xref: /sqlite-3.40.0/src/main.c (revision 47d00872)
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 #ifdef SQLITE_ENABLE_ICU
26 # include "sqliteicu.h"
27 #endif
28 #ifdef SQLITE_ENABLE_JSON1
29 int sqlite3Json1Init(sqlite3*);
30 #endif
31 #ifdef SQLITE_ENABLE_FTS5
32 int sqlite3Fts5Init(sqlite3*);
33 #endif
34 
35 #ifndef SQLITE_AMALGAMATION
36 /* IMPLEMENTATION-OF: R-46656-45156 The sqlite3_version[] string constant
37 ** contains the text of SQLITE_VERSION macro.
38 */
39 const char sqlite3_version[] = SQLITE_VERSION;
40 #endif
41 
42 /* IMPLEMENTATION-OF: R-53536-42575 The sqlite3_libversion() function returns
43 ** a pointer to the to the sqlite3_version[] string constant.
44 */
45 const char *sqlite3_libversion(void){ return sqlite3_version; }
46 
47 /* IMPLEMENTATION-OF: R-63124-39300 The sqlite3_sourceid() function returns a
48 ** pointer to a string constant whose value is the same as the
49 ** SQLITE_SOURCE_ID C preprocessor macro.
50 */
51 const char *sqlite3_sourceid(void){ return SQLITE_SOURCE_ID; }
52 
53 /* IMPLEMENTATION-OF: R-35210-63508 The sqlite3_libversion_number() function
54 ** returns an integer equal to SQLITE_VERSION_NUMBER.
55 */
56 int sqlite3_libversion_number(void){ return SQLITE_VERSION_NUMBER; }
57 
58 /* IMPLEMENTATION-OF: R-20790-14025 The sqlite3_threadsafe() function returns
59 ** zero if and only if SQLite was compiled with mutexing code omitted due to
60 ** the SQLITE_THREADSAFE compile-time option being set to 0.
61 */
62 int sqlite3_threadsafe(void){ return SQLITE_THREADSAFE; }
63 
64 /*
65 ** When compiling the test fixture or with debugging enabled (on Win32),
66 ** this variable being set to non-zero will cause OSTRACE macros to emit
67 ** extra diagnostic information.
68 */
69 #ifdef SQLITE_HAVE_OS_TRACE
70 # ifndef SQLITE_DEBUG_OS_TRACE
71 #   define SQLITE_DEBUG_OS_TRACE 0
72 # endif
73   int sqlite3OSTrace = SQLITE_DEBUG_OS_TRACE;
74 #endif
75 
76 #if !defined(SQLITE_OMIT_TRACE) && defined(SQLITE_ENABLE_IOTRACE)
77 /*
78 ** If the following function pointer is not NULL and if
79 ** SQLITE_ENABLE_IOTRACE is enabled, then messages describing
80 ** I/O active are written using this function.  These messages
81 ** are intended for debugging activity only.
82 */
83 SQLITE_API void (SQLITE_CDECL *sqlite3IoTrace)(const char*, ...) = 0;
84 #endif
85 
86 /*
87 ** If the following global variable points to a string which is the
88 ** name of a directory, then that directory will be used to store
89 ** temporary files.
90 **
91 ** See also the "PRAGMA temp_store_directory" SQL command.
92 */
93 char *sqlite3_temp_directory = 0;
94 
95 /*
96 ** If the following global variable points to a string which is the
97 ** name of a directory, then that directory will be used to store
98 ** all database files specified with a relative pathname.
99 **
100 ** See also the "PRAGMA data_store_directory" SQL command.
101 */
102 char *sqlite3_data_directory = 0;
103 
104 /*
105 ** Initialize SQLite.
106 **
107 ** This routine must be called to initialize the memory allocation,
108 ** VFS, and mutex subsystems prior to doing any serious work with
109 ** SQLite.  But as long as you do not compile with SQLITE_OMIT_AUTOINIT
110 ** this routine will be called automatically by key routines such as
111 ** sqlite3_open().
112 **
113 ** This routine is a no-op except on its very first call for the process,
114 ** or for the first call after a call to sqlite3_shutdown.
115 **
116 ** The first thread to call this routine runs the initialization to
117 ** completion.  If subsequent threads call this routine before the first
118 ** thread has finished the initialization process, then the subsequent
119 ** threads must block until the first thread finishes with the initialization.
120 **
121 ** The first thread might call this routine recursively.  Recursive
122 ** calls to this routine should not block, of course.  Otherwise the
123 ** initialization process would never complete.
124 **
125 ** Let X be the first thread to enter this routine.  Let Y be some other
126 ** thread.  Then while the initial invocation of this routine by X is
127 ** incomplete, it is required that:
128 **
129 **    *  Calls to this routine from Y must block until the outer-most
130 **       call by X completes.
131 **
132 **    *  Recursive calls to this routine from thread X return immediately
133 **       without blocking.
134 */
135 int sqlite3_initialize(void){
136   MUTEX_LOGIC( sqlite3_mutex *pMaster; )       /* The main static mutex */
137   int rc;                                      /* Result code */
138 #ifdef SQLITE_EXTRA_INIT
139   int bRunExtraInit = 0;                       /* Extra initialization needed */
140 #endif
141 
142 #ifdef SQLITE_OMIT_WSD
143   rc = sqlite3_wsd_init(4096, 24);
144   if( rc!=SQLITE_OK ){
145     return rc;
146   }
147 #endif
148 
149   /* If the following assert() fails on some obscure processor/compiler
150   ** combination, the work-around is to set the correct pointer
151   ** size at compile-time using -DSQLITE_PTRSIZE=n compile-time option */
152   assert( SQLITE_PTRSIZE==sizeof(char*) );
153 
154   /* If SQLite is already completely initialized, then this call
155   ** to sqlite3_initialize() should be a no-op.  But the initialization
156   ** must be complete.  So isInit must not be set until the very end
157   ** of this routine.
158   */
159   if( sqlite3GlobalConfig.isInit ) return SQLITE_OK;
160 
161   /* Make sure the mutex subsystem is initialized.  If unable to
162   ** initialize the mutex subsystem, return early with the error.
163   ** If the system is so sick that we are unable to allocate a mutex,
164   ** there is not much SQLite is going to be able to do.
165   **
166   ** The mutex subsystem must take care of serializing its own
167   ** initialization.
168   */
169   rc = sqlite3MutexInit();
170   if( rc ) return rc;
171 
172   /* Initialize the malloc() system and the recursive pInitMutex mutex.
173   ** This operation is protected by the STATIC_MASTER mutex.  Note that
174   ** MutexAlloc() is called for a static mutex prior to initializing the
175   ** malloc subsystem - this implies that the allocation of a static
176   ** mutex must not require support from the malloc subsystem.
177   */
178   MUTEX_LOGIC( pMaster = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER); )
179   sqlite3_mutex_enter(pMaster);
180   sqlite3GlobalConfig.isMutexInit = 1;
181   if( !sqlite3GlobalConfig.isMallocInit ){
182     rc = sqlite3MallocInit();
183   }
184   if( rc==SQLITE_OK ){
185     sqlite3GlobalConfig.isMallocInit = 1;
186     if( !sqlite3GlobalConfig.pInitMutex ){
187       sqlite3GlobalConfig.pInitMutex =
188            sqlite3MutexAlloc(SQLITE_MUTEX_RECURSIVE);
189       if( sqlite3GlobalConfig.bCoreMutex && !sqlite3GlobalConfig.pInitMutex ){
190         rc = SQLITE_NOMEM_BKPT;
191       }
192     }
193   }
194   if( rc==SQLITE_OK ){
195     sqlite3GlobalConfig.nRefInitMutex++;
196   }
197   sqlite3_mutex_leave(pMaster);
198 
199   /* If rc is not SQLITE_OK at this point, then either the malloc
200   ** subsystem could not be initialized or the system failed to allocate
201   ** the pInitMutex mutex. Return an error in either case.  */
202   if( rc!=SQLITE_OK ){
203     return rc;
204   }
205 
206   /* Do the rest of the initialization under the recursive mutex so
207   ** that we will be able to handle recursive calls into
208   ** sqlite3_initialize().  The recursive calls normally come through
209   ** sqlite3_os_init() when it invokes sqlite3_vfs_register(), but other
210   ** recursive calls might also be possible.
211   **
212   ** IMPLEMENTATION-OF: R-00140-37445 SQLite automatically serializes calls
213   ** to the xInit method, so the xInit method need not be threadsafe.
214   **
215   ** The following mutex is what serializes access to the appdef pcache xInit
216   ** methods.  The sqlite3_pcache_methods.xInit() all is embedded in the
217   ** call to sqlite3PcacheInitialize().
218   */
219   sqlite3_mutex_enter(sqlite3GlobalConfig.pInitMutex);
220   if( sqlite3GlobalConfig.isInit==0 && sqlite3GlobalConfig.inProgress==0 ){
221     sqlite3GlobalConfig.inProgress = 1;
222 #ifdef SQLITE_ENABLE_SQLLOG
223     {
224       extern void sqlite3_init_sqllog(void);
225       sqlite3_init_sqllog();
226     }
227 #endif
228     memset(&sqlite3BuiltinFunctions, 0, sizeof(sqlite3BuiltinFunctions));
229     sqlite3RegisterBuiltinFunctions();
230     if( sqlite3GlobalConfig.isPCacheInit==0 ){
231       rc = sqlite3PcacheInitialize();
232     }
233     if( rc==SQLITE_OK ){
234       sqlite3GlobalConfig.isPCacheInit = 1;
235       rc = sqlite3OsInit();
236     }
237     if( rc==SQLITE_OK ){
238       sqlite3PCacheBufferSetup( sqlite3GlobalConfig.pPage,
239           sqlite3GlobalConfig.szPage, sqlite3GlobalConfig.nPage);
240       sqlite3GlobalConfig.isInit = 1;
241 #ifdef SQLITE_EXTRA_INIT
242       bRunExtraInit = 1;
243 #endif
244     }
245     sqlite3GlobalConfig.inProgress = 0;
246   }
247   sqlite3_mutex_leave(sqlite3GlobalConfig.pInitMutex);
248 
249   /* Go back under the static mutex and clean up the recursive
250   ** mutex to prevent a resource leak.
251   */
252   sqlite3_mutex_enter(pMaster);
253   sqlite3GlobalConfig.nRefInitMutex--;
254   if( sqlite3GlobalConfig.nRefInitMutex<=0 ){
255     assert( sqlite3GlobalConfig.nRefInitMutex==0 );
256     sqlite3_mutex_free(sqlite3GlobalConfig.pInitMutex);
257     sqlite3GlobalConfig.pInitMutex = 0;
258   }
259   sqlite3_mutex_leave(pMaster);
260 
261   /* The following is just a sanity check to make sure SQLite has
262   ** been compiled correctly.  It is important to run this code, but
263   ** we don't want to run it too often and soak up CPU cycles for no
264   ** reason.  So we run it once during initialization.
265   */
266 #ifndef NDEBUG
267 #ifndef SQLITE_OMIT_FLOATING_POINT
268   /* This section of code's only "output" is via assert() statements. */
269   if ( rc==SQLITE_OK ){
270     u64 x = (((u64)1)<<63)-1;
271     double y;
272     assert(sizeof(x)==8);
273     assert(sizeof(x)==sizeof(y));
274     memcpy(&y, &x, 8);
275     assert( sqlite3IsNaN(y) );
276   }
277 #endif
278 #endif
279 
280   /* Do extra initialization steps requested by the SQLITE_EXTRA_INIT
281   ** compile-time option.
282   */
283 #ifdef SQLITE_EXTRA_INIT
284   if( bRunExtraInit ){
285     int SQLITE_EXTRA_INIT(const char*);
286     rc = SQLITE_EXTRA_INIT(0);
287   }
288 #endif
289 
290   return rc;
291 }
292 
293 /*
294 ** Undo the effects of sqlite3_initialize().  Must not be called while
295 ** there are outstanding database connections or memory allocations or
296 ** while any part of SQLite is otherwise in use in any thread.  This
297 ** routine is not threadsafe.  But it is safe to invoke this routine
298 ** on when SQLite is already shut down.  If SQLite is already shut down
299 ** when this routine is invoked, then this routine is a harmless no-op.
300 */
301 int sqlite3_shutdown(void){
302 #ifdef SQLITE_OMIT_WSD
303   int rc = sqlite3_wsd_init(4096, 24);
304   if( rc!=SQLITE_OK ){
305     return rc;
306   }
307 #endif
308 
309   if( sqlite3GlobalConfig.isInit ){
310 #ifdef SQLITE_EXTRA_SHUTDOWN
311     void SQLITE_EXTRA_SHUTDOWN(void);
312     SQLITE_EXTRA_SHUTDOWN();
313 #endif
314     sqlite3_os_end();
315     sqlite3_reset_auto_extension();
316     sqlite3GlobalConfig.isInit = 0;
317   }
318   if( sqlite3GlobalConfig.isPCacheInit ){
319     sqlite3PcacheShutdown();
320     sqlite3GlobalConfig.isPCacheInit = 0;
321   }
322   if( sqlite3GlobalConfig.isMallocInit ){
323     sqlite3MallocEnd();
324     sqlite3GlobalConfig.isMallocInit = 0;
325 
326 #ifndef SQLITE_OMIT_SHUTDOWN_DIRECTORIES
327     /* The heap subsystem has now been shutdown and these values are supposed
328     ** to be NULL or point to memory that was obtained from sqlite3_malloc(),
329     ** which would rely on that heap subsystem; therefore, make sure these
330     ** values cannot refer to heap memory that was just invalidated when the
331     ** heap subsystem was shutdown.  This is only done if the current call to
332     ** this function resulted in the heap subsystem actually being shutdown.
333     */
334     sqlite3_data_directory = 0;
335     sqlite3_temp_directory = 0;
336 #endif
337   }
338   if( sqlite3GlobalConfig.isMutexInit ){
339     sqlite3MutexEnd();
340     sqlite3GlobalConfig.isMutexInit = 0;
341   }
342 
343   return SQLITE_OK;
344 }
345 
346 /*
347 ** This API allows applications to modify the global configuration of
348 ** the SQLite library at run-time.
349 **
350 ** This routine should only be called when there are no outstanding
351 ** database connections or memory allocations.  This routine is not
352 ** threadsafe.  Failure to heed these warnings can lead to unpredictable
353 ** behavior.
354 */
355 int sqlite3_config(int op, ...){
356   va_list ap;
357   int rc = SQLITE_OK;
358 
359   /* sqlite3_config() shall return SQLITE_MISUSE if it is invoked while
360   ** the SQLite library is in use. */
361   if( sqlite3GlobalConfig.isInit ) return SQLITE_MISUSE_BKPT;
362 
363   va_start(ap, op);
364   switch( op ){
365 
366     /* Mutex configuration options are only available in a threadsafe
367     ** compile.
368     */
369 #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0  /* IMP: R-54466-46756 */
370     case SQLITE_CONFIG_SINGLETHREAD: {
371       /* EVIDENCE-OF: R-02748-19096 This option sets the threading mode to
372       ** Single-thread. */
373       sqlite3GlobalConfig.bCoreMutex = 0;  /* Disable mutex on core */
374       sqlite3GlobalConfig.bFullMutex = 0;  /* Disable mutex on connections */
375       break;
376     }
377 #endif
378 #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-20520-54086 */
379     case SQLITE_CONFIG_MULTITHREAD: {
380       /* EVIDENCE-OF: R-14374-42468 This option sets the threading mode to
381       ** Multi-thread. */
382       sqlite3GlobalConfig.bCoreMutex = 1;  /* Enable mutex on core */
383       sqlite3GlobalConfig.bFullMutex = 0;  /* Disable mutex on connections */
384       break;
385     }
386 #endif
387 #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-59593-21810 */
388     case SQLITE_CONFIG_SERIALIZED: {
389       /* EVIDENCE-OF: R-41220-51800 This option sets the threading mode to
390       ** Serialized. */
391       sqlite3GlobalConfig.bCoreMutex = 1;  /* Enable mutex on core */
392       sqlite3GlobalConfig.bFullMutex = 1;  /* Enable mutex on connections */
393       break;
394     }
395 #endif
396 #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-63666-48755 */
397     case SQLITE_CONFIG_MUTEX: {
398       /* Specify an alternative mutex implementation */
399       sqlite3GlobalConfig.mutex = *va_arg(ap, sqlite3_mutex_methods*);
400       break;
401     }
402 #endif
403 #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-14450-37597 */
404     case SQLITE_CONFIG_GETMUTEX: {
405       /* Retrieve the current mutex implementation */
406       *va_arg(ap, sqlite3_mutex_methods*) = sqlite3GlobalConfig.mutex;
407       break;
408     }
409 #endif
410 
411     case SQLITE_CONFIG_MALLOC: {
412       /* EVIDENCE-OF: R-55594-21030 The SQLITE_CONFIG_MALLOC option takes a
413       ** single argument which is a pointer to an instance of the
414       ** sqlite3_mem_methods structure. The argument specifies alternative
415       ** low-level memory allocation routines to be used in place of the memory
416       ** allocation routines built into SQLite. */
417       sqlite3GlobalConfig.m = *va_arg(ap, sqlite3_mem_methods*);
418       break;
419     }
420     case SQLITE_CONFIG_GETMALLOC: {
421       /* EVIDENCE-OF: R-51213-46414 The SQLITE_CONFIG_GETMALLOC option takes a
422       ** single argument which is a pointer to an instance of the
423       ** sqlite3_mem_methods structure. The sqlite3_mem_methods structure is
424       ** filled with the currently defined memory allocation routines. */
425       if( sqlite3GlobalConfig.m.xMalloc==0 ) sqlite3MemSetDefault();
426       *va_arg(ap, sqlite3_mem_methods*) = sqlite3GlobalConfig.m;
427       break;
428     }
429     case SQLITE_CONFIG_MEMSTATUS: {
430       /* EVIDENCE-OF: R-61275-35157 The SQLITE_CONFIG_MEMSTATUS option takes
431       ** single argument of type int, interpreted as a boolean, which enables
432       ** or disables the collection of memory allocation statistics. */
433       sqlite3GlobalConfig.bMemstat = va_arg(ap, int);
434       break;
435     }
436     case SQLITE_CONFIG_SCRATCH: {
437       /* EVIDENCE-OF: R-08404-60887 There are three arguments to
438       ** SQLITE_CONFIG_SCRATCH: A pointer an 8-byte aligned memory buffer from
439       ** which the scratch allocations will be drawn, the size of each scratch
440       ** allocation (sz), and the maximum number of scratch allocations (N). */
441       sqlite3GlobalConfig.pScratch = va_arg(ap, void*);
442       sqlite3GlobalConfig.szScratch = va_arg(ap, int);
443       sqlite3GlobalConfig.nScratch = va_arg(ap, int);
444       break;
445     }
446     case SQLITE_CONFIG_PAGECACHE: {
447       /* EVIDENCE-OF: R-18761-36601 There are three arguments to
448       ** SQLITE_CONFIG_PAGECACHE: A pointer to 8-byte aligned memory (pMem),
449       ** the size of each page cache line (sz), and the number of cache lines
450       ** (N). */
451       sqlite3GlobalConfig.pPage = va_arg(ap, void*);
452       sqlite3GlobalConfig.szPage = va_arg(ap, int);
453       sqlite3GlobalConfig.nPage = va_arg(ap, int);
454       break;
455     }
456     case SQLITE_CONFIG_PCACHE_HDRSZ: {
457       /* EVIDENCE-OF: R-39100-27317 The SQLITE_CONFIG_PCACHE_HDRSZ option takes
458       ** a single parameter which is a pointer to an integer and writes into
459       ** that integer the number of extra bytes per page required for each page
460       ** in SQLITE_CONFIG_PAGECACHE. */
461       *va_arg(ap, int*) =
462           sqlite3HeaderSizeBtree() +
463           sqlite3HeaderSizePcache() +
464           sqlite3HeaderSizePcache1();
465       break;
466     }
467 
468     case SQLITE_CONFIG_PCACHE: {
469       /* no-op */
470       break;
471     }
472     case SQLITE_CONFIG_GETPCACHE: {
473       /* now an error */
474       rc = SQLITE_ERROR;
475       break;
476     }
477 
478     case SQLITE_CONFIG_PCACHE2: {
479       /* EVIDENCE-OF: R-63325-48378 The SQLITE_CONFIG_PCACHE2 option takes a
480       ** single argument which is a pointer to an sqlite3_pcache_methods2
481       ** object. This object specifies the interface to a custom page cache
482       ** implementation. */
483       sqlite3GlobalConfig.pcache2 = *va_arg(ap, sqlite3_pcache_methods2*);
484       break;
485     }
486     case SQLITE_CONFIG_GETPCACHE2: {
487       /* EVIDENCE-OF: R-22035-46182 The SQLITE_CONFIG_GETPCACHE2 option takes a
488       ** single argument which is a pointer to an sqlite3_pcache_methods2
489       ** object. SQLite copies of the current page cache implementation into
490       ** that object. */
491       if( sqlite3GlobalConfig.pcache2.xInit==0 ){
492         sqlite3PCacheSetDefault();
493       }
494       *va_arg(ap, sqlite3_pcache_methods2*) = sqlite3GlobalConfig.pcache2;
495       break;
496     }
497 
498 /* EVIDENCE-OF: R-06626-12911 The SQLITE_CONFIG_HEAP option is only
499 ** available if SQLite is compiled with either SQLITE_ENABLE_MEMSYS3 or
500 ** SQLITE_ENABLE_MEMSYS5 and returns SQLITE_ERROR if invoked otherwise. */
501 #if defined(SQLITE_ENABLE_MEMSYS3) || defined(SQLITE_ENABLE_MEMSYS5)
502     case SQLITE_CONFIG_HEAP: {
503       /* EVIDENCE-OF: R-19854-42126 There are three arguments to
504       ** SQLITE_CONFIG_HEAP: An 8-byte aligned pointer to the memory, the
505       ** number of bytes in the memory buffer, and the minimum allocation size.
506       */
507       sqlite3GlobalConfig.pHeap = va_arg(ap, void*);
508       sqlite3GlobalConfig.nHeap = va_arg(ap, int);
509       sqlite3GlobalConfig.mnReq = va_arg(ap, int);
510 
511       if( sqlite3GlobalConfig.mnReq<1 ){
512         sqlite3GlobalConfig.mnReq = 1;
513       }else if( sqlite3GlobalConfig.mnReq>(1<<12) ){
514         /* cap min request size at 2^12 */
515         sqlite3GlobalConfig.mnReq = (1<<12);
516       }
517 
518       if( sqlite3GlobalConfig.pHeap==0 ){
519         /* EVIDENCE-OF: R-49920-60189 If the first pointer (the memory pointer)
520         ** is NULL, then SQLite reverts to using its default memory allocator
521         ** (the system malloc() implementation), undoing any prior invocation of
522         ** SQLITE_CONFIG_MALLOC.
