xref: /sqlite-3.40.0/src/main.c (revision 1d40cdbd)
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         { SQLITE_DBCONFIG_RESET_DATABASE,        SQLITE_ResetDatabase  },
838       };
839       unsigned int i;
840       rc = SQLITE_ERROR; /* IMP: R-42790-23372 */
841       for(i=0; i<ArraySize(aFlagOp); i++){
842         if( aFlagOp[i].op==op ){
843           int onoff = va_arg(ap, int);
844           int *pRes = va_arg(ap, int*);
845           u32 oldFlags = db->flags;
846           if( onoff>0 ){
847             db->flags |= aFlagOp[i].mask;
848           }else if( onoff==0 ){
849             db->flags &= ~aFlagOp[i].mask;
850           }
851           if( oldFlags!=db->flags ){
852             sqlite3ExpirePreparedStatements(db);
853           }
854           if( pRes ){
855             *pRes = (db->flags & aFlagOp[i].mask)!=0;
856           }
857           rc = SQLITE_OK;
858           break;
859         }
860       }
861       break;
862     }
863   }
864   va_end(ap);
865   return rc;
866 }
867 
868 
869 /*
870 ** Return true if the buffer z[0..n-1] contains all spaces.
871 */
872 static int allSpaces(const char *z, int n){
873   while( n>0 && z[n-1]==' ' ){ n--; }
874   return n==0;
875 }
876 
877 /*
878 ** This is the default collating function named "BINARY" which is always
879 ** available.
880 **
881 ** If the padFlag argument is not NULL then space padding at the end
882 ** of strings is ignored.  This implements the RTRIM collation.
883 */
884 static int binCollFunc(
885   void *padFlag,
886   int nKey1, const void *pKey1,
887   int nKey2, const void *pKey2
888 ){
889   int rc, n;
890   n = nKey1<nKey2 ? nKey1 : nKey2;
891   /* EVIDENCE-OF: R-65033-28449 The built-in BINARY collation compares
892   ** strings byte by byte using the memcmp() function from the standard C
893   ** library. */
894   assert( pKey1 && pKey2 );
895   rc = memcmp(pKey1, pKey2, n);
896   if( rc==0 ){
897     if( padFlag
898      && allSpaces(((char*)pKey1)+n, nKey1-n)
899      && allSpaces(((char*)pKey2)+n, nKey2-n)
900     ){
901       /* EVIDENCE-OF: R-31624-24737 RTRIM is like BINARY except that extra
902       ** spaces at the end of either string do not change the result. In other
903       ** words, strings will compare equal to one another as long as they
904       ** differ only in the number of spaces at the end.
905       */
906     }else{
907       rc = nKey1 - nKey2;
908     }
909   }
910   return rc;
911 }
912 
913 /*
914 ** Another built-in collating sequence: NOCASE.
915 **
916 ** This collating sequence is intended to be used for "case independent
917 ** comparison". SQLite's knowledge of upper and lower case equivalents
918 ** extends only to the 26 characters used in the English language.
919 **
920 ** At the moment there is only a UTF-8 implementation.
921 */
922 static int nocaseCollatingFunc(
923   void *NotUsed,
924   int nKey1, const void *pKey1,
925   int nKey2, const void *pKey2
926 ){
927   int r = sqlite3StrNICmp(
928       (const char *)pKey1, (const char *)pKey2, (nKey1<nKey2)?nKey1:nKey2);
929   UNUSED_PARAMETER(NotUsed);
930   if( 0==r ){
931     r = nKey1-nKey2;
932   }
933   return r;
934 }
935 
936 /*
937 ** Return the ROWID of the most recent insert
938 */
939 sqlite_int64 sqlite3_last_insert_rowid(sqlite3 *db){
940 #ifdef SQLITE_ENABLE_API_ARMOR
941   if( !sqlite3SafetyCheckOk(db) ){
942     (void)SQLITE_MISUSE_BKPT;
943     return 0;
944   }
945 #endif
946   return db->lastRowid;
947 }
948 
949 /*
950 ** Set the value returned by the sqlite3_last_insert_rowid() API function.
951 */
952 void sqlite3_set_last_insert_rowid(sqlite3 *db, sqlite3_int64 iRowid){
953 #ifdef SQLITE_ENABLE_API_ARMOR
954   if( !sqlite3SafetyCheckOk(db) ){
955     (void)SQLITE_MISUSE_BKPT;
956     return;
957   }
958 #endif
959   sqlite3_mutex_enter(db->mutex);
960   db->lastRowid = iRowid;
961   sqlite3_mutex_leave(db->mutex);
962 }
963 
964 /*
965 ** Return the number of changes in the most recent call to sqlite3_exec().
966 */
967 int sqlite3_changes(sqlite3 *db){
968 #ifdef SQLITE_ENABLE_API_ARMOR
969   if( !sqlite3SafetyCheckOk(db) ){
970     (void)SQLITE_MISUSE_BKPT;
971     return 0;
972   }
973 #endif
974   return db->nChange;
975 }
976 
977 /*
978 ** Return the number of changes since the database handle was opened.
979 */
980 int sqlite3_total_changes(sqlite3 *db){
981 #ifdef SQLITE_ENABLE_API_ARMOR
982   if( !sqlite3SafetyCheckOk(db) ){
983     (void)SQLITE_MISUSE_BKPT;
984     return 0;
985   }
986 #endif
987   return db->nTotalChange;
988 }
989 
990 /*
991 ** Close all open savepoints. This function only manipulates fields of the
992 ** database handle object, it does not close any savepoints that may be open
993 ** at the b-tree/pager level.
994 */
995 void sqlite3CloseSavepoints(sqlite3 *db){
996   while( db->pSavepoint ){
997     Savepoint *pTmp = db->pSavepoint;
998     db->pSavepoint = pTmp->pNext;
999     sqlite3DbFree(db, pTmp);
1000   }
1001   db->nSavepoint = 0;
1002   db->nStatement = 0;
1003   db->isTransactionSavepoint = 0;
1004 }
1005 
1006 /*
1007 ** Invoke the destructor function associated with FuncDef p, if any. Except,
1008 ** if this is not the last copy of the function, do not invoke it. Multiple
1009 ** copies of a single function are created when create_function() is called
1010 ** with SQLITE_ANY as the encoding.
1011 */
1012 static void functionDestroy(sqlite3 *db, FuncDef *p){
1013   FuncDestructor *pDestructor = p->u.pDestructor;
1014   if( pDestructor ){
1015     pDestructor->nRef--;
1016     if( pDestructor->nRef==0 ){
1017       pDestructor->xDestroy(pDestructor->pUserData);
1018       sqlite3DbFree(db, pDestructor);
1019     }
1020   }
1021 }
1022 
1023 /*
1024 ** Disconnect all sqlite3_vtab objects that belong to database connection
1025 ** db. This is called when db is being closed.
1026 */
1027 static void disconnectAllVtab(sqlite3 *db){
1028 #ifndef SQLITE_OMIT_VIRTUALTABLE
1029   int i;
1030   HashElem *p;
1031   sqlite3BtreeEnterAll(db);
1032   for(i=0; i<db->nDb; i++){
1033     Schema *pSchema = db->aDb[i].pSchema;
1034     if( db->aDb[i].pSchema ){
1035       for(p=sqliteHashFirst(&pSchema->tblHash); p; p=sqliteHashNext(p)){
1036         Table *pTab = (Table *)sqliteHashData(p);
1037         if( IsVirtual(pTab) ) sqlite3VtabDisconnect(db, pTab);
1038       }
1039     }
1040   }
1041   for(p=sqliteHashFirst(&db->aModule); p; p=sqliteHashNext(p)){
1042     Module *pMod = (Module *)sqliteHashData(p);
1043     if( pMod->pEpoTab ){
1044       sqlite3VtabDisconnect(db, pMod->pEpoTab);
1045     }
1046   }
1047   sqlite3VtabUnlockList(db);
1048   sqlite3BtreeLeaveAll(db);
1049 #else
1050   UNUSED_PARAMETER(db);
1051 #endif
1052 }
1053 
1054 /*
1055 ** Return TRUE if database connection db has unfinalized prepared
1056 ** statements or unfinished sqlite3_backup objects.
1057 */
1058 static int connectionIsBusy(sqlite3 *db){
1059   int j;
1060   assert( sqlite3_mutex_held(db->mutex) );
1061   if( db->pVdbe ) return 1;
1062   for(j=0; j<db->nDb; j++){
1063     Btree *pBt = db->aDb[j].pBt;
1064     if( pBt && sqlite3BtreeIsInBackup(pBt) ) return 1;
1065   }
1066   return 0;
1067 }
1068 
1069 /*
1070 ** Close an existing SQLite database
1071 */
1072 static int sqlite3Close(sqlite3 *db, int forceZombie){
1073   if( !db ){
1074     /* EVIDENCE-OF: R-63257-11740 Calling sqlite3_close() or
1075     ** sqlite3_close_v2() with a NULL pointer argument is a harmless no-op. */
1076     return SQLITE_OK;
1077   }
1078   if( !sqlite3SafetyCheckSickOrOk(db) ){
1079     return SQLITE_MISUSE_BKPT;
1080   }
1081   sqlite3_mutex_enter(db->mutex);
1082   if( db->mTrace & SQLITE_TRACE_CLOSE ){
1083     db->xTrace(SQLITE_TRACE_CLOSE, db->pTraceArg, db, 0);
1084   }
1085 
1086   /* Force xDisconnect calls on all virtual tables */
1087   disconnectAllVtab(db);
1088 
1089   /* If a transaction is open, the disconnectAllVtab() call above
1090   ** will not have called the xDisconnect() method on any virtual
1091   ** tables in the db->aVTrans[] array. The following sqlite3VtabRollback()
1092   ** call will do so. We need to do this before the check for active
1093   ** SQL statements below, as the v-table implementation may be storing
1094   ** some prepared statements internally.
1095   */
1096   sqlite3VtabRollback(db);
1097 
1098   /* Legacy behavior (sqlite3_close() behavior) is to return
1099   ** SQLITE_BUSY if the connection can not be closed immediately.
1100   */
1101   if( !forceZombie && connectionIsBusy(db) ){
1102     sqlite3ErrorWithMsg(db, SQLITE_BUSY, "unable to close due to unfinalized "
1103        "statements or unfinished backups");
1104     sqlite3_mutex_leave(db->mutex);
1105     return SQLITE_BUSY;
1106   }
1107 
1108 #ifdef SQLITE_ENABLE_SQLLOG
1109   if( sqlite3GlobalConfig.xSqllog ){
1110     /* Closing the handle. Fourth parameter is passed the value 2. */
1111     sqlite3GlobalConfig.xSqllog(sqlite3GlobalConfig.pSqllogArg, db, 0, 2);
1112   }
1113 #endif
1114 
1115   /* Convert the connection into a zombie and then close it.
1116   */
1117   db->magic = SQLITE_MAGIC_ZOMBIE;
1118   sqlite3LeaveMutexAndCloseZombie(db);
1119   return SQLITE_OK;
1120 }
1121 
1122 /*
1123 ** Two variations on the public interface for closing a database
1124 ** connection. The sqlite3_close() version returns SQLITE_BUSY and
1125 ** leaves the connection option if there are unfinalized prepared
1126 ** statements or unfinished sqlite3_backups.  The sqlite3_close_v2()
1127 ** version forces the connection to become a zombie if there are
1128 ** unclosed resources, and arranges for deallocation when the last
1129 ** prepare statement or sqlite3_backup closes.
1130 */
1131 int sqlite3_close(sqlite3 *db){ return sqlite3Close(db,0); }
1132 int sqlite3_close_v2(sqlite3 *db){ return sqlite3Close(db,1); }
1133 
1134 
1135 /*
1136 ** Close the mutex on database connection db.
1137 **
1138 ** Furthermore, if database connection db is a zombie (meaning that there
1139 ** has been a prior call to sqlite3_close(db) or sqlite3_close_v2(db)) and
1140 ** every sqlite3_stmt has now been finalized and every sqlite3_backup has
1141 ** finished, then free all resources.
1142 */
1143 void sqlite3LeaveMutexAndCloseZombie(sqlite3 *db){
1144   HashElem *i;                    /* Hash table iterator */
1145   int j;
1146 
1147   /* If there are outstanding sqlite3_stmt or sqlite3_backup objects
1148   ** or if the connection has not yet been closed by sqlite3_close_v2(),
1149   ** then just leave the mutex and return.
1150   */
1151   if( db->magic!=SQLITE_MAGIC_ZOMBIE || connectionIsBusy(db) ){
1152     sqlite3_mutex_leave(db->mutex);
1153     return;
1154   }
1155 
1156   /* If we reach this point, it means that the database connection has
1157   ** closed all sqlite3_stmt and sqlite3_backup objects and has been
1158   ** passed to sqlite3_close (meaning that it is a zombie).  Therefore,
1159   ** go ahead and free all resources.
1160   */
1161 
1162   /* If a transaction is open, roll it back. This also ensures that if
1163   ** any database schemas have been modified by an uncommitted transaction
1164   ** they are reset. And that the required b-tree mutex is held to make
1165   ** the pager rollback and schema reset an atomic operation. */
1166   sqlite3RollbackAll(db, SQLITE_OK);
1167 
1168   /* Free any outstanding Savepoint structures. */
1169   sqlite3CloseSavepoints(db);
1170 
1171   /* Close all database connections */
1172   for(j=0; j<db->nDb; j++){
1173     struct Db *pDb = &db->aDb[j];
1174     if( pDb->pBt ){
1175       sqlite3BtreeClose(pDb->pBt);
1176       pDb->pBt = 0;
1177       if( j!=1 ){
1178         pDb->pSchema = 0;
1179       }
1180     }
1181   }
1182   /* Clear the TEMP schema separately and last */
1183   if( db->aDb[1].pSchema ){
1184     sqlite3SchemaClear(db->aDb[1].pSchema);
1185   }
1186   sqlite3VtabUnlockList(db);
1187 
1188   /* Free up the array of auxiliary databases */
1189   sqlite3CollapseDatabaseArray(db);
1190   assert( db->nDb<=2 );
1191   assert( db->aDb==db->aDbStatic );
1192 
1193   /* Tell the code in notify.c that the connection no longer holds any
1194   ** locks and does not require any further unlock-notify callbacks.
1195   */
1196   sqlite3ConnectionClosed(db);
1197 
1198   for(i=sqliteHashFirst(&db->aFunc); i; i=sqliteHashNext(i)){
1199     FuncDef *pNext, *p;
1200     p = sqliteHashData(i);
1201     do{
1202       functionDestroy(db, p);
1203       pNext = p->pNext;
1204       sqlite3DbFree(db, p);
1205       p = pNext;
1206     }while( p );
1207   }
1208   sqlite3HashClear(&db->aFunc);
1209   for(i=sqliteHashFirst(&db->aCollSeq); i; i=sqliteHashNext(i)){
1210     CollSeq *pColl = (CollSeq *)sqliteHashData(i);
1211     /* Invoke any destructors registered for collation sequence user data. */
1212     for(j=0; j<3; j++){
1213       if( pColl[j].xDel ){
1214         pColl[j].xDel(pColl[j].pUser);
1215       }
1216     }
1217     sqlite3DbFree(db, pColl);
1218   }
1219   sqlite3HashClear(&db->aCollSeq);
1220 #ifndef SQLITE_OMIT_VIRTUALTABLE
1221   for(i=sqliteHashFirst(&db->aModule); i; i=sqliteHashNext(i)){
1222     Module *pMod = (Module *)sqliteHashData(i);
1223     if( pMod->xDestroy ){
1224       pMod->xDestroy(pMod->pAux);
1225     }
1226     sqlite3VtabEponymousTableClear(db, pMod);
1227     sqlite3DbFree(db, pMod);
1228   }
1229   sqlite3HashClear(&db->aModule);
1230 #endif
1231 
1232   sqlite3Error(db, SQLITE_OK); /* Deallocates any cached error strings. */
1233   sqlite3ValueFree(db->pErr);
1234   sqlite3CloseExtensions(db);
1235 #if SQLITE_USER_AUTHENTICATION
1236   sqlite3_free(db->auth.zAuthUser);
1237   sqlite3_free(db->auth.zAuthPW);
1238 #endif
1239 
1240   db->magic = SQLITE_MAGIC_ERROR;
1241 
1242   /* The temp-database schema is allocated differently from the other schema
1243   ** objects (using sqliteMalloc() directly, instead of sqlite3BtreeSchema()).
1244   ** So it needs to be freed here. Todo: Why not roll the temp schema into
1245   ** the same sqliteMalloc() as the one that allocates the database
1246   ** structure?
1247   */
1248   sqlite3DbFree(db, db->aDb[1].pSchema);
1249   sqlite3_mutex_leave(db->mutex);
1250   db->magic = SQLITE_MAGIC_CLOSED;
1251   sqlite3_mutex_free(db->mutex);
1252   assert( sqlite3LookasideUsed(db,0)==0 );
1253   if( db->lookaside.bMalloced ){
1254     sqlite3_free(db->lookaside.pStart);
1255   }
1256   sqlite3_free(db);
1257 }
1258 
1259 /*
1260 ** Rollback all database files.  If tripCode is not SQLITE_OK, then
1261 ** any write cursors are invalidated ("tripped" - as in "tripping a circuit
1262 ** breaker") and made to return tripCode if there are any further
1263 ** attempts to use that cursor.  Read cursors remain open and valid
1264 ** but are "saved" in case the table pages are moved around.
1265 */
1266 void sqlite3RollbackAll(sqlite3 *db, int tripCode){
1267   int i;
1268   int inTrans = 0;
1269   int schemaChange;
1270   assert( sqlite3_mutex_held(db->mutex) );
1271   sqlite3BeginBenignMalloc();
1272 
1273   /* Obtain all b-tree mutexes before making any calls to BtreeRollback().
1274   ** This is important in case the transaction being rolled back has
1275   ** modified the database schema. If the b-tree mutexes are not taken
1276   ** here, then another shared-cache connection might sneak in between
1277   ** the database rollback and schema reset, which can cause false
1278   ** corruption reports in some cases.  */
1279   sqlite3BtreeEnterAll(db);
1280   schemaChange = (db->mDbFlags & DBFLAG_SchemaChange)!=0 && db->init.busy==0;
1281 
1282   for(i=0; i<db->nDb; i++){
1283     Btree *p = db->aDb[i].pBt;
1284     if( p ){
1285       if( sqlite3BtreeIsInTrans(p) ){
1286         inTrans = 1;
1287       }
1288       sqlite3BtreeRollback(p, tripCode, !schemaChange);
1289     }
1290   }
1291   sqlite3VtabRollback(db);
1292   sqlite3EndBenignMalloc();
1293 
1294   if( (db->mDbFlags&DBFLAG_SchemaChange)!=0 && db->init.busy==0 ){
1295     sqlite3ExpirePreparedStatements(db);
1296     sqlite3ResetAllSchemasOfConnection(db);
1297   }
1298   sqlite3BtreeLeaveAll(db);
1299 
1300   /* Any deferred constraint violations have now been resolved. */
1301   db->nDeferredCons = 0;
1302   db->nDeferredImmCons = 0;
1303   db->flags &= ~SQLITE_DeferFKs;
1304 
1305   /* If one has been configured, invoke the rollback-hook callback */
1306   if( db->xRollbackCallback && (inTrans || !db->autoCommit) ){
1307     db->xRollbackCallback(db->pRollbackArg);
1308   }
1309 }
1310 
1311 /*
1312 ** Return a static string containing the name corresponding to the error code
1313 ** specified in the argument.
