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5783a860 AC |
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 | |
4094d2fa | 20 | ** features recently added to SQLite. We do not anticipate changes |
08b809f9 EM |
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. | |
5783a860 AC |
23 | ** |
24 | ** The official C-language API documentation for SQLite is derived | |
25 | ** from comments in this file. This file is the authoritative source | |
08b809f9 | 26 | ** on how SQLite interfaces are supposed to operate. |
5783a860 AC |
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. | |
5783a860 AC |
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 | /* | |
08b809f9 | 46 | ** Provide the ability to override linkage features of the interface. |
5783a860 AC |
47 | */ |
48 | #ifndef SQLITE_EXTERN | |
49 | # define SQLITE_EXTERN extern | |
50 | #endif | |
08b809f9 EM |
51 | #ifndef SQLITE_API |
52 | # define SQLITE_API | |
53 | #endif | |
54 | #ifndef SQLITE_CDECL | |
55 | # define SQLITE_CDECL | |
56 | #endif | |
57 | #ifndef SQLITE_STDCALL | |
58 | # define SQLITE_STDCALL | |
59 | #endif | |
5783a860 AC |
60 | |
61 | /* | |
08b809f9 EM |
62 | ** These no-op macros are used in front of interfaces to mark those |
63 | ** interfaces as either deprecated or experimental. New applications | |
64 | ** should not use deprecated interfaces - they are supported for backwards | |
65 | ** compatibility only. Application writers should be aware that | |
66 | ** experimental interfaces are subject to change in point releases. | |
67 | ** | |
68 | ** These macros used to resolve to various kinds of compiler magic that | |
69 | ** would generate warning messages when they were used. But that | |
70 | ** compiler magic ended up generating such a flurry of bug reports | |
71 | ** that we have taken it all out and gone back to using simple | |
72 | ** noop macros. | |
73 | */ | |
74 | #define SQLITE_DEPRECATED | |
75 | #define SQLITE_EXPERIMENTAL | |
76 | ||
77 | /* | |
78 | ** Ensure these symbols were not defined by some previous header file. | |
5783a860 AC |
79 | */ |
80 | #ifdef SQLITE_VERSION | |
81 | # undef SQLITE_VERSION | |
82 | #endif | |
83 | #ifdef SQLITE_VERSION_NUMBER | |
84 | # undef SQLITE_VERSION_NUMBER | |
85 | #endif | |
86 | ||
87 | /* | |
08b809f9 EM |
88 | ** CAPI3REF: Compile-Time Library Version Numbers |
89 | ** | |
90 | ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header | |
91 | ** evaluates to a string literal that is the SQLite version in the | |
92 | ** format "X.Y.Z" where X is the major version number (always 3 for | |
93 | ** SQLite3) and Y is the minor version number and Z is the release number.)^ | |
94 | ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer | |
95 | ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same | |
96 | ** numbers used in [SQLITE_VERSION].)^ | |
97 | ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also | |
98 | ** be larger than the release from which it is derived. Either Y will | |
99 | ** be held constant and Z will be incremented or else Y will be incremented | |
100 | ** and Z will be reset to zero. | |
101 | ** | |
102 | ** Since version 3.6.18, SQLite source code has been stored in the | |
103 | ** <a href="http://www.fossil-scm.org/">Fossil configuration management | |
104 | ** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to | |
105 | ** a string which identifies a particular check-in of SQLite | |
106 | ** within its configuration management system. ^The SQLITE_SOURCE_ID | |
107 | ** string contains the date and time of the check-in (UTC) and an SHA1 | |
108 | ** hash of the entire source tree. | |
109 | ** | |
110 | ** See also: [sqlite3_libversion()], | |
111 | ** [sqlite3_libversion_number()], [sqlite3_sourceid()], | |
112 | ** [sqlite_version()] and [sqlite_source_id()]. | |
5783a860 | 113 | */ |
08b809f9 EM |
114 | #define SQLITE_VERSION "3.12.0" |
115 | #define SQLITE_VERSION_NUMBER 3012000 | |
116 | #define SQLITE_SOURCE_ID "2016-03-29 10:14:15 e9bb4cf40f4971974a74468ef922bdee481c988b" | |
5783a860 AC |
117 | |
118 | /* | |
08b809f9 EM |
119 | ** CAPI3REF: Run-Time Library Version Numbers |
120 | ** KEYWORDS: sqlite3_version, sqlite3_sourceid | |
5783a860 | 121 | ** |
08b809f9 EM |
122 | ** These interfaces provide the same information as the [SQLITE_VERSION], |
123 | ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros | |
124 | ** but are associated with the library instead of the header file. ^(Cautious | |
125 | ** programmers might include assert() statements in their application to | |
126 | ** verify that values returned by these interfaces match the macros in | |
127 | ** the header, and thus ensure that the application is | |
128 | ** compiled with matching library and header files. | |
5783a860 | 129 | ** |
08b809f9 EM |
130 | ** <blockquote><pre> |
131 | ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); | |
132 | ** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 ); | |
133 | ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); | |
134 | ** </pre></blockquote>)^ | |
135 | ** | |
136 | ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] | |
137 | ** macro. ^The sqlite3_libversion() function returns a pointer to the | |
138 | ** to the sqlite3_version[] string constant. The sqlite3_libversion() | |
139 | ** function is provided for use in DLLs since DLL users usually do not have | |
140 | ** direct access to string constants within the DLL. ^The | |
141 | ** sqlite3_libversion_number() function returns an integer equal to | |
142 | ** [SQLITE_VERSION_NUMBER]. ^The sqlite3_sourceid() function returns | |
143 | ** a pointer to a string constant whose value is the same as the | |
144 | ** [SQLITE_SOURCE_ID] C preprocessor macro. | |
145 | ** | |
146 | ** See also: [sqlite_version()] and [sqlite_source_id()]. | |
147 | */ | |
148 | SQLITE_API SQLITE_EXTERN const char sqlite3_version[]; | |
149 | SQLITE_API const char *SQLITE_STDCALL sqlite3_libversion(void); | |
150 | SQLITE_API const char *SQLITE_STDCALL sqlite3_sourceid(void); | |
151 | SQLITE_API int SQLITE_STDCALL sqlite3_libversion_number(void); | |
152 | ||
153 | /* | |
154 | ** CAPI3REF: Run-Time Library Compilation Options Diagnostics | |
155 | ** | |
156 | ** ^The sqlite3_compileoption_used() function returns 0 or 1 | |
157 | ** indicating whether the specified option was defined at | |
158 | ** compile time. ^The SQLITE_ prefix may be omitted from the | |
159 | ** option name passed to sqlite3_compileoption_used(). | |
160 | ** | |
161 | ** ^The sqlite3_compileoption_get() function allows iterating | |
162 | ** over the list of options that were defined at compile time by | |
163 | ** returning the N-th compile time option string. ^If N is out of range, | |
164 | ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ | |
165 | ** prefix is omitted from any strings returned by | |
166 | ** sqlite3_compileoption_get(). | |
167 | ** | |
168 | ** ^Support for the diagnostic functions sqlite3_compileoption_used() | |
169 | ** and sqlite3_compileoption_get() may be omitted by specifying the | |
170 | ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. | |
171 | ** | |
172 | ** See also: SQL functions [sqlite_compileoption_used()] and | |
173 | ** [sqlite_compileoption_get()] and the [compile_options pragma]. | |
5783a860 | 174 | */ |
08b809f9 EM |
175 | #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS |
176 | SQLITE_API int SQLITE_STDCALL sqlite3_compileoption_used(const char *zOptName); | |
177 | SQLITE_API const char *SQLITE_STDCALL sqlite3_compileoption_get(int N); | |
178 | #endif | |
5783a860 AC |
179 | |
180 | /* | |
08b809f9 EM |
181 | ** CAPI3REF: Test To See If The Library Is Threadsafe |
182 | ** | |
183 | ** ^The sqlite3_threadsafe() function returns zero if and only if | |
184 | ** SQLite was compiled with mutexing code omitted due to the | |
185 | ** [SQLITE_THREADSAFE] compile-time option being set to 0. | |
5783a860 AC |
186 | ** |
187 | ** SQLite can be compiled with or without mutexes. When | |
08b809f9 EM |
188 | ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes |
189 | ** are enabled and SQLite is threadsafe. When the | |
190 | ** [SQLITE_THREADSAFE] macro is 0, | |
5783a860 | 191 | ** the mutexes are omitted. Without the mutexes, it is not safe |
08b809f9 | 192 | ** to use SQLite concurrently from more than one thread. |
5783a860 | 193 | ** |
08b809f9 | 194 | ** Enabling mutexes incurs a measurable performance penalty. |
5783a860 AC |
195 | ** So if speed is of utmost importance, it makes sense to disable |
196 | ** the mutexes. But for maximum safety, mutexes should be enabled. | |
08b809f9 | 197 | ** ^The default behavior is for mutexes to be enabled. |
5783a860 | 198 | ** |
08b809f9 | 199 | ** This interface can be used by an application to make sure that the |
5783a860 | 200 | ** version of SQLite that it is linking against was compiled with |
08b809f9 EM |
201 | ** the desired setting of the [SQLITE_THREADSAFE] macro. |
202 | ** | |
203 | ** This interface only reports on the compile-time mutex setting | |
204 | ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with | |
205 | ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but | |
206 | ** can be fully or partially disabled using a call to [sqlite3_config()] | |
207 | ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], | |
208 | ** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the | |
209 | ** sqlite3_threadsafe() function shows only the compile-time setting of | |
210 | ** thread safety, not any run-time changes to that setting made by | |
211 | ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() | |
212 | ** is unchanged by calls to sqlite3_config().)^ | |
213 | ** | |
214 | ** See the [threading mode] documentation for additional information. | |
5783a860 | 215 | */ |
08b809f9 | 216 | SQLITE_API int SQLITE_STDCALL sqlite3_threadsafe(void); |
5783a860 AC |
217 | |
218 | /* | |
08b809f9 | 219 | ** CAPI3REF: Database Connection Handle |
5783a860 AC |
220 | ** KEYWORDS: {database connection} {database connections} |
221 | ** | |
08b809f9 EM |
222 | ** Each open SQLite database is represented by a pointer to an instance of |
223 | ** the opaque structure named "sqlite3". It is useful to think of an sqlite3 | |
5783a860 | 224 | ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and |
08b809f9 EM |
225 | ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] |
226 | ** and [sqlite3_close_v2()] are its destructors. There are many other | |
227 | ** interfaces (such as | |
228 | ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and | |
229 | ** [sqlite3_busy_timeout()] to name but three) that are methods on an | |
230 | ** sqlite3 object. | |
5783a860 AC |
231 | */ |
232 | typedef struct sqlite3 sqlite3; | |
233 | ||
5783a860 | 234 | /* |
08b809f9 | 235 | ** CAPI3REF: 64-Bit Integer Types |
5783a860 AC |
236 | ** KEYWORDS: sqlite_int64 sqlite_uint64 |
237 | ** | |
238 | ** Because there is no cross-platform way to specify 64-bit integer types | |
239 | ** SQLite includes typedefs for 64-bit signed and unsigned integers. | |
240 | ** | |
08b809f9 EM |
241 | ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. |
242 | ** The sqlite_int64 and sqlite_uint64 types are supported for backwards | |
243 | ** compatibility only. | |
5783a860 | 244 | ** |
08b809f9 EM |
245 | ** ^The sqlite3_int64 and sqlite_int64 types can store integer values |
246 | ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The | |
247 | ** sqlite3_uint64 and sqlite_uint64 types can store integer values | |
248 | ** between 0 and +18446744073709551615 inclusive. | |
5783a860 AC |
249 | */ |
250 | #ifdef SQLITE_INT64_TYPE | |
251 | typedef SQLITE_INT64_TYPE sqlite_int64; | |
252 | typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; | |
253 | #elif defined(_MSC_VER) || defined(__BORLANDC__) | |
254 | typedef __int64 sqlite_int64; | |
255 | typedef unsigned __int64 sqlite_uint64; | |
256 | #else | |
257 | typedef long long int sqlite_int64; | |
258 | typedef unsigned long long int sqlite_uint64; | |
259 | #endif | |
260 | typedef sqlite_int64 sqlite3_int64; | |
261 | typedef sqlite_uint64 sqlite3_uint64; | |
262 | ||
263 | /* | |
264 | ** If compiling for a processor that lacks floating point support, | |
08b809f9 | 265 | ** substitute integer for floating-point. |
5783a860 AC |
266 | */ |
267 | #ifdef SQLITE_OMIT_FLOATING_POINT | |
268 | # define double sqlite3_int64 | |
269 | #endif | |
270 | ||
271 | /* | |
08b809f9 EM |
272 | ** CAPI3REF: Closing A Database Connection |
273 | ** DESTRUCTOR: sqlite3 | |
274 | ** | |
275 | ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors | |
276 | ** for the [sqlite3] object. | |
277 | ** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if | |
278 | ** the [sqlite3] object is successfully destroyed and all associated | |
279 | ** resources are deallocated. | |
280 | ** | |
281 | ** ^If the database connection is associated with unfinalized prepared | |
282 | ** statements or unfinished sqlite3_backup objects then sqlite3_close() | |
283 | ** will leave the database connection open and return [SQLITE_BUSY]. | |
284 | ** ^If sqlite3_close_v2() is called with unfinalized prepared statements | |
285 | ** and/or unfinished sqlite3_backups, then the database connection becomes | |
286 | ** an unusable "zombie" which will automatically be deallocated when the | |
287 | ** last prepared statement is finalized or the last sqlite3_backup is | |
288 | ** finished. The sqlite3_close_v2() interface is intended for use with | |
289 | ** host languages that are garbage collected, and where the order in which | |
290 | ** destructors are called is arbitrary. | |
291 | ** | |
292 | ** Applications should [sqlite3_finalize | finalize] all [prepared statements], | |
293 | ** [sqlite3_blob_close | close] all [BLOB handles], and | |
294 | ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated | |
295 | ** with the [sqlite3] object prior to attempting to close the object. ^If | |
296 | ** sqlite3_close_v2() is called on a [database connection] that still has | |
297 | ** outstanding [prepared statements], [BLOB handles], and/or | |
298 | ** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation | |
299 | ** of resources is deferred until all [prepared statements], [BLOB handles], | |
300 | ** and [sqlite3_backup] objects are also destroyed. | |
301 | ** | |
302 | ** ^If an [sqlite3] object is destroyed while a transaction is open, | |
303 | ** the transaction is automatically rolled back. | |
304 | ** | |
305 | ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] | |
306 | ** must be either a NULL | |
307 | ** pointer or an [sqlite3] object pointer obtained | |
308 | ** from [sqlite3_open()], [sqlite3_open16()], or | |
309 | ** [sqlite3_open_v2()], and not previously closed. | |
310 | ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer | |
311 | ** argument is a harmless no-op. | |
5783a860 | 312 | */ |
08b809f9 EM |
313 | SQLITE_API int SQLITE_STDCALL sqlite3_close(sqlite3*); |
314 | SQLITE_API int SQLITE_STDCALL sqlite3_close_v2(sqlite3*); | |
5783a860 AC |
315 | |
316 | /* | |
317 | ** The type for a callback function. | |
318 | ** This is legacy and deprecated. It is included for historical | |
319 | ** compatibility and is not documented. | |
320 | */ | |
321 | typedef int (*sqlite3_callback)(void*,int,char**, char**); | |
322 | ||
323 | /* | |
08b809f9 EM |
324 | ** CAPI3REF: One-Step Query Execution Interface |
325 | ** METHOD: sqlite3 | |
326 | ** | |
327 | ** The sqlite3_exec() interface is a convenience wrapper around | |
328 | ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], | |
329 | ** that allows an application to run multiple statements of SQL | |
330 | ** without having to use a lot of C code. | |
331 | ** | |
332 | ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, | |
333 | ** semicolon-separate SQL statements passed into its 2nd argument, | |
334 | ** in the context of the [database connection] passed in as its 1st | |
335 | ** argument. ^If the callback function of the 3rd argument to | |
336 | ** sqlite3_exec() is not NULL, then it is invoked for each result row | |
337 | ** coming out of the evaluated SQL statements. ^The 4th argument to | |
338 | ** sqlite3_exec() is relayed through to the 1st argument of each | |
339 | ** callback invocation. ^If the callback pointer to sqlite3_exec() | |
340 | ** is NULL, then no callback is ever invoked and result rows are | |
341 | ** ignored. | |
342 | ** | |
343 | ** ^If an error occurs while evaluating the SQL statements passed into | |
344 | ** sqlite3_exec(), then execution of the current statement stops and | |
345 | ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() | |
346 | ** is not NULL then any error message is written into memory obtained | |
347 | ** from [sqlite3_malloc()] and passed back through the 5th parameter. | |
348 | ** To avoid memory leaks, the application should invoke [sqlite3_free()] | |
349 | ** on error message strings returned through the 5th parameter of | |
350 | ** sqlite3_exec() after the error message string is no longer needed. | |
351 | ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors | |
352 | ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to | |
353 | ** NULL before returning. | |
354 | ** | |
355 | ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() | |
356 | ** routine returns SQLITE_ABORT without invoking the callback again and | |
357 | ** without running any subsequent SQL statements. | |
358 | ** | |
359 | ** ^The 2nd argument to the sqlite3_exec() callback function is the | |
360 | ** number of columns in the result. ^The 3rd argument to the sqlite3_exec() | |
361 | ** callback is an array of pointers to strings obtained as if from | |
362 | ** [sqlite3_column_text()], one for each column. ^If an element of a | |
363 | ** result row is NULL then the corresponding string pointer for the | |
364 | ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the | |
365 | ** sqlite3_exec() callback is an array of pointers to strings where each | |
366 | ** entry represents the name of corresponding result column as obtained | |
367 | ** from [sqlite3_column_name()]. | |
368 | ** | |
369 | ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer | |
370 | ** to an empty string, or a pointer that contains only whitespace and/or | |
371 | ** SQL comments, then no SQL statements are evaluated and the database | |
372 | ** is not changed. | |
373 | ** | |
374 | ** Restrictions: | |
5783a860 | 375 | ** |
08b809f9 EM |
376 | ** <ul> |
377 | ** <li> The application must ensure that the 1st parameter to sqlite3_exec() | |
378 | ** is a valid and open [database connection]. | |
379 | ** <li> The application must not close the [database connection] specified by | |
380 | ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. | |
381 | ** <li> The application must not modify the SQL statement text passed into | |
382 | ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. | |
383 | ** </ul> | |
5783a860 | 384 | */ |
08b809f9 | 385 | SQLITE_API int SQLITE_STDCALL sqlite3_exec( |
5783a860 | 386 | sqlite3*, /* An open database */ |
08b809f9 | 387 | const char *sql, /* SQL to be evaluated */ |
5783a860 AC |
388 | int (*callback)(void*,int,char**,char**), /* Callback function */ |
389 | void *, /* 1st argument to callback */ | |
390 | char **errmsg /* Error msg written here */ | |
391 | ); | |
392 | ||
393 | /* | |
08b809f9 EM |
394 | ** CAPI3REF: Result Codes |
395 | ** KEYWORDS: {result code definitions} | |
5783a860 AC |
396 | ** |
397 | ** Many SQLite functions return an integer result code from the set shown | |
08b809f9 | 398 | ** here in order to indicate success or failure. |
5783a860 | 399 | ** |
08b809f9 EM |
400 | ** New error codes may be added in future versions of SQLite. |
401 | ** | |
402 | ** See also: [extended result code definitions] | |
5783a860 AC |
403 | */ |
404 | #define SQLITE_OK 0 /* Successful result */ | |
405 | /* beginning-of-error-codes */ | |
406 | #define SQLITE_ERROR 1 /* SQL error or missing database */ | |
407 | #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ | |
408 | #define SQLITE_PERM 3 /* Access permission denied */ | |
409 | #define SQLITE_ABORT 4 /* Callback routine requested an abort */ | |
410 | #define SQLITE_BUSY 5 /* The database file is locked */ | |
411 | #define SQLITE_LOCKED 6 /* A table in the database is locked */ | |
412 | #define SQLITE_NOMEM 7 /* A malloc() failed */ | |
413 | #define SQLITE_READONLY 8 /* Attempt to write a readonly database */ | |
414 | #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ | |
415 | #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ | |
416 | #define SQLITE_CORRUPT 11 /* The database disk image is malformed */ | |
08b809f9 | 417 | #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ |
5783a860 AC |
418 | #define SQLITE_FULL 13 /* Insertion failed because database is full */ |
419 | #define SQLITE_CANTOPEN 14 /* Unable to open the database file */ | |
08b809f9 | 420 | #define SQLITE_PROTOCOL 15 /* Database lock protocol error */ |
5783a860 AC |
421 | #define SQLITE_EMPTY 16 /* Database is empty */ |
422 | #define SQLITE_SCHEMA 17 /* The database schema changed */ | |
423 | #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ | |
424 | #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ | |
425 | #define SQLITE_MISMATCH 20 /* Data type mismatch */ | |
426 | #define SQLITE_MISUSE 21 /* Library used incorrectly */ | |
427 | #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ | |
428 | #define SQLITE_AUTH 23 /* Authorization denied */ | |
429 | #define SQLITE_FORMAT 24 /* Auxiliary database format error */ | |
430 | #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ | |
431 | #define SQLITE_NOTADB 26 /* File opened that is not a database file */ | |
08b809f9 EM |
432 | #define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ |
433 | #define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ | |
5783a860 AC |
434 | #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ |
435 | #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ | |
436 | /* end-of-error-codes */ | |
437 | ||
438 | /* | |
08b809f9 EM |
439 | ** CAPI3REF: Extended Result Codes |
440 | ** KEYWORDS: {extended result code definitions} | |
5783a860 | 441 | ** |
08b809f9 EM |
442 | ** In its default configuration, SQLite API routines return one of 30 integer |
443 | ** [result codes]. However, experience has shown that many of | |
444 | ** these result codes are too coarse-grained. They do not provide as | |
5783a860 AC |
445 | ** much information about problems as programmers might like. In an effort to |
446 | ** address this, newer versions of SQLite (version 3.3.8 and later) include | |
447 | ** support for additional result codes that provide more detailed information | |
08b809f9 EM |
448 | ** about errors. These [extended result codes] are enabled or disabled |
449 | ** on a per database connection basis using the | |
450 | ** [sqlite3_extended_result_codes()] API. Or, the extended code for | |
451 | ** the most recent error can be obtained using | |
452 | ** [sqlite3_extended_errcode()]. | |
5783a860 | 453 | */ |
08b809f9 EM |
454 | #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) |
455 | #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) | |
456 | #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) | |
457 | #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) | |
458 | #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) | |
459 | #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) | |
460 | #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) | |
461 | #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) | |
462 | #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) | |
463 | #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) | |
464 | #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) | |
465 | #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) | |
466 | #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) | |
467 | #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) | |
468 | #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) | |
469 | #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) | |
470 | #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) | |
471 | #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) | |
472 | #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) | |
473 | #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) | |
474 | #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) | |
475 | #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) | |
476 | #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) | |
477 | #define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) | |
478 | #define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) | |
479 | #define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) | |
480 | #define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8)) | |
481 | #define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8)) | |
482 | #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) | |
483 | #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) | |
484 | #define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) | |
485 | #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) | |
486 | #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) | |
487 | #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) | |
488 | #define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) | |
489 | #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) | |
490 | #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) | |
491 | #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) | |
492 | #define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) | |
493 | #define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) | |
494 | #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) | |
495 | #define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) | |
496 | #define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) | |
497 | #define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) | |
498 | #define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) | |
499 | #define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) | |
500 | #define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) | |
501 | #define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) | |
502 | #define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) | |
503 | #define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) | |
504 | #define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) | |
505 | #define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) | |
506 | #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) | |
507 | #define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) | |
508 | #define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) | |
5783a860 AC |
509 | |
510 | /* | |
08b809f9 | 511 | ** CAPI3REF: Flags For File Open Operations |
5783a860 AC |
512 | ** |
513 | ** These bit values are intended for use in the | |
514 | ** 3rd parameter to the [sqlite3_open_v2()] interface and | |
08b809f9 EM |
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 | |
5783a860 AC |
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 | |
08b809f9 EM |
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. | |
5783a860 | 567 | */ |
08b809f9 EM |
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 | |
5783a860 AC |
582 | |
583 | /* | |
08b809f9 | 584 | ** CAPI3REF: File Locking Levels |
5783a860 AC |
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 | /* | |
08b809f9 | 597 | ** CAPI3REF: Synchronization Type Flags |
5783a860 AC |
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 | |
08b809f9 EM |
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.) | |
5783a860 AC |
621 | */ |
622 | #define SQLITE_SYNC_NORMAL 0x00002 | |
623 | #define SQLITE_SYNC_FULL 0x00003 | |
624 | #define SQLITE_SYNC_DATAONLY 0x00010 | |
625 | ||
5783a860 | 626 | /* |
08b809f9 | 627 | ** CAPI3REF: OS Interface Open File Handle |
5783a860 | 628 | ** |
08b809f9 EM |
629 | ** An [sqlite3_file] object represents an open file in the |
630 | ** [sqlite3_vfs | OS interface layer]. Individual OS interface | |
631 | ** implementations will | |
5783a860 AC |
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 | /* | |
08b809f9 | 643 | ** CAPI3REF: OS Interface File Virtual Methods Object |
5783a860 | 644 | ** |
08b809f9 EM |
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. | |
5783a860 AC |
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(). | |
08b809f9 EM |
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. | |
4094d2fa | 663 | ** |
5783a860 AC |
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> | |
4094d2fa | 672 | ** xLock() increases the lock. xUnlock() decreases the lock. |
08b809f9 EM |
673 | ** The xCheckReservedLock() method checks whether any database connection, |
674 | ** either in this process or in some other process, is holding a RESERVED, | |
5783a860 | 675 | ** PENDING, or EXCLUSIVE lock on the file. It returns true |
08b809f9 | 676 | ** if such a lock exists and false otherwise. |
4094d2fa | 677 | ** |
5783a860 AC |
678 | ** The xFileControl() method is a generic interface that allows custom |
679 | ** VFS implementations to directly control an open file using the | |
08b809f9 EM |
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 | |
5783a860 AC |
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 | |
08b809f9 EM |
687 | ** core reserves all opcodes less than 100 for its own use. |
688 | ** A [file control opcodes | list of opcodes] less than 100 is available. | |
4094d2fa | 689 | ** Applications that define a custom xFileControl method should use opcodes |
08b809f9 EM |
690 | ** greater than 100 to avoid conflicts. VFS implementations should |
691 | ** return [SQLITE_NOTFOUND] for file control opcodes that they do not | |
692 | ** recognize. | |
5783a860 AC |
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(). | |
08b809f9 EM |
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. | |
5783a860 AC |
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); | |
08b809f9 | 743 | int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); |
5783a860 AC |
744 | int (*xFileControl)(sqlite3_file*, int op, void *pArg); |
745 | int (*xSectorSize)(sqlite3_file*); | |
746 | int (*xDeviceCharacteristics)(sqlite3_file*); | |
08b809f9 EM |
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 */ | |
5783a860 AC |
756 | /* Additional methods may be added in future releases */ |
757 | }; | |
758 | ||
759 | /* | |
08b809f9 EM |
760 | ** CAPI3REF: Standard File Control Opcodes |
761 | ** KEYWORDS: {file control opcodes} {file control opcode} | |
5783a860 AC |
762 | ** |
763 | ** These integer constants are opcodes for the xFileControl method | |
08b809f9 | 764 | ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] |
5783a860 AC |
765 | ** interface. |
766 | ** | |
08b809f9 EM |
767 | ** <ul> |
768 | ** <li>[[SQLITE_FCNTL_LOCKSTATE]] | |
5783a860 AC |
769 | ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This |
770 | ** opcode causes the xFileControl method to write the current state of | |
771 | ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], | |
772 | ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) | |
773 | ** into an integer that the pArg argument points to. This capability | |
08b809f9 EM |
774 | ** is used during testing and is only available when the SQLITE_TEST |
775 | ** compile-time option is used. | |
776 | ** | |
777 | ** <li>[[SQLITE_FCNTL_SIZE_HINT]] | |
778 | ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS | |
779 | ** layer a hint of how large the database file will grow to be during the | |
780 | ** current transaction. This hint is not guaranteed to be accurate but it | |
781 | ** is often close. The underlying VFS might choose to preallocate database | |
782 | ** file space based on this hint in order to help writes to the database | |
783 | ** file run faster. | |
784 | ** | |
785 | ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] | |
786 | ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS | |
787 | ** extends and truncates the database file in chunks of a size specified | |
788 | ** by the user. The fourth argument to [sqlite3_file_control()] should | |
789 | ** point to an integer (type int) containing the new chunk-size to use | |
790 | ** for the nominated database. Allocating database file space in large | |
791 | ** chunks (say 1MB at a time), may reduce file-system fragmentation and | |
792 | ** improve performance on some systems. | |
793 | ** | |
794 | ** <li>[[SQLITE_FCNTL_FILE_POINTER]] | |
795 | ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer | |
796 | ** to the [sqlite3_file] object associated with a particular database | |
797 | ** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. | |
798 | ** | |
799 | ** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] | |
800 | ** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer | |
801 | ** to the [sqlite3_file] object associated with the journal file (either | |
802 | ** the [rollback journal] or the [write-ahead log]) for a particular database | |
803 | ** connection. See also [SQLITE_FCNTL_FILE_POINTER]. | |
804 | ** | |
805 | ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] | |
806 | ** No longer in use. | |
807 | ** | |
808 | ** <li>[[SQLITE_FCNTL_SYNC]] | |
809 | ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and | |
810 | ** sent to the VFS immediately before the xSync method is invoked on a | |
811 | ** database file descriptor. Or, if the xSync method is not invoked | |
812 | ** because the user has configured SQLite with | |
813 | ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place | |
814 | ** of the xSync method. In most cases, the pointer argument passed with | |
815 | ** this file-control is NULL. However, if the database file is being synced | |
816 | ** as part of a multi-database commit, the argument points to a nul-terminated | |
817 | ** string containing the transactions master-journal file name. VFSes that | |
818 | ** do not need this signal should silently ignore this opcode. Applications | |
819 | ** should not call [sqlite3_file_control()] with this opcode as doing so may | |
820 | ** disrupt the operation of the specialized VFSes that do require it. | |
821 | ** | |
822 | ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] | |
823 | ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite | |
824 | ** and sent to the VFS after a transaction has been committed immediately | |
825 | ** but before the database is unlocked. VFSes that do not need this signal | |
826 | ** should silently ignore this opcode. Applications should not call | |
827 | ** [sqlite3_file_control()] with this opcode as doing so may disrupt the | |
828 | ** operation of the specialized VFSes that do require it. | |
829 | ** | |
830 | ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] | |
831 | ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic | |
832 | ** retry counts and intervals for certain disk I/O operations for the | |
833 | ** windows [VFS] in order to provide robustness in the presence of | |
834 | ** anti-virus programs. By default, the windows VFS will retry file read, | |
835 | ** file write, and file delete operations up to 10 times, with a delay | |
836 | ** of 25 milliseconds before the first retry and with the delay increasing | |
837 | ** by an additional 25 milliseconds with each subsequent retry. This | |
838 | ** opcode allows these two values (10 retries and 25 milliseconds of delay) | |
839 | ** to be adjusted. The values are changed for all database connections | |
840 | ** within the same process. The argument is a pointer to an array of two | |
841 | ** integers where the first integer i the new retry count and the second | |
842 | ** integer is the delay. If either integer is negative, then the setting | |
843 | ** is not changed but instead the prior value of that setting is written | |
844 | ** into the array entry, allowing the current retry settings to be | |
845 | ** interrogated. The zDbName parameter is ignored. | |
846 | ** | |
847 | ** <li>[[SQLITE_FCNTL_PERSIST_WAL]] | |
848 | ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the | |
849 | ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary | |
850 | ** write ahead log and shared memory files used for transaction control | |
851 | ** are automatically deleted when the latest connection to the database | |
852 | ** closes. Setting persistent WAL mode causes those files to persist after | |
853 | ** close. Persisting the files is useful when other processes that do not | |
854 | ** have write permission on the directory containing the database file want | |
855 | ** to read the database file, as the WAL and shared memory files must exist | |
856 | ** in order for the database to be readable. The fourth parameter to | |
857 | ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. | |
858 | ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent | |
859 | ** WAL mode. If the integer is -1, then it is overwritten with the current | |
860 | ** WAL persistence setting. | |
861 | ** | |
862 | ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] | |
863 | ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the | |
864 | ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting | |
865 | ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the | |
866 | ** xDeviceCharacteristics methods. The fourth parameter to | |
867 | ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. | |
868 | ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage | |
869 | ** mode. If the integer is -1, then it is overwritten with the current | |
870 | ** zero-damage mode setting. | |
871 | ** | |
872 | ** <li>[[SQLITE_FCNTL_OVERWRITE]] | |
873 | ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening | |
874 | ** a write transaction to indicate that, unless it is rolled back for some | |
875 | ** reason, the entire database file will be overwritten by the current | |
876 | ** transaction. This is used by VACUUM operations. | |
877 | ** | |
878 | ** <li>[[SQLITE_FCNTL_VFSNAME]] | |
879 | ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of | |
880 | ** all [VFSes] in the VFS stack. The names are of all VFS shims and the | |
881 | ** final bottom-level VFS are written into memory obtained from | |
882 | ** [sqlite3_malloc()] and the result is stored in the char* variable | |
883 | ** that the fourth parameter of [sqlite3_file_control()] points to. | |
884 | ** The caller is responsible for freeing the memory when done. As with | |
885 | ** all file-control actions, there is no guarantee that this will actually | |
886 | ** do anything. Callers should initialize the char* variable to a NULL | |
887 | ** pointer in case this file-control is not implemented. This file-control | |
888 | ** is intended for diagnostic use only. | |
889 | ** | |
890 | ** <li>[[SQLITE_FCNTL_VFS_POINTER]] | |
891 | ** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level | |
892 | ** [VFSes] currently in use. ^(The argument X in | |
893 | ** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be | |
894 | ** of type "[sqlite3_vfs] **". This opcodes will set *X | |
895 | ** to a pointer to the top-level VFS.)^ | |
896 | ** ^When there are multiple VFS shims in the stack, this opcode finds the | |
897 | ** upper-most shim only. | |
898 | ** | |
899 | ** <li>[[SQLITE_FCNTL_PRAGMA]] | |
900 | ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] | |
901 | ** file control is sent to the open [sqlite3_file] object corresponding | |
902 | ** to the database file to which the pragma statement refers. ^The argument | |
903 | ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of | |
904 | ** pointers to strings (char**) in which the second element of the array | |
905 | ** is the name of the pragma and the third element is the argument to the | |
906 | ** pragma or NULL if the pragma has no argument. ^The handler for an | |
907 | ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element | |
908 | ** of the char** argument point to a string obtained from [sqlite3_mprintf()] | |
909 | ** or the equivalent and that string will become the result of the pragma or | |
910 | ** the error message if the pragma fails. ^If the | |
911 | ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal | |
912 | ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] | |
913 | ** file control returns [SQLITE_OK], then the parser assumes that the | |
914 | ** VFS has handled the PRAGMA itself and the parser generates a no-op | |
915 | ** prepared statement if result string is NULL, or that returns a copy | |
916 | ** of the result string if the string is non-NULL. | |
917 | ** ^If the [SQLITE_FCNTL_PRAGMA] file control returns | |
918 | ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means | |
919 | ** that the VFS encountered an error while handling the [PRAGMA] and the | |
920 | ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] | |
921 | ** file control occurs at the beginning of pragma statement analysis and so | |
922 | ** it is able to override built-in [PRAGMA] statements. | |
923 | ** | |
924 | ** <li>[[SQLITE_FCNTL_BUSYHANDLER]] | |
925 | ** ^The [SQLITE_FCNTL_BUSYHANDLER] | |
926 | ** file-control may be invoked by SQLite on the database file handle | |
927 | ** shortly after it is opened in order to provide a custom VFS with access | |
928 | ** to the connections busy-handler callback. The argument is of type (void **) | |
929 | ** - an array of two (void *) values. The first (void *) actually points | |
930 | ** to a function of type (int (*)(void *)). In order to invoke the connections | |
931 | ** busy-handler, this function should be invoked with the second (void *) in | |
932 | ** the array as the only argument. If it returns non-zero, then the operation | |
933 | ** should be retried. If it returns zero, the custom VFS should abandon the | |
934 | ** current operation. | |
935 | ** | |
936 | ** <li>[[SQLITE_FCNTL_TEMPFILENAME]] | |
937 | ** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control | |
938 | ** to have SQLite generate a | |
939 | ** temporary filename using the same algorithm that is followed to generate | |
940 | ** temporary filenames for TEMP tables and other internal uses. The | |
941 | ** argument should be a char** which will be filled with the filename | |
942 | ** written into memory obtained from [sqlite3_malloc()]. The caller should | |
943 | ** invoke [sqlite3_free()] on the result to avoid a memory leak. | |
944 | ** | |
945 | ** <li>[[SQLITE_FCNTL_MMAP_SIZE]] | |
946 | ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the | |
947 | ** maximum number of bytes that will be used for memory-mapped I/O. | |
948 | ** The argument is a pointer to a value of type sqlite3_int64 that | |
949 | ** is an advisory maximum number of bytes in the file to memory map. The | |
950 | ** pointer is overwritten with the old value. The limit is not changed if | |
951 | ** the value originally pointed to is negative, and so the current limit | |
952 | ** can be queried by passing in a pointer to a negative number. This | |
953 | ** file-control is used internally to implement [PRAGMA mmap_size]. | |
954 | ** | |
955 | ** <li>[[SQLITE_FCNTL_TRACE]] | |
956 | ** The [SQLITE_FCNTL_TRACE] file control provides advisory information | |
957 | ** to the VFS about what the higher layers of the SQLite stack are doing. | |
958 | ** This file control is used by some VFS activity tracing [shims]. | |
959 | ** The argument is a zero-terminated string. Higher layers in the | |
960 | ** SQLite stack may generate instances of this file control if | |
961 | ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. | |
962 | ** | |
963 | ** <li>[[SQLITE_FCNTL_HAS_MOVED]] | |
964 | ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a | |
965 | ** pointer to an integer and it writes a boolean into that integer depending | |
966 | ** on whether or not the file has been renamed, moved, or deleted since it | |
967 | ** was first opened. | |
968 | ** | |
969 | ** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] | |
970 | ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This | |
971 | ** opcode causes the xFileControl method to swap the file handle with the one | |
972 | ** pointed to by the pArg argument. This capability is used during testing | |
973 | ** and only needs to be supported when SQLITE_TEST is defined. | |
974 | ** | |
975 | ** <li>[[SQLITE_FCNTL_WAL_BLOCK]] | |
976 | ** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might | |
977 | ** be advantageous to block on the next WAL lock if the lock is not immediately | |
978 | ** available. The WAL subsystem issues this signal during rare | |
979 | ** circumstances in order to fix a problem with priority inversion. | |
980 | ** Applications should <em>not</em> use this file-control. | |
981 | ** | |
982 | ** <li>[[SQLITE_FCNTL_ZIPVFS]] | |
983 | ** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other | |
984 | ** VFS should return SQLITE_NOTFOUND for this opcode. | |
985 | ** | |
986 | ** <li>[[SQLITE_FCNTL_RBU]] | |
987 | ** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by | |
988 | ** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for | |
989 | ** this opcode. | |
990 | ** </ul> | |
5783a860 | 991 | */ |
08b809f9 EM |
992 | #define SQLITE_FCNTL_LOCKSTATE 1 |
993 | #define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 | |
994 | #define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 | |
995 | #define SQLITE_FCNTL_LAST_ERRNO 4 | |
996 | #define SQLITE_FCNTL_SIZE_HINT 5 | |
997 | #define SQLITE_FCNTL_CHUNK_SIZE 6 | |
998 | #define SQLITE_FCNTL_FILE_POINTER 7 | |
999 | #define SQLITE_FCNTL_SYNC_OMITTED 8 | |
1000 | #define SQLITE_FCNTL_WIN32_AV_RETRY 9 | |
1001 | #define SQLITE_FCNTL_PERSIST_WAL 10 | |
1002 | #define SQLITE_FCNTL_OVERWRITE 11 | |
1003 | #define SQLITE_FCNTL_VFSNAME 12 | |
1004 | #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 | |
1005 | #define SQLITE_FCNTL_PRAGMA 14 | |
1006 | #define SQLITE_FCNTL_BUSYHANDLER 15 | |
1007 | #define SQLITE_FCNTL_TEMPFILENAME 16 | |
1008 | #define SQLITE_FCNTL_MMAP_SIZE 18 | |
1009 | #define SQLITE_FCNTL_TRACE 19 | |
1010 | #define SQLITE_FCNTL_HAS_MOVED 20 | |
1011 | #define SQLITE_FCNTL_SYNC 21 | |
1012 | #define SQLITE_FCNTL_COMMIT_PHASETWO 22 | |
1013 | #define SQLITE_FCNTL_WIN32_SET_HANDLE 23 | |
1014 | #define SQLITE_FCNTL_WAL_BLOCK 24 | |
1015 | #define SQLITE_FCNTL_ZIPVFS 25 | |
1016 | #define SQLITE_FCNTL_RBU 26 | |
1017 | #define SQLITE_FCNTL_VFS_POINTER 27 | |
1018 | #define SQLITE_FCNTL_JOURNAL_POINTER 28 | |
1019 | ||
1020 | /* deprecated names */ | |
1021 | #define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE | |
1022 | #define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE | |
1023 | #define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO | |
1024 | ||
5783a860 AC |
1025 | |
1026 | /* | |
08b809f9 | 1027 | ** CAPI3REF: Mutex Handle |
5783a860 AC |
1028 | ** |
1029 | ** The mutex module within SQLite defines [sqlite3_mutex] to be an | |
1030 | ** abstract type for a mutex object. The SQLite core never looks | |
1031 | ** at the internal representation of an [sqlite3_mutex]. It only | |
1032 | ** deals with pointers to the [sqlite3_mutex] object. | |
1033 | ** | |
1034 | ** Mutexes are created using [sqlite3_mutex_alloc()]. | |
1035 | */ | |
1036 | typedef struct sqlite3_mutex sqlite3_mutex; | |
1037 | ||
1038 | /* | |
08b809f9 | 1039 | ** CAPI3REF: OS Interface Object |
5783a860 | 1040 | ** |
08b809f9 EM |
1041 | ** An instance of the sqlite3_vfs object defines the interface between |
1042 | ** the SQLite core and the underlying operating system. The "vfs" | |
1043 | ** in the name of the object stands for "virtual file system". See | |
1044 | ** the [VFS | VFS documentation] for further information. | |
5783a860 | 1045 | ** |
08b809f9 EM |
1046 | ** The value of the iVersion field is initially 1 but may be larger in |
1047 | ** future versions of SQLite. Additional fields may be appended to this | |
1048 | ** object when the iVersion value is increased. Note that the structure | |
1049 | ** of the sqlite3_vfs object changes in the transaction between | |
1050 | ** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not | |
1051 | ** modified. | |
5783a860 AC |
1052 | ** |
1053 | ** The szOsFile field is the size of the subclassed [sqlite3_file] | |
1054 | ** structure used by this VFS. mxPathname is the maximum length of | |
1055 | ** a pathname in this VFS. | |
1056 | ** | |
1057 | ** Registered sqlite3_vfs objects are kept on a linked list formed by | |
1058 | ** the pNext pointer. The [sqlite3_vfs_register()] | |
1059 | ** and [sqlite3_vfs_unregister()] interfaces manage this list | |
1060 | ** in a thread-safe way. The [sqlite3_vfs_find()] interface | |
08b809f9 EM |
1061 | ** searches the list. Neither the application code nor the VFS |
1062 | ** implementation should use the pNext pointer. | |
5783a860 | 1063 | ** |
4094d2fa | 1064 | ** The pNext field is the only field in the sqlite3_vfs |
5783a860 AC |
1065 | ** structure that SQLite will ever modify. SQLite will only access |
1066 | ** or modify this field while holding a particular static mutex. | |
1067 | ** The application should never modify anything within the sqlite3_vfs | |
1068 | ** object once the object has been registered. | |
1069 | ** | |
1070 | ** The zName field holds the name of the VFS module. The name must | |
1071 | ** be unique across all VFS modules. | |
1072 | ** | |
08b809f9 EM |
1073 | ** [[sqlite3_vfs.xOpen]] |
1074 | ** ^SQLite guarantees that the zFilename parameter to xOpen | |
1075 | ** is either a NULL pointer or string obtained | |
1076 | ** from xFullPathname() with an optional suffix added. | |
1077 | ** ^If a suffix is added to the zFilename parameter, it will | |
1078 | ** consist of a single "-" character followed by no more than | |
1079 | ** 11 alphanumeric and/or "-" characters. | |
1080 | ** ^SQLite further guarantees that | |
1081 | ** the string will be valid and unchanged until xClose() is | |
1082 | ** called. Because of the previous sentence, | |
1083 | ** the [sqlite3_file] can safely store a pointer to the | |
5783a860 | 1084 | ** filename if it needs to remember the filename for some reason. |
08b809f9 EM |
1085 | ** If the zFilename parameter to xOpen is a NULL pointer then xOpen |
1086 | ** must invent its own temporary name for the file. ^Whenever the | |
1087 | ** xFilename parameter is NULL it will also be the case that the | |
1088 | ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. | |
5783a860 | 1089 | ** |
08b809f9 | 1090 | ** The flags argument to xOpen() includes all bits set in |
5783a860 AC |
1091 | ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] |
1092 | ** or [sqlite3_open16()] is used, then flags includes at least | |
08b809f9 | 1093 | ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. |
5783a860 | 1094 | ** If xOpen() opens a file read-only then it sets *pOutFlags to |
08b809f9 | 1095 | ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. |
4094d2fa | 1096 | ** |
08b809f9 | 1097 | ** ^(SQLite will also add one of the following flags to the xOpen() |
5783a860 | 1098 | ** call, depending on the object being opened: |
4094d2fa | 1099 | ** |
5783a860 AC |
1100 | ** <ul> |
1101 | ** <li> [SQLITE_OPEN_MAIN_DB] | |
1102 | ** <li> [SQLITE_OPEN_MAIN_JOURNAL] | |
1103 | ** <li> [SQLITE_OPEN_TEMP_DB] | |
1104 | ** <li> [SQLITE_OPEN_TEMP_JOURNAL] | |
1105 | ** <li> [SQLITE_OPEN_TRANSIENT_DB] | |
1106 | ** <li> [SQLITE_OPEN_SUBJOURNAL] | |
1107 | ** <li> [SQLITE_OPEN_MASTER_JOURNAL] | |
08b809f9 EM |
1108 | ** <li> [SQLITE_OPEN_WAL] |
1109 | ** </ul>)^ | |
5783a860 AC |
1110 | ** |
1111 | ** The file I/O implementation can use the object type flags to | |
08b809f9 | 1112 | ** change the way it deals with files. For example, an application |
5783a860 AC |
1113 | ** that does not care about crash recovery or rollback might make |
1114 | ** the open of a journal file a no-op. Writes to this journal would | |
4094d2fa EM |
1115 | ** also be no-ops, and any attempt to read the journal would return |
1116 | ** SQLITE_IOERR. Or the implementation might recognize that a database | |
1117 | ** file will be doing page-aligned sector reads and writes in a random | |
5783a860 | 1118 | ** order and set up its I/O subsystem accordingly. |
4094d2fa | 1119 | ** |
08b809f9 | 1120 | ** SQLite might also add one of the following flags to the xOpen method: |
4094d2fa | 1121 | ** |
5783a860 AC |
1122 | ** <ul> |
1123 | ** <li> [SQLITE_OPEN_DELETEONCLOSE] | |
1124 | ** <li> [SQLITE_OPEN_EXCLUSIVE] | |
1125 | ** </ul> | |
4094d2fa | 1126 | ** |
08b809f9 EM |
1127 | ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be |
1128 | ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] | |
1129 | ** will be set for TEMP databases and their journals, transient | |
1130 | ** databases, and subjournals. | |
1131 | ** | |
1132 | ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction | |
1133 | ** with the [SQLITE_OPEN_CREATE] flag, which are both directly | |
1134 | ** analogous to the O_EXCL and O_CREAT flags of the POSIX open() | |
1135 | ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the | |
1136 | ** SQLITE_OPEN_CREATE, is used to indicate that file should always | |
1137 | ** be created, and that it is an error if it already exists. | |
1138 | ** It is <i>not</i> used to indicate the file should be opened | |
1139 | ** for exclusive access. | |
1140 | ** | |
1141 | ** ^At least szOsFile bytes of memory are allocated by SQLite | |
4094d2fa | 1142 | ** to hold the [sqlite3_file] structure passed as the third |
08b809f9 EM |
1143 | ** argument to xOpen. The xOpen method does not have to |
1144 | ** allocate the structure; it should just fill it in. Note that | |
1145 | ** the xOpen method must set the sqlite3_file.pMethods to either | |
1146 | ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do | |
1147 | ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods | |
1148 | ** element will be valid after xOpen returns regardless of the success | |
1149 | ** or failure of the xOpen call. | |
1150 | ** | |
1151 | ** [[sqlite3_vfs.xAccess]] | |
1152 | ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] | |
1153 | ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to | |
1154 | ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] | |
1155 | ** to test whether a file is at least readable. The file can be a | |
5783a860 | 1156 | ** directory. |
4094d2fa | 1157 | ** |
08b809f9 EM |
1158 | ** ^SQLite will always allocate at least mxPathname+1 bytes for the |
1159 | ** output buffer xFullPathname. The exact size of the output buffer | |
1160 | ** is also passed as a parameter to both methods. If the output buffer | |
1161 | ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is | |
1162 | ** handled as a fatal error by SQLite, vfs implementations should endeavor | |
1163 | ** to prevent this by setting mxPathname to a sufficiently large value. | |
4094d2fa | 1164 | ** |
08b809f9 EM |
1165 | ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() |
1166 | ** interfaces are not strictly a part of the filesystem, but they are | |
5783a860 AC |
1167 | ** included in the VFS structure for completeness. |
1168 | ** The xRandomness() function attempts to return nBytes bytes | |
1169 | ** of good-quality randomness into zOut. The return value is | |
08b809f9 EM |
1170 | ** the actual number of bytes of randomness obtained. |
1171 | ** The xSleep() method causes the calling thread to sleep for at | |
1172 | ** least the number of microseconds given. ^The xCurrentTime() | |
1173 | ** method returns a Julian Day Number for the current date and time as | |
1174 | ** a floating point value. | |
1175 | ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian | |
1176 | ** Day Number multiplied by 86400000 (the number of milliseconds in | |
1177 | ** a 24-hour day). | |
1178 | ** ^SQLite will use the xCurrentTimeInt64() method to get the current | |
1179 | ** date and time if that method is available (if iVersion is 2 or | |
1180 | ** greater and the function pointer is not NULL) and will fall back | |
1181 | ** to xCurrentTime() if xCurrentTimeInt64() is unavailable. | |
1182 | ** | |
1183 | ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces | |
1184 | ** are not used by the SQLite core. These optional interfaces are provided | |
1185 | ** by some VFSes to facilitate testing of the VFS code. By overriding | |
1186 | ** system calls with functions under its control, a test program can | |
1187 | ** simulate faults and error conditions that would otherwise be difficult | |
1188 | ** or impossible to induce. The set of system calls that can be overridden | |
1189 | ** varies from one VFS to another, and from one version of the same VFS to the | |
1190 | ** next. Applications that use these interfaces must be prepared for any | |
1191 | ** or all of these interfaces to be NULL or for their behavior to change | |
1192 | ** from one release to the next. Applications must not attempt to access | |
1193 | ** any of these methods if the iVersion of the VFS is less than 3. | |
5783a860 AC |
1194 | */ |
1195 | typedef struct sqlite3_vfs sqlite3_vfs; | |
08b809f9 | 1196 | typedef void (*sqlite3_syscall_ptr)(void); |
5783a860 | 1197 | struct sqlite3_vfs { |
08b809f9 | 1198 | int iVersion; /* Structure version number (currently 3) */ |
5783a860 AC |
1199 | int szOsFile; /* Size of subclassed sqlite3_file */ |
1200 | int mxPathname; /* Maximum file pathname length */ | |
1201 | sqlite3_vfs *pNext; /* Next registered VFS */ | |
1202 | const char *zName; /* Name of this virtual file system */ | |
1203 | void *pAppData; /* Pointer to application-specific data */ | |
1204 | int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, | |
1205 | int flags, int *pOutFlags); | |
1206 | int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); | |
08b809f9 | 1207 | int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); |
5783a860 AC |
1208 | int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); |
1209 | void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); | |
1210 | void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); | |
08b809f9 | 1211 | void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); |
5783a860 AC |
1212 | void (*xDlClose)(sqlite3_vfs*, void*); |
1213 | int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); | |
1214 | int (*xSleep)(sqlite3_vfs*, int microseconds); | |
1215 | int (*xCurrentTime)(sqlite3_vfs*, double*); | |
08b809f9 EM |
1216 | int (*xGetLastError)(sqlite3_vfs*, int, char *); |
1217 | /* | |
1218 | ** The methods above are in version 1 of the sqlite_vfs object | |
1219 | ** definition. Those that follow are added in version 2 or later | |
1220 | */ | |
1221 | int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); | |
1222 | /* | |
1223 | ** The methods above are in versions 1 and 2 of the sqlite_vfs object. | |
1224 | ** Those below are for version 3 and greater. | |
1225 | */ | |
1226 | int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); | |
1227 | sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); | |
1228 | const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); | |
1229 | /* | |
1230 | ** The methods above are in versions 1 through 3 of the sqlite_vfs object. | |
1231 | ** New fields may be appended in future versions. The iVersion | |
1232 | ** value will increment whenever this happens. | |
1233 | */ | |
5783a860 AC |
1234 | }; |
1235 | ||
1236 | /* | |
08b809f9 EM |
1237 | ** CAPI3REF: Flags for the xAccess VFS method |
1238 | ** | |
1239 | ** These integer constants can be used as the third parameter to | |
1240 | ** the xAccess method of an [sqlite3_vfs] object. They determine | |
1241 | ** what kind of permissions the xAccess method is looking for. | |
1242 | ** With SQLITE_ACCESS_EXISTS, the xAccess method | |
1243 | ** simply checks whether the file exists. | |
1244 | ** With SQLITE_ACCESS_READWRITE, the xAccess method | |
1245 | ** checks whether the named directory is both readable and writable | |
1246 | ** (in other words, if files can be added, removed, and renamed within | |
1247 | ** the directory). | |
1248 | ** The SQLITE_ACCESS_READWRITE constant is currently used only by the | |
1249 | ** [temp_store_directory pragma], though this could change in a future | |
1250 | ** release of SQLite. | |
1251 | ** With SQLITE_ACCESS_READ, the xAccess method | |
1252 | ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is | |
1253 | ** currently unused, though it might be used in a future release of | |
1254 | ** SQLite. | |
5783a860 AC |
1255 | */ |
1256 | #define SQLITE_ACCESS_EXISTS 0 | |
08b809f9 EM |
1257 | #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ |
1258 | #define SQLITE_ACCESS_READ 2 /* Unused */ | |
5783a860 AC |
1259 | |
1260 | /* | |
08b809f9 | 1261 | ** CAPI3REF: Flags for the xShmLock VFS method |
5783a860 | 1262 | ** |
08b809f9 EM |
1263 | ** These integer constants define the various locking operations |
1264 | ** allowed by the xShmLock method of [sqlite3_io_methods]. The | |
1265 | ** following are the only legal combinations of flags to the | |
1266 | ** xShmLock method: | |
5783a860 | 1267 | ** |
08b809f9 EM |
1268 | ** <ul> |
1269 | ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED | |
1270 | ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE | |
1271 | ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED | |
1272 | ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE | |
1273 | ** </ul> | |
5783a860 | 1274 | ** |
08b809f9 EM |
1275 | ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as |
1276 | ** was given on the corresponding lock. | |
5783a860 | 1277 | ** |
08b809f9 EM |
1278 | ** The xShmLock method can transition between unlocked and SHARED or |
1279 | ** between unlocked and EXCLUSIVE. It cannot transition between SHARED | |
1280 | ** and EXCLUSIVE. | |
5783a860 | 1281 | */ |
08b809f9 EM |
1282 | #define SQLITE_SHM_UNLOCK 1 |
1283 | #define SQLITE_SHM_LOCK 2 | |
1284 | #define SQLITE_SHM_SHARED 4 | |
1285 | #define SQLITE_SHM_EXCLUSIVE 8 | |
5783a860 AC |
1286 | |
1287 | /* | |
08b809f9 | 1288 | ** CAPI3REF: Maximum xShmLock index |
5783a860 | 1289 | ** |
08b809f9 EM |
1290 | ** The xShmLock method on [sqlite3_io_methods] may use values |
1291 | ** between 0 and this upper bound as its "offset" argument. | |
1292 | ** The SQLite core will never attempt to acquire or release a | |
1293 | ** lock outside of this range | |
1294 | */ | |
1295 | #define SQLITE_SHM_NLOCK 8 | |
1296 | ||
1297 | ||
1298 | /* | |
1299 | ** CAPI3REF: Initialize The SQLite Library | |
1300 | ** | |
1301 | ** ^The sqlite3_initialize() routine initializes the | |
1302 | ** SQLite library. ^The sqlite3_shutdown() routine | |
1303 | ** deallocates any resources that were allocated by sqlite3_initialize(). | |
1304 | ** These routines are designed to aid in process initialization and | |
1305 | ** shutdown on embedded systems. Workstation applications using | |
1306 | ** SQLite normally do not need to invoke either of these routines. | |
1307 | ** | |
1308 | ** A call to sqlite3_initialize() is an "effective" call if it is | |
1309 | ** the first time sqlite3_initialize() is invoked during the lifetime of | |
1310 | ** the process, or if it is the first time sqlite3_initialize() is invoked | |
1311 | ** following a call to sqlite3_shutdown(). ^(Only an effective call | |
1312 | ** of sqlite3_initialize() does any initialization. All other calls | |
1313 | ** are harmless no-ops.)^ | |
1314 | ** | |
1315 | ** A call to sqlite3_shutdown() is an "effective" call if it is the first | |
1316 | ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only | |
1317 | ** an effective call to sqlite3_shutdown() does any deinitialization. | |
1318 | ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ | |
1319 | ** | |
1320 | ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() | |
1321 | ** is not. The sqlite3_shutdown() interface must only be called from a | |
1322 | ** single thread. All open [database connections] must be closed and all | |
1323 | ** other SQLite resources must be deallocated prior to invoking | |
1324 | ** sqlite3_shutdown(). | |
1325 | ** | |
1326 | ** Among other things, ^sqlite3_initialize() will invoke | |
1327 | ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() | |
1328 | ** will invoke sqlite3_os_end(). | |
1329 | ** | |
1330 | ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. | |
1331 | ** ^If for some reason, sqlite3_initialize() is unable to initialize | |
1332 | ** the library (perhaps it is unable to allocate a needed resource such | |
1333 | ** as a mutex) it returns an [error code] other than [SQLITE_OK]. | |
1334 | ** | |
1335 | ** ^The sqlite3_initialize() routine is called internally by many other | |
1336 | ** SQLite interfaces so that an application usually does not need to | |
1337 | ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] | |
1338 | ** calls sqlite3_initialize() so the SQLite library will be automatically | |
1339 | ** initialized when [sqlite3_open()] is called if it has not be initialized | |
1340 | ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] | |
1341 | ** compile-time option, then the automatic calls to sqlite3_initialize() | |
1342 | ** are omitted and the application must call sqlite3_initialize() directly | |
1343 | ** prior to using any other SQLite interface. For maximum portability, | |
1344 | ** it is recommended that applications always invoke sqlite3_initialize() | |
1345 | ** directly prior to using any other SQLite interface. Future releases | |
1346 | ** of SQLite may require this. In other words, the behavior exhibited | |
1347 | ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the | |
1348 | ** default behavior in some future release of SQLite. | |
1349 | ** | |
1350 | ** The sqlite3_os_init() routine does operating-system specific | |
1351 | ** initialization of the SQLite library. The sqlite3_os_end() | |
1352 | ** routine undoes the effect of sqlite3_os_init(). Typical tasks | |
1353 | ** performed by these routines include allocation or deallocation | |
1354 | ** of static resources, initialization of global variables, | |
1355 | ** setting up a default [sqlite3_vfs] module, or setting up | |
1356 | ** a default configuration using [sqlite3_config()]. | |
1357 | ** | |
1358 | ** The application should never invoke either sqlite3_os_init() | |
1359 | ** or sqlite3_os_end() directly. The application should only invoke | |
1360 | ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() | |
1361 | ** interface is called automatically by sqlite3_initialize() and | |
1362 | ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate | |
1363 | ** implementations for sqlite3_os_init() and sqlite3_os_end() | |
1364 | ** are built into SQLite when it is compiled for Unix, Windows, or OS/2. | |
1365 | ** When [custom builds | built for other platforms] | |
1366 | ** (using the [SQLITE_OS_OTHER=1] compile-time | |
1367 | ** option) the application must supply a suitable implementation for | |
1368 | ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied | |
1369 | ** implementation of sqlite3_os_init() or sqlite3_os_end() | |
1370 | ** must return [SQLITE_OK] on success and some other [error code] upon | |
1371 | ** failure. | |
1372 | */ | |
1373 | SQLITE_API int SQLITE_STDCALL sqlite3_initialize(void); | |
1374 | SQLITE_API int SQLITE_STDCALL sqlite3_shutdown(void); | |
1375 | SQLITE_API int SQLITE_STDCALL sqlite3_os_init(void); | |
1376 | SQLITE_API int SQLITE_STDCALL sqlite3_os_end(void); | |
1377 | ||
1378 | /* | |
1379 | ** CAPI3REF: Configuring The SQLite Library | |
1380 | ** | |
1381 | ** The sqlite3_config() interface is used to make global configuration | |
1382 | ** changes to SQLite in order to tune SQLite to the specific needs of | |
1383 | ** the application. The default configuration is recommended for most | |
1384 | ** applications and so this routine is usually not necessary. It is | |
1385 | ** provided to support rare applications with unusual needs. | |
1386 | ** | |
1387 | ** <b>The sqlite3_config() interface is not threadsafe. The application | |
1388 | ** must ensure that no other SQLite interfaces are invoked by other | |
1389 | ** threads while sqlite3_config() is running.</b> | |
1390 | ** | |
1391 | ** The sqlite3_config() interface | |
1392 | ** may only be invoked prior to library initialization using | |
1393 | ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. | |
1394 | ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before | |
1395 | ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. | |
1396 | ** Note, however, that ^sqlite3_config() can be called as part of the | |
1397 | ** implementation of an application-defined [sqlite3_os_init()]. | |
1398 | ** | |
1399 | ** The first argument to sqlite3_config() is an integer | |
1400 | ** [configuration option] that determines | |
1401 | ** what property of SQLite is to be configured. Subsequent arguments | |
1402 | ** vary depending on the [configuration option] | |
1403 | ** in the first argument. | |
1404 | ** | |
1405 | ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. | |
1406 | ** ^If the option is unknown or SQLite is unable to set the option | |
1407 | ** then this routine returns a non-zero [error code]. | |
1408 | */ | |
1409 | SQLITE_API int SQLITE_CDECL sqlite3_config(int, ...); | |
1410 | ||
1411 | /* | |
1412 | ** CAPI3REF: Configure database connections | |
1413 | ** METHOD: sqlite3 | |
1414 | ** | |
1415 | ** The sqlite3_db_config() interface is used to make configuration | |
1416 | ** changes to a [database connection]. The interface is similar to | |
1417 | ** [sqlite3_config()] except that the changes apply to a single | |
1418 | ** [database connection] (specified in the first argument). | |
1419 | ** | |
1420 | ** The second argument to sqlite3_db_config(D,V,...) is the | |
1421 | ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code | |
1422 | ** that indicates what aspect of the [database connection] is being configured. | |
1423 | ** Subsequent arguments vary depending on the configuration verb. | |
1424 | ** | |
1425 | ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if | |
1426 | ** the call is considered successful. | |
1427 | */ | |
1428 | SQLITE_API int SQLITE_CDECL sqlite3_db_config(sqlite3*, int op, ...); | |
1429 | ||
1430 | /* | |
1431 | ** CAPI3REF: Memory Allocation Routines | |
1432 | ** | |
1433 | ** An instance of this object defines the interface between SQLite | |
1434 | ** and low-level memory allocation routines. | |
1435 | ** | |
1436 | ** This object is used in only one place in the SQLite interface. | |
1437 | ** A pointer to an instance of this object is the argument to | |
1438 | ** [sqlite3_config()] when the configuration option is | |
1439 | ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. | |
1440 | ** By creating an instance of this object | |
1441 | ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) | |
1442 | ** during configuration, an application can specify an alternative | |
1443 | ** memory allocation subsystem for SQLite to use for all of its | |
1444 | ** dynamic memory needs. | |
1445 | ** | |
1446 | ** Note that SQLite comes with several [built-in memory allocators] | |
1447 | ** that are perfectly adequate for the overwhelming majority of applications | |
1448 | ** and that this object is only useful to a tiny minority of applications | |
1449 | ** with specialized memory allocation requirements. This object is | |
1450 | ** also used during testing of SQLite in order to specify an alternative | |
1451 | ** memory allocator that simulates memory out-of-memory conditions in | |
1452 | ** order to verify that SQLite recovers gracefully from such | |
1453 | ** conditions. | |
1454 | ** | |
1455 | ** The xMalloc, xRealloc, and xFree methods must work like the | |
1456 | ** malloc(), realloc() and free() functions from the standard C library. | |
1457 | ** ^SQLite guarantees that the second argument to | |
1458 | ** xRealloc is always a value returned by a prior call to xRoundup. | |
1459 | ** | |
1460 | ** xSize should return the allocated size of a memory allocation | |
1461 | ** previously obtained from xMalloc or xRealloc. The allocated size | |
1462 | ** is always at least as big as the requested size but may be larger. | |
1463 | ** | |
1464 | ** The xRoundup method returns what would be the allocated size of | |
1465 | ** a memory allocation given a particular requested size. Most memory | |
1466 | ** allocators round up memory allocations at least to the next multiple | |
1467 | ** of 8. Some allocators round up to a larger multiple or to a power of 2. | |
1468 | ** Every memory allocation request coming in through [sqlite3_malloc()] | |
1469 | ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, | |
1470 | ** that causes the corresponding memory allocation to fail. | |
1471 | ** | |
1472 | ** The xInit method initializes the memory allocator. For example, | |
1473 | ** it might allocate any require mutexes or initialize internal data | |
1474 | ** structures. The xShutdown method is invoked (indirectly) by | |
1475 | ** [sqlite3_shutdown()] and should deallocate any resources acquired | |
1476 | ** by xInit. The pAppData pointer is used as the only parameter to | |
1477 | ** xInit and xShutdown. | |
1478 | ** | |
1479 | ** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes | |
1480 | ** the xInit method, so the xInit method need not be threadsafe. The | |
1481 | ** xShutdown method is only called from [sqlite3_shutdown()] so it does | |
1482 | ** not need to be threadsafe either. For all other methods, SQLite | |
1483 | ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the | |
1484 | ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which | |
1485 | ** it is by default) and so the methods are automatically serialized. | |
1486 | ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other | |
1487 | ** methods must be threadsafe or else make their own arrangements for | |
1488 | ** serialization. | |
1489 | ** | |
1490 | ** SQLite will never invoke xInit() more than once without an intervening | |
1491 | ** call to xShutdown(). | |
1492 | */ | |
1493 | typedef struct sqlite3_mem_methods sqlite3_mem_methods; | |
1494 | struct sqlite3_mem_methods { | |
1495 | void *(*xMalloc)(int); /* Memory allocation function */ | |
1496 | void (*xFree)(void*); /* Free a prior allocation */ | |
1497 | void *(*xRealloc)(void*,int); /* Resize an allocation */ | |
1498 | int (*xSize)(void*); /* Return the size of an allocation */ | |
1499 | int (*xRoundup)(int); /* Round up request size to allocation size */ | |
1500 | int (*xInit)(void*); /* Initialize the memory allocator */ | |
1501 | void (*xShutdown)(void*); /* Deinitialize the memory allocator */ | |
1502 | void *pAppData; /* Argument to xInit() and xShutdown() */ | |
1503 | }; | |
1504 | ||
1505 | /* | |
1506 | ** CAPI3REF: Configuration Options | |
1507 | ** KEYWORDS: {configuration option} | |
1508 | ** | |
1509 | ** These constants are the available integer configuration options that | |
1510 | ** can be passed as the first argument to the [sqlite3_config()] interface. | |
1511 | ** | |
1512 | ** New configuration options may be added in future releases of SQLite. | |
1513 | ** Existing configuration options might be discontinued. Applications | |
1514 | ** should check the return code from [sqlite3_config()] to make sure that | |
1515 | ** the call worked. The [sqlite3_config()] interface will return a | |
1516 | ** non-zero [error code] if a discontinued or unsupported configuration option | |
1517 | ** is invoked. | |
1518 | ** | |
1519 | ** <dl> | |
1520 | ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> | |
1521 | ** <dd>There are no arguments to this option. ^This option sets the | |
1522 | ** [threading mode] to Single-thread. In other words, it disables | |
1523 | ** all mutexing and puts SQLite into a mode where it can only be used | |
1524 | ** by a single thread. ^If SQLite is compiled with | |
1525 | ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then | |
1526 | ** it is not possible to change the [threading mode] from its default | |
1527 | ** value of Single-thread and so [sqlite3_config()] will return | |
1528 | ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD | |
1529 | ** configuration option.</dd> | |
1530 | ** | |
1531 | ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> | |
1532 | ** <dd>There are no arguments to this option. ^This option sets the | |
1533 | ** [threading mode] to Multi-thread. In other words, it disables | |
1534 | ** mutexing on [database connection] and [prepared statement] objects. | |
1535 | ** The application is responsible for serializing access to | |
1536 | ** [database connections] and [prepared statements]. But other mutexes | |
1537 | ** are enabled so that SQLite will be safe to use in a multi-threaded | |
1538 | ** environment as long as no two threads attempt to use the same | |
1539 | ** [database connection] at the same time. ^If SQLite is compiled with | |
1540 | ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then | |
1541 | ** it is not possible to set the Multi-thread [threading mode] and | |
1542 | ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the | |
1543 | ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> | |
1544 | ** | |
1545 | ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> | |
1546 | ** <dd>There are no arguments to this option. ^This option sets the | |
1547 | ** [threading mode] to Serialized. In other words, this option enables | |
1548 | ** all mutexes including the recursive | |
1549 | ** mutexes on [database connection] and [prepared statement] objects. | |
1550 | ** In this mode (which is the default when SQLite is compiled with | |
1551 | ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access | |
1552 | ** to [database connections] and [prepared statements] so that the | |
1553 | ** application is free to use the same [database connection] or the | |
1554 | ** same [prepared statement] in different threads at the same time. | |
1555 | ** ^If SQLite is compiled with | |
1556 | ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then | |
1557 | ** it is not possible to set the Serialized [threading mode] and | |
1558 | ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the | |
1559 | ** SQLITE_CONFIG_SERIALIZED configuration option.</dd> | |
1560 | ** | |
1561 | ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> | |
1562 | ** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is | |
1563 | ** a pointer to an instance of the [sqlite3_mem_methods] structure. | |
1564 | ** The argument specifies | |
1565 | ** alternative low-level memory allocation routines to be used in place of | |
1566 | ** the memory allocation routines built into SQLite.)^ ^SQLite makes | |
1567 | ** its own private copy of the content of the [sqlite3_mem_methods] structure | |
1568 | ** before the [sqlite3_config()] call returns.</dd> | |
1569 | ** | |
1570 | ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> | |
1571 | ** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which | |
1572 | ** is a pointer to an instance of the [sqlite3_mem_methods] structure. | |
1573 | ** The [sqlite3_mem_methods] | |
1574 | ** structure is filled with the currently defined memory allocation routines.)^ | |
1575 | ** This option can be used to overload the default memory allocation | |
1576 | ** routines with a wrapper that simulations memory allocation failure or | |
1577 | ** tracks memory usage, for example. </dd> | |
1578 | ** | |
1579 | ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> | |
1580 | ** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, | |
1581 | ** interpreted as a boolean, which enables or disables the collection of | |
1582 | ** memory allocation statistics. ^(When memory allocation statistics are | |
1583 | ** disabled, the following SQLite interfaces become non-operational: | |
1584 | ** <ul> | |
1585 | ** <li> [sqlite3_memory_used()] | |
1586 | ** <li> [sqlite3_memory_highwater()] | |
1587 | ** <li> [sqlite3_soft_heap_limit64()] | |
1588 | ** <li> [sqlite3_status64()] | |
1589 | ** </ul>)^ | |
1590 | ** ^Memory allocation statistics are enabled by default unless SQLite is | |
1591 | ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory | |
1592 | ** allocation statistics are disabled by default. | |
1593 | ** </dd> | |
1594 | ** | |
1595 | ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> | |
1596 | ** <dd> ^The SQLITE_CONFIG_SCRATCH option specifies a static memory buffer | |
1597 | ** that SQLite can use for scratch memory. ^(There are three arguments | |
1598 | ** to SQLITE_CONFIG_SCRATCH: A pointer an 8-byte | |
1599 | ** aligned memory buffer from which the scratch allocations will be | |
1600 | ** drawn, the size of each scratch allocation (sz), | |
1601 | ** and the maximum number of scratch allocations (N).)^ | |
1602 | ** The first argument must be a pointer to an 8-byte aligned buffer | |
1603 | ** of at least sz*N bytes of memory. | |
1604 | ** ^SQLite will not use more than one scratch buffers per thread. | |
1605 | ** ^SQLite will never request a scratch buffer that is more than 6 | |
1606 | ** times the database page size. | |
1607 | ** ^If SQLite needs needs additional | |
1608 | ** scratch memory beyond what is provided by this configuration option, then | |
1609 | ** [sqlite3_malloc()] will be used to obtain the memory needed.<p> | |
1610 | ** ^When the application provides any amount of scratch memory using | |
1611 | ** SQLITE_CONFIG_SCRATCH, SQLite avoids unnecessary large | |
1612 | ** [sqlite3_malloc|heap allocations]. | |
1613 | ** This can help [Robson proof|prevent memory allocation failures] due to heap | |
1614 | ** fragmentation in low-memory embedded systems. | |
1615 | ** </dd> | |
1616 | ** | |
1617 | ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> | |
1618 | ** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool | |
1619 | ** that SQLite can use for the database page cache with the default page | |
1620 | ** cache implementation. | |
1621 | ** This configuration option is a no-op if an application-define page | |
1622 | ** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. | |
1623 | ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to | |
1624 | ** 8-byte aligned memory (pMem), the size of each page cache line (sz), | |
1625 | ** and the number of cache lines (N). | |
1626 | ** The sz argument should be the size of the largest database page | |
1627 | ** (a power of two between 512 and 65536) plus some extra bytes for each | |
1628 | ** page header. ^The number of extra bytes needed by the page header | |
1629 | ** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. | |
1630 | ** ^It is harmless, apart from the wasted memory, | |
1631 | ** for the sz parameter to be larger than necessary. The pMem | |
1632 | ** argument must be either a NULL pointer or a pointer to an 8-byte | |
1633 | ** aligned block of memory of at least sz*N bytes, otherwise | |
1634 | ** subsequent behavior is undefined. | |
1635 | ** ^When pMem is not NULL, SQLite will strive to use the memory provided | |
1636 | ** to satisfy page cache needs, falling back to [sqlite3_malloc()] if | |
1637 | ** a page cache line is larger than sz bytes or if all of the pMem buffer | |
1638 | ** is exhausted. | |
1639 | ** ^If pMem is NULL and N is non-zero, then each database connection | |
1640 | ** does an initial bulk allocation for page cache memory | |
1641 | ** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or | |
1642 | ** of -1024*N bytes if N is negative, . ^If additional | |
1643 | ** page cache memory is needed beyond what is provided by the initial | |
1644 | ** allocation, then SQLite goes to [sqlite3_malloc()] separately for each | |
1645 | ** additional cache line. </dd> | |
1646 | ** | |
1647 | ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> | |
1648 | ** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer | |
1649 | ** that SQLite will use for all of its dynamic memory allocation needs | |
1650 | ** beyond those provided for by [SQLITE_CONFIG_SCRATCH] and | |
1651 | ** [SQLITE_CONFIG_PAGECACHE]. | |
1652 | ** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled | |
1653 | ** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns | |
1654 | ** [SQLITE_ERROR] if invoked otherwise. | |
1655 | ** ^There are three arguments to SQLITE_CONFIG_HEAP: | |
1656 | ** An 8-byte aligned pointer to the memory, | |
1657 | ** the number of bytes in the memory buffer, and the minimum allocation size. | |
1658 | ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts | |
1659 | ** to using its default memory allocator (the system malloc() implementation), | |
1660 | ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the | |
1661 | ** memory pointer is not NULL then the alternative memory | |
1662 | ** allocator is engaged to handle all of SQLites memory allocation needs. | |
1663 | ** The first pointer (the memory pointer) must be aligned to an 8-byte | |
1664 | ** boundary or subsequent behavior of SQLite will be undefined. | |
1665 | ** The minimum allocation size is capped at 2**12. Reasonable values | |
1666 | ** for the minimum allocation size are 2**5 through 2**8.</dd> | |
1667 | ** | |
1668 | ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> | |
1669 | ** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a | |
1670 | ** pointer to an instance of the [sqlite3_mutex_methods] structure. | |
1671 | ** The argument specifies alternative low-level mutex routines to be used | |
1672 | ** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of | |
1673 | ** the content of the [sqlite3_mutex_methods] structure before the call to | |
1674 | ** [sqlite3_config()] returns. ^If SQLite is compiled with | |
1675 | ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then | |
1676 | ** the entire mutexing subsystem is omitted from the build and hence calls to | |
1677 | ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will | |
1678 | ** return [SQLITE_ERROR].</dd> | |
1679 | ** | |
1680 | ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> | |
1681 | ** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which | |
1682 | ** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The | |
1683 | ** [sqlite3_mutex_methods] | |
1684 | ** structure is filled with the currently defined mutex routines.)^ | |
1685 | ** This option can be used to overload the default mutex allocation | |
1686 | ** routines with a wrapper used to track mutex usage for performance | |
1687 | ** profiling or testing, for example. ^If SQLite is compiled with | |
1688 | ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then | |
1689 | ** the entire mutexing subsystem is omitted from the build and hence calls to | |
1690 | ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will | |
1691 | ** return [SQLITE_ERROR].</dd> | |
1692 | ** | |
1693 | ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> | |
1694 | ** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine | |
1695 | ** the default size of lookaside memory on each [database connection]. | |
1696 | ** The first argument is the | |
1697 | ** size of each lookaside buffer slot and the second is the number of | |
1698 | ** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE | |
1699 | ** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] | |
1700 | ** option to [sqlite3_db_config()] can be used to change the lookaside | |
1701 | ** configuration on individual connections.)^ </dd> | |
1702 | ** | |
1703 | ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> | |
1704 | ** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is | |
1705 | ** a pointer to an [sqlite3_pcache_methods2] object. This object specifies | |
1706 | ** the interface to a custom page cache implementation.)^ | |
1707 | ** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> | |
1708 | ** | |
1709 | ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> | |
1710 | ** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which | |
1711 | ** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of | |
1712 | ** the current page cache implementation into that object.)^ </dd> | |
1713 | ** | |
1714 | ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> | |
1715 | ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite | |
1716 | ** global [error log]. | |
1717 | ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a | |
1718 | ** function with a call signature of void(*)(void*,int,const char*), | |
1719 | ** and a pointer to void. ^If the function pointer is not NULL, it is | |
1720 | ** invoked by [sqlite3_log()] to process each logging event. ^If the | |
1721 | ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. | |
1722 | ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is | |
1723 | ** passed through as the first parameter to the application-defined logger | |
1724 | ** function whenever that function is invoked. ^The second parameter to | |
1725 | ** the logger function is a copy of the first parameter to the corresponding | |
1726 | ** [sqlite3_log()] call and is intended to be a [result code] or an | |
1727 | ** [extended result code]. ^The third parameter passed to the logger is | |
1728 | ** log message after formatting via [sqlite3_snprintf()]. | |
1729 | ** The SQLite logging interface is not reentrant; the logger function | |
1730 | ** supplied by the application must not invoke any SQLite interface. | |
1731 | ** In a multi-threaded application, the application-defined logger | |
1732 | ** function must be threadsafe. </dd> | |
1733 | ** | |
1734 | ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI | |
1735 | ** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. | |
1736 | ** If non-zero, then URI handling is globally enabled. If the parameter is zero, | |
1737 | ** then URI handling is globally disabled.)^ ^If URI handling is globally | |
1738 | ** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], | |
1739 | ** [sqlite3_open16()] or | |
1740 | ** specified as part of [ATTACH] commands are interpreted as URIs, regardless | |
1741 | ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database | |
1742 | ** connection is opened. ^If it is globally disabled, filenames are | |
1743 | ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the | |
1744 | ** database connection is opened. ^(By default, URI handling is globally | |
1745 | ** disabled. The default value may be changed by compiling with the | |
1746 | ** [SQLITE_USE_URI] symbol defined.)^ | |
1747 | ** | |
1748 | ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN | |
1749 | ** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer | |
1750 | ** argument which is interpreted as a boolean in order to enable or disable | |
1751 | ** the use of covering indices for full table scans in the query optimizer. | |
1752 | ** ^The default setting is determined | |
1753 | ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" | |
1754 | ** if that compile-time option is omitted. | |
1755 | ** The ability to disable the use of covering indices for full table scans | |
1756 | ** is because some incorrectly coded legacy applications might malfunction | |
1757 | ** when the optimization is enabled. Providing the ability to | |
1758 | ** disable the optimization allows the older, buggy application code to work | |
1759 | ** without change even with newer versions of SQLite. | |
1760 | ** | |
1761 | ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] | |
1762 | ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE | |
1763 | ** <dd> These options are obsolete and should not be used by new code. | |
1764 | ** They are retained for backwards compatibility but are now no-ops. | |
1765 | ** </dd> | |
1766 | ** | |
1767 | ** [[SQLITE_CONFIG_SQLLOG]] | |
1768 | ** <dt>SQLITE_CONFIG_SQLLOG | |
1769 | ** <dd>This option is only available if sqlite is compiled with the | |
1770 | ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should | |
1771 | ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). | |
1772 | ** The second should be of type (void*). The callback is invoked by the library | |
1773 | ** in three separate circumstances, identified by the value passed as the | |
1774 | ** fourth parameter. If the fourth parameter is 0, then the database connection | |
1775 | ** passed as the second argument has just been opened. The third argument | |
1776 | ** points to a buffer containing the name of the main database file. If the | |
1777 | ** fourth parameter is 1, then the SQL statement that the third parameter | |
1778 | ** points to has just been executed. Or, if the fourth parameter is 2, then | |
1779 | ** the connection being passed as the second parameter is being closed. The | |
1780 | ** third parameter is passed NULL In this case. An example of using this | |
1781 | ** configuration option can be seen in the "test_sqllog.c" source file in | |
1782 | ** the canonical SQLite source tree.</dd> | |
1783 | ** | |
1784 | ** [[SQLITE_CONFIG_MMAP_SIZE]] | |
1785 | ** <dt>SQLITE_CONFIG_MMAP_SIZE | |
1786 | ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values | |
1787 | ** that are the default mmap size limit (the default setting for | |
1788 | ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. | |
1789 | ** ^The default setting can be overridden by each database connection using | |
1790 | ** either the [PRAGMA mmap_size] command, or by using the | |
1791 | ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size | |
1792 | ** will be silently truncated if necessary so that it does not exceed the | |
1793 | ** compile-time maximum mmap size set by the | |
1794 | ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ | |
1795 | ** ^If either argument to this option is negative, then that argument is | |
1796 | ** changed to its compile-time default. | |
1797 | ** | |
1798 | ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] | |
1799 | ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE | |
1800 | ** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is | |
1801 | ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro | |
1802 | ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value | |
1803 | ** that specifies the maximum size of the created heap. | |
1804 | ** | |
1805 | ** [[SQLITE_CONFIG_PCACHE_HDRSZ]] | |
1806 | ** <dt>SQLITE_CONFIG_PCACHE_HDRSZ | |
1807 | ** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which | |
1808 | ** is a pointer to an integer and writes into that integer the number of extra | |
1809 | ** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. | |
1810 | ** The amount of extra space required can change depending on the compiler, | |
1811 | ** target platform, and SQLite version. | |
1812 | ** | |
1813 | ** [[SQLITE_CONFIG_PMASZ]] | |
1814 | ** <dt>SQLITE_CONFIG_PMASZ | |
1815 | ** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which | |
1816 | ** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded | |
1817 | ** sorter to that integer. The default minimum PMA Size is set by the | |
1818 | ** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched | |
1819 | ** to help with sort operations when multithreaded sorting | |
1820 | ** is enabled (using the [PRAGMA threads] command) and the amount of content | |
1821 | ** to be sorted exceeds the page size times the minimum of the | |
1822 | ** [PRAGMA cache_size] setting and this value. | |
1823 | ** | |
1824 | ** [[SQLITE_CONFIG_STMTJRNL_SPILL]] | |
1825 | ** <dt>SQLITE_CONFIG_STMTJRNL_SPILL | |
1826 | ** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which | |
1827 | ** becomes the [statement journal] spill-to-disk threshold. | |
1828 | ** [Statement journals] are held in memory until their size (in bytes) | |
1829 | ** exceeds this threshold, at which point they are written to disk. | |
1830 | ** Or if the threshold is -1, statement journals are always held | |
1831 | ** exclusively in memory. | |
1832 | ** Since many statement journals never become large, setting the spill | |
1833 | ** threshold to a value such as 64KiB can greatly reduce the amount of | |
1834 | ** I/O required to support statement rollback. | |
1835 | ** The default value for this setting is controlled by the | |
1836 | ** [SQLITE_STMTJRNL_SPILL] compile-time option. | |
1837 | ** </dl> | |
1838 | */ | |
1839 | #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ | |
1840 | #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ | |
1841 | #define SQLITE_CONFIG_SERIALIZED 3 /* nil */ | |
1842 | #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ | |
1843 | #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ | |
1844 | #define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ | |
1845 | #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ | |
1846 | #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ | |
1847 | #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ | |
1848 | #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ | |
1849 | #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ | |
1850 | /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ | |
1851 | #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ | |
1852 | #define SQLITE_CONFIG_PCACHE 14 /* no-op */ | |
1853 | #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ | |
1854 | #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ | |
1855 | #define SQLITE_CONFIG_URI 17 /* int */ | |
1856 | #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ | |
1857 | #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ | |
1858 | #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ | |
1859 | #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ | |
1860 | #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ | |
1861 | #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ | |
1862 | #define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ | |
1863 | #define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ | |
1864 | #define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ | |
1865 | ||
1866 | /* | |
1867 | ** CAPI3REF: Database Connection Configuration Options | |
1868 | ** | |
1869 | ** These constants are the available integer configuration options that | |
1870 | ** can be passed as the second argument to the [sqlite3_db_config()] interface. | |
1871 | ** | |
1872 | ** New configuration options may be added in future releases of SQLite. | |
1873 | ** Existing configuration options might be discontinued. Applications | |
1874 | ** should check the return code from [sqlite3_db_config()] to make sure that | |
1875 | ** the call worked. ^The [sqlite3_db_config()] interface will return a | |
1876 | ** non-zero [error code] if a discontinued or unsupported configuration option | |
1877 | ** is invoked. | |
1878 | ** | |
1879 | ** <dl> | |
1880 | ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> | |
1881 | ** <dd> ^This option takes three additional arguments that determine the | |
1882 | ** [lookaside memory allocator] configuration for the [database connection]. | |
1883 | ** ^The first argument (the third parameter to [sqlite3_db_config()] is a | |
1884 | ** pointer to a memory buffer to use for lookaside memory. | |
1885 | ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb | |
1886 | ** may be NULL in which case SQLite will allocate the | |
1887 | ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the | |
1888 | ** size of each lookaside buffer slot. ^The third argument is the number of | |
1889 | ** slots. The size of the buffer in the first argument must be greater than | |
1890 | ** or equal to the product of the second and third arguments. The buffer | |
1891 | ** must be aligned to an 8-byte boundary. ^If the second argument to | |
1892 | ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally | |
1893 | ** rounded down to the next smaller multiple of 8. ^(The lookaside memory | |
1894 | ** configuration for a database connection can only be changed when that | |
1895 | ** connection is not currently using lookaside memory, or in other words | |
1896 | ** when the "current value" returned by | |
1897 | ** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. | |
1898 | ** Any attempt to change the lookaside memory configuration when lookaside | |
1899 | ** memory is in use leaves the configuration unchanged and returns | |
1900 | ** [SQLITE_BUSY].)^</dd> | |
1901 | ** | |
1902 | ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> | |
1903 | ** <dd> ^This option is used to enable or disable the enforcement of | |
1904 | ** [foreign key constraints]. There should be two additional arguments. | |
1905 | ** The first argument is an integer which is 0 to disable FK enforcement, | |
1906 | ** positive to enable FK enforcement or negative to leave FK enforcement | |
1907 | ** unchanged. The second parameter is a pointer to an integer into which | |
1908 | ** is written 0 or 1 to indicate whether FK enforcement is off or on | |
1909 | ** following this call. The second parameter may be a NULL pointer, in | |
1910 | ** which case the FK enforcement setting is not reported back. </dd> | |
1911 | ** | |
1912 | ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> | |
1913 | ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. | |
1914 | ** There should be two additional arguments. | |
1915 | ** The first argument is an integer which is 0 to disable triggers, | |
1916 | ** positive to enable triggers or negative to leave the setting unchanged. | |
1917 | ** The second parameter is a pointer to an integer into which | |
1918 | ** is written 0 or 1 to indicate whether triggers are disabled or enabled | |
1919 | ** following this call. The second parameter may be a NULL pointer, in | |
1920 | ** which case the trigger setting is not reported back. </dd> | |
1921 | ** | |
1922 | ** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> | |
1923 | ** <dd> ^This option is used to enable or disable the two-argument | |
1924 | ** version of the [fts3_tokenizer()] function which is part of the | |
1925 | ** [FTS3] full-text search engine extension. | |
1926 | ** There should be two additional arguments. | |
1927 | ** The first argument is an integer which is 0 to disable fts3_tokenizer() or | |
1928 | ** positive to enable fts3_tokenizer() or negative to leave the setting | |
1929 | ** unchanged. | |
1930 | ** The second parameter is a pointer to an integer into which | |
1931 | ** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled | |
1932 | ** following this call. The second parameter may be a NULL pointer, in | |
1933 | ** which case the new setting is not reported back. </dd> | |
5783a860 | 1934 | ** |
08b809f9 EM |
1935 | ** </dl> |
1936 | */ | |
1937 | #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ | |
1938 | #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ | |
1939 | #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ | |
1940 | #define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ | |
1941 | ||
1942 | ||
1943 | /* | |
1944 | ** CAPI3REF: Enable Or Disable Extended Result Codes | |
1945 | ** METHOD: sqlite3 | |
1946 | ** | |
1947 | ** ^The sqlite3_extended_result_codes() routine enables or disables the | |
1948 | ** [extended result codes] feature of SQLite. ^The extended result | |
1949 | ** codes are disabled by default for historical compatibility. | |
1950 | */ | |
1951 | SQLITE_API int SQLITE_STDCALL sqlite3_extended_result_codes(sqlite3*, int onoff); | |
1952 | ||
1953 | /* | |
1954 | ** CAPI3REF: Last Insert Rowid | |
1955 | ** METHOD: sqlite3 | |
5783a860 | 1956 | ** |
08b809f9 EM |
1957 | ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) |
1958 | ** has a unique 64-bit signed | |
1959 | ** integer key called the [ROWID | "rowid"]. ^The rowid is always available | |
1960 | ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those | |
1961 | ** names are not also used by explicitly declared columns. ^If | |
1962 | ** the table has a column of type [INTEGER PRIMARY KEY] then that column | |
1963 | ** is another alias for the rowid. | |
5783a860 | 1964 | ** |
08b809f9 EM |
1965 | ** ^The sqlite3_last_insert_rowid(D) interface returns the [rowid] of the |
1966 | ** most recent successful [INSERT] into a rowid table or [virtual table] | |
1967 | ** on database connection D. | |
1968 | ** ^Inserts into [WITHOUT ROWID] tables are not recorded. | |
1969 | ** ^If no successful [INSERT]s into rowid tables | |
1970 | ** have ever occurred on the database connection D, | |
1971 | ** then sqlite3_last_insert_rowid(D) returns zero. | |
1972 | ** | |
1973 | ** ^(If an [INSERT] occurs within a trigger or within a [virtual table] | |
1974 | ** method, then this routine will return the [rowid] of the inserted | |
1975 | ** row as long as the trigger or virtual table method is running. | |
1976 | ** But once the trigger or virtual table method ends, the value returned | |
1977 | ** by this routine reverts to what it was before the trigger or virtual | |
1978 | ** table method began.)^ | |
1979 | ** | |
1980 | ** ^An [INSERT] that fails due to a constraint violation is not a | |
1981 | ** successful [INSERT] and does not change the value returned by this | |
1982 | ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, | |
5783a860 | 1983 | ** and INSERT OR ABORT make no changes to the return value of this |
08b809f9 | 1984 | ** routine when their insertion fails. ^(When INSERT OR REPLACE |
5783a860 AC |
1985 | ** encounters a constraint violation, it does not fail. The |
1986 | ** INSERT continues to completion after deleting rows that caused | |
1987 | ** the constraint problem so INSERT OR REPLACE will always change | |
08b809f9 | 1988 | ** the return value of this interface.)^ |
5783a860 | 1989 | ** |
08b809f9 | 1990 | ** ^For the purposes of this routine, an [INSERT] is considered to |
5783a860 AC |
1991 | ** be successful even if it is subsequently rolled back. |
1992 | ** | |
08b809f9 EM |
1993 | ** This function is accessible to SQL statements via the |
1994 | ** [last_insert_rowid() SQL function]. | |
1995 | ** | |
1996 | ** If a separate thread performs a new [INSERT] on the same | |
1997 | ** database connection while the [sqlite3_last_insert_rowid()] | |
1998 | ** function is running and thus changes the last insert [rowid], | |
1999 | ** then the value returned by [sqlite3_last_insert_rowid()] is | |
2000 | ** unpredictable and might not equal either the old or the new | |
2001 | ** last insert [rowid]. | |
2002 | */ | |
2003 | SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_last_insert_rowid(sqlite3*); | |
2004 | ||
2005 | /* | |
2006 | ** CAPI3REF: Count The Number Of Rows Modified | |
2007 | ** METHOD: sqlite3 | |
2008 | ** | |
2009 | ** ^This function returns the number of rows modified, inserted or | |
2010 | ** deleted by the most recently completed INSERT, UPDATE or DELETE | |
2011 | ** statement on the database connection specified by the only parameter. | |
2012 | ** ^Executing any other type of SQL statement does not modify the value | |
2013 | ** returned by this function. | |
2014 | ** | |
2015 | ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are | |
2016 | ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], | |
2017 | ** [foreign key actions] or [REPLACE] constraint resolution are not counted. | |
2018 | ** | |
2019 | ** Changes to a view that are intercepted by | |
2020 | ** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value | |
2021 | ** returned by sqlite3_changes() immediately after an INSERT, UPDATE or | |
2022 | ** DELETE statement run on a view is always zero. Only changes made to real | |
2023 | ** tables are counted. | |
2024 | ** | |
2025 | ** Things are more complicated if the sqlite3_changes() function is | |
2026 | ** executed while a trigger program is running. This may happen if the | |
2027 | ** program uses the [changes() SQL function], or if some other callback | |
2028 | ** function invokes sqlite3_changes() directly. Essentially: | |
2029 | ** | |
2030 | ** <ul> | |
2031 | ** <li> ^(Before entering a trigger program the value returned by | |
2032 | ** sqlite3_changes() function is saved. After the trigger program | |
2033 | ** has finished, the original value is restored.)^ | |
2034 | ** | |
2035 | ** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE | |
2036 | ** statement sets the value returned by sqlite3_changes() | |
2037 | ** upon completion as normal. Of course, this value will not include | |
2038 | ** any changes performed by sub-triggers, as the sqlite3_changes() | |
2039 | ** value will be saved and restored after each sub-trigger has run.)^ | |
2040 | ** </ul> | |
2041 | ** | |
2042 | ** ^This means that if the changes() SQL function (or similar) is used | |
2043 | ** by the first INSERT, UPDATE or DELETE statement within a trigger, it | |
2044 | ** returns the value as set when the calling statement began executing. | |
2045 | ** ^If it is used by the second or subsequent such statement within a trigger | |
2046 | ** program, the value returned reflects the number of rows modified by the | |
2047 | ** previous INSERT, UPDATE or DELETE statement within the same trigger. | |
2048 | ** | |
2049 | ** See also the [sqlite3_total_changes()] interface, the | |
2050 | ** [count_changes pragma], and the [changes() SQL function]. | |
2051 | ** | |
2052 | ** If a separate thread makes changes on the same database connection | |
2053 | ** while [sqlite3_changes()] is running then the value returned | |
2054 | ** is unpredictable and not meaningful. | |
2055 | */ | |
2056 | SQLITE_API int SQLITE_STDCALL sqlite3_changes(sqlite3*); | |
2057 | ||
2058 | /* | |
2059 | ** CAPI3REF: Total Number Of Rows Modified | |
2060 | ** METHOD: sqlite3 | |
2061 | ** | |
2062 | ** ^This function returns the total number of rows inserted, modified or | |
2063 | ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed | |
2064 | ** since the database connection was opened, including those executed as | |
2065 | ** part of trigger programs. ^Executing any other type of SQL statement | |
2066 | ** does not affect the value returned by sqlite3_total_changes(). | |
2067 | ** | |
2068 | ** ^Changes made as part of [foreign key actions] are included in the | |
2069 | ** count, but those made as part of REPLACE constraint resolution are | |
2070 | ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers | |
2071 | ** are not counted. | |
2072 | ** | |
2073 | ** See also the [sqlite3_changes()] interface, the | |
2074 | ** [count_changes pragma], and the [total_changes() SQL function]. | |
2075 | ** | |
2076 | ** If a separate thread makes changes on the same database connection | |
2077 | ** while [sqlite3_total_changes()] is running then the value | |
2078 | ** returned is unpredictable and not meaningful. | |
2079 | */ | |
2080 | SQLITE_API int SQLITE_STDCALL sqlite3_total_changes(sqlite3*); | |
2081 | ||
2082 | /* | |
2083 | ** CAPI3REF: Interrupt A Long-Running Query | |
2084 | ** METHOD: sqlite3 | |
2085 | ** | |
2086 | ** ^This function causes any pending database operation to abort and | |
5783a860 AC |
2087 | ** return at its earliest opportunity. This routine is typically |
2088 | ** called in response to a user action such as pressing "Cancel" | |
2089 | ** or Ctrl-C where the user wants a long query operation to halt | |
2090 | ** immediately. | |
2091 | ** | |
08b809f9 | 2092 | ** ^It is safe to call this routine from a thread different from the |
5783a860 | 2093 | ** thread that is currently running the database operation. But it |
08b809f9 | 2094 | ** is not safe to call this routine with a [database connection] that |
5783a860 AC |
2095 | ** is closed or might close before sqlite3_interrupt() returns. |
2096 | ** | |
08b809f9 EM |
2097 | ** ^If an SQL operation is very nearly finished at the time when |
2098 | ** sqlite3_interrupt() is called, then it might not have an opportunity | |
2099 | ** to be interrupted and might continue to completion. | |
2100 | ** | |
2101 | ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. | |
2102 | ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE | |
2103 | ** that is inside an explicit transaction, then the entire transaction | |
2104 | ** will be rolled back automatically. | |
2105 | ** | |
2106 | ** ^The sqlite3_interrupt(D) call is in effect until all currently running | |
2107 | ** SQL statements on [database connection] D complete. ^Any new SQL statements | |
2108 | ** that are started after the sqlite3_interrupt() call and before the | |
2109 | ** running statements reaches zero are interrupted as if they had been | |
2110 | ** running prior to the sqlite3_interrupt() call. ^New SQL statements | |
2111 | ** that are started after the running statement count reaches zero are | |
2112 | ** not effected by the sqlite3_interrupt(). | |
2113 | ** ^A call to sqlite3_interrupt(D) that occurs when there are no running | |
2114 | ** SQL statements is a no-op and has no effect on SQL statements | |
2115 | ** that are started after the sqlite3_interrupt() call returns. | |
2116 | ** | |
2117 | ** If the database connection closes while [sqlite3_interrupt()] | |
2118 | ** is running then bad things will likely happen. | |
5783a860 | 2119 | */ |
08b809f9 | 2120 | SQLITE_API void SQLITE_STDCALL sqlite3_interrupt(sqlite3*); |
5783a860 AC |
2121 | |
2122 | /* | |
08b809f9 | 2123 | ** CAPI3REF: Determine If An SQL Statement Is Complete |
5783a860 | 2124 | ** |
08b809f9 EM |
2125 | ** These routines are useful during command-line input to determine if the |
2126 | ** currently entered text seems to form a complete SQL statement or | |
5783a860 | 2127 | ** if additional input is needed before sending the text into |
08b809f9 EM |
2128 | ** SQLite for parsing. ^These routines return 1 if the input string |
2129 | ** appears to be a complete SQL statement. ^A statement is judged to be | |
2130 | ** complete if it ends with a semicolon token and is not a prefix of a | |
2131 | ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within | |
5783a860 AC |
2132 | ** string literals or quoted identifier names or comments are not |
2133 | ** independent tokens (they are part of the token in which they are | |
08b809f9 EM |
2134 | ** embedded) and thus do not count as a statement terminator. ^Whitespace |
2135 | ** and comments that follow the final semicolon are ignored. | |
5783a860 | 2136 | ** |
08b809f9 EM |
2137 | ** ^These routines return 0 if the statement is incomplete. ^If a |
2138 | ** memory allocation fails, then SQLITE_NOMEM is returned. | |
5783a860 | 2139 | ** |
08b809f9 EM |
2140 | ** ^These routines do not parse the SQL statements thus |
2141 | ** will not detect syntactically incorrect SQL. | |
5783a860 | 2142 | ** |
08b809f9 EM |
2143 | ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior |
2144 | ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked | |
2145 | ** automatically by sqlite3_complete16(). If that initialization fails, | |
2146 | ** then the return value from sqlite3_complete16() will be non-zero | |
2147 | ** regardless of whether or not the input SQL is complete.)^ | |
5783a860 | 2148 | ** |
08b809f9 EM |
2149 | ** The input to [sqlite3_complete()] must be a zero-terminated |
2150 | ** UTF-8 string. | |
5783a860 | 2151 | ** |
08b809f9 EM |
2152 | ** The input to [sqlite3_complete16()] must be a zero-terminated |
2153 | ** UTF-16 string in native byte order. | |
5783a860 | 2154 | */ |
08b809f9 EM |
2155 | SQLITE_API int SQLITE_STDCALL sqlite3_complete(const char *sql); |
2156 | SQLITE_API int SQLITE_STDCALL sqlite3_complete16(const void *sql); | |
5783a860 AC |
2157 | |
2158 | /* | |
08b809f9 EM |
2159 | ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors |
2160 | ** KEYWORDS: {busy-handler callback} {busy handler} | |
2161 | ** METHOD: sqlite3 | |
2162 | ** | |
2163 | ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X | |
2164 | ** that might be invoked with argument P whenever | |
2165 | ** an attempt is made to access a database table associated with | |
2166 | ** [database connection] D when another thread | |
2167 | ** or process has the table locked. | |
2168 | ** The sqlite3_busy_handler() interface is used to implement | |
2169 | ** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. | |
2170 | ** | |
2171 | ** ^If the busy callback is NULL, then [SQLITE_BUSY] | |
2172 | ** is returned immediately upon encountering the lock. ^If the busy callback | |
2173 | ** is not NULL, then the callback might be invoked with two arguments. | |
2174 | ** | |
2175 | ** ^The first argument to the busy handler is a copy of the void* pointer which | |
2176 | ** is the third argument to sqlite3_busy_handler(). ^The second argument to | |
2177 | ** the busy handler callback is the number of times that the busy handler has | |
2178 | ** been invoked previously for the same locking event. ^If the | |
5783a860 | 2179 | ** busy callback returns 0, then no additional attempts are made to |
08b809f9 EM |
2180 | ** access the database and [SQLITE_BUSY] is returned |
2181 | ** to the application. | |
2182 | ** ^If the callback returns non-zero, then another attempt | |
2183 | ** is made to access the database and the cycle repeats. | |
2184 | ** | |
2185 | ** The presence of a busy handler does not guarantee that it will be invoked | |
2186 | ** when there is lock contention. ^If SQLite determines that invoking the busy | |
2187 | ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] | |
2188 | ** to the application instead of invoking the | |
5783a860 AC |
2189 | ** busy handler. |
2190 | ** Consider a scenario where one process is holding a read lock that | |
2191 | ** it is trying to promote to a reserved lock and | |
2192 | ** a second process is holding a reserved lock that it is trying | |
2193 | ** to promote to an exclusive lock. The first process cannot proceed | |
2194 | ** because it is blocked by the second and the second process cannot | |
2195 | ** proceed because it is blocked by the first. If both processes | |
2196 | ** invoke the busy handlers, neither will make any progress. Therefore, | |
2197 | ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this | |
2198 | ** will induce the first process to release its read lock and allow | |
2199 | ** the second process to proceed. | |
2200 | ** | |
08b809f9 EM |
2201 | ** ^The default busy callback is NULL. |
2202 | ** | |
2203 | ** ^(There can only be a single busy handler defined for each | |
2204 | ** [database connection]. Setting a new busy handler clears any | |
2205 | ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] | |
2206 | ** or evaluating [PRAGMA busy_timeout=N] will change the | |
2207 | ** busy handler and thus clear any previously set busy handler. | |
2208 | ** | |
2209 | ** The busy callback should not take any actions which modify the | |
2210 | ** database connection that invoked the busy handler. In other words, | |
2211 | ** the busy handler is not reentrant. Any such actions | |
2212 | ** result in undefined behavior. | |
2213 | ** | |
2214 | ** A busy handler must not close the database connection | |
2215 | ** or [prepared statement] that invoked the busy handler. | |
5783a860 | 2216 | */ |
08b809f9 | 2217 | SQLITE_API int SQLITE_STDCALL sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*); |
5783a860 AC |
2218 | |
2219 | /* | |
08b809f9 EM |
2220 | ** CAPI3REF: Set A Busy Timeout |
2221 | ** METHOD: sqlite3 | |
5783a860 | 2222 | ** |
08b809f9 EM |
2223 | ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps |
2224 | ** for a specified amount of time when a table is locked. ^The handler | |
2225 | ** will sleep multiple times until at least "ms" milliseconds of sleeping | |
2226 | ** have accumulated. ^After at least "ms" milliseconds of sleeping, | |
2227 | ** the handler returns 0 which causes [sqlite3_step()] to return | |
2228 | ** [SQLITE_BUSY]. | |
5783a860 | 2229 | ** |
08b809f9 | 2230 | ** ^Calling this routine with an argument less than or equal to zero |
5783a860 AC |
2231 | ** turns off all busy handlers. |
2232 | ** | |
08b809f9 EM |
2233 | ** ^(There can only be a single busy handler for a particular |
2234 | ** [database connection] at any given moment. If another busy handler | |
2235 | ** was defined (using [sqlite3_busy_handler()]) prior to calling | |
2236 | ** this routine, that other busy handler is cleared.)^ | |
5783a860 | 2237 | ** |
08b809f9 | 2238 | ** See also: [PRAGMA busy_timeout] |
5783a860 | 2239 | */ |
08b809f9 | 2240 | SQLITE_API int SQLITE_STDCALL sqlite3_busy_timeout(sqlite3*, int ms); |
5783a860 AC |
2241 | |
2242 | /* | |
08b809f9 EM |
2243 | ** CAPI3REF: Convenience Routines For Running Queries |
2244 | ** METHOD: sqlite3 | |
2245 | ** | |
2246 | ** This is a legacy interface that is preserved for backwards compatibility. | |
2247 | ** Use of this interface is not recommended. | |
5783a860 AC |
2248 | ** |
2249 | ** Definition: A <b>result table</b> is memory data structure created by the | |
2250 | ** [sqlite3_get_table()] interface. A result table records the | |
2251 | ** complete query results from one or more queries. | |
2252 | ** | |
2253 | ** The table conceptually has a number of rows and columns. But | |
2254 | ** these numbers are not part of the result table itself. These | |
2255 | ** numbers are obtained separately. Let N be the number of rows | |
2256 | ** and M be the number of columns. | |
2257 | ** | |
08b809f9 EM |
2258 | ** A result table is an array of pointers to zero-terminated UTF-8 strings. |
2259 | ** There are (N+1)*M elements in the array. The first M pointers point | |
2260 | ** to zero-terminated strings that contain the names of the columns. | |
2261 | ** The remaining entries all point to query results. NULL values result | |
2262 | ** in NULL pointers. All other values are in their UTF-8 zero-terminated | |
2263 | ** string representation as returned by [sqlite3_column_text()]. | |
5783a860 | 2264 | ** |
08b809f9 | 2265 | ** A result table might consist of one or more memory allocations. |
5783a860 AC |
2266 | ** It is not safe to pass a result table directly to [sqlite3_free()]. |
2267 | ** A result table should be deallocated using [sqlite3_free_table()]. | |
2268 | ** | |
08b809f9 | 2269 | ** ^(As an example of the result table format, suppose a query result |
5783a860 AC |
2270 | ** is as follows: |
2271 | ** | |
2272 | ** <blockquote><pre> | |
2273 | ** Name | Age | |
2274 | ** ----------------------- | |
2275 | ** Alice | 43 | |
2276 | ** Bob | 28 | |
2277 | ** Cindy | 21 | |
2278 | ** </pre></blockquote> | |
2279 | ** | |
2280 | ** There are two column (M==2) and three rows (N==3). Thus the | |
2281 | ** result table has 8 entries. Suppose the result table is stored | |
2282 | ** in an array names azResult. Then azResult holds this content: | |
2283 | ** | |
2284 | ** <blockquote><pre> | |
2285 | ** azResult[0] = "Name"; | |
2286 | ** azResult[1] = "Age"; | |
2287 | ** azResult[2] = "Alice"; | |
2288 | ** azResult[3] = "43"; | |
2289 | ** azResult[4] = "Bob"; | |
2290 | ** azResult[5] = "28"; | |
2291 | ** azResult[6] = "Cindy"; | |
2292 | ** azResult[7] = "21"; | |
