xref: /sqlite-3.40.0/src/main.c (revision 79d5bc80)
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 ** Main file for the SQLite library.  The routines in this file
13 ** implement the programmer interface to the library.  Routines in
14 ** other files are for internal use by SQLite and should not be
15 ** accessed by users of the library.
16 */
17 #include "sqliteInt.h"
18 
19 #ifdef SQLITE_ENABLE_FTS3
20 # include "fts3.h"
21 #endif
22 #ifdef SQLITE_ENABLE_RTREE
23 # include "rtree.h"
24 #endif
25 #if defined(SQLITE_ENABLE_ICU) || defined(SQLITE_ENABLE_ICU_COLLATIONS)
26 # include "sqliteicu.h"
27 #endif
28 #ifdef SQLITE_ENABLE_JSON1
29 int sqlite3Json1Init(sqlite3*);
30 #endif
31 #ifdef SQLITE_ENABLE_STMTVTAB
32 int sqlite3StmtVtabInit(sqlite3*);
33 #endif
34 #ifdef SQLITE_ENABLE_FTS5
35 int sqlite3Fts5Init(sqlite3*);
36 #endif
37 
38 #ifndef SQLITE_AMALGAMATION
39 /* IMPLEMENTATION-OF: R-46656-45156 The sqlite3_version[] string constant
40 ** contains the text of SQLITE_VERSION macro.
41 */
42 const char sqlite3_version[] = SQLITE_VERSION;
43 #endif
44 
45 /* IMPLEMENTATION-OF: R-53536-42575 The sqlite3_libversion() function returns
46 ** a pointer to the to the sqlite3_version[] string constant.
47 */
48 const char *sqlite3_libversion(void){ return sqlite3_version; }
49 
50 /* IMPLEMENTATION-OF: R-25063-23286 The sqlite3_sourceid() function returns a
51 ** pointer to a string constant whose value is the same as the
52 ** SQLITE_SOURCE_ID C preprocessor macro. Except if SQLite is built using
53 ** an edited copy of the amalgamation, then the last four characters of
54 ** the hash might be different from SQLITE_SOURCE_ID.
55 */
56 const char *sqlite3_sourceid(void){ return SQLITE_SOURCE_ID; }
57 
58 /* IMPLEMENTATION-OF: R-35210-63508 The sqlite3_libversion_number() function
59 ** returns an integer equal to SQLITE_VERSION_NUMBER.
60 */
61 int sqlite3_libversion_number(void){ return SQLITE_VERSION_NUMBER; }
62 
63 /* IMPLEMENTATION-OF: R-20790-14025 The sqlite3_threadsafe() function returns
64 ** zero if and only if SQLite was compiled with mutexing code omitted due to
65 ** the SQLITE_THREADSAFE compile-time option being set to 0.
66 */
67 int sqlite3_threadsafe(void){ return SQLITE_THREADSAFE; }
68 
69 /*
70 ** When compiling the test fixture or with debugging enabled (on Win32),
71 ** this variable being set to non-zero will cause OSTRACE macros to emit
72 ** extra diagnostic information.
73 */
74 #ifdef SQLITE_HAVE_OS_TRACE
75 # ifndef SQLITE_DEBUG_OS_TRACE
76 #   define SQLITE_DEBUG_OS_TRACE 0
77 # endif
78   int sqlite3OSTrace = SQLITE_DEBUG_OS_TRACE;
79 #endif
80 
81 #if !defined(SQLITE_OMIT_TRACE) && defined(SQLITE_ENABLE_IOTRACE)
82 /*
83 ** If the following function pointer is not NULL and if
84 ** SQLITE_ENABLE_IOTRACE is enabled, then messages describing
85 ** I/O active are written using this function.  These messages
86 ** are intended for debugging activity only.
87 */
88 SQLITE_API void (SQLITE_CDECL *sqlite3IoTrace)(const char*, ...) = 0;
89 #endif
90 
91 /*
92 ** If the following global variable points to a string which is the
93 ** name of a directory, then that directory will be used to store
94 ** temporary files.
95 **
96 ** See also the "PRAGMA temp_store_directory" SQL command.
97 */
98 char *sqlite3_temp_directory = 0;
99 
100 /*
101 ** If the following global variable points to a string which is the
102 ** name of a directory, then that directory will be used to store
103 ** all database files specified with a relative pathname.
104 **
105 ** See also the "PRAGMA data_store_directory" SQL command.
106 */
107 char *sqlite3_data_directory = 0;
108 
109 /*
110 ** Initialize SQLite.
111 **
112 ** This routine must be called to initialize the memory allocation,
113 ** VFS, and mutex subsystems prior to doing any serious work with
114 ** SQLite.  But as long as you do not compile with SQLITE_OMIT_AUTOINIT
115 ** this routine will be called automatically by key routines such as
116 ** sqlite3_open().
117 **
118 ** This routine is a no-op except on its very first call for the process,
119 ** or for the first call after a call to sqlite3_shutdown.
120 **
121 ** The first thread to call this routine runs the initialization to
122 ** completion.  If subsequent threads call this routine before the first
123 ** thread has finished the initialization process, then the subsequent
124 ** threads must block until the first thread finishes with the initialization.
125 **
126 ** The first thread might call this routine recursively.  Recursive
127 ** calls to this routine should not block, of course.  Otherwise the
128 ** initialization process would never complete.
129 **
130 ** Let X be the first thread to enter this routine.  Let Y be some other
131 ** thread.  Then while the initial invocation of this routine by X is
132 ** incomplete, it is required that:
133 **
134 **    *  Calls to this routine from Y must block until the outer-most
135 **       call by X completes.
136 **
137 **    *  Recursive calls to this routine from thread X return immediately
138 **       without blocking.
139 */
140 int sqlite3_initialize(void){
141   MUTEX_LOGIC( sqlite3_mutex *pMaster; )       /* The main static mutex */
142   int rc;                                      /* Result code */
143 #ifdef SQLITE_EXTRA_INIT
144   int bRunExtraInit = 0;                       /* Extra initialization needed */
145 #endif
146 
147 #ifdef SQLITE_OMIT_WSD
148   rc = sqlite3_wsd_init(4096, 24);
149   if( rc!=SQLITE_OK ){
150     return rc;
151   }
152 #endif
153 
154   /* If the following assert() fails on some obscure processor/compiler
155   ** combination, the work-around is to set the correct pointer
156   ** size at compile-time using -DSQLITE_PTRSIZE=n compile-time option */
157   assert( SQLITE_PTRSIZE==sizeof(char*) );
158 
159   /* If SQLite is already completely initialized, then this call
160   ** to sqlite3_initialize() should be a no-op.  But the initialization
161   ** must be complete.  So isInit must not be set until the very end
162   ** of this routine.
163   */
164   if( sqlite3GlobalConfig.isInit ) return SQLITE_OK;
165 
166   /* Make sure the mutex subsystem is initialized.  If unable to
167   ** initialize the mutex subsystem, return early with the error.
168   ** If the system is so sick that we are unable to allocate a mutex,
169   ** there is not much SQLite is going to be able to do.
170   **
171   ** The mutex subsystem must take care of serializing its own
172   ** initialization.
173   */
174   rc = sqlite3MutexInit();
175   if( rc ) return rc;
176 
177   /* Initialize the malloc() system and the recursive pInitMutex mutex.
178   ** This operation is protected by the STATIC_MASTER mutex.  Note that
179   ** MutexAlloc() is called for a static mutex prior to initializing the
180   ** malloc subsystem - this implies that the allocation of a static
181   ** mutex must not require support from the malloc subsystem.
182   */
183   MUTEX_LOGIC( pMaster = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER); )
184   sqlite3_mutex_enter(pMaster);
185   sqlite3GlobalConfig.isMutexInit = 1;
186   if( !sqlite3GlobalConfig.isMallocInit ){
187     rc = sqlite3MallocInit();
188   }
189   if( rc==SQLITE_OK ){
190     sqlite3GlobalConfig.isMallocInit = 1;
191     if( !sqlite3GlobalConfig.pInitMutex ){
192       sqlite3GlobalConfig.pInitMutex =
193            sqlite3MutexAlloc(SQLITE_MUTEX_RECURSIVE);
194       if( sqlite3GlobalConfig.bCoreMutex && !sqlite3GlobalConfig.pInitMutex ){
195         rc = SQLITE_NOMEM_BKPT;
196       }
197     }
198   }
199   if( rc==SQLITE_OK ){
200     sqlite3GlobalConfig.nRefInitMutex++;
201   }
202   sqlite3_mutex_leave(pMaster);
203 
204   /* If rc is not SQLITE_OK at this point, then either the malloc
205   ** subsystem could not be initialized or the system failed to allocate
206   ** the pInitMutex mutex. Return an error in either case.  */
207   if( rc!=SQLITE_OK ){
208     return rc;
209   }
210 
211   /* Do the rest of the initialization under the recursive mutex so
212   ** that we will be able to handle recursive calls into
213   ** sqlite3_initialize().  The recursive calls normally come through
214   ** sqlite3_os_init() when it invokes sqlite3_vfs_register(), but other
215   ** recursive calls might also be possible.
216   **
217   ** IMPLEMENTATION-OF: R-00140-37445 SQLite automatically serializes calls
218   ** to the xInit method, so the xInit method need not be threadsafe.
219   **
220   ** The following mutex is what serializes access to the appdef pcache xInit
221   ** methods.  The sqlite3_pcache_methods.xInit() all is embedded in the
222   ** call to sqlite3PcacheInitialize().
223   */
224   sqlite3_mutex_enter(sqlite3GlobalConfig.pInitMutex);
225   if( sqlite3GlobalConfig.isInit==0 && sqlite3GlobalConfig.inProgress==0 ){
226     sqlite3GlobalConfig.inProgress = 1;
227 #ifdef SQLITE_ENABLE_SQLLOG
228     {
229       extern void sqlite3_init_sqllog(void);
230       sqlite3_init_sqllog();
231     }
232 #endif
233     memset(&sqlite3BuiltinFunctions, 0, sizeof(sqlite3BuiltinFunctions));
234     sqlite3RegisterBuiltinFunctions();
235     if( sqlite3GlobalConfig.isPCacheInit==0 ){
236       rc = sqlite3PcacheInitialize();
237     }
238     if( rc==SQLITE_OK ){
239       sqlite3GlobalConfig.isPCacheInit = 1;
240       rc = sqlite3OsInit();
241     }
242 #ifdef SQLITE_ENABLE_DESERIALIZE
243     if( rc==SQLITE_OK ){
244       rc = sqlite3MemdbInit();
245     }
246 #endif
247     if( rc==SQLITE_OK ){
248       sqlite3PCacheBufferSetup( sqlite3GlobalConfig.pPage,
249           sqlite3GlobalConfig.szPage, sqlite3GlobalConfig.nPage);
250       sqlite3GlobalConfig.isInit = 1;
251 #ifdef SQLITE_EXTRA_INIT
252       bRunExtraInit = 1;
253 #endif
254     }
255     sqlite3GlobalConfig.inProgress = 0;
256   }
257   sqlite3_mutex_leave(sqlite3GlobalConfig.pInitMutex);
258 
259   /* Go back under the static mutex and clean up the recursive
260   ** mutex to prevent a resource leak.
261   */
262   sqlite3_mutex_enter(pMaster);
263   sqlite3GlobalConfig.nRefInitMutex--;
264   if( sqlite3GlobalConfig.nRefInitMutex<=0 ){
265     assert( sqlite3GlobalConfig.nRefInitMutex==0 );
266     sqlite3_mutex_free(sqlite3GlobalConfig.pInitMutex);
267     sqlite3GlobalConfig.pInitMutex = 0;
268   }
269   sqlite3_mutex_leave(pMaster);
270 
271   /* The following is just a sanity check to make sure SQLite has
272   ** been compiled correctly.  It is important to run this code, but
273   ** we don't want to run it too often and soak up CPU cycles for no
274   ** reason.  So we run it once during initialization.
275   */
276 #ifndef NDEBUG
277 #ifndef SQLITE_OMIT_FLOATING_POINT
278   /* This section of code's only "output" is via assert() statements. */
279   if( rc==SQLITE_OK ){
280     u64 x = (((u64)1)<<63)-1;
281     double y;
282     assert(sizeof(x)==8);
283     assert(sizeof(x)==sizeof(y));
284     memcpy(&y, &x, 8);
285     assert( sqlite3IsNaN(y) );
286   }
287 #endif
288 #endif
289 
290   /* Do extra initialization steps requested by the SQLITE_EXTRA_INIT
291   ** compile-time option.
292   */
293 #ifdef SQLITE_EXTRA_INIT
294   if( bRunExtraInit ){
295     int SQLITE_EXTRA_INIT(const char*);
296     rc = SQLITE_EXTRA_INIT(0);
297   }
298 #endif
299 
300   return rc;
301 }
302 
303 /*
304 ** Undo the effects of sqlite3_initialize().  Must not be called while
305 ** there are outstanding database connections or memory allocations or
306 ** while any part of SQLite is otherwise in use in any thread.  This
307 ** routine is not threadsafe.  But it is safe to invoke this routine
308 ** on when SQLite is already shut down.  If SQLite is already shut down
309 ** when this routine is invoked, then this routine is a harmless no-op.
310 */
311 int sqlite3_shutdown(void){
312 #ifdef SQLITE_OMIT_WSD
313   int rc = sqlite3_wsd_init(4096, 24);
314   if( rc!=SQLITE_OK ){
315     return rc;
316   }
317 #endif
318 
319   if( sqlite3GlobalConfig.isInit ){
320 #ifdef SQLITE_EXTRA_SHUTDOWN
321     void SQLITE_EXTRA_SHUTDOWN(void);
322     SQLITE_EXTRA_SHUTDOWN();
323 #endif
324     sqlite3_os_end();
325     sqlite3_reset_auto_extension();
326     sqlite3GlobalConfig.isInit = 0;
327   }
328   if( sqlite3GlobalConfig.isPCacheInit ){
329     sqlite3PcacheShutdown();
330     sqlite3GlobalConfig.isPCacheInit = 0;
331   }
332   if( sqlite3GlobalConfig.isMallocInit ){
333     sqlite3MallocEnd();
334     sqlite3GlobalConfig.isMallocInit = 0;
335 
336 #ifndef SQLITE_OMIT_SHUTDOWN_DIRECTORIES
337     /* The heap subsystem has now been shutdown and these values are supposed
338     ** to be NULL or point to memory that was obtained from sqlite3_malloc(),
339     ** which would rely on that heap subsystem; therefore, make sure these
340     ** values cannot refer to heap memory that was just invalidated when the
341     ** heap subsystem was shutdown.  This is only done if the current call to
342     ** this function resulted in the heap subsystem actually being shutdown.
343     */
344     sqlite3_data_directory = 0;
345     sqlite3_temp_directory = 0;
346 #endif
347   }
348   if( sqlite3GlobalConfig.isMutexInit ){
349     sqlite3MutexEnd();
350     sqlite3GlobalConfig.isMutexInit = 0;
351   }
352 
353   return SQLITE_OK;
354 }
355 
356 /*
357 ** This API allows applications to modify the global configuration of
358 ** the SQLite library at run-time.
359 **
360 ** This routine should only be called when there are no outstanding
361 ** database connections or memory allocations.  This routine is not
362 ** threadsafe.  Failure to heed these warnings can lead to unpredictable
363 ** behavior.
364 */
365 int sqlite3_config(int op, ...){
366   va_list ap;
367   int rc = SQLITE_OK;
368 
369   /* sqlite3_config() shall return SQLITE_MISUSE if it is invoked while
370   ** the SQLite library is in use. */
371   if( sqlite3GlobalConfig.isInit ) return SQLITE_MISUSE_BKPT;
372 
373   va_start(ap, op);
374   switch( op ){
375 
376     /* Mutex configuration options are only available in a threadsafe
377     ** compile.
378     */
379 #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0  /* IMP: R-54466-46756 */
380     case SQLITE_CONFIG_SINGLETHREAD: {
381       /* EVIDENCE-OF: R-02748-19096 This option sets the threading mode to
382       ** Single-thread. */
383       sqlite3GlobalConfig.bCoreMutex = 0;  /* Disable mutex on core */
384       sqlite3GlobalConfig.bFullMutex = 0;  /* Disable mutex on connections */
385       break;
386     }
387 #endif
388 #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-20520-54086 */
389     case SQLITE_CONFIG_MULTITHREAD: {
390       /* EVIDENCE-OF: R-14374-42468 This option sets the threading mode to
391       ** Multi-thread. */
392       sqlite3GlobalConfig.bCoreMutex = 1;  /* Enable mutex on core */
393       sqlite3GlobalConfig.bFullMutex = 0;  /* Disable mutex on connections */
394       break;
395     }
396 #endif
397 #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-59593-21810 */
398     case SQLITE_CONFIG_SERIALIZED: {
399       /* EVIDENCE-OF: R-41220-51800 This option sets the threading mode to
400       ** Serialized. */
401       sqlite3GlobalConfig.bCoreMutex = 1;  /* Enable mutex on core */
402       sqlite3GlobalConfig.bFullMutex = 1;  /* Enable mutex on connections */
403       break;
404     }
405 #endif
406 #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-63666-48755 */
407     case SQLITE_CONFIG_MUTEX: {
408       /* Specify an alternative mutex implementation */
409       sqlite3GlobalConfig.mutex = *va_arg(ap, sqlite3_mutex_methods*);
410       break;
411     }
412 #endif
413 #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-14450-37597 */
414     case SQLITE_CONFIG_GETMUTEX: {
415       /* Retrieve the current mutex implementation */
416       *va_arg(ap, sqlite3_mutex_methods*) = sqlite3GlobalConfig.mutex;
417       break;
418     }
419 #endif
420 
421     case SQLITE_CONFIG_MALLOC: {
422       /* EVIDENCE-OF: R-55594-21030 The SQLITE_CONFIG_MALLOC option takes a
423       ** single argument which is a pointer to an instance of the
424       ** sqlite3_mem_methods structure. The argument specifies alternative
425       ** low-level memory allocation routines to be used in place of the memory
426       ** allocation routines built into SQLite. */
427       sqlite3GlobalConfig.m = *va_arg(ap, sqlite3_mem_methods*);
428       break;
429     }
430     case SQLITE_CONFIG_GETMALLOC: {
431       /* EVIDENCE-OF: R-51213-46414 The SQLITE_CONFIG_GETMALLOC option takes a
432       ** single argument which is a pointer to an instance of the
433       ** sqlite3_mem_methods structure. The sqlite3_mem_methods structure is
434       ** filled with the currently defined memory allocation routines. */
435       if( sqlite3GlobalConfig.m.xMalloc==0 ) sqlite3MemSetDefault();
436       *va_arg(ap, sqlite3_mem_methods*) = sqlite3GlobalConfig.m;
437       break;
438     }
439     case SQLITE_CONFIG_MEMSTATUS: {
440       /* EVIDENCE-OF: R-61275-35157 The SQLITE_CONFIG_MEMSTATUS option takes
441       ** single argument of type int, interpreted as a boolean, which enables
442       ** or disables the collection of memory allocation statistics. */
443       sqlite3GlobalConfig.bMemstat = va_arg(ap, int);
444       break;
445     }
446     case SQLITE_CONFIG_SMALL_MALLOC: {
447       sqlite3GlobalConfig.bSmallMalloc = va_arg(ap, int);
448       break;
449     }
450     case SQLITE_CONFIG_PAGECACHE: {
451       /* EVIDENCE-OF: R-18761-36601 There are three arguments to
452       ** SQLITE_CONFIG_PAGECACHE: A pointer to 8-byte aligned memory (pMem),
453       ** the size of each page cache line (sz), and the number of cache lines
454       ** (N). */
455       sqlite3GlobalConfig.pPage = va_arg(ap, void*);
456       sqlite3GlobalConfig.szPage = va_arg(ap, int);
457       sqlite3GlobalConfig.nPage = va_arg(ap, int);
458       break;
459     }
460     case SQLITE_CONFIG_PCACHE_HDRSZ: {
461       /* EVIDENCE-OF: R-39100-27317 The SQLITE_CONFIG_PCACHE_HDRSZ option takes
462       ** a single parameter which is a pointer to an integer and writes into
463       ** that integer the number of extra bytes per page required for each page
464       ** in SQLITE_CONFIG_PAGECACHE. */
465       *va_arg(ap, int*) =
466           sqlite3HeaderSizeBtree() +
467           sqlite3HeaderSizePcache() +
468           sqlite3HeaderSizePcache1();
469       break;
470     }
471 
472     case SQLITE_CONFIG_PCACHE: {
473       /* no-op */
474       break;
475     }
476     case SQLITE_CONFIG_GETPCACHE: {
477       /* now an error */
478       rc = SQLITE_ERROR;
479       break;
480     }
481 
482     case SQLITE_CONFIG_PCACHE2: {
483       /* EVIDENCE-OF: R-63325-48378 The SQLITE_CONFIG_PCACHE2 option takes a
484       ** single argument which is a pointer to an sqlite3_pcache_methods2
485       ** object. This object specifies the interface to a custom page cache
486       ** implementation. */
487       sqlite3GlobalConfig.pcache2 = *va_arg(ap, sqlite3_pcache_methods2*);
488       break;
489     }
490     case SQLITE_CONFIG_GETPCACHE2: {
491       /* EVIDENCE-OF: R-22035-46182 The SQLITE_CONFIG_GETPCACHE2 option takes a
492       ** single argument which is a pointer to an sqlite3_pcache_methods2
493       ** object. SQLite copies of the current page cache implementation into
494       ** that object. */
495       if( sqlite3GlobalConfig.pcache2.xInit==0 ){
496         sqlite3PCacheSetDefault();
497       }
498       *va_arg(ap, sqlite3_pcache_methods2*) = sqlite3GlobalConfig.pcache2;
499       break;
500     }
501 
502 /* EVIDENCE-OF: R-06626-12911 The SQLITE_CONFIG_HEAP option is only
503 ** available if SQLite is compiled with either SQLITE_ENABLE_MEMSYS3 or
504 ** SQLITE_ENABLE_MEMSYS5 and returns SQLITE_ERROR if invoked otherwise. */
505 #if defined(SQLITE_ENABLE_MEMSYS3) || defined(SQLITE_ENABLE_MEMSYS5)
506     case SQLITE_CONFIG_HEAP: {
507       /* EVIDENCE-OF: R-19854-42126 There are three arguments to
508       ** SQLITE_CONFIG_HEAP: An 8-byte aligned pointer to the memory, the
509       ** number of bytes in the memory buffer, and the minimum allocation size.
510       */
511       sqlite3GlobalConfig.pHeap = va_arg(ap, void*);
512       sqlite3GlobalConfig.nHeap = va_arg(ap, int);
513       sqlite3GlobalConfig.mnReq = va_arg(ap, int);
514 
515       if( sqlite3GlobalConfig.mnReq<1 ){
516         sqlite3GlobalConfig.mnReq = 1;
517       }else if( sqlite3GlobalConfig.mnReq>(1<<12) ){
518         /* cap min request size at 2^12 */
519         sqlite3GlobalConfig.mnReq = (1<<12);
520       }
521 
522       if( sqlite3GlobalConfig.pHeap==0 ){
523         /* EVIDENCE-OF: R-49920-60189 If the first pointer (the memory pointer)
524         ** is NULL, then SQLite reverts to using its default memory allocator
525         ** (the system malloc() implementation), undoing any prior invocation of
526         ** SQLITE_CONFIG_MALLOC.
527         **
528         ** Setting sqlite3GlobalConfig.m to all zeros will cause malloc to
529         ** revert to its default implementation when sqlite3_initialize() is run
530         */
531         memset(&sqlite3GlobalConfig.m, 0, sizeof(sqlite3GlobalConfig.m));
532       }else{
533         /* EVIDENCE-OF: R-61006-08918 If the memory pointer is not NULL then the
534         ** alternative memory allocator is engaged to handle all of SQLites
535         ** memory allocation needs. */
536 #ifdef SQLITE_ENABLE_MEMSYS3
537         sqlite3GlobalConfig.m = *sqlite3MemGetMemsys3();
538 #endif
539 #ifdef SQLITE_ENABLE_MEMSYS5
540         sqlite3GlobalConfig.m = *sqlite3MemGetMemsys5();
541 #endif
542       }
543       break;
544     }
545 #endif
546 
547     case SQLITE_CONFIG_LOOKASIDE: {
548       sqlite3GlobalConfig.szLookaside = va_arg(ap, int);
549       sqlite3GlobalConfig.nLookaside = va_arg(ap, int);
550       break;
551     }
552 
553     /* Record a pointer to the logger function and its first argument.
554     ** The default is NULL.  Logging is disabled if the function pointer is
555     ** NULL.
556     */
557     case SQLITE_CONFIG_LOG: {
558       /* MSVC is picky about pulling func ptrs from va lists.
559       ** http://support.microsoft.com/kb/47961
560       ** sqlite3GlobalConfig.xLog = va_arg(ap, void(*)(void*,int,const char*));
561       */
562       typedef void(*LOGFUNC_t)(void*,int,const char*);
563       sqlite3GlobalConfig.xLog = va_arg(ap, LOGFUNC_t);
564       sqlite3GlobalConfig.pLogArg = va_arg(ap, void*);
565       break;
566     }
567 
568     /* EVIDENCE-OF: R-55548-33817 The compile-time setting for URI filenames
569     ** can be changed at start-time using the
570     ** sqlite3_config(SQLITE_CONFIG_URI,1) or
571     ** sqlite3_config(SQLITE_CONFIG_URI,0) configuration calls.
