sqlite3_aggregate_context() when the aggregate query concludes.
        !          3833: **
        !          3834: ** The first parameter must be a copy of the
        !          3835: ** [sqlite3_context | SQL function context] that is the first parameter
        !          3836: ** to the xStep or xFinal callback routine that implements the aggregate
        !          3837: ** function.
        !          3838: **
        !          3839: ** This routine must be called from the same thread in which
        !          3840: ** the aggregate SQL function is running.
        !          3841: */
        !          3842: SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
        !          3843: 
        !          3844: /*
        !          3845: ** CAPI3REF: User Data For Functions
        !          3846: **
        !          3847: ** ^The sqlite3_user_data() interface returns a copy of
        !          3848: ** the pointer that was the pUserData parameter (the 5th parameter)
        !          3849: ** of the [sqlite3_create_function()]
        !          3850: ** and [sqlite3_create_function16()] routines that originally
        !          3851: ** registered the application defined function.
        !          3852: **
        !          3853: ** This routine must be called from the same thread in which
        !          3854: ** the application-defined function is running.
        !          3855: */
        !          3856: SQLITE_API void *sqlite3_user_data(sqlite3_context*);
        !          3857: 
        !          3858: /*
        !          3859: ** CAPI3REF: Database Connection For Functions
        !          3860: **
        !          3861: ** ^The sqlite3_context_db_handle() interface returns a copy of
        !          3862: ** the pointer to the [database connection] (the 1st parameter)
        !          3863: ** of the [sqlite3_create_function()]
        !          3864: ** and [sqlite3_create_function16()] routines that originally
        !          3865: ** registered the application defined function.
        !          3866: */
        !          3867: SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*);
        !          3868: 
        !          3869: /*
        !          3870: ** CAPI3REF: Function Auxiliary Data
        !          3871: **
        !          3872: ** The following two functions may be used by scalar SQL functions to
        !          3873: ** associate metadata with argument values. If the same value is passed to
        !          3874: ** multiple invocations of the same SQL function during query execution, under
        !          3875: ** some circumstances the associated metadata may be preserved. This may
        !          3876: ** be used, for example, to add a regular-expression matching scalar
        !          3877: ** function. The compiled version of the regular expression is stored as
        !          3878: ** metadata associated with the SQL value passed as the regular expression
        !          3879: ** pattern.  The compiled regular expression can be reused on multiple
        !          3880: ** invocations of the same function so that the original pattern string
        !          3881: ** does not need to be recompiled on each invocation.
        !          3882: **
        !          3883: ** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata
        !          3884: ** associated by the sqlite3_set_auxdata() function with the Nth argument
        !          3885: ** value to the application-defined function. ^If no metadata has been ever
        !          3886: ** been set for the Nth argument of the function, or if the corresponding
        !          3887: ** function parameter has changed since the meta-data was set,
        !          3888: ** then sqlite3_get_auxdata() returns a NULL pointer.
        !          3889: **
        !          3890: ** ^The sqlite3_set_auxdata() interface saves the metadata
        !          3891: ** pointed to by its 3rd parameter as the metadata for the N-th
        !          3892: ** argument of the application-defined function.  Subsequent
        !          3893: ** calls to sqlite3_get_auxdata() might return this data, if it has
        !          3894: ** not been destroyed.
        !          3895: ** ^If it is not NULL, SQLite will invoke the destructor
        !          3896: ** function given by the 4th parameter to sqlite3_set_auxdata() on
        !          3897: ** the metadata when the corresponding function parameter changes
        !          3898: ** or when the SQL statement completes, whichever comes first.
        !          3899: **
        !          3900: ** SQLite is free to call the destructor and drop metadata on any
        !          3901: ** parameter of any function at any time.  ^The only guarantee is that
        !          3902: ** the destructor will be called before the metadata is dropped.
        !          3903: **
        !          3904: ** ^(In practice, metadata is preserved between function calls for
        !          3905: ** expressions that are constant at compile time. This includes literal
        !          3906: ** values and [parameters].)^
        !          3907: **
        !          3908: ** These routines must be called from the same thread in which
        !          3909: ** the SQL function is running.
        !          3910: */
        !          3911: SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N);
        !          3912: SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));
        !          3913: 
        !          3914: 
        !          3915: /*
        !          3916: ** CAPI3REF: Constants Defining Special Destructor Behavior
        !          3917: **
        !          3918: ** These are special values for the destructor that is passed in as the
        !          3919: ** final argument to routines like [sqlite3_result_blob()].  ^If the destructor
        !          3920: ** argument is SQLITE_STATIC, it means that the content pointer is constant
        !          3921: ** and will never change.  It does not need to be destroyed.  ^The
        !          3922: ** SQLITE_TRANSIENT value means that the content will likely change in
        !          3923: ** the near future and that SQLite should make its own private copy of
        !          3924: ** the content before returning.
        !          3925: **
        !          3926: ** The typedef is necessary to work around problems in certain
        !          3927: ** C++ compilers.  See ticket #2191.
        !          3928: */
        !          3929: typedef void (*sqlite3_destructor_type)(void*);
        !          3930: #define SQLITE_STATIC      ((sqlite3_destructor_type)0)
        !          3931: #define SQLITE_TRANSIENT   ((sqlite3_destructor_type)-1)
        !          3932: 
        !          3933: /*
        !          3934: ** CAPI3REF: Setting The Result Of An SQL Function
        !          3935: **
        !          3936: ** These routines are used by the xFunc or xFinal callbacks that
        !          3937: ** implement SQL functions and aggregates.  See
        !          3938: ** [sqlite3_create_function()] and [sqlite3_create_function16()]
        !          3939: ** for additional information.
        !          3940: **
        !          3941: ** These functions work very much like the [parameter binding] family of
        !          3942: ** functions used to bind values to host parameters in prepared statements.
        !          3943: ** Refer to the [SQL parameter] documentation for additional information.
        !          3944: **
        !          3945: ** ^The sqlite3_result_blob() interface sets the result from
        !          3946: ** an application-defined function to be the BLOB whose content is pointed
        !          3947: ** to by the second parameter and which is N bytes long where N is the
        !          3948: ** third parameter.
        !          3949: **
        !          3950: ** ^The sqlite3_result_zeroblob() interfaces set the result of
        !          3951: ** the application-defined function to be a BLOB containing all zero
        !          3952: ** bytes and N bytes in size, where N is the value of the 2nd parameter.
        !          3953: **
        !          3954: ** ^The sqlite3_result_double() interface sets the result from
        !          3955: ** an application-defined function to be a floating point value specified
        !          3956: ** by its 2nd argument.
        !          3957: **
        !          3958: ** ^The sqlite3_result_error() and sqlite3_result_error16() functions
        !          3959: ** cause the implemented SQL function to throw an exception.
        !          3960: ** ^SQLite uses the string pointed to by the
        !          3961: ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
        !          3962: ** as the text of an error message.  ^SQLite interprets the error
        !          3963: ** message string from sqlite3_result_error() as UTF-8. ^SQLite
        !          3964: ** interprets the string from sqlite3_result_error16() as UTF-16 in native
        !          3965: ** byte order.  ^If the third parameter to sqlite3_result_error()
        !          3966: ** or sqlite3_result_error16() is negative then SQLite takes as the error
        !          3967: ** message all text up through the first zero character.
        !          3968: ** ^If the third parameter to sqlite3_result_error() or
        !          3969: ** sqlite3_result_error16() is non-negative then SQLite takes that many
        !          3970: ** bytes (not characters) from the 2nd parameter as the error message.
        !          3971: ** ^The sqlite3_result_error() and sqlite3_result_error16()
        !          3972: ** routines make a private copy of the error message text before
        !          3973: ** they return.  Hence, the calling function can deallocate or
        !          3974: ** modify the text after they return without harm.
        !          3975: ** ^The sqlite3_result_error_code() function changes the error code
        !          3976: ** returned by SQLite as a result of an error in a function.  ^By default,
        !          3977: ** the error code is SQLITE_ERROR.  ^A subsequent call to sqlite3_result_error()
        !          3978: ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
        !          3979: **
        !          3980: ** ^The sqlite3_result_toobig() interface causes SQLite to throw an error
        !          3981: ** indicating that a string or BLOB is too long to represent.
        !          3982: **
        !          3983: ** ^The sqlite3_result_nomem() interface causes SQLite to throw an error
        !          3984: ** indicating that a memory allocation failed.
        !          3985: **
        !          3986: ** ^The sqlite3_result_int() interface sets the return value
        !          3987: ** of the application-defined function to be the 32-bit signed integer
        !          3988: ** value given in the 2nd argument.
        !          3989: ** ^The sqlite3_result_int64() interface sets the return value
        !          3990: ** of the application-defined function to be the 64-bit signed integer
        !          3991: ** value given in the 2nd argument.
        !          3992: **
        !          3993: ** ^The sqlite3_result_null() interface sets the return value
        !          3994: ** of the application-defined function to be NULL.
        !          3995: **
        !          3996: ** ^The sqlite3_result_text(), sqlite3_result_text16(),
        !          3997: ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
        !          3998: ** set the return value of the application-defined function to be
        !          3999: ** a text string which is represented as UTF-8, UTF-16 native byte order,
        !          4000: ** UTF-16 little endian, or UTF-16 big endian, respectively.
        !          4001: ** ^SQLite takes the text result from the application from
        !          4002: ** the 2nd parameter of the sqlite3_result_text* interfaces.
        !          4003: ** ^If the 3rd parameter to the sqlite3_result_text* interfaces
        !          4004: ** is negative, then SQLite takes result text from the 2nd parameter
        !          4005: ** through the first zero character.
        !          4006: ** ^If the 3rd parameter to the sqlite3_result_text* interfaces
        !          4007: ** is non-negative, then as many bytes (not characters) of the text
        !          4008: ** pointed to by the 2nd parameter are taken as the application-defined
        !          4009: ** function result.
        !          4010: ** ^If the 4th parameter to the sqlite3_result_text* interfaces
        !          4011: ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
        !          4012: ** function as the destructor on the text or BLOB result when it has
        !          4013: ** finished using that result.
        !          4014: ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to
        !          4015: ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
        !          4016: ** assumes that the text or BLOB result is in constant space and does not
        !          4017: ** copy the content of the parameter nor call a destructor on the content
        !          4018: ** when it has finished using that result.
        !          4019: ** ^If the 4th parameter to the sqlite3_result_text* interfaces
        !          4020: ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
        !          4021: ** then SQLite makes a copy of the result into space obtained from
        !          4022: ** from [sqlite3_malloc()] before it returns.
        !          4023: **
        !          4024: ** ^The sqlite3_result_value() interface sets the result of
        !          4025: ** the application-defined function to be a copy the
        !          4026: ** [unprotected sqlite3_value] object specified by the 2nd parameter.  ^The
        !          4027: ** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
        !          4028: ** so that the [sqlite3_value] specified in the parameter may change or
        !          4029: ** be deallocated after sqlite3_result_value() returns without harm.
        !          4030: ** ^A [protected sqlite3_value] object may always be used where an
        !          4031: ** [unprotected sqlite3_value] object is required, so either
        !          4032: ** kind of [sqlite3_value] object can be used with this interface.
        !          4033: **
        !          4034: ** If these routines are called from within the different thread
        !          4035: ** than the one containing the application-defined function that received
        !          4036: ** the [sqlite3_context] pointer, the results are undefined.
        !          4037: */
        !          4038: SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
        !          4039: SQLITE_API void sqlite3_result_double(sqlite3_context*, double);
        !          4040: SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int);
        !          4041: SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int);
        !          4042: SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*);
        !          4043: SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*);
        !          4044: SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int);
        !          4045: SQLITE_API void sqlite3_result_int(sqlite3_context*, int);
        !          4046: SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
        !          4047: SQLITE_API void sqlite3_result_null(sqlite3_context*);
        !          4048: SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
        !          4049: SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
        !          4050: SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
        !          4051: SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
        !          4052: SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
        !          4053: SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n);
        !          4054: 
        !          4055: /*
        !          4056: ** CAPI3REF: Define New Collating Sequences
        !          4057: **
        !          4058: ** ^These functions add, remove, or modify a [collation] associated
        !          4059: ** with the [database connection] specified as the first argument.
        !          4060: **
        !          4061: ** ^The name of the collation is a UTF-8 string
        !          4062: ** for sqlite3_create_collation() and sqlite3_create_collation_v2()
        !          4063: ** and a UTF-16 string in native byte order for sqlite3_create_collation16().
        !          4064: ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are
        !          4065: ** considered to be the same name.
        !          4066: **
        !          4067: ** ^(The third argument (eTextRep) must be one of the constants:
        !          4068: ** <ul>
        !          4069: ** <li> [SQLITE_UTF8],
        !          4070: ** <li> [SQLITE_UTF16LE],
        !          4071: ** <li> [SQLITE_UTF16BE],
        !          4072: ** <li> [SQLITE_UTF16], or
        !          4073: ** <li> [SQLITE_UTF16_ALIGNED].
        !          4074: ** </ul>)^
        !          4075: ** ^The eTextRep argument determines the encoding of strings passed
        !          4076: ** to the collating function callback, xCallback.
        !          4077: ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep
        !          4078: ** force strings to be UTF16 with native byte order.
        !          4079: ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin
        !          4080: ** on an even byte address.
        !          4081: **
        !          4082: ** ^The fourth argument, pArg, is an application data pointer that is passed
        !          4083: ** through as the first argument to the collating function callback.
        !          4084: **
        !          4085: ** ^The fifth argument, xCallback, is a pointer to the collating function.
        !          4086: ** ^Multiple collating functions can be registered using the same name but
        !          4087: ** with different eTextRep parameters and SQLite will use whichever
        !          4088: ** function requires the least amount of data transformation.
        !          4089: ** ^If the xCallback argument is NULL then the collating function is
        !          4090: ** deleted.  ^When all collating functions having the same name are deleted,
        !          4091: ** that collation is no longer usable.
        !          4092: **
        !          4093: ** ^The collating function callback is invoked with a copy of the pArg 
        !          4094: ** application data pointer and with two strings in the encoding specified
        !          4095: ** by the eTextRep argument.  The collating function must return an
        !          4096: ** integer that is negative, zero, or positive
        !          4097: ** if the first string is less than, equal to, or greater than the second,
        !          4098: ** respectively.  A collating function must always return the same answer
        !          4099: ** given the same inputs.  If two or more collating functions are registered
        !          4100: ** to the same collation name (using different eTextRep values) then all
        !          4101: ** must give an equivalent answer when invoked with equivalent strings.
        !          4102: ** The collating function must obey the following properties for all
        !          4103: ** strings A, B, and C:
        !          4104: **
        !          4105: ** <ol>
        !          4106: ** <li> If A==B then B==A.
        !          4107: ** <li> If A==B and B==C then A==C.
        !          4108: ** <li> If A&lt;B THEN B&gt;A.
        !          4109: ** <li> If A&lt;B and B&lt;C then A&lt;C.
        !          4110: ** </ol>
        !          4111: **
        !          4112: ** If a collating function fails any of the above constraints and that
        !          4113: ** collating function is  registered and used, then the behavior of SQLite
        !          4114: ** is undefined.
        !          4115: **
        !          4116: ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()
        !          4117: ** with the addition that the xDestroy callback is invoked on pArg when
        !          4118: ** the collating function is deleted.
        !          4119: ** ^Collating functions are deleted when they are overridden by later
        !          4120: ** calls to the collation creation functions or when the
        !          4121: ** [database connection] is closed using [sqlite3_close()].
        !          4122: **
        !          4123: ** ^The xDestroy callback is <u>not</u> called if the 
        !          4124: ** sqlite3_create_collation_v2() function fails.  Applications that invoke
        !          4125: ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 
        !          4126: ** check the return code and dispose of the application data pointer
        !          4127: ** themselves rather than expecting SQLite to deal with it for them.
        !          4128: ** This is different from every other SQLite interface.  The inconsistency 
        !          4129: ** is unfortunate but cannot be changed without breaking backwards 
        !          4130: ** compatibility.
        !          4131: **
        !          4132: ** See also:  [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
        !          4133: */
        !          4134: SQLITE_API int sqlite3_create_collation(
        !          4135:   sqlite3*, 
        !          4136:   const char *zName, 
        !          4137:   int eTextRep, 
        !          4138:   void *pArg,
        !          4139:   int(*xCompare)(void*,int,const void*,int,const void*)
        !          4140: );
        !          4141: SQLITE_API int sqlite3_create_collation_v2(
        !          4142:   sqlite3*, 
        !          4143:   const char *zName, 
        !          4144:   int eTextRep, 
        !          4145:   void *pArg,
        !          4146:   int(*xCompare)(void*,int,const void*,int,const void*),
        !          4147:   void(*xDestroy)(void*)
        !          4148: );
        !          4149: SQLITE_API int sqlite3_create_collation16(
        !          4150:   sqlite3*, 
        !          4151:   const void *zName,
        !          4152:   int eTextRep, 
        !          4153:   void *pArg,
        !          4154:   int(*xCompare)(void*,int,const void*,int,const void*)
        !          4155: );
        !          4156: 
        !          4157: /*
        !          4158: ** CAPI3REF: Collation Needed Callbacks
        !          4159: **
        !          4160: ** ^To avoid having to register all collation sequences before a database
        !          4161: ** can be used, a single callback function may be registered with the
        !          4162: ** [database connection] to be invoked whenever an undefined collation
        !          4163: ** sequence is required.
        !          4164: **
        !          4165: ** ^If the function is registered using the sqlite3_collation_needed() API,
        !          4166: ** then it is passed the names of undefined collation sequences as strings
        !          4167: ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,
        !          4168: ** the names are passed as UTF-16 in machine native byte order.
        !          4169: ** ^A call to either function replaces the existing collation-needed callback.
        !          4170: **
        !          4171: ** ^(When the callback is invoked, the first argument passed is a copy
        !          4172: ** of the second argument to sqlite3_collation_needed() or
        !          4173: ** sqlite3_collation_needed16().  The second argument is the database
        !          4174: ** connection.  The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
        !          4175: ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
        !          4176: ** sequence function required.  The fourth parameter is the name of the
        !          4177: ** required collation sequence.)^
        !          4178: **
        !          4179: ** The callback function should register the desired collation using
        !          4180: ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
        !          4181: ** [sqlite3_create_collation_v2()].
        !          4182: */
        !          4183: SQLITE_API int sqlite3_collation_needed(
        !          4184:   sqlite3*, 
        !          4185:   void*, 
        !          4186:   void(*)(void*,sqlite3*,int eTextRep,const char*)
        !          4187: );
        !          4188: SQLITE_API int sqlite3_collation_needed16(
        !          4189:   sqlite3*, 
        !          4190:   void*,
        !          4191:   void(*)(void*,sqlite3*,int eTextRep,const void*)
        !          4192: );
        !          4193: 
        !          4194: #ifdef SQLITE_HAS_CODEC
        !          4195: /*
        !          4196: ** Specify the key for an encrypted database.  This routine should be
        !          4197: ** called right after sqlite3_open().
        !          4198: **
        !          4199: ** The code to implement this API is not available in the public release
        !          4200: ** of SQLite.
