xref: /sqlite-3.40.0/src/main.c (revision fb32c44e)
1 /*
2 ** 2001 September 15
3 **
4 ** The author disclaims copyright to this source code.  In place of
5 ** a legal notice, here is a blessing:
6 **
7 **    May you do good and not evil.
8 **    May you find forgiveness for yourself and forgive others.
9 **    May you share freely, never taking more than you give.
10 **
11 *************************************************************************
12 ** Main file for the SQLite library.  The routines in this file
13 ** implement the programmer interface to the library.  Routines in
14 ** other files are for internal use by SQLite and should not be
15 ** accessed by users of the library.
16 */
17 #include "sqliteInt.h"
18 
19 #ifdef SQLITE_ENABLE_FTS3
20 # include "fts3.h"
21 #endif
22 #ifdef SQLITE_ENABLE_RTREE
23 # include "rtree.h"
24 #endif
25 #if defined(SQLITE_ENABLE_ICU) || defined(SQLITE_ENABLE_ICU_COLLATIONS)
26 # include "sqliteicu.h"
27 #endif
28 #ifdef SQLITE_ENABLE_JSON1
29 int sqlite3Json1Init(sqlite3*);
30 #endif
31 #ifdef SQLITE_ENABLE_STMTVTAB
32 int sqlite3StmtVtabInit(sqlite3*);
33 #endif
34 #ifdef SQLITE_ENABLE_FTS5
35 int sqlite3Fts5Init(sqlite3*);
36 #endif
37 
38 #ifndef SQLITE_AMALGAMATION
39 /* IMPLEMENTATION-OF: R-46656-45156 The sqlite3_version[] string constant
40 ** contains the text of SQLITE_VERSION macro.
41 */
42 const char sqlite3_version[] = SQLITE_VERSION;
43 #endif
44 
45 /* IMPLEMENTATION-OF: R-53536-42575 The sqlite3_libversion() function returns
46 ** a pointer to the to the sqlite3_version[] string constant.
47 */
48 const char *sqlite3_libversion(void){ return sqlite3_version; }
49 
50 /* IMPLEMENTATION-OF: R-25063-23286 The sqlite3_sourceid() function returns a
51 ** pointer to a string constant whose value is the same as the
52 ** SQLITE_SOURCE_ID C preprocessor macro. Except if SQLite is built using
53 ** an edited copy of the amalgamation, then the last four characters of
54 ** the hash might be different from SQLITE_SOURCE_ID.
55 */
56 const char *sqlite3_sourceid(void){ return SQLITE_SOURCE_ID; }
57 
58 /* IMPLEMENTATION-OF: R-35210-63508 The sqlite3_libversion_number() function
59 ** returns an integer equal to SQLITE_VERSION_NUMBER.
60 */
61 int sqlite3_libversion_number(void){ return SQLITE_VERSION_NUMBER; }
62 
63 /* IMPLEMENTATION-OF: R-20790-14025 The sqlite3_threadsafe() function returns
64 ** zero if and only if SQLite was compiled with mutexing code omitted due to
65 ** the SQLITE_THREADSAFE compile-time option being set to 0.
66 */
67 int sqlite3_threadsafe(void){ return SQLITE_THREADSAFE; }
68 
69 /*
70 ** When compiling the test fixture or with debugging enabled (on Win32),
71 ** this variable being set to non-zero will cause OSTRACE macros to emit
72 ** extra diagnostic information.
73 */
74 #ifdef SQLITE_HAVE_OS_TRACE
75 # ifndef SQLITE_DEBUG_OS_TRACE
76 #   define SQLITE_DEBUG_OS_TRACE 0
77 # endif
78   int sqlite3OSTrace = SQLITE_DEBUG_OS_TRACE;
79 #endif
80 
81 #if !defined(SQLITE_OMIT_TRACE) && defined(SQLITE_ENABLE_IOTRACE)
82 /*
83 ** If the following function pointer is not NULL and if
84 ** SQLITE_ENABLE_IOTRACE is enabled, then messages describing
85 ** I/O active are written using this function.  These messages
86 ** are intended for debugging activity only.
87 */
88 SQLITE_API void (SQLITE_CDECL *sqlite3IoTrace)(const char*, ...) = 0;
89 #endif
90 
91 /*
92 ** If the following global variable points to a string which is the
93 ** name of a directory, then that directory will be used to store
94 ** temporary files.
95 **
96 ** See also the "PRAGMA temp_store_directory" SQL command.
97 */
98 char *sqlite3_temp_directory = 0;
99 
100 /*
101 ** If the following global variable points to a string which is the
102 ** name of a directory, then that directory will be used to store
103 ** all database files specified with a relative pathname.
104 **
105 ** See also the "PRAGMA data_store_directory" SQL command.
106 */
107 char *sqlite3_data_directory = 0;
108 
109 /*
110 ** Initialize SQLite.
111 **
112 ** This routine must be called to initialize the memory allocation,
113 ** VFS, and mutex subsystems prior to doing any serious work with
114 ** SQLite.  But as long as you do not compile with SQLITE_OMIT_AUTOINIT
115 ** this routine will be called automatically by key routines such as
116 ** sqlite3_open().
117 **
118 ** This routine is a no-op except on its very first call for the process,
119 ** or for the first call after a call to sqlite3_shutdown.
120 **
121 ** The first thread to call this routine runs the initialization to
122 ** completion.  If subsequent threads call this routine before the first
123 ** thread has finished the initialization process, then the subsequent
124 ** threads must block until the first thread finishes with the initialization.
125 **
126 ** The first thread might call this routine recursively.  Recursive
127 ** calls to this routine should not block, of course.  Otherwise the
128 ** initialization process would never complete.
129 **
130 ** Let X be the first thread to enter this routine.  Let Y be some other
131 ** thread.  Then while the initial invocation of this routine by X is
132 ** incomplete, it is required that:
133 **
134 **    *  Calls to this routine from Y must block until the outer-most
135 **       call by X completes.
136 **
137 **    *  Recursive calls to this routine from thread X return immediately
138 **       without blocking.
139 */
140 int sqlite3_initialize(void){
141   MUTEX_LOGIC( sqlite3_mutex *pMaster; )       /* The main static mutex */
142   int rc;                                      /* Result code */
143 #ifdef SQLITE_EXTRA_INIT
144   int bRunExtraInit = 0;                       /* Extra initialization needed */
145 #endif
146 
147 #ifdef SQLITE_OMIT_WSD
148   rc = sqlite3_wsd_init(4096, 24);
149   if( rc!=SQLITE_OK ){
150     return rc;
151   }
152 #endif
153 
154   /* If the following assert() fails on some obscure processor/compiler
155   ** combination, the work-around is to set the correct pointer
156   ** size at compile-time using -DSQLITE_PTRSIZE=n compile-time option */
157   assert( SQLITE_PTRSIZE==sizeof(char*) );
158 
159   /* If SQLite is already completely initialized, then this call
160   ** to sqlite3_initialize() should be a no-op.  But the initialization
161   ** must be complete.  So isInit must not be set until the very end
162   ** of this routine.
163   */
164   if( sqlite3GlobalConfig.isInit ) return SQLITE_OK;
165 
166   /* Make sure the mutex subsystem is initialized.  If unable to
167   ** initialize the mutex subsystem, return early with the error.
168   ** If the system is so sick that we are unable to allocate a mutex,
169   ** there is not much SQLite is going to be able to do.
170   **
171   ** The mutex subsystem must take care of serializing its own
172   ** initialization.
173   */
174   rc = sqlite3MutexInit();
175   if( rc ) return rc;
176 
177   /* Initialize the malloc() system and the recursive pInitMutex mutex.
178   ** This operation is protected by the STATIC_MASTER mutex.  Note that
179   ** MutexAlloc() is called for a static mutex prior to initializing the
180   ** malloc subsystem - this implies that the allocation of a static
181   ** mutex must not require support from the malloc subsystem.
182   */
183   MUTEX_LOGIC( pMaster = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER); )
184   sqlite3_mutex_enter(pMaster);
185   sqlite3GlobalConfig.isMutexInit = 1;
186   if( !sqlite3GlobalConfig.isMallocInit ){
187     rc = sqlite3MallocInit();
188   }
189   if( rc==SQLITE_OK ){
190     sqlite3GlobalConfig.isMallocInit = 1;
191     if( !sqlite3GlobalConfig.pInitMutex ){
192       sqlite3GlobalConfig.pInitMutex =
193            sqlite3MutexAlloc(SQLITE_MUTEX_RECURSIVE);
194       if( sqlite3GlobalConfig.bCoreMutex && !sqlite3GlobalConfig.pInitMutex ){
195         rc = SQLITE_NOMEM_BKPT;
196       }
197     }
198   }
199   if( rc==SQLITE_OK ){
200     sqlite3GlobalConfig.nRefInitMutex++;
201   }
202   sqlite3_mutex_leave(pMaster);
203 
204   /* If rc is not SQLITE_OK at this point, then either the malloc
205   ** subsystem could not be initialized or the system failed to allocate
206   ** the pInitMutex mutex. Return an error in either case.  */
207   if( rc!=SQLITE_OK ){
208     return rc;
209   }
210 
211   /* Do the rest of the initialization under the recursive mutex so
212   ** that we will be able to handle recursive calls into
213   ** sqlite3_initialize().  The recursive calls normally come through
214   ** sqlite3_os_init() when it invokes sqlite3_vfs_register(), but other
215   ** recursive calls might also be possible.
216   **
217   ** IMPLEMENTATION-OF: R-00140-37445 SQLite automatically serializes calls
218   ** to the xInit method, so the xInit method need not be threadsafe.
219   **
220   ** The following mutex is what serializes access to the appdef pcache xInit
221   ** methods.  The sqlite3_pcache_methods.xInit() all is embedded in the
222   ** call to sqlite3PcacheInitialize().
223   */
224   sqlite3_mutex_enter(sqlite3GlobalConfig.pInitMutex);
225   if( sqlite3GlobalConfig.isInit==0 && sqlite3GlobalConfig.inProgress==0 ){
226     sqlite3GlobalConfig.inProgress = 1;
227 #ifdef SQLITE_ENABLE_SQLLOG
228     {
229       extern void sqlite3_init_sqllog(void);
230       sqlite3_init_sqllog();
231     }
232 #endif
233     memset(&sqlite3BuiltinFunctions, 0, sizeof(sqlite3BuiltinFunctions));
234     sqlite3RegisterBuiltinFunctions();
235     if( sqlite3GlobalConfig.isPCacheInit==0 ){
236       rc = sqlite3PcacheInitialize();
237     }
238     if( rc==SQLITE_OK ){
239       sqlite3GlobalConfig.isPCacheInit = 1;
240       rc = sqlite3OsInit();
241     }
242 #ifdef SQLITE_ENABLE_DESERIALIZE
243     if( rc==SQLITE_OK ){
244       rc = sqlite3MemdbInit();
245     }
246 #endif
247     if( rc==SQLITE_OK ){
248       sqlite3PCacheBufferSetup( sqlite3GlobalConfig.pPage,
249           sqlite3GlobalConfig.szPage, sqlite3GlobalConfig.nPage);
250       sqlite3GlobalConfig.isInit = 1;
251 #ifdef SQLITE_EXTRA_INIT
252       bRunExtraInit = 1;
253 #endif
254     }
255     sqlite3GlobalConfig.inProgress = 0;
256   }
257   sqlite3_mutex_leave(sqlite3GlobalConfig.pInitMutex);
258 
259   /* Go back under the static mutex and clean up the recursive
260   ** mutex to prevent a resource leak.
261   */
262   sqlite3_mutex_enter(pMaster);
263   sqlite3GlobalConfig.nRefInitMutex--;
264   if( sqlite3GlobalConfig.nRefInitMutex<=0 ){
265     assert( sqlite3GlobalConfig.nRefInitMutex==0 );
266     sqlite3_mutex_free(sqlite3GlobalConfig.pInitMutex);
267     sqlite3GlobalConfig.pInitMutex = 0;
268   }
269   sqlite3_mutex_leave(pMaster);
270 
271   /* The following is just a sanity check to make sure SQLite has
272   ** been compiled correctly.  It is important to run this code, but
273   ** we don't want to run it too often and soak up CPU cycles for no
274   ** reason.  So we run it once during initialization.
275   */
276 #ifndef NDEBUG
277 #ifndef SQLITE_OMIT_FLOATING_POINT
278   /* This section of code's only "output" is via assert() statements. */
279   if( rc==SQLITE_OK ){
280     u64 x = (((u64)1)<<63)-1;
281     double y;
282     assert(sizeof(x)==8);
283     assert(sizeof(x)==sizeof(y));
284     memcpy(&y, &x, 8);
285     assert( sqlite3IsNaN(y) );
286   }
287 #endif
288 #endif
289 
290   /* Do extra initialization steps requested by the SQLITE_EXTRA_INIT
291   ** compile-time option.
292   */
293 #ifdef SQLITE_EXTRA_INIT
294   if( bRunExtraInit ){
295     int SQLITE_EXTRA_INIT(const char*);
296     rc = SQLITE_EXTRA_INIT(0);
297   }
298 #endif
299 
300   return rc;
301 }
302 
303 /*
304 ** Undo the effects of sqlite3_initialize().  Must not be called while
305 ** there are outstanding database connections or memory allocations or
306 ** while any part of SQLite is otherwise in use in any thread.  This
307 ** routine is not threadsafe.  But it is safe to invoke this routine
308 ** on when SQLite is already shut down.  If SQLite is already shut down
309 ** when this routine is invoked, then this routine is a harmless no-op.
310 */
311 int sqlite3_shutdown(void){
312 #ifdef SQLITE_OMIT_WSD
313   int rc = sqlite3_wsd_init(4096, 24);
314   if( rc!=SQLITE_OK ){
315     return rc;
316   }
317 #endif
318 
319   if( sqlite3GlobalConfig.isInit ){
320 #ifdef SQLITE_EXTRA_SHUTDOWN
321     void SQLITE_EXTRA_SHUTDOWN(void);
322     SQLITE_EXTRA_SHUTDOWN();
323 #endif
324     sqlite3_os_end();
325     sqlite3_reset_auto_extension();
326     sqlite3GlobalConfig.isInit = 0;
327   }
328   if( sqlite3GlobalConfig.isPCacheInit ){
329     sqlite3PcacheShutdown();
330     sqlite3GlobalConfig.isPCacheInit = 0;
331   }
332   if( sqlite3GlobalConfig.isMallocInit ){
333     sqlite3MallocEnd();
334     sqlite3GlobalConfig.isMallocInit = 0;
335 
336 #ifndef SQLITE_OMIT_SHUTDOWN_DIRECTORIES
337     /* The heap subsystem has now been shutdown and these values are supposed
338     ** to be NULL or point to memory that was obtained from sqlite3_malloc(),
339     ** which would rely on that heap subsystem; therefore, make sure these
340     ** values cannot refer to heap memory that was just invalidated when the
341     ** heap subsystem was shutdown.  This is only done if the current call to
342     ** this function resulted in the heap subsystem actually being shutdown.
343     */
344     sqlite3_data_directory = 0;
345     sqlite3_temp_directory = 0;
346 #endif
347   }
348   if( sqlite3GlobalConfig.isMutexInit ){
349     sqlite3MutexEnd();
350     sqlite3GlobalConfig.isMutexInit = 0;
351   }
352 
353   return SQLITE_OK;
354 }
355 
356 /*
357 ** This API allows applications to modify the global configuration of
358 ** the SQLite library at run-time.
359 **
360 ** This routine should only be called when there are no outstanding
361 ** database connections or memory allocations.  This routine is not
362 ** threadsafe.  Failure to heed these warnings can lead to unpredictable
363 ** behavior.
364 */
365 int sqlite3_config(int op, ...){
366   va_list ap;
367   int rc = SQLITE_OK;
368 
369   /* sqlite3_config() shall return SQLITE_MISUSE if it is invoked while
370   ** the SQLite library is in use. */
371   if( sqlite3GlobalConfig.isInit ) return SQLITE_MISUSE_BKPT;
372 
373   va_start(ap, op);
374   switch( op ){
375 
376     /* Mutex configuration options are only available in a threadsafe
377     ** compile.
378     */
379 #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0  /* IMP: R-54466-46756 */
380     case SQLITE_CONFIG_SINGLETHREAD: {
381       /* EVIDENCE-OF: R-02748-19096 This option sets the threading mode to
382       ** Single-thread. */
383       sqlite3GlobalConfig.bCoreMutex = 0;  /* Disable mutex on core */
384       sqlite3GlobalConfig.bFullMutex = 0;  /* Disable mutex on connections */
385       break;
386     }
387 #endif
388 #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-20520-54086 */
389     case SQLITE_CONFIG_MULTITHREAD: {
390       /* EVIDENCE-OF: R-14374-42468 This option sets the threading mode to
391       ** Multi-thread. */
392       sqlite3GlobalConfig.bCoreMutex = 1;  /* Enable mutex on core */
393       sqlite3GlobalConfig.bFullMutex = 0;  /* Disable mutex on connections */
394       break;
395     }
396 #endif
397 #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-59593-21810 */
398     case SQLITE_CONFIG_SERIALIZED: {
399       /* EVIDENCE-OF: R-41220-51800 This option sets the threading mode to
400       ** Serialized. */
401       sqlite3GlobalConfig.bCoreMutex = 1;  /* Enable mutex on core */
402       sqlite3GlobalConfig.bFullMutex = 1;  /* Enable mutex on connections */
403       break;
404     }
405 #endif
406 #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-63666-48755 */
407     case SQLITE_CONFIG_MUTEX: {
408       /* Specify an alternative mutex implementation */
409       sqlite3GlobalConfig.mutex = *va_arg(ap, sqlite3_mutex_methods*);
410       break;
411     }
412 #endif
413 #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-14450-37597 */
414     case SQLITE_CONFIG_GETMUTEX: {
415       /* Retrieve the current mutex implementation */
416       *va_arg(ap, sqlite3_mutex_methods*) = sqlite3GlobalConfig.mutex;
417       break;
418     }
419 #endif
420 
421     case SQLITE_CONFIG_MALLOC: {
422       /* EVIDENCE-OF: R-55594-21030 The SQLITE_CONFIG_MALLOC option takes a
423       ** single argument which is a pointer to an instance of the
424       ** sqlite3_mem_methods structure. The argument specifies alternative
425       ** low-level memory allocation routines to be used in place of the memory
426       ** allocation routines built into SQLite. */
427       sqlite3GlobalConfig.m = *va_arg(ap, sqlite3_mem_methods*);
428       break;
429     }
430     case SQLITE_CONFIG_GETMALLOC: {
431       /* EVIDENCE-OF: R-51213-46414 The SQLITE_CONFIG_GETMALLOC option takes a
432       ** single argument which is a pointer to an instance of the
433       ** sqlite3_mem_methods structure. The sqlite3_mem_methods structure is
434       ** filled with the currently defined memory allocation routines. */
435       if( sqlite3GlobalConfig.m.xMalloc==0 ) sqlite3MemSetDefault();
436       *va_arg(ap, sqlite3_mem_methods*) = sqlite3GlobalConfig.m;
437       break;
438     }
439     case SQLITE_CONFIG_MEMSTATUS: {
440       /* EVIDENCE-OF: R-61275-35157 The SQLITE_CONFIG_MEMSTATUS option takes
441       ** single argument of type int, interpreted as a boolean, which enables
442       ** or disables the collection of memory allocation statistics. */
443       sqlite3GlobalConfig.bMemstat = va_arg(ap, int);
444       break;
445     }
446     case SQLITE_CONFIG_SMALL_MALLOC: {
447       sqlite3GlobalConfig.bSmallMalloc = va_arg(ap, int);
448       break;
449     }
450     case SQLITE_CONFIG_PAGECACHE: {
451       /* EVIDENCE-OF: R-18761-36601 There are three arguments to
452       ** SQLITE_CONFIG_PAGECACHE: A pointer to 8-byte aligned memory (pMem),
453       ** the size of each page cache line (sz), and the number of cache lines
454       ** (N). */
455       sqlite3GlobalConfig.pPage = va_arg(ap, void*);
456       sqlite3GlobalConfig.szPage = va_arg(ap, int);
457       sqlite3GlobalConfig.nPage = va_arg(ap, int);
458       break;
459     }
460     case SQLITE_CONFIG_PCACHE_HDRSZ: {
461       /* EVIDENCE-OF: R-39100-27317 The SQLITE_CONFIG_PCACHE_HDRSZ option takes
462       ** a single parameter which is a pointer to an integer and writes into
463       ** that integer the number of extra bytes per page required for each page
464       ** in SQLITE_CONFIG_PAGECACHE. */
465       *va_arg(ap, int*) =
466           sqlite3HeaderSizeBtree() +
467           sqlite3HeaderSizePcache() +
468           sqlite3HeaderSizePcache1();
469       break;
470     }
471 
472     case SQLITE_CONFIG_PCACHE: {
473       /* no-op */
474       break;
475     }
476     case SQLITE_CONFIG_GETPCACHE: {
477       /* now an error */
478       rc = SQLITE_ERROR;
479       break;
480     }
481 
482     case SQLITE_CONFIG_PCACHE2: {
483       /* EVIDENCE-OF: R-63325-48378 The SQLITE_CONFIG_PCACHE2 option takes a
484       ** single argument which is a pointer to an sqlite3_pcache_methods2
485       ** object. This object specifies the interface to a custom page cache
486       ** implementation. */
487       sqlite3GlobalConfig.pcache2 = *va_arg(ap, sqlite3_pcache_methods2*);
488       break;
489     }
490     case SQLITE_CONFIG_GETPCACHE2: {
491       /* EVIDENCE-OF: R-22035-46182 The SQLITE_CONFIG_GETPCACHE2 option takes a
492       ** single argument which is a pointer to an sqlite3_pcache_methods2
493       ** object. SQLite copies of the current page cache implementation into
494       ** that object. */
495       if( sqlite3GlobalConfig.pcache2.xInit==0 ){
496         sqlite3PCacheSetDefault();
497       }
498       *va_arg(ap, sqlite3_pcache_methods2*) = sqlite3GlobalConfig.pcache2;
499       break;
500     }
501 
502 /* EVIDENCE-OF: R-06626-12911 The SQLITE_CONFIG_HEAP option is only
503 ** available if SQLite is compiled with either SQLITE_ENABLE_MEMSYS3 or
504 ** SQLITE_ENABLE_MEMSYS5 and returns SQLITE_ERROR if invoked otherwise. */
505 #if defined(SQLITE_ENABLE_MEMSYS3) || defined(SQLITE_ENABLE_MEMSYS5)
506     case SQLITE_CONFIG_HEAP: {
507       /* EVIDENCE-OF: R-19854-42126 There are three arguments to
508       ** SQLITE_CONFIG_HEAP: An 8-byte aligned pointer to the memory, the
509       ** number of bytes in the memory buffer, and the minimum allocation size.
510       */
511       sqlite3GlobalConfig.pHeap = va_arg(ap, void*);
512       sqlite3GlobalConfig.nHeap = va_arg(ap, int);
513       sqlite3GlobalConfig.mnReq = va_arg(ap, int);
514 
515       if( sqlite3GlobalConfig.mnReq<1 ){
516         sqlite3GlobalConfig.mnReq = 1;
517       }else if( sqlite3GlobalConfig.mnReq>(1<<12) ){
518         /* cap min request size at 2^12 */
519         sqlite3GlobalConfig.mnReq = (1<<12);
520       }
521 
522       if( sqlite3GlobalConfig.pHeap==0 ){
523         /* EVIDENCE-OF: R-49920-60189 If the first pointer (the memory pointer)
524         ** is NULL, then SQLite reverts to using its default memory allocator
525         ** (the system malloc() implementation), undoing any prior invocation of
526         ** SQLITE_CONFIG_MALLOC.