1314 */
1315 #if defined(SQLITE_NEED_ERR_NAME)
1316 const char *sqlite3ErrName(int rc){
1317   const char *zName = 0;
1318   int i, origRc = rc;
1319   for(i=0; i<2 && zName==0; i++, rc &= 0xff){
1320     switch( rc ){
1321       case SQLITE_OK:                 zName = "SQLITE_OK";                break;
1322       case SQLITE_ERROR:              zName = "SQLITE_ERROR";             break;
1323       case SQLITE_INTERNAL:           zName = "SQLITE_INTERNAL";          break;
1324       case SQLITE_PERM:               zName = "SQLITE_PERM";              break;
1325       case SQLITE_ABORT:              zName = "SQLITE_ABORT";             break;
1326       case SQLITE_ABORT_ROLLBACK:     zName = "SQLITE_ABORT_ROLLBACK";    break;
1327       case SQLITE_BUSY:               zName = "SQLITE_BUSY";              break;
1328       case SQLITE_BUSY_RECOVERY:      zName = "SQLITE_BUSY_RECOVERY";     break;
1329       case SQLITE_BUSY_SNAPSHOT:      zName = "SQLITE_BUSY_SNAPSHOT";     break;
1330       case SQLITE_LOCKED:             zName = "SQLITE_LOCKED";            break;
1331       case SQLITE_LOCKED_SHAREDCACHE: zName = "SQLITE_LOCKED_SHAREDCACHE";break;
1332       case SQLITE_NOMEM:              zName = "SQLITE_NOMEM";             break;
1333       case SQLITE_READONLY:           zName = "SQLITE_READONLY";          break;
1334       case SQLITE_READONLY_RECOVERY:  zName = "SQLITE_READONLY_RECOVERY"; break;
1335       case SQLITE_READONLY_CANTINIT:  zName = "SQLITE_READONLY_CANTINIT"; break;
1336       case SQLITE_READONLY_ROLLBACK:  zName = "SQLITE_READONLY_ROLLBACK"; break;
1337       case SQLITE_READONLY_DBMOVED:   zName = "SQLITE_READONLY_DBMOVED";  break;
1338       case SQLITE_READONLY_DIRECTORY: zName = "SQLITE_READONLY_DIRECTORY";break;
1339       case SQLITE_INTERRUPT:          zName = "SQLITE_INTERRUPT";         break;
1340       case SQLITE_IOERR:              zName = "SQLITE_IOERR";             break;
1341       case SQLITE_IOERR_READ:         zName = "SQLITE_IOERR_READ";        break;
1342       case SQLITE_IOERR_SHORT_READ:   zName = "SQLITE_IOERR_SHORT_READ";  break;
1343       case SQLITE_IOERR_WRITE:        zName = "SQLITE_IOERR_WRITE";       break;
1344       case SQLITE_IOERR_FSYNC:        zName = "SQLITE_IOERR_FSYNC";       break;
1345       case SQLITE_IOERR_DIR_FSYNC:    zName = "SQLITE_IOERR_DIR_FSYNC";   break;
1346       case SQLITE_IOERR_TRUNCATE:     zName = "SQLITE_IOERR_TRUNCATE";    break;
1347       case SQLITE_IOERR_FSTAT:        zName = "SQLITE_IOERR_FSTAT";       break;
1348       case SQLITE_IOERR_UNLOCK:       zName = "SQLITE_IOERR_UNLOCK";      break;
1349       case SQLITE_IOERR_RDLOCK:       zName = "SQLITE_IOERR_RDLOCK";      break;
1350       case SQLITE_IOERR_DELETE:       zName = "SQLITE_IOERR_DELETE";      break;
1351       case SQLITE_IOERR_NOMEM:        zName = "SQLITE_IOERR_NOMEM";       break;
1352       case SQLITE_IOERR_ACCESS:       zName = "SQLITE_IOERR_ACCESS";      break;
1353       case SQLITE_IOERR_CHECKRESERVEDLOCK:
1354                                 zName = "SQLITE_IOERR_CHECKRESERVEDLOCK"; break;
1355       case SQLITE_IOERR_LOCK:         zName = "SQLITE_IOERR_LOCK";        break;
1356       case SQLITE_IOERR_CLOSE:        zName = "SQLITE_IOERR_CLOSE";       break;
1357       case SQLITE_IOERR_DIR_CLOSE:    zName = "SQLITE_IOERR_DIR_CLOSE";   break;
1358       case SQLITE_IOERR_SHMOPEN:      zName = "SQLITE_IOERR_SHMOPEN";     break;
1359       case SQLITE_IOERR_SHMSIZE:      zName = "SQLITE_IOERR_SHMSIZE";     break;
1360       case SQLITE_IOERR_SHMLOCK:      zName = "SQLITE_IOERR_SHMLOCK";     break;
1361       case SQLITE_IOERR_SHMMAP:       zName = "SQLITE_IOERR_SHMMAP";      break;
1362       case SQLITE_IOERR_SEEK:         zName = "SQLITE_IOERR_SEEK";        break;
1363       case SQLITE_IOERR_DELETE_NOENT: zName = "SQLITE_IOERR_DELETE_NOENT";break;
1364       case SQLITE_IOERR_MMAP:         zName = "SQLITE_IOERR_MMAP";        break;
1365       case SQLITE_IOERR_GETTEMPPATH:  zName = "SQLITE_IOERR_GETTEMPPATH"; break;
1366       case SQLITE_IOERR_CONVPATH:     zName = "SQLITE_IOERR_CONVPATH";    break;
1367       case SQLITE_CORRUPT:            zName = "SQLITE_CORRUPT";           break;
1368       case SQLITE_CORRUPT_VTAB:       zName = "SQLITE_CORRUPT_VTAB";      break;
1369       case SQLITE_NOTFOUND:           zName = "SQLITE_NOTFOUND";          break;
1370       case SQLITE_FULL:               zName = "SQLITE_FULL";              break;
1371       case SQLITE_CANTOPEN:           zName = "SQLITE_CANTOPEN";          break;
1372       case SQLITE_CANTOPEN_NOTEMPDIR: zName = "SQLITE_CANTOPEN_NOTEMPDIR";break;
1373       case SQLITE_CANTOPEN_ISDIR:     zName = "SQLITE_CANTOPEN_ISDIR";    break;
1374       case SQLITE_CANTOPEN_FULLPATH:  zName = "SQLITE_CANTOPEN_FULLPATH"; break;
1375       case SQLITE_CANTOPEN_CONVPATH:  zName = "SQLITE_CANTOPEN_CONVPATH"; break;
1376       case SQLITE_PROTOCOL:           zName = "SQLITE_PROTOCOL";          break;
1377       case SQLITE_EMPTY:              zName = "SQLITE_EMPTY";             break;
1378       case SQLITE_SCHEMA:             zName = "SQLITE_SCHEMA";            break;
1379       case SQLITE_TOOBIG:             zName = "SQLITE_TOOBIG";            break;
1380       case SQLITE_CONSTRAINT:         zName = "SQLITE_CONSTRAINT";        break;
1381       case SQLITE_CONSTRAINT_UNIQUE:  zName = "SQLITE_CONSTRAINT_UNIQUE"; break;
1382       case SQLITE_CONSTRAINT_TRIGGER: zName = "SQLITE_CONSTRAINT_TRIGGER";break;
1383       case SQLITE_CONSTRAINT_FOREIGNKEY:
1384                                 zName = "SQLITE_CONSTRAINT_FOREIGNKEY";   break;
1385       case SQLITE_CONSTRAINT_CHECK:   zName = "SQLITE_CONSTRAINT_CHECK";  break;
1386       case SQLITE_CONSTRAINT_PRIMARYKEY:
1387                                 zName = "SQLITE_CONSTRAINT_PRIMARYKEY";   break;
1388       case SQLITE_CONSTRAINT_NOTNULL: zName = "SQLITE_CONSTRAINT_NOTNULL";break;
1389       case SQLITE_CONSTRAINT_COMMITHOOK:
1390                                 zName = "SQLITE_CONSTRAINT_COMMITHOOK";   break;
1391       case SQLITE_CONSTRAINT_VTAB:    zName = "SQLITE_CONSTRAINT_VTAB";   break;
1392       case SQLITE_CONSTRAINT_FUNCTION:
1393                                 zName = "SQLITE_CONSTRAINT_FUNCTION";     break;
1394       case SQLITE_CONSTRAINT_ROWID:   zName = "SQLITE_CONSTRAINT_ROWID";  break;
1395       case SQLITE_MISMATCH:           zName = "SQLITE_MISMATCH";          break;
1396       case SQLITE_MISUSE:             zName = "SQLITE_MISUSE";            break;
1397       case SQLITE_NOLFS:              zName = "SQLITE_NOLFS";             break;
1398       case SQLITE_AUTH:               zName = "SQLITE_AUTH";              break;
1399       case SQLITE_FORMAT:             zName = "SQLITE_FORMAT";            break;
1400       case SQLITE_RANGE:              zName = "SQLITE_RANGE";             break;
1401       case SQLITE_NOTADB:             zName = "SQLITE_NOTADB";            break;
1402       case SQLITE_ROW:                zName = "SQLITE_ROW";               break;
1403       case SQLITE_NOTICE:             zName = "SQLITE_NOTICE";            break;
1404       case SQLITE_NOTICE_RECOVER_WAL: zName = "SQLITE_NOTICE_RECOVER_WAL";break;
1405       case SQLITE_NOTICE_RECOVER_ROLLBACK:
1406                                 zName = "SQLITE_NOTICE_RECOVER_ROLLBACK"; break;
1407       case SQLITE_WARNING:            zName = "SQLITE_WARNING";           break;
1408       case SQLITE_WARNING_AUTOINDEX:  zName = "SQLITE_WARNING_AUTOINDEX"; break;
1409       case SQLITE_DONE:               zName = "SQLITE_DONE";              break;
1410     }
1411   }
1412   if( zName==0 ){
1413     static char zBuf[50];
1414     sqlite3_snprintf(sizeof(zBuf), zBuf, "SQLITE_UNKNOWN(%d)", origRc);
1415     zName = zBuf;
1416   }
1417   return zName;
1418 }
1419 #endif
1420 
1421 /*
1422 ** Return a static string that describes the kind of error specified in the
1423 ** argument.
1424 */
1425 const char *sqlite3ErrStr(int rc){
1426   static const char* const aMsg[] = {
1427     /* SQLITE_OK          */ "not an error",
1428     /* SQLITE_ERROR       */ "SQL logic error",
1429     /* SQLITE_INTERNAL    */ 0,
1430     /* SQLITE_PERM        */ "access permission denied",
1431     /* SQLITE_ABORT       */ "query aborted",
1432     /* SQLITE_BUSY        */ "database is locked",
1433     /* SQLITE_LOCKED      */ "database table is locked",
1434     /* SQLITE_NOMEM       */ "out of memory",
1435     /* SQLITE_READONLY    */ "attempt to write a readonly database",
1436     /* SQLITE_INTERRUPT   */ "interrupted",
1437     /* SQLITE_IOERR       */ "disk I/O error",
1438     /* SQLITE_CORRUPT     */ "database disk image is malformed",
1439     /* SQLITE_NOTFOUND    */ "unknown operation",
1440     /* SQLITE_FULL        */ "database or disk is full",
1441     /* SQLITE_CANTOPEN    */ "unable to open database file",
1442     /* SQLITE_PROTOCOL    */ "locking protocol",
1443     /* SQLITE_EMPTY       */ 0,
1444     /* SQLITE_SCHEMA      */ "database schema has changed",
1445     /* SQLITE_TOOBIG      */ "string or blob too big",
1446     /* SQLITE_CONSTRAINT  */ "constraint failed",
1447     /* SQLITE_MISMATCH    */ "datatype mismatch",
1448     /* SQLITE_MISUSE      */ "bad parameter or other API misuse",
1449 #ifdef SQLITE_DISABLE_LFS
1450     /* SQLITE_NOLFS       */ "large file support is disabled",
1451 #else
1452     /* SQLITE_NOLFS       */ 0,
1453 #endif
1454     /* SQLITE_AUTH        */ "authorization denied",
1455     /* SQLITE_FORMAT      */ 0,
1456     /* SQLITE_RANGE       */ "column index out of range",
1457     /* SQLITE_NOTADB      */ "file is not a database",
1458     /* SQLITE_NOTICE      */ "notification message",
1459     /* SQLITE_WARNING     */ "warning message",
1460   };
1461   const char *zErr = "unknown error";
1462   switch( rc ){
1463     case SQLITE_ABORT_ROLLBACK: {
1464       zErr = "abort due to ROLLBACK";
1465       break;
1466     }
1467     case SQLITE_ROW: {
1468       zErr = "another row available";
1469       break;
1470     }
1471     case SQLITE_DONE: {
1472       zErr = "no more rows available";
1473       break;
1474     }
1475     default: {
1476       rc &= 0xff;
1477       if( ALWAYS(rc>=0) && rc<ArraySize(aMsg) && aMsg[rc]!=0 ){
1478         zErr = aMsg[rc];
1479       }
1480       break;
1481     }
1482   }
1483   return zErr;
1484 }
1485 
1486 /*
1487 ** This routine implements a busy callback that sleeps and tries
1488 ** again until a timeout value is reached.  The timeout value is
1489 ** an integer number of milliseconds passed in as the first
1490 ** argument.
1491 **
1492 ** Return non-zero to retry the lock.  Return zero to stop trying
1493 ** and cause SQLite to return SQLITE_BUSY.
1494 */
1495 static int sqliteDefaultBusyCallback(
1496   void *ptr,               /* Database connection */
1497   int count,               /* Number of times table has been busy */
1498   sqlite3_file *pFile      /* The file on which the lock occurred */
1499 ){
1500 #if SQLITE_OS_WIN || HAVE_USLEEP
1501   /* This case is for systems that have support for sleeping for fractions of
1502   ** a second.  Examples:  All windows systems, unix systems with usleep() */
1503   static const u8 delays[] =
1504      { 1, 2, 5, 10, 15, 20, 25, 25,  25,  50,  50, 100 };
1505   static const u8 totals[] =
1506      { 0, 1, 3,  8, 18, 33, 53, 78, 103, 128, 178, 228 };
1507 # define NDELAY ArraySize(delays)
1508   sqlite3 *db = (sqlite3 *)ptr;
1509   int tmout = db->busyTimeout;
1510   int delay, prior;
1511 
1512 #ifdef SQLITE_ENABLE_SETLK_TIMEOUT
1513   if( sqlite3OsFileControl(pFile,SQLITE_FCNTL_LOCK_TIMEOUT,&tmout)==SQLITE_OK ){
1514     if( count ){
1515       tmout = 0;
1516       sqlite3OsFileControl(pFile, SQLITE_FCNTL_LOCK_TIMEOUT, &tmout);
1517       return 0;
1518     }else{
1519       return 1;
1520     }
1521   }
1522 #else
1523   UNUSED_PARAMETER(pFile);
1524 #endif
1525   assert( count>=0 );
1526   if( count < NDELAY ){
1527     delay = delays[count];
1528     prior = totals[count];
1529   }else{
1530     delay = delays[NDELAY-1];
1531     prior = totals[NDELAY-1] + delay*(count-(NDELAY-1));
1532   }
1533   if( prior + delay > tmout ){
1534     delay = tmout - prior;
1535     if( delay<=0 ) return 0;
1536   }
1537   sqlite3OsSleep(db->pVfs, delay*1000);
1538   return 1;
1539 #else
1540   /* This case for unix systems that lack usleep() support.  Sleeping
1541   ** must be done in increments of whole seconds */
1542   sqlite3 *db = (sqlite3 *)ptr;
1543   int tmout = ((sqlite3 *)ptr)->busyTimeout;
1544   UNUSED_PARAMETER(pFile);
1545   if( (count+1)*1000 > tmout ){
1546     return 0;
1547   }
1548   sqlite3OsSleep(db->pVfs, 1000000);
1549   return 1;
1550 #endif
1551 }
1552 
1553 /*
1554 ** Invoke the given busy handler.
1555 **
1556 ** This routine is called when an operation failed to acquire a
1557 ** lock on VFS file pFile.
1558 **
1559 ** If this routine returns non-zero, the lock is retried.  If it
1560 ** returns 0, the operation aborts with an SQLITE_BUSY error.
1561 */
1562 int sqlite3InvokeBusyHandler(BusyHandler *p, sqlite3_file *pFile){
1563   int rc;
1564   if( p->xBusyHandler==0 || p->nBusy<0 ) return 0;
1565   if( p->bExtraFileArg ){
1566     /* Add an extra parameter with the pFile pointer to the end of the
1567     ** callback argument list */
1568     int (*xTra)(void*,int,sqlite3_file*);
1569     xTra = (int(*)(void*,int,sqlite3_file*))p->xBusyHandler;
1570     rc = xTra(p->pBusyArg, p->nBusy, pFile);
1571   }else{
1572     /* Legacy style busy handler callback */
1573     rc = p->xBusyHandler(p->pBusyArg, p->nBusy);
1574   }
1575   if( rc==0 ){
1576     p->nBusy = -1;
1577   }else{
1578     p->nBusy++;
1579   }
1580   return rc;
1581 }
1582 
1583 /*
1584 ** This routine sets the busy callback for an Sqlite database to the
1585 ** given callback function with the given argument.
1586 */
1587 int sqlite3_busy_handler(
1588   sqlite3 *db,
1589   int (*xBusy)(void*,int),
1590   void *pArg
1591 ){
1592 #ifdef SQLITE_ENABLE_API_ARMOR
1593   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
1594 #endif
1595   sqlite3_mutex_enter(db->mutex);
1596   db->busyHandler.xBusyHandler = xBusy;
1597   db->busyHandler.pBusyArg = pArg;
1598   db->busyHandler.nBusy = 0;
1599   db->busyHandler.bExtraFileArg = 0;
1600   db->busyTimeout = 0;
1601   sqlite3_mutex_leave(db->mutex);
1602   return SQLITE_OK;
1603 }
1604 
1605 #ifndef SQLITE_OMIT_PROGRESS_CALLBACK
1606 /*
1607 ** This routine sets the progress callback for an Sqlite database to the
1608 ** given callback function with the given argument. The progress callback will
1609 ** be invoked every nOps opcodes.
1610 */
1611 void sqlite3_progress_handler(
1612   sqlite3 *db,
1613   int nOps,
1614   int (*xProgress)(void*),
1615   void *pArg
1616 ){
1617 #ifdef SQLITE_ENABLE_API_ARMOR
1618   if( !sqlite3SafetyCheckOk(db) ){
1619     (void)SQLITE_MISUSE_BKPT;
1620     return;
1621   }
1622 #endif
1623   sqlite3_mutex_enter(db->mutex);
1624   if( nOps>0 ){
1625     db->xProgress = xProgress;
1626     db->nProgressOps = (unsigned)nOps;
1627     db->pProgressArg = pArg;
1628   }else{
1629     db->xProgress = 0;
1630     db->nProgressOps = 0;
1631     db->pProgressArg = 0;
1632   }
1633   sqlite3_mutex_leave(db->mutex);
1634 }
1635 #endif
1636 
1637 
1638 /*
1639 ** This routine installs a default busy handler that waits for the
1640 ** specified number of milliseconds before returning 0.
