sqlite3.h
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1 /*
2 ** 2001 September 15
3 **
4 ** The author disclaims copyright to this source code. In place of
5 ** a legal notice, here is a blessing:
6 **
7 ** May you do good and not evil.
8 ** May you find forgiveness for yourself and forgive others.
9 ** May you share freely, never taking more than you give.
10 **
11 *************************************************************************
12 ** This header file defines the interface that the SQLite library
13 ** presents to client programs. If a C-function, structure, datatype,
14 ** or constant definition does not appear in this file, then it is
15 ** not a published API of SQLite, is subject to change without
16 ** notice, and should not be referenced by programs that use SQLite.
17 **
18 ** Some of the definitions that are in this file are marked as
19 ** "experimental". Experimental interfaces are normally new
20 ** features recently added to SQLite. We do not anticipate changes
21 ** to experimental interfaces but reserve the right to make minor changes
22 ** if experience from use "in the wild" suggest such changes are prudent.
23 **
24 ** The official C-language API documentation for SQLite is derived
25 ** from comments in this file. This file is the authoritative source
26 ** on how SQLite interfaces are suppose to operate.
27 **
28 ** The name of this file under configuration management is "sqlite.h.in".
29 ** The makefile makes some minor changes to this file (such as inserting
30 ** the version number) and changes its name to "sqlite3.h" as
31 ** part of the build process.
32 */
33 #ifndef _SQLITE3_H_
34 #define _SQLITE3_H_
35 #include <stdarg.h> /* Needed for the definition of va_list */
36 
37 /*
38 ** Make sure we can call this stuff from C++.
39 */
40 #ifdef __cplusplus
41 extern "C" {
42 #endif
43 
44 
45 /*
46 ** Add the ability to override 'extern'
47 */
48 #ifndef SQLITE_EXTERN
49 # define SQLITE_EXTERN extern
50 #endif
51 
52 #ifndef SQLITE_API
53 # define SQLITE_API
54 #endif
55 
56 
57 /*
58 ** These no-op macros are used in front of interfaces to mark those
59 ** interfaces as either deprecated or experimental. New applications
60 ** should not use deprecated interfaces - they are support for backwards
61 ** compatibility only. Application writers should be aware that
62 ** experimental interfaces are subject to change in point releases.
63 **
64 ** These macros used to resolve to various kinds of compiler magic that
65 ** would generate warning messages when they were used. But that
66 ** compiler magic ended up generating such a flurry of bug reports
67 ** that we have taken it all out and gone back to using simple
68 ** noop macros.
69 */
70 #define SQLITE_DEPRECATED
71 #define SQLITE_EXPERIMENTAL
72 
73 /*
74 ** Ensure these symbols were not defined by some previous header file.
75 */
76 #ifdef SQLITE_VERSION
77 # undef SQLITE_VERSION
78 #endif
79 #ifdef SQLITE_VERSION_NUMBER
80 # undef SQLITE_VERSION_NUMBER
81 #endif
82 
83 /*
84 ** CAPI3REF: Compile-Time Library Version Numbers
85 **
86 ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header
87 ** evaluates to a string literal that is the SQLite version in the
88 ** format "X.Y.Z" where X is the major version number (always 3 for
89 ** SQLite3) and Y is the minor version number and Z is the release number.)^
90 ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer
91 ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same
92 ** numbers used in [SQLITE_VERSION].)^
93 ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also
94 ** be larger than the release from which it is derived. Either Y will
95 ** be held constant and Z will be incremented or else Y will be incremented
96 ** and Z will be reset to zero.
97 **
98 ** Since version 3.6.18, SQLite source code has been stored in the
99 ** <a href="http://www.fossil-scm.org/">Fossil configuration management
100 ** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to
101 ** a string which identifies a particular check-in of SQLite
102 ** within its configuration management system. ^The SQLITE_SOURCE_ID
103 ** string contains the date and time of the check-in (UTC) and an SHA1
104 ** hash of the entire source tree.
105 **
106 ** See also: [sqlite3_libversion()],
107 ** [sqlite3_libversion_number()], [sqlite3_sourceid()],
108 ** [sqlite_version()] and [sqlite_source_id()].
109 */
110 #define SQLITE_VERSION "3.8.2"
111 #define SQLITE_VERSION_NUMBER 3008002
112 #define SQLITE_SOURCE_ID "2013-12-06 14:53:30 27392118af4c38c5203a04b8013e1afdb1cebd0d"
113 
114 /*
115 ** CAPI3REF: Run-Time Library Version Numbers
116 ** KEYWORDS: sqlite3_version, sqlite3_sourceid
117 **
118 ** These interfaces provide the same information as the [SQLITE_VERSION],
119 ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
120 ** but are associated with the library instead of the header file. ^(Cautious
121 ** programmers might include assert() statements in their application to
122 ** verify that values returned by these interfaces match the macros in
123 ** the header, and thus insure that the application is
124 ** compiled with matching library and header files.
125 **
126 ** <blockquote><pre>
127 ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
128 ** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 );
129 ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
130 ** </pre></blockquote>)^
131 **
132 ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION]
133 ** macro. ^The sqlite3_libversion() function returns a pointer to the
134 ** to the sqlite3_version[] string constant. The sqlite3_libversion()
135 ** function is provided for use in DLLs since DLL users usually do not have
136 ** direct access to string constants within the DLL. ^The
137 ** sqlite3_libversion_number() function returns an integer equal to
138 ** [SQLITE_VERSION_NUMBER]. ^The sqlite3_sourceid() function returns
139 ** a pointer to a string constant whose value is the same as the
140 ** [SQLITE_SOURCE_ID] C preprocessor macro.
141 **
142 ** See also: [sqlite_version()] and [sqlite_source_id()].
143 */
145 SQLITE_API const char *sqlite3_libversion(void);
146 SQLITE_API const char *sqlite3_sourceid(void);
148 
149 /*
150 ** CAPI3REF: Run-Time Library Compilation Options Diagnostics
151 **
152 ** ^The sqlite3_compileoption_used() function returns 0 or 1
153 ** indicating whether the specified option was defined at
154 ** compile time. ^The SQLITE_ prefix may be omitted from the
155 ** option name passed to sqlite3_compileoption_used().
156 **
157 ** ^The sqlite3_compileoption_get() function allows iterating
158 ** over the list of options that were defined at compile time by
159 ** returning the N-th compile time option string. ^If N is out of range,
160 ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_
161 ** prefix is omitted from any strings returned by
162 ** sqlite3_compileoption_get().
163 **
164 ** ^Support for the diagnostic functions sqlite3_compileoption_used()
165 ** and sqlite3_compileoption_get() may be omitted by specifying the
166 ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time.
167 **
168 ** See also: SQL functions [sqlite_compileoption_used()] and
169 ** [sqlite_compileoption_get()] and the [compile_options pragma].
170 */
171 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
172 SQLITE_API int sqlite3_compileoption_used(const char *zOptName);
173 SQLITE_API const char *sqlite3_compileoption_get(int N);
174 #endif
175 
176 /*
177 ** CAPI3REF: Test To See If The Library Is Threadsafe
178 **
179 ** ^The sqlite3_threadsafe() function returns zero if and only if
180 ** SQLite was compiled with mutexing code omitted due to the
181 ** [SQLITE_THREADSAFE] compile-time option being set to 0.
182 **
183 ** SQLite can be compiled with or without mutexes. When
184 ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes
185 ** are enabled and SQLite is threadsafe. When the
186 ** [SQLITE_THREADSAFE] macro is 0,
187 ** the mutexes are omitted. Without the mutexes, it is not safe
188 ** to use SQLite concurrently from more than one thread.
189 **
190 ** Enabling mutexes incurs a measurable performance penalty.
191 ** So if speed is of utmost importance, it makes sense to disable
192 ** the mutexes. But for maximum safety, mutexes should be enabled.
193 ** ^The default behavior is for mutexes to be enabled.
194 **
195 ** This interface can be used by an application to make sure that the
196 ** version of SQLite that it is linking against was compiled with
197 ** the desired setting of the [SQLITE_THREADSAFE] macro.
198 **
199 ** This interface only reports on the compile-time mutex setting
200 ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with
201 ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but
202 ** can be fully or partially disabled using a call to [sqlite3_config()]
203 ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],
204 ** or [SQLITE_CONFIG_MUTEX]. ^(The return value of the
205 ** sqlite3_threadsafe() function shows only the compile-time setting of
206 ** thread safety, not any run-time changes to that setting made by
207 ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()
208 ** is unchanged by calls to sqlite3_config().)^
209 **
210 ** See the [threading mode] documentation for additional information.
211 */
213 
214 /*
215 ** CAPI3REF: Database Connection Handle
216 ** KEYWORDS: {database connection} {database connections}
217 **
218 ** Each open SQLite database is represented by a pointer to an instance of
219 ** the opaque structure named "sqlite3". It is useful to think of an sqlite3
220 ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and
221 ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
222 ** and [sqlite3_close_v2()] are its destructors. There are many other
223 ** interfaces (such as
224 ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
225 ** [sqlite3_busy_timeout()] to name but three) that are methods on an
226 ** sqlite3 object.
227 */
228 typedef struct sqlite3 sqlite3;
229 
230 /*
231 ** CAPI3REF: 64-Bit Integer Types
232 ** KEYWORDS: sqlite_int64 sqlite_uint64
233 **
234 ** Because there is no cross-platform way to specify 64-bit integer types
235 ** SQLite includes typedefs for 64-bit signed and unsigned integers.
236 **
237 ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
238 ** The sqlite_int64 and sqlite_uint64 types are supported for backwards
239 ** compatibility only.
240 **
241 ** ^The sqlite3_int64 and sqlite_int64 types can store integer values
242 ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The
243 ** sqlite3_uint64 and sqlite_uint64 types can store integer values
244 ** between 0 and +18446744073709551615 inclusive.
245 */
246 #ifdef SQLITE_INT64_TYPE
247  typedef SQLITE_INT64_TYPE sqlite_int64;
248  typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
249 #elif defined(_MSC_VER) || defined(__BORLANDC__)
250  typedef __int64 sqlite_int64;
251  typedef unsigned __int64 sqlite_uint64;
252 #else
253  typedef long long int sqlite_int64;
254  typedef unsigned long long int sqlite_uint64;
255 #endif
256 typedef sqlite_int64 sqlite3_int64;
257 typedef sqlite_uint64 sqlite3_uint64;
258 
259 /*
260 ** If compiling for a processor that lacks floating point support,
261 ** substitute integer for floating-point.
262 */
263 #ifdef SQLITE_OMIT_FLOATING_POINT
264 # define double sqlite3_int64
265 #endif
266 
267 /*
268 ** CAPI3REF: Closing A Database Connection
269 **
270 ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors
271 ** for the [sqlite3] object.
272 ** ^Calls to sqlite3_close() and sqlite3_close_v2() return SQLITE_OK if
273 ** the [sqlite3] object is successfully destroyed and all associated
274 ** resources are deallocated.
275 **
276 ** ^If the database connection is associated with unfinalized prepared
277 ** statements or unfinished sqlite3_backup objects then sqlite3_close()
278 ** will leave the database connection open and return [SQLITE_BUSY].
279 ** ^If sqlite3_close_v2() is called with unfinalized prepared statements
280 ** and unfinished sqlite3_backups, then the database connection becomes
281 ** an unusable "zombie" which will automatically be deallocated when the
282 ** last prepared statement is finalized or the last sqlite3_backup is
283 ** finished. The sqlite3_close_v2() interface is intended for use with
284 ** host languages that are garbage collected, and where the order in which
285 ** destructors are called is arbitrary.
286 **
287 ** Applications should [sqlite3_finalize | finalize] all [prepared statements],
288 ** [sqlite3_blob_close | close] all [BLOB handles], and
289 ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated
290 ** with the [sqlite3] object prior to attempting to close the object. ^If
291 ** sqlite3_close_v2() is called on a [database connection] that still has
292 ** outstanding [prepared statements], [BLOB handles], and/or
293 ** [sqlite3_backup] objects then it returns SQLITE_OK but the deallocation
294 ** of resources is deferred until all [prepared statements], [BLOB handles],
295 ** and [sqlite3_backup] objects are also destroyed.
296 **
297 ** ^If an [sqlite3] object is destroyed while a transaction is open,
298 ** the transaction is automatically rolled back.
299 **
300 ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)]
301 ** must be either a NULL
302 ** pointer or an [sqlite3] object pointer obtained
303 ** from [sqlite3_open()], [sqlite3_open16()], or
304 ** [sqlite3_open_v2()], and not previously closed.
305 ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer
306 ** argument is a harmless no-op.
307 */
310 
311 /*
312 ** The type for a callback function.
313 ** This is legacy and deprecated. It is included for historical
314 ** compatibility and is not documented.
315 */
316 typedef int (*sqlite3_callback)(void*,int,char**, char**);
317 
318 /*
319 ** CAPI3REF: One-Step Query Execution Interface
320 **
321 ** The sqlite3_exec() interface is a convenience wrapper around
322 ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
323 ** that allows an application to run multiple statements of SQL
324 ** without having to use a lot of C code.
325 **
326 ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,
327 ** semicolon-separate SQL statements passed into its 2nd argument,
328 ** in the context of the [database connection] passed in as its 1st
329 ** argument. ^If the callback function of the 3rd argument to
330 ** sqlite3_exec() is not NULL, then it is invoked for each result row
331 ** coming out of the evaluated SQL statements. ^The 4th argument to
332 ** sqlite3_exec() is relayed through to the 1st argument of each
333 ** callback invocation. ^If the callback pointer to sqlite3_exec()
334 ** is NULL, then no callback is ever invoked and result rows are
335 ** ignored.
336 **
337 ** ^If an error occurs while evaluating the SQL statements passed into
338 ** sqlite3_exec(), then execution of the current statement stops and
339 ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec()
340 ** is not NULL then any error message is written into memory obtained
341 ** from [sqlite3_malloc()] and passed back through the 5th parameter.
342 ** To avoid memory leaks, the application should invoke [sqlite3_free()]
343 ** on error message strings returned through the 5th parameter of
344 ** of sqlite3_exec() after the error message string is no longer needed.
345 ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
346 ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
347 ** NULL before returning.
348 **
349 ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
350 ** routine returns SQLITE_ABORT without invoking the callback again and
351 ** without running any subsequent SQL statements.
352 **
353 ** ^The 2nd argument to the sqlite3_exec() callback function is the
354 ** number of columns in the result. ^The 3rd argument to the sqlite3_exec()
355 ** callback is an array of pointers to strings obtained as if from
356 ** [sqlite3_column_text()], one for each column. ^If an element of a
357 ** result row is NULL then the corresponding string pointer for the
358 ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the
359 ** sqlite3_exec() callback is an array of pointers to strings where each
360 ** entry represents the name of corresponding result column as obtained
361 ** from [sqlite3_column_name()].
362 **
363 ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer
364 ** to an empty string, or a pointer that contains only whitespace and/or
365 ** SQL comments, then no SQL statements are evaluated and the database
366 ** is not changed.
367 **
368 ** Restrictions:
369 **
370 ** <ul>
371 ** <li> The application must insure that the 1st parameter to sqlite3_exec()
372 ** is a valid and open [database connection].
373 ** <li> The application must not close the [database connection] specified by
374 ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
375 ** <li> The application must not modify the SQL statement text passed into
376 ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
377 ** </ul>
378 */
380  sqlite3*, /* An open database */
381  const char *sql, /* SQL to be evaluated */
382  int (*callback)(void*,int,char**,char**), /* Callback function */
383  void *, /* 1st argument to callback */
384  char **errmsg /* Error msg written here */
385 );
386 
387 /*
388 ** CAPI3REF: Result Codes
389 ** KEYWORDS: SQLITE_OK {error code} {error codes}
390 ** KEYWORDS: {result code} {result codes}
391 **
392 ** Many SQLite functions return an integer result code from the set shown
393 ** here in order to indicate success or failure.
394 **
395 ** New error codes may be added in future versions of SQLite.
396 **
397 ** See also: [SQLITE_IOERR_READ | extended result codes],
398 ** [sqlite3_vtab_on_conflict()] [SQLITE_ROLLBACK | result codes].
399 */
400 #define SQLITE_OK 0 /* Successful result */
401 /* beginning-of-error-codes */
402 #define SQLITE_ERROR 1 /* SQL error or missing database */
403 #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */
404 #define SQLITE_PERM 3 /* Access permission denied */
405 #define SQLITE_ABORT 4 /* Callback routine requested an abort */
406 #define SQLITE_BUSY 5 /* The database file is locked */
407 #define SQLITE_LOCKED 6 /* A table in the database is locked */
408 #define SQLITE_NOMEM 7 /* A malloc() failed */
409 #define SQLITE_READONLY 8 /* Attempt to write a readonly database */
410 #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/
411 #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */
412 #define SQLITE_CORRUPT 11 /* The database disk image is malformed */
413 #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */
414 #define SQLITE_FULL 13 /* Insertion failed because database is full */
415 #define SQLITE_CANTOPEN 14 /* Unable to open the database file */
416 #define SQLITE_PROTOCOL 15 /* Database lock protocol error */
417 #define SQLITE_EMPTY 16 /* Database is empty */
418 #define SQLITE_SCHEMA 17 /* The database schema changed */
419 #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */
420 #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */
421 #define SQLITE_MISMATCH 20 /* Data type mismatch */
422 #define SQLITE_MISUSE 21 /* Library used incorrectly */
423 #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */
424 #define SQLITE_AUTH 23 /* Authorization denied */
425 #define SQLITE_FORMAT 24 /* Auxiliary database format error */
426 #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */
427 #define SQLITE_NOTADB 26 /* File opened that is not a database file */
428 #define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */
429 #define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */
430 #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */
431 #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */
432 /* end-of-error-codes */
433 
434 /*
435 ** CAPI3REF: Extended Result Codes
436 ** KEYWORDS: {extended error code} {extended error codes}
437 ** KEYWORDS: {extended result code} {extended result codes}
438 **
439 ** In its default configuration, SQLite API routines return one of 26 integer
440 ** [SQLITE_OK | result codes]. However, experience has shown that many of
441 ** these result codes are too coarse-grained. They do not provide as
442 ** much information about problems as programmers might like. In an effort to
443 ** address this, newer versions of SQLite (version 3.3.8 and later) include
444 ** support for additional result codes that provide more detailed information
445 ** about errors. The extended result codes are enabled or disabled
446 ** on a per database connection basis using the
447 ** [sqlite3_extended_result_codes()] API.
448 **
449 ** Some of the available extended result codes are listed here.
450 ** One may expect the number of extended result codes will increase
451 ** over time. Software that uses extended result codes should expect
452 ** to see new result codes in future releases of SQLite.
453 **
454 ** The SQLITE_OK result code will never be extended. It will always
455 ** be exactly zero.
456 */
457 #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8))
458 #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8))
459 #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8))
460 #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8))
461 #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8))
462 #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8))
463 #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8))
464 #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8))
465 #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8))
466 #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8))
467 #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8))
468 #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8))
469 #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8))
470 #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8))
471 #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8))
472 #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8))
473 #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8))
474 #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8))
475 #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8))
476 #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8))
477 #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8))
478 #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8))
479 #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8))
480 #define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8))
481 #define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8))
482 #define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8))
483 #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8))
484 #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8))
485 #define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8))
486 #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8))
487 #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8))
488 #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8))
489 #define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8))
490 #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8))
491 #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8))
492 #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8))
493 #define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8))
494 #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8))
495 #define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8))
496 #define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8))
497 #define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8))
498 #define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8))
499 #define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8))
500 #define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8))
501 #define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8))
502 #define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8))
503 #define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8))
504 #define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8))
505 #define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8))
506 #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8))
507 #define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8))
508 
509 /*
510 ** CAPI3REF: Flags For File Open Operations
511 **
512 ** These bit values are intended for use in the
513 ** 3rd parameter to the [sqlite3_open_v2()] interface and
514 ** in the 4th parameter to the [sqlite3_vfs.xOpen] method.
515 */
516 #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */
517 #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */
518 #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */
519 #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */
520 #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */
521 #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */
522 #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */
523 #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */
524 #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */
525 #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */
526 #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */
527 #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */
528 #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */
529 #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */
530 #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */
531 #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */
532 #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */
533 #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */
534 #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */
535 #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */
536 
537 /* Reserved: 0x00F00000 */
538 
539 /*
540 ** CAPI3REF: Device Characteristics
541 **
542 ** The xDeviceCharacteristics method of the [sqlite3_io_methods]
543 ** object returns an integer which is a vector of these
544 ** bit values expressing I/O characteristics of the mass storage
545 ** device that holds the file that the [sqlite3_io_methods]
546 ** refers to.
547 **
548 ** The SQLITE_IOCAP_ATOMIC property means that all writes of
549 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
550 ** mean that writes of blocks that are nnn bytes in size and
551 ** are aligned to an address which is an integer multiple of
552 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
553 ** that when data is appended to a file, the data is appended
554 ** first then the size of the file is extended, never the other
555 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
556 ** information is written to disk in the same order as calls
557 ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that
558 ** after reboot following a crash or power loss, the only bytes in a
559 ** file that were written at the application level might have changed
560 ** and that adjacent bytes, even bytes within the same sector are
561 ** guaranteed to be unchanged.
562 */
563 #define SQLITE_IOCAP_ATOMIC 0x00000001
564 #define SQLITE_IOCAP_ATOMIC512 0x00000002
565 #define SQLITE_IOCAP_ATOMIC1K 0x00000004
566 #define SQLITE_IOCAP_ATOMIC2K 0x00000008
567 #define SQLITE_IOCAP_ATOMIC4K 0x00000010
568 #define SQLITE_IOCAP_ATOMIC8K 0x00000020
569 #define SQLITE_IOCAP_ATOMIC16K 0x00000040
570 #define SQLITE_IOCAP_ATOMIC32K 0x00000080
571 #define SQLITE_IOCAP_ATOMIC64K 0x00000100
572 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200
573 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400
574 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800
575 #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000
576 
577 /*
578 ** CAPI3REF: File Locking Levels
579 **
580 ** SQLite uses one of these integer values as the second
581 ** argument to calls it makes to the xLock() and xUnlock() methods
582 ** of an [sqlite3_io_methods] object.
583 */
584 #define SQLITE_LOCK_NONE 0
585 #define SQLITE_LOCK_SHARED 1
586 #define SQLITE_LOCK_RESERVED 2
587 #define SQLITE_LOCK_PENDING 3
588 #define SQLITE_LOCK_EXCLUSIVE 4
589 
590 /*
591 ** CAPI3REF: Synchronization Type Flags
592 **
593 ** When SQLite invokes the xSync() method of an
594 ** [sqlite3_io_methods] object it uses a combination of
595 ** these integer values as the second argument.
596 **
597 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
598 ** sync operation only needs to flush data to mass storage. Inode
599 ** information need not be flushed. If the lower four bits of the flag
600 ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics.
601 ** If the lower four bits equal SQLITE_SYNC_FULL, that means
602 ** to use Mac OS X style fullsync instead of fsync().
603 **
604 ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags
605 ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL
606 ** settings. The [synchronous pragma] determines when calls to the
607 ** xSync VFS method occur and applies uniformly across all platforms.
608 ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how
609 ** energetic or rigorous or forceful the sync operations are and
610 ** only make a difference on Mac OSX for the default SQLite code.
611 ** (Third-party VFS implementations might also make the distinction
612 ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the
613 ** operating systems natively supported by SQLite, only Mac OSX
614 ** cares about the difference.)
615 */
616 #define SQLITE_SYNC_NORMAL 0x00002
617 #define SQLITE_SYNC_FULL 0x00003
618 #define SQLITE_SYNC_DATAONLY 0x00010
619 
620 /*
621 ** CAPI3REF: OS Interface Open File Handle
622 **
623 ** An [sqlite3_file] object represents an open file in the
624 ** [sqlite3_vfs | OS interface layer]. Individual OS interface
625 ** implementations will
626 ** want to subclass this object by appending additional fields
627 ** for their own use. The pMethods entry is a pointer to an
628 ** [sqlite3_io_methods] object that defines methods for performing
629 ** I/O operations on the open file.
630 */
631 typedef struct sqlite3_file sqlite3_file;
632 struct sqlite3_file {
633  const struct sqlite3_io_methods *pMethods; /* Methods for an open file */
634 };
635 
636 /*
637 ** CAPI3REF: OS Interface File Virtual Methods Object
638 **
639 ** Every file opened by the [sqlite3_vfs.xOpen] method populates an
640 ** [sqlite3_file] object (or, more commonly, a subclass of the
641 ** [sqlite3_file] object) with a pointer to an instance of this object.
642 ** This object defines the methods used to perform various operations
643 ** against the open file represented by the [sqlite3_file] object.
644 **
645 ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element
646 ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method
647 ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The
648 ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen]
649 ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element
650 ** to NULL.
651 **
652 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
653 ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync().
654 ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY]
655 ** flag may be ORed in to indicate that only the data of the file
656 ** and not its inode needs to be synced.
657 **
658 ** The integer values to xLock() and xUnlock() are one of
659 ** <ul>
660 ** <li> [SQLITE_LOCK_NONE],
661 ** <li> [SQLITE_LOCK_SHARED],
662 ** <li> [SQLITE_LOCK_RESERVED],
663 ** <li> [SQLITE_LOCK_PENDING], or
664 ** <li> [SQLITE_LOCK_EXCLUSIVE].
665 ** </ul>
666 ** xLock() increases the lock. xUnlock() decreases the lock.
667 ** The xCheckReservedLock() method checks whether any database connection,
668 ** either in this process or in some other process, is holding a RESERVED,
669 ** PENDING, or EXCLUSIVE lock on the file. It returns true
670 ** if such a lock exists and false otherwise.
671 **
672 ** The xFileControl() method is a generic interface that allows custom
673 ** VFS implementations to directly control an open file using the
674 ** [sqlite3_file_control()] interface. The second "op" argument is an
675 ** integer opcode. The third argument is a generic pointer intended to
676 ** point to a structure that may contain arguments or space in which to
677 ** write return values. Potential uses for xFileControl() might be
678 ** functions to enable blocking locks with timeouts, to change the
679 ** locking strategy (for example to use dot-file locks), to inquire
680 ** about the status of a lock, or to break stale locks. The SQLite
681 ** core reserves all opcodes less than 100 for its own use.
682 ** A [SQLITE_FCNTL_LOCKSTATE | list of opcodes] less than 100 is available.
683 ** Applications that define a custom xFileControl method should use opcodes
684 ** greater than 100 to avoid conflicts. VFS implementations should
685 ** return [SQLITE_NOTFOUND] for file control opcodes that they do not
686 ** recognize.
687 **
688 ** The xSectorSize() method returns the sector size of the
689 ** device that underlies the file. The sector size is the
690 ** minimum write that can be performed without disturbing
691 ** other bytes in the file. The xDeviceCharacteristics()
692 ** method returns a bit vector describing behaviors of the
693 ** underlying device:
694 **
695 ** <ul>
696 ** <li> [SQLITE_IOCAP_ATOMIC]
697 ** <li> [SQLITE_IOCAP_ATOMIC512]
698 ** <li> [SQLITE_IOCAP_ATOMIC1K]
699 ** <li> [SQLITE_IOCAP_ATOMIC2K]
700 ** <li> [SQLITE_IOCAP_ATOMIC4K]
701 ** <li> [SQLITE_IOCAP_ATOMIC8K]
702 ** <li> [SQLITE_IOCAP_ATOMIC16K]
703 ** <li> [SQLITE_IOCAP_ATOMIC32K]
704 ** <li> [SQLITE_IOCAP_ATOMIC64K]
705 ** <li> [SQLITE_IOCAP_SAFE_APPEND]
706 ** <li> [SQLITE_IOCAP_SEQUENTIAL]
707 ** </ul>
708 **
709 ** The SQLITE_IOCAP_ATOMIC property means that all writes of
710 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
711 ** mean that writes of blocks that are nnn bytes in size and
712 ** are aligned to an address which is an integer multiple of
713 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
714 ** that when data is appended to a file, the data is appended
715 ** first then the size of the file is extended, never the other
716 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
717 ** information is written to disk in the same order as calls
718 ** to xWrite().
719 **
720 ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill
721 ** in the unread portions of the buffer with zeros. A VFS that
722 ** fails to zero-fill short reads might seem to work. However,
723 ** failure to zero-fill short reads will eventually lead to
724 ** database corruption.
725 */
727 struct sqlite3_io_methods {
728  int iVersion;
729  int (*xClose)(sqlite3_file*);
730  int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
731  int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
732  int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
733  int (*xSync)(sqlite3_file*, int flags);
734  int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);
735  int (*xLock)(sqlite3_file*, int);
736  int (*xUnlock)(sqlite3_file*, int);
737  int (*xCheckReservedLock)(sqlite3_file*, int *pResOut);
738  int (*xFileControl)(sqlite3_file*, int op, void *pArg);
739  int (*xSectorSize)(sqlite3_file*);
740  int (*xDeviceCharacteristics)(sqlite3_file*);
741  /* Methods above are valid for version 1 */
742  int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
743  int (*xShmLock)(sqlite3_file*, int offset, int n, int flags);
744  void (*xShmBarrier)(sqlite3_file*);
745  int (*xShmUnmap)(sqlite3_file*, int deleteFlag);
746  /* Methods above are valid for version 2 */
747  int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp);
748  int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p);
749  /* Methods above are valid for version 3 */
750  /* Additional methods may be added in future releases */
751 };
752 
753 /*
754 ** CAPI3REF: Standard File Control Opcodes
755 **
756 ** These integer constants are opcodes for the xFileControl method
757 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
758 ** interface.
759 **
760 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This
761 ** opcode causes the xFileControl method to write the current state of
762 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
763 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
764 ** into an integer that the pArg argument points to. This capability
765 ** is used during testing and only needs to be supported when SQLITE_TEST
766 ** is defined.
767 ** <ul>
768 ** <li>[[SQLITE_FCNTL_SIZE_HINT]]
769 ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
770 ** layer a hint of how large the database file will grow to be during the
771 ** current transaction. This hint is not guaranteed to be accurate but it
772 ** is often close. The underlying VFS might choose to preallocate database
773 ** file space based on this hint in order to help writes to the database
774 ** file run faster.
775 **
776 ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]]
777 ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
778 ** extends and truncates the database file in chunks of a size specified
779 ** by the user. The fourth argument to [sqlite3_file_control()] should
780 ** point to an integer (type int) containing the new chunk-size to use
781 ** for the nominated database. Allocating database file space in large
782 ** chunks (say 1MB at a time), may reduce file-system fragmentation and
783 ** improve performance on some systems.
784 **
785 ** <li>[[SQLITE_FCNTL_FILE_POINTER]]
786 ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
787 ** to the [sqlite3_file] object associated with a particular database
788 ** connection. See the [sqlite3_file_control()] documentation for
789 ** additional information.
790 **
791 ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]]
792 ** ^(The [SQLITE_FCNTL_SYNC_OMITTED] opcode is generated internally by
793 ** SQLite and sent to all VFSes in place of a call to the xSync method
794 ** when the database connection has [PRAGMA synchronous] set to OFF.)^
795 ** Some specialized VFSes need this signal in order to operate correctly
796 ** when [PRAGMA synchronous | PRAGMA synchronous=OFF] is set, but most
797 ** VFSes do not need this signal and should silently ignore this opcode.
798 ** Applications should not call [sqlite3_file_control()] with this
799 ** opcode as doing so may disrupt the operation of the specialized VFSes
800 ** that do require it.
801 **
802 ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]]
803 ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic
804 ** retry counts and intervals for certain disk I/O operations for the
805 ** windows [VFS] in order to provide robustness in the presence of
806 ** anti-virus programs. By default, the windows VFS will retry file read,
807 ** file write, and file delete operations up to 10 times, with a delay
808 ** of 25 milliseconds before the first retry and with the delay increasing
809 ** by an additional 25 milliseconds with each subsequent retry. This
810 ** opcode allows these two values (10 retries and 25 milliseconds of delay)
811 ** to be adjusted. The values are changed for all database connections
812 ** within the same process. The argument is a pointer to an array of two
813 ** integers where the first integer i the new retry count and the second
814 ** integer is the delay. If either integer is negative, then the setting
815 ** is not changed but instead the prior value of that setting is written
816 ** into the array entry, allowing the current retry settings to be
817 ** interrogated. The zDbName parameter is ignored.
818 **
819 ** <li>[[SQLITE_FCNTL_PERSIST_WAL]]
820 ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the
821 ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary
822 ** write ahead log and shared memory files used for transaction control
823 ** are automatically deleted when the latest connection to the database
824 ** closes. Setting persistent WAL mode causes those files to persist after
825 ** close. Persisting the files is useful when other processes that do not
826 ** have write permission on the directory containing the database file want
827 ** to read the database file, as the WAL and shared memory files must exist
828 ** in order for the database to be readable. The fourth parameter to
829 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
830 ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent
831 ** WAL mode. If the integer is -1, then it is overwritten with the current
832 ** WAL persistence setting.
833 **
834 ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]]
835 ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the
836 ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting
837 ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the
838 ** xDeviceCharacteristics methods. The fourth parameter to
839 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
840 ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage
841 ** mode. If the integer is -1, then it is overwritten with the current
842 ** zero-damage mode setting.
843 **
844 ** <li>[[SQLITE_FCNTL_OVERWRITE]]
845 ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening
846 ** a write transaction to indicate that, unless it is rolled back for some
847 ** reason, the entire database file will be overwritten by the current
848 ** transaction. This is used by VACUUM operations.
849 **
850 ** <li>[[SQLITE_FCNTL_VFSNAME]]
851 ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of
852 ** all [VFSes] in the VFS stack. The names are of all VFS shims and the
853 ** final bottom-level VFS are written into memory obtained from
854 ** [sqlite3_malloc()] and the result is stored in the char* variable
855 ** that the fourth parameter of [sqlite3_file_control()] points to.
856 ** The caller is responsible for freeing the memory when done. As with
857 ** all file-control actions, there is no guarantee that this will actually
858 ** do anything. Callers should initialize the char* variable to a NULL
859 ** pointer in case this file-control is not implemented. This file-control
860 ** is intended for diagnostic use only.
861 **
862 ** <li>[[SQLITE_FCNTL_PRAGMA]]
863 ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA]
864 ** file control is sent to the open [sqlite3_file] object corresponding
865 ** to the database file to which the pragma statement refers. ^The argument
866 ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of
867 ** pointers to strings (char**) in which the second element of the array
868 ** is the name of the pragma and the third element is the argument to the
869 ** pragma or NULL if the pragma has no argument. ^The handler for an
870 ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element
871 ** of the char** argument point to a string obtained from [sqlite3_mprintf()]
872 ** or the equivalent and that string will become the result of the pragma or
873 ** the error message if the pragma fails. ^If the
874 ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal
875 ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA]
876 ** file control returns [SQLITE_OK], then the parser assumes that the
877 ** VFS has handled the PRAGMA itself and the parser generates a no-op
878 ** prepared statement. ^If the [SQLITE_FCNTL_PRAGMA] file control returns
879 ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means
880 ** that the VFS encountered an error while handling the [PRAGMA] and the
881 ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA]
882 ** file control occurs at the beginning of pragma statement analysis and so
883 ** it is able to override built-in [PRAGMA] statements.
884 **
885 ** <li>[[SQLITE_FCNTL_BUSYHANDLER]]
886 ** ^The [SQLITE_FCNTL_BUSYHANDLER]
887 ** file-control may be invoked by SQLite on the database file handle
888 ** shortly after it is opened in order to provide a custom VFS with access
889 ** to the connections busy-handler callback. The argument is of type (void **)
890 ** - an array of two (void *) values. The first (void *) actually points
891 ** to a function of type (int (*)(void *)). In order to invoke the connections
892 ** busy-handler, this function should be invoked with the second (void *) in
893 ** the array as the only argument. If it returns non-zero, then the operation
894 ** should be retried. If it returns zero, the custom VFS should abandon the
895 ** current operation.
896 **
897 ** <li>[[SQLITE_FCNTL_TEMPFILENAME]]
898 ** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control
899 ** to have SQLite generate a
900 ** temporary filename using the same algorithm that is followed to generate
901 ** temporary filenames for TEMP tables and other internal uses. The
902 ** argument should be a char** which will be filled with the filename
903 ** written into memory obtained from [sqlite3_malloc()]. The caller should
904 ** invoke [sqlite3_free()] on the result to avoid a memory leak.
905 **
906 ** <li>[[SQLITE_FCNTL_MMAP_SIZE]]
907 ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the
908 ** maximum number of bytes that will be used for memory-mapped I/O.
909 ** The argument is a pointer to a value of type sqlite3_int64 that
910 ** is an advisory maximum number of bytes in the file to memory map. The
911 ** pointer is overwritten with the old value. The limit is not changed if
912 ** the value originally pointed to is negative, and so the current limit
913 ** can be queried by passing in a pointer to a negative number. This
914 ** file-control is used internally to implement [PRAGMA mmap_size].
915 **
916 ** <li>[[SQLITE_FCNTL_TRACE]]
917 ** The [SQLITE_FCNTL_TRACE] file control provides advisory information
918 ** to the VFS about what the higher layers of the SQLite stack are doing.
919 ** This file control is used by some VFS activity tracing [shims].
920 ** The argument is a zero-terminated string. Higher layers in the
921 ** SQLite stack may generate instances of this file control if
922 ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled.
923 **
924 ** </ul>
925 */
926 #define SQLITE_FCNTL_LOCKSTATE 1
927 #define SQLITE_GET_LOCKPROXYFILE 2
928 #define SQLITE_SET_LOCKPROXYFILE 3
929 #define SQLITE_LAST_ERRNO 4
930 #define SQLITE_FCNTL_SIZE_HINT 5
931 #define SQLITE_FCNTL_CHUNK_SIZE 6
932 #define SQLITE_FCNTL_FILE_POINTER 7
933 #define SQLITE_FCNTL_SYNC_OMITTED 8
934 #define SQLITE_FCNTL_WIN32_AV_RETRY 9
935 #define SQLITE_FCNTL_PERSIST_WAL 10
936 #define SQLITE_FCNTL_OVERWRITE 11
937 #define SQLITE_FCNTL_VFSNAME 12
938 #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13
939 #define SQLITE_FCNTL_PRAGMA 14
940 #define SQLITE_FCNTL_BUSYHANDLER 15
941 #define SQLITE_FCNTL_TEMPFILENAME 16
942 #define SQLITE_FCNTL_MMAP_SIZE 18
943 #define SQLITE_FCNTL_TRACE 19
944 
945 /*
946 ** CAPI3REF: Mutex Handle
947 **
948 ** The mutex module within SQLite defines [sqlite3_mutex] to be an
949 ** abstract type for a mutex object. The SQLite core never looks
950 ** at the internal representation of an [sqlite3_mutex]. It only
951 ** deals with pointers to the [sqlite3_mutex] object.
952 **
953 ** Mutexes are created using [sqlite3_mutex_alloc()].
954 */
956 
957 /*
958 ** CAPI3REF: OS Interface Object
959 **
960 ** An instance of the sqlite3_vfs object defines the interface between
961 ** the SQLite core and the underlying operating system. The "vfs"
962 ** in the name of the object stands for "virtual file system". See
963 ** the [VFS | VFS documentation] for further information.
964 **
965 ** The value of the iVersion field is initially 1 but may be larger in
966 ** future versions of SQLite. Additional fields may be appended to this
967 ** object when the iVersion value is increased. Note that the structure
968 ** of the sqlite3_vfs object changes in the transaction between
969 ** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not
970 ** modified.
971 **
972 ** The szOsFile field is the size of the subclassed [sqlite3_file]
973 ** structure used by this VFS. mxPathname is the maximum length of
974 ** a pathname in this VFS.
975 **
976 ** Registered sqlite3_vfs objects are kept on a linked list formed by
977 ** the pNext pointer. The [sqlite3_vfs_register()]
978 ** and [sqlite3_vfs_unregister()] interfaces manage this list
979 ** in a thread-safe way. The [sqlite3_vfs_find()] interface
980 ** searches the list. Neither the application code nor the VFS
981 ** implementation should use the pNext pointer.
982 **
983 ** The pNext field is the only field in the sqlite3_vfs
984 ** structure that SQLite will ever modify. SQLite will only access
985 ** or modify this field while holding a particular static mutex.
986 ** The application should never modify anything within the sqlite3_vfs
987 ** object once the object has been registered.
988 **
989 ** The zName field holds the name of the VFS module. The name must
990 ** be unique across all VFS modules.
991 **
992 ** [[sqlite3_vfs.xOpen]]
993 ** ^SQLite guarantees that the zFilename parameter to xOpen
994 ** is either a NULL pointer or string obtained
995 ** from xFullPathname() with an optional suffix added.
996 ** ^If a suffix is added to the zFilename parameter, it will
997 ** consist of a single "-" character followed by no more than
998 ** 11 alphanumeric and/or "-" characters.
999 ** ^SQLite further guarantees that
1000 ** the string will be valid and unchanged until xClose() is
1001 ** called. Because of the previous sentence,
1002 ** the [sqlite3_file] can safely store a pointer to the
1003 ** filename if it needs to remember the filename for some reason.
1004 ** If the zFilename parameter to xOpen is a NULL pointer then xOpen
1005 ** must invent its own temporary name for the file. ^Whenever the
1006 ** xFilename parameter is NULL it will also be the case that the
1007 ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
1008 **
1009 ** The flags argument to xOpen() includes all bits set in
1010 ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()]
1011 ** or [sqlite3_open16()] is used, then flags includes at least
1012 ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE].
1013 ** If xOpen() opens a file read-only then it sets *pOutFlags to
1014 ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set.