527         **
528         ** Setting sqlite3GlobalConfig.m to all zeros will cause malloc to
529         ** revert to its default implementation when sqlite3_initialize() is run
530         */
531         memset(&sqlite3GlobalConfig.m, 0, sizeof(sqlite3GlobalConfig.m));
532       }else{
533         /* EVIDENCE-OF: R-61006-08918 If the memory pointer is not NULL then the
534         ** alternative memory allocator is engaged to handle all of SQLites
535         ** memory allocation needs. */
536 #ifdef SQLITE_ENABLE_MEMSYS3
537         sqlite3GlobalConfig.m = *sqlite3MemGetMemsys3();
538 #endif
539 #ifdef SQLITE_ENABLE_MEMSYS5
540         sqlite3GlobalConfig.m = *sqlite3MemGetMemsys5();
541 #endif
542       }
543       break;
544     }
545 #endif
546 
547     case SQLITE_CONFIG_LOOKASIDE: {
548       sqlite3GlobalConfig.szLookaside = va_arg(ap, int);
549       sqlite3GlobalConfig.nLookaside = va_arg(ap, int);
550       break;
551     }
552 
553     /* Record a pointer to the logger function and its first argument.
554     ** The default is NULL.  Logging is disabled if the function pointer is
555     ** NULL.
556     */
557     case SQLITE_CONFIG_LOG: {
558       /* MSVC is picky about pulling func ptrs from va lists.
559       ** http://support.microsoft.com/kb/47961
560       ** sqlite3GlobalConfig.xLog = va_arg(ap, void(*)(void*,int,const char*));
561       */
562       typedef void(*LOGFUNC_t)(void*,int,const char*);
563       sqlite3GlobalConfig.xLog = va_arg(ap, LOGFUNC_t);
564       sqlite3GlobalConfig.pLogArg = va_arg(ap, void*);
565       break;
566     }
567 
568     /* EVIDENCE-OF: R-55548-33817 The compile-time setting for URI filenames
569     ** can be changed at start-time using the
570     ** sqlite3_config(SQLITE_CONFIG_URI,1) or
571     ** sqlite3_config(SQLITE_CONFIG_URI,0) configuration calls.
572     */
573     case SQLITE_CONFIG_URI: {
574       /* EVIDENCE-OF: R-25451-61125 The SQLITE_CONFIG_URI option takes a single
575       ** argument of type int. If non-zero, then URI handling is globally
576       ** enabled. If the parameter is zero, then URI handling is globally
577       ** disabled. */
578       sqlite3GlobalConfig.bOpenUri = va_arg(ap, int);
579       break;
580     }
581 
582     case SQLITE_CONFIG_COVERING_INDEX_SCAN: {
583       /* EVIDENCE-OF: R-36592-02772 The SQLITE_CONFIG_COVERING_INDEX_SCAN
584       ** option takes a single integer argument which is interpreted as a
585       ** boolean in order to enable or disable the use of covering indices for
586       ** full table scans in the query optimizer. */
587       sqlite3GlobalConfig.bUseCis = va_arg(ap, int);
588       break;
589     }
590 
591 #ifdef SQLITE_ENABLE_SQLLOG
592     case SQLITE_CONFIG_SQLLOG: {
593       typedef void(*SQLLOGFUNC_t)(void*, sqlite3*, const char*, int);
594       sqlite3GlobalConfig.xSqllog = va_arg(ap, SQLLOGFUNC_t);
595       sqlite3GlobalConfig.pSqllogArg = va_arg(ap, void *);
596       break;
597     }
598 #endif
599 
600     case SQLITE_CONFIG_MMAP_SIZE: {
601       /* EVIDENCE-OF: R-58063-38258 SQLITE_CONFIG_MMAP_SIZE takes two 64-bit
602       ** integer (sqlite3_int64) values that are the default mmap size limit
603       ** (the default setting for PRAGMA mmap_size) and the maximum allowed
604       ** mmap size limit. */
605       sqlite3_int64 szMmap = va_arg(ap, sqlite3_int64);
606       sqlite3_int64 mxMmap = va_arg(ap, sqlite3_int64);
607       /* EVIDENCE-OF: R-53367-43190 If either argument to this option is
608       ** negative, then that argument is changed to its compile-time default.
609       **
610       ** EVIDENCE-OF: R-34993-45031 The maximum allowed mmap size will be
611       ** silently truncated if necessary so that it does not exceed the
612       ** compile-time maximum mmap size set by the SQLITE_MAX_MMAP_SIZE
613       ** compile-time option.
614       */
615       if( mxMmap<0 || mxMmap>SQLITE_MAX_MMAP_SIZE ){
616         mxMmap = SQLITE_MAX_MMAP_SIZE;
617       }
618       if( szMmap<0 ) szMmap = SQLITE_DEFAULT_MMAP_SIZE;
619       if( szMmap>mxMmap) szMmap = mxMmap;
620       sqlite3GlobalConfig.mxMmap = mxMmap;
621       sqlite3GlobalConfig.szMmap = szMmap;
622       break;
623     }
624 
625 #if SQLITE_OS_WIN && defined(SQLITE_WIN32_MALLOC) /* IMP: R-04780-55815 */
626     case SQLITE_CONFIG_WIN32_HEAPSIZE: {
627       /* EVIDENCE-OF: R-34926-03360 SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit
628       ** unsigned integer value that specifies the maximum size of the created
629       ** heap. */
630       sqlite3GlobalConfig.nHeap = va_arg(ap, int);
631       break;
632     }
633 #endif
634 
635     case SQLITE_CONFIG_PMASZ: {
636       sqlite3GlobalConfig.szPma = va_arg(ap, unsigned int);
637       break;
638     }
639 
640     case SQLITE_CONFIG_STMTJRNL_SPILL: {
641       sqlite3GlobalConfig.nStmtSpill = va_arg(ap, int);
642       break;
643     }
644 
645 #ifdef SQLITE_ENABLE_SORTER_REFERENCES
646     case SQLITE_CONFIG_SORTERREF_SIZE: {
647       int iVal = va_arg(ap, int);
648       if( iVal<0 ){
649         iVal = SQLITE_DEFAULT_SORTERREF_SIZE;
650       }
651       sqlite3GlobalConfig.szSorterRef = (u32)iVal;
652       break;
653     }
654 #endif /* SQLITE_ENABLE_SORTER_REFERENCES */
655 
656     default: {
657       rc = SQLITE_ERROR;
658       break;
659     }
660   }
661   va_end(ap);
662   return rc;
663 }
664 
665 /*
666 ** Set up the lookaside buffers for a database connection.
667 ** Return SQLITE_OK on success.
668 ** If lookaside is already active, return SQLITE_BUSY.
669 **
670 ** The sz parameter is the number of bytes in each lookaside slot.
671 ** The cnt parameter is the number of slots.  If pStart is NULL the
672 ** space for the lookaside memory is obtained from sqlite3_malloc().
673 ** If pStart is not NULL then it is sz*cnt bytes of memory to use for
674 ** the lookaside memory.
675 */
676 static int setupLookaside(sqlite3 *db, void *pBuf, int sz, int cnt){
677 #ifndef SQLITE_OMIT_LOOKASIDE
678   void *pStart;
679 
680   if( sqlite3LookasideUsed(db,0)>0 ){
681     return SQLITE_BUSY;
682   }
683   /* Free any existing lookaside buffer for this handle before
684   ** allocating a new one so we don't have to have space for
685   ** both at the same time.
686   */
687   if( db->lookaside.bMalloced ){
688     sqlite3_free(db->lookaside.pStart);
689   }
690   /* The size of a lookaside slot after ROUNDDOWN8 needs to be larger
691   ** than a pointer to be useful.
692   */
693   sz = ROUNDDOWN8(sz);  /* IMP: R-33038-09382 */
694   if( sz<=(int)sizeof(LookasideSlot*) ) sz = 0;
695   if( cnt<0 ) cnt = 0;
696   if( sz==0 || cnt==0 ){
697     sz = 0;
698     pStart = 0;
699   }else if( pBuf==0 ){
700     sqlite3BeginBenignMalloc();
701     pStart = sqlite3Malloc( sz*cnt );  /* IMP: R-61949-35727 */
702     sqlite3EndBenignMalloc();
703     if( pStart ) cnt = sqlite3MallocSize(pStart)/sz;
704   }else{
705     pStart = pBuf;
706   }
707   db->lookaside.pStart = pStart;
708   db->lookaside.pInit = 0;
709   db->lookaside.pFree = 0;
710   db->lookaside.sz = (u16)sz;
711   if( pStart ){
712     int i;
713     LookasideSlot *p;
714     assert( sz > (int)sizeof(LookasideSlot*) );
715     db->lookaside.nSlot = cnt;
716     p = (LookasideSlot*)pStart;
717     for(i=cnt-1; i>=0; i--){
718       p->pNext = db->lookaside.pInit;
719       db->lookaside.pInit = p;
720       p = (LookasideSlot*)&((u8*)p)[sz];
721     }
722     db->lookaside.pEnd = p;
723     db->lookaside.bDisable = 0;
724     db->lookaside.bMalloced = pBuf==0 ?1:0;
725   }else{
726     db->lookaside.pStart = db;
727     db->lookaside.pEnd = db;
728     db->lookaside.bDisable = 1;
729     db->lookaside.bMalloced = 0;
730     db->lookaside.nSlot = 0;
731   }
732 #endif /* SQLITE_OMIT_LOOKASIDE */
733   return SQLITE_OK;
734 }
735 
736 /*
737 ** Return the mutex associated with a database connection.
738 */
739 sqlite3_mutex *sqlite3_db_mutex(sqlite3 *db){
740 #ifdef SQLITE_ENABLE_API_ARMOR
741   if( !sqlite3SafetyCheckOk(db) ){
742     (void)SQLITE_MISUSE_BKPT;
743     return 0;
744   }
745 #endif
746   return db->mutex;
747 }
748 
749 /*
750 ** Free up as much memory as we can from the given database
751 ** connection.
752 */
753 int sqlite3_db_release_memory(sqlite3 *db){
754   int i;
755 
756 #ifdef SQLITE_ENABLE_API_ARMOR
757   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
758 #endif
759   sqlite3_mutex_enter(db->mutex);
760   sqlite3BtreeEnterAll(db);
761   for(i=0; i<db->nDb; i++){
762     Btree *pBt = db->aDb[i].pBt;
763     if( pBt ){
764       Pager *pPager = sqlite3BtreePager(pBt);
765       sqlite3PagerShrink(pPager);
766     }
767   }
768   sqlite3BtreeLeaveAll(db);
769   sqlite3_mutex_leave(db->mutex);
770   return SQLITE_OK;
771 }
772 
773 /*
774 ** Flush any dirty pages in the pager-cache for any attached database
775 ** to disk.
776 */
777 int sqlite3_db_cacheflush(sqlite3 *db){
778   int i;
779   int rc = SQLITE_OK;
780   int bSeenBusy = 0;
781 
782 #ifdef SQLITE_ENABLE_API_ARMOR
783   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
784 #endif
785   sqlite3_mutex_enter(db->mutex);
786   sqlite3BtreeEnterAll(db);
787   for(i=0; rc==SQLITE_OK && i<db->nDb; i++){
788     Btree *pBt = db->aDb[i].pBt;
789     if( pBt && sqlite3BtreeIsInTrans(pBt) ){
790       Pager *pPager = sqlite3BtreePager(pBt);
791       rc = sqlite3PagerFlush(pPager);
792       if( rc==SQLITE_BUSY ){
793         bSeenBusy = 1;
794         rc = SQLITE_OK;
795       }
796     }
797   }
798   sqlite3BtreeLeaveAll(db);
799   sqlite3_mutex_leave(db->mutex);
800   return ((rc==SQLITE_OK && bSeenBusy) ? SQLITE_BUSY : rc);
801 }
802 
803 /*
804 ** Configuration settings for an individual database connection
805 */
806 int sqlite3_db_config(sqlite3 *db, int op, ...){
807   va_list ap;
808   int rc;
809   va_start(ap, op);
810   switch( op ){
811     case SQLITE_DBCONFIG_MAINDBNAME: {
812       /* IMP: R-06824-28531 */
813       /* IMP: R-36257-52125 */
814       db->aDb[0].zDbSName = va_arg(ap,char*);
815       rc = SQLITE_OK;
816       break;
817     }
818     case SQLITE_DBCONFIG_LOOKASIDE: {
819       void *pBuf = va_arg(ap, void*); /* IMP: R-26835-10964 */
820       int sz = va_arg(ap, int);       /* IMP: R-47871-25994 */
821       int cnt = va_arg(ap, int);      /* IMP: R-04460-53386 */
822       rc = setupLookaside(db, pBuf, sz, cnt);
823       break;
824     }
825     default: {
826       static const struct {
827         int op;      /* The opcode */
828         u32 mask;    /* Mask of the bit in sqlite3.flags to set/clear */
829       } aFlagOp[] = {
830         { SQLITE_DBCONFIG_ENABLE_FKEY,           SQLITE_ForeignKeys    },
831         { SQLITE_DBCONFIG_ENABLE_TRIGGER,        SQLITE_EnableTrigger  },
832         { SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER, SQLITE_Fts3Tokenizer  },
833         { SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION, SQLITE_LoadExtension  },
834         { SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE,      SQLITE_NoCkptOnClose  },
835         { SQLITE_DBCONFIG_ENABLE_QPSG,           SQLITE_EnableQPSG     },
836         { SQLITE_DBCONFIG_TRIGGER_EQP,           SQLITE_TriggerEQP     },
837       };
838       unsigned int i;
839       rc = SQLITE_ERROR; /* IMP: R-42790-23372 */
840       for(i=0; i<ArraySize(aFlagOp); i++){
841         if( aFlagOp[i].op==op ){
842           int onoff = va_arg(ap, int);
843           int *pRes = va_arg(ap, int*);
844           u32 oldFlags = db->flags;
845           if( onoff>0 ){
846             db->flags |= aFlagOp[i].mask;
847           }else if( onoff==0 ){
848             db->flags &= ~aFlagOp[i].mask;
849           }
850           if( oldFlags!=db->flags ){
851             sqlite3ExpirePreparedStatements(db);
852           }
853           if( pRes ){
854             *pRes = (db->flags & aFlagOp[i].mask)!=0;
855           }
856           rc = SQLITE_OK;
857           break;
858         }
859       }
860       break;
861     }
862   }
863   va_end(ap);
864   return rc;
865 }
866 
867 
868 /*
869 ** Return true if the buffer z[0..n-1] contains all spaces.
870 */
871 static int allSpaces(const char *z, int n){
872   while( n>0 && z[n-1]==' ' ){ n--; }
873   return n==0;
874 }
875 
876 /*
877 ** This is the default collating function named "BINARY" which is always
878 ** available.
879 **
880 ** If the padFlag argument is not NULL then space padding at the end
881 ** of strings is ignored.  This implements the RTRIM collation.
882 */
883 static int binCollFunc(
884   void *padFlag,
885   int nKey1, const void *pKey1,
886   int nKey2, const void *pKey2
887 ){
888   int rc, n;
889   n = nKey1<nKey2 ? nKey1 : nKey2;
890   /* EVIDENCE-OF: R-65033-28449 The built-in BINARY collation compares
891   ** strings byte by byte using the memcmp() function from the standard C
892   ** library. */
893   assert( pKey1 && pKey2 );
894   rc = memcmp(pKey1, pKey2, n);
895   if( rc==0 ){
896     if( padFlag
897      && allSpaces(((char*)pKey1)+n, nKey1-n)
898      && allSpaces(((char*)pKey2)+n, nKey2-n)
899     ){
900       /* EVIDENCE-OF: R-31624-24737 RTRIM is like BINARY except that extra
901       ** spaces at the end of either string do not change the result. In other
902       ** words, strings will compare equal to one another as long as they
903       ** differ only in the number of spaces at the end.
904       */
905     }else{
906       rc = nKey1 - nKey2;
907     }
908   }
909   return rc;
910 }
911 
912 /*
913 ** Another built-in collating sequence: NOCASE.
914 **
915 ** This collating sequence is intended to be used for "case independent
916 ** comparison". SQLite's knowledge of upper and lower case equivalents
917 ** extends only to the 26 characters used in the English language.
918 **
919 ** At the moment there is only a UTF-8 implementation.
920 */
921 static int nocaseCollatingFunc(
922   void *NotUsed,
923   int nKey1, const void *pKey1,
924   int nKey2, const void *pKey2
925 ){
926   int r = sqlite3StrNICmp(
927       (const char *)pKey1, (const char *)pKey2, (nKey1<nKey2)?nKey1:nKey2);
928   UNUSED_PARAMETER(NotUsed);
929   if( 0==r ){
930     r = nKey1-nKey2;
931   }
932   return r;
933 }
934 
935 /*
936 ** Return the ROWID of the most recent insert
937 */
938 sqlite_int64 sqlite3_last_insert_rowid(sqlite3 *db){
939 #ifdef SQLITE_ENABLE_API_ARMOR
940   if( !sqlite3SafetyCheckOk(db) ){
941     (void)SQLITE_MISUSE_BKPT;
942     return 0;
943   }
944 #endif
945   return db->lastRowid;
946 }
947 
948 /*
949 ** Set the value returned by the sqlite3_last_insert_rowid() API function.
950 */
951 void sqlite3_set_last_insert_rowid(sqlite3 *db, sqlite3_int64 iRowid){
952 #ifdef SQLITE_ENABLE_API_ARMOR
953   if( !sqlite3SafetyCheckOk(db) ){
954     (void)SQLITE_MISUSE_BKPT;
955     return;
956   }
957 #endif
958   sqlite3_mutex_enter(db->mutex);
959   db->lastRowid = iRowid;
960   sqlite3_mutex_leave(db->mutex);
961 }
962 
963 /*
964 ** Return the number of changes in the most recent call to sqlite3_exec().
965 */
966 int sqlite3_changes(sqlite3 *db){
967 #ifdef SQLITE_ENABLE_API_ARMOR
968   if( !sqlite3SafetyCheckOk(db) ){
969     (void)SQLITE_MISUSE_BKPT;
970     return 0;
971   }
972 #endif
973   return db->nChange;
974 }
975 
976 /*
977 ** Return the number of changes since the database handle was opened.
978 */
979 int sqlite3_total_changes(sqlite3 *db){
980 #ifdef SQLITE_ENABLE_API_ARMOR
981   if( !sqlite3SafetyCheckOk(db) ){
982     (void)SQLITE_MISUSE_BKPT;
983     return 0;
984   }
985 #endif
986   return db->nTotalChange;
987 }
988 
989 /*
990 ** Close all open savepoints. This function only manipulates fields of the
991 ** database handle object, it does not close any savepoints that may be open
992 ** at the b-tree/pager level.
993 */
994 void sqlite3CloseSavepoints(sqlite3 *db){
995   while( db->pSavepoint ){
996     Savepoint *pTmp = db->pSavepoint;
997     db->pSavepoint = pTmp->pNext;
998     sqlite3DbFree(db, pTmp);
999   }
1000   db->nSavepoint = 0;
1001   db->nStatement = 0;
1002   db->isTransactionSavepoint = 0;
1003 }
1004 
1005 /*
1006 ** Invoke the destructor function associated with FuncDef p, if any. Except,
1007 ** if this is not the last copy of the function, do not invoke it. Multiple
1008 ** copies of a single function are created when create_function() is called
1009 ** with SQLITE_ANY as the encoding.
1010 */
1011 static void functionDestroy(sqlite3 *db, FuncDef *p){
1012   FuncDestructor *pDestructor = p->u.pDestructor;
1013   if( pDestructor ){
1014     pDestructor->nRef--;
1015     if( pDestructor->nRef==0 ){
1016       pDestructor->xDestroy(pDestructor->pUserData);
1017       sqlite3DbFree(db, pDestructor);
1018     }
1019   }
1020 }
1021 
1022 /*
1023 ** Disconnect all sqlite3_vtab objects that belong to database connection
1024 ** db. This is called when db is being closed.
1025 */
1026 static void disconnectAllVtab(sqlite3 *db){
1027 #ifndef SQLITE_OMIT_VIRTUALTABLE
1028   int i;
1029   HashElem *p;
1030   sqlite3BtreeEnterAll(db);
1031   for(i=0; i<db->nDb; i++){
1032     Schema *pSchema = db->aDb[i].pSchema;
1033     if( db->aDb[i].pSchema ){
1034       for(p=sqliteHashFirst(&pSchema->tblHash); p; p=sqliteHashNext(p)){
1035         Table *pTab = (Table *)sqliteHashData(p);
1036         if( IsVirtual(pTab) ) sqlite3VtabDisconnect(db, pTab);
1037       }
1038     }
1039   }
1040   for(p=sqliteHashFirst(&db->aModule); p; p=sqliteHashNext(p)){
1041     Module *pMod = (Module *)sqliteHashData(p);
1042     if( pMod->pEpoTab ){
1043       sqlite3VtabDisconnect(db, pMod->pEpoTab);
1044     }
1045   }
1046   sqlite3VtabUnlockList(db);
1047   sqlite3BtreeLeaveAll(db);
1048 #else
1049   UNUSED_PARAMETER(db);
1050 #endif
1051 }
1052 
1053 /*
1054 ** Return TRUE if database connection db has unfinalized prepared
1055 ** statements or unfinished sqlite3_backup objects.
1056 */
1057 static int connectionIsBusy(sqlite3 *db){
1058   int j;
1059   assert( sqlite3_mutex_held(db->mutex) );
1060   if( db->pVdbe ) return 1;
1061   for(j=0; j<db->nDb; j++){
1062     Btree *pBt = db->aDb[j].pBt;
1063     if( pBt && sqlite3BtreeIsInBackup(pBt) ) return 1;
1064   }
1065   return 0;
1066 }
1067 
1068 /*
1069 ** Close an existing SQLite database
1070 */
1071 static int sqlite3Close(sqlite3 *db, int forceZombie){
1072   if( !db ){
1073     /* EVIDENCE-OF: R-63257-11740 Calling sqlite3_close() or
1074     ** sqlite3_close_v2() with a NULL pointer argument is a harmless no-op. */
1075     return SQLITE_OK;
1076   }
1077   if( !sqlite3SafetyCheckSickOrOk(db) ){
1078     return SQLITE_MISUSE_BKPT;
1079   }
1080   sqlite3_mutex_enter(db->mutex);
1081   if( db->mTrace & SQLITE_TRACE_CLOSE ){
1082     db->xTrace(SQLITE_TRACE_CLOSE, db->pTraceArg, db, 0);
1083   }
1084 
1085   /* Force xDisconnect calls on all virtual tables */
1086   disconnectAllVtab(db);
1087 
1088   /* If a transaction is open, the disconnectAllVtab() call above
1089   ** will not have called the xDisconnect() method on any virtual
1090   ** tables in the db->aVTrans[] array. The following sqlite3VtabRollback()
1091   ** call will do so. We need to do this before the check for active
1092   ** SQL statements below, as the v-table implementation may be storing
1093   ** some prepared statements internally.
1094   */
1095   sqlite3VtabRollback(db);
1096 
1097   /* Legacy behavior (sqlite3_close() behavior) is to return
1098   ** SQLITE_BUSY if the connection can not be closed immediately.
1099   */
1100   if( !forceZombie && connectionIsBusy(db) ){
1101     sqlite3ErrorWithMsg(db, SQLITE_BUSY, "unable to close due to unfinalized "
1102        "statements or unfinished backups");
1103     sqlite3_mutex_leave(db->mutex);
1104     return SQLITE_BUSY;
1105   }
1106 
1107 #ifdef SQLITE_ENABLE_SQLLOG
1108   if( sqlite3GlobalConfig.xSqllog ){
1109     /* Closing the handle. Fourth parameter is passed the value 2. */
1110     sqlite3GlobalConfig.xSqllog(sqlite3GlobalConfig.pSqllogArg, db, 0, 2);
1111   }
1112 #endif
1113 
1114   /* Convert the connection into a zombie and then close it.
