xref: /sqlite-3.40.0/src/main.c (revision dca92904)
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 #ifndef SQLITE_OMIT_LOOKASIDE
646   void *pStart;
647   if( db->lookaside.nOut ){
648     return SQLITE_BUSY;
649   }
650   /* Free any existing lookaside buffer for this handle before
651   ** allocating a new one so we don't have to have space for
652   ** both at the same time.
653   */
654   if( db->lookaside.bMalloced ){
655     sqlite3_free(db->lookaside.pStart);
656   }
657   /* The size of a lookaside slot after ROUNDDOWN8 needs to be larger
658   ** than a pointer to be useful.
659   */
660   sz = ROUNDDOWN8(sz);  /* IMP: R-33038-09382 */
661   if( sz<=(int)sizeof(LookasideSlot*) ) sz = 0;
662   if( cnt<0 ) cnt = 0;
663   if( sz==0 || cnt==0 ){
664     sz = 0;
665     pStart = 0;
666   }else if( pBuf==0 ){
667     sqlite3BeginBenignMalloc();
668     pStart = sqlite3Malloc( sz*cnt );  /* IMP: R-61949-35727 */
669     sqlite3EndBenignMalloc();
670     if( pStart ) cnt = sqlite3