xref: /sqlite-3.40.0/src/main.c (revision 3f09beda)
1 /*
2 ** 2001 September 15
3 **
4 ** The author disclaims copyright to this source code.  In place of
5 ** a legal notice, here is a blessing:
6 **
7 **    May you do good and not evil.
8 **    May you find forgiveness for yourself and forgive others.
9 **    May you share freely, never taking more than you give.
10 **
11 *************************************************************************
12 ** Main file for the SQLite library.  The routines in this file
13 ** implement the programmer interface to the library.  Routines in
14 ** other files are for internal use by SQLite and should not be
15 ** accessed by users of the library.
16 */
17 #include "sqliteInt.h"
18 
19 #ifdef SQLITE_ENABLE_FTS3
20 # include "fts3.h"
21 #endif
22 #ifdef SQLITE_ENABLE_RTREE
23 # include "rtree.h"
24 #endif
25 #ifdef SQLITE_ENABLE_ICU
26 # include "sqliteicu.h"
27 #endif
28 
29 #ifndef SQLITE_AMALGAMATION
30 /* IMPLEMENTATION-OF: R-46656-45156 The sqlite3_version[] string constant
31 ** contains the text of SQLITE_VERSION macro.
32 */
33 const char sqlite3_version[] = SQLITE_VERSION;
34 #endif
35 
36 /* IMPLEMENTATION-OF: R-53536-42575 The sqlite3_libversion() function returns
37 ** a pointer to the to the sqlite3_version[] string constant.
38 */
39 const char *sqlite3_libversion(void){ return sqlite3_version; }
40 
41 /* IMPLEMENTATION-OF: R-63124-39300 The sqlite3_sourceid() function returns a
42 ** pointer to a string constant whose value is the same as the
43 ** SQLITE_SOURCE_ID C preprocessor macro.
44 */
45 const char *sqlite3_sourceid(void){ return SQLITE_SOURCE_ID; }
46 
47 /* IMPLEMENTATION-OF: R-35210-63508 The sqlite3_libversion_number() function
48 ** returns an integer equal to SQLITE_VERSION_NUMBER.
49 */
50 int sqlite3_libversion_number(void){ return SQLITE_VERSION_NUMBER; }
51 
52 /* IMPLEMENTATION-OF: R-20790-14025 The sqlite3_threadsafe() function returns
53 ** zero if and only if SQLite was compiled with mutexing code omitted due to
54 ** the SQLITE_THREADSAFE compile-time option being set to 0.
55 */
56 int sqlite3_threadsafe(void){ return SQLITE_THREADSAFE; }
57 
58 /*
59 ** When compiling the test fixture or with debugging enabled (on Win32),
60 ** this variable being set to non-zero will cause OSTRACE macros to emit
61 ** extra diagnostic information.
62 */
63 #ifdef SQLITE_HAVE_OS_TRACE
64 # ifndef SQLITE_DEBUG_OS_TRACE
65 #   define SQLITE_DEBUG_OS_TRACE 0
66 # endif
67   int sqlite3OSTrace = SQLITE_DEBUG_OS_TRACE;
68 #endif
69 
70 #if !defined(SQLITE_OMIT_TRACE) && defined(SQLITE_ENABLE_IOTRACE)
71 /*
72 ** If the following function pointer is not NULL and if
73 ** SQLITE_ENABLE_IOTRACE is enabled, then messages describing
74 ** I/O active are written using this function.  These messages
75 ** are intended for debugging activity only.
76 */
77 SQLITE_API void (SQLITE_CDECL *sqlite3IoTrace)(const char*, ...) = 0;
78 #endif
79 
80 /*
81 ** If the following global variable points to a string which is the
82 ** name of a directory, then that directory will be used to store
83 ** temporary files.
84 **
85 ** See also the "PRAGMA temp_store_directory" SQL command.
86 */
87 char *sqlite3_temp_directory = 0;
88 
89 /*
90 ** If the following global variable points to a string which is the
91 ** name of a directory, then that directory will be used to store
92 ** all database files specified with a relative pathname.
93 **
94 ** See also the "PRAGMA data_store_directory" SQL command.
95 */
96 char *sqlite3_data_directory = 0;
97 
98 /*
99 ** Initialize SQLite.
100 **
101 ** This routine must be called to initialize the memory allocation,
102 ** VFS, and mutex subsystems prior to doing any serious work with
103 ** SQLite.  But as long as you do not compile with SQLITE_OMIT_AUTOINIT
104 ** this routine will be called automatically by key routines such as
105 ** sqlite3_open().
106 **
107 ** This routine is a no-op except on its very first call for the process,
108 ** or for the first call after a call to sqlite3_shutdown.
109 **
110 ** The first thread to call this routine runs the initialization to
111 ** completion.  If subsequent threads call this routine before the first
112 ** thread has finished the initialization process, then the subsequent
113 ** threads must block until the first thread finishes with the initialization.
114 **
115 ** The first thread might call this routine recursively.  Recursive
116 ** calls to this routine should not block, of course.  Otherwise the
117 ** initialization process would never complete.
118 **
119 ** Let X be the first thread to enter this routine.  Let Y be some other
120 ** thread.  Then while the initial invocation of this routine by X is
121 ** incomplete, it is required that:
122 **
123 **    *  Calls to this routine from Y must block until the outer-most
124 **       call by X completes.
125 **
126 **    *  Recursive calls to this routine from thread X return immediately
127 **       without blocking.
128 */
129 int sqlite3_initialize(void){
130   MUTEX_LOGIC( sqlite3_mutex *pMaster; )       /* The main static mutex */
131   int rc;                                      /* Result code */
132 #ifdef SQLITE_EXTRA_INIT
133   int bRunExtraInit = 0;                       /* Extra initialization needed */
134 #endif
135 
136 #ifdef SQLITE_OMIT_WSD
137   rc = sqlite3_wsd_init(4096, 24);
138   if( rc!=SQLITE_OK ){
139     return rc;
140   }
141 #endif
142 
143   /* If the following assert() fails on some obscure processor/compiler
144   ** combination, the work-around is to set the correct pointer
145   ** size at compile-time using -DSQLITE_PTRSIZE=n compile-time option */
146   assert( SQLITE_PTRSIZE==sizeof(char*) );
147 
148   /* If SQLite is already completely initialized, then this call
149   ** to sqlite3_initialize() should be a no-op.  But the initialization
150   ** must be complete.  So isInit must not be set until the very end
151   ** of this routine.
152   */
153   if( sqlite3GlobalConfig.isInit ) return SQLITE_OK;
154 
155   /* Make sure the mutex subsystem is initialized.  If unable to
156   ** initialize the mutex subsystem, return early with the error.
157   ** If the system is so sick that we are unable to allocate a mutex,
158   ** there is not much SQLite is going to be able to do.
159   **
160   ** The mutex subsystem must take care of serializing its own
161   ** initialization.
162   */
163   rc = sqlite3MutexInit();
164   if( rc ) return rc;
165 
166   /* Initialize the malloc() system and the recursive pInitMutex mutex.
167   ** This operation is protected by the STATIC_MASTER mutex.  Note that
168   ** MutexAlloc() is called for a static mutex prior to initializing the
169   ** malloc subsystem - this implies that the allocation of a static
170   ** mutex must not require support from the malloc subsystem.
171   */
172   MUTEX_LOGIC( pMaster = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER); )
173   sqlite3_mutex_enter(pMaster);
174   sqlite3GlobalConfig.isMutexInit = 1;
175   if( !sqlite3GlobalConfig.isMallocInit ){
176     rc = sqlite3MallocInit();
177   }
178   if( rc==SQLITE_OK ){
179     sqlite3GlobalConfig.isMallocInit = 1;
180     if( !sqlite3GlobalConfig.pInitMutex ){
181       sqlite3GlobalConfig.pInitMutex =
182            sqlite3MutexAlloc(SQLITE_MUTEX_RECURSIVE);
183       if( sqlite3GlobalConfig.bCoreMutex && !sqlite3GlobalConfig.pInitMutex ){
184         rc = SQLITE_NOMEM;
185       }
186     }
187   }
188   if( rc==SQLITE_OK ){
189     sqlite3GlobalConfig.nRefInitMutex++;
190   }
191   sqlite3_mutex_leave(pMaster);
192 
193   /* If rc is not SQLITE_OK at this point, then either the malloc
194   ** subsystem could not be initialized or the system failed to allocate
195   ** the pInitMutex mutex. Return an error in either case.  */
196   if( rc!=SQLITE_OK ){
197     return rc;
198   }
199 
200   /* Do the rest of the initialization under the recursive mutex so
201   ** that we will be able to handle recursive calls into
202   ** sqlite3_initialize().  The recursive calls normally come through
203   ** sqlite3_os_init() when it invokes sqlite3_vfs_register(), but other
204   ** recursive calls might also be possible.
205   **
206   ** IMPLEMENTATION-OF: R-00140-37445 SQLite automatically serializes calls
207   ** to the xInit method, so the xInit method need not be threadsafe.
208   **
209   ** The following mutex is what serializes access to the appdef pcache xInit
210   ** methods.  The sqlite3_pcache_methods.xInit() all is embedded in the
211   ** call to sqlite3PcacheInitialize().
212   */
213   sqlite3_mutex_enter(sqlite3GlobalConfig.pInitMutex);
214   if( sqlite3GlobalConfig.isInit==0 && sqlite3GlobalConfig.inProgress==0 ){
215     FuncDefHash *pHash = &GLOBAL(FuncDefHash, sqlite3GlobalFunctions);
216     sqlite3GlobalConfig.inProgress = 1;
217     memset(pHash, 0, sizeof(sqlite3GlobalFunctions));
218     sqlite3RegisterGlobalFunctions();
219     if( sqlite3GlobalConfig.isPCacheInit==0 ){
220       rc = sqlite3PcacheInitialize();
221     }
222     if( rc==SQLITE_OK ){
223       sqlite3GlobalConfig.isPCacheInit = 1;
224       rc = sqlite3OsInit();
225     }
226     if( rc==SQLITE_OK ){
227       sqlite3PCacheBufferSetup( sqlite3GlobalConfig.pPage,
228           sqlite3GlobalConfig.szPage, sqlite3GlobalConfig.nPage);
229       sqlite3GlobalConfig.isInit = 1;
230 #ifdef SQLITE_EXTRA_INIT
231       bRunExtraInit = 1;
232 #endif
233     }
234     sqlite3GlobalConfig.inProgress = 0;
235   }
236   sqlite3_mutex_leave(sqlite3GlobalConfig.pInitMutex);
237 
238   /* Go back under the static mutex and clean up the recursive
239   ** mutex to prevent a resource leak.
240   */
241   sqlite3_mutex_enter(pMaster);
242   sqlite3GlobalConfig.nRefInitMutex--;
243   if( sqlite3GlobalConfig.nRefInitMutex<=0 ){
244     assert( sqlite3GlobalConfig.nRefInitMutex==0 );
245     sqlite3_mutex_free(sqlite3GlobalConfig.pInitMutex);
246     sqlite3GlobalConfig.pInitMutex = 0;
247   }
248   sqlite3_mutex_leave(pMaster);
249 
250   /* The following is just a sanity check to make sure SQLite has
251   ** been compiled correctly.  It is important to run this code, but
252   ** we don't want to run it too often and soak up CPU cycles for no
253   ** reason.  So we run it once during initialization.
254   */
255 #ifndef NDEBUG
256 #ifndef SQLITE_OMIT_FLOATING_POINT
257   /* This section of code's only "output" is via assert() statements. */
258   if ( rc==SQLITE_OK ){
259     u64 x = (((u64)1)<<63)-1;
260     double y;
261     assert(sizeof(x)==8);
262     assert(sizeof(x)==sizeof(y));
263     memcpy(&y, &x, 8);
264     assert( sqlite3IsNaN(y) );
265   }
266 #endif
267 #endif
268 
269   /* Do extra initialization steps requested by the SQLITE_EXTRA_INIT
270   ** compile-time option.
271   */
272 #ifdef SQLITE_EXTRA_INIT
273   if( bRunExtraInit ){
274     int SQLITE_EXTRA_INIT(const char*);
275     rc = SQLITE_EXTRA_INIT(0);
276   }
277 #endif
278 
279   return rc;
280 }
281 
282 /*
283 ** Undo the effects of sqlite3_initialize().  Must not be called while
284 ** there are outstanding database connections or memory allocations or
285 ** while any part of SQLite is otherwise in use in any thread.  This
286 ** routine is not threadsafe.  But it is safe to invoke this routine
287 ** on when SQLite is already shut down.  If SQLite is already shut down
288 ** when this routine is invoked, then this routine is a harmless no-op.
289 */
290 int sqlite3_shutdown(void){
291 #ifdef SQLITE_OMIT_WSD
292   int rc = sqlite3_wsd_init(4096, 24);
293   if( rc!=SQLITE_OK ){
294     return rc;
295   }
296 #endif
297 
298   if( sqlite3GlobalConfig.isInit ){
299 #ifdef SQLITE_EXTRA_SHUTDOWN
300     void SQLITE_EXTRA_SHUTDOWN(void);
301     SQLITE_EXTRA_SHUTDOWN();
302 #endif
303     sqlite3_os_end();
304     sqlite3_reset_auto_extension();
305     sqlite3GlobalConfig.isInit = 0;
306   }
307   if( sqlite3GlobalConfig.isPCacheInit ){
308     sqlite3PcacheShutdown();
309     sqlite3GlobalConfig.isPCacheInit = 0;
310   }
311   if( sqlite3GlobalConfig.isMallocInit ){
312     sqlite3MallocEnd();
313     sqlite3GlobalConfig.isMallocInit = 0;
314 
315 #ifndef SQLITE_OMIT_SHUTDOWN_DIRECTORIES
316     /* The heap subsystem has now been shutdown and these values are supposed
317     ** to be NULL or point to memory that was obtained from sqlite3_malloc(),
318     ** which would rely on that heap subsystem; therefore, make sure these
319     ** values cannot refer to heap memory that was just invalidated when the
320     ** heap subsystem was shutdown.  This is only done if the current call to
321     ** this function resulted in the heap subsystem actually being shutdown.
322     */
323     sqlite3_data_directory = 0;
324     sqlite3_temp_directory = 0;
325 #endif
326   }
327   if( sqlite3GlobalConfig.isMutexInit ){
328     sqlite3MutexEnd();
329     sqlite3GlobalConfig.isMutexInit = 0;
330   }
331 
332   return SQLITE_OK;
333 }
334 
335 /*
336 ** This API allows applications to modify the global configuration of
337 ** the SQLite library at run-time.
338 **
339 ** This routine should only be called when there are no outstanding
340 ** database connections or memory allocations.  This routine is not
341 ** threadsafe.  Failure to heed these warnings can lead to unpredictable
342 ** behavior.
343 */
344 int sqlite3_config(int op, ...){
345   va_list ap;
346   int rc = SQLITE_OK;
347 
348   /* sqlite3_config() shall return SQLITE_MISUSE if it is invoked while
349   ** the SQLite library is in use. */
350   if( sqlite3GlobalConfig.isInit ) return SQLITE_MISUSE_BKPT;
351 
352   va_start(ap, op);
353   switch( op ){
354 
355     /* Mutex configuration options are only available in a threadsafe
356     ** compile.
357     */
358 #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0  /* IMP: R-54466-46756 */
359     case SQLITE_CONFIG_SINGLETHREAD: {
360       /* EVIDENCE-OF: R-02748-19096 This option sets the threading mode to
361       ** Single-thread. */
362       sqlite3GlobalConfig.bCoreMutex = 0;  /* Disable mutex on core */
363       sqlite3GlobalConfig.bFullMutex = 0;  /* Disable mutex on connections */
364       break;
365     }
366 #endif
367 #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-20520-54086 */
368     case SQLITE_CONFIG_MULTITHREAD: {
369       /* EVIDENCE-OF: R-14374-42468 This option sets the threading mode to
370       ** Multi-thread. */
371       sqlite3GlobalConfig.bCoreMutex = 1;  /* Enable mutex on core */
372       sqlite3GlobalConfig.bFullMutex = 0;  /* Disable mutex on connections */
373       break;
374     }
375 #endif
376 #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-59593-21810 */
377     case SQLITE_CONFIG_SERIALIZED: {
378       /* EVIDENCE-OF: R-41220-51800 This option sets the threading mode to
379       ** Serialized. */
380       sqlite3GlobalConfig.bCoreMutex = 1;  /* Enable mutex on core */
381       sqlite3GlobalConfig.bFullMutex = 1;  /* Enable mutex on connections */
382       break;
383     }
384 #endif
385 #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-63666-48755 */
386     case SQLITE_CONFIG_MUTEX: {
387       /* Specify an alternative mutex implementation */
388       sqlite3GlobalConfig.mutex = *va_arg(ap, sqlite3_mutex_methods*);
389       break;
390     }
391 #endif
392 #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-14450-37597 */
393     case SQLITE_CONFIG_GETMUTEX: {
394       /* Retrieve the current mutex implementation */
395       *va_arg(ap, sqlite3_mutex_methods*) = sqlite3GlobalConfig.mutex;
396       break;
397     }
398 #endif
399 
400     case SQLITE_CONFIG_MALLOC: {
401       /* EVIDENCE-OF: R-55594-21030 The SQLITE_CONFIG_MALLOC option takes a
402       ** single argument which is a pointer to an instance of the
403       ** sqlite3_mem_methods structure. The argument specifies alternative
404       ** low-level memory allocation routines to be used in place of the memory
405       ** allocation routines built into SQLite. */
406       sqlite3GlobalConfig.m = *va_arg(ap, sqlite3_mem_methods*);
407       break;
408     }
409     case SQLITE_CONFIG_GETMALLOC: {
410       /* EVIDENCE-OF: R-51213-46414 The SQLITE_CONFIG_GETMALLOC option takes a
411       ** single argument which is a pointer to an instance of the
412       ** sqlite3_mem_methods structure. The sqlite3_mem_methods structure is
413       ** filled with the currently defined memory allocation routines. */
414       if( sqlite3GlobalConfig.m.xMalloc==0 ) sqlite3MemSetDefault();
415       *va_arg(ap, sqlite3_mem_methods*) = sqlite3GlobalConfig.m;
416       break;
417     }
418     case SQLITE_CONFIG_MEMSTATUS: {
419       /* EVIDENCE-OF: R-61275-35157 The SQLITE_CONFIG_MEMSTATUS option takes
420       ** single argument of type int, interpreted as a boolean, which enables
421       ** or disables the collection of memory allocation statistics. */
422       sqlite3GlobalConfig.bMemstat = va_arg(ap, int);
423       break;
424     }
425     case SQLITE_CONFIG_SCRATCH: {
426       /* EVIDENCE-OF: R-08404-60887 There are three arguments to
427       ** SQLITE_CONFIG_SCRATCH: A pointer an 8-byte aligned memory buffer from
428       ** which the scratch allocations will be drawn, the size of each scratch
429       ** allocation (sz), and the maximum number of scratch allocations (N). */
430       sqlite3GlobalConfig.pScratch = va_arg(ap, void*);
431       sqlite3GlobalConfig.szScratch = va_arg(ap, int);
432       sqlite3GlobalConfig.nScratch = va_arg(ap, int);
433       break;
434     }
435     case SQLITE_CONFIG_PAGECACHE: {
436       /* EVIDENCE-OF: R-31408-40510 There are three arguments to
437       ** SQLITE_CONFIG_PAGECACHE: A pointer to 8-byte aligned memory, the size
438       ** of each page buffer (sz), and the number of pages (N). */
439       sqlite3GlobalConfig.pPage = va_arg(ap, void*);
440       sqlite3GlobalConfig.szPage = va_arg(ap, int);
441       sqlite3GlobalConfig.nPage = va_arg(ap, int);
442       break;
443     }
444     case SQLITE_CONFIG_PCACHE_HDRSZ: {
445       /* EVIDENCE-OF: R-39100-27317 The SQLITE_CONFIG_PCACHE_HDRSZ option takes
446       ** a single parameter which is a pointer to an integer and writes into
447       ** that integer the number of extra bytes per page required for each page
448       ** in SQLITE_CONFIG_PAGECACHE. */
449       *va_arg(ap, int*) =
450           sqlite3HeaderSizeBtree() +
451           sqlite3HeaderSizePcache() +
452           sqlite3HeaderSizePcache1();
453       break;
454     }
455 
456     case SQLITE_CONFIG_PCACHE: {
457       /* no-op */
458       break;
459     }
460     case SQLITE_CONFIG_GETPCACHE: {
461       /* now an error */
462       rc = SQLITE_ERROR;
463       break;
464     }
465 
466     case SQLITE_CONFIG_PCACHE2: {
467       /* EVIDENCE-OF: R-63325-48378 The SQLITE_CONFIG_PCACHE2 option takes a
468       ** single argument which is a pointer to an sqlite3_pcache_methods2
469       ** object. This object specifies the interface to a custom page cache
470       ** implementation. */
471       sqlite3GlobalConfig.pcache2 = *va_arg(ap, sqlite3_pcache_methods2*);
472       break;
473     }
474     case SQLITE_CONFIG_GETPCACHE2: {
475       /* EVIDENCE-OF: R-22035-46182 The SQLITE_CONFIG_GETPCACHE2 option takes a
476       ** single argument which is a pointer to an sqlite3_pcache_methods2
477       ** object. SQLite copies of the current page cache implementation into
478       ** that object. */
479       if( sqlite3GlobalConfig.pcache2.xInit==0 ){
480         sqlite3PCacheSetDefault();
481       }
482       *va_arg(ap, sqlite3_pcache_methods2*) = sqlite3GlobalConfig.pcache2;
483       break;
484     }
485 
486 /* EVIDENCE-OF: R-06626-12911 The SQLITE_CONFIG_HEAP option is only
487 ** available if SQLite is compiled with either SQLITE_ENABLE_MEMSYS3 or
488 ** SQLITE_ENABLE_MEMSYS5 and returns SQLITE_ERROR if invoked otherwise. */
489 #if defined(SQLITE_ENABLE_MEMSYS3) || defined(SQLITE_ENABLE_MEMSYS5)
490     case SQLITE_CONFIG_HEAP: {
491       /* EVIDENCE-OF: R-19854-42126 There are three arguments to
492       ** SQLITE_CONFIG_HEAP: An 8-byte aligned pointer to the memory, the
493       ** number of bytes in the memory buffer, and the minimum allocation size.