1115   */
1116   db->magic = SQLITE_MAGIC_ZOMBIE;
1117   sqlite3LeaveMutexAndCloseZombie(db);
1118   return SQLITE_OK;
1119 }
1120 
1121 /*
1122 ** Two variations on the public interface for closing a database
1123 ** connection. The sqlite3_close() version returns SQLITE_BUSY and
1124 ** leaves the connection option if there are unfinalized prepared
1125 ** statements or unfinished sqlite3_backups.  The sqlite3_close_v2()
1126 ** version forces the connection to become a zombie if there are
1127 ** unclosed resources, and arranges for deallocation when the last
1128 ** prepare statement or sqlite3_backup closes.
1129 */
1130 int sqlite3_close(sqlite3 *db){ return sqlite3Close(db,0); }
1131 int sqlite3_close_v2(sqlite3 *db){ return sqlite3Close(db,1); }
1132 
1133 
1134 /*
1135 ** Close the mutex on database connection db.
1136 **
1137 ** Furthermore, if database connection db is a zombie (meaning that there
1138 ** has been a prior call to sqlite3_close(db) or sqlite3_close_v2(db)) and
1139 ** every sqlite3_stmt has now been finalized and every sqlite3_backup has
1140 ** finished, then free all resources.
1141 */
1142 void sqlite3LeaveMutexAndCloseZombie(sqlite3 *db){
1143   HashElem *i;                    /* Hash table iterator */
1144   int j;
1145 
1146   /* If there are outstanding sqlite3_stmt or sqlite3_backup objects
1147   ** or if the connection has not yet been closed by sqlite3_close_v2(),
1148   ** then just leave the mutex and return.
1149   */
1150   if( db->magic!=SQLITE_MAGIC_ZOMBIE || connectionIsBusy(db) ){
1151     sqlite3_mutex_leave(db->mutex);
1152     return;
1153   }
1154 
1155   /* If we reach this point, it means that the database connection has
1156   ** closed all sqlite3_stmt and sqlite3_backup objects and has been
1157   ** passed to sqlite3_close (meaning that it is a zombie).  Therefore,
1158   ** go ahead and free all resources.
1159   */
1160 
1161   /* If a transaction is open, roll it back. This also ensures that if
1162   ** any database schemas have been modified by an uncommitted transaction
1163   ** they are reset. And that the required b-tree mutex is held to make
1164   ** the pager rollback and schema reset an atomic operation. */
1165   sqlite3RollbackAll(db, SQLITE_OK);
1166 
1167   /* Free any outstanding Savepoint structures. */
1168   sqlite3CloseSavepoints(db);
1169 
1170   /* Close all database connections */
1171   for(j=0; j<db->nDb; j++){
1172     struct Db *pDb = &db->aDb[j];
1173     if( pDb->pBt ){
1174       sqlite3BtreeClose(pDb->pBt);
1175       pDb->pBt = 0;
1176       if( j!=1 ){
1177         pDb->pSchema = 0;
1178       }
1179     }
1180   }
1181   /* Clear the TEMP schema separately and last */
1182   if( db->aDb[1].pSchema ){
1183     sqlite3SchemaClear(db->aDb[1].pSchema);
1184   }
1185   sqlite3VtabUnlockList(db);
1186 
1187   /* Free up the array of auxiliary databases */
1188   sqlite3CollapseDatabaseArray(db);
1189   assert( db->nDb<=2 );
1190   assert( db->aDb==db->aDbStatic );
1191 
1192   /* Tell the code in notify.c that the connection no longer holds any
1193   ** locks and does not require any further unlock-notify callbacks.
1194   */
1195   sqlite3ConnectionClosed(db);
1196 
1197   for(i=sqliteHashFirst(&db->aFunc); i; i=sqliteHashNext(i)){
1198     FuncDef *pNext, *p;
1199     p = sqliteHashData(i);
1200     do{
1201       functionDestroy(db, p);
1202       pNext = p->pNext;
1203       sqlite3DbFree(db, p);
1204       p = pNext;
1205     }while( p );
1206   }
1207   sqlite3HashClear(&db->aFunc);
1208   for(i=sqliteHashFirst(&db->aCollSeq); i; i=sqliteHashNext(i)){
1209     CollSeq *pColl = (CollSeq *)sqliteHashData(i);
1210     /* Invoke any destructors registered for collation sequence user data. */
1211     for(j=0; j<3; j++){
1212       if( pColl[j].xDel ){
1213         pColl[j].xDel(pColl[j].pUser);
1214       }
1215     }
1216     sqlite3DbFree(db, pColl);
1217   }
1218   sqlite3HashClear(&db->aCollSeq);
1219 #ifndef SQLITE_OMIT_VIRTUALTABLE
1220   for(i=sqliteHashFirst(&db->aModule); i; i=sqliteHashNext(i)){
1221     Module *pMod = (Module *)sqliteHashData(i);
1222     if( pMod->xDestroy ){
1223       pMod->xDestroy(pMod->pAux);
1224     }
1225     sqlite3VtabEponymousTableClear(db, pMod);
1226     sqlite3DbFree(db, pMod);
1227   }
1228   sqlite3HashClear(&db->aModule);
1229 #endif
1230 
1231   sqlite3Error(db, SQLITE_OK); /* Deallocates any cached error strings. */
1232   sqlite3ValueFree(db->pErr);
1233   sqlite3CloseExtensions(db);
1234 #if SQLITE_USER_AUTHENTICATION
1235   sqlite3_free(db->auth.zAuthUser);
1236   sqlite3_free(db->auth.zAuthPW);
1237 #endif
1238 
1239   db->magic = SQLITE_MAGIC_ERROR;
1240 
1241   /* The temp-database schema is allocated differently from the other schema
1242   ** objects (using sqliteMalloc() directly, instead of sqlite3BtreeSchema()).
1243   ** So it needs to be freed here. Todo: Why not roll the temp schema into
1244   ** the same sqliteMalloc() as the one that allocates the database
1245   ** structure?
1246   */
1247   sqlite3DbFree(db, db->aDb[1].pSchema);
1248   sqlite3_mutex_leave(db->mutex);
1249   db->magic = SQLITE_MAGIC_CLOSED;
1250   sqlite3_mutex_free(db->mutex);
1251   assert( sqlite3LookasideUsed(db,0)==0 );
1252   if( db->lookaside.bMalloced ){
1253     sqlite3_free(db->lookaside.pStart);
1254   }
1255   sqlite3_free(db);
1256 }
1257 
1258 /*
1259 ** Rollback all database files.  If tripCode is not SQLITE_OK, then
1260 ** any write cursors are invalidated ("tripped" - as in "tripping a circuit
1261 ** breaker") and made to return tripCode if there are any further
1262 ** attempts to use that cursor.  Read cursors remain open and valid
1263 ** but are "saved" in case the table pages are moved around.
1264 */
1265 void sqlite3RollbackAll(sqlite3 *db, int tripCode){
1266   int i;
1267   int inTrans = 0;
1268   int schemaChange;
1269   assert( sqlite3_mutex_held(db->mutex) );
1270   sqlite3BeginBenignMalloc();
1271 
1272   /* Obtain all b-tree mutexes before making any calls to BtreeRollback().
1273   ** This is important in case the transaction being rolled back has
1274   ** modified the database schema. If the b-tree mutexes are not taken
1275   ** here, then another shared-cache connection might sneak in between
1276   ** the database rollback and schema reset, which can cause false
1277   ** corruption reports in some cases.  */
1278   sqlite3BtreeEnterAll(db);
1279   schemaChange = (db->mDbFlags & DBFLAG_SchemaChange)!=0 && db->init.busy==0;
1280 
1281   for(i=0; i<db->nDb; i++){
1282     Btree *p = db->aDb[i].pBt;
1283     if( p ){
1284       if( sqlite3BtreeIsInTrans(p) ){
1285         inTrans = 1;
1286       }
1287       sqlite3BtreeRollback(p, tripCode, !schemaChange);
1288     }
1289   }
1290   sqlite3VtabRollback(db);
1291   sqlite3EndBenignMalloc();
1292 
1293   if( (db->mDbFlags&DBFLAG_SchemaChange)!=0 && db->init.busy==0 ){
1294     sqlite3ExpirePreparedStatements(db);
1295     sqlite3ResetAllSchemasOfConnection(db);
1296   }
1297   sqlite3BtreeLeaveAll(db);
1298 
1299   /* Any deferred constraint violations have now been resolved. */
1300   db->nDeferredCons = 0;
1301   db->nDeferredImmCons = 0;
1302   db->flags &= ~SQLITE_DeferFKs;
1303 
1304   /* If one has been configured, invoke the rollback-hook callback */
1305   if( db->xRollbackCallback && (inTrans || !db->autoCommit) ){
1306     db->xRollbackCallback(db->pRollbackArg);
1307   }
1308 }
1309 
1310 /*
1311 ** Return a static string containing the name corresponding to the error code
1312 ** specified in the argument.
1313 */
1314 #if defined(SQLITE_NEED_ERR_NAME)
1315 const char *sqlite3ErrName(int rc){
1316   const char *zName = 0;
1317   int i, origRc = rc;
1318   for(i=0; i<2 && zName==0; i++, rc &= 0xff){
1319     switch( rc ){
1320       case SQLITE_OK:                 zName = "SQLITE_OK";                break;
1321       case SQLITE_ERROR:              zName = "SQLITE_ERROR";             break;
1322       case SQLITE_INTERNAL:           zName = "SQLITE_INTERNAL";          break;
1323       case SQLITE_PERM:               zName = "SQLITE_PERM";              break;
1324       case SQLITE_ABORT:              zName = "SQLITE_ABORT";             break;
1325       case SQLITE_ABORT_ROLLBACK:     zName = "SQLITE_ABORT_ROLLBACK";    break;
1326       case SQLITE_BUSY:               zName = "SQLITE_BUSY";              break;
1327       case SQLITE_BUSY_RECOVERY:      zName = "SQLITE_BUSY_RECOVERY";     break;
1328       case SQLITE_BUSY_SNAPSHOT:      zName = "SQLITE_BUSY_SNAPSHOT";     break;
1329       case SQLITE_LOCKED:             zName = "SQLITE_LOCKED";            break;
1330       case SQLITE_LOCKED_SHAREDCACHE: zName = "SQLITE_LOCKED_SHAREDCACHE";break;
1331       case SQLITE_NOMEM:              zName = "SQLITE_NOMEM";             break;
1332       case SQLITE_READONLY:           zName = "SQLITE_READONLY";          break;
1333       case SQLITE_READONLY_RECOVERY:  zName = "SQLITE_READONLY_RECOVERY"; break;
1334       case SQLITE_READONLY_CANTINIT:  zName = "SQLITE_READONLY_CANTINIT"; break;
1335       case SQLITE_READONLY_ROLLBACK:  zName = "SQLITE_READONLY_ROLLBACK"; break;
1336       case SQLITE_READONLY_DBMOVED:   zName = "SQLITE_READONLY_DBMOVED";  break;
1337       case SQLITE_READONLY_DIRECTORY: zName = "SQLITE_READONLY_DIRECTORY";break;
1338       case SQLITE_INTERRUPT:          zName = "SQLITE_INTERRUPT";         break;
1339       case SQLITE_IOERR:              zName = "SQLITE_IOERR";             break;
1340       case SQLITE_IOERR_READ:         zName = "SQLITE_IOERR_READ";        break;
1341       case SQLITE_IOERR_SHORT_READ:   zName = "SQLITE_IOERR_SHORT_READ";  break;
1342       case SQLITE_IOERR_WRITE:        zName = "SQLITE_IOERR_WRITE";       break;
1343       case SQLITE_IOERR_FSYNC:        zName = "SQLITE_IOERR_FSYNC";       break;
1344       case SQLITE_IOERR_DIR_FSYNC:    zName = "SQLITE_IOERR_DIR_FSYNC";   break;
1345       case SQLITE_IOERR_TRUNCATE:     zName = "SQLITE_IOERR_TRUNCATE";    break;
1346       case SQLITE_IOERR_FSTAT:        zName = "SQLITE_IOERR_FSTAT";       break;
1347       case SQLITE_IOERR_UNLOCK:       zName = "SQLITE_IOERR_UNLOCK";      break;
1348       case SQLITE_IOERR_RDLOCK:       zName = "SQLITE_IOERR_RDLOCK";      break;
1349       case SQLITE_IOERR_DELETE:       zName = "SQLITE_IOERR_DELETE";      break;
1350       case SQLITE_IOERR_NOMEM:        zName = "SQLITE_IOERR_NOMEM";       break;
1351       case SQLITE_IOERR_ACCESS:       zName = "SQLITE_IOERR_ACCESS";      break;
1352       case SQLITE_IOERR_CHECKRESERVEDLOCK:
1353                                 zName = "SQLITE_IOERR_CHECKRESERVEDLOCK"; break;
1354       case SQLITE_IOERR_LOCK:         zName = "SQLITE_IOERR_LOCK";        break;
1355       case SQLITE_IOERR_CLOSE:        zName = "SQLITE_IOERR_CLOSE";       break;
1356       case SQLITE_IOERR_DIR_CLOSE:    zName = "SQLITE_IOERR_DIR_CLOSE";   break;
1357       case SQLITE_IOERR_SHMOPEN:      zName = "SQLITE_IOERR_SHMOPEN";     break;
1358       case SQLITE_IOERR_SHMSIZE:      zName = "SQLITE_IOERR_SHMSIZE";     break;
1359       case SQLITE_IOERR_SHMLOCK:      zName = "SQLITE_IOERR_SHMLOCK";     break;
1360       case SQLITE_IOERR_SHMMAP:       zName = "SQLITE_IOERR_SHMMAP";      break;
1361       case SQLITE_IOERR_SEEK:         zName = "SQLITE_IOERR_SEEK";        break;
1362       case SQLITE_IOERR_DELETE_NOENT: zName = "SQLITE_IOERR_DELETE_NOENT";break;
1363       case SQLITE_IOERR_MMAP:         zName = "SQLITE_IOERR_MMAP";        break;
1364       case SQLITE_IOERR_GETTEMPPATH:  zName = "SQLITE_IOERR_GETTEMPPATH"; break;
1365       case SQLITE_IOERR_CONVPATH:     zName = "SQLITE_IOERR_CONVPATH";    break;
1366       case SQLITE_CORRUPT:            zName = "SQLITE_CORRUPT";           break;
1367       case SQLITE_CORRUPT_VTAB:       zName = "SQLITE_CORRUPT_VTAB";      break;
1368       case SQLITE_NOTFOUND:           zName = "SQLITE_NOTFOUND";          break;
1369       case SQLITE_FULL:               zName = "SQLITE_FULL";              break;
1370       case SQLITE_CANTOPEN:           zName = "SQLITE_CANTOPEN";          break;
1371       case SQLITE_CANTOPEN_NOTEMPDIR: zName = "SQLITE_CANTOPEN_NOTEMPDIR";break;
1372       case SQLITE_CANTOPEN_ISDIR:     zName = "SQLITE_CANTOPEN_ISDIR";    break;
1373       case SQLITE_CANTOPEN_FULLPATH:  zName = "SQLITE_CANTOPEN_FULLPATH"; break;
1374       case SQLITE_CANTOPEN_CONVPATH:  zName = "SQLITE_CANTOPEN_CONVPATH"; break;
1375       case SQLITE_PROTOCOL:           zName = "SQLITE_PROTOCOL";          break;
1376       case SQLITE_EMPTY:              zName = "SQLITE_EMPTY";             break;
1377       case SQLITE_SCHEMA:             zName = "SQLITE_SCHEMA";            break;
1378       case SQLITE_TOOBIG:             zName = "SQLITE_TOOBIG";            break;
1379       case SQLITE_CONSTRAINT:         zName = "SQLITE_CONSTRAINT";        break;
1380       case SQLITE_CONSTRAINT_UNIQUE:  zName = "SQLITE_CONSTRAINT_UNIQUE"; break;
1381       case SQLITE_CONSTRAINT_TRIGGER: zName = "SQLITE_CONSTRAINT_TRIGGER";break;
1382       case SQLITE_CONSTRAINT_FOREIGNKEY:
1383                                 zName = "SQLITE_CONSTRAINT_FOREIGNKEY";   break;
1384       case SQLITE_CONSTRAINT_CHECK:   zName = "SQLITE_CONSTRAINT_CHECK";  break;
1385       case SQLITE_CONSTRAINT_PRIMARYKEY:
1386                                 zName = "SQLITE_CONSTRAINT_PRIMARYKEY";   break;
1387       case SQLITE_CONSTRAINT_NOTNULL: zName = "SQLITE_CONSTRAINT_NOTNULL";break;
1388       case SQLITE_CONSTRAINT_COMMITHOOK:
1389                                 zName = "SQLITE_CONSTRAINT_COMMITHOOK";   break;
1390       case SQLITE_CONSTRAINT_VTAB:    zName = "SQLITE_CONSTRAINT_VTAB";   break;
1391       case SQLITE_CONSTRAINT_FUNCTION:
1392                                 zName = "SQLITE_CONSTRAINT_FUNCTION";     break;
1393       case SQLITE_CONSTRAINT_ROWID:   zName = "SQLITE_CONSTRAINT_ROWID";  break;
1394       case SQLITE_MISMATCH:           zName = "SQLITE_MISMATCH";          break;
1395       case SQLITE_MISUSE:             zName = "SQLITE_MISUSE";            break;
1396       case SQLITE_NOLFS:              zName = "SQLITE_NOLFS";             break;
1397       case SQLITE_AUTH:               zName = "SQLITE_AUTH";              break;
1398       case SQLITE_FORMAT:             zName = "SQLITE_FORMAT";            break;
1399       case SQLITE_RANGE:              zName = "SQLITE_RANGE";             break;
1400       case SQLITE_NOTADB:             zName = "SQLITE_NOTADB";            break;
1401       case SQLITE_ROW:                zName = "SQLITE_ROW";               break;
1402       case SQLITE_NOTICE:             zName = "SQLITE_NOTICE";            break;
1403       case SQLITE_NOTICE_RECOVER_WAL: zName = "SQLITE_NOTICE_RECOVER_WAL";break;
1404       case SQLITE_NOTICE_RECOVER_ROLLBACK:
1405                                 zName = "SQLITE_NOTICE_RECOVER_ROLLBACK"; break;
1406       case SQLITE_WARNING:            zName = "SQLITE_WARNING";           break;
1407       case SQLITE_WARNING_AUTOINDEX:  zName = "SQLITE_WARNING_AUTOINDEX"; break;
1408       case SQLITE_DONE:               zName = "SQLITE_DONE";              break;
1409     }
1410   }
1411   if( zName==0 ){
1412     static char zBuf[50];
1413     sqlite3_snprintf(sizeof(zBuf), zBuf, "SQLITE_UNKNOWN(%d)", origRc);
1414     zName = zBuf;
1415   }
1416   return zName;
1417 }
1418 #endif
1419 
1420 /*
1421 ** Return a static string that describes the kind of error specified in the
1422 ** argument.
1423 */
1424 const char *sqlite3ErrStr(int rc){
1425   static const char* const aMsg[] = {
1426     /* SQLITE_OK          */ "not an error",
1427     /* SQLITE_ERROR       */ "SQL logic error",
1428     /* SQLITE_INTERNAL    */ 0,
1429     /* SQLITE_PERM        */ "access permission denied",
1430     /* SQLITE_ABORT       */ "query aborted",
1431     /* SQLITE_BUSY        */ "database is locked",
1432     /* SQLITE_LOCKED      */ "database table is locked",
1433     /* SQLITE_NOMEM       */ "out of memory",
1434     /* SQLITE_READONLY    */ "attempt to write a readonly database",
1435     /* SQLITE_INTERRUPT   */ "interrupted",
1436     /* SQLITE_IOERR       */ "disk I/O error",
1437     /* SQLITE_CORRUPT     */ "database disk image is malformed",
1438     /* SQLITE_NOTFOUND    */ "unknown operation",
1439     /* SQLITE_FULL        */ "database or disk is full",
1440     /* SQLITE_CANTOPEN    */ "unable to open database file",
1441     /* SQLITE_PROTOCOL    */ "locking protocol",
1442     /* SQLITE_EMPTY       */ 0,
1443     /* SQLITE_SCHEMA      */ "database schema has changed",
1444     /* SQLITE_TOOBIG      */ "string or blob too big",
1445     /* SQLITE_CONSTRAINT  */ "constraint failed",
1446     /* SQLITE_MISMATCH    */ "datatype mismatch",
1447     /* SQLITE_MISUSE      */ "bad parameter or other API misuse",
1448 #ifdef SQLITE_DISABLE_LFS
1449     /* SQLITE_NOLFS       */ "large file support is disabled",
1450 #else
1451     /* SQLITE_NOLFS       */ 0,
1452 #endif
1453     /* SQLITE_AUTH        */ "authorization denied",
1454     /* SQLITE_FORMAT      */ 0,
1455     /* SQLITE_RANGE       */ "column index out of range",
1456     /* SQLITE_NOTADB      */ "file is not a database",
1457     /* SQLITE_NOTICE      */ "notification message",
1458     /* SQLITE_WARNING     */ "warning message",
1459   };
1460   const char *zErr = "unknown error";
1461   switch( rc ){
1462     case SQLITE_ABORT_ROLLBACK: {
1463       zErr = "abort due to ROLLBACK";
1464       break;
1465     }
1466     case SQLITE_ROW: {
1467       zErr = "another row available";
1468       break;
1469     }
1470     case SQLITE_DONE: {
1471       zErr = "no more rows available";
1472       break;
1473     }
1474     default: {
1475       rc &= 0xff;
1476       if( ALWAYS(rc>=0) && rc<ArraySize(aMsg) && aMsg[rc]!=0 ){
1477         zErr = aMsg[rc];
1478       }
1479       break;
1480     }
1481   }
1482   return zErr;
1483 }
1484 
1485 /*
1486 ** This routine implements a busy callback that sleeps and tries
1487 ** again until a timeout value is reached.  The timeout value is
1488 ** an integer number of milliseconds passed in as the first
1489 ** argument.
1490 **
1491 ** Return non-zero to retry the lock.  Return zero to stop trying
1492 ** and cause SQLite to return SQLITE_BUSY.
1493 */
1494 static int sqliteDefaultBusyCallback(
1495   void *ptr,               /* Database connection */
1496   int count,               /* Number of times table has been busy */
1497   sqlite3_file *pFile      /* The file on which the lock occurred */
1498 ){
1499 #if SQLITE_OS_WIN || HAVE_USLEEP
1500   /* This case is for systems that have support for sleeping for fractions of
1501   ** a second.  Examples:  All windows systems, unix systems with usleep() */
1502   static const u8 delays[] =
1503      { 1, 2, 5, 10, 15, 20, 25, 25,  25,  50,  50, 100 };
1504   static const u8 totals[] =
1505      { 0, 1, 3,  8, 18, 33, 53, 78, 103, 128, 178, 228 };
1506 # define NDELAY ArraySize(delays)
1507   sqlite3 *db = (sqlite3 *)ptr;
1508   int tmout = db->busyTimeout;
1509   int delay, prior;
1510 
1511 #ifdef SQLITE_ENABLE_SETLK_TIMEOUT
1512   if( sqlite3OsFileControl(pFile,SQLITE_FCNTL_LOCK_TIMEOUT,&tmout)==SQLITE_OK ){
1513     if( count ){
1514       tmout = 0;
1515       sqlite3OsFileControl(pFile, SQLITE_FCNTL_LOCK_TIMEOUT, &tmout);
1516       return 0;
1517     }else{
1518       return 1;
1519     }
1520   }
1521 #else
1522   UNUSED_PARAMETER(pFile);
1523 #endif
1524   assert( count>=0 );
1525   if( count < NDELAY ){
1526     delay = delays[count];
1527     prior = totals[count];
1528   }else{
1529     delay = delays[NDELAY-1];
1530     prior = totals[NDELAY-1] + delay*(count-(NDELAY-1));
1531   }
1532   if( prior + delay > tmout ){
1533     delay = tmout - prior;
1534     if( delay<=0 ) return 0;
1535   }
1536   sqlite3OsSleep(db->pVfs, delay*1000);
1537   return 1;
1538 #else
1539   /* This case for unix systems that lack usleep() support.  Sleeping
1540   ** must be done in increments of whole seconds */
1541   sqlite3 *db = (sqlite3 *)ptr;
1542   int tmout = ((sqlite3 *)ptr)->busyTimeout;
1543   UNUSED_PARAMETER(pFile);
1544   if( (count+1)*1000 > tmout ){
1545     return 0;
1546   }
1547   sqlite3OsSleep(db->pVfs, 1000000);
1548   return 1;
1549 #endif
1550 }
1551 
1552 /*
1553 ** Invoke the given busy handler.