1015 **
1016 ** ^(SQLite will also add one of the following flags to the xOpen()
1017 ** call, depending on the object being opened:
1018 **
1019 ** <ul>
1020 ** <li> [SQLITE_OPEN_MAIN_DB]
1021 ** <li> [SQLITE_OPEN_MAIN_JOURNAL]
1022 ** <li> [SQLITE_OPEN_TEMP_DB]
1023 ** <li> [SQLITE_OPEN_TEMP_JOURNAL]
1024 ** <li> [SQLITE_OPEN_TRANSIENT_DB]
1025 ** <li> [SQLITE_OPEN_SUBJOURNAL]
1026 ** <li> [SQLITE_OPEN_MASTER_JOURNAL]
1027 ** <li> [SQLITE_OPEN_WAL]
1028 ** </ul>)^
1029 **
1030 ** The file I/O implementation can use the object type flags to
1031 ** change the way it deals with files. For example, an application
1032 ** that does not care about crash recovery or rollback might make
1033 ** the open of a journal file a no-op. Writes to this journal would
1034 ** also be no-ops, and any attempt to read the journal would return
1035 ** SQLITE_IOERR. Or the implementation might recognize that a database
1036 ** file will be doing page-aligned sector reads and writes in a random
1037 ** order and set up its I/O subsystem accordingly.
1038 **
1039 ** SQLite might also add one of the following flags to the xOpen method:
1040 **
1041 ** <ul>
1042 ** <li> [SQLITE_OPEN_DELETEONCLOSE]
1043 ** <li> [SQLITE_OPEN_EXCLUSIVE]
1044 ** </ul>
1045 **
1046 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
1047 ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE]
1048 ** will be set for TEMP databases and their journals, transient
1049 ** databases, and subjournals.
1050 **
1051 ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction
1052 ** with the [SQLITE_OPEN_CREATE] flag, which are both directly
1053 ** analogous to the O_EXCL and O_CREAT flags of the POSIX open()
1054 ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the
1055 ** SQLITE_OPEN_CREATE, is used to indicate that file should always
1056 ** be created, and that it is an error if it already exists.
1057 ** It is <i>not</i> used to indicate the file should be opened
1058 ** for exclusive access.
1059 **
1060 ** ^At least szOsFile bytes of memory are allocated by SQLite
1061 ** to hold the [sqlite3_file] structure passed as the third
1062 ** argument to xOpen. The xOpen method does not have to
1063 ** allocate the structure; it should just fill it in. Note that
1064 ** the xOpen method must set the sqlite3_file.pMethods to either
1065 ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do
1066 ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods
1067 ** element will be valid after xOpen returns regardless of the success
1068 ** or failure of the xOpen call.
1069 **
1070 ** [[sqlite3_vfs.xAccess]]
1071 ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
1072 ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
1073 ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
1074 ** to test whether a file is at least readable. The file can be a
1075 ** directory.
1076 **
1077 ** ^SQLite will always allocate at least mxPathname+1 bytes for the
1078 ** output buffer xFullPathname. The exact size of the output buffer
1079 ** is also passed as a parameter to both methods. If the output buffer
1080 ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
1081 ** handled as a fatal error by SQLite, vfs implementations should endeavor
1082 ** to prevent this by setting mxPathname to a sufficiently large value.
1083 **
1084 ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64()
1085 ** interfaces are not strictly a part of the filesystem, but they are
1086 ** included in the VFS structure for completeness.
1087 ** The xRandomness() function attempts to return nBytes bytes
1088 ** of good-quality randomness into zOut. The return value is
1089 ** the actual number of bytes of randomness obtained.
1090 ** The xSleep() method causes the calling thread to sleep for at
1091 ** least the number of microseconds given. ^The xCurrentTime()
1092 ** method returns a Julian Day Number for the current date and time as
1093 ** a floating point value.
1094 ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian
1095 ** Day Number multiplied by 86400000 (the number of milliseconds in
1096 ** a 24-hour day).
1097 ** ^SQLite will use the xCurrentTimeInt64() method to get the current
1098 ** date and time if that method is available (if iVersion is 2 or
1099 ** greater and the function pointer is not NULL) and will fall back
1100 ** to xCurrentTime() if xCurrentTimeInt64() is unavailable.
1101 **
1102 ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces
1103 ** are not used by the SQLite core. These optional interfaces are provided
1104 ** by some VFSes to facilitate testing of the VFS code. By overriding
1105 ** system calls with functions under its control, a test program can
1106 ** simulate faults and error conditions that would otherwise be difficult
1107 ** or impossible to induce. The set of system calls that can be overridden
1108 ** varies from one VFS to another, and from one version of the same VFS to the
1109 ** next. Applications that use these interfaces must be prepared for any
1110 ** or all of these interfaces to be NULL or for their behavior to change
1111 ** from one release to the next. Applications must not attempt to access
1112 ** any of these methods if the iVersion of the VFS is less than 3.
1113 */
1114 typedef struct sqlite3_vfs sqlite3_vfs;
1115 typedef void (*sqlite3_syscall_ptr)(void);
1116 struct sqlite3_vfs {
1117  int iVersion; /* Structure version number (currently 3) */
1118  int szOsFile; /* Size of subclassed sqlite3_file */
1119  int mxPathname; /* Maximum file pathname length */
1120  sqlite3_vfs *pNext; /* Next registered VFS */
1121  const char *zName; /* Name of this virtual file system */
1122  void *pAppData; /* Pointer to application-specific data */
1123  int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*,
1124  int flags, int *pOutFlags);
1125  int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);
1126  int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);
1127  int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);
1128  void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);
1129  void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
1130  void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);
1131  void (*xDlClose)(sqlite3_vfs*, void*);
1132  int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
1133  int (*xSleep)(sqlite3_vfs*, int microseconds);
1134  int (*xCurrentTime)(sqlite3_vfs*, double*);
1135  int (*xGetLastError)(sqlite3_vfs*, int, char *);
1136  /*
1137  ** The methods above are in version 1 of the sqlite_vfs object
1138  ** definition. Those that follow are added in version 2 or later
1139  */
1140  int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);
1141  /*
1142  ** The methods above are in versions 1 and 2 of the sqlite_vfs object.
1143  ** Those below are for version 3 and greater.
1144  */
1145  int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr);
1146  sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName);
1147  const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName);
1148  /*
1149  ** The methods above are in versions 1 through 3 of the sqlite_vfs object.
1150  ** New fields may be appended in figure versions. The iVersion
1151  ** value will increment whenever this happens.
1152  */
1153 };
1154 
1155 /*
1156 ** CAPI3REF: Flags for the xAccess VFS method
1157 **
1158 ** These integer constants can be used as the third parameter to
1159 ** the xAccess method of an [sqlite3_vfs] object. They determine
1160 ** what kind of permissions the xAccess method is looking for.
1161 ** With SQLITE_ACCESS_EXISTS, the xAccess method
1162 ** simply checks whether the file exists.
1163 ** With SQLITE_ACCESS_READWRITE, the xAccess method
1164 ** checks whether the named directory is both readable and writable
1165 ** (in other words, if files can be added, removed, and renamed within
1166 ** the directory).
1167 ** The SQLITE_ACCESS_READWRITE constant is currently used only by the
1168 ** [temp_store_directory pragma], though this could change in a future
1169 ** release of SQLite.
1170 ** With SQLITE_ACCESS_READ, the xAccess method
1171 ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is
1172 ** currently unused, though it might be used in a future release of
1173 ** SQLite.
1174 */
1175 #define SQLITE_ACCESS_EXISTS 0
1176 #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */
1177 #define SQLITE_ACCESS_READ 2 /* Unused */
1178 
1179 /*
1180 ** CAPI3REF: Flags for the xShmLock VFS method
1181 **
1182 ** These integer constants define the various locking operations
1183 ** allowed by the xShmLock method of [sqlite3_io_methods]. The
1184 ** following are the only legal combinations of flags to the
1185 ** xShmLock method:
1186 **
1187 ** <ul>
1188 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED
1189 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE
1190 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED
1191 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE
1192 ** </ul>
1193 **
1194 ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
1195 ** was given no the corresponding lock.
1196 **
1197 ** The xShmLock method can transition between unlocked and SHARED or
1198 ** between unlocked and EXCLUSIVE. It cannot transition between SHARED
1199 ** and EXCLUSIVE.
1200 */
1201 #define SQLITE_SHM_UNLOCK 1
1202 #define SQLITE_SHM_LOCK 2
1203 #define SQLITE_SHM_SHARED 4
1204 #define SQLITE_SHM_EXCLUSIVE 8
1205 
1206 /*
1207 ** CAPI3REF: Maximum xShmLock index
1208 **
1209 ** The xShmLock method on [sqlite3_io_methods] may use values
1210 ** between 0 and this upper bound as its "offset" argument.
1211 ** The SQLite core will never attempt to acquire or release a
1212 ** lock outside of this range
1213 */
1214 #define SQLITE_SHM_NLOCK 8
1215 
1216 
1217 /*
1218 ** CAPI3REF: Initialize The SQLite Library
1219 **
1220 ** ^The sqlite3_initialize() routine initializes the
1221 ** SQLite library. ^The sqlite3_shutdown() routine
1222 ** deallocates any resources that were allocated by sqlite3_initialize().
1223 ** These routines are designed to aid in process initialization and
1224 ** shutdown on embedded systems. Workstation applications using
1225 ** SQLite normally do not need to invoke either of these routines.
1226 **
1227 ** A call to sqlite3_initialize() is an "effective" call if it is
1228 ** the first time sqlite3_initialize() is invoked during the lifetime of
1229 ** the process, or if it is the first time sqlite3_initialize() is invoked
1230 ** following a call to sqlite3_shutdown(). ^(Only an effective call
1231 ** of sqlite3_initialize() does any initialization. All other calls
1232 ** are harmless no-ops.)^
1233 **
1234 ** A call to sqlite3_shutdown() is an "effective" call if it is the first
1235 ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only
1236 ** an effective call to sqlite3_shutdown() does any deinitialization.
1237 ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
1238 **
1239 ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
1240 ** is not. The sqlite3_shutdown() interface must only be called from a
1241 ** single thread. All open [database connections] must be closed and all
1242 ** other SQLite resources must be deallocated prior to invoking
1243 ** sqlite3_shutdown().
1244 **
1245 ** Among other things, ^sqlite3_initialize() will invoke
1246 ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown()
1247 ** will invoke sqlite3_os_end().
1248 **
1249 ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
1250 ** ^If for some reason, sqlite3_initialize() is unable to initialize
1251 ** the library (perhaps it is unable to allocate a needed resource such
1252 ** as a mutex) it returns an [error code] other than [SQLITE_OK].
1253 **
1254 ** ^The sqlite3_initialize() routine is called internally by many other
1255 ** SQLite interfaces so that an application usually does not need to
1256 ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()]
1257 ** calls sqlite3_initialize() so the SQLite library will be automatically
1258 ** initialized when [sqlite3_open()] is called if it has not be initialized
1259 ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
1260 ** compile-time option, then the automatic calls to sqlite3_initialize()
1261 ** are omitted and the application must call sqlite3_initialize() directly
1262 ** prior to using any other SQLite interface. For maximum portability,
1263 ** it is recommended that applications always invoke sqlite3_initialize()
1264 ** directly prior to using any other SQLite interface. Future releases
1265 ** of SQLite may require this. In other words, the behavior exhibited
1266 ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
1267 ** default behavior in some future release of SQLite.
1268 **
1269 ** The sqlite3_os_init() routine does operating-system specific
1270 ** initialization of the SQLite library. The sqlite3_os_end()
1271 ** routine undoes the effect of sqlite3_os_init(). Typical tasks
1272 ** performed by these routines include allocation or deallocation
1273 ** of static resources, initialization of global variables,
1274 ** setting up a default [sqlite3_vfs] module, or setting up
1275 ** a default configuration using [sqlite3_config()].
1276 **
1277 ** The application should never invoke either sqlite3_os_init()
1278 ** or sqlite3_os_end() directly. The application should only invoke
1279 ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init()
1280 ** interface is called automatically by sqlite3_initialize() and
1281 ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate
1282 ** implementations for sqlite3_os_init() and sqlite3_os_end()
1283 ** are built into SQLite when it is compiled for Unix, Windows, or OS/2.
1284 ** When [custom builds | built for other platforms]
1285 ** (using the [SQLITE_OS_OTHER=1] compile-time
1286 ** option) the application must supply a suitable implementation for
1287 ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied
1288 ** implementation of sqlite3_os_init() or sqlite3_os_end()
1289 ** must return [SQLITE_OK] on success and some other [error code] upon
1290 ** failure.
1291 */
1292 SQLITE_API int sqlite3_initialize(void);
1293 SQLITE_API int sqlite3_shutdown(void);
1294 SQLITE_API int sqlite3_os_init(void);
1295 SQLITE_API int sqlite3_os_end(void);
1296 
1297 /*
1298 ** CAPI3REF: Configuring The SQLite Library
1299 **
1300 ** The sqlite3_config() interface is used to make global configuration
1301 ** changes to SQLite in order to tune SQLite to the specific needs of
1302 ** the application. The default configuration is recommended for most
1303 ** applications and so this routine is usually not necessary. It is
1304 ** provided to support rare applications with unusual needs.
1305 **
1306 ** The sqlite3_config() interface is not threadsafe. The application
1307 ** must insure that no other SQLite interfaces are invoked by other
1308 ** threads while sqlite3_config() is running. Furthermore, sqlite3_config()
1309 ** may only be invoked prior to library initialization using
1310 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
1311 ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
1312 ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE.
1313 ** Note, however, that ^sqlite3_config() can be called as part of the
1314 ** implementation of an application-defined [sqlite3_os_init()].
1315 **
1316 ** The first argument to sqlite3_config() is an integer
1317 ** [configuration option] that determines
1318 ** what property of SQLite is to be configured. Subsequent arguments
1319 ** vary depending on the [configuration option]
1320 ** in the first argument.
1321 **
1322 ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
1323 ** ^If the option is unknown or SQLite is unable to set the option
1324 ** then this routine returns a non-zero [error code].
1325 */
1326 SQLITE_API int sqlite3_config(int, ...);
1327 
1328 /*
1329 ** CAPI3REF: Configure database connections
1330 **
1331 ** The sqlite3_db_config() interface is used to make configuration
1332 ** changes to a [database connection]. The interface is similar to
1333 ** [sqlite3_config()] except that the changes apply to a single
1334 ** [database connection] (specified in the first argument).
1335 **
1336 ** The second argument to sqlite3_db_config(D,V,...) is the
1337 ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code
1338 ** that indicates what aspect of the [database connection] is being configured.
1339 ** Subsequent arguments vary depending on the configuration verb.
1340 **
1341 ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
1342 ** the call is considered successful.
1343 */
1344 SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...);
1345 
1346 /*
1347 ** CAPI3REF: Memory Allocation Routines
1348 **
1349 ** An instance of this object defines the interface between SQLite
1350 ** and low-level memory allocation routines.
1351 **
1352 ** This object is used in only one place in the SQLite interface.
1353 ** A pointer to an instance of this object is the argument to
1354 ** [sqlite3_config()] when the configuration option is
1355 ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC].
1356 ** By creating an instance of this object
1357 ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])
1358 ** during configuration, an application can specify an alternative
1359 ** memory allocation subsystem for SQLite to use for all of its
1360 ** dynamic memory needs.
1361 **
1362 ** Note that SQLite comes with several [built-in memory allocators]
1363 ** that are perfectly adequate for the overwhelming majority of applications
1364 ** and that this object is only useful to a tiny minority of applications
1365 ** with specialized memory allocation requirements. This object is
1366 ** also used during testing of SQLite in order to specify an alternative
1367 ** memory allocator that simulates memory out-of-memory conditions in
1368 ** order to verify that SQLite recovers gracefully from such
1369 ** conditions.
1370 **
1371 ** The xMalloc, xRealloc, and xFree methods must work like the
1372 ** malloc(), realloc() and free() functions from the standard C library.
1373 ** ^SQLite guarantees that the second argument to
1374 ** xRealloc is always a value returned by a prior call to xRoundup.
1375 **
1376 ** xSize should return the allocated size of a memory allocation
1377 ** previously obtained from xMalloc or xRealloc. The allocated size
1378 ** is always at least as big as the requested size but may be larger.
1379 **
1380 ** The xRoundup method returns what would be the allocated size of
1381 ** a memory allocation given a particular requested size. Most memory
1382 ** allocators round up memory allocations at least to the next multiple
1383 ** of 8. Some allocators round up to a larger multiple or to a power of 2.
1384 ** Every memory allocation request coming in through [sqlite3_malloc()]
1385 ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0,
1386 ** that causes the corresponding memory allocation to fail.
1387 **
1388 ** The xInit method initializes the memory allocator. For example,
1389 ** it might allocate any require mutexes or initialize internal data
1390 ** structures. The xShutdown method is invoked (indirectly) by
1391 ** [sqlite3_shutdown()] and should deallocate any resources acquired
1392 ** by xInit. The pAppData pointer is used as the only parameter to
1393 ** xInit and xShutdown.
1394 **
1395 ** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes
1396 ** the xInit method, so the xInit method need not be threadsafe. The
1397 ** xShutdown method is only called from [sqlite3_shutdown()] so it does
1398 ** not need to be threadsafe either. For all other methods, SQLite
1399 ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
1400 ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
1401 ** it is by default) and so the methods are automatically serialized.
1402 ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other
1403 ** methods must be threadsafe or else make their own arrangements for
1404 ** serialization.
1405 **
1406 ** SQLite will never invoke xInit() more than once without an intervening
1407 ** call to xShutdown().
1408 */
1410 struct sqlite3_mem_methods {
1411  void *(*xMalloc)(int); /* Memory allocation function */
1412  void (*xFree)(void*); /* Free a prior allocation */
1413  void *(*xRealloc)(void*,int); /* Resize an allocation */
1414  int (*xSize)(void*); /* Return the size of an allocation */
1415  int (*xRoundup)(int); /* Round up request size to allocation size */
1416  int (*xInit)(void*); /* Initialize the memory allocator */
1417  void (*xShutdown)(void*); /* Deinitialize the memory allocator */
1418  void *pAppData; /* Argument to xInit() and xShutdown() */
1419 };
1420 
1421 /*
1422 ** CAPI3REF: Configuration Options
1423 ** KEYWORDS: {configuration option}
1424 **
1425 ** These constants are the available integer configuration options that
1426 ** can be passed as the first argument to the [sqlite3_config()] interface.
1427 **
1428 ** New configuration options may be added in future releases of SQLite.
1429 ** Existing configuration options might be discontinued. Applications
1430 ** should check the return code from [sqlite3_config()] to make sure that
1431 ** the call worked. The [sqlite3_config()] interface will return a
1432 ** non-zero [error code] if a discontinued or unsupported configuration option
1433 ** is invoked.
1434 **
1435 ** <dl>
1436 ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
1437 ** <dd>There are no arguments to this option. ^This option sets the
1438 ** [threading mode] to Single-thread. In other words, it disables
1439 ** all mutexing and puts SQLite into a mode where it can only be used
1440 ** by a single thread. ^If SQLite is compiled with
1441 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1442 ** it is not possible to change the [threading mode] from its default
1443 ** value of Single-thread and so [sqlite3_config()] will return
1444 ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD
1445 ** configuration option.</dd>
1446 **
1447 ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt>
1448 ** <dd>There are no arguments to this option. ^This option sets the
1449 ** [threading mode] to Multi-thread. In other words, it disables
1450 ** mutexing on [database connection] and [prepared statement] objects.
1451 ** The application is responsible for serializing access to
1452 ** [database connections] and [prepared statements]. But other mutexes
1453 ** are enabled so that SQLite will be safe to use in a multi-threaded
1454 ** environment as long as no two threads attempt to use the same
1455 ** [database connection] at the same time. ^If SQLite is compiled with
1456 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1457 ** it is not possible to set the Multi-thread [threading mode] and
1458 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1459 ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
1460 **
1461 ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt>
1462 ** <dd>There are no arguments to this option. ^This option sets the
1463 ** [threading mode] to Serialized. In other words, this option enables
1464 ** all mutexes including the recursive
1465 ** mutexes on [database connection] and [prepared statement] objects.
1466 ** In this mode (which is the default when SQLite is compiled with
1467 ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
1468 ** to [database connections] and [prepared statements] so that the
1469 ** application is free to use the same [database connection] or the
1470 ** same [prepared statement] in different threads at the same time.
1471 ** ^If SQLite is compiled with
1472 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1473 ** it is not possible to set the Serialized [threading mode] and
1474 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1475 ** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
1476 **
1477 ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>
1478 ** <dd> ^(This option takes a single argument which is a pointer to an
1479 ** instance of the [sqlite3_mem_methods] structure. The argument specifies
1480 ** alternative low-level memory allocation routines to be used in place of
1481 ** the memory allocation routines built into SQLite.)^ ^SQLite makes
1482 ** its own private copy of the content of the [sqlite3_mem_methods] structure
1483 ** before the [sqlite3_config()] call returns.</dd>
1484 **
1485 ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>
1486 ** <dd> ^(This option takes a single argument which is a pointer to an
1487 ** instance of the [sqlite3_mem_methods] structure. The [sqlite3_mem_methods]
1488 ** structure is filled with the currently defined memory allocation routines.)^
1489 ** This option can be used to overload the default memory allocation
1490 ** routines with a wrapper that simulations memory allocation failure or
1491 ** tracks memory usage, for example. </dd>
1492 **
1493 ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
1494 ** <dd> ^This option takes single argument of type int, interpreted as a
1495 ** boolean, which enables or disables the collection of memory allocation
1496 ** statistics. ^(When memory allocation statistics are disabled, the
1497 ** following SQLite interfaces become non-operational:
1498 ** <ul>
1499 ** <li> [sqlite3_memory_used()]
1500 ** <li> [sqlite3_memory_highwater()]
1501 ** <li> [sqlite3_soft_heap_limit64()]
1502 ** <li> [sqlite3_status()]
1503 ** </ul>)^
1504 ** ^Memory allocation statistics are enabled by default unless SQLite is
1505 ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
1506 ** allocation statistics are disabled by default.
1507 ** </dd>
1508 **
1509 ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>
1510 ** <dd> ^This option specifies a static memory buffer that SQLite can use for
1511 ** scratch memory. There are three arguments: A pointer an 8-byte
1512 ** aligned memory buffer from which the scratch allocations will be
1513 ** drawn, the size of each scratch allocation (sz),
1514 ** and the maximum number of scratch allocations (N). The sz
1515 ** argument must be a multiple of 16.
1516 ** The first argument must be a pointer to an 8-byte aligned buffer
1517 ** of at least sz*N bytes of memory.
1518 ** ^SQLite will use no more than two scratch buffers per thread. So
1519 ** N should be set to twice the expected maximum number of threads.
1520 ** ^SQLite will never require a scratch buffer that is more than 6
1521 ** times the database page size. ^If SQLite needs needs additional
1522 ** scratch memory beyond what is provided by this configuration option, then
1523 ** [sqlite3_malloc()] will be used to obtain the memory needed.</dd>
1524 **
1525 ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
1526 ** <dd> ^This option specifies a static memory buffer that SQLite can use for
1527 ** the database page cache with the default page cache implementation.
1528 ** This configuration should not be used if an application-define page
1529 ** cache implementation is loaded using the SQLITE_CONFIG_PCACHE2 option.
1530 ** There are three arguments to this option: A pointer to 8-byte aligned
1531 ** memory, the size of each page buffer (sz), and the number of pages (N).
1532 ** The sz argument should be the size of the largest database page
1533 ** (a power of two between 512 and 32768) plus a little extra for each
1534 ** page header. ^The page header size is 20 to 40 bytes depending on
1535 ** the host architecture. ^It is harmless, apart from the wasted memory,
1536 ** to make sz a little too large. The first
1537 ** argument should point to an allocation of at least sz*N bytes of memory.
1538 ** ^SQLite will use the memory provided by the first argument to satisfy its
1539 ** memory needs for the first N pages that it adds to cache. ^If additional
1540 ** page cache memory is needed beyond what is provided by this option, then
1541 ** SQLite goes to [sqlite3_malloc()] for the additional storage space.
1542 ** The pointer in the first argument must
1543 ** be aligned to an 8-byte boundary or subsequent behavior of SQLite
1544 ** will be undefined.</dd>
1545 **
1546 ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
1547 ** <dd> ^This option specifies a static memory buffer that SQLite will use
1548 ** for all of its dynamic memory allocation needs beyond those provided
1549 ** for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE].
1550 ** There are three arguments: An 8-byte aligned pointer to the memory,
1551 ** the number of bytes in the memory buffer, and the minimum allocation size.
1552 ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
1553 ** to using its default memory allocator (the system malloc() implementation),
1554 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the
1555 ** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or
1556 ** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory
1557 ** allocator is engaged to handle all of SQLites memory allocation needs.
1558 ** The first pointer (the memory pointer) must be aligned to an 8-byte
1559 ** boundary or subsequent behavior of SQLite will be undefined.
1560 ** The minimum allocation size is capped at 2**12. Reasonable values
1561 ** for the minimum allocation size are 2**5 through 2**8.</dd>
1562 **
1563 ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
1564 ** <dd> ^(This option takes a single argument which is a pointer to an
1565 ** instance of the [sqlite3_mutex_methods] structure. The argument specifies
1566 ** alternative low-level mutex routines to be used in place
1567 ** the mutex routines built into SQLite.)^ ^SQLite makes a copy of the
1568 ** content of the [sqlite3_mutex_methods] structure before the call to
1569 ** [sqlite3_config()] returns. ^If SQLite is compiled with
1570 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1571 ** the entire mutexing subsystem is omitted from the build and hence calls to
1572 ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
1573 ** return [SQLITE_ERROR].</dd>
1574 **
1575 ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>
1576 ** <dd> ^(This option takes a single argument which is a pointer to an
1577 ** instance of the [sqlite3_mutex_methods] structure. The
1578 ** [sqlite3_mutex_methods]
1579 ** structure is filled with the currently defined mutex routines.)^
1580 ** This option can be used to overload the default mutex allocation
1581 ** routines with a wrapper used to track mutex usage for performance
1582 ** profiling or testing, for example. ^If SQLite is compiled with
1583 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1584 ** the entire mutexing subsystem is omitted from the build and hence calls to
1585 ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
1586 ** return [SQLITE_ERROR].</dd>
1587 **
1588 ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>
1589 ** <dd> ^(This option takes two arguments that determine the default
1590 ** memory allocation for the lookaside memory allocator on each
1591 ** [database connection]. The first argument is the
1592 ** size of each lookaside buffer slot and the second is the number of
1593 ** slots allocated to each database connection.)^ ^(This option sets the
1594 ** <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE]
1595 ** verb to [sqlite3_db_config()] can be used to change the lookaside
1596 ** configuration on individual connections.)^ </dd>
1597 **
1598 ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt>
1599 ** <dd> ^(This option takes a single argument which is a pointer to
1600 ** an [sqlite3_pcache_methods2] object. This object specifies the interface
1601 ** to a custom page cache implementation.)^ ^SQLite makes a copy of the
1602 ** object and uses it for page cache memory allocations.</dd>
1603 **
1604 ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt>
1605 ** <dd> ^(This option takes a single argument which is a pointer to an
1606 ** [sqlite3_pcache_methods2] object. SQLite copies of the current
1607 ** page cache implementation into that object.)^ </dd>
1608 **
1609 ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
1610 ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite
1611 ** global [error log].
1612 ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
1613 ** function with a call signature of void(*)(void*,int,const char*),
1614 ** and a pointer to void. ^If the function pointer is not NULL, it is
1615 ** invoked by [sqlite3_log()] to process each logging event. ^If the
1616 ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.
1617 ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is
1618 ** passed through as the first parameter to the application-defined logger
1619 ** function whenever that function is invoked. ^The second parameter to
1620 ** the logger function is a copy of the first parameter to the corresponding
1621 ** [sqlite3_log()] call and is intended to be a [result code] or an
1622 ** [extended result code]. ^The third parameter passed to the logger is
1623 ** log message after formatting via [sqlite3_snprintf()].
1624 ** The SQLite logging interface is not reentrant; the logger function
1625 ** supplied by the application must not invoke any SQLite interface.
1626 ** In a multi-threaded application, the application-defined logger
1627 ** function must be threadsafe. </dd>
1628 **
1629 ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
1630 ** <dd>^(This option takes a single argument of type int. If non-zero, then
1631 ** URI handling is globally enabled. If the parameter is zero, then URI handling
1632 ** is globally disabled.)^ ^If URI handling is globally enabled, all filenames
1633 ** passed to [sqlite3_open()], [sqlite3_open_v2()], [sqlite3_open16()] or
1634 ** specified as part of [ATTACH] commands are interpreted as URIs, regardless
1635 ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
1636 ** connection is opened. ^If it is globally disabled, filenames are
1637 ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
1638 ** database connection is opened. ^(By default, URI handling is globally
1639 ** disabled. The default value may be changed by compiling with the
1640 ** [SQLITE_USE_URI] symbol defined.)^
1641 **
1642 ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN
1643 ** <dd>^This option takes a single integer argument which is interpreted as
1644 ** a boolean in order to enable or disable the use of covering indices for
1645 ** full table scans in the query optimizer. ^The default setting is determined
1646 ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on"
1647 ** if that compile-time option is omitted.
1648 ** The ability to disable the use of covering indices for full table scans
1649 ** is because some incorrectly coded legacy applications might malfunction
1650 ** when the optimization is enabled. Providing the ability to
1651 ** disable the optimization allows the older, buggy application code to work
1652 ** without change even with newer versions of SQLite.
1653 **
1654 ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]]
1655 ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE
1656 ** <dd> These options are obsolete and should not be used by new code.
1657 ** They are retained for backwards compatibility but are now no-ops.
1658 ** </dd>
1659 **
1660 ** [[SQLITE_CONFIG_SQLLOG]]
1661 ** <dt>SQLITE_CONFIG_SQLLOG
1662 ** <dd>This option is only available if sqlite is compiled with the
1663 ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should
1664 ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int).
1665 ** The second should be of type (void*). The callback is invoked by the library
1666 ** in three separate circumstances, identified by the value passed as the
1667 ** fourth parameter. If the fourth parameter is 0, then the database connection
1668 ** passed as the second argument has just been opened. The third argument
1669 ** points to a buffer containing the name of the main database file. If the
1670 ** fourth parameter is 1, then the SQL statement that the third parameter
1671 ** points to has just been executed. Or, if the fourth parameter is 2, then
1672 ** the connection being passed as the second parameter is being closed. The
1673 ** third parameter is passed NULL In this case. An example of using this
1674 ** configuration option can be seen in the "test_sqllog.c" source file in
1675 ** the canonical SQLite source tree.</dd>
1676 **
1677 ** [[SQLITE_CONFIG_MMAP_SIZE]]
1678 ** <dt>SQLITE_CONFIG_MMAP_SIZE
1679 ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values
1680 ** that are the default mmap size limit (the default setting for
1681 ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit.
1682 ** ^The default setting can be overridden by each database connection using
1683 ** either the [PRAGMA mmap_size] command, or by using the
1684 ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size
1685 ** cannot be changed at run-time. Nor may the maximum allowed mmap size
1686 ** exceed the compile-time maximum mmap size set by the
1687 ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^
1688 ** ^If either argument to this option is negative, then that argument is
1689 ** changed to its compile-time default.
1690 **
1691 ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]]
1692 ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE
1693 ** <dd>^This option is only available if SQLite is compiled for Windows
1694 ** with the [SQLITE_WIN32_MALLOC] pre-processor macro defined.
1695 ** SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value
1696 ** that specifies the maximum size of the created heap.
1697 ** </dl>
1698 */
1699 #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */
1700 #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */
1701 #define SQLITE_CONFIG_SERIALIZED 3 /* nil */
1702 #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */
1703 #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */
1704 #define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */
1705 #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */
1706 #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */
1707 #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */
1708 #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */
1709 #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */
1710 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */
1711 #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */
1712 #define SQLITE_CONFIG_PCACHE 14 /* no-op */
1713 #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */
1714 #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */
1715 #define SQLITE_CONFIG_URI 17 /* int */
1716 #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */
1717 #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */
1718 #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */
1719 #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */
1720 #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */
1721 #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */
1722 
1723 /*
1724 ** CAPI3REF: Database Connection Configuration Options
1725 **
1726 ** These constants are the available integer configuration options that
1727 ** can be passed as the second argument to the [sqlite3_db_config()] interface.
1728 **
1729 ** New configuration options may be added in future releases of SQLite.
1730 ** Existing configuration options might be discontinued. Applications
1731 ** should check the return code from [sqlite3_db_config()] to make sure that
1732 ** the call worked. ^The [sqlite3_db_config()] interface will return a
1733 ** non-zero [error code] if a discontinued or unsupported configuration option
1734 ** is invoked.
1735 **
1736 ** <dl>
1737 ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
1738 ** <dd> ^This option takes three additional arguments that determine the
1739 ** [lookaside memory allocator] configuration for the [database connection].
1740 ** ^The first argument (the third parameter to [sqlite3_db_config()] is a
1741 ** pointer to a memory buffer to use for lookaside memory.
1742 ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb
1743 ** may be NULL in which case SQLite will allocate the
1744 ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the
1745 ** size of each lookaside buffer slot. ^The third argument is the number of
1746 ** slots. The size of the buffer in the first argument must be greater than
1747 ** or equal to the product of the second and third arguments. The buffer
1748 ** must be aligned to an 8-byte boundary. ^If the second argument to
1749 ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally
1750 ** rounded down to the next smaller multiple of 8. ^(The lookaside memory
1751 ** configuration for a database connection can only be changed when that
1752 ** connection is not currently using lookaside memory, or in other words
1753 ** when the "current value" returned by
1754 ** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero.
1755 ** Any attempt to change the lookaside memory configuration when lookaside
1756 ** memory is in use leaves the configuration unchanged and returns
1757 ** [SQLITE_BUSY].)^</dd>
1758 **
1759 ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt>
1760 ** <dd> ^This option is used to enable or disable the enforcement of
1761 ** [foreign key constraints]. There should be two additional arguments.
1762 ** The first argument is an integer which is 0 to disable FK enforcement,
1763 ** positive to enable FK enforcement or negative to leave FK enforcement
1764 ** unchanged. The second parameter is a pointer to an integer into which
1765 ** is written 0 or 1 to indicate whether FK enforcement is off or on
1766 ** following this call. The second parameter may be a NULL pointer, in
1767 ** which case the FK enforcement setting is not reported back. </dd>
1768 **
1769 ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt>
1770 ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].
1771 ** There should be two additional arguments.
1772 ** The first argument is an integer which is 0 to disable triggers,
1773 ** positive to enable triggers or negative to leave the setting unchanged.
1774 ** The second parameter is a pointer to an integer into which
1775 ** is written 0 or 1 to indicate whether triggers are disabled or enabled
1776 ** following this call. The second parameter may be a NULL pointer, in
1777 ** which case the trigger setting is not reported back. </dd>
1778 **
1779 ** </dl>
1780 */
1781 #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */
1782 #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */
1783 #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */
1784 
1785 
1786 /*
1787 ** CAPI3REF: Enable Or Disable Extended Result Codes
1788 **
1789 ** ^The sqlite3_extended_result_codes() routine enables or disables the
1790 ** [extended result codes] feature of SQLite. ^The extended result
1791 ** codes are disabled by default for historical compatibility.
1792 */
1794 
1795 /*
1796 ** CAPI3REF: Last Insert Rowid
1797 **
1798 ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables)
1799 ** has a unique 64-bit signed
1800 ** integer key called the [ROWID | "rowid"]. ^The rowid is always available
1801 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
1802 ** names are not also used by explicitly declared columns. ^If
1803 ** the table has a column of type [INTEGER PRIMARY KEY] then that column
1804 ** is another alias for the rowid.
1805 **
1806 ** ^The sqlite3_last_insert_rowid(D) interface returns the [rowid] of the
1807 ** most recent successful [INSERT] into a rowid table or [virtual table]
1808 ** on database connection D.
1809 ** ^Inserts into [WITHOUT ROWID] tables are not recorded.
1810 ** ^If no successful [INSERT]s into rowid tables
1811 ** have ever occurred on the database connection D,
1812 ** then sqlite3_last_insert_rowid(D) returns zero.
1813 **
1814 ** ^(If an [INSERT] occurs within a trigger or within a [virtual table]
1815 ** method, then this routine will return the [rowid] of the inserted
1816 ** row as long as the trigger or virtual table method is running.
1817 ** But once the trigger or virtual table method ends, the value returned
1818 ** by this routine reverts to what it was before the trigger or virtual
1819 ** table method began.)^
1820 **
1821 ** ^An [INSERT] that fails due to a constraint violation is not a
1822 ** successful [INSERT] and does not change the value returned by this
1823 ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
1824 ** and INSERT OR ABORT make no changes to the return value of this
1825 ** routine when their insertion fails. ^(When INSERT OR REPLACE
1826 ** encounters a constraint violation, it does not fail. The
1827 ** INSERT continues to completion after deleting rows that caused
1828 ** the constraint problem so INSERT OR REPLACE will always change
1829 ** the return value of this interface.)^
1830 **
1831 ** ^For the purposes of this routine, an [INSERT] is considered to
1832 ** be successful even if it is subsequently rolled back.
1833 **
1834 ** This function is accessible to SQL statements via the
1835 ** [last_insert_rowid() SQL function].
1836 **
1837 ** If a separate thread performs a new [INSERT] on the same
1838 ** database connection while the [sqlite3_last_insert_rowid()]
1839 ** function is running and thus changes the last insert [rowid],
1840 ** then the value returned by [sqlite3_last_insert_rowid()] is
1841 ** unpredictable and might not equal either the old or the new
1842 ** last insert [rowid].
1843 */
1845 
1846 /*
1847 ** CAPI3REF: Count The Number Of Rows Modified
1848 **
1849 ** ^This function returns the number of database rows that were changed
1850 ** or inserted or deleted by the most recently completed SQL statement
1851 ** on the [database connection] specified by the first parameter.
1852 ** ^(Only changes that are directly specified by the [INSERT], [UPDATE],
1853 ** or [DELETE] statement are counted. Auxiliary changes caused by
1854 ** triggers or [foreign key actions] are not counted.)^ Use the
1855 ** [sqlite3_total_changes()] function to find the total number of changes
1856 ** including changes caused by triggers and foreign key actions.
1857 **
1858 ** ^Changes to a view that are simulated by an [INSTEAD OF trigger]
1859 ** are not counted. Only real table changes are counted.
1860 **
1861 ** ^(A "row change" is a change to a single row of a single table
1862 ** caused by an INSERT, DELETE, or UPDATE statement. Rows that
1863 ** are changed as side effects of [REPLACE] constraint resolution,
1864 ** rollback, ABORT processing, [DROP TABLE], or by any other
1865 ** mechanisms do not count as direct row changes.)^
1866 **
1867 ** A "trigger context" is a scope of execution that begins and
1868 ** ends with the script of a [CREATE TRIGGER | trigger].
1869 ** Most SQL statements are
1870 ** evaluated outside of any trigger. This is the "top level"
1871 ** trigger context. If a trigger fires from the top level, a
1872 ** new trigger context is entered for the duration of that one
1873 ** trigger. Subtriggers create subcontexts for their duration.
1874 **
1875 ** ^Calling [sqlite3_exec()] or [sqlite3_step()] recursively does
1876 ** not create a new trigger context.
1877 **
1878 ** ^This function returns the number of direct row changes in the
1879 ** most recent INSERT, UPDATE, or DELETE statement within the same
1880 ** trigger context.
1881 **
1882 ** ^Thus, when called from the top level, this function returns the
1883 ** number of changes in the most recent INSERT, UPDATE, or DELETE
1884 ** that also occurred at the top level. ^(Within the body of a trigger,
1885 ** the sqlite3_changes() interface can be called to find the number of
1886 ** changes in the most recently completed INSERT, UPDATE, or DELETE
1887 ** statement within the body of the same trigger.
1888 ** However, the number returned does not include changes
1889 ** caused by subtriggers since those have their own context.)^
1890 **
1891 ** See also the [sqlite3_total_changes()] interface, the
1892 ** [count_changes pragma], and the [changes() SQL function].
1893 **
1894 ** If a separate thread makes changes on the same database connection
1895 ** while [sqlite3_changes()] is running then the value returned
1896 ** is unpredictable and not meaningful.
1897 */
1899 
1900 /*
1901 ** CAPI3REF: Total Number Of Rows Modified
1902 **
1903 ** ^This function returns the number of row changes caused by [INSERT],
1904 ** [UPDATE] or [DELETE] statements since the [database connection] was opened.
1905 ** ^(The count returned by sqlite3_total_changes() includes all changes
1906 ** from all [CREATE TRIGGER | trigger] contexts and changes made by
1907 ** [foreign key actions]. However,
1908 ** the count does not include changes used to implement [REPLACE] constraints,
1909 ** do rollbacks or ABORT processing, or [DROP TABLE] processing. The
1910 ** count does not include rows of views that fire an [INSTEAD OF trigger],
1911 ** though if the INSTEAD OF trigger makes changes of its own, those changes
1912 ** are counted.)^
1913 ** ^The sqlite3_total_changes() function counts the changes as soon as
1914 ** the statement that makes them is completed (when the statement handle
1915 ** is passed to [sqlite3_reset()] or [sqlite3_finalize()]).
1916 **
1917 ** See also the [sqlite3_changes()] interface, the
1918 ** [count_changes pragma], and the [total_changes() SQL function].
1919 **
1920 ** If a separate thread makes changes on the same database connection
1921 ** while [sqlite3_total_changes()] is running then the value
1922 ** returned is unpredictable and not meaningful.
1923 */
1925 
1926 /*
1927 ** CAPI3REF: Interrupt A Long-Running Query
1928 **
1929 ** ^This function causes any pending database operation to abort and
1930 ** return at its earliest opportunity. This routine is typically
1931 ** called in response to a user action such as pressing "Cancel"
1932 ** or Ctrl-C where the user wants a long query operation to halt
1933 ** immediately.
1934 **
1935 ** ^It is safe to call this routine from a thread different from the
1936 ** thread that is currently running the database operation. But it
1937 ** is not safe to call this routine with a [database connection] that
1938 ** is closed or might close before sqlite3_interrupt() returns.
1939 **
1940 ** ^If an SQL operation is very nearly finished at the time when
1941 ** sqlite3_interrupt() is called, then it might not have an opportunity
1942 ** to be interrupted and might continue to completion.
1943 **
1944 ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
1945 ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
1946 ** that is inside an explicit transaction, then the entire transaction
1947 ** will be rolled back automatically.