        !          4201: */
        !          4202: SQLITE_API int sqlite3_key(
        !          4203:   sqlite3 *db,                   /* Database to be rekeyed */
        !          4204:   const void *pKey, int nKey     /* The key */
        !          4205: );
        !          4206: 
        !          4207: /*
        !          4208: ** Change the key on an open database.  If the current database is not
        !          4209: ** encrypted, this routine will encrypt it.  If pNew==0 or nNew==0, the
        !          4210: ** database is decrypted.
        !          4211: **
        !          4212: ** The code to implement this API is not available in the public release
        !          4213: ** of SQLite.
        !          4214: */
        !          4215: SQLITE_API int sqlite3_rekey(
        !          4216:   sqlite3 *db,                   /* Database to be rekeyed */
        !          4217:   const void *pKey, int nKey     /* The new key */
        !          4218: );
        !          4219: 
        !          4220: /*
        !          4221: ** Specify the activation key for a SEE database.  Unless 
        !          4222: ** activated, none of the SEE routines will work.
        !          4223: */
        !          4224: SQLITE_API void sqlite3_activate_see(
        !          4225:   const char *zPassPhrase        /* Activation phrase */
        !          4226: );
        !          4227: #endif
        !          4228: 
        !          4229: #ifdef SQLITE_ENABLE_CEROD
        !          4230: /*
        !          4231: ** Specify the activation key for a CEROD database.  Unless 
        !          4232: ** activated, none of the CEROD routines will work.
        !          4233: */
        !          4234: SQLITE_API void sqlite3_activate_cerod(
        !          4235:   const char *zPassPhrase        /* Activation phrase */
        !          4236: );
        !          4237: #endif
        !          4238: 
        !          4239: /*
        !          4240: ** CAPI3REF: Suspend Execution For A Short Time
        !          4241: **
        !          4242: ** The sqlite3_sleep() function causes the current thread to suspend execution
        !          4243: ** for at least a number of milliseconds specified in its parameter.
        !          4244: **
        !          4245: ** If the operating system does not support sleep requests with
        !          4246: ** millisecond time resolution, then the time will be rounded up to
        !          4247: ** the nearest second. The number of milliseconds of sleep actually
        !          4248: ** requested from the operating system is returned.
        !          4249: **
        !          4250: ** ^SQLite implements this interface by calling the xSleep()
        !          4251: ** method of the default [sqlite3_vfs] object.  If the xSleep() method
        !          4252: ** of the default VFS is not implemented correctly, or not implemented at
        !          4253: ** all, then the behavior of sqlite3_sleep() may deviate from the description
        !          4254: ** in the previous paragraphs.
        !          4255: */
        !          4256: SQLITE_API int sqlite3_sleep(int);
        !          4257: 
        !          4258: /*
        !          4259: ** CAPI3REF: Name Of The Folder Holding Temporary Files
        !          4260: **
        !          4261: ** ^(If this global variable is made to point to a string which is
        !          4262: ** the name of a folder (a.k.a. directory), then all temporary files
        !          4263: ** created by SQLite when using a built-in [sqlite3_vfs | VFS]
        !          4264: ** will be placed in that directory.)^  ^If this variable
        !          4265: ** is a NULL pointer, then SQLite performs a search for an appropriate
        !          4266: ** temporary file directory.
        !          4267: **
        !          4268: ** It is not safe to read or modify this variable in more than one
        !          4269: ** thread at a time.  It is not safe to read or modify this variable
        !          4270: ** if a [database connection] is being used at the same time in a separate
        !          4271: ** thread.
        !          4272: ** It is intended that this variable be set once
        !          4273: ** as part of process initialization and before any SQLite interface
        !          4274: ** routines have been called and that this variable remain unchanged
        !          4275: ** thereafter.
        !          4276: **
        !          4277: ** ^The [temp_store_directory pragma] may modify this variable and cause
        !          4278: ** it to point to memory obtained from [sqlite3_malloc].  ^Furthermore,
        !          4279: ** the [temp_store_directory pragma] always assumes that any string
        !          4280: ** that this variable points to is held in memory obtained from 
        !          4281: ** [sqlite3_malloc] and the pragma may attempt to free that memory
        !          4282: ** using [sqlite3_free].
        !          4283: ** Hence, if this variable is modified directly, either it should be
        !          4284: ** made NULL or made to point to memory obtained from [sqlite3_malloc]
        !          4285: ** or else the use of the [temp_store_directory pragma] should be avoided.
        !          4286: */
        !          4287: SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory;
        !          4288: 
        !          4289: /*
        !          4290: ** CAPI3REF: Test For Auto-Commit Mode
        !          4291: ** KEYWORDS: {autocommit mode}
        !          4292: **
        !          4293: ** ^The sqlite3_get_autocommit() interface returns non-zero or
        !          4294: ** zero if the given database connection is or is not in autocommit mode,
        !          4295: ** respectively.  ^Autocommit mode is on by default.
        !          4296: ** ^Autocommit mode is disabled by a [BEGIN] statement.
        !          4297: ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
        !          4298: **
        !          4299: ** If certain kinds of errors occur on a statement within a multi-statement
        !          4300: ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
        !          4301: ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
        !          4302: ** transaction might be rolled back automatically.  The only way to
        !          4303: ** find out whether SQLite automatically rolled back the transaction after
        !          4304: ** an error is to use this function.
        !          4305: **
        !          4306: ** If another thread changes the autocommit status of the database
        !          4307: ** connection while this routine is running, then the return value
        !          4308: ** is undefined.
        !          4309: */
        !          4310: SQLITE_API int sqlite3_get_autocommit(sqlite3*);
        !          4311: 
        !          4312: /*
        !          4313: ** CAPI3REF: Find The Database Handle Of A Prepared Statement
        !          4314: **
        !          4315: ** ^The sqlite3_db_handle interface returns the [database connection] handle
        !          4316: ** to which a [prepared statement] belongs.  ^The [database connection]
        !          4317: ** returned by sqlite3_db_handle is the same [database connection]
        !          4318: ** that was the first argument
        !          4319: ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
        !          4320: ** create the statement in the first place.
        !          4321: */
        !          4322: SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
        !          4323: 
        !          4324: /*
        !          4325: ** CAPI3REF: Find the next prepared statement
        !          4326: **
        !          4327: ** ^This interface returns a pointer to the next [prepared statement] after
        !          4328: ** pStmt associated with the [database connection] pDb.  ^If pStmt is NULL
        !          4329: ** then this interface returns a pointer to the first prepared statement
        !          4330: ** associated with the database connection pDb.  ^If no prepared statement
        !          4331: ** satisfies the conditions of this routine, it returns NULL.
        !          4332: **
        !          4333: ** The [database connection] pointer D in a call to
        !          4334: ** [sqlite3_next_stmt(D,S)] must refer to an open database
        !          4335: ** connection and in particular must not be a NULL pointer.
        !          4336: */
        !          4337: SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);
        !          4338: 
        !          4339: /*
        !          4340: ** CAPI3REF: Commit And Rollback Notification Callbacks
        !          4341: **
        !          4342: ** ^The sqlite3_commit_hook() interface registers a callback
        !          4343: ** function to be invoked whenever a transaction is [COMMIT | committed].
        !          4344: ** ^Any callback set by a previous call to sqlite3_commit_hook()
        !          4345: ** for the same database connection is overridden.
        !          4346: ** ^The sqlite3_rollback_hook() interface registers a callback
        !          4347: ** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
        !          4348: ** ^Any callback set by a previous call to sqlite3_rollback_hook()
        !          4349: ** for the same database connection is overridden.
        !          4350: ** ^The pArg argument is passed through to the callback.
        !          4351: ** ^If the callback on a commit hook function returns non-zero,
        !          4352: ** then the commit is converted into a rollback.
        !          4353: **
        !          4354: ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
        !          4355: ** return the P argument from the previous call of the same function
        !          4356: ** on the same [database connection] D, or NULL for
        !          4357: ** the first call for each function on D.
        !          4358: **
        !          4359: ** The callback implementation must not do anything that will modify
        !          4360: ** the database connection that invoked the callback.  Any actions
        !          4361: ** to modify the database connection must be deferred until after the
        !          4362: ** completion of the [sqlite3_step()] call that triggered the commit
        !          4363: ** or rollback hook in the first place.
        !          4364: ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
        !          4365: ** database connections for the meaning of "modify" in this paragraph.
        !          4366: **
        !          4367: ** ^Registering a NULL function disables the callback.
        !          4368: **
        !          4369: ** ^When the commit hook callback routine returns zero, the [COMMIT]
        !          4370: ** operation is allowed to continue normally.  ^If the commit hook
        !          4371: ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
        !          4372: ** ^The rollback hook is invoked on a rollback that results from a commit
        !          4373: ** hook returning non-zero, just as it would be with any other rollback.
        !          4374: **
        !          4375: ** ^For the purposes of this API, a transaction is said to have been
        !          4376: ** rolled back if an explicit "ROLLBACK" statement is executed, or
        !          4377: ** an error or constraint causes an implicit rollback to occur.
        !          4378: ** ^The rollback callback is not invoked if a transaction is
        !          4379: ** automatically rolled back because the database connection is closed.
        !          4380: **
        !          4381: ** See also the [sqlite3_update_hook()] interface.
        !          4382: */
        !          4383: SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
        !          4384: SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
        !          4385: 
        !          4386: /*
        !          4387: ** CAPI3REF: Data Change Notification Callbacks
        !          4388: **
        !          4389: ** ^The sqlite3_update_hook() interface registers a callback function
        !          4390: ** with the [database connection] identified by the first argument
        !          4391: ** to be invoked whenever a row is updated, inserted or deleted.
        !          4392: ** ^Any callback set by a previous call to this function
        !          4393: ** for the same database connection is overridden.
        !          4394: **
        !          4395: ** ^The second argument is a pointer to the function to invoke when a
        !          4396: ** row is updated, inserted or deleted.
        !          4397: ** ^The first argument to the callback is a copy of the third argument
        !          4398: ** to sqlite3_update_hook().
        !          4399: ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
        !          4400: ** or [SQLITE_UPDATE], depending on the operation that caused the callback
        !          4401: ** to be invoked.
        !          4402: ** ^The third and fourth arguments to the callback contain pointers to the
        !          4403: ** database and table name containing the affected row.
        !          4404: ** ^The final callback parameter is the [rowid] of the row.
        !          4405: ** ^In the case of an update, this is the [rowid] after the update takes place.
        !          4406: **
        !          4407: ** ^(The update hook is not invoked when internal system tables are
        !          4408: ** modified (i.e. sqlite_master and sqlite_sequence).)^
        !          4409: **
        !          4410: ** ^In the current implementation, the update hook
        !          4411: ** is not invoked when duplication rows are deleted because of an
        !          4412: ** [ON CONFLICT | ON CONFLICT REPLACE] clause.  ^Nor is the update hook
        !          4413: ** invoked when rows are deleted using the [truncate optimization].
        !          4414: ** The exceptions defined in this paragraph might change in a future
        !          4415: ** release of SQLite.
        !          4416: **
        !          4417: ** The update hook implementation must not do anything that will modify
        !          4418: ** the database connection that invoked the update hook.  Any actions
        !          4419: ** to modify the database connection must be deferred until after the
        !          4420: ** completion of the [sqlite3_step()] call that triggered the update hook.
        !          4421: ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
        !          4422: ** database connections for the meaning of "modify" in this paragraph.
        !          4423: **
        !          4424: ** ^The sqlite3_update_hook(D,C,P) function
        !          4425: ** returns the P argument from the previous call
        !          4426: ** on the same [database connection] D, or NULL for
        !          4427: ** the first call on D.
        !          4428: **
        !          4429: ** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()]
        !          4430: ** interfaces.
        !          4431: */
        !          4432: SQLITE_API void *sqlite3_update_hook(
        !          4433:   sqlite3*, 
        !          4434:   void(*)(void *,int ,char const *,char const *,sqlite3_int64),
        !          4435:   void*
        !          4436: );
        !          4437: 
        !          4438: /*
        !          4439: ** CAPI3REF: Enable Or Disable Shared Pager Cache
        !          4440: ** KEYWORDS: {shared cache}
        !          4441: **
        !          4442: ** ^(This routine enables or disables the sharing of the database cache
        !          4443: ** and schema data structures between [database connection | connections]
        !          4444: ** to the same database. Sharing is enabled if the argument is true
        !          4445: ** and disabled if the argument is false.)^
        !          4446: **
        !          4447: ** ^Cache sharing is enabled and disabled for an entire process.
        !          4448: ** This is a change as of SQLite version 3.5.0. In prior versions of SQLite,
        !          4449: ** sharing was enabled or disabled for each thread separately.
        !          4450: **
        !          4451: ** ^(The cache sharing mode set by this interface effects all subsequent
        !          4452: ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
        !          4453: ** Existing database connections continue use the sharing mode
        !          4454: ** that was in effect at the time they were opened.)^
        !          4455: **
        !          4456: ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
        !          4457: ** successfully.  An [error code] is returned otherwise.)^
        !          4458: **
        !          4459: ** ^Shared cache is disabled by default. But this might change in
        !          4460: ** future releases of SQLite.  Applications that care about shared
        !          4461: ** cache setting should set it explicitly.
        !          4462: **
        !          4463: ** See Also:  [SQLite Shared-Cache Mode]
        !          4464: */
        !          4465: SQLITE_API int sqlite3_enable_shared_cache(int);
        !          4466: 
        !          4467: /*
        !          4468: ** CAPI3REF: Attempt To Free Heap Memory
        !          4469: **
        !          4470: ** ^The sqlite3_release_memory() interface attempts to free N bytes
        !          4471: ** of heap memory by deallocating non-essential memory allocations
        !          4472: ** held by the database library.   Memory used to cache database
        !          4473: ** pages to improve performance is an example of non-essential memory.
        !          4474: ** ^sqlite3_release_memory() returns the number of bytes actually freed,
        !          4475: ** which might be more or less than the amount requested.
        !          4476: ** ^The sqlite3_release_memory() routine is a no-op returning zero
        !          4477: ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT].
        !          4478: */
        !          4479: SQLITE_API int sqlite3_release_memory(int);
        !          4480: 
        !          4481: /*
        !          4482: ** CAPI3REF: Impose A Limit On Heap Size
        !          4483: **
        !          4484: ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the
        !          4485: ** soft limit on the amount of heap memory that may be allocated by SQLite.
        !          4486: ** ^SQLite strives to keep heap memory utilization below the soft heap
        !          4487: ** limit by reducing the number of pages held in the page cache
        !          4488: ** as heap memory usages approaches the limit.
        !          4489: ** ^The soft heap limit is "soft" because even though SQLite strives to stay
        !          4490: ** below the limit, it will exceed the limit rather than generate
        !          4491: ** an [SQLITE_NOMEM] error.  In other words, the soft heap limit 
        !          4492: ** is advisory only.
        !          4493: **
        !          4494: ** ^The return value from sqlite3_soft_heap_limit64() is the size of
        !          4495: ** the soft heap limit prior to the call.  ^If the argument N is negative
        !          4496: ** then no change is made to the soft heap limit.  Hence, the current
        !          4497: ** size of the soft heap limit can be determined by invoking
        !          4498: ** sqlite3_soft_heap_limit64() with a negative argument.
        !          4499: **
        !          4500: ** ^If the argument N is zero then the soft heap limit is disabled.
        !          4501: **
        !          4502: ** ^(The soft heap limit is not enforced in the current implementation
        !          4503: ** if one or more of following conditions are true:
        !          4504: **
        !          4505: ** <ul>
        !          4506: ** <li> The soft heap limit is set to zero.
        !          4507: ** <li> Memory accounting is disabled using a combination of the
        !          4508: **      [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and
        !          4509: **      the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.
        !          4510: ** <li> An alternative page cache implementation is specified using
        !          4511: **      [sqlite3_config]([SQLITE_CONFIG_PCACHE],...).
        !          4512: ** <li> The page cache allocates from its own memory pool supplied
        !          4513: **      by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than
        !          4514: **      from the heap.
        !          4515: ** </ul>)^
        !          4516: **
        !          4517: ** Beginning with SQLite version 3.7.3, the soft heap limit is enforced
        !          4518: ** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT]
        !          4519: ** compile-time option is invoked.  With [SQLITE_ENABLE_MEMORY_MANAGEMENT],
        !          4520: ** the soft heap limit is enforced on every memory allocation.  Without
        !          4521: ** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced
        !          4522: ** when memory is allocated by the page cache.  Testing suggests that because
        !          4523: ** the page cache is the predominate memory user in SQLite, most
        !          4524: ** applications will achieve adequate soft heap limit enforcement without
        !          4525: ** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT].
        !          4526: **
        !          4527: ** The circumstances under which SQLite will enforce the soft heap limit may
        !          4528: ** changes in future releases of SQLite.
        !          4529: */
        !          4530: SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N);
        !          4531: 
        !          4532: /*
        !          4533: ** CAPI3REF: Deprecated Soft Heap Limit Interface
        !          4534: ** DEPRECATED
        !          4535: **
        !          4536: ** This is a deprecated version of the [sqlite3_soft_heap_limit64()]
        !          4537: ** interface.  This routine is provided for historical compatibility
        !          4538: ** only.  All new applications should use the
        !          4539: ** [sqlite3_soft_heap_limit64()] interface rather than this one.
        !          4540: */
        !          4541: SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N);
        !          4542: 
        !          4543: 
        !          4544: /*
        !          4545: ** CAPI3REF: Extract Metadata About A Column Of A Table
        !          4546: **
        !          4547: ** ^This routine returns metadata about a specific column of a specific
        !          4548: ** database table accessible using the [database connection] handle
        !          4549: ** passed as the first function argument.
        !          4550: **
        !          4551: ** ^The column is identified by the second, third and fourth parameters to
        !          4552: ** this function. ^The second parameter is either the name of the database
        !          4553: ** (i.e. "main", "temp", or an attached database) containing the specified
        !          4554: ** table or NULL. ^If it is NULL, then all attached databases are searched
        !          4555: ** for the table using the same algorithm used by the database engine to
        !          4556: ** resolve unqualified table references.
        !          4557: **
        !          4558: ** ^The third and fourth parameters to this function are the table and column
        !          4559: ** name of the desired column, respectively. Neither of these parameters
        !          4560: ** may be NULL.
        !          4561: **
        !          4562: ** ^Metadata is returned by writing to the memory locations passed as the 5th
        !          4563: ** and subsequent parameters to this function. ^Any of these arguments may be
        !          4564: ** NULL, in which case the corresponding element of metadata is omitted.
        !          4565: **
        !          4566: ** ^(<blockquote>
        !          4567: ** <table border="1">
        !          4568: ** <tr><th> Parameter <th> Output<br>Type <th>  Description
        !          4569: **
        !          4570: ** <tr><td> 5th <td> const char* <td> Data type
        !          4571: ** <tr><td> 6th <td> const char* <td> Name of default collation sequence
        !          4572: ** <tr><td> 7th <td> int         <td> True if column has a NOT NULL constraint
        !          4573: ** <tr><td> 8th <td> int         <td> True if column is part of the PRIMARY KEY
        !          4574: ** <tr><td> 9th <td> int         <td> True if column is [AUTOINCREMENT]
        !          4575: ** </table>
        !          4576: ** </blockquote>)^
        !          4577: **
        !          4578: ** ^The memory pointed to by the character pointers returned for the
        !          4579: ** declaration type and collation sequence is valid only until the next
        !          4580: ** call to any SQLite API function.