494       */
495       sqlite3GlobalConfig.pHeap = va_arg(ap, void*);
496       sqlite3GlobalConfig.nHeap = va_arg(ap, int);
497       sqlite3GlobalConfig.mnReq = va_arg(ap, int);
498 
499       if( sqlite3GlobalConfig.mnReq<1 ){
500         sqlite3GlobalConfig.mnReq = 1;
501       }else if( sqlite3GlobalConfig.mnReq>(1<<12) ){
502         /* cap min request size at 2^12 */
503         sqlite3GlobalConfig.mnReq = (1<<12);
504       }
505 
506       if( sqlite3GlobalConfig.pHeap==0 ){
507         /* EVIDENCE-OF: R-49920-60189 If the first pointer (the memory pointer)
508         ** is NULL, then SQLite reverts to using its default memory allocator
509         ** (the system malloc() implementation), undoing any prior invocation of
510         ** SQLITE_CONFIG_MALLOC.
511         **
512         ** Setting sqlite3GlobalConfig.m to all zeros will cause malloc to
513         ** revert to its default implementation when sqlite3_initialize() is run
514         */
515         memset(&sqlite3GlobalConfig.m, 0, sizeof(sqlite3GlobalConfig.m));
516       }else{
517         /* EVIDENCE-OF: R-61006-08918 If the memory pointer is not NULL then the
518         ** alternative memory allocator is engaged to handle all of SQLites
519         ** memory allocation needs. */
520 #ifdef SQLITE_ENABLE_MEMSYS3
521         sqlite3GlobalConfig.m = *sqlite3MemGetMemsys3();
522 #endif
523 #ifdef SQLITE_ENABLE_MEMSYS5
524         sqlite3GlobalConfig.m = *sqlite3MemGetMemsys5();
525 #endif
526       }
527       break;
528     }
529 #endif
530 
531     case SQLITE_CONFIG_LOOKASIDE: {
532       sqlite3GlobalConfig.szLookaside = va_arg(ap, int);
533       sqlite3GlobalConfig.nLookaside = va_arg(ap, int);
534       break;
535     }
536 
537     /* Record a pointer to the logger function and its first argument.
538     ** The default is NULL.  Logging is disabled if the function pointer is
539     ** NULL.
540     */
541     case SQLITE_CONFIG_LOG: {
542       /* MSVC is picky about pulling func ptrs from va lists.
543       ** http://support.microsoft.com/kb/47961
544       ** sqlite3GlobalConfig.xLog = va_arg(ap, void(*)(void*,int,const char*));
545       */
546       typedef void(*LOGFUNC_t)(void*,int,const char*);
547       sqlite3GlobalConfig.xLog = va_arg(ap, LOGFUNC_t);
548       sqlite3GlobalConfig.pLogArg = va_arg(ap, void*);
549       break;
550     }
551 
552     /* EVIDENCE-OF: R-55548-33817 The compile-time setting for URI filenames
553     ** can be changed at start-time using the
554     ** sqlite3_config(SQLITE_CONFIG_URI,1) or
555     ** sqlite3_config(SQLITE_CONFIG_URI,0) configuration calls.
556     */
557     case SQLITE_CONFIG_URI: {
558       /* EVIDENCE-OF: R-25451-61125 The SQLITE_CONFIG_URI option takes a single
559       ** argument of type int. If non-zero, then URI handling is globally
560       ** enabled. If the parameter is zero, then URI handling is globally
561       ** disabled. */
562       sqlite3GlobalConfig.bOpenUri = va_arg(ap, int);
563       break;
564     }
565 
566     case SQLITE_CONFIG_COVERING_INDEX_SCAN: {
567       /* EVIDENCE-OF: R-36592-02772 The SQLITE_CONFIG_COVERING_INDEX_SCAN
568       ** option takes a single integer argument which is interpreted as a
569       ** boolean in order to enable or disable the use of covering indices for
570       ** full table scans in the query optimizer. */
571       sqlite3GlobalConfig.bUseCis = va_arg(ap, int);
572       break;
573     }
574 
575 #ifdef SQLITE_ENABLE_SQLLOG
576     case SQLITE_CONFIG_SQLLOG: {
577       typedef void(*SQLLOGFUNC_t)(void*, sqlite3*, const char*, int);
578       sqlite3GlobalConfig.xSqllog = va_arg(ap, SQLLOGFUNC_t);
579       sqlite3GlobalConfig.pSqllogArg = va_arg(ap, void *);
580       break;
581     }
582 #endif
583 
584     case SQLITE_CONFIG_MMAP_SIZE: {
585       /* EVIDENCE-OF: R-58063-38258 SQLITE_CONFIG_MMAP_SIZE takes two 64-bit
586       ** integer (sqlite3_int64) values that are the default mmap size limit
587       ** (the default setting for PRAGMA mmap_size) and the maximum allowed
588       ** mmap size limit. */
589       sqlite3_int64 szMmap = va_arg(ap, sqlite3_int64);
590       sqlite3_int64 mxMmap = va_arg(ap, sqlite3_int64);
591       /* EVIDENCE-OF: R-53367-43190 If either argument to this option is
592       ** negative, then that argument is changed to its compile-time default.
593       **
594       ** EVIDENCE-OF: R-34993-45031 The maximum allowed mmap size will be
595       ** silently truncated if necessary so that it does not exceed the
596       ** compile-time maximum mmap size set by the SQLITE_MAX_MMAP_SIZE
597       ** compile-time option.
598       */
599       if( mxMmap<0 || mxMmap>SQLITE_MAX_MMAP_SIZE ){
600         mxMmap = SQLITE_MAX_MMAP_SIZE;
601       }
602       if( szMmap<0 ) szMmap = SQLITE_DEFAULT_MMAP_SIZE;
603       if( szMmap>mxMmap) szMmap = mxMmap;
604       sqlite3GlobalConfig.mxMmap = mxMmap;
605       sqlite3GlobalConfig.szMmap = szMmap;
606       break;
607     }
608 
609 #if SQLITE_OS_WIN && defined(SQLITE_WIN32_MALLOC) /* IMP: R-04780-55815 */
610     case SQLITE_CONFIG_WIN32_HEAPSIZE: {
611       /* EVIDENCE-OF: R-34926-03360 SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit
612       ** unsigned integer value that specifies the maximum size of the created
613       ** heap. */
614       sqlite3GlobalConfig.nHeap = va_arg(ap, int);
615       break;
616     }
617 #endif
618 
619     case SQLITE_CONFIG_PMASZ: {
620       sqlite3GlobalConfig.szPma = va_arg(ap, unsigned int);
621       break;
622     }
623 
624     default: {
625       rc = SQLITE_ERROR;
626       break;
627     }
628   }
629   va_end(ap);
630   return rc;
631 }
632 
633 /*
634 ** Set up the lookaside buffers for a database connection.
635 ** Return SQLITE_OK on success.
636 ** If lookaside is already active, return SQLITE_BUSY.
637 **
638 ** The sz parameter is the number of bytes in each lookaside slot.
639 ** The cnt parameter is the number of slots.  If pStart is NULL the
640 ** space for the lookaside memory is obtained from sqlite3_malloc().
641 ** If pStart is not NULL then it is sz*cnt bytes of memory to use for
642 ** the lookaside memory.
643 */
644 static int setupLookaside(sqlite3 *db, void *pBuf, int sz, int cnt){
645   void *pStart;
646   if( db->lookaside.nOut ){
647     return SQLITE_BUSY;
648   }
649   /* Free any existing lookaside buffer for this handle before
650   ** allocating a new one so we don't have to have space for
651   ** both at the same time.
652   */
653   if( db->lookaside.bMalloced ){
654     sqlite3_free(db->lookaside.pStart);
655   }
656   /* The size of a lookaside slot after ROUNDDOWN8 needs to be larger
657   ** than a pointer to be useful.
658   */
659   sz = ROUNDDOWN8(sz);  /* IMP: R-33038-09382 */
660   if( sz<=(int)sizeof(LookasideSlot*) ) sz = 0;
661   if( cnt<0 ) cnt = 0;
662   if( sz==0 || cnt==0 ){
663     sz = 0;
664     pStart = 0;
665   }else if( pBuf==0 ){
666     sqlite3BeginBenignMalloc();
667     pStart = sqlite3Malloc( sz*cnt );  /* IMP: R-61949-35727 */
668     sqlite3EndBenignMalloc();
669     if( pStart ) cnt = sqlite3MallocSize(pStart)/sz;
670   }else{
671     pStart = pBuf;
672   }
673   db->lookaside.pStart = pStart;
674   db->lookaside.pFree = 0;
675   db->lookaside.sz = (u16)sz;
676   if( pStart ){
677     int i;
678     LookasideSlot *p;
679     assert( sz > (int)sizeof(LookasideSlot*) );
680     p = (LookasideSlot*)pStart;
681     for(i=cnt-1; i>=0; i--){
682       p->pNext = db->lookaside.pFree;
683       db->lookaside.pFree = p;
684       p = (LookasideSlot*)&((u8*)p)[sz];
685     }
686     db->lookaside.pEnd = p;
687     db->lookaside.bEnabled = 1;
688     db->lookaside.bMalloced = pBuf==0 ?1:0;
689   }else{
690     db->lookaside.pStart = db;
691     db->lookaside.pEnd = db;
692     db->lookaside.bEnabled = 0;
693     db->lookaside.bMalloced = 0;
694   }
695   return SQLITE_OK;
696 }
697 
698 /*
699 ** Return the mutex associated with a database connection.
700 */
701 sqlite3_mutex *sqlite3_db_mutex(sqlite3 *db){
702 #ifdef SQLITE_ENABLE_API_ARMOR
703   if( !sqlite3SafetyCheckOk(db) ){
704     (void)SQLITE_MISUSE_BKPT;
705     return 0;
706   }
707 #endif
708   return db->mutex;
709 }
710 
711 /*
712 ** Free up as much memory as we can from the given database
713 ** connection.
714 */
715 int sqlite3_db_release_memory(sqlite3 *db){
716   int i;
717 
718 #ifdef SQLITE_ENABLE_API_ARMOR
719   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
720 #endif
721   sqlite3_mutex_enter(db->mutex);
722   sqlite3BtreeEnterAll(db);
723   for(i=0; i<db->nDb; i++){
724     Btree *pBt = db->aDb[i].pBt;
725     if( pBt ){
726       Pager *pPager = sqlite3BtreePager(pBt);
727       sqlite3PagerShrink(pPager);
728     }
729   }
730   sqlite3BtreeLeaveAll(db);
731   sqlite3_mutex_leave(db->mutex);
732   return SQLITE_OK;
733 }
734 
735 /*
736 ** Configuration settings for an individual database connection
737 */
738 int sqlite3_db_config(sqlite3 *db, int op, ...){
739   va_list ap;
740   int rc;
741   va_start(ap, op);
742   switch( op ){
743     case SQLITE_DBCONFIG_LOOKASIDE: {
744       void *pBuf = va_arg(ap, void*); /* IMP: R-26835-10964 */
745       int sz = va_arg(ap, int);       /* IMP: R-47871-25994 */
746       int cnt = va_arg(ap, int);      /* IMP: R-04460-53386 */
747       rc = setupLookaside(db, pBuf, sz, cnt);
748       break;
749     }
750     default: {
751       static const struct {
752         int op;      /* The opcode */
753         u32 mask;    /* Mask of the bit in sqlite3.flags to set/clear */
754       } aFlagOp[] = {
755         { SQLITE_DBCONFIG_ENABLE_FKEY,    SQLITE_ForeignKeys    },
756         { SQLITE_DBCONFIG_ENABLE_TRIGGER, SQLITE_EnableTrigger  },
757       };
758       unsigned int i;
759       rc = SQLITE_ERROR; /* IMP: R-42790-23372 */
760       for(i=0; i<ArraySize(aFlagOp); i++){
761         if( aFlagOp[i].op==op ){
762           int onoff = va_arg(ap, int);
763           int *pRes = va_arg(ap, int*);
764           int oldFlags = db->flags;
765           if( onoff>0 ){
766             db->flags |= aFlagOp[i].mask;
767           }else if( onoff==0 ){
768             db->flags &= ~aFlagOp[i].mask;
769           }
770           if( oldFlags!=db->flags ){
771             sqlite3ExpirePreparedStatements(db);
772           }
773           if( pRes ){
774             *pRes = (db->flags & aFlagOp[i].mask)!=0;
775           }
776           rc = SQLITE_OK;
777           break;
778         }
779       }
780       break;
781     }
782   }
783   va_end(ap);
784   return rc;
785 }
786 
787 
788 /*
789 ** Return true if the buffer z[0..n-1] contains all spaces.
790 */
791 static int allSpaces(const char *z, int n){
792   while( n>0 && z[n-1]==' ' ){ n--; }
793   return n==0;
794 }
795 
796 /*
797 ** This is the default collating function named "BINARY" which is always
798 ** available.
799 **
800 ** If the padFlag argument is not NULL then space padding at the end
801 ** of strings is ignored.  This implements the RTRIM collation.
802 */
803 static int binCollFunc(
804   void *padFlag,
805   int nKey1, const void *pKey1,
806   int nKey2, const void *pKey2
807 ){
808   int rc, n;
809   n = nKey1<nKey2 ? nKey1 : nKey2;
810   /* EVIDENCE-OF: R-65033-28449 The built-in BINARY collation compares
811   ** strings byte by byte using the memcmp() function from the standard C
812   ** library. */
813   rc = memcmp(pKey1, pKey2, n);
814   if( rc==0 ){
815     if( padFlag
816      && allSpaces(((char*)pKey1)+n, nKey1-n)
817      && allSpaces(((char*)pKey2)+n, nKey2-n)
818     ){
819       /* EVIDENCE-OF: R-31624-24737 RTRIM is like BINARY except that extra
820       ** spaces at the end of either string do not change the result. In other
821       ** words, strings will compare equal to one another as long as they
822       ** differ only in the number of spaces at the end.
823       */
824     }else{
825       rc = nKey1 - nKey2;
826     }
827   }
828   return rc;
829 }
830 
831 /*
832 ** Another built-in collating sequence: NOCASE.
833 **
834 ** This collating sequence is intended to be used for "case independent
835 ** comparison". SQLite's knowledge of upper and lower case equivalents
836 ** extends only to the 26 characters used in the English language.
837 **
838 ** At the moment there is only a UTF-8 implementation.
839 */
840 static int nocaseCollatingFunc(
841   void *NotUsed,
842   int nKey1, const void *pKey1,
843   int nKey2, const void *pKey2
844 ){
845   int r = sqlite3StrNICmp(
846       (const char *)pKey1, (const char *)pKey2, (nKey1<nKey2)?nKey1:nKey2);
847   UNUSED_PARAMETER(NotUsed);
848   if( 0==r ){
849     r = nKey1-nKey2;
850   }
851   return r;
852 }
853 
854 /*
855 ** Return the ROWID of the most recent insert
856 */
857 sqlite_int64 sqlite3_last_insert_rowid(sqlite3 *db){
858 #ifdef SQLITE_ENABLE_API_ARMOR
859   if( !sqlite3SafetyCheckOk(db) ){
860     (void)SQLITE_MISUSE_BKPT;
861     return 0;
862   }
863 #endif
864   return db->lastRowid;
865 }
866 
867 /*
868 ** Return the number of changes in the most recent call to sqlite3_exec().
869 */
870 int sqlite3_changes(sqlite3 *db){
871 #ifdef SQLITE_ENABLE_API_ARMOR
872   if( !sqlite3SafetyCheckOk(db) ){
873     (void)SQLITE_MISUSE_BKPT;
874     return 0;
875   }
876 #endif
877   return db->nChange;
878 }
879 
880 /*
881 ** Return the number of changes since the database handle was opened.
882 */
883 int sqlite3_total_changes(sqlite3 *db){
884 #ifdef SQLITE_ENABLE_API_ARMOR
885   if( !sqlite3SafetyCheckOk(db) ){
886     (void)SQLITE_MISUSE_BKPT;
887     return 0;
888   }
889 #endif
890   return db->nTotalChange;
891 }
892 
893 /*
894 ** Close all open savepoints. This function only manipulates fields of the
895 ** database handle object, it does not close any savepoints that may be open
896 ** at the b-tree/pager level.
897 */
898 void sqlite3CloseSavepoints(sqlite3 *db){
899   while( db->pSavepoint ){
900     Savepoint *pTmp = db->pSavepoint;
901     db->pSavepoint = pTmp->pNext;
902     sqlite3DbFree(db, pTmp);
903   }
904   db->nSavepoint = 0;
905   db->nStatement = 0;
906   db->isTransactionSavepoint = 0;
907 }
908 
909 /*
910 ** Invoke the destructor function associated with FuncDef p, if any. Except,
911 ** if this is not the last copy of the function, do not invoke it. Multiple
912 ** copies of a single function are created when create_function() is called
913 ** with SQLITE_ANY as the encoding.
914 */
915 static void functionDestroy(sqlite3 *db, FuncDef *p){
916   FuncDestructor *pDestructor = p->pDestructor;
917   if( pDestructor ){
918     pDestructor->nRef--;
919     if( pDestructor->nRef==0 ){
920       pDestructor->xDestroy(pDestructor->pUserData);
921       sqlite3DbFree(db, pDestructor);
922     }
923   }
924 }
925 
926 /*
927 ** Disconnect all sqlite3_vtab objects that belong to database connection
928 ** db. This is called when db is being closed.
929 */
930 static void disconnectAllVtab(sqlite3 *db){
931 #ifndef SQLITE_OMIT_VIRTUALTABLE
932   int i;
933   sqlite3BtreeEnterAll(db);
934   for(i=0; i<db->nDb; i++){
935     Schema *pSchema = db->aDb[i].pSchema;
936     if( db->aDb[i].pSchema ){
937       HashElem *p;
938       for(p=sqliteHashFirst(&pSchema->tblHash); p; p=sqliteHashNext(p)){
939         Table *pTab = (Table *)sqliteHashData(p);
940         if( IsVirtual(pTab) ) sqlite3VtabDisconnect(db, pTab);
941       }
942     }
943   }
944   sqlite3VtabUnlockList(db);
945   sqlite3BtreeLeaveAll(db);
946 #else
947   UNUSED_PARAMETER(db);
948 #endif
949 }
950 
951 /*
952 ** Return TRUE if database connection db has unfinalized prepared
953 ** statements or unfinished sqlite3_backup objects.
954 */
955 static int connectionIsBusy(sqlite3 *db){
956   int j;
957   assert( sqlite3_mutex_held(db->mutex) );
958   if( db->pVdbe ) return 1;
959   for(j=0; j<db->nDb; j++){
960     Btree *pBt = db->aDb[j].pBt;
961     if( pBt && sqlite3BtreeIsInBackup(pBt) ) return 1;
962   }
963   return 0;
964 }
965 
966 /*
967 ** Close an existing SQLite database
968 */
969 static int sqlite3Close(sqlite3 *db, int forceZombie){
970   if( !db ){
971     /* EVIDENCE-OF: R-63257-11740 Calling sqlite3_close() or
972     ** sqlite3_close_v2() with a NULL pointer argument is a harmless no-op. */
973     return SQLITE_OK;
974   }
975   if( !sqlite3SafetyCheckSickOrOk(db) ){
976     return SQLITE_MISUSE_BKPT;
977   }
978   sqlite3_mutex_enter(db->mutex);
979 
980   /* Force xDisconnect calls on all virtual tables */
981   disconnectAllVtab(db);
982 
983   /* If a transaction is open, the disconnectAllVtab() call above
984   ** will not have called the xDisconnect() method on any virtual
985   ** tables in the db->aVTrans[] array. The following sqlite3VtabRollback()
986   ** call will do so. We need to do this before the check for active
987   ** SQL statements below, as the v-table implementation may be storing
988   ** some prepared statements internally.
989   */
990   sqlite3VtabRollback(db);
991 
992   /* Legacy behavior (sqlite3_close() behavior) is to return
993   ** SQLITE_BUSY if the connection can not be closed immediately.