1641 */
1642 int sqlite3_busy_timeout(sqlite3 *db, int ms){
1643 #ifdef SQLITE_ENABLE_API_ARMOR
1644   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
1645 #endif
1646   if( ms>0 ){
1647     sqlite3_busy_handler(db, (int(*)(void*,int))sqliteDefaultBusyCallback,
1648                              (void*)db);
1649     db->busyTimeout = ms;
1650     db->busyHandler.bExtraFileArg = 1;
1651   }else{
1652     sqlite3_busy_handler(db, 0, 0);
1653   }
1654   return SQLITE_OK;
1655 }
1656 
1657 /*
1658 ** Cause any pending operation to stop at its earliest opportunity.
1659 */
1660 void sqlite3_interrupt(sqlite3 *db){
1661 #ifdef SQLITE_ENABLE_API_ARMOR
1662   if( !sqlite3SafetyCheckOk(db) && (db==0 || db->magic!=SQLITE_MAGIC_ZOMBIE) ){
1663     (void)SQLITE_MISUSE_BKPT;
1664     return;
1665   }
1666 #endif
1667   db->u1.isInterrupted = 1;
1668 }
1669 
1670 
1671 /*
1672 ** This function is exactly the same as sqlite3_create_function(), except
1673 ** that it is designed to be called by internal code. The difference is
1674 ** that if a malloc() fails in sqlite3_create_function(), an error code
1675 ** is returned and the mallocFailed flag cleared.
1676 */
1677 int sqlite3CreateFunc(
1678   sqlite3 *db,
1679   const char *zFunctionName,
1680   int nArg,
1681   int enc,
1682   void *pUserData,
1683   void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
1684   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
1685   void (*xFinal)(sqlite3_context*),
1686   FuncDestructor *pDestructor
1687 ){
1688   FuncDef *p;
1689   int nName;
1690   int extraFlags;
1691 
1692   assert( sqlite3_mutex_held(db->mutex) );
1693   if( zFunctionName==0 ||
1694       (xSFunc && (xFinal || xStep)) ||
1695       (!xSFunc && (xFinal && !xStep)) ||
1696       (!xSFunc && (!xFinal && xStep)) ||
1697       (nArg<-1 || nArg>SQLITE_MAX_FUNCTION_ARG) ||
1698       (255<(nName = sqlite3Strlen30( zFunctionName))) ){
1699     return SQLITE_MISUSE_BKPT;
1700   }
1701 
1702   assert( SQLITE_FUNC_CONSTANT==SQLITE_DETERMINISTIC );
1703   extraFlags = enc &  SQLITE_DETERMINISTIC;
1704   enc &= (SQLITE_FUNC_ENCMASK|SQLITE_ANY);
1705 
1706 #ifndef SQLITE_OMIT_UTF16
1707   /* If SQLITE_UTF16 is specified as the encoding type, transform this
1708   ** to one of SQLITE_UTF16LE or SQLITE_UTF16BE using the
1709   ** SQLITE_UTF16NATIVE macro. SQLITE_UTF16 is not used internally.
1710   **
1711   ** If SQLITE_ANY is specified, add three versions of the function
1712   ** to the hash table.
1713   */
1714   if( enc==SQLITE_UTF16 ){
1715     enc = SQLITE_UTF16NATIVE;
1716   }else if( enc==SQLITE_ANY ){
1717     int rc;
1718     rc = sqlite3CreateFunc(db, zFunctionName, nArg, SQLITE_UTF8|extraFlags,
1719          pUserData, xSFunc, xStep, xFinal, pDestructor);
1720     if( rc==SQLITE_OK ){
1721       rc = sqlite3CreateFunc(db, zFunctionName, nArg, SQLITE_UTF16LE|extraFlags,
1722           pUserData, xSFunc, xStep, xFinal, pDestructor);
1723     }
1724     if( rc!=SQLITE_OK ){
1725       return rc;
1726     }
1727     enc = SQLITE_UTF16BE;
1728   }
1729 #else
1730   enc = SQLITE_UTF8;
1731 #endif
1732 
1733   /* Check if an existing function is being overridden or deleted. If so,
1734   ** and there are active VMs, then return SQLITE_BUSY. If a function
1735   ** is being overridden/deleted but there are no active VMs, allow the
1736   ** operation to continue but invalidate all precompiled statements.
1737   */
1738   p = sqlite3FindFunction(db, zFunctionName, nArg, (u8)enc, 0);
1739   if( p && (p->funcFlags & SQLITE_FUNC_ENCMASK)==enc && p->nArg==nArg ){
1740     if( db->nVdbeActive ){
1741       sqlite3ErrorWithMsg(db, SQLITE_BUSY,
1742         "unable to delete/modify user-function due to active statements");
1743       assert( !db->mallocFailed );
1744       return SQLITE_BUSY;
1745     }else{
1746       sqlite3ExpirePreparedStatements(db);
1747     }
1748   }
1749 
1750   p = sqlite3FindFunction(db, zFunctionName, nArg, (u8)enc, 1);
1751   assert(p || db->mallocFailed);
1752   if( !p ){
1753     return SQLITE_NOMEM_BKPT;
1754   }
1755 
1756   /* If an older version of the function with a configured destructor is
1757   ** being replaced invoke the destructor function here. */
1758   functionDestroy(db, p);
1759 
1760   if( pDestructor ){
1761     pDestructor->nRef++;
1762   }
1763   p->u.pDestructor = pDestructor;
1764   p->funcFlags = (p->funcFlags & SQLITE_FUNC_ENCMASK) | extraFlags;
1765   testcase( p->funcFlags & SQLITE_DETERMINISTIC );
1766   p->xSFunc = xSFunc ? xSFunc : xStep;
1767   p->xFinalize = xFinal;
1768   p->pUserData = pUserData;
1769   p->nArg = (u16)nArg;
1770   return SQLITE_OK;
1771 }
1772 
1773 /*
1774 ** Create new user functions.
1775 */
1776 int sqlite3_create_function(
1777   sqlite3 *db,
1778   const char *zFunc,
1779   int nArg,
1780   int enc,
1781   void *p,
1782   void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
1783   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
1784   void (*xFinal)(sqlite3_context*)
1785 ){
1786   return sqlite3_create_function_v2(db, zFunc, nArg, enc, p, xSFunc, xStep,
1787                                     xFinal, 0);
1788 }
1789 
1790 int sqlite3_create_function_v2(
1791   sqlite3 *db,
1792   const char *zFunc,
1793   int nArg,
1794   int enc,
1795   void *p,
1796   void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
1797   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
1798   void (*xFinal)(sqlite3_context*),
1799   void (*xDestroy)(void *)
1800 ){
1801   int rc = SQLITE_ERROR;
1802   FuncDestructor *pArg = 0;
1803 
1804 #ifdef SQLITE_ENABLE_API_ARMOR
1805   if( !sqlite3SafetyCheckOk(db) ){
1806     return SQLITE_MISUSE_BKPT;
1807   }
1808 #endif
1809   sqlite3_mutex_enter(db->mutex);
1810   if( xDestroy ){
1811     pArg = (FuncDestructor *)sqlite3Malloc(sizeof(FuncDestructor));
1812     if( !pArg ){
1813       sqlite3OomFault(db);
1814       xDestroy(p);
1815       goto out;
1816     }
1817     pArg->nRef = 0;
1818     pArg->xDestroy = xDestroy;
1819     pArg->pUserData = p;
1820   }
1821   rc = sqlite3CreateFunc(db, zFunc, nArg, enc, p, xSFunc, xStep, xFinal, pArg);
1822   if( pArg && pArg->nRef==0 ){
1823     assert( rc!=SQLITE_OK );
1824     xDestroy(p);
1825     sqlite3_free(pArg);
1826   }
1827 
1828  out:
1829   rc = sqlite3ApiExit(db, rc);
1830   sqlite3_mutex_leave(db->mutex);
1831   return rc;
1832 }
1833 
1834 #ifndef SQLITE_OMIT_UTF16
1835 int sqlite3_create_function16(
1836   sqlite3 *db,
1837   const void *zFunctionName,
1838   int nArg,
1839   int eTextRep,
1840   void *p,
1841   void (*xSFunc)(sqlite3_context*,int,sqlite3_value**),
1842   void (*xStep)(sqlite3_context*,int,sqlite3_value**),
1843   void (*xFinal)(sqlite3_context*)
1844 ){
1845   int rc;
1846   char *zFunc8;
1847 
1848 #ifdef SQLITE_ENABLE_API_ARMOR
1849   if( !sqlite3SafetyCheckOk(db) || zFunctionName==0 ) return SQLITE_MISUSE_BKPT;
1850 #endif
1851   sqlite3_mutex_enter(db->mutex);
1852   assert( !db->mallocFailed );
1853   zFunc8 = sqlite3Utf16to8(db, zFunctionName, -1, SQLITE_UTF16NATIVE);
1854   rc = sqlite3CreateFunc(db, zFunc8, nArg, eTextRep, p, xSFunc,xStep,xFinal,0);
1855   sqlite3DbFree(db, zFunc8);
1856   rc = sqlite3ApiExit(db, rc);
1857   sqlite3_mutex_leave(db->mutex);
1858   return rc;
1859 }
1860 #endif
1861 
1862 
1863 /*
1864 ** The following is the implementation of an SQL function that always
1865 ** fails with an error message stating that the function is used in the
1866 ** wrong context.  The sqlite3_overload_function() API might construct
1867 ** SQL function that use this routine so that the functions will exist
1868 ** for name resolution but are actually overloaded by the xFindFunction
1869 ** method of virtual tables.
1870 */
1871 static void sqlite3InvalidFunction(
1872   sqlite3_context *context,  /* The function calling context */
1873   int NotUsed,               /* Number of arguments to the function */
1874   sqlite3_value **NotUsed2   /* Value of each argument */
1875 ){
1876   const char *zName = (const char*)sqlite3_user_data(context);
1877   char *zErr;
1878   UNUSED_PARAMETER2(NotUsed, NotUsed2);
1879   zErr = sqlite3_mprintf(
1880       "unable to use function %s in the requested context", zName);
1881   sqlite3_result_error(context, zErr, -1);
1882   sqlite3_free(zErr);
1883 }
1884 
1885 /*
1886 ** Declare that a function has been overloaded by a virtual table.
1887 **
1888 ** If the function already exists as a regular global function, then
1889 ** this routine is a no-op.  If the function does not exist, then create
1890 ** a new one that always throws a run-time error.
1891 **
1892 ** When virtual tables intend to provide an overloaded function, they
1893 ** should call this routine to make sure the global function exists.
1894 ** A global function must exist in order for name resolution to work
1895 ** properly.
1896 */
1897 int sqlite3_overload_function(
1898   sqlite3 *db,
1899   const char *zName,
1900   int nArg
1901 ){
1902   int rc;
1903   char *zCopy;
1904 
1905 #ifdef SQLITE_ENABLE_API_ARMOR
1906   if( !sqlite3SafetyCheckOk(db) || zName==0 || nArg<-2 ){
1907     return SQLITE_MISUSE_BKPT;
1908   }
1909 #endif
1910   sqlite3_mutex_enter(db->mutex);
1911   rc = sqlite3FindFunction(db, zName, nArg, SQLITE_UTF8, 0)!=0;
1912   sqlite3_mutex_leave(db->mutex);
1913   if( rc ) return SQLITE_OK;
1914   zCopy = sqlite3_mprintf(zName);
1915   if( zCopy==0 ) return SQLITE_NOMEM;
1916   return sqlite3_create_function_v2(db, zName, nArg, SQLITE_UTF8,
1917                            zCopy, sqlite3InvalidFunction, 0, 0, sqlite3_free);
1918 }
1919 
1920 #ifndef SQLITE_OMIT_TRACE
1921 /*
1922 ** Register a trace function.  The pArg from the previously registered trace
1923 ** is returned.
1924 **
1925 ** A NULL trace function means that no tracing is executes.  A non-NULL
1926 ** trace is a pointer to a function that is invoked at the start of each
1927 ** SQL statement.
1928 */
1929 #ifndef SQLITE_OMIT_DEPRECATED
1930 void *sqlite3_trace(sqlite3 *db, void(*xTrace)(void*,const char*), void *pArg){
1931   void *pOld;
1932 
1933 #ifdef SQLITE_ENABLE_API_ARMOR
1934   if( !sqlite3SafetyCheckOk(db) ){
1935     (void)SQLITE_MISUSE_BKPT;
1936     return 0;
1937   }
1938 #endif
1939   sqlite3_mutex_enter(db->mutex);
1940   pOld = db->pTraceArg;
1941   db->mTrace = xTrace ? SQLITE_TRACE_LEGACY : 0;
1942   db->xTrace = (int(*)(u32,void*,void*,void*))xTrace;
1943   db->pTraceArg = pArg;
1944   sqlite3_mutex_leave(db->mutex);
1945   return pOld;
1946 }
1947 #endif /* SQLITE_OMIT_DEPRECATED */
1948 
1949 /* Register a trace callback using the version-2 interface.
1950 */
1951 int sqlite3_trace_v2(
1952   sqlite3 *db,                               /* Trace this connection */
1953   unsigned mTrace,                           /* Mask of events to be traced */
1954   int(*xTrace)(unsigned,void*,void*,void*),  /* Callback to invoke */
1955   void *pArg                                 /* Context */
1956 ){
1957 #ifdef SQLITE_ENABLE_API_ARMOR
1958   if( !sqlite3SafetyCheckOk(db) ){
1959     return SQLITE_MISUSE_BKPT;
1960   }
1961 #endif
1962   sqlite3_mutex_enter(db->mutex);
1963   if( mTrace==0 ) xTrace = 0;
1964   if( xTrace==0 ) mTrace = 0;
1965   db->mTrace = mTrace;
1966   db->xTrace = xTrace;
1967   db->pTraceArg = pArg;
1968   sqlite3_mutex_leave(db->mutex);
1969   return SQLITE_OK;
1970 }
1971 
1972 #ifndef SQLITE_OMIT_DEPRECATED
1973 /*
1974 ** Register a profile function.  The pArg from the previously registered
1975 ** profile function is returned.
1976 **
1977 ** A NULL profile function means that no profiling is executes.  A non-NULL
1978 ** profile is a pointer to a function that is invoked at the conclusion of
1979 ** each SQL statement that is run.
1980 */
1981 void *sqlite3_profile(
1982   sqlite3 *db,
1983   void (*xProfile)(void*,const char*,sqlite_uint64),
1984   void *pArg
1985 ){
1986   void *pOld;
1987 
1988 #ifdef SQLITE_ENABLE_API_ARMOR
1989   if( !sqlite3SafetyCheckOk(db) ){
1990     (void)SQLITE_MISUSE_BKPT;
1991     return 0;
1992   }
1993 #endif
1994   sqlite3_mutex_enter(db->mutex);
1995   pOld = db->pProfileArg;
1996   db->xProfile = xProfile;
1997   db->pProfileArg = pArg;
1998   sqlite3_mutex_leave(db->mutex);
1999   return pOld;
2000 }
2001 #endif /* SQLITE_OMIT_DEPRECATED */
2002 #endif /* SQLITE_OMIT_TRACE */
2003 
2004 /*
2005 ** Register a function to be invoked when a transaction commits.
2006 ** If the invoked function returns non-zero, then the commit becomes a
2007 ** rollback.
2008 */
2009 void *sqlite3_commit_hook(
2010   sqlite3 *db,              /* Attach the hook to this database */
2011   int (*xCallback)(void*),  /* Function to invoke on each commit */
2012   void *pArg                /* Argument to the function */
2013 ){
2014   void *pOld;
2015 
2016 #ifdef SQLITE_ENABLE_API_ARMOR
2017   if( !sqlite3SafetyCheckOk(db) ){
2018     (void)SQLITE_MISUSE_BKPT;
2019     return 0;
2020   }
2021 #endif
2022   sqlite3_mutex_enter(db->mutex);
2023   pOld = db->pCommitArg;
2024   db->xCommitCallback = xCallback;
2025   db->pCommitArg = pArg;
2026   sqlite3_mutex_leave(db->mutex);
2027   return pOld;
2028 }
2029 
2030 /*
2031 ** Register a callback to be invoked each time a row is updated,
2032 ** inserted or deleted using this database connection.
2033 */
2034 void *sqlite3_update_hook(
2035   sqlite3 *db,              /* Attach the hook to this database */
2036   void (*xCallback)(void*,int,char const *,char const *,sqlite_int64),
2037   void *pArg                /* Argument to the function */
2038 ){
2039   void *pRet;
2040 
2041 #ifdef SQLITE_ENABLE_API_ARMOR
2042   if( !sqlite3SafetyCheckOk(db) ){
2043     (void)SQLITE_MISUSE_BKPT;
2044     return 0;
2045   }
2046 #endif
2047   sqlite3_mutex_enter(db->mutex);
2048   pRet = db->pUpdateArg;
2049   db->xUpdateCallback = xCallback;
2050   db->pUpdateArg = pArg;
2051   sqlite3_mutex_leave(db->mutex);
2052   return pRet;
2053 }
2054 
2055 /*
2056 ** Register a callback to be invoked each time a transaction is rolled
2057 ** back by this database connection.
2058 */
2059 void *sqlite3_rollback_hook(
2060   sqlite3 *db,              /* Attach the hook to this database */
2061   void (*xCallback)(void*), /* Callback function */
2062   void *pArg                /* Argument to the function */
2063 ){
2064   void *pRet;
2065 
2066 #ifdef SQLITE_ENABLE_API_ARMOR
2067   if( !sqlite3SafetyCheckOk(db) ){
2068     (void)SQLITE_MISUSE_BKPT;
2069     return 0;
2070   }
2071 #endif
2072   sqlite3_mutex_enter(db->mutex);
2073   pRet = db->pRollbackArg;
2074   db->xRollbackCallback = xCallback;
2075   db->pRollbackArg = pArg;
2076   sqlite3_mutex_leave(db->mutex);
2077   return pRet;
2078 }
2079 
2080 #ifdef SQLITE_ENABLE_PREUPDATE_HOOK
2081 /*
2082 ** Register a callback to be invoked each time a row is updated,
2083 ** inserted or deleted using this database connection.
2084 */
2085 void *sqlite3_preupdate_hook(
2086   sqlite3 *db,              /* Attach the hook to this database */
2087   void(*xCallback)(         /* Callback function */
2088     void*,sqlite3*,int,char const*,char const*,sqlite3_int64,sqlite3_int64),
2089   void *pArg                /* First callback argument */
2090 ){
2091   void *pRet;
2092   sqlite3_mutex_enter(db->mutex);
2093   pRet = db->pPreUpdateArg;
2094   db->xPreUpdateCallback = xCallback;
2095   db->pPreUpdateArg = pArg;
2096   sqlite3_mutex_leave(db->mutex);
2097   return pRet;
2098 }
2099 #endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
2100 
2101 #ifndef SQLITE_OMIT_WAL
2102 /*
2103 ** The sqlite3_wal_hook() callback registered by sqlite3_wal_autocheckpoint().