572     */
573     case SQLITE_CONFIG_URI: {
574       /* EVIDENCE-OF: R-25451-61125 The SQLITE_CONFIG_URI option takes a single
575       ** argument of type int. If non-zero, then URI handling is globally
576       ** enabled. If the parameter is zero, then URI handling is globally
577       ** disabled. */
578       sqlite3GlobalConfig.bOpenUri = va_arg(ap, int);
579       break;
580     }
581 
582     case SQLITE_CONFIG_COVERING_INDEX_SCAN: {
583       /* EVIDENCE-OF: R-36592-02772 The SQLITE_CONFIG_COVERING_INDEX_SCAN
584       ** option takes a single integer argument which is interpreted as a
585       ** boolean in order to enable or disable the use of covering indices for
586       ** full table scans in the query optimizer. */
587       sqlite3GlobalConfig.bUseCis = va_arg(ap, int);
588       break;
589     }
590 
591 #ifdef SQLITE_ENABLE_SQLLOG
592     case SQLITE_CONFIG_SQLLOG: {
593       typedef void(*SQLLOGFUNC_t)(void*, sqlite3*, const char*, int);
594       sqlite3GlobalConfig.xSqllog = va_arg(ap, SQLLOGFUNC_t);
595       sqlite3GlobalConfig.pSqllogArg = va_arg(ap, void *);
596       break;
597     }
598 #endif
599 
600     case SQLITE_CONFIG_MMAP_SIZE: {
601       /* EVIDENCE-OF: R-58063-38258 SQLITE_CONFIG_MMAP_SIZE takes two 64-bit
602       ** integer (sqlite3_int64) values that are the default mmap size limit
603       ** (the default setting for PRAGMA mmap_size) and the maximum allowed
604       ** mmap size limit. */
605       sqlite3_int64 szMmap = va_arg(ap, sqlite3_int64);
606       sqlite3_int64 mxMmap = va_arg(ap, sqlite3_int64);
607       /* EVIDENCE-OF: R-53367-43190 If either argument to this option is
608       ** negative, then that argument is changed to its compile-time default.
609       **
610       ** EVIDENCE-OF: R-34993-45031 The maximum allowed mmap size will be
611       ** silently truncated if necessary so that it does not exceed the
612       ** compile-time maximum mmap size set by the SQLITE_MAX_MMAP_SIZE
613       ** compile-time option.
614       */
615       if( mxMmap<0 || mxMmap>SQLITE_MAX_MMAP_SIZE ){
616         mxMmap = SQLITE_MAX_MMAP_SIZE;
617       }
618       if( szMmap<0 ) szMmap = SQLITE_DEFAULT_MMAP_SIZE;
619       if( szMmap>mxMmap) szMmap = mxMmap;
620       sqlite3GlobalConfig.mxMmap = mxMmap;
621       sqlite3GlobalConfig.szMmap = szMmap;
622       break;
623     }
624 
625 #if SQLITE_OS_WIN && defined(SQLITE_WIN32_MALLOC) /* IMP: R-04780-55815 */
626     case SQLITE_CONFIG_WIN32_HEAPSIZE: {
627       /* EVIDENCE-OF: R-34926-03360 SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit
628       ** unsigned integer value that specifies the maximum size of the created
629       ** heap. */
630       sqlite3GlobalConfig.nHeap = va_arg(ap, int);
631       break;
632     }
633 #endif
634 
635     case SQLITE_CONFIG_PMASZ: {
636       sqlite3GlobalConfig.szPma = va_arg(ap, unsigned int);
637       break;
638     }
639 
640     case SQLITE_CONFIG_STMTJRNL_SPILL: {
641       sqlite3GlobalConfig.nStmtSpill = va_arg(ap, int);
642       break;
643     }
644 
645 #ifdef SQLITE_ENABLE_SORTER_REFERENCES
646     case SQLITE_CONFIG_SORTERREF_SIZE: {
647       int iVal = va_arg(ap, int);
648       if( iVal<0 ){
649         iVal = SQLITE_DEFAULT_SORTERREF_SIZE;
650       }
651       sqlite3GlobalConfig.szSorterRef = (u32)iVal;
652       break;
653     }
654 #endif /* SQLITE_ENABLE_SORTER_REFERENCES */
655 
656 #ifdef SQLITE_ENABLE_DESERIALIZE
657     case SQLITE_CONFIG_MEMDB_MAXSIZE: {
658       sqlite3GlobalConfig.mxMemdbSize = va_arg(ap, sqlite3_int64);
659       break;
660     }
661 #endif /* SQLITE_ENABLE_DESERIALIZE */
662 
663     default: {
664       rc = SQLITE_ERROR;
665       break;
666     }
667   }
668   va_end(ap);
669   return rc;
670 }
671 
672 /*
673 ** Set up the lookaside buffers for a database connection.
674 ** Return SQLITE_OK on success.
675 ** If lookaside is already active, return SQLITE_BUSY.
676 **
677 ** The sz parameter is the number of bytes in each lookaside slot.
678 ** The cnt parameter is the number of slots.  If pStart is NULL the
679 ** space for the lookaside memory is obtained from sqlite3_malloc().
680 ** If pStart is not NULL then it is sz*cnt bytes of memory to use for
681 ** the lookaside memory.
682 */
683 static int setupLookaside(sqlite3 *db, void *pBuf, int sz, int cnt){
684 #ifndef SQLITE_OMIT_LOOKASIDE
685   void *pStart;
686   sqlite3_int64 szAlloc = sz*(sqlite3_int64)cnt;
687   int nBig;   /* Number of full-size slots */
688   int nSm;    /* Number smaller LOOKASIDE_SMALL-byte slots */
689 
690   if( sqlite3LookasideUsed(db,0)>0 ){
691     return SQLITE_BUSY;
692   }
693   /* Free any existing lookaside buffer for this handle before
694   ** allocating a new one so we don't have to have space for
695   ** both at the same time.
696   */
697   if( db->lookaside.bMalloced ){
698     sqlite3_free(db->lookaside.pStart);
699   }
700   /* The size of a lookaside slot after ROUNDDOWN8 needs to be larger
701   ** than a pointer to be useful.
702   */
703   sz = ROUNDDOWN8(sz);  /* IMP: R-33038-09382 */
704   if( sz<=(int)sizeof(LookasideSlot*) ) sz = 0;
705   if( cnt<0 ) cnt = 0;
706   if( sz==0 || cnt==0 ){
707     sz = 0;
708     pStart = 0;
709   }else if( pBuf==0 ){
710     sqlite3BeginBenignMalloc();
711     pStart = sqlite3Malloc( szAlloc );  /* IMP: R-61949-35727 */
712     sqlite3EndBenignMalloc();
713     if( pStart ) szAlloc = sqlite3MallocSize(pStart);
714   }else{
715     pStart = pBuf;
716   }
717 #ifndef SQLITE_OMIT_TWOSIZE_LOOKASIDE
718   if( sz>=LOOKASIDE_SMALL*3 ){
719     nBig = szAlloc/(3*LOOKASIDE_SMALL+sz);
720     nSm = (szAlloc - sz*nBig)/LOOKASIDE_SMALL;
721   }else if( sz>=LOOKASIDE_SMALL*2 ){
722     nBig = szAlloc/(LOOKASIDE_SMALL+sz);
723     nSm = (szAlloc - sz*nBig)/LOOKASIDE_SMALL;
724   }else
725 #endif /* SQLITE_OMIT_TWOSIZE_LOOKASIDE */
726   if( sz>0 ){
727     nBig = szAlloc/sz;
728     nSm = 0;
729   }else{
730     nBig = nSm = 0;
731   }
732   db->lookaside.pStart = pStart;
733   db->lookaside.pInit = 0;
734   db->lookaside.pFree = 0;
735   db->lookaside.sz = (u16)sz;
736   db->lookaside.szTrue = (u16)sz;
737   if( pStart ){
738     int i;
739     LookasideSlot *p;
740     assert( sz > (int)sizeof(LookasideSlot*) );
741     p = (LookasideSlot*)pStart;
742     for(i=0; i<nBig; i++){
743       p->pNext = db->lookaside.pInit;
744       db->lookaside.pInit = p;
745       p = (LookasideSlot*)&((u8*)p)[sz];
746     }
747 #ifndef SQLITE_OMIT_TWOSIZE_LOOKASIDE
748     db->lookaside.pSmallInit = 0;
749     db->lookaside.pSmallFree = 0;
750     db->lookaside.pMiddle = p;
751     for(i=0; i<nSm; i++){
752       p->pNext = db->lookaside.pSmallInit;
753       db->lookaside.pSmallInit = p;
754       p = (LookasideSlot*)&((u8*)p)[LOOKASIDE_SMALL];
755     }
756 #endif /* SQLITE_OMIT_TWOSIZE_LOOKASIDE */
757     assert( ((uptr)p)<=szAlloc + (uptr)pStart );
758     db->lookaside.pEnd = p;
759     db->lookaside.bDisable = 0;
760     db->lookaside.bMalloced = pBuf==0 ?1:0;
761     db->lookaside.nSlot = nBig+nSm;
762   }else{
763     db->lookaside.pStart = db;
764 #ifndef SQLITE_OMIT_TWOSIZE_LOOKASIDE
765     db->lookaside.pSmallInit = 0;
766     db->lookaside.pSmallFree = 0;
767     db->lookaside.pMiddle = db;
768 #endif /* SQLITE_OMIT_TWOSIZE_LOOKASIDE */
769     db->lookaside.pEnd = db;
770     db->lookaside.bDisable = 1;
771     db->lookaside.sz = 0;
772     db->lookaside.bMalloced = 0;
773     db->lookaside.nSlot = 0;
774   }
775   assert( sqlite3LookasideUsed(db,0)==0 );
776 #endif /* SQLITE_OMIT_LOOKASIDE */
777   return SQLITE_OK;
778 }
779 
780 /*
781 ** Return the mutex associated with a database connection.
782 */
783 sqlite3_mutex *sqlite3_db_mutex(sqlite3 *db){
784 #ifdef SQLITE_ENABLE_API_ARMOR
785   if( !sqlite3SafetyCheckOk(db) ){
786     (void)SQLITE_MISUSE_BKPT;
787     return 0;
788   }
789 #endif
790   return db->mutex;
791 }
792 
793 /*
794 ** Free up as much memory as we can from the given database
795 ** connection.
796 */
797 int sqlite3_db_release_memory(sqlite3 *db){
798   int i;
799 
800 #ifdef SQLITE_ENABLE_API_ARMOR
801   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
802 #endif
803   sqlite3_mutex_enter(db->mutex);
804   sqlite3BtreeEnterAll(db);
805   for(i=0; i<db->nDb; i++){
806     Btree *pBt = db->aDb[i].pBt;
807     if( pBt ){
808       Pager *pPager = sqlite3BtreePager(pBt);
809       sqlite3PagerShrink(pPager);
810     }
811   }
812   sqlite3BtreeLeaveAll(db);
813   sqlite3_mutex_leave(db->mutex);
814   return SQLITE_OK;
815 }
816 
817 /*
818 ** Flush any dirty pages in the pager-cache for any attached database
819 ** to disk.
820 */
821 int sqlite3_db_cacheflush(sqlite3 *db){
822   int i;
823   int rc = SQLITE_OK;
824   int bSeenBusy = 0;
825 
826 #ifdef SQLITE_ENABLE_API_ARMOR
827   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
828 #endif
829   sqlite3_mutex_enter(db->mutex);
830   sqlite3BtreeEnterAll(db);
831   for(i=0; rc==SQLITE_OK && i<db->nDb; i++){
832     Btree *pBt = db->aDb[i].pBt;
833     if( pBt && sqlite3BtreeIsInTrans(pBt) ){
834       Pager *pPager = sqlite3BtreePager(pBt);
835       rc = sqlite3PagerFlush(pPager);
836       if( rc==SQLITE_BUSY ){
837         bSeenBusy = 1;
838         rc = SQLITE_OK;
839       }
840     }
841   }
842   sqlite3BtreeLeaveAll(db);
843   sqlite3_mutex_leave(db->mutex);
844   return ((rc==SQLITE_OK && bSeenBusy) ? SQLITE_BUSY : rc);
845 }
846 
847 /*
848 ** Configuration settings for an individual database connection
849 */
850 int sqlite3_db_config(sqlite3 *db, int op, ...){
851   va_list ap;
852   int rc;
853   va_start(ap, op);
854   switch( op ){
855     case SQLITE_DBCONFIG_MAINDBNAME: {
856       /* IMP: R-06824-28531 */
857       /* IMP: R-36257-52125 */
858       db->aDb[0].zDbSName = va_arg(ap,char*);
859       rc = SQLITE_OK;
860       break;
861     }
862     case SQLITE_DBCONFIG_LOOKASIDE: {
863       void *pBuf = va_arg(ap, void*); /* IMP: R-26835-10964 */
864       int sz = va_arg(ap, int);       /* IMP: R-47871-25994 */
865       int cnt = va_arg(ap, int);      /* IMP: R-04460-53386 */
866       rc = setupLookaside(db, pBuf, sz, cnt);
867       break;
868     }
869     default: {
870       static const struct {
871         int op;      /* The opcode */
872         u32 mask;    /* Mask of the bit in sqlite3.flags to set/clear */
873       } aFlagOp[] = {
874         { SQLITE_DBCONFIG_ENABLE_FKEY,           SQLITE_ForeignKeys    },
875         { SQLITE_DBCONFIG_ENABLE_TRIGGER,        SQLITE_EnableTrigger  },
876         { SQLITE_DBCONFIG_ENABLE_VIEW,           SQLITE_EnableView     },
877         { SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER, SQLITE_Fts3Tokenizer  },
878         { SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION, SQLITE_LoadExtension  },
879         { SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE,      SQLITE_NoCkptOnClose  },
880         { SQLITE_DBCONFIG_ENABLE_QPSG,           SQLITE_EnableQPSG     },
881         { SQLITE_DBCONFIG_TRIGGER_EQP,           SQLITE_TriggerEQP     },
882         { SQLITE_DBCONFIG_RESET_DATABASE,        SQLITE_ResetDatabase  },
883         { SQLITE_DBCONFIG_DEFENSIVE,             SQLITE_Defensive      },
884         { SQLITE_DBCONFIG_WRITABLE_SCHEMA,       SQLITE_WriteSchema|
885                                                  SQLITE_NoSchemaError  },
886         { SQLITE_DBCONFIG_LEGACY_ALTER_TABLE,    SQLITE_LegacyAlter    },
887         { SQLITE_DBCONFIG_DQS_DDL,               SQLITE_DqsDDL         },
888         { SQLITE_DBCONFIG_DQS_DML,               SQLITE_DqsDML         },
889         { SQLITE_DBCONFIG_LEGACY_FILE_FORMAT,    SQLITE_LegacyFileFmt  },
890         { SQLITE_DBCONFIG_UNSAFE_FUNC_IN_VIEW,   SQLITE_UnsafeInView   },
891         { SQLITE_DBCONFIG_VTAB_IN_VIEW,          SQLITE_VtabInView     },
892       };
893       unsigned int i;
894       rc = SQLITE_ERROR; /* IMP: R-42790-23372 */
895       for(i=0; i<ArraySize(aFlagOp); i++){
896         if( aFlagOp[i].op==op ){
897           int onoff = va_arg(ap, int);
898           int *pRes = va_arg(ap, int*);
899           u64 oldFlags = db->flags;
900           if( onoff>0 ){
901             db->flags |= aFlagOp[i].mask;
902           }else if( onoff==0 ){
903             db->flags &= ~(u64)aFlagOp[i].mask;
904           }
905           if( oldFlags!=db->flags ){
906             sqlite3ExpirePreparedStatements(db, 0);
907           }
908           if( pRes ){
909             *pRes = (db->flags & aFlagOp[i].mask)!=0;
910           }
911           rc = SQLITE_OK;
912           break;
913         }
914       }
915       break;
916     }
917   }
918   va_end(ap);
919   return rc;
920 }
921 
922 /*
923 ** This is the default collating function named "BINARY" which is always
924 ** available.
925 */
926 static int binCollFunc(
927   void *NotUsed,
928   int nKey1, const void *pKey1,
929   int nKey2, const void *pKey2
930 ){
931   int rc, n;
932   UNUSED_PARAMETER(NotUsed);
933   n = nKey1<nKey2 ? nKey1 : nKey2;
934   /* EVIDENCE-OF: R-65033-28449 The built-in BINARY collation compares
935   ** strings byte by byte using the memcmp() function from the standard C
936   ** library. */
937   assert( pKey1 && pKey2 );
938   rc = memcmp(pKey1, pKey2, n);
939   if( rc==0 ){
940     rc = nKey1 - nKey2;
941   }
942   return rc;
943 }
944 
945 /*
946 ** This is the collating function named "RTRIM" which is always
947 ** available.  Ignore trailing spaces.
948 */
949 static int rtrimCollFunc(
950   void *pUser,
951   int nKey1, const void *pKey1,
952   int nKey2, const void *pKey2
953 ){
954   const u8 *pK1 = (const u8*)pKey1;
955   const u8 *pK2 = (const u8*)pKey2;
956   while( nKey1 && pK1[nKey1-1]==' ' ) nKey1--;
957   while( nKey2 && pK2[nKey2-1]==' ' ) nKey2--;
958   return binCollFunc(pUser, nKey1, pKey1, nKey2, pKey2);
959 }
960 
961 /*
962 ** Return true if CollSeq is the default built-in BINARY.
963 */
964 int sqlite3IsBinary(const CollSeq *p){
965   assert( p==0 || p->xCmp!=binCollFunc || strcmp(p->zName,"BINARY")==0 );
966   return p==0 || p->xCmp==binCollFunc;
967 }
968 
969 /*
970 ** Another built-in collating sequence: NOCASE.
971 **
972 ** This collating sequence is intended to be used for "case independent
973 ** comparison". SQLite's knowledge of upper and lower case equivalents
974 ** extends only to the 26 characters used in the English language.
975 **
976 ** At the moment there is only a UTF-8 implementation.
977 */
978 static int nocaseCollatingFunc(
979   void *NotUsed,
980   int nKey1, const void *pKey1,
981   int nKey2, const void *pKey2
982 ){
983   int r = sqlite3StrNICmp(
984       (const char *)pKey1, (const char *)pKey2, (nKey1<nKey2)?nKey1:nKey2);
985   UNUSED_PARAMETER(NotUsed);
986   if( 0==r ){
987     r = nKey1-nKey2;
988   }
989   return r;
990 }
991 
992 /*
993 ** Return the ROWID of the most recent insert
994 */
995 sqlite_int64 sqlite3_last_insert_rowid(sqlite3 *db){
996 #ifdef SQLITE_ENABLE_API_ARMOR
997   if( !sqlite3SafetyCheckOk(db) ){
998     (void)SQLITE_MISUSE_BKPT;
999     return 0;
1000   }
1001 #endif
1002   return db->lastRowid;
1003 }
1004 
1005 /*
1006 ** Set the value returned by the sqlite3_last_insert_rowid() API function.
1007 */
1008 void sqlite3_set_last_insert_rowid(sqlite3 *db, sqlite3_int64 iRowid){
1009 #ifdef SQLITE_ENABLE_API_ARMOR
1010   if( !sqlite3SafetyCheckOk(db) ){
1011     (void)SQLITE_MISUSE_BKPT;
1012     return;
1013   }
1014 #endif
1015   sqlite3_mutex_enter(db->mutex);
1016   db->lastRowid = iRowid;
1017   sqlite3_mutex_leave(db->mutex);
1018 }
1019 
1020 /*
1021 ** Return the number of changes in the most recent call to sqlite3_exec().
1022 */
1023 int sqlite3_changes(sqlite3 *db){
1024 #ifdef SQLITE_ENABLE_API_ARMOR
1025   if( !sqlite3SafetyCheckOk(db) ){
1026     (void)SQLITE_MISUSE_BKPT;
1027     return 0;
1028   }
1029 #endif
1030   return db->nChange;
1031 }
1032 
1033 /*
1034 ** Return the number of changes since the database handle was opened.
1035 */
1036 int sqlite3_total_changes(sqlite3 *db){
1037 #ifdef SQLITE_ENABLE_API_ARMOR
1038   if( !sqlite3SafetyCheckOk(db) ){
1039     (void)SQLITE_MISUSE_BKPT;
1040     return 0;
1041   }
1042 #endif
1043   return db->nTotalChange;
1044 }
1045 
1046 /*
1047 ** Close all open savepoints. This function only manipulates fields of the
1048 ** database handle object, it does not close any savepoints that may be open
1049 ** at the b-tree/pager level.
1050 */
1051 void sqlite3CloseSavepoints(sqlite3 *db){
1052   while( db->pSavepoint ){
1053     Savepoint *pTmp = db->pSavepoint;
1054     db->pSavepoint = pTmp->pNext;
1055     sqlite3DbFree(db, pTmp);
1056   }
1057   db->nSavepoint = 0;
1058   db->nStatement = 0;
1059   db->isTransactionSavepoint = 0;
1060 }
1061 
1062 /*
1063 ** Invoke the destructor function associated with FuncDef p, if any. Except,
1064 ** if this is not the last copy of the function, do not invoke it. Multiple
1065 ** copies of a single function are created when create_function() is called
1066 ** with SQLITE_ANY as the encoding.
1067 */
1068 static void functionDestroy(sqlite3 *db, FuncDef *p){
1069   FuncDestructor *pDestructor = p->u.pDestructor;
1070   if( pDestructor ){
1071     pDestructor->nRef--;
1072     if( pDestructor->nRef==0 ){
1073       pDestructor->xDestroy(pDestructor->pUserData);
1074       sqlite3DbFree(db, pDestructor);
1075     }
1076   }
1077 }
1078 
1079 /*
1080 ** Disconnect all sqlite3_vtab objects that belong to database connection
1081 ** db. This is called when db is being closed.
1082 */
1083 static void disconnectAllVtab(sqlite3 *db){
1084 #ifndef SQLITE_OMIT_VIRTUALTABLE
1085   int i;
1086   HashElem *p;
1087   sqlite3BtreeEnterAll(db);
1088   for(i=0; i<db->nDb; i++){
1089     Schema *pSchema = db->aDb[i].pSchema;
1090     if( pSchema ){
1091       for(p=sqliteHashFirst(&pSchema->tblHash); p; p=sqliteHashNext(p)){
1092         Table *pTab = (Table *)sqliteHashData(p);
1093         if( IsVirtual(pTab) ) sqlite3VtabDisconnect(db, pTab);
1094       }
1095     }
1096   }
1097   for(p=sqliteHashFirst(&db->aModule); p; p=sqliteHashNext(p)){
1098     Module *pMod = (Module *)sqliteHashData(p);
1099     if( pMod->pEpoTab ){
1100       sqlite3VtabDisconnect(db, pMod->pEpoTab);
1101     }
1102   }
1103   sqlite3VtabUnlockList(db);
1104   sqlite3BtreeLeaveAll(db);
1105 #else
1106   UNUSED_PARAMETER(db);
1107 #endif
1108 }
1109 
1110 /*
1111 ** Return TRUE if database connection db has unfinalized prepared
1112 ** statements or unfinished sqlite3_backup objects.
1113 */
1114 static int connectionIsBusy(sqlite3 *db){
1115   int j;
1116   assert( sqlite3_mutex_held(db->mutex) );
1117   if( db->pVdbe ) return 1;
1118   for(j=0; j<db->nDb; j++){
1119     Btree *pBt = db->aDb[j].pBt;
1120     if( pBt && sqlite3BtreeIsInBackup(pBt) ) return 1;
1121   }
1122   return 0;
1123 }
1124 
1125 /*
1126 ** Close an existing SQLite database
1127 */
1128 static int sqlite3Close(sqlite3 *db, int forceZombie){
1129   if( !db ){
1130     /* EVIDENCE-OF: R-63257-11740 Calling sqlite3_close() or
1131     ** sqlite3_close_v2() with a NULL pointer argument is a harmless no-op. */
1132     return SQLITE_OK;
1133   }
1134   if( !sqlite3SafetyCheckSickOrOk(db) ){
1135     return SQLITE_MISUSE_BKPT;
1136   }
1137   sqlite3_mutex_enter(db->mutex);
1138   if( db->mTrace & SQLITE_TRACE_CLOSE ){
1139     db->xTrace(SQLITE_TRACE_CLOSE, db->pTraceArg, db, 0);
1140   }
1141 
1142   /* Force xDisconnect calls on all virtual tables */
1143   disconnectAllVtab(db);
1144 
1145   /* If a transaction is open, the disconnectAllVtab() call above
1146   ** will not have called the xDisconnect() method on any virtual
1147   ** tables in the db->aVTrans[] array. The following sqlite3VtabRollback()
1148   ** call will do so. We need to do this before the check for active
1149   ** SQL statements below, as the v-table implementation may be storing
1150   ** some prepared statements internally.
1151   */
1152   sqlite3VtabRollback(db);
1153 
1154   /* Legacy behavior (sqlite3_close() behavior) is to return
1155   ** SQLITE_BUSY if the connection can not be closed immediately.
1156   */
1157   if( !forceZombie && connectionIsBusy(db) ){
1158     sqlite3ErrorWithMsg(db, SQLITE_BUSY, "unable to close due to unfinalized "
1159        "statements or unfinished backups");
1160     sqlite3_mutex_leave(db->mutex);
1161     return SQLITE_BUSY;
1162   }
1163 
1164 #ifdef SQLITE_ENABLE_SQLLOG
1165   if( sqlite3GlobalConfig.xSqllog ){
1166     /* Closing the handle. Fourth parameter is passed the value 2. */
1167     sqlite3GlobalConfig.xSqllog(sqlite3GlobalConfig.pSqllogArg, db, 0, 2);
1168   }
1169 #endif
1170 
1171   /* Convert the connection into a zombie and then close it.
