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E:/Projetos_Primeiro_Semestre_2012/TerraView/terralib/src/terralib/drivers/SQLite/sqlite3/sqlite3.h
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    00001 /*
    00002 ** 2001 September 15
    00003 **
    00004 ** The author disclaims copyright to this source code.  In place of
    00005 ** a legal notice, here is a blessing:
    00006 **
    00007 **    May you do good and not evil.
    00008 **    May you find forgiveness for yourself and forgive others.
    00009 **    May you share freely, never taking more than you give.
    00010 **
    00011 *************************************************************************
    00012 ** This header file defines the interface that the SQLite library
    00013 ** presents to client programs.  If a C-function, structure, datatype,
    00014 ** or constant definition does not appear in this file, then it is
    00015 ** not a published API of SQLite, is subject to change without
    00016 ** notice, and should not be referenced by programs that use SQLite.
    00017 **
    00018 ** Some of the definitions that are in this file are marked as
    00019 ** "experimental".  Experimental interfaces are normally new
    00020 ** features recently added to SQLite.  We do not anticipate changes
    00021 ** to experimental interfaces but reserve the right to make minor changes
    00022 ** if experience from use "in the wild" suggest such changes are prudent.
    00023 **
    00024 ** The official C-language API documentation for SQLite is derived
    00025 ** from comments in this file.  This file is the authoritative source
    00026 ** on how SQLite interfaces are suppose to operate.
    00027 **
    00028 ** The name of this file under configuration management is "sqlite.h.in".
    00029 ** The makefile makes some minor changes to this file (such as inserting
    00030 ** the version number) and changes its name to "sqlite3.h" as
    00031 ** part of the build process.
    00032 */
    00033 #ifndef _SQLITE3_H_
    00034 #define _SQLITE3_H_
    00035 #include <stdarg.h>     /* Needed for the definition of va_list */
    00036
    00037 /*
    00038 ** Make sure we can call this stuff from C++.
    00039 */
    00040 #ifdef __cplusplus
    00041 extern "C" {
    00042 #endif
    00043
    00044
    00045 /*
    00046 ** Add the ability to override 'extern'
    00047 */
    00048 #ifndef SQLITE_EXTERN
    00049 # define SQLITE_EXTERN extern
    00050 #endif
    00051
    00052 #ifndef SQLITE_API
    00053 # define SQLITE_API
    00054 #endif
    00055
    00056
    00057 /*
    00058 ** These no-op macros are used in front of interfaces to mark those
    00059 ** interfaces as either deprecated or experimental.  New applications
    00060 ** should not use deprecated interfaces - they are support for backwards
    00061 ** compatibility only.  Application writers should be aware that
    00062 ** experimental interfaces are subject to change in point releases.
    00063 **
    00064 ** These macros used to resolve to various kinds of compiler magic that
    00065 ** would generate warning messages when they were used.  But that
    00066 ** compiler magic ended up generating such a flurry of bug reports
    00067 ** that we have taken it all out and gone back to using simple
    00068 ** noop macros.
    00069 */
    00070 #define SQLITE_DEPRECATED
    00071 #define SQLITE_EXPERIMENTAL
    00072
    00073 /*
    00074 ** Ensure these symbols were not defined by some previous header file.
    00075 */
    00076 #ifdef SQLITE_VERSION
    00077 # undef SQLITE_VERSION
    00078 #endif
    00079 #ifdef SQLITE_VERSION_NUMBER
    00080 # undef SQLITE_VERSION_NUMBER
    00081 #endif
    00082
    00083 /*
    00084 ** CAPI3REF: Compile-Time Library Version Numbers
    00085 **
    00086 ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header
    00087 ** evaluates to a string literal that is the SQLite version in the
    00088 ** format "X.Y.Z" where X is the major version number (always 3 for
    00089 ** SQLite3) and Y is the minor version number and Z is the release number.)^
    00090 ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer
    00091 ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same
    00092 ** numbers used in [SQLITE_VERSION].)^
    00093 ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also
    00094 ** be larger than the release from which it is derived.  Either Y will
    00095 ** be held constant and Z will be incremented or else Y will be incremented
    00096 ** and Z will be reset to zero.
    00097 **
    00098 ** Since version 3.6.18, SQLite source code has been stored in the
    00099 ** <a href="http://www.fossil-scm.org/">Fossil configuration management
    00100 ** system</a>.  ^The SQLITE_SOURCE_ID macro evaluates to
    00101 ** a string which identifies a particular check-in of SQLite
    00102 ** within its configuration management system.  ^The SQLITE_SOURCE_ID
    00103 ** string contains the date and time of the check-in (UTC) and an SHA1
    00104 ** hash of the entire source tree.
    00105 **
    00106 ** See also: [sqlite3_libversion()],
    00107 ** [sqlite3_libversion_number()], [sqlite3_sourceid()],
    00108 ** [sqlite_version()] and [sqlite_source_id()].
    00109 */
    00110 #define SQLITE_VERSION        "3.7.9"
    00111 #define SQLITE_VERSION_NUMBER 3007009
    00112 #define SQLITE_SOURCE_ID      "2011-11-01 00:52:41 c7c6050ef060877ebe77b41d959e9df13f8c9b5e"
    00113
    00114 /*
    00115 ** CAPI3REF: Run-Time Library Version Numbers
    00116 ** KEYWORDS: sqlite3_version, sqlite3_sourceid
    00117 **
    00118 ** These interfaces provide the same information as the [SQLITE_VERSION],
    00119 ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
    00120 ** but are associated with the library instead of the header file.  ^(Cautious
    00121 ** programmers might include assert() statements in their application to
    00122 ** verify that values returned by these interfaces match the macros in
    00123 ** the header, and thus insure that the application is
    00124 ** compiled with matching library and header files.
    00125 **
    00126 ** <blockquote><pre>
    00127 ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
    00128 ** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 );
    00129 ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
    00130 ** </pre></blockquote>)^
    00131 **
    00132 ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION]
    00133 ** macro.  ^The sqlite3_libversion() function returns a pointer to the
    00134 ** to the sqlite3_version[] string constant.  The sqlite3_libversion()
    00135 ** function is provided for use in DLLs since DLL users usually do not have
    00136 ** direct access to string constants within the DLL.  ^The
    00137 ** sqlite3_libversion_number() function returns an integer equal to
    00138 ** [SQLITE_VERSION_NUMBER].  ^The sqlite3_sourceid() function returns
    00139 ** a pointer to a string constant whose value is the same as the
    00140 ** [SQLITE_SOURCE_ID] C preprocessor macro.
    00141 **
    00142 ** See also: [sqlite_version()] and [sqlite_source_id()].
    00143 */
    00144 SQLITE_API SQLITE_EXTERN const char sqlite3_version[];
    00145 SQLITE_API const char *sqlite3_libversion(void);
    00146 SQLITE_API const char *sqlite3_sourceid(void);
    00147 SQLITE_API int sqlite3_libversion_number(void);
    00148
    00149 /*
    00150 ** CAPI3REF: Run-Time Library Compilation Options Diagnostics
    00151 **
    00152 ** ^The sqlite3_compileoption_used() function returns 0 or 1
    00153 ** indicating whether the specified option was defined at
    00154 ** compile time.  ^The SQLITE_ prefix may be omitted from the
    00155 ** option name passed to sqlite3_compileoption_used().
    00156 **
    00157 ** ^The sqlite3_compileoption_get() function allows iterating
    00158 ** over the list of options that were defined at compile time by
    00159 ** returning the N-th compile time option string.  ^If N is out of range,
    00160 ** sqlite3_compileoption_get() returns a NULL pointer.  ^The SQLITE_
    00161 ** prefix is omitted from any strings returned by
    00162 ** sqlite3_compileoption_get().
    00163 **
    00164 ** ^Support for the diagnostic functions sqlite3_compileoption_used()
    00165 ** and sqlite3_compileoption_get() may be omitted by specifying the
    00166 ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time.
    00167 **
    00168 ** See also: SQL functions [sqlite_compileoption_used()] and
    00169 ** [sqlite_compileoption_get()] and the [compile_options pragma].
    00170 */
    00171 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
    00172 SQLITE_API int sqlite3_compileoption_used(const char *zOptName);
    00173 SQLITE_API const char *sqlite3_compileoption_get(int N);
    00174 #endif
    00175
    00176 /*
    00177 ** CAPI3REF: Test To See If The Library Is Threadsafe
    00178 **
    00179 ** ^The sqlite3_threadsafe() function returns zero if and only if
    00180 ** SQLite was compiled mutexing code omitted due to the
    00181 ** [SQLITE_THREADSAFE] compile-time option being set to 0.
    00182 **
    00183 ** SQLite can be compiled with or without mutexes.  When
    00184 ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes
    00185 ** are enabled and SQLite is threadsafe.  When the
    00186 ** [SQLITE_THREADSAFE] macro is 0,
    00187 ** the mutexes are omitted.  Without the mutexes, it is not safe
    00188 ** to use SQLite concurrently from more than one thread.
    00189 **
    00190 ** Enabling mutexes incurs a measurable performance penalty.
    00191 ** So if speed is of utmost importance, it makes sense to disable
    00192 ** the mutexes.  But for maximum safety, mutexes should be enabled.
    00193 ** ^The default behavior is for mutexes to be enabled.
    00194 **
    00195 ** This interface can be used by an application to make sure that the
    00196 ** version of SQLite that it is linking against was compiled with
    00197 ** the desired setting of the [SQLITE_THREADSAFE] macro.
    00198 **
    00199 ** This interface only reports on the compile-time mutex setting
    00200 ** of the [SQLITE_THREADSAFE] flag.  If SQLite is compiled with
    00201 ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but
    00202 ** can be fully or partially disabled using a call to [sqlite3_config()]
    00203 ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],
    00204 ** or [SQLITE_CONFIG_MUTEX].  ^(The return value of the
    00205 ** sqlite3_threadsafe() function shows only the compile-time setting of
    00206 ** thread safety, not any run-time changes to that setting made by
    00207 ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()
    00208 ** is unchanged by calls to sqlite3_config().)^
    00209 **
    00210 ** See the [threading mode] documentation for additional information.
    00211 */
    00212 SQLITE_API int sqlite3_threadsafe(void);
    00213
    00214 /*
    00215 ** CAPI3REF: Database Connection Handle
    00216 ** KEYWORDS: {database connection} {database connections}
    00217 **
    00218 ** Each open SQLite database is represented by a pointer to an instance of
    00219 ** the opaque structure named "sqlite3".  It is useful to think of an sqlite3
    00220 ** pointer as an object.  The [sqlite3_open()], [sqlite3_open16()], and
    00221 ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
    00222 ** is its destructor.  There are many other interfaces (such as
    00223 ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
    00224 ** [sqlite3_busy_timeout()] to name but three) that are methods on an
    00225 ** sqlite3 object.
    00226 */
    00227 typedef struct sqlite3 sqlite3;
    00228
    00229 /*
    00230 ** CAPI3REF: 64-Bit Integer Types
    00231 ** KEYWORDS: sqlite_int64 sqlite_uint64
    00232 **
    00233 ** Because there is no cross-platform way to specify 64-bit integer types
    00234 ** SQLite includes typedefs for 64-bit signed and unsigned integers.
    00235 **
    00236 ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
    00237 ** The sqlite_int64 and sqlite_uint64 types are supported for backwards
    00238 ** compatibility only.
    00239 **
    00240 ** ^The sqlite3_int64 and sqlite_int64 types can store integer values
    00241 ** between -9223372036854775808 and +9223372036854775807 inclusive.  ^The
    00242 ** sqlite3_uint64 and sqlite_uint64 types can store integer values
    00243 ** between 0 and +18446744073709551615 inclusive.
    00244 */
    00245 #ifdef SQLITE_INT64_TYPE
    00246   typedef SQLITE_INT64_TYPE sqlite_int64;
    00247   typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
    00248 #elif defined(_MSC_VER) || defined(__BORLANDC__)
    00249   typedef __int64 sqlite_int64;
    00250   typedef unsigned __int64 sqlite_uint64;
    00251 #else
    00252   typedef long long int sqlite_int64;
    00253   typedef unsigned long long int sqlite_uint64;
    00254 #endif
    00255 typedef sqlite_int64 sqlite3_int64;
    00256 typedef sqlite_uint64 sqlite3_uint64;
    00257
    00258 /*
    00259 ** If compiling for a processor that lacks floating point support,
    00260 ** substitute integer for floating-point.
    00261 */
    00262 #ifdef SQLITE_OMIT_FLOATING_POINT
    00263 # define double sqlite3_int64
    00264 #endif
    00265
    00266 /*
    00267 ** CAPI3REF: Closing A Database Connection
    00268 **
    00269 ** ^The sqlite3_close() routine is the destructor for the [sqlite3] object.
    00270 ** ^Calls to sqlite3_close() return SQLITE_OK if the [sqlite3] object is
    00271 ** successfully destroyed and all associated resources are deallocated.
    00272 **
    00273 ** Applications must [sqlite3_finalize | finalize] all [prepared statements]
    00274 ** and [sqlite3_blob_close | close] all [BLOB handles] associated with
    00275 ** the [sqlite3] object prior to attempting to close the object.  ^If
    00276 ** sqlite3_close() is called on a [database connection] that still has
    00277 ** outstanding [prepared statements] or [BLOB handles], then it returns
    00278 ** SQLITE_BUSY.
    00279 **
    00280 ** ^If [sqlite3_close()] is invoked while a transaction is open,
    00281 ** the transaction is automatically rolled back.
    00282 **
    00283 ** The C parameter to [sqlite3_close(C)] must be either a NULL
    00284 ** pointer or an [sqlite3] object pointer obtained
    00285 ** from [sqlite3_open()], [sqlite3_open16()], or
    00286 ** [sqlite3_open_v2()], and not previously closed.
    00287 ** ^Calling sqlite3_close() with a NULL pointer argument is a
    00288 ** harmless no-op.
    00289 */
    00290 SQLITE_API int sqlite3_close(sqlite3 *);
    00291
    00292 /*
    00293 ** The type for a callback function.
    00294 ** This is legacy and deprecated.  It is included for historical
    00295 ** compatibility and is not documented.
    00296 */
    00297 typedef int (*sqlite3_callback)(void*,int,char**, char**);
    00298
    00299 /*
    00300 ** CAPI3REF: One-Step Query Execution Interface
    00301 **
    00302 ** The sqlite3_exec() interface is a convenience wrapper around
    00303 ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
    00304 ** that allows an application to run multiple statements of SQL
    00305 ** without having to use a lot of C code.
    00306 **
    00307 ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,
    00308 ** semicolon-separate SQL statements passed into its 2nd argument,
    00309 ** in the context of the [database connection] passed in as its 1st
    00310 ** argument.  ^If the callback function of the 3rd argument to
    00311 ** sqlite3_exec() is not NULL, then it is invoked for each result row
    00312 ** coming out of the evaluated SQL statements.  ^The 4th argument to
    00313 ** sqlite3_exec() is relayed through to the 1st argument of each
    00314 ** callback invocation.  ^If the callback pointer to sqlite3_exec()
    00315 ** is NULL, then no callback is ever invoked and result rows are
    00316 ** ignored.
    00317 **
    00318 ** ^If an error occurs while evaluating the SQL statements passed into
    00319 ** sqlite3_exec(), then execution of the current statement stops and
    00320 ** subsequent statements are skipped.  ^If the 5th parameter to sqlite3_exec()
    00321 ** is not NULL then any error message is written into memory obtained
    00322 ** from [sqlite3_malloc()] and passed back through the 5th parameter.
    00323 ** To avoid memory leaks, the application should invoke [sqlite3_free()]
    00324 ** on error message strings returned through the 5th parameter of
    00325 ** of sqlite3_exec() after the error message string is no longer needed.
    00326 ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
    00327 ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
    00328 ** NULL before returning.
    00329 **
    00330 ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
    00331 ** routine returns SQLITE_ABORT without invoking the callback again and
    00332 ** without running any subsequent SQL statements.
    00333 **
    00334 ** ^The 2nd argument to the sqlite3_exec() callback function is the
    00335 ** number of columns in the result.  ^The 3rd argument to the sqlite3_exec()
    00336 ** callback is an array of pointers to strings obtained as if from
    00337 ** [sqlite3_column_text()], one for each column.  ^If an element of a
    00338 ** result row is NULL then the corresponding string pointer for the
    00339 ** sqlite3_exec() callback is a NULL pointer.  ^The 4th argument to the
    00340 ** sqlite3_exec() callback is an array of pointers to strings where each
    00341 ** entry represents the name of corresponding result column as obtained
    00342 ** from [sqlite3_column_name()].
    00343 **
    00344 ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer
    00345 ** to an empty string, or a pointer that contains only whitespace and/or
    00346 ** SQL comments, then no SQL statements are evaluated and the database
    00347 ** is not changed.
    00348 **
    00349 ** Restrictions:
    00350 **
    00351 ** <ul>
    00352 ** <li> The application must insure that the 1st parameter to sqlite3_exec()
    00353 **      is a valid and open [database connection].
    00354 ** <li> The application must not close [database connection] specified by
    00355 **      the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
    00356 ** <li> The application must not modify the SQL statement text passed into
    00357 **      the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
    00358 ** </ul>
    00359 */
    00360 SQLITE_API int sqlite3_exec(
    00361   sqlite3*,                                  /* An open database */
    00362   const char *sql,                           /* SQL to be evaluated */
    00363   int (*callback)(void*,int,char**,char**),  /* Callback function */
    00364   void *,                                    /* 1st argument to callback */
    00365   char **errmsg                              /* Error msg written here */
    00366 );
    00367
    00368 /*
    00369 ** CAPI3REF: Result Codes
    00370 ** KEYWORDS: SQLITE_OK {error code} {error codes}
    00371 ** KEYWORDS: {result code} {result codes}
    00372 **
    00373 ** Many SQLite functions return an integer result code from the set shown
    00374 ** here in order to indicates success or failure.
    00375 **
    00376 ** New error codes may be added in future versions of SQLite.
    00377 **
    00378 ** See also: [SQLITE_IOERR_READ | extended result codes],
    00379 ** [sqlite3_vtab_on_conflict()] [SQLITE_ROLLBACK | result codes].
    00380 */
    00381 #define SQLITE_OK           0   /* Successful result */
    00382 /* beginning-of-error-codes */
    00383 #define SQLITE_ERROR        1   /* SQL error or missing database */
    00384 #define SQLITE_INTERNAL     2   /* Internal logic error in SQLite */
    00385 #define SQLITE_PERM         3   /* Access permission denied */
    00386 #define SQLITE_ABORT        4   /* Callback routine requested an abort */
    00387 #define SQLITE_BUSY         5   /* The database file is locked */
    00388 #define SQLITE_LOCKED       6   /* A table in the database is locked */
    00389 #define SQLITE_NOMEM        7   /* A malloc() failed */
    00390 #define SQLITE_READONLY     8   /* Attempt to write a readonly database */
    00391 #define SQLITE_INTERRUPT    9   /* Operation terminated by sqlite3_interrupt()*/
    00392 #define SQLITE_IOERR       10   /* Some kind of disk I/O error occurred */
    00393 #define SQLITE_CORRUPT     11   /* The database disk image is malformed */
    00394 #define SQLITE_NOTFOUND    12   /* Unknown opcode in sqlite3_file_control() */
    00395 #define SQLITE_FULL        13   /* Insertion failed because database is full */
    00396 #define SQLITE_CANTOPEN    14   /* Unable to open the database file */
    00397 #define SQLITE_PROTOCOL    15   /* Database lock protocol error */
    00398 #define SQLITE_EMPTY       16   /* Database is empty */
    00399 #define SQLITE_SCHEMA      17   /* The database schema changed */
    00400 #define SQLITE_TOOBIG      18   /* String or BLOB exceeds size limit */
    00401 #define SQLITE_CONSTRAINT  19   /* Abort due to constraint violation */
    00402 #define SQLITE_MISMATCH    20   /* Data type mismatch */
    00403 #define SQLITE_MISUSE      21   /* Library used incorrectly */
    00404 #define SQLITE_NOLFS       22   /* Uses OS features not supported on host */
    00405 #define SQLITE_AUTH        23   /* Authorization denied */
    00406 #define SQLITE_FORMAT      24   /* Auxiliary database format error */
    00407 #define SQLITE_RANGE       25   /* 2nd parameter to sqlite3_bind out of range */
    00408 #define SQLITE_NOTADB      26   /* File opened that is not a database file */
    00409 #define SQLITE_ROW         100  /* sqlite3_step() has another row ready */
    00410 #define SQLITE_DONE        101  /* sqlite3_step() has finished executing */
    00411 /* end-of-error-codes */
    00412
    00413 /*
    00414 ** CAPI3REF: Extended Result Codes
    00415 ** KEYWORDS: {extended error code} {extended error codes}
    00416 ** KEYWORDS: {extended result code} {extended result codes}
    00417 **
    00418 ** In its default configuration, SQLite API routines return one of 26 integer
    00419 ** [SQLITE_OK | result codes].  However, experience has shown that many of
    00420 ** these result codes are too coarse-grained.  They do not provide as
    00421 ** much information about problems as programmers might like.  In an effort to
    00422 ** address this, newer versions of SQLite (version 3.3.8 and later) include
    00423 ** support for additional result codes that provide more detailed information
    00424 ** about errors. The extended result codes are enabled or disabled
    00425 ** on a per database connection basis using the
    00426 ** [sqlite3_extended_result_codes()] API.
    00427 **
    00428 ** Some of the available extended result codes are listed here.
    00429 ** One may expect the number of extended result codes will be expand
    00430 ** over time.  Software that uses extended result codes should expect
    00431 ** to see new result codes in future releases of SQLite.
    00432 **
    00433 ** The SQLITE_OK result code will never be extended.  It will always
    00434 ** be exactly zero.
    00435 */
    00436 #define SQLITE_IOERR_READ              (SQLITE_IOERR | (1<<8))
    00437 #define SQLITE_IOERR_SHORT_READ        (SQLITE_IOERR | (2<<8))
    00438 #define SQLITE_IOERR_WRITE             (SQLITE_IOERR | (3<<8))
    00439 #define SQLITE_IOERR_FSYNC             (SQLITE_IOERR | (4<<8))
    00440 #define SQLITE_IOERR_DIR_FSYNC         (SQLITE_IOERR | (5<<8))
    00441 #define SQLITE_IOERR_TRUNCATE          (SQLITE_IOERR | (6<<8))
    00442 #define SQLITE_IOERR_FSTAT             (SQLITE_IOERR | (7<<8))
    00443 #define SQLITE_IOERR_UNLOCK            (SQLITE_IOERR | (8<<8))
    00444 #define SQLITE_IOERR_RDLOCK            (SQLITE_IOERR | (9<<8))
    00445 #define SQLITE_IOERR_DELETE            (SQLITE_IOERR | (10<<8))
    00446 #define SQLITE_IOERR_BLOCKED           (SQLITE_IOERR | (11<<8))
    00447 #define SQLITE_IOERR_NOMEM             (SQLITE_IOERR | (12<<8))
    00448 #define SQLITE_IOERR_ACCESS            (SQLITE_IOERR | (13<<8))
    00449 #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8))
    00450 #define SQLITE_IOERR_LOCK              (SQLITE_IOERR | (15<<8))
    00451 #define SQLITE_IOERR_CLOSE             (SQLITE_IOERR | (16<<8))
    00452 #define SQLITE_IOERR_DIR_CLOSE         (SQLITE_IOERR | (17<<8))
    00453 #define SQLITE_IOERR_SHMOPEN           (SQLITE_IOERR | (18<<8))
    00454 #define SQLITE_IOERR_SHMSIZE           (SQLITE_IOERR | (19<<8))
    00455 #define SQLITE_IOERR_SHMLOCK           (SQLITE_IOERR | (20<<8))
    00456 #define SQLITE_IOERR_SHMMAP            (SQLITE_IOERR | (21<<8))
    00457 #define SQLITE_IOERR_SEEK              (SQLITE_IOERR | (22<<8))
    00458 #define SQLITE_LOCKED_SHAREDCACHE      (SQLITE_LOCKED |  (1<<8))
    00459 #define SQLITE_BUSY_RECOVERY           (SQLITE_BUSY   |  (1<<8))
    00460 #define SQLITE_CANTOPEN_NOTEMPDIR      (SQLITE_CANTOPEN | (1<<8))
    00461 #define SQLITE_CORRUPT_VTAB            (SQLITE_CORRUPT | (1<<8))
    00462 #define SQLITE_READONLY_RECOVERY       (SQLITE_READONLY | (1<<8))
    00463 #define SQLITE_READONLY_CANTLOCK       (SQLITE_READONLY | (2<<8))
    00464
    00465 /*
    00466 ** CAPI3REF: Flags For File Open Operations
    00467 **
    00468 ** These bit values are intended for use in the
    00469 ** 3rd parameter to the [sqlite3_open_v2()] interface and
    00470 ** in the 4th parameter to the [sqlite3_vfs.xOpen] method.
    00471 */
    00472 #define SQLITE_OPEN_READONLY         0x00000001  /* Ok for sqlite3_open_v2() */
    00473 #define SQLITE_OPEN_READWRITE        0x00000002  /* Ok for sqlite3_open_v2() */
    00474 #define SQLITE_OPEN_CREATE           0x00000004  /* Ok for sqlite3_open_v2() */
    00475 #define SQLITE_OPEN_DELETEONCLOSE    0x00000008  /* VFS only */
    00476 #define SQLITE_OPEN_EXCLUSIVE        0x00000010  /* VFS only */
    00477 #define SQLITE_OPEN_AUTOPROXY        0x00000020  /* VFS only */
    00478 #define SQLITE_OPEN_URI              0x00000040  /* Ok for sqlite3_open_v2() */
    00479 #define SQLITE_OPEN_MAIN_DB          0x00000100  /* VFS only */
    00480 #define SQLITE_OPEN_TEMP_DB          0x00000200  /* VFS only */
    00481 #define SQLITE_OPEN_TRANSIENT_DB     0x00000400  /* VFS only */
    00482 #define SQLITE_OPEN_MAIN_JOURNAL     0x00000800  /* VFS only */
    00483 #define SQLITE_OPEN_TEMP_JOURNAL     0x00001000  /* VFS only */
    00484 #define SQLITE_OPEN_SUBJOURNAL       0x00002000  /* VFS only */
    00485 #define SQLITE_OPEN_MASTER_JOURNAL   0x00004000  /* VFS only */
    00486 #define SQLITE_OPEN_NOMUTEX          0x00008000  /* Ok for sqlite3_open_v2() */
    00487 #define SQLITE_OPEN_FULLMUTEX        0x00010000  /* Ok for sqlite3_open_v2() */
    00488 #define SQLITE_OPEN_SHAREDCACHE      0x00020000  /* Ok for sqlite3_open_v2() */
    00489 #define SQLITE_OPEN_PRIVATECACHE     0x00040000  /* Ok for sqlite3_open_v2() */
    00490 #define SQLITE_OPEN_WAL              0x00080000  /* VFS only */
    00491
    00492 /* Reserved:                         0x00F00000 */
    00493
    00494 /*
    00495 ** CAPI3REF: Device Characteristics
    00496 **
    00497 ** The xDeviceCharacteristics method of the [sqlite3_io_methods]
    00498 ** object returns an integer which is a vector of the these
    00499 ** bit values expressing I/O characteristics of the mass storage
    00500 ** device that holds the file that the [sqlite3_io_methods]
    00501 ** refers to.
    00502 **
    00503 ** The SQLITE_IOCAP_ATOMIC property means that all writes of
    00504 ** any size are atomic.  The SQLITE_IOCAP_ATOMICnnn values
    00505 ** mean that writes of blocks that are nnn bytes in size and
    00506 ** are aligned to an address which is an integer multiple of
    00507 ** nnn are atomic.  The SQLITE_IOCAP_SAFE_APPEND value means
    00508 ** that when data is appended to a file, the data is appended
    00509 ** first then the size of the file is extended, never the other
    00510 ** way around.  The SQLITE_IOCAP_SEQUENTIAL property means that
    00511 ** information is written to disk in the same order as calls
    00512 ** to xWrite().
    00513 */
    00514 #define SQLITE_IOCAP_ATOMIC                 0x00000001
    00515 #define SQLITE_IOCAP_ATOMIC512              0x00000002
    00516 #define SQLITE_IOCAP_ATOMIC1K               0x00000004
    00517 #define SQLITE_IOCAP_ATOMIC2K               0x00000008
    00518 #define SQLITE_IOCAP_ATOMIC4K               0x00000010
    00519 #define SQLITE_IOCAP_ATOMIC8K               0x00000020
    00520 #define SQLITE_IOCAP_ATOMIC16K              0x00000040
    00521 #define SQLITE_IOCAP_ATOMIC32K              0x00000080
    00522 #define SQLITE_IOCAP_ATOMIC64K              0x00000100
    00523 #define SQLITE_IOCAP_SAFE_APPEND            0x00000200
    00524 #define SQLITE_IOCAP_SEQUENTIAL             0x00000400
    00525 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN  0x00000800
    00526
    00527 /*
    00528 ** CAPI3REF: File Locking Levels
    00529 **
    00530 ** SQLite uses one of these integer values as the second
    00531 ** argument to calls it makes to the xLock() and xUnlock() methods
    00532 ** of an [sqlite3_io_methods] object.
    00533 */
    00534 #define SQLITE_LOCK_NONE          0
    00535 #define SQLITE_LOCK_SHARED        1
    00536 #define SQLITE_LOCK_RESERVED      2
    00537 #define SQLITE_LOCK_PENDING       3
    00538 #define SQLITE_LOCK_EXCLUSIVE     4
    00539
    00540 /*
    00541 ** CAPI3REF: Synchronization Type Flags
    00542 **
    00543 ** When SQLite invokes the xSync() method of an
    00544 ** [sqlite3_io_methods] object it uses a combination of
    00545 ** these integer values as the second argument.
    00546 **
    00547 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
    00548 ** sync operation only needs to flush data to mass storage.  Inode
    00549 ** information need not be flushed. If the lower four bits of the flag
    00550 ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics.
    00551 ** If the lower four bits equal SQLITE_SYNC_FULL, that means
    00552 ** to use Mac OS X style fullsync instead of fsync().
    00553 **
    00554 ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags
    00555 ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL
    00556 ** settings.  The [synchronous pragma] determines when calls to the
    00557 ** xSync VFS method occur and applies uniformly across all platforms.
    00558 ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how
    00559 ** energetic or rigorous or forceful the sync operations are and
    00560 ** only make a difference on Mac OSX for the default SQLite code.
    00561 ** (Third-party VFS implementations might also make the distinction
    00562 ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the
    00563 ** operating systems natively supported by SQLite, only Mac OSX
    00564 ** cares about the difference.)
    00565 */
    00566 #define SQLITE_SYNC_NORMAL        0x00002
    00567 #define SQLITE_SYNC_FULL          0x00003
    00568 #define SQLITE_SYNC_DATAONLY      0x00010
    00569
    00570 /*
    00571 ** CAPI3REF: OS Interface Open File Handle
    00572 **
    00573 ** An [sqlite3_file] object represents an open file in the
    00574 ** [sqlite3_vfs | OS interface layer].  Individual OS interface
    00575 ** implementations will
    00576 ** want to subclass this object by appending additional fields
    00577 ** for their own use.  The pMethods entry is a pointer to an
    00578 ** [sqlite3_io_methods] object that defines methods for performing
    00579 ** I/O operations on the open file.
    00580 */
    00581 typedef struct sqlite3_file sqlite3_file;
    00582 struct sqlite3_file {
    00583   const struct sqlite3_io_methods *pMethods;  /* Methods for an open file */
    00584 };
    00585
    00586 /*
    00587 ** CAPI3REF: OS Interface File Virtual Methods Object
    00588 **
    00589 ** Every file opened by the [sqlite3_vfs.xOpen] method populates an
    00590 ** [sqlite3_file] object (or, more commonly, a subclass of the
    00591 ** [sqlite3_file] object) with a pointer to an instance of this object.
    00592 ** This object defines the methods used to perform various operations
    00593 ** against the open file represented by the [sqlite3_file] object.
    00594 **
    00595 ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element
    00596 ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method
    00597 ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed.  The
    00598 ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen]
    00599 ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element
    00600 ** to NULL.
    00601 **
    00602 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
    00603 ** [SQLITE_SYNC_FULL].  The first choice is the normal fsync().
    00604 ** The second choice is a Mac OS X style fullsync.  The [SQLITE_SYNC_DATAONLY]
    00605 ** flag may be ORed in to indicate that only the data of the file
    00606 ** and not its inode needs to be synced.
    00607 **
    00608 ** The integer values to xLock() and xUnlock() are one of
    00609 ** <ul>
    00610 ** <li> [SQLITE_LOCK_NONE],
    00611 ** <li> [SQLITE_LOCK_SHARED],
    00612 ** <li> [SQLITE_LOCK_RESERVED],
    00613 ** <li> [SQLITE_LOCK_PENDING], or
    00614 ** <li> [SQLITE_LOCK_EXCLUSIVE].
    00615 ** </ul>
    00616 ** xLock() increases the lock. xUnlock() decreases the lock.
    00617 ** The xCheckReservedLock() method checks whether any database connection,
    00618 ** either in this process or in some other process, is holding a RESERVED,
    00619 ** PENDING, or EXCLUSIVE lock on the file.  It returns true
    00620 ** if such a lock exists and false otherwise.
    00621 **
    00622 ** The xFileControl() method is a generic interface that allows custom
    00623 ** VFS implementations to directly control an open file using the
    00624 ** [sqlite3_file_control()] interface.  The second "op" argument is an
    00625 ** integer opcode.  The third argument is a generic pointer intended to
    00626 ** point to a structure that may contain arguments or space in which to
    00627 ** write return values.  Potential uses for xFileControl() might be
    00628 ** functions to enable blocking locks with timeouts, to change the
    00629 ** locking strategy (for example to use dot-file locks), to inquire
    00630 ** about the status of a lock, or to break stale locks.  The SQLite
    00631 ** core reserves all opcodes less than 100 for its own use.
    00632 ** A [SQLITE_FCNTL_LOCKSTATE | list of opcodes] less than 100 is available.
    00633 ** Applications that define a custom xFileControl method should use opcodes
    00634 ** greater than 100 to avoid conflicts.  VFS implementations should
    00635 ** return [SQLITE_NOTFOUND] for file control opcodes that they do not
    00636 ** recognize.
    00637 **
    00638 ** The xSectorSize() method returns the sector size of the
    00639 ** device that underlies the file.  The sector size is the
    00640 ** minimum write that can be performed without disturbing
    00641 ** other bytes in the file.  The xDeviceCharacteristics()
    00642 ** method returns a bit vector describing behaviors of the
    00643 ** underlying device:
    00644 **
    00645 ** <ul>
    00646 ** <li> [SQLITE_IOCAP_ATOMIC]
    00647 ** <li> [SQLITE_IOCAP_ATOMIC512]
    00648 ** <li> [SQLITE_IOCAP_ATOMIC1K]
    00649 ** <li> [SQLITE_IOCAP_ATOMIC2K]
    00650 ** <li> [SQLITE_IOCAP_ATOMIC4K]
    00651 ** <li> [SQLITE_IOCAP_ATOMIC8K]
    00652 ** <li> [SQLITE_IOCAP_ATOMIC16K]
    00653 ** <li> [SQLITE_IOCAP_ATOMIC32K]
    00654 ** <li> [SQLITE_IOCAP_ATOMIC64K]
    00655 ** <li> [SQLITE_IOCAP_SAFE_APPEND]
    00656 ** <li> [SQLITE_IOCAP_SEQUENTIAL]
    00657 ** </ul>
    00658 **
    00659 ** The SQLITE_IOCAP_ATOMIC property means that all writes of
    00660 ** any size are atomic.  The SQLITE_IOCAP_ATOMICnnn values
    00661 ** mean that writes of blocks that are nnn bytes in size and
    00662 ** are aligned to an address which is an integer multiple of
    00663 ** nnn are atomic.  The SQLITE_IOCAP_SAFE_APPEND value means
    00664 ** that when data is appended to a file, the data is appended
    00665 ** first then the size of the file is extended, never the other
    00666 ** way around.  The SQLITE_IOCAP_SEQUENTIAL property means that
    00667 ** information is written to disk in the same order as calls
    00668 ** to xWrite().
    00669 **
    00670 ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill
    00671 ** in the unread portions of the buffer with zeros.  A VFS that
    00672 ** fails to zero-fill short reads might seem to work.  However,
    00673 ** failure to zero-fill short reads will eventually lead to
    00674 ** database corruption.
    00675 */
    00676 typedef struct sqlite3_io_methods sqlite3_io_methods;
    00677 struct sqlite3_io_methods {
    00678   int iVersion;
    00679   int (*xClose)(sqlite3_file*);
    00680   int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
    00681   int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
    00682   int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
    00683   int (*xSync)(sqlite3_file*, int flags);
    00684   int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);
    00685   int (*xLock)(sqlite3_file*, int);
    00686   int (*xUnlock)(sqlite3_file*, int);
    00687   int (*xCheckReservedLock)(sqlite3_file*, int *pResOut);
    00688   int (*xFileControl)(sqlite3_file*, int op, void *pArg);
    00689   int (*xSectorSize)(sqlite3_file*);
    00690   int (*xDeviceCharacteristics)(sqlite3_file*);
    00691   /* Methods above are valid for version 1 */
    00692   int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
    00693   int (*xShmLock)(sqlite3_file*, int offset, int n, int flags);
    00694   void (*xShmBarrier)(sqlite3_file*);
    00695   int (*xShmUnmap)(sqlite3_file*, int deleteFlag);
    00696   /* Methods above are valid for version 2 */
    00697   /* Additional methods may be added in future releases */
    00698 };
    00699
    00700 /*
    00701 ** CAPI3REF: Standard File Control Opcodes
    00702 **
    00703 ** These integer constants are opcodes for the xFileControl method
    00704 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
    00705 ** interface.
    00706 **
    00707 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging.  This
    00708 ** opcode causes the xFileControl method to write the current state of
    00709 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
    00710 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
    00711 ** into an integer that the pArg argument points to. This capability
    00712 ** is used during testing and only needs to be supported when SQLITE_TEST
    00713 ** is defined.
    00714 **
    00715 ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
    00716 ** layer a hint of how large the database file will grow to be during the
    00717 ** current transaction.  This hint is not guaranteed to be accurate but it
    00718 ** is often close.  The underlying VFS might choose to preallocate database
    00719 ** file space based on this hint in order to help writes to the database
    00720 ** file run faster.
    00721 **
    00722 ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
    00723 ** extends and truncates the database file in chunks of a size specified
    00724 ** by the user. The fourth argument to [sqlite3_file_control()] should
    00725 ** point to an integer (type int) containing the new chunk-size to use
    00726 ** for the nominated database. Allocating database file space in large
    00727 ** chunks (say 1MB at a time), may reduce file-system fragmentation and
    00728 ** improve performance on some systems.
    00729 **
    00730 ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
    00731 ** to the [sqlite3_file] object associated with a particular database
    00732 ** connection.  See the [sqlite3_file_control()] documentation for
    00733 ** additional information.
    00734 **
    00735 ** ^(The [SQLITE_FCNTL_SYNC_OMITTED] opcode is generated internally by
    00736 ** SQLite and sent to all VFSes in place of a call to the xSync method
    00737 ** when the database connection has [PRAGMA synchronous] set to OFF.)^
    00738 ** Some specialized VFSes need this signal in order to operate correctly
    00739 ** when [PRAGMA synchronous | PRAGMA synchronous=OFF] is set, but most
    00740 ** VFSes do not need this signal and should silently ignore this opcode.
    00741 ** Applications should not call [sqlite3_file_control()] with this
    00742 ** opcode as doing so may disrupt the operation of the specialized VFSes
    00743 ** that do require it.
    00744 **
    00745 ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic
    00746 ** retry counts and intervals for certain disk I/O operations for the
    00747 ** windows [VFS] in order to work to provide robustness against
    00748 ** anti-virus programs.  By default, the windows VFS will retry file read,
    00749 ** file write, and file delete operations up to 10 times, with a delay
    00750 ** of 25 milliseconds before the first retry and with the delay increasing
    00751 ** by an additional 25 milliseconds with each subsequent retry.  This
    00752 ** opcode allows those to values (10 retries and 25 milliseconds of delay)
    00753 ** to be adjusted.  The values are changed for all database connections
    00754 ** within the same process.  The argument is a pointer to an array of two
    00755 ** integers where the first integer i the new retry count and the second
    00756 ** integer is the delay.  If either integer is negative, then the setting
    00757 ** is not changed but instead the prior value of that setting is written
    00758 ** into the array entry, allowing the current retry settings to be
    00759 ** interrogated.  The zDbName parameter is ignored.
    00760 **
    00761 ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the
    00762 ** persistent [WAL | Write AHead Log] setting.  By default, the auxiliary
    00763 ** write ahead log and shared memory files used for transaction control
    00764 ** are automatically deleted when the latest connection to the database
    00765 ** closes.  Setting persistent WAL mode causes those files to persist after
    00766 ** close.  Persisting the files is useful when other processes that do not
    00767 ** have write permission on the directory containing the database file want
    00768 ** to read the database file, as the WAL and shared memory files must exist
    00769 ** in order for the database to be readable.  The fourth parameter to
    00770 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
    00771 ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent
    00772 ** WAL mode.  If the integer is -1, then it is overwritten with the current
    00773 ** WAL persistence setting.
    00774 **
    00775 ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening
    00776 ** a write transaction to indicate that, unless it is rolled back for some
    00777 ** reason, the entire database file will be overwritten by the current
    00778 ** transaction. This is used by VACUUM operations.