08b809f9 | 2293 | ** </pre></blockquote>)^ |
5783a860 | 2294 | ** |
08b809f9 | 2295 | ** ^The sqlite3_get_table() function evaluates one or more |
5783a860 | 2296 | ** semicolon-separated SQL statements in the zero-terminated UTF-8 |
08b809f9 | 2297 | ** string of its 2nd parameter and returns a result table to the |
5783a860 AC |
2298 | ** pointer given in its 3rd parameter. |
2299 | ** | |
08b809f9 EM |
2300 | ** After the application has finished with the result from sqlite3_get_table(), |
2301 | ** it must pass the result table pointer to sqlite3_free_table() in order to | |
2302 | ** release the memory that was malloced. Because of the way the | |
5783a860 | 2303 | ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling |
4094d2fa | 2304 | ** function must not try to call [sqlite3_free()] directly. Only |
5783a860 AC |
2305 | ** [sqlite3_free_table()] is able to release the memory properly and safely. |
2306 | ** | |
2307 | ** The sqlite3_get_table() interface is implemented as a wrapper around | |
2308 | ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access | |
2309 | ** to any internal data structures of SQLite. It uses only the public | |
2310 | ** interface defined here. As a consequence, errors that occur in the | |
2311 | ** wrapper layer outside of the internal [sqlite3_exec()] call are not | |
2312 | ** reflected in subsequent calls to [sqlite3_errcode()] or | |
2313 | ** [sqlite3_errmsg()]. | |
08b809f9 EM |
2314 | */ |
2315 | SQLITE_API int SQLITE_STDCALL sqlite3_get_table( | |
2316 | sqlite3 *db, /* An open database */ | |
2317 | const char *zSql, /* SQL to be evaluated */ | |
2318 | char ***pazResult, /* Results of the query */ | |
2319 | int *pnRow, /* Number of result rows written here */ | |
2320 | int *pnColumn, /* Number of result columns written here */ | |
2321 | char **pzErrmsg /* Error msg written here */ | |
5783a860 | 2322 | ); |
08b809f9 | 2323 | SQLITE_API void SQLITE_STDCALL sqlite3_free_table(char **result); |
5783a860 AC |
2324 | |
2325 | /* | |
08b809f9 | 2326 | ** CAPI3REF: Formatted String Printing Functions |
5783a860 | 2327 | ** |
08b809f9 | 2328 | ** These routines are work-alikes of the "printf()" family of functions |
5783a860 | 2329 | ** from the standard C library. |
08b809f9 EM |
2330 | ** These routines understand most of the common K&R formatting options, |
2331 | ** plus some additional non-standard formats, detailed below. | |
2332 | ** Note that some of the more obscure formatting options from recent | |
2333 | ** C-library standards are omitted from this implementation. | |
5783a860 | 2334 | ** |
08b809f9 | 2335 | ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their |
5783a860 AC |
2336 | ** results into memory obtained from [sqlite3_malloc()]. |
2337 | ** The strings returned by these two routines should be | |
08b809f9 | 2338 | ** released by [sqlite3_free()]. ^Both routines return a |
5783a860 AC |
2339 | ** NULL pointer if [sqlite3_malloc()] is unable to allocate enough |
2340 | ** memory to hold the resulting string. | |
2341 | ** | |
08b809f9 | 2342 | ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from |
5783a860 AC |
2343 | ** the standard C library. The result is written into the |
2344 | ** buffer supplied as the second parameter whose size is given by | |
2345 | ** the first parameter. Note that the order of the | |
08b809f9 | 2346 | ** first two parameters is reversed from snprintf().)^ This is an |
5783a860 | 2347 | ** historical accident that cannot be fixed without breaking |
08b809f9 | 2348 | ** backwards compatibility. ^(Note also that sqlite3_snprintf() |
5783a860 | 2349 | ** returns a pointer to its buffer instead of the number of |
08b809f9 | 2350 | ** characters actually written into the buffer.)^ We admit that |
5783a860 AC |
2351 | ** the number of characters written would be a more useful return |
2352 | ** value but we cannot change the implementation of sqlite3_snprintf() | |
2353 | ** now without breaking compatibility. | |
2354 | ** | |
08b809f9 EM |
2355 | ** ^As long as the buffer size is greater than zero, sqlite3_snprintf() |
2356 | ** guarantees that the buffer is always zero-terminated. ^The first | |
5783a860 AC |
2357 | ** parameter "n" is the total size of the buffer, including space for |
2358 | ** the zero terminator. So the longest string that can be completely | |
2359 | ** written will be n-1 characters. | |
2360 | ** | |
08b809f9 EM |
2361 | ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). |
2362 | ** | |
5783a860 AC |
2363 | ** These routines all implement some additional formatting |
2364 | ** options that are useful for constructing SQL statements. | |
08b809f9 EM |
2365 | ** All of the usual printf() formatting options apply. In addition, there |
2366 | ** is are "%q", "%Q", "%w" and "%z" options. | |
5783a860 | 2367 | ** |
08b809f9 | 2368 | ** ^(The %q option works like %s in that it substitutes a nul-terminated |
5783a860 | 2369 | ** string from the argument list. But %q also doubles every '\'' character. |
08b809f9 | 2370 | ** %q is designed for use inside a string literal.)^ By doubling each '\'' |
5783a860 AC |
2371 | ** character it escapes that character and allows it to be inserted into |
2372 | ** the string. | |
2373 | ** | |
08b809f9 | 2374 | ** For example, assume the string variable zText contains text as follows: |
5783a860 AC |
2375 | ** |
2376 | ** <blockquote><pre> | |
2377 | ** char *zText = "It's a happy day!"; | |
2378 | ** </pre></blockquote> | |
2379 | ** | |
2380 | ** One can use this text in an SQL statement as follows: | |
2381 | ** | |
2382 | ** <blockquote><pre> | |
2383 | ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); | |
2384 | ** sqlite3_exec(db, zSQL, 0, 0, 0); | |
2385 | ** sqlite3_free(zSQL); | |
2386 | ** </pre></blockquote> | |
2387 | ** | |
2388 | ** Because the %q format string is used, the '\'' character in zText | |
2389 | ** is escaped and the SQL generated is as follows: | |
2390 | ** | |
2391 | ** <blockquote><pre> | |
2392 | ** INSERT INTO table1 VALUES('It''s a happy day!') | |
2393 | ** </pre></blockquote> | |
2394 | ** | |
2395 | ** This is correct. Had we used %s instead of %q, the generated SQL | |
2396 | ** would have looked like this: | |
2397 | ** | |
2398 | ** <blockquote><pre> | |
2399 | ** INSERT INTO table1 VALUES('It's a happy day!'); | |
2400 | ** </pre></blockquote> | |
2401 | ** | |
08b809f9 EM |
2402 | ** This second example is an SQL syntax error. As a general rule you should |
2403 | ** always use %q instead of %s when inserting text into a string literal. | |
5783a860 | 2404 | ** |
08b809f9 EM |
2405 | ** ^(The %Q option works like %q except it also adds single quotes around |
2406 | ** the outside of the total string. Additionally, if the parameter in the | |
2407 | ** argument list is a NULL pointer, %Q substitutes the text "NULL" (without | |
2408 | ** single quotes).)^ So, for example, one could say: | |
5783a860 AC |
2409 | ** |
2410 | ** <blockquote><pre> | |
2411 | ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); | |
2412 | ** sqlite3_exec(db, zSQL, 0, 0, 0); | |
2413 | ** sqlite3_free(zSQL); | |
2414 | ** </pre></blockquote> | |
2415 | ** | |
2416 | ** The code above will render a correct SQL statement in the zSQL | |
2417 | ** variable even if the zText variable is a NULL pointer. | |
2418 | ** | |
08b809f9 EM |
2419 | ** ^(The "%w" formatting option is like "%q" except that it expects to |
2420 | ** be contained within double-quotes instead of single quotes, and it | |
2421 | ** escapes the double-quote character instead of the single-quote | |
2422 | ** character.)^ The "%w" formatting option is intended for safely inserting | |
2423 | ** table and column names into a constructed SQL statement. | |
4094d2fa | 2424 | ** |
08b809f9 EM |
2425 | ** ^(The "%z" formatting option works like "%s" but with the |
2426 | ** addition that after the string has been read and copied into | |
2427 | ** the result, [sqlite3_free()] is called on the input string.)^ | |
5783a860 | 2428 | */ |
08b809f9 EM |
2429 | SQLITE_API char *SQLITE_CDECL sqlite3_mprintf(const char*,...); |
2430 | SQLITE_API char *SQLITE_STDCALL sqlite3_vmprintf(const char*, va_list); | |
2431 | SQLITE_API char *SQLITE_CDECL sqlite3_snprintf(int,char*,const char*, ...); | |
2432 | SQLITE_API char *SQLITE_STDCALL sqlite3_vsnprintf(int,char*,const char*, va_list); | |
5783a860 AC |
2433 | |
2434 | /* | |
08b809f9 | 2435 | ** CAPI3REF: Memory Allocation Subsystem |
5783a860 | 2436 | ** |
08b809f9 | 2437 | ** The SQLite core uses these three routines for all of its own |
5783a860 AC |
2438 | ** internal memory allocation needs. "Core" in the previous sentence |
2439 | ** does not include operating-system specific VFS implementation. The | |
08b809f9 | 2440 | ** Windows VFS uses native malloc() and free() for some operations. |
5783a860 | 2441 | ** |
08b809f9 | 2442 | ** ^The sqlite3_malloc() routine returns a pointer to a block |
5783a860 | 2443 | ** of memory at least N bytes in length, where N is the parameter. |
08b809f9 EM |
2444 | ** ^If sqlite3_malloc() is unable to obtain sufficient free |
2445 | ** memory, it returns a NULL pointer. ^If the parameter N to | |
5783a860 AC |
2446 | ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns |
2447 | ** a NULL pointer. | |
2448 | ** | |
08b809f9 EM |
2449 | ** ^The sqlite3_malloc64(N) routine works just like |
2450 | ** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead | |
2451 | ** of a signed 32-bit integer. | |
2452 | ** | |
2453 | ** ^Calling sqlite3_free() with a pointer previously returned | |
5783a860 | 2454 | ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so |
08b809f9 | 2455 | ** that it might be reused. ^The sqlite3_free() routine is |
5783a860 AC |
2456 | ** a no-op if is called with a NULL pointer. Passing a NULL pointer |
2457 | ** to sqlite3_free() is harmless. After being freed, memory | |
2458 | ** should neither be read nor written. Even reading previously freed | |
2459 | ** memory might result in a segmentation fault or other severe error. | |
2460 | ** Memory corruption, a segmentation fault, or other severe error | |
2461 | ** might result if sqlite3_free() is called with a non-NULL pointer that | |
08b809f9 | 2462 | ** was not obtained from sqlite3_malloc() or sqlite3_realloc(). |
5783a860 | 2463 | ** |
08b809f9 EM |
2464 | ** ^The sqlite3_realloc(X,N) interface attempts to resize a |
2465 | ** prior memory allocation X to be at least N bytes. | |
2466 | ** ^If the X parameter to sqlite3_realloc(X,N) | |
5783a860 | 2467 | ** is a NULL pointer then its behavior is identical to calling |
08b809f9 EM |
2468 | ** sqlite3_malloc(N). |
2469 | ** ^If the N parameter to sqlite3_realloc(X,N) is zero or | |
5783a860 | 2470 | ** negative then the behavior is exactly the same as calling |
08b809f9 EM |
2471 | ** sqlite3_free(X). |
2472 | ** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation | |
2473 | ** of at least N bytes in size or NULL if insufficient memory is available. | |
2474 | ** ^If M is the size of the prior allocation, then min(N,M) bytes | |
5783a860 | 2475 | ** of the prior allocation are copied into the beginning of buffer returned |
08b809f9 EM |
2476 | ** by sqlite3_realloc(X,N) and the prior allocation is freed. |
2477 | ** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the | |
2478 | ** prior allocation is not freed. | |
2479 | ** | |
2480 | ** ^The sqlite3_realloc64(X,N) interfaces works the same as | |
2481 | ** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead | |
2482 | ** of a 32-bit signed integer. | |
2483 | ** | |
2484 | ** ^If X is a memory allocation previously obtained from sqlite3_malloc(), | |
2485 | ** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then | |
2486 | ** sqlite3_msize(X) returns the size of that memory allocation in bytes. | |
2487 | ** ^The value returned by sqlite3_msize(X) might be larger than the number | |
2488 | ** of bytes requested when X was allocated. ^If X is a NULL pointer then | |
2489 | ** sqlite3_msize(X) returns zero. If X points to something that is not | |
2490 | ** the beginning of memory allocation, or if it points to a formerly | |
2491 | ** valid memory allocation that has now been freed, then the behavior | |
2492 | ** of sqlite3_msize(X) is undefined and possibly harmful. | |
2493 | ** | |
2494 | ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), | |
2495 | ** sqlite3_malloc64(), and sqlite3_realloc64() | |
2496 | ** is always aligned to at least an 8 byte boundary, or to a | |
2497 | ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time | |
2498 | ** option is used. | |
5783a860 AC |
2499 | ** |
2500 | ** In SQLite version 3.5.0 and 3.5.1, it was possible to define | |
2501 | ** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in | |
2502 | ** implementation of these routines to be omitted. That capability | |
08b809f9 | 2503 | ** is no longer provided. Only built-in memory allocators can be used. |
5783a860 | 2504 | ** |
08b809f9 | 2505 | ** Prior to SQLite version 3.7.10, the Windows OS interface layer called |
5783a860 AC |
2506 | ** the system malloc() and free() directly when converting |
2507 | ** filenames between the UTF-8 encoding used by SQLite | |
08b809f9 EM |
2508 | ** and whatever filename encoding is used by the particular Windows |
2509 | ** installation. Memory allocation errors were detected, but | |
2510 | ** they were reported back as [SQLITE_CANTOPEN] or | |
5783a860 AC |
2511 | ** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. |
2512 | ** | |
08b809f9 EM |
2513 | ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] |
2514 | ** must be either NULL or else pointers obtained from a prior | |
2515 | ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have | |
2516 | ** not yet been released. | |
5783a860 | 2517 | ** |
08b809f9 EM |
2518 | ** The application must not read or write any part of |
2519 | ** a block of memory after it has been released using | |
2520 | ** [sqlite3_free()] or [sqlite3_realloc()]. | |
5783a860 | 2521 | */ |
08b809f9 EM |
2522 | SQLITE_API void *SQLITE_STDCALL sqlite3_malloc(int); |
2523 | SQLITE_API void *SQLITE_STDCALL sqlite3_malloc64(sqlite3_uint64); | |
2524 | SQLITE_API void *SQLITE_STDCALL sqlite3_realloc(void*, int); | |
2525 | SQLITE_API void *SQLITE_STDCALL sqlite3_realloc64(void*, sqlite3_uint64); | |
2526 | SQLITE_API void SQLITE_STDCALL sqlite3_free(void*); | |
2527 | SQLITE_API sqlite3_uint64 SQLITE_STDCALL sqlite3_msize(void*); | |
5783a860 AC |
2528 | |
2529 | /* | |
08b809f9 | 2530 | ** CAPI3REF: Memory Allocator Statistics |
5783a860 AC |
2531 | ** |
2532 | ** SQLite provides these two interfaces for reporting on the status | |
2533 | ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] | |
08b809f9 EM |
2534 | ** routines, which form the built-in memory allocation subsystem. |
2535 | ** | |
2536 | ** ^The [sqlite3_memory_used()] routine returns the number of bytes | |
2537 | ** of memory currently outstanding (malloced but not freed). | |
2538 | ** ^The [sqlite3_memory_highwater()] routine returns the maximum | |
2539 | ** value of [sqlite3_memory_used()] since the high-water mark | |
2540 | ** was last reset. ^The values returned by [sqlite3_memory_used()] and | |
2541 | ** [sqlite3_memory_highwater()] include any overhead | |
2542 | ** added by SQLite in its implementation of [sqlite3_malloc()], | |
2543 | ** but not overhead added by the any underlying system library | |
2544 | ** routines that [sqlite3_malloc()] may call. | |
2545 | ** | |
2546 | ** ^The memory high-water mark is reset to the current value of | |
2547 | ** [sqlite3_memory_used()] if and only if the parameter to | |
2548 | ** [sqlite3_memory_highwater()] is true. ^The value returned | |
2549 | ** by [sqlite3_memory_highwater(1)] is the high-water mark | |
2550 | ** prior to the reset. | |
5783a860 | 2551 | */ |
08b809f9 EM |
2552 | SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_memory_used(void); |
2553 | SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_memory_highwater(int resetFlag); | |
5783a860 AC |
2554 | |
2555 | /* | |
08b809f9 | 2556 | ** CAPI3REF: Pseudo-Random Number Generator |
5783a860 AC |
2557 | ** |
2558 | ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to | |
08b809f9 EM |
2559 | ** select random [ROWID | ROWIDs] when inserting new records into a table that |
2560 | ** already uses the largest possible [ROWID]. The PRNG is also used for | |
5783a860 | 2561 | ** the build-in random() and randomblob() SQL functions. This interface allows |
08b809f9 | 2562 | ** applications to access the same PRNG for other purposes. |
5783a860 | 2563 | ** |
08b809f9 EM |
2564 | ** ^A call to this routine stores N bytes of randomness into buffer P. |
2565 | ** ^The P parameter can be a NULL pointer. | |
5783a860 | 2566 | ** |
08b809f9 EM |
2567 | ** ^If this routine has not been previously called or if the previous |
2568 | ** call had N less than one or a NULL pointer for P, then the PRNG is | |
2569 | ** seeded using randomness obtained from the xRandomness method of | |
2570 | ** the default [sqlite3_vfs] object. | |
2571 | ** ^If the previous call to this routine had an N of 1 or more and a | |
2572 | ** non-NULL P then the pseudo-randomness is generated | |
5783a860 AC |
2573 | ** internally and without recourse to the [sqlite3_vfs] xRandomness |
2574 | ** method. | |
5783a860 | 2575 | */ |
08b809f9 | 2576 | SQLITE_API void SQLITE_STDCALL sqlite3_randomness(int N, void *P); |
5783a860 AC |
2577 | |
2578 | /* | |
08b809f9 EM |
2579 | ** CAPI3REF: Compile-Time Authorization Callbacks |
2580 | ** METHOD: sqlite3 | |
5783a860 | 2581 | ** |
08b809f9 | 2582 | ** ^This routine registers an authorizer callback with a particular |
5783a860 | 2583 | ** [database connection], supplied in the first argument. |
08b809f9 | 2584 | ** ^The authorizer callback is invoked as SQL statements are being compiled |
5783a860 | 2585 | ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], |
08b809f9 | 2586 | ** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various |
5783a860 AC |
2587 | ** points during the compilation process, as logic is being created |
2588 | ** to perform various actions, the authorizer callback is invoked to | |
08b809f9 | 2589 | ** see if those actions are allowed. ^The authorizer callback should |
5783a860 AC |
2590 | ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the |
2591 | ** specific action but allow the SQL statement to continue to be | |
2592 | ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be | |
08b809f9 | 2593 | ** rejected with an error. ^If the authorizer callback returns |
5783a860 | 2594 | ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] |
08b809f9 | 2595 | ** then the [sqlite3_prepare_v2()] or equivalent call that triggered |
5783a860 AC |
2596 | ** the authorizer will fail with an error message. |
2597 | ** | |
2598 | ** When the callback returns [SQLITE_OK], that means the operation | |
08b809f9 | 2599 | ** requested is ok. ^When the callback returns [SQLITE_DENY], the |
5783a860 AC |
2600 | ** [sqlite3_prepare_v2()] or equivalent call that triggered the |
2601 | ** authorizer will fail with an error message explaining that | |
08b809f9 EM |
2602 | ** access is denied. |
2603 | ** | |
2604 | ** ^The first parameter to the authorizer callback is a copy of the third | |
2605 | ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter | |
2606 | ** to the callback is an integer [SQLITE_COPY | action code] that specifies | |
2607 | ** the particular action to be authorized. ^The third through sixth parameters | |
2608 | ** to the callback are zero-terminated strings that contain additional | |
2609 | ** details about the action to be authorized. | |
2610 | ** | |
2611 | ** ^If the action code is [SQLITE_READ] | |
5783a860 AC |
2612 | ** and the callback returns [SQLITE_IGNORE] then the |
2613 | ** [prepared statement] statement is constructed to substitute | |
2614 | ** a NULL value in place of the table column that would have | |
2615 | ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] | |
2616 | ** return can be used to deny an untrusted user access to individual | |
2617 | ** columns of a table. | |
08b809f9 EM |
2618 | ** ^If the action code is [SQLITE_DELETE] and the callback returns |
2619 | ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the | |
2620 | ** [truncate optimization] is disabled and all rows are deleted individually. | |
5783a860 AC |
2621 | ** |
2622 | ** An authorizer is used when [sqlite3_prepare | preparing] | |
08b809f9 EM |
2623 | ** SQL statements from an untrusted source, to ensure that the SQL statements |
2624 | ** do not try to access data they are not allowed to see, or that they do not | |
2625 | ** try to execute malicious statements that damage the database. For | |
5783a860 AC |
2626 | ** example, an application may allow a user to enter arbitrary |
2627 | ** SQL queries for evaluation by a database. But the application does | |
2628 | ** not want the user to be able to make arbitrary changes to the | |
2629 | ** database. An authorizer could then be put in place while the | |
2630 | ** user-entered SQL is being [sqlite3_prepare | prepared] that | |
2631 | ** disallows everything except [SELECT] statements. | |
2632 | ** | |
2633 | ** Applications that need to process SQL from untrusted sources | |
2634 | ** might also consider lowering resource limits using [sqlite3_limit()] | |
2635 | ** and limiting database size using the [max_page_count] [PRAGMA] | |
2636 | ** in addition to using an authorizer. | |
2637 | ** | |
08b809f9 | 2638 | ** ^(Only a single authorizer can be in place on a database connection |
5783a860 | 2639 | ** at a time. Each call to sqlite3_set_authorizer overrides the |
08b809f9 | 2640 | ** previous call.)^ ^Disable the authorizer by installing a NULL callback. |
5783a860 AC |
2641 | ** The authorizer is disabled by default. |
2642 | ** | |
08b809f9 EM |
2643 | ** The authorizer callback must not do anything that will modify |
2644 | ** the database connection that invoked the authorizer callback. | |
2645 | ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their | |
2646 | ** database connections for the meaning of "modify" in this paragraph. | |
5783a860 | 2647 | ** |
08b809f9 EM |
2648 | ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the |
2649 | ** statement might be re-prepared during [sqlite3_step()] due to a | |
2650 | ** schema change. Hence, the application should ensure that the | |
2651 | ** correct authorizer callback remains in place during the [sqlite3_step()]. | |
5783a860 | 2652 | ** |
08b809f9 EM |
2653 | ** ^Note that the authorizer callback is invoked only during |
2654 | ** [sqlite3_prepare()] or its variants. Authorization is not | |
2655 | ** performed during statement evaluation in [sqlite3_step()], unless | |
2656 | ** as stated in the previous paragraph, sqlite3_step() invokes | |
2657 | ** sqlite3_prepare_v2() to reprepare a statement after a schema change. | |
5783a860 | 2658 | */ |
08b809f9 | 2659 | SQLITE_API int SQLITE_STDCALL sqlite3_set_authorizer( |
5783a860 AC |
2660 | sqlite3*, |
2661 | int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), | |
2662 | void *pUserData | |
2663 | ); | |
2664 | ||
2665 | /* | |
08b809f9 | 2666 | ** CAPI3REF: Authorizer Return Codes |
5783a860 AC |
2667 | ** |
2668 | ** The [sqlite3_set_authorizer | authorizer callback function] must | |
2669 | ** return either [SQLITE_OK] or one of these two constants in order | |
2670 | ** to signal SQLite whether or not the action is permitted. See the | |
2671 | ** [sqlite3_set_authorizer | authorizer documentation] for additional | |
2672 | ** information. | |
08b809f9 EM |
2673 | ** |
2674 | ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] | |
2675 | ** returned from the [sqlite3_vtab_on_conflict()] interface. | |
5783a860 AC |
2676 | */ |
2677 | #define SQLITE_DENY 1 /* Abort the SQL statement with an error */ | |
2678 | #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ | |
2679 | ||
2680 | /* | |
08b809f9 | 2681 | ** CAPI3REF: Authorizer Action Codes |
5783a860 AC |
2682 | ** |
2683 | ** The [sqlite3_set_authorizer()] interface registers a callback function | |
08b809f9 | 2684 | ** that is invoked to authorize certain SQL statement actions. The |
5783a860 AC |
2685 | ** second parameter to the callback is an integer code that specifies |
2686 | ** what action is being authorized. These are the integer action codes that | |
2687 | ** the authorizer callback may be passed. | |
2688 | ** | |
4094d2fa | 2689 | ** These action code values signify what kind of operation is to be |
5783a860 AC |
2690 | ** authorized. The 3rd and 4th parameters to the authorization |
2691 | ** callback function will be parameters or NULL depending on which of these | |
08b809f9 | 2692 | ** codes is used as the second parameter. ^(The 5th parameter to the |
4094d2fa | 2693 | ** authorizer callback is the name of the database ("main", "temp", |
08b809f9 | 2694 | ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback |
5783a860 | 2695 | ** is the name of the inner-most trigger or view that is responsible for |
4094d2fa | 2696 | ** the access attempt or NULL if this access attempt is directly from |
5783a860 | 2697 | ** top-level SQL code. |
5783a860 AC |
2698 | */ |
2699 | /******************************************* 3rd ************ 4th ***********/ | |
2700 | #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ | |
2701 | #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ | |
2702 | #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ | |
2703 | #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ | |
2704 | #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ | |
2705 | #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ | |
2706 | #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ | |
2707 | #define SQLITE_CREATE_VIEW 8 /* View Name NULL */ | |
2708 | #define SQLITE_DELETE 9 /* Table Name NULL */ | |
2709 | #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ | |
2710 | #define SQLITE_DROP_TABLE 11 /* Table Name NULL */ | |
2711 | #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ | |
2712 | #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ | |
2713 | #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ | |
2714 | #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ | |
2715 | #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ | |
2716 | #define SQLITE_DROP_VIEW 17 /* View Name NULL */ | |
2717 | #define SQLITE_INSERT 18 /* Table Name NULL */ | |
2718 | #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ | |
2719 | #define SQLITE_READ 20 /* Table Name Column Name */ | |
2720 | #define SQLITE_SELECT 21 /* NULL NULL */ | |
08b809f9 | 2721 | #define SQLITE_TRANSACTION 22 /* Operation NULL */ |
5783a860 AC |
2722 | #define SQLITE_UPDATE 23 /* Table Name Column Name */ |
2723 | #define SQLITE_ATTACH 24 /* Filename NULL */ | |
2724 | #define SQLITE_DETACH 25 /* Database Name NULL */ | |
2725 | #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ | |
2726 | #define SQLITE_REINDEX 27 /* Index Name NULL */ | |
2727 | #define SQLITE_ANALYZE 28 /* Table Name NULL */ | |
2728 | #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ | |
2729 | #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ | |
08b809f9 EM |
2730 | #define SQLITE_FUNCTION 31 /* NULL Function Name */ |
2731 | #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ | |
5783a860 | 2732 | #define SQLITE_COPY 0 /* No longer used */ |
08b809f9 | 2733 | #define SQLITE_RECURSIVE 33 /* NULL NULL */ |
5783a860 AC |
2734 | |
2735 | /* | |
08b809f9 EM |
2736 | ** CAPI3REF: Tracing And Profiling Functions |
2737 | ** METHOD: sqlite3 | |
5783a860 AC |
2738 | ** |
2739 | ** These routines register callback functions that can be used for | |
2740 | ** tracing and profiling the execution of SQL statements. | |
2741 | ** | |
08b809f9 | 2742 | ** ^The callback function registered by sqlite3_trace() is invoked at |
5783a860 | 2743 | ** various times when an SQL statement is being run by [sqlite3_step()]. |
08b809f9 EM |
2744 | ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the |
2745 | ** SQL statement text as the statement first begins executing. | |
2746 | ** ^(Additional sqlite3_trace() callbacks might occur | |
2747 | ** as each triggered subprogram is entered. The callbacks for triggers | |
2748 | ** contain a UTF-8 SQL comment that identifies the trigger.)^ | |
4094d2fa | 2749 | ** |
08b809f9 EM |
2750 | ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit |
2751 | ** the length of [bound parameter] expansion in the output of sqlite3_trace(). | |
5783a860 | 2752 | ** |
08b809f9 EM |
2753 | ** ^The callback function registered by sqlite3_profile() is invoked |
2754 | ** as each SQL statement finishes. ^The profile callback contains | |
2755 | ** the original statement text and an estimate of wall-clock time | |
2756 | ** of how long that statement took to run. ^The profile callback | |
2757 | ** time is in units of nanoseconds, however the current implementation | |
2758 | ** is only capable of millisecond resolution so the six least significant | |
2759 | ** digits in the time are meaningless. Future versions of SQLite | |
2760 | ** might provide greater resolution on the profiler callback. The | |
2761 | ** sqlite3_profile() function is considered experimental and is | |
2762 | ** subject to change in future versions of SQLite. | |
5783a860 | 2763 | */ |
08b809f9 EM |
2764 | SQLITE_API void *SQLITE_STDCALL sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*); |
2765 | SQLITE_API SQLITE_EXPERIMENTAL void *SQLITE_STDCALL sqlite3_profile(sqlite3*, | |
5783a860 AC |
2766 | void(*xProfile)(void*,const char*,sqlite3_uint64), void*); |
2767 | ||
2768 | /* | |
08b809f9 EM |
2769 | ** CAPI3REF: Query Progress Callbacks |
2770 | ** METHOD: sqlite3 | |
5783a860 | 2771 | ** |
08b809f9 EM |
2772 | ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback |
2773 | ** function X to be invoked periodically during long running calls to | |
2774 | ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for | |
2775 | ** database connection D. An example use for this | |
5783a860 AC |
2776 | ** interface is to keep a GUI updated during a large query. |
2777 | ** | |
08b809f9 EM |
2778 | ** ^The parameter P is passed through as the only parameter to the |
2779 | ** callback function X. ^The parameter N is the approximate number of | |
2780 | ** [virtual machine instructions] that are evaluated between successive | |
2781 | ** invocations of the callback X. ^If N is less than one then the progress | |
2782 | ** handler is disabled. | |
5783a860 | 2783 | ** |
08b809f9 EM |
2784 | ** ^Only a single progress handler may be defined at one time per |
2785 | ** [database connection]; setting a new progress handler cancels the | |
2786 | ** old one. ^Setting parameter X to NULL disables the progress handler. | |
2787 | ** ^The progress handler is also disabled by setting N to a value less | |
2788 | ** than 1. | |
5783a860 | 2789 | ** |
08b809f9 EM |
2790 | ** ^If the progress callback returns non-zero, the operation is |
2791 | ** interrupted. This feature can be used to implement a | |
2792 | ** "Cancel" button on a GUI progress dialog box. | |
5783a860 | 2793 | ** |
08b809f9 EM |
2794 | ** The progress handler callback must not do anything that will modify |
2795 | ** the database connection that invoked the progress handler. | |
2796 | ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their | |
2797 | ** database connections for the meaning of "modify" in this paragraph. | |
5783a860 | 2798 | ** |
5783a860 | 2799 | */ |
08b809f9 | 2800 | SQLITE_API void SQLITE_STDCALL sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); |
5783a860 AC |
2801 | |
2802 | /* | |
08b809f9 EM |
2803 | ** CAPI3REF: Opening A New Database Connection |
2804 | ** CONSTRUCTOR: sqlite3 | |
2805 | ** | |
2806 | ** ^These routines open an SQLite database file as specified by the | |
2807 | ** filename argument. ^The filename argument is interpreted as UTF-8 for | |
2808 | ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte | |
2809 | ** order for sqlite3_open16(). ^(A [database connection] handle is usually | |
2810 | ** returned in *ppDb, even if an error occurs. The only exception is that | |
2811 | ** if SQLite is unable to allocate memory to hold the [sqlite3] object, | |
2812 | ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] | |
2813 | ** object.)^ ^(If the database is opened (and/or created) successfully, then | |
2814 | ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The | |
2815 | ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain | |
2816 | ** an English language description of the error following a failure of any | |
2817 | ** of the sqlite3_open() routines. | |
2818 | ** | |
2819 | ** ^The default encoding will be UTF-8 for databases created using | |
2820 | ** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases | |
2821 | ** created using sqlite3_open16() will be UTF-16 in the native byte order. | |
5783a860 AC |
2822 | ** |
2823 | ** Whether or not an error occurs when it is opened, resources | |
08b809f9 EM |
2824 | ** associated with the [database connection] handle should be released by |
2825 | ** passing it to [sqlite3_close()] when it is no longer required. | |
5783a860 | 2826 | ** |
08b809f9 EM |
2827 | ** The sqlite3_open_v2() interface works like sqlite3_open() |
2828 | ** except that it accepts two additional parameters for additional control | |
2829 | ** over the new database connection. ^(The flags parameter to | |
2830 | ** sqlite3_open_v2() can take one of | |
2831 | ** the following three values, optionally combined with the | |
2832 | ** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], | |
2833 | ** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ | |
5783a860 | 2834 | ** |
08b809f9 EM |
2835 | ** <dl> |
2836 | ** ^(<dt>[SQLITE_OPEN_READONLY]</dt> | |
2837 | ** <dd>The database is opened in read-only mode. If the database does not | |
2838 | ** already exist, an error is returned.</dd>)^ | |
2839 | ** | |
2840 | ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> | |
2841 | ** <dd>The database is opened for reading and writing if possible, or reading | |
2842 | ** only if the file is write protected by the operating system. In either | |
2843 | ** case the database must already exist, otherwise an error is returned.</dd>)^ | |
2844 | ** | |
2845 | ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> | |
2846 | ** <dd>The database is opened for reading and writing, and is created if | |
2847 | ** it does not already exist. This is the behavior that is always used for | |
2848 | ** sqlite3_open() and sqlite3_open16().</dd>)^ | |
2849 | ** </dl> | |
5783a860 | 2850 | ** |
08b809f9 EM |
2851 | ** If the 3rd parameter to sqlite3_open_v2() is not one of the |
2852 | ** combinations shown above optionally combined with other | |
2853 | ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] | |
2854 | ** then the behavior is undefined. | |
5783a860 | 2855 | ** |
08b809f9 EM |
2856 | ** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection |
2857 | ** opens in the multi-thread [threading mode] as long as the single-thread | |
2858 | ** mode has not been set at compile-time or start-time. ^If the | |
2859 | ** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens | |
2860 | ** in the serialized [threading mode] unless single-thread was | |
2861 | ** previously selected at compile-time or start-time. | |
2862 | ** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be | |
2863 | ** eligible to use [shared cache mode], regardless of whether or not shared | |
2864 | ** cache is enabled using [sqlite3_enable_shared_cache()]. ^The | |
2865 | ** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not | |
2866 | ** participate in [shared cache mode] even if it is enabled. | |
2867 | ** | |
2868 | ** ^The fourth parameter to sqlite3_open_v2() is the name of the | |
2869 | ** [sqlite3_vfs] object that defines the operating system interface that | |
2870 | ** the new database connection should use. ^If the fourth parameter is | |
2871 | ** a NULL pointer then the default [sqlite3_vfs] object is used. | |
2872 | ** | |
2873 | ** ^If the filename is ":memory:", then a private, temporary in-memory database | |
2874 | ** is created for the connection. ^This in-memory database will vanish when | |
2875 | ** the database connection is closed. Future versions of SQLite might | |
2876 | ** make use of additional special filenames that begin with the ":" character. | |
2877 | ** It is recommended that when a database filename actually does begin with | |
2878 | ** a ":" character you should prefix the filename with a pathname such as | |
2879 | ** "./" to avoid ambiguity. | |
2880 | ** | |
2881 | ** ^If the filename is an empty string, then a private, temporary | |
2882 | ** on-disk database will be created. ^This private database will be | |
2883 | ** automatically deleted as soon as the database connection is closed. | |
5783a860 | 2884 | ** |
08b809f9 EM |
2885 | ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> |
2886 | ** | |
2887 | ** ^If [URI filename] interpretation is enabled, and the filename argument | |
2888 | ** begins with "file:", then the filename is interpreted as a URI. ^URI | |
2889 | ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is | |
2890 | ** set in the fourth argument to sqlite3_open_v2(), or if it has | |
2891 | ** been enabled globally using the [SQLITE_CONFIG_URI] option with the | |
2892 | ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. | |
2893 | ** As of SQLite version 3.7.7, URI filename interpretation is turned off | |
2894 | ** by default, but future releases of SQLite might enable URI filename | |
2895 | ** interpretation by default. See "[URI filenames]" for additional | |
2896 | ** information. | |
5783a860 | 2897 | ** |
08b809f9 EM |
2898 | ** URI filenames are parsed according to RFC 3986. ^If the URI contains an |
2899 | ** authority, then it must be either an empty string or the string | |
2900 | ** "localhost". ^If the authority is not an empty string or "localhost", an | |
2901 | ** error is returned to the caller. ^The fragment component of a URI, if | |
2902 | ** present, is ignored. | |
2903 | ** | |
2904 | ** ^SQLite uses the path component of the URI as the name of the disk file | |
2905 | ** which contains the database. ^If the path begins with a '/' character, | |
2906 | ** then it is interpreted as an absolute path. ^If the path does not begin | |
2907 | ** with a '/' (meaning that the authority section is omitted from the URI) | |
2908 | ** then the path is interpreted as a relative path. | |
2909 | ** ^(On windows, the first component of an absolute path | |
2910 | ** is a drive specification (e.g. "C:").)^ | |
2911 | ** | |
2912 | ** [[core URI query parameters]] | |
2913 | ** The query component of a URI may contain parameters that are interpreted | |
2914 | ** either by SQLite itself, or by a [VFS | custom VFS implementation]. | |
2915 | ** SQLite and its built-in [VFSes] interpret the | |
2916 | ** following query parameters: | |
5783a860 | 2917 | ** |
08b809f9 EM |
2918 | ** <ul> |
2919 | ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of | |
2920 | ** a VFS object that provides the operating system interface that should | |
2921 | ** be used to access the database file on disk. ^If this option is set to | |
2922 | ** an empty string the default VFS object is used. ^Specifying an unknown | |
2923 | ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is | |
2924 | ** present, then the VFS specified by the option takes precedence over | |
2925 | ** the value passed as the fourth parameter to sqlite3_open_v2(). | |
2926 | ** | |
2927 | ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", | |
2928 | ** "rwc", or "memory". Attempting to set it to any other value is | |
2929 | ** an error)^. | |
2930 | ** ^If "ro" is specified, then the database is opened for read-only | |
2931 | ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the | |
2932 | ** third argument to sqlite3_open_v2(). ^If the mode option is set to | |
2933 | ** "rw", then the database is opened for read-write (but not create) | |
2934 | ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had | |
2935 | ** been set. ^Value "rwc" is equivalent to setting both | |
2936 | ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is | |
2937 | ** set to "memory" then a pure [in-memory database] that never reads | |
2938 | ** or writes from disk is used. ^It is an error to specify a value for | |
2939 | ** the mode parameter that is less restrictive than that specified by | |
2940 | ** the flags passed in the third parameter to sqlite3_open_v2(). | |
2941 | ** | |
2942 | ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or | |
2943 | ** "private". ^Setting it to "shared" is equivalent to setting the | |
2944 | ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to | |
2945 | ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is | |
2946 | ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. | |
2947 | ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in | |
2948 | ** a URI filename, its value overrides any behavior requested by setting | |
2949 | ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. | |
2950 | ** | |
2951 | ** <li> <b>psow</b>: ^The psow parameter indicates whether or not the | |
2952 | ** [powersafe overwrite] property does or does not apply to the | |
2953 | ** storage media on which the database file resides. | |
2954 | ** | |
2955 | ** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter | |
2956 | ** which if set disables file locking in rollback journal modes. This | |
2957 | ** is useful for accessing a database on a filesystem that does not | |
2958 | ** support locking. Caution: Database corruption might result if two | |
2959 | ** or more processes write to the same database and any one of those | |
2960 | ** processes uses nolock=1. | |
2961 | ** | |
2962 | ** <li> <b>immutable</b>: ^The immutable parameter is a boolean query | |
2963 | ** parameter that indicates that the database file is stored on | |
2964 | ** read-only media. ^When immutable is set, SQLite assumes that the | |
2965 | ** database file cannot be changed, even by a process with higher | |
2966 | ** privilege, and so the database is opened read-only and all locking | |
2967 | ** and change detection is disabled. Caution: Setting the immutable | |
2968 | ** property on a database file that does in fact change can result | |
2969 | ** in incorrect query results and/or [SQLITE_CORRUPT] errors. | |
2970 | ** See also: [SQLITE_IOCAP_IMMUTABLE]. | |
2971 | ** | |
2972 | ** </ul> | |
5783a860 | 2973 | ** |
08b809f9 EM |
2974 | ** ^Specifying an unknown parameter in the query component of a URI is not an |
2975 | ** error. Future versions of SQLite might understand additional query | |
2976 | ** parameters. See "[query parameters with special meaning to SQLite]" for | |
2977 | ** additional information. | |
5783a860 | 2978 | ** |
08b809f9 EM |
2979 | ** [[URI filename examples]] <h3>URI filename examples</h3> |
2980 | ** | |
2981 | ** <table border="1" align=center cellpadding=5> | |
2982 | ** <tr><th> URI filenames <th> Results | |
2983 | ** <tr><td> file:data.db <td> | |
2984 | ** Open the file "data.db" in the current directory. | |
2985 | ** <tr><td> file:/home/fred/data.db<br> | |
2986 | ** file:///home/fred/data.db <br> | |
2987 | ** file://localhost/home/fred/data.db <br> <td> | |
2988 | ** Open the database file "/home/fred/data.db". | |
2989 | ** <tr><td> file://darkstar/home/fred/data.db <td> | |
2990 | ** An error. "darkstar" is not a recognized authority. | |
2991 | ** <tr><td style="white-space:nowrap"> | |
2992 | ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db | |
2993 | ** <td> Windows only: Open the file "data.db" on fred's desktop on drive | |
2994 | ** C:. Note that the %20 escaping in this example is not strictly | |
2995 | ** necessary - space characters can be used literally | |
2996 | ** in URI filenames. | |
2997 | ** <tr><td> file:data.db?mode=ro&cache=private <td> | |
2998 | ** Open file "data.db" in the current directory for read-only access. | |
2999 | ** Regardless of whether or not shared-cache mode is enabled by | |
3000 | ** default, use a private cache. | |
3001 | ** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> | |
3002 | ** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" | |
3003 | ** that uses dot-files in place of posix advisory locking. | |
3004 | ** <tr><td> file:data.db?mode=readonly <td> | |
3005 | ** An error. "readonly" is not a valid option for the "mode" parameter. | |
3006 | ** </table> | |
5783a860 | 3007 | ** |
08b809f9 EM |
3008 | ** ^URI hexadecimal escape sequences (%HH) are supported within the path and |
3009 | ** query components of a URI. A hexadecimal escape sequence consists of a | |
3010 | ** percent sign - "%" - followed by exactly two hexadecimal digits | |
3011 | ** specifying an octet value. ^Before the path or query components of a | |
3012 | ** URI filename are interpreted, they are encoded using UTF-8 and all | |
3013 | ** hexadecimal escape sequences replaced by a single byte containing the | |
3014 | ** corresponding octet. If this process generates an invalid UTF-8 encoding, | |
3015 | ** the results are undefined. | |
3016 | ** | |
3017 | ** <b>Note to Windows users:</b> The encoding used for the filename argument | |
3018 | ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever | |
3019 | ** codepage is currently defined. Filenames containing international | |
3020 | ** characters must be converted to UTF-8 prior to passing them into | |
3021 | ** sqlite3_open() or sqlite3_open_v2(). | |
5783a860 | 3022 | ** |
08b809f9 EM |
3023 | ** <b>Note to Windows Runtime users:</b> The temporary directory must be set |
3024 | ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various | |
3025 | ** features that require the use of temporary files may fail. | |
5783a860 | 3026 | ** |
08b809f9 | 3027 | ** See also: [sqlite3_temp_directory] |
5783a860 | 3028 | */ |
08b809f9 | 3029 | SQLITE_API int SQLITE_STDCALL sqlite3_open( |
5783a860 AC |
3030 | const char *filename, /* Database filename (UTF-8) */ |
3031 | sqlite3 **ppDb /* OUT: SQLite db handle */ | |
3032 | ); | |
08b809f9 | 3033 | SQLITE_API int SQLITE_STDCALL sqlite3_open16( |
5783a860 AC |
3034 | const void *filename, /* Database filename (UTF-16) */ |
3035 | sqlite3 **ppDb /* OUT: SQLite db handle */ | |
3036 | ); | |
08b809f9 | 3037 | SQLITE_API int SQLITE_STDCALL sqlite3_open_v2( |
5783a860 AC |
3038 | const char *filename, /* Database filename (UTF-8) */ |
3039 | sqlite3 **ppDb, /* OUT: SQLite db handle */ | |
3040 | int flags, /* Flags */ | |
3041 | const char *zVfs /* Name of VFS module to use */ | |
3042 | ); | |
3043 | ||
3044 | /* | |
08b809f9 EM |
3045 | ** CAPI3REF: Obtain Values For URI Parameters |
3046 | ** | |
3047 | ** These are utility routines, useful to VFS implementations, that check | |
3048 | ** to see if a database file was a URI that contained a specific query | |
3049 | ** parameter, and if so obtains the value of that query parameter. | |
3050 | ** | |
3051 | ** If F is the database filename pointer passed into the xOpen() method of | |
3052 | ** a VFS implementation when the flags parameter to xOpen() has one or | |
3053 | ** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and | |
3054 | ** P is the name of the query parameter, then | |
3055 | ** sqlite3_uri_parameter(F,P) returns the value of the P | |
3056 | ** parameter if it exists or a NULL pointer if P does not appear as a | |
3057 | ** query parameter on F. If P is a query parameter of F | |
3058 | ** has no explicit value, then sqlite3_uri_parameter(F,P) returns | |
3059 | ** a pointer to an empty string. | |
3060 | ** | |
3061 | ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean | |
3062 | ** parameter and returns true (1) or false (0) according to the value | |
3063 | ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the | |
3064 | ** value of query parameter P is one of "yes", "true", or "on" in any | |
3065 | ** case or if the value begins with a non-zero number. The | |
3066 | ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of | |
3067 | ** query parameter P is one of "no", "false", or "off" in any case or | |
3068 | ** if the value begins with a numeric zero. If P is not a query | |
3069 | ** parameter on F or if the value of P is does not match any of the | |
3070 | ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). | |
3071 | ** | |
3072 | ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a | |
3073 | ** 64-bit signed integer and returns that integer, or D if P does not | |
3074 | ** exist. If the value of P is something other than an integer, then | |
3075 | ** zero is returned. | |
3076 | ** | |
3077 | ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and | |
3078 | ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and | |
3079 | ** is not a database file pathname pointer that SQLite passed into the xOpen | |
3080 | ** VFS method, then the behavior of this routine is undefined and probably | |
3081 | ** undesirable. | |
3082 | */ | |
3083 | SQLITE_API const char *SQLITE_STDCALL sqlite3_uri_parameter(const char *zFilename, const char *zParam); | |
3084 | SQLITE_API int SQLITE_STDCALL sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); | |
3085 | SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_uri_int64(const char*, const char*, sqlite3_int64); | |
3086 | ||
3087 | ||
3088 | /* | |
3089 | ** CAPI3REF: Error Codes And Messages | |
3090 | ** METHOD: sqlite3 | |
3091 | ** | |
3092 | ** ^If the most recent sqlite3_* API call associated with | |
3093 | ** [database connection] D failed, then the sqlite3_errcode(D) interface | |
3094 | ** returns the numeric [result code] or [extended result code] for that | |
3095 | ** API call. | |
3096 | ** If the most recent API call was successful, | |
3097 | ** then the return value from sqlite3_errcode() is undefined. | |
3098 | ** ^The sqlite3_extended_errcode() | |
3099 | ** interface is the same except that it always returns the | |
3100 | ** [extended result code] even when extended result codes are | |
3101 | ** disabled. | |
3102 | ** | |
3103 | ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language | |
3104 | ** text that describes the error, as either UTF-8 or UTF-16 respectively. | |
3105 | ** ^(Memory to hold the error message string is managed internally. | |
3106 | ** The application does not need to worry about freeing the result. | |
5783a860 | 3107 | ** However, the error string might be overwritten or deallocated by |
08b809f9 EM |
3108 | ** subsequent calls to other SQLite interface functions.)^ |
3109 | ** | |
3110 | ** ^The sqlite3_errstr() interface returns the English-language text | |
3111 | ** that describes the [result code], as UTF-8. | |
3112 | ** ^(Memory to hold the error message string is managed internally | |
3113 | ** and must not be freed by the application)^. | |
3114 | ** | |
3115 | ** When the serialized [threading mode] is in use, it might be the | |
3116 | ** case that a second error occurs on a separate thread in between | |
3117 | ** the time of the first error and the call to these interfaces. | |
3118 | ** When that happens, the second error will be reported since these | |
3119 | ** interfaces always report the most recent result. To avoid | |
3120 | ** this, each thread can obtain exclusive use of the [database connection] D | |
3121 | ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning | |
3122 | ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after | |
3123 | ** all calls to the interfaces listed here are completed. | |
3124 | ** | |
3125 | ** If an interface fails with SQLITE_MISUSE, that means the interface | |
3126 | ** was invoked incorrectly by the application. In that case, the | |
3127 | ** error code and message may or may not be set. | |
5783a860 | 3128 | */ |
08b809f9 EM |
3129 | SQLITE_API int SQLITE_STDCALL sqlite3_errcode(sqlite3 *db); |
3130 | SQLITE_API int SQLITE_STDCALL sqlite3_extended_errcode(sqlite3 *db); | |
3131 | SQLITE_API const char *SQLITE_STDCALL sqlite3_errmsg(sqlite3*); | |
3132 | SQLITE_API const void *SQLITE_STDCALL sqlite3_errmsg16(sqlite3*); | |
3133 | SQLITE_API const char *SQLITE_STDCALL sqlite3_errstr(int); | |
5783a860 AC |
3134 | |
3135 | /* | |
08b809f9 | 3136 | ** CAPI3REF: Prepared Statement Object |
5783a860 AC |
3137 | ** KEYWORDS: {prepared statement} {prepared statements} |
3138 | ** | |
08b809f9 EM |
3139 | ** An instance of this object represents a single SQL statement that |
3140 | ** has been compiled into binary form and is ready to be evaluated. | |
3141 | ** | |
3142 | ** Think of each SQL statement as a separate computer program. The | |
3143 | ** original SQL text is source code. A prepared statement object | |
3144 | ** is the compiled object code. All SQL must be converted into a | |
3145 | ** prepared statement before it can be run. | |
4094d2fa | 3146 | ** |
08b809f9 | 3147 | ** The life-cycle of a prepared statement object usually goes like this: |
5783a860 AC |
3148 | ** |
3149 | ** <ol> | |
08b809f9 EM |
3150 | ** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. |
3151 | ** <li> Bind values to [parameters] using the sqlite3_bind_*() | |
3152 | ** interfaces. | |
5783a860 | 3153 | ** <li> Run the SQL by calling [sqlite3_step()] one or more times. |
08b809f9 | 3154 | ** <li> Reset the prepared statement using [sqlite3_reset()] then go back |
5783a860 AC |
3155 | ** to step 2. Do this zero or more times. |
3156 | ** <li> Destroy the object using [sqlite3_finalize()]. | |
3157 | ** </ol> | |
5783a860 AC |
3158 | */ |
3159 | typedef struct sqlite3_stmt sqlite3_stmt; | |
3160 | ||
3161 | /* | |
08b809f9 EM |
3162 | ** CAPI3REF: Run-time Limits |
3163 | ** METHOD: sqlite3 | |
5783a860 | 3164 | ** |
08b809f9 | 3165 | ** ^(This interface allows the size of various constructs to be limited |
5783a860 AC |
3166 | ** on a connection by connection basis. The first parameter is the |
3167 | ** [database connection] whose limit is to be set or queried. The | |
3168 | ** second parameter is one of the [limit categories] that define a | |
3169 | ** class of constructs to be size limited. The third parameter is the | |
08b809f9 EM |
3170 | ** new limit for that construct.)^ |
3171 | ** | |
3172 | ** ^If the new limit is a negative number, the limit is unchanged. | |
3173 | ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a | |
3174 | ** [limits | hard upper bound] | |
3175 | ** set at compile-time by a C preprocessor macro called | |
3176 | ** [limits | SQLITE_MAX_<i>NAME</i>]. | |
3177 | ** (The "_LIMIT_" in the name is changed to "_MAX_".))^ | |
3178 | ** ^Attempts to increase a limit above its hard upper bound are | |
3179 | ** silently truncated to the hard upper bound. | |
3180 | ** | |
3181 | ** ^Regardless of whether or not the limit was changed, the | |
3182 | ** [sqlite3_limit()] interface returns the prior value of the limit. | |
3183 | ** ^Hence, to find the current value of a limit without changing it, | |
3184 | ** simply invoke this interface with the third parameter set to -1. | |
3185 | ** | |
3186 | ** Run-time limits are intended for use in applications that manage | |
5783a860 AC |
3187 | ** both their own internal database and also databases that are controlled |
3188 | ** by untrusted external sources. An example application might be a | |
08b809f9 EM |
3189 | ** web browser that has its own databases for storing history and |
3190 | ** separate databases controlled by JavaScript applications downloaded | |
3191 | ** off the Internet. The internal databases can be given the | |
5783a860 AC |
3192 | ** large, default limits. Databases managed by external sources can |
3193 | ** be given much smaller limits designed to prevent a denial of service | |
08b809f9 | 3194 | ** attack. Developers might also want to use the [sqlite3_set_authorizer()] |
5783a860 AC |
3195 | ** interface to further control untrusted SQL. The size of the database |
3196 | ** created by an untrusted script can be contained using the | |
3197 | ** [max_page_count] [PRAGMA]. | |
3198 | ** | |
08b809f9 | 3199 | ** New run-time limit categories may be added in future releases. |
5783a860 | 3200 | */ |
08b809f9 | 3201 | SQLITE_API int SQLITE_STDCALL sqlite3_limit(sqlite3*, int id, int newVal); |
5783a860 AC |
3202 | |
3203 | /* | |
08b809f9 EM |
3204 | ** CAPI3REF: Run-Time Limit Categories |
3205 | ** KEYWORDS: {limit category} {*limit categories} | |
4094d2fa | 3206 | ** |
08b809f9 EM |
3207 | ** These constants define various performance limits |
3208 | ** that can be lowered at run-time using [sqlite3_limit()]. | |
3209 | ** The synopsis of the meanings of the various limits is shown below. | |
3210 | ** Additional information is available at [limits | Limits in SQLite]. | |
5783a860 AC |
3211 | ** |
3212 | ** <dl> | |
08b809f9 EM |
3213 | ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> |
3214 | ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ | |
5783a860 | 3215 | ** |
08b809f9 EM |
3216 | ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> |
3217 | ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ | |
5783a860 | 3218 | ** |
08b809f9 | 3219 | ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> |
5783a860 | 3220 | ** <dd>The maximum number of columns in a table definition or in the |
08b809f9 EM |
3221 | ** result set of a [SELECT] or the maximum number of columns in an index |
3222 | ** or in an ORDER BY or GROUP BY clause.</dd>)^ | |
5783a860 | 3223 | ** |
08b809f9 EM |
3224 | ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> |
3225 | ** <dd>The maximum depth of the parse tree on any expression.</dd>)^ | |
5783a860 | 3226 | ** |
08b809f9 EM |
3227 | ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> |
3228 | ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ | |
5783a860 | 3229 | ** |
08b809f9 | 3230 | ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> |
5783a860 | 3231 | ** <dd>The maximum number of instructions in a virtual machine program |
08b809f9 EM |
3232 | ** used to implement an SQL statement. This limit is not currently |
3233 | ** enforced, though that might be added in some future release of | |
3234 | ** SQLite.</dd>)^ | |
5783a860 | 3235 | ** |
08b809f9 EM |
3236 | ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> |
3237 | ** <dd>The maximum number of arguments on a function.</dd>)^ | |
5783a860 | 3238 | ** |
08b809f9 EM |
3239 | ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> |
3240 | ** <dd>The maximum number of [ATTACH | attached databases].)^</dd> | |
5783a860 | 3241 | ** |
08b809f9 EM |
3242 | ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] |
3243 | ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> | |
3244 | ** <dd>The maximum length of the pattern argument to the [LIKE] or | |
3245 | ** [GLOB] operators.</dd>)^ | |
5783a860 | 3246 | ** |
08b809f9 EM |
3247 | ** [[SQLITE_LIMIT_VARIABLE_NUMBER]] |
3248 | ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> | |
3249 | ** <dd>The maximum index number of any [parameter] in an SQL statement.)^ | |
3250 | ** | |
3251 | ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> | |
3252 | ** <dd>The maximum depth of recursion for triggers.</dd>)^ | |
3253 | ** | |
3254 | ** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> | |
3255 | ** <dd>The maximum number of auxiliary worker threads that a single | |
3256 | ** [prepared statement] may start.</dd>)^ | |
5783a860 AC |
3257 | ** </dl> |
3258 | */ | |
3259 | #define SQLITE_LIMIT_LENGTH 0 | |
3260 | #define SQLITE_LIMIT_SQL_LENGTH 1 | |
3261 | #define SQLITE_LIMIT_COLUMN 2 | |
3262 | #define SQLITE_LIMIT_EXPR_DEPTH 3 | |
3263 | #define SQLITE_LIMIT_COMPOUND_SELECT 4 | |
3264 | #define SQLITE_LIMIT_VDBE_OP 5 | |
3265 | #define SQLITE_LIMIT_FUNCTION_ARG 6 | |
3266 | #define SQLITE_LIMIT_ATTACHED 7 | |
3267 | #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 | |
3268 | #define SQLITE_LIMIT_VARIABLE_NUMBER 9 | |
08b809f9 EM |
3269 | #define SQLITE_LIMIT_TRIGGER_DEPTH 10 |
3270 | #define SQLITE_LIMIT_WORKER_THREADS 11 | |
5783a860 AC |
3271 | |
3272 | /* | |
08b809f9 EM |
3273 | ** CAPI3REF: Compiling An SQL Statement |
3274 | ** KEYWORDS: {SQL statement compiler} | |
3275 | ** METHOD: sqlite3 | |
3276 | ** CONSTRUCTOR: sqlite3_stmt | |
5783a860 AC |
3277 | ** |
3278 | ** To execute an SQL query, it must first be compiled into a byte-code | |
4094d2fa | 3279 | ** program using one of these routines. |
5783a860 | 3280 | ** |
08b809f9 EM |
3281 | ** The first argument, "db", is a [database connection] obtained from a |
3282 | ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or | |
3283 | ** [sqlite3_open16()]. The database connection must not have been closed. | |
3284 | ** | |
3285 | ** The second argument, "zSql", is the statement to be compiled, encoded | |
5783a860 | 3286 | ** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() |
08b809f9 EM |
3287 | ** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2() |
3288 | ** use UTF-16. | |
3289 | ** | |
3290 | ** ^If the nByte argument is negative, then zSql is read up to the | |
3291 | ** first zero terminator. ^If nByte is positive, then it is the | |
3292 | ** number of bytes read from zSql. ^If nByte is zero, then no prepared | |
3293 | ** statement is generated. | |
3294 | ** If the caller knows that the supplied string is nul-terminated, then | |
3295 | ** there is a small performance advantage to passing an nByte parameter that | |
3296 | ** is the number of bytes in the input string <i>including</i> | |