1172   */
1173   db->magic = SQLITE_MAGIC_ZOMBIE;
1174   sqlite3LeaveMutexAndCloseZombie(db);
1175   return SQLITE_OK;
1176 }
1177 
1178 /*
1179 ** Two variations on the public interface for closing a database
1180 ** connection. The sqlite3_close() version returns SQLITE_BUSY and
1181 ** leaves the connection option if there are unfinalized prepared
1182 ** statements or unfinished sqlite3_backups.  The sqlite3_close_v2()
1183 ** version forces the connection to become a zombie if there are
1184 ** unclosed resources, and arranges for deallocation when the last
1185 ** prepare statement or sqlite3_backup closes.
1186 */
1187 int sqlite3_close(sqlite3 *db){ return sqlite3Close(db,0); }
1188 int sqlite3_close_v2(sqlite3 *db){ return sqlite3Close(db,1); }
1189 
1190 
1191 /*
1192 ** Close the mutex on database connection db.
1193 **
1194 ** Furthermore, if database connection db is a zombie (meaning that there
1195 ** has been a prior call to sqlite3_close(db) or sqlite3_close_v2(db)) and
1196 ** every sqlite3_stmt has now been finalized and every sqlite3_backup has
1197 ** finished, then free all resources.
1198 */
1199 void sqlite3LeaveMutexAndCloseZombie(sqlite3 *db){
1200   HashElem *i;                    /* Hash table iterator */
1201   int j;
1202 
1203   /* If there are outstanding sqlite3_stmt or sqlite3_backup objects
1204   ** or if the connection has not yet been closed by sqlite3_close_v2(),
1205   ** then just leave the mutex and return.
1206   */
1207   if( db->magic!=SQLITE_MAGIC_ZOMBIE || connectionIsBusy(db) ){
1208     sqlite3_mutex_leave(db->mutex);
1209     return;
1210   }
1211 
1212   /* If we reach this point, it means that the database connection has
1213   ** closed all sqlite3_stmt and sqlite3_backup objects and has been
1214   ** passed to sqlite3_close (meaning that it is a zombie).  Therefore,
1215   ** go ahead and free all resources.
1216   */
1217 
1218   /* If a transaction is open, roll it back. This also ensures that if
1219   ** any database schemas have been modified by an uncommitted transaction
1220   ** they are reset. And that the required b-tree mutex is held to make
1221   ** the pager rollback and schema reset an atomic operation. */
1222   sqlite3RollbackAll(db, SQLITE_OK);
1223 
1224   /* Free any outstanding Savepoint structures. */
1225   sqlite3CloseSavepoints(db);
1226 
1227   /* Close all database connections */
1228   for(j=0; j<db->nDb; j++){
1229     struct Db *pDb = &db->aDb[j];
1230     if( pDb->pBt ){
1231       sqlite3BtreeClose(pDb->pBt);
1232       pDb->pBt = 0;
1233       if( j!=1 ){
1234         pDb->pSchema = 0;
1235       }
1236     }
1237   }
1238   /* Clear the TEMP schema separately and last */
1239   if( db->aDb[1].pSchema ){
1240     sqlite3SchemaClear(db->aDb[1].pSchema);
1241   }
1242   sqlite3VtabUnlockList(db);
1243 
1244   /* Free up the array of auxiliary databases */
1245   sqlite3CollapseDatabaseArray(db);
1246   assert( db->nDb<=2 );
1247   assert( db->aDb==db->aDbStatic );
1248 
1249   /* Tell the code in notify.c that the connection no longer holds any
1250   ** locks and does not require any further unlock-notify callbacks.
1251   */
1252   sqlite3ConnectionClosed(db);
1253 
1254   for(i=sqliteHashFirst(&db->aFunc); i; i=sqliteHashNext(i)){
1255     FuncDef *pNext, *p;
1256     p = sqliteHashData(i);
1257     do{
1258       functionDestroy(db, p);
1259       pNext = p->pNext;
1260       sqlite3DbFree(db, p);
1261       p = pNext;
1262     }while( p );
1263   }
1264   sqlite3HashClear(&db->aFunc);
1265   for(i=sqliteHashFirst(&db->aCollSeq); i; i=sqliteHashNext(i)){
1266     CollSeq *pColl = (CollSeq *)sqliteHashData(i);
1267     /* Invoke any destructors registered for collation sequence user data. */
1268     for(j=0; j<3; j++){
1269       if( pColl[j].xDel ){
1270         pColl[j].xDel(pColl[j].pUser);
1271       }
1272     }
1273     sqlite3DbFree(db, pColl);
1274   }
1275   sqlite3HashClear(&db->aCollSeq);
1276 #ifndef SQLITE_OMIT_VIRTUALTABLE
1277   for(i=sqliteHashFirst(&db->aModule); i; i=sqliteHashNext(i)){
1278     Module *pMod = (Module *)sqliteHashData(i);
1279     sqlite3VtabEponymousTableClear(db, pMod);
1280     sqlite3VtabModuleUnref(db, pMod);
1281   }
1282   sqlite3HashClear(&db->aModule);
1283 #endif
1284 
1285   sqlite3Error(db, SQLITE_OK); /* Deallocates any cached error strings. */
1286   sqlite3ValueFree(db->pErr);
1287   sqlite3CloseExtensions(db);
1288 #if SQLITE_USER_AUTHENTICATION
1289   sqlite3_free(db->auth.zAuthUser);
1290   sqlite3_free(db->auth.zAuthPW);
1291 #endif
1292 
1293   db->magic = SQLITE_MAGIC_ERROR;
1294 
1295   /* The temp-database schema is allocated differently from the other schema
1296   ** objects (using sqliteMalloc() directly, instead of sqlite3BtreeSchema()).
1297   ** So it needs to be freed here. Todo: Why not roll the temp schema into
1298   ** the same sqliteMalloc() as the one that allocates the database
1299   ** structure?
1300   */
1301   sqlite3DbFree(db, db->aDb[1].pSchema);
1302   sqlite3_mutex_leave(db->mutex);
1303   db->magic = SQLITE_MAGIC_CLOSED;
1304   sqlite3_mutex_free(db->mutex);
1305   assert( sqlite3LookasideUsed(db,0)==0 );
1306   if( db->lookaside.bMalloced ){
1307     sqlite3_free(db->lookaside.pStart);
1308   }
1309   sqlite3_free(db);
1310 }
1311 
1312 /*
1313 ** Rollback all database files.  If tripCode is not SQLITE_OK, then
1314 ** any write cursors are invalidated ("tripped" - as in "tripping a circuit
1315 ** breaker") and made to return tripCode if there are any further
1316 ** attempts to use that cursor.  Read cursors remain open and valid
1317 ** but are "saved" in case the table pages are moved around.
1318 */
1319 void sqlite3RollbackAll(sqlite3 *db, int tripCode){
1320   int i;
1321   int inTrans = 0;
1322   int schemaChange;
1323   assert( sqlite3_mutex_held(db->mutex) );
1324   sqlite3BeginBenignMalloc();
1325 
1326   /* Obtain all b-tree mutexes before making any calls to BtreeRollback().
1327   ** This is important in case the transaction being rolled back has
1328   ** modified the database schema. If the b-tree mutexes are not taken
1329   ** here, then another shared-cache connection might sneak in between
1330   ** the database rollback and schema reset, which can cause false
1331   ** corruption reports in some cases.  */
1332   sqlite3BtreeEnterAll(db);
1333   schemaChange = (db->mDbFlags & DBFLAG_SchemaChange)!=0 && db->init.busy==0;
1334 
1335   for(i=0; i<db->nDb; i++){
1336     Btree *p = db->aDb[i].pBt;
1337     if( p ){
1338       if( sqlite3BtreeIsInTrans(p) ){
1339         inTrans = 1;
1340       }
1341       sqlite3BtreeRollback(p, tripCode, !schemaChange);
1342     }
1343   }
1344   sqlite3VtabRollback(db);
1345   sqlite3EndBenignMalloc();
1346 
1347   if( schemaChange ){
1348     sqlite3ExpirePreparedStatements(db, 0);
1349     sqlite3ResetAllSchemasOfConnection(db);
1350   }
1351   sqlite3BtreeLeaveAll(db);
1352 
1353   /* Any deferred constraint violations have now been resolved. */
1354   db->nDeferredCons = 0;
1355   db->nDeferredImmCons = 0;
1356   db->flags &= ~(u64)SQLITE_DeferFKs;
1357 
1358   /* If one has been configured, invoke the rollback-hook callback */
1359   if( db->xRollbackCallback && (inTrans || !db->autoCommit) ){
1360     db->xRollbackCallback(db->pRollbackArg);
1361   }
1362 }
1363 
1364 /*
1365 ** Return a static string containing the name corresponding to the error code
1366 ** specified in the argument.
1367 */
1368 #if defined(SQLITE_NEED_ERR_NAME)
1369 const char *sqlite3ErrName(int rc){
1370   const char *zName = 0;
1371   int i, origRc = rc;
1372   for(i=0; i<2 && zName==0; i++, rc &= 0xff){
1373     switch( rc ){
1374       case SQLITE_OK:                 zName = "SQLITE_OK";                break;
1375       case SQLITE_ERROR:              zName = "SQLITE_ERROR";             break;
1376       case SQLITE_ERROR_SNAPSHOT:     zName = "SQLITE_ERROR_SNAPSHOT";    break;
1377       case SQLITE_INTERNAL:           zName = "SQLITE_INTERNAL";          break;
1378       case SQLITE_PERM:               zName = "SQLITE_PERM";              break;
1379       case SQLITE_ABORT:              zName = "SQLITE_ABORT";             break;
1380       case SQLITE_ABORT_ROLLBACK:     zName = "SQLITE_ABORT_ROLLBACK";    break;
1381       case SQLITE_BUSY:               zName = "SQLITE_BUSY";              break;
1382       case SQLITE_BUSY_RECOVERY:      zName = "SQLITE_BUSY_RECOVERY";     break;
1383       case SQLITE_BUSY_SNAPSHOT:      zName = "SQLITE_BUSY_SNAPSHOT";     break;
1384       case SQLITE_LOCKED:             zName = "SQLITE_LOCKED";            break;
1385       case SQLITE_LOCKED_SHAREDCACHE: zName = "SQLITE_LOCKED_SHAREDCACHE";break;
1386       case SQLITE_NOMEM:              zName = "SQLITE_NOMEM";             break;
1387       case SQLITE_READONLY:           zName = "SQLITE_READONLY";          break;
1388       case SQLITE_READONLY_RECOVERY:  zName = "SQLITE_READONLY_RECOVERY"; break;
1389       case SQLITE_READONLY_CANTINIT:  zName = "SQLITE_READONLY_CANTINIT"; break;
1390       case SQLITE_READONLY_ROLLBACK:  zName = "SQLITE_READONLY_ROLLBACK"; break;
1391       case SQLITE_READONLY_DBMOVED:   zName = "SQLITE_READONLY_DBMOVED";  break;
1392       case SQLITE_READONLY_DIRECTORY: zName = "SQLITE_READONLY_DIRECTORY";break;
1393       case SQLITE_INTERRUPT:          zName = "SQLITE_INTERRUPT";         break;
1394       case SQLITE_IOERR:              zName = "SQLITE_IOERR";             break;
1395       case SQLITE_IOERR_READ:         zName = "SQLITE_IOERR_READ";        break;
1396       case SQLITE_IOERR_SHORT_READ:   zName = "SQLITE_IOERR_SHORT_READ";  break;
1397       case SQLITE_IOERR_WRITE:        zName = "SQLITE_IOERR_WRITE";       break;
1398       case SQLITE_IOERR_FSYNC:        zName = "SQLITE_IOERR_FSYNC";       break;
1399       case SQLITE_IOERR_DIR_FSYNC:    zName = "SQLITE_IOERR_DIR_FSYNC";   break;
1400       case SQLITE_IOERR_TRUNCATE:     zName = "SQLITE_IOERR_TRUNCATE";    break;
1401       case SQLITE_IOERR_FSTAT:        zName = "SQLITE_IOERR_FSTAT";       break;
1402       case SQLITE_IOERR_UNLOCK:       zName = "SQLITE_IOERR_UNLOCK";      break;
1403       case SQLITE_IOERR_RDLOCK:       zName = "SQLITE_IOERR_RDLOCK";      break;
1404       case SQLITE_IOERR_DELETE:       zName = "SQLITE_IOERR_DELETE";      break;
1405       case SQLITE_IOERR_NOMEM:        zName = "SQLITE_IOERR_NOMEM";       break;
1406       case SQLITE_IOERR_ACCESS:       zName = "SQLITE_IOERR_ACCESS";      break;
1407       case SQLITE_IOERR_CHECKRESERVEDLOCK:
1408                                 zName = "SQLITE_IOERR_CHECKRESERVEDLOCK"; break;
1409       case SQLITE_IOERR_LOCK:         zName = "SQLITE_IOERR_LOCK";        break;
1410       case SQLITE_IOERR_CLOSE:        zName = "SQLITE_IOERR_CLOSE";       break;
1411       case SQLITE_IOERR_DIR_CLOSE:    zName = "SQLITE_IOERR_DIR_CLOSE";   break;
1412       case SQLITE_IOERR_SHMOPEN:      zName = "SQLITE_IOERR_SHMOPEN";     break;
1413       case SQLITE_IOERR_SHMSIZE:      zName = "SQLITE_IOERR_SHMSIZE";     break;
1414       case SQLITE_IOERR_SHMLOCK:      zName = "SQLITE_IOERR_SHMLOCK";     break;
1415       case SQLITE_IOERR_SHMMAP:       zName = "SQLITE_IOERR_SHMMAP";      break;
1416       case SQLITE_IOERR_SEEK:         zName = "SQLITE_IOERR_SEEK";        break;
1417       case SQLITE_IOERR_DELETE_NOENT: zName = "SQLITE_IOERR_DELETE_NOENT";break;
1418       case SQLITE_IOERR_MMAP:         zName = "SQLITE_IOERR_MMAP";        break;
1419       case SQLITE_IOERR_GETTEMPPATH:  zName = "SQLITE_IOERR_GETTEMPPATH"; break;
1420       case SQLITE_IOERR_CONVPATH:     zName = "SQLITE_IOERR_CONVPATH";    break;
1421       case SQLITE_CORRUPT:            zName = "SQLITE_CORRUPT";           break;
1422       case SQLITE_CORRUPT_VTAB:       zName = "SQLITE_CORRUPT_VTAB";      break;
1423       case SQLITE_NOTFOUND:           zName = "SQLITE_NOTFOUND";          break;
1424       case SQLITE_FULL:               zName = "SQLITE_FULL";              break;
1425       case SQLITE_CANTOPEN:           zName = "SQLITE_CANTOPEN";          break;
1426       case SQLITE_CANTOPEN_NOTEMPDIR: zName = "SQLITE_CANTOPEN_NOTEMPDIR";break;
1427       case SQLITE_CANTOPEN_ISDIR:     zName = "SQLITE_CANTOPEN_ISDIR";    break;
1428       case SQLITE_CANTOPEN_FULLPATH:  zName = "SQLITE_CANTOPEN_FULLPATH"; break;
1429       case SQLITE_CANTOPEN_CONVPATH:  zName = "SQLITE_CANTOPEN_CONVPATH"; break;
1430       case SQLITE_CANTOPEN_SYMLINK:   zName = "SQLITE_CANTOPEN_SYMLINK";  break;
1431       case SQLITE_PROTOCOL:           zName = "SQLITE_PROTOCOL";          break;
1432       case SQLITE_EMPTY:              zName = "SQLITE_EMPTY";             break;
1433       case SQLITE_SCHEMA:             zName = "SQLITE_SCHEMA";            break;
1434       case SQLITE_TOOBIG:             zName = "SQLITE_TOOBIG";            break;
1435       case SQLITE_CONSTRAINT:         zName = "SQLITE_CONSTRAINT";        break;
1436       case SQLITE_CONSTRAINT_UNIQUE:  zName = "SQLITE_CONSTRAINT_UNIQUE"; break;
1437       case SQLITE_CONSTRAINT_TRIGGER: zName = "SQLITE_CONSTRAINT_TRIGGER";break;
1438       case SQLITE_CONSTRAINT_FOREIGNKEY:
1439                                 zName = "SQLITE_CONSTRAINT_FOREIGNKEY";   break;
1440       case SQLITE_CONSTRAINT_CHECK:   zName = "SQLITE_CONSTRAINT_CHECK";  break;
1441       case SQLITE_CONSTRAINT_PRIMARYKEY:
1442                                 zName = "SQLITE_CONSTRAINT_PRIMARYKEY";   break;
1443       case SQLITE_CONSTRAINT_NOTNULL: zName = "SQLITE_CONSTRAINT_NOTNULL";break;
1444       case SQLITE_CONSTRAINT_COMMITHOOK:
1445                                 zName = "SQLITE_CONSTRAINT_COMMITHOOK";   break;
1446       case SQLITE_CONSTRAINT_VTAB:    zName = "SQLITE_CONSTRAINT_VTAB";   break;
1447       case SQLITE_CONSTRAINT_FUNCTION:
1448                                 zName = "SQLITE_CONSTRAINT_FUNCTION";     break;
1449       case SQLITE_CONSTRAINT_ROWID:   zName = "SQLITE_CONSTRAINT_ROWID";  break;
1450       case SQLITE_MISMATCH:           zName = "SQLITE_MISMATCH";          break;
1451       case SQLITE_MISUSE:             zName = "SQLITE_MISUSE";            break;
1452       case SQLITE_NOLFS:              zName = "SQLITE_NOLFS";             break;
1453       case SQLITE_AUTH:               zName = "SQLITE_AUTH";              break;
1454       case SQLITE_FORMAT:             zName = "SQLITE_FORMAT";            break;
1455       case SQLITE_RANGE:              zName = "SQLITE_RANGE";             break;
1456       case SQLITE_NOTADB:             zName = "SQLITE_NOTADB";            break;
1457       case SQLITE_ROW:                zName = "SQLITE_ROW";               break;
1458       case SQLITE_NOTICE:             zName = "SQLITE_NOTICE";            break;
1459       case SQLITE_NOTICE_RECOVER_WAL: zName = "SQLITE_NOTICE_RECOVER_WAL";break;
1460       case SQLITE_NOTICE_RECOVER_ROLLBACK:
1461                                 zName = "SQLITE_NOTICE_RECOVER_ROLLBACK"; break;
1462       case SQLITE_WARNING:            zName = "SQLITE_WARNING";           break;
1463       case SQLITE_WARNING_AUTOINDEX:  zName = "SQLITE_WARNING_AUTOINDEX"; break;
1464       case SQLITE_DONE:               zName = "SQLITE_DONE";              break;
1465     }
1466   }
1467   if( zName==0 ){
1468     static char zBuf[50];
1469     sqlite3_snprintf(sizeof(zBuf), zBuf, "SQLITE_UNKNOWN(%d)", origRc);
1470     zName = zBuf;
1471   }
1472   return zName;
1473 }
1474 #endif
1475 
1476 /*
1477 ** Return a static string that describes the kind of error specified in the
1478 ** argument.
1479 */
1480 const char *sqlite3ErrStr(int rc){
1481   static const char* const aMsg[] = {
1482     /* SQLITE_OK          */ "not an error",
1483     /* SQLITE_ERROR       */ "SQL logic error",
1484     /* SQLITE_INTERNAL    */ 0,
1485     /* SQLITE_PERM        */ "access permission denied",
1486     /* SQLITE_ABORT       */ "query aborted",
1487     /* SQLITE_BUSY        */ "database is locked",
1488     /* SQLITE_LOCKED      */ "database table is locked",
1489     /* SQLITE_NOMEM       */ "out of memory",
1490     /* SQLITE_READONLY    */ "attempt to write a readonly database",
1491     /* SQLITE_INTERRUPT   */ "interrupted",
1492     /* SQLITE_IOERR       */ "disk I/O error",
1493     /* SQLITE_CORRUPT     */ "database disk image is malformed",
1494     /* SQLITE_NOTFOUND    */ "unknown operation",
1495     /* SQLITE_FULL        */ "database or disk is full",
1496     /* SQLITE_CANTOPEN    */ "unable to open database file",
1497     /* SQLITE_PROTOCOL    */ "locking protocol",
1498     /* SQLITE_EMPTY       */ 0,
1499     /* SQLITE_SCHEMA      */ "database schema has changed",
1500     /* SQLITE_TOOBIG      */ "string or blob too big",
1501     /* SQLITE_CONSTRAINT  */ "constraint failed",
1502     /* SQLITE_MISMATCH    */ "datatype mismatch",
1503     /* SQLITE_MISUSE      */ "bad parameter or other API misuse",
1504 #ifdef SQLITE_DISABLE_LFS
1505     /* SQLITE_NOLFS       */ "large file support is disabled",
1506 #else
1507     /* SQLITE_NOLFS       */ 0,
1508 #endif
1509     /* SQLITE_AUTH        */ "authorization denied",
1510     /* SQLITE_FORMAT      */ 0,
1511     /* SQLITE_RANGE       */ "column index out of range",
1512     /* SQLITE_NOTADB      */ "file is not a database",
1513     /* SQLITE_NOTICE      */ "notification message",
1514     /* SQLITE_WARNING     */ "warning message",
1515   };
1516   const char *zErr = "unknown error";
1517   switch( rc ){
1518     case SQLITE_ABORT_ROLLBACK: {
1519       zErr = "abort due to ROLLBACK";
1520       break;
1521     }
1522     case SQLITE_ROW: {
1523       zErr = "another row available";
1524       break;
1525     }
1526     case SQLITE_DONE: {
1527       zErr = "no more rows available";
1528       break;
1529     }
1530     default: {
1531       rc &= 0xff;
1532       if( ALWAYS(rc>=0) && rc<ArraySize(aMsg) && aMsg[rc]!=0 ){
1533         zErr = aMsg[rc];
1534       }
1535       break;
1536     }
1537   }
1538   return zErr;
1539 }
1540 
1541 /*
1542 ** This routine implements a busy callback that sleeps and tries
1543 ** again until a timeout value is reached.  The timeout value is
1544 ** an integer number of milliseconds passed in as the first
1545 ** argument.
1546 **
1547 ** Return non-zero to retry the lock.  Return zero to stop trying
1548 ** and cause SQLite to return SQLITE_BUSY.
1549 */
1550 static int sqliteDefaultBusyCallback(
1551   void *ptr,               /* Database connection */
1552   int count,               /* Number of times table has been busy */
1553   sqlite3_file *pFile      /* The file on which the lock occurred */
1554 ){
1555 #if SQLITE_OS_WIN || HAVE_USLEEP
1556   /* This case is for systems that have support for sleeping for fractions of
1557   ** a second.  Examples:  All windows systems, unix systems with usleep() */
1558   static const u8 delays[] =
1559      { 1, 2, 5, 10, 15, 20, 25, 25,  25,  50,  50, 100 };
1560   static const u8 totals[] =
1561      { 0, 1, 3,  8, 18, 33, 53, 78, 103, 128, 178, 228 };
1562 # define NDELAY ArraySize(delays)
1563   sqlite3 *db = (sqlite3 *)ptr;
1564   int tmout = db->busyTimeout;
1565   int delay, prior;
1566 
1567 #ifdef SQLITE_ENABLE_SETLK_TIMEOUT
1568   if( sqlite3OsFileControl(pFile,SQLITE_FCNTL_LOCK_TIMEOUT,&tmout)==SQLITE_OK ){
1569     if( count ){
1570       tmout = 0;
1571       sqlite3OsFileControl(pFile, SQLITE_FCNTL_LOCK_TIMEOUT, &tmout);
1572       return 0;
1573     }else{
1574       return 1;
1575     }
1576   }
1577 #else
1578   UNUSED_PARAMETER(pFile);
1579 #endif
1580   assert( count>=0 );
1581   if( count < NDELAY ){
1582     delay = delays[count];
1583     prior = totals[count];
1584   }else{
1585     delay = delays[NDELAY-1];
1586     prior = totals[NDELAY-1] + delay*(count-(NDELAY-1));
1587   }
1588   if( prior + delay > tmout ){
1589     delay = tmout - prior;
1590     if( delay<=0 ) return 0;
1591   }
1592   sqlite3OsSleep(db->pVfs, delay*1000);
1593   return 1;
1594 #else
1595   /* This case for unix systems that lack usleep() support.  Sleeping
1596   ** must be done in increments of whole seconds */
1597   sqlite3 *db = (sqlite3 *)ptr;
1598   int tmout = ((sqlite3 *)ptr)->busyTimeout;
1599   UNUSED_PARAMETER(pFile);
1600   if( (count+1)*1000 > tmout ){
1601     return 0;
1602   }
1603   sqlite3OsSleep(db->pVfs, 1000000);
1604   return 1;
1605 #endif
1606 }
1607 
1608 /*
1609 ** Invoke the given busy handler.
1610 **
1611 ** This routine is called when an operation failed to acquire a
1612 ** lock on VFS file pFile.
1613 **
1614 ** If this routine returns non-zero, the lock is retried.  If it
1615 ** returns 0, the operation aborts with an SQLITE_BUSY error.