    00779 */
    00780 #define SQLITE_FCNTL_LOCKSTATE        1
    00781 #define SQLITE_GET_LOCKPROXYFILE      2
    00782 #define SQLITE_SET_LOCKPROXYFILE      3
    00783 #define SQLITE_LAST_ERRNO             4
    00784 #define SQLITE_FCNTL_SIZE_HINT        5
    00785 #define SQLITE_FCNTL_CHUNK_SIZE       6
    00786 #define SQLITE_FCNTL_FILE_POINTER     7
    00787 #define SQLITE_FCNTL_SYNC_OMITTED     8
    00788 #define SQLITE_FCNTL_WIN32_AV_RETRY   9
    00789 #define SQLITE_FCNTL_PERSIST_WAL     10
    00790 #define SQLITE_FCNTL_OVERWRITE       11
    00791
    00792 /*
    00793 ** CAPI3REF: Mutex Handle
    00794 **
    00795 ** The mutex module within SQLite defines [sqlite3_mutex] to be an
    00796 ** abstract type for a mutex object.  The SQLite core never looks
    00797 ** at the internal representation of an [sqlite3_mutex].  It only
    00798 ** deals with pointers to the [sqlite3_mutex] object.
    00799 **
    00800 ** Mutexes are created using [sqlite3_mutex_alloc()].
    00801 */
    00802 typedef struct sqlite3_mutex sqlite3_mutex;
    00803
    00804 /*
    00805 ** CAPI3REF: OS Interface Object
    00806 **
    00807 ** An instance of the sqlite3_vfs object defines the interface between
    00808 ** the SQLite core and the underlying operating system.  The "vfs"
    00809 ** in the name of the object stands for "virtual file system".  See
    00810 ** the [VFS | VFS documentation] for further information.
    00811 **
    00812 ** The value of the iVersion field is initially 1 but may be larger in
    00813 ** future versions of SQLite.  Additional fields may be appended to this
    00814 ** object when the iVersion value is increased.  Note that the structure
    00815 ** of the sqlite3_vfs object changes in the transaction between
    00816 ** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not
    00817 ** modified.
    00818 **
    00819 ** The szOsFile field is the size of the subclassed [sqlite3_file]
    00820 ** structure used by this VFS.  mxPathname is the maximum length of
    00821 ** a pathname in this VFS.
    00822 **
    00823 ** Registered sqlite3_vfs objects are kept on a linked list formed by
    00824 ** the pNext pointer.  The [sqlite3_vfs_register()]
    00825 ** and [sqlite3_vfs_unregister()] interfaces manage this list
    00826 ** in a thread-safe way.  The [sqlite3_vfs_find()] interface
    00827 ** searches the list.  Neither the application code nor the VFS
    00828 ** implementation should use the pNext pointer.
    00829 **
    00830 ** The pNext field is the only field in the sqlite3_vfs
    00831 ** structure that SQLite will ever modify.  SQLite will only access
    00832 ** or modify this field while holding a particular static mutex.
    00833 ** The application should never modify anything within the sqlite3_vfs
    00834 ** object once the object has been registered.
    00835 **
    00836 ** The zName field holds the name of the VFS module.  The name must
    00837 ** be unique across all VFS modules.
    00838 **
    00839 ** [[sqlite3_vfs.xOpen]]
    00840 ** ^SQLite guarantees that the zFilename parameter to xOpen
    00841 ** is either a NULL pointer or string obtained
    00842 ** from xFullPathname() with an optional suffix added.
    00843 ** ^If a suffix is added to the zFilename parameter, it will
    00844 ** consist of a single "-" character followed by no more than
    00845 ** 10 alphanumeric and/or "-" characters.
    00846 ** ^SQLite further guarantees that
    00847 ** the string will be valid and unchanged until xClose() is
    00848 ** called. Because of the previous sentence,
    00849 ** the [sqlite3_file] can safely store a pointer to the
    00850 ** filename if it needs to remember the filename for some reason.
    00851 ** If the zFilename parameter to xOpen is a NULL pointer then xOpen
    00852 ** must invent its own temporary name for the file.  ^Whenever the
    00853 ** xFilename parameter is NULL it will also be the case that the
    00854 ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
    00855 **
    00856 ** The flags argument to xOpen() includes all bits set in
    00857 ** the flags argument to [sqlite3_open_v2()].  Or if [sqlite3_open()]
    00858 ** or [sqlite3_open16()] is used, then flags includes at least
    00859 ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE].
    00860 ** If xOpen() opens a file read-only then it sets *pOutFlags to
    00861 ** include [SQLITE_OPEN_READONLY].  Other bits in *pOutFlags may be set.
    00862 **
    00863 ** ^(SQLite will also add one of the following flags to the xOpen()
    00864 ** call, depending on the object being opened:
    00865 **
    00866 ** <ul>
    00867 ** <li>  [SQLITE_OPEN_MAIN_DB]
    00868 ** <li>  [SQLITE_OPEN_MAIN_JOURNAL]
    00869 ** <li>  [SQLITE_OPEN_TEMP_DB]
    00870 ** <li>  [SQLITE_OPEN_TEMP_JOURNAL]
    00871 ** <li>  [SQLITE_OPEN_TRANSIENT_DB]
    00872 ** <li>  [SQLITE_OPEN_SUBJOURNAL]
    00873 ** <li>  [SQLITE_OPEN_MASTER_JOURNAL]
    00874 ** <li>  [SQLITE_OPEN_WAL]
    00875 ** </ul>)^
    00876 **
    00877 ** The file I/O implementation can use the object type flags to
    00878 ** change the way it deals with files.  For example, an application
    00879 ** that does not care about crash recovery or rollback might make
    00880 ** the open of a journal file a no-op.  Writes to this journal would
    00881 ** also be no-ops, and any attempt to read the journal would return
    00882 ** SQLITE_IOERR.  Or the implementation might recognize that a database
    00883 ** file will be doing page-aligned sector reads and writes in a random
    00884 ** order and set up its I/O subsystem accordingly.
    00885 **
    00886 ** SQLite might also add one of the following flags to the xOpen method:
    00887 **
    00888 ** <ul>
    00889 ** <li> [SQLITE_OPEN_DELETEONCLOSE]
    00890 ** <li> [SQLITE_OPEN_EXCLUSIVE]
    00891 ** </ul>
    00892 **
    00893 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
    00894 ** deleted when it is closed.  ^The [SQLITE_OPEN_DELETEONCLOSE]
    00895 ** will be set for TEMP databases and their journals, transient
    00896 ** databases, and subjournals.
    00897 **
    00898 ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction
    00899 ** with the [SQLITE_OPEN_CREATE] flag, which are both directly
    00900 ** analogous to the O_EXCL and O_CREAT flags of the POSIX open()
    00901 ** API.  The SQLITE_OPEN_EXCLUSIVE flag, when paired with the
    00902 ** SQLITE_OPEN_CREATE, is used to indicate that file should always
    00903 ** be created, and that it is an error if it already exists.
    00904 ** It is <i>not</i> used to indicate the file should be opened
    00905 ** for exclusive access.
    00906 **
    00907 ** ^At least szOsFile bytes of memory are allocated by SQLite
    00908 ** to hold the  [sqlite3_file] structure passed as the third
    00909 ** argument to xOpen.  The xOpen method does not have to
    00910 ** allocate the structure; it should just fill it in.  Note that
    00911 ** the xOpen method must set the sqlite3_file.pMethods to either
    00912 ** a valid [sqlite3_io_methods] object or to NULL.  xOpen must do
    00913 ** this even if the open fails.  SQLite expects that the sqlite3_file.pMethods
    00914 ** element will be valid after xOpen returns regardless of the success
    00915 ** or failure of the xOpen call.
    00916 **
    00917 ** [[sqlite3_vfs.xAccess]]
    00918 ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
    00919 ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
    00920 ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
    00921 ** to test whether a file is at least readable.   The file can be a
    00922 ** directory.
    00923 **
    00924 ** ^SQLite will always allocate at least mxPathname+1 bytes for the
    00925 ** output buffer xFullPathname.  The exact size of the output buffer
    00926 ** is also passed as a parameter to both  methods. If the output buffer
    00927 ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
    00928 ** handled as a fatal error by SQLite, vfs implementations should endeavor
    00929 ** to prevent this by setting mxPathname to a sufficiently large value.
    00930 **
    00931 ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64()
    00932 ** interfaces are not strictly a part of the filesystem, but they are
    00933 ** included in the VFS structure for completeness.
    00934 ** The xRandomness() function attempts to return nBytes bytes
    00935 ** of good-quality randomness into zOut.  The return value is
    00936 ** the actual number of bytes of randomness obtained.
    00937 ** The xSleep() method causes the calling thread to sleep for at
    00938 ** least the number of microseconds given.  ^The xCurrentTime()
    00939 ** method returns a Julian Day Number for the current date and time as
    00940 ** a floating point value.
    00941 ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian
    00942 ** Day Number multiplied by 86400000 (the number of milliseconds in
    00943 ** a 24-hour day).
    00944 ** ^SQLite will use the xCurrentTimeInt64() method to get the current
    00945 ** date and time if that method is available (if iVersion is 2 or
    00946 ** greater and the function pointer is not NULL) and will fall back
    00947 ** to xCurrentTime() if xCurrentTimeInt64() is unavailable.
    00948 **
    00949 ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces
    00950 ** are not used by the SQLite core.  These optional interfaces are provided
    00951 ** by some VFSes to facilitate testing of the VFS code. By overriding
    00952 ** system calls with functions under its control, a test program can
    00953 ** simulate faults and error conditions that would otherwise be difficult
    00954 ** or impossible to induce.  The set of system calls that can be overridden
    00955 ** varies from one VFS to another, and from one version of the same VFS to the
    00956 ** next.  Applications that use these interfaces must be prepared for any
    00957 ** or all of these interfaces to be NULL or for their behavior to change
    00958 ** from one release to the next.  Applications must not attempt to access
    00959 ** any of these methods if the iVersion of the VFS is less than 3.
    00960 */
    00961 typedef struct sqlite3_vfs sqlite3_vfs;
    00962 typedef void (*sqlite3_syscall_ptr)(void);
    00963 struct sqlite3_vfs {
    00964   int iVersion;            /* Structure version number (currently 3) */
    00965   int szOsFile;            /* Size of subclassed sqlite3_file */
    00966   int mxPathname;          /* Maximum file pathname length */
    00967   sqlite3_vfs *pNext;      /* Next registered VFS */
    00968   const char *zName;       /* Name of this virtual file system */
    00969   void *pAppData;          /* Pointer to application-specific data */
    00970   int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*,
    00971                int flags, int *pOutFlags);
    00972   int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);
    00973   int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);
    00974   int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);
    00975   void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);
    00976   void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
    00977   void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);
    00978   void (*xDlClose)(sqlite3_vfs*, void*);
    00979   int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
    00980   int (*xSleep)(sqlite3_vfs*, int microseconds);
    00981   int (*xCurrentTime)(sqlite3_vfs*, double*);
    00982   int (*xGetLastError)(sqlite3_vfs*, int, char *);
    00983   /*
    00984   ** The methods above are in version 1 of the sqlite_vfs object
    00985   ** definition.  Those that follow are added in version 2 or later
    00986   */
    00987   int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);
    00988   /*
    00989   ** The methods above are in versions 1 and 2 of the sqlite_vfs object.
    00990   ** Those below are for version 3 and greater.
    00991   */
    00992   int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr);
    00993   sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName);
    00994   const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName);
    00995   /*
    00996   ** The methods above are in versions 1 through 3 of the sqlite_vfs object.
    00997   ** New fields may be appended in figure versions.  The iVersion
    00998   ** value will increment whenever this happens.
    00999   */
    01000 };
    01001
    01002 /*
    01003 ** CAPI3REF: Flags for the xAccess VFS method
    01004 **
    01005 ** These integer constants can be used as the third parameter to
    01006 ** the xAccess method of an [sqlite3_vfs] object.  They determine
    01007 ** what kind of permissions the xAccess method is looking for.
    01008 ** With SQLITE_ACCESS_EXISTS, the xAccess method
    01009 ** simply checks whether the file exists.
    01010 ** With SQLITE_ACCESS_READWRITE, the xAccess method
    01011 ** checks whether the named directory is both readable and writable
    01012 ** (in other words, if files can be added, removed, and renamed within
    01013 ** the directory).
    01014 ** The SQLITE_ACCESS_READWRITE constant is currently used only by the
    01015 ** [temp_store_directory pragma], though this could change in a future
    01016 ** release of SQLite.
    01017 ** With SQLITE_ACCESS_READ, the xAccess method
    01018 ** checks whether the file is readable.  The SQLITE_ACCESS_READ constant is
    01019 ** currently unused, though it might be used in a future release of
    01020 ** SQLite.
    01021 */
    01022 #define SQLITE_ACCESS_EXISTS    0
    01023 #define SQLITE_ACCESS_READWRITE 1   /* Used by PRAGMA temp_store_directory */
    01024 #define SQLITE_ACCESS_READ      2   /* Unused */
    01025
    01026 /*
    01027 ** CAPI3REF: Flags for the xShmLock VFS method
    01028 **
    01029 ** These integer constants define the various locking operations
    01030 ** allowed by the xShmLock method of [sqlite3_io_methods].  The
    01031 ** following are the only legal combinations of flags to the
    01032 ** xShmLock method:
    01033 **
    01034 ** <ul>
    01035 ** <li>  SQLITE_SHM_LOCK | SQLITE_SHM_SHARED
    01036 ** <li>  SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE
    01037 ** <li>  SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED
    01038 ** <li>  SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE
    01039 ** </ul>
    01040 **
    01041 ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
    01042 ** was given no the corresponding lock.
    01043 **
    01044 ** The xShmLock method can transition between unlocked and SHARED or
    01045 ** between unlocked and EXCLUSIVE.  It cannot transition between SHARED
    01046 ** and EXCLUSIVE.
    01047 */
    01048 #define SQLITE_SHM_UNLOCK       1
    01049 #define SQLITE_SHM_LOCK         2
    01050 #define SQLITE_SHM_SHARED       4
    01051 #define SQLITE_SHM_EXCLUSIVE    8
    01052
    01053 /*
    01054 ** CAPI3REF: Maximum xShmLock index
    01055 **
    01056 ** The xShmLock method on [sqlite3_io_methods] may use values
    01057 ** between 0 and this upper bound as its "offset" argument.
    01058 ** The SQLite core will never attempt to acquire or release a
    01059 ** lock outside of this range
    01060 */
    01061 #define SQLITE_SHM_NLOCK        8
    01062
    01063
    01064 /*
    01065 ** CAPI3REF: Initialize The SQLite Library
    01066 **
    01067 ** ^The sqlite3_initialize() routine initializes the
    01068 ** SQLite library.  ^The sqlite3_shutdown() routine
    01069 ** deallocates any resources that were allocated by sqlite3_initialize().
    01070 ** These routines are designed to aid in process initialization and
    01071 ** shutdown on embedded systems.  Workstation applications using
    01072 ** SQLite normally do not need to invoke either of these routines.
    01073 **
    01074 ** A call to sqlite3_initialize() is an "effective" call if it is
    01075 ** the first time sqlite3_initialize() is invoked during the lifetime of
    01076 ** the process, or if it is the first time sqlite3_initialize() is invoked
    01077 ** following a call to sqlite3_shutdown().  ^(Only an effective call
    01078 ** of sqlite3_initialize() does any initialization.  All other calls
    01079 ** are harmless no-ops.)^
    01080 **
    01081 ** A call to sqlite3_shutdown() is an "effective" call if it is the first
    01082 ** call to sqlite3_shutdown() since the last sqlite3_initialize().  ^(Only
    01083 ** an effective call to sqlite3_shutdown() does any deinitialization.
    01084 ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
    01085 **
    01086 ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
    01087 ** is not.  The sqlite3_shutdown() interface must only be called from a
    01088 ** single thread.  All open [database connections] must be closed and all
    01089 ** other SQLite resources must be deallocated prior to invoking
    01090 ** sqlite3_shutdown().
    01091 **
    01092 ** Among other things, ^sqlite3_initialize() will invoke
    01093 ** sqlite3_os_init().  Similarly, ^sqlite3_shutdown()
    01094 ** will invoke sqlite3_os_end().
    01095 **
    01096 ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
    01097 ** ^If for some reason, sqlite3_initialize() is unable to initialize
    01098 ** the library (perhaps it is unable to allocate a needed resource such
    01099 ** as a mutex) it returns an [error code] other than [SQLITE_OK].
    01100 **
    01101 ** ^The sqlite3_initialize() routine is called internally by many other
    01102 ** SQLite interfaces so that an application usually does not need to
    01103 ** invoke sqlite3_initialize() directly.  For example, [sqlite3_open()]
    01104 ** calls sqlite3_initialize() so the SQLite library will be automatically
    01105 ** initialized when [sqlite3_open()] is called if it has not be initialized
    01106 ** already.  ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
    01107 ** compile-time option, then the automatic calls to sqlite3_initialize()
    01108 ** are omitted and the application must call sqlite3_initialize() directly
    01109 ** prior to using any other SQLite interface.  For maximum portability,
    01110 ** it is recommended that applications always invoke sqlite3_initialize()
    01111 ** directly prior to using any other SQLite interface.  Future releases
    01112 ** of SQLite may require this.  In other words, the behavior exhibited
    01113 ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
    01114 ** default behavior in some future release of SQLite.
    01115 **
    01116 ** The sqlite3_os_init() routine does operating-system specific
    01117 ** initialization of the SQLite library.  The sqlite3_os_end()
    01118 ** routine undoes the effect of sqlite3_os_init().  Typical tasks
    01119 ** performed by these routines include allocation or deallocation
    01120 ** of static resources, initialization of global variables,
    01121 ** setting up a default [sqlite3_vfs] module, or setting up
    01122 ** a default configuration using [sqlite3_config()].
    01123 **
    01124 ** The application should never invoke either sqlite3_os_init()
    01125 ** or sqlite3_os_end() directly.  The application should only invoke
    01126 ** sqlite3_initialize() and sqlite3_shutdown().  The sqlite3_os_init()
    01127 ** interface is called automatically by sqlite3_initialize() and
    01128 ** sqlite3_os_end() is called by sqlite3_shutdown().  Appropriate
    01129 ** implementations for sqlite3_os_init() and sqlite3_os_end()
    01130 ** are built into SQLite when it is compiled for Unix, Windows, or OS/2.
    01131 ** When [custom builds | built for other platforms]
    01132 ** (using the [SQLITE_OS_OTHER=1] compile-time
    01133 ** option) the application must supply a suitable implementation for
    01134 ** sqlite3_os_init() and sqlite3_os_end().  An application-supplied
    01135 ** implementation of sqlite3_os_init() or sqlite3_os_end()
    01136 ** must return [SQLITE_OK] on success and some other [error code] upon
    01137 ** failure.
    01138 */
    01139 SQLITE_API int sqlite3_initialize(void);
    01140 SQLITE_API int sqlite3_shutdown(void);
    01141 SQLITE_API int sqlite3_os_init(void);
    01142 SQLITE_API int sqlite3_os_end(void);
    01143
    01144 /*
    01145 ** CAPI3REF: Configuring The SQLite Library
    01146 **
    01147 ** The sqlite3_config() interface is used to make global configuration
    01148 ** changes to SQLite in order to tune SQLite to the specific needs of
    01149 ** the application.  The default configuration is recommended for most
    01150 ** applications and so this routine is usually not necessary.  It is
    01151 ** provided to support rare applications with unusual needs.
    01152 **
    01153 ** The sqlite3_config() interface is not threadsafe.  The application
    01154 ** must insure that no other SQLite interfaces are invoked by other
    01155 ** threads while sqlite3_config() is running.  Furthermore, sqlite3_config()
    01156 ** may only be invoked prior to library initialization using
    01157 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
    01158 ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
    01159 ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE.
    01160 ** Note, however, that ^sqlite3_config() can be called as part of the
    01161 ** implementation of an application-defined [sqlite3_os_init()].
    01162 **
    01163 ** The first argument to sqlite3_config() is an integer
    01164 ** [configuration option] that determines
    01165 ** what property of SQLite is to be configured.  Subsequent arguments
    01166 ** vary depending on the [configuration option]
    01167 ** in the first argument.
    01168 **
    01169 ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
    01170 ** ^If the option is unknown or SQLite is unable to set the option
    01171 ** then this routine returns a non-zero [error code].
    01172 */
    01173 SQLITE_API int sqlite3_config(int, ...);
    01174
    01175 /*
    01176 ** CAPI3REF: Configure database connections
    01177 **
    01178 ** The sqlite3_db_config() interface is used to make configuration
    01179 ** changes to a [database connection].  The interface is similar to
    01180 ** [sqlite3_config()] except that the changes apply to a single
    01181 ** [database connection] (specified in the first argument).
    01182 **
    01183 ** The second argument to sqlite3_db_config(D,V,...)  is the
    01184 ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code
    01185 ** that indicates what aspect of the [database connection] is being configured.
    01186 ** Subsequent arguments vary depending on the configuration verb.
    01187 **
    01188 ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
    01189 ** the call is considered successful.
    01190 */
    01191 SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...);
    01192
    01193 /*
    01194 ** CAPI3REF: Memory Allocation Routines
    01195 **
    01196 ** An instance of this object defines the interface between SQLite
    01197 ** and low-level memory allocation routines.
    01198 **
    01199 ** This object is used in only one place in the SQLite interface.
    01200 ** A pointer to an instance of this object is the argument to
    01201 ** [sqlite3_config()] when the configuration option is
    01202 ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC].
    01203 ** By creating an instance of this object
    01204 ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])
    01205 ** during configuration, an application can specify an alternative
    01206 ** memory allocation subsystem for SQLite to use for all of its
    01207 ** dynamic memory needs.
    01208 **
    01209 ** Note that SQLite comes with several [built-in memory allocators]
    01210 ** that are perfectly adequate for the overwhelming majority of applications
    01211 ** and that this object is only useful to a tiny minority of applications
    01212 ** with specialized memory allocation requirements.  This object is
    01213 ** also used during testing of SQLite in order to specify an alternative
    01214 ** memory allocator that simulates memory out-of-memory conditions in
    01215 ** order to verify that SQLite recovers gracefully from such
    01216 ** conditions.
    01217 **
    01218 ** The xMalloc, xRealloc, and xFree methods must work like the
    01219 ** malloc(), realloc() and free() functions from the standard C library.
    01220 ** ^SQLite guarantees that the second argument to
    01221 ** xRealloc is always a value returned by a prior call to xRoundup.
    01222 **
    01223 ** xSize should return the allocated size of a memory allocation
    01224 ** previously obtained from xMalloc or xRealloc.  The allocated size
    01225 ** is always at least as big as the requested size but may be larger.
    01226 **
    01227 ** The xRoundup method returns what would be the allocated size of
    01228 ** a memory allocation given a particular requested size.  Most memory
    01229 ** allocators round up memory allocations at least to the next multiple
    01230 ** of 8.  Some allocators round up to a larger multiple or to a power of 2.
    01231 ** Every memory allocation request coming in through [sqlite3_malloc()]
    01232 ** or [sqlite3_realloc()] first calls xRoundup.  If xRoundup returns 0,
    01233 ** that causes the corresponding memory allocation to fail.
    01234 **
    01235 ** The xInit method initializes the memory allocator.  (For example,
    01236 ** it might allocate any require mutexes or initialize internal data
    01237 ** structures.  The xShutdown method is invoked (indirectly) by
    01238 ** [sqlite3_shutdown()] and should deallocate any resources acquired
    01239 ** by xInit.  The pAppData pointer is used as the only parameter to
    01240 ** xInit and xShutdown.
    01241 **
    01242 ** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes
    01243 ** the xInit method, so the xInit method need not be threadsafe.  The
    01244 ** xShutdown method is only called from [sqlite3_shutdown()] so it does
    01245 ** not need to be threadsafe either.  For all other methods, SQLite
    01246 ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
    01247 ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
    01248 ** it is by default) and so the methods are automatically serialized.
    01249 ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other
    01250 ** methods must be threadsafe or else make their own arrangements for
    01251 ** serialization.
    01252 **
    01253 ** SQLite will never invoke xInit() more than once without an intervening
    01254 ** call to xShutdown().
    01255 */
    01256 typedef struct sqlite3_mem_methods sqlite3_mem_methods;
    01257 struct sqlite3_mem_methods {
    01258   void *(*xMalloc)(int);         /* Memory allocation function */
    01259   void (*xFree)(void*);          /* Free a prior allocation */
    01260   void *(*xRealloc)(void*,int);  /* Resize an allocation */
    01261   int (*xSize)(void*);           /* Return the size of an allocation */
    01262   int (*xRoundup)(int);          /* Round up request size to allocation size */
    01263   int (*xInit)(void*);           /* Initialize the memory allocator */
    01264   void (*xShutdown)(void*);      /* Deinitialize the memory allocator */
    01265   void *pAppData;                /* Argument to xInit() and xShutdown() */
    01266 };
    01267
    01268 /*
    01269 ** CAPI3REF: Configuration Options
    01270 ** KEYWORDS: {configuration option}
    01271 **
    01272 ** These constants are the available integer configuration options that
    01273 ** can be passed as the first argument to the [sqlite3_config()] interface.
    01274 **
    01275 ** New configuration options may be added in future releases of SQLite.
    01276 ** Existing configuration options might be discontinued.  Applications
    01277 ** should check the return code from [sqlite3_config()] to make sure that
    01278 ** the call worked.  The [sqlite3_config()] interface will return a
    01279 ** non-zero [error code] if a discontinued or unsupported configuration option
    01280 ** is invoked.
    01281 **
    01282 ** <dl>
    01283 ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
    01284 ** <dd>There are no arguments to this option.  ^This option sets the
    01285 ** [threading mode] to Single-thread.  In other words, it disables
    01286 ** all mutexing and puts SQLite into a mode where it can only be used
    01287 ** by a single thread.   ^If SQLite is compiled with
    01288 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
    01289 ** it is not possible to change the [threading mode] from its default
    01290 ** value of Single-thread and so [sqlite3_config()] will return
    01291 ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD
    01292 ** configuration option.</dd>
    01293 **
    01294 ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt>
    01295 ** <dd>There are no arguments to this option.  ^This option sets the
    01296 ** [threading mode] to Multi-thread.  In other words, it disables
    01297 ** mutexing on [database connection] and [prepared statement] objects.
    01298 ** The application is responsible for serializing access to
    01299 ** [database connections] and [prepared statements].  But other mutexes
    01300 ** are enabled so that SQLite will be safe to use in a multi-threaded
    01301 ** environment as long as no two threads attempt to use the same
    01302 ** [database connection] at the same time.  ^If SQLite is compiled with
    01303 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
    01304 ** it is not possible to set the Multi-thread [threading mode] and
    01305 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
    01306 ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
    01307 **
    01308 ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt>
    01309 ** <dd>There are no arguments to this option.  ^This option sets the
    01310 ** [threading mode] to Serialized. In other words, this option enables
    01311 ** all mutexes including the recursive
    01312 ** mutexes on [database connection] and [prepared statement] objects.
    01313 ** In this mode (which is the default when SQLite is compiled with
    01314 ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
    01315 ** to [database connections] and [prepared statements] so that the
    01316 ** application is free to use the same [database connection] or the
    01317 ** same [prepared statement] in different threads at the same time.
    01318 ** ^If SQLite is compiled with
    01319 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
    01320 ** it is not possible to set the Serialized [threading mode] and
    01321 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
    01322 ** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
    01323 **
    01324 ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>
    01325 ** <dd> ^(This option takes a single argument which is a pointer to an
    01326 ** instance of the [sqlite3_mem_methods] structure.  The argument specifies
    01327 ** alternative low-level memory allocation routines to be used in place of
    01328 ** the memory allocation routines built into SQLite.)^ ^SQLite makes
    01329 ** its own private copy of the content of the [sqlite3_mem_methods] structure
    01330 ** before the [sqlite3_config()] call returns.</dd>
    01331 **
    01332 ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>
    01333 ** <dd> ^(This option takes a single argument which is a pointer to an
    01334 ** instance of the [sqlite3_mem_methods] structure.  The [sqlite3_mem_methods]
    01335 ** structure is filled with the currently defined memory allocation routines.)^
    01336 ** This option can be used to overload the default memory allocation
    01337 ** routines with a wrapper that simulations memory allocation failure or
    01338 ** tracks memory usage, for example. </dd>
    01339 **
    01340 ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
    01341 ** <dd> ^This option takes single argument of type int, interpreted as a
    01342 ** boolean, which enables or disables the collection of memory allocation
    01343 ** statistics. ^(When memory allocation statistics are disabled, the
    01344 ** following SQLite interfaces become non-operational:
    01345 **   <ul>
    01346 **   <li> [sqlite3_memory_used()]
    01347 **   <li> [sqlite3_memory_highwater()]
    01348 **   <li> [sqlite3_soft_heap_limit64()]
    01349 **   <li> [sqlite3_status()]
    01350 **   </ul>)^
    01351 ** ^Memory allocation statistics are enabled by default unless SQLite is
    01352 ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
    01353 ** allocation statistics are disabled by default.
    01354 ** </dd>
    01355 **
    01356 ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>
    01357 ** <dd> ^This option specifies a static memory buffer that SQLite can use for
    01358 ** scratch memory.  There are three arguments:  A pointer an 8-byte
    01359 ** aligned memory buffer from which the scratch allocations will be
    01360 ** drawn, the size of each scratch allocation (sz),
    01361 ** and the maximum number of scratch allocations (N).  The sz
    01362 ** argument must be a multiple of 16.
    01363 ** The first argument must be a pointer to an 8-byte aligned buffer
    01364 ** of at least sz*N bytes of memory.
    01365 ** ^SQLite will use no more than two scratch buffers per thread.  So
    01366 ** N should be set to twice the expected maximum number of threads.
    01367 ** ^SQLite will never require a scratch buffer that is more than 6
    01368 ** times the database page size. ^If SQLite needs needs additional
    01369 ** scratch memory beyond what is provided by this configuration option, then
    01370 ** [sqlite3_malloc()] will be used to obtain the memory needed.</dd>
    01371 **
    01372 ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
    01373 ** <dd> ^This option specifies a static memory buffer that SQLite can use for
    01374 ** the database page cache with the default page cache implementation.
    01375 ** This configuration should not be used if an application-define page
    01376 ** cache implementation is loaded using the SQLITE_CONFIG_PCACHE option.
    01377 ** There are three arguments to this option: A pointer to 8-byte aligned
    01378 ** memory, the size of each page buffer (sz), and the number of pages (N).
    01379 ** The sz argument should be the size of the largest database page
    01380 ** (a power of two between 512 and 32768) plus a little extra for each
    01381 ** page header.  ^The page header size is 20 to 40 bytes depending on
    01382 ** the host architecture.  ^It is harmless, apart from the wasted memory,
    01383 ** to make sz a little too large.  The first
    01384 ** argument should point to an allocation of at least sz*N bytes of memory.
    01385 ** ^SQLite will use the memory provided by the first argument to satisfy its
    01386 ** memory needs for the first N pages that it adds to cache.  ^If additional
    01387 ** page cache memory is needed beyond what is provided by this option, then
    01388 ** SQLite goes to [sqlite3_malloc()] for the additional storage space.
    01389 ** The pointer in the first argument must
    01390 ** be aligned to an 8-byte boundary or subsequent behavior of SQLite
    01391 ** will be undefined.</dd>
    01392 **
    01393 ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
    01394 ** <dd> ^This option specifies a static memory buffer that SQLite will use
    01395 ** for all of its dynamic memory allocation needs beyond those provided
    01396 ** for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE].
    01397 ** There are three arguments: An 8-byte aligned pointer to the memory,
    01398 ** the number of bytes in the memory buffer, and the minimum allocation size.
    01399 ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
    01400 ** to using its default memory allocator (the system malloc() implementation),
    01401 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC].  ^If the
    01402 ** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or
    01403 ** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory
    01404 ** allocator is engaged to handle all of SQLites memory allocation needs.
    01405 ** The first pointer (the memory pointer) must be aligned to an 8-byte
    01406 ** boundary or subsequent behavior of SQLite will be undefined.
    01407 ** The minimum allocation size is capped at 2**12. Reasonable values
    01408 ** for the minimum allocation size are 2**5 through 2**8.</dd>
    01409 **
    01410 ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
    01411 ** <dd> ^(This option takes a single argument which is a pointer to an
    01412 ** instance of the [sqlite3_mutex_methods] structure.  The argument specifies
    01413 ** alternative low-level mutex routines to be used in place
    01414 ** the mutex routines built into SQLite.)^  ^SQLite makes a copy of the
    01415 ** content of the [sqlite3_mutex_methods] structure before the call to
    01416 ** [sqlite3_config()] returns. ^If SQLite is compiled with
    01417 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
    01418 ** the entire mutexing subsystem is omitted from the build and hence calls to
    01419 ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
    01420 ** return [SQLITE_ERROR].</dd>
    01421 **
    01422 ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>
    01423 ** <dd> ^(This option takes a single argument which is a pointer to an
    01424 ** instance of the [sqlite3_mutex_methods] structure.  The
    01425 ** [sqlite3_mutex_methods]
    01426 ** structure is filled with the currently defined mutex routines.)^
    01427 ** This option can be used to overload the default mutex allocation
    01428 ** routines with a wrapper used to track mutex usage for performance
    01429 ** profiling or testing, for example.   ^If SQLite is compiled with
    01430 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
    01431 ** the entire mutexing subsystem is omitted from the build and hence calls to
    01432 ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
    01433 ** return [SQLITE_ERROR].</dd>
    01434 **
    01435 ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>
    01436 ** <dd> ^(This option takes two arguments that determine the default
    01437 ** memory allocation for the lookaside memory allocator on each
    01438 ** [database connection].  The first argument is the
    01439 ** size of each lookaside buffer slot and the second is the number of
    01440 ** slots allocated to each database connection.)^  ^(This option sets the
    01441 ** <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE]
    01442 ** verb to [sqlite3_db_config()] can be used to change the lookaside
    01443 ** configuration on individual connections.)^ </dd>
    01444 **
    01445 ** [[SQLITE_CONFIG_PCACHE]] <dt>SQLITE_CONFIG_PCACHE</dt>
    01446 ** <dd> ^(This option takes a single argument which is a pointer to
    01447 ** an [sqlite3_pcache_methods] object.  This object specifies the interface
    01448 ** to a custom page cache implementation.)^  ^SQLite makes a copy of the
    01449 ** object and uses it for page cache memory allocations.</dd>
    01450 **
    01451 ** [[SQLITE_CONFIG_GETPCACHE]] <dt>SQLITE_CONFIG_GETPCACHE</dt>
    01452 ** <dd> ^(This option takes a single argument which is a pointer to an
    01453 ** [sqlite3_pcache_methods] object.  SQLite copies of the current
    01454 ** page cache implementation into that object.)^ </dd>
    01455 **
    01456 ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
    01457 ** <dd> ^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
    01458 ** function with a call signature of void(*)(void*,int,const char*),
    01459 ** and a pointer to void. ^If the function pointer is not NULL, it is
    01460 ** invoked by [sqlite3_log()] to process each logging event.  ^If the
    01461 ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.
    01462 ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is
    01463 ** passed through as the first parameter to the application-defined logger
    01464 ** function whenever that function is invoked.  ^The second parameter to
    01465 ** the logger function is a copy of the first parameter to the corresponding
    01466 ** [sqlite3_log()] call and is intended to be a [result code] or an
    01467 ** [extended result code].  ^The third parameter passed to the logger is
    01468 ** log message after formatting via [sqlite3_snprintf()].
    01469 ** The SQLite logging interface is not reentrant; the logger function
    01470 ** supplied by the application must not invoke any SQLite interface.
    01471 ** In a multi-threaded application, the application-defined logger
    01472 ** function must be threadsafe. </dd>
    01473 **
    01474 ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
    01475 ** <dd> This option takes a single argument of type int. If non-zero, then
    01476 ** URI handling is globally enabled. If the parameter is zero, then URI handling
    01477 ** is globally disabled. If URI handling is globally enabled, all filenames
    01478 ** passed to [sqlite3_open()], [sqlite3_open_v2()], [sqlite3_open16()] or
    01479 ** specified as part of [ATTACH] commands are interpreted as URIs, regardless
    01480 ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
    01481 ** connection is opened. If it is globally disabled, filenames are
    01482 ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
    01483 ** database connection is opened. By default, URI handling is globally
    01484 ** disabled. The default value may be changed by compiling with the
    01485 ** [SQLITE_USE_URI] symbol defined.
    01486 ** </dl>
    01487 */
    01488 #define SQLITE_CONFIG_SINGLETHREAD  1  /* nil */
    01489 #define SQLITE_CONFIG_MULTITHREAD   2  /* nil */
    01490 #define SQLITE_CONFIG_SERIALIZED    3  /* nil */
    01491 #define SQLITE_CONFIG_MALLOC        4  /* sqlite3_mem_methods* */
    01492 #define SQLITE_CONFIG_GETMALLOC     5  /* sqlite3_mem_methods* */
    01493 #define SQLITE_CONFIG_SCRATCH       6  /* void*, int sz, int N */
    01494 #define SQLITE_CONFIG_PAGECACHE     7  /* void*, int sz, int N */
    01495 #define SQLITE_CONFIG_HEAP          8  /* void*, int nByte, int min */
    01496 #define SQLITE_CONFIG_MEMSTATUS     9  /* boolean */
    01497 #define SQLITE_CONFIG_MUTEX        10  /* sqlite3_mutex_methods* */
    01498 #define SQLITE_CONFIG_GETMUTEX     11  /* sqlite3_mutex_methods* */
    01499 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */
    01500 #define SQLITE_CONFIG_LOOKASIDE    13  /* int int */
    01501 #define SQLITE_CONFIG_PCACHE       14  /* sqlite3_pcache_methods* */
    01502 #define SQLITE_CONFIG_GETPCACHE    15  /* sqlite3_pcache_methods* */
    01503 #define SQLITE_CONFIG_LOG          16  /* xFunc, void* */
    01504 #define SQLITE_CONFIG_URI          17  /* int */
    01505
    01506 /*
    01507 ** CAPI3REF: Database Connection Configuration Options
    01508 **
    01509 ** These constants are the available integer configuration options that
    01510 ** can be passed as the second argument to the [sqlite3_db_config()] interface.
    01511 **
    01512 ** New configuration options may be added in future releases of SQLite.
    01513 ** Existing configuration options might be discontinued.  Applications
    01514 ** should check the return code from [sqlite3_db_config()] to make sure that
    01515 ** the call worked.  ^The [sqlite3_db_config()] interface will return a
    01516 ** non-zero [error code] if a discontinued or unsupported configuration option
    01517 ** is invoked.
    01518 **
    01519 ** <dl>
    01520 ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
    01521 ** <dd> ^This option takes three additional arguments that determine the
    01522 ** [lookaside memory allocator] configuration for the [database connection].
    01523 ** ^The first argument (the third parameter to [sqlite3_db_config()] is a
    01524 ** pointer to a memory buffer to use for lookaside memory.
    01525 ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb
    01526 ** may be NULL in which case SQLite will allocate the
    01527 ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the
    01528 ** size of each lookaside buffer slot.  ^The third argument is the number of
    01529 ** slots.  The size of the buffer in the first argument must be greater than
    01530 ** or equal to the product of the second and third arguments.  The buffer
    01531 ** must be aligned to an 8-byte boundary.  ^If the second argument to
    01532 ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally
    01533 ** rounded down to the next smaller multiple of 8.  ^(The lookaside memory
    01534 ** configuration for a database connection can only be changed when that
    01535 ** connection is not currently using lookaside memory, or in other words
    01536 ** when the "current value" returned by
    01537 ** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero.
    01538 ** Any attempt to change the lookaside memory configuration when lookaside
    01539 ** memory is in use leaves the configuration unchanged and returns
    01540 ** [SQLITE_BUSY].)^</dd>
    01541 **
    01542 ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt>
    01543 ** <dd> ^This option is used to enable or disable the enforcement of
    01544 ** [foreign key constraints].  There should be two additional arguments.
    01545 ** The first argument is an integer which is 0 to disable FK enforcement,
    01546 ** positive to enable FK enforcement or negative to leave FK enforcement
    01547 ** unchanged.  The second parameter is a pointer to an integer into which
    01548 ** is written 0 or 1 to indicate whether FK enforcement is off or on
    01549 ** following this call.  The second parameter may be a NULL pointer, in
    01550 ** which case the FK enforcement setting is not reported back. </dd>
    01551 **
    01552 ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt>
    01553 ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].
    01554 ** There should be two additional arguments.
    01555 ** The first argument is an integer which is 0 to disable triggers,
    01556 ** positive to enable triggers or negative to leave the setting unchanged.
    01557 ** The second parameter is a pointer to an integer into which
    01558 ** is written 0 or 1 to indicate whether triggers are disabled or enabled
    01559 ** following this call.  The second parameter may be a NULL pointer, in
    01560 ** which case the trigger setting is not reported back. </dd>
    01561 **
    01562 ** </dl>
    01563 */
    01564 #define SQLITE_DBCONFIG_LOOKASIDE       1001  /* void* int int */
    01565 #define SQLITE_DBCONFIG_ENABLE_FKEY     1002  /* int int* */
    01566 #define SQLITE_DBCONFIG_ENABLE_TRIGGER  1003  /* int int* */
    01567
    01568
    01569 /*
    01570 ** CAPI3REF: Enable Or Disable Extended Result Codes
    01571 **
    01572 ** ^The sqlite3_extended_result_codes() routine enables or disables the
    01573 ** [extended result codes] feature of SQLite. ^The extended result
    01574 ** codes are disabled by default for historical compatibility.