523         **
524         ** Setting sqlite3GlobalConfig.m to all zeros will cause malloc to
525         ** revert to its default implementation when sqlite3_initialize() is run
526         */
527         memset(&sqlite3GlobalConfig.m, 0, sizeof(sqlite3GlobalConfig.m));
528       }else{
529         /* EVIDENCE-OF: R-61006-08918 If the memory pointer is not NULL then the
530         ** alternative memory allocator is engaged to handle all of SQLites
531         ** memory allocation needs. */
532 #ifdef SQLITE_ENABLE_MEMSYS3
533         sqlite3GlobalConfig.m = *sqlite3MemGetMemsys3();
534 #endif
535 #ifdef SQLITE_ENABLE_MEMSYS5
536         sqlite3GlobalConfig.m = *sqlite3MemGetMemsys5();
537 #endif
538       }
539       break;
540     }
541 #endif
542 
543     case SQLITE_CONFIG_LOOKASIDE: {
544       sqlite3GlobalConfig.szLookaside = va_arg(ap, int);
545       sqlite3GlobalConfig.nLookaside = va_arg(ap, int);
546       break;
547     }
548 
549     /* Record a pointer to the logger function and its first argument.
550     ** The default is NULL.  Logging is disabled if the function pointer is
551     ** NULL.
552     */
553     case SQLITE_CONFIG_LOG: {
554       /* MSVC is picky about pulling func ptrs from va lists.
555       ** http://support.microsoft.com/kb/47961
556       ** sqlite3GlobalConfig.xLog = va_arg(ap, void(*)(void*,int,const char*));
557       */
558       typedef void(*LOGFUNC_t)(void*,int,const char*);
559       sqlite3GlobalConfig.xLog = va_arg(ap, LOGFUNC_t);
560       sqlite3GlobalConfig.pLogArg = va_arg(ap, void*);
561       break;
562     }
563 
564     /* EVIDENCE-OF: R-55548-33817 The compile-time setting for URI filenames
565     ** can be changed at start-time using the
566     ** sqlite3_config(SQLITE_CONFIG_URI,1) or
567     ** sqlite3_config(SQLITE_CONFIG_URI,0) configuration calls.
568     */
569     case SQLITE_CONFIG_URI: {
570       /* EVIDENCE-OF: R-25451-61125 The SQLITE_CONFIG_URI option takes a single
571       ** argument of type int. If non-zero, then URI handling is globally
572       ** enabled. If the parameter is zero, then URI handling is globally
573       ** disabled. */
574       sqlite3GlobalConfig.bOpenUri = va_arg(ap, int);
575       break;
576     }
577 
578     case SQLITE_CONFIG_COVERING_INDEX_SCAN: {
579       /* EVIDENCE-OF: R-36592-02772 The SQLITE_CONFIG_COVERING_INDEX_SCAN
580       ** option takes a single integer argument which is interpreted as a
581       ** boolean in order to enable or disable the use of covering indices for
582       ** full table scans in the query optimizer. */
583       sqlite3GlobalConfig.bUseCis = va_arg(ap, int);
584       break;
585     }
586 
587 #ifdef SQLITE_ENABLE_SQLLOG
588     case SQLITE_CONFIG_SQLLOG: {
589       typedef void(*SQLLOGFUNC_t)(void*, sqlite3*, const char*, int);
590       sqlite3GlobalConfig.xSqllog = va_arg(ap, SQLLOGFUNC_t);
591       sqlite3GlobalConfig.pSqllogArg = va_arg(ap, void *);
592       break;
593     }
594 #endif
595 
596     case SQLITE_CONFIG_MMAP_SIZE: {
597       /* EVIDENCE-OF: R-58063-38258 SQLITE_CONFIG_MMAP_SIZE takes two 64-bit
598       ** integer (sqlite3_int64) values that are the default mmap size limit
599       ** (the default setting for PRAGMA mmap_size) and the maximum allowed
600       ** mmap size limit. */
601       sqlite3_int64 szMmap = va_arg(ap, sqlite3_int64);
602       sqlite3_int64 mxMmap = va_arg(ap, sqlite3_int64);
603       /* EVIDENCE-OF: R-53367-43190 If either argument to this option is
604       ** negative, then that argument is changed to its compile-time default.
605       **
606       ** EVIDENCE-OF: R-34993-45031 The maximum allowed mmap size will be
607       ** silently truncated if necessary so that it does not exceed the
608       ** compile-time maximum mmap size set by the SQLITE_MAX_MMAP_SIZE
609       ** compile-time option.
610       */
611       if( mxMmap<0 || mxMmap>SQLITE_MAX_MMAP_SIZE ){
612         mxMmap = SQLITE_MAX_MMAP_SIZE;
613       }
614       if( szMmap<0 ) szMmap = SQLITE_DEFAULT_MMAP_SIZE;
615       if( szMmap>mxMmap) szMmap = mxMmap;
616       sqlite3GlobalConfig.mxMmap = mxMmap;
617       sqlite3GlobalConfig.szMmap = szMmap;
618       break;
619     }
620 
621 #if SQLITE_OS_WIN && defined(SQLITE_WIN32_MALLOC) /* IMP: R-04780-55815 */
622     case SQLITE_CONFIG_WIN32_HEAPSIZE: {
623       /* EVIDENCE-OF: R-34926-03360 SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit
624       ** unsigned integer value that specifies the maximum size of the created
625       ** heap. */
626       sqlite3GlobalConfig.nHeap = va_arg(ap, int);
627       break;
628     }
629 #endif
630 
631     case SQLITE_CONFIG_PMASZ: {
632       sqlite3GlobalConfig.szPma = va_arg(ap, unsigned int);
633       break;
634     }
635 
636     case SQLITE_CONFIG_STMTJRNL_SPILL: {
637       sqlite3GlobalConfig.nStmtSpill = va_arg(ap, int);
638       break;
639     }
640 
641     default: {
642       rc = SQLITE_ERROR;
643       break;
644     }
645   }
646   va_end(ap);
647   return rc;
648 }
649 
650 /*
651 ** Set up the lookaside buffers for a database connection.
652 ** Return SQLITE_OK on success.
653 ** If lookaside is already active, return SQLITE_BUSY.
654 **
655 ** The sz parameter is the number of bytes in each lookaside slot.
656 ** The cnt parameter is the number of slots.  If pStart is NULL the
657 ** space for the lookaside memory is obtained from sqlite3_malloc().
658 ** If pStart is not NULL then it is sz*cnt bytes of memory to use for
659 ** the lookaside memory.
660 */
661 static int setupLookaside(sqlite3 *db, void *pBuf, int sz, int cnt){
662 #ifndef SQLITE_OMIT_LOOKASIDE
663   void *pStart;
664   if( db->lookaside.nOut ){
665     return SQLITE_BUSY;
666   }
667   /* Free any existing lookaside buffer for this handle before
668   ** allocating a new one so we don't have to have space for
669   ** both at the same time.
670   */
671   if( db->lookaside.bMalloced ){
672     sqlite3_free(db->lookaside.pStart);
673   }
674   /* The size of a lookaside slot after ROUNDDOWN8 needs to be larger
675   ** than a pointer to be useful.
676   */
677   sz = ROUNDDOWN8(sz);  /* IMP: R-33038-09382 */
678   if( sz<=(int)sizeof(LookasideSlot*) ) sz = 0;
679   if( cnt<0 ) cnt = 0;
680   if( sz==0 || cnt==0 ){
681     sz = 0;
682     pStart = 0;
683   }else if( pBuf==0 ){
684     sqlite3BeginBenignMalloc();
685     pStart = sqlite3Malloc( sz*cnt );  /* IMP: R-61949-35727 */
686     sqlite3EndBenignMalloc();
687     if( pStart ) cnt = sqlite3MallocSize(pStart)/sz;
688   }else{
689     pStart = pBuf;
690   }
691   db->lookaside.pStart = pStart;
692   db->lookaside.pFree = 0;
693   db->lookaside.sz = (u16)sz;
694   if( pStart ){
695     int i;
696     LookasideSlot *p;
697     assert( sz > (int)sizeof(LookasideSlot*) );
698     p = (LookasideSlot*)pStart;
699     for(i=cnt-1; i>=0; i--){
700       p->pNext = db->lookaside.pFree;
701       db->lookaside.pFree = p;
702       p = (LookasideSlot*)&((u8*)p)[sz];
703     }
704     db->lookaside.pEnd = p;
705     db->lookaside.bDisable = 0;
706     db->lookaside.bMalloced = pBuf==0 ?1:0;
707   }else{
708     db->lookaside.pStart = db;
709     db->lookaside.pEnd = db;
710     db->lookaside.bDisable = 1;
711     db->lookaside.bMalloced = 0;
712   }
713 #endif /* SQLITE_OMIT_LOOKASIDE */
714   return SQLITE_OK;
715 }
716 
717 /*
718 ** Return the mutex associated with a database connection.
719 */
720 sqlite3_mutex *sqlite3_db_mutex(sqlite3 *db){
721 #ifdef SQLITE_ENABLE_API_ARMOR
722   if( !sqlite3SafetyCheckOk(db) ){
723     (void)SQLITE_MISUSE_BKPT;
724     return 0;
725   }
726 #endif
727   return db->mutex;
728 }
729 
730 /*
731 ** Free up as much memory as we can from the given database
732 ** connection.
733 */
734 int sqlite3_db_release_memory(sqlite3 *db){
735   int i;
736 
737 #ifdef SQLITE_ENABLE_API_ARMOR
738   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
739 #endif
740   sqlite3_mutex_enter(db->mutex);
741   sqlite3BtreeEnterAll(db);
742   for(i=0; i<db->nDb; i++){
743     Btree *pBt = db->aDb[i].pBt;
744     if( pBt ){
745       Pager *pPager = sqlite3BtreePager(pBt);
746       sqlite3PagerShrink(pPager);
747     }
748   }
749   sqlite3BtreeLeaveAll(db);
750   sqlite3_mutex_leave(db->mutex);
751   return SQLITE_OK;
752 }
753 
754 /*
755 ** Flush any dirty pages in the pager-cache for any attached database
756 ** to disk.
757 */
758 int sqlite3_db_cacheflush(sqlite3 *db){
759   int i;
760   int rc = SQLITE_OK;
761   int bSeenBusy = 0;
762 
763 #ifdef SQLITE_ENABLE_API_ARMOR
764   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
765 #endif
766   sqlite3_mutex_enter(db->mutex);
767   sqlite3BtreeEnterAll(db);
768   for(i=0; rc==SQLITE_OK && i<db->nDb; i++){
769     Btree *pBt = db->aDb[i].pBt;
770     if( pBt && sqlite3BtreeIsInTrans(pBt) ){
771       Pager *pPager = sqlite3BtreePager(pBt);
772       rc = sqlite3PagerFlush(pPager);
773       if( rc==SQLITE_BUSY ){
774         bSeenBusy = 1;
775         rc = SQLITE_OK;
776       }
777     }
778   }
779   sqlite3BtreeLeaveAll(db);
780   sqlite3_mutex_leave(db->mutex);
781   return ((rc==SQLITE_OK && bSeenBusy) ? SQLITE_BUSY : rc);
782 }
783 
784 /*
785 ** Configuration settings for an individual database connection
786 */
787 int sqlite3_db_config(sqlite3 *db, int op, ...){
788   va_list ap;
789   int rc;
790   va_start(ap, op);
791   switch( op ){
792     case SQLITE_DBCONFIG_MAINDBNAME: {
793       db->aDb[0].zDbSName = va_arg(ap,char*);
794       rc = SQLITE_OK;
795       break;
796     }
797     case SQLITE_DBCONFIG_LOOKASIDE: {
798       void *pBuf = va_arg(ap, void*); /* IMP: R-26835-10964 */
799       int sz = va_arg(ap, int);       /* IMP: R-47871-25994 */
800       int cnt = va_arg(ap, int);      /* IMP: R-04460-53386 */
801       rc = setupLookaside(db, pBuf, sz, cnt);
802       break;
803     }
804     default: {
805       static const struct {
806         int op;      /* The opcode */
807         u32 mask;    /* Mask of the bit in sqlite3.flags to set/clear */
808       } aFlagOp[] = {
809         { SQLITE_DBCONFIG_ENABLE_FKEY,           SQLITE_ForeignKeys    },
810         { SQLITE_DBCONFIG_ENABLE_TRIGGER,        SQLITE_EnableTrigger  },
811         { SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER, SQLITE_Fts3Tokenizer  },
812         { SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION, SQLITE_LoadExtension  },
813       };
814       unsigned int i;
815       rc = SQLITE_ERROR; /* IMP: R-42790-23372 */
816       for(i=0; i<ArraySize(aFlagOp); i++){
817         if( aFlagOp[i].op==op ){
818           int onoff = va_arg(ap, int);
819           int *pRes = va_arg(ap, int*);
820           int oldFlags = db->flags;
821           if( onoff>0 ){
822             db->flags |= aFlagOp[i].mask;
823           }else if( onoff==0 ){
824             db->flags &= ~aFlagOp[i].mask;
825           }
826           if( oldFlags!=db->flags ){
827             sqlite3ExpirePreparedStatements(db);
828           }
829           if( pRes ){
830             *pRes = (db->flags & aFlagOp[i].mask)!=0;
831           }
832           rc = SQLITE_OK;
833           break;
834         }
835       }
836       break;
837     }
838   }
839   va_end(ap);
840   return rc;
841 }
842 
843 
844 /*
845 ** Return true if the buffer z[0..n-1] contains all spaces.
846 */
847 static int allSpaces(const char *z, int n){
848   while( n>0 && z[n-1]==' ' ){ n--; }
849   return n==0;
850 }
851 
852 /*
853 ** This is the default collating function named "BINARY" which is always
854 ** available.
855 **
856 ** If the padFlag argument is not NULL then space padding at the end
857 ** of strings is ignored.  This implements the RTRIM collation.
858 */
859 static int binCollFunc(
860   void *padFlag,
861   int nKey1, const void *pKey1,
862   int nKey2, const void *pKey2
863 ){
864   int rc, n;
865   n = nKey1<nKey2 ? nKey1 : nKey2;
866   /* EVIDENCE-OF: R-65033-28449 The built-in BINARY collation compares
867   ** strings byte by byte using the memcmp() function from the standard C
868   ** library. */
869   rc = memcmp(pKey1, pKey2, n);
870   if( rc==0 ){
871     if( padFlag
872      && allSpaces(((char*)pKey1)+n, nKey1-n)
873      && allSpaces(((char*)pKey2)+n, nKey2-n)
874     ){
875       /* EVIDENCE-OF: R-31624-24737 RTRIM is like BINARY except that extra
876       ** spaces at the end of either string do not change the result. In other
877       ** words, strings will compare equal to one another as long as they
878       ** differ only in the number of spaces at the end.
879       */
880     }else{
881       rc = nKey1 - nKey2;
882     }
883   }
884   return rc;
885 }
886 
887 /*
888 ** Another built-in collating sequence: NOCASE.
889 **
890 ** This collating sequence is intended to be used for "case independent
891 ** comparison". SQLite's knowledge of upper and lower case equivalents
892 ** extends only to the 26 characters used in the English language.
893 **
894 ** At the moment there is only a UTF-8 implementation.
895 */
896 static int nocaseCollatingFunc(
897   void *NotUsed,
898   int nKey1, const void *pKey1,
899   int nKey2, const void *pKey2
900 ){
901   int r = sqlite3StrNICmp(
902       (const char *)pKey1, (const char *)pKey2, (nKey1<nKey2)?nKey1:nKey2);
903   UNUSED_PARAMETER(NotUsed);
904   if( 0==r ){
905     r = nKey1-nKey2;
906   }
907   return r;
908 }
909 
910 /*
911 ** Return the ROWID of the most recent insert
912 */
913 sqlite_int64 sqlite3_last_insert_rowid(sqlite3 *db){
914 #ifdef SQLITE_ENABLE_API_ARMOR
915   if( !sqlite3SafetyCheckOk(db) ){
916     (void)SQLITE_MISUSE_BKPT;
917     return 0;
918   }
919 #endif
920   return db->lastRowid;
921 }
922 
923 /*
924 ** Return the number of changes in the most recent call to sqlite3_exec().
925 */
926 int sqlite3_changes(sqlite3 *db){
927 #ifdef SQLITE_ENABLE_API_ARMOR
928   if( !sqlite3SafetyCheckOk(db) ){
929     (void)SQLITE_MISUSE_BKPT;
930     return 0;
931   }
932 #endif
933   return db->nChange;
934 }
935 
936 /*
937 ** Return the number of changes since the database handle was opened.
938 */
939 int sqlite3_total_changes(sqlite3 *db){
940 #ifdef SQLITE_ENABLE_API_ARMOR
941   if( !sqlite3SafetyCheckOk(db) ){
942     (void)SQLITE_MISUSE_BKPT;
943     return 0;
944   }
945 #endif
946   return db->nTotalChange;
947 }
948 
949 /*
950 ** Close all open savepoints. This function only manipulates fields of the
951 ** database handle object, it does not close any savepoints that may be open
952 ** at the b-tree/pager level.
953 */
954 void sqlite3CloseSavepoints(sqlite3 *db){
955   while( db->pSavepoint ){
956     Savepoint *pTmp = db->pSavepoint;
957     db->pSavepoint = pTmp->pNext;
958     sqlite3DbFree(db, pTmp);
959   }
960   db->nSavepoint = 0;
961   db->nStatement = 0;
962   db->isTransactionSavepoint = 0;
963 }
964 
965 /*
966 ** Invoke the destructor function associated with FuncDef p, if any. Except,
967 ** if this is not the last copy of the function, do not invoke it. Multiple
968 ** copies of a single function are created when create_function() is called
969 ** with SQLITE_ANY as the encoding.
970 */
971 static void functionDestroy(sqlite3 *db, FuncDef *p){
972   FuncDestructor *pDestructor = p->u.pDestructor;
973   if( pDestructor ){
974     pDestructor->nRef--;
975     if( pDestructor->nRef==0 ){
976       pDestructor->xDestroy(pDestructor->pUserData);
977       sqlite3DbFree(db, pDestructor);
978     }
979   }
980 }
981 
982 /*
983 ** Disconnect all sqlite3_vtab objects that belong to database connection
984 ** db. This is called when db is being closed.
985 */
986 static void disconnectAllVtab(sqlite3 *db){
987 #ifndef SQLITE_OMIT_VIRTUALTABLE
988   int i;
989   HashElem *p;
990   sqlite3BtreeEnterAll(db);
991   for(i=0; i<db->nDb; i++){
992     Schema *pSchema = db->aDb[i].pSchema;
993     if( db->aDb[i].pSchema ){
994       for(p=sqliteHashFirst(&pSchema->tblHash); p; p=sqliteHashNext(p)){
995         Table *pTab = (Table *)sqliteHashData(p);
996         if( IsVirtual(pTab) ) sqlite3VtabDisconnect(db, pTab);
997       }
998     }
999   }
1000   for(p=sqliteHashFirst(&db->aModule); p; p=sqliteHashNext(p)){
1001     Module *pMod = (Module *)sqliteHashData(p);
1002     if( pMod->pEpoTab ){
1003       sqlite3VtabDisconnect(db, pMod->pEpoTab);
1004     }
1005   }
1006   sqlite3VtabUnlockList(db);
1007   sqlite3BtreeLeaveAll(db);
1008 #else
1009   UNUSED_PARAMETER(db);
1010 #endif
1011 }
1012 
1013 /*
1014 ** Return TRUE if database connection db has unfinalized prepared
1015 ** statements or unfinished sqlite3_backup objects.
1016 */
1017 static int connectionIsBusy(sqlite3 *db){
1018   int j;
1019   assert( sqlite3_mutex_held(db->mutex) );
1020   if( db->pVdbe ) return 1;
1021   for(j=0; j<db->nDb; j++){
1022     Btree *pBt = db->aDb[j].pBt;
1023     if( pBt && sqlite3BtreeIsInBackup(pBt) ) return 1;
1024   }
1025   return 0;
1026 }
1027 
1028 /*
1029 ** Close an existing SQLite database
1030 */
1031 static int sqlite3Close(sqlite3 *db, int forceZombie){
1032   if( !db ){
1033     /* EVIDENCE-OF: R-63257-11740 Calling sqlite3_close() or
1034     ** sqlite3_close_v2() with a NULL pointer argument is a harmless no-op. */
1035     return SQLITE_OK;
1036   }
1037   if( !sqlite3SafetyCheckSickOrOk(db) ){
1038     return SQLITE_MISUSE_BKPT;
1039   }
1040   sqlite3_mutex_enter(db->mutex);
1041   if( db->mTrace & SQLITE_TRACE_CLOSE ){
1042     db->xTrace(SQLITE_TRACE_CLOSE, db->pTraceArg, db, 0);
1043   }
1044 
1045   /* Force xDisconnect calls on all virtual tables */
1046   disconnectAllVtab(db);
1047 
1048   /* If a transaction is open, the disconnectAllVtab() call above
1049   ** will not have called the xDisconnect() method on any virtual
1050   ** tables in the db->aVTrans[] array. The following sqlite3VtabRollback()
1051   ** call will do so. We need to do this before the check for active
1052   ** SQL statements below, as the v-table implementation may be storing
1053   ** some prepared statements internally.
1054   */
1055   sqlite3VtabRollback(db);
1056 
1057   /* Legacy behavior (sqlite3_close() behavior) is to return
1058   ** SQLITE_BUSY if the connection can not be closed immediately.
1059   */
1060   if( !forceZombie && connectionIsBusy(db) ){
1061     sqlite3ErrorWithMsg(db, SQLITE_BUSY, "unable to close due to unfinalized "
1062        "statements or unfinished backups");
1063     sqlite3_mutex_leave(db->mutex);
1064     return SQLITE_BUSY;
1065   }
1066 
1067 #ifdef SQLITE_ENABLE_SQLLOG
1068   if( sqlite3GlobalConfig.xSqllog ){
1069     /* Closing the handle. Fourth parameter is passed the value 2. */
1070     sqlite3GlobalConfig.xSqllog(sqlite3GlobalConfig.pSqllogArg, db, 0, 2);
1071   }
1072 #endif
1073 
1074   /* Convert the connection into a zombie and then close it.