1616 */
1617 int sqlite3InvokeBusyHandler(BusyHandler *p, sqlite3_file *pFile){
1618   int rc;
1619   if( p->xBusyHandler==0 || p->nBusy<0 ) return 0;
1620   if( p->bExtraFileArg ){
1621     /* Add an extra parameter with the pFile pointer to the end of the
1622     ** callback argument list */
1623     int (*xTra)(void*,int,sqlite3_file*);
1624     xTra = (int(*)(void*,int,sqlite3_file*))p->xBusyHandler;
1625     rc = xTra(p->pBusyArg, p->nBusy, pFile);
1626   }else{
1627     /* Legacy style busy handler callback */
1628     rc = p->xBusyHandler(p->pBusyArg, p->nBusy);
1629   }
1630   if( rc==0 ){
1631     p->nBusy = -1;
1632   }else{
1633     p->nBusy++;
1634   }
1635   return rc;
1636 }
1637 
1638 /*
1639 ** This routine sets the busy callback for an Sqlite database to the
1640 ** given callback function with the given argument.
1641 */
1642 int sqlite3_busy_handler(
1643   sqlite3 *db,
1644   int (*xBusy)(void*,int),
1645   void *pArg
1646 ){
1647 #ifdef SQLITE_ENABLE_API_ARMOR
1648   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
1649 #endif
1650   sqlite3_mutex_enter(db->mutex);
1651   db->busyHandler.xBusyHandler = xBusy;
1652   db->busyHandler.pBusyArg = pArg;
1653   db->busyHandler.nBusy = 0;
1654   db->busyHandler.bExtraFileArg = 0;
1655   db->busyTimeout = 0;
1656   sqlite3_mutex_leave(db->mutex);
1657   return SQLITE_OK;
1658 }
1659 
1660 #ifndef SQLITE_OMIT_PROGRESS_CALLBACK
1661 /*
1662 ** This routine sets the progress callback for an Sqlite database to the
1663 ** given callback function with the given argument. The progress callback will
1664 ** be invoked every nOps opcodes.
1665 */
1666 void sqlite3_progress_handler(
1667   sqlite3 *db,
1668   int nOps,
1669   int (*xProgress)(void*),
1670   void *pArg
1671 ){
1672 #ifdef SQLITE_ENABLE_API_ARMOR
1673   if( !sqlite3SafetyCheckOk(db) ){
1674     (void)SQLITE_MISUSE_BKPT;
1675     return;
1676   }
1677 #endif
1678   sqlite3_mutex_enter(db->mutex);
1679   if( nOps>0 ){
1680     db->xProgress = xProgress;
1681     db->nProgressOps = (unsigned)nOps;
1682     db->pProgressArg = pArg;
1683   }else{
1684     db->xProgress = 0;
1685     db->nProgressOps = 0;
1686     db->pProgressArg = 0;
1687   }
1688   sqlite3_mutex_leave(db->mutex);
1689 }
1690 #endif
1691 
1692 
1693 /*
1694 ** This routine installs a default busy handler that waits for the
1695 ** specified number of milliseconds before returning 0.
1696 */
1697 int sqlite3_busy_timeout(sqlite3 *db, int ms){
1698 #ifdef SQLITE_ENABLE_API_ARMOR
1699   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
1700 #endif
1701   if( ms>0 ){
1702     sqlite3_busy_handler(db, (int(*)(void*,int))sqliteDefaultBusyCallback,
1703                              (void*)db);
1704     db->busyTimeout = ms;
1705     db->busyHandler.bExtraFileArg = 1;
1706   }else{
1707     sqlite3_busy_handler(db, 0, 0);
1708   }
1709   return SQLITE_OK;
1710 }
1711 
1712 /*
1713 ** Cause any pending operation to stop at its earliest opportunity.
1714 */
1715 void sqlite3_interrupt(sqlite3 *db){
1716 #ifdef SQLITE_ENABLE_API_ARMOR
1717   if( !sqlite3SafetyCheckOk(db) && (db==0 || db->magic!=SQLITE_MAGIC_ZOMBIE) ){
1718     (void)SQLITE_MISUSE_BKPT;
1719     return;
1720   }
1721 #endif
1722   db->u1.isInterrupted = 1;
1723 }
1724 
1725 
1726 /*
1727 ** This function is exactly the same as sqlite3_create_function(), except
1728 ** that it is designed to be called by internal code. The difference is
1729 ** that if a malloc() fails in sqlite3_create_function(), an error code
1730 ** is returned and the mallocFailed flag cleared.
1731 */
1732 int sqlite3CreateFunc(
1733   sqlite3 *db,
1734   const char *zFunctionName,
1735   int nArg,
1736   int enc,
1737   void *pUserData,
1738   void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
1739   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
1740   void (*xFinal)(sqlite3_context*),
1741   void (*xValue)(sqlite3_context*),
1742   void (*xInverse)(sqlite3_context*,int,sqlite3_value **),
1743   FuncDestructor *pDestructor
1744 ){
1745   FuncDef *p;
1746   int nName;
1747   int extraFlags;
1748 
1749   assert( sqlite3_mutex_held(db->mutex) );
1750   assert( xValue==0 || xSFunc==0 );
1751   if( zFunctionName==0                /* Must have a valid name */
1752    || (xSFunc!=0 && xFinal!=0)        /* Not both xSFunc and xFinal */
1753    || ((xFinal==0)!=(xStep==0))       /* Both or neither of xFinal and xStep */
1754    || ((xValue==0)!=(xInverse==0))    /* Both or neither of xValue, xInverse */
1755    || (nArg<-1 || nArg>SQLITE_MAX_FUNCTION_ARG)
1756    || (255<(nName = sqlite3Strlen30( zFunctionName)))
1757   ){
1758     return SQLITE_MISUSE_BKPT;
1759   }
1760 
1761   assert( SQLITE_FUNC_CONSTANT==SQLITE_DETERMINISTIC );
1762   assert( SQLITE_FUNC_DIRECT==SQLITE_DIRECTONLY );
1763   extraFlags = enc &  (SQLITE_DETERMINISTIC|SQLITE_DIRECTONLY|
1764                        SQLITE_SUBTYPE|SQLITE_INNOCUOUS);
1765   enc &= (SQLITE_FUNC_ENCMASK|SQLITE_ANY);
1766 
1767   /* The SQLITE_INNOCUOUS flag is the same bit as SQLITE_FUNC_UNSAFE.  But
1768   ** the meaning is inverted.  So flip the bit. */
1769   assert( SQLITE_FUNC_UNSAFE==SQLITE_INNOCUOUS );
1770   extraFlags ^= SQLITE_FUNC_UNSAFE;
1771 
1772 
1773 #ifndef SQLITE_OMIT_UTF16
1774   /* If SQLITE_UTF16 is specified as the encoding type, transform this
1775   ** to one of SQLITE_UTF16LE or SQLITE_UTF16BE using the
1776   ** SQLITE_UTF16NATIVE macro. SQLITE_UTF16 is not used internally.
1777   **
1778   ** If SQLITE_ANY is specified, add three versions of the function
1779   ** to the hash table.
1780   */
1781   if( enc==SQLITE_UTF16 ){
1782     enc = SQLITE_UTF16NATIVE;
1783   }else if( enc==SQLITE_ANY ){
1784     int rc;
1785     rc = sqlite3CreateFunc(db, zFunctionName, nArg,
1786          (SQLITE_UTF8|extraFlags)^SQLITE_FUNC_UNSAFE,
1787          pUserData, xSFunc, xStep, xFinal, xValue, xInverse, pDestructor);
1788     if( rc==SQLITE_OK ){
1789       rc = sqlite3CreateFunc(db, zFunctionName, nArg,
1790            (SQLITE_UTF16LE|extraFlags)^SQLITE_FUNC_UNSAFE,
1791            pUserData, xSFunc, xStep, xFinal, xValue, xInverse, pDestructor);
1792     }
1793     if( rc!=SQLITE_OK ){
1794       return rc;
1795     }
1796     enc = SQLITE_UTF16BE;
1797   }
1798 #else
1799   enc = SQLITE_UTF8;
1800 #endif
1801 
1802   /* Check if an existing function is being overridden or deleted. If so,
1803   ** and there are active VMs, then return SQLITE_BUSY. If a function
1804   ** is being overridden/deleted but there are no active VMs, allow the
1805   ** operation to continue but invalidate all precompiled statements.
1806   */
1807   p = sqlite3FindFunction(db, zFunctionName, nArg, (u8)enc, 0);
1808   if( p && (p->funcFlags & SQLITE_FUNC_ENCMASK)==(u32)enc && p->nArg==nArg ){
1809     if( db->nVdbeActive ){
1810       sqlite3ErrorWithMsg(db, SQLITE_BUSY,
1811         "unable to delete/modify user-function due to active statements");
1812       assert( !db->mallocFailed );
1813       return SQLITE_BUSY;
1814     }else{
1815       sqlite3ExpirePreparedStatements(db, 0);
1816     }
1817   }
1818 
1819   p = sqlite3FindFunction(db, zFunctionName, nArg, (u8)enc, 1);
1820   assert(p || db->mallocFailed);
1821   if( !p ){
1822     return SQLITE_NOMEM_BKPT;
1823   }
1824 
1825   /* If an older version of the function with a configured destructor is
1826   ** being replaced invoke the destructor function here. */
1827   functionDestroy(db, p);
1828 
1829   if( pDestructor ){
1830     pDestructor->nRef++;
1831   }
1832   p->u.pDestructor = pDestructor;
1833   p->funcFlags = (p->funcFlags & SQLITE_FUNC_ENCMASK) | extraFlags;
1834   testcase( p->funcFlags & SQLITE_DETERMINISTIC );
1835   testcase( p->funcFlags & SQLITE_DIRECTONLY );
1836   p->xSFunc = xSFunc ? xSFunc : xStep;
1837   p->xFinalize = xFinal;
1838   p->xValue = xValue;
1839   p->xInverse = xInverse;
1840   p->pUserData = pUserData;
1841   p->nArg = (u16)nArg;
1842   return SQLITE_OK;
1843 }
1844 
1845 /*
1846 ** Worker function used by utf-8 APIs that create new functions:
1847 **
1848 **    sqlite3_create_function()
1849 **    sqlite3_create_function_v2()
1850 **    sqlite3_create_window_function()
1851 */
1852 static int createFunctionApi(
1853   sqlite3 *db,
1854   const char *zFunc,
1855   int nArg,
1856   int enc,
1857   void *p,
1858   void (*xSFunc)(sqlite3_context*,int,sqlite3_value**),
1859   void (*xStep)(sqlite3_context*,int,sqlite3_value**),
1860   void (*xFinal)(sqlite3_context*),
1861   void (*xValue)(sqlite3_context*),
1862   void (*xInverse)(sqlite3_context*,int,sqlite3_value**),
1863   void(*xDestroy)(void*)
1864 ){
1865   int rc = SQLITE_ERROR;
1866   FuncDestructor *pArg = 0;
1867 
1868 #ifdef SQLITE_ENABLE_API_ARMOR
1869   if( !sqlite3SafetyCheckOk(db) ){
1870     return SQLITE_MISUSE_BKPT;
1871   }
1872 #endif
1873   sqlite3_mutex_enter(db->mutex);
1874   if( xDestroy ){
1875     pArg = (FuncDestructor *)sqlite3Malloc(sizeof(FuncDestructor));
1876     if( !pArg ){
1877       sqlite3OomFault(db);
1878       xDestroy(p);
1879       goto out;
1880     }
1881     pArg->nRef = 0;
1882     pArg->xDestroy = xDestroy;
1883     pArg->pUserData = p;
1884   }
1885   rc = sqlite3CreateFunc(db, zFunc, nArg, enc, p,
1886       xSFunc, xStep, xFinal, xValue, xInverse, pArg
1887   );
1888   if( pArg && pArg->nRef==0 ){
1889     assert( rc!=SQLITE_OK );
1890     xDestroy(p);
1891     sqlite3_free(pArg);
1892   }
1893 
1894  out:
1895   rc = sqlite3ApiExit(db, rc);
1896   sqlite3_mutex_leave(db->mutex);
1897   return rc;
1898 }
1899 
1900 /*
1901 ** Create new user functions.
1902 */
1903 int sqlite3_create_function(
1904   sqlite3 *db,
1905   const char *zFunc,
1906   int nArg,
1907   int enc,
1908   void *p,
1909   void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
1910   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
1911   void (*xFinal)(sqlite3_context*)
1912 ){
1913   return createFunctionApi(db, zFunc, nArg, enc, p, xSFunc, xStep,
1914                                     xFinal, 0, 0, 0);
1915 }
1916 int sqlite3_create_function_v2(
1917   sqlite3 *db,
1918   const char *zFunc,
1919   int nArg,
1920   int enc,
1921   void *p,
1922   void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
1923   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
1924   void (*xFinal)(sqlite3_context*),
1925   void (*xDestroy)(void *)
1926 ){
1927   return createFunctionApi(db, zFunc, nArg, enc, p, xSFunc, xStep,
1928                                     xFinal, 0, 0, xDestroy);
1929 }
1930 int sqlite3_create_window_function(
1931   sqlite3 *db,
1932   const char *zFunc,
1933   int nArg,
1934   int enc,
1935   void *p,
1936   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
1937   void (*xFinal)(sqlite3_context*),
1938   void (*xValue)(sqlite3_context*),
1939   void (*xInverse)(sqlite3_context*,int,sqlite3_value **),
1940   void (*xDestroy)(void *)
1941 ){
1942   return createFunctionApi(db, zFunc, nArg, enc, p, 0, xStep,
1943                                     xFinal, xValue, xInverse, xDestroy);
1944 }
1945 
1946 #ifndef SQLITE_OMIT_UTF16
1947 int sqlite3_create_function16(
1948   sqlite3 *db,
1949   const void *zFunctionName,
1950   int nArg,
1951   int eTextRep,
1952   void *p,
1953   void (*xSFunc)(sqlite3_context*,int,sqlite3_value**),
1954   void (*xStep)(sqlite3_context*,int,sqlite3_value**),
1955   void (*xFinal)(sqlite3_context*)
1956 ){
1957   int rc;
1958   char *zFunc8;
1959 
1960 #ifdef SQLITE_ENABLE_API_ARMOR
1961   if( !sqlite3SafetyCheckOk(db) || zFunctionName==0 ) return SQLITE_MISUSE_BKPT;
1962 #endif
1963   sqlite3_mutex_enter(db->mutex);
1964   assert( !db->mallocFailed );
1965   zFunc8 = sqlite3Utf16to8(db, zFunctionName, -1, SQLITE_UTF16NATIVE);
1966   rc = sqlite3CreateFunc(db, zFunc8, nArg, eTextRep, p, xSFunc,xStep,xFinal,0,0,0);
1967   sqlite3DbFree(db, zFunc8);
1968   rc = sqlite3ApiExit(db, rc);
1969   sqlite3_mutex_leave(db->mutex);
1970   return rc;
1971 }
1972 #endif
1973 
1974 
1975 /*
1976 ** The following is the implementation of an SQL function that always
1977 ** fails with an error message stating that the function is used in the
1978 ** wrong context.  The sqlite3_overload_function() API might construct
1979 ** SQL function that use this routine so that the functions will exist
1980 ** for name resolution but are actually overloaded by the xFindFunction
1981 ** method of virtual tables.
1982 */
1983 static void sqlite3InvalidFunction(
1984   sqlite3_context *context,  /* The function calling context */
1985   int NotUsed,               /* Number of arguments to the function */
1986   sqlite3_value **NotUsed2   /* Value of each argument */
1987 ){
1988   const char *zName = (const char*)sqlite3_user_data(context);
1989   char *zErr;
1990   UNUSED_PARAMETER2(NotUsed, NotUsed2);
1991   zErr = sqlite3_mprintf(
1992       "unable to use function %s in the requested context", zName);
1993   sqlite3_result_error(context, zErr, -1);
1994   sqlite3_free(zErr);
1995 }
1996 
1997 /*
1998 ** Declare that a function has been overloaded by a virtual table.
1999 **
2000 ** If the function already exists as a regular global function, then
2001 ** this routine is a no-op.  If the function does not exist, then create
2002 ** a new one that always throws a run-time error.
2003 **
2004 ** When virtual tables intend to provide an overloaded function, they
2005 ** should call this routine to make sure the global function exists.
2006 ** A global function must exist in order for name resolution to work
2007 ** properly.
2008 */
2009 int sqlite3_overload_function(
2010   sqlite3 *db,
2011   const char *zName,
2012   int nArg
2013 ){
2014   int rc;
2015   char *zCopy;
2016 
2017 #ifdef SQLITE_ENABLE_API_ARMOR
2018   if( !sqlite3SafetyCheckOk(db) || zName==0 || nArg<-2 ){
2019     return SQLITE_MISUSE_BKPT;
2020   }
2021 #endif
2022   sqlite3_mutex_enter(db->mutex);
2023   rc = sqlite3FindFunction(db, zName, nArg, SQLITE_UTF8, 0)!=0;
2024   sqlite3_mutex_leave(db->mutex);
2025   if( rc ) return SQLITE_OK;
2026   zCopy = sqlite3_mprintf(zName);
2027   if( zCopy==0 ) return SQLITE_NOMEM;
2028   return sqlite3_create_function_v2(db, zName, nArg, SQLITE_UTF8,
2029                            zCopy, sqlite3InvalidFunction, 0, 0, sqlite3_free);
2030 }
2031 
2032 #ifndef SQLITE_OMIT_TRACE
2033 /*
2034 ** Register a trace function.  The pArg from the previously registered trace
2035 ** is returned.
2036 **
2037 ** A NULL trace function means that no tracing is executes.  A non-NULL
2038 ** trace is a pointer to a function that is invoked at the start of each
2039 ** SQL statement.
2040 */
2041 #ifndef SQLITE_OMIT_DEPRECATED
2042 void *sqlite3_trace(sqlite3 *db, void(*xTrace)(void*,const char*), void *pArg){
2043   void *pOld;
2044 
2045 #ifdef SQLITE_ENABLE_API_ARMOR
2046   if( !sqlite3SafetyCheckOk(db) ){
2047     (void)SQLITE_MISUSE_BKPT;
2048     return 0;
2049   }
2050 #endif
2051   sqlite3_mutex_enter(db->mutex);
2052   pOld = db->pTraceArg;
2053   db->mTrace = xTrace ? SQLITE_TRACE_LEGACY : 0;
2054   db->xTrace = (int(*)(u32,void*,void*,void*))xTrace;
2055   db->pTraceArg = pArg;
2056   sqlite3_mutex_leave(db->mutex);
2057   return pOld;
2058 }
2059 #endif /* SQLITE_OMIT_DEPRECATED */
2060 
2061 /* Register a trace callback using the version-2 interface.
2062 */
2063 int sqlite3_trace_v2(
2064   sqlite3 *db,                               /* Trace this connection */
2065   unsigned mTrace,                           /* Mask of events to be traced */
2066   int(*xTrace)(unsigned,void*,void*,void*),  /* Callback to invoke */
2067   void *pArg                                 /* Context */
2068 ){
2069 #ifdef SQLITE_ENABLE_API_ARMOR
2070   if( !sqlite3SafetyCheckOk(db) ){
2071     return SQLITE_MISUSE_BKPT;
2072   }
2073 #endif
2074   sqlite3_mutex_enter(db->mutex);
2075   if( mTrace==0 ) xTrace = 0;
2076   if( xTrace==0 ) mTrace = 0;
2077   db->mTrace = mTrace;
2078   db->xTrace = xTrace;
2079   db->pTraceArg = pArg;
2080   sqlite3_mutex_leave(db->mutex);
2081   return SQLITE_OK;
2082 }
2083 
2084 #ifndef SQLITE_OMIT_DEPRECATED
2085 /*
2086 ** Register a profile function.  The pArg from the previously registered
2087 ** profile function is returned.
2088 **
2089 ** A NULL profile function means that no profiling is executes.  A non-NULL
2090 ** profile is a pointer to a function that is invoked at the conclusion of
2091 ** each SQL statement that is run.
2092 */
2093 void *sqlite3_profile(
2094   sqlite3 *db,
2095   void (*xProfile)(void*,const char*,sqlite_uint64),
2096   void *pArg
2097 ){
2098   void *pOld;
2099 
2100 #ifdef SQLITE_ENABLE_API_ARMOR
2101   if( !sqlite3SafetyCheckOk(db) ){
2102     (void)SQLITE_MISUSE_BKPT;
2103     return 0;
2104   }
2105 #endif
2106   sqlite3_mutex_enter(db->mutex);
2107   pOld = db->pProfileArg;
2108   db->xProfile = xProfile;
2109   db->pProfileArg = pArg;
2110   db->mTrace &= SQLITE_TRACE_NONLEGACY_MASK;
2111   if( db->xProfile ) db->mTrace |= SQLITE_TRACE_XPROFILE;
2112   sqlite3_mutex_leave(db->mutex);
2113   return pOld;
2114 }
2115 #endif /* SQLITE_OMIT_DEPRECATED */
2116 #endif /* SQLITE_OMIT_TRACE */
2117 
2118 /*
2119 ** Register a function to be invoked when a transaction commits.
2120 ** If the invoked function returns non-zero, then the commit becomes a
2121 ** rollback.
2122 */
2123 void *sqlite3_commit_hook(
2124   sqlite3 *db,              /* Attach the hook to this database */
2125   int (*xCallback)(void*),  /* Function to invoke on each commit */
2126   void *pArg                /* Argument to the function */
2127 ){
2128   void *pOld;
2129 
2130 #ifdef SQLITE_ENABLE_API_ARMOR
2131   if( !sqlite3SafetyCheckOk(db) ){
2132     (void)SQLITE_MISUSE_BKPT;
2133     return 0;
2134   }
2135 #endif
2136   sqlite3_mutex_enter(db->mutex);
2137   pOld = db->pCommitArg;
2138   db->xCommitCallback = xCallback;
2139   db->pCommitArg = pArg;
2140   sqlite3_mutex_leave(db->mutex);
2141   return pOld;
2142 }
2143 
2144 /*
2145 ** Register a callback to be invoked each time a row is updated,
2146 ** inserted or deleted using this database connection.
2147 */
2148 void *sqlite3_update_hook(
2149   sqlite3 *db,              /* Attach the hook to this database */
2150   void (*xCallback)(void*,int,char const *,char const *,sqlite_int64),
2151   void *pArg                /* Argument to the function */
2152 ){
2153   void *pRet;
2154 
2155 #ifdef SQLITE_ENABLE_API_ARMOR
2156   if( !sqlite3SafetyCheckOk(db) ){
2157     (void)SQLITE_MISUSE_BKPT;
2158     return 0;
2159   }
2160 #endif
2161   sqlite3_mutex_enter(db->mutex);
2162   pRet = db->pUpdateArg;
2163   db->xUpdateCallback = xCallback;
2164   db->pUpdateArg = pArg;
2165   sqlite3_mutex_leave(db->mutex);
2166   return pRet;
2167 }
2168 
2169 /*
2170 ** Register a callback to be invoked each time a transaction is rolled
2171 ** back by this database connection.
2172 */
2173 void *sqlite3_rollback_hook(
2174   sqlite3 *db,              /* Attach the hook to this database */
2175   void (*xCallback)(void*), /* Callback function */
2176   void *pArg                /* Argument to the function */
2177 ){
2178   void *pRet;
2179 
2180 #ifdef SQLITE_ENABLE_API_ARMOR
2181   if( !sqlite3SafetyCheckOk(db) ){
2182     (void)SQLITE_MISUSE_BKPT;
2183     return 0;
2184   }
2185 #endif
2186   sqlite3_mutex_enter(db->mutex);
2187   pRet = db->pRollbackArg;
2188   db->xRollbackCallback = xCallback;
2189   db->pRollbackArg = pArg;
2190   sqlite3_mutex_leave(db->mutex);
2191   return pRet;
2192 }
2193 
2194 #ifdef SQLITE_ENABLE_PREUPDATE_HOOK
2195 /*
2196 ** Register a callback to be invoked each time a row is updated,
2197 ** inserted or deleted using this database connection.
2198 */
2199 void *sqlite3_preupdate_hook(
2200   sqlite3 *db,              /* Attach the hook to this database */
2201   void(*xCallback)(         /* Callback function */
2202     void*,sqlite3*,int,char const*,char const*,sqlite3_int64,sqlite3_int64),
2203   void *pArg                /* First callback argument */
2204 ){
2205   void *pRet;
2206   sqlite3_mutex_enter(db->mutex);
2207   pRet = db->pPreUpdateArg;
2208   db->xPreUpdateCallback = xCallback;
2209   db->pPreUpdateArg = pArg;
2210   sqlite3_mutex_leave(db->mutex);
2211   return pRet;
2212 }
2213 #endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
2214 
2215 #ifndef SQLITE_OMIT_WAL
2216 /*
2217 ** The sqlite3_wal_hook() callback registered by sqlite3_wal_autocheckpoint().
2218 ** Invoke sqlite3_wal_checkpoint if the number of frames in the log file
2219 ** is greater than sqlite3.pWalArg cast to an integer (the value configured by
2220 ** wal_autocheckpoint()).
2221 */
2222 int sqlite3WalDefaultHook(
2223   void *pClientData,     /* Argument */
2224   sqlite3 *db,           /* Connection */
2225   const char *zDb,       /* Database */
2226   int nFrame             /* Size of WAL */
2227 ){
2228   if( nFrame>=SQLITE_PTR_TO_INT(pClientData) ){
2229     sqlite3BeginBenignMalloc();
2230     sqlite3_wal_checkpoint(db, zDb);
2231     sqlite3EndBenignMalloc();
2232   }
2233   return SQLITE_OK;
2234 }
2235 #endif /* SQLITE_OMIT_WAL */
2236 
2237 /*
2238 ** Configure an sqlite3_wal_hook() callback to automatically checkpoint
2239 ** a database after committing a transaction if there are nFrame or
2240 ** more frames in the log file. Passing zero or a negative value as the
2241 ** nFrame parameter disables automatic checkpoints entirely.