1554 **
1555 ** This routine is called when an operation failed to acquire a
1556 ** lock on VFS file pFile.
1557 **
1558 ** If this routine returns non-zero, the lock is retried.  If it
1559 ** returns 0, the operation aborts with an SQLITE_BUSY error.
1560 */
1561 int sqlite3InvokeBusyHandler(BusyHandler *p, sqlite3_file *pFile){
1562   int rc;
1563   if( p->xBusyHandler==0 || p->nBusy<0 ) return 0;
1564   if( p->bExtraFileArg ){
1565     /* Add an extra parameter with the pFile pointer to the end of the
1566     ** callback argument list */
1567     int (*xTra)(void*,int,sqlite3_file*);
1568     xTra = (int(*)(void*,int,sqlite3_file*))p->xBusyHandler;
1569     rc = xTra(p->pBusyArg, p->nBusy, pFile);
1570   }else{
1571     /* Legacy style busy handler callback */
1572     rc = p->xBusyHandler(p->pBusyArg, p->nBusy);
1573   }
1574   if( rc==0 ){
1575     p->nBusy = -1;
1576   }else{
1577     p->nBusy++;
1578   }
1579   return rc;
1580 }
1581 
1582 /*
1583 ** This routine sets the busy callback for an Sqlite database to the
1584 ** given callback function with the given argument.
1585 */
1586 int sqlite3_busy_handler(
1587   sqlite3 *db,
1588   int (*xBusy)(void*,int),
1589   void *pArg
1590 ){
1591 #ifdef SQLITE_ENABLE_API_ARMOR
1592   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
1593 #endif
1594   sqlite3_mutex_enter(db->mutex);
1595   db->busyHandler.xBusyHandler = xBusy;
1596   db->busyHandler.pBusyArg = pArg;
1597   db->busyHandler.nBusy = 0;
1598   db->busyHandler.bExtraFileArg = 0;
1599   db->busyTimeout = 0;
1600   sqlite3_mutex_leave(db->mutex);
1601   return SQLITE_OK;
1602 }
1603 
1604 #ifndef SQLITE_OMIT_PROGRESS_CALLBACK
1605 /*
1606 ** This routine sets the progress callback for an Sqlite database to the
1607 ** given callback function with the given argument. The progress callback will
1608 ** be invoked every nOps opcodes.
1609 */
1610 void sqlite3_progress_handler(
1611   sqlite3 *db,
1612   int nOps,
1613   int (*xProgress)(void*),
1614   void *pArg
1615 ){
1616 #ifdef SQLITE_ENABLE_API_ARMOR
1617   if( !sqlite3SafetyCheckOk(db) ){
1618     (void)SQLITE_MISUSE_BKPT;
1619     return;
1620   }
1621 #endif
1622   sqlite3_mutex_enter(db->mutex);
1623   if( nOps>0 ){
1624     db->xProgress = xProgress;
1625     db->nProgressOps = (unsigned)nOps;
1626     db->pProgressArg = pArg;
1627   }else{
1628     db->xProgress = 0;
1629     db->nProgressOps = 0;
1630     db->pProgressArg = 0;
1631   }
1632   sqlite3_mutex_leave(db->mutex);
1633 }
1634 #endif
1635 
1636 
1637 /*
1638 ** This routine installs a default busy handler that waits for the
1639 ** specified number of milliseconds before returning 0.
1640 */
1641 int sqlite3_busy_timeout(sqlite3 *db, int ms){
1642 #ifdef SQLITE_ENABLE_API_ARMOR
1643   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
1644 #endif
1645   if( ms>0 ){
1646     sqlite3_busy_handler(db, (int(*)(void*,int))sqliteDefaultBusyCallback,
1647                              (void*)db);
1648     db->busyTimeout = ms;
1649     db->busyHandler.bExtraFileArg = 1;
1650   }else{
1651     sqlite3_busy_handler(db, 0, 0);
1652   }
1653   return SQLITE_OK;
1654 }
1655 
1656 /*
1657 ** Cause any pending operation to stop at its earliest opportunity.
1658 */
1659 void sqlite3_interrupt(sqlite3 *db){
1660 #ifdef SQLITE_ENABLE_API_ARMOR
1661   if( !sqlite3SafetyCheckOk(db) && (db==0 || db->magic!=SQLITE_MAGIC_ZOMBIE) ){
1662     (void)SQLITE_MISUSE_BKPT;
1663     return;
1664   }
1665 #endif
1666   db->u1.isInterrupted = 1;
1667 }
1668 
1669 
1670 /*
1671 ** This function is exactly the same as sqlite3_create_function(), except
1672 ** that it is designed to be called by internal code. The difference is
1673 ** that if a malloc() fails in sqlite3_create_function(), an error code
1674 ** is returned and the mallocFailed flag cleared.
1675 */
1676 int sqlite3CreateFunc(
1677   sqlite3 *db,
1678   const char *zFunctionName,
1679   int nArg,
1680   int enc,
1681   void *pUserData,
1682   void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
1683   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
1684   void (*xFinal)(sqlite3_context*),
1685   FuncDestructor *pDestructor
1686 ){
1687   FuncDef *p;
1688   int nName;
1689   int extraFlags;
1690 
1691   assert( sqlite3_mutex_held(db->mutex) );
1692   if( zFunctionName==0 ||
1693       (xSFunc && (xFinal || xStep)) ||
1694       (!xSFunc && (xFinal && !xStep)) ||
1695       (!xSFunc && (!xFinal && xStep)) ||
1696       (nArg<-1 || nArg>SQLITE_MAX_FUNCTION_ARG) ||
1697       (255<(nName = sqlite3Strlen30( zFunctionName))) ){
1698     return SQLITE_MISUSE_BKPT;
1699   }
1700 
1701   assert( SQLITE_FUNC_CONSTANT==SQLITE_DETERMINISTIC );
1702   extraFlags = enc &  SQLITE_DETERMINISTIC;
1703   enc &= (SQLITE_FUNC_ENCMASK|SQLITE_ANY);
1704 
1705 #ifndef SQLITE_OMIT_UTF16
1706   /* If SQLITE_UTF16 is specified as the encoding type, transform this
1707   ** to one of SQLITE_UTF16LE or SQLITE_UTF16BE using the
1708   ** SQLITE_UTF16NATIVE macro. SQLITE_UTF16 is not used internally.
1709   **
1710   ** If SQLITE_ANY is specified, add three versions of the function
1711   ** to the hash table.
1712   */
1713   if( enc==SQLITE_UTF16 ){
1714     enc = SQLITE_UTF16NATIVE;
1715   }else if( enc==SQLITE_ANY ){
1716     int rc;
1717     rc = sqlite3CreateFunc(db, zFunctionName, nArg, SQLITE_UTF8|extraFlags,
1718          pUserData, xSFunc, xStep, xFinal, pDestructor);
1719     if( rc==SQLITE_OK ){
1720       rc = sqlite3CreateFunc(db, zFunctionName, nArg, SQLITE_UTF16LE|extraFlags,
1721           pUserData, xSFunc, xStep, xFinal, pDestructor);
1722     }
1723     if( rc!=SQLITE_OK ){
1724       return rc;
1725     }
1726     enc = SQLITE_UTF16BE;
1727   }
1728 #else
1729   enc = SQLITE_UTF8;
1730 #endif
1731 
1732   /* Check if an existing function is being overridden or deleted. If so,
1733   ** and there are active VMs, then return SQLITE_BUSY. If a function
1734   ** is being overridden/deleted but there are no active VMs, allow the
1735   ** operation to continue but invalidate all precompiled statements.
1736   */
1737   p = sqlite3FindFunction(db, zFunctionName, nArg, (u8)enc, 0);
1738   if( p && (p->funcFlags & SQLITE_FUNC_ENCMASK)==enc && p->nArg==nArg ){
1739     if( db->nVdbeActive ){
1740       sqlite3ErrorWithMsg(db, SQLITE_BUSY,
1741         "unable to delete/modify user-function due to active statements");
1742       assert( !db->mallocFailed );
1743       return SQLITE_BUSY;
1744     }else{
1745       sqlite3ExpirePreparedStatements(db);
1746     }
1747   }
1748 
1749   p = sqlite3FindFunction(db, zFunctionName, nArg, (u8)enc, 1);
1750   assert(p || db->mallocFailed);
1751   if( !p ){
1752     return SQLITE_NOMEM_BKPT;
1753   }
1754 
1755   /* If an older version of the function with a configured destructor is
1756   ** being replaced invoke the destructor function here. */
1757   functionDestroy(db, p);
1758 
1759   if( pDestructor ){
1760     pDestructor->nRef++;
1761   }
1762   p->u.pDestructor = pDestructor;
1763   p->funcFlags = (p->funcFlags & SQLITE_FUNC_ENCMASK) | extraFlags;
1764   testcase( p->funcFlags & SQLITE_DETERMINISTIC );
1765   p->xSFunc = xSFunc ? xSFunc : xStep;
1766   p->xFinalize = xFinal;
1767   p->pUserData = pUserData;
1768   p->nArg = (u16)nArg;
1769   return SQLITE_OK;
1770 }
1771 
1772 /*
1773 ** Create new user functions.
1774 */
1775 int sqlite3_create_function(
1776   sqlite3 *db,
1777   const char *zFunc,
1778   int nArg,
1779   int enc,
1780   void *p,
1781   void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
1782   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
1783   void (*xFinal)(sqlite3_context*)
1784 ){
1785   return sqlite3_create_function_v2(db, zFunc, nArg, enc, p, xSFunc, xStep,
1786                                     xFinal, 0);
1787 }
1788 
1789 int sqlite3_create_function_v2(
1790   sqlite3 *db,
1791   const char *zFunc,
1792   int nArg,
1793   int enc,
1794   void *p,
1795   void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
1796   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
1797   void (*xFinal)(sqlite3_context*),
1798   void (*xDestroy)(void *)
1799 ){
1800   int rc = SQLITE_ERROR;
1801   FuncDestructor *pArg = 0;
1802 
1803 #ifdef SQLITE_ENABLE_API_ARMOR
1804   if( !sqlite3SafetyCheckOk(db) ){
1805     return SQLITE_MISUSE_BKPT;
1806   }
1807 #endif
1808   sqlite3_mutex_enter(db->mutex);
1809   if( xDestroy ){
1810     pArg = (FuncDestructor *)sqlite3DbMallocZero(db, sizeof(FuncDestructor));
1811     if( !pArg ){
1812       xDestroy(p);
1813       goto out;
1814     }
1815     pArg->xDestroy = xDestroy;
1816     pArg->pUserData = p;
1817   }
1818   rc = sqlite3CreateFunc(db, zFunc, nArg, enc, p, xSFunc, xStep, xFinal, pArg);
1819   if( pArg && pArg->nRef==0 ){
1820     assert( rc!=SQLITE_OK );
1821     xDestroy(p);
1822     sqlite3DbFree(db, pArg);
1823   }
1824 
1825  out:
1826   rc = sqlite3ApiExit(db, rc);
1827   sqlite3_mutex_leave(db->mutex);
1828   return rc;
1829 }
1830 
1831 #ifndef SQLITE_OMIT_UTF16
1832 int sqlite3_create_function16(
1833   sqlite3 *db,
1834   const void *zFunctionName,
1835   int nArg,
1836   int eTextRep,
1837   void *p,
1838   void (*xSFunc)(sqlite3_context*,int,sqlite3_value**),
1839   void (*xStep)(sqlite3_context*,int,sqlite3_value**),
1840   void (*xFinal)(sqlite3_context*)
1841 ){
1842   int rc;
1843   char *zFunc8;
1844 
1845 #ifdef SQLITE_ENABLE_API_ARMOR
1846   if( !sqlite3SafetyCheckOk(db) || zFunctionName==0 ) return SQLITE_MISUSE_BKPT;
1847 #endif
1848   sqlite3_mutex_enter(db->mutex);
1849   assert( !db->mallocFailed );
1850   zFunc8 = sqlite3Utf16to8(db, zFunctionName, -1, SQLITE_UTF16NATIVE);
1851   rc = sqlite3CreateFunc(db, zFunc8, nArg, eTextRep, p, xSFunc,xStep,xFinal,0);
1852   sqlite3DbFree(db, zFunc8);
1853   rc = sqlite3ApiExit(db, rc);
1854   sqlite3_mutex_leave(db->mutex);
1855   return rc;
1856 }
1857 #endif
1858 
1859 
1860 /*
1861 ** Declare that a function has been overloaded by a virtual table.
1862 **
1863 ** If the function already exists as a regular global function, then
1864 ** this routine is a no-op.  If the function does not exist, then create
1865 ** a new one that always throws a run-time error.
1866 **
1867 ** When virtual tables intend to provide an overloaded function, they
1868 ** should call this routine to make sure the global function exists.
1869 ** A global function must exist in order for name resolution to work
1870 ** properly.
1871 */
1872 int sqlite3_overload_function(
1873   sqlite3 *db,
1874   const char *zName,
1875   int nArg
1876 ){
1877   int rc = SQLITE_OK;
1878 
1879 #ifdef SQLITE_ENABLE_API_ARMOR
1880   if( !sqlite3SafetyCheckOk(db) || zName==0 || nArg<-2 ){
1881     return SQLITE_MISUSE_BKPT;
1882   }
1883 #endif
1884   sqlite3_mutex_enter(db->mutex);
1885   if( sqlite3FindFunction(db, zName, nArg, SQLITE_UTF8, 0)==0 ){
1886     rc = sqlite3CreateFunc(db, zName, nArg, SQLITE_UTF8,
1887                            0, sqlite3InvalidFunction, 0, 0, 0);
1888   }
1889   rc = sqlite3ApiExit(db, rc);
1890   sqlite3_mutex_leave(db->mutex);
1891   return rc;
1892 }
1893 
1894 #ifndef SQLITE_OMIT_TRACE
1895 /*
1896 ** Register a trace function.  The pArg from the previously registered trace
1897 ** is returned.
1898 **
1899 ** A NULL trace function means that no tracing is executes.  A non-NULL
1900 ** trace is a pointer to a function that is invoked at the start of each
1901 ** SQL statement.
1902 */
1903 #ifndef SQLITE_OMIT_DEPRECATED
1904 void *sqlite3_trace(sqlite3 *db, void(*xTrace)(void*,const char*), void *pArg){
1905   void *pOld;
1906 
1907 #ifdef SQLITE_ENABLE_API_ARMOR
1908   if( !sqlite3SafetyCheckOk(db) ){
1909     (void)SQLITE_MISUSE_BKPT;
1910     return 0;
1911   }
1912 #endif
1913   sqlite3_mutex_enter(db->mutex);
1914   pOld = db->pTraceArg;
1915   db->mTrace = xTrace ? SQLITE_TRACE_LEGACY : 0;
1916   db->xTrace = (int(*)(u32,void*,void*,void*))xTrace;
1917   db->pTraceArg = pArg;
1918   sqlite3_mutex_leave(db->mutex);
1919   return pOld;
1920 }
1921 #endif /* SQLITE_OMIT_DEPRECATED */
1922 
1923 /* Register a trace callback using the version-2 interface.
1924 */
1925 int sqlite3_trace_v2(
1926   sqlite3 *db,                               /* Trace this connection */
1927   unsigned mTrace,                           /* Mask of events to be traced */
1928   int(*xTrace)(unsigned,void*,void*,void*),  /* Callback to invoke */
1929   void *pArg                                 /* Context */
1930 ){
1931 #ifdef SQLITE_ENABLE_API_ARMOR
1932   if( !sqlite3SafetyCheckOk(db) ){
1933     return SQLITE_MISUSE_BKPT;
1934   }
1935 #endif
1936   sqlite3_mutex_enter(db->mutex);
1937   if( mTrace==0 ) xTrace = 0;
1938   if( xTrace==0 ) mTrace = 0;
1939   db->mTrace = mTrace;
1940   db->xTrace = xTrace;
1941   db->pTraceArg = pArg;
1942   sqlite3_mutex_leave(db->mutex);
1943   return SQLITE_OK;
1944 }
1945 
1946 #ifndef SQLITE_OMIT_DEPRECATED
1947 /*
1948 ** Register a profile function.  The pArg from the previously registered
1949 ** profile function is returned.
1950 **
1951 ** A NULL profile function means that no profiling is executes.  A non-NULL
1952 ** profile is a pointer to a function that is invoked at the conclusion of
1953 ** each SQL statement that is run.
1954 */
1955 void *sqlite3_profile(
1956   sqlite3 *db,
1957   void (*xProfile)(void*,const char*,sqlite_uint64),
1958   void *pArg
1959 ){
1960   void *pOld;
1961 
1962 #ifdef SQLITE_ENABLE_API_ARMOR
1963   if( !sqlite3SafetyCheckOk(db) ){
1964     (void)SQLITE_MISUSE_BKPT;
1965     return 0;
1966   }
1967 #endif
1968   sqlite3_mutex_enter(db->mutex);
1969   pOld = db->pProfileArg;
1970   db->xProfile = xProfile;
1971   db->pProfileArg = pArg;
1972   sqlite3_mutex_leave(db->mutex);
1973   return pOld;
1974 }
1975 #endif /* SQLITE_OMIT_DEPRECATED */
1976 #endif /* SQLITE_OMIT_TRACE */
1977 
1978 /*
1979 ** Register a function to be invoked when a transaction commits.
1980 ** If the invoked function returns non-zero, then the commit becomes a
1981 ** rollback.
1982 */
1983 void *sqlite3_commit_hook(
1984   sqlite3 *db,              /* Attach the hook to this database */
1985   int (*xCallback)(void*),  /* Function to invoke on each commit */
1986   void *pArg                /* Argument to the function */
1987 ){
1988   void *pOld;
1989 
1990 #ifdef SQLITE_ENABLE_API_ARMOR
1991   if( !sqlite3SafetyCheckOk(db) ){
1992     (void)SQLITE_MISUSE_BKPT;
1993     return 0;
1994   }
1995 #endif
1996   sqlite3_mutex_enter(db->mutex);
1997   pOld = db->pCommitArg;
1998   db->xCommitCallback = xCallback;
1999   db->pCommitArg = pArg;
2000   sqlite3_mutex_leave(db->mutex);
2001   return pOld;
2002 }
2003 
2004 /*
2005 ** Register a callback to be invoked each time a row is updated,
2006 ** inserted or deleted using this database connection.
2007 */
2008 void *sqlite3_update_hook(
2009   sqlite3 *db,              /* Attach the hook to this database */
2010   void (*xCallback)(void*,int,char const *,char const *,sqlite_int64),
2011   void *pArg                /* Argument to the function */
2012 ){
2013   void *pRet;
2014 
2015 #ifdef SQLITE_ENABLE_API_ARMOR
2016   if( !sqlite3SafetyCheckOk(db) ){
2017     (void)SQLITE_MISUSE_BKPT;
2018     return 0;
2019   }
2020 #endif
2021   sqlite3_mutex_enter(db->mutex);
2022   pRet = db->pUpdateArg;
2023   db->xUpdateCallback = xCallback;
2024   db->pUpdateArg = pArg;
2025   sqlite3_mutex_leave(db->mutex);
2026   return pRet;
2027 }
2028 
2029 /*
2030 ** Register a callback to be invoked each time a transaction is rolled
2031 ** back by this database connection.
2032 */
2033 void *sqlite3_rollback_hook(
2034   sqlite3 *db,              /* Attach the hook to this database */
2035   void (*xCallback)(void*), /* Callback function */
2036   void *pArg                /* Argument to the function */
2037 ){
2038   void *pRet;
2039 
2040 #ifdef SQLITE_ENABLE_API_ARMOR
2041   if( !sqlite3SafetyCheckOk(db) ){
2042     (void)SQLITE_MISUSE_BKPT;
2043     return 0;
2044   }
2045 #endif
2046   sqlite3_mutex_enter(db->mutex);
2047   pRet = db->pRollbackArg;
2048   db->xRollbackCallback = xCallback;
2049   db->pRollbackArg = pArg;
2050   sqlite3_mutex_leave(db->mutex);
2051   return pRet;
2052 }
2053 
2054 #ifdef SQLITE_ENABLE_PREUPDATE_HOOK
2055 /*
2056 ** Register a callback to be invoked each time a row is updated,
2057 ** inserted or deleted using this database connection.
2058 */
2059 void *sqlite3_preupdate_hook(
2060   sqlite3 *db,              /* Attach the hook to this database */
2061   void(*xCallback)(         /* Callback function */
2062     void*,sqlite3*,int,char const*,char const*,sqlite3_int64,sqlite3_int64),
2063   void *pArg                /* First callback argument */
2064 ){
2065   void *pRet;
2066   sqlite3_mutex_enter(db->mutex);
2067   pRet = db->pPreUpdateArg;
2068   db->xPreUpdateCallback = xCallback;
2069   db->pPreUpdateArg = pArg;
2070   sqlite3_mutex_leave(db->mutex);
2071   return pRet;
2072 }
2073 #endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
2074 
2075 #ifndef SQLITE_OMIT_WAL
2076 /*
2077 ** The sqlite3_wal_hook() callback registered by sqlite3_wal_autocheckpoint().
2078 ** Invoke sqlite3_wal_checkpoint if the number of frames in the log file
2079 ** is greater than sqlite3.pWalArg cast to an integer (the value configured by
2080 ** wal_autocheckpoint()).
2081 */
2082 int sqlite3WalDefaultHook(
2083   void *pClientData,     /* Argument */
2084   sqlite3 *db,           /* Connection */
2085   const char *zDb,       /* Database */
2086   int nFrame             /* Size of WAL */
2087 ){
2088   if( nFrame>=SQLITE_PTR_TO_INT(pClientData) ){
2089     sqlite3BeginBenignMalloc();
2090     sqlite3_wal_checkpoint(db, zDb);
2091     sqlite3EndBenignMalloc();
2092   }
2093   return SQLITE_OK;
2094 }
2095 #endif /* SQLITE_OMIT_WAL */
2096 
2097 /*
2098 ** Configure an sqlite3_wal_hook() callback to automatically checkpoint
2099 ** a database after committing a transaction if there are nFrame or
2100 ** more frames in the log file. Passing zero or a negative value as the
2101 ** nFrame parameter disables automatic checkpoints entirely.
2102 **
2103 ** The callback registered by this function replaces any existing callback
2104 ** registered using sqlite3_wal_hook(). Likewise, registering a callback
2105 ** using sqlite3_wal_hook() disables the automatic checkpoint mechanism
2106 ** configured by this function.