        !          4581: **
        !          4582: ** ^If the specified table is actually a view, an [error code] is returned.
        !          4583: **
        !          4584: ** ^If the specified column is "rowid", "oid" or "_rowid_" and an
        !          4585: ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
        !          4586: ** parameters are set for the explicitly declared column. ^(If there is no
        !          4587: ** explicitly declared [INTEGER PRIMARY KEY] column, then the output
        !          4588: ** parameters are set as follows:
        !          4589: **
        !          4590: ** <pre>
        !          4591: **     data type: "INTEGER"
        !          4592: **     collation sequence: "BINARY"
        !          4593: **     not null: 0
        !          4594: **     primary key: 1
        !          4595: **     auto increment: 0
        !          4596: ** </pre>)^
        !          4597: **
        !          4598: ** ^(This function may load one or more schemas from database files. If an
        !          4599: ** error occurs during this process, or if the requested table or column
        !          4600: ** cannot be found, an [error code] is returned and an error message left
        !          4601: ** in the [database connection] (to be retrieved using sqlite3_errmsg()).)^
        !          4602: **
        !          4603: ** ^This API is only available if the library was compiled with the
        !          4604: ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined.
        !          4605: */
        !          4606: SQLITE_API int sqlite3_table_column_metadata(
        !          4607:   sqlite3 *db,                /* Connection handle */
        !          4608:   const char *zDbName,        /* Database name or NULL */
        !          4609:   const char *zTableName,     /* Table name */
        !          4610:   const char *zColumnName,    /* Column name */
        !          4611:   char const **pzDataType,    /* OUTPUT: Declared data type */
        !          4612:   char const **pzCollSeq,     /* OUTPUT: Collation sequence name */
        !          4613:   int *pNotNull,              /* OUTPUT: True if NOT NULL constraint exists */
        !          4614:   int *pPrimaryKey,           /* OUTPUT: True if column part of PK */
        !          4615:   int *pAutoinc               /* OUTPUT: True if column is auto-increment */
        !          4616: );
        !          4617: 
        !          4618: /*
        !          4619: ** CAPI3REF: Load An Extension
        !          4620: **
        !          4621: ** ^This interface loads an SQLite extension library from the named file.
        !          4622: **
        !          4623: ** ^The sqlite3_load_extension() interface attempts to load an
        !          4624: ** SQLite extension library contained in the file zFile.
        !          4625: **
        !          4626: ** ^The entry point is zProc.
        !          4627: ** ^zProc may be 0, in which case the name of the entry point
        !          4628: ** defaults to "sqlite3_extension_init".
        !          4629: ** ^The sqlite3_load_extension() interface returns
        !          4630: ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
        !          4631: ** ^If an error occurs and pzErrMsg is not 0, then the
        !          4632: ** [sqlite3_load_extension()] interface shall attempt to
        !          4633: ** fill *pzErrMsg with error message text stored in memory
        !          4634: ** obtained from [sqlite3_malloc()]. The calling function
        !          4635: ** should free this memory by calling [sqlite3_free()].
        !          4636: **
        !          4637: ** ^Extension loading must be enabled using
        !          4638: ** [sqlite3_enable_load_extension()] prior to calling this API,
        !          4639: ** otherwise an error will be returned.
        !          4640: **
        !          4641: ** See also the [load_extension() SQL function].
        !          4642: */
        !          4643: SQLITE_API int sqlite3_load_extension(
        !          4644:   sqlite3 *db,          /* Load the extension into this database connection */
        !          4645:   const char *zFile,    /* Name of the shared library containing extension */
        !          4646:   const char *zProc,    /* Entry point.  Derived from zFile if 0 */
        !          4647:   char **pzErrMsg       /* Put error message here if not 0 */
        !          4648: );
        !          4649: 
        !          4650: /*
        !          4651: ** CAPI3REF: Enable Or Disable Extension Loading
        !          4652: **
        !          4653: ** ^So as not to open security holes in older applications that are
        !          4654: ** unprepared to deal with extension loading, and as a means of disabling
        !          4655: ** extension loading while evaluating user-entered SQL, the following API
        !          4656: ** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
        !          4657: **
        !          4658: ** ^Extension loading is off by default. See ticket #1863.
        !          4659: ** ^Call the sqlite3_enable_load_extension() routine with onoff==1
        !          4660: ** to turn extension loading on and call it with onoff==0 to turn
        !          4661: ** it back off again.
        !          4662: */
        !          4663: SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
        !          4664: 
        !          4665: /*
        !          4666: ** CAPI3REF: Automatically Load Statically Linked Extensions
        !          4667: **
        !          4668: ** ^This interface causes the xEntryPoint() function to be invoked for
        !          4669: ** each new [database connection] that is created.  The idea here is that
        !          4670: ** xEntryPoint() is the entry point for a statically linked SQLite extension
        !          4671: ** that is to be automatically loaded into all new database connections.
        !          4672: **
        !          4673: ** ^(Even though the function prototype shows that xEntryPoint() takes
        !          4674: ** no arguments and returns void, SQLite invokes xEntryPoint() with three
        !          4675: ** arguments and expects and integer result as if the signature of the
        !          4676: ** entry point where as follows:
        !          4677: **
        !          4678: ** <blockquote><pre>
        !          4679: ** &nbsp;  int xEntryPoint(
        !          4680: ** &nbsp;    sqlite3 *db,
        !          4681: ** &nbsp;    const char **pzErrMsg,
        !          4682: ** &nbsp;    const struct sqlite3_api_routines *pThunk
        !          4683: ** &nbsp;  );
        !          4684: ** </pre></blockquote>)^
        !          4685: **
        !          4686: ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg
        !          4687: ** point to an appropriate error message (obtained from [sqlite3_mprintf()])
        !          4688: ** and return an appropriate [error code].  ^SQLite ensures that *pzErrMsg
        !          4689: ** is NULL before calling the xEntryPoint().  ^SQLite will invoke
        !          4690: ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns.  ^If any
        !          4691: ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()],
        !          4692: ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail.
        !          4693: **
        !          4694: ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already
        !          4695: ** on the list of automatic extensions is a harmless no-op. ^No entry point
        !          4696: ** will be called more than once for each database connection that is opened.
        !          4697: **
        !          4698: ** See also: [sqlite3_reset_auto_extension()].
        !          4699: */
        !          4700: SQLITE_API int sqlite3_auto_extension(void (*xEntryPoint)(void));
        !          4701: 
        !          4702: /*
        !          4703: ** CAPI3REF: Reset Automatic Extension Loading
        !          4704: **
        !          4705: ** ^This interface disables all automatic extensions previously
        !          4706: ** registered using [sqlite3_auto_extension()].
        !          4707: */
        !          4708: SQLITE_API void sqlite3_reset_auto_extension(void);
        !          4709: 
        !          4710: /*
        !          4711: ** The interface to the virtual-table mechanism is currently considered
        !          4712: ** to be experimental.  The interface might change in incompatible ways.
        !          4713: ** If this is a problem for you, do not use the interface at this time.
        !          4714: **
        !          4715: ** When the virtual-table mechanism stabilizes, we will declare the
        !          4716: ** interface fixed, support it indefinitely, and remove this comment.
        !          4717: */
        !          4718: 
        !          4719: /*
        !          4720: ** Structures used by the virtual table interface
        !          4721: */
        !          4722: typedef struct sqlite3_vtab sqlite3_vtab;
        !          4723: typedef struct sqlite3_index_info sqlite3_index_info;
        !          4724: typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
        !          4725: typedef struct sqlite3_module sqlite3_module;
        !          4726: 
        !          4727: /*
        !          4728: ** CAPI3REF: Virtual Table Object
        !          4729: ** KEYWORDS: sqlite3_module {virtual table module}
        !          4730: **
        !          4731: ** This structure, sometimes called a "virtual table module", 
        !          4732: ** defines the implementation of a [virtual tables].  
        !          4733: ** This structure consists mostly of methods for the module.
        !          4734: **
        !          4735: ** ^A virtual table module is created by filling in a persistent
        !          4736: ** instance of this structure and passing a pointer to that instance
        !          4737: ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
        !          4738: ** ^The registration remains valid until it is replaced by a different
        !          4739: ** module or until the [database connection] closes.  The content
        !          4740: ** of this structure must not change while it is registered with
        !          4741: ** any database connection.
        !          4742: */
        !          4743: struct sqlite3_module {
        !          4744:   int iVersion;
        !          4745:   int (*xCreate)(sqlite3*, void *pAux,
        !          4746:                int argc, const char *const*argv,
        !          4747:                sqlite3_vtab **ppVTab, char**);
        !          4748:   int (*xConnect)(sqlite3*, void *pAux,
        !          4749:                int argc, const char *const*argv,
        !          4750:                sqlite3_vtab **ppVTab, char**);
        !          4751:   int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
        !          4752:   int (*xDisconnect)(sqlite3_vtab *pVTab);
        !          4753:   int (*xDestroy)(sqlite3_vtab *pVTab);
        !          4754:   int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
        !          4755:   int (*xClose)(sqlite3_vtab_cursor*);
        !          4756:   int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
        !          4757:                 int argc, sqlite3_value **argv);
        !          4758:   int (*xNext)(sqlite3_vtab_cursor*);
        !          4759:   int (*xEof)(sqlite3_vtab_cursor*);
        !          4760:   int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
        !          4761:   int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
        !          4762:   int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
        !          4763:   int (*xBegin)(sqlite3_vtab *pVTab);
        !          4764:   int (*xSync)(sqlite3_vtab *pVTab);
        !          4765:   int (*xCommit)(sqlite3_vtab *pVTab);
        !          4766:   int (*xRollback)(sqlite3_vtab *pVTab);
        !          4767:   int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
        !          4768:                        void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
        !          4769:                        void **ppArg);
        !          4770:   int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
        !          4771:   /* The methods above are in version 1 of the sqlite_module object. Those 
        !          4772:   ** below are for version 2 and greater. */
        !          4773:   int (*xSavepoint)(sqlite3_vtab *pVTab, int);
        !          4774:   int (*xRelease)(sqlite3_vtab *pVTab, int);
        !          4775:   int (*xRollbackTo)(sqlite3_vtab *pVTab, int);
        !          4776: };
        !          4777: 
        !          4778: /*
        !          4779: ** CAPI3REF: Virtual Table Indexing Information
        !          4780: ** KEYWORDS: sqlite3_index_info
        !          4781: **
        !          4782: ** The sqlite3_index_info structure and its substructures is used as part
        !          4783: ** of the [virtual table] interface to
        !          4784: ** pass information into and receive the reply from the [xBestIndex]
        !          4785: ** method of a [virtual table module].  The fields under **Inputs** are the
        !          4786: ** inputs to xBestIndex and are read-only.  xBestIndex inserts its
        !          4787: ** results into the **Outputs** fields.
        !          4788: **
        !          4789: ** ^(The aConstraint[] array records WHERE clause constraints of the form:
        !          4790: **
        !          4791: ** <blockquote>column OP expr</blockquote>
        !          4792: **
        !          4793: ** where OP is =, &lt;, &lt;=, &gt;, or &gt;=.)^  ^(The particular operator is
        !          4794: ** stored in aConstraint[].op using one of the
        !          4795: ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^
        !          4796: ** ^(The index of the column is stored in
        !          4797: ** aConstraint[].iColumn.)^  ^(aConstraint[].usable is TRUE if the
        !          4798: ** expr on the right-hand side can be evaluated (and thus the constraint
        !          4799: ** is usable) and false if it cannot.)^
        !          4800: **
        !          4801: ** ^The optimizer automatically inverts terms of the form "expr OP column"
        !          4802: ** and makes other simplifications to the WHERE clause in an attempt to
        !          4803: ** get as many WHERE clause terms into the form shown above as possible.
        !          4804: ** ^The aConstraint[] array only reports WHERE clause terms that are
        !          4805: ** relevant to the particular virtual table being queried.
        !          4806: **
        !          4807: ** ^Information about the ORDER BY clause is stored in aOrderBy[].
        !          4808: ** ^Each term of aOrderBy records a column of the ORDER BY clause.
        !          4809: **
        !          4810: ** The [xBestIndex] method must fill aConstraintUsage[] with information
        !          4811: ** about what parameters to pass to xFilter.  ^If argvIndex>0 then
        !          4812: ** the right-hand side of the corresponding aConstraint[] is evaluated
        !          4813: ** and becomes the argvIndex-th entry in argv.  ^(If aConstraintUsage[].omit
        !          4814: ** is true, then the constraint is assumed to be fully handled by the
        !          4815: ** virtual table and is not checked again by SQLite.)^
        !          4816: **
        !          4817: ** ^The idxNum and idxPtr values are recorded and passed into the
        !          4818: ** [xFilter] method.
        !          4819: ** ^[sqlite3_free()] is used to free idxPtr if and only if
        !          4820: ** needToFreeIdxPtr is true.
        !          4821: **
        !          4822: ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in
        !          4823: ** the correct order to satisfy the ORDER BY clause so that no separate
        !          4824: ** sorting step is required.
        !          4825: **
        !          4826: ** ^The estimatedCost value is an estimate of the cost of doing the
        !          4827: ** particular lookup.  A full scan of a table with N entries should have
        !          4828: ** a cost of N.  A binary search of a table of N entries should have a
        !          4829: ** cost of approximately log(N).
        !          4830: */
        !          4831: struct sqlite3_index_info {
        !          4832:   /* Inputs */
        !          4833:   int nConstraint;           /* Number of entries in aConstraint */
        !          4834:   struct sqlite3_index_constraint {
        !          4835:      int iColumn;              /* Column on left-hand side of constraint */
        !          4836:      unsigned char op;         /* Constraint operator */
        !          4837:      unsigned char usable;     /* True if this constraint is usable */
        !          4838:      int iTermOffset;          /* Used internally - xBestIndex should ignore */
        !          4839:   } *aConstraint;            /* Table of WHERE clause constraints */
        !          4840:   int nOrderBy;              /* Number of terms in the ORDER BY clause */
        !          4841:   struct sqlite3_index_orderby {
        !          4842:      int iColumn;              /* Column number */
        !          4843:      unsigned char desc;       /* True for DESC.  False for ASC. */
        !          4844:   } *aOrderBy;               /* The ORDER BY clause */
        !          4845:   /* Outputs */
        !          4846:   struct sqlite3_index_constraint_usage {
        !          4847:     int argvIndex;           /* if >0, constraint is part of argv to xFilter */
        !          4848:     unsigned char omit;      /* Do not code a test for this constraint */
        !          4849:   } *aConstraintUsage;
        !          4850:   int idxNum;                /* Number used to identify the index */
        !          4851:   char *idxStr;              /* String, possibly obtained from sqlite3_malloc */
        !          4852:   int needToFreeIdxStr;      /* Free idxStr using sqlite3_free() if true */
        !          4853:   int orderByConsumed;       /* True if output is already ordered */
        !          4854:   double estimatedCost;      /* Estimated cost of using this index */
        !          4855: };
        !          4856: 
        !          4857: /*
        !          4858: ** CAPI3REF: Virtual Table Constraint Operator Codes
        !          4859: **
        !          4860: ** These macros defined the allowed values for the
        !          4861: ** [sqlite3_index_info].aConstraint[].op field.  Each value represents
        !          4862: ** an operator that is part of a constraint term in the wHERE clause of
        !          4863: ** a query that uses a [virtual table].
        !          4864: */
        !          4865: #define SQLITE_INDEX_CONSTRAINT_EQ    2
        !          4866: #define SQLITE_INDEX_CONSTRAINT_GT    4
        !          4867: #define SQLITE_INDEX_CONSTRAINT_LE    8
        !          4868: #define SQLITE_INDEX_CONSTRAINT_LT    16
        !          4869: #define SQLITE_INDEX_CONSTRAINT_GE    32
        !          4870: #define SQLITE_INDEX_CONSTRAINT_MATCH 64
        !          4871: 
        !          4872: /*
        !          4873: ** CAPI3REF: Register A Virtual Table Implementation
        !          4874: **
        !          4875: ** ^These routines are used to register a new [virtual table module] name.
        !          4876: ** ^Module names must be registered before
        !          4877: ** creating a new [virtual table] using the module and before using a
        !          4878: ** preexisting [virtual table] for the module.
        !          4879: **
        !          4880: ** ^The module name is registered on the [database connection] specified
        !          4881: ** by the first parameter.  ^The name of the module is given by the 
        !          4882: ** second parameter.  ^The third parameter is a pointer to
        !          4883: ** the implementation of the [virtual table module].   ^The fourth
        !          4884: ** parameter is an arbitrary client data pointer that is passed through
        !          4885: ** into the [xCreate] and [xConnect] methods of the virtual table module
        !          4886: ** when a new virtual table is be being created or reinitialized.
        !          4887: **
        !          4888: ** ^The sqlite3_create_module_v2() interface has a fifth parameter which
        !          4889: ** is a pointer to a destructor for the pClientData.  ^SQLite will
        !          4890: ** invoke the destructor function (if it is not NULL) when SQLite
        !          4891: ** no longer needs the pClientData pointer.  ^The destructor will also
        !          4892: ** be invoked if the call to sqlite3_create_module_v2() fails.
        !          4893: ** ^The sqlite3_create_module()
        !          4894: ** interface is equivalent to sqlite3_create_module_v2() with a NULL
        !          4895: ** destructor.
        !          4896: */
        !          4897: SQLITE_API int sqlite3_create_module(
        !          4898:   sqlite3 *db,               /* SQLite connection to register module with */
        !          4899:   const char *zName,         /* Name of the module */
        !          4900:   const sqlite3_module *p,   /* Methods for the module */
        !          4901:   void *pClientData          /* Client data for xCreate/xConnect */
        !          4902: );
        !          4903: SQLITE_API int sqlite3_create_module_v2(
        !          4904:   sqlite3 *db,               /* SQLite connection to register module with */
        !          4905:   const char *zName,         /* Name of the module */
        !          4906:   const sqlite3_module *p,   /* Methods for the module */
        !          4907:   void *pClientData,         /* Client data for xCreate/xConnect */
        !          4908:   void(*xDestroy)(void*)     /* Module destructor function */
        !          4909: );
        !          4910: 
        !          4911: /*
        !          4912: ** CAPI3REF: Virtual Table Instance Object
        !          4913: ** KEYWORDS: sqlite3_vtab
        !          4914: **
        !          4915: ** Every [virtual table module] implementation uses a subclass
        !          4916: ** of this object to describe a particular instance
        !          4917: ** of the [virtual table].  Each subclass will
        !          4918: ** be tailored to the specific needs of the module implementation.
        !          4919: ** The purpose of this superclass is to define certain fields that are
        !          4920: ** common to all module implementations.