1948 **
1949 ** ^The sqlite3_interrupt(D) call is in effect until all currently running
1950 ** SQL statements on [database connection] D complete. ^Any new SQL statements
1951 ** that are started after the sqlite3_interrupt() call and before the
1952 ** running statements reaches zero are interrupted as if they had been
1953 ** running prior to the sqlite3_interrupt() call. ^New SQL statements
1954 ** that are started after the running statement count reaches zero are
1955 ** not effected by the sqlite3_interrupt().
1956 ** ^A call to sqlite3_interrupt(D) that occurs when there are no running
1957 ** SQL statements is a no-op and has no effect on SQL statements
1958 ** that are started after the sqlite3_interrupt() call returns.
1959 **
1960 ** If the database connection closes while [sqlite3_interrupt()]
1961 ** is running then bad things will likely happen.
1962 */
1964 
1965 /*
1966 ** CAPI3REF: Determine If An SQL Statement Is Complete
1967 **
1968 ** These routines are useful during command-line input to determine if the
1969 ** currently entered text seems to form a complete SQL statement or
1970 ** if additional input is needed before sending the text into
1971 ** SQLite for parsing. ^These routines return 1 if the input string
1972 ** appears to be a complete SQL statement. ^A statement is judged to be
1973 ** complete if it ends with a semicolon token and is not a prefix of a
1974 ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within
1975 ** string literals or quoted identifier names or comments are not
1976 ** independent tokens (they are part of the token in which they are
1977 ** embedded) and thus do not count as a statement terminator. ^Whitespace
1978 ** and comments that follow the final semicolon are ignored.
1979 **
1980 ** ^These routines return 0 if the statement is incomplete. ^If a
1981 ** memory allocation fails, then SQLITE_NOMEM is returned.
1982 **
1983 ** ^These routines do not parse the SQL statements thus
1984 ** will not detect syntactically incorrect SQL.
1985 **
1986 ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior
1987 ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
1988 ** automatically by sqlite3_complete16(). If that initialization fails,
1989 ** then the return value from sqlite3_complete16() will be non-zero
1990 ** regardless of whether or not the input SQL is complete.)^
1991 **
1992 ** The input to [sqlite3_complete()] must be a zero-terminated
1993 ** UTF-8 string.
1994 **
1995 ** The input to [sqlite3_complete16()] must be a zero-terminated
1996 ** UTF-16 string in native byte order.
1997 */
1998 SQLITE_API int sqlite3_complete(const char *sql);
1999 SQLITE_API int sqlite3_complete16(const void *sql);
2000 
2001 /*
2002 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
2003 **
2004 ** ^This routine sets a callback function that might be invoked whenever
2005 ** an attempt is made to open a database table that another thread
2006 ** or process has locked.
2007 **
2008 ** ^If the busy callback is NULL, then [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]
2009 ** is returned immediately upon encountering the lock. ^If the busy callback
2010 ** is not NULL, then the callback might be invoked with two arguments.
2011 **
2012 ** ^The first argument to the busy handler is a copy of the void* pointer which
2013 ** is the third argument to sqlite3_busy_handler(). ^The second argument to
2014 ** the busy handler callback is the number of times that the busy handler has
2015 ** been invoked for this locking event. ^If the
2016 ** busy callback returns 0, then no additional attempts are made to
2017 ** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned.
2018 ** ^If the callback returns non-zero, then another attempt
2019 ** is made to open the database for reading and the cycle repeats.
2020 **
2021 ** The presence of a busy handler does not guarantee that it will be invoked
2022 ** when there is lock contention. ^If SQLite determines that invoking the busy
2023 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
2024 ** or [SQLITE_IOERR_BLOCKED] instead of invoking the busy handler.
2025 ** Consider a scenario where one process is holding a read lock that
2026 ** it is trying to promote to a reserved lock and
2027 ** a second process is holding a reserved lock that it is trying
2028 ** to promote to an exclusive lock. The first process cannot proceed
2029 ** because it is blocked by the second and the second process cannot
2030 ** proceed because it is blocked by the first. If both processes
2031 ** invoke the busy handlers, neither will make any progress. Therefore,
2032 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
2033 ** will induce the first process to release its read lock and allow
2034 ** the second process to proceed.
2035 **
2036 ** ^The default busy callback is NULL.
2037 **
2038 ** ^The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED]
2039 ** when SQLite is in the middle of a large transaction where all the
2040 ** changes will not fit into the in-memory cache. SQLite will
2041 ** already hold a RESERVED lock on the database file, but it needs
2042 ** to promote this lock to EXCLUSIVE so that it can spill cache
2043 ** pages into the database file without harm to concurrent
2044 ** readers. ^If it is unable to promote the lock, then the in-memory
2045 ** cache will be left in an inconsistent state and so the error
2046 ** code is promoted from the relatively benign [SQLITE_BUSY] to
2047 ** the more severe [SQLITE_IOERR_BLOCKED]. ^This error code promotion
2048 ** forces an automatic rollback of the changes. See the
2049 ** <a href="/cvstrac/wiki?p=CorruptionFollowingBusyError">
2050 ** CorruptionFollowingBusyError</a> wiki page for a discussion of why
2051 ** this is important.
2052 **
2053 ** ^(There can only be a single busy handler defined for each
2054 ** [database connection]. Setting a new busy handler clears any
2055 ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()]
2056 ** will also set or clear the busy handler.
2057 **
2058 ** The busy callback should not take any actions which modify the
2059 ** database connection that invoked the busy handler. Any such actions
2060 ** result in undefined behavior.
2061 **
2062 ** A busy handler must not close the database connection
2063 ** or [prepared statement] that invoked the busy handler.
2064 */
2065 SQLITE_API int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*);
2066 
2067 /*
2068 ** CAPI3REF: Set A Busy Timeout
2069 **
2070 ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
2071 ** for a specified amount of time when a table is locked. ^The handler
2072 ** will sleep multiple times until at least "ms" milliseconds of sleeping
2073 ** have accumulated. ^After at least "ms" milliseconds of sleeping,
2074 ** the handler returns 0 which causes [sqlite3_step()] to return
2075 ** [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED].
2076 **
2077 ** ^Calling this routine with an argument less than or equal to zero
2078 ** turns off all busy handlers.
2079 **
2080 ** ^(There can only be a single busy handler for a particular
2081 ** [database connection] any any given moment. If another busy handler
2082 ** was defined (using [sqlite3_busy_handler()]) prior to calling
2083 ** this routine, that other busy handler is cleared.)^
2084 */
2086 
2087 /*
2088 ** CAPI3REF: Convenience Routines For Running Queries
2089 **
2090 ** This is a legacy interface that is preserved for backwards compatibility.
2091 ** Use of this interface is not recommended.
2092 **
2093 ** Definition: A <b>result table</b> is memory data structure created by the
2094 ** [sqlite3_get_table()] interface. A result table records the
2095 ** complete query results from one or more queries.
2096 **
2097 ** The table conceptually has a number of rows and columns. But
2098 ** these numbers are not part of the result table itself. These
2099 ** numbers are obtained separately. Let N be the number of rows
2100 ** and M be the number of columns.
2101 **
2102 ** A result table is an array of pointers to zero-terminated UTF-8 strings.
2103 ** There are (N+1)*M elements in the array. The first M pointers point
2104 ** to zero-terminated strings that contain the names of the columns.
2105 ** The remaining entries all point to query results. NULL values result
2106 ** in NULL pointers. All other values are in their UTF-8 zero-terminated
2107 ** string representation as returned by [sqlite3_column_text()].
2108 **
2109 ** A result table might consist of one or more memory allocations.
2110 ** It is not safe to pass a result table directly to [sqlite3_free()].
2111 ** A result table should be deallocated using [sqlite3_free_table()].
2112 **
2113 ** ^(As an example of the result table format, suppose a query result
2114 ** is as follows:
2115 **
2116 ** <blockquote><pre>
2117 ** Name | Age
2118 ** -----------------------
2119 ** Alice | 43
2120 ** Bob | 28
2121 ** Cindy | 21
2122 ** </pre></blockquote>
2123 **
2124 ** There are two column (M==2) and three rows (N==3). Thus the
2125 ** result table has 8 entries. Suppose the result table is stored
2126 ** in an array names azResult. Then azResult holds this content:
2127 **
2128 ** <blockquote><pre>
2129 ** azResult&#91;0] = "Name";
2130 ** azResult&#91;1] = "Age";
2131 ** azResult&#91;2] = "Alice";
2132 ** azResult&#91;3] = "43";
2133 ** azResult&#91;4] = "Bob";
2134 ** azResult&#91;5] = "28";
2135 ** azResult&#91;6] = "Cindy";
2136 ** azResult&#91;7] = "21";
2137 ** </pre></blockquote>)^
2138 **
2139 ** ^The sqlite3_get_table() function evaluates one or more
2140 ** semicolon-separated SQL statements in the zero-terminated UTF-8
2141 ** string of its 2nd parameter and returns a result table to the
2142 ** pointer given in its 3rd parameter.
2143 **
2144 ** After the application has finished with the result from sqlite3_get_table(),
2145 ** it must pass the result table pointer to sqlite3_free_table() in order to
2146 ** release the memory that was malloced. Because of the way the
2147 ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
2148 ** function must not try to call [sqlite3_free()] directly. Only
2149 ** [sqlite3_free_table()] is able to release the memory properly and safely.
2150 **
2151 ** The sqlite3_get_table() interface is implemented as a wrapper around
2152 ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access
2153 ** to any internal data structures of SQLite. It uses only the public
2154 ** interface defined here. As a consequence, errors that occur in the
2155 ** wrapper layer outside of the internal [sqlite3_exec()] call are not
2156 ** reflected in subsequent calls to [sqlite3_errcode()] or
2157 ** [sqlite3_errmsg()].
2158 */
2160  sqlite3 *db, /* An open database */
2161  const char *zSql, /* SQL to be evaluated */
2162  char ***pazResult, /* Results of the query */
2163  int *pnRow, /* Number of result rows written here */
2164  int *pnColumn, /* Number of result columns written here */
2165  char **pzErrmsg /* Error msg written here */
2166 );
2167 SQLITE_API void sqlite3_free_table(char **result);
2168 
2169 /*
2170 ** CAPI3REF: Formatted String Printing Functions
2171 **
2172 ** These routines are work-alikes of the "printf()" family of functions
2173 ** from the standard C library.
2174 **
2175 ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
2176 ** results into memory obtained from [sqlite3_malloc()].
2177 ** The strings returned by these two routines should be
2178 ** released by [sqlite3_free()]. ^Both routines return a
2179 ** NULL pointer if [sqlite3_malloc()] is unable to allocate enough
2180 ** memory to hold the resulting string.
2181 **
2182 ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
2183 ** the standard C library. The result is written into the
2184 ** buffer supplied as the second parameter whose size is given by
2185 ** the first parameter. Note that the order of the
2186 ** first two parameters is reversed from snprintf().)^ This is an
2187 ** historical accident that cannot be fixed without breaking
2188 ** backwards compatibility. ^(Note also that sqlite3_snprintf()
2189 ** returns a pointer to its buffer instead of the number of
2190 ** characters actually written into the buffer.)^ We admit that
2191 ** the number of characters written would be a more useful return
2192 ** value but we cannot change the implementation of sqlite3_snprintf()
2193 ** now without breaking compatibility.
2194 **
2195 ** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
2196 ** guarantees that the buffer is always zero-terminated. ^The first
2197 ** parameter "n" is the total size of the buffer, including space for
2198 ** the zero terminator. So the longest string that can be completely
2199 ** written will be n-1 characters.
2200 **
2201 ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
2202 **
2203 ** These routines all implement some additional formatting
2204 ** options that are useful for constructing SQL statements.
2205 ** All of the usual printf() formatting options apply. In addition, there
2206 ** is are "%q", "%Q", and "%z" options.
2207 **
2208 ** ^(The %q option works like %s in that it substitutes a nul-terminated
2209 ** string from the argument list. But %q also doubles every '\'' character.
2210 ** %q is designed for use inside a string literal.)^ By doubling each '\''
2211 ** character it escapes that character and allows it to be inserted into
2212 ** the string.
2213 **
2214 ** For example, assume the string variable zText contains text as follows:
2215 **
2216 ** <blockquote><pre>
2217 ** char *zText = "It's a happy day!";
2218 ** </pre></blockquote>
2219 **
2220 ** One can use this text in an SQL statement as follows:
2221 **
2222 ** <blockquote><pre>
2223 ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText);
2224 ** sqlite3_exec(db, zSQL, 0, 0, 0);
2225 ** sqlite3_free(zSQL);
2226 ** </pre></blockquote>
2227 **
2228 ** Because the %q format string is used, the '\'' character in zText
2229 ** is escaped and the SQL generated is as follows:
2230 **
2231 ** <blockquote><pre>
2232 ** INSERT INTO table1 VALUES('It''s a happy day!')
2233 ** </pre></blockquote>
2234 **
2235 ** This is correct. Had we used %s instead of %q, the generated SQL
2236 ** would have looked like this:
2237 **
2238 ** <blockquote><pre>
2239 ** INSERT INTO table1 VALUES('It's a happy day!');
2240 ** </pre></blockquote>
2241 **
2242 ** This second example is an SQL syntax error. As a general rule you should
2243 ** always use %q instead of %s when inserting text into a string literal.
2244 **
2245 ** ^(The %Q option works like %q except it also adds single quotes around
2246 ** the outside of the total string. Additionally, if the parameter in the
2247 ** argument list is a NULL pointer, %Q substitutes the text "NULL" (without
2248 ** single quotes).)^ So, for example, one could say:
2249 **
2250 ** <blockquote><pre>
2251 ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText);
2252 ** sqlite3_exec(db, zSQL, 0, 0, 0);
2253 ** sqlite3_free(zSQL);
2254 ** </pre></blockquote>
2255 **
2256 ** The code above will render a correct SQL statement in the zSQL
2257 ** variable even if the zText variable is a NULL pointer.
2258 **
2259 ** ^(The "%z" formatting option works like "%s" but with the
2260 ** addition that after the string has been read and copied into
2261 ** the result, [sqlite3_free()] is called on the input string.)^
2262 */
2263 SQLITE_API char *sqlite3_mprintf(const char*,...);
2264 SQLITE_API char *sqlite3_vmprintf(const char*, va_list);
2265 SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...);
2266 SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list);
2267 
2268 /*
2269 ** CAPI3REF: Memory Allocation Subsystem
2270 **
2271 ** The SQLite core uses these three routines for all of its own
2272 ** internal memory allocation needs. "Core" in the previous sentence
2273 ** does not include operating-system specific VFS implementation. The
2274 ** Windows VFS uses native malloc() and free() for some operations.
2275 **
2276 ** ^The sqlite3_malloc() routine returns a pointer to a block
2277 ** of memory at least N bytes in length, where N is the parameter.
2278 ** ^If sqlite3_malloc() is unable to obtain sufficient free
2279 ** memory, it returns a NULL pointer. ^If the parameter N to
2280 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
2281 ** a NULL pointer.
2282 **
2283 ** ^Calling sqlite3_free() with a pointer previously returned
2284 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
2285 ** that it might be reused. ^The sqlite3_free() routine is
2286 ** a no-op if is called with a NULL pointer. Passing a NULL pointer
2287 ** to sqlite3_free() is harmless. After being freed, memory
2288 ** should neither be read nor written. Even reading previously freed
2289 ** memory might result in a segmentation fault or other severe error.
2290 ** Memory corruption, a segmentation fault, or other severe error
2291 ** might result if sqlite3_free() is called with a non-NULL pointer that
2292 ** was not obtained from sqlite3_malloc() or sqlite3_realloc().
2293 **
2294 ** ^(The sqlite3_realloc() interface attempts to resize a
2295 ** prior memory allocation to be at least N bytes, where N is the
2296 ** second parameter. The memory allocation to be resized is the first
2297 ** parameter.)^ ^ If the first parameter to sqlite3_realloc()
2298 ** is a NULL pointer then its behavior is identical to calling
2299 ** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc().
2300 ** ^If the second parameter to sqlite3_realloc() is zero or
2301 ** negative then the behavior is exactly the same as calling
2302 ** sqlite3_free(P) where P is the first parameter to sqlite3_realloc().
2303 ** ^sqlite3_realloc() returns a pointer to a memory allocation
2304 ** of at least N bytes in size or NULL if sufficient memory is unavailable.
2305 ** ^If M is the size of the prior allocation, then min(N,M) bytes
2306 ** of the prior allocation are copied into the beginning of buffer returned
2307 ** by sqlite3_realloc() and the prior allocation is freed.
2308 ** ^If sqlite3_realloc() returns NULL, then the prior allocation
2309 ** is not freed.
2310 **
2311 ** ^The memory returned by sqlite3_malloc() and sqlite3_realloc()
2312 ** is always aligned to at least an 8 byte boundary, or to a
2313 ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
2314 ** option is used.
2315 **
2316 ** In SQLite version 3.5.0 and 3.5.1, it was possible to define
2317 ** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in
2318 ** implementation of these routines to be omitted. That capability
2319 ** is no longer provided. Only built-in memory allocators can be used.
2320 **
2321 ** Prior to SQLite version 3.7.10, the Windows OS interface layer called
2322 ** the system malloc() and free() directly when converting
2323 ** filenames between the UTF-8 encoding used by SQLite
2324 ** and whatever filename encoding is used by the particular Windows
2325 ** installation. Memory allocation errors were detected, but
2326 ** they were reported back as [SQLITE_CANTOPEN] or
2327 ** [SQLITE_IOERR] rather than [SQLITE_NOMEM].
2328 **
2329 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
2330 ** must be either NULL or else pointers obtained from a prior
2331 ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
2332 ** not yet been released.
2333 **
2334 ** The application must not read or write any part of
2335 ** a block of memory after it has been released using
2336 ** [sqlite3_free()] or [sqlite3_realloc()].
2337 */
2338 SQLITE_API void *sqlite3_malloc(int);
2339 SQLITE_API void *sqlite3_realloc(void*, int);
2340 SQLITE_API void sqlite3_free(void*);
2341 
2342 /*
2343 ** CAPI3REF: Memory Allocator Statistics
2344 **
2345 ** SQLite provides these two interfaces for reporting on the status
2346 ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
2347 ** routines, which form the built-in memory allocation subsystem.
2348 **
2349 ** ^The [sqlite3_memory_used()] routine returns the number of bytes
2350 ** of memory currently outstanding (malloced but not freed).
2351 ** ^The [sqlite3_memory_highwater()] routine returns the maximum
2352 ** value of [sqlite3_memory_used()] since the high-water mark
2353 ** was last reset. ^The values returned by [sqlite3_memory_used()] and
2354 ** [sqlite3_memory_highwater()] include any overhead
2355 ** added by SQLite in its implementation of [sqlite3_malloc()],
2356 ** but not overhead added by the any underlying system library
2357 ** routines that [sqlite3_malloc()] may call.
2358 **
2359 ** ^The memory high-water mark is reset to the current value of
2360 ** [sqlite3_memory_used()] if and only if the parameter to
2361 ** [sqlite3_memory_highwater()] is true. ^The value returned
2362 ** by [sqlite3_memory_highwater(1)] is the high-water mark
2363 ** prior to the reset.
2364 */
2365 SQLITE_API sqlite3_int64 sqlite3_memory_used(void);
2366 SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag);
2367 
2368 /*
2369 ** CAPI3REF: Pseudo-Random Number Generator
2370 **
2371 ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
2372 ** select random [ROWID | ROWIDs] when inserting new records into a table that
2373 ** already uses the largest possible [ROWID]. The PRNG is also used for
2374 ** the build-in random() and randomblob() SQL functions. This interface allows
2375 ** applications to access the same PRNG for other purposes.
2376 **
2377 ** ^A call to this routine stores N bytes of randomness into buffer P.
2378 **
2379 ** ^The first time this routine is invoked (either internally or by
2380 ** the application) the PRNG is seeded using randomness obtained
2381 ** from the xRandomness method of the default [sqlite3_vfs] object.
2382 ** ^On all subsequent invocations, the pseudo-randomness is generated
2383 ** internally and without recourse to the [sqlite3_vfs] xRandomness
2384 ** method.
2385 */
2386 SQLITE_API void sqlite3_randomness(int N, void *P);
2387 
2388 /*
2389 ** CAPI3REF: Compile-Time Authorization Callbacks
2390 **
2391 ** ^This routine registers an authorizer callback with a particular
2392 ** [database connection], supplied in the first argument.
2393 ** ^The authorizer callback is invoked as SQL statements are being compiled
2394 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
2395 ** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various
2396 ** points during the compilation process, as logic is being created
2397 ** to perform various actions, the authorizer callback is invoked to
2398 ** see if those actions are allowed. ^The authorizer callback should
2399 ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
2400 ** specific action but allow the SQL statement to continue to be
2401 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
2402 ** rejected with an error. ^If the authorizer callback returns
2403 ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
2404 ** then the [sqlite3_prepare_v2()] or equivalent call that triggered
2405 ** the authorizer will fail with an error message.
2406 **
2407 ** When the callback returns [SQLITE_OK], that means the operation
2408 ** requested is ok. ^When the callback returns [SQLITE_DENY], the
2409 ** [sqlite3_prepare_v2()] or equivalent call that triggered the
2410 ** authorizer will fail with an error message explaining that
2411 ** access is denied.
2412 **
2413 ** ^The first parameter to the authorizer callback is a copy of the third
2414 ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
2415 ** to the callback is an integer [SQLITE_COPY | action code] that specifies
2416 ** the particular action to be authorized. ^The third through sixth parameters
2417 ** to the callback are zero-terminated strings that contain additional
2418 ** details about the action to be authorized.
2419 **
2420 ** ^If the action code is [SQLITE_READ]
2421 ** and the callback returns [SQLITE_IGNORE] then the
2422 ** [prepared statement] statement is constructed to substitute
2423 ** a NULL value in place of the table column that would have
2424 ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE]
2425 ** return can be used to deny an untrusted user access to individual
2426 ** columns of a table.
2427 ** ^If the action code is [SQLITE_DELETE] and the callback returns
2428 ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
2429 ** [truncate optimization] is disabled and all rows are deleted individually.
2430 **
2431 ** An authorizer is used when [sqlite3_prepare | preparing]
2432 ** SQL statements from an untrusted source, to ensure that the SQL statements
2433 ** do not try to access data they are not allowed to see, or that they do not
2434 ** try to execute malicious statements that damage the database. For
2435 ** example, an application may allow a user to enter arbitrary
2436 ** SQL queries for evaluation by a database. But the application does
2437 ** not want the user to be able to make arbitrary changes to the
2438 ** database. An authorizer could then be put in place while the
2439 ** user-entered SQL is being [sqlite3_prepare | prepared] that
2440 ** disallows everything except [SELECT] statements.
2441 **
2442 ** Applications that need to process SQL from untrusted sources
2443 ** might also consider lowering resource limits using [sqlite3_limit()]
2444 ** and limiting database size using the [max_page_count] [PRAGMA]
2445 ** in addition to using an authorizer.
2446 **
2447 ** ^(Only a single authorizer can be in place on a database connection
2448 ** at a time. Each call to sqlite3_set_authorizer overrides the
2449 ** previous call.)^ ^Disable the authorizer by installing a NULL callback.
2450 ** The authorizer is disabled by default.
2451 **
2452 ** The authorizer callback must not do anything that will modify
2453 ** the database connection that invoked the authorizer callback.
2454 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
2455 ** database connections for the meaning of "modify" in this paragraph.
2456 **
2457 ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
2458 ** statement might be re-prepared during [sqlite3_step()] due to a
2459 ** schema change. Hence, the application should ensure that the
2460 ** correct authorizer callback remains in place during the [sqlite3_step()].
2461 **
2462 ** ^Note that the authorizer callback is invoked only during
2463 ** [sqlite3_prepare()] or its variants. Authorization is not
2464 ** performed during statement evaluation in [sqlite3_step()], unless
2465 ** as stated in the previous paragraph, sqlite3_step() invokes
2466 ** sqlite3_prepare_v2() to reprepare a statement after a schema change.
2467 */
2469  sqlite3*,
2470  int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
2471  void *pUserData
2472 );
2473 
2474 /*
2475 ** CAPI3REF: Authorizer Return Codes
2476 **
2477 ** The [sqlite3_set_authorizer | authorizer callback function] must
2478 ** return either [SQLITE_OK] or one of these two constants in order
2479 ** to signal SQLite whether or not the action is permitted. See the
2480 ** [sqlite3_set_authorizer | authorizer documentation] for additional
2481 ** information.
2482 **
2483 ** Note that SQLITE_IGNORE is also used as a [SQLITE_ROLLBACK | return code]
2484 ** from the [sqlite3_vtab_on_conflict()] interface.
2485 */
2486 #define SQLITE_DENY 1 /* Abort the SQL statement with an error */
2487 #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */
2488 
2489 /*
2490 ** CAPI3REF: Authorizer Action Codes
2491 **
2492 ** The [sqlite3_set_authorizer()] interface registers a callback function
2493 ** that is invoked to authorize certain SQL statement actions. The
2494 ** second parameter to the callback is an integer code that specifies
2495 ** what action is being authorized. These are the integer action codes that
2496 ** the authorizer callback may be passed.
2497 **
2498 ** These action code values signify what kind of operation is to be
2499 ** authorized. The 3rd and 4th parameters to the authorization
2500 ** callback function will be parameters or NULL depending on which of these
2501 ** codes is used as the second parameter. ^(The 5th parameter to the
2502 ** authorizer callback is the name of the database ("main", "temp",
2503 ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback
2504 ** is the name of the inner-most trigger or view that is responsible for
2505 ** the access attempt or NULL if this access attempt is directly from
2506 ** top-level SQL code.
2507 */
2508 /******************************************* 3rd ************ 4th ***********/
2509 #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */
2510 #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */
2511 #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */
2512 #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */
2513 #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */
2514 #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */
2515 #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */
2516 #define SQLITE_CREATE_VIEW 8 /* View Name NULL */
2517 #define SQLITE_DELETE 9 /* Table Name NULL */
2518 #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */
2519 #define SQLITE_DROP_TABLE 11 /* Table Name NULL */
2520 #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */
2521 #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */
2522 #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */
2523 #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */
2524 #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */
2525 #define SQLITE_DROP_VIEW 17 /* View Name NULL */
2526 #define SQLITE_INSERT 18 /* Table Name NULL */
2527 #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */
2528 #define SQLITE_READ 20 /* Table Name Column Name */
2529 #define SQLITE_SELECT 21 /* NULL NULL */
2530 #define SQLITE_TRANSACTION 22 /* Operation NULL */
2531 #define SQLITE_UPDATE 23 /* Table Name Column Name */
2532 #define SQLITE_ATTACH 24 /* Filename NULL */
2533 #define SQLITE_DETACH 25 /* Database Name NULL */
2534 #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */
2535 #define SQLITE_REINDEX 27 /* Index Name NULL */
2536 #define SQLITE_ANALYZE 28 /* Table Name NULL */
2537 #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */
2538 #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */
2539 #define SQLITE_FUNCTION 31 /* NULL Function Name */
2540 #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */
2541 #define SQLITE_COPY 0 /* No longer used */
2542 
2543 /*
2544 ** CAPI3REF: Tracing And Profiling Functions
2545 **
2546 ** These routines register callback functions that can be used for
2547 ** tracing and profiling the execution of SQL statements.
2548 **
2549 ** ^The callback function registered by sqlite3_trace() is invoked at
2550 ** various times when an SQL statement is being run by [sqlite3_step()].
2551 ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
2552 ** SQL statement text as the statement first begins executing.
2553 ** ^(Additional sqlite3_trace() callbacks might occur
2554 ** as each triggered subprogram is entered. The callbacks for triggers
2555 ** contain a UTF-8 SQL comment that identifies the trigger.)^
2556 **
2557 ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit
2558 ** the length of [bound parameter] expansion in the output of sqlite3_trace().
2559 **
2560 ** ^The callback function registered by sqlite3_profile() is invoked
2561 ** as each SQL statement finishes. ^The profile callback contains
2562 ** the original statement text and an estimate of wall-clock time
2563 ** of how long that statement took to run. ^The profile callback
2564 ** time is in units of nanoseconds, however the current implementation
2565 ** is only capable of millisecond resolution so the six least significant
2566 ** digits in the time are meaningless. Future versions of SQLite
2567 ** might provide greater resolution on the profiler callback. The
2568 ** sqlite3_profile() function is considered experimental and is
2569 ** subject to change in future versions of SQLite.
2570 */
2571 SQLITE_API void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*);
2573  void(*xProfile)(void*,const char*,sqlite3_uint64), void*);
2574 
2575 /*
2576 ** CAPI3REF: Query Progress Callbacks
2577 **
2578 ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
2579 ** function X to be invoked periodically during long running calls to
2580 ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for
2581 ** database connection D. An example use for this
2582 ** interface is to keep a GUI updated during a large query.
2583 **
2584 ** ^The parameter P is passed through as the only parameter to the
2585 ** callback function X. ^The parameter N is the approximate number of
2586 ** [virtual machine instructions] that are evaluated between successive
2587 ** invocations of the callback X. ^If N is less than one then the progress
2588 ** handler is disabled.
2589 **
2590 ** ^Only a single progress handler may be defined at one time per
2591 ** [database connection]; setting a new progress handler cancels the
2592 ** old one. ^Setting parameter X to NULL disables the progress handler.
2593 ** ^The progress handler is also disabled by setting N to a value less
2594 ** than 1.
2595 **
2596 ** ^If the progress callback returns non-zero, the operation is
2597 ** interrupted. This feature can be used to implement a
2598 ** "Cancel" button on a GUI progress dialog box.
2599 **
2600 ** The progress handler callback must not do anything that will modify
2601 ** the database connection that invoked the progress handler.
2602 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
2603 ** database connections for the meaning of "modify" in this paragraph.
2604 **
2605 */
2606 SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
2607 
2608 /*
2609 ** CAPI3REF: Opening A New Database Connection
2610 **
2611 ** ^These routines open an SQLite database file as specified by the
2612 ** filename argument. ^The filename argument is interpreted as UTF-8 for
2613 ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
2614 ** order for sqlite3_open16(). ^(A [database connection] handle is usually
2615 ** returned in *ppDb, even if an error occurs. The only exception is that
2616 ** if SQLite is unable to allocate memory to hold the [sqlite3] object,
2617 ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
2618 ** object.)^ ^(If the database is opened (and/or created) successfully, then
2619 ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The
2620 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
2621 ** an English language description of the error following a failure of any
2622 ** of the sqlite3_open() routines.
2623 **
2624 ** ^The default encoding for the database will be UTF-8 if
2625 ** sqlite3_open() or sqlite3_open_v2() is called and
2626 ** UTF-16 in the native byte order if sqlite3_open16() is used.
2627 **
2628 ** Whether or not an error occurs when it is opened, resources
2629 ** associated with the [database connection] handle should be released by
2630 ** passing it to [sqlite3_close()] when it is no longer required.
2631 **
2632 ** The sqlite3_open_v2() interface works like sqlite3_open()
2633 ** except that it accepts two additional parameters for additional control
2634 ** over the new database connection. ^(The flags parameter to
2635 ** sqlite3_open_v2() can take one of
2636 ** the following three values, optionally combined with the
2637 ** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE],
2638 ** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^
2639 **
2640 ** <dl>
2641 ** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
2642 ** <dd>The database is opened in read-only mode. If the database does not
2643 ** already exist, an error is returned.</dd>)^
2644 **
2645 ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
2646 ** <dd>The database is opened for reading and writing if possible, or reading
2647 ** only if the file is write protected by the operating system. In either
2648 ** case the database must already exist, otherwise an error is returned.</dd>)^
2649 **
2650 ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
2651 ** <dd>The database is opened for reading and writing, and is created if
2652 ** it does not already exist. This is the behavior that is always used for
2653 ** sqlite3_open() and sqlite3_open16().</dd>)^
2654 ** </dl>
2655 **
2656 ** If the 3rd parameter to sqlite3_open_v2() is not one of the
2657 ** combinations shown above optionally combined with other
2658 ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits]
2659 ** then the behavior is undefined.
2660 **
2661 ** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection
2662 ** opens in the multi-thread [threading mode] as long as the single-thread
2663 ** mode has not been set at compile-time or start-time. ^If the
2664 ** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens
2665 ** in the serialized [threading mode] unless single-thread was
2666 ** previously selected at compile-time or start-time.
2667 ** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be
2668 ** eligible to use [shared cache mode], regardless of whether or not shared
2669 ** cache is enabled using [sqlite3_enable_shared_cache()]. ^The
2670 ** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not
2671 ** participate in [shared cache mode] even if it is enabled.
2672 **
2673 ** ^The fourth parameter to sqlite3_open_v2() is the name of the
2674 ** [sqlite3_vfs] object that defines the operating system interface that
2675 ** the new database connection should use. ^If the fourth parameter is
2676 ** a NULL pointer then the default [sqlite3_vfs] object is used.
2677 **
2678 ** ^If the filename is ":memory:", then a private, temporary in-memory database
2679 ** is created for the connection. ^This in-memory database will vanish when
2680 ** the database connection is closed. Future versions of SQLite might
2681 ** make use of additional special filenames that begin with the ":" character.
2682 ** It is recommended that when a database filename actually does begin with
2683 ** a ":" character you should prefix the filename with a pathname such as
2684 ** "./" to avoid ambiguity.
2685 **
2686 ** ^If the filename is an empty string, then a private, temporary
2687 ** on-disk database will be created. ^This private database will be
2688 ** automatically deleted as soon as the database connection is closed.
2689 **
2690 ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3>
2691 **
2692 ** ^If [URI filename] interpretation is enabled, and the filename argument
2693 ** begins with "file:", then the filename is interpreted as a URI. ^URI
2694 ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is
2695 ** set in the fourth argument to sqlite3_open_v2(), or if it has
2696 ** been enabled globally using the [SQLITE_CONFIG_URI] option with the
2697 ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option.
2698 ** As of SQLite version 3.7.7, URI filename interpretation is turned off
2699 ** by default, but future releases of SQLite might enable URI filename
2700 ** interpretation by default. See "[URI filenames]" for additional
2701 ** information.
2702 **
2703 ** URI filenames are parsed according to RFC 3986. ^If the URI contains an
2704 ** authority, then it must be either an empty string or the string
2705 ** "localhost". ^If the authority is not an empty string or "localhost", an
2706 ** error is returned to the caller. ^The fragment component of a URI, if
2707 ** present, is ignored.
2708 **
2709 ** ^SQLite uses the path component of the URI as the name of the disk file
2710 ** which contains the database. ^If the path begins with a '/' character,
2711 ** then it is interpreted as an absolute path. ^If the path does not begin
2712 ** with a '/' (meaning that the authority section is omitted from the URI)
2713 ** then the path is interpreted as a relative path.
2714 ** ^On windows, the first component of an absolute path
2715 ** is a drive specification (e.g. "C:").
2716 **
2717 ** [[core URI query parameters]]
2718 ** The query component of a URI may contain parameters that are interpreted
2719 ** either by SQLite itself, or by a [VFS | custom VFS implementation].
2720 ** SQLite interprets the following three query parameters:
2721 **
2722 ** <ul>
2723 ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
2724 ** a VFS object that provides the operating system interface that should
2725 ** be used to access the database file on disk. ^If this option is set to
2726 ** an empty string the default VFS object is used. ^Specifying an unknown
2727 ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is
2728 ** present, then the VFS specified by the option takes precedence over
2729 ** the value passed as the fourth parameter to sqlite3_open_v2().
2730 **
2731 ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw",
2732 ** "rwc", or "memory". Attempting to set it to any other value is
2733 ** an error)^.
2734 ** ^If "ro" is specified, then the database is opened for read-only
2735 ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the
2736 ** third argument to sqlite3_open_v2(). ^If the mode option is set to
2737 ** "rw", then the database is opened for read-write (but not create)
2738 ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had
2739 ** been set. ^Value "rwc" is equivalent to setting both
2740 ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is
2741 ** set to "memory" then a pure [in-memory database] that never reads
2742 ** or writes from disk is used. ^It is an error to specify a value for
2743 ** the mode parameter that is less restrictive than that specified by
2744 ** the flags passed in the third parameter to sqlite3_open_v2().
2745 **
2746 ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or
2747 ** "private". ^Setting it to "shared" is equivalent to setting the
2748 ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to
2749 ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is
2750 ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
2751 ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in
2752 ** a URI filename, its value overrides any behavior requested by setting
2753 ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
2754 ** </ul>
2755 **
2756 ** ^Specifying an unknown parameter in the query component of a URI is not an
2757 ** error. Future versions of SQLite might understand additional query
2758 ** parameters. See "[query parameters with special meaning to SQLite]" for
2759 ** additional information.
2760 **
2761 ** [[URI filename examples]] <h3>URI filename examples</h3>
2762 **
2763 ** <table border="1" align=center cellpadding=5>
2764 ** <tr><th> URI filenames <th> Results
2765 ** <tr><td> file:data.db <td>
2766 ** Open the file "data.db" in the current directory.
2767 ** <tr><td> file:/home/fred/data.db<br>
2768 ** file:///home/fred/data.db <br>
2769 ** file://localhost/home/fred/data.db <br> <td>
2770 ** Open the database file "/home/fred/data.db".
2771 ** <tr><td> file://darkstar/home/fred/data.db <td>
2772 ** An error. "darkstar" is not a recognized authority.
2773 ** <tr><td style="white-space:nowrap">
2774 ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db
2775 ** <td> Windows only: Open the file "data.db" on fred's desktop on drive
2776 ** C:. Note that the %20 escaping in this example is not strictly
2777 ** necessary - space characters can be used literally
2778 ** in URI filenames.
2779 ** <tr><td> file:data.db?mode=ro&cache=private <td>
2780 ** Open file "data.db" in the current directory for read-only access.
2781 ** Regardless of whether or not shared-cache mode is enabled by
2782 ** default, use a private cache.
2783 ** <tr><td> file:/home/fred/data.db?vfs=unix-nolock <td>
2784 ** Open file "/home/fred/data.db". Use the special VFS "unix-nolock".
2785 ** <tr><td> file:data.db?mode=readonly <td>
2786 ** An error. "readonly" is not a valid option for the "mode" parameter.
2787 ** </table>
2788 **
2789 ** ^URI hexadecimal escape sequences (%HH) are supported within the path and
2790 ** query components of a URI. A hexadecimal escape sequence consists of a
2791 ** percent sign - "%" - followed by exactly two hexadecimal digits
2792 ** specifying an octet value. ^Before the path or query components of a
2793 ** URI filename are interpreted, they are encoded using UTF-8 and all
2794 ** hexadecimal escape sequences replaced by a single byte containing the
2795 ** corresponding octet. If this process generates an invalid UTF-8 encoding,
2796 ** the results are undefined.
2797 **
2798 ** <b>Note to Windows users:</b> The encoding used for the filename argument
2799 ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
2800 ** codepage is currently defined. Filenames containing international
2801 ** characters must be converted to UTF-8 prior to passing them into
2802 ** sqlite3_open() or sqlite3_open_v2().
2803 **
2804 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set
2805 ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various
2806 ** features that require the use of temporary files may fail.
2807 **
2808 ** See also: [sqlite3_temp_directory]
2809 */
2811  const char *filename, /* Database filename (UTF-8) */
2812  sqlite3 **ppDb /* OUT: SQLite db handle */
2813 );
2815  const void *filename, /* Database filename (UTF-16) */
2816  sqlite3 **ppDb /* OUT: SQLite db handle */
2817 );
2819  const char *filename, /* Database filename (UTF-8) */
2820  sqlite3 **ppDb, /* OUT: SQLite db handle */
2821  int flags, /* Flags */
2822  const char *zVfs /* Name of VFS module to use */
2823 );
2824 
2825 /*
2826 ** CAPI3REF: Obtain Values For URI Parameters
2827 **
2828 ** These are utility routines, useful to VFS implementations, that check
2829 ** to see if a database file was a URI that contained a specific query
2830 ** parameter, and if so obtains the value of that query parameter.
2831 **
2832 ** If F is the database filename pointer passed into the xOpen() method of
2833 ** a VFS implementation when the flags parameter to xOpen() has one or
2834 ** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and
2835 ** P is the name of the query parameter, then
2836 ** sqlite3_uri_parameter(F,P) returns the value of the P
2837 ** parameter if it exists or a NULL pointer if P does not appear as a
2838 ** query parameter on F. If P is a query parameter of F
2839 ** has no explicit value, then sqlite3_uri_parameter(F,P) returns
2840 ** a pointer to an empty string.
2841 **
2842 ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean
2843 ** parameter and returns true (1) or false (0) according to the value
2844 ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the
2845 ** value of query parameter P is one of "yes", "true", or "on" in any
2846 ** case or if the value begins with a non-zero number. The
2847 ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of
2848 ** query parameter P is one of "no", "false", or "off" in any case or
2849 ** if the value begins with a numeric zero. If P is not a query
2850 ** parameter on F or if the value of P is does not match any of the
2851 ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0).
2852 **
2853 ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a
2854 ** 64-bit signed integer and returns that integer, or D if P does not
2855 ** exist. If the value of P is something other than an integer, then
2856 ** zero is returned.
2857 **
2858 ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and
2859 ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and
2860 ** is not a database file pathname pointer that SQLite passed into the xOpen
2861 ** VFS method, then the behavior of this routine is undefined and probably
2862 ** undesirable.
2863 */
2864 SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam);
2865 SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault);
2866 SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64);
2867 
2868 
2869 /*
2870 ** CAPI3REF: Error Codes And Messages
2871 **
2872 ** ^The sqlite3_errcode() interface returns the numeric [result code] or
2873 ** [extended result code] for the most recent failed sqlite3_* API call
2874 ** associated with a [database connection]. If a prior API call failed
2875 ** but the most recent API call succeeded, the return value from
2876 ** sqlite3_errcode() is undefined. ^The sqlite3_extended_errcode()
2877 ** interface is the same except that it always returns the
2878 ** [extended result code] even when extended result codes are
2879 ** disabled.
2880 **
2881 ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
2882 ** text that describes the error, as either UTF-8 or UTF-16 respectively.
2883 ** ^(Memory to hold the error message string is managed internally.
2884 ** The application does not need to worry about freeing the result.