2104 ** Invoke sqlite3_wal_checkpoint if the number of frames in the log file
2105 ** is greater than sqlite3.pWalArg cast to an integer (the value configured by
2106 ** wal_autocheckpoint()).
2107 */
2108 int sqlite3WalDefaultHook(
2109   void *pClientData,     /* Argument */
2110   sqlite3 *db,           /* Connection */
2111   const char *zDb,       /* Database */
2112   int nFrame             /* Size of WAL */
2113 ){
2114   if( nFrame>=SQLITE_PTR_TO_INT(pClientData) ){
2115     sqlite3BeginBenignMalloc();
2116     sqlite3_wal_checkpoint(db, zDb);
2117     sqlite3EndBenignMalloc();
2118   }
2119   return SQLITE_OK;
2120 }
2121 #endif /* SQLITE_OMIT_WAL */
2122 
2123 /*
2124 ** Configure an sqlite3_wal_hook() callback to automatically checkpoint
2125 ** a database after committing a transaction if there are nFrame or
2126 ** more frames in the log file. Passing zero or a negative value as the
2127 ** nFrame parameter disables automatic checkpoints entirely.
2128 **
2129 ** The callback registered by this function replaces any existing callback
2130 ** registered using sqlite3_wal_hook(). Likewise, registering a callback
2131 ** using sqlite3_wal_hook() disables the automatic checkpoint mechanism
2132 ** configured by this function.
2133 */
2134 int sqlite3_wal_autocheckpoint(sqlite3 *db, int nFrame){
2135 #ifdef SQLITE_OMIT_WAL
2136   UNUSED_PARAMETER(db);
2137   UNUSED_PARAMETER(nFrame);
2138 #else
2139 #ifdef SQLITE_ENABLE_API_ARMOR
2140   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
2141 #endif
2142   if( nFrame>0 ){
2143     sqlite3_wal_hook(db, sqlite3WalDefaultHook, SQLITE_INT_TO_PTR(nFrame));
2144   }else{
2145     sqlite3_wal_hook(db, 0, 0);
2146   }
2147 #endif
2148   return SQLITE_OK;
2149 }
2150 
2151 /*
2152 ** Register a callback to be invoked each time a transaction is written
2153 ** into the write-ahead-log by this database connection.
2154 */
2155 void *sqlite3_wal_hook(
2156   sqlite3 *db,                    /* Attach the hook to this db handle */
2157   int(*xCallback)(void *, sqlite3*, const char*, int),
2158   void *pArg                      /* First argument passed to xCallback() */
2159 ){
2160 #ifndef SQLITE_OMIT_WAL
2161   void *pRet;
2162 #ifdef SQLITE_ENABLE_API_ARMOR
2163   if( !sqlite3SafetyCheckOk(db) ){
2164     (void)SQLITE_MISUSE_BKPT;
2165     return 0;
2166   }
2167 #endif
2168   sqlite3_mutex_enter(db->mutex);
2169   pRet = db->pWalArg;
2170   db->xWalCallback = xCallback;
2171   db->pWalArg = pArg;
2172   sqlite3_mutex_leave(db->mutex);
2173   return pRet;
2174 #else
2175   return 0;
2176 #endif
2177 }
2178 
2179 /*
2180 ** Checkpoint database zDb.
2181 */
2182 int sqlite3_wal_checkpoint_v2(
2183   sqlite3 *db,                    /* Database handle */
2184   const char *zDb,                /* Name of attached database (or NULL) */
2185   int eMode,                      /* SQLITE_CHECKPOINT_* value */
2186   int *pnLog,                     /* OUT: Size of WAL log in frames */
2187   int *pnCkpt                     /* OUT: Total number of frames checkpointed */
2188 ){
2189 #ifdef SQLITE_OMIT_WAL
2190   return SQLITE_OK;
2191 #else
2192   int rc;                         /* Return code */
2193   int iDb = SQLITE_MAX_ATTACHED;  /* sqlite3.aDb[] index of db to checkpoint */
2194 
2195 #ifdef SQLITE_ENABLE_API_ARMOR
2196   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
2197 #endif
2198 
2199   /* Initialize the output variables to -1 in case an error occurs. */
2200   if( pnLog ) *pnLog = -1;
2201   if( pnCkpt ) *pnCkpt = -1;
2202 
2203   assert( SQLITE_CHECKPOINT_PASSIVE==0 );
2204   assert( SQLITE_CHECKPOINT_FULL==1 );
2205   assert( SQLITE_CHECKPOINT_RESTART==2 );
2206   assert( SQLITE_CHECKPOINT_TRUNCATE==3 );
2207   if( eMode<SQLITE_CHECKPOINT_PASSIVE || eMode>SQLITE_CHECKPOINT_TRUNCATE ){
2208     /* EVIDENCE-OF: R-03996-12088 The M parameter must be a valid checkpoint
2209     ** mode: */
2210     return SQLITE_MISUSE;
2211   }
2212 
2213   sqlite3_mutex_enter(db->mutex);
2214   if( zDb && zDb[0] ){
2215     iDb = sqlite3FindDbName(db, zDb);
2216   }
2217   if( iDb<0 ){
2218     rc = SQLITE_ERROR;
2219     sqlite3ErrorWithMsg(db, SQLITE_ERROR, "unknown database: %s", zDb);
2220   }else{
2221     db->busyHandler.nBusy = 0;
2222     rc = sqlite3Checkpoint(db, iDb, eMode, pnLog, pnCkpt);
2223     sqlite3Error(db, rc);
2224   }
2225   rc = sqlite3ApiExit(db, rc);
2226 
2227   /* If there are no active statements, clear the interrupt flag at this
2228   ** point.  */
2229   if( db->nVdbeActive==0 ){
2230     db->u1.isInterrupted = 0;
2231   }
2232 
2233   sqlite3_mutex_leave(db->mutex);
2234   return rc;
2235 #endif
2236 }
2237 
2238 
2239 /*
2240 ** Checkpoint database zDb. If zDb is NULL, or if the buffer zDb points
2241 ** to contains a zero-length string, all attached databases are
2242 ** checkpointed.
2243 */
2244 int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb){
2245   /* EVIDENCE-OF: R-41613-20553 The sqlite3_wal_checkpoint(D,X) is equivalent to
2246   ** sqlite3_wal_checkpoint_v2(D,X,SQLITE_CHECKPOINT_PASSIVE,0,0). */
2247   return sqlite3_wal_checkpoint_v2(db,zDb,SQLITE_CHECKPOINT_PASSIVE,0,0);
2248 }
2249 
2250 #ifndef SQLITE_OMIT_WAL
2251 /*
2252 ** Run a checkpoint on database iDb. This is a no-op if database iDb is
2253 ** not currently open in WAL mode.
2254 **
2255 ** If a transaction is open on the database being checkpointed, this
2256 ** function returns SQLITE_LOCKED and a checkpoint is not attempted. If
2257 ** an error occurs while running the checkpoint, an SQLite error code is
2258 ** returned (i.e. SQLITE_IOERR). Otherwise, SQLITE_OK.
2259 **
2260 ** The mutex on database handle db should be held by the caller. The mutex
2261 ** associated with the specific b-tree being checkpointed is taken by
2262 ** this function while the checkpoint is running.
2263 **
2264 ** If iDb is passed SQLITE_MAX_ATTACHED, then all attached databases are
2265 ** checkpointed. If an error is encountered it is returned immediately -
2266 ** no attempt is made to checkpoint any remaining databases.
2267 **
2268 ** Parameter eMode is one of SQLITE_CHECKPOINT_PASSIVE, FULL, RESTART
2269 ** or TRUNCATE.
2270 */
2271 int sqlite3Checkpoint(sqlite3 *db, int iDb, int eMode, int *pnLog, int *pnCkpt){
2272   int rc = SQLITE_OK;             /* Return code */
2273   int i;                          /* Used to iterate through attached dbs */
2274   int bBusy = 0;                  /* True if SQLITE_BUSY has been encountered */
2275 
2276   assert( sqlite3_mutex_held(db->mutex) );
2277   assert( !pnLog || *pnLog==-1 );
2278   assert( !pnCkpt || *pnCkpt==-1 );
2279 
2280   for(i=0; i<db->nDb && rc==SQLITE_OK; i++){
2281     if( i==iDb || iDb==SQLITE_MAX_ATTACHED ){
2282       rc = sqlite3BtreeCheckpoint(db->aDb[i].pBt, eMode, pnLog, pnCkpt);
2283       pnLog = 0;
2284       pnCkpt = 0;
2285       if( rc==SQLITE_BUSY ){
2286         bBusy = 1;
2287         rc = SQLITE_OK;
2288       }
2289     }
2290   }
2291 
2292   return (rc==SQLITE_OK && bBusy) ? SQLITE_BUSY : rc;
2293 }
2294 #endif /* SQLITE_OMIT_WAL */
2295 
2296 /*
2297 ** This function returns true if main-memory should be used instead of
2298 ** a temporary file for transient pager files and statement journals.
2299 ** The value returned depends on the value of db->temp_store (runtime
2300 ** parameter) and the compile time value of SQLITE_TEMP_STORE. The
2301 ** following table describes the relationship between these two values
2302 ** and this functions return value.
2303 **
2304 **   SQLITE_TEMP_STORE     db->temp_store     Location of temporary database
2305 **   -----------------     --------------     ------------------------------
2306 **   0                     any                file      (return 0)
2307 **   1                     1                  file      (return 0)
2308 **   1                     2                  memory    (return 1)
2309 **   1                     0                  file      (return 0)
2310 **   2                     1                  file      (return 0)
2311 **   2                     2                  memory    (return 1)
2312 **   2                     0                  memory    (return 1)
2313 **   3                     any                memory    (return 1)
2314 */
2315 int sqlite3TempInMemory(const sqlite3 *db){
2316 #if SQLITE_TEMP_STORE==1
2317   return ( db->temp_store==2 );
2318 #endif
2319 #if SQLITE_TEMP_STORE==2
2320   return ( db->temp_store!=1 );
2321 #endif
2322 #if SQLITE_TEMP_STORE==3
2323   UNUSED_PARAMETER(db);
2324   return 1;
2325 #endif
2326 #if SQLITE_TEMP_STORE<1 || SQLITE_TEMP_STORE>3
2327   UNUSED_PARAMETER(db);
2328   return 0;
2329 #endif
2330 }
2331 
2332 /*
2333 ** Return UTF-8 encoded English language explanation of the most recent
2334 ** error.
2335 */
2336 const char *sqlite3_errmsg(sqlite3 *db){
2337   const char *z;
2338   if( !db ){
2339     return sqlite3ErrStr(SQLITE_NOMEM_BKPT);
2340   }
2341   if( !sqlite3SafetyCheckSickOrOk(db) ){
2342     return sqlite3ErrStr(SQLITE_MISUSE_BKPT);
2343   }
2344   sqlite3_mutex_enter(db->mutex);
2345   if( db->mallocFailed ){
2346     z = sqlite3ErrStr(SQLITE_NOMEM_BKPT);
2347   }else{
2348     testcase( db->pErr==0 );
2349     z = (char*)sqlite3_value_text(db->pErr);
2350     assert( !db->mallocFailed );
2351     if( z==0 ){
2352       z = sqlite3ErrStr(db->errCode);
2353     }
2354   }
2355   sqlite3_mutex_leave(db->mutex);
2356   return z;
2357 }
2358 
2359 #ifndef SQLITE_OMIT_UTF16
2360 /*
2361 ** Return UTF-16 encoded English language explanation of the most recent
2362 ** error.
2363 */
2364 const void *sqlite3_errmsg16(sqlite3 *db){
2365   static const u16 outOfMem[] = {
2366     'o', 'u', 't', ' ', 'o', 'f', ' ', 'm', 'e', 'm', 'o', 'r', 'y', 0
2367   };
2368   static const u16 misuse[] = {
2369     'b', 'a', 'd', ' ', 'p', 'a', 'r', 'a', 'm', 'e', 't', 'e', 'r', ' ',
2370     'o', 'r', ' ', 'o', 't', 'h', 'e', 'r', ' ', 'A', 'P', 'I', ' ',
2371     'm', 'i', 's', 'u', 's', 'e', 0
2372   };
2373 
2374   const void *z;
2375   if( !db ){
2376     return (void *)outOfMem;
2377   }
2378   if( !sqlite3SafetyCheckSickOrOk(db) ){
2379     return (void *)misuse;
2380   }
2381   sqlite3_mutex_enter(db->mutex);
2382   if( db->mallocFailed ){
2383     z = (void *)outOfMem;
2384   }else{
2385     z = sqlite3_value_text16(db->pErr);
2386     if( z==0 ){
2387       sqlite3ErrorWithMsg(db, db->errCode, sqlite3ErrStr(db->errCode));
2388       z = sqlite3_value_text16(db->pErr);
2389     }
2390     /* A malloc() may have failed within the call to sqlite3_value_text16()
2391     ** above. If this is the case, then the db->mallocFailed flag needs to
2392     ** be cleared before returning. Do this directly, instead of via
2393     ** sqlite3ApiExit(), to avoid setting the database handle error message.
2394     */
2395     sqlite3OomClear(db);
2396   }
2397   sqlite3_mutex_leave(db->mutex);
2398   return z;
2399 }
2400 #endif /* SQLITE_OMIT_UTF16 */
2401 
2402 /*
2403 ** Return the most recent error code generated by an SQLite routine. If NULL is
2404 ** passed to this function, we assume a malloc() failed during sqlite3_open().
2405 */
2406 int sqlite3_errcode(sqlite3 *db){
2407   if( db && !sqlite3SafetyCheckSickOrOk(db) ){
2408     return SQLITE_MISUSE_BKPT;
2409   }
2410   if( !db || db->mallocFailed ){
2411     return SQLITE_NOMEM_BKPT;
2412   }
2413   return db->errCode & db->errMask;
2414 }
2415 int sqlite3_extended_errcode(sqlite3 *db){
2416   if( db && !sqlite3SafetyCheckSickOrOk(db) ){
2417     return SQLITE_MISUSE_BKPT;
2418   }
2419   if( !db || db->mallocFailed ){
2420     return SQLITE_NOMEM_BKPT;
2421   }
2422   return db->errCode;
2423 }
2424 int sqlite3_system_errno(sqlite3 *db){
2425   return db ? db->iSysErrno : 0;
2426 }
2427 
2428 /*
2429 ** Return a string that describes the kind of error specified in the
2430 ** argument.  For now, this simply calls the internal sqlite3ErrStr()
2431 ** function.
2432 */
2433 const char *sqlite3_errstr(int rc){
2434   return sqlite3ErrStr(rc);
2435 }
2436 
2437 /*
2438 ** Create a new collating function for database "db".  The name is zName
2439 ** and the encoding is enc.
2440 */
2441 static int createCollation(
2442   sqlite3* db,
2443   const char *zName,
2444   u8 enc,
2445   void* pCtx,
2446   int(*xCompare)(void*,int,const void*,int,const void*),
2447   void(*xDel)(void*)
2448 ){
2449   CollSeq *pColl;
2450   int enc2;
2451 
2452   assert( sqlite3_mutex_held(db->mutex) );
2453 
2454   /* If SQLITE_UTF16 is specified as the encoding type, transform this
2455   ** to one of SQLITE_UTF16LE or SQLITE_UTF16BE using the
2456   ** SQLITE_UTF16NATIVE macro. SQLITE_UTF16 is not used internally.
2457   */
2458   enc2 = enc;
2459   testcase( enc2==SQLITE_UTF16 );
2460   testcase( enc2==SQLITE_UTF16_ALIGNED );
2461   if( enc2==SQLITE_UTF16 || enc2==SQLITE_UTF16_ALIGNED ){
2462     enc2 = SQLITE_UTF16NATIVE;
2463   }
2464   if( enc2<SQLITE_UTF8 || enc2>SQLITE_UTF16BE ){
2465     return SQLITE_MISUSE_BKPT;
2466   }
2467 
2468   /* Check if this call is removing or replacing an existing collation
2469   ** sequence. If so, and there are active VMs, return busy. If there
2470   ** are no active VMs, invalidate any pre-compiled statements.
2471   */
2472   pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, 0);
2473   if( pColl && pColl->xCmp ){
2474     if( db->nVdbeActive ){
2475       sqlite3ErrorWithMsg(db, SQLITE_BUSY,
2476         "unable to delete/modify collation sequence due to active statements");
2477       return SQLITE_BUSY;
2478     }
2479     sqlite3ExpirePreparedStatements(db);
2480 
2481     /* If collation sequence pColl was created directly by a call to
2482     ** sqlite3_create_collation, and not generated by synthCollSeq(),
2483     ** then any copies made by synthCollSeq() need to be invalidated.
2484     ** Also, collation destructor - CollSeq.xDel() - function may need
2485     ** to be called.
2486     */
2487     if( (pColl->enc & ~SQLITE_UTF16_ALIGNED)==enc2 ){
2488       CollSeq *aColl = sqlite3HashFind(&db->aCollSeq, zName);
2489       int j;
2490       for(j=0; j<3; j++){
2491         CollSeq *p = &aColl[j];
2492         if( p->enc==pColl->enc ){
2493           if( p->xDel ){
2494             p->xDel(p->pUser);
2495           }
2496           p->xCmp = 0;
2497         }
2498       }
2499     }
2500   }
2501 
2502   pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, 1);
2503   if( pColl==0 ) return SQLITE_NOMEM_BKPT;
2504   pColl->xCmp = xCompare;
2505   pColl->pUser = pCtx;
2506   pColl->xDel = xDel;
2507   pColl->enc = (u8)(enc2 | (enc & SQLITE_UTF16_ALIGNED));
2508   sqlite3Error(db, SQLITE_OK);
2509   return SQLITE_OK;
2510 }
2511 
2512 
2513 /*
2514 ** This array defines hard upper bounds on limit values.  The
2515 ** initializer must be kept in sync with the SQLITE_LIMIT_*
2516 ** #defines in sqlite3.h.