2242 **
2243 ** The callback registered by this function replaces any existing callback
2244 ** registered using sqlite3_wal_hook(). Likewise, registering a callback
2245 ** using sqlite3_wal_hook() disables the automatic checkpoint mechanism
2246 ** configured by this function.
2247 */
2248 int sqlite3_wal_autocheckpoint(sqlite3 *db, int nFrame){
2249 #ifdef SQLITE_OMIT_WAL
2250   UNUSED_PARAMETER(db);
2251   UNUSED_PARAMETER(nFrame);
2252 #else
2253 #ifdef SQLITE_ENABLE_API_ARMOR
2254   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
2255 #endif
2256   if( nFrame>0 ){
2257     sqlite3_wal_hook(db, sqlite3WalDefaultHook, SQLITE_INT_TO_PTR(nFrame));
2258   }else{
2259     sqlite3_wal_hook(db, 0, 0);
2260   }
2261 #endif
2262   return SQLITE_OK;
2263 }
2264 
2265 /*
2266 ** Register a callback to be invoked each time a transaction is written
2267 ** into the write-ahead-log by this database connection.
2268 */
2269 void *sqlite3_wal_hook(
2270   sqlite3 *db,                    /* Attach the hook to this db handle */
2271   int(*xCallback)(void *, sqlite3*, const char*, int),
2272   void *pArg                      /* First argument passed to xCallback() */
2273 ){
2274 #ifndef SQLITE_OMIT_WAL
2275   void *pRet;
2276 #ifdef SQLITE_ENABLE_API_ARMOR
2277   if( !sqlite3SafetyCheckOk(db) ){
2278     (void)SQLITE_MISUSE_BKPT;
2279     return 0;
2280   }
2281 #endif
2282   sqlite3_mutex_enter(db->mutex);
2283   pRet = db->pWalArg;
2284   db->xWalCallback = xCallback;
2285   db->pWalArg = pArg;
2286   sqlite3_mutex_leave(db->mutex);
2287   return pRet;
2288 #else
2289   return 0;
2290 #endif
2291 }
2292 
2293 /*
2294 ** Checkpoint database zDb.
2295 */
2296 int sqlite3_wal_checkpoint_v2(
2297   sqlite3 *db,                    /* Database handle */
2298   const char *zDb,                /* Name of attached database (or NULL) */
2299   int eMode,                      /* SQLITE_CHECKPOINT_* value */
2300   int *pnLog,                     /* OUT: Size of WAL log in frames */
2301   int *pnCkpt                     /* OUT: Total number of frames checkpointed */
2302 ){
2303 #ifdef SQLITE_OMIT_WAL
2304   return SQLITE_OK;
2305 #else
2306   int rc;                         /* Return code */
2307   int iDb = SQLITE_MAX_ATTACHED;  /* sqlite3.aDb[] index of db to checkpoint */
2308 
2309 #ifdef SQLITE_ENABLE_API_ARMOR
2310   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
2311 #endif
2312 
2313   /* Initialize the output variables to -1 in case an error occurs. */
2314   if( pnLog ) *pnLog = -1;
2315   if( pnCkpt ) *pnCkpt = -1;
2316 
2317   assert( SQLITE_CHECKPOINT_PASSIVE==0 );
2318   assert( SQLITE_CHECKPOINT_FULL==1 );
2319   assert( SQLITE_CHECKPOINT_RESTART==2 );
2320   assert( SQLITE_CHECKPOINT_TRUNCATE==3 );
2321   if( eMode<SQLITE_CHECKPOINT_PASSIVE || eMode>SQLITE_CHECKPOINT_TRUNCATE ){
2322     /* EVIDENCE-OF: R-03996-12088 The M parameter must be a valid checkpoint
2323     ** mode: */
2324     return SQLITE_MISUSE;
2325   }
2326 
2327   sqlite3_mutex_enter(db->mutex);
2328   if( zDb && zDb[0] ){
2329     iDb = sqlite3FindDbName(db, zDb);
2330   }
2331   if( iDb<0 ){
2332     rc = SQLITE_ERROR;
2333     sqlite3ErrorWithMsg(db, SQLITE_ERROR, "unknown database: %s", zDb);
2334   }else{
2335     db->busyHandler.nBusy = 0;
2336     rc = sqlite3Checkpoint(db, iDb, eMode, pnLog, pnCkpt);
2337     sqlite3Error(db, rc);
2338   }
2339   rc = sqlite3ApiExit(db, rc);
2340 
2341   /* If there are no active statements, clear the interrupt flag at this
2342   ** point.  */
2343   if( db->nVdbeActive==0 ){
2344     db->u1.isInterrupted = 0;
2345   }
2346 
2347   sqlite3_mutex_leave(db->mutex);
2348   return rc;
2349 #endif
2350 }
2351 
2352 
2353 /*
2354 ** Checkpoint database zDb. If zDb is NULL, or if the buffer zDb points
2355 ** to contains a zero-length string, all attached databases are
2356 ** checkpointed.
2357 */
2358 int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb){
2359   /* EVIDENCE-OF: R-41613-20553 The sqlite3_wal_checkpoint(D,X) is equivalent to
2360   ** sqlite3_wal_checkpoint_v2(D,X,SQLITE_CHECKPOINT_PASSIVE,0,0). */
2361   return sqlite3_wal_checkpoint_v2(db,zDb,SQLITE_CHECKPOINT_PASSIVE,0,0);
2362 }
2363 
2364 #ifndef SQLITE_OMIT_WAL
2365 /*
2366 ** Run a checkpoint on database iDb. This is a no-op if database iDb is
2367 ** not currently open in WAL mode.
2368 **
2369 ** If a transaction is open on the database being checkpointed, this
2370 ** function returns SQLITE_LOCKED and a checkpoint is not attempted. If
2371 ** an error occurs while running the checkpoint, an SQLite error code is
2372 ** returned (i.e. SQLITE_IOERR). Otherwise, SQLITE_OK.
2373 **
2374 ** The mutex on database handle db should be held by the caller. The mutex
2375 ** associated with the specific b-tree being checkpointed is taken by
2376 ** this function while the checkpoint is running.
2377 **
2378 ** If iDb is passed SQLITE_MAX_ATTACHED, then all attached databases are
2379 ** checkpointed. If an error is encountered it is returned immediately -
2380 ** no attempt is made to checkpoint any remaining databases.
2381 **
2382 ** Parameter eMode is one of SQLITE_CHECKPOINT_PASSIVE, FULL, RESTART
2383 ** or TRUNCATE.
2384 */
2385 int sqlite3Checkpoint(sqlite3 *db, int iDb, int eMode, int *pnLog, int *pnCkpt){
2386   int rc = SQLITE_OK;             /* Return code */
2387   int i;                          /* Used to iterate through attached dbs */
2388   int bBusy = 0;                  /* True if SQLITE_BUSY has been encountered */
2389 
2390   assert( sqlite3_mutex_held(db->mutex) );
2391   assert( !pnLog || *pnLog==-1 );
2392   assert( !pnCkpt || *pnCkpt==-1 );
2393 
2394   for(i=0; i<db->nDb && rc==SQLITE_OK; i++){
2395     if( i==iDb || iDb==SQLITE_MAX_ATTACHED ){
2396       rc = sqlite3BtreeCheckpoint(db->aDb[i].pBt, eMode, pnLog, pnCkpt);
2397       pnLog = 0;
2398       pnCkpt = 0;
2399       if( rc==SQLITE_BUSY ){
2400         bBusy = 1;
2401         rc = SQLITE_OK;
2402       }
2403     }
2404   }
2405 
2406   return (rc==SQLITE_OK && bBusy) ? SQLITE_BUSY : rc;
2407 }
2408 #endif /* SQLITE_OMIT_WAL */
2409 
2410 /*
2411 ** This function returns true if main-memory should be used instead of
2412 ** a temporary file for transient pager files and statement journals.
2413 ** The value returned depends on the value of db->temp_store (runtime
2414 ** parameter) and the compile time value of SQLITE_TEMP_STORE. The
2415 ** following table describes the relationship between these two values
2416 ** and this functions return value.
2417 **
2418 **   SQLITE_TEMP_STORE     db->temp_store     Location of temporary database
2419 **   -----------------     --------------     ------------------------------
2420 **   0                     any                file      (return 0)
2421 **   1                     1                  file      (return 0)
2422 **   1                     2                  memory    (return 1)
2423 **   1                     0                  file      (return 0)
2424 **   2                     1                  file      (return 0)
2425 **   2                     2                  memory    (return 1)
2426 **   2                     0                  memory    (return 1)
2427 **   3                     any                memory    (return 1)
2428 */
2429 int sqlite3TempInMemory(const sqlite3 *db){
2430 #if SQLITE_TEMP_STORE==1
2431   return ( db->temp_store==2 );
2432 #endif
2433 #if SQLITE_TEMP_STORE==2
2434   return ( db->temp_store!=1 );
2435 #endif
2436 #if SQLITE_TEMP_STORE==3
2437   UNUSED_PARAMETER(db);
2438   return 1;
2439 #endif
2440 #if SQLITE_TEMP_STORE<1 || SQLITE_TEMP_STORE>3
2441   UNUSED_PARAMETER(db);
2442   return 0;
2443 #endif
2444 }
2445 
2446 /*
2447 ** Return UTF-8 encoded English language explanation of the most recent
2448 ** error.
2449 */
2450 const char *sqlite3_errmsg(sqlite3 *db){
2451   const char *z;
2452   if( !db ){
2453     return sqlite3ErrStr(SQLITE_NOMEM_BKPT);
2454   }
2455   if( !sqlite3SafetyCheckSickOrOk(db) ){
2456     return sqlite3ErrStr(SQLITE_MISUSE_BKPT);
2457   }
2458   sqlite3_mutex_enter(db->mutex);
2459   if( db->mallocFailed ){
2460     z = sqlite3ErrStr(SQLITE_NOMEM_BKPT);
2461   }else{
2462     testcase( db->pErr==0 );
2463     z = db->errCode ? (char*)sqlite3_value_text(db->pErr) : 0;
2464     assert( !db->mallocFailed );
2465     if( z==0 ){
2466       z = sqlite3ErrStr(db->errCode);
2467     }
2468   }
2469   sqlite3_mutex_leave(db->mutex);
2470   return z;
2471 }
2472 
2473 #ifndef SQLITE_OMIT_UTF16
2474 /*
2475 ** Return UTF-16 encoded English language explanation of the most recent
2476 ** error.
2477 */
2478 const void *sqlite3_errmsg16(sqlite3 *db){
2479   static const u16 outOfMem[] = {
2480     'o', 'u', 't', ' ', 'o', 'f', ' ', 'm', 'e', 'm', 'o', 'r', 'y', 0
2481   };
2482   static const u16 misuse[] = {
2483     'b', 'a', 'd', ' ', 'p', 'a', 'r', 'a', 'm', 'e', 't', 'e', 'r', ' ',
2484     'o', 'r', ' ', 'o', 't', 'h', 'e', 'r', ' ', 'A', 'P', 'I', ' ',
2485     'm', 'i', 's', 'u', 's', 'e', 0
2486   };
2487 
2488   const void *z;
2489   if( !db ){
2490     return (void *)outOfMem;
2491   }
2492   if( !sqlite3SafetyCheckSickOrOk(db) ){
2493     return (void *)misuse;
2494   }
2495   sqlite3_mutex_enter(db->mutex);
2496   if( db->mallocFailed ){
2497     z = (void *)outOfMem;
2498   }else{
2499     z = sqlite3_value_text16(db->pErr);
2500     if( z==0 ){
2501       sqlite3ErrorWithMsg(db, db->errCode, sqlite3ErrStr(db->errCode));
2502       z = sqlite3_value_text16(db->pErr);
2503     }
2504     /* A malloc() may have failed within the call to sqlite3_value_text16()
2505     ** above. If this is the case, then the db->mallocFailed flag needs to
2506     ** be cleared before returning. Do this directly, instead of via
2507     ** sqlite3ApiExit(), to avoid setting the database handle error message.
2508     */
2509     sqlite3OomClear(db);
2510   }
2511   sqlite3_mutex_leave(db->mutex);
2512   return z;
2513 }
2514 #endif /* SQLITE_OMIT_UTF16 */
2515 
2516 /*
2517 ** Return the most recent error code generated by an SQLite routine. If NULL is
2518 ** passed to this function, we assume a malloc() failed during sqlite3_open().
2519 */
2520 int sqlite3_errcode(sqlite3 *db){
2521   if( db && !sqlite3SafetyCheckSickOrOk(db) ){
2522     return SQLITE_MISUSE_BKPT;
2523   }
2524   if( !db || db->mallocFailed ){
2525     return SQLITE_NOMEM_BKPT;
2526   }
2527   return db->errCode & db->errMask;
2528 }
2529 int sqlite3_extended_errcode(sqlite3 *db){
2530   if( db && !sqlite3SafetyCheckSickOrOk(db) ){
2531     return SQLITE_MISUSE_BKPT;
2532   }
2533   if( !db || db->mallocFailed ){
2534     return SQLITE_NOMEM_BKPT;
2535   }
2536   return db->errCode;
2537 }
2538 int sqlite3_system_errno(sqlite3 *db){
2539   return db ? db->iSysErrno : 0;
2540 }
2541 
2542 /*
2543 ** Return a string that describes the kind of error specified in the
2544 ** argument.  For now, this simply calls the internal sqlite3ErrStr()
2545 ** function.
2546 */
2547 const char *sqlite3_errstr(int rc){
2548   return sqlite3ErrStr(rc);
2549 }
2550 
2551 /*
2552 ** Create a new collating function for database "db".  The name is zName
2553 ** and the encoding is enc.
2554 */
2555 static int createCollation(
2556   sqlite3* db,
2557   const char *zName,
2558   u8 enc,
2559   void* pCtx,
2560   int(*xCompare)(void*,int,const void*,int,const void*),
2561   void(*xDel)(void*)
2562 ){
2563   CollSeq *pColl;
2564   int enc2;
2565 
2566   assert( sqlite3_mutex_held(db->mutex) );
2567 
2568   /* If SQLITE_UTF16 is specified as the encoding type, transform this
2569   ** to one of SQLITE_UTF16LE or SQLITE_UTF16BE using the
2570   ** SQLITE_UTF16NATIVE macro. SQLITE_UTF16 is not used internally.
2571   */
2572   enc2 = enc;
2573   testcase( enc2==SQLITE_UTF16 );
2574   testcase( enc2==SQLITE_UTF16_ALIGNED );
2575   if( enc2==SQLITE_UTF16 || enc2==SQLITE_UTF16_ALIGNED ){
2576     enc2 = SQLITE_UTF16NATIVE;
2577   }
2578   if( enc2<SQLITE_UTF8 || enc2>SQLITE_UTF16BE ){
2579     return SQLITE_MISUSE_BKPT;
2580   }
2581 
2582   /* Check if this call is removing or replacing an existing collation
2583   ** sequence. If so, and there are active VMs, return busy. If there
2584   ** are no active VMs, invalidate any pre-compiled statements.
2585   */
2586   pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, 0);
2587   if( pColl && pColl->xCmp ){
2588     if( db->nVdbeActive ){
2589       sqlite3ErrorWithMsg(db, SQLITE_BUSY,
2590         "unable to delete/modify collation sequence due to active statements");
2591       return SQLITE_BUSY;
2592     }
2593     sqlite3ExpirePreparedStatements(db, 0);
2594 
2595     /* If collation sequence pColl was created directly by a call to
2596     ** sqlite3_create_collation, and not generated by synthCollSeq(),
2597     ** then any copies made by synthCollSeq() need to be invalidated.
2598     ** Also, collation destructor - CollSeq.xDel() - function may need
2599     ** to be called.
2600     */
2601     if( (pColl->enc & ~SQLITE_UTF16_ALIGNED)==enc2 ){
2602       CollSeq *aColl = sqlite3HashFind(&db->aCollSeq, zName);
2603       int j;
2604       for(j=0; j<3; j++){
2605         CollSeq *p = &aColl[j];
2606         if( p->enc==pColl->enc ){
2607           if( p->xDel ){
2608             p->xDel(p->pUser);
2609           }
2610           p->xCmp = 0;
2611         }
2612       }
2613     }
2614   }
2615 
2616   pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, 1);
2617   if( pColl==0 ) return SQLITE_NOMEM_BKPT;
2618   pColl->xCmp = xCompare;
2619   pColl->pUser = pCtx;
2620   pColl->xDel = xDel;
2621   pColl->enc = (u8)(enc2 | (enc & SQLITE_UTF16_ALIGNED));
2622   sqlite3Error(db, SQLITE_OK);
2623   return SQLITE_OK;
2624 }
2625 
2626 
2627 /*
2628 ** This array defines hard upper bounds on limit values.  The
2629 ** initializer must be kept in sync with the SQLITE_LIMIT_*
2630 ** #defines in sqlite3.h.
2631 */
2632 static const int aHardLimit[] = {
2633   SQLITE_MAX_LENGTH,
2634   SQLITE_MAX_SQL_LENGTH,
2635   SQLITE_MAX_COLUMN,
2636   SQLITE_MAX_EXPR_DEPTH,
2637   SQLITE_MAX_COMPOUND_SELECT,
2638   SQLITE_MAX_VDBE_OP,
2639   SQLITE_MAX_FUNCTION_ARG,
2640   SQLITE_MAX_ATTACHED,
2641   SQLITE_MAX_LIKE_PATTERN_LENGTH,
2642   SQLITE_MAX_VARIABLE_NUMBER,      /* IMP: R-38091-32352 */
2643   SQLITE_MAX_TRIGGER_DEPTH,
2644   SQLITE_MAX_WORKER_THREADS,
2645 };
2646 
2647 /*
2648 ** Make sure the hard limits are set to reasonable values
2649 */
2650 #if SQLITE_MAX_LENGTH<100
2651 # error SQLITE_MAX_LENGTH must be at least 100
2652 #endif
2653 #if SQLITE_MAX_SQL_LENGTH<100
2654 # error SQLITE_MAX_SQL_LENGTH must be at least 100
2655 #endif
2656 #if SQLITE_MAX_SQL_LENGTH>SQLITE_MAX_LENGTH
2657 # error SQLITE_MAX_SQL_LENGTH must not be greater than SQLITE_MAX_LENGTH
2658 #endif
2659 #if SQLITE_MAX_COMPOUND_SELECT<2
2660 # error SQLITE_MAX_COMPOUND_SELECT must be at least 2
2661 #endif
2662 #if SQLITE_MAX_VDBE_OP<40
2663 # error SQLITE_MAX_VDBE_OP must be at least 40
2664 #endif
2665 #if SQLITE_MAX_FUNCTION_ARG<0 || SQLITE_MAX_FUNCTION_ARG>127
2666 # error SQLITE_MAX_FUNCTION_ARG must be between 0 and 127
2667 #endif
2668 #if SQLITE_MAX_ATTACHED<0 || SQLITE_MAX_ATTACHED>125
2669 # error SQLITE_MAX_ATTACHED must be between 0 and 125
2670 #endif
2671 #if SQLITE_MAX_LIKE_PATTERN_LENGTH<1
2672 # error SQLITE_MAX_LIKE_PATTERN_LENGTH must be at least 1
2673 #endif
2674 #if SQLITE_MAX_COLUMN>32767
2675 # error SQLITE_MAX_COLUMN must not exceed 32767
2676 #endif
2677 #if SQLITE_MAX_TRIGGER_DEPTH<1
2678 # error SQLITE_MAX_TRIGGER_DEPTH must be at least 1
2679 #endif
2680 #if SQLITE_MAX_WORKER_THREADS<0 || SQLITE_MAX_WORKER_THREADS>50
2681 # error SQLITE_MAX_WORKER_THREADS must be between 0 and 50
2682 #endif
2683 
2684 
2685 /*
2686 ** Change the value of a limit.  Report the old value.
2687 ** If an invalid limit index is supplied, report -1.
2688 ** Make no changes but still report the old value if the
2689 ** new limit is negative.
2690 **
2691 ** A new lower limit does not shrink existing constructs.
2692 ** It merely prevents new constructs that exceed the limit
2693 ** from forming.
2694 */
2695 int sqlite3_limit(sqlite3 *db, int limitId, int newLimit){
2696   int oldLimit;
2697 
2698 #ifdef SQLITE_ENABLE_API_ARMOR
2699   if( !sqlite3SafetyCheckOk(db) ){
2700     (void)SQLITE_MISUSE_BKPT;
2701     return -1;
2702   }
2703 #endif
2704 
2705   /* EVIDENCE-OF: R-30189-54097 For each limit category SQLITE_LIMIT_NAME
2706   ** there is a hard upper bound set at compile-time by a C preprocessor
2707   ** macro called SQLITE_MAX_NAME. (The "_LIMIT_" in the name is changed to
2708   ** "_MAX_".)
2709   */
2710   assert( aHardLimit[SQLITE_LIMIT_LENGTH]==SQLITE_MAX_LENGTH );
2711   assert( aHardLimit[SQLITE_LIMIT_SQL_LENGTH]==SQLITE_MAX_SQL_LENGTH );
2712   assert( aHardLimit[SQLITE_LIMIT_COLUMN]==SQLITE_MAX_COLUMN );
2713   assert( aHardLimit[SQLITE_LIMIT_EXPR_DEPTH]==SQLITE_MAX_EXPR_DEPTH );
2714   assert( aHardLimit[SQLITE_LIMIT_COMPOUND_SELECT]==SQLITE_MAX_COMPOUND_SELECT);
2715   assert( aHardLimit[SQLITE_LIMIT_VDBE_OP]==SQLITE_MAX_VDBE_OP );
2716   assert( aHardLimit[SQLITE_LIMIT_FUNCTION_ARG]==SQLITE_MAX_FUNCTION_ARG );
2717   assert( aHardLimit[SQLITE_LIMIT_ATTACHED]==SQLITE_MAX_ATTACHED );
2718   assert( aHardLimit[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]==
2719                                                SQLITE_MAX_LIKE_PATTERN_LENGTH );
2720   assert( aHardLimit[SQLITE_LIMIT_VARIABLE_NUMBER]==SQLITE_MAX_VARIABLE_NUMBER);
2721   assert( aHardLimit[SQLITE_LIMIT_TRIGGER_DEPTH]==SQLITE_MAX_TRIGGER_DEPTH );
2722   assert( aHardLimit[SQLITE_LIMIT_WORKER_THREADS]==SQLITE_MAX_WORKER_THREADS );
2723   assert( SQLITE_LIMIT_WORKER_THREADS==(SQLITE_N_LIMIT-1) );
2724 
2725 
2726   if( limitId<0 || limitId>=SQLITE_N_LIMIT ){
2727     return -1;
2728   }
2729   oldLimit = db->aLimit[limitId];
2730   if( newLimit>=0 ){                   /* IMP: R-52476-28732 */
2731     if( newLimit>aHardLimit[limitId] ){
2732       newLimit = aHardLimit[limitId];  /* IMP: R-51463-25634 */
2733     }
2734     db->aLimit[limitId] = newLimit;
2735   }
2736   return oldLimit;                     /* IMP: R-53341-35419 */
2737 }
2738 
2739 /*
2740 ** This function is used to parse both URIs and non-URI filenames passed by the
2741 ** user to API functions sqlite3_open() or sqlite3_open_v2(), and for database
2742 ** URIs specified as part of ATTACH statements.
2743 **
2744 ** The first argument to this function is the name of the VFS to use (or
2745 ** a NULL to signify the default VFS) if the URI does not contain a "vfs=xxx"
2746 ** query parameter. The second argument contains the URI (or non-URI filename)
2747 ** itself. When this function is called the *pFlags variable should contain
2748 ** the default flags to open the database handle with. The value stored in
2749 ** *pFlags may be updated before returning if the URI filename contains
2750 ** "cache=xxx" or "mode=xxx" query parameters.
2751 **
2752 ** If successful, SQLITE_OK is returned. In this case *ppVfs is set to point to
2753 ** the VFS that should be used to open the database file. *pzFile is set to
2754 ** point to a buffer containing the name of the file to open. It is the
2755 ** responsibility of the caller to eventually call sqlite3_free() to release
2756 ** this buffer.
2757 **
2758 ** If an error occurs, then an SQLite error code is returned and *pzErrMsg
2759 ** may be set to point to a buffer containing an English language error
2760 ** message. It is the responsibility of the caller to eventually release
2761 ** this buffer by calling sqlite3_free().