3297 | ** the nul-terminator. | |
3298 | ** | |
3299 | ** ^If pzTail is not NULL then *pzTail is made to point to the first byte | |
3300 | ** past the end of the first SQL statement in zSql. These routines only | |
3301 | ** compile the first statement in zSql, so *pzTail is left pointing to | |
3302 | ** what remains uncompiled. | |
3303 | ** | |
3304 | ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be | |
3305 | ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set | |
3306 | ** to NULL. ^If the input text contains no SQL (if the input is an empty | |
3307 | ** string or a comment) then *ppStmt is set to NULL. | |
3308 | ** The calling procedure is responsible for deleting the compiled | |
3309 | ** SQL statement using [sqlite3_finalize()] after it has finished with it. | |
3310 | ** ppStmt may not be NULL. | |
3311 | ** | |
3312 | ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; | |
3313 | ** otherwise an [error code] is returned. | |
5783a860 AC |
3314 | ** |
3315 | ** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are | |
3316 | ** recommended for all new programs. The two older interfaces are retained | |
3317 | ** for backwards compatibility, but their use is discouraged. | |
08b809f9 | 3318 | ** ^In the "v2" interfaces, the prepared statement |
4094d2fa | 3319 | ** that is returned (the [sqlite3_stmt] object) contains a copy of the |
08b809f9 EM |
3320 | ** original SQL text. This causes the [sqlite3_step()] interface to |
3321 | ** behave differently in three ways: | |
5783a860 AC |
3322 | ** |
3323 | ** <ol> | |
3324 | ** <li> | |
08b809f9 | 3325 | ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it |
5783a860 | 3326 | ** always used to do, [sqlite3_step()] will automatically recompile the SQL |
08b809f9 EM |
3327 | ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] |
3328 | ** retries will occur before sqlite3_step() gives up and returns an error. | |
5783a860 AC |
3329 | ** </li> |
3330 | ** | |
3331 | ** <li> | |
08b809f9 EM |
3332 | ** ^When an error occurs, [sqlite3_step()] will return one of the detailed |
3333 | ** [error codes] or [extended error codes]. ^The legacy behavior was that | |
3334 | ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code | |
3335 | ** and the application would have to make a second call to [sqlite3_reset()] | |
3336 | ** in order to find the underlying cause of the problem. With the "v2" prepare | |
3337 | ** interfaces, the underlying reason for the error is returned immediately. | |
5783a860 | 3338 | ** </li> |
5783a860 | 3339 | ** |
08b809f9 EM |
3340 | ** <li> |
3341 | ** ^If the specific value bound to [parameter | host parameter] in the | |
3342 | ** WHERE clause might influence the choice of query plan for a statement, | |
3343 | ** then the statement will be automatically recompiled, as if there had been | |
3344 | ** a schema change, on the first [sqlite3_step()] call following any change | |
3345 | ** to the [sqlite3_bind_text | bindings] of that [parameter]. | |
3346 | ** ^The specific value of WHERE-clause [parameter] might influence the | |
3347 | ** choice of query plan if the parameter is the left-hand side of a [LIKE] | |
3348 | ** or [GLOB] operator or if the parameter is compared to an indexed column | |
3349 | ** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled. | |
3350 | ** </li> | |
3351 | ** </ol> | |
5783a860 | 3352 | */ |
08b809f9 | 3353 | SQLITE_API int SQLITE_STDCALL sqlite3_prepare( |
5783a860 AC |
3354 | sqlite3 *db, /* Database handle */ |
3355 | const char *zSql, /* SQL statement, UTF-8 encoded */ | |
3356 | int nByte, /* Maximum length of zSql in bytes. */ | |
3357 | sqlite3_stmt **ppStmt, /* OUT: Statement handle */ | |
3358 | const char **pzTail /* OUT: Pointer to unused portion of zSql */ | |
3359 | ); | |
08b809f9 | 3360 | SQLITE_API int SQLITE_STDCALL sqlite3_prepare_v2( |
5783a860 AC |
3361 | sqlite3 *db, /* Database handle */ |
3362 | const char *zSql, /* SQL statement, UTF-8 encoded */ | |
3363 | int nByte, /* Maximum length of zSql in bytes. */ | |
3364 | sqlite3_stmt **ppStmt, /* OUT: Statement handle */ | |
3365 | const char **pzTail /* OUT: Pointer to unused portion of zSql */ | |
3366 | ); | |
08b809f9 | 3367 | SQLITE_API int SQLITE_STDCALL sqlite3_prepare16( |
5783a860 AC |
3368 | sqlite3 *db, /* Database handle */ |
3369 | const void *zSql, /* SQL statement, UTF-16 encoded */ | |
3370 | int nByte, /* Maximum length of zSql in bytes. */ | |
3371 | sqlite3_stmt **ppStmt, /* OUT: Statement handle */ | |
3372 | const void **pzTail /* OUT: Pointer to unused portion of zSql */ | |
3373 | ); | |
08b809f9 | 3374 | SQLITE_API int SQLITE_STDCALL sqlite3_prepare16_v2( |
5783a860 AC |
3375 | sqlite3 *db, /* Database handle */ |
3376 | const void *zSql, /* SQL statement, UTF-16 encoded */ | |
3377 | int nByte, /* Maximum length of zSql in bytes. */ | |
3378 | sqlite3_stmt **ppStmt, /* OUT: Statement handle */ | |
3379 | const void **pzTail /* OUT: Pointer to unused portion of zSql */ | |
3380 | ); | |
3381 | ||
3382 | /* | |
08b809f9 EM |
3383 | ** CAPI3REF: Retrieving Statement SQL |
3384 | ** METHOD: sqlite3_stmt | |
5783a860 | 3385 | ** |
08b809f9 EM |
3386 | ** ^This interface can be used to retrieve a saved copy of the original |
3387 | ** SQL text used to create a [prepared statement] if that statement was | |
3388 | ** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()]. | |
3389 | */ | |
3390 | SQLITE_API const char *SQLITE_STDCALL sqlite3_sql(sqlite3_stmt *pStmt); | |
3391 | ||
3392 | /* | |
3393 | ** CAPI3REF: Determine If An SQL Statement Writes The Database | |
3394 | ** METHOD: sqlite3_stmt | |
5783a860 | 3395 | ** |
08b809f9 EM |
3396 | ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if |
3397 | ** and only if the [prepared statement] X makes no direct changes to | |
3398 | ** the content of the database file. | |
5783a860 | 3399 | ** |
08b809f9 EM |
3400 | ** Note that [application-defined SQL functions] or |
3401 | ** [virtual tables] might change the database indirectly as a side effect. | |
3402 | ** ^(For example, if an application defines a function "eval()" that | |
3403 | ** calls [sqlite3_exec()], then the following SQL statement would | |
3404 | ** change the database file through side-effects: | |
5783a860 | 3405 | ** |
08b809f9 EM |
3406 | ** <blockquote><pre> |
3407 | ** SELECT eval('DELETE FROM t1') FROM t2; | |
3408 | ** </pre></blockquote> | |
5783a860 | 3409 | ** |
08b809f9 EM |
3410 | ** But because the [SELECT] statement does not change the database file |
3411 | ** directly, sqlite3_stmt_readonly() would still return true.)^ | |
3412 | ** | |
3413 | ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], | |
3414 | ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, | |
3415 | ** since the statements themselves do not actually modify the database but | |
3416 | ** rather they control the timing of when other statements modify the | |
3417 | ** database. ^The [ATTACH] and [DETACH] statements also cause | |
3418 | ** sqlite3_stmt_readonly() to return true since, while those statements | |
3419 | ** change the configuration of a database connection, they do not make | |
3420 | ** changes to the content of the database files on disk. | |
5783a860 | 3421 | */ |
08b809f9 | 3422 | SQLITE_API int SQLITE_STDCALL sqlite3_stmt_readonly(sqlite3_stmt *pStmt); |
5783a860 AC |
3423 | |
3424 | /* | |
08b809f9 EM |
3425 | ** CAPI3REF: Determine If A Prepared Statement Has Been Reset |
3426 | ** METHOD: sqlite3_stmt | |
3427 | ** | |
3428 | ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the | |
3429 | ** [prepared statement] S has been stepped at least once using | |
3430 | ** [sqlite3_step(S)] but has neither run to completion (returned | |
3431 | ** [SQLITE_DONE] from [sqlite3_step(S)]) nor | |
3432 | ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) | |
3433 | ** interface returns false if S is a NULL pointer. If S is not a | |
3434 | ** NULL pointer and is not a pointer to a valid [prepared statement] | |
3435 | ** object, then the behavior is undefined and probably undesirable. | |
3436 | ** | |
3437 | ** This interface can be used in combination [sqlite3_next_stmt()] | |
3438 | ** to locate all prepared statements associated with a database | |
3439 | ** connection that are in need of being reset. This can be used, | |
3440 | ** for example, in diagnostic routines to search for prepared | |
3441 | ** statements that are holding a transaction open. | |
3442 | */ | |
3443 | SQLITE_API int SQLITE_STDCALL sqlite3_stmt_busy(sqlite3_stmt*); | |
3444 | ||
3445 | /* | |
3446 | ** CAPI3REF: Dynamically Typed Value Object | |
5783a860 AC |
3447 | ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} |
3448 | ** | |
3449 | ** SQLite uses the sqlite3_value object to represent all values | |
08b809f9 EM |
3450 | ** that can be stored in a database table. SQLite uses dynamic typing |
3451 | ** for the values it stores. ^Values stored in sqlite3_value objects | |
3452 | ** can be integers, floating point values, strings, BLOBs, or NULL. | |
5783a860 AC |
3453 | ** |
3454 | ** An sqlite3_value object may be either "protected" or "unprotected". | |
3455 | ** Some interfaces require a protected sqlite3_value. Other interfaces | |
3456 | ** will accept either a protected or an unprotected sqlite3_value. | |
4094d2fa | 3457 | ** Every interface that accepts sqlite3_value arguments specifies |
08b809f9 EM |
3458 | ** whether or not it requires a protected sqlite3_value. The |
3459 | ** [sqlite3_value_dup()] interface can be used to construct a new | |
3460 | ** protected sqlite3_value from an unprotected sqlite3_value. | |
5783a860 AC |
3461 | ** |
3462 | ** The terms "protected" and "unprotected" refer to whether or not | |
08b809f9 | 3463 | ** a mutex is held. An internal mutex is held for a protected |
5783a860 AC |
3464 | ** sqlite3_value object but no mutex is held for an unprotected |
3465 | ** sqlite3_value object. If SQLite is compiled to be single-threaded | |
08b809f9 EM |
3466 | ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) |
3467 | ** or if SQLite is run in one of reduced mutex modes | |
3468 | ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] | |
3469 | ** then there is no distinction between protected and unprotected | |
3470 | ** sqlite3_value objects and they can be used interchangeably. However, | |
3471 | ** for maximum code portability it is recommended that applications | |
3472 | ** still make the distinction between protected and unprotected | |
3473 | ** sqlite3_value objects even when not strictly required. | |
3474 | ** | |
3475 | ** ^The sqlite3_value objects that are passed as parameters into the | |
3476 | ** implementation of [application-defined SQL functions] are protected. | |
3477 | ** ^The sqlite3_value object returned by | |
5783a860 AC |
3478 | ** [sqlite3_column_value()] is unprotected. |
3479 | ** Unprotected sqlite3_value objects may only be used with | |
08b809f9 EM |
3480 | ** [sqlite3_result_value()] and [sqlite3_bind_value()]. |
3481 | ** The [sqlite3_value_blob | sqlite3_value_type()] family of | |
3482 | ** interfaces require protected sqlite3_value objects. | |
5783a860 AC |
3483 | */ |
3484 | typedef struct Mem sqlite3_value; | |
3485 | ||
3486 | /* | |
08b809f9 | 3487 | ** CAPI3REF: SQL Function Context Object |
5783a860 AC |
3488 | ** |
3489 | ** The context in which an SQL function executes is stored in an | |
08b809f9 EM |
3490 | ** sqlite3_context object. ^A pointer to an sqlite3_context object |
3491 | ** is always first parameter to [application-defined SQL functions]. | |
3492 | ** The application-defined SQL function implementation will pass this | |
3493 | ** pointer through into calls to [sqlite3_result_int | sqlite3_result()], | |
3494 | ** [sqlite3_aggregate_context()], [sqlite3_user_data()], | |
3495 | ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], | |
3496 | ** and/or [sqlite3_set_auxdata()]. | |
5783a860 AC |
3497 | */ |
3498 | typedef struct sqlite3_context sqlite3_context; | |
3499 | ||
3500 | /* | |
08b809f9 EM |
3501 | ** CAPI3REF: Binding Values To Prepared Statements |
3502 | ** KEYWORDS: {host parameter} {host parameters} {host parameter name} | |
3503 | ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} | |
3504 | ** METHOD: sqlite3_stmt | |
5783a860 | 3505 | ** |
08b809f9 EM |
3506 | ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, |
3507 | ** literals may be replaced by a [parameter] that matches one of following | |
3508 | ** templates: | |
5783a860 AC |
3509 | ** |
3510 | ** <ul> | |
3511 | ** <li> ? | |
3512 | ** <li> ?NNN | |
3513 | ** <li> :VVV | |
3514 | ** <li> @VVV | |
3515 | ** <li> $VVV | |
3516 | ** </ul> | |
3517 | ** | |
08b809f9 EM |
3518 | ** In the templates above, NNN represents an integer literal, |
3519 | ** and VVV represents an alphanumeric identifier.)^ ^The values of these | |
3520 | ** parameters (also called "host parameter names" or "SQL parameters") | |
5783a860 AC |
3521 | ** can be set using the sqlite3_bind_*() routines defined here. |
3522 | ** | |
08b809f9 EM |
3523 | ** ^The first argument to the sqlite3_bind_*() routines is always |
3524 | ** a pointer to the [sqlite3_stmt] object returned from | |
3525 | ** [sqlite3_prepare_v2()] or its variants. | |
3526 | ** | |
3527 | ** ^The second argument is the index of the SQL parameter to be set. | |
3528 | ** ^The leftmost SQL parameter has an index of 1. ^When the same named | |
3529 | ** SQL parameter is used more than once, second and subsequent | |
4094d2fa | 3530 | ** occurrences have the same index as the first occurrence. |
08b809f9 EM |
3531 | ** ^The index for named parameters can be looked up using the |
3532 | ** [sqlite3_bind_parameter_index()] API if desired. ^The index | |
5783a860 | 3533 | ** for "?NNN" parameters is the value of NNN. |
08b809f9 EM |
3534 | ** ^The NNN value must be between 1 and the [sqlite3_limit()] |
3535 | ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). | |
3536 | ** | |
3537 | ** ^The third argument is the value to bind to the parameter. | |
3538 | ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() | |
3539 | ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter | |
3540 | ** is ignored and the end result is the same as sqlite3_bind_null(). | |
3541 | ** | |
3542 | ** ^(In those routines that have a fourth argument, its value is the | |
3543 | ** number of bytes in the parameter. To be clear: the value is the | |
3544 | ** number of <u>bytes</u> in the value, not the number of characters.)^ | |
3545 | ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() | |
3546 | ** is negative, then the length of the string is | |
3547 | ** the number of bytes up to the first zero terminator. | |
3548 | ** If the fourth parameter to sqlite3_bind_blob() is negative, then | |
3549 | ** the behavior is undefined. | |
3550 | ** If a non-negative fourth parameter is provided to sqlite3_bind_text() | |
3551 | ** or sqlite3_bind_text16() or sqlite3_bind_text64() then | |
3552 | ** that parameter must be the byte offset | |
3553 | ** where the NUL terminator would occur assuming the string were NUL | |
3554 | ** terminated. If any NUL characters occur at byte offsets less than | |
3555 | ** the value of the fourth parameter then the resulting string value will | |
3556 | ** contain embedded NULs. The result of expressions involving strings | |
3557 | ** with embedded NULs is undefined. | |
3558 | ** | |
3559 | ** ^The fifth argument to the BLOB and string binding interfaces | |
3560 | ** is a destructor used to dispose of the BLOB or | |
3561 | ** string after SQLite has finished with it. ^The destructor is called | |
3562 | ** to dispose of the BLOB or string even if the call to bind API fails. | |
3563 | ** ^If the fifth argument is | |
5783a860 AC |
3564 | ** the special value [SQLITE_STATIC], then SQLite assumes that the |
3565 | ** information is in static, unmanaged space and does not need to be freed. | |
08b809f9 | 3566 | ** ^If the fifth argument has the value [SQLITE_TRANSIENT], then |
5783a860 AC |
3567 | ** SQLite makes its own private copy of the data immediately, before |
3568 | ** the sqlite3_bind_*() routine returns. | |
3569 | ** | |
08b809f9 EM |
3570 | ** ^The sixth argument to sqlite3_bind_text64() must be one of |
3571 | ** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] | |
3572 | ** to specify the encoding of the text in the third parameter. If | |
3573 | ** the sixth argument to sqlite3_bind_text64() is not one of the | |
3574 | ** allowed values shown above, or if the text encoding is different | |
3575 | ** from the encoding specified by the sixth parameter, then the behavior | |
3576 | ** is undefined. | |
3577 | ** | |
3578 | ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that | |
3579 | ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory | |
3580 | ** (just an integer to hold its size) while it is being processed. | |
3581 | ** Zeroblobs are intended to serve as placeholders for BLOBs whose | |
4094d2fa | 3582 | ** content is later written using |
08b809f9 EM |
3583 | ** [sqlite3_blob_open | incremental BLOB I/O] routines. |
3584 | ** ^A negative value for the zeroblob results in a zero-length BLOB. | |
3585 | ** | |
3586 | ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer | |
3587 | ** for the [prepared statement] or with a prepared statement for which | |
3588 | ** [sqlite3_step()] has been called more recently than [sqlite3_reset()], | |
3589 | ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() | |
3590 | ** routine is passed a [prepared statement] that has been finalized, the | |
3591 | ** result is undefined and probably harmful. | |
3592 | ** | |
3593 | ** ^Bindings are not cleared by the [sqlite3_reset()] routine. | |
3594 | ** ^Unbound parameters are interpreted as NULL. | |
3595 | ** | |
3596 | ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an | |
3597 | ** [error code] if anything goes wrong. | |
3598 | ** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB | |
3599 | ** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or | |
3600 | ** [SQLITE_MAX_LENGTH]. | |
3601 | ** ^[SQLITE_RANGE] is returned if the parameter | |
3602 | ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. | |
5783a860 AC |
3603 | ** |
3604 | ** See also: [sqlite3_bind_parameter_count()], | |
08b809f9 EM |
3605 | ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. |
3606 | */ | |
3607 | SQLITE_API int SQLITE_STDCALL sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); | |
3608 | SQLITE_API int SQLITE_STDCALL sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, | |
3609 | void(*)(void*)); | |
3610 | SQLITE_API int SQLITE_STDCALL sqlite3_bind_double(sqlite3_stmt*, int, double); | |
3611 | SQLITE_API int SQLITE_STDCALL sqlite3_bind_int(sqlite3_stmt*, int, int); | |
3612 | SQLITE_API int SQLITE_STDCALL sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); | |
3613 | SQLITE_API int SQLITE_STDCALL sqlite3_bind_null(sqlite3_stmt*, int); | |
3614 | SQLITE_API int SQLITE_STDCALL sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); | |
3615 | SQLITE_API int SQLITE_STDCALL sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); | |
3616 | SQLITE_API int SQLITE_STDCALL sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, | |
3617 | void(*)(void*), unsigned char encoding); | |
3618 | SQLITE_API int SQLITE_STDCALL sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); | |
3619 | SQLITE_API int SQLITE_STDCALL sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); | |
3620 | SQLITE_API int SQLITE_STDCALL sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); | |
3621 | ||
3622 | /* | |
3623 | ** CAPI3REF: Number Of SQL Parameters | |
3624 | ** METHOD: sqlite3_stmt | |
5783a860 | 3625 | ** |
08b809f9 EM |
3626 | ** ^This routine can be used to find the number of [SQL parameters] |
3627 | ** in a [prepared statement]. SQL parameters are tokens of the | |
5783a860 | 3628 | ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as |
08b809f9 | 3629 | ** placeholders for values that are [sqlite3_bind_blob | bound] |
5783a860 AC |
3630 | ** to the parameters at a later time. |
3631 | ** | |
08b809f9 EM |
3632 | ** ^(This routine actually returns the index of the largest (rightmost) |
3633 | ** parameter. For all forms except ?NNN, this will correspond to the | |
3634 | ** number of unique parameters. If parameters of the ?NNN form are used, | |
3635 | ** there may be gaps in the list.)^ | |
5783a860 AC |
3636 | ** |
3637 | ** See also: [sqlite3_bind_blob|sqlite3_bind()], | |
3638 | ** [sqlite3_bind_parameter_name()], and | |
3639 | ** [sqlite3_bind_parameter_index()]. | |
5783a860 | 3640 | */ |
08b809f9 | 3641 | SQLITE_API int SQLITE_STDCALL sqlite3_bind_parameter_count(sqlite3_stmt*); |
5783a860 AC |
3642 | |
3643 | /* | |
08b809f9 EM |
3644 | ** CAPI3REF: Name Of A Host Parameter |
3645 | ** METHOD: sqlite3_stmt | |
5783a860 | 3646 | ** |
08b809f9 EM |
3647 | ** ^The sqlite3_bind_parameter_name(P,N) interface returns |
3648 | ** the name of the N-th [SQL parameter] in the [prepared statement] P. | |
3649 | ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" | |
5783a860 AC |
3650 | ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" |
3651 | ** respectively. | |
3652 | ** In other words, the initial ":" or "$" or "@" or "?" | |
08b809f9 EM |
3653 | ** is included as part of the name.)^ |
3654 | ** ^Parameters of the form "?" without a following integer have no name | |
3655 | ** and are referred to as "nameless" or "anonymous parameters". | |
5783a860 | 3656 | ** |
08b809f9 | 3657 | ** ^The first host parameter has an index of 1, not 0. |
5783a860 | 3658 | ** |
08b809f9 EM |
3659 | ** ^If the value N is out of range or if the N-th parameter is |
3660 | ** nameless, then NULL is returned. ^The returned string is | |
3661 | ** always in UTF-8 encoding even if the named parameter was | |
5783a860 AC |
3662 | ** originally specified as UTF-16 in [sqlite3_prepare16()] or |
3663 | ** [sqlite3_prepare16_v2()]. | |
3664 | ** | |
3665 | ** See also: [sqlite3_bind_blob|sqlite3_bind()], | |
3666 | ** [sqlite3_bind_parameter_count()], and | |
3667 | ** [sqlite3_bind_parameter_index()]. | |
5783a860 | 3668 | */ |
08b809f9 | 3669 | SQLITE_API const char *SQLITE_STDCALL sqlite3_bind_parameter_name(sqlite3_stmt*, int); |
5783a860 AC |
3670 | |
3671 | /* | |
08b809f9 EM |
3672 | ** CAPI3REF: Index Of A Parameter With A Given Name |
3673 | ** METHOD: sqlite3_stmt | |
5783a860 | 3674 | ** |
08b809f9 | 3675 | ** ^Return the index of an SQL parameter given its name. ^The |
5783a860 | 3676 | ** index value returned is suitable for use as the second |
08b809f9 EM |
3677 | ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero |
3678 | ** is returned if no matching parameter is found. ^The parameter | |
5783a860 AC |
3679 | ** name must be given in UTF-8 even if the original statement |
3680 | ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. | |
3681 | ** | |
3682 | ** See also: [sqlite3_bind_blob|sqlite3_bind()], | |
3683 | ** [sqlite3_bind_parameter_count()], and | |
08b809f9 | 3684 | ** [sqlite3_bind_parameter_name()]. |
5783a860 | 3685 | */ |
08b809f9 | 3686 | SQLITE_API int SQLITE_STDCALL sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); |
5783a860 AC |
3687 | |
3688 | /* | |
08b809f9 EM |
3689 | ** CAPI3REF: Reset All Bindings On A Prepared Statement |
3690 | ** METHOD: sqlite3_stmt | |
5783a860 | 3691 | ** |
08b809f9 EM |
3692 | ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset |
3693 | ** the [sqlite3_bind_blob | bindings] on a [prepared statement]. | |
3694 | ** ^Use this routine to reset all host parameters to NULL. | |
5783a860 | 3695 | */ |
08b809f9 | 3696 | SQLITE_API int SQLITE_STDCALL sqlite3_clear_bindings(sqlite3_stmt*); |
5783a860 AC |
3697 | |
3698 | /* | |
08b809f9 EM |
3699 | ** CAPI3REF: Number Of Columns In A Result Set |
3700 | ** METHOD: sqlite3_stmt | |
5783a860 | 3701 | ** |
08b809f9 EM |
3702 | ** ^Return the number of columns in the result set returned by the |
3703 | ** [prepared statement]. ^This routine returns 0 if pStmt is an SQL | |
3704 | ** statement that does not return data (for example an [UPDATE]). | |
5783a860 | 3705 | ** |
08b809f9 | 3706 | ** See also: [sqlite3_data_count()] |
5783a860 | 3707 | */ |
08b809f9 | 3708 | SQLITE_API int SQLITE_STDCALL sqlite3_column_count(sqlite3_stmt *pStmt); |
5783a860 AC |
3709 | |
3710 | /* | |
08b809f9 EM |
3711 | ** CAPI3REF: Column Names In A Result Set |
3712 | ** METHOD: sqlite3_stmt | |
5783a860 | 3713 | ** |
08b809f9 EM |
3714 | ** ^These routines return the name assigned to a particular column |
3715 | ** in the result set of a [SELECT] statement. ^The sqlite3_column_name() | |
3716 | ** interface returns a pointer to a zero-terminated UTF-8 string | |
5783a860 | 3717 | ** and sqlite3_column_name16() returns a pointer to a zero-terminated |
08b809f9 EM |
3718 | ** UTF-16 string. ^The first parameter is the [prepared statement] |
3719 | ** that implements the [SELECT] statement. ^The second parameter is the | |
3720 | ** column number. ^The leftmost column is number 0. | |
5783a860 | 3721 | ** |
08b809f9 EM |
3722 | ** ^The returned string pointer is valid until either the [prepared statement] |
3723 | ** is destroyed by [sqlite3_finalize()] or until the statement is automatically | |
3724 | ** reprepared by the first call to [sqlite3_step()] for a particular run | |
3725 | ** or until the next call to | |
3726 | ** sqlite3_column_name() or sqlite3_column_name16() on the same column. | |
5783a860 | 3727 | ** |
08b809f9 | 3728 | ** ^If sqlite3_malloc() fails during the processing of either routine |
5783a860 AC |
3729 | ** (for example during a conversion from UTF-8 to UTF-16) then a |
3730 | ** NULL pointer is returned. | |
3731 | ** | |
08b809f9 | 3732 | ** ^The name of a result column is the value of the "AS" clause for |
5783a860 AC |
3733 | ** that column, if there is an AS clause. If there is no AS clause |
3734 | ** then the name of the column is unspecified and may change from | |
3735 | ** one release of SQLite to the next. | |
5783a860 | 3736 | */ |
08b809f9 EM |
3737 | SQLITE_API const char *SQLITE_STDCALL sqlite3_column_name(sqlite3_stmt*, int N); |
3738 | SQLITE_API const void *SQLITE_STDCALL sqlite3_column_name16(sqlite3_stmt*, int N); | |
5783a860 AC |
3739 | |
3740 | /* | |
08b809f9 EM |
3741 | ** CAPI3REF: Source Of Data In A Query Result |
3742 | ** METHOD: sqlite3_stmt | |
3743 | ** | |
3744 | ** ^These routines provide a means to determine the database, table, and | |
3745 | ** table column that is the origin of a particular result column in | |
3746 | ** [SELECT] statement. | |
3747 | ** ^The name of the database or table or column can be returned as | |
3748 | ** either a UTF-8 or UTF-16 string. ^The _database_ routines return | |
5783a860 AC |
3749 | ** the database name, the _table_ routines return the table name, and |
3750 | ** the origin_ routines return the column name. | |
08b809f9 EM |
3751 | ** ^The returned string is valid until the [prepared statement] is destroyed |
3752 | ** using [sqlite3_finalize()] or until the statement is automatically | |
3753 | ** reprepared by the first call to [sqlite3_step()] for a particular run | |
3754 | ** or until the same information is requested | |
5783a860 AC |
3755 | ** again in a different encoding. |
3756 | ** | |
08b809f9 | 3757 | ** ^The names returned are the original un-aliased names of the |
5783a860 AC |
3758 | ** database, table, and column. |
3759 | ** | |
08b809f9 EM |
3760 | ** ^The first argument to these interfaces is a [prepared statement]. |
3761 | ** ^These functions return information about the Nth result column returned by | |
5783a860 | 3762 | ** the statement, where N is the second function argument. |
08b809f9 | 3763 | ** ^The left-most column is column 0 for these routines. |
5783a860 | 3764 | ** |
08b809f9 EM |
3765 | ** ^If the Nth column returned by the statement is an expression or |
3766 | ** subquery and is not a column value, then all of these functions return | |
3767 | ** NULL. ^These routine might also return NULL if a memory allocation error | |
3768 | ** occurs. ^Otherwise, they return the name of the attached database, table, | |
3769 | ** or column that query result column was extracted from. | |
5783a860 | 3770 | ** |
08b809f9 EM |
3771 | ** ^As with all other SQLite APIs, those whose names end with "16" return |
3772 | ** UTF-16 encoded strings and the other functions return UTF-8. | |
5783a860 | 3773 | ** |
08b809f9 EM |
3774 | ** ^These APIs are only available if the library was compiled with the |
3775 | ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. | |
5783a860 | 3776 | ** |
5783a860 AC |
3777 | ** If two or more threads call one or more of these routines against the same |
3778 | ** prepared statement and column at the same time then the results are | |
3779 | ** undefined. | |
3780 | ** | |
08b809f9 EM |
3781 | ** If two or more threads call one or more |
3782 | ** [sqlite3_column_database_name | column metadata interfaces] | |
3783 | ** for the same [prepared statement] and result column | |
3784 | ** at the same time then the results are undefined. | |
3785 | */ | |
3786 | SQLITE_API const char *SQLITE_STDCALL sqlite3_column_database_name(sqlite3_stmt*,int); | |
3787 | SQLITE_API const void *SQLITE_STDCALL sqlite3_column_database_name16(sqlite3_stmt*,int); | |
3788 | SQLITE_API const char *SQLITE_STDCALL sqlite3_column_table_name(sqlite3_stmt*,int); | |
3789 | SQLITE_API const void *SQLITE_STDCALL sqlite3_column_table_name16(sqlite3_stmt*,int); | |
3790 | SQLITE_API const char *SQLITE_STDCALL sqlite3_column_origin_name(sqlite3_stmt*,int); | |
3791 | SQLITE_API const void *SQLITE_STDCALL sqlite3_column_origin_name16(sqlite3_stmt*,int); | |
3792 | ||
3793 | /* | |
3794 | ** CAPI3REF: Declared Datatype Of A Query Result | |
3795 | ** METHOD: sqlite3_stmt | |
3796 | ** | |
3797 | ** ^(The first parameter is a [prepared statement]. | |
3798 | ** If this statement is a [SELECT] statement and the Nth column of the | |
3799 | ** returned result set of that [SELECT] is a table column (not an | |
5783a860 | 3800 | ** expression or subquery) then the declared type of the table |
08b809f9 | 3801 | ** column is returned.)^ ^If the Nth column of the result set is an |
5783a860 | 3802 | ** expression or subquery, then a NULL pointer is returned. |
08b809f9 EM |
3803 | ** ^The returned string is always UTF-8 encoded. |
3804 | ** | |
3805 | ** ^(For example, given the database schema: | |
5783a860 AC |
3806 | ** |
3807 | ** CREATE TABLE t1(c1 VARIANT); | |
3808 | ** | |
08b809f9 | 3809 | ** and the following statement to be compiled: |
5783a860 AC |
3810 | ** |
3811 | ** SELECT c1 + 1, c1 FROM t1; | |
3812 | ** | |
08b809f9 EM |
3813 | ** this routine would return the string "VARIANT" for the second result |
3814 | ** column (i==1), and a NULL pointer for the first result column (i==0).)^ | |
5783a860 | 3815 | ** |
08b809f9 | 3816 | ** ^SQLite uses dynamic run-time typing. ^So just because a column |
5783a860 AC |
3817 | ** is declared to contain a particular type does not mean that the |
3818 | ** data stored in that column is of the declared type. SQLite is | |
08b809f9 | 3819 | ** strongly typed, but the typing is dynamic not static. ^Type |
5783a860 AC |
3820 | ** is associated with individual values, not with the containers |
3821 | ** used to hold those values. | |
5783a860 | 3822 | */ |
08b809f9 EM |
3823 | SQLITE_API const char *SQLITE_STDCALL sqlite3_column_decltype(sqlite3_stmt*,int); |
3824 | SQLITE_API const void *SQLITE_STDCALL sqlite3_column_decltype16(sqlite3_stmt*,int); | |
5783a860 | 3825 | |
4094d2fa | 3826 | /* |
08b809f9 EM |
3827 | ** CAPI3REF: Evaluate An SQL Statement |
3828 | ** METHOD: sqlite3_stmt | |
5783a860 | 3829 | ** |
08b809f9 EM |
3830 | ** After a [prepared statement] has been prepared using either |
3831 | ** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy | |
3832 | ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function | |
3833 | ** must be called one or more times to evaluate the statement. | |
5783a860 | 3834 | ** |
08b809f9 | 3835 | ** The details of the behavior of the sqlite3_step() interface depend |
5783a860 AC |
3836 | ** on whether the statement was prepared using the newer "v2" interface |
3837 | ** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy | |
3838 | ** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the | |
3839 | ** new "v2" interface is recommended for new applications but the legacy | |
3840 | ** interface will continue to be supported. | |
3841 | ** | |
08b809f9 | 3842 | ** ^In the legacy interface, the return value will be either [SQLITE_BUSY], |
5783a860 | 3843 | ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. |
08b809f9 EM |
3844 | ** ^With the "v2" interface, any of the other [result codes] or |
3845 | ** [extended result codes] might be returned as well. | |
5783a860 | 3846 | ** |
08b809f9 EM |
3847 | ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the |
3848 | ** database locks it needs to do its job. ^If the statement is a [COMMIT] | |
5783a860 | 3849 | ** or occurs outside of an explicit transaction, then you can retry the |
08b809f9 | 3850 | ** statement. If the statement is not a [COMMIT] and occurs within an |
5783a860 AC |
3851 | ** explicit transaction then you should rollback the transaction before |
3852 | ** continuing. | |
3853 | ** | |
08b809f9 | 3854 | ** ^[SQLITE_DONE] means that the statement has finished executing |
5783a860 AC |
3855 | ** successfully. sqlite3_step() should not be called again on this virtual |
3856 | ** machine without first calling [sqlite3_reset()] to reset the virtual | |
3857 | ** machine back to its initial state. | |
3858 | ** | |
08b809f9 EM |
3859 | ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] |
3860 | ** is returned each time a new row of data is ready for processing by the | |
3861 | ** caller. The values may be accessed using the [column access functions]. | |
5783a860 | 3862 | ** sqlite3_step() is called again to retrieve the next row of data. |
4094d2fa | 3863 | ** |
08b809f9 | 3864 | ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint |
5783a860 AC |
3865 | ** violation) has occurred. sqlite3_step() should not be called again on |
3866 | ** the VM. More information may be found by calling [sqlite3_errmsg()]. | |
08b809f9 | 3867 | ** ^With the legacy interface, a more specific error code (for example, |
5783a860 AC |
3868 | ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) |
3869 | ** can be obtained by calling [sqlite3_reset()] on the | |
08b809f9 | 3870 | ** [prepared statement]. ^In the "v2" interface, |
5783a860 AC |
3871 | ** the more specific error code is returned directly by sqlite3_step(). |
3872 | ** | |
3873 | ** [SQLITE_MISUSE] means that the this routine was called inappropriately. | |
3874 | ** Perhaps it was called on a [prepared statement] that has | |
4094d2fa | 3875 | ** already been [sqlite3_finalize | finalized] or on one that had |
5783a860 AC |
3876 | ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could |
3877 | ** be the case that the same database connection is being used by two or | |
3878 | ** more threads at the same moment in time. | |
3879 | ** | |
08b809f9 EM |
3880 | ** For all versions of SQLite up to and including 3.6.23.1, a call to |
3881 | ** [sqlite3_reset()] was required after sqlite3_step() returned anything | |
3882 | ** other than [SQLITE_ROW] before any subsequent invocation of | |
3883 | ** sqlite3_step(). Failure to reset the prepared statement using | |
3884 | ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from | |
3885 | ** sqlite3_step(). But after version 3.6.23.1, sqlite3_step() began | |
3886 | ** calling [sqlite3_reset()] automatically in this circumstance rather | |
3887 | ** than returning [SQLITE_MISUSE]. This is not considered a compatibility | |
3888 | ** break because any application that ever receives an SQLITE_MISUSE error | |
3889 | ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option | |
3890 | ** can be used to restore the legacy behavior. | |
3891 | ** | |
3892 | ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() | |
3893 | ** API always returns a generic error code, [SQLITE_ERROR], following any | |
3894 | ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call | |
3895 | ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the | |
3896 | ** specific [error codes] that better describes the error. | |
5783a860 AC |
3897 | ** We admit that this is a goofy design. The problem has been fixed |
3898 | ** with the "v2" interface. If you prepare all of your SQL statements | |
3899 | ** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead | |
08b809f9 EM |
3900 | ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, |
3901 | ** then the more specific [error codes] are returned directly | |
5783a860 | 3902 | ** by sqlite3_step(). The use of the "v2" interface is recommended. |
5783a860 | 3903 | */ |
08b809f9 | 3904 | SQLITE_API int SQLITE_STDCALL sqlite3_step(sqlite3_stmt*); |
5783a860 AC |
3905 | |
3906 | /* | |
08b809f9 EM |
3907 | ** CAPI3REF: Number of columns in a result set |
3908 | ** METHOD: sqlite3_stmt | |
3909 | ** | |
3910 | ** ^The sqlite3_data_count(P) interface returns the number of columns in the | |
3911 | ** current row of the result set of [prepared statement] P. | |
3912 | ** ^If prepared statement P does not have results ready to return | |
3913 | ** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of | |
3914 | ** interfaces) then sqlite3_data_count(P) returns 0. | |
3915 | ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. | |
3916 | ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to | |
3917 | ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) | |
3918 | ** will return non-zero if previous call to [sqlite3_step](P) returned | |
3919 | ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] | |
3920 | ** where it always returns zero since each step of that multi-step | |
3921 | ** pragma returns 0 columns of data. | |
3922 | ** | |
3923 | ** See also: [sqlite3_column_count()] | |
5783a860 | 3924 | */ |
08b809f9 | 3925 | SQLITE_API int SQLITE_STDCALL sqlite3_data_count(sqlite3_stmt *pStmt); |
5783a860 AC |
3926 | |
3927 | /* | |
08b809f9 | 3928 | ** CAPI3REF: Fundamental Datatypes |
5783a860 AC |
3929 | ** KEYWORDS: SQLITE_TEXT |
3930 | ** | |
08b809f9 | 3931 | ** ^(Every value in SQLite has one of five fundamental datatypes: |
5783a860 AC |
3932 | ** |
3933 | ** <ul> | |
3934 | ** <li> 64-bit signed integer | |
3935 | ** <li> 64-bit IEEE floating point number | |
3936 | ** <li> string | |
3937 | ** <li> BLOB | |
3938 | ** <li> NULL | |
08b809f9 | 3939 | ** </ul>)^ |
5783a860 AC |
3940 | ** |
3941 | ** These constants are codes for each of those types. | |
3942 | ** | |
3943 | ** Note that the SQLITE_TEXT constant was also used in SQLite version 2 | |
3944 | ** for a completely different meaning. Software that links against both | |
08b809f9 | 3945 | ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not |
5783a860 AC |
3946 | ** SQLITE_TEXT. |
3947 | */ | |
3948 | #define SQLITE_INTEGER 1 | |
3949 | #define SQLITE_FLOAT 2 | |
3950 | #define SQLITE_BLOB 4 | |
3951 | #define SQLITE_NULL 5 | |
3952 | #ifdef SQLITE_TEXT | |
3953 | # undef SQLITE_TEXT | |
3954 | #else | |
3955 | # define SQLITE_TEXT 3 | |
3956 | #endif | |
3957 | #define SQLITE3_TEXT 3 | |
3958 | ||
3959 | /* | |
08b809f9 EM |
3960 | ** CAPI3REF: Result Values From A Query |
3961 | ** KEYWORDS: {column access functions} | |
3962 | ** METHOD: sqlite3_stmt | |
3963 | ** | |
3964 | ** ^These routines return information about a single column of the current | |
3965 | ** result row of a query. ^In every case the first argument is a pointer | |
3966 | ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] | |
3967 | ** that was returned from [sqlite3_prepare_v2()] or one of its variants) | |
3968 | ** and the second argument is the index of the column for which information | |
3969 | ** should be returned. ^The leftmost column of the result set has the index 0. | |
3970 | ** ^The number of columns in the result can be determined using | |
3971 | ** [sqlite3_column_count()]. | |
3972 | ** | |
3973 | ** If the SQL statement does not currently point to a valid row, or if the | |
3974 | ** column index is out of range, the result is undefined. | |
5783a860 AC |
3975 | ** These routines may only be called when the most recent call to |
3976 | ** [sqlite3_step()] has returned [SQLITE_ROW] and neither | |
08b809f9 | 3977 | ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. |
5783a860 AC |
3978 | ** If any of these routines are called after [sqlite3_reset()] or |
3979 | ** [sqlite3_finalize()] or after [sqlite3_step()] has returned | |
3980 | ** something other than [SQLITE_ROW], the results are undefined. | |
3981 | ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] | |
3982 | ** are called from a different thread while any of these routines | |
4094d2fa | 3983 | ** are pending, then the results are undefined. |
5783a860 | 3984 | ** |
08b809f9 | 3985 | ** ^The sqlite3_column_type() routine returns the |
5783a860 | 3986 | ** [SQLITE_INTEGER | datatype code] for the initial data type |
08b809f9 | 3987 | ** of the result column. ^The returned value is one of [SQLITE_INTEGER], |
5783a860 AC |
3988 | ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value |
3989 | ** returned by sqlite3_column_type() is only meaningful if no type | |
3990 | ** conversions have occurred as described below. After a type conversion, | |
3991 | ** the value returned by sqlite3_column_type() is undefined. Future | |
3992 | ** versions of SQLite may change the behavior of sqlite3_column_type() | |
3993 | ** following a type conversion. | |
3994 | ** | |
08b809f9 | 3995 | ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() |
5783a860 | 3996 | ** routine returns the number of bytes in that BLOB or string. |
08b809f9 | 3997 | ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts |
5783a860 | 3998 | ** the string to UTF-8 and then returns the number of bytes. |
08b809f9 | 3999 | ** ^If the result is a numeric value then sqlite3_column_bytes() uses |
5783a860 AC |
4000 | ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns |
4001 | ** the number of bytes in that string. | |
08b809f9 EM |
4002 | ** ^If the result is NULL, then sqlite3_column_bytes() returns zero. |
4003 | ** | |
4004 | ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() | |
4005 | ** routine returns the number of bytes in that BLOB or string. | |
4006 | ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts | |
4007 | ** the string to UTF-16 and then returns the number of bytes. | |
4008 | ** ^If the result is a numeric value then sqlite3_column_bytes16() uses | |
4009 | ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns | |
4010 | ** the number of bytes in that string. | |
4011 | ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. | |
5783a860 | 4012 | ** |
08b809f9 EM |
4013 | ** ^The values returned by [sqlite3_column_bytes()] and |
4014 | ** [sqlite3_column_bytes16()] do not include the zero terminators at the end | |
4015 | ** of the string. ^For clarity: the values returned by | |
4016 | ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of | |
4017 | ** bytes in the string, not the number of characters. | |
5783a860 | 4018 | ** |
08b809f9 EM |
4019 | ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), |
4020 | ** even empty strings, are always zero-terminated. ^The return | |
4021 | ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. | |
5783a860 | 4022 | ** |
08b809f9 EM |
4023 | ** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an |
4024 | ** [unprotected sqlite3_value] object. In a multithreaded environment, | |
4025 | ** an unprotected sqlite3_value object may only be used safely with | |
4026 | ** [sqlite3_bind_value()] and [sqlite3_result_value()]. | |
5783a860 AC |
4027 | ** If the [unprotected sqlite3_value] object returned by |
4028 | ** [sqlite3_column_value()] is used in any other way, including calls | |
08b809f9 EM |
4029 | ** to routines like [sqlite3_value_int()], [sqlite3_value_text()], |
4030 | ** or [sqlite3_value_bytes()], the behavior is not threadsafe. | |
5783a860 | 4031 | ** |
08b809f9 | 4032 | ** These routines attempt to convert the value where appropriate. ^For |
5783a860 | 4033 | ** example, if the internal representation is FLOAT and a text result |
08b809f9 EM |
4034 | ** is requested, [sqlite3_snprintf()] is used internally to perform the |
4035 | ** conversion automatically. ^(The following table details the conversions | |
4036 | ** that are applied: | |
5783a860 AC |
4037 | ** |
4038 | ** <blockquote> | |
4039 | ** <table border="1"> | |
4040 | ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion | |
4041 | ** | |
4042 | ** <tr><td> NULL <td> INTEGER <td> Result is 0 | |
4043 | ** <tr><td> NULL <td> FLOAT <td> Result is 0.0 | |
08b809f9 EM |
4044 | ** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer |
4045 | ** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer | |
5783a860 AC |
4046 | ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float |
4047 | ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer | |
08b809f9 EM |
4048 | ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT |
4049 | ** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER | |
5783a860 | 4050 | ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float |
08b809f9 EM |
4051 | ** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB |
4052 | ** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER | |
4053 | ** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL | |
5783a860 | 4054 | ** <tr><td> TEXT <td> BLOB <td> No change |
08b809f9 EM |
4055 | ** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER |
4056 | ** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL | |
5783a860 AC |
4057 | ** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed |
4058 | ** </table> | |
08b809f9 | 4059 | ** </blockquote>)^ |
5783a860 AC |
4060 | ** |
4061 | ** Note that when type conversions occur, pointers returned by prior | |
4062 | ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or | |
4094d2fa | 4063 | ** sqlite3_column_text16() may be invalidated. |
5783a860 AC |
4064 | ** Type conversions and pointer invalidations might occur |
4065 | ** in the following cases: | |
4066 | ** | |
4067 | ** <ul> | |
08b809f9 EM |
4068 | ** <li> The initial content is a BLOB and sqlite3_column_text() or |
4069 | ** sqlite3_column_text16() is called. A zero-terminator might | |
4070 | ** need to be added to the string.</li> | |
4071 | ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or | |
4072 | ** sqlite3_column_text16() is called. The content must be converted | |
4073 | ** to UTF-16.</li> | |
4074 | ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or | |
4075 | ** sqlite3_column_text() is called. The content must be converted | |
4076 | ** to UTF-8.</li> | |
5783a860 AC |
4077 | ** </ul> |
4078 | ** | |
08b809f9 | 4079 | ** ^Conversions between UTF-16be and UTF-16le are always done in place and do |
5783a860 | 4080 | ** not invalidate a prior pointer, though of course the content of the buffer |
08b809f9 EM |
4081 | ** that the prior pointer references will have been modified. Other kinds |
4082 | ** of conversion are done in place when it is possible, but sometimes they | |
4083 | ** are not possible and in those cases prior pointers are invalidated. | |
5783a860 | 4084 | ** |
08b809f9 | 4085 | ** The safest policy is to invoke these routines |
5783a860 AC |
4086 | ** in one of the following ways: |
4087 | ** | |
08b809f9 | 4088 | ** <ul> |
5783a860 AC |
4089 | ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> |
4090 | ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> | |
4091 | ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> | |
08b809f9 | 4092 | ** </ul> |
5783a860 | 4093 | ** |
08b809f9 EM |
4094 | ** In other words, you should call sqlite3_column_text(), |
4095 | ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result | |
4096 | ** into the desired format, then invoke sqlite3_column_bytes() or | |
4097 | ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls | |
4098 | ** to sqlite3_column_text() or sqlite3_column_blob() with calls to | |
4099 | ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() | |
4100 | ** with calls to sqlite3_column_bytes(). | |
5783a860 | 4101 | ** |
08b809f9 | 4102 | ** ^The pointers returned are valid until a type conversion occurs as |
5783a860 | 4103 | ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or |
08b809f9 EM |
4104 | ** [sqlite3_finalize()] is called. ^The memory space used to hold strings |
4105 | ** and BLOBs is freed automatically. Do <em>not</em> pass the pointers returned | |
4106 | ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into | |
5783a860 AC |
4107 | ** [sqlite3_free()]. |
4108 | ** | |
08b809f9 | 4109 | ** ^(If a memory allocation error occurs during the evaluation of any |
5783a860 AC |
4110 | ** of these routines, a default value is returned. The default value |
4111 | ** is either the integer 0, the floating point number 0.0, or a NULL | |
4112 | ** pointer. Subsequent calls to [sqlite3_errcode()] will return | |
08b809f9 EM |
4113 | ** [SQLITE_NOMEM].)^ |
4114 | */ | |
4115 | SQLITE_API const void *SQLITE_STDCALL sqlite3_column_blob(sqlite3_stmt*, int iCol); | |
4116 | SQLITE_API int SQLITE_STDCALL sqlite3_column_bytes(sqlite3_stmt*, int iCol); | |
4117 | SQLITE_API int SQLITE_STDCALL sqlite3_column_bytes16(sqlite3_stmt*, int iCol); | |
4118 | SQLITE_API double SQLITE_STDCALL sqlite3_column_double(sqlite3_stmt*, int iCol); | |
4119 | SQLITE_API int SQLITE_STDCALL sqlite3_column_int(sqlite3_stmt*, int iCol); | |
4120 | SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_column_int64(sqlite3_stmt*, int iCol); | |
4121 | SQLITE_API const unsigned char *SQLITE_STDCALL sqlite3_column_text(sqlite3_stmt*, int iCol); | |
4122 | SQLITE_API const void *SQLITE_STDCALL sqlite3_column_text16(sqlite3_stmt*, int iCol); | |
4123 | SQLITE_API int SQLITE_STDCALL sqlite3_column_type(sqlite3_stmt*, int iCol); | |
4124 | SQLITE_API sqlite3_value *SQLITE_STDCALL sqlite3_column_value(sqlite3_stmt*, int iCol); | |
4125 | ||
4126 | /* | |
4127 | ** CAPI3REF: Destroy A Prepared Statement Object | |
4128 | ** DESTRUCTOR: sqlite3_stmt | |
4129 | ** | |
4130 | ** ^The sqlite3_finalize() function is called to delete a [prepared statement]. | |
4131 | ** ^If the most recent evaluation of the statement encountered no errors | |
4132 | ** or if the statement is never been evaluated, then sqlite3_finalize() returns | |
4133 | ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then | |
4134 | ** sqlite3_finalize(S) returns the appropriate [error code] or | |
4135 | ** [extended error code]. | |
4136 | ** | |
4137 | ** ^The sqlite3_finalize(S) routine can be called at any point during | |
4138 | ** the life cycle of [prepared statement] S: | |
4139 | ** before statement S is ever evaluated, after | |
4140 | ** one or more calls to [sqlite3_reset()], or after any call | |
4141 | ** to [sqlite3_step()] regardless of whether or not the statement has | |
4142 | ** completed execution. | |
4143 | ** | |
4144 | ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. | |
4145 | ** | |
4146 | ** The application must finalize every [prepared statement] in order to avoid | |
4147 | ** resource leaks. It is a grievous error for the application to try to use | |
4148 | ** a prepared statement after it has been finalized. Any use of a prepared | |
4149 | ** statement after it has been finalized can result in undefined and | |
4150 | ** undesirable behavior such as segfaults and heap corruption. | |
4151 | */ | |
4152 | SQLITE_API int SQLITE_STDCALL sqlite3_finalize(sqlite3_stmt *pStmt); | |
4153 | ||
4154 | /* | |
4155 | ** CAPI3REF: Reset A Prepared Statement Object | |
4156 | ** METHOD: sqlite3_stmt | |
4157 | ** | |
4158 | ** The sqlite3_reset() function is called to reset a [prepared statement] | |
4159 | ** object back to its initial state, ready to be re-executed. | |
4160 | ** ^Any SQL statement variables that had values bound to them using | |
5783a860 AC |
4161 | ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. |
4162 | ** Use [sqlite3_clear_bindings()] to reset the bindings. | |
4163 | ** | |
08b809f9 EM |
4164 | ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S |
4165 | ** back to the beginning of its program. | |
5783a860 | 4166 | ** |
08b809f9 EM |
4167 | ** ^If the most recent call to [sqlite3_step(S)] for the |
4168 | ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], | |
4169 | ** or if [sqlite3_step(S)] has never before been called on S, | |
4170 | ** then [sqlite3_reset(S)] returns [SQLITE_OK]. | |
5783a860 | 4171 | ** |
08b809f9 EM |
4172 | ** ^If the most recent call to [sqlite3_step(S)] for the |
4173 | ** [prepared statement] S indicated an error, then | |
4174 | ** [sqlite3_reset(S)] returns an appropriate [error code]. | |
5783a860 | 4175 | ** |
08b809f9 EM |
4176 | ** ^The [sqlite3_reset(S)] interface does not change the values |
4177 | ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. | |
5783a860 | 4178 | */ |
08b809f9 | 4179 | SQLITE_API int SQLITE_STDCALL sqlite3_reset(sqlite3_stmt *pStmt); |
5783a860 AC |
4180 | |
4181 | /* | |
08b809f9 | 4182 | ** CAPI3REF: Create Or Redefine SQL Functions |
4094d2fa | 4183 | ** KEYWORDS: {function creation routines} |
08b809f9 EM |
4184 | ** KEYWORDS: {application-defined SQL function} |
4185 | ** KEYWORDS: {application-defined SQL functions} | |
4186 | ** METHOD: sqlite3 | |
4187 | ** | |
4188 | ** ^These functions (collectively known as "function creation routines") | |
4189 | ** are used to add SQL functions or aggregates or to redefine the behavior | |
4190 | ** of existing SQL functions or aggregates. The only differences between | |
4191 | ** these routines are the text encoding expected for | |
4192 | ** the second parameter (the name of the function being created) | |
4193 | ** and the presence or absence of a destructor callback for | |
4194 | ** the application data pointer. | |
4195 | ** | |
4196 | ** ^The first parameter is the [database connection] to which the SQL | |
4197 | ** function is to be added. ^If an application uses more than one database | |
4198 | ** connection then application-defined SQL functions must be added | |
4199 | ** to each database connection separately. | |
4200 | ** | |
4201 | ** ^The second parameter is the name of the SQL function to be created or | |
4202 | ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 | |
4203 | ** representation, exclusive of the zero-terminator. ^Note that the name | |
4204 | ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. | |
4205 | ** ^Any attempt to create a function with a longer name | |
4206 | ** will result in [SQLITE_MISUSE] being returned. | |
4207 | ** | |
4208 | ** ^The third parameter (nArg) | |
4209 | ** is the number of arguments that the SQL function or | |
4210 | ** aggregate takes. ^If this parameter is -1, then the SQL function or | |
4211 | ** aggregate may take any number of arguments between 0 and the limit | |
4212 | ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third | |
4213 | ** parameter is less than -1 or greater than 127 then the behavior is | |
4214 | ** undefined. | |
5783a860 | 4215 | ** |
08b809f9 | 4216 | ** ^The fourth parameter, eTextRep, specifies what |
5783a860 | 4217 | ** [SQLITE_UTF8 | text encoding] this SQL function prefers for |
08b809f9 EM |
4218 | ** its parameters. The application should set this parameter to |
4219 | ** [SQLITE_UTF16LE] if the function implementation invokes | |
4220 | ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the | |
4221 | ** implementation invokes [sqlite3_value_text16be()] on an input, or | |
4222 | ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] | |
4223 | ** otherwise. ^The same SQL function may be registered multiple times using | |
4224 | ** different preferred text encodings, with different implementations for | |
4225 | ** each encoding. | |
4226 | ** ^When multiple implementations of the same function are available, SQLite | |
5783a860 | 4227 | ** will pick the one that involves the least amount of data conversion. |
08b809f9 EM |
4228 | ** |
4229 | ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] | |
4230 | ** to signal that the function will always return the same result given | |
4231 | ** the same inputs within a single SQL statement. Most SQL functions are | |
4232 | ** deterministic. The built-in [random()] SQL function is an example of a | |
4233 | ** function that is not deterministic. The SQLite query planner is able to | |
4234 | ** perform additional optimizations on deterministic functions, so use | |
4235 | ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. | |
4236 | ** | |
4237 | ** ^(The fifth parameter is an arbitrary pointer. The implementation of the | |
4238 | ** function can gain access to this pointer using [sqlite3_user_data()].)^ | |
4239 | ** | |
4240 | ** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are | |
4241 | ** pointers to C-language functions that implement the SQL function or | |
4242 | ** aggregate. ^A scalar SQL function requires an implementation of the xFunc | |
4243 | ** callback only; NULL pointers must be passed as the xStep and xFinal | |
4244 | ** parameters. ^An aggregate SQL function requires an implementation of xStep | |
4245 | ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing | |
4246 | ** SQL function or aggregate, pass NULL pointers for all three function | |
4247 | ** callbacks. | |
4248 | ** | |
4249 | ** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL, | |
4250 | ** then it is destructor for the application data pointer. | |
4251 | ** The destructor is invoked when the function is deleted, either by being | |
4252 | ** overloaded or when the database connection closes.)^ | |
4253 | ** ^The destructor is also invoked if the call to | |
4254 | ** sqlite3_create_function_v2() fails. | |
4255 | ** ^When the destructor callback of the tenth parameter is invoked, it | |
4256 | ** is passed a single argument which is a copy of the application data | |
4257 | ** pointer which was the fifth parameter to sqlite3_create_function_v2(). | |
4258 | ** | |
4259 | ** ^It is permitted to register multiple implementations of the same | |
5783a860 | 4260 | ** functions with the same name but with either differing numbers of |
08b809f9 EM |
4261 | ** arguments or differing preferred text encodings. ^SQLite will use |
4262 | ** the implementation that most closely matches the way in which the | |
4263 | ** SQL function is used. ^A function implementation with a non-negative | |
4264 | ** nArg parameter is a better match than a function implementation with | |
4265 | ** a negative nArg. ^A function where the preferred text encoding | |
4266 | ** matches the database encoding is a better | |
4267 | ** match than a function where the encoding is different. | |
4268 | ** ^A function where the encoding difference is between UTF16le and UTF16be | |
4269 | ** is a closer match than a function where the encoding difference is | |
4270 | ** between UTF8 and UTF16. | |
4271 | ** | |
4272 | ** ^Built-in functions may be overloaded by new application-defined functions. | |
4273 | ** | |
4274 | ** ^An application-defined function is permitted to call other | |
4275 | ** SQLite interfaces. However, such calls must not | |
4276 | ** close the database connection nor finalize or reset the prepared | |
4277 | ** statement in which the function is running. | |
4278 | */ | |
4279 | SQLITE_API int SQLITE_STDCALL sqlite3_create_function( | |
5783a860 AC |
4280 | sqlite3 *db, |
4281 | const char *zFunctionName, | |
4282 | int nArg, | |
4283 | int eTextRep, | |
4284 | void *pApp, | |
4285 | void (*xFunc)(sqlite3_context*,int,sqlite3_value**), | |
4286 | void (*xStep)(sqlite3_context*,int,sqlite3_value**), | |
4287 | void (*xFinal)(sqlite3_context*) | |
4288 | ); | |
08b809f9 | 4289 | SQLITE_API int SQLITE_STDCALL sqlite3_create_function16( |
5783a860 AC |
4290 | sqlite3 *db, |
4291 | const void *zFunctionName, | |
4292 | int nArg, | |
4293 | int eTextRep, | |
4294 | void *pApp, | |
4295 | void (*xFunc)(sqlite3_context*,int,sqlite3_value**), | |
4296 | void (*xStep)(sqlite3_context*,int,sqlite3_value**), | |
4297 | void (*xFinal)(sqlite3_context*) | |
4298 | ); | |
08b809f9 EM |
4299 | SQLITE_API int SQLITE_STDCALL sqlite3_create_function_v2( |
4300 | sqlite3 *db, | |
4301 | const char *zFunctionName, | |
4302 | int nArg, | |
4303 | int eTextRep, | |
4304 | void *pApp, | |
4305 | void (*xFunc)(sqlite3_context*,int,sqlite3_value**), | |
4306 | void (*xStep)(sqlite3_context*,int,sqlite3_value**), | |
4307 | void (*xFinal)(sqlite3_context*), | |
4308 | void(*xDestroy)(void*) | |
4309 | ); | |
5783a860 AC |
4310 | |
4311 | /* | |
08b809f9 | 4312 | ** CAPI3REF: Text Encodings |
5783a860 AC |
4313 | ** |
4314 | ** These constant define integer codes that represent the various | |
4315 | ** text encodings supported by SQLite. | |
4316 | */ | |
08b809f9 EM |
4317 | #define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ |
4318 | #define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ | |
4319 | #define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ | |
5783a860 | 4320 | #define SQLITE_UTF16 4 /* Use native byte order */ |
08b809f9 | 4321 | #define SQLITE_ANY 5 /* Deprecated */ |
5783a860 AC |
4322 | #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ |
4323 | ||
4324 | /* | |
08b809f9 | 4325 | ** CAPI3REF: Function Flags |
5783a860 | 4326 | ** |