994   */
995   if( !forceZombie && connectionIsBusy(db) ){
996     sqlite3ErrorWithMsg(db, SQLITE_BUSY, "unable to close due to unfinalized "
997        "statements or unfinished backups");
998     sqlite3_mutex_leave(db->mutex);
999     return SQLITE_BUSY;
1000   }
1001 
1002 #ifdef SQLITE_ENABLE_SQLLOG
1003   if( sqlite3GlobalConfig.xSqllog ){
1004     /* Closing the handle. Fourth parameter is passed the value 2. */
1005     sqlite3GlobalConfig.xSqllog(sqlite3GlobalConfig.pSqllogArg, db, 0, 2);
1006   }
1007 #endif
1008 
1009   /* Convert the connection into a zombie and then close it.
1010   */
1011   db->magic = SQLITE_MAGIC_ZOMBIE;
1012   sqlite3LeaveMutexAndCloseZombie(db);
1013   return SQLITE_OK;
1014 }
1015 
1016 /*
1017 ** Two variations on the public interface for closing a database
1018 ** connection. The sqlite3_close() version returns SQLITE_BUSY and
1019 ** leaves the connection option if there are unfinalized prepared
1020 ** statements or unfinished sqlite3_backups.  The sqlite3_close_v2()
1021 ** version forces the connection to become a zombie if there are
1022 ** unclosed resources, and arranges for deallocation when the last
1023 ** prepare statement or sqlite3_backup closes.
1024 */
1025 int sqlite3_close(sqlite3 *db){ return sqlite3Close(db,0); }
1026 int sqlite3_close_v2(sqlite3 *db){ return sqlite3Close(db,1); }
1027 
1028 
1029 /*
1030 ** Close the mutex on database connection db.
1031 **
1032 ** Furthermore, if database connection db is a zombie (meaning that there
1033 ** has been a prior call to sqlite3_close(db) or sqlite3_close_v2(db)) and
1034 ** every sqlite3_stmt has now been finalized and every sqlite3_backup has
1035 ** finished, then free all resources.
1036 */
1037 void sqlite3LeaveMutexAndCloseZombie(sqlite3 *db){
1038   HashElem *i;                    /* Hash table iterator */
1039   int j;
1040 
1041   /* If there are outstanding sqlite3_stmt or sqlite3_backup objects
1042   ** or if the connection has not yet been closed by sqlite3_close_v2(),
1043   ** then just leave the mutex and return.
1044   */
1045   if( db->magic!=SQLITE_MAGIC_ZOMBIE || connectionIsBusy(db) ){
1046     sqlite3_mutex_leave(db->mutex);
1047     return;
1048   }
1049 
1050   /* If we reach this point, it means that the database connection has
1051   ** closed all sqlite3_stmt and sqlite3_backup objects and has been
1052   ** passed to sqlite3_close (meaning that it is a zombie).  Therefore,
1053   ** go ahead and free all resources.
1054   */
1055 
1056   /* If a transaction is open, roll it back. This also ensures that if
1057   ** any database schemas have been modified by an uncommitted transaction
1058   ** they are reset. And that the required b-tree mutex is held to make
1059   ** the pager rollback and schema reset an atomic operation. */
1060   sqlite3RollbackAll(db, SQLITE_OK);
1061 
1062   /* Free any outstanding Savepoint structures. */
1063   sqlite3CloseSavepoints(db);
1064 
1065   /* Close all database connections */
1066   for(j=0; j<db->nDb; j++){
1067     struct Db *pDb = &db->aDb[j];
1068     if( pDb->pBt ){
1069       sqlite3BtreeClose(pDb->pBt);
1070       pDb->pBt = 0;
1071       if( j!=1 ){
1072         pDb->pSchema = 0;
1073       }
1074     }
1075   }
1076   /* Clear the TEMP schema separately and last */
1077   if( db->aDb[1].pSchema ){
1078     sqlite3SchemaClear(db->aDb[1].pSchema);
1079   }
1080   sqlite3VtabUnlockList(db);
1081 
1082   /* Free up the array of auxiliary databases */
1083   sqlite3CollapseDatabaseArray(db);
1084   assert( db->nDb<=2 );
1085   assert( db->aDb==db->aDbStatic );
1086 
1087   /* Tell the code in notify.c that the connection no longer holds any
1088   ** locks and does not require any further unlock-notify callbacks.
1089   */
1090   sqlite3ConnectionClosed(db);
1091 
1092   for(j=0; j<ArraySize(db->aFunc.a); j++){
1093     FuncDef *pNext, *pHash, *p;
1094     for(p=db->aFunc.a[j]; p; p=pHash){
1095       pHash = p->pHash;
1096       while( p ){
1097         functionDestroy(db, p);
1098         pNext = p->pNext;
1099         sqlite3DbFree(db, p);
1100         p = pNext;
1101       }
1102     }
1103   }
1104   for(i=sqliteHashFirst(&db->aCollSeq); i; i=sqliteHashNext(i)){
1105     CollSeq *pColl = (CollSeq *)sqliteHashData(i);
1106     /* Invoke any destructors registered for collation sequence user data. */
1107     for(j=0; j<3; j++){
1108       if( pColl[j].xDel ){
1109         pColl[j].xDel(pColl[j].pUser);
1110       }
1111     }
1112     sqlite3DbFree(db, pColl);
1113   }
1114   sqlite3HashClear(&db->aCollSeq);
1115 #ifndef SQLITE_OMIT_VIRTUALTABLE
1116   for(i=sqliteHashFirst(&db->aModule); i; i=sqliteHashNext(i)){
1117     Module *pMod = (Module *)sqliteHashData(i);
1118     if( pMod->xDestroy ){
1119       pMod->xDestroy(pMod->pAux);
1120     }
1121     sqlite3DbFree(db, pMod);
1122   }
1123   sqlite3HashClear(&db->aModule);
1124 #endif
1125 
1126   sqlite3Error(db, SQLITE_OK); /* Deallocates any cached error strings. */
1127   sqlite3ValueFree(db->pErr);
1128   sqlite3CloseExtensions(db);
1129 #if SQLITE_USER_AUTHENTICATION
1130   sqlite3_free(db->auth.zAuthUser);
1131   sqlite3_free(db->auth.zAuthPW);
1132 #endif
1133 
1134   db->magic = SQLITE_MAGIC_ERROR;
1135 
1136   /* The temp-database schema is allocated differently from the other schema
1137   ** objects (using sqliteMalloc() directly, instead of sqlite3BtreeSchema()).
1138   ** So it needs to be freed here. Todo: Why not roll the temp schema into
1139   ** the same sqliteMalloc() as the one that allocates the database
1140   ** structure?
1141   */
1142   sqlite3DbFree(db, db->aDb[1].pSchema);
1143   sqlite3_mutex_leave(db->mutex);
1144   db->magic = SQLITE_MAGIC_CLOSED;
1145   sqlite3_mutex_free(db->mutex);
1146   assert( db->lookaside.nOut==0 );  /* Fails on a lookaside memory leak */
1147   if( db->lookaside.bMalloced ){
1148     sqlite3_free(db->lookaside.pStart);
1149   }
1150   sqlite3_free(db);
1151 }
1152 
1153 /*
1154 ** Rollback all database files.  If tripCode is not SQLITE_OK, then
1155 ** any write cursors are invalidated ("tripped" - as in "tripping a circuit
1156 ** breaker") and made to return tripCode if there are any further
1157 ** attempts to use that cursor.  Read cursors remain open and valid
1158 ** but are "saved" in case the table pages are moved around.
1159 */
1160 void sqlite3RollbackAll(sqlite3 *db, int tripCode){
1161   int i;
1162   int inTrans = 0;
1163   int schemaChange;
1164   assert( sqlite3_mutex_held(db->mutex) );
1165   sqlite3BeginBenignMalloc();
1166 
1167   /* Obtain all b-tree mutexes before making any calls to BtreeRollback().
1168   ** This is important in case the transaction being rolled back has
1169   ** modified the database schema. If the b-tree mutexes are not taken
1170   ** here, then another shared-cache connection might sneak in between
1171   ** the database rollback and schema reset, which can cause false
1172   ** corruption reports in some cases.  */
1173   sqlite3BtreeEnterAll(db);
1174   schemaChange = (db->flags & SQLITE_InternChanges)!=0 && db->init.busy==0;
1175 
1176   for(i=0; i<db->nDb; i++){
1177     Btree *p = db->aDb[i].pBt;
1178     if( p ){
1179       if( sqlite3BtreeIsInTrans(p) ){
1180         inTrans = 1;
1181       }
1182       sqlite3BtreeRollback(p, tripCode, !schemaChange);
1183     }
1184   }
1185   sqlite3VtabRollback(db);
1186   sqlite3EndBenignMalloc();
1187 
1188   if( (db->flags&SQLITE_InternChanges)!=0 && db->init.busy==0 ){
1189     sqlite3ExpirePreparedStatements(db);
1190     sqlite3ResetAllSchemasOfConnection(db);
1191   }
1192   sqlite3BtreeLeaveAll(db);
1193 
1194   /* Any deferred constraint violations have now been resolved. */
1195   db->nDeferredCons = 0;
1196   db->nDeferredImmCons = 0;
1197   db->flags &= ~SQLITE_DeferFKs;
1198 
1199   /* If one has been configured, invoke the rollback-hook callback */
1200   if( db->xRollbackCallback && (inTrans || !db->autoCommit) ){
1201     db->xRollbackCallback(db->pRollbackArg);
1202   }
1203 }
1204 
1205 /*
1206 ** Return a static string containing the name corresponding to the error code
1207 ** specified in the argument.
1208 */
1209 #if defined(SQLITE_NEED_ERR_NAME)
1210 const char *sqlite3ErrName(int rc){
1211   const char *zName = 0;
1212   int i, origRc = rc;
1213   for(i=0; i<2 && zName==0; i++, rc &= 0xff){
1214     switch( rc ){
1215       case SQLITE_OK:                 zName = "SQLITE_OK";                break;
1216       case SQLITE_ERROR:              zName = "SQLITE_ERROR";             break;
1217       case SQLITE_INTERNAL:           zName = "SQLITE_INTERNAL";          break;
1218       case SQLITE_PERM:               zName = "SQLITE_PERM";              break;
1219       case SQLITE_ABORT:              zName = "SQLITE_ABORT";             break;
1220       case SQLITE_ABORT_ROLLBACK:     zName = "SQLITE_ABORT_ROLLBACK";    break;
1221       case SQLITE_BUSY:               zName = "SQLITE_BUSY";              break;
1222       case SQLITE_BUSY_RECOVERY:      zName = "SQLITE_BUSY_RECOVERY";     break;
1223       case SQLITE_BUSY_SNAPSHOT:      zName = "SQLITE_BUSY_SNAPSHOT";     break;
1224       case SQLITE_LOCKED:             zName = "SQLITE_LOCKED";            break;
1225       case SQLITE_LOCKED_SHAREDCACHE: zName = "SQLITE_LOCKED_SHAREDCACHE";break;
1226       case SQLITE_NOMEM:              zName = "SQLITE_NOMEM";             break;
1227       case SQLITE_READONLY:           zName = "SQLITE_READONLY";          break;
1228       case SQLITE_READONLY_RECOVERY:  zName = "SQLITE_READONLY_RECOVERY"; break;
1229       case SQLITE_READONLY_CANTLOCK:  zName = "SQLITE_READONLY_CANTLOCK"; break;
1230       case SQLITE_READONLY_ROLLBACK:  zName = "SQLITE_READONLY_ROLLBACK"; break;
1231       case SQLITE_READONLY_DBMOVED:   zName = "SQLITE_READONLY_DBMOVED";  break;
1232       case SQLITE_INTERRUPT:          zName = "SQLITE_INTERRUPT";         break;
1233       case SQLITE_IOERR:              zName = "SQLITE_IOERR";             break;
1234       case SQLITE_IOERR_READ:         zName = "SQLITE_IOERR_READ";        break;
1235       case SQLITE_IOERR_SHORT_READ:   zName = "SQLITE_IOERR_SHORT_READ";  break;
1236       case SQLITE_IOERR_WRITE:        zName = "SQLITE_IOERR_WRITE";       break;
1237       case SQLITE_IOERR_FSYNC:        zName = "SQLITE_IOERR_FSYNC";       break;
1238       case SQLITE_IOERR_DIR_FSYNC:    zName = "SQLITE_IOERR_DIR_FSYNC";   break;
1239       case SQLITE_IOERR_TRUNCATE:     zName = "SQLITE_IOERR_TRUNCATE";    break;
1240       case SQLITE_IOERR_FSTAT:        zName = "SQLITE_IOERR_FSTAT";       break;
1241       case SQLITE_IOERR_UNLOCK:       zName = "SQLITE_IOERR_UNLOCK";      break;
1242       case SQLITE_IOERR_RDLOCK:       zName = "SQLITE_IOERR_RDLOCK";      break;
1243       case SQLITE_IOERR_DELETE:       zName = "SQLITE_IOERR_DELETE";      break;
1244       case SQLITE_IOERR_NOMEM:        zName = "SQLITE_IOERR_NOMEM";       break;
1245       case SQLITE_IOERR_ACCESS:       zName = "SQLITE_IOERR_ACCESS";      break;
1246       case SQLITE_IOERR_CHECKRESERVEDLOCK:
1247                                 zName = "SQLITE_IOERR_CHECKRESERVEDLOCK"; break;
1248       case SQLITE_IOERR_LOCK:         zName = "SQLITE_IOERR_LOCK";        break;
1249       case SQLITE_IOERR_CLOSE:        zName = "SQLITE_IOERR_CLOSE";       break;
1250       case SQLITE_IOERR_DIR_CLOSE:    zName = "SQLITE_IOERR_DIR_CLOSE";   break;
1251       case SQLITE_IOERR_SHMOPEN:      zName = "SQLITE_IOERR_SHMOPEN";     break;
1252       case SQLITE_IOERR_SHMSIZE:      zName = "SQLITE_IOERR_SHMSIZE";     break;
1253       case SQLITE_IOERR_SHMLOCK:      zName = "SQLITE_IOERR_SHMLOCK";     break;
1254       case SQLITE_IOERR_SHMMAP:       zName = "SQLITE_IOERR_SHMMAP";      break;
1255       case SQLITE_IOERR_SEEK:         zName = "SQLITE_IOERR_SEEK";        break;
1256       case SQLITE_IOERR_DELETE_NOENT: zName = "SQLITE_IOERR_DELETE_NOENT";break;
1257       case SQLITE_IOERR_MMAP:         zName = "SQLITE_IOERR_MMAP";        break;
1258       case SQLITE_IOERR_GETTEMPPATH:  zName = "SQLITE_IOERR_GETTEMPPATH"; break;
1259       case SQLITE_IOERR_CONVPATH:     zName = "SQLITE_IOERR_CONVPATH";    break;
1260       case SQLITE_CORRUPT:            zName = "SQLITE_CORRUPT";           break;
1261       case SQLITE_CORRUPT_VTAB:       zName = "SQLITE_CORRUPT_VTAB";      break;
1262       case SQLITE_NOTFOUND:           zName = "SQLITE_NOTFOUND";          break;
1263       case SQLITE_FULL:               zName = "SQLITE_FULL";              break;
1264       case SQLITE_CANTOPEN:           zName = "SQLITE_CANTOPEN";          break;
1265       case SQLITE_CANTOPEN_NOTEMPDIR: zName = "SQLITE_CANTOPEN_NOTEMPDIR";break;
1266       case SQLITE_CANTOPEN_ISDIR:     zName = "SQLITE_CANTOPEN_ISDIR";    break;
1267       case SQLITE_CANTOPEN_FULLPATH:  zName = "SQLITE_CANTOPEN_FULLPATH"; break;
1268       case SQLITE_CANTOPEN_CONVPATH:  zName = "SQLITE_CANTOPEN_CONVPATH"; break;
1269       case SQLITE_PROTOCOL:           zName = "SQLITE_PROTOCOL";          break;
1270       case SQLITE_EMPTY:              zName = "SQLITE_EMPTY";             break;
1271       case SQLITE_SCHEMA:             zName = "SQLITE_SCHEMA";            break;
1272       case SQLITE_TOOBIG:             zName = "SQLITE_TOOBIG";            break;
1273       case SQLITE_CONSTRAINT:         zName = "SQLITE_CONSTRAINT";        break;
1274       case SQLITE_CONSTRAINT_UNIQUE:  zName = "SQLITE_CONSTRAINT_UNIQUE"; break;
1275       case SQLITE_CONSTRAINT_TRIGGER: zName = "SQLITE_CONSTRAINT_TRIGGER";break;
1276       case SQLITE_CONSTRAINT_FOREIGNKEY:
1277                                 zName = "SQLITE_CONSTRAINT_FOREIGNKEY";   break;
1278       case SQLITE_CONSTRAINT_CHECK:   zName = "SQLITE_CONSTRAINT_CHECK";  break;
1279       case SQLITE_CONSTRAINT_PRIMARYKEY:
1280                                 zName = "SQLITE_CONSTRAINT_PRIMARYKEY";   break;
1281       case SQLITE_CONSTRAINT_NOTNULL: zName = "SQLITE_CONSTRAINT_NOTNULL";break;
1282       case SQLITE_CONSTRAINT_COMMITHOOK:
1283                                 zName = "SQLITE_CONSTRAINT_COMMITHOOK";   break;
1284       case SQLITE_CONSTRAINT_VTAB:    zName = "SQLITE_CONSTRAINT_VTAB";   break;
1285       case SQLITE_CONSTRAINT_FUNCTION:
1286                                 zName = "SQLITE_CONSTRAINT_FUNCTION";     break;
1287       case SQLITE_CONSTRAINT_ROWID:   zName = "SQLITE_CONSTRAINT_ROWID";  break;
1288       case SQLITE_MISMATCH:           zName = "SQLITE_MISMATCH";          break;
1289       case SQLITE_MISUSE:             zName = "SQLITE_MISUSE";            break;
1290       case SQLITE_NOLFS:              zName = "SQLITE_NOLFS";             break;
1291       case SQLITE_AUTH:               zName = "SQLITE_AUTH";              break;
1292       case SQLITE_FORMAT:             zName = "SQLITE_FORMAT";            break;
1293       case SQLITE_RANGE:              zName = "SQLITE_RANGE";             break;
1294       case SQLITE_NOTADB:             zName = "SQLITE_NOTADB";            break;
1295       case SQLITE_ROW:                zName = "SQLITE_ROW";               break;
1296       case SQLITE_NOTICE:             zName = "SQLITE_NOTICE";            break;
1297       case SQLITE_NOTICE_RECOVER_WAL: zName = "SQLITE_NOTICE_RECOVER_WAL";break;
1298       case SQLITE_NOTICE_RECOVER_ROLLBACK:
1299                                 zName = "SQLITE_NOTICE_RECOVER_ROLLBACK"; break;
1300       case SQLITE_WARNING:            zName = "SQLITE_WARNING";           break;
1301       case SQLITE_WARNING_AUTOINDEX:  zName = "SQLITE_WARNING_AUTOINDEX"; break;
1302       case SQLITE_DONE:               zName = "SQLITE_DONE";              break;
1303     }
1304   }
1305   if( zName==0 ){
1306     static char zBuf[50];
1307     sqlite3_snprintf(sizeof(zBuf), zBuf, "SQLITE_UNKNOWN(%d)", origRc);
1308     zName = zBuf;
1309   }
1310   return zName;
1311 }
1312 #endif
1313 
1314 /*
1315 ** Return a static string that describes the kind of error specified in the
1316 ** argument.
1317 */
1318 const char *sqlite3ErrStr(int rc){
1319   static const char* const aMsg[] = {
1320     /* SQLITE_OK          */ "not an error",
1321     /* SQLITE_ERROR       */ "SQL logic error or missing database",
1322     /* SQLITE_INTERNAL    */ 0,
1323     /* SQLITE_PERM        */ "access permission denied",
1324     /* SQLITE_ABORT       */ "callback requested query abort",
1325     /* SQLITE_BUSY        */ "database is locked",
1326     /* SQLITE_LOCKED      */ "database table is locked",
1327     /* SQLITE_NOMEM       */ "out of memory",
1328     /* SQLITE_READONLY    */ "attempt to write a readonly database",
1329     /* SQLITE_INTERRUPT   */ "interrupted",
1330     /* SQLITE_IOERR       */ "disk I/O error",
1331     /* SQLITE_CORRUPT     */ "database disk image is malformed",
1332     /* SQLITE_NOTFOUND    */ "unknown operation",
1333     /* SQLITE_FULL        */ "database or disk is full",
1334     /* SQLITE_CANTOPEN    */ "unable to open database file",
1335     /* SQLITE_PROTOCOL    */ "locking protocol",
1336     /* SQLITE_EMPTY       */ "table contains no data",
1337     /* SQLITE_SCHEMA      */ "database schema has changed",
1338     /* SQLITE_TOOBIG      */ "string or blob too big",
1339     /* SQLITE_CONSTRAINT  */ "constraint failed",
1340     /* SQLITE_MISMATCH    */ "datatype mismatch",
1341     /* SQLITE_MISUSE      */ "library routine called out of sequence",
1342     /* SQLITE_NOLFS       */ "large file support is disabled",
1343     /* SQLITE_AUTH        */ "authorization denied",
1344     /* SQLITE_FORMAT      */ "auxiliary database format error",
1345     /* SQLITE_RANGE       */ "bind or column index out of range",
1346     /* SQLITE_NOTADB      */ "file is encrypted or is not a database",
1347   };
1348   const char *zErr = "unknown error";
1349   switch( rc ){
1350     case SQLITE_ABORT_ROLLBACK: {
1351       zErr = "abort due to ROLLBACK";
1352       break;
1353     }
1354     default: {
1355       rc &= 0xff;
1356       if( ALWAYS(rc>=0) && rc<ArraySize(aMsg) && aMsg[rc]!=0 ){
1357         zErr = aMsg[rc];
1358       }
1359       break;
1360     }
1361   }
1362   return zErr;
1363 }
1364 
1365 /*
1366 ** This routine implements a busy callback that sleeps and tries
1367 ** again until a timeout value is reached.  The timeout value is
1368 ** an integer number of milliseconds passed in as the first
1369 ** argument.