    01575 */
    01576 SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff);
    01577
    01578 /*
    01579 ** CAPI3REF: Last Insert Rowid
    01580 **
    01581 ** ^Each entry in an SQLite table has a unique 64-bit signed
    01582 ** integer key called the [ROWID | "rowid"]. ^The rowid is always available
    01583 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
    01584 ** names are not also used by explicitly declared columns. ^If
    01585 ** the table has a column of type [INTEGER PRIMARY KEY] then that column
    01586 ** is another alias for the rowid.
    01587 **
    01588 ** ^This routine returns the [rowid] of the most recent
    01589 ** successful [INSERT] into the database from the [database connection]
    01590 ** in the first argument.  ^As of SQLite version 3.7.7, this routines
    01591 ** records the last insert rowid of both ordinary tables and [virtual tables].
    01592 ** ^If no successful [INSERT]s
    01593 ** have ever occurred on that database connection, zero is returned.
    01594 **
    01595 ** ^(If an [INSERT] occurs within a trigger or within a [virtual table]
    01596 ** method, then this routine will return the [rowid] of the inserted
    01597 ** row as long as the trigger or virtual table method is running.
    01598 ** But once the trigger or virtual table method ends, the value returned
    01599 ** by this routine reverts to what it was before the trigger or virtual
    01600 ** table method began.)^
    01601 **
    01602 ** ^An [INSERT] that fails due to a constraint violation is not a
    01603 ** successful [INSERT] and does not change the value returned by this
    01604 ** routine.  ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
    01605 ** and INSERT OR ABORT make no changes to the return value of this
    01606 ** routine when their insertion fails.  ^(When INSERT OR REPLACE
    01607 ** encounters a constraint violation, it does not fail.  The
    01608 ** INSERT continues to completion after deleting rows that caused
    01609 ** the constraint problem so INSERT OR REPLACE will always change
    01610 ** the return value of this interface.)^
    01611 **
    01612 ** ^For the purposes of this routine, an [INSERT] is considered to
    01613 ** be successful even if it is subsequently rolled back.
    01614 **
    01615 ** This function is accessible to SQL statements via the
    01616 ** [last_insert_rowid() SQL function].
    01617 **
    01618 ** If a separate thread performs a new [INSERT] on the same
    01619 ** database connection while the [sqlite3_last_insert_rowid()]
    01620 ** function is running and thus changes the last insert [rowid],
    01621 ** then the value returned by [sqlite3_last_insert_rowid()] is
    01622 ** unpredictable and might not equal either the old or the new
    01623 ** last insert [rowid].
    01624 */
    01625 SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);
    01626
    01627 /*
    01628 ** CAPI3REF: Count The Number Of Rows Modified
    01629 **
    01630 ** ^This function returns the number of database rows that were changed
    01631 ** or inserted or deleted by the most recently completed SQL statement
    01632 ** on the [database connection] specified by the first parameter.
    01633 ** ^(Only changes that are directly specified by the [INSERT], [UPDATE],
    01634 ** or [DELETE] statement are counted.  Auxiliary changes caused by
    01635 ** triggers or [foreign key actions] are not counted.)^ Use the
    01636 ** [sqlite3_total_changes()] function to find the total number of changes
    01637 ** including changes caused by triggers and foreign key actions.
    01638 **
    01639 ** ^Changes to a view that are simulated by an [INSTEAD OF trigger]
    01640 ** are not counted.  Only real table changes are counted.
    01641 **
    01642 ** ^(A "row change" is a change to a single row of a single table
    01643 ** caused by an INSERT, DELETE, or UPDATE statement.  Rows that
    01644 ** are changed as side effects of [REPLACE] constraint resolution,
    01645 ** rollback, ABORT processing, [DROP TABLE], or by any other
    01646 ** mechanisms do not count as direct row changes.)^
    01647 **
    01648 ** A "trigger context" is a scope of execution that begins and
    01649 ** ends with the script of a [CREATE TRIGGER | trigger].
    01650 ** Most SQL statements are
    01651 ** evaluated outside of any trigger.  This is the "top level"
    01652 ** trigger context.  If a trigger fires from the top level, a
    01653 ** new trigger context is entered for the duration of that one
    01654 ** trigger.  Subtriggers create subcontexts for their duration.
    01655 **
    01656 ** ^Calling [sqlite3_exec()] or [sqlite3_step()] recursively does
    01657 ** not create a new trigger context.
    01658 **
    01659 ** ^This function returns the number of direct row changes in the
    01660 ** most recent INSERT, UPDATE, or DELETE statement within the same
    01661 ** trigger context.
    01662 **
    01663 ** ^Thus, when called from the top level, this function returns the
    01664 ** number of changes in the most recent INSERT, UPDATE, or DELETE
    01665 ** that also occurred at the top level.  ^(Within the body of a trigger,
    01666 ** the sqlite3_changes() interface can be called to find the number of
    01667 ** changes in the most recently completed INSERT, UPDATE, or DELETE
    01668 ** statement within the body of the same trigger.
    01669 ** However, the number returned does not include changes
    01670 ** caused by subtriggers since those have their own context.)^
    01671 **
    01672 ** See also the [sqlite3_total_changes()] interface, the
    01673 ** [count_changes pragma], and the [changes() SQL function].
    01674 **
    01675 ** If a separate thread makes changes on the same database connection
    01676 ** while [sqlite3_changes()] is running then the value returned
    01677 ** is unpredictable and not meaningful.
    01678 */
    01679 SQLITE_API int sqlite3_changes(sqlite3*);
    01680
    01681 /*
    01682 ** CAPI3REF: Total Number Of Rows Modified
    01683 **
    01684 ** ^This function returns the number of row changes caused by [INSERT],
    01685 ** [UPDATE] or [DELETE] statements since the [database connection] was opened.
    01686 ** ^(The count returned by sqlite3_total_changes() includes all changes
    01687 ** from all [CREATE TRIGGER | trigger] contexts and changes made by
    01688 ** [foreign key actions]. However,
    01689 ** the count does not include changes used to implement [REPLACE] constraints,
    01690 ** do rollbacks or ABORT processing, or [DROP TABLE] processing.  The
    01691 ** count does not include rows of views that fire an [INSTEAD OF trigger],
    01692 ** though if the INSTEAD OF trigger makes changes of its own, those changes
    01693 ** are counted.)^
    01694 ** ^The sqlite3_total_changes() function counts the changes as soon as
    01695 ** the statement that makes them is completed (when the statement handle
    01696 ** is passed to [sqlite3_reset()] or [sqlite3_finalize()]).
    01697 **
    01698 ** See also the [sqlite3_changes()] interface, the
    01699 ** [count_changes pragma], and the [total_changes() SQL function].
    01700 **
    01701 ** If a separate thread makes changes on the same database connection
    01702 ** while [sqlite3_total_changes()] is running then the value
    01703 ** returned is unpredictable and not meaningful.
    01704 */
    01705 SQLITE_API int sqlite3_total_changes(sqlite3*);
    01706
    01707 /*
    01708 ** CAPI3REF: Interrupt A Long-Running Query
    01709 **
    01710 ** ^This function causes any pending database operation to abort and
    01711 ** return at its earliest opportunity. This routine is typically
    01712 ** called in response to a user action such as pressing "Cancel"
    01713 ** or Ctrl-C where the user wants a long query operation to halt
    01714 ** immediately.
    01715 **
    01716 ** ^It is safe to call this routine from a thread different from the
    01717 ** thread that is currently running the database operation.  But it
    01718 ** is not safe to call this routine with a [database connection] that
    01719 ** is closed or might close before sqlite3_interrupt() returns.
    01720 **
    01721 ** ^If an SQL operation is very nearly finished at the time when
    01722 ** sqlite3_interrupt() is called, then it might not have an opportunity
    01723 ** to be interrupted and might continue to completion.
    01724 **
    01725 ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
    01726 ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
    01727 ** that is inside an explicit transaction, then the entire transaction
    01728 ** will be rolled back automatically.
    01729 **
    01730 ** ^The sqlite3_interrupt(D) call is in effect until all currently running
    01731 ** SQL statements on [database connection] D complete.  ^Any new SQL statements
    01732 ** that are started after the sqlite3_interrupt() call and before the
    01733 ** running statements reaches zero are interrupted as if they had been
    01734 ** running prior to the sqlite3_interrupt() call.  ^New SQL statements
    01735 ** that are started after the running statement count reaches zero are
    01736 ** not effected by the sqlite3_interrupt().
    01737 ** ^A call to sqlite3_interrupt(D) that occurs when there are no running
    01738 ** SQL statements is a no-op and has no effect on SQL statements
    01739 ** that are started after the sqlite3_interrupt() call returns.
    01740 **
    01741 ** If the database connection closes while [sqlite3_interrupt()]
    01742 ** is running then bad things will likely happen.
    01743 */
    01744 SQLITE_API void sqlite3_interrupt(sqlite3*);
    01745
    01746 /*
    01747 ** CAPI3REF: Determine If An SQL Statement Is Complete
    01748 **
    01749 ** These routines are useful during command-line input to determine if the
    01750 ** currently entered text seems to form a complete SQL statement or
    01751 ** if additional input is needed before sending the text into
    01752 ** SQLite for parsing.  ^These routines return 1 if the input string
    01753 ** appears to be a complete SQL statement.  ^A statement is judged to be
    01754 ** complete if it ends with a semicolon token and is not a prefix of a
    01755 ** well-formed CREATE TRIGGER statement.  ^Semicolons that are embedded within
    01756 ** string literals or quoted identifier names or comments are not
    01757 ** independent tokens (they are part of the token in which they are
    01758 ** embedded) and thus do not count as a statement terminator.  ^Whitespace
    01759 ** and comments that follow the final semicolon are ignored.
    01760 **
    01761 ** ^These routines return 0 if the statement is incomplete.  ^If a
    01762 ** memory allocation fails, then SQLITE_NOMEM is returned.
    01763 **
    01764 ** ^These routines do not parse the SQL statements thus
    01765 ** will not detect syntactically incorrect SQL.
    01766 **
    01767 ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior
    01768 ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
    01769 ** automatically by sqlite3_complete16().  If that initialization fails,
    01770 ** then the return value from sqlite3_complete16() will be non-zero
    01771 ** regardless of whether or not the input SQL is complete.)^
    01772 **
    01773 ** The input to [sqlite3_complete()] must be a zero-terminated
    01774 ** UTF-8 string.
    01775 **
    01776 ** The input to [sqlite3_complete16()] must be a zero-terminated
    01777 ** UTF-16 string in native byte order.
    01778 */
    01779 SQLITE_API int sqlite3_complete(const char *sql);
    01780 SQLITE_API int sqlite3_complete16(const void *sql);
    01781
    01782 /*
    01783 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
    01784 **
    01785 ** ^This routine sets a callback function that might be invoked whenever
    01786 ** an attempt is made to open a database table that another thread
    01787 ** or process has locked.
    01788 **
    01789 ** ^If the busy callback is NULL, then [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]
    01790 ** is returned immediately upon encountering the lock.  ^If the busy callback
    01791 ** is not NULL, then the callback might be invoked with two arguments.
    01792 **
    01793 ** ^The first argument to the busy handler is a copy of the void* pointer which
    01794 ** is the third argument to sqlite3_busy_handler().  ^The second argument to
    01795 ** the busy handler callback is the number of times that the busy handler has
    01796 ** been invoked for this locking event.  ^If the
    01797 ** busy callback returns 0, then no additional attempts are made to
    01798 ** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned.
    01799 ** ^If the callback returns non-zero, then another attempt
    01800 ** is made to open the database for reading and the cycle repeats.
    01801 **
    01802 ** The presence of a busy handler does not guarantee that it will be invoked
    01803 ** when there is lock contention. ^If SQLite determines that invoking the busy
    01804 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
    01805 ** or [SQLITE_IOERR_BLOCKED] instead of invoking the busy handler.
    01806 ** Consider a scenario where one process is holding a read lock that
    01807 ** it is trying to promote to a reserved lock and
    01808 ** a second process is holding a reserved lock that it is trying
    01809 ** to promote to an exclusive lock.  The first process cannot proceed
    01810 ** because it is blocked by the second and the second process cannot
    01811 ** proceed because it is blocked by the first.  If both processes
    01812 ** invoke the busy handlers, neither will make any progress.  Therefore,
    01813 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
    01814 ** will induce the first process to release its read lock and allow
    01815 ** the second process to proceed.
    01816 **
    01817 ** ^The default busy callback is NULL.
    01818 **
    01819 ** ^The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED]
    01820 ** when SQLite is in the middle of a large transaction where all the
    01821 ** changes will not fit into the in-memory cache.  SQLite will
    01822 ** already hold a RESERVED lock on the database file, but it needs
    01823 ** to promote this lock to EXCLUSIVE so that it can spill cache
    01824 ** pages into the database file without harm to concurrent
    01825 ** readers.  ^If it is unable to promote the lock, then the in-memory
    01826 ** cache will be left in an inconsistent state and so the error
    01827 ** code is promoted from the relatively benign [SQLITE_BUSY] to
    01828 ** the more severe [SQLITE_IOERR_BLOCKED].  ^This error code promotion
    01829 ** forces an automatic rollback of the changes.  See the
    01830 ** <a href="/cvstrac/wiki?p=CorruptionFollowingBusyError">
    01831 ** CorruptionFollowingBusyError</a> wiki page for a discussion of why
    01832 ** this is important.
    01833 **
    01834 ** ^(There can only be a single busy handler defined for each
    01835 ** [database connection].  Setting a new busy handler clears any
    01836 ** previously set handler.)^  ^Note that calling [sqlite3_busy_timeout()]
    01837 ** will also set or clear the busy handler.
    01838 **
    01839 ** The busy callback should not take any actions which modify the
    01840 ** database connection that invoked the busy handler.  Any such actions
    01841 ** result in undefined behavior.
    01842 **
    01843 ** A busy handler must not close the database connection
    01844 ** or [prepared statement] that invoked the busy handler.
    01845 */
    01846 SQLITE_API int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*);
    01847
    01848 /*
    01849 ** CAPI3REF: Set A Busy Timeout
    01850 **
    01851 ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
    01852 ** for a specified amount of time when a table is locked.  ^The handler
    01853 ** will sleep multiple times until at least "ms" milliseconds of sleeping
    01854 ** have accumulated.  ^After at least "ms" milliseconds of sleeping,
    01855 ** the handler returns 0 which causes [sqlite3_step()] to return
    01856 ** [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED].
    01857 **
    01858 ** ^Calling this routine with an argument less than or equal to zero
    01859 ** turns off all busy handlers.
    01860 **
    01861 ** ^(There can only be a single busy handler for a particular
    01862 ** [database connection] any any given moment.  If another busy handler
    01863 ** was defined  (using [sqlite3_busy_handler()]) prior to calling
    01864 ** this routine, that other busy handler is cleared.)^
    01865 */
    01866 SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms);
    01867
    01868 /*
    01869 ** CAPI3REF: Convenience Routines For Running Queries
    01870 **
    01871 ** This is a legacy interface that is preserved for backwards compatibility.
    01872 ** Use of this interface is not recommended.
    01873 **
    01874 ** Definition: A <b>result table</b> is memory data structure created by the
    01875 ** [sqlite3_get_table()] interface.  A result table records the
    01876 ** complete query results from one or more queries.
    01877 **
    01878 ** The table conceptually has a number of rows and columns.  But
    01879 ** these numbers are not part of the result table itself.  These
    01880 ** numbers are obtained separately.  Let N be the number of rows
    01881 ** and M be the number of columns.
    01882 **
    01883 ** A result table is an array of pointers to zero-terminated UTF-8 strings.
    01884 ** There are (N+1)*M elements in the array.  The first M pointers point
    01885 ** to zero-terminated strings that  contain the names of the columns.
    01886 ** The remaining entries all point to query results.  NULL values result
    01887 ** in NULL pointers.  All other values are in their UTF-8 zero-terminated
    01888 ** string representation as returned by [sqlite3_column_text()].
    01889 **
    01890 ** A result table might consist of one or more memory allocations.
    01891 ** It is not safe to pass a result table directly to [sqlite3_free()].
    01892 ** A result table should be deallocated using [sqlite3_free_table()].
    01893 **
    01894 ** ^(As an example of the result table format, suppose a query result
    01895 ** is as follows:
    01896 **
    01897 ** <blockquote><pre>
    01898 **        Name        | Age
    01899 **        -----------------------
    01900 **        Alice       | 43
    01901 **        Bob         | 28
    01902 **        Cindy       | 21
    01903 ** </pre></blockquote>
    01904 **
    01905 ** There are two column (M==2) and three rows (N==3).  Thus the
    01906 ** result table has 8 entries.  Suppose the result table is stored
    01907 ** in an array names azResult.  Then azResult holds this content:
    01908 **
    01909 ** <blockquote><pre>
    01910 **        azResult&#91;0] = "Name";
    01911 **        azResult&#91;1] = "Age";
    01912 **        azResult&#91;2] = "Alice";
    01913 **        azResult&#91;3] = "43";
    01914 **        azResult&#91;4] = "Bob";
    01915 **        azResult&#91;5] = "28";
    01916 **        azResult&#91;6] = "Cindy";
    01917 **        azResult&#91;7] = "21";
    01918 ** </pre></blockquote>)^
    01919 **
    01920 ** ^The sqlite3_get_table() function evaluates one or more
    01921 ** semicolon-separated SQL statements in the zero-terminated UTF-8
    01922 ** string of its 2nd parameter and returns a result table to the
    01923 ** pointer given in its 3rd parameter.
    01924 **
    01925 ** After the application has finished with the result from sqlite3_get_table(),
    01926 ** it must pass the result table pointer to sqlite3_free_table() in order to
    01927 ** release the memory that was malloced.  Because of the way the
    01928 ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
    01929 ** function must not try to call [sqlite3_free()] directly.  Only
    01930 ** [sqlite3_free_table()] is able to release the memory properly and safely.
    01931 **
    01932 ** The sqlite3_get_table() interface is implemented as a wrapper around
    01933 ** [sqlite3_exec()].  The sqlite3_get_table() routine does not have access
    01934 ** to any internal data structures of SQLite.  It uses only the public
    01935 ** interface defined here.  As a consequence, errors that occur in the
    01936 ** wrapper layer outside of the internal [sqlite3_exec()] call are not
    01937 ** reflected in subsequent calls to [sqlite3_errcode()] or
    01938 ** [sqlite3_errmsg()].
    01939 */
    01940 SQLITE_API int sqlite3_get_table(
    01941   sqlite3 *db,          /* An open database */
    01942   const char *zSql,     /* SQL to be evaluated */
    01943   char ***pazResult,    /* Results of the query */
    01944   int *pnRow,           /* Number of result rows written here */
    01945   int *pnColumn,        /* Number of result columns written here */
    01946   char **pzErrmsg       /* Error msg written here */
    01947 );
    01948 SQLITE_API void sqlite3_free_table(char **result);
    01949
    01950 /*
    01951 ** CAPI3REF: Formatted String Printing Functions
    01952 **
    01953 ** These routines are work-alikes of the "printf()" family of functions
    01954 ** from the standard C library.
    01955 **
    01956 ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
    01957 ** results into memory obtained from [sqlite3_malloc()].
    01958 ** The strings returned by these two routines should be
    01959 ** released by [sqlite3_free()].  ^Both routines return a
    01960 ** NULL pointer if [sqlite3_malloc()] is unable to allocate enough
    01961 ** memory to hold the resulting string.
    01962 **
    01963 ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
    01964 ** the standard C library.  The result is written into the
    01965 ** buffer supplied as the second parameter whose size is given by
    01966 ** the first parameter. Note that the order of the
    01967 ** first two parameters is reversed from snprintf().)^  This is an
    01968 ** historical accident that cannot be fixed without breaking
    01969 ** backwards compatibility.  ^(Note also that sqlite3_snprintf()
    01970 ** returns a pointer to its buffer instead of the number of
    01971 ** characters actually written into the buffer.)^  We admit that
    01972 ** the number of characters written would be a more useful return
    01973 ** value but we cannot change the implementation of sqlite3_snprintf()
    01974 ** now without breaking compatibility.
    01975 **
    01976 ** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
    01977 ** guarantees that the buffer is always zero-terminated.  ^The first
    01978 ** parameter "n" is the total size of the buffer, including space for
    01979 ** the zero terminator.  So the longest string that can be completely
    01980 ** written will be n-1 characters.
    01981 **
    01982 ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
    01983 **
    01984 ** These routines all implement some additional formatting
    01985 ** options that are useful for constructing SQL statements.
    01986 ** All of the usual printf() formatting options apply.  In addition, there
    01987 ** is are "%q", "%Q", and "%z" options.
    01988 **
    01989 ** ^(The %q option works like %s in that it substitutes a null-terminated
    01990 ** string from the argument list.  But %q also doubles every '\'' character.
    01991 ** %q is designed for use inside a string literal.)^  By doubling each '\''
    01992 ** character it escapes that character and allows it to be inserted into
    01993 ** the string.
    01994 **
    01995 ** For example, assume the string variable zText contains text as follows:
    01996 **
    01997 ** <blockquote><pre>
    01998 **  char *zText = "It's a happy day!";
    01999 ** </pre></blockquote>
    02000 **
    02001 ** One can use this text in an SQL statement as follows:
    02002 **
    02003 ** <blockquote><pre>
    02004 **  char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText);
    02005 **  sqlite3_exec(db, zSQL, 0, 0, 0);
    02006 **  sqlite3_free(zSQL);
    02007 ** </pre></blockquote>
    02008 **
    02009 ** Because the %q format string is used, the '\'' character in zText
    02010 ** is escaped and the SQL generated is as follows:
    02011 **
    02012 ** <blockquote><pre>
    02013 **  INSERT INTO table1 VALUES('It''s a happy day!')
    02014 ** </pre></blockquote>
    02015 **
    02016 ** This is correct.  Had we used %s instead of %q, the generated SQL
    02017 ** would have looked like this:
    02018 **
    02019 ** <blockquote><pre>
    02020 **  INSERT INTO table1 VALUES('It's a happy day!');
    02021 ** </pre></blockquote>
    02022 **
    02023 ** This second example is an SQL syntax error.  As a general rule you should
    02024 ** always use %q instead of %s when inserting text into a string literal.
    02025 **
    02026 ** ^(The %Q option works like %q except it also adds single quotes around
    02027 ** the outside of the total string.  Additionally, if the parameter in the
    02028 ** argument list is a NULL pointer, %Q substitutes the text "NULL" (without
    02029 ** single quotes).)^  So, for example, one could say:
    02030 **
    02031 ** <blockquote><pre>
    02032 **  char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText);
    02033 **  sqlite3_exec(db, zSQL, 0, 0, 0);
    02034 **  sqlite3_free(zSQL);
    02035 ** </pre></blockquote>
    02036 **
    02037 ** The code above will render a correct SQL statement in the zSQL
    02038 ** variable even if the zText variable is a NULL pointer.
    02039 **
    02040 ** ^(The "%z" formatting option works like "%s" but with the
    02041 ** addition that after the string has been read and copied into
    02042 ** the result, [sqlite3_free()] is called on the input string.)^
    02043 */
    02044 SQLITE_API char *sqlite3_mprintf(const char*,...);
    02045 SQLITE_API char *sqlite3_vmprintf(const char*, va_list);
    02046 SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...);
    02047 SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list);
    02048
    02049 /*
    02050 ** CAPI3REF: Memory Allocation Subsystem
    02051 **
    02052 ** The SQLite core uses these three routines for all of its own
    02053 ** internal memory allocation needs. "Core" in the previous sentence
    02054 ** does not include operating-system specific VFS implementation.  The
    02055 ** Windows VFS uses native malloc() and free() for some operations.
    02056 **
    02057 ** ^The sqlite3_malloc() routine returns a pointer to a block
    02058 ** of memory at least N bytes in length, where N is the parameter.
    02059 ** ^If sqlite3_malloc() is unable to obtain sufficient free
    02060 ** memory, it returns a NULL pointer.  ^If the parameter N to
    02061 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
    02062 ** a NULL pointer.
    02063 **
    02064 ** ^Calling sqlite3_free() with a pointer previously returned
    02065 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
    02066 ** that it might be reused.  ^The sqlite3_free() routine is
    02067 ** a no-op if is called with a NULL pointer.  Passing a NULL pointer
    02068 ** to sqlite3_free() is harmless.  After being freed, memory
    02069 ** should neither be read nor written.  Even reading previously freed
    02070 ** memory might result in a segmentation fault or other severe error.
    02071 ** Memory corruption, a segmentation fault, or other severe error
    02072 ** might result if sqlite3_free() is called with a non-NULL pointer that
    02073 ** was not obtained from sqlite3_malloc() or sqlite3_realloc().
    02074 **
    02075 ** ^(The sqlite3_realloc() interface attempts to resize a
    02076 ** prior memory allocation to be at least N bytes, where N is the
    02077 ** second parameter.  The memory allocation to be resized is the first
    02078 ** parameter.)^ ^ If the first parameter to sqlite3_realloc()
    02079 ** is a NULL pointer then its behavior is identical to calling
    02080 ** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc().
    02081 ** ^If the second parameter to sqlite3_realloc() is zero or
    02082 ** negative then the behavior is exactly the same as calling
    02083 ** sqlite3_free(P) where P is the first parameter to sqlite3_realloc().
    02084 ** ^sqlite3_realloc() returns a pointer to a memory allocation
    02085 ** of at least N bytes in size or NULL if sufficient memory is unavailable.
    02086 ** ^If M is the size of the prior allocation, then min(N,M) bytes
    02087 ** of the prior allocation are copied into the beginning of buffer returned
    02088 ** by sqlite3_realloc() and the prior allocation is freed.
    02089 ** ^If sqlite3_realloc() returns NULL, then the prior allocation
    02090 ** is not freed.
    02091 **
    02092 ** ^The memory returned by sqlite3_malloc() and sqlite3_realloc()
    02093 ** is always aligned to at least an 8 byte boundary, or to a
    02094 ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
    02095 ** option is used.
    02096 **
    02097 ** In SQLite version 3.5.0 and 3.5.1, it was possible to define
    02098 ** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in
    02099 ** implementation of these routines to be omitted.  That capability
    02100 ** is no longer provided.  Only built-in memory allocators can be used.
    02101 **
    02102 ** The Windows OS interface layer calls
    02103 ** the system malloc() and free() directly when converting
    02104 ** filenames between the UTF-8 encoding used by SQLite
    02105 ** and whatever filename encoding is used by the particular Windows
    02106 ** installation.  Memory allocation errors are detected, but
    02107 ** they are reported back as [SQLITE_CANTOPEN] or
    02108 ** [SQLITE_IOERR] rather than [SQLITE_NOMEM].
    02109 **
    02110 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
    02111 ** must be either NULL or else pointers obtained from a prior
    02112 ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
    02113 ** not yet been released.
    02114 **
    02115 ** The application must not read or write any part of
    02116 ** a block of memory after it has been released using
    02117 ** [sqlite3_free()] or [sqlite3_realloc()].
    02118 */
    02119 SQLITE_API void *sqlite3_malloc(int);
    02120 SQLITE_API void *sqlite3_realloc(void*, int);
    02121 SQLITE_API void sqlite3_free(void*);
    02122
    02123 /*
    02124 ** CAPI3REF: Memory Allocator Statistics
    02125 **
    02126 ** SQLite provides these two interfaces for reporting on the status
    02127 ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
    02128 ** routines, which form the built-in memory allocation subsystem.
    02129 **
    02130 ** ^The [sqlite3_memory_used()] routine returns the number of bytes
    02131 ** of memory currently outstanding (malloced but not freed).
    02132 ** ^The [sqlite3_memory_highwater()] routine returns the maximum
    02133 ** value of [sqlite3_memory_used()] since the high-water mark
    02134 ** was last reset.  ^The values returned by [sqlite3_memory_used()] and
    02135 ** [sqlite3_memory_highwater()] include any overhead
    02136 ** added by SQLite in its implementation of [sqlite3_malloc()],
    02137 ** but not overhead added by the any underlying system library
    02138 ** routines that [sqlite3_malloc()] may call.
    02139 **
    02140 ** ^The memory high-water mark is reset to the current value of
    02141 ** [sqlite3_memory_used()] if and only if the parameter to
    02142 ** [sqlite3_memory_highwater()] is true.  ^The value returned
    02143 ** by [sqlite3_memory_highwater(1)] is the high-water mark
    02144 ** prior to the reset.
    02145 */
    02146 SQLITE_API sqlite3_int64 sqlite3_memory_used(void);
    02147 SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag);
    02148
    02149 /*
    02150 ** CAPI3REF: Pseudo-Random Number Generator
    02151 **
    02152 ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
    02153 ** select random [ROWID | ROWIDs] when inserting new records into a table that
    02154 ** already uses the largest possible [ROWID].  The PRNG is also used for
    02155 ** the build-in random() and randomblob() SQL functions.  This interface allows
    02156 ** applications to access the same PRNG for other purposes.
    02157 **
    02158 ** ^A call to this routine stores N bytes of randomness into buffer P.
    02159 **
    02160 ** ^The first time this routine is invoked (either internally or by
    02161 ** the application) the PRNG is seeded using randomness obtained
    02162 ** from the xRandomness method of the default [sqlite3_vfs] object.
    02163 ** ^On all subsequent invocations, the pseudo-randomness is generated
    02164 ** internally and without recourse to the [sqlite3_vfs] xRandomness
    02165 ** method.
    02166 */
    02167 SQLITE_API void sqlite3_randomness(int N, void *P);
    02168
    02169 /*
    02170 ** CAPI3REF: Compile-Time Authorization Callbacks
    02171 **
    02172 ** ^This routine registers an authorizer callback with a particular
    02173 ** [database connection], supplied in the first argument.
    02174 ** ^The authorizer callback is invoked as SQL statements are being compiled
    02175 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
    02176 ** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()].  ^At various
    02177 ** points during the compilation process, as logic is being created
    02178 ** to perform various actions, the authorizer callback is invoked to
    02179 ** see if those actions are allowed.  ^The authorizer callback should
    02180 ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
    02181 ** specific action but allow the SQL statement to continue to be
    02182 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
    02183 ** rejected with an error.  ^If the authorizer callback returns
    02184 ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
    02185 ** then the [sqlite3_prepare_v2()] or equivalent call that triggered
    02186 ** the authorizer will fail with an error message.
    02187 **
    02188 ** When the callback returns [SQLITE_OK], that means the operation
    02189 ** requested is ok.  ^When the callback returns [SQLITE_DENY], the
    02190 ** [sqlite3_prepare_v2()] or equivalent call that triggered the
    02191 ** authorizer will fail with an error message explaining that
    02192 ** access is denied.
    02193 **
    02194 ** ^The first parameter to the authorizer callback is a copy of the third
    02195 ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
    02196 ** to the callback is an integer [SQLITE_COPY | action code] that specifies
    02197 ** the particular action to be authorized. ^The third through sixth parameters
    02198 ** to the callback are zero-terminated strings that contain additional
    02199 ** details about the action to be authorized.
    02200 **
    02201 ** ^If the action code is [SQLITE_READ]
    02202 ** and the callback returns [SQLITE_IGNORE] then the
    02203 ** [prepared statement] statement is constructed to substitute
    02204 ** a NULL value in place of the table column that would have
    02205 ** been read if [SQLITE_OK] had been returned.  The [SQLITE_IGNORE]
    02206 ** return can be used to deny an untrusted user access to individual
    02207 ** columns of a table.
    02208 ** ^If the action code is [SQLITE_DELETE] and the callback returns
    02209 ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
    02210 ** [truncate optimization] is disabled and all rows are deleted individually.
    02211 **
    02212 ** An authorizer is used when [sqlite3_prepare | preparing]
    02213 ** SQL statements from an untrusted source, to ensure that the SQL statements
    02214 ** do not try to access data they are not allowed to see, or that they do not
    02215 ** try to execute malicious statements that damage the database.  For
    02216 ** example, an application may allow a user to enter arbitrary
    02217 ** SQL queries for evaluation by a database.  But the application does
    02218 ** not want the user to be able to make arbitrary changes to the
    02219 ** database.  An authorizer could then be put in place while the
    02220 ** user-entered SQL is being [sqlite3_prepare | prepared] that
    02221 ** disallows everything except [SELECT] statements.
    02222 **
    02223 ** Applications that need to process SQL from untrusted sources
    02224 ** might also consider lowering resource limits using [sqlite3_limit()]
    02225 ** and limiting database size using the [max_page_count] [PRAGMA]
    02226 ** in addition to using an authorizer.
    02227 **
    02228 ** ^(Only a single authorizer can be in place on a database connection
    02229 ** at a time.  Each call to sqlite3_set_authorizer overrides the
    02230 ** previous call.)^  ^Disable the authorizer by installing a NULL callback.
    02231 ** The authorizer is disabled by default.
    02232 **
    02233 ** The authorizer callback must not do anything that will modify
    02234 ** the database connection that invoked the authorizer callback.
    02235 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
    02236 ** database connections for the meaning of "modify" in this paragraph.
    02237 **
    02238 ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
    02239 ** statement might be re-prepared during [sqlite3_step()] due to a
    02240 ** schema change.  Hence, the application should ensure that the
    02241 ** correct authorizer callback remains in place during the [sqlite3_step()].
    02242 **
    02243 ** ^Note that the authorizer callback is invoked only during
    02244 ** [sqlite3_prepare()] or its variants.  Authorization is not
    02245 ** performed during statement evaluation in [sqlite3_step()], unless
    02246 ** as stated in the previous paragraph, sqlite3_step() invokes
    02247 ** sqlite3_prepare_v2() to reprepare a statement after a schema change.
    02248 */
    02249 SQLITE_API int sqlite3_set_authorizer(
    02250   sqlite3*,
    02251   int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
    02252   void *pUserData
    02253 );
    02254
    02255 /*
    02256 ** CAPI3REF: Authorizer Return Codes
    02257 **
    02258 ** The [sqlite3_set_authorizer | authorizer callback function] must
    02259 ** return either [SQLITE_OK] or one of these two constants in order
    02260 ** to signal SQLite whether or not the action is permitted.  See the
    02261 ** [sqlite3_set_authorizer | authorizer documentation] for additional
    02262 ** information.
    02263 **
    02264 ** Note that SQLITE_IGNORE is also used as a [SQLITE_ROLLBACK | return code]
    02265 ** from the [sqlite3_vtab_on_conflict()] interface.
    02266 */
    02267 #define SQLITE_DENY   1   /* Abort the SQL statement with an error */
    02268 #define SQLITE_IGNORE 2   /* Don't allow access, but don't generate an error */
    02269
    02270 /*
    02271 ** CAPI3REF: Authorizer Action Codes
    02272 **
    02273 ** The [sqlite3_set_authorizer()] interface registers a callback function
    02274 ** that is invoked to authorize certain SQL statement actions.  The
    02275 ** second parameter to the callback is an integer code that specifies
    02276 ** what action is being authorized.  These are the integer action codes that
    02277 ** the authorizer callback may be passed.
    02278 **
    02279 ** These action code values signify what kind of operation is to be
    02280 ** authorized.  The 3rd and 4th parameters to the authorization
    02281 ** callback function will be parameters or NULL depending on which of these
    02282 ** codes is used as the second parameter.  ^(The 5th parameter to the
    02283 ** authorizer callback is the name of the database ("main", "temp",
    02284 ** etc.) if applicable.)^  ^The 6th parameter to the authorizer callback
    02285 ** is the name of the inner-most trigger or view that is responsible for
    02286 ** the access attempt or NULL if this access attempt is directly from
    02287 ** top-level SQL code.
    02288 */
    02289 /******************************************* 3rd ************ 4th ***********/
    02290 #define SQLITE_CREATE_INDEX          1   /* Index Name      Table Name      */
    02291 #define SQLITE_CREATE_TABLE          2   /* Table Name      NULL            */
    02292 #define SQLITE_CREATE_TEMP_INDEX     3   /* Index Name      Table Name      */
    02293 #define SQLITE_CREATE_TEMP_TABLE     4   /* Table Name      NULL            */
    02294 #define SQLITE_CREATE_TEMP_TRIGGER   5   /* Trigger Name    Table Name      */
    02295 #define SQLITE_CREATE_TEMP_VIEW      6   /* View Name       NULL            */
    02296 #define SQLITE_CREATE_TRIGGER        7   /* Trigger Name    Table Name      */
    02297 #define SQLITE_CREATE_VIEW           8   /* View Name       NULL            */
    02298 #define SQLITE_DELETE                9   /* Table Name      NULL            */
    02299 #define SQLITE_DROP_INDEX           10   /* Index Name      Table Name      */
    02300 #define SQLITE_DROP_TABLE           11   /* Table Name      NULL            */
    02301 #define SQLITE_DROP_TEMP_INDEX      12   /* Index Name      Table Name      */
    02302 #define SQLITE_DROP_TEMP_TABLE      13   /* Table Name      NULL            */
    02303 #define SQLITE_DROP_TEMP_TRIGGER    14   /* Trigger Name    Table Name      */
    02304 #define SQLITE_DROP_TEMP_VIEW       15   /* View Name       NULL            */
    02305 #define SQLITE_DROP_TRIGGER         16   /* Trigger Name    Table Name      */
    02306 #define SQLITE_DROP_VIEW            17   /* View Name       NULL            */
    02307 #define SQLITE_INSERT               18   /* Table Name      NULL            */
    02308 #define SQLITE_PRAGMA               19   /* Pragma Name     1st arg or NULL */
    02309 #define SQLITE_READ                 20   /* Table Name      Column Name     */
    02310 #define SQLITE_SELECT               21   /* NULL            NULL            */
    02311 #define SQLITE_TRANSACTION          22   /* Operation       NULL            */
    02312 #define SQLITE_UPDATE               23   /* Table Name      Column Name     */
    02313 #define SQLITE_ATTACH               24   /* Filename        NULL            */
    02314 #define SQLITE_DETACH               25   /* Database Name   NULL            */
    02315 #define SQLITE_ALTER_TABLE          26   /* Database Name   Table Name      */
    02316 #define SQLITE_REINDEX              27   /* Index Name      NULL            */
    02317 #define SQLITE_ANALYZE              28   /* Table Name      NULL            */
    02318 #define SQLITE_CREATE_VTABLE        29   /* Table Name      Module Name     */
    02319 #define SQLITE_DROP_VTABLE          30   /* Table Name      Module Name     */
    02320 #define SQLITE_FUNCTION             31   /* NULL            Function Name   */
    02321 #define SQLITE_SAVEPOINT            32   /* Operation       Savepoint Name  */
    02322 #define SQLITE_COPY                  0   /* No longer used */
    02323
    02324 /*
    02325 ** CAPI3REF: Tracing And Profiling Functions
    02326 **
    02327 ** These routines register callback functions that can be used for
    02328 ** tracing and profiling the execution of SQL statements.
    02329 **
    02330 ** ^The callback function registered by sqlite3_trace() is invoked at
    02331 ** various times when an SQL statement is being run by [sqlite3_step()].
    02332 ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
    02333 ** SQL statement text as the statement first begins executing.
    02334 ** ^(Additional sqlite3_trace() callbacks might occur
    02335 ** as each triggered subprogram is entered.  The callbacks for triggers
    02336 ** contain a UTF-8 SQL comment that identifies the trigger.)^
    02337 **
    02338 ** ^The callback function registered by sqlite3_profile() is invoked
    02339 ** as each SQL statement finishes.  ^The profile callback contains
    02340 ** the original statement text and an estimate of wall-clock time
    02341 ** of how long that statement took to run.  ^The profile callback
    02342 ** time is in units of nanoseconds, however the current implementation
    02343 ** is only capable of millisecond resolution so the six least significant
    02344 ** digits in the time are meaningless.  Future versions of SQLite
    02345 ** might provide greater resolution on the profiler callback.  The
    02346 ** sqlite3_profile() function is considered experimental and is
    02347 ** subject to change in future versions of SQLite.
    02348 */
    02349 SQLITE_API void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*);
    02350 SQLITE_API SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*,
    02351    void(*xProfile)(void*,const char*,sqlite3_uint64), void*);
    02352
    02353 /*
    02354 ** CAPI3REF: Query Progress Callbacks
    02355 **
    02356 ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
    02357 ** function X to be invoked periodically during long running calls to
    02358 ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for
    02359 ** database connection D.  An example use for this
    02360 ** interface is to keep a GUI updated during a large query.
    02361 **
    02362 ** ^The parameter P is passed through as the only parameter to the
    02363 ** callback function X.  ^The parameter N is the number of
    02364 ** [virtual machine instructions] that are evaluated between successive
    02365 ** invocations of the callback X.
    02366 **
    02367 ** ^Only a single progress handler may be defined at one time per
    02368 ** [database connection]; setting a new progress handler cancels the
    02369 ** old one.  ^Setting parameter X to NULL disables the progress handler.
    02370 ** ^The progress handler is also disabled by setting N to a value less
    02371 ** than 1.
    02372 **
    02373 ** ^If the progress callback returns non-zero, the operation is
    02374 ** interrupted.  This feature can be used to implement a
    02375 ** "Cancel" button on a GUI progress dialog box.
    02376 **
    02377 ** The progress handler callback must not do anything that will modify
    02378 ** the database connection that invoked the progress handler.
    02379 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
    02380 ** database connections for the meaning of "modify" in this paragraph.