2107 */
2108 int sqlite3_wal_autocheckpoint(sqlite3 *db, int nFrame){
2109 #ifdef SQLITE_OMIT_WAL
2110   UNUSED_PARAMETER(db);
2111   UNUSED_PARAMETER(nFrame);
2112 #else
2113 #ifdef SQLITE_ENABLE_API_ARMOR
2114   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
2115 #endif
2116   if( nFrame>0 ){
2117     sqlite3_wal_hook(db, sqlite3WalDefaultHook, SQLITE_INT_TO_PTR(nFrame));
2118   }else{
2119     sqlite3_wal_hook(db, 0, 0);
2120   }
2121 #endif
2122   return SQLITE_OK;
2123 }
2124 
2125 /*
2126 ** Register a callback to be invoked each time a transaction is written
2127 ** into the write-ahead-log by this database connection.
2128 */
2129 void *sqlite3_wal_hook(
2130   sqlite3 *db,                    /* Attach the hook to this db handle */
2131   int(*xCallback)(void *, sqlite3*, const char*, int),
2132   void *pArg                      /* First argument passed to xCallback() */
2133 ){
2134 #ifndef SQLITE_OMIT_WAL
2135   void *pRet;
2136 #ifdef SQLITE_ENABLE_API_ARMOR
2137   if( !sqlite3SafetyCheckOk(db) ){
2138     (void)SQLITE_MISUSE_BKPT;
2139     return 0;
2140   }
2141 #endif
2142   sqlite3_mutex_enter(db->mutex);
2143   pRet = db->pWalArg;
2144   db->xWalCallback = xCallback;
2145   db->pWalArg = pArg;
2146   sqlite3_mutex_leave(db->mutex);
2147   return pRet;
2148 #else
2149   return 0;
2150 #endif
2151 }
2152 
2153 /*
2154 ** Checkpoint database zDb.
2155 */
2156 int sqlite3_wal_checkpoint_v2(
2157   sqlite3 *db,                    /* Database handle */
2158   const char *zDb,                /* Name of attached database (or NULL) */
2159   int eMode,                      /* SQLITE_CHECKPOINT_* value */
2160   int *pnLog,                     /* OUT: Size of WAL log in frames */
2161   int *pnCkpt                     /* OUT: Total number of frames checkpointed */
2162 ){
2163 #ifdef SQLITE_OMIT_WAL
2164   return SQLITE_OK;
2165 #else
2166   int rc;                         /* Return code */
2167   int iDb = SQLITE_MAX_ATTACHED;  /* sqlite3.aDb[] index of db to checkpoint */
2168 
2169 #ifdef SQLITE_ENABLE_API_ARMOR
2170   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
2171 #endif
2172 
2173   /* Initialize the output variables to -1 in case an error occurs. */
2174   if( pnLog ) *pnLog = -1;
2175   if( pnCkpt ) *pnCkpt = -1;
2176 
2177   assert( SQLITE_CHECKPOINT_PASSIVE==0 );
2178   assert( SQLITE_CHECKPOINT_FULL==1 );
2179   assert( SQLITE_CHECKPOINT_RESTART==2 );
2180   assert( SQLITE_CHECKPOINT_TRUNCATE==3 );
2181   if( eMode<SQLITE_CHECKPOINT_PASSIVE || eMode>SQLITE_CHECKPOINT_TRUNCATE ){
2182     /* EVIDENCE-OF: R-03996-12088 The M parameter must be a valid checkpoint
2183     ** mode: */
2184     return SQLITE_MISUSE;
2185   }
2186 
2187   sqlite3_mutex_enter(db->mutex);
2188   if( zDb && zDb[0] ){
2189     iDb = sqlite3FindDbName(db, zDb);
2190   }
2191   if( iDb<0 ){
2192     rc = SQLITE_ERROR;
2193     sqlite3ErrorWithMsg(db, SQLITE_ERROR, "unknown database: %s", zDb);
2194   }else{
2195     db->busyHandler.nBusy = 0;
2196     rc = sqlite3Checkpoint(db, iDb, eMode, pnLog, pnCkpt);
2197     sqlite3Error(db, rc);
2198   }
2199   rc = sqlite3ApiExit(db, rc);
2200 
2201   /* If there are no active statements, clear the interrupt flag at this
2202   ** point.  */
2203   if( db->nVdbeActive==0 ){
2204     db->u1.isInterrupted = 0;
2205   }
2206 
2207   sqlite3_mutex_leave(db->mutex);
2208   return rc;
2209 #endif
2210 }
2211 
2212 
2213 /*
2214 ** Checkpoint database zDb. If zDb is NULL, or if the buffer zDb points
2215 ** to contains a zero-length string, all attached databases are
2216 ** checkpointed.
2217 */
2218 int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb){
2219   /* EVIDENCE-OF: R-41613-20553 The sqlite3_wal_checkpoint(D,X) is equivalent to
2220   ** sqlite3_wal_checkpoint_v2(D,X,SQLITE_CHECKPOINT_PASSIVE,0,0). */
2221   return sqlite3_wal_checkpoint_v2(db,zDb,SQLITE_CHECKPOINT_PASSIVE,0,0);
2222 }
2223 
2224 #ifndef SQLITE_OMIT_WAL
2225 /*
2226 ** Run a checkpoint on database iDb. This is a no-op if database iDb is
2227 ** not currently open in WAL mode.
2228 **
2229 ** If a transaction is open on the database being checkpointed, this
2230 ** function returns SQLITE_LOCKED and a checkpoint is not attempted. If
2231 ** an error occurs while running the checkpoint, an SQLite error code is
2232 ** returned (i.e. SQLITE_IOERR). Otherwise, SQLITE_OK.
2233 **
2234 ** The mutex on database handle db should be held by the caller. The mutex
2235 ** associated with the specific b-tree being checkpointed is taken by
2236 ** this function while the checkpoint is running.
2237 **
2238 ** If iDb is passed SQLITE_MAX_ATTACHED, then all attached databases are
2239 ** checkpointed. If an error is encountered it is returned immediately -
2240 ** no attempt is made to checkpoint any remaining databases.
2241 **
2242 ** Parameter eMode is one of SQLITE_CHECKPOINT_PASSIVE, FULL, RESTART
2243 ** or TRUNCATE.
2244 */
2245 int sqlite3Checkpoint(sqlite3 *db, int iDb, int eMode, int *pnLog, int *pnCkpt){
2246   int rc = SQLITE_OK;             /* Return code */
2247   int i;                          /* Used to iterate through attached dbs */
2248   int bBusy = 0;                  /* True if SQLITE_BUSY has been encountered */
2249 
2250   assert( sqlite3_mutex_held(db->mutex) );
2251   assert( !pnLog || *pnLog==-1 );
2252   assert( !pnCkpt || *pnCkpt==-1 );
2253 
2254   for(i=0; i<db->nDb && rc==SQLITE_OK; i++){
2255     if( i==iDb || iDb==SQLITE_MAX_ATTACHED ){
2256       rc = sqlite3BtreeCheckpoint(db->aDb[i].pBt, eMode, pnLog, pnCkpt);
2257       pnLog = 0;
2258       pnCkpt = 0;
2259       if( rc==SQLITE_BUSY ){
2260         bBusy = 1;
2261         rc = SQLITE_OK;
2262       }
2263     }
2264   }
2265 
2266   return (rc==SQLITE_OK && bBusy) ? SQLITE_BUSY : rc;
2267 }
2268 #endif /* SQLITE_OMIT_WAL */
2269 
2270 /*
2271 ** This function returns true if main-memory should be used instead of
2272 ** a temporary file for transient pager files and statement journals.
2273 ** The value returned depends on the value of db->temp_store (runtime
2274 ** parameter) and the compile time value of SQLITE_TEMP_STORE. The
2275 ** following table describes the relationship between these two values
2276 ** and this functions return value.
2277 **
2278 **   SQLITE_TEMP_STORE     db->temp_store     Location of temporary database
2279 **   -----------------     --------------     ------------------------------
2280 **   0                     any                file      (return 0)
2281 **   1                     1                  file      (return 0)
2282 **   1                     2                  memory    (return 1)
2283 **   1                     0                  file      (return 0)
2284 **   2                     1                  file      (return 0)
2285 **   2                     2                  memory    (return 1)
2286 **   2                     0                  memory    (return 1)
2287 **   3                     any                memory    (return 1)
2288 */
2289 int sqlite3TempInMemory(const sqlite3 *db){
2290 #if SQLITE_TEMP_STORE==1
2291   return ( db->temp_store==2 );
2292 #endif
2293 #if SQLITE_TEMP_STORE==2
2294   return ( db->temp_store!=1 );
2295 #endif
2296 #if SQLITE_TEMP_STORE==3
2297   UNUSED_PARAMETER(db);
2298   return 1;
2299 #endif
2300 #if SQLITE_TEMP_STORE<1 || SQLITE_TEMP_STORE>3
2301   UNUSED_PARAMETER(db);
2302   return 0;
2303 #endif
2304 }
2305 
2306 /*
2307 ** Return UTF-8 encoded English language explanation of the most recent
2308 ** error.
2309 */
2310 const char *sqlite3_errmsg(sqlite3 *db){
2311   const char *z;
2312   if( !db ){
2313     return sqlite3ErrStr(SQLITE_NOMEM_BKPT);
2314   }
2315   if( !sqlite3SafetyCheckSickOrOk(db) ){
2316     return sqlite3ErrStr(SQLITE_MISUSE_BKPT);
2317   }
2318   sqlite3_mutex_enter(db->mutex);
2319   if( db->mallocFailed ){
2320     z = sqlite3ErrStr(SQLITE_NOMEM_BKPT);
2321   }else{
2322     testcase( db->pErr==0 );
2323     z = (char*)sqlite3_value_text(db->pErr);
2324     assert( !db->mallocFailed );
2325     if( z==0 ){
2326       z = sqlite3ErrStr(db->errCode);
2327     }
2328   }
2329   sqlite3_mutex_leave(db->mutex);
2330   return z;
2331 }
2332 
2333 #ifndef SQLITE_OMIT_UTF16
2334 /*
2335 ** Return UTF-16 encoded English language explanation of the most recent
2336 ** error.
2337 */
2338 const void *sqlite3_errmsg16(sqlite3 *db){
2339   static const u16 outOfMem[] = {
2340     'o', 'u', 't', ' ', 'o', 'f', ' ', 'm', 'e', 'm', 'o', 'r', 'y', 0
2341   };
2342   static const u16 misuse[] = {
2343     'b', 'a', 'd', ' ', 'p', 'a', 'r', 'a', 'm', 'e', 't', 'e', 'r', ' ',
2344     'o', 'r', ' ', 'o', 't', 'h', 'e', 'r', ' ', 'A', 'P', 'I', ' ',
2345     'm', 'i', 's', 'u', 's', 'e', 0
2346   };
2347 
2348   const void *z;
2349   if( !db ){
2350     return (void *)outOfMem;
2351   }
2352   if( !sqlite3SafetyCheckSickOrOk(db) ){
2353     return (void *)misuse;
2354   }
2355   sqlite3_mutex_enter(db->mutex);
2356   if( db->mallocFailed ){
2357     z = (void *)outOfMem;
2358   }else{
2359     z = sqlite3_value_text16(db->pErr);
2360     if( z==0 ){
2361       sqlite3ErrorWithMsg(db, db->errCode, sqlite3ErrStr(db->errCode));
2362       z = sqlite3_value_text16(db->pErr);
2363     }
2364     /* A malloc() may have failed within the call to sqlite3_value_text16()
2365     ** above. If this is the case, then the db->mallocFailed flag needs to
2366     ** be cleared before returning. Do this directly, instead of via
2367     ** sqlite3ApiExit(), to avoid setting the database handle error message.
2368     */
2369     sqlite3OomClear(db);
2370   }
2371   sqlite3_mutex_leave(db->mutex);
2372   return z;
2373 }
2374 #endif /* SQLITE_OMIT_UTF16 */
2375 
2376 /*
2377 ** Return the most recent error code generated by an SQLite routine. If NULL is
2378 ** passed to this function, we assume a malloc() failed during sqlite3_open().
2379 */
2380 int sqlite3_errcode(sqlite3 *db){
2381   if( db && !sqlite3SafetyCheckSickOrOk(db) ){
2382     return SQLITE_MISUSE_BKPT;
2383   }
2384   if( !db || db->mallocFailed ){
2385     return SQLITE_NOMEM_BKPT;
2386   }
2387   return db->errCode & db->errMask;
2388 }
2389 int sqlite3_extended_errcode(sqlite3 *db){
2390   if( db && !sqlite3SafetyCheckSickOrOk(db) ){
2391     return SQLITE_MISUSE_BKPT;
2392   }
2393   if( !db || db->mallocFailed ){
2394     return SQLITE_NOMEM_BKPT;
2395   }
2396   return db->errCode;
2397 }
2398 int sqlite3_system_errno(sqlite3 *db){
2399   return db ? db->iSysErrno : 0;
2400 }
2401 
2402 /*
2403 ** Return a string that describes the kind of error specified in the
2404 ** argument.  For now, this simply calls the internal sqlite3ErrStr()
2405 ** function.
2406 */
2407 const char *sqlite3_errstr(int rc){
2408   return sqlite3ErrStr(rc);
2409 }
2410 
2411 /*
2412 ** Create a new collating function for database "db".  The name is zName
2413 ** and the encoding is enc.
2414 */
2415 static int createCollation(
2416   sqlite3* db,
2417   const char *zName,
2418   u8 enc,
2419   void* pCtx,
2420   int(*xCompare)(void*,int,const void*,int,const void*),
2421   void(*xDel)(void*)
2422 ){
2423   CollSeq *pColl;
2424   int enc2;
2425 
2426   assert( sqlite3_mutex_held(db->mutex) );
2427 
2428   /* If SQLITE_UTF16 is specified as the encoding type, transform this
2429   ** to one of SQLITE_UTF16LE or SQLITE_UTF16BE using the
2430   ** SQLITE_UTF16NATIVE macro. SQLITE_UTF16 is not used internally.
2431   */
2432   enc2 = enc;
2433   testcase( enc2==SQLITE_UTF16 );
2434   testcase( enc2==SQLITE_UTF16_ALIGNED );
2435   if( enc2==SQLITE_UTF16 || enc2==SQLITE_UTF16_ALIGNED ){
2436     enc2 = SQLITE_UTF16NATIVE;
2437   }
2438   if( enc2<SQLITE_UTF8 || enc2>SQLITE_UTF16BE ){
2439     return SQLITE_MISUSE_BKPT;
2440   }
2441 
2442   /* Check if this call is removing or replacing an existing collation
2443   ** sequence. If so, and there are active VMs, return busy. If there
2444   ** are no active VMs, invalidate any pre-compiled statements.
2445   */
2446   pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, 0);
2447   if( pColl && pColl->xCmp ){
2448     if( db->nVdbeActive ){
2449       sqlite3ErrorWithMsg(db, SQLITE_BUSY,
2450         "unable to delete/modify collation sequence due to active statements");
2451       return SQLITE_BUSY;
2452     }
2453     sqlite3ExpirePreparedStatements(db);
2454 
2455     /* If collation sequence pColl was created directly by a call to
2456     ** sqlite3_create_collation, and not generated by synthCollSeq(),
2457     ** then any copies made by synthCollSeq() need to be invalidated.
2458     ** Also, collation destructor - CollSeq.xDel() - function may need
2459     ** to be called.
2460     */
2461     if( (pColl->enc & ~SQLITE_UTF16_ALIGNED)==enc2 ){
2462       CollSeq *aColl = sqlite3HashFind(&db->aCollSeq, zName);
2463       int j;
2464       for(j=0; j<3; j++){
2465         CollSeq *p = &aColl[j];
2466         if( p->enc==pColl->enc ){
2467           if( p->xDel ){
2468             p->xDel(p->pUser);
2469           }
2470           p->xCmp = 0;
2471         }
2472       }
2473     }
2474   }
2475 
2476   pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, 1);
2477   if( pColl==0 ) return SQLITE_NOMEM_BKPT;
2478   pColl->xCmp = xCompare;
2479   pColl->pUser = pCtx;
2480   pColl->xDel = xDel;
2481   pColl->enc = (u8)(enc2 | (enc & SQLITE_UTF16_ALIGNED));
2482   sqlite3Error(db, SQLITE_OK);
2483   return SQLITE_OK;
2484 }
2485 
2486 
2487 /*
2488 ** This array defines hard upper bounds on limit values.  The
2489 ** initializer must be kept in sync with the SQLITE_LIMIT_*
2490 ** #defines in sqlite3.h.
2491 */
2492 static const int aHardLimit[] = {
2493   SQLITE_MAX_LENGTH,
2494   SQLITE_MAX_SQL_LENGTH,
2495   SQLITE_MAX_COLUMN,
2496   SQLITE_MAX_EXPR_DEPTH,
2497   SQLITE_MAX_COMPOUND_SELECT,
2498   SQLITE_MAX_VDBE_OP,
2499   SQLITE_MAX_FUNCTION_ARG,
2500   SQLITE_MAX_ATTACHED,
2501   SQLITE_MAX_LIKE_PATTERN_LENGTH,
2502   SQLITE_MAX_VARIABLE_NUMBER,      /* IMP: R-38091-32352 */
2503   SQLITE_MAX_TRIGGER_DEPTH,
2504   SQLITE_MAX_WORKER_THREADS,
2505 };
2506 
2507 /*
2508 ** Make sure the hard limits are set to reasonable values
2509 */
2510 #if SQLITE_MAX_LENGTH<100
2511 # error SQLITE_MAX_LENGTH must be at least 100
2512 #endif
2513 #if SQLITE_MAX_SQL_LENGTH<100
2514 # error SQLITE_MAX_SQL_LENGTH must be at least 100
2515 #endif
2516 #if SQLITE_MAX_SQL_LENGTH>SQLITE_MAX_LENGTH
2517 # error SQLITE_MAX_SQL_LENGTH must not be greater than SQLITE_MAX_LENGTH
2518 #endif
2519 #if SQLITE_MAX_COMPOUND_SELECT<2
2520 # error SQLITE_MAX_COMPOUND_SELECT must be at least 2
2521 #endif
2522 #if SQLITE_MAX_VDBE_OP<40
2523 # error SQLITE_MAX_VDBE_OP must be at least 40
2524 #endif
2525 #if SQLITE_MAX_FUNCTION_ARG<0 || SQLITE_MAX_FUNCTION_ARG>127
2526 # error SQLITE_MAX_FUNCTION_ARG must be between 0 and 127
2527 #endif
2528 #if SQLITE_MAX_ATTACHED<0 || SQLITE_MAX_ATTACHED>125
2529 # error SQLITE_MAX_ATTACHED must be between 0 and 125
2530 #endif
2531 #if SQLITE_MAX_LIKE_PATTERN_LENGTH<1
2532 # error SQLITE_MAX_LIKE_PATTERN_LENGTH must be at least 1
2533 #endif
2534 #if SQLITE_MAX_COLUMN>32767
2535 # error SQLITE_MAX_COLUMN must not exceed 32767
2536 #endif
2537 #if SQLITE_MAX_TRIGGER_DEPTH<1
2538 # error SQLITE_MAX_TRIGGER_DEPTH must be at least 1
2539 #endif
2540 #if SQLITE_MAX_WORKER_THREADS<0 || SQLITE_MAX_WORKER_THREADS>50
2541 # error SQLITE_MAX_WORKER_THREADS must be between 0 and 50
2542 #endif
2543 
2544 
2545 /*
2546 ** Change the value of a limit.  Report the old value.
2547 ** If an invalid limit index is supplied, report -1.
2548 ** Make no changes but still report the old value if the
2549 ** new limit is negative.
2550 **
2551 ** A new lower limit does not shrink existing constructs.
2552 ** It merely prevents new constructs that exceed the limit
2553 ** from forming.
2554 */
2555 int sqlite3_limit(sqlite3 *db, int limitId, int newLimit){
2556   int oldLimit;
2557 
2558 #ifdef SQLITE_ENABLE_API_ARMOR
2559   if( !sqlite3SafetyCheckOk(db) ){
2560     (void)SQLITE_MISUSE_BKPT;
2561     return -1;
2562   }
2563 #endif
2564 
2565   /* EVIDENCE-OF: R-30189-54097 For each limit category SQLITE_LIMIT_NAME
2566   ** there is a hard upper bound set at compile-time by a C preprocessor
2567   ** macro called SQLITE_MAX_NAME. (The "_LIMIT_" in the name is changed to
2568   ** "_MAX_".)
2569   */
2570   assert( aHardLimit[SQLITE_LIMIT_LENGTH]==SQLITE_MAX_LENGTH );
2571   assert( aHardLimit[SQLITE_LIMIT_SQL_LENGTH]==SQLITE_MAX_SQL_LENGTH );
2572   assert( aHardLimit[SQLITE_LIMIT_COLUMN]==SQLITE_MAX_COLUMN );
2573   assert( aHardLimit[SQLITE_LIMIT_EXPR_DEPTH]==SQLITE_MAX_EXPR_DEPTH );
2574   assert( aHardLimit[SQLITE_LIMIT_COMPOUND_SELECT]==SQLITE_MAX_COMPOUND_SELECT);
2575   assert( aHardLimit[SQLITE_LIMIT_VDBE_OP]==SQLITE_MAX_VDBE_OP );
2576   assert( aHardLimit[SQLITE_LIMIT_FUNCTION_ARG]==SQLITE_MAX_FUNCTION_ARG );
2577   assert( aHardLimit[SQLITE_LIMIT_ATTACHED]==SQLITE_MAX_ATTACHED );
2578   assert( aHardLimit[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]==
2579                                                SQLITE_MAX_LIKE_PATTERN_LENGTH );
2580   assert( aHardLimit[SQLITE_LIMIT_VARIABLE_NUMBER]==SQLITE_MAX_VARIABLE_NUMBER);
2581   assert( aHardLimit[SQLITE_LIMIT_TRIGGER_DEPTH]==SQLITE_MAX_TRIGGER_DEPTH );
2582   assert( aHardLimit[SQLITE_LIMIT_WORKER_THREADS]==SQLITE_MAX_WORKER_THREADS );
2583   assert( SQLITE_LIMIT_WORKER_THREADS==(SQLITE_N_LIMIT-1) );
2584 
2585 
2586   if( limitId<0 || limitId>=SQLITE_N_LIMIT ){
2587     return -1;
2588   }
2589   oldLimit = db->aLimit[limitId];
2590   if( newLimit>=0 ){                   /* IMP: R-52476-28732 */
2591     if( newLimit>aHardLimit[limitId] ){
2592       newLimit = aHardLimit[limitId];  /* IMP: R-51463-25634 */
2593     }
2594     db->aLimit[limitId] = newLimit;
2595   }
2596   return oldLimit;                     /* IMP: R-53341-35419 */
2597 }
2598 
2599 /*
2600 ** This function is used to parse both URIs and non-URI filenames passed by the
2601 ** user to API functions sqlite3_open() or sqlite3_open_v2(), and for database
2602 ** URIs specified as part of ATTACH statements.
2603 **
2604 ** The first argument to this function is the name of the VFS to use (or
2605 ** a NULL to signify the default VFS) if the URI does not contain a "vfs=xxx"
2606 ** query parameter. The second argument contains the URI (or non-URI filename)
2607 ** itself. When this function is called the *pFlags variable should contain
2608 ** the default flags to open the database handle with. The value stored in
2609 ** *pFlags may be updated before returning if the URI filename contains
2610 ** "cache=xxx" or "mode=xxx" query parameters.
2611 **
2612 ** If successful, SQLITE_OK is returned. In this case *ppVfs is set to point to
2613 ** the VFS that should be used to open the database file. *pzFile is set to
2614 ** point to a buffer containing the name of the file to open. It is the
2615 ** responsibility of the caller to eventually call sqlite3_free() to release
2616 ** this buffer.
2617 **
2618 ** If an error occurs, then an SQLite error code is returned and *pzErrMsg
2619 ** may be set to point to a buffer containing an English language error
2620 ** message. It is the responsibility of the caller to eventually release
2621 ** this buffer by calling sqlite3_free().