1370 */
1371 static int sqliteDefaultBusyCallback(
1372  void *ptr,               /* Database connection */
1373  int count                /* Number of times table has been busy */
1374 ){
1375 #if SQLITE_OS_WIN || HAVE_USLEEP
1376   static const u8 delays[] =
1377      { 1, 2, 5, 10, 15, 20, 25, 25,  25,  50,  50, 100 };
1378   static const u8 totals[] =
1379      { 0, 1, 3,  8, 18, 33, 53, 78, 103, 128, 178, 228 };
1380 # define NDELAY ArraySize(delays)
1381   sqlite3 *db = (sqlite3 *)ptr;
1382   int timeout = db->busyTimeout;
1383   int delay, prior;
1384 
1385   assert( count>=0 );
1386   if( count < NDELAY ){
1387     delay = delays[count];
1388     prior = totals[count];
1389   }else{
1390     delay = delays[NDELAY-1];
1391     prior = totals[NDELAY-1] + delay*(count-(NDELAY-1));
1392   }
1393   if( prior + delay > timeout ){
1394     delay = timeout - prior;
1395     if( delay<=0 ) return 0;
1396   }
1397   sqlite3OsSleep(db->pVfs, delay*1000);
1398   return 1;
1399 #else
1400   sqlite3 *db = (sqlite3 *)ptr;
1401   int timeout = ((sqlite3 *)ptr)->busyTimeout;
1402   if( (count+1)*1000 > timeout ){
1403     return 0;
1404   }
1405   sqlite3OsSleep(db->pVfs, 1000000);
1406   return 1;
1407 #endif
1408 }
1409 
1410 /*
1411 ** Invoke the given busy handler.
1412 **
1413 ** This routine is called when an operation failed with a lock.
1414 ** If this routine returns non-zero, the lock is retried.  If it
1415 ** returns 0, the operation aborts with an SQLITE_BUSY error.
1416 */
1417 int sqlite3InvokeBusyHandler(BusyHandler *p){
1418   int rc;
1419   if( NEVER(p==0) || p->xFunc==0 || p->nBusy<0 ) return 0;
1420   rc = p->xFunc(p->pArg, p->nBusy);
1421   if( rc==0 ){
1422     p->nBusy = -1;
1423   }else{
1424     p->nBusy++;
1425   }
1426   return rc;
1427 }
1428 
1429 /*
1430 ** This routine sets the busy callback for an Sqlite database to the
1431 ** given callback function with the given argument.
1432 */
1433 int sqlite3_busy_handler(
1434   sqlite3 *db,
1435   int (*xBusy)(void*,int),
1436   void *pArg
1437 ){
1438 #ifdef SQLITE_ENABLE_API_ARMOR
1439   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
1440 #endif
1441   sqlite3_mutex_enter(db->mutex);
1442   db->busyHandler.xFunc = xBusy;
1443   db->busyHandler.pArg = pArg;
1444   db->busyHandler.nBusy = 0;
1445   db->busyTimeout = 0;
1446   sqlite3_mutex_leave(db->mutex);
1447   return SQLITE_OK;
1448 }
1449 
1450 #ifndef SQLITE_OMIT_PROGRESS_CALLBACK
1451 /*
1452 ** This routine sets the progress callback for an Sqlite database to the
1453 ** given callback function with the given argument. The progress callback will
1454 ** be invoked every nOps opcodes.
1455 */
1456 void sqlite3_progress_handler(
1457   sqlite3 *db,
1458   int nOps,
1459   int (*xProgress)(void*),
1460   void *pArg
1461 ){
1462 #ifdef SQLITE_ENABLE_API_ARMOR
1463   if( !sqlite3SafetyCheckOk(db) ){
1464     (void)SQLITE_MISUSE_BKPT;
1465     return;
1466   }
1467 #endif
1468   sqlite3_mutex_enter(db->mutex);
1469   if( nOps>0 ){
1470     db->xProgress = xProgress;
1471     db->nProgressOps = (unsigned)nOps;
1472     db->pProgressArg = pArg;
1473   }else{
1474     db->xProgress = 0;
1475     db->nProgressOps = 0;
1476     db->pProgressArg = 0;
1477   }
1478   sqlite3_mutex_leave(db->mutex);
1479 }
1480 #endif
1481 
1482 
1483 /*
1484 ** This routine installs a default busy handler that waits for the
1485 ** specified number of milliseconds before returning 0.
1486 */
1487 int sqlite3_busy_timeout(sqlite3 *db, int ms){
1488 #ifdef SQLITE_ENABLE_API_ARMOR
1489   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
1490 #endif
1491   if( ms>0 ){
1492     sqlite3_busy_handler(db, sqliteDefaultBusyCallback, (void*)db);
1493     db->busyTimeout = ms;
1494   }else{
1495     sqlite3_busy_handler(db, 0, 0);
1496   }
1497   return SQLITE_OK;
1498 }
1499 
1500 /*
1501 ** Cause any pending operation to stop at its earliest opportunity.
1502 */
1503 void sqlite3_interrupt(sqlite3 *db){
1504 #ifdef SQLITE_ENABLE_API_ARMOR
1505   if( !sqlite3SafetyCheckOk(db) ){
1506     (void)SQLITE_MISUSE_BKPT;
1507     return;
1508   }
1509 #endif
1510   db->u1.isInterrupted = 1;
1511 }
1512 
1513 
1514 /*
1515 ** This function is exactly the same as sqlite3_create_function(), except
1516 ** that it is designed to be called by internal code. The difference is
1517 ** that if a malloc() fails in sqlite3_create_function(), an error code
1518 ** is returned and the mallocFailed flag cleared.
1519 */
1520 int sqlite3CreateFunc(
1521   sqlite3 *db,
1522   const char *zFunctionName,
1523   int nArg,
1524   int enc,
1525   void *pUserData,
1526   void (*xFunc)(sqlite3_context*,int,sqlite3_value **),
1527   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
1528   void (*xFinal)(sqlite3_context*),
1529   FuncDestructor *pDestructor
1530 ){
1531   FuncDef *p;
1532   int nName;
1533   int extraFlags;
1534 
1535   assert( sqlite3_mutex_held(db->mutex) );
1536   if( zFunctionName==0 ||
1537       (xFunc && (xFinal || xStep)) ||
1538       (!xFunc && (xFinal && !xStep)) ||
1539       (!xFunc && (!xFinal && xStep)) ||
1540       (nArg<-1 || nArg>SQLITE_MAX_FUNCTION_ARG) ||
1541       (255<(nName = sqlite3Strlen30( zFunctionName))) ){
1542     return SQLITE_MISUSE_BKPT;
1543   }
1544 
1545   assert( SQLITE_FUNC_CONSTANT==SQLITE_DETERMINISTIC );
1546   extraFlags = enc &  SQLITE_DETERMINISTIC;
1547   enc &= (SQLITE_FUNC_ENCMASK|SQLITE_ANY);
1548 
1549 #ifndef SQLITE_OMIT_UTF16
1550   /* If SQLITE_UTF16 is specified as the encoding type, transform this
1551   ** to one of SQLITE_UTF16LE or SQLITE_UTF16BE using the
1552   ** SQLITE_UTF16NATIVE macro. SQLITE_UTF16 is not used internally.
1553   **
1554   ** If SQLITE_ANY is specified, add three versions of the function
1555   ** to the hash table.
1556   */
1557   if( enc==SQLITE_UTF16 ){
1558     enc = SQLITE_UTF16NATIVE;
1559   }else if( enc==SQLITE_ANY ){
1560     int rc;
1561     rc = sqlite3CreateFunc(db, zFunctionName, nArg, SQLITE_UTF8|extraFlags,
1562          pUserData, xFunc, xStep, xFinal, pDestructor);
1563     if( rc==SQLITE_OK ){
1564       rc = sqlite3CreateFunc(db, zFunctionName, nArg, SQLITE_UTF16LE|extraFlags,
1565           pUserData, xFunc, xStep, xFinal, pDestructor);
1566     }
1567     if( rc!=SQLITE_OK ){
1568       return rc;
1569     }
1570     enc = SQLITE_UTF16BE;
1571   }
1572 #else
1573   enc = SQLITE_UTF8;
1574 #endif
1575 
1576   /* Check if an existing function is being overridden or deleted. If so,
1577   ** and there are active VMs, then return SQLITE_BUSY. If a function
1578   ** is being overridden/deleted but there are no active VMs, allow the
1579   ** operation to continue but invalidate all precompiled statements.
1580   */
1581   p = sqlite3FindFunction(db, zFunctionName, nName, nArg, (u8)enc, 0);
1582   if( p && (p->funcFlags & SQLITE_FUNC_ENCMASK)==enc && p->nArg==nArg ){
1583     if( db->nVdbeActive ){
1584       sqlite3ErrorWithMsg(db, SQLITE_BUSY,
1585         "unable to delete/modify user-function due to active statements");
1586       assert( !db->mallocFailed );
1587       return SQLITE_BUSY;
1588     }else{
1589       sqlite3ExpirePreparedStatements(db);
1590     }
1591   }
1592 
1593   p = sqlite3FindFunction(db, zFunctionName, nName, nArg, (u8)enc, 1);
1594   assert(p || db->mallocFailed);
1595   if( !p ){
1596     return SQLITE_NOMEM;
1597   }
1598 
1599   /* If an older version of the function with a configured destructor is
1600   ** being replaced invoke the destructor function here. */
1601   functionDestroy(db, p);
1602 
1603   if( pDestructor ){
1604     pDestructor->nRef++;
1605   }
1606   p->pDestructor = pDestructor;
1607   p->funcFlags = (p->funcFlags & SQLITE_FUNC_ENCMASK) | extraFlags;
1608   testcase( p->funcFlags & SQLITE_DETERMINISTIC );
1609   p->xFunc = xFunc;
1610   p->xStep = xStep;
1611   p->xFinalize = xFinal;
1612   p->pUserData = pUserData;
1613   p->nArg = (u16)nArg;
1614   return SQLITE_OK;
1615 }
1616 
1617 /*
1618 ** Create new user functions.
1619 */
1620 int sqlite3_create_function(
1621   sqlite3 *db,
1622   const char *zFunc,
1623   int nArg,
1624   int enc,
1625   void *p,
1626   void (*xFunc)(sqlite3_context*,int,sqlite3_value **),
1627   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
1628   void (*xFinal)(sqlite3_context*)
1629 ){
1630   return sqlite3_create_function_v2(db, zFunc, nArg, enc, p, xFunc, xStep,
1631                                     xFinal, 0);
1632 }
1633 
1634 int sqlite3_create_function_v2(
1635   sqlite3 *db,
1636   const char *zFunc,
1637   int nArg,
1638   int enc,
1639   void *p,
1640   void (*xFunc)(sqlite3_context*,int,sqlite3_value **),
1641   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
1642   void (*xFinal)(sqlite3_context*),
1643   void (*xDestroy)(void *)
1644 ){
1645   int rc = SQLITE_ERROR;
1646   FuncDestructor *pArg = 0;
1647 
1648 #ifdef SQLITE_ENABLE_API_ARMOR
1649   if( !sqlite3SafetyCheckOk(db) ){
1650     return SQLITE_MISUSE_BKPT;
1651   }
1652 #endif
1653   sqlite3_mutex_enter(db->mutex);
1654   if( xDestroy ){
1655     pArg = (FuncDestructor *)sqlite3DbMallocZero(db, sizeof(FuncDestructor));
1656     if( !pArg ){
1657       xDestroy(p);
1658       goto out;
1659     }
1660     pArg->xDestroy = xDestroy;
1661     pArg->pUserData = p;
1662   }
1663   rc = sqlite3CreateFunc(db, zFunc, nArg, enc, p, xFunc, xStep, xFinal, pArg);
1664   if( pArg && pArg->nRef==0 ){
1665     assert( rc!=SQLITE_OK );
1666     xDestroy(p);
1667     sqlite3DbFree(db, pArg);
1668   }
1669 
1670  out:
1671   rc = sqlite3ApiExit(db, rc);
1672   sqlite3_mutex_leave(db->mutex);
1673   return rc;
1674 }
1675 
1676 #ifndef SQLITE_OMIT_UTF16
1677 int sqlite3_create_function16(
1678   sqlite3 *db,
1679   const void *zFunctionName,
1680   int nArg,
1681   int eTextRep,
1682   void *p,
1683   void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
1684   void (*xStep)(sqlite3_context*,int,sqlite3_value**),
1685   void (*xFinal)(sqlite3_context*)
1686 ){
1687   int rc;
1688   char *zFunc8;
1689 
1690 #ifdef SQLITE_ENABLE_API_ARMOR
1691   if( !sqlite3SafetyCheckOk(db) || zFunctionName==0 ) return SQLITE_MISUSE_BKPT;
1692 #endif
1693   sqlite3_mutex_enter(db->mutex);
1694   assert( !db->mallocFailed );
1695   zFunc8 = sqlite3Utf16to8(db, zFunctionName, -1, SQLITE_UTF16NATIVE);
1696   rc = sqlite3CreateFunc(db, zFunc8, nArg, eTextRep, p, xFunc, xStep, xFinal,0);
1697   sqlite3DbFree(db, zFunc8);
1698   rc = sqlite3ApiExit(db, rc);
1699   sqlite3_mutex_leave(db->mutex);
1700   return rc;
1701 }
1702 #endif
1703 
1704 
1705 /*
1706 ** Declare that a function has been overloaded by a virtual table.
1707 **
1708 ** If the function already exists as a regular global function, then
1709 ** this routine is a no-op.  If the function does not exist, then create
1710 ** a new one that always throws a run-time error.
1711 **
1712 ** When virtual tables intend to provide an overloaded function, they
1713 ** should call this routine to make sure the global function exists.
1714 ** A global function must exist in order for name resolution to work
1715 ** properly.
1716 */
1717 int sqlite3_overload_function(
1718   sqlite3 *db,
1719   const char *zName,
1720   int nArg
1721 ){
1722   int nName = sqlite3Strlen30(zName);
1723   int rc = SQLITE_OK;
1724 
1725 #ifdef SQLITE_ENABLE_API_ARMOR
1726   if( !sqlite3SafetyCheckOk(db) || zName==0 || nArg<-2 ){
1727     return SQLITE_MISUSE_BKPT;
1728   }
1729 #endif
1730   sqlite3_mutex_enter(db->mutex);
1731   if( sqlite3FindFunction(db, zName, nName, nArg, SQLITE_UTF8, 0)==0 ){
1732     rc = sqlite3CreateFunc(db, zName, nArg, SQLITE_UTF8,
1733                            0, sqlite3InvalidFunction, 0, 0, 0);
1734   }
1735   rc = sqlite3ApiExit(db, rc);
1736   sqlite3_mutex_leave(db->mutex);
1737   return rc;
1738 }
1739 
1740 #ifndef SQLITE_OMIT_TRACE
1741 /*
1742 ** Register a trace function.  The pArg from the previously registered trace
1743 ** is returned.
1744 **
1745 ** A NULL trace function means that no tracing is executes.  A non-NULL
1746 ** trace is a pointer to a function that is invoked at the start of each
1747 ** SQL statement.
1748 */
1749 void *sqlite3_trace(sqlite3 *db, void (*xTrace)(void*,const char*), void *pArg){
1750   void *pOld;
1751 
1752 #ifdef SQLITE_ENABLE_API_ARMOR
1753   if( !sqlite3SafetyCheckOk(db) ){
1754     (void)SQLITE_MISUSE_BKPT;
1755     return 0;
1756   }
1757 #endif
1758   sqlite3_mutex_enter(db->mutex);
1759   pOld = db->pTraceArg;
1760   db->xTrace = xTrace;
1761   db->pTraceArg = pArg;
1762   sqlite3_mutex_leave(db->mutex);
1763   return pOld;
1764 }
1765 /*
1766 ** Register a profile function.  The pArg from the previously registered
1767 ** profile function is returned.
1768 **
1769 ** A NULL profile function means that no profiling is executes.  A non-NULL
1770 ** profile is a pointer to a function that is invoked at the conclusion of
1771 ** each SQL statement that is run.
1772 */
1773 void *sqlite3_profile(
1774   sqlite3 *db,
1775   void (*xProfile)(void*,const char*,sqlite_uint64),
1776   void *pArg
1777 ){
1778   void *pOld;
1779 
1780 #ifdef SQLITE_ENABLE_API_ARMOR
1781   if( !sqlite3SafetyCheckOk(db) ){
1782     (void)SQLITE_MISUSE_BKPT;
1783     return 0;
1784   }
1785 #endif
1786   sqlite3_mutex_enter(db->mutex);
1787   pOld = db->pProfileArg;
1788   db->xProfile = xProfile;
1789   db->pProfileArg = pArg;
1790   sqlite3_mutex_leave(db->mutex);
1791   return pOld;
1792 }
1793 #endif /* SQLITE_OMIT_TRACE */
1794 
1795 /*
1796 ** Register a function to be invoked when a transaction commits.
1797 ** If the invoked function returns non-zero, then the commit becomes a
1798 ** rollback.
1799 */
1800 void *sqlite3_commit_hook(
1801   sqlite3 *db,              /* Attach the hook to this database */
1802   int (*xCallback)(void*),  /* Function to invoke on each commit */
1803   void *pArg                /* Argument to the function */
1804 ){
1805   void *pOld;
1806 
1807 #ifdef SQLITE_ENABLE_API_ARMOR
1808   if( !sqlite3SafetyCheckOk(db) ){
1809     (void)SQLITE_MISUSE_BKPT;
1810     return 0;
1811   }
1812 #endif
1813   sqlite3_mutex_enter(db->mutex);
1814   pOld = db->pCommitArg;
1815   db->xCommitCallback = xCallback;
1816   db->pCommitArg = pArg;
1817   sqlite3_mutex_leave(db->mutex);
1818   return pOld;
1819 }
1820 
1821 /*
1822 ** Register a callback to be invoked each time a row is updated,
1823 ** inserted or deleted using this database connection.
1824 */
1825 void *sqlite3_update_hook(
1826   sqlite3 *db,              /* Attach the hook to this database */
1827   void (*xCallback)(void*,int,char const *,char const *,sqlite_int64),
1828   void *pArg                /* Argument to the function */
1829 ){
1830   void *pRet;
1831 
1832 #ifdef SQLITE_ENABLE_API_ARMOR
1833   if( !sqlite3SafetyCheckOk(db) ){
1834     (void)SQLITE_MISUSE_BKPT;
1835     return 0;
1836   }
1837 #endif
1838   sqlite3_mutex_enter(db->mutex);
1839   pRet = db->pUpdateArg;
1840   db->xUpdateCallback = xCallback;
1841   db->pUpdateArg = pArg;
1842   sqlite3_mutex_leave(db->mutex);
1843   return pRet;
1844 }
1845 
1846 /*
1847 ** Register a callback to be invoked each time a transaction is rolled
1848 ** back by this database connection.
1849 */
1850 void *sqlite3_rollback_hook(
1851   sqlite3 *db,              /* Attach the hook to this database */
1852   void (*xCallback)(void*), /* Callback function */
1853   void *pArg                /* Argument to the function */
1854 ){
1855   void *pRet;
1856 
1857 #ifdef SQLITE_ENABLE_API_ARMOR
1858   if( !sqlite3SafetyCheckOk(db) ){
1859     (void)SQLITE_MISUSE_BKPT;
1860     return 0;
1861   }
1862 #endif
1863   sqlite3_mutex_enter(db->mutex);
1864   pRet = db->pRollbackArg;
1865   db->xRollbackCallback = xCallback;
1866   db->pRollbackArg = pArg;
1867   sqlite3_mutex_leave(db->mutex);
1868   return pRet;
1869 }
1870 
1871 #ifndef SQLITE_OMIT_WAL
1872 /*
1873 ** The sqlite3_wal_hook() callback registered by sqlite3_wal_autocheckpoint().
1874 ** Invoke sqlite3_wal_checkpoint if the number of frames in the log file
1875 ** is greater than sqlite3.pWalArg cast to an integer (the value configured by
1876 ** wal_autocheckpoint()).