    02381 **
    02382 */
    02383 SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
    02384
    02385 /*
    02386 ** CAPI3REF: Opening A New Database Connection
    02387 **
    02388 ** ^These routines open an SQLite database file as specified by the
    02389 ** filename argument. ^The filename argument is interpreted as UTF-8 for
    02390 ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
    02391 ** order for sqlite3_open16(). ^(A [database connection] handle is usually
    02392 ** returned in *ppDb, even if an error occurs.  The only exception is that
    02393 ** if SQLite is unable to allocate memory to hold the [sqlite3] object,
    02394 ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
    02395 ** object.)^ ^(If the database is opened (and/or created) successfully, then
    02396 ** [SQLITE_OK] is returned.  Otherwise an [error code] is returned.)^ ^The
    02397 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
    02398 ** an English language description of the error following a failure of any
    02399 ** of the sqlite3_open() routines.
    02400 **
    02401 ** ^The default encoding for the database will be UTF-8 if
    02402 ** sqlite3_open() or sqlite3_open_v2() is called and
    02403 ** UTF-16 in the native byte order if sqlite3_open16() is used.
    02404 **
    02405 ** Whether or not an error occurs when it is opened, resources
    02406 ** associated with the [database connection] handle should be released by
    02407 ** passing it to [sqlite3_close()] when it is no longer required.
    02408 **
    02409 ** The sqlite3_open_v2() interface works like sqlite3_open()
    02410 ** except that it accepts two additional parameters for additional control
    02411 ** over the new database connection.  ^(The flags parameter to
    02412 ** sqlite3_open_v2() can take one of
    02413 ** the following three values, optionally combined with the
    02414 ** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE],
    02415 ** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^
    02416 **
    02417 ** <dl>
    02418 ** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
    02419 ** <dd>The database is opened in read-only mode.  If the database does not
    02420 ** already exist, an error is returned.</dd>)^
    02421 **
    02422 ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
    02423 ** <dd>The database is opened for reading and writing if possible, or reading
    02424 ** only if the file is write protected by the operating system.  In either
    02425 ** case the database must already exist, otherwise an error is returned.</dd>)^
    02426 **
    02427 ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
    02428 ** <dd>The database is opened for reading and writing, and is created if
    02429 ** it does not already exist. This is the behavior that is always used for
    02430 ** sqlite3_open() and sqlite3_open16().</dd>)^
    02431 ** </dl>
    02432 **
    02433 ** If the 3rd parameter to sqlite3_open_v2() is not one of the
    02434 ** combinations shown above optionally combined with other
    02435 ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits]
    02436 ** then the behavior is undefined.
    02437 **
    02438 ** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection
    02439 ** opens in the multi-thread [threading mode] as long as the single-thread
    02440 ** mode has not been set at compile-time or start-time.  ^If the
    02441 ** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens
    02442 ** in the serialized [threading mode] unless single-thread was
    02443 ** previously selected at compile-time or start-time.
    02444 ** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be
    02445 ** eligible to use [shared cache mode], regardless of whether or not shared
    02446 ** cache is enabled using [sqlite3_enable_shared_cache()].  ^The
    02447 ** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not
    02448 ** participate in [shared cache mode] even if it is enabled.
    02449 **
    02450 ** ^The fourth parameter to sqlite3_open_v2() is the name of the
    02451 ** [sqlite3_vfs] object that defines the operating system interface that
    02452 ** the new database connection should use.  ^If the fourth parameter is
    02453 ** a NULL pointer then the default [sqlite3_vfs] object is used.
    02454 **
    02455 ** ^If the filename is ":memory:", then a private, temporary in-memory database
    02456 ** is created for the connection.  ^This in-memory database will vanish when
    02457 ** the database connection is closed.  Future versions of SQLite might
    02458 ** make use of additional special filenames that begin with the ":" character.
    02459 ** It is recommended that when a database filename actually does begin with
    02460 ** a ":" character you should prefix the filename with a pathname such as
    02461 ** "./" to avoid ambiguity.
    02462 **
    02463 ** ^If the filename is an empty string, then a private, temporary
    02464 ** on-disk database will be created.  ^This private database will be
    02465 ** automatically deleted as soon as the database connection is closed.
    02466 **
    02467 ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3>
    02468 **
    02469 ** ^If [URI filename] interpretation is enabled, and the filename argument
    02470 ** begins with "file:", then the filename is interpreted as a URI. ^URI
    02471 ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is
    02472 ** set in the fourth argument to sqlite3_open_v2(), or if it has
    02473 ** been enabled globally using the [SQLITE_CONFIG_URI] option with the
    02474 ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option.
    02475 ** As of SQLite version 3.7.7, URI filename interpretation is turned off
    02476 ** by default, but future releases of SQLite might enable URI filename
    02477 ** interpretation by default.  See "[URI filenames]" for additional
    02478 ** information.
    02479 **
    02480 ** URI filenames are parsed according to RFC 3986. ^If the URI contains an
    02481 ** authority, then it must be either an empty string or the string
    02482 ** "localhost". ^If the authority is not an empty string or "localhost", an
    02483 ** error is returned to the caller. ^The fragment component of a URI, if
    02484 ** present, is ignored.
    02485 **
    02486 ** ^SQLite uses the path component of the URI as the name of the disk file
    02487 ** which contains the database. ^If the path begins with a '/' character,
    02488 ** then it is interpreted as an absolute path. ^If the path does not begin
    02489 ** with a '/' (meaning that the authority section is omitted from the URI)
    02490 ** then the path is interpreted as a relative path.
    02491 ** ^On windows, the first component of an absolute path
    02492 ** is a drive specification (e.g. "C:").
    02493 **
    02494 ** [[core URI query parameters]]
    02495 ** The query component of a URI may contain parameters that are interpreted
    02496 ** either by SQLite itself, or by a [VFS | custom VFS implementation].
    02497 ** SQLite interprets the following three query parameters:
    02498 **
    02499 ** <ul>
    02500 **   <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
    02501 **     a VFS object that provides the operating system interface that should
    02502 **     be used to access the database file on disk. ^If this option is set to
    02503 **     an empty string the default VFS object is used. ^Specifying an unknown
    02504 **     VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is
    02505 **     present, then the VFS specified by the option takes precedence over
    02506 **     the value passed as the fourth parameter to sqlite3_open_v2().
    02507 **
    02508 **   <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw" or
    02509 **     "rwc". Attempting to set it to any other value is an error)^.
    02510 **     ^If "ro" is specified, then the database is opened for read-only
    02511 **     access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the
    02512 **     third argument to sqlite3_prepare_v2(). ^If the mode option is set to
    02513 **     "rw", then the database is opened for read-write (but not create)
    02514 **     access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had
    02515 **     been set. ^Value "rwc" is equivalent to setting both
    02516 **     SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If sqlite3_open_v2() is
    02517 **     used, it is an error to specify a value for the mode parameter that is
    02518 **     less restrictive than that specified by the flags passed as the third
    02519 **     parameter.
    02520 **
    02521 **   <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or
    02522 **     "private". ^Setting it to "shared" is equivalent to setting the
    02523 **     SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to
    02524 **     sqlite3_open_v2(). ^Setting the cache parameter to "private" is
    02525 **     equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
    02526 **     ^If sqlite3_open_v2() is used and the "cache" parameter is present in
    02527 **     a URI filename, its value overrides any behaviour requested by setting
    02528 **     SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
    02529 ** </ul>
    02530 **
    02531 ** ^Specifying an unknown parameter in the query component of a URI is not an
    02532 ** error.  Future versions of SQLite might understand additional query
    02533 ** parameters.  See "[query parameters with special meaning to SQLite]" for
    02534 ** additional information.
    02535 **
    02536 ** [[URI filename examples]] <h3>URI filename examples</h3>
    02537 **
    02538 ** <table border="1" align=center cellpadding=5>
    02539 ** <tr><th> URI filenames <th> Results
    02540 ** <tr><td> file:data.db <td>
    02541 **          Open the file "data.db" in the current directory.
    02542 ** <tr><td> file:/home/fred/data.db<br>
    02543 **          file:///home/fred/data.db <br>
    02544 **          file://localhost/home/fred/data.db <br> <td>
    02545 **          Open the database file "/home/fred/data.db".
    02546 ** <tr><td> file://darkstar/home/fred/data.db <td>
    02547 **          An error. "darkstar" is not a recognized authority.
    02548 ** <tr><td style="white-space:nowrap">
    02549 **          file:///C:/Documents%20and%20Settings/fred/Desktop/data.db
    02550 **     <td> Windows only: Open the file "data.db" on fred's desktop on drive
    02551 **          C:. Note that the %20 escaping in this example is not strictly
    02552 **          necessary - space characters can be used literally
    02553 **          in URI filenames.
    02554 ** <tr><td> file:data.db?mode=ro&cache=private <td>
    02555 **          Open file "data.db" in the current directory for read-only access.
    02556 **          Regardless of whether or not shared-cache mode is enabled by
    02557 **          default, use a private cache.
    02558 ** <tr><td> file:/home/fred/data.db?vfs=unix-nolock <td>
    02559 **          Open file "/home/fred/data.db". Use the special VFS "unix-nolock".
    02560 ** <tr><td> file:data.db?mode=readonly <td>
    02561 **          An error. "readonly" is not a valid option for the "mode" parameter.
    02562 ** </table>
    02563 **
    02564 ** ^URI hexadecimal escape sequences (%HH) are supported within the path and
    02565 ** query components of a URI. A hexadecimal escape sequence consists of a
    02566 ** percent sign - "%" - followed by exactly two hexadecimal digits
    02567 ** specifying an octet value. ^Before the path or query components of a
    02568 ** URI filename are interpreted, they are encoded using UTF-8 and all
    02569 ** hexadecimal escape sequences replaced by a single byte containing the
    02570 ** corresponding octet. If this process generates an invalid UTF-8 encoding,
    02571 ** the results are undefined.
    02572 **
    02573 ** <b>Note to Windows users:</b>  The encoding used for the filename argument
    02574 ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
    02575 ** codepage is currently defined.  Filenames containing international
    02576 ** characters must be converted to UTF-8 prior to passing them into
    02577 ** sqlite3_open() or sqlite3_open_v2().
    02578 */
    02579 SQLITE_API int sqlite3_open(
    02580   const char *filename,   /* Database filename (UTF-8) */
    02581   sqlite3 **ppDb          /* OUT: SQLite db handle */
    02582 );
    02583 SQLITE_API int sqlite3_open16(
    02584   const void *filename,   /* Database filename (UTF-16) */
    02585   sqlite3 **ppDb          /* OUT: SQLite db handle */
    02586 );
    02587 SQLITE_API int sqlite3_open_v2(
    02588   const char *filename,   /* Database filename (UTF-8) */
    02589   sqlite3 **ppDb,         /* OUT: SQLite db handle */
    02590   int flags,              /* Flags */
    02591   const char *zVfs        /* Name of VFS module to use */
    02592 );
    02593
    02594 /*
    02595 ** CAPI3REF: Obtain Values For URI Parameters
    02596 **
    02597 ** This is a utility routine, useful to VFS implementations, that checks
    02598 ** to see if a database file was a URI that contained a specific query
    02599 ** parameter, and if so obtains the value of the query parameter.
    02600 **
    02601 ** The zFilename argument is the filename pointer passed into the xOpen()
    02602 ** method of a VFS implementation.  The zParam argument is the name of the
    02603 ** query parameter we seek.  This routine returns the value of the zParam
    02604 ** parameter if it exists.  If the parameter does not exist, this routine
    02605 ** returns a NULL pointer.
    02606 **
    02607 ** If the zFilename argument to this function is not a pointer that SQLite
    02608 ** passed into the xOpen VFS method, then the behavior of this routine
    02609 ** is undefined and probably undesirable.
    02610 */
    02611 SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam);
    02612
    02613
    02614 /*
    02615 ** CAPI3REF: Error Codes And Messages
    02616 **
    02617 ** ^The sqlite3_errcode() interface returns the numeric [result code] or
    02618 ** [extended result code] for the most recent failed sqlite3_* API call
    02619 ** associated with a [database connection]. If a prior API call failed
    02620 ** but the most recent API call succeeded, the return value from
    02621 ** sqlite3_errcode() is undefined.  ^The sqlite3_extended_errcode()
    02622 ** interface is the same except that it always returns the
    02623 ** [extended result code] even when extended result codes are
    02624 ** disabled.
    02625 **
    02626 ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
    02627 ** text that describes the error, as either UTF-8 or UTF-16 respectively.
    02628 ** ^(Memory to hold the error message string is managed internally.
    02629 ** The application does not need to worry about freeing the result.
    02630 ** However, the error string might be overwritten or deallocated by
    02631 ** subsequent calls to other SQLite interface functions.)^
    02632 **
    02633 ** When the serialized [threading mode] is in use, it might be the
    02634 ** case that a second error occurs on a separate thread in between
    02635 ** the time of the first error and the call to these interfaces.
    02636 ** When that happens, the second error will be reported since these
    02637 ** interfaces always report the most recent result.  To avoid
    02638 ** this, each thread can obtain exclusive use of the [database connection] D
    02639 ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
    02640 ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
    02641 ** all calls to the interfaces listed here are completed.
    02642 **
    02643 ** If an interface fails with SQLITE_MISUSE, that means the interface
    02644 ** was invoked incorrectly by the application.  In that case, the
    02645 ** error code and message may or may not be set.
    02646 */
    02647 SQLITE_API int sqlite3_errcode(sqlite3 *db);
    02648 SQLITE_API int sqlite3_extended_errcode(sqlite3 *db);
    02649 SQLITE_API const char *sqlite3_errmsg(sqlite3*);
    02650 SQLITE_API const void *sqlite3_errmsg16(sqlite3*);
    02651
    02652 /*
    02653 ** CAPI3REF: SQL Statement Object
    02654 ** KEYWORDS: {prepared statement} {prepared statements}
    02655 **
    02656 ** An instance of this object represents a single SQL statement.
    02657 ** This object is variously known as a "prepared statement" or a
    02658 ** "compiled SQL statement" or simply as a "statement".
    02659 **
    02660 ** The life of a statement object goes something like this:
    02661 **
    02662 ** <ol>
    02663 ** <li> Create the object using [sqlite3_prepare_v2()] or a related
    02664 **      function.
    02665 ** <li> Bind values to [host parameters] using the sqlite3_bind_*()
    02666 **      interfaces.
    02667 ** <li> Run the SQL by calling [sqlite3_step()] one or more times.
    02668 ** <li> Reset the statement using [sqlite3_reset()] then go back
    02669 **      to step 2.  Do this zero or more times.
    02670 ** <li> Destroy the object using [sqlite3_finalize()].
    02671 ** </ol>
    02672 **
    02673 ** Refer to documentation on individual methods above for additional
    02674 ** information.
    02675 */
    02676 typedef struct sqlite3_stmt sqlite3_stmt;
    02677
    02678 /*
    02679 ** CAPI3REF: Run-time Limits
    02680 **
    02681 ** ^(This interface allows the size of various constructs to be limited
    02682 ** on a connection by connection basis.  The first parameter is the
    02683 ** [database connection] whose limit is to be set or queried.  The
    02684 ** second parameter is one of the [limit categories] that define a
    02685 ** class of constructs to be size limited.  The third parameter is the
    02686 ** new limit for that construct.)^
    02687 **
    02688 ** ^If the new limit is a negative number, the limit is unchanged.
    02689 ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a
    02690 ** [limits | hard upper bound]
    02691 ** set at compile-time by a C preprocessor macro called
    02692 ** [limits | SQLITE_MAX_<i>NAME</i>].
    02693 ** (The "_LIMIT_" in the name is changed to "_MAX_".))^
    02694 ** ^Attempts to increase a limit above its hard upper bound are
    02695 ** silently truncated to the hard upper bound.
    02696 **
    02697 ** ^Regardless of whether or not the limit was changed, the
    02698 ** [sqlite3_limit()] interface returns the prior value of the limit.
    02699 ** ^Hence, to find the current value of a limit without changing it,
    02700 ** simply invoke this interface with the third parameter set to -1.
    02701 **
    02702 ** Run-time limits are intended for use in applications that manage
    02703 ** both their own internal database and also databases that are controlled
    02704 ** by untrusted external sources.  An example application might be a
    02705 ** web browser that has its own databases for storing history and
    02706 ** separate databases controlled by JavaScript applications downloaded
    02707 ** off the Internet.  The internal databases can be given the
    02708 ** large, default limits.  Databases managed by external sources can
    02709 ** be given much smaller limits designed to prevent a denial of service
    02710 ** attack.  Developers might also want to use the [sqlite3_set_authorizer()]
    02711 ** interface to further control untrusted SQL.  The size of the database
    02712 ** created by an untrusted script can be contained using the
    02713 ** [max_page_count] [PRAGMA].
    02714 **
    02715 ** New run-time limit categories may be added in future releases.
    02716 */
    02717 SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
    02718
    02719 /*
    02720 ** CAPI3REF: Run-Time Limit Categories
    02721 ** KEYWORDS: {limit category} {*limit categories}
    02722 **
    02723 ** These constants define various performance limits
    02724 ** that can be lowered at run-time using [sqlite3_limit()].
    02725 ** The synopsis of the meanings of the various limits is shown below.
    02726 ** Additional information is available at [limits | Limits in SQLite].
    02727 **
    02728 ** <dl>
    02729 ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt>
    02730 ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
    02731 **
    02732 ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
    02733 ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^
    02734 **
    02735 ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt>
    02736 ** <dd>The maximum number of columns in a table definition or in the
    02737 ** result set of a [SELECT] or the maximum number of columns in an index
    02738 ** or in an ORDER BY or GROUP BY clause.</dd>)^
    02739 **
    02740 ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
    02741 ** <dd>The maximum depth of the parse tree on any expression.</dd>)^
    02742 **
    02743 ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
    02744 ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
    02745 **
    02746 ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt>
    02747 ** <dd>The maximum number of instructions in a virtual machine program
    02748 ** used to implement an SQL statement.  This limit is not currently
    02749 ** enforced, though that might be added in some future release of
    02750 ** SQLite.</dd>)^
    02751 **
    02752 ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
    02753 ** <dd>The maximum number of arguments on a function.</dd>)^
    02754 **
    02755 ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt>
    02756 ** <dd>The maximum number of [ATTACH | attached databases].)^</dd>
    02757 **
    02758 ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]]
    02759 ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
    02760 ** <dd>The maximum length of the pattern argument to the [LIKE] or
    02761 ** [GLOB] operators.</dd>)^
    02762 **
    02763 ** [[SQLITE_LIMIT_VARIABLE_NUMBER]]
    02764 ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
    02765 ** <dd>The maximum index number of any [parameter] in an SQL statement.)^
    02766 **
    02767 ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
    02768 ** <dd>The maximum depth of recursion for triggers.</dd>)^
    02769 ** </dl>
    02770 */
    02771 #define SQLITE_LIMIT_LENGTH                    0
    02772 #define SQLITE_LIMIT_SQL_LENGTH                1
    02773 #define SQLITE_LIMIT_COLUMN                    2
    02774 #define SQLITE_LIMIT_EXPR_DEPTH                3
    02775 #define SQLITE_LIMIT_COMPOUND_SELECT           4
    02776 #define SQLITE_LIMIT_VDBE_OP                   5
    02777 #define SQLITE_LIMIT_FUNCTION_ARG              6
    02778 #define SQLITE_LIMIT_ATTACHED                  7
    02779 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH       8
    02780 #define SQLITE_LIMIT_VARIABLE_NUMBER           9
    02781 #define SQLITE_LIMIT_TRIGGER_DEPTH            10
    02782
    02783 /*
    02784 ** CAPI3REF: Compiling An SQL Statement
    02785 ** KEYWORDS: {SQL statement compiler}
    02786 **
    02787 ** To execute an SQL query, it must first be compiled into a byte-code
    02788 ** program using one of these routines.
    02789 **
    02790 ** The first argument, "db", is a [database connection] obtained from a
    02791 ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
    02792 ** [sqlite3_open16()].  The database connection must not have been closed.
    02793 **
    02794 ** The second argument, "zSql", is the statement to be compiled, encoded
    02795 ** as either UTF-8 or UTF-16.  The sqlite3_prepare() and sqlite3_prepare_v2()
    02796 ** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2()
    02797 ** use UTF-16.
    02798 **
    02799 ** ^If the nByte argument is less than zero, then zSql is read up to the
    02800 ** first zero terminator. ^If nByte is non-negative, then it is the maximum
    02801 ** number of  bytes read from zSql.  ^When nByte is non-negative, the
    02802 ** zSql string ends at either the first '\000' or '\u0000' character or
    02803 ** the nByte-th byte, whichever comes first. If the caller knows
    02804 ** that the supplied string is nul-terminated, then there is a small
    02805 ** performance advantage to be gained by passing an nByte parameter that
    02806 ** is equal to the number of bytes in the input string <i>including</i>
    02807 ** the nul-terminator bytes as this saves SQLite from having to
    02808 ** make a copy of the input string.
    02809 **
    02810 ** ^If pzTail is not NULL then *pzTail is made to point to the first byte
    02811 ** past the end of the first SQL statement in zSql.  These routines only
    02812 ** compile the first statement in zSql, so *pzTail is left pointing to
    02813 ** what remains uncompiled.
    02814 **
    02815 ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
    02816 ** executed using [sqlite3_step()].  ^If there is an error, *ppStmt is set
    02817 ** to NULL.  ^If the input text contains no SQL (if the input is an empty
    02818 ** string or a comment) then *ppStmt is set to NULL.
    02819 ** The calling procedure is responsible for deleting the compiled
    02820 ** SQL statement using [sqlite3_finalize()] after it has finished with it.
    02821 ** ppStmt may not be NULL.
    02822 **
    02823 ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
    02824 ** otherwise an [error code] is returned.
    02825 **
    02826 ** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are
    02827 ** recommended for all new programs. The two older interfaces are retained
    02828 ** for backwards compatibility, but their use is discouraged.
    02829 ** ^In the "v2" interfaces, the prepared statement
    02830 ** that is returned (the [sqlite3_stmt] object) contains a copy of the
    02831 ** original SQL text. This causes the [sqlite3_step()] interface to
    02832 ** behave differently in three ways:
    02833 **
    02834 ** <ol>
    02835 ** <li>
    02836 ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
    02837 ** always used to do, [sqlite3_step()] will automatically recompile the SQL
    02838 ** statement and try to run it again.
    02839 ** </li>
    02840 **
    02841 ** <li>
    02842 ** ^When an error occurs, [sqlite3_step()] will return one of the detailed
    02843 ** [error codes] or [extended error codes].  ^The legacy behavior was that
    02844 ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
    02845 ** and the application would have to make a second call to [sqlite3_reset()]
    02846 ** in order to find the underlying cause of the problem. With the "v2" prepare
    02847 ** interfaces, the underlying reason for the error is returned immediately.
    02848 ** </li>
    02849 **
    02850 ** <li>
    02851 ** ^If the specific value bound to [parameter | host parameter] in the
    02852 ** WHERE clause might influence the choice of query plan for a statement,
    02853 ** then the statement will be automatically recompiled, as if there had been
    02854 ** a schema change, on the first  [sqlite3_step()] call following any change
    02855 ** to the [sqlite3_bind_text | bindings] of that [parameter].
    02856 ** ^The specific value of WHERE-clause [parameter] might influence the
    02857 ** choice of query plan if the parameter is the left-hand side of a [LIKE]
    02858 ** or [GLOB] operator or if the parameter is compared to an indexed column
    02859 ** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled.
    02860 ** the
    02861 ** </li>
    02862 ** </ol>
    02863 */
    02864 SQLITE_API int sqlite3_prepare(
    02865   sqlite3 *db,            /* Database handle */
    02866   const char *zSql,       /* SQL statement, UTF-8 encoded */
    02867   int nByte,              /* Maximum length of zSql in bytes. */
    02868   sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
    02869   const char **pzTail     /* OUT: Pointer to unused portion of zSql */
    02870 );
    02871 SQLITE_API int sqlite3_prepare_v2(
    02872   sqlite3 *db,            /* Database handle */
    02873   const char *zSql,       /* SQL statement, UTF-8 encoded */
    02874   int nByte,              /* Maximum length of zSql in bytes. */
    02875   sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
    02876   const char **pzTail     /* OUT: Pointer to unused portion of zSql */
    02877 );
    02878 SQLITE_API int sqlite3_prepare16(
    02879   sqlite3 *db,            /* Database handle */
    02880   const void *zSql,       /* SQL statement, UTF-16 encoded */
    02881   int nByte,              /* Maximum length of zSql in bytes. */
    02882   sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
    02883   const void **pzTail     /* OUT: Pointer to unused portion of zSql */
    02884 );
    02885 SQLITE_API int sqlite3_prepare16_v2(
    02886   sqlite3 *db,            /* Database handle */
    02887   const void *zSql,       /* SQL statement, UTF-16 encoded */
    02888   int nByte,              /* Maximum length of zSql in bytes. */
    02889   sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
    02890   const void **pzTail     /* OUT: Pointer to unused portion of zSql */
    02891 );
    02892
    02893 /*
    02894 ** CAPI3REF: Retrieving Statement SQL
    02895 **
    02896 ** ^This interface can be used to retrieve a saved copy of the original
    02897 ** SQL text used to create a [prepared statement] if that statement was
    02898 ** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()].
    02899 */
    02900 SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt);
    02901
    02902 /*
    02903 ** CAPI3REF: Determine If An SQL Statement Writes The Database
    02904 **
    02905 ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
    02906 ** and only if the [prepared statement] X makes no direct changes to
    02907 ** the content of the database file.
    02908 **
    02909 ** Note that [application-defined SQL functions] or
    02910 ** [virtual tables] might change the database indirectly as a side effect.
    02911 ** ^(For example, if an application defines a function "eval()" that
    02912 ** calls [sqlite3_exec()], then the following SQL statement would
    02913 ** change the database file through side-effects:
    02914 **
    02915 ** <blockquote><pre>
    02916 **    SELECT eval('DELETE FROM t1') FROM t2;
    02917 ** </pre></blockquote>
    02918 **
    02919 ** But because the [SELECT] statement does not change the database file
    02920 ** directly, sqlite3_stmt_readonly() would still return true.)^
    02921 **
    02922 ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
    02923 ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
    02924 ** since the statements themselves do not actually modify the database but
    02925 ** rather they control the timing of when other statements modify the
    02926 ** database.  ^The [ATTACH] and [DETACH] statements also cause
    02927 ** sqlite3_stmt_readonly() to return true since, while those statements
    02928 ** change the configuration of a database connection, they do not make
    02929 ** changes to the content of the database files on disk.
    02930 */
    02931 SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
    02932
    02933 /*
    02934 ** CAPI3REF: Dynamically Typed Value Object
    02935 ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
    02936 **
    02937 ** SQLite uses the sqlite3_value object to represent all values
    02938 ** that can be stored in a database table. SQLite uses dynamic typing
    02939 ** for the values it stores.  ^Values stored in sqlite3_value objects
    02940 ** can be integers, floating point values, strings, BLOBs, or NULL.
    02941 **
    02942 ** An sqlite3_value object may be either "protected" or "unprotected".
    02943 ** Some interfaces require a protected sqlite3_value.  Other interfaces
    02944 ** will accept either a protected or an unprotected sqlite3_value.
    02945 ** Every interface that accepts sqlite3_value arguments specifies
    02946 ** whether or not it requires a protected sqlite3_value.
    02947 **
    02948 ** The terms "protected" and "unprotected" refer to whether or not
    02949 ** a mutex is held.  An internal mutex is held for a protected
    02950 ** sqlite3_value object but no mutex is held for an unprotected
    02951 ** sqlite3_value object.  If SQLite is compiled to be single-threaded
    02952 ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
    02953 ** or if SQLite is run in one of reduced mutex modes
    02954 ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
    02955 ** then there is no distinction between protected and unprotected
    02956 ** sqlite3_value objects and they can be used interchangeably.  However,
    02957 ** for maximum code portability it is recommended that applications
    02958 ** still make the distinction between protected and unprotected
    02959 ** sqlite3_value objects even when not strictly required.
    02960 **
    02961 ** ^The sqlite3_value objects that are passed as parameters into the
    02962 ** implementation of [application-defined SQL functions] are protected.
    02963 ** ^The sqlite3_value object returned by
    02964 ** [sqlite3_column_value()] is unprotected.
    02965 ** Unprotected sqlite3_value objects may only be used with
    02966 ** [sqlite3_result_value()] and [sqlite3_bind_value()].
    02967 ** The [sqlite3_value_blob | sqlite3_value_type()] family of
    02968 ** interfaces require protected sqlite3_value objects.
    02969 */
    02970 typedef struct Mem sqlite3_value;
    02971
    02972 /*
    02973 ** CAPI3REF: SQL Function Context Object
    02974 **
    02975 ** The context in which an SQL function executes is stored in an
    02976 ** sqlite3_context object.  ^A pointer to an sqlite3_context object
    02977 ** is always first parameter to [application-defined SQL functions].
    02978 ** The application-defined SQL function implementation will pass this
    02979 ** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
    02980 ** [sqlite3_aggregate_context()], [sqlite3_user_data()],
    02981 ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
    02982 ** and/or [sqlite3_set_auxdata()].
    02983 */
    02984 typedef struct sqlite3_context sqlite3_context;
    02985
    02986 /*
    02987 ** CAPI3REF: Binding Values To Prepared Statements
    02988 ** KEYWORDS: {host parameter} {host parameters} {host parameter name}
    02989 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
    02990 **
    02991 ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
    02992 ** literals may be replaced by a [parameter] that matches one of following
    02993 ** templates:
    02994 **
    02995 ** <ul>
    02996 ** <li>  ?
    02997 ** <li>  ?NNN
    02998 ** <li>  :VVV
    02999 ** <li>  @VVV
    03000 ** <li>  $VVV
    03001 ** </ul>
    03002 **
    03003 ** In the templates above, NNN represents an integer literal,
    03004 ** and VVV represents an alphanumeric identifier.)^  ^The values of these
    03005 ** parameters (also called "host parameter names" or "SQL parameters")
    03006 ** can be set using the sqlite3_bind_*() routines defined here.
    03007 **
    03008 ** ^The first argument to the sqlite3_bind_*() routines is always
    03009 ** a pointer to the [sqlite3_stmt] object returned from
    03010 ** [sqlite3_prepare_v2()] or its variants.
    03011 **
    03012 ** ^The second argument is the index of the SQL parameter to be set.
    03013 ** ^The leftmost SQL parameter has an index of 1.  ^When the same named
    03014 ** SQL parameter is used more than once, second and subsequent
    03015 ** occurrences have the same index as the first occurrence.
    03016 ** ^The index for named parameters can be looked up using the
    03017 ** [sqlite3_bind_parameter_index()] API if desired.  ^The index
    03018 ** for "?NNN" parameters is the value of NNN.
    03019 ** ^The NNN value must be between 1 and the [sqlite3_limit()]
    03020 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999).
    03021 **
    03022 ** ^The third argument is the value to bind to the parameter.
    03023 **
    03024 ** ^(In those routines that have a fourth argument, its value is the
    03025 ** number of bytes in the parameter.  To be clear: the value is the
    03026 ** number of <u>bytes</u> in the value, not the number of characters.)^
    03027 ** ^If the fourth parameter is negative, the length of the string is
    03028 ** the number of bytes up to the first zero terminator.
    03029 ** If a non-negative fourth parameter is provided to sqlite3_bind_text()
    03030 ** or sqlite3_bind_text16() then that parameter must be the byte offset
    03031 ** where the NUL terminator would occur assuming the string were NUL
    03032 ** terminated.  If any NUL characters occur at byte offsets less than
    03033 ** the value of the fourth parameter then the resulting string value will
    03034 ** contain embedded NULs.  The result of expressions involving strings
    03035 ** with embedded NULs is undefined.
    03036 **
    03037 ** ^The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and
    03038 ** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or
    03039 ** string after SQLite has finished with it.  ^The destructor is called
    03040 ** to dispose of the BLOB or string even if the call to sqlite3_bind_blob(),
    03041 ** sqlite3_bind_text(), or sqlite3_bind_text16() fails.
    03042 ** ^If the fifth argument is
    03043 ** the special value [SQLITE_STATIC], then SQLite assumes that the
    03044 ** information is in static, unmanaged space and does not need to be freed.
    03045 ** ^If the fifth argument has the value [SQLITE_TRANSIENT], then
    03046 ** SQLite makes its own private copy of the data immediately, before
    03047 ** the sqlite3_bind_*() routine returns.
    03048 **
    03049 ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
    03050 ** is filled with zeroes.  ^A zeroblob uses a fixed amount of memory
    03051 ** (just an integer to hold its size) while it is being processed.
    03052 ** Zeroblobs are intended to serve as placeholders for BLOBs whose
    03053 ** content is later written using
    03054 ** [sqlite3_blob_open | incremental BLOB I/O] routines.
    03055 ** ^A negative value for the zeroblob results in a zero-length BLOB.
    03056 **
    03057 ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
    03058 ** for the [prepared statement] or with a prepared statement for which
    03059 ** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
    03060 ** then the call will return [SQLITE_MISUSE].  If any sqlite3_bind_()
    03061 ** routine is passed a [prepared statement] that has been finalized, the
    03062 ** result is undefined and probably harmful.
    03063 **
    03064 ** ^Bindings are not cleared by the [sqlite3_reset()] routine.
    03065 ** ^Unbound parameters are interpreted as NULL.
    03066 **
    03067 ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
    03068 ** [error code] if anything goes wrong.
    03069 ** ^[SQLITE_RANGE] is returned if the parameter
    03070 ** index is out of range.  ^[SQLITE_NOMEM] is returned if malloc() fails.
    03071 **
    03072 ** See also: [sqlite3_bind_parameter_count()],
    03073 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
    03074 */
    03075 SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
    03076 SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double);
    03077 SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int);
    03078 SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
    03079 SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int);
    03080 SQLITE_API int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*));
    03081 SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
    03082 SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
    03083 SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
    03084
    03085 /*
    03086 ** CAPI3REF: Number Of SQL Parameters
    03087 **
    03088 ** ^This routine can be used to find the number of [SQL parameters]
    03089 ** in a [prepared statement].  SQL parameters are tokens of the
    03090 ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
    03091 ** placeholders for values that are [sqlite3_bind_blob | bound]
    03092 ** to the parameters at a later time.
    03093 **
    03094 ** ^(This routine actually returns the index of the largest (rightmost)
    03095 ** parameter. For all forms except ?NNN, this will correspond to the
    03096 ** number of unique parameters.  If parameters of the ?NNN form are used,
    03097 ** there may be gaps in the list.)^
    03098 **
    03099 ** See also: [sqlite3_bind_blob|sqlite3_bind()],
    03100 ** [sqlite3_bind_parameter_name()], and
    03101 ** [sqlite3_bind_parameter_index()].
    03102 */
    03103 SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*);
    03104
    03105 /*
    03106 ** CAPI3REF: Name Of A Host Parameter
    03107 **
    03108 ** ^The sqlite3_bind_parameter_name(P,N) interface returns
    03109 ** the name of the N-th [SQL parameter] in the [prepared statement] P.
    03110 ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
    03111 ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
    03112 ** respectively.
    03113 ** In other words, the initial ":" or "$" or "@" or "?"
    03114 ** is included as part of the name.)^
    03115 ** ^Parameters of the form "?" without a following integer have no name
    03116 ** and are referred to as "nameless" or "anonymous parameters".
    03117 **
    03118 ** ^The first host parameter has an index of 1, not 0.
    03119 **
    03120 ** ^If the value N is out of range or if the N-th parameter is
    03121 ** nameless, then NULL is returned.  ^The returned string is
    03122 ** always in UTF-8 encoding even if the named parameter was
    03123 ** originally specified as UTF-16 in [sqlite3_prepare16()] or
    03124 ** [sqlite3_prepare16_v2()].
    03125 **
    03126 ** See also: [sqlite3_bind_blob|sqlite3_bind()],
    03127 ** [sqlite3_bind_parameter_count()], and
    03128 ** [sqlite3_bind_parameter_index()].
    03129 */
    03130 SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
    03131
    03132 /*
    03133 ** CAPI3REF: Index Of A Parameter With A Given Name
    03134 **
    03135 ** ^Return the index of an SQL parameter given its name.  ^The
    03136 ** index value returned is suitable for use as the second
    03137 ** parameter to [sqlite3_bind_blob|sqlite3_bind()].  ^A zero
    03138 ** is returned if no matching parameter is found.  ^The parameter
    03139 ** name must be given in UTF-8 even if the original statement
    03140 ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()].
    03141 **
    03142 ** See also: [sqlite3_bind_blob|sqlite3_bind()],
    03143 ** [sqlite3_bind_parameter_count()], and
    03144 ** [sqlite3_bind_parameter_index()].
    03145 */
    03146 SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
    03147
    03148 /*
    03149 ** CAPI3REF: Reset All Bindings On A Prepared Statement
    03150 **
    03151 ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
    03152 ** the [sqlite3_bind_blob | bindings] on a [prepared statement].
    03153 ** ^Use this routine to reset all host parameters to NULL.
    03154 */
    03155 SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*);
    03156
    03157 /*
    03158 ** CAPI3REF: Number Of Columns In A Result Set
    03159 **
    03160 ** ^Return the number of columns in the result set returned by the
    03161 ** [prepared statement]. ^This routine returns 0 if pStmt is an SQL
    03162 ** statement that does not return data (for example an [UPDATE]).
    03163 **
    03164 ** See also: [sqlite3_data_count()]
    03165 */
    03166 SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt);
    03167
    03168 /*
    03169 ** CAPI3REF: Column Names In A Result Set
    03170 **
    03171 ** ^These routines return the name assigned to a particular column
    03172 ** in the result set of a [SELECT] statement.  ^The sqlite3_column_name()
    03173 ** interface returns a pointer to a zero-terminated UTF-8 string
    03174 ** and sqlite3_column_name16() returns a pointer to a zero-terminated
    03175 ** UTF-16 string.  ^The first parameter is the [prepared statement]
    03176 ** that implements the [SELECT] statement. ^The second parameter is the
    03177 ** column number.  ^The leftmost column is number 0.
    03178 **
    03179 ** ^The returned string pointer is valid until either the [prepared statement]
    03180 ** is destroyed by [sqlite3_finalize()] or until the statement is automatically
    03181 ** reprepared by the first call to [sqlite3_step()] for a particular run
    03182 ** or until the next call to
    03183 ** sqlite3_column_name() or sqlite3_column_name16() on the same column.
    03184 **
    03185 ** ^If sqlite3_malloc() fails during the processing of either routine
    03186 ** (for example during a conversion from UTF-8 to UTF-16) then a
    03187 ** NULL pointer is returned.
    03188 **
    03189 ** ^The name of a result column is the value of the "AS" clause for
    03190 ** that column, if there is an AS clause.  If there is no AS clause
    03191 ** then the name of the column is unspecified and may change from
    03192 ** one release of SQLite to the next.
    03193 */
    03194 SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N);
    03195 SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N);
    03196
    03197 /*
    03198 ** CAPI3REF: Source Of Data In A Query Result
    03199 **
    03200 ** ^These routines provide a means to determine the database, table, and
    03201 ** table column that is the origin of a particular result column in
    03202 ** [SELECT] statement.
    03203 ** ^The name of the database or table or column can be returned as
    03204 ** either a UTF-8 or UTF-16 string.  ^The _database_ routines return
    03205 ** the database name, the _table_ routines return the table name, and
    03206 ** the origin_ routines return the column name.
    03207 ** ^The returned string is valid until the [prepared statement] is destroyed
    03208 ** using [sqlite3_finalize()] or until the statement is automatically
    03209 ** reprepared by the first call to [sqlite3_step()] for a particular run
    03210 ** or until the same information is requested
    03211 ** again in a different encoding.
    03212 **
    03213 ** ^The names returned are the original un-aliased names of the
    03214 ** database, table, and column.
    03215 **
    03216 ** ^The first argument to these interfaces is a [prepared statement].
    03217 ** ^These functions return information about the Nth result column returned by
    03218 ** the statement, where N is the second function argument.
    03219 ** ^The left-most column is column 0 for these routines.
    03220 **
    03221 ** ^If the Nth column returned by the statement is an expression or
    03222 ** subquery and is not a column value, then all of these functions return
    03223 ** NULL.  ^These routine might also return NULL if a memory allocation error
    03224 ** occurs.  ^Otherwise, they return the name of the attached database, table,
    03225 ** or column that query result column was extracted from.
    03226 **
    03227 ** ^As with all other SQLite APIs, those whose names end with "16" return
    03228 ** UTF-16 encoded strings and the other functions return UTF-8.
    03229 **
    03230 ** ^These APIs are only available if the library was compiled with the
    03231 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol.
    03232 **
    03233 ** If two or more threads call one or more of these routines against the same
    03234 ** prepared statement and column at the same time then the results are
    03235 ** undefined.
    03236 **
    03237 ** If two or more threads call one or more
    03238 ** [sqlite3_column_database_name | column metadata interfaces]
    03239 ** for the same [prepared statement] and result column
    03240 ** at the same time then the results are undefined.
    03241 */
    03242 SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int);
    03243 SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
    03244 SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int);
    03245 SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
    03246 SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
    03247 SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
    03248
    03249 /*
    03250 ** CAPI3REF: Declared Datatype Of A Query Result
    03251 **
    03252 ** ^(The first parameter is a [prepared statement].
    03253 ** If this statement is a [SELECT] statement and the Nth column of the
    03254 ** returned result set of that [SELECT] is a table column (not an
    03255 ** expression or subquery) then the declared type of the table
    03256 ** column is returned.)^  ^If the Nth column of the result set is an
    03257 ** expression or subquery, then a NULL pointer is returned.
    03258 ** ^The returned string is always UTF-8 encoded.