2622 */
2623 int sqlite3ParseUri(
2624   const char *zDefaultVfs,        /* VFS to use if no "vfs=xxx" query option */
2625   const char *zUri,               /* Nul-terminated URI to parse */
2626   unsigned int *pFlags,           /* IN/OUT: SQLITE_OPEN_XXX flags */
2627   sqlite3_vfs **ppVfs,            /* OUT: VFS to use */
2628   char **pzFile,                  /* OUT: Filename component of URI */
2629   char **pzErrMsg                 /* OUT: Error message (if rc!=SQLITE_OK) */
2630 ){
2631   int rc = SQLITE_OK;
2632   unsigned int flags = *pFlags;
2633   const char *zVfs = zDefaultVfs;
2634   char *zFile;
2635   char c;
2636   int nUri = sqlite3Strlen30(zUri);
2637 
2638   assert( *pzErrMsg==0 );
2639 
2640   if( ((flags & SQLITE_OPEN_URI)             /* IMP: R-48725-32206 */
2641             || sqlite3GlobalConfig.bOpenUri) /* IMP: R-51689-46548 */
2642    && nUri>=5 && memcmp(zUri, "file:", 5)==0 /* IMP: R-57884-37496 */
2643   ){
2644     char *zOpt;
2645     int eState;                   /* Parser state when parsing URI */
2646     int iIn;                      /* Input character index */
2647     int iOut = 0;                 /* Output character index */
2648     u64 nByte = nUri+2;           /* Bytes of space to allocate */
2649 
2650     /* Make sure the SQLITE_OPEN_URI flag is set to indicate to the VFS xOpen
2651     ** method that there may be extra parameters following the file-name.  */
2652     flags |= SQLITE_OPEN_URI;
2653 
2654     for(iIn=0; iIn<nUri; iIn++) nByte += (zUri[iIn]=='&');
2655     zFile = sqlite3_malloc64(nByte);
2656     if( !zFile ) return SQLITE_NOMEM_BKPT;
2657 
2658     iIn = 5;
2659 #ifdef SQLITE_ALLOW_URI_AUTHORITY
2660     if( strncmp(zUri+5, "///", 3)==0 ){
2661       iIn = 7;
2662       /* The following condition causes URIs with five leading / characters
2663       ** like file://///host/path to be converted into UNCs like //host/path.
2664       ** The correct URI for that UNC has only two or four leading / characters
2665       ** file://host/path or file:////host/path.  But 5 leading slashes is a
2666       ** common error, we are told, so we handle it as a special case. */
2667       if( strncmp(zUri+7, "///", 3)==0 ){ iIn++; }
2668     }else if( strncmp(zUri+5, "//localhost/", 12)==0 ){
2669       iIn = 16;
2670     }
2671 #else
2672     /* Discard the scheme and authority segments of the URI. */
2673     if( zUri[5]=='/' && zUri[6]=='/' ){
2674       iIn = 7;
2675       while( zUri[iIn] && zUri[iIn]!='/' ) iIn++;
2676       if( iIn!=7 && (iIn!=16 || memcmp("localhost", &zUri[7], 9)) ){
2677         *pzErrMsg = sqlite3_mprintf("invalid uri authority: %.*s",
2678             iIn-7, &zUri[7]);
2679         rc = SQLITE_ERROR;
2680         goto parse_uri_out;
2681       }
2682     }
2683 #endif
2684 
2685     /* Copy the filename and any query parameters into the zFile buffer.
2686     ** Decode %HH escape codes along the way.
2687     **
2688     ** Within this loop, variable eState may be set to 0, 1 or 2, depending
2689     ** on the parsing context. As follows:
2690     **
2691     **   0: Parsing file-name.
2692     **   1: Parsing name section of a name=value query parameter.
2693     **   2: Parsing value section of a name=value query parameter.
2694     */
2695     eState = 0;
2696     while( (c = zUri[iIn])!=0 && c!='#' ){
2697       iIn++;
2698       if( c=='%'
2699        && sqlite3Isxdigit(zUri[iIn])
2700        && sqlite3Isxdigit(zUri[iIn+1])
2701       ){
2702         int octet = (sqlite3HexToInt(zUri[iIn++]) << 4);
2703         octet += sqlite3HexToInt(zUri[iIn++]);
2704 
2705         assert( octet>=0 && octet<256 );
2706         if( octet==0 ){
2707 #ifndef SQLITE_ENABLE_URI_00_ERROR
2708           /* This branch is taken when "%00" appears within the URI. In this
2709           ** case we ignore all text in the remainder of the path, name or
2710           ** value currently being parsed. So ignore the current character
2711           ** and skip to the next "?", "=" or "&", as appropriate. */
2712           while( (c = zUri[iIn])!=0 && c!='#'
2713               && (eState!=0 || c!='?')
2714               && (eState!=1 || (c!='=' && c!='&'))
2715               && (eState!=2 || c!='&')
2716           ){
2717             iIn++;
2718           }
2719           continue;
2720 #else
2721           /* If ENABLE_URI_00_ERROR is defined, "%00" in a URI is an error. */
2722           *pzErrMsg = sqlite3_mprintf("unexpected %%00 in uri");
2723           rc = SQLITE_ERROR;
2724           goto parse_uri_out;
2725 #endif
2726         }
2727         c = octet;
2728       }else if( eState==1 && (c=='&' || c=='=') ){
2729         if( zFile[iOut-1]==0 ){
2730           /* An empty option name. Ignore this option altogether. */
2731           while( zUri[iIn] && zUri[iIn]!='#' && zUri[iIn-1]!='&' ) iIn++;
2732           continue;
2733         }
2734         if( c=='&' ){
2735           zFile[iOut++] = '\0';
2736         }else{
2737           eState = 2;
2738         }
2739         c = 0;
2740       }else if( (eState==0 && c=='?') || (eState==2 && c=='&') ){
2741         c = 0;
2742         eState = 1;
2743       }
2744       zFile[iOut++] = c;
2745     }
2746     if( eState==1 ) zFile[iOut++] = '\0';
2747     zFile[iOut++] = '\0';
2748     zFile[iOut++] = '\0';
2749 
2750     /* Check if there were any options specified that should be interpreted
2751     ** here. Options that are interpreted here include "vfs" and those that
2752     ** correspond to flags that may be passed to the sqlite3_open_v2()
2753     ** method. */
2754     zOpt = &zFile[sqlite3Strlen30(zFile)+1];
2755     while( zOpt[0] ){
2756       int nOpt = sqlite3Strlen30(zOpt);
2757       char *zVal = &zOpt[nOpt+1];
2758       int nVal = sqlite3Strlen30(zVal);
2759 
2760       if( nOpt==3 && memcmp("vfs", zOpt, 3)==0 ){
2761         zVfs = zVal;
2762       }else{
2763         struct OpenMode {
2764           const char *z;
2765           int mode;
2766         } *aMode = 0;
2767         char *zModeType = 0;
2768         int mask = 0;
2769         int limit = 0;
2770 
2771         if( nOpt==5 && memcmp("cache", zOpt, 5)==0 ){
2772           static struct OpenMode aCacheMode[] = {
2773             { "shared",  SQLITE_OPEN_SHAREDCACHE },
2774             { "private", SQLITE_OPEN_PRIVATECACHE },
2775             { 0, 0 }
2776           };
2777 
2778           mask = SQLITE_OPEN_SHAREDCACHE|SQLITE_OPEN_PRIVATECACHE;
2779           aMode = aCacheMode;
2780           limit = mask;
2781           zModeType = "cache";
2782         }
2783         if( nOpt==4 && memcmp("mode", zOpt, 4)==0 ){
2784           static struct OpenMode aOpenMode[] = {
2785             { "ro",  SQLITE_OPEN_READONLY },
2786             { "rw",  SQLITE_OPEN_READWRITE },
2787             { "rwc", SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE },
2788             { "memory", SQLITE_OPEN_MEMORY },
2789             { 0, 0 }
2790           };
2791 
2792           mask = SQLITE_OPEN_READONLY | SQLITE_OPEN_READWRITE
2793                    | SQLITE_OPEN_CREATE | SQLITE_OPEN_MEMORY;
2794           aMode = aOpenMode;
2795           limit = mask & flags;
2796           zModeType = "access";
2797         }
2798 
2799         if( aMode ){
2800           int i;
2801           int mode = 0;
2802           for(i=0; aMode[i].z; i++){
2803             const char *z = aMode[i].z;
2804             if( nVal==sqlite3Strlen30(z) && 0==memcmp(zVal, z, nVal) ){
2805               mode = aMode[i].mode;
2806               break;
2807             }
2808           }
2809           if( mode==0 ){
2810             *pzErrMsg = sqlite3_mprintf("no such %s mode: %s", zModeType, zVal);
2811             rc = SQLITE_ERROR;
2812             goto parse_uri_out;
2813           }
2814           if( (mode & ~SQLITE_OPEN_MEMORY)>limit ){
2815             *pzErrMsg = sqlite3_mprintf("%s mode not allowed: %s",
2816                                         zModeType, zVal);
2817             rc = SQLITE_PERM;
2818             goto parse_uri_out;
2819           }
2820           flags = (flags & ~mask) | mode;
2821         }
2822       }
2823 
2824       zOpt = &zVal[nVal+1];
2825     }
2826 
2827   }else{
2828     zFile = sqlite3_malloc64(nUri+2);
2829     if( !zFile ) return SQLITE_NOMEM_BKPT;
2830     if( nUri ){
2831       memcpy(zFile, zUri, nUri);
2832     }
2833     zFile[nUri] = '\0';
2834     zFile[nUri+1] = '\0';
2835     flags &= ~SQLITE_OPEN_URI;
2836   }
2837 
2838   *ppVfs = sqlite3_vfs_find(zVfs);
2839   if( *ppVfs==0 ){
2840     *pzErrMsg = sqlite3_mprintf("no such vfs: %s", zVfs);
2841     rc = SQLITE_ERROR;
2842   }
2843  parse_uri_out:
2844   if( rc!=SQLITE_OK ){
2845     sqlite3_free(zFile);
2846     zFile = 0;
2847   }
2848   *pFlags = flags;
2849   *pzFile = zFile;
2850   return rc;
2851 }
2852 
2853 
2854 /*
2855 ** This routine does the work of opening a database on behalf of
2856 ** sqlite3_open() and sqlite3_open16(). The database filename "zFilename"
2857 ** is UTF-8 encoded.
2858 */
2859 static int openDatabase(
2860   const char *zFilename, /* Database filename UTF-8 encoded */
2861   sqlite3 **ppDb,        /* OUT: Returned database handle */
2862   unsigned int flags,    /* Operational flags */
2863   const char *zVfs       /* Name of the VFS to use */
2864 ){
2865   sqlite3 *db;                    /* Store allocated handle here */
2866   int rc;                         /* Return code */
2867   int isThreadsafe;               /* True for threadsafe connections */
2868   char *zOpen = 0;                /* Filename argument to pass to BtreeOpen() */
2869   char *zErrMsg = 0;              /* Error message from sqlite3ParseUri() */
2870 
2871 #ifdef SQLITE_ENABLE_API_ARMOR
2872   if( ppDb==0 ) return SQLITE_MISUSE_BKPT;
2873 #endif
2874   *ppDb = 0;
2875 #ifndef SQLITE_OMIT_AUTOINIT
2876   rc = sqlite3_initialize();
2877   if( rc ) return rc;
2878 #endif
2879 
2880   if( sqlite3GlobalConfig.bCoreMutex==0 ){
2881     isThreadsafe = 0;
2882   }else if( flags & SQLITE_OPEN_NOMUTEX ){
2883     isThreadsafe = 0;
2884   }else if( flags & SQLITE_OPEN_FULLMUTEX ){
2885     isThreadsafe = 1;
2886   }else{
2887     isThreadsafe = sqlite3GlobalConfig.bFullMutex;
2888   }
2889 
2890   if( flags & SQLITE_OPEN_PRIVATECACHE ){
2891     flags &= ~SQLITE_OPEN_SHAREDCACHE;
2892   }else if( sqlite3GlobalConfig.sharedCacheEnabled ){
2893     flags |= SQLITE_OPEN_SHAREDCACHE;
2894   }
2895 
2896   /* Remove harmful bits from the flags parameter
2897   **
2898   ** The SQLITE_OPEN_NOMUTEX and SQLITE_OPEN_FULLMUTEX flags were
2899   ** dealt with in the previous code block.  Besides these, the only
2900   ** valid input flags for sqlite3_open_v2() are SQLITE_OPEN_READONLY,
2901   ** SQLITE_OPEN_READWRITE, SQLITE_OPEN_CREATE, SQLITE_OPEN_SHAREDCACHE,
2902   ** SQLITE_OPEN_PRIVATECACHE, and some reserved bits.  Silently mask
2903   ** off all other flags.
2904   */
2905   flags &=  ~( SQLITE_OPEN_DELETEONCLOSE |
2906                SQLITE_OPEN_EXCLUSIVE |
2907                SQLITE_OPEN_MAIN_DB |
2908                SQLITE_OPEN_TEMP_DB |
2909                SQLITE_OPEN_TRANSIENT_DB |
2910                SQLITE_OPEN_MAIN_JOURNAL |
2911                SQLITE_OPEN_TEMP_JOURNAL |
2912                SQLITE_OPEN_SUBJOURNAL |
2913                SQLITE_OPEN_MASTER_JOURNAL |
2914                SQLITE_OPEN_NOMUTEX |
2915                SQLITE_OPEN_FULLMUTEX |
2916                SQLITE_OPEN_WAL
2917              );
2918 
2919   /* Allocate the sqlite data structure */
2920   db = sqlite3MallocZero( sizeof(sqlite3) );
2921   if( db==0 ) goto opendb_out;
2922   if( isThreadsafe
2923 #ifdef SQLITE_ENABLE_MULTITHREADED_CHECKS
2924    || sqlite3GlobalConfig.bCoreMutex
2925 #endif
2926   ){
2927     db->mutex = sqlite3MutexAlloc(SQLITE_MUTEX_RECURSIVE);
2928     if( db->mutex==0 ){
2929       sqlite3_free(db);
2930       db = 0;
2931       goto opendb_out;
2932     }
2933     if( isThreadsafe==0 ){
2934       sqlite3MutexWarnOnContention(db->mutex);
2935     }
2936   }
2937   sqlite3_mutex_enter(db->mutex);
2938   db->errMask = 0xff;
2939   db->nDb = 2;
2940   db->magic = SQLITE_MAGIC_BUSY;
2941   db->aDb = db->aDbStatic;
2942 
2943   assert( sizeof(db->aLimit)==sizeof(aHardLimit) );
2944   memcpy(db->aLimit, aHardLimit, sizeof(db->aLimit));
2945   db->aLimit[SQLITE_LIMIT_WORKER_THREADS] = SQLITE_DEFAULT_WORKER_THREADS;
2946   db->autoCommit = 1;
2947   db->nextAutovac = -1;
2948   db->szMmap = sqlite3GlobalConfig.szMmap;
2949   db->nextPagesize = 0;
2950   db->nMaxSorterMmap = 0x7FFFFFFF;
2951   db->flags |= SQLITE_ShortColNames | SQLITE_EnableTrigger | SQLITE_CacheSpill
2952 #if !defined(SQLITE_DEFAULT_AUTOMATIC_INDEX) || SQLITE_DEFAULT_AUTOMATIC_INDEX
2953                  | SQLITE_AutoIndex
2954 #endif
2955 #if SQLITE_DEFAULT_CKPTFULLFSYNC
2956                  | SQLITE_CkptFullFSync
2957 #endif
2958 #if SQLITE_DEFAULT_FILE_FORMAT<4
2959                  | SQLITE_LegacyFileFmt
2960 #endif
2961 #ifdef SQLITE_ENABLE_LOAD_EXTENSION
2962                  | SQLITE_LoadExtension
2963 #endif
2964 #if SQLITE_DEFAULT_RECURSIVE_TRIGGERS
2965                  | SQLITE_RecTriggers
2966 #endif
2967 #if defined(SQLITE_DEFAULT_FOREIGN_KEYS) && SQLITE_DEFAULT_FOREIGN_KEYS
2968                  | SQLITE_ForeignKeys
2969 #endif
2970 #if defined(SQLITE_REVERSE_UNORDERED_SELECTS)
2971                  | SQLITE_ReverseOrder
2972 #endif
2973 #if defined(SQLITE_ENABLE_OVERSIZE_CELL_CHECK)
2974                  | SQLITE_CellSizeCk
2975 #endif
2976 #if defined(SQLITE_ENABLE_FTS3_TOKENIZER)
2977                  | SQLITE_Fts3Tokenizer
2978 #endif
2979 #if defined(SQLITE_ENABLE_QPSG)
2980                  | SQLITE_EnableQPSG
2981 #endif
2982       ;
2983   sqlite3HashInit(&db->aCollSeq);
2984 #ifndef SQLITE_OMIT_VIRTUALTABLE
2985   sqlite3HashInit(&db->aModule);
2986 #endif
2987 
2988   /* Add the default collation sequence BINARY. BINARY works for both UTF-8
2989   ** and UTF-16, so add a version for each to avoid any unnecessary
2990   ** conversions. The only error that can occur here is a malloc() failure.
2991   **
2992   ** EVIDENCE-OF: R-52786-44878 SQLite defines three built-in collating
2993   ** functions:
2994   */
2995   createCollation(db, sqlite3StrBINARY, SQLITE_UTF8, 0, binCollFunc, 0);
2996   createCollation(db, sqlite3StrBINARY, SQLITE_UTF16BE, 0, binCollFunc, 0);
2997   createCollation(db, sqlite3StrBINARY, SQLITE_UTF16LE, 0, binCollFunc, 0);
2998   createCollation(db, "NOCASE", SQLITE_UTF8, 0, nocaseCollatingFunc, 0);
2999   createCollation(db, "RTRIM", SQLITE_UTF8, (void*)1, binCollFunc, 0);
3000   if( db->mallocFailed ){
3001     goto opendb_out;
3002   }
3003   /* EVIDENCE-OF: R-08308-17224 The default collating function for all
3004   ** strings is BINARY.
3005   */
3006   db->pDfltColl = sqlite3FindCollSeq(db, SQLITE_UTF8, sqlite3StrBINARY, 0);
3007   assert( db->pDfltColl!=0 );
3008 
3009   /* Parse the filename/URI argument
3010   **
3011   ** Only allow sensible combinations of bits in the flags argument.
3012   ** Throw an error if any non-sense combination is used.  If we
3013   ** do not block illegal combinations here, it could trigger
3014   ** assert() statements in deeper layers.  Sensible combinations
3015   ** are:
3016   **
3017   **  1:  SQLITE_OPEN_READONLY
3018   **  2:  SQLITE_OPEN_READWRITE
3019   **  6:  SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE
3020   */
3021   db->openFlags = flags;
3022   assert( SQLITE_OPEN_READONLY  == 0x01 );
3023   assert( SQLITE_OPEN_READWRITE == 0x02 );
3024   assert( SQLITE_OPEN_CREATE    == 0x04 );
3025   testcase( (1<<(flags&7))==0x02 ); /* READONLY */
3026   testcase( (1<<(flags&7))==0x04 ); /* READWRITE */
3027   testcase( (1<<(flags&7))==0x40 ); /* READWRITE | CREATE */
3028   if( ((1<<(flags&7)) & 0x46)==0 ){
3029     rc = SQLITE_MISUSE_BKPT;  /* IMP: R-65497-44594 */
3030   }else{
3031     rc = sqlite3ParseUri(zVfs, zFilename, &flags, &db->pVfs, &zOpen, &zErrMsg);
3032   }
3033   if( rc!=SQLITE_OK ){
3034     if( rc==SQLITE_NOMEM ) sqlite3OomFault(db);
3035     sqlite3ErrorWithMsg(db, rc, zErrMsg ? "%s" : 0, zErrMsg);
3036     sqlite3_free(zErrMsg);
3037     goto opendb_out;
3038   }
3039 
3040   /* Open the backend database driver */
3041   rc = sqlite3BtreeOpen(db->pVfs, zOpen, db, &db->aDb[0].pBt, 0,
3042                         flags | SQLITE_OPEN_MAIN_DB);
3043   if( rc!=SQLITE_OK ){
3044     if( rc==SQLITE_IOERR_NOMEM ){
3045       rc = SQLITE_NOMEM_BKPT;
3046     }
3047     sqlite3Error(db, rc);
3048     goto opendb_out;
3049   }
3050   sqlite3BtreeEnter(db->aDb[0].pBt);
3051   db->aDb[0].pSchema = sqlite3SchemaGet(db, db->aDb[0].pBt);
3052   if( !db->mallocFailed ) ENC(db) = SCHEMA_ENC(db);
3053   sqlite3BtreeLeave(db->aDb[0].pBt);
3054   db->aDb[1].pSchema = sqlite3SchemaGet(db, 0);
3055 
3056   /* The default safety_level for the main database is FULL; for the temp
3057   ** database it is OFF. This matches the pager layer defaults.
3058   */
3059   db->aDb[0].zDbSName = "main";
3060   db->aDb[0].safety_level = SQLITE_DEFAULT_SYNCHRONOUS+1;
3061   db->aDb[1].zDbSName = "temp";
3062   db->aDb[1].safety_level = PAGER_SYNCHRONOUS_OFF;
3063 
3064   db->magic = SQLITE_MAGIC_OPEN;
3065   if( db->mallocFailed ){
3066     goto opendb_out;
3067   }
3068 
3069   /* Register all built-in functions, but do not attempt to read the
3070   ** database schema yet. This is delayed until the first time the database
3071   ** is accessed.
3072   */
3073   sqlite3Error(db, SQLITE_OK);
3074   sqlite3RegisterPerConnectionBuiltinFunctions(db);
3075   rc = sqlite3_errcode(db);
3076 
3077 #ifdef SQLITE_ENABLE_FTS5
3078   /* Register any built-in FTS5 module before loading the automatic
3079   ** extensions. This allows automatic extensions to register FTS5
3080   ** tokenizers and auxiliary functions.  */
3081   if( !db->mallocFailed && rc==SQLITE_OK ){
3082     rc = sqlite3Fts5Init(db);
3083   }
3084 #endif
3085 
3086   /* Load automatic extensions - extensions that have been registered
3087   ** using the sqlite3_automatic_extension() API.
3088   */
3089   if( rc==SQLITE_OK ){
3090     sqlite3AutoLoadExtensions(db);
3091     rc = sqlite3_errcode(db);
3092     if( rc!=SQLITE_OK ){
3093       goto opendb_out;
3094     }
3095   }
3096 
3097 #ifdef SQLITE_ENABLE_FTS1
3098   if( !db->mallocFailed ){
3099     extern int sqlite3Fts1Init(sqlite3*);
3100     rc = sqlite3Fts1Init(db);
3101   }
3102 #endif
3103 
3104 #ifdef SQLITE_ENABLE_FTS2
3105   if( !db->mallocFailed && rc==SQLITE_OK ){
3106     extern int sqlite3Fts2Init(sqlite3*);
3107     rc = sqlite3Fts2Init(db);
3108   }
3109 #endif
3110 
3111 #ifdef SQLITE_ENABLE_FTS3 /* automatically defined by SQLITE_ENABLE_FTS4 */
3112   if( !db->mallocFailed && rc==SQLITE_OK ){
3113     rc = sqlite3Fts3Init(db);
3114   }
3115 #endif
3116 
3117 #if defined(SQLITE_ENABLE_ICU) || defined(SQLITE_ENABLE_ICU_COLLATIONS)
3118   if( !db->mallocFailed && rc==SQLITE_OK ){
3119     rc = sqlite3IcuInit(db);
3120   }
3121 #endif
3122 
3123 #ifdef SQLITE_ENABLE_RTREE
3124   if( !db->mallocFailed && rc==SQLITE_OK){
3125     rc = sqlite3RtreeInit(db);
3126   }
3127 #endif
3128 
3129 #ifdef SQLITE_ENABLE_DBPAGE_VTAB
3130   if( !db->mallocFailed && rc==SQLITE_OK){
3131     rc = sqlite3DbpageRegister(db);
3132   }
3133 #endif
3134 
3135 #ifdef SQLITE_ENABLE_DBSTAT_VTAB
3136   if( !db->mallocFailed && rc==SQLITE_OK){
3137     rc = sqlite3DbstatRegister(db);
3138   }
3139 #endif
3140 
3141 #ifdef SQLITE_ENABLE_JSON1
3142   if( !db->mallocFailed && rc==SQLITE_OK){
3143     rc = sqlite3Json1Init(db);
3144   }
3145 #endif
3146 
3147 #ifdef SQLITE_ENABLE_STMTVTAB
3148   if( !db->mallocFailed && rc==SQLITE_OK){
3149     rc = sqlite3StmtVtabInit(db);
3150   }
3151 #endif
3152 
3153   /* -DSQLITE_DEFAULT_LOCKING_MODE=1 makes EXCLUSIVE the default locking
3154   ** mode.  -DSQLITE_DEFAULT_LOCKING_MODE=0 make NORMAL the default locking
3155   ** mode.  Doing nothing at all also makes NORMAL the default.