1877 */
1878 int sqlite3WalDefaultHook(
1879   void *pClientData,     /* Argument */
1880   sqlite3 *db,           /* Connection */
1881   const char *zDb,       /* Database */
1882   int nFrame             /* Size of WAL */
1883 ){
1884   if( nFrame>=SQLITE_PTR_TO_INT(pClientData) ){
1885     sqlite3BeginBenignMalloc();
1886     sqlite3_wal_checkpoint(db, zDb);
1887     sqlite3EndBenignMalloc();
1888   }
1889   return SQLITE_OK;
1890 }
1891 #endif /* SQLITE_OMIT_WAL */
1892 
1893 /*
1894 ** Configure an sqlite3_wal_hook() callback to automatically checkpoint
1895 ** a database after committing a transaction if there are nFrame or
1896 ** more frames in the log file. Passing zero or a negative value as the
1897 ** nFrame parameter disables automatic checkpoints entirely.
1898 **
1899 ** The callback registered by this function replaces any existing callback
1900 ** registered using sqlite3_wal_hook(). Likewise, registering a callback
1901 ** using sqlite3_wal_hook() disables the automatic checkpoint mechanism
1902 ** configured by this function.
1903 */
1904 int sqlite3_wal_autocheckpoint(sqlite3 *db, int nFrame){
1905 #ifdef SQLITE_OMIT_WAL
1906   UNUSED_PARAMETER(db);
1907   UNUSED_PARAMETER(nFrame);
1908 #else
1909 #ifdef SQLITE_ENABLE_API_ARMOR
1910   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
1911 #endif
1912   if( nFrame>0 ){
1913     sqlite3_wal_hook(db, sqlite3WalDefaultHook, SQLITE_INT_TO_PTR(nFrame));
1914   }else{
1915     sqlite3_wal_hook(db, 0, 0);
1916   }
1917 #endif
1918   return SQLITE_OK;
1919 }
1920 
1921 /*
1922 ** Register a callback to be invoked each time a transaction is written
1923 ** into the write-ahead-log by this database connection.
1924 */
1925 void *sqlite3_wal_hook(
1926   sqlite3 *db,                    /* Attach the hook to this db handle */
1927   int(*xCallback)(void *, sqlite3*, const char*, int),
1928   void *pArg                      /* First argument passed to xCallback() */
1929 ){
1930 #ifndef SQLITE_OMIT_WAL
1931   void *pRet;
1932 #ifdef SQLITE_ENABLE_API_ARMOR
1933   if( !sqlite3SafetyCheckOk(db) ){
1934     (void)SQLITE_MISUSE_BKPT;
1935     return 0;
1936   }
1937 #endif
1938   sqlite3_mutex_enter(db->mutex);
1939   pRet = db->pWalArg;
1940   db->xWalCallback = xCallback;
1941   db->pWalArg = pArg;
1942   sqlite3_mutex_leave(db->mutex);
1943   return pRet;
1944 #else
1945   return 0;
1946 #endif
1947 }
1948 
1949 /*
1950 ** Checkpoint database zDb.
1951 */
1952 int sqlite3_wal_checkpoint_v2(
1953   sqlite3 *db,                    /* Database handle */
1954   const char *zDb,                /* Name of attached database (or NULL) */
1955   int eMode,                      /* SQLITE_CHECKPOINT_* value */
1956   int *pnLog,                     /* OUT: Size of WAL log in frames */
1957   int *pnCkpt                     /* OUT: Total number of frames checkpointed */
1958 ){
1959 #ifdef SQLITE_OMIT_WAL
1960   return SQLITE_OK;
1961 #else
1962   int rc;                         /* Return code */
1963   int iDb = SQLITE_MAX_ATTACHED;  /* sqlite3.aDb[] index of db to checkpoint */
1964 
1965 #ifdef SQLITE_ENABLE_API_ARMOR
1966   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
1967 #endif
1968 
1969   /* Initialize the output variables to -1 in case an error occurs. */
1970   if( pnLog ) *pnLog = -1;
1971   if( pnCkpt ) *pnCkpt = -1;
1972 
1973   assert( SQLITE_CHECKPOINT_PASSIVE==0 );
1974   assert( SQLITE_CHECKPOINT_FULL==1 );
1975   assert( SQLITE_CHECKPOINT_RESTART==2 );
1976   assert( SQLITE_CHECKPOINT_TRUNCATE==3 );
1977   if( eMode<SQLITE_CHECKPOINT_PASSIVE || eMode>SQLITE_CHECKPOINT_TRUNCATE ){
1978     /* EVIDENCE-OF: R-03996-12088 The M parameter must be a valid checkpoint
1979     ** mode: */
1980     return SQLITE_MISUSE;
1981   }
1982 
1983   sqlite3_mutex_enter(db->mutex);
1984   if( zDb && zDb[0] ){
1985     iDb = sqlite3FindDbName(db, zDb);
1986   }
1987   if( iDb<0 ){
1988     rc = SQLITE_ERROR;
1989     sqlite3ErrorWithMsg(db, SQLITE_ERROR, "unknown database: %s", zDb);
1990   }else{
1991     db->busyHandler.nBusy = 0;
1992     rc = sqlite3Checkpoint(db, iDb, eMode, pnLog, pnCkpt);
1993     sqlite3Error(db, rc);
1994   }
1995   rc = sqlite3ApiExit(db, rc);
1996   sqlite3_mutex_leave(db->mutex);
1997   return rc;
1998 #endif
1999 }
2000 
2001 
2002 /*
2003 ** Checkpoint database zDb. If zDb is NULL, or if the buffer zDb points
2004 ** to contains a zero-length string, all attached databases are
2005 ** checkpointed.
2006 */
2007 int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb){
2008   /* EVIDENCE-OF: R-41613-20553 The sqlite3_wal_checkpoint(D,X) is equivalent to
2009   ** sqlite3_wal_checkpoint_v2(D,X,SQLITE_CHECKPOINT_PASSIVE,0,0). */
2010   return sqlite3_wal_checkpoint_v2(db,zDb,SQLITE_CHECKPOINT_PASSIVE,0,0);
2011 }
2012 
2013 #ifndef SQLITE_OMIT_WAL
2014 /*
2015 ** Run a checkpoint on database iDb. This is a no-op if database iDb is
2016 ** not currently open in WAL mode.
2017 **
2018 ** If a transaction is open on the database being checkpointed, this
2019 ** function returns SQLITE_LOCKED and a checkpoint is not attempted. If
2020 ** an error occurs while running the checkpoint, an SQLite error code is
2021 ** returned (i.e. SQLITE_IOERR). Otherwise, SQLITE_OK.
2022 **
2023 ** The mutex on database handle db should be held by the caller. The mutex
2024 ** associated with the specific b-tree being checkpointed is taken by
2025 ** this function while the checkpoint is running.
2026 **
2027 ** If iDb is passed SQLITE_MAX_ATTACHED, then all attached databases are
2028 ** checkpointed. If an error is encountered it is returned immediately -
2029 ** no attempt is made to checkpoint any remaining databases.
2030 **
2031 ** Parameter eMode is one of SQLITE_CHECKPOINT_PASSIVE, FULL or RESTART.
2032 */
2033 int sqlite3Checkpoint(sqlite3 *db, int iDb, int eMode, int *pnLog, int *pnCkpt){
2034   int rc = SQLITE_OK;             /* Return code */
2035   int i;                          /* Used to iterate through attached dbs */
2036   int bBusy = 0;                  /* True if SQLITE_BUSY has been encountered */
2037 
2038   assert( sqlite3_mutex_held(db->mutex) );
2039   assert( !pnLog || *pnLog==-1 );
2040   assert( !pnCkpt || *pnCkpt==-1 );
2041 
2042   for(i=0; i<db->nDb && rc==SQLITE_OK; i++){
2043     if( i==iDb || iDb==SQLITE_MAX_ATTACHED ){
2044       rc = sqlite3BtreeCheckpoint(db->aDb[i].pBt, eMode, pnLog, pnCkpt);
2045       pnLog = 0;
2046       pnCkpt = 0;
2047       if( rc==SQLITE_BUSY ){
2048         bBusy = 1;
2049         rc = SQLITE_OK;
2050       }
2051     }
2052   }
2053 
2054   return (rc==SQLITE_OK && bBusy) ? SQLITE_BUSY : rc;
2055 }
2056 #endif /* SQLITE_OMIT_WAL */
2057 
2058 /*
2059 ** This function returns true if main-memory should be used instead of
2060 ** a temporary file for transient pager files and statement journals.
2061 ** The value returned depends on the value of db->temp_store (runtime
2062 ** parameter) and the compile time value of SQLITE_TEMP_STORE. The
2063 ** following table describes the relationship between these two values
2064 ** and this functions return value.
2065 **
2066 **   SQLITE_TEMP_STORE     db->temp_store     Location of temporary database
2067 **   -----------------     --------------     ------------------------------
2068 **   0                     any                file      (return 0)
2069 **   1                     1                  file      (return 0)
2070 **   1                     2                  memory    (return 1)
2071 **   1                     0                  file      (return 0)
2072 **   2                     1                  file      (return 0)
2073 **   2                     2                  memory    (return 1)
2074 **   2                     0                  memory    (return 1)
2075 **   3                     any                memory    (return 1)
2076 */
2077 int sqlite3TempInMemory(const sqlite3 *db){
2078 #if SQLITE_TEMP_STORE==1
2079   return ( db->temp_store==2 );
2080 #endif
2081 #if SQLITE_TEMP_STORE==2
2082   return ( db->temp_store!=1 );
2083 #endif
2084 #if SQLITE_TEMP_STORE==3
2085   UNUSED_PARAMETER(db);
2086   return 1;
2087 #endif
2088 #if SQLITE_TEMP_STORE<1 || SQLITE_TEMP_STORE>3
2089   UNUSED_PARAMETER(db);
2090   return 0;
2091 #endif
2092 }
2093 
2094 /*
2095 ** Return UTF-8 encoded English language explanation of the most recent
2096 ** error.
2097 */
2098 const char *sqlite3_errmsg(sqlite3 *db){
2099   const char *z;
2100   if( !db ){
2101     return sqlite3ErrStr(SQLITE_NOMEM);
2102   }
2103   if( !sqlite3SafetyCheckSickOrOk(db) ){
2104     return sqlite3ErrStr(SQLITE_MISUSE_BKPT);
2105   }
2106   sqlite3_mutex_enter(db->mutex);
2107   if( db->mallocFailed ){
2108     z = sqlite3ErrStr(SQLITE_NOMEM);
2109   }else{
2110     testcase( db->pErr==0 );
2111     z = (char*)sqlite3_value_text(db->pErr);
2112     assert( !db->mallocFailed );
2113     if( z==0 ){
2114       z = sqlite3ErrStr(db->errCode);
2115     }
2116   }
2117   sqlite3_mutex_leave(db->mutex);
2118   return z;
2119 }
2120 
2121 #ifndef SQLITE_OMIT_UTF16
2122 /*
2123 ** Return UTF-16 encoded English language explanation of the most recent
2124 ** error.
2125 */
2126 const void *sqlite3_errmsg16(sqlite3 *db){
2127   static const u16 outOfMem[] = {
2128     'o', 'u', 't', ' ', 'o', 'f', ' ', 'm', 'e', 'm', 'o', 'r', 'y', 0
2129   };
2130   static const u16 misuse[] = {
2131     'l', 'i', 'b', 'r', 'a', 'r', 'y', ' ',
2132     'r', 'o', 'u', 't', 'i', 'n', 'e', ' ',
2133     'c', 'a', 'l', 'l', 'e', 'd', ' ',
2134     'o', 'u', 't', ' ',
2135     'o', 'f', ' ',
2136     's', 'e', 'q', 'u', 'e', 'n', 'c', 'e', 0
2137   };
2138 
2139   const void *z;
2140   if( !db ){
2141     return (void *)outOfMem;
2142   }
2143   if( !sqlite3SafetyCheckSickOrOk(db) ){
2144     return (void *)misuse;
2145   }
2146   sqlite3_mutex_enter(db->mutex);
2147   if( db->mallocFailed ){
2148     z = (void *)outOfMem;
2149   }else{
2150     z = sqlite3_value_text16(db->pErr);
2151     if( z==0 ){
2152       sqlite3ErrorWithMsg(db, db->errCode, sqlite3ErrStr(db->errCode));
2153       z = sqlite3_value_text16(db->pErr);
2154     }
2155     /* A malloc() may have failed within the call to sqlite3_value_text16()
2156     ** above. If this is the case, then the db->mallocFailed flag needs to
2157     ** be cleared before returning. Do this directly, instead of via
2158     ** sqlite3ApiExit(), to avoid setting the database handle error message.
2159     */
2160     db->mallocFailed = 0;
2161   }
2162   sqlite3_mutex_leave(db->mutex);
2163   return z;
2164 }
2165 #endif /* SQLITE_OMIT_UTF16 */
2166 
2167 /*
2168 ** Return the most recent error code generated by an SQLite routine. If NULL is
2169 ** passed to this function, we assume a malloc() failed during sqlite3_open().
2170 */
2171 int sqlite3_errcode(sqlite3 *db){
2172   if( db && !sqlite3SafetyCheckSickOrOk(db) ){
2173     return SQLITE_MISUSE_BKPT;
2174   }
2175   if( !db || db->mallocFailed ){
2176     return SQLITE_NOMEM;
2177   }
2178   return db->errCode & db->errMask;
2179 }
2180 int sqlite3_extended_errcode(sqlite3 *db){
2181   if( db && !sqlite3SafetyCheckSickOrOk(db) ){
2182     return SQLITE_MISUSE_BKPT;
2183   }
2184   if( !db || db->mallocFailed ){
2185     return SQLITE_NOMEM;
2186   }
2187   return db->errCode;
2188 }
2189 
2190 /*
2191 ** Return a string that describes the kind of error specified in the
2192 ** argument.  For now, this simply calls the internal sqlite3ErrStr()
2193 ** function.
2194 */
2195 const char *sqlite3_errstr(int rc){
2196   return sqlite3ErrStr(rc);
2197 }
2198 
2199 /*
2200 ** Create a new collating function for database "db".  The name is zName
2201 ** and the encoding is enc.
2202 */
2203 static int createCollation(
2204   sqlite3* db,
2205   const char *zName,
2206   u8 enc,
2207   void* pCtx,
2208   int(*xCompare)(void*,int,const void*,int,const void*),
2209   void(*xDel)(void*)
2210 ){
2211   CollSeq *pColl;
2212   int enc2;
2213 
2214   assert( sqlite3_mutex_held(db->mutex) );
2215 
2216   /* If SQLITE_UTF16 is specified as the encoding type, transform this
2217   ** to one of SQLITE_UTF16LE or SQLITE_UTF16BE using the
2218   ** SQLITE_UTF16NATIVE macro. SQLITE_UTF16 is not used internally.
2219   */
2220   enc2 = enc;
2221   testcase( enc2==SQLITE_UTF16 );
2222   testcase( enc2==SQLITE_UTF16_ALIGNED );
2223   if( enc2==SQLITE_UTF16 || enc2==SQLITE_UTF16_ALIGNED ){
2224     enc2 = SQLITE_UTF16NATIVE;
2225   }
2226   if( enc2<SQLITE_UTF8 || enc2>SQLITE_UTF16BE ){
2227     return SQLITE_MISUSE_BKPT;
2228   }
2229 
2230   /* Check if this call is removing or replacing an existing collation
2231   ** sequence. If so, and there are active VMs, return busy. If there
2232   ** are no active VMs, invalidate any pre-compiled statements.
2233   */
2234   pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, 0);
2235   if( pColl && pColl->xCmp ){
2236     if( db->nVdbeActive ){
2237       sqlite3ErrorWithMsg(db, SQLITE_BUSY,
2238         "unable to delete/modify collation sequence due to active statements");
2239       return SQLITE_BUSY;
2240     }
2241     sqlite3ExpirePreparedStatements(db);
2242 
2243     /* If collation sequence pColl was created directly by a call to
2244     ** sqlite3_create_collation, and not generated by synthCollSeq(),
2245     ** then any copies made by synthCollSeq() need to be invalidated.
2246     ** Also, collation destructor - CollSeq.xDel() - function may need
2247     ** to be called.
2248     */
2249     if( (pColl->enc & ~SQLITE_UTF16_ALIGNED)==enc2 ){
2250       CollSeq *aColl = sqlite3HashFind(&db->aCollSeq, zName);
2251       int j;
2252       for(j=0; j<3; j++){
2253         CollSeq *p = &aColl[j];
2254         if( p->enc==pColl->enc ){
2255           if( p->xDel ){
2256             p->xDel(p->pUser);
2257           }
2258           p->xCmp = 0;
2259         }
2260       }
2261     }
2262   }
2263 
2264   pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, 1);
2265   if( pColl==0 ) return SQLITE_NOMEM;
2266   pColl->xCmp = xCompare;
2267   pColl->pUser = pCtx;
2268   pColl->xDel = xDel;
2269   pColl->enc = (u8)(enc2 | (enc & SQLITE_UTF16_ALIGNED));
2270   sqlite3Error(db, SQLITE_OK);
2271   return SQLITE_OK;
2272 }
2273 
2274 
2275 /*
2276 ** This array defines hard upper bounds on limit values.  The
2277 ** initializer must be kept in sync with the SQLITE_LIMIT_*
2278 ** #defines in sqlite3.h.
2279 */
2280 static const int aHardLimit[] = {
2281   SQLITE_MAX_LENGTH,
2282   SQLITE_MAX_SQL_LENGTH,
2283   SQLITE_MAX_COLUMN,
2284   SQLITE_MAX_EXPR_DEPTH,
2285   SQLITE_MAX_COMPOUND_SELECT,
2286   SQLITE_MAX_VDBE_OP,
2287   SQLITE_MAX_FUNCTION_ARG,
2288   SQLITE_MAX_ATTACHED,
2289   SQLITE_MAX_LIKE_PATTERN_LENGTH,
2290   SQLITE_MAX_VARIABLE_NUMBER,      /* IMP: R-38091-32352 */
2291   SQLITE_MAX_TRIGGER_DEPTH,
2292   SQLITE_MAX_WORKER_THREADS,
2293 };
2294 
2295 /*
2296 ** Make sure the hard limits are set to reasonable values
2297 */
2298 #if SQLITE_MAX_LENGTH<100
2299 # error SQLITE_MAX_LENGTH must be at least 100
2300 #endif
2301 #if SQLITE_MAX_SQL_LENGTH<100
2302 # error SQLITE_MAX_SQL_LENGTH must be at least 100
2303 #endif
2304 #if SQLITE_MAX_SQL_LENGTH>SQLITE_MAX_LENGTH
2305 # error SQLITE_MAX_SQL_LENGTH must not be greater than SQLITE_MAX_LENGTH
2306 #endif
2307 #if SQLITE_MAX_COMPOUND_SELECT<2
2308 # error SQLITE_MAX_COMPOUND_SELECT must be at least 2
2309 #endif
2310 #if SQLITE_MAX_VDBE_OP<40
2311 # error SQLITE_MAX_VDBE_OP must be at least 40
2312 #endif
2313 #if SQLITE_MAX_FUNCTION_ARG<0 || SQLITE_MAX_FUNCTION_ARG>1000
2314 # error SQLITE_MAX_FUNCTION_ARG must be between 0 and 1000
2315 #endif
2316 #if SQLITE_MAX_ATTACHED<0 || SQLITE_MAX_ATTACHED>125
2317 # error SQLITE_MAX_ATTACHED must be between 0 and 125
2318 #endif
2319 #if SQLITE_MAX_LIKE_PATTERN_LENGTH<1
2320 # error SQLITE_MAX_LIKE_PATTERN_LENGTH must be at least 1
2321 #endif
2322 #if SQLITE_MAX_COLUMN>32767
2323 # error SQLITE_MAX_COLUMN must not exceed 32767
2324 #endif
2325 #if SQLITE_MAX_TRIGGER_DEPTH<1
2326 # error SQLITE_MAX_TRIGGER_DEPTH must be at least 1
2327 #endif
2328 #if SQLITE_MAX_WORKER_THREADS<0 || SQLITE_MAX_WORKER_THREADS>50
2329 # error SQLITE_MAX_WORKER_THREADS must be between 0 and 50
2330 #endif
2331 
2332 
2333 /*
2334 ** Change the value of a limit.  Report the old value.
2335 ** If an invalid limit index is supplied, report -1.
2336 ** Make no changes but still report the old value if the
2337 ** new limit is negative.
2338 **
2339 ** A new lower limit does not shrink existing constructs.
2340 ** It merely prevents new constructs that exceed the limit
2341 ** from forming.
2342 */
2343 int sqlite3_limit(sqlite3 *db, int limitId, int newLimit){
2344   int oldLimit;
2345 
2346 #ifdef SQLITE_ENABLE_API_ARMOR
2347   if( !sqlite3SafetyCheckOk(db) ){
2348     (void)SQLITE_MISUSE_BKPT;
2349     return -1;
2350   }
2351 #endif
2352 
2353   /* EVIDENCE-OF: R-30189-54097 For each limit category SQLITE_LIMIT_NAME
2354   ** there is a hard upper bound set at compile-time by a C preprocessor
2355   ** macro called SQLITE_MAX_NAME. (The "_LIMIT_" in the name is changed to
2356   ** "_MAX_".)