        !          4921: **
        !          4922: ** ^Virtual tables methods can set an error message by assigning a
        !          4923: ** string obtained from [sqlite3_mprintf()] to zErrMsg.  The method should
        !          4924: ** take care that any prior string is freed by a call to [sqlite3_free()]
        !          4925: ** prior to assigning a new string to zErrMsg.  ^After the error message
        !          4926: ** is delivered up to the client application, the string will be automatically
        !          4927: ** freed by sqlite3_free() and the zErrMsg field will be zeroed.
        !          4928: */
        !          4929: struct sqlite3_vtab {
        !          4930:   const sqlite3_module *pModule;  /* The module for this virtual table */
        !          4931:   int nRef;                       /* NO LONGER USED */
        !          4932:   char *zErrMsg;                  /* Error message from sqlite3_mprintf() */
        !          4933:   /* Virtual table implementations will typically add additional fields */
        !          4934: };
        !          4935: 
        !          4936: /*
        !          4937: ** CAPI3REF: Virtual Table Cursor Object
        !          4938: ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
        !          4939: **
        !          4940: ** Every [virtual table module] implementation uses a subclass of the
        !          4941: ** following structure to describe cursors that point into the
        !          4942: ** [virtual table] and are used
        !          4943: ** to loop through the virtual table.  Cursors are created using the
        !          4944: ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
        !          4945: ** by the [sqlite3_module.xClose | xClose] method.  Cursors are used
        !          4946: ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
        !          4947: ** of the module.  Each module implementation will define
        !          4948: ** the content of a cursor structure to suit its own needs.
        !          4949: **
        !          4950: ** This superclass exists in order to define fields of the cursor that
        !          4951: ** are common to all implementations.
        !          4952: */
        !          4953: struct sqlite3_vtab_cursor {
        !          4954:   sqlite3_vtab *pVtab;      /* Virtual table of this cursor */
        !          4955:   /* Virtual table implementations will typically add additional fields */
        !          4956: };
        !          4957: 
        !          4958: /*
        !          4959: ** CAPI3REF: Declare The Schema Of A Virtual Table
        !          4960: **
        !          4961: ** ^The [xCreate] and [xConnect] methods of a
        !          4962: ** [virtual table module] call this interface
        !          4963: ** to declare the format (the names and datatypes of the columns) of
        !          4964: ** the virtual tables they implement.
        !          4965: */
        !          4966: SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL);
        !          4967: 
        !          4968: /*
        !          4969: ** CAPI3REF: Overload A Function For A Virtual Table
        !          4970: **
        !          4971: ** ^(Virtual tables can provide alternative implementations of functions
        !          4972: ** using the [xFindFunction] method of the [virtual table module].  
        !          4973: ** But global versions of those functions
        !          4974: ** must exist in order to be overloaded.)^
        !          4975: **
        !          4976: ** ^(This API makes sure a global version of a function with a particular
        !          4977: ** name and number of parameters exists.  If no such function exists
        !          4978: ** before this API is called, a new function is created.)^  ^The implementation
        !          4979: ** of the new function always causes an exception to be thrown.  So
        !          4980: ** the new function is not good for anything by itself.  Its only
        !          4981: ** purpose is to be a placeholder function that can be overloaded
        !          4982: ** by a [virtual table].
        !          4983: */
        !          4984: SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
        !          4985: 
        !          4986: /*
        !          4987: ** The interface to the virtual-table mechanism defined above (back up
        !          4988: ** to a comment remarkably similar to this one) is currently considered
        !          4989: ** to be experimental.  The interface might change in incompatible ways.
        !          4990: ** If this is a problem for you, do not use the interface at this time.
        !          4991: **
        !          4992: ** When the virtual-table mechanism stabilizes, we will declare the
        !          4993: ** interface fixed, support it indefinitely, and remove this comment.
        !          4994: */
        !          4995: 
        !          4996: /*
        !          4997: ** CAPI3REF: A Handle To An Open BLOB
        !          4998: ** KEYWORDS: {BLOB handle} {BLOB handles}
        !          4999: **
        !          5000: ** An instance of this object represents an open BLOB on which
        !          5001: ** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
        !          5002: ** ^Objects of this type are created by [sqlite3_blob_open()]
        !          5003: ** and destroyed by [sqlite3_blob_close()].
        !          5004: ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
        !          5005: ** can be used to read or write small subsections of the BLOB.
        !          5006: ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
        !          5007: */
        !          5008: typedef struct sqlite3_blob sqlite3_blob;
        !          5009: 
        !          5010: /*
        !          5011: ** CAPI3REF: Open A BLOB For Incremental I/O
        !          5012: **
        !          5013: ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
        !          5014: ** in row iRow, column zColumn, table zTable in database zDb;
        !          5015: ** in other words, the same BLOB that would be selected by:
        !          5016: **
        !          5017: ** <pre>
        !          5018: **     SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
        !          5019: ** </pre>)^
        !          5020: **
        !          5021: ** ^If the flags parameter is non-zero, then the BLOB is opened for read
        !          5022: ** and write access. ^If it is zero, the BLOB is opened for read access.
        !          5023: ** ^It is not possible to open a column that is part of an index or primary 
        !          5024: ** key for writing. ^If [foreign key constraints] are enabled, it is 
        !          5025: ** not possible to open a column that is part of a [child key] for writing.
        !          5026: **
        !          5027: ** ^Note that the database name is not the filename that contains
        !          5028: ** the database but rather the symbolic name of the database that
        !          5029: ** appears after the AS keyword when the database is connected using [ATTACH].
        !          5030: ** ^For the main database file, the database name is "main".
        !          5031: ** ^For TEMP tables, the database name is "temp".
        !          5032: **
        !          5033: ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is written
        !          5034: ** to *ppBlob. Otherwise an [error code] is returned and *ppBlob is set
        !          5035: ** to be a null pointer.)^
        !          5036: ** ^This function sets the [database connection] error code and message
        !          5037: ** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()] and related
        !          5038: ** functions. ^Note that the *ppBlob variable is always initialized in a
        !          5039: ** way that makes it safe to invoke [sqlite3_blob_close()] on *ppBlob
        !          5040: ** regardless of the success or failure of this routine.
        !          5041: **
        !          5042: ** ^(If the row that a BLOB handle points to is modified by an
        !          5043: ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
        !          5044: ** then the BLOB handle is marked as "expired".
        !          5045: ** This is true if any column of the row is changed, even a column
        !          5046: ** other than the one the BLOB handle is open on.)^
        !          5047: ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
        !          5048: ** an expired BLOB handle fail with a return code of [SQLITE_ABORT].
        !          5049: ** ^(Changes written into a BLOB prior to the BLOB expiring are not
        !          5050: ** rolled back by the expiration of the BLOB.  Such changes will eventually
        !          5051: ** commit if the transaction continues to completion.)^
        !          5052: **
        !          5053: ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
        !          5054: ** the opened blob.  ^The size of a blob may not be changed by this
        !          5055: ** interface.  Use the [UPDATE] SQL command to change the size of a
        !          5056: ** blob.
        !          5057: **
        !          5058: ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
        !          5059: ** and the built-in [zeroblob] SQL function can be used, if desired,
        !          5060: ** to create an empty, zero-filled blob in which to read or write using
        !          5061: ** this interface.
        !          5062: **
        !          5063: ** To avoid a resource leak, every open [BLOB handle] should eventually
        !          5064: ** be released by a call to [sqlite3_blob_close()].
        !          5065: */
        !          5066: SQLITE_API int sqlite3_blob_open(
        !          5067:   sqlite3*,
        !          5068:   const char *zDb,
        !          5069:   const char *zTable,
        !          5070:   const char *zColumn,
        !          5071:   sqlite3_int64 iRow,
        !          5072:   int flags,
        !          5073:   sqlite3_blob **ppBlob
        !          5074: );
        !          5075: 
        !          5076: /*
        !          5077: ** CAPI3REF: Move a BLOB Handle to a New Row
        !          5078: **
        !          5079: ** ^This function is used to move an existing blob handle so that it points
        !          5080: ** to a different row of the same database table. ^The new row is identified
        !          5081: ** by the rowid value passed as the second argument. Only the row can be
        !          5082: ** changed. ^The database, table and column on which the blob handle is open
        !          5083: ** remain the same. Moving an existing blob handle to a new row can be
        !          5084: ** faster than closing the existing handle and opening a new one.
        !          5085: **
        !          5086: ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -
        !          5087: ** it must exist and there must be either a blob or text value stored in
        !          5088: ** the nominated column.)^ ^If the new row is not present in the table, or if
        !          5089: ** it does not contain a blob or text value, or if another error occurs, an
        !          5090: ** SQLite error code is returned and the blob handle is considered aborted.
        !          5091: ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or
        !          5092: ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return
        !          5093: ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle
        !          5094: ** always returns zero.
        !          5095: **
        !          5096: ** ^This function sets the database handle error code and message.
        !          5097: */
        !          5098: SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);
        !          5099: 
        !          5100: /*
        !          5101: ** CAPI3REF: Close A BLOB Handle
        !          5102: **
        !          5103: ** ^Closes an open [BLOB handle].
        !          5104: **
        !          5105: ** ^Closing a BLOB shall cause the current transaction to commit
        !          5106: ** if there are no other BLOBs, no pending prepared statements, and the
        !          5107: ** database connection is in [autocommit mode].
        !          5108: ** ^If any writes were made to the BLOB, they might be held in cache
        !          5109: ** until the close operation if they will fit.
        !          5110: **
        !          5111: ** ^(Closing the BLOB often forces the changes
        !          5112: ** out to disk and so if any I/O errors occur, they will likely occur
        !          5113: ** at the time when the BLOB is closed.  Any errors that occur during
        !          5114: ** closing are reported as a non-zero return value.)^
        !          5115: **
        !          5116: ** ^(The BLOB is closed unconditionally.  Even if this routine returns
        !          5117: ** an error code, the BLOB is still closed.)^
        !          5118: **
        !          5119: ** ^Calling this routine with a null pointer (such as would be returned
        !          5120: ** by a failed call to [sqlite3_blob_open()]) is a harmless no-op.
        !          5121: */
        !          5122: SQLITE_API int sqlite3_blob_close(sqlite3_blob *);
        !          5123: 
        !          5124: /*
        !          5125: ** CAPI3REF: Return The Size Of An Open BLOB
        !          5126: **
        !          5127: ** ^Returns the size in bytes of the BLOB accessible via the 
        !          5128: ** successfully opened [BLOB handle] in its only argument.  ^The
        !          5129: ** incremental blob I/O routines can only read or overwriting existing
        !          5130: ** blob content; they cannot change the size of a blob.
        !          5131: **
        !          5132: ** This routine only works on a [BLOB handle] which has been created
        !          5133: ** by a prior successful call to [sqlite3_blob_open()] and which has not
        !          5134: ** been closed by [sqlite3_blob_close()].  Passing any other pointer in
        !          5135: ** to this routine results in undefined and probably undesirable behavior.
        !          5136: */
        !          5137: SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *);
        !          5138: 
        !          5139: /*
        !          5140: ** CAPI3REF: Read Data From A BLOB Incrementally
        !          5141: **
        !          5142: ** ^(This function is used to read data from an open [BLOB handle] into a
        !          5143: ** caller-supplied buffer. N bytes of data are copied into buffer Z
        !          5144: ** from the open BLOB, starting at offset iOffset.)^
        !          5145: **
        !          5146: ** ^If offset iOffset is less than N bytes from the end of the BLOB,
        !          5147: ** [SQLITE_ERROR] is returned and no data is read.  ^If N or iOffset is
        !          5148: ** less than zero, [SQLITE_ERROR] is returned and no data is read.
        !          5149: ** ^The size of the blob (and hence the maximum value of N+iOffset)
        !          5150: ** can be determined using the [sqlite3_blob_bytes()] interface.
        !          5151: **
        !          5152: ** ^An attempt to read from an expired [BLOB handle] fails with an
        !          5153: ** error code of [SQLITE_ABORT].
        !          5154: **
        !          5155: ** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
        !          5156: ** Otherwise, an [error code] or an [extended error code] is returned.)^
        !          5157: **
        !          5158: ** This routine only works on a [BLOB handle] which has been created
        !          5159: ** by a prior successful call to [sqlite3_blob_open()] and which has not
        !          5160: ** been closed by [sqlite3_blob_close()].  Passing any other pointer in
        !          5161: ** to this routine results in undefined and probably undesirable behavior.
        !          5162: **
        !          5163: ** See also: [sqlite3_blob_write()].
        !          5164: */
        !          5165: SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
        !          5166: 
        !          5167: /*
        !          5168: ** CAPI3REF: Write Data Into A BLOB Incrementally
        !          5169: **
        !          5170: ** ^This function is used to write data into an open [BLOB handle] from a
        !          5171: ** caller-supplied buffer. ^N bytes of data are copied from the buffer Z
        !          5172: ** into the open BLOB, starting at offset iOffset.
        !          5173: **
        !          5174: ** ^If the [BLOB handle] passed as the first argument was not opened for
        !          5175: ** writing (the flags parameter to [sqlite3_blob_open()] was zero),
        !          5176: ** this function returns [SQLITE_READONLY].
        !          5177: **
        !          5178: ** ^This function may only modify the contents of the BLOB; it is
        !          5179: ** not possible to increase the size of a BLOB using this API.
        !          5180: ** ^If offset iOffset is less than N bytes from the end of the BLOB,
        !          5181: ** [SQLITE_ERROR] is returned and no data is written.  ^If N is
        !          5182: ** less than zero [SQLITE_ERROR] is returned and no data is written.
        !          5183: ** The size of the BLOB (and hence the maximum value of N+iOffset)
        !          5184: ** can be determined using the [sqlite3_blob_bytes()] interface.
        !          5185: **
        !          5186: ** ^An attempt to write to an expired [BLOB handle] fails with an
        !          5187: ** error code of [SQLITE_ABORT].  ^Writes to the BLOB that occurred
        !          5188: ** before the [BLOB handle] expired are not rolled back by the
        !          5189: ** expiration of the handle, though of course those changes might
        !          5190: ** have been overwritten by the statement that expired the BLOB handle
        !          5191: ** or by other independent statements.
        !          5192: **
        !          5193: ** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
        !          5194: ** Otherwise, an  [error code] or an [extended error code] is returned.)^
        !          5195: **
        !          5196: ** This routine only works on a [BLOB handle] which has been created
        !          5197: ** by a prior successful call to [sqlite3_blob_open()] and which has not
        !          5198: ** been closed by [sqlite3_blob_close()].  Passing any other pointer in
        !          5199: ** to this routine results in undefined and probably undesirable behavior.
        !          5200: **
        !          5201: ** See also: [sqlite3_blob_read()].
        !          5202: */
        !          5203: SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
        !          5204: 
        !          5205: /*
        !          5206: ** CAPI3REF: Virtual File System Objects
        !          5207: **
        !          5208: ** A virtual filesystem (VFS) is an [sqlite3_vfs] object
        !          5209: ** that SQLite uses to interact
        !          5210: ** with the underlying operating system.  Most SQLite builds come with a
        !          5211: ** single default VFS that is appropriate for the host computer.
        !          5212: ** New VFSes can be registered and existing VFSes can be unregistered.
        !          5213: ** The following interfaces are provided.
        !          5214: **
        !          5215: ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
        !          5216: ** ^Names are case sensitive.
        !          5217: ** ^Names are zero-terminated UTF-8 strings.
        !          5218: ** ^If there is no match, a NULL pointer is returned.
        !          5219: ** ^If zVfsName is NULL then the default VFS is returned.
        !          5220: **
        !          5221: ** ^New VFSes are registered with sqlite3_vfs_register().
        !          5222: ** ^Each new VFS becomes the default VFS if the makeDflt flag is set.
        !          5223: ** ^The same VFS can be registered multiple times without injury.
        !          5224: ** ^To make an existing VFS into the default VFS, register it again
        !          5225: ** with the makeDflt flag set.  If two different VFSes with the
        !          5226: ** same name are registered, the behavior is undefined.  If a
        !          5227: ** VFS is registered with a name that is NULL or an empty string,
        !          5228: ** then the behavior is undefined.
        !          5229: **
        !          5230: ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.
        !          5231: ** ^(If the default VFS is unregistered, another VFS is chosen as
        !          5232: ** the default.  The choice for the new VFS is arbitrary.)^
        !          5233: */
        !          5234: SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
        !          5235: SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
        !          5236: SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);
        !          5237: 
        !          5238: /*
        !          5239: ** CAPI3REF: Mutexes
        !          5240: **
        !          5241: ** The SQLite core uses these routines for thread
        !          5242: ** synchronization. Though they are intended for internal
        !          5243: ** use by SQLite, code that links against SQLite is
        !          5244: ** permitted to use any of these routines.
        !          5245: **
        !          5246: ** The SQLite source code contains multiple implementations
        !          5247: ** of these mutex routines.  An appropriate implementation
        !          5248: ** is selected automatically at compile-time.  ^(The following
        !          5249: ** implementations are available in the SQLite core:
        !          5250: **
        !          5251: ** <ul>
        !          5252: ** <li>   SQLITE_MUTEX_OS2
        !          5253: ** <li>   SQLITE_MUTEX_PTHREAD
        !          5254: ** <li>   SQLITE_MUTEX_W32
        !          5255: ** <li>   SQLITE_MUTEX_NOOP
        !          5256: ** </ul>)^
        !          5257: **
        !          5258: ** ^The SQLITE_MUTEX_NOOP implementation is a set of routines
        !          5259: ** that does no real locking and is appropriate for use in
        !          5260: ** a single-threaded application.  ^The SQLITE_MUTEX_OS2,
        !          5261: ** SQLITE_MUTEX_PTHREAD, and SQLITE_MUTEX_W32 implementations
        !          5262: ** are appropriate for use on OS/2, Unix, and Windows.
        !          5263: **
        !          5264: ** ^(If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
        !          5265: ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
        !          5266: ** implementation is included with the library. In this case the
        !          5267: ** application must supply a custom mutex implementation using the
        !          5268: ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
        !          5269: ** before calling sqlite3_initialize() or any other public sqlite3_
        !          5270: ** function that calls sqlite3_initialize().)^
        !          5271: **
        !          5272: ** ^The sqlite3_mutex_alloc() routine allocates a new
        !          5273: ** mutex and returns a pointer to it. ^If it returns NULL
        !          5274: ** that means that a mutex could not be allocated.  ^SQLite
        !          5275: ** will unwind its stack and return an error.  ^(The argument
        !          5276: ** to sqlite3_mutex_alloc() is one of these integer constants:
        !          5277: **
        !          5278: ** <ul>
        !          5279: ** <li>  SQLITE_MUTEX_FAST
        !          5280: ** <li>  SQLITE_MUTEX_RECURSIVE
        !          5281: ** <li>  SQLITE_MUTEX_STATIC_MASTER
        !          5282: ** <li>  SQLITE_MUTEX_STATIC_MEM
        !          5283: ** <li>  SQLITE_MUTEX_STATIC_MEM2
        !          5284: ** <li>  SQLITE_MUTEX_STATIC_PRNG
        !          5285: ** <li>  SQLITE_MUTEX_STATIC_LRU
        !          5286: ** <li>  SQLITE_MUTEX_STATIC_LRU2
        !          5287: ** </ul>)^
        !          5288: **
        !          5289: ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
        !          5290: ** cause sqlite3_mutex_alloc() to create
        !          5291: ** a new mutex.  ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
        !          5292: ** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
        !          5293: ** The mutex implementation does not need to make a distinction
        !          5294: ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
        !          5295: ** not want to.  ^SQLite will only request a recursive mutex in
        !          5296: ** cases where it really needs one.  ^If a faster non-recursive mutex
        !          5297: ** implementation is available on the host platform, the mutex subsystem
        !          5298: ** might return such a mutex in response to SQLITE_MUTEX_FAST.