1075   */
1076   db->magic = SQLITE_MAGIC_ZOMBIE;
1077   sqlite3LeaveMutexAndCloseZombie(db);
1078   return SQLITE_OK;
1079 }
1080 
1081 /*
1082 ** Two variations on the public interface for closing a database
1083 ** connection. The sqlite3_close() version returns SQLITE_BUSY and
1084 ** leaves the connection option if there are unfinalized prepared
1085 ** statements or unfinished sqlite3_backups.  The sqlite3_close_v2()
1086 ** version forces the connection to become a zombie if there are
1087 ** unclosed resources, and arranges for deallocation when the last
1088 ** prepare statement or sqlite3_backup closes.
1089 */
1090 int sqlite3_close(sqlite3 *db){ return sqlite3Close(db,0); }
1091 int sqlite3_close_v2(sqlite3 *db){ return sqlite3Close(db,1); }
1092 
1093 
1094 /*
1095 ** Close the mutex on database connection db.
1096 **
1097 ** Furthermore, if database connection db is a zombie (meaning that there
1098 ** has been a prior call to sqlite3_close(db) or sqlite3_close_v2(db)) and
1099 ** every sqlite3_stmt has now been finalized and every sqlite3_backup has
1100 ** finished, then free all resources.
1101 */
1102 void sqlite3LeaveMutexAndCloseZombie(sqlite3 *db){
1103   HashElem *i;                    /* Hash table iterator */
1104   int j;
1105 
1106   /* If there are outstanding sqlite3_stmt or sqlite3_backup objects
1107   ** or if the connection has not yet been closed by sqlite3_close_v2(),
1108   ** then just leave the mutex and return.
1109   */
1110   if( db->magic!=SQLITE_MAGIC_ZOMBIE || connectionIsBusy(db) ){
1111     sqlite3_mutex_leave(db->mutex);
1112     return;
1113   }
1114 
1115   /* If we reach this point, it means that the database connection has
1116   ** closed all sqlite3_stmt and sqlite3_backup objects and has been
1117   ** passed to sqlite3_close (meaning that it is a zombie).  Therefore,
1118   ** go ahead and free all resources.
1119   */
1120 
1121   /* If a transaction is open, roll it back. This also ensures that if
1122   ** any database schemas have been modified by an uncommitted transaction
1123   ** they are reset. And that the required b-tree mutex is held to make
1124   ** the pager rollback and schema reset an atomic operation. */
1125   sqlite3RollbackAll(db, SQLITE_OK);
1126 
1127   /* Free any outstanding Savepoint structures. */
1128   sqlite3CloseSavepoints(db);
1129 
1130   /* Close all database connections */
1131   for(j=0; j<db->nDb; j++){
1132     struct Db *pDb = &db->aDb[j];
1133     if( pDb->pBt ){
1134       sqlite3BtreeClose(pDb->pBt);
1135       pDb->pBt = 0;
1136       if( j!=1 ){
1137         pDb->pSchema = 0;
1138       }
1139     }
1140   }
1141   /* Clear the TEMP schema separately and last */
1142   if( db->aDb[1].pSchema ){
1143     sqlite3SchemaClear(db->aDb[1].pSchema);
1144   }
1145   sqlite3VtabUnlockList(db);
1146 
1147   /* Free up the array of auxiliary databases */
1148   sqlite3CollapseDatabaseArray(db);
1149   assert( db->nDb<=2 );
1150   assert( db->aDb==db->aDbStatic );
1151 
1152   /* Tell the code in notify.c that the connection no longer holds any
1153   ** locks and does not require any further unlock-notify callbacks.
1154   */
1155   sqlite3ConnectionClosed(db);
1156 
1157   for(i=sqliteHashFirst(&db->aFunc); i; i=sqliteHashNext(i)){
1158     FuncDef *pNext, *p;
1159     p = sqliteHashData(i);
1160     do{
1161       functionDestroy(db, p);
1162       pNext = p->pNext;
1163       sqlite3DbFree(db, p);
1164       p = pNext;
1165     }while( p );
1166   }
1167   sqlite3HashClear(&db->aFunc);
1168   for(i=sqliteHashFirst(&db->aCollSeq); i; i=sqliteHashNext(i)){
1169     CollSeq *pColl = (CollSeq *)sqliteHashData(i);
1170     /* Invoke any destructors registered for collation sequence user data. */
1171     for(j=0; j<3; j++){
1172       if( pColl[j].xDel ){
1173         pColl[j].xDel(pColl[j].pUser);
1174       }
1175     }
1176     sqlite3DbFree(db, pColl);
1177   }
1178   sqlite3HashClear(&db->aCollSeq);
1179 #ifndef SQLITE_OMIT_VIRTUALTABLE
1180   for(i=sqliteHashFirst(&db->aModule); i; i=sqliteHashNext(i)){
1181     Module *pMod = (Module *)sqliteHashData(i);
1182     if( pMod->xDestroy ){
1183       pMod->xDestroy(pMod->pAux);
1184     }
1185     sqlite3VtabEponymousTableClear(db, pMod);
1186     sqlite3DbFree(db, pMod);
1187   }
1188   sqlite3HashClear(&db->aModule);
1189 #endif
1190 
1191   sqlite3Error(db, SQLITE_OK); /* Deallocates any cached error strings. */
1192   sqlite3ValueFree(db->pErr);
1193   sqlite3CloseExtensions(db);
1194 #if SQLITE_USER_AUTHENTICATION
1195   sqlite3_free(db->auth.zAuthUser);
1196   sqlite3_free(db->auth.zAuthPW);
1197 #endif
1198 
1199   db->magic = SQLITE_MAGIC_ERROR;
1200 
1201   /* The temp-database schema is allocated differently from the other schema
1202   ** objects (using sqliteMalloc() directly, instead of sqlite3BtreeSchema()).
1203   ** So it needs to be freed here. Todo: Why not roll the temp schema into
1204   ** the same sqliteMalloc() as the one that allocates the database
1205   ** structure?
1206   */
1207   sqlite3DbFree(db, db->aDb[1].pSchema);
1208   sqlite3_mutex_leave(db->mutex);
1209   db->magic = SQLITE_MAGIC_CLOSED;
1210   sqlite3_mutex_free(db->mutex);
1211   assert( db->lookaside.nOut==0 );  /* Fails on a lookaside memory leak */
1212   if( db->lookaside.bMalloced ){
1213     sqlite3_free(db->lookaside.pStart);
1214   }
1215   sqlite3_free(db);
1216 }
1217 
1218 /*
1219 ** Rollback all database files.  If tripCode is not SQLITE_OK, then
1220 ** any write cursors are invalidated ("tripped" - as in "tripping a circuit
1221 ** breaker") and made to return tripCode if there are any further
1222 ** attempts to use that cursor.  Read cursors remain open and valid
1223 ** but are "saved" in case the table pages are moved around.
1224 */
1225 void sqlite3RollbackAll(sqlite3 *db, int tripCode){
1226   int i;
1227   int inTrans = 0;
1228   int schemaChange;
1229   assert( sqlite3_mutex_held(db->mutex) );
1230   sqlite3BeginBenignMalloc();
1231 
1232   /* Obtain all b-tree mutexes before making any calls to BtreeRollback().
1233   ** This is important in case the transaction being rolled back has
1234   ** modified the database schema. If the b-tree mutexes are not taken
1235   ** here, then another shared-cache connection might sneak in between
1236   ** the database rollback and schema reset, which can cause false
1237   ** corruption reports in some cases.  */
1238   sqlite3BtreeEnterAll(db);
1239   schemaChange = (db->flags & SQLITE_InternChanges)!=0 && db->init.busy==0;
1240 
1241   for(i=0; i<db->nDb; i++){
1242     Btree *p = db->aDb[i].pBt;
1243     if( p ){
1244       if( sqlite3BtreeIsInTrans(p) ){
1245         inTrans = 1;
1246       }
1247       sqlite3BtreeRollback(p, tripCode, !schemaChange);
1248     }
1249   }
1250   sqlite3VtabRollback(db);
1251   sqlite3EndBenignMalloc();
1252 
1253   if( (db->flags&SQLITE_InternChanges)!=0 && db->init.busy==0 ){
1254     sqlite3ExpirePreparedStatements(db);
1255     sqlite3ResetAllSchemasOfConnection(db);
1256   }
1257   sqlite3BtreeLeaveAll(db);
1258 
1259   /* Any deferred constraint violations have now been resolved. */
1260   db->nDeferredCons = 0;
1261   db->nDeferredImmCons = 0;
1262   db->flags &= ~SQLITE_DeferFKs;
1263 
1264   /* If one has been configured, invoke the rollback-hook callback */
1265   if( db->xRollbackCallback && (inTrans || !db->autoCommit) ){
1266     db->xRollbackCallback(db->pRollbackArg);
1267   }
1268 }
1269 
1270 /*
1271 ** Return a static string containing the name corresponding to the error code
1272 ** specified in the argument.
1273 */
1274 #if defined(SQLITE_NEED_ERR_NAME)
1275 const char *sqlite3ErrName(int rc){
1276   const char *zName = 0;
1277   int i, origRc = rc;
1278   for(i=0; i<2 && zName==0; i++, rc &= 0xff){
1279     switch( rc ){
1280       case SQLITE_OK:                 zName = "SQLITE_OK";                break;
1281       case SQLITE_ERROR:              zName = "SQLITE_ERROR";             break;
1282       case SQLITE_INTERNAL:           zName = "SQLITE_INTERNAL";          break;
1283       case SQLITE_PERM:               zName = "SQLITE_PERM";              break;
1284       case SQLITE_ABORT:              zName = "SQLITE_ABORT";             break;
1285       case SQLITE_ABORT_ROLLBACK:     zName = "SQLITE_ABORT_ROLLBACK";    break;
1286       case SQLITE_BUSY:               zName = "SQLITE_BUSY";              break;
1287       case SQLITE_BUSY_RECOVERY:      zName = "SQLITE_BUSY_RECOVERY";     break;
1288       case SQLITE_BUSY_SNAPSHOT:      zName = "SQLITE_BUSY_SNAPSHOT";     break;
1289       case SQLITE_LOCKED:             zName = "SQLITE_LOCKED";            break;
1290       case SQLITE_LOCKED_SHAREDCACHE: zName = "SQLITE_LOCKED_SHAREDCACHE";break;
1291       case SQLITE_NOMEM:              zName = "SQLITE_NOMEM";             break;
1292       case SQLITE_READONLY:           zName = "SQLITE_READONLY";          break;
1293       case SQLITE_READONLY_RECOVERY:  zName = "SQLITE_READONLY_RECOVERY"; break;
1294       case SQLITE_READONLY_CANTLOCK:  zName = "SQLITE_READONLY_CANTLOCK"; break;
1295       case SQLITE_READONLY_ROLLBACK:  zName = "SQLITE_READONLY_ROLLBACK"; break;
1296       case SQLITE_READONLY_DBMOVED:   zName = "SQLITE_READONLY_DBMOVED";  break;
1297       case SQLITE_INTERRUPT:          zName = "SQLITE_INTERRUPT";         break;
1298       case SQLITE_IOERR:              zName = "SQLITE_IOERR";             break;
1299       case SQLITE_IOERR_READ:         zName = "SQLITE_IOERR_READ";        break;
1300       case SQLITE_IOERR_SHORT_READ:   zName = "SQLITE_IOERR_SHORT_READ";  break;
1301       case SQLITE_IOERR_WRITE:        zName = "SQLITE_IOERR_WRITE";       break;
1302       case SQLITE_IOERR_FSYNC:        zName = "SQLITE_IOERR_FSYNC";       break;
1303       case SQLITE_IOERR_DIR_FSYNC:    zName = "SQLITE_IOERR_DIR_FSYNC";   break;
1304       case SQLITE_IOERR_TRUNCATE:     zName = "SQLITE_IOERR_TRUNCATE";    break;
1305       case SQLITE_IOERR_FSTAT:        zName = "SQLITE_IOERR_FSTAT";       break;
1306       case SQLITE_IOERR_UNLOCK:       zName = "SQLITE_IOERR_UNLOCK";      break;
1307       case SQLITE_IOERR_RDLOCK:       zName = "SQLITE_IOERR_RDLOCK";      break;
1308       case SQLITE_IOERR_DELETE:       zName = "SQLITE_IOERR_DELETE";      break;
1309       case SQLITE_IOERR_NOMEM:        zName = "SQLITE_IOERR_NOMEM";       break;
1310       case SQLITE_IOERR_ACCESS:       zName = "SQLITE_IOERR_ACCESS";      break;
1311       case SQLITE_IOERR_CHECKRESERVEDLOCK:
1312                                 zName = "SQLITE_IOERR_CHECKRESERVEDLOCK"; break;
1313       case SQLITE_IOERR_LOCK:         zName = "SQLITE_IOERR_LOCK";        break;
1314       case SQLITE_IOERR_CLOSE:        zName = "SQLITE_IOERR_CLOSE";       break;
1315       case SQLITE_IOERR_DIR_CLOSE:    zName = "SQLITE_IOERR_DIR_CLOSE";   break;
1316       case SQLITE_IOERR_SHMOPEN:      zName = "SQLITE_IOERR_SHMOPEN";     break;
1317       case SQLITE_IOERR_SHMSIZE:      zName = "SQLITE_IOERR_SHMSIZE";     break;
1318       case SQLITE_IOERR_SHMLOCK:      zName = "SQLITE_IOERR_SHMLOCK";     break;
1319       case SQLITE_IOERR_SHMMAP:       zName = "SQLITE_IOERR_SHMMAP";      break;
1320       case SQLITE_IOERR_SEEK:         zName = "SQLITE_IOERR_SEEK";        break;
1321       case SQLITE_IOERR_DELETE_NOENT: zName = "SQLITE_IOERR_DELETE_NOENT";break;
1322       case SQLITE_IOERR_MMAP:         zName = "SQLITE_IOERR_MMAP";        break;
1323       case SQLITE_IOERR_GETTEMPPATH:  zName = "SQLITE_IOERR_GETTEMPPATH"; break;
1324       case SQLITE_IOERR_CONVPATH:     zName = "SQLITE_IOERR_CONVPATH";    break;
1325       case SQLITE_CORRUPT:            zName = "SQLITE_CORRUPT";           break;
1326       case SQLITE_CORRUPT_VTAB:       zName = "SQLITE_CORRUPT_VTAB";      break;
1327       case SQLITE_NOTFOUND:           zName = "SQLITE_NOTFOUND";          break;
1328       case SQLITE_FULL:               zName = "SQLITE_FULL";              break;
1329       case SQLITE_CANTOPEN:           zName = "SQLITE_CANTOPEN";          break;
1330       case SQLITE_CANTOPEN_NOTEMPDIR: zName = "SQLITE_CANTOPEN_NOTEMPDIR";break;
1331       case SQLITE_CANTOPEN_ISDIR:     zName = "SQLITE_CANTOPEN_ISDIR";    break;
1332       case SQLITE_CANTOPEN_FULLPATH:  zName = "SQLITE_CANTOPEN_FULLPATH"; break;
1333       case SQLITE_CANTOPEN_CONVPATH:  zName = "SQLITE_CANTOPEN_CONVPATH"; break;
1334       case SQLITE_PROTOCOL:           zName = "SQLITE_PROTOCOL";          break;
1335       case SQLITE_EMPTY:              zName = "SQLITE_EMPTY";             break;
1336       case SQLITE_SCHEMA:             zName = "SQLITE_SCHEMA";            break;
1337       case SQLITE_TOOBIG:             zName = "SQLITE_TOOBIG";            break;
1338       case SQLITE_CONSTRAINT:         zName = "SQLITE_CONSTRAINT";        break;
1339       case SQLITE_CONSTRAINT_UNIQUE:  zName = "SQLITE_CONSTRAINT_UNIQUE"; break;
1340       case SQLITE_CONSTRAINT_TRIGGER: zName = "SQLITE_CONSTRAINT_TRIGGER";break;
1341       case SQLITE_CONSTRAINT_FOREIGNKEY:
1342                                 zName = "SQLITE_CONSTRAINT_FOREIGNKEY";   break;
1343       case SQLITE_CONSTRAINT_CHECK:   zName = "SQLITE_CONSTRAINT_CHECK";  break;
1344       case SQLITE_CONSTRAINT_PRIMARYKEY:
1345                                 zName = "SQLITE_CONSTRAINT_PRIMARYKEY";   break;
1346       case SQLITE_CONSTRAINT_NOTNULL: zName = "SQLITE_CONSTRAINT_NOTNULL";break;
1347       case SQLITE_CONSTRAINT_COMMITHOOK:
1348                                 zName = "SQLITE_CONSTRAINT_COMMITHOOK";   break;
1349       case SQLITE_CONSTRAINT_VTAB:    zName = "SQLITE_CONSTRAINT_VTAB";   break;
1350       case SQLITE_CONSTRAINT_FUNCTION:
1351                                 zName = "SQLITE_CONSTRAINT_FUNCTION";     break;
1352       case SQLITE_CONSTRAINT_ROWID:   zName = "SQLITE_CONSTRAINT_ROWID";  break;
1353       case SQLITE_MISMATCH:           zName = "SQLITE_MISMATCH";          break;
1354       case SQLITE_MISUSE:             zName = "SQLITE_MISUSE";            break;
1355       case SQLITE_NOLFS:              zName = "SQLITE_NOLFS";             break;
1356       case SQLITE_AUTH:               zName = "SQLITE_AUTH";              break;
1357       case SQLITE_FORMAT:             zName = "SQLITE_FORMAT";            break;
1358       case SQLITE_RANGE:              zName = "SQLITE_RANGE";             break;
1359       case SQLITE_NOTADB:             zName = "SQLITE_NOTADB";            break;
1360       case SQLITE_ROW:                zName = "SQLITE_ROW";               break;
1361       case SQLITE_NOTICE:             zName = "SQLITE_NOTICE";            break;
1362       case SQLITE_NOTICE_RECOVER_WAL: zName = "SQLITE_NOTICE_RECOVER_WAL";break;
1363       case SQLITE_NOTICE_RECOVER_ROLLBACK:
1364                                 zName = "SQLITE_NOTICE_RECOVER_ROLLBACK"; break;
1365       case SQLITE_WARNING:            zName = "SQLITE_WARNING";           break;
1366       case SQLITE_WARNING_AUTOINDEX:  zName = "SQLITE_WARNING_AUTOINDEX"; break;
1367       case SQLITE_DONE:               zName = "SQLITE_DONE";              break;
1368     }
1369   }
1370   if( zName==0 ){
1371     static char zBuf[50];
1372     sqlite3_snprintf(sizeof(zBuf), zBuf, "SQLITE_UNKNOWN(%d)", origRc);
1373     zName = zBuf;
1374   }
1375   return zName;
1376 }
1377 #endif
1378 
1379 /*
1380 ** Return a static string that describes the kind of error specified in the
1381 ** argument.
1382 */
1383 const char *sqlite3ErrStr(int rc){
1384   static const char* const aMsg[] = {
1385     /* SQLITE_OK          */ "not an error",
1386     /* SQLITE_ERROR       */ "SQL logic error or missing database",
1387     /* SQLITE_INTERNAL    */ 0,
1388     /* SQLITE_PERM        */ "access permission denied",
1389     /* SQLITE_ABORT       */ "callback requested query abort",
1390     /* SQLITE_BUSY        */ "database is locked",
1391     /* SQLITE_LOCKED      */ "database table is locked",
1392     /* SQLITE_NOMEM       */ "out of memory",
1393     /* SQLITE_READONLY    */ "attempt to write a readonly database",
1394     /* SQLITE_INTERRUPT   */ "interrupted",
1395     /* SQLITE_IOERR       */ "disk I/O error",
1396     /* SQLITE_CORRUPT     */ "database disk image is malformed",
1397     /* SQLITE_NOTFOUND    */ "unknown operation",
1398     /* SQLITE_FULL        */ "database or disk is full",
1399     /* SQLITE_CANTOPEN    */ "unable to open database file",
1400     /* SQLITE_PROTOCOL    */ "locking protocol",
1401     /* SQLITE_EMPTY       */ "table contains no data",
1402     /* SQLITE_SCHEMA      */ "database schema has changed",
1403     /* SQLITE_TOOBIG      */ "string or blob too big",
1404     /* SQLITE_CONSTRAINT  */ "constraint failed",
1405     /* SQLITE_MISMATCH    */ "datatype mismatch",
1406     /* SQLITE_MISUSE      */ "library routine called out of sequence",
1407     /* SQLITE_NOLFS       */ "large file support is disabled",
1408     /* SQLITE_AUTH        */ "authorization denied",
1409     /* SQLITE_FORMAT      */ "auxiliary database format error",
1410     /* SQLITE_RANGE       */ "bind or column index out of range",
1411     /* SQLITE_NOTADB      */ "file is encrypted or is not a database",
1412   };
1413   const char *zErr = "unknown error";
1414   switch( rc ){
1415     case SQLITE_ABORT_ROLLBACK: {
1416       zErr = "abort due to ROLLBACK";
1417       break;
1418     }
1419     default: {
1420       rc &= 0xff;
1421       if( ALWAYS(rc>=0) && rc<ArraySize(aMsg) && aMsg[rc]!=0 ){
1422         zErr = aMsg[rc];
1423       }
1424       break;
1425     }
1426   }
1427   return zErr;
1428 }
1429 
1430 /*
1431 ** This routine implements a busy callback that sleeps and tries
1432 ** again until a timeout value is reached.  The timeout value is
1433 ** an integer number of milliseconds passed in as the first
1434 ** argument.
1435 */
1436 static int sqliteDefaultBusyCallback(
1437  void *ptr,               /* Database connection */
1438  int count                /* Number of times table has been busy */
1439 ){
1440 #if SQLITE_OS_WIN || HAVE_USLEEP
1441   static const u8 delays[] =
1442      { 1, 2, 5, 10, 15, 20, 25, 25,  25,  50,  50, 100 };
1443   static const u8 totals[] =
1444      { 0, 1, 3,  8, 18, 33, 53, 78, 103, 128, 178, 228 };
1445 # define NDELAY ArraySize(delays)
1446   sqlite3 *db = (sqlite3 *)ptr;
1447   int timeout = db->busyTimeout;
1448   int delay, prior;
1449 
1450   assert( count>=0 );
1451   if( count < NDELAY ){
1452     delay = delays[count];
1453     prior = totals[count];
1454   }else{
1455     delay = delays[NDELAY-1];
1456     prior = totals[NDELAY-1] + delay*(count-(NDELAY-1));
1457   }
1458   if( prior + delay > timeout ){
1459     delay = timeout - prior;
1460     if( delay<=0 ) return 0;
1461   }
1462   sqlite3OsSleep(db->pVfs, delay*1000);
1463   return 1;
1464 #else
1465   sqlite3 *db = (sqlite3 *)ptr;
1466   int timeout = ((sqlite3 *)ptr)->busyTimeout;
1467   if( (count+1)*1000 > timeout ){
1468     return 0;
1469   }
1470   sqlite3OsSleep(db->pVfs, 1000000);
1471   return 1;
1472 #endif
1473 }
1474 
1475 /*
1476 ** Invoke the given busy handler.