2357   */
2358   assert( aHardLimit[SQLITE_LIMIT_LENGTH]==SQLITE_MAX_LENGTH );
2359   assert( aHardLimit[SQLITE_LIMIT_SQL_LENGTH]==SQLITE_MAX_SQL_LENGTH );
2360   assert( aHardLimit[SQLITE_LIMIT_COLUMN]==SQLITE_MAX_COLUMN );
2361   assert( aHardLimit[SQLITE_LIMIT_EXPR_DEPTH]==SQLITE_MAX_EXPR_DEPTH );
2362   assert( aHardLimit[SQLITE_LIMIT_COMPOUND_SELECT]==SQLITE_MAX_COMPOUND_SELECT);
2363   assert( aHardLimit[SQLITE_LIMIT_VDBE_OP]==SQLITE_MAX_VDBE_OP );
2364   assert( aHardLimit[SQLITE_LIMIT_FUNCTION_ARG]==SQLITE_MAX_FUNCTION_ARG );
2365   assert( aHardLimit[SQLITE_LIMIT_ATTACHED]==SQLITE_MAX_ATTACHED );
2366   assert( aHardLimit[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]==
2367                                                SQLITE_MAX_LIKE_PATTERN_LENGTH );
2368   assert( aHardLimit[SQLITE_LIMIT_VARIABLE_NUMBER]==SQLITE_MAX_VARIABLE_NUMBER);
2369   assert( aHardLimit[SQLITE_LIMIT_TRIGGER_DEPTH]==SQLITE_MAX_TRIGGER_DEPTH );
2370   assert( aHardLimit[SQLITE_LIMIT_WORKER_THREADS]==SQLITE_MAX_WORKER_THREADS );
2371   assert( SQLITE_LIMIT_WORKER_THREADS==(SQLITE_N_LIMIT-1) );
2372 
2373 
2374   if( limitId<0 || limitId>=SQLITE_N_LIMIT ){
2375     return -1;
2376   }
2377   oldLimit = db->aLimit[limitId];
2378   if( newLimit>=0 ){                   /* IMP: R-52476-28732 */
2379     if( newLimit>aHardLimit[limitId] ){
2380       newLimit = aHardLimit[limitId];  /* IMP: R-51463-25634 */
2381     }
2382     db->aLimit[limitId] = newLimit;
2383   }
2384   return oldLimit;                     /* IMP: R-53341-35419 */
2385 }
2386 
2387 /*
2388 ** This function is used to parse both URIs and non-URI filenames passed by the
2389 ** user to API functions sqlite3_open() or sqlite3_open_v2(), and for database
2390 ** URIs specified as part of ATTACH statements.
2391 **
2392 ** The first argument to this function is the name of the VFS to use (or
2393 ** a NULL to signify the default VFS) if the URI does not contain a "vfs=xxx"
2394 ** query parameter. The second argument contains the URI (or non-URI filename)
2395 ** itself. When this function is called the *pFlags variable should contain
2396 ** the default flags to open the database handle with. The value stored in
2397 ** *pFlags may be updated before returning if the URI filename contains
2398 ** "cache=xxx" or "mode=xxx" query parameters.
2399 **
2400 ** If successful, SQLITE_OK is returned. In this case *ppVfs is set to point to
2401 ** the VFS that should be used to open the database file. *pzFile is set to
2402 ** point to a buffer containing the name of the file to open. It is the
2403 ** responsibility of the caller to eventually call sqlite3_free() to release
2404 ** this buffer.
2405 **
2406 ** If an error occurs, then an SQLite error code is returned and *pzErrMsg
2407 ** may be set to point to a buffer containing an English language error
2408 ** message. It is the responsibility of the caller to eventually release
2409 ** this buffer by calling sqlite3_free().
2410 */
2411 int sqlite3ParseUri(
2412   const char *zDefaultVfs,        /* VFS to use if no "vfs=xxx" query option */
2413   const char *zUri,               /* Nul-terminated URI to parse */
2414   unsigned int *pFlags,           /* IN/OUT: SQLITE_OPEN_XXX flags */
2415   sqlite3_vfs **ppVfs,            /* OUT: VFS to use */
2416   char **pzFile,                  /* OUT: Filename component of URI */
2417   char **pzErrMsg                 /* OUT: Error message (if rc!=SQLITE_OK) */
2418 ){
2419   int rc = SQLITE_OK;
2420   unsigned int flags = *pFlags;
2421   const char *zVfs = zDefaultVfs;
2422   char *zFile;
2423   char c;
2424   int nUri = sqlite3Strlen30(zUri);
2425 
2426   assert( *pzErrMsg==0 );
2427 
2428   if( ((flags & SQLITE_OPEN_URI)             /* IMP: R-48725-32206 */
2429             || sqlite3GlobalConfig.bOpenUri) /* IMP: R-51689-46548 */
2430    && nUri>=5 && memcmp(zUri, "file:", 5)==0 /* IMP: R-57884-37496 */
2431   ){
2432     char *zOpt;
2433     int eState;                   /* Parser state when parsing URI */
2434     int iIn;                      /* Input character index */
2435     int iOut = 0;                 /* Output character index */
2436     u64 nByte = nUri+2;           /* Bytes of space to allocate */
2437 
2438     /* Make sure the SQLITE_OPEN_URI flag is set to indicate to the VFS xOpen
2439     ** method that there may be extra parameters following the file-name.  */
2440     flags |= SQLITE_OPEN_URI;
2441 
2442     for(iIn=0; iIn<nUri; iIn++) nByte += (zUri[iIn]=='&');
2443     zFile = sqlite3_malloc64(nByte);
2444     if( !zFile ) return SQLITE_NOMEM;
2445 
2446     iIn = 5;
2447 #ifdef SQLITE_ALLOW_URI_AUTHORITY
2448     if( strncmp(zUri+5, "///", 3)==0 ){
2449       iIn = 7;
2450       /* The following condition causes URIs with five leading / characters
2451       ** like file://///host/path to be converted into UNCs like //host/path.
2452       ** The correct URI for that UNC has only two or four leading / characters
2453       ** file://host/path or file:////host/path.  But 5 leading slashes is a
2454       ** common error, we are told, so we handle it as a special case. */
2455       if( strncmp(zUri+7, "///", 3)==0 ){ iIn++; }
2456     }else if( strncmp(zUri+5, "//localhost/", 12)==0 ){
2457       iIn = 16;
2458     }
2459 #else
2460     /* Discard the scheme and authority segments of the URI. */
2461     if( zUri[5]=='/' && zUri[6]=='/' ){
2462       iIn = 7;
2463       while( zUri[iIn] && zUri[iIn]!='/' ) iIn++;
2464       if( iIn!=7 && (iIn!=16 || memcmp("localhost", &zUri[7], 9)) ){
2465         *pzErrMsg = sqlite3_mprintf("invalid uri authority: %.*s",
2466             iIn-7, &zUri[7]);
2467         rc = SQLITE_ERROR;
2468         goto parse_uri_out;
2469       }
2470     }
2471 #endif
2472 
2473     /* Copy the filename and any query parameters into the zFile buffer.
2474     ** Decode %HH escape codes along the way.
2475     **
2476     ** Within this loop, variable eState may be set to 0, 1 or 2, depending
2477     ** on the parsing context. As follows:
2478     **
2479     **   0: Parsing file-name.
2480     **   1: Parsing name section of a name=value query parameter.
2481     **   2: Parsing value section of a name=value query parameter.
2482     */
2483     eState = 0;
2484     while( (c = zUri[iIn])!=0 && c!='#' ){
2485       iIn++;
2486       if( c=='%'
2487        && sqlite3Isxdigit(zUri[iIn])
2488        && sqlite3Isxdigit(zUri[iIn+1])
2489       ){
2490         int octet = (sqlite3HexToInt(zUri[iIn++]) << 4);
2491         octet += sqlite3HexToInt(zUri[iIn++]);
2492 
2493         assert( octet>=0 && octet<256 );
2494         if( octet==0 ){
2495           /* This branch is taken when "%00" appears within the URI. In this
2496           ** case we ignore all text in the remainder of the path, name or
2497           ** value currently being parsed. So ignore the current character
2498           ** and skip to the next "?", "=" or "&", as appropriate. */
2499           while( (c = zUri[iIn])!=0 && c!='#'
2500               && (eState!=0 || c!='?')
2501               && (eState!=1 || (c!='=' && c!='&'))
2502               && (eState!=2 || c!='&')
2503           ){
2504             iIn++;
2505           }
2506           continue;
2507         }
2508         c = octet;
2509       }else if( eState==1 && (c=='&' || c=='=') ){
2510         if( zFile[iOut-1]==0 ){
2511           /* An empty option name. Ignore this option altogether. */
2512           while( zUri[iIn] && zUri[iIn]!='#' && zUri[iIn-1]!='&' ) iIn++;
2513           continue;
2514         }
2515         if( c=='&' ){
2516           zFile[iOut++] = '\0';
2517         }else{
2518           eState = 2;
2519         }
2520         c = 0;
2521       }else if( (eState==0 && c=='?') || (eState==2 && c=='&') ){
2522         c = 0;
2523         eState = 1;
2524       }
2525       zFile[iOut++] = c;
2526     }
2527     if( eState==1 ) zFile[iOut++] = '\0';
2528     zFile[iOut++] = '\0';
2529     zFile[iOut++] = '\0';
2530 
2531     /* Check if there were any options specified that should be interpreted
2532     ** here. Options that are interpreted here include "vfs" and those that
2533     ** correspond to flags that may be passed to the sqlite3_open_v2()
2534     ** method. */
2535     zOpt = &zFile[sqlite3Strlen30(zFile)+1];
2536     while( zOpt[0] ){
2537       int nOpt = sqlite3Strlen30(zOpt);
2538       char *zVal = &zOpt[nOpt+1];
2539       int nVal = sqlite3Strlen30(zVal);
2540 
2541       if( nOpt==3 && memcmp("vfs", zOpt, 3)==0 ){
2542         zVfs = zVal;
2543       }else{
2544         struct OpenMode {
2545           const char *z;
2546           int mode;
2547         } *aMode = 0;
2548         char *zModeType = 0;
2549         int mask = 0;
2550         int limit = 0;
2551 
2552         if( nOpt==5 && memcmp("cache", zOpt, 5)==0 ){
2553           static struct OpenMode aCacheMode[] = {
2554             { "shared",  SQLITE_OPEN_SHAREDCACHE },
2555             { "private", SQLITE_OPEN_PRIVATECACHE },
2556             { 0, 0 }
2557           };
2558 
2559           mask = SQLITE_OPEN_SHAREDCACHE|SQLITE_OPEN_PRIVATECACHE;
2560           aMode = aCacheMode;
2561           limit = mask;
2562           zModeType = "cache";
2563         }
2564         if( nOpt==4 && memcmp("mode", zOpt, 4)==0 ){
2565           static struct OpenMode aOpenMode[] = {
2566             { "ro",  SQLITE_OPEN_READONLY },
2567             { "rw",  SQLITE_OPEN_READWRITE },
2568             { "rwc", SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE },
2569             { "memory", SQLITE_OPEN_MEMORY },
2570             { 0, 0 }
2571           };
2572 
2573           mask = SQLITE_OPEN_READONLY | SQLITE_OPEN_READWRITE
2574                    | SQLITE_OPEN_CREATE | SQLITE_OPEN_MEMORY;
2575           aMode = aOpenMode;
2576           limit = mask & flags;
2577           zModeType = "access";
2578         }
2579 
2580         if( aMode ){
2581           int i;
2582           int mode = 0;
2583           for(i=0; aMode[i].z; i++){
2584             const char *z = aMode[i].z;
2585             if( nVal==sqlite3Strlen30(z) && 0==memcmp(zVal, z, nVal) ){
2586               mode = aMode[i].mode;
2587               break;
2588             }
2589           }
2590           if( mode==0 ){
2591             *pzErrMsg = sqlite3_mprintf("no such %s mode: %s", zModeType, zVal);
2592             rc = SQLITE_ERROR;
2593             goto parse_uri_out;
2594           }
2595           if( (mode & ~SQLITE_OPEN_MEMORY)>limit ){
2596             *pzErrMsg = sqlite3_mprintf("%s mode not allowed: %s",
2597                                         zModeType, zVal);
2598             rc = SQLITE_PERM;
2599             goto parse_uri_out;
2600           }
2601           flags = (flags & ~mask) | mode;
2602         }
2603       }
2604 
2605       zOpt = &zVal[nVal+1];
2606     }
2607 
2608   }else{
2609     zFile = sqlite3_malloc64(nUri+2);
2610     if( !zFile ) return SQLITE_NOMEM;
2611     memcpy(zFile, zUri, nUri);
2612     zFile[nUri] = '\0';
2613     zFile[nUri+1] = '\0';
2614     flags &= ~SQLITE_OPEN_URI;
2615   }
2616 
2617   *ppVfs = sqlite3_vfs_find(zVfs);
2618   if( *ppVfs==0 ){
2619     *pzErrMsg = sqlite3_mprintf("no such vfs: %s", zVfs);
2620     rc = SQLITE_ERROR;
2621   }
2622  parse_uri_out:
2623   if( rc!=SQLITE_OK ){
2624     sqlite3_free(zFile);
2625     zFile = 0;
2626   }
2627   *pFlags = flags;
2628   *pzFile = zFile;
2629   return rc;
2630 }
2631 
2632 
2633 /*
2634 ** This routine does the work of opening a database on behalf of
2635 ** sqlite3_open() and sqlite3_open16(). The database filename "zFilename"
2636 ** is UTF-8 encoded.
2637 */
2638 static int openDatabase(
2639   const char *zFilename, /* Database filename UTF-8 encoded */
2640   sqlite3 **ppDb,        /* OUT: Returned database handle */
2641   unsigned int flags,    /* Operational flags */
2642   const char *zVfs       /* Name of the VFS to use */
2643 ){
2644   sqlite3 *db;                    /* Store allocated handle here */
2645   int rc;                         /* Return code */
2646   int isThreadsafe;               /* True for threadsafe connections */
2647   char *zOpen = 0;                /* Filename argument to pass to BtreeOpen() */
2648   char *zErrMsg = 0;              /* Error message from sqlite3ParseUri() */
2649 
2650 #ifdef SQLITE_ENABLE_API_ARMOR
2651   if( ppDb==0 ) return SQLITE_MISUSE_BKPT;
2652 #endif
2653   *ppDb = 0;
2654 #ifndef SQLITE_OMIT_AUTOINIT
2655   rc = sqlite3_initialize();
2656   if( rc ) return rc;
2657 #endif
2658 
2659   /* Only allow sensible combinations of bits in the flags argument.
2660   ** Throw an error if any non-sense combination is used.  If we
2661   ** do not block illegal combinations here, it could trigger
2662   ** assert() statements in deeper layers.  Sensible combinations
2663   ** are:
2664   **
2665   **  1:  SQLITE_OPEN_READONLY
2666   **  2:  SQLITE_OPEN_READWRITE
2667   **  6:  SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE
2668   */
2669   assert( SQLITE_OPEN_READONLY  == 0x01 );
2670   assert( SQLITE_OPEN_READWRITE == 0x02 );
2671   assert( SQLITE_OPEN_CREATE    == 0x04 );
2672   testcase( (1<<(flags&7))==0x02 ); /* READONLY */
2673   testcase( (1<<(flags&7))==0x04 ); /* READWRITE */
2674   testcase( (1<<(flags&7))==0x40 ); /* READWRITE | CREATE */
2675   if( ((1<<(flags&7)) & 0x46)==0 ){
2676     return SQLITE_MISUSE_BKPT;  /* IMP: R-65497-44594 */
2677   }
2678 
2679   if( sqlite3GlobalConfig.bCoreMutex==0 ){
2680     isThreadsafe = 0;
2681   }else if( flags & SQLITE_OPEN_NOMUTEX ){
2682     isThreadsafe = 0;
2683   }else if( flags & SQLITE_OPEN_FULLMUTEX ){
2684     isThreadsafe = 1;
2685   }else{
2686     isThreadsafe = sqlite3GlobalConfig.bFullMutex;
2687   }
2688   if( flags & SQLITE_OPEN_PRIVATECACHE ){
2689     flags &= ~SQLITE_OPEN_SHAREDCACHE;
2690   }else if( sqlite3GlobalConfig.sharedCacheEnabled ){
2691     flags |= SQLITE_OPEN_SHAREDCACHE;
2692   }
2693 
2694   /* Remove harmful bits from the flags parameter
2695   **
2696   ** The SQLITE_OPEN_NOMUTEX and SQLITE_OPEN_FULLMUTEX flags were
2697   ** dealt with in the previous code block.  Besides these, the only
2698   ** valid input flags for sqlite3_open_v2() are SQLITE_OPEN_READONLY,
2699   ** SQLITE_OPEN_READWRITE, SQLITE_OPEN_CREATE, SQLITE_OPEN_SHAREDCACHE,
2700   ** SQLITE_OPEN_PRIVATECACHE, and some reserved bits.  Silently mask
2701   ** off all other flags.
2702   */
2703   flags &=  ~( SQLITE_OPEN_DELETEONCLOSE |
2704                SQLITE_OPEN_EXCLUSIVE |
2705                SQLITE_OPEN_MAIN_DB |
2706                SQLITE_OPEN_TEMP_DB |
2707                SQLITE_OPEN_TRANSIENT_DB |
2708                SQLITE_OPEN_MAIN_JOURNAL |
2709                SQLITE_OPEN_TEMP_JOURNAL |
2710                SQLITE_OPEN_SUBJOURNAL |
2711                SQLITE_OPEN_MASTER_JOURNAL |
2712                SQLITE_OPEN_NOMUTEX |
2713                SQLITE_OPEN_FULLMUTEX |
2714                SQLITE_OPEN_WAL
2715              );
2716 
2717   /* Allocate the sqlite data structure */
2718   db = sqlite3MallocZero( sizeof(sqlite3) );
2719   if( db==0 ) goto opendb_out;
2720   if( isThreadsafe ){
2721     db->mutex = sqlite3MutexAlloc(SQLITE_MUTEX_RECURSIVE);
2722     if( db->mutex==0 ){
2723       sqlite3_free(db);
2724       db = 0;
2725       goto opendb_out;
2726     }
2727   }
2728   sqlite3_mutex_enter(db->mutex);
2729   db->errMask = 0xff;
2730   db->nDb = 2;
2731   db->magic = SQLITE_MAGIC_BUSY;
2732   db->aDb = db->aDbStatic;
2733 
2734   assert( sizeof(db->aLimit)==sizeof(aHardLimit) );
2735   memcpy(db->aLimit, aHardLimit, sizeof(db->aLimit));
2736   db->aLimit[SQLITE_LIMIT_WORKER_THREADS] = SQLITE_DEFAULT_WORKER_THREADS;
2737   db->autoCommit = 1;
2738   db->nextAutovac = -1;
2739   db->szMmap = sqlite3GlobalConfig.szMmap;
2740   db->nextPagesize = 0;
2741   db->nMaxSorterMmap = 0x7FFFFFFF;
2742   db->flags |= SQLITE_ShortColNames | SQLITE_EnableTrigger | SQLITE_CacheSpill
2743 #if !defined(SQLITE_DEFAULT_AUTOMATIC_INDEX) || SQLITE_DEFAULT_AUTOMATIC_INDEX
2744                  | SQLITE_AutoIndex
2745 #endif
2746 #if SQLITE_DEFAULT_CKPTFULLFSYNC
2747                  | SQLITE_CkptFullFSync
2748 #endif
2749 #if SQLITE_DEFAULT_FILE_FORMAT<4
2750                  | SQLITE_LegacyFileFmt
2751 #endif
2752 #ifdef SQLITE_ENABLE_LOAD_EXTENSION
2753                  | SQLITE_LoadExtension
2754 #endif
2755 #if SQLITE_DEFAULT_RECURSIVE_TRIGGERS
2756                  | SQLITE_RecTriggers
2757 #endif
2758 #if defined(SQLITE_DEFAULT_FOREIGN_KEYS) && SQLITE_DEFAULT_FOREIGN_KEYS
2759                  | SQLITE_ForeignKeys
2760 #endif
2761 #if defined(SQLITE_REVERSE_UNORDERED_SELECTS)
2762                  | SQLITE_ReverseOrder
2763 #endif
2764 #if defined(SQLITE_ENABLE_OVERSIZE_CELL_CHECK)
2765                  | SQLITE_CellSizeCk
2766 #endif
2767       ;
2768   sqlite3HashInit(&db->aCollSeq);
2769 #ifndef SQLITE_OMIT_VIRTUALTABLE
2770   sqlite3HashInit(&db->aModule);
2771 #endif
2772 
2773   /* Add the default collation sequence BINARY. BINARY works for both UTF-8
2774   ** and UTF-16, so add a version for each to avoid any unnecessary
2775   ** conversions. The only error that can occur here is a malloc() failure.
2776   **
2777   ** EVIDENCE-OF: R-52786-44878 SQLite defines three built-in collating
2778   ** functions:
2779   */
2780   createCollation(db, "BINARY", SQLITE_UTF8, 0, binCollFunc, 0);
2781   createCollation(db, "BINARY", SQLITE_UTF16BE, 0, binCollFunc, 0);
2782   createCollation(db, "BINARY", SQLITE_UTF16LE, 0, binCollFunc, 0);
2783   createCollation(db, "NOCASE", SQLITE_UTF8, 0, nocaseCollatingFunc, 0);
2784   createCollation(db, "RTRIM", SQLITE_UTF8, (void*)1, binCollFunc, 0);
2785   if( db->mallocFailed ){
2786     goto opendb_out;
2787   }
2788   /* EVIDENCE-OF: R-08308-17224 The default collating function for all
2789   ** strings is BINARY.
