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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 "3.8.5" |
111 | #define SQLITE_VERSION_NUMBER 3008005 |
112 | #define SQLITE_SOURCE_ID "2014-06-04 14:06:34 b1ed4f2a34ba66c29b130f8d13e9092758019212" |
113 | |
114 | /* |
115 | ** CAPI3REF: Run-Time Library Version Numbers |
116 | ** KEYWORDS: sqlite3_version, sqlite3_sourceid |
117 | ** |
118 | ** These interfaces provide the same information as the [SQLITE_VERSION], |
119 | ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros |
120 | ** but are associated with the library instead of the header file. ^(Cautious |
121 | ** programmers might include assert() statements in their application to |
122 | ** verify that values returned by these interfaces match the macros in |
123 | ** the header, and thus insure that the application is |
124 | ** compiled with matching library and header files. |
125 | ** |
126 | ** <blockquote><pre> |
127 | ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); |
128 | ** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 ); |
129 | ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); |
130 | ** </pre></blockquote>)^ |
131 | ** |
132 | ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] |
133 | ** macro. ^The sqlite3_libversion() function returns a pointer to the |
134 | ** to the sqlite3_version[] string constant. The sqlite3_libversion() |
135 | ** function is provided for use in DLLs since DLL users usually do not have |
136 | ** direct access to string constants within the DLL. ^The |
137 | ** sqlite3_libversion_number() function returns an integer equal to |
138 | ** [SQLITE_VERSION_NUMBER]. ^The sqlite3_sourceid() function returns |
139 | ** a pointer to a string constant whose value is the same as the |
140 | ** [SQLITE_SOURCE_ID] C preprocessor macro. |
141 | ** |
142 | ** See also: [sqlite_version()] and [sqlite_source_id()]. |
143 | */ |
144 | SQLITE_API SQLITE_EXTERN const char sqlite3_version[]; |
145 | SQLITE_API const char *sqlite3_libversion(void); |
146 | SQLITE_API const char *sqlite3_sourceid(void); |
147 | SQLITE_API int sqlite3_libversion_number(void); |
148 | |
149 | /* |
150 | ** CAPI3REF: Run-Time Library Compilation Options Diagnostics |
151 | ** |
152 | ** ^The sqlite3_compileoption_used() function returns 0 or 1 |
153 | ** indicating whether the specified option was defined at |
154 | ** compile time. ^The SQLITE_ prefix may be omitted from the |
155 | ** option name passed to sqlite3_compileoption_used(). |
156 | ** |
157 | ** ^The sqlite3_compileoption_get() function allows iterating |
158 | ** over the list of options that were defined at compile time by |
159 | ** returning the N-th compile time option string. ^If N is out of range, |
160 | ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ |
161 | ** prefix is omitted from any strings returned by |
162 | ** sqlite3_compileoption_get(). |
163 | ** |
164 | ** ^Support for the diagnostic functions sqlite3_compileoption_used() |
165 | ** and sqlite3_compileoption_get() may be omitted by specifying the |
166 | ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. |
167 | ** |
168 | ** See also: SQL functions [sqlite_compileoption_used()] and |
169 | ** [sqlite_compileoption_get()] and the [compile_options pragma]. |
170 | */ |
171 | #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS |
172 | SQLITE_API int sqlite3_compileoption_used(const char *zOptName); |
173 | SQLITE_API const char *sqlite3_compileoption_get(int N); |
174 | #endif |
175 | |
176 | /* |
177 | ** CAPI3REF: Test To See If The Library Is Threadsafe |
178 | ** |
179 | ** ^The sqlite3_threadsafe() function returns zero if and only if |
180 | ** SQLite was compiled 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 | */ |
212 | SQLITE_API int sqlite3_threadsafe(void); |
213 | |
214 | /* |
215 | ** CAPI3REF: Database Connection Handle |
216 | ** KEYWORDS: {database connection} {database connections} |
217 | ** |
218 | ** Each open SQLite database is represented by a pointer to an instance of |
219 | ** the opaque structure named "sqlite3". It is useful to think of an sqlite3 |
220 | ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and |
221 | ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] |
222 | ** 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 | */ |
308 | SQLITE_API int sqlite3_close(sqlite3*); |
309 | SQLITE_API int sqlite3_close_v2(sqlite3*); |
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 | */ |
379 | SQLITE_API int sqlite3_exec( |
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_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) |
495 | #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) |
496 | #define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) |
497 | #define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) |
498 | #define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) |
499 | #define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) |
500 | #define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) |
501 | #define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) |
502 | #define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) |
503 | #define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) |
504 | #define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) |
505 | #define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) |
506 | #define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) |
507 | #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) |
508 | #define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) |
509 | |
510 | /* |
511 | ** CAPI3REF: Flags For File Open Operations |
512 | ** |
513 | ** These bit values are intended for use in the |
514 | ** 3rd parameter to the [sqlite3_open_v2()] interface and |
515 | ** in the 4th parameter to the [sqlite3_vfs.xOpen] method. |
516 | */ |
517 | #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ |
518 | #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ |
519 | #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ |
520 | #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ |
521 | #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ |
522 | #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ |
523 | #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ |
524 | #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ |
525 | #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ |
526 | #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ |
527 | #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ |
528 | #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ |
529 | #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ |
530 | #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ |
531 | #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ |
532 | #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ |
533 | #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ |
534 | #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ |
535 | #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ |
536 | #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ |
537 | |
538 | /* Reserved: 0x00F00000 */ |
539 | |
540 | /* |
541 | ** CAPI3REF: Device Characteristics |
542 | ** |
543 | ** The xDeviceCharacteristics method of the [sqlite3_io_methods] |
544 | ** object returns an integer which is a vector of these |
545 | ** bit values expressing I/O characteristics of the mass storage |
546 | ** device that holds the file that the [sqlite3_io_methods] |
547 | ** refers to. |
548 | ** |
549 | ** The SQLITE_IOCAP_ATOMIC property means that all writes of |
550 | ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values |
551 | ** mean that writes of blocks that are nnn bytes in size and |
552 | ** are aligned to an address which is an integer multiple of |
553 | ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means |
554 | ** that when data is appended to a file, the data is appended |
555 | ** first then the size of the file is extended, never the other |
556 | ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that |
557 | ** information is written to disk in the same order as calls |
558 | ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that |
559 | ** after reboot following a crash or power loss, the only bytes in a |
560 | ** file that were written at the application level might have changed |
561 | ** and that adjacent bytes, even bytes within the same sector are |
562 | ** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN |
563 | ** flag indicate that a file cannot be deleted when open. The |
564 | ** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on |
565 | ** read-only media and cannot be changed even by processes with |
566 | ** elevated privileges. |
567 | */ |
568 | #define SQLITE_IOCAP_ATOMIC 0x00000001 |
569 | #define SQLITE_IOCAP_ATOMIC512 0x00000002 |
570 | #define SQLITE_IOCAP_ATOMIC1K 0x00000004 |
571 | #define SQLITE_IOCAP_ATOMIC2K 0x00000008 |
572 | #define SQLITE_IOCAP_ATOMIC4K 0x00000010 |
573 | #define SQLITE_IOCAP_ATOMIC8K 0x00000020 |
574 | #define SQLITE_IOCAP_ATOMIC16K 0x00000040 |
575 | #define SQLITE_IOCAP_ATOMIC32K 0x00000080 |
576 | #define SQLITE_IOCAP_ATOMIC64K 0x00000100 |
577 | #define SQLITE_IOCAP_SAFE_APPEND 0x00000200 |
578 | #define SQLITE_IOCAP_SEQUENTIAL 0x00000400 |
579 | #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 |
580 | #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 |
581 | #define SQLITE_IOCAP_IMMUTABLE 0x00002000 |
582 | |
583 | /* |
584 | ** CAPI3REF: File Locking Levels |
585 | ** |
586 | ** SQLite uses one of these integer values as the second |
587 | ** argument to calls it makes to the xLock() and xUnlock() methods |
588 | ** of an [sqlite3_io_methods] object. |
589 | */ |
590 | #define SQLITE_LOCK_NONE 0 |
591 | #define SQLITE_LOCK_SHARED 1 |
592 | #define SQLITE_LOCK_RESERVED 2 |
593 | #define SQLITE_LOCK_PENDING 3 |
594 | #define SQLITE_LOCK_EXCLUSIVE 4 |
595 | |
596 | /* |
597 | ** CAPI3REF: Synchronization Type Flags |
598 | ** |
599 | ** When SQLite invokes the xSync() method of an |
600 | ** [sqlite3_io_methods] object it uses a combination of |
601 | ** these integer values as the second argument. |
602 | ** |
603 | ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the |
604 | ** sync operation only needs to flush data to mass storage. Inode |
605 | ** information need not be flushed. If the lower four bits of the flag |
606 | ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. |
607 | ** If the lower four bits equal SQLITE_SYNC_FULL, that means |
608 | ** to use Mac OS X style fullsync instead of fsync(). |
609 | ** |
610 | ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags |
611 | ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL |
612 | ** settings. The [synchronous pragma] determines when calls to the |
613 | ** xSync VFS method occur and applies uniformly across all platforms. |
614 | ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how |
615 | ** energetic or rigorous or forceful the sync operations are and |
616 | ** only make a difference on Mac OSX for the default SQLite code. |
617 | ** (Third-party VFS implementations might also make the distinction |
618 | ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the |
619 | ** operating systems natively supported by SQLite, only Mac OSX |
620 | ** cares about the difference.) |
621 | */ |
622 | #define SQLITE_SYNC_NORMAL 0x00002 |
623 | #define SQLITE_SYNC_FULL 0x00003 |
624 | #define SQLITE_SYNC_DATAONLY 0x00010 |
625 | |
626 | /* |
627 | ** CAPI3REF: OS Interface Open File Handle |
628 | ** |
629 | ** An [sqlite3_file] object represents an open file in the |
630 | ** [sqlite3_vfs | OS interface layer]. Individual OS interface |
631 | ** implementations will |
632 | ** want to subclass this object by appending additional fields |
633 | ** for their own use. The pMethods entry is a pointer to an |
634 | ** [sqlite3_io_methods] object that defines methods for performing |
635 | ** I/O operations on the open file. |
636 | */ |
637 | typedef struct sqlite3_file sqlite3_file; |
638 | struct sqlite3_file { |
639 | const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ |
640 | }; |
641 | |
642 | /* |
643 | ** CAPI3REF: OS Interface File Virtual Methods Object |
644 | ** |
645 | ** Every file opened by the [sqlite3_vfs.xOpen] method populates an |
646 | ** [sqlite3_file] object (or, more commonly, a subclass of the |
647 | ** [sqlite3_file] object) with a pointer to an instance of this object. |
648 | ** This object defines the methods used to perform various operations |
649 | ** against the open file represented by the [sqlite3_file] object. |
650 | ** |
651 | ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element |
652 | ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method |
653 | ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The |
654 | ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] |
655 | ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element |
656 | ** to NULL. |
657 | ** |
658 | ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or |
659 | ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). |
660 | ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] |
661 | ** flag may be ORed in to indicate that only the data of the file |
662 | ** and not its inode needs to be synced. |
663 | ** |
664 | ** The integer values to xLock() and xUnlock() are one of |
665 | ** <ul> |
666 | ** <li> [SQLITE_LOCK_NONE], |
667 | ** <li> [SQLITE_LOCK_SHARED], |
668 | ** <li> [SQLITE_LOCK_RESERVED], |
669 | ** <li> [SQLITE_LOCK_PENDING], or |
670 | ** <li> [SQLITE_LOCK_EXCLUSIVE]. |
671 | ** </ul> |
672 | ** xLock() increases the lock. xUnlock() decreases the lock. |
673 | ** The xCheckReservedLock() method checks whether any database connection, |
674 | ** either in this process or in some other process, is holding a RESERVED, |
675 | ** PENDING, or EXCLUSIVE lock on the file. It returns true |
676 | ** if such a lock exists and false otherwise. |
677 | ** |
678 | ** The xFileControl() method is a generic interface that allows custom |
679 | ** VFS implementations to directly control an open file using the |
680 | ** [sqlite3_file_control()] interface. The second "op" argument is an |
681 | ** integer opcode. The third argument is a generic pointer intended to |
682 | ** point to a structure that may contain arguments or space in which to |
683 | ** write return values. Potential uses for xFileControl() might be |
684 | ** functions to enable blocking locks with timeouts, to change the |
685 | ** locking strategy (for example to use dot-file locks), to inquire |
686 | ** about the status of a lock, or to break stale locks. The SQLite |
687 | ** core reserves all opcodes less than 100 for its own use. |
688 | ** A [SQLITE_FCNTL_LOCKSTATE | list of opcodes] less than 100 is available. |
689 | ** Applications that define a custom xFileControl method should use opcodes |
690 | ** greater than 100 to avoid conflicts. VFS implementations should |
691 | ** return [SQLITE_NOTFOUND] for file control opcodes that they do not |
692 | ** recognize. |
693 | ** |
694 | ** The xSectorSize() method returns the sector size of the |
695 | ** device that underlies the file. The sector size is the |
696 | ** minimum write that can be performed without disturbing |
697 | ** other bytes in the file. The xDeviceCharacteristics() |
698 | ** method returns a bit vector describing behaviors of the |
699 | ** underlying device: |
700 | ** |
701 | ** <ul> |
702 | ** <li> [SQLITE_IOCAP_ATOMIC] |
703 | ** <li> [SQLITE_IOCAP_ATOMIC512] |
704 | ** <li> [SQLITE_IOCAP_ATOMIC1K] |
705 | ** <li> [SQLITE_IOCAP_ATOMIC2K] |
706 | ** <li> [SQLITE_IOCAP_ATOMIC4K] |
707 | ** <li> [SQLITE_IOCAP_ATOMIC8K] |
708 | ** <li> [SQLITE_IOCAP_ATOMIC16K] |
709 | ** <li> [SQLITE_IOCAP_ATOMIC32K] |
710 | ** <li> [SQLITE_IOCAP_ATOMIC64K] |
711 | ** <li> [SQLITE_IOCAP_SAFE_APPEND] |
712 | ** <li> [SQLITE_IOCAP_SEQUENTIAL] |
713 | ** </ul> |
714 | ** |
715 | ** The SQLITE_IOCAP_ATOMIC property means that all writes of |
716 | ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values |
717 | ** mean that writes of blocks that are nnn bytes in size and |
718 | ** are aligned to an address which is an integer multiple of |
719 | ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means |
720 | ** that when data is appended to a file, the data is appended |
721 | ** first then the size of the file is extended, never the other |
722 | ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that |
723 | ** information is written to disk in the same order as calls |
724 | ** to xWrite(). |
725 | ** |
726 | ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill |
727 | ** in the unread portions of the buffer with zeros. A VFS that |
728 | ** fails to zero-fill short reads might seem to work. However, |
729 | ** failure to zero-fill short reads will eventually lead to |
730 | ** database corruption. |
731 | */ |
732 | typedef struct sqlite3_io_methods sqlite3_io_methods; |
733 | struct sqlite3_io_methods { |
734 | int iVersion; |
735 | int (*xClose)(sqlite3_file*); |
736 | int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); |
737 | int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); |
738 | int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); |
739 | int (*xSync)(sqlite3_file*, int flags); |
740 | int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); |
741 | int (*xLock)(sqlite3_file*, int); |
742 | int (*xUnlock)(sqlite3_file*, int); |
743 | int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); |
744 | int (*xFileControl)(sqlite3_file*, int op, void *pArg); |
745 | int (*xSectorSize)(sqlite3_file*); |
746 | int (*xDeviceCharacteristics)(sqlite3_file*); |
747 | /* Methods above are valid for version 1 */ |
748 | int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); |
749 | int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); |
750 | void (*xShmBarrier)(sqlite3_file*); |
751 | int (*xShmUnmap)(sqlite3_file*, int deleteFlag); |
752 | /* Methods above are valid for version 2 */ |
753 | int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); |
754 | int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); |
755 | /* Methods above are valid for version 3 */ |
756 | /* Additional methods may be added in future releases */ |
757 | }; |
758 | |
759 | /* |
760 | ** CAPI3REF: Standard File Control Opcodes |
761 | ** |
762 | ** These integer constants are opcodes for the xFileControl method |
763 | ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] |
764 | ** interface. |
765 | ** |
766 | ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This |
767 | ** opcode causes the xFileControl method to write the current state of |
768 | ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], |
769 | ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) |
770 | ** into an integer that the pArg argument points to. This capability |
771 | ** is used during testing and only needs to be supported when SQLITE_TEST |
772 | ** is defined. |
773 | ** <ul> |
774 | ** <li>[[SQLITE_FCNTL_SIZE_HINT]] |
775 | ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS |
776 | ** layer a hint of how large the database file will grow to be during the |
777 | ** current transaction. This hint is not guaranteed to be accurate but it |
778 | ** is often close. The underlying VFS might choose to preallocate database |
779 | ** file space based on this hint in order to help writes to the database |
780 | ** file run faster. |
781 | ** |
782 | ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] |
783 | ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS |
784 | ** extends and truncates the database file in chunks of a size specified |
785 | ** by the user. The fourth argument to [sqlite3_file_control()] should |
786 | ** point to an integer (type int) containing the new chunk-size to use |
787 | ** for the nominated database. Allocating database file space in large |
788 | ** chunks (say 1MB at a time), may reduce file-system fragmentation and |
789 | ** improve performance on some systems. |
790 | ** |
791 | ** <li>[[SQLITE_FCNTL_FILE_POINTER]] |
792 | ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer |
793 | ** to the [sqlite3_file] object associated with a particular database |
794 | ** connection. See the [sqlite3_file_control()] documentation for |
795 | ** additional information. |
796 | ** |
797 | ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] |
798 | ** No longer in use. |
799 | ** |
800 | ** <li>[[SQLITE_FCNTL_SYNC]] |
801 | ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and |
802 | ** sent to the VFS immediately before the xSync method is invoked on a |
803 | ** database file descriptor. Or, if the xSync method is not invoked |
804 | ** because the user has configured SQLite with |
805 | ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place |
806 | ** of the xSync method. In most cases, the pointer argument passed with |
807 | ** this file-control is NULL. However, if the database file is being synced |
808 | ** as part of a multi-database commit, the argument points to a nul-terminated |
809 | ** string containing the transactions master-journal file name. VFSes that |
810 | ** do not need this signal should silently ignore this opcode. Applications |
811 | ** should not call [sqlite3_file_control()] with this opcode as doing so may |
812 | ** disrupt the operation of the specialized VFSes that do require it. |
813 | ** |
814 | ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] |
815 | ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite |
816 | ** and sent to the VFS after a transaction has been committed immediately |
817 | ** but before the database is unlocked. VFSes that do not need this signal |
818 | ** should silently ignore this opcode. Applications should not call |
819 | ** [sqlite3_file_control()] with this opcode as doing so may disrupt the |
820 | ** operation of the specialized VFSes that do require it. |
821 | ** |
822 | ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] |
823 | ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic |
824 | ** retry counts and intervals for certain disk I/O operations for the |
825 | ** windows [VFS] in order to provide robustness in the presence of |
826 | ** anti-virus programs. By default, the windows VFS will retry file read, |
827 | ** file write, and file delete operations up to 10 times, with a delay |
828 | ** of 25 milliseconds before the first retry and with the delay increasing |
829 | ** by an additional 25 milliseconds with each subsequent retry. This |
830 | ** opcode allows these two values (10 retries and 25 milliseconds of delay) |
831 | ** to be adjusted. The values are changed for all database connections |
832 | ** within the same process. The argument is a pointer to an array of two |
833 | ** integers where the first integer i the new retry count and the second |
834 | ** integer is the delay. If either integer is negative, then the setting |
835 | ** is not changed but instead the prior value of that setting is written |
836 | ** into the array entry, allowing the current retry settings to be |
837 | ** interrogated. The zDbName parameter is ignored. |
838 | ** |
839 | ** <li>[[SQLITE_FCNTL_PERSIST_WAL]] |
840 | ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the |
841 | ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary |
842 | ** write ahead log and shared memory files used for transaction control |
843 | ** are automatically deleted when the latest connection to the database |
844 | ** closes. Setting persistent WAL mode causes those files to persist after |
845 | ** close. Persisting the files is useful when other processes that do not |
846 | ** have write permission on the directory containing the database file want |
847 | ** to read the database file, as the WAL and shared memory files must exist |
848 | ** in order for the database to be readable. The fourth parameter to |
849 | ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. |
850 | ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent |
851 | ** WAL mode. If the integer is -1, then it is overwritten with the current |
852 | ** WAL persistence setting. |
853 | ** |
854 | ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] |
855 | ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the |
856 | ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting |
857 | ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the |
858 | ** xDeviceCharacteristics methods. The fourth parameter to |
859 | ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. |
860 | ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage |
861 | ** mode. If the integer is -1, then it is overwritten with the current |
862 | ** zero-damage mode setting. |
863 | ** |
864 | ** <li>[[SQLITE_FCNTL_OVERWRITE]] |
865 | ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening |
866 | ** a write transaction to indicate that, unless it is rolled back for some |
867 | ** reason, the entire database file will be overwritten by the current |
868 | ** transaction. This is used by VACUUM operations. |
869 | ** |
870 | ** <li>[[SQLITE_FCNTL_VFSNAME]] |
871 | ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of |
872 | ** all [VFSes] in the VFS stack. The names are of all VFS shims and the |
873 | ** final bottom-level VFS are written into memory obtained from |
874 | ** [sqlite3_malloc()] and the result is stored in the char* variable |
875 | ** that the fourth parameter of [sqlite3_file_control()] points to. |
876 | ** The caller is responsible for freeing the memory when done. As with |
877 | ** all file-control actions, there is no guarantee that this will actually |
878 | ** do anything. Callers should initialize the char* variable to a NULL |
879 | ** pointer in case this file-control is not implemented. This file-control |
880 | ** is intended for diagnostic use only. |
881 | ** |
882 | ** <li>[[SQLITE_FCNTL_PRAGMA]] |
883 | ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] |
884 | ** file control is sent to the open [sqlite3_file] object corresponding |
885 | ** to the database file to which the pragma statement refers. ^The argument |
886 | ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of |
887 | ** pointers to strings (char**) in which the second element of the array |
888 | ** is the name of the pragma and the third element is the argument to the |
889 | ** pragma or NULL if the pragma has no argument. ^The handler for an |
890 | ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element |
891 | ** of the char** argument point to a string obtained from [sqlite3_mprintf()] |
892 | ** or the equivalent and that string will become the result of the pragma or |
893 | ** the error message if the pragma fails. ^If the |
894 | ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal |
895 | ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] |
896 | ** file control returns [SQLITE_OK], then the parser assumes that the |
897 | ** VFS has handled the PRAGMA itself and the parser generates a no-op |
898 | ** prepared statement. ^If the [SQLITE_FCNTL_PRAGMA] file control returns |
899 | ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means |
900 | ** that the VFS encountered an error while handling the [PRAGMA] and the |
901 | ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] |
902 | ** file control occurs at the beginning of pragma statement analysis and so |
903 | ** it is able to override built-in [PRAGMA] statements. |
904 | ** |
905 | ** <li>[[SQLITE_FCNTL_BUSYHANDLER]] |
906 | ** ^The [SQLITE_FCNTL_BUSYHANDLER] |
907 | ** file-control may be invoked by SQLite on the database file handle |
908 | ** shortly after it is opened in order to provide a custom VFS with access |
909 | ** to the connections busy-handler callback. The argument is of type (void **) |
910 | ** - an array of two (void *) values. The first (void *) actually points |
911 | ** to a function of type (int (*)(void *)). In order to invoke the connections |
912 | ** busy-handler, this function should be invoked with the second (void *) in |
913 | ** the array as the only argument. If it returns non-zero, then the operation |
914 | ** should be retried. If it returns zero, the custom VFS should abandon the |
915 | ** current operation. |
916 | ** |
917 | ** <li>[[SQLITE_FCNTL_TEMPFILENAME]] |
918 | ** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control |
919 | ** to have SQLite generate a |
920 | ** temporary filename using the same algorithm that is followed to generate |
921 | ** temporary filenames for TEMP tables and other internal uses. The |
922 | ** argument should be a char** which will be filled with the filename |
923 | ** written into memory obtained from [sqlite3_malloc()]. The caller should |
924 | ** invoke [sqlite3_free()] on the result to avoid a memory leak. |
925 | ** |
926 | ** <li>[[SQLITE_FCNTL_MMAP_SIZE]] |
927 | ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the |
928 | ** maximum number of bytes that will be used for memory-mapped I/O. |
929 | ** The argument is a pointer to a value of type sqlite3_int64 that |
930 | ** is an advisory maximum number of bytes in the file to memory map. The |
931 | ** pointer is overwritten with the old value. The limit is not changed if |
932 | ** the value originally pointed to is negative, and so the current limit |
933 | ** can be queried by passing in a pointer to a negative number. This |
934 | ** file-control is used internally to implement [PRAGMA mmap_size]. |
935 | ** |
936 | ** <li>[[SQLITE_FCNTL_TRACE]] |
937 | ** The [SQLITE_FCNTL_TRACE] file control provides advisory information |
938 | ** to the VFS about what the higher layers of the SQLite stack are doing. |
939 | ** This file control is used by some VFS activity tracing [shims]. |
940 | ** The argument is a zero-terminated string. Higher layers in the |
941 | ** SQLite stack may generate instances of this file control if |
942 | ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. |
943 | ** |
944 | ** <li>[[SQLITE_FCNTL_HAS_MOVED]] |
945 | ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a |
946 | ** pointer to an integer and it writes a boolean into that integer depending |
947 | ** on whether or not the file has been renamed, moved, or deleted since it |
948 | ** was first opened. |
949 | ** |
950 | ** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] |
951 | ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This |
952 | ** opcode causes the xFileControl method to swap the file handle with the one |
953 | ** pointed to by the pArg argument. This capability is used during testing |
954 | ** and only needs to be supported when SQLITE_TEST is defined. |
955 | ** |
956 | ** </ul> |
957 | */ |
958 | #define SQLITE_FCNTL_LOCKSTATE 1 |
959 | #define SQLITE_GET_LOCKPROXYFILE 2 |
960 | #define SQLITE_SET_LOCKPROXYFILE 3 |
961 | #define SQLITE_LAST_ERRNO 4 |
962 | #define SQLITE_FCNTL_SIZE_HINT 5 |
963 | #define SQLITE_FCNTL_CHUNK_SIZE 6 |
964 | #define SQLITE_FCNTL_FILE_POINTER 7 |
965 | #define SQLITE_FCNTL_SYNC_OMITTED 8 |
966 | #define SQLITE_FCNTL_WIN32_AV_RETRY 9 |
967 | #define SQLITE_FCNTL_PERSIST_WAL 10 |
968 | #define SQLITE_FCNTL_OVERWRITE 11 |
969 | #define SQLITE_FCNTL_VFSNAME 12 |
970 | #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 |
971 | #define SQLITE_FCNTL_PRAGMA 14 |
972 | #define SQLITE_FCNTL_BUSYHANDLER 15 |
973 | #define SQLITE_FCNTL_TEMPFILENAME 16 |
974 | #define SQLITE_FCNTL_MMAP_SIZE 18 |
975 | #define SQLITE_FCNTL_TRACE 19 |
976 | #define SQLITE_FCNTL_HAS_MOVED 20 |
977 | #define SQLITE_FCNTL_SYNC 21 |
978 | #define SQLITE_FCNTL_COMMIT_PHASETWO 22 |
979 | #define SQLITE_FCNTL_WIN32_SET_HANDLE 23 |
980 | |
981 | /* |
982 | ** CAPI3REF: Mutex Handle |
983 | ** |
984 | ** The mutex module within SQLite defines [sqlite3_mutex] to be an |
985 | ** abstract type for a mutex object. The SQLite core never looks |
986 | ** at the internal representation of an [sqlite3_mutex]. It only |
987 | ** deals with pointers to the [sqlite3_mutex] object. |
988 | ** |
989 | ** Mutexes are created using [sqlite3_mutex_alloc()]. |
990 | */ |
991 | typedef struct sqlite3_mutex sqlite3_mutex; |
992 | |
993 | /* |
994 | ** CAPI3REF: OS Interface Object |
995 | ** |
996 | ** An instance of the sqlite3_vfs object defines the interface between |
997 | ** the SQLite core and the underlying operating system. The "vfs" |
998 | ** in the name of the object stands for "virtual file system". See |
999 | ** the [VFS | VFS documentation] for further information. |
1000 | ** |
1001 | ** The value of the iVersion field is initially 1 but may be larger in |
1002 | ** future versions of SQLite. Additional fields may be appended to this |
1003 | ** object when the iVersion value is increased. Note that the structure |
1004 | ** of the sqlite3_vfs object changes in the transaction between |
1005 | ** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not |
1006 | ** modified. |
1007 | ** |
1008 | ** The szOsFile field is the size of the subclassed [sqlite3_file] |
1009 | ** structure used by this VFS. mxPathname is the maximum length of |
1010 | ** a pathname in this VFS. |
1011 | ** |
1012 | ** Registered sqlite3_vfs objects are kept on a linked list formed by |
1013 | ** the pNext pointer. The [sqlite3_vfs_register()] |
1014 | ** and [sqlite3_vfs_unregister()] interfaces manage this list |
1015 | ** in a thread-safe way. The [sqlite3_vfs_find()] interface |
1016 | ** searches the list. Neither the application code nor the VFS |
1017 | ** implementation should use the pNext pointer. |
1018 | ** |
1019 | ** The pNext field is the only field in the sqlite3_vfs |
1020 | ** structure that SQLite will ever modify. SQLite will only access |
1021 | ** or modify this field while holding a particular static mutex. |
1022 | ** The application should never modify anything within the sqlite3_vfs |
1023 | ** object once the object has been registered. |
1024 | ** |
1025 | ** The zName field holds the name of the VFS module. The name must |
1026 | ** be unique across all VFS modules. |
1027 | ** |
1028 | ** [[sqlite3_vfs.xOpen]] |
1029 | ** ^SQLite guarantees that the zFilename parameter to xOpen |
1030 | ** is either a NULL pointer or string obtained |
1031 | ** from xFullPathname() with an optional suffix added. |
1032 | ** ^If a suffix is added to the zFilename parameter, it will |
1033 | ** consist of a single "-" character followed by no more than |
1034 | ** 11 alphanumeric and/or "-" characters. |
1035 | ** ^SQLite further guarantees that |
1036 | ** the string will be valid and unchanged until xClose() is |
1037 | ** called. Because of the previous sentence, |
1038 | ** the [sqlite3_file] can safely store a pointer to the |
1039 | ** filename if it needs to remember the filename for some reason. |
1040 | ** If the zFilename parameter to xOpen is a NULL pointer then xOpen |
1041 | ** must invent its own temporary name for the file. ^Whenever the |
1042 | ** xFilename parameter is NULL it will also be the case that the |
1043 | ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. |
1044 | ** |
1045 | ** The flags argument to xOpen() includes all bits set in |
1046 | ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] |
1047 | ** or [sqlite3_open16()] is used, then flags includes at least |
1048 | ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. |
1049 | ** If xOpen() opens a file read-only then it sets *pOutFlags to |
1050 | ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. |
1051 | ** |
1052 | ** ^(SQLite will also add one of the following flags to the xOpen() |
1053 | ** call, depending on the object being opened: |
1054 | ** |
1055 | ** <ul> |
1056 | ** <li> [SQLITE_OPEN_MAIN_DB] |
1057 | ** <li> [SQLITE_OPEN_MAIN_JOURNAL] |
1058 | ** <li> [SQLITE_OPEN_TEMP_DB] |
1059 | ** <li> [SQLITE_OPEN_TEMP_JOURNAL] |
1060 | ** <li> [SQLITE_OPEN_TRANSIENT_DB] |
1061 | ** <li> [SQLITE_OPEN_SUBJOURNAL] |
1062 | ** <li> [SQLITE_OPEN_MASTER_JOURNAL] |
1063 | ** <li> [SQLITE_OPEN_WAL] |
1064 | ** </ul>)^ |
1065 | ** |
1066 | ** The file I/O implementation can use the object type flags to |
1067 | ** change the way it deals with files. For example, an application |
1068 | ** that does not care about crash recovery or rollback might make |
1069 | ** the open of a journal file a no-op. Writes to this journal would |
1070 | ** also be no-ops, and any attempt to read the journal would return |
1071 | ** SQLITE_IOERR. Or the implementation might recognize that a database |
1072 | ** file will be doing page-aligned sector reads and writes in a random |
1073 | ** order and set up its I/O subsystem accordingly. |
1074 | ** |
1075 | ** SQLite might also add one of the following flags to the xOpen method: |
1076 | ** |
1077 | ** <ul> |
1078 | ** <li> [SQLITE_OPEN_DELETEONCLOSE] |
1079 | ** <li> [SQLITE_OPEN_EXCLUSIVE] |
1080 | ** </ul> |
1081 | ** |
1082 | ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be |
1083 | ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] |
1084 | ** will be set for TEMP databases and their journals, transient |
1085 | ** databases, and subjournals. |
1086 | ** |
1087 | ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction |
1088 | ** with the [SQLITE_OPEN_CREATE] flag, which are both directly |
1089 | ** analogous to the O_EXCL and O_CREAT flags of the POSIX open() |
1090 | ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the |
1091 | ** SQLITE_OPEN_CREATE, is used to indicate that file should always |
1092 | ** be created, and that it is an error if it already exists. |
1093 | ** It is <i>not</i> used to indicate the file should be opened |
1094 | ** for exclusive access. |
1095 | ** |
1096 | ** ^At least szOsFile bytes of memory are allocated by SQLite |
1097 | ** to hold the [sqlite3_file] structure passed as the third |
1098 | ** argument to xOpen. The xOpen method does not have to |
1099 | ** allocate the structure; it should just fill it in. Note that |
1100 | ** the xOpen method must set the sqlite3_file.pMethods to either |
1101 | ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do |
1102 | ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods |
1103 | ** element will be valid after xOpen returns regardless of the success |
1104 | ** or failure of the xOpen call. |
1105 | ** |
1106 | ** [[sqlite3_vfs.xAccess]] |
1107 | ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] |
1108 | ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to |
1109 | ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] |
1110 | ** to test whether a file is at least readable. The file can be a |
1111 | ** directory. |
1112 | ** |
1113 | ** ^SQLite will always allocate at least mxPathname+1 bytes for the |
1114 | ** output buffer xFullPathname. The exact size of the output buffer |
1115 | ** is also passed as a parameter to both methods. If the output buffer |
1116 | ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is |
1117 | ** handled as a fatal error by SQLite, vfs implementations should endeavor |
1118 | ** to prevent this by setting mxPathname to a sufficiently large value. |
1119 | ** |
1120 | ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() |
1121 | ** interfaces are not strictly a part of the filesystem, but they are |
1122 | ** included in the VFS structure for completeness. |
1123 | ** The xRandomness() function attempts to return nBytes bytes |
1124 | ** of good-quality randomness into zOut. The return value is |
1125 | ** the actual number of bytes of randomness obtained. |
1126 | ** The xSleep() method causes the calling thread to sleep for at |
1127 | ** least the number of microseconds given. ^The xCurrentTime() |
1128 | ** method returns a Julian Day Number for the current date and time as |
1129 | ** a floating point value. |
1130 | ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian |
1131 | ** Day Number multiplied by 86400000 (the number of milliseconds in |
1132 | ** a 24-hour day). |
1133 | ** ^SQLite will use the xCurrentTimeInt64() method to get the current |
1134 | ** date and time if that method is available (if iVersion is 2 or |
1135 | ** greater and the function pointer is not NULL) and will fall back |
1136 | ** to xCurrentTime() if xCurrentTimeInt64() is unavailable. |
1137 | ** |
1138 | ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces |
1139 | ** are not used by the SQLite core. These optional interfaces are provided |
1140 | ** by some VFSes to facilitate testing of the VFS code. By overriding |
1141 | ** system calls with functions under its control, a test program can |
1142 | ** simulate faults and error conditions that would otherwise be difficult |
1143 | ** or impossible to induce. The set of system calls that can be overridden |
1144 | ** varies from one VFS to another, and from one version of the same VFS to the |
1145 | ** next. Applications that use these interfaces must be prepared for any |
1146 | ** or all of these interfaces to be NULL or for their behavior to change |
1147 | ** from one release to the next. Applications must not attempt to access |
1148 | ** any of these methods if the iVersion of the VFS is less than 3. |
1149 | */ |
1150 | typedef struct sqlite3_vfs sqlite3_vfs; |
1151 | typedef void (*sqlite3_syscall_ptr)(void); |
1152 | struct sqlite3_vfs { |
1153 | int iVersion; /* Structure version number (currently 3) */ |
1154 | int szOsFile; /* Size of subclassed sqlite3_file */ |
1155 | int mxPathname; /* Maximum file pathname length */ |
1156 | sqlite3_vfs *pNext; /* Next registered VFS */ |
1157 | const char *zName; /* Name of this virtual file system */ |
1158 | void *pAppData; /* Pointer to application-specific data */ |
1159 | int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, |
1160 | int flags, int *pOutFlags); |
1161 | int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); |
1162 | int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); |
1163 | int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); |
1164 | void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); |
1165 | void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); |
1166 | void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); |
1167 | void (*xDlClose)(sqlite3_vfs*, void*); |
1168 | int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); |
1169 | int (*xSleep)(sqlite3_vfs*, int microseconds); |
1170 | int (*xCurrentTime)(sqlite3_vfs*, double*); |
1171 | int (*xGetLastError)(sqlite3_vfs*, int, char *); |
1172 | /* |
1173 | ** The methods above are in version 1 of the sqlite_vfs object |
1174 | ** definition. Those that follow are added in version 2 or later |
1175 | */ |
1176 | int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); |
1177 | /* |
1178 | ** The methods above are in versions 1 and 2 of the sqlite_vfs object. |
1179 | ** Those below are for version 3 and greater. |
1180 | */ |
1181 | int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); |
1182 | sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); |
1183 | const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); |
1184 | /* |
1185 | ** The methods above are in versions 1 through 3 of the sqlite_vfs object. |
1186 | ** New fields may be appended in figure versions. The iVersion |
1187 | ** value will increment whenever this happens. |
1188 | */ |
1189 | }; |
1190 | |
1191 | /* |
1192 | ** CAPI3REF: Flags for the xAccess VFS method |
1193 | ** |
1194 | ** These integer constants can be used as the third parameter to |
1195 | ** the xAccess method of an [sqlite3_vfs] object. They determine |
1196 | ** what kind of permissions the xAccess method is looking for. |
1197 | ** With SQLITE_ACCESS_EXISTS, the xAccess method |
1198 | ** simply checks whether the file exists. |
1199 | ** With SQLITE_ACCESS_READWRITE, the xAccess method |
1200 | ** checks whether the named directory is both readable and writable |
1201 | ** (in other words, if files can be added, removed, and renamed within |
1202 | ** the directory). |
1203 | ** The SQLITE_ACCESS_READWRITE constant is currently used only by the |
1204 | ** [temp_store_directory pragma], though this could change in a future |
1205 | ** release of SQLite. |
1206 | ** With SQLITE_ACCESS_READ, the xAccess method |
1207 | ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is |
1208 | ** currently unused, though it might be used in a future release of |
1209 | ** SQLite. |
1210 | */ |
1211 | #define SQLITE_ACCESS_EXISTS 0 |
1212 | #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ |
1213 | #define SQLITE_ACCESS_READ 2 /* Unused */ |
1214 | |
1215 | /* |
1216 | ** CAPI3REF: Flags for the xShmLock VFS method |
1217 | ** |
1218 | ** These integer constants define the various locking operations |
1219 | ** allowed by the xShmLock method of [sqlite3_io_methods]. The |
1220 | ** following are the only legal combinations of flags to the |
1221 | ** xShmLock method: |
1222 | ** |
1223 | ** <ul> |
1224 | ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED |
1225 | ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE |
1226 | ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED |
1227 | ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE |
1228 | ** </ul> |
1229 | ** |
1230 | ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as |
1231 | ** was given no the corresponding lock. |
1232 | ** |
1233 | ** The xShmLock method can transition between unlocked and SHARED or |
1234 | ** between unlocked and EXCLUSIVE. It cannot transition between SHARED |
1235 | ** and EXCLUSIVE. |
1236 | */ |
1237 | #define SQLITE_SHM_UNLOCK 1 |
1238 | #define SQLITE_SHM_LOCK 2 |
1239 | #define SQLITE_SHM_SHARED 4 |
1240 | #define SQLITE_SHM_EXCLUSIVE 8 |
1241 | |
1242 | /* |
1243 | ** CAPI3REF: Maximum xShmLock index |
1244 | ** |
1245 | ** The xShmLock method on [sqlite3_io_methods] may use values |
1246 | ** between 0 and this upper bound as its "offset" argument. |
1247 | ** The SQLite core will never attempt to acquire or release a |
1248 | ** lock outside of this range |
1249 | */ |
1250 | #define SQLITE_SHM_NLOCK 8 |
1251 | |
1252 | |
1253 | /* |
1254 | ** CAPI3REF: Initialize The SQLite Library |
1255 | ** |
1256 | ** ^The sqlite3_initialize() routine initializes the |
1257 | ** SQLite library. ^The sqlite3_shutdown() routine |
1258 | ** deallocates any resources that were allocated by sqlite3_initialize(). |
1259 | ** These routines are designed to aid in process initialization and |
1260 | ** shutdown on embedded systems. Workstation applications using |
1261 | ** SQLite normally do not need to invoke either of these routines. |
1262 | ** |
1263 | ** A call to sqlite3_initialize() is an "effective" call if it is |
1264 | ** the first time sqlite3_initialize() is invoked during the lifetime of |
1265 | ** the process, or if it is the first time sqlite3_initialize() is invoked |
1266 | ** following a call to sqlite3_shutdown(). ^(Only an effective call |
1267 | ** of sqlite3_initialize() does any initialization. All other calls |
1268 | ** are harmless no-ops.)^ |
1269 | ** |
1270 | ** A call to sqlite3_shutdown() is an "effective" call if it is the first |
1271 | ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only |
1272 | ** an effective call to sqlite3_shutdown() does any deinitialization. |
1273 | ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ |
1274 | ** |
1275 | ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() |
1276 | ** is not. The sqlite3_shutdown() interface must only be called from a |
1277 | ** single thread. All open [database connections] must be closed and all |
1278 | ** other SQLite resources must be deallocated prior to invoking |
1279 | ** sqlite3_shutdown(). |
1280 | ** |
1281 | ** Among other things, ^sqlite3_initialize() will invoke |
1282 | ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() |
1283 | ** will invoke sqlite3_os_end(). |
1284 | ** |
1285 | ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. |
1286 | ** ^If for some reason, sqlite3_initialize() is unable to initialize |
1287 | ** the library (perhaps it is unable to allocate a needed resource such |
1288 | ** as a mutex) it returns an [error code] other than [SQLITE_OK]. |
1289 | ** |