1477 **
1478 ** This routine is called when an operation failed with a lock.
1479 ** If this routine returns non-zero, the lock is retried.  If it
1480 ** returns 0, the operation aborts with an SQLITE_BUSY error.
1481 */
1482 int sqlite3InvokeBusyHandler(BusyHandler *p){
1483   int rc;
1484   if( NEVER(p==0) || p->xFunc==0 || p->nBusy<0 ) return 0;
1485   rc = p->xFunc(p->pArg, p->nBusy);
1486   if( rc==0 ){
1487     p->nBusy = -1;
1488   }else{
1489     p->nBusy++;
1490   }
1491   return rc;
1492 }
1493 
1494 /*
1495 ** This routine sets the busy callback for an Sqlite database to the
1496 ** given callback function with the given argument.
1497 */
1498 int sqlite3_busy_handler(
1499   sqlite3 *db,
1500   int (*xBusy)(void*,int),
1501   void *pArg
1502 ){
1503 #ifdef SQLITE_ENABLE_API_ARMOR
1504   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
1505 #endif
1506   sqlite3_mutex_enter(db->mutex);
1507   db->busyHandler.xFunc = xBusy;
1508   db->busyHandler.pArg = pArg;
1509   db->busyHandler.nBusy = 0;
1510   db->busyTimeout = 0;
1511   sqlite3_mutex_leave(db->mutex);
1512   return SQLITE_OK;
1513 }
1514 
1515 #ifndef SQLITE_OMIT_PROGRESS_CALLBACK
1516 /*
1517 ** This routine sets the progress callback for an Sqlite database to the
1518 ** given callback function with the given argument. The progress callback will
1519 ** be invoked every nOps opcodes.
1520 */
1521 void sqlite3_progress_handler(
1522   sqlite3 *db,
1523   int nOps,
1524   int (*xProgress)(void*),
1525   void *pArg
1526 ){
1527 #ifdef SQLITE_ENABLE_API_ARMOR
1528   if( !sqlite3SafetyCheckOk(db) ){
1529     (void)SQLITE_MISUSE_BKPT;
1530     return;
1531   }
1532 #endif
1533   sqlite3_mutex_enter(db->mutex);
1534   if( nOps>0 ){
1535     db->xProgress = xProgress;
1536     db->nProgressOps = (unsigned)nOps;
1537     db->pProgressArg = pArg;
1538   }else{
1539     db->xProgress = 0;
1540     db->nProgressOps = 0;
1541     db->pProgressArg = 0;
1542   }
1543   sqlite3_mutex_leave(db->mutex);
1544 }
1545 #endif
1546 
1547 
1548 /*
1549 ** This routine installs a default busy handler that waits for the
1550 ** specified number of milliseconds before returning 0.
1551 */
1552 int sqlite3_busy_timeout(sqlite3 *db, int ms){
1553 #ifdef SQLITE_ENABLE_API_ARMOR
1554   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
1555 #endif
1556   if( ms>0 ){
1557     sqlite3_busy_handler(db, sqliteDefaultBusyCallback, (void*)db);
1558     db->busyTimeout = ms;
1559   }else{
1560     sqlite3_busy_handler(db, 0, 0);
1561   }
1562   return SQLITE_OK;
1563 }
1564 
1565 /*
1566 ** Cause any pending operation to stop at its earliest opportunity.
1567 */
1568 void sqlite3_interrupt(sqlite3 *db){
1569 #ifdef SQLITE_ENABLE_API_ARMOR
1570   if( !sqlite3SafetyCheckOk(db) ){
1571     (void)SQLITE_MISUSE_BKPT;
1572     return;
1573   }
1574 #endif
1575   db->u1.isInterrupted = 1;
1576 }
1577 
1578 
1579 /*
1580 ** This function is exactly the same as sqlite3_create_function(), except
1581 ** that it is designed to be called by internal code. The difference is
1582 ** that if a malloc() fails in sqlite3_create_function(), an error code
1583 ** is returned and the mallocFailed flag cleared.
1584 */
1585 int sqlite3CreateFunc(
1586   sqlite3 *db,
1587   const char *zFunctionName,
1588   int nArg,
1589   int enc,
1590   void *pUserData,
1591   void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
1592   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
1593   void (*xFinal)(sqlite3_context*),
1594   FuncDestructor *pDestructor
1595 ){
1596   FuncDef *p;
1597   int nName;
1598   int extraFlags;
1599 
1600   assert( sqlite3_mutex_held(db->mutex) );
1601   if( zFunctionName==0 ||
1602       (xSFunc && (xFinal || xStep)) ||
1603       (!xSFunc && (xFinal && !xStep)) ||
1604       (!xSFunc && (!xFinal && xStep)) ||
1605       (nArg<-1 || nArg>SQLITE_MAX_FUNCTION_ARG) ||
1606       (255<(nName = sqlite3Strlen30( zFunctionName))) ){
1607     return SQLITE_MISUSE_BKPT;
1608   }
1609 
1610   assert( SQLITE_FUNC_CONSTANT==SQLITE_DETERMINISTIC );
1611   extraFlags = enc &  SQLITE_DETERMINISTIC;
1612   enc &= (SQLITE_FUNC_ENCMASK|SQLITE_ANY);
1613 
1614 #ifndef SQLITE_OMIT_UTF16
1615   /* If SQLITE_UTF16 is specified as the encoding type, transform this
1616   ** to one of SQLITE_UTF16LE or SQLITE_UTF16BE using the
1617   ** SQLITE_UTF16NATIVE macro. SQLITE_UTF16 is not used internally.
1618   **
1619   ** If SQLITE_ANY is specified, add three versions of the function
1620   ** to the hash table.
1621   */
1622   if( enc==SQLITE_UTF16 ){
1623     enc = SQLITE_UTF16NATIVE;
1624   }else if( enc==SQLITE_ANY ){
1625     int rc;
1626     rc = sqlite3CreateFunc(db, zFunctionName, nArg, SQLITE_UTF8|extraFlags,
1627          pUserData, xSFunc, xStep, xFinal, pDestructor);
1628     if( rc==SQLITE_OK ){
1629       rc = sqlite3CreateFunc(db, zFunctionName, nArg, SQLITE_UTF16LE|extraFlags,
1630           pUserData, xSFunc, xStep, xFinal, pDestructor);
1631     }
1632     if( rc!=SQLITE_OK ){
1633       return rc;
1634     }
1635     enc = SQLITE_UTF16BE;
1636   }
1637 #else
1638   enc = SQLITE_UTF8;
1639 #endif
1640 
1641   /* Check if an existing function is being overridden or deleted. If so,
1642   ** and there are active VMs, then return SQLITE_BUSY. If a function
1643   ** is being overridden/deleted but there are no active VMs, allow the
1644   ** operation to continue but invalidate all precompiled statements.
1645   */
1646   p = sqlite3FindFunction(db, zFunctionName, nArg, (u8)enc, 0);
1647   if( p && (p->funcFlags & SQLITE_FUNC_ENCMASK)==enc && p->nArg==nArg ){
1648     if( db->nVdbeActive ){
1649       sqlite3ErrorWithMsg(db, SQLITE_BUSY,
1650         "unable to delete/modify user-function due to active statements");
1651       assert( !db->mallocFailed );
1652       return SQLITE_BUSY;
1653     }else{
1654       sqlite3ExpirePreparedStatements(db);
1655     }
1656   }
1657 
1658   p = sqlite3FindFunction(db, zFunctionName, nArg, (u8)enc, 1);
1659   assert(p || db->mallocFailed);
1660   if( !p ){
1661     return SQLITE_NOMEM_BKPT;
1662   }
1663 
1664   /* If an older version of the function with a configured destructor is
1665   ** being replaced invoke the destructor function here. */
1666   functionDestroy(db, p);
1667 
1668   if( pDestructor ){
1669     pDestructor->nRef++;
1670   }
1671   p->u.pDestructor = pDestructor;
1672   p->funcFlags = (p->funcFlags & SQLITE_FUNC_ENCMASK) | extraFlags;
1673   testcase( p->funcFlags & SQLITE_DETERMINISTIC );
1674   p->xSFunc = xSFunc ? xSFunc : xStep;
1675   p->xFinalize = xFinal;
1676   p->pUserData = pUserData;
1677   p->nArg = (u16)nArg;
1678   return SQLITE_OK;
1679 }
1680 
1681 /*
1682 ** Create new user functions.
1683 */
1684 int sqlite3_create_function(
1685   sqlite3 *db,
1686   const char *zFunc,
1687   int nArg,
1688   int enc,
1689   void *p,
1690   void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
1691   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
1692   void (*xFinal)(sqlite3_context*)
1693 ){
1694   return sqlite3_create_function_v2(db, zFunc, nArg, enc, p, xSFunc, xStep,
1695                                     xFinal, 0);
1696 }
1697 
1698 int sqlite3_create_function_v2(
1699   sqlite3 *db,
1700   const char *zFunc,
1701   int nArg,
1702   int enc,
1703   void *p,
1704   void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
1705   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
1706   void (*xFinal)(sqlite3_context*),
1707   void (*xDestroy)(void *)
1708 ){
1709   int rc = SQLITE_ERROR;
1710   FuncDestructor *pArg = 0;
1711 
1712 #ifdef SQLITE_ENABLE_API_ARMOR
1713   if( !sqlite3SafetyCheckOk(db) ){
1714     return SQLITE_MISUSE_BKPT;
1715   }
1716 #endif
1717   sqlite3_mutex_enter(db->mutex);
1718   if( xDestroy ){
1719     pArg = (FuncDestructor *)sqlite3DbMallocZero(db, sizeof(FuncDestructor));
1720     if( !pArg ){
1721       xDestroy(p);
1722       goto out;
1723     }
1724     pArg->xDestroy = xDestroy;
1725     pArg->pUserData = p;
1726   }
1727   rc = sqlite3CreateFunc(db, zFunc, nArg, enc, p, xSFunc, xStep, xFinal, pArg);
1728   if( pArg && pArg->nRef==0 ){
1729     assert( rc!=SQLITE_OK );
1730     xDestroy(p);
1731     sqlite3DbFree(db, pArg);
1732   }
1733 
1734  out:
1735   rc = sqlite3ApiExit(db, rc);
1736   sqlite3_mutex_leave(db->mutex);
1737   return rc;
1738 }
1739 
1740 #ifndef SQLITE_OMIT_UTF16
1741 int sqlite3_create_function16(
1742   sqlite3 *db,
1743   const void *zFunctionName,
1744   int nArg,
1745   int eTextRep,
1746   void *p,
1747   void (*xSFunc)(sqlite3_context*,int,sqlite3_value**),
1748   void (*xStep)(sqlite3_context*,int,sqlite3_value**),
1749   void (*xFinal)(sqlite3_context*)
1750 ){
1751   int rc;
1752   char *zFunc8;
1753 
1754 #ifdef SQLITE_ENABLE_API_ARMOR
1755   if( !sqlite3SafetyCheckOk(db) || zFunctionName==0 ) return SQLITE_MISUSE_BKPT;
1756 #endif
1757   sqlite3_mutex_enter(db->mutex);
1758   assert( !db->mallocFailed );
1759   zFunc8 = sqlite3Utf16to8(db, zFunctionName, -1, SQLITE_UTF16NATIVE);
1760   rc = sqlite3CreateFunc(db, zFunc8, nArg, eTextRep, p, xSFunc,xStep,xFinal,0);
1761   sqlite3DbFree(db, zFunc8);
1762   rc = sqlite3ApiExit(db, rc);
1763   sqlite3_mutex_leave(db->mutex);
1764   return rc;
1765 }
1766 #endif
1767 
1768 
1769 /*
1770 ** Declare that a function has been overloaded by a virtual table.
1771 **
1772 ** If the function already exists as a regular global function, then
1773 ** this routine is a no-op.  If the function does not exist, then create
1774 ** a new one that always throws a run-time error.
1775 **
1776 ** When virtual tables intend to provide an overloaded function, they
1777 ** should call this routine to make sure the global function exists.
1778 ** A global function must exist in order for name resolution to work
1779 ** properly.
1780 */
1781 int sqlite3_overload_function(
1782   sqlite3 *db,
1783   const char *zName,
1784   int nArg
1785 ){
1786   int rc = SQLITE_OK;
1787 
1788 #ifdef SQLITE_ENABLE_API_ARMOR
1789   if( !sqlite3SafetyCheckOk(db) || zName==0 || nArg<-2 ){
1790     return SQLITE_MISUSE_BKPT;
1791   }
1792 #endif
1793   sqlite3_mutex_enter(db->mutex);
1794   if( sqlite3FindFunction(db, zName, nArg, SQLITE_UTF8, 0)==0 ){
1795     rc = sqlite3CreateFunc(db, zName, nArg, SQLITE_UTF8,
1796                            0, sqlite3InvalidFunction, 0, 0, 0);
1797   }
1798   rc = sqlite3ApiExit(db, rc);
1799   sqlite3_mutex_leave(db->mutex);
1800   return rc;
1801 }
1802 
1803 #ifndef SQLITE_OMIT_TRACE
1804 /*
1805 ** Register a trace function.  The pArg from the previously registered trace
1806 ** is returned.
1807 **
1808 ** A NULL trace function means that no tracing is executes.  A non-NULL
1809 ** trace is a pointer to a function that is invoked at the start of each
1810 ** SQL statement.
1811 */
1812 #ifndef SQLITE_OMIT_DEPRECATED
1813 void *sqlite3_trace(sqlite3 *db, void(*xTrace)(void*,const char*), void *pArg){
1814   void *pOld;
1815 
1816 #ifdef SQLITE_ENABLE_API_ARMOR
1817   if( !sqlite3SafetyCheckOk(db) ){
1818     (void)SQLITE_MISUSE_BKPT;
1819     return 0;
1820   }
1821 #endif
1822   sqlite3_mutex_enter(db->mutex);
1823   pOld = db->pTraceArg;
1824   db->mTrace = xTrace ? SQLITE_TRACE_LEGACY : 0;
1825   db->xTrace = (int(*)(u32,void*,void*,void*))xTrace;
1826   db->pTraceArg = pArg;
1827   sqlite3_mutex_leave(db->mutex);
1828   return pOld;
1829 }
1830 #endif /* SQLITE_OMIT_DEPRECATED */
1831 
1832 /* Register a trace callback using the version-2 interface.
1833 */
1834 int sqlite3_trace_v2(
1835   sqlite3 *db,                               /* Trace this connection */
1836   unsigned mTrace,                           /* Mask of events to be traced */
1837   int(*xTrace)(unsigned,void*,void*,void*),  /* Callback to invoke */
1838   void *pArg                                 /* Context */
1839 ){
1840 #ifdef SQLITE_ENABLE_API_ARMOR
1841   if( !sqlite3SafetyCheckOk(db) ){
1842     return SQLITE_MISUSE_BKPT;
1843   }
1844 #endif
1845   sqlite3_mutex_enter(db->mutex);
1846   if( mTrace==0 ) xTrace = 0;
1847   if( xTrace==0 ) mTrace = 0;
1848   db->mTrace = mTrace;
1849   db->xTrace = xTrace;
1850   db->pTraceArg = pArg;
1851   sqlite3_mutex_leave(db->mutex);
1852   return SQLITE_OK;
1853 }
1854 
1855 #ifndef SQLITE_OMIT_DEPRECATED
1856 /*
1857 ** Register a profile function.  The pArg from the previously registered
1858 ** profile function is returned.
1859 **
1860 ** A NULL profile function means that no profiling is executes.  A non-NULL
1861 ** profile is a pointer to a function that is invoked at the conclusion of
1862 ** each SQL statement that is run.
1863 */
1864 void *sqlite3_profile(
1865   sqlite3 *db,
1866   void (*xProfile)(void*,const char*,sqlite_uint64),
1867   void *pArg
1868 ){
1869   void *pOld;
1870 
1871 #ifdef SQLITE_ENABLE_API_ARMOR
1872   if( !sqlite3SafetyCheckOk(db) ){
1873     (void)SQLITE_MISUSE_BKPT;
1874     return 0;
1875   }
1876 #endif
1877   sqlite3_mutex_enter(db->mutex);
1878   pOld = db->pProfileArg;
1879   db->xProfile = xProfile;
1880   db->pProfileArg = pArg;
1881   sqlite3_mutex_leave(db->mutex);
1882   return pOld;
1883 }
1884 #endif /* SQLITE_OMIT_DEPRECATED */
1885 #endif /* SQLITE_OMIT_TRACE */
1886 
1887 /*
1888 ** Register a function to be invoked when a transaction commits.
1889 ** If the invoked function returns non-zero, then the commit becomes a
1890 ** rollback.
1891 */
1892 void *sqlite3_commit_hook(
1893   sqlite3 *db,              /* Attach the hook to this database */
1894   int (*xCallback)(void*),  /* Function to invoke on each commit */
1895   void *pArg                /* Argument to the function */
1896 ){
1897   void *pOld;
1898 
1899 #ifdef SQLITE_ENABLE_API_ARMOR
1900   if( !sqlite3SafetyCheckOk(db) ){
1901     (void)SQLITE_MISUSE_BKPT;
1902     return 0;
1903   }
1904 #endif
1905   sqlite3_mutex_enter(db->mutex);
1906   pOld = db->pCommitArg;
1907   db->xCommitCallback = xCallback;
1908   db->pCommitArg = pArg;
1909   sqlite3_mutex_leave(db->mutex);
1910   return pOld;
1911 }
1912 
1913 /*
1914 ** Register a callback to be invoked each time a row is updated,
1915 ** inserted or deleted using this database connection.
1916 */
1917 void *sqlite3_update_hook(
1918   sqlite3 *db,              /* Attach the hook to this database */
1919   void (*xCallback)(void*,int,char const *,char const *,sqlite_int64),
1920   void *pArg                /* Argument to the function */
1921 ){
1922   void *pRet;
1923 
1924 #ifdef SQLITE_ENABLE_API_ARMOR
1925   if( !sqlite3SafetyCheckOk(db) ){
1926     (void)SQLITE_MISUSE_BKPT;
1927     return 0;
1928   }
1929 #endif
1930   sqlite3_mutex_enter(db->mutex);
1931   pRet = db->pUpdateArg;
1932   db->xUpdateCallback = xCallback;
1933   db->pUpdateArg = pArg;
1934   sqlite3_mutex_leave(db->mutex);
1935   return pRet;
1936 }
1937 
1938 /*
1939 ** Register a callback to be invoked each time a transaction is rolled
1940 ** back by this database connection.
1941 */
1942 void *sqlite3_rollback_hook(
1943   sqlite3 *db,              /* Attach the hook to this database */
1944   void (*xCallback)(void*), /* Callback function */
1945   void *pArg                /* Argument to the function */
1946 ){
1947   void *pRet;
1948 
1949 #ifdef SQLITE_ENABLE_API_ARMOR
1950   if( !sqlite3SafetyCheckOk(db) ){
1951     (void)SQLITE_MISUSE_BKPT;
1952     return 0;
1953   }
1954 #endif
1955   sqlite3_mutex_enter(db->mutex);
1956   pRet = db->pRollbackArg;
1957   db->xRollbackCallback = xCallback;
1958   db->pRollbackArg = pArg;
1959   sqlite3_mutex_leave(db->mutex);
1960   return pRet;
1961 }
1962 
1963 #ifdef SQLITE_ENABLE_PREUPDATE_HOOK
1964 /*
1965 ** Register a callback to be invoked each time a row is updated,
1966 ** inserted or deleted using this database connection.
1967 */
1968 void *sqlite3_preupdate_hook(
1969   sqlite3 *db,              /* Attach the hook to this database */
1970   void(*xCallback)(         /* Callback function */
1971     void*,sqlite3*,int,char const*,char const*,sqlite3_int64,sqlite3_int64),
1972   void *pArg                /* First callback argument */
1973 ){
1974   void *pRet;
1975   sqlite3_mutex_enter(db->mutex);
1976   pRet = db->pPreUpdateArg;
1977   db->xPreUpdateCallback = xCallback;
1978   db->pPreUpdateArg = pArg;
1979   sqlite3_mutex_leave(db->mutex);
1980   return pRet;
1981 }
1982 #endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
1983 
1984 #ifndef SQLITE_OMIT_WAL
1985 /*
1986 ** The sqlite3_wal_hook() callback registered by sqlite3_wal_autocheckpoint().
1987 ** Invoke sqlite3_wal_checkpoint if the number of frames in the log file
1988 ** is greater than sqlite3.pWalArg cast to an integer (the value configured by
1989 ** wal_autocheckpoint()).
1990 */
1991 int sqlite3WalDefaultHook(
1992   void *pClientData,     /* Argument */
1993   sqlite3 *db,           /* Connection */
1994   const char *zDb,       /* Database */
1995   int nFrame             /* Size of WAL */
1996 ){
1997   if( nFrame>=SQLITE_PTR_TO_INT(pClientData) ){
1998     sqlite3BeginBenignMalloc();
1999     sqlite3_wal_checkpoint(db, zDb);
2000     sqlite3EndBenignMalloc();
2001   }
2002   return SQLITE_OK;
2003 }
2004 #endif /* SQLITE_OMIT_WAL */
2005 
2006 /*
2007 ** Configure an sqlite3_wal_hook() callback to automatically checkpoint
2008 ** a database after committing a transaction if there are nFrame or
2009 ** more frames in the log file. Passing zero or a negative value as the
2010 ** nFrame parameter disables automatic checkpoints entirely.
2011 **
2012 ** The callback registered by this function replaces any existing callback
2013 ** registered using sqlite3_wal_hook(). Likewise, registering a callback
2014 ** using sqlite3_wal_hook() disables the automatic checkpoint mechanism
2015 ** configured by this function.