        !          5299: **
        !          5300: ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
        !          5301: ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
        !          5302: ** a pointer to a static preexisting mutex.  ^Six static mutexes are
        !          5303: ** used by the current version of SQLite.  Future versions of SQLite
        !          5304: ** may add additional static mutexes.  Static mutexes are for internal
        !          5305: ** use by SQLite only.  Applications that use SQLite mutexes should
        !          5306: ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
        !          5307: ** SQLITE_MUTEX_RECURSIVE.
        !          5308: **
        !          5309: ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
        !          5310: ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
        !          5311: ** returns a different mutex on every call.  ^But for the static
        !          5312: ** mutex types, the same mutex is returned on every call that has
        !          5313: ** the same type number.
        !          5314: **
        !          5315: ** ^The sqlite3_mutex_free() routine deallocates a previously
        !          5316: ** allocated dynamic mutex.  ^SQLite is careful to deallocate every
        !          5317: ** dynamic mutex that it allocates.  The dynamic mutexes must not be in
        !          5318: ** use when they are deallocated.  Attempting to deallocate a static
        !          5319: ** mutex results in undefined behavior.  ^SQLite never deallocates
        !          5320: ** a static mutex.
        !          5321: **
        !          5322: ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
        !          5323: ** to enter a mutex.  ^If another thread is already within the mutex,
        !          5324: ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
        !          5325: ** SQLITE_BUSY.  ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
        !          5326: ** upon successful entry.  ^(Mutexes created using
        !          5327: ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
        !          5328: ** In such cases the,
        !          5329: ** mutex must be exited an equal number of times before another thread
        !          5330: ** can enter.)^  ^(If the same thread tries to enter any other
        !          5331: ** kind of mutex more than once, the behavior is undefined.
        !          5332: ** SQLite will never exhibit
        !          5333: ** such behavior in its own use of mutexes.)^
        !          5334: **
        !          5335: ** ^(Some systems (for example, Windows 95) do not support the operation
        !          5336: ** implemented by sqlite3_mutex_try().  On those systems, sqlite3_mutex_try()
        !          5337: ** will always return SQLITE_BUSY.  The SQLite core only ever uses
        !          5338: ** sqlite3_mutex_try() as an optimization so this is acceptable behavior.)^
        !          5339: **
        !          5340: ** ^The sqlite3_mutex_leave() routine exits a mutex that was
        !          5341: ** previously entered by the same thread.   ^(The behavior
        !          5342: ** is undefined if the mutex is not currently entered by the
        !          5343: ** calling thread or is not currently allocated.  SQLite will
        !          5344: ** never do either.)^
        !          5345: **
        !          5346: ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or
        !          5347: ** sqlite3_mutex_leave() is a NULL pointer, then all three routines
        !          5348: ** behave as no-ops.
        !          5349: **
        !          5350: ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
        !          5351: */
        !          5352: SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int);
        !          5353: SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*);
        !          5354: SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*);
        !          5355: SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*);
        !          5356: SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*);
        !          5357: 
        !          5358: /*
        !          5359: ** CAPI3REF: Mutex Methods Object
        !          5360: **
        !          5361: ** An instance of this structure defines the low-level routines
        !          5362: ** used to allocate and use mutexes.
        !          5363: **
        !          5364: ** Usually, the default mutex implementations provided by SQLite are
        !          5365: ** sufficient, however the user has the option of substituting a custom
        !          5366: ** implementation for specialized deployments or systems for which SQLite
        !          5367: ** does not provide a suitable implementation. In this case, the user
        !          5368: ** creates and populates an instance of this structure to pass
        !          5369: ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
        !          5370: ** Additionally, an instance of this structure can be used as an
        !          5371: ** output variable when querying the system for the current mutex
        !          5372: ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
        !          5373: **
        !          5374: ** ^The xMutexInit method defined by this structure is invoked as
        !          5375: ** part of system initialization by the sqlite3_initialize() function.
        !          5376: ** ^The xMutexInit routine is called by SQLite exactly once for each
        !          5377: ** effective call to [sqlite3_initialize()].
        !          5378: **
        !          5379: ** ^The xMutexEnd method defined by this structure is invoked as
        !          5380: ** part of system shutdown by the sqlite3_shutdown() function. The
        !          5381: ** implementation of this method is expected to release all outstanding
        !          5382: ** resources obtained by the mutex methods implementation, especially
        !          5383: ** those obtained by the xMutexInit method.  ^The xMutexEnd()
        !          5384: ** interface is invoked exactly once for each call to [sqlite3_shutdown()].
        !          5385: **
        !          5386: ** ^(The remaining seven methods defined by this structure (xMutexAlloc,
        !          5387: ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
        !          5388: ** xMutexNotheld) implement the following interfaces (respectively):
        !          5389: **
        !          5390: ** <ul>
        !          5391: **   <li>  [sqlite3_mutex_alloc()] </li>
        !          5392: **   <li>  [sqlite3_mutex_free()] </li>
        !          5393: **   <li>  [sqlite3_mutex_enter()] </li>
        !          5394: **   <li>  [sqlite3_mutex_try()] </li>
        !          5395: **   <li>  [sqlite3_mutex_leave()] </li>
        !          5396: **   <li>  [sqlite3_mutex_held()] </li>
        !          5397: **   <li>  [sqlite3_mutex_notheld()] </li>
        !          5398: ** </ul>)^
        !          5399: **
        !          5400: ** The only difference is that the public sqlite3_XXX functions enumerated
        !          5401: ** above silently ignore any invocations that pass a NULL pointer instead
        !          5402: ** of a valid mutex handle. The implementations of the methods defined
        !          5403: ** by this structure are not required to handle this case, the results
        !          5404: ** of passing a NULL pointer instead of a valid mutex handle are undefined
        !          5405: ** (i.e. it is acceptable to provide an implementation that segfaults if
        !          5406: ** it is passed a NULL pointer).
        !          5407: **
        !          5408: ** The xMutexInit() method must be threadsafe.  ^It must be harmless to
        !          5409: ** invoke xMutexInit() multiple times within the same process and without
        !          5410: ** intervening calls to xMutexEnd().  Second and subsequent calls to
        !          5411: ** xMutexInit() must be no-ops.
        !          5412: **
        !          5413: ** ^xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
        !          5414: ** and its associates).  ^Similarly, xMutexAlloc() must not use SQLite memory
        !          5415: ** allocation for a static mutex.  ^However xMutexAlloc() may use SQLite
        !          5416: ** memory allocation for a fast or recursive mutex.
        !          5417: **
        !          5418: ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
        !          5419: ** called, but only if the prior call to xMutexInit returned SQLITE_OK.
        !          5420: ** If xMutexInit fails in any way, it is expected to clean up after itself
        !          5421: ** prior to returning.
        !          5422: */
        !          5423: typedef struct sqlite3_mutex_methods sqlite3_mutex_methods;
        !          5424: struct sqlite3_mutex_methods {
        !          5425:   int (*xMutexInit)(void);
        !          5426:   int (*xMutexEnd)(void);
        !          5427:   sqlite3_mutex *(*xMutexAlloc)(int);
        !          5428:   void (*xMutexFree)(sqlite3_mutex *);
        !          5429:   void (*xMutexEnter)(sqlite3_mutex *);
        !          5430:   int (*xMutexTry)(sqlite3_mutex *);
        !          5431:   void (*xMutexLeave)(sqlite3_mutex *);
        !          5432:   int (*xMutexHeld)(sqlite3_mutex *);
        !          5433:   int (*xMutexNotheld)(sqlite3_mutex *);
        !          5434: };
        !          5435: 
        !          5436: /*
        !          5437: ** CAPI3REF: Mutex Verification Routines
        !          5438: **
        !          5439: ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
        !          5440: ** are intended for use inside assert() statements.  ^The SQLite core
        !          5441: ** never uses these routines except inside an assert() and applications
        !          5442: ** are advised to follow the lead of the core.  ^The SQLite core only
        !          5443: ** provides implementations for these routines when it is compiled
        !          5444: ** with the SQLITE_DEBUG flag.  ^External mutex implementations
        !          5445: ** are only required to provide these routines if SQLITE_DEBUG is
        !          5446: ** defined and if NDEBUG is not defined.
        !          5447: **
        !          5448: ** ^These routines should return true if the mutex in their argument
        !          5449: ** is held or not held, respectively, by the calling thread.
        !          5450: **
        !          5451: ** ^The implementation is not required to provided versions of these
        !          5452: ** routines that actually work. If the implementation does not provide working
        !          5453: ** versions of these routines, it should at least provide stubs that always
        !          5454: ** return true so that one does not get spurious assertion failures.
        !          5455: **
        !          5456: ** ^If the argument to sqlite3_mutex_held() is a NULL pointer then
        !          5457: ** the routine should return 1.   This seems counter-intuitive since
        !          5458: ** clearly the mutex cannot be held if it does not exist.  But
        !          5459: ** the reason the mutex does not exist is because the build is not
        !          5460: ** using mutexes.  And we do not want the assert() containing the
        !          5461: ** call to sqlite3_mutex_held() to fail, so a non-zero return is
        !          5462: ** the appropriate thing to do.  ^The sqlite3_mutex_notheld()
        !          5463: ** interface should also return 1 when given a NULL pointer.
        !          5464: */
        !          5465: #ifndef NDEBUG
        !          5466: SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*);
        !          5467: SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*);
        !          5468: #endif
        !          5469: 
        !          5470: /*
        !          5471: ** CAPI3REF: Mutex Types
        !          5472: **
        !          5473: ** The [sqlite3_mutex_alloc()] interface takes a single argument
        !          5474: ** which is one of these integer constants.
        !          5475: **
        !          5476: ** The set of static mutexes may change from one SQLite release to the
        !          5477: ** next.  Applications that override the built-in mutex logic must be
        !          5478: ** prepared to accommodate additional static mutexes.
        !          5479: */
        !          5480: #define SQLITE_MUTEX_FAST             0
        !          5481: #define SQLITE_MUTEX_RECURSIVE        1
        !          5482: #define SQLITE_MUTEX_STATIC_MASTER    2
        !          5483: #define SQLITE_MUTEX_STATIC_MEM       3  /* sqlite3_malloc() */
        !          5484: #define SQLITE_MUTEX_STATIC_MEM2      4  /* NOT USED */
        !          5485: #define SQLITE_MUTEX_STATIC_OPEN      4  /* sqlite3BtreeOpen() */
        !          5486: #define SQLITE_MUTEX_STATIC_PRNG      5  /* sqlite3_random() */
        !          5487: #define SQLITE_MUTEX_STATIC_LRU       6  /* lru page list */
        !          5488: #define SQLITE_MUTEX_STATIC_LRU2      7  /* NOT USED */
        !          5489: #define SQLITE_MUTEX_STATIC_PMEM      7  /* sqlite3PageMalloc() */
        !          5490: 
        !          5491: /*
        !          5492: ** CAPI3REF: Retrieve the mutex for a database connection
        !          5493: **
        !          5494: ** ^This interface returns a pointer the [sqlite3_mutex] object that 
        !          5495: ** serializes access to the [database connection] given in the argument
        !          5496: ** when the [threading mode] is Serialized.
        !          5497: ** ^If the [threading mode] is Single-thread or Multi-thread then this
        !          5498: ** routine returns a NULL pointer.
        !          5499: */
        !          5500: SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*);
        !          5501: 
        !          5502: /*
        !          5503: ** CAPI3REF: Low-Level Control Of Database Files
        !          5504: **
        !          5505: ** ^The [sqlite3_file_control()] interface makes a direct call to the
        !          5506: ** xFileControl method for the [sqlite3_io_methods] object associated
        !          5507: ** with a particular database identified by the second argument. ^The
        !          5508: ** name of the database is "main" for the main database or "temp" for the
        !          5509: ** TEMP database, or the name that appears after the AS keyword for
        !          5510: ** databases that are added using the [ATTACH] SQL command.
        !          5511: ** ^A NULL pointer can be used in place of "main" to refer to the
        !          5512: ** main database file.
        !          5513: ** ^The third and fourth parameters to this routine
        !          5514: ** are passed directly through to the second and third parameters of
        !          5515: ** the xFileControl method.  ^The return value of the xFileControl
        !          5516: ** method becomes the return value of this routine.
        !          5517: **
        !          5518: ** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes
        !          5519: ** a pointer to the underlying [sqlite3_file] object to be written into
        !          5520: ** the space pointed to by the 4th parameter.  ^The SQLITE_FCNTL_FILE_POINTER
        !          5521: ** case is a short-circuit path which does not actually invoke the
        !          5522: ** underlying sqlite3_io_methods.xFileControl method.
        !          5523: **
        !          5524: ** ^If the second parameter (zDbName) does not match the name of any
        !          5525: ** open database file, then SQLITE_ERROR is returned.  ^This error
        !          5526: ** code is not remembered and will not be recalled by [sqlite3_errcode()]
        !          5527: ** or [sqlite3_errmsg()].  The underlying xFileControl method might
        !          5528: ** also return SQLITE_ERROR.  There is no way to distinguish between
        !          5529: ** an incorrect zDbName and an SQLITE_ERROR return from the underlying
        !          5530: ** xFileControl method.
        !          5531: **
        !          5532: ** See also: [SQLITE_FCNTL_LOCKSTATE]
        !          5533: */
        !          5534: SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);
        !          5535: 
        !          5536: /*
        !          5537: ** CAPI3REF: Testing Interface
        !          5538: **
        !          5539: ** ^The sqlite3_test_control() interface is used to read out internal
        !          5540: ** state of SQLite and to inject faults into SQLite for testing
        !          5541: ** purposes.  ^The first parameter is an operation code that determines
        !          5542: ** the number, meaning, and operation of all subsequent parameters.
        !          5543: **
        !          5544: ** This interface is not for use by applications.  It exists solely
        !          5545: ** for verifying the correct operation of the SQLite library.  Depending
        !          5546: ** on how the SQLite library is compiled, this interface might not exist.
        !          5547: **
        !          5548: ** The details of the operation codes, their meanings, the parameters
        !          5549: ** they take, and what they do are all subject to change without notice.
        !          5550: ** Unlike most of the SQLite API, this function is not guaranteed to
        !          5551: ** operate consistently from one release to the next.
        !          5552: */
        !          5553: SQLITE_API int sqlite3_test_control(int op, ...);
        !          5554: 
        !          5555: /*
        !          5556: ** CAPI3REF: Testing Interface Operation Codes
        !          5557: **
        !          5558: ** These constants are the valid operation code parameters used
        !          5559: ** as the first argument to [sqlite3_test_control()].
        !          5560: **
        !          5561: ** These parameters and their meanings are subject to change
        !          5562: ** without notice.  These values are for testing purposes only.
        !          5563: ** Applications should not use any of these parameters or the
        !          5564: ** [sqlite3_test_control()] interface.
        !          5565: */
        !          5566: #define SQLITE_TESTCTRL_FIRST                    5
        !          5567: #define SQLITE_TESTCTRL_PRNG_SAVE                5
        !          5568: #define SQLITE_TESTCTRL_PRNG_RESTORE             6
        !          5569: #define SQLITE_TESTCTRL_PRNG_RESET               7
        !          5570: #define SQLITE_TESTCTRL_BITVEC_TEST              8
        !          5571: #define SQLITE_TESTCTRL_FAULT_INSTALL            9
        !          5572: #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS     10
        !          5573: #define SQLITE_TESTCTRL_PENDING_BYTE            11
        !          5574: #define SQLITE_TESTCTRL_ASSERT                  12
        !          5575: #define SQLITE_TESTCTRL_ALWAYS                  13
        !          5576: #define SQLITE_TESTCTRL_RESERVE                 14
        !          5577: #define SQLITE_TESTCTRL_OPTIMIZATIONS           15
        !          5578: #define SQLITE_TESTCTRL_ISKEYWORD               16
        !          5579: #define SQLITE_TESTCTRL_PGHDRSZ                 17
        !          5580: #define SQLITE_TESTCTRL_SCRATCHMALLOC           18
        !          5581: #define SQLITE_TESTCTRL_LOCALTIME_FAULT         19
        !          5582: #define SQLITE_TESTCTRL_LAST                    19
        !          5583: 
        !          5584: /*
        !          5585: ** CAPI3REF: SQLite Runtime Status
        !          5586: **
        !          5587: ** ^This interface is used to retrieve runtime status information
        !          5588: ** about the performance of SQLite, and optionally to reset various
        !          5589: ** highwater marks.  ^The first argument is an integer code for
        !          5590: ** the specific parameter to measure.  ^(Recognized integer codes
        !          5591: ** are of the form [status parameters | SQLITE_STATUS_...].)^
        !          5592: ** ^The current value of the parameter is returned into *pCurrent.
        !          5593: ** ^The highest recorded value is returned in *pHighwater.  ^If the
        !          5594: ** resetFlag is true, then the highest record value is reset after
        !          5595: ** *pHighwater is written.  ^(Some parameters do not record the highest
        !          5596: ** value.  For those parameters
        !          5597: ** nothing is written into *pHighwater and the resetFlag is ignored.)^
        !          5598: ** ^(Other parameters record only the highwater mark and not the current
        !          5599: ** value.  For these latter parameters nothing is written into *pCurrent.)^
        !          5600: **
        !          5601: ** ^The sqlite3_status() routine returns SQLITE_OK on success and a
        !          5602: ** non-zero [error code] on failure.
        !          5603: **
        !          5604: ** This routine is threadsafe but is not atomic.  This routine can be
        !          5605: ** called while other threads are running the same or different SQLite
        !          5606: ** interfaces.  However the values returned in *pCurrent and
        !          5607: ** *pHighwater reflect the status of SQLite at different points in time
        !          5608: ** and it is possible that another thread might change the parameter
        !          5609: ** in between the times when *pCurrent and *pHighwater are written.
        !          5610: **
        !          5611: ** See also: [sqlite3_db_status()]
        !          5612: */
        !          5613: SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);
        !          5614: 
        !          5615: 
        !          5616: /*
        !          5617: ** CAPI3REF: Status Parameters
        !          5618: ** KEYWORDS: {status parameters}
        !          5619: **
        !          5620: ** These integer constants designate various run-time status parameters
        !          5621: ** that can be returned by [sqlite3_status()].
        !          5622: **
        !          5623: ** <dl>
        !          5624: ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt>
        !          5625: ** <dd>This parameter is the current amount of memory checked out
        !          5626: ** using [sqlite3_malloc()], either directly or indirectly.  The
        !          5627: ** figure includes calls made to [sqlite3_malloc()] by the application
        !          5628: ** and internal memory usage by the SQLite library.  Scratch memory
        !          5629: ** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache
        !          5630: ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
        !          5631: ** this parameter.  The amount returned is the sum of the allocation
        !          5632: ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^
        !          5633: **
        !          5634: ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt>
        !          5635: ** <dd>This parameter records the largest memory allocation request
        !          5636: ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
        !          5637: ** internal equivalents).  Only the value returned in the
        !          5638: ** *pHighwater parameter to [sqlite3_status()] is of interest.  