    03259 **
    03260 ** ^(For example, given the database schema:
    03261 **
    03262 ** CREATE TABLE t1(c1 VARIANT);
    03263 **
    03264 ** and the following statement to be compiled:
    03265 **
    03266 ** SELECT c1 + 1, c1 FROM t1;
    03267 **
    03268 ** this routine would return the string "VARIANT" for the second result
    03269 ** column (i==1), and a NULL pointer for the first result column (i==0).)^
    03270 **
    03271 ** ^SQLite uses dynamic run-time typing.  ^So just because a column
    03272 ** is declared to contain a particular type does not mean that the
    03273 ** data stored in that column is of the declared type.  SQLite is
    03274 ** strongly typed, but the typing is dynamic not static.  ^Type
    03275 ** is associated with individual values, not with the containers
    03276 ** used to hold those values.
    03277 */
    03278 SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int);
    03279 SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
    03280
    03281 /*
    03282 ** CAPI3REF: Evaluate An SQL Statement
    03283 **
    03284 ** After a [prepared statement] has been prepared using either
    03285 ** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy
    03286 ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
    03287 ** must be called one or more times to evaluate the statement.
    03288 **
    03289 ** The details of the behavior of the sqlite3_step() interface depend
    03290 ** on whether the statement was prepared using the newer "v2" interface
    03291 ** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy
    03292 ** interface [sqlite3_prepare()] and [sqlite3_prepare16()].  The use of the
    03293 ** new "v2" interface is recommended for new applications but the legacy
    03294 ** interface will continue to be supported.
    03295 **
    03296 ** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
    03297 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
    03298 ** ^With the "v2" interface, any of the other [result codes] or
    03299 ** [extended result codes] might be returned as well.
    03300 **
    03301 ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the
    03302 ** database locks it needs to do its job.  ^If the statement is a [COMMIT]
    03303 ** or occurs outside of an explicit transaction, then you can retry the
    03304 ** statement.  If the statement is not a [COMMIT] and occurs within an
    03305 ** explicit transaction then you should rollback the transaction before
    03306 ** continuing.
    03307 **
    03308 ** ^[SQLITE_DONE] means that the statement has finished executing
    03309 ** successfully.  sqlite3_step() should not be called again on this virtual
    03310 ** machine without first calling [sqlite3_reset()] to reset the virtual
    03311 ** machine back to its initial state.
    03312 **
    03313 ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]
    03314 ** is returned each time a new row of data is ready for processing by the
    03315 ** caller. The values may be accessed using the [column access functions].
    03316 ** sqlite3_step() is called again to retrieve the next row of data.
    03317 **
    03318 ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint
    03319 ** violation) has occurred.  sqlite3_step() should not be called again on
    03320 ** the VM. More information may be found by calling [sqlite3_errmsg()].
    03321 ** ^With the legacy interface, a more specific error code (for example,
    03322 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
    03323 ** can be obtained by calling [sqlite3_reset()] on the
    03324 ** [prepared statement].  ^In the "v2" interface,
    03325 ** the more specific error code is returned directly by sqlite3_step().
    03326 **
    03327 ** [SQLITE_MISUSE] means that the this routine was called inappropriately.
    03328 ** Perhaps it was called on a [prepared statement] that has
    03329 ** already been [sqlite3_finalize | finalized] or on one that had
    03330 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE].  Or it could
    03331 ** be the case that the same database connection is being used by two or
    03332 ** more threads at the same moment in time.
    03333 **
    03334 ** For all versions of SQLite up to and including 3.6.23.1, a call to
    03335 ** [sqlite3_reset()] was required after sqlite3_step() returned anything
    03336 ** other than [SQLITE_ROW] before any subsequent invocation of
    03337 ** sqlite3_step().  Failure to reset the prepared statement using
    03338 ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from
    03339 ** sqlite3_step().  But after version 3.6.23.1, sqlite3_step() began
    03340 ** calling [sqlite3_reset()] automatically in this circumstance rather
    03341 ** than returning [SQLITE_MISUSE].  This is not considered a compatibility
    03342 ** break because any application that ever receives an SQLITE_MISUSE error
    03343 ** is broken by definition.  The [SQLITE_OMIT_AUTORESET] compile-time option
    03344 ** can be used to restore the legacy behavior.
    03345 **
    03346 ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
    03347 ** API always returns a generic error code, [SQLITE_ERROR], following any
    03348 ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE].  You must call
    03349 ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
    03350 ** specific [error codes] that better describes the error.
    03351 ** We admit that this is a goofy design.  The problem has been fixed
    03352 ** with the "v2" interface.  If you prepare all of your SQL statements
    03353 ** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead
    03354 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
    03355 ** then the more specific [error codes] are returned directly
    03356 ** by sqlite3_step().  The use of the "v2" interface is recommended.
    03357 */
    03358 SQLITE_API int sqlite3_step(sqlite3_stmt*);
    03359
    03360 /*
    03361 ** CAPI3REF: Number of columns in a result set
    03362 **
    03363 ** ^The sqlite3_data_count(P) interface returns the number of columns in the
    03364 ** current row of the result set of [prepared statement] P.
    03365 ** ^If prepared statement P does not have results ready to return
    03366 ** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of
    03367 ** interfaces) then sqlite3_data_count(P) returns 0.
    03368 ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer.
    03369 ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to
    03370 ** [sqlite3_step](P) returned [SQLITE_DONE].  ^The sqlite3_data_count(P)
    03371 ** will return non-zero if previous call to [sqlite3_step](P) returned
    03372 ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum]
    03373 ** where it always returns zero since each step of that multi-step
    03374 ** pragma returns 0 columns of data.
    03375 **
    03376 ** See also: [sqlite3_column_count()]
    03377 */
    03378 SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
    03379
    03380 /*
    03381 ** CAPI3REF: Fundamental Datatypes
    03382 ** KEYWORDS: SQLITE_TEXT
    03383 **
    03384 ** ^(Every value in SQLite has one of five fundamental datatypes:
    03385 **
    03386 ** <ul>
    03387 ** <li> 64-bit signed integer
    03388 ** <li> 64-bit IEEE floating point number
    03389 ** <li> string
    03390 ** <li> BLOB
    03391 ** <li> NULL
    03392 ** </ul>)^
    03393 **
    03394 ** These constants are codes for each of those types.
    03395 **
    03396 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2
    03397 ** for a completely different meaning.  Software that links against both
    03398 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
    03399 ** SQLITE_TEXT.
    03400 */
    03401 #define SQLITE_INTEGER  1
    03402 #define SQLITE_FLOAT    2
    03403 #define SQLITE_BLOB     4
    03404 #define SQLITE_NULL     5
    03405 #ifdef SQLITE_TEXT
    03406 # undef SQLITE_TEXT
    03407 #else
    03408 # define SQLITE_TEXT     3
    03409 #endif
    03410 #define SQLITE3_TEXT     3
    03411
    03412 /*
    03413 ** CAPI3REF: Result Values From A Query
    03414 ** KEYWORDS: {column access functions}
    03415 **
    03416 ** These routines form the "result set" interface.
    03417 **
    03418 ** ^These routines return information about a single column of the current
    03419 ** result row of a query.  ^In every case the first argument is a pointer
    03420 ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
    03421 ** that was returned from [sqlite3_prepare_v2()] or one of its variants)
    03422 ** and the second argument is the index of the column for which information
    03423 ** should be returned. ^The leftmost column of the result set has the index 0.
    03424 ** ^The number of columns in the result can be determined using
    03425 ** [sqlite3_column_count()].
    03426 **
    03427 ** If the SQL statement does not currently point to a valid row, or if the
    03428 ** column index is out of range, the result is undefined.
    03429 ** These routines may only be called when the most recent call to
    03430 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither
    03431 ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
    03432 ** If any of these routines are called after [sqlite3_reset()] or
    03433 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned
    03434 ** something other than [SQLITE_ROW], the results are undefined.
    03435 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
    03436 ** are called from a different thread while any of these routines
    03437 ** are pending, then the results are undefined.
    03438 **
    03439 ** ^The sqlite3_column_type() routine returns the
    03440 ** [SQLITE_INTEGER | datatype code] for the initial data type
    03441 ** of the result column.  ^The returned value is one of [SQLITE_INTEGER],
    03442 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].  The value
    03443 ** returned by sqlite3_column_type() is only meaningful if no type
    03444 ** conversions have occurred as described below.  After a type conversion,
    03445 ** the value returned by sqlite3_column_type() is undefined.  Future
    03446 ** versions of SQLite may change the behavior of sqlite3_column_type()
    03447 ** following a type conversion.
    03448 **
    03449 ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
    03450 ** routine returns the number of bytes in that BLOB or string.
    03451 ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
    03452 ** the string to UTF-8 and then returns the number of bytes.
    03453 ** ^If the result is a numeric value then sqlite3_column_bytes() uses
    03454 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
    03455 ** the number of bytes in that string.
    03456 ** ^If the result is NULL, then sqlite3_column_bytes() returns zero.
    03457 **
    03458 ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16()
    03459 ** routine returns the number of bytes in that BLOB or string.
    03460 ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts
    03461 ** the string to UTF-16 and then returns the number of bytes.
    03462 ** ^If the result is a numeric value then sqlite3_column_bytes16() uses
    03463 ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns
    03464 ** the number of bytes in that string.
    03465 ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero.
    03466 **
    03467 ** ^The values returned by [sqlite3_column_bytes()] and
    03468 ** [sqlite3_column_bytes16()] do not include the zero terminators at the end
    03469 ** of the string.  ^For clarity: the values returned by
    03470 ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of
    03471 ** bytes in the string, not the number of characters.
    03472 **
    03473 ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
    03474 ** even empty strings, are always zero terminated.  ^The return
    03475 ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.
    03476 **
    03477 ** ^The object returned by [sqlite3_column_value()] is an
    03478 ** [unprotected sqlite3_value] object.  An unprotected sqlite3_value object
    03479 ** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()].
    03480 ** If the [unprotected sqlite3_value] object returned by
    03481 ** [sqlite3_column_value()] is used in any other way, including calls
    03482 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
    03483 ** or [sqlite3_value_bytes()], then the behavior is undefined.
    03484 **
    03485 ** These routines attempt to convert the value where appropriate.  ^For
    03486 ** example, if the internal representation is FLOAT and a text result
    03487 ** is requested, [sqlite3_snprintf()] is used internally to perform the
    03488 ** conversion automatically.  ^(The following table details the conversions
    03489 ** that are applied:
    03490 **
    03491 ** <blockquote>
    03492 ** <table border="1">
    03493 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th>  Conversion
    03494 **
    03495 ** <tr><td>  NULL    <td> INTEGER   <td> Result is 0
    03496 ** <tr><td>  NULL    <td>  FLOAT    <td> Result is 0.0
    03497 ** <tr><td>  NULL    <td>   TEXT    <td> Result is NULL pointer
    03498 ** <tr><td>  NULL    <td>   BLOB    <td> Result is NULL pointer
    03499 ** <tr><td> INTEGER  <td>  FLOAT    <td> Convert from integer to float
    03500 ** <tr><td> INTEGER  <td>   TEXT    <td> ASCII rendering of the integer
    03501 ** <tr><td> INTEGER  <td>   BLOB    <td> Same as INTEGER->TEXT
    03502 ** <tr><td>  FLOAT   <td> INTEGER   <td> Convert from float to integer
    03503 ** <tr><td>  FLOAT   <td>   TEXT    <td> ASCII rendering of the float
    03504 ** <tr><td>  FLOAT   <td>   BLOB    <td> Same as FLOAT->TEXT
    03505 ** <tr><td>  TEXT    <td> INTEGER   <td> Use atoi()
    03506 ** <tr><td>  TEXT    <td>  FLOAT    <td> Use atof()
    03507 ** <tr><td>  TEXT    <td>   BLOB    <td> No change
    03508 ** <tr><td>  BLOB    <td> INTEGER   <td> Convert to TEXT then use atoi()
    03509 ** <tr><td>  BLOB    <td>  FLOAT    <td> Convert to TEXT then use atof()
    03510 ** <tr><td>  BLOB    <td>   TEXT    <td> Add a zero terminator if needed
    03511 ** </table>
    03512 ** </blockquote>)^
    03513 **
    03514 ** The table above makes reference to standard C library functions atoi()
    03515 ** and atof().  SQLite does not really use these functions.  It has its
    03516 ** own equivalent internal routines.  The atoi() and atof() names are
    03517 ** used in the table for brevity and because they are familiar to most
    03518 ** C programmers.
    03519 **
    03520 ** Note that when type conversions occur, pointers returned by prior
    03521 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
    03522 ** sqlite3_column_text16() may be invalidated.
    03523 ** Type conversions and pointer invalidations might occur
    03524 ** in the following cases:
    03525 **
    03526 ** <ul>
    03527 ** <li> The initial content is a BLOB and sqlite3_column_text() or
    03528 **      sqlite3_column_text16() is called.  A zero-terminator might
    03529 **      need to be added to the string.</li>
    03530 ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
    03531 **      sqlite3_column_text16() is called.  The content must be converted
    03532 **      to UTF-16.</li>
    03533 ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
    03534 **      sqlite3_column_text() is called.  The content must be converted
    03535 **      to UTF-8.</li>
    03536 ** </ul>
    03537 **
    03538 ** ^Conversions between UTF-16be and UTF-16le are always done in place and do
    03539 ** not invalidate a prior pointer, though of course the content of the buffer
    03540 ** that the prior pointer references will have been modified.  Other kinds
    03541 ** of conversion are done in place when it is possible, but sometimes they
    03542 ** are not possible and in those cases prior pointers are invalidated.
    03543 **
    03544 ** The safest and easiest to remember policy is to invoke these routines
    03545 ** in one of the following ways:
    03546 **
    03547 ** <ul>
    03548 **  <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
    03549 **  <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
    03550 **  <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
    03551 ** </ul>
    03552 **
    03553 ** In other words, you should call sqlite3_column_text(),
    03554 ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
    03555 ** into the desired format, then invoke sqlite3_column_bytes() or
    03556 ** sqlite3_column_bytes16() to find the size of the result.  Do not mix calls
    03557 ** to sqlite3_column_text() or sqlite3_column_blob() with calls to
    03558 ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
    03559 ** with calls to sqlite3_column_bytes().
    03560 **
    03561 ** ^The pointers returned are valid until a type conversion occurs as
    03562 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
    03563 ** [sqlite3_finalize()] is called.  ^The memory space used to hold strings
    03564 ** and BLOBs is freed automatically.  Do <b>not</b> pass the pointers returned
    03565 ** [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
    03566 ** [sqlite3_free()].
    03567 **
    03568 ** ^(If a memory allocation error occurs during the evaluation of any
    03569 ** of these routines, a default value is returned.  The default value
    03570 ** is either the integer 0, the floating point number 0.0, or a NULL
    03571 ** pointer.  Subsequent calls to [sqlite3_errcode()] will return
    03572 ** [SQLITE_NOMEM].)^
    03573 */
    03574 SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
    03575 SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
    03576 SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
    03577 SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol);
    03578 SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol);
    03579 SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
    03580 SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
    03581 SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
    03582 SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol);
    03583 SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
    03584
    03585 /*
    03586 ** CAPI3REF: Destroy A Prepared Statement Object
    03587 **
    03588 ** ^The sqlite3_finalize() function is called to delete a [prepared statement].
    03589 ** ^If the most recent evaluation of the statement encountered no errors
    03590 ** or if the statement is never been evaluated, then sqlite3_finalize() returns
    03591 ** SQLITE_OK.  ^If the most recent evaluation of statement S failed, then
    03592 ** sqlite3_finalize(S) returns the appropriate [error code] or
    03593 ** [extended error code].
    03594 **
    03595 ** ^The sqlite3_finalize(S) routine can be called at any point during
    03596 ** the life cycle of [prepared statement] S:
    03597 ** before statement S is ever evaluated, after
    03598 ** one or more calls to [sqlite3_reset()], or after any call
    03599 ** to [sqlite3_step()] regardless of whether or not the statement has
    03600 ** completed execution.
    03601 **
    03602 ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op.
    03603 **
    03604 ** The application must finalize every [prepared statement] in order to avoid
    03605 ** resource leaks.  It is a grievous error for the application to try to use
    03606 ** a prepared statement after it has been finalized.  Any use of a prepared
    03607 ** statement after it has been finalized can result in undefined and
    03608 ** undesirable behavior such as segfaults and heap corruption.
    03609 */
    03610 SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt);
    03611
    03612 /*
    03613 ** CAPI3REF: Reset A Prepared Statement Object
    03614 **
    03615 ** The sqlite3_reset() function is called to reset a [prepared statement]
    03616 ** object back to its initial state, ready to be re-executed.
    03617 ** ^Any SQL statement variables that had values bound to them using
    03618 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
    03619 ** Use [sqlite3_clear_bindings()] to reset the bindings.
    03620 **
    03621 ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S
    03622 ** back to the beginning of its program.
    03623 **
    03624 ** ^If the most recent call to [sqlite3_step(S)] for the
    03625 ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE],
    03626 ** or if [sqlite3_step(S)] has never before been called on S,
    03627 ** then [sqlite3_reset(S)] returns [SQLITE_OK].
    03628 **
    03629 ** ^If the most recent call to [sqlite3_step(S)] for the
    03630 ** [prepared statement] S indicated an error, then
    03631 ** [sqlite3_reset(S)] returns an appropriate [error code].
    03632 **
    03633 ** ^The [sqlite3_reset(S)] interface does not change the values
    03634 ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
    03635 */
    03636 SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt);
    03637
    03638 /*
    03639 ** CAPI3REF: Create Or Redefine SQL Functions
    03640 ** KEYWORDS: {function creation routines}
    03641 ** KEYWORDS: {application-defined SQL function}
    03642 ** KEYWORDS: {application-defined SQL functions}
    03643 **
    03644 ** ^These functions (collectively known as "function creation routines")
    03645 ** are used to add SQL functions or aggregates or to redefine the behavior
    03646 ** of existing SQL functions or aggregates.  The only differences between
    03647 ** these routines are the text encoding expected for
    03648 ** the second parameter (the name of the function being created)
    03649 ** and the presence or absence of a destructor callback for
    03650 ** the application data pointer.
    03651 **
    03652 ** ^The first parameter is the [database connection] to which the SQL
    03653 ** function is to be added.  ^If an application uses more than one database
    03654 ** connection then application-defined SQL functions must be added
    03655 ** to each database connection separately.
    03656 **
    03657 ** ^The second parameter is the name of the SQL function to be created or
    03658 ** redefined.  ^The length of the name is limited to 255 bytes in a UTF-8
    03659 ** representation, exclusive of the zero-terminator.  ^Note that the name
    03660 ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes.
    03661 ** ^Any attempt to create a function with a longer name
    03662 ** will result in [SQLITE_MISUSE] being returned.
    03663 **
    03664 ** ^The third parameter (nArg)
    03665 ** is the number of arguments that the SQL function or
    03666 ** aggregate takes. ^If this parameter is -1, then the SQL function or
    03667 ** aggregate may take any number of arguments between 0 and the limit
    03668 ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]).  If the third
    03669 ** parameter is less than -1 or greater than 127 then the behavior is
    03670 ** undefined.
    03671 **
    03672 ** ^The fourth parameter, eTextRep, specifies what
    03673 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for
    03674 ** its parameters.  Every SQL function implementation must be able to work
    03675 ** with UTF-8, UTF-16le, or UTF-16be.  But some implementations may be
    03676 ** more efficient with one encoding than another.  ^An application may
    03677 ** invoke sqlite3_create_function() or sqlite3_create_function16() multiple
    03678 ** times with the same function but with different values of eTextRep.
    03679 ** ^When multiple implementations of the same function are available, SQLite
    03680 ** will pick the one that involves the least amount of data conversion.
    03681 ** If there is only a single implementation which does not care what text
    03682 ** encoding is used, then the fourth argument should be [SQLITE_ANY].
    03683 **
    03684 ** ^(The fifth parameter is an arbitrary pointer.  The implementation of the
    03685 ** function can gain access to this pointer using [sqlite3_user_data()].)^
    03686 **
    03687 ** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are
    03688 ** pointers to C-language functions that implement the SQL function or
    03689 ** aggregate. ^A scalar SQL function requires an implementation of the xFunc
    03690 ** callback only; NULL pointers must be passed as the xStep and xFinal
    03691 ** parameters. ^An aggregate SQL function requires an implementation of xStep
    03692 ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing
    03693 ** SQL function or aggregate, pass NULL pointers for all three function
    03694 ** callbacks.
    03695 **
    03696 ** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL,
    03697 ** then it is destructor for the application data pointer.
    03698 ** The destructor is invoked when the function is deleted, either by being
    03699 ** overloaded or when the database connection closes.)^
    03700 ** ^The destructor is also invoked if the call to
    03701 ** sqlite3_create_function_v2() fails.
    03702 ** ^When the destructor callback of the tenth parameter is invoked, it
    03703 ** is passed a single argument which is a copy of the application data
    03704 ** pointer which was the fifth parameter to sqlite3_create_function_v2().
    03705 **
    03706 ** ^It is permitted to register multiple implementations of the same
    03707 ** functions with the same name but with either differing numbers of
    03708 ** arguments or differing preferred text encodings.  ^SQLite will use
    03709 ** the implementation that most closely matches the way in which the
    03710 ** SQL function is used.  ^A function implementation with a non-negative
    03711 ** nArg parameter is a better match than a function implementation with
    03712 ** a negative nArg.  ^A function where the preferred text encoding
    03713 ** matches the database encoding is a better
    03714 ** match than a function where the encoding is different.
    03715 ** ^A function where the encoding difference is between UTF16le and UTF16be
    03716 ** is a closer match than a function where the encoding difference is
    03717 ** between UTF8 and UTF16.
    03718 **
    03719 ** ^Built-in functions may be overloaded by new application-defined functions.
    03720 **
    03721 ** ^An application-defined function is permitted to call other
    03722 ** SQLite interfaces.  However, such calls must not
    03723 ** close the database connection nor finalize or reset the prepared
    03724 ** statement in which the function is running.
    03725 */
    03726 SQLITE_API int sqlite3_create_function(
    03727   sqlite3 *db,
    03728   const char *zFunctionName,
    03729   int nArg,
    03730   int eTextRep,
    03731   void *pApp,
    03732   void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
    03733   void (*xStep)(sqlite3_context*,int,sqlite3_value**),
    03734   void (*xFinal)(sqlite3_context*)
    03735 );
    03736 SQLITE_API int sqlite3_create_function16(
    03737   sqlite3 *db,
    03738   const void *zFunctionName,
    03739   int nArg,
    03740   int eTextRep,
    03741   void *pApp,
    03742   void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
    03743   void (*xStep)(sqlite3_context*,int,sqlite3_value**),
    03744   void (*xFinal)(sqlite3_context*)
    03745 );
    03746 SQLITE_API int sqlite3_create_function_v2(
    03747   sqlite3 *db,
    03748   const char *zFunctionName,
    03749   int nArg,
    03750   int eTextRep,
    03751   void *pApp,
    03752   void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
    03753   void (*xStep)(sqlite3_context*,int,sqlite3_value**),
    03754   void (*xFinal)(sqlite3_context*),
    03755   void(*xDestroy)(void*)
    03756 );
    03757
    03758 /*
    03759 ** CAPI3REF: Text Encodings
    03760 **
    03761 ** These constant define integer codes that represent the various
    03762 ** text encodings supported by SQLite.
    03763 */
    03764 #define SQLITE_UTF8           1
    03765 #define SQLITE_UTF16LE        2
    03766 #define SQLITE_UTF16BE        3
    03767 #define SQLITE_UTF16          4    /* Use native byte order */
    03768 #define SQLITE_ANY            5    /* sqlite3_create_function only */
    03769 #define SQLITE_UTF16_ALIGNED  8    /* sqlite3_create_collation only */
    03770
    03771 /*
    03772 ** CAPI3REF: Deprecated Functions
    03773 ** DEPRECATED
    03774 **
    03775 ** These functions are [deprecated].  In order to maintain
    03776 ** backwards compatibility with older code, these functions continue
    03777 ** to be supported.  However, new applications should avoid
    03778 ** the use of these functions.  To help encourage people to avoid
    03779 ** using these functions, we are not going to tell you what they do.
    03780 */
    03781 #ifndef SQLITE_OMIT_DEPRECATED
    03782 SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*);
    03783 SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*);
    03784 SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
    03785 SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void);
    03786 SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void);
    03787 SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),void*,sqlite3_int64);
    03788 #endif
    03789
    03790 /*
    03791 ** CAPI3REF: Obtaining SQL Function Parameter Values
    03792 **
    03793 ** The C-language implementation of SQL functions and aggregates uses
    03794 ** this set of interface routines to access the parameter values on
    03795 ** the function or aggregate.
    03796 **
    03797 ** The xFunc (for scalar functions) or xStep (for aggregates) parameters
    03798 ** to [sqlite3_create_function()] and [sqlite3_create_function16()]
    03799 ** define callbacks that implement the SQL functions and aggregates.
    03800 ** The 3rd parameter to these callbacks is an array of pointers to
    03801 ** [protected sqlite3_value] objects.  There is one [sqlite3_value] object for
    03802 ** each parameter to the SQL function.  These routines are used to
    03803 ** extract values from the [sqlite3_value] objects.
    03804 **
    03805 ** These routines work only with [protected sqlite3_value] objects.
    03806 ** Any attempt to use these routines on an [unprotected sqlite3_value]
    03807 ** object results in undefined behavior.
    03808 **
    03809 ** ^These routines work just like the corresponding [column access functions]
    03810 ** except that  these routines take a single [protected sqlite3_value] object
    03811 ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
    03812 **
    03813 ** ^The sqlite3_value_text16() interface extracts a UTF-16 string
    03814 ** in the native byte-order of the host machine.  ^The
    03815 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
    03816 ** extract UTF-16 strings as big-endian and little-endian respectively.
    03817 **
    03818 ** ^(The sqlite3_value_numeric_type() interface attempts to apply
    03819 ** numeric affinity to the value.  This means that an attempt is
    03820 ** made to convert the value to an integer or floating point.  If
    03821 ** such a conversion is possible without loss of information (in other
    03822 ** words, if the value is a string that looks like a number)
    03823 ** then the conversion is performed.  Otherwise no conversion occurs.
    03824 ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
    03825 **
    03826 ** Please pay particular attention to the fact that the pointer returned
    03827 ** from [sqlite3_value_blob()], [sqlite3_value_text()], or
    03828 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to
    03829 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
    03830 ** or [sqlite3_value_text16()].
    03831 **
    03832 ** These routines must be called from the same thread as
    03833 ** the SQL function that supplied the [sqlite3_value*] parameters.
    03834 */
    03835 SQLITE_API const void *sqlite3_value_blob(sqlite3_value*);
    03836 SQLITE_API int sqlite3_value_bytes(sqlite3_value*);
    03837 SQLITE_API int sqlite3_value_bytes16(sqlite3_value*);
    03838 SQLITE_API double sqlite3_value_double(sqlite3_value*);
    03839 SQLITE_API int sqlite3_value_int(sqlite3_value*);
    03840 SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
    03841 SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*);
    03842 SQLITE_API const void *sqlite3_value_text16(sqlite3_value*);
    03843 SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*);
    03844 SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*);
    03845 SQLITE_API int sqlite3_value_type(sqlite3_value*);
    03846 SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*);
    03847
    03848 /*
    03849 ** CAPI3REF: Obtain Aggregate Function Context
    03850 **
    03851 ** Implementations of aggregate SQL functions use this
    03852 ** routine to allocate memory for storing their state.
    03853 **
    03854 ** ^The first time the sqlite3_aggregate_context(C,N) routine is called
    03855 ** for a particular aggregate function, SQLite
    03856 ** allocates N of memory, zeroes out that memory, and returns a pointer
    03857 ** to the new memory. ^On second and subsequent calls to
    03858 ** sqlite3_aggregate_context() for the same aggregate function instance,
    03859 ** the same buffer is returned.  Sqlite3_aggregate_context() is normally
    03860 ** called once for each invocation of the xStep callback and then one
    03861 ** last time when the xFinal callback is invoked.  ^(When no rows match
    03862 ** an aggregate query, the xStep() callback of the aggregate function
    03863 ** implementation is never called and xFinal() is called exactly once.
    03864 ** In those cases, sqlite3_aggregate_context() might be called for the
    03865 ** first time from within xFinal().)^
    03866 **
    03867 ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer if N is
    03868 ** less than or equal to zero or if a memory allocate error occurs.
    03869 **
    03870 ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
    03871 ** determined by the N parameter on first successful call.  Changing the
    03872 ** value of N in subsequent call to sqlite3_aggregate_context() within
    03873 ** the same aggregate function instance will not resize the memory
    03874 ** allocation.)^
    03875 **
    03876 ** ^SQLite automatically frees the memory allocated by
    03877 ** sqlite3_aggregate_context() when the aggregate query concludes.
    03878 **
    03879 ** The first parameter must be a copy of the
    03880 ** [sqlite3_context | SQL function context] that is the first parameter
    03881 ** to the xStep or xFinal callback routine that implements the aggregate
    03882 ** function.
    03883 **
    03884 ** This routine must be called from the same thread in which
    03885 ** the aggregate SQL function is running.
    03886 */
    03887 SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
    03888
    03889 /*
    03890 ** CAPI3REF: User Data For Functions
    03891 **
    03892 ** ^The sqlite3_user_data() interface returns a copy of
    03893 ** the pointer that was the pUserData parameter (the 5th parameter)
    03894 ** of the [sqlite3_create_function()]
    03895 ** and [sqlite3_create_function16()] routines that originally
    03896 ** registered the application defined function.
    03897 **
    03898 ** This routine must be called from the same thread in which
    03899 ** the application-defined function is running.
    03900 */
    03901 SQLITE_API void *sqlite3_user_data(sqlite3_context*);
    03902
    03903 /*
    03904 ** CAPI3REF: Database Connection For Functions
    03905 **
    03906 ** ^The sqlite3_context_db_handle() interface returns a copy of
    03907 ** the pointer to the [database connection] (the 1st parameter)
    03908 ** of the [sqlite3_create_function()]
    03909 ** and [sqlite3_create_function16()] routines that originally
    03910 ** registered the application defined function.
    03911 */
    03912 SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*);
    03913
    03914 /*
    03915 ** CAPI3REF: Function Auxiliary Data
    03916 **
    03917 ** The following two functions may be used by scalar SQL functions to
    03918 ** associate metadata with argument values. If the same value is passed to
    03919 ** multiple invocations of the same SQL function during query execution, under
    03920 ** some circumstances the associated metadata may be preserved. This may
    03921 ** be used, for example, to add a regular-expression matching scalar
    03922 ** function. The compiled version of the regular expression is stored as
    03923 ** metadata associated with the SQL value passed as the regular expression
    03924 ** pattern.  The compiled regular expression can be reused on multiple
    03925 ** invocations of the same function so that the original pattern string
    03926 ** does not need to be recompiled on each invocation.
    03927 **
    03928 ** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata
    03929 ** associated by the sqlite3_set_auxdata() function with the Nth argument
    03930 ** value to the application-defined function. ^If no metadata has been ever
    03931 ** been set for the Nth argument of the function, or if the corresponding
    03932 ** function parameter has changed since the meta-data was set,
    03933 ** then sqlite3_get_auxdata() returns a NULL pointer.
    03934 **
    03935 ** ^The sqlite3_set_auxdata() interface saves the metadata
    03936 ** pointed to by its 3rd parameter as the metadata for the N-th
    03937 ** argument of the application-defined function.  Subsequent
    03938 ** calls to sqlite3_get_auxdata() might return this data, if it has
    03939 ** not been destroyed.
    03940 ** ^If it is not NULL, SQLite will invoke the destructor
    03941 ** function given by the 4th parameter to sqlite3_set_auxdata() on
    03942 ** the metadata when the corresponding function parameter changes
    03943 ** or when the SQL statement completes, whichever comes first.
    03944 **
    03945 ** SQLite is free to call the destructor and drop metadata on any
    03946 ** parameter of any function at any time.  ^The only guarantee is that
    03947 ** the destructor will be called before the metadata is dropped.
    03948 **
    03949 ** ^(In practice, metadata is preserved between function calls for
    03950 ** expressions that are constant at compile time. This includes literal
    03951 ** values and [parameters].)^
    03952 **
    03953 ** These routines must be called from the same thread in which
    03954 ** the SQL function is running.
    03955 */
    03956 SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N);
    03957 SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));
    03958
    03959
    03960 /*
    03961 ** CAPI3REF: Constants Defining Special Destructor Behavior
    03962 **
    03963 ** These are special values for the destructor that is passed in as the
    03964 ** final argument to routines like [sqlite3_result_blob()].  ^If the destructor
    03965 ** argument is SQLITE_STATIC, it means that the content pointer is constant
    03966 ** and will never change.  It does not need to be destroyed.  ^The
    03967 ** SQLITE_TRANSIENT value means that the content will likely change in
    03968 ** the near future and that SQLite should make its own private copy of
    03969 ** the content before returning.
    03970 **
    03971 ** The typedef is necessary to work around problems in certain
    03972 ** C++ compilers.  See ticket #2191.
    03973 */
    03974 typedef void (*sqlite3_destructor_type)(void*);
    03975 #define SQLITE_STATIC      ((sqlite3_destructor_type)0)
    03976 #define SQLITE_TRANSIENT   ((sqlite3_destructor_type)-1)
    03977
    03978 /*
    03979 ** CAPI3REF: Setting The Result Of An SQL Function
    03980 **
    03981 ** These routines are used by the xFunc or xFinal callbacks that
    03982 ** implement SQL functions and aggregates.  See
    03983 ** [sqlite3_create_function()] and [sqlite3_create_function16()]
    03984 ** for additional information.
    03985 **
    03986 ** These functions work very much like the [parameter binding] family of
    03987 ** functions used to bind values to host parameters in prepared statements.
    03988 ** Refer to the [SQL parameter] documentation for additional information.
    03989 **
    03990 ** ^The sqlite3_result_blob() interface sets the result from
    03991 ** an application-defined function to be the BLOB whose content is pointed
    03992 ** to by the second parameter and which is N bytes long where N is the
    03993 ** third parameter.
    03994 **
    03995 ** ^The sqlite3_result_zeroblob() interfaces set the result of
    03996 ** the application-defined function to be a BLOB containing all zero
    03997 ** bytes and N bytes in size, where N is the value of the 2nd parameter.
    03998 **
    03999 ** ^The sqlite3_result_double() interface sets the result from
    04000 ** an application-defined function to be a floating point value specified
    04001 ** by its 2nd argument.
    04002 **
    04003 ** ^The sqlite3_result_error() and sqlite3_result_error16() functions
    04004 ** cause the implemented SQL function to throw an exception.
    04005 ** ^SQLite uses the string pointed to by the
    04006 ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
    04007 ** as the text of an error message.  ^SQLite interprets the error
    04008 ** message string from sqlite3_result_error() as UTF-8. ^SQLite
    04009 ** interprets the string from sqlite3_result_error16() as UTF-16 in native
    04010 ** byte order.  ^If the third parameter to sqlite3_result_error()
    04011 ** or sqlite3_result_error16() is negative then SQLite takes as the error
    04012 ** message all text up through the first zero character.
    04013 ** ^If the third parameter to sqlite3_result_error() or
    04014 ** sqlite3_result_error16() is non-negative then SQLite takes that many
    04015 ** bytes (not characters) from the 2nd parameter as the error message.
    04016 ** ^The sqlite3_result_error() and sqlite3_result_error16()
    04017 ** routines make a private copy of the error message text before
    04018 ** they return.  Hence, the calling function can deallocate or
    04019 ** modify the text after they return without harm.
    04020 ** ^The sqlite3_result_error_code() function changes the error code
    04021 ** returned by SQLite as a result of an error in a function.  ^By default,
    04022 ** the error code is SQLITE_ERROR.  ^A subsequent call to sqlite3_result_error()
    04023 ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
    04024 **
    04025 ** ^The sqlite3_result_toobig() interface causes SQLite to throw an error
    04026 ** indicating that a string or BLOB is too long to represent.
    04027 **
    04028 ** ^The sqlite3_result_nomem() interface causes SQLite to throw an error
    04029 ** indicating that a memory allocation failed.
    04030 **
    04031 ** ^The sqlite3_result_int() interface sets the return value
    04032 ** of the application-defined function to be the 32-bit signed integer
    04033 ** value given in the 2nd argument.
    04034 ** ^The sqlite3_result_int64() interface sets the return value
    04035 ** of the application-defined function to be the 64-bit signed integer
    04036 ** value given in the 2nd argument.
    04037 **
    04038 ** ^The sqlite3_result_null() interface sets the return value
    04039 ** of the application-defined function to be NULL.
    04040 **
    04041 ** ^The sqlite3_result_text(), sqlite3_result_text16(),
    04042 ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
    04043 ** set the return value of the application-defined function to be
    04044 ** a text string which is represented as UTF-8, UTF-16 native byte order,
    04045 ** UTF-16 little endian, or UTF-16 big endian, respectively.
    04046 ** ^SQLite takes the text result from the application from
    04047 ** the 2nd parameter of the sqlite3_result_text* interfaces.
    04048 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces
    04049 ** is negative, then SQLite takes result text from the 2nd parameter
    04050 ** through the first zero character.
    04051 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces
    04052 ** is non-negative, then as many bytes (not characters) of the text
    04053 ** pointed to by the 2nd parameter are taken as the application-defined
    04054 ** function result.  If the 3rd parameter is non-negative, then it
    04055 ** must be the byte offset into the string where the NUL terminator would
    04056 ** appear if the string where NUL terminated.  If any NUL characters occur
    04057 ** in the string at a byte offset that is less than the value of the 3rd
    04058 ** parameter, then the resulting string will contain embedded NULs and the
    04059 ** result of expressions operating on strings with embedded NULs is undefined.
    04060 ** ^If the 4th parameter to the sqlite3_result_text* interfaces
    04061 ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
    04062 ** function as the destructor on the text or BLOB result when it has
    04063 ** finished using that result.
    04064 ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to
    04065 ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
    04066 ** assumes that the text or BLOB result is in constant space and does not
    04067 ** copy the content of the parameter nor call a destructor on the content
    04068 ** when it has finished using that result.
    04069 ** ^If the 4th parameter to the sqlite3_result_text* interfaces
    04070 ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
    04071 ** then SQLite makes a copy of the result into space obtained from
    04072 ** from [sqlite3_malloc()] before it returns.
    04073 **
    04074 ** ^The sqlite3_result_value() interface sets the result of
    04075 ** the application-defined function to be a copy the
    04076 ** [unprotected sqlite3_value] object specified by the 2nd parameter.  ^The
    04077 ** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
    04078 ** so that the [sqlite3_value] specified in the parameter may change or
    04079 ** be deallocated after sqlite3_result_value() returns without harm.
    04080 ** ^A [protected sqlite3_value] object may always be used where an
    04081 ** [unprotected sqlite3_value] object is required, so either
    04082 ** kind of [sqlite3_value] object can be used with this interface.
    04083 **
    04084 ** If these routines are called from within the different thread
    04085 ** than the one containing the application-defined function that received
    04086 ** the [sqlite3_context] pointer, the results are undefined.
    04087 */
    04088 SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
    04089 SQLITE_API void sqlite3_result_double(sqlite3_context*, double);
    04090 SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int);
    04091 SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int);
    04092 SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*);
    04093 SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*);
    04094 SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int);
    04095 SQLITE_API void sqlite3_result_int(sqlite3_context*, int);
    04096 SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
    04097 SQLITE_API void sqlite3_result_null(sqlite3_context*);
    04098 SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
    04099 SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
    04100 SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
    04101 SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
    04102 SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
    04103 SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n);
    04104
    04105 /*
    04106 ** CAPI3REF: Define New Collating Sequences
    04107 **
    04108 ** ^These functions add, remove, or modify a [collation] associated
    04109 ** with the [database connection] specified as the first argument.
    04110 **
    04111 ** ^The name of the collation is a UTF-8 string
    04112 ** for sqlite3_create_collation() and sqlite3_create_collation_v2()
    04113 ** and a UTF-16 string in native byte order for sqlite3_create_collation16().
    04114 ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are
    04115 ** considered to be the same name.
    04116 **
    04117 ** ^(The third argument (eTextRep) must be one of the constants:
    04118 ** <ul>
    04119 ** <li> [SQLITE_UTF8],
    04120 ** <li> [SQLITE_UTF16LE],
    04121 ** <li> [SQLITE_UTF16BE],
    04122 ** <li> [SQLITE_UTF16], or
    04123 ** <li> [SQLITE_UTF16_ALIGNED].
    04124 ** </ul>)^
    04125 ** ^The eTextRep argument determines the encoding of strings passed
    04126 ** to the collating function callback, xCallback.
    04127 ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep
    04128 ** force strings to be UTF16 with native byte order.
    04129 ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin
    04130 ** on an even byte address.
    04131 **
    04132 ** ^The fourth argument, pArg, is an application data pointer that is passed
    04133 ** through as the first argument to the collating function callback.
    04134 **
    04135 ** ^The fifth argument, xCallback, is a pointer to the collating function.
    04136 ** ^Multiple collating functions can be registered using the same name but
    04137 ** with different eTextRep parameters and SQLite will use whichever
    04138 ** function requires the least amount of data transformation.
    04139 ** ^If the xCallback argument is NULL then the collating function is
    04140 ** deleted.  ^When all collating functions having the same name are deleted,
    04141 ** that collation is no longer usable.