2790   */
2791   db->pDfltColl = sqlite3FindCollSeq(db, SQLITE_UTF8, "BINARY", 0);
2792   assert( db->pDfltColl!=0 );
2793 
2794   /* Parse the filename/URI argument. */
2795   db->openFlags = flags;
2796   rc = sqlite3ParseUri(zVfs, zFilename, &flags, &db->pVfs, &zOpen, &zErrMsg);
2797   if( rc!=SQLITE_OK ){
2798     if( rc==SQLITE_NOMEM ) db->mallocFailed = 1;
2799     sqlite3ErrorWithMsg(db, rc, zErrMsg ? "%s" : 0, zErrMsg);
2800     sqlite3_free(zErrMsg);
2801     goto opendb_out;
2802   }
2803 
2804   /* Open the backend database driver */
2805   rc = sqlite3BtreeOpen(db->pVfs, zOpen, db, &db->aDb[0].pBt, 0,
2806                         flags | SQLITE_OPEN_MAIN_DB);
2807   if( rc!=SQLITE_OK ){
2808     if( rc==SQLITE_IOERR_NOMEM ){
2809       rc = SQLITE_NOMEM;
2810     }
2811     sqlite3Error(db, rc);
2812     goto opendb_out;
2813   }
2814   sqlite3BtreeEnter(db->aDb[0].pBt);
2815   db->aDb[0].pSchema = sqlite3SchemaGet(db, db->aDb[0].pBt);
2816   if( !db->mallocFailed ) ENC(db) = SCHEMA_ENC(db);
2817   sqlite3BtreeLeave(db->aDb[0].pBt);
2818   db->aDb[1].pSchema = sqlite3SchemaGet(db, 0);
2819 
2820   /* The default safety_level for the main database is 'full'; for the temp
2821   ** database it is 'NONE'. This matches the pager layer defaults.
2822   */
2823   db->aDb[0].zName = "main";
2824   db->aDb[0].safety_level = 3;
2825   db->aDb[1].zName = "temp";
2826   db->aDb[1].safety_level = 1;
2827 
2828   db->magic = SQLITE_MAGIC_OPEN;
2829   if( db->mallocFailed ){
2830     goto opendb_out;
2831   }
2832 
2833   /* Register all built-in functions, but do not attempt to read the
2834   ** database schema yet. This is delayed until the first time the database
2835   ** is accessed.
2836   */
2837   sqlite3Error(db, SQLITE_OK);
2838   sqlite3RegisterBuiltinFunctions(db);
2839 
2840   /* Load automatic extensions - extensions that have been registered
2841   ** using the sqlite3_automatic_extension() API.
2842   */
2843   rc = sqlite3_errcode(db);
2844   if( rc==SQLITE_OK ){
2845     sqlite3AutoLoadExtensions(db);
2846     rc = sqlite3_errcode(db);
2847     if( rc!=SQLITE_OK ){
2848       goto opendb_out;
2849     }
2850   }
2851 
2852 #ifdef SQLITE_ENABLE_FTS1
2853   if( !db->mallocFailed ){
2854     extern int sqlite3Fts1Init(sqlite3*);
2855     rc = sqlite3Fts1Init(db);
2856   }
2857 #endif
2858 
2859 #ifdef SQLITE_ENABLE_FTS2
2860   if( !db->mallocFailed && rc==SQLITE_OK ){
2861     extern int sqlite3Fts2Init(sqlite3*);
2862     rc = sqlite3Fts2Init(db);
2863   }
2864 #endif
2865 
2866 #ifdef SQLITE_ENABLE_FTS3
2867   if( !db->mallocFailed && rc==SQLITE_OK ){
2868     rc = sqlite3Fts3Init(db);
2869   }
2870 #endif
2871 
2872 #ifdef SQLITE_ENABLE_ICU
2873   if( !db->mallocFailed && rc==SQLITE_OK ){
2874     rc = sqlite3IcuInit(db);
2875   }
2876 #endif
2877 
2878 #ifdef SQLITE_ENABLE_RTREE
2879   if( !db->mallocFailed && rc==SQLITE_OK){
2880     rc = sqlite3RtreeInit(db);
2881   }
2882 #endif
2883 
2884 #ifdef SQLITE_ENABLE_DBSTAT_VTAB
2885   if( !db->mallocFailed && rc==SQLITE_OK){
2886     rc = sqlite3DbstatRegister(db);
2887   }
2888 #endif
2889 
2890   /* -DSQLITE_DEFAULT_LOCKING_MODE=1 makes EXCLUSIVE the default locking
2891   ** mode.  -DSQLITE_DEFAULT_LOCKING_MODE=0 make NORMAL the default locking
2892   ** mode.  Doing nothing at all also makes NORMAL the default.
2893   */
2894 #ifdef SQLITE_DEFAULT_LOCKING_MODE
2895   db->dfltLockMode = SQLITE_DEFAULT_LOCKING_MODE;
2896   sqlite3PagerLockingMode(sqlite3BtreePager(db->aDb[0].pBt),
2897                           SQLITE_DEFAULT_LOCKING_MODE);
2898 #endif
2899 
2900   if( rc ) sqlite3Error(db, rc);
2901 
2902   /* Enable the lookaside-malloc subsystem */
2903   setupLookaside(db, 0, sqlite3GlobalConfig.szLookaside,
2904                         sqlite3GlobalConfig.nLookaside);
2905 
2906   sqlite3_wal_autocheckpoint(db, SQLITE_DEFAULT_WAL_AUTOCHECKPOINT);
2907 
2908 opendb_out:
2909   sqlite3_free(zOpen);
2910   if( db ){
2911     assert( db->mutex!=0 || isThreadsafe==0
2912            || sqlite3GlobalConfig.bFullMutex==0 );
2913     sqlite3_mutex_leave(db->mutex);
2914   }
2915   rc = sqlite3_errcode(db);
2916   assert( db!=0 || rc==SQLITE_NOMEM );
2917   if( rc==SQLITE_NOMEM ){
2918     sqlite3_close(db);
2919     db = 0;
2920   }else if( rc!=SQLITE_OK ){
2921     db->magic = SQLITE_MAGIC_SICK;
2922   }
2923   *ppDb = db;
2924 #ifdef SQLITE_ENABLE_SQLLOG
2925   if( sqlite3GlobalConfig.xSqllog ){
2926     /* Opening a db handle. Fourth parameter is passed 0. */
2927     void *pArg = sqlite3GlobalConfig.pSqllogArg;
2928     sqlite3GlobalConfig.xSqllog(pArg, db, zFilename, 0);
2929   }
2930 #endif
2931   return rc & 0xff;
2932 }
2933 
2934 /*
2935 ** Open a new database handle.
2936 */
2937 int sqlite3_open(
2938   const char *zFilename,
2939   sqlite3 **ppDb
2940 ){
2941   return openDatabase(zFilename, ppDb,
2942                       SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
2943 }
2944 int sqlite3_open_v2(
2945   const char *filename,   /* Database filename (UTF-8) */
2946   sqlite3 **ppDb,         /* OUT: SQLite db handle */
2947   int flags,              /* Flags */
2948   const char *zVfs        /* Name of VFS module to use */
2949 ){
2950   return openDatabase(filename, ppDb, (unsigned int)flags, zVfs);
2951 }
2952 
2953 #ifndef SQLITE_OMIT_UTF16
2954 /*
2955 ** Open a new database handle.
2956 */
2957 int sqlite3_open16(
2958   const void *zFilename,
2959   sqlite3 **ppDb
2960 ){
2961   char const *zFilename8;   /* zFilename encoded in UTF-8 instead of UTF-16 */
2962   sqlite3_value *pVal;
2963   int rc;
2964 
2965 #ifdef SQLITE_ENABLE_API_ARMOR
2966   if( ppDb==0 ) return SQLITE_MISUSE_BKPT;
2967 #endif
2968   *ppDb = 0;
2969 #ifndef SQLITE_OMIT_AUTOINIT
2970   rc = sqlite3_initialize();
2971   if( rc ) return rc;
2972 #endif
2973   if( zFilename==0 ) zFilename = "\000\000";
2974   pVal = sqlite3ValueNew(0);
2975   sqlite3ValueSetStr(pVal, -1, zFilename, SQLITE_UTF16NATIVE, SQLITE_STATIC);
2976   zFilename8 = sqlite3ValueText(pVal, SQLITE_UTF8);
2977   if( zFilename8 ){
2978     rc = openDatabase(zFilename8, ppDb,
2979                       SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
2980     assert( *ppDb || rc==SQLITE_NOMEM );
2981     if( rc==SQLITE_OK && !DbHasProperty(*ppDb, 0, DB_SchemaLoaded) ){
2982       SCHEMA_ENC(*ppDb) = ENC(*ppDb) = SQLITE_UTF16NATIVE;
2983     }
2984   }else{
2985     rc = SQLITE_NOMEM;
2986   }
2987   sqlite3ValueFree(pVal);
2988 
2989   return rc & 0xff;
2990 }
2991 #endif /* SQLITE_OMIT_UTF16 */
2992 
2993 /*
2994 ** Register a new collation sequence with the database handle db.
2995 */
2996 int sqlite3_create_collation(
2997   sqlite3* db,
2998   const char *zName,
2999   int enc,
3000   void* pCtx,
3001   int(*xCompare)(void*,int,const void*,int,const void*)
3002 ){
3003   return sqlite3_create_collation_v2(db, zName, enc, pCtx, xCompare, 0);
3004 }
3005 
3006 /*
3007 ** Register a new collation sequence with the database handle db.
3008 */
3009 int sqlite3_create_collation_v2(
3010   sqlite3* db,
3011   const char *zName,
3012   int enc,
3013   void* pCtx,
3014   int(*xCompare)(void*,int,const void*,int,const void*),
3015   void(*xDel)(void*)
3016 ){
3017   int rc;
3018 
3019 #ifdef SQLITE_ENABLE_API_ARMOR
3020   if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
3021 #endif
3022   sqlite3_mutex_enter(db->mutex);
3023   assert( !db->mallocFailed );
3024   rc = createCollation(db, zName, (u8)enc, pCtx, xCompare, xDel);
3025   rc = sqlite3ApiExit(db, rc);
3026   sqlite3_mutex_leave(db->mutex);
3027   return rc;
3028 }
3029 
3030 #ifndef SQLITE_OMIT_UTF16
3031 /*
3032 ** Register a new collation sequence with the database handle db.
3033 */
3034 int sqlite3_create_collation16(
3035   sqlite3* db,
3036   const void *zName,
3037   int enc,
3038   void* pCtx,
3039   int(*xCompare)(void*,int,const void*,int,const void*)
3040 ){
3041   int rc = SQLITE_OK;
3042   char *zName8;
3043 
3044 #ifdef SQLITE_ENABLE_API_ARMOR
3045   if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
3046 #endif
3047   sqlite3_mutex_enter(db->mutex);
3048   assert( !db->mallocFailed );
3049   zName8 = sqlite3Utf16to8(db, zName, -1, SQLITE_UTF16NATIVE);
3050   if( zName8 ){
3051     rc = createCollation(db, zName8, (u8)enc, pCtx, xCompare, 0);
3052     sqlite3DbFree(db, zName8);
3053   }
3054   rc = sqlite3ApiExit(db, rc);
3055   sqlite3_mutex_leave(db->mutex);
3056   return rc;
3057 }
3058 #endif /* SQLITE_OMIT_UTF16 */
3059 
3060 /*
3061 ** Register a collation sequence factory callback with the database handle
3062 ** db. Replace any previously installed collation sequence factory.
3063 */
3064 int sqlite3_collation_needed(
3065   sqlite3 *db,
3066   void *pCollNeededArg,
3067   void(*xCollNeeded)(void*,sqlite3*,int eTextRep,const char*)
3068 ){
3069 #ifdef SQLITE_ENABLE_API_ARMOR
3070   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3071 #endif
3072   sqlite3_mutex_enter(db->mutex);
3073   db->xCollNeeded = xCollNeeded;
3074   db->xCollNeeded16 = 0;
3075   db->pCollNeededArg = pCollNeededArg;
3076   sqlite3_mutex_leave(db->mutex);
3077   return SQLITE_OK;
3078 }
3079 
3080 #ifndef SQLITE_OMIT_UTF16
3081 /*
3082 ** Register a collation sequence factory callback with the database handle
3083 ** db. Replace any previously installed collation sequence factory.
3084 */
3085 int sqlite3_collation_needed16(
3086   sqlite3 *db,
3087   void *pCollNeededArg,
3088   void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*)
3089 ){
3090 #ifdef SQLITE_ENABLE_API_ARMOR
3091   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3092 #endif
3093   sqlite3_mutex_enter(db->mutex);
3094   db->xCollNeeded = 0;
3095   db->xCollNeeded16 = xCollNeeded16;
3096   db->pCollNeededArg = pCollNeededArg;
3097   sqlite3_mutex_leave(db->mutex);
3098   return SQLITE_OK;
3099 }
3100 #endif /* SQLITE_OMIT_UTF16 */
3101 
3102 #ifndef SQLITE_OMIT_DEPRECATED
3103 /*
3104 ** This function is now an anachronism. It used to be used to recover from a
3105 ** malloc() failure, but SQLite now does this automatically.
3106 */
3107 int sqlite3_global_recover(void){
3108   return SQLITE_OK;
3109 }
3110 #endif
3111 
3112 /*
3113 ** Test to see whether or not the database connection is in autocommit
3114 ** mode.  Return TRUE if it is and FALSE if not.  Autocommit mode is on
3115 ** by default.  Autocommit is disabled by a BEGIN statement and reenabled
3116 ** by the next COMMIT or ROLLBACK.
3117 */
3118 int sqlite3_get_autocommit(sqlite3 *db){
3119 #ifdef SQLITE_ENABLE_API_ARMOR
3120   if( !sqlite3SafetyCheckOk(db) ){
3121     (void)SQLITE_MISUSE_BKPT;
3122     return 0;
3123   }
3124 #endif
3125   return db->autoCommit;
3126 }
3127 
3128 /*
3129 ** The following routines are substitutes for constants SQLITE_CORRUPT,
3130 ** SQLITE_MISUSE, SQLITE_CANTOPEN, SQLITE_IOERR and possibly other error
3131 ** constants.  They serve two purposes:
3132 **
3133 **   1.  Serve as a convenient place to set a breakpoint in a debugger
3134 **       to detect when version error conditions occurs.
3135 **
3136 **   2.  Invoke sqlite3_log() to provide the source code location where
3137 **       a low-level error is first detected.
3138 */
3139 int sqlite3CorruptError(int lineno){
3140   testcase( sqlite3GlobalConfig.xLog!=0 );
3141   sqlite3_log(SQLITE_CORRUPT,
3142               "database corruption at line %d of [%.10s]",
3143               lineno, 20+sqlite3_sourceid());
3144   return SQLITE_CORRUPT;
3145 }
3146 int sqlite3MisuseError(int lineno){
3147   testcase( sqlite3GlobalConfig.xLog!=0 );
3148   sqlite3_log(SQLITE_MISUSE,
3149               "misuse at line %d of [%.10s]",
3150               lineno, 20+sqlite3_sourceid());
3151   return SQLITE_MISUSE;
3152 }
3153 int sqlite3CantopenError(int lineno){
3154   testcase( sqlite3GlobalConfig.xLog!=0 );
3155   sqlite3_log(SQLITE_CANTOPEN,
3156               "cannot open file at line %d of [%.10s]",
3157               lineno, 20+sqlite3_sourceid());
3158   return SQLITE_CANTOPEN;
3159 }
3160 
3161 
3162 #ifndef SQLITE_OMIT_DEPRECATED
3163 /*
3164 ** This is a convenience routine that makes sure that all thread-specific
3165 ** data for this thread has been deallocated.
3166 **
3167 ** SQLite no longer uses thread-specific data so this routine is now a
3168 ** no-op.  It is retained for historical compatibility.
3169 */
3170 void sqlite3_thread_cleanup(void){
3171 }
3172 #endif
3173 
3174 /*
3175 ** Return meta information about a specific column of a database table.
3176 ** See comment in sqlite3.h (sqlite.h.in) for details.
3177 */
3178 int sqlite3_table_column_metadata(
3179   sqlite3 *db,                /* Connection handle */
3180   const char *zDbName,        /* Database name or NULL */
3181   const char *zTableName,     /* Table name */
3182   const char *zColumnName,    /* Column name */
3183   char const **pzDataType,    /* OUTPUT: Declared data type */
3184   char const **pzCollSeq,     /* OUTPUT: Collation sequence name */
3185   int *pNotNull,              /* OUTPUT: True if NOT NULL constraint exists */
3186   int *pPrimaryKey,           /* OUTPUT: True if column part of PK */
3187   int *pAutoinc               /* OUTPUT: True if column is auto-increment */
3188 ){
3189   int rc;
3190   char *zErrMsg = 0;
3191   Table *pTab = 0;
3192   Column *pCol = 0;
3193   int iCol = 0;
3194   char const *zDataType = 0;
3195   char const *zCollSeq = 0;
3196   int notnull = 0;
3197   int primarykey = 0;
3198   int autoinc = 0;
3199 
3200 
3201 #ifdef SQLITE_ENABLE_API_ARMOR
3202   if( !sqlite3SafetyCheckOk(db) || zTableName==0 ){
3203     return SQLITE_MISUSE_BKPT;
3204   }
3205 #endif
3206 
3207   /* Ensure the database schema has been loaded */
3208   sqlite3_mutex_enter(db->mutex);
3209   sqlite3BtreeEnterAll(db);
3210   rc = sqlite3Init(db, &zErrMsg);
3211   if( SQLITE_OK!=rc ){
3212     goto error_out;
3213   }
3214 
3215   /* Locate the table in question */
3216   pTab = sqlite3FindTable(db, zTableName, zDbName);
3217   if( !pTab || pTab->pSelect ){
3218     pTab = 0;
3219     goto error_out;
3220   }
3221 
3222   /* Find the column for which info is requested */
3223   if( zColumnName==0 ){
3224     /* Query for existance of table only */
3225   }else{
3226     for(iCol=0; iCol<pTab->nCol; iCol++){
3227       pCol = &pTab->aCol[iCol];
3228       if( 0==sqlite3StrICmp(pCol->zName, zColumnName) ){
3229         break;
3230       }
3231     }
3232     if( iCol==pTab->nCol ){
3233       if( HasRowid(pTab) && sqlite3IsRowid(zColumnName) ){
3234         iCol = pTab->iPKey;
3235         pCol = iCol>=0 ? &pTab->aCol[iCol] : 0;
3236       }else{
3237         pTab = 0;
3238         goto error_out;
3239       }
3240     }
3241   }
3242 
3243   /* The following block stores the meta information that will be returned
3244   ** to the caller in local variables zDataType, zCollSeq, notnull, primarykey
3245   ** and autoinc. At this point there are two possibilities:
3246   **
3247   **     1. The specified column name was rowid", "oid" or "_rowid_"
3248   **        and there is no explicitly declared IPK column.
3249   **
3250   **     2. The table is not a view and the column name identified an
3251   **        explicitly declared column. Copy meta information from *pCol.
3252   */
3253   if( pCol ){
3254     zDataType = pCol->zType;
3255     zCollSeq = pCol->zColl;
3256     notnull = pCol->notNull!=0;
3257     primarykey  = (pCol->colFlags & COLFLAG_PRIMKEY)!=0;
3258     autoinc = pTab->iPKey==iCol && (pTab->tabFlags & TF_Autoincrement)!=0;
3259   }else{
3260     zDataType = "INTEGER";
3261     primarykey = 1;
3262   }
3263   if( !zCollSeq ){
3264     zCollSeq = "BINARY";
3265   }
3266 
3267 error_out:
3268   sqlite3BtreeLeaveAll(db);
3269 
3270   /* Whether the function call succeeded or failed, set the output parameters
3271   ** to whatever their local counterparts contain. If an error did occur,
3272   ** this has the effect of zeroing all output parameters.
3273   */
3274   if( pzDataType ) *pzDataType = zDataType;
3275   if( pzCollSeq ) *pzCollSeq = zCollSeq;
3276   if( pNotNull ) *pNotNull = notnull;
3277   if( pPrimaryKey ) *pPrimaryKey = primarykey;
3278   if( pAutoinc ) *pAutoinc = autoinc;
3279 
3280   if( SQLITE_OK==rc && !pTab ){
3281     sqlite3DbFree(db, zErrMsg);
3282     zErrMsg = sqlite3MPrintf(db, "no such table column: %s.%s", zTableName,
3283         zColumnName);
3284     rc = SQLITE_ERROR;
3285   }
3286   sqlite3ErrorWithMsg(db, rc, (zErrMsg?"%s":0), zErrMsg);
3287   sqlite3DbFree(db, zErrMsg);
3288   rc = sqlite3ApiExit(db, rc);
3289   sqlite3_mutex_leave(db->mutex);
3290   return rc;
3291 }
3292 
3293 /*
3294 ** Sleep for a little while.  Return the amount of time slept.