08b809f9 EM |
4327 | ** These constants may be ORed together with the |
4328 | ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument | |
4329 | ** to [sqlite3_create_function()], [sqlite3_create_function16()], or | |
4330 | ** [sqlite3_create_function_v2()]. | |
5783a860 | 4331 | */ |
08b809f9 EM |
4332 | #define SQLITE_DETERMINISTIC 0x800 |
4333 | ||
4334 | /* | |
4335 | ** CAPI3REF: Deprecated Functions | |
4336 | ** DEPRECATED | |
4337 | ** | |
4338 | ** These functions are [deprecated]. In order to maintain | |
4339 | ** backwards compatibility with older code, these functions continue | |
4340 | ** to be supported. However, new applications should avoid | |
4341 | ** the use of these functions. To encourage programmers to avoid | |
4342 | ** these functions, we will not explain what they do. | |
4343 | */ | |
4344 | #ifndef SQLITE_OMIT_DEPRECATED | |
4345 | SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_aggregate_count(sqlite3_context*); | |
4346 | SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_expired(sqlite3_stmt*); | |
4347 | SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); | |
4348 | SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_global_recover(void); | |
4349 | SQLITE_API SQLITE_DEPRECATED void SQLITE_STDCALL sqlite3_thread_cleanup(void); | |
4350 | SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), | |
4351 | void*,sqlite3_int64); | |
4352 | #endif | |
5783a860 AC |
4353 | |
4354 | /* | |
08b809f9 EM |
4355 | ** CAPI3REF: Obtaining SQL Values |
4356 | ** METHOD: sqlite3_value | |
5783a860 AC |
4357 | ** |
4358 | ** The C-language implementation of SQL functions and aggregates uses | |
4359 | ** this set of interface routines to access the parameter values on | |
08b809f9 | 4360 | ** the function or aggregate. |
5783a860 AC |
4361 | ** |
4362 | ** The xFunc (for scalar functions) or xStep (for aggregates) parameters | |
4363 | ** to [sqlite3_create_function()] and [sqlite3_create_function16()] | |
4364 | ** define callbacks that implement the SQL functions and aggregates. | |
08b809f9 | 4365 | ** The 3rd parameter to these callbacks is an array of pointers to |
5783a860 AC |
4366 | ** [protected sqlite3_value] objects. There is one [sqlite3_value] object for |
4367 | ** each parameter to the SQL function. These routines are used to | |
4368 | ** extract values from the [sqlite3_value] objects. | |
4369 | ** | |
4370 | ** These routines work only with [protected sqlite3_value] objects. | |
4371 | ** Any attempt to use these routines on an [unprotected sqlite3_value] | |
4372 | ** object results in undefined behavior. | |
4373 | ** | |
08b809f9 EM |
4374 | ** ^These routines work just like the corresponding [column access functions] |
4375 | ** except that these routines take a single [protected sqlite3_value] object | |
4376 | ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. | |
5783a860 | 4377 | ** |
08b809f9 EM |
4378 | ** ^The sqlite3_value_text16() interface extracts a UTF-16 string |
4379 | ** in the native byte-order of the host machine. ^The | |
5783a860 | 4380 | ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces |
08b809f9 | 4381 | ** extract UTF-16 strings as big-endian and little-endian respectively. |
5783a860 | 4382 | ** |
08b809f9 | 4383 | ** ^(The sqlite3_value_numeric_type() interface attempts to apply |
5783a860 AC |
4384 | ** numeric affinity to the value. This means that an attempt is |
4385 | ** made to convert the value to an integer or floating point. If | |
4386 | ** such a conversion is possible without loss of information (in other | |
08b809f9 EM |
4387 | ** words, if the value is a string that looks like a number) |
4388 | ** then the conversion is performed. Otherwise no conversion occurs. | |
4389 | ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ | |
5783a860 | 4390 | ** |
08b809f9 EM |
4391 | ** Please pay particular attention to the fact that the pointer returned |
4392 | ** from [sqlite3_value_blob()], [sqlite3_value_text()], or | |
5783a860 AC |
4393 | ** [sqlite3_value_text16()] can be invalidated by a subsequent call to |
4394 | ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], | |
4094d2fa | 4395 | ** or [sqlite3_value_text16()]. |
5783a860 AC |
4396 | ** |
4397 | ** These routines must be called from the same thread as | |
4398 | ** the SQL function that supplied the [sqlite3_value*] parameters. | |
08b809f9 EM |
4399 | */ |
4400 | SQLITE_API const void *SQLITE_STDCALL sqlite3_value_blob(sqlite3_value*); | |
4401 | SQLITE_API int SQLITE_STDCALL sqlite3_value_bytes(sqlite3_value*); | |
4402 | SQLITE_API int SQLITE_STDCALL sqlite3_value_bytes16(sqlite3_value*); | |
4403 | SQLITE_API double SQLITE_STDCALL sqlite3_value_double(sqlite3_value*); | |
4404 | SQLITE_API int SQLITE_STDCALL sqlite3_value_int(sqlite3_value*); | |
4405 | SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_value_int64(sqlite3_value*); | |
4406 | SQLITE_API const unsigned char *SQLITE_STDCALL sqlite3_value_text(sqlite3_value*); | |
4407 | SQLITE_API const void *SQLITE_STDCALL sqlite3_value_text16(sqlite3_value*); | |
4408 | SQLITE_API const void *SQLITE_STDCALL sqlite3_value_text16le(sqlite3_value*); | |
4409 | SQLITE_API const void *SQLITE_STDCALL sqlite3_value_text16be(sqlite3_value*); | |
4410 | SQLITE_API int SQLITE_STDCALL sqlite3_value_type(sqlite3_value*); | |
4411 | SQLITE_API int SQLITE_STDCALL sqlite3_value_numeric_type(sqlite3_value*); | |
4412 | ||
4413 | /* | |
4414 | ** CAPI3REF: Finding The Subtype Of SQL Values | |
4415 | ** METHOD: sqlite3_value | |
4416 | ** | |
4417 | ** The sqlite3_value_subtype(V) function returns the subtype for | |
4418 | ** an [application-defined SQL function] argument V. The subtype | |
4419 | ** information can be used to pass a limited amount of context from | |
4420 | ** one SQL function to another. Use the [sqlite3_result_subtype()] | |
4421 | ** routine to set the subtype for the return value of an SQL function. | |
4422 | ** | |
4423 | ** SQLite makes no use of subtype itself. It merely passes the subtype | |
4424 | ** from the result of one [application-defined SQL function] into the | |
4425 | ** input of another. | |
4426 | */ | |
4427 | SQLITE_API unsigned int SQLITE_STDCALL sqlite3_value_subtype(sqlite3_value*); | |
4428 | ||
4429 | /* | |
4430 | ** CAPI3REF: Copy And Free SQL Values | |
4431 | ** METHOD: sqlite3_value | |
4432 | ** | |
4433 | ** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] | |
4434 | ** object D and returns a pointer to that copy. ^The [sqlite3_value] returned | |
4435 | ** is a [protected sqlite3_value] object even if the input is not. | |
4436 | ** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a | |
4437 | ** memory allocation fails. | |
4438 | ** | |
4439 | ** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object | |
4440 | ** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer | |
4441 | ** then sqlite3_value_free(V) is a harmless no-op. | |
4442 | */ | |
4443 | SQLITE_API sqlite3_value *SQLITE_STDCALL sqlite3_value_dup(const sqlite3_value*); | |
4444 | SQLITE_API void SQLITE_STDCALL sqlite3_value_free(sqlite3_value*); | |
4445 | ||
4446 | /* | |
4447 | ** CAPI3REF: Obtain Aggregate Function Context | |
4448 | ** METHOD: sqlite3_context | |
4449 | ** | |
4450 | ** Implementations of aggregate SQL functions use this | |
4451 | ** routine to allocate memory for storing their state. | |
4452 | ** | |
4453 | ** ^The first time the sqlite3_aggregate_context(C,N) routine is called | |
4454 | ** for a particular aggregate function, SQLite | |
4455 | ** allocates N of memory, zeroes out that memory, and returns a pointer | |
4456 | ** to the new memory. ^On second and subsequent calls to | |
4457 | ** sqlite3_aggregate_context() for the same aggregate function instance, | |
4458 | ** the same buffer is returned. Sqlite3_aggregate_context() is normally | |
4459 | ** called once for each invocation of the xStep callback and then one | |
4460 | ** last time when the xFinal callback is invoked. ^(When no rows match | |
4461 | ** an aggregate query, the xStep() callback of the aggregate function | |
4462 | ** implementation is never called and xFinal() is called exactly once. | |
4463 | ** In those cases, sqlite3_aggregate_context() might be called for the | |
4464 | ** first time from within xFinal().)^ | |
4465 | ** | |
4466 | ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer | |
4467 | ** when first called if N is less than or equal to zero or if a memory | |
4468 | ** allocate error occurs. | |
4469 | ** | |
4470 | ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is | |
4471 | ** determined by the N parameter on first successful call. Changing the | |
4472 | ** value of N in subsequent call to sqlite3_aggregate_context() within | |
4473 | ** the same aggregate function instance will not resize the memory | |
4474 | ** allocation.)^ Within the xFinal callback, it is customary to set | |
4475 | ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no | |
4476 | ** pointless memory allocations occur. | |
4477 | ** | |
4478 | ** ^SQLite automatically frees the memory allocated by | |
4479 | ** sqlite3_aggregate_context() when the aggregate query concludes. | |
4480 | ** | |
4481 | ** The first parameter must be a copy of the | |
4482 | ** [sqlite3_context | SQL function context] that is the first parameter | |
4483 | ** to the xStep or xFinal callback routine that implements the aggregate | |
5783a860 AC |
4484 | ** function. |
4485 | ** | |
4486 | ** This routine must be called from the same thread in which | |
4487 | ** the aggregate SQL function is running. | |
5783a860 | 4488 | */ |
08b809f9 | 4489 | SQLITE_API void *SQLITE_STDCALL sqlite3_aggregate_context(sqlite3_context*, int nBytes); |
5783a860 AC |
4490 | |
4491 | /* | |
08b809f9 EM |
4492 | ** CAPI3REF: User Data For Functions |
4493 | ** METHOD: sqlite3_context | |
5783a860 | 4494 | ** |
08b809f9 | 4495 | ** ^The sqlite3_user_data() interface returns a copy of |
5783a860 | 4496 | ** the pointer that was the pUserData parameter (the 5th parameter) |
08b809f9 | 4497 | ** of the [sqlite3_create_function()] |
5783a860 | 4498 | ** and [sqlite3_create_function16()] routines that originally |
08b809f9 | 4499 | ** registered the application defined function. |
5783a860 AC |
4500 | ** |
4501 | ** This routine must be called from the same thread in which | |
4502 | ** the application-defined function is running. | |
5783a860 | 4503 | */ |
08b809f9 | 4504 | SQLITE_API void *SQLITE_STDCALL sqlite3_user_data(sqlite3_context*); |
5783a860 AC |
4505 | |
4506 | /* | |
08b809f9 EM |
4507 | ** CAPI3REF: Database Connection For Functions |
4508 | ** METHOD: sqlite3_context | |
5783a860 | 4509 | ** |
08b809f9 | 4510 | ** ^The sqlite3_context_db_handle() interface returns a copy of |
5783a860 | 4511 | ** the pointer to the [database connection] (the 1st parameter) |
08b809f9 | 4512 | ** of the [sqlite3_create_function()] |
5783a860 AC |
4513 | ** and [sqlite3_create_function16()] routines that originally |
4514 | ** registered the application defined function. | |
5783a860 | 4515 | */ |
08b809f9 | 4516 | SQLITE_API sqlite3 *SQLITE_STDCALL sqlite3_context_db_handle(sqlite3_context*); |
5783a860 AC |
4517 | |
4518 | /* | |
08b809f9 EM |
4519 | ** CAPI3REF: Function Auxiliary Data |
4520 | ** METHOD: sqlite3_context | |
5783a860 | 4521 | ** |
08b809f9 EM |
4522 | ** These functions may be used by (non-aggregate) SQL functions to |
4523 | ** associate metadata with argument values. If the same value is passed to | |
5783a860 | 4524 | ** multiple invocations of the same SQL function during query execution, under |
08b809f9 EM |
4525 | ** some circumstances the associated metadata may be preserved. An example |
4526 | ** of where this might be useful is in a regular-expression matching | |
4527 | ** function. The compiled version of the regular expression can be stored as | |
4528 | ** metadata associated with the pattern string. | |
4529 | ** Then as long as the pattern string remains the same, | |
4530 | ** the compiled regular expression can be reused on multiple | |
4531 | ** invocations of the same function. | |
4532 | ** | |
4533 | ** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata | |
5783a860 | 4534 | ** associated by the sqlite3_set_auxdata() function with the Nth argument |
08b809f9 EM |
4535 | ** value to the application-defined function. ^If there is no metadata |
4536 | ** associated with the function argument, this sqlite3_get_auxdata() interface | |
5783a860 AC |
4537 | ** returns a NULL pointer. |
4538 | ** | |
08b809f9 EM |
4539 | ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th |
4540 | ** argument of the application-defined function. ^Subsequent | |
4541 | ** calls to sqlite3_get_auxdata(C,N) return P from the most recent | |
4542 | ** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or | |
4543 | ** NULL if the metadata has been discarded. | |
4544 | ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, | |
4545 | ** SQLite will invoke the destructor function X with parameter P exactly | |
4546 | ** once, when the metadata is discarded. | |
4547 | ** SQLite is free to discard the metadata at any time, including: <ul> | |
4548 | ** <li> when the corresponding function parameter changes, or | |
4549 | ** <li> when [sqlite3_reset()] or [sqlite3_finalize()] is called for the | |
4550 | ** SQL statement, or | |
4551 | ** <li> when sqlite3_set_auxdata() is invoked again on the same parameter, or | |
4552 | ** <li> during the original sqlite3_set_auxdata() call when a memory | |
4553 | ** allocation error occurs. </ul>)^ | |
4554 | ** | |
4555 | ** Note the last bullet in particular. The destructor X in | |
4556 | ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the | |
4557 | ** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() | |
4558 | ** should be called near the end of the function implementation and the | |
4559 | ** function implementation should not make any use of P after | |
4560 | ** sqlite3_set_auxdata() has been called. | |
4561 | ** | |
4562 | ** ^(In practice, metadata is preserved between function calls for | |
4563 | ** function parameters that are compile-time constants, including literal | |
4564 | ** values and [parameters] and expressions composed from the same.)^ | |
5783a860 AC |
4565 | ** |
4566 | ** These routines must be called from the same thread in which | |
4567 | ** the SQL function is running. | |
5783a860 | 4568 | */ |
08b809f9 EM |
4569 | SQLITE_API void *SQLITE_STDCALL sqlite3_get_auxdata(sqlite3_context*, int N); |
4570 | SQLITE_API void SQLITE_STDCALL sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); | |
5783a860 AC |
4571 | |
4572 | ||
4573 | /* | |
08b809f9 | 4574 | ** CAPI3REF: Constants Defining Special Destructor Behavior |
5783a860 | 4575 | ** |
08b809f9 EM |
4576 | ** These are special values for the destructor that is passed in as the |
4577 | ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor | |
5783a860 | 4578 | ** argument is SQLITE_STATIC, it means that the content pointer is constant |
08b809f9 | 4579 | ** and will never change. It does not need to be destroyed. ^The |
5783a860 AC |
4580 | ** SQLITE_TRANSIENT value means that the content will likely change in |
4581 | ** the near future and that SQLite should make its own private copy of | |
4582 | ** the content before returning. | |
4583 | ** | |
4584 | ** The typedef is necessary to work around problems in certain | |
08b809f9 | 4585 | ** C++ compilers. |
5783a860 AC |
4586 | */ |
4587 | typedef void (*sqlite3_destructor_type)(void*); | |
4588 | #define SQLITE_STATIC ((sqlite3_destructor_type)0) | |
4589 | #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) | |
4590 | ||
4591 | /* | |
08b809f9 EM |
4592 | ** CAPI3REF: Setting The Result Of An SQL Function |
4593 | ** METHOD: sqlite3_context | |
5783a860 AC |
4594 | ** |
4595 | ** These routines are used by the xFunc or xFinal callbacks that | |
4596 | ** implement SQL functions and aggregates. See | |
4597 | ** [sqlite3_create_function()] and [sqlite3_create_function16()] | |
4598 | ** for additional information. | |
4599 | ** | |
08b809f9 EM |
4600 | ** These functions work very much like the [parameter binding] family of |
4601 | ** functions used to bind values to host parameters in prepared statements. | |
4602 | ** Refer to the [SQL parameter] documentation for additional information. | |
5783a860 | 4603 | ** |
08b809f9 EM |
4604 | ** ^The sqlite3_result_blob() interface sets the result from |
4605 | ** an application-defined function to be the BLOB whose content is pointed | |
5783a860 | 4606 | ** to by the second parameter and which is N bytes long where N is the |
4094d2fa | 4607 | ** third parameter. |
5783a860 | 4608 | ** |
08b809f9 EM |
4609 | ** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) |
4610 | ** interfaces set the result of the application-defined function to be | |
4611 | ** a BLOB containing all zero bytes and N bytes in size. | |
4612 | ** | |
4613 | ** ^The sqlite3_result_double() interface sets the result from | |
4614 | ** an application-defined function to be a floating point value specified | |
5783a860 AC |
4615 | ** by its 2nd argument. |
4616 | ** | |
08b809f9 | 4617 | ** ^The sqlite3_result_error() and sqlite3_result_error16() functions |
5783a860 | 4618 | ** cause the implemented SQL function to throw an exception. |
08b809f9 | 4619 | ** ^SQLite uses the string pointed to by the |
5783a860 | 4620 | ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() |
08b809f9 EM |
4621 | ** as the text of an error message. ^SQLite interprets the error |
4622 | ** message string from sqlite3_result_error() as UTF-8. ^SQLite | |
4623 | ** interprets the string from sqlite3_result_error16() as UTF-16 in native | |
4624 | ** byte order. ^If the third parameter to sqlite3_result_error() | |
5783a860 AC |
4625 | ** or sqlite3_result_error16() is negative then SQLite takes as the error |
4626 | ** message all text up through the first zero character. | |
08b809f9 | 4627 | ** ^If the third parameter to sqlite3_result_error() or |
5783a860 AC |
4628 | ** sqlite3_result_error16() is non-negative then SQLite takes that many |
4629 | ** bytes (not characters) from the 2nd parameter as the error message. | |
08b809f9 EM |
4630 | ** ^The sqlite3_result_error() and sqlite3_result_error16() |
4631 | ** routines make a private copy of the error message text before | |
5783a860 AC |
4632 | ** they return. Hence, the calling function can deallocate or |
4633 | ** modify the text after they return without harm. | |
08b809f9 EM |
4634 | ** ^The sqlite3_result_error_code() function changes the error code |
4635 | ** returned by SQLite as a result of an error in a function. ^By default, | |
4636 | ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() | |
5783a860 AC |
4637 | ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. |
4638 | ** | |
08b809f9 EM |
4639 | ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an |
4640 | ** error indicating that a string or BLOB is too long to represent. | |
5783a860 | 4641 | ** |
08b809f9 EM |
4642 | ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an |
4643 | ** error indicating that a memory allocation failed. | |
4644 | ** | |
4645 | ** ^The sqlite3_result_int() interface sets the return value | |
5783a860 AC |
4646 | ** of the application-defined function to be the 32-bit signed integer |
4647 | ** value given in the 2nd argument. | |
08b809f9 | 4648 | ** ^The sqlite3_result_int64() interface sets the return value |
5783a860 AC |
4649 | ** of the application-defined function to be the 64-bit signed integer |
4650 | ** value given in the 2nd argument. | |
4651 | ** | |
08b809f9 | 4652 | ** ^The sqlite3_result_null() interface sets the return value |
5783a860 AC |
4653 | ** of the application-defined function to be NULL. |
4654 | ** | |
08b809f9 | 4655 | ** ^The sqlite3_result_text(), sqlite3_result_text16(), |
5783a860 AC |
4656 | ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces |
4657 | ** set the return value of the application-defined function to be | |
4658 | ** a text string which is represented as UTF-8, UTF-16 native byte order, | |
4659 | ** UTF-16 little endian, or UTF-16 big endian, respectively. | |
08b809f9 EM |
4660 | ** ^The sqlite3_result_text64() interface sets the return value of an |
4661 | ** application-defined function to be a text string in an encoding | |
4662 | ** specified by the fifth (and last) parameter, which must be one | |
4663 | ** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. | |
4664 | ** ^SQLite takes the text result from the application from | |
5783a860 | 4665 | ** the 2nd parameter of the sqlite3_result_text* interfaces. |
08b809f9 | 4666 | ** ^If the 3rd parameter to the sqlite3_result_text* interfaces |
4094d2fa | 4667 | ** is negative, then SQLite takes result text from the 2nd parameter |
5783a860 | 4668 | ** through the first zero character. |
08b809f9 | 4669 | ** ^If the 3rd parameter to the sqlite3_result_text* interfaces |
5783a860 AC |
4670 | ** is non-negative, then as many bytes (not characters) of the text |
4671 | ** pointed to by the 2nd parameter are taken as the application-defined | |
08b809f9 EM |
4672 | ** function result. If the 3rd parameter is non-negative, then it |
4673 | ** must be the byte offset into the string where the NUL terminator would | |
4674 | ** appear if the string where NUL terminated. If any NUL characters occur | |
4675 | ** in the string at a byte offset that is less than the value of the 3rd | |
4676 | ** parameter, then the resulting string will contain embedded NULs and the | |
4677 | ** result of expressions operating on strings with embedded NULs is undefined. | |
4678 | ** ^If the 4th parameter to the sqlite3_result_text* interfaces | |
5783a860 | 4679 | ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that |
08b809f9 | 4680 | ** function as the destructor on the text or BLOB result when it has |
5783a860 | 4681 | ** finished using that result. |
08b809f9 EM |
4682 | ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to |
4683 | ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite | |
4684 | ** assumes that the text or BLOB result is in constant space and does not | |
4685 | ** copy the content of the parameter nor call a destructor on the content | |
4686 | ** when it has finished using that result. | |
4687 | ** ^If the 4th parameter to the sqlite3_result_text* interfaces | |
5783a860 AC |
4688 | ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT |
4689 | ** then SQLite makes a copy of the result into space obtained from | |
4690 | ** from [sqlite3_malloc()] before it returns. | |
4691 | ** | |
08b809f9 EM |
4692 | ** ^The sqlite3_result_value() interface sets the result of |
4693 | ** the application-defined function to be a copy of the | |
4694 | ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The | |
5783a860 | 4695 | ** sqlite3_result_value() interface makes a copy of the [sqlite3_value] |
08b809f9 | 4696 | ** so that the [sqlite3_value] specified in the parameter may change or |
5783a860 | 4697 | ** be deallocated after sqlite3_result_value() returns without harm. |
08b809f9 | 4698 | ** ^A [protected sqlite3_value] object may always be used where an |
5783a860 AC |
4699 | ** [unprotected sqlite3_value] object is required, so either |
4700 | ** kind of [sqlite3_value] object can be used with this interface. | |
4701 | ** | |
4094d2fa | 4702 | ** If these routines are called from within the different thread |
08b809f9 | 4703 | ** than the one containing the application-defined function that received |
5783a860 | 4704 | ** the [sqlite3_context] pointer, the results are undefined. |
08b809f9 EM |
4705 | */ |
4706 | SQLITE_API void SQLITE_STDCALL sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); | |
4707 | SQLITE_API void SQLITE_STDCALL sqlite3_result_blob64(sqlite3_context*,const void*, | |
4708 | sqlite3_uint64,void(*)(void*)); | |
4709 | SQLITE_API void SQLITE_STDCALL sqlite3_result_double(sqlite3_context*, double); | |
4710 | SQLITE_API void SQLITE_STDCALL sqlite3_result_error(sqlite3_context*, const char*, int); | |
4711 | SQLITE_API void SQLITE_STDCALL sqlite3_result_error16(sqlite3_context*, const void*, int); | |
4712 | SQLITE_API void SQLITE_STDCALL sqlite3_result_error_toobig(sqlite3_context*); | |
4713 | SQLITE_API void SQLITE_STDCALL sqlite3_result_error_nomem(sqlite3_context*); | |
4714 | SQLITE_API void SQLITE_STDCALL sqlite3_result_error_code(sqlite3_context*, int); | |
4715 | SQLITE_API void SQLITE_STDCALL sqlite3_result_int(sqlite3_context*, int); | |
4716 | SQLITE_API void SQLITE_STDCALL sqlite3_result_int64(sqlite3_context*, sqlite3_int64); | |
4717 | SQLITE_API void SQLITE_STDCALL sqlite3_result_null(sqlite3_context*); | |
4718 | SQLITE_API void SQLITE_STDCALL sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); | |
4719 | SQLITE_API void SQLITE_STDCALL sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, | |
4720 | void(*)(void*), unsigned char encoding); | |
4721 | SQLITE_API void SQLITE_STDCALL sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); | |
4722 | SQLITE_API void SQLITE_STDCALL sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); | |
4723 | SQLITE_API void SQLITE_STDCALL sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); | |
4724 | SQLITE_API void SQLITE_STDCALL sqlite3_result_value(sqlite3_context*, sqlite3_value*); | |
4725 | SQLITE_API void SQLITE_STDCALL sqlite3_result_zeroblob(sqlite3_context*, int n); | |
4726 | SQLITE_API int SQLITE_STDCALL sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); | |
4727 | ||
4728 | ||
4729 | /* | |
4730 | ** CAPI3REF: Setting The Subtype Of An SQL Function | |
4731 | ** METHOD: sqlite3_context | |
4732 | ** | |
4733 | ** The sqlite3_result_subtype(C,T) function causes the subtype of | |
4734 | ** the result from the [application-defined SQL function] with | |
4735 | ** [sqlite3_context] C to be the value T. Only the lower 8 bits | |
4736 | ** of the subtype T are preserved in current versions of SQLite; | |
4737 | ** higher order bits are discarded. | |
4738 | ** The number of subtype bytes preserved by SQLite might increase | |
4739 | ** in future releases of SQLite. | |
4740 | */ | |
4741 | SQLITE_API void SQLITE_STDCALL sqlite3_result_subtype(sqlite3_context*,unsigned int); | |
4742 | ||
4743 | /* | |
4744 | ** CAPI3REF: Define New Collating Sequences | |
4745 | ** METHOD: sqlite3 | |
4746 | ** | |
4747 | ** ^These functions add, remove, or modify a [collation] associated | |
4748 | ** with the [database connection] specified as the first argument. | |
5783a860 | 4749 | ** |
08b809f9 | 4750 | ** ^The name of the collation is a UTF-8 string |
5783a860 | 4751 | ** for sqlite3_create_collation() and sqlite3_create_collation_v2() |
08b809f9 EM |
4752 | ** and a UTF-16 string in native byte order for sqlite3_create_collation16(). |
4753 | ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are | |
4754 | ** considered to be the same name. | |
4755 | ** | |
4756 | ** ^(The third argument (eTextRep) must be one of the constants: | |
4757 | ** <ul> | |
4758 | ** <li> [SQLITE_UTF8], | |
4759 | ** <li> [SQLITE_UTF16LE], | |
4760 | ** <li> [SQLITE_UTF16BE], | |
4761 | ** <li> [SQLITE_UTF16], or | |
4762 | ** <li> [SQLITE_UTF16_ALIGNED]. | |
4763 | ** </ul>)^ | |
4764 | ** ^The eTextRep argument determines the encoding of strings passed | |
4765 | ** to the collating function callback, xCallback. | |
4766 | ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep | |
4767 | ** force strings to be UTF16 with native byte order. | |
4768 | ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin | |
4769 | ** on an even byte address. | |
4770 | ** | |
4771 | ** ^The fourth argument, pArg, is an application data pointer that is passed | |
4772 | ** through as the first argument to the collating function callback. | |
4773 | ** | |
4774 | ** ^The fifth argument, xCallback, is a pointer to the collating function. | |
4775 | ** ^Multiple collating functions can be registered using the same name but | |
4776 | ** with different eTextRep parameters and SQLite will use whichever | |
4777 | ** function requires the least amount of data transformation. | |
4778 | ** ^If the xCallback argument is NULL then the collating function is | |
4779 | ** deleted. ^When all collating functions having the same name are deleted, | |
4780 | ** that collation is no longer usable. | |
4781 | ** | |
4782 | ** ^The collating function callback is invoked with a copy of the pArg | |
4783 | ** application data pointer and with two strings in the encoding specified | |
4784 | ** by the eTextRep argument. The collating function must return an | |
4785 | ** integer that is negative, zero, or positive | |
4786 | ** if the first string is less than, equal to, or greater than the second, | |
4787 | ** respectively. A collating function must always return the same answer | |
4788 | ** given the same inputs. If two or more collating functions are registered | |
4789 | ** to the same collation name (using different eTextRep values) then all | |
4790 | ** must give an equivalent answer when invoked with equivalent strings. | |
4791 | ** The collating function must obey the following properties for all | |
4792 | ** strings A, B, and C: | |
4793 | ** | |
4794 | ** <ol> | |
4795 | ** <li> If A==B then B==A. | |
4796 | ** <li> If A==B and B==C then A==C. | |
4797 | ** <li> If A<B THEN B>A. | |
4798 | ** <li> If A<B and B<C then A<C. | |
4799 | ** </ol> | |
4800 | ** | |
4801 | ** If a collating function fails any of the above constraints and that | |
4802 | ** collating function is registered and used, then the behavior of SQLite | |
4803 | ** is undefined. | |
4804 | ** | |
4805 | ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() | |
4806 | ** with the addition that the xDestroy callback is invoked on pArg when | |
4807 | ** the collating function is deleted. | |
4808 | ** ^Collating functions are deleted when they are overridden by later | |
4809 | ** calls to the collation creation functions or when the | |
4810 | ** [database connection] is closed using [sqlite3_close()]. | |
4811 | ** | |
4812 | ** ^The xDestroy callback is <u>not</u> called if the | |
4813 | ** sqlite3_create_collation_v2() function fails. Applications that invoke | |
4814 | ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should | |
4815 | ** check the return code and dispose of the application data pointer | |
4816 | ** themselves rather than expecting SQLite to deal with it for them. | |
4817 | ** This is different from every other SQLite interface. The inconsistency | |
4818 | ** is unfortunate but cannot be changed without breaking backwards | |
4819 | ** compatibility. | |
4820 | ** | |
4821 | ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. | |
4822 | */ | |
4823 | SQLITE_API int SQLITE_STDCALL sqlite3_create_collation( | |
4824 | sqlite3*, | |
4825 | const char *zName, | |
4826 | int eTextRep, | |
4827 | void *pArg, | |
5783a860 AC |
4828 | int(*xCompare)(void*,int,const void*,int,const void*) |
4829 | ); | |
08b809f9 EM |
4830 | SQLITE_API int SQLITE_STDCALL sqlite3_create_collation_v2( |
4831 | sqlite3*, | |
4832 | const char *zName, | |
4833 | int eTextRep, | |
4834 | void *pArg, | |
5783a860 AC |
4835 | int(*xCompare)(void*,int,const void*,int,const void*), |
4836 | void(*xDestroy)(void*) | |
4837 | ); | |
08b809f9 EM |
4838 | SQLITE_API int SQLITE_STDCALL sqlite3_create_collation16( |
4839 | sqlite3*, | |
4840 | const void *zName, | |
4841 | int eTextRep, | |
4842 | void *pArg, | |
5783a860 AC |
4843 | int(*xCompare)(void*,int,const void*,int,const void*) |
4844 | ); | |
4845 | ||
4846 | /* | |
08b809f9 EM |
4847 | ** CAPI3REF: Collation Needed Callbacks |
4848 | ** METHOD: sqlite3 | |
5783a860 | 4849 | ** |
08b809f9 | 4850 | ** ^To avoid having to register all collation sequences before a database |
5783a860 | 4851 | ** can be used, a single callback function may be registered with the |
08b809f9 EM |
4852 | ** [database connection] to be invoked whenever an undefined collation |
4853 | ** sequence is required. | |
5783a860 | 4854 | ** |
08b809f9 | 4855 | ** ^If the function is registered using the sqlite3_collation_needed() API, |
5783a860 | 4856 | ** then it is passed the names of undefined collation sequences as strings |
08b809f9 EM |
4857 | ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, |
4858 | ** the names are passed as UTF-16 in machine native byte order. | |
4859 | ** ^A call to either function replaces the existing collation-needed callback. | |
5783a860 | 4860 | ** |
08b809f9 | 4861 | ** ^(When the callback is invoked, the first argument passed is a copy |
5783a860 AC |
4862 | ** of the second argument to sqlite3_collation_needed() or |
4863 | ** sqlite3_collation_needed16(). The second argument is the database | |
08b809f9 EM |
4864 | ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], |
4865 | ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation | |
4866 | ** sequence function required. The fourth parameter is the name of the | |
4867 | ** required collation sequence.)^ | |
5783a860 AC |
4868 | ** |
4869 | ** The callback function should register the desired collation using | |
4870 | ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or | |
4871 | ** [sqlite3_create_collation_v2()]. | |
5783a860 | 4872 | */ |
08b809f9 EM |
4873 | SQLITE_API int SQLITE_STDCALL sqlite3_collation_needed( |
4874 | sqlite3*, | |
4875 | void*, | |
5783a860 AC |
4876 | void(*)(void*,sqlite3*,int eTextRep,const char*) |
4877 | ); | |
08b809f9 EM |
4878 | SQLITE_API int SQLITE_STDCALL sqlite3_collation_needed16( |
4879 | sqlite3*, | |
5783a860 AC |
4880 | void*, |
4881 | void(*)(void*,sqlite3*,int eTextRep,const void*) | |
4882 | ); | |
4883 | ||
08b809f9 | 4884 | #ifdef SQLITE_HAS_CODEC |
5783a860 AC |
4885 | /* |
4886 | ** Specify the key for an encrypted database. This routine should be | |
4887 | ** called right after sqlite3_open(). | |
4888 | ** | |
4889 | ** The code to implement this API is not available in the public release | |
4890 | ** of SQLite. | |
4891 | */ | |
08b809f9 EM |
4892 | SQLITE_API int SQLITE_STDCALL sqlite3_key( |
4893 | sqlite3 *db, /* Database to be rekeyed */ | |
4894 | const void *pKey, int nKey /* The key */ | |
4895 | ); | |
4896 | SQLITE_API int SQLITE_STDCALL sqlite3_key_v2( | |
5783a860 | 4897 | sqlite3 *db, /* Database to be rekeyed */ |
08b809f9 | 4898 | const char *zDbName, /* Name of the database */ |
5783a860 AC |
4899 | const void *pKey, int nKey /* The key */ |
4900 | ); | |
4901 | ||
4902 | /* | |
4903 | ** Change the key on an open database. If the current database is not | |
4904 | ** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the | |
4905 | ** database is decrypted. | |
4906 | ** | |
4907 | ** The code to implement this API is not available in the public release | |
4908 | ** of SQLite. | |
4909 | */ | |
08b809f9 | 4910 | SQLITE_API int SQLITE_STDCALL sqlite3_rekey( |
5783a860 AC |
4911 | sqlite3 *db, /* Database to be rekeyed */ |
4912 | const void *pKey, int nKey /* The new key */ | |
4913 | ); | |
08b809f9 EM |
4914 | SQLITE_API int SQLITE_STDCALL sqlite3_rekey_v2( |
4915 | sqlite3 *db, /* Database to be rekeyed */ | |
4916 | const char *zDbName, /* Name of the database */ | |
4917 | const void *pKey, int nKey /* The new key */ | |
4918 | ); | |
4919 | ||
4920 | /* | |
4921 | ** Specify the activation key for a SEE database. Unless | |
4922 | ** activated, none of the SEE routines will work. | |
4923 | */ | |
4924 | SQLITE_API void SQLITE_STDCALL sqlite3_activate_see( | |
4925 | const char *zPassPhrase /* Activation phrase */ | |
4926 | ); | |
4927 | #endif | |
4928 | ||
4929 | #ifdef SQLITE_ENABLE_CEROD | |
4930 | /* | |
4931 | ** Specify the activation key for a CEROD database. Unless | |
4932 | ** activated, none of the CEROD routines will work. | |
4933 | */ | |
4934 | SQLITE_API void SQLITE_STDCALL sqlite3_activate_cerod( | |
4935 | const char *zPassPhrase /* Activation phrase */ | |
4936 | ); | |
4937 | #endif | |
5783a860 AC |
4938 | |
4939 | /* | |
08b809f9 | 4940 | ** CAPI3REF: Suspend Execution For A Short Time |
5783a860 | 4941 | ** |
08b809f9 | 4942 | ** The sqlite3_sleep() function causes the current thread to suspend execution |
5783a860 AC |
4943 | ** for at least a number of milliseconds specified in its parameter. |
4944 | ** | |
4094d2fa EM |
4945 | ** If the operating system does not support sleep requests with |
4946 | ** millisecond time resolution, then the time will be rounded up to | |
4947 | ** the nearest second. The number of milliseconds of sleep actually | |
5783a860 AC |
4948 | ** requested from the operating system is returned. |
4949 | ** | |
08b809f9 EM |
4950 | ** ^SQLite implements this interface by calling the xSleep() |
4951 | ** method of the default [sqlite3_vfs] object. If the xSleep() method | |
4952 | ** of the default VFS is not implemented correctly, or not implemented at | |
4953 | ** all, then the behavior of sqlite3_sleep() may deviate from the description | |
4954 | ** in the previous paragraphs. | |
5783a860 | 4955 | */ |
08b809f9 | 4956 | SQLITE_API int SQLITE_STDCALL sqlite3_sleep(int); |
5783a860 AC |
4957 | |
4958 | /* | |
08b809f9 EM |
4959 | ** CAPI3REF: Name Of The Folder Holding Temporary Files |
4960 | ** | |
4961 | ** ^(If this global variable is made to point to a string which is | |
4962 | ** the name of a folder (a.k.a. directory), then all temporary files | |
4963 | ** created by SQLite when using a built-in [sqlite3_vfs | VFS] | |
4964 | ** will be placed in that directory.)^ ^If this variable | |
4965 | ** is a NULL pointer, then SQLite performs a search for an appropriate | |
4966 | ** temporary file directory. | |
4967 | ** | |
4968 | ** Applications are strongly discouraged from using this global variable. | |
4969 | ** It is required to set a temporary folder on Windows Runtime (WinRT). | |
4970 | ** But for all other platforms, it is highly recommended that applications | |
4971 | ** neither read nor write this variable. This global variable is a relic | |
4972 | ** that exists for backwards compatibility of legacy applications and should | |
4973 | ** be avoided in new projects. | |
4974 | ** | |
4975 | ** It is not safe to read or modify this variable in more than one | |
4976 | ** thread at a time. It is not safe to read or modify this variable | |
4977 | ** if a [database connection] is being used at the same time in a separate | |
4978 | ** thread. | |
4979 | ** It is intended that this variable be set once | |
4980 | ** as part of process initialization and before any SQLite interface | |
4981 | ** routines have been called and that this variable remain unchanged | |
4982 | ** thereafter. | |
4983 | ** | |
4984 | ** ^The [temp_store_directory pragma] may modify this variable and cause | |
4985 | ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, | |
4986 | ** the [temp_store_directory pragma] always assumes that any string | |
4987 | ** that this variable points to is held in memory obtained from | |
4988 | ** [sqlite3_malloc] and the pragma may attempt to free that memory | |
4989 | ** using [sqlite3_free]. | |
4990 | ** Hence, if this variable is modified directly, either it should be | |
4991 | ** made NULL or made to point to memory obtained from [sqlite3_malloc] | |
4992 | ** or else the use of the [temp_store_directory pragma] should be avoided. | |
4993 | ** Except when requested by the [temp_store_directory pragma], SQLite | |
4994 | ** does not free the memory that sqlite3_temp_directory points to. If | |
4995 | ** the application wants that memory to be freed, it must do | |
4996 | ** so itself, taking care to only do so after all [database connection] | |
4997 | ** objects have been destroyed. | |
4998 | ** | |
4999 | ** <b>Note to Windows Runtime users:</b> The temporary directory must be set | |
5000 | ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various | |
5001 | ** features that require the use of temporary files may fail. Here is an | |
5002 | ** example of how to do this using C++ with the Windows Runtime: | |
5783a860 | 5003 | ** |
08b809f9 EM |
5004 | ** <blockquote><pre> |
5005 | ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> | |
5006 | ** TemporaryFolder->Path->Data(); | |
5007 | ** char zPathBuf[MAX_PATH + 1]; | |
5008 | ** memset(zPathBuf, 0, sizeof(zPathBuf)); | |
5009 | ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), | |
5010 | ** NULL, NULL); | |
5011 | ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); | |
5012 | ** </pre></blockquote> | |
5013 | */ | |
5014 | SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; | |
5015 | ||
5016 | /* | |
5017 | ** CAPI3REF: Name Of The Folder Holding Database Files | |
5018 | ** | |
5019 | ** ^(If this global variable is made to point to a string which is | |
5020 | ** the name of a folder (a.k.a. directory), then all database files | |
5021 | ** specified with a relative pathname and created or accessed by | |
5022 | ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed | |
5023 | ** to be relative to that directory.)^ ^If this variable is a NULL | |
5024 | ** pointer, then SQLite assumes that all database files specified | |
5025 | ** with a relative pathname are relative to the current directory | |
5026 | ** for the process. Only the windows VFS makes use of this global | |
5027 | ** variable; it is ignored by the unix VFS. | |
5028 | ** | |
5029 | ** Changing the value of this variable while a database connection is | |
5030 | ** open can result in a corrupt database. | |
5031 | ** | |
5032 | ** It is not safe to read or modify this variable in more than one | |
5033 | ** thread at a time. It is not safe to read or modify this variable | |
5034 | ** if a [database connection] is being used at the same time in a separate | |
5035 | ** thread. | |
5036 | ** It is intended that this variable be set once | |
5783a860 | 5037 | ** as part of process initialization and before any SQLite interface |
08b809f9 EM |
5038 | ** routines have been called and that this variable remain unchanged |
5039 | ** thereafter. | |
5040 | ** | |
5041 | ** ^The [data_store_directory pragma] may modify this variable and cause | |
5042 | ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, | |
5043 | ** the [data_store_directory pragma] always assumes that any string | |
5044 | ** that this variable points to is held in memory obtained from | |
5045 | ** [sqlite3_malloc] and the pragma may attempt to free that memory | |
5046 | ** using [sqlite3_free]. | |
5047 | ** Hence, if this variable is modified directly, either it should be | |
5048 | ** made NULL or made to point to memory obtained from [sqlite3_malloc] | |
5049 | ** or else the use of the [data_store_directory pragma] should be avoided. | |
5783a860 | 5050 | */ |
08b809f9 | 5051 | SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory; |
5783a860 AC |
5052 | |
5053 | /* | |
08b809f9 EM |
5054 | ** CAPI3REF: Test For Auto-Commit Mode |
5055 | ** KEYWORDS: {autocommit mode} | |
5056 | ** METHOD: sqlite3 | |
5783a860 | 5057 | ** |
08b809f9 | 5058 | ** ^The sqlite3_get_autocommit() interface returns non-zero or |
5783a860 | 5059 | ** zero if the given database connection is or is not in autocommit mode, |
08b809f9 EM |
5060 | ** respectively. ^Autocommit mode is on by default. |
5061 | ** ^Autocommit mode is disabled by a [BEGIN] statement. | |
5062 | ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. | |
5783a860 AC |
5063 | ** |
5064 | ** If certain kinds of errors occur on a statement within a multi-statement | |
08b809f9 | 5065 | ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], |
5783a860 AC |
5066 | ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the |
5067 | ** transaction might be rolled back automatically. The only way to | |
08b809f9 | 5068 | ** find out whether SQLite automatically rolled back the transaction after |
5783a860 AC |
5069 | ** an error is to use this function. |
5070 | ** | |
08b809f9 EM |
5071 | ** If another thread changes the autocommit status of the database |
5072 | ** connection while this routine is running, then the return value | |
5073 | ** is undefined. | |
5783a860 | 5074 | */ |
08b809f9 | 5075 | SQLITE_API int SQLITE_STDCALL sqlite3_get_autocommit(sqlite3*); |
5783a860 AC |
5076 | |
5077 | /* | |
08b809f9 EM |
5078 | ** CAPI3REF: Find The Database Handle Of A Prepared Statement |
5079 | ** METHOD: sqlite3_stmt | |
5080 | ** | |
5081 | ** ^The sqlite3_db_handle interface returns the [database connection] handle | |
5082 | ** to which a [prepared statement] belongs. ^The [database connection] | |
5083 | ** returned by sqlite3_db_handle is the same [database connection] | |
5084 | ** that was the first argument | |
5085 | ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to | |
5086 | ** create the statement in the first place. | |
5087 | */ | |
5088 | SQLITE_API sqlite3 *SQLITE_STDCALL sqlite3_db_handle(sqlite3_stmt*); | |
5089 | ||
5090 | /* | |
5091 | ** CAPI3REF: Return The Filename For A Database Connection | |
5092 | ** METHOD: sqlite3 | |
5093 | ** | |
5094 | ** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename | |
5095 | ** associated with database N of connection D. ^The main database file | |
5096 | ** has the name "main". If there is no attached database N on the database | |
5097 | ** connection D, or if database N is a temporary or in-memory database, then | |
5098 | ** a NULL pointer is returned. | |
5099 | ** | |
5100 | ** ^The filename returned by this function is the output of the | |
5101 | ** xFullPathname method of the [VFS]. ^In other words, the filename | |
5102 | ** will be an absolute pathname, even if the filename used | |
5103 | ** to open the database originally was a URI or relative pathname. | |
5104 | */ | |
5105 | SQLITE_API const char *SQLITE_STDCALL sqlite3_db_filename(sqlite3 *db, const char *zDbName); | |
5106 | ||
5107 | /* | |
5108 | ** CAPI3REF: Determine if a database is read-only | |
5109 | ** METHOD: sqlite3 | |
5783a860 | 5110 | ** |
08b809f9 EM |
5111 | ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N |
5112 | ** of connection D is read-only, 0 if it is read/write, or -1 if N is not | |
5113 | ** the name of a database on connection D. | |
5783a860 | 5114 | */ |
08b809f9 | 5115 | SQLITE_API int SQLITE_STDCALL sqlite3_db_readonly(sqlite3 *db, const char *zDbName); |
5783a860 | 5116 | |
08b809f9 EM |
5117 | /* |
5118 | ** CAPI3REF: Find the next prepared statement | |
5119 | ** METHOD: sqlite3 | |
5120 | ** | |
5121 | ** ^This interface returns a pointer to the next [prepared statement] after | |
5122 | ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL | |
5123 | ** then this interface returns a pointer to the first prepared statement | |
5124 | ** associated with the database connection pDb. ^If no prepared statement | |
5125 | ** satisfies the conditions of this routine, it returns NULL. | |
5126 | ** | |
5127 | ** The [database connection] pointer D in a call to | |
5128 | ** [sqlite3_next_stmt(D,S)] must refer to an open database | |
5129 | ** connection and in particular must not be a NULL pointer. | |
5130 | */ | |
5131 | SQLITE_API sqlite3_stmt *SQLITE_STDCALL sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); | |
5783a860 AC |
5132 | |
5133 | /* | |
08b809f9 EM |
5134 | ** CAPI3REF: Commit And Rollback Notification Callbacks |
5135 | ** METHOD: sqlite3 | |
5783a860 | 5136 | ** |
08b809f9 EM |
5137 | ** ^The sqlite3_commit_hook() interface registers a callback |
5138 | ** function to be invoked whenever a transaction is [COMMIT | committed]. | |
5139 | ** ^Any callback set by a previous call to sqlite3_commit_hook() | |
5783a860 | 5140 | ** for the same database connection is overridden. |
08b809f9 EM |
5141 | ** ^The sqlite3_rollback_hook() interface registers a callback |
5142 | ** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. | |
5143 | ** ^Any callback set by a previous call to sqlite3_rollback_hook() | |
5783a860 | 5144 | ** for the same database connection is overridden. |
08b809f9 EM |
5145 | ** ^The pArg argument is passed through to the callback. |
5146 | ** ^If the callback on a commit hook function returns non-zero, | |
5147 | ** then the commit is converted into a rollback. | |
5148 | ** | |
5149 | ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions | |
5150 | ** return the P argument from the previous call of the same function | |
5151 | ** on the same [database connection] D, or NULL for | |
5152 | ** the first call for each function on D. | |
5153 | ** | |
5154 | ** The commit and rollback hook callbacks are not reentrant. | |
5155 | ** The callback implementation must not do anything that will modify | |
5156 | ** the database connection that invoked the callback. Any actions | |
5157 | ** to modify the database connection must be deferred until after the | |
5158 | ** completion of the [sqlite3_step()] call that triggered the commit | |
5159 | ** or rollback hook in the first place. | |
5160 | ** Note that running any other SQL statements, including SELECT statements, | |
5161 | ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify | |
5162 | ** the database connections for the meaning of "modify" in this paragraph. | |
5163 | ** | |
5164 | ** ^Registering a NULL function disables the callback. | |
5165 | ** | |
5166 | ** ^When the commit hook callback routine returns zero, the [COMMIT] | |
5167 | ** operation is allowed to continue normally. ^If the commit hook | |
5168 | ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. | |
5169 | ** ^The rollback hook is invoked on a rollback that results from a commit | |
5170 | ** hook returning non-zero, just as it would be with any other rollback. | |
5171 | ** | |
5172 | ** ^For the purposes of this API, a transaction is said to have been | |
5783a860 AC |
5173 | ** rolled back if an explicit "ROLLBACK" statement is executed, or |
5174 | ** an error or constraint causes an implicit rollback to occur. | |
08b809f9 | 5175 | ** ^The rollback callback is not invoked if a transaction is |
5783a860 | 5176 | ** automatically rolled back because the database connection is closed. |
5783a860 | 5177 | ** |
08b809f9 | 5178 | ** See also the [sqlite3_update_hook()] interface. |
5783a860 | 5179 | */ |
08b809f9 EM |
5180 | SQLITE_API void *SQLITE_STDCALL sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); |
5181 | SQLITE_API void *SQLITE_STDCALL sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); | |
5783a860 AC |
5182 | |
5183 | /* | |
08b809f9 EM |
5184 | ** CAPI3REF: Data Change Notification Callbacks |
5185 | ** METHOD: sqlite3 | |
5186 | ** | |
5187 | ** ^The sqlite3_update_hook() interface registers a callback function | |
5188 | ** with the [database connection] identified by the first argument | |
5189 | ** to be invoked whenever a row is updated, inserted or deleted in | |
5190 | ** a rowid table. | |
5191 | ** ^Any callback set by a previous call to this function | |
5192 | ** for the same database connection is overridden. | |
5783a860 | 5193 | ** |
08b809f9 EM |
5194 | ** ^The second argument is a pointer to the function to invoke when a |
5195 | ** row is updated, inserted or deleted in a rowid table. | |
5196 | ** ^The first argument to the callback is a copy of the third argument | |
5197 | ** to sqlite3_update_hook(). | |
5198 | ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], | |
5199 | ** or [SQLITE_UPDATE], depending on the operation that caused the callback | |
5200 | ** to be invoked. | |
5201 | ** ^The third and fourth arguments to the callback contain pointers to the | |
5202 | ** database and table name containing the affected row. | |
5203 | ** ^The final callback parameter is the [rowid] of the row. | |
5204 | ** ^In the case of an update, this is the [rowid] after the update takes place. | |
5205 | ** | |
5206 | ** ^(The update hook is not invoked when internal system tables are | |
5207 | ** modified (i.e. sqlite_master and sqlite_sequence).)^ | |
5208 | ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. | |
5209 | ** | |
5210 | ** ^In the current implementation, the update hook | |
5211 | ** is not invoked when duplication rows are deleted because of an | |
5212 | ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook | |
5213 | ** invoked when rows are deleted using the [truncate optimization]. | |
5214 | ** The exceptions defined in this paragraph might change in a future | |
5215 | ** release of SQLite. | |
5216 | ** | |
5217 | ** The update hook implementation must not do anything that will modify | |
5218 | ** the database connection that invoked the update hook. Any actions | |
5219 | ** to modify the database connection must be deferred until after the | |
5220 | ** completion of the [sqlite3_step()] call that triggered the update hook. | |
5221 | ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their | |
5222 | ** database connections for the meaning of "modify" in this paragraph. | |
5223 | ** | |
5224 | ** ^The sqlite3_update_hook(D,C,P) function | |
5225 | ** returns the P argument from the previous call | |
5226 | ** on the same [database connection] D, or NULL for | |
5227 | ** the first call on D. | |
5228 | ** | |
5229 | ** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()] | |
5230 | ** interfaces. | |
5783a860 | 5231 | */ |
08b809f9 EM |
5232 | SQLITE_API void *SQLITE_STDCALL sqlite3_update_hook( |
5233 | sqlite3*, | |
5783a860 AC |
5234 | void(*)(void *,int ,char const *,char const *,sqlite3_int64), |
5235 | void* | |
5236 | ); | |
5237 | ||
5238 | /* | |
08b809f9 | 5239 | ** CAPI3REF: Enable Or Disable Shared Pager Cache |
5783a860 | 5240 | ** |
08b809f9 EM |
5241 | ** ^(This routine enables or disables the sharing of the database cache |
5242 | ** and schema data structures between [database connection | connections] | |
5243 | ** to the same database. Sharing is enabled if the argument is true | |
5244 | ** and disabled if the argument is false.)^ | |
5783a860 | 5245 | ** |
08b809f9 EM |
5246 | ** ^Cache sharing is enabled and disabled for an entire process. |
5247 | ** This is a change as of SQLite version 3.5.0. In prior versions of SQLite, | |
5248 | ** sharing was enabled or disabled for each thread separately. | |
5783a860 | 5249 | ** |
08b809f9 | 5250 | ** ^(The cache sharing mode set by this interface effects all subsequent |
5783a860 AC |
5251 | ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. |
5252 | ** Existing database connections continue use the sharing mode | |
08b809f9 | 5253 | ** that was in effect at the time they were opened.)^ |
5783a860 | 5254 | ** |
08b809f9 EM |
5255 | ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled |
5256 | ** successfully. An [error code] is returned otherwise.)^ | |
5783a860 | 5257 | ** |
08b809f9 | 5258 | ** ^Shared cache is disabled by default. But this might change in |
5783a860 AC |
5259 | ** future releases of SQLite. Applications that care about shared |
5260 | ** cache setting should set it explicitly. | |
5261 | ** | |
08b809f9 EM |
5262 | ** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 |
5263 | ** and will always return SQLITE_MISUSE. On those systems, | |
5264 | ** shared cache mode should be enabled per-database connection via | |
5265 | ** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. | |
5783a860 | 5266 | ** |
08b809f9 EM |
5267 | ** This interface is threadsafe on processors where writing a |
5268 | ** 32-bit integer is atomic. | |
5783a860 | 5269 | ** |
08b809f9 | 5270 | ** See Also: [SQLite Shared-Cache Mode] |
5783a860 | 5271 | */ |
08b809f9 | 5272 | SQLITE_API int SQLITE_STDCALL sqlite3_enable_shared_cache(int); |
5783a860 AC |
5273 | |
5274 | /* | |
08b809f9 EM |
5275 | ** CAPI3REF: Attempt To Free Heap Memory |
5276 | ** | |
5277 | ** ^The sqlite3_release_memory() interface attempts to free N bytes | |
5278 | ** of heap memory by deallocating non-essential memory allocations | |
5279 | ** held by the database library. Memory used to cache database | |
5280 | ** pages to improve performance is an example of non-essential memory. | |
5281 | ** ^sqlite3_release_memory() returns the number of bytes actually freed, | |
5282 | ** which might be more or less than the amount requested. | |
5283 | ** ^The sqlite3_release_memory() routine is a no-op returning zero | |
5284 | ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. | |
5285 | ** | |
5286 | ** See also: [sqlite3_db_release_memory()] | |
5783a860 | 5287 | */ |
08b809f9 | 5288 | SQLITE_API int SQLITE_STDCALL sqlite3_release_memory(int); |
5783a860 AC |
5289 | |
5290 | /* | |
08b809f9 EM |
5291 | ** CAPI3REF: Free Memory Used By A Database Connection |
5292 | ** METHOD: sqlite3 | |
5783a860 | 5293 | ** |
08b809f9 EM |
5294 | ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap |
5295 | ** memory as possible from database connection D. Unlike the | |
5296 | ** [sqlite3_release_memory()] interface, this interface is in effect even | |
5297 | ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is | |
5298 | ** omitted. | |
5783a860 | 5299 | ** |
08b809f9 | 5300 | ** See also: [sqlite3_release_memory()] |
5783a860 | 5301 | */ |
08b809f9 | 5302 | SQLITE_API int SQLITE_STDCALL sqlite3_db_release_memory(sqlite3*); |
5783a860 AC |
5303 | |
5304 | /* | |
08b809f9 EM |
5305 | ** CAPI3REF: Impose A Limit On Heap Size |
5306 | ** | |
5307 | ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the | |
5308 | ** soft limit on the amount of heap memory that may be allocated by SQLite. | |
5309 | ** ^SQLite strives to keep heap memory utilization below the soft heap | |
5310 | ** limit by reducing the number of pages held in the page cache | |
5311 | ** as heap memory usages approaches the limit. | |
5312 | ** ^The soft heap limit is "soft" because even though SQLite strives to stay | |
5313 | ** below the limit, it will exceed the limit rather than generate | |
5314 | ** an [SQLITE_NOMEM] error. In other words, the soft heap limit | |
5315 | ** is advisory only. | |
5316 | ** | |
5317 | ** ^The return value from sqlite3_soft_heap_limit64() is the size of | |
5318 | ** the soft heap limit prior to the call, or negative in the case of an | |
5319 | ** error. ^If the argument N is negative | |
5320 | ** then no change is made to the soft heap limit. Hence, the current | |
5321 | ** size of the soft heap limit can be determined by invoking | |
5322 | ** sqlite3_soft_heap_limit64() with a negative argument. | |
5323 | ** | |
5324 | ** ^If the argument N is zero then the soft heap limit is disabled. | |
5325 | ** | |
5326 | ** ^(The soft heap limit is not enforced in the current implementation | |
5327 | ** if one or more of following conditions are true: | |
5783a860 | 5328 | ** |
08b809f9 EM |
5329 | ** <ul> |
5330 | ** <li> The soft heap limit is set to zero. | |
5331 | ** <li> Memory accounting is disabled using a combination of the | |
5332 | ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and | |
5333 | ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. | |
5334 | ** <li> An alternative page cache implementation is specified using | |
5335 | ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). | |
5336 | ** <li> The page cache allocates from its own memory pool supplied | |
5337 | ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than | |
5338 | ** from the heap. | |
5339 | ** </ul>)^ | |
5340 | ** | |
5341 | ** Beginning with SQLite version 3.7.3, the soft heap limit is enforced | |
5342 | ** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] | |
5343 | ** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], | |
5344 | ** the soft heap limit is enforced on every memory allocation. Without | |
5345 | ** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced | |
5346 | ** when memory is allocated by the page cache. Testing suggests that because | |
5347 | ** the page cache is the predominate memory user in SQLite, most | |
5348 | ** applications will achieve adequate soft heap limit enforcement without | |
5349 | ** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. | |
5350 | ** | |
5351 | ** The circumstances under which SQLite will enforce the soft heap limit may | |
5352 | ** changes in future releases of SQLite. | |
5353 | */ | |
5354 | SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_soft_heap_limit64(sqlite3_int64 N); | |
5355 | ||
5356 | /* | |
5357 | ** CAPI3REF: Deprecated Soft Heap Limit Interface | |
5358 | ** DEPRECATED | |
5783a860 | 5359 | ** |
08b809f9 EM |
5360 | ** This is a deprecated version of the [sqlite3_soft_heap_limit64()] |
5361 | ** interface. This routine is provided for historical compatibility | |
5362 | ** only. All new applications should use the | |
5363 | ** [sqlite3_soft_heap_limit64()] interface rather than this one. | |
5364 | */ | |
5365 | SQLITE_API SQLITE_DEPRECATED void SQLITE_STDCALL sqlite3_soft_heap_limit(int N); | |
5366 | ||
5367 | ||
5368 | /* | |
5369 | ** CAPI3REF: Extract Metadata About A Column Of A Table | |
5370 | ** METHOD: sqlite3 | |
5371 | ** | |
5372 | ** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns | |
5373 | ** information about column C of table T in database D | |
5374 | ** on [database connection] X.)^ ^The sqlite3_table_column_metadata() | |
5375 | ** interface returns SQLITE_OK and fills in the non-NULL pointers in | |
5376 | ** the final five arguments with appropriate values if the specified | |
5377 | ** column exists. ^The sqlite3_table_column_metadata() interface returns | |
5378 | ** SQLITE_ERROR and if the specified column does not exist. | |
5379 | ** ^If the column-name parameter to sqlite3_table_column_metadata() is a | |
5380 | ** NULL pointer, then this routine simply checks for the existance of the | |