2517 */
2518 static const int aHardLimit[] = {
2519   SQLITE_MAX_LENGTH,
2520   SQLITE_MAX_SQL_LENGTH,
2521   SQLITE_MAX_COLUMN,
2522   SQLITE_MAX_EXPR_DEPTH,
2523   SQLITE_MAX_COMPOUND_SELECT,
2524   SQLITE_MAX_VDBE_OP,
2525   SQLITE_MAX_FUNCTION_ARG,
2526   SQLITE_MAX_ATTACHED,
2527   SQLITE_MAX_LIKE_PATTERN_LENGTH,
2528   SQLITE_MAX_VARIABLE_NUMBER,      /* IMP: R-38091-32352 */
2529   SQLITE_MAX_TRIGGER_DEPTH,
2530   SQLITE_MAX_WORKER_THREADS,
2531 };
2532 
2533 /*
2534 ** Make sure the hard limits are set to reasonable values
2535 */
2536 #if SQLITE_MAX_LENGTH<100
2537 # error SQLITE_MAX_LENGTH must be at least 100
2538 #endif
2539 #if SQLITE_MAX_SQL_LENGTH<100
2540 # error SQLITE_MAX_SQL_LENGTH must be at least 100
2541 #endif
2542 #if SQLITE_MAX_SQL_LENGTH>SQLITE_MAX_LENGTH
2543 # error SQLITE_MAX_SQL_LENGTH must not be greater than SQLITE_MAX_LENGTH
2544 #endif
2545 #if SQLITE_MAX_COMPOUND_SELECT<2
2546 # error SQLITE_MAX_COMPOUND_SELECT must be at least 2
2547 #endif
2548 #if SQLITE_MAX_VDBE_OP<40
2549 # error SQLITE_MAX_VDBE_OP must be at least 40
2550 #endif
2551 #if SQLITE_MAX_FUNCTION_ARG<0 || SQLITE_MAX_FUNCTION_ARG>127
2552 # error SQLITE_MAX_FUNCTION_ARG must be between 0 and 127
2553 #endif
2554 #if SQLITE_MAX_ATTACHED<0 || SQLITE_MAX_ATTACHED>125
2555 # error SQLITE_MAX_ATTACHED must be between 0 and 125
2556 #endif
2557 #if SQLITE_MAX_LIKE_PATTERN_LENGTH<1
2558 # error SQLITE_MAX_LIKE_PATTERN_LENGTH must be at least 1
2559 #endif
2560 #if SQLITE_MAX_COLUMN>32767
2561 # error SQLITE_MAX_COLUMN must not exceed 32767
2562 #endif
2563 #if SQLITE_MAX_TRIGGER_DEPTH<1
2564 # error SQLITE_MAX_TRIGGER_DEPTH must be at least 1
2565 #endif
2566 #if SQLITE_MAX_WORKER_THREADS<0 || SQLITE_MAX_WORKER_THREADS>50
2567 # error SQLITE_MAX_WORKER_THREADS must be between 0 and 50
2568 #endif
2569 
2570 
2571 /*
2572 ** Change the value of a limit.  Report the old value.
2573 ** If an invalid limit index is supplied, report -1.
2574 ** Make no changes but still report the old value if the
2575 ** new limit is negative.
2576 **
2577 ** A new lower limit does not shrink existing constructs.
2578 ** It merely prevents new constructs that exceed the limit
2579 ** from forming.
2580 */
2581 int sqlite3_limit(sqlite3 *db, int limitId, int newLimit){
2582   int oldLimit;
2583 
2584 #ifdef SQLITE_ENABLE_API_ARMOR
2585   if( !sqlite3SafetyCheckOk(db) ){
2586     (void)SQLITE_MISUSE_BKPT;
2587     return -1;
2588   }
2589 #endif
2590 
2591   /* EVIDENCE-OF: R-30189-54097 For each limit category SQLITE_LIMIT_NAME
2592   ** there is a hard upper bound set at compile-time by a C preprocessor
2593   ** macro called SQLITE_MAX_NAME. (The "_LIMIT_" in the name is changed to
2594   ** "_MAX_".)
2595   */
2596   assert( aHardLimit[SQLITE_LIMIT_LENGTH]==SQLITE_MAX_LENGTH );
2597   assert( aHardLimit[SQLITE_LIMIT_SQL_LENGTH]==SQLITE_MAX_SQL_LENGTH );
2598   assert( aHardLimit[SQLITE_LIMIT_COLUMN]==SQLITE_MAX_COLUMN );
2599   assert( aHardLimit[SQLITE_LIMIT_EXPR_DEPTH]==SQLITE_MAX_EXPR_DEPTH );
2600   assert( aHardLimit[SQLITE_LIMIT_COMPOUND_SELECT]==SQLITE_MAX_COMPOUND_SELECT);
2601   assert( aHardLimit[SQLITE_LIMIT_VDBE_OP]==SQLITE_MAX_VDBE_OP );
2602   assert( aHardLimit[SQLITE_LIMIT_FUNCTION_ARG]==SQLITE_MAX_FUNCTION_ARG );
2603   assert( aHardLimit[SQLITE_LIMIT_ATTACHED]==SQLITE_MAX_ATTACHED );
2604   assert( aHardLimit[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]==
2605                                                SQLITE_MAX_LIKE_PATTERN_LENGTH );
2606   assert( aHardLimit[SQLITE_LIMIT_VARIABLE_NUMBER]==SQLITE_MAX_VARIABLE_NUMBER);
2607   assert( aHardLimit[SQLITE_LIMIT_TRIGGER_DEPTH]==SQLITE_MAX_TRIGGER_DEPTH );
2608   assert( aHardLimit[SQLITE_LIMIT_WORKER_THREADS]==SQLITE_MAX_WORKER_THREADS );
2609   assert( SQLITE_LIMIT_WORKER_THREADS==(SQLITE_N_LIMIT-1) );
2610 
2611 
2612   if( limitId<0 || limitId>=SQLITE_N_LIMIT ){
2613     return -1;
2614   }
2615   oldLimit = db->aLimit[limitId];
2616   if( newLimit>=0 ){                   /* IMP: R-52476-28732 */
2617     if( newLimit>aHardLimit[limitId] ){
2618       newLimit = aHardLimit[limitId];  /* IMP: R-51463-25634 */
2619     }
2620     db->aLimit[limitId] = newLimit;
2621   }
2622   return oldLimit;                     /* IMP: R-53341-35419 */
2623 }
2624 
2625 /*
2626 ** This function is used to parse both URIs and non-URI filenames passed by the
2627 ** user to API functions sqlite3_open() or sqlite3_open_v2(), and for database
2628 ** URIs specified as part of ATTACH statements.
2629 **
2630 ** The first argument to this function is the name of the VFS to use (or
2631 ** a NULL to signify the default VFS) if the URI does not contain a "vfs=xxx"
2632 ** query parameter. The second argument contains the URI (or non-URI filename)
2633 ** itself. When this function is called the *pFlags variable should contain
2634 ** the default flags to open the database handle with. The value stored in
2635 ** *pFlags may be updated before returning if the URI filename contains
2636 ** "cache=xxx" or "mode=xxx" query parameters.
2637 **
2638 ** If successful, SQLITE_OK is returned. In this case *ppVfs is set to point to
2639 ** the VFS that should be used to open the database file. *pzFile is set to
2640 ** point to a buffer containing the name of the file to open. It is the
2641 ** responsibility of the caller to eventually call sqlite3_free() to release
2642 ** this buffer.
2643 **
2644 ** If an error occurs, then an SQLite error code is returned and *pzErrMsg
2645 ** may be set to point to a buffer containing an English language error
2646 ** message. It is the responsibility of the caller to eventually release
2647 ** this buffer by calling sqlite3_free().
2648 */
2649 int sqlite3ParseUri(
2650   const char *zDefaultVfs,        /* VFS to use if no "vfs=xxx" query option */
2651   const char *zUri,               /* Nul-terminated URI to parse */
2652   unsigned int *pFlags,           /* IN/OUT: SQLITE_OPEN_XXX flags */
2653   sqlite3_vfs **ppVfs,            /* OUT: VFS to use */
2654   char **pzFile,                  /* OUT: Filename component of URI */
2655   char **pzErrMsg                 /* OUT: Error message (if rc!=SQLITE_OK) */
2656 ){
2657   int rc = SQLITE_OK;
2658   unsigned int flags = *pFlags;
2659   const char *zVfs = zDefaultVfs;
2660   char *zFile;
2661   char c;
2662   int nUri = sqlite3Strlen30(zUri);
2663 
2664   assert( *pzErrMsg==0 );
2665 
2666   if( ((flags & SQLITE_OPEN_URI)             /* IMP: R-48725-32206 */
2667             || sqlite3GlobalConfig.bOpenUri) /* IMP: R-51689-46548 */
2668    && nUri>=5 && memcmp(zUri, "file:", 5)==0 /* IMP: R-57884-37496 */
2669   ){
2670     char *zOpt;
2671     int eState;                   /* Parser state when parsing URI */
2672     int iIn;                      /* Input character index */
2673     int iOut = 0;                 /* Output character index */
2674     u64 nByte = nUri+2;           /* Bytes of space to allocate */
2675 
2676     /* Make sure the SQLITE_OPEN_URI flag is set to indicate to the VFS xOpen
2677     ** method that there may be extra parameters following the file-name.  */
2678     flags |= SQLITE_OPEN_URI;
2679 
2680     for(iIn=0; iIn<nUri; iIn++) nByte += (zUri[iIn]=='&');
2681     zFile = sqlite3_malloc64(nByte);
2682     if( !zFile ) return SQLITE_NOMEM_BKPT;
2683 
2684     iIn = 5;
2685 #ifdef SQLITE_ALLOW_URI_AUTHORITY
2686     if( strncmp(zUri+5, "///", 3)==0 ){
2687       iIn = 7;
2688       /* The following condition causes URIs with five leading / characters
2689       ** like file://///host/path to be converted into UNCs like //host/path.
2690       ** The correct URI for that UNC has only two or four leading / characters
2691       ** file://host/path or file:////host/path.  But 5 leading slashes is a
2692       ** common error, we are told, so we handle it as a special case. */
2693       if( strncmp(zUri+7, "///", 3)==0 ){ iIn++; }
2694     }else if( strncmp(zUri+5, "//localhost/", 12)==0 ){
2695       iIn = 16;
2696     }
2697 #else
2698     /* Discard the scheme and authority segments of the URI. */
2699     if( zUri[5]=='/' && zUri[6]=='/' ){
2700       iIn = 7;
2701       while( zUri[iIn] && zUri[iIn]!='/' ) iIn++;
2702       if( iIn!=7 && (iIn!=16 || memcmp("localhost", &zUri[7], 9)) ){
2703         *pzErrMsg = sqlite3_mprintf("invalid uri authority: %.*s",
2704             iIn-7, &zUri[7]);
2705         rc = SQLITE_ERROR;
2706         goto parse_uri_out;
2707       }
2708     }
2709 #endif
2710 
2711     /* Copy the filename and any query parameters into the zFile buffer.
2712     ** Decode %HH escape codes along the way.
2713     **
2714     ** Within this loop, variable eState may be set to 0, 1 or 2, depending
2715     ** on the parsing context. As follows:
2716     **
2717     **   0: Parsing file-name.
2718     **   1: Parsing name section of a name=value query parameter.
2719     **   2: Parsing value section of a name=value query parameter.
2720     */
2721     eState = 0;
2722     while( (c = zUri[iIn])!=0 && c!='#' ){
2723       iIn++;
2724       if( c=='%'
2725        && sqlite3Isxdigit(zUri[iIn])
2726        && sqlite3Isxdigit(zUri[iIn+1])
2727       ){
2728         int octet = (sqlite3HexToInt(zUri[iIn++]) << 4);
2729         octet += sqlite3HexToInt(zUri[iIn++]);
2730 
2731         assert( octet>=0 && octet<256 );
2732         if( octet==0 ){
2733 #ifndef SQLITE_ENABLE_URI_00_ERROR
2734           /* This branch is taken when "%00" appears within the URI. In this
2735           ** case we ignore all text in the remainder of the path, name or
2736           ** value currently being parsed. So ignore the current character
2737           ** and skip to the next "?", "=" or "&", as appropriate. */
2738           while( (c = zUri[iIn])!=0 && c!='#'
2739               && (eState!=0 || c!='?')
2740               && (eState!=1 || (c!='=' && c!='&'))
2741               && (eState!=2 || c!='&')
2742           ){
2743             iIn++;
2744           }
2745           continue;
2746 #else
2747           /* If ENABLE_URI_00_ERROR is defined, "%00" in a URI is an error. */
2748           *pzErrMsg = sqlite3_mprintf("unexpected %%00 in uri");
2749           rc = SQLITE_ERROR;
2750           goto parse_uri_out;
2751 #endif
2752         }
2753         c = octet;
2754       }else if( eState==1 && (c=='&' || c=='=') ){
2755         if( zFile[iOut-1]==0 ){
2756           /* An empty option name. Ignore this option altogether. */
2757           while( zUri[iIn] && zUri[iIn]!='#' && zUri[iIn-1]!='&' ) iIn++;
2758           continue;
2759         }
2760         if( c=='&' ){
2761           zFile[iOut++] = '\0';
2762         }else{
2763           eState = 2;
2764         }
2765         c = 0;
2766       }else if( (eState==0 && c=='?') || (eState==2 && c=='&') ){
2767         c = 0;
2768         eState = 1;
2769       }
2770       zFile[iOut++] = c;
2771     }
2772     if( eState==1 ) zFile[iOut++] = '\0';
2773     zFile[iOut++] = '\0';
2774     zFile[iOut++] = '\0';
2775 
2776     /* Check if there were any options specified that should be interpreted
2777     ** here. Options that are interpreted here include "vfs" and those that
2778     ** correspond to flags that may be passed to the sqlite3_open_v2()
2779     ** method. */
2780     zOpt = &zFile[sqlite3Strlen30(zFile)+1];
2781     while( zOpt[0] ){
2782       int nOpt = sqlite3Strlen30(zOpt);
2783       char *zVal = &zOpt[nOpt+1];
2784       int nVal = sqlite3Strlen30(zVal);
2785 
2786       if( nOpt==3 && memcmp("vfs", zOpt, 3)==0 ){
2787         zVfs = zVal;
2788       }else{
2789         struct OpenMode {
2790           const char *z;
2791           int mode;
2792         } *aMode = 0;
2793         char *zModeType = 0;
2794         int mask = 0;
2795         int limit = 0;
2796 
2797         if( nOpt==5 && memcmp("cache", zOpt, 5)==0 ){
2798           static struct OpenMode aCacheMode[] = {
2799             { "shared",  SQLITE_OPEN_SHAREDCACHE },
2800             { "private", SQLITE_OPEN_PRIVATECACHE },
2801             { 0, 0 }
2802           };
2803 
2804           mask = SQLITE_OPEN_SHAREDCACHE|SQLITE_OPEN_PRIVATECACHE;
2805           aMode = aCacheMode;
2806           limit = mask;
2807           zModeType = "cache";
2808         }
2809         if( nOpt==4 && memcmp("mode", zOpt, 4)==0 ){
2810           static struct OpenMode aOpenMode[] = {
2811             { "ro",  SQLITE_OPEN_READONLY },
2812             { "rw",  SQLITE_OPEN_READWRITE },
2813             { "rwc", SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE },
2814             { "memory", SQLITE_OPEN_MEMORY },
2815             { 0, 0 }
2816           };
2817 
2818           mask = SQLITE_OPEN_READONLY | SQLITE_OPEN_READWRITE
2819                    | SQLITE_OPEN_CREATE | SQLITE_OPEN_MEMORY;
2820           aMode = aOpenMode;
2821           limit = mask & flags;
2822           zModeType = "access";
2823         }
2824 
2825         if( aMode ){
2826           int i;
2827           int mode = 0;
2828           for(i=0; aMode[i].z; i++){
2829             const char *z = aMode[i].z;
2830             if( nVal==sqlite3Strlen30(z) && 0==memcmp(zVal, z, nVal) ){
2831               mode = aMode[i].mode;
2832               break;
2833             }
2834           }
2835           if( mode==0 ){
2836             *pzErrMsg = sqlite3_mprintf("no such %s mode: %s", zModeType, zVal);
2837             rc = SQLITE_ERROR;
2838             goto parse_uri_out;
2839           }
2840           if( (mode & ~SQLITE_OPEN_MEMORY)>limit ){
2841             *pzErrMsg = sqlite3_mprintf("%s mode not allowed: %s",
2842                                         zModeType, zVal);
2843             rc = SQLITE_PERM;
2844             goto parse_uri_out;
2845           }
2846           flags = (flags & ~mask) | mode;
2847         }
2848       }
2849 
2850       zOpt = &zVal[nVal+1];
2851     }
2852 
2853   }else{
2854     zFile = sqlite3_malloc64(nUri+2);
2855     if( !zFile ) return SQLITE_NOMEM_BKPT;
2856     if( nUri ){
2857       memcpy(zFile, zUri, nUri);
2858     }
2859     zFile[nUri] = '\0';
2860     zFile[nUri+1] = '\0';
2861     flags &= ~SQLITE_OPEN_URI;
2862   }
2863 
2864   *ppVfs = sqlite3_vfs_find(zVfs);
2865   if( *ppVfs==0 ){
2866     *pzErrMsg = sqlite3_mprintf("no such vfs: %s", zVfs);
2867     rc = SQLITE_ERROR;
2868   }
2869  parse_uri_out:
2870   if( rc!=SQLITE_OK ){
2871     sqlite3_free(zFile);
2872     zFile = 0;
2873   }
2874   *pFlags = flags;
2875   *pzFile = zFile;
2876   return rc;
2877 }
2878 
2879 
2880 /*
2881 ** This routine does the work of opening a database on behalf of
2882 ** sqlite3_open() and sqlite3_open16(). The database filename "zFilename"
2883 ** is UTF-8 encoded.
2884 */
2885 static int openDatabase(
2886   const char *zFilename, /* Database filename UTF-8 encoded */
2887   sqlite3 **ppDb,        /* OUT: Returned database handle */
2888   unsigned int flags,    /* Operational flags */
2889   const char *zVfs       /* Name of the VFS to use */
2890 ){
2891   sqlite3 *db;                    /* Store allocated handle here */
2892   int rc;                         /* Return code */
2893   int isThreadsafe;               /* True for threadsafe connections */
2894   char *zOpen = 0;                /* Filename argument to pass to BtreeOpen() */
2895   char *zErrMsg = 0;              /* Error message from sqlite3ParseUri() */
2896 
2897 #ifdef SQLITE_ENABLE_API_ARMOR
2898   if( ppDb==0 ) return SQLITE_MISUSE_BKPT;
2899 #endif
2900   *ppDb = 0;
2901 #ifndef SQLITE_OMIT_AUTOINIT
2902   rc = sqlite3_initialize();
2903   if( rc ) return rc;
2904 #endif
2905 
2906   if( sqlite3GlobalConfig.bCoreMutex==0 ){
2907     isThreadsafe = 0;
2908   }else if( flags & SQLITE_OPEN_NOMUTEX ){
2909     isThreadsafe = 0;
2910   }else if( flags & SQLITE_OPEN_FULLMUTEX ){
2911     isThreadsafe = 1;
2912   }else{
2913     isThreadsafe = sqlite3GlobalConfig.bFullMutex;
2914   }
2915 
2916   if( flags & SQLITE_OPEN_PRIVATECACHE ){
2917     flags &= ~SQLITE_OPEN_SHAREDCACHE;
2918   }else if( sqlite3GlobalConfig.sharedCacheEnabled ){
2919     flags |= SQLITE_OPEN_SHAREDCACHE;
2920   }
2921 
2922   /* Remove harmful bits from the flags parameter
2923   **
2924   ** The SQLITE_OPEN_NOMUTEX and SQLITE_OPEN_FULLMUTEX flags were
2925   ** dealt with in the previous code block.  Besides these, the only
2926   ** valid input flags for sqlite3_open_v2() are SQLITE_OPEN_READONLY,
2927   ** SQLITE_OPEN_READWRITE, SQLITE_OPEN_CREATE, SQLITE_OPEN_SHAREDCACHE,
2928   ** SQLITE_OPEN_PRIVATECACHE, and some reserved bits.  Silently mask
2929   ** off all other flags.