2885 ** However, the error string might be overwritten or deallocated by
2886 ** subsequent calls to other SQLite interface functions.)^
2887 **
2888 ** ^The sqlite3_errstr() interface returns the English-language text
2889 ** that describes the [result code], as UTF-8.
2890 ** ^(Memory to hold the error message string is managed internally
2891 ** and must not be freed by the application)^.
2892 **
2893 ** When the serialized [threading mode] is in use, it might be the
2894 ** case that a second error occurs on a separate thread in between
2895 ** the time of the first error and the call to these interfaces.
2896 ** When that happens, the second error will be reported since these
2897 ** interfaces always report the most recent result. To avoid
2898 ** this, each thread can obtain exclusive use of the [database connection] D
2899 ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
2900 ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
2901 ** all calls to the interfaces listed here are completed.
2902 **
2903 ** If an interface fails with SQLITE_MISUSE, that means the interface
2904 ** was invoked incorrectly by the application. In that case, the
2905 ** error code and message may or may not be set.
2906 */
2909 SQLITE_API const char *sqlite3_errmsg(sqlite3*);
2910 SQLITE_API const void *sqlite3_errmsg16(sqlite3*);
2911 SQLITE_API const char *sqlite3_errstr(int);
2912 
2913 /*
2914 ** CAPI3REF: SQL Statement Object
2915 ** KEYWORDS: {prepared statement} {prepared statements}
2916 **
2917 ** An instance of this object represents a single SQL statement.
2918 ** This object is variously known as a "prepared statement" or a
2919 ** "compiled SQL statement" or simply as a "statement".
2920 **
2921 ** The life of a statement object goes something like this:
2922 **
2923 ** <ol>
2924 ** <li> Create the object using [sqlite3_prepare_v2()] or a related
2925 ** function.
2926 ** <li> Bind values to [host parameters] using the sqlite3_bind_*()
2927 ** interfaces.
2928 ** <li> Run the SQL by calling [sqlite3_step()] one or more times.
2929 ** <li> Reset the statement using [sqlite3_reset()] then go back
2930 ** to step 2. Do this zero or more times.
2931 ** <li> Destroy the object using [sqlite3_finalize()].
2932 ** </ol>
2933 **
2934 ** Refer to documentation on individual methods above for additional
2935 ** information.
2936 */
2938 
2939 /*
2940 ** CAPI3REF: Run-time Limits
2941 **
2942 ** ^(This interface allows the size of various constructs to be limited
2943 ** on a connection by connection basis. The first parameter is the
2944 ** [database connection] whose limit is to be set or queried. The
2945 ** second parameter is one of the [limit categories] that define a
2946 ** class of constructs to be size limited. The third parameter is the
2947 ** new limit for that construct.)^
2948 **
2949 ** ^If the new limit is a negative number, the limit is unchanged.
2950 ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a
2951 ** [limits | hard upper bound]
2952 ** set at compile-time by a C preprocessor macro called
2953 ** [limits | SQLITE_MAX_<i>NAME</i>].
2954 ** (The "_LIMIT_" in the name is changed to "_MAX_".))^
2955 ** ^Attempts to increase a limit above its hard upper bound are
2956 ** silently truncated to the hard upper bound.
2957 **
2958 ** ^Regardless of whether or not the limit was changed, the
2959 ** [sqlite3_limit()] interface returns the prior value of the limit.
2960 ** ^Hence, to find the current value of a limit without changing it,
2961 ** simply invoke this interface with the third parameter set to -1.
2962 **
2963 ** Run-time limits are intended for use in applications that manage
2964 ** both their own internal database and also databases that are controlled
2965 ** by untrusted external sources. An example application might be a
2966 ** web browser that has its own databases for storing history and
2967 ** separate databases controlled by JavaScript applications downloaded
2968 ** off the Internet. The internal databases can be given the
2969 ** large, default limits. Databases managed by external sources can
2970 ** be given much smaller limits designed to prevent a denial of service
2971 ** attack. Developers might also want to use the [sqlite3_set_authorizer()]
2972 ** interface to further control untrusted SQL. The size of the database
2973 ** created by an untrusted script can be contained using the
2974 ** [max_page_count] [PRAGMA].
2975 **
2976 ** New run-time limit categories may be added in future releases.
2977 */
2978 SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
2979 
2980 /*
2981 ** CAPI3REF: Run-Time Limit Categories
2982 ** KEYWORDS: {limit category} {*limit categories}
2983 **
2984 ** These constants define various performance limits
2985 ** that can be lowered at run-time using [sqlite3_limit()].
2986 ** The synopsis of the meanings of the various limits is shown below.
2987 ** Additional information is available at [limits | Limits in SQLite].
2988 **
2989 ** <dl>
2990 ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt>
2991 ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
2992 **
2993 ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
2994 ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^
2995 **
2996 ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt>
2997 ** <dd>The maximum number of columns in a table definition or in the
2998 ** result set of a [SELECT] or the maximum number of columns in an index
2999 ** or in an ORDER BY or GROUP BY clause.</dd>)^
3000 **
3001 ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
3002 ** <dd>The maximum depth of the parse tree on any expression.</dd>)^
3003 **
3004 ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
3005 ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
3006 **
3007 ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt>
3008 ** <dd>The maximum number of instructions in a virtual machine program
3009 ** used to implement an SQL statement. This limit is not currently
3010 ** enforced, though that might be added in some future release of
3011 ** SQLite.</dd>)^
3012 **
3013 ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
3014 ** <dd>The maximum number of arguments on a function.</dd>)^
3015 **
3016 ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt>
3017 ** <dd>The maximum number of [ATTACH | attached databases].)^</dd>
3018 **
3019 ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]]
3020 ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
3021 ** <dd>The maximum length of the pattern argument to the [LIKE] or
3022 ** [GLOB] operators.</dd>)^
3023 **
3024 ** [[SQLITE_LIMIT_VARIABLE_NUMBER]]
3025 ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
3026 ** <dd>The maximum index number of any [parameter] in an SQL statement.)^
3027 **
3028 ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
3029 ** <dd>The maximum depth of recursion for triggers.</dd>)^
3030 ** </dl>
3031 */
3032 #define SQLITE_LIMIT_LENGTH 0
3033 #define SQLITE_LIMIT_SQL_LENGTH 1
3034 #define SQLITE_LIMIT_COLUMN 2
3035 #define SQLITE_LIMIT_EXPR_DEPTH 3
3036 #define SQLITE_LIMIT_COMPOUND_SELECT 4
3037 #define SQLITE_LIMIT_VDBE_OP 5
3038 #define SQLITE_LIMIT_FUNCTION_ARG 6
3039 #define SQLITE_LIMIT_ATTACHED 7
3040 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8
3041 #define SQLITE_LIMIT_VARIABLE_NUMBER 9
3042 #define SQLITE_LIMIT_TRIGGER_DEPTH 10
3043 
3044 /*
3045 ** CAPI3REF: Compiling An SQL Statement
3046 ** KEYWORDS: {SQL statement compiler}
3047 **
3048 ** To execute an SQL query, it must first be compiled into a byte-code
3049 ** program using one of these routines.
3050 **
3051 ** The first argument, "db", is a [database connection] obtained from a
3052 ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
3053 ** [sqlite3_open16()]. The database connection must not have been closed.
3054 **
3055 ** The second argument, "zSql", is the statement to be compiled, encoded
3056 ** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2()
3057 ** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2()
3058 ** use UTF-16.
3059 **
3060 ** ^If the nByte argument is less than zero, then zSql is read up to the
3061 ** first zero terminator. ^If nByte is non-negative, then it is the maximum
3062 ** number of bytes read from zSql. ^When nByte is non-negative, the
3063 ** zSql string ends at either the first '\000' or '\u0000' character or
3064 ** the nByte-th byte, whichever comes first. If the caller knows
3065 ** that the supplied string is nul-terminated, then there is a small
3066 ** performance advantage to be gained by passing an nByte parameter that
3067 ** is equal to the number of bytes in the input string <i>including</i>
3068 ** the nul-terminator bytes as this saves SQLite from having to
3069 ** make a copy of the input string.
3070 **
3071 ** ^If pzTail is not NULL then *pzTail is made to point to the first byte
3072 ** past the end of the first SQL statement in zSql. These routines only
3073 ** compile the first statement in zSql, so *pzTail is left pointing to
3074 ** what remains uncompiled.
3075 **
3076 ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
3077 ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set
3078 ** to NULL. ^If the input text contains no SQL (if the input is an empty
3079 ** string or a comment) then *ppStmt is set to NULL.
3080 ** The calling procedure is responsible for deleting the compiled
3081 ** SQL statement using [sqlite3_finalize()] after it has finished with it.
3082 ** ppStmt may not be NULL.
3083 **
3084 ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
3085 ** otherwise an [error code] is returned.
3086 **
3087 ** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are
3088 ** recommended for all new programs. The two older interfaces are retained
3089 ** for backwards compatibility, but their use is discouraged.
3090 ** ^In the "v2" interfaces, the prepared statement
3091 ** that is returned (the [sqlite3_stmt] object) contains a copy of the
3092 ** original SQL text. This causes the [sqlite3_step()] interface to
3093 ** behave differently in three ways:
3094 **
3095 ** <ol>
3096 ** <li>
3097 ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
3098 ** always used to do, [sqlite3_step()] will automatically recompile the SQL
3099 ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY]
3100 ** retries will occur before sqlite3_step() gives up and returns an error.
3101 ** </li>
3102 **
3103 ** <li>
3104 ** ^When an error occurs, [sqlite3_step()] will return one of the detailed
3105 ** [error codes] or [extended error codes]. ^The legacy behavior was that
3106 ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
3107 ** and the application would have to make a second call to [sqlite3_reset()]
3108 ** in order to find the underlying cause of the problem. With the "v2" prepare
3109 ** interfaces, the underlying reason for the error is returned immediately.
3110 ** </li>
3111 **
3112 ** <li>
3113 ** ^If the specific value bound to [parameter | host parameter] in the
3114 ** WHERE clause might influence the choice of query plan for a statement,
3115 ** then the statement will be automatically recompiled, as if there had been
3116 ** a schema change, on the first [sqlite3_step()] call following any change
3117 ** to the [sqlite3_bind_text | bindings] of that [parameter].
3118 ** ^The specific value of WHERE-clause [parameter] might influence the
3119 ** choice of query plan if the parameter is the left-hand side of a [LIKE]
3120 ** or [GLOB] operator or if the parameter is compared to an indexed column
3121 ** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled.
3122 ** </li>
3123 ** </ol>
3124 */
3126  sqlite3 *db, /* Database handle */
3127  const char *zSql, /* SQL statement, UTF-8 encoded */
3128  int nByte, /* Maximum length of zSql in bytes. */
3129  sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3130  const char **pzTail /* OUT: Pointer to unused portion of zSql */
3131 );
3133  sqlite3 *db, /* Database handle */
3134  const char *zSql, /* SQL statement, UTF-8 encoded */
3135  int nByte, /* Maximum length of zSql in bytes. */
3136  sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3137  const char **pzTail /* OUT: Pointer to unused portion of zSql */
3138 );
3140  sqlite3 *db, /* Database handle */
3141  const void *zSql, /* SQL statement, UTF-16 encoded */
3142  int nByte, /* Maximum length of zSql in bytes. */
3143  sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3144  const void **pzTail /* OUT: Pointer to unused portion of zSql */
3145 );
3147  sqlite3 *db, /* Database handle */
3148  const void *zSql, /* SQL statement, UTF-16 encoded */
3149  int nByte, /* Maximum length of zSql in bytes. */
3150  sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3151  const void **pzTail /* OUT: Pointer to unused portion of zSql */
3152 );
3153 
3154 /*
3155 ** CAPI3REF: Retrieving Statement SQL
3156 **
3157 ** ^This interface can be used to retrieve a saved copy of the original
3158 ** SQL text used to create a [prepared statement] if that statement was
3159 ** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()].
3160 */
3161 SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt);
3162 
3163 /*
3164 ** CAPI3REF: Determine If An SQL Statement Writes The Database
3165 **
3166 ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
3167 ** and only if the [prepared statement] X makes no direct changes to
3168 ** the content of the database file.
3169 **
3170 ** Note that [application-defined SQL functions] or
3171 ** [virtual tables] might change the database indirectly as a side effect.
3172 ** ^(For example, if an application defines a function "eval()" that
3173 ** calls [sqlite3_exec()], then the following SQL statement would
3174 ** change the database file through side-effects:
3175 **
3176 ** <blockquote><pre>
3177 ** SELECT eval('DELETE FROM t1') FROM t2;
3178 ** </pre></blockquote>
3179 **
3180 ** But because the [SELECT] statement does not change the database file
3181 ** directly, sqlite3_stmt_readonly() would still return true.)^
3182 **
3183 ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
3184 ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
3185 ** since the statements themselves do not actually modify the database but
3186 ** rather they control the timing of when other statements modify the
3187 ** database. ^The [ATTACH] and [DETACH] statements also cause
3188 ** sqlite3_stmt_readonly() to return true since, while those statements
3189 ** change the configuration of a database connection, they do not make
3190 ** changes to the content of the database files on disk.
3191 */
3193 
3194 /*
3195 ** CAPI3REF: Determine If A Prepared Statement Has Been Reset
3196 **
3197 ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the
3198 ** [prepared statement] S has been stepped at least once using
3199 ** [sqlite3_step(S)] but has not run to completion and/or has not
3200 ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S)
3201 ** interface returns false if S is a NULL pointer. If S is not a
3202 ** NULL pointer and is not a pointer to a valid [prepared statement]
3203 ** object, then the behavior is undefined and probably undesirable.
3204 **
3205 ** This interface can be used in combination [sqlite3_next_stmt()]
3206 ** to locate all prepared statements associated with a database
3207 ** connection that are in need of being reset. This can be used,
3208 ** for example, in diagnostic routines to search for prepared
3209 ** statements that are holding a transaction open.
3210 */
3212 
3213 /*
3214 ** CAPI3REF: Dynamically Typed Value Object
3215 ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
3216 **
3217 ** SQLite uses the sqlite3_value object to represent all values
3218 ** that can be stored in a database table. SQLite uses dynamic typing
3219 ** for the values it stores. ^Values stored in sqlite3_value objects
3220 ** can be integers, floating point values, strings, BLOBs, or NULL.
3221 **
3222 ** An sqlite3_value object may be either "protected" or "unprotected".
3223 ** Some interfaces require a protected sqlite3_value. Other interfaces
3224 ** will accept either a protected or an unprotected sqlite3_value.
3225 ** Every interface that accepts sqlite3_value arguments specifies
3226 ** whether or not it requires a protected sqlite3_value.
3227 **
3228 ** The terms "protected" and "unprotected" refer to whether or not
3229 ** a mutex is held. An internal mutex is held for a protected
3230 ** sqlite3_value object but no mutex is held for an unprotected
3231 ** sqlite3_value object. If SQLite is compiled to be single-threaded
3232 ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
3233 ** or if SQLite is run in one of reduced mutex modes
3234 ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
3235 ** then there is no distinction between protected and unprotected
3236 ** sqlite3_value objects and they can be used interchangeably. However,
3237 ** for maximum code portability it is recommended that applications
3238 ** still make the distinction between protected and unprotected
3239 ** sqlite3_value objects even when not strictly required.
3240 **
3241 ** ^The sqlite3_value objects that are passed as parameters into the
3242 ** implementation of [application-defined SQL functions] are protected.
3243 ** ^The sqlite3_value object returned by
3244 ** [sqlite3_column_value()] is unprotected.
3245 ** Unprotected sqlite3_value objects may only be used with
3246 ** [sqlite3_result_value()] and [sqlite3_bind_value()].
3247 ** The [sqlite3_value_blob | sqlite3_value_type()] family of
3248 ** interfaces require protected sqlite3_value objects.
3249 */
3250 typedef struct Mem sqlite3_value;
3251 
3252 /*
3253 ** CAPI3REF: SQL Function Context Object
3254 **
3255 ** The context in which an SQL function executes is stored in an
3256 ** sqlite3_context object. ^A pointer to an sqlite3_context object
3257 ** is always first parameter to [application-defined SQL functions].
3258 ** The application-defined SQL function implementation will pass this
3259 ** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
3260 ** [sqlite3_aggregate_context()], [sqlite3_user_data()],
3261 ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
3262 ** and/or [sqlite3_set_auxdata()].
3263 */
3265 
3266 /*
3267 ** CAPI3REF: Binding Values To Prepared Statements
3268 ** KEYWORDS: {host parameter} {host parameters} {host parameter name}
3269 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
3270 **
3271 ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
3272 ** literals may be replaced by a [parameter] that matches one of following
3273 ** templates:
3274 **
3275 ** <ul>
3276 ** <li> ?
3277 ** <li> ?NNN
3278 ** <li> :VVV
3279 ** <li> @VVV
3280 ** <li> $VVV
3281 ** </ul>
3282 **
3283 ** In the templates above, NNN represents an integer literal,
3284 ** and VVV represents an alphanumeric identifier.)^ ^The values of these
3285 ** parameters (also called "host parameter names" or "SQL parameters")
3286 ** can be set using the sqlite3_bind_*() routines defined here.
3287 **
3288 ** ^The first argument to the sqlite3_bind_*() routines is always
3289 ** a pointer to the [sqlite3_stmt] object returned from
3290 ** [sqlite3_prepare_v2()] or its variants.
3291 **
3292 ** ^The second argument is the index of the SQL parameter to be set.
3293 ** ^The leftmost SQL parameter has an index of 1. ^When the same named
3294 ** SQL parameter is used more than once, second and subsequent
3295 ** occurrences have the same index as the first occurrence.
3296 ** ^The index for named parameters can be looked up using the
3297 ** [sqlite3_bind_parameter_index()] API if desired. ^The index
3298 ** for "?NNN" parameters is the value of NNN.
3299 ** ^The NNN value must be between 1 and the [sqlite3_limit()]
3300 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999).
3301 **
3302 ** ^The third argument is the value to bind to the parameter.
3303 ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16()
3304 ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter
3305 ** is ignored and the end result is the same as sqlite3_bind_null().
3306 **
3307 ** ^(In those routines that have a fourth argument, its value is the
3308 ** number of bytes in the parameter. To be clear: the value is the
3309 ** number of <u>bytes</u> in the value, not the number of characters.)^
3310 ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16()
3311 ** is negative, then the length of the string is
3312 ** the number of bytes up to the first zero terminator.
3313 ** If the fourth parameter to sqlite3_bind_blob() is negative, then
3314 ** the behavior is undefined.
3315 ** If a non-negative fourth parameter is provided to sqlite3_bind_text()
3316 ** or sqlite3_bind_text16() then that parameter must be the byte offset
3317 ** where the NUL terminator would occur assuming the string were NUL
3318 ** terminated. If any NUL characters occur at byte offsets less than
3319 ** the value of the fourth parameter then the resulting string value will
3320 ** contain embedded NULs. The result of expressions involving strings
3321 ** with embedded NULs is undefined.
3322 **
3323 ** ^The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and
3324 ** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or
3325 ** string after SQLite has finished with it. ^The destructor is called
3326 ** to dispose of the BLOB or string even if the call to sqlite3_bind_blob(),
3327 ** sqlite3_bind_text(), or sqlite3_bind_text16() fails.
3328 ** ^If the fifth argument is
3329 ** the special value [SQLITE_STATIC], then SQLite assumes that the
3330 ** information is in static, unmanaged space and does not need to be freed.
3331 ** ^If the fifth argument has the value [SQLITE_TRANSIENT], then
3332 ** SQLite makes its own private copy of the data immediately, before
3333 ** the sqlite3_bind_*() routine returns.
3334 **
3335 ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
3336 ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory
3337 ** (just an integer to hold its size) while it is being processed.
3338 ** Zeroblobs are intended to serve as placeholders for BLOBs whose
3339 ** content is later written using
3340 ** [sqlite3_blob_open | incremental BLOB I/O] routines.
3341 ** ^A negative value for the zeroblob results in a zero-length BLOB.
3342 **
3343 ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
3344 ** for the [prepared statement] or with a prepared statement for which
3345 ** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
3346 ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_()
3347 ** routine is passed a [prepared statement] that has been finalized, the
3348 ** result is undefined and probably harmful.
3349 **
3350 ** ^Bindings are not cleared by the [sqlite3_reset()] routine.
3351 ** ^Unbound parameters are interpreted as NULL.
3352 **
3353 ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
3354 ** [error code] if anything goes wrong.
3355 ** ^[SQLITE_RANGE] is returned if the parameter
3356 ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails.
3357 **
3358 ** See also: [sqlite3_bind_parameter_count()],
3359 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
3360 */
3361 SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
3362 SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double);
3363 SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int);
3364 SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
3366 SQLITE_API int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*));
3367 SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
3370 
3371 /*
3372 ** CAPI3REF: Number Of SQL Parameters
3373 **
3374 ** ^This routine can be used to find the number of [SQL parameters]
3375 ** in a [prepared statement]. SQL parameters are tokens of the
3376 ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
3377 ** placeholders for values that are [sqlite3_bind_blob | bound]
3378 ** to the parameters at a later time.
3379 **
3380 ** ^(This routine actually returns the index of the largest (rightmost)
3381 ** parameter. For all forms except ?NNN, this will correspond to the
3382 ** number of unique parameters. If parameters of the ?NNN form are used,
3383 ** there may be gaps in the list.)^
3384 **
3385 ** See also: [sqlite3_bind_blob|sqlite3_bind()],
3386 ** [sqlite3_bind_parameter_name()], and
3387 ** [sqlite3_bind_parameter_index()].
3388 */
3390 
3391 /*
3392 ** CAPI3REF: Name Of A Host Parameter
3393 **
3394 ** ^The sqlite3_bind_parameter_name(P,N) interface returns
3395 ** the name of the N-th [SQL parameter] in the [prepared statement] P.
3396 ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
3397 ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
3398 ** respectively.
3399 ** In other words, the initial ":" or "$" or "@" or "?"
3400 ** is included as part of the name.)^
3401 ** ^Parameters of the form "?" without a following integer have no name
3402 ** and are referred to as "nameless" or "anonymous parameters".
3403 **
3404 ** ^The first host parameter has an index of 1, not 0.
3405 **
3406 ** ^If the value N is out of range or if the N-th parameter is
3407 ** nameless, then NULL is returned. ^The returned string is
3408 ** always in UTF-8 encoding even if the named parameter was
3409 ** originally specified as UTF-16 in [sqlite3_prepare16()] or
3410 ** [sqlite3_prepare16_v2()].
3411 **
3412 ** See also: [sqlite3_bind_blob|sqlite3_bind()],
3413 ** [sqlite3_bind_parameter_count()], and
3414 ** [sqlite3_bind_parameter_index()].
3415 */
3417 
3418 /*
3419 ** CAPI3REF: Index Of A Parameter With A Given Name
3420 **
3421 ** ^Return the index of an SQL parameter given its name. ^The
3422 ** index value returned is suitable for use as the second
3423 ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero
3424 ** is returned if no matching parameter is found. ^The parameter
3425 ** name must be given in UTF-8 even if the original statement
3426 ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()].
3427 **
3428 ** See also: [sqlite3_bind_blob|sqlite3_bind()],
3429 ** [sqlite3_bind_parameter_count()], and
3430 ** [sqlite3_bind_parameter_index()].
3431 */
3432 SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
3433 
3434 /*
3435 ** CAPI3REF: Reset All Bindings On A Prepared Statement
3436 **
3437 ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
3438 ** the [sqlite3_bind_blob | bindings] on a [prepared statement].
3439 ** ^Use this routine to reset all host parameters to NULL.
3440 */
3442 
3443 /*
3444 ** CAPI3REF: Number Of Columns In A Result Set
3445 **
3446 ** ^Return the number of columns in the result set returned by the
3447 ** [prepared statement]. ^This routine returns 0 if pStmt is an SQL
3448 ** statement that does not return data (for example an [UPDATE]).
3449 **
3450 ** See also: [sqlite3_data_count()]
3451 */
3453 
3454 /*
3455 ** CAPI3REF: Column Names In A Result Set
3456 **
3457 ** ^These routines return the name assigned to a particular column
3458 ** in the result set of a [SELECT] statement. ^The sqlite3_column_name()
3459 ** interface returns a pointer to a zero-terminated UTF-8 string
3460 ** and sqlite3_column_name16() returns a pointer to a zero-terminated
3461 ** UTF-16 string. ^The first parameter is the [prepared statement]
3462 ** that implements the [SELECT] statement. ^The second parameter is the
3463 ** column number. ^The leftmost column is number 0.
3464 **
3465 ** ^The returned string pointer is valid until either the [prepared statement]
3466 ** is destroyed by [sqlite3_finalize()] or until the statement is automatically
3467 ** reprepared by the first call to [sqlite3_step()] for a particular run
3468 ** or until the next call to
3469 ** sqlite3_column_name() or sqlite3_column_name16() on the same column.
3470 **
3471 ** ^If sqlite3_malloc() fails during the processing of either routine
3472 ** (for example during a conversion from UTF-8 to UTF-16) then a
3473 ** NULL pointer is returned.
3474 **
3475 ** ^The name of a result column is the value of the "AS" clause for
3476 ** that column, if there is an AS clause. If there is no AS clause
3477 ** then the name of the column is unspecified and may change from
3478 ** one release of SQLite to the next.
3479 */
3480 SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N);
3481 SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N);
3482 
3483 /*
3484 ** CAPI3REF: Source Of Data In A Query Result
3485 **
3486 ** ^These routines provide a means to determine the database, table, and
3487 ** table column that is the origin of a particular result column in
3488 ** [SELECT] statement.
3489 ** ^The name of the database or table or column can be returned as
3490 ** either a UTF-8 or UTF-16 string. ^The _database_ routines return
3491 ** the database name, the _table_ routines return the table name, and
3492 ** the origin_ routines return the column name.
3493 ** ^The returned string is valid until the [prepared statement] is destroyed
3494 ** using [sqlite3_finalize()] or until the statement is automatically
3495 ** reprepared by the first call to [sqlite3_step()] for a particular run
3496 ** or until the same information is requested
3497 ** again in a different encoding.
3498 **
3499 ** ^The names returned are the original un-aliased names of the
3500 ** database, table, and column.
3501 **
3502 ** ^The first argument to these interfaces is a [prepared statement].
3503 ** ^These functions return information about the Nth result column returned by
3504 ** the statement, where N is the second function argument.
3505 ** ^The left-most column is column 0 for these routines.
3506 **
3507 ** ^If the Nth column returned by the statement is an expression or
3508 ** subquery and is not a column value, then all of these functions return
3509 ** NULL. ^These routine might also return NULL if a memory allocation error
3510 ** occurs. ^Otherwise, they return the name of the attached database, table,
3511 ** or column that query result column was extracted from.
3512 **
3513 ** ^As with all other SQLite APIs, those whose names end with "16" return
3514 ** UTF-16 encoded strings and the other functions return UTF-8.
3515 **
3516 ** ^These APIs are only available if the library was compiled with the
3517 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol.
3518 **
3519 ** If two or more threads call one or more of these routines against the same
3520 ** prepared statement and column at the same time then the results are
3521 ** undefined.
3522 **
3523 ** If two or more threads call one or more
3524 ** [sqlite3_column_database_name | column metadata interfaces]
3525 ** for the same [prepared statement] and result column
3526 ** at the same time then the results are undefined.
3527 */
3534 
3535 /*
3536 ** CAPI3REF: Declared Datatype Of A Query Result
3537 **
3538 ** ^(The first parameter is a [prepared statement].
3539 ** If this statement is a [SELECT] statement and the Nth column of the
3540 ** returned result set of that [SELECT] is a table column (not an
3541 ** expression or subquery) then the declared type of the table
3542 ** column is returned.)^ ^If the Nth column of the result set is an
3543 ** expression or subquery, then a NULL pointer is returned.
3544 ** ^The returned string is always UTF-8 encoded.
3545 **
3546 ** ^(For example, given the database schema:
3547 **
3548 ** CREATE TABLE t1(c1 VARIANT);
3549 **
3550 ** and the following statement to be compiled:
3551 **
3552 ** SELECT c1 + 1, c1 FROM t1;
3553 **
3554 ** this routine would return the string "VARIANT" for the second result
3555 ** column (i==1), and a NULL pointer for the first result column (i==0).)^
3556 **
3557 ** ^SQLite uses dynamic run-time typing. ^So just because a column
3558 ** is declared to contain a particular type does not mean that the
3559 ** data stored in that column is of the declared type. SQLite is
3560 ** strongly typed, but the typing is dynamic not static. ^Type
3561 ** is associated with individual values, not with the containers
3562 ** used to hold those values.
3563 */
3566 
3567 /*
3568 ** CAPI3REF: Evaluate An SQL Statement
3569 **
3570 ** After a [prepared statement] has been prepared using either
3571 ** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy
3572 ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
3573 ** must be called one or more times to evaluate the statement.
3574 **
3575 ** The details of the behavior of the sqlite3_step() interface depend
3576 ** on whether the statement was prepared using the newer "v2" interface
3577 ** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy
3578 ** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the
3579 ** new "v2" interface is recommended for new applications but the legacy
3580 ** interface will continue to be supported.
3581 **
3582 ** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
3583 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
3584 ** ^With the "v2" interface, any of the other [result codes] or
3585 ** [extended result codes] might be returned as well.
3586 **
3587 ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the
3588 ** database locks it needs to do its job. ^If the statement is a [COMMIT]
3589 ** or occurs outside of an explicit transaction, then you can retry the
3590 ** statement. If the statement is not a [COMMIT] and occurs within an
3591 ** explicit transaction then you should rollback the transaction before
3592 ** continuing.
3593 **
3594 ** ^[SQLITE_DONE] means that the statement has finished executing
3595 ** successfully. sqlite3_step() should not be called again on this virtual
3596 ** machine without first calling [sqlite3_reset()] to reset the virtual
3597 ** machine back to its initial state.
3598 **
3599 ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]
3600 ** is returned each time a new row of data is ready for processing by the
3601 ** caller. The values may be accessed using the [column access functions].
3602 ** sqlite3_step() is called again to retrieve the next row of data.
3603 **
3604 ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint
3605 ** violation) has occurred. sqlite3_step() should not be called again on
3606 ** the VM. More information may be found by calling [sqlite3_errmsg()].
3607 ** ^With the legacy interface, a more specific error code (for example,
3608 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
3609 ** can be obtained by calling [sqlite3_reset()] on the
3610 ** [prepared statement]. ^In the "v2" interface,
3611 ** the more specific error code is returned directly by sqlite3_step().
3612 **
3613 ** [SQLITE_MISUSE] means that the this routine was called inappropriately.
3614 ** Perhaps it was called on a [prepared statement] that has
3615 ** already been [sqlite3_finalize | finalized] or on one that had
3616 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could
3617 ** be the case that the same database connection is being used by two or
3618 ** more threads at the same moment in time.
3619 **
3620 ** For all versions of SQLite up to and including 3.6.23.1, a call to
3621 ** [sqlite3_reset()] was required after sqlite3_step() returned anything
3622 ** other than [SQLITE_ROW] before any subsequent invocation of
3623 ** sqlite3_step(). Failure to reset the prepared statement using
3624 ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from
3625 ** sqlite3_step(). But after version 3.6.23.1, sqlite3_step() began
3626 ** calling [sqlite3_reset()] automatically in this circumstance rather
3627 ** than returning [SQLITE_MISUSE]. This is not considered a compatibility
3628 ** break because any application that ever receives an SQLITE_MISUSE error
3629 ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option
3630 ** can be used to restore the legacy behavior.
3631 **
3632 ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
3633 ** API always returns a generic error code, [SQLITE_ERROR], following any
3634 ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call
3635 ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
3636 ** specific [error codes] that better describes the error.
3637 ** We admit that this is a goofy design. The problem has been fixed
3638 ** with the "v2" interface. If you prepare all of your SQL statements
3639 ** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead
3640 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
3641 ** then the more specific [error codes] are returned directly
3642 ** by sqlite3_step(). The use of the "v2" interface is recommended.
3643 */
3645 
3646 /*
3647 ** CAPI3REF: Number of columns in a result set
3648 **
3649 ** ^The sqlite3_data_count(P) interface returns the number of columns in the
3650 ** current row of the result set of [prepared statement] P.
3651 ** ^If prepared statement P does not have results ready to return
3652 ** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of
3653 ** interfaces) then sqlite3_data_count(P) returns 0.
3654 ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer.
3655 ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to
3656 ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P)
3657 ** will return non-zero if previous call to [sqlite3_step](P) returned
3658 ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum]
3659 ** where it always returns zero since each step of that multi-step
3660 ** pragma returns 0 columns of data.
3661 **
3662 ** See also: [sqlite3_column_count()]
3663 */
3665 
3666 /*
3667 ** CAPI3REF: Fundamental Datatypes
3668 ** KEYWORDS: SQLITE_TEXT
3669 **
3670 ** ^(Every value in SQLite has one of five fundamental datatypes:
3671 **
3672 ** <ul>
3673 ** <li> 64-bit signed integer
3674 ** <li> 64-bit IEEE floating point number
3675 ** <li> string
3676 ** <li> BLOB
3677 ** <li> NULL
3678 ** </ul>)^
3679 **
3680 ** These constants are codes for each of those types.
3681 **
3682 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2
3683 ** for a completely different meaning. Software that links against both
3684 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
3685 ** SQLITE_TEXT.
3686 */
3687 #define SQLITE_INTEGER 1
3688 #define SQLITE_FLOAT 2
3689 #define SQLITE_BLOB 4
3690 #define SQLITE_NULL 5
3691 #ifdef SQLITE_TEXT
3692 # undef SQLITE_TEXT
3693 #else
3694 # define SQLITE_TEXT 3
3695 #endif
3696 #define SQLITE3_TEXT 3
3697 
3698 /*
3699 ** CAPI3REF: Result Values From A Query
3700 ** KEYWORDS: {column access functions}
3701 **
3702 ** These routines form the "result set" interface.
3703 **
3704 ** ^These routines return information about a single column of the current
3705 ** result row of a query. ^In every case the first argument is a pointer
3706 ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
3707 ** that was returned from [sqlite3_prepare_v2()] or one of its variants)
3708 ** and the second argument is the index of the column for which information
3709 ** should be returned. ^The leftmost column of the result set has the index 0.
3710 ** ^The number of columns in the result can be determined using
3711 ** [sqlite3_column_count()].
3712 **
3713 ** If the SQL statement does not currently point to a valid row, or if the
3714 ** column index is out of range, the result is undefined.
3715 ** These routines may only be called when the most recent call to
3716 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither
3717 ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
3718 ** If any of these routines are called after [sqlite3_reset()] or
3719 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned
3720 ** something other than [SQLITE_ROW], the results are undefined.
3721 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
3722 ** are called from a different thread while any of these routines
3723 ** are pending, then the results are undefined.
3724 **
3725 ** ^The sqlite3_column_type() routine returns the
3726 ** [SQLITE_INTEGER | datatype code] for the initial data type
3727 ** of the result column. ^The returned value is one of [SQLITE_INTEGER],
3728 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value
3729 ** returned by sqlite3_column_type() is only meaningful if no type
3730 ** conversions have occurred as described below. After a type conversion,
3731 ** the value returned by sqlite3_column_type() is undefined. Future
3732 ** versions of SQLite may change the behavior of sqlite3_column_type()
3733 ** following a type conversion.
3734 **
3735 ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
3736 ** routine returns the number of bytes in that BLOB or string.
3737 ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
3738 ** the string to UTF-8 and then returns the number of bytes.
3739 ** ^If the result is a numeric value then sqlite3_column_bytes() uses
3740 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
3741 ** the number of bytes in that string.
3742 ** ^If the result is NULL, then sqlite3_column_bytes() returns zero.
3743 **
3744 ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16()
3745 ** routine returns the number of bytes in that BLOB or string.
3746 ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts
3747 ** the string to UTF-16 and then returns the number of bytes.
3748 ** ^If the result is a numeric value then sqlite3_column_bytes16() uses
3749 ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns
3750 ** the number of bytes in that string.
3751 ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero.
3752 **
3753 ** ^The values returned by [sqlite3_column_bytes()] and
3754 ** [sqlite3_column_bytes16()] do not include the zero terminators at the end
3755 ** of the string. ^For clarity: the values returned by
3756 ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of
3757 ** bytes in the string, not the number of characters.
3758 **
3759 ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
3760 ** even empty strings, are always zero-terminated. ^The return
3761 ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.
3762 **
3763 ** ^The object returned by [sqlite3_column_value()] is an
3764 ** [unprotected sqlite3_value] object. An unprotected sqlite3_value object
3765 ** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()].
3766 ** If the [unprotected sqlite3_value] object returned by
3767 ** [sqlite3_column_value()] is used in any other way, including calls
3768 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
3769 ** or [sqlite3_value_bytes()], then the behavior is undefined.
3770 **
3771 ** These routines attempt to convert the value where appropriate. ^For
3772 ** example, if the internal representation is FLOAT and a text result
3773 ** is requested, [sqlite3_snprintf()] is used internally to perform the
3774 ** conversion automatically. ^(The following table details the conversions
3775 ** that are applied:
3776 **
3777 ** <blockquote>
3778 ** <table border="1">
3779 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion
3780 **
3781 ** <tr><td> NULL <td> INTEGER <td> Result is 0
3782 ** <tr><td> NULL <td> FLOAT <td> Result is 0.0
3783 ** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer
3784 ** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer
3785 ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float
3786 ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer
3787 ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT
3788 ** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER
3789 ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float
3790 ** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB
3791 ** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER
3792 ** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL
3793 ** <tr><td> TEXT <td> BLOB <td> No change
3794 ** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER
3795 ** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL
3796 ** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed
3797 ** </table>
3798 ** </blockquote>)^
3799 **
3800 ** The table above makes reference to standard C library functions atoi()
3801 ** and atof(). SQLite does not really use these functions. It has its
3802 ** own equivalent internal routines. The atoi() and atof() names are
3803 ** used in the table for brevity and because they are familiar to most
3804 ** C programmers.
3805 **
3806 ** Note that when type conversions occur, pointers returned by prior
3807 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
3808 ** sqlite3_column_text16() may be invalidated.
3809 ** Type conversions and pointer invalidations might occur
3810 ** in the following cases:
3811 **
3812 ** <ul>
3813 ** <li> The initial content is a BLOB and sqlite3_column_text() or
3814 ** sqlite3_column_text16() is called. A zero-terminator might
3815 ** need to be added to the string.</li>
3816 ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
3817 ** sqlite3_column_text16() is called. The content must be converted
3818 ** to UTF-16.</li>
3819 ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
3820 ** sqlite3_column_text() is called. The content must be converted
3821 ** to UTF-8.</li>
3822 ** </ul>
3823 **
3824 ** ^Conversions between UTF-16be and UTF-16le are always done in place and do
3825 ** not invalidate a prior pointer, though of course the content of the buffer
3826 ** that the prior pointer references will have been modified. Other kinds
3827 ** of conversion are done in place when it is possible, but sometimes they
3828 ** are not possible and in those cases prior pointers are invalidated.
3829 **
3830 ** The safest and easiest to remember policy is to invoke these routines
3831 ** in one of the following ways:
3832 **
3833 ** <ul>
3834 ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
3835 ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
3836 ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
3837 ** </ul>
3838 **
3839 ** In other words, you should call sqlite3_column_text(),
3840 ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
3841 ** into the desired format, then invoke sqlite3_column_bytes() or
3842 ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls
3843 ** to sqlite3_column_text() or sqlite3_column_blob() with calls to
3844 ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
3845 ** with calls to sqlite3_column_bytes().
3846 **
3847 ** ^The pointers returned are valid until a type conversion occurs as
3848 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
3849 ** [sqlite3_finalize()] is called. ^The memory space used to hold strings
3850 ** and BLOBs is freed automatically. Do <b>not</b> pass the pointers returned
3851 ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
3852 ** [sqlite3_free()].
3853 **
3854 ** ^(If a memory allocation error occurs during the evaluation of any
3855 ** of these routines, a default value is returned. The default value
3856 ** is either the integer 0, the floating point number 0.0, or a NULL
3857 ** pointer. Subsequent calls to [sqlite3_errcode()] will return
3858 ** [SQLITE_NOMEM].)^
3859 */
3860 SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
3863 SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol);
3865 SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
3866 SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
3867 SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
3870 
3871 /*
3872 ** CAPI3REF: Destroy A Prepared Statement Object
3873 **
3874 ** ^The sqlite3_finalize() function is called to delete a [prepared statement].
3875 ** ^If the most recent evaluation of the statement encountered no errors
3876 ** or if the statement is never been evaluated, then sqlite3_finalize() returns
3877 ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then
3878 ** sqlite3_finalize(S) returns the appropriate [error code] or
3879 ** [extended error code].
3880 **
3881 ** ^The sqlite3_finalize(S) routine can be called at any point during
3882 ** the life cycle of [prepared statement] S:
3883 ** before statement S is ever evaluated, after
3884 ** one or more calls to [sqlite3_reset()], or after any call
3885 ** to [sqlite3_step()] regardless of whether or not the statement has
3886 ** completed execution.
3887 **
3888 ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op.
3889 **
3890 ** The application must finalize every [prepared statement] in order to avoid
3891 ** resource leaks. It is a grievous error for the application to try to use
3892 ** a prepared statement after it has been finalized. Any use of a prepared
3893 ** statement after it has been finalized can result in undefined and
3894 ** undesirable behavior such as segfaults and heap corruption.
3895 */
3897 
3898 /*
3899 ** CAPI3REF: Reset A Prepared Statement Object
3900 **
3901 ** The sqlite3_reset() function is called to reset a [prepared statement]
3902 ** object back to its initial state, ready to be re-executed.
3903 ** ^Any SQL statement variables that had values bound to them using
3904 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
3905 ** Use [sqlite3_clear_bindings()] to reset the bindings.
3906 **
3907 ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S
3908 ** back to the beginning of its program.
3909 **
3910 ** ^If the most recent call to [sqlite3_step(S)] for the
3911 ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE],
3912 ** or if [sqlite3_step(S)] has never before been called on S,
3913 ** then [sqlite3_reset(S)] returns [SQLITE_OK].
3914 **
3915 ** ^If the most recent call to [sqlite3_step(S)] for the
3916 ** [prepared statement] S indicated an error, then
3917 ** [sqlite3_reset(S)] returns an appropriate [error code].