2016 */
2017 int sqlite3_wal_autocheckpoint(sqlite3 *db, int nFrame){
2018 #ifdef SQLITE_OMIT_WAL
2019   UNUSED_PARAMETER(db);
2020   UNUSED_PARAMETER(nFrame);
2021 #else
2022 #ifdef SQLITE_ENABLE_API_ARMOR
2023   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
2024 #endif
2025   if( nFrame>0 ){
2026     sqlite3_wal_hook(db, sqlite3WalDefaultHook, SQLITE_INT_TO_PTR(nFrame));
2027   }else{
2028     sqlite3_wal_hook(db, 0, 0);
2029   }
2030 #endif
2031   return SQLITE_OK;
2032 }
2033 
2034 /*
2035 ** Register a callback to be invoked each time a transaction is written
2036 ** into the write-ahead-log by this database connection.
2037 */
2038 void *sqlite3_wal_hook(
2039   sqlite3 *db,                    /* Attach the hook to this db handle */
2040   int(*xCallback)(void *, sqlite3*, const char*, int),
2041   void *pArg                      /* First argument passed to xCallback() */
2042 ){
2043 #ifndef SQLITE_OMIT_WAL
2044   void *pRet;
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   pRet = db->pWalArg;
2053   db->xWalCallback = xCallback;
2054   db->pWalArg = pArg;
2055   sqlite3_mutex_leave(db->mutex);
2056   return pRet;
2057 #else
2058   return 0;
2059 #endif
2060 }
2061 
2062 /*
2063 ** Checkpoint database zDb.
2064 */
2065 int sqlite3_wal_checkpoint_v2(
2066   sqlite3 *db,                    /* Database handle */
2067   const char *zDb,                /* Name of attached database (or NULL) */
2068   int eMode,                      /* SQLITE_CHECKPOINT_* value */
2069   int *pnLog,                     /* OUT: Size of WAL log in frames */
2070   int *pnCkpt                     /* OUT: Total number of frames checkpointed */
2071 ){
2072 #ifdef SQLITE_OMIT_WAL
2073   return SQLITE_OK;
2074 #else
2075   int rc;                         /* Return code */
2076   int iDb = SQLITE_MAX_ATTACHED;  /* sqlite3.aDb[] index of db to checkpoint */
2077 
2078 #ifdef SQLITE_ENABLE_API_ARMOR
2079   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
2080 #endif
2081 
2082   /* Initialize the output variables to -1 in case an error occurs. */
2083   if( pnLog ) *pnLog = -1;
2084   if( pnCkpt ) *pnCkpt = -1;
2085 
2086   assert( SQLITE_CHECKPOINT_PASSIVE==0 );
2087   assert( SQLITE_CHECKPOINT_FULL==1 );
2088   assert( SQLITE_CHECKPOINT_RESTART==2 );
2089   assert( SQLITE_CHECKPOINT_TRUNCATE==3 );
2090   if( eMode<SQLITE_CHECKPOINT_PASSIVE || eMode>SQLITE_CHECKPOINT_TRUNCATE ){
2091     /* EVIDENCE-OF: R-03996-12088 The M parameter must be a valid checkpoint
2092     ** mode: */
2093     return SQLITE_MISUSE;
2094   }
2095 
2096   sqlite3_mutex_enter(db->mutex);
2097   if( zDb && zDb[0] ){
2098     iDb = sqlite3FindDbName(db, zDb);
2099   }
2100   if( iDb<0 ){
2101     rc = SQLITE_ERROR;
2102     sqlite3ErrorWithMsg(db, SQLITE_ERROR, "unknown database: %s", zDb);
2103   }else{
2104     db->busyHandler.nBusy = 0;
2105     rc = sqlite3Checkpoint(db, iDb, eMode, pnLog, pnCkpt);
2106     sqlite3Error(db, rc);
2107   }
2108   rc = sqlite3ApiExit(db, rc);
2109 
2110   /* If there are no active statements, clear the interrupt flag at this
2111   ** point.  */
2112   if( db->nVdbeActive==0 ){
2113     db->u1.isInterrupted = 0;
2114   }
2115 
2116   sqlite3_mutex_leave(db->mutex);
2117   return rc;
2118 #endif
2119 }
2120 
2121 
2122 /*
2123 ** Checkpoint database zDb. If zDb is NULL, or if the buffer zDb points
2124 ** to contains a zero-length string, all attached databases are
2125 ** checkpointed.
2126 */
2127 int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb){
2128   /* EVIDENCE-OF: R-41613-20553 The sqlite3_wal_checkpoint(D,X) is equivalent to
2129   ** sqlite3_wal_checkpoint_v2(D,X,SQLITE_CHECKPOINT_PASSIVE,0,0). */
2130   return sqlite3_wal_checkpoint_v2(db,zDb,SQLITE_CHECKPOINT_PASSIVE,0,0);
2131 }
2132 
2133 #ifndef SQLITE_OMIT_WAL
2134 /*
2135 ** Run a checkpoint on database iDb. This is a no-op if database iDb is
2136 ** not currently open in WAL mode.
2137 **
2138 ** If a transaction is open on the database being checkpointed, this
2139 ** function returns SQLITE_LOCKED and a checkpoint is not attempted. If
2140 ** an error occurs while running the checkpoint, an SQLite error code is
2141 ** returned (i.e. SQLITE_IOERR). Otherwise, SQLITE_OK.
2142 **
2143 ** The mutex on database handle db should be held by the caller. The mutex
2144 ** associated with the specific b-tree being checkpointed is taken by
2145 ** this function while the checkpoint is running.
2146 **
2147 ** If iDb is passed SQLITE_MAX_ATTACHED, then all attached databases are
2148 ** checkpointed. If an error is encountered it is returned immediately -
2149 ** no attempt is made to checkpoint any remaining databases.
2150 **
2151 ** Parameter eMode is one of SQLITE_CHECKPOINT_PASSIVE, FULL or RESTART.
2152 */
2153 int sqlite3Checkpoint(sqlite3 *db, int iDb, int eMode, int *pnLog, int *pnCkpt){
2154   int rc = SQLITE_OK;             /* Return code */
2155   int i;                          /* Used to iterate through attached dbs */
2156   int bBusy = 0;                  /* True if SQLITE_BUSY has been encountered */
2157 
2158   assert( sqlite3_mutex_held(db->mutex) );
2159   assert( !pnLog || *pnLog==-1 );
2160   assert( !pnCkpt || *pnCkpt==-1 );
2161 
2162   for(i=0; i<db->nDb && rc==SQLITE_OK; i++){
2163     if( i==iDb || iDb==SQLITE_MAX_ATTACHED ){
2164       rc = sqlite3BtreeCheckpoint(db->aDb[i].pBt, eMode, pnLog, pnCkpt);
2165       pnLog = 0;
2166       pnCkpt = 0;
2167       if( rc==SQLITE_BUSY ){
2168         bBusy = 1;
2169         rc = SQLITE_OK;
2170       }
2171     }
2172   }
2173 
2174   return (rc==SQLITE_OK && bBusy) ? SQLITE_BUSY : rc;
2175 }
2176 #endif /* SQLITE_OMIT_WAL */
2177 
2178 /*
2179 ** This function returns true if main-memory should be used instead of
2180 ** a temporary file for transient pager files and statement journals.
2181 ** The value returned depends on the value of db->temp_store (runtime
2182 ** parameter) and the compile time value of SQLITE_TEMP_STORE. The
2183 ** following table describes the relationship between these two values
2184 ** and this functions return value.
2185 **
2186 **   SQLITE_TEMP_STORE     db->temp_store     Location of temporary database
2187 **   -----------------     --------------     ------------------------------
2188 **   0                     any                file      (return 0)
2189 **   1                     1                  file      (return 0)
2190 **   1                     2                  memory    (return 1)
2191 **   1                     0                  file      (return 0)
2192 **   2                     1                  file      (return 0)
2193 **   2                     2                  memory    (return 1)
2194 **   2                     0                  memory    (return 1)
2195 **   3                     any                memory    (return 1)
2196 */
2197 int sqlite3TempInMemory(const sqlite3 *db){
2198 #if SQLITE_TEMP_STORE==1
2199   return ( db->temp_store==2 );
2200 #endif
2201 #if SQLITE_TEMP_STORE==2
2202   return ( db->temp_store!=1 );
2203 #endif
2204 #if SQLITE_TEMP_STORE==3
2205   UNUSED_PARAMETER(db);
2206   return 1;
2207 #endif
2208 #if SQLITE_TEMP_STORE<1 || SQLITE_TEMP_STORE>3
2209   UNUSED_PARAMETER(db);
2210   return 0;
2211 #endif
2212 }
2213 
2214 /*
2215 ** Return UTF-8 encoded English language explanation of the most recent
2216 ** error.
2217 */
2218 const char *sqlite3_errmsg(sqlite3 *db){
2219   const char *z;
2220   if( !db ){
2221     return sqlite3ErrStr(SQLITE_NOMEM_BKPT);
2222   }
2223   if( !sqlite3SafetyCheckSickOrOk(db) ){
2224     return sqlite3ErrStr(SQLITE_MISUSE_BKPT);
2225   }
2226   sqlite3_mutex_enter(db->mutex);
2227   if( db->mallocFailed ){
2228     z = sqlite3ErrStr(SQLITE_NOMEM_BKPT);
2229   }else{
2230     testcase( db->pErr==0 );
2231     z = (char*)sqlite3_value_text(db->pErr);
2232     assert( !db->mallocFailed );
2233     if( z==0 ){
2234       z = sqlite3ErrStr(db->errCode);
2235     }
2236   }
2237   sqlite3_mutex_leave(db->mutex);
2238   return z;
2239 }
2240 
2241 #ifndef SQLITE_OMIT_UTF16
2242 /*
2243 ** Return UTF-16 encoded English language explanation of the most recent
2244 ** error.
2245 */
2246 const void *sqlite3_errmsg16(sqlite3 *db){
2247   static const u16 outOfMem[] = {
2248     'o', 'u', 't', ' ', 'o', 'f', ' ', 'm', 'e', 'm', 'o', 'r', 'y', 0
2249   };
2250   static const u16 misuse[] = {
2251     'l', 'i', 'b', 'r', 'a', 'r', 'y', ' ',
2252     'r', 'o', 'u', 't', 'i', 'n', 'e', ' ',
2253     'c', 'a', 'l', 'l', 'e', 'd', ' ',
2254     'o', 'u', 't', ' ',
2255     'o', 'f', ' ',
2256     's', 'e', 'q', 'u', 'e', 'n', 'c', 'e', 0
2257   };
2258 
2259   const void *z;
2260   if( !db ){
2261     return (void *)outOfMem;
2262   }
2263   if( !sqlite3SafetyCheckSickOrOk(db) ){
2264     return (void *)misuse;
2265   }
2266   sqlite3_mutex_enter(db->mutex);
2267   if( db->mallocFailed ){
2268     z = (void *)outOfMem;
2269   }else{
2270     z = sqlite3_value_text16(db->pErr);
2271     if( z==0 ){
2272       sqlite3ErrorWithMsg(db, db->errCode, sqlite3ErrStr(db->errCode));
2273       z = sqlite3_value_text16(db->pErr);
2274     }
2275     /* A malloc() may have failed within the call to sqlite3_value_text16()
2276     ** above. If this is the case, then the db->mallocFailed flag needs to
2277     ** be cleared before returning. Do this directly, instead of via
2278     ** sqlite3ApiExit(), to avoid setting the database handle error message.
2279     */
2280     sqlite3OomClear(db);
2281   }
2282   sqlite3_mutex_leave(db->mutex);
2283   return z;
2284 }
2285 #endif /* SQLITE_OMIT_UTF16 */
2286 
2287 /*
2288 ** Return the most recent error code generated by an SQLite routine. If NULL is
2289 ** passed to this function, we assume a malloc() failed during sqlite3_open().
2290 */
2291 int sqlite3_errcode(sqlite3 *db){
2292   if( db && !sqlite3SafetyCheckSickOrOk(db) ){
2293     return SQLITE_MISUSE_BKPT;
2294   }
2295   if( !db || db->mallocFailed ){
2296     return SQLITE_NOMEM_BKPT;
2297   }
2298   return db->errCode & db->errMask;
2299 }
2300 int sqlite3_extended_errcode(sqlite3 *db){
2301   if( db && !sqlite3SafetyCheckSickOrOk(db) ){
2302     return SQLITE_MISUSE_BKPT;
2303   }
2304   if( !db || db->mallocFailed ){
2305     return SQLITE_NOMEM_BKPT;
2306   }
2307   return db->errCode;
2308 }
2309 int sqlite3_system_errno(sqlite3 *db){
2310   return db ? db->iSysErrno : 0;
2311 }
2312 
2313 /*
2314 ** Return a string that describes the kind of error specified in the
2315 ** argument.  For now, this simply calls the internal sqlite3ErrStr()
2316 ** function.
2317 */
2318 const char *sqlite3_errstr(int rc){
2319   return sqlite3ErrStr(rc);
2320 }
2321 
2322 /*
2323 ** Create a new collating function for database "db".  The name is zName
2324 ** and the encoding is enc.
2325 */
2326 static int createCollation(
2327   sqlite3* db,
2328   const char *zName,
2329   u8 enc,
2330   void* pCtx,
2331   int(*xCompare)(void*,int,const void*,int,const void*),
2332   void(*xDel)(void*)
2333 ){
2334   CollSeq *pColl;
2335   int enc2;
2336 
2337   assert( sqlite3_mutex_held(db->mutex) );
2338 
2339   /* If SQLITE_UTF16 is specified as the encoding type, transform this
2340   ** to one of SQLITE_UTF16LE or SQLITE_UTF16BE using the
2341   ** SQLITE_UTF16NATIVE macro. SQLITE_UTF16 is not used internally.
2342   */
2343   enc2 = enc;
2344   testcase( enc2==SQLITE_UTF16 );
2345   testcase( enc2==SQLITE_UTF16_ALIGNED );
2346   if( enc2==SQLITE_UTF16 || enc2==SQLITE_UTF16_ALIGNED ){
2347     enc2 = SQLITE_UTF16NATIVE;
2348   }
2349   if( enc2<SQLITE_UTF8 || enc2>SQLITE_UTF16BE ){
2350     return SQLITE_MISUSE_BKPT;
2351   }
2352 
2353   /* Check if this call is removing or replacing an existing collation
2354   ** sequence. If so, and there are active VMs, return busy. If there
2355   ** are no active VMs, invalidate any pre-compiled statements.
2356   */
2357   pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, 0);
2358   if( pColl && pColl->xCmp ){
2359     if( db->nVdbeActive ){
2360       sqlite3ErrorWithMsg(db, SQLITE_BUSY,
2361         "unable to delete/modify collation sequence due to active statements");
2362       return SQLITE_BUSY;
2363     }
2364     sqlite3ExpirePreparedStatements(db);
2365 
2366     /* If collation sequence pColl was created directly by a call to
2367     ** sqlite3_create_collation, and not generated by synthCollSeq(),
2368     ** then any copies made by synthCollSeq() need to be invalidated.
2369     ** Also, collation destructor - CollSeq.xDel() - function may need
2370     ** to be called.
2371     */
2372     if( (pColl->enc & ~SQLITE_UTF16_ALIGNED)==enc2 ){
2373       CollSeq *aColl = sqlite3HashFind(&db->aCollSeq, zName);
2374       int j;
2375       for(j=0; j<3; j++){
2376         CollSeq *p = &aColl[j];
2377         if( p->enc==pColl->enc ){
2378           if( p->xDel ){
2379             p->xDel(p->pUser);
2380           }
2381           p->xCmp = 0;
2382         }
2383       }
2384     }
2385   }
2386 
2387   pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, 1);
2388   if( pColl==0 ) return SQLITE_NOMEM_BKPT;
2389   pColl->xCmp = xCompare;
2390   pColl->pUser = pCtx;
2391   pColl->xDel = xDel;
2392   pColl->enc = (u8)(enc2 | (enc & SQLITE_UTF16_ALIGNED));
2393   sqlite3Error(db, SQLITE_OK);
2394   return SQLITE_OK;
2395 }
2396 
2397 
2398 /*
2399 ** This array defines hard upper bounds on limit values.  The
2400 ** initializer must be kept in sync with the SQLITE_LIMIT_*
2401 ** #defines in sqlite3.h.
2402 */
2403 static const int aHardLimit[] = {
2404   SQLITE_MAX_LENGTH,
2405   SQLITE_MAX_SQL_LENGTH,
2406   SQLITE_MAX_COLUMN,
2407   SQLITE_MAX_EXPR_DEPTH,
2408   SQLITE_MAX_COMPOUND_SELECT,
2409   SQLITE_MAX_VDBE_OP,
2410   SQLITE_MAX_FUNCTION_ARG,
2411   SQLITE_MAX_ATTACHED,
2412   SQLITE_MAX_LIKE_PATTERN_LENGTH,
2413   SQLITE_MAX_VARIABLE_NUMBER,      /* IMP: R-38091-32352 */
2414   SQLITE_MAX_TRIGGER_DEPTH,
2415   SQLITE_MAX_WORKER_THREADS,
2416 };
2417 
2418 /*
2419 ** Make sure the hard limits are set to reasonable values
2420 */
2421 #if SQLITE_MAX_LENGTH<100
2422 # error SQLITE_MAX_LENGTH must be at least 100
2423 #endif
2424 #if SQLITE_MAX_SQL_LENGTH<100
2425 # error SQLITE_MAX_SQL_LENGTH must be at least 100
2426 #endif
2427 #if SQLITE_MAX_SQL_LENGTH>SQLITE_MAX_LENGTH
2428 # error SQLITE_MAX_SQL_LENGTH must not be greater than SQLITE_MAX_LENGTH
2429 #endif
2430 #if SQLITE_MAX_COMPOUND_SELECT<2
2431 # error SQLITE_MAX_COMPOUND_SELECT must be at least 2
2432 #endif
2433 #if SQLITE_MAX_VDBE_OP<40
2434 # error SQLITE_MAX_VDBE_OP must be at least 40
2435 #endif
2436 #if SQLITE_MAX_FUNCTION_ARG<0 || SQLITE_MAX_FUNCTION_ARG>127
2437 # error SQLITE_MAX_FUNCTION_ARG must be between 0 and 127
2438 #endif
2439 #if SQLITE_MAX_ATTACHED<0 || SQLITE_MAX_ATTACHED>125
2440 # error SQLITE_MAX_ATTACHED must be between 0 and 125
2441 #endif
2442 #if SQLITE_MAX_LIKE_PATTERN_LENGTH<1
2443 # error SQLITE_MAX_LIKE_PATTERN_LENGTH must be at least 1
2444 #endif
2445 #if SQLITE_MAX_COLUMN>32767
2446 # error SQLITE_MAX_COLUMN must not exceed 32767
2447 #endif
2448 #if SQLITE_MAX_TRIGGER_DEPTH<1
2449 # error SQLITE_MAX_TRIGGER_DEPTH must be at least 1
2450 #endif
2451 #if SQLITE_MAX_WORKER_THREADS<0 || SQLITE_MAX_WORKER_THREADS>50
2452 # error SQLITE_MAX_WORKER_THREADS must be between 0 and 50
2453 #endif
2454 
2455 
2456 /*
2457 ** Change the value of a limit.  Report the old value.
2458 ** If an invalid limit index is supplied, report -1.
2459 ** Make no changes but still report the old value if the
2460 ** new limit is negative.
2461 **
2462 ** A new lower limit does not shrink existing constructs.
2463 ** It merely prevents new constructs that exceed the limit
2464 ** from forming.
2465 */
2466 int sqlite3_limit(sqlite3 *db, int limitId, int newLimit){
2467   int oldLimit;
2468 
2469 #ifdef SQLITE_ENABLE_API_ARMOR
2470   if( !sqlite3SafetyCheckOk(db) ){
2471     (void)SQLITE_MISUSE_BKPT;
2472     return -1;
2473   }
2474 #endif
2475 
2476   /* EVIDENCE-OF: R-30189-54097 For each limit category SQLITE_LIMIT_NAME
2477   ** there is a hard upper bound set at compile-time by a C preprocessor
2478   ** macro called SQLITE_MAX_NAME. (The "_LIMIT_" in the name is changed to
2479   ** "_MAX_".)
2480   */
2481   assert( aHardLimit[SQLITE_LIMIT_LENGTH]==SQLITE_MAX_LENGTH );
2482   assert( aHardLimit[SQLITE_LIMIT_SQL_LENGTH]==SQLITE_MAX_SQL_LENGTH );
2483   assert( aHardLimit[SQLITE_LIMIT_COLUMN]==SQLITE_MAX_COLUMN );
2484   assert( aHardLimit[SQLITE_LIMIT_EXPR_DEPTH]==SQLITE_MAX_EXPR_DEPTH );
2485   assert( aHardLimit[SQLITE_LIMIT_COMPOUND_SELECT]==SQLITE_MAX_COMPOUND_SELECT);
2486   assert( aHardLimit[SQLITE_LIMIT_VDBE_OP]==SQLITE_MAX_VDBE_OP );
2487   assert( aHardLimit[SQLITE_LIMIT_FUNCTION_ARG]==SQLITE_MAX_FUNCTION_ARG );
2488   assert( aHardLimit[SQLITE_LIMIT_ATTACHED]==SQLITE_MAX_ATTACHED );
2489   assert( aHardLimit[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]==
2490                                                SQLITE_MAX_LIKE_PATTERN_LENGTH );
2491   assert( aHardLimit[SQLITE_LIMIT_VARIABLE_NUMBER]==SQLITE_MAX_VARIABLE_NUMBER);
2492   assert( aHardLimit[SQLITE_LIMIT_TRIGGER_DEPTH]==SQLITE_MAX_TRIGGER_DEPTH );
2493   assert( aHardLimit[SQLITE_LIMIT_WORKER_THREADS]==SQLITE_MAX_WORKER_THREADS );
2494   assert( SQLITE_LIMIT_WORKER_THREADS==(SQLITE_N_LIMIT-1) );
2495 
2496 
2497   if( limitId<0 || limitId>=SQLITE_N_LIMIT ){
2498     return -1;
2499   }
2500   oldLimit = db->aLimit[limitId];
2501   if( newLimit>=0 ){                   /* IMP: R-52476-28732 */
2502     if( newLimit>aHardLimit[limitId] ){
2503       newLimit = aHardLimit[limitId];  /* IMP: R-51463-25634 */
2504     }
2505     db->aLimit[limitId] = newLimit;
2506   }
2507   return oldLimit;                     /* IMP: R-53341-35419 */
2508 }
2509 
2510 /*
2511 ** This function is used to parse both URIs and non-URI filenames passed by the
2512 ** user to API functions sqlite3_open() or sqlite3_open_v2(), and for database
2513 ** URIs specified as part of ATTACH statements.