2930   */
2931   flags &=  ~( SQLITE_OPEN_DELETEONCLOSE |
2932                SQLITE_OPEN_EXCLUSIVE |
2933                SQLITE_OPEN_MAIN_DB |
2934                SQLITE_OPEN_TEMP_DB |
2935                SQLITE_OPEN_TRANSIENT_DB |
2936                SQLITE_OPEN_MAIN_JOURNAL |
2937                SQLITE_OPEN_TEMP_JOURNAL |
2938                SQLITE_OPEN_SUBJOURNAL |
2939                SQLITE_OPEN_MASTER_JOURNAL |
2940                SQLITE_OPEN_NOMUTEX |
2941                SQLITE_OPEN_FULLMUTEX |
2942                SQLITE_OPEN_WAL
2943              );
2944 
2945   /* Allocate the sqlite data structure */
2946   db = sqlite3MallocZero( sizeof(sqlite3) );
2947   if( db==0 ) goto opendb_out;
2948   if( isThreadsafe
2949 #ifdef SQLITE_ENABLE_MULTITHREADED_CHECKS
2950    || sqlite3GlobalConfig.bCoreMutex
2951 #endif
2952   ){
2953     db->mutex = sqlite3MutexAlloc(SQLITE_MUTEX_RECURSIVE);
2954     if( db->mutex==0 ){
2955       sqlite3_free(db);
2956       db = 0;
2957       goto opendb_out;
2958     }
2959     if( isThreadsafe==0 ){
2960       sqlite3MutexWarnOnContention(db->mutex);
2961     }
2962   }
2963   sqlite3_mutex_enter(db->mutex);
2964   db->errMask = 0xff;
2965   db->nDb = 2;
2966   db->magic = SQLITE_MAGIC_BUSY;
2967   db->aDb = db->aDbStatic;
2968 
2969   assert( sizeof(db->aLimit)==sizeof(aHardLimit) );
2970   memcpy(db->aLimit, aHardLimit, sizeof(db->aLimit));
2971   db->aLimit[SQLITE_LIMIT_WORKER_THREADS] = SQLITE_DEFAULT_WORKER_THREADS;
2972   db->autoCommit = 1;
2973   db->nextAutovac = -1;
2974   db->szMmap = sqlite3GlobalConfig.szMmap;
2975   db->nextPagesize = 0;
2976   db->nMaxSorterMmap = 0x7FFFFFFF;
2977   db->flags |= SQLITE_ShortColNames | SQLITE_EnableTrigger | SQLITE_CacheSpill
2978 #if !defined(SQLITE_DEFAULT_AUTOMATIC_INDEX) || SQLITE_DEFAULT_AUTOMATIC_INDEX
2979                  | SQLITE_AutoIndex
2980 #endif
2981 #if SQLITE_DEFAULT_CKPTFULLFSYNC
2982                  | SQLITE_CkptFullFSync
2983 #endif
2984 #if SQLITE_DEFAULT_FILE_FORMAT<4
2985                  | SQLITE_LegacyFileFmt
2986 #endif
2987 #ifdef SQLITE_ENABLE_LOAD_EXTENSION
2988                  | SQLITE_LoadExtension
2989 #endif
2990 #if SQLITE_DEFAULT_RECURSIVE_TRIGGERS
2991                  | SQLITE_RecTriggers
2992 #endif
2993 #if defined(SQLITE_DEFAULT_FOREIGN_KEYS) && SQLITE_DEFAULT_FOREIGN_KEYS
2994                  | SQLITE_ForeignKeys
2995 #endif
2996 #if defined(SQLITE_REVERSE_UNORDERED_SELECTS)
2997                  | SQLITE_ReverseOrder
2998 #endif
2999 #if defined(SQLITE_ENABLE_OVERSIZE_CELL_CHECK)
3000                  | SQLITE_CellSizeCk
3001 #endif
3002 #if defined(SQLITE_ENABLE_FTS3_TOKENIZER)
3003                  | SQLITE_Fts3Tokenizer
3004 #endif
3005 #if defined(SQLITE_ENABLE_QPSG)
3006                  | SQLITE_EnableQPSG
3007 #endif
3008       ;
3009   sqlite3HashInit(&db->aCollSeq);
3010 #ifndef SQLITE_OMIT_VIRTUALTABLE
3011   sqlite3HashInit(&db->aModule);
3012 #endif
3013 
3014   /* Add the default collation sequence BINARY. BINARY works for both UTF-8
3015   ** and UTF-16, so add a version for each to avoid any unnecessary
3016   ** conversions. The only error that can occur here is a malloc() failure.
3017   **
3018   ** EVIDENCE-OF: R-52786-44878 SQLite defines three built-in collating
3019   ** functions:
3020   */
3021   createCollation(db, sqlite3StrBINARY, SQLITE_UTF8, 0, binCollFunc, 0);
3022   createCollation(db, sqlite3StrBINARY, SQLITE_UTF16BE, 0, binCollFunc, 0);
3023   createCollation(db, sqlite3StrBINARY, SQLITE_UTF16LE, 0, binCollFunc, 0);
3024   createCollation(db, "NOCASE", SQLITE_UTF8, 0, nocaseCollatingFunc, 0);
3025   createCollation(db, "RTRIM", SQLITE_UTF8, (void*)1, binCollFunc, 0);
3026   if( db->mallocFailed ){
3027     goto opendb_out;
3028   }
3029   /* EVIDENCE-OF: R-08308-17224 The default collating function for all
3030   ** strings is BINARY.
3031   */
3032   db->pDfltColl = sqlite3FindCollSeq(db, SQLITE_UTF8, sqlite3StrBINARY, 0);
3033   assert( db->pDfltColl!=0 );
3034 
3035   /* Parse the filename/URI argument
3036   **
3037   ** Only allow sensible combinations of bits in the flags argument.
3038   ** Throw an error if any non-sense combination is used.  If we
3039   ** do not block illegal combinations here, it could trigger
3040   ** assert() statements in deeper layers.  Sensible combinations
3041   ** are:
3042   **
3043   **  1:  SQLITE_OPEN_READONLY
3044   **  2:  SQLITE_OPEN_READWRITE
3045   **  6:  SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE
3046   */
3047   db->openFlags = flags;
3048   assert( SQLITE_OPEN_READONLY  == 0x01 );
3049   assert( SQLITE_OPEN_READWRITE == 0x02 );
3050   assert( SQLITE_OPEN_CREATE    == 0x04 );
3051   testcase( (1<<(flags&7))==0x02 ); /* READONLY */
3052   testcase( (1<<(flags&7))==0x04 ); /* READWRITE */
3053   testcase( (1<<(flags&7))==0x40 ); /* READWRITE | CREATE */
3054   if( ((1<<(flags&7)) & 0x46)==0 ){
3055     rc = SQLITE_MISUSE_BKPT;  /* IMP: R-65497-44594 */
3056   }else{
3057     rc = sqlite3ParseUri(zVfs, zFilename, &flags, &db->pVfs, &zOpen, &zErrMsg);
3058   }
3059   if( rc!=SQLITE_OK ){
3060     if( rc==SQLITE_NOMEM ) sqlite3OomFault(db);
3061     sqlite3ErrorWithMsg(db, rc, zErrMsg ? "%s" : 0, zErrMsg);
3062     sqlite3_free(zErrMsg);
3063     goto opendb_out;
3064   }
3065 
3066   /* Open the backend database driver */
3067   rc = sqlite3BtreeOpen(db->pVfs, zOpen, db, &db->aDb[0].pBt, 0,
3068                         flags | SQLITE_OPEN_MAIN_DB);
3069   if( rc!=SQLITE_OK ){
3070     if( rc==SQLITE_IOERR_NOMEM ){
3071       rc = SQLITE_NOMEM_BKPT;
3072     }
3073     sqlite3Error(db, rc);
3074     goto opendb_out;
3075   }
3076   sqlite3BtreeEnter(db->aDb[0].pBt);
3077   db->aDb[0].pSchema = sqlite3SchemaGet(db, db->aDb[0].pBt);
3078   if( !db->mallocFailed ) ENC(db) = SCHEMA_ENC(db);
3079   sqlite3BtreeLeave(db->aDb[0].pBt);
3080   db->aDb[1].pSchema = sqlite3SchemaGet(db, 0);
3081 
3082   /* The default safety_level for the main database is FULL; for the temp
3083   ** database it is OFF. This matches the pager layer defaults.
3084   */
3085   db->aDb[0].zDbSName = "main";
3086   db->aDb[0].safety_level = SQLITE_DEFAULT_SYNCHRONOUS+1;
3087   db->aDb[1].zDbSName = "temp";
3088   db->aDb[1].safety_level = PAGER_SYNCHRONOUS_OFF;
3089 
3090   db->magic = SQLITE_MAGIC_OPEN;
3091   if( db->mallocFailed ){
3092     goto opendb_out;
3093   }
3094 
3095   /* Register all built-in functions, but do not attempt to read the
3096   ** database schema yet. This is delayed until the first time the database
3097   ** is accessed.
3098   */
3099   sqlite3Error(db, SQLITE_OK);
3100   sqlite3RegisterPerConnectionBuiltinFunctions(db);
3101   rc = sqlite3_errcode(db);
3102 
3103 #ifdef SQLITE_ENABLE_FTS5
3104   /* Register any built-in FTS5 module before loading the automatic
3105   ** extensions. This allows automatic extensions to register FTS5
3106   ** tokenizers and auxiliary functions.  */
3107   if( !db->mallocFailed && rc==SQLITE_OK ){
3108     rc = sqlite3Fts5Init(db);
3109   }
3110 #endif
3111 
3112   /* Load automatic extensions - extensions that have been registered
3113   ** using the sqlite3_automatic_extension() API.
3114   */
3115   if( rc==SQLITE_OK ){
3116     sqlite3AutoLoadExtensions(db);
3117     rc = sqlite3_errcode(db);
3118     if( rc!=SQLITE_OK ){
3119       goto opendb_out;
3120     }
3121   }
3122 
3123 #ifdef SQLITE_ENABLE_FTS1
3124   if( !db->mallocFailed ){
3125     extern int sqlite3Fts1Init(sqlite3*);
3126     rc = sqlite3Fts1Init(db);
3127   }
3128 #endif
3129 
3130 #ifdef SQLITE_ENABLE_FTS2
3131   if( !db->mallocFailed && rc==SQLITE_OK ){
3132     extern int sqlite3Fts2Init(sqlite3*);
3133     rc = sqlite3Fts2Init(db);
3134   }
3135 #endif
3136 
3137 #ifdef SQLITE_ENABLE_FTS3 /* automatically defined by SQLITE_ENABLE_FTS4 */
3138   if( !db->mallocFailed && rc==SQLITE_OK ){
3139     rc = sqlite3Fts3Init(db);
3140   }
3141 #endif
3142 
3143 #if defined(SQLITE_ENABLE_ICU) || defined(SQLITE_ENABLE_ICU_COLLATIONS)
3144   if( !db->mallocFailed && rc==SQLITE_OK ){
3145     rc = sqlite3IcuInit(db);
3146   }
3147 #endif
3148 
3149 #ifdef SQLITE_ENABLE_RTREE
3150   if( !db->mallocFailed && rc==SQLITE_OK){
3151     rc = sqlite3RtreeInit(db);
3152   }
3153 #endif
3154 
3155 #ifdef SQLITE_ENABLE_DBPAGE_VTAB
3156   if( !db->mallocFailed && rc==SQLITE_OK){
3157     rc = sqlite3DbpageRegister(db);
3158   }
3159 #endif
3160 
3161 #ifdef SQLITE_ENABLE_DBSTAT_VTAB
3162   if( !db->mallocFailed && rc==SQLITE_OK){
3163     rc = sqlite3DbstatRegister(db);
3164   }
3165 #endif
3166 
3167 #ifdef SQLITE_ENABLE_JSON1
3168   if( !db->mallocFailed && rc==SQLITE_OK){
3169     rc = sqlite3Json1Init(db);
3170   }
3171 #endif
3172 
3173 #ifdef SQLITE_ENABLE_STMTVTAB
3174   if( !db->mallocFailed && rc==SQLITE_OK){
3175     rc = sqlite3StmtVtabInit(db);
3176   }
3177 #endif
3178 
3179   /* -DSQLITE_DEFAULT_LOCKING_MODE=1 makes EXCLUSIVE the default locking
3180   ** mode.  -DSQLITE_DEFAULT_LOCKING_MODE=0 make NORMAL the default locking
3181   ** mode.  Doing nothing at all also makes NORMAL the default.
3182   */
3183 #ifdef SQLITE_DEFAULT_LOCKING_MODE
3184   db->dfltLockMode = SQLITE_DEFAULT_LOCKING_MODE;
3185   sqlite3PagerLockingMode(sqlite3BtreePager(db->aDb[0].pBt),
3186                           SQLITE_DEFAULT_LOCKING_MODE);
3187 #endif
3188 
3189   if( rc ) sqlite3Error(db, rc);
3190 
3191   /* Enable the lookaside-malloc subsystem */
3192   setupLookaside(db, 0, sqlite3GlobalConfig.szLookaside,
3193                         sqlite3GlobalConfig.nLookaside);
3194 
3195   sqlite3_wal_autocheckpoint(db, SQLITE_DEFAULT_WAL_AUTOCHECKPOINT);
3196 
3197 opendb_out:
3198   if( db ){
3199     assert( db->mutex!=0 || isThreadsafe==0
3200            || sqlite3GlobalConfig.bFullMutex==0 );
3201     sqlite3_mutex_leave(db->mutex);
3202   }
3203   rc = sqlite3_errcode(db);
3204   assert( db!=0 || rc==SQLITE_NOMEM );
3205   if( rc==SQLITE_NOMEM ){
3206     sqlite3_close(db);
3207     db = 0;
3208   }else if( rc!=SQLITE_OK ){
3209     db->magic = SQLITE_MAGIC_SICK;
3210   }
3211   *ppDb = db;
3212 #ifdef SQLITE_ENABLE_SQLLOG
3213   if( sqlite3GlobalConfig.xSqllog ){
3214     /* Opening a db handle. Fourth parameter is passed 0. */
3215     void *pArg = sqlite3GlobalConfig.pSqllogArg;
3216     sqlite3GlobalConfig.xSqllog(pArg, db, zFilename, 0);
3217   }
3218 #endif
3219 #if defined(SQLITE_HAS_CODEC)
3220   if( rc==SQLITE_OK ){
3221     const char *zKey;
3222     if( (zKey = sqlite3_uri_parameter(zOpen, "hexkey"))!=0 && zKey[0] ){
3223       u8 iByte;
3224       int i;
3225       char zDecoded[40];
3226       for(i=0, iByte=0; i<sizeof(zDecoded)*2 && sqlite3Isxdigit(zKey[i]); i++){
3227         iByte = (iByte<<4) + sqlite3HexToInt(zKey[i]);
3228         if( (i&1)!=0 ) zDecoded[i/2] = iByte;
3229       }
3230       sqlite3_key_v2(db, 0, zDecoded, i/2);
3231     }else if( (zKey = sqlite3_uri_parameter(zOpen, "key"))!=0 ){
3232       sqlite3_key_v2(db, 0, zKey, sqlite3Strlen30(zKey));
3233     }
3234   }
3235 #endif
3236   sqlite3_free(zOpen);
3237   return rc & 0xff;
3238 }
3239 
3240 /*
3241 ** Open a new database handle.
3242 */
3243 int sqlite3_open(
3244   const char *zFilename,
3245   sqlite3 **ppDb
3246 ){
3247   return openDatabase(zFilename, ppDb,
3248                       SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
3249 }
3250 int sqlite3_open_v2(
3251   const char *filename,   /* Database filename (UTF-8) */
3252   sqlite3 **ppDb,         /* OUT: SQLite db handle */
3253   int flags,              /* Flags */
3254   const char *zVfs        /* Name of VFS module to use */
3255 ){
3256   return openDatabase(filename, ppDb, (unsigned int)flags, zVfs);
3257 }
3258 
3259 #ifndef SQLITE_OMIT_UTF16
3260 /*
3261 ** Open a new database handle.
3262 */
3263 int sqlite3_open16(
3264   const void *zFilename,
3265   sqlite3 **ppDb
3266 ){
3267   char const *zFilename8;   /* zFilename encoded in UTF-8 instead of UTF-16 */
3268   sqlite3_value *pVal;
3269   int rc;
3270 
3271 #ifdef SQLITE_ENABLE_API_ARMOR
3272   if( ppDb==0 ) return SQLITE_MISUSE_BKPT;
3273 #endif
3274   *ppDb = 0;
3275 #ifndef SQLITE_OMIT_AUTOINIT
3276   rc = sqlite3_initialize();
3277   if( rc ) return rc;
3278 #endif
3279   if( zFilename==0 ) zFilename = "\000\000";
3280   pVal = sqlite3ValueNew(0);
3281   sqlite3ValueSetStr(pVal, -1, zFilename, SQLITE_UTF16NATIVE, SQLITE_STATIC);
3282   zFilename8 = sqlite3ValueText(pVal, SQLITE_UTF8);
3283   if( zFilename8 ){
3284     rc = openDatabase(zFilename8, ppDb,
3285                       SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
3286     assert( *ppDb || rc==SQLITE_NOMEM );
3287     if( rc==SQLITE_OK && !DbHasProperty(*ppDb, 0, DB_SchemaLoaded) ){
3288       SCHEMA_ENC(*ppDb) = ENC(*ppDb) = SQLITE_UTF16NATIVE;
3289     }
3290   }else{
3291     rc = SQLITE_NOMEM_BKPT;
3292   }
3293   sqlite3ValueFree(pVal);
3294 
3295   return rc & 0xff;
3296 }
3297 #endif /* SQLITE_OMIT_UTF16 */
3298 
3299 /*
3300 ** Register a new collation sequence with the database handle db.
3301 */
3302 int sqlite3_create_collation(
3303   sqlite3* db,
3304   const char *zName,
3305   int enc,
3306   void* pCtx,
3307   int(*xCompare)(void*,int,const void*,int,const void*)
3308 ){
3309   return sqlite3_create_collation_v2(db, zName, enc, pCtx, xCompare, 0);
3310 }
3311 
3312 /*
3313 ** Register a new collation sequence with the database handle db.
3314 */
3315 int sqlite3_create_collation_v2(
3316   sqlite3* db,
3317   const char *zName,
3318   int enc,
3319   void* pCtx,
3320   int(*xCompare)(void*,int,const void*,int,const void*),
3321   void(*xDel)(void*)
3322 ){
3323   int rc;
3324 
3325 #ifdef SQLITE_ENABLE_API_ARMOR
3326   if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
3327 #endif
3328   sqlite3_mutex_enter(db->mutex);
3329   assert( !db->mallocFailed );
3330   rc = createCollation(db, zName, (u8)enc, pCtx, xCompare, xDel);
3331   rc = sqlite3ApiExit(db, rc);
3332   sqlite3_mutex_leave(db->mutex);
3333   return rc;
3334 }
3335 
3336 #ifndef SQLITE_OMIT_UTF16
3337 /*
3338 ** Register a new collation sequence with the database handle db.