2762 */
2763 int sqlite3ParseUri(
2764   const char *zDefaultVfs,        /* VFS to use if no "vfs=xxx" query option */
2765   const char *zUri,               /* Nul-terminated URI to parse */
2766   unsigned int *pFlags,           /* IN/OUT: SQLITE_OPEN_XXX flags */
2767   sqlite3_vfs **ppVfs,            /* OUT: VFS to use */
2768   char **pzFile,                  /* OUT: Filename component of URI */
2769   char **pzErrMsg                 /* OUT: Error message (if rc!=SQLITE_OK) */
2770 ){
2771   int rc = SQLITE_OK;
2772   unsigned int flags = *pFlags;
2773   const char *zVfs = zDefaultVfs;
2774   char *zFile;
2775   char c;
2776   int nUri = sqlite3Strlen30(zUri);
2777 
2778   assert( *pzErrMsg==0 );
2779 
2780   if( ((flags & SQLITE_OPEN_URI)             /* IMP: R-48725-32206 */
2781             || sqlite3GlobalConfig.bOpenUri) /* IMP: R-51689-46548 */
2782    && nUri>=5 && memcmp(zUri, "file:", 5)==0 /* IMP: R-57884-37496 */
2783   ){
2784     char *zOpt;
2785     int eState;                   /* Parser state when parsing URI */
2786     int iIn;                      /* Input character index */
2787     int iOut = 0;                 /* Output character index */
2788     u64 nByte = nUri+2;           /* Bytes of space to allocate */
2789 
2790     /* Make sure the SQLITE_OPEN_URI flag is set to indicate to the VFS xOpen
2791     ** method that there may be extra parameters following the file-name.  */
2792     flags |= SQLITE_OPEN_URI;
2793 
2794     for(iIn=0; iIn<nUri; iIn++) nByte += (zUri[iIn]=='&');
2795     zFile = sqlite3_malloc64(nByte);
2796     if( !zFile ) return SQLITE_NOMEM_BKPT;
2797 
2798     iIn = 5;
2799 #ifdef SQLITE_ALLOW_URI_AUTHORITY
2800     if( strncmp(zUri+5, "///", 3)==0 ){
2801       iIn = 7;
2802       /* The following condition causes URIs with five leading / characters
2803       ** like file://///host/path to be converted into UNCs like //host/path.
2804       ** The correct URI for that UNC has only two or four leading / characters
2805       ** file://host/path or file:////host/path.  But 5 leading slashes is a
2806       ** common error, we are told, so we handle it as a special case. */
2807       if( strncmp(zUri+7, "///", 3)==0 ){ iIn++; }
2808     }else if( strncmp(zUri+5, "//localhost/", 12)==0 ){
2809       iIn = 16;
2810     }
2811 #else
2812     /* Discard the scheme and authority segments of the URI. */
2813     if( zUri[5]=='/' && zUri[6]=='/' ){
2814       iIn = 7;
2815       while( zUri[iIn] && zUri[iIn]!='/' ) iIn++;
2816       if( iIn!=7 && (iIn!=16 || memcmp("localhost", &zUri[7], 9)) ){
2817         *pzErrMsg = sqlite3_mprintf("invalid uri authority: %.*s",
2818             iIn-7, &zUri[7]);
2819         rc = SQLITE_ERROR;
2820         goto parse_uri_out;
2821       }
2822     }
2823 #endif
2824 
2825     /* Copy the filename and any query parameters into the zFile buffer.
2826     ** Decode %HH escape codes along the way.
2827     **
2828     ** Within this loop, variable eState may be set to 0, 1 or 2, depending
2829     ** on the parsing context. As follows:
2830     **
2831     **   0: Parsing file-name.
2832     **   1: Parsing name section of a name=value query parameter.
2833     **   2: Parsing value section of a name=value query parameter.
2834     */
2835     eState = 0;
2836     while( (c = zUri[iIn])!=0 && c!='#' ){
2837       iIn++;
2838       if( c=='%'
2839        && sqlite3Isxdigit(zUri[iIn])
2840        && sqlite3Isxdigit(zUri[iIn+1])
2841       ){
2842         int octet = (sqlite3HexToInt(zUri[iIn++]) << 4);
2843         octet += sqlite3HexToInt(zUri[iIn++]);
2844 
2845         assert( octet>=0 && octet<256 );
2846         if( octet==0 ){
2847 #ifndef SQLITE_ENABLE_URI_00_ERROR
2848           /* This branch is taken when "%00" appears within the URI. In this
2849           ** case we ignore all text in the remainder of the path, name or
2850           ** value currently being parsed. So ignore the current character
2851           ** and skip to the next "?", "=" or "&", as appropriate. */
2852           while( (c = zUri[iIn])!=0 && c!='#'
2853               && (eState!=0 || c!='?')
2854               && (eState!=1 || (c!='=' && c!='&'))
2855               && (eState!=2 || c!='&')
2856           ){
2857             iIn++;
2858           }
2859           continue;
2860 #else
2861           /* If ENABLE_URI_00_ERROR is defined, "%00" in a URI is an error. */
2862           *pzErrMsg = sqlite3_mprintf("unexpected %%00 in uri");
2863           rc = SQLITE_ERROR;
2864           goto parse_uri_out;
2865 #endif
2866         }
2867         c = octet;
2868       }else if( eState==1 && (c=='&' || c=='=') ){
2869         if( zFile[iOut-1]==0 ){
2870           /* An empty option name. Ignore this option altogether. */
2871           while( zUri[iIn] && zUri[iIn]!='#' && zUri[iIn-1]!='&' ) iIn++;
2872           continue;
2873         }
2874         if( c=='&' ){
2875           zFile[iOut++] = '\0';
2876         }else{
2877           eState = 2;
2878         }
2879         c = 0;
2880       }else if( (eState==0 && c=='?') || (eState==2 && c=='&') ){
2881         c = 0;
2882         eState = 1;
2883       }
2884       zFile[iOut++] = c;
2885     }
2886     if( eState==1 ) zFile[iOut++] = '\0';
2887     zFile[iOut++] = '\0';
2888     zFile[iOut++] = '\0';
2889 
2890     /* Check if there were any options specified that should be interpreted
2891     ** here. Options that are interpreted here include "vfs" and those that
2892     ** correspond to flags that may be passed to the sqlite3_open_v2()
2893     ** method. */
2894     zOpt = &zFile[sqlite3Strlen30(zFile)+1];
2895     while( zOpt[0] ){
2896       int nOpt = sqlite3Strlen30(zOpt);
2897       char *zVal = &zOpt[nOpt+1];
2898       int nVal = sqlite3Strlen30(zVal);
2899 
2900       if( nOpt==3 && memcmp("vfs", zOpt, 3)==0 ){
2901         zVfs = zVal;
2902       }else{
2903         struct OpenMode {
2904           const char *z;
2905           int mode;
2906         } *aMode = 0;
2907         char *zModeType = 0;
2908         int mask = 0;
2909         int limit = 0;
2910 
2911         if( nOpt==5 && memcmp("cache", zOpt, 5)==0 ){
2912           static struct OpenMode aCacheMode[] = {
2913             { "shared",  SQLITE_OPEN_SHAREDCACHE },
2914             { "private", SQLITE_OPEN_PRIVATECACHE },
2915             { 0, 0 }
2916           };
2917 
2918           mask = SQLITE_OPEN_SHAREDCACHE|SQLITE_OPEN_PRIVATECACHE;
2919           aMode = aCacheMode;
2920           limit = mask;
2921           zModeType = "cache";
2922         }
2923         if( nOpt==4 && memcmp("mode", zOpt, 4)==0 ){
2924           static struct OpenMode aOpenMode[] = {
2925             { "ro",  SQLITE_OPEN_READONLY },
2926             { "rw",  SQLITE_OPEN_READWRITE },
2927             { "rwc", SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE },
2928             { "memory", SQLITE_OPEN_MEMORY },
2929             { 0, 0 }
2930           };
2931 
2932           mask = SQLITE_OPEN_READONLY | SQLITE_OPEN_READWRITE
2933                    | SQLITE_OPEN_CREATE | SQLITE_OPEN_MEMORY;
2934           aMode = aOpenMode;
2935           limit = mask & flags;
2936           zModeType = "access";
2937         }
2938 
2939         if( aMode ){
2940           int i;
2941           int mode = 0;
2942           for(i=0; aMode[i].z; i++){
2943             const char *z = aMode[i].z;
2944             if( nVal==sqlite3Strlen30(z) && 0==memcmp(zVal, z, nVal) ){
2945               mode = aMode[i].mode;
2946               break;
2947             }
2948           }
2949           if( mode==0 ){
2950             *pzErrMsg = sqlite3_mprintf("no such %s mode: %s", zModeType, zVal);
2951             rc = SQLITE_ERROR;
2952             goto parse_uri_out;
2953           }
2954           if( (mode & ~SQLITE_OPEN_MEMORY)>limit ){
2955             *pzErrMsg = sqlite3_mprintf("%s mode not allowed: %s",
2956                                         zModeType, zVal);
2957             rc = SQLITE_PERM;
2958             goto parse_uri_out;
2959           }
2960           flags = (flags & ~mask) | mode;
2961         }
2962       }
2963 
2964       zOpt = &zVal[nVal+1];
2965     }
2966 
2967   }else{
2968     zFile = sqlite3_malloc64(nUri+2);
2969     if( !zFile ) return SQLITE_NOMEM_BKPT;
2970     if( nUri ){
2971       memcpy(zFile, zUri, nUri);
2972     }
2973     zFile[nUri] = '\0';
2974     zFile[nUri+1] = '\0';
2975     flags &= ~SQLITE_OPEN_URI;
2976   }
2977 
2978   *ppVfs = sqlite3_vfs_find(zVfs);
2979   if( *ppVfs==0 ){
2980     *pzErrMsg = sqlite3_mprintf("no such vfs: %s", zVfs);
2981     rc = SQLITE_ERROR;
2982   }
2983  parse_uri_out:
2984   if( rc!=SQLITE_OK ){
2985     sqlite3_free(zFile);
2986     zFile = 0;
2987   }
2988   *pFlags = flags;
2989   *pzFile = zFile;
2990   return rc;
2991 }
2992 
2993 #if defined(SQLITE_HAS_CODEC)
2994 /*
2995 ** Process URI filename query parameters relevant to the SQLite Encryption
2996 ** Extension.  Return true if any of the relevant query parameters are
2997 ** seen and return false if not.
2998 */
2999 int sqlite3CodecQueryParameters(
3000   sqlite3 *db,           /* Database connection */
3001   const char *zDb,       /* Which schema is being created/attached */
3002   const char *zUri       /* URI filename */
3003 ){
3004   const char *zKey;
3005   if( (zKey = sqlite3_uri_parameter(zUri, "hexkey"))!=0 && zKey[0] ){
3006     u8 iByte;
3007     int i;
3008     char zDecoded[40];
3009     for(i=0, iByte=0; i<sizeof(zDecoded)*2 && sqlite3Isxdigit(zKey[i]); i++){
3010       iByte = (iByte<<4) + sqlite3HexToInt(zKey[i]);
3011       if( (i&1)!=0 ) zDecoded[i/2] = iByte;
3012     }
3013     sqlite3_key_v2(db, zDb, zDecoded, i/2);
3014     return 1;
3015   }else if( (zKey = sqlite3_uri_parameter(zUri, "key"))!=0 ){
3016     sqlite3_key_v2(db, zDb, zKey, sqlite3Strlen30(zKey));
3017     return 1;
3018   }else if( (zKey = sqlite3_uri_parameter(zUri, "textkey"))!=0 ){
3019     sqlite3_key_v2(db, zDb, zKey, -1);
3020     return 1;
3021   }else{
3022     return 0;
3023   }
3024 }
3025 #endif
3026 
3027 
3028 /*
3029 ** This routine does the work of opening a database on behalf of
3030 ** sqlite3_open() and sqlite3_open16(). The database filename "zFilename"
3031 ** is UTF-8 encoded.
3032 */
3033 static int openDatabase(
3034   const char *zFilename, /* Database filename UTF-8 encoded */
3035   sqlite3 **ppDb,        /* OUT: Returned database handle */
3036   unsigned int flags,    /* Operational flags */
3037   const char *zVfs       /* Name of the VFS to use */
3038 ){
3039   sqlite3 *db;                    /* Store allocated handle here */
3040   int rc;                         /* Return code */
3041   int isThreadsafe;               /* True for threadsafe connections */
3042   char *zOpen = 0;                /* Filename argument to pass to BtreeOpen() */
3043   char *zErrMsg = 0;              /* Error message from sqlite3ParseUri() */
3044 
3045 #ifdef SQLITE_ENABLE_API_ARMOR
3046   if( ppDb==0 ) return SQLITE_MISUSE_BKPT;
3047 #endif
3048   *ppDb = 0;
3049 #ifndef SQLITE_OMIT_AUTOINIT
3050   rc = sqlite3_initialize();
3051   if( rc ) return rc;
3052 #endif
3053 
3054   if( sqlite3GlobalConfig.bCoreMutex==0 ){
3055     isThreadsafe = 0;
3056   }else if( flags & SQLITE_OPEN_NOMUTEX ){
3057     isThreadsafe = 0;
3058   }else if( flags & SQLITE_OPEN_FULLMUTEX ){
3059     isThreadsafe = 1;
3060   }else{
3061     isThreadsafe = sqlite3GlobalConfig.bFullMutex;
3062   }
3063 
3064   if( flags & SQLITE_OPEN_PRIVATECACHE ){
3065     flags &= ~SQLITE_OPEN_SHAREDCACHE;
3066   }else if( sqlite3GlobalConfig.sharedCacheEnabled ){
3067     flags |= SQLITE_OPEN_SHAREDCACHE;
3068   }
3069 
3070   /* Remove harmful bits from the flags parameter
3071   **
3072   ** The SQLITE_OPEN_NOMUTEX and SQLITE_OPEN_FULLMUTEX flags were
3073   ** dealt with in the previous code block.  Besides these, the only
3074   ** valid input flags for sqlite3_open_v2() are SQLITE_OPEN_READONLY,
3075   ** SQLITE_OPEN_READWRITE, SQLITE_OPEN_CREATE, SQLITE_OPEN_SHAREDCACHE,
3076   ** SQLITE_OPEN_PRIVATECACHE, and some reserved bits.  Silently mask
3077   ** off all other flags.
3078   */
3079   flags &=  ~( SQLITE_OPEN_DELETEONCLOSE |
3080                SQLITE_OPEN_EXCLUSIVE |
3081                SQLITE_OPEN_MAIN_DB |
3082                SQLITE_OPEN_TEMP_DB |
3083                SQLITE_OPEN_TRANSIENT_DB |
3084                SQLITE_OPEN_MAIN_JOURNAL |
3085                SQLITE_OPEN_TEMP_JOURNAL |
3086                SQLITE_OPEN_SUBJOURNAL |
3087                SQLITE_OPEN_MASTER_JOURNAL |
3088                SQLITE_OPEN_NOMUTEX |
3089                SQLITE_OPEN_FULLMUTEX |
3090                SQLITE_OPEN_WAL
3091              );
3092 
3093   /* Allocate the sqlite data structure */
3094   db = sqlite3MallocZero( sizeof(sqlite3) );
3095   if( db==0 ) goto opendb_out;
3096   if( isThreadsafe
3097 #ifdef SQLITE_ENABLE_MULTITHREADED_CHECKS
3098    || sqlite3GlobalConfig.bCoreMutex
3099 #endif
3100   ){
3101     db->mutex = sqlite3MutexAlloc(SQLITE_MUTEX_RECURSIVE);
3102     if( db->mutex==0 ){
3103       sqlite3_free(db);
3104       db = 0;
3105       goto opendb_out;
3106     }
3107     if( isThreadsafe==0 ){
3108       sqlite3MutexWarnOnContention(db->mutex);
3109     }
3110   }
3111   sqlite3_mutex_enter(db->mutex);
3112   db->errMask = 0xff;
3113   db->nDb = 2;
3114   db->magic = SQLITE_MAGIC_BUSY;
3115   db->aDb = db->aDbStatic;
3116   db->lookaside.bDisable = 1;
3117   db->lookaside.sz = 0;
3118 
3119   assert( sizeof(db->aLimit)==sizeof(aHardLimit) );
3120   memcpy(db->aLimit, aHardLimit, sizeof(db->aLimit));
3121   db->aLimit[SQLITE_LIMIT_WORKER_THREADS] = SQLITE_DEFAULT_WORKER_THREADS;
3122   db->autoCommit = 1;
3123   db->nextAutovac = -1;
3124   db->szMmap = sqlite3GlobalConfig.szMmap;
3125   db->nextPagesize = 0;
3126   db->nMaxSorterMmap = 0x7FFFFFFF;
3127   db->flags |= SQLITE_ShortColNames
3128                  | SQLITE_EnableTrigger
3129                  | SQLITE_EnableView
3130                  | SQLITE_CacheSpill
3131                  | SQLITE_UnsafeInView
3132                  | SQLITE_VtabInView
3133 
3134 /* The SQLITE_DQS compile-time option determines the default settings
3135 ** for SQLITE_DBCONFIG_DQS_DDL and SQLITE_DBCONFIG_DQS_DML.
3136 **
3137 **    SQLITE_DQS     SQLITE_DBCONFIG_DQS_DDL    SQLITE_DBCONFIG_DQS_DML
3138 **    ----------     -----------------------    -----------------------
3139 **     undefined               on                          on
3140 **         3                   on                          on
3141 **         2                   on                         off
3142 **         1                  off                          on
3143 **         0                  off                         off
3144 **
3145 ** Legacy behavior is 3 (double-quoted string literals are allowed anywhere)
3146 ** and so that is the default.  But developers are encouranged to use
3147 ** -DSQLITE_DQS=0 (best) or -DSQLITE_DQS=1 (second choice) if possible.
3148 */
3149 #if !defined(SQLITE_DQS)
3150 # define SQLITE_DQS 3
3151 #endif
3152 #if (SQLITE_DQS&1)==1
3153                  | SQLITE_DqsDML
3154 #endif
3155 #if (SQLITE_DQS&2)==2
3156                  | SQLITE_DqsDDL
3157 #endif
3158 
3159 #if !defined(SQLITE_DEFAULT_AUTOMATIC_INDEX) || SQLITE_DEFAULT_AUTOMATIC_INDEX
3160                  | SQLITE_AutoIndex
3161 #endif
3162 #if SQLITE_DEFAULT_CKPTFULLFSYNC
3163                  | SQLITE_CkptFullFSync
3164 #endif
3165 #if SQLITE_DEFAULT_FILE_FORMAT<4
3166                  | SQLITE_LegacyFileFmt
3167 #endif
3168 #ifdef SQLITE_ENABLE_LOAD_EXTENSION
3169                  | SQLITE_LoadExtension
3170 #endif
3171 #if SQLITE_DEFAULT_RECURSIVE_TRIGGERS
3172                  | SQLITE_RecTriggers
3173 #endif
3174 #if defined(SQLITE_DEFAULT_FOREIGN_KEYS) && SQLITE_DEFAULT_FOREIGN_KEYS
3175                  | SQLITE_ForeignKeys
3176 #endif
3177 #if defined(SQLITE_REVERSE_UNORDERED_SELECTS)
3178                  | SQLITE_ReverseOrder
3179 #endif
3180 #if defined(SQLITE_ENABLE_OVERSIZE_CELL_CHECK)
3181                  | SQLITE_CellSizeCk
3182 #endif
3183 #if defined(SQLITE_ENABLE_FTS3_TOKENIZER)
3184                  | SQLITE_Fts3Tokenizer
3185 #endif
3186 #if defined(SQLITE_ENABLE_QPSG)
3187                  | SQLITE_EnableQPSG
3188 #endif
3189 #if defined(SQLITE_DEFAULT_DEFENSIVE)
3190                  | SQLITE_Defensive
3191 #endif
3192       ;
3193   sqlite3HashInit(&db->aCollSeq);
3194 #ifndef SQLITE_OMIT_VIRTUALTABLE
3195   sqlite3HashInit(&db->aModule);
3196 #endif
3197 
3198   /* Add the default collation sequence BINARY. BINARY works for both UTF-8
3199   ** and UTF-16, so add a version for each to avoid any unnecessary
3200   ** conversions. The only error that can occur here is a malloc() failure.
3201   **
3202   ** EVIDENCE-OF: R-52786-44878 SQLite defines three built-in collating
3203   ** functions:
3204   */
3205   createCollation(db, sqlite3StrBINARY, SQLITE_UTF8, 0, binCollFunc, 0);
3206   createCollation(db, sqlite3StrBINARY, SQLITE_UTF16BE, 0, binCollFunc, 0);
3207   createCollation(db, sqlite3StrBINARY, SQLITE_UTF16LE, 0, binCollFunc, 0);
3208   createCollation(db, "NOCASE", SQLITE_UTF8, 0, nocaseCollatingFunc, 0);
3209   createCollation(db, "RTRIM", SQLITE_UTF8, 0, rtrimCollFunc, 0);
3210   if( db->mallocFailed ){
3211     goto opendb_out;
3212   }
3213   /* EVIDENCE-OF: R-08308-17224 The default collating function for all
3214   ** strings is BINARY.
3215   */
3216   db->pDfltColl = sqlite3FindCollSeq(db, SQLITE_UTF8, sqlite3StrBINARY, 0);
3217   assert( db->pDfltColl!=0 );
3218 
3219   /* Parse the filename/URI argument
3220   **
3221   ** Only allow sensible combinations of bits in the flags argument.
3222   ** Throw an error if any non-sense combination is used.  If we
3223   ** do not block illegal combinations here, it could trigger
3224   ** assert() statements in deeper layers.  Sensible combinations
3225   ** are:
3226   **
3227   **  1:  SQLITE_OPEN_READONLY
3228   **  2:  SQLITE_OPEN_READWRITE
3229   **  6:  SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE
3230   */
3231   db->openFlags = flags;
3232   assert( SQLITE_OPEN_READONLY  == 0x01 );
3233   assert( SQLITE_OPEN_READWRITE == 0x02 );
3234   assert( SQLITE_OPEN_CREATE    == 0x04 );
3235   testcase( (1<<(flags&7))==0x02 ); /* READONLY */
3236   testcase( (1<<(flags&7))==0x04 ); /* READWRITE */
3237   testcase( (1<<(flags&7))==0x40 ); /* READWRITE | CREATE */
3238   if( ((1<<(flags&7)) & 0x46)==0 ){
3239     rc = SQLITE_MISUSE_BKPT;  /* IMP: R-65497-44594 */
3240   }else{
3241     rc = sqlite3ParseUri(zVfs, zFilename, &flags, &db->pVfs, &zOpen, &zErrMsg);
3242   }
3243   if( rc!=SQLITE_OK ){
3244     if( rc==SQLITE_NOMEM ) sqlite3OomFault(db);
3245     sqlite3ErrorWithMsg(db, rc, zErrMsg ? "%s" : 0, zErrMsg);
3246     sqlite3_free(zErrMsg);
3247     goto opendb_out;
3248   }
3249 
3250   /* Open the backend database driver */
3251   rc = sqlite3BtreeOpen(db->pVfs, zOpen, db, &db->aDb[0].pBt, 0,
3252                         flags | SQLITE_OPEN_MAIN_DB);
3253   if( rc!=SQLITE_OK ){
3254     if( rc==SQLITE_IOERR_NOMEM ){
3255       rc = SQLITE_NOMEM_BKPT;
3256     }
3257     sqlite3Error(db, rc);
3258     goto opendb_out;
3259   }
3260   sqlite3BtreeEnter(db->aDb[0].pBt);
3261   db->aDb[0].pSchema = sqlite3SchemaGet(db, db->aDb[0].pBt);
3262   if( !db->mallocFailed ) ENC(db) = SCHEMA_ENC(db);
3263   sqlite3BtreeLeave(db->aDb[0].pBt);
3264   db->aDb[1].pSchema = sqlite3SchemaGet(db, 0);
3265 
3266   /* The default safety_level for the main database is FULL; for the temp
3267   ** database it is OFF. This matches the pager layer defaults.
3268   */
3269   db->aDb[0].zDbSName = "main";
3270   db->aDb[0].safety_level = SQLITE_DEFAULT_SYNCHRONOUS+1;
3271   db->aDb[1].zDbSName = "temp";
3272   db->aDb[1].safety_level = PAGER_SYNCHRONOUS_OFF;
3273 
3274   db->magic = SQLITE_MAGIC_OPEN;
3275   if( db->mallocFailed ){
3276     goto opendb_out;
3277   }
3278 
3279   /* Register all built-in functions, but do not attempt to read the
3280   ** database schema yet. This is delayed until the first time the database
3281   ** is accessed.
3282   */
3283   sqlite3Error(db, SQLITE_OK);
3284   sqlite3RegisterPerConnectionBuiltinFunctions(db);
3285   rc = sqlite3_errcode(db);
3286 
3287 #ifdef SQLITE_ENABLE_FTS5
3288   /* Register any built-in FTS5 module before loading the automatic
3289   ** extensions. This allows automatic extensions to register FTS5
3290   ** tokenizers and auxiliary functions.  */
3291   if( !db->mallocFailed && rc==SQLITE_OK ){
3292     rc = sqlite3Fts5Init(db);
3293   }
3294 #endif
3295 
3296   /* Load automatic extensions - extensions that have been registered
3297   ** using the sqlite3_automatic_extension() API.