1290 | ** ^The sqlite3_initialize() routine is called internally by many other |
1291 | ** SQLite interfaces so that an application usually does not need to |
1292 | ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] |
1293 | ** calls sqlite3_initialize() so the SQLite library will be automatically |
1294 | ** initialized when [sqlite3_open()] is called if it has not be initialized |
1295 | ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] |
1296 | ** compile-time option, then the automatic calls to sqlite3_initialize() |
1297 | ** are omitted and the application must call sqlite3_initialize() directly |
1298 | ** prior to using any other SQLite interface. For maximum portability, |
1299 | ** it is recommended that applications always invoke sqlite3_initialize() |
1300 | ** directly prior to using any other SQLite interface. Future releases |
1301 | ** of SQLite may require this. In other words, the behavior exhibited |
1302 | ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the |
1303 | ** default behavior in some future release of SQLite. |
1304 | ** |
1305 | ** The sqlite3_os_init() routine does operating-system specific |
1306 | ** initialization of the SQLite library. The sqlite3_os_end() |
1307 | ** routine undoes the effect of sqlite3_os_init(). Typical tasks |
1308 | ** performed by these routines include allocation or deallocation |
1309 | ** of static resources, initialization of global variables, |
1310 | ** setting up a default [sqlite3_vfs] module, or setting up |
1311 | ** a default configuration using [sqlite3_config()]. |
1312 | ** |
1313 | ** The application should never invoke either sqlite3_os_init() |
1314 | ** or sqlite3_os_end() directly. The application should only invoke |
1315 | ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() |
1316 | ** interface is called automatically by sqlite3_initialize() and |
1317 | ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate |
1318 | ** implementations for sqlite3_os_init() and sqlite3_os_end() |
1319 | ** are built into SQLite when it is compiled for Unix, Windows, or OS/2. |
1320 | ** When [custom builds | built for other platforms] |
1321 | ** (using the [SQLITE_OS_OTHER=1] compile-time |
1322 | ** option) the application must supply a suitable implementation for |
1323 | ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied |
1324 | ** implementation of sqlite3_os_init() or sqlite3_os_end() |
1325 | ** must return [SQLITE_OK] on success and some other [error code] upon |
1326 | ** failure. |
1327 | */ |
1328 | SQLITE_API int sqlite3_initialize(void); |
1329 | SQLITE_API int sqlite3_shutdown(void); |
1330 | SQLITE_API int sqlite3_os_init(void); |
1331 | SQLITE_API int sqlite3_os_end(void); |
1332 | |
1333 | /* |
1334 | ** CAPI3REF: Configuring The SQLite Library |
1335 | ** |
1336 | ** The sqlite3_config() interface is used to make global configuration |
1337 | ** changes to SQLite in order to tune SQLite to the specific needs of |
1338 | ** the application. The default configuration is recommended for most |
1339 | ** applications and so this routine is usually not necessary. It is |
1340 | ** provided to support rare applications with unusual needs. |
1341 | ** |
1342 | ** The sqlite3_config() interface is not threadsafe. The application |
1343 | ** must insure that no other SQLite interfaces are invoked by other |
1344 | ** threads while sqlite3_config() is running. Furthermore, sqlite3_config() |
1345 | ** may only be invoked prior to library initialization using |
1346 | ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. |
1347 | ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before |
1348 | ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. |
1349 | ** Note, however, that ^sqlite3_config() can be called as part of the |
1350 | ** implementation of an application-defined [sqlite3_os_init()]. |
1351 | ** |
1352 | ** The first argument to sqlite3_config() is an integer |
1353 | ** [configuration option] that determines |
1354 | ** what property of SQLite is to be configured. Subsequent arguments |
1355 | ** vary depending on the [configuration option] |
1356 | ** in the first argument. |
1357 | ** |
1358 | ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. |
1359 | ** ^If the option is unknown or SQLite is unable to set the option |
1360 | ** then this routine returns a non-zero [error code]. |
1361 | */ |
1362 | SQLITE_API int sqlite3_config(int, ...); |
1363 | |
1364 | /* |
1365 | ** CAPI3REF: Configure database connections |
1366 | ** |
1367 | ** The sqlite3_db_config() interface is used to make configuration |
1368 | ** changes to a [database connection]. The interface is similar to |
1369 | ** [sqlite3_config()] except that the changes apply to a single |
1370 | ** [database connection] (specified in the first argument). |
1371 | ** |
1372 | ** The second argument to sqlite3_db_config(D,V,...) is the |
1373 | ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code |
1374 | ** that indicates what aspect of the [database connection] is being configured. |
1375 | ** Subsequent arguments vary depending on the configuration verb. |
1376 | ** |
1377 | ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if |
1378 | ** the call is considered successful. |
1379 | */ |
1380 | SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...); |
1381 | |
1382 | /* |
1383 | ** CAPI3REF: Memory Allocation Routines |
1384 | ** |
1385 | ** An instance of this object defines the interface between SQLite |
1386 | ** and low-level memory allocation routines. |
1387 | ** |
1388 | ** This object is used in only one place in the SQLite interface. |
1389 | ** A pointer to an instance of this object is the argument to |
1390 | ** [sqlite3_config()] when the configuration option is |
1391 | ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. |
1392 | ** By creating an instance of this object |
1393 | ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) |
1394 | ** during configuration, an application can specify an alternative |
1395 | ** memory allocation subsystem for SQLite to use for all of its |
1396 | ** dynamic memory needs. |
1397 | ** |
1398 | ** Note that SQLite comes with several [built-in memory allocators] |
1399 | ** that are perfectly adequate for the overwhelming majority of applications |
1400 | ** and that this object is only useful to a tiny minority of applications |
1401 | ** with specialized memory allocation requirements. This object is |
1402 | ** also used during testing of SQLite in order to specify an alternative |
1403 | ** memory allocator that simulates memory out-of-memory conditions in |
1404 | ** order to verify that SQLite recovers gracefully from such |
1405 | ** conditions. |
1406 | ** |
1407 | ** The xMalloc, xRealloc, and xFree methods must work like the |
1408 | ** malloc(), realloc() and free() functions from the standard C library. |
1409 | ** ^SQLite guarantees that the second argument to |
1410 | ** xRealloc is always a value returned by a prior call to xRoundup. |
1411 | ** |
1412 | ** xSize should return the allocated size of a memory allocation |
1413 | ** previously obtained from xMalloc or xRealloc. The allocated size |
1414 | ** is always at least as big as the requested size but may be larger. |
1415 | ** |
1416 | ** The xRoundup method returns what would be the allocated size of |
1417 | ** a memory allocation given a particular requested size. Most memory |
1418 | ** allocators round up memory allocations at least to the next multiple |
1419 | ** of 8. Some allocators round up to a larger multiple or to a power of 2. |
1420 | ** Every memory allocation request coming in through [sqlite3_malloc()] |
1421 | ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, |
1422 | ** that causes the corresponding memory allocation to fail. |
1423 | ** |
1424 | ** The xInit method initializes the memory allocator. For example, |
1425 | ** it might allocate any require mutexes or initialize internal data |
1426 | ** structures. The xShutdown method is invoked (indirectly) by |
1427 | ** [sqlite3_shutdown()] and should deallocate any resources acquired |
1428 | ** by xInit. The pAppData pointer is used as the only parameter to |
1429 | ** xInit and xShutdown. |
1430 | ** |
1431 | ** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes |
1432 | ** the xInit method, so the xInit method need not be threadsafe. The |
1433 | ** xShutdown method is only called from [sqlite3_shutdown()] so it does |
1434 | ** not need to be threadsafe either. For all other methods, SQLite |
1435 | ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the |
1436 | ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which |
1437 | ** it is by default) and so the methods are automatically serialized. |
1438 | ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other |
1439 | ** methods must be threadsafe or else make their own arrangements for |
1440 | ** serialization. |
1441 | ** |
1442 | ** SQLite will never invoke xInit() more than once without an intervening |
1443 | ** call to xShutdown(). |
1444 | */ |
1445 | typedef struct sqlite3_mem_methods sqlite3_mem_methods; |
1446 | struct sqlite3_mem_methods { |
1447 | void *(*xMalloc)(int); /* Memory allocation function */ |
1448 | void (*xFree)(void*); /* Free a prior allocation */ |
1449 | void *(*xRealloc)(void*,int); /* Resize an allocation */ |
1450 | int (*xSize)(void*); /* Return the size of an allocation */ |
1451 | int (*xRoundup)(int); /* Round up request size to allocation size */ |
1452 | int (*xInit)(void*); /* Initialize the memory allocator */ |
1453 | void (*xShutdown)(void*); /* Deinitialize the memory allocator */ |
1454 | void *pAppData; /* Argument to xInit() and xShutdown() */ |
1455 | }; |
1456 | |
1457 | /* |
1458 | ** CAPI3REF: Configuration Options |
1459 | ** KEYWORDS: {configuration option} |
1460 | ** |
1461 | ** These constants are the available integer configuration options that |
1462 | ** can be passed as the first argument to the [sqlite3_config()] interface. |
1463 | ** |
1464 | ** New configuration options may be added in future releases of SQLite. |
1465 | ** Existing configuration options might be discontinued. Applications |
1466 | ** should check the return code from [sqlite3_config()] to make sure that |
1467 | ** the call worked. The [sqlite3_config()] interface will return a |
1468 | ** non-zero [error code] if a discontinued or unsupported configuration option |
1469 | ** is invoked. |
1470 | ** |
1471 | ** <dl> |
1472 | ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> |
1473 | ** <dd>There are no arguments to this option. ^This option sets the |
1474 | ** [threading mode] to Single-thread. In other words, it disables |
1475 | ** all mutexing and puts SQLite into a mode where it can only be used |
1476 | ** by a single thread. ^If SQLite is compiled with |
1477 | ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then |
1478 | ** it is not possible to change the [threading mode] from its default |
1479 | ** value of Single-thread and so [sqlite3_config()] will return |
1480 | ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD |
1481 | ** configuration option.</dd> |
1482 | ** |
1483 | ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> |
1484 | ** <dd>There are no arguments to this option. ^This option sets the |
1485 | ** [threading mode] to Multi-thread. In other words, it disables |
1486 | ** mutexing on [database connection] and [prepared statement] objects. |
1487 | ** The application is responsible for serializing access to |
1488 | ** [database connections] and [prepared statements]. But other mutexes |
1489 | ** are enabled so that SQLite will be safe to use in a multi-threaded |
1490 | ** environment as long as no two threads attempt to use the same |
1491 | ** [database connection] at the same time. ^If SQLite is compiled with |
1492 | ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then |
1493 | ** it is not possible to set the Multi-thread [threading mode] and |
1494 | ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the |
1495 | ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> |
1496 | ** |
1497 | ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> |
1498 | ** <dd>There are no arguments to this option. ^This option sets the |
1499 | ** [threading mode] to Serialized. In other words, this option enables |
1500 | ** all mutexes including the recursive |
1501 | ** mutexes on [database connection] and [prepared statement] objects. |
1502 | ** In this mode (which is the default when SQLite is compiled with |
1503 | ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access |
1504 | ** to [database connections] and [prepared statements] so that the |
1505 | ** application is free to use the same [database connection] or the |
1506 | ** same [prepared statement] in different threads at the same time. |
1507 | ** ^If SQLite is compiled with |
1508 | ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then |
1509 | ** it is not possible to set the Serialized [threading mode] and |
1510 | ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the |
1511 | ** SQLITE_CONFIG_SERIALIZED configuration option.</dd> |
1512 | ** |
1513 | ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> |
1514 | ** <dd> ^(This option takes a single argument which is a pointer to an |
1515 | ** instance of the [sqlite3_mem_methods] structure. The argument specifies |
1516 | ** alternative low-level memory allocation routines to be used in place of |
1517 | ** the memory allocation routines built into SQLite.)^ ^SQLite makes |
1518 | ** its own private copy of the content of the [sqlite3_mem_methods] structure |
1519 | ** before the [sqlite3_config()] call returns.</dd> |
1520 | ** |
1521 | ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> |
1522 | ** <dd> ^(This option takes a single argument which is a pointer to an |
1523 | ** instance of the [sqlite3_mem_methods] structure. The [sqlite3_mem_methods] |
1524 | ** structure is filled with the currently defined memory allocation routines.)^ |
1525 | ** This option can be used to overload the default memory allocation |
1526 | ** routines with a wrapper that simulations memory allocation failure or |
1527 | ** tracks memory usage, for example. </dd> |
1528 | ** |
1529 | ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> |
1530 | ** <dd> ^This option takes single argument of type int, interpreted as a |
1531 | ** boolean, which enables or disables the collection of memory allocation |
1532 | ** statistics. ^(When memory allocation statistics are disabled, the |
1533 | ** following SQLite interfaces become non-operational: |
1534 | ** <ul> |
1535 | ** <li> [sqlite3_memory_used()] |
1536 | ** <li> [sqlite3_memory_highwater()] |
1537 | ** <li> [sqlite3_soft_heap_limit64()] |
1538 | ** <li> [sqlite3_status()] |
1539 | ** </ul>)^ |
1540 | ** ^Memory allocation statistics are enabled by default unless SQLite is |
1541 | ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory |
1542 | ** allocation statistics are disabled by default. |
1543 | ** </dd> |
1544 | ** |
1545 | ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> |
1546 | ** <dd> ^This option specifies a static memory buffer that SQLite can use for |
1547 | ** scratch memory. There are three arguments: A pointer an 8-byte |
1548 | ** aligned memory buffer from which the scratch allocations will be |
1549 | ** drawn, the size of each scratch allocation (sz), |
1550 | ** and the maximum number of scratch allocations (N). The sz |
1551 | ** argument must be a multiple of 16. |
1552 | ** The first argument must be a pointer to an 8-byte aligned buffer |
1553 | ** of at least sz*N bytes of memory. |
1554 | ** ^SQLite will use no more than two scratch buffers per thread. So |
1555 | ** N should be set to twice the expected maximum number of threads. |
1556 | ** ^SQLite will never require a scratch buffer that is more than 6 |
1557 | ** times the database page size. ^If SQLite needs needs additional |
1558 | ** scratch memory beyond what is provided by this configuration option, then |
1559 | ** [sqlite3_malloc()] will be used to obtain the memory needed.</dd> |
1560 | ** |
1561 | ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> |
1562 | ** <dd> ^This option specifies a static memory buffer that SQLite can use for |
1563 | ** the database page cache with the default page cache implementation. |
1564 | ** This configuration should not be used if an application-define page |
1565 | ** cache implementation is loaded using the SQLITE_CONFIG_PCACHE2 option. |
1566 | ** There are three arguments to this option: A pointer to 8-byte aligned |
1567 | ** memory, the size of each page buffer (sz), and the number of pages (N). |
1568 | ** The sz argument should be the size of the largest database page |
1569 | ** (a power of two between 512 and 32768) plus a little extra for each |
1570 | ** page header. ^The page header size is 20 to 40 bytes depending on |
1571 | ** the host architecture. ^It is harmless, apart from the wasted memory, |
1572 | ** to make sz a little too large. The first |
1573 | ** argument should point to an allocation of at least sz*N bytes of memory. |
1574 | ** ^SQLite will use the memory provided by the first argument to satisfy its |
1575 | ** memory needs for the first N pages that it adds to cache. ^If additional |
1576 | ** page cache memory is needed beyond what is provided by this option, then |
1577 | ** SQLite goes to [sqlite3_malloc()] for the additional storage space. |
1578 | ** The pointer in the first argument must |
1579 | ** be aligned to an 8-byte boundary or subsequent behavior of SQLite |
1580 | ** will be undefined.</dd> |
1581 | ** |
1582 | ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> |
1583 | ** <dd> ^This option specifies a static memory buffer that SQLite will use |
1584 | ** for all of its dynamic memory allocation needs beyond those provided |
1585 | ** for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE]. |
1586 | ** There are three arguments: An 8-byte aligned pointer to the memory, |
1587 | ** the number of bytes in the memory buffer, and the minimum allocation size. |
1588 | ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts |
1589 | ** to using its default memory allocator (the system malloc() implementation), |
1590 | ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the |
1591 | ** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or |
1592 | ** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory |
1593 | ** allocator is engaged to handle all of SQLites memory allocation needs. |
1594 | ** The first pointer (the memory pointer) must be aligned to an 8-byte |
1595 | ** boundary or subsequent behavior of SQLite will be undefined. |
1596 | ** The minimum allocation size is capped at 2**12. Reasonable values |
1597 | ** for the minimum allocation size are 2**5 through 2**8.</dd> |
1598 | ** |
1599 | ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> |
1600 | ** <dd> ^(This option takes a single argument which is a pointer to an |
1601 | ** instance of the [sqlite3_mutex_methods] structure. The argument specifies |
1602 | ** alternative low-level mutex routines to be used in place |
1603 | ** the mutex routines built into SQLite.)^ ^SQLite makes a copy of the |
1604 | ** content of the [sqlite3_mutex_methods] structure before the call to |
1605 | ** [sqlite3_config()] returns. ^If SQLite is compiled with |
1606 | ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then |
1607 | ** the entire mutexing subsystem is omitted from the build and hence calls to |
1608 | ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will |
1609 | ** return [SQLITE_ERROR].</dd> |
1610 | ** |
1611 | ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> |
1612 | ** <dd> ^(This option takes a single argument which is a pointer to an |
1613 | ** instance of the [sqlite3_mutex_methods] structure. The |
1614 | ** [sqlite3_mutex_methods] |
1615 | ** structure is filled with the currently defined mutex routines.)^ |
1616 | ** This option can be used to overload the default mutex allocation |
1617 | ** routines with a wrapper used to track mutex usage for performance |
1618 | ** profiling or testing, for example. ^If SQLite is compiled with |
1619 | ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then |
1620 | ** the entire mutexing subsystem is omitted from the build and hence calls to |
1621 | ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will |
1622 | ** return [SQLITE_ERROR].</dd> |
1623 | ** |
1624 | ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> |
1625 | ** <dd> ^(This option takes two arguments that determine the default |
1626 | ** memory allocation for the lookaside memory allocator on each |
1627 | ** [database connection]. The first argument is the |
1628 | ** size of each lookaside buffer slot and the second is the number of |
1629 | ** slots allocated to each database connection.)^ ^(This option sets the |
1630 | ** <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] |
1631 | ** verb to [sqlite3_db_config()] can be used to change the lookaside |
1632 | ** configuration on individual connections.)^ </dd> |
1633 | ** |
1634 | ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> |
1635 | ** <dd> ^(This option takes a single argument which is a pointer to |
1636 | ** an [sqlite3_pcache_methods2] object. This object specifies the interface |
1637 | ** to a custom page cache implementation.)^ ^SQLite makes a copy of the |
1638 | ** object and uses it for page cache memory allocations.</dd> |
1639 | ** |
1640 | ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> |
1641 | ** <dd> ^(This option takes a single argument which is a pointer to an |
1642 | ** [sqlite3_pcache_methods2] object. SQLite copies of the current |
1643 | ** page cache implementation into that object.)^ </dd> |
1644 | ** |
1645 | ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> |
1646 | ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite |
1647 | ** global [error log]. |
1648 | ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a |
1649 | ** function with a call signature of void(*)(void*,int,const char*), |
1650 | ** and a pointer to void. ^If the function pointer is not NULL, it is |
1651 | ** invoked by [sqlite3_log()] to process each logging event. ^If the |
1652 | ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. |
1653 | ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is |
1654 | ** passed through as the first parameter to the application-defined logger |
1655 | ** function whenever that function is invoked. ^The second parameter to |
1656 | ** the logger function is a copy of the first parameter to the corresponding |
1657 | ** [sqlite3_log()] call and is intended to be a [result code] or an |
1658 | ** [extended result code]. ^The third parameter passed to the logger is |
1659 | ** log message after formatting via [sqlite3_snprintf()]. |
1660 | ** The SQLite logging interface is not reentrant; the logger function |
1661 | ** supplied by the application must not invoke any SQLite interface. |
1662 | ** In a multi-threaded application, the application-defined logger |
1663 | ** function must be threadsafe. </dd> |
1664 | ** |
1665 | ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI |
1666 | ** <dd>^(This option takes a single argument of type int. If non-zero, then |
1667 | ** URI handling is globally enabled. If the parameter is zero, then URI handling |
1668 | ** is globally disabled.)^ ^If URI handling is globally enabled, all filenames |
1669 | ** passed to [sqlite3_open()], [sqlite3_open_v2()], [sqlite3_open16()] or |
1670 | ** specified as part of [ATTACH] commands are interpreted as URIs, regardless |
1671 | ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database |
1672 | ** connection is opened. ^If it is globally disabled, filenames are |
1673 | ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the |
1674 | ** database connection is opened. ^(By default, URI handling is globally |
1675 | ** disabled. The default value may be changed by compiling with the |
1676 | ** [SQLITE_USE_URI] symbol defined.)^ |
1677 | ** |
1678 | ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN |
1679 | ** <dd>^This option takes a single integer argument which is interpreted as |
1680 | ** a boolean in order to enable or disable the use of covering indices for |
1681 | ** full table scans in the query optimizer. ^The default setting is determined |
1682 | ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" |
1683 | ** if that compile-time option is omitted. |
1684 | ** The ability to disable the use of covering indices for full table scans |
1685 | ** is because some incorrectly coded legacy applications might malfunction |
1686 | ** when the optimization is enabled. Providing the ability to |
1687 | ** disable the optimization allows the older, buggy application code to work |
1688 | ** without change even with newer versions of SQLite. |
1689 | ** |
1690 | ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] |
1691 | ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE |
1692 | ** <dd> These options are obsolete and should not be used by new code. |
1693 | ** They are retained for backwards compatibility but are now no-ops. |
1694 | ** </dd> |
1695 | ** |
1696 | ** [[SQLITE_CONFIG_SQLLOG]] |
1697 | ** <dt>SQLITE_CONFIG_SQLLOG |
1698 | ** <dd>This option is only available if sqlite is compiled with the |
1699 | ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should |
1700 | ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). |
1701 | ** The second should be of type (void*). The callback is invoked by the library |
1702 | ** in three separate circumstances, identified by the value passed as the |
1703 | ** fourth parameter. If the fourth parameter is 0, then the database connection |
1704 | ** passed as the second argument has just been opened. The third argument |
1705 | ** points to a buffer containing the name of the main database file. If the |
1706 | ** fourth parameter is 1, then the SQL statement that the third parameter |
1707 | ** points to has just been executed. Or, if the fourth parameter is 2, then |
1708 | ** the connection being passed as the second parameter is being closed. The |
1709 | ** third parameter is passed NULL In this case. An example of using this |
1710 | ** configuration option can be seen in the "test_sqllog.c" source file in |
1711 | ** the canonical SQLite source tree.</dd> |
1712 | ** |
1713 | ** [[SQLITE_CONFIG_MMAP_SIZE]] |
1714 | ** <dt>SQLITE_CONFIG_MMAP_SIZE |
1715 | ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values |
1716 | ** that are the default mmap size limit (the default setting for |
1717 | ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. |
1718 | ** ^The default setting can be overridden by each database connection using |
1719 | ** either the [PRAGMA mmap_size] command, or by using the |
1720 | ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size |
1721 | ** cannot be changed at run-time. Nor may the maximum allowed mmap size |
1722 | ** exceed the compile-time maximum mmap size set by the |
1723 | ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ |
1724 | ** ^If either argument to this option is negative, then that argument is |
1725 | ** changed to its compile-time default. |
1726 | ** |
1727 | ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] |
1728 | ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE |
1729 | ** <dd>^This option is only available if SQLite is compiled for Windows |
1730 | ** with the [SQLITE_WIN32_MALLOC] pre-processor macro defined. |
1731 | ** SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value |
1732 | ** that specifies the maximum size of the created heap. |
1733 | ** </dl> |
1734 | */ |
1735 | #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ |
1736 | #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ |
1737 | #define SQLITE_CONFIG_SERIALIZED 3 /* nil */ |
1738 | #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ |
1739 | #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ |
1740 | #define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ |
1741 | #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ |
1742 | #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ |
1743 | #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ |
1744 | #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ |
1745 | #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ |
1746 | /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ |
1747 | #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ |
1748 | #define SQLITE_CONFIG_PCACHE 14 /* no-op */ |
1749 | #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ |
1750 | #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ |
1751 | #define SQLITE_CONFIG_URI 17 /* int */ |
1752 | #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ |
1753 | #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ |
1754 | #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ |
1755 | #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ |
1756 | #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ |
1757 | #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ |
1758 | |
1759 | /* |
1760 | ** CAPI3REF: Database Connection Configuration Options |
1761 | ** |
1762 | ** These constants are the available integer configuration options that |
1763 | ** can be passed as the second argument to the [sqlite3_db_config()] interface. |
1764 | ** |
1765 | ** New configuration options may be added in future releases of SQLite. |
1766 | ** Existing configuration options might be discontinued. Applications |
1767 | ** should check the return code from [sqlite3_db_config()] to make sure that |
1768 | ** the call worked. ^The [sqlite3_db_config()] interface will return a |
1769 | ** non-zero [error code] if a discontinued or unsupported configuration option |
1770 | ** is invoked. |
1771 | ** |
1772 | ** <dl> |
1773 | ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> |
1774 | ** <dd> ^This option takes three additional arguments that determine the |
1775 | ** [lookaside memory allocator] configuration for the [database connection]. |
1776 | ** ^The first argument (the third parameter to [sqlite3_db_config()] is a |
1777 | ** pointer to a memory buffer to use for lookaside memory. |
1778 | ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb |
1779 | ** may be NULL in which case SQLite will allocate the |
1780 | ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the |
1781 | ** size of each lookaside buffer slot. ^The third argument is the number of |
1782 | ** slots. The size of the buffer in the first argument must be greater than |
1783 | ** or equal to the product of the second and third arguments. The buffer |
1784 | ** must be aligned to an 8-byte boundary. ^If the second argument to |
1785 | ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally |
1786 | ** rounded down to the next smaller multiple of 8. ^(The lookaside memory |
1787 | ** configuration for a database connection can only be changed when that |
1788 | ** connection is not currently using lookaside memory, or in other words |
1789 | ** when the "current value" returned by |
1790 | ** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. |
1791 | ** Any attempt to change the lookaside memory configuration when lookaside |
1792 | ** memory is in use leaves the configuration unchanged and returns |
1793 | ** [SQLITE_BUSY].)^</dd> |
1794 | ** |
1795 | ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> |
1796 | ** <dd> ^This option is used to enable or disable the enforcement of |
1797 | ** [foreign key constraints]. There should be two additional arguments. |
1798 | ** The first argument is an integer which is 0 to disable FK enforcement, |
1799 | ** positive to enable FK enforcement or negative to leave FK enforcement |
1800 | ** unchanged. The second parameter is a pointer to an integer into which |
1801 | ** is written 0 or 1 to indicate whether FK enforcement is off or on |
1802 | ** following this call. The second parameter may be a NULL pointer, in |
1803 | ** which case the FK enforcement setting is not reported back. </dd> |
1804 | ** |
1805 | ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> |
1806 | ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. |
1807 | ** There should be two additional arguments. |
1808 | ** The first argument is an integer which is 0 to disable triggers, |
1809 | ** positive to enable triggers or negative to leave the setting unchanged. |
1810 | ** The second parameter is a pointer to an integer into which |
1811 | ** is written 0 or 1 to indicate whether triggers are disabled or enabled |
1812 | ** following this call. The second parameter may be a NULL pointer, in |
1813 | ** which case the trigger setting is not reported back. </dd> |
1814 | ** |
1815 | ** </dl> |
1816 | */ |
1817 | #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ |
1818 | #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ |
1819 | #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ |
1820 | |
1821 | |
1822 | /* |
1823 | ** CAPI3REF: Enable Or Disable Extended Result Codes |
1824 | ** |
1825 | ** ^The sqlite3_extended_result_codes() routine enables or disables the |
1826 | ** [extended result codes] feature of SQLite. ^The extended result |
1827 | ** codes are disabled by default for historical compatibility. |
1828 | */ |
1829 | SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff); |
1830 | |
1831 | /* |
1832 | ** CAPI3REF: Last Insert Rowid |
1833 | ** |
1834 | ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) |
1835 | ** has a unique 64-bit signed |
1836 | ** integer key called the [ROWID | "rowid"]. ^The rowid is always available |
1837 | ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those |
1838 | ** names are not also used by explicitly declared columns. ^If |
1839 | ** the table has a column of type [INTEGER PRIMARY KEY] then that column |
1840 | ** is another alias for the rowid. |
1841 | ** |
1842 | ** ^The sqlite3_last_insert_rowid(D) interface returns the [rowid] of the |
1843 | ** most recent successful [INSERT] into a rowid table or [virtual table] |
1844 | ** on database connection D. |
1845 | ** ^Inserts into [WITHOUT ROWID] tables are not recorded. |
1846 | ** ^If no successful [INSERT]s into rowid tables |
1847 | ** have ever occurred on the database connection D, |
1848 | ** then sqlite3_last_insert_rowid(D) returns zero. |
1849 | ** |
1850 | ** ^(If an [INSERT] occurs within a trigger or within a [virtual table] |
1851 | ** method, then this routine will return the [rowid] of the inserted |
1852 | ** row as long as the trigger or virtual table method is running. |
1853 | ** But once the trigger or virtual table method ends, the value returned |
1854 | ** by this routine reverts to what it was before the trigger or virtual |
1855 | ** table method began.)^ |
1856 | ** |
1857 | ** ^An [INSERT] that fails due to a constraint violation is not a |
1858 | ** successful [INSERT] and does not change the value returned by this |
1859 | ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, |
1860 | ** and INSERT OR ABORT make no changes to the return value of this |
1861 | ** routine when their insertion fails. ^(When INSERT OR REPLACE |
1862 | ** encounters a constraint violation, it does not fail. The |
1863 | ** INSERT continues to completion after deleting rows that caused |
1864 | ** the constraint problem so INSERT OR REPLACE will always change |
1865 | ** the return value of this interface.)^ |
1866 | ** |
1867 | ** ^For the purposes of this routine, an [INSERT] is considered to |
1868 | ** be successful even if it is subsequently rolled back. |
1869 | ** |
1870 | ** This function is accessible to SQL statements via the |
1871 | ** [last_insert_rowid() SQL function]. |
1872 | ** |
1873 | ** If a separate thread performs a new [INSERT] on the same |
1874 | ** database connection while the [sqlite3_last_insert_rowid()] |
1875 | ** function is running and thus changes the last insert [rowid], |
1876 | ** then the value returned by [sqlite3_last_insert_rowid()] is |
1877 | ** unpredictable and might not equal either the old or the new |
1878 | ** last insert [rowid]. |
1879 | */ |
1880 | SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); |
1881 | |
1882 | /* |
1883 | ** CAPI3REF: Count The Number Of Rows Modified |
1884 | ** |
1885 | ** ^This function returns the number of database rows that were changed |
1886 | ** or inserted or deleted by the most recently completed SQL statement |
1887 | ** on the [database connection] specified by the first parameter. |
1888 | ** ^(Only changes that are directly specified by the [INSERT], [UPDATE], |
1889 | ** or [DELETE] statement are counted. Auxiliary changes caused by |
1890 | ** triggers or [foreign key actions] are not counted.)^ Use the |
1891 | ** [sqlite3_total_changes()] function to find the total number of changes |
1892 | ** including changes caused by triggers and foreign key actions. |
1893 | ** |
1894 | ** ^Changes to a view that are simulated by an [INSTEAD OF trigger] |
1895 | ** are not counted. Only real table changes are counted. |
1896 | ** |
1897 | ** ^(A "row change" is a change to a single row of a single table |
1898 | ** caused by an INSERT, DELETE, or UPDATE statement. Rows that |
1899 | ** are changed as side effects of [REPLACE] constraint resolution, |
1900 | ** rollback, ABORT processing, [DROP TABLE], or by any other |
1901 | ** mechanisms do not count as direct row changes.)^ |
1902 | ** |
1903 | ** A "trigger context" is a scope of execution that begins and |
1904 | ** ends with the script of a [CREATE TRIGGER | trigger]. |
1905 | ** Most SQL statements are |
1906 | ** evaluated outside of any trigger. This is the "top level" |
1907 | ** trigger context. If a trigger fires from the top level, a |
1908 | ** new trigger context is entered for the duration of that one |
1909 | ** trigger. Subtriggers create subcontexts for their duration. |
1910 | ** |
1911 | ** ^Calling [sqlite3_exec()] or [sqlite3_step()] recursively does |
1912 | ** not create a new trigger context. |
1913 | ** |
1914 | ** ^This function returns the number of direct row changes in the |
1915 | ** most recent INSERT, UPDATE, or DELETE statement within the same |
1916 | ** trigger context. |
1917 | ** |
1918 | ** ^Thus, when called from the top level, this function returns the |
1919 | ** number of changes in the most recent INSERT, UPDATE, or DELETE |
1920 | ** that also occurred at the top level. ^(Within the body of a trigger, |
1921 | ** the sqlite3_changes() interface can be called to find the number of |
1922 | ** changes in the most recently completed INSERT, UPDATE, or DELETE |
1923 | ** statement within the body of the same trigger. |
1924 | ** However, the number returned does not include changes |
1925 | ** caused by subtriggers since those have their own context.)^ |
1926 | ** |
1927 | ** See also the [sqlite3_total_changes()] interface, the |
1928 | ** [count_changes pragma], and the [changes() SQL function]. |
1929 | ** |
1930 | ** If a separate thread makes changes on the same database connection |
1931 | ** while [sqlite3_changes()] is running then the value returned |
1932 | ** is unpredictable and not meaningful. |
1933 | */ |
1934 | SQLITE_API int sqlite3_changes(sqlite3*); |
1935 | |
1936 | /* |
1937 | ** CAPI3REF: Total Number Of Rows Modified |
1938 | ** |
1939 | ** ^This function returns the number of row changes caused by [INSERT], |
1940 | ** [UPDATE] or [DELETE] statements since the [database connection] was opened. |
1941 | ** ^(The count returned by sqlite3_total_changes() includes all changes |
1942 | ** from all [CREATE TRIGGER | trigger] contexts and changes made by |
1943 | ** [foreign key actions]. However, |
1944 | ** the count does not include changes used to implement [REPLACE] constraints, |
1945 | ** do rollbacks or ABORT processing, or [DROP TABLE] processing. The |
1946 | ** count does not include rows of views that fire an [INSTEAD OF trigger], |
1947 | ** though if the INSTEAD OF trigger makes changes of its own, those changes |
1948 | ** are counted.)^ |
1949 | ** ^The sqlite3_total_changes() function counts the changes as soon as |
1950 | ** the statement that makes them is completed (when the statement handle |
1951 | ** is passed to [sqlite3_reset()] or [sqlite3_finalize()]). |
1952 | ** |
1953 | ** See also the [sqlite3_changes()] interface, the |
1954 | ** [count_changes pragma], and the [total_changes() SQL function]. |
1955 | ** |
1956 | ** If a separate thread makes changes on the same database connection |
1957 | ** while [sqlite3_total_changes()] is running then the value |
1958 | ** returned is unpredictable and not meaningful. |
1959 | */ |
1960 | SQLITE_API int sqlite3_total_changes(sqlite3*); |
1961 | |
1962 | /* |
1963 | ** CAPI3REF: Interrupt A Long-Running Query |
1964 | ** |
1965 | ** ^This function causes any pending database operation to abort and |
1966 | ** return at its earliest opportunity. This routine is typically |
1967 | ** called in response to a user action such as pressing "Cancel" |
1968 | ** or Ctrl-C where the user wants a long query operation to halt |
1969 | ** immediately. |
1970 | ** |
1971 | ** ^It is safe to call this routine from a thread different from the |
1972 | ** thread that is currently running the database operation. But it |
1973 | ** is not safe to call this routine with a [database connection] that |
1974 | ** is closed or might close before sqlite3_interrupt() returns. |
1975 | ** |
1976 | ** ^If an SQL operation is very nearly finished at the time when |
1977 | ** sqlite3_interrupt() is called, then it might not have an opportunity |
1978 | ** to be interrupted and might continue to completion. |
1979 | ** |
1980 | ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. |
1981 | ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE |
1982 | ** that is inside an explicit transaction, then the entire transaction |
1983 | ** will be rolled back automatically. |
1984 | ** |
1985 | ** ^The sqlite3_interrupt(D) call is in effect until all currently running |
1986 | ** SQL statements on [database connection] D complete. ^Any new SQL statements |
1987 | ** that are started after the sqlite3_interrupt() call and before the |
1988 | ** running statements reaches zero are interrupted as if they had been |
1989 | ** running prior to the sqlite3_interrupt() call. ^New SQL statements |
1990 | ** that are started after the running statement count reaches zero are |
1991 | ** not effected by the sqlite3_interrupt(). |
1992 | ** ^A call to sqlite3_interrupt(D) that occurs when there are no running |
1993 | ** SQL statements is a no-op and has no effect on SQL statements |
1994 | ** that are started after the sqlite3_interrupt() call returns. |
1995 | ** |
1996 | ** If the database connection closes while [sqlite3_interrupt()] |
1997 | ** is running then bad things will likely happen. |
1998 | */ |
1999 | SQLITE_API void sqlite3_interrupt(sqlite3*); |
2000 | |
2001 | /* |
2002 | ** CAPI3REF: Determine If An SQL Statement Is Complete |
2003 | ** |
2004 | ** These routines are useful during command-line input to determine if the |
2005 | ** currently entered text seems to form a complete SQL statement or |
2006 | ** if additional input is needed before sending the text into |
2007 | ** SQLite for parsing. ^These routines return 1 if the input string |
2008 | ** appears to be a complete SQL statement. ^A statement is judged to be |
2009 | ** complete if it ends with a semicolon token and is not a prefix of a |
2010 | ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within |
2011 | ** string literals or quoted identifier names or comments are not |
2012 | ** independent tokens (they are part of the token in which they are |
2013 | ** embedded) and thus do not count as a statement terminator. ^Whitespace |
2014 | ** and comments that follow the final semicolon are ignored. |
2015 | ** |
2016 | ** ^These routines return 0 if the statement is incomplete. ^If a |
2017 | ** memory allocation fails, then SQLITE_NOMEM is returned. |
2018 | ** |
2019 | ** ^These routines do not parse the SQL statements thus |
2020 | ** will not detect syntactically incorrect SQL. |
2021 | ** |
2022 | ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior |
2023 | ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked |
2024 | ** automatically by sqlite3_complete16(). If that initialization fails, |
2025 | ** then the return value from sqlite3_complete16() will be non-zero |
2026 | ** regardless of whether or not the input SQL is complete.)^ |
2027 | ** |
2028 | ** The input to [sqlite3_complete()] must be a zero-terminated |
2029 | ** UTF-8 string. |
2030 | ** |
2031 | ** The input to [sqlite3_complete16()] must be a zero-terminated |
2032 | ** UTF-16 string in native byte order. |
2033 | */ |
2034 | SQLITE_API int sqlite3_complete(const char *sql); |
2035 | SQLITE_API int sqlite3_complete16(const void *sql); |
2036 | |
2037 | /* |
2038 | ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors |
2039 | ** |
2040 | ** ^This routine sets a callback function that might be invoked whenever |
2041 | ** an attempt is made to open a database table that another thread |
2042 | ** or process has locked. |
2043 | ** |
2044 | ** ^If the busy callback is NULL, then [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] |
2045 | ** is returned immediately upon encountering the lock. ^If the busy callback |
2046 | ** is not NULL, then the callback might be invoked with two arguments. |
2047 | ** |
2048 | ** ^The first argument to the busy handler is a copy of the void* pointer which |
2049 | ** is the third argument to sqlite3_busy_handler(). ^The second argument to |
2050 | ** the busy handler callback is the number of times that the busy handler has |
2051 | ** been invoked for this locking event. ^If the |
2052 | ** busy callback returns 0, then no additional attempts are made to |
2053 | ** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned. |
2054 | ** ^If the callback returns non-zero, then another attempt |
2055 | ** is made to open the database for reading and the cycle repeats. |
2056 | ** |
2057 | ** The presence of a busy handler does not guarantee that it will be invoked |
2058 | ** when there is lock contention. ^If SQLite determines that invoking the busy |
2059 | ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] |
2060 | ** or [SQLITE_IOERR_BLOCKED] instead of invoking the busy handler. |
2061 | ** Consider a scenario where one process is holding a read lock that |
2062 | ** it is trying to promote to a reserved lock and |
2063 | ** a second process is holding a reserved lock that it is trying |
2064 | ** to promote to an exclusive lock. The first process cannot proceed |
2065 | ** because it is blocked by the second and the second process cannot |
2066 | ** proceed because it is blocked by the first. If both processes |
2067 | ** invoke the busy handlers, neither will make any progress. Therefore, |
2068 | ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this |
2069 | ** will induce the first process to release its read lock and allow |
2070 | ** the second process to proceed. |
2071 | ** |
2072 | ** ^The default busy callback is NULL. |
2073 | ** |
2074 | ** ^The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED] |
2075 | ** when SQLite is in the middle of a large transaction where all the |
2076 | ** changes will not fit into the in-memory cache. SQLite will |
2077 | ** already hold a RESERVED lock on the database file, but it needs |
2078 | ** to promote this lock to EXCLUSIVE so that it can spill cache |
2079 | ** pages into the database file without harm to concurrent |
2080 | ** readers. ^If it is unable to promote the lock, then the in-memory |
2081 | ** cache will be left in an inconsistent state and so the error |
2082 | ** code is promoted from the relatively benign [SQLITE_BUSY] to |
2083 | ** the more severe [SQLITE_IOERR_BLOCKED]. ^This error code promotion |
2084 | ** forces an automatic rollback of the changes. See the |
2085 | ** <a href="/cvstrac/wiki?p=CorruptionFollowingBusyError"> |