3339 */
3340 int sqlite3_create_collation16(
3341   sqlite3* db,
3342   const void *zName,
3343   int enc,
3344   void* pCtx,
3345   int(*xCompare)(void*,int,const void*,int,const void*)
3346 ){
3347   int rc = SQLITE_OK;
3348   char *zName8;
3349 
3350 #ifdef SQLITE_ENABLE_API_ARMOR
3351   if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
3352 #endif
3353   sqlite3_mutex_enter(db->mutex);
3354   assert( !db->mallocFailed );
3355   zName8 = sqlite3Utf16to8(db, zName, -1, SQLITE_UTF16NATIVE);
3356   if( zName8 ){
3357     rc = createCollation(db, zName8, (u8)enc, pCtx, xCompare, 0);
3358     sqlite3DbFree(db, zName8);
3359   }
3360   rc = sqlite3ApiExit(db, rc);
3361   sqlite3_mutex_leave(db->mutex);
3362   return rc;
3363 }
3364 #endif /* SQLITE_OMIT_UTF16 */
3365 
3366 /*
3367 ** Register a collation sequence factory callback with the database handle
3368 ** db. Replace any previously installed collation sequence factory.
3369 */
3370 int sqlite3_collation_needed(
3371   sqlite3 *db,
3372   void *pCollNeededArg,
3373   void(*xCollNeeded)(void*,sqlite3*,int eTextRep,const char*)
3374 ){
3375 #ifdef SQLITE_ENABLE_API_ARMOR
3376   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3377 #endif
3378   sqlite3_mutex_enter(db->mutex);
3379   db->xCollNeeded = xCollNeeded;
3380   db->xCollNeeded16 = 0;
3381   db->pCollNeededArg = pCollNeededArg;
3382   sqlite3_mutex_leave(db->mutex);
3383   return SQLITE_OK;
3384 }
3385 
3386 #ifndef SQLITE_OMIT_UTF16
3387 /*
3388 ** Register a collation sequence factory callback with the database handle
3389 ** db. Replace any previously installed collation sequence factory.
3390 */
3391 int sqlite3_collation_needed16(
3392   sqlite3 *db,
3393   void *pCollNeededArg,
3394   void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*)
3395 ){
3396 #ifdef SQLITE_ENABLE_API_ARMOR
3397   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3398 #endif
3399   sqlite3_mutex_enter(db->mutex);
3400   db->xCollNeeded = 0;
3401   db->xCollNeeded16 = xCollNeeded16;
3402   db->pCollNeededArg = pCollNeededArg;
3403   sqlite3_mutex_leave(db->mutex);
3404   return SQLITE_OK;
3405 }
3406 #endif /* SQLITE_OMIT_UTF16 */
3407 
3408 #ifndef SQLITE_OMIT_DEPRECATED
3409 /*
3410 ** This function is now an anachronism. It used to be used to recover from a
3411 ** malloc() failure, but SQLite now does this automatically.
3412 */
3413 int sqlite3_global_recover(void){
3414   return SQLITE_OK;
3415 }
3416 #endif
3417 
3418 /*
3419 ** Test to see whether or not the database connection is in autocommit
3420 ** mode.  Return TRUE if it is and FALSE if not.  Autocommit mode is on
3421 ** by default.  Autocommit is disabled by a BEGIN statement and reenabled
3422 ** by the next COMMIT or ROLLBACK.
3423 */
3424 int sqlite3_get_autocommit(sqlite3 *db){
3425 #ifdef SQLITE_ENABLE_API_ARMOR
3426   if( !sqlite3SafetyCheckOk(db) ){
3427     (void)SQLITE_MISUSE_BKPT;
3428     return 0;
3429   }
3430 #endif
3431   return db->autoCommit;
3432 }
3433 
3434 /*
3435 ** The following routines are substitutes for constants SQLITE_CORRUPT,
3436 ** SQLITE_MISUSE, SQLITE_CANTOPEN, SQLITE_NOMEM and possibly other error
3437 ** constants.  They serve two purposes:
3438 **
3439 **   1.  Serve as a convenient place to set a breakpoint in a debugger
3440 **       to detect when version error conditions occurs.
3441 **
3442 **   2.  Invoke sqlite3_log() to provide the source code location where
3443 **       a low-level error is first detected.
3444 */
3445 int sqlite3ReportError(int iErr, int lineno, const char *zType){
3446   sqlite3_log(iErr, "%s at line %d of [%.10s]",
3447               zType, lineno, 20+sqlite3_sourceid());
3448   return iErr;
3449 }
3450 int sqlite3CorruptError(int lineno){
3451   testcase( sqlite3GlobalConfig.xLog!=0 );
3452   return sqlite3ReportError(SQLITE_CORRUPT, lineno, "database corruption");
3453 }
3454 int sqlite3MisuseError(int lineno){
3455   testcase( sqlite3GlobalConfig.xLog!=0 );
3456   return sqlite3ReportError(SQLITE_MISUSE, lineno, "misuse");
3457 }
3458 int sqlite3CantopenError(int lineno){
3459   testcase( sqlite3GlobalConfig.xLog!=0 );
3460   return sqlite3ReportError(SQLITE_CANTOPEN, lineno, "cannot open file");
3461 }
3462 #ifdef SQLITE_DEBUG
3463 int sqlite3CorruptPgnoError(int lineno, Pgno pgno){
3464   char zMsg[100];
3465   sqlite3_snprintf(sizeof(zMsg), zMsg, "database corruption page %d", pgno);
3466   testcase( sqlite3GlobalConfig.xLog!=0 );
3467   return sqlite3ReportError(SQLITE_CORRUPT, lineno, zMsg);
3468 }
3469 int sqlite3NomemError(int lineno){
3470   testcase( sqlite3GlobalConfig.xLog!=0 );
3471   return sqlite3ReportError(SQLITE_NOMEM, lineno, "OOM");
3472 }
3473 int sqlite3IoerrnomemError(int lineno){
3474   testcase( sqlite3GlobalConfig.xLog!=0 );
3475   return sqlite3ReportError(SQLITE_IOERR_NOMEM, lineno, "I/O OOM error");
3476 }
3477 #endif
3478 
3479 #ifndef SQLITE_OMIT_DEPRECATED
3480 /*
3481 ** This is a convenience routine that makes sure that all thread-specific
3482 ** data for this thread has been deallocated.
3483 **
3484 ** SQLite no longer uses thread-specific data so this routine is now a
3485 ** no-op.  It is retained for historical compatibility.
3486 */
3487 void sqlite3_thread_cleanup(void){
3488 }
3489 #endif
3490 
3491 /*
3492 ** Return meta information about a specific column of a database table.
3493 ** See comment in sqlite3.h (sqlite.h.in) for details.
3494 */
3495 int sqlite3_table_column_metadata(
3496   sqlite3 *db,                /* Connection handle */
3497   const char *zDbName,        /* Database name or NULL */
3498   const char *zTableName,     /* Table name */
3499   const char *zColumnName,    /* Column name */
3500   char const **pzDataType,    /* OUTPUT: Declared data type */
3501   char const **pzCollSeq,     /* OUTPUT: Collation sequence name */
3502   int *pNotNull,              /* OUTPUT: True if NOT NULL constraint exists */
3503   int *pPrimaryKey,           /* OUTPUT: True if column part of PK */
3504   int *pAutoinc               /* OUTPUT: True if column is auto-increment */
3505 ){
3506   int rc;
3507   char *zErrMsg = 0;
3508   Table *pTab = 0;
3509   Column *pCol = 0;
3510   int iCol = 0;
3511   char const *zDataType = 0;
3512   char const *zCollSeq = 0;
3513   int notnull = 0;
3514   int primarykey = 0;
3515   int autoinc = 0;
3516 
3517 
3518 #ifdef SQLITE_ENABLE_API_ARMOR
3519   if( !sqlite3SafetyCheckOk(db) || zTableName==0 ){
3520     return SQLITE_MISUSE_BKPT;
3521   }
3522 #endif
3523 
3524   /* Ensure the database schema has been loaded */
3525   sqlite3_mutex_enter(db->mutex);
3526   sqlite3BtreeEnterAll(db);
3527   rc = sqlite3Init(db, &zErrMsg);
3528   if( SQLITE_OK!=rc ){
3529     goto error_out;
3530   }
3531 
3532   /* Locate the table in question */
3533   pTab = sqlite3FindTable(db, zTableName, zDbName);
3534   if( !pTab || pTab->pSelect ){
3535     pTab = 0;
3536     goto error_out;
3537   }
3538 
3539   /* Find the column for which info is requested */
3540   if( zColumnName==0 ){
3541     /* Query for existance of table only */
3542   }else{
3543     for(iCol=0; iCol<pTab->nCol; iCol++){
3544       pCol = &pTab->aCol[iCol];
3545       if( 0==sqlite3StrICmp(pCol->zName, zColumnName) ){
3546         break;
3547       }
3548     }
3549     if( iCol==pTab->nCol ){
3550       if( HasRowid(pTab) && sqlite3IsRowid(zColumnName) ){
3551         iCol = pTab->iPKey;
3552         pCol = iCol>=0 ? &pTab->aCol[iCol] : 0;
3553       }else{
3554         pTab = 0;
3555         goto error_out;
3556       }
3557     }
3558   }
3559 
3560   /* The following block stores the meta information that will be returned
3561   ** to the caller in local variables zDataType, zCollSeq, notnull, primarykey
3562   ** and autoinc. At this point there are two possibilities:
3563   **
3564   **     1. The specified column name was rowid", "oid" or "_rowid_"
3565   **        and there is no explicitly declared IPK column.
3566   **
3567   **     2. The table is not a view and the column name identified an
3568   **        explicitly declared column. Copy meta information from *pCol.
3569   */
3570   if( pCol ){
3571     zDataType = sqlite3ColumnType(pCol,0);
3572     zCollSeq = pCol->zColl;
3573     notnull = pCol->notNull!=0;
3574     primarykey  = (pCol->colFlags & COLFLAG_PRIMKEY)!=0;
3575     autoinc = pTab->iPKey==iCol && (pTab->tabFlags & TF_Autoincrement)!=0;
3576   }else{
3577     zDataType = "INTEGER";
3578     primarykey = 1;
3579   }
3580   if( !zCollSeq ){
3581     zCollSeq = sqlite3StrBINARY;
3582   }
3583 
3584 error_out:
3585   sqlite3BtreeLeaveAll(db);
3586 
3587   /* Whether the function call succeeded or failed, set the output parameters
3588   ** to whatever their local counterparts contain. If an error did occur,
3589   ** this has the effect of zeroing all output parameters.
3590   */
3591   if( pzDataType ) *pzDataType = zDataType;
3592   if( pzCollSeq ) *pzCollSeq = zCollSeq;
3593   if( pNotNull ) *pNotNull = notnull;
3594   if( pPrimaryKey ) *pPrimaryKey = primarykey;
3595   if( pAutoinc ) *pAutoinc = autoinc;
3596 
3597   if( SQLITE_OK==rc && !pTab ){
3598     sqlite3DbFree(db, zErrMsg);
3599     zErrMsg = sqlite3MPrintf(db, "no such table column: %s.%s", zTableName,
3600         zColumnName);
3601     rc = SQLITE_ERROR;
3602   }
3603   sqlite3ErrorWithMsg(db, rc, (zErrMsg?"%s":0), zErrMsg);
3604   sqlite3DbFree(db, zErrMsg);
3605   rc = sqlite3ApiExit(db, rc);
3606   sqlite3_mutex_leave(db->mutex);
3607   return rc;
3608 }
3609 
3610 /*
3611 ** Sleep for a little while.  Return the amount of time slept.
3612 */
3613 int sqlite3_sleep(int ms){
3614   sqlite3_vfs *pVfs;
3615   int rc;
3616   pVfs = sqlite3_vfs_find(0);
3617   if( pVfs==0 ) return 0;
3618 
3619   /* This function works in milliseconds, but the underlying OsSleep()
3620   ** API uses microseconds. Hence the 1000's.
3621   */
3622   rc = (sqlite3OsSleep(pVfs, 1000*ms)/1000);
3623   return rc;
3624 }
3625 
3626 /*
3627 ** Enable or disable the extended result codes.
3628 */
3629 int sqlite3_extended_result_codes(sqlite3 *db, int onoff){
3630 #ifdef SQLITE_ENABLE_API_ARMOR
3631   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3632 #endif
3633   sqlite3_mutex_enter(db->mutex);
3634   db->errMask = onoff ? 0xffffffff : 0xff;
3635   sqlite3_mutex_leave(db->mutex);
3636   return SQLITE_OK;
3637 }
3638 
3639 /*
3640 ** Invoke the xFileControl method on a particular database.
3641 */
3642 int sqlite3_file_control(sqlite3 *db, const char *zDbName, int op, void *pArg){
3643   int rc = SQLITE_ERROR;
3644   Btree *pBtree;
3645 
3646 #ifdef SQLITE_ENABLE_API_ARMOR
3647   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3648 #endif
3649   sqlite3_mutex_enter(db->mutex);
3650   pBtree = sqlite3DbNameToBtree(db, zDbName);
3651   if( pBtree ){
3652     Pager *pPager;
3653     sqlite3_file *fd;
3654     sqlite3BtreeEnter(pBtree);
3655     pPager = sqlite3BtreePager(pBtree);
3656     assert( pPager!=0 );
3657     fd = sqlite3PagerFile(pPager);
3658     assert( fd!=0 );
3659     if( op==SQLITE_FCNTL_FILE_POINTER ){
3660       *(sqlite3_file**)pArg = fd;
3661       rc = SQLITE_OK;
3662     }else if( op==SQLITE_FCNTL_VFS_POINTER ){
3663       *(sqlite3_vfs**)pArg = sqlite3PagerVfs(pPager);
3664       rc = SQLITE_OK;
3665     }else if( op==SQLITE_FCNTL_JOURNAL_POINTER ){
3666       *(sqlite3_file**)pArg = sqlite3PagerJrnlFile(pPager);
3667       rc = SQLITE_OK;
3668     }else{
3669       rc = sqlite3OsFileControl(fd, op, pArg);
3670     }
3671     sqlite3BtreeLeave(pBtree);
3672   }
3673   sqlite3_mutex_leave(db->mutex);
3674   return rc;
3675 }
3676 
3677 /*
3678 ** Interface to the testing logic.
3679 */
3680 int sqlite3_test_control(int op, ...){
3681   int rc = 0;
3682 #ifdef SQLITE_UNTESTABLE
3683   UNUSED_PARAMETER(op);
3684 #else
3685   va_list ap;
3686   va_start(ap, op);
3687   switch( op ){
3688 
3689     /*
3690     ** Save the current state of the PRNG.
3691     */
3692     case SQLITE_TESTCTRL_PRNG_SAVE: {
3693       sqlite3PrngSaveState();
3694       break;
3695     }
3696 
3697     /*
3698     ** Restore the state of the PRNG to the last state saved using
3699     ** PRNG_SAVE.  If PRNG_SAVE has never before been called, then
3700     ** this verb acts like PRNG_RESET.
3701     */
3702     case SQLITE_TESTCTRL_PRNG_RESTORE: {
3703       sqlite3PrngRestoreState();
3704       break;
3705     }
3706 
3707     /*
3708     ** Reset the PRNG back to its uninitialized state.  The next call
3709     ** to sqlite3_randomness() will reseed the PRNG using a single call
3710     ** to the xRandomness method of the default VFS.
3711     */
3712     case SQLITE_TESTCTRL_PRNG_RESET: {
3713       sqlite3_randomness(0,0);
3714       break;
3715     }
3716 
3717     /*
3718     **  sqlite3_test_control(BITVEC_TEST, size, program)
3719     **
3720     ** Run a test against a Bitvec object of size.  The program argument
3721     ** is an array of integers that defines the test.  Return -1 on a
3722     ** memory allocation error, 0 on success, or non-zero for an error.
3723     ** See the sqlite3BitvecBuiltinTest() for additional information.
3724     */
3725     case SQLITE_TESTCTRL_BITVEC_TEST: {
3726       int sz = va_arg(ap, int);
3727       int *aProg = va_arg(ap, int*);
3728       rc = sqlite3BitvecBuiltinTest(sz, aProg);
3729       break;
3730     }
3731 
3732     /*
3733     **  sqlite3_test_control(FAULT_INSTALL, xCallback)
3734     **
3735     ** Arrange to invoke xCallback() whenever sqlite3FaultSim() is called,
3736     ** if xCallback is not NULL.
3737     **
3738     ** As a test of the fault simulator mechanism itself, sqlite3FaultSim(0)
3739     ** is called immediately after installing the new callback and the return
3740     ** value from sqlite3FaultSim(0) becomes the return from
3741     ** sqlite3_test_control().
3742     */
3743     case SQLITE_TESTCTRL_FAULT_INSTALL: {
3744       /* MSVC is picky about pulling func ptrs from va lists.
3745       ** http://support.microsoft.com/kb/47961
3746       ** sqlite3GlobalConfig.xTestCallback = va_arg(ap, int(*)(int));
3747       */
3748       typedef int(*TESTCALLBACKFUNC_t)(int);
3749       sqlite3GlobalConfig.xTestCallback = va_arg(ap, TESTCALLBACKFUNC_t);
3750       rc = sqlite3FaultSim(0);
3751       break;
3752     }
3753 
3754     /*
3755     **  sqlite3_test_control(BENIGN_MALLOC_HOOKS, xBegin, xEnd)
3756     **
3757     ** Register hooks to call to indicate which malloc() failures
3758     ** are benign.
3759     */
3760     case SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS: {
3761       typedef void (*void_function)(void);
3762       void_function xBenignBegin;
3763       void_function xBenignEnd;
3764       xBenignBegin = va_arg(ap, void_function);
3765       xBenignEnd = va_arg(ap, void_function);
3766       sqlite3BenignMallocHooks(xBenignBegin, xBenignEnd);
3767       break;
3768     }
3769 
3770     /*
3771     **  sqlite3_test_control(SQLITE_TESTCTRL_PENDING_BYTE, unsigned int X)
3772     **
3773     ** Set the PENDING byte to the value in the argument, if X>0.
3774     ** Make no changes if X==0.  Return the value of the pending byte
3775     ** as it existing before this routine was called.
3776     **
3777     ** IMPORTANT:  Changing the PENDING byte from 0x40000000 results in
3778     ** an incompatible database file format.  Changing the PENDING byte
3779     ** while any database connection is open results in undefined and
3780     ** deleterious behavior.
3781     */
3782     case SQLITE_TESTCTRL_PENDING_BYTE: {
3783       rc = PENDING_BYTE;
3784 #ifndef SQLITE_OMIT_WSD
3785       {
3786         unsigned int newVal = va_arg(ap, unsigned int);
3787         if( newVal ) sqlite3PendingByte = newVal;
3788       }
3789 #endif
3790       break;
3791     }
3792 
3793     /*
3794     **  sqlite3_test_control(SQLITE_TESTCTRL_ASSERT, int X)
3795     **
3796     ** This action provides a run-time test to see whether or not
3797     ** assert() was enabled at compile-time.  If X is true and assert()
3798     ** is enabled, then the return value is true.  If X is true and
3799     ** assert() is disabled, then the return value is zero.  If X is
3800     ** false and assert() is enabled, then the assertion fires and the
3801     ** process aborts.  If X is false and assert() is disabled, then the
3802     ** return value is zero.
3803     */
3804     case SQLITE_TESTCTRL_ASSERT: {
3805       volatile int x = 0;
3806       assert( /*side-effects-ok*/ (x = va_arg(ap,int))!=0 );
3807       rc = x;
3808       break;
3809     }
3810 
3811 
3812     /*
3813     **  sqlite3_test_control(SQLITE_TESTCTRL_ALWAYS, int X)
3814     **
3815     ** This action provides a run-time test to see how the ALWAYS and
3816     ** NEVER macros were defined at compile-time.