3298   */
3299   if( rc==SQLITE_OK ){
3300     sqlite3AutoLoadExtensions(db);
3301     rc = sqlite3_errcode(db);
3302     if( rc!=SQLITE_OK ){
3303       goto opendb_out;
3304     }
3305   }
3306 
3307 #ifdef SQLITE_ENABLE_FTS1
3308   if( !db->mallocFailed ){
3309     extern int sqlite3Fts1Init(sqlite3*);
3310     rc = sqlite3Fts1Init(db);
3311   }
3312 #endif
3313 
3314 #ifdef SQLITE_ENABLE_FTS2
3315   if( !db->mallocFailed && rc==SQLITE_OK ){
3316     extern int sqlite3Fts2Init(sqlite3*);
3317     rc = sqlite3Fts2Init(db);
3318   }
3319 #endif
3320 
3321 #ifdef SQLITE_ENABLE_FTS3 /* automatically defined by SQLITE_ENABLE_FTS4 */
3322   if( !db->mallocFailed && rc==SQLITE_OK ){
3323     rc = sqlite3Fts3Init(db);
3324   }
3325 #endif
3326 
3327 #if defined(SQLITE_ENABLE_ICU) || defined(SQLITE_ENABLE_ICU_COLLATIONS)
3328   if( !db->mallocFailed && rc==SQLITE_OK ){
3329     rc = sqlite3IcuInit(db);
3330   }
3331 #endif
3332 
3333 #ifdef SQLITE_ENABLE_RTREE
3334   if( !db->mallocFailed && rc==SQLITE_OK){
3335     rc = sqlite3RtreeInit(db);
3336   }
3337 #endif
3338 
3339 #ifdef SQLITE_ENABLE_DBPAGE_VTAB
3340   if( !db->mallocFailed && rc==SQLITE_OK){
3341     rc = sqlite3DbpageRegister(db);
3342   }
3343 #endif
3344 
3345 #ifdef SQLITE_ENABLE_DBSTAT_VTAB
3346   if( !db->mallocFailed && rc==SQLITE_OK){
3347     rc = sqlite3DbstatRegister(db);
3348   }
3349 #endif
3350 
3351 #ifdef SQLITE_ENABLE_JSON1
3352   if( !db->mallocFailed && rc==SQLITE_OK){
3353     rc = sqlite3Json1Init(db);
3354   }
3355 #endif
3356 
3357 #ifdef SQLITE_ENABLE_STMTVTAB
3358   if( !db->mallocFailed && rc==SQLITE_OK){
3359     rc = sqlite3StmtVtabInit(db);
3360   }
3361 #endif
3362 
3363 #ifdef SQLITE_ENABLE_INTERNAL_FUNCTIONS
3364   /* Testing use only!!! The -DSQLITE_ENABLE_INTERNAL_FUNCTIONS=1 compile-time
3365   ** option gives access to internal functions by default.
3366   ** Testing use only!!! */
3367   db->mDbFlags |= DBFLAG_InternalFunc;
3368 #endif
3369 
3370   /* -DSQLITE_DEFAULT_LOCKING_MODE=1 makes EXCLUSIVE the default locking
3371   ** mode.  -DSQLITE_DEFAULT_LOCKING_MODE=0 make NORMAL the default locking
3372   ** mode.  Doing nothing at all also makes NORMAL the default.
3373   */
3374 #ifdef SQLITE_DEFAULT_LOCKING_MODE
3375   db->dfltLockMode = SQLITE_DEFAULT_LOCKING_MODE;
3376   sqlite3PagerLockingMode(sqlite3BtreePager(db->aDb[0].pBt),
3377                           SQLITE_DEFAULT_LOCKING_MODE);
3378 #endif
3379 
3380   if( rc ) sqlite3Error(db, rc);
3381 
3382   /* Enable the lookaside-malloc subsystem */
3383   setupLookaside(db, 0, sqlite3GlobalConfig.szLookaside,
3384                         sqlite3GlobalConfig.nLookaside);
3385 
3386   sqlite3_wal_autocheckpoint(db, SQLITE_DEFAULT_WAL_AUTOCHECKPOINT);
3387 
3388 opendb_out:
3389   if( db ){
3390     assert( db->mutex!=0 || isThreadsafe==0
3391            || sqlite3GlobalConfig.bFullMutex==0 );
3392     sqlite3_mutex_leave(db->mutex);
3393   }
3394   rc = sqlite3_errcode(db);
3395   assert( db!=0 || rc==SQLITE_NOMEM );
3396   if( rc==SQLITE_NOMEM ){
3397     sqlite3_close(db);
3398     db = 0;
3399   }else if( rc!=SQLITE_OK ){
3400     db->magic = SQLITE_MAGIC_SICK;
3401   }
3402   *ppDb = db;
3403 #ifdef SQLITE_ENABLE_SQLLOG
3404   if( sqlite3GlobalConfig.xSqllog ){
3405     /* Opening a db handle. Fourth parameter is passed 0. */
3406     void *pArg = sqlite3GlobalConfig.pSqllogArg;
3407     sqlite3GlobalConfig.xSqllog(pArg, db, zFilename, 0);
3408   }
3409 #endif
3410 #if defined(SQLITE_HAS_CODEC)
3411   if( rc==SQLITE_OK ) sqlite3CodecQueryParameters(db, 0, zOpen);
3412 #endif
3413   sqlite3_free(zOpen);
3414   return rc & 0xff;
3415 }
3416 
3417 
3418 /*
3419 ** Open a new database handle.
3420 */
3421 int sqlite3_open(
3422   const char *zFilename,
3423   sqlite3 **ppDb
3424 ){
3425   return openDatabase(zFilename, ppDb,
3426                       SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
3427 }
3428 int sqlite3_open_v2(
3429   const char *filename,   /* Database filename (UTF-8) */
3430   sqlite3 **ppDb,         /* OUT: SQLite db handle */
3431   int flags,              /* Flags */
3432   const char *zVfs        /* Name of VFS module to use */
3433 ){
3434   return openDatabase(filename, ppDb, (unsigned int)flags, zVfs);
3435 }
3436 
3437 #ifndef SQLITE_OMIT_UTF16
3438 /*
3439 ** Open a new database handle.
3440 */
3441 int sqlite3_open16(
3442   const void *zFilename,
3443   sqlite3 **ppDb
3444 ){
3445   char const *zFilename8;   /* zFilename encoded in UTF-8 instead of UTF-16 */
3446   sqlite3_value *pVal;
3447   int rc;
3448 
3449 #ifdef SQLITE_ENABLE_API_ARMOR
3450   if( ppDb==0 ) return SQLITE_MISUSE_BKPT;
3451 #endif
3452   *ppDb = 0;
3453 #ifndef SQLITE_OMIT_AUTOINIT
3454   rc = sqlite3_initialize();
3455   if( rc ) return rc;
3456 #endif
3457   if( zFilename==0 ) zFilename = "\000\000";
3458   pVal = sqlite3ValueNew(0);
3459   sqlite3ValueSetStr(pVal, -1, zFilename, SQLITE_UTF16NATIVE, SQLITE_STATIC);
3460   zFilename8 = sqlite3ValueText(pVal, SQLITE_UTF8);
3461   if( zFilename8 ){
3462     rc = openDatabase(zFilename8, ppDb,
3463                       SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
3464     assert( *ppDb || rc==SQLITE_NOMEM );
3465     if( rc==SQLITE_OK && !DbHasProperty(*ppDb, 0, DB_SchemaLoaded) ){
3466       SCHEMA_ENC(*ppDb) = ENC(*ppDb) = SQLITE_UTF16NATIVE;
3467     }
3468   }else{
3469     rc = SQLITE_NOMEM_BKPT;
3470   }
3471   sqlite3ValueFree(pVal);
3472 
3473   return rc & 0xff;
3474 }
3475 #endif /* SQLITE_OMIT_UTF16 */
3476 
3477 /*
3478 ** Register a new collation sequence with the database handle db.
3479 */
3480 int sqlite3_create_collation(
3481   sqlite3* db,
3482   const char *zName,
3483   int enc,
3484   void* pCtx,
3485   int(*xCompare)(void*,int,const void*,int,const void*)
3486 ){
3487   return sqlite3_create_collation_v2(db, zName, enc, pCtx, xCompare, 0);
3488 }
3489 
3490 /*
3491 ** Register a new collation sequence with the database handle db.
3492 */
3493 int sqlite3_create_collation_v2(
3494   sqlite3* db,
3495   const char *zName,
3496   int enc,
3497   void* pCtx,
3498   int(*xCompare)(void*,int,const void*,int,const void*),
3499   void(*xDel)(void*)
3500 ){
3501   int rc;
3502 
3503 #ifdef SQLITE_ENABLE_API_ARMOR
3504   if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
3505 #endif
3506   sqlite3_mutex_enter(db->mutex);
3507   assert( !db->mallocFailed );
3508   rc = createCollation(db, zName, (u8)enc, pCtx, xCompare, xDel);
3509   rc = sqlite3ApiExit(db, rc);
3510   sqlite3_mutex_leave(db->mutex);
3511   return rc;
3512 }
3513 
3514 #ifndef SQLITE_OMIT_UTF16
3515 /*
3516 ** Register a new collation sequence with the database handle db.
3517 */
3518 int sqlite3_create_collation16(
3519   sqlite3* db,
3520   const void *zName,
3521   int enc,
3522   void* pCtx,
3523   int(*xCompare)(void*,int,const void*,int,const void*)
3524 ){
3525   int rc = SQLITE_OK;
3526   char *zName8;
3527 
3528 #ifdef SQLITE_ENABLE_API_ARMOR
3529   if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
3530 #endif
3531   sqlite3_mutex_enter(db->mutex);
3532   assert( !db->mallocFailed );
3533   zName8 = sqlite3Utf16to8(db, zName, -1, SQLITE_UTF16NATIVE);
3534   if( zName8 ){
3535     rc = createCollation(db, zName8, (u8)enc, pCtx, xCompare, 0);
3536     sqlite3DbFree(db, zName8);
3537   }
3538   rc = sqlite3ApiExit(db, rc);
3539   sqlite3_mutex_leave(db->mutex);
3540   return rc;
3541 }
3542 #endif /* SQLITE_OMIT_UTF16 */
3543 
3544 /*
3545 ** Register a collation sequence factory callback with the database handle
3546 ** db. Replace any previously installed collation sequence factory.
3547 */
3548 int sqlite3_collation_needed(
3549   sqlite3 *db,
3550   void *pCollNeededArg,
3551   void(*xCollNeeded)(void*,sqlite3*,int eTextRep,const char*)
3552 ){
3553 #ifdef SQLITE_ENABLE_API_ARMOR
3554   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3555 #endif
3556   sqlite3_mutex_enter(db->mutex);
3557   db->xCollNeeded = xCollNeeded;
3558   db->xCollNeeded16 = 0;
3559   db->pCollNeededArg = pCollNeededArg;
3560   sqlite3_mutex_leave(db->mutex);
3561   return SQLITE_OK;
3562 }
3563 
3564 #ifndef SQLITE_OMIT_UTF16
3565 /*
3566 ** Register a collation sequence factory callback with the database handle
3567 ** db. Replace any previously installed collation sequence factory.
3568 */
3569 int sqlite3_collation_needed16(
3570   sqlite3 *db,
3571   void *pCollNeededArg,
3572   void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*)
3573 ){
3574 #ifdef SQLITE_ENABLE_API_ARMOR
3575   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3576 #endif
3577   sqlite3_mutex_enter(db->mutex);
3578   db->xCollNeeded = 0;
3579   db->xCollNeeded16 = xCollNeeded16;
3580   db->pCollNeededArg = pCollNeededArg;
3581   sqlite3_mutex_leave(db->mutex);
3582   return SQLITE_OK;
3583 }
3584 #endif /* SQLITE_OMIT_UTF16 */
3585 
3586 #ifndef SQLITE_OMIT_DEPRECATED
3587 /*
3588 ** This function is now an anachronism. It used to be used to recover from a
3589 ** malloc() failure, but SQLite now does this automatically.
3590 */
3591 int sqlite3_global_recover(void){
3592   return SQLITE_OK;
3593 }
3594 #endif
3595 
3596 /*
3597 ** Test to see whether or not the database connection is in autocommit
3598 ** mode.  Return TRUE if it is and FALSE if not.  Autocommit mode is on
3599 ** by default.  Autocommit is disabled by a BEGIN statement and reenabled
3600 ** by the next COMMIT or ROLLBACK.
3601 */
3602 int sqlite3_get_autocommit(sqlite3 *db){
3603 #ifdef SQLITE_ENABLE_API_ARMOR
3604   if( !sqlite3SafetyCheckOk(db) ){
3605     (void)SQLITE_MISUSE_BKPT;
3606     return 0;
3607   }
3608 #endif
3609   return db->autoCommit;
3610 }
3611 
3612 /*
3613 ** The following routines are substitutes for constants SQLITE_CORRUPT,
3614 ** SQLITE_MISUSE, SQLITE_CANTOPEN, SQLITE_NOMEM and possibly other error
3615 ** constants.  They serve two purposes:
3616 **
3617 **   1.  Serve as a convenient place to set a breakpoint in a debugger
3618 **       to detect when version error conditions occurs.
3619 **
3620 **   2.  Invoke sqlite3_log() to provide the source code location where
3621 **       a low-level error is first detected.
3622 */
3623 int sqlite3ReportError(int iErr, int lineno, const char *zType){
3624   sqlite3_log(iErr, "%s at line %d of [%.10s]",
3625               zType, lineno, 20+sqlite3_sourceid());
3626   return iErr;
3627 }
3628 int sqlite3CorruptError(int lineno){
3629   testcase( sqlite3GlobalConfig.xLog!=0 );
3630   return sqlite3ReportError(SQLITE_CORRUPT, lineno, "database corruption");
3631 }
3632 int sqlite3MisuseError(int lineno){
3633   testcase( sqlite3GlobalConfig.xLog!=0 );
3634   return sqlite3ReportError(SQLITE_MISUSE, lineno, "misuse");
3635 }
3636 int sqlite3CantopenError(int lineno){
3637   testcase( sqlite3GlobalConfig.xLog!=0 );
3638   return sqlite3ReportError(SQLITE_CANTOPEN, lineno, "cannot open file");
3639 }
3640 #ifdef SQLITE_DEBUG
3641 int sqlite3CorruptPgnoError(int lineno, Pgno pgno){
3642   char zMsg[100];
3643   sqlite3_snprintf(sizeof(zMsg), zMsg, "database corruption page %d", pgno);
3644   testcase( sqlite3GlobalConfig.xLog!=0 );
3645   return sqlite3ReportError(SQLITE_CORRUPT, lineno, zMsg);
3646 }
3647 int sqlite3NomemError(int lineno){
3648   testcase( sqlite3GlobalConfig.xLog!=0 );
3649   return sqlite3ReportError(SQLITE_NOMEM, lineno, "OOM");
3650 }
3651 int sqlite3IoerrnomemError(int lineno){
3652   testcase( sqlite3GlobalConfig.xLog!=0 );
3653   return sqlite3ReportError(SQLITE_IOERR_NOMEM, lineno, "I/O OOM error");
3654 }
3655 #endif
3656 
3657 #ifndef SQLITE_OMIT_DEPRECATED
3658 /*
3659 ** This is a convenience routine that makes sure that all thread-specific
3660 ** data for this thread has been deallocated.
3661 **
3662 ** SQLite no longer uses thread-specific data so this routine is now a
3663 ** no-op.  It is retained for historical compatibility.
3664 */
3665 void sqlite3_thread_cleanup(void){
3666 }
3667 #endif
3668 
3669 /*
3670 ** Return meta information about a specific column of a database table.
3671 ** See comment in sqlite3.h (sqlite.h.in) for details.
3672 */
3673 int sqlite3_table_column_metadata(
3674   sqlite3 *db,                /* Connection handle */
3675   const char *zDbName,        /* Database name or NULL */
3676   const char *zTableName,     /* Table name */
3677   const char *zColumnName,    /* Column name */
3678   char const **pzDataType,    /* OUTPUT: Declared data type */
3679   char const **pzCollSeq,     /* OUTPUT: Collation sequence name */
3680   int *pNotNull,              /* OUTPUT: True if NOT NULL constraint exists */
3681   int *pPrimaryKey,           /* OUTPUT: True if column part of PK */
3682   int *pAutoinc               /* OUTPUT: True if column is auto-increment */
3683 ){
3684   int rc;
3685   char *zErrMsg = 0;
3686   Table *pTab = 0;
3687   Column *pCol = 0;
3688   int iCol = 0;
3689   char const *zDataType = 0;
3690   char const *zCollSeq = 0;
3691   int notnull = 0;
3692   int primarykey = 0;
3693   int autoinc = 0;
3694 
3695 
3696 #ifdef SQLITE_ENABLE_API_ARMOR
3697   if( !sqlite3SafetyCheckOk(db) || zTableName==0 ){
3698     return SQLITE_MISUSE_BKPT;
3699   }
3700 #endif
3701 
3702   /* Ensure the database schema has been loaded */
3703   sqlite3_mutex_enter(db->mutex);
3704   sqlite3BtreeEnterAll(db);
3705   rc = sqlite3Init(db, &zErrMsg);
3706   if( SQLITE_OK!=rc ){
3707     goto error_out;
3708   }
3709 
3710   /* Locate the table in question */
3711   pTab = sqlite3FindTable(db, zTableName, zDbName);
3712   if( !pTab || pTab->pSelect ){
3713     pTab = 0;
3714     goto error_out;
3715   }
3716 
3717   /* Find the column for which info is requested */
3718   if( zColumnName==0 ){
3719     /* Query for existance of table only */
3720   }else{
3721     for(iCol=0; iCol<pTab->nCol; iCol++){
3722       pCol = &pTab->aCol[iCol];
3723       if( 0==sqlite3StrICmp(pCol->zName, zColumnName) ){
3724         break;
3725       }
3726     }
3727     if( iCol==pTab->nCol ){
3728       if( HasRowid(pTab) && sqlite3IsRowid(zColumnName) ){
3729         iCol = pTab->iPKey;
3730         pCol = iCol>=0 ? &pTab->aCol[iCol] : 0;
3731       }else{
3732         pTab = 0;
3733         goto error_out;
3734       }
3735     }
3736   }
3737 
3738   /* The following block stores the meta information that will be returned
3739   ** to the caller in local variables zDataType, zCollSeq, notnull, primarykey
3740   ** and autoinc. At this point there are two possibilities:
3741   **
3742   **     1. The specified column name was rowid", "oid" or "_rowid_"
3743   **        and there is no explicitly declared IPK column.
3744   **
3745   **     2. The table is not a view and the column name identified an
3746   **        explicitly declared column. Copy meta information from *pCol.
3747   */
3748   if( pCol ){
3749     zDataType = sqlite3ColumnType(pCol,0);
3750     zCollSeq = pCol->zColl;
3751     notnull = pCol->notNull!=0;
3752     primarykey  = (pCol->colFlags & COLFLAG_PRIMKEY)!=0;
3753     autoinc = pTab->iPKey==iCol && (pTab->tabFlags & TF_Autoincrement)!=0;
3754   }else{
3755     zDataType = "INTEGER";
3756     primarykey = 1;
3757   }
3758   if( !zCollSeq ){
3759     zCollSeq = sqlite3StrBINARY;
3760   }
3761 
3762 error_out:
3763   sqlite3BtreeLeaveAll(db);
3764 
3765   /* Whether the function call succeeded or failed, set the output parameters
3766   ** to whatever their local counterparts contain. If an error did occur,
3767   ** this has the effect of zeroing all output parameters.
3768   */
3769   if( pzDataType ) *pzDataType = zDataType;
3770   if( pzCollSeq ) *pzCollSeq = zCollSeq;
3771   if( pNotNull ) *pNotNull = notnull;
3772   if( pPrimaryKey ) *pPrimaryKey = primarykey;
3773   if( pAutoinc ) *pAutoinc = autoinc;
3774 
3775   if( SQLITE_OK==rc && !pTab ){
3776     sqlite3DbFree(db, zErrMsg);
3777     zErrMsg = sqlite3MPrintf(db, "no such table column: %s.%s", zTableName,
3778         zColumnName);
3779     rc = SQLITE_ERROR;
3780   }
3781   sqlite3ErrorWithMsg(db, rc, (zErrMsg?"%s":0), zErrMsg);
3782   sqlite3DbFree(db, zErrMsg);
3783   rc = sqlite3ApiExit(db, rc);
3784   sqlite3_mutex_leave(db->mutex);
3785   return rc;
3786 }
3787 
3788 /*
3789 ** Sleep for a little while.  Return the amount of time slept.
3790 */
3791 int sqlite3_sleep(int ms){
3792   sqlite3_vfs *pVfs;
3793   int rc;
3794   pVfs = sqlite3_vfs_find(0);
3795   if( pVfs==0 ) return 0;
3796 
3797   /* This function works in milliseconds, but the underlying OsSleep()
3798   ** API uses microseconds. Hence the 1000's.
3799   */
3800   rc = (sqlite3OsSleep(pVfs, 1000*ms)/1000);
3801   return rc;
3802 }
3803 
3804 /*
3805 ** Enable or disable the extended result codes.
3806 */
3807 int sqlite3_extended_result_codes(sqlite3 *db, int onoff){
3808 #ifdef SQLITE_ENABLE_API_ARMOR
3809   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3810 #endif
3811   sqlite3_mutex_enter(db->mutex);
3812   db->errMask = onoff ? 0xffffffff : 0xff;
3813   sqlite3_mutex_leave(db->mutex);
3814   return SQLITE_OK;
3815 }
3816 
3817 /*
3818 ** Invoke the xFileControl method on a particular database.
3819 */
3820 int sqlite3_file_control(sqlite3 *db, const char *zDbName, int op, void *pArg){
3821   int rc = SQLITE_ERROR;
3822   Btree *pBtree;
3823 
3824 #ifdef SQLITE_ENABLE_API_ARMOR
3825   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3826 #endif
3827   sqlite3_mutex_enter(db->mutex);
3828   pBtree = sqlite3DbNameToBtree(db, zDbName);
3829   if( pBtree ){
3830     Pager *pPager;
3831     sqlite3_file *fd;
3832     sqlite3BtreeEnter(pBtree);
3833     pPager = sqlite3BtreePager(pBtree);
3834     assert( pPager!=0 );
3835     fd = sqlite3PagerFile(pPager);
3836     assert( fd!=0 );
3837     if( op==SQLITE_FCNTL_FILE_POINTER ){
3838       *(sqlite3_file**)pArg = fd;
3839       rc = SQLITE_OK;
3840     }else if( op==SQLITE_FCNTL_VFS_POINTER ){
3841       *(sqlite3_vfs**)pArg = sqlite3PagerVfs(pPager);
3842       rc = SQLITE_OK;
3843     }else if( op==SQLITE_FCNTL_JOURNAL_POINTER ){
3844       *(sqlite3_file**)pArg = sqlite3PagerJrnlFile(pPager);
3845       rc = SQLITE_OK;
3846     }else if( op==SQLITE_FCNTL_DATA_VERSION ){
3847       *(unsigned int*)pArg = sqlite3PagerDataVersion(pPager);
3848       rc = SQLITE_OK;
3849     }else{
3850       rc = sqlite3OsFileControl(fd, op, pArg);
3851     }
3852     sqlite3BtreeLeave(pBtree);
3853   }
3854   sqlite3_mutex_leave(db->mutex);
3855   return rc;
3856 }
3857 
3858 /*
3859 ** Interface to the testing logic.
3860 */
3861 int sqlite3_test_control(int op, ...){
3862   int rc = 0;
3863 #ifdef SQLITE_UNTESTABLE
3864   UNUSED_PARAMETER(op);
3865 #else
3866   va_list ap;
3867   va_start(ap, op);
3868   switch( op ){
3869 
3870     /*
3871     ** Save the current state of the PRNG.
3872     */
3873     case SQLITE_TESTCTRL_PRNG_SAVE: {
3874       sqlite3PrngSaveState();
3875       break;
3876     }
3877 
3878     /*
3879     ** Restore the state of the PRNG to the last state saved using
3880     ** PRNG_SAVE.  If PRNG_SAVE has never before been called, then
3881     ** this verb acts like PRNG_RESET.
3882     */
3883     case SQLITE_TESTCTRL_PRNG_RESTORE: {
3884       sqlite3PrngRestoreState();
3885       break;
3886     }
3887 
3888     /*  sqlite3_test_control(SQLITE_TESTCTRL_PRNG_SEED, int x, sqlite3 *db);
3889     **
3890     ** Control the seed for the pseudo-random number generator (PRNG) that
3891     ** is built into SQLite.  Cases:
3892     **
3893     **    x!=0 && db!=0       Seed the PRNG to the current value of the
3894     **                        schema cookie in the main database for db, or
3895     **                        x if the schema cookie is zero.  This case
3896     **                        is convenient to use with database fuzzers
3897     **                        as it allows the fuzzer some control over the
3898     **                        the PRNG seed.
3899     **
3900     **    x!=0 && db==0       Seed the PRNG to the value of x.
3901     **
3902     **    x==0 && db==0       Revert to default behavior of using the
3903     **                        xRandomness method on the primary VFS.
3904     **
3905     ** This test-control also resets the PRNG so that the new seed will
3906     ** be used for the next call to sqlite3_randomness().
3907     */
3908     case SQLITE_TESTCTRL_PRNG_SEED: {
3909       int x = va_arg(ap, int);
3910       int y;
3911       sqlite3 *db = va_arg(ap, sqlite3*);
3912       assert( db==0 || db->aDb[0].pSchema!=0 );
3913       if( db && (y = db->aDb[0].pSchema->schema_cookie)!=0 ){ x = y; }
3914       sqlite3Config.iPrngSeed = x;
3915       sqlite3_randomness(0,0);
3916       break;
3917     }
3918 
3919     /*
3920     **  sqlite3_test_control(BITVEC_TEST, size, program)
3921     **
3922     ** Run a test against a Bitvec object of size.  The program argument
3923     ** is an array of integers that defines the test.  Return -1 on a
3924     ** memory allocation error, 0 on success, or non-zero for an error.
3925     ** See the sqlite3BitvecBuiltinTest() for additional information.
3926     */
3927     case SQLITE_TESTCTRL_BITVEC_TEST: {
3928       int sz = va_arg(ap, int);
3929       int *aProg = va_arg(ap, int*);
3930       rc = sqlite3BitvecBuiltinTest(sz, aProg);
3931       break;
3932     }
3933 
3934     /*
3935     **  sqlite3_test_control(FAULT_INSTALL, xCallback)
3936     **
3937     ** Arrange to invoke xCallback() whenever sqlite3FaultSim() is called,
3938     ** if xCallback is not NULL.