2514 **
2515 ** The first argument to this function is the name of the VFS to use (or
2516 ** a NULL to signify the default VFS) if the URI does not contain a "vfs=xxx"
2517 ** query parameter. The second argument contains the URI (or non-URI filename)
2518 ** itself. When this function is called the *pFlags variable should contain
2519 ** the default flags to open the database handle with. The value stored in
2520 ** *pFlags may be updated before returning if the URI filename contains
2521 ** "cache=xxx" or "mode=xxx" query parameters.
2522 **
2523 ** If successful, SQLITE_OK is returned. In this case *ppVfs is set to point to
2524 ** the VFS that should be used to open the database file. *pzFile is set to
2525 ** point to a buffer containing the name of the file to open. It is the
2526 ** responsibility of the caller to eventually call sqlite3_free() to release
2527 ** this buffer.
2528 **
2529 ** If an error occurs, then an SQLite error code is returned and *pzErrMsg
2530 ** may be set to point to a buffer containing an English language error
2531 ** message. It is the responsibility of the caller to eventually release
2532 ** this buffer by calling sqlite3_free().
2533 */
2534 int sqlite3ParseUri(
2535   const char *zDefaultVfs,        /* VFS to use if no "vfs=xxx" query option */
2536   const char *zUri,               /* Nul-terminated URI to parse */
2537   unsigned int *pFlags,           /* IN/OUT: SQLITE_OPEN_XXX flags */
2538   sqlite3_vfs **ppVfs,            /* OUT: VFS to use */
2539   char **pzFile,                  /* OUT: Filename component of URI */
2540   char **pzErrMsg                 /* OUT: Error message (if rc!=SQLITE_OK) */
2541 ){
2542   int rc = SQLITE_OK;
2543   unsigned int flags = *pFlags;
2544   const char *zVfs = zDefaultVfs;
2545   char *zFile;
2546   char c;
2547   int nUri = sqlite3Strlen30(zUri);
2548 
2549   assert( *pzErrMsg==0 );
2550 
2551   if( ((flags & SQLITE_OPEN_URI)             /* IMP: R-48725-32206 */
2552             || sqlite3GlobalConfig.bOpenUri) /* IMP: R-51689-46548 */
2553    && nUri>=5 && memcmp(zUri, "file:", 5)==0 /* IMP: R-57884-37496 */
2554   ){
2555     char *zOpt;
2556     int eState;                   /* Parser state when parsing URI */
2557     int iIn;                      /* Input character index */
2558     int iOut = 0;                 /* Output character index */
2559     u64 nByte = nUri+2;           /* Bytes of space to allocate */
2560 
2561     /* Make sure the SQLITE_OPEN_URI flag is set to indicate to the VFS xOpen
2562     ** method that there may be extra parameters following the file-name.  */
2563     flags |= SQLITE_OPEN_URI;
2564 
2565     for(iIn=0; iIn<nUri; iIn++) nByte += (zUri[iIn]=='&');
2566     zFile = sqlite3_malloc64(nByte);
2567     if( !zFile ) return SQLITE_NOMEM_BKPT;
2568 
2569     iIn = 5;
2570 #ifdef SQLITE_ALLOW_URI_AUTHORITY
2571     if( strncmp(zUri+5, "///", 3)==0 ){
2572       iIn = 7;
2573       /* The following condition causes URIs with five leading / characters
2574       ** like file://///host/path to be converted into UNCs like //host/path.
2575       ** The correct URI for that UNC has only two or four leading / characters
2576       ** file://host/path or file:////host/path.  But 5 leading slashes is a
2577       ** common error, we are told, so we handle it as a special case. */
2578       if( strncmp(zUri+7, "///", 3)==0 ){ iIn++; }
2579     }else if( strncmp(zUri+5, "//localhost/", 12)==0 ){
2580       iIn = 16;
2581     }
2582 #else
2583     /* Discard the scheme and authority segments of the URI. */
2584     if( zUri[5]=='/' && zUri[6]=='/' ){
2585       iIn = 7;
2586       while( zUri[iIn] && zUri[iIn]!='/' ) iIn++;
2587       if( iIn!=7 && (iIn!=16 || memcmp("localhost", &zUri[7], 9)) ){
2588         *pzErrMsg = sqlite3_mprintf("invalid uri authority: %.*s",
2589             iIn-7, &zUri[7]);
2590         rc = SQLITE_ERROR;
2591         goto parse_uri_out;
2592       }
2593     }
2594 #endif
2595 
2596     /* Copy the filename and any query parameters into the zFile buffer.
2597     ** Decode %HH escape codes along the way.
2598     **
2599     ** Within this loop, variable eState may be set to 0, 1 or 2, depending
2600     ** on the parsing context. As follows:
2601     **
2602     **   0: Parsing file-name.
2603     **   1: Parsing name section of a name=value query parameter.
2604     **   2: Parsing value section of a name=value query parameter.
2605     */
2606     eState = 0;
2607     while( (c = zUri[iIn])!=0 && c!='#' ){
2608       iIn++;
2609       if( c=='%'
2610        && sqlite3Isxdigit(zUri[iIn])
2611        && sqlite3Isxdigit(zUri[iIn+1])
2612       ){
2613         int octet = (sqlite3HexToInt(zUri[iIn++]) << 4);
2614         octet += sqlite3HexToInt(zUri[iIn++]);
2615 
2616         assert( octet>=0 && octet<256 );
2617         if( octet==0 ){
2618           /* This branch is taken when "%00" appears within the URI. In this
2619           ** case we ignore all text in the remainder of the path, name or
2620           ** value currently being parsed. So ignore the current character
2621           ** and skip to the next "?", "=" or "&", as appropriate. */
2622           while( (c = zUri[iIn])!=0 && c!='#'
2623               && (eState!=0 || c!='?')
2624               && (eState!=1 || (c!='=' && c!='&'))
2625               && (eState!=2 || c!='&')
2626           ){
2627             iIn++;
2628           }
2629           continue;
2630         }
2631         c = octet;
2632       }else if( eState==1 && (c=='&' || c=='=') ){
2633         if( zFile[iOut-1]==0 ){
2634           /* An empty option name. Ignore this option altogether. */
2635           while( zUri[iIn] && zUri[iIn]!='#' && zUri[iIn-1]!='&' ) iIn++;
2636           continue;
2637         }
2638         if( c=='&' ){
2639           zFile[iOut++] = '\0';
2640         }else{
2641           eState = 2;
2642         }
2643         c = 0;
2644       }else if( (eState==0 && c=='?') || (eState==2 && c=='&') ){
2645         c = 0;
2646         eState = 1;
2647       }
2648       zFile[iOut++] = c;
2649     }
2650     if( eState==1 ) zFile[iOut++] = '\0';
2651     zFile[iOut++] = '\0';
2652     zFile[iOut++] = '\0';
2653 
2654     /* Check if there were any options specified that should be interpreted
2655     ** here. Options that are interpreted here include "vfs" and those that
2656     ** correspond to flags that may be passed to the sqlite3_open_v2()
2657     ** method. */
2658     zOpt = &zFile[sqlite3Strlen30(zFile)+1];
2659     while( zOpt[0] ){
2660       int nOpt = sqlite3Strlen30(zOpt);
2661       char *zVal = &zOpt[nOpt+1];
2662       int nVal = sqlite3Strlen30(zVal);
2663 
2664       if( nOpt==3 && memcmp("vfs", zOpt, 3)==0 ){
2665         zVfs = zVal;
2666       }else{
2667         struct OpenMode {
2668           const char *z;
2669           int mode;
2670         } *aMode = 0;
2671         char *zModeType = 0;
2672         int mask = 0;
2673         int limit = 0;
2674 
2675         if( nOpt==5 && memcmp("cache", zOpt, 5)==0 ){
2676           static struct OpenMode aCacheMode[] = {
2677             { "shared",  SQLITE_OPEN_SHAREDCACHE },
2678             { "private", SQLITE_OPEN_PRIVATECACHE },
2679             { 0, 0 }
2680           };
2681 
2682           mask = SQLITE_OPEN_SHAREDCACHE|SQLITE_OPEN_PRIVATECACHE;
2683           aMode = aCacheMode;
2684           limit = mask;
2685           zModeType = "cache";
2686         }
2687         if( nOpt==4 && memcmp("mode", zOpt, 4)==0 ){
2688           static struct OpenMode aOpenMode[] = {
2689             { "ro",  SQLITE_OPEN_READONLY },
2690             { "rw",  SQLITE_OPEN_READWRITE },
2691             { "rwc", SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE },
2692             { "memory", SQLITE_OPEN_MEMORY },
2693             { 0, 0 }
2694           };
2695 
2696           mask = SQLITE_OPEN_READONLY | SQLITE_OPEN_READWRITE
2697                    | SQLITE_OPEN_CREATE | SQLITE_OPEN_MEMORY;
2698           aMode = aOpenMode;
2699           limit = mask & flags;
2700           zModeType = "access";
2701         }
2702 
2703         if( aMode ){
2704           int i;
2705           int mode = 0;
2706           for(i=0; aMode[i].z; i++){
2707             const char *z = aMode[i].z;
2708             if( nVal==sqlite3Strlen30(z) && 0==memcmp(zVal, z, nVal) ){
2709               mode = aMode[i].mode;
2710               break;
2711             }
2712           }
2713           if( mode==0 ){
2714             *pzErrMsg = sqlite3_mprintf("no such %s mode: %s", zModeType, zVal);
2715             rc = SQLITE_ERROR;
2716             goto parse_uri_out;
2717           }
2718           if( (mode & ~SQLITE_OPEN_MEMORY)>limit ){
2719             *pzErrMsg = sqlite3_mprintf("%s mode not allowed: %s",
2720                                         zModeType, zVal);
2721             rc = SQLITE_PERM;
2722             goto parse_uri_out;
2723           }
2724           flags = (flags & ~mask) | mode;
2725         }
2726       }
2727 
2728       zOpt = &zVal[nVal+1];
2729     }
2730 
2731   }else{
2732     zFile = sqlite3_malloc64(nUri+2);
2733     if( !zFile ) return SQLITE_NOMEM_BKPT;
2734     memcpy(zFile, zUri, nUri);
2735     zFile[nUri] = '\0';
2736     zFile[nUri+1] = '\0';
2737     flags &= ~SQLITE_OPEN_URI;
2738   }
2739 
2740   *ppVfs = sqlite3_vfs_find(zVfs);
2741   if( *ppVfs==0 ){
2742     *pzErrMsg = sqlite3_mprintf("no such vfs: %s", zVfs);
2743     rc = SQLITE_ERROR;
2744   }
2745  parse_uri_out:
2746   if( rc!=SQLITE_OK ){
2747     sqlite3_free(zFile);
2748     zFile = 0;
2749   }
2750   *pFlags = flags;
2751   *pzFile = zFile;
2752   return rc;
2753 }
2754 
2755 
2756 /*
2757 ** This routine does the work of opening a database on behalf of
2758 ** sqlite3_open() and sqlite3_open16(). The database filename "zFilename"
2759 ** is UTF-8 encoded.
2760 */
2761 static int openDatabase(
2762   const char *zFilename, /* Database filename UTF-8 encoded */
2763   sqlite3 **ppDb,        /* OUT: Returned database handle */
2764   unsigned int flags,    /* Operational flags */
2765   const char *zVfs       /* Name of the VFS to use */
2766 ){
2767   sqlite3 *db;                    /* Store allocated handle here */
2768   int rc;                         /* Return code */
2769   int isThreadsafe;               /* True for threadsafe connections */
2770   char *zOpen = 0;                /* Filename argument to pass to BtreeOpen() */
2771   char *zErrMsg = 0;              /* Error message from sqlite3ParseUri() */
2772 
2773 #ifdef SQLITE_ENABLE_API_ARMOR
2774   if( ppDb==0 ) return SQLITE_MISUSE_BKPT;
2775 #endif
2776   *ppDb = 0;
2777 #ifndef SQLITE_OMIT_AUTOINIT
2778   rc = sqlite3_initialize();
2779   if( rc ) return rc;
2780 #endif
2781 
2782   /* Only allow sensible combinations of bits in the flags argument.
2783   ** Throw an error if any non-sense combination is used.  If we
2784   ** do not block illegal combinations here, it could trigger
2785   ** assert() statements in deeper layers.  Sensible combinations
2786   ** are:
2787   **
2788   **  1:  SQLITE_OPEN_READONLY
2789   **  2:  SQLITE_OPEN_READWRITE
2790   **  6:  SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE
2791   */
2792   assert( SQLITE_OPEN_READONLY  == 0x01 );
2793   assert( SQLITE_OPEN_READWRITE == 0x02 );
2794   assert( SQLITE_OPEN_CREATE    == 0x04 );
2795   testcase( (1<<(flags&7))==0x02 ); /* READONLY */
2796   testcase( (1<<(flags&7))==0x04 ); /* READWRITE */
2797   testcase( (1<<(flags&7))==0x40 ); /* READWRITE | CREATE */
2798   if( ((1<<(flags&7)) & 0x46)==0 ){
2799     return SQLITE_MISUSE_BKPT;  /* IMP: R-65497-44594 */
2800   }
2801 
2802   if( sqlite3GlobalConfig.bCoreMutex==0 ){
2803     isThreadsafe = 0;
2804   }else if( flags & SQLITE_OPEN_NOMUTEX ){
2805     isThreadsafe = 0;
2806   }else if( flags & SQLITE_OPEN_FULLMUTEX ){
2807     isThreadsafe = 1;
2808   }else{
2809     isThreadsafe = sqlite3GlobalConfig.bFullMutex;
2810   }
2811   if( flags & SQLITE_OPEN_PRIVATECACHE ){
2812     flags &= ~SQLITE_OPEN_SHAREDCACHE;
2813   }else if( sqlite3GlobalConfig.sharedCacheEnabled ){
2814     flags |= SQLITE_OPEN_SHAREDCACHE;
2815   }
2816 
2817   /* Remove harmful bits from the flags parameter
2818   **
2819   ** The SQLITE_OPEN_NOMUTEX and SQLITE_OPEN_FULLMUTEX flags were
2820   ** dealt with in the previous code block.  Besides these, the only
2821   ** valid input flags for sqlite3_open_v2() are SQLITE_OPEN_READONLY,
2822   ** SQLITE_OPEN_READWRITE, SQLITE_OPEN_CREATE, SQLITE_OPEN_SHAREDCACHE,
2823   ** SQLITE_OPEN_PRIVATECACHE, and some reserved bits.  Silently mask
2824   ** off all other flags.
2825   */
2826   flags &=  ~( SQLITE_OPEN_DELETEONCLOSE |
2827                SQLITE_OPEN_EXCLUSIVE |
2828                SQLITE_OPEN_MAIN_DB |
2829                SQLITE_OPEN_TEMP_DB |
2830                SQLITE_OPEN_TRANSIENT_DB |
2831                SQLITE_OPEN_MAIN_JOURNAL |
2832                SQLITE_OPEN_TEMP_JOURNAL |
2833                SQLITE_OPEN_SUBJOURNAL |
2834                SQLITE_OPEN_MASTER_JOURNAL |
2835                SQLITE_OPEN_NOMUTEX |
2836                SQLITE_OPEN_FULLMUTEX |
2837                SQLITE_OPEN_WAL
2838              );
2839 
2840   /* Allocate the sqlite data structure */
2841   db = sqlite3MallocZero( sizeof(sqlite3) );
2842   if( db==0 ) goto opendb_out;
2843   if( isThreadsafe ){
2844     db->mutex = sqlite3MutexAlloc(SQLITE_MUTEX_RECURSIVE);
2845     if( db->mutex==0 ){
2846       sqlite3_free(db);
2847       db = 0;
2848       goto opendb_out;
2849     }
2850   }
2851   sqlite3_mutex_enter(db->mutex);
2852   db->errMask = 0xff;
2853   db->nDb = 2;
2854   db->magic = SQLITE_MAGIC_BUSY;
2855   db->aDb = db->aDbStatic;
2856 
2857   assert( sizeof(db->aLimit)==sizeof(aHardLimit) );
2858   memcpy(db->aLimit, aHardLimit, sizeof(db->aLimit));
2859   db->aLimit[SQLITE_LIMIT_WORKER_THREADS] = SQLITE_DEFAULT_WORKER_THREADS;
2860   db->autoCommit = 1;
2861   db->nextAutovac = -1;
2862   db->szMmap = sqlite3GlobalConfig.szMmap;
2863   db->nextPagesize = 0;
2864   db->nMaxSorterMmap = 0x7FFFFFFF;
2865   db->flags |= SQLITE_ShortColNames | SQLITE_EnableTrigger | SQLITE_CacheSpill
2866 #if !defined(SQLITE_DEFAULT_AUTOMATIC_INDEX) || SQLITE_DEFAULT_AUTOMATIC_INDEX
2867                  | SQLITE_AutoIndex
2868 #endif
2869 #if SQLITE_DEFAULT_CKPTFULLFSYNC
2870                  | SQLITE_CkptFullFSync
2871 #endif
2872 #if SQLITE_DEFAULT_FILE_FORMAT<4
2873                  | SQLITE_LegacyFileFmt
2874 #endif
2875 #ifdef SQLITE_ENABLE_LOAD_EXTENSION
2876                  | SQLITE_LoadExtension
2877 #endif
2878 #if SQLITE_DEFAULT_RECURSIVE_TRIGGERS
2879                  | SQLITE_RecTriggers
2880 #endif
2881 #if defined(SQLITE_DEFAULT_FOREIGN_KEYS) && SQLITE_DEFAULT_FOREIGN_KEYS
2882                  | SQLITE_ForeignKeys
2883 #endif
2884 #if defined(SQLITE_REVERSE_UNORDERED_SELECTS)
2885                  | SQLITE_ReverseOrder
2886 #endif
2887 #if defined(SQLITE_ENABLE_OVERSIZE_CELL_CHECK)
2888                  | SQLITE_CellSizeCk
2889 #endif
2890 #if defined(SQLITE_ENABLE_FTS3_TOKENIZER)
2891                  | SQLITE_Fts3Tokenizer
2892 #endif
2893       ;
2894   sqlite3HashInit(&db->aCollSeq);
2895 #ifndef SQLITE_OMIT_VIRTUALTABLE
2896   sqlite3HashInit(&db->aModule);
2897 #endif
2898 
2899   /* Add the default collation sequence BINARY. BINARY works for both UTF-8
2900   ** and UTF-16, so add a version for each to avoid any unnecessary
2901   ** conversions. The only error that can occur here is a malloc() failure.
2902   **
2903   ** EVIDENCE-OF: R-52786-44878 SQLite defines three built-in collating
2904   ** functions:
2905   */
2906   createCollation(db, sqlite3StrBINARY, SQLITE_UTF8, 0, binCollFunc, 0);
2907   createCollation(db, sqlite3StrBINARY, SQLITE_UTF16BE, 0, binCollFunc, 0);
2908   createCollation(db, sqlite3StrBINARY, SQLITE_UTF16LE, 0, binCollFunc, 0);
2909   createCollation(db, "NOCASE", SQLITE_UTF8, 0, nocaseCollatingFunc, 0);
2910   createCollation(db, "RTRIM", SQLITE_UTF8, (void*)1, binCollFunc, 0);
2911   if( db->mallocFailed ){
2912     goto opendb_out;
2913   }
2914   /* EVIDENCE-OF: R-08308-17224 The default collating function for all
2915   ** strings is BINARY.
2916   */
2917   db->pDfltColl = sqlite3FindCollSeq(db, SQLITE_UTF8, sqlite3StrBINARY, 0);
2918   assert( db->pDfltColl!=0 );
2919 
2920   /* Parse the filename/URI argument. */
2921   db->openFlags = flags;
2922   rc = sqlite3ParseUri(zVfs, zFilename, &flags, &db->pVfs, &zOpen, &zErrMsg);
2923   if( rc!=SQLITE_OK ){
2924     if( rc==SQLITE_NOMEM ) sqlite3OomFault(db);
2925     sqlite3ErrorWithMsg(db, rc, zErrMsg ? "%s" : 0, zErrMsg);
2926     sqlite3_free(zErrMsg);
2927     goto opendb_out;
2928   }
2929 
2930   /* Open the backend database driver */
2931   rc = sqlite3BtreeOpen(db->pVfs, zOpen, db, &db->aDb[0].pBt, 0,
2932                         flags | SQLITE_OPEN_MAIN_DB);
2933   if( rc!=SQLITE_OK ){
2934     if( rc==SQLITE_IOERR_NOMEM ){
2935       rc = SQLITE_NOMEM_BKPT;
2936     }
2937     sqlite3Error(db, rc);
2938     goto opendb_out;
2939   }
2940   sqlite3BtreeEnter(db->aDb[0].pBt);
2941   db->aDb[0].pSchema = sqlite3SchemaGet(db, db->aDb[0].pBt);
2942   if( !db->mallocFailed ) ENC(db) = SCHEMA_ENC(db);
2943   sqlite3BtreeLeave(db->aDb[0].pBt);
2944   db->aDb[1].pSchema = sqlite3SchemaGet(db, 0);
2945 
2946   /* The default safety_level for the main database is FULL; for the temp
2947   ** database it is OFF. This matches the pager layer defaults.
2948   */
2949   db->aDb[0].zDbSName = "main";
2950   db->aDb[0].safety_level = SQLITE_DEFAULT_SYNCHRONOUS+1;
2951   db->aDb[1].zDbSName = "temp";
2952   db->aDb[1].safety_level = PAGER_SYNCHRONOUS_OFF;
2953 
2954   db->magic = SQLITE_MAGIC_OPEN;
2955   if( db->mallocFailed ){
2956     goto opendb_out;
2957   }
2958 
2959   /* Register all built-in functions, but do not attempt to read the
2960   ** database schema yet. This is delayed until the first time the database
2961   ** is accessed.
2962   */
2963   sqlite3Error(db, SQLITE_OK);
2964   sqlite3RegisterPerConnectionBuiltinFunctions(db);
2965   rc = sqlite3_errcode(db);
2966 
2967 #ifdef SQLITE_ENABLE_FTS5
2968   /* Register any built-in FTS5 module before loading the automatic
2969   ** extensions. This allows automatic extensions to register FTS5
2970   ** tokenizers and auxiliary functions.  */
2971   if( !db->mallocFailed && rc==SQLITE_OK ){
2972     rc = sqlite3Fts5Init(db);
2973   }
2974 #endif
2975 
2976   /* Load automatic extensions - extensions that have been registered
2977   ** using the sqlite3_automatic_extension() API.