3918 **
3919 ** ^The [sqlite3_reset(S)] interface does not change the values
3920 ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
3921 */
3923 
3924 /*
3925 ** CAPI3REF: Create Or Redefine SQL Functions
3926 ** KEYWORDS: {function creation routines}
3927 ** KEYWORDS: {application-defined SQL function}
3928 ** KEYWORDS: {application-defined SQL functions}
3929 **
3930 ** ^These functions (collectively known as "function creation routines")
3931 ** are used to add SQL functions or aggregates or to redefine the behavior
3932 ** of existing SQL functions or aggregates. The only differences between
3933 ** these routines are the text encoding expected for
3934 ** the second parameter (the name of the function being created)
3935 ** and the presence or absence of a destructor callback for
3936 ** the application data pointer.
3937 **
3938 ** ^The first parameter is the [database connection] to which the SQL
3939 ** function is to be added. ^If an application uses more than one database
3940 ** connection then application-defined SQL functions must be added
3941 ** to each database connection separately.
3942 **
3943 ** ^The second parameter is the name of the SQL function to be created or
3944 ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8
3945 ** representation, exclusive of the zero-terminator. ^Note that the name
3946 ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes.
3947 ** ^Any attempt to create a function with a longer name
3948 ** will result in [SQLITE_MISUSE] being returned.
3949 **
3950 ** ^The third parameter (nArg)
3951 ** is the number of arguments that the SQL function or
3952 ** aggregate takes. ^If this parameter is -1, then the SQL function or
3953 ** aggregate may take any number of arguments between 0 and the limit
3954 ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third
3955 ** parameter is less than -1 or greater than 127 then the behavior is
3956 ** undefined.
3957 **
3958 ** ^The fourth parameter, eTextRep, specifies what
3959 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for
3960 ** its parameters. Every SQL function implementation must be able to work
3961 ** with UTF-8, UTF-16le, or UTF-16be. But some implementations may be
3962 ** more efficient with one encoding than another. ^An application may
3963 ** invoke sqlite3_create_function() or sqlite3_create_function16() multiple
3964 ** times with the same function but with different values of eTextRep.
3965 ** ^When multiple implementations of the same function are available, SQLite
3966 ** will pick the one that involves the least amount of data conversion.
3967 ** If there is only a single implementation which does not care what text
3968 ** encoding is used, then the fourth argument should be [SQLITE_ANY].
3969 **
3970 ** ^(The fifth parameter is an arbitrary pointer. The implementation of the
3971 ** function can gain access to this pointer using [sqlite3_user_data()].)^
3972 **
3973 ** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are
3974 ** pointers to C-language functions that implement the SQL function or
3975 ** aggregate. ^A scalar SQL function requires an implementation of the xFunc
3976 ** callback only; NULL pointers must be passed as the xStep and xFinal
3977 ** parameters. ^An aggregate SQL function requires an implementation of xStep
3978 ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing
3979 ** SQL function or aggregate, pass NULL pointers for all three function
3980 ** callbacks.
3981 **
3982 ** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL,
3983 ** then it is destructor for the application data pointer.
3984 ** The destructor is invoked when the function is deleted, either by being
3985 ** overloaded or when the database connection closes.)^
3986 ** ^The destructor is also invoked if the call to
3987 ** sqlite3_create_function_v2() fails.
3988 ** ^When the destructor callback of the tenth parameter is invoked, it
3989 ** is passed a single argument which is a copy of the application data
3990 ** pointer which was the fifth parameter to sqlite3_create_function_v2().
3991 **
3992 ** ^It is permitted to register multiple implementations of the same
3993 ** functions with the same name but with either differing numbers of
3994 ** arguments or differing preferred text encodings. ^SQLite will use
3995 ** the implementation that most closely matches the way in which the
3996 ** SQL function is used. ^A function implementation with a non-negative
3997 ** nArg parameter is a better match than a function implementation with
3998 ** a negative nArg. ^A function where the preferred text encoding
3999 ** matches the database encoding is a better
4000 ** match than a function where the encoding is different.
4001 ** ^A function where the encoding difference is between UTF16le and UTF16be
4002 ** is a closer match than a function where the encoding difference is
4003 ** between UTF8 and UTF16.
4004 **
4005 ** ^Built-in functions may be overloaded by new application-defined functions.
4006 **
4007 ** ^An application-defined function is permitted to call other
4008 ** SQLite interfaces. However, such calls must not
4009 ** close the database connection nor finalize or reset the prepared
4010 ** statement in which the function is running.
4011 */
4013  sqlite3 *db,
4014  const char *zFunctionName,
4015  int nArg,
4016  int eTextRep,
4017  void *pApp,
4018  void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
4019  void (*xStep)(sqlite3_context*,int,sqlite3_value**),
4020  void (*xFinal)(sqlite3_context*)
4021 );
4023  sqlite3 *db,
4024  const void *zFunctionName,
4025  int nArg,
4026  int eTextRep,
4027  void *pApp,
4028  void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
4029  void (*xStep)(sqlite3_context*,int,sqlite3_value**),
4030  void (*xFinal)(sqlite3_context*)
4031 );
4033  sqlite3 *db,
4034  const char *zFunctionName,
4035  int nArg,
4036  int eTextRep,
4037  void *pApp,
4038  void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
4039  void (*xStep)(sqlite3_context*,int,sqlite3_value**),
4040  void (*xFinal)(sqlite3_context*),
4041  void(*xDestroy)(void*)
4042 );
4043 
4044 /*
4045 ** CAPI3REF: Text Encodings
4046 **
4047 ** These constant define integer codes that represent the various
4048 ** text encodings supported by SQLite.
4049 */
4050 #define SQLITE_UTF8 1
4051 #define SQLITE_UTF16LE 2
4052 #define SQLITE_UTF16BE 3
4053 #define SQLITE_UTF16 4 /* Use native byte order */
4054 #define SQLITE_ANY 5 /* sqlite3_create_function only */
4055 #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */
4056 
4057 /*
4058 ** CAPI3REF: Deprecated Functions
4059 ** DEPRECATED
4060 **
4061 ** These functions are [deprecated]. In order to maintain
4062 ** backwards compatibility with older code, these functions continue
4063 ** to be supported. However, new applications should avoid
4064 ** the use of these functions. To help encourage people to avoid
4065 ** using these functions, we are not going to tell you what they do.
4066 */
4067 #ifndef SQLITE_OMIT_DEPRECATED
4073 SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),
4074  void*,sqlite3_int64);
4075 #endif
4076 
4077 /*
4078 ** CAPI3REF: Obtaining SQL Function Parameter Values
4079 **
4080 ** The C-language implementation of SQL functions and aggregates uses
4081 ** this set of interface routines to access the parameter values on
4082 ** the function or aggregate.
4083 **
4084 ** The xFunc (for scalar functions) or xStep (for aggregates) parameters
4085 ** to [sqlite3_create_function()] and [sqlite3_create_function16()]
4086 ** define callbacks that implement the SQL functions and aggregates.
4087 ** The 3rd parameter to these callbacks is an array of pointers to
4088 ** [protected sqlite3_value] objects. There is one [sqlite3_value] object for
4089 ** each parameter to the SQL function. These routines are used to
4090 ** extract values from the [sqlite3_value] objects.
4091 **
4092 ** These routines work only with [protected sqlite3_value] objects.
4093 ** Any attempt to use these routines on an [unprotected sqlite3_value]
4094 ** object results in undefined behavior.
4095 **
4096 ** ^These routines work just like the corresponding [column access functions]
4097 ** except that these routines take a single [protected sqlite3_value] object
4098 ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
4099 **
4100 ** ^The sqlite3_value_text16() interface extracts a UTF-16 string
4101 ** in the native byte-order of the host machine. ^The
4102 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
4103 ** extract UTF-16 strings as big-endian and little-endian respectively.
4104 **
4105 ** ^(The sqlite3_value_numeric_type() interface attempts to apply
4106 ** numeric affinity to the value. This means that an attempt is
4107 ** made to convert the value to an integer or floating point. If
4108 ** such a conversion is possible without loss of information (in other
4109 ** words, if the value is a string that looks like a number)
4110 ** then the conversion is performed. Otherwise no conversion occurs.
4111 ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
4112 **
4113 ** Please pay particular attention to the fact that the pointer returned
4114 ** from [sqlite3_value_blob()], [sqlite3_value_text()], or
4115 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to
4116 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
4117 ** or [sqlite3_value_text16()].
4118 **
4119 ** These routines must be called from the same thread as
4120 ** the SQL function that supplied the [sqlite3_value*] parameters.
4121 */
4128 SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*);
4134 
4135 /*
4136 ** CAPI3REF: Obtain Aggregate Function Context
4137 **
4138 ** Implementations of aggregate SQL functions use this
4139 ** routine to allocate memory for storing their state.
4140 **
4141 ** ^The first time the sqlite3_aggregate_context(C,N) routine is called
4142 ** for a particular aggregate function, SQLite
4143 ** allocates N of memory, zeroes out that memory, and returns a pointer
4144 ** to the new memory. ^On second and subsequent calls to
4145 ** sqlite3_aggregate_context() for the same aggregate function instance,
4146 ** the same buffer is returned. Sqlite3_aggregate_context() is normally
4147 ** called once for each invocation of the xStep callback and then one
4148 ** last time when the xFinal callback is invoked. ^(When no rows match
4149 ** an aggregate query, the xStep() callback of the aggregate function
4150 ** implementation is never called and xFinal() is called exactly once.
4151 ** In those cases, sqlite3_aggregate_context() might be called for the
4152 ** first time from within xFinal().)^
4153 **
4154 ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer
4155 ** when first called if N is less than or equal to zero or if a memory
4156 ** allocate error occurs.
4157 **
4158 ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
4159 ** determined by the N parameter on first successful call. Changing the
4160 ** value of N in subsequent call to sqlite3_aggregate_context() within
4161 ** the same aggregate function instance will not resize the memory
4162 ** allocation.)^ Within the xFinal callback, it is customary to set
4163 ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no
4164 ** pointless memory allocations occur.
4165 **
4166 ** ^SQLite automatically frees the memory allocated by
4167 ** sqlite3_aggregate_context() when the aggregate query concludes.
4168 **
4169 ** The first parameter must be a copy of the
4170 ** [sqlite3_context | SQL function context] that is the first parameter
4171 ** to the xStep or xFinal callback routine that implements the aggregate
4172 ** function.
4173 **
4174 ** This routine must be called from the same thread in which
4175 ** the aggregate SQL function is running.
4176 */
4178 
4179 /*
4180 ** CAPI3REF: User Data For Functions
4181 **
4182 ** ^The sqlite3_user_data() interface returns a copy of
4183 ** the pointer that was the pUserData parameter (the 5th parameter)
4184 ** of the [sqlite3_create_function()]
4185 ** and [sqlite3_create_function16()] routines that originally
4186 ** registered the application defined function.
4187 **
4188 ** This routine must be called from the same thread in which
4189 ** the application-defined function is running.
4190 */
4192 
4193 /*
4194 ** CAPI3REF: Database Connection For Functions
4195 **
4196 ** ^The sqlite3_context_db_handle() interface returns a copy of
4197 ** the pointer to the [database connection] (the 1st parameter)
4198 ** of the [sqlite3_create_function()]
4199 ** and [sqlite3_create_function16()] routines that originally
4200 ** registered the application defined function.
4201 */
4203 
4204 /*
4205 ** CAPI3REF: Function Auxiliary Data
4206 **
4207 ** These functions may be used by (non-aggregate) SQL functions to
4208 ** associate metadata with argument values. If the same value is passed to
4209 ** multiple invocations of the same SQL function during query execution, under
4210 ** some circumstances the associated metadata may be preserved. An example
4211 ** of where this might be useful is in a regular-expression matching
4212 ** function. The compiled version of the regular expression can be stored as
4213 ** metadata associated with the pattern string.
4214 ** Then as long as the pattern string remains the same,
4215 ** the compiled regular expression can be reused on multiple
4216 ** invocations of the same function.
4217 **
4218 ** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata
4219 ** associated by the sqlite3_set_auxdata() function with the Nth argument
4220 ** value to the application-defined function. ^If there is no metadata
4221 ** associated with the function argument, this sqlite3_get_auxdata() interface
4222 ** returns a NULL pointer.
4223 **
4224 ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th
4225 ** argument of the application-defined function. ^Subsequent
4226 ** calls to sqlite3_get_auxdata(C,N) return P from the most recent
4227 ** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or
4228 ** NULL if the metadata has been discarded.
4229 ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL,
4230 ** SQLite will invoke the destructor function X with parameter P exactly
4231 ** once, when the metadata is discarded.
4232 ** SQLite is free to discard the metadata at any time, including: <ul>
4233 ** <li> when the corresponding function parameter changes, or
4234 ** <li> when [sqlite3_reset()] or [sqlite3_finalize()] is called for the
4235 ** SQL statement, or
4236 ** <li> when sqlite3_set_auxdata() is invoked again on the same parameter, or
4237 ** <li> during the original sqlite3_set_auxdata() call when a memory
4238 ** allocation error occurs. </ul>)^
4239 **
4240 ** Note the last bullet in particular. The destructor X in
4241 ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the
4242 ** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata()
4243 ** should be called near the end of the function implementation and the
4244 ** function implementation should not make any use of P after
4245 ** sqlite3_set_auxdata() has been called.
4246 **
4247 ** ^(In practice, metadata is preserved between function calls for
4248 ** function parameters that are compile-time constants, including literal
4249 ** values and [parameters] and expressions composed from the same.)^
4250 **
4251 ** These routines must be called from the same thread in which
4252 ** the SQL function is running.
4253 */
4255 SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));
4256 
4257 
4258 /*
4259 ** CAPI3REF: Constants Defining Special Destructor Behavior
4260 **
4261 ** These are special values for the destructor that is passed in as the
4262 ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor
4263 ** argument is SQLITE_STATIC, it means that the content pointer is constant
4264 ** and will never change. It does not need to be destroyed. ^The
4265 ** SQLITE_TRANSIENT value means that the content will likely change in
4266 ** the near future and that SQLite should make its own private copy of
4267 ** the content before returning.
4268 **
4269 ** The typedef is necessary to work around problems in certain
4270 ** C++ compilers.
4271 */
4272 typedef void (*sqlite3_destructor_type)(void*);
4273 #define SQLITE_STATIC ((sqlite3_destructor_type)0)
4274 #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1)
4275 
4276 /*
4277 ** CAPI3REF: Setting The Result Of An SQL Function
4278 **
4279 ** These routines are used by the xFunc or xFinal callbacks that
4280 ** implement SQL functions and aggregates. See
4281 ** [sqlite3_create_function()] and [sqlite3_create_function16()]
4282 ** for additional information.
4283 **
4284 ** These functions work very much like the [parameter binding] family of
4285 ** functions used to bind values to host parameters in prepared statements.
4286 ** Refer to the [SQL parameter] documentation for additional information.
4287 **
4288 ** ^The sqlite3_result_blob() interface sets the result from
4289 ** an application-defined function to be the BLOB whose content is pointed
4290 ** to by the second parameter and which is N bytes long where N is the
4291 ** third parameter.
4292 **
4293 ** ^The sqlite3_result_zeroblob() interfaces set the result of
4294 ** the application-defined function to be a BLOB containing all zero
4295 ** bytes and N bytes in size, where N is the value of the 2nd parameter.
4296 **
4297 ** ^The sqlite3_result_double() interface sets the result from
4298 ** an application-defined function to be a floating point value specified
4299 ** by its 2nd argument.
4300 **
4301 ** ^The sqlite3_result_error() and sqlite3_result_error16() functions
4302 ** cause the implemented SQL function to throw an exception.
4303 ** ^SQLite uses the string pointed to by the
4304 ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
4305 ** as the text of an error message. ^SQLite interprets the error
4306 ** message string from sqlite3_result_error() as UTF-8. ^SQLite
4307 ** interprets the string from sqlite3_result_error16() as UTF-16 in native
4308 ** byte order. ^If the third parameter to sqlite3_result_error()
4309 ** or sqlite3_result_error16() is negative then SQLite takes as the error
4310 ** message all text up through the first zero character.
4311 ** ^If the third parameter to sqlite3_result_error() or
4312 ** sqlite3_result_error16() is non-negative then SQLite takes that many
4313 ** bytes (not characters) from the 2nd parameter as the error message.
4314 ** ^The sqlite3_result_error() and sqlite3_result_error16()
4315 ** routines make a private copy of the error message text before
4316 ** they return. Hence, the calling function can deallocate or
4317 ** modify the text after they return without harm.
4318 ** ^The sqlite3_result_error_code() function changes the error code
4319 ** returned by SQLite as a result of an error in a function. ^By default,
4320 ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error()
4321 ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
4322 **
4323 ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an
4324 ** error indicating that a string or BLOB is too long to represent.
4325 **
4326 ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an
4327 ** error indicating that a memory allocation failed.
4328 **
4329 ** ^The sqlite3_result_int() interface sets the return value
4330 ** of the application-defined function to be the 32-bit signed integer
4331 ** value given in the 2nd argument.
4332 ** ^The sqlite3_result_int64() interface sets the return value
4333 ** of the application-defined function to be the 64-bit signed integer
4334 ** value given in the 2nd argument.
4335 **
4336 ** ^The sqlite3_result_null() interface sets the return value
4337 ** of the application-defined function to be NULL.
4338 **
4339 ** ^The sqlite3_result_text(), sqlite3_result_text16(),
4340 ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
4341 ** set the return value of the application-defined function to be
4342 ** a text string which is represented as UTF-8, UTF-16 native byte order,
4343 ** UTF-16 little endian, or UTF-16 big endian, respectively.
4344 ** ^SQLite takes the text result from the application from
4345 ** the 2nd parameter of the sqlite3_result_text* interfaces.
4346 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces
4347 ** is negative, then SQLite takes result text from the 2nd parameter
4348 ** through the first zero character.
4349 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces
4350 ** is non-negative, then as many bytes (not characters) of the text
4351 ** pointed to by the 2nd parameter are taken as the application-defined
4352 ** function result. If the 3rd parameter is non-negative, then it
4353 ** must be the byte offset into the string where the NUL terminator would
4354 ** appear if the string where NUL terminated. If any NUL characters occur
4355 ** in the string at a byte offset that is less than the value of the 3rd
4356 ** parameter, then the resulting string will contain embedded NULs and the
4357 ** result of expressions operating on strings with embedded NULs is undefined.
4358 ** ^If the 4th parameter to the sqlite3_result_text* interfaces
4359 ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
4360 ** function as the destructor on the text or BLOB result when it has
4361 ** finished using that result.
4362 ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to
4363 ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
4364 ** assumes that the text or BLOB result is in constant space and does not
4365 ** copy the content of the parameter nor call a destructor on the content
4366 ** when it has finished using that result.
4367 ** ^If the 4th parameter to the sqlite3_result_text* interfaces
4368 ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
4369 ** then SQLite makes a copy of the result into space obtained from
4370 ** from [sqlite3_malloc()] before it returns.
4371 **
4372 ** ^The sqlite3_result_value() interface sets the result of
4373 ** the application-defined function to be a copy the
4374 ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The
4375 ** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
4376 ** so that the [sqlite3_value] specified in the parameter may change or
4377 ** be deallocated after sqlite3_result_value() returns without harm.
4378 ** ^A [protected sqlite3_value] object may always be used where an
4379 ** [unprotected sqlite3_value] object is required, so either
4380 ** kind of [sqlite3_value] object can be used with this interface.
4381 **
4382 ** If these routines are called from within the different thread
4383 ** than the one containing the application-defined function that received
4384 ** the [sqlite3_context] pointer, the results are undefined.
4385 */
4386 SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
4388 SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int);
4389 SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int);
4394 SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
4396 SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
4397 SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
4398 SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
4399 SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
4402 
4403 /*
4404 ** CAPI3REF: Define New Collating Sequences
4405 **
4406 ** ^These functions add, remove, or modify a [collation] associated
4407 ** with the [database connection] specified as the first argument.
4408 **
4409 ** ^The name of the collation is a UTF-8 string
4410 ** for sqlite3_create_collation() and sqlite3_create_collation_v2()
4411 ** and a UTF-16 string in native byte order for sqlite3_create_collation16().
4412 ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are
4413 ** considered to be the same name.
4414 **
4415 ** ^(The third argument (eTextRep) must be one of the constants:
4416 ** <ul>
4417 ** <li> [SQLITE_UTF8],
4418 ** <li> [SQLITE_UTF16LE],
4419 ** <li> [SQLITE_UTF16BE],
4420 ** <li> [SQLITE_UTF16], or
4421 ** <li> [SQLITE_UTF16_ALIGNED].
4422 ** </ul>)^
4423 ** ^The eTextRep argument determines the encoding of strings passed
4424 ** to the collating function callback, xCallback.
4425 ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep
4426 ** force strings to be UTF16 with native byte order.
4427 ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin
4428 ** on an even byte address.
4429 **
4430 ** ^The fourth argument, pArg, is an application data pointer that is passed
4431 ** through as the first argument to the collating function callback.
4432 **
4433 ** ^The fifth argument, xCallback, is a pointer to the collating function.
4434 ** ^Multiple collating functions can be registered using the same name but
4435 ** with different eTextRep parameters and SQLite will use whichever
4436 ** function requires the least amount of data transformation.
4437 ** ^If the xCallback argument is NULL then the collating function is
4438 ** deleted. ^When all collating functions having the same name are deleted,
4439 ** that collation is no longer usable.
4440 **
4441 ** ^The collating function callback is invoked with a copy of the pArg
4442 ** application data pointer and with two strings in the encoding specified
4443 ** by the eTextRep argument. The collating function must return an
4444 ** integer that is negative, zero, or positive
4445 ** if the first string is less than, equal to, or greater than the second,
4446 ** respectively. A collating function must always return the same answer
4447 ** given the same inputs. If two or more collating functions are registered
4448 ** to the same collation name (using different eTextRep values) then all
4449 ** must give an equivalent answer when invoked with equivalent strings.
4450 ** The collating function must obey the following properties for all
4451 ** strings A, B, and C:
4452 **
4453 ** <ol>
4454 ** <li> If A==B then B==A.
4455 ** <li> If A==B and B==C then A==C.
4456 ** <li> If A&lt;B THEN B&gt;A.
4457 ** <li> If A&lt;B and B&lt;C then A&lt;C.
4458 ** </ol>
4459 **
4460 ** If a collating function fails any of the above constraints and that
4461 ** collating function is registered and used, then the behavior of SQLite
4462 ** is undefined.
4463 **
4464 ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()
4465 ** with the addition that the xDestroy callback is invoked on pArg when
4466 ** the collating function is deleted.
4467 ** ^Collating functions are deleted when they are overridden by later
4468 ** calls to the collation creation functions or when the
4469 ** [database connection] is closed using [sqlite3_close()].
4470 **
4471 ** ^The xDestroy callback is <u>not</u> called if the
4472 ** sqlite3_create_collation_v2() function fails. Applications that invoke
4473 ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should
4474 ** check the return code and dispose of the application data pointer
4475 ** themselves rather than expecting SQLite to deal with it for them.
4476 ** This is different from every other SQLite interface. The inconsistency
4477 ** is unfortunate but cannot be changed without breaking backwards
4478 ** compatibility.
4479 **
4480 ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
4481 */
4483  sqlite3*,
4484  const char *zName,
4485  int eTextRep,
4486  void *pArg,
4487  int(*xCompare)(void*,int,const void*,int,const void*)
4488 );
4490  sqlite3*,
4491  const char *zName,
4492  int eTextRep,
4493  void *pArg,
4494  int(*xCompare)(void*,int,const void*,int,const void*),
4495  void(*xDestroy)(void*)
4496 );
4498  sqlite3*,
4499  const void *zName,
4500  int eTextRep,
4501  void *pArg,
4502  int(*xCompare)(void*,int,const void*,int,const void*)
4503 );
4504 
4505 /*
4506 ** CAPI3REF: Collation Needed Callbacks
4507 **
4508 ** ^To avoid having to register all collation sequences before a database
4509 ** can be used, a single callback function may be registered with the
4510 ** [database connection] to be invoked whenever an undefined collation
4511 ** sequence is required.
4512 **
4513 ** ^If the function is registered using the sqlite3_collation_needed() API,
4514 ** then it is passed the names of undefined collation sequences as strings
4515 ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,
4516 ** the names are passed as UTF-16 in machine native byte order.
4517 ** ^A call to either function replaces the existing collation-needed callback.
4518 **
4519 ** ^(When the callback is invoked, the first argument passed is a copy
4520 ** of the second argument to sqlite3_collation_needed() or
4521 ** sqlite3_collation_needed16(). The second argument is the database
4522 ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
4523 ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
4524 ** sequence function required. The fourth parameter is the name of the
4525 ** required collation sequence.)^
4526 **
4527 ** The callback function should register the desired collation using
4528 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
4529 ** [sqlite3_create_collation_v2()].
4530 */
4532  sqlite3*,
4533  void*,
4534  void(*)(void*,sqlite3*,int eTextRep,const char*)
4535 );
4537  sqlite3*,
4538  void*,
4539  void(*)(void*,sqlite3*,int eTextRep,const void*)
4540 );
4541 
4542 #ifdef SQLITE_HAS_CODEC
4543 /*
4544 ** Specify the key for an encrypted database. This routine should be
4545 ** called right after sqlite3_open().
4546 **
4547 ** The code to implement this API is not available in the public release
4548 ** of SQLite.
4549 */
4550 SQLITE_API int sqlite3_key(
4551  sqlite3 *db, /* Database to be rekeyed */
4552  const void *pKey, int nKey /* The key */
4553 );
4554 SQLITE_API int sqlite3_key_v2(
4555  sqlite3 *db, /* Database to be rekeyed */
4556  const char *zDbName, /* Name of the database */
4557  const void *pKey, int nKey /* The key */
4558 );
4559 
4560 /*
4561 ** Change the key on an open database. If the current database is not
4562 ** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the
4563 ** database is decrypted.
4564 **
4565 ** The code to implement this API is not available in the public release
4566 ** of SQLite.
4567 */
4568 SQLITE_API int sqlite3_rekey(
4569  sqlite3 *db, /* Database to be rekeyed */
4570  const void *pKey, int nKey /* The new key */
4571 );
4572 SQLITE_API int sqlite3_rekey_v2(
4573  sqlite3 *db, /* Database to be rekeyed */
4574  const char *zDbName, /* Name of the database */
4575  const void *pKey, int nKey /* The new key */
4576 );
4577 
4578 /*
4579 ** Specify the activation key for a SEE database. Unless
4580 ** activated, none of the SEE routines will work.
4581 */
4582 SQLITE_API void sqlite3_activate_see(
4583  const char *zPassPhrase /* Activation phrase */
4584 );
4585 #endif
4586 
4587 #ifdef SQLITE_ENABLE_CEROD
4588 /*
4589 ** Specify the activation key for a CEROD database. Unless
4590 ** activated, none of the CEROD routines will work.
4591 */
4592 SQLITE_API void sqlite3_activate_cerod(
4593  const char *zPassPhrase /* Activation phrase */
4594 );
4595 #endif
4596 
4597 /*
4598 ** CAPI3REF: Suspend Execution For A Short Time
4599 **
4600 ** The sqlite3_sleep() function causes the current thread to suspend execution
4601 ** for at least a number of milliseconds specified in its parameter.
4602 **
4603 ** If the operating system does not support sleep requests with
4604 ** millisecond time resolution, then the time will be rounded up to
4605 ** the nearest second. The number of milliseconds of sleep actually
4606 ** requested from the operating system is returned.
4607 **
4608 ** ^SQLite implements this interface by calling the xSleep()
4609 ** method of the default [sqlite3_vfs] object. If the xSleep() method
4610 ** of the default VFS is not implemented correctly, or not implemented at
4611 ** all, then the behavior of sqlite3_sleep() may deviate from the description
4612 ** in the previous paragraphs.
4613 */
4614 SQLITE_API int sqlite3_sleep(int);
4615 
4616 /*
4617 ** CAPI3REF: Name Of The Folder Holding Temporary Files
4618 **
4619 ** ^(If this global variable is made to point to a string which is
4620 ** the name of a folder (a.k.a. directory), then all temporary files
4621 ** created by SQLite when using a built-in [sqlite3_vfs | VFS]
4622 ** will be placed in that directory.)^ ^If this variable
4623 ** is a NULL pointer, then SQLite performs a search for an appropriate
4624 ** temporary file directory.
4625 **
4626 ** It is not safe to read or modify this variable in more than one
4627 ** thread at a time. It is not safe to read or modify this variable
4628 ** if a [database connection] is being used at the same time in a separate
4629 ** thread.
4630 ** It is intended that this variable be set once
4631 ** as part of process initialization and before any SQLite interface
4632 ** routines have been called and that this variable remain unchanged
4633 ** thereafter.
4634 **
4635 ** ^The [temp_store_directory pragma] may modify this variable and cause
4636 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
4637 ** the [temp_store_directory pragma] always assumes that any string
4638 ** that this variable points to is held in memory obtained from
4639 ** [sqlite3_malloc] and the pragma may attempt to free that memory
4640 ** using [sqlite3_free].
4641 ** Hence, if this variable is modified directly, either it should be
4642 ** made NULL or made to point to memory obtained from [sqlite3_malloc]
4643 ** or else the use of the [temp_store_directory pragma] should be avoided.
4644 **
4645 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set
4646 ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various
4647 ** features that require the use of temporary files may fail. Here is an
4648 ** example of how to do this using C++ with the Windows Runtime:
4649 **
4650 ** <blockquote><pre>
4651 ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current->
4652 ** &nbsp; TemporaryFolder->Path->Data();
4653 ** char zPathBuf&#91;MAX_PATH + 1&#93;;
4654 ** memset(zPathBuf, 0, sizeof(zPathBuf));
4655 ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf),
4656 ** &nbsp; NULL, NULL);
4657 ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf);
4658 ** </pre></blockquote>
4659 */
4661 
4662 /*
4663 ** CAPI3REF: Name Of The Folder Holding Database Files
4664 **
4665 ** ^(If this global variable is made to point to a string which is
4666 ** the name of a folder (a.k.a. directory), then all database files
4667 ** specified with a relative pathname and created or accessed by
4668 ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed
4669 ** to be relative to that directory.)^ ^If this variable is a NULL
4670 ** pointer, then SQLite assumes that all database files specified
4671 ** with a relative pathname are relative to the current directory
4672 ** for the process. Only the windows VFS makes use of this global
4673 ** variable; it is ignored by the unix VFS.
4674 **
4675 ** Changing the value of this variable while a database connection is
4676 ** open can result in a corrupt database.
4677 **
4678 ** It is not safe to read or modify this variable in more than one
4679 ** thread at a time. It is not safe to read or modify this variable
4680 ** if a [database connection] is being used at the same time in a separate
4681 ** thread.
4682 ** It is intended that this variable be set once
4683 ** as part of process initialization and before any SQLite interface
4684 ** routines have been called and that this variable remain unchanged
4685 ** thereafter.
4686 **
4687 ** ^The [data_store_directory pragma] may modify this variable and cause
4688 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
4689 ** the [data_store_directory pragma] always assumes that any string
4690 ** that this variable points to is held in memory obtained from
4691 ** [sqlite3_malloc] and the pragma may attempt to free that memory
4692 ** using [sqlite3_free].
4693 ** Hence, if this variable is modified directly, either it should be
4694 ** made NULL or made to point to memory obtained from [sqlite3_malloc]
4695 ** or else the use of the [data_store_directory pragma] should be avoided.
4696 */
4698 
4699 /*
4700 ** CAPI3REF: Test For Auto-Commit Mode
4701 ** KEYWORDS: {autocommit mode}
4702 **
4703 ** ^The sqlite3_get_autocommit() interface returns non-zero or
4704 ** zero if the given database connection is or is not in autocommit mode,
4705 ** respectively. ^Autocommit mode is on by default.
4706 ** ^Autocommit mode is disabled by a [BEGIN] statement.
4707 ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
4708 **
4709 ** If certain kinds of errors occur on a statement within a multi-statement
4710 ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
4711 ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
4712 ** transaction might be rolled back automatically. The only way to
4713 ** find out whether SQLite automatically rolled back the transaction after
4714 ** an error is to use this function.
4715 **
4716 ** If another thread changes the autocommit status of the database
4717 ** connection while this routine is running, then the return value
4718 ** is undefined.
4719 */
4721 
4722 /*
4723 ** CAPI3REF: Find The Database Handle Of A Prepared Statement
4724 **
4725 ** ^The sqlite3_db_handle interface returns the [database connection] handle
4726 ** to which a [prepared statement] belongs. ^The [database connection]
4727 ** returned by sqlite3_db_handle is the same [database connection]
4728 ** that was the first argument
4729 ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
4730 ** create the statement in the first place.
4731 */
4733 
4734 /*
4735 ** CAPI3REF: Return The Filename For A Database Connection
4736 **
4737 ** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename
4738 ** associated with database N of connection D. ^The main database file
4739 ** has the name "main". If there is no attached database N on the database
4740 ** connection D, or if database N is a temporary or in-memory database, then
4741 ** a NULL pointer is returned.
4742 **
4743 ** ^The filename returned by this function is the output of the
4744 ** xFullPathname method of the [VFS]. ^In other words, the filename
4745 ** will be an absolute pathname, even if the filename used
4746 ** to open the database originally was a URI or relative pathname.
4747 */
4748 SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName);
4749 
4750 /*
4751 ** CAPI3REF: Determine if a database is read-only
4752 **
4753 ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N
4754 ** of connection D is read-only, 0 if it is read/write, or -1 if N is not
4755 ** the name of a database on connection D.
4756 */
4757 SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName);
4758 
4759 /*
4760 ** CAPI3REF: Find the next prepared statement
4761 **
4762 ** ^This interface returns a pointer to the next [prepared statement] after
4763 ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL
4764 ** then this interface returns a pointer to the first prepared statement
4765 ** associated with the database connection pDb. ^If no prepared statement
4766 ** satisfies the conditions of this routine, it returns NULL.
4767 **
4768 ** The [database connection] pointer D in a call to
4769 ** [sqlite3_next_stmt(D,S)] must refer to an open database
4770 ** connection and in particular must not be a NULL pointer.
4771 */
4773 
4774 /*
4775 ** CAPI3REF: Commit And Rollback Notification Callbacks
4776 **
4777 ** ^The sqlite3_commit_hook() interface registers a callback
4778 ** function to be invoked whenever a transaction is [COMMIT | committed].
4779 ** ^Any callback set by a previous call to sqlite3_commit_hook()
4780 ** for the same database connection is overridden.
4781 ** ^The sqlite3_rollback_hook() interface registers a callback
4782 ** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
4783 ** ^Any callback set by a previous call to sqlite3_rollback_hook()
4784 ** for the same database connection is overridden.
4785 ** ^The pArg argument is passed through to the callback.
4786 ** ^If the callback on a commit hook function returns non-zero,
4787 ** then the commit is converted into a rollback.
4788 **
4789 ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
4790 ** return the P argument from the previous call of the same function
4791 ** on the same [database connection] D, or NULL for
4792 ** the first call for each function on D.
4793 **
4794 ** The commit and rollback hook callbacks are not reentrant.
4795 ** The callback implementation must not do anything that will modify
4796 ** the database connection that invoked the callback. Any actions
4797 ** to modify the database connection must be deferred until after the
4798 ** completion of the [sqlite3_step()] call that triggered the commit
4799 ** or rollback hook in the first place.
4800 ** Note that running any other SQL statements, including SELECT statements,
4801 ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify
4802 ** the database connections for the meaning of "modify" in this paragraph.
4803 **
4804 ** ^Registering a NULL function disables the callback.
4805 **
4806 ** ^When the commit hook callback routine returns zero, the [COMMIT]
4807 ** operation is allowed to continue normally. ^If the commit hook
4808 ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
4809 ** ^The rollback hook is invoked on a rollback that results from a commit
4810 ** hook returning non-zero, just as it would be with any other rollback.
4811 **
4812 ** ^For the purposes of this API, a transaction is said to have been
4813 ** rolled back if an explicit "ROLLBACK" statement is executed, or
4814 ** an error or constraint causes an implicit rollback to occur.
4815 ** ^The rollback callback is not invoked if a transaction is
4816 ** automatically rolled back because the database connection is closed.
4817 **
4818 ** See also the [sqlite3_update_hook()] interface.
4819 */
4820 SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
4821 SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
4822 
4823 /*
4824 ** CAPI3REF: Data Change Notification Callbacks
4825 **
4826 ** ^The sqlite3_update_hook() interface registers a callback function
4827 ** with the [database connection] identified by the first argument
4828 ** to be invoked whenever a row is updated, inserted or deleted in
4829 ** a rowid table.
4830 ** ^Any callback set by a previous call to this function
4831 ** for the same database connection is overridden.
4832 **
4833 ** ^The second argument is a pointer to the function to invoke when a
4834 ** row is updated, inserted or deleted in a rowid table.
4835 ** ^The first argument to the callback is a copy of the third argument
4836 ** to sqlite3_update_hook().
4837 ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
4838 ** or [SQLITE_UPDATE], depending on the operation that caused the callback
4839 ** to be invoked.
4840 ** ^The third and fourth arguments to the callback contain pointers to the
4841 ** database and table name containing the affected row.
4842 ** ^The final callback parameter is the [rowid] of the row.
4843 ** ^In the case of an update, this is the [rowid] after the update takes place.
4844 **
4845 ** ^(The update hook is not invoked when internal system tables are
4846 ** modified (i.e. sqlite_master and sqlite_sequence).)^
4847 ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified.
4848 **
4849 ** ^In the current implementation, the update hook
4850 ** is not invoked when duplication rows are deleted because of an
4851 ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook
4852 ** invoked when rows are deleted using the [truncate optimization].
4853 ** The exceptions defined in this paragraph might change in a future
4854 ** release of SQLite.
4855 **
4856 ** The update hook implementation must not do anything that will modify
4857 ** the database connection that invoked the update hook. Any actions
4858 ** to modify the database connection must be deferred until after the
4859 ** completion of the [sqlite3_step()] call that triggered the update hook.
4860 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
4861 ** database connections for the meaning of "modify" in this paragraph.
4862 **
4863 ** ^The sqlite3_update_hook(D,C,P) function
4864 ** returns the P argument from the previous call
4865 ** on the same [database connection] D, or NULL for
4866 ** the first call on D.
4867 **
4868 ** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()]
4869 ** interfaces.
4870 */
4872  sqlite3*,
4873  void(*)(void *,int ,char const *,char const *,sqlite3_int64),
4874  void*
4875 );
4876 
4877 /*
4878 ** CAPI3REF: Enable Or Disable Shared Pager Cache
4879 **
4880 ** ^(This routine enables or disables the sharing of the database cache
4881 ** and schema data structures between [database connection | connections]
4882 ** to the same database. Sharing is enabled if the argument is true
4883 ** and disabled if the argument is false.)^
4884 **
4885 ** ^Cache sharing is enabled and disabled for an entire process.
4886 ** This is a change as of SQLite version 3.5.0. In prior versions of SQLite,
4887 ** sharing was enabled or disabled for each thread separately.
4888 **
4889 ** ^(The cache sharing mode set by this interface effects all subsequent
4890 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
4891 ** Existing database connections continue use the sharing mode
4892 ** that was in effect at the time they were opened.)^
4893 **
4894 ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
4895 ** successfully. An [error code] is returned otherwise.)^
4896 **
4897 ** ^Shared cache is disabled by default. But this might change in
4898 ** future releases of SQLite. Applications that care about shared
4899 ** cache setting should set it explicitly.
4900 **
4901 ** This interface is threadsafe on processors where writing a
4902 ** 32-bit integer is atomic.
4903 **
4904 ** See Also: [SQLite Shared-Cache Mode]
4905 */
4907 
4908 /*
4909 ** CAPI3REF: Attempt To Free Heap Memory
4910 **
4911 ** ^The sqlite3_release_memory() interface attempts to free N bytes
4912 ** of heap memory by deallocating non-essential memory allocations
4913 ** held by the database library. Memory used to cache database
4914 ** pages to improve performance is an example of non-essential memory.
4915 ** ^sqlite3_release_memory() returns the number of bytes actually freed,
4916 ** which might be more or less than the amount requested.
4917 ** ^The sqlite3_release_memory() routine is a no-op returning zero
4918 ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT].
4919 **
4920 ** See also: [sqlite3_db_release_memory()]
4921 */
4923 
4924 /*
4925 ** CAPI3REF: Free Memory Used By A Database Connection
4926 **
4927 ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap
4928 ** memory as possible from database connection D. Unlike the
4929 ** [sqlite3_release_memory()] interface, this interface is in effect even
4930 ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is
4931 ** omitted.
4932 **
4933 ** See also: [sqlite3_release_memory()]
4934 */
4936 
4937 /*
4938 ** CAPI3REF: Impose A Limit On Heap Size
4939 **
4940 ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the
4941 ** soft limit on the amount of heap memory that may be allocated by SQLite.
4942 ** ^SQLite strives to keep heap memory utilization below the soft heap
4943 ** limit by reducing the number of pages held in the page cache
4944 ** as heap memory usages approaches the limit.
4945 ** ^The soft heap limit is "soft" because even though SQLite strives to stay
4946 ** below the limit, it will exceed the limit rather than generate
4947 ** an [SQLITE_NOMEM] error. In other words, the soft heap limit
4948 ** is advisory only.
4949 **
4950 ** ^The return value from sqlite3_soft_heap_limit64() is the size of
4951 ** the soft heap limit prior to the call, or negative in the case of an
4952 ** error. ^If the argument N is negative
4953 ** then no change is made to the soft heap limit. Hence, the current
4954 ** size of the soft heap limit can be determined by invoking
4955 ** sqlite3_soft_heap_limit64() with a negative argument.
4956 **
4957 ** ^If the argument N is zero then the soft heap limit is disabled.
4958 **
4959 ** ^(The soft heap limit is not enforced in the current implementation
4960 ** if one or more of following conditions are true:
4961 **
4962 ** <ul>
4963 ** <li> The soft heap limit is set to zero.
4964 ** <li> Memory accounting is disabled using a combination of the
4965 ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and
4966 ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.
4967 ** <li> An alternative page cache implementation is specified using
4968 ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...).
4969 ** <li> The page cache allocates from its own memory pool supplied
4970 ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than
4971 ** from the heap.