2086 | ** CorruptionFollowingBusyError</a> wiki page for a discussion of why |
2087 | ** this is important. |
2088 | ** |
2089 | ** ^(There can only be a single busy handler defined for each |
2090 | ** [database connection]. Setting a new busy handler clears any |
2091 | ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] |
2092 | ** will also set or clear the busy handler. |
2093 | ** |
2094 | ** The busy callback should not take any actions which modify the |
2095 | ** database connection that invoked the busy handler. Any such actions |
2096 | ** result in undefined behavior. |
2097 | ** |
2098 | ** A busy handler must not close the database connection |
2099 | ** or [prepared statement] that invoked the busy handler. |
2100 | */ |
2101 | SQLITE_API int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*); |
2102 | |
2103 | /* |
2104 | ** CAPI3REF: Set A Busy Timeout |
2105 | ** |
2106 | ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps |
2107 | ** for a specified amount of time when a table is locked. ^The handler |
2108 | ** will sleep multiple times until at least "ms" milliseconds of sleeping |
2109 | ** have accumulated. ^After at least "ms" milliseconds of sleeping, |
2110 | ** the handler returns 0 which causes [sqlite3_step()] to return |
2111 | ** [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]. |
2112 | ** |
2113 | ** ^Calling this routine with an argument less than or equal to zero |
2114 | ** turns off all busy handlers. |
2115 | ** |
2116 | ** ^(There can only be a single busy handler for a particular |
2117 | ** [database connection] any any given moment. If another busy handler |
2118 | ** was defined (using [sqlite3_busy_handler()]) prior to calling |
2119 | ** this routine, that other busy handler is cleared.)^ |
2120 | */ |
2121 | SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms); |
2122 | |
2123 | /* |
2124 | ** CAPI3REF: Convenience Routines For Running Queries |
2125 | ** |
2126 | ** This is a legacy interface that is preserved for backwards compatibility. |
2127 | ** Use of this interface is not recommended. |
2128 | ** |
2129 | ** Definition: A <b>result table</b> is memory data structure created by the |
2130 | ** [sqlite3_get_table()] interface. A result table records the |
2131 | ** complete query results from one or more queries. |
2132 | ** |
2133 | ** The table conceptually has a number of rows and columns. But |
2134 | ** these numbers are not part of the result table itself. These |
2135 | ** numbers are obtained separately. Let N be the number of rows |
2136 | ** and M be the number of columns. |
2137 | ** |
2138 | ** A result table is an array of pointers to zero-terminated UTF-8 strings. |
2139 | ** There are (N+1)*M elements in the array. The first M pointers point |
2140 | ** to zero-terminated strings that contain the names of the columns. |
2141 | ** The remaining entries all point to query results. NULL values result |
2142 | ** in NULL pointers. All other values are in their UTF-8 zero-terminated |
2143 | ** string representation as returned by [sqlite3_column_text()]. |
2144 | ** |
2145 | ** A result table might consist of one or more memory allocations. |
2146 | ** It is not safe to pass a result table directly to [sqlite3_free()]. |
2147 | ** A result table should be deallocated using [sqlite3_free_table()]. |
2148 | ** |
2149 | ** ^(As an example of the result table format, suppose a query result |
2150 | ** is as follows: |
2151 | ** |
2152 | ** <blockquote><pre> |
2153 | ** Name | Age |
2154 | ** ----------------------- |
2155 | ** Alice | 43 |
2156 | ** Bob | 28 |
2157 | ** Cindy | 21 |
2158 | ** </pre></blockquote> |
2159 | ** |
2160 | ** There are two column (M==2) and three rows (N==3). Thus the |
2161 | ** result table has 8 entries. Suppose the result table is stored |
2162 | ** in an array names azResult. Then azResult holds this content: |
2163 | ** |
2164 | ** <blockquote><pre> |
2165 | ** azResult[0] = "Name"; |
2166 | ** azResult[1] = "Age"; |
2167 | ** azResult[2] = "Alice"; |
2168 | ** azResult[3] = "43"; |
2169 | ** azResult[4] = "Bob"; |
2170 | ** azResult[5] = "28"; |
2171 | ** azResult[6] = "Cindy"; |
2172 | ** azResult[7] = "21"; |
2173 | ** </pre></blockquote>)^ |
2174 | ** |
2175 | ** ^The sqlite3_get_table() function evaluates one or more |
2176 | ** semicolon-separated SQL statements in the zero-terminated UTF-8 |
2177 | ** string of its 2nd parameter and returns a result table to the |
2178 | ** pointer given in its 3rd parameter. |
2179 | ** |
2180 | ** After the application has finished with the result from sqlite3_get_table(), |
2181 | ** it must pass the result table pointer to sqlite3_free_table() in order to |
2182 | ** release the memory that was malloced. Because of the way the |
2183 | ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling |
2184 | ** function must not try to call [sqlite3_free()] directly. Only |
2185 | ** [sqlite3_free_table()] is able to release the memory properly and safely. |
2186 | ** |
2187 | ** The sqlite3_get_table() interface is implemented as a wrapper around |
2188 | ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access |
2189 | ** to any internal data structures of SQLite. It uses only the public |
2190 | ** interface defined here. As a consequence, errors that occur in the |
2191 | ** wrapper layer outside of the internal [sqlite3_exec()] call are not |
2192 | ** reflected in subsequent calls to [sqlite3_errcode()] or |
2193 | ** [sqlite3_errmsg()]. |
2194 | */ |
2195 | SQLITE_API int sqlite3_get_table( |
2196 | sqlite3 *db, /* An open database */ |
2197 | const char *zSql, /* SQL to be evaluated */ |
2198 | char ***pazResult, /* Results of the query */ |
2199 | int *pnRow, /* Number of result rows written here */ |
2200 | int *pnColumn, /* Number of result columns written here */ |
2201 | char **pzErrmsg /* Error msg written here */ |
2202 | ); |
2203 | SQLITE_API void sqlite3_free_table(char **result); |
2204 | |
2205 | /* |
2206 | ** CAPI3REF: Formatted String Printing Functions |
2207 | ** |
2208 | ** These routines are work-alikes of the "printf()" family of functions |
2209 | ** from the standard C library. |
2210 | ** |
2211 | ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their |
2212 | ** results into memory obtained from [sqlite3_malloc()]. |
2213 | ** The strings returned by these two routines should be |
2214 | ** released by [sqlite3_free()]. ^Both routines return a |
2215 | ** NULL pointer if [sqlite3_malloc()] is unable to allocate enough |
2216 | ** memory to hold the resulting string. |
2217 | ** |
2218 | ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from |
2219 | ** the standard C library. The result is written into the |
2220 | ** buffer supplied as the second parameter whose size is given by |
2221 | ** the first parameter. Note that the order of the |
2222 | ** first two parameters is reversed from snprintf().)^ This is an |
2223 | ** historical accident that cannot be fixed without breaking |
2224 | ** backwards compatibility. ^(Note also that sqlite3_snprintf() |
2225 | ** returns a pointer to its buffer instead of the number of |
2226 | ** characters actually written into the buffer.)^ We admit that |
2227 | ** the number of characters written would be a more useful return |
2228 | ** value but we cannot change the implementation of sqlite3_snprintf() |
2229 | ** now without breaking compatibility. |
2230 | ** |
2231 | ** ^As long as the buffer size is greater than zero, sqlite3_snprintf() |
2232 | ** guarantees that the buffer is always zero-terminated. ^The first |
2233 | ** parameter "n" is the total size of the buffer, including space for |
2234 | ** the zero terminator. So the longest string that can be completely |
2235 | ** written will be n-1 characters. |
2236 | ** |
2237 | ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). |
2238 | ** |
2239 | ** These routines all implement some additional formatting |
2240 | ** options that are useful for constructing SQL statements. |
2241 | ** All of the usual printf() formatting options apply. In addition, there |
2242 | ** is are "%q", "%Q", and "%z" options. |
2243 | ** |
2244 | ** ^(The %q option works like %s in that it substitutes a nul-terminated |
2245 | ** string from the argument list. But %q also doubles every '\'' character. |
2246 | ** %q is designed for use inside a string literal.)^ By doubling each '\'' |
2247 | ** character it escapes that character and allows it to be inserted into |
2248 | ** the string. |
2249 | ** |
2250 | ** For example, assume the string variable zText contains text as follows: |
2251 | ** |
2252 | ** <blockquote><pre> |
2253 | ** char *zText = "It's a happy day!"; |
2254 | ** </pre></blockquote> |
2255 | ** |
2256 | ** One can use this text in an SQL statement as follows: |
2257 | ** |
2258 | ** <blockquote><pre> |
2259 | ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); |
2260 | ** sqlite3_exec(db, zSQL, 0, 0, 0); |
2261 | ** sqlite3_free(zSQL); |
2262 | ** </pre></blockquote> |
2263 | ** |
2264 | ** Because the %q format string is used, the '\'' character in zText |
2265 | ** is escaped and the SQL generated is as follows: |
2266 | ** |
2267 | ** <blockquote><pre> |
2268 | ** INSERT INTO table1 VALUES('It''s a happy day!') |
2269 | ** </pre></blockquote> |
2270 | ** |
2271 | ** This is correct. Had we used %s instead of %q, the generated SQL |
2272 | ** would have looked like this: |
2273 | ** |
2274 | ** <blockquote><pre> |
2275 | ** INSERT INTO table1 VALUES('It's a happy day!'); |
2276 | ** </pre></blockquote> |
2277 | ** |
2278 | ** This second example is an SQL syntax error. As a general rule you should |
2279 | ** always use %q instead of %s when inserting text into a string literal. |
2280 | ** |
2281 | ** ^(The %Q option works like %q except it also adds single quotes around |
2282 | ** the outside of the total string. Additionally, if the parameter in the |
2283 | ** argument list is a NULL pointer, %Q substitutes the text "NULL" (without |
2284 | ** single quotes).)^ So, for example, one could say: |
2285 | ** |
2286 | ** <blockquote><pre> |
2287 | ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); |
2288 | ** sqlite3_exec(db, zSQL, 0, 0, 0); |
2289 | ** sqlite3_free(zSQL); |
2290 | ** </pre></blockquote> |
2291 | ** |
2292 | ** The code above will render a correct SQL statement in the zSQL |
2293 | ** variable even if the zText variable is a NULL pointer. |
2294 | ** |
2295 | ** ^(The "%z" formatting option works like "%s" but with the |
2296 | ** addition that after the string has been read and copied into |
2297 | ** the result, [sqlite3_free()] is called on the input string.)^ |
2298 | */ |
2299 | SQLITE_API char *sqlite3_mprintf(const char*,...); |
2300 | SQLITE_API char *sqlite3_vmprintf(const char*, va_list); |
2301 | SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...); |
2302 | SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list); |
2303 | |
2304 | /* |
2305 | ** CAPI3REF: Memory Allocation Subsystem |
2306 | ** |
2307 | ** The SQLite core uses these three routines for all of its own |
2308 | ** internal memory allocation needs. "Core" in the previous sentence |
2309 | ** does not include operating-system specific VFS implementation. The |
2310 | ** Windows VFS uses native malloc() and free() for some operations. |
2311 | ** |
2312 | ** ^The sqlite3_malloc() routine returns a pointer to a block |
2313 | ** of memory at least N bytes in length, where N is the parameter. |
2314 | ** ^If sqlite3_malloc() is unable to obtain sufficient free |
2315 | ** memory, it returns a NULL pointer. ^If the parameter N to |
2316 | ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns |
2317 | ** a NULL pointer. |
2318 | ** |
2319 | ** ^Calling sqlite3_free() with a pointer previously returned |
2320 | ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so |
2321 | ** that it might be reused. ^The sqlite3_free() routine is |
2322 | ** a no-op if is called with a NULL pointer. Passing a NULL pointer |
2323 | ** to sqlite3_free() is harmless. After being freed, memory |
2324 | ** should neither be read nor written. Even reading previously freed |
2325 | ** memory might result in a segmentation fault or other severe error. |
2326 | ** Memory corruption, a segmentation fault, or other severe error |
2327 | ** might result if sqlite3_free() is called with a non-NULL pointer that |
2328 | ** was not obtained from sqlite3_malloc() or sqlite3_realloc(). |
2329 | ** |
2330 | ** ^(The sqlite3_realloc() interface attempts to resize a |
2331 | ** prior memory allocation to be at least N bytes, where N is the |
2332 | ** second parameter. The memory allocation to be resized is the first |
2333 | ** parameter.)^ ^ If the first parameter to sqlite3_realloc() |
2334 | ** is a NULL pointer then its behavior is identical to calling |
2335 | ** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc(). |
2336 | ** ^If the second parameter to sqlite3_realloc() is zero or |
2337 | ** negative then the behavior is exactly the same as calling |
2338 | ** sqlite3_free(P) where P is the first parameter to sqlite3_realloc(). |
2339 | ** ^sqlite3_realloc() returns a pointer to a memory allocation |
2340 | ** of at least N bytes in size or NULL if sufficient memory is unavailable. |
2341 | ** ^If M is the size of the prior allocation, then min(N,M) bytes |
2342 | ** of the prior allocation are copied into the beginning of buffer returned |
2343 | ** by sqlite3_realloc() and the prior allocation is freed. |
2344 | ** ^If sqlite3_realloc() returns NULL, then the prior allocation |
2345 | ** is not freed. |
2346 | ** |
2347 | ** ^The memory returned by sqlite3_malloc() and sqlite3_realloc() |
2348 | ** is always aligned to at least an 8 byte boundary, or to a |
2349 | ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time |
2350 | ** option is used. |
2351 | ** |
2352 | ** In SQLite version 3.5.0 and 3.5.1, it was possible to define |
2353 | ** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in |
2354 | ** implementation of these routines to be omitted. That capability |
2355 | ** is no longer provided. Only built-in memory allocators can be used. |
2356 | ** |
2357 | ** Prior to SQLite version 3.7.10, the Windows OS interface layer called |
2358 | ** the system malloc() and free() directly when converting |
2359 | ** filenames between the UTF-8 encoding used by SQLite |
2360 | ** and whatever filename encoding is used by the particular Windows |
2361 | ** installation. Memory allocation errors were detected, but |
2362 | ** they were reported back as [SQLITE_CANTOPEN] or |
2363 | ** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. |
2364 | ** |
2365 | ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] |
2366 | ** must be either NULL or else pointers obtained from a prior |
2367 | ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have |
2368 | ** not yet been released. |
2369 | ** |
2370 | ** The application must not read or write any part of |
2371 | ** a block of memory after it has been released using |
2372 | ** [sqlite3_free()] or [sqlite3_realloc()]. |
2373 | */ |
2374 | SQLITE_API void *sqlite3_malloc(int); |
2375 | SQLITE_API void *sqlite3_realloc(void*, int); |
2376 | SQLITE_API void sqlite3_free(void*); |
2377 | |
2378 | /* |
2379 | ** CAPI3REF: Memory Allocator Statistics |
2380 | ** |
2381 | ** SQLite provides these two interfaces for reporting on the status |
2382 | ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] |
2383 | ** routines, which form the built-in memory allocation subsystem. |
2384 | ** |
2385 | ** ^The [sqlite3_memory_used()] routine returns the number of bytes |
2386 | ** of memory currently outstanding (malloced but not freed). |
2387 | ** ^The [sqlite3_memory_highwater()] routine returns the maximum |
2388 | ** value of [sqlite3_memory_used()] since the high-water mark |
2389 | ** was last reset. ^The values returned by [sqlite3_memory_used()] and |
2390 | ** [sqlite3_memory_highwater()] include any overhead |
2391 | ** added by SQLite in its implementation of [sqlite3_malloc()], |
2392 | ** but not overhead added by the any underlying system library |
2393 | ** routines that [sqlite3_malloc()] may call. |
2394 | ** |
2395 | ** ^The memory high-water mark is reset to the current value of |
2396 | ** [sqlite3_memory_used()] if and only if the parameter to |
2397 | ** [sqlite3_memory_highwater()] is true. ^The value returned |
2398 | ** by [sqlite3_memory_highwater(1)] is the high-water mark |
2399 | ** prior to the reset. |
2400 | */ |
2401 | SQLITE_API sqlite3_int64 sqlite3_memory_used(void); |
2402 | SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag); |
2403 | |
2404 | /* |
2405 | ** CAPI3REF: Pseudo-Random Number Generator |
2406 | ** |
2407 | ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to |
2408 | ** select random [ROWID | ROWIDs] when inserting new records into a table that |
2409 | ** already uses the largest possible [ROWID]. The PRNG is also used for |
2410 | ** the build-in random() and randomblob() SQL functions. This interface allows |
2411 | ** applications to access the same PRNG for other purposes. |
2412 | ** |
2413 | ** ^A call to this routine stores N bytes of randomness into buffer P. |
2414 | ** ^If N is less than one, then P can be a NULL pointer. |
2415 | ** |
2416 | ** ^If this routine has not been previously called or if the previous |
2417 | ** call had N less than one, then the PRNG is seeded using randomness |
2418 | ** obtained from the xRandomness method of the default [sqlite3_vfs] object. |
2419 | ** ^If the previous call to this routine had an N of 1 or more then |
2420 | ** the pseudo-randomness is generated |
2421 | ** internally and without recourse to the [sqlite3_vfs] xRandomness |
2422 | ** method. |
2423 | */ |
2424 | SQLITE_API void sqlite3_randomness(int N, void *P); |
2425 | |
2426 | /* |
2427 | ** CAPI3REF: Compile-Time Authorization Callbacks |
2428 | ** |
2429 | ** ^This routine registers an authorizer callback with a particular |
2430 | ** [database connection], supplied in the first argument. |
2431 | ** ^The authorizer callback is invoked as SQL statements are being compiled |
2432 | ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], |
2433 | ** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various |
2434 | ** points during the compilation process, as logic is being created |
2435 | ** to perform various actions, the authorizer callback is invoked to |
2436 | ** see if those actions are allowed. ^The authorizer callback should |
2437 | ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the |
2438 | ** specific action but allow the SQL statement to continue to be |
2439 | ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be |
2440 | ** rejected with an error. ^If the authorizer callback returns |
2441 | ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] |
2442 | ** then the [sqlite3_prepare_v2()] or equivalent call that triggered |
2443 | ** the authorizer will fail with an error message. |
2444 | ** |
2445 | ** When the callback returns [SQLITE_OK], that means the operation |
2446 | ** requested is ok. ^When the callback returns [SQLITE_DENY], the |
2447 | ** [sqlite3_prepare_v2()] or equivalent call that triggered the |
2448 | ** authorizer will fail with an error message explaining that |
2449 | ** access is denied. |
2450 | ** |
2451 | ** ^The first parameter to the authorizer callback is a copy of the third |
2452 | ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter |
2453 | ** to the callback is an integer [SQLITE_COPY | action code] that specifies |
2454 | ** the particular action to be authorized. ^The third through sixth parameters |
2455 | ** to the callback are zero-terminated strings that contain additional |
2456 | ** details about the action to be authorized. |
2457 | ** |
2458 | ** ^If the action code is [SQLITE_READ] |
2459 | ** and the callback returns [SQLITE_IGNORE] then the |
2460 | ** [prepared statement] statement is constructed to substitute |
2461 | ** a NULL value in place of the table column that would have |
2462 | ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] |
2463 | ** return can be used to deny an untrusted user access to individual |
2464 | ** columns of a table. |
2465 | ** ^If the action code is [SQLITE_DELETE] and the callback returns |
2466 | ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the |
2467 | ** [truncate optimization] is disabled and all rows are deleted individually. |
2468 | ** |
2469 | ** An authorizer is used when [sqlite3_prepare | preparing] |
2470 | ** SQL statements from an untrusted source, to ensure that the SQL statements |
2471 | ** do not try to access data they are not allowed to see, or that they do not |
2472 | ** try to execute malicious statements that damage the database. For |
2473 | ** example, an application may allow a user to enter arbitrary |
2474 | ** SQL queries for evaluation by a database. But the application does |
2475 | ** not want the user to be able to make arbitrary changes to the |
2476 | ** database. An authorizer could then be put in place while the |
2477 | ** user-entered SQL is being [sqlite3_prepare | prepared] that |
2478 | ** disallows everything except [SELECT] statements. |
2479 | ** |
2480 | ** Applications that need to process SQL from untrusted sources |
2481 | ** might also consider lowering resource limits using [sqlite3_limit()] |
2482 | ** and limiting database size using the [max_page_count] [PRAGMA] |
2483 | ** in addition to using an authorizer. |
2484 | ** |
2485 | ** ^(Only a single authorizer can be in place on a database connection |
2486 | ** at a time. Each call to sqlite3_set_authorizer overrides the |
2487 | ** previous call.)^ ^Disable the authorizer by installing a NULL callback. |
2488 | ** The authorizer is disabled by default. |
2489 | ** |
2490 | ** The authorizer callback must not do anything that will modify |
2491 | ** the database connection that invoked the authorizer callback. |
2492 | ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their |
2493 | ** database connections for the meaning of "modify" in this paragraph. |
2494 | ** |
2495 | ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the |
2496 | ** statement might be re-prepared during [sqlite3_step()] due to a |
2497 | ** schema change. Hence, the application should ensure that the |
2498 | ** correct authorizer callback remains in place during the [sqlite3_step()]. |
2499 | ** |
2500 | ** ^Note that the authorizer callback is invoked only during |
2501 | ** [sqlite3_prepare()] or its variants. Authorization is not |
2502 | ** performed during statement evaluation in [sqlite3_step()], unless |
2503 | ** as stated in the previous paragraph, sqlite3_step() invokes |
2504 | ** sqlite3_prepare_v2() to reprepare a statement after a schema change. |
2505 | */ |
2506 | SQLITE_API int sqlite3_set_authorizer( |
2507 | sqlite3*, |
2508 | int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), |
2509 | void *pUserData |
2510 | ); |
2511 | |
2512 | /* |
2513 | ** CAPI3REF: Authorizer Return Codes |
2514 | ** |
2515 | ** The [sqlite3_set_authorizer | authorizer callback function] must |
2516 | ** return either [SQLITE_OK] or one of these two constants in order |
2517 | ** to signal SQLite whether or not the action is permitted. See the |
2518 | ** [sqlite3_set_authorizer | authorizer documentation] for additional |
2519 | ** information. |
2520 | ** |
2521 | ** Note that SQLITE_IGNORE is also used as a [SQLITE_ROLLBACK | return code] |
2522 | ** from the [sqlite3_vtab_on_conflict()] interface. |
2523 | */ |
2524 | #define SQLITE_DENY 1 /* Abort the SQL statement with an error */ |
2525 | #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ |
2526 | |
2527 | /* |
2528 | ** CAPI3REF: Authorizer Action Codes |
2529 | ** |
2530 | ** The [sqlite3_set_authorizer()] interface registers a callback function |
2531 | ** that is invoked to authorize certain SQL statement actions. The |
2532 | ** second parameter to the callback is an integer code that specifies |
2533 | ** what action is being authorized. These are the integer action codes that |
2534 | ** the authorizer callback may be passed. |
2535 | ** |
2536 | ** These action code values signify what kind of operation is to be |
2537 | ** authorized. The 3rd and 4th parameters to the authorization |
2538 | ** callback function will be parameters or NULL depending on which of these |
2539 | ** codes is used as the second parameter. ^(The 5th parameter to the |
2540 | ** authorizer callback is the name of the database ("main", "temp", |
2541 | ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback |
2542 | ** is the name of the inner-most trigger or view that is responsible for |
2543 | ** the access attempt or NULL if this access attempt is directly from |
2544 | ** top-level SQL code. |
2545 | */ |
2546 | /******************************************* 3rd ************ 4th ***********/ |
2547 | #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ |
2548 | #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ |
2549 | #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ |
2550 | #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ |
2551 | #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ |
2552 | #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ |
2553 | #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ |
2554 | #define SQLITE_CREATE_VIEW 8 /* View Name NULL */ |
2555 | #define SQLITE_DELETE 9 /* Table Name NULL */ |
2556 | #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ |
2557 | #define SQLITE_DROP_TABLE 11 /* Table Name NULL */ |
2558 | #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ |
2559 | #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ |
2560 | #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ |
2561 | #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ |
2562 | #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ |
2563 | #define SQLITE_DROP_VIEW 17 /* View Name NULL */ |
2564 | #define SQLITE_INSERT 18 /* Table Name NULL */ |
2565 | #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ |
2566 | #define SQLITE_READ 20 /* Table Name Column Name */ |
2567 | #define SQLITE_SELECT 21 /* NULL NULL */ |
2568 | #define SQLITE_TRANSACTION 22 /* Operation NULL */ |
2569 | #define SQLITE_UPDATE 23 /* Table Name Column Name */ |
2570 | #define SQLITE_ATTACH 24 /* Filename NULL */ |
2571 | #define SQLITE_DETACH 25 /* Database Name NULL */ |
2572 | #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ |
2573 | #define SQLITE_REINDEX 27 /* Index Name NULL */ |
2574 | #define SQLITE_ANALYZE 28 /* Table Name NULL */ |
2575 | #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ |
2576 | #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ |
2577 | #define SQLITE_FUNCTION 31 /* NULL Function Name */ |
2578 | #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ |
2579 | #define SQLITE_COPY 0 /* No longer used */ |
2580 | #define SQLITE_RECURSIVE 33 /* NULL NULL */ |
2581 | |
2582 | /* |
2583 | ** CAPI3REF: Tracing And Profiling Functions |
2584 | ** |
2585 | ** These routines register callback functions that can be used for |
2586 | ** tracing and profiling the execution of SQL statements. |
2587 | ** |
2588 | ** ^The callback function registered by sqlite3_trace() is invoked at |
2589 | ** various times when an SQL statement is being run by [sqlite3_step()]. |
2590 | ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the |
2591 | ** SQL statement text as the statement first begins executing. |
2592 | ** ^(Additional sqlite3_trace() callbacks might occur |
2593 | ** as each triggered subprogram is entered. The callbacks for triggers |
2594 | ** contain a UTF-8 SQL comment that identifies the trigger.)^ |
2595 | ** |
2596 | ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit |
2597 | ** the length of [bound parameter] expansion in the output of sqlite3_trace(). |
2598 | ** |
2599 | ** ^The callback function registered by sqlite3_profile() is invoked |
2600 | ** as each SQL statement finishes. ^The profile callback contains |
2601 | ** the original statement text and an estimate of wall-clock time |
2602 | ** of how long that statement took to run. ^The profile callback |
2603 | ** time is in units of nanoseconds, however the current implementation |
2604 | ** is only capable of millisecond resolution so the six least significant |
2605 | ** digits in the time are meaningless. Future versions of SQLite |
2606 | ** might provide greater resolution on the profiler callback. The |
2607 | ** sqlite3_profile() function is considered experimental and is |
2608 | ** subject to change in future versions of SQLite. |
2609 | */ |
2610 | SQLITE_API void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*); |
2611 | SQLITE_API SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*, |
2612 | void(*xProfile)(void*,const char*,sqlite3_uint64), void*); |
2613 | |
2614 | /* |
2615 | ** CAPI3REF: Query Progress Callbacks |
2616 | ** |
2617 | ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback |
2618 | ** function X to be invoked periodically during long running calls to |
2619 | ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for |
2620 | ** database connection D. An example use for this |
2621 | ** interface is to keep a GUI updated during a large query. |
2622 | ** |
2623 | ** ^The parameter P is passed through as the only parameter to the |
2624 | ** callback function X. ^The parameter N is the approximate number of |
2625 | ** [virtual machine instructions] that are evaluated between successive |
2626 | ** invocations of the callback X. ^If N is less than one then the progress |
2627 | ** handler is disabled. |
2628 | ** |
2629 | ** ^Only a single progress handler may be defined at one time per |
2630 | ** [database connection]; setting a new progress handler cancels the |
2631 | ** old one. ^Setting parameter X to NULL disables the progress handler. |
2632 | ** ^The progress handler is also disabled by setting N to a value less |
2633 | ** than 1. |
2634 | ** |
2635 | ** ^If the progress callback returns non-zero, the operation is |
2636 | ** interrupted. This feature can be used to implement a |
2637 | ** "Cancel" button on a GUI progress dialog box. |
2638 | ** |
2639 | ** The progress handler callback must not do anything that will modify |
2640 | ** the database connection that invoked the progress handler. |
2641 | ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their |
2642 | ** database connections for the meaning of "modify" in this paragraph. |
2643 | ** |
2644 | */ |
2645 | SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); |
2646 | |
2647 | /* |
2648 | ** CAPI3REF: Opening A New Database Connection |
2649 | ** |
2650 | ** ^These routines open an SQLite database file as specified by the |
2651 | ** filename argument. ^The filename argument is interpreted as UTF-8 for |
2652 | ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte |
2653 | ** order for sqlite3_open16(). ^(A [database connection] handle is usually |
2654 | ** returned in *ppDb, even if an error occurs. The only exception is that |
2655 | ** if SQLite is unable to allocate memory to hold the [sqlite3] object, |
2656 | ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] |
2657 | ** object.)^ ^(If the database is opened (and/or created) successfully, then |
2658 | ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The |
2659 | ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain |
2660 | ** an English language description of the error following a failure of any |
2661 | ** of the sqlite3_open() routines. |
2662 | ** |
2663 | ** ^The default encoding for the database will be UTF-8 if |
2664 | ** sqlite3_open() or sqlite3_open_v2() is called and |
2665 | ** UTF-16 in the native byte order if sqlite3_open16() is used. |
2666 | ** |
2667 | ** Whether or not an error occurs when it is opened, resources |
2668 | ** associated with the [database connection] handle should be released by |
2669 | ** passing it to [sqlite3_close()] when it is no longer required. |
2670 | ** |
2671 | ** The sqlite3_open_v2() interface works like sqlite3_open() |
2672 | ** except that it accepts two additional parameters for additional control |
2673 | ** over the new database connection. ^(The flags parameter to |
2674 | ** sqlite3_open_v2() can take one of |
2675 | ** the following three values, optionally combined with the |
2676 | ** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], |
2677 | ** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ |
2678 | ** |
2679 | ** <dl> |
2680 | ** ^(<dt>[SQLITE_OPEN_READONLY]</dt> |
2681 | ** <dd>The database is opened in read-only mode. If the database does not |
2682 | ** already exist, an error is returned.</dd>)^ |
2683 | ** |
2684 | ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> |
2685 | ** <dd>The database is opened for reading and writing if possible, or reading |
2686 | ** only if the file is write protected by the operating system. In either |
2687 | ** case the database must already exist, otherwise an error is returned.</dd>)^ |
2688 | ** |
2689 | ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> |
2690 | ** <dd>The database is opened for reading and writing, and is created if |
2691 | ** it does not already exist. This is the behavior that is always used for |
2692 | ** sqlite3_open() and sqlite3_open16().</dd>)^ |
2693 | ** </dl> |
2694 | ** |
2695 | ** If the 3rd parameter to sqlite3_open_v2() is not one of the |
2696 | ** combinations shown above optionally combined with other |
2697 | ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] |
2698 | ** then the behavior is undefined. |
2699 | ** |
2700 | ** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection |
2701 | ** opens in the multi-thread [threading mode] as long as the single-thread |
2702 | ** mode has not been set at compile-time or start-time. ^If the |
2703 | ** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens |
2704 | ** in the serialized [threading mode] unless single-thread was |
2705 | ** previously selected at compile-time or start-time. |
2706 | ** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be |
2707 | ** eligible to use [shared cache mode], regardless of whether or not shared |
2708 | ** cache is enabled using [sqlite3_enable_shared_cache()]. ^The |
2709 | ** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not |
2710 | ** participate in [shared cache mode] even if it is enabled. |
2711 | ** |
2712 | ** ^The fourth parameter to sqlite3_open_v2() is the name of the |
2713 | ** [sqlite3_vfs] object that defines the operating system interface that |
2714 | ** the new database connection should use. ^If the fourth parameter is |
2715 | ** a NULL pointer then the default [sqlite3_vfs] object is used. |
2716 | ** |
2717 | ** ^If the filename is ":memory:", then a private, temporary in-memory database |
2718 | ** is created for the connection. ^This in-memory database will vanish when |
2719 | ** the database connection is closed. Future versions of SQLite might |
2720 | ** make use of additional special filenames that begin with the ":" character. |
2721 | ** It is recommended that when a database filename actually does begin with |
2722 | ** a ":" character you should prefix the filename with a pathname such as |
2723 | ** "./" to avoid ambiguity. |
2724 | ** |
2725 | ** ^If the filename is an empty string, then a private, temporary |
2726 | ** on-disk database will be created. ^This private database will be |
2727 | ** automatically deleted as soon as the database connection is closed. |
2728 | ** |
2729 | ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> |
2730 | ** |
2731 | ** ^If [URI filename] interpretation is enabled, and the filename argument |
2732 | ** begins with "file:", then the filename is interpreted as a URI. ^URI |
2733 | ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is |
2734 | ** set in the fourth argument to sqlite3_open_v2(), or if it has |
2735 | ** been enabled globally using the [SQLITE_CONFIG_URI] option with the |
2736 | ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. |
2737 | ** As of SQLite version 3.7.7, URI filename interpretation is turned off |
2738 | ** by default, but future releases of SQLite might enable URI filename |
2739 | ** interpretation by default. See "[URI filenames]" for additional |
2740 | ** information. |
2741 | ** |
2742 | ** URI filenames are parsed according to RFC 3986. ^If the URI contains an |
2743 | ** authority, then it must be either an empty string or the string |
2744 | ** "localhost". ^If the authority is not an empty string or "localhost", an |
2745 | ** error is returned to the caller. ^The fragment component of a URI, if |
2746 | ** present, is ignored. |
2747 | ** |
2748 | ** ^SQLite uses the path component of the URI as the name of the disk file |
2749 | ** which contains the database. ^If the path begins with a '/' character, |
2750 | ** then it is interpreted as an absolute path. ^If the path does not begin |
2751 | ** with a '/' (meaning that the authority section is omitted from the URI) |
2752 | ** then the path is interpreted as a relative path. |
2753 | ** ^On windows, the first component of an absolute path |
2754 | ** is a drive specification (e.g. "C:"). |
2755 | ** |
2756 | ** [[core URI query parameters]] |
2757 | ** The query component of a URI may contain parameters that are interpreted |
2758 | ** either by SQLite itself, or by a [VFS | custom VFS implementation]. |
2759 | ** SQLite interprets the following three query parameters: |
2760 | ** |
2761 | ** <ul> |
2762 | ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of |
2763 | ** a VFS object that provides the operating system interface that should |
2764 | ** be used to access the database file on disk. ^If this option is set to |
2765 | ** an empty string the default VFS object is used. ^Specifying an unknown |
2766 | ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is |
2767 | ** present, then the VFS specified by the option takes precedence over |
2768 | ** the value passed as the fourth parameter to sqlite3_open_v2(). |
2769 | ** |
2770 | ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", |
2771 | ** "rwc", or "memory". Attempting to set it to any other value is |
2772 | ** an error)^. |
2773 | ** ^If "ro" is specified, then the database is opened for read-only |
2774 | ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the |
2775 | ** third argument to sqlite3_open_v2(). ^If the mode option is set to |
2776 | ** "rw", then the database is opened for read-write (but not create) |
2777 | ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had |
2778 | ** been set. ^Value "rwc" is equivalent to setting both |
2779 | ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is |
2780 | ** set to "memory" then a pure [in-memory database] that never reads |
2781 | ** or writes from disk is used. ^It is an error to specify a value for |
2782 | ** the mode parameter that is less restrictive than that specified by |
2783 | ** the flags passed in the third parameter to sqlite3_open_v2(). |
2784 | ** |
2785 | ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or |
2786 | ** "private". ^Setting it to "shared" is equivalent to setting the |
2787 | ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to |
2788 | ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is |
2789 | ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. |
2790 | ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in |
2791 | ** a URI filename, its value overrides any behavior requested by setting |
2792 | ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. |
2793 | ** |
2794 | ** <li> <b>psow</b>: ^The psow parameter may be "true" (or "on" or "yes" or |
2795 | ** "1") or "false" (or "off" or "no" or "0") to indicate that the |
2796 | ** [powersafe overwrite] property does or does not apply to the |
2797 | ** storage media on which the database file resides. ^The psow query |
2798 | ** parameter only works for the built-in unix and Windows VFSes. |
2799 | ** |
2800 | ** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter |
2801 | ** which if set disables file locking in rollback journal modes. This |
2802 | ** is useful for accessing a database on a filesystem that does not |
2803 | ** support locking. Caution: Database corruption might result if two |
2804 | ** or more processes write to the same database and any one of those |
2805 | ** processes uses nolock=1. |
2806 | ** |
2807 | ** <li> <b>immutable</b>: ^The immutable parameter is a boolean query |
2808 | ** parameter that indicates that the database file is stored on |
2809 | ** read-only media. ^When immutable is set, SQLite assumes that the |
2810 | ** database file cannot be changed, even by a process with higher |
2811 | ** privilege, and so the database is opened read-only and all locking |
2812 | ** and change detection is disabled. Caution: Setting the immutable |
2813 | ** property on a database file that does in fact change can result |
2814 | ** in incorrect query results and/or [SQLITE_CORRUPT] errors. |
2815 | ** See also: [SQLITE_IOCAP_IMMUTABLE]. |
2816 | ** |
2817 | ** </ul> |
2818 | ** |
2819 | ** ^Specifying an unknown parameter in the query component of a URI is not an |
2820 | ** error. Future versions of SQLite might understand additional query |
2821 | ** parameters. See "[query parameters with special meaning to SQLite]" for |
2822 | ** additional information. |
2823 | ** |
2824 | ** [[URI filename examples]] <h3>URI filename examples</h3> |
2825 | ** |
2826 | ** <table border="1" align=center cellpadding=5> |
2827 | ** <tr><th> URI filenames <th> Results |
2828 | ** <tr><td> file:data.db <td> |
2829 | ** Open the file "data.db" in the current directory. |
2830 | ** <tr><td> file:/home/fred/data.db<br> |
2831 | ** file:///home/fred/data.db <br> |
2832 | ** file://localhost/home/fred/data.db <br> <td> |
2833 | ** Open the database file "/home/fred/data.db". |
2834 | ** <tr><td> file://darkstar/home/fred/data.db <td> |
2835 | ** An error. "darkstar" is not a recognized authority. |
2836 | ** <tr><td style="white-space:nowrap"> |
2837 | ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db |
2838 | ** <td> Windows only: Open the file "data.db" on fred's desktop on drive |
2839 | ** C:. Note that the %20 escaping in this example is not strictly |
2840 | ** necessary - space characters can be used literally |
2841 | ** in URI filenames. |
2842 | ** <tr><td> file:data.db?mode=ro&cache=private <td> |
2843 | ** Open file "data.db" in the current directory for read-only access. |
2844 | ** Regardless of whether or not shared-cache mode is enabled by |
2845 | ** default, use a private cache. |
2846 | ** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> |
2847 | ** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" |
2848 | ** that uses dot-files in place of posix advisory locking. |
2849 | ** <tr><td> file:data.db?mode=readonly <td> |
2850 | ** An error. "readonly" is not a valid option for the "mode" parameter. |
2851 | ** </table> |
2852 | ** |
2853 | ** ^URI hexadecimal escape sequences (%HH) are supported within the path and |
2854 | ** query components of a URI. A hexadecimal escape sequence consists of a |
2855 | ** percent sign - "%" - followed by exactly two hexadecimal digits |
2856 | ** specifying an octet value. ^Before the path or query components of a |
2857 | ** URI filename are interpreted, they are encoded using UTF-8 and all |
2858 | ** hexadecimal escape sequences replaced by a single byte containing the |
2859 | ** corresponding octet. If this process generates an invalid UTF-8 encoding, |
2860 | ** the results are undefined. |
2861 | ** |
2862 | ** <b>Note to Windows users:</b> The encoding used for the filename argument |
2863 | ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever |
2864 | ** codepage is currently defined. Filenames containing international |
2865 | ** characters must be converted to UTF-8 prior to passing them into |
2866 | ** sqlite3_open() or sqlite3_open_v2(). |
2867 | ** |
2868 | ** <b>Note to Windows Runtime users:</b> The temporary directory must be set |
2869 | ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various |
2870 | ** features that require the use of temporary files may fail. |
2871 | ** |
2872 | ** See also: [sqlite3_temp_directory] |
2873 | */ |
2874 | SQLITE_API int sqlite3_open( |
2875 | const char *filename, /* Database filename (UTF-8) */ |
2876 | sqlite3 **ppDb /* OUT: SQLite db handle */ |
2877 | ); |
2878 | SQLITE_API int sqlite3_open16( |
2879 | const void *filename, /* Database filename (UTF-16) */ |
2880 | sqlite3 **ppDb /* OUT: SQLite db handle */ |
2881 | ); |
2882 | SQLITE_API int sqlite3_open_v2( |
2883 | const char *filename, /* Database filename (UTF-8) */ |
2884 | sqlite3 **ppDb, /* OUT: SQLite db handle */ |
2885 | int flags, /* Flags */ |
2886 | const char *zVfs /* Name of VFS module to use */ |
2887 | ); |
2888 | |
2889 | /* |
2890 | ** CAPI3REF: Obtain Values For URI Parameters |
2891 | ** |
2892 | ** These are utility routines, useful to VFS implementations, that check |
2893 | ** to see if a database file was a URI that contained a specific query |
2894 | ** parameter, and if so obtains the value of that query parameter. |
2895 | ** |
2896 | ** If F is the database filename pointer passed into the xOpen() method of |
2897 | ** a VFS implementation when the flags parameter to xOpen() has one or |
2898 | ** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and |
2899 | ** P is the name of the query parameter, then |
2900 | ** sqlite3_uri_parameter(F,P) returns the value of the P |
2901 | ** parameter if it exists or a NULL pointer if P does not appear as a |
2902 | ** query parameter on F. If P is a query parameter of F |
2903 | ** has no explicit value, then sqlite3_uri_parameter(F,P) returns |
2904 | ** a pointer to an empty string. |
2905 | ** |
2906 | ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean |
2907 | ** parameter and returns true (1) or false (0) according to the value |
2908 | ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the |
2909 | ** value of query parameter P is one of "yes", "true", or "on" in any |
2910 | ** case or if the value begins with a non-zero number. The |
2911 | ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of |
2912 | ** query parameter P is one of "no", "false", or "off" in any case or |
2913 | ** if the value begins with a numeric zero. If P is not a query |
2914 | ** parameter on F or if the value of P is does not match any of the |
2915 | ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). |
2916 | ** |
2917 | ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a |
2918 | ** 64-bit signed integer and returns that integer, or D if P does not |
2919 | ** exist. If the value of P is something other than an integer, then |
2920 | ** zero is returned. |
2921 | ** |
2922 | ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and |
2923 | ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and |
2924 | ** is not a database file pathname pointer that SQLite passed into the xOpen |
2925 | ** VFS method, then the behavior of this routine is undefined and probably |
2926 | ** undesirable. |
2927 | */ |
2928 | SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); |
2929 | SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); |
2930 | SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); |
2931 | |
2932 | |
2933 | /* |
2934 | ** CAPI3REF: Error Codes And Messages |
2935 | ** |
2936 | ** ^The sqlite3_errcode() interface returns the numeric [result code] or |
2937 | ** [extended result code] for the most recent failed sqlite3_* API call |
2938 | ** associated with a [database connection]. If a prior API call failed |
2939 | ** but the most recent API call succeeded, the return value from |
2940 | ** sqlite3_errcode() is undefined. ^The sqlite3_extended_errcode() |
2941 | ** interface is the same except that it always returns the |
2942 | ** [extended result code] even when extended result codes are |
2943 | ** disabled. |
2944 | ** |
2945 | ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language |