2978   */
2979   if( rc==SQLITE_OK ){
2980     sqlite3AutoLoadExtensions(db);
2981     rc = sqlite3_errcode(db);
2982     if( rc!=SQLITE_OK ){
2983       goto opendb_out;
2984     }
2985   }
2986 
2987 #ifdef SQLITE_ENABLE_FTS1
2988   if( !db->mallocFailed ){
2989     extern int sqlite3Fts1Init(sqlite3*);
2990     rc = sqlite3Fts1Init(db);
2991   }
2992 #endif
2993 
2994 #ifdef SQLITE_ENABLE_FTS2
2995   if( !db->mallocFailed && rc==SQLITE_OK ){
2996     extern int sqlite3Fts2Init(sqlite3*);
2997     rc = sqlite3Fts2Init(db);
2998   }
2999 #endif
3000 
3001 #ifdef SQLITE_ENABLE_FTS3 /* automatically defined by SQLITE_ENABLE_FTS4 */
3002   if( !db->mallocFailed && rc==SQLITE_OK ){
3003     rc = sqlite3Fts3Init(db);
3004   }
3005 #endif
3006 
3007 #ifdef SQLITE_ENABLE_ICU
3008   if( !db->mallocFailed && rc==SQLITE_OK ){
3009     rc = sqlite3IcuInit(db);
3010   }
3011 #endif
3012 
3013 #ifdef SQLITE_ENABLE_RTREE
3014   if( !db->mallocFailed && rc==SQLITE_OK){
3015     rc = sqlite3RtreeInit(db);
3016   }
3017 #endif
3018 
3019 #ifdef SQLITE_ENABLE_DBSTAT_VTAB
3020   if( !db->mallocFailed && rc==SQLITE_OK){
3021     rc = sqlite3DbstatRegister(db);
3022   }
3023 #endif
3024 
3025 #ifdef SQLITE_ENABLE_JSON1
3026   if( !db->mallocFailed && rc==SQLITE_OK){
3027     rc = sqlite3Json1Init(db);
3028   }
3029 #endif
3030 
3031   /* -DSQLITE_DEFAULT_LOCKING_MODE=1 makes EXCLUSIVE the default locking
3032   ** mode.  -DSQLITE_DEFAULT_LOCKING_MODE=0 make NORMAL the default locking
3033   ** mode.  Doing nothing at all also makes NORMAL the default.
3034   */
3035 #ifdef SQLITE_DEFAULT_LOCKING_MODE
3036   db->dfltLockMode = SQLITE_DEFAULT_LOCKING_MODE;
3037   sqlite3PagerLockingMode(sqlite3BtreePager(db->aDb[0].pBt),
3038                           SQLITE_DEFAULT_LOCKING_MODE);
3039 #endif
3040 
3041   if( rc ) sqlite3Error(db, rc);
3042 
3043   /* Enable the lookaside-malloc subsystem */
3044   setupLookaside(db, 0, sqlite3GlobalConfig.szLookaside,
3045                         sqlite3GlobalConfig.nLookaside);
3046 
3047   sqlite3_wal_autocheckpoint(db, SQLITE_DEFAULT_WAL_AUTOCHECKPOINT);
3048 
3049 opendb_out:
3050   if( db ){
3051     assert( db->mutex!=0 || isThreadsafe==0
3052            || sqlite3GlobalConfig.bFullMutex==0 );
3053     sqlite3_mutex_leave(db->mutex);
3054   }
3055   rc = sqlite3_errcode(db);
3056   assert( db!=0 || rc==SQLITE_NOMEM );
3057   if( rc==SQLITE_NOMEM ){
3058     sqlite3_close(db);
3059     db = 0;
3060   }else if( rc!=SQLITE_OK ){
3061     db->magic = SQLITE_MAGIC_SICK;
3062   }
3063   *ppDb = db;
3064 #ifdef SQLITE_ENABLE_SQLLOG
3065   if( sqlite3GlobalConfig.xSqllog ){
3066     /* Opening a db handle. Fourth parameter is passed 0. */
3067     void *pArg = sqlite3GlobalConfig.pSqllogArg;
3068     sqlite3GlobalConfig.xSqllog(pArg, db, zFilename, 0);
3069   }
3070 #endif
3071 #if defined(SQLITE_HAS_CODEC)
3072   if( rc==SQLITE_OK ){
3073     const char *zHexKey = sqlite3_uri_parameter(zOpen, "hexkey");
3074     if( zHexKey && zHexKey[0] ){
3075       u8 iByte;
3076       int i;
3077       char zKey[40];
3078       for(i=0, iByte=0; i<sizeof(zKey)*2 && sqlite3Isxdigit(zHexKey[i]); i++){
3079         iByte = (iByte<<4) + sqlite3HexToInt(zHexKey[i]);
3080         if( (i&1)!=0 ) zKey[i/2] = iByte;
3081       }
3082       sqlite3_key_v2(db, 0, zKey, i/2);
3083     }
3084   }
3085 #endif
3086   sqlite3_free(zOpen);
3087   return rc & 0xff;
3088 }
3089 
3090 /*
3091 ** Open a new database handle.
3092 */
3093 int sqlite3_open(
3094   const char *zFilename,
3095   sqlite3 **ppDb
3096 ){
3097   return openDatabase(zFilename, ppDb,
3098                       SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
3099 }
3100 int sqlite3_open_v2(
3101   const char *filename,   /* Database filename (UTF-8) */
3102   sqlite3 **ppDb,         /* OUT: SQLite db handle */
3103   int flags,              /* Flags */
3104   const char *zVfs        /* Name of VFS module to use */
3105 ){
3106   return openDatabase(filename, ppDb, (unsigned int)flags, zVfs);
3107 }
3108 
3109 #ifndef SQLITE_OMIT_UTF16
3110 /*
3111 ** Open a new database handle.
3112 */
3113 int sqlite3_open16(
3114   const void *zFilename,
3115   sqlite3 **ppDb
3116 ){
3117   char const *zFilename8;   /* zFilename encoded in UTF-8 instead of UTF-16 */
3118   sqlite3_value *pVal;
3119   int rc;
3120 
3121 #ifdef SQLITE_ENABLE_API_ARMOR
3122   if( ppDb==0 ) return SQLITE_MISUSE_BKPT;
3123 #endif
3124   *ppDb = 0;
3125 #ifndef SQLITE_OMIT_AUTOINIT
3126   rc = sqlite3_initialize();
3127   if( rc ) return rc;
3128 #endif
3129   if( zFilename==0 ) zFilename = "\000\000";
3130   pVal = sqlite3ValueNew(0);
3131   sqlite3ValueSetStr(pVal, -1, zFilename, SQLITE_UTF16NATIVE, SQLITE_STATIC);
3132   zFilename8 = sqlite3ValueText(pVal, SQLITE_UTF8);
3133   if( zFilename8 ){
3134     rc = openDatabase(zFilename8, ppDb,
3135                       SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
3136     assert( *ppDb || rc==SQLITE_NOMEM );
3137     if( rc==SQLITE_OK && !DbHasProperty(*ppDb, 0, DB_SchemaLoaded) ){
3138       SCHEMA_ENC(*ppDb) = ENC(*ppDb) = SQLITE_UTF16NATIVE;
3139     }
3140   }else{
3141     rc = SQLITE_NOMEM_BKPT;
3142   }
3143   sqlite3ValueFree(pVal);
3144 
3145   return rc & 0xff;
3146 }
3147 #endif /* SQLITE_OMIT_UTF16 */
3148 
3149 /*
3150 ** Register a new collation sequence with the database handle db.
3151 */
3152 int sqlite3_create_collation(
3153   sqlite3* db,
3154   const char *zName,
3155   int enc,
3156   void* pCtx,
3157   int(*xCompare)(void*,int,const void*,int,const void*)
3158 ){
3159   return sqlite3_create_collation_v2(db, zName, enc, pCtx, xCompare, 0);
3160 }
3161 
3162 /*
3163 ** Register a new collation sequence with the database handle db.
3164 */
3165 int sqlite3_create_collation_v2(
3166   sqlite3* db,
3167   const char *zName,
3168   int enc,
3169   void* pCtx,
3170   int(*xCompare)(void*,int,const void*,int,const void*),
3171   void(*xDel)(void*)
3172 ){
3173   int rc;
3174 
3175 #ifdef SQLITE_ENABLE_API_ARMOR
3176   if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
3177 #endif
3178   sqlite3_mutex_enter(db->mutex);
3179   assert( !db->mallocFailed );
3180   rc = createCollation(db, zName, (u8)enc, pCtx, xCompare, xDel);
3181   rc = sqlite3ApiExit(db, rc);
3182   sqlite3_mutex_leave(db->mutex);
3183   return rc;
3184 }
3185 
3186 #ifndef SQLITE_OMIT_UTF16
3187 /*
3188 ** Register a new collation sequence with the database handle db.
3189 */
3190 int sqlite3_create_collation16(
3191   sqlite3* db,
3192   const void *zName,
3193   int enc,
3194   void* pCtx,
3195   int(*xCompare)(void*,int,const void*,int,const void*)
3196 ){
3197   int rc = SQLITE_OK;
3198   char *zName8;
3199 
3200 #ifdef SQLITE_ENABLE_API_ARMOR
3201   if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
3202 #endif
3203   sqlite3_mutex_enter(db->mutex);
3204   assert( !db->mallocFailed );
3205   zName8 = sqlite3Utf16to8(db, zName, -1, SQLITE_UTF16NATIVE);
3206   if( zName8 ){
3207     rc = createCollation(db, zName8, (u8)enc, pCtx, xCompare, 0);
3208     sqlite3DbFree(db, zName8);
3209   }
3210   rc = sqlite3ApiExit(db, rc);
3211   sqlite3_mutex_leave(db->mutex);
3212   return rc;
3213 }
3214 #endif /* SQLITE_OMIT_UTF16 */
3215 
3216 /*
3217 ** Register a collation sequence factory callback with the database handle
3218 ** db. Replace any previously installed collation sequence factory.
3219 */
3220 int sqlite3_collation_needed(
3221   sqlite3 *db,
3222   void *pCollNeededArg,
3223   void(*xCollNeeded)(void*,sqlite3*,int eTextRep,const char*)
3224 ){
3225 #ifdef SQLITE_ENABLE_API_ARMOR
3226   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3227 #endif
3228   sqlite3_mutex_enter(db->mutex);
3229   db->xCollNeeded = xCollNeeded;
3230   db->xCollNeeded16 = 0;
3231   db->pCollNeededArg = pCollNeededArg;
3232   sqlite3_mutex_leave(db->mutex);
3233   return SQLITE_OK;
3234 }
3235 
3236 #ifndef SQLITE_OMIT_UTF16
3237 /*
3238 ** Register a collation sequence factory callback with the database handle
3239 ** db. Replace any previously installed collation sequence factory.
3240 */
3241 int sqlite3_collation_needed16(
3242   sqlite3 *db,
3243   void *pCollNeededArg,
3244   void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*)
3245 ){
3246 #ifdef SQLITE_ENABLE_API_ARMOR
3247   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3248 #endif
3249   sqlite3_mutex_enter(db->mutex);
3250   db->xCollNeeded = 0;
3251   db->xCollNeeded16 = xCollNeeded16;
3252   db->pCollNeededArg = pCollNeededArg;
3253   sqlite3_mutex_leave(db->mutex);
3254   return SQLITE_OK;
3255 }
3256 #endif /* SQLITE_OMIT_UTF16 */
3257 
3258 #ifndef SQLITE_OMIT_DEPRECATED
3259 /*
3260 ** This function is now an anachronism. It used to be used to recover from a
3261 ** malloc() failure, but SQLite now does this automatically.
3262 */
3263 int sqlite3_global_recover(void){
3264   return SQLITE_OK;
3265 }
3266 #endif
3267 
3268 /*
3269 ** Test to see whether or not the database connection is in autocommit
3270 ** mode.  Return TRUE if it is and FALSE if not.  Autocommit mode is on
3271 ** by default.  Autocommit is disabled by a BEGIN statement and reenabled
3272 ** by the next COMMIT or ROLLBACK.
3273 */
3274 int sqlite3_get_autocommit(sqlite3 *db){
3275 #ifdef SQLITE_ENABLE_API_ARMOR
3276   if( !sqlite3SafetyCheckOk(db) ){
3277     (void)SQLITE_MISUSE_BKPT;
3278     return 0;
3279   }
3280 #endif
3281   return db->autoCommit;
3282 }
3283 
3284 /*
3285 ** The following routines are substitutes for constants SQLITE_CORRUPT,
3286 ** SQLITE_MISUSE, SQLITE_CANTOPEN, SQLITE_NOMEM and possibly other error
3287 ** constants.  They serve two purposes:
3288 **
3289 **   1.  Serve as a convenient place to set a breakpoint in a debugger
3290 **       to detect when version error conditions occurs.
3291 **
3292 **   2.  Invoke sqlite3_log() to provide the source code location where
3293 **       a low-level error is first detected.
3294 */
3295 static int reportError(int iErr, int lineno, const char *zType){
3296   sqlite3_log(iErr, "%s at line %d of [%.10s]",
3297               zType, lineno, 20+sqlite3_sourceid());
3298   return iErr;
3299 }
3300 int sqlite3CorruptError(int lineno){
3301   testcase( sqlite3GlobalConfig.xLog!=0 );
3302   return reportError(SQLITE_CORRUPT, lineno, "database corruption");
3303 }
3304 int sqlite3MisuseError(int lineno){
3305   testcase( sqlite3GlobalConfig.xLog!=0 );
3306   return reportError(SQLITE_MISUSE, lineno, "misuse");
3307 }
3308 int sqlite3CantopenError(int lineno){
3309   testcase( sqlite3GlobalConfig.xLog!=0 );
3310   return reportError(SQLITE_CANTOPEN, lineno, "cannot open file");
3311 }
3312 #ifdef SQLITE_DEBUG
3313 int sqlite3NomemError(int lineno){
3314   testcase( sqlite3GlobalConfig.xLog!=0 );
3315   return reportError(SQLITE_NOMEM, lineno, "OOM");
3316 }
3317 int sqlite3IoerrnomemError(int lineno){
3318   testcase( sqlite3GlobalConfig.xLog!=0 );
3319   return reportError(SQLITE_IOERR_NOMEM, lineno, "I/O OOM error");
3320 }
3321 #endif
3322 
3323 #ifndef SQLITE_OMIT_DEPRECATED
3324 /*
3325 ** This is a convenience routine that makes sure that all thread-specific
3326 ** data for this thread has been deallocated.
3327 **
3328 ** SQLite no longer uses thread-specific data so this routine is now a
3329 ** no-op.  It is retained for historical compatibility.
3330 */
3331 void sqlite3_thread_cleanup(void){
3332 }
3333 #endif
3334 
3335 /*
3336 ** Return meta information about a specific column of a database table.
3337 ** See comment in sqlite3.h (sqlite.h.in) for details.
3338 */
3339 int sqlite3_table_column_metadata(
3340   sqlite3 *db,                /* Connection handle */
3341   const char *zDbName,        /* Database name or NULL */
3342   const char *zTableName,     /* Table name */
3343   const char *zColumnName,    /* Column name */
3344   char const **pzDataType,    /* OUTPUT: Declared data type */
3345   char const **pzCollSeq,     /* OUTPUT: Collation sequence name */
3346   int *pNotNull,              /* OUTPUT: True if NOT NULL constraint exists */
3347   int *pPrimaryKey,           /* OUTPUT: True if column part of PK */
3348   int *pAutoinc               /* OUTPUT: True if column is auto-increment */
3349 ){
3350   int rc;
3351   char *zErrMsg = 0;
3352   Table *pTab = 0;
3353   Column *pCol = 0;
3354   int iCol = 0;
3355   char const *zDataType = 0;
3356   char const *zCollSeq = 0;
3357   int notnull = 0;
3358   int primarykey = 0;
3359   int autoinc = 0;
3360 
3361 
3362 #ifdef SQLITE_ENABLE_API_ARMOR
3363   if( !sqlite3SafetyCheckOk(db) || zTableName==0 ){
3364     return SQLITE_MISUSE_BKPT;
3365   }
3366 #endif
3367 
3368   /* Ensure the database schema has been loaded */
3369   sqlite3_mutex_enter(db->mutex);
3370   sqlite3BtreeEnterAll(db);
3371   rc = sqlite3Init(db, &zErrMsg);
3372   if( SQLITE_OK!=rc ){
3373     goto error_out;
3374   }
3375 
3376   /* Locate the table in question */
3377   pTab = sqlite3FindTable(db, zTableName, zDbName);
3378   if( !pTab || pTab->pSelect ){
3379     pTab = 0;
3380     goto error_out;
3381   }
3382 
3383   /* Find the column for which info is requested */
3384   if( zColumnName==0 ){
3385     /* Query for existance of table only */
3386   }else{
3387     for(iCol=0; iCol<pTab->nCol; iCol++){
3388       pCol = &pTab->aCol[iCol];
3389       if( 0==sqlite3StrICmp(pCol->zName, zColumnName) ){
3390         break;
3391       }
3392     }
3393     if( iCol==pTab->nCol ){
3394       if( HasRowid(pTab) && sqlite3IsRowid(zColumnName) ){
3395         iCol = pTab->iPKey;
3396         pCol = iCol>=0 ? &pTab->aCol[iCol] : 0;
3397       }else{
3398         pTab = 0;
3399         goto error_out;
3400       }
3401     }
3402   }
3403 
3404   /* The following block stores the meta information that will be returned
3405   ** to the caller in local variables zDataType, zCollSeq, notnull, primarykey
3406   ** and autoinc. At this point there are two possibilities:
3407   **
3408   **     1. The specified column name was rowid", "oid" or "_rowid_"
3409   **        and there is no explicitly declared IPK column.
3410   **
3411   **     2. The table is not a view and the column name identified an
3412   **        explicitly declared column. Copy meta information from *pCol.
3413   */
3414   if( pCol ){
3415     zDataType = sqlite3ColumnType(pCol,0);
3416     zCollSeq = pCol->zColl;
3417     notnull = pCol->notNull!=0;
3418     primarykey  = (pCol->colFlags & COLFLAG_PRIMKEY)!=0;
3419     autoinc = pTab->iPKey==iCol && (pTab->tabFlags & TF_Autoincrement)!=0;
3420   }else{
3421     zDataType = "INTEGER";
3422     primarykey = 1;
3423   }
3424   if( !zCollSeq ){
3425     zCollSeq = sqlite3StrBINARY;
3426   }
3427 
3428 error_out:
3429   sqlite3BtreeLeaveAll(db);
3430 
3431   /* Whether the function call succeeded or failed, set the output parameters
3432   ** to whatever their local counterparts contain. If an error did occur,
3433   ** this has the effect of zeroing all output parameters.
3434   */
3435   if( pzDataType ) *pzDataType = zDataType;
3436   if( pzCollSeq ) *pzCollSeq = zCollSeq;
3437   if( pNotNull ) *pNotNull = notnull;
3438   if( pPrimaryKey ) *pPrimaryKey = primarykey;
3439   if( pAutoinc ) *pAutoinc = autoinc;
3440 
3441   if( SQLITE_OK==rc && !pTab ){
3442     sqlite3DbFree(db, zErrMsg);
3443     zErrMsg = sqlite3MPrintf(db, "no such table column: %s.%s", zTableName,
3444         zColumnName);
3445     rc = SQLITE_ERROR;
3446   }
3447   sqlite3ErrorWithMsg(db, rc, (zErrMsg?"%s":0), zErrMsg);
3448   sqlite3DbFree(db, zErrMsg);
3449   rc = sqlite3ApiExit(db, rc);
3450   sqlite3_mutex_leave(db->mutex);
3451   return rc;
3452 }
3453 
3454 /*
3455 ** Sleep for a little while.  Return the amount of time slept.
3456 */
3457 int sqlite3_sleep(int ms){
3458   sqlite3_vfs *pVfs;
3459   int rc;
3460   pVfs = sqlite3_vfs_find(0);
3461   if( pVfs==0 ) return 0;
3462 
3463   /* This function works in milliseconds, but the underlying OsSleep()
3464   ** API uses microseconds. Hence the 1000's.
3465   */
3466   rc = (sqlite3OsSleep(pVfs, 1000*ms)/1000);
3467   return rc;
3468 }
3469 
3470 /*
3471 ** Enable or disable the extended result codes.
3472 */
3473 int sqlite3_extended_result_codes(sqlite3 *db, int onoff){
3474 #ifdef SQLITE_ENABLE_API_ARMOR
3475   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3476 #endif
3477   sqlite3_mutex_enter(db->mutex);
3478   db->errMask = onoff ? 0xffffffff : 0xff;
3479   sqlite3_mutex_leave(db->mutex);
3480   return SQLITE_OK;
3481 }
3482 
3483 /*
3484 ** Invoke the xFileControl method on a particular database.
3485 */
3486 int sqlite3_file_control(sqlite3 *db, const char *zDbName, int op, void *pArg){
3487   int rc = SQLITE_ERROR;
3488   Btree *pBtree;
3489 
3490 #ifdef SQLITE_ENABLE_API_ARMOR
3491   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3492 #endif
3493   sqlite3_mutex_enter(db->mutex);
3494   pBtree = sqlite3DbNameToBtree(db, zDbName);
3495   if( pBtree ){
3496     Pager *pPager;
3497     sqlite3_file *fd;
3498     sqlite3BtreeEnter(pBtree);
3499     pPager = sqlite3BtreePager(pBtree);
3500     assert( pPager!=0 );
3501     fd = sqlite3PagerFile(pPager);
3502     assert( fd!=0 );
3503     if( op==SQLITE_FCNTL_FILE_POINTER ){
3504       *(sqlite3_file**)pArg = fd;
3505       rc = SQLITE_OK;
3506     }else if( op==SQLITE_FCNTL_VFS_POINTER ){
3507       *(sqlite3_vfs**)pArg = sqlite3PagerVfs(pPager);
3508       rc = SQLITE_OK;
3509     }else if( op==SQLITE_FCNTL_JOURNAL_POINTER ){
3510       *(sqlite3_file**)pArg = sqlite3PagerJrnlFile(pPager);
3511       rc = SQLITE_OK;
3512     }else if( fd->pMethods ){
3513       rc = sqlite3OsFileControl(fd, op, pArg);
3514     }else{
3515       rc = SQLITE_NOTFOUND;
3516     }
3517     sqlite3BtreeLeave(pBtree);
3518   }
3519   sqlite3_mutex_leave(db->mutex);
3520   return rc;
3521 }
3522 
3523 /*
3524 ** Interface to the testing logic.