4972 ** </ul>)^
4973 **
4974 ** Beginning with SQLite version 3.7.3, the soft heap limit is enforced
4975 ** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT]
4976 ** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT],
4977 ** the soft heap limit is enforced on every memory allocation. Without
4978 ** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced
4979 ** when memory is allocated by the page cache. Testing suggests that because
4980 ** the page cache is the predominate memory user in SQLite, most
4981 ** applications will achieve adequate soft heap limit enforcement without
4982 ** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT].
4983 **
4984 ** The circumstances under which SQLite will enforce the soft heap limit may
4985 ** changes in future releases of SQLite.
4986 */
4987 SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N);
4988 
4989 /*
4990 ** CAPI3REF: Deprecated Soft Heap Limit Interface
4991 ** DEPRECATED
4992 **
4993 ** This is a deprecated version of the [sqlite3_soft_heap_limit64()]
4994 ** interface. This routine is provided for historical compatibility
4995 ** only. All new applications should use the
4996 ** [sqlite3_soft_heap_limit64()] interface rather than this one.
4997 */
4999 
5000 
5001 /*
5002 ** CAPI3REF: Extract Metadata About A Column Of A Table
5003 **
5004 ** ^This routine returns metadata about a specific column of a specific
5005 ** database table accessible using the [database connection] handle
5006 ** passed as the first function argument.
5007 **
5008 ** ^The column is identified by the second, third and fourth parameters to
5009 ** this function. ^The second parameter is either the name of the database
5010 ** (i.e. "main", "temp", or an attached database) containing the specified
5011 ** table or NULL. ^If it is NULL, then all attached databases are searched
5012 ** for the table using the same algorithm used by the database engine to
5013 ** resolve unqualified table references.
5014 **
5015 ** ^The third and fourth parameters to this function are the table and column
5016 ** name of the desired column, respectively. Neither of these parameters
5017 ** may be NULL.
5018 **
5019 ** ^Metadata is returned by writing to the memory locations passed as the 5th
5020 ** and subsequent parameters to this function. ^Any of these arguments may be
5021 ** NULL, in which case the corresponding element of metadata is omitted.
5022 **
5023 ** ^(<blockquote>
5024 ** <table border="1">
5025 ** <tr><th> Parameter <th> Output<br>Type <th> Description
5026 **
5027 ** <tr><td> 5th <td> const char* <td> Data type
5028 ** <tr><td> 6th <td> const char* <td> Name of default collation sequence
5029 ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint
5030 ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY
5031 ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT]
5032 ** </table>
5033 ** </blockquote>)^
5034 **
5035 ** ^The memory pointed to by the character pointers returned for the
5036 ** declaration type and collation sequence is valid only until the next
5037 ** call to any SQLite API function.
5038 **
5039 ** ^If the specified table is actually a view, an [error code] is returned.
5040 **
5041 ** ^If the specified column is "rowid", "oid" or "_rowid_" and an
5042 ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
5043 ** parameters are set for the explicitly declared column. ^(If there is no
5044 ** explicitly declared [INTEGER PRIMARY KEY] column, then the output
5045 ** parameters are set as follows:
5046 **
5047 ** <pre>
5048 ** data type: "INTEGER"
5049 ** collation sequence: "BINARY"
5050 ** not null: 0
5051 ** primary key: 1
5052 ** auto increment: 0
5053 ** </pre>)^
5054 **
5055 ** ^(This function may load one or more schemas from database files. If an
5056 ** error occurs during this process, or if the requested table or column
5057 ** cannot be found, an [error code] is returned and an error message left
5058 ** in the [database connection] (to be retrieved using sqlite3_errmsg()).)^
5059 **
5060 ** ^This API is only available if the library was compiled with the
5061 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined.
5062 */
5064  sqlite3 *db, /* Connection handle */
5065  const char *zDbName, /* Database name or NULL */
5066  const char *zTableName, /* Table name */
5067  const char *zColumnName, /* Column name */
5068  char const **pzDataType, /* OUTPUT: Declared data type */
5069  char const **pzCollSeq, /* OUTPUT: Collation sequence name */
5070  int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */
5071  int *pPrimaryKey, /* OUTPUT: True if column part of PK */
5072  int *pAutoinc /* OUTPUT: True if column is auto-increment */
5073 );
5074 
5075 /*
5076 ** CAPI3REF: Load An Extension
5077 **
5078 ** ^This interface loads an SQLite extension library from the named file.
5079 **
5080 ** ^The sqlite3_load_extension() interface attempts to load an
5081 ** [SQLite extension] library contained in the file zFile. If
5082 ** the file cannot be loaded directly, attempts are made to load
5083 ** with various operating-system specific extensions added.
5084 ** So for example, if "samplelib" cannot be loaded, then names like
5085 ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might
5086 ** be tried also.
5087 **
5088 ** ^The entry point is zProc.
5089 ** ^(zProc may be 0, in which case SQLite will try to come up with an
5090 ** entry point name on its own. It first tries "sqlite3_extension_init".
5091 ** If that does not work, it constructs a name "sqlite3_X_init" where the
5092 ** X is consists of the lower-case equivalent of all ASCII alphabetic
5093 ** characters in the filename from the last "/" to the first following
5094 ** "." and omitting any initial "lib".)^
5095 ** ^The sqlite3_load_extension() interface returns
5096 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
5097 ** ^If an error occurs and pzErrMsg is not 0, then the
5098 ** [sqlite3_load_extension()] interface shall attempt to
5099 ** fill *pzErrMsg with error message text stored in memory
5100 ** obtained from [sqlite3_malloc()]. The calling function
5101 ** should free this memory by calling [sqlite3_free()].
5102 **
5103 ** ^Extension loading must be enabled using
5104 ** [sqlite3_enable_load_extension()] prior to calling this API,
5105 ** otherwise an error will be returned.
5106 **
5107 ** See also the [load_extension() SQL function].
5108 */
5110  sqlite3 *db, /* Load the extension into this database connection */
5111  const char *zFile, /* Name of the shared library containing extension */
5112  const char *zProc, /* Entry point. Derived from zFile if 0 */
5113  char **pzErrMsg /* Put error message here if not 0 */
5114 );
5115 
5116 /*
5117 ** CAPI3REF: Enable Or Disable Extension Loading
5118 **
5119 ** ^So as not to open security holes in older applications that are
5120 ** unprepared to deal with [extension loading], and as a means of disabling
5121 ** [extension loading] while evaluating user-entered SQL, the following API
5122 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
5123 **
5124 ** ^Extension loading is off by default.
5125 ** ^Call the sqlite3_enable_load_extension() routine with onoff==1
5126 ** to turn extension loading on and call it with onoff==0 to turn
5127 ** it back off again.
5128 */
5130 
5131 /*
5132 ** CAPI3REF: Automatically Load Statically Linked Extensions
5133 **
5134 ** ^This interface causes the xEntryPoint() function to be invoked for
5135 ** each new [database connection] that is created. The idea here is that
5136 ** xEntryPoint() is the entry point for a statically linked [SQLite extension]
5137 ** that is to be automatically loaded into all new database connections.
5138 **
5139 ** ^(Even though the function prototype shows that xEntryPoint() takes
5140 ** no arguments and returns void, SQLite invokes xEntryPoint() with three
5141 ** arguments and expects and integer result as if the signature of the
5142 ** entry point where as follows:
5143 **
5144 ** <blockquote><pre>
5145 ** &nbsp; int xEntryPoint(
5146 ** &nbsp; sqlite3 *db,
5147 ** &nbsp; const char **pzErrMsg,
5148 ** &nbsp; const struct sqlite3_api_routines *pThunk
5149 ** &nbsp; );
5150 ** </pre></blockquote>)^
5151 **
5152 ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg
5153 ** point to an appropriate error message (obtained from [sqlite3_mprintf()])
5154 ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg
5155 ** is NULL before calling the xEntryPoint(). ^SQLite will invoke
5156 ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any
5157 ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()],
5158 ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail.
5159 **
5160 ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already
5161 ** on the list of automatic extensions is a harmless no-op. ^No entry point
5162 ** will be called more than once for each database connection that is opened.
5163 **
5164 ** See also: [sqlite3_reset_auto_extension()]
5165 ** and [sqlite3_cancel_auto_extension()]
5166 */
5167 SQLITE_API int sqlite3_auto_extension(void (*xEntryPoint)(void));
5168 
5169 /*
5170 ** CAPI3REF: Cancel Automatic Extension Loading
5171 **
5172 ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the
5173 ** initialization routine X that was registered using a prior call to
5174 ** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)]
5175 ** routine returns 1 if initialization routine X was successfully
5176 ** unregistered and it returns 0 if X was not on the list of initialization
5177 ** routines.
5178 */
5179 SQLITE_API int sqlite3_cancel_auto_extension(void (*xEntryPoint)(void));
5180 
5181 /*
5182 ** CAPI3REF: Reset Automatic Extension Loading
5183 **
5184 ** ^This interface disables all automatic extensions previously
5185 ** registered using [sqlite3_auto_extension()].
5186 */
5188 
5189 /*
5190 ** The interface to the virtual-table mechanism is currently considered
5191 ** to be experimental. The interface might change in incompatible ways.
5192 ** If this is a problem for you, do not use the interface at this time.
5193 **
5194 ** When the virtual-table mechanism stabilizes, we will declare the
5195 ** interface fixed, support it indefinitely, and remove this comment.
5196 */
5197 
5198 /*
5199 ** Structures used by the virtual table interface
5200 */
5205 
5206 /*
5207 ** CAPI3REF: Virtual Table Object
5208 ** KEYWORDS: sqlite3_module {virtual table module}
5209 **
5210 ** This structure, sometimes called a "virtual table module",
5211 ** defines the implementation of a [virtual tables].
5212 ** This structure consists mostly of methods for the module.
5213 **
5214 ** ^A virtual table module is created by filling in a persistent
5215 ** instance of this structure and passing a pointer to that instance
5216 ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
5217 ** ^The registration remains valid until it is replaced by a different
5218 ** module or until the [database connection] closes. The content
5219 ** of this structure must not change while it is registered with
5220 ** any database connection.
5221 */
5222 struct sqlite3_module {
5223  int iVersion;
5224  int (*xCreate)(sqlite3*, void *pAux,
5225  int argc, const char *const*argv,
5226  sqlite3_vtab **ppVTab, char**);
5227  int (*xConnect)(sqlite3*, void *pAux,
5228  int argc, const char *const*argv,
5229  sqlite3_vtab **ppVTab, char**);
5230  int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
5231  int (*xDisconnect)(sqlite3_vtab *pVTab);
5232  int (*xDestroy)(sqlite3_vtab *pVTab);
5233  int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
5234  int (*xClose)(sqlite3_vtab_cursor*);
5235  int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
5236  int argc, sqlite3_value **argv);
5237  int (*xNext)(sqlite3_vtab_cursor*);
5238  int (*xEof)(sqlite3_vtab_cursor*);
5239  int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
5240  int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
5241  int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
5242  int (*xBegin)(sqlite3_vtab *pVTab);
5243  int (*xSync)(sqlite3_vtab *pVTab);
5244  int (*xCommit)(sqlite3_vtab *pVTab);
5245  int (*xRollback)(sqlite3_vtab *pVTab);
5246  int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
5247  void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
5248  void **ppArg);
5249  int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
5250  /* The methods above are in version 1 of the sqlite_module object. Those
5251  ** below are for version 2 and greater. */
5252  int (*xSavepoint)(sqlite3_vtab *pVTab, int);
5253  int (*xRelease)(sqlite3_vtab *pVTab, int);
5254  int (*xRollbackTo)(sqlite3_vtab *pVTab, int);
5255 };
5256 
5257 /*
5258 ** CAPI3REF: Virtual Table Indexing Information
5259 ** KEYWORDS: sqlite3_index_info
5260 **
5261 ** The sqlite3_index_info structure and its substructures is used as part
5262 ** of the [virtual table] interface to
5263 ** pass information into and receive the reply from the [xBestIndex]
5264 ** method of a [virtual table module]. The fields under **Inputs** are the
5265 ** inputs to xBestIndex and are read-only. xBestIndex inserts its
5266 ** results into the **Outputs** fields.
5267 **
5268 ** ^(The aConstraint[] array records WHERE clause constraints of the form:
5269 **
5270 ** <blockquote>column OP expr</blockquote>
5271 **
5272 ** where OP is =, &lt;, &lt;=, &gt;, or &gt;=.)^ ^(The particular operator is
5273 ** stored in aConstraint[].op using one of the
5274 ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^
5275 ** ^(The index of the column is stored in
5276 ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the
5277 ** expr on the right-hand side can be evaluated (and thus the constraint
5278 ** is usable) and false if it cannot.)^
5279 **
5280 ** ^The optimizer automatically inverts terms of the form "expr OP column"
5281 ** and makes other simplifications to the WHERE clause in an attempt to
5282 ** get as many WHERE clause terms into the form shown above as possible.
5283 ** ^The aConstraint[] array only reports WHERE clause terms that are
5284 ** relevant to the particular virtual table being queried.
5285 **
5286 ** ^Information about the ORDER BY clause is stored in aOrderBy[].
5287 ** ^Each term of aOrderBy records a column of the ORDER BY clause.
5288 **
5289 ** The [xBestIndex] method must fill aConstraintUsage[] with information
5290 ** about what parameters to pass to xFilter. ^If argvIndex>0 then
5291 ** the right-hand side of the corresponding aConstraint[] is evaluated
5292 ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit
5293 ** is true, then the constraint is assumed to be fully handled by the
5294 ** virtual table and is not checked again by SQLite.)^
5295 **
5296 ** ^The idxNum and idxPtr values are recorded and passed into the
5297 ** [xFilter] method.
5298 ** ^[sqlite3_free()] is used to free idxPtr if and only if
5299 ** needToFreeIdxPtr is true.
5300 **
5301 ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in
5302 ** the correct order to satisfy the ORDER BY clause so that no separate
5303 ** sorting step is required.
5304 **
5305 ** ^The estimatedCost value is an estimate of the cost of a particular
5306 ** strategy. A cost of N indicates that the cost of the strategy is similar
5307 ** to a linear scan of an SQLite table with N rows. A cost of log(N)
5308 ** indicates that the expense of the operation is similar to that of a
5309 ** binary search on a unique indexed field of an SQLite table with N rows.
5310 **
5311 ** ^The estimatedRows value is an estimate of the number of rows that
5312 ** will be returned by the strategy.
5313 **
5314 ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info
5315 ** structure for SQLite version 3.8.2. If a virtual table extension is
5316 ** used with an SQLite version earlier than 3.8.2, the results of attempting
5317 ** to read or write the estimatedRows field are undefined (but are likely
5318 ** to included crashing the application). The estimatedRows field should
5319 ** therefore only be used if [sqlite3_libversion_number()] returns a
5320 ** value greater than or equal to 3008002.
5321 */
5322 struct sqlite3_index_info {
5323  /* Inputs */
5324  int nConstraint; /* Number of entries in aConstraint */
5325  struct sqlite3_index_constraint {
5326  int iColumn; /* Column on left-hand side of constraint */
5327  unsigned char op; /* Constraint operator */
5328  unsigned char usable; /* True if this constraint is usable */
5329  int iTermOffset; /* Used internally - xBestIndex should ignore */
5330  } *aConstraint; /* Table of WHERE clause constraints */
5331  int nOrderBy; /* Number of terms in the ORDER BY clause */
5332  struct sqlite3_index_orderby {
5333  int iColumn; /* Column number */
5334  unsigned char desc; /* True for DESC. False for ASC. */
5335  } *aOrderBy; /* The ORDER BY clause */
5336  /* Outputs */
5337  struct sqlite3_index_constraint_usage {
5338  int argvIndex; /* if >0, constraint is part of argv to xFilter */
5339  unsigned char omit; /* Do not code a test for this constraint */
5340  } *aConstraintUsage;
5341  int idxNum; /* Number used to identify the index */
5342  char *idxStr; /* String, possibly obtained from sqlite3_malloc */
5343  int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */
5344  int orderByConsumed; /* True if output is already ordered */
5345  double estimatedCost; /* Estimated cost of using this index */
5346  /* Fields below are only available in SQLite 3.8.2 and later */
5347  sqlite3_int64 estimatedRows; /* Estimated number of rows returned */
5348 };
5349 
5350 /*
5351 ** CAPI3REF: Virtual Table Constraint Operator Codes
5352 **
5353 ** These macros defined the allowed values for the
5354 ** [sqlite3_index_info].aConstraint[].op field. Each value represents
5355 ** an operator that is part of a constraint term in the wHERE clause of
5356 ** a query that uses a [virtual table].
5357 */
5358 #define SQLITE_INDEX_CONSTRAINT_EQ 2
5359 #define SQLITE_INDEX_CONSTRAINT_GT 4
5360 #define SQLITE_INDEX_CONSTRAINT_LE 8
5361 #define SQLITE_INDEX_CONSTRAINT_LT 16
5362 #define SQLITE_INDEX_CONSTRAINT_GE 32
5363 #define SQLITE_INDEX_CONSTRAINT_MATCH 64
5364 
5365 /*
5366 ** CAPI3REF: Register A Virtual Table Implementation
5367 **
5368 ** ^These routines are used to register a new [virtual table module] name.
5369 ** ^Module names must be registered before
5370 ** creating a new [virtual table] using the module and before using a
5371 ** preexisting [virtual table] for the module.
5372 **
5373 ** ^The module name is registered on the [database connection] specified
5374 ** by the first parameter. ^The name of the module is given by the
5375 ** second parameter. ^The third parameter is a pointer to
5376 ** the implementation of the [virtual table module]. ^The fourth
5377 ** parameter is an arbitrary client data pointer that is passed through
5378 ** into the [xCreate] and [xConnect] methods of the virtual table module
5379 ** when a new virtual table is be being created or reinitialized.
5380 **
5381 ** ^The sqlite3_create_module_v2() interface has a fifth parameter which
5382 ** is a pointer to a destructor for the pClientData. ^SQLite will
5383 ** invoke the destructor function (if it is not NULL) when SQLite
5384 ** no longer needs the pClientData pointer. ^The destructor will also
5385 ** be invoked if the call to sqlite3_create_module_v2() fails.
5386 ** ^The sqlite3_create_module()
5387 ** interface is equivalent to sqlite3_create_module_v2() with a NULL
5388 ** destructor.
5389 */
5391  sqlite3 *db, /* SQLite connection to register module with */
5392  const char *zName, /* Name of the module */
5393  const sqlite3_module *p, /* Methods for the module */
5394  void *pClientData /* Client data for xCreate/xConnect */
5395 );
5397  sqlite3 *db, /* SQLite connection to register module with */
5398  const char *zName, /* Name of the module */
5399  const sqlite3_module *p, /* Methods for the module */
5400  void *pClientData, /* Client data for xCreate/xConnect */
5401  void(*xDestroy)(void*) /* Module destructor function */
5402 );
5403 
5404 /*
5405 ** CAPI3REF: Virtual Table Instance Object
5406 ** KEYWORDS: sqlite3_vtab
5407 **
5408 ** Every [virtual table module] implementation uses a subclass
5409 ** of this object to describe a particular instance
5410 ** of the [virtual table]. Each subclass will
5411 ** be tailored to the specific needs of the module implementation.
5412 ** The purpose of this superclass is to define certain fields that are
5413 ** common to all module implementations.
5414 **
5415 ** ^Virtual tables methods can set an error message by assigning a
5416 ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should
5417 ** take care that any prior string is freed by a call to [sqlite3_free()]
5418 ** prior to assigning a new string to zErrMsg. ^After the error message
5419 ** is delivered up to the client application, the string will be automatically
5420 ** freed by sqlite3_free() and the zErrMsg field will be zeroed.
5421 */
5422 struct sqlite3_vtab {
5423  const sqlite3_module *pModule; /* The module for this virtual table */
5424  int nRef; /* NO LONGER USED */
5425  char *zErrMsg; /* Error message from sqlite3_mprintf() */
5426  /* Virtual table implementations will typically add additional fields */
5427 };
5428 
5429 /*
5430 ** CAPI3REF: Virtual Table Cursor Object
5431 ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
5432 **
5433 ** Every [virtual table module] implementation uses a subclass of the
5434 ** following structure to describe cursors that point into the
5435 ** [virtual table] and are used
5436 ** to loop through the virtual table. Cursors are created using the
5437 ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
5438 ** by the [sqlite3_module.xClose | xClose] method. Cursors are used
5439 ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
5440 ** of the module. Each module implementation will define
5441 ** the content of a cursor structure to suit its own needs.
5442 **
5443 ** This superclass exists in order to define fields of the cursor that
5444 ** are common to all implementations.
5445 */
5446 struct sqlite3_vtab_cursor {
5447  sqlite3_vtab *pVtab; /* Virtual table of this cursor */
5448  /* Virtual table implementations will typically add additional fields */
5449 };
5450 
5451 /*
5452 ** CAPI3REF: Declare The Schema Of A Virtual Table
5453 **
5454 ** ^The [xCreate] and [xConnect] methods of a
5455 ** [virtual table module] call this interface
5456 ** to declare the format (the names and datatypes of the columns) of
5457 ** the virtual tables they implement.
5458 */
5459 SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL);
5460 
5461 /*
5462 ** CAPI3REF: Overload A Function For A Virtual Table
5463 **
5464 ** ^(Virtual tables can provide alternative implementations of functions
5465 ** using the [xFindFunction] method of the [virtual table module].
5466 ** But global versions of those functions
5467 ** must exist in order to be overloaded.)^
5468 **
5469 ** ^(This API makes sure a global version of a function with a particular
5470 ** name and number of parameters exists. If no such function exists
5471 ** before this API is called, a new function is created.)^ ^The implementation
5472 ** of the new function always causes an exception to be thrown. So
5473 ** the new function is not good for anything by itself. Its only
5474 ** purpose is to be a placeholder function that can be overloaded
5475 ** by a [virtual table].
5476 */
5477 SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
5478 
5479 /*
5480 ** The interface to the virtual-table mechanism defined above (back up
5481 ** to a comment remarkably similar to this one) is currently considered
5482 ** to be experimental. The interface might change in incompatible ways.
5483 ** If this is a problem for you, do not use the interface at this time.
5484 **
5485 ** When the virtual-table mechanism stabilizes, we will declare the
5486 ** interface fixed, support it indefinitely, and remove this comment.
5487 */
5488 
5489 /*
5490 ** CAPI3REF: A Handle To An Open BLOB
5491 ** KEYWORDS: {BLOB handle} {BLOB handles}
5492 **
5493 ** An instance of this object represents an open BLOB on which
5494 ** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
5495 ** ^Objects of this type are created by [sqlite3_blob_open()]
5496 ** and destroyed by [sqlite3_blob_close()].
5497 ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
5498 ** can be used to read or write small subsections of the BLOB.
5499 ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
5500 */
5502 
5503 /*
5504 ** CAPI3REF: Open A BLOB For Incremental I/O
5505 **
5506 ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
5507 ** in row iRow, column zColumn, table zTable in database zDb;
5508 ** in other words, the same BLOB that would be selected by:
5509 **
5510 ** <pre>
5511 ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
5512 ** </pre>)^
5513 **
5514 ** ^If the flags parameter is non-zero, then the BLOB is opened for read
5515 ** and write access. ^If it is zero, the BLOB is opened for read access.
5516 ** ^It is not possible to open a column that is part of an index or primary
5517 ** key for writing. ^If [foreign key constraints] are enabled, it is
5518 ** not possible to open a column that is part of a [child key] for writing.
5519 **
5520 ** ^Note that the database name is not the filename that contains
5521 ** the database but rather the symbolic name of the database that
5522 ** appears after the AS keyword when the database is connected using [ATTACH].
5523 ** ^For the main database file, the database name is "main".
5524 ** ^For TEMP tables, the database name is "temp".
5525 **
5526 ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is written
5527 ** to *ppBlob. Otherwise an [error code] is returned and *ppBlob is set
5528 ** to be a null pointer.)^
5529 ** ^This function sets the [database connection] error code and message
5530 ** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()] and related
5531 ** functions. ^Note that the *ppBlob variable is always initialized in a
5532 ** way that makes it safe to invoke [sqlite3_blob_close()] on *ppBlob
5533 ** regardless of the success or failure of this routine.
5534 **
5535 ** ^(If the row that a BLOB handle points to is modified by an
5536 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
5537 ** then the BLOB handle is marked as "expired".
5538 ** This is true if any column of the row is changed, even a column
5539 ** other than the one the BLOB handle is open on.)^
5540 ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
5541 ** an expired BLOB handle fail with a return code of [SQLITE_ABORT].
5542 ** ^(Changes written into a BLOB prior to the BLOB expiring are not
5543 ** rolled back by the expiration of the BLOB. Such changes will eventually
5544 ** commit if the transaction continues to completion.)^
5545 **
5546 ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
5547 ** the opened blob. ^The size of a blob may not be changed by this
5548 ** interface. Use the [UPDATE] SQL command to change the size of a
5549 ** blob.
5550 **
5551 ** ^The [sqlite3_blob_open()] interface will fail for a [WITHOUT ROWID]
5552 ** table. Incremental BLOB I/O is not possible on [WITHOUT ROWID] tables.
5553 **
5554 ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
5555 ** and the built-in [zeroblob] SQL function can be used, if desired,
5556 ** to create an empty, zero-filled blob in which to read or write using
5557 ** this interface.
5558 **
5559 ** To avoid a resource leak, every open [BLOB handle] should eventually
5560 ** be released by a call to [sqlite3_blob_close()].
5561 */
5563  sqlite3*,
5564  const char *zDb,
5565  const char *zTable,
5566  const char *zColumn,
5567  sqlite3_int64 iRow,
5568  int flags,
5569  sqlite3_blob **ppBlob
5570 );
5571 
5572 /*
5573 ** CAPI3REF: Move a BLOB Handle to a New Row
5574 **
5575 ** ^This function is used to move an existing blob handle so that it points
5576 ** to a different row of the same database table. ^The new row is identified
5577 ** by the rowid value passed as the second argument. Only the row can be
5578 ** changed. ^The database, table and column on which the blob handle is open
5579 ** remain the same. Moving an existing blob handle to a new row can be
5580 ** faster than closing the existing handle and opening a new one.
5581 **
5582 ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -
5583 ** it must exist and there must be either a blob or text value stored in
5584 ** the nominated column.)^ ^If the new row is not present in the table, or if
5585 ** it does not contain a blob or text value, or if another error occurs, an
5586 ** SQLite error code is returned and the blob handle is considered aborted.
5587 ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or
5588 ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return
5589 ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle
5590 ** always returns zero.
5591 **
5592 ** ^This function sets the database handle error code and message.
5593 */
5595 
5596 /*
5597 ** CAPI3REF: Close A BLOB Handle
5598 **
5599 ** ^Closes an open [BLOB handle].
5600 **
5601 ** ^Closing a BLOB shall cause the current transaction to commit
5602 ** if there are no other BLOBs, no pending prepared statements, and the
5603 ** database connection is in [autocommit mode].
5604 ** ^If any writes were made to the BLOB, they might be held in cache
5605 ** until the close operation if they will fit.
5606 **
5607 ** ^(Closing the BLOB often forces the changes
5608 ** out to disk and so if any I/O errors occur, they will likely occur
5609 ** at the time when the BLOB is closed. Any errors that occur during
5610 ** closing are reported as a non-zero return value.)^
5611 **
5612 ** ^(The BLOB is closed unconditionally. Even if this routine returns
5613 ** an error code, the BLOB is still closed.)^
5614 **
5615 ** ^Calling this routine with a null pointer (such as would be returned
5616 ** by a failed call to [sqlite3_blob_open()]) is a harmless no-op.
5617 */
5619 
5620 /*
5621 ** CAPI3REF: Return The Size Of An Open BLOB
5622 **
5623 ** ^Returns the size in bytes of the BLOB accessible via the
5624 ** successfully opened [BLOB handle] in its only argument. ^The
5625 ** incremental blob I/O routines can only read or overwriting existing
5626 ** blob content; they cannot change the size of a blob.
5627 **
5628 ** This routine only works on a [BLOB handle] which has been created
5629 ** by a prior successful call to [sqlite3_blob_open()] and which has not
5630 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in
5631 ** to this routine results in undefined and probably undesirable behavior.
5632 */
5634 
5635 /*
5636 ** CAPI3REF: Read Data From A BLOB Incrementally
5637 **
5638 ** ^(This function is used to read data from an open [BLOB handle] into a
5639 ** caller-supplied buffer. N bytes of data are copied into buffer Z
5640 ** from the open BLOB, starting at offset iOffset.)^
5641 **
5642 ** ^If offset iOffset is less than N bytes from the end of the BLOB,
5643 ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is
5644 ** less than zero, [SQLITE_ERROR] is returned and no data is read.
5645 ** ^The size of the blob (and hence the maximum value of N+iOffset)
5646 ** can be determined using the [sqlite3_blob_bytes()] interface.
5647 **
5648 ** ^An attempt to read from an expired [BLOB handle] fails with an
5649 ** error code of [SQLITE_ABORT].
5650 **
5651 ** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
5652 ** Otherwise, an [error code] or an [extended error code] is returned.)^
5653 **
5654 ** This routine only works on a [BLOB handle] which has been created
5655 ** by a prior successful call to [sqlite3_blob_open()] and which has not
5656 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in
5657 ** to this routine results in undefined and probably undesirable behavior.
5658 **
5659 ** See also: [sqlite3_blob_write()].
5660 */
5661 SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
5662 
5663 /*
5664 ** CAPI3REF: Write Data Into A BLOB Incrementally
5665 **
5666 ** ^This function is used to write data into an open [BLOB handle] from a
5667 ** caller-supplied buffer. ^N bytes of data are copied from the buffer Z
5668 ** into the open BLOB, starting at offset iOffset.
5669 **
5670 ** ^If the [BLOB handle] passed as the first argument was not opened for
5671 ** writing (the flags parameter to [sqlite3_blob_open()] was zero),
5672 ** this function returns [SQLITE_READONLY].
5673 **
5674 ** ^This function may only modify the contents of the BLOB; it is
5675 ** not possible to increase the size of a BLOB using this API.
5676 ** ^If offset iOffset is less than N bytes from the end of the BLOB,
5677 ** [SQLITE_ERROR] is returned and no data is written. ^If N is
5678 ** less than zero [SQLITE_ERROR] is returned and no data is written.
5679 ** The size of the BLOB (and hence the maximum value of N+iOffset)
5680 ** can be determined using the [sqlite3_blob_bytes()] interface.
5681 **
5682 ** ^An attempt to write to an expired [BLOB handle] fails with an
5683 ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred
5684 ** before the [BLOB handle] expired are not rolled back by the
5685 ** expiration of the handle, though of course those changes might
5686 ** have been overwritten by the statement that expired the BLOB handle
5687 ** or by other independent statements.
5688 **
5689 ** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
5690 ** Otherwise, an [error code] or an [extended error code] is returned.)^
5691 **
5692 ** This routine only works on a [BLOB handle] which has been created
5693 ** by a prior successful call to [sqlite3_blob_open()] and which has not
5694 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in
5695 ** to this routine results in undefined and probably undesirable behavior.
5696 **
5697 ** See also: [sqlite3_blob_read()].
5698 */
5699 SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
5700 
5701 /*
5702 ** CAPI3REF: Virtual File System Objects
5703 **
5704 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object
5705 ** that SQLite uses to interact
5706 ** with the underlying operating system. Most SQLite builds come with a
5707 ** single default VFS that is appropriate for the host computer.
5708 ** New VFSes can be registered and existing VFSes can be unregistered.
5709 ** The following interfaces are provided.
5710 **
5711 ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
5712 ** ^Names are case sensitive.
5713 ** ^Names are zero-terminated UTF-8 strings.
5714 ** ^If there is no match, a NULL pointer is returned.
5715 ** ^If zVfsName is NULL then the default VFS is returned.
5716 **
5717 ** ^New VFSes are registered with sqlite3_vfs_register().
5718 ** ^Each new VFS becomes the default VFS if the makeDflt flag is set.
5719 ** ^The same VFS can be registered multiple times without injury.
5720 ** ^To make an existing VFS into the default VFS, register it again
5721 ** with the makeDflt flag set. If two different VFSes with the
5722 ** same name are registered, the behavior is undefined. If a
5723 ** VFS is registered with a name that is NULL or an empty string,
5724 ** then the behavior is undefined.
5725 **
5726 ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.
5727 ** ^(If the default VFS is unregistered, another VFS is chosen as
5728 ** the default. The choice for the new VFS is arbitrary.)^
5729 */
5730 SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
5731 SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
5733 
5734 /*
5735 ** CAPI3REF: Mutexes
5736 **
5737 ** The SQLite core uses these routines for thread
5738 ** synchronization. Though they are intended for internal
5739 ** use by SQLite, code that links against SQLite is
5740 ** permitted to use any of these routines.
5741 **
5742 ** The SQLite source code contains multiple implementations
5743 ** of these mutex routines. An appropriate implementation
5744 ** is selected automatically at compile-time. ^(The following
5745 ** implementations are available in the SQLite core:
5746 **
5747 ** <ul>
5748 ** <li> SQLITE_MUTEX_PTHREADS
5749 ** <li> SQLITE_MUTEX_W32
5750 ** <li> SQLITE_MUTEX_NOOP
5751 ** </ul>)^
5752 **
5753 ** ^The SQLITE_MUTEX_NOOP implementation is a set of routines
5754 ** that does no real locking and is appropriate for use in
5755 ** a single-threaded application. ^The SQLITE_MUTEX_PTHREADS and
5756 ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix
5757 ** and Windows.
5758 **
5759 ** ^(If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
5760 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
5761 ** implementation is included with the library. In this case the
5762 ** application must supply a custom mutex implementation using the
5763 ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
5764 ** before calling sqlite3_initialize() or any other public sqlite3_
5765 ** function that calls sqlite3_initialize().)^
5766 **
5767 ** ^The sqlite3_mutex_alloc() routine allocates a new
5768 ** mutex and returns a pointer to it. ^If it returns NULL
5769 ** that means that a mutex could not be allocated. ^SQLite
5770 ** will unwind its stack and return an error. ^(The argument
5771 ** to sqlite3_mutex_alloc() is one of these integer constants:
5772 **
5773 ** <ul>
5774 ** <li> SQLITE_MUTEX_FAST
5775 ** <li> SQLITE_MUTEX_RECURSIVE
5776 ** <li> SQLITE_MUTEX_STATIC_MASTER
5777 ** <li> SQLITE_MUTEX_STATIC_MEM
5778 ** <li> SQLITE_MUTEX_STATIC_MEM2
5779 ** <li> SQLITE_MUTEX_STATIC_PRNG
5780 ** <li> SQLITE_MUTEX_STATIC_LRU
5781 ** <li> SQLITE_MUTEX_STATIC_LRU2
5782 ** </ul>)^
5783 **
5784 ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
5785 ** cause sqlite3_mutex_alloc() to create
5786 ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
5787 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
5788 ** The mutex implementation does not need to make a distinction
5789 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
5790 ** not want to. ^SQLite will only request a recursive mutex in
5791 ** cases where it really needs one. ^If a faster non-recursive mutex
5792 ** implementation is available on the host platform, the mutex subsystem
5793 ** might return such a mutex in response to SQLITE_MUTEX_FAST.
5794 **
5795 ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
5796 ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
5797 ** a pointer to a static preexisting mutex. ^Six static mutexes are
5798 ** used by the current version of SQLite. Future versions of SQLite
5799 ** may add additional static mutexes. Static mutexes are for internal
5800 ** use by SQLite only. Applications that use SQLite mutexes should
5801 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
5802 ** SQLITE_MUTEX_RECURSIVE.
5803 **
5804 ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
5805 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
5806 ** returns a different mutex on every call. ^But for the static
5807 ** mutex types, the same mutex is returned on every call that has
5808 ** the same type number.
5809 **
5810 ** ^The sqlite3_mutex_free() routine deallocates a previously
5811 ** allocated dynamic mutex. ^SQLite is careful to deallocate every
5812 ** dynamic mutex that it allocates. The dynamic mutexes must not be in
5813 ** use when they are deallocated. Attempting to deallocate a static
5814 ** mutex results in undefined behavior. ^SQLite never deallocates
5815 ** a static mutex.
5816 **
5817 ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
5818 ** to enter a mutex. ^If another thread is already within the mutex,
5819 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
5820 ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
5821 ** upon successful entry. ^(Mutexes created using
5822 ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
5823 ** In such cases the,
5824 ** mutex must be exited an equal number of times before another thread
5825 ** can enter.)^ ^(If the same thread tries to enter any other
5826 ** kind of mutex more than once, the behavior is undefined.
5827 ** SQLite will never exhibit
5828 ** such behavior in its own use of mutexes.)^
5829 **
5830 ** ^(Some systems (for example, Windows 95) do not support the operation
5831 ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try()
5832 ** will always return SQLITE_BUSY. The SQLite core only ever uses
5833 ** sqlite3_mutex_try() as an optimization so this is acceptable behavior.)^
5834 **
5835 ** ^The sqlite3_mutex_leave() routine exits a mutex that was
5836 ** previously entered by the same thread. ^(The behavior
5837 ** is undefined if the mutex is not currently entered by the
5838 ** calling thread or is not currently allocated. SQLite will
5839 ** never do either.)^
5840 **
5841 ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or
5842 ** sqlite3_mutex_leave() is a NULL pointer, then all three routines
5843 ** behave as no-ops.
5844 **
5845 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
5846 */
5852 
5853 /*
5854 ** CAPI3REF: Mutex Methods Object
5855 **
5856 ** An instance of this structure defines the low-level routines
5857 ** used to allocate and use mutexes.
5858 **
5859 ** Usually, the default mutex implementations provided by SQLite are
5860 ** sufficient, however the user has the option of substituting a custom
5861 ** implementation for specialized deployments or systems for which SQLite
5862 ** does not provide a suitable implementation. In this case, the user
5863 ** creates and populates an instance of this structure to pass
5864 ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
5865 ** Additionally, an instance of this structure can be used as an
5866 ** output variable when querying the system for the current mutex
5867 ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
5868 **
5869 ** ^The xMutexInit method defined by this structure is invoked as
5870 ** part of system initialization by the sqlite3_initialize() function.
5871 ** ^The xMutexInit routine is called by SQLite exactly once for each
5872 ** effective call to [sqlite3_initialize()].
5873 **
5874 ** ^The xMutexEnd method defined by this structure is invoked as
5875 ** part of system shutdown by the sqlite3_shutdown() function. The
5876 ** implementation of this method is expected to release all outstanding
5877 ** resources obtained by the mutex methods implementation, especially
5878 ** those obtained by the xMutexInit method. ^The xMutexEnd()
5879 ** interface is invoked exactly once for each call to [sqlite3_shutdown()].
5880 **
5881 ** ^(The remaining seven methods defined by this structure (xMutexAlloc,
5882 ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
5883 ** xMutexNotheld) implement the following interfaces (respectively):
5884 **
5885 ** <ul>
5886 ** <li> [sqlite3_mutex_alloc()] </li>
5887 ** <li> [sqlite3_mutex_free()] </li>
5888 ** <li> [sqlite3_mutex_enter()] </li>
5889 ** <li> [sqlite3_mutex_try()] </li>
5890 ** <li> [sqlite3_mutex_leave()] </li>
5891 ** <li> [sqlite3_mutex_held()] </li>
5892 ** <li> [sqlite3_mutex_notheld()] </li>
5893 ** </ul>)^
5894 **
5895 ** The only difference is that the public sqlite3_XXX functions enumerated
5896 ** above silently ignore any invocations that pass a NULL pointer instead
5897 ** of a valid mutex handle. The implementations of the methods defined
5898 ** by this structure are not required to handle this case, the results
5899 ** of passing a NULL pointer instead of a valid mutex handle are undefined
5900 ** (i.e. it is acceptable to provide an implementation that segfaults if
5901 ** it is passed a NULL pointer).
5902 **
5903 ** The xMutexInit() method must be threadsafe. ^It must be harmless to
5904 ** invoke xMutexInit() multiple times within the same process and without
5905 ** intervening calls to xMutexEnd(). Second and subsequent calls to
5906 ** xMutexInit() must be no-ops.
5907 **
5908 ** ^xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
5909 ** and its associates). ^Similarly, xMutexAlloc() must not use SQLite memory
5910 ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite
5911 ** memory allocation for a fast or recursive mutex.
5912 **
5913 ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
5914 ** called, but only if the prior call to xMutexInit returned SQLITE_OK.
5915 ** If xMutexInit fails in any way, it is expected to clean up after itself
5916 ** prior to returning.
5917 */
5919 struct sqlite3_mutex_methods {
5920  int (*xMutexInit)(void);
5921  int (*xMutexEnd)(void);
5922  sqlite3_mutex *(*xMutexAlloc)(int);
5923  void (*xMutexFree)(sqlite3_mutex *);
5924  void (*xMutexEnter)(sqlite3_mutex *);
5925  int (*xMutexTry)(sqlite3_mutex *);
5926  void (*xMutexLeave)(sqlite3_mutex *);
5927  int (*xMutexHeld)(sqlite3_mutex *);
5928  int (*xMutexNotheld)(sqlite3_mutex *);
5929 };
5930 
5931 /*
5932 ** CAPI3REF: Mutex Verification Routines
5933 **
5934 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
5935 ** are intended for use inside assert() statements. ^The SQLite core
5936 ** never uses these routines except inside an assert() and applications
5937 ** are advised to follow the lead of the core. ^The SQLite core only
5938 ** provides implementations for these routines when it is compiled
5939 ** with the SQLITE_DEBUG flag. ^External mutex implementations
5940 ** are only required to provide these routines if SQLITE_DEBUG is
5941 ** defined and if NDEBUG is not defined.
5942 **
5943 ** ^These routines should return true if the mutex in their argument
5944 ** is held or not held, respectively, by the calling thread.
5945 **
5946 ** ^The implementation is not required to provide versions of these
5947 ** routines that actually work. If the implementation does not provide working
5948 ** versions of these routines, it should at least provide stubs that always
5949 ** return true so that one does not get spurious assertion failures.