3939     **
3940     ** As a test of the fault simulator mechanism itself, sqlite3FaultSim(0)
3941     ** is called immediately after installing the new callback and the return
3942     ** value from sqlite3FaultSim(0) becomes the return from
3943     ** sqlite3_test_control().
3944     */
3945     case SQLITE_TESTCTRL_FAULT_INSTALL: {
3946       /* MSVC is picky about pulling func ptrs from va lists.
3947       ** http://support.microsoft.com/kb/47961
3948       ** sqlite3GlobalConfig.xTestCallback = va_arg(ap, int(*)(int));
3949       */
3950       typedef int(*TESTCALLBACKFUNC_t)(int);
3951       sqlite3GlobalConfig.xTestCallback = va_arg(ap, TESTCALLBACKFUNC_t);
3952       rc = sqlite3FaultSim(0);
3953       break;
3954     }
3955 
3956     /*
3957     **  sqlite3_test_control(BENIGN_MALLOC_HOOKS, xBegin, xEnd)
3958     **
3959     ** Register hooks to call to indicate which malloc() failures
3960     ** are benign.
3961     */
3962     case SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS: {
3963       typedef void (*void_function)(void);
3964       void_function xBenignBegin;
3965       void_function xBenignEnd;
3966       xBenignBegin = va_arg(ap, void_function);
3967       xBenignEnd = va_arg(ap, void_function);
3968       sqlite3BenignMallocHooks(xBenignBegin, xBenignEnd);
3969       break;
3970     }
3971 
3972     /*
3973     **  sqlite3_test_control(SQLITE_TESTCTRL_PENDING_BYTE, unsigned int X)
3974     **
3975     ** Set the PENDING byte to the value in the argument, if X>0.
3976     ** Make no changes if X==0.  Return the value of the pending byte
3977     ** as it existing before this routine was called.
3978     **
3979     ** IMPORTANT:  Changing the PENDING byte from 0x40000000 results in
3980     ** an incompatible database file format.  Changing the PENDING byte
3981     ** while any database connection is open results in undefined and
3982     ** deleterious behavior.
3983     */
3984     case SQLITE_TESTCTRL_PENDING_BYTE: {
3985       rc = PENDING_BYTE;
3986 #ifndef SQLITE_OMIT_WSD
3987       {
3988         unsigned int newVal = va_arg(ap, unsigned int);
3989         if( newVal ) sqlite3PendingByte = newVal;
3990       }
3991 #endif
3992       break;
3993     }
3994 
3995     /*
3996     **  sqlite3_test_control(SQLITE_TESTCTRL_ASSERT, int X)
3997     **
3998     ** This action provides a run-time test to see whether or not
3999     ** assert() was enabled at compile-time.  If X is true and assert()
4000     ** is enabled, then the return value is true.  If X is true and
4001     ** assert() is disabled, then the return value is zero.  If X is
4002     ** false and assert() is enabled, then the assertion fires and the
4003     ** process aborts.  If X is false and assert() is disabled, then the
4004     ** return value is zero.
4005     */
4006     case SQLITE_TESTCTRL_ASSERT: {
4007       volatile int x = 0;
4008       assert( /*side-effects-ok*/ (x = va_arg(ap,int))!=0 );
4009       rc = x;
4010       break;
4011     }
4012 
4013 
4014     /*
4015     **  sqlite3_test_control(SQLITE_TESTCTRL_ALWAYS, int X)
4016     **
4017     ** This action provides a run-time test to see how the ALWAYS and
4018     ** NEVER macros were defined at compile-time.
4019     **
4020     ** The return value is ALWAYS(X) if X is true, or 0 if X is false.
4021     **
4022     ** The recommended test is X==2.  If the return value is 2, that means
4023     ** ALWAYS() and NEVER() are both no-op pass-through macros, which is the
4024     ** default setting.  If the return value is 1, then ALWAYS() is either
4025     ** hard-coded to true or else it asserts if its argument is false.
4026     ** The first behavior (hard-coded to true) is the case if
4027     ** SQLITE_TESTCTRL_ASSERT shows that assert() is disabled and the second
4028     ** behavior (assert if the argument to ALWAYS() is false) is the case if
4029     ** SQLITE_TESTCTRL_ASSERT shows that assert() is enabled.
4030     **
4031     ** The run-time test procedure might look something like this:
4032     **
4033     **    if( sqlite3_test_control(SQLITE_TESTCTRL_ALWAYS, 2)==2 ){
4034     **      // ALWAYS() and NEVER() are no-op pass-through macros
4035     **    }else if( sqlite3_test_control(SQLITE_TESTCTRL_ASSERT, 1) ){
4036     **      // ALWAYS(x) asserts that x is true. NEVER(x) asserts x is false.
4037     **    }else{
4038     **      // ALWAYS(x) is a constant 1.  NEVER(x) is a constant 0.
4039     **    }
4040     */
4041     case SQLITE_TESTCTRL_ALWAYS: {
4042       int x = va_arg(ap,int);
4043       rc = x ? ALWAYS(x) : 0;
4044       break;
4045     }
4046 
4047     /*
4048     **   sqlite3_test_control(SQLITE_TESTCTRL_BYTEORDER);
4049     **
4050     ** The integer returned reveals the byte-order of the computer on which
4051     ** SQLite is running:
4052     **
4053     **       1     big-endian,    determined at run-time
4054     **      10     little-endian, determined at run-time
4055     **  432101     big-endian,    determined at compile-time
4056     **  123410     little-endian, determined at compile-time
4057     */
4058     case SQLITE_TESTCTRL_BYTEORDER: {
4059       rc = SQLITE_BYTEORDER*100 + SQLITE_LITTLEENDIAN*10 + SQLITE_BIGENDIAN;
4060       break;
4061     }
4062 
4063     /*   sqlite3_test_control(SQLITE_TESTCTRL_RESERVE, sqlite3 *db, int N)
4064     **
4065     ** Set the nReserve size to N for the main database on the database
4066     ** connection db.
4067     */
4068     case SQLITE_TESTCTRL_RESERVE: {
4069       sqlite3 *db = va_arg(ap, sqlite3*);
4070       int x = va_arg(ap,int);
4071       sqlite3_mutex_enter(db->mutex);
4072       sqlite3BtreeSetPageSize(db->aDb[0].pBt, 0, x, 0);
4073       sqlite3_mutex_leave(db->mutex);
4074       break;
4075     }
4076 
4077     /*  sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS, sqlite3 *db, int N)
4078     **
4079     ** Enable or disable various optimizations for testing purposes.  The
4080     ** argument N is a bitmask of optimizations to be disabled.  For normal
4081     ** operation N should be 0.  The idea is that a test program (like the
4082     ** SQL Logic Test or SLT test module) can run the same SQL multiple times
4083     ** with various optimizations disabled to verify that the same answer
4084     ** is obtained in every case.
4085     */
4086     case SQLITE_TESTCTRL_OPTIMIZATIONS: {
4087       sqlite3 *db = va_arg(ap, sqlite3*);
4088       db->dbOptFlags = (u16)(va_arg(ap, int) & 0xffff);
4089       break;
4090     }
4091 
4092     /*   sqlite3_test_control(SQLITE_TESTCTRL_LOCALTIME_FAULT, int onoff);
4093     **
4094     ** If parameter onoff is non-zero, subsequent calls to localtime()
4095     ** and its variants fail. If onoff is zero, undo this setting.
4096     */
4097     case SQLITE_TESTCTRL_LOCALTIME_FAULT: {
4098       sqlite3GlobalConfig.bLocaltimeFault = va_arg(ap, int);
4099       break;
4100     }
4101 
4102     /*   sqlite3_test_control(SQLITE_TESTCTRL_INTERNAL_FUNCTIONS, sqlite3*);
4103     **
4104     ** Toggle the ability to use internal functions on or off for
4105     ** the database connection given in the argument.
4106     */
4107     case SQLITE_TESTCTRL_INTERNAL_FUNCTIONS: {
4108       sqlite3 *db = va_arg(ap, sqlite3*);
4109       db->mDbFlags ^= DBFLAG_InternalFunc;
4110       break;
4111     }
4112 
4113     /*   sqlite3_test_control(SQLITE_TESTCTRL_NEVER_CORRUPT, int);
4114     **
4115     ** Set or clear a flag that indicates that the database file is always well-
4116     ** formed and never corrupt.  This flag is clear by default, indicating that
4117     ** database files might have arbitrary corruption.  Setting the flag during
4118     ** testing causes certain assert() statements in the code to be activated
4119     ** that demonstrat invariants on well-formed database files.
4120     */
4121     case SQLITE_TESTCTRL_NEVER_CORRUPT: {
4122       sqlite3GlobalConfig.neverCorrupt = va_arg(ap, int);
4123       break;
4124     }
4125 
4126     /*   sqlite3_test_control(SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS, int);
4127     **
4128     ** Set or clear a flag that causes SQLite to verify that type, name,
4129     ** and tbl_name fields of the sqlite_master table.  This is normally
4130     ** on, but it is sometimes useful to turn it off for testing.
4131     */
4132     case SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS: {
4133       sqlite3GlobalConfig.bExtraSchemaChecks = va_arg(ap, int);
4134       break;
4135     }
4136 
4137     /* Set the threshold at which OP_Once counters reset back to zero.
4138     ** By default this is 0x7ffffffe (over 2 billion), but that value is
4139     ** too big to test in a reasonable amount of time, so this control is
4140     ** provided to set a small and easily reachable reset value.
4141     */
4142     case SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD: {
4143       sqlite3GlobalConfig.iOnceResetThreshold = va_arg(ap, int);
4144       break;
4145     }
4146 
4147     /*   sqlite3_test_control(SQLITE_TESTCTRL_VDBE_COVERAGE, xCallback, ptr);
4148     **
4149     ** Set the VDBE coverage callback function to xCallback with context
4150     ** pointer ptr.
4151     */
4152     case SQLITE_TESTCTRL_VDBE_COVERAGE: {
4153 #ifdef SQLITE_VDBE_COVERAGE
4154       typedef void (*branch_callback)(void*,unsigned int,
4155                                       unsigned char,unsigned char);
4156       sqlite3GlobalConfig.xVdbeBranch = va_arg(ap,branch_callback);
4157       sqlite3GlobalConfig.pVdbeBranchArg = va_arg(ap,void*);
4158 #endif
4159       break;
4160     }
4161 
4162     /*   sqlite3_test_control(SQLITE_TESTCTRL_SORTER_MMAP, db, nMax); */
4163     case SQLITE_TESTCTRL_SORTER_MMAP: {
4164       sqlite3 *db = va_arg(ap, sqlite3*);
4165       db->nMaxSorterMmap = va_arg(ap, int);
4166       break;
4167     }
4168 
4169     /*   sqlite3_test_control(SQLITE_TESTCTRL_ISINIT);
4170     **
4171     ** Return SQLITE_OK if SQLite has been initialized and SQLITE_ERROR if
4172     ** not.
4173     */
4174     case SQLITE_TESTCTRL_ISINIT: {
4175       if( sqlite3GlobalConfig.isInit==0 ) rc = SQLITE_ERROR;
4176       break;
4177     }
4178 
4179     /*  sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, db, dbName, onOff, tnum);
4180     **
4181     ** This test control is used to create imposter tables.  "db" is a pointer
4182     ** to the database connection.  dbName is the database name (ex: "main" or
4183     ** "temp") which will receive the imposter.  "onOff" turns imposter mode on
4184     ** or off.  "tnum" is the root page of the b-tree to which the imposter
4185     ** table should connect.
4186     **
4187     ** Enable imposter mode only when the schema has already been parsed.  Then
4188     ** run a single CREATE TABLE statement to construct the imposter table in
4189     ** the parsed schema.  Then turn imposter mode back off again.
4190     **
4191     ** If onOff==0 and tnum>0 then reset the schema for all databases, causing
4192     ** the schema to be reparsed the next time it is needed.  This has the
4193     ** effect of erasing all imposter tables.
4194     */
4195     case SQLITE_TESTCTRL_IMPOSTER: {
4196       sqlite3 *db = va_arg(ap, sqlite3*);
4197       sqlite3_mutex_enter(db->mutex);
4198       db->init.iDb = sqlite3FindDbName(db, va_arg(ap,const char*));
4199       db->init.busy = db->init.imposterTable = va_arg(ap,int);
4200       db->init.newTnum = va_arg(ap,int);
4201       if( db->init.busy==0 && db->init.newTnum>0 ){
4202         sqlite3ResetAllSchemasOfConnection(db);
4203       }
4204       sqlite3_mutex_leave(db->mutex);
4205       break;
4206     }
4207 
4208 #if defined(YYCOVERAGE)
4209     /*  sqlite3_test_control(SQLITE_TESTCTRL_PARSER_COVERAGE, FILE *out)
4210     **
4211     ** This test control (only available when SQLite is compiled with
4212     ** -DYYCOVERAGE) writes a report onto "out" that shows all
4213     ** state/lookahead combinations in the parser state machine
4214     ** which are never exercised.  If any state is missed, make the
4215     ** return code SQLITE_ERROR.
4216     */
4217     case SQLITE_TESTCTRL_PARSER_COVERAGE: {
4218       FILE *out = va_arg(ap, FILE*);
4219       if( sqlite3ParserCoverage(out) ) rc = SQLITE_ERROR;
4220       break;
4221     }
4222 #endif /* defined(YYCOVERAGE) */
4223 
4224     /*  sqlite3_test_control(SQLITE_TESTCTRL_RESULT_INTREAL, sqlite3_context*);
4225     **
4226     ** This test-control causes the most recent sqlite3_result_int64() value
4227     ** to be interpreted as a MEM_IntReal instead of as an MEM_Int.  Normally,
4228     ** MEM_IntReal values only arise during an INSERT operation of integer
4229     ** values into a REAL column, so they can be challenging to test.  This
4230     ** test-control enables us to write an intreal() SQL function that can
4231     ** inject an intreal() value at arbitrary places in an SQL statement,
4232     ** for testing purposes.
4233     */
4234     case SQLITE_TESTCTRL_RESULT_INTREAL: {
4235       sqlite3_context *pCtx = va_arg(ap, sqlite3_context*);
4236       sqlite3ResultIntReal(pCtx);
4237       break;
4238     }
4239   }
4240   va_end(ap);
4241 #endif /* SQLITE_UNTESTABLE */
4242   return rc;
4243 }
4244 
4245 #ifdef SQLITE_DEBUG
4246 /*
4247 ** This routine appears inside assert() statements only.
4248 **
4249 ** Return the number of URI parameters that follow the filename.
4250 */
4251 int sqlite3UriCount(const char *z){
4252   int n = 0;
4253   if( z==0 ) return 0;
4254   z += strlen(z)+1;
4255   while( z[0] ){
4256     z += strlen(z)+1;
4257     z += strlen(z)+1;
4258     n++;
4259   }
4260   return n;
4261 }
4262 #endif /* SQLITE_DEBUG */
4263 
4264 /*
4265 ** This is a utility routine, useful to VFS implementations, that checks
4266 ** to see if a database file was a URI that contained a specific query
4267 ** parameter, and if so obtains the value of the query parameter.
4268 **
4269 ** The zFilename argument is the filename pointer passed into the xOpen()
4270 ** method of a VFS implementation.  The zParam argument is the name of the
4271 ** query parameter we seek.  This routine returns the value of the zParam
4272 ** parameter if it exists.  If the parameter does not exist, this routine
4273 ** returns a NULL pointer.
4274 */
4275 const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam){
4276   if( zFilename==0 || zParam==0 ) return 0;
4277   zFilename += sqlite3Strlen30(zFilename) + 1;
4278   while( zFilename[0] ){
4279     int x = strcmp(zFilename, zParam);
4280     zFilename += sqlite3Strlen30(zFilename) + 1;
4281     if( x==0 ) return zFilename;
4282     zFilename += sqlite3Strlen30(zFilename) + 1;
4283   }
4284   return 0;
4285 }
4286 
4287 /*
4288 ** Return a boolean value for a query parameter.
4289 */
4290 int sqlite3_uri_boolean(const char *zFilename, const char *zParam, int bDflt){
4291   const char *z = sqlite3_uri_parameter(zFilename, zParam);
4292   bDflt = bDflt!=0;
4293   return z ? sqlite3GetBoolean(z, bDflt) : bDflt;
4294 }
4295 
4296 /*
4297 ** Return a 64-bit integer value for a query parameter.
4298 */
4299 sqlite3_int64 sqlite3_uri_int64(
4300   const char *zFilename,    /* Filename as passed to xOpen */
4301   const char *zParam,       /* URI parameter sought */
4302   sqlite3_int64 bDflt       /* return if parameter is missing */
4303 ){
4304   const char *z = sqlite3_uri_parameter(zFilename, zParam);
4305   sqlite3_int64 v;
4306   if( z && sqlite3DecOrHexToI64(z, &v)==0 ){
4307     bDflt = v;
4308   }
4309   return bDflt;
4310 }
4311 
4312 /*
4313 ** Return the Btree pointer identified by zDbName.  Return NULL if not found.
4314 */
4315 Btree *sqlite3DbNameToBtree(sqlite3 *db, const char *zDbName){
4316   int iDb = zDbName ? sqlite3FindDbName(db, zDbName) : 0;
4317   return iDb<0 ? 0 : db->aDb[iDb].pBt;
4318 }
4319 
4320 /*
4321 ** Return the filename of the database associated with a database
4322 ** connection.
4323 */
4324 const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName){
4325   Btree *pBt;
4326 #ifdef SQLITE_ENABLE_API_ARMOR
4327   if( !sqlite3SafetyCheckOk(db) ){
4328     (void)SQLITE_MISUSE_BKPT;
4329     return 0;
4330   }
4331 #endif
4332   pBt = sqlite3DbNameToBtree(db, zDbName);
4333   return pBt ? sqlite3BtreeGetFilename(pBt) : 0;
4334 }
4335 
4336 /*
4337 ** Return 1 if database is read-only or 0 if read/write.  Return -1 if
4338 ** no such database exists.
4339 */
4340 int sqlite3_db_readonly(sqlite3 *db, const char *zDbName){
4341   Btree *pBt;
4342 #ifdef SQLITE_ENABLE_API_ARMOR
4343   if( !sqlite3SafetyCheckOk(db) ){
4344     (void)SQLITE_MISUSE_BKPT;
4345     return -1;
4346   }
4347 #endif
4348   pBt = sqlite3DbNameToBtree(db, zDbName);
4349   return pBt ? sqlite3BtreeIsReadonly(pBt) : -1;
4350 }
4351 
4352 #ifdef SQLITE_ENABLE_SNAPSHOT
4353 /*
4354 ** Obtain a snapshot handle for the snapshot of database zDb currently
4355 ** being read by handle db.
4356 */
4357 int sqlite3_snapshot_get(
4358   sqlite3 *db,
4359   const char *zDb,
4360   sqlite3_snapshot **ppSnapshot
4361 ){
4362   int rc = SQLITE_ERROR;
4363 #ifndef SQLITE_OMIT_WAL
4364 
4365 #ifdef SQLITE_ENABLE_API_ARMOR
4366   if( !sqlite3SafetyCheckOk(db) ){
4367     return SQLITE_MISUSE_BKPT;
4368   }
4369 #endif
4370   sqlite3_mutex_enter(db->mutex);
4371 
4372   if( db->autoCommit==0 ){
4373     int iDb = sqlite3FindDbName(db, zDb);
4374     if( iDb==0 || iDb>1 ){
4375       Btree *pBt = db->aDb[iDb].pBt;
4376       if( 0==sqlite3BtreeIsInTrans(pBt) ){
4377         rc = sqlite3BtreeBeginTrans(pBt, 0, 0);
4378         if( rc==SQLITE_OK ){
4379           rc = sqlite3PagerSnapshotGet(sqlite3BtreePager(pBt), ppSnapshot);
4380         }
4381       }
4382     }
4383   }
4384 
4385   sqlite3_mutex_leave(db->mutex);
4386 #endif   /* SQLITE_OMIT_WAL */
4387   return rc;
4388 }
4389 
4390 /*
4391 ** Open a read-transaction on the snapshot idendified by pSnapshot.
4392 */
4393 int sqlite3_snapshot_open(
4394   sqlite3 *db,
4395   const char *zDb,
4396   sqlite3_snapshot *pSnapshot
4397 ){
4398   int rc = SQLITE_ERROR;
4399 #ifndef SQLITE_OMIT_WAL
4400 
4401 #ifdef SQLITE_ENABLE_API_ARMOR
4402   if( !sqlite3SafetyCheckOk(db) ){
4403     return SQLITE_MISUSE_BKPT;
4404   }
4405 #endif
4406   sqlite3_mutex_enter(db->mutex);
4407   if( db->autoCommit==0 ){
4408     int iDb;
4409     iDb = sqlite3FindDbName(db, zDb);
4410     if( iDb==0 || iDb>1 ){
4411       Btree *pBt = db->aDb[iDb].pBt;
4412       if( sqlite3BtreeIsInTrans(pBt)==0 ){
4413         Pager *pPager = sqlite3BtreePager(pBt);
4414         int bUnlock = 0;
4415         if( sqlite3BtreeIsInReadTrans(pBt) ){
4416           if( db->nVdbeActive==0 ){
4417             rc = sqlite3PagerSnapshotCheck(pPager, pSnapshot);
4418             if( rc==SQLITE_OK ){
4419               bUnlock = 1;
4420               rc = sqlite3BtreeCommit(pBt);
4421             }
4422           }
4423         }else{
4424           rc = SQLITE_OK;
4425         }
4426         if( rc==SQLITE_OK ){
4427           rc = sqlite3PagerSnapshotOpen(pPager, pSnapshot);
4428         }
4429         if( rc==SQLITE_OK ){
4430           rc = sqlite3BtreeBeginTrans(pBt, 0, 0);
4431           sqlite3PagerSnapshotOpen(pPager, 0);
4432         }
4433         if( bUnlock ){
4434           sqlite3PagerSnapshotUnlock(pPager);
4435         }
4436       }
4437     }
4438   }
4439 
4440   sqlite3_mutex_leave(db->mutex);
4441 #endif   /* SQLITE_OMIT_WAL */
4442   return rc;
4443 }
4444 
4445 /*
4446 ** Recover as many snapshots as possible from the wal file associated with
4447 ** schema zDb of database db.
4448 */
4449 int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb){
4450   int rc = SQLITE_ERROR;
4451   int iDb;
4452 #ifndef SQLITE_OMIT_WAL
4453 
4454 #ifdef SQLITE_ENABLE_API_ARMOR
4455   if( !sqlite3SafetyCheckOk(db) ){
4456     return SQLITE_MISUSE_BKPT;
4457   }
4458 #endif
4459 
4460   sqlite3_mutex_enter(db->mutex);
4461   iDb = sqlite3FindDbName(db, zDb);
4462   if( iDb==0 || iDb>1 ){
4463     Btree *pBt = db->aDb[iDb].pBt;
4464     if( 0==sqlite3BtreeIsInReadTrans(pBt) ){
4465       rc = sqlite3BtreeBeginTrans(pBt, 0, 0);
4466       if( rc==SQLITE_OK ){
4467         rc = sqlite3PagerSnapshotRecover(sqlite3BtreePager(pBt));
4468         sqlite3BtreeCommit(pBt);
4469       }
4470     }
4471   }
4472   sqlite3_mutex_leave(db->mutex);
4473 #endif   /* SQLITE_OMIT_WAL */
4474   return rc;
4475 }
4476 
4477 /*
4478 ** Free a snapshot handle obtained from sqlite3_snapshot_get().
4479 */
4480 void sqlite3_snapshot_free(sqlite3_snapshot *pSnapshot){
4481   sqlite3_free(pSnapshot);
4482 }
4483 #endif /* SQLITE_ENABLE_SNAPSHOT */
4484 
4485 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
4486 /*
4487 ** Given the name of a compile-time option, return true if that option
4488 ** was used and false if not.
4489 **
4490 ** The name can optionally begin with "SQLITE_" but the "SQLITE_" prefix
4491 ** is not required for a match.
4492 */
4493 int sqlite3_compileoption_used(const char *zOptName){
4494   int i, n;
4495   int nOpt;
4496   const char **azCompileOpt;
4497 
4498 #if SQLITE_ENABLE_API_ARMOR
4499   if( zOptName==0 ){
4500     (void)SQLITE_MISUSE_BKPT;
4501     return 0;
4502   }
4503 #endif
4504 
4505   azCompileOpt = sqlite3CompileOptions(&nOpt);
4506 
4507   if( sqlite3StrNICmp(zOptName, "SQLITE_", 7)==0 ) zOptName += 7;
4508   n = sqlite3Strlen30(zOptName);
4509 
4510   /* Since nOpt is normally in single digits, a linear search is
4511   ** adequate. No need for a binary search. */
4512   for(i=0; i<nOpt; i++){
4513     if( sqlite3StrNICmp(zOptName, azCompileOpt[i], n)==0
4514      && sqlite3IsIdChar((unsigned char)azCompileOpt[i][n])==0
4515     ){
4516       return 1;
4517     }
4518   }
4519   return 0;
4520 }
4521 
4522 /*
4523 ** Return the N-th compile-time option string.  If N is out of range,
4524 ** return a NULL pointer.
4525 */
4526 const char *sqlite3_compileoption_get(int N){
4527   int nOpt;
4528   const char **azCompileOpt;
4529   azCompileOpt = sqlite3CompileOptions(&nOpt);
4530   if( N>=0 && N<nOpt ){
4531     return azCompileOpt[N];
4532   }
4533   return 0;
4534 }
4535 #endif /* SQLITE_OMIT_COMPILEOPTION_DIAGS */
4536