        !          5639: ** The value written into the *pCurrent parameter is undefined.</dd>)^
        !          5640: **
        !          5641: ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt>
        !          5642: ** <dd>This parameter records the number of separate memory allocations
        !          5643: ** currently checked out.</dd>)^
        !          5644: **
        !          5645: ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt>
        !          5646: ** <dd>This parameter returns the number of pages used out of the
        !          5647: ** [pagecache memory allocator] that was configured using 
        !          5648: ** [SQLITE_CONFIG_PAGECACHE].  The
        !          5649: ** value returned is in pages, not in bytes.</dd>)^
        !          5650: **
        !          5651: ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 
        !          5652: ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>
        !          5653: ** <dd>This parameter returns the number of bytes of page cache
        !          5654: ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE]
        !          5655: ** buffer and where forced to overflow to [sqlite3_malloc()].  The
        !          5656: ** returned value includes allocations that overflowed because they
        !          5657: ** where too large (they were larger than the "sz" parameter to
        !          5658: ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
        !          5659: ** no space was left in the page cache.</dd>)^
        !          5660: **
        !          5661: ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>
        !          5662: ** <dd>This parameter records the largest memory allocation request
        !          5663: ** handed to [pagecache memory allocator].  Only the value returned in the
        !          5664: ** *pHighwater parameter to [sqlite3_status()] is of interest.  
        !          5665: ** The value written into the *pCurrent parameter is undefined.</dd>)^
        !          5666: **
        !          5667: ** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt>
        !          5668: ** <dd>This parameter returns the number of allocations used out of the
        !          5669: ** [scratch memory allocator] configured using
        !          5670: ** [SQLITE_CONFIG_SCRATCH].  The value returned is in allocations, not
        !          5671: ** in bytes.  Since a single thread may only have one scratch allocation
        !          5672: ** outstanding at time, this parameter also reports the number of threads
        !          5673: ** using scratch memory at the same time.</dd>)^
        !          5674: **
        !          5675: ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>
        !          5676: ** <dd>This parameter returns the number of bytes of scratch memory
        !          5677: ** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH]
        !          5678: ** buffer and where forced to overflow to [sqlite3_malloc()].  The values
        !          5679: ** returned include overflows because the requested allocation was too
        !          5680: ** larger (that is, because the requested allocation was larger than the
        !          5681: ** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer
        !          5682: ** slots were available.
        !          5683: ** </dd>)^
        !          5684: **
        !          5685: ** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt>
        !          5686: ** <dd>This parameter records the largest memory allocation request
        !          5687: ** handed to [scratch memory allocator].  Only the value returned in the
        !          5688: ** *pHighwater parameter to [sqlite3_status()] is of interest.  
        !          5689: ** The value written into the *pCurrent parameter is undefined.</dd>)^
        !          5690: **
        !          5691: ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt>
        !          5692: ** <dd>This parameter records the deepest parser stack.  It is only
        !          5693: ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
        !          5694: ** </dl>
        !          5695: **
        !          5696: ** New status parameters may be added from time to time.
        !          5697: */
        !          5698: #define SQLITE_STATUS_MEMORY_USED          0
        !          5699: #define SQLITE_STATUS_PAGECACHE_USED       1
        !          5700: #define SQLITE_STATUS_PAGECACHE_OVERFLOW   2
        !          5701: #define SQLITE_STATUS_SCRATCH_USED         3
        !          5702: #define SQLITE_STATUS_SCRATCH_OVERFLOW     4
        !          5703: #define SQLITE_STATUS_MALLOC_SIZE          5
        !          5704: #define SQLITE_STATUS_PARSER_STACK         6
        !          5705: #define SQLITE_STATUS_PAGECACHE_SIZE       7
        !          5706: #define SQLITE_STATUS_SCRATCH_SIZE         8
        !          5707: #define SQLITE_STATUS_MALLOC_COUNT         9
        !          5708: 
        !          5709: /*
        !          5710: ** CAPI3REF: Database Connection Status
        !          5711: **
        !          5712: ** ^This interface is used to retrieve runtime status information 
        !          5713: ** about a single [database connection].  ^The first argument is the
        !          5714: ** database connection object to be interrogated.  ^The second argument
        !          5715: ** is an integer constant, taken from the set of
        !          5716: ** [SQLITE_DBSTATUS options], that
        !          5717: ** determines the parameter to interrogate.  The set of 
        !          5718: ** [SQLITE_DBSTATUS options] is likely
        !          5719: ** to grow in future releases of SQLite.
        !          5720: **
        !          5721: ** ^The current value of the requested parameter is written into *pCur
        !          5722: ** and the highest instantaneous value is written into *pHiwtr.  ^If
        !          5723: ** the resetFlg is true, then the highest instantaneous value is
        !          5724: ** reset back down to the current value.
        !          5725: **
        !          5726: ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a
        !          5727: ** non-zero [error code] on failure.
        !          5728: **
        !          5729: ** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
        !          5730: */
        !          5731: SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
        !          5732: 
        !          5733: /*
        !          5734: ** CAPI3REF: Status Parameters for database connections
        !          5735: ** KEYWORDS: {SQLITE_DBSTATUS options}
        !          5736: **
        !          5737: ** These constants are the available integer "verbs" that can be passed as
        !          5738: ** the second argument to the [sqlite3_db_status()] interface.
        !          5739: **
        !          5740: ** New verbs may be added in future releases of SQLite. Existing verbs
        !          5741: ** might be discontinued. Applications should check the return code from
        !          5742: ** [sqlite3_db_status()] to make sure that the call worked.
        !          5743: ** The [sqlite3_db_status()] interface will return a non-zero error code
        !          5744: ** if a discontinued or unsupported verb is invoked.
        !          5745: **
        !          5746: ** <dl>
        !          5747: ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
        !          5748: ** <dd>This parameter returns the number of lookaside memory slots currently
        !          5749: ** checked out.</dd>)^
        !          5750: **
        !          5751: ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt>
        !          5752: ** <dd>This parameter returns the number malloc attempts that were 
        !          5753: ** satisfied using lookaside memory. Only the high-water value is meaningful;
        !          5754: ** the current value is always zero.)^
        !          5755: **
        !          5756: ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]]
        !          5757: ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt>
        !          5758: ** <dd>This parameter returns the number malloc attempts that might have
        !          5759: ** been satisfied using lookaside memory but failed due to the amount of
        !          5760: ** memory requested being larger than the lookaside slot size.
        !          5761: ** Only the high-water value is meaningful;
        !          5762: ** the current value is always zero.)^
        !          5763: **
        !          5764: ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]]
        !          5765: ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt>
        !          5766: ** <dd>This parameter returns the number malloc attempts that might have
        !          5767: ** been satisfied using lookaside memory but failed due to all lookaside
        !          5768: ** memory already being in use.
        !          5769: ** Only the high-water value is meaningful;
        !          5770: ** the current value is always zero.)^
        !          5771: **
        !          5772: ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt>
        !          5773: ** <dd>This parameter returns the approximate number of of bytes of heap
        !          5774: ** memory used by all pager caches associated with the database connection.)^
        !          5775: ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
        !          5776: **
        !          5777: ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt>
        !          5778: ** <dd>This parameter returns the approximate number of of bytes of heap
        !          5779: ** memory used to store the schema for all databases associated
        !          5780: ** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 
        !          5781: ** ^The full amount of memory used by the schemas is reported, even if the
        !          5782: ** schema memory is shared with other database connections due to
        !          5783: ** [shared cache mode] being enabled.
        !          5784: ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.
        !          5785: **
        !          5786: ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt>
        !          5787: ** <dd>This parameter returns the approximate number of of bytes of heap
        !          5788: ** and lookaside memory used by all prepared statements associated with
        !          5789: ** the database connection.)^
        !          5790: ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
        !          5791: ** </dd>
        !          5792: ** </dl>
        !          5793: */
        !          5794: #define SQLITE_DBSTATUS_LOOKASIDE_USED       0
        !          5795: #define SQLITE_DBSTATUS_CACHE_USED           1
        !          5796: #define SQLITE_DBSTATUS_SCHEMA_USED          2
        !          5797: #define SQLITE_DBSTATUS_STMT_USED            3
        !          5798: #define SQLITE_DBSTATUS_LOOKASIDE_HIT        4
        !          5799: #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE  5
        !          5800: #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL  6
        !          5801: #define SQLITE_DBSTATUS_MAX                  6   /* Largest defined DBSTATUS */
        !          5802: 
        !          5803: 
        !          5804: /*
        !          5805: ** CAPI3REF: Prepared Statement Status
        !          5806: **
        !          5807: ** ^(Each prepared statement maintains various
        !          5808: ** [SQLITE_STMTSTATUS counters] that measure the number
        !          5809: ** of times it has performed specific operations.)^  These counters can
        !          5810: ** be used to monitor the performance characteristics of the prepared
        !          5811: ** statements.  For example, if the number of table steps greatly exceeds
        !          5812: ** the number of table searches or result rows, that would tend to indicate
        !          5813: ** that the prepared statement is using a full table scan rather than
        !          5814: ** an index.  
        !          5815: **
        !          5816: ** ^(This interface is used to retrieve and reset counter values from
        !          5817: ** a [prepared statement].  The first argument is the prepared statement
        !          5818: ** object to be interrogated.  The second argument
        !          5819: ** is an integer code for a specific [SQLITE_STMTSTATUS counter]
        !          5820: ** to be interrogated.)^
        !          5821: ** ^The current value of the requested counter is returned.
        !          5822: ** ^If the resetFlg is true, then the counter is reset to zero after this
        !          5823: ** interface call returns.
        !          5824: **
        !          5825: ** See also: [sqlite3_status()] and [sqlite3_db_status()].
        !          5826: */
        !          5827: SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
        !          5828: 
        !          5829: /*
        !          5830: ** CAPI3REF: Status Parameters for prepared statements
        !          5831: ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters}
        !          5832: **
        !          5833: ** These preprocessor macros define integer codes that name counter
        !          5834: ** values associated with the [sqlite3_stmt_status()] interface.
        !          5835: ** The meanings of the various counters are as follows:
        !          5836: **
        !          5837: ** <dl>
        !          5838: ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt>
        !          5839: ** <dd>^This is the number of times that SQLite has stepped forward in
        !          5840: ** a table as part of a full table scan.  Large numbers for this counter
        !          5841: ** may indicate opportunities for performance improvement through 
        !          5842: ** careful use of indices.</dd>
        !          5843: **
        !          5844: ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt>
        !          5845: ** <dd>^This is the number of sort operations that have occurred.
        !          5846: ** A non-zero value in this counter may indicate an opportunity to
        !          5847: ** improvement performance through careful use of indices.</dd>
        !          5848: **
        !          5849: ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt>
        !          5850: ** <dd>^This is the number of rows inserted into transient indices that
        !          5851: ** were created automatically in order to help joins run faster.
        !          5852: ** A non-zero value in this counter may indicate an opportunity to
        !          5853: ** improvement performance by adding permanent indices that do not
        !          5854: ** need to be reinitialized each time the statement is run.</dd>
        !          5855: **
        !          5856: ** </dl>
        !          5857: */
        !          5858: #define SQLITE_STMTSTATUS_FULLSCAN_STEP     1
        !          5859: #define SQLITE_STMTSTATUS_SORT              2
        !          5860: #define SQLITE_STMTSTATUS_AUTOINDEX         3
        !          5861: 
        !          5862: /*
        !          5863: ** CAPI3REF: Custom Page Cache Object
        !          5864: **
        !          5865: ** The sqlite3_pcache type is opaque.  It is implemented by
        !          5866: ** the pluggable module.  The SQLite core has no knowledge of
        !          5867: ** its size or internal structure and never deals with the
        !          5868: ** sqlite3_pcache object except by holding and passing pointers
        !          5869: ** to the object.
        !          5870: **
        !          5871: ** See [sqlite3_pcache_methods] for additional information.
        !          5872: */
        !          5873: typedef struct sqlite3_pcache sqlite3_pcache;
        !          5874: 
        !          5875: /*
        !          5876: ** CAPI3REF: Application Defined Page Cache.
        !          5877: ** KEYWORDS: {page cache}
        !          5878: **
        !          5879: ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE], ...) interface can
        !          5880: ** register an alternative page cache implementation by passing in an 
        !          5881: ** instance of the sqlite3_pcache_methods structure.)^
        !          5882: ** In many applications, most of the heap memory allocated by 
        !          5883: ** SQLite is used for the page cache.
        !          5884: ** By implementing a 
        !          5885: ** custom page cache using this API, an application can better control
        !          5886: ** the amount of memory consumed by SQLite, the way in which 
        !          5887: ** that memory is allocated and released, and the policies used to 
        !          5888: ** determine exactly which parts of a database file are cached and for 
        !          5889: ** how long.
        !          5890: **
        !          5891: ** The alternative page cache mechanism is an
        !          5892: ** extreme measure that is only needed by the most demanding applications.
        !          5893: ** The built-in page cache is recommended for most uses.
        !          5894: **
        !          5895: ** ^(The contents of the sqlite3_pcache_methods structure are copied to an
        !          5896: ** internal buffer by SQLite within the call to [sqlite3_config].  Hence
        !          5897: ** the application may discard the parameter after the call to
        !          5898: ** [sqlite3_config()] returns.)^
        !          5899: **
        !          5900: ** [[the xInit() page cache method]]
        !          5901: ** ^(The xInit() method is called once for each effective 
        !          5902: ** call to [sqlite3_initialize()])^
        !          5903: ** (usually only once during the lifetime of the process). ^(The xInit()
        !          5904: ** method is passed a copy of the sqlite3_pcache_methods.pArg value.)^
        !          5905: ** The intent of the xInit() method is to set up global data structures 
        !          5906: ** required by the custom page cache implementation. 
        !          5907: ** ^(If the xInit() method is NULL, then the 
        !          5908: ** built-in default page cache is used instead of the application defined
        !          5909: ** page cache.)^
        !          5910: **
        !          5911: ** [[the xShutdown() page cache method]]
        !          5912: ** ^The xShutdown() method is called by [sqlite3_shutdown()].
        !          5913: ** It can be used to clean up 
        !          5914: ** any outstanding resources before process shutdown, if required.
        !          5915: ** ^The xShutdown() method may be NULL.
        !          5916: **
        !          5917: ** ^SQLite automatically serializes calls to the xInit method,
        !          5918: ** so the xInit method need not be threadsafe.  ^The
        !          5919: ** xShutdown method is only called from [sqlite3_shutdown()] so it does
        !          5920: ** not need to be threadsafe either.  All other methods must be threadsafe
        !          5921: ** in multithreaded applications.
        !          5922: **
        !          5923: ** ^SQLite will never invoke xInit() more than once without an intervening
        !          5924: ** call to xShutdown().
        !          5925: **
        !          5926: ** [[the xCreate() page cache methods]]
        !          5927: ** ^SQLite invokes the xCreate() method to construct a new cache instance.
        !          5928: ** SQLite will typically create one cache instance for each open database file,
        !          5929: ** though this is not guaranteed. ^The
        !          5930: ** first parameter, szPage, is the size in bytes of the pages that must
        !          5931: ** be allocated by the cache.  ^szPage will not be a power of two.  ^szPage
        !          5932: ** will the page size of the database file that is to be cached plus an
        !          5933: ** increment (here called "R") of less than 250.  SQLite will use the
        !          5934: ** extra R bytes on each page to store metadata about the underlying
        !          5935: ** database page on disk.  The value of R depends
        !          5936: ** on the SQLite version, the target platform, and how SQLite was compiled.
        !          5937: ** ^(R is constant for a particular build of SQLite. Except, there are two
        !          5938: ** distinct values of R when SQLite is compiled with the proprietary
        !          5939: ** ZIPVFS extension.)^  ^The second argument to
        !          5940: ** xCreate(), bPurgeable, is true if the cache being created will
        !          5941: ** be used to cache database pages of a file stored on disk, or
        !          5942: ** false if it is used for an in-memory database. The cache implementation
        !          5943: ** does not have to do anything special based with the value of bPurgeable;
        !          5944: ** it is purely advisory.  ^On a cache where bPurgeable is false, SQLite will
        !          5945: ** never invoke xUnpin() except to deliberately delete a page.
        !          5946: ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to
        !          5947: ** false will always have the "discard" flag set to true.  
        !          5948: ** ^Hence, a cache created with bPurgeable false will
        !          5949: ** never contain any unpinned pages.
        !          5950: **
        !          5951: ** [[the xCachesize() page cache method]]
        !          5952: ** ^(The xCachesize() method may be called at any time by SQLite to set the
        !          5953: ** suggested maximum cache-size (number of pages stored by) the cache
        !          5954: ** instance passed as the first argument. This is the value configured using
        !          5955: ** the SQLite "[PRAGMA cache_size]" command.)^  As with the bPurgeable
        !          5956: ** parameter, the implementation is not required to do anything with this
        !          5957: ** value; it is advisory only.
        !          5958: **
        !          5959: ** [[the xPagecount() page cache methods]]
        !          5960: ** The xPagecount() method must return the number of pages currently
        !          5961: ** stored in the cache, both pinned and unpinned.
        !          5962: ** 
        !          5963: ** [[the xFetch() page cache methods]]
        !          5964: ** The xFetch() method locates a page in the cache and returns a pointer to 
        !          5965: ** the page, or a NULL pointer.
        !          5966: ** A "page", in this context, means a buffer of szPage bytes aligned at an
        !          5967: ** 8-byte boundary. The page to be fetched is determined by the key. ^The
        !          5968: ** minimum key value is 1.  After it has been retrieved using xFetch, the page 
        !          5969: ** is considered to be "pinned".
        !          5970: **
        !          5971: ** If the requested page is already in the page cache, then the page cache
        !          5972: ** implementation must return a pointer to the page buffer with its content
        !          5973: ** intact.  If the requested page is not already in the cache, then the
        !          5974: ** cache implementation should use the value of the createFlag
        !          5975: ** parameter to help it determined what action to take:
        !          5976: **
        !          5977: ** <table border=1 width=85% align=center>
        !          5978: ** <tr><th> createFlag <th> Behaviour when page is not already in cache
        !          5979: ** <tr><td> 0 <td> Do not allocate a new page.  Return NULL.
        !          5980: ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so.
        !          5981: **                 Otherwise return NULL.
        !          5982: ** <tr><td> 2 <td> Make every effort to allocate a new page.  Only return
        !          5983: **                 NULL if allocating a new page is effectively impossible.
        !          5984: ** </table>
        !          5985: **
        !          5986: ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1.  SQLite
        !          5987: ** will only use a createFlag of 2 after a prior call with a createFlag of 1
        !          5988: ** failed.)^  In between the to xFetch() calls, SQLite may
        !          5989: ** attempt to unpin one or more cache pages by spilling the content of
        !          5990: ** pinned pages to disk and synching the operating system disk cache.