5950 **
5951 ** ^If the argument to sqlite3_mutex_held() is a NULL pointer then
5952 ** the routine should return 1. This seems counter-intuitive since
5953 ** clearly the mutex cannot be held if it does not exist. But
5954 ** the reason the mutex does not exist is because the build is not
5955 ** using mutexes. And we do not want the assert() containing the
5956 ** call to sqlite3_mutex_held() to fail, so a non-zero return is
5957 ** the appropriate thing to do. ^The sqlite3_mutex_notheld()
5958 ** interface should also return 1 when given a NULL pointer.
5959 */
5960 #ifndef NDEBUG
5963 #endif
5964 
5965 /*
5966 ** CAPI3REF: Mutex Types
5967 **
5968 ** The [sqlite3_mutex_alloc()] interface takes a single argument
5969 ** which is one of these integer constants.
5970 **
5971 ** The set of static mutexes may change from one SQLite release to the
5972 ** next. Applications that override the built-in mutex logic must be
5973 ** prepared to accommodate additional static mutexes.
5974 */
5975 #define SQLITE_MUTEX_FAST 0
5976 #define SQLITE_MUTEX_RECURSIVE 1
5977 #define SQLITE_MUTEX_STATIC_MASTER 2
5978 #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */
5979 #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */
5980 #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */
5981 #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */
5982 #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */
5983 #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */
5984 #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */
5985 
5986 /*
5987 ** CAPI3REF: Retrieve the mutex for a database connection
5988 **
5989 ** ^This interface returns a pointer the [sqlite3_mutex] object that
5990 ** serializes access to the [database connection] given in the argument
5991 ** when the [threading mode] is Serialized.
5992 ** ^If the [threading mode] is Single-thread or Multi-thread then this
5993 ** routine returns a NULL pointer.
5994 */
5996 
5997 /*
5998 ** CAPI3REF: Low-Level Control Of Database Files
5999 **
6000 ** ^The [sqlite3_file_control()] interface makes a direct call to the
6001 ** xFileControl method for the [sqlite3_io_methods] object associated
6002 ** with a particular database identified by the second argument. ^The
6003 ** name of the database is "main" for the main database or "temp" for the
6004 ** TEMP database, or the name that appears after the AS keyword for
6005 ** databases that are added using the [ATTACH] SQL command.
6006 ** ^A NULL pointer can be used in place of "main" to refer to the
6007 ** main database file.
6008 ** ^The third and fourth parameters to this routine
6009 ** are passed directly through to the second and third parameters of
6010 ** the xFileControl method. ^The return value of the xFileControl
6011 ** method becomes the return value of this routine.
6012 **
6013 ** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes
6014 ** a pointer to the underlying [sqlite3_file] object to be written into
6015 ** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER
6016 ** case is a short-circuit path which does not actually invoke the
6017 ** underlying sqlite3_io_methods.xFileControl method.
6018 **
6019 ** ^If the second parameter (zDbName) does not match the name of any
6020 ** open database file, then SQLITE_ERROR is returned. ^This error
6021 ** code is not remembered and will not be recalled by [sqlite3_errcode()]
6022 ** or [sqlite3_errmsg()]. The underlying xFileControl method might
6023 ** also return SQLITE_ERROR. There is no way to distinguish between
6024 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying
6025 ** xFileControl method.
6026 **
6027 ** See also: [SQLITE_FCNTL_LOCKSTATE]
6028 */
6029 SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);
6030 
6031 /*
6032 ** CAPI3REF: Testing Interface
6033 **
6034 ** ^The sqlite3_test_control() interface is used to read out internal
6035 ** state of SQLite and to inject faults into SQLite for testing
6036 ** purposes. ^The first parameter is an operation code that determines
6037 ** the number, meaning, and operation of all subsequent parameters.
6038 **
6039 ** This interface is not for use by applications. It exists solely
6040 ** for verifying the correct operation of the SQLite library. Depending
6041 ** on how the SQLite library is compiled, this interface might not exist.
6042 **
6043 ** The details of the operation codes, their meanings, the parameters
6044 ** they take, and what they do are all subject to change without notice.
6045 ** Unlike most of the SQLite API, this function is not guaranteed to
6046 ** operate consistently from one release to the next.
6047 */
6048 SQLITE_API int sqlite3_test_control(int op, ...);
6049 
6050 /*
6051 ** CAPI3REF: Testing Interface Operation Codes
6052 **
6053 ** These constants are the valid operation code parameters used
6054 ** as the first argument to [sqlite3_test_control()].
6055 **
6056 ** These parameters and their meanings are subject to change
6057 ** without notice. These values are for testing purposes only.
6058 ** Applications should not use any of these parameters or the
6059 ** [sqlite3_test_control()] interface.
6060 */
6061 #define SQLITE_TESTCTRL_FIRST 5
6062 #define SQLITE_TESTCTRL_PRNG_SAVE 5
6063 #define SQLITE_TESTCTRL_PRNG_RESTORE 6
6064 #define SQLITE_TESTCTRL_PRNG_RESET 7
6065 #define SQLITE_TESTCTRL_BITVEC_TEST 8
6066 #define SQLITE_TESTCTRL_FAULT_INSTALL 9
6067 #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10
6068 #define SQLITE_TESTCTRL_PENDING_BYTE 11
6069 #define SQLITE_TESTCTRL_ASSERT 12
6070 #define SQLITE_TESTCTRL_ALWAYS 13
6071 #define SQLITE_TESTCTRL_RESERVE 14
6072 #define SQLITE_TESTCTRL_OPTIMIZATIONS 15
6073 #define SQLITE_TESTCTRL_ISKEYWORD 16
6074 #define SQLITE_TESTCTRL_SCRATCHMALLOC 17
6075 #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18
6076 #define SQLITE_TESTCTRL_EXPLAIN_STMT 19
6077 #define SQLITE_TESTCTRL_NEVER_CORRUPT 20
6078 #define SQLITE_TESTCTRL_LAST 20
6079 
6080 /*
6081 ** CAPI3REF: SQLite Runtime Status
6082 **
6083 ** ^This interface is used to retrieve runtime status information
6084 ** about the performance of SQLite, and optionally to reset various
6085 ** highwater marks. ^The first argument is an integer code for
6086 ** the specific parameter to measure. ^(Recognized integer codes
6087 ** are of the form [status parameters | SQLITE_STATUS_...].)^
6088 ** ^The current value of the parameter is returned into *pCurrent.
6089 ** ^The highest recorded value is returned in *pHighwater. ^If the
6090 ** resetFlag is true, then the highest record value is reset after
6091 ** *pHighwater is written. ^(Some parameters do not record the highest
6092 ** value. For those parameters
6093 ** nothing is written into *pHighwater and the resetFlag is ignored.)^
6094 ** ^(Other parameters record only the highwater mark and not the current
6095 ** value. For these latter parameters nothing is written into *pCurrent.)^
6096 **
6097 ** ^The sqlite3_status() routine returns SQLITE_OK on success and a
6098 ** non-zero [error code] on failure.
6099 **
6100 ** This routine is threadsafe but is not atomic. This routine can be
6101 ** called while other threads are running the same or different SQLite
6102 ** interfaces. However the values returned in *pCurrent and
6103 ** *pHighwater reflect the status of SQLite at different points in time
6104 ** and it is possible that another thread might change the parameter
6105 ** in between the times when *pCurrent and *pHighwater are written.
6106 **
6107 ** See also: [sqlite3_db_status()]
6108 */
6109 SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);
6110 
6111 
6112 /*
6113 ** CAPI3REF: Status Parameters
6114 ** KEYWORDS: {status parameters}
6115 **
6116 ** These integer constants designate various run-time status parameters
6117 ** that can be returned by [sqlite3_status()].
6118 **
6119 ** <dl>
6120 ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt>
6121 ** <dd>This parameter is the current amount of memory checked out
6122 ** using [sqlite3_malloc()], either directly or indirectly. The
6123 ** figure includes calls made to [sqlite3_malloc()] by the application
6124 ** and internal memory usage by the SQLite library. Scratch memory
6125 ** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache
6126 ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
6127 ** this parameter. The amount returned is the sum of the allocation
6128 ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^
6129 **
6130 ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt>
6131 ** <dd>This parameter records the largest memory allocation request
6132 ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
6133 ** internal equivalents). Only the value returned in the
6134 ** *pHighwater parameter to [sqlite3_status()] is of interest.
6135 ** The value written into the *pCurrent parameter is undefined.</dd>)^
6136 **
6137 ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt>
6138 ** <dd>This parameter records the number of separate memory allocations
6139 ** currently checked out.</dd>)^
6140 **
6141 ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt>
6142 ** <dd>This parameter returns the number of pages used out of the
6143 ** [pagecache memory allocator] that was configured using
6144 ** [SQLITE_CONFIG_PAGECACHE]. The
6145 ** value returned is in pages, not in bytes.</dd>)^
6146 **
6147 ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]]
6148 ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>
6149 ** <dd>This parameter returns the number of bytes of page cache
6150 ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE]
6151 ** buffer and where forced to overflow to [sqlite3_malloc()]. The
6152 ** returned value includes allocations that overflowed because they
6153 ** where too large (they were larger than the "sz" parameter to
6154 ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
6155 ** no space was left in the page cache.</dd>)^
6156 **
6157 ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>
6158 ** <dd>This parameter records the largest memory allocation request
6159 ** handed to [pagecache memory allocator]. Only the value returned in the
6160 ** *pHighwater parameter to [sqlite3_status()] is of interest.
6161 ** The value written into the *pCurrent parameter is undefined.</dd>)^
6162 **
6163 ** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt>
6164 ** <dd>This parameter returns the number of allocations used out of the
6165 ** [scratch memory allocator] configured using
6166 ** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not
6167 ** in bytes. Since a single thread may only have one scratch allocation
6168 ** outstanding at time, this parameter also reports the number of threads
6169 ** using scratch memory at the same time.</dd>)^
6170 **
6171 ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>
6172 ** <dd>This parameter returns the number of bytes of scratch memory
6173 ** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH]
6174 ** buffer and where forced to overflow to [sqlite3_malloc()]. The values
6175 ** returned include overflows because the requested allocation was too
6176 ** larger (that is, because the requested allocation was larger than the
6177 ** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer
6178 ** slots were available.
6179 ** </dd>)^
6180 **
6181 ** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt>
6182 ** <dd>This parameter records the largest memory allocation request
6183 ** handed to [scratch memory allocator]. Only the value returned in the
6184 ** *pHighwater parameter to [sqlite3_status()] is of interest.
6185 ** The value written into the *pCurrent parameter is undefined.</dd>)^
6186 **
6187 ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt>
6188 ** <dd>This parameter records the deepest parser stack. It is only
6189 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
6190 ** </dl>
6191 **
6192 ** New status parameters may be added from time to time.
6193 */
6194 #define SQLITE_STATUS_MEMORY_USED 0
6195 #define SQLITE_STATUS_PAGECACHE_USED 1
6196 #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2
6197 #define SQLITE_STATUS_SCRATCH_USED 3
6198 #define SQLITE_STATUS_SCRATCH_OVERFLOW 4
6199 #define SQLITE_STATUS_MALLOC_SIZE 5
6200 #define SQLITE_STATUS_PARSER_STACK 6
6201 #define SQLITE_STATUS_PAGECACHE_SIZE 7
6202 #define SQLITE_STATUS_SCRATCH_SIZE 8
6203 #define SQLITE_STATUS_MALLOC_COUNT 9
6204 
6205 /*
6206 ** CAPI3REF: Database Connection Status
6207 **
6208 ** ^This interface is used to retrieve runtime status information
6209 ** about a single [database connection]. ^The first argument is the
6210 ** database connection object to be interrogated. ^The second argument
6211 ** is an integer constant, taken from the set of
6212 ** [SQLITE_DBSTATUS options], that
6213 ** determines the parameter to interrogate. The set of
6214 ** [SQLITE_DBSTATUS options] is likely
6215 ** to grow in future releases of SQLite.
6216 **
6217 ** ^The current value of the requested parameter is written into *pCur
6218 ** and the highest instantaneous value is written into *pHiwtr. ^If
6219 ** the resetFlg is true, then the highest instantaneous value is
6220 ** reset back down to the current value.
6221 **
6222 ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a
6223 ** non-zero [error code] on failure.
6224 **
6225 ** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
6226 */
6227 SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
6228 
6229 /*
6230 ** CAPI3REF: Status Parameters for database connections
6231 ** KEYWORDS: {SQLITE_DBSTATUS options}
6232 **
6233 ** These constants are the available integer "verbs" that can be passed as
6234 ** the second argument to the [sqlite3_db_status()] interface.
6235 **
6236 ** New verbs may be added in future releases of SQLite. Existing verbs
6237 ** might be discontinued. Applications should check the return code from
6238 ** [sqlite3_db_status()] to make sure that the call worked.
6239 ** The [sqlite3_db_status()] interface will return a non-zero error code
6240 ** if a discontinued or unsupported verb is invoked.
6241 **
6242 ** <dl>
6243 ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
6244 ** <dd>This parameter returns the number of lookaside memory slots currently
6245 ** checked out.</dd>)^
6246 **
6247 ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt>
6248 ** <dd>This parameter returns the number malloc attempts that were
6249 ** satisfied using lookaside memory. Only the high-water value is meaningful;
6250 ** the current value is always zero.)^
6251 **
6252 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]]
6253 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt>
6254 ** <dd>This parameter returns the number malloc attempts that might have
6255 ** been satisfied using lookaside memory but failed due to the amount of
6256 ** memory requested being larger than the lookaside slot size.
6257 ** Only the high-water value is meaningful;
6258 ** the current value is always zero.)^
6259 **
6260 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]]
6261 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt>
6262 ** <dd>This parameter returns the number malloc attempts that might have
6263 ** been satisfied using lookaside memory but failed due to all lookaside
6264 ** memory already being in use.
6265 ** Only the high-water value is meaningful;
6266 ** the current value is always zero.)^
6267 **
6268 ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt>
6269 ** <dd>This parameter returns the approximate number of of bytes of heap
6270 ** memory used by all pager caches associated with the database connection.)^
6271 ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
6272 **
6273 ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt>
6274 ** <dd>This parameter returns the approximate number of of bytes of heap
6275 ** memory used to store the schema for all databases associated
6276 ** with the connection - main, temp, and any [ATTACH]-ed databases.)^
6277 ** ^The full amount of memory used by the schemas is reported, even if the
6278 ** schema memory is shared with other database connections due to
6279 ** [shared cache mode] being enabled.
6280 ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.
6281 **
6282 ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt>
6283 ** <dd>This parameter returns the approximate number of of bytes of heap
6284 ** and lookaside memory used by all prepared statements associated with
6285 ** the database connection.)^
6286 ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
6287 ** </dd>
6288 **
6289 ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt>
6290 ** <dd>This parameter returns the number of pager cache hits that have
6291 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT
6292 ** is always 0.
6293 ** </dd>
6294 **
6295 ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt>
6296 ** <dd>This parameter returns the number of pager cache misses that have
6297 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS
6298 ** is always 0.
6299 ** </dd>
6300 **
6301 ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt>
6302 ** <dd>This parameter returns the number of dirty cache entries that have
6303 ** been written to disk. Specifically, the number of pages written to the
6304 ** wal file in wal mode databases, or the number of pages written to the
6305 ** database file in rollback mode databases. Any pages written as part of
6306 ** transaction rollback or database recovery operations are not included.
6307 ** If an IO or other error occurs while writing a page to disk, the effect
6308 ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The
6309 ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0.
6310 ** </dd>
6311 **
6312 ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt>
6313 ** <dd>This parameter returns zero for the current value if and only if
6314 ** all foreign key constraints (deferred or immediate) have been
6315 ** resolved.)^ ^The highwater mark is always 0.
6316 ** </dd>
6317 ** </dl>
6318 */
6319 #define SQLITE_DBSTATUS_LOOKASIDE_USED 0
6320 #define SQLITE_DBSTATUS_CACHE_USED 1
6321 #define SQLITE_DBSTATUS_SCHEMA_USED 2
6322 #define SQLITE_DBSTATUS_STMT_USED 3
6323 #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4
6324 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5
6325 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6
6326 #define SQLITE_DBSTATUS_CACHE_HIT 7
6327 #define SQLITE_DBSTATUS_CACHE_MISS 8
6328 #define SQLITE_DBSTATUS_CACHE_WRITE 9
6329 #define SQLITE_DBSTATUS_DEFERRED_FKS 10
6330 #define SQLITE_DBSTATUS_MAX 10 /* Largest defined DBSTATUS */
6331 
6332 
6333 /*
6334 ** CAPI3REF: Prepared Statement Status
6335 **
6336 ** ^(Each prepared statement maintains various
6337 ** [SQLITE_STMTSTATUS counters] that measure the number
6338 ** of times it has performed specific operations.)^ These counters can
6339 ** be used to monitor the performance characteristics of the prepared
6340 ** statements. For example, if the number of table steps greatly exceeds
6341 ** the number of table searches or result rows, that would tend to indicate
6342 ** that the prepared statement is using a full table scan rather than
6343 ** an index.
6344 **
6345 ** ^(This interface is used to retrieve and reset counter values from
6346 ** a [prepared statement]. The first argument is the prepared statement
6347 ** object to be interrogated. The second argument
6348 ** is an integer code for a specific [SQLITE_STMTSTATUS counter]
6349 ** to be interrogated.)^
6350 ** ^The current value of the requested counter is returned.
6351 ** ^If the resetFlg is true, then the counter is reset to zero after this
6352 ** interface call returns.
6353 **
6354 ** See also: [sqlite3_status()] and [sqlite3_db_status()].
6355 */
6356 SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
6357 
6358 /*
6359 ** CAPI3REF: Status Parameters for prepared statements
6360 ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters}
6361 **
6362 ** These preprocessor macros define integer codes that name counter
6363 ** values associated with the [sqlite3_stmt_status()] interface.
6364 ** The meanings of the various counters are as follows:
6365 **
6366 ** <dl>
6367 ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt>
6368 ** <dd>^This is the number of times that SQLite has stepped forward in
6369 ** a table as part of a full table scan. Large numbers for this counter
6370 ** may indicate opportunities for performance improvement through
6371 ** careful use of indices.</dd>
6372 **
6373 ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt>
6374 ** <dd>^This is the number of sort operations that have occurred.
6375 ** A non-zero value in this counter may indicate an opportunity to
6376 ** improvement performance through careful use of indices.</dd>
6377 **
6378 ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt>
6379 ** <dd>^This is the number of rows inserted into transient indices that
6380 ** were created automatically in order to help joins run faster.
6381 ** A non-zero value in this counter may indicate an opportunity to
6382 ** improvement performance by adding permanent indices that do not
6383 ** need to be reinitialized each time the statement is run.</dd>
6384 **
6385 ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt>
6386 ** <dd>^This is the number of virtual machine operations executed
6387 ** by the prepared statement if that number is less than or equal
6388 ** to 2147483647. The number of virtual machine operations can be
6389 ** used as a proxy for the total work done by the prepared statement.
6390 ** If the number of virtual machine operations exceeds 2147483647
6391 ** then the value returned by this statement status code is undefined.
6392 ** </dd>
6393 ** </dl>
6394 */
6395 #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1
6396 #define SQLITE_STMTSTATUS_SORT 2
6397 #define SQLITE_STMTSTATUS_AUTOINDEX 3
6398 #define SQLITE_STMTSTATUS_VM_STEP 4
6399 
6400 /*
6401 ** CAPI3REF: Custom Page Cache Object
6402 **
6403 ** The sqlite3_pcache type is opaque. It is implemented by
6404 ** the pluggable module. The SQLite core has no knowledge of
6405 ** its size or internal structure and never deals with the
6406 ** sqlite3_pcache object except by holding and passing pointers
6407 ** to the object.
6408 **
6409 ** See [sqlite3_pcache_methods2] for additional information.
6410 */
6412 
6413 /*
6414 ** CAPI3REF: Custom Page Cache Object
6415 **
6416 ** The sqlite3_pcache_page object represents a single page in the
6417 ** page cache. The page cache will allocate instances of this
6418 ** object. Various methods of the page cache use pointers to instances
6419 ** of this object as parameters or as their return value.
6420 **
6421 ** See [sqlite3_pcache_methods2] for additional information.
6422 */
6424 struct sqlite3_pcache_page {
6425  void *pBuf; /* The content of the page */
6426  void *pExtra; /* Extra information associated with the page */
6427 };
6428 
6429 /*
6430 ** CAPI3REF: Application Defined Page Cache.
6431 ** KEYWORDS: {page cache}
6432 **
6433 ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can
6434 ** register an alternative page cache implementation by passing in an
6435 ** instance of the sqlite3_pcache_methods2 structure.)^
6436 ** In many applications, most of the heap memory allocated by
6437 ** SQLite is used for the page cache.
6438 ** By implementing a
6439 ** custom page cache using this API, an application can better control
6440 ** the amount of memory consumed by SQLite, the way in which
6441 ** that memory is allocated and released, and the policies used to
6442 ** determine exactly which parts of a database file are cached and for
6443 ** how long.
6444 **
6445 ** The alternative page cache mechanism is an
6446 ** extreme measure that is only needed by the most demanding applications.
6447 ** The built-in page cache is recommended for most uses.
6448 **
6449 ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an
6450 ** internal buffer by SQLite within the call to [sqlite3_config]. Hence
6451 ** the application may discard the parameter after the call to
6452 ** [sqlite3_config()] returns.)^
6453 **
6454 ** [[the xInit() page cache method]]
6455 ** ^(The xInit() method is called once for each effective
6456 ** call to [sqlite3_initialize()])^
6457 ** (usually only once during the lifetime of the process). ^(The xInit()
6458 ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^
6459 ** The intent of the xInit() method is to set up global data structures
6460 ** required by the custom page cache implementation.
6461 ** ^(If the xInit() method is NULL, then the
6462 ** built-in default page cache is used instead of the application defined
6463 ** page cache.)^
6464 **
6465 ** [[the xShutdown() page cache method]]
6466 ** ^The xShutdown() method is called by [sqlite3_shutdown()].
6467 ** It can be used to clean up
6468 ** any outstanding resources before process shutdown, if required.
6469 ** ^The xShutdown() method may be NULL.
6470 **
6471 ** ^SQLite automatically serializes calls to the xInit method,
6472 ** so the xInit method need not be threadsafe. ^The
6473 ** xShutdown method is only called from [sqlite3_shutdown()] so it does
6474 ** not need to be threadsafe either. All other methods must be threadsafe
6475 ** in multithreaded applications.
6476 **
6477 ** ^SQLite will never invoke xInit() more than once without an intervening
6478 ** call to xShutdown().
6479 **
6480 ** [[the xCreate() page cache methods]]
6481 ** ^SQLite invokes the xCreate() method to construct a new cache instance.
6482 ** SQLite will typically create one cache instance for each open database file,
6483 ** though this is not guaranteed. ^The
6484 ** first parameter, szPage, is the size in bytes of the pages that must
6485 ** be allocated by the cache. ^szPage will always a power of two. ^The
6486 ** second parameter szExtra is a number of bytes of extra storage
6487 ** associated with each page cache entry. ^The szExtra parameter will
6488 ** a number less than 250. SQLite will use the
6489 ** extra szExtra bytes on each page to store metadata about the underlying
6490 ** database page on disk. The value passed into szExtra depends
6491 ** on the SQLite version, the target platform, and how SQLite was compiled.
6492 ** ^The third argument to xCreate(), bPurgeable, is true if the cache being
6493 ** created will be used to cache database pages of a file stored on disk, or
6494 ** false if it is used for an in-memory database. The cache implementation
6495 ** does not have to do anything special based with the value of bPurgeable;
6496 ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will
6497 ** never invoke xUnpin() except to deliberately delete a page.
6498 ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to
6499 ** false will always have the "discard" flag set to true.
6500 ** ^Hence, a cache created with bPurgeable false will
6501 ** never contain any unpinned pages.
6502 **
6503 ** [[the xCachesize() page cache method]]
6504 ** ^(The xCachesize() method may be called at any time by SQLite to set the
6505 ** suggested maximum cache-size (number of pages stored by) the cache
6506 ** instance passed as the first argument. This is the value configured using
6507 ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable
6508 ** parameter, the implementation is not required to do anything with this
6509 ** value; it is advisory only.
6510 **
6511 ** [[the xPagecount() page cache methods]]
6512 ** The xPagecount() method must return the number of pages currently
6513 ** stored in the cache, both pinned and unpinned.
6514 **
6515 ** [[the xFetch() page cache methods]]
6516 ** The xFetch() method locates a page in the cache and returns a pointer to
6517 ** an sqlite3_pcache_page object associated with that page, or a NULL pointer.
6518 ** The pBuf element of the returned sqlite3_pcache_page object will be a
6519 ** pointer to a buffer of szPage bytes used to store the content of a
6520 ** single database page. The pExtra element of sqlite3_pcache_page will be
6521 ** a pointer to the szExtra bytes of extra storage that SQLite has requested
6522 ** for each entry in the page cache.
6523 **
6524 ** The page to be fetched is determined by the key. ^The minimum key value
6525 ** is 1. After it has been retrieved using xFetch, the page is considered
6526 ** to be "pinned".
6527 **
6528 ** If the requested page is already in the page cache, then the page cache
6529 ** implementation must return a pointer to the page buffer with its content
6530 ** intact. If the requested page is not already in the cache, then the
6531 ** cache implementation should use the value of the createFlag
6532 ** parameter to help it determined what action to take:
6533 **
6534 ** <table border=1 width=85% align=center>
6535 ** <tr><th> createFlag <th> Behavior when page is not already in cache
6536 ** <tr><td> 0 <td> Do not allocate a new page. Return NULL.
6537 ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so.
6538 ** Otherwise return NULL.
6539 ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return
6540 ** NULL if allocating a new page is effectively impossible.
6541 ** </table>
6542 **
6543 ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite
6544 ** will only use a createFlag of 2 after a prior call with a createFlag of 1
6545 ** failed.)^ In between the to xFetch() calls, SQLite may
6546 ** attempt to unpin one or more cache pages by spilling the content of
6547 ** pinned pages to disk and synching the operating system disk cache.
6548 **
6549 ** [[the xUnpin() page cache method]]
6550 ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page
6551 ** as its second argument. If the third parameter, discard, is non-zero,
6552 ** then the page must be evicted from the cache.
6553 ** ^If the discard parameter is
6554 ** zero, then the page may be discarded or retained at the discretion of
6555 ** page cache implementation. ^The page cache implementation
6556 ** may choose to evict unpinned pages at any time.
6557 **
6558 ** The cache must not perform any reference counting. A single
6559 ** call to xUnpin() unpins the page regardless of the number of prior calls
6560 ** to xFetch().
6561 **
6562 ** [[the xRekey() page cache methods]]
6563 ** The xRekey() method is used to change the key value associated with the
6564 ** page passed as the second argument. If the cache
6565 ** previously contains an entry associated with newKey, it must be
6566 ** discarded. ^Any prior cache entry associated with newKey is guaranteed not
6567 ** to be pinned.
6568 **
6569 ** When SQLite calls the xTruncate() method, the cache must discard all
6570 ** existing cache entries with page numbers (keys) greater than or equal
6571 ** to the value of the iLimit parameter passed to xTruncate(). If any
6572 ** of these pages are pinned, they are implicitly unpinned, meaning that
6573 ** they can be safely discarded.
6574 **
6575 ** [[the xDestroy() page cache method]]
6576 ** ^The xDestroy() method is used to delete a cache allocated by xCreate().
6577 ** All resources associated with the specified cache should be freed. ^After
6578 ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
6579 ** handle invalid, and will not use it with any other sqlite3_pcache_methods2
6580 ** functions.
6581 **
6582 ** [[the xShrink() page cache method]]
6583 ** ^SQLite invokes the xShrink() method when it wants the page cache to
6584 ** free up as much of heap memory as possible. The page cache implementation
6585 ** is not obligated to free any memory, but well-behaved implementations should
6586 ** do their best.
6587 */
6589 struct sqlite3_pcache_methods2 {
6590  int iVersion;
6591  void *pArg;
6592  int (*xInit)(void*);
6593  void (*xShutdown)(void*);
6594  sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable);
6595  void (*xCachesize)(sqlite3_pcache*, int nCachesize);
6596  int (*xPagecount)(sqlite3_pcache*);
6597  sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
6598  void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard);
6599  void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*,
6600  unsigned oldKey, unsigned newKey);
6601  void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
6602  void (*xDestroy)(sqlite3_pcache*);
6603  void (*xShrink)(sqlite3_pcache*);
6604 };
6605 
6606 /*
6607 ** This is the obsolete pcache_methods object that has now been replaced
6608 ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is
6609 ** retained in the header file for backwards compatibility only.
6610 */
6612 struct sqlite3_pcache_methods {
6613  void *pArg;
6614  int (*xInit)(void*);
6615  void (*xShutdown)(void*);
6616  sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable);
6617  void (*xCachesize)(sqlite3_pcache*, int nCachesize);
6618  int (*xPagecount)(sqlite3_pcache*);
6619  void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
6620  void (*xUnpin)(sqlite3_pcache*, void*, int discard);
6621  void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey);
6622  void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
6623  void (*xDestroy)(sqlite3_pcache*);
6624 };
6625 
6626 
6627 /*
6628 ** CAPI3REF: Online Backup Object
6629 **
6630 ** The sqlite3_backup object records state information about an ongoing
6631 ** online backup operation. ^The sqlite3_backup object is created by
6632 ** a call to [sqlite3_backup_init()] and is destroyed by a call to
6633 ** [sqlite3_backup_finish()].
6634 **
6635 ** See Also: [Using the SQLite Online Backup API]
6636 */
6638 
6639 /*
6640 ** CAPI3REF: Online Backup API.
6641 **
6642 ** The backup API copies the content of one database into another.
6643 ** It is useful either for creating backups of databases or
6644 ** for copying in-memory databases to or from persistent files.
6645 **
6646 ** See Also: [Using the SQLite Online Backup API]
6647 **
6648 ** ^SQLite holds a write transaction open on the destination database file
6649 ** for the duration of the backup operation.
6650 ** ^The source database is read-locked only while it is being read;
6651 ** it is not locked continuously for the entire backup operation.
6652 ** ^Thus, the backup may be performed on a live source database without
6653 ** preventing other database connections from
6654 ** reading or writing to the source database while the backup is underway.
6655 **
6656 ** ^(To perform a backup operation:
6657 ** <ol>
6658 ** <li><b>sqlite3_backup_init()</b> is called once to initialize the
6659 ** backup,
6660 ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer
6661 ** the data between the two databases, and finally
6662 ** <li><b>sqlite3_backup_finish()</b> is called to release all resources
6663 ** associated with the backup operation.
6664 ** </ol>)^
6665 ** There should be exactly one call to sqlite3_backup_finish() for each
6666 ** successful call to sqlite3_backup_init().
6667 **
6668 ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b>
6669 **
6670 ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the
6671 ** [database connection] associated with the destination database
6672 ** and the database name, respectively.
6673 ** ^The database name is "main" for the main database, "temp" for the
6674 ** temporary database, or the name specified after the AS keyword in
6675 ** an [ATTACH] statement for an attached database.
6676 ** ^The S and M arguments passed to
6677 ** sqlite3_backup_init(D,N,S,M) identify the [database connection]
6678 ** and database name of the source database, respectively.
6679 ** ^The source and destination [database connections] (parameters S and D)
6680 ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
6681 ** an error.
6682 **
6683 ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
6684 ** returned and an error code and error message are stored in the
6685 ** destination [database connection] D.
6686 ** ^The error code and message for the failed call to sqlite3_backup_init()
6687 ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
6688 ** [sqlite3_errmsg16()] functions.
6689 ** ^A successful call to sqlite3_backup_init() returns a pointer to an
6690 ** [sqlite3_backup] object.
6691 ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and
6692 ** sqlite3_backup_finish() functions to perform the specified backup
6693 ** operation.
6694 **
6695 ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b>
6696 **
6697 ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between
6698 ** the source and destination databases specified by [sqlite3_backup] object B.
6699 ** ^If N is negative, all remaining source pages are copied.
6700 ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there
6701 ** are still more pages to be copied, then the function returns [SQLITE_OK].
6702 ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages
6703 ** from source to destination, then it returns [SQLITE_DONE].
6704 ** ^If an error occurs while running sqlite3_backup_step(B,N),
6705 ** then an [error code] is returned. ^As well as [SQLITE_OK] and
6706 ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
6707 ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an
6708 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
6709 **
6710 ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if
6711 ** <ol>
6712 ** <li> the destination database was opened read-only, or
6713 ** <li> the destination database is using write-ahead-log journaling
6714 ** and the destination and source page sizes differ, or
6715 ** <li> the destination database is an in-memory database and the
6716 ** destination and source page sizes differ.
6717 ** </ol>)^
6718 **
6719 ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then
6720 ** the [sqlite3_busy_handler | busy-handler function]
6721 ** is invoked (if one is specified). ^If the
6722 ** busy-handler returns non-zero before the lock is available, then
6723 ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to
6724 ** sqlite3_backup_step() can be retried later. ^If the source
6725 ** [database connection]
6726 ** is being used to write to the source database when sqlite3_backup_step()
6727 ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this
6728 ** case the call to sqlite3_backup_step() can be retried later on. ^(If
6729 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or
6730 ** [SQLITE_READONLY] is returned, then
6731 ** there is no point in retrying the call to sqlite3_backup_step(). These
6732 ** errors are considered fatal.)^ The application must accept
6733 ** that the backup operation has failed and pass the backup operation handle
6734 ** to the sqlite3_backup_finish() to release associated resources.
6735 **
6736 ** ^The first call to sqlite3_backup_step() obtains an exclusive lock
6737 ** on the destination file. ^The exclusive lock is not released until either
6738 ** sqlite3_backup_finish() is called or the backup operation is complete
6739 ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to
6740 ** sqlite3_backup_step() obtains a [shared lock] on the source database that
6741 ** lasts for the duration of the sqlite3_backup_step() call.
6742 ** ^Because the source database is not locked between calls to
6743 ** sqlite3_backup_step(), the source database may be modified mid-way
6744 ** through the backup process. ^If the source database is modified by an
6745 ** external process or via a database connection other than the one being
6746 ** used by the backup operation, then the backup will be automatically
6747 ** restarted by the next call to sqlite3_backup_step(). ^If the source
6748 ** database is modified by the using the same database connection as is used
6749 ** by the backup operation, then the backup database is automatically
6750 ** updated at the same time.
6751 **
6752 ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b>
6753 **
6754 ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the
6755 ** application wishes to abandon the backup operation, the application
6756 ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish().
6757 ** ^The sqlite3_backup_finish() interfaces releases all
6758 ** resources associated with the [sqlite3_backup] object.
6759 ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any
6760 ** active write-transaction on the destination database is rolled back.
6761 ** The [sqlite3_backup] object is invalid
6762 ** and may not be used following a call to sqlite3_backup_finish().
6763 **
6764 ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no
6765 ** sqlite3_backup_step() errors occurred, regardless or whether or not
6766 ** sqlite3_backup_step() completed.
6767 ** ^If an out-of-memory condition or IO error occurred during any prior
6768 ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then
6769 ** sqlite3_backup_finish() returns the corresponding [error code].
6770 **
6771 ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step()
6772 ** is not a permanent error and does not affect the return value of
6773 ** sqlite3_backup_finish().
6774 **
6775 ** [[sqlite3_backup__remaining()]] [[sqlite3_backup_pagecount()]]
6776 ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b>
6777 **
6778 ** ^Each call to sqlite3_backup_step() sets two values inside
6779 ** the [sqlite3_backup] object: the number of pages still to be backed
6780 ** up and the total number of pages in the source database file.
6781 ** The sqlite3_backup_remaining() and sqlite3_backup_pagecount() interfaces
6782 ** retrieve these two values, respectively.
6783 **
6784 ** ^The values returned by these functions are only updated by
6785 ** sqlite3_backup_step(). ^If the source database is modified during a backup
6786 ** operation, then the values are not updated to account for any extra
6787 ** pages that need to be updated or the size of the source database file
6788 ** changing.
6789 **
6790 ** <b>Concurrent Usage of Database Handles</b>
6791 **
6792 ** ^The source [database connection] may be used by the application for other
6793 ** purposes while a backup operation is underway or being initialized.
6794 ** ^If SQLite is compiled and configured to support threadsafe database
6795 ** connections, then the source database connection may be used concurrently
6796 ** from within other threads.
6797 **
6798 ** However, the application must guarantee that the destination
6799 ** [database connection] is not passed to any other API (by any thread) after
6800 ** sqlite3_backup_init() is called and before the corresponding call to
6801 ** sqlite3_backup_finish(). SQLite does not currently check to see
6802 ** if the application incorrectly accesses the destination [database connection]
6803 ** and so no error code is reported, but the operations may malfunction
6804 ** nevertheless. Use of the destination database connection while a
6805 ** backup is in progress might also also cause a mutex deadlock.
6806 **
6807 ** If running in [shared cache mode], the application must
6808 ** guarantee that the shared cache used by the destination database
6809 ** is not accessed while the backup is running. In practice this means
6810 ** that the application must guarantee that the disk file being
6811 ** backed up to is not accessed by any connection within the process,
6812 ** not just the specific connection that was passed to sqlite3_backup_init().
6813 **
6814 ** The [sqlite3_backup] object itself is partially threadsafe. Multiple
6815 ** threads may safely make multiple concurrent calls to sqlite3_backup_step().
6816 ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()
6817 ** APIs are not strictly speaking threadsafe. If they are invoked at the
6818 ** same time as another thread is invoking sqlite3_backup_step() it is
6819 ** possible that they return invalid values.
6820 */
6822  sqlite3 *pDest, /* Destination database handle */
6823  const char *zDestName, /* Destination database name */
6824  sqlite3 *pSource, /* Source database handle */
6825  const char *zSourceName /* Source database name */
6826 );
6827 SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage);
6831 
6832 /*
6833 ** CAPI3REF: Unlock Notification
6834 **
6835 ** ^When running in shared-cache mode, a database operation may fail with
6836 ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
6837 ** individual tables within the shared-cache cannot be obtained. See
6838 ** [SQLite Shared-Cache Mode] for a description of shared-cache locking.
6839 ** ^This API may be used to register a callback that SQLite will invoke
6840 ** when the connection currently holding the required lock relinquishes it.
6841 ** ^This API is only available if the library was compiled with the
6842 ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.
6843 **
6844 ** See Also: [Using the SQLite Unlock Notification Feature].
6845 **
6846 ** ^Shared-cache locks are released when a database connection concludes
6847 ** its current transaction, either by committing it or rolling it back.
6848 **
6849 ** ^When a connection (known as the blocked connection) fails to obtain a
6850 ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the
6851 ** identity of the database connection (the blocking connection) that
6852 ** has locked the required resource is stored internally. ^After an
6853 ** application receives an SQLITE_LOCKED error, it may call the
6854 ** sqlite3_unlock_notify() method with the blocked connection handle as
6855 ** the first argument to register for a callback that will be invoked
6856 ** when the blocking connections current transaction is concluded. ^The
6857 ** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
6858 ** call that concludes the blocking connections transaction.
6859 **
6860 ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application,
6861 ** there is a chance that the blocking connection will have already
6862 ** concluded its transaction by the time sqlite3_unlock_notify() is invoked.
6863 ** If this happens, then the specified callback is invoked immediately,
6864 ** from within the call to sqlite3_unlock_notify().)^
6865 **
6866 ** ^If the blocked connection is attempting to obtain a write-lock on a
6867 ** shared-cache table, and more than one other connection currently holds
6868 ** a read-lock on the same table, then SQLite arbitrarily selects one of
6869 ** the other connections to use as the blocking connection.
6870 **
6871 ** ^(There may be at most one unlock-notify callback registered by a
6872 ** blocked connection. If sqlite3_unlock_notify() is called when the
6873 ** blocked connection already has a registered unlock-notify callback,
6874 ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is
6875 ** called with a NULL pointer as its second argument, then any existing
6876 ** unlock-notify callback is canceled. ^The blocked connections
6877 ** unlock-notify callback may also be canceled by closing the blocked
6878 ** connection using [sqlite3_close()].
6879 **
6880 ** The unlock-notify callback is not reentrant. If an application invokes
6881 ** any sqlite3_xxx API functions from within an unlock-notify callback, a
6882 ** crash or deadlock may be the result.
6883 **
6884 ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always
6885 ** returns SQLITE_OK.
6886 **
6887 ** <b>Callback Invocation Details</b>
6888 **
6889 ** When an unlock-notify callback is registered, the application provides a
6890 ** single void* pointer that is passed to the callback when it is invoked.
6891 ** However, the signature of the callback function allows SQLite to pass
6892 ** it an array of void* context pointers. The first argument passed to
6893 ** an unlock-notify callback is a pointer to an array of void* pointers,
6894 ** and the second is the number of entries in the array.
6895 **
6896 ** When a blocking connections transaction is concluded, there may be
6897 ** more than one blocked connection that has registered for an unlock-notify
6898 ** callback. ^If two or more such blocked connections have specified the
6899 ** same callback function, then instead of invoking the callback function
6900 ** multiple times, it is invoked once with the set of void* context pointers
6901 ** specified by the blocked connections bundled together into an array.
6902 ** This gives the application an opportunity to prioritize any actions
6903 ** related to the set of unblocked database connections.
6904 **
6905 ** <b>Deadlock Detection</b>
6906 **
6907 ** Assuming that after registering for an unlock-notify callback a
6908 ** database waits for the callback to be issued before taking any further
6909 ** action (a reasonable assumption), then using this API may cause the
6910 ** application to deadlock. For example, if connection X is waiting for
6911 ** connection Y's transaction to be concluded, and similarly connection
6912 ** Y is waiting on connection X's transaction, then neither connection
6913 ** will proceed and the system may remain deadlocked indefinitely.
6914 **
6915 ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock
6916 ** detection. ^If a given call to sqlite3_unlock_notify() would put the
6917 ** system in a deadlocked state, then SQLITE_LOCKED is returned and no
6918 ** unlock-notify callback is registered. The system is said to be in
6919 ** a deadlocked state if connection A has registered for an unlock-notify
6920 ** callback on the conclusion of connection B's transaction, and connection
6921 ** B has itself registered for an unlock-notify callback when connection
6922 ** A's transaction is concluded. ^Indirect deadlock is also detected, so
6923 ** the system is also considered to be deadlocked if connection B has
6924 ** registered for an unlock-notify callback on the conclusion of connection
6925 ** C's transaction, where connection C is waiting on connection A. ^Any
6926 ** number of levels of indirection are allowed.