3817     **
3818     ** The return value is ALWAYS(X) if X is true, or 0 if X is false.
3819     **
3820     ** The recommended test is X==2.  If the return value is 2, that means
3821     ** ALWAYS() and NEVER() are both no-op pass-through macros, which is the
3822     ** default setting.  If the return value is 1, then ALWAYS() is either
3823     ** hard-coded to true or else it asserts if its argument is false.
3824     ** The first behavior (hard-coded to true) is the case if
3825     ** SQLITE_TESTCTRL_ASSERT shows that assert() is disabled and the second
3826     ** behavior (assert if the argument to ALWAYS() is false) is the case if
3827     ** SQLITE_TESTCTRL_ASSERT shows that assert() is enabled.
3828     **
3829     ** The run-time test procedure might look something like this:
3830     **
3831     **    if( sqlite3_test_control(SQLITE_TESTCTRL_ALWAYS, 2)==2 ){
3832     **      // ALWAYS() and NEVER() are no-op pass-through macros
3833     **    }else if( sqlite3_test_control(SQLITE_TESTCTRL_ASSERT, 1) ){
3834     **      // ALWAYS(x) asserts that x is true. NEVER(x) asserts x is false.
3835     **    }else{
3836     **      // ALWAYS(x) is a constant 1.  NEVER(x) is a constant 0.
3837     **    }
3838     */
3839     case SQLITE_TESTCTRL_ALWAYS: {
3840       int x = va_arg(ap,int);
3841       rc = x ? ALWAYS(x) : 0;
3842       break;
3843     }
3844 
3845     /*
3846     **   sqlite3_test_control(SQLITE_TESTCTRL_BYTEORDER);
3847     **
3848     ** The integer returned reveals the byte-order of the computer on which
3849     ** SQLite is running:
3850     **
3851     **       1     big-endian,    determined at run-time
3852     **      10     little-endian, determined at run-time
3853     **  432101     big-endian,    determined at compile-time
3854     **  123410     little-endian, determined at compile-time
3855     */
3856     case SQLITE_TESTCTRL_BYTEORDER: {
3857       rc = SQLITE_BYTEORDER*100 + SQLITE_LITTLEENDIAN*10 + SQLITE_BIGENDIAN;
3858       break;
3859     }
3860 
3861     /*   sqlite3_test_control(SQLITE_TESTCTRL_RESERVE, sqlite3 *db, int N)
3862     **
3863     ** Set the nReserve size to N for the main database on the database
3864     ** connection db.
3865     */
3866     case SQLITE_TESTCTRL_RESERVE: {
3867       sqlite3 *db = va_arg(ap, sqlite3*);
3868       int x = va_arg(ap,int);
3869       sqlite3_mutex_enter(db->mutex);
3870       sqlite3BtreeSetPageSize(db->aDb[0].pBt, 0, x, 0);
3871       sqlite3_mutex_leave(db->mutex);
3872       break;
3873     }
3874 
3875     /*  sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS, sqlite3 *db, int N)
3876     **
3877     ** Enable or disable various optimizations for testing purposes.  The
3878     ** argument N is a bitmask of optimizations to be disabled.  For normal
3879     ** operation N should be 0.  The idea is that a test program (like the
3880     ** SQL Logic Test or SLT test module) can run the same SQL multiple times
3881     ** with various optimizations disabled to verify that the same answer
3882     ** is obtained in every case.
3883     */
3884     case SQLITE_TESTCTRL_OPTIMIZATIONS: {
3885       sqlite3 *db = va_arg(ap, sqlite3*);
3886       db->dbOptFlags = (u16)(va_arg(ap, int) & 0xffff);
3887       break;
3888     }
3889 
3890     /*   sqlite3_test_control(SQLITE_TESTCTRL_LOCALTIME_FAULT, int onoff);
3891     **
3892     ** If parameter onoff is non-zero, configure the wrappers so that all
3893     ** subsequent calls to localtime() and variants fail. If onoff is zero,
3894     ** undo this setting.
3895     */
3896     case SQLITE_TESTCTRL_LOCALTIME_FAULT: {
3897       sqlite3GlobalConfig.bLocaltimeFault = va_arg(ap, int);
3898       break;
3899     }
3900 
3901     /*   sqlite3_test_control(SQLITE_TESTCTRL_NEVER_CORRUPT, int);
3902     **
3903     ** Set or clear a flag that indicates that the database file is always well-
3904     ** formed and never corrupt.  This flag is clear by default, indicating that
3905     ** database files might have arbitrary corruption.  Setting the flag during
3906     ** testing causes certain assert() statements in the code to be activated
3907     ** that demonstrat invariants on well-formed database files.
3908     */
3909     case SQLITE_TESTCTRL_NEVER_CORRUPT: {
3910       sqlite3GlobalConfig.neverCorrupt = va_arg(ap, int);
3911       break;
3912     }
3913 
3914     /* Set the threshold at which OP_Once counters reset back to zero.
3915     ** By default this is 0x7ffffffe (over 2 billion), but that value is
3916     ** too big to test in a reasonable amount of time, so this control is
3917     ** provided to set a small and easily reachable reset value.
3918     */
3919     case SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD: {
3920       sqlite3GlobalConfig.iOnceResetThreshold = va_arg(ap, int);
3921       break;
3922     }
3923 
3924     /*   sqlite3_test_control(SQLITE_TESTCTRL_VDBE_COVERAGE, xCallback, ptr);
3925     **
3926     ** Set the VDBE coverage callback function to xCallback with context
3927     ** pointer ptr.
3928     */
3929     case SQLITE_TESTCTRL_VDBE_COVERAGE: {
3930 #ifdef SQLITE_VDBE_COVERAGE
3931       typedef void (*branch_callback)(void*,int,u8,u8);
3932       sqlite3GlobalConfig.xVdbeBranch = va_arg(ap,branch_callback);
3933       sqlite3GlobalConfig.pVdbeBranchArg = va_arg(ap,void*);
3934 #endif
3935       break;
3936     }
3937 
3938     /*   sqlite3_test_control(SQLITE_TESTCTRL_SORTER_MMAP, db, nMax); */
3939     case SQLITE_TESTCTRL_SORTER_MMAP: {
3940       sqlite3 *db = va_arg(ap, sqlite3*);
3941       db->nMaxSorterMmap = va_arg(ap, int);
3942       break;
3943     }
3944 
3945     /*   sqlite3_test_control(SQLITE_TESTCTRL_ISINIT);
3946     **
3947     ** Return SQLITE_OK if SQLite has been initialized and SQLITE_ERROR if
3948     ** not.
3949     */
3950     case SQLITE_TESTCTRL_ISINIT: {
3951       if( sqlite3GlobalConfig.isInit==0 ) rc = SQLITE_ERROR;
3952       break;
3953     }
3954 
3955     /*  sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, db, dbName, onOff, tnum);
3956     **
3957     ** This test control is used to create imposter tables.  "db" is a pointer
3958     ** to the database connection.  dbName is the database name (ex: "main" or
3959     ** "temp") which will receive the imposter.  "onOff" turns imposter mode on
3960     ** or off.  "tnum" is the root page of the b-tree to which the imposter
3961     ** table should connect.
3962     **
3963     ** Enable imposter mode only when the schema has already been parsed.  Then
3964     ** run a single CREATE TABLE statement to construct the imposter table in
3965     ** the parsed schema.  Then turn imposter mode back off again.
3966     **
3967     ** If onOff==0 and tnum>0 then reset the schema for all databases, causing
3968     ** the schema to be reparsed the next time it is needed.  This has the
3969     ** effect of erasing all imposter tables.
3970     */
3971     case SQLITE_TESTCTRL_IMPOSTER: {
3972       sqlite3 *db = va_arg(ap, sqlite3*);
3973       sqlite3_mutex_enter(db->mutex);
3974       db->init.iDb = sqlite3FindDbName(db, va_arg(ap,const char*));
3975       db->init.busy = db->init.imposterTable = va_arg(ap,int);
3976       db->init.newTnum = va_arg(ap,int);
3977       if( db->init.busy==0 && db->init.newTnum>0 ){
3978         sqlite3ResetAllSchemasOfConnection(db);
3979       }
3980       sqlite3_mutex_leave(db->mutex);
3981       break;
3982     }
3983 
3984 #if defined(YYCOVERAGE)
3985     /*  sqlite3_test_control(SQLITE_TESTCTRL_PARSER_COVERAGE, FILE *out)
3986     **
3987     ** This test control (only available when SQLite is compiled with
3988     ** -DYYCOVERAGE) writes a report onto "out" that shows all
3989     ** state/lookahead combinations in the parser state machine
3990     ** which are never exercised.  If any state is missed, make the
3991     ** return code SQLITE_ERROR.
3992     */
3993     case SQLITE_TESTCTRL_PARSER_COVERAGE: {
3994       FILE *out = va_arg(ap, FILE*);
3995       if( sqlite3ParserCoverage(out) ) rc = SQLITE_ERROR;
3996       break;
3997     }
3998 #endif /* defined(YYCOVERAGE) */
3999   }
4000   va_end(ap);
4001 #endif /* SQLITE_UNTESTABLE */
4002   return rc;
4003 }
4004 
4005 /*
4006 ** This is a utility routine, useful to VFS implementations, that checks
4007 ** to see if a database file was a URI that contained a specific query
4008 ** parameter, and if so obtains the value of the query parameter.
4009 **
4010 ** The zFilename argument is the filename pointer passed into the xOpen()
4011 ** method of a VFS implementation.  The zParam argument is the name of the
4012 ** query parameter we seek.  This routine returns the value of the zParam
4013 ** parameter if it exists.  If the parameter does not exist, this routine
4014 ** returns a NULL pointer.
4015 */
4016 const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam){
4017   if( zFilename==0 || zParam==0 ) return 0;
4018   zFilename += sqlite3Strlen30(zFilename) + 1;
4019   while( zFilename[0] ){
4020     int x = strcmp(zFilename, zParam);
4021     zFilename += sqlite3Strlen30(zFilename) + 1;
4022     if( x==0 ) return zFilename;
4023     zFilename += sqlite3Strlen30(zFilename) + 1;
4024   }
4025   return 0;
4026 }
4027 
4028 /*
4029 ** Return a boolean value for a query parameter.
4030 */
4031 int sqlite3_uri_boolean(const char *zFilename, const char *zParam, int bDflt){
4032   const char *z = sqlite3_uri_parameter(zFilename, zParam);
4033   bDflt = bDflt!=0;
4034   return z ? sqlite3GetBoolean(z, bDflt) : bDflt;
4035 }
4036 
4037 /*
4038 ** Return a 64-bit integer value for a query parameter.
4039 */
4040 sqlite3_int64 sqlite3_uri_int64(
4041   const char *zFilename,    /* Filename as passed to xOpen */
4042   const char *zParam,       /* URI parameter sought */
4043   sqlite3_int64 bDflt       /* return if parameter is missing */
4044 ){
4045   const char *z = sqlite3_uri_parameter(zFilename, zParam);
4046   sqlite3_int64 v;
4047   if( z && sqlite3DecOrHexToI64(z, &v)==0 ){
4048     bDflt = v;
4049   }
4050   return bDflt;
4051 }
4052 
4053 /*
4054 ** Return the Btree pointer identified by zDbName.  Return NULL if not found.
4055 */
4056 Btree *sqlite3DbNameToBtree(sqlite3 *db, const char *zDbName){
4057   int iDb = zDbName ? sqlite3FindDbName(db, zDbName) : 0;
4058   return iDb<0 ? 0 : db->aDb[iDb].pBt;
4059 }
4060 
4061 /*
4062 ** Return the filename of the database associated with a database
4063 ** connection.
4064 */
4065 const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName){
4066   Btree *pBt;
4067 #ifdef SQLITE_ENABLE_API_ARMOR
4068   if( !sqlite3SafetyCheckOk(db) ){
4069     (void)SQLITE_MISUSE_BKPT;
4070     return 0;
4071   }
4072 #endif
4073   pBt = sqlite3DbNameToBtree(db, zDbName);
4074   return pBt ? sqlite3BtreeGetFilename(pBt) : 0;
4075 }
4076 
4077 /*
4078 ** Return 1 if database is read-only or 0 if read/write.  Return -1 if
4079 ** no such database exists.
4080 */
4081 int sqlite3_db_readonly(sqlite3 *db, const char *zDbName){
4082   Btree *pBt;
4083 #ifdef SQLITE_ENABLE_API_ARMOR
4084   if( !sqlite3SafetyCheckOk(db) ){
4085     (void)SQLITE_MISUSE_BKPT;
4086     return -1;
4087   }
4088 #endif
4089   pBt = sqlite3DbNameToBtree(db, zDbName);
4090   return pBt ? sqlite3BtreeIsReadonly(pBt) : -1;
4091 }
4092 
4093 #ifdef SQLITE_ENABLE_SNAPSHOT
4094 /*
4095 ** Obtain a snapshot handle for the snapshot of database zDb currently
4096 ** being read by handle db.
4097 */
4098 int sqlite3_snapshot_get(
4099   sqlite3 *db,
4100   const char *zDb,
4101   sqlite3_snapshot **ppSnapshot
4102 ){
4103   int rc = SQLITE_ERROR;
4104 #ifndef SQLITE_OMIT_WAL
4105 
4106 #ifdef SQLITE_ENABLE_API_ARMOR
4107   if( !sqlite3SafetyCheckOk(db) ){
4108     return SQLITE_MISUSE_BKPT;
4109   }
4110 #endif
4111   sqlite3_mutex_enter(db->mutex);
4112 
4113   if( db->autoCommit==0 ){
4114     int iDb = sqlite3FindDbName(db, zDb);
4115     if( iDb==0 || iDb>1 ){
4116       Btree *pBt = db->aDb[iDb].pBt;
4117       if( 0==sqlite3BtreeIsInTrans(pBt) ){
4118         rc = sqlite3BtreeBeginTrans(pBt, 0);
4119         if( rc==SQLITE_OK ){
4120           rc = sqlite3PagerSnapshotGet(sqlite3BtreePager(pBt), ppSnapshot);
4121         }
4122       }
4123     }
4124   }
4125 
4126   sqlite3_mutex_leave(db->mutex);
4127 #endif   /* SQLITE_OMIT_WAL */
4128   return rc;
4129 }
4130 
4131 /*
4132 ** Open a read-transaction on the snapshot idendified by pSnapshot.
4133 */
4134 int sqlite3_snapshot_open(
4135   sqlite3 *db,
4136   const char *zDb,
4137   sqlite3_snapshot *pSnapshot
4138 ){
4139   int rc = SQLITE_ERROR;
4140 #ifndef SQLITE_OMIT_WAL
4141 
4142 #ifdef SQLITE_ENABLE_API_ARMOR
4143   if( !sqlite3SafetyCheckOk(db) ){
4144     return SQLITE_MISUSE_BKPT;
4145   }
4146 #endif
4147   sqlite3_mutex_enter(db->mutex);
4148   if( db->autoCommit==0 ){
4149     int iDb;
4150     iDb = sqlite3FindDbName(db, zDb);
4151     if( iDb==0 || iDb>1 ){
4152       Btree *pBt = db->aDb[iDb].pBt;
4153       if( 0==sqlite3BtreeIsInReadTrans(pBt) ){
4154         rc = sqlite3PagerSnapshotOpen(sqlite3BtreePager(pBt), pSnapshot);
4155         if( rc==SQLITE_OK ){
4156           rc = sqlite3BtreeBeginTrans(pBt, 0);
4157           sqlite3PagerSnapshotOpen(sqlite3BtreePager(pBt), 0);
4158         }
4159       }
4160     }
4161   }
4162 
4163   sqlite3_mutex_leave(db->mutex);
4164 #endif   /* SQLITE_OMIT_WAL */
4165   return rc;
4166 }
4167 
4168 /*
4169 ** Recover as many snapshots as possible from the wal file associated with
4170 ** schema zDb of database db.
4171 */
4172 int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb){
4173   int rc = SQLITE_ERROR;
4174   int iDb;
4175 #ifndef SQLITE_OMIT_WAL
4176 
4177 #ifdef SQLITE_ENABLE_API_ARMOR
4178   if( !sqlite3SafetyCheckOk(db) ){
4179     return SQLITE_MISUSE_BKPT;
4180   }
4181 #endif
4182 
4183   sqlite3_mutex_enter(db->mutex);
4184   iDb = sqlite3FindDbName(db, zDb);
4185   if( iDb==0 || iDb>1 ){
4186     Btree *pBt = db->aDb[iDb].pBt;
4187     if( 0==sqlite3BtreeIsInReadTrans(pBt) ){
4188       rc = sqlite3BtreeBeginTrans(pBt, 0);
4189       if( rc==SQLITE_OK ){
4190         rc = sqlite3PagerSnapshotRecover(sqlite3BtreePager(pBt));
4191         sqlite3BtreeCommit(pBt);
4192       }
4193     }
4194   }
4195   sqlite3_mutex_leave(db->mutex);
4196 #endif   /* SQLITE_OMIT_WAL */
4197   return rc;
4198 }
4199 
4200 /*
4201 ** Free a snapshot handle obtained from sqlite3_snapshot_get().
4202 */
4203 void sqlite3_snapshot_free(sqlite3_snapshot *pSnapshot){
4204   sqlite3_free(pSnapshot);
4205 }
4206 #endif /* SQLITE_ENABLE_SNAPSHOT */
4207 
4208 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
4209 /*
4210 ** Given the name of a compile-time option, return true if that option
4211 ** was used and false if not.
4212 **
4213 ** The name can optionally begin with "SQLITE_" but the "SQLITE_" prefix
4214 ** is not required for a match.
4215 */
4216 int sqlite3_compileoption_used(const char *zOptName){
4217   int i, n;
4218   int nOpt;
4219   const char **azCompileOpt;
4220 
4221 #if SQLITE_ENABLE_API_ARMOR
4222   if( zOptName==0 ){
4223     (void)SQLITE_MISUSE_BKPT;
4224     return 0;
4225   }
4226 #endif
4227 
4228   azCompileOpt = sqlite3CompileOptions(&nOpt);
4229 
4230   if( sqlite3StrNICmp(zOptName, "SQLITE_", 7)==0 ) zOptName += 7;
4231   n = sqlite3Strlen30(zOptName);
4232 
4233   /* Since nOpt is normally in single digits, a linear search is
4234   ** adequate. No need for a binary search. */
4235   for(i=0; i<nOpt; i++){
4236     if( sqlite3StrNICmp(zOptName, azCompileOpt[i], n)==0
4237      && sqlite3IsIdChar((unsigned char)azCompileOpt[i][n])==0
4238     ){
4239       return 1;
4240     }
4241   }
4242   return 0;
4243 }
4244 
4245 /*
4246 ** Return the N-th compile-time option string.  If N is out of range,
4247 ** return a NULL pointer.
4248 */
4249 const char *sqlite3_compileoption_get(int N){
4250   int nOpt;
4251   const char **azCompileOpt;
4252   azCompileOpt = sqlite3CompileOptions(&nOpt);
4253   if( N>=0 && N<nOpt ){
4254     return azCompileOpt[N];
4255   }
4256   return 0;
4257 }
4258 #endif /* SQLITE_OMIT_COMPILEOPTION_DIAGS */
4259