    04142 **
    04143 ** ^The collating function callback is invoked with a copy of the pArg
    04144 ** application data pointer and with two strings in the encoding specified
    04145 ** by the eTextRep argument.  The collating function must return an
    04146 ** integer that is negative, zero, or positive
    04147 ** if the first string is less than, equal to, or greater than the second,
    04148 ** respectively.  A collating function must always return the same answer
    04149 ** given the same inputs.  If two or more collating functions are registered
    04150 ** to the same collation name (using different eTextRep values) then all
    04151 ** must give an equivalent answer when invoked with equivalent strings.
    04152 ** The collating function must obey the following properties for all
    04153 ** strings A, B, and C:
    04154 **
    04155 ** <ol>
    04156 ** <li> If A==B then B==A.
    04157 ** <li> If A==B and B==C then A==C.
    04158 ** <li> If A&lt;B THEN B&gt;A.
    04159 ** <li> If A&lt;B and B&lt;C then A&lt;C.
    04160 ** </ol>
    04161 **
    04162 ** If a collating function fails any of the above constraints and that
    04163 ** collating function is  registered and used, then the behavior of SQLite
    04164 ** is undefined.
    04165 **
    04166 ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()
    04167 ** with the addition that the xDestroy callback is invoked on pArg when
    04168 ** the collating function is deleted.
    04169 ** ^Collating functions are deleted when they are overridden by later
    04170 ** calls to the collation creation functions or when the
    04171 ** [database connection] is closed using [sqlite3_close()].
    04172 **
    04173 ** ^The xDestroy callback is <u>not</u> called if the
    04174 ** sqlite3_create_collation_v2() function fails.  Applications that invoke
    04175 ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should
    04176 ** check the return code and dispose of the application data pointer
    04177 ** themselves rather than expecting SQLite to deal with it for them.
    04178 ** This is different from every other SQLite interface.  The inconsistency
    04179 ** is unfortunate but cannot be changed without breaking backwards
    04180 ** compatibility.
    04181 **
    04182 ** See also:  [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
    04183 */
    04184 SQLITE_API int sqlite3_create_collation(
    04185   sqlite3*,
    04186   const char *zName,
    04187   int eTextRep,
    04188   void *pArg,
    04189   int(*xCompare)(void*,int,const void*,int,const void*)
    04190 );
    04191 SQLITE_API int sqlite3_create_collation_v2(
    04192   sqlite3*,
    04193   const char *zName,
    04194   int eTextRep,
    04195   void *pArg,
    04196   int(*xCompare)(void*,int,const void*,int,const void*),
    04197   void(*xDestroy)(void*)
    04198 );
    04199 SQLITE_API int sqlite3_create_collation16(
    04200   sqlite3*,
    04201   const void *zName,
    04202   int eTextRep,
    04203   void *pArg,
    04204   int(*xCompare)(void*,int,const void*,int,const void*)
    04205 );
    04206
    04207 /*
    04208 ** CAPI3REF: Collation Needed Callbacks
    04209 **
    04210 ** ^To avoid having to register all collation sequences before a database
    04211 ** can be used, a single callback function may be registered with the
    04212 ** [database connection] to be invoked whenever an undefined collation
    04213 ** sequence is required.
    04214 **
    04215 ** ^If the function is registered using the sqlite3_collation_needed() API,
    04216 ** then it is passed the names of undefined collation sequences as strings
    04217 ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,
    04218 ** the names are passed as UTF-16 in machine native byte order.
    04219 ** ^A call to either function replaces the existing collation-needed callback.
    04220 **
    04221 ** ^(When the callback is invoked, the first argument passed is a copy
    04222 ** of the second argument to sqlite3_collation_needed() or
    04223 ** sqlite3_collation_needed16().  The second argument is the database
    04224 ** connection.  The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
    04225 ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
    04226 ** sequence function required.  The fourth parameter is the name of the
    04227 ** required collation sequence.)^
    04228 **
    04229 ** The callback function should register the desired collation using
    04230 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
    04231 ** [sqlite3_create_collation_v2()].
    04232 */
    04233 SQLITE_API int sqlite3_collation_needed(
    04234   sqlite3*,
    04235   void*,
    04236   void(*)(void*,sqlite3*,int eTextRep,const char*)
    04237 );
    04238 SQLITE_API int sqlite3_collation_needed16(
    04239   sqlite3*,
    04240   void*,
    04241   void(*)(void*,sqlite3*,int eTextRep,const void*)
    04242 );
    04243
    04244 #ifdef SQLITE_HAS_CODEC
    04245 /*
    04246 ** Specify the key for an encrypted database.  This routine should be
    04247 ** called right after sqlite3_open().
    04248 **
    04249 ** The code to implement this API is not available in the public release
    04250 ** of SQLite.
    04251 */
    04252 SQLITE_API int sqlite3_key(
    04253   sqlite3 *db,                   /* Database to be rekeyed */
    04254   const void *pKey, int nKey     /* The key */
    04255 );
    04256
    04257 /*
    04258 ** Change the key on an open database.  If the current database is not
    04259 ** encrypted, this routine will encrypt it.  If pNew==0 or nNew==0, the
    04260 ** database is decrypted.
    04261 **
    04262 ** The code to implement this API is not available in the public release
    04263 ** of SQLite.
    04264 */
    04265 SQLITE_API int sqlite3_rekey(
    04266   sqlite3 *db,                   /* Database to be rekeyed */
    04267   const void *pKey, int nKey     /* The new key */
    04268 );
    04269
    04270 /*
    04271 ** Specify the activation key for a SEE database.  Unless
    04272 ** activated, none of the SEE routines will work.
    04273 */
    04274 SQLITE_API void sqlite3_activate_see(
    04275   const char *zPassPhrase        /* Activation phrase */
    04276 );
    04277 #endif
    04278
    04279 #ifdef SQLITE_ENABLE_CEROD
    04280 /*
    04281 ** Specify the activation key for a CEROD database.  Unless
    04282 ** activated, none of the CEROD routines will work.
    04283 */
    04284 SQLITE_API void sqlite3_activate_cerod(
    04285   const char *zPassPhrase        /* Activation phrase */
    04286 );
    04287 #endif
    04288
    04289 /*
    04290 ** CAPI3REF: Suspend Execution For A Short Time
    04291 **
    04292 ** The sqlite3_sleep() function causes the current thread to suspend execution
    04293 ** for at least a number of milliseconds specified in its parameter.
    04294 **
    04295 ** If the operating system does not support sleep requests with
    04296 ** millisecond time resolution, then the time will be rounded up to
    04297 ** the nearest second. The number of milliseconds of sleep actually
    04298 ** requested from the operating system is returned.
    04299 **
    04300 ** ^SQLite implements this interface by calling the xSleep()
    04301 ** method of the default [sqlite3_vfs] object.  If the xSleep() method
    04302 ** of the default VFS is not implemented correctly, or not implemented at
    04303 ** all, then the behavior of sqlite3_sleep() may deviate from the description
    04304 ** in the previous paragraphs.
    04305 */
    04306 SQLITE_API int sqlite3_sleep(int);
    04307
    04308 /*
    04309 ** CAPI3REF: Name Of The Folder Holding Temporary Files
    04310 **
    04311 ** ^(If this global variable is made to point to a string which is
    04312 ** the name of a folder (a.k.a. directory), then all temporary files
    04313 ** created by SQLite when using a built-in [sqlite3_vfs | VFS]
    04314 ** will be placed in that directory.)^  ^If this variable
    04315 ** is a NULL pointer, then SQLite performs a search for an appropriate
    04316 ** temporary file directory.
    04317 **
    04318 ** It is not safe to read or modify this variable in more than one
    04319 ** thread at a time.  It is not safe to read or modify this variable
    04320 ** if a [database connection] is being used at the same time in a separate
    04321 ** thread.
    04322 ** It is intended that this variable be set once
    04323 ** as part of process initialization and before any SQLite interface
    04324 ** routines have been called and that this variable remain unchanged
    04325 ** thereafter.
    04326 **
    04327 ** ^The [temp_store_directory pragma] may modify this variable and cause
    04328 ** it to point to memory obtained from [sqlite3_malloc].  ^Furthermore,
    04329 ** the [temp_store_directory pragma] always assumes that any string
    04330 ** that this variable points to is held in memory obtained from
    04331 ** [sqlite3_malloc] and the pragma may attempt to free that memory
    04332 ** using [sqlite3_free].
    04333 ** Hence, if this variable is modified directly, either it should be
    04334 ** made NULL or made to point to memory obtained from [sqlite3_malloc]
    04335 ** or else the use of the [temp_store_directory pragma] should be avoided.
    04336 */
    04337 SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory;
    04338
    04339 /*
    04340 ** CAPI3REF: Test For Auto-Commit Mode
    04341 ** KEYWORDS: {autocommit mode}
    04342 **
    04343 ** ^The sqlite3_get_autocommit() interface returns non-zero or
    04344 ** zero if the given database connection is or is not in autocommit mode,
    04345 ** respectively.  ^Autocommit mode is on by default.
    04346 ** ^Autocommit mode is disabled by a [BEGIN] statement.
    04347 ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
    04348 **
    04349 ** If certain kinds of errors occur on a statement within a multi-statement
    04350 ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
    04351 ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
    04352 ** transaction might be rolled back automatically.  The only way to
    04353 ** find out whether SQLite automatically rolled back the transaction after
    04354 ** an error is to use this function.
    04355 **
    04356 ** If another thread changes the autocommit status of the database
    04357 ** connection while this routine is running, then the return value
    04358 ** is undefined.
    04359 */
    04360 SQLITE_API int sqlite3_get_autocommit(sqlite3*);
    04361
    04362 /*
    04363 ** CAPI3REF: Find The Database Handle Of A Prepared Statement
    04364 **
    04365 ** ^The sqlite3_db_handle interface returns the [database connection] handle
    04366 ** to which a [prepared statement] belongs.  ^The [database connection]
    04367 ** returned by sqlite3_db_handle is the same [database connection]
    04368 ** that was the first argument
    04369 ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
    04370 ** create the statement in the first place.
    04371 */
    04372 SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
    04373
    04374 /*
    04375 ** CAPI3REF: Find the next prepared statement
    04376 **
    04377 ** ^This interface returns a pointer to the next [prepared statement] after
    04378 ** pStmt associated with the [database connection] pDb.  ^If pStmt is NULL
    04379 ** then this interface returns a pointer to the first prepared statement
    04380 ** associated with the database connection pDb.  ^If no prepared statement
    04381 ** satisfies the conditions of this routine, it returns NULL.
    04382 **
    04383 ** The [database connection] pointer D in a call to
    04384 ** [sqlite3_next_stmt(D,S)] must refer to an open database
    04385 ** connection and in particular must not be a NULL pointer.
    04386 */
    04387 SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);
    04388
    04389 /*
    04390 ** CAPI3REF: Commit And Rollback Notification Callbacks
    04391 **
    04392 ** ^The sqlite3_commit_hook() interface registers a callback
    04393 ** function to be invoked whenever a transaction is [COMMIT | committed].
    04394 ** ^Any callback set by a previous call to sqlite3_commit_hook()
    04395 ** for the same database connection is overridden.
    04396 ** ^The sqlite3_rollback_hook() interface registers a callback
    04397 ** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
    04398 ** ^Any callback set by a previous call to sqlite3_rollback_hook()
    04399 ** for the same database connection is overridden.
    04400 ** ^The pArg argument is passed through to the callback.
    04401 ** ^If the callback on a commit hook function returns non-zero,
    04402 ** then the commit is converted into a rollback.
    04403 **
    04404 ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
    04405 ** return the P argument from the previous call of the same function
    04406 ** on the same [database connection] D, or NULL for
    04407 ** the first call for each function on D.
    04408 **
    04409 ** The callback implementation must not do anything that will modify
    04410 ** the database connection that invoked the callback.  Any actions
    04411 ** to modify the database connection must be deferred until after the
    04412 ** completion of the [sqlite3_step()] call that triggered the commit
    04413 ** or rollback hook in the first place.
    04414 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
    04415 ** database connections for the meaning of "modify" in this paragraph.
    04416 **
    04417 ** ^Registering a NULL function disables the callback.
    04418 **
    04419 ** ^When the commit hook callback routine returns zero, the [COMMIT]
    04420 ** operation is allowed to continue normally.  ^If the commit hook
    04421 ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
    04422 ** ^The rollback hook is invoked on a rollback that results from a commit
    04423 ** hook returning non-zero, just as it would be with any other rollback.
    04424 **
    04425 ** ^For the purposes of this API, a transaction is said to have been
    04426 ** rolled back if an explicit "ROLLBACK" statement is executed, or
    04427 ** an error or constraint causes an implicit rollback to occur.
    04428 ** ^The rollback callback is not invoked if a transaction is
    04429 ** automatically rolled back because the database connection is closed.
    04430 **
    04431 ** See also the [sqlite3_update_hook()] interface.
    04432 */
    04433 SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
    04434 SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
    04435
    04436 /*
    04437 ** CAPI3REF: Data Change Notification Callbacks
    04438 **
    04439 ** ^The sqlite3_update_hook() interface registers a callback function
    04440 ** with the [database connection] identified by the first argument
    04441 ** to be invoked whenever a row is updated, inserted or deleted.
    04442 ** ^Any callback set by a previous call to this function
    04443 ** for the same database connection is overridden.
    04444 **
    04445 ** ^The second argument is a pointer to the function to invoke when a
    04446 ** row is updated, inserted or deleted.
    04447 ** ^The first argument to the callback is a copy of the third argument
    04448 ** to sqlite3_update_hook().
    04449 ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
    04450 ** or [SQLITE_UPDATE], depending on the operation that caused the callback
    04451 ** to be invoked.
    04452 ** ^The third and fourth arguments to the callback contain pointers to the
    04453 ** database and table name containing the affected row.
    04454 ** ^The final callback parameter is the [rowid] of the row.
    04455 ** ^In the case of an update, this is the [rowid] after the update takes place.
    04456 **
    04457 ** ^(The update hook is not invoked when internal system tables are
    04458 ** modified (i.e. sqlite_master and sqlite_sequence).)^
    04459 **
    04460 ** ^In the current implementation, the update hook
    04461 ** is not invoked when duplication rows are deleted because of an
    04462 ** [ON CONFLICT | ON CONFLICT REPLACE] clause.  ^Nor is the update hook
    04463 ** invoked when rows are deleted using the [truncate optimization].
    04464 ** The exceptions defined in this paragraph might change in a future
    04465 ** release of SQLite.
    04466 **
    04467 ** The update hook implementation must not do anything that will modify
    04468 ** the database connection that invoked the update hook.  Any actions
    04469 ** to modify the database connection must be deferred until after the
    04470 ** completion of the [sqlite3_step()] call that triggered the update hook.
    04471 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
    04472 ** database connections for the meaning of "modify" in this paragraph.
    04473 **
    04474 ** ^The sqlite3_update_hook(D,C,P) function
    04475 ** returns the P argument from the previous call
    04476 ** on the same [database connection] D, or NULL for
    04477 ** the first call on D.
    04478 **
    04479 ** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()]
    04480 ** interfaces.
    04481 */
    04482 SQLITE_API void *sqlite3_update_hook(
    04483   sqlite3*,
    04484   void(*)(void *,int ,char const *,char const *,sqlite3_int64),
    04485   void*
    04486 );
    04487
    04488 /*
    04489 ** CAPI3REF: Enable Or Disable Shared Pager Cache
    04490 ** KEYWORDS: {shared cache}
    04491 **
    04492 ** ^(This routine enables or disables the sharing of the database cache
    04493 ** and schema data structures between [database connection | connections]
    04494 ** to the same database. Sharing is enabled if the argument is true
    04495 ** and disabled if the argument is false.)^
    04496 **
    04497 ** ^Cache sharing is enabled and disabled for an entire process.
    04498 ** This is a change as of SQLite version 3.5.0. In prior versions of SQLite,
    04499 ** sharing was enabled or disabled for each thread separately.
    04500 **
    04501 ** ^(The cache sharing mode set by this interface effects all subsequent
    04502 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
    04503 ** Existing database connections continue use the sharing mode
    04504 ** that was in effect at the time they were opened.)^
    04505 **
    04506 ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
    04507 ** successfully.  An [error code] is returned otherwise.)^
    04508 **
    04509 ** ^Shared cache is disabled by default. But this might change in
    04510 ** future releases of SQLite.  Applications that care about shared
    04511 ** cache setting should set it explicitly.
    04512 **
    04513 ** See Also:  [SQLite Shared-Cache Mode]
    04514 */
    04515 SQLITE_API int sqlite3_enable_shared_cache(int);
    04516
    04517 /*
    04518 ** CAPI3REF: Attempt To Free Heap Memory
    04519 **
    04520 ** ^The sqlite3_release_memory() interface attempts to free N bytes
    04521 ** of heap memory by deallocating non-essential memory allocations
    04522 ** held by the database library.   Memory used to cache database
    04523 ** pages to improve performance is an example of non-essential memory.
    04524 ** ^sqlite3_release_memory() returns the number of bytes actually freed,
    04525 ** which might be more or less than the amount requested.
    04526 ** ^The sqlite3_release_memory() routine is a no-op returning zero
    04527 ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT].
    04528 */
    04529 SQLITE_API int sqlite3_release_memory(int);
    04530
    04531 /*
    04532 ** CAPI3REF: Impose A Limit On Heap Size
    04533 **
    04534 ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the
    04535 ** soft limit on the amount of heap memory that may be allocated by SQLite.
    04536 ** ^SQLite strives to keep heap memory utilization below the soft heap
    04537 ** limit by reducing the number of pages held in the page cache
    04538 ** as heap memory usages approaches the limit.
    04539 ** ^The soft heap limit is "soft" because even though SQLite strives to stay
    04540 ** below the limit, it will exceed the limit rather than generate
    04541 ** an [SQLITE_NOMEM] error.  In other words, the soft heap limit
    04542 ** is advisory only.
    04543 **
    04544 ** ^The return value from sqlite3_soft_heap_limit64() is the size of
    04545 ** the soft heap limit prior to the call.  ^If the argument N is negative
    04546 ** then no change is made to the soft heap limit.  Hence, the current
    04547 ** size of the soft heap limit can be determined by invoking
    04548 ** sqlite3_soft_heap_limit64() with a negative argument.
    04549 **
    04550 ** ^If the argument N is zero then the soft heap limit is disabled.
    04551 **
    04552 ** ^(The soft heap limit is not enforced in the current implementation
    04553 ** if one or more of following conditions are true:
    04554 **
    04555 ** <ul>
    04556 ** <li> The soft heap limit is set to zero.
    04557 ** <li> Memory accounting is disabled using a combination of the
    04558 **      [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and
    04559 **      the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.
    04560 ** <li> An alternative page cache implementation is specified using
    04561 **      [sqlite3_config]([SQLITE_CONFIG_PCACHE],...).
    04562 ** <li> The page cache allocates from its own memory pool supplied
    04563 **      by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than
    04564 **      from the heap.
    04565 ** </ul>)^
    04566 **
    04567 ** Beginning with SQLite version 3.7.3, the soft heap limit is enforced
    04568 ** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT]
    04569 ** compile-time option is invoked.  With [SQLITE_ENABLE_MEMORY_MANAGEMENT],
    04570 ** the soft heap limit is enforced on every memory allocation.  Without
    04571 ** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced
    04572 ** when memory is allocated by the page cache.  Testing suggests that because
    04573 ** the page cache is the predominate memory user in SQLite, most
    04574 ** applications will achieve adequate soft heap limit enforcement without
    04575 ** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT].
    04576 **
    04577 ** The circumstances under which SQLite will enforce the soft heap limit may
    04578 ** changes in future releases of SQLite.
    04579 */
    04580 SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N);
    04581
    04582 /*
    04583 ** CAPI3REF: Deprecated Soft Heap Limit Interface
    04584 ** DEPRECATED
    04585 **
    04586 ** This is a deprecated version of the [sqlite3_soft_heap_limit64()]
    04587 ** interface.  This routine is provided for historical compatibility
    04588 ** only.  All new applications should use the
    04589 ** [sqlite3_soft_heap_limit64()] interface rather than this one.
    04590 */
    04591 SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N);
    04592
    04593
    04594 /*
    04595 ** CAPI3REF: Extract Metadata About A Column Of A Table
    04596 **
    04597 ** ^This routine returns metadata about a specific column of a specific
    04598 ** database table accessible using the [database connection] handle
    04599 ** passed as the first function argument.
    04600 **
    04601 ** ^The column is identified by the second, third and fourth parameters to
    04602 ** this function. ^The second parameter is either the name of the database
    04603 ** (i.e. "main", "temp", or an attached database) containing the specified
    04604 ** table or NULL. ^If it is NULL, then all attached databases are searched
    04605 ** for the table using the same algorithm used by the database engine to
    04606 ** resolve unqualified table references.
    04607 **
    04608 ** ^The third and fourth parameters to this function are the table and column
    04609 ** name of the desired column, respectively. Neither of these parameters
    04610 ** may be NULL.
    04611 **
    04612 ** ^Metadata is returned by writing to the memory locations passed as the 5th
    04613 ** and subsequent parameters to this function. ^Any of these arguments may be
    04614 ** NULL, in which case the corresponding element of metadata is omitted.
    04615 **
    04616 ** ^(<blockquote>
    04617 ** <table border="1">
    04618 ** <tr><th> Parameter <th> Output<br>Type <th>  Description
    04619 **
    04620 ** <tr><td> 5th <td> const char* <td> Data type
    04621 ** <tr><td> 6th <td> const char* <td> Name of default collation sequence
    04622 ** <tr><td> 7th <td> int         <td> True if column has a NOT NULL constraint
    04623 ** <tr><td> 8th <td> int         <td> True if column is part of the PRIMARY KEY
    04624 ** <tr><td> 9th <td> int         <td> True if column is [AUTOINCREMENT]
    04625 ** </table>
    04626 ** </blockquote>)^
    04627 **
    04628 ** ^The memory pointed to by the character pointers returned for the
    04629 ** declaration type and collation sequence is valid only until the next
    04630 ** call to any SQLite API function.
    04631 **
    04632 ** ^If the specified table is actually a view, an [error code] is returned.
    04633 **
    04634 ** ^If the specified column is "rowid", "oid" or "_rowid_" and an
    04635 ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
    04636 ** parameters are set for the explicitly declared column. ^(If there is no
    04637 ** explicitly declared [INTEGER PRIMARY KEY] column, then the output
    04638 ** parameters are set as follows:
    04639 **
    04640 ** <pre>
    04641 **     data type: "INTEGER"
    04642 **     collation sequence: "BINARY"
    04643 **     not null: 0
    04644 **     primary key: 1
    04645 **     auto increment: 0
    04646 ** </pre>)^
    04647 **
    04648 ** ^(This function may load one or more schemas from database files. If an
    04649 ** error occurs during this process, or if the requested table or column
    04650 ** cannot be found, an [error code] is returned and an error message left
    04651 ** in the [database connection] (to be retrieved using sqlite3_errmsg()).)^
    04652 **
    04653 ** ^This API is only available if the library was compiled with the
    04654 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined.
    04655 */
    04656 SQLITE_API int sqlite3_table_column_metadata(
    04657   sqlite3 *db,                /* Connection handle */
    04658   const char *zDbName,        /* Database name or NULL */
    04659   const char *zTableName,     /* Table name */
    04660   const char *zColumnName,    /* Column name */
    04661   char const **pzDataType,    /* OUTPUT: Declared data type */
    04662   char const **pzCollSeq,     /* OUTPUT: Collation sequence name */
    04663   int *pNotNull,              /* OUTPUT: True if NOT NULL constraint exists */
    04664   int *pPrimaryKey,           /* OUTPUT: True if column part of PK */
    04665   int *pAutoinc               /* OUTPUT: True if column is auto-increment */
    04666 );
    04667
    04668 /*
    04669 ** CAPI3REF: Load An Extension
    04670 **
    04671 ** ^This interface loads an SQLite extension library from the named file.
    04672 **
    04673 ** ^The sqlite3_load_extension() interface attempts to load an
    04674 ** SQLite extension library contained in the file zFile.
    04675 **
    04676 ** ^The entry point is zProc.
    04677 ** ^zProc may be 0, in which case the name of the entry point
    04678 ** defaults to "sqlite3_extension_init".
    04679 ** ^The sqlite3_load_extension() interface returns
    04680 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
    04681 ** ^If an error occurs and pzErrMsg is not 0, then the
    04682 ** [sqlite3_load_extension()] interface shall attempt to
    04683 ** fill *pzErrMsg with error message text stored in memory
    04684 ** obtained from [sqlite3_malloc()]. The calling function
    04685 ** should free this memory by calling [sqlite3_free()].
    04686 **
    04687 ** ^Extension loading must be enabled using
    04688 ** [sqlite3_enable_load_extension()] prior to calling this API,
    04689 ** otherwise an error will be returned.
    04690 **
    04691 ** See also the [load_extension() SQL function].
    04692 */
    04693 SQLITE_API int sqlite3_load_extension(
    04694   sqlite3 *db,          /* Load the extension into this database connection */
    04695   const char *zFile,    /* Name of the shared library containing extension */
    04696   const char *zProc,    /* Entry point.  Derived from zFile if 0 */
    04697   char **pzErrMsg       /* Put error message here if not 0 */
    04698 );
    04699
    04700 /*
    04701 ** CAPI3REF: Enable Or Disable Extension Loading
    04702 **
    04703 ** ^So as not to open security holes in older applications that are
    04704 ** unprepared to deal with extension loading, and as a means of disabling
    04705 ** extension loading while evaluating user-entered SQL, the following API
    04706 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
    04707 **
    04708 ** ^Extension loading is off by default. See ticket #1863.
    04709 ** ^Call the sqlite3_enable_load_extension() routine with onoff==1
    04710 ** to turn extension loading on and call it with onoff==0 to turn
    04711 ** it back off again.
    04712 */
    04713 SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
    04714
    04715 /*
    04716 ** CAPI3REF: Automatically Load Statically Linked Extensions
    04717 **
    04718 ** ^This interface causes the xEntryPoint() function to be invoked for
    04719 ** each new [database connection] that is created.  The idea here is that
    04720 ** xEntryPoint() is the entry point for a statically linked SQLite extension
    04721 ** that is to be automatically loaded into all new database connections.
    04722 **
    04723 ** ^(Even though the function prototype shows that xEntryPoint() takes
    04724 ** no arguments and returns void, SQLite invokes xEntryPoint() with three
    04725 ** arguments and expects and integer result as if the signature of the
    04726 ** entry point where as follows:
    04727 **
    04728 ** <blockquote><pre>
    04729 ** &nbsp;  int xEntryPoint(
    04730 ** &nbsp;    sqlite3 *db,
    04731 ** &nbsp;    const char **pzErrMsg,
    04732 ** &nbsp;    const struct sqlite3_api_routines *pThunk
    04733 ** &nbsp;  );
    04734 ** </pre></blockquote>)^
    04735 **
    04736 ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg
    04737 ** point to an appropriate error message (obtained from [sqlite3_mprintf()])
    04738 ** and return an appropriate [error code].  ^SQLite ensures that *pzErrMsg
    04739 ** is NULL before calling the xEntryPoint().  ^SQLite will invoke
    04740 ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns.  ^If any
    04741 ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()],
    04742 ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail.
    04743 **
    04744 ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already
    04745 ** on the list of automatic extensions is a harmless no-op. ^No entry point
    04746 ** will be called more than once for each database connection that is opened.
    04747 **
    04748 ** See also: [sqlite3_reset_auto_extension()].
    04749 */
    04750 SQLITE_API int sqlite3_auto_extension(void (*xEntryPoint)(void));
    04751
    04752 /*
    04753 ** CAPI3REF: Reset Automatic Extension Loading
    04754 **
    04755 ** ^This interface disables all automatic extensions previously
    04756 ** registered using [sqlite3_auto_extension()].
    04757 */
    04758 SQLITE_API void sqlite3_reset_auto_extension(void);
    04759
    04760 /*
    04761 ** The interface to the virtual-table mechanism is currently considered
    04762 ** to be experimental.  The interface might change in incompatible ways.
    04763 ** If this is a problem for you, do not use the interface at this time.
    04764 **
    04765 ** When the virtual-table mechanism stabilizes, we will declare the
    04766 ** interface fixed, support it indefinitely, and remove this comment.
    04767 */
    04768
    04769 /*
    04770 ** Structures used by the virtual table interface
    04771 */
    04772 typedef struct sqlite3_vtab sqlite3_vtab;
    04773 typedef struct sqlite3_index_info sqlite3_index_info;
    04774 typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
    04775 typedef struct sqlite3_module sqlite3_module;
    04776
    04777 /*
    04778 ** CAPI3REF: Virtual Table Object
    04779 ** KEYWORDS: sqlite3_module {virtual table module}
    04780 **
    04781 ** This structure, sometimes called a "virtual table module",
    04782 ** defines the implementation of a [virtual tables].
    04783 ** This structure consists mostly of methods for the module.
    04784 **
    04785 ** ^A virtual table module is created by filling in a persistent
    04786 ** instance of this structure and passing a pointer to that instance
    04787 ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
    04788 ** ^The registration remains valid until it is replaced by a different
    04789 ** module or until the [database connection] closes.  The content
    04790 ** of this structure must not change while it is registered with
    04791 ** any database connection.
    04792 */
    04793 struct sqlite3_module {
    04794   int iVersion;
    04795   int (*xCreate)(sqlite3*, void *pAux,
    04796                int argc, const char *const*argv,
    04797                sqlite3_vtab **ppVTab, char**);
    04798   int (*xConnect)(sqlite3*, void *pAux,
    04799                int argc, const char *const*argv,
    04800                sqlite3_vtab **ppVTab, char**);
    04801   int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
    04802   int (*xDisconnect)(sqlite3_vtab *pVTab);
    04803   int (*xDestroy)(sqlite3_vtab *pVTab);
    04804   int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
    04805   int (*xClose)(sqlite3_vtab_cursor*);
    04806   int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
    04807                 int argc, sqlite3_value **argv);
    04808   int (*xNext)(sqlite3_vtab_cursor*);
    04809   int (*xEof)(sqlite3_vtab_cursor*);
    04810   int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
    04811   int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
    04812   int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
    04813   int (*xBegin)(sqlite3_vtab *pVTab);
    04814   int (*xSync)(sqlite3_vtab *pVTab);
    04815   int (*xCommit)(sqlite3_vtab *pVTab);
    04816   int (*xRollback)(sqlite3_vtab *pVTab);
    04817   int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
    04818                        void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
    04819                        void **ppArg);
    04820   int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
    04821   /* The methods above are in version 1 of the sqlite_module object. Those
    04822   ** below are for version 2 and greater. */
    04823   int (*xSavepoint)(sqlite3_vtab *pVTab, int);
    04824   int (*xRelease)(sqlite3_vtab *pVTab, int);
    04825   int (*xRollbackTo)(sqlite3_vtab *pVTab, int);
    04826 };
    04827
    04828 /*
    04829 ** CAPI3REF: Virtual Table Indexing Information
    04830 ** KEYWORDS: sqlite3_index_info
    04831 **
    04832 ** The sqlite3_index_info structure and its substructures is used as part
    04833 ** of the [virtual table] interface to
    04834 ** pass information into and receive the reply from the [xBestIndex]
    04835 ** method of a [virtual table module].  The fields under **Inputs** are the
    04836 ** inputs to xBestIndex and are read-only.  xBestIndex inserts its
    04837 ** results into the **Outputs** fields.
    04838 **
    04839 ** ^(The aConstraint[] array records WHERE clause constraints of the form:
    04840 **
    04841 ** <blockquote>column OP expr</blockquote>
    04842 **
    04843 ** where OP is =, &lt;, &lt;=, &gt;, or &gt;=.)^  ^(The particular operator is
    04844 ** stored in aConstraint[].op using one of the
    04845 ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^
    04846 ** ^(The index of the column is stored in
    04847 ** aConstraint[].iColumn.)^  ^(aConstraint[].usable is TRUE if the
    04848 ** expr on the right-hand side can be evaluated (and thus the constraint
    04849 ** is usable) and false if it cannot.)^
    04850 **
    04851 ** ^The optimizer automatically inverts terms of the form "expr OP column"
    04852 ** and makes other simplifications to the WHERE clause in an attempt to
    04853 ** get as many WHERE clause terms into the form shown above as possible.
    04854 ** ^The aConstraint[] array only reports WHERE clause terms that are
    04855 ** relevant to the particular virtual table being queried.
    04856 **
    04857 ** ^Information about the ORDER BY clause is stored in aOrderBy[].
    04858 ** ^Each term of aOrderBy records a column of the ORDER BY clause.
    04859 **
    04860 ** The [xBestIndex] method must fill aConstraintUsage[] with information
    04861 ** about what parameters to pass to xFilter.  ^If argvIndex>0 then
    04862 ** the right-hand side of the corresponding aConstraint[] is evaluated
    04863 ** and becomes the argvIndex-th entry in argv.  ^(If aConstraintUsage[].omit
    04864 ** is true, then the constraint is assumed to be fully handled by the
    04865 ** virtual table and is not checked again by SQLite.)^
    04866 **
    04867 ** ^The idxNum and idxPtr values are recorded and passed into the
    04868 ** [xFilter] method.
    04869 ** ^[sqlite3_free()] is used to free idxPtr if and only if
    04870 ** needToFreeIdxPtr is true.
    04871 **
    04872 ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in
    04873 ** the correct order to satisfy the ORDER BY clause so that no separate
    04874 ** sorting step is required.
    04875 **
    04876 ** ^The estimatedCost value is an estimate of the cost of doing the
    04877 ** particular lookup.  A full scan of a table with N entries should have
    04878 ** a cost of N.  A binary search of a table of N entries should have a
    04879 ** cost of approximately log(N).
    04880 */
    04881 struct sqlite3_index_info {
    04882   /* Inputs */
    04883   int nConstraint;           /* Number of entries in aConstraint */
    04884   struct sqlite3_index_constraint {
    04885      int iColumn;              /* Column on left-hand side of constraint */
    04886      unsigned char op;         /* Constraint operator */
    04887      unsigned char usable;     /* True if this constraint is usable */
    04888      int iTermOffset;          /* Used internally - xBestIndex should ignore */
    04889   } *aConstraint;            /* Table of WHERE clause constraints */
    04890   int nOrderBy;              /* Number of terms in the ORDER BY clause */
    04891   struct sqlite3_index_orderby {
    04892      int iColumn;              /* Column number */
    04893      unsigned char desc;       /* True for DESC.  False for ASC. */
    04894   } *aOrderBy;               /* The ORDER BY clause */
    04895   /* Outputs */
    04896   struct sqlite3_index_constraint_usage {
    04897     int argvIndex;           /* if >0, constraint is part of argv to xFilter */
    04898     unsigned char omit;      /* Do not code a test for this constraint */
    04899   } *aConstraintUsage;
    04900   int idxNum;                /* Number used to identify the index */
    04901   char *idxStr;              /* String, possibly obtained from sqlite3_malloc */
    04902   int needToFreeIdxStr;      /* Free idxStr using sqlite3_free() if true */
    04903   int orderByConsumed;       /* True if output is already ordered */
    04904   double estimatedCost;      /* Estimated cost of using this index */
    04905 };
    04906
    04907 /*
    04908 ** CAPI3REF: Virtual Table Constraint Operator Codes
    04909 **
    04910 ** These macros defined the allowed values for the
    04911 ** [sqlite3_index_info].aConstraint[].op field.  Each value represents
    04912 ** an operator that is part of a constraint term in the wHERE clause of
    04913 ** a query that uses a [virtual table].
    04914 */
    04915 #define SQLITE_INDEX_CONSTRAINT_EQ    2
    04916 #define SQLITE_INDEX_CONSTRAINT_GT    4
    04917 #define SQLITE_INDEX_CONSTRAINT_LE    8
    04918 #define SQLITE_INDEX_CONSTRAINT_LT    16
    04919 #define SQLITE_INDEX_CONSTRAINT_GE    32
    04920 #define SQLITE_INDEX_CONSTRAINT_MATCH 64
    04921
    04922 /*
    04923 ** CAPI3REF: Register A Virtual Table Implementation
    04924 **
    04925 ** ^These routines are used to register a new [virtual table module] name.
    04926 ** ^Module names must be registered before
    04927 ** creating a new [virtual table] using the module and before using a
    04928 ** preexisting [virtual table] for the module.
    04929 **
    04930 ** ^The module name is registered on the [database connection] specified
    04931 ** by the first parameter.  ^The name of the module is given by the
    04932 ** second parameter.  ^The third parameter is a pointer to
    04933 ** the implementation of the [virtual table module].   ^The fourth
    04934 ** parameter is an arbitrary client data pointer that is passed through
    04935 ** into the [xCreate] and [xConnect] methods of the virtual table module
    04936 ** when a new virtual table is be being created or reinitialized.
    04937 **
    04938 ** ^The sqlite3_create_module_v2() interface has a fifth parameter which
    04939 ** is a pointer to a destructor for the pClientData.  ^SQLite will
    04940 ** invoke the destructor function (if it is not NULL) when SQLite
    04941 ** no longer needs the pClientData pointer.  ^The destructor will also
    04942 ** be invoked if the call to sqlite3_create_module_v2() fails.
    04943 ** ^The sqlite3_create_module()
    04944 ** interface is equivalent to sqlite3_create_module_v2() with a NULL
    04945 ** destructor.
    04946 */
    04947 SQLITE_API int sqlite3_create_module(
    04948   sqlite3 *db,               /* SQLite connection to register module with */
    04949   const char *zName,         /* Name of the module */
    04950   const sqlite3_module *p,   /* Methods for the module */
    04951   void *pClientData          /* Client data for xCreate/xConnect */
    04952 );
    04953 SQLITE_API int sqlite3_create_module_v2(
    04954   sqlite3 *db,               /* SQLite connection to register module with */
    04955   const char *zName,         /* Name of the module */
    04956   const sqlite3_module *p,   /* Methods for the module */
    04957   void *pClientData,         /* Client data for xCreate/xConnect */
    04958   void(*xDestroy)(void*)     /* Module destructor function */
    04959 );
    04960
    04961 /*
    04962 ** CAPI3REF: Virtual Table Instance Object
    04963 ** KEYWORDS: sqlite3_vtab
    04964 **
    04965 ** Every [virtual table module] implementation uses a subclass
    04966 ** of this object to describe a particular instance
    04967 ** of the [virtual table].  Each subclass will
    04968 ** be tailored to the specific needs of the module implementation.
    04969 ** The purpose of this superclass is to define certain fields that are
    04970 ** common to all module implementations.
    04971 **
    04972 ** ^Virtual tables methods can set an error message by assigning a
    04973 ** string obtained from [sqlite3_mprintf()] to zErrMsg.  The method should
    04974 ** take care that any prior string is freed by a call to [sqlite3_free()]
    04975 ** prior to assigning a new string to zErrMsg.  ^After the error message
    04976 ** is delivered up to the client application, the string will be automatically
    04977 ** freed by sqlite3_free() and the zErrMsg field will be zeroed.
    04978 */
    04979 struct sqlite3_vtab {
    04980   const sqlite3_module *pModule;  /* The module for this virtual table */
    04981   int nRef;                       /* NO LONGER USED */
    04982   char *zErrMsg;                  /* Error message from sqlite3_mprintf() */
    04983   /* Virtual table implementations will typically add additional fields */
    04984 };
    04985
    04986 /*
    04987 ** CAPI3REF: Virtual Table Cursor Object
    04988 ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
    04989 **
    04990 ** Every [virtual table module] implementation uses a subclass of the
    04991 ** following structure to describe cursors that point into the
    04992 ** [virtual table] and are used
    04993 ** to loop through the virtual table.  Cursors are created using the
    04994 ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
    04995 ** by the [sqlite3_module.xClose | xClose] method.  Cursors are used
    04996 ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
    04997 ** of the module.  Each module implementation will define
    04998 ** the content of a cursor structure to suit its own needs.
    04999 **
    05000 ** This superclass exists in order to define fields of the cursor that
    05001 ** are common to all implementations.
    05002 */
    05003 struct sqlite3_vtab_cursor {
    05004   sqlite3_vtab *pVtab;      /* Virtual table of this cursor */
    05005   /* Virtual table implementations will typically add additional fields */
    05006 };
    05007
    05008 /*
    05009 ** CAPI3REF: Declare The Schema Of A Virtual Table
    05010 **
    05011 ** ^The [xCreate] and [xConnect] methods of a
    05012 ** [virtual table module] call this interface
    05013 ** to declare the format (the names and datatypes of the columns) of
    05014 ** the virtual tables they implement.
    05015 */
    05016 SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL);
    05017
    05018 /*
    05019 ** CAPI3REF: Overload A Function For A Virtual Table
    05020 **
    05021 ** ^(Virtual tables can provide alternative implementations of functions
    05022 ** using the [xFindFunction] method of the [virtual table module].
    05023 ** But global versions of those functions
    05024 ** must exist in order to be overloaded.)^
    05025 **
    05026 ** ^(This API makes sure a global version of a function with a particular
    05027 ** name and number of parameters exists.  If no such function exists
    05028 ** before this API is called, a new function is created.)^  ^The implementation
    05029 ** of the new function always causes an exception to be thrown.  So
    05030 ** the new function is not good for anything by itself.  Its only
    05031 ** purpose is to be a placeholder function that can be overloaded
    05032 ** by a [virtual table].
    05033 */
    05034 SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
    05035
    05036 /*
    05037 ** The interface to the virtual-table mechanism defined above (back up
    05038 ** to a comment remarkably similar to this one) is currently considered
    05039 ** to be experimental.  The interface might change in incompatible ways.