6927 **
6928 ** <b>The "DROP TABLE" Exception</b>
6929 **
6930 ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost
6931 ** always appropriate to call sqlite3_unlock_notify(). There is however,
6932 ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,
6933 ** SQLite checks if there are any currently executing SELECT statements
6934 ** that belong to the same connection. If there are, SQLITE_LOCKED is
6935 ** returned. In this case there is no "blocking connection", so invoking
6936 ** sqlite3_unlock_notify() results in the unlock-notify callback being
6937 ** invoked immediately. If the application then re-attempts the "DROP TABLE"
6938 ** or "DROP INDEX" query, an infinite loop might be the result.
6939 **
6940 ** One way around this problem is to check the extended error code returned
6941 ** by an sqlite3_step() call. ^(If there is a blocking connection, then the
6942 ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in
6943 ** the special "DROP TABLE/INDEX" case, the extended error code is just
6944 ** SQLITE_LOCKED.)^
6945 */
6947  sqlite3 *pBlocked, /* Waiting connection */
6948  void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */
6949  void *pNotifyArg /* Argument to pass to xNotify */
6950 );
6951 
6952 
6953 /*
6954 ** CAPI3REF: String Comparison
6955 **
6956 ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications
6957 ** and extensions to compare the contents of two buffers containing UTF-8
6958 ** strings in a case-independent fashion, using the same definition of "case
6959 ** independence" that SQLite uses internally when comparing identifiers.
6960 */
6961 SQLITE_API int sqlite3_stricmp(const char *, const char *);
6962 SQLITE_API int sqlite3_strnicmp(const char *, const char *, int);
6963 
6964 /*
6965 ** CAPI3REF: String Globbing
6966 *
6967 ** ^The [sqlite3_strglob(P,X)] interface returns zero if string X matches
6968 ** the glob pattern P, and it returns non-zero if string X does not match
6969 ** the glob pattern P. ^The definition of glob pattern matching used in
6970 ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the
6971 ** SQL dialect used by SQLite. ^The sqlite3_strglob(P,X) function is case
6972 ** sensitive.
6973 **
6974 ** Note that this routine returns zero on a match and non-zero if the strings
6975 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
6976 */
6977 SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr);
6978 
6979 /*
6980 ** CAPI3REF: Error Logging Interface
6981 **
6982 ** ^The [sqlite3_log()] interface writes a message into the [error log]
6983 ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
6984 ** ^If logging is enabled, the zFormat string and subsequent arguments are
6985 ** used with [sqlite3_snprintf()] to generate the final output string.
6986 **
6987 ** The sqlite3_log() interface is intended for use by extensions such as
6988 ** virtual tables, collating functions, and SQL functions. While there is
6989 ** nothing to prevent an application from calling sqlite3_log(), doing so
6990 ** is considered bad form.
6991 **
6992 ** The zFormat string must not be NULL.
6993 **
6994 ** To avoid deadlocks and other threading problems, the sqlite3_log() routine
6995 ** will not use dynamically allocated memory. The log message is stored in
6996 ** a fixed-length buffer on the stack. If the log message is longer than
6997 ** a few hundred characters, it will be truncated to the length of the
6998 ** buffer.
6999 */
7000 SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...);
7001 
7002 /*
7003 ** CAPI3REF: Write-Ahead Log Commit Hook
7004 **
7005 ** ^The [sqlite3_wal_hook()] function is used to register a callback that
7006 ** will be invoked each time a database connection commits data to a
7007 ** [write-ahead log] (i.e. whenever a transaction is committed in
7008 ** [journal_mode | journal_mode=WAL mode]).
7009 **
7010 ** ^The callback is invoked by SQLite after the commit has taken place and
7011 ** the associated write-lock on the database released, so the implementation
7012 ** may read, write or [checkpoint] the database as required.
7013 **
7014 ** ^The first parameter passed to the callback function when it is invoked
7015 ** is a copy of the third parameter passed to sqlite3_wal_hook() when
7016 ** registering the callback. ^The second is a copy of the database handle.
7017 ** ^The third parameter is the name of the database that was written to -
7018 ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter
7019 ** is the number of pages currently in the write-ahead log file,
7020 ** including those that were just committed.
7021 **
7022 ** The callback function should normally return [SQLITE_OK]. ^If an error
7023 ** code is returned, that error will propagate back up through the
7024 ** SQLite code base to cause the statement that provoked the callback
7025 ** to report an error, though the commit will have still occurred. If the
7026 ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value
7027 ** that does not correspond to any valid SQLite error code, the results
7028 ** are undefined.
7029 **
7030 ** A single database handle may have at most a single write-ahead log callback
7031 ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any
7032 ** previously registered write-ahead log callback. ^Note that the
7033 ** [sqlite3_wal_autocheckpoint()] interface and the
7034 ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will
7035 ** those overwrite any prior [sqlite3_wal_hook()] settings.
7036 */
7038  sqlite3*,
7039  int(*)(void *,sqlite3*,const char*,int),
7040  void*
7041 );
7042 
7043 /*
7044 ** CAPI3REF: Configure an auto-checkpoint
7045 **
7046 ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around
7047 ** [sqlite3_wal_hook()] that causes any database on [database connection] D
7048 ** to automatically [checkpoint]
7049 ** after committing a transaction if there are N or
7050 ** more frames in the [write-ahead log] file. ^Passing zero or
7051 ** a negative value as the nFrame parameter disables automatic
7052 ** checkpoints entirely.
7053 **
7054 ** ^The callback registered by this function replaces any existing callback
7055 ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback
7056 ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism
7057 ** configured by this function.
7058 **
7059 ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface
7060 ** from SQL.
7061 **
7062 ** ^Every new [database connection] defaults to having the auto-checkpoint
7063 ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT]
7064 ** pages. The use of this interface
7065 ** is only necessary if the default setting is found to be suboptimal
7066 ** for a particular application.
7067 */
7069 
7070 /*
7071 ** CAPI3REF: Checkpoint a database
7072 **
7073 ** ^The [sqlite3_wal_checkpoint(D,X)] interface causes database named X
7074 ** on [database connection] D to be [checkpointed]. ^If X is NULL or an
7075 ** empty string, then a checkpoint is run on all databases of
7076 ** connection D. ^If the database connection D is not in
7077 ** [WAL | write-ahead log mode] then this interface is a harmless no-op.
7078 **
7079 ** ^The [wal_checkpoint pragma] can be used to invoke this interface
7080 ** from SQL. ^The [sqlite3_wal_autocheckpoint()] interface and the
7081 ** [wal_autocheckpoint pragma] can be used to cause this interface to be
7082 ** run whenever the WAL reaches a certain size threshold.
7083 **
7084 ** See also: [sqlite3_wal_checkpoint_v2()]
7085 */
7086 SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb);
7087 
7088 /*
7089 ** CAPI3REF: Checkpoint a database
7090 **
7091 ** Run a checkpoint operation on WAL database zDb attached to database
7092 ** handle db. The specific operation is determined by the value of the
7093 ** eMode parameter:
7094 **
7095 ** <dl>
7096 ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd>
7097 ** Checkpoint as many frames as possible without waiting for any database
7098 ** readers or writers to finish. Sync the db file if all frames in the log
7099 ** are checkpointed. This mode is the same as calling
7100 ** sqlite3_wal_checkpoint(). The busy-handler callback is never invoked.
7101 **
7102 ** <dt>SQLITE_CHECKPOINT_FULL<dd>
7103 ** This mode blocks (calls the busy-handler callback) until there is no
7104 ** database writer and all readers are reading from the most recent database
7105 ** snapshot. It then checkpoints all frames in the log file and syncs the
7106 ** database file. This call blocks database writers while it is running,
7107 ** but not database readers.
7108 **
7109 ** <dt>SQLITE_CHECKPOINT_RESTART<dd>
7110 ** This mode works the same way as SQLITE_CHECKPOINT_FULL, except after
7111 ** checkpointing the log file it blocks (calls the busy-handler callback)
7112 ** until all readers are reading from the database file only. This ensures
7113 ** that the next client to write to the database file restarts the log file
7114 ** from the beginning. This call blocks database writers while it is running,
7115 ** but not database readers.
7116 ** </dl>
7117 **
7118 ** If pnLog is not NULL, then *pnLog is set to the total number of frames in
7119 ** the log file before returning. If pnCkpt is not NULL, then *pnCkpt is set to
7120 ** the total number of checkpointed frames (including any that were already
7121 ** checkpointed when this function is called). *pnLog and *pnCkpt may be
7122 ** populated even if sqlite3_wal_checkpoint_v2() returns other than SQLITE_OK.
7123 ** If no values are available because of an error, they are both set to -1
7124 ** before returning to communicate this to the caller.
7125 **
7126 ** All calls obtain an exclusive "checkpoint" lock on the database file. If
7127 ** any other process is running a checkpoint operation at the same time, the
7128 ** lock cannot be obtained and SQLITE_BUSY is returned. Even if there is a
7129 ** busy-handler configured, it will not be invoked in this case.
7130 **
7131 ** The SQLITE_CHECKPOINT_FULL and RESTART modes also obtain the exclusive
7132 ** "writer" lock on the database file. If the writer lock cannot be obtained
7133 ** immediately, and a busy-handler is configured, it is invoked and the writer
7134 ** lock retried until either the busy-handler returns 0 or the lock is
7135 ** successfully obtained. The busy-handler is also invoked while waiting for
7136 ** database readers as described above. If the busy-handler returns 0 before
7137 ** the writer lock is obtained or while waiting for database readers, the
7138 ** checkpoint operation proceeds from that point in the same way as
7139 ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible
7140 ** without blocking any further. SQLITE_BUSY is returned in this case.
7141 **
7142 ** If parameter zDb is NULL or points to a zero length string, then the
7143 ** specified operation is attempted on all WAL databases. In this case the
7144 ** values written to output parameters *pnLog and *pnCkpt are undefined. If
7145 ** an SQLITE_BUSY error is encountered when processing one or more of the
7146 ** attached WAL databases, the operation is still attempted on any remaining
7147 ** attached databases and SQLITE_BUSY is returned to the caller. If any other
7148 ** error occurs while processing an attached database, processing is abandoned
7149 ** and the error code returned to the caller immediately. If no error
7150 ** (SQLITE_BUSY or otherwise) is encountered while processing the attached
7151 ** databases, SQLITE_OK is returned.
7152 **
7153 ** If database zDb is the name of an attached database that is not in WAL
7154 ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. If
7155 ** zDb is not NULL (or a zero length string) and is not the name of any
7156 ** attached database, SQLITE_ERROR is returned to the caller.
7157 */
7159  sqlite3 *db, /* Database handle */
7160  const char *zDb, /* Name of attached database (or NULL) */
7161  int eMode, /* SQLITE_CHECKPOINT_* value */
7162  int *pnLog, /* OUT: Size of WAL log in frames */
7163  int *pnCkpt /* OUT: Total number of frames checkpointed */
7164 );
7165 
7166 /*
7167 ** CAPI3REF: Checkpoint operation parameters
7168 **
7169 ** These constants can be used as the 3rd parameter to
7170 ** [sqlite3_wal_checkpoint_v2()]. See the [sqlite3_wal_checkpoint_v2()]
7171 ** documentation for additional information about the meaning and use of
7172 ** each of these values.
7173 */
7174 #define SQLITE_CHECKPOINT_PASSIVE 0
7175 #define SQLITE_CHECKPOINT_FULL 1
7176 #define SQLITE_CHECKPOINT_RESTART 2
7177 
7178 /*
7179 ** CAPI3REF: Virtual Table Interface Configuration
7180 **
7181 ** This function may be called by either the [xConnect] or [xCreate] method
7182 ** of a [virtual table] implementation to configure
7183 ** various facets of the virtual table interface.
7184 **
7185 ** If this interface is invoked outside the context of an xConnect or
7186 ** xCreate virtual table method then the behavior is undefined.
7187 **
7188 ** At present, there is only one option that may be configured using
7189 ** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options
7190 ** may be added in the future.
7191 */
7192 SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...);
7193 
7194 /*
7195 ** CAPI3REF: Virtual Table Configuration Options
7196 **
7197 ** These macros define the various options to the
7198 ** [sqlite3_vtab_config()] interface that [virtual table] implementations
7199 ** can use to customize and optimize their behavior.
7200 **
7201 ** <dl>
7202 ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT
7203 ** <dd>Calls of the form
7204 ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported,
7205 ** where X is an integer. If X is zero, then the [virtual table] whose
7206 ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not
7207 ** support constraints. In this configuration (which is the default) if
7208 ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire
7209 ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been
7210 ** specified as part of the users SQL statement, regardless of the actual
7211 ** ON CONFLICT mode specified.
7212 **
7213 ** If X is non-zero, then the virtual table implementation guarantees
7214 ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before
7215 ** any modifications to internal or persistent data structures have been made.
7216 ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite
7217 ** is able to roll back a statement or database transaction, and abandon
7218 ** or continue processing the current SQL statement as appropriate.
7219 ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns
7220 ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode
7221 ** had been ABORT.
7222 **
7223 ** Virtual table implementations that are required to handle OR REPLACE
7224 ** must do so within the [xUpdate] method. If a call to the
7225 ** [sqlite3_vtab_on_conflict()] function indicates that the current ON
7226 ** CONFLICT policy is REPLACE, the virtual table implementation should
7227 ** silently replace the appropriate rows within the xUpdate callback and
7228 ** return SQLITE_OK. Or, if this is not possible, it may return
7229 ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT
7230 ** constraint handling.
7231 ** </dl>
7232 */
7233 #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1
7234 
7235 /*
7236 ** CAPI3REF: Determine The Virtual Table Conflict Policy
7237 **
7238 ** This function may only be called from within a call to the [xUpdate] method
7239 ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The
7240 ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL],
7241 ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode
7242 ** of the SQL statement that triggered the call to the [xUpdate] method of the
7243 ** [virtual table].
7244 */
7246 
7247 /*
7248 ** CAPI3REF: Conflict resolution modes
7249 **
7250 ** These constants are returned by [sqlite3_vtab_on_conflict()] to
7251 ** inform a [virtual table] implementation what the [ON CONFLICT] mode
7252 ** is for the SQL statement being evaluated.
7253 **
7254 ** Note that the [SQLITE_IGNORE] constant is also used as a potential
7255 ** return value from the [sqlite3_set_authorizer()] callback and that
7256 ** [SQLITE_ABORT] is also a [result code].
7257 */
7258 #define SQLITE_ROLLBACK 1
7259 /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */
7260 #define SQLITE_FAIL 3
7261 /* #define SQLITE_ABORT 4 // Also an error code */
7262 #define SQLITE_REPLACE 5
7263 
7264 
7265 
7266 /*
7267 ** Undo the hack that converts floating point types to integer for
7268 ** builds on processors without floating point support.
7269 */
7270 #ifdef SQLITE_OMIT_FLOATING_POINT
7271 # undef double
7272 #endif
7273 
7274 #ifdef __cplusplus
7275 } /* End of the 'extern "C"' block */
7276 #endif
7277 #endif /* _SQLITE3_H_ */
7278 
7279 /*
7280 ** 2010 August 30
7281 **
7282 ** The author disclaims copyright to this source code. In place of
7283 ** a legal notice, here is a blessing:
7284 **
7285 ** May you do good and not evil.
7286 ** May you find forgiveness for yourself and forgive others.
7287 ** May you share freely, never taking more than you give.
7288 **
7289 *************************************************************************
7290 */
7291 
7292 #ifndef _SQLITE3RTREE_H_
7293 #define _SQLITE3RTREE_H_
7294 
7295 
7296 #ifdef __cplusplus
7297 extern "C" {
7298 #endif
7299 
7301 
7302 /*
7303 ** Register a geometry callback named zGeom that can be used as part of an
7304 ** R-Tree geometry query as follows:
7305 **
7306 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...)
7307 */
7309  sqlite3 *db,
7310  const char *zGeom,
7311 #ifdef SQLITE_RTREE_INT_ONLY
7312  int (*xGeom)(sqlite3_rtree_geometry*, int n, sqlite3_int64 *a, int *pRes),
7313 #else
7314  int (*xGeom)(sqlite3_rtree_geometry*, int n, double *a, int *pRes),
7315 #endif
7316  void *pContext
7317 );
7318 
7319 
7320 /*
7321 ** A pointer to a structure of the following type is passed as the first
7322 ** argument to callbacks registered using rtree_geometry_callback().
7323 */
7324 struct sqlite3_rtree_geometry {
7325  void *pContext; /* Copy of pContext passed to s_r_g_c() */
7326  int nParam; /* Size of array aParam[] */
7327  double *aParam; /* Parameters passed to SQL geom function */
7328  void *pUser; /* Callback implementation user data */
7329  void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */
7330 };
7331 
7332 
7333 #ifdef __cplusplus
7334 } /* end of the 'extern "C"' block */
7335 #endif
7336 
7337 #endif /* ifndef _SQLITE3RTREE_H_ */
7338 
SQLITE_API int sqlite3_bind_value(sqlite3_stmt *, int, const sqlite3_value *)
Definition: sqlite3.c:65542
SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt)
Definition: sqlite3.c:64502
SQLITE_API int sqlite3_exec(sqlite3 *, const char *sql, int(*callback)(void *, int, char **, char **), void *, char **errmsg)
Definition: sqlite3.c:94915
SQLITE_API int sqlite3_bind_int(sqlite3_stmt *, int, int)
Definition: sqlite3.c:65500
SQLITE_API int sqlite3_value_type(sqlite3_value *)
Definition: sqlite3.c:64585
SQLITE_API int sqlite3_prepare16(sqlite3 *db, const void *zSql, int nByte, sqlite3_stmt **ppStmt, const void **pzTail)
Definition: sqlite3.c:99437
SQLITE_API sqlite3_stmt * sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt)
Definition: sqlite3.c:65709
SQLITE_API const void * sqlite3_errmsg16(sqlite3 *)
Definition: sqlite3.c:120887
SQLITE_API void * sqlite3_realloc(void *, int)
Definition: sqlite3.c:19516
SQLITE_API void * sqlite3_get_auxdata(sqlite3_context *, int N)
Definition: sqlite3.c:65016
SQLITE_API int sqlite3_column_int(sqlite3_stmt *, int iCol)
Definition: sqlite3.c:65213
SQLITE_API double sqlite3_column_double(sqlite3_stmt *, int iCol)
Definition: sqlite3.c:65208
SQLITE_API sqlite3_mutex * sqlite3_mutex_alloc(int)
Definition: sqlite3.c:17971
SQLITE_API int sqlite3_table_column_metadata(sqlite3 *db, const char *zDbName, const char *zTableName, const char *zColumnName, char const **pzDataType, char const **pzCollSeq, int *pNotNull, int *pPrimaryKey, int *pAutoinc)
SQLITE_API int sqlite3_bind_int64(sqlite3_stmt *, int, sqlite3_int64)
Definition: sqlite3.c:65503
SQLITE_API int sqlite3_column_type(sqlite3_stmt *, int iCol)
Definition: sqlite3.c:65244
SQLITE_API const void * sqlite3_value_text16le(sqlite3_value *)
Definition: sqlite3.c:64581
SQLITE_API int sqlite3_extended_errcode(sqlite3 *db)
Definition: sqlite3.c:120942
SQLITE_API const void * sqlite3_column_decltype16(sqlite3_stmt *, int)
Definition: sqlite3.c:65330
SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs *)
Definition: sqlite3.c:15648
unsigned long long int sqlite_uint64
Definition: sqlite3.h:254
SQLITE_API void sqlite3_free_table(char **result)
Definition: sqlite3.c:104566
SQLITE_API int sqlite3_release_memory(int)
Definition: sqlite3.c:18972
SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context *)
Definition: sqlite3.c:65082
SQLITE_API const void * sqlite3_column_name16(sqlite3_stmt *, int N)
Definition: sqlite3.c:65305
SQLITE_API void * sqlite3_commit_hook(sqlite3 *, int(*)(void *), void *)
Definition: sqlite3.c:120604
SQLITE_API void sqlite3_result_null(sqlite3_context *)
Definition: sqlite3.c:64644
SQLITE_API sqlite3 * sqlite3_context_db_handle(sqlite3_context *)
Definition: sqlite3.c:64944
SQLITE_API void sqlite3_result_zeroblob(sqlite3_context *, int n)
Definition: sqlite3.c:64690
SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N)
Definition: sqlite3.c:19098
SQLITE_API int sqlite3_create_module(sqlite3 *db, const char *zName, const sqlite3_module *p, void *pClientData)
Definition: sqlite3.c:106932
SQLITE_API const unsigned char * sqlite3_column_text(sqlite3_stmt *, int iCol)
Definition: sqlite3.c:65223
SQLITE_API int sqlite3_wal_checkpoint_v2(sqlite3 *db, const char *zDb, int eMode, int *pnLog, int *pnCkpt)
Definition: sqlite3.c:120726
SQLITE_API int sqlite3_set_authorizer(sqlite3 *, int(*xAuth)(void *, int, const char *, const char *, const char *, const char *), void *pUserData)
Definition: sqlite3.c:84062
SQLITE_API SQLITE_EXPERIMENTAL void * sqlite3_profile(sqlite3 *, void(*xProfile)(void *, const char *, sqlite3_uint64), void *)
Definition: sqlite3.c:120584
SQLITE_API int sqlite3_create_module_v2(sqlite3 *db, const char *zName, const sqlite3_module *p, void *pClientData, void(*xDestroy)(void *))
Definition: sqlite3.c:106944
SQLITE_API sqlite3_backup * sqlite3_backup_init(sqlite3 *pDest, const char *zDestName, sqlite3 *pSource, const char *zSourceName)
Definition: sqlite3.c:59018
SQLITE_API int sqlite3_mutex_try(sqlite3_mutex *)
Definition: sqlite3.c:18009
#define SQLITE_EXPERIMENTAL
Definition: sqlite3.h:71
SQLITE_API int sqlite3_value_numeric_type(sqlite3_value *)
Definition: sqlite3.c:66334
SQLITE_API int sqlite3_libversion_number(void)
Definition: sqlite3.c:119050
Btree * pDest
Definition: sqlite3.c:58908
SQLITE_API int sqlite3_close(sqlite3 *)
Definition: sqlite3.c:119887
void(* sqlite3_destructor_type)(void *)
Definition: sqlite3.h:4272
SQLITE_API void * sqlite3_trace(sqlite3 *, void(*xTrace)(void *, const char *), void *)
Definition: sqlite3.c:120567
SQLITE_API sqlite3_value * sqlite3_column_value(sqlite3_stmt *, int iCol)
Definition: sqlite3.c:65228
SQLITE_API void sqlite3_reset_auto_extension(void)
Definition: sqlite3.c:96221
#define SQLITE_DEPRECATED
Definition: sqlite3.h:70
SQLITE_API int sqlite3_os_init(void)
Definition: sqlite3.c:30653
SQLITE_API void * sqlite3_update_hook(sqlite3 *, void(*)(void *, int, char const *, char const *, sqlite3_int64), void *)
Definition: sqlite3.c:120622
SQLITE_API int sqlite3_overload_function(sqlite3 *, const char *zFuncName, int nArg)
Definition: sqlite3.c:120541
SQLITE_API void sqlite3_result_blob(sqlite3_context *, const void *, int, void(*)(void *))
Definition: sqlite3.c:64608
SQLITE_API int sqlite3_open16(const void *filename, sqlite3 **ppDb)
Definition: sqlite3.c:121694
struct sqlite3_stmt sqlite3_stmt
SQLITE_API int sqlite3_blob_close(sqlite3_blob *)
Definition: sqlite3.c:73317
SQLITE_API SQLITE_EXTERN const char sqlite3_version[]
Definition: sqlite3.h:144
SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt)
Definition: sqlite3.c:65691
SQLITE_API int sqlite3_bind_text16(sqlite3_stmt *, int, const void *, int, void(*)(void *))
Definition: sqlite3.c:65532
SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value *)
Definition: sqlite3.c:64568
SQLITE_API const char * sqlite3_column_origin_name(sqlite3_stmt *, int)
SQLITE_API int sqlite3_get_autocommit(sqlite3 *)
Definition: sqlite3.c:121845
SQLITE_API int sqlite3_db_config(sqlite3 *, int op,...)
Definition: sqlite3.c:119628
SQLITE_API int sqlite3_prepare(sqlite3 *db, const char *zSql, int nByte, sqlite3_stmt **ppStmt, const char **pzTail)
Definition: sqlite3.c:99351
SQLITE_API void sqlite3_randomness(int N, void *P)
Definition: sqlite3.c:20734
SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat,...)
Definition: sqlite3.c:20659
SQLITE_API int sqlite3_open(const char *filename, sqlite3 **ppDb)
Definition: sqlite3.c:121674
SQLITE_API void sqlite3_result_error16(sqlite3_context *, const void *, int)
Definition: sqlite3.c:64629
SQLITE_API int sqlite3_value_bytes(sqlite3_value *)
Definition: sqlite3.c:64556
SQLITE_API const char * sqlite3_db_filename(sqlite3 *db, const char *zDbName)
Definition: sqlite3.c:122385
SQLITE_API int sqlite3_prepare16_v2(sqlite3 *db, const void *zSql, int nByte, sqlite3_stmt **ppStmt, const void **pzTail)
Definition: sqlite3.c:99449
#define SQLITE_API
Definition: sqlite3.h:53
SQLITE_API int sqlite3_config(int,...)
Definition: sqlite3.c:119327
SQLITE_API void sqlite3_result_text16le(sqlite3_context *, const void *, int, void(*)(void *))
Definition: sqlite3.c:64676
SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64)
Definition: sqlite3.c:73419
SQLITE_API int sqlite3_busy_timeout(sqlite3 *, int ms)
Definition: sqlite3.c:120336
SQLITE_API int sqlite3_create_collation16(sqlite3 *, const void *zName, int eTextRep, void *pArg, int(*xCompare)(void *, int, const void *, int, const void *))
Definition: sqlite3.c:121771
SQLITE_API int sqlite3_prepare_v2(sqlite3 *db, const char *zSql, int nByte, sqlite3_stmt **ppStmt, const char **pzTail)
Definition: sqlite3.c:99363
SQLITE_API const char * sqlite3_column_database_name(sqlite3_stmt *, int)
SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb)
Definition: sqlite3.c:120773
SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void))
Definition: sqlite3.c:96153
SQLITE_API int sqlite3_threadsafe(void)
Definition: sqlite3.c:119056
SQLITE_API int sqlite3_declare_vtab(sqlite3 *, const char *zSQL)
Definition: sqlite3.c:107548
SQLITE_API int sqlite3_vtab_config(sqlite3 *, int op,...)
Definition: sqlite3.c:107922
SQLITE_API sqlite3_vfs * sqlite3_vfs_find(const char *zVfsName)
Definition: sqlite3.c:15578
SQLITE_API const char * sqlite3_column_decltype(sqlite3_stmt *, int)
Definition: sqlite3.c:65325
SQLITE_API int sqlite3_create_function(sqlite3 *db, const char *zFunctionName, int nArg, int eTextRep, void *pApp, void(*xFunc)(sqlite3_context *, int, sqlite3_value **), void(*xStep)(sqlite3_context *, int, sqlite3_value **), void(*xFinal)(sqlite3_context *))
Definition: sqlite3.c:120454
SQLITE_API const void * sqlite3_value_text16(sqlite3_value *)
Definition: sqlite3.c:64575
SQLITE_API const char * sqlite3_compileoption_get(int N)
Definition: sqlite3.c:13381
SQLITE_API const char * sqlite3_errstr(int)
Definition: sqlite3.c:120957
SQLITE_API int sqlite3_unlock_notify(sqlite3 *pBlocked, void(*xNotify)(void **apArg, int nArg), void *pNotifyArg)
SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt)
Definition: sqlite3.c:65091
SQLITE_API void sqlite3_result_text(sqlite3_context *, const char *, int, void(*)(void *))
Definition: sqlite3.c:64648
sqlite_uint64 sqlite3_uint64
Definition: sqlite3.h:257
SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff)
Definition: sqlite3.c:96096
SQLITE_API const char * sqlite3_column_name(sqlite3_stmt *, int N)
Definition: sqlite3.c:65300
SQLITE_API char * sqlite3_mprintf(const char *,...)
Definition: sqlite3.c:20594
SQLITE_API int sqlite3_step(sqlite3_stmt *)
Definition: sqlite3.c:64880
SQLITE_API const char * sqlite3_errmsg(sqlite3 *)
Definition: sqlite3.c:120860
SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt *)
Definition: sqlite3.c:64521
SQLITE_API int sqlite3_bind_text(sqlite3_stmt *, int, const char *, int n, void(*)(void *))
Definition: sqlite3.c:65522
SQLITE_API const char * sqlite3_sourceid(void)
Definition: sqlite3.c:119045
SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex *)
Definition: sqlite3.c:17999
SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr)
Definition: sqlite3.c:90433
SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt *, const char *zName)
Definition: sqlite3.c:65627
SQLITE_API char * sqlite3_snprintf(int, char *, const char *,...)
Definition: sqlite3.c:20627
SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N)
Definition: sqlite3.c:19078
SQLITE_API double sqlite3_value_double(sqlite3_value *)
Definition: sqlite3.c:64562
SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex *)
Definition: sqlite3.c:18023
SQLITE_API int sqlite3_load_extension(sqlite3 *db, const char *zFile, const char *zProc, char **pzErrMsg)
Definition: sqlite3.c:96065
SQLITE_API const void * sqlite3_value_text16be(sqlite3_value *)
Definition: sqlite3.c:64578
SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p)
Definition: sqlite3.c:59518
SQLITE_API sqlite3_mutex * sqlite3_db_mutex(sqlite3 *)
Definition: sqlite3.c:119601
SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt *)
Definition: sqlite3.c:65698
SQLITE_API int sqlite3_vfs_register(sqlite3_vfs *, int makeDflt)
Definition: sqlite3.c:15624
SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt)
Definition: sqlite3.c:64476
SQLITE_API int sqlite3_file_control(sqlite3 *, const char *zDbName, int op, void *)
Definition: sqlite3.c:122037
SQLITE_API int sqlite3_stmt_status(sqlite3_stmt *, int op, int resetFlg)
Definition: sqlite3.c:65724
SQLITE_API int sqlite3_changes(sqlite3 *)
Definition: sqlite3.c:119747
SQLITE_API SQLITE_EXTERN char * sqlite3_temp_directory
Definition: sqlite3.h:4660
SQLITE_API char * sqlite3_vsnprintf(int, char *, const char *, va_list)
Definition: sqlite3.c:20619
SQLITE_API const void * sqlite3_column_table_name16(sqlite3_stmt *, int)
SQLITE_API int sqlite3_create_collation(sqlite3 *, const char *zName, int eTextRep, void *pArg, int(*xCompare)(void *, int, const void *, int, const void *))
Definition: sqlite3.c:121731
SQLITE_API int sqlite3_close_v2(sqlite3 *)
Definition: sqlite3.c:119888
SQLITE_API int sqlite3_create_collation_v2(sqlite3 *, const char *zName, int eTextRep, void *pArg, int(*xCompare)(void *, int, const void *, int, const void *), void(*xDestroy)(void *))
Definition: sqlite3.c:121750
SQLITE_API void sqlite3_result_text16be(sqlite3_context *, const void *, int, void(*)(void *))
Definition: sqlite3.c:64667
SQLITE_API char * sqlite3_vmprintf(const char *, va_list)
Definition: sqlite3.c:20576
SQLITE_API void * sqlite3_wal_hook(sqlite3 *, int(*)(void *, sqlite3 *, const char *, int), void *)
Definition: sqlite3.c:120705
#define SQLITE_EXTERN
Definition: sqlite3.h:49
SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *)
Definition: sqlite3.c:73404
Definition: sqlite3.c:13567
SQLITE_API int sqlite3_column_bytes(sqlite3_stmt *, int iCol)
Definition: sqlite3.c:65198
SQLITE_API const void * sqlite3_value_blob(sqlite3_value *)
Definition: sqlite3.c:64545
SQLITE_API int sqlite3_create_function_v2(sqlite3 *db, const char *zFunctionName, int nArg, int eTextRep, void *pApp, void(*xFunc)(sqlite3_context *, int, sqlite3_value **), void(*xStep)(sqlite3_context *, int, sqlite3_value **), void(*xFinal)(sqlite3_context *), void(*xDestroy)(void *))
Definition: sqlite3.c:120468
SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault)
Definition: sqlite3.c:122344
SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt)
Definition: sqlite3.c:65100
SQLITE_API void * sqlite3_aggregate_context(sqlite3_context *, int nBytes)
Definition: sqlite3.c:64989
SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset)
Definition: sqlite3.c:73387
SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset)
Definition: sqlite3.c:73394
void(* sqlite3_syscall_ptr)(void)
Definition: sqlite3.h:1115
SQLITE_API void * sqlite3_user_data(sqlite3_context *)
Definition: sqlite3.c:64929
SQLITE_API int sqlite3_collation_needed16(sqlite3 *, void *, void(*)(void *, sqlite3 *, int eTextRep, const void *))
Definition: sqlite3.c:121815
SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt *)
Definition: sqlite3.c:64439
SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void)
Definition: sqlite3.c:121891
SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char *, const char *, sqlite3_int64)
Definition: sqlite3.c:122353
SQLITE_API void sqlite3_result_text16(sqlite3_context *, const void *, int, void(*)(void *))
Definition: sqlite3.c:64658
SQLITE_API int sqlite3_blob_open(sqlite3 *, const char *zDb, const char *zTable, const char *zColumn, sqlite3_int64 iRow, int flags, sqlite3_blob **ppBlob)
Definition: sqlite3.c:73083
SQLITE_API void sqlite3_progress_handler(sqlite3 *, int, int(*)(void *), void *)
Definition: sqlite3.c:120311
const struct sqlite3_io_methods * pMethods
Definition: sqlite3.c:661
SQLITE_API const void * sqlite3_column_origin_name16(sqlite3_stmt *, int)
SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt *, int, int n)
Definition: sqlite3.c:65573
SQLITE_API int sqlite3_open_v2(const char *filename, sqlite3 **ppDb, int flags, const char *zVfs)
Definition: sqlite3.c:121681
SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3 *)
Definition: sqlite3.c:119740
SQLITE_API int sqlite3_initialize(void)
Definition: sqlite3.c:119117
SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void *, sqlite3_int64, int), void *, sqlite3_int64)
SQLITE_API int sqlite3_test_control(int op,...)
Definition: sqlite3.c:122068
SQLITE_API int sqlite3_bind_blob(sqlite3_stmt *, int, const void *, int n, void(*)(void *))
Definition: sqlite3.c:65481
SQLITE_API const unsigned char * sqlite3_value_text(sqlite3_value *)
Definition: sqlite3.c:64571
SQLITE_API void sqlite3_interrupt(sqlite3 *)
Definition: sqlite3.c:120349
SQLITE_API int sqlite3_shutdown(void)
Definition: sqlite3.c:119280
SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt *, sqlite3_stmt *)
Definition: sqlite3.c:65661
SQLITE_API void sqlite3_set_auxdata(sqlite3_context *, int N, void *, void(*)(void *))
Definition: sqlite3.c:65032
SQLITE_API int sqlite3_value_bytes16(sqlite3_value *)
Definition: sqlite3.c:64559
SQLITE_API int sqlite3_create_function16(sqlite3 *db, const void *zFunctionName, int nArg, int eTextRep, void *pApp, void(*xFunc)(sqlite3_context *, int, sqlite3_value **), void(*xStep)(sqlite3_context *, int, sqlite3_value **), void(*xFinal)(sqlite3_context *))
Definition: sqlite3.c:120505
SQLITE_API int sqlite3_errcode(sqlite3 *db)
Definition: sqlite3.c:120933
SQLITE_API void sqlite3_result_double(sqlite3_context *, double)
Definition: sqlite3.c:64618
SQLITE_API sqlite3_int64 sqlite3_memory_used(void)
Definition: sqlite3.c:19167
SQLITE_API int sqlite3_os_end(void)
Definition: sqlite3.c:30750
SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex *)
SQLITE_API int sqlite3_sleep(int)
Definition: sqlite3.c:122011
SQLITE_API int sqlite3_rtree_geometry_callback(sqlite3 *db, const char *zGeom, int(*xGeom)(sqlite3_rtree_geometry *, int n, double *a, int *pRes), void *pContext)
SQLITE_API void sqlite3_result_value(sqlite3_context *, sqlite3_value *)
Definition: sqlite3.c:64686
SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt *, int iCol)
Definition: sqlite3.c:65203
SQLITE_API void sqlite3_result_error_code(sqlite3_context *, int)
Definition: sqlite3.c:64694
SQLITE_API int sqlite3_db_release_memory(sqlite3 *)
Definition: sqlite3.c:119609
SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void)
Definition: sqlite3.c:121834
SQLITE_API void * sqlite3_malloc(int)
Definition: sqlite3.c:19273
SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *)
Definition: sqlite3.c:107907
SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt *)
Definition: sqlite3.c:65588
SQLITE_API SQLITE_EXTERN char * sqlite3_data_directory
Definition: sqlite3.h:4697
SQLITE_API int sqlite3_collation_needed(sqlite3 *, void *, void(*)(void *, sqlite3 *, int eTextRep, const char *))
Definition: sqlite3.c:121797
SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p)
Definition: sqlite3.c:59458
SQLITE_API int sqlite3_complete16(const void *sql)
Definition: sqlite3.c:118889
SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName)
Definition: sqlite3.c:122394
SQLITE_API void sqlite3_mutex_free(sqlite3_mutex *)
Definition: sqlite3.c:17989
SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p)
Definition: sqlite3.c:59510
SQLITE_API void sqlite3_result_error_nomem(sqlite3_context *)
Definition: sqlite3.c:64713
SQLITE_API const char * sqlite3_uri_parameter(const char *zFilename, const char *zParam)
Definition: sqlite3.c:122329
SQLITE_API int sqlite3_mutex_held(sqlite3_mutex *)
SQLITE_API void * sqlite3_rollback_hook(sqlite3 *, void(*)(void *), void *)
Definition: sqlite3.c:120640
SQLITE_API int sqlite3_total_changes(sqlite3 *)
Definition: sqlite3.c:119754
SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N)
Definition: sqlite3.c:120687
SQLITE_API int sqlite3_bind_double(sqlite3_stmt *, int, double)
Definition: sqlite3.c:65490
SQLITE_API const char * sqlite3_sql(sqlite3_stmt *pStmt)
Definition: sqlite3.c:61073
SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt *, int iCol)
Definition: sqlite3.c:65218
SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage)
Definition: sqlite3.c:59216
SQLITE_API int sqlite3_bind_null(sqlite3_stmt *, int)
Definition: sqlite3.c:65513
int(* sqlite3_callback)(void *, int, char **, char **)
Definition: sqlite3.h:316
struct sqlite3_blob sqlite3_blob
Definition: sqlite3.c:5529
SQLITE_API void sqlite3_result_int(sqlite3_context *, int)
Definition: sqlite3.c:64636
SQLITE_API int sqlite3_complete(const char *sql)
Definition: sqlite3.c:118731
SQLITE_API int sqlite3_enable_shared_cache(int)
Definition: sqlite3.c:50438
SQLITE_API const void * sqlite3_column_database_name16(sqlite3_stmt *, int)
struct sqlite3_pcache sqlite3_pcache
Definition: sqlite3.c:6439
SQLITE_API int sqlite3_compileoption_used(const char *zOptName)
Definition: sqlite3.c:13360
SQLITE_API int sqlite3_limit(sqlite3 *, int id, int newVal)
Definition: sqlite3.c:121129
SQLITE_API const char * sqlite3_libversion(void)
Definition: sqlite3.c:119039
SQLITE_API int sqlite3_busy_handler(sqlite3 *, int(*)(void *, int), void *)
Definition: sqlite3.c:120291
SQLITE_API const char * sqlite3_column_table_name(sqlite3_stmt *, int)
sqlite_int64 sqlite3_int64
Definition: sqlite3.h:256
SQLITE_API int sqlite3_get_table(sqlite3 *db, const char *zSql, char ***pazResult, int *pnRow, int *pnColumn, char **pzErrmsg)
Definition: sqlite3.c:104500
SQLITE_API void sqlite3_result_error_toobig(sqlite3_context *)
Definition: sqlite3.c:64704
SQLITE_API int sqlite3_db_status(sqlite3 *, int op, int *pCur, int *pHiwtr, int resetFlg)
Definition: sqlite3.c:13977
long long int sqlite_int64
Definition: sqlite3.h:253
SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag)
Definition: sqlite3.c:19180
SQLITE_API int sqlite3_extended_result_codes(sqlite3 *, int onoff)
Definition: sqlite3.c:122027
SQLITE_API void sqlite3_result_int64(sqlite3_context *, sqlite3_int64)
Definition: sqlite3.c:64640
SQLITE_API sqlite3 * sqlite3_db_handle(sqlite3_stmt *)
Definition: sqlite3.c:65683
SQLITE_API void sqlite3_free(void *)
Definition: sqlite3.c:19415
SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag)
Definition: sqlite3.c:13961
SQLITE_API int sqlite3_stricmp(const char *, const char *)
Definition: sqlite3.c:21582
SQLITE_API void sqlite3_result_error(sqlite3_context *, const char *, int)
Definition: sqlite3.c:64622
SQLITE_API const void * sqlite3_column_blob(sqlite3_stmt *, int iCol)
Definition: sqlite3.c:65188
SQLITE_API const char * sqlite3_bind_parameter_name(sqlite3_stmt *, int)
Definition: sqlite3.c:65599
SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void))
Definition: sqlite3.c:96198
SQLITE_API const void * sqlite3_column_text16(sqlite3_stmt *, int iCol)
Definition: sqlite3.c:65238
SQLITE_API int sqlite3_strnicmp(const char *, const char *, int)
Definition: sqlite3.c:21589
SQLITE_API int sqlite3_value_int(sqlite3_value *)
Definition: sqlite3.c:64565


rtabmap
Author(s): Mathieu Labbe
autogenerated on Mon Jan 23 2023 03:38:57