3156   */
3157 #ifdef SQLITE_DEFAULT_LOCKING_MODE
3158   db->dfltLockMode = SQLITE_DEFAULT_LOCKING_MODE;
3159   sqlite3PagerLockingMode(sqlite3BtreePager(db->aDb[0].pBt),
3160                           SQLITE_DEFAULT_LOCKING_MODE);
3161 #endif
3162 
3163   if( rc ) sqlite3Error(db, rc);
3164 
3165   /* Enable the lookaside-malloc subsystem */
3166   setupLookaside(db, 0, sqlite3GlobalConfig.szLookaside,
3167                         sqlite3GlobalConfig.nLookaside);
3168 
3169   sqlite3_wal_autocheckpoint(db, SQLITE_DEFAULT_WAL_AUTOCHECKPOINT);
3170 
3171 opendb_out:
3172   if( db ){
3173     assert( db->mutex!=0 || isThreadsafe==0
3174            || sqlite3GlobalConfig.bFullMutex==0 );
3175     sqlite3_mutex_leave(db->mutex);
3176   }
3177   rc = sqlite3_errcode(db);
3178   assert( db!=0 || rc==SQLITE_NOMEM );
3179   if( rc==SQLITE_NOMEM ){
3180     sqlite3_close(db);
3181     db = 0;
3182   }else if( rc!=SQLITE_OK ){
3183     db->magic = SQLITE_MAGIC_SICK;
3184   }
3185   *ppDb = db;
3186 #ifdef SQLITE_ENABLE_SQLLOG
3187   if( sqlite3GlobalConfig.xSqllog ){
3188     /* Opening a db handle. Fourth parameter is passed 0. */
3189     void *pArg = sqlite3GlobalConfig.pSqllogArg;
3190     sqlite3GlobalConfig.xSqllog(pArg, db, zFilename, 0);
3191   }
3192 #endif
3193 #if defined(SQLITE_HAS_CODEC)
3194   if( rc==SQLITE_OK ){
3195     const char *zKey;
3196     if( (zKey = sqlite3_uri_parameter(zOpen, "hexkey"))!=0 && zKey[0] ){
3197       u8 iByte;
3198       int i;
3199       char zDecoded[40];
3200       for(i=0, iByte=0; i<sizeof(zDecoded)*2 && sqlite3Isxdigit(zKey[i]); i++){
3201         iByte = (iByte<<4) + sqlite3HexToInt(zKey[i]);
3202         if( (i&1)!=0 ) zDecoded[i/2] = iByte;
3203       }
3204       sqlite3_key_v2(db, 0, zDecoded, i/2);
3205     }else if( (zKey = sqlite3_uri_parameter(zOpen, "key"))!=0 ){
3206       sqlite3_key_v2(db, 0, zKey, sqlite3Strlen30(zKey));
3207     }
3208   }
3209 #endif
3210   sqlite3_free(zOpen);
3211   return rc & 0xff;
3212 }
3213 
3214 /*
3215 ** Open a new database handle.
3216 */
3217 int sqlite3_open(
3218   const char *zFilename,
3219   sqlite3 **ppDb
3220 ){
3221   return openDatabase(zFilename, ppDb,
3222                       SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
3223 }
3224 int sqlite3_open_v2(
3225   const char *filename,   /* Database filename (UTF-8) */
3226   sqlite3 **ppDb,         /* OUT: SQLite db handle */
3227   int flags,              /* Flags */
3228   const char *zVfs        /* Name of VFS module to use */
3229 ){
3230   return openDatabase(filename, ppDb, (unsigned int)flags, zVfs);
3231 }
3232 
3233 #ifndef SQLITE_OMIT_UTF16
3234 /*
3235 ** Open a new database handle.
3236 */
3237 int sqlite3_open16(
3238   const void *zFilename,
3239   sqlite3 **ppDb
3240 ){
3241   char const *zFilename8;   /* zFilename encoded in UTF-8 instead of UTF-16 */
3242   sqlite3_value *pVal;
3243   int rc;
3244 
3245 #ifdef SQLITE_ENABLE_API_ARMOR
3246   if( ppDb==0 ) return SQLITE_MISUSE_BKPT;
3247 #endif
3248   *ppDb = 0;
3249 #ifndef SQLITE_OMIT_AUTOINIT
3250   rc = sqlite3_initialize();
3251   if( rc ) return rc;
3252 #endif
3253   if( zFilename==0 ) zFilename = "\000\000";
3254   pVal = sqlite3ValueNew(0);
3255   sqlite3ValueSetStr(pVal, -1, zFilename, SQLITE_UTF16NATIVE, SQLITE_STATIC);
3256   zFilename8 = sqlite3ValueText(pVal, SQLITE_UTF8);
3257   if( zFilename8 ){
3258     rc = openDatabase(zFilename8, ppDb,
3259                       SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
3260     assert( *ppDb || rc==SQLITE_NOMEM );
3261     if( rc==SQLITE_OK && !DbHasProperty(*ppDb, 0, DB_SchemaLoaded) ){
3262       SCHEMA_ENC(*ppDb) = ENC(*ppDb) = SQLITE_UTF16NATIVE;
3263     }
3264   }else{
3265     rc = SQLITE_NOMEM_BKPT;
3266   }
3267   sqlite3ValueFree(pVal);
3268 
3269   return rc & 0xff;
3270 }
3271 #endif /* SQLITE_OMIT_UTF16 */
3272 
3273 /*
3274 ** Register a new collation sequence with the database handle db.
3275 */
3276 int sqlite3_create_collation(
3277   sqlite3* db,
3278   const char *zName,
3279   int enc,
3280   void* pCtx,
3281   int(*xCompare)(void*,int,const void*,int,const void*)
3282 ){
3283   return sqlite3_create_collation_v2(db, zName, enc, pCtx, xCompare, 0);
3284 }
3285 
3286 /*
3287 ** Register a new collation sequence with the database handle db.
3288 */
3289 int sqlite3_create_collation_v2(
3290   sqlite3* db,
3291   const char *zName,
3292   int enc,
3293   void* pCtx,
3294   int(*xCompare)(void*,int,const void*,int,const void*),
3295   void(*xDel)(void*)
3296 ){
3297   int rc;
3298 
3299 #ifdef SQLITE_ENABLE_API_ARMOR
3300   if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
3301 #endif
3302   sqlite3_mutex_enter(db->mutex);
3303   assert( !db->mallocFailed );
3304   rc = createCollation(db, zName, (u8)enc, pCtx, xCompare, xDel);
3305   rc = sqlite3ApiExit(db, rc);
3306   sqlite3_mutex_leave(db->mutex);
3307   return rc;
3308 }
3309 
3310 #ifndef SQLITE_OMIT_UTF16
3311 /*
3312 ** Register a new collation sequence with the database handle db.
3313 */
3314 int sqlite3_create_collation16(
3315   sqlite3* db,
3316   const void *zName,
3317   int enc,
3318   void* pCtx,
3319   int(*xCompare)(void*,int,const void*,int,const void*)
3320 ){
3321   int rc = SQLITE_OK;
3322   char *zName8;
3323 
3324 #ifdef SQLITE_ENABLE_API_ARMOR
3325   if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
3326 #endif
3327   sqlite3_mutex_enter(db->mutex);
3328   assert( !db->mallocFailed );
3329   zName8 = sqlite3Utf16to8(db, zName, -1, SQLITE_UTF16NATIVE);
3330   if( zName8 ){
3331     rc = createCollation(db, zName8, (u8)enc, pCtx, xCompare, 0);
3332     sqlite3DbFree(db, zName8);
3333   }
3334   rc = sqlite3ApiExit(db, rc);
3335   sqlite3_mutex_leave(db->mutex);
3336   return rc;
3337 }
3338 #endif /* SQLITE_OMIT_UTF16 */
3339 
3340 /*
3341 ** Register a collation sequence factory callback with the database handle
3342 ** db. Replace any previously installed collation sequence factory.
3343 */
3344 int sqlite3_collation_needed(
3345   sqlite3 *db,
3346   void *pCollNeededArg,
3347   void(*xCollNeeded)(void*,sqlite3*,int eTextRep,const char*)
3348 ){
3349 #ifdef SQLITE_ENABLE_API_ARMOR
3350   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3351 #endif
3352   sqlite3_mutex_enter(db->mutex);
3353   db->xCollNeeded = xCollNeeded;
3354   db->xCollNeeded16 = 0;
3355   db->pCollNeededArg = pCollNeededArg;
3356   sqlite3_mutex_leave(db->mutex);
3357   return SQLITE_OK;
3358 }
3359 
3360 #ifndef SQLITE_OMIT_UTF16
3361 /*
3362 ** Register a collation sequence factory callback with the database handle
3363 ** db. Replace any previously installed collation sequence factory.
3364 */
3365 int sqlite3_collation_needed16(
3366   sqlite3 *db,
3367   void *pCollNeededArg,
3368   void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*)
3369 ){
3370 #ifdef SQLITE_ENABLE_API_ARMOR
3371   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3372 #endif
3373   sqlite3_mutex_enter(db->mutex);
3374   db->xCollNeeded = 0;
3375   db->xCollNeeded16 = xCollNeeded16;
3376   db->pCollNeededArg = pCollNeededArg;
3377   sqlite3_mutex_leave(db->mutex);
3378   return SQLITE_OK;
3379 }
3380 #endif /* SQLITE_OMIT_UTF16 */
3381 
3382 #ifndef SQLITE_OMIT_DEPRECATED
3383 /*
3384 ** This function is now an anachronism. It used to be used to recover from a
3385 ** malloc() failure, but SQLite now does this automatically.
3386 */
3387 int sqlite3_global_recover(void){
3388   return SQLITE_OK;
3389 }
3390 #endif
3391 
3392 /*
3393 ** Test to see whether or not the database connection is in autocommit
3394 ** mode.  Return TRUE if it is and FALSE if not.  Autocommit mode is on
3395 ** by default.  Autocommit is disabled by a BEGIN statement and reenabled
3396 ** by the next COMMIT or ROLLBACK.
3397 */
3398 int sqlite3_get_autocommit(sqlite3 *db){
3399 #ifdef SQLITE_ENABLE_API_ARMOR
3400   if( !sqlite3SafetyCheckOk(db) ){
3401     (void)SQLITE_MISUSE_BKPT;
3402     return 0;
3403   }
3404 #endif
3405   return db->autoCommit;
3406 }
3407 
3408 /*
3409 ** The following routines are substitutes for constants SQLITE_CORRUPT,
3410 ** SQLITE_MISUSE, SQLITE_CANTOPEN, SQLITE_NOMEM and possibly other error
3411 ** constants.  They serve two purposes:
3412 **
3413 **   1.  Serve as a convenient place to set a breakpoint in a debugger
3414 **       to detect when version error conditions occurs.
3415 **
3416 **   2.  Invoke sqlite3_log() to provide the source code location where
3417 **       a low-level error is first detected.
3418 */
3419 int sqlite3ReportError(int iErr, int lineno, const char *zType){
3420   sqlite3_log(iErr, "%s at line %d of [%.10s]",
3421               zType, lineno, 20+sqlite3_sourceid());
3422   return iErr;
3423 }
3424 int sqlite3CorruptError(int lineno){
3425   testcase( sqlite3GlobalConfig.xLog!=0 );
3426   return sqlite3ReportError(SQLITE_CORRUPT, lineno, "database corruption");
3427 }
3428 int sqlite3MisuseError(int lineno){
3429   testcase( sqlite3GlobalConfig.xLog!=0 );
3430   return sqlite3ReportError(SQLITE_MISUSE, lineno, "misuse");
3431 }
3432 int sqlite3CantopenError(int lineno){
3433   testcase( sqlite3GlobalConfig.xLog!=0 );
3434   return sqlite3ReportError(SQLITE_CANTOPEN, lineno, "cannot open file");
3435 }
3436 #ifdef SQLITE_DEBUG
3437 int sqlite3CorruptPgnoError(int lineno, Pgno pgno){
3438   char zMsg[100];
3439   sqlite3_snprintf(sizeof(zMsg), zMsg, "database corruption page %d", pgno);
3440   testcase( sqlite3GlobalConfig.xLog!=0 );
3441   return sqlite3ReportError(SQLITE_CORRUPT, lineno, zMsg);
3442 }
3443 int sqlite3NomemError(int lineno){
3444   testcase( sqlite3GlobalConfig.xLog!=0 );
3445   return sqlite3ReportError(SQLITE_NOMEM, lineno, "OOM");
3446 }
3447 int sqlite3IoerrnomemError(int lineno){
3448   testcase( sqlite3GlobalConfig.xLog!=0 );
3449   return sqlite3ReportError(SQLITE_IOERR_NOMEM, lineno, "I/O OOM error");
3450 }
3451 #endif
3452 
3453 #ifndef SQLITE_OMIT_DEPRECATED
3454 /*
3455 ** This is a convenience routine that makes sure that all thread-specific
3456 ** data for this thread has been deallocated.
3457 **
3458 ** SQLite no longer uses thread-specific data so this routine is now a
3459 ** no-op.  It is retained for historical compatibility.
3460 */
3461 void sqlite3_thread_cleanup(void){
3462 }
3463 #endif
3464 
3465 /*
3466 ** Return meta information about a specific column of a database table.
3467 ** See comment in sqlite3.h (sqlite.h.in) for details.
3468 */
3469 int sqlite3_table_column_metadata(
3470   sqlite3 *db,                /* Connection handle */
3471   const char *zDbName,        /* Database name or NULL */
3472   const char *zTableName,     /* Table name */
3473   const char *zColumnName,    /* Column name */
3474   char const **pzDataType,    /* OUTPUT: Declared data type */
3475   char const **pzCollSeq,     /* OUTPUT: Collation sequence name */
3476   int *pNotNull,              /* OUTPUT: True if NOT NULL constraint exists */
3477   int *pPrimaryKey,           /* OUTPUT: True if column part of PK */
3478   int *pAutoinc               /* OUTPUT: True if column is auto-increment */
3479 ){
3480   int rc;
3481   char *zErrMsg = 0;
3482   Table *pTab = 0;
3483   Column *pCol = 0;
3484   int iCol = 0;
3485   char const *zDataType = 0;
3486   char const *zCollSeq = 0;
3487   int notnull = 0;
3488   int primarykey = 0;
3489   int autoinc = 0;
3490 
3491 
3492 #ifdef SQLITE_ENABLE_API_ARMOR
3493   if( !sqlite3SafetyCheckOk(db) || zTableName==0 ){
3494     return SQLITE_MISUSE_BKPT;
3495   }
3496 #endif
3497 
3498   /* Ensure the database schema has been loaded */
3499   sqlite3_mutex_enter(db->mutex);
3500   sqlite3BtreeEnterAll(db);
3501   rc = sqlite3Init(db, &zErrMsg);
3502   if( SQLITE_OK!=rc ){
3503     goto error_out;
3504   }
3505 
3506   /* Locate the table in question */
3507   pTab = sqlite3FindTable(db, zTableName, zDbName);
3508   if( !pTab || pTab->pSelect ){
3509     pTab = 0;
3510     goto error_out;
3511   }
3512 
3513   /* Find the column for which info is requested */
3514   if( zColumnName==0 ){
3515     /* Query for existance of table only */
3516   }else{
3517     for(iCol=0; iCol<pTab->nCol; iCol++){
3518       pCol = &pTab->aCol[iCol];
3519       if( 0==sqlite3StrICmp(pCol->zName, zColumnName) ){
3520         break;
3521       }
3522     }
3523     if( iCol==pTab->nCol ){
3524       if( HasRowid(pTab) && sqlite3IsRowid(zColumnName) ){
3525         iCol = pTab->iPKey;
3526         pCol = iCol>=0 ? &pTab->aCol[iCol] : 0;
3527       }else{
3528         pTab = 0;
3529         goto error_out;
3530       }
3531     }
3532   }
3533 
3534   /* The following block stores the meta information that will be returned
3535   ** to the caller in local variables zDataType, zCollSeq, notnull, primarykey
3536   ** and autoinc. At this point there are two possibilities:
3537   **
3538   **     1. The specified column name was rowid", "oid" or "_rowid_"
3539   **        and there is no explicitly declared IPK column.
3540   **
3541   **     2. The table is not a view and the column name identified an
3542   **        explicitly declared column. Copy meta information from *pCol.
3543   */
3544   if( pCol ){
3545     zDataType = sqlite3ColumnType(pCol,0);
3546     zCollSeq = pCol->zColl;
3547     notnull = pCol->notNull!=0;
3548     primarykey  = (pCol->colFlags & COLFLAG_PRIMKEY)!=0;
3549     autoinc = pTab->iPKey==iCol && (pTab->tabFlags & TF_Autoincrement)!=0;
3550   }else{
3551     zDataType = "INTEGER";
3552     primarykey = 1;
3553   }
3554   if( !zCollSeq ){
3555     zCollSeq = sqlite3StrBINARY;
3556   }
3557 
3558 error_out:
3559   sqlite3BtreeLeaveAll(db);
3560 
3561   /* Whether the function call succeeded or failed, set the output parameters
3562   ** to whatever their local counterparts contain. If an error did occur,
3563   ** this has the effect of zeroing all output parameters.
3564   */
3565   if( pzDataType ) *pzDataType = zDataType;
3566   if( pzCollSeq ) *pzCollSeq = zCollSeq;
3567   if( pNotNull ) *pNotNull = notnull;
3568   if( pPrimaryKey ) *pPrimaryKey = primarykey;
3569   if( pAutoinc ) *pAutoinc = autoinc;
3570 
3571   if( SQLITE_OK==rc && !pTab ){
3572     sqlite3DbFree(db, zErrMsg);
3573     zErrMsg = sqlite3MPrintf(db, "no such table column: %s.%s", zTableName,
3574         zColumnName);
3575     rc = SQLITE_ERROR;
3576   }
3577   sqlite3ErrorWithMsg(db, rc, (zErrMsg?"%s":0), zErrMsg);
3578   sqlite3DbFree(db, zErrMsg);
3579   rc = sqlite3ApiExit(db, rc);
3580   sqlite3_mutex_leave(db->mutex);
3581   return rc;
3582 }
3583 
3584 /*
3585 ** Sleep for a little while.  Return the amount of time slept.
3586 */
3587 int sqlite3_sleep(int ms){
3588   sqlite3_vfs *pVfs;
3589   int rc;
3590   pVfs = sqlite3_vfs_find(0);
3591   if( pVfs==0 ) return 0;
3592 
3593   /* This function works in milliseconds, but the underlying OsSleep()
3594   ** API uses microseconds. Hence the 1000's.
3595   */
3596   rc = (sqlite3OsSleep(pVfs, 1000*ms)/1000);
3597   return rc;
3598 }
3599 
3600 /*
3601 ** Enable or disable the extended result codes.
3602 */
3603 int sqlite3_extended_result_codes(sqlite3 *db, int onoff){
3604 #ifdef SQLITE_ENABLE_API_ARMOR
3605   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3606 #endif
3607   sqlite3_mutex_enter(db->mutex);
3608   db->errMask = onoff ? 0xffffffff : 0xff;
3609   sqlite3_mutex_leave(db->mutex);
3610   return SQLITE_OK;
3611 }
3612 
3613 /*
3614 ** Invoke the xFileControl method on a particular database.
3615 */
3616 int sqlite3_file_control(sqlite3 *db, const char *zDbName, int op, void *pArg){
3617   int rc = SQLITE_ERROR;
3618   Btree *pBtree;
3619 
3620 #ifdef SQLITE_ENABLE_API_ARMOR
3621   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3622 #endif
3623   sqlite3_mutex_enter(db->mutex);
3624   pBtree = sqlite3DbNameToBtree(db, zDbName);
3625   if( pBtree ){
3626     Pager *pPager;
3627     sqlite3_file *fd;
3628     sqlite3BtreeEnter(pBtree);
3629     pPager = sqlite3BtreePager(pBtree);
3630     assert( pPager!=0 );
3631     fd = sqlite3PagerFile(pPager);
3632     assert( fd!=0 );
3633     if( op==SQLITE_FCNTL_FILE_POINTER ){
3634       *(sqlite3_file**)pArg = fd;
3635       rc = SQLITE_OK;
3636     }else if( op==SQLITE_FCNTL_VFS_POINTER ){
3637       *(sqlite3_vfs**)pArg = sqlite3PagerVfs(pPager);
3638       rc = SQLITE_OK;
3639     }else if( op==SQLITE_FCNTL_JOURNAL_POINTER ){
3640       *(sqlite3_file**)pArg = sqlite3PagerJrnlFile(pPager);
3641       rc = SQLITE_OK;
3642     }else{
3643       rc = sqlite3OsFileControl(fd, op, pArg);
3644     }
3645     sqlite3BtreeLeave(pBtree);
3646   }
3647   sqlite3_mutex_leave(db->mutex);
3648   return rc;
3649 }
3650 
3651 /*
3652 ** Interface to the testing logic.
3653 */
3654 int sqlite3_test_control(int op, ...){
3655   int rc = 0;
3656 #ifdef SQLITE_UNTESTABLE
3657   UNUSED_PARAMETER(op);
3658 #else
3659   va_list ap;
3660   va_start(ap, op);
3661   switch( op ){
3662 
3663     /*
3664     ** Save the current state of the PRNG.
3665     */
3666     case SQLITE_TESTCTRL_PRNG_SAVE: {
3667       sqlite3PrngSaveState();
3668       break;
3669     }
3670 
3671     /*
3672     ** Restore the state of the PRNG to the last state saved using
3673     ** PRNG_SAVE.  If PRNG_SAVE has never before been called, then
3674     ** this verb acts like PRNG_RESET.
3675     */
3676     case SQLITE_TESTCTRL_PRNG_RESTORE: {
3677       sqlite3PrngRestoreState();
3678       break;
3679     }
3680 
3681     /*
3682     ** Reset the PRNG back to its uninitialized state.  The next call
3683     ** to sqlite3_randomness() will reseed the PRNG using a single call
3684     ** to the xRandomness method of the default VFS.
3685     */
3686     case SQLITE_TESTCTRL_PRNG_RESET: {
3687       sqlite3_randomness(0,0);
3688       break;
3689     }
3690 
3691     /*
3692     **  sqlite3_test_control(BITVEC_TEST, size, program)
3693     **
3694     ** Run a test against a Bitvec object of size.  The program argument
3695     ** is an array of integers that defines the test.  Return -1 on a
3696     ** memory allocation error, 0 on success, or non-zero for an error.
3697     ** See the sqlite3BitvecBuiltinTest() for additional information.