    05040 ** If this is a problem for you, do not use the interface at this time.
    05041 **
    05042 ** When the virtual-table mechanism stabilizes, we will declare the
    05043 ** interface fixed, support it indefinitely, and remove this comment.
    05044 */
    05045
    05046 /*
    05047 ** CAPI3REF: A Handle To An Open BLOB
    05048 ** KEYWORDS: {BLOB handle} {BLOB handles}
    05049 **
    05050 ** An instance of this object represents an open BLOB on which
    05051 ** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
    05052 ** ^Objects of this type are created by [sqlite3_blob_open()]
    05053 ** and destroyed by [sqlite3_blob_close()].
    05054 ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
    05055 ** can be used to read or write small subsections of the BLOB.
    05056 ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
    05057 */
    05058 typedef struct sqlite3_blob sqlite3_blob;
    05059
    05060 /*
    05061 ** CAPI3REF: Open A BLOB For Incremental I/O
    05062 **
    05063 ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
    05064 ** in row iRow, column zColumn, table zTable in database zDb;
    05065 ** in other words, the same BLOB that would be selected by:
    05066 **
    05067 ** <pre>
    05068 **     SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
    05069 ** </pre>)^
    05070 **
    05071 ** ^If the flags parameter is non-zero, then the BLOB is opened for read
    05072 ** and write access. ^If it is zero, the BLOB is opened for read access.
    05073 ** ^It is not possible to open a column that is part of an index or primary
    05074 ** key for writing. ^If [foreign key constraints] are enabled, it is
    05075 ** not possible to open a column that is part of a [child key] for writing.
    05076 **
    05077 ** ^Note that the database name is not the filename that contains
    05078 ** the database but rather the symbolic name of the database that
    05079 ** appears after the AS keyword when the database is connected using [ATTACH].
    05080 ** ^For the main database file, the database name is "main".
    05081 ** ^For TEMP tables, the database name is "temp".
    05082 **
    05083 ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is written
    05084 ** to *ppBlob. Otherwise an [error code] is returned and *ppBlob is set
    05085 ** to be a null pointer.)^
    05086 ** ^This function sets the [database connection] error code and message
    05087 ** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()] and related
    05088 ** functions. ^Note that the *ppBlob variable is always initialized in a
    05089 ** way that makes it safe to invoke [sqlite3_blob_close()] on *ppBlob
    05090 ** regardless of the success or failure of this routine.
    05091 **
    05092 ** ^(If the row that a BLOB handle points to is modified by an
    05093 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
    05094 ** then the BLOB handle is marked as "expired".
    05095 ** This is true if any column of the row is changed, even a column
    05096 ** other than the one the BLOB handle is open on.)^
    05097 ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
    05098 ** an expired BLOB handle fail with a return code of [SQLITE_ABORT].
    05099 ** ^(Changes written into a BLOB prior to the BLOB expiring are not
    05100 ** rolled back by the expiration of the BLOB.  Such changes will eventually
    05101 ** commit if the transaction continues to completion.)^
    05102 **
    05103 ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
    05104 ** the opened blob.  ^The size of a blob may not be changed by this
    05105 ** interface.  Use the [UPDATE] SQL command to change the size of a
    05106 ** blob.
    05107 **
    05108 ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
    05109 ** and the built-in [zeroblob] SQL function can be used, if desired,
    05110 ** to create an empty, zero-filled blob in which to read or write using
    05111 ** this interface.
    05112 **
    05113 ** To avoid a resource leak, every open [BLOB handle] should eventually
    05114 ** be released by a call to [sqlite3_blob_close()].
    05115 */
    05116 SQLITE_API int sqlite3_blob_open(
    05117   sqlite3*,
    05118   const char *zDb,
    05119   const char *zTable,
    05120   const char *zColumn,
    05121   sqlite3_int64 iRow,
    05122   int flags,
    05123   sqlite3_blob **ppBlob
    05124 );
    05125
    05126 /*
    05127 ** CAPI3REF: Move a BLOB Handle to a New Row
    05128 **
    05129 ** ^This function is used to move an existing blob handle so that it points
    05130 ** to a different row of the same database table. ^The new row is identified
    05131 ** by the rowid value passed as the second argument. Only the row can be
    05132 ** changed. ^The database, table and column on which the blob handle is open
    05133 ** remain the same. Moving an existing blob handle to a new row can be
    05134 ** faster than closing the existing handle and opening a new one.
    05135 **
    05136 ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -
    05137 ** it must exist and there must be either a blob or text value stored in
    05138 ** the nominated column.)^ ^If the new row is not present in the table, or if
    05139 ** it does not contain a blob or text value, or if another error occurs, an
    05140 ** SQLite error code is returned and the blob handle is considered aborted.
    05141 ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or
    05142 ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return
    05143 ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle
    05144 ** always returns zero.
    05145 **
    05146 ** ^This function sets the database handle error code and message.
    05147 */
    05148 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);
    05149
    05150 /*
    05151 ** CAPI3REF: Close A BLOB Handle
    05152 **
    05153 ** ^Closes an open [BLOB handle].
    05154 **
    05155 ** ^Closing a BLOB shall cause the current transaction to commit
    05156 ** if there are no other BLOBs, no pending prepared statements, and the
    05157 ** database connection is in [autocommit mode].
    05158 ** ^If any writes were made to the BLOB, they might be held in cache
    05159 ** until the close operation if they will fit.
    05160 **
    05161 ** ^(Closing the BLOB often forces the changes
    05162 ** out to disk and so if any I/O errors occur, they will likely occur
    05163 ** at the time when the BLOB is closed.  Any errors that occur during
    05164 ** closing are reported as a non-zero return value.)^
    05165 **
    05166 ** ^(The BLOB is closed unconditionally.  Even if this routine returns
    05167 ** an error code, the BLOB is still closed.)^
    05168 **
    05169 ** ^Calling this routine with a null pointer (such as would be returned
    05170 ** by a failed call to [sqlite3_blob_open()]) is a harmless no-op.
    05171 */
    05172 SQLITE_API int sqlite3_blob_close(sqlite3_blob *);
    05173
    05174 /*
    05175 ** CAPI3REF: Return The Size Of An Open BLOB
    05176 **
    05177 ** ^Returns the size in bytes of the BLOB accessible via the
    05178 ** successfully opened [BLOB handle] in its only argument.  ^The
    05179 ** incremental blob I/O routines can only read or overwriting existing
    05180 ** blob content; they cannot change the size of a blob.
    05181 **
    05182 ** This routine only works on a [BLOB handle] which has been created
    05183 ** by a prior successful call to [sqlite3_blob_open()] and which has not
    05184 ** been closed by [sqlite3_blob_close()].  Passing any other pointer in
    05185 ** to this routine results in undefined and probably undesirable behavior.
    05186 */
    05187 SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *);
    05188
    05189 /*
    05190 ** CAPI3REF: Read Data From A BLOB Incrementally
    05191 **
    05192 ** ^(This function is used to read data from an open [BLOB handle] into a
    05193 ** caller-supplied buffer. N bytes of data are copied into buffer Z
    05194 ** from the open BLOB, starting at offset iOffset.)^
    05195 **
    05196 ** ^If offset iOffset is less than N bytes from the end of the BLOB,
    05197 ** [SQLITE_ERROR] is returned and no data is read.  ^If N or iOffset is
    05198 ** less than zero, [SQLITE_ERROR] is returned and no data is read.
    05199 ** ^The size of the blob (and hence the maximum value of N+iOffset)
    05200 ** can be determined using the [sqlite3_blob_bytes()] interface.
    05201 **
    05202 ** ^An attempt to read from an expired [BLOB handle] fails with an
    05203 ** error code of [SQLITE_ABORT].
    05204 **
    05205 ** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
    05206 ** Otherwise, an [error code] or an [extended error code] is returned.)^
    05207 **
    05208 ** This routine only works on a [BLOB handle] which has been created
    05209 ** by a prior successful call to [sqlite3_blob_open()] and which has not
    05210 ** been closed by [sqlite3_blob_close()].  Passing any other pointer in
    05211 ** to this routine results in undefined and probably undesirable behavior.
    05212 **
    05213 ** See also: [sqlite3_blob_write()].
    05214 */
    05215 SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
    05216
    05217 /*
    05218 ** CAPI3REF: Write Data Into A BLOB Incrementally
    05219 **
    05220 ** ^This function is used to write data into an open [BLOB handle] from a
    05221 ** caller-supplied buffer. ^N bytes of data are copied from the buffer Z
    05222 ** into the open BLOB, starting at offset iOffset.
    05223 **
    05224 ** ^If the [BLOB handle] passed as the first argument was not opened for
    05225 ** writing (the flags parameter to [sqlite3_blob_open()] was zero),
    05226 ** this function returns [SQLITE_READONLY].
    05227 **
    05228 ** ^This function may only modify the contents of the BLOB; it is
    05229 ** not possible to increase the size of a BLOB using this API.
    05230 ** ^If offset iOffset is less than N bytes from the end of the BLOB,
    05231 ** [SQLITE_ERROR] is returned and no data is written.  ^If N is
    05232 ** less than zero [SQLITE_ERROR] is returned and no data is written.
    05233 ** The size of the BLOB (and hence the maximum value of N+iOffset)
    05234 ** can be determined using the [sqlite3_blob_bytes()] interface.
    05235 **
    05236 ** ^An attempt to write to an expired [BLOB handle] fails with an
    05237 ** error code of [SQLITE_ABORT].  ^Writes to the BLOB that occurred
    05238 ** before the [BLOB handle] expired are not rolled back by the
    05239 ** expiration of the handle, though of course those changes might
    05240 ** have been overwritten by the statement that expired the BLOB handle
    05241 ** or by other independent statements.
    05242 **
    05243 ** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
    05244 ** Otherwise, an  [error code] or an [extended error code] is returned.)^
    05245 **
    05246 ** This routine only works on a [BLOB handle] which has been created
    05247 ** by a prior successful call to [sqlite3_blob_open()] and which has not
    05248 ** been closed by [sqlite3_blob_close()].  Passing any other pointer in
    05249 ** to this routine results in undefined and probably undesirable behavior.
    05250 **
    05251 ** See also: [sqlite3_blob_read()].
    05252 */
    05253 SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
    05254
    05255 /*
    05256 ** CAPI3REF: Virtual File System Objects
    05257 **
    05258 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object
    05259 ** that SQLite uses to interact
    05260 ** with the underlying operating system.  Most SQLite builds come with a
    05261 ** single default VFS that is appropriate for the host computer.
    05262 ** New VFSes can be registered and existing VFSes can be unregistered.
    05263 ** The following interfaces are provided.
    05264 **
    05265 ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
    05266 ** ^Names are case sensitive.
    05267 ** ^Names are zero-terminated UTF-8 strings.
    05268 ** ^If there is no match, a NULL pointer is returned.
    05269 ** ^If zVfsName is NULL then the default VFS is returned.
    05270 **
    05271 ** ^New VFSes are registered with sqlite3_vfs_register().
    05272 ** ^Each new VFS becomes the default VFS if the makeDflt flag is set.
    05273 ** ^The same VFS can be registered multiple times without injury.
    05274 ** ^To make an existing VFS into the default VFS, register it again
    05275 ** with the makeDflt flag set.  If two different VFSes with the
    05276 ** same name are registered, the behavior is undefined.  If a
    05277 ** VFS is registered with a name that is NULL or an empty string,
    05278 ** then the behavior is undefined.
    05279 **
    05280 ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.
    05281 ** ^(If the default VFS is unregistered, another VFS is chosen as
    05282 ** the default.  The choice for the new VFS is arbitrary.)^
    05283 */
    05284 SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
    05285 SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
    05286 SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);
    05287
    05288 /*
    05289 ** CAPI3REF: Mutexes
    05290 **
    05291 ** The SQLite core uses these routines for thread
    05292 ** synchronization. Though they are intended for internal
    05293 ** use by SQLite, code that links against SQLite is
    05294 ** permitted to use any of these routines.
    05295 **
    05296 ** The SQLite source code contains multiple implementations
    05297 ** of these mutex routines.  An appropriate implementation
    05298 ** is selected automatically at compile-time.  ^(The following
    05299 ** implementations are available in the SQLite core:
    05300 **
    05301 ** <ul>
    05302 ** <li>   SQLITE_MUTEX_OS2
    05303 ** <li>   SQLITE_MUTEX_PTHREAD
    05304 ** <li>   SQLITE_MUTEX_W32
    05305 ** <li>   SQLITE_MUTEX_NOOP
    05306 ** </ul>)^
    05307 **
    05308 ** ^The SQLITE_MUTEX_NOOP implementation is a set of routines
    05309 ** that does no real locking and is appropriate for use in
    05310 ** a single-threaded application.  ^The SQLITE_MUTEX_OS2,
    05311 ** SQLITE_MUTEX_PTHREAD, and SQLITE_MUTEX_W32 implementations
    05312 ** are appropriate for use on OS/2, Unix, and Windows.
    05313 **
    05314 ** ^(If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
    05315 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
    05316 ** implementation is included with the library. In this case the
    05317 ** application must supply a custom mutex implementation using the
    05318 ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
    05319 ** before calling sqlite3_initialize() or any other public sqlite3_
    05320 ** function that calls sqlite3_initialize().)^
    05321 **
    05322 ** ^The sqlite3_mutex_alloc() routine allocates a new
    05323 ** mutex and returns a pointer to it. ^If it returns NULL
    05324 ** that means that a mutex could not be allocated.  ^SQLite
    05325 ** will unwind its stack and return an error.  ^(The argument
    05326 ** to sqlite3_mutex_alloc() is one of these integer constants:
    05327 **
    05328 ** <ul>
    05329 ** <li>  SQLITE_MUTEX_FAST
    05330 ** <li>  SQLITE_MUTEX_RECURSIVE
    05331 ** <li>  SQLITE_MUTEX_STATIC_MASTER
    05332 ** <li>  SQLITE_MUTEX_STATIC_MEM
    05333 ** <li>  SQLITE_MUTEX_STATIC_MEM2
    05334 ** <li>  SQLITE_MUTEX_STATIC_PRNG
    05335 ** <li>  SQLITE_MUTEX_STATIC_LRU
    05336 ** <li>  SQLITE_MUTEX_STATIC_LRU2
    05337 ** </ul>)^
    05338 **
    05339 ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
    05340 ** cause sqlite3_mutex_alloc() to create
    05341 ** a new mutex.  ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
    05342 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
    05343 ** The mutex implementation does not need to make a distinction
    05344 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
    05345 ** not want to.  ^SQLite will only request a recursive mutex in
    05346 ** cases where it really needs one.  ^If a faster non-recursive mutex
    05347 ** implementation is available on the host platform, the mutex subsystem
    05348 ** might return such a mutex in response to SQLITE_MUTEX_FAST.
    05349 **
    05350 ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
    05351 ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
    05352 ** a pointer to a static preexisting mutex.  ^Six static mutexes are
    05353 ** used by the current version of SQLite.  Future versions of SQLite
    05354 ** may add additional static mutexes.  Static mutexes are for internal
    05355 ** use by SQLite only.  Applications that use SQLite mutexes should
    05356 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
    05357 ** SQLITE_MUTEX_RECURSIVE.
    05358 **
    05359 ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
    05360 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
    05361 ** returns a different mutex on every call.  ^But for the static
    05362 ** mutex types, the same mutex is returned on every call that has
    05363 ** the same type number.
    05364 **
    05365 ** ^The sqlite3_mutex_free() routine deallocates a previously
    05366 ** allocated dynamic mutex.  ^SQLite is careful to deallocate every
    05367 ** dynamic mutex that it allocates.  The dynamic mutexes must not be in
    05368 ** use when they are deallocated.  Attempting to deallocate a static
    05369 ** mutex results in undefined behavior.  ^SQLite never deallocates
    05370 ** a static mutex.
    05371 **
    05372 ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
    05373 ** to enter a mutex.  ^If another thread is already within the mutex,
    05374 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
    05375 ** SQLITE_BUSY.  ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
    05376 ** upon successful entry.  ^(Mutexes created using
    05377 ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
    05378 ** In such cases the,
    05379 ** mutex must be exited an equal number of times before another thread
    05380 ** can enter.)^  ^(If the same thread tries to enter any other
    05381 ** kind of mutex more than once, the behavior is undefined.
    05382 ** SQLite will never exhibit
    05383 ** such behavior in its own use of mutexes.)^
    05384 **
    05385 ** ^(Some systems (for example, Windows 95) do not support the operation
    05386 ** implemented by sqlite3_mutex_try().  On those systems, sqlite3_mutex_try()
    05387 ** will always return SQLITE_BUSY.  The SQLite core only ever uses
    05388 ** sqlite3_mutex_try() as an optimization so this is acceptable behavior.)^
    05389 **
    05390 ** ^The sqlite3_mutex_leave() routine exits a mutex that was
    05391 ** previously entered by the same thread.   ^(The behavior
    05392 ** is undefined if the mutex is not currently entered by the
    05393 ** calling thread or is not currently allocated.  SQLite will
    05394 ** never do either.)^
    05395 **
    05396 ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or
    05397 ** sqlite3_mutex_leave() is a NULL pointer, then all three routines
    05398 ** behave as no-ops.
    05399 **
    05400 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
    05401 */
    05402 SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int);
    05403 SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*);
    05404 SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*);
    05405 SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*);
    05406 SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*);
    05407
    05408 /*
    05409 ** CAPI3REF: Mutex Methods Object
    05410 **
    05411 ** An instance of this structure defines the low-level routines
    05412 ** used to allocate and use mutexes.
    05413 **
    05414 ** Usually, the default mutex implementations provided by SQLite are
    05415 ** sufficient, however the user has the option of substituting a custom
    05416 ** implementation for specialized deployments or systems for which SQLite
    05417 ** does not provide a suitable implementation. In this case, the user
    05418 ** creates and populates an instance of this structure to pass
    05419 ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
    05420 ** Additionally, an instance of this structure can be used as an
    05421 ** output variable when querying the system for the current mutex
    05422 ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
    05423 **
    05424 ** ^The xMutexInit method defined by this structure is invoked as
    05425 ** part of system initialization by the sqlite3_initialize() function.
    05426 ** ^The xMutexInit routine is called by SQLite exactly once for each
    05427 ** effective call to [sqlite3_initialize()].
    05428 **
    05429 ** ^The xMutexEnd method defined by this structure is invoked as
    05430 ** part of system shutdown by the sqlite3_shutdown() function. The
    05431 ** implementation of this method is expected to release all outstanding
    05432 ** resources obtained by the mutex methods implementation, especially
    05433 ** those obtained by the xMutexInit method.  ^The xMutexEnd()
    05434 ** interface is invoked exactly once for each call to [sqlite3_shutdown()].
    05435 **
    05436 ** ^(The remaining seven methods defined by this structure (xMutexAlloc,
    05437 ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
    05438 ** xMutexNotheld) implement the following interfaces (respectively):
    05439 **
    05440 ** <ul>
    05441 **   <li>  [sqlite3_mutex_alloc()] </li>
    05442 **   <li>  [sqlite3_mutex_free()] </li>
    05443 **   <li>  [sqlite3_mutex_enter()] </li>
    05444 **   <li>  [sqlite3_mutex_try()] </li>
    05445 **   <li>  [sqlite3_mutex_leave()] </li>
    05446 **   <li>  [sqlite3_mutex_held()] </li>
    05447 **   <li>  [sqlite3_mutex_notheld()] </li>
    05448 ** </ul>)^
    05449 **
    05450 ** The only difference is that the public sqlite3_XXX functions enumerated
    05451 ** above silently ignore any invocations that pass a NULL pointer instead
    05452 ** of a valid mutex handle. The implementations of the methods defined
    05453 ** by this structure are not required to handle this case, the results
    05454 ** of passing a NULL pointer instead of a valid mutex handle are undefined
    05455 ** (i.e. it is acceptable to provide an implementation that segfaults if
    05456 ** it is passed a NULL pointer).
    05457 **
    05458 ** The xMutexInit() method must be threadsafe.  ^It must be harmless to
    05459 ** invoke xMutexInit() multiple times within the same process and without
    05460 ** intervening calls to xMutexEnd().  Second and subsequent calls to
    05461 ** xMutexInit() must be no-ops.
    05462 **
    05463 ** ^xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
    05464 ** and its associates).  ^Similarly, xMutexAlloc() must not use SQLite memory
    05465 ** allocation for a static mutex.  ^However xMutexAlloc() may use SQLite
    05466 ** memory allocation for a fast or recursive mutex.
    05467 **
    05468 ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
    05469 ** called, but only if the prior call to xMutexInit returned SQLITE_OK.
    05470 ** If xMutexInit fails in any way, it is expected to clean up after itself
    05471 ** prior to returning.
    05472 */
    05473 typedef struct sqlite3_mutex_methods sqlite3_mutex_methods;
    05474 struct sqlite3_mutex_methods {
    05475   int (*xMutexInit)(void);
    05476   int (*xMutexEnd)(void);
    05477   sqlite3_mutex *(*xMutexAlloc)(int);
    05478   void (*xMutexFree)(sqlite3_mutex *);
    05479   void (*xMutexEnter)(sqlite3_mutex *);
    05480   int (*xMutexTry)(sqlite3_mutex *);
    05481   void (*xMutexLeave)(sqlite3_mutex *);
    05482   int (*xMutexHeld)(sqlite3_mutex *);
    05483   int (*xMutexNotheld)(sqlite3_mutex *);
    05484 };
    05485
    05486 /*
    05487 ** CAPI3REF: Mutex Verification Routines
    05488 **
    05489 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
    05490 ** are intended for use inside assert() statements.  ^The SQLite core
    05491 ** never uses these routines except inside an assert() and applications
    05492 ** are advised to follow the lead of the core.  ^The SQLite core only
    05493 ** provides implementations for these routines when it is compiled
    05494 ** with the SQLITE_DEBUG flag.  ^External mutex implementations
    05495 ** are only required to provide these routines if SQLITE_DEBUG is
    05496 ** defined and if NDEBUG is not defined.
    05497 **
    05498 ** ^These routines should return true if the mutex in their argument
    05499 ** is held or not held, respectively, by the calling thread.
    05500 **
    05501 ** ^The implementation is not required to provided versions of these
    05502 ** routines that actually work. If the implementation does not provide working
    05503 ** versions of these routines, it should at least provide stubs that always
    05504 ** return true so that one does not get spurious assertion failures.
    05505 **
    05506 ** ^If the argument to sqlite3_mutex_held() is a NULL pointer then
    05507 ** the routine should return 1.   This seems counter-intuitive since
    05508 ** clearly the mutex cannot be held if it does not exist.  But
    05509 ** the reason the mutex does not exist is because the build is not
    05510 ** using mutexes.  And we do not want the assert() containing the
    05511 ** call to sqlite3_mutex_held() to fail, so a non-zero return is
    05512 ** the appropriate thing to do.  ^The sqlite3_mutex_notheld()
    05513 ** interface should also return 1 when given a NULL pointer.
    05514 */
    05515 #ifndef NDEBUG
    05516 SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*);
    05517 SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*);
    05518 #endif
    05519
    05520 /*
    05521 ** CAPI3REF: Mutex Types
    05522 **
    05523 ** The [sqlite3_mutex_alloc()] interface takes a single argument
    05524 ** which is one of these integer constants.
    05525 **
    05526 ** The set of static mutexes may change from one SQLite release to the
    05527 ** next.  Applications that override the built-in mutex logic must be
    05528 ** prepared to accommodate additional static mutexes.
    05529 */
    05530 #define SQLITE_MUTEX_FAST             0
    05531 #define SQLITE_MUTEX_RECURSIVE        1
    05532 #define SQLITE_MUTEX_STATIC_MASTER    2
    05533 #define SQLITE_MUTEX_STATIC_MEM       3  /* sqlite3_malloc() */
    05534 #define SQLITE_MUTEX_STATIC_MEM2      4  /* NOT USED */
    05535 #define SQLITE_MUTEX_STATIC_OPEN      4  /* sqlite3BtreeOpen() */
    05536 #define SQLITE_MUTEX_STATIC_PRNG      5  /* sqlite3_random() */
    05537 #define SQLITE_MUTEX_STATIC_LRU       6  /* lru page list */
    05538 #define SQLITE_MUTEX_STATIC_LRU2      7  /* NOT USED */
    05539 #define SQLITE_MUTEX_STATIC_PMEM      7  /* sqlite3PageMalloc() */
    05540
    05541 /*
    05542 ** CAPI3REF: Retrieve the mutex for a database connection
    05543 **
    05544 ** ^This interface returns a pointer the [sqlite3_mutex] object that
    05545 ** serializes access to the [database connection] given in the argument
    05546 ** when the [threading mode] is Serialized.
    05547 ** ^If the [threading mode] is Single-thread or Multi-thread then this
    05548 ** routine returns a NULL pointer.
    05549 */
    05550 SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*);
    05551
    05552 /*
    05553 ** CAPI3REF: Low-Level Control Of Database Files
    05554 **
    05555 ** ^The [sqlite3_file_control()] interface makes a direct call to the
    05556 ** xFileControl method for the [sqlite3_io_methods] object associated
    05557 ** with a particular database identified by the second argument. ^The
    05558 ** name of the database is "main" for the main database or "temp" for the
    05559 ** TEMP database, or the name that appears after the AS keyword for
    05560 ** databases that are added using the [ATTACH] SQL command.
    05561 ** ^A NULL pointer can be used in place of "main" to refer to the
    05562 ** main database file.
    05563 ** ^The third and fourth parameters to this routine
    05564 ** are passed directly through to the second and third parameters of
    05565 ** the xFileControl method.  ^The return value of the xFileControl
    05566 ** method becomes the return value of this routine.
    05567 **
    05568 ** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes
    05569 ** a pointer to the underlying [sqlite3_file] object to be written into
    05570 ** the space pointed to by the 4th parameter.  ^The SQLITE_FCNTL_FILE_POINTER
    05571 ** case is a short-circuit path which does not actually invoke the
    05572 ** underlying sqlite3_io_methods.xFileControl method.
    05573 **
    05574 ** ^If the second parameter (zDbName) does not match the name of any
    05575 ** open database file, then SQLITE_ERROR is returned.  ^This error
    05576 ** code is not remembered and will not be recalled by [sqlite3_errcode()]
    05577 ** or [sqlite3_errmsg()].  The underlying xFileControl method might
    05578 ** also return SQLITE_ERROR.  There is no way to distinguish between
    05579 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying
    05580 ** xFileControl method.
    05581 **
    05582 ** See also: [SQLITE_FCNTL_LOCKSTATE]
    05583 */
    05584 SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);
    05585
    05586 /*
    05587 ** CAPI3REF: Testing Interface
    05588 **
    05589 ** ^The sqlite3_test_control() interface is used to read out internal
    05590 ** state of SQLite and to inject faults into SQLite for testing
    05591 ** purposes.  ^The first parameter is an operation code that determines
    05592 ** the number, meaning, and operation of all subsequent parameters.
    05593 **
    05594 ** This interface is not for use by applications.  It exists solely
    05595 ** for verifying the correct operation of the SQLite library.  Depending
    05596 ** on how the SQLite library is compiled, this interface might not exist.
    05597 **
    05598 ** The details of the operation codes, their meanings, the parameters
    05599 ** they take, and what they do are all subject to change without notice.
    05600 ** Unlike most of the SQLite API, this function is not guaranteed to
    05601 ** operate consistently from one release to the next.
    05602 */
    05603 SQLITE_API int sqlite3_test_control(int op, ...);
    05604
    05605 /*
    05606 ** CAPI3REF: Testing Interface Operation Codes
    05607 **
    05608 ** These constants are the valid operation code parameters used
    05609 ** as the first argument to [sqlite3_test_control()].
    05610 **
    05611 ** These parameters and their meanings are subject to change
    05612 ** without notice.  These values are for testing purposes only.
    05613 ** Applications should not use any of these parameters or the
    05614 ** [sqlite3_test_control()] interface.
    05615 */
    05616 #define SQLITE_TESTCTRL_FIRST                    5
    05617 #define SQLITE_TESTCTRL_PRNG_SAVE                5
    05618 #define SQLITE_TESTCTRL_PRNG_RESTORE             6
    05619 #define SQLITE_TESTCTRL_PRNG_RESET               7
    05620 #define SQLITE_TESTCTRL_BITVEC_TEST              8
    05621 #define SQLITE_TESTCTRL_FAULT_INSTALL            9
    05622 #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS     10
    05623 #define SQLITE_TESTCTRL_PENDING_BYTE            11
    05624 #define SQLITE_TESTCTRL_ASSERT                  12
    05625 #define SQLITE_TESTCTRL_ALWAYS                  13
    05626 #define SQLITE_TESTCTRL_RESERVE                 14
    05627 #define SQLITE_TESTCTRL_OPTIMIZATIONS           15
    05628 #define SQLITE_TESTCTRL_ISKEYWORD               16
    05629 #define SQLITE_TESTCTRL_PGHDRSZ                 17
    05630 #define SQLITE_TESTCTRL_SCRATCHMALLOC           18
    05631 #define SQLITE_TESTCTRL_LOCALTIME_FAULT         19
    05632 #define SQLITE_TESTCTRL_LAST                    19
    05633
    05634 /*
    05635 ** CAPI3REF: SQLite Runtime Status
    05636 **
    05637 ** ^This interface is used to retrieve runtime status information
    05638 ** about the performance of SQLite, and optionally to reset various
    05639 ** highwater marks.  ^The first argument is an integer code for
    05640 ** the specific parameter to measure.  ^(Recognized integer codes
    05641 ** are of the form [status parameters | SQLITE_STATUS_...].)^
    05642 ** ^The current value of the parameter is returned into *pCurrent.
    05643 ** ^The highest recorded value is returned in *pHighwater.  ^If the
    05644 ** resetFlag is true, then the highest record value is reset after
    05645 ** *pHighwater is written.  ^(Some parameters do not record the highest
    05646 ** value.  For those parameters
    05647 ** nothing is written into *pHighwater and the resetFlag is ignored.)^
    05648 ** ^(Other parameters record only the highwater mark and not the current
    05649 ** value.  For these latter parameters nothing is written into *pCurrent.)^
    05650 **
    05651 ** ^The sqlite3_status() routine returns SQLITE_OK on success and a
    05652 ** non-zero [error code] on failure.
    05653 **
    05654 ** This routine is threadsafe but is not atomic.  This routine can be
    05655 ** called while other threads are running the same or different SQLite
    05656 ** interfaces.  However the values returned in *pCurrent and
    05657 ** *pHighwater reflect the status of SQLite at different points in time
    05658 ** and it is possible that another thread might change the parameter
    05659 ** in between the times when *pCurrent and *pHighwater are written.
    05660 **
    05661 ** See also: [sqlite3_db_status()]
    05662 */
    05663 SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);
    05664
    05665
    05666 /*
    05667 ** CAPI3REF: Status Parameters
    05668 ** KEYWORDS: {status parameters}
    05669 **
    05670 ** These integer constants designate various run-time status parameters
    05671 ** that can be returned by [sqlite3_status()].
    05672 **
    05673 ** <dl>
    05674 ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt>
    05675 ** <dd>This parameter is the current amount of memory checked out
    05676 ** using [sqlite3_malloc()], either directly or indirectly.  The
    05677 ** figure includes calls made to [sqlite3_malloc()] by the application
    05678 ** and internal memory usage by the SQLite library.  Scratch memory
    05679 ** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache
    05680 ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
    05681 ** this parameter.  The amount returned is the sum of the allocation
    05682 ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^
    05683 **
    05684 ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt>
    05685 ** <dd>This parameter records the largest memory allocation request
    05686 ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
    05687 ** internal equivalents).  Only the value returned in the
    05688 ** *pHighwater parameter to [sqlite3_status()] is of interest.
    05689 ** The value written into the *pCurrent parameter is undefined.</dd>)^
    05690 **
    05691 ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt>
    05692 ** <dd>This parameter records the number of separate memory allocations
    05693 ** currently checked out.</dd>)^
    05694 **
    05695 ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt>
    05696 ** <dd>This parameter returns the number of pages used out of the
    05697 ** [pagecache memory allocator] that was configured using
    05698 ** [SQLITE_CONFIG_PAGECACHE].  The
    05699 ** value returned is in pages, not in bytes.</dd>)^
    05700 **
    05701 ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]]
    05702 ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>
    05703 ** <dd>This parameter returns the number of bytes of page cache
    05704 ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE]
    05705 ** buffer and where forced to overflow to [sqlite3_malloc()].  The
    05706 ** returned value includes allocations that overflowed because they
    05707 ** where too large (they were larger than the "sz" parameter to
    05708 ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
    05709 ** no space was left in the page cache.</dd>)^
    05710 **
    05711 ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>
    05712 ** <dd>This parameter records the largest memory allocation request
    05713 ** handed to [pagecache memory allocator].  Only the value returned in the
    05714 ** *pHighwater parameter to [sqlite3_status()] is of interest.
    05715 ** The value written into the *pCurrent parameter is undefined.</dd>)^
    05716 **
    05717 ** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt>
    05718 ** <dd>This parameter returns the number of allocations used out of the
    05719 ** [scratch memory allocator] configured using
    05720 ** [SQLITE_CONFIG_SCRATCH].  The value returned is in allocations, not
    05721 ** in bytes.  Since a single thread may only have one scratch allocation
    05722 ** outstanding at time, this parameter also reports the number of threads
    05723 ** using scratch memory at the same time.</dd>)^
    05724 **
    05725 ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>
    05726 ** <dd>This parameter returns the number of bytes of scratch memory
    05727 ** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH]
    05728 ** buffer and where forced to overflow to [sqlite3_malloc()].  The values
    05729 ** returned include overflows because the requested allocation was too
    05730 ** larger (that is, because the requested allocation was larger than the
    05731 ** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer
    05732 ** slots were available.
    05733 ** </dd>)^
    05734 **
    05735 ** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt>
    05736 ** <dd>This parameter records the largest memory allocation request
    05737 ** handed to [scratch memory allocator].  Only the value returned in the
    05738 ** *pHighwater parameter to [sqlite3_status()] is of interest.
    05739 ** The value written into the *pCurrent parameter is undefined.</dd>)^
    05740 **
    05741 ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt>
    05742 ** <dd>This parameter records the deepest parser stack.  It is only
    05743 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
    05744 ** </dl>
    05745 **
    05746 ** New status parameters may be added from time to time.
    05747 */
    05748 #define SQLITE_STATUS_MEMORY_USED          0
    05749 #define SQLITE_STATUS_PAGECACHE_USED       1
    05750 #define SQLITE_STATUS_PAGECACHE_OVERFLOW   2
    05751 #define SQLITE_STATUS_SCRATCH_USED         3
    05752 #define SQLITE_STATUS_SCRATCH_OVERFLOW     4
    05753 #define SQLITE_STATUS_MALLOC_SIZE          5
    05754 #define SQLITE_STATUS_PARSER_STACK         6
    05755 #define SQLITE_STATUS_PAGECACHE_SIZE       7
    05756 #define SQLITE_STATUS_SCRATCH_SIZE         8
    05757 #define SQLITE_STATUS_MALLOC_COUNT         9
    05758
    05759 /*
    05760 ** CAPI3REF: Database Connection Status
    05761 **
    05762 ** ^This interface is used to retrieve runtime status information
    05763 ** about a single [database connection].  ^The first argument is the
    05764 ** database connection object to be interrogated.  ^The second argument
    05765 ** is an integer constant, taken from the set of
    05766 ** [SQLITE_DBSTATUS options], that
    05767 ** determines the parameter to interrogate.  The set of
    05768 ** [SQLITE_DBSTATUS options] is likely
    05769 ** to grow in future releases of SQLite.
    05770 **
    05771 ** ^The current value of the requested parameter is written into *pCur
    05772 ** and the highest instantaneous value is written into *pHiwtr.  ^If
    05773 ** the resetFlg is true, then the highest instantaneous value is
    05774 ** reset back down to the current value.
    05775 **
    05776 ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a
    05777 ** non-zero [error code] on failure.
    05778 **
    05779 ** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
    05780 */
    05781 SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
    05782
    05783 /*
    05784 ** CAPI3REF: Status Parameters for database connections
    05785 ** KEYWORDS: {SQLITE_DBSTATUS options}
    05786 **
    05787 ** These constants are the available integer "verbs" that can be passed as
    05788 ** the second argument to the [sqlite3_db_status()] interface.
    05789 **
    05790 ** New verbs may be added in future releases of SQLite. Existing verbs
    05791 ** might be discontinued. Applications should check the return code from
    05792 ** [sqlite3_db_status()] to make sure that the call worked.
    05793 ** The [sqlite3_db_status()] interface will return a non-zero error code
    05794 ** if a discontinued or unsupported verb is invoked.
    05795 **
    05796 ** <dl>
    05797 ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
    05798 ** <dd>This parameter returns the number of lookaside memory slots currently
    05799 ** checked out.</dd>)^
    05800 **
    05801 ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt>
    05802 ** <dd>This parameter returns the number malloc attempts that were
    05803 ** satisfied using lookaside memory. Only the high-water value is meaningful;
    05804 ** the current value is always zero.)^
    05805 **
    05806 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]]
    05807 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt>
    05808 ** <dd>This parameter returns the number malloc attempts that might have
    05809 ** been satisfied using lookaside memory but failed due to the amount of
    05810 ** memory requested being larger than the lookaside slot size.
    05811 ** Only the high-water value is meaningful;
    05812 ** the current value is always zero.)^
    05813 **
    05814 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]]
    05815 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt>
    05816 ** <dd>This parameter returns the number malloc attempts that might have
    05817 ** been satisfied using lookaside memory but failed due to all lookaside
    05818 ** memory already being in use.
    05819 ** Only the high-water value is meaningful;
    05820 ** the current value is always zero.)^
    05821 **
    05822 ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt>
    05823 ** <dd>This parameter returns the approximate number of of bytes of heap
    05824 ** memory used by all pager caches associated with the database connection.)^
    05825 ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
    05826 **
    05827 ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt>
    05828 ** <dd>This parameter returns the approximate number of of bytes of heap
    05829 ** memory used to store the schema for all databases associated
    05830 ** with the connection - main, temp, and any [ATTACH]-ed databases.)^
    05831 ** ^The full amount of memory used by the schemas is reported, even if the
    05832 ** schema memory is shared with other database connections due to
    05833 ** [shared cache mode] being enabled.
    05834 ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.
    05835 **
    05836 ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt>
    05837 ** <dd>This parameter returns the approximate number of of bytes of heap
    05838 ** and lookaside memory used by all prepared statements associated with
    05839 ** the database connection.)^
    05840 ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
    05841 ** </dd>
    05842 **
    05843 ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt>
    05844 ** <dd>This parameter returns the number of pager cache hits that have
    05845 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT
    05846 ** is always 0.
    05847 ** </dd>
    05848 **
    05849 ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt>
    05850 ** <dd>This parameter returns the number of pager cache misses that have
    05851 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS
    05852 ** is always 0.
    05853 ** </dd>
    05854 ** </dl>
    05855 */
    05856 #define SQLITE_DBSTATUS_LOOKASIDE_USED       0
    05857 #define SQLITE_DBSTATUS_CACHE_USED           1
    05858 #define SQLITE_DBSTATUS_SCHEMA_USED          2
    05859 #define SQLITE_DBSTATUS_STMT_USED            3
    05860 #define SQLITE_DBSTATUS_LOOKASIDE_HIT        4
    05861 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE  5
    05862 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL  6
    05863 #define SQLITE_DBSTATUS_CACHE_HIT            7
    05864 #define SQLITE_DBSTATUS_CACHE_MISS           8
    05865 #define SQLITE_DBSTATUS_MAX                  8   /* Largest defined DBSTATUS */
    05866
    05867
    05868 /*
    05869 ** CAPI3REF: Prepared Statement Status
    05870 **
    05871 ** ^(Each prepared statement maintains various
    05872 ** [SQLITE_STMTSTATUS counters] that measure the number
    05873 ** of times it has performed specific operations.)^  These counters can
    05874 ** be used to monitor the performance characteristics of the prepared
    05875 ** statements.  For example, if the number of table steps greatly exceeds
    05876 ** the number of table searches or result rows, that would tend to indicate
    05877 ** that the prepared statement is using a full table scan rather than
    05878 ** an index.
    05879 **
    05880 ** ^(This interface is used to retrieve and reset counter values from
    05881 ** a [prepared statement].  The first argument is the prepared statement
    05882 ** object to be interrogated.  The second argument
    05883 ** is an integer code for a specific [SQLITE_STMTSTATUS counter]
    05884 ** to be interrogated.)^
    05885 ** ^The current value of the requested counter is returned.
    05886 ** ^If the resetFlg is true, then the counter is reset to zero after this
    05887 ** interface call returns.
    05888 **
    05889 ** See also: [sqlite3_status()] and [sqlite3_db_status()].
    05890 */
    05891 SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
    05892
    05893 /*
    05894 ** CAPI3REF: Status Parameters for prepared statements
    05895 ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters}
    05896 **
    05897 ** These preprocessor macros define integer codes that name counter
    05898 ** values associated with the [sqlite3_stmt_status()] interface.
    05899 ** The meanings of the various counters are as follows:
    05900 **
    05901 ** <dl>
    05902 ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt>
    05903 ** <dd>^This is the number of times that SQLite has stepped forward in
    05904 ** a table as part of a full table scan.  Large numbers for this counter
    05905 ** may indicate opportunities for performance improvement through
    05906 ** careful use of indices.</dd>
    05907 **
    05908 ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt>
    05909 ** <dd>^This is the number of sort operations that have occurred.
    05910 ** A non-zero value in this counter may indicate an opportunity to
    05911 ** improvement performance through careful use of indices.</dd>
    05912 **
    05913 ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt>
    05914 ** <dd>^This is the number of rows inserted into transient indices that
    05915 ** were created automatically in order to help joins run faster.