3525 */
3526 int sqlite3_test_control(int op, ...){
3527   int rc = 0;
3528 #ifdef SQLITE_OMIT_BUILTIN_TEST
3529   UNUSED_PARAMETER(op);
3530 #else
3531   va_list ap;
3532   va_start(ap, op);
3533   switch( op ){
3534 
3535     /*
3536     ** Save the current state of the PRNG.
3537     */
3538     case SQLITE_TESTCTRL_PRNG_SAVE: {
3539       sqlite3PrngSaveState();
3540       break;
3541     }
3542 
3543     /*
3544     ** Restore the state of the PRNG to the last state saved using
3545     ** PRNG_SAVE.  If PRNG_SAVE has never before been called, then
3546     ** this verb acts like PRNG_RESET.
3547     */
3548     case SQLITE_TESTCTRL_PRNG_RESTORE: {
3549       sqlite3PrngRestoreState();
3550       break;
3551     }
3552 
3553     /*
3554     ** Reset the PRNG back to its uninitialized state.  The next call
3555     ** to sqlite3_randomness() will reseed the PRNG using a single call
3556     ** to the xRandomness method of the default VFS.
3557     */
3558     case SQLITE_TESTCTRL_PRNG_RESET: {
3559       sqlite3_randomness(0,0);
3560       break;
3561     }
3562 
3563     /*
3564     **  sqlite3_test_control(BITVEC_TEST, size, program)
3565     **
3566     ** Run a test against a Bitvec object of size.  The program argument
3567     ** is an array of integers that defines the test.  Return -1 on a
3568     ** memory allocation error, 0 on success, or non-zero for an error.
3569     ** See the sqlite3BitvecBuiltinTest() for additional information.
3570     */
3571     case SQLITE_TESTCTRL_BITVEC_TEST: {
3572       int sz = va_arg(ap, int);
3573       int *aProg = va_arg(ap, int*);
3574       rc = sqlite3BitvecBuiltinTest(sz, aProg);
3575       break;
3576     }
3577 
3578     /*
3579     **  sqlite3_test_control(FAULT_INSTALL, xCallback)
3580     **
3581     ** Arrange to invoke xCallback() whenever sqlite3FaultSim() is called,
3582     ** if xCallback is not NULL.
3583     **
3584     ** As a test of the fault simulator mechanism itself, sqlite3FaultSim(0)
3585     ** is called immediately after installing the new callback and the return
3586     ** value from sqlite3FaultSim(0) becomes the return from
3587     ** sqlite3_test_control().
3588     */
3589     case SQLITE_TESTCTRL_FAULT_INSTALL: {
3590       /* MSVC is picky about pulling func ptrs from va lists.
3591       ** http://support.microsoft.com/kb/47961
3592       ** sqlite3GlobalConfig.xTestCallback = va_arg(ap, int(*)(int));
3593       */
3594       typedef int(*TESTCALLBACKFUNC_t)(int);
3595       sqlite3GlobalConfig.xTestCallback = va_arg(ap, TESTCALLBACKFUNC_t);
3596       rc = sqlite3FaultSim(0);
3597       break;
3598     }
3599 
3600     /*
3601     **  sqlite3_test_control(BENIGN_MALLOC_HOOKS, xBegin, xEnd)
3602     **
3603     ** Register hooks to call to indicate which malloc() failures
3604     ** are benign.
3605     */
3606     case SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS: {
3607       typedef void (*void_function)(void);
3608       void_function xBenignBegin;
3609       void_function xBenignEnd;
3610       xBenignBegin = va_arg(ap, void_function);
3611       xBenignEnd = va_arg(ap, void_function);
3612       sqlite3BenignMallocHooks(xBenignBegin, xBenignEnd);
3613       break;
3614     }
3615 
3616     /*
3617     **  sqlite3_test_control(SQLITE_TESTCTRL_PENDING_BYTE, unsigned int X)
3618     **
3619     ** Set the PENDING byte to the value in the argument, if X>0.
3620     ** Make no changes if X==0.  Return the value of the pending byte
3621     ** as it existing before this routine was called.
3622     **
3623     ** IMPORTANT:  Changing the PENDING byte from 0x40000000 results in
3624     ** an incompatible database file format.  Changing the PENDING byte
3625     ** while any database connection is open results in undefined and
3626     ** deleterious behavior.
3627     */
3628     case SQLITE_TESTCTRL_PENDING_BYTE: {
3629       rc = PENDING_BYTE;
3630 #ifndef SQLITE_OMIT_WSD
3631       {
3632         unsigned int newVal = va_arg(ap, unsigned int);
3633         if( newVal ) sqlite3PendingByte = newVal;
3634       }
3635 #endif
3636       break;
3637     }
3638 
3639     /*
3640     **  sqlite3_test_control(SQLITE_TESTCTRL_ASSERT, int X)
3641     **
3642     ** This action provides a run-time test to see whether or not
3643     ** assert() was enabled at compile-time.  If X is true and assert()
3644     ** is enabled, then the return value is true.  If X is true and
3645     ** assert() is disabled, then the return value is zero.  If X is
3646     ** false and assert() is enabled, then the assertion fires and the
3647     ** process aborts.  If X is false and assert() is disabled, then the
3648     ** return value is zero.
3649     */
3650     case SQLITE_TESTCTRL_ASSERT: {
3651       volatile int x = 0;
3652       assert( /*side-effects-ok*/ (x = va_arg(ap,int))!=0 );
3653       rc = x;
3654       break;
3655     }
3656 
3657 
3658     /*
3659     **  sqlite3_test_control(SQLITE_TESTCTRL_ALWAYS, int X)
3660     **
3661     ** This action provides a run-time test to see how the ALWAYS and
3662     ** NEVER macros were defined at compile-time.
3663     **
3664     ** The return value is ALWAYS(X).
3665     **
3666     ** The recommended test is X==2.  If the return value is 2, that means
3667     ** ALWAYS() and NEVER() are both no-op pass-through macros, which is the
3668     ** default setting.  If the return value is 1, then ALWAYS() is either
3669     ** hard-coded to true or else it asserts if its argument is false.
3670     ** The first behavior (hard-coded to true) is the case if
3671     ** SQLITE_TESTCTRL_ASSERT shows that assert() is disabled and the second
3672     ** behavior (assert if the argument to ALWAYS() is false) is the case if
3673     ** SQLITE_TESTCTRL_ASSERT shows that assert() is enabled.
3674     **
3675     ** The run-time test procedure might look something like this:
3676     **
3677     **    if( sqlite3_test_control(SQLITE_TESTCTRL_ALWAYS, 2)==2 ){
3678     **      // ALWAYS() and NEVER() are no-op pass-through macros
3679     **    }else if( sqlite3_test_control(SQLITE_TESTCTRL_ASSERT, 1) ){
3680     **      // ALWAYS(x) asserts that x is true. NEVER(x) asserts x is false.
3681     **    }else{
3682     **      // ALWAYS(x) is a constant 1.  NEVER(x) is a constant 0.
3683     **    }
3684     */
3685     case SQLITE_TESTCTRL_ALWAYS: {
3686       int x = va_arg(ap,int);
3687       rc = ALWAYS(x);
3688       break;
3689     }
3690 
3691     /*
3692     **   sqlite3_test_control(SQLITE_TESTCTRL_BYTEORDER);
3693     **
3694     ** The integer returned reveals the byte-order of the computer on which
3695     ** SQLite is running:
3696     **
3697     **       1     big-endian,    determined at run-time
3698     **      10     little-endian, determined at run-time
3699     **  432101     big-endian,    determined at compile-time
3700     **  123410     little-endian, determined at compile-time
3701     */
3702     case SQLITE_TESTCTRL_BYTEORDER: {
3703       rc = SQLITE_BYTEORDER*100 + SQLITE_LITTLEENDIAN*10 + SQLITE_BIGENDIAN;
3704       break;
3705     }
3706 
3707     /*   sqlite3_test_control(SQLITE_TESTCTRL_RESERVE, sqlite3 *db, int N)
3708     **
3709     ** Set the nReserve size to N for the main database on the database
3710     ** connection db.
3711     */
3712     case SQLITE_TESTCTRL_RESERVE: {
3713       sqlite3 *db = va_arg(ap, sqlite3*);
3714       int x = va_arg(ap,int);
3715       sqlite3_mutex_enter(db->mutex);
3716       sqlite3BtreeSetPageSize(db->aDb[0].pBt, 0, x, 0);
3717       sqlite3_mutex_leave(db->mutex);
3718       break;
3719     }
3720 
3721     /*  sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS, sqlite3 *db, int N)
3722     **
3723     ** Enable or disable various optimizations for testing purposes.  The
3724     ** argument N is a bitmask of optimizations to be disabled.  For normal
3725     ** operation N should be 0.  The idea is that a test program (like the
3726     ** SQL Logic Test or SLT test module) can run the same SQL multiple times
3727     ** with various optimizations disabled to verify that the same answer
3728     ** is obtained in every case.
3729     */
3730     case SQLITE_TESTCTRL_OPTIMIZATIONS: {
3731       sqlite3 *db = va_arg(ap, sqlite3*);
3732       db->dbOptFlags = (u16)(va_arg(ap, int) & 0xffff);
3733       break;
3734     }
3735 
3736 #ifdef SQLITE_N_KEYWORD
3737     /* sqlite3_test_control(SQLITE_TESTCTRL_ISKEYWORD, const char *zWord)
3738     **
3739     ** If zWord is a keyword recognized by the parser, then return the
3740     ** number of keywords.  Or if zWord is not a keyword, return 0.
3741     **
3742     ** This test feature is only available in the amalgamation since
3743     ** the SQLITE_N_KEYWORD macro is not defined in this file if SQLite
3744     ** is built using separate source files.
3745     */
3746     case SQLITE_TESTCTRL_ISKEYWORD: {
3747       const char *zWord = va_arg(ap, const char*);
3748       int n = sqlite3Strlen30(zWord);
3749       rc = (sqlite3KeywordCode((u8*)zWord, n)!=TK_ID) ? SQLITE_N_KEYWORD : 0;
3750       break;
3751     }
3752 #endif
3753 
3754     /* sqlite3_test_control(SQLITE_TESTCTRL_SCRATCHMALLOC, sz, &pNew, pFree);
3755     **
3756     ** Pass pFree into sqlite3ScratchFree().
3757     ** If sz>0 then allocate a scratch buffer into pNew.
3758     */
3759     case SQLITE_TESTCTRL_SCRATCHMALLOC: {
3760       void *pFree, **ppNew;
3761       int sz;
3762       sz = va_arg(ap, int);
3763       ppNew = va_arg(ap, void**);
3764       pFree = va_arg(ap, void*);
3765       if( sz ) *ppNew = sqlite3ScratchMalloc(sz);
3766       sqlite3ScratchFree(pFree);
3767       break;
3768     }
3769 
3770     /*   sqlite3_test_control(SQLITE_TESTCTRL_LOCALTIME_FAULT, int onoff);
3771     **
3772     ** If parameter onoff is non-zero, configure the wrappers so that all
3773     ** subsequent calls to localtime() and variants fail. If onoff is zero,
3774     ** undo this setting.
3775     */
3776     case SQLITE_TESTCTRL_LOCALTIME_FAULT: {
3777       sqlite3GlobalConfig.bLocaltimeFault = va_arg(ap, int);
3778       break;
3779     }
3780 
3781     /*   sqlite3_test_control(SQLITE_TESTCTRL_NEVER_CORRUPT, int);
3782     **
3783     ** Set or clear a flag that indicates that the database file is always well-
3784     ** formed and never corrupt.  This flag is clear by default, indicating that
3785     ** database files might have arbitrary corruption.  Setting the flag during
3786     ** testing causes certain assert() statements in the code to be activated
3787     ** that demonstrat invariants on well-formed database files.
3788     */
3789     case SQLITE_TESTCTRL_NEVER_CORRUPT: {
3790       sqlite3GlobalConfig.neverCorrupt = va_arg(ap, int);
3791       break;
3792     }
3793 
3794     /* Set the threshold at which OP_Once counters reset back to zero.
3795     ** By default this is 0x7ffffffe (over 2 billion), but that value is
3796     ** too big to test in a reasonable amount of time, so this control is
3797     ** provided to set a small and easily reachable reset value.
3798     */
3799     case SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD: {
3800       sqlite3GlobalConfig.iOnceResetThreshold = va_arg(ap, int);
3801       break;
3802     }
3803 
3804     /*   sqlite3_test_control(SQLITE_TESTCTRL_VDBE_COVERAGE, xCallback, ptr);
3805     **
3806     ** Set the VDBE coverage callback function to xCallback with context
3807     ** pointer ptr.
3808     */
3809     case SQLITE_TESTCTRL_VDBE_COVERAGE: {
3810 #ifdef SQLITE_VDBE_COVERAGE
3811       typedef void (*branch_callback)(void*,int,u8,u8);
3812       sqlite3GlobalConfig.xVdbeBranch = va_arg(ap,branch_callback);
3813       sqlite3GlobalConfig.pVdbeBranchArg = va_arg(ap,void*);
3814 #endif
3815       break;
3816     }
3817 
3818     /*   sqlite3_test_control(SQLITE_TESTCTRL_SORTER_MMAP, db, nMax); */
3819     case SQLITE_TESTCTRL_SORTER_MMAP: {
3820       sqlite3 *db = va_arg(ap, sqlite3*);
3821       db->nMaxSorterMmap = va_arg(ap, int);
3822       break;
3823     }
3824 
3825     /*   sqlite3_test_control(SQLITE_TESTCTRL_ISINIT);
3826     **
3827     ** Return SQLITE_OK if SQLite has been initialized and SQLITE_ERROR if
3828     ** not.
3829     */
3830     case SQLITE_TESTCTRL_ISINIT: {
3831       if( sqlite3GlobalConfig.isInit==0 ) rc = SQLITE_ERROR;
3832       break;
3833     }
3834 
3835     /*  sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, db, dbName, onOff, tnum);
3836     **
3837     ** This test control is used to create imposter tables.  "db" is a pointer
3838     ** to the database connection.  dbName is the database name (ex: "main" or
3839     ** "temp") which will receive the imposter.  "onOff" turns imposter mode on
3840     ** or off.  "tnum" is the root page of the b-tree to which the imposter
3841     ** table should connect.
3842     **
3843     ** Enable imposter mode only when the schema has already been parsed.  Then
3844     ** run a single CREATE TABLE statement to construct the imposter table in
3845     ** the parsed schema.  Then turn imposter mode back off again.
3846     **
3847     ** If onOff==0 and tnum>0 then reset the schema for all databases, causing
3848     ** the schema to be reparsed the next time it is needed.  This has the
3849     ** effect of erasing all imposter tables.
3850     */
3851     case SQLITE_TESTCTRL_IMPOSTER: {
3852       sqlite3 *db = va_arg(ap, sqlite3*);
3853       sqlite3_mutex_enter(db->mutex);
3854       db->init.iDb = sqlite3FindDbName(db, va_arg(ap,const char*));
3855       db->init.busy = db->init.imposterTable = va_arg(ap,int);
3856       db->init.newTnum = va_arg(ap,int);
3857       if( db->init.busy==0 && db->init.newTnum>0 ){
3858         sqlite3ResetAllSchemasOfConnection(db);
3859       }
3860       sqlite3_mutex_leave(db->mutex);
3861       break;
3862     }
3863   }
3864   va_end(ap);
3865 #endif /* SQLITE_OMIT_BUILTIN_TEST */
3866   return rc;
3867 }
3868 
3869 /*
3870 ** This is a utility routine, useful to VFS implementations, that checks
3871 ** to see if a database file was a URI that contained a specific query
3872 ** parameter, and if so obtains the value of the query parameter.
3873 **
3874 ** The zFilename argument is the filename pointer passed into the xOpen()
3875 ** method of a VFS implementation.  The zParam argument is the name of the
3876 ** query parameter we seek.  This routine returns the value of the zParam
3877 ** parameter if it exists.  If the parameter does not exist, this routine
3878 ** returns a NULL pointer.
3879 */
3880 const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam){
3881   if( zFilename==0 || zParam==0 ) return 0;
3882   zFilename += sqlite3Strlen30(zFilename) + 1;
3883   while( zFilename[0] ){
3884     int x = strcmp(zFilename, zParam);
3885     zFilename += sqlite3Strlen30(zFilename) + 1;
3886     if( x==0 ) return zFilename;
3887     zFilename += sqlite3Strlen30(zFilename) + 1;
3888   }
3889   return 0;
3890 }
3891 
3892 /*
3893 ** Return a boolean value for a query parameter.
3894 */
3895 int sqlite3_uri_boolean(const char *zFilename, const char *zParam, int bDflt){
3896   const char *z = sqlite3_uri_parameter(zFilename, zParam);
3897   bDflt = bDflt!=0;
3898   return z ? sqlite3GetBoolean(z, bDflt) : bDflt;
3899 }
3900 
3901 /*
3902 ** Return a 64-bit integer value for a query parameter.
3903 */
3904 sqlite3_int64 sqlite3_uri_int64(
3905   const char *zFilename,    /* Filename as passed to xOpen */
3906   const char *zParam,       /* URI parameter sought */
3907   sqlite3_int64 bDflt       /* return if parameter is missing */
3908 ){
3909   const char *z = sqlite3_uri_parameter(zFilename, zParam);
3910   sqlite3_int64 v;
3911   if( z && sqlite3DecOrHexToI64(z, &v)==SQLITE_OK ){
3912     bDflt = v;
3913   }
3914   return bDflt;
3915 }
3916 
3917 /*
3918 ** Return the Btree pointer identified by zDbName.  Return NULL if not found.
3919 */
3920 Btree *sqlite3DbNameToBtree(sqlite3 *db, const char *zDbName){
3921   int i;
3922   for(i=0; i<db->nDb; i++){
3923     if( db->aDb[i].pBt
3924      && (zDbName==0 || sqlite3StrICmp(zDbName, db->aDb[i].zDbSName)==0)
3925     ){
3926       return db->aDb[i].pBt;
3927     }
3928   }
3929   return 0;
3930 }
3931 
3932 /*
3933 ** Return the filename of the database associated with a database
3934 ** connection.
3935 */
3936 const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName){
3937   Btree *pBt;
3938 #ifdef SQLITE_ENABLE_API_ARMOR
3939   if( !sqlite3SafetyCheckOk(db) ){
3940     (void)SQLITE_MISUSE_BKPT;
3941     return 0;
3942   }
3943 #endif
3944   pBt = sqlite3DbNameToBtree(db, zDbName);
3945   return pBt ? sqlite3BtreeGetFilename(pBt) : 0;
3946 }
3947 
3948 /*
3949 ** Return 1 if database is read-only or 0 if read/write.  Return -1 if
3950 ** no such database exists.
3951 */
3952 int sqlite3_db_readonly(sqlite3 *db, const char *zDbName){
3953   Btree *pBt;
3954 #ifdef SQLITE_ENABLE_API_ARMOR
3955   if( !sqlite3SafetyCheckOk(db) ){
3956     (void)SQLITE_MISUSE_BKPT;
3957     return -1;
3958   }
3959 #endif
3960   pBt = sqlite3DbNameToBtree(db, zDbName);
3961   return pBt ? sqlite3BtreeIsReadonly(pBt) : -1;
3962 }
3963 
3964 #ifdef SQLITE_ENABLE_SNAPSHOT
3965 /*
3966 ** Obtain a snapshot handle for the snapshot of database zDb currently
3967 ** being read by handle db.
3968 */
3969 int sqlite3_snapshot_get(
3970   sqlite3 *db,
3971   const char *zDb,
3972   sqlite3_snapshot **ppSnapshot
3973 ){
3974   int rc = SQLITE_ERROR;
3975 #ifndef SQLITE_OMIT_WAL
3976   int iDb;
3977 
3978 #ifdef SQLITE_ENABLE_API_ARMOR
3979   if( !sqlite3SafetyCheckOk(db) ){
3980     return SQLITE_MISUSE_BKPT;
3981   }
3982 #endif
3983   sqlite3_mutex_enter(db->mutex);
3984 
3985   iDb = sqlite3FindDbName(db, zDb);
3986   if( iDb==0 || iDb>1 ){
3987     Btree *pBt = db->aDb[iDb].pBt;
3988     if( 0==sqlite3BtreeIsInTrans(pBt) ){
3989       rc = sqlite3BtreeBeginTrans(pBt, 0);
3990       if( rc==SQLITE_OK ){
3991         rc = sqlite3PagerSnapshotGet(sqlite3BtreePager(pBt), ppSnapshot);
3992       }
3993     }
3994   }
3995 
3996   sqlite3_mutex_leave(db->mutex);
3997 #endif   /* SQLITE_OMIT_WAL */
3998   return rc;
3999 }
4000 
4001 /*
4002 ** Open a read-transaction on the snapshot idendified by pSnapshot.
4003 */
4004 int sqlite3_snapshot_open(
4005   sqlite3 *db,
4006   const char *zDb,
4007   sqlite3_snapshot *pSnapshot
4008 ){
4009   int rc = SQLITE_ERROR;
4010 #ifndef SQLITE_OMIT_WAL
4011 
4012 #ifdef SQLITE_ENABLE_API_ARMOR
4013   if( !sqlite3SafetyCheckOk(db) ){
4014     return SQLITE_MISUSE_BKPT;
4015   }
4016 #endif
4017   sqlite3_mutex_enter(db->mutex);
4018   if( db->autoCommit==0 ){
4019     int iDb;
4020     iDb = sqlite3FindDbName(db, zDb);
4021     if( iDb==0 || iDb>1 ){
4022       Btree *pBt = db->aDb[iDb].pBt;
4023       if( 0==sqlite3BtreeIsInReadTrans(pBt) ){
4024         rc = sqlite3PagerSnapshotOpen(sqlite3BtreePager(pBt), pSnapshot);
4025         if( rc==SQLITE_OK ){
4026           rc = sqlite3BtreeBeginTrans(pBt, 0);
4027           sqlite3PagerSnapshotOpen(sqlite3BtreePager(pBt), 0);
4028         }
4029       }
4030     }
4031   }
4032 
4033   sqlite3_mutex_leave(db->mutex);
4034 #endif   /* SQLITE_OMIT_WAL */
4035   return rc;
4036 }
4037 
4038 /*
4039 ** Free a snapshot handle obtained from sqlite3_snapshot_get().
4040 */
4041 void sqlite3_snapshot_free(sqlite3_snapshot *pSnapshot){
4042   sqlite3_free(pSnapshot);
4043 }
4044 #endif /* SQLITE_ENABLE_SNAPSHOT */
4045