5381 | ** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it | |
5382 | ** does not. | |
5383 | ** | |
5384 | ** ^The column is identified by the second, third and fourth parameters to | |
5385 | ** this function. ^(The second parameter is either the name of the database | |
5386 | ** (i.e. "main", "temp", or an attached database) containing the specified | |
5387 | ** table or NULL.)^ ^If it is NULL, then all attached databases are searched | |
5388 | ** for the table using the same algorithm used by the database engine to | |
5783a860 AC |
5389 | ** resolve unqualified table references. |
5390 | ** | |
08b809f9 EM |
5391 | ** ^The third and fourth parameters to this function are the table and column |
5392 | ** name of the desired column, respectively. | |
5783a860 | 5393 | ** |
08b809f9 EM |
5394 | ** ^Metadata is returned by writing to the memory locations passed as the 5th |
5395 | ** and subsequent parameters to this function. ^Any of these arguments may be | |
5396 | ** NULL, in which case the corresponding element of metadata is omitted. | |
5783a860 | 5397 | ** |
08b809f9 EM |
5398 | ** ^(<blockquote> |
5399 | ** <table border="1"> | |
5400 | ** <tr><th> Parameter <th> Output<br>Type <th> Description | |
5783a860 | 5401 | ** |
08b809f9 EM |
5402 | ** <tr><td> 5th <td> const char* <td> Data type |
5403 | ** <tr><td> 6th <td> const char* <td> Name of default collation sequence | |
5404 | ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint | |
5405 | ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY | |
5406 | ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] | |
5407 | ** </table> | |
5408 | ** </blockquote>)^ | |
5783a860 | 5409 | ** |
08b809f9 EM |
5410 | ** ^The memory pointed to by the character pointers returned for the |
5411 | ** declaration type and collation sequence is valid until the next | |
5412 | ** call to any SQLite API function. | |
5783a860 | 5413 | ** |
08b809f9 | 5414 | ** ^If the specified table is actually a view, an [error code] is returned. |
5783a860 | 5415 | ** |
08b809f9 EM |
5416 | ** ^If the specified column is "rowid", "oid" or "_rowid_" and the table |
5417 | ** is not a [WITHOUT ROWID] table and an | |
5418 | ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output | |
5419 | ** parameters are set for the explicitly declared column. ^(If there is no | |
5420 | ** [INTEGER PRIMARY KEY] column, then the outputs | |
5421 | ** for the [rowid] are set as follows: | |
5783a860 AC |
5422 | ** |
5423 | ** <pre> | |
5424 | ** data type: "INTEGER" | |
5425 | ** collation sequence: "BINARY" | |
5426 | ** not null: 0 | |
5427 | ** primary key: 1 | |
5428 | ** auto increment: 0 | |
08b809f9 | 5429 | ** </pre>)^ |
5783a860 | 5430 | ** |
08b809f9 EM |
5431 | ** ^This function causes all database schemas to be read from disk and |
5432 | ** parsed, if that has not already been done, and returns an error if | |
5433 | ** any errors are encountered while loading the schema. | |
5783a860 | 5434 | */ |
08b809f9 | 5435 | SQLITE_API int SQLITE_STDCALL sqlite3_table_column_metadata( |
5783a860 AC |
5436 | sqlite3 *db, /* Connection handle */ |
5437 | const char *zDbName, /* Database name or NULL */ | |
5438 | const char *zTableName, /* Table name */ | |
5439 | const char *zColumnName, /* Column name */ | |
5440 | char const **pzDataType, /* OUTPUT: Declared data type */ | |
5441 | char const **pzCollSeq, /* OUTPUT: Collation sequence name */ | |
5442 | int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ | |
5443 | int *pPrimaryKey, /* OUTPUT: True if column part of PK */ | |
5444 | int *pAutoinc /* OUTPUT: True if column is auto-increment */ | |
5445 | ); | |
5446 | ||
5447 | /* | |
08b809f9 EM |
5448 | ** CAPI3REF: Load An Extension |
5449 | ** METHOD: sqlite3 | |
5450 | ** | |
5451 | ** ^This interface loads an SQLite extension library from the named file. | |
5452 | ** | |
5453 | ** ^The sqlite3_load_extension() interface attempts to load an | |
5454 | ** [SQLite extension] library contained in the file zFile. If | |
5455 | ** the file cannot be loaded directly, attempts are made to load | |
5456 | ** with various operating-system specific extensions added. | |
5457 | ** So for example, if "samplelib" cannot be loaded, then names like | |
5458 | ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might | |
5459 | ** be tried also. | |
5460 | ** | |
5461 | ** ^The entry point is zProc. | |
5462 | ** ^(zProc may be 0, in which case SQLite will try to come up with an | |
5463 | ** entry point name on its own. It first tries "sqlite3_extension_init". | |
5464 | ** If that does not work, it constructs a name "sqlite3_X_init" where the | |
5465 | ** X is consists of the lower-case equivalent of all ASCII alphabetic | |
5466 | ** characters in the filename from the last "/" to the first following | |
5467 | ** "." and omitting any initial "lib".)^ | |
5468 | ** ^The sqlite3_load_extension() interface returns | |
5469 | ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. | |
5470 | ** ^If an error occurs and pzErrMsg is not 0, then the | |
5471 | ** [sqlite3_load_extension()] interface shall attempt to | |
5472 | ** fill *pzErrMsg with error message text stored in memory | |
5473 | ** obtained from [sqlite3_malloc()]. The calling function | |
5474 | ** should free this memory by calling [sqlite3_free()]. | |
5475 | ** | |
5476 | ** ^Extension loading must be enabled using | |
5477 | ** [sqlite3_enable_load_extension()] prior to calling this API, | |
5478 | ** otherwise an error will be returned. | |
5479 | ** | |
5480 | ** See also the [load_extension() SQL function]. | |
5783a860 | 5481 | */ |
08b809f9 | 5482 | SQLITE_API int SQLITE_STDCALL sqlite3_load_extension( |
5783a860 AC |
5483 | sqlite3 *db, /* Load the extension into this database connection */ |
5484 | const char *zFile, /* Name of the shared library containing extension */ | |
5485 | const char *zProc, /* Entry point. Derived from zFile if 0 */ | |
5486 | char **pzErrMsg /* Put error message here if not 0 */ | |
5487 | ); | |
5488 | ||
5489 | /* | |
08b809f9 EM |
5490 | ** CAPI3REF: Enable Or Disable Extension Loading |
5491 | ** METHOD: sqlite3 | |
5492 | ** | |
5493 | ** ^So as not to open security holes in older applications that are | |
5494 | ** unprepared to deal with [extension loading], and as a means of disabling | |
5495 | ** [extension loading] while evaluating user-entered SQL, the following API | |
5496 | ** is provided to turn the [sqlite3_load_extension()] mechanism on and off. | |
5497 | ** | |
5498 | ** ^Extension loading is off by default. | |
5499 | ** ^Call the sqlite3_enable_load_extension() routine with onoff==1 | |
5500 | ** to turn extension loading on and call it with onoff==0 to turn | |
5501 | ** it back off again. | |
5783a860 | 5502 | */ |
08b809f9 | 5503 | SQLITE_API int SQLITE_STDCALL sqlite3_enable_load_extension(sqlite3 *db, int onoff); |
5783a860 AC |
5504 | |
5505 | /* | |
08b809f9 | 5506 | ** CAPI3REF: Automatically Load Statically Linked Extensions |
5783a860 | 5507 | ** |
08b809f9 EM |
5508 | ** ^This interface causes the xEntryPoint() function to be invoked for |
5509 | ** each new [database connection] that is created. The idea here is that | |
5510 | ** xEntryPoint() is the entry point for a statically linked [SQLite extension] | |
5511 | ** that is to be automatically loaded into all new database connections. | |
5783a860 | 5512 | ** |
08b809f9 EM |
5513 | ** ^(Even though the function prototype shows that xEntryPoint() takes |
5514 | ** no arguments and returns void, SQLite invokes xEntryPoint() with three | |
5515 | ** arguments and expects and integer result as if the signature of the | |
5516 | ** entry point where as follows: | |
5783a860 | 5517 | ** |
08b809f9 EM |
5518 | ** <blockquote><pre> |
5519 | ** int xEntryPoint( | |
5520 | ** sqlite3 *db, | |
5521 | ** const char **pzErrMsg, | |
5522 | ** const struct sqlite3_api_routines *pThunk | |
5523 | ** ); | |
5524 | ** </pre></blockquote>)^ | |
5525 | ** | |
5526 | ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg | |
5527 | ** point to an appropriate error message (obtained from [sqlite3_mprintf()]) | |
5528 | ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg | |
5529 | ** is NULL before calling the xEntryPoint(). ^SQLite will invoke | |
5530 | ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any | |
5531 | ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], | |
5532 | ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. | |
5533 | ** | |
5534 | ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already | |
5535 | ** on the list of automatic extensions is a harmless no-op. ^No entry point | |
5536 | ** will be called more than once for each database connection that is opened. | |
5537 | ** | |
5538 | ** See also: [sqlite3_reset_auto_extension()] | |
5539 | ** and [sqlite3_cancel_auto_extension()] | |
5783a860 | 5540 | */ |
08b809f9 | 5541 | SQLITE_API int SQLITE_STDCALL sqlite3_auto_extension(void (*xEntryPoint)(void)); |
5783a860 | 5542 | |
08b809f9 EM |
5543 | /* |
5544 | ** CAPI3REF: Cancel Automatic Extension Loading | |
5545 | ** | |
5546 | ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the | |
5547 | ** initialization routine X that was registered using a prior call to | |
5548 | ** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] | |
5549 | ** routine returns 1 if initialization routine X was successfully | |
5550 | ** unregistered and it returns 0 if X was not on the list of initialization | |
5551 | ** routines. | |
5552 | */ | |
5553 | SQLITE_API int SQLITE_STDCALL sqlite3_cancel_auto_extension(void (*xEntryPoint)(void)); | |
5783a860 AC |
5554 | |
5555 | /* | |
08b809f9 | 5556 | ** CAPI3REF: Reset Automatic Extension Loading |
5783a860 | 5557 | ** |
08b809f9 EM |
5558 | ** ^This interface disables all automatic extensions previously |
5559 | ** registered using [sqlite3_auto_extension()]. | |
5783a860 | 5560 | */ |
08b809f9 | 5561 | SQLITE_API void SQLITE_STDCALL sqlite3_reset_auto_extension(void); |
5783a860 AC |
5562 | |
5563 | /* | |
5783a860 AC |
5564 | ** The interface to the virtual-table mechanism 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 | ** | |
08b809f9 | 5568 | ** When the virtual-table mechanism stabilizes, we will declare the |
5783a860 AC |
5569 | ** interface fixed, support it indefinitely, and remove this comment. |
5570 | */ | |
5571 | ||
5572 | /* | |
5573 | ** Structures used by the virtual table interface | |
5574 | */ | |
5575 | typedef struct sqlite3_vtab sqlite3_vtab; | |
5576 | typedef struct sqlite3_index_info sqlite3_index_info; | |
5577 | typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; | |
5578 | typedef struct sqlite3_module sqlite3_module; | |
5579 | ||
5580 | /* | |
08b809f9 EM |
5581 | ** CAPI3REF: Virtual Table Object |
5582 | ** KEYWORDS: sqlite3_module {virtual table module} | |
5583 | ** | |
5584 | ** This structure, sometimes called a "virtual table module", | |
5585 | ** defines the implementation of a [virtual tables]. | |
5586 | ** This structure consists mostly of methods for the module. | |
5587 | ** | |
5588 | ** ^A virtual table module is created by filling in a persistent | |
5589 | ** instance of this structure and passing a pointer to that instance | |
5590 | ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. | |
5591 | ** ^The registration remains valid until it is replaced by a different | |
5592 | ** module or until the [database connection] closes. The content | |
5593 | ** of this structure must not change while it is registered with | |
5594 | ** any database connection. | |
5783a860 AC |
5595 | */ |
5596 | struct sqlite3_module { | |
5597 | int iVersion; | |
5598 | int (*xCreate)(sqlite3*, void *pAux, | |
5599 | int argc, const char *const*argv, | |
5600 | sqlite3_vtab **ppVTab, char**); | |
5601 | int (*xConnect)(sqlite3*, void *pAux, | |
5602 | int argc, const char *const*argv, | |
5603 | sqlite3_vtab **ppVTab, char**); | |
5604 | int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); | |
5605 | int (*xDisconnect)(sqlite3_vtab *pVTab); | |
5606 | int (*xDestroy)(sqlite3_vtab *pVTab); | |
5607 | int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); | |
5608 | int (*xClose)(sqlite3_vtab_cursor*); | |
5609 | int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, | |
5610 | int argc, sqlite3_value **argv); | |
5611 | int (*xNext)(sqlite3_vtab_cursor*); | |
5612 | int (*xEof)(sqlite3_vtab_cursor*); | |
5613 | int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); | |
5614 | int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); | |
5615 | int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); | |
5616 | int (*xBegin)(sqlite3_vtab *pVTab); | |
5617 | int (*xSync)(sqlite3_vtab *pVTab); | |
5618 | int (*xCommit)(sqlite3_vtab *pVTab); | |
5619 | int (*xRollback)(sqlite3_vtab *pVTab); | |
5620 | int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, | |
5621 | void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), | |
5622 | void **ppArg); | |
5783a860 | 5623 | int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); |
08b809f9 EM |
5624 | /* The methods above are in version 1 of the sqlite_module object. Those |
5625 | ** below are for version 2 and greater. */ | |
5626 | int (*xSavepoint)(sqlite3_vtab *pVTab, int); | |
5627 | int (*xRelease)(sqlite3_vtab *pVTab, int); | |
5628 | int (*xRollbackTo)(sqlite3_vtab *pVTab, int); | |
5783a860 AC |
5629 | }; |
5630 | ||
5631 | /* | |
08b809f9 | 5632 | ** CAPI3REF: Virtual Table Indexing Information |
5783a860 AC |
5633 | ** KEYWORDS: sqlite3_index_info |
5634 | ** | |
08b809f9 EM |
5635 | ** The sqlite3_index_info structure and its substructures is used as part |
5636 | ** of the [virtual table] interface to | |
5637 | ** pass information into and receive the reply from the [xBestIndex] | |
5638 | ** method of a [virtual table module]. The fields under **Inputs** are the | |
5783a860 AC |
5639 | ** inputs to xBestIndex and are read-only. xBestIndex inserts its |
5640 | ** results into the **Outputs** fields. | |
5641 | ** | |
08b809f9 | 5642 | ** ^(The aConstraint[] array records WHERE clause constraints of the form: |
5783a860 | 5643 | ** |
08b809f9 | 5644 | ** <blockquote>column OP expr</blockquote> |
5783a860 | 5645 | ** |
08b809f9 EM |
5646 | ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is |
5647 | ** stored in aConstraint[].op using one of the | |
5648 | ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ | |
5649 | ** ^(The index of the column is stored in | |
5650 | ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the | |
5783a860 | 5651 | ** expr on the right-hand side can be evaluated (and thus the constraint |
08b809f9 | 5652 | ** is usable) and false if it cannot.)^ |
5783a860 | 5653 | ** |
08b809f9 | 5654 | ** ^The optimizer automatically inverts terms of the form "expr OP column" |
5783a860 AC |
5655 | ** and makes other simplifications to the WHERE clause in an attempt to |
5656 | ** get as many WHERE clause terms into the form shown above as possible. | |
08b809f9 EM |
5657 | ** ^The aConstraint[] array only reports WHERE clause terms that are |
5658 | ** relevant to the particular virtual table being queried. | |
5659 | ** | |
5660 | ** ^Information about the ORDER BY clause is stored in aOrderBy[]. | |
5661 | ** ^Each term of aOrderBy records a column of the ORDER BY clause. | |
5662 | ** | |
5663 | ** The colUsed field indicates which columns of the virtual table may be | |
5664 | ** required by the current scan. Virtual table columns are numbered from | |
5665 | ** zero in the order in which they appear within the CREATE TABLE statement | |
5666 | ** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), | |
5667 | ** the corresponding bit is set within the colUsed mask if the column may be | |
5668 | ** required by SQLite. If the table has at least 64 columns and any column | |
5669 | ** to the right of the first 63 is required, then bit 63 of colUsed is also | |
5670 | ** set. In other words, column iCol may be required if the expression | |
5671 | ** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to | |
5672 | ** non-zero. | |
5673 | ** | |
5674 | ** The [xBestIndex] method must fill aConstraintUsage[] with information | |
5675 | ** about what parameters to pass to xFilter. ^If argvIndex>0 then | |
5783a860 | 5676 | ** the right-hand side of the corresponding aConstraint[] is evaluated |
08b809f9 | 5677 | ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit |
5783a860 | 5678 | ** is true, then the constraint is assumed to be fully handled by the |
08b809f9 | 5679 | ** virtual table and is not checked again by SQLite.)^ |
5783a860 | 5680 | ** |
08b809f9 EM |
5681 | ** ^The idxNum and idxPtr values are recorded and passed into the |
5682 | ** [xFilter] method. | |
5683 | ** ^[sqlite3_free()] is used to free idxPtr if and only if | |
5684 | ** needToFreeIdxPtr is true. | |
5783a860 | 5685 | ** |
08b809f9 | 5686 | ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in |
5783a860 AC |
5687 | ** the correct order to satisfy the ORDER BY clause so that no separate |
5688 | ** sorting step is required. | |
5689 | ** | |
08b809f9 EM |
5690 | ** ^The estimatedCost value is an estimate of the cost of a particular |
5691 | ** strategy. A cost of N indicates that the cost of the strategy is similar | |
5692 | ** to a linear scan of an SQLite table with N rows. A cost of log(N) | |
5693 | ** indicates that the expense of the operation is similar to that of a | |
5694 | ** binary search on a unique indexed field of an SQLite table with N rows. | |
5695 | ** | |
5696 | ** ^The estimatedRows value is an estimate of the number of rows that | |
5697 | ** will be returned by the strategy. | |
5698 | ** | |
5699 | ** The xBestIndex method may optionally populate the idxFlags field with a | |
5700 | ** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - | |
5701 | ** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite | |
5702 | ** assumes that the strategy may visit at most one row. | |
5703 | ** | |
5704 | ** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then | |
5705 | ** SQLite also assumes that if a call to the xUpdate() method is made as | |
5706 | ** part of the same statement to delete or update a virtual table row and the | |
5707 | ** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback | |
5708 | ** any database changes. In other words, if the xUpdate() returns | |
5709 | ** SQLITE_CONSTRAINT, the database contents must be exactly as they were | |
5710 | ** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not | |
5711 | ** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by | |
5712 | ** the xUpdate method are automatically rolled back by SQLite. | |
5713 | ** | |
5714 | ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info | |
5715 | ** structure for SQLite version 3.8.2. If a virtual table extension is | |
5716 | ** used with an SQLite version earlier than 3.8.2, the results of attempting | |
5717 | ** to read or write the estimatedRows field are undefined (but are likely | |
5718 | ** to included crashing the application). The estimatedRows field should | |
5719 | ** therefore only be used if [sqlite3_libversion_number()] returns a | |
5720 | ** value greater than or equal to 3008002. Similarly, the idxFlags field | |
5721 | ** was added for version 3.9.0. It may therefore only be used if | |
5722 | ** sqlite3_libversion_number() returns a value greater than or equal to | |
5723 | ** 3009000. | |
5783a860 AC |
5724 | */ |
5725 | struct sqlite3_index_info { | |
5726 | /* Inputs */ | |
5727 | int nConstraint; /* Number of entries in aConstraint */ | |
5728 | struct sqlite3_index_constraint { | |
08b809f9 | 5729 | int iColumn; /* Column constrained. -1 for ROWID */ |
5783a860 AC |
5730 | unsigned char op; /* Constraint operator */ |
5731 | unsigned char usable; /* True if this constraint is usable */ | |
5732 | int iTermOffset; /* Used internally - xBestIndex should ignore */ | |
5733 | } *aConstraint; /* Table of WHERE clause constraints */ | |
5734 | int nOrderBy; /* Number of terms in the ORDER BY clause */ | |
5735 | struct sqlite3_index_orderby { | |
5736 | int iColumn; /* Column number */ | |
5737 | unsigned char desc; /* True for DESC. False for ASC. */ | |
5738 | } *aOrderBy; /* The ORDER BY clause */ | |
5783a860 AC |
5739 | /* Outputs */ |
5740 | struct sqlite3_index_constraint_usage { | |
5741 | int argvIndex; /* if >0, constraint is part of argv to xFilter */ | |
5742 | unsigned char omit; /* Do not code a test for this constraint */ | |
5743 | } *aConstraintUsage; | |
5744 | int idxNum; /* Number used to identify the index */ | |
5745 | char *idxStr; /* String, possibly obtained from sqlite3_malloc */ | |
5746 | int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ | |
5747 | int orderByConsumed; /* True if output is already ordered */ | |
08b809f9 EM |
5748 | double estimatedCost; /* Estimated cost of using this index */ |
5749 | /* Fields below are only available in SQLite 3.8.2 and later */ | |
5750 | sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ | |
5751 | /* Fields below are only available in SQLite 3.9.0 and later */ | |
5752 | int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ | |
5753 | /* Fields below are only available in SQLite 3.10.0 and later */ | |
5754 | sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ | |
5783a860 | 5755 | }; |
5783a860 AC |
5756 | |
5757 | /* | |
08b809f9 | 5758 | ** CAPI3REF: Virtual Table Scan Flags |
5783a860 | 5759 | */ |
08b809f9 | 5760 | #define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ |
5783a860 AC |
5761 | |
5762 | /* | |
08b809f9 | 5763 | ** CAPI3REF: Virtual Table Constraint Operator Codes |
5783a860 | 5764 | ** |
08b809f9 EM |
5765 | ** These macros defined the allowed values for the |
5766 | ** [sqlite3_index_info].aConstraint[].op field. Each value represents | |
5767 | ** an operator that is part of a constraint term in the wHERE clause of | |
5768 | ** a query that uses a [virtual table]. | |
5769 | */ | |
5770 | #define SQLITE_INDEX_CONSTRAINT_EQ 2 | |
5771 | #define SQLITE_INDEX_CONSTRAINT_GT 4 | |
5772 | #define SQLITE_INDEX_CONSTRAINT_LE 8 | |
5773 | #define SQLITE_INDEX_CONSTRAINT_LT 16 | |
5774 | #define SQLITE_INDEX_CONSTRAINT_GE 32 | |
5775 | #define SQLITE_INDEX_CONSTRAINT_MATCH 64 | |
5776 | #define SQLITE_INDEX_CONSTRAINT_LIKE 65 | |
5777 | #define SQLITE_INDEX_CONSTRAINT_GLOB 66 | |
5778 | #define SQLITE_INDEX_CONSTRAINT_REGEXP 67 | |
5779 | ||
5780 | /* | |
5781 | ** CAPI3REF: Register A Virtual Table Implementation | |
5782 | ** METHOD: sqlite3 | |
5783 | ** | |
5784 | ** ^These routines are used to register a new [virtual table module] name. | |
5785 | ** ^Module names must be registered before | |
5786 | ** creating a new [virtual table] using the module and before using a | |
5787 | ** preexisting [virtual table] for the module. | |
5788 | ** | |
5789 | ** ^The module name is registered on the [database connection] specified | |
5790 | ** by the first parameter. ^The name of the module is given by the | |
5791 | ** second parameter. ^The third parameter is a pointer to | |
5792 | ** the implementation of the [virtual table module]. ^The fourth | |
5793 | ** parameter is an arbitrary client data pointer that is passed through | |
5794 | ** into the [xCreate] and [xConnect] methods of the virtual table module | |
5795 | ** when a new virtual table is be being created or reinitialized. | |
5796 | ** | |
5797 | ** ^The sqlite3_create_module_v2() interface has a fifth parameter which | |
5798 | ** is a pointer to a destructor for the pClientData. ^SQLite will | |
5799 | ** invoke the destructor function (if it is not NULL) when SQLite | |
5800 | ** no longer needs the pClientData pointer. ^The destructor will also | |
5801 | ** be invoked if the call to sqlite3_create_module_v2() fails. | |
5802 | ** ^The sqlite3_create_module() | |
5803 | ** interface is equivalent to sqlite3_create_module_v2() with a NULL | |
5804 | ** destructor. | |
5783a860 | 5805 | */ |
08b809f9 EM |
5806 | SQLITE_API int SQLITE_STDCALL sqlite3_create_module( |
5807 | sqlite3 *db, /* SQLite connection to register module with */ | |
5808 | const char *zName, /* Name of the module */ | |
5809 | const sqlite3_module *p, /* Methods for the module */ | |
5810 | void *pClientData /* Client data for xCreate/xConnect */ | |
5811 | ); | |
5812 | SQLITE_API int SQLITE_STDCALL sqlite3_create_module_v2( | |
5783a860 AC |
5813 | sqlite3 *db, /* SQLite connection to register module with */ |
5814 | const char *zName, /* Name of the module */ | |
08b809f9 EM |
5815 | const sqlite3_module *p, /* Methods for the module */ |
5816 | void *pClientData, /* Client data for xCreate/xConnect */ | |
5783a860 AC |
5817 | void(*xDestroy)(void*) /* Module destructor function */ |
5818 | ); | |
5819 | ||
5820 | /* | |
08b809f9 | 5821 | ** CAPI3REF: Virtual Table Instance Object |
5783a860 AC |
5822 | ** KEYWORDS: sqlite3_vtab |
5823 | ** | |
08b809f9 EM |
5824 | ** Every [virtual table module] implementation uses a subclass |
5825 | ** of this object to describe a particular instance | |
5826 | ** of the [virtual table]. Each subclass will | |
5827 | ** be tailored to the specific needs of the module implementation. | |
5828 | ** The purpose of this superclass is to define certain fields that are | |
5829 | ** common to all module implementations. | |
5830 | ** | |
5831 | ** ^Virtual tables methods can set an error message by assigning a | |
5832 | ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should | |
5833 | ** take care that any prior string is freed by a call to [sqlite3_free()] | |
5834 | ** prior to assigning a new string to zErrMsg. ^After the error message | |
5783a860 | 5835 | ** is delivered up to the client application, the string will be automatically |
08b809f9 | 5836 | ** freed by sqlite3_free() and the zErrMsg field will be zeroed. |
5783a860 AC |
5837 | */ |
5838 | struct sqlite3_vtab { | |
5839 | const sqlite3_module *pModule; /* The module for this virtual table */ | |
08b809f9 | 5840 | int nRef; /* Number of open cursors */ |
5783a860 AC |
5841 | char *zErrMsg; /* Error message from sqlite3_mprintf() */ |
5842 | /* Virtual table implementations will typically add additional fields */ | |
5843 | }; | |
5844 | ||
5845 | /* | |
08b809f9 EM |
5846 | ** CAPI3REF: Virtual Table Cursor Object |
5847 | ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} | |
5783a860 | 5848 | ** |
08b809f9 EM |
5849 | ** Every [virtual table module] implementation uses a subclass of the |
5850 | ** following structure to describe cursors that point into the | |
5851 | ** [virtual table] and are used | |
5783a860 | 5852 | ** to loop through the virtual table. Cursors are created using the |
08b809f9 EM |
5853 | ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed |
5854 | ** by the [sqlite3_module.xClose | xClose] method. Cursors are used | |
5855 | ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods | |
5856 | ** of the module. Each module implementation will define | |
5783a860 AC |
5857 | ** the content of a cursor structure to suit its own needs. |
5858 | ** | |
5859 | ** This superclass exists in order to define fields of the cursor that | |
5860 | ** are common to all implementations. | |
5861 | */ | |
5862 | struct sqlite3_vtab_cursor { | |
5863 | sqlite3_vtab *pVtab; /* Virtual table of this cursor */ | |
5864 | /* Virtual table implementations will typically add additional fields */ | |
5865 | }; | |
5866 | ||
5867 | /* | |
08b809f9 | 5868 | ** CAPI3REF: Declare The Schema Of A Virtual Table |
5783a860 | 5869 | ** |
08b809f9 EM |
5870 | ** ^The [xCreate] and [xConnect] methods of a |
5871 | ** [virtual table module] call this interface | |
5783a860 AC |
5872 | ** to declare the format (the names and datatypes of the columns) of |
5873 | ** the virtual tables they implement. | |
5874 | */ | |
08b809f9 | 5875 | SQLITE_API int SQLITE_STDCALL sqlite3_declare_vtab(sqlite3*, const char *zSQL); |
5783a860 AC |
5876 | |
5877 | /* | |
08b809f9 EM |
5878 | ** CAPI3REF: Overload A Function For A Virtual Table |
5879 | ** METHOD: sqlite3 | |
5783a860 | 5880 | ** |
08b809f9 EM |
5881 | ** ^(Virtual tables can provide alternative implementations of functions |
5882 | ** using the [xFindFunction] method of the [virtual table module]. | |
5883 | ** But global versions of those functions | |
5884 | ** must exist in order to be overloaded.)^ | |
5783a860 | 5885 | ** |
08b809f9 | 5886 | ** ^(This API makes sure a global version of a function with a particular |
5783a860 | 5887 | ** name and number of parameters exists. If no such function exists |
08b809f9 | 5888 | ** before this API is called, a new function is created.)^ ^The implementation |
5783a860 AC |
5889 | ** of the new function always causes an exception to be thrown. So |
5890 | ** the new function is not good for anything by itself. Its only | |
08b809f9 EM |
5891 | ** purpose is to be a placeholder function that can be overloaded |
5892 | ** by a [virtual table]. | |
5783a860 | 5893 | */ |
08b809f9 | 5894 | SQLITE_API int SQLITE_STDCALL sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); |
5783a860 AC |
5895 | |
5896 | /* | |
5897 | ** The interface to the virtual-table mechanism defined above (back up | |
5898 | ** to a comment remarkably similar to this one) is currently considered | |
5899 | ** to be experimental. The interface might change in incompatible ways. | |
5900 | ** If this is a problem for you, do not use the interface at this time. | |
5901 | ** | |
5902 | ** When the virtual-table mechanism stabilizes, we will declare the | |
5903 | ** interface fixed, support it indefinitely, and remove this comment. | |
5783a860 AC |
5904 | */ |
5905 | ||
5906 | /* | |
08b809f9 EM |
5907 | ** CAPI3REF: A Handle To An Open BLOB |
5908 | ** KEYWORDS: {BLOB handle} {BLOB handles} | |
5783a860 AC |
5909 | ** |
5910 | ** An instance of this object represents an open BLOB on which | |
08b809f9 EM |
5911 | ** [sqlite3_blob_open | incremental BLOB I/O] can be performed. |
5912 | ** ^Objects of this type are created by [sqlite3_blob_open()] | |
5913 | ** and destroyed by [sqlite3_blob_close()]. | |
5914 | ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces | |
5915 | ** can be used to read or write small subsections of the BLOB. | |
5916 | ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. | |
5783a860 AC |
5917 | */ |
5918 | typedef struct sqlite3_blob sqlite3_blob; | |
5919 | ||
5920 | /* | |
08b809f9 EM |
5921 | ** CAPI3REF: Open A BLOB For Incremental I/O |
5922 | ** METHOD: sqlite3 | |
5923 | ** CONSTRUCTOR: sqlite3_blob | |
5783a860 | 5924 | ** |
08b809f9 | 5925 | ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located |
5783a860 | 5926 | ** in row iRow, column zColumn, table zTable in database zDb; |
08b809f9 | 5927 | ** in other words, the same BLOB that would be selected by: |
5783a860 AC |
5928 | ** |
5929 | ** <pre> | |
08b809f9 EM |
5930 | ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; |
5931 | ** </pre>)^ | |
5932 | ** | |
5933 | ** ^(Parameter zDb is not the filename that contains the database, but | |
5934 | ** rather the symbolic name of the database. For attached databases, this is | |
5935 | ** the name that appears after the AS keyword in the [ATTACH] statement. | |
5936 | ** For the main database file, the database name is "main". For TEMP | |
5937 | ** tables, the database name is "temp".)^ | |
5938 | ** | |
5939 | ** ^If the flags parameter is non-zero, then the BLOB is opened for read | |
5940 | ** and write access. ^If the flags parameter is zero, the BLOB is opened for | |
5941 | ** read-only access. | |
5942 | ** | |
5943 | ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored | |
5944 | ** in *ppBlob. Otherwise an [error code] is returned and, unless the error | |
5945 | ** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided | |
5946 | ** the API is not misused, it is always safe to call [sqlite3_blob_close()] | |
5947 | ** on *ppBlob after this function it returns. | |
5948 | ** | |
5949 | ** This function fails with SQLITE_ERROR if any of the following are true: | |
5950 | ** <ul> | |
5951 | ** <li> ^(Database zDb does not exist)^, | |
5952 | ** <li> ^(Table zTable does not exist within database zDb)^, | |
5953 | ** <li> ^(Table zTable is a WITHOUT ROWID table)^, | |
5954 | ** <li> ^(Column zColumn does not exist)^, | |
5955 | ** <li> ^(Row iRow is not present in the table)^, | |
5956 | ** <li> ^(The specified column of row iRow contains a value that is not | |
5957 | ** a TEXT or BLOB value)^, | |
5958 | ** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE | |
5959 | ** constraint and the blob is being opened for read/write access)^, | |
5960 | ** <li> ^([foreign key constraints | Foreign key constraints] are enabled, | |
5961 | ** column zColumn is part of a [child key] definition and the blob is | |
5962 | ** being opened for read/write access)^. | |
5963 | ** </ul> | |
5783a860 | 5964 | ** |
08b809f9 EM |
5965 | ** ^Unless it returns SQLITE_MISUSE, this function sets the |
5966 | ** [database connection] error code and message accessible via | |
5967 | ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. | |
5968 | ** | |
5969 | ** | |
5970 | ** ^(If the row that a BLOB handle points to is modified by an | |
5971 | ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects | |
5972 | ** then the BLOB handle is marked as "expired". | |
5973 | ** This is true if any column of the row is changed, even a column | |
5974 | ** other than the one the BLOB handle is open on.)^ | |
5975 | ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for | |
5976 | ** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. | |
5977 | ** ^(Changes written into a BLOB prior to the BLOB expiring are not | |
5978 | ** rolled back by the expiration of the BLOB. Such changes will eventually | |
5979 | ** commit if the transaction continues to completion.)^ | |
5980 | ** | |
5981 | ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of | |
5982 | ** the opened blob. ^The size of a blob may not be changed by this | |
5983 | ** interface. Use the [UPDATE] SQL command to change the size of a | |
5984 | ** blob. | |
5985 | ** | |
5986 | ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces | |
5987 | ** and the built-in [zeroblob] SQL function may be used to create a | |
5988 | ** zero-filled blob to read or write using the incremental-blob interface. | |
5989 | ** | |
5990 | ** To avoid a resource leak, every open [BLOB handle] should eventually | |
5991 | ** be released by a call to [sqlite3_blob_close()]. | |
5783a860 | 5992 | */ |
08b809f9 | 5993 | SQLITE_API int SQLITE_STDCALL sqlite3_blob_open( |
5783a860 AC |
5994 | sqlite3*, |
5995 | const char *zDb, | |
5996 | const char *zTable, | |
5997 | const char *zColumn, | |
5998 | sqlite3_int64 iRow, | |
5999 | int flags, | |
6000 | sqlite3_blob **ppBlob | |
6001 | ); | |
6002 | ||
6003 | /* | |
08b809f9 EM |
6004 | ** CAPI3REF: Move a BLOB Handle to a New Row |
6005 | ** METHOD: sqlite3_blob | |
6006 | ** | |
6007 | ** ^This function is used to move an existing blob handle so that it points | |
6008 | ** to a different row of the same database table. ^The new row is identified | |
6009 | ** by the rowid value passed as the second argument. Only the row can be | |
6010 | ** changed. ^The database, table and column on which the blob handle is open | |
6011 | ** remain the same. Moving an existing blob handle to a new row can be | |
6012 | ** faster than closing the existing handle and opening a new one. | |
6013 | ** | |
6014 | ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - | |
6015 | ** it must exist and there must be either a blob or text value stored in | |
6016 | ** the nominated column.)^ ^If the new row is not present in the table, or if | |
6017 | ** it does not contain a blob or text value, or if another error occurs, an | |
6018 | ** SQLite error code is returned and the blob handle is considered aborted. | |
6019 | ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or | |
6020 | ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return | |
6021 | ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle | |
6022 | ** always returns zero. | |
6023 | ** | |
6024 | ** ^This function sets the database handle error code and message. | |
5783a860 | 6025 | */ |
08b809f9 | 6026 | SQLITE_API int SQLITE_STDCALL sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); |
5783a860 AC |
6027 | |
6028 | /* | |
08b809f9 EM |
6029 | ** CAPI3REF: Close A BLOB Handle |
6030 | ** DESTRUCTOR: sqlite3_blob | |
6031 | ** | |
6032 | ** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed | |
6033 | ** unconditionally. Even if this routine returns an error code, the | |
6034 | ** handle is still closed.)^ | |
6035 | ** | |
6036 | ** ^If the blob handle being closed was opened for read-write access, and if | |
6037 | ** the database is in auto-commit mode and there are no other open read-write | |
6038 | ** blob handles or active write statements, the current transaction is | |
6039 | ** committed. ^If an error occurs while committing the transaction, an error | |
6040 | ** code is returned and the transaction rolled back. | |
6041 | ** | |
6042 | ** Calling this function with an argument that is not a NULL pointer or an | |
6043 | ** open blob handle results in undefined behaviour. ^Calling this routine | |
6044 | ** with a null pointer (such as would be returned by a failed call to | |
6045 | ** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function | |
6046 | ** is passed a valid open blob handle, the values returned by the | |
6047 | ** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. | |
5783a860 | 6048 | */ |
08b809f9 | 6049 | SQLITE_API int SQLITE_STDCALL sqlite3_blob_close(sqlite3_blob *); |
5783a860 AC |
6050 | |
6051 | /* | |
08b809f9 EM |
6052 | ** CAPI3REF: Return The Size Of An Open BLOB |
6053 | ** METHOD: sqlite3_blob | |
6054 | ** | |
6055 | ** ^Returns the size in bytes of the BLOB accessible via the | |
6056 | ** successfully opened [BLOB handle] in its only argument. ^The | |
6057 | ** incremental blob I/O routines can only read or overwriting existing | |
6058 | ** blob content; they cannot change the size of a blob. | |
6059 | ** | |
6060 | ** This routine only works on a [BLOB handle] which has been created | |
6061 | ** by a prior successful call to [sqlite3_blob_open()] and which has not | |
6062 | ** been closed by [sqlite3_blob_close()]. Passing any other pointer in | |
6063 | ** to this routine results in undefined and probably undesirable behavior. | |
5783a860 | 6064 | */ |
08b809f9 | 6065 | SQLITE_API int SQLITE_STDCALL sqlite3_blob_bytes(sqlite3_blob *); |
5783a860 AC |
6066 | |
6067 | /* | |
08b809f9 EM |
6068 | ** CAPI3REF: Read Data From A BLOB Incrementally |
6069 | ** METHOD: sqlite3_blob | |
5783a860 | 6070 | ** |
08b809f9 EM |
6071 | ** ^(This function is used to read data from an open [BLOB handle] into a |
6072 | ** caller-supplied buffer. N bytes of data are copied into buffer Z | |
6073 | ** from the open BLOB, starting at offset iOffset.)^ | |
5783a860 | 6074 | ** |
08b809f9 EM |
6075 | ** ^If offset iOffset is less than N bytes from the end of the BLOB, |
6076 | ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is | |
6077 | ** less than zero, [SQLITE_ERROR] is returned and no data is read. | |
6078 | ** ^The size of the blob (and hence the maximum value of N+iOffset) | |
6079 | ** can be determined using the [sqlite3_blob_bytes()] interface. | |
5783a860 | 6080 | ** |
08b809f9 EM |
6081 | ** ^An attempt to read from an expired [BLOB handle] fails with an |
6082 | ** error code of [SQLITE_ABORT]. | |
5783a860 | 6083 | ** |
08b809f9 EM |
6084 | ** ^(On success, sqlite3_blob_read() returns SQLITE_OK. |
6085 | ** Otherwise, an [error code] or an [extended error code] is returned.)^ | |
5783a860 | 6086 | ** |
08b809f9 EM |
6087 | ** This routine only works on a [BLOB handle] which has been created |
6088 | ** by a prior successful call to [sqlite3_blob_open()] and which has not | |
6089 | ** been closed by [sqlite3_blob_close()]. Passing any other pointer in | |
6090 | ** to this routine results in undefined and probably undesirable behavior. | |
5783a860 | 6091 | ** |
08b809f9 EM |
6092 | ** See also: [sqlite3_blob_write()]. |
6093 | */ | |
6094 | SQLITE_API int SQLITE_STDCALL sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); | |
6095 | ||
6096 | /* | |
6097 | ** CAPI3REF: Write Data Into A BLOB Incrementally | |
6098 | ** METHOD: sqlite3_blob | |
6099 | ** | |
6100 | ** ^(This function is used to write data into an open [BLOB handle] from a | |
6101 | ** caller-supplied buffer. N bytes of data are copied from the buffer Z | |
6102 | ** into the open BLOB, starting at offset iOffset.)^ | |
6103 | ** | |
6104 | ** ^(On success, sqlite3_blob_write() returns SQLITE_OK. | |
6105 | ** Otherwise, an [error code] or an [extended error code] is returned.)^ | |
6106 | ** ^Unless SQLITE_MISUSE is returned, this function sets the | |
6107 | ** [database connection] error code and message accessible via | |
6108 | ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. | |
6109 | ** | |
6110 | ** ^If the [BLOB handle] passed as the first argument was not opened for | |
6111 | ** writing (the flags parameter to [sqlite3_blob_open()] was zero), | |
6112 | ** this function returns [SQLITE_READONLY]. | |
6113 | ** | |
6114 | ** This function may only modify the contents of the BLOB; it is | |
6115 | ** not possible to increase the size of a BLOB using this API. | |
6116 | ** ^If offset iOffset is less than N bytes from the end of the BLOB, | |
6117 | ** [SQLITE_ERROR] is returned and no data is written. The size of the | |
6118 | ** BLOB (and hence the maximum value of N+iOffset) can be determined | |
6119 | ** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less | |
6120 | ** than zero [SQLITE_ERROR] is returned and no data is written. | |
6121 | ** | |
6122 | ** ^An attempt to write to an expired [BLOB handle] fails with an | |
6123 | ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred | |
6124 | ** before the [BLOB handle] expired are not rolled back by the | |
6125 | ** expiration of the handle, though of course those changes might | |
6126 | ** have been overwritten by the statement that expired the BLOB handle | |
6127 | ** or by other independent statements. | |
6128 | ** | |
6129 | ** This routine only works on a [BLOB handle] which has been created | |
6130 | ** by a prior successful call to [sqlite3_blob_open()] and which has not | |
6131 | ** been closed by [sqlite3_blob_close()]. Passing any other pointer in | |
6132 | ** to this routine results in undefined and probably undesirable behavior. | |
6133 | ** | |
6134 | ** See also: [sqlite3_blob_read()]. | |
5783a860 | 6135 | */ |
08b809f9 | 6136 | SQLITE_API int SQLITE_STDCALL sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); |
5783a860 AC |
6137 | |
6138 | /* | |
08b809f9 | 6139 | ** CAPI3REF: Virtual File System Objects |
5783a860 AC |
6140 | ** |
6141 | ** A virtual filesystem (VFS) is an [sqlite3_vfs] object | |
6142 | ** that SQLite uses to interact | |
6143 | ** with the underlying operating system. Most SQLite builds come with a | |
6144 | ** single default VFS that is appropriate for the host computer. | |
6145 | ** New VFSes can be registered and existing VFSes can be unregistered. | |
6146 | ** The following interfaces are provided. | |
6147 | ** | |
08b809f9 EM |
6148 | ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. |
6149 | ** ^Names are case sensitive. | |
6150 | ** ^Names are zero-terminated UTF-8 strings. | |
6151 | ** ^If there is no match, a NULL pointer is returned. | |
6152 | ** ^If zVfsName is NULL then the default VFS is returned. | |
6153 | ** | |
6154 | ** ^New VFSes are registered with sqlite3_vfs_register(). | |
6155 | ** ^Each new VFS becomes the default VFS if the makeDflt flag is set. | |
6156 | ** ^The same VFS can be registered multiple times without injury. | |
6157 | ** ^To make an existing VFS into the default VFS, register it again | |
5783a860 AC |
6158 | ** with the makeDflt flag set. If two different VFSes with the |
6159 | ** same name are registered, the behavior is undefined. If a | |
6160 | ** VFS is registered with a name that is NULL or an empty string, | |
6161 | ** then the behavior is undefined. | |
4094d2fa | 6162 | ** |
08b809f9 EM |
6163 | ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. |
6164 | ** ^(If the default VFS is unregistered, another VFS is chosen as | |
6165 | ** the default. The choice for the new VFS is arbitrary.)^ | |
5783a860 | 6166 | */ |
08b809f9 EM |
6167 | SQLITE_API sqlite3_vfs *SQLITE_STDCALL sqlite3_vfs_find(const char *zVfsName); |
6168 | SQLITE_API int SQLITE_STDCALL sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); | |
6169 | SQLITE_API int SQLITE_STDCALL sqlite3_vfs_unregister(sqlite3_vfs*); | |
5783a860 AC |
6170 | |
6171 | /* | |
08b809f9 | 6172 | ** CAPI3REF: Mutexes |
5783a860 AC |
6173 | ** |
6174 | ** The SQLite core uses these routines for thread | |
08b809f9 | 6175 | ** synchronization. Though they are intended for internal |
5783a860 AC |
6176 | ** use by SQLite, code that links against SQLite is |
6177 | ** permitted to use any of these routines. | |
6178 | ** | |
4094d2fa | 6179 | ** The SQLite source code contains multiple implementations |
5783a860 AC |
6180 | ** of these mutex routines. An appropriate implementation |
6181 | ** is selected automatically at compile-time. The following | |
6182 | ** implementations are available in the SQLite core: | |
6183 | ** | |
6184 | ** <ul> | |
08b809f9 | 6185 | ** <li> SQLITE_MUTEX_PTHREADS |
5783a860 AC |
6186 | ** <li> SQLITE_MUTEX_W32 |
6187 | ** <li> SQLITE_MUTEX_NOOP | |
6188 | ** </ul> | |
6189 | ** | |
4094d2fa EM |
6190 | ** The SQLITE_MUTEX_NOOP implementation is a set of routines |
6191 | ** that does no real locking and is appropriate for use in | |
08b809f9 EM |
6192 | ** a single-threaded application. The SQLITE_MUTEX_PTHREADS and |
6193 | ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix | |
6194 | ** and Windows. | |
4094d2fa | 6195 | ** |
5783a860 AC |
6196 | ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor |
6197 | ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex | |
08b809f9 EM |
6198 | ** implementation is included with the library. In this case the |
6199 | ** application must supply a custom mutex implementation using the | |
6200 | ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function | |
6201 | ** before calling sqlite3_initialize() or any other public sqlite3_ | |
6202 | ** function that calls sqlite3_initialize(). | |
6203 | ** | |
6204 | ** ^The sqlite3_mutex_alloc() routine allocates a new | |
6205 | ** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() | |
6206 | ** routine returns NULL if it is unable to allocate the requested | |
6207 | ** mutex. The argument to sqlite3_mutex_alloc() must one of these | |
6208 | ** integer constants: | |
5783a860 AC |
6209 | ** |
6210 | ** <ul> | |
6211 | ** <li> SQLITE_MUTEX_FAST | |
6212 | ** <li> SQLITE_MUTEX_RECURSIVE | |
6213 | ** <li> SQLITE_MUTEX_STATIC_MASTER | |
6214 | ** <li> SQLITE_MUTEX_STATIC_MEM | |
08b809f9 | 6215 | ** <li> SQLITE_MUTEX_STATIC_OPEN |
5783a860 AC |
6216 | ** <li> SQLITE_MUTEX_STATIC_PRNG |
6217 | ** <li> SQLITE_MUTEX_STATIC_LRU | |
08b809f9 EM |
6218 | ** <li> SQLITE_MUTEX_STATIC_PMEM |
6219 | ** <li> SQLITE_MUTEX_STATIC_APP1 | |
6220 | ** <li> SQLITE_MUTEX_STATIC_APP2 | |
6221 | ** <li> SQLITE_MUTEX_STATIC_APP3 | |
6222 | ** <li> SQLITE_MUTEX_STATIC_VFS1 | |
6223 | ** <li> SQLITE_MUTEX_STATIC_VFS2 | |
6224 | ** <li> SQLITE_MUTEX_STATIC_VFS3 | |
6225 | ** </ul> | |
5783a860 | 6226 | ** |
08b809f9 EM |
6227 | ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) |
6228 | ** cause sqlite3_mutex_alloc() to create | |
6229 | ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE | |
6230 | ** is used but not necessarily so when SQLITE_MUTEX_FAST is used. | |
5783a860 AC |
6231 | ** The mutex implementation does not need to make a distinction |
6232 | ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does | |
08b809f9 EM |
6233 | ** not want to. SQLite will only request a recursive mutex in |
6234 | ** cases where it really needs one. If a faster non-recursive mutex | |
5783a860 AC |
6235 | ** implementation is available on the host platform, the mutex subsystem |
6236 | ** might return such a mutex in response to SQLITE_MUTEX_FAST. | |
6237 | ** | |
08b809f9 EM |
6238 | ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other |
6239 | ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return | |
6240 | ** a pointer to a static preexisting mutex. ^Nine static mutexes are | |
5783a860 AC |
6241 | ** used by the current version of SQLite. Future versions of SQLite |
6242 | ** may add additional static mutexes. Static mutexes are for internal | |
6243 | ** use by SQLite only. Applications that use SQLite mutexes should | |
6244 | ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or | |
6245 | ** SQLITE_MUTEX_RECURSIVE. | |
6246 | ** | |
08b809f9 | 6247 | ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST |
5783a860 | 6248 | ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() |
08b809f9 | 6249 | ** returns a different mutex on every call. ^For the static |
5783a860 | 6250 | ** mutex types, the same mutex is returned on every call that has |
08b809f9 | 6251 | ** the same type number. |
5783a860 | 6252 | ** |
08b809f9 EM |
6253 | ** ^The sqlite3_mutex_free() routine deallocates a previously |
6254 | ** allocated dynamic mutex. Attempting to deallocate a static | |
6255 | ** mutex results in undefined behavior. | |
5783a860 | 6256 | ** |
08b809f9 EM |
6257 | ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt |
6258 | ** to enter a mutex. ^If another thread is already within the mutex, | |
5783a860 | 6259 | ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return |
08b809f9 EM |
6260 | ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] |
6261 | ** upon successful entry. ^(Mutexes created using | |
5783a860 | 6262 | ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. |
08b809f9 | 6263 | ** In such cases, the |
5783a860 | 6264 | ** mutex must be exited an equal number of times before another thread |
08b809f9 EM |
6265 | ** can enter.)^ If the same thread tries to enter any mutex other |
6266 | ** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. | |
6267 | ** | |
6268 | ** ^(Some systems (for example, Windows 95) do not support the operation | |
6269 | ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() | |
6270 | ** will always return SQLITE_BUSY. The SQLite core only ever uses | |
6271 | ** sqlite3_mutex_try() as an optimization so this is acceptable | |
6272 | ** behavior.)^ | |
6273 | ** | |
6274 | ** ^The sqlite3_mutex_leave() routine exits a mutex that was | |
6275 | ** previously entered by the same thread. The behavior | |
5783a860 | 6276 | ** is undefined if the mutex is not currently entered by the |
08b809f9 EM |
6277 | ** calling thread or is not currently allocated. |
6278 | ** | |
6279 | ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or | |
6280 | ** sqlite3_mutex_leave() is a NULL pointer, then all three routines | |
6281 | ** behave as no-ops. | |
5783a860 AC |
6282 | ** |
6283 | ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. | |
6284 | */ | |
08b809f9 EM |
6285 | SQLITE_API sqlite3_mutex *SQLITE_STDCALL sqlite3_mutex_alloc(int); |
6286 | SQLITE_API void SQLITE_STDCALL sqlite3_mutex_free(sqlite3_mutex*); | |
6287 | SQLITE_API void SQLITE_STDCALL sqlite3_mutex_enter(sqlite3_mutex*); | |
6288 | SQLITE_API int SQLITE_STDCALL sqlite3_mutex_try(sqlite3_mutex*); | |
6289 | SQLITE_API void SQLITE_STDCALL sqlite3_mutex_leave(sqlite3_mutex*); | |
6290 | ||
6291 | /* | |
6292 | ** CAPI3REF: Mutex Methods Object | |
6293 | ** | |
6294 | ** An instance of this structure defines the low-level routines | |
6295 | ** used to allocate and use mutexes. | |
6296 | ** | |
6297 | ** Usually, the default mutex implementations provided by SQLite are | |
6298 | ** sufficient, however the application has the option of substituting a custom | |
6299 | ** implementation for specialized deployments or systems for which SQLite | |
6300 | ** does not provide a suitable implementation. In this case, the application | |
6301 | ** creates and populates an instance of this structure to pass | |
6302 | ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. | |
6303 | ** Additionally, an instance of this structure can be used as an | |
6304 | ** output variable when querying the system for the current mutex | |
6305 | ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. | |
6306 | ** | |
6307 | ** ^The xMutexInit method defined by this structure is invoked as | |
6308 | ** part of system initialization by the sqlite3_initialize() function. | |
6309 | ** ^The xMutexInit routine is called by SQLite exactly once for each | |
6310 | ** effective call to [sqlite3_initialize()]. | |
6311 | ** | |
6312 | ** ^The xMutexEnd method defined by this structure is invoked as | |
6313 | ** part of system shutdown by the sqlite3_shutdown() function. The | |
6314 | ** implementation of this method is expected to release all outstanding | |
6315 | ** resources obtained by the mutex methods implementation, especially | |
6316 | ** those obtained by the xMutexInit method. ^The xMutexEnd() | |
6317 | ** interface is invoked exactly once for each call to [sqlite3_shutdown()]. | |
6318 | ** | |
6319 | ** ^(The remaining seven methods defined by this structure (xMutexAlloc, | |
6320 | ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and | |
6321 | ** xMutexNotheld) implement the following interfaces (respectively): | |
6322 | ** | |
6323 | ** <ul> | |
6324 | ** <li> [sqlite3_mutex_alloc()] </li> | |
6325 | ** <li> [sqlite3_mutex_free()] </li> | |
6326 | ** <li> [sqlite3_mutex_enter()] </li> | |
6327 | ** <li> [sqlite3_mutex_try()] </li> | |
6328 | ** <li> [sqlite3_mutex_leave()] </li> | |
6329 | ** <li> [sqlite3_mutex_held()] </li> | |
6330 | ** <li> [sqlite3_mutex_notheld()] </li> | |
6331 | ** </ul>)^ | |
6332 | ** | |
6333 | ** The only difference is that the public sqlite3_XXX functions enumerated | |
6334 | ** above silently ignore any invocations that pass a NULL pointer instead | |
6335 | ** of a valid mutex handle. The implementations of the methods defined | |
6336 | ** by this structure are not required to handle this case, the results | |
6337 | ** of passing a NULL pointer instead of a valid mutex handle are undefined | |
6338 | ** (i.e. it is acceptable to provide an implementation that segfaults if | |
6339 | ** it is passed a NULL pointer). | |
6340 | ** | |
6341 | ** The xMutexInit() method must be threadsafe. It must be harmless to | |
6342 | ** invoke xMutexInit() multiple times within the same process and without | |
6343 | ** intervening calls to xMutexEnd(). Second and subsequent calls to | |
6344 | ** xMutexInit() must be no-ops. | |
6345 | ** | |
6346 | ** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] | |
6347 | ** and its associates). Similarly, xMutexAlloc() must not use SQLite memory | |
6348 | ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite | |
6349 | ** memory allocation for a fast or recursive mutex. | |
6350 | ** | |
6351 | ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is | |
6352 | ** called, but only if the prior call to xMutexInit returned SQLITE_OK. | |
6353 | ** If xMutexInit fails in any way, it is expected to clean up after itself | |
6354 | ** prior to returning. | |
6355 | */ | |
6356 | typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; | |
6357 | struct sqlite3_mutex_methods { | |
6358 | int (*xMutexInit)(void); | |
6359 | int (*xMutexEnd)(void); | |
6360 | sqlite3_mutex *(*xMutexAlloc)(int); | |
6361 | void (*xMutexFree)(sqlite3_mutex *); | |
6362 | void (*xMutexEnter)(sqlite3_mutex *); | |
6363 | int (*xMutexTry)(sqlite3_mutex *); | |
6364 | void (*xMutexLeave)(sqlite3_mutex *); | |
6365 | int (*xMutexHeld)(sqlite3_mutex *); | |
6366 | int (*xMutexNotheld)(sqlite3_mutex *); | |
6367 | }; | |
5783a860 AC |
6368 | |
6369 | /* | |
08b809f9 | 6370 | ** CAPI3REF: Mutex Verification Routines |
5783a860 AC |
6371 | ** |
6372 | ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines | |
08b809f9 | 6373 | ** are intended for use inside assert() statements. The SQLite core |
5783a860 | 6374 | ** never uses these routines except inside an assert() and applications |
08b809f9 | 6375 | ** are advised to follow the lead of the core. The SQLite core only |
5783a860 | 6376 | ** provides implementations for these routines when it is compiled |
08b809f9 | 6377 | ** with the SQLITE_DEBUG flag. External mutex implementations |
5783a860 AC |
6378 | ** are only required to provide these routines if SQLITE_DEBUG is |
6379 | ** defined and if NDEBUG is not defined. | |
6380 | ** | |
08b809f9 EM |
6381 | ** These routines should return true if the mutex in their argument |
6382 | ** is held or not held, respectively, by the calling thread. | |
5783a860 | 6383 | ** |
08b809f9 EM |
6384 | ** The implementation is not required to provide versions of these |
6385 | ** routines that actually work. If the implementation does not provide working | |
6386 | ** versions of these routines, it should at least provide stubs that always | |
6387 | ** return true so that one does not get spurious assertion failures. | |
5783a860 | 6388 | ** |
08b809f9 EM |
6389 | ** If the argument to sqlite3_mutex_held() is a NULL pointer then |
6390 | ** the routine should return 1. This seems counter-intuitive since | |
6391 | ** clearly the mutex cannot be held if it does not exist. But | |
5783a860 AC |
6392 | ** the reason the mutex does not exist is because the build is not |
6393 | ** using mutexes. And we do not want the assert() containing the | |
6394 | ** call to sqlite3_mutex_held() to fail, so a non-zero return is | |
08b809f9 | 6395 | ** the appropriate thing to do. The sqlite3_mutex_notheld() |
5783a860 AC |
6396 | ** interface should also return 1 when given a NULL pointer. |
6397 | */ | |
08b809f9 EM |
6398 | #ifndef NDEBUG |
6399 | SQLITE_API int SQLITE_STDCALL sqlite3_mutex_held(sqlite3_mutex*); | |
6400 | SQLITE_API int SQLITE_STDCALL sqlite3_mutex_notheld(sqlite3_mutex*); | |
6401 | #endif | |
5783a860 AC |
6402 | |
6403 | /* | |
08b809f9 | 6404 | ** CAPI3REF: Mutex Types |
5783a860 | 6405 | ** |
08b809f9 EM |
6406 | ** The [sqlite3_mutex_alloc()] interface takes a single argument |
6407 | ** which is one of these integer constants. | |
6408 | ** | |
6409 | ** The set of static mutexes may change from one SQLite release to the | |
6410 | ** next. Applications that override the built-in mutex logic must be | |
6411 | ** prepared to accommodate additional static mutexes. | |
5783a860 AC |
6412 | */ |
6413 | #define SQLITE_MUTEX_FAST 0 | |
6414 | #define SQLITE_MUTEX_RECURSIVE 1 | |
6415 | #define SQLITE_MUTEX_STATIC_MASTER 2 | |
6416 | #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ | |
08b809f9 EM |
6417 | #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ |
6418 | #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ | |
5783a860 AC |
6419 | #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */ |
6420 | #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ | |
08b809f9 EM |
6421 | #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ |
6422 | #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ | |
6423 | #define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ | |
6424 | #define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ | |
6425 | #define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ | |
6426 | #define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ | |
6427 | #define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ | |
6428 | #define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ | |
5783a860 AC |
6429 | |
6430 | /* | |
08b809f9 EM |
6431 | ** CAPI3REF: Retrieve the mutex for a database connection |
6432 | ** METHOD: sqlite3 | |
6433 | ** | |
6434 | ** ^This interface returns a pointer the [sqlite3_mutex] object that | |
6435 | ** serializes access to the [database connection] given in the argument | |
6436 | ** when the [threading mode] is Serialized. | |
6437 | ** ^If the [threading mode] is Single-thread or Multi-thread then this | |
6438 | ** routine returns a NULL pointer. | |
6439 | */ | |
6440 | SQLITE_API sqlite3_mutex *SQLITE_STDCALL sqlite3_db_mutex(sqlite3*); | |
6441 | ||
6442 | /* | |
6443 | ** CAPI3REF: Low-Level Control Of Database Files | |
6444 | ** METHOD: sqlite3 | |
5783a860 | 6445 | ** |
08b809f9 | 6446 | ** ^The [sqlite3_file_control()] interface makes a direct call to the |
5783a860 | 6447 | ** xFileControl method for the [sqlite3_io_methods] object associated |
08b809f9 EM |
6448 | ** with a particular database identified by the second argument. ^The |
6449 | ** name of the database is "main" for the main database or "temp" for the | |
6450 | ** TEMP database, or the name that appears after the AS keyword for | |
6451 | ** databases that are added using the [ATTACH] SQL command. | |
6452 | ** ^A NULL pointer can be used in place of "main" to refer to the | |
6453 | ** main database file. | |
6454 | ** ^The third and fourth parameters to this routine | |
5783a860 | 6455 | ** are passed directly through to the second and third parameters of |
08b809f9 | 6456 | ** the xFileControl method. ^The return value of the xFileControl |
5783a860 AC |
6457 | ** method becomes the return value of this routine. |
6458 | ** | |
08b809f9 EM |
6459 | ** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes |
6460 | ** a pointer to the underlying [sqlite3_file] object to be written into | |
6461 | ** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER | |
6462 | ** case is a short-circuit path which does not actually invoke the | |
6463 | ** underlying sqlite3_io_methods.xFileControl method. | |
6464 | ** | |
6465 | ** ^If the second parameter (zDbName) does not match the name of any | |
6466 | ** open database file, then SQLITE_ERROR is returned. ^This error | |
5783a860 | 6467 | ** code is not remembered and will not be recalled by [sqlite3_errcode()] |
08b809f9 EM |
6468 | ** or [sqlite3_errmsg()]. The underlying xFileControl method might |
6469 | ** also return SQLITE_ERROR. There is no way to distinguish between | |
5783a860 | 6470 | ** an incorrect zDbName and an SQLITE_ERROR return from the underlying |
08b809f9 | 6471 | ** xFileControl method. |
5783a860 AC |
6472 | ** |
6473 | ** See also: [SQLITE_FCNTL_LOCKSTATE] | |
6474 | */ | |
08b809f9 | 6475 | SQLITE_API int SQLITE_STDCALL sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); |
5783a860 AC |
6476 | |
6477 | /* | |
08b809f9 | 6478 | ** CAPI3REF: Testing Interface |
5783a860 | 6479 | ** |
08b809f9 | 6480 | ** ^The sqlite3_test_control() interface is used to read out internal |
5783a860 | 6481 | ** state of SQLite and to inject faults into SQLite for testing |
08b809f9 | 6482 | ** purposes. ^The first parameter is an operation code that determines |
5783a860 AC |
6483 | ** the number, meaning, and operation of all subsequent parameters. |
6484 | ** | |
6485 | ** This interface is not for use by applications. It exists solely | |
6486 | ** for verifying the correct operation of the SQLite library. Depending | |
6487 | ** on how the SQLite library is compiled, this interface might not exist. | |
6488 | ** | |
6489 | ** The details of the operation codes, their meanings, the parameters | |
6490 | ** they take, and what they do are all subject to change without notice. | |
6491 | ** Unlike most of the SQLite API, this function is not guaranteed to | |
6492 | ** operate consistently from one release to the next. | |
6493 | */ | |
08b809f9 | 6494 | SQLITE_API int SQLITE_CDECL sqlite3_test_control(int op, ...); |
5783a860 AC |
6495 | |
6496 | /* | |
08b809f9 | 6497 | ** CAPI3REF: Testing Interface Operation Codes |
5783a860 AC |
6498 | ** |
6499 | ** These constants are the valid operation code parameters used | |
6500 | ** as the first argument to [sqlite3_test_control()]. | |
6501 | ** | |
08b809f9 | 6502 | ** These parameters and their meanings are subject to change |
5783a860 AC |
6503 | ** without notice. These values are for testing purposes only. |
6504 | ** Applications should not use any of these parameters or the | |
6505 | ** [sqlite3_test_control()] interface. | |
6506 | */ | |
08b809f9 | 6507 | #define SQLITE_TESTCTRL_FIRST 5 |
5783a860 AC |
6508 | #define SQLITE_TESTCTRL_PRNG_SAVE 5 |
6509 | #define SQLITE_TESTCTRL_PRNG_RESTORE 6 | |
6510 | #define SQLITE_TESTCTRL_PRNG_RESET 7 | |
6511 | #define SQLITE_TESTCTRL_BITVEC_TEST 8 | |
08b809f9 EM |
6512 | #define SQLITE_TESTCTRL_FAULT_INSTALL 9 |
6513 | #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 | |
6514 | #define SQLITE_TESTCTRL_PENDING_BYTE 11 | |
6515 | #define SQLITE_TESTCTRL_ASSERT 12 | |
6516 | #define SQLITE_TESTCTRL_ALWAYS 13 | |
6517 | #define SQLITE_TESTCTRL_RESERVE 14 | |
6518 | #define SQLITE_TESTCTRL_OPTIMIZATIONS 15 | |
6519 | #define SQLITE_TESTCTRL_ISKEYWORD 16 | |
6520 | #define SQLITE_TESTCTRL_SCRATCHMALLOC 17 | |
6521 | #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 | |
6522 | #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ | |
6523 | #define SQLITE_TESTCTRL_NEVER_CORRUPT 20 | |
6524 | #define SQLITE_TESTCTRL_VDBE_COVERAGE 21 | |
6525 | #define SQLITE_TESTCTRL_BYTEORDER 22 | |
6526 | #define SQLITE_TESTCTRL_ISINIT 23 | |
6527 | #define SQLITE_TESTCTRL_SORTER_MMAP 24 | |
6528 | #define SQLITE_TESTCTRL_IMPOSTER 25 | |
6529 | #define SQLITE_TESTCTRL_LAST 25 | |
6530 | ||
6531 | /* | |
6532 | ** CAPI3REF: SQLite Runtime Status | |
6533 | ** | |
6534 | ** ^These interfaces are used to retrieve runtime status information | |
6535 | ** about the performance of SQLite, and optionally to reset various | |
6536 | ** highwater marks. ^The first argument is an integer code for | |
6537 | ** the specific parameter to measure. ^(Recognized integer codes | |
6538 | ** are of the form [status parameters | SQLITE_STATUS_...].)^ | |
6539 | ** ^The current value of the parameter is returned into *pCurrent. | |
6540 | ** ^The highest recorded value is returned in *pHighwater. ^If the | |
6541 | ** resetFlag is true, then the highest record value is reset after | |
6542 | ** *pHighwater is written. ^(Some parameters do not record the highest | |
6543 | ** value. For those parameters | |
6544 | ** nothing is written into *pHighwater and the resetFlag is ignored.)^ | |
6545 | ** ^(Other parameters record only the highwater mark and not the current | |
6546 | ** value. For these latter parameters nothing is written into *pCurrent.)^ | |
6547 | ** | |
6548 | ** ^The sqlite3_status() and sqlite3_status64() routines return | |
6549 | ** SQLITE_OK on success and a non-zero [error code] on failure. | |
6550 | ** | |
6551 | ** If either the current value or the highwater mark is too large to | |
6552 | ** be represented by a 32-bit integer, then the values returned by | |
6553 | ** sqlite3_status() are undefined. | |
6554 | ** | |
6555 | ** See also: [sqlite3_db_status()] | |
6556 | */ | |
6557 | SQLITE_API int SQLITE_STDCALL sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); | |
6558 | SQLITE_API int SQLITE_STDCALL sqlite3_status64( | |
6559 | int op, | |
6560 | sqlite3_int64 *pCurrent, | |
6561 | sqlite3_int64 *pHighwater, | |
6562 | int resetFlag | |
6563 | ); | |
6564 | ||
6565 | ||
6566 | /* | |
6567 | ** CAPI3REF: Status Parameters | |
6568 | ** KEYWORDS: {status parameters} | |
6569 | ** | |
6570 | ** These integer constants designate various run-time status parameters | |
6571 | ** that can be returned by [sqlite3_status()]. | |
6572 | ** | |
6573 | ** <dl> | |
6574 | ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> | |
6575 | ** <dd>This parameter is the current amount of memory checked out | |
6576 | ** using [sqlite3_malloc()], either directly or indirectly. The | |
6577 | ** figure includes calls made to [sqlite3_malloc()] by the application | |
6578 | ** and internal memory usage by the SQLite library. Scratch memory | |
6579 | ** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache | |
6580 | ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in | |
6581 | ** this parameter. The amount returned is the sum of the allocation | |
6582 | ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ | |
6583 | ** | |
6584 | ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> | |
6585 | ** <dd>This parameter records the largest memory allocation request | |
6586 | ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their | |
6587 | ** internal equivalents). Only the value returned in the | |
6588 | ** *pHighwater parameter to [sqlite3_status()] is of interest. | |
6589 | ** The value written into the *pCurrent parameter is undefined.</dd>)^ | |
6590 | ** | |
6591 | ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> | |
6592 | ** <dd>This parameter records the number of separate memory allocations | |
6593 | ** currently checked out.</dd>)^ | |
6594 | ** | |
6595 | ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> | |
6596 | ** <dd>This parameter returns the number of pages used out of the | |
6597 | ** [pagecache memory allocator] that was configured using | |
6598 | ** [SQLITE_CONFIG_PAGECACHE]. The | |
6599 | ** value returned is in pages, not in bytes.</dd>)^ | |
6600 | ** | |
6601 | ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] | |
6602 | ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> | |
6603 | ** <dd>This parameter returns the number of bytes of page cache | |
6604 | ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] | |
6605 | ** buffer and where forced to overflow to [sqlite3_malloc()]. The | |
6606 | ** returned value includes allocations that overflowed because they | |
6607 | ** where too large (they were larger than the "sz" parameter to | |
6608 | ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because | |
6609 | ** no space was left in the page cache.</dd>)^ | |
6610 | ** | |
6611 | ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> | |
6612 | ** <dd>This parameter records the largest memory allocation request | |
6613 | ** handed to [pagecache memory allocator]. Only the value returned in the | |
6614 | ** *pHighwater parameter to [sqlite3_status()] is of interest. | |
6615 | ** The value written into the *pCurrent parameter is undefined.</dd>)^ | |
6616 | ** | |
6617 | ** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt> | |
6618 | ** <dd>This parameter returns the number of allocations used out of the | |
6619 | ** [scratch memory allocator] configured using | |
6620 | ** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not | |
6621 | ** in bytes. Since a single thread may only have one scratch allocation | |
6622 | ** outstanding at time, this parameter also reports the number of threads | |
6623 | ** using scratch memory at the same time.</dd>)^ | |
6624 | ** | |
6625 | ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> | |
6626 | ** <dd>This parameter returns the number of bytes of scratch memory | |
6627 | ** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH] | |
6628 | ** buffer and where forced to overflow to [sqlite3_malloc()]. The values | |
6629 | ** returned include overflows because the requested allocation was too | |
6630 | ** larger (that is, because the requested allocation was larger than the | |
6631 | ** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer | |
6632 | ** slots were available. | |
6633 | ** </dd>)^ | |
6634 | ** | |
6635 | ** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt> | |
6636 | ** <dd>This parameter records the largest memory allocation request | |
6637 | ** handed to [scratch memory allocator]. Only the value returned in the | |
6638 | ** *pHighwater parameter to [sqlite3_status()] is of interest. | |
6639 | ** The value written into the *pCurrent parameter is undefined.</dd>)^ | |
6640 | ** | |
6641 | ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> | |
6642 | ** <dd>The *pHighwater parameter records the deepest parser stack. | |
6643 | ** The *pCurrent value is undefined. The *pHighwater value is only | |
6644 | ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ | |
6645 | ** </dl> | |
6646 | ** | |
6647 | ** New status parameters may be added from time to time. | |
6648 | */ | |
6649 | #define SQLITE_STATUS_MEMORY_USED 0 | |
6650 | #define SQLITE_STATUS_PAGECACHE_USED 1 | |
6651 | #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 | |
6652 | #define SQLITE_STATUS_SCRATCH_USED 3 | |
6653 | #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 | |
6654 | #define SQLITE_STATUS_MALLOC_SIZE 5 | |
6655 | #define SQLITE_STATUS_PARSER_STACK 6 | |
6656 | #define SQLITE_STATUS_PAGECACHE_SIZE 7 | |
6657 | #define SQLITE_STATUS_SCRATCH_SIZE 8 | |
6658 | #define SQLITE_STATUS_MALLOC_COUNT 9 | |
6659 | ||
6660 | /* | |
6661 | ** CAPI3REF: Database Connection Status | |
6662 | ** METHOD: sqlite3 | |
6663 | ** | |
6664 | ** ^This interface is used to retrieve runtime status information | |
6665 | ** about a single [database connection]. ^The first argument is the | |
6666 | ** database connection object to be interrogated. ^The second argument | |
6667 | ** is an integer constant, taken from the set of | |
6668 | ** [SQLITE_DBSTATUS options], that | |
6669 | ** determines the parameter to interrogate. The set of | |
6670 | ** [SQLITE_DBSTATUS options] is likely | |
6671 | ** to grow in future releases of SQLite. | |
6672 | ** | |
6673 | ** ^The current value of the requested parameter is written into *pCur | |
6674 | ** and the highest instantaneous value is written into *pHiwtr. ^If | |
6675 | ** the resetFlg is true, then the highest instantaneous value is | |
6676 | ** reset back down to the current value. | |
6677 | ** | |
6678 | ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a | |
6679 | ** non-zero [error code] on failure. | |
6680 | ** | |
6681 | ** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. | |
6682 | */ | |
6683 | SQLITE_API int SQLITE_STDCALL sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); | |
6684 | ||
6685 | /* | |
6686 | ** CAPI3REF: Status Parameters for database connections | |
6687 | ** KEYWORDS: {SQLITE_DBSTATUS options} | |
6688 | ** | |
6689 | ** These constants are the available integer "verbs" that can be passed as | |
6690 | ** the second argument to the [sqlite3_db_status()] interface. | |
6691 | ** | |
6692 | ** New verbs may be added in future releases of SQLite. Existing verbs | |
6693 | ** might be discontinued. Applications should check the return code from | |
6694 | ** [sqlite3_db_status()] to make sure that the call worked. | |
6695 | ** The [sqlite3_db_status()] interface will return a non-zero error code | |
6696 | ** if a discontinued or unsupported verb is invoked. | |
6697 | ** | |
6698 | ** <dl> | |
6699 | ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> | |
6700 | ** <dd>This parameter returns the number of lookaside memory slots currently | |
6701 | ** checked out.</dd>)^ | |
6702 | ** | |
6703 | ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> | |
6704 | ** <dd>This parameter returns the number malloc attempts that were | |
6705 | ** satisfied using lookaside memory. Only the high-water value is meaningful; | |
6706 | ** the current value is always zero.)^ | |
6707 | ** | |
6708 | ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] | |
6709 | ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> | |
6710 | ** <dd>This parameter returns the number malloc attempts that might have | |
6711 | ** been satisfied using lookaside memory but failed due to the amount of | |
6712 | ** memory requested being larger than the lookaside slot size. | |
6713 | ** Only the high-water value is meaningful; | |
6714 | ** the current value is always zero.)^ | |
6715 | ** | |
6716 | ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] | |
6717 | ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> | |
6718 | ** <dd>This parameter returns the number malloc attempts that might have | |
6719 | ** been satisfied using lookaside memory but failed due to all lookaside | |
6720 | ** memory already being in use. | |
6721 | ** Only the high-water value is meaningful; | |
6722 | ** the current value is always zero.)^ | |
6723 | ** | |
6724 | ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> | |
6725 | ** <dd>This parameter returns the approximate number of bytes of heap | |
6726 | ** memory used by all pager caches associated with the database connection.)^ | |
6727 | ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. | |
6728 | ** | |
6729 | ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> | |
6730 | ** <dd>This parameter returns the approximate number of bytes of heap | |
6731 | ** memory used to store the schema for all databases associated | |
6732 | ** with the connection - main, temp, and any [ATTACH]-ed databases.)^ | |
6733 | ** ^The full amount of memory used by the schemas is reported, even if the | |
6734 | ** schema memory is shared with other database connections due to | |
6735 | ** [shared cache mode] being enabled. | |
6736 | ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. | |
6737 | ** | |
6738 | ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> | |
6739 | ** <dd>This parameter returns the approximate number of bytes of heap | |
6740 | ** and lookaside memory used by all prepared statements associated with | |
6741 | ** the database connection.)^ | |
6742 | ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. | |
6743 | ** </dd> | |
6744 | ** | |
6745 | ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> | |
6746 | ** <dd>This parameter returns the number of pager cache hits that have | |
6747 | ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT | |
6748 | ** is always 0. | |
6749 | ** </dd> | |
6750 | ** | |
6751 | ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> | |
6752 | ** <dd>This parameter returns the number of pager cache misses that have | |
6753 | ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS | |
6754 | ** is always 0. | |
6755 | ** </dd> | |
6756 | ** | |
6757 | ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> | |
6758 | ** <dd>This parameter returns the number of dirty cache entries that have | |
6759 | ** been written to disk. Specifically, the number of pages written to the | |
6760 | ** wal file in wal mode databases, or the number of pages written to the | |
6761 | ** database file in rollback mode databases. Any pages written as part of | |
6762 | ** transaction rollback or database recovery operations are not included. | |
6763 | ** If an IO or other error occurs while writing a page to disk, the effect | |
6764 | ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The | |
6765 | ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. | |
6766 | ** </dd> | |
6767 | ** | |
6768 | ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> | |
6769 | ** <dd>This parameter returns zero for the current value if and only if | |
6770 | ** all foreign key constraints (deferred or immediate) have been | |
6771 | ** resolved.)^ ^The highwater mark is always 0. | |
6772 | ** </dd> | |
6773 | ** </dl> | |
6774 | */ | |
6775 | #define SQLITE_DBSTATUS_LOOKASIDE_USED 0 | |
6776 | #define SQLITE_DBSTATUS_CACHE_USED 1 | |
6777 | #define SQLITE_DBSTATUS_SCHEMA_USED 2 | |
6778 | #define SQLITE_DBSTATUS_STMT_USED 3 | |
6779 | #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 | |
6780 | #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 | |
6781 | #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 | |
6782 | #define SQLITE_DBSTATUS_CACHE_HIT 7 | |
6783 | #define SQLITE_DBSTATUS_CACHE_MISS 8 | |
6784 | #define SQLITE_DBSTATUS_CACHE_WRITE 9 | |
6785 | #define SQLITE_DBSTATUS_DEFERRED_FKS 10 | |
6786 | #define SQLITE_DBSTATUS_MAX 10 /* Largest defined DBSTATUS */ | |
6787 | ||
6788 | ||
6789 | /* | |
6790 | ** CAPI3REF: Prepared Statement Status | |
6791 | ** METHOD: sqlite3_stmt | |
6792 | ** | |
6793 | ** ^(Each prepared statement maintains various | |
6794 | ** [SQLITE_STMTSTATUS counters] that measure the number | |
6795 | ** of times it has performed specific operations.)^ These counters can | |
6796 | ** be used to monitor the performance characteristics of the prepared | |
6797 | ** statements. For example, if the number of table steps greatly exceeds | |
6798 | ** the number of table searches or result rows, that would tend to indicate | |
6799 | ** that the prepared statement is using a full table scan rather than | |
6800 | ** an index. | |
6801 | ** | |
6802 | ** ^(This interface is used to retrieve and reset counter values from | |
6803 | ** a [prepared statement]. The first argument is the prepared statement | |
6804 | ** object to be interrogated. The second argument | |
6805 | ** is an integer code for a specific [SQLITE_STMTSTATUS counter] | |
6806 | ** to be interrogated.)^ | |
6807 | ** ^The current value of the requested counter is returned. | |
6808 | ** ^If the resetFlg is true, then the counter is reset to zero after this | |
6809 | ** interface call returns. | |
6810 | ** | |
6811 | ** See also: [sqlite3_status()] and [sqlite3_db_status()]. | |
6812 | */ | |
6813 | SQLITE_API int SQLITE_STDCALL sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); | |
6814 | ||
6815 | /* | |
6816 | ** CAPI3REF: Status Parameters for prepared statements | |
6817 | ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} | |
6818 | ** | |
6819 | ** These preprocessor macros define integer codes that name counter | |
6820 | ** values associated with the [sqlite3_stmt_status()] interface. | |
6821 | ** The meanings of the various counters are as follows: | |
6822 | ** | |
6823 | ** <dl> | |
6824 | ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> | |
6825 | ** <dd>^This is the number of times that SQLite has stepped forward in | |
6826 | ** a table as part of a full table scan. Large numbers for this counter | |
6827 | ** may indicate opportunities for performance improvement through | |
6828 | ** careful use of indices.</dd> | |
6829 | ** | |
6830 | ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> | |
6831 | ** <dd>^This is the number of sort operations that have occurred. | |
6832 | ** A non-zero value in this counter may indicate an opportunity to | |
6833 | ** improvement performance through careful use of indices.</dd> | |
6834 | ** | |
6835 | ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> | |
6836 | ** <dd>^This is the number of rows inserted into transient indices that | |
6837 | ** were created automatically in order to help joins run faster. | |
6838 | ** A non-zero value in this counter may indicate an opportunity to | |
6839 | ** improvement performance by adding permanent indices that do not | |
6840 | ** need to be reinitialized each time the statement is run.</dd> | |
6841 | ** | |
6842 | ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> | |
6843 | ** <dd>^This is the number of virtual machine operations executed | |
6844 | ** by the prepared statement if that number is less than or equal | |
6845 | ** to 2147483647. The number of virtual machine operations can be | |
6846 | ** used as a proxy for the total work done by the prepared statement. | |
6847 | ** If the number of virtual machine operations exceeds 2147483647 | |
6848 | ** then the value returned by this statement status code is undefined. | |
6849 | ** </dd> | |
6850 | ** </dl> | |
6851 | */ | |
6852 | #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 | |
6853 | #define SQLITE_STMTSTATUS_SORT 2 | |
6854 | #define SQLITE_STMTSTATUS_AUTOINDEX 3 | |
6855 | #define SQLITE_STMTSTATUS_VM_STEP 4 | |
6856 | ||
6857 | /* | |
6858 | ** CAPI3REF: Custom Page Cache Object | |
6859 | ** | |
6860 | ** The sqlite3_pcache type is opaque. It is implemented by | |
6861 | ** the pluggable module. The SQLite core has no knowledge of | |
6862 | ** its size or internal structure and never deals with the | |
6863 | ** sqlite3_pcache object except by holding and passing pointers | |
6864 | ** to the object. | |
6865 | ** | |
6866 | ** See [sqlite3_pcache_methods2] for additional information. | |
6867 | */ | |
6868 | typedef struct sqlite3_pcache sqlite3_pcache; | |
6869 | ||
6870 | /* | |
6871 | ** CAPI3REF: Custom Page Cache Object | |
6872 | ** | |
6873 | ** The sqlite3_pcache_page object represents a single page in the | |
6874 | ** page cache. The page cache will allocate instances of this | |
6875 | ** object. Various methods of the page cache use pointers to instances | |
6876 | ** of this object as parameters or as their return value. | |
6877 | ** | |
6878 | ** See [sqlite3_pcache_methods2] for additional information. | |
6879 | */ | |
6880 | typedef struct sqlite3_pcache_page sqlite3_pcache_page; | |
6881 | struct sqlite3_pcache_page { | |
6882 | void *pBuf; /* The content of the page */ | |
6883 | void *pExtra; /* Extra information associated with the page */ | |
6884 | }; | |
6885 | ||
6886 | /* | |
6887 | ** CAPI3REF: Application Defined Page Cache. | |
6888 | ** KEYWORDS: {page cache} | |
6889 | ** | |
6890 | ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can | |
6891 | ** register an alternative page cache implementation by passing in an | |
6892 | ** instance of the sqlite3_pcache_methods2 structure.)^ | |
6893 | ** In many applications, most of the heap memory allocated by | |
6894 | ** SQLite is used for the page cache. | |
6895 | ** By implementing a | |
6896 | ** custom page cache using this API, an application can better control | |
6897 | ** the amount of memory consumed by SQLite, the way in which | |
6898 | ** that memory is allocated and released, and the policies used to | |
6899 | ** determine exactly which parts of a database file are cached and for | |
6900 | ** how long. | |
6901 | ** | |
6902 | ** The alternative page cache mechanism is an | |
6903 | ** extreme measure that is only needed by the most demanding applications. | |
6904 | ** The built-in page cache is recommended for most uses. | |
6905 | ** | |
6906 | ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an | |
6907 | ** internal buffer by SQLite within the call to [sqlite3_config]. Hence | |
6908 | ** the application may discard the parameter after the call to | |
6909 | ** [sqlite3_config()] returns.)^ | |
6910 | ** | |
6911 | ** [[the xInit() page cache method]] | |
6912 | ** ^(The xInit() method is called once for each effective | |
6913 | ** call to [sqlite3_initialize()])^ | |
6914 | ** (usually only once during the lifetime of the process). ^(The xInit() | |
6915 | ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ | |
6916 | ** The intent of the xInit() method is to set up global data structures | |
6917 | ** required by the custom page cache implementation. | |
6918 | ** ^(If the xInit() method is NULL, then the | |
6919 | ** built-in default page cache is used instead of the application defined | |
6920 | ** page cache.)^ | |
6921 | ** | |
6922 | ** [[the xShutdown() page cache method]] | |
6923 | ** ^The xShutdown() method is called by [sqlite3_shutdown()]. | |
6924 | ** It can be used to clean up | |
6925 | ** any outstanding resources before process shutdown, if required. | |
6926 | ** ^The xShutdown() method may be NULL. | |
6927 | ** | |
6928 | ** ^SQLite automatically serializes calls to the xInit method, | |
6929 | ** so the xInit method need not be threadsafe. ^The | |
6930 | ** xShutdown method is only called from [sqlite3_shutdown()] so it does | |
6931 | ** not need to be threadsafe either. All other methods must be threadsafe | |
6932 | ** in multithreaded applications. | |
6933 | ** | |
6934 | ** ^SQLite will never invoke xInit() more than once without an intervening | |
6935 | ** call to xShutdown(). | |
6936 | ** | |
6937 | ** [[the xCreate() page cache methods]] | |
6938 | ** ^SQLite invokes the xCreate() method to construct a new cache instance. | |
6939 | ** SQLite will typically create one cache instance for each open database file, | |
6940 | ** though this is not guaranteed. ^The | |
6941 | ** first parameter, szPage, is the size in bytes of the pages that must | |
6942 | ** be allocated by the cache. ^szPage will always a power of two. ^The | |
6943 | ** second parameter szExtra is a number of bytes of extra storage | |
6944 | ** associated with each page cache entry. ^The szExtra parameter will | |
6945 | ** a number less than 250. SQLite will use the | |
6946 | ** extra szExtra bytes on each page to store metadata about the underlying | |
6947 | ** database page on disk. The value passed into szExtra depends | |
6948 | ** on the SQLite version, the target platform, and how SQLite was compiled. | |
6949 | ** ^The third argument to xCreate(), bPurgeable, is true if the cache being | |
6950 | ** created will be used to cache database pages of a file stored on disk, or | |
6951 | ** false if it is used for an in-memory database. The cache implementation | |
6952 | ** does not have to do anything special based with the value of bPurgeable; | |
6953 | ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will | |
6954 | ** never invoke xUnpin() except to deliberately delete a page. | |
6955 | ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to | |
6956 | ** false will always have the "discard" flag set to true. | |
6957 | ** ^Hence, a cache created with bPurgeable false will | |
6958 | ** never contain any unpinned pages. | |
6959 | ** | |
6960 | ** [[the xCachesize() page cache method]] | |
6961 | ** ^(The xCachesize() method may be called at any time by SQLite to set the | |
6962 | ** suggested maximum cache-size (number of pages stored by) the cache | |
6963 | ** instance passed as the first argument. This is the value configured using | |
6964 | ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable | |
6965 | ** parameter, the implementation is not required to do anything with this | |
6966 | ** value; it is advisory only. | |
6967 | ** | |
6968 | ** [[the xPagecount() page cache methods]] | |
6969 | ** The xPagecount() method must return the number of pages currently | |
6970 | ** stored in the cache, both pinned and unpinned. | |
6971 | ** | |
6972 | ** [[the xFetch() page cache methods]] | |
6973 | ** The xFetch() method locates a page in the cache and returns a pointer to | |
6974 | ** an sqlite3_pcache_page object associated with that page, or a NULL pointer. | |
6975 | ** The pBuf element of the returned sqlite3_pcache_page object will be a | |
6976 | ** pointer to a buffer of szPage bytes used to store the content of a | |
6977 | ** single database page. The pExtra element of sqlite3_pcache_page will be | |
6978 | ** a pointer to the szExtra bytes of extra storage that SQLite has requested | |
6979 | ** for each entry in the page cache. | |
6980 | ** | |
6981 | ** The page to be fetched is determined by the key. ^The minimum key value | |
6982 | ** is 1. After it has been retrieved using xFetch, the page is considered | |
6983 | ** to be "pinned". | |
6984 | ** | |
6985 | ** If the requested page is already in the page cache, then the page cache | |
6986 | ** implementation must return a pointer to the page buffer with its content | |
6987 | ** intact. If the requested page is not already in the cache, then the | |
6988 | ** cache implementation should use the value of the createFlag | |
6989 | ** parameter to help it determined what action to take: | |
6990 | ** | |
6991 | ** <table border=1 width=85% align=center> | |
6992 | ** <tr><th> createFlag <th> Behavior when page is not already in cache | |
6993 | ** <tr><td> 0 <td> Do not allocate a new page. Return NULL. | |
6994 | ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. | |
6995 | ** Otherwise return NULL. | |
6996 | ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return | |
6997 | ** NULL if allocating a new page is effectively impossible. | |
6998 | ** </table> | |
6999 | ** | |
7000 | ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite | |
7001 | ** will only use a createFlag of 2 after a prior call with a createFlag of 1 | |
7002 | ** failed.)^ In between the to xFetch() calls, SQLite may | |
7003 | ** attempt to unpin one or more cache pages by spilling the content of | |
7004 | ** pinned pages to disk and synching the operating system disk cache. | |
7005 | ** | |
7006 | ** [[the xUnpin() page cache method]] | |
7007 | ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page | |
7008 | ** as its second argument. If the third parameter, discard, is non-zero, | |
7009 | ** then the page must be evicted from the cache. | |
7010 | ** ^If the discard parameter is | |
7011 | ** zero, then the page may be discarded or retained at the discretion of | |
7012 | ** page cache implementation. ^The page cache implementation | |
7013 | ** may choose to evict unpinned pages at any time. | |
7014 | ** | |
7015 | ** The cache must not perform any reference counting. A single | |
7016 | ** call to xUnpin() unpins the page regardless of the number of prior calls | |
7017 | ** to xFetch(). | |
7018 | ** | |
7019 | ** [[the xRekey() page cache methods]] | |
7020 | ** The xRekey() method is used to change the key value associated with the | |
7021 | ** page passed as the second argument. If the cache | |
7022 | ** previously contains an entry associated with newKey, it must be | |
7023 | ** discarded. ^Any prior cache entry associated with newKey is guaranteed not | |
7024 | ** to be pinned. | |
7025 | ** | |
7026 | ** When SQLite calls the xTruncate() method, the cache must discard all | |
7027 | ** existing cache entries with page numbers (keys) greater than or equal | |
7028 | ** to the value of the iLimit parameter passed to xTruncate(). If any | |
7029 | ** of these pages are pinned, they are implicitly unpinned, meaning that | |
7030 | ** they can be safely discarded. | |
7031 | ** | |
7032 | ** [[the xDestroy() page cache method]] | |
7033 | ** ^The xDestroy() method is used to delete a cache allocated by xCreate(). | |
7034 | ** All resources associated with the specified cache should be freed. ^After | |
7035 | ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] | |
7036 | ** handle invalid, and will not use it with any other sqlite3_pcache_methods2 | |
7037 | ** functions. | |
7038 | ** | |
7039 | ** [[the xShrink() page cache method]] | |
7040 | ** ^SQLite invokes the xShrink() method when it wants the page cache to | |
7041 | ** free up as much of heap memory as possible. The page cache implementation | |
7042 | ** is not obligated to free any memory, but well-behaved implementations should | |
7043 | ** do their best. | |
7044 | */ | |
7045 | typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; | |
7046 | struct sqlite3_pcache_methods2 { | |
7047 | int iVersion; | |
7048 | void *pArg; | |
7049 | int (*xInit)(void*); | |
7050 | void (*xShutdown)(void*); | |
7051 | sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); | |
7052 | void (*xCachesize)(sqlite3_pcache*, int nCachesize); | |
7053 | int (*xPagecount)(sqlite3_pcache*); | |
7054 | sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); | |
7055 | void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); | |
7056 | void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, | |
7057 | unsigned oldKey, unsigned newKey); | |
7058 | void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); | |
7059 | void (*xDestroy)(sqlite3_pcache*); | |
7060 | void (*xShrink)(sqlite3_pcache*); | |
7061 | }; | |
7062 | ||
7063 | /* | |
7064 | ** This is the obsolete pcache_methods object that has now been replaced | |
7065 | ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is | |
7066 | ** retained in the header file for backwards compatibility only. | |
7067 | */ | |
7068 | typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; | |
7069 | struct sqlite3_pcache_methods { | |
7070 | void *pArg; | |
7071 | int (*xInit)(void*); | |
7072 | void (*xShutdown)(void*); | |
7073 | sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); | |
7074 | void (*xCachesize)(sqlite3_pcache*, int nCachesize); | |
7075 | int (*xPagecount)(sqlite3_pcache*); | |
7076 | void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); | |
7077 | void (*xUnpin)(sqlite3_pcache*, void*, int discard); | |
7078 | void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); | |
7079 | void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); | |
7080 | void (*xDestroy)(sqlite3_pcache*); | |
7081 | }; | |
7082 | ||
7083 | ||
7084 | /* | |
7085 | ** CAPI3REF: Online Backup Object | |
7086 | ** | |
7087 | ** The sqlite3_backup object records state information about an ongoing | |
7088 | ** online backup operation. ^The sqlite3_backup object is created by | |
7089 | ** a call to [sqlite3_backup_init()] and is destroyed by a call to | |
7090 | ** [sqlite3_backup_finish()]. | |
7091 | ** | |
7092 | ** See Also: [Using the SQLite Online Backup API] | |
7093 | */ | |
7094 | typedef struct sqlite3_backup sqlite3_backup; | |
7095 | ||
7096 | /* | |
7097 | ** CAPI3REF: Online Backup API. | |
7098 | ** | |
7099 | ** The backup API copies the content of one database into another. | |
7100 | ** It is useful either for creating backups of databases or | |
7101 | ** for copying in-memory databases to or from persistent files. | |
7102 | ** | |
7103 | ** See Also: [Using the SQLite Online Backup API] | |
7104 | ** | |
7105 | ** ^SQLite holds a write transaction open on the destination database file | |
7106 | ** for the duration of the backup operation. | |
7107 | ** ^The source database is read-locked only while it is being read; | |
7108 | ** it is not locked continuously for the entire backup operation. | |
7109 | ** ^Thus, the backup may be performed on a live source database without | |
7110 | ** preventing other database connections from | |
7111 | ** reading or writing to the source database while the backup is underway. | |
7112 | ** | |
7113 | ** ^(To perform a backup operation: | |
7114 | ** <ol> | |
7115 | ** <li><b>sqlite3_backup_init()</b> is called once to initialize the | |
7116 | ** backup, | |
7117 | ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer | |
7118 | ** the data between the two databases, and finally | |
7119 | ** <li><b>sqlite3_backup_finish()</b> is called to release all resources | |
7120 | ** associated with the backup operation. | |
7121 | ** </ol>)^ | |
7122 | ** There should be exactly one call to sqlite3_backup_finish() for each | |
7123 | ** successful call to sqlite3_backup_init(). | |
7124 | ** | |
7125 | ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> | |
7126 | ** | |
7127 | ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the | |
7128 | ** [database connection] associated with the destination database | |
7129 | ** and the database name, respectively. | |
7130 | ** ^The database name is "main" for the main database, "temp" for the | |
7131 | ** temporary database, or the name specified after the AS keyword in | |
7132 | ** an [ATTACH] statement for an attached database. | |
7133 | ** ^The S and M arguments passed to | |
7134 | ** sqlite3_backup_init(D,N,S,M) identify the [database connection] | |
7135 | ** and database name of the source database, respectively. | |
7136 | ** ^The source and destination [database connections] (parameters S and D) | |
7137 | ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with | |
7138 | ** an error. | |
7139 | ** | |
7140 | ** ^A call to sqlite3_backup_init() will fail, returning SQLITE_ERROR, if | |
7141 | ** there is already a read or read-write transaction open on the | |
7142 | ** destination database. | |
7143 | ** | |
7144 | ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is | |
7145 | ** returned and an error code and error message are stored in the | |
7146 | ** destination [database connection] D. | |
7147 | ** ^The error code and message for the failed call to sqlite3_backup_init() | |
7148 | ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or | |
7149 | ** [sqlite3_errmsg16()] functions. | |
7150 | ** ^A successful call to sqlite3_backup_init() returns a pointer to an | |
7151 | ** [sqlite3_backup] object. | |
7152 | ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and | |
7153 | ** sqlite3_backup_finish() functions to perform the specified backup | |
7154 | ** operation. | |
7155 | ** | |
7156 | ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> | |
7157 | ** | |
7158 | ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between | |
7159 | ** the source and destination databases specified by [sqlite3_backup] object B. | |
7160 | ** ^If N is negative, all remaining source pages are copied. | |
7161 | ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there | |
7162 | ** are still more pages to be copied, then the function returns [SQLITE_OK]. | |
7163 | ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages | |
7164 | ** from source to destination, then it returns [SQLITE_DONE]. | |
7165 | ** ^If an error occurs while running sqlite3_backup_step(B,N), | |
7166 | ** then an [error code] is returned. ^As well as [SQLITE_OK] and | |
7167 | ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], | |
7168 | ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an | |
7169 | ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. | |
7170 | ** | |
7171 | ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if | |
7172 | ** <ol> | |
7173 | ** <li> the destination database was opened read-only, or | |
7174 | ** <li> the destination database is using write-ahead-log journaling | |
7175 | ** and the destination and source page sizes differ, or | |
7176 | ** <li> the destination database is an in-memory database and the | |
7177 | ** destination and source page sizes differ. | |
7178 | ** </ol>)^ | |
7179 | ** | |
7180 | ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then | |
7181 | ** the [sqlite3_busy_handler | busy-handler function] | |
7182 | ** is invoked (if one is specified). ^If the | |
7183 | ** busy-handler returns non-zero before the lock is available, then | |
7184 | ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to | |
7185 | ** sqlite3_backup_step() can be retried later. ^If the source | |
7186 | ** [database connection] | |
7187 | ** is being used to write to the source database when sqlite3_backup_step() | |
7188 | ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this | |
7189 | ** case the call to sqlite3_backup_step() can be retried later on. ^(If | |
7190 | ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or | |
7191 | ** [SQLITE_READONLY] is returned, then | |
7192 | ** there is no point in retrying the call to sqlite3_backup_step(). These | |
7193 | ** errors are considered fatal.)^ The application must accept | |
7194 | ** that the backup operation has failed and pass the backup operation handle | |
7195 | ** to the sqlite3_backup_finish() to release associated resources. | |
7196 | ** | |
7197 | ** ^The first call to sqlite3_backup_step() obtains an exclusive lock | |
7198 | ** on the destination file. ^The exclusive lock is not released until either | |
7199 | ** sqlite3_backup_finish() is called or the backup operation is complete | |
7200 | ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to | |
7201 | ** sqlite3_backup_step() obtains a [shared lock] on the source database that | |
7202 | ** lasts for the duration of the sqlite3_backup_step() call. | |
7203 | ** ^Because the source database is not locked between calls to | |
7204 | ** sqlite3_backup_step(), the source database may be modified mid-way | |
7205 | ** through the backup process. ^If the source database is modified by an | |
7206 | ** external process or via a database connection other than the one being | |
7207 | ** used by the backup operation, then the backup will be automatically | |
7208 | ** restarted by the next call to sqlite3_backup_step(). ^If the source | |
7209 | ** database is modified by the using the same database connection as is used | |
7210 | ** by the backup operation, then the backup database is automatically | |
7211 | ** updated at the same time. | |
7212 | ** | |
7213 | ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> | |
7214 | ** | |
7215 | ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the | |
7216 | ** application wishes to abandon the backup operation, the application | |
7217 | ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). | |
7218 | ** ^The sqlite3_backup_finish() interfaces releases all | |
7219 | ** resources associated with the [sqlite3_backup] object. | |
7220 | ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any | |
7221 | ** active write-transaction on the destination database is rolled back. | |
7222 | ** The [sqlite3_backup] object is invalid | |
7223 | ** and may not be used following a call to sqlite3_backup_finish(). | |
7224 | ** | |
7225 | ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no | |
7226 | ** sqlite3_backup_step() errors occurred, regardless or whether or not | |
7227 | ** sqlite3_backup_step() completed. | |
7228 | ** ^If an out-of-memory condition or IO error occurred during any prior | |
7229 | ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then | |
7230 | ** sqlite3_backup_finish() returns the corresponding [error code]. | |
7231 | ** | |
7232 | ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() | |
7233 | ** is not a permanent error and does not affect the return value of | |
7234 | ** sqlite3_backup_finish(). | |
7235 | ** | |
7236 | ** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] | |
7237 | ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> | |
7238 | ** | |
7239 | ** ^The sqlite3_backup_remaining() routine returns the number of pages still | |
7240 | ** to be backed up at the conclusion of the most recent sqlite3_backup_step(). | |
7241 | ** ^The sqlite3_backup_pagecount() routine returns the total number of pages | |
7242 | ** in the source database at the conclusion of the most recent | |
7243 | ** sqlite3_backup_step(). | |
7244 | ** ^(The values returned by these functions are only updated by | |
7245 | ** sqlite3_backup_step(). If the source database is modified in a way that | |
7246 | ** changes the size of the source database or the number of pages remaining, | |
7247 | ** those changes are not reflected in the output of sqlite3_backup_pagecount() | |
7248 | ** and sqlite3_backup_remaining() until after the next | |
7249 | ** sqlite3_backup_step().)^ | |
7250 | ** | |
7251 | ** <b>Concurrent Usage of Database Handles</b> | |
7252 | ** | |
7253 | ** ^The source [database connection] may be used by the application for other | |
7254 | ** purposes while a backup operation is underway or being initialized. | |
7255 | ** ^If SQLite is compiled and configured to support threadsafe database | |
7256 | ** connections, then the source database connection may be used concurrently | |
7257 | ** from within other threads. | |
7258 | ** | |
7259 | ** However, the application must guarantee that the destination | |
7260 | ** [database connection] is not passed to any other API (by any thread) after | |
7261 | ** sqlite3_backup_init() is called and before the corresponding call to | |
7262 | ** sqlite3_backup_finish(). SQLite does not currently check to see | |
7263 | ** if the application incorrectly accesses the destination [database connection] | |
7264 | ** and so no error code is reported, but the operations may malfunction | |
7265 | ** nevertheless. Use of the destination database connection while a | |
7266 | ** backup is in progress might also also cause a mutex deadlock. | |
7267 | ** | |
7268 | ** If running in [shared cache mode], the application must | |
7269 | ** guarantee that the shared cache used by the destination database | |
7270 | ** is not accessed while the backup is running. In practice this means | |
7271 | ** that the application must guarantee that the disk file being | |
7272 | ** backed up to is not accessed by any connection within the process, | |
7273 | ** not just the specific connection that was passed to sqlite3_backup_init(). | |
7274 | ** | |
7275 | ** The [sqlite3_backup] object itself is partially threadsafe. Multiple | |
7276 | ** threads may safely make multiple concurrent calls to sqlite3_backup_step(). | |
7277 | ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() | |
7278 | ** APIs are not strictly speaking threadsafe. If they are invoked at the | |
7279 | ** same time as another thread is invoking sqlite3_backup_step() it is | |
7280 | ** possible that they return invalid values. | |
7281 | */ | |
7282 | SQLITE_API sqlite3_backup *SQLITE_STDCALL sqlite3_backup_init( | |
7283 | sqlite3 *pDest, /* Destination database handle */ | |
7284 | const char *zDestName, /* Destination database name */ | |
7285 | sqlite3 *pSource, /* Source database handle */ | |
7286 | const char *zSourceName /* Source database name */ | |
7287 | ); | |
7288 | SQLITE_API int SQLITE_STDCALL sqlite3_backup_step(sqlite3_backup *p, int nPage); | |
7289 | SQLITE_API int SQLITE_STDCALL sqlite3_backup_finish(sqlite3_backup *p); | |
7290 | SQLITE_API int SQLITE_STDCALL sqlite3_backup_remaining(sqlite3_backup *p); | |
7291 | SQLITE_API int SQLITE_STDCALL sqlite3_backup_pagecount(sqlite3_backup *p); | |
7292 | ||
7293 | /* | |
7294 | ** CAPI3REF: Unlock Notification | |
7295 | ** METHOD: sqlite3 | |
7296 | ** | |
7297 | ** ^When running in shared-cache mode, a database operation may fail with | |
7298 | ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or | |
7299 | ** individual tables within the shared-cache cannot be obtained. See | |
7300 | ** [SQLite Shared-Cache Mode] for a description of shared-cache locking. | |
7301 | ** ^This API may be used to register a callback that SQLite will invoke | |
7302 | ** when the connection currently holding the required lock relinquishes it. | |
7303 | ** ^This API is only available if the library was compiled with the | |
7304 | ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. | |
7305 | ** | |
7306 | ** See Also: [Using the SQLite Unlock Notification Feature]. | |
7307 | ** | |
7308 | ** ^Shared-cache locks are released when a database connection concludes | |
7309 | ** its current transaction, either by committing it or rolling it back. | |
7310 | ** | |
7311 | ** ^When a connection (known as the blocked connection) fails to obtain a | |
7312 | ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the | |
7313 | ** identity of the database connection (the blocking connection) that | |
7314 | ** has locked the required resource is stored internally. ^After an | |
7315 | ** application receives an SQLITE_LOCKED error, it may call the | |
7316 | ** sqlite3_unlock_notify() method with the blocked connection handle as | |
7317 | ** the first argument to register for a callback that will be invoked | |
7318 | ** when the blocking connections current transaction is concluded. ^The | |
7319 | ** callback is invoked from within the [sqlite3_step] or [sqlite3_close] | |
7320 | ** call that concludes the blocking connections transaction. | |
7321 | ** | |
7322 | ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, | |
7323 | ** there is a chance that the blocking connection will have already | |
7324 | ** concluded its transaction by the time sqlite3_unlock_notify() is invoked. | |
7325 | ** If this happens, then the specified callback is invoked immediately, | |
7326 | ** from within the call to sqlite3_unlock_notify().)^ | |
7327 | ** | |
7328 | ** ^If the blocked connection is attempting to obtain a write-lock on a | |
7329 | ** shared-cache table, and more than one other connection currently holds | |
7330 | ** a read-lock on the same table, then SQLite arbitrarily selects one of | |
7331 | ** the other connections to use as the blocking connection. | |
7332 | ** | |
7333 | ** ^(There may be at most one unlock-notify callback registered by a | |
7334 | ** blocked connection. If sqlite3_unlock_notify() is called when the | |
7335 | ** blocked connection already has a registered unlock-notify callback, | |
7336 | ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is | |
7337 | ** called with a NULL pointer as its second argument, then any existing | |
7338 | ** unlock-notify callback is canceled. ^The blocked connections | |
7339 | ** unlock-notify callback may also be canceled by closing the blocked | |
7340 | ** connection using [sqlite3_close()]. | |
7341 | ** | |
7342 | ** The unlock-notify callback is not reentrant. If an application invokes | |
7343 | ** any sqlite3_xxx API functions from within an unlock-notify callback, a | |
7344 | ** crash or deadlock may be the result. | |
7345 | ** | |
7346 | ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always | |
7347 | ** returns SQLITE_OK. | |
7348 | ** | |
7349 | ** <b>Callback Invocation Details</b> | |
7350 | ** | |
7351 | ** When an unlock-notify callback is registered, the application provides a | |
7352 | ** single void* pointer that is passed to the callback when it is invoked. | |
7353 | ** However, the signature of the callback function allows SQLite to pass | |
7354 | ** it an array of void* context pointers. The first argument passed to | |
7355 | ** an unlock-notify callback is a pointer to an array of void* pointers, | |
7356 | ** and the second is the number of entries in the array. | |
7357 | ** | |
7358 | ** When a blocking connections transaction is concluded, there may be | |
7359 | ** more than one blocked connection that has registered for an unlock-notify | |
7360 | ** callback. ^If two or more such blocked connections have specified the | |
7361 | ** same callback function, then instead of invoking the callback function | |
7362 | ** multiple times, it is invoked once with the set of void* context pointers | |
7363 | ** specified by the blocked connections bundled together into an array. | |
7364 | ** This gives the application an opportunity to prioritize any actions | |
7365 | ** related to the set of unblocked database connections. | |
7366 | ** | |
7367 | ** <b>Deadlock Detection</b> | |
7368 | ** | |
7369 | ** Assuming that after registering for an unlock-notify callback a | |
7370 | ** database waits for the callback to be issued before taking any further | |
7371 | ** action (a reasonable assumption), then using this API may cause the | |
7372 | ** application to deadlock. For example, if connection X is waiting for | |
7373 | ** connection Y's transaction to be concluded, and similarly connection | |
7374 | ** Y is waiting on connection X's transaction, then neither connection | |
7375 | ** will proceed and the system may remain deadlocked indefinitely. | |
7376 | ** | |
7377 | ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock | |
7378 | ** detection. ^If a given call to sqlite3_unlock_notify() would put the | |
7379 | ** system in a deadlocked state, then SQLITE_LOCKED is returned and no | |
7380 | ** unlock-notify callback is registered. The system is said to be in | |
7381 | ** a deadlocked state if connection A has registered for an unlock-notify | |
7382 | ** callback on the conclusion of connection B's transaction, and connection | |
7383 | ** B has itself registered for an unlock-notify callback when connection | |
7384 | ** A's transaction is concluded. ^Indirect deadlock is also detected, so | |
7385 | ** the system is also considered to be deadlocked if connection B has | |
7386 | ** registered for an unlock-notify callback on the conclusion of connection | |
7387 | ** C's transaction, where connection C is waiting on connection A. ^Any | |
7388 | ** number of levels of indirection are allowed. | |
7389 | ** | |
7390 | ** <b>The "DROP TABLE" Exception</b> | |
7391 | ** | |
7392 | ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost | |
7393 | ** always appropriate to call sqlite3_unlock_notify(). There is however, | |
7394 | ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, | |
7395 | ** SQLite checks if there are any currently executing SELECT statements | |
7396 | ** that belong to the same connection. If there are, SQLITE_LOCKED is | |
7397 | ** returned. In this case there is no "blocking connection", so invoking | |
7398 | ** sqlite3_unlock_notify() results in the unlock-notify callback being | |
7399 | ** invoked immediately. If the application then re-attempts the "DROP TABLE" | |
7400 | ** or "DROP INDEX" query, an infinite loop might be the result. | |
7401 | ** | |
7402 | ** One way around this problem is to check the extended error code returned | |
7403 | ** by an sqlite3_step() call. ^(If there is a blocking connection, then the | |
7404 | ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in | |
7405 | ** the special "DROP TABLE/INDEX" case, the extended error code is just | |
7406 | ** SQLITE_LOCKED.)^ | |
7407 | */ | |
7408 | SQLITE_API int SQLITE_STDCALL sqlite3_unlock_notify( | |
7409 | sqlite3 *pBlocked, /* Waiting connection */ | |
7410 | void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ | |
7411 | void *pNotifyArg /* Argument to pass to xNotify */ | |
7412 | ); | |
5783a860 AC |
7413 | |
7414 | ||
08b809f9 EM |
7415 | /* |
7416 | ** CAPI3REF: String Comparison | |
7417 | ** | |
7418 | ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications | |
7419 | ** and extensions to compare the contents of two buffers containing UTF-8 | |
7420 | ** strings in a case-independent fashion, using the same definition of "case | |
7421 | ** independence" that SQLite uses internally when comparing identifiers. | |
7422 | */ | |
7423 | SQLITE_API int SQLITE_STDCALL sqlite3_stricmp(const char *, const char *); | |
7424 | SQLITE_API int SQLITE_STDCALL sqlite3_strnicmp(const char *, const char *, int); | |
7425 | ||
7426 | /* | |
7427 | ** CAPI3REF: String Globbing | |
7428 | * | |
7429 | ** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if | |
7430 | ** string X matches the [GLOB] pattern P. | |
7431 | ** ^The definition of [GLOB] pattern matching used in | |
7432 | ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the | |
7433 | ** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function | |
7434 | ** is case sensitive. | |
7435 | ** | |
7436 | ** Note that this routine returns zero on a match and non-zero if the strings | |
7437 | ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. | |
7438 | ** | |
7439 | ** See also: [sqlite3_strlike()]. | |
7440 | */ | |
7441 | SQLITE_API int SQLITE_STDCALL sqlite3_strglob(const char *zGlob, const char *zStr); | |
7442 | ||
7443 | /* | |
7444 | ** CAPI3REF: String LIKE Matching | |
7445 | * | |
7446 | ** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if | |
7447 | ** string X matches the [LIKE] pattern P with escape character E. | |
7448 | ** ^The definition of [LIKE] pattern matching used in | |
7449 | ** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" | |
7450 | ** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without | |
7451 | ** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. | |
7452 | ** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case | |
7453 | ** insensitive - equivalent upper and lower case ASCII characters match | |
7454 | ** one another. | |
7455 | ** | |
7456 | ** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though | |
7457 | ** only ASCII characters are case folded. | |
7458 | ** | |
7459 | ** Note that this routine returns zero on a match and non-zero if the strings | |
7460 | ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. | |
7461 | ** | |
7462 | ** See also: [sqlite3_strglob()]. | |
7463 | */ | |
7464 | SQLITE_API int SQLITE_STDCALL sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); | |
7465 | ||
7466 | /* | |
7467 | ** CAPI3REF: Error Logging Interface | |
7468 | ** | |
7469 | ** ^The [sqlite3_log()] interface writes a message into the [error log] | |
7470 | ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. | |
7471 | ** ^If logging is enabled, the zFormat string and subsequent arguments are | |
7472 | ** used with [sqlite3_snprintf()] to generate the final output string. | |
7473 | ** | |
7474 | ** The sqlite3_log() interface is intended for use by extensions such as | |
7475 | ** virtual tables, collating functions, and SQL functions. While there is | |
7476 | ** nothing to prevent an application from calling sqlite3_log(), doing so | |
7477 | ** is considered bad form. | |
7478 | ** | |
7479 | ** The zFormat string must not be NULL. | |
7480 | ** | |
7481 | ** To avoid deadlocks and other threading problems, the sqlite3_log() routine | |
7482 | ** will not use dynamically allocated memory. The log message is stored in | |
7483 | ** a fixed-length buffer on the stack. If the log message is longer than | |
7484 | ** a few hundred characters, it will be truncated to the length of the | |
7485 | ** buffer. | |
7486 | */ | |
7487 | SQLITE_API void SQLITE_CDECL sqlite3_log(int iErrCode, const char *zFormat, ...); | |
7488 | ||
7489 | /* | |
7490 | ** CAPI3REF: Write-Ahead Log Commit Hook | |
7491 | ** METHOD: sqlite3 | |
7492 | ** | |
7493 | ** ^The [sqlite3_wal_hook()] function is used to register a callback that | |
7494 | ** is invoked each time data is committed to a database in wal mode. | |
7495 | ** | |
7496 | ** ^(The callback is invoked by SQLite after the commit has taken place and | |
7497 | ** the associated write-lock on the database released)^, so the implementation | |
7498 | ** may read, write or [checkpoint] the database as required. | |
7499 | ** | |
7500 | ** ^The first parameter passed to the callback function when it is invoked | |
7501 | ** is a copy of the third parameter passed to sqlite3_wal_hook() when | |
7502 | ** registering the callback. ^The second is a copy of the database handle. | |
7503 | ** ^The third parameter is the name of the database that was written to - | |
7504 | ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter | |
7505 | ** is the number of pages currently in the write-ahead log file, | |
7506 | ** including those that were just committed. | |
7507 | ** | |
7508 | ** The callback function should normally return [SQLITE_OK]. ^If an error | |
7509 | ** code is returned, that error will propagate back up through the | |
7510 | ** SQLite code base to cause the statement that provoked the callback | |
7511 | ** to report an error, though the commit will have still occurred. If the | |
7512 | ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value | |
7513 | ** that does not correspond to any valid SQLite error code, the results | |
7514 | ** are undefined. | |
7515 | ** | |
7516 | ** A single database handle may have at most a single write-ahead log callback | |
7517 | ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any | |
7518 | ** previously registered write-ahead log callback. ^Note that the | |
7519 | ** [sqlite3_wal_autocheckpoint()] interface and the | |
7520 | ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will | |
7521 | ** overwrite any prior [sqlite3_wal_hook()] settings. | |
7522 | */ | |
7523 | SQLITE_API void *SQLITE_STDCALL sqlite3_wal_hook( | |
7524 | sqlite3*, | |
7525 | int(*)(void *,sqlite3*,const char*,int), | |
7526 | void* | |
7527 | ); | |
7528 | ||
7529 | /* | |
7530 | ** CAPI3REF: Configure an auto-checkpoint | |
7531 | ** METHOD: sqlite3 | |
7532 | ** | |
7533 | ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around | |
7534 | ** [sqlite3_wal_hook()] that causes any database on [database connection] D | |
7535 | ** to automatically [checkpoint] | |