        !          5991: **
        !          5992: ** [[the xUnpin() page cache method]]
        !          5993: ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page
        !          5994: ** as its second argument.  If the third parameter, discard, is non-zero,
        !          5995: ** then the page must be evicted from the cache.
        !          5996: ** ^If the discard parameter is
        !          5997: ** zero, then the page may be discarded or retained at the discretion of
        !          5998: ** page cache implementation. ^The page cache implementation
        !          5999: ** may choose to evict unpinned pages at any time.
        !          6000: **
        !          6001: ** The cache must not perform any reference counting. A single 
        !          6002: ** call to xUnpin() unpins the page regardless of the number of prior calls 
        !          6003: ** to xFetch().
        !          6004: **
        !          6005: ** [[the xRekey() page cache methods]]
        !          6006: ** The xRekey() method is used to change the key value associated with the
        !          6007: ** page passed as the second argument. If the cache
        !          6008: ** previously contains an entry associated with newKey, it must be
        !          6009: ** discarded. ^Any prior cache entry associated with newKey is guaranteed not
        !          6010: ** to be pinned.
        !          6011: **
        !          6012: ** When SQLite calls the xTruncate() method, the cache must discard all
        !          6013: ** existing cache entries with page numbers (keys) greater than or equal
        !          6014: ** to the value of the iLimit parameter passed to xTruncate(). If any
        !          6015: ** of these pages are pinned, they are implicitly unpinned, meaning that
        !          6016: ** they can be safely discarded.
        !          6017: **
        !          6018: ** [[the xDestroy() page cache method]]
        !          6019: ** ^The xDestroy() method is used to delete a cache allocated by xCreate().
        !          6020: ** All resources associated with the specified cache should be freed. ^After
        !          6021: ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
        !          6022: ** handle invalid, and will not use it with any other sqlite3_pcache_methods
        !          6023: ** functions.
        !          6024: */
        !          6025: typedef struct sqlite3_pcache_methods sqlite3_pcache_methods;
        !          6026: struct sqlite3_pcache_methods {
        !          6027:   void *pArg;
        !          6028:   int (*xInit)(void*);
        !          6029:   void (*xShutdown)(void*);
        !          6030:   sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable);
        !          6031:   void (*xCachesize)(sqlite3_pcache*, int nCachesize);
        !          6032:   int (*xPagecount)(sqlite3_pcache*);
        !          6033:   void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
        !          6034:   void (*xUnpin)(sqlite3_pcache*, void*, int discard);
        !          6035:   void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey);
        !          6036:   void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
        !          6037:   void (*xDestroy)(sqlite3_pcache*);
        !          6038: };
        !          6039: 
        !          6040: /*
        !          6041: ** CAPI3REF: Online Backup Object
        !          6042: **
        !          6043: ** The sqlite3_backup object records state information about an ongoing
        !          6044: ** online backup operation.  ^The sqlite3_backup object is created by
        !          6045: ** a call to [sqlite3_backup_init()] and is destroyed by a call to
        !          6046: ** [sqlite3_backup_finish()].
        !          6047: **
        !          6048: ** See Also: [Using the SQLite Online Backup API]
        !          6049: */
        !          6050: typedef struct sqlite3_backup sqlite3_backup;
        !          6051: 
        !          6052: /*
        !          6053: ** CAPI3REF: Online Backup API.
        !          6054: **
        !          6055: ** The backup API copies the content of one database into another.
        !          6056: ** It is useful either for creating backups of databases or
        !          6057: ** for copying in-memory databases to or from persistent files. 
        !          6058: **
        !          6059: ** See Also: [Using the SQLite Online Backup API]
        !          6060: **
        !          6061: ** ^SQLite holds a write transaction open on the destination database file
        !          6062: ** for the duration of the backup operation.
        !          6063: ** ^The source database is read-locked only while it is being read;
        !          6064: ** it is not locked continuously for the entire backup operation.
        !          6065: ** ^Thus, the backup may be performed on a live source database without
        !          6066: ** preventing other database connections from
        !          6067: ** reading or writing to the source database while the backup is underway.
        !          6068: ** 
        !          6069: ** ^(To perform a backup operation: 
        !          6070: **   <ol>
        !          6071: **     <li><b>sqlite3_backup_init()</b> is called once to initialize the
        !          6072: **         backup, 
        !          6073: **     <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 
        !          6074: **         the data between the two databases, and finally
        !          6075: **     <li><b>sqlite3_backup_finish()</b> is called to release all resources 
        !          6076: **         associated with the backup operation. 
        !          6077: **   </ol>)^
        !          6078: ** There should be exactly one call to sqlite3_backup_finish() for each
        !          6079: ** successful call to sqlite3_backup_init().
        !          6080: **
        !          6081: ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b>
        !          6082: **
        !          6083: ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 
        !          6084: ** [database connection] associated with the destination database 
        !          6085: ** and the database name, respectively.
        !          6086: ** ^The database name is "main" for the main database, "temp" for the
        !          6087: ** temporary database, or the name specified after the AS keyword in
        !          6088: ** an [ATTACH] statement for an attached database.
        !          6089: ** ^The S and M arguments passed to 
        !          6090: ** sqlite3_backup_init(D,N,S,M) identify the [database connection]
        !          6091: ** and database name of the source database, respectively.
        !          6092: ** ^The source and destination [database connections] (parameters S and D)
        !          6093: ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
        !          6094: ** an error.
        !          6095: **
        !          6096: ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
        !          6097: ** returned and an error code and error message are stored in the
        !          6098: ** destination [database connection] D.
        !          6099: ** ^The error code and message for the failed call to sqlite3_backup_init()
        !          6100: ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
        !          6101: ** [sqlite3_errmsg16()] functions.
        !          6102: ** ^A successful call to sqlite3_backup_init() returns a pointer to an
        !          6103: ** [sqlite3_backup] object.
        !          6104: ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and
        !          6105: ** sqlite3_backup_finish() functions to perform the specified backup 
        !          6106: ** operation.
        !          6107: **
        !          6108: ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b>
        !          6109: **
        !          6110: ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 
        !          6111: ** the source and destination databases specified by [sqlite3_backup] object B.
        !          6112: ** ^If N is negative, all remaining source pages are copied. 
        !          6113: ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there
        !          6114: ** are still more pages to be copied, then the function returns [SQLITE_OK].
        !          6115: ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages
        !          6116: ** from source to destination, then it returns [SQLITE_DONE].
        !          6117: ** ^If an error occurs while running sqlite3_backup_step(B,N),
        !          6118: ** then an [error code] is returned. ^As well as [SQLITE_OK] and
        !          6119: ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
        !          6120: ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an
        !          6121: ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
        !          6122: **
        !          6123: ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if
        !          6124: ** <ol>
        !          6125: ** <li> the destination database was opened read-only, or
        !          6126: ** <li> the destination database is using write-ahead-log journaling
        !          6127: ** and the destination and source page sizes differ, or
        !          6128: ** <li> the destination database is an in-memory database and the
        !          6129: ** destination and source page sizes differ.
        !          6130: ** </ol>)^
        !          6131: **
        !          6132: ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then
        !          6133: ** the [sqlite3_busy_handler | busy-handler function]
        !          6134: ** is invoked (if one is specified). ^If the 
        !          6135: ** busy-handler returns non-zero before the lock is available, then 
        !          6136: ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to
        !          6137: ** sqlite3_backup_step() can be retried later. ^If the source
        !          6138: ** [database connection]
        !          6139: ** is being used to write to the source database when sqlite3_backup_step()
        !          6140: ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this
        !          6141: ** case the call to sqlite3_backup_step() can be retried later on. ^(If
        !          6142: ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or
        !          6143: ** [SQLITE_READONLY] is returned, then 
        !          6144: ** there is no point in retrying the call to sqlite3_backup_step(). These 
        !          6145: ** errors are considered fatal.)^  The application must accept 
        !          6146: ** that the backup operation has failed and pass the backup operation handle 
        !          6147: ** to the sqlite3_backup_finish() to release associated resources.
        !          6148: **
        !          6149: ** ^The first call to sqlite3_backup_step() obtains an exclusive lock
        !          6150: ** on the destination file. ^The exclusive lock is not released until either 
        !          6151: ** sqlite3_backup_finish() is called or the backup operation is complete 
        !          6152: ** and sqlite3_backup_step() returns [SQLITE_DONE].  ^Every call to
        !          6153: ** sqlite3_backup_step() obtains a [shared lock] on the source database that
        !          6154: ** lasts for the duration of the sqlite3_backup_step() call.
        !          6155: ** ^Because the source database is not locked between calls to
        !          6156: ** sqlite3_backup_step(), the source database may be modified mid-way
        !          6157: ** through the backup process.  ^If the source database is modified by an
        !          6158: ** external process or via a database connection other than the one being
        !          6159: ** used by the backup operation, then the backup will be automatically
        !          6160: ** restarted by the next call to sqlite3_backup_step(). ^If the source 
        !          6161: ** database is modified by the using the same database connection as is used
        !          6162: ** by the backup operation, then the backup database is automatically
        !          6163: ** updated at the same time.
        !          6164: **
        !          6165: ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b>
        !          6166: **
        !          6167: ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 
        !          6168: ** application wishes to abandon the backup operation, the application
        !          6169: ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish().
        !          6170: ** ^The sqlite3_backup_finish() interfaces releases all
        !          6171: ** resources associated with the [sqlite3_backup] object. 
        !          6172: ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any
        !          6173: ** active write-transaction on the destination database is rolled back.
        !          6174: ** The [sqlite3_backup] object is invalid
        !          6175: ** and may not be used following a call to sqlite3_backup_finish().
        !          6176: **
        !          6177: ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no
        !          6178: ** sqlite3_backup_step() errors occurred, regardless or whether or not
        !          6179: ** sqlite3_backup_step() completed.
        !          6180: ** ^If an out-of-memory condition or IO error occurred during any prior
        !          6181: ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then
        !          6182: ** sqlite3_backup_finish() returns the corresponding [error code].
        !          6183: **
        !          6184: ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step()
        !          6185: ** is not a permanent error and does not affect the return value of
        !          6186: ** sqlite3_backup_finish().
        !          6187: **
        !          6188: ** [[sqlite3_backup__remaining()]] [[sqlite3_backup_pagecount()]]
        !          6189: ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b>
        !          6190: **
        !          6191: ** ^Each call to sqlite3_backup_step() sets two values inside
        !          6192: ** the [sqlite3_backup] object: the number of pages still to be backed
        !          6193: ** up and the total number of pages in the source database file.
        !          6194: ** The sqlite3_backup_remaining() and sqlite3_backup_pagecount() interfaces
        !          6195: ** retrieve these two values, respectively.
        !          6196: **
        !          6197: ** ^The values returned by these functions are only updated by
        !          6198: ** sqlite3_backup_step(). ^If the source database is modified during a backup
        !          6199: ** operation, then the values are not updated to account for any extra
        !          6200: ** pages that need to be updated or the size of the source database file
        !          6201: ** changing.
        !          6202: **
        !          6203: ** <b>Concurrent Usage of Database Handles</b>
        !          6204: **
        !          6205: ** ^The source [database connection] may be used by the application for other
        !          6206: ** purposes while a backup operation is underway or being initialized.
        !          6207: ** ^If SQLite is compiled and configured to support threadsafe database
        !          6208: ** connections, then the source database connection may be used concurrently
        !          6209: ** from within other threads.
        !          6210: **
        !          6211: ** However, the application must guarantee that the destination 
        !          6212: ** [database connection] is not passed to any other API (by any thread) after 
        !          6213: ** sqlite3_backup_init() is called and before the corresponding call to
        !          6214: ** sqlite3_backup_finish().  SQLite does not currently check to see
        !          6215: ** if the application incorrectly accesses the destination [database connection]
        !          6216: ** and so no error code is reported, but the operations may malfunction
        !          6217: ** nevertheless.  Use of the destination database connection while a
        !          6218: ** backup is in progress might also also cause a mutex deadlock.
        !          6219: **
        !          6220: ** If running in [shared cache mode], the application must
        !          6221: ** guarantee that the shared cache used by the destination database
        !          6222: ** is not accessed while the backup is running. In practice this means
        !          6223: ** that the application must guarantee that the disk file being 
        !          6224: ** backed up to is not accessed by any connection within the process,
        !          6225: ** not just the specific connection that was passed to sqlite3_backup_init().
        !          6226: **
        !          6227: ** The [sqlite3_backup] object itself is partially threadsafe. Multiple 
        !          6228: ** threads may safely make multiple concurrent calls to sqlite3_backup_step().
        !          6229: ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()
        !          6230: ** APIs are not strictly speaking threadsafe. If they are invoked at the
        !          6231: ** same time as another thread is invoking sqlite3_backup_step() it is
        !          6232: ** possible that they return invalid values.
        !          6233: */
        !          6234: SQLITE_API sqlite3_backup *sqlite3_backup_init(
        !          6235:   sqlite3 *pDest,                        /* Destination database handle */
        !          6236:   const char *zDestName,                 /* Destination database name */
        !          6237:   sqlite3 *pSource,                      /* Source database handle */
        !          6238:   const char *zSourceName                /* Source database name */
        !          6239: );
        !          6240: SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage);
        !          6241: SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p);
        !          6242: SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p);
        !          6243: SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p);
        !          6244: 
        !          6245: /*
        !          6246: ** CAPI3REF: Unlock Notification
        !          6247: **
        !          6248: ** ^When running in shared-cache mode, a database operation may fail with
        !          6249: ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
        !          6250: ** individual tables within the shared-cache cannot be obtained. See
        !          6251: ** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 
        !          6252: ** ^This API may be used to register a callback that SQLite will invoke 
        !          6253: ** when the connection currently holding the required lock relinquishes it.
        !          6254: ** ^This API is only available if the library was compiled with the
        !          6255: ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.
        !          6256: **
        !          6257: ** See Also: [Using the SQLite Unlock Notification Feature].
        !          6258: **
        !          6259: ** ^Shared-cache locks are released when a database connection concludes
        !          6260: ** its current transaction, either by committing it or rolling it back. 
        !          6261: **
        !          6262: ** ^When a connection (known as the blocked connection) fails to obtain a
        !          6263: ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the
        !          6264: ** identity of the database connection (the blocking connection) that
        !          6265: ** has locked the required resource is stored internally. ^After an 
        !          6266: ** application receives an SQLITE_LOCKED error, it may call the
        !          6267: ** sqlite3_unlock_notify() method with the blocked connection handle as 
        !          6268: ** the first argument to register for a callback that will be invoked
        !          6269: ** when the blocking connections current transaction is concluded. ^The
        !          6270: ** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
        !          6271: ** call that concludes the blocking connections transaction.
        !          6272: **
        !          6273: ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application,
        !          6274: ** there is a chance that the blocking connection will have already
        !          6275: ** concluded its transaction by the time sqlite3_unlock_notify() is invoked.
        !          6276: ** If this happens, then the specified callback is invoked immediately,
        !          6277: ** from within the call to sqlite3_unlock_notify().)^
        !          6278: **
        !          6279: ** ^If the blocked connection is attempting to obtain a write-lock on a
        !          6280: ** shared-cache table, and more than one other connection currently holds
        !          6281: ** a read-lock on the same table, then SQLite arbitrarily selects one of 
        !          6282: ** the other connections to use as the blocking connection.
        !          6283: **
        !          6284: ** ^(There may be at most one unlock-notify callback registered by a 
        !          6285: ** blocked connection. If sqlite3_unlock_notify() is called when the
        !          6286: ** blocked connection already has a registered unlock-notify callback,
        !          6287: ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is
        !          6288: ** called with a NULL pointer as its second argument, then any existing
        !          6289: ** unlock-notify callback is canceled. ^The blocked connections 
        !          6290: ** unlock-notify callback may also be canceled by closing the blocked
        !          6291: ** connection using [sqlite3_close()].
        !          6292: **
        !          6293: ** The unlock-notify callback is not reentrant. If an application invokes
        !          6294: ** any sqlite3_xxx API functions from within an unlock-notify callback, a
        !          6295: ** crash or deadlock may be the result.
        !          6296: **
        !          6297: ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always
        !          6298: ** returns SQLITE_OK.
        !          6299: **
        !          6300: ** <b>Callback Invocation Details</b>
        !          6301: **
        !          6302: ** When an unlock-notify callback is registered, the application provides a 
        !          6303: ** single void* pointer that is passed to the callback when it is invoked.
        !          6304: ** However, the signature of the callback function allows SQLite to pass
        !          6305: ** it an array of void* context pointers. The first argument passed to
        !          6306: ** an unlock-notify callback is a pointer to an array of void* pointers,
        !          6307: ** and the second is the number of entries in the array.
        !          6308: **
        !          6309: ** When a blocking connections transaction is concluded, there may be
        !          6310: ** more than one blocked connection that has registered for an unlock-notify
        !          6311: ** callback. ^If two or more such blocked connections have specified the
        !          6312: ** same callback function, then instead of invoking the callback function
        !          6313: ** multiple times, it is invoked once with the set of void* context pointers
        !          6314: ** specified by the blocked connections bundled together into an array.
        !          6315: ** This gives the application an opportunity to prioritize any actions 
        !          6316: ** related to the set of unblocked database connections.
        !          6317: **
        !          6318: ** <b>Deadlock Detection</b>
        !          6319: **
        !          6320: ** Assuming that after registering for an unlock-notify callback a 
        !          6321: ** database waits for the callback to be issued before taking any further
        !          6322: ** action (a reasonable assumption), then using this API may cause the
        !          6323: ** application to deadlock. For example, if connection X is waiting for
        !          6324: ** connection Y's transaction to be concluded, and similarly connection
        !          6325: ** Y is waiting on connection X's transaction, then neither connection
        !          6326: ** will proceed and the system may remain deadlocked indefinitely.
        !          6327: **
        !          6328: ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock
        !          6329: ** detection. ^If a given call to sqlite3_unlock_notify() would put the
        !          6330: ** system in a deadlocked state, then SQLITE_LOCKED is returned and no
        !          6331: ** unlock-notify callback is registered. The system is said to be in
        !          6332: ** a deadlocked state if connection A has registered for an unlock-notify
        !          6333: ** callback on the conclusion of connection B's transaction, and connection
        !          6334: ** B has itself registered for an unlock-notify callback when connection
        !          6335: ** A's transaction is concluded. ^Indirect deadlock is also detected, so
        !          6336: ** the system is also considered to be deadlocked if connection B has
        !          6337: ** registered for an unlock-notify callback on the conclusion of connection
        !          6338: ** C's transaction, where connection C is waiting on connection A. ^Any
        !          6339: ** number of levels of indirection are allowed.
        !          6340: **
        !          6341: ** <b>The "DROP TABLE" Exception</b>
        !          6342: **
        !          6343: ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 
        !          6344: ** always appropriate to call sqlite3_unlock_notify(). There is however,
        !          6345: ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,
        !          6346: ** SQLite checks if there are any currently executing SELECT statements
        !          6347: ** that belong to the same connection. If there are, SQLITE_LOCKED is
        !          6348: ** returned. In this case there is no "blocking connection", so invoking
        !          6349: ** sqlite3_unlock_notify() results in the unlock-notify callback being
        !          6350: ** invoked immediately. If the application then re-attempts the "DROP TABLE"
        !          6351: ** or "DROP INDEX" query, an infinite loop might be the result.