    05916 ** A non-zero value in this counter may indicate an opportunity to
    05917 ** improvement performance by adding permanent indices that do not
    05918 ** need to be reinitialized each time the statement is run.</dd>
    05919 ** </dl>
    05920 */
    05921 #define SQLITE_STMTSTATUS_FULLSCAN_STEP     1
    05922 #define SQLITE_STMTSTATUS_SORT              2
    05923 #define SQLITE_STMTSTATUS_AUTOINDEX         3
    05924
    05925 /*
    05926 ** CAPI3REF: Custom Page Cache Object
    05927 **
    05928 ** The sqlite3_pcache type is opaque.  It is implemented by
    05929 ** the pluggable module.  The SQLite core has no knowledge of
    05930 ** its size or internal structure and never deals with the
    05931 ** sqlite3_pcache object except by holding and passing pointers
    05932 ** to the object.
    05933 **
    05934 ** See [sqlite3_pcache_methods] for additional information.
    05935 */
    05936 typedef struct sqlite3_pcache sqlite3_pcache;
    05937
    05938 /*
    05939 ** CAPI3REF: Application Defined Page Cache.
    05940 ** KEYWORDS: {page cache}
    05941 **
    05942 ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE], ...) interface can
    05943 ** register an alternative page cache implementation by passing in an
    05944 ** instance of the sqlite3_pcache_methods structure.)^
    05945 ** In many applications, most of the heap memory allocated by
    05946 ** SQLite is used for the page cache.
    05947 ** By implementing a
    05948 ** custom page cache using this API, an application can better control
    05949 ** the amount of memory consumed by SQLite, the way in which
    05950 ** that memory is allocated and released, and the policies used to
    05951 ** determine exactly which parts of a database file are cached and for
    05952 ** how long.
    05953 **
    05954 ** The alternative page cache mechanism is an
    05955 ** extreme measure that is only needed by the most demanding applications.
    05956 ** The built-in page cache is recommended for most uses.
    05957 **
    05958 ** ^(The contents of the sqlite3_pcache_methods structure are copied to an
    05959 ** internal buffer by SQLite within the call to [sqlite3_config].  Hence
    05960 ** the application may discard the parameter after the call to
    05961 ** [sqlite3_config()] returns.)^
    05962 **
    05963 ** [[the xInit() page cache method]]
    05964 ** ^(The xInit() method is called once for each effective
    05965 ** call to [sqlite3_initialize()])^
    05966 ** (usually only once during the lifetime of the process). ^(The xInit()
    05967 ** method is passed a copy of the sqlite3_pcache_methods.pArg value.)^
    05968 ** The intent of the xInit() method is to set up global data structures
    05969 ** required by the custom page cache implementation.
    05970 ** ^(If the xInit() method is NULL, then the
    05971 ** built-in default page cache is used instead of the application defined
    05972 ** page cache.)^
    05973 **
    05974 ** [[the xShutdown() page cache method]]
    05975 ** ^The xShutdown() method is called by [sqlite3_shutdown()].
    05976 ** It can be used to clean up
    05977 ** any outstanding resources before process shutdown, if required.
    05978 ** ^The xShutdown() method may be NULL.
    05979 **
    05980 ** ^SQLite automatically serializes calls to the xInit method,
    05981 ** so the xInit method need not be threadsafe.  ^The
    05982 ** xShutdown method is only called from [sqlite3_shutdown()] so it does
    05983 ** not need to be threadsafe either.  All other methods must be threadsafe
    05984 ** in multithreaded applications.
    05985 **
    05986 ** ^SQLite will never invoke xInit() more than once without an intervening
    05987 ** call to xShutdown().
    05988 **
    05989 ** [[the xCreate() page cache methods]]
    05990 ** ^SQLite invokes the xCreate() method to construct a new cache instance.
    05991 ** SQLite will typically create one cache instance for each open database file,
    05992 ** though this is not guaranteed. ^The
    05993 ** first parameter, szPage, is the size in bytes of the pages that must
    05994 ** be allocated by the cache.  ^szPage will not be a power of two.  ^szPage
    05995 ** will the page size of the database file that is to be cached plus an
    05996 ** increment (here called "R") of less than 250.  SQLite will use the
    05997 ** extra R bytes on each page to store metadata about the underlying
    05998 ** database page on disk.  The value of R depends
    05999 ** on the SQLite version, the target platform, and how SQLite was compiled.
    06000 ** ^(R is constant for a particular build of SQLite. Except, there are two
    06001 ** distinct values of R when SQLite is compiled with the proprietary
    06002 ** ZIPVFS extension.)^  ^The second argument to
    06003 ** xCreate(), bPurgeable, is true if the cache being created will
    06004 ** be used to cache database pages of a file stored on disk, or
    06005 ** false if it is used for an in-memory database. The cache implementation
    06006 ** does not have to do anything special based with the value of bPurgeable;
    06007 ** it is purely advisory.  ^On a cache where bPurgeable is false, SQLite will
    06008 ** never invoke xUnpin() except to deliberately delete a page.
    06009 ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to
    06010 ** false will always have the "discard" flag set to true.
    06011 ** ^Hence, a cache created with bPurgeable false will
    06012 ** never contain any unpinned pages.
    06013 **
    06014 ** [[the xCachesize() page cache method]]
    06015 ** ^(The xCachesize() method may be called at any time by SQLite to set the
    06016 ** suggested maximum cache-size (number of pages stored by) the cache
    06017 ** instance passed as the first argument. This is the value configured using
    06018 ** the SQLite "[PRAGMA cache_size]" command.)^  As with the bPurgeable
    06019 ** parameter, the implementation is not required to do anything with this
    06020 ** value; it is advisory only.
    06021 **
    06022 ** [[the xPagecount() page cache methods]]
    06023 ** The xPagecount() method must return the number of pages currently
    06024 ** stored in the cache, both pinned and unpinned.
    06025 **
    06026 ** [[the xFetch() page cache methods]]
    06027 ** The xFetch() method locates a page in the cache and returns a pointer to
    06028 ** the page, or a NULL pointer.
    06029 ** A "page", in this context, means a buffer of szPage bytes aligned at an
    06030 ** 8-byte boundary. The page to be fetched is determined by the key. ^The
    06031 ** minimum key value is 1.  After it has been retrieved using xFetch, the page
    06032 ** is considered to be "pinned".
    06033 **
    06034 ** If the requested page is already in the page cache, then the page cache
    06035 ** implementation must return a pointer to the page buffer with its content
    06036 ** intact.  If the requested page is not already in the cache, then the
    06037 ** cache implementation should use the value of the createFlag
    06038 ** parameter to help it determined what action to take:
    06039 **
    06040 ** <table border=1 width=85% align=center>
    06041 ** <tr><th> createFlag <th> Behaviour when page is not already in cache
    06042 ** <tr><td> 0 <td> Do not allocate a new page.  Return NULL.
    06043 ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so.
    06044 **                 Otherwise return NULL.
    06045 ** <tr><td> 2 <td> Make every effort to allocate a new page.  Only return
    06046 **                 NULL if allocating a new page is effectively impossible.
    06047 ** </table>
    06048 **
    06049 ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1.  SQLite
    06050 ** will only use a createFlag of 2 after a prior call with a createFlag of 1
    06051 ** failed.)^  In between the to xFetch() calls, SQLite may
    06052 ** attempt to unpin one or more cache pages by spilling the content of
    06053 ** pinned pages to disk and synching the operating system disk cache.
    06054 **
    06055 ** [[the xUnpin() page cache method]]
    06056 ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page
    06057 ** as its second argument.  If the third parameter, discard, is non-zero,
    06058 ** then the page must be evicted from the cache.
    06059 ** ^If the discard parameter is
    06060 ** zero, then the page may be discarded or retained at the discretion of
    06061 ** page cache implementation. ^The page cache implementation
    06062 ** may choose to evict unpinned pages at any time.
    06063 **
    06064 ** The cache must not perform any reference counting. A single
    06065 ** call to xUnpin() unpins the page regardless of the number of prior calls
    06066 ** to xFetch().
    06067 **
    06068 ** [[the xRekey() page cache methods]]
    06069 ** The xRekey() method is used to change the key value associated with the
    06070 ** page passed as the second argument. If the cache
    06071 ** previously contains an entry associated with newKey, it must be
    06072 ** discarded. ^Any prior cache entry associated with newKey is guaranteed not
    06073 ** to be pinned.
    06074 **
    06075 ** When SQLite calls the xTruncate() method, the cache must discard all
    06076 ** existing cache entries with page numbers (keys) greater than or equal
    06077 ** to the value of the iLimit parameter passed to xTruncate(). If any
    06078 ** of these pages are pinned, they are implicitly unpinned, meaning that
    06079 ** they can be safely discarded.
    06080 **
    06081 ** [[the xDestroy() page cache method]]
    06082 ** ^The xDestroy() method is used to delete a cache allocated by xCreate().
    06083 ** All resources associated with the specified cache should be freed. ^After
    06084 ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
    06085 ** handle invalid, and will not use it with any other sqlite3_pcache_methods
    06086 ** functions.
    06087 */
    06088 typedef struct sqlite3_pcache_methods sqlite3_pcache_methods;
    06089 struct sqlite3_pcache_methods {
    06090   void *pArg;
    06091   int (*xInit)(void*);
    06092   void (*xShutdown)(void*);
    06093   sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable);
    06094   void (*xCachesize)(sqlite3_pcache*, int nCachesize);
    06095   int (*xPagecount)(sqlite3_pcache*);
    06096   void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
    06097   void (*xUnpin)(sqlite3_pcache*, void*, int discard);
    06098   void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey);
    06099   void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
    06100   void (*xDestroy)(sqlite3_pcache*);
    06101 };
    06102
    06103 /*
    06104 ** CAPI3REF: Online Backup Object
    06105 **
    06106 ** The sqlite3_backup object records state information about an ongoing
    06107 ** online backup operation.  ^The sqlite3_backup object is created by
    06108 ** a call to [sqlite3_backup_init()] and is destroyed by a call to
    06109 ** [sqlite3_backup_finish()].
    06110 **
    06111 ** See Also: [Using the SQLite Online Backup API]
    06112 */
    06113 typedef struct sqlite3_backup sqlite3_backup;
    06114
    06115 /*
    06116 ** CAPI3REF: Online Backup API.
    06117 **
    06118 ** The backup API copies the content of one database into another.
    06119 ** It is useful either for creating backups of databases or
    06120 ** for copying in-memory databases to or from persistent files.
    06121 **
    06122 ** See Also: [Using the SQLite Online Backup API]
    06123 **
    06124 ** ^SQLite holds a write transaction open on the destination database file
    06125 ** for the duration of the backup operation.
    06126 ** ^The source database is read-locked only while it is being read;
    06127 ** it is not locked continuously for the entire backup operation.
    06128 ** ^Thus, the backup may be performed on a live source database without
    06129 ** preventing other database connections from
    06130 ** reading or writing to the source database while the backup is underway.
    06131 **
    06132 ** ^(To perform a backup operation:
    06133 **   <ol>
    06134 **     <li><b>sqlite3_backup_init()</b> is called once to initialize the
    06135 **         backup,
    06136 **     <li><b>sqlite3_backup_step()</b> is called one or more times to transfer
    06137 **         the data between the two databases, and finally
    06138 **     <li><b>sqlite3_backup_finish()</b> is called to release all resources
    06139 **         associated with the backup operation.
    06140 **   </ol>)^
    06141 ** There should be exactly one call to sqlite3_backup_finish() for each
    06142 ** successful call to sqlite3_backup_init().
    06143 **
    06144 ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b>
    06145 **
    06146 ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the
    06147 ** [database connection] associated with the destination database
    06148 ** and the database name, respectively.
    06149 ** ^The database name is "main" for the main database, "temp" for the
    06150 ** temporary database, or the name specified after the AS keyword in
    06151 ** an [ATTACH] statement for an attached database.
    06152 ** ^The S and M arguments passed to
    06153 ** sqlite3_backup_init(D,N,S,M) identify the [database connection]
    06154 ** and database name of the source database, respectively.
    06155 ** ^The source and destination [database connections] (parameters S and D)
    06156 ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
    06157 ** an error.
    06158 **
    06159 ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
    06160 ** returned and an error code and error message are stored in the
    06161 ** destination [database connection] D.
    06162 ** ^The error code and message for the failed call to sqlite3_backup_init()
    06163 ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
    06164 ** [sqlite3_errmsg16()] functions.
    06165 ** ^A successful call to sqlite3_backup_init() returns a pointer to an
    06166 ** [sqlite3_backup] object.
    06167 ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and
    06168 ** sqlite3_backup_finish() functions to perform the specified backup
    06169 ** operation.
    06170 **
    06171 ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b>
    06172 **
    06173 ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between
    06174 ** the source and destination databases specified by [sqlite3_backup] object B.
    06175 ** ^If N is negative, all remaining source pages are copied.
    06176 ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there
    06177 ** are still more pages to be copied, then the function returns [SQLITE_OK].
    06178 ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages
    06179 ** from source to destination, then it returns [SQLITE_DONE].
    06180 ** ^If an error occurs while running sqlite3_backup_step(B,N),
    06181 ** then an [error code] is returned. ^As well as [SQLITE_OK] and
    06182 ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
    06183 ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an
    06184 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
    06185 **
    06186 ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if
    06187 ** <ol>
    06188 ** <li> the destination database was opened read-only, or
    06189 ** <li> the destination database is using write-ahead-log journaling
    06190 ** and the destination and source page sizes differ, or
    06191 ** <li> the destination database is an in-memory database and the
    06192 ** destination and source page sizes differ.
    06193 ** </ol>)^
    06194 **
    06195 ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then
    06196 ** the [sqlite3_busy_handler | busy-handler function]
    06197 ** is invoked (if one is specified). ^If the
    06198 ** busy-handler returns non-zero before the lock is available, then
    06199 ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to
    06200 ** sqlite3_backup_step() can be retried later. ^If the source
    06201 ** [database connection]
    06202 ** is being used to write to the source database when sqlite3_backup_step()
    06203 ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this
    06204 ** case the call to sqlite3_backup_step() can be retried later on. ^(If
    06205 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or
    06206 ** [SQLITE_READONLY] is returned, then
    06207 ** there is no point in retrying the call to sqlite3_backup_step(). These
    06208 ** errors are considered fatal.)^  The application must accept
    06209 ** that the backup operation has failed and pass the backup operation handle
    06210 ** to the sqlite3_backup_finish() to release associated resources.
    06211 **
    06212 ** ^The first call to sqlite3_backup_step() obtains an exclusive lock
    06213 ** on the destination file. ^The exclusive lock is not released until either
    06214 ** sqlite3_backup_finish() is called or the backup operation is complete
    06215 ** and sqlite3_backup_step() returns [SQLITE_DONE].  ^Every call to
    06216 ** sqlite3_backup_step() obtains a [shared lock] on the source database that
    06217 ** lasts for the duration of the sqlite3_backup_step() call.
    06218 ** ^Because the source database is not locked between calls to
    06219 ** sqlite3_backup_step(), the source database may be modified mid-way
    06220 ** through the backup process.  ^If the source database is modified by an
    06221 ** external process or via a database connection other than the one being
    06222 ** used by the backup operation, then the backup will be automatically
    06223 ** restarted by the next call to sqlite3_backup_step(). ^If the source
    06224 ** database is modified by the using the same database connection as is used
    06225 ** by the backup operation, then the backup database is automatically
    06226 ** updated at the same time.
    06227 **
    06228 ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b>
    06229 **
    06230 ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the
    06231 ** application wishes to abandon the backup operation, the application
    06232 ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish().
    06233 ** ^The sqlite3_backup_finish() interfaces releases all
    06234 ** resources associated with the [sqlite3_backup] object.
    06235 ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any
    06236 ** active write-transaction on the destination database is rolled back.
    06237 ** The [sqlite3_backup] object is invalid
    06238 ** and may not be used following a call to sqlite3_backup_finish().
    06239 **
    06240 ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no
    06241 ** sqlite3_backup_step() errors occurred, regardless or whether or not
    06242 ** sqlite3_backup_step() completed.
    06243 ** ^If an out-of-memory condition or IO error occurred during any prior
    06244 ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then
    06245 ** sqlite3_backup_finish() returns the corresponding [error code].
    06246 **
    06247 ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step()
    06248 ** is not a permanent error and does not affect the return value of
    06249 ** sqlite3_backup_finish().
    06250 **
    06251 ** [[sqlite3_backup__remaining()]] [[sqlite3_backup_pagecount()]]
    06252 ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b>
    06253 **
    06254 ** ^Each call to sqlite3_backup_step() sets two values inside
    06255 ** the [sqlite3_backup] object: the number of pages still to be backed
    06256 ** up and the total number of pages in the source database file.
    06257 ** The sqlite3_backup_remaining() and sqlite3_backup_pagecount() interfaces
    06258 ** retrieve these two values, respectively.
    06259 **
    06260 ** ^The values returned by these functions are only updated by
    06261 ** sqlite3_backup_step(). ^If the source database is modified during a backup
    06262 ** operation, then the values are not updated to account for any extra
    06263 ** pages that need to be updated or the size of the source database file
    06264 ** changing.
    06265 **
    06266 ** <b>Concurrent Usage of Database Handles</b>
    06267 **
    06268 ** ^The source [database connection] may be used by the application for other
    06269 ** purposes while a backup operation is underway or being initialized.
    06270 ** ^If SQLite is compiled and configured to support threadsafe database
    06271 ** connections, then the source database connection may be used concurrently
    06272 ** from within other threads.
    06273 **
    06274 ** However, the application must guarantee that the destination
    06275 ** [database connection] is not passed to any other API (by any thread) after
    06276 ** sqlite3_backup_init() is called and before the corresponding call to
    06277 ** sqlite3_backup_finish().  SQLite does not currently check to see
    06278 ** if the application incorrectly accesses the destination [database connection]
    06279 ** and so no error code is reported, but the operations may malfunction
    06280 ** nevertheless.  Use of the destination database connection while a
    06281 ** backup is in progress might also also cause a mutex deadlock.
    06282 **
    06283 ** If running in [shared cache mode], the application must
    06284 ** guarantee that the shared cache used by the destination database
    06285 ** is not accessed while the backup is running. In practice this means
    06286 ** that the application must guarantee that the disk file being
    06287 ** backed up to is not accessed by any connection within the process,
    06288 ** not just the specific connection that was passed to sqlite3_backup_init().
    06289 **
    06290 ** The [sqlite3_backup] object itself is partially threadsafe. Multiple
    06291 ** threads may safely make multiple concurrent calls to sqlite3_backup_step().
    06292 ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()
    06293 ** APIs are not strictly speaking threadsafe. If they are invoked at the
    06294 ** same time as another thread is invoking sqlite3_backup_step() it is
    06295 ** possible that they return invalid values.
    06296 */
    06297 SQLITE_API sqlite3_backup *sqlite3_backup_init(
    06298   sqlite3 *pDest,                        /* Destination database handle */
    06299   const char *zDestName,                 /* Destination database name */
    06300   sqlite3 *pSource,                      /* Source database handle */
    06301   const char *zSourceName                /* Source database name */
    06302 );
    06303 SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage);
    06304 SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p);
    06305 SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p);
    06306 SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p);
    06307
    06308 /*
    06309 ** CAPI3REF: Unlock Notification
    06310 **
    06311 ** ^When running in shared-cache mode, a database operation may fail with
    06312 ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
    06313 ** individual tables within the shared-cache cannot be obtained. See
    06314 ** [SQLite Shared-Cache Mode] for a description of shared-cache locking.
    06315 ** ^This API may be used to register a callback that SQLite will invoke
    06316 ** when the connection currently holding the required lock relinquishes it.
    06317 ** ^This API is only available if the library was compiled with the
    06318 ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.
    06319 **
    06320 ** See Also: [Using the SQLite Unlock Notification Feature].
    06321 **
    06322 ** ^Shared-cache locks are released when a database connection concludes
    06323 ** its current transaction, either by committing it or rolling it back.
    06324 **
    06325 ** ^When a connection (known as the blocked connection) fails to obtain a
    06326 ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the
    06327 ** identity of the database connection (the blocking connection) that
    06328 ** has locked the required resource is stored internally. ^After an
    06329 ** application receives an SQLITE_LOCKED error, it may call the
    06330 ** sqlite3_unlock_notify() method with the blocked connection handle as
    06331 ** the first argument to register for a callback that will be invoked
    06332 ** when the blocking connections current transaction is concluded. ^The
    06333 ** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
    06334 ** call that concludes the blocking connections transaction.
    06335 **
    06336 ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application,
    06337 ** there is a chance that the blocking connection will have already
    06338 ** concluded its transaction by the time sqlite3_unlock_notify() is invoked.
    06339 ** If this happens, then the specified callback is invoked immediately,
    06340 ** from within the call to sqlite3_unlock_notify().)^
    06341 **
    06342 ** ^If the blocked connection is attempting to obtain a write-lock on a
    06343 ** shared-cache table, and more than one other connection currently holds
    06344 ** a read-lock on the same table, then SQLite arbitrarily selects one of
    06345 ** the other connections to use as the blocking connection.
    06346 **
    06347 ** ^(There may be at most one unlock-notify callback registered by a
    06348 ** blocked connection. If sqlite3_unlock_notify() is called when the
    06349 ** blocked connection already has a registered unlock-notify callback,
    06350 ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is
    06351 ** called with a NULL pointer as its second argument, then any existing
    06352 ** unlock-notify callback is canceled. ^The blocked connections
    06353 ** unlock-notify callback may also be canceled by closing the blocked
    06354 ** connection using [sqlite3_close()].
    06355 **
    06356 ** The unlock-notify callback is not reentrant. If an application invokes
    06357 ** any sqlite3_xxx API functions from within an unlock-notify callback, a
    06358 ** crash or deadlock may be the result.
    06359 **
    06360 ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always
    06361 ** returns SQLITE_OK.
    06362 **
    06363 ** <b>Callback Invocation Details</b>
    06364 **
    06365 ** When an unlock-notify callback is registered, the application provides a
    06366 ** single void* pointer that is passed to the callback when it is invoked.
    06367 ** However, the signature of the callback function allows SQLite to pass
    06368 ** it an array of void* context pointers. The first argument passed to
    06369 ** an unlock-notify callback is a pointer to an array of void* pointers,
    06370 ** and the second is the number of entries in the array.
    06371 **
    06372 ** When a blocking connections transaction is concluded, there may be
    06373 ** more than one blocked connection that has registered for an unlock-notify
    06374 ** callback. ^If two or more such blocked connections have specified the
    06375 ** same callback function, then instead of invoking the callback function
    06376 ** multiple times, it is invoked once with the set of void* context pointers
    06377 ** specified by the blocked connections bundled together into an array.
    06378 ** This gives the application an opportunity to prioritize any actions
    06379 ** related to the set of unblocked database connections.
    06380 **
    06381 ** <b>Deadlock Detection</b>
    06382 **
    06383 ** Assuming that after registering for an unlock-notify callback a
    06384 ** database waits for the callback to be issued before taking any further
    06385 ** action (a reasonable assumption), then using this API may cause the
    06386 ** application to deadlock. For example, if connection X is waiting for
    06387 ** connection Y's transaction to be concluded, and similarly connection
    06388 ** Y is waiting on connection X's transaction, then neither connection
    06389 ** will proceed and the system may remain deadlocked indefinitely.
    06390 **
    06391 ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock
    06392 ** detection. ^If a given call to sqlite3_unlock_notify() would put the
    06393 ** system in a deadlocked state, then SQLITE_LOCKED is returned and no
    06394 ** unlock-notify callback is registered. The system is said to be in
    06395 ** a deadlocked state if connection A has registered for an unlock-notify
    06396 ** callback on the conclusion of connection B's transaction, and connection
    06397 ** B has itself registered for an unlock-notify callback when connection
    06398 ** A's transaction is concluded. ^Indirect deadlock is also detected, so
    06399 ** the system is also considered to be deadlocked if connection B has
    06400 ** registered for an unlock-notify callback on the conclusion of connection
    06401 ** C's transaction, where connection C is waiting on connection A. ^Any
    06402 ** number of levels of indirection are allowed.
    06403 **
    06404 ** <b>The "DROP TABLE" Exception</b>
    06405 **
    06406 ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost
    06407 ** always appropriate to call sqlite3_unlock_notify(). There is however,
    06408 ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,
    06409 ** SQLite checks if there are any currently executing SELECT statements
    06410 ** that belong to the same connection. If there are, SQLITE_LOCKED is
    06411 ** returned. In this case there is no "blocking connection", so invoking
    06412 ** sqlite3_unlock_notify() results in the unlock-notify callback being
    06413 ** invoked immediately. If the application then re-attempts the "DROP TABLE"
    06414 ** or "DROP INDEX" query, an infinite loop might be the result.
    06415 **
    06416 ** One way around this problem is to check the extended error code returned
    06417 ** by an sqlite3_step() call. ^(If there is a blocking connection, then the
    06418 ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in
    06419 ** the special "DROP TABLE/INDEX" case, the extended error code is just
    06420 ** SQLITE_LOCKED.)^
    06421 */
    06422 SQLITE_API int sqlite3_unlock_notify(
    06423   sqlite3 *pBlocked,                          /* Waiting connection */
    06424   void (*xNotify)(void **apArg, int nArg),    /* Callback function to invoke */
    06425   void *pNotifyArg                            /* Argument to pass to xNotify */
    06426 );
    06427
    06428
    06429 /*
    06430 ** CAPI3REF: String Comparison
    06431 **
    06432 ** ^The [sqlite3_strnicmp()] API allows applications and extensions to
    06433 ** compare the contents of two buffers containing UTF-8 strings in a
    06434 ** case-independent fashion, using the same definition of case independence
    06435 ** that SQLite uses internally when comparing identifiers.
    06436 */
    06437 SQLITE_API int sqlite3_strnicmp(const char *, const char *, int);
    06438
    06439 /*
    06440 ** CAPI3REF: Error Logging Interface
    06441 **
    06442 ** ^The [sqlite3_log()] interface writes a message into the error log
    06443 ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
    06444 ** ^If logging is enabled, the zFormat string and subsequent arguments are
    06445 ** used with [sqlite3_snprintf()] to generate the final output string.
    06446 **
    06447 ** The sqlite3_log() interface is intended for use by extensions such as
    06448 ** virtual tables, collating functions, and SQL functions.  While there is
    06449 ** nothing to prevent an application from calling sqlite3_log(), doing so
    06450 ** is considered bad form.
    06451 **
    06452 ** The zFormat string must not be NULL.
    06453 **
    06454 ** To avoid deadlocks and other threading problems, the sqlite3_log() routine
    06455 ** will not use dynamically allocated memory.  The log message is stored in
    06456 ** a fixed-length buffer on the stack.  If the log message is longer than
    06457 ** a few hundred characters, it will be truncated to the length of the
    06458 ** buffer.
    06459 */
    06460 SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...);
    06461
    06462 /*
    06463 ** CAPI3REF: Write-Ahead Log Commit Hook
    06464 **
    06465 ** ^The [sqlite3_wal_hook()] function is used to register a callback that
    06466 ** will be invoked each time a database connection commits data to a
    06467 ** [write-ahead log] (i.e. whenever a transaction is committed in
    06468 ** [journal_mode | journal_mode=WAL mode]).
    06469 **
    06470 ** ^The callback is invoked by SQLite after the commit has taken place and
    06471 ** the associated write-lock on the database released, so the implementation
    06472 ** may read, write or [checkpoint] the database as required.
    06473 **
    06474 ** ^The first parameter passed to the callback function when it is invoked
    06475 ** is a copy of the third parameter passed to sqlite3_wal_hook() when
    06476 ** registering the callback. ^The second is a copy of the database handle.
    06477 ** ^The third parameter is the name of the database that was written to -
    06478 ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter
    06479 ** is the number of pages currently in the write-ahead log file,
    06480 ** including those that were just committed.
    06481 **
    06482 ** The callback function should normally return [SQLITE_OK].  ^If an error
    06483 ** code is returned, that error will propagate back up through the
    06484 ** SQLite code base to cause the statement that provoked the callback
    06485 ** to report an error, though the commit will have still occurred. If the
    06486 ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value
    06487 ** that does not correspond to any valid SQLite error code, the results
    06488 ** are undefined.
    06489 **
    06490 ** A single database handle may have at most a single write-ahead log callback
    06491 ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any
    06492 ** previously registered write-ahead log callback. ^Note that the
    06493 ** [sqlite3_wal_autocheckpoint()] interface and the
    06494 ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will
    06495 ** those overwrite any prior [sqlite3_wal_hook()] settings.
    06496 */
    06497 SQLITE_API void *sqlite3_wal_hook(
    06498   sqlite3*,
    06499   int(*)(void *,sqlite3*,const char*,int),
    06500   void*
    06501 );
    06502
    06503 /*
    06504 ** CAPI3REF: Configure an auto-checkpoint
    06505 **
    06506 ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around
    06507 ** [sqlite3_wal_hook()] that causes any database on [database connection] D
    06508 ** to automatically [checkpoint]
    06509 ** after committing a transaction if there are N or
    06510 ** more frames in the [write-ahead log] file.  ^Passing zero or
    06511 ** a negative value as the nFrame parameter disables automatic
    06512 ** checkpoints entirely.
    06513 **
    06514 ** ^The callback registered by this function replaces any existing callback
    06515 ** registered using [sqlite3_wal_hook()].  ^Likewise, registering a callback
    06516 ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism
    06517 ** configured by this function.
    06518 **
    06519 ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface
    06520 ** from SQL.
    06521 **
    06522 ** ^Every new [database connection] defaults to having the auto-checkpoint
    06523 ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT]
    06524 ** pages.  The use of this interface
    06525 ** is only necessary if the default setting is found to be suboptimal
    06526 ** for a particular application.
    06527 */
    06528 SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N);
    06529
    06530 /*
    06531 ** CAPI3REF: Checkpoint a database
    06532 **
    06533 ** ^The [sqlite3_wal_checkpoint(D,X)] interface causes database named X
    06534 ** on [database connection] D to be [checkpointed].  ^If X is NULL or an
    06535 ** empty string, then a checkpoint is run on all databases of
    06536 ** connection D.  ^If the database connection D is not in
    06537 ** [WAL | write-ahead log mode] then this interface is a harmless no-op.
    06538 **
    06539 ** ^The [wal_checkpoint pragma] can be used to invoke this interface
    06540 ** from SQL.  ^The [sqlite3_wal_autocheckpoint()] interface and the
    06541 ** [wal_autocheckpoint pragma] can be used to cause this interface to be
    06542 ** run whenever the WAL reaches a certain size threshold.
    06543 **
    06544 ** See also: [sqlite3_wal_checkpoint_v2()]
    06545 */
    06546 SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb);
    06547
    06548 /*
    06549 ** CAPI3REF: Checkpoint a database
    06550 **
    06551 ** Run a checkpoint operation on WAL database zDb attached to database
    06552 ** handle db. The specific operation is determined by the value of the
    06553 ** eMode parameter:
    06554 **
    06555 ** <dl>
    06556 ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd>
    06557 **   Checkpoint as many frames as possible without waiting for any database
    06558 **   readers or writers to finish. Sync the db file if all frames in the log
    06559 **   are checkpointed. This mode is the same as calling
    06560 **   sqlite3_wal_checkpoint(). The busy-handler callback is never invoked.
    06561 **
    06562 ** <dt>SQLITE_CHECKPOINT_FULL<dd>
    06563 **   This mode blocks (calls the busy-handler callback) until there is no
    06564 **   database writer and all readers are reading from the most recent database
    06565 **   snapshot. It then checkpoints all frames in the log file and syncs the
    06566 **   database file. This call blocks database writers while it is running,
    06567 **   but not database readers.
    06568 **
    06569 ** <dt>SQLITE_CHECKPOINT_RESTART<dd>
    06570 **   This mode works the same way as SQLITE_CHECKPOINT_FULL, except after
    06571 **   checkpointing the log file it blocks (calls the busy-handler callback)
    06572 **   until all readers are reading from the database file only. This ensures
    06573 **   that the next client to write to the database file restarts the log file
    06574 **   from the beginning. This call blocks database writers while it is running,
    06575 **   but not database readers.
    06576 ** </dl>
    06577 **
    06578 ** If pnLog is not NULL, then *pnLog is set to the total number of frames in
    06579 ** the log file before returning. If pnCkpt is not NULL, then *pnCkpt is set to
    06580 ** the total number of checkpointed frames (including any that were already
    06581 ** checkpointed when this function is called). *pnLog and *pnCkpt may be
    06582 ** populated even if sqlite3_wal_checkpoint_v2() returns other than SQLITE_OK.
    06583 ** If no values are available because of an error, they are both set to -1
    06584 ** before returning to communicate this to the caller.
    06585 **
    06586 ** All calls obtain an exclusive "checkpoint" lock on the database file. If
    06587 ** any other process is running a checkpoint operation at the same time, the
    06588 ** lock cannot be obtained and SQLITE_BUSY is returned. Even if there is a
    06589 ** busy-handler configured, it will not be invoked in this case.
    06590 **
    06591 ** The SQLITE_CHECKPOINT_FULL and RESTART modes also obtain the exclusive
    06592 ** "writer" lock on the database file. If the writer lock cannot be obtained
    06593 ** immediately, and a busy-handler is configured, it is invoked and the writer
    06594 ** lock retried until either the busy-handler returns 0 or the lock is
    06595 ** successfully obtained. The busy-handler is also invoked while waiting for
    06596 ** database readers as described above. If the busy-handler returns 0 before
    06597 ** the writer lock is obtained or while waiting for database readers, the
    06598 ** checkpoint operation proceeds from that point in the same way as
    06599 ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible
    06600 ** without blocking any further. SQLITE_BUSY is returned in this case.
    06601 **
    06602 ** If parameter zDb is NULL or points to a zero length string, then the
    06603 ** specified operation is attempted on all WAL databases. In this case the
    06604 ** values written to output parameters *pnLog and *pnCkpt are undefined. If
    06605 ** an SQLITE_BUSY error is encountered when processing one or more of the
    06606 ** attached WAL databases, the operation is still attempted on any remaining
    06607 ** attached databases and SQLITE_BUSY is returned to the caller. If any other
    06608 ** error occurs while processing an attached database, processing is abandoned
    06609 ** and the error code returned to the caller immediately. If no error
    06610 ** (SQLITE_BUSY or otherwise) is encountered while processing the attached
    06611 ** databases, SQLITE_OK is returned.
    06612 **
    06613 ** If database zDb is the name of an attached database that is not in WAL
    06614 ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. If
    06615 ** zDb is not NULL (or a zero length string) and is not the name of any
    06616 ** attached database, SQLITE_ERROR is returned to the caller.
    06617 */
    06618 SQLITE_API int sqlite3_wal_checkpoint_v2(
    06619   sqlite3 *db,                    /* Database handle */
    06620   const char *zDb,                /* Name of attached database (or NULL) */
    06621   int eMode,                      /* SQLITE_CHECKPOINT_* value */
    06622   int *pnLog,                     /* OUT: Size of WAL log in frames */
    06623   int *pnCkpt                     /* OUT: Total number of frames checkpointed */
    06624 );
    06625
    06626 /*
    06627 ** CAPI3REF: Checkpoint operation parameters
    06628 **
    06629 ** These constants can be used as the 3rd parameter to
    06630 ** [sqlite3_wal_checkpoint_v2()].  See the [sqlite3_wal_checkpoint_v2()]
    06631 ** documentation for additional information about the meaning and use of
    06632 ** each of these values.
    06633 */
    06634 #define SQLITE_CHECKPOINT_PASSIVE 0
    06635 #define SQLITE_CHECKPOINT_FULL    1
    06636 #define SQLITE_CHECKPOINT_RESTART 2
    06637
    06638 /*
    06639 ** CAPI3REF: Virtual Table Interface Configuration
    06640 **
    06641 ** This function may be called by either the [xConnect] or [xCreate] method
    06642 ** of a [virtual table] implementation to configure
    06643 ** various facets of the virtual table interface.
    06644 **
    06645 ** If this interface is invoked outside the context of an xConnect or
    06646 ** xCreate virtual table method then the behavior is undefined.
    06647 **
    06648 ** At present, there is only one option that may be configured using
    06649 ** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].)  Further options
    06650 ** may be added in the future.
    06651 */
    06652 SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...);
    06653
    06654 /*
    06655 ** CAPI3REF: Virtual Table Configuration Options
    06656 **
    06657 ** These macros define the various options to the
    06658 ** [sqlite3_vtab_config()] interface that [virtual table] implementations
    06659 ** can use to customize and optimize their behavior.
    06660 **
    06661 ** <dl>
    06662 ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT
    06663 ** <dd>Calls of the form
    06664 ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported,
    06665 ** where X is an integer.  If X is zero, then the [virtual table] whose
    06666 ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not
    06667 ** support constraints.  In this configuration (which is the default) if
    06668 ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire
    06669 ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been
    06670 ** specified as part of the users SQL statement, regardless of the actual
    06671 ** ON CONFLICT mode specified.
    06672 **
    06673 ** If X is non-zero, then the virtual table implementation guarantees
    06674 ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before
    06675 ** any modifications to internal or persistent data structures have been made.
    06676 ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite
    06677 ** is able to roll back a statement or database transaction, and abandon
    06678 ** or continue processing the current SQL statement as appropriate.
    06679 ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns
    06680 ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode
    06681 ** had been ABORT.
    06682 **
    06683 ** Virtual table implementations that are required to handle OR REPLACE
    06684 ** must do so within the [xUpdate] method. If a call to the
    06685 ** [sqlite3_vtab_on_conflict()] function indicates that the current ON
    06686 ** CONFLICT policy is REPLACE, the virtual table implementation should
    06687 ** silently replace the appropriate rows within the xUpdate callback and
    06688 ** return SQLITE_OK. Or, if this is not possible, it may return
    06689 ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT
    06690 ** constraint handling.
    06691 ** </dl>
    06692 */
    06693 #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1
    06694
    06695 /*
    06696 ** CAPI3REF: Determine The Virtual Table Conflict Policy
    06697 **
    06698 ** This function may only be called from within a call to the [xUpdate] method
    06699 ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The
    06700 ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL],
    06701 ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode
    06702 ** of the SQL statement that triggered the call to the [xUpdate] method of the
    06703 ** [virtual table].
    06704 */
    06705 SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *);
    06706
    06707 /*
    06708 ** CAPI3REF: Conflict resolution modes
    06709 **
    06710 ** These constants are returned by [sqlite3_vtab_on_conflict()] to
    06711 ** inform a [virtual table] implementation what the [ON CONFLICT] mode
    06712 ** is for the SQL statement being evaluated.
    06713 **
    06714 ** Note that the [SQLITE_IGNORE] constant is also used as a potential
    06715 ** return value from the [sqlite3_set_authorizer()] callback and that
    06716 ** [SQLITE_ABORT] is also a [result code].
    06717 */
    06718 #define SQLITE_ROLLBACK 1
    06719 /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */
    06720 #define SQLITE_FAIL     3
    06721 /* #define SQLITE_ABORT 4  // Also an error code */
    06722 #define SQLITE_REPLACE  5
    06723
    06724
    06725
    06726 /*
    06727 ** Undo the hack that converts floating point types to integer for
    06728 ** builds on processors without floating point support.
    06729 */
    06730 #ifdef SQLITE_OMIT_FLOATING_POINT
    06731 # undef double
    06732 #endif
    06733
    06734 #ifdef __cplusplus
    06735 }  /* End of the 'extern "C"' block */
    06736 #endif
    06737 #endif
    06738
    06739 /*
    06740 ** 2010 August 30
    06741 **
    06742 ** The author disclaims copyright to this source code.  In place of
    06743 ** a legal notice, here is a blessing:
    06744 **
    06745 **    May you do good and not evil.
    06746 **    May you find forgiveness for yourself and forgive others.
    06747 **    May you share freely, never taking more than you give.
    06748 **
    06749 *************************************************************************
    06750 */
    06751
    06752 #ifndef _SQLITE3RTREE_H_
    06753 #define _SQLITE3RTREE_H_
    06754
    06755
    06756 #ifdef __cplusplus
    06757 extern "C" {
    06758 #endif
    06759
    06760 typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;
    06761
    06762 /*
    06763 ** Register a geometry callback named zGeom that can be used as part of an
    06764 ** R-Tree geometry query as follows:
    06765 **
    06766 **   SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...)
    06767 */
    06768 SQLITE_API int sqlite3_rtree_geometry_callback(
    06769   sqlite3 *db,
    06770   const char *zGeom,
    06771   int (*xGeom)(sqlite3_rtree_geometry *, int nCoord, double *aCoord, int *pRes),
    06772   void *pContext
    06773 );
    06774
    06775
    06776 /*
    06777 ** A pointer to a structure of the following type is passed as the first
    06778 ** argument to callbacks registered using rtree_geometry_callback().
    06779 */
    06780 struct sqlite3_rtree_geometry {
    06781   void *pContext;                 /* Copy of pContext passed to s_r_g_c() */
    06782   int nParam;                     /* Size of array aParam[] */
    06783   double *aParam;                 /* Parameters passed to SQL geom function */
    06784   void *pUser;                    /* Callback implementation user data */
    06785   void (*xDelUser)(void *);       /* Called by SQLite to clean up pUser */
    06786 };
    06787
    06788
    06789 #ifdef __cplusplus
    06790 }  /* end of the 'extern "C"' block */
    06791 #endif
    06792
    06793 #endif  /* ifndef _SQLITE3RTREE_H_ */
    06794

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