7536 | ** after committing a transaction if there are N or | |
7537 | ** more frames in the [write-ahead log] file. ^Passing zero or | |
7538 | ** a negative value as the nFrame parameter disables automatic | |
7539 | ** checkpoints entirely. | |
7540 | ** | |
7541 | ** ^The callback registered by this function replaces any existing callback | |
7542 | ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback | |
7543 | ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism | |
7544 | ** configured by this function. | |
7545 | ** | |
7546 | ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface | |
7547 | ** from SQL. | |
7548 | ** | |
7549 | ** ^Checkpoints initiated by this mechanism are | |
7550 | ** [sqlite3_wal_checkpoint_v2|PASSIVE]. | |
7551 | ** | |
7552 | ** ^Every new [database connection] defaults to having the auto-checkpoint | |
7553 | ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] | |
7554 | ** pages. The use of this interface | |
7555 | ** is only necessary if the default setting is found to be suboptimal | |
7556 | ** for a particular application. | |
7557 | */ | |
7558 | SQLITE_API int SQLITE_STDCALL sqlite3_wal_autocheckpoint(sqlite3 *db, int N); | |
7559 | ||
7560 | /* | |
7561 | ** CAPI3REF: Checkpoint a database | |
7562 | ** METHOD: sqlite3 | |
7563 | ** | |
7564 | ** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to | |
7565 | ** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ | |
7566 | ** | |
7567 | ** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the | |
7568 | ** [write-ahead log] for database X on [database connection] D to be | |
7569 | ** transferred into the database file and for the write-ahead log to | |
7570 | ** be reset. See the [checkpointing] documentation for addition | |
7571 | ** information. | |
7572 | ** | |
7573 | ** This interface used to be the only way to cause a checkpoint to | |
7574 | ** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] | |
7575 | ** interface was added. This interface is retained for backwards | |
7576 | ** compatibility and as a convenience for applications that need to manually | |
7577 | ** start a callback but which do not need the full power (and corresponding | |
7578 | ** complication) of [sqlite3_wal_checkpoint_v2()]. | |
7579 | */ | |
7580 | SQLITE_API int SQLITE_STDCALL sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); | |
7581 | ||
7582 | /* | |
7583 | ** CAPI3REF: Checkpoint a database | |
7584 | ** METHOD: sqlite3 | |
7585 | ** | |
7586 | ** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint | |
7587 | ** operation on database X of [database connection] D in mode M. Status | |
7588 | ** information is written back into integers pointed to by L and C.)^ | |
7589 | ** ^(The M parameter must be a valid [checkpoint mode]:)^ | |
7590 | ** | |
7591 | ** <dl> | |
7592 | ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> | |
7593 | ** ^Checkpoint as many frames as possible without waiting for any database | |
7594 | ** readers or writers to finish, then sync the database file if all frames | |
7595 | ** in the log were checkpointed. ^The [busy-handler callback] | |
7596 | ** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. | |
7597 | ** ^On the other hand, passive mode might leave the checkpoint unfinished | |
7598 | ** if there are concurrent readers or writers. | |
7599 | ** | |
7600 | ** <dt>SQLITE_CHECKPOINT_FULL<dd> | |
7601 | ** ^This mode blocks (it invokes the | |
7602 | ** [sqlite3_busy_handler|busy-handler callback]) until there is no | |
7603 | ** database writer and all readers are reading from the most recent database | |
7604 | ** snapshot. ^It then checkpoints all frames in the log file and syncs the | |
7605 | ** database file. ^This mode blocks new database writers while it is pending, | |
7606 | ** but new database readers are allowed to continue unimpeded. | |
7607 | ** | |
7608 | ** <dt>SQLITE_CHECKPOINT_RESTART<dd> | |
7609 | ** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition | |
7610 | ** that after checkpointing the log file it blocks (calls the | |
7611 | ** [busy-handler callback]) | |
7612 | ** until all readers are reading from the database file only. ^This ensures | |
7613 | ** that the next writer will restart the log file from the beginning. | |
7614 | ** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new | |
7615 | ** database writer attempts while it is pending, but does not impede readers. | |
7616 | ** | |
7617 | ** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> | |
7618 | ** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the | |
7619 | ** addition that it also truncates the log file to zero bytes just prior | |
7620 | ** to a successful return. | |
7621 | ** </dl> | |
7622 | ** | |
7623 | ** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in | |
7624 | ** the log file or to -1 if the checkpoint could not run because | |
7625 | ** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not | |
7626 | ** NULL,then *pnCkpt is set to the total number of checkpointed frames in the | |
7627 | ** log file (including any that were already checkpointed before the function | |
7628 | ** was called) or to -1 if the checkpoint could not run due to an error or | |
7629 | ** because the database is not in WAL mode. ^Note that upon successful | |
7630 | ** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been | |
7631 | ** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. | |
7632 | ** | |
7633 | ** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If | |
7634 | ** any other process is running a checkpoint operation at the same time, the | |
7635 | ** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a | |
7636 | ** busy-handler configured, it will not be invoked in this case. | |
7637 | ** | |
7638 | ** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the | |
7639 | ** exclusive "writer" lock on the database file. ^If the writer lock cannot be | |
7640 | ** obtained immediately, and a busy-handler is configured, it is invoked and | |
7641 | ** the writer lock retried until either the busy-handler returns 0 or the lock | |
7642 | ** is successfully obtained. ^The busy-handler is also invoked while waiting for | |
7643 | ** database readers as described above. ^If the busy-handler returns 0 before | |
7644 | ** the writer lock is obtained or while waiting for database readers, the | |
7645 | ** checkpoint operation proceeds from that point in the same way as | |
7646 | ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible | |
7647 | ** without blocking any further. ^SQLITE_BUSY is returned in this case. | |
7648 | ** | |
7649 | ** ^If parameter zDb is NULL or points to a zero length string, then the | |
7650 | ** specified operation is attempted on all WAL databases [attached] to | |
7651 | ** [database connection] db. In this case the | |
7652 | ** values written to output parameters *pnLog and *pnCkpt are undefined. ^If | |
7653 | ** an SQLITE_BUSY error is encountered when processing one or more of the | |
7654 | ** attached WAL databases, the operation is still attempted on any remaining | |
7655 | ** attached databases and SQLITE_BUSY is returned at the end. ^If any other | |
7656 | ** error occurs while processing an attached database, processing is abandoned | |
7657 | ** and the error code is returned to the caller immediately. ^If no error | |
7658 | ** (SQLITE_BUSY or otherwise) is encountered while processing the attached | |
7659 | ** databases, SQLITE_OK is returned. | |
7660 | ** | |
7661 | ** ^If database zDb is the name of an attached database that is not in WAL | |
7662 | ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If | |
7663 | ** zDb is not NULL (or a zero length string) and is not the name of any | |
7664 | ** attached database, SQLITE_ERROR is returned to the caller. | |
7665 | ** | |
7666 | ** ^Unless it returns SQLITE_MISUSE, | |
7667 | ** the sqlite3_wal_checkpoint_v2() interface | |
7668 | ** sets the error information that is queried by | |
7669 | ** [sqlite3_errcode()] and [sqlite3_errmsg()]. | |
7670 | ** | |
7671 | ** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface | |
7672 | ** from SQL. | |
7673 | */ | |
7674 | SQLITE_API int SQLITE_STDCALL sqlite3_wal_checkpoint_v2( | |
7675 | sqlite3 *db, /* Database handle */ | |
7676 | const char *zDb, /* Name of attached database (or NULL) */ | |
7677 | int eMode, /* SQLITE_CHECKPOINT_* value */ | |
7678 | int *pnLog, /* OUT: Size of WAL log in frames */ | |
7679 | int *pnCkpt /* OUT: Total number of frames checkpointed */ | |
7680 | ); | |
7681 | ||
7682 | /* | |
7683 | ** CAPI3REF: Checkpoint Mode Values | |
7684 | ** KEYWORDS: {checkpoint mode} | |
7685 | ** | |
7686 | ** These constants define all valid values for the "checkpoint mode" passed | |
7687 | ** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. | |
7688 | ** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the | |
7689 | ** meaning of each of these checkpoint modes. | |
7690 | */ | |
7691 | #define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ | |
7692 | #define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ | |
7693 | #define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */ | |
7694 | #define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ | |
7695 | ||
7696 | /* | |
7697 | ** CAPI3REF: Virtual Table Interface Configuration | |
7698 | ** | |
7699 | ** This function may be called by either the [xConnect] or [xCreate] method | |
7700 | ** of a [virtual table] implementation to configure | |
7701 | ** various facets of the virtual table interface. | |
7702 | ** | |
7703 | ** If this interface is invoked outside the context of an xConnect or | |
7704 | ** xCreate virtual table method then the behavior is undefined. | |
7705 | ** | |
7706 | ** At present, there is only one option that may be configured using | |
7707 | ** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options | |
7708 | ** may be added in the future. | |
7709 | */ | |
7710 | SQLITE_API int SQLITE_CDECL sqlite3_vtab_config(sqlite3*, int op, ...); | |
7711 | ||
7712 | /* | |
7713 | ** CAPI3REF: Virtual Table Configuration Options | |
7714 | ** | |
7715 | ** These macros define the various options to the | |
7716 | ** [sqlite3_vtab_config()] interface that [virtual table] implementations | |
7717 | ** can use to customize and optimize their behavior. | |
7718 | ** | |
7719 | ** <dl> | |
7720 | ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT | |
7721 | ** <dd>Calls of the form | |
7722 | ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, | |
7723 | ** where X is an integer. If X is zero, then the [virtual table] whose | |
7724 | ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not | |
7725 | ** support constraints. In this configuration (which is the default) if | |
7726 | ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire | |
7727 | ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been | |
7728 | ** specified as part of the users SQL statement, regardless of the actual | |
7729 | ** ON CONFLICT mode specified. | |
7730 | ** | |
7731 | ** If X is non-zero, then the virtual table implementation guarantees | |
7732 | ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before | |
7733 | ** any modifications to internal or persistent data structures have been made. | |
7734 | ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite | |
7735 | ** is able to roll back a statement or database transaction, and abandon | |
7736 | ** or continue processing the current SQL statement as appropriate. | |
7737 | ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns | |
7738 | ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode | |
7739 | ** had been ABORT. | |
7740 | ** | |
7741 | ** Virtual table implementations that are required to handle OR REPLACE | |
7742 | ** must do so within the [xUpdate] method. If a call to the | |
7743 | ** [sqlite3_vtab_on_conflict()] function indicates that the current ON | |
7744 | ** CONFLICT policy is REPLACE, the virtual table implementation should | |
7745 | ** silently replace the appropriate rows within the xUpdate callback and | |
7746 | ** return SQLITE_OK. Or, if this is not possible, it may return | |
7747 | ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT | |
7748 | ** constraint handling. | |
7749 | ** </dl> | |
7750 | */ | |
7751 | #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 | |
7752 | ||
7753 | /* | |
7754 | ** CAPI3REF: Determine The Virtual Table Conflict Policy | |
7755 | ** | |
7756 | ** This function may only be called from within a call to the [xUpdate] method | |
7757 | ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The | |
7758 | ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], | |
7759 | ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode | |
7760 | ** of the SQL statement that triggered the call to the [xUpdate] method of the | |
7761 | ** [virtual table]. | |
7762 | */ | |
7763 | SQLITE_API int SQLITE_STDCALL sqlite3_vtab_on_conflict(sqlite3 *); | |
7764 | ||
7765 | /* | |
7766 | ** CAPI3REF: Conflict resolution modes | |
7767 | ** KEYWORDS: {conflict resolution mode} | |
7768 | ** | |
7769 | ** These constants are returned by [sqlite3_vtab_on_conflict()] to | |
7770 | ** inform a [virtual table] implementation what the [ON CONFLICT] mode | |
7771 | ** is for the SQL statement being evaluated. | |
7772 | ** | |
7773 | ** Note that the [SQLITE_IGNORE] constant is also used as a potential | |
7774 | ** return value from the [sqlite3_set_authorizer()] callback and that | |
7775 | ** [SQLITE_ABORT] is also a [result code]. | |
7776 | */ | |
7777 | #define SQLITE_ROLLBACK 1 | |
7778 | /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ | |
7779 | #define SQLITE_FAIL 3 | |
7780 | /* #define SQLITE_ABORT 4 // Also an error code */ | |
7781 | #define SQLITE_REPLACE 5 | |
7782 | ||
7783 | /* | |
7784 | ** CAPI3REF: Prepared Statement Scan Status Opcodes | |
7785 | ** KEYWORDS: {scanstatus options} | |
7786 | ** | |
7787 | ** The following constants can be used for the T parameter to the | |
7788 | ** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a | |
7789 | ** different metric for sqlite3_stmt_scanstatus() to return. | |
7790 | ** | |
7791 | ** When the value returned to V is a string, space to hold that string is | |
7792 | ** managed by the prepared statement S and will be automatically freed when | |
7793 | ** S is finalized. | |
7794 | ** | |
7795 | ** <dl> | |
7796 | ** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> | |
7797 | ** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be | |
7798 | ** set to the total number of times that the X-th loop has run.</dd> | |
7799 | ** | |
7800 | ** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> | |
7801 | ** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set | |
7802 | ** to the total number of rows examined by all iterations of the X-th loop.</dd> | |
7803 | ** | |
7804 | ** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> | |
7805 | ** <dd>^The "double" variable pointed to by the T parameter will be set to the | |
7806 | ** query planner's estimate for the average number of rows output from each | |
7807 | ** iteration of the X-th loop. If the query planner's estimates was accurate, | |
7808 | ** then this value will approximate the quotient NVISIT/NLOOP and the | |
7809 | ** product of this value for all prior loops with the same SELECTID will | |
7810 | ** be the NLOOP value for the current loop. | |
7811 | ** | |
7812 | ** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> | |
7813 | ** <dd>^The "const char *" variable pointed to by the T parameter will be set | |
7814 | ** to a zero-terminated UTF-8 string containing the name of the index or table | |
7815 | ** used for the X-th loop. | |
7816 | ** | |
7817 | ** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> | |
7818 | ** <dd>^The "const char *" variable pointed to by the T parameter will be set | |
7819 | ** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] | |
7820 | ** description for the X-th loop. | |
7821 | ** | |
7822 | ** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> | |
7823 | ** <dd>^The "int" variable pointed to by the T parameter will be set to the | |
7824 | ** "select-id" for the X-th loop. The select-id identifies which query or | |
7825 | ** subquery the loop is part of. The main query has a select-id of zero. | |
7826 | ** The select-id is the same value as is output in the first column | |
7827 | ** of an [EXPLAIN QUERY PLAN] query. | |
7828 | ** </dl> | |
7829 | */ | |
7830 | #define SQLITE_SCANSTAT_NLOOP 0 | |
7831 | #define SQLITE_SCANSTAT_NVISIT 1 | |
7832 | #define SQLITE_SCANSTAT_EST 2 | |
7833 | #define SQLITE_SCANSTAT_NAME 3 | |
7834 | #define SQLITE_SCANSTAT_EXPLAIN 4 | |
7835 | #define SQLITE_SCANSTAT_SELECTID 5 | |
7836 | ||
7837 | /* | |
7838 | ** CAPI3REF: Prepared Statement Scan Status | |
7839 | ** METHOD: sqlite3_stmt | |
7840 | ** | |
7841 | ** This interface returns information about the predicted and measured | |
7842 | ** performance for pStmt. Advanced applications can use this | |
7843 | ** interface to compare the predicted and the measured performance and | |
7844 | ** issue warnings and/or rerun [ANALYZE] if discrepancies are found. | |
7845 | ** | |
7846 | ** Since this interface is expected to be rarely used, it is only | |
7847 | ** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] | |
7848 | ** compile-time option. | |
7849 | ** | |
7850 | ** The "iScanStatusOp" parameter determines which status information to return. | |
7851 | ** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior | |
7852 | ** of this interface is undefined. | |
7853 | ** ^The requested measurement is written into a variable pointed to by | |
7854 | ** the "pOut" parameter. | |
7855 | ** Parameter "idx" identifies the specific loop to retrieve statistics for. | |
7856 | ** Loops are numbered starting from zero. ^If idx is out of range - less than | |
7857 | ** zero or greater than or equal to the total number of loops used to implement | |
7858 | ** the statement - a non-zero value is returned and the variable that pOut | |
7859 | ** points to is unchanged. | |
7860 | ** | |
7861 | ** ^Statistics might not be available for all loops in all statements. ^In cases | |
7862 | ** where there exist loops with no available statistics, this function behaves | |
7863 | ** as if the loop did not exist - it returns non-zero and leave the variable | |
7864 | ** that pOut points to unchanged. | |
7865 | ** | |
7866 | ** See also: [sqlite3_stmt_scanstatus_reset()] | |
7867 | */ | |
7868 | SQLITE_API int SQLITE_STDCALL sqlite3_stmt_scanstatus( | |
7869 | sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ | |
7870 | int idx, /* Index of loop to report on */ | |
7871 | int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ | |
7872 | void *pOut /* Result written here */ | |
7873 | ); | |
7874 | ||
7875 | /* | |
7876 | ** CAPI3REF: Zero Scan-Status Counters | |
7877 | ** METHOD: sqlite3_stmt | |
7878 | ** | |
7879 | ** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. | |
7880 | ** | |
7881 | ** This API is only available if the library is built with pre-processor | |
7882 | ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. | |
7883 | */ | |
7884 | SQLITE_API void SQLITE_STDCALL sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); | |
7885 | ||
7886 | /* | |
7887 | ** CAPI3REF: Flush caches to disk mid-transaction | |
7888 | ** | |
7889 | ** ^If a write-transaction is open on [database connection] D when the | |
7890 | ** [sqlite3_db_cacheflush(D)] interface invoked, any dirty | |
7891 | ** pages in the pager-cache that are not currently in use are written out | |
7892 | ** to disk. A dirty page may be in use if a database cursor created by an | |
7893 | ** active SQL statement is reading from it, or if it is page 1 of a database | |
7894 | ** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] | |
7895 | ** interface flushes caches for all schemas - "main", "temp", and | |
7896 | ** any [attached] databases. | |
7897 | ** | |
7898 | ** ^If this function needs to obtain extra database locks before dirty pages | |
7899 | ** can be flushed to disk, it does so. ^If those locks cannot be obtained | |
7900 | ** immediately and there is a busy-handler callback configured, it is invoked | |
7901 | ** in the usual manner. ^If the required lock still cannot be obtained, then | |
7902 | ** the database is skipped and an attempt made to flush any dirty pages | |
7903 | ** belonging to the next (if any) database. ^If any databases are skipped | |
7904 | ** because locks cannot be obtained, but no other error occurs, this | |
7905 | ** function returns SQLITE_BUSY. | |
7906 | ** | |
7907 | ** ^If any other error occurs while flushing dirty pages to disk (for | |
7908 | ** example an IO error or out-of-memory condition), then processing is | |
7909 | ** abandoned and an SQLite [error code] is returned to the caller immediately. | |
7910 | ** | |
7911 | ** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. | |
7912 | ** | |
7913 | ** ^This function does not set the database handle error code or message | |
7914 | ** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. | |
7915 | */ | |
7916 | SQLITE_API int SQLITE_STDCALL sqlite3_db_cacheflush(sqlite3*); | |
7917 | ||
7918 | /* | |
7919 | ** CAPI3REF: Low-level system error code | |
7920 | ** | |
7921 | ** ^Attempt to return the underlying operating system error code or error | |
7922 | ** number that caused the most reason I/O error or failure to open a file. | |
7923 | ** The return value is OS-dependent. For example, on unix systems, after | |
7924 | ** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be | |
7925 | ** called to get back the underlying "errno" that caused the problem, such | |
7926 | ** as ENOSPC, EAUTH, EISDIR, and so forth. | |
7927 | */ | |
7928 | SQLITE_API int SQLITE_STDCALL sqlite3_system_errno(sqlite3*); | |
7929 | ||
7930 | /* | |
7931 | ** CAPI3REF: Database Snapshot | |
7932 | ** KEYWORDS: {snapshot} | |
7933 | ** EXPERIMENTAL | |
7934 | ** | |
7935 | ** An instance of the snapshot object records the state of a [WAL mode] | |
7936 | ** database for some specific point in history. | |
7937 | ** | |
7938 | ** In [WAL mode], multiple [database connections] that are open on the | |
7939 | ** same database file can each be reading a different historical version | |
7940 | ** of the database file. When a [database connection] begins a read | |
7941 | ** transaction, that connection sees an unchanging copy of the database | |
7942 | ** as it existed for the point in time when the transaction first started. | |
7943 | ** Subsequent changes to the database from other connections are not seen | |
7944 | ** by the reader until a new read transaction is started. | |
7945 | ** | |
7946 | ** The sqlite3_snapshot object records state information about an historical | |
7947 | ** version of the database file so that it is possible to later open a new read | |
7948 | ** transaction that sees that historical version of the database rather than | |
7949 | ** the most recent version. | |
7950 | ** | |
7951 | ** The constructor for this object is [sqlite3_snapshot_get()]. The | |
7952 | ** [sqlite3_snapshot_open()] method causes a fresh read transaction to refer | |
7953 | ** to an historical snapshot (if possible). The destructor for | |
7954 | ** sqlite3_snapshot objects is [sqlite3_snapshot_free()]. | |
7955 | */ | |
7956 | typedef struct sqlite3_snapshot sqlite3_snapshot; | |
7957 | ||
7958 | /* | |
7959 | ** CAPI3REF: Record A Database Snapshot | |
7960 | ** EXPERIMENTAL | |
7961 | ** | |
7962 | ** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a | |
7963 | ** new [sqlite3_snapshot] object that records the current state of | |
7964 | ** schema S in database connection D. ^On success, the | |
7965 | ** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly | |
7966 | ** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. | |
7967 | ** ^If schema S of [database connection] D is not a [WAL mode] database | |
7968 | ** that is in a read transaction, then [sqlite3_snapshot_get(D,S,P)] | |
7969 | ** leaves the *P value unchanged and returns an appropriate [error code]. | |
7970 | ** | |
7971 | ** The [sqlite3_snapshot] object returned from a successful call to | |
7972 | ** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] | |
7973 | ** to avoid a memory leak. | |
7974 | ** | |
7975 | ** The [sqlite3_snapshot_get()] interface is only available when the | |
7976 | ** SQLITE_ENABLE_SNAPSHOT compile-time option is used. | |
7977 | */ | |
7978 | SQLITE_API SQLITE_EXPERIMENTAL int SQLITE_STDCALL sqlite3_snapshot_get( | |
7979 | sqlite3 *db, | |
7980 | const char *zSchema, | |
7981 | sqlite3_snapshot **ppSnapshot | |
7982 | ); | |
7983 | ||
7984 | /* | |
7985 | ** CAPI3REF: Start a read transaction on an historical snapshot | |
7986 | ** EXPERIMENTAL | |
7987 | ** | |
7988 | ** ^The [sqlite3_snapshot_open(D,S,P)] interface attempts to move the | |
7989 | ** read transaction that is currently open on schema S of | |
7990 | ** [database connection] D so that it refers to historical [snapshot] P. | |
7991 | ** ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK on success | |
7992 | ** or an appropriate [error code] if it fails. | |
7993 | ** | |
7994 | ** ^In order to succeed, a call to [sqlite3_snapshot_open(D,S,P)] must be | |
7995 | ** the first operation, apart from other sqlite3_snapshot_open() calls, | |
7996 | ** following the [BEGIN] that starts a new read transaction. | |
7997 | ** ^A [snapshot] will fail to open if it has been overwritten by a | |
7998 | ** [checkpoint]. | |
7999 | ** ^A [snapshot] will fail to open if the database connection D has not | |
8000 | ** previously completed at least one read operation against the database | |
8001 | ** file. (Hint: Run "[PRAGMA application_id]" against a newly opened | |
8002 | ** database connection in order to make it ready to use snapshots.) | |
8003 | ** | |
8004 | ** The [sqlite3_snapshot_open()] interface is only available when the | |
8005 | ** SQLITE_ENABLE_SNAPSHOT compile-time option is used. | |
8006 | */ | |
8007 | SQLITE_API SQLITE_EXPERIMENTAL int SQLITE_STDCALL sqlite3_snapshot_open( | |
8008 | sqlite3 *db, | |
8009 | const char *zSchema, | |
8010 | sqlite3_snapshot *pSnapshot | |
8011 | ); | |
8012 | ||
8013 | /* | |
8014 | ** CAPI3REF: Destroy a snapshot | |
8015 | ** EXPERIMENTAL | |
8016 | ** | |
8017 | ** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. | |
8018 | ** The application must eventually free every [sqlite3_snapshot] object | |
8019 | ** using this routine to avoid a memory leak. | |
8020 | ** | |
8021 | ** The [sqlite3_snapshot_free()] interface is only available when the | |
8022 | ** SQLITE_ENABLE_SNAPSHOT compile-time option is used. | |
8023 | */ | |
8024 | SQLITE_API SQLITE_EXPERIMENTAL void SQLITE_STDCALL sqlite3_snapshot_free(sqlite3_snapshot*); | |
8025 | ||
5783a860 AC |
8026 | /* |
8027 | ** Undo the hack that converts floating point types to integer for | |
8028 | ** builds on processors without floating point support. | |
8029 | */ | |
8030 | #ifdef SQLITE_OMIT_FLOATING_POINT | |
8031 | # undef double | |
8032 | #endif | |
8033 | ||
8034 | #ifdef __cplusplus | |
8035 | } /* End of the 'extern "C"' block */ | |
8036 | #endif | |
08b809f9 EM |
8037 | #endif /* _SQLITE3_H_ */ |
8038 | ||
8039 | /* | |
8040 | ** 2010 August 30 | |
8041 | ** | |
8042 | ** The author disclaims copyright to this source code. In place of | |
8043 | ** a legal notice, here is a blessing: | |
8044 | ** | |
8045 | ** May you do good and not evil. | |
8046 | ** May you find forgiveness for yourself and forgive others. | |
8047 | ** May you share freely, never taking more than you give. | |
8048 | ** | |
8049 | ************************************************************************* | |
8050 | */ | |
8051 | ||
8052 | #ifndef _SQLITE3RTREE_H_ | |
8053 | #define _SQLITE3RTREE_H_ | |
8054 | ||
8055 | ||
8056 | #ifdef __cplusplus | |
8057 | extern "C" { | |
8058 | #endif | |
8059 | ||
8060 | typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; | |
8061 | typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info; | |
8062 | ||
8063 | /* The double-precision datatype used by RTree depends on the | |
8064 | ** SQLITE_RTREE_INT_ONLY compile-time option. | |
8065 | */ | |
8066 | #ifdef SQLITE_RTREE_INT_ONLY | |
8067 | typedef sqlite3_int64 sqlite3_rtree_dbl; | |
8068 | #else | |
8069 | typedef double sqlite3_rtree_dbl; | |
5783a860 | 8070 | #endif |
08b809f9 EM |
8071 | |
8072 | /* | |
8073 | ** Register a geometry callback named zGeom that can be used as part of an | |
8074 | ** R-Tree geometry query as follows: | |
8075 | ** | |
8076 | ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) | |
8077 | */ | |
8078 | SQLITE_API int SQLITE_STDCALL sqlite3_rtree_geometry_callback( | |
8079 | sqlite3 *db, | |
8080 | const char *zGeom, | |
8081 | int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*), | |
8082 | void *pContext | |
8083 | ); | |
8084 | ||
8085 | ||
8086 | /* | |
8087 | ** A pointer to a structure of the following type is passed as the first | |
8088 | ** argument to callbacks registered using rtree_geometry_callback(). | |
8089 | */ | |
8090 | struct sqlite3_rtree_geometry { | |
8091 | void *pContext; /* Copy of pContext passed to s_r_g_c() */ | |
8092 | int nParam; /* Size of array aParam[] */ | |
8093 | sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */ | |
8094 | void *pUser; /* Callback implementation user data */ | |
8095 | void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ | |
8096 | }; | |
8097 | ||
8098 | /* | |
8099 | ** Register a 2nd-generation geometry callback named zScore that can be | |
8100 | ** used as part of an R-Tree geometry query as follows: | |
8101 | ** | |
8102 | ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...) | |
8103 | */ | |
8104 | SQLITE_API int SQLITE_STDCALL sqlite3_rtree_query_callback( | |
8105 | sqlite3 *db, | |
8106 | const char *zQueryFunc, | |
8107 | int (*xQueryFunc)(sqlite3_rtree_query_info*), | |
8108 | void *pContext, | |
8109 | void (*xDestructor)(void*) | |
8110 | ); | |
8111 | ||
8112 | ||
8113 | /* | |
8114 | ** A pointer to a structure of the following type is passed as the | |
8115 | ** argument to scored geometry callback registered using | |
8116 | ** sqlite3_rtree_query_callback(). | |
8117 | ** | |
8118 | ** Note that the first 5 fields of this structure are identical to | |
8119 | ** sqlite3_rtree_geometry. This structure is a subclass of | |
8120 | ** sqlite3_rtree_geometry. | |
8121 | */ | |
8122 | struct sqlite3_rtree_query_info { | |
8123 | void *pContext; /* pContext from when function registered */ | |
8124 | int nParam; /* Number of function parameters */ | |
8125 | sqlite3_rtree_dbl *aParam; /* value of function parameters */ | |
8126 | void *pUser; /* callback can use this, if desired */ | |
8127 | void (*xDelUser)(void*); /* function to free pUser */ | |
8128 | sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */ | |
8129 | unsigned int *anQueue; /* Number of pending entries in the queue */ | |
8130 | int nCoord; /* Number of coordinates */ | |
8131 | int iLevel; /* Level of current node or entry */ | |
8132 | int mxLevel; /* The largest iLevel value in the tree */ | |
8133 | sqlite3_int64 iRowid; /* Rowid for current entry */ | |
8134 | sqlite3_rtree_dbl rParentScore; /* Score of parent node */ | |
8135 | int eParentWithin; /* Visibility of parent node */ | |
8136 | int eWithin; /* OUT: Visiblity */ | |
8137 | sqlite3_rtree_dbl rScore; /* OUT: Write the score here */ | |
8138 | /* The following fields are only available in 3.8.11 and later */ | |
8139 | sqlite3_value **apSqlParam; /* Original SQL values of parameters */ | |
8140 | }; | |
8141 | ||
8142 | /* | |
8143 | ** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin. | |
8144 | */ | |
8145 | #define NOT_WITHIN 0 /* Object completely outside of query region */ | |
8146 | #define PARTLY_WITHIN 1 /* Object partially overlaps query region */ | |
8147 | #define FULLY_WITHIN 2 /* Object fully contained within query region */ | |
8148 | ||
8149 | ||
8150 | #ifdef __cplusplus | |
8151 | } /* end of the 'extern "C"' block */ | |
8152 | #endif | |
8153 | ||
8154 | #endif /* ifndef _SQLITE3RTREE_H_ */ | |
8155 | ||
8156 | /* | |
8157 | ** 2014 May 31 | |
8158 | ** | |
8159 | ** The author disclaims copyright to this source code. In place of | |
8160 | ** a legal notice, here is a blessing: | |
8161 | ** | |
8162 | ** May you do good and not evil. | |
8163 | ** May you find forgiveness for yourself and forgive others. | |
8164 | ** May you share freely, never taking more than you give. | |
8165 | ** | |
8166 | ****************************************************************************** | |
8167 | ** | |
8168 | ** Interfaces to extend FTS5. Using the interfaces defined in this file, | |
8169 | ** FTS5 may be extended with: | |
8170 | ** | |
8171 | ** * custom tokenizers, and | |
8172 | ** * custom auxiliary functions. | |
8173 | */ | |
8174 | ||
8175 | ||
8176 | #ifndef _FTS5_H | |
8177 | #define _FTS5_H | |
8178 | ||
8179 | ||
8180 | #ifdef __cplusplus | |
8181 | extern "C" { | |
8182 | #endif | |
8183 | ||
8184 | /************************************************************************* | |
8185 | ** CUSTOM AUXILIARY FUNCTIONS | |
8186 | ** | |
8187 | ** Virtual table implementations may overload SQL functions by implementing | |
8188 | ** the sqlite3_module.xFindFunction() method. | |
8189 | */ | |
8190 | ||
8191 | typedef struct Fts5ExtensionApi Fts5ExtensionApi; | |
8192 | typedef struct Fts5Context Fts5Context; | |
8193 | typedef struct Fts5PhraseIter Fts5PhraseIter; | |
8194 | ||
8195 | typedef void (*fts5_extension_function)( | |
8196 | const Fts5ExtensionApi *pApi, /* API offered by current FTS version */ | |
8197 | Fts5Context *pFts, /* First arg to pass to pApi functions */ | |
8198 | sqlite3_context *pCtx, /* Context for returning result/error */ | |
8199 | int nVal, /* Number of values in apVal[] array */ | |
8200 | sqlite3_value **apVal /* Array of trailing arguments */ | |
8201 | ); | |
8202 | ||
8203 | struct Fts5PhraseIter { | |
8204 | const unsigned char *a; | |
8205 | const unsigned char *b; | |
8206 | }; | |
8207 | ||
8208 | /* | |
8209 | ** EXTENSION API FUNCTIONS | |
8210 | ** | |
8211 | ** xUserData(pFts): | |
8212 | ** Return a copy of the context pointer the extension function was | |
8213 | ** registered with. | |
8214 | ** | |
8215 | ** xColumnTotalSize(pFts, iCol, pnToken): | |
8216 | ** If parameter iCol is less than zero, set output variable *pnToken | |
8217 | ** to the total number of tokens in the FTS5 table. Or, if iCol is | |
8218 | ** non-negative but less than the number of columns in the table, return | |
8219 | ** the total number of tokens in column iCol, considering all rows in | |
8220 | ** the FTS5 table. | |
8221 | ** | |
8222 | ** If parameter iCol is greater than or equal to the number of columns | |
8223 | ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. | |
8224 | ** an OOM condition or IO error), an appropriate SQLite error code is | |
8225 | ** returned. | |
8226 | ** | |
8227 | ** xColumnCount(pFts): | |
8228 | ** Return the number of columns in the table. | |
8229 | ** | |
8230 | ** xColumnSize(pFts, iCol, pnToken): | |
8231 | ** If parameter iCol is less than zero, set output variable *pnToken | |
8232 | ** to the total number of tokens in the current row. Or, if iCol is | |
8233 | ** non-negative but less than the number of columns in the table, set | |
8234 | ** *pnToken to the number of tokens in column iCol of the current row. | |
8235 | ** | |
8236 | ** If parameter iCol is greater than or equal to the number of columns | |
8237 | ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. | |
8238 | ** an OOM condition or IO error), an appropriate SQLite error code is | |
8239 | ** returned. | |
8240 | ** | |
8241 | ** This function may be quite inefficient if used with an FTS5 table | |
8242 | ** created with the "columnsize=0" option. | |
8243 | ** | |
8244 | ** xColumnText: | |
8245 | ** This function attempts to retrieve the text of column iCol of the | |
8246 | ** current document. If successful, (*pz) is set to point to a buffer | |
8247 | ** containing the text in utf-8 encoding, (*pn) is set to the size in bytes | |
8248 | ** (not characters) of the buffer and SQLITE_OK is returned. Otherwise, | |
8249 | ** if an error occurs, an SQLite error code is returned and the final values | |
8250 | ** of (*pz) and (*pn) are undefined. | |
8251 | ** | |
8252 | ** xPhraseCount: | |
8253 | ** Returns the number of phrases in the current query expression. | |
8254 | ** | |
8255 | ** xPhraseSize: | |
8256 | ** Returns the number of tokens in phrase iPhrase of the query. Phrases | |
8257 | ** are numbered starting from zero. | |
8258 | ** | |
8259 | ** xInstCount: | |
8260 | ** Set *pnInst to the total number of occurrences of all phrases within | |
8261 | ** the query within the current row. Return SQLITE_OK if successful, or | |
8262 | ** an error code (i.e. SQLITE_NOMEM) if an error occurs. | |
8263 | ** | |
8264 | ** This API can be quite slow if used with an FTS5 table created with the | |
8265 | ** "detail=none" or "detail=column" option. If the FTS5 table is created | |
8266 | ** with either "detail=none" or "detail=column" and "content=" option | |
8267 | ** (i.e. if it is a contentless table), then this API always returns 0. | |
8268 | ** | |
8269 | ** xInst: | |
8270 | ** Query for the details of phrase match iIdx within the current row. | |
8271 | ** Phrase matches are numbered starting from zero, so the iIdx argument | |
8272 | ** should be greater than or equal to zero and smaller than the value | |
8273 | ** output by xInstCount(). | |
8274 | ** | |
8275 | ** Usually, output parameter *piPhrase is set to the phrase number, *piCol | |
8276 | ** to the column in which it occurs and *piOff the token offset of the | |
8277 | ** first token of the phrase. The exception is if the table was created | |
8278 | ** with the offsets=0 option specified. In this case *piOff is always | |
8279 | ** set to -1. | |
8280 | ** | |
8281 | ** Returns SQLITE_OK if successful, or an error code (i.e. SQLITE_NOMEM) | |
8282 | ** if an error occurs. | |
8283 | ** | |
8284 | ** This API can be quite slow if used with an FTS5 table created with the | |
8285 | ** "detail=none" or "detail=column" option. | |
8286 | ** | |
8287 | ** xRowid: | |
8288 | ** Returns the rowid of the current row. | |
8289 | ** | |
8290 | ** xTokenize: | |
8291 | ** Tokenize text using the tokenizer belonging to the FTS5 table. | |
8292 | ** | |
8293 | ** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback): | |
8294 | ** This API function is used to query the FTS table for phrase iPhrase | |
8295 | ** of the current query. Specifically, a query equivalent to: | |
8296 | ** | |
8297 | ** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid | |
8298 | ** | |
8299 | ** with $p set to a phrase equivalent to the phrase iPhrase of the | |
8300 | ** current query is executed. For each row visited, the callback function | |
8301 | ** passed as the fourth argument is invoked. The context and API objects | |
8302 | ** passed to the callback function may be used to access the properties of | |
8303 | ** each matched row. Invoking Api.xUserData() returns a copy of the pointer | |
8304 | ** passed as the third argument to pUserData. | |
8305 | ** | |
8306 | ** If the callback function returns any value other than SQLITE_OK, the | |
8307 | ** query is abandoned and the xQueryPhrase function returns immediately. | |
8308 | ** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK. | |
8309 | ** Otherwise, the error code is propagated upwards. | |
8310 | ** | |
8311 | ** If the query runs to completion without incident, SQLITE_OK is returned. | |
8312 | ** Or, if some error occurs before the query completes or is aborted by | |
8313 | ** the callback, an SQLite error code is returned. | |
8314 | ** | |
8315 | ** | |
8316 | ** xSetAuxdata(pFts5, pAux, xDelete) | |
8317 | ** | |
8318 | ** Save the pointer passed as the second argument as the extension functions | |
8319 | ** "auxiliary data". The pointer may then be retrieved by the current or any | |
8320 | ** future invocation of the same fts5 extension function made as part of | |
8321 | ** of the same MATCH query using the xGetAuxdata() API. | |
8322 | ** | |
8323 | ** Each extension function is allocated a single auxiliary data slot for | |
8324 | ** each FTS query (MATCH expression). If the extension function is invoked | |
8325 | ** more than once for a single FTS query, then all invocations share a | |
8326 | ** single auxiliary data context. | |
8327 | ** | |
8328 | ** If there is already an auxiliary data pointer when this function is | |
8329 | ** invoked, then it is replaced by the new pointer. If an xDelete callback | |
8330 | ** was specified along with the original pointer, it is invoked at this | |
8331 | ** point. | |
8332 | ** | |
8333 | ** The xDelete callback, if one is specified, is also invoked on the | |
8334 | ** auxiliary data pointer after the FTS5 query has finished. | |
8335 | ** | |
8336 | ** If an error (e.g. an OOM condition) occurs within this function, an | |
8337 | ** the auxiliary data is set to NULL and an error code returned. If the | |
8338 | ** xDelete parameter was not NULL, it is invoked on the auxiliary data | |
8339 | ** pointer before returning. | |
8340 | ** | |
8341 | ** | |
8342 | ** xGetAuxdata(pFts5, bClear) | |
8343 | ** | |
8344 | ** Returns the current auxiliary data pointer for the fts5 extension | |
8345 | ** function. See the xSetAuxdata() method for details. | |
8346 | ** | |
8347 | ** If the bClear argument is non-zero, then the auxiliary data is cleared | |
8348 | ** (set to NULL) before this function returns. In this case the xDelete, | |
8349 | ** if any, is not invoked. | |
8350 | ** | |
8351 | ** | |
8352 | ** xRowCount(pFts5, pnRow) | |
8353 | ** | |
8354 | ** This function is used to retrieve the total number of rows in the table. | |
8355 | ** In other words, the same value that would be returned by: | |
8356 | ** | |
8357 | ** SELECT count(*) FROM ftstable; | |
8358 | ** | |
8359 | ** xPhraseFirst() | |
8360 | ** This function is used, along with type Fts5PhraseIter and the xPhraseNext | |
8361 | ** method, to iterate through all instances of a single query phrase within | |
8362 | ** the current row. This is the same information as is accessible via the | |
8363 | ** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient | |
8364 | ** to use, this API may be faster under some circumstances. To iterate | |
8365 | ** through instances of phrase iPhrase, use the following code: | |
8366 | ** | |
8367 | ** Fts5PhraseIter iter; | |
8368 | ** int iCol, iOff; | |
8369 | ** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff); | |
8370 | ** iCol>=0; | |
8371 | ** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff) | |
8372 | ** ){ | |
8373 | ** // An instance of phrase iPhrase at offset iOff of column iCol | |
8374 | ** } | |
8375 | ** | |
8376 | ** The Fts5PhraseIter structure is defined above. Applications should not | |
8377 | ** modify this structure directly - it should only be used as shown above | |
8378 | ** with the xPhraseFirst() and xPhraseNext() API methods (and by | |
8379 | ** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below). | |
8380 | ** | |
8381 | ** This API can be quite slow if used with an FTS5 table created with the | |
8382 | ** "detail=none" or "detail=column" option. If the FTS5 table is created | |
8383 | ** with either "detail=none" or "detail=column" and "content=" option | |
8384 | ** (i.e. if it is a contentless table), then this API always iterates | |
8385 | ** through an empty set (all calls to xPhraseFirst() set iCol to -1). | |
8386 | ** | |
8387 | ** xPhraseNext() | |
8388 | ** See xPhraseFirst above. | |
8389 | ** | |
8390 | ** xPhraseFirstColumn() | |
8391 | ** This function and xPhraseNextColumn() are similar to the xPhraseFirst() | |
8392 | ** and xPhraseNext() APIs described above. The difference is that instead | |
8393 | ** of iterating through all instances of a phrase in the current row, these | |
8394 | ** APIs are used to iterate through the set of columns in the current row | |
8395 | ** that contain one or more instances of a specified phrase. For example: | |
8396 | ** | |
8397 | ** Fts5PhraseIter iter; | |
8398 | ** int iCol; | |
8399 | ** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol); | |
8400 | ** iCol>=0; | |
8401 | ** pApi->xPhraseNextColumn(pFts, &iter, &iCol) | |
8402 | ** ){ | |
8403 | ** // Column iCol contains at least one instance of phrase iPhrase | |
8404 | ** } | |
8405 | ** | |
8406 | ** This API can be quite slow if used with an FTS5 table created with the | |
8407 | ** "detail=none" option. If the FTS5 table is created with either | |
8408 | ** "detail=none" "content=" option (i.e. if it is a contentless table), | |
8409 | ** then this API always iterates through an empty set (all calls to | |
8410 | ** xPhraseFirstColumn() set iCol to -1). | |
8411 | ** | |
8412 | ** The information accessed using this API and its companion | |
8413 | ** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext | |
8414 | ** (or xInst/xInstCount). The chief advantage of this API is that it is | |
8415 | ** significantly more efficient than those alternatives when used with | |
8416 | ** "detail=column" tables. | |
8417 | ** | |
8418 | ** xPhraseNextColumn() | |
8419 | ** See xPhraseFirstColumn above. | |
8420 | */ | |
8421 | struct Fts5ExtensionApi { | |
8422 | int iVersion; /* Currently always set to 3 */ | |
8423 | ||
8424 | void *(*xUserData)(Fts5Context*); | |
8425 | ||
8426 | int (*xColumnCount)(Fts5Context*); | |
8427 | int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow); | |
8428 | int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken); | |
8429 | ||
8430 | int (*xTokenize)(Fts5Context*, | |
8431 | const char *pText, int nText, /* Text to tokenize */ | |
8432 | void *pCtx, /* Context passed to xToken() */ | |
8433 | int (*xToken)(void*, int, const char*, int, int, int) /* Callback */ | |
8434 | ); | |
8435 | ||
8436 | int (*xPhraseCount)(Fts5Context*); | |
8437 | int (*xPhraseSize)(Fts5Context*, int iPhrase); | |
8438 | ||
8439 | int (*xInstCount)(Fts5Context*, int *pnInst); | |
8440 | int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff); | |
8441 | ||
8442 | sqlite3_int64 (*xRowid)(Fts5Context*); | |
8443 | int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn); | |
8444 | int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken); | |
8445 | ||
8446 | int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData, | |
8447 | int(*)(const Fts5ExtensionApi*,Fts5Context*,void*) | |
8448 | ); | |
8449 | int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*)); | |
8450 | void *(*xGetAuxdata)(Fts5Context*, int bClear); | |
8451 | ||
8452 | int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*); | |
8453 | void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff); | |
8454 | ||
8455 | int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*); | |
8456 | void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol); | |
8457 | }; | |
8458 | ||
8459 | /* | |
8460 | ** CUSTOM AUXILIARY FUNCTIONS | |
8461 | *************************************************************************/ | |
8462 | ||
8463 | /************************************************************************* | |
8464 | ** CUSTOM TOKENIZERS | |
8465 | ** | |
8466 | ** Applications may also register custom tokenizer types. A tokenizer | |
8467 | ** is registered by providing fts5 with a populated instance of the | |
8468 | ** following structure. All structure methods must be defined, setting | |
8469 | ** any member of the fts5_tokenizer struct to NULL leads to undefined | |
8470 | ** behaviour. The structure methods are expected to function as follows: | |
8471 | ** | |
8472 | ** xCreate: | |
8473 | ** This function is used to allocate and inititalize a tokenizer instance. | |
8474 | ** A tokenizer instance is required to actually tokenize text. | |
8475 | ** | |
8476 | ** The first argument passed to this function is a copy of the (void*) | |
8477 | ** pointer provided by the application when the fts5_tokenizer object | |
8478 | ** was registered with FTS5 (the third argument to xCreateTokenizer()). | |
8479 | ** The second and third arguments are an array of nul-terminated strings | |
8480 | ** containing the tokenizer arguments, if any, specified following the | |
8481 | ** tokenizer name as part of the CREATE VIRTUAL TABLE statement used | |
8482 | ** to create the FTS5 table. | |
8483 | ** | |
8484 | ** The final argument is an output variable. If successful, (*ppOut) | |
8485 | ** should be set to point to the new tokenizer handle and SQLITE_OK | |
8486 | ** returned. If an error occurs, some value other than SQLITE_OK should | |
8487 | ** be returned. In this case, fts5 assumes that the final value of *ppOut | |
8488 | ** is undefined. | |
8489 | ** | |
8490 | ** xDelete: | |
8491 | ** This function is invoked to delete a tokenizer handle previously | |
8492 | ** allocated using xCreate(). Fts5 guarantees that this function will | |
8493 | ** be invoked exactly once for each successful call to xCreate(). | |
8494 | ** | |
8495 | ** xTokenize: | |
8496 | ** This function is expected to tokenize the nText byte string indicated | |
8497 | ** by argument pText. pText may or may not be nul-terminated. The first | |
8498 | ** argument passed to this function is a pointer to an Fts5Tokenizer object | |
8499 | ** returned by an earlier call to xCreate(). | |
8500 | ** | |
8501 | ** The second argument indicates the reason that FTS5 is requesting | |
8502 | ** tokenization of the supplied text. This is always one of the following | |
8503 | ** four values: | |
8504 | ** | |
8505 | ** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into | |
8506 | ** or removed from the FTS table. The tokenizer is being invoked to | |
8507 | ** determine the set of tokens to add to (or delete from) the | |
8508 | ** FTS index. | |
8509 | ** | |
8510 | ** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed | |
8511 | ** against the FTS index. The tokenizer is being called to tokenize | |
8512 | ** a bareword or quoted string specified as part of the query. | |
8513 | ** | |
8514 | ** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as | |
8515 | ** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is | |
8516 | ** followed by a "*" character, indicating that the last token | |
8517 | ** returned by the tokenizer will be treated as a token prefix. | |
8518 | ** | |
8519 | ** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to | |
8520 | ** satisfy an fts5_api.xTokenize() request made by an auxiliary | |
8521 | ** function. Or an fts5_api.xColumnSize() request made by the same | |
8522 | ** on a columnsize=0 database. | |
8523 | ** </ul> | |
8524 | ** | |
8525 | ** For each token in the input string, the supplied callback xToken() must | |
8526 | ** be invoked. The first argument to it should be a copy of the pointer | |
8527 | ** passed as the second argument to xTokenize(). The third and fourth | |
8528 | ** arguments are a pointer to a buffer containing the token text, and the | |
8529 | ** size of the token in bytes. The 4th and 5th arguments are the byte offsets | |
8530 | ** of the first byte of and first byte immediately following the text from | |
8531 | ** which the token is derived within the input. | |
8532 | ** | |
8533 | ** The second argument passed to the xToken() callback ("tflags") should | |
8534 | ** normally be set to 0. The exception is if the tokenizer supports | |
8535 | ** synonyms. In this case see the discussion below for details. | |
8536 | ** | |
8537 | ** FTS5 assumes the xToken() callback is invoked for each token in the | |
8538 | ** order that they occur within the input text. | |
8539 | ** | |
8540 | ** If an xToken() callback returns any value other than SQLITE_OK, then | |
8541 | ** the tokenization should be abandoned and the xTokenize() method should | |
8542 | ** immediately return a copy of the xToken() return value. Or, if the | |
8543 | ** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally, | |
8544 | ** if an error occurs with the xTokenize() implementation itself, it | |
8545 | ** may abandon the tokenization and return any error code other than | |
8546 | ** SQLITE_OK or SQLITE_DONE. | |
8547 | ** | |
8548 | ** SYNONYM SUPPORT | |
8549 | ** | |
8550 | ** Custom tokenizers may also support synonyms. Consider a case in which a | |
8551 | ** user wishes to query for a phrase such as "first place". Using the | |
8552 | ** built-in tokenizers, the FTS5 query 'first + place' will match instances | |
8553 | ** of "first place" within the document set, but not alternative forms | |
8554 | ** such as "1st place". In some applications, it would be better to match | |
8555 | ** all instances of "first place" or "1st place" regardless of which form | |
8556 | ** the user specified in the MATCH query text. | |
8557 | ** | |
8558 | ** There are several ways to approach this in FTS5: | |
8559 | ** | |
8560 | ** <ol><li> By mapping all synonyms to a single token. In this case, the | |
8561 | ** In the above example, this means that the tokenizer returns the | |
8562 | ** same token for inputs "first" and "1st". Say that token is in | |
8563 | ** fact "first", so that when the user inserts the document "I won | |
8564 | ** 1st place" entries are added to the index for tokens "i", "won", | |
8565 | ** "first" and "place". If the user then queries for '1st + place', | |
8566 | ** the tokenizer substitutes "first" for "1st" and the query works | |
8567 | ** as expected. | |
8568 | ** | |
8569 | ** <li> By adding multiple synonyms for a single term to the FTS index. | |
8570 | ** In this case, when tokenizing query text, the tokenizer may | |
8571 | ** provide multiple synonyms for a single term within the document. | |
8572 | ** FTS5 then queries the index for each synonym individually. For | |
8573 | ** example, faced with the query: | |
8574 | ** | |
8575 | ** <codeblock> | |
8576 | ** ... MATCH 'first place'</codeblock> | |
8577 | ** | |
8578 | ** the tokenizer offers both "1st" and "first" as synonyms for the | |
8579 | ** first token in the MATCH query and FTS5 effectively runs a query | |
8580 | ** similar to: | |
8581 | ** | |
8582 | ** <codeblock> | |
8583 | ** ... MATCH '(first OR 1st) place'</codeblock> | |
8584 | ** | |
8585 | ** except that, for the purposes of auxiliary functions, the query | |
8586 | ** still appears to contain just two phrases - "(first OR 1st)" | |
8587 | ** being treated as a single phrase. | |
8588 | ** | |
8589 | ** <li> By adding multiple synonyms for a single term to the FTS index. | |
8590 | ** Using this method, when tokenizing document text, the tokenizer | |
8591 | ** provides multiple synonyms for each token. So that when a | |
8592 | ** document such as "I won first place" is tokenized, entries are | |
8593 | ** added to the FTS index for "i", "won", "first", "1st" and | |
8594 | ** "place". | |
8595 | ** | |
8596 | ** This way, even if the tokenizer does not provide synonyms | |
8597 | ** when tokenizing query text (it should not - to do would be | |
8598 | ** inefficient), it doesn't matter if the user queries for | |
8599 | ** 'first + place' or '1st + place', as there are entires in the | |
8600 | ** FTS index corresponding to both forms of the first token. | |
8601 | ** </ol> | |
8602 | ** | |
8603 | ** Whether it is parsing document or query text, any call to xToken that | |
8604 | ** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit | |
8605 | ** is considered to supply a synonym for the previous token. For example, | |
8606 | ** when parsing the document "I won first place", a tokenizer that supports | |
8607 | ** synonyms would call xToken() 5 times, as follows: | |
8608 | ** | |
8609 | ** <codeblock> | |
8610 | ** xToken(pCtx, 0, "i", 1, 0, 1); | |
8611 | ** xToken(pCtx, 0, "won", 3, 2, 5); | |
8612 | ** xToken(pCtx, 0, "first", 5, 6, 11); | |
8613 | ** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11); | |
8614 | ** xToken(pCtx, 0, "place", 5, 12, 17); | |
8615 | **</codeblock> | |
8616 | ** | |
8617 | ** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time | |
8618 | ** xToken() is called. Multiple synonyms may be specified for a single token | |
8619 | ** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence. | |
8620 | ** There is no limit to the number of synonyms that may be provided for a | |
8621 | ** single token. | |
8622 | ** | |
8623 | ** In many cases, method (1) above is the best approach. It does not add | |
8624 | ** extra data to the FTS index or require FTS5 to query for multiple terms, | |
8625 | ** so it is efficient in terms of disk space and query speed. However, it | |
8626 | ** does not support prefix queries very well. If, as suggested above, the | |
8627 | ** token "first" is subsituted for "1st" by the tokenizer, then the query: | |
8628 | ** | |
8629 | ** <codeblock> | |
8630 | ** ... MATCH '1s*'</codeblock> | |
8631 | ** | |
8632 | ** will not match documents that contain the token "1st" (as the tokenizer | |
8633 | ** will probably not map "1s" to any prefix of "first"). | |
8634 | ** | |
8635 | ** For full prefix support, method (3) may be preferred. In this case, | |
8636 | ** because the index contains entries for both "first" and "1st", prefix | |
8637 | ** queries such as 'fi*' or '1s*' will match correctly. However, because | |
8638 | ** extra entries are added to the FTS index, this method uses more space | |
8639 | ** within the database. | |
8640 | ** | |
8641 | ** Method (2) offers a midpoint between (1) and (3). Using this method, | |
8642 | ** a query such as '1s*' will match documents that contain the literal | |
8643 | ** token "1st", but not "first" (assuming the tokenizer is not able to | |
8644 | ** provide synonyms for prefixes). However, a non-prefix query like '1st' | |
8645 | ** will match against "1st" and "first". This method does not require | |
8646 | ** extra disk space, as no extra entries are added to the FTS index. | |
8647 | ** On the other hand, it may require more CPU cycles to run MATCH queries, | |
8648 | ** as separate queries of the FTS index are required for each synonym. | |
8649 | ** | |
8650 | ** When using methods (2) or (3), it is important that the tokenizer only | |
8651 | ** provide synonyms when tokenizing document text (method (2)) or query | |
8652 | ** text (method (3)), not both. Doing so will not cause any errors, but is | |
8653 | ** inefficient. | |
8654 | */ | |
8655 | typedef struct Fts5Tokenizer Fts5Tokenizer; | |
8656 | typedef struct fts5_tokenizer fts5_tokenizer; | |
8657 | struct fts5_tokenizer { | |
8658 | int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut); | |
8659 | void (*xDelete)(Fts5Tokenizer*); | |
8660 | int (*xTokenize)(Fts5Tokenizer*, | |
8661 | void *pCtx, | |
8662 | int flags, /* Mask of FTS5_TOKENIZE_* flags */ | |
8663 | const char *pText, int nText, | |
8664 | int (*xToken)( | |
8665 | void *pCtx, /* Copy of 2nd argument to xTokenize() */ | |
8666 | int tflags, /* Mask of FTS5_TOKEN_* flags */ | |
8667 | const char *pToken, /* Pointer to buffer containing token */ | |
8668 | int nToken, /* Size of token in bytes */ | |
8669 | int iStart, /* Byte offset of token within input text */ | |
8670 | int iEnd /* Byte offset of end of token within input text */ | |
8671 | ) | |
8672 | ); | |
8673 | }; | |
8674 | ||
8675 | /* Flags that may be passed as the third argument to xTokenize() */ | |
8676 | #define FTS5_TOKENIZE_QUERY 0x0001 | |
8677 | #define FTS5_TOKENIZE_PREFIX 0x0002 | |
8678 | #define FTS5_TOKENIZE_DOCUMENT 0x0004 | |
8679 | #define FTS5_TOKENIZE_AUX 0x0008 | |
8680 | ||
8681 | /* Flags that may be passed by the tokenizer implementation back to FTS5 | |
8682 | ** as the third argument to the supplied xToken callback. */ | |
8683 | #define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */ | |
8684 | ||
8685 | /* | |
8686 | ** END OF CUSTOM TOKENIZERS | |
8687 | *************************************************************************/ | |
8688 | ||
8689 | /************************************************************************* | |
8690 | ** FTS5 EXTENSION REGISTRATION API | |
8691 | */ | |
8692 | typedef struct fts5_api fts5_api; | |
8693 | struct fts5_api { | |
8694 | int iVersion; /* Currently always set to 2 */ | |
8695 | ||
8696 | /* Create a new tokenizer */ | |
8697 | int (*xCreateTokenizer)( | |
8698 | fts5_api *pApi, | |
8699 | const char *zName, | |
8700 | void *pContext, | |
8701 | fts5_tokenizer *pTokenizer, | |
8702 | void (*xDestroy)(void*) | |
8703 | ); | |
8704 | ||
8705 | /* Find an existing tokenizer */ | |
8706 | int (*xFindTokenizer)( | |
8707 | fts5_api *pApi, | |
8708 | const char *zName, | |
8709 | void **ppContext, | |
8710 | fts5_tokenizer *pTokenizer | |
8711 | ); | |
8712 | ||
8713 | /* Create a new auxiliary function */ | |
8714 | int (*xCreateFunction)( | |
8715 | fts5_api *pApi, | |
8716 | const char *zName, | |
8717 | void *pContext, | |
8718 | fts5_extension_function xFunction, | |
8719 | void (*xDestroy)(void*) | |
8720 | ); | |
8721 | }; | |
8722 | ||
8723 | /* | |
8724 | ** END OF REGISTRATION API | |
8725 | *************************************************************************/ | |
8726 | ||
8727 | #ifdef __cplusplus | |
8728 | } /* end of the 'extern "C"' block */ | |
8729 | #endif | |
8730 | ||
8731 | #endif /* _FTS5_H */ | |
8732 | ||
8733 |