3698     */
3699     case SQLITE_TESTCTRL_BITVEC_TEST: {
3700       int sz = va_arg(ap, int);
3701       int *aProg = va_arg(ap, int*);
3702       rc = sqlite3BitvecBuiltinTest(sz, aProg);
3703       break;
3704     }
3705 
3706     /*
3707     **  sqlite3_test_control(FAULT_INSTALL, xCallback)
3708     **
3709     ** Arrange to invoke xCallback() whenever sqlite3FaultSim() is called,
3710     ** if xCallback is not NULL.
3711     **
3712     ** As a test of the fault simulator mechanism itself, sqlite3FaultSim(0)
3713     ** is called immediately after installing the new callback and the return
3714     ** value from sqlite3FaultSim(0) becomes the return from
3715     ** sqlite3_test_control().
3716     */
3717     case SQLITE_TESTCTRL_FAULT_INSTALL: {
3718       /* MSVC is picky about pulling func ptrs from va lists.
3719       ** http://support.microsoft.com/kb/47961
3720       ** sqlite3GlobalConfig.xTestCallback = va_arg(ap, int(*)(int));
3721       */
3722       typedef int(*TESTCALLBACKFUNC_t)(int);
3723       sqlite3GlobalConfig.xTestCallback = va_arg(ap, TESTCALLBACKFUNC_t);
3724       rc = sqlite3FaultSim(0);
3725       break;
3726     }
3727 
3728     /*
3729     **  sqlite3_test_control(BENIGN_MALLOC_HOOKS, xBegin, xEnd)
3730     **
3731     ** Register hooks to call to indicate which malloc() failures
3732     ** are benign.
3733     */
3734     case SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS: {
3735       typedef void (*void_function)(void);
3736       void_function xBenignBegin;
3737       void_function xBenignEnd;
3738       xBenignBegin = va_arg(ap, void_function);
3739       xBenignEnd = va_arg(ap, void_function);
3740       sqlite3BenignMallocHooks(xBenignBegin, xBenignEnd);
3741       break;
3742     }
3743 
3744     /*
3745     **  sqlite3_test_control(SQLITE_TESTCTRL_PENDING_BYTE, unsigned int X)
3746     **
3747     ** Set the PENDING byte to the value in the argument, if X>0.
3748     ** Make no changes if X==0.  Return the value of the pending byte
3749     ** as it existing before this routine was called.
3750     **
3751     ** IMPORTANT:  Changing the PENDING byte from 0x40000000 results in
3752     ** an incompatible database file format.  Changing the PENDING byte
3753     ** while any database connection is open results in undefined and
3754     ** deleterious behavior.
3755     */
3756     case SQLITE_TESTCTRL_PENDING_BYTE: {
3757       rc = PENDING_BYTE;
3758 #ifndef SQLITE_OMIT_WSD
3759       {
3760         unsigned int newVal = va_arg(ap, unsigned int);
3761         if( newVal ) sqlite3PendingByte = newVal;
3762       }
3763 #endif
3764       break;
3765     }
3766 
3767     /*
3768     **  sqlite3_test_control(SQLITE_TESTCTRL_ASSERT, int X)
3769     **
3770     ** This action provides a run-time test to see whether or not
3771     ** assert() was enabled at compile-time.  If X is true and assert()
3772     ** is enabled, then the return value is true.  If X is true and
3773     ** assert() is disabled, then the return value is zero.  If X is
3774     ** false and assert() is enabled, then the assertion fires and the
3775     ** process aborts.  If X is false and assert() is disabled, then the
3776     ** return value is zero.
3777     */
3778     case SQLITE_TESTCTRL_ASSERT: {
3779       volatile int x = 0;
3780       assert( /*side-effects-ok*/ (x = va_arg(ap,int))!=0 );
3781       rc = x;
3782       break;
3783     }
3784 
3785 
3786     /*
3787     **  sqlite3_test_control(SQLITE_TESTCTRL_ALWAYS, int X)
3788     **
3789     ** This action provides a run-time test to see how the ALWAYS and
3790     ** NEVER macros were defined at compile-time.
3791     **
3792     ** The return value is ALWAYS(X) if X is true, or 0 if X is false.
3793     **
3794     ** The recommended test is X==2.  If the return value is 2, that means
3795     ** ALWAYS() and NEVER() are both no-op pass-through macros, which is the
3796     ** default setting.  If the return value is 1, then ALWAYS() is either
3797     ** hard-coded to true or else it asserts if its argument is false.
3798     ** The first behavior (hard-coded to true) is the case if
3799     ** SQLITE_TESTCTRL_ASSERT shows that assert() is disabled and the second
3800     ** behavior (assert if the argument to ALWAYS() is false) is the case if
3801     ** SQLITE_TESTCTRL_ASSERT shows that assert() is enabled.
3802     **
3803     ** The run-time test procedure might look something like this:
3804     **
3805     **    if( sqlite3_test_control(SQLITE_TESTCTRL_ALWAYS, 2)==2 ){
3806     **      // ALWAYS() and NEVER() are no-op pass-through macros
3807     **    }else if( sqlite3_test_control(SQLITE_TESTCTRL_ASSERT, 1) ){
3808     **      // ALWAYS(x) asserts that x is true. NEVER(x) asserts x is false.
3809     **    }else{
3810     **      // ALWAYS(x) is a constant 1.  NEVER(x) is a constant 0.
3811     **    }
3812     */
3813     case SQLITE_TESTCTRL_ALWAYS: {
3814       int x = va_arg(ap,int);
3815       rc = x ? ALWAYS(x) : 0;
3816       break;
3817     }
3818 
3819     /*
3820     **   sqlite3_test_control(SQLITE_TESTCTRL_BYTEORDER);
3821     **
3822     ** The integer returned reveals the byte-order of the computer on which
3823     ** SQLite is running:
3824     **
3825     **       1     big-endian,    determined at run-time
3826     **      10     little-endian, determined at run-time
3827     **  432101     big-endian,    determined at compile-time
3828     **  123410     little-endian, determined at compile-time
3829     */
3830     case SQLITE_TESTCTRL_BYTEORDER: {
3831       rc = SQLITE_BYTEORDER*100 + SQLITE_LITTLEENDIAN*10 + SQLITE_BIGENDIAN;
3832       break;
3833     }
3834 
3835     /*   sqlite3_test_control(SQLITE_TESTCTRL_RESERVE, sqlite3 *db, int N)
3836     **
3837     ** Set the nReserve size to N for the main database on the database
3838     ** connection db.
3839     */
3840     case SQLITE_TESTCTRL_RESERVE: {
3841       sqlite3 *db = va_arg(ap, sqlite3*);
3842       int x = va_arg(ap,int);
3843       sqlite3_mutex_enter(db->mutex);
3844       sqlite3BtreeSetPageSize(db->aDb[0].pBt, 0, x, 0);
3845       sqlite3_mutex_leave(db->mutex);
3846       break;
3847     }
3848 
3849     /*  sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS, sqlite3 *db, int N)
3850     **
3851     ** Enable or disable various optimizations for testing purposes.  The
3852     ** argument N is a bitmask of optimizations to be disabled.  For normal
3853     ** operation N should be 0.  The idea is that a test program (like the
3854     ** SQL Logic Test or SLT test module) can run the same SQL multiple times
3855     ** with various optimizations disabled to verify that the same answer
3856     ** is obtained in every case.
3857     */
3858     case SQLITE_TESTCTRL_OPTIMIZATIONS: {
3859       sqlite3 *db = va_arg(ap, sqlite3*);
3860       db->dbOptFlags = (u16)(va_arg(ap, int) & 0xffff);
3861       break;
3862     }
3863 
3864 #ifdef SQLITE_N_KEYWORD
3865     /* sqlite3_test_control(SQLITE_TESTCTRL_ISKEYWORD, const char *zWord)
3866     **
3867     ** If zWord is a keyword recognized by the parser, then return the
3868     ** number of keywords.  Or if zWord is not a keyword, return 0.
3869     **
3870     ** This test feature is only available in the amalgamation since
3871     ** the SQLITE_N_KEYWORD macro is not defined in this file if SQLite
3872     ** is built using separate source files.
3873     */
3874     case SQLITE_TESTCTRL_ISKEYWORD: {
3875       const char *zWord = va_arg(ap, const char*);
3876       int n = sqlite3Strlen30(zWord);
3877       rc = (sqlite3KeywordCode((u8*)zWord, n)!=TK_ID) ? SQLITE_N_KEYWORD : 0;
3878       break;
3879     }
3880 #endif
3881 
3882     /*   sqlite3_test_control(SQLITE_TESTCTRL_LOCALTIME_FAULT, int onoff);
3883     **
3884     ** If parameter onoff is non-zero, configure the wrappers so that all
3885     ** subsequent calls to localtime() and variants fail. If onoff is zero,
3886     ** undo this setting.
3887     */
3888     case SQLITE_TESTCTRL_LOCALTIME_FAULT: {
3889       sqlite3GlobalConfig.bLocaltimeFault = va_arg(ap, int);
3890       break;
3891     }
3892 
3893     /*   sqlite3_test_control(SQLITE_TESTCTRL_NEVER_CORRUPT, int);
3894     **
3895     ** Set or clear a flag that indicates that the database file is always well-
3896     ** formed and never corrupt.  This flag is clear by default, indicating that
3897     ** database files might have arbitrary corruption.  Setting the flag during
3898     ** testing causes certain assert() statements in the code to be activated
3899     ** that demonstrat invariants on well-formed database files.
3900     */
3901     case SQLITE_TESTCTRL_NEVER_CORRUPT: {
3902       sqlite3GlobalConfig.neverCorrupt = va_arg(ap, int);
3903       break;
3904     }
3905 
3906     /* Set the threshold at which OP_Once counters reset back to zero.
3907     ** By default this is 0x7ffffffe (over 2 billion), but that value is
3908     ** too big to test in a reasonable amount of time, so this control is
3909     ** provided to set a small and easily reachable reset value.
3910     */
3911     case SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD: {
3912       sqlite3GlobalConfig.iOnceResetThreshold = va_arg(ap, int);
3913       break;
3914     }
3915 
3916     /*   sqlite3_test_control(SQLITE_TESTCTRL_VDBE_COVERAGE, xCallback, ptr);
3917     **
3918     ** Set the VDBE coverage callback function to xCallback with context
3919     ** pointer ptr.
3920     */
3921     case SQLITE_TESTCTRL_VDBE_COVERAGE: {
3922 #ifdef SQLITE_VDBE_COVERAGE
3923       typedef void (*branch_callback)(void*,int,u8,u8);
3924       sqlite3GlobalConfig.xVdbeBranch = va_arg(ap,branch_callback);
3925       sqlite3GlobalConfig.pVdbeBranchArg = va_arg(ap,void*);
3926 #endif
3927       break;
3928     }
3929 
3930     /*   sqlite3_test_control(SQLITE_TESTCTRL_SORTER_MMAP, db, nMax); */
3931     case SQLITE_TESTCTRL_SORTER_MMAP: {
3932       sqlite3 *db = va_arg(ap, sqlite3*);
3933       db->nMaxSorterMmap = va_arg(ap, int);
3934       break;
3935     }
3936 
3937     /*   sqlite3_test_control(SQLITE_TESTCTRL_ISINIT);
3938     **
3939     ** Return SQLITE_OK if SQLite has been initialized and SQLITE_ERROR if
3940     ** not.
3941     */
3942     case SQLITE_TESTCTRL_ISINIT: {
3943       if( sqlite3GlobalConfig.isInit==0 ) rc = SQLITE_ERROR;
3944       break;
3945     }
3946 
3947     /*  sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, db, dbName, onOff, tnum);
3948     **
3949     ** This test control is used to create imposter tables.  "db" is a pointer
3950     ** to the database connection.  dbName is the database name (ex: "main" or
3951     ** "temp") which will receive the imposter.  "onOff" turns imposter mode on
3952     ** or off.  "tnum" is the root page of the b-tree to which the imposter
3953     ** table should connect.
3954     **
3955     ** Enable imposter mode only when the schema has already been parsed.  Then
3956     ** run a single CREATE TABLE statement to construct the imposter table in
3957     ** the parsed schema.  Then turn imposter mode back off again.
3958     **
3959     ** If onOff==0 and tnum>0 then reset the schema for all databases, causing
3960     ** the schema to be reparsed the next time it is needed.  This has the
3961     ** effect of erasing all imposter tables.
3962     */
3963     case SQLITE_TESTCTRL_IMPOSTER: {
3964       sqlite3 *db = va_arg(ap, sqlite3*);
3965       sqlite3_mutex_enter(db->mutex);
3966       db->init.iDb = sqlite3FindDbName(db, va_arg(ap,const char*));
3967       db->init.busy = db->init.imposterTable = va_arg(ap,int);
3968       db->init.newTnum = va_arg(ap,int);
3969       if( db->init.busy==0 && db->init.newTnum>0 ){
3970         sqlite3ResetAllSchemasOfConnection(db);
3971       }
3972       sqlite3_mutex_leave(db->mutex);
3973       break;
3974     }
3975 
3976 #if defined(YYCOVERAGE)
3977     /*  sqlite3_test_control(SQLITE_TESTCTRL_PARSER_COVERAGE, FILE *out)
3978     **
3979     ** This test control (only available when SQLite is compiled with
3980     ** -DYYCOVERAGE) writes a report onto "out" that shows all
3981     ** state/lookahead combinations in the parser state machine
3982     ** which are never exercised.  If any state is missed, make the
3983     ** return code SQLITE_ERROR.
3984     */
3985     case SQLITE_TESTCTRL_PARSER_COVERAGE: {
3986       FILE *out = va_arg(ap, FILE*);
3987       if( sqlite3ParserCoverage(out) ) rc = SQLITE_ERROR;
3988       break;
3989     }
3990 #endif /* defined(YYCOVERAGE) */
3991   }
3992   va_end(ap);
3993 #endif /* SQLITE_UNTESTABLE */
3994   return rc;
3995 }
3996 
3997 /*
3998 ** This is a utility routine, useful to VFS implementations, that checks
3999 ** to see if a database file was a URI that contained a specific query
4000 ** parameter, and if so obtains the value of the query parameter.
4001 **
4002 ** The zFilename argument is the filename pointer passed into the xOpen()
4003 ** method of a VFS implementation.  The zParam argument is the name of the
4004 ** query parameter we seek.  This routine returns the value of the zParam
4005 ** parameter if it exists.  If the parameter does not exist, this routine
4006 ** returns a NULL pointer.
4007 */
4008 const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam){
4009   if( zFilename==0 || zParam==0 ) return 0;
4010   zFilename += sqlite3Strlen30(zFilename) + 1;
4011   while( zFilename[0] ){
4012     int x = strcmp(zFilename, zParam);
4013     zFilename += sqlite3Strlen30(zFilename) + 1;
4014     if( x==0 ) return zFilename;
4015     zFilename += sqlite3Strlen30(zFilename) + 1;
4016   }
4017   return 0;
4018 }
4019 
4020 /*
4021 ** Return a boolean value for a query parameter.
4022 */
4023 int sqlite3_uri_boolean(const char *zFilename, const char *zParam, int bDflt){
4024   const char *z = sqlite3_uri_parameter(zFilename, zParam);
4025   bDflt = bDflt!=0;
4026   return z ? sqlite3GetBoolean(z, bDflt) : bDflt;
4027 }
4028 
4029 /*
4030 ** Return a 64-bit integer value for a query parameter.
4031 */
4032 sqlite3_int64 sqlite3_uri_int64(
4033   const char *zFilename,    /* Filename as passed to xOpen */
4034   const char *zParam,       /* URI parameter sought */
4035   sqlite3_int64 bDflt       /* return if parameter is missing */
4036 ){
4037   const char *z = sqlite3_uri_parameter(zFilename, zParam);
4038   sqlite3_int64 v;
4039   if( z && sqlite3DecOrHexToI64(z, &v)==0 ){
4040     bDflt = v;
4041   }
4042   return bDflt;
4043 }
4044 
4045 /*
4046 ** Return the Btree pointer identified by zDbName.  Return NULL if not found.
4047 */
4048 Btree *sqlite3DbNameToBtree(sqlite3 *db, const char *zDbName){
4049   int iDb = zDbName ? sqlite3FindDbName(db, zDbName) : 0;
4050   return iDb<0 ? 0 : db->aDb[iDb].pBt;
4051 }
4052 
4053 /*
4054 ** Return the filename of the database associated with a database
4055 ** connection.
4056 */
4057 const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName){
4058   Btree *pBt;
4059 #ifdef SQLITE_ENABLE_API_ARMOR
4060   if( !sqlite3SafetyCheckOk(db) ){
4061     (void)SQLITE_MISUSE_BKPT;
4062     return 0;
4063   }
4064 #endif
4065   pBt = sqlite3DbNameToBtree(db, zDbName);
4066   return pBt ? sqlite3BtreeGetFilename(pBt) : 0;
4067 }
4068 
4069 /*
4070 ** Return 1 if database is read-only or 0 if read/write.  Return -1 if
4071 ** no such database exists.
4072 */
4073 int sqlite3_db_readonly(sqlite3 *db, const char *zDbName){
4074   Btree *pBt;
4075 #ifdef SQLITE_ENABLE_API_ARMOR
4076   if( !sqlite3SafetyCheckOk(db) ){
4077     (void)SQLITE_MISUSE_BKPT;
4078     return -1;
4079   }
4080 #endif
4081   pBt = sqlite3DbNameToBtree(db, zDbName);
4082   return pBt ? sqlite3BtreeIsReadonly(pBt) : -1;
4083 }
4084 
4085 #ifdef SQLITE_ENABLE_SNAPSHOT
4086 /*
4087 ** Obtain a snapshot handle for the snapshot of database zDb currently
4088 ** being read by handle db.
4089 */
4090 int sqlite3_snapshot_get(
4091   sqlite3 *db,
4092   const char *zDb,
4093   sqlite3_snapshot **ppSnapshot
4094 ){
4095   int rc = SQLITE_ERROR;
4096 #ifndef SQLITE_OMIT_WAL
4097 
4098 #ifdef SQLITE_ENABLE_API_ARMOR
4099   if( !sqlite3SafetyCheckOk(db) ){
4100     return SQLITE_MISUSE_BKPT;
4101   }
4102 #endif
4103   sqlite3_mutex_enter(db->mutex);
4104 
4105   if( db->autoCommit==0 ){
4106     int iDb = sqlite3FindDbName(db, zDb);
4107     if( iDb==0 || iDb>1 ){
4108       Btree *pBt = db->aDb[iDb].pBt;
4109       if( 0==sqlite3BtreeIsInTrans(pBt) ){
4110         rc = sqlite3BtreeBeginTrans(pBt, 0);
4111         if( rc==SQLITE_OK ){
4112           rc = sqlite3PagerSnapshotGet(sqlite3BtreePager(pBt), ppSnapshot);
4113         }
4114       }
4115     }
4116   }
4117 
4118   sqlite3_mutex_leave(db->mutex);
4119 #endif   /* SQLITE_OMIT_WAL */
4120   return rc;
4121 }
4122 
4123 /*
4124 ** Open a read-transaction on the snapshot idendified by pSnapshot.
4125 */
4126 int sqlite3_snapshot_open(
4127   sqlite3 *db,
4128   const char *zDb,
4129   sqlite3_snapshot *pSnapshot
4130 ){
4131   int rc = SQLITE_ERROR;
4132 #ifndef SQLITE_OMIT_WAL
4133 
4134 #ifdef SQLITE_ENABLE_API_ARMOR
4135   if( !sqlite3SafetyCheckOk(db) ){
4136     return SQLITE_MISUSE_BKPT;
4137   }
4138 #endif
4139   sqlite3_mutex_enter(db->mutex);
4140   if( db->autoCommit==0 ){
4141     int iDb;
4142     iDb = sqlite3FindDbName(db, zDb);
4143     if( iDb==0 || iDb>1 ){
4144       Btree *pBt = db->aDb[iDb].pBt;
4145       if( 0==sqlite3BtreeIsInReadTrans(pBt) ){
4146         rc = sqlite3PagerSnapshotOpen(sqlite3BtreePager(pBt), pSnapshot);
4147         if( rc==SQLITE_OK ){
4148           rc = sqlite3BtreeBeginTrans(pBt, 0);
4149           sqlite3PagerSnapshotOpen(sqlite3BtreePager(pBt), 0);
4150         }
4151       }
4152     }
4153   }
4154 
4155   sqlite3_mutex_leave(db->mutex);
4156 #endif   /* SQLITE_OMIT_WAL */
4157   return rc;
4158 }
4159 
4160 /*
4161 ** Recover as many snapshots as possible from the wal file associated with
4162 ** schema zDb of database db.
4163 */
4164 int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb){
4165   int rc = SQLITE_ERROR;
4166   int iDb;
4167 #ifndef SQLITE_OMIT_WAL
4168 
4169 #ifdef SQLITE_ENABLE_API_ARMOR
4170   if( !sqlite3SafetyCheckOk(db) ){
4171     return SQLITE_MISUSE_BKPT;
4172   }
4173 #endif
4174 
4175   sqlite3_mutex_enter(db->mutex);
4176   iDb = sqlite3FindDbName(db, zDb);
4177   if( iDb==0 || iDb>1 ){
4178     Btree *pBt = db->aDb[iDb].pBt;
4179     if( 0==sqlite3BtreeIsInReadTrans(pBt) ){
4180       rc = sqlite3BtreeBeginTrans(pBt, 0);
4181       if( rc==SQLITE_OK ){
4182         rc = sqlite3PagerSnapshotRecover(sqlite3BtreePager(pBt));
4183         sqlite3BtreeCommit(pBt);
4184       }
4185     }
4186   }
4187   sqlite3_mutex_leave(db->mutex);
4188 #endif   /* SQLITE_OMIT_WAL */
4189   return rc;
4190 }
4191 
4192 /*
4193 ** Free a snapshot handle obtained from sqlite3_snapshot_get().
4194 */
4195 void sqlite3_snapshot_free(sqlite3_snapshot *pSnapshot){
4196   sqlite3_free(pSnapshot);
4197 }
4198 #endif /* SQLITE_ENABLE_SNAPSHOT */
4199 
4200 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
4201 /*
4202 ** Given the name of a compile-time option, return true if that option
4203 ** was used and false if not.
4204 **
4205 ** The name can optionally begin with "SQLITE_" but the "SQLITE_" prefix
4206 ** is not required for a match.
4207 */
4208 int sqlite3_compileoption_used(const char *zOptName){
4209   int i, n;
4210   int nOpt;
4211   const char **azCompileOpt;
4212 
4213 #if SQLITE_ENABLE_API_ARMOR
4214   if( zOptName==0 ){
4215     (void)SQLITE_MISUSE_BKPT;
4216     return 0;
4217   }
4218 #endif
4219 
4220   azCompileOpt = sqlite3CompileOptions(&nOpt);
4221 
4222   if( sqlite3StrNICmp(zOptName, "SQLITE_", 7)==0 ) zOptName += 7;
4223   n = sqlite3Strlen30(zOptName);
4224 
4225   /* Since nOpt is normally in single digits, a linear search is
4226   ** adequate. No need for a binary search. */
4227   for(i=0; i<nOpt; i++){
4228     if( sqlite3StrNICmp(zOptName, azCompileOpt[i], n)==0
4229      && sqlite3IsIdChar((unsigned char)azCompileOpt[i][n])==0
4230     ){
4231       return 1;
4232     }
4233   }
4234   return 0;
4235 }
4236 
4237 /*
4238 ** Return the N-th compile-time option string.  If N is out of range,
4239 ** return a NULL pointer.
4240 */
4241 const char *sqlite3_compileoption_get(int N){
4242   int nOpt;
4243   const char **azCompileOpt;
4244   azCompileOpt = sqlite3CompileOptions(&nOpt);
4245   if( N>=0 && N<nOpt ){
4246     return azCompileOpt[N];
4247   }
4248   return 0;
4249 }
4250 #endif /* SQLITE_OMIT_COMPILEOPTION_DIAGS */
4251