2946 | ** text that describes the error, as either UTF-8 or UTF-16 respectively. |
2947 | ** ^(Memory to hold the error message string is managed internally. |
2948 | ** The application does not need to worry about freeing the result. |
2949 | ** However, the error string might be overwritten or deallocated by |
2950 | ** subsequent calls to other SQLite interface functions.)^ |
2951 | ** |
2952 | ** ^The sqlite3_errstr() interface returns the English-language text |
2953 | ** that describes the [result code], as UTF-8. |
2954 | ** ^(Memory to hold the error message string is managed internally |
2955 | ** and must not be freed by the application)^. |
2956 | ** |
2957 | ** When the serialized [threading mode] is in use, it might be the |
2958 | ** case that a second error occurs on a separate thread in between |
2959 | ** the time of the first error and the call to these interfaces. |
2960 | ** When that happens, the second error will be reported since these |
2961 | ** interfaces always report the most recent result. To avoid |
2962 | ** this, each thread can obtain exclusive use of the [database connection] D |
2963 | ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning |
2964 | ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after |
2965 | ** all calls to the interfaces listed here are completed. |
2966 | ** |
2967 | ** If an interface fails with SQLITE_MISUSE, that means the interface |
2968 | ** was invoked incorrectly by the application. In that case, the |
2969 | ** error code and message may or may not be set. |
2970 | */ |
2971 | SQLITE_API int sqlite3_errcode(sqlite3 *db); |
2972 | SQLITE_API int sqlite3_extended_errcode(sqlite3 *db); |
2973 | SQLITE_API const char *sqlite3_errmsg(sqlite3*); |
2974 | SQLITE_API const void *sqlite3_errmsg16(sqlite3*); |
2975 | SQLITE_API const char *sqlite3_errstr(int); |
2976 | |
2977 | /* |
2978 | ** CAPI3REF: SQL Statement Object |
2979 | ** KEYWORDS: {prepared statement} {prepared statements} |
2980 | ** |
2981 | ** An instance of this object represents a single SQL statement. |
2982 | ** This object is variously known as a "prepared statement" or a |
2983 | ** "compiled SQL statement" or simply as a "statement". |
2984 | ** |
2985 | ** The life of a statement object goes something like this: |
2986 | ** |
2987 | ** <ol> |
2988 | ** <li> Create the object using [sqlite3_prepare_v2()] or a related |
2989 | ** function. |
2990 | ** <li> Bind values to [host parameters] using the sqlite3_bind_*() |
2991 | ** interfaces. |
2992 | ** <li> Run the SQL by calling [sqlite3_step()] one or more times. |
2993 | ** <li> Reset the statement using [sqlite3_reset()] then go back |
2994 | ** to step 2. Do this zero or more times. |
2995 | ** <li> Destroy the object using [sqlite3_finalize()]. |
2996 | ** </ol> |
2997 | ** |
2998 | ** Refer to documentation on individual methods above for additional |
2999 | ** information. |
3000 | */ |
3001 | typedef struct sqlite3_stmt sqlite3_stmt; |
3002 | |
3003 | /* |
3004 | ** CAPI3REF: Run-time Limits |
3005 | ** |
3006 | ** ^(This interface allows the size of various constructs to be limited |
3007 | ** on a connection by connection basis. The first parameter is the |
3008 | ** [database connection] whose limit is to be set or queried. The |
3009 | ** second parameter is one of the [limit categories] that define a |
3010 | ** class of constructs to be size limited. The third parameter is the |
3011 | ** new limit for that construct.)^ |
3012 | ** |
3013 | ** ^If the new limit is a negative number, the limit is unchanged. |
3014 | ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a |
3015 | ** [limits | hard upper bound] |
3016 | ** set at compile-time by a C preprocessor macro called |
3017 | ** [limits | SQLITE_MAX_<i>NAME</i>]. |
3018 | ** (The "_LIMIT_" in the name is changed to "_MAX_".))^ |
3019 | ** ^Attempts to increase a limit above its hard upper bound are |
3020 | ** silently truncated to the hard upper bound. |
3021 | ** |
3022 | ** ^Regardless of whether or not the limit was changed, the |
3023 | ** [sqlite3_limit()] interface returns the prior value of the limit. |
3024 | ** ^Hence, to find the current value of a limit without changing it, |
3025 | ** simply invoke this interface with the third parameter set to -1. |
3026 | ** |
3027 | ** Run-time limits are intended for use in applications that manage |
3028 | ** both their own internal database and also databases that are controlled |
3029 | ** by untrusted external sources. An example application might be a |
3030 | ** web browser that has its own databases for storing history and |
3031 | ** separate databases controlled by JavaScript applications downloaded |
3032 | ** off the Internet. The internal databases can be given the |
3033 | ** large, default limits. Databases managed by external sources can |
3034 | ** be given much smaller limits designed to prevent a denial of service |
3035 | ** attack. Developers might also want to use the [sqlite3_set_authorizer()] |
3036 | ** interface to further control untrusted SQL. The size of the database |
3037 | ** created by an untrusted script can be contained using the |
3038 | ** [max_page_count] [PRAGMA]. |
3039 | ** |
3040 | ** New run-time limit categories may be added in future releases. |
3041 | */ |
3042 | SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal); |
3043 | |
3044 | /* |
3045 | ** CAPI3REF: Run-Time Limit Categories |
3046 | ** KEYWORDS: {limit category} {*limit categories} |
3047 | ** |
3048 | ** These constants define various performance limits |
3049 | ** that can be lowered at run-time using [sqlite3_limit()]. |
3050 | ** The synopsis of the meanings of the various limits is shown below. |
3051 | ** Additional information is available at [limits | Limits in SQLite]. |
3052 | ** |
3053 | ** <dl> |
3054 | ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> |
3055 | ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ |
3056 | ** |
3057 | ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> |
3058 | ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ |
3059 | ** |
3060 | ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> |
3061 | ** <dd>The maximum number of columns in a table definition or in the |
3062 | ** result set of a [SELECT] or the maximum number of columns in an index |
3063 | ** or in an ORDER BY or GROUP BY clause.</dd>)^ |
3064 | ** |
3065 | ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> |
3066 | ** <dd>The maximum depth of the parse tree on any expression.</dd>)^ |
3067 | ** |
3068 | ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> |
3069 | ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ |
3070 | ** |
3071 | ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> |
3072 | ** <dd>The maximum number of instructions in a virtual machine program |
3073 | ** used to implement an SQL statement. This limit is not currently |
3074 | ** enforced, though that might be added in some future release of |
3075 | ** SQLite.</dd>)^ |
3076 | ** |
3077 | ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> |
3078 | ** <dd>The maximum number of arguments on a function.</dd>)^ |
3079 | ** |
3080 | ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> |
3081 | ** <dd>The maximum number of [ATTACH | attached databases].)^</dd> |
3082 | ** |
3083 | ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] |
3084 | ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> |
3085 | ** <dd>The maximum length of the pattern argument to the [LIKE] or |
3086 | ** [GLOB] operators.</dd>)^ |
3087 | ** |
3088 | ** [[SQLITE_LIMIT_VARIABLE_NUMBER]] |
3089 | ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> |
3090 | ** <dd>The maximum index number of any [parameter] in an SQL statement.)^ |
3091 | ** |
3092 | ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> |
3093 | ** <dd>The maximum depth of recursion for triggers.</dd>)^ |
3094 | ** </dl> |
3095 | */ |
3096 | #define SQLITE_LIMIT_LENGTH 0 |
3097 | #define SQLITE_LIMIT_SQL_LENGTH 1 |
3098 | #define SQLITE_LIMIT_COLUMN 2 |
3099 | #define SQLITE_LIMIT_EXPR_DEPTH 3 |
3100 | #define SQLITE_LIMIT_COMPOUND_SELECT 4 |
3101 | #define SQLITE_LIMIT_VDBE_OP 5 |
3102 | #define SQLITE_LIMIT_FUNCTION_ARG 6 |
3103 | #define SQLITE_LIMIT_ATTACHED 7 |
3104 | #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 |
3105 | #define SQLITE_LIMIT_VARIABLE_NUMBER 9 |
3106 | #define SQLITE_LIMIT_TRIGGER_DEPTH 10 |
3107 | |
3108 | /* |
3109 | ** CAPI3REF: Compiling An SQL Statement |
3110 | ** KEYWORDS: {SQL statement compiler} |
3111 | ** |
3112 | ** To execute an SQL query, it must first be compiled into a byte-code |
3113 | ** program using one of these routines. |
3114 | ** |
3115 | ** The first argument, "db", is a [database connection] obtained from a |
3116 | ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or |
3117 | ** [sqlite3_open16()]. The database connection must not have been closed. |
3118 | ** |
3119 | ** The second argument, "zSql", is the statement to be compiled, encoded |
3120 | ** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() |
3121 | ** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2() |
3122 | ** use UTF-16. |
3123 | ** |
3124 | ** ^If the nByte argument is less than zero, then zSql is read up to the |
3125 | ** first zero terminator. ^If nByte is non-negative, then it is the maximum |
3126 | ** number of bytes read from zSql. ^When nByte is non-negative, the |
3127 | ** zSql string ends at either the first '\000' or '\u0000' character or |
3128 | ** the nByte-th byte, whichever comes first. If the caller knows |
3129 | ** that the supplied string is nul-terminated, then there is a small |
3130 | ** performance advantage to be gained by passing an nByte parameter that |
3131 | ** is equal to the number of bytes in the input string <i>including</i> |
3132 | ** the nul-terminator bytes as this saves SQLite from having to |
3133 | ** make a copy of the input string. |
3134 | ** |
3135 | ** ^If pzTail is not NULL then *pzTail is made to point to the first byte |
3136 | ** past the end of the first SQL statement in zSql. These routines only |
3137 | ** compile the first statement in zSql, so *pzTail is left pointing to |
3138 | ** what remains uncompiled. |
3139 | ** |
3140 | ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be |
3141 | ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set |
3142 | ** to NULL. ^If the input text contains no SQL (if the input is an empty |
3143 | ** string or a comment) then *ppStmt is set to NULL. |
3144 | ** The calling procedure is responsible for deleting the compiled |
3145 | ** SQL statement using [sqlite3_finalize()] after it has finished with it. |
3146 | ** ppStmt may not be NULL. |
3147 | ** |
3148 | ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; |
3149 | ** otherwise an [error code] is returned. |
3150 | ** |
3151 | ** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are |
3152 | ** recommended for all new programs. The two older interfaces are retained |
3153 | ** for backwards compatibility, but their use is discouraged. |
3154 | ** ^In the "v2" interfaces, the prepared statement |
3155 | ** that is returned (the [sqlite3_stmt] object) contains a copy of the |
3156 | ** original SQL text. This causes the [sqlite3_step()] interface to |
3157 | ** behave differently in three ways: |
3158 | ** |
3159 | ** <ol> |
3160 | ** <li> |
3161 | ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it |
3162 | ** always used to do, [sqlite3_step()] will automatically recompile the SQL |
3163 | ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] |
3164 | ** retries will occur before sqlite3_step() gives up and returns an error. |
3165 | ** </li> |
3166 | ** |
3167 | ** <li> |
3168 | ** ^When an error occurs, [sqlite3_step()] will return one of the detailed |
3169 | ** [error codes] or [extended error codes]. ^The legacy behavior was that |
3170 | ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code |
3171 | ** and the application would have to make a second call to [sqlite3_reset()] |
3172 | ** in order to find the underlying cause of the problem. With the "v2" prepare |
3173 | ** interfaces, the underlying reason for the error is returned immediately. |
3174 | ** </li> |
3175 | ** |
3176 | ** <li> |
3177 | ** ^If the specific value bound to [parameter | host parameter] in the |
3178 | ** WHERE clause might influence the choice of query plan for a statement, |
3179 | ** then the statement will be automatically recompiled, as if there had been |
3180 | ** a schema change, on the first [sqlite3_step()] call following any change |
3181 | ** to the [sqlite3_bind_text | bindings] of that [parameter]. |
3182 | ** ^The specific value of WHERE-clause [parameter] might influence the |
3183 | ** choice of query plan if the parameter is the left-hand side of a [LIKE] |
3184 | ** or [GLOB] operator or if the parameter is compared to an indexed column |
3185 | ** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled. |
3186 | ** </li> |
3187 | ** </ol> |
3188 | */ |
3189 | SQLITE_API int sqlite3_prepare( |
3190 | sqlite3 *db, /* Database handle */ |
3191 | const char *zSql, /* SQL statement, UTF-8 encoded */ |
3192 | int nByte, /* Maximum length of zSql in bytes. */ |
3193 | sqlite3_stmt **ppStmt, /* OUT: Statement handle */ |
3194 | const char **pzTail /* OUT: Pointer to unused portion of zSql */ |
3195 | ); |
3196 | SQLITE_API int sqlite3_prepare_v2( |
3197 | sqlite3 *db, /* Database handle */ |
3198 | const char *zSql, /* SQL statement, UTF-8 encoded */ |
3199 | int nByte, /* Maximum length of zSql in bytes. */ |
3200 | sqlite3_stmt **ppStmt, /* OUT: Statement handle */ |
3201 | const char **pzTail /* OUT: Pointer to unused portion of zSql */ |
3202 | ); |
3203 | SQLITE_API int sqlite3_prepare16( |
3204 | sqlite3 *db, /* Database handle */ |
3205 | const void *zSql, /* SQL statement, UTF-16 encoded */ |
3206 | int nByte, /* Maximum length of zSql in bytes. */ |
3207 | sqlite3_stmt **ppStmt, /* OUT: Statement handle */ |
3208 | const void **pzTail /* OUT: Pointer to unused portion of zSql */ |
3209 | ); |
3210 | SQLITE_API int sqlite3_prepare16_v2( |
3211 | sqlite3 *db, /* Database handle */ |
3212 | const void *zSql, /* SQL statement, UTF-16 encoded */ |
3213 | int nByte, /* Maximum length of zSql in bytes. */ |
3214 | sqlite3_stmt **ppStmt, /* OUT: Statement handle */ |
3215 | const void **pzTail /* OUT: Pointer to unused portion of zSql */ |
3216 | ); |
3217 | |
3218 | /* |
3219 | ** CAPI3REF: Retrieving Statement SQL |
3220 | ** |
3221 | ** ^This interface can be used to retrieve a saved copy of the original |
3222 | ** SQL text used to create a [prepared statement] if that statement was |
3223 | ** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()]. |
3224 | */ |
3225 | SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt); |
3226 | |
3227 | /* |
3228 | ** CAPI3REF: Determine If An SQL Statement Writes The Database |
3229 | ** |
3230 | ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if |
3231 | ** and only if the [prepared statement] X makes no direct changes to |
3232 | ** the content of the database file. |
3233 | ** |
3234 | ** Note that [application-defined SQL functions] or |
3235 | ** [virtual tables] might change the database indirectly as a side effect. |
3236 | ** ^(For example, if an application defines a function "eval()" that |
3237 | ** calls [sqlite3_exec()], then the following SQL statement would |
3238 | ** change the database file through side-effects: |
3239 | ** |
3240 | ** <blockquote><pre> |
3241 | ** SELECT eval('DELETE FROM t1') FROM t2; |
3242 | ** </pre></blockquote> |
3243 | ** |
3244 | ** But because the [SELECT] statement does not change the database file |
3245 | ** directly, sqlite3_stmt_readonly() would still return true.)^ |
3246 | ** |
3247 | ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], |
3248 | ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, |
3249 | ** since the statements themselves do not actually modify the database but |
3250 | ** rather they control the timing of when other statements modify the |
3251 | ** database. ^The [ATTACH] and [DETACH] statements also cause |
3252 | ** sqlite3_stmt_readonly() to return true since, while those statements |
3253 | ** change the configuration of a database connection, they do not make |
3254 | ** changes to the content of the database files on disk. |
3255 | */ |
3256 | SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); |
3257 | |
3258 | /* |
3259 | ** CAPI3REF: Determine If A Prepared Statement Has Been Reset |
3260 | ** |
3261 | ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the |
3262 | ** [prepared statement] S has been stepped at least once using |
3263 | ** [sqlite3_step(S)] but has not run to completion and/or has not |
3264 | ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) |
3265 | ** interface returns false if S is a NULL pointer. If S is not a |
3266 | ** NULL pointer and is not a pointer to a valid [prepared statement] |
3267 | ** object, then the behavior is undefined and probably undesirable. |
3268 | ** |
3269 | ** This interface can be used in combination [sqlite3_next_stmt()] |
3270 | ** to locate all prepared statements associated with a database |
3271 | ** connection that are in need of being reset. This can be used, |
3272 | ** for example, in diagnostic routines to search for prepared |
3273 | ** statements that are holding a transaction open. |
3274 | */ |
3275 | SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*); |
3276 | |
3277 | /* |
3278 | ** CAPI3REF: Dynamically Typed Value Object |
3279 | ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} |
3280 | ** |
3281 | ** SQLite uses the sqlite3_value object to represent all values |
3282 | ** that can be stored in a database table. SQLite uses dynamic typing |
3283 | ** for the values it stores. ^Values stored in sqlite3_value objects |
3284 | ** can be integers, floating point values, strings, BLOBs, or NULL. |
3285 | ** |
3286 | ** An sqlite3_value object may be either "protected" or "unprotected". |
3287 | ** Some interfaces require a protected sqlite3_value. Other interfaces |
3288 | ** will accept either a protected or an unprotected sqlite3_value. |
3289 | ** Every interface that accepts sqlite3_value arguments specifies |
3290 | ** whether or not it requires a protected sqlite3_value. |
3291 | ** |
3292 | ** The terms "protected" and "unprotected" refer to whether or not |
3293 | ** a mutex is held. An internal mutex is held for a protected |
3294 | ** sqlite3_value object but no mutex is held for an unprotected |
3295 | ** sqlite3_value object. If SQLite is compiled to be single-threaded |
3296 | ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) |
3297 | ** or if SQLite is run in one of reduced mutex modes |
3298 | ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] |
3299 | ** then there is no distinction between protected and unprotected |
3300 | ** sqlite3_value objects and they can be used interchangeably. However, |
3301 | ** for maximum code portability it is recommended that applications |
3302 | ** still make the distinction between protected and unprotected |
3303 | ** sqlite3_value objects even when not strictly required. |
3304 | ** |
3305 | ** ^The sqlite3_value objects that are passed as parameters into the |
3306 | ** implementation of [application-defined SQL functions] are protected. |
3307 | ** ^The sqlite3_value object returned by |
3308 | ** [sqlite3_column_value()] is unprotected. |
3309 | ** Unprotected sqlite3_value objects may only be used with |
3310 | ** [sqlite3_result_value()] and [sqlite3_bind_value()]. |
3311 | ** The [sqlite3_value_blob | sqlite3_value_type()] family of |
3312 | ** interfaces require protected sqlite3_value objects. |
3313 | */ |
3314 | typedef struct Mem sqlite3_value; |
3315 | |
3316 | /* |
3317 | ** CAPI3REF: SQL Function Context Object |
3318 | ** |
3319 | ** The context in which an SQL function executes is stored in an |
3320 | ** sqlite3_context object. ^A pointer to an sqlite3_context object |
3321 | ** is always first parameter to [application-defined SQL functions]. |
3322 | ** The application-defined SQL function implementation will pass this |
3323 | ** pointer through into calls to [sqlite3_result_int | sqlite3_result()], |
3324 | ** [sqlite3_aggregate_context()], [sqlite3_user_data()], |
3325 | ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], |
3326 | ** and/or [sqlite3_set_auxdata()]. |
3327 | */ |
3328 | typedef struct sqlite3_context sqlite3_context; |
3329 | |
3330 | /* |
3331 | ** CAPI3REF: Binding Values To Prepared Statements |
3332 | ** KEYWORDS: {host parameter} {host parameters} {host parameter name} |
3333 | ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} |
3334 | ** |
3335 | ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, |
3336 | ** literals may be replaced by a [parameter] that matches one of following |
3337 | ** templates: |
3338 | ** |
3339 | ** <ul> |
3340 | ** <li> ? |
3341 | ** <li> ?NNN |
3342 | ** <li> :VVV |
3343 | ** <li> @VVV |
3344 | ** <li> $VVV |
3345 | ** </ul> |
3346 | ** |
3347 | ** In the templates above, NNN represents an integer literal, |
3348 | ** and VVV represents an alphanumeric identifier.)^ ^The values of these |
3349 | ** parameters (also called "host parameter names" or "SQL parameters") |
3350 | ** can be set using the sqlite3_bind_*() routines defined here. |
3351 | ** |
3352 | ** ^The first argument to the sqlite3_bind_*() routines is always |
3353 | ** a pointer to the [sqlite3_stmt] object returned from |
3354 | ** [sqlite3_prepare_v2()] or its variants. |
3355 | ** |
3356 | ** ^The second argument is the index of the SQL parameter to be set. |
3357 | ** ^The leftmost SQL parameter has an index of 1. ^When the same named |
3358 | ** SQL parameter is used more than once, second and subsequent |
3359 | ** occurrences have the same index as the first occurrence. |
3360 | ** ^The index for named parameters can be looked up using the |
3361 | ** [sqlite3_bind_parameter_index()] API if desired. ^The index |
3362 | ** for "?NNN" parameters is the value of NNN. |
3363 | ** ^The NNN value must be between 1 and the [sqlite3_limit()] |
3364 | ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). |
3365 | ** |
3366 | ** ^The third argument is the value to bind to the parameter. |
3367 | ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() |
3368 | ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter |
3369 | ** is ignored and the end result is the same as sqlite3_bind_null(). |
3370 | ** |
3371 | ** ^(In those routines that have a fourth argument, its value is the |
3372 | ** number of bytes in the parameter. To be clear: the value is the |
3373 | ** number of <u>bytes</u> in the value, not the number of characters.)^ |
3374 | ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() |
3375 | ** is negative, then the length of the string is |
3376 | ** the number of bytes up to the first zero terminator. |
3377 | ** If the fourth parameter to sqlite3_bind_blob() is negative, then |
3378 | ** the behavior is undefined. |
3379 | ** If a non-negative fourth parameter is provided to sqlite3_bind_text() |
3380 | ** or sqlite3_bind_text16() then that parameter must be the byte offset |
3381 | ** where the NUL terminator would occur assuming the string were NUL |
3382 | ** terminated. If any NUL characters occur at byte offsets less than |
3383 | ** the value of the fourth parameter then the resulting string value will |
3384 | ** contain embedded NULs. The result of expressions involving strings |
3385 | ** with embedded NULs is undefined. |
3386 | ** |
3387 | ** ^The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and |
3388 | ** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or |
3389 | ** string after SQLite has finished with it. ^The destructor is called |
3390 | ** to dispose of the BLOB or string even if the call to sqlite3_bind_blob(), |
3391 | ** sqlite3_bind_text(), or sqlite3_bind_text16() fails. |
3392 | ** ^If the fifth argument is |
3393 | ** the special value [SQLITE_STATIC], then SQLite assumes that the |
3394 | ** information is in static, unmanaged space and does not need to be freed. |
3395 | ** ^If the fifth argument has the value [SQLITE_TRANSIENT], then |
3396 | ** SQLite makes its own private copy of the data immediately, before |
3397 | ** the sqlite3_bind_*() routine returns. |
3398 | ** |
3399 | ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that |
3400 | ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory |
3401 | ** (just an integer to hold its size) while it is being processed. |
3402 | ** Zeroblobs are intended to serve as placeholders for BLOBs whose |
3403 | ** content is later written using |
3404 | ** [sqlite3_blob_open | incremental BLOB I/O] routines. |
3405 | ** ^A negative value for the zeroblob results in a zero-length BLOB. |
3406 | ** |
3407 | ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer |
3408 | ** for the [prepared statement] or with a prepared statement for which |
3409 | ** [sqlite3_step()] has been called more recently than [sqlite3_reset()], |
3410 | ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() |
3411 | ** routine is passed a [prepared statement] that has been finalized, the |
3412 | ** result is undefined and probably harmful. |
3413 | ** |
3414 | ** ^Bindings are not cleared by the [sqlite3_reset()] routine. |
3415 | ** ^Unbound parameters are interpreted as NULL. |
3416 | ** |
3417 | ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an |
3418 | ** [error code] if anything goes wrong. |
3419 | ** ^[SQLITE_RANGE] is returned if the parameter |
3420 | ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. |
3421 | ** |
3422 | ** See also: [sqlite3_bind_parameter_count()], |
3423 | ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. |
3424 | */ |
3425 | SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); |
3426 | SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double); |
3427 | SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int); |
3428 | SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); |
3429 | SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int); |
3430 | SQLITE_API int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*)); |
3431 | SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); |
3432 | SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); |
3433 | SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); |
3434 | |
3435 | /* |
3436 | ** CAPI3REF: Number Of SQL Parameters |
3437 | ** |
3438 | ** ^This routine can be used to find the number of [SQL parameters] |
3439 | ** in a [prepared statement]. SQL parameters are tokens of the |
3440 | ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as |
3441 | ** placeholders for values that are [sqlite3_bind_blob | bound] |
3442 | ** to the parameters at a later time. |
3443 | ** |
3444 | ** ^(This routine actually returns the index of the largest (rightmost) |
3445 | ** parameter. For all forms except ?NNN, this will correspond to the |
3446 | ** number of unique parameters. If parameters of the ?NNN form are used, |
3447 | ** there may be gaps in the list.)^ |
3448 | ** |
3449 | ** See also: [sqlite3_bind_blob|sqlite3_bind()], |
3450 | ** [sqlite3_bind_parameter_name()], and |
3451 | ** [sqlite3_bind_parameter_index()]. |
3452 | */ |
3453 | SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*); |
3454 | |
3455 | /* |
3456 | ** CAPI3REF: Name Of A Host Parameter |
3457 | ** |
3458 | ** ^The sqlite3_bind_parameter_name(P,N) interface returns |
3459 | ** the name of the N-th [SQL parameter] in the [prepared statement] P. |
3460 | ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" |
3461 | ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" |
3462 | ** respectively. |
3463 | ** In other words, the initial ":" or "$" or "@" or "?" |
3464 | ** is included as part of the name.)^ |
3465 | ** ^Parameters of the form "?" without a following integer have no name |
3466 | ** and are referred to as "nameless" or "anonymous parameters". |
3467 | ** |
3468 | ** ^The first host parameter has an index of 1, not 0. |
3469 | ** |
3470 | ** ^If the value N is out of range or if the N-th parameter is |
3471 | ** nameless, then NULL is returned. ^The returned string is |
3472 | ** always in UTF-8 encoding even if the named parameter was |
3473 | ** originally specified as UTF-16 in [sqlite3_prepare16()] or |
3474 | ** [sqlite3_prepare16_v2()]. |
3475 | ** |
3476 | ** See also: [sqlite3_bind_blob|sqlite3_bind()], |
3477 | ** [sqlite3_bind_parameter_count()], and |
3478 | ** [sqlite3_bind_parameter_index()]. |
3479 | */ |
3480 | SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); |
3481 | |
3482 | /* |
3483 | ** CAPI3REF: Index Of A Parameter With A Given Name |
3484 | ** |
3485 | ** ^Return the index of an SQL parameter given its name. ^The |
3486 | ** index value returned is suitable for use as the second |
3487 | ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero |
3488 | ** is returned if no matching parameter is found. ^The parameter |
3489 | ** name must be given in UTF-8 even if the original statement |
3490 | ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. |
3491 | ** |
3492 | ** See also: [sqlite3_bind_blob|sqlite3_bind()], |
3493 | ** [sqlite3_bind_parameter_count()], and |
3494 | ** [sqlite3_bind_parameter_index()]. |
3495 | */ |
3496 | SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); |
3497 | |
3498 | /* |
3499 | ** CAPI3REF: Reset All Bindings On A Prepared Statement |
3500 | ** |
3501 | ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset |
3502 | ** the [sqlite3_bind_blob | bindings] on a [prepared statement]. |
3503 | ** ^Use this routine to reset all host parameters to NULL. |
3504 | */ |
3505 | SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*); |
3506 | |
3507 | /* |
3508 | ** CAPI3REF: Number Of Columns In A Result Set |
3509 | ** |
3510 | ** ^Return the number of columns in the result set returned by the |
3511 | ** [prepared statement]. ^This routine returns 0 if pStmt is an SQL |
3512 | ** statement that does not return data (for example an [UPDATE]). |
3513 | ** |
3514 | ** See also: [sqlite3_data_count()] |
3515 | */ |
3516 | SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt); |
3517 | |
3518 | /* |
3519 | ** CAPI3REF: Column Names In A Result Set |
3520 | ** |
3521 | ** ^These routines return the name assigned to a particular column |
3522 | ** in the result set of a [SELECT] statement. ^The sqlite3_column_name() |
3523 | ** interface returns a pointer to a zero-terminated UTF-8 string |
3524 | ** and sqlite3_column_name16() returns a pointer to a zero-terminated |
3525 | ** UTF-16 string. ^The first parameter is the [prepared statement] |
3526 | ** that implements the [SELECT] statement. ^The second parameter is the |
3527 | ** column number. ^The leftmost column is number 0. |
3528 | ** |
3529 | ** ^The returned string pointer is valid until either the [prepared statement] |
3530 | ** is destroyed by [sqlite3_finalize()] or until the statement is automatically |
3531 | ** reprepared by the first call to [sqlite3_step()] for a particular run |
3532 | ** or until the next call to |
3533 | ** sqlite3_column_name() or sqlite3_column_name16() on the same column. |
3534 | ** |
3535 | ** ^If sqlite3_malloc() fails during the processing of either routine |
3536 | ** (for example during a conversion from UTF-8 to UTF-16) then a |
3537 | ** NULL pointer is returned. |
3538 | ** |
3539 | ** ^The name of a result column is the value of the "AS" clause for |
3540 | ** that column, if there is an AS clause. If there is no AS clause |
3541 | ** then the name of the column is unspecified and may change from |
3542 | ** one release of SQLite to the next. |
3543 | */ |
3544 | SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N); |
3545 | SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N); |
3546 | |
3547 | /* |
3548 | ** CAPI3REF: Source Of Data In A Query Result |
3549 | ** |
3550 | ** ^These routines provide a means to determine the database, table, and |
3551 | ** table column that is the origin of a particular result column in |
3552 | ** [SELECT] statement. |
3553 | ** ^The name of the database or table or column can be returned as |
3554 | ** either a UTF-8 or UTF-16 string. ^The _database_ routines return |
3555 | ** the database name, the _table_ routines return the table name, and |
3556 | ** the origin_ routines return the column name. |
3557 | ** ^The returned string is valid until the [prepared statement] is destroyed |
3558 | ** using [sqlite3_finalize()] or until the statement is automatically |
3559 | ** reprepared by the first call to [sqlite3_step()] for a particular run |
3560 | ** or until the same information is requested |
3561 | ** again in a different encoding. |
3562 | ** |
3563 | ** ^The names returned are the original un-aliased names of the |
3564 | ** database, table, and column. |
3565 | ** |
3566 | ** ^The first argument to these interfaces is a [prepared statement]. |
3567 | ** ^These functions return information about the Nth result column returned by |
3568 | ** the statement, where N is the second function argument. |
3569 | ** ^The left-most column is column 0 for these routines. |
3570 | ** |
3571 | ** ^If the Nth column returned by the statement is an expression or |
3572 | ** subquery and is not a column value, then all of these functions return |
3573 | ** NULL. ^These routine might also return NULL if a memory allocation error |
3574 | ** occurs. ^Otherwise, they return the name of the attached database, table, |
3575 | ** or column that query result column was extracted from. |
3576 | ** |
3577 | ** ^As with all other SQLite APIs, those whose names end with "16" return |
3578 | ** UTF-16 encoded strings and the other functions return UTF-8. |
3579 | ** |
3580 | ** ^These APIs are only available if the library was compiled with the |
3581 | ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. |
3582 | ** |
3583 | ** If two or more threads call one or more of these routines against the same |
3584 | ** prepared statement and column at the same time then the results are |
3585 | ** undefined. |
3586 | ** |
3587 | ** If two or more threads call one or more |
3588 | ** [sqlite3_column_database_name | column metadata interfaces] |
3589 | ** for the same [prepared statement] and result column |
3590 | ** at the same time then the results are undefined. |
3591 | */ |
3592 | SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int); |
3593 | SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int); |
3594 | SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int); |
3595 | SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int); |
3596 | SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int); |
3597 | SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); |
3598 | |
3599 | /* |
3600 | ** CAPI3REF: Declared Datatype Of A Query Result |
3601 | ** |
3602 | ** ^(The first parameter is a [prepared statement]. |
3603 | ** If this statement is a [SELECT] statement and the Nth column of the |
3604 | ** returned result set of that [SELECT] is a table column (not an |
3605 | ** expression or subquery) then the declared type of the table |
3606 | ** column is returned.)^ ^If the Nth column of the result set is an |
3607 | ** expression or subquery, then a NULL pointer is returned. |
3608 | ** ^The returned string is always UTF-8 encoded. |
3609 | ** |
3610 | ** ^(For example, given the database schema: |
3611 | ** |
3612 | ** CREATE TABLE t1(c1 VARIANT); |
3613 | ** |
3614 | ** and the following statement to be compiled: |
3615 | ** |
3616 | ** SELECT c1 + 1, c1 FROM t1; |
3617 | ** |
3618 | ** this routine would return the string "VARIANT" for the second result |
3619 | ** column (i==1), and a NULL pointer for the first result column (i==0).)^ |
3620 | ** |
3621 | ** ^SQLite uses dynamic run-time typing. ^So just because a column |
3622 | ** is declared to contain a particular type does not mean that the |
3623 | ** data stored in that column is of the declared type. SQLite is |
3624 | ** strongly typed, but the typing is dynamic not static. ^Type |
3625 | ** is associated with individual values, not with the containers |
3626 | ** used to hold those values. |
3627 | */ |
3628 | SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int); |
3629 | SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int); |
3630 | |
3631 | /* |
3632 | ** CAPI3REF: Evaluate An SQL Statement |
3633 | ** |
3634 | ** After a [prepared statement] has been prepared using either |
3635 | ** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy |
3636 | ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function |
3637 | ** must be called one or more times to evaluate the statement. |
3638 | ** |
3639 | ** The details of the behavior of the sqlite3_step() interface depend |
3640 | ** on whether the statement was prepared using the newer "v2" interface |
3641 | ** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy |
3642 | ** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the |
3643 | ** new "v2" interface is recommended for new applications but the legacy |
3644 | ** interface will continue to be supported. |
3645 | ** |
3646 | ** ^In the legacy interface, the return value will be either [SQLITE_BUSY], |
3647 | ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. |
3648 | ** ^With the "v2" interface, any of the other [result codes] or |
3649 | ** [extended result codes] might be returned as well. |
3650 | ** |
3651 | ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the |
3652 | ** database locks it needs to do its job. ^If the statement is a [COMMIT] |
3653 | ** or occurs outside of an explicit transaction, then you can retry the |
3654 | ** statement. If the statement is not a [COMMIT] and occurs within an |
3655 | ** explicit transaction then you should rollback the transaction before |
3656 | ** continuing. |
3657 | ** |
3658 | ** ^[SQLITE_DONE] means that the statement has finished executing |
3659 | ** successfully. sqlite3_step() should not be called again on this virtual |
3660 | ** machine without first calling [sqlite3_reset()] to reset the virtual |
3661 | ** machine back to its initial state. |
3662 | ** |
3663 | ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] |
3664 | ** is returned each time a new row of data is ready for processing by the |
3665 | ** caller. The values may be accessed using the [column access functions]. |
3666 | ** sqlite3_step() is called again to retrieve the next row of data. |
3667 | ** |
3668 | ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint |
3669 | ** violation) has occurred. sqlite3_step() should not be called again on |
3670 | ** the VM. More information may be found by calling [sqlite3_errmsg()]. |
3671 | ** ^With the legacy interface, a more specific error code (for example, |
3672 | ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) |
3673 | ** can be obtained by calling [sqlite3_reset()] on the |
3674 | ** [prepared statement]. ^In the "v2" interface, |
3675 | ** the more specific error code is returned directly by sqlite3_step(). |
3676 | ** |
3677 | ** [SQLITE_MISUSE] means that the this routine was called inappropriately. |
3678 | ** Perhaps it was called on a [prepared statement] that has |
3679 | ** already been [sqlite3_finalize | finalized] or on one that had |
3680 | ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could |
3681 | ** be the case that the same database connection is being used by two or |
3682 | ** more threads at the same moment in time. |
3683 | ** |
3684 | ** For all versions of SQLite up to and including 3.6.23.1, a call to |
3685 | ** [sqlite3_reset()] was required after sqlite3_step() returned anything |
3686 | ** other than [SQLITE_ROW] before any subsequent invocation of |
3687 | ** sqlite3_step(). Failure to reset the prepared statement using |
3688 | ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from |
3689 | ** sqlite3_step(). But after version 3.6.23.1, sqlite3_step() began |
3690 | ** calling [sqlite3_reset()] automatically in this circumstance rather |
3691 | ** than returning [SQLITE_MISUSE]. This is not considered a compatibility |
3692 | ** break because any application that ever receives an SQLITE_MISUSE error |
3693 | ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option |
3694 | ** can be used to restore the legacy behavior. |
3695 | ** |
3696 | ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() |
3697 | ** API always returns a generic error code, [SQLITE_ERROR], following any |
3698 | ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call |
3699 | ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the |
3700 | ** specific [error codes] that better describes the error. |
3701 | ** We admit that this is a goofy design. The problem has been fixed |
3702 | ** with the "v2" interface. If you prepare all of your SQL statements |
3703 | ** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead |
3704 | ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, |
3705 | ** then the more specific [error codes] are returned directly |
3706 | ** by sqlite3_step(). The use of the "v2" interface is recommended. |
3707 | */ |
3708 | SQLITE_API int sqlite3_step(sqlite3_stmt*); |
3709 | |
3710 | /* |
3711 | ** CAPI3REF: Number of columns in a result set |
3712 | ** |
3713 | ** ^The sqlite3_data_count(P) interface returns the number of columns in the |
3714 | ** current row of the result set of [prepared statement] P. |
3715 | ** ^If prepared statement P does not have results ready to return |
3716 | ** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of |
3717 | ** interfaces) then sqlite3_data_count(P) returns 0. |
3718 | ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. |
3719 | ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to |
3720 | ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) |
3721 | ** will return non-zero if previous call to [sqlite3_step](P) returned |
3722 | ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] |
3723 | ** where it always returns zero since each step of that multi-step |
3724 | ** pragma returns 0 columns of data. |
3725 | ** |
3726 | ** See also: [sqlite3_column_count()] |
3727 | */ |
3728 | SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt); |
3729 | |
3730 | /* |
3731 | ** CAPI3REF: Fundamental Datatypes |
3732 | ** KEYWORDS: SQLITE_TEXT |
3733 | ** |
3734 | ** ^(Every value in SQLite has one of five fundamental datatypes: |
3735 | ** |
3736 | ** <ul> |
3737 | ** <li> 64-bit signed integer |
3738 | ** <li> 64-bit IEEE floating point number |
3739 | ** <li> string |
3740 | ** <li> BLOB |
3741 | ** <li> NULL |
3742 | ** </ul>)^ |
3743 | ** |
3744 | ** These constants are codes for each of those types. |
3745 | ** |
3746 | ** Note that the SQLITE_TEXT constant was also used in SQLite version 2 |
3747 | ** for a completely different meaning. Software that links against both |
3748 | ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not |
3749 | ** SQLITE_TEXT. |
3750 | */ |
3751 | #define SQLITE_INTEGER 1 |
3752 | #define SQLITE_FLOAT 2 |
3753 | #define SQLITE_BLOB 4 |
3754 | #define SQLITE_NULL 5 |
3755 | #ifdef SQLITE_TEXT |
3756 | # undef SQLITE_TEXT |
3757 | #else |
3758 | # define SQLITE_TEXT 3 |
3759 | #endif |
3760 | #define SQLITE3_TEXT 3 |
3761 | |
3762 | /* |
3763 | ** CAPI3REF: Result Values From A Query |
3764 | ** KEYWORDS: {column access functions} |
3765 | ** |
3766 | ** These routines form the "result set" interface. |
3767 | ** |
3768 | ** ^These routines return information about a single column of the current |
3769 | ** result row of a query. ^In every case the first argument is a pointer |
3770 | ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] |
3771 | ** that was returned from [sqlite3_prepare_v2()] or one of its variants) |
3772 | ** and the second argument is the index of the column for which information |
3773 | ** should be returned. ^The leftmost column of the result set has the index 0. |
3774 | ** ^The number of columns in the result can be determined using |
3775 | ** [sqlite3_column_count()]. |
3776 | ** |
3777 | ** If the SQL statement does not currently point to a valid row, or if the |
3778 | ** column index is out of range, the result is undefined. |
3779 | ** These routines may only be called when the most recent call to |
3780 | ** [sqlite3_step()] has returned [SQLITE_ROW] and neither |
3781 | ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. |
3782 | ** If any of these routines are called after [sqlite3_reset()] or |
3783 | ** [sqlite3_finalize()] or after [sqlite3_step()] has returned |
3784 | ** something other than [SQLITE_ROW], the results are undefined. |
3785 | ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] |
3786 | ** are called from a different thread while any of these routines |
3787 | ** are pending, then the results are undefined. |
3788 | ** |
3789 | ** ^The sqlite3_column_type() routine returns the |
3790 | ** [SQLITE_INTEGER | datatype code] for the initial data type |
3791 | ** of the result column. ^The returned value is one of [SQLITE_INTEGER], |
3792 | ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value |
3793 | ** returned by sqlite3_column_type() is only meaningful if no type |
3794 | ** conversions have occurred as described below. After a type conversion, |
3795 | ** the value returned by sqlite3_column_type() is undefined. Future |
3796 | ** versions of SQLite may change the behavior of sqlite3_column_type() |
3797 | ** following a type conversion. |
3798 | ** |
3799 | ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() |
3800 | ** routine returns the number of bytes in that BLOB or string. |
3801 | ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts |
3802 | ** the string to UTF-8 and then returns the number of bytes. |
3803 | ** ^If the result is a numeric value then sqlite3_column_bytes() uses |
3804 | ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns |
3805 | ** the number of bytes in that string. |
3806 | ** ^If the result is NULL, then sqlite3_column_bytes() returns zero. |
3807 | ** |
3808 | ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() |
3809 | ** routine returns the number of bytes in that BLOB or string. |
3810 | ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts |
3811 | ** the string to UTF-16 and then returns the number of bytes. |
3812 | ** ^If the result is a numeric value then sqlite3_column_bytes16() uses |
3813 | ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns |
3814 | ** the number of bytes in that string. |
3815 | ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. |
3816 | ** |
3817 | ** ^The values returned by [sqlite3_column_bytes()] and |
3818 | ** [sqlite3_column_bytes16()] do not include the zero terminators at the end |
3819 | ** of the string. ^For clarity: the values returned by |
3820 | ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of |
3821 | ** bytes in the string, not the number of characters. |
3822 | ** |
3823 | ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), |
3824 | ** even empty strings, are always zero-terminated. ^The return |
3825 | ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. |
3826 | ** |
3827 | ** ^The object returned by [sqlite3_column_value()] is an |
3828 | ** [unprotected sqlite3_value] object. An unprotected sqlite3_value object |
3829 | ** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()]. |
3830 | ** If the [unprotected sqlite3_value] object returned by |
3831 | ** [sqlite3_column_value()] is used in any other way, including calls |
3832 | ** to routines like [sqlite3_value_int()], [sqlite3_value_text()], |
3833 | ** or [sqlite3_value_bytes()], then the behavior is undefined. |
3834 | ** |
3835 | ** These routines attempt to convert the value where appropriate. ^For |
3836 | ** example, if the internal representation is FLOAT and a text result |
3837 | ** is requested, [sqlite3_snprintf()] is used internally to perform the |
3838 | ** conversion automatically. ^(The following table details the conversions |
3839 | ** that are applied: |
3840 | ** |
3841 | ** <blockquote> |