3295 */
3296 int sqlite3_sleep(int ms){
3297   sqlite3_vfs *pVfs;
3298   int rc;
3299   pVfs = sqlite3_vfs_find(0);
3300   if( pVfs==0 ) return 0;
3301 
3302   /* This function works in milliseconds, but the underlying OsSleep()
3303   ** API uses microseconds. Hence the 1000's.
3304   */
3305   rc = (sqlite3OsSleep(pVfs, 1000*ms)/1000);
3306   return rc;
3307 }
3308 
3309 /*
3310 ** Enable or disable the extended result codes.
3311 */
3312 int sqlite3_extended_result_codes(sqlite3 *db, int onoff){
3313 #ifdef SQLITE_ENABLE_API_ARMOR
3314   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3315 #endif
3316   sqlite3_mutex_enter(db->mutex);
3317   db->errMask = onoff ? 0xffffffff : 0xff;
3318   sqlite3_mutex_leave(db->mutex);
3319   return SQLITE_OK;
3320 }
3321 
3322 /*
3323 ** Invoke the xFileControl method on a particular database.
3324 */
3325 int sqlite3_file_control(sqlite3 *db, const char *zDbName, int op, void *pArg){
3326   int rc = SQLITE_ERROR;
3327   Btree *pBtree;
3328 
3329 #ifdef SQLITE_ENABLE_API_ARMOR
3330   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3331 #endif
3332   sqlite3_mutex_enter(db->mutex);
3333   pBtree = sqlite3DbNameToBtree(db, zDbName);
3334   if( pBtree ){
3335     Pager *pPager;
3336     sqlite3_file *fd;
3337     sqlite3BtreeEnter(pBtree);
3338     pPager = sqlite3BtreePager(pBtree);
3339     assert( pPager!=0 );
3340     fd = sqlite3PagerFile(pPager);
3341     assert( fd!=0 );
3342     if( op==SQLITE_FCNTL_FILE_POINTER ){
3343       *(sqlite3_file**)pArg = fd;
3344       rc = SQLITE_OK;
3345     }else if( fd->pMethods ){
3346       rc = sqlite3OsFileControl(fd, op, pArg);
3347     }else{
3348       rc = SQLITE_NOTFOUND;
3349     }
3350     sqlite3BtreeLeave(pBtree);
3351   }
3352   sqlite3_mutex_leave(db->mutex);
3353   return rc;
3354 }
3355 
3356 /*
3357 ** Interface to the testing logic.
3358 */
3359 int sqlite3_test_control(int op, ...){
3360   int rc = 0;
3361 #ifdef SQLITE_OMIT_BUILTIN_TEST
3362   UNUSED_PARAMETER(op);
3363 #else
3364   va_list ap;
3365   va_start(ap, op);
3366   switch( op ){
3367 
3368     /*
3369     ** Save the current state of the PRNG.
3370     */
3371     case SQLITE_TESTCTRL_PRNG_SAVE: {
3372       sqlite3PrngSaveState();
3373       break;
3374     }
3375 
3376     /*
3377     ** Restore the state of the PRNG to the last state saved using
3378     ** PRNG_SAVE.  If PRNG_SAVE has never before been called, then
3379     ** this verb acts like PRNG_RESET.
3380     */
3381     case SQLITE_TESTCTRL_PRNG_RESTORE: {
3382       sqlite3PrngRestoreState();
3383       break;
3384     }
3385 
3386     /*
3387     ** Reset the PRNG back to its uninitialized state.  The next call
3388     ** to sqlite3_randomness() will reseed the PRNG using a single call
3389     ** to the xRandomness method of the default VFS.
3390     */
3391     case SQLITE_TESTCTRL_PRNG_RESET: {
3392       sqlite3_randomness(0,0);
3393       break;
3394     }
3395 
3396     /*
3397     **  sqlite3_test_control(BITVEC_TEST, size, program)
3398     **
3399     ** Run a test against a Bitvec object of size.  The program argument
3400     ** is an array of integers that defines the test.  Return -1 on a
3401     ** memory allocation error, 0 on success, or non-zero for an error.
3402     ** See the sqlite3BitvecBuiltinTest() for additional information.
3403     */
3404     case SQLITE_TESTCTRL_BITVEC_TEST: {
3405       int sz = va_arg(ap, int);
3406       int *aProg = va_arg(ap, int*);
3407       rc = sqlite3BitvecBuiltinTest(sz, aProg);
3408       break;
3409     }
3410 
3411     /*
3412     **  sqlite3_test_control(FAULT_INSTALL, xCallback)
3413     **
3414     ** Arrange to invoke xCallback() whenever sqlite3FaultSim() is called,
3415     ** if xCallback is not NULL.
3416     **
3417     ** As a test of the fault simulator mechanism itself, sqlite3FaultSim(0)
3418     ** is called immediately after installing the new callback and the return
3419     ** value from sqlite3FaultSim(0) becomes the return from
3420     ** sqlite3_test_control().
3421     */
3422     case SQLITE_TESTCTRL_FAULT_INSTALL: {
3423       /* MSVC is picky about pulling func ptrs from va lists.
3424       ** http://support.microsoft.com/kb/47961
3425       ** sqlite3GlobalConfig.xTestCallback = va_arg(ap, int(*)(int));
3426       */
3427       typedef int(*TESTCALLBACKFUNC_t)(int);
3428       sqlite3GlobalConfig.xTestCallback = va_arg(ap, TESTCALLBACKFUNC_t);
3429       rc = sqlite3FaultSim(0);
3430       break;
3431     }
3432 
3433     /*
3434     **  sqlite3_test_control(BENIGN_MALLOC_HOOKS, xBegin, xEnd)
3435     **
3436     ** Register hooks to call to indicate which malloc() failures
3437     ** are benign.
3438     */
3439     case SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS: {
3440       typedef void (*void_function)(void);
3441       void_function xBenignBegin;
3442       void_function xBenignEnd;
3443       xBenignBegin = va_arg(ap, void_function);
3444       xBenignEnd = va_arg(ap, void_function);
3445       sqlite3BenignMallocHooks(xBenignBegin, xBenignEnd);
3446       break;
3447     }
3448 
3449     /*
3450     **  sqlite3_test_control(SQLITE_TESTCTRL_PENDING_BYTE, unsigned int X)
3451     **
3452     ** Set the PENDING byte to the value in the argument, if X>0.
3453     ** Make no changes if X==0.  Return the value of the pending byte
3454     ** as it existing before this routine was called.
3455     **
3456     ** IMPORTANT:  Changing the PENDING byte from 0x40000000 results in
3457     ** an incompatible database file format.  Changing the PENDING byte
3458     ** while any database connection is open results in undefined and
3459     ** deleterious behavior.
3460     */
3461     case SQLITE_TESTCTRL_PENDING_BYTE: {
3462       rc = PENDING_BYTE;
3463 #ifndef SQLITE_OMIT_WSD
3464       {
3465         unsigned int newVal = va_arg(ap, unsigned int);
3466         if( newVal ) sqlite3PendingByte = newVal;
3467       }
3468 #endif
3469       break;
3470     }
3471 
3472     /*
3473     **  sqlite3_test_control(SQLITE_TESTCTRL_ASSERT, int X)
3474     **
3475     ** This action provides a run-time test to see whether or not
3476     ** assert() was enabled at compile-time.  If X is true and assert()
3477     ** is enabled, then the return value is true.  If X is true and
3478     ** assert() is disabled, then the return value is zero.  If X is
3479     ** false and assert() is enabled, then the assertion fires and the
3480     ** process aborts.  If X is false and assert() is disabled, then the
3481     ** return value is zero.
3482     */
3483     case SQLITE_TESTCTRL_ASSERT: {
3484       volatile int x = 0;
3485       assert( (x = va_arg(ap,int))!=0 );
3486       rc = x;
3487       break;
3488     }
3489 
3490 
3491     /*
3492     **  sqlite3_test_control(SQLITE_TESTCTRL_ALWAYS, int X)
3493     **
3494     ** This action provides a run-time test to see how the ALWAYS and
3495     ** NEVER macros were defined at compile-time.
3496     **
3497     ** The return value is ALWAYS(X).
3498     **
3499     ** The recommended test is X==2.  If the return value is 2, that means
3500     ** ALWAYS() and NEVER() are both no-op pass-through macros, which is the
3501     ** default setting.  If the return value is 1, then ALWAYS() is either
3502     ** hard-coded to true or else it asserts if its argument is false.
3503     ** The first behavior (hard-coded to true) is the case if
3504     ** SQLITE_TESTCTRL_ASSERT shows that assert() is disabled and the second
3505     ** behavior (assert if the argument to ALWAYS() is false) is the case if
3506     ** SQLITE_TESTCTRL_ASSERT shows that assert() is enabled.
3507     **
3508     ** The run-time test procedure might look something like this:
3509     **
3510     **    if( sqlite3_test_control(SQLITE_TESTCTRL_ALWAYS, 2)==2 ){
3511     **      // ALWAYS() and NEVER() are no-op pass-through macros
3512     **    }else if( sqlite3_test_control(SQLITE_TESTCTRL_ASSERT, 1) ){
3513     **      // ALWAYS(x) asserts that x is true. NEVER(x) asserts x is false.
3514     **    }else{
3515     **      // ALWAYS(x) is a constant 1.  NEVER(x) is a constant 0.
3516     **    }
3517     */
3518     case SQLITE_TESTCTRL_ALWAYS: {
3519       int x = va_arg(ap,int);
3520       rc = ALWAYS(x);
3521       break;
3522     }
3523 
3524     /*
3525     **   sqlite3_test_control(SQLITE_TESTCTRL_BYTEORDER);
3526     **
3527     ** The integer returned reveals the byte-order of the computer on which
3528     ** SQLite is running:
3529     **
3530     **       1     big-endian,    determined at run-time
3531     **      10     little-endian, determined at run-time
3532     **  432101     big-endian,    determined at compile-time
3533     **  123410     little-endian, determined at compile-time
3534     */
3535     case SQLITE_TESTCTRL_BYTEORDER: {
3536       rc = SQLITE_BYTEORDER*100 + SQLITE_LITTLEENDIAN*10 + SQLITE_BIGENDIAN;
3537       break;
3538     }
3539 
3540     /*   sqlite3_test_control(SQLITE_TESTCTRL_RESERVE, sqlite3 *db, int N)
3541     **
3542     ** Set the nReserve size to N for the main database on the database
3543     ** connection db.
3544     */
3545     case SQLITE_TESTCTRL_RESERVE: {
3546       sqlite3 *db = va_arg(ap, sqlite3*);
3547       int x = va_arg(ap,int);
3548       sqlite3_mutex_enter(db->mutex);
3549       sqlite3BtreeSetPageSize(db->aDb[0].pBt, 0, x, 0);
3550       sqlite3_mutex_leave(db->mutex);
3551       break;
3552     }
3553 
3554     /*  sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS, sqlite3 *db, int N)
3555     **
3556     ** Enable or disable various optimizations for testing purposes.  The
3557     ** argument N is a bitmask of optimizations to be disabled.  For normal
3558     ** operation N should be 0.  The idea is that a test program (like the
3559     ** SQL Logic Test or SLT test module) can run the same SQL multiple times
3560     ** with various optimizations disabled to verify that the same answer
3561     ** is obtained in every case.
3562     */
3563     case SQLITE_TESTCTRL_OPTIMIZATIONS: {
3564       sqlite3 *db = va_arg(ap, sqlite3*);
3565       db->dbOptFlags = (u16)(va_arg(ap, int) & 0xffff);
3566       break;
3567     }
3568 
3569 #ifdef SQLITE_N_KEYWORD
3570     /* sqlite3_test_control(SQLITE_TESTCTRL_ISKEYWORD, const char *zWord)
3571     **
3572     ** If zWord is a keyword recognized by the parser, then return the
3573     ** number of keywords.  Or if zWord is not a keyword, return 0.
3574     **
3575     ** This test feature is only available in the amalgamation since
3576     ** the SQLITE_N_KEYWORD macro is not defined in this file if SQLite
3577     ** is built using separate source files.
3578     */
3579     case SQLITE_TESTCTRL_ISKEYWORD: {
3580       const char *zWord = va_arg(ap, const char*);
3581       int n = sqlite3Strlen30(zWord);
3582       rc = (sqlite3KeywordCode((u8*)zWord, n)!=TK_ID) ? SQLITE_N_KEYWORD : 0;
3583       break;
3584     }
3585 #endif
3586 
3587     /* sqlite3_test_control(SQLITE_TESTCTRL_SCRATCHMALLOC, sz, &pNew, pFree);
3588     **
3589     ** Pass pFree into sqlite3ScratchFree().
3590     ** If sz>0 then allocate a scratch buffer into pNew.
3591     */
3592     case SQLITE_TESTCTRL_SCRATCHMALLOC: {
3593       void *pFree, **ppNew;
3594       int sz;
3595       sz = va_arg(ap, int);
3596       ppNew = va_arg(ap, void**);
3597       pFree = va_arg(ap, void*);
3598       if( sz ) *ppNew = sqlite3ScratchMalloc(sz);
3599       sqlite3ScratchFree(pFree);
3600       break;
3601     }
3602 
3603     /*   sqlite3_test_control(SQLITE_TESTCTRL_LOCALTIME_FAULT, int onoff);
3604     **
3605     ** If parameter onoff is non-zero, configure the wrappers so that all
3606     ** subsequent calls to localtime() and variants fail. If onoff is zero,
3607     ** undo this setting.
3608     */
3609     case SQLITE_TESTCTRL_LOCALTIME_FAULT: {
3610       sqlite3GlobalConfig.bLocaltimeFault = va_arg(ap, int);
3611       break;
3612     }
3613 
3614     /*   sqlite3_test_control(SQLITE_TESTCTRL_NEVER_CORRUPT, int);
3615     **
3616     ** Set or clear a flag that indicates that the database file is always well-
3617     ** formed and never corrupt.  This flag is clear by default, indicating that
3618     ** database files might have arbitrary corruption.  Setting the flag during
3619     ** testing causes certain assert() statements in the code to be activated
3620     ** that demonstrat invariants on well-formed database files.
3621     */
3622     case SQLITE_TESTCTRL_NEVER_CORRUPT: {
3623       sqlite3GlobalConfig.neverCorrupt = va_arg(ap, int);
3624       break;
3625     }
3626 
3627 
3628     /*   sqlite3_test_control(SQLITE_TESTCTRL_VDBE_COVERAGE, xCallback, ptr);
3629     **
3630     ** Set the VDBE coverage callback function to xCallback with context
3631     ** pointer ptr.
3632     */
3633     case SQLITE_TESTCTRL_VDBE_COVERAGE: {
3634 #ifdef SQLITE_VDBE_COVERAGE
3635       typedef void (*branch_callback)(void*,int,u8,u8);
3636       sqlite3GlobalConfig.xVdbeBranch = va_arg(ap,branch_callback);
3637       sqlite3GlobalConfig.pVdbeBranchArg = va_arg(ap,void*);
3638 #endif
3639       break;
3640     }
3641 
3642     /*   sqlite3_test_control(SQLITE_TESTCTRL_SORTER_MMAP, db, nMax); */
3643     case SQLITE_TESTCTRL_SORTER_MMAP: {
3644       sqlite3 *db = va_arg(ap, sqlite3*);
3645       db->nMaxSorterMmap = va_arg(ap, int);
3646       break;
3647     }
3648 
3649     /*   sqlite3_test_control(SQLITE_TESTCTRL_ISINIT);
3650     **
3651     ** Return SQLITE_OK if SQLite has been initialized and SQLITE_ERROR if
3652     ** not.
3653     */
3654     case SQLITE_TESTCTRL_ISINIT: {
3655       if( sqlite3GlobalConfig.isInit==0 ) rc = SQLITE_ERROR;
3656       break;
3657     }
3658 
3659     /*  sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, db, dbName, onOff, tnum);
3660     **
3661     ** This test control is used to create imposter tables.  "db" is a pointer
3662     ** to the database connection.  dbName is the database name (ex: "main" or
3663     ** "temp") which will receive the imposter.  "onOff" turns imposter mode on
3664     ** or off.  "tnum" is the root page of the b-tree to which the imposter
3665     ** table should connect.
3666     **
3667     ** Enable imposter mode only when the schema has already been parsed.  Then
3668     ** run a single CREATE TABLE statement to construct the imposter table in
3669     ** the parsed schema.  Then turn imposter mode back off again.
3670     **
3671     ** If onOff==0 and tnum>0 then reset the schema for all databases, causing
3672     ** the schema to be reparsed the next time it is needed.  This has the
3673     ** effect of erasing all imposter tables.
3674     */
3675     case SQLITE_TESTCTRL_IMPOSTER: {
3676       sqlite3 *db = va_arg(ap, sqlite3*);
3677       sqlite3_mutex_enter(db->mutex);
3678       db->init.iDb = sqlite3FindDbName(db, va_arg(ap,const char*));
3679       db->init.busy = db->init.imposterTable = va_arg(ap,int);
3680       db->init.newTnum = va_arg(ap,int);
3681       if( db->init.busy==0 && db->init.newTnum>0 ){
3682         sqlite3ResetAllSchemasOfConnection(db);
3683       }
3684       sqlite3_mutex_leave(db->mutex);
3685       break;
3686     }
3687   }
3688   va_end(ap);
3689 #endif /* SQLITE_OMIT_BUILTIN_TEST */
3690   return rc;
3691 }
3692 
3693 /*
3694 ** This is a utility routine, useful to VFS implementations, that checks
3695 ** to see if a database file was a URI that contained a specific query
3696 ** parameter, and if so obtains the value of the query parameter.
3697 **
3698 ** The zFilename argument is the filename pointer passed into the xOpen()
3699 ** method of a VFS implementation.  The zParam argument is the name of the
3700 ** query parameter we seek.  This routine returns the value of the zParam
3701 ** parameter if it exists.  If the parameter does not exist, this routine
3702 ** returns a NULL pointer.
3703 */
3704 const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam){
3705   if( zFilename==0 || zParam==0 ) return 0;
3706   zFilename += sqlite3Strlen30(zFilename) + 1;
3707   while( zFilename[0] ){
3708     int x = strcmp(zFilename, zParam);
3709     zFilename += sqlite3Strlen30(zFilename) + 1;
3710     if( x==0 ) return zFilename;
3711     zFilename += sqlite3Strlen30(zFilename) + 1;
3712   }
3713   return 0;
3714 }
3715 
3716 /*
3717 ** Return a boolean value for a query parameter.
3718 */
3719 int sqlite3_uri_boolean(const char *zFilename, const char *zParam, int bDflt){
3720   const char *z = sqlite3_uri_parameter(zFilename, zParam);
3721   bDflt = bDflt!=0;
3722   return z ? sqlite3GetBoolean(z, bDflt) : bDflt;
3723 }
3724 
3725 /*
3726 ** Return a 64-bit integer value for a query parameter.
3727 */
3728 sqlite3_int64 sqlite3_uri_int64(
3729   const char *zFilename,    /* Filename as passed to xOpen */
3730   const char *zParam,       /* URI parameter sought */
3731   sqlite3_int64 bDflt       /* return if parameter is missing */
3732 ){
3733   const char *z = sqlite3_uri_parameter(zFilename, zParam);
3734   sqlite3_int64 v;
3735   if( z && sqlite3DecOrHexToI64(z, &v)==SQLITE_OK ){
3736     bDflt = v;
3737   }
3738   return bDflt;
3739 }
3740 
3741 /*
3742 ** Return the Btree pointer identified by zDbName.  Return NULL if not found.
3743 */
3744 Btree *sqlite3DbNameToBtree(sqlite3 *db, const char *zDbName){
3745   int i;
3746   for(i=0; i<db->nDb; i++){
3747     if( db->aDb[i].pBt
3748      && (zDbName==0 || sqlite3StrICmp(zDbName, db->aDb[i].zName)==0)
3749     ){
3750       return db->aDb[i].pBt;
3751     }
3752   }
3753   return 0;
3754 }
3755 
3756 /*
3757 ** Return the filename of the database associated with a database
3758 ** connection.
3759 */
3760 const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName){
3761   Btree *pBt;
3762 #ifdef SQLITE_ENABLE_API_ARMOR
3763   if( !sqlite3SafetyCheckOk(db) ){
3764     (void)SQLITE_MISUSE_BKPT;
3765     return 0;
3766   }
3767 #endif
3768   pBt = sqlite3DbNameToBtree(db, zDbName);
3769   return pBt ? sqlite3BtreeGetFilename(pBt) : 0;
3770 }
3771 
3772 /*
3773 ** Return 1 if database is read-only or 0 if read/write.  Return -1 if
3774 ** no such database exists.
3775 */
3776 int sqlite3_db_readonly(sqlite3 *db, const char *zDbName){
3777   Btree *pBt;
3778 #ifdef SQLITE_ENABLE_API_ARMOR
3779   if( !sqlite3SafetyCheckOk(db) ){
3780     (void)SQLITE_MISUSE_BKPT;
3781     return -1;
3782   }
3783 #endif
3784   pBt = sqlite3DbNameToBtree(db, zDbName);
3785   return pBt ? sqlite3BtreeIsReadonly(pBt) : -1;
3786 }
3787