        !          6352: **
        !          6353: ** One way around this problem is to check the extended error code returned
        !          6354: ** by an sqlite3_step() call. ^(If there is a blocking connection, then the
        !          6355: ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in
        !          6356: ** the special "DROP TABLE/INDEX" case, the extended error code is just 
        !          6357: ** SQLITE_LOCKED.)^
        !          6358: */
        !          6359: SQLITE_API int sqlite3_unlock_notify(
        !          6360:   sqlite3 *pBlocked,                          /* Waiting connection */
        !          6361:   void (*xNotify)(void **apArg, int nArg),    /* Callback function to invoke */
        !          6362:   void *pNotifyArg                            /* Argument to pass to xNotify */
        !          6363: );
        !          6364: 
        !          6365: 
        !          6366: /*
        !          6367: ** CAPI3REF: String Comparison
        !          6368: **
        !          6369: ** ^The [sqlite3_strnicmp()] API allows applications and extensions to
        !          6370: ** compare the contents of two buffers containing UTF-8 strings in a
        !          6371: ** case-independent fashion, using the same definition of case independence 
        !          6372: ** that SQLite uses internally when comparing identifiers.
        !          6373: */
        !          6374: SQLITE_API int sqlite3_strnicmp(const char *, const char *, int);
        !          6375: 
        !          6376: /*
        !          6377: ** CAPI3REF: Error Logging Interface
        !          6378: **
        !          6379: ** ^The [sqlite3_log()] interface writes a message into the error log
        !          6380: ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
        !          6381: ** ^If logging is enabled, the zFormat string and subsequent arguments are
        !          6382: ** used with [sqlite3_snprintf()] to generate the final output string.
        !          6383: **
        !          6384: ** The sqlite3_log() interface is intended for use by extensions such as
        !          6385: ** virtual tables, collating functions, and SQL functions.  While there is
        !          6386: ** nothing to prevent an application from calling sqlite3_log(), doing so
        !          6387: ** is considered bad form.
        !          6388: **
        !          6389: ** The zFormat string must not be NULL.
        !          6390: **
        !          6391: ** To avoid deadlocks and other threading problems, the sqlite3_log() routine
        !          6392: ** will not use dynamically allocated memory.  The log message is stored in
        !          6393: ** a fixed-length buffer on the stack.  If the log message is longer than
        !          6394: ** a few hundred characters, it will be truncated to the length of the
        !          6395: ** buffer.
        !          6396: */
        !          6397: SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...);
        !          6398: 
        !          6399: /*
        !          6400: ** CAPI3REF: Write-Ahead Log Commit Hook
        !          6401: **
        !          6402: ** ^The [sqlite3_wal_hook()] function is used to register a callback that
        !          6403: ** will be invoked each time a database connection commits data to a
        !          6404: ** [write-ahead log] (i.e. whenever a transaction is committed in
        !          6405: ** [journal_mode | journal_mode=WAL mode]). 
        !          6406: **
        !          6407: ** ^The callback is invoked by SQLite after the commit has taken place and 
        !          6408: ** the associated write-lock on the database released, so the implementation 
        !          6409: ** may read, write or [checkpoint] the database as required.
        !          6410: **
        !          6411: ** ^The first parameter passed to the callback function when it is invoked
        !          6412: ** is a copy of the third parameter passed to sqlite3_wal_hook() when
        !          6413: ** registering the callback. ^The second is a copy of the database handle.
        !          6414: ** ^The third parameter is the name of the database that was written to -
        !          6415: ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter
        !          6416: ** is the number of pages currently in the write-ahead log file,
        !          6417: ** including those that were just committed.
        !          6418: **
        !          6419: ** The callback function should normally return [SQLITE_OK].  ^If an error
        !          6420: ** code is returned, that error will propagate back up through the
        !          6421: ** SQLite code base to cause the statement that provoked the callback
        !          6422: ** to report an error, though the commit will have still occurred. If the
        !          6423: ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value
        !          6424: ** that does not correspond to any valid SQLite error code, the results
        !          6425: ** are undefined.
        !          6426: **
        !          6427: ** A single database handle may have at most a single write-ahead log callback 
        !          6428: ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any
        !          6429: ** previously registered write-ahead log callback. ^Note that the
        !          6430: ** [sqlite3_wal_autocheckpoint()] interface and the
        !          6431: ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will
        !          6432: ** those overwrite any prior [sqlite3_wal_hook()] settings.
        !          6433: */
        !          6434: SQLITE_API void *sqlite3_wal_hook(
        !          6435:   sqlite3*, 
        !          6436:   int(*)(void *,sqlite3*,const char*,int),
        !          6437:   void*
        !          6438: );
        !          6439: 
        !          6440: /*
        !          6441: ** CAPI3REF: Configure an auto-checkpoint
        !          6442: **
        !          6443: ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around
        !          6444: ** [sqlite3_wal_hook()] that causes any database on [database connection] D
        !          6445: ** to automatically [checkpoint]
        !          6446: ** after committing a transaction if there are N or
        !          6447: ** more frames in the [write-ahead log] file.  ^Passing zero or 
        !          6448: ** a negative value as the nFrame parameter disables automatic
        !          6449: ** checkpoints entirely.
        !          6450: **
        !          6451: ** ^The callback registered by this function replaces any existing callback
        !          6452: ** registered using [sqlite3_wal_hook()].  ^Likewise, registering a callback
        !          6453: ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism
        !          6454: ** configured by this function.
        !          6455: **
        !          6456: ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface
        !          6457: ** from SQL.
        !          6458: **
        !          6459: ** ^Every new [database connection] defaults to having the auto-checkpoint
        !          6460: ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT]
        !          6461: ** pages.  The use of this interface
        !          6462: ** is only necessary if the default setting is found to be suboptimal
        !          6463: ** for a particular application.
        !          6464: */
        !          6465: SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N);
        !          6466: 
        !          6467: /*
        !          6468: ** CAPI3REF: Checkpoint a database
        !          6469: **
        !          6470: ** ^The [sqlite3_wal_checkpoint(D,X)] interface causes database named X
        !          6471: ** on [database connection] D to be [checkpointed].  ^If X is NULL or an
        !          6472: ** empty string, then a checkpoint is run on all databases of
        !          6473: ** connection D.  ^If the database connection D is not in
        !          6474: ** [WAL | write-ahead log mode] then this interface is a harmless no-op.
        !          6475: **
        !          6476: ** ^The [wal_checkpoint pragma] can be used to invoke this interface
        !          6477: ** from SQL.  ^The [sqlite3_wal_autocheckpoint()] interface and the
        !          6478: ** [wal_autocheckpoint pragma] can be used to cause this interface to be
        !          6479: ** run whenever the WAL reaches a certain size threshold.
        !          6480: **
        !          6481: ** See also: [sqlite3_wal_checkpoint_v2()]
        !          6482: */
        !          6483: SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb);
        !          6484: 
        !          6485: /*
        !          6486: ** CAPI3REF: Checkpoint a database
        !          6487: **
        !          6488: ** Run a checkpoint operation on WAL database zDb attached to database 
        !          6489: ** handle db. The specific operation is determined by the value of the 
        !          6490: ** eMode parameter:
        !          6491: **
        !          6492: ** <dl>
        !          6493: ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd>
        !          6494: **   Checkpoint as many frames as possible without waiting for any database 
        !          6495: **   readers or writers to finish. Sync the db file if all frames in the log
        !          6496: **   are checkpointed. This mode is the same as calling 
        !          6497: **   sqlite3_wal_checkpoint(). The busy-handler callback is never invoked.
        !          6498: **
        !          6499: ** <dt>SQLITE_CHECKPOINT_FULL<dd>
        !          6500: **   This mode blocks (calls the busy-handler callback) until there is no
        !          6501: **   database writer and all readers are reading from the most recent database
        !          6502: **   snapshot. It then checkpoints all frames in the log file and syncs the
        !          6503: **   database file. This call blocks database writers while it is running,
        !          6504: **   but not database readers.
        !          6505: **
        !          6506: ** <dt>SQLITE_CHECKPOINT_RESTART<dd>
        !          6507: **   This mode works the same way as SQLITE_CHECKPOINT_FULL, except after 
        !          6508: **   checkpointing the log file it blocks (calls the busy-handler callback)
        !          6509: **   until all readers are reading from the database file only. This ensures 
        !          6510: **   that the next client to write to the database file restarts the log file 
        !          6511: **   from the beginning. This call blocks database writers while it is running,
        !          6512: **   but not database readers.
        !          6513: ** </dl>
        !          6514: **
        !          6515: ** If pnLog is not NULL, then *pnLog is set to the total number of frames in
        !          6516: ** the log file before returning. If pnCkpt is not NULL, then *pnCkpt is set to
        !          6517: ** the total number of checkpointed frames (including any that were already
        !          6518: ** checkpointed when this function is called). *pnLog and *pnCkpt may be
        !          6519: ** populated even if sqlite3_wal_checkpoint_v2() returns other than SQLITE_OK.
        !          6520: ** If no values are available because of an error, they are both set to -1
        !          6521: ** before returning to communicate this to the caller.
        !          6522: **
        !          6523: ** All calls obtain an exclusive "checkpoint" lock on the database file. If
        !          6524: ** any other process is running a checkpoint operation at the same time, the 
        !          6525: ** lock cannot be obtained and SQLITE_BUSY is returned. Even if there is a 
        !          6526: ** busy-handler configured, it will not be invoked in this case.
        !          6527: **
        !          6528: ** The SQLITE_CHECKPOINT_FULL and RESTART modes also obtain the exclusive 
        !          6529: ** "writer" lock on the database file. If the writer lock cannot be obtained
        !          6530: ** immediately, and a busy-handler is configured, it is invoked and the writer
        !          6531: ** lock retried until either the busy-handler returns 0 or the lock is
        !          6532: ** successfully obtained. The busy-handler is also invoked while waiting for
        !          6533: ** database readers as described above. If the busy-handler returns 0 before
        !          6534: ** the writer lock is obtained or while waiting for database readers, the
        !          6535: ** checkpoint operation proceeds from that point in the same way as 
        !          6536: ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 
        !          6537: ** without blocking any further. SQLITE_BUSY is returned in this case.
        !          6538: **
        !          6539: ** If parameter zDb is NULL or points to a zero length string, then the
        !          6540: ** specified operation is attempted on all WAL databases. In this case the
        !          6541: ** values written to output parameters *pnLog and *pnCkpt are undefined. If 
        !          6542: ** an SQLITE_BUSY error is encountered when processing one or more of the 
        !          6543: ** attached WAL databases, the operation is still attempted on any remaining 
        !          6544: ** attached databases and SQLITE_BUSY is returned to the caller. If any other 
        !          6545: ** error occurs while processing an attached database, processing is abandoned 
        !          6546: ** and the error code returned to the caller immediately. If no error 
        !          6547: ** (SQLITE_BUSY or otherwise) is encountered while processing the attached 
        !          6548: ** databases, SQLITE_OK is returned.
        !          6549: **
        !          6550: ** If database zDb is the name of an attached database that is not in WAL
        !          6551: ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. If
        !          6552: ** zDb is not NULL (or a zero length string) and is not the name of any
        !          6553: ** attached database, SQLITE_ERROR is returned to the caller.
        !          6554: */
        !          6555: SQLITE_API int sqlite3_wal_checkpoint_v2(
        !          6556:   sqlite3 *db,                    /* Database handle */
        !          6557:   const char *zDb,                /* Name of attached database (or NULL) */
        !          6558:   int eMode,                      /* SQLITE_CHECKPOINT_* value */
        !          6559:   int *pnLog,                     /* OUT: Size of WAL log in frames */
        !          6560:   int *pnCkpt                     /* OUT: Total number of frames checkpointed */
        !          6561: );
        !          6562: 
        !          6563: /*
        !          6564: ** CAPI3REF: Checkpoint operation parameters
        !          6565: **
        !          6566: ** These constants can be used as the 3rd parameter to
        !          6567: ** [sqlite3_wal_checkpoint_v2()].  See the [sqlite3_wal_checkpoint_v2()]
        !          6568: ** documentation for additional information about the meaning and use of
        !          6569: ** each of these values.
        !          6570: */
        !          6571: #define SQLITE_CHECKPOINT_PASSIVE 0
        !          6572: #define SQLITE_CHECKPOINT_FULL    1
        !          6573: #define SQLITE_CHECKPOINT_RESTART 2
        !          6574: 
        !          6575: /*
        !          6576: ** CAPI3REF: Virtual Table Interface Configuration
        !          6577: **
        !          6578: ** This function may be called by either the [xConnect] or [xCreate] method
        !          6579: ** of a [virtual table] implementation to configure
        !          6580: ** various facets of the virtual table interface.
        !          6581: **
        !          6582: ** If this interface is invoked outside the context of an xConnect or
        !          6583: ** xCreate virtual table method then the behavior is undefined.
        !          6584: **
        !          6585: ** At present, there is only one option that may be configured using
        !          6586: ** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].)  Further options
        !          6587: ** may be added in the future.
        !          6588: */
        !          6589: SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...);
        !          6590: 
        !          6591: /*
        !          6592: ** CAPI3REF: Virtual Table Configuration Options
        !          6593: **
        !          6594: ** These macros define the various options to the
        !          6595: ** [sqlite3_vtab_config()] interface that [virtual table] implementations
        !          6596: ** can use to customize and optimize their behavior.
        !          6597: **
        !          6598: ** <dl>
        !          6599: ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT
        !          6600: ** <dd>Calls of the form
        !          6601: ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported,
        !          6602: ** where X is an integer.  If X is zero, then the [virtual table] whose
        !          6603: ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not
        !          6604: ** support constraints.  In this configuration (which is the default) if
        !          6605: ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire
        !          6606: ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been
        !          6607: ** specified as part of the users SQL statement, regardless of the actual
        !          6608: ** ON CONFLICT mode specified.
        !          6609: **
        !          6610: ** If X is non-zero, then the virtual table implementation guarantees
        !          6611: ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before
        !          6612: ** any modifications to internal or persistent data structures have been made.
        !          6613: ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 
        !          6614: ** is able to roll back a statement or database transaction, and abandon
        !          6615: ** or continue processing the current SQL statement as appropriate. 
        !          6616: ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns
        !          6617: ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode
        !          6618: ** had been ABORT.
        !          6619: **
        !          6620: ** Virtual table implementations that are required to handle OR REPLACE
        !          6621: ** must do so within the [xUpdate] method. If a call to the 
        !          6622: ** [sqlite3_vtab_on_conflict()] function indicates that the current ON 
        !          6623: ** CONFLICT policy is REPLACE, the virtual table implementation should 
        !          6624: ** silently replace the appropriate rows within the xUpdate callback and
        !          6625: ** return SQLITE_OK. Or, if this is not possible, it may return
        !          6626: ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 
        !          6627: ** constraint handling.
        !          6628: ** </dl>
        !          6629: */
        !          6630: #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1
        !          6631: 
        !          6632: /*
        !          6633: ** CAPI3REF: Determine The Virtual Table Conflict Policy
        !          6634: **
        !          6635: ** This function may only be called from within a call to the [xUpdate] method
        !          6636: ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The
        !          6637: ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL],
        !          6638: ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode
        !          6639: ** of the SQL statement that triggered the call to the [xUpdate] method of the
        !          6640: ** [virtual table].
        !          6641: */
        !          6642: SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *);
        !          6643: 
        !          6644: /*
        !          6645: ** CAPI3REF: Conflict resolution modes
        !          6646: **
        !          6647: ** These constants are returned by [sqlite3_vtab_on_conflict()] to
        !          6648: ** inform a [virtual table] implementation what the [ON CONFLICT] mode
        !          6649: ** is for the SQL statement being evaluated.
        !          6650: **
        !          6651: ** Note that the [SQLITE_IGNORE] constant is also used as a potential
        !          6652: ** return value from the [sqlite3_set_authorizer()] callback and that
        !          6653: ** [SQLITE_ABORT] is also a [result code].
        !          6654: */
        !          6655: #define SQLITE_ROLLBACK 1
        !          6656: /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */
        !          6657: #define SQLITE_FAIL     3
        !          6658: /* #define SQLITE_ABORT 4  // Also an error code */
        !          6659: #define SQLITE_REPLACE  5
        !          6660: 
        !          6661: 
        !          6662: 
        !          6663: /*
        !          6664: ** Undo the hack that converts floating point types to integer for
        !          6665: ** builds on processors without floating point support.
        !          6666: */
        !          6667: #ifdef SQLITE_OMIT_FLOATING_POINT
        !          6668: # undef double
        !          6669: #endif
        !          6670: 
        !          6671: #ifdef __cplusplus
        !          6672: }  /* End of the 'extern "C"' block */
        !          6673: #endif
        !          6674: #endif
        !          6675: 
        !          6676: /*
        !          6677: ** 2010 August 30
        !          6678: **
        !          6679: ** The author disclaims copyright to this source code.  In place of
        !          6680: ** a legal notice, here is a blessing:
        !          6681: **
        !          6682: **    May you do good and not evil.
        !          6683: **    May you find forgiveness for yourself and forgive others.
        !          6684: **    May you share freely, never taking more than you give.
        !          6685: **
        !          6686: *************************************************************************
        !          6687: */
        !          6688: 
        !          6689: #ifndef _SQLITE3RTREE_H_
        !          6690: #define _SQLITE3RTREE_H_
        !          6691: 
        !          6692: 
        !          6693: #ifdef __cplusplus
        !          6694: extern "C" {
        !          6695: #endif
        !          6696: 
        !          6697: typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;
        !          6698: 
        !          6699: /*
        !          6700: ** Register a geometry callback named zGeom that can be used as part of an
        !          6701: ** R-Tree geometry query as follows:
        !          6702: **
        !          6703: **   SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...)
        !          6704: */
        !          6705: SQLITE_API int sqlite3_rtree_geometry_callback(
        !          6706:   sqlite3 *db,
        !          6707:   const char *zGeom,
        !          6708:   int (*xGeom)(sqlite3_rtree_geometry *, int nCoord, double *aCoord, int *pRes),
        !          6709:   void *pContext
        !          6710: );
        !          6711: 
        !          6712: 
        !          6713: /*
        !          6714: ** A pointer to a structure of the following type is passed as the first
        !          6715: ** argument to callbacks registered using rtree_geometry_callback().
        !          6716: */
        !          6717: struct sqlite3_rtree_geometry {
        !          6718:   void *pContext;                 /* Copy of pContext passed to s_r_g_c() */
        !          6719:   int nParam;                     /* Size of array aParam[] */
        !          6720:   double *aParam;                 /* Parameters passed to SQL geom function */
        !          6721:   void *pUser;                    /* Callback implementation user data */
        !          6722:   void (*xDelUser)(void *);       /* Called by SQLite to clean up pUser */
        !          6723: };
        !          6724: 
        !          6725: 
        !          6726: #ifdef __cplusplus
        !          6727: }  /* end of the 'extern "C"' block */
        !          6728: #endif
        !          6729: 
        !          6730: #endif  /* ifndef _SQLITE3RTREE_H_ */
        !          6731: 

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