3842 | ** <table border="1"> |
3843 | ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion |
3844 | ** |
3845 | ** <tr><td> NULL <td> INTEGER <td> Result is 0 |
3846 | ** <tr><td> NULL <td> FLOAT <td> Result is 0.0 |
3847 | ** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer |
3848 | ** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer |
3849 | ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float |
3850 | ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer |
3851 | ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT |
3852 | ** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER |
3853 | ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float |
3854 | ** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB |
3855 | ** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER |
3856 | ** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL |
3857 | ** <tr><td> TEXT <td> BLOB <td> No change |
3858 | ** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER |
3859 | ** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL |
3860 | ** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed |
3861 | ** </table> |
3862 | ** </blockquote>)^ |
3863 | ** |
3864 | ** The table above makes reference to standard C library functions atoi() |
3865 | ** and atof(). SQLite does not really use these functions. It has its |
3866 | ** own equivalent internal routines. The atoi() and atof() names are |
3867 | ** used in the table for brevity and because they are familiar to most |
3868 | ** C programmers. |
3869 | ** |
3870 | ** Note that when type conversions occur, pointers returned by prior |
3871 | ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or |
3872 | ** sqlite3_column_text16() may be invalidated. |
3873 | ** Type conversions and pointer invalidations might occur |
3874 | ** in the following cases: |
3875 | ** |
3876 | ** <ul> |
3877 | ** <li> The initial content is a BLOB and sqlite3_column_text() or |
3878 | ** sqlite3_column_text16() is called. A zero-terminator might |
3879 | ** need to be added to the string.</li> |
3880 | ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or |
3881 | ** sqlite3_column_text16() is called. The content must be converted |
3882 | ** to UTF-16.</li> |
3883 | ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or |
3884 | ** sqlite3_column_text() is called. The content must be converted |
3885 | ** to UTF-8.</li> |
3886 | ** </ul> |
3887 | ** |
3888 | ** ^Conversions between UTF-16be and UTF-16le are always done in place and do |
3889 | ** not invalidate a prior pointer, though of course the content of the buffer |
3890 | ** that the prior pointer references will have been modified. Other kinds |
3891 | ** of conversion are done in place when it is possible, but sometimes they |
3892 | ** are not possible and in those cases prior pointers are invalidated. |
3893 | ** |
3894 | ** The safest and easiest to remember policy is to invoke these routines |
3895 | ** in one of the following ways: |
3896 | ** |
3897 | ** <ul> |
3898 | ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> |
3899 | ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> |
3900 | ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> |
3901 | ** </ul> |
3902 | ** |
3903 | ** In other words, you should call sqlite3_column_text(), |
3904 | ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result |
3905 | ** into the desired format, then invoke sqlite3_column_bytes() or |
3906 | ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls |
3907 | ** to sqlite3_column_text() or sqlite3_column_blob() with calls to |
3908 | ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() |
3909 | ** with calls to sqlite3_column_bytes(). |
3910 | ** |
3911 | ** ^The pointers returned are valid until a type conversion occurs as |
3912 | ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or |
3913 | ** [sqlite3_finalize()] is called. ^The memory space used to hold strings |
3914 | ** and BLOBs is freed automatically. Do <b>not</b> pass the pointers returned |
3915 | ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into |
3916 | ** [sqlite3_free()]. |
3917 | ** |
3918 | ** ^(If a memory allocation error occurs during the evaluation of any |
3919 | ** of these routines, a default value is returned. The default value |
3920 | ** is either the integer 0, the floating point number 0.0, or a NULL |
3921 | ** pointer. Subsequent calls to [sqlite3_errcode()] will return |
3922 | ** [SQLITE_NOMEM].)^ |
3923 | */ |
3924 | SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); |
3925 | SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol); |
3926 | SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); |
3927 | SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol); |
3928 | SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol); |
3929 | SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); |
3930 | SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); |
3931 | SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); |
3932 | SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); |
3933 | SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); |
3934 | |
3935 | /* |
3936 | ** CAPI3REF: Destroy A Prepared Statement Object |
3937 | ** |
3938 | ** ^The sqlite3_finalize() function is called to delete a [prepared statement]. |
3939 | ** ^If the most recent evaluation of the statement encountered no errors |
3940 | ** or if the statement is never been evaluated, then sqlite3_finalize() returns |
3941 | ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then |
3942 | ** sqlite3_finalize(S) returns the appropriate [error code] or |
3943 | ** [extended error code]. |
3944 | ** |
3945 | ** ^The sqlite3_finalize(S) routine can be called at any point during |
3946 | ** the life cycle of [prepared statement] S: |
3947 | ** before statement S is ever evaluated, after |
3948 | ** one or more calls to [sqlite3_reset()], or after any call |
3949 | ** to [sqlite3_step()] regardless of whether or not the statement has |
3950 | ** completed execution. |
3951 | ** |
3952 | ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. |
3953 | ** |
3954 | ** The application must finalize every [prepared statement] in order to avoid |
3955 | ** resource leaks. It is a grievous error for the application to try to use |
3956 | ** a prepared statement after it has been finalized. Any use of a prepared |
3957 | ** statement after it has been finalized can result in undefined and |
3958 | ** undesirable behavior such as segfaults and heap corruption. |
3959 | */ |
3960 | SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt); |
3961 | |
3962 | /* |
3963 | ** CAPI3REF: Reset A Prepared Statement Object |
3964 | ** |
3965 | ** The sqlite3_reset() function is called to reset a [prepared statement] |
3966 | ** object back to its initial state, ready to be re-executed. |
3967 | ** ^Any SQL statement variables that had values bound to them using |
3968 | ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. |
3969 | ** Use [sqlite3_clear_bindings()] to reset the bindings. |
3970 | ** |
3971 | ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S |
3972 | ** back to the beginning of its program. |
3973 | ** |
3974 | ** ^If the most recent call to [sqlite3_step(S)] for the |
3975 | ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], |
3976 | ** or if [sqlite3_step(S)] has never before been called on S, |
3977 | ** then [sqlite3_reset(S)] returns [SQLITE_OK]. |
3978 | ** |
3979 | ** ^If the most recent call to [sqlite3_step(S)] for the |
3980 | ** [prepared statement] S indicated an error, then |
3981 | ** [sqlite3_reset(S)] returns an appropriate [error code]. |
3982 | ** |
3983 | ** ^The [sqlite3_reset(S)] interface does not change the values |
3984 | ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. |
3985 | */ |
3986 | SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt); |
3987 | |
3988 | /* |
3989 | ** CAPI3REF: Create Or Redefine SQL Functions |
3990 | ** KEYWORDS: {function creation routines} |
3991 | ** KEYWORDS: {application-defined SQL function} |
3992 | ** KEYWORDS: {application-defined SQL functions} |
3993 | ** |
3994 | ** ^These functions (collectively known as "function creation routines") |
3995 | ** are used to add SQL functions or aggregates or to redefine the behavior |
3996 | ** of existing SQL functions or aggregates. The only differences between |
3997 | ** these routines are the text encoding expected for |
3998 | ** the second parameter (the name of the function being created) |
3999 | ** and the presence or absence of a destructor callback for |
4000 | ** the application data pointer. |
4001 | ** |
4002 | ** ^The first parameter is the [database connection] to which the SQL |
4003 | ** function is to be added. ^If an application uses more than one database |
4004 | ** connection then application-defined SQL functions must be added |
4005 | ** to each database connection separately. |
4006 | ** |
4007 | ** ^The second parameter is the name of the SQL function to be created or |
4008 | ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 |
4009 | ** representation, exclusive of the zero-terminator. ^Note that the name |
4010 | ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. |
4011 | ** ^Any attempt to create a function with a longer name |
4012 | ** will result in [SQLITE_MISUSE] being returned. |
4013 | ** |
4014 | ** ^The third parameter (nArg) |
4015 | ** is the number of arguments that the SQL function or |
4016 | ** aggregate takes. ^If this parameter is -1, then the SQL function or |
4017 | ** aggregate may take any number of arguments between 0 and the limit |
4018 | ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third |
4019 | ** parameter is less than -1 or greater than 127 then the behavior is |
4020 | ** undefined. |
4021 | ** |
4022 | ** ^The fourth parameter, eTextRep, specifies what |
4023 | ** [SQLITE_UTF8 | text encoding] this SQL function prefers for |
4024 | ** its parameters. The application should set this parameter to |
4025 | ** [SQLITE_UTF16LE] if the function implementation invokes |
4026 | ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the |
4027 | ** implementation invokes [sqlite3_value_text16be()] on an input, or |
4028 | ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] |
4029 | ** otherwise. ^The same SQL function may be registered multiple times using |
4030 | ** different preferred text encodings, with different implementations for |
4031 | ** each encoding. |
4032 | ** ^When multiple implementations of the same function are available, SQLite |
4033 | ** will pick the one that involves the least amount of data conversion. |
4034 | ** |
4035 | ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] |
4036 | ** to signal that the function will always return the same result given |
4037 | ** the same inputs within a single SQL statement. Most SQL functions are |
4038 | ** deterministic. The built-in [random()] SQL function is an example of a |
4039 | ** function that is not deterministic. The SQLite query planner is able to |
4040 | ** perform additional optimizations on deterministic functions, so use |
4041 | ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. |
4042 | ** |
4043 | ** ^(The fifth parameter is an arbitrary pointer. The implementation of the |
4044 | ** function can gain access to this pointer using [sqlite3_user_data()].)^ |
4045 | ** |
4046 | ** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are |
4047 | ** pointers to C-language functions that implement the SQL function or |
4048 | ** aggregate. ^A scalar SQL function requires an implementation of the xFunc |
4049 | ** callback only; NULL pointers must be passed as the xStep and xFinal |
4050 | ** parameters. ^An aggregate SQL function requires an implementation of xStep |
4051 | ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing |
4052 | ** SQL function or aggregate, pass NULL pointers for all three function |
4053 | ** callbacks. |
4054 | ** |
4055 | ** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL, |
4056 | ** then it is destructor for the application data pointer. |
4057 | ** The destructor is invoked when the function is deleted, either by being |
4058 | ** overloaded or when the database connection closes.)^ |
4059 | ** ^The destructor is also invoked if the call to |
4060 | ** sqlite3_create_function_v2() fails. |
4061 | ** ^When the destructor callback of the tenth parameter is invoked, it |
4062 | ** is passed a single argument which is a copy of the application data |
4063 | ** pointer which was the fifth parameter to sqlite3_create_function_v2(). |
4064 | ** |
4065 | ** ^It is permitted to register multiple implementations of the same |
4066 | ** functions with the same name but with either differing numbers of |
4067 | ** arguments or differing preferred text encodings. ^SQLite will use |
4068 | ** the implementation that most closely matches the way in which the |
4069 | ** SQL function is used. ^A function implementation with a non-negative |
4070 | ** nArg parameter is a better match than a function implementation with |
4071 | ** a negative nArg. ^A function where the preferred text encoding |
4072 | ** matches the database encoding is a better |
4073 | ** match than a function where the encoding is different. |
4074 | ** ^A function where the encoding difference is between UTF16le and UTF16be |
4075 | ** is a closer match than a function where the encoding difference is |
4076 | ** between UTF8 and UTF16. |
4077 | ** |
4078 | ** ^Built-in functions may be overloaded by new application-defined functions. |
4079 | ** |
4080 | ** ^An application-defined function is permitted to call other |
4081 | ** SQLite interfaces. However, such calls must not |
4082 | ** close the database connection nor finalize or reset the prepared |
4083 | ** statement in which the function is running. |
4084 | */ |
4085 | SQLITE_API int sqlite3_create_function( |
4086 | sqlite3 *db, |
4087 | const char *zFunctionName, |
4088 | int nArg, |
4089 | int eTextRep, |
4090 | void *pApp, |
4091 | void (*xFunc)(sqlite3_context*,int,sqlite3_value**), |
4092 | void (*xStep)(sqlite3_context*,int,sqlite3_value**), |
4093 | void (*xFinal)(sqlite3_context*) |
4094 | ); |
4095 | SQLITE_API int sqlite3_create_function16( |
4096 | sqlite3 *db, |
4097 | const void *zFunctionName, |
4098 | int nArg, |
4099 | int eTextRep, |
4100 | void *pApp, |
4101 | void (*xFunc)(sqlite3_context*,int,sqlite3_value**), |
4102 | void (*xStep)(sqlite3_context*,int,sqlite3_value**), |
4103 | void (*xFinal)(sqlite3_context*) |
4104 | ); |
4105 | SQLITE_API int sqlite3_create_function_v2( |
4106 | sqlite3 *db, |
4107 | const char *zFunctionName, |
4108 | int nArg, |
4109 | int eTextRep, |
4110 | void *pApp, |
4111 | void (*xFunc)(sqlite3_context*,int,sqlite3_value**), |
4112 | void (*xStep)(sqlite3_context*,int,sqlite3_value**), |
4113 | void (*xFinal)(sqlite3_context*), |
4114 | void(*xDestroy)(void*) |
4115 | ); |
4116 | |
4117 | /* |
4118 | ** CAPI3REF: Text Encodings |
4119 | ** |
4120 | ** These constant define integer codes that represent the various |
4121 | ** text encodings supported by SQLite. |
4122 | */ |
4123 | #define SQLITE_UTF8 1 |
4124 | #define SQLITE_UTF16LE 2 |
4125 | #define SQLITE_UTF16BE 3 |
4126 | #define SQLITE_UTF16 4 /* Use native byte order */ |
4127 | #define SQLITE_ANY 5 /* Deprecated */ |
4128 | #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ |
4129 | |
4130 | /* |
4131 | ** CAPI3REF: Function Flags |
4132 | ** |
4133 | ** These constants may be ORed together with the |
4134 | ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument |
4135 | ** to [sqlite3_create_function()], [sqlite3_create_function16()], or |
4136 | ** [sqlite3_create_function_v2()]. |
4137 | */ |
4138 | #define SQLITE_DETERMINISTIC 0x800 |
4139 | |
4140 | /* |
4141 | ** CAPI3REF: Deprecated Functions |
4142 | ** DEPRECATED |
4143 | ** |
4144 | ** These functions are [deprecated]. In order to maintain |
4145 | ** backwards compatibility with older code, these functions continue |
4146 | ** to be supported. However, new applications should avoid |
4147 | ** the use of these functions. To help encourage people to avoid |
4148 | ** using these functions, we are not going to tell you what they do. |
4149 | */ |
4150 | #ifndef SQLITE_OMIT_DEPRECATED |
4151 | SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); |
4152 | SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); |
4153 | SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); |
4154 | SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void); |
4155 | SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); |
4156 | SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), |
4157 | void*,sqlite3_int64); |
4158 | #endif |
4159 | |
4160 | /* |
4161 | ** CAPI3REF: Obtaining SQL Function Parameter Values |
4162 | ** |
4163 | ** The C-language implementation of SQL functions and aggregates uses |
4164 | ** this set of interface routines to access the parameter values on |
4165 | ** the function or aggregate. |
4166 | ** |
4167 | ** The xFunc (for scalar functions) or xStep (for aggregates) parameters |
4168 | ** to [sqlite3_create_function()] and [sqlite3_create_function16()] |
4169 | ** define callbacks that implement the SQL functions and aggregates. |
4170 | ** The 3rd parameter to these callbacks is an array of pointers to |
4171 | ** [protected sqlite3_value] objects. There is one [sqlite3_value] object for |
4172 | ** each parameter to the SQL function. These routines are used to |
4173 | ** extract values from the [sqlite3_value] objects. |
4174 | ** |
4175 | ** These routines work only with [protected sqlite3_value] objects. |
4176 | ** Any attempt to use these routines on an [unprotected sqlite3_value] |
4177 | ** object results in undefined behavior. |
4178 | ** |
4179 | ** ^These routines work just like the corresponding [column access functions] |
4180 | ** except that these routines take a single [protected sqlite3_value] object |
4181 | ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. |
4182 | ** |
4183 | ** ^The sqlite3_value_text16() interface extracts a UTF-16 string |
4184 | ** in the native byte-order of the host machine. ^The |
4185 | ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces |
4186 | ** extract UTF-16 strings as big-endian and little-endian respectively. |
4187 | ** |
4188 | ** ^(The sqlite3_value_numeric_type() interface attempts to apply |
4189 | ** numeric affinity to the value. This means that an attempt is |
4190 | ** made to convert the value to an integer or floating point. If |
4191 | ** such a conversion is possible without loss of information (in other |
4192 | ** words, if the value is a string that looks like a number) |
4193 | ** then the conversion is performed. Otherwise no conversion occurs. |
4194 | ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ |
4195 | ** |
4196 | ** Please pay particular attention to the fact that the pointer returned |
4197 | ** from [sqlite3_value_blob()], [sqlite3_value_text()], or |
4198 | ** [sqlite3_value_text16()] can be invalidated by a subsequent call to |
4199 | ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], |
4200 | ** or [sqlite3_value_text16()]. |
4201 | ** |
4202 | ** These routines must be called from the same thread as |
4203 | ** the SQL function that supplied the [sqlite3_value*] parameters. |
4204 | */ |
4205 | SQLITE_API const void *sqlite3_value_blob(sqlite3_value*); |
4206 | SQLITE_API int sqlite3_value_bytes(sqlite3_value*); |
4207 | SQLITE_API int sqlite3_value_bytes16(sqlite3_value*); |
4208 | SQLITE_API double sqlite3_value_double(sqlite3_value*); |
4209 | SQLITE_API int sqlite3_value_int(sqlite3_value*); |
4210 | SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*); |
4211 | SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*); |
4212 | SQLITE_API const void *sqlite3_value_text16(sqlite3_value*); |
4213 | SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*); |
4214 | SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*); |
4215 | SQLITE_API int sqlite3_value_type(sqlite3_value*); |
4216 | SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*); |
4217 | |
4218 | /* |
4219 | ** CAPI3REF: Obtain Aggregate Function Context |
4220 | ** |
4221 | ** Implementations of aggregate SQL functions use this |
4222 | ** routine to allocate memory for storing their state. |
4223 | ** |
4224 | ** ^The first time the sqlite3_aggregate_context(C,N) routine is called |
4225 | ** for a particular aggregate function, SQLite |
4226 | ** allocates N of memory, zeroes out that memory, and returns a pointer |
4227 | ** to the new memory. ^On second and subsequent calls to |
4228 | ** sqlite3_aggregate_context() for the same aggregate function instance, |
4229 | ** the same buffer is returned. Sqlite3_aggregate_context() is normally |
4230 | ** called once for each invocation of the xStep callback and then one |
4231 | ** last time when the xFinal callback is invoked. ^(When no rows match |
4232 | ** an aggregate query, the xStep() callback of the aggregate function |
4233 | ** implementation is never called and xFinal() is called exactly once. |
4234 | ** In those cases, sqlite3_aggregate_context() might be called for the |
4235 | ** first time from within xFinal().)^ |
4236 | ** |
4237 | ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer |
4238 | ** when first called if N is less than or equal to zero or if a memory |
4239 | ** allocate error occurs. |
4240 | ** |
4241 | ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is |
4242 | ** determined by the N parameter on first successful call. Changing the |
4243 | ** value of N in subsequent call to sqlite3_aggregate_context() within |
4244 | ** the same aggregate function instance will not resize the memory |
4245 | ** allocation.)^ Within the xFinal callback, it is customary to set |
4246 | ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no |
4247 | ** pointless memory allocations occur. |
4248 | ** |
4249 | ** ^SQLite automatically frees the memory allocated by |
4250 | ** sqlite3_aggregate_context() when the aggregate query concludes. |
4251 | ** |
4252 | ** The first parameter must be a copy of the |
4253 | ** [sqlite3_context | SQL function context] that is the first parameter |
4254 | ** to the xStep or xFinal callback routine that implements the aggregate |
4255 | ** function. |
4256 | ** |
4257 | ** This routine must be called from the same thread in which |
4258 | ** the aggregate SQL function is running. |
4259 | */ |
4260 | SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); |
4261 | |
4262 | /* |
4263 | ** CAPI3REF: User Data For Functions |
4264 | ** |
4265 | ** ^The sqlite3_user_data() interface returns a copy of |
4266 | ** the pointer that was the pUserData parameter (the 5th parameter) |
4267 | ** of the [sqlite3_create_function()] |
4268 | ** and [sqlite3_create_function16()] routines that originally |
4269 | ** registered the application defined function. |
4270 | ** |
4271 | ** This routine must be called from the same thread in which |
4272 | ** the application-defined function is running. |
4273 | */ |
4274 | SQLITE_API void *sqlite3_user_data(sqlite3_context*); |
4275 | |
4276 | /* |
4277 | ** CAPI3REF: Database Connection For Functions |
4278 | ** |
4279 | ** ^The sqlite3_context_db_handle() interface returns a copy of |
4280 | ** the pointer to the [database connection] (the 1st parameter) |
4281 | ** of the [sqlite3_create_function()] |
4282 | ** and [sqlite3_create_function16()] routines that originally |
4283 | ** registered the application defined function. |
4284 | */ |
4285 | SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); |
4286 | |
4287 | /* |
4288 | ** CAPI3REF: Function Auxiliary Data |
4289 | ** |
4290 | ** These functions may be used by (non-aggregate) SQL functions to |
4291 | ** associate metadata with argument values. If the same value is passed to |
4292 | ** multiple invocations of the same SQL function during query execution, under |
4293 | ** some circumstances the associated metadata may be preserved. An example |
4294 | ** of where this might be useful is in a regular-expression matching |
4295 | ** function. The compiled version of the regular expression can be stored as |
4296 | ** metadata associated with the pattern string. |
4297 | ** Then as long as the pattern string remains the same, |
4298 | ** the compiled regular expression can be reused on multiple |
4299 | ** invocations of the same function. |
4300 | ** |
4301 | ** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata |
4302 | ** associated by the sqlite3_set_auxdata() function with the Nth argument |
4303 | ** value to the application-defined function. ^If there is no metadata |
4304 | ** associated with the function argument, this sqlite3_get_auxdata() interface |
4305 | ** returns a NULL pointer. |
4306 | ** |
4307 | ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th |
4308 | ** argument of the application-defined function. ^Subsequent |
4309 | ** calls to sqlite3_get_auxdata(C,N) return P from the most recent |
4310 | ** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or |
4311 | ** NULL if the metadata has been discarded. |
4312 | ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, |
4313 | ** SQLite will invoke the destructor function X with parameter P exactly |
4314 | ** once, when the metadata is discarded. |
4315 | ** SQLite is free to discard the metadata at any time, including: <ul> |
4316 | ** <li> when the corresponding function parameter changes, or |
4317 | ** <li> when [sqlite3_reset()] or [sqlite3_finalize()] is called for the |
4318 | ** SQL statement, or |
4319 | ** <li> when sqlite3_set_auxdata() is invoked again on the same parameter, or |
4320 | ** <li> during the original sqlite3_set_auxdata() call when a memory |
4321 | ** allocation error occurs. </ul>)^ |
4322 | ** |
4323 | ** Note the last bullet in particular. The destructor X in |
4324 | ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the |
4325 | ** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() |
4326 | ** should be called near the end of the function implementation and the |
4327 | ** function implementation should not make any use of P after |
4328 | ** sqlite3_set_auxdata() has been called. |
4329 | ** |
4330 | ** ^(In practice, metadata is preserved between function calls for |
4331 | ** function parameters that are compile-time constants, including literal |
4332 | ** values and [parameters] and expressions composed from the same.)^ |
4333 | ** |
4334 | ** These routines must be called from the same thread in which |
4335 | ** the SQL function is running. |
4336 | */ |
4337 | SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N); |
4338 | SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); |
4339 | |
4340 | |
4341 | /* |
4342 | ** CAPI3REF: Constants Defining Special Destructor Behavior |
4343 | ** |
4344 | ** These are special values for the destructor that is passed in as the |
4345 | ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor |
4346 | ** argument is SQLITE_STATIC, it means that the content pointer is constant |
4347 | ** and will never change. It does not need to be destroyed. ^The |
4348 | ** SQLITE_TRANSIENT value means that the content will likely change in |
4349 | ** the near future and that SQLite should make its own private copy of |
4350 | ** the content before returning. |
4351 | ** |
4352 | ** The typedef is necessary to work around problems in certain |
4353 | ** C++ compilers. |
4354 | */ |
4355 | typedef void (*sqlite3_destructor_type)(void*); |
4356 | #define SQLITE_STATIC ((sqlite3_destructor_type)0) |
4357 | #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) |
4358 | |
4359 | /* |
4360 | ** CAPI3REF: Setting The Result Of An SQL Function |
4361 | ** |
4362 | ** These routines are used by the xFunc or xFinal callbacks that |
4363 | ** implement SQL functions and aggregates. See |
4364 | ** [sqlite3_create_function()] and [sqlite3_create_function16()] |
4365 | ** for additional information. |
4366 | ** |
4367 | ** These functions work very much like the [parameter binding] family of |
4368 | ** functions used to bind values to host parameters in prepared statements. |
4369 | ** Refer to the [SQL parameter] documentation for additional information. |
4370 | ** |
4371 | ** ^The sqlite3_result_blob() interface sets the result from |
4372 | ** an application-defined function to be the BLOB whose content is pointed |
4373 | ** to by the second parameter and which is N bytes long where N is the |
4374 | ** third parameter. |
4375 | ** |
4376 | ** ^The sqlite3_result_zeroblob() interfaces set the result of |
4377 | ** the application-defined function to be a BLOB containing all zero |
4378 | ** bytes and N bytes in size, where N is the value of the 2nd parameter. |
4379 | ** |
4380 | ** ^The sqlite3_result_double() interface sets the result from |
4381 | ** an application-defined function to be a floating point value specified |
4382 | ** by its 2nd argument. |
4383 | ** |
4384 | ** ^The sqlite3_result_error() and sqlite3_result_error16() functions |
4385 | ** cause the implemented SQL function to throw an exception. |
4386 | ** ^SQLite uses the string pointed to by the |
4387 | ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() |
4388 | ** as the text of an error message. ^SQLite interprets the error |
4389 | ** message string from sqlite3_result_error() as UTF-8. ^SQLite |
4390 | ** interprets the string from sqlite3_result_error16() as UTF-16 in native |
4391 | ** byte order. ^If the third parameter to sqlite3_result_error() |
4392 | ** or sqlite3_result_error16() is negative then SQLite takes as the error |
4393 | ** message all text up through the first zero character. |
4394 | ** ^If the third parameter to sqlite3_result_error() or |
4395 | ** sqlite3_result_error16() is non-negative then SQLite takes that many |
4396 | ** bytes (not characters) from the 2nd parameter as the error message. |
4397 | ** ^The sqlite3_result_error() and sqlite3_result_error16() |
4398 | ** routines make a private copy of the error message text before |
4399 | ** they return. Hence, the calling function can deallocate or |
4400 | ** modify the text after they return without harm. |
4401 | ** ^The sqlite3_result_error_code() function changes the error code |
4402 | ** returned by SQLite as a result of an error in a function. ^By default, |
4403 | ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() |
4404 | ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. |
4405 | ** |
4406 | ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an |
4407 | ** error indicating that a string or BLOB is too long to represent. |
4408 | ** |
4409 | ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an |
4410 | ** error indicating that a memory allocation failed. |
4411 | ** |
4412 | ** ^The sqlite3_result_int() interface sets the return value |
4413 | ** of the application-defined function to be the 32-bit signed integer |
4414 | ** value given in the 2nd argument. |
4415 | ** ^The sqlite3_result_int64() interface sets the return value |
4416 | ** of the application-defined function to be the 64-bit signed integer |
4417 | ** value given in the 2nd argument. |
4418 | ** |
4419 | ** ^The sqlite3_result_null() interface sets the return value |
4420 | ** of the application-defined function to be NULL. |
4421 | ** |
4422 | ** ^The sqlite3_result_text(), sqlite3_result_text16(), |
4423 | ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces |
4424 | ** set the return value of the application-defined function to be |
4425 | ** a text string which is represented as UTF-8, UTF-16 native byte order, |
4426 | ** UTF-16 little endian, or UTF-16 big endian, respectively. |
4427 | ** ^SQLite takes the text result from the application from |
4428 | ** the 2nd parameter of the sqlite3_result_text* interfaces. |
4429 | ** ^If the 3rd parameter to the sqlite3_result_text* interfaces |
4430 | ** is negative, then SQLite takes result text from the 2nd parameter |
4431 | ** through the first zero character. |
4432 | ** ^If the 3rd parameter to the sqlite3_result_text* interfaces |
4433 | ** is non-negative, then as many bytes (not characters) of the text |
4434 | ** pointed to by the 2nd parameter are taken as the application-defined |
4435 | ** function result. If the 3rd parameter is non-negative, then it |
4436 | ** must be the byte offset into the string where the NUL terminator would |
4437 | ** appear if the string where NUL terminated. If any NUL characters occur |
4438 | ** in the string at a byte offset that is less than the value of the 3rd |
4439 | ** parameter, then the resulting string will contain embedded NULs and the |
4440 | ** result of expressions operating on strings with embedded NULs is undefined. |
4441 | ** ^If the 4th parameter to the sqlite3_result_text* interfaces |
4442 | ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that |
4443 | ** function as the destructor on the text or BLOB result when it has |
4444 | ** finished using that result. |
4445 | ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to |
4446 | ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite |
4447 | ** assumes that the text or BLOB result is in constant space and does not |
4448 | ** copy the content of the parameter nor call a destructor on the content |
4449 | ** when it has finished using that result. |
4450 | ** ^If the 4th parameter to the sqlite3_result_text* interfaces |
4451 | ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT |
4452 | ** then SQLite makes a copy of the result into space obtained from |
4453 | ** from [sqlite3_malloc()] before it returns. |
4454 | ** |
4455 | ** ^The sqlite3_result_value() interface sets the result of |
4456 | ** the application-defined function to be a copy the |
4457 | ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The |
4458 | ** sqlite3_result_value() interface makes a copy of the [sqlite3_value] |
4459 | ** so that the [sqlite3_value] specified in the parameter may change or |
4460 | ** be deallocated after sqlite3_result_value() returns without harm. |
4461 | ** ^A [protected sqlite3_value] object may always be used where an |
4462 | ** [unprotected sqlite3_value] object is required, so either |
4463 | ** kind of [sqlite3_value] object can be used with this interface. |
4464 | ** |
4465 | ** If these routines are called from within the different thread |
4466 | ** than the one containing the application-defined function that received |
4467 | ** the [sqlite3_context] pointer, the results are undefined. |
4468 | */ |
4469 | SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); |
4470 | SQLITE_API void sqlite3_result_double(sqlite3_context*, double); |
4471 | SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int); |
4472 | SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int); |
4473 | SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*); |
4474 | SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*); |
4475 | SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int); |
4476 | SQLITE_API void sqlite3_result_int(sqlite3_context*, int); |
4477 | SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); |
4478 | SQLITE_API void sqlite3_result_null(sqlite3_context*); |
4479 | SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); |
4480 | SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); |
4481 | SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); |
4482 | SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); |
4483 | SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*); |
4484 | SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n); |
4485 | |
4486 | /* |
4487 | ** CAPI3REF: Define New Collating Sequences |
4488 | ** |
4489 | ** ^These functions add, remove, or modify a [collation] associated |
4490 | ** with the [database connection] specified as the first argument. |
4491 | ** |
4492 | ** ^The name of the collation is a UTF-8 string |
4493 | ** for sqlite3_create_collation() and sqlite3_create_collation_v2() |
4494 | ** and a UTF-16 string in native byte order for sqlite3_create_collation16(). |
4495 | ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are |
4496 | ** considered to be the same name. |
4497 | ** |
4498 | ** ^(The third argument (eTextRep) must be one of the constants: |
4499 | ** <ul> |
4500 | ** <li> [SQLITE_UTF8], |
4501 | ** <li> [SQLITE_UTF16LE], |
4502 | ** <li> [SQLITE_UTF16BE], |
4503 | ** <li> [SQLITE_UTF16], or |
4504 | ** <li> [SQLITE_UTF16_ALIGNED]. |
4505 | ** </ul>)^ |
4506 | ** ^The eTextRep argument determines the encoding of strings passed |
4507 | ** to the collating function callback, xCallback. |
4508 | ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep |
4509 | ** force strings to be UTF16 with native byte order. |
4510 | ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin |
4511 | ** on an even byte address. |
4512 | ** |
4513 | ** ^The fourth argument, pArg, is an application data pointer that is passed |
4514 | ** through as the first argument to the collating function callback. |
4515 | ** |
4516 | ** ^The fifth argument, xCallback, is a pointer to the collating function. |
4517 | ** ^Multiple collating functions can be registered using the same name but |
4518 | ** with different eTextRep parameters and SQLite will use whichever |
4519 | ** function requires the least amount of data transformation. |
4520 | ** ^If the xCallback argument is NULL then the collating function is |
4521 | ** deleted. ^When all collating functions having the same name are deleted, |
4522 | ** that collation is no longer usable. |
4523 | ** |
4524 | ** ^The collating function callback is invoked with a copy of the pArg |
4525 | ** application data pointer and with two strings in the encoding specified |
4526 | ** by the eTextRep argument. The collating function must return an |
4527 | ** integer that is negative, zero, or positive |
4528 | ** if the first string is less than, equal to, or greater than the second, |
4529 | ** respectively. A collating function must always return the same answer |
4530 | ** given the same inputs. If two or more collating functions are registered |
4531 | ** to the same collation name (using different eTextRep values) then all |
4532 | ** must give an equivalent answer when invoked with equivalent strings. |
4533 | ** The collating function must obey the following properties for all |
4534 | ** strings A, B, and C: |
4535 | ** |
4536 | ** <ol> |
4537 | ** <li> If A==B then B==A. |
4538 | ** <li> If A==B and B==C then A==C. |
4539 | ** <li> If A<B THEN B>A. |
4540 | ** <li> If A<B and B<C then A<C. |
4541 | ** </ol> |
4542 | ** |
4543 | ** If a collating function fails any of the above constraints and that |
4544 | ** collating function is registered and used, then the behavior of SQLite |
4545 | ** is undefined. |
4546 | ** |
4547 | ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() |
4548 | ** with the addition that the xDestroy callback is invoked on pArg when |
4549 | ** the collating function is deleted. |
4550 | ** ^Collating functions are deleted when they are overridden by later |
4551 | ** calls to the collation creation functions or when the |
4552 | ** [database connection] is closed using [sqlite3_close()]. |
4553 | ** |
4554 | ** ^The xDestroy callback is <u>not</u> called if the |
4555 | ** sqlite3_create_collation_v2() function fails. Applications that invoke |
4556 | ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should |
4557 | ** check the return code and dispose of the application data pointer |
4558 | ** themselves rather than expecting SQLite to deal with it for them. |
4559 | ** This is different from every other SQLite interface. The inconsistency |
4560 | ** is unfortunate but cannot be changed without breaking backwards |
4561 | ** compatibility. |
4562 | ** |
4563 | ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. |
4564 | */ |
4565 | SQLITE_API int sqlite3_create_collation( |
4566 | sqlite3*, |
4567 | const char *zName, |
4568 | int eTextRep, |
4569 | void *pArg, |
4570 | int(*xCompare)(void*,int,const void*,int,const void*) |
4571 | ); |
4572 | SQLITE_API int sqlite3_create_collation_v2( |
4573 | sqlite3*, |
4574 | const char *zName, |
4575 | int eTextRep, |
4576 | void *pArg, |
4577 | int(*xCompare)(void*,int,const void*,int,const void*), |
4578 | void(*xDestroy)(void*) |
4579 | ); |
4580 | SQLITE_API int sqlite3_create_collation16( |
4581 | sqlite3*, |
4582 | const void *zName, |
4583 | int eTextRep, |
4584 | void *pArg, |
4585 | int(*xCompare)(void*,int,const void*,int,const void*) |
4586 | ); |
4587 | |
4588 | /* |
4589 | ** CAPI3REF: Collation Needed Callbacks |
4590 | ** |
4591 | ** ^To avoid having to register all collation sequences before a database |
4592 | ** can be used, a single callback function may be registered with the |
4593 | ** [database connection] to be invoked whenever an undefined collation |
4594 | ** sequence is required. |
4595 | ** |
4596 | ** ^If the function is registered using the sqlite3_collation_needed() API, |
4597 | ** then it is passed the names of undefined collation sequences as strings |
4598 | ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, |
4599 | ** the names are passed as UTF-16 in machine native byte order. |
4600 | ** ^A call to either function replaces the existing collation-needed callback. |
4601 | ** |
4602 | ** ^(When the callback is invoked, the first argument passed is a copy |
4603 | ** of the second argument to sqlite3_collation_needed() or |
4604 | ** sqlite3_collation_needed16(). The second argument is the database |
4605 | ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], |
4606 | ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation |
4607 | ** sequence function required. The fourth parameter is the name of the |
4608 | ** required collation sequence.)^ |
4609 | ** |
4610 | ** The callback function should register the desired collation using |
4611 | ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or |
4612 | ** [sqlite3_create_collation_v2()]. |
4613 | */ |
4614 | SQLITE_API int sqlite3_collation_needed( |
4615 | sqlite3*, |
4616 | void*, |
4617 | void(*)(void*,sqlite3*,int eTextRep,const char*) |
4618 | ); |
4619 | SQLITE_API int sqlite3_collation_needed16( |
4620 | sqlite3*, |
4621 | void*, |
4622 | void(*)(void*,sqlite3*,int eTextRep,const void*) |
4623 | ); |
4624 | |
4625 | #ifdef SQLITE_HAS_CODEC |
4626 | /* |
4627 | ** Specify the key for an encrypted database. This routine should be |
4628 | ** called right after sqlite3_open(). |
4629 | ** |
4630 | ** The code to implement this API is not available in the public release |
4631 | ** of SQLite. |
4632 | */ |
4633 | SQLITE_API int sqlite3_key( |
4634 | sqlite3 *db, /* Database to be rekeyed */ |
4635 | const void *pKey, int nKey /* The key */ |
4636 | ); |
4637 | SQLITE_API int sqlite3_key_v2( |
4638 | sqlite3 *db, /* Database to be rekeyed */ |
4639 | const char *zDbName, /* Name of the database */ |
4640 | const void *pKey, int nKey /* The key */ |
4641 | ); |
4642 | |
4643 | /* |
4644 | ** Change the key on an open database. If the current database is not |
4645 | ** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the |
4646 | ** database is decrypted. |
4647 | ** |
4648 | ** The code to implement this API is not available in the public release |
4649 | ** of SQLite. |
4650 | */ |
4651 | SQLITE_API int sqlite3_rekey( |
4652 | sqlite3 *db, /* Database to be rekeyed */ |
4653 | const void *pKey, int nKey /* The new key */ |
4654 | ); |
4655 | SQLITE_API int sqlite3_rekey_v2( |
4656 | sqlite3 *db, /* Database to be rekeyed */ |
4657 | const char *zDbName, /* Name of the database */ |
4658 | const void *pKey, int nKey /* The new key */ |
4659 | ); |
4660 | |
4661 | /* |
4662 | ** Specify the activation key for a SEE database. Unless |
4663 | ** activated, none of the SEE routines will work. |
4664 | */ |
4665 | SQLITE_API void sqlite3_activate_see( |
4666 | const char *zPassPhrase /* Activation phrase */ |
4667 | ); |
4668 | #endif |
4669 | |
4670 | #ifdef SQLITE_ENABLE_CEROD |
4671 | /* |
4672 | ** Specify the activation key for a CEROD database. Unless |
4673 | ** activated, none of the CEROD routines will work. |
4674 | */ |
4675 | SQLITE_API void sqlite3_activate_cerod( |
4676 | const char *zPassPhrase /* Activation phrase */ |
4677 | ); |
4678 | #endif |
4679 | |
4680 | /* |
4681 | ** CAPI3REF: Suspend Execution For A Short Time |
4682 | ** |
4683 | ** The sqlite3_sleep() function causes the current thread to suspend execution |
4684 | ** for at least a number of milliseconds specified in its parameter. |
4685 | ** |
4686 | ** If the operating system does not support sleep requests with |
4687 | ** millisecond time resolution, then the time will be rounded up to |
4688 | ** the nearest second. The number of milliseconds of sleep actually |
4689 | ** requested from the operating system is returned. |
4690 | ** |
4691 | ** ^SQLite implements this interface by calling the xSleep() |
4692 | ** method of the default [sqlite3_vfs] object. If the xSleep() method |
4693 | ** of the default VFS is not implemented correctly, or not implemented at |
4694 | ** all, then the behavior of sqlite3_sleep() may deviate from the description |
4695 | ** in the previous paragraphs. |
4696 | */ |
4697 | SQLITE_API int sqlite3_sleep(int); |
4698 | |
4699 | /* |
4700 | ** CAPI3REF: Name Of The Folder Holding Temporary Files |
4701 | ** |
4702 | ** ^(If this global variable is made to point to a string which is |
4703 | ** the name of a folder (a.k.a. directory), then all temporary files |
4704 | ** created by SQLite when using a built-in [sqlite3_vfs | VFS] |
4705 | ** will be placed in that directory.)^ ^If this variable |
4706 | ** is a NULL pointer, then SQLite performs a search for an appropriate |
4707 | ** temporary file directory. |
4708 | ** |
4709 | ** It is not safe to read or modify this variable in more than one |
4710 | ** thread at a time. It is not safe to read or modify this variable |
4711 | ** if a [database connection] is being used at the same time in a separate |
4712 | ** thread. |
4713 | ** It is intended that this variable be set once |
4714 | ** as part of process initialization and before any SQLite interface |
4715 | ** routines have been called and that this variable remain unchanged |
4716 | ** thereafter. |
4717 | ** |
4718 | ** ^The [temp_store_directory pragma] may modify this variable and cause |
4719 | ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, |
4720 | ** the [temp_store_directory pragma] always assumes that any string |
4721 | ** that this variable points to is held in memory obtained from |
4722 | ** [sqlite3_malloc] and the pragma may attempt to free that memory |
4723 | ** using [sqlite3_free]. |
4724 | ** Hence, if this variable is modified directly, either it should be |
4725 | ** made NULL or made to point to memory obtained from [sqlite3_malloc] |
4726 | ** or else the use of the [temp_store_directory pragma] should be avoided. |
4727 | ** |
4728 | ** <b>Note to Windows Runtime users:</b> The temporary directory must be set |
4729 | ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various |
4730 | ** features that require the use of temporary files may fail. Here is an |
4731 | ** example of how to do this using C++ with the Windows Runtime: |
4732 | ** |
4733 | ** <blockquote><pre> |
4734 | ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> |
4735 | ** TemporaryFolder->Path->Data(); |
4736 | ** char zPathBuf[MAX_PATH + 1]; |
4737 | ** memset(zPathBuf, 0, sizeof(zPathBuf)); |
4738 | ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), |
4739 | ** NULL, NULL); |
4740 | ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); |
4741 | ** </pre></blockquote> |
4742 | */ |
4743 | SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; |
4744 | |
4745 | /* |
4746 | ** CAPI3REF: Name Of The Folder Holding Database Files |
4747 | ** |
4748 | ** ^(If this global variable is made to point to a string which is |
4749 | ** the name of a folder (a.k.a. directory), then all database files |
4750 | ** specified with a relative pathname and created or accessed by |
4751 | ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed |
4752 | ** to be relative to that directory.)^ ^If this variable is a NULL |
4753 | ** pointer, then SQLite assumes that all database files specified |
4754 | ** with a relative pathname are relative to the current directory |
4755 | ** for the process. Only the windows VFS makes use of this global |
4756 | ** variable; it is ignored by the unix VFS. |
4757 | ** |
4758 | ** Changing the value of this variable while a database connection is |
4759 | ** open can result in a corrupt database. |
4760 | ** |
4761 | ** It is not safe to read or modify this variable in more than one |
4762 | ** thread at a time. It is not safe to read or modify this variable |
4763 | ** if a [database connection] is being used at the same time in a separate |
4764 | ** thread. |
4765 | ** It is intended that this variable be set once |
4766 | ** as part of process initialization and before any SQLite interface |
4767 | ** routines have been called and that this variable remain unchanged |
4768 | ** thereafter. |
4769 | ** |
4770 | ** ^The [data_store_directory pragma] may modify this variable and cause |
4771 | ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, |
4772 | ** the [data_store_directory pragma] always assumes that any string |
4773 | ** that this variable points to is held in memory obtained from |
4774 | ** [sqlite3_malloc] and the pragma may attempt to free that memory |
4775 | ** using [sqlite3_free]. |
4776 | ** Hence, if this variable is modified directly, either it should be |
4777 | ** made NULL or made to point to memory obtained from [sqlite3_malloc] |
4778 | ** or else the use of the [data_store_directory pragma] should be avoided. |
4779 | */ |
4780 | SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory; |
4781 | |
4782 | /* |
4783 | ** CAPI3REF: Test For Auto-Commit Mode |
4784 | ** KEYWORDS: {autocommit mode} |
4785 | ** |
4786 | ** ^The sqlite3_get_autocommit() interface returns non-zero or |
4787 | ** zero if the given database connection is or is not in autocommit mode, |
4788 | ** respectively. ^Autocommit mode is on by default. |
4789 | ** ^Autocommit mode is disabled by a [BEGIN] statement. |
4790 | ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. |
4791 | ** |
4792 | ** If certain kinds of errors occur on a statement within a multi-statement |
4793 | ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], |
4794 | ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the |
4795 | ** transaction might be rolled back automatically. The only way to |
4796 | ** find out whether SQLite automatically rolled back the transaction after |
4797 | ** an error is to use this function. |
4798 | ** |
4799 | ** If another thread changes the autocommit status of the database |
4800 | ** connection while this routine is running, then the return value |
4801 | ** is undefined. |
4802 | */ |
4803 | SQLITE_API int sqlite3_get_autocommit(sqlite3*); |
4804 | |
4805 | /* |
4806 | ** CAPI3REF: Find The Database Handle Of A Prepared Statement |
4807 | ** |
4808 | ** ^The sqlite3_db_handle interface returns the [database connection] handle |
4809 | ** to which a [prepared statement] belongs. ^The [database connection] |
4810 | ** returned by sqlite3_db_handle is the same [database connection] |
4811 | ** that was the first argument |
4812 | ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to |
4813 | ** create the statement in the first place. |
4814 | */ |
4815 | SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*); |
4816 | |
4817 | /* |
4818 | ** CAPI3REF: Return The Filename For A Database Connection |
4819 | ** |
4820 | ** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename |
4821 | ** associated with database N of connection D. ^The main database file |
4822 | ** has the name "main". If there is no attached database N on the database |
4823 | ** connection D, or if database N is a temporary or in-memory database, then |
4824 | ** a NULL pointer is returned. |
4825 | ** |
4826 | ** ^The filename returned by this function is the output of the |
4827 | ** xFullPathname method of the [VFS]. ^In other words, the filename |
4828 | ** will be an absolute pathname, even if the filename used |
4829 | ** to open the database originally was a URI or relative pathname. |
4830 | */ |
4831 | SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); |
4832 | |
4833 | /* |
4834 | ** CAPI3REF: Determine if a database is read-only |
4835 | ** |
4836 | ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N |
4837 | ** of connection D is read-only, 0 if it is read/write, or -1 if N is not |
4838 | ** the name of a database on connection D. |
4839 | */ |
4840 | SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); |
4841 | |
4842 | /* |
4843 | ** CAPI3REF: Find the next prepared statement |
4844 | ** |
4845 | ** ^This interface returns a pointer to the next [prepared statement] after |
4846 | ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL |
4847 | ** then this interface returns a pointer to the first prepared statement |
4848 | ** associated with the database connection pDb. ^If no prepared statement |
4849 | ** satisfies the conditions of this routine, it returns NULL. |
4850 | ** |
4851 | ** The [database connection] pointer D in a call to |
4852 | ** [sqlite3_next_stmt(D,S)] must refer to an open database |
4853 | ** connection and in particular must not be a NULL pointer. |
4854 | */ |
4855 | SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); |
4856 | |
4857 | /* |
4858 | ** CAPI3REF: Commit And Rollback Notification Callbacks |
4859 | ** |
4860 | ** ^The sqlite3_commit_hook() interface registers a callback |
4861 | ** function to be invoked whenever a transaction is [COMMIT | committed]. |
4862 | ** ^Any callback set by a previous call to sqlite3_commit_hook() |
4863 | ** for the same database connection is overridden. |
4864 | ** ^The sqlite3_rollback_hook() interface registers a callback |
4865 | ** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. |
4866 | ** ^Any callback set by a previous call to sqlite3_rollback_hook() |
4867 | ** for the same database connection is overridden. |
4868 | ** ^The pArg argument is passed through to the callback. |
4869 | ** ^If the callback on a commit hook function returns non-zero, |
4870 | ** then the commit is converted into a rollback. |
4871 | ** |
4872 | ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions |
4873 | ** return the P argument from the previous call of the same function |
4874 | ** on the same [database connection] D, or NULL for |
4875 | ** the first call for each function on D. |
4876 | ** |
4877 | ** The commit and rollback hook callbacks are not reentrant. |
4878 | ** The callback implementation must not do anything that will modify |
4879 | ** the database connection that invoked the callback. Any actions |
4880 | ** to modify the database connection must be deferred until after the |
4881 | ** completion of the [sqlite3_step()] call that triggered the commit |
4882 | ** or rollback hook in the first place. |
4883 | ** Note that running any other SQL statements, including SELECT statements, |
4884 | ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify |
4885 | ** the database connections for the meaning of "modify" in this paragraph. |
4886 | ** |
4887 | ** ^Registering a NULL function disables the callback. |
4888 | ** |
4889 | ** ^When the commit hook callback routine returns zero, the [COMMIT] |
4890 | ** operation is allowed to continue normally. ^If the commit hook |
4891 | ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. |
4892 | ** ^The rollback hook is invoked on a rollback that results from a commit |
4893 | ** hook returning non-zero, just as it would be with any other rollback. |
4894 | ** |
4895 | ** ^For the purposes of this API, a transaction is said to have been |
4896 | ** rolled back if an explicit "ROLLBACK" statement is executed, or |
4897 | ** an error or constraint causes an implicit rollback to occur. |
4898 | ** ^The rollback callback is not invoked if a transaction is |
4899 | ** automatically rolled back because the database connection is closed. |
4900 | ** |
4901 | ** See also the [sqlite3_update_hook()] interface. |
4902 | */ |
4903 | SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); |
4904 | SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); |
4905 | |
4906 | /* |
4907 | ** CAPI3REF: Data Change Notification Callbacks |
4908 | ** |
4909 | ** ^The sqlite3_update_hook() interface registers a callback function |
4910 | ** with the [database connection] identified by the first argument |
4911 | ** to be invoked whenever a row is updated, inserted or deleted in |
4912 | ** a rowid table. |
4913 | ** ^Any callback set by a previous call to this function |
4914 | ** for the same database connection is overridden. |
4915 | ** |
4916 | ** ^The second argument is a pointer to the function to invoke when a |
4917 | ** row is updated, inserted or deleted in a rowid table. |
4918 | ** ^The first argument to the callback is a copy of the third argument |
4919 | ** to sqlite3_update_hook(). |
4920 | ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], |
4921 | ** or [SQLITE_UPDATE], depending on the operation that caused the callback |
4922 | ** to be invoked. |
4923 | ** ^The third and fourth arguments to the callback contain pointers to the |
4924 | ** database and table name containing the affected row. |
4925 | ** ^The final callback parameter is the [rowid] of the row. |
4926 | ** ^In the case of an update, this is the [rowid] after the update takes place. |
4927 | ** |
4928 | ** ^(The update hook is not invoked when internal system tables are |
4929 | ** modified (i.e. sqlite_master and sqlite_sequence).)^ |
4930 | ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. |
4931 | ** |
4932 | ** ^In the current implementation, the update hook |
4933 | ** is not invoked when duplication rows are deleted because of an |
4934 | ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook |
4935 | ** invoked when rows are deleted using the [truncate optimization]. |
4936 | ** The exceptions defined in this paragraph might change in a future |
4937 | ** release of SQLite. |
4938 | ** |
4939 | ** The update hook implementation must not do anything that will modify |
4940 | ** the database connection that invoked the update hook. Any actions |
4941 | ** to modify the database connection must be deferred until after the |
4942 | ** completion of the [sqlite3_step()] call that triggered the update hook. |
4943 | ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their |
4944 | ** database connections for the meaning of "modify" in this paragraph. |
4945 | ** |
4946 | ** ^The sqlite3_update_hook(D,C,P) function |
4947 | ** returns the P argument from the previous call |
4948 | ** on the same [database connection] D, or NULL for |
4949 | ** the first call on D. |
4950 | ** |
4951 | ** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()] |
4952 | ** interfaces. |
4953 | */ |
4954 | SQLITE_API void *sqlite3_update_hook( |
4955 | sqlite3*, |
4956 | void(*)(void *,int ,char const *,char const *,sqlite3_int64), |
4957 | void* |
4958 | ); |
4959 | |
4960 | /* |
4961 | ** CAPI3REF: Enable Or Disable Shared Pager Cache |
4962 | ** |
4963 | ** ^(This routine enables or disables the sharing of the database cache |
4964 | ** and schema data structures between [database connection | connections] |
4965 | ** to the same database. Sharing is enabled if the argument is true |
4966 | ** and disabled if the argument is false.)^ |
4967 | ** |
4968 | ** ^Cache sharing is enabled and disabled for an entire process. |
4969 | ** This is a change as of SQLite version 3.5.0. In prior versions of SQLite, |
4970 | ** sharing was enabled or disabled for each thread separately. |
4971 | ** |
4972 | ** ^(The cache sharing mode set by this interface effects all subsequent |
4973 | ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. |
4974 | ** Existing database connections continue use the sharing mode |
4975 | ** that was in effect at the time they were opened.)^ |
4976 | ** |
4977 | ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled |
4978 | ** successfully. An [error code] is returned otherwise.)^ |
4979 | ** |
4980 | ** ^Shared cache is disabled by default. But this might change in |
4981 | ** future releases of SQLite. Applications that care about shared |
4982 | ** cache setting should set it explicitly. |
4983 | ** |
4984 | ** This interface is threadsafe on processors where writing a |
4985 | ** 32-bit integer is atomic. |
4986 | ** |
4987 | ** See Also: [SQLite Shared-Cache Mode] |
4988 | */ |
4989 | SQLITE_API int sqlite3_enable_shared_cache(int); |
4990 | |
4991 | /* |
4992 | ** CAPI3REF: Attempt To Free Heap Memory |
4993 | ** |
4994 | ** ^The sqlite3_release_memory() interface attempts to free N bytes |
4995 | ** of heap memory by deallocating non-essential memory allocations |
4996 | ** held by the database library. Memory used to cache database |
4997 | ** pages to improve performance is an example of non-essential memory. |
4998 | ** ^sqlite3_release_memory() returns the number of bytes actually freed, |
4999 | ** which might be more or less than the amount requested. |
5000 | ** ^The sqlite3_release_memory() routine is a no-op returning zero |
5001 | ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. |
5002 | ** |
5003 | ** See also: [sqlite3_db_release_memory()] |
5004 | */ |
5005 | SQLITE_API int sqlite3_release_memory(int); |
5006 | |
5007 | /* |
5008 | ** CAPI3REF: Free Memory Used By A Database Connection |
5009 | ** |
5010 | ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap |
5011 | ** memory as possible from database connection D. Unlike the |
5012 | ** [sqlite3_release_memory()] interface, this interface is in effect even |
5013 | ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is |
5014 | ** omitted. |
5015 | ** |
5016 | ** See also: [sqlite3_release_memory()] |
5017 | */ |
5018 | SQLITE_API int sqlite3_db_release_memory(sqlite3*); |
5019 | |
5020 | /* |
5021 | ** CAPI3REF: Impose A Limit On Heap Size |
5022 | ** |
5023 | ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the |
5024 | ** soft limit on the amount of heap memory that may be allocated by SQLite. |
5025 | ** ^SQLite strives to keep heap memory utilization below the soft heap |
5026 | ** limit by reducing the number of pages held in the page cache |
5027 | ** as heap memory usages approaches the limit. |
5028 | ** ^The soft heap limit is "soft" because even though SQLite strives to stay |
5029 | ** below the limit, it will exceed the limit rather than generate |
5030 | ** an [SQLITE_NOMEM] error. In other words, the soft heap limit |
5031 | ** is advisory only. |
5032 | ** |
5033 | ** ^The return value from sqlite3_soft_heap_limit64() is the size of |
5034 | ** the soft heap limit prior to the call, or negative in the case of an |
5035 | ** error. ^If the argument N is negative |
5036 | ** then no change is made to the soft heap limit. Hence, the current |
5037 | ** size of the soft heap limit can be determined by invoking |
5038 | ** sqlite3_soft_heap_limit64() with a negative argument. |
5039 | ** |
5040 | ** ^If the argument N is zero then the soft heap limit is disabled. |
5041 | ** |
5042 | ** ^(The soft heap limit is not enforced in the current implementation |
5043 | ** if one or more of following conditions are true: |
5044 | ** |
5045 | ** <ul> |
5046 | ** <li> The soft heap limit is set to zero. |
5047 | ** <li> Memory accounting is disabled using a combination of the |
5048 | ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and |
5049 | ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. |
5050 | ** <li> An alternative page cache implementation is specified using |
5051 | ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). |
5052 | ** <li> The page cache allocates from its own memory pool supplied |
5053 | ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than |
5054 | ** from the heap. |
5055 | ** </ul>)^ |
5056 | ** |
5057 | ** Beginning with SQLite version 3.7.3, the soft heap limit is enforced |
5058 | ** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] |
5059 | ** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], |
5060 | ** the soft heap limit is enforced on every memory allocation. Without |
5061 | ** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced |
5062 | ** when memory is allocated by the page cache. Testing suggests that because |
5063 | ** the page cache is the predominate memory user in SQLite, most |
5064 | ** applications will achieve adequate soft heap limit enforcement without |
5065 | ** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. |
5066 | ** |
5067 | ** The circumstances under which SQLite will enforce the soft heap limit may |
5068 | ** changes in future releases of SQLite. |
5069 | */ |
5070 | SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); |
5071 | |
5072 | /* |
5073 | ** CAPI3REF: Deprecated Soft Heap Limit Interface |
5074 | ** DEPRECATED |
5075 | ** |
5076 | ** This is a deprecated version of the [sqlite3_soft_heap_limit64()] |
5077 | ** interface. This routine is provided for historical compatibility |
5078 | ** only. All new applications should use the |
5079 | ** [sqlite3_soft_heap_limit64()] interface rather than this one. |
5080 | */ |
5081 | SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); |
5082 | |
5083 | |
5084 | /* |
5085 | ** CAPI3REF: Extract Metadata About A Column Of A Table |
5086 | ** |
5087 | ** ^This routine returns metadata about a specific column of a specific |
5088 | ** database table accessible using the [database connection] handle |
5089 | ** passed as the first function argument. |
5090 | ** |
5091 | ** ^The column is identified by the second, third and fourth parameters to |
5092 | ** this function. ^The second parameter is either the name of the database |
5093 | ** (i.e. "main", "temp", or an attached database) containing the specified |
5094 | ** table or NULL. ^If it is NULL, then all attached databases are searched |
5095 | ** for the table using the same algorithm used by the database engine to |
5096 | ** resolve unqualified table references. |
5097 | ** |
5098 | ** ^The third and fourth parameters to this function are the table and column |
5099 | ** name of the desired column, respectively. Neither of these parameters |
5100 | ** may be NULL. |
5101 | ** |
5102 | ** ^Metadata is returned by writing to the memory locations passed as the 5th |
5103 | ** and subsequent parameters to this function. ^Any of these arguments may be |
5104 | ** NULL, in which case the corresponding element of metadata is omitted. |
5105 | ** |
5106 | ** ^(<blockquote> |
5107 | ** <table border="1"> |
5108 | ** <tr><th> Parameter <th> Output<br>Type <th> Description |
5109 | ** |
5110 | ** <tr><td> 5th <td> const char* <td> Data type |
5111 | ** <tr><td> 6th <td> const char* <td> Name of default collation sequence |
5112 | ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint |
5113 | ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY |
5114 | ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] |
5115 | ** </table> |
5116 | ** </blockquote>)^ |
5117 | ** |
5118 | ** ^The memory pointed to by the character pointers returned for the |
5119 | ** declaration type and collation sequence is valid only until the next |
5120 | ** call to any SQLite API function. |
5121 | ** |
5122 | ** ^If the specified table is actually a view, an [error code] is returned. |
5123 | ** |
5124 | ** ^If the specified column is "rowid", "oid" or "_rowid_" and an |
5125 | ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output |
5126 | ** parameters are set for the explicitly declared column. ^(If there is no |
5127 | ** explicitly declared [INTEGER PRIMARY KEY] column, then the output |
5128 | ** parameters are set as follows: |
5129 | ** |
5130 | ** <pre> |
5131 | ** data type: "INTEGER" |
5132 | ** collation sequence: "BINARY" |
5133 | ** not null: 0 |
5134 | ** primary key: 1 |
5135 | ** auto increment: 0 |
5136 | ** </pre>)^ |
5137 | ** |
5138 | ** ^(This function may load one or more schemas from database files. If an |
5139 | ** error occurs during this process, or if the requested table or column |
5140 | ** cannot be found, an [error code] is returned and an error message left |
5141 | ** in the [database connection] (to be retrieved using sqlite3_errmsg()).)^ |
5142 | ** |
5143 | ** ^This API is only available if the library was compiled with the |
5144 | ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined. |
5145 | */ |
5146 | SQLITE_API int sqlite3_table_column_metadata( |
5147 | sqlite3 *db, /* Connection handle */ |
5148 | const char *zDbName, /* Database name or NULL */ |
5149 | const char *zTableName, /* Table name */ |
5150 | const char *zColumnName, /* Column name */ |
5151 | char const **pzDataType, /* OUTPUT: Declared data type */ |
5152 | char const **pzCollSeq, /* OUTPUT: Collation sequence name */ |
5153 | int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ |
5154 | int *pPrimaryKey, /* OUTPUT: True if column part of PK */ |
5155 | int *pAutoinc /* OUTPUT: True if column is auto-increment */ |
5156 | ); |
5157 | |
5158 | /* |
5159 | ** CAPI3REF: Load An Extension |
5160 | ** |
5161 | ** ^This interface loads an SQLite extension library from the named file. |
5162 | ** |
5163 | ** ^The sqlite3_load_extension() interface attempts to load an |
5164 | ** [SQLite extension] library contained in the file zFile. If |
5165 | ** the file cannot be loaded directly, attempts are made to load |
5166 | ** with various operating-system specific extensions added. |
5167 | ** So for example, if "samplelib" cannot be loaded, then names like |
5168 | ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might |
5169 | ** be tried also. |
5170 | ** |
5171 | ** ^The entry point is zProc. |
5172 | ** ^(zProc may be 0, in which case SQLite will try to come up with an |
5173 | ** entry point name on its own. It first tries "sqlite3_extension_init". |
5174 | ** If that does not work, it constructs a name "sqlite3_X_init" where the |
5175 | ** X is consists of the lower-case equivalent of all ASCII alphabetic |
5176 | ** characters in the filename from the last "/" to the first following |
5177 | ** "." and omitting any initial "lib".)^ |
5178 | ** ^The sqlite3_load_extension() interface returns |
5179 | ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. |
5180 | ** ^If an error occurs and pzErrMsg is not 0, then the |
5181 | ** [sqlite3_load_extension()] interface shall attempt to |
5182 | ** fill *pzErrMsg with error message text stored in memory |
5183 | ** obtained from [sqlite3_malloc()]. The calling function |
5184 | ** should free this memory by calling [sqlite3_free()]. |
5185 | ** |
5186 | ** ^Extension loading must be enabled using |
5187 | ** [sqlite3_enable_load_extension()] prior to calling this API, |
5188 | ** otherwise an error will be returned. |
5189 | ** |
5190 | ** See also the [load_extension() SQL function]. |
5191 | */ |
5192 | SQLITE_API int sqlite3_load_extension( |
5193 | sqlite3 *db, /* Load the extension into this database connection */ |
5194 | const char *zFile, /* Name of the shared library containing extension */ |
5195 | const char *zProc, /* Entry point. Derived from zFile if 0 */ |
5196 | char **pzErrMsg /* Put error message here if not 0 */ |
5197 | ); |
5198 | |
5199 | /* |
5200 | ** CAPI3REF: Enable Or Disable Extension Loading |
5201 | ** |
5202 | ** ^So as not to open security holes in older applications that are |
5203 | ** unprepared to deal with [extension loading], and as a means of disabling |
5204 | ** [extension loading] while evaluating user-entered SQL, the following API |
5205 | ** is provided to turn the [sqlite3_load_extension()] mechanism on and off. |
5206 | ** |
5207 | ** ^Extension loading is off by default. |
5208 | ** ^Call the sqlite3_enable_load_extension() routine with onoff==1 |
5209 | ** to turn extension loading on and call it with onoff==0 to turn |
5210 | ** it back off again. |
5211 | */ |
5212 | SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff); |
5213 | |
5214 | /* |
5215 | ** CAPI3REF: Automatically Load Statically Linked Extensions |
5216 | ** |
5217 | ** ^This interface causes the xEntryPoint() function to be invoked for |
5218 | ** each new [database connection] that is created. The idea here is that |
5219 | ** xEntryPoint() is the entry point for a statically linked [SQLite extension] |
5220 | ** that is to be automatically loaded into all new database connections. |
5221 | ** |
5222 | ** ^(Even though the function prototype shows that xEntryPoint() takes |
5223 | ** no arguments and returns void, SQLite invokes xEntryPoint() with three |
5224 | ** arguments and expects and integer result as if the signature of the |
5225 | ** entry point where as follows: |
5226 | ** |
5227 | ** <blockquote><pre> |
5228 | ** int xEntryPoint( |
5229 | ** sqlite3 *db, |
5230 | ** const char **pzErrMsg, |
5231 | ** const struct sqlite3_api_routines *pThunk |
5232 | ** ); |
5233 | ** </pre></blockquote>)^ |
5234 | ** |
5235 | ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg |
5236 | ** point to an appropriate error message (obtained from [sqlite3_mprintf()]) |
5237 | ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg |
5238 | ** is NULL before calling the xEntryPoint(). ^SQLite will invoke |
5239 | ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any |
5240 | ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], |
5241 | ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. |
5242 | ** |
5243 | ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already |
5244 | ** on the list of automatic extensions is a harmless no-op. ^No entry point |
5245 | ** will be called more than once for each database connection that is opened. |
5246 | ** |
5247 | ** See also: [sqlite3_reset_auto_extension()] |
5248 | ** and [sqlite3_cancel_auto_extension()] |
5249 | */ |
5250 | SQLITE_API int sqlite3_auto_extension(void (*xEntryPoint)(void)); |
5251 | |
5252 | /* |
5253 | ** CAPI3REF: Cancel Automatic Extension Loading |
5254 | ** |
5255 | ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the |
5256 | ** initialization routine X that was registered using a prior call to |
5257 | ** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] |
5258 | ** routine returns 1 if initialization routine X was successfully |
5259 | ** unregistered and it returns 0 if X was not on the list of initialization |
5260 | ** routines. |
5261 | */ |
5262 | SQLITE_API int sqlite3_cancel_auto_extension(void (*xEntryPoint)(void)); |
5263 | |
5264 | /* |
5265 | ** CAPI3REF: Reset Automatic Extension Loading |
5266 | ** |
5267 | ** ^This interface disables all automatic extensions previously |
5268 | ** registered using [sqlite3_auto_extension()]. |
5269 | */ |
5270 | SQLITE_API void sqlite3_reset_auto_extension(void); |
5271 | |
5272 | /* |
5273 | ** The interface to the virtual-table mechanism is currently considered |
5274 | ** to be experimental. The interface might change in incompatible ways. |
5275 | ** If this is a problem for you, do not use the interface at this time. |
5276 | ** |
5277 | ** When the virtual-table mechanism stabilizes, we will declare the |
5278 | ** interface fixed, support it indefinitely, and remove this comment. |
5279 | */ |
5280 | |
5281 | /* |
5282 | ** Structures used by the virtual table interface |
5283 | */ |
5284 | typedef struct sqlite3_vtab sqlite3_vtab; |
5285 | typedef struct sqlite3_index_info sqlite3_index_info; |
5286 | typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; |
5287 | typedef struct sqlite3_module sqlite3_module; |
5288 | |
5289 | /* |
5290 | ** CAPI3REF: Virtual Table Object |
5291 | ** KEYWORDS: sqlite3_module {virtual table module} |
5292 | ** |
5293 | ** This structure, sometimes called a "virtual table module", |
5294 | ** defines the implementation of a [virtual tables]. |
5295 | ** This structure consists mostly of methods for the module. |
5296 | ** |
5297 | ** ^A virtual table module is created by filling in a persistent |
5298 | ** instance of this structure and passing a pointer to that instance |
5299 | ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. |
5300 | ** ^The registration remains valid until it is replaced by a different |
5301 | ** module or until the [database connection] closes. The content |
5302 | ** of this structure must not change while it is registered with |
5303 | ** any database connection. |
5304 | */ |
5305 | struct sqlite3_module { |
5306 | int iVersion; |
5307 | int (*xCreate)(sqlite3*, void *pAux, |
5308 | int argc, const char *const*argv, |
5309 | sqlite3_vtab **ppVTab, char**); |
5310 | int (*xConnect)(sqlite3*, void *pAux, |
5311 | int argc, const char *const*argv, |
5312 | sqlite3_vtab **ppVTab, char**); |
5313 | int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); |
5314 | int (*xDisconnect)(sqlite3_vtab *pVTab); |
5315 | int (*xDestroy)(sqlite3_vtab *pVTab); |
5316 | int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); |
5317 | int (*xClose)(sqlite3_vtab_cursor*); |
5318 | int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, |
5319 | int argc, sqlite3_value **argv); |
5320 | int (*xNext)(sqlite3_vtab_cursor*); |
5321 | int (*xEof)(sqlite3_vtab_cursor*); |
5322 | int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); |
5323 | int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); |
5324 | int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); |
5325 | int (*xBegin)(sqlite3_vtab *pVTab); |
5326 | int (*xSync)(sqlite3_vtab *pVTab); |
5327 | int (*xCommit)(sqlite3_vtab *pVTab); |
5328 | int (*xRollback)(sqlite3_vtab *pVTab); |
5329 | int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, |
5330 | void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), |
5331 | void **ppArg); |
5332 | int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); |
5333 | /* The methods above are in version 1 of the sqlite_module object. Those |
5334 | ** below are for version 2 and greater. */ |
5335 | int (*xSavepoint)(sqlite3_vtab *pVTab, int); |
5336 | int (*xRelease)(sqlite3_vtab *pVTab, int); |
5337 | int (*xRollbackTo)(sqlite3_vtab *pVTab, int); |
5338 | }; |
5339 | |
5340 | /* |
5341 | ** CAPI3REF: Virtual Table Indexing Information |
5342 | ** KEYWORDS: sqlite3_index_info |
5343 | ** |
5344 | ** The sqlite3_index_info structure and its substructures is used as part |
5345 | ** of the [virtual table] interface to |
5346 | ** pass information into and receive the reply from the [xBestIndex] |
5347 | ** method of a [virtual table module]. The fields under **Inputs** are the |
5348 | ** inputs to xBestIndex and are read-only. xBestIndex inserts its |
5349 | ** results into the **Outputs** fields. |
5350 | ** |
5351 | ** ^(The aConstraint[] array records WHERE clause constraints of the form: |
5352 | ** |
5353 | ** <blockquote>column OP expr</blockquote> |
5354 | ** |
5355 | ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is |
5356 | ** stored in aConstraint[].op using one of the |
5357 | ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ |
5358 | ** ^(The index of the column is stored in |
5359 | ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the |
5360 | ** expr on the right-hand side can be evaluated (and thus the constraint |
5361 | ** is usable) and false if it cannot.)^ |
5362 | ** |
5363 | ** ^The optimizer automatically inverts terms of the form "expr OP column" |
5364 | ** and makes other simplifications to the WHERE clause in an attempt to |
5365 | ** get as many WHERE clause terms into the form shown above as possible. |
5366 | ** ^The aConstraint[] array only reports WHERE clause terms that are |
5367 | ** relevant to the particular virtual table being queried. |
5368 | ** |
5369 | ** ^Information about the ORDER BY clause is stored in aOrderBy[]. |
5370 | ** ^Each term of aOrderBy records a column of the ORDER BY clause. |
5371 | ** |
5372 | ** The [xBestIndex] method must fill aConstraintUsage[] with information |
5373 | ** about what parameters to pass to xFilter. ^If argvIndex>0 then |
5374 | ** the right-hand side of the corresponding aConstraint[] is evaluated |
5375 | ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit |
5376 | ** is true, then the constraint is assumed to be fully handled by the |
5377 | ** virtual table and is not checked again by SQLite.)^ |
5378 | ** |
5379 | ** ^The idxNum and idxPtr values are recorded and passed into the |
5380 | ** [xFilter] method. |
5381 | ** ^[sqlite3_free()] is used to free idxPtr if and only if |
5382 | ** needToFreeIdxPtr is true. |
5383 | ** |
5384 | ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in |
5385 | ** the correct order to satisfy the ORDER BY clause so that no separate |
5386 | ** sorting step is required. |
5387 | ** |
5388 | ** ^The estimatedCost value is an estimate of the cost of a particular |
5389 | ** strategy. A cost of N indicates that the cost of the strategy is similar |
5390 | ** to a linear scan of an SQLite table with N rows. A cost of log(N) |
5391 | ** indicates that the expense of the operation is similar to that of a |
5392 | ** binary search on a unique indexed field of an SQLite table with N rows. |
5393 | ** |
5394 | ** ^The estimatedRows value is an estimate of the number of rows that |
5395 | ** will be returned by the strategy. |
5396 | ** |
5397 | ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info |
5398 | ** structure for SQLite version 3.8.2. If a virtual table extension is |
5399 | ** used with an SQLite version earlier than 3.8.2, the results of attempting |
5400 | ** to read or write the estimatedRows field are undefined (but are likely |
5401 | ** to included crashing the application). The estimatedRows field should |
5402 | ** therefore only be used if [sqlite3_libversion_number()] returns a |
5403 | ** value greater than or equal to 3008002. |
5404 | */ |
5405 | struct sqlite3_index_info { |
5406 | /* Inputs */ |
5407 | int nConstraint; /* Number of entries in aConstraint */ |
5408 | struct sqlite3_index_constraint { |
5409 | int iColumn; /* Column on left-hand side of constraint */ |
5410 | unsigned char op; /* Constraint operator */ |
5411 | unsigned char usable; /* True if this constraint is usable */ |
5412 | int iTermOffset; /* Used internally - xBestIndex should ignore */ |
5413 | } *aConstraint; /* Table of WHERE clause constraints */ |
5414 | int nOrderBy; /* Number of terms in the ORDER BY clause */ |
5415 | struct sqlite3_index_orderby { |
5416 | int iColumn; /* Column number */ |
5417 | unsigned char desc; /* True for DESC. False for ASC. */ |
5418 | } *aOrderBy; /* The ORDER BY clause */ |
5419 | /* Outputs */ |
5420 | struct sqlite3_index_constraint_usage { |
5421 | int argvIndex; /* if >0, constraint is part of argv to xFilter */ |
5422 | unsigned char omit; /* Do not code a test for this constraint */ |
5423 | } *aConstraintUsage; |
5424 | int idxNum; /* Number used to identify the index */ |
5425 | char *idxStr; /* String, possibly obtained from sqlite3_malloc */ |
5426 | int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ |
5427 | int orderByConsumed; /* True if output is already ordered */ |
5428 | double estimatedCost; /* Estimated cost of using this index */ |
5429 | /* Fields below are only available in SQLite 3.8.2 and later */ |
5430 | sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ |
5431 | }; |
5432 | |
5433 | /* |
5434 | ** CAPI3REF: Virtual Table Constraint Operator Codes |
5435 | ** |
5436 | ** These macros defined the allowed values for the |
5437 | ** [sqlite3_index_info].aConstraint[].op field. Each value represents |
5438 | ** an operator that is part of a constraint term in the wHERE clause of |
5439 | ** a query that uses a [virtual table]. |
5440 | */ |
5441 | #define SQLITE_INDEX_CONSTRAINT_EQ 2 |
5442 | #define SQLITE_INDEX_CONSTRAINT_GT 4 |
5443 | #define SQLITE_INDEX_CONSTRAINT_LE 8 |
5444 | #define SQLITE_INDEX_CONSTRAINT_LT 16 |
5445 | #define SQLITE_INDEX_CONSTRAINT_GE 32 |
5446 | #define SQLITE_INDEX_CONSTRAINT_MATCH 64 |
5447 | |
5448 | /* |
5449 | ** CAPI3REF: Register A Virtual Table Implementation |
5450 | ** |
5451 | ** ^These routines are used to register a new [virtual table module] name. |
5452 | ** ^Module names must be registered before |
5453 | ** creating a new [virtual table] using the module and before using a |
5454 | ** preexisting [virtual table] for the module. |
5455 | ** |
5456 | ** ^The module name is registered on the [database connection] specified |
5457 | ** by the first parameter. ^The name of the module is given by the |
5458 | ** second parameter. ^The third parameter is a pointer to |
5459 | ** the implementation of the [virtual table module]. ^The fourth |
5460 | ** parameter is an arbitrary client data pointer that is passed through |
5461 | ** into the [xCreate] and [xConnect] methods of the virtual table module |
5462 | ** when a new virtual table is be being created or reinitialized. |
5463 | ** |
5464 | ** ^The sqlite3_create_module_v2() interface has a fifth parameter which |
5465 | ** is a pointer to a destructor for the pClientData. ^SQLite will |
5466 | ** invoke the destructor function (if it is not NULL) when SQLite |
5467 | ** no longer needs the pClientData pointer. ^The destructor will also |
5468 | ** be invoked if the call to sqlite3_create_module_v2() fails. |
5469 | ** ^The sqlite3_create_module() |
5470 | ** interface is equivalent to sqlite3_create_module_v2() with a NULL |
5471 | ** destructor. |
5472 | */ |
5473 | SQLITE_API int sqlite3_create_module( |
5474 | sqlite3 *db, /* SQLite connection to register module with */ |
5475 | const char *zName, /* Name of the module */ |
5476 | const sqlite3_module *p, /* Methods for the module */ |
5477 | void *pClientData /* Client data for xCreate/xConnect */ |
5478 | ); |
5479 | SQLITE_API int sqlite3_create_module_v2( |
5480 | sqlite3 *db, /* SQLite connection to register module with */ |
5481 | const char *zName, /* Name of the module */ |
5482 | const sqlite3_module *p, /* Methods for the module */ |
5483 | void *pClientData, /* Client data for xCreate/xConnect */ |
5484 | void(*xDestroy)(void*) /* Module destructor function */ |
5485 | ); |
5486 | |
5487 | /* |
5488 | ** CAPI3REF: Virtual Table Instance Object |
5489 | ** KEYWORDS: sqlite3_vtab |
5490 | ** |
5491 | ** Every [virtual table module] implementation uses a subclass |
5492 | ** of this object to describe a particular instance |
5493 | ** of the [virtual table]. Each subclass will |
5494 | ** be tailored to the specific needs of the module implementation. |
5495 | ** The purpose of this superclass is to define certain fields that are |
5496 | ** common to all module implementations. |
5497 | ** |
5498 | ** ^Virtual tables methods can set an error message by assigning a |
5499 | ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should |
5500 | ** take care that any prior string is freed by a call to [sqlite3_free()] |
5501 | ** prior to assigning a new string to zErrMsg. ^After the error message |
5502 | ** is delivered up to the client application, the string will be automatically |
5503 | ** freed by sqlite3_free() and the zErrMsg field will be zeroed. |
5504 | */ |
5505 | struct sqlite3_vtab { |
5506 | const sqlite3_module *pModule; /* The module for this virtual table */ |
5507 | int nRef; /* NO LONGER USED */ |
5508 | char *zErrMsg; /* Error message from sqlite3_mprintf() */ |
5509 | /* Virtual table implementations will typically add additional fields */ |
5510 | }; |
5511 | |
5512 | /* |
5513 | ** CAPI3REF: Virtual Table Cursor Object |
5514 | ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} |
5515 | ** |
5516 | ** Every [virtual table module] implementation uses a subclass of the |
5517 | ** following structure to describe cursors that point into the |
5518 | ** [virtual table] and are used |
5519 | ** to loop through the virtual table. Cursors are created using the |
5520 | ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed |
5521 | ** by the [sqlite3_module.xClose | xClose] method. Cursors are used |
5522 | ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods |
5523 | ** of the module. Each module implementation will define |
5524 | ** the content of a cursor structure to suit its own needs. |
5525 | ** |
5526 | ** This superclass exists in order to define fields of the cursor that |
5527 | ** are common to all implementations. |
5528 | */ |
5529 | struct sqlite3_vtab_cursor { |
5530 | sqlite3_vtab *pVtab; /* Virtual table of this cursor */ |
5531 | /* Virtual table implementations will typically add additional fields */ |
5532 | }; |
5533 | |
5534 | /* |
5535 | ** CAPI3REF: Declare The Schema Of A Virtual Table |
5536 | ** |
5537 | ** ^The [xCreate] and [xConnect] methods of a |
5538 | ** [virtual table module] call this interface |
5539 | ** to declare the format (the names and datatypes of the columns) of |
5540 | ** the virtual tables they implement. |
5541 | */ |
5542 | SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL); |
5543 | |
5544 | /* |
5545 | ** CAPI3REF: Overload A Function For A Virtual Table |
5546 | ** |
5547 | ** ^(Virtual tables can provide alternative implementations of functions |
5548 | ** using the [xFindFunction] method of the [virtual table module]. |
5549 | ** But global versions of those functions |
5550 | ** must exist in order to be overloaded.)^ |
5551 | ** |
5552 | ** ^(This API makes sure a global version of a function with a particular |
5553 | ** name and number of parameters exists. If no such function exists |
5554 | ** before this API is called, a new function is created.)^ ^The implementation |
5555 | ** of the new function always causes an exception to be thrown. So |
5556 | ** the new function is not good for anything by itself. Its only |
5557 | ** purpose is to be a placeholder function that can be overloaded |
5558 | ** by a [virtual table]. |
5559 | */ |
5560 | SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); |
5561 | |
5562 | /* |
5563 | ** The interface to the virtual-table mechanism defined above (back up |
5564 | ** to a comment remarkably similar to this one) is currently considered |
5565 | ** to be experimental. The interface might change in incompatible ways. |
5566 | ** If this is a problem for you, do not use the interface at this time. |
5567 | ** |
5568 | ** When the virtual-table mechanism stabilizes, we will declare the |
5569 | ** interface fixed, support it indefinitely, and remove this comment. |
5570 | */ |
5571 | |
5572 | /* |
5573 | ** CAPI3REF: A Handle To An Open BLOB |
5574 | ** KEYWORDS: {BLOB handle} {BLOB handles} |
5575 | ** |
5576 | ** An instance of this object represents an open BLOB on which |
5577 | ** [sqlite3_blob_open | incremental BLOB I/O] can be performed. |
5578 | ** ^Objects of this type are created by [sqlite3_blob_open()] |
5579 | ** and destroyed by [sqlite3_blob_close()]. |
5580 | ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces |
5581 | ** can be used to read or write small subsections of the BLOB. |
5582 | ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. |
5583 | */ |
5584 | typedef struct sqlite3_blob sqlite3_blob; |
5585 | |
5586 | /* |
5587 | ** CAPI3REF: Open A BLOB For Incremental I/O |
5588 | ** |
5589 | ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located |
5590 | ** in row iRow, column zColumn, table zTable in database zDb; |
5591 | ** in other words, the same BLOB that would be selected by: |
5592 | ** |
5593 | ** <pre> |
5594 | ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; |
5595 | ** </pre>)^ |
5596 | ** |
5597 | ** ^If the flags parameter is non-zero, then the BLOB is opened for read |
5598 | ** and write access. ^If it is zero, the BLOB is opened for read access. |
5599 | ** ^It is not possible to open a column that is part of an index or primary |
5600 | ** key for writing. ^If [foreign key constraints] are enabled, it is |
5601 | ** not possible to open a column that is part of a [child key] for writing. |
5602 | ** |
5603 | ** ^Note that the database name is not the filename that contains |
5604 | ** the database but rather the symbolic name of the database that |
5605 | ** appears after the AS keyword when the database is connected using [ATTACH]. |
5606 | ** ^For the main database file, the database name is "main". |
5607 | ** ^For TEMP tables, the database name is "temp". |
5608 | ** |
5609 | ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is written |
5610 | ** to *ppBlob. Otherwise an [error code] is returned and *ppBlob is set |
5611 | ** to be a null pointer.)^ |
5612 | ** ^This function sets the [database connection] error code and message |
5613 | ** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()] and related |
5614 | ** functions. ^Note that the *ppBlob variable is always initialized in a |
5615 | ** way that makes it safe to invoke [sqlite3_blob_close()] on *ppBlob |
5616 | ** regardless of the success or failure of this routine. |
5617 | ** |
5618 | ** ^(If the row that a BLOB handle points to is modified by an |
5619 | ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects |
5620 | ** then the BLOB handle is marked as "expired". |
5621 | ** This is true if any column of the row is changed, even a column |
5622 | ** other than the one the BLOB handle is open on.)^ |
5623 | ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for |
5624 | ** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. |
5625 | ** ^(Changes written into a BLOB prior to the BLOB expiring are not |
5626 | ** rolled back by the expiration of the BLOB. Such changes will eventually |
5627 | ** commit if the transaction continues to completion.)^ |
5628 | ** |
5629 | ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of |
5630 | ** the opened blob. ^The size of a blob may not be changed by this |
5631 | ** interface. Use the [UPDATE] SQL command to change the size of a |
5632 | ** blob. |
5633 | ** |
5634 | ** ^The [sqlite3_blob_open()] interface will fail for a [WITHOUT ROWID] |
5635 | ** table. Incremental BLOB I/O is not possible on [WITHOUT ROWID] tables. |
5636 | ** |
5637 | ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces |
5638 | ** and the built-in [zeroblob] SQL function can be used, if desired, |
5639 | ** to create an empty, zero-filled blob in which to read or write using |
5640 | ** this interface. |
5641 | ** |
5642 | ** To avoid a resource leak, every open [BLOB handle] should eventually |
5643 | ** be released by a call to [sqlite3_blob_close()]. |
5644 | */ |
5645 | SQLITE_API int sqlite3_blob_open( |
5646 | sqlite3*, |
5647 | const char *zDb, |
5648 | const char *zTable, |
5649 | const char *zColumn, |
5650 | sqlite3_int64 iRow, |
5651 | int flags, |
5652 | sqlite3_blob **ppBlob |
5653 | ); |
5654 | |
5655 | /* |
5656 | ** CAPI3REF: Move a BLOB Handle to a New Row |
5657 | ** |
5658 | ** ^This function is used to move an existing blob handle so that it points |
5659 | ** to a different row of the same database table. ^The new row is identified |
5660 | ** by the rowid value passed as the second argument. Only the row can be |
5661 | ** changed. ^The database, table and column on which the blob handle is open |
5662 | ** remain the same. Moving an existing blob handle to a new row can be |
5663 | ** faster than closing the existing handle and opening a new one. |
5664 | ** |
5665 | ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - |
5666 | ** it must exist and there must be either a blob or text value stored in |
5667 | ** the nominated column.)^ ^If the new row is not present in the table, or if |
5668 | ** it does not contain a blob or text value, or if another error occurs, an |
5669 | ** SQLite error code is returned and the blob handle is considered aborted. |
5670 | ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or |
5671 | ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return |
5672 | ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle |
5673 | ** always returns zero. |
5674 | ** |
5675 | ** ^This function sets the database handle error code and message. |
5676 | */ |
5677 | SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); |
5678 | |
5679 | /* |
5680 | ** CAPI3REF: Close A BLOB Handle |
5681 | ** |
5682 | ** ^Closes an open [BLOB handle]. |
5683 | ** |
5684 | ** ^Closing a BLOB shall cause the current transaction to commit |
5685 | ** if there are no other BLOBs, no pending prepared statements, and the |
5686 | ** database connection is in [autocommit mode]. |
5687 | ** ^If any writes were made to the BLOB, they might be held in cache |
5688 | ** until the close operation if they will fit. |
5689 | ** |
5690 | ** ^(Closing the BLOB often forces the changes |
5691 | ** out to disk and so if any I/O errors occur, they will likely occur |
5692 | ** at the time when the BLOB is closed. Any errors that occur during |
5693 | ** closing are reported as a non-zero return value.)^ |
5694 | ** |
5695 | ** ^(The BLOB is closed unconditionally. Even if this routine returns |
5696 | ** an error code, the BLOB is still closed.)^ |
5697 | ** |
5698 | ** ^Calling this routine with a null pointer (such as would be returned |
5699 | ** by a failed call to [sqlite3_blob_open()]) is a harmless no-op. |
5700 | */ |
5701 | SQLITE_API int sqlite3_blob_close(sqlite3_blob *); |
5702 | |
5703 | /* |
5704 | ** CAPI3REF: Return The Size Of An Open BLOB |
5705 | ** |
5706 | ** ^Returns the size in bytes of the BLOB accessible via the |
5707 | ** successfully opened [BLOB handle] in its only argument. ^The |
5708 | ** incremental blob I/O routines can only read or overwriting existing |
5709 | ** blob content; they cannot change the size of a blob. |
5710 | ** |
5711 | ** This routine only works on a [BLOB handle] which has been created |
5712 | ** by a prior successful call to [sqlite3_blob_open()] and which has not |
5713 | ** been closed by [sqlite3_blob_close()]. Passing any other pointer in |
5714 | ** to this routine results in undefined and probably undesirable behavior. |
5715 | */ |
5716 | SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *); |
5717 | |
5718 | /* |
5719 | ** CAPI3REF: Read Data From A BLOB Incrementally |
5720 | ** |
5721 | ** ^(This function is used to read data from an open [BLOB handle] into a |
5722 | ** caller-supplied buffer. N bytes of data are copied into buffer Z |
5723 | ** from the open BLOB, starting at offset iOffset.)^ |
5724 | ** |
5725 | ** ^If offset iOffset is less than N bytes from the end of the BLOB, |
5726 | ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is |
5727 | ** less than zero, [SQLITE_ERROR] is returned and no data is read. |
5728 | ** ^The size of the blob (and hence the maximum value of N+iOffset) |
5729 | ** can be determined using the [sqlite3_blob_bytes()] interface. |
5730 | ** |
5731 | ** ^An attempt to read from an expired [BLOB handle] fails with an |
5732 | ** error code of [SQLITE_ABORT]. |
5733 | ** |
5734 | ** ^(On success, sqlite3_blob_read() returns SQLITE_OK. |
5735 | ** Otherwise, an [error code] or an [extended error code] is returned.)^ |
5736 | ** |
5737 | ** This routine only works on a [BLOB handle] which has been created |
5738 | ** by a prior successful call to [sqlite3_blob_open()] and which has not |
5739 | ** been closed by [sqlite3_blob_close()]. Passing any other pointer in |
5740 | ** to this routine results in undefined and probably undesirable behavior. |
5741 | ** |
5742 | ** See also: [sqlite3_blob_write()]. |
5743 | */ |
5744 | SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); |
5745 | |
5746 | /* |
5747 | ** CAPI3REF: Write Data Into A BLOB Incrementally |
5748 | ** |
5749 | ** ^This function is used to write data into an open [BLOB handle] from a |
5750 | ** caller-supplied buffer. ^N bytes of data are copied from the buffer Z |
5751 | ** into the open BLOB, starting at offset iOffset. |
5752 | ** |
5753 | ** ^If the [BLOB handle] passed as the first argument was not opened for |
5754 | ** writing (the flags parameter to [sqlite3_blob_open()] was zero), |
5755 | ** this function returns [SQLITE_READONLY]. |
5756 | ** |
5757 | ** ^This function may only modify the contents of the BLOB; it is |
5758 | ** not possible to increase the size of a BLOB using this API. |
5759 | ** ^If offset iOffset is less than N bytes from the end of the BLOB, |
5760 | ** [SQLITE_ERROR] is returned and no data is written. ^If N is |
5761 | ** less than zero [SQLITE_ERROR] is returned and no data is written. |
5762 | ** The size of the BLOB (and hence the maximum value of N+iOffset) |
5763 | ** can be determined using the [sqlite3_blob_bytes()] interface. |
5764 | ** |
5765 | ** ^An attempt to write to an expired [BLOB handle] fails with an |
5766 | ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred |
5767 | ** before the [BLOB handle] expired are not rolled back by the |
5768 | ** expiration of the handle, though of course those changes might |
5769 | ** have been overwritten by the statement that expired the BLOB handle |
5770 | ** or by other independent statements. |
5771 | ** |
5772 | ** ^(On success, sqlite3_blob_write() returns SQLITE_OK. |
5773 | ** Otherwise, an [error code] or an [extended error code] is returned.)^ |
5774 | ** |
5775 | ** This routine only works on a [BLOB handle] which has been created |
5776 | ** by a prior successful call to [sqlite3_blob_open()] and which has not |
5777 | ** been closed by [sqlite3_blob_close()]. Passing any other pointer in |
5778 | ** to this routine results in undefined and probably undesirable behavior. |
5779 | ** |
5780 | ** See also: [sqlite3_blob_read()]. |
5781 | */ |
5782 | SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); |
5783 | |
5784 | /* |
5785 | ** CAPI3REF: Virtual File System Objects |
5786 | ** |
5787 | ** A virtual filesystem (VFS) is an [sqlite3_vfs] object |
5788 | ** that SQLite uses to interact |
5789 | ** with the underlying operating system. Most SQLite builds come with a |
5790 | ** single default VFS that is appropriate for the host computer. |
5791 | ** New VFSes can be registered and existing VFSes can be unregistered. |
5792 | ** The following interfaces are provided. |
5793 | ** |
5794 | ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. |
5795 | ** ^Names are case sensitive. |
5796 | ** ^Names are zero-terminated UTF-8 strings. |
5797 | ** ^If there is no match, a NULL pointer is returned. |
5798 | ** ^If zVfsName is NULL then the default VFS is returned. |
5799 | ** |
5800 | ** ^New VFSes are registered with sqlite3_vfs_register(). |
5801 | ** ^Each new VFS becomes the default VFS if the makeDflt flag is set. |
5802 | ** ^The same VFS can be registered multiple times without injury. |
5803 | ** ^To make an existing VFS into the default VFS, register it again |
5804 | ** with the makeDflt flag set. If two different VFSes with the |
5805 | ** same name are registered, the behavior is undefined. If a |
5806 | ** VFS is registered with a name that is NULL or an empty string, |
5807 | ** then the behavior is undefined. |
5808 | ** |
5809 | ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. |
5810 | ** ^(If the default VFS is unregistered, another VFS is chosen as |
5811 | ** the default. The choice for the new VFS is arbitrary.)^ |
5812 | */ |
5813 | SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); |
5814 | SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); |
5815 | SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*); |
5816 | |
5817 | /* |
5818 | ** CAPI3REF: Mutexes |
5819 | ** |
5820 | ** The SQLite core uses these routines for thread |
5821 | ** synchronization. Though they are intended for internal |
5822 | ** use by SQLite, code that links against SQLite is |
5823 | ** permitted to use any of these routines. |
5824 | ** |
5825 | ** The SQLite source code contains multiple implementations |
5826 | ** of these mutex routines. An appropriate implementation |
5827 | ** is selected automatically at compile-time. ^(The following |
5828 | ** implementations are available in the SQLite core: |
5829 | ** |
5830 | ** <ul> |
5831 | ** <li> SQLITE_MUTEX_PTHREADS |
5832 | ** <li> SQLITE_MUTEX_W32 |
5833 | ** <li> SQLITE_MUTEX_NOOP |
5834 | ** </ul>)^ |
5835 | ** |
5836 | ** ^The SQLITE_MUTEX_NOOP implementation is a set of routines |
5837 | ** that does no real locking and is appropriate for use in |
5838 | ** a single-threaded application. ^The SQLITE_MUTEX_PTHREADS and |
5839 | ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix |
5840 | ** and Windows. |
5841 | ** |
5842 | ** ^(If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor |
5843 | ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex |
5844 | ** implementation is included with the library. In this case the |
5845 | ** application must supply a custom mutex implementation using the |
5846 | ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function |
5847 | ** before calling sqlite3_initialize() or any other public sqlite3_ |
5848 | ** function that calls sqlite3_initialize().)^ |
5849 | ** |
5850 | ** ^The sqlite3_mutex_alloc() routine allocates a new |
5851 | ** mutex and returns a pointer to it. ^If it returns NULL |
5852 | ** that means that a mutex could not be allocated. ^SQLite |
5853 | ** will unwind its stack and return an error. ^(The argument |
5854 | ** to sqlite3_mutex_alloc() is one of these integer constants: |
5855 | ** |
5856 | ** <ul> |
5857 | ** <li> SQLITE_MUTEX_FAST |
5858 | ** <li> SQLITE_MUTEX_RECURSIVE |
5859 | ** <li> SQLITE_MUTEX_STATIC_MASTER |
5860 | ** <li> SQLITE_MUTEX_STATIC_MEM |
5861 | ** <li> SQLITE_MUTEX_STATIC_MEM2 |
5862 | ** <li> SQLITE_MUTEX_STATIC_PRNG |
5863 | ** <li> SQLITE_MUTEX_STATIC_LRU |
5864 | ** <li> SQLITE_MUTEX_STATIC_LRU2 |
5865 | ** </ul>)^ |
5866 | ** |
5867 | ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) |
5868 | ** cause sqlite3_mutex_alloc() to create |
5869 | ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE |
5870 | ** is used but not necessarily so when SQLITE_MUTEX_FAST is used. |
5871 | ** The mutex implementation does not need to make a distinction |
5872 | ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does |
5873 | ** not want to. ^SQLite will only request a recursive mutex in |
5874 | ** cases where it really needs one. ^If a faster non-recursive mutex |
5875 | ** implementation is available on the host platform, the mutex subsystem |
5876 | ** might return such a mutex in response to SQLITE_MUTEX_FAST. |
5877 | ** |
5878 | ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other |
5879 | ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return |
5880 | ** a pointer to a static preexisting mutex. ^Six static mutexes are |
5881 | ** used by the current version of SQLite. Future versions of SQLite |
5882 | ** may add additional static mutexes. Static mutexes are for internal |
5883 | ** use by SQLite only. Applications that use SQLite mutexes should |
5884 | ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or |
5885 | ** SQLITE_MUTEX_RECURSIVE. |
5886 | ** |
5887 | ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST |
5888 | ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() |
5889 | ** returns a different mutex on every call. ^But for the static |
5890 | ** mutex types, the same mutex is returned on every call that has |
5891 | ** the same type number. |
5892 | ** |
5893 | ** ^The sqlite3_mutex_free() routine deallocates a previously |
5894 | ** allocated dynamic mutex. ^SQLite is careful to deallocate every |
5895 | ** dynamic mutex that it allocates. The dynamic mutexes must not be in |
5896 | ** use when they are deallocated. Attempting to deallocate a static |
5897 | ** mutex results in undefined behavior. ^SQLite never deallocates |
5898 | ** a static mutex. |
5899 | ** |
5900 | ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt |
5901 | ** to enter a mutex. ^If another thread is already within the mutex, |
5902 | ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return |
5903 | ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] |
5904 | ** upon successful entry. ^(Mutexes created using |
5905 | ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. |
5906 | ** In such cases the, |
5907 | ** mutex must be exited an equal number of times before another thread |
5908 | ** can enter.)^ ^(If the same thread tries to enter any other |
5909 | ** kind of mutex more than once, the behavior is undefined. |
5910 | ** SQLite will never exhibit |
5911 | ** such behavior in its own use of mutexes.)^ |
5912 | ** |
5913 | ** ^(Some systems (for example, Windows 95) do not support the operation |
5914 | ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() |
5915 | ** will always return SQLITE_BUSY. The SQLite core only ever uses |
5916 | ** sqlite3_mutex_try() as an optimization so this is acceptable behavior.)^ |
5917 | ** |
5918 | ** ^The sqlite3_mutex_leave() routine exits a mutex that was |
5919 | ** previously entered by the same thread. ^(The behavior |
5920 | ** is undefined if the mutex is not currently entered by the |
5921 | ** calling thread or is not currently allocated. SQLite will |
5922 | ** never do either.)^ |
5923 | ** |
5924 | ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or |
5925 | ** sqlite3_mutex_leave() is a NULL pointer, then all three routines |
5926 | ** behave as no-ops. |
5927 | ** |
5928 | ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. |
5929 | */ |
5930 | SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int); |
5931 | SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*); |
5932 | SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*); |
5933 | SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*); |
5934 | SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*); |
5935 | |
5936 | /* |
5937 | ** CAPI3REF: Mutex Methods Object |
5938 | ** |
5939 | ** An instance of this structure defines the low-level routines |
5940 | ** used to allocate and use mutexes. |
5941 | ** |
5942 | ** Usually, the default mutex implementations provided by SQLite are |
5943 | ** sufficient, however the user has the option of substituting a custom |
5944 | ** implementation for specialized deployments or systems for which SQLite |
5945 | ** does not provide a suitable implementation. In this case, the user |
5946 | ** creates and populates an instance of this structure to pass |
5947 | ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. |
5948 | ** Additionally, an instance of this structure can be used as an |
5949 | ** output variable when querying the system for the current mutex |
5950 | ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. |
5951 | ** |
5952 | ** ^The xMutexInit method defined by this structure is invoked as |
5953 | ** part of system initialization by the sqlite3_initialize() function. |
5954 | ** ^The xMutexInit routine is called by SQLite exactly once for each |
5955 | ** effective call to [sqlite3_initialize()]. |
5956 | ** |
5957 | ** ^The xMutexEnd method defined by this structure is invoked as |
5958 | ** part of system shutdown by the sqlite3_shutdown() function. The |
5959 | ** implementation of this method is expected to release all outstanding |
5960 | ** resources obtained by the mutex methods implementation, especially |
5961 | ** those obtained by the xMutexInit method. ^The xMutexEnd() |
5962 | ** interface is invoked exactly once for each call to [sqlite3_shutdown()]. |
5963 | ** |
5964 | ** ^(The remaining seven methods defined by this structure (xMutexAlloc, |
5965 | ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and |
5966 | ** xMutexNotheld) implement the following interfaces (respectively): |
5967 | ** |
5968 | ** <ul> |
5969 | ** <li> [sqlite3_mutex_alloc()] </li> |
5970 | ** <li> [sqlite3_mutex_free()] </li> |
5971 | ** <li> [sqlite3_mutex_enter()] </li> |
5972 | ** <li> [sqlite3_mutex_try()] </li> |
5973 | ** <li> [sqlite3_mutex_leave()] </li> |
5974 | ** <li> [sqlite3_mutex_held()] </li> |
5975 | ** <li> [sqlite3_mutex_notheld()] </li> |
5976 | ** </ul>)^ |
5977 | ** |
5978 | ** The only difference is that the public sqlite3_XXX functions enumerated |
5979 | ** above silently ignore any invocations that pass a NULL pointer instead |
5980 | ** of a valid mutex handle. The implementations of the methods defined |
5981 | ** by this structure are not required to handle this case, the results |
5982 | ** of passing a NULL pointer instead of a valid mutex handle are undefined |
5983 | ** (i.e. it is acceptable to provide an implementation that segfaults if |
5984 | ** it is passed a NULL pointer). |
5985 | ** |
5986 | ** The xMutexInit() method must be threadsafe. ^It must be harmless to |
5987 | ** invoke xMutexInit() multiple times within the same process and without |
5988 | ** intervening calls to xMutexEnd(). Second and subsequent calls to |
5989 | ** xMutexInit() must be no-ops. |
5990 | ** |
5991 | ** ^xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] |
5992 | ** and its associates). ^Similarly, xMutexAlloc() must not use SQLite memory |
5993 | ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite |
5994 | ** memory allocation for a fast or recursive mutex. |
5995 | ** |
5996 | ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is |
5997 | ** called, but only if the prior call to xMutexInit returned SQLITE_OK. |
5998 | ** If xMutexInit fails in any way, it is expected to clean up after itself |
5999 | ** prior to returning. |
6000 | */ |
6001 | typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; |
6002 | struct sqlite3_mutex_methods { |
6003 | int (*xMutexInit)(void); |
6004 | int (*xMutexEnd)(void); |
6005 | sqlite3_mutex *(*xMutexAlloc)(int); |
6006 | void (*xMutexFree)(sqlite3_mutex *); |
6007 | void (*xMutexEnter)(sqlite3_mutex *); |
6008 | int (*xMutexTry)(sqlite3_mutex *); |
6009 | void (*xMutexLeave)(sqlite3_mutex *); |
6010 | int (*xMutexHeld)(sqlite3_mutex *); |
6011 | int (*xMutexNotheld)(sqlite3_mutex *); |
6012 | }; |
6013 | |
6014 | /* |
6015 | ** CAPI3REF: Mutex Verification Routines |
6016 | ** |
6017 | ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines |
6018 | ** are intended for use inside assert() statements. ^The SQLite core |
6019 | ** never uses these routines except inside an assert() and applications |
6020 | ** are advised to follow the lead of the core. ^The SQLite core only |
6021 | ** provides implementations for these routines when it is compiled |
6022 | ** with the SQLITE_DEBUG flag. ^External mutex implementations |
6023 | ** are only required to provide these routines if SQLITE_DEBUG is |
6024 | ** defined and if NDEBUG is not defined. |
6025 | ** |
6026 | ** ^These routines should return true if the mutex in their argument |
6027 | ** is held or not held, respectively, by the calling thread. |
6028 | ** |
6029 | ** ^The implementation is not required to provide versions of these |
6030 | ** routines that actually work. If the implementation does not provide working |
6031 | ** versions of these routines, it should at least provide stubs that always |
6032 | ** return true so that one does not get spurious assertion failures. |
6033 | ** |
6034 | ** ^If the argument to sqlite3_mutex_held() is a NULL pointer then |
6035 | ** the routine should return 1. This seems counter-intuitive since |
6036 | ** clearly the mutex cannot be held if it does not exist. But |
6037 | ** the reason the mutex does not exist is because the build is not |
6038 | ** using mutexes. And we do not want the assert() containing the |
6039 | ** call to sqlite3_mutex_held() to fail, so a non-zero return is |
6040 | ** the appropriate thing to do. ^The sqlite3_mutex_notheld() |
6041 | ** interface should also return 1 when given a NULL pointer. |
6042 | */ |
6043 | #ifndef NDEBUG |
6044 | SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*); |
6045 | SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*); |
6046 | #endif |
6047 | |
6048 | /* |
6049 | ** CAPI3REF: Mutex Types |
6050 | ** |
6051 | ** The [sqlite3_mutex_alloc()] interface takes a single argument |
6052 | ** which is one of these integer constants. |
6053 | ** |
6054 | ** The set of static mutexes may change from one SQLite release to the |
6055 | ** next. Applications that override the built-in mutex logic must be |
6056 | ** prepared to accommodate additional static mutexes. |
6057 | */ |
6058 | #define SQLITE_MUTEX_FAST 0 |
6059 | #define SQLITE_MUTEX_RECURSIVE 1 |
6060 | #define SQLITE_MUTEX_STATIC_MASTER 2 |
6061 | #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ |
6062 | #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ |
6063 | #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ |
6064 | #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */ |
6065 | #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ |
6066 | #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ |
6067 | #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ |
6068 | |
6069 | /* |
6070 | ** CAPI3REF: Retrieve the mutex for a database connection |
6071 | ** |
6072 | ** ^This interface returns a pointer the [sqlite3_mutex] object that |
6073 | ** serializes access to the [database connection] given in the argument |
6074 | ** when the [threading mode] is Serialized. |
6075 | ** ^If the [threading mode] is Single-thread or Multi-thread then this |
6076 | ** routine returns a NULL pointer. |
6077 | */ |
6078 | SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*); |
6079 | |
6080 | /* |
6081 | ** CAPI3REF: Low-Level Control Of Database Files |
6082 | ** |
6083 | ** ^The [sqlite3_file_control()] interface makes a direct call to the |
6084 | ** xFileControl method for the [sqlite3_io_methods] object associated |
6085 | ** with a particular database identified by the second argument. ^The |
6086 | ** name of the database is "main" for the main database or "temp" for the |
6087 | ** TEMP database, or the name that appears after the AS keyword for |
6088 | ** databases that are added using the [ATTACH] SQL command. |
6089 | ** ^A NULL pointer can be used in place of "main" to refer to the |
6090 | ** main database file. |
6091 | ** ^The third and fourth parameters to this routine |
6092 | ** are passed directly through to the second and third parameters of |
6093 | ** the xFileControl method. ^The return value of the xFileControl |
6094 | ** method becomes the return value of this routine. |
6095 | ** |
6096 | ** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes |
6097 | ** a pointer to the underlying [sqlite3_file] object to be written into |
6098 | ** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER |
6099 | ** case is a short-circuit path which does not actually invoke the |
6100 | ** underlying sqlite3_io_methods.xFileControl method. |
6101 | ** |
6102 | ** ^If the second parameter (zDbName) does not match the name of any |
6103 | ** open database file, then SQLITE_ERROR is returned. ^This error |
6104 | ** code is not remembered and will not be recalled by [sqlite3_errcode()] |
6105 | ** or [sqlite3_errmsg()]. The underlying xFileControl method might |
6106 | ** also return SQLITE_ERROR. There is no way to distinguish between |
6107 | ** an incorrect zDbName and an SQLITE_ERROR return from the underlying |
6108 | ** xFileControl method. |
6109 | ** |
6110 | ** See also: [SQLITE_FCNTL_LOCKSTATE] |
6111 | */ |
6112 | SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); |
6113 | |
6114 | /* |
6115 | ** CAPI3REF: Testing Interface |
6116 | ** |
6117 | ** ^The sqlite3_test_control() interface is used to read out internal |
6118 | ** state of SQLite and to inject faults into SQLite for testing |
6119 | ** purposes. ^The first parameter is an operation code that determines |
6120 | ** the number, meaning, and operation of all subsequent parameters. |
6121 | ** |
6122 | ** This interface is not for use by applications. It exists solely |
6123 | ** for verifying the correct operation of the SQLite library. Depending |
6124 | ** on how the SQLite library is compiled, this interface might not exist. |
6125 | ** |
6126 | ** The details of the operation codes, their meanings, the parameters |
6127 | ** they take, and what they do are all subject to change without notice. |
6128 | ** Unlike most of the SQLite API, this function is not guaranteed to |
6129 | ** operate consistently from one release to the next. |
6130 | */ |
6131 | SQLITE_API int sqlite3_test_control(int op, ...); |
6132 | |
6133 | /* |
6134 | ** CAPI3REF: Testing Interface Operation Codes |
6135 | ** |
6136 | ** These constants are the valid operation code parameters used |
6137 | ** as the first argument to [sqlite3_test_control()]. |
6138 | ** |
6139 | ** These parameters and their meanings are subject to change |
6140 | ** without notice. These values are for testing purposes only. |
6141 | ** Applications should not use any of these parameters or the |
6142 | ** [sqlite3_test_control()] interface. |
6143 | */ |
6144 | #define SQLITE_TESTCTRL_FIRST 5 |
6145 | #define SQLITE_TESTCTRL_PRNG_SAVE 5 |
6146 | #define SQLITE_TESTCTRL_PRNG_RESTORE 6 |
6147 | #define SQLITE_TESTCTRL_PRNG_RESET 7 |
6148 | #define SQLITE_TESTCTRL_BITVEC_TEST 8 |
6149 | #define SQLITE_TESTCTRL_FAULT_INSTALL 9 |
6150 | #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 |
6151 | #define SQLITE_TESTCTRL_PENDING_BYTE 11 |
6152 | #define SQLITE_TESTCTRL_ASSERT 12 |
6153 | #define SQLITE_TESTCTRL_ALWAYS 13 |
6154 | #define SQLITE_TESTCTRL_RESERVE 14 |
6155 | #define SQLITE_TESTCTRL_OPTIMIZATIONS 15 |
6156 | #define SQLITE_TESTCTRL_ISKEYWORD 16 |
6157 | #define SQLITE_TESTCTRL_SCRATCHMALLOC 17 |
6158 | #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 |
6159 | #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 |
6160 | #define SQLITE_TESTCTRL_NEVER_CORRUPT 20 |
6161 | #define SQLITE_TESTCTRL_VDBE_COVERAGE 21 |
6162 | #define SQLITE_TESTCTRL_BYTEORDER 22 |
6163 | #define SQLITE_TESTCTRL_LAST 22 |
6164 | |
6165 | /* |
6166 | ** CAPI3REF: SQLite Runtime Status |
6167 | ** |
6168 | ** ^This interface is used to retrieve runtime status information |
6169 | ** about the performance of SQLite, and optionally to reset various |
6170 | ** highwater marks. ^The first argument is an integer code for |
6171 | ** the specific parameter to measure. ^(Recognized integer codes |
6172 | ** are of the form [status parameters | SQLITE_STATUS_...].)^ |
6173 | ** ^The current value of the parameter is returned into *pCurrent. |
6174 | ** ^The highest recorded value is returned in *pHighwater. ^If the |
6175 | ** resetFlag is true, then the highest record value is reset after |
6176 | ** *pHighwater is written. ^(Some parameters do not record the highest |
6177 | ** value. For those parameters |
6178 | ** nothing is written into *pHighwater and the resetFlag is ignored.)^ |
6179 | ** ^(Other parameters record only the highwater mark and not the current |
6180 | ** value. For these latter parameters nothing is written into *pCurrent.)^ |
6181 | ** |
6182 | ** ^The sqlite3_status() routine returns SQLITE_OK on success and a |
6183 | ** non-zero [error code] on failure. |
6184 | ** |
6185 | ** This routine is threadsafe but is not atomic. This routine can be |
6186 | ** called while other threads are running the same or different SQLite |
6187 | ** interfaces. However the values returned in *pCurrent and |
6188 | ** *pHighwater reflect the status of SQLite at different points in time |
6189 | ** and it is possible that another thread might change the parameter |
6190 | ** in between the times when *pCurrent and *pHighwater are written. |
6191 | ** |
6192 | ** See also: [sqlite3_db_status()] |
6193 | */ |
6194 | SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); |
6195 | |
6196 | |
6197 | /* |
6198 | ** CAPI3REF: Status Parameters |
6199 | ** KEYWORDS: {status parameters} |
6200 | ** |
6201 | ** These integer constants designate various run-time status parameters |
6202 | ** that can be returned by [sqlite3_status()]. |
6203 | ** |
6204 | ** <dl> |
6205 | ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> |
6206 | ** <dd>This parameter is the current amount of memory checked out |
6207 | ** using [sqlite3_malloc()], either directly or indirectly. The |
6208 | ** figure includes calls made to [sqlite3_malloc()] by the application |
6209 | ** and internal memory usage by the SQLite library. Scratch memory |
6210 | ** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache |
6211 | ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in |
6212 | ** this parameter. The amount returned is the sum of the allocation |
6213 | ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ |
6214 | ** |
6215 | ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> |
6216 | ** <dd>This parameter records the largest memory allocation request |
6217 | ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their |
6218 | ** internal equivalents). Only the value returned in the |
6219 | ** *pHighwater parameter to [sqlite3_status()] is of interest. |
6220 | ** The value written into the *pCurrent parameter is undefined.</dd>)^ |
6221 | ** |
6222 | ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> |
6223 | ** <dd>This parameter records the number of separate memory allocations |
6224 | ** currently checked out.</dd>)^ |
6225 | ** |
6226 | ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> |
6227 | ** <dd>This parameter returns the number of pages used out of the |
6228 | ** [pagecache memory allocator] that was configured using |
6229 | ** [SQLITE_CONFIG_PAGECACHE]. The |
6230 | ** value returned is in pages, not in bytes.</dd>)^ |
6231 | ** |
6232 | ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] |
6233 | ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> |
6234 | ** <dd>This parameter returns the number of bytes of page cache |
6235 | ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] |
6236 | ** buffer and where forced to overflow to [sqlite3_malloc()]. The |
6237 | ** returned value includes allocations that overflowed because they |
6238 | ** where too large (they were larger than the "sz" parameter to |
6239 | ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because |
6240 | ** no space was left in the page cache.</dd>)^ |
6241 | ** |
6242 | ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> |
6243 | ** <dd>This parameter records the largest memory allocation request |
6244 | ** handed to [pagecache memory allocator]. Only the value returned in the |
6245 | ** *pHighwater parameter to [sqlite3_status()] is of interest. |
6246 | ** The value written into the *pCurrent parameter is undefined.</dd>)^ |
6247 | ** |
6248 | ** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt> |
6249 | ** <dd>This parameter returns the number of allocations used out of the |
6250 | ** [scratch memory allocator] configured using |
6251 | ** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not |
6252 | ** in bytes. Since a single thread may only have one scratch allocation |
6253 | ** outstanding at time, this parameter also reports the number of threads |
6254 | ** using scratch memory at the same time.</dd>)^ |
6255 | ** |
6256 | ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> |
6257 | ** <dd>This parameter returns the number of bytes of scratch memory |
6258 | ** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH] |
6259 | ** buffer and where forced to overflow to [sqlite3_malloc()]. The values |
6260 | ** returned include overflows because the requested allocation was too |
6261 | ** larger (that is, because the requested allocation was larger than the |
6262 | ** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer |
6263 | ** slots were available. |
6264 | ** </dd>)^ |
6265 | ** |
6266 | ** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt> |
6267 | ** <dd>This parameter records the largest memory allocation request |
6268 | ** handed to [scratch memory allocator]. Only the value returned in the |
6269 | ** *pHighwater parameter to [sqlite3_status()] is of interest. |
6270 | ** The value written into the *pCurrent parameter is undefined.</dd>)^ |
6271 | ** |
6272 | ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> |
6273 | ** <dd>This parameter records the deepest parser stack. It is only |
6274 | ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ |
6275 | ** </dl> |
6276 | ** |
6277 | ** New status parameters may be added from time to time. |
6278 | */ |
6279 | #define SQLITE_STATUS_MEMORY_USED 0 |
6280 | #define SQLITE_STATUS_PAGECACHE_USED 1 |
6281 | #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 |
6282 | #define SQLITE_STATUS_SCRATCH_USED 3 |
6283 | #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 |
6284 | #define SQLITE_STATUS_MALLOC_SIZE 5 |
6285 | #define SQLITE_STATUS_PARSER_STACK 6 |
6286 | #define SQLITE_STATUS_PAGECACHE_SIZE 7 |
6287 | #define SQLITE_STATUS_SCRATCH_SIZE 8 |
6288 | #define SQLITE_STATUS_MALLOC_COUNT 9 |
6289 | |
6290 | /* |
6291 | ** CAPI3REF: Database Connection Status |
6292 | ** |
6293 | ** ^This interface is used to retrieve runtime status information |
6294 | ** about a single [database connection]. ^The first argument is the |
6295 | ** database connection object to be interrogated. ^The second argument |
6296 | ** is an integer constant, taken from the set of |
6297 | ** [SQLITE_DBSTATUS options], that |
6298 | ** determines the parameter to interrogate. The set of |
6299 | ** [SQLITE_DBSTATUS options] is likely |
6300 | ** to grow in future releases of SQLite. |
6301 | ** |
6302 | ** ^The current value of the requested parameter is written into *pCur |
6303 | ** and the highest instantaneous value is written into *pHiwtr. ^If |
6304 | ** the resetFlg is true, then the highest instantaneous value is |
6305 | ** reset back down to the current value. |
6306 | ** |
6307 | ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a |
6308 | ** non-zero [error code] on failure. |
6309 | ** |
6310 | ** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. |
6311 | */ |
6312 | SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); |
6313 | |
6314 | /* |
6315 | ** CAPI3REF: Status Parameters for database connections |
6316 | ** KEYWORDS: {SQLITE_DBSTATUS options} |
6317 | ** |
6318 | ** These constants are the available integer "verbs" that can be passed as |
6319 | ** the second argument to the [sqlite3_db_status()] interface. |
6320 | ** |
6321 | ** New verbs may be added in future releases of SQLite. Existing verbs |
6322 | ** might be discontinued. Applications should check the return code from |
6323 | ** [sqlite3_db_status()] to make sure that the call worked. |
6324 | ** The [sqlite3_db_status()] interface will return a non-zero error code |
6325 | ** if a discontinued or unsupported verb is invoked. |
6326 | ** |
6327 | ** <dl> |
6328 | ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> |
6329 | ** <dd>This parameter returns the number of lookaside memory slots currently |
6330 | ** checked out.</dd>)^ |
6331 | ** |
6332 | ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> |
6333 | ** <dd>This parameter returns the number malloc attempts that were |
6334 | ** satisfied using lookaside memory. Only the high-water value is meaningful; |
6335 | ** the current value is always zero.)^ |
6336 | ** |
6337 | ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] |
6338 | ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> |
6339 | ** <dd>This parameter returns the number malloc attempts that might have |
6340 | ** been satisfied using lookaside memory but failed due to the amount of |
6341 | ** memory requested being larger than the lookaside slot size. |
6342 | ** Only the high-water value is meaningful; |
6343 | ** the current value is always zero.)^ |
6344 | ** |
6345 | ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] |
6346 | ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> |
6347 | ** <dd>This parameter returns the number malloc attempts that might have |
6348 | ** been satisfied using lookaside memory but failed due to all lookaside |
6349 | ** memory already being in use. |
6350 | ** Only the high-water value is meaningful; |
6351 | ** the current value is always zero.)^ |
6352 | ** |
6353 | ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> |
6354 | ** <dd>This parameter returns the approximate number of of bytes of heap |
6355 | ** memory used by all pager caches associated with the database connection.)^ |
6356 | ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. |
6357 | ** |
6358 | ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> |
6359 | ** <dd>This parameter returns the approximate number of of bytes of heap |
6360 | ** memory used to store the schema for all databases associated |
6361 | ** with the connection - main, temp, and any [ATTACH]-ed databases.)^ |
6362 | ** ^The full amount of memory used by the schemas is reported, even if the |
6363 | ** schema memory is shared with other database connections due to |
6364 | ** [shared cache mode] being enabled. |
6365 | ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. |
6366 | ** |
6367 | ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> |
6368 | ** <dd>This parameter returns the approximate number of of bytes of heap |
6369 | ** and lookaside memory used by all prepared statements associated with |
6370 | ** the database connection.)^ |
6371 | ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. |
6372 | ** </dd> |
6373 | ** |
6374 | ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> |
6375 | ** <dd>This parameter returns the number of pager cache hits that have |
6376 | ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT |
6377 | ** is always 0. |
6378 | ** </dd> |
6379 | ** |
6380 | ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> |
6381 | ** <dd>This parameter returns the number of pager cache misses that have |
6382 | ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS |
6383 | ** is always 0. |
6384 | ** </dd> |
6385 | ** |
6386 | ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> |
6387 | ** <dd>This parameter returns the number of dirty cache entries that have |
6388 | ** been written to disk. Specifically, the number of pages written to the |
6389 | ** wal file in wal mode databases, or the number of pages written to the |
6390 | ** database file in rollback mode databases. Any pages written as part of |
6391 | ** transaction rollback or database recovery operations are not included. |
6392 | ** If an IO or other error occurs while writing a page to disk, the effect |
6393 | ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The |
6394 | ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. |
6395 | ** </dd> |
6396 | ** |
6397 | ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> |
6398 | ** <dd>This parameter returns zero for the current value if and only if |
6399 | ** all foreign key constraints (deferred or immediate) have been |
6400 | ** resolved.)^ ^The highwater mark is always 0. |
6401 | ** </dd> |
6402 | ** </dl> |
6403 | */ |
6404 | #define SQLITE_DBSTATUS_LOOKASIDE_USED 0 |
6405 | #define SQLITE_DBSTATUS_CACHE_USED 1 |
6406 | #define SQLITE_DBSTATUS_SCHEMA_USED 2 |
6407 | #define SQLITE_DBSTATUS_STMT_USED 3 |
6408 | #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 |
6409 | #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 |
6410 | #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 |
6411 | #define SQLITE_DBSTATUS_CACHE_HIT 7 |
6412 | #define SQLITE_DBSTATUS_CACHE_MISS 8 |
6413 | #define SQLITE_DBSTATUS_CACHE_WRITE 9 |
6414 | #define SQLITE_DBSTATUS_DEFERRED_FKS 10 |
6415 | #define SQLITE_DBSTATUS_MAX 10 /* Largest defined DBSTATUS */ |
6416 | |
6417 | |
6418 | /* |
6419 | ** CAPI3REF: Prepared Statement Status |
6420 | ** |
6421 | ** ^(Each prepared statement maintains various |
6422 | ** [SQLITE_STMTSTATUS counters] that measure the number |
6423 | ** of times it has performed specific operations.)^ These counters can |
6424 | ** be used to monitor the performance characteristics of the prepared |
6425 | ** statements. For example, if the number of table steps greatly exceeds |
6426 | ** the number of table searches or result rows, that would tend to indicate |
6427 | ** that the prepared statement is using a full table scan rather than |
6428 | ** an index. |
6429 | ** |
6430 | ** ^(This interface is used to retrieve and reset counter values from |
6431 | ** a [prepared statement]. The first argument is the prepared statement |
6432 | ** object to be interrogated. The second argument |
6433 | ** is an integer code for a specific [SQLITE_STMTSTATUS counter] |
6434 | ** to be interrogated.)^ |
6435 | ** ^The current value of the requested counter is returned. |
6436 | ** ^If the resetFlg is true, then the counter is reset to zero after this |
6437 | ** interface call returns. |
6438 | ** |
6439 | ** See also: [sqlite3_status()] and [sqlite3_db_status()]. |
6440 | */ |
6441 | SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); |
6442 | |
6443 | /* |
6444 | ** CAPI3REF: Status Parameters for prepared statements |
6445 | ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} |
6446 | ** |
6447 | ** These preprocessor macros define integer codes that name counter |
6448 | ** values associated with the [sqlite3_stmt_status()] interface. |
6449 | ** The meanings of the various counters are as follows: |
6450 | ** |
6451 | ** <dl> |
6452 | ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> |
6453 | ** <dd>^This is the number of times that SQLite has stepped forward in |
6454 | ** a table as part of a full table scan. Large numbers for this counter |
6455 | ** may indicate opportunities for performance improvement through |
6456 | ** careful use of indices.</dd> |
6457 | ** |
6458 | ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> |
6459 | ** <dd>^This is the number of sort operations that have occurred. |
6460 | ** A non-zero value in this counter may indicate an opportunity to |
6461 | ** improvement performance through careful use of indices.</dd> |
6462 | ** |
6463 | ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> |
6464 | ** <dd>^This is the number of rows inserted into transient indices that |
6465 | ** were created automatically in order to help joins run faster. |
6466 | ** A non-zero value in this counter may indicate an opportunity to |
6467 | ** improvement performance by adding permanent indices that do not |
6468 | ** need to be reinitialized each time the statement is run.</dd> |
6469 | ** |
6470 | ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> |
6471 | ** <dd>^This is the number of virtual machine operations executed |
6472 | ** by the prepared statement if that number is less than or equal |
6473 | ** to 2147483647. The number of virtual machine operations can be |
6474 | ** used as a proxy for the total work done by the prepared statement. |
6475 | ** If the number of virtual machine operations exceeds 2147483647 |
6476 | ** then the value returned by this statement status code is undefined. |
6477 | ** </dd> |
6478 | ** </dl> |
6479 | */ |
6480 | #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 |
6481 | #define SQLITE_STMTSTATUS_SORT 2 |
6482 | #define SQLITE_STMTSTATUS_AUTOINDEX 3 |
6483 | #define SQLITE_STMTSTATUS_VM_STEP 4 |
6484 | |
6485 | /* |
6486 | ** CAPI3REF: Custom Page Cache Object |
6487 | ** |
6488 | ** The sqlite3_pcache type is opaque. It is implemented by |
6489 | ** the pluggable module. The SQLite core has no knowledge of |
6490 | ** its size or internal structure and never deals with the |
6491 | ** sqlite3_pcache object except by holding and passing pointers |
6492 | ** to the object. |
6493 | ** |
6494 | ** See [sqlite3_pcache_methods2] for additional information. |
6495 | */ |
6496 | typedef struct sqlite3_pcache sqlite3_pcache; |
6497 | |
6498 | /* |
6499 | ** CAPI3REF: Custom Page Cache Object |
6500 | ** |
6501 | ** The sqlite3_pcache_page object represents a single page in the |
6502 | ** page cache. The page cache will allocate instances of this |
6503 | ** object. Various methods of the page cache use pointers to instances |
6504 | ** of this object as parameters or as their return value. |
6505 | ** |
6506 | ** See [sqlite3_pcache_methods2] for additional information. |
6507 | */ |
6508 | typedef struct sqlite3_pcache_page sqlite3_pcache_page; |
6509 | struct sqlite3_pcache_page { |
6510 | void *pBuf; /* The content of the page */ |
6511 | void *pExtra; /* Extra information associated with the page */ |
6512 | }; |
6513 | |
6514 | /* |
6515 | ** CAPI3REF: Application Defined Page Cache. |
6516 | ** KEYWORDS: {page cache} |
6517 | ** |
6518 | ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can |
6519 | ** register an alternative page cache implementation by passing in an |
6520 | ** instance of the sqlite3_pcache_methods2 structure.)^ |
6521 | ** In many applications, most of the heap memory allocated by |
6522 | ** SQLite is used for the page cache. |
6523 | ** By implementing a |
6524 | ** custom page cache using this API, an application can better control |
6525 | ** the amount of memory consumed by SQLite, the way in which |
6526 | ** that memory is allocated and released, and the policies used to |
6527 | ** determine exactly which parts of a database file are cached and for |
6528 | ** how long. |
6529 | ** |
6530 | ** The alternative page cache mechanism is an |
6531 | ** extreme measure that is only needed by the most demanding applications. |
6532 | ** The built-in page cache is recommended for most uses. |
6533 | ** |
6534 | ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an |
6535 | ** internal buffer by SQLite within the call to [sqlite3_config]. Hence |
6536 | ** the application may discard the parameter after the call to |
6537 | ** [sqlite3_config()] returns.)^ |
6538 | ** |
6539 | ** [[the xInit() page cache method]] |
6540 | ** ^(The xInit() method is called once for each effective |
6541 | ** call to [sqlite3_initialize()])^ |
6542 | ** (usually only once during the lifetime of the process). ^(The xInit() |
6543 | ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ |
6544 | ** The intent of the xInit() method is to set up global data structures |
6545 | ** required by the custom page cache implementation. |
6546 | ** ^(If the xInit() method is NULL, then the |
6547 | ** built-in default page cache is used instead of the application defined |
6548 | ** page cache.)^ |
6549 | ** |
6550 | ** [[the xShutdown() page cache method]] |
6551 | ** ^The xShutdown() method is called by [sqlite3_shutdown()]. |
6552 | ** It can be used to clean up |
6553 | ** any outstanding resources before process shutdown, if required. |
6554 | ** ^The xShutdown() method may be NULL. |
6555 | ** |
6556 | ** ^SQLite automatically serializes calls to the xInit method, |
6557 | ** so the xInit method need not be threadsafe. ^The |
6558 | ** xShutdown method is only called from [sqlite3_shutdown()] so it does |
6559 | ** not need to be threadsafe either. All other methods must be threadsafe |
6560 | ** in multithreaded applications. |
6561 | ** |
6562 | ** ^SQLite will never invoke xInit() more than once without an intervening |
6563 | ** call to xShutdown(). |
6564 | ** |
6565 | ** [[the xCreate() page cache methods]] |
6566 | ** ^SQLite invokes the xCreate() method to construct a new cache instance. |
6567 | ** SQLite will typically create one cache instance for each open database file, |
6568 | ** though this is not guaranteed. ^The |
6569 | ** first parameter, szPage, is the size in bytes of the pages that must |
6570 | ** be allocated by the cache. ^szPage will always a power of two. ^The |
6571 | ** second parameter szExtra is a number of bytes of extra storage |
6572 | ** associated with each page cache entry. ^The szExtra parameter will |
6573 | ** a number less than 250. SQLite will use the |
6574 | ** extra szExtra bytes on each page to store metadata about the underlying |
6575 | ** database page on disk. The value passed into szExtra depends |
6576 | ** on the SQLite version, the target platform, and how SQLite was compiled. |
6577 | ** ^The third argument to xCreate(), bPurgeable, is true if the cache being |
6578 | ** created will be used to cache database pages of a file stored on disk, or |
6579 | ** false if it is used for an in-memory database. The cache implementation |
6580 | ** does not have to do anything special based with the value of bPurgeable; |
6581 | ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will |
6582 | ** never invoke xUnpin() except to deliberately delete a page. |
6583 | ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to |
6584 | ** false will always have the "discard" flag set to true. |
6585 | ** ^Hence, a cache created with bPurgeable false will |
6586 | ** never contain any unpinned pages. |
6587 | ** |
6588 | ** [[the xCachesize() page cache method]] |
6589 | ** ^(The xCachesize() method may be called at any time by SQLite to set the |
6590 | ** suggested maximum cache-size (number of pages stored by) the cache |
6591 | ** instance passed as the first argument. This is the value configured using |
6592 | ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable |
6593 | ** parameter, the implementation is not required to do anything with this |
6594 | ** value; it is advisory only. |
6595 | ** |
6596 | ** [[the xPagecount() page cache methods]] |
6597 | ** The xPagecount() method must return the number of pages currently |
6598 | ** stored in the cache, both pinned and unpinned. |
6599 | ** |
6600 | ** [[the xFetch() page cache methods]] |
6601 | ** The xFetch() method locates a page in the cache and returns a pointer to |
6602 | ** an sqlite3_pcache_page object associated with that page, or a NULL pointer. |
6603 | ** The pBuf element of the returned sqlite3_pcache_page object will be a |
6604 | ** pointer to a buffer of szPage bytes used to store the content of a |
6605 | ** single database page. The pExtra element of sqlite3_pcache_page will be |
6606 | ** a pointer to the szExtra bytes of extra storage that SQLite has requested |
6607 | ** for each entry in the page cache. |
6608 | ** |
6609 | ** The page to be fetched is determined by the key. ^The minimum key value |
6610 | ** is 1. After it has been retrieved using xFetch, the page is considered |
6611 | ** to be "pinned". |
6612 | ** |
6613 | ** If the requested page is already in the page cache, then the page cache |
6614 | ** implementation must return a pointer to the page buffer with its content |
6615 | ** intact. If the requested page is not already in the cache, then the |
6616 | ** cache implementation should use the value of the createFlag |
6617 | ** parameter to help it determined what action to take: |
6618 | ** |
6619 | ** <table border=1 width=85% align=center> |
6620 | ** <tr><th> createFlag <th> Behavior when page is not already in cache |
6621 | ** <tr><td> 0 <td> Do not allocate a new page. Return NULL. |
6622 | ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. |
6623 | ** Otherwise return NULL. |
6624 | ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return |
6625 | ** NULL if allocating a new page is effectively impossible. |
6626 | ** </table> |
6627 | ** |
6628 | ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite |
6629 | ** will only use a createFlag of 2 after a prior call with a createFlag of 1 |
6630 | ** failed.)^ In between the to xFetch() calls, SQLite may |
6631 | ** attempt to unpin one or more cache pages by spilling the content of |
6632 | ** pinned pages to disk and synching the operating system disk cache. |
6633 | ** |
6634 | ** [[the xUnpin() page cache method]] |
6635 | ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page |
6636 | ** as its second argument. If the third parameter, discard, is non-zero, |
6637 | ** then the page must be evicted from the cache. |
6638 | ** ^If the discard parameter is |
6639 | ** zero, then the page may be discarded or retained at the discretion of |
6640 | ** page cache implementation. ^The page cache implementation |
6641 | ** may choose to evict unpinned pages at any time. |
6642 | ** |
6643 | ** The cache must not perform any reference counting. A single |
6644 | ** call to xUnpin() unpins the page regardless of the number of prior calls |
6645 | ** to xFetch(). |
6646 | ** |
6647 | ** [[the xRekey() page cache methods]] |
6648 | ** The xRekey() method is used to change the key value associated with the |
6649 | ** page passed as the second argument. If the cache |
6650 | ** previously contains an entry associated with newKey, it must be |
6651 | ** discarded. ^Any prior cache entry associated with newKey is guaranteed not |
6652 | ** to be pinned. |
6653 | ** |
6654 | ** When SQLite calls the xTruncate() method, the cache must discard all |
6655 | ** existing cache entries with page numbers (keys) greater than or equal |
6656 | ** to the value of the iLimit parameter passed to xTruncate(). If any |
6657 | ** of these pages are pinned, they are implicitly unpinned, meaning that |
6658 | ** they can be safely discarded. |
6659 | ** |
6660 | ** [[the xDestroy() page cache method]] |
6661 | ** ^The xDestroy() method is used to delete a cache allocated by xCreate(). |
6662 | ** All resources associated with the specified cache should be freed. ^After |
6663 | ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] |
6664 | ** handle invalid, and will not use it with any other sqlite3_pcache_methods2 |
6665 | ** functions. |
6666 | ** |
6667 | ** [[the xShrink() page cache method]] |
6668 | ** ^SQLite invokes the xShrink() method when it wants the page cache to |
6669 | ** free up as much of heap memory as possible. The page cache implementation |
6670 | ** is not obligated to free any memory, but well-behaved implementations should |
6671 | ** do their best. |
6672 | */ |
6673 | typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; |
6674 | struct sqlite3_pcache_methods2 { |
6675 | int iVersion; |
6676 | void *pArg; |
6677 | int (*xInit)(void*); |
6678 | void (*xShutdown)(void*); |
6679 | sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); |
6680 | void (*xCachesize)(sqlite3_pcache*, int nCachesize); |
6681 | int (*xPagecount)(sqlite3_pcache*); |
6682 | sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); |
6683 | void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); |
6684 | void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, |
6685 | unsigned oldKey, unsigned newKey); |
6686 | void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); |
6687 | void (*xDestroy)(sqlite3_pcache*); |
6688 | void (*xShrink)(sqlite3_pcache*); |
6689 | }; |
6690 | |
6691 | /* |
6692 | ** This is the obsolete pcache_methods object that has now been replaced |
6693 | ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is |
6694 | ** retained in the header file for backwards compatibility only. |
6695 | */ |
6696 | typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; |
6697 | struct sqlite3_pcache_methods { |
6698 | void *pArg; |
6699 | int (*xInit)(void*); |
6700 | void (*xShutdown)(void*); |
6701 | sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); |
6702 | void (*xCachesize)(sqlite3_pcache*, int nCachesize); |
6703 | int (*xPagecount)(sqlite3_pcache*); |
6704 | void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); |
6705 | void (*xUnpin)(sqlite3_pcache*, void*, int discard); |
6706 | void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); |
6707 | void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); |
6708 | void (*xDestroy)(sqlite3_pcache*); |
6709 | }; |
6710 | |
6711 | |
6712 | /* |
6713 | ** CAPI3REF: Online Backup Object |
6714 | ** |
6715 | ** The sqlite3_backup object records state information about an ongoing |
6716 | ** online backup operation. ^The sqlite3_backup object is created by |
6717 | ** a call to [sqlite3_backup_init()] and is destroyed by a call to |
6718 | ** [sqlite3_backup_finish()]. |
6719 | ** |
6720 | ** See Also: [Using the SQLite Online Backup API] |
6721 | */ |
6722 | typedef struct sqlite3_backup sqlite3_backup; |
6723 | |
6724 | /* |
6725 | ** CAPI3REF: Online Backup API. |
6726 | ** |
6727 | ** The backup API copies the content of one database into another. |
6728 | ** It is useful either for creating backups of databases or |
6729 | ** for copying in-memory databases to or from persistent files. |
6730 | ** |
6731 | ** See Also: [Using the SQLite Online Backup API] |
6732 | ** |
6733 | ** ^SQLite holds a write transaction open on the destination database file |
6734 | ** for the duration of the backup operation. |
6735 | ** ^The source database is read-locked only while it is being read; |
6736 | ** it is not locked continuously for the entire backup operation. |
6737 | ** ^Thus, the backup may be performed on a live source database without |
6738 | ** preventing other database connections from |
6739 | ** reading or writing to the source database while the backup is underway. |
6740 | ** |
6741 | ** ^(To perform a backup operation: |
6742 | ** <ol> |
6743 | ** <li><b>sqlite3_backup_init()</b> is called once to initialize the |
6744 | ** backup, |
6745 | ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer |
6746 | ** the data between the two databases, and finally |
6747 | ** <li><b>sqlite3_backup_finish()</b> is called to release all resources |
6748 | ** associated with the backup operation. |
6749 | ** </ol>)^ |
6750 | ** There should be exactly one call to sqlite3_backup_finish() for each |
6751 | ** successful call to sqlite3_backup_init(). |
6752 | ** |
6753 | ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> |
6754 | ** |
6755 | ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the |
6756 | ** [database connection] associated with the destination database |
6757 | ** and the database name, respectively. |
6758 | ** ^The database name is "main" for the main database, "temp" for the |
6759 | ** temporary database, or the name specified after the AS keyword in |
6760 | ** an [ATTACH] statement for an attached database. |
6761 | ** ^The S and M arguments passed to |
6762 | ** sqlite3_backup_init(D,N,S,M) identify the [database connection] |
6763 | ** and database name of the source database, respectively. |
6764 | ** ^The source and destination [database connections] (parameters S and D) |
6765 | ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with |
6766 | ** an error. |
6767 | ** |
6768 | ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is |
6769 | ** returned and an error code and error message are stored in the |
6770 | ** destination [database connection] D. |
6771 | ** ^The error code and message for the failed call to sqlite3_backup_init() |
6772 | ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or |
6773 | ** [sqlite3_errmsg16()] functions. |
6774 | ** ^A successful call to sqlite3_backup_init() returns a pointer to an |
6775 | ** [sqlite3_backup] object. |
6776 | ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and |
6777 | ** sqlite3_backup_finish() functions to perform the specified backup |
6778 | ** operation. |
6779 | ** |
6780 | ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> |
6781 | ** |
6782 | ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between |
6783 | ** the source and destination databases specified by [sqlite3_backup] object B. |
6784 | ** ^If N is negative, all remaining source pages are copied. |
6785 | ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there |
6786 | ** are still more pages to be copied, then the function returns [SQLITE_OK]. |
6787 | ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages |
6788 | ** from source to destination, then it returns [SQLITE_DONE]. |
6789 | ** ^If an error occurs while running sqlite3_backup_step(B,N), |
6790 | ** then an [error code] is returned. ^As well as [SQLITE_OK] and |
6791 | ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], |
6792 | ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an |
6793 | ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. |
6794 | ** |
6795 | ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if |
6796 | ** <ol> |
6797 | ** <li> the destination database was opened read-only, or |
6798 | ** <li> the destination database is using write-ahead-log journaling |
6799 | ** and the destination and source page sizes differ, or |
6800 | ** <li> the destination database is an in-memory database and the |
6801 | ** destination and source page sizes differ. |
6802 | ** </ol>)^ |
6803 | ** |
6804 | ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then |
6805 | ** the [sqlite3_busy_handler | busy-handler function] |
6806 | ** is invoked (if one is specified). ^If the |
6807 | ** busy-handler returns non-zero before the lock is available, then |
6808 | ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to |
6809 | ** sqlite3_backup_step() can be retried later. ^If the source |
6810 | ** [database connection] |
6811 | ** is being used to write to the source database when sqlite3_backup_step() |
6812 | ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this |
6813 | ** case the call to sqlite3_backup_step() can be retried later on. ^(If |
6814 | ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or |
6815 | ** [SQLITE_READONLY] is returned, then |
6816 | ** there is no point in retrying the call to sqlite3_backup_step(). These |
6817 | ** errors are considered fatal.)^ The application must accept |
6818 | ** that the backup operation has failed and pass the backup operation handle |
6819 | ** to the sqlite3_backup_finish() to release associated resources. |
6820 | ** |
6821 | ** ^The first call to sqlite3_backup_step() obtains an exclusive lock |
6822 | ** on the destination file. ^The exclusive lock is not released until either |
6823 | ** sqlite3_backup_finish() is called or the backup operation is complete |
6824 | ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to |
6825 | ** sqlite3_backup_step() obtains a [shared lock] on the source database that |
6826 | ** lasts for the duration of the sqlite3_backup_step() call. |
6827 | ** ^Because the source database is not locked between calls to |
6828 | ** sqlite3_backup_step(), the source database may be modified mid-way |
6829 | ** through the backup process. ^If the source database is modified by an |
6830 | ** external process or via a database connection other than the one being |
6831 | ** used by the backup operation, then the backup will be automatically |
6832 | ** restarted by the next call to sqlite3_backup_step(). ^If the source |
6833 | ** database is modified by the using the same database connection as is used |
6834 | ** by the backup operation, then the backup database is automatically |
6835 | ** updated at the same time. |
6836 | ** |
6837 | ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> |
6838 | ** |
6839 | ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the |
6840 | ** application wishes to abandon the backup operation, the application |
6841 | ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). |
6842 | ** ^The sqlite3_backup_finish() interfaces releases all |
6843 | ** resources associated with the [sqlite3_backup] object. |
6844 | ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any |
6845 | ** active write-transaction on the destination database is rolled back. |
6846 | ** The [sqlite3_backup] object is invalid |
6847 | ** and may not be used following a call to sqlite3_backup_finish(). |
6848 | ** |
6849 | ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no |
6850 | ** sqlite3_backup_step() errors occurred, regardless or whether or not |
6851 | ** sqlite3_backup_step() completed. |
6852 | ** ^If an out-of-memory condition or IO error occurred during any prior |
6853 | ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then |
6854 | ** sqlite3_backup_finish() returns the corresponding [error code]. |
6855 | ** |
6856 | ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() |
6857 | ** is not a permanent error and does not affect the return value of |
6858 | ** sqlite3_backup_finish(). |
6859 | ** |
6860 | ** [[sqlite3_backup__remaining()]] [[sqlite3_backup_pagecount()]] |
6861 | ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> |
6862 | ** |
6863 | ** ^Each call to sqlite3_backup_step() sets two values inside |
6864 | ** the [sqlite3_backup] object: the number of pages still to be backed |
6865 | ** up and the total number of pages in the source database file. |
6866 | ** The sqlite3_backup_remaining() and sqlite3_backup_pagecount() interfaces |
6867 | ** retrieve these two values, respectively. |
6868 | ** |
6869 | ** ^The values returned by these functions are only updated by |
6870 | ** sqlite3_backup_step(). ^If the source database is modified during a backup |
6871 | ** operation, then the values are not updated to account for any extra |
6872 | ** pages that need to be updated or the size of the source database file |
6873 | ** changing. |
6874 | ** |
6875 | ** <b>Concurrent Usage of Database Handles</b> |
6876 | ** |
6877 | ** ^The source [database connection] may be used by the application for other |
6878 | ** purposes while a backup operation is underway or being initialized. |
6879 | ** ^If SQLite is compiled and configured to support threadsafe database |
6880 | ** connections, then the source database connection may be used concurrently |
6881 | ** from within other threads. |
6882 | ** |
6883 | ** However, the application must guarantee that the destination |
6884 | ** [database connection] is not passed to any other API (by any thread) after |
6885 | ** sqlite3_backup_init() is called and before the corresponding call to |
6886 | ** sqlite3_backup_finish(). SQLite does not currently check to see |
6887 | ** if the application incorrectly accesses the destination [database connection] |
6888 | ** and so no error code is reported, but the operations may malfunction |
6889 | ** nevertheless. Use of the destination database connection while a |
6890 | ** backup is in progress might also also cause a mutex deadlock. |
6891 | ** |
6892 | ** If running in [shared cache mode], the application must |
6893 | ** guarantee that the shared cache used by the destination database |
6894 | ** is not accessed while the backup is running. In practice this means |
6895 | ** that the application must guarantee that the disk file being |
6896 | ** backed up to is not accessed by any connection within the process, |
6897 | ** not just the specific connection that was passed to sqlite3_backup_init(). |
6898 | ** |
6899 | ** The [sqlite3_backup] object itself is partially threadsafe. Multiple |
6900 | ** threads may safely make multiple concurrent calls to sqlite3_backup_step(). |
6901 | ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() |
6902 | ** APIs are not strictly speaking threadsafe. If they are invoked at the |
6903 | ** same time as another thread is invoking sqlite3_backup_step() it is |
6904 | ** possible that they return invalid values. |
6905 | */ |
6906 | SQLITE_API sqlite3_backup *sqlite3_backup_init( |
6907 | sqlite3 *pDest, /* Destination database handle */ |
6908 | const char *zDestName, /* Destination database name */ |
6909 | sqlite3 *pSource, /* Source database handle */ |
6910 | const char *zSourceName /* Source database name */ |
6911 | ); |
6912 | SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage); |
6913 | SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p); |
6914 | SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p); |
6915 | SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p); |
6916 | |
6917 | /* |
6918 | ** CAPI3REF: Unlock Notification |
6919 | ** |
6920 | ** ^When running in shared-cache mode, a database operation may fail with |
6921 | ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or |
6922 | ** individual tables within the shared-cache cannot be obtained. See |
6923 | ** [SQLite Shared-Cache Mode] for a description of shared-cache locking. |
6924 | ** ^This API may be used to register a callback that SQLite will invoke |
6925 | ** when the connection currently holding the required lock relinquishes it. |
6926 | ** ^This API is only available if the library was compiled with the |
6927 | ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. |
6928 | ** |
6929 | ** See Also: [Using the SQLite Unlock Notification Feature]. |
6930 | ** |
6931 | ** ^Shared-cache locks are released when a database connection concludes |
6932 | ** its current transaction, either by committing it or rolling it back. |
6933 | ** |
6934 | ** ^When a connection (known as the blocked connection) fails to obtain a |
6935 | ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the |
6936 | ** identity of the database connection (the blocking connection) that |
6937 | ** has locked the required resource is stored internally. ^After an |
6938 | ** application receives an SQLITE_LOCKED error, it may call the |
6939 | ** sqlite3_unlock_notify() method with the blocked connection handle as |
6940 | ** the first argument to register for a callback that will be invoked |
6941 | ** when the blocking connections current transaction is concluded. ^The |
6942 | ** callback is invoked from within the [sqlite3_step] or [sqlite3_close] |
6943 | ** call that concludes the blocking connections transaction. |
6944 | ** |
6945 | ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, |
6946 | ** there is a chance that the blocking connection will have already |
6947 | ** concluded its transaction by the time sqlite3_unlock_notify() is invoked. |
6948 | ** If this happens, then the specified callback is invoked immediately, |
6949 | ** from within the call to sqlite3_unlock_notify().)^ |
6950 | ** |
6951 | ** ^If the blocked connection is attempting to obtain a write-lock on a |
6952 | ** shared-cache table, and more than one other connection currently holds |
6953 | ** a read-lock on the same table, then SQLite arbitrarily selects one of |
6954 | ** the other connections to use as the blocking connection. |
6955 | ** |
6956 | ** ^(There may be at most one unlock-notify callback registered by a |
6957 | ** blocked connection. If sqlite3_unlock_notify() is called when the |
6958 | ** blocked connection already has a registered unlock-notify callback, |
6959 | ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is |
6960 | ** called with a NULL pointer as its second argument, then any existing |
6961 | ** unlock-notify callback is canceled. ^The blocked connections |
6962 | ** unlock-notify callback may also be canceled by closing the blocked |
6963 | ** connection using [sqlite3_close()]. |
6964 | ** |
6965 | ** The unlock-notify callback is not reentrant. If an application invokes |
6966 | ** any sqlite3_xxx API functions from within an unlock-notify callback, a |
6967 | ** crash or deadlock may be the result. |
6968 | ** |
6969 | ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always |
6970 | ** returns SQLITE_OK. |
6971 | ** |
6972 | ** <b>Callback Invocation Details</b> |
6973 | ** |
6974 | ** When an unlock-notify callback is registered, the application provides a |
6975 | ** single void* pointer that is passed to the callback when it is invoked. |
6976 | ** However, the signature of the callback function allows SQLite to pass |
6977 | ** it an array of void* context pointers. The first argument passed to |
6978 | ** an unlock-notify callback is a pointer to an array of void* pointers, |
6979 | ** and the second is the number of entries in the array. |
6980 | ** |
6981 | ** When a blocking connections transaction is concluded, there may be |
6982 | ** more than one blocked connection that has registered for an unlock-notify |
6983 | ** callback. ^If two or more such blocked connections have specified the |
6984 | ** same callback function, then instead of invoking the callback function |
6985 | ** multiple times, it is invoked once with the set of void* context pointers |
6986 | ** specified by the blocked connections bundled together into an array. |
6987 | ** This gives the application an opportunity to prioritize any actions |
6988 | ** related to the set of unblocked database connections. |
6989 | ** |
6990 | ** <b>Deadlock Detection</b> |
6991 | ** |
6992 | ** Assuming that after registering for an unlock-notify callback a |
6993 | ** database waits for the callback to be issued before taking any further |
6994 | ** action (a reasonable assumption), then using this API may cause the |
6995 | ** application to deadlock. For example, if connection X is waiting for |
6996 | ** connection Y's transaction to be concluded, and similarly connection |
6997 | ** Y is waiting on connection X's transaction, then neither connection |
6998 | ** will proceed and the system may remain deadlocked indefinitely. |
6999 | ** |
7000 | ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock |
7001 | ** detection. ^If a given call to sqlite3_unlock_notify() would put the |
7002 | ** system in a deadlocked state, then SQLITE_LOCKED is returned and no |
7003 | ** unlock-notify callback is registered. The system is said to be in |
7004 | ** a deadlocked state if connection A has registered for an unlock-notify |
7005 | ** callback on the conclusion of connection B's transaction, and connection |
7006 | ** B has itself registered for an unlock-notify callback when connection |
7007 | ** A's transaction is concluded. ^Indirect deadlock is also detected, so |
7008 | ** the system is also considered to be deadlocked if connection B has |
7009 | ** registered for an unlock-notify callback on the conclusion of connection |
7010 | ** C's transaction, where connection C is waiting on connection A. ^Any |
7011 | ** number of levels of indirection are allowed. |
7012 | ** |
7013 | ** <b>The "DROP TABLE" Exception</b> |
7014 | ** |
7015 | ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost |
7016 | ** always appropriate to call sqlite3_unlock_notify(). There is however, |
7017 | ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, |
7018 | ** SQLite checks if there are any currently executing SELECT statements |
7019 | ** that belong to the same connection. If there are, SQLITE_LOCKED is |
7020 | ** returned. In this case there is no "blocking connection", so invoking |
7021 | ** sqlite3_unlock_notify() results in the unlock-notify callback being |
7022 | ** invoked immediately. If the application then re-attempts the "DROP TABLE" |
7023 | ** or "DROP INDEX" query, an infinite loop might be the result. |
7024 | ** |
7025 | ** One way around this problem is to check the extended error code returned |
7026 | ** by an sqlite3_step() call. ^(If there is a blocking connection, then the |
7027 | ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in |
7028 | ** the special "DROP TABLE/INDEX" case, the extended error code is just |
7029 | ** SQLITE_LOCKED.)^ |
7030 | */ |
7031 | SQLITE_API int sqlite3_unlock_notify( |
7032 | sqlite3 *pBlocked, /* Waiting connection */ |
7033 | void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ |
7034 | void *pNotifyArg /* Argument to pass to xNotify */ |
7035 | ); |
7036 | |
7037 | |
7038 | /* |
7039 | ** CAPI3REF: String Comparison |
7040 | ** |
7041 | ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications |
7042 | ** and extensions to compare the contents of two buffers containing UTF-8 |
7043 | ** strings in a case-independent fashion, using the same definition of "case |
7044 | ** independence" that SQLite uses internally when comparing identifiers. |
7045 | */ |
7046 | SQLITE_API int sqlite3_stricmp(const char *, const char *); |
7047 | SQLITE_API int sqlite3_strnicmp(const char *, const char *, int); |
7048 | |
7049 | /* |
7050 | ** CAPI3REF: String Globbing |
7051 | * |
7052 | ** ^The [sqlite3_strglob(P,X)] interface returns zero if string X matches |
7053 | ** the glob pattern P, and it returns non-zero if string X does not match |
7054 | ** the glob pattern P. ^The definition of glob pattern matching used in |
7055 | ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the |
7056 | ** SQL dialect used by SQLite. ^The sqlite3_strglob(P,X) function is case |
7057 | ** sensitive. |
7058 | ** |
7059 | ** Note that this routine returns zero on a match and non-zero if the strings |
7060 | ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. |
7061 | */ |
7062 | SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr); |
7063 | |
7064 | /* |
7065 | ** CAPI3REF: Error Logging Interface |
7066 | ** |
7067 | ** ^The [sqlite3_log()] interface writes a message into the [error log] |
7068 | ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. |
7069 | ** ^If logging is enabled, the zFormat string and subsequent arguments are |
7070 | ** used with [sqlite3_snprintf()] to generate the final output string. |
7071 | ** |
7072 | ** The sqlite3_log() interface is intended for use by extensions such as |
7073 | ** virtual tables, collating functions, and SQL functions. While there is |
7074 | ** nothing to prevent an application from calling sqlite3_log(), doing so |
7075 | ** is considered bad form. |
7076 | ** |
7077 | ** The zFormat string must not be NULL. |
7078 | ** |
7079 | ** To avoid deadlocks and other threading problems, the sqlite3_log() routine |
7080 | ** will not use dynamically allocated memory. The log message is stored in |
7081 | ** a fixed-length buffer on the stack. If the log message is longer than |
7082 | ** a few hundred characters, it will be truncated to the length of the |
7083 | ** buffer. |
7084 | */ |
7085 | SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...); |
7086 | |
7087 | /* |
7088 | ** CAPI3REF: Write-Ahead Log Commit Hook |
7089 | ** |
7090 | ** ^The [sqlite3_wal_hook()] function is used to register a callback that |
7091 | ** will be invoked each time a database connection commits data to a |
7092 | ** [write-ahead log] (i.e. whenever a transaction is committed in |
7093 | ** [journal_mode | journal_mode=WAL mode]). |
7094 | ** |
7095 | ** ^The callback is invoked by SQLite after the commit has taken place and |
7096 | ** the associated write-lock on the database released, so the implementation |
7097 | ** may read, write or [checkpoint] the database as required. |
7098 | ** |
7099 | ** ^The first parameter passed to the callback function when it is invoked |
7100 | ** is a copy of the third parameter passed to sqlite3_wal_hook() when |
7101 | ** registering the callback. ^The second is a copy of the database handle. |
7102 | ** ^The third parameter is the name of the database that was written to - |
7103 | ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter |
7104 | ** is the number of pages currently in the write-ahead log file, |
7105 | ** including those that were just committed. |
7106 | ** |
7107 | ** The callback function should normally return [SQLITE_OK]. ^If an error |
7108 | ** code is returned, that error will propagate back up through the |
7109 | ** SQLite code base to cause the statement that provoked the callback |
7110 | ** to report an error, though the commit will have still occurred. If the |
7111 | ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value |
7112 | ** that does not correspond to any valid SQLite error code, the results |
7113 | ** are undefined. |
7114 | ** |
7115 | ** A single database handle may have at most a single write-ahead log callback |
7116 | ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any |
7117 | ** previously registered write-ahead log callback. ^Note that the |
7118 | ** [sqlite3_wal_autocheckpoint()] interface and the |
7119 | ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will |
7120 | ** those overwrite any prior [sqlite3_wal_hook()] settings. |
7121 | */ |
7122 | SQLITE_API void *sqlite3_wal_hook( |
7123 | sqlite3*, |
7124 | int(*)(void *,sqlite3*,const char*,int), |
7125 | void* |
7126 | ); |
7127 | |
7128 | /* |
7129 | ** CAPI3REF: Configure an auto-checkpoint |
7130 | ** |
7131 | ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around |
7132 | ** [sqlite3_wal_hook()] that causes any database on [database connection] D |
7133 | ** to automatically [checkpoint] |
7134 | ** after committing a transaction if there are N or |
7135 | ** more frames in the [write-ahead log] file. ^Passing zero or |
7136 | ** a negative value as the nFrame parameter disables automatic |
7137 | ** checkpoints entirely. |
7138 | ** |
7139 | ** ^The callback registered by this function replaces any existing callback |
7140 | ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback |
7141 | ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism |
7142 | ** configured by this function. |
7143 | ** |
7144 | ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface |
7145 | ** from SQL. |
7146 | ** |
7147 | ** ^Every new [database connection] defaults to having the auto-checkpoint |
7148 | ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] |
7149 | ** pages. The use of this interface |
7150 | ** is only necessary if the default setting is found to be suboptimal |
7151 | ** for a particular application. |
7152 | */ |
7153 | SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); |
7154 | |
7155 | /* |
7156 | ** CAPI3REF: Checkpoint a database |
7157 | ** |
7158 | ** ^The [sqlite3_wal_checkpoint(D,X)] interface causes database named X |
7159 | ** on [database connection] D to be [checkpointed]. ^If X is NULL or an |
7160 | ** empty string, then a checkpoint is run on all databases of |
7161 | ** connection D. ^If the database connection D is not in |
7162 | ** [WAL | write-ahead log mode] then this interface is a harmless no-op. |
7163 | ** |
7164 | ** ^The [wal_checkpoint pragma] can be used to invoke this interface |
7165 | ** from SQL. ^The [sqlite3_wal_autocheckpoint()] interface and the |
7166 | ** [wal_autocheckpoint pragma] can be used to cause this interface to be |
7167 | ** run whenever the WAL reaches a certain size threshold. |
7168 | ** |
7169 | ** See also: [sqlite3_wal_checkpoint_v2()] |
7170 | */ |
7171 | SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); |
7172 | |
7173 | /* |
7174 | ** CAPI3REF: Checkpoint a database |
7175 | ** |
7176 | ** Run a checkpoint operation on WAL database zDb attached to database |
7177 | ** handle db. The specific operation is determined by the value of the |
7178 | ** eMode parameter: |
7179 | ** |
7180 | ** <dl> |
7181 | ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> |
7182 | ** Checkpoint as many frames as possible without waiting for any database |
7183 | ** readers or writers to finish. Sync the db file if all frames in the log |
7184 | ** are checkpointed. This mode is the same as calling |
7185 | ** sqlite3_wal_checkpoint(). The busy-handler callback is never invoked. |
7186 | ** |
7187 | ** <dt>SQLITE_CHECKPOINT_FULL<dd> |
7188 | ** This mode blocks (calls the busy-handler callback) until there is no |
7189 | ** database writer and all readers are reading from the most recent database |
7190 | ** snapshot. It then checkpoints all frames in the log file and syncs the |
7191 | ** database file. This call blocks database writers while it is running, |
7192 | ** but not database readers. |
7193 | ** |
7194 | ** <dt>SQLITE_CHECKPOINT_RESTART<dd> |
7195 | ** This mode works the same way as SQLITE_CHECKPOINT_FULL, except after |
7196 | ** checkpointing the log file it blocks (calls the busy-handler callback) |
7197 | ** until all readers are reading from the database file only. This ensures |
7198 | ** that the next client to write to the database file restarts the log file |
7199 | ** from the beginning. This call blocks database writers while it is running, |
7200 | ** but not database readers. |
7201 | ** </dl> |
7202 | ** |
7203 | ** If pnLog is not NULL, then *pnLog is set to the total number of frames in |
7204 | ** the log file before returning. If pnCkpt is not NULL, then *pnCkpt is set to |
7205 | ** the total number of checkpointed frames (including any that were already |
7206 | ** checkpointed when this function is called). *pnLog and *pnCkpt may be |
7207 | ** populated even if sqlite3_wal_checkpoint_v2() returns other than SQLITE_OK. |
7208 | ** If no values are available because of an error, they are both set to -1 |
7209 | ** before returning to communicate this to the caller. |
7210 | ** |
7211 | ** All calls obtain an exclusive "checkpoint" lock on the database file. If |
7212 | ** any other process is running a checkpoint operation at the same time, the |
7213 | ** lock cannot be obtained and SQLITE_BUSY is returned. Even if there is a |
7214 | ** busy-handler configured, it will not be invoked in this case. |
7215 | ** |
7216 | ** The SQLITE_CHECKPOINT_FULL and RESTART modes also obtain the exclusive |
7217 | ** "writer" lock on the database file. If the writer lock cannot be obtained |
7218 | ** immediately, and a busy-handler is configured, it is invoked and the writer |
7219 | ** lock retried until either the busy-handler returns 0 or the lock is |
7220 | ** successfully obtained. The busy-handler is also invoked while waiting for |
7221 | ** database readers as described above. If the busy-handler returns 0 before |
7222 | ** the writer lock is obtained or while waiting for database readers, the |
7223 | ** checkpoint operation proceeds from that point in the same way as |
7224 | ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible |
7225 | ** without blocking any further. SQLITE_BUSY is returned in this case. |
7226 | ** |
7227 | ** If parameter zDb is NULL or points to a zero length string, then the |
7228 | ** specified operation is attempted on all WAL databases. In this case the |
7229 | ** values written to output parameters *pnLog and *pnCkpt are undefined. If |
7230 | ** an SQLITE_BUSY error is encountered when processing one or more of the |
7231 | ** attached WAL databases, the operation is still attempted on any remaining |
7232 | ** attached databases and SQLITE_BUSY is returned to the caller. If any other |
7233 | ** error occurs while processing an attached database, processing is abandoned |
7234 | ** and the error code returned to the caller immediately. If no error |
7235 | ** (SQLITE_BUSY or otherwise) is encountered while processing the attached |
7236 | ** databases, SQLITE_OK is returned. |
7237 | ** |
7238 | ** If database zDb is the name of an attached database that is not in WAL |
7239 | ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. If |
7240 | ** zDb is not NULL (or a zero length string) and is not the name of any |
7241 | ** attached database, SQLITE_ERROR is returned to the caller. |
7242 | */ |
7243 | SQLITE_API int sqlite3_wal_checkpoint_v2( |
7244 | sqlite3 *db, /* Database handle */ |
7245 | const char *zDb, /* Name of attached database (or NULL) */ |
7246 | int eMode, /* SQLITE_CHECKPOINT_* value */ |
7247 | int *pnLog, /* OUT: Size of WAL log in frames */ |
7248 | int *pnCkpt /* OUT: Total number of frames checkpointed */ |
7249 | ); |
7250 | |
7251 | /* |
7252 | ** CAPI3REF: Checkpoint operation parameters |
7253 | ** |
7254 | ** These constants can be used as the 3rd parameter to |
7255 | ** [sqlite3_wal_checkpoint_v2()]. See the [sqlite3_wal_checkpoint_v2()] |
7256 | ** documentation for additional information about the meaning and use of |
7257 | ** each of these values. |
7258 | */ |
7259 | #define SQLITE_CHECKPOINT_PASSIVE 0 |
7260 | #define SQLITE_CHECKPOINT_FULL 1 |
7261 | #define SQLITE_CHECKPOINT_RESTART 2 |
7262 | |
7263 | /* |
7264 | ** CAPI3REF: Virtual Table Interface Configuration |
7265 | ** |
7266 | ** This function may be called by either the [xConnect] or [xCreate] method |
7267 | ** of a [virtual table] implementation to configure |
7268 | ** various facets of the virtual table interface. |
7269 | ** |
7270 | ** If this interface is invoked outside the context of an xConnect or |
7271 | ** xCreate virtual table method then the behavior is undefined. |
7272 | ** |
7273 | ** At present, there is only one option that may be configured using |
7274 | ** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options |
7275 | ** may be added in the future. |
7276 | */ |
7277 | SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...); |
7278 | |
7279 | /* |
7280 | ** CAPI3REF: Virtual Table Configuration Options |
7281 | ** |
7282 | ** These macros define the various options to the |
7283 | ** [sqlite3_vtab_config()] interface that [virtual table] implementations |
7284 | ** can use to customize and optimize their behavior. |
7285 | ** |
7286 | ** <dl> |
7287 | ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT |
7288 | ** <dd>Calls of the form |
7289 | ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, |
7290 | ** where X is an integer. If X is zero, then the [virtual table] whose |
7291 | ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not |
7292 | ** support constraints. In this configuration (which is the default) if |
7293 | ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire |
7294 | ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been |
7295 | ** specified as part of the users SQL statement, regardless of the actual |
7296 | ** ON CONFLICT mode specified. |
7297 | ** |
7298 | ** If X is non-zero, then the virtual table implementation guarantees |
7299 | ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before |
7300 | ** any modifications to internal or persistent data structures have been made. |
7301 | ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite |
7302 | ** is able to roll back a statement or database transaction, and abandon |
7303 | ** or continue processing the current SQL statement as appropriate. |
7304 | ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns |
7305 | ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode |
7306 | ** had been ABORT. |
7307 | ** |
7308 | ** Virtual table implementations that are required to handle OR REPLACE |
7309 | ** must do so within the [xUpdate] method. If a call to the |
7310 | ** [sqlite3_vtab_on_conflict()] function indicates that the current ON |
7311 | ** CONFLICT policy is REPLACE, the virtual table implementation should |
7312 | ** silently replace the appropriate rows within the xUpdate callback and |
7313 | ** return SQLITE_OK. Or, if this is not possible, it may return |
7314 | ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT |
7315 | ** constraint handling. |
7316 | ** </dl> |
7317 | */ |
7318 | #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 |
7319 | |
7320 | /* |
7321 | ** CAPI3REF: Determine The Virtual Table Conflict Policy |
7322 | ** |
7323 | ** This function may only be called from within a call to the [xUpdate] method |
7324 | ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The |
7325 | ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], |
7326 | ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode |
7327 | ** of the SQL statement that triggered the call to the [xUpdate] method of the |
7328 | ** [virtual table]. |
7329 | */ |
7330 | SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *); |
7331 | |
7332 | /* |
7333 | ** CAPI3REF: Conflict resolution modes |
7334 | ** |
7335 | ** These constants are returned by [sqlite3_vtab_on_conflict()] to |
7336 | ** inform a [virtual table] implementation what the [ON CONFLICT] mode |
7337 | ** is for the SQL statement being evaluated. |
7338 | ** |
7339 | ** Note that the [SQLITE_IGNORE] constant is also used as a potential |
7340 | ** return value from the [sqlite3_set_authorizer()] callback and that |
7341 | ** [SQLITE_ABORT] is also a [result code]. |
7342 | */ |
7343 | #define SQLITE_ROLLBACK 1 |
7344 | /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ |
7345 | #define SQLITE_FAIL 3 |
7346 | /* #define SQLITE_ABORT 4 // Also an error code */ |
7347 | #define SQLITE_REPLACE 5 |
7348 | |
7349 | |
7350 | |
7351 | /* |
7352 | ** Undo the hack that converts floating point types to integer for |
7353 | ** builds on processors without floating point support. |
7354 | */ |
7355 | #ifdef SQLITE_OMIT_FLOATING_POINT |
7356 | # undef double |
7357 | #endif |
7358 | |
7359 | #ifdef __cplusplus |
7360 | } /* End of the 'extern "C"' block */ |
7361 | #endif |
7362 | #endif /* _SQLITE3_H_ */ |
7363 | |
7364 | /* |
7365 | ** 2010 August 30 |
7366 | ** |
7367 | ** The author disclaims copyright to this source code. In place of |
7368 | ** a legal notice, here is a blessing: |
7369 | ** |
7370 | ** May you do good and not evil. |
7371 | ** May you find forgiveness for yourself and forgive others. |
7372 | ** May you share freely, never taking more than you give. |
7373 | ** |
7374 | ************************************************************************* |
7375 | */ |
7376 | |
7377 | #ifndef _SQLITE3RTREE_H_ |
7378 | #define _SQLITE3RTREE_H_ |
7379 | |
7380 | |
7381 | #ifdef __cplusplus |
7382 | extern "C"{ |
7383 | #endif |
7384 | |
7385 | typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; |
7386 | typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info; |
7387 | |
7388 | /* The double-precision datatype used by RTree depends on the |
7389 | ** SQLITE_RTREE_INT_ONLY compile-time option. |
7390 | */ |
7391 | #ifdef SQLITE_RTREE_INT_ONLY |
7392 | typedef sqlite3_int64 sqlite3_rtree_dbl; |
7393 | #else |
7394 | typedef double sqlite3_rtree_dbl; |
7395 | #endif |
7396 | |
7397 | /* |
7398 | ** Register a geometry callback named zGeom that can be used as part of an |
7399 | ** R-Tree geometry query as follows: |
7400 | ** |
7401 | ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) |
7402 | */ |
7403 | SQLITE_API int sqlite3_rtree_geometry_callback( |
7404 | sqlite3 *db, |
7405 | const char *zGeom, |
7406 | int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*), |
7407 | void *pContext |
7408 | ); |
7409 | |
7410 | |
7411 | /* |
7412 | ** A pointer to a structure of the following type is passed as the first |
7413 | ** argument to callbacks registered using rtree_geometry_callback(). |
7414 | */ |
7415 | struct sqlite3_rtree_geometry { |
7416 | void *pContext; /* Copy of pContext passed to s_r_g_c() */ |
7417 | int nParam; /* Size of array aParam[] */ |
7418 | sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */ |
7419 | void *pUser; /* Callback implementation user data */ |
7420 | void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ |
7421 | }; |
7422 | |
7423 | /* |
7424 | ** Register a 2nd-generation geometry callback named zScore that can be |
7425 | ** used as part of an R-Tree geometry query as follows: |
7426 | ** |
7427 | ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...) |
7428 | */ |
7429 | SQLITE_API int sqlite3_rtree_query_callback( |
7430 | sqlite3 *db, |
7431 | const char *zQueryFunc, |
7432 | int (*xQueryFunc)(sqlite3_rtree_query_info*), |
7433 | void *pContext, |
7434 | void (*xDestructor)(void*) |
7435 | ); |
7436 | |
7437 | |
7438 | /* |
7439 | ** A pointer to a structure of the following type is passed as the |
7440 | ** argument to scored geometry callback registered using |
7441 | ** sqlite3_rtree_query_callback(). |
7442 | ** |
7443 | ** Note that the first 5 fields of this structure are identical to |
7444 | ** sqlite3_rtree_geometry. This structure is a subclass of |
7445 | ** sqlite3_rtree_geometry. |
7446 | */ |
7447 | struct sqlite3_rtree_query_info { |
7448 | void *pContext; /* pContext from when function registered */ |
7449 | int nParam; /* Number of function parameters */ |
7450 | sqlite3_rtree_dbl *aParam; /* value of function parameters */ |
7451 | void *pUser; /* callback can use this, if desired */ |
7452 | void (*xDelUser)(void*); /* function to free pUser */ |
7453 | sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */ |
7454 | unsigned int *anQueue; /* Number of pending entries in the queue */ |
7455 | int nCoord; /* Number of coordinates */ |
7456 | int iLevel; /* Level of current node or entry */ |
7457 | int mxLevel; /* The largest iLevel value in the tree */ |
7458 | sqlite3_int64 iRowid; /* Rowid for current entry */ |
7459 | sqlite3_rtree_dbl rParentScore; /* Score of parent node */ |
7460 | int eParentWithin; /* Visibility of parent node */ |
7461 | int eWithin; /* OUT: Visiblity */ |
7462 | sqlite3_rtree_dbl rScore; /* OUT: Write the score here */ |
7463 | }; |
7464 | |
7465 | /* |
7466 | ** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin. |
7467 | */ |
7468 | #define NOT_WITHIN 0 /* Object completely outside of query region */ |
7469 | #define PARTLY_WITHIN 1 /* Object partially overlaps query region */ |
7470 | #define FULLY_WITHIN 2 /* Object fully contained within query region */ |
7471 | |
7472 | |
7473 | #ifdef __cplusplus |
7474 | } /* end of the 'extern "C"' block */ |
7475 | #endif |
7476 | |
7477 | #endif /* ifndef _SQLITE3RTREE_H_ */ |
7478 | |
7479 |
Warning: That file was not part of the compilation database. It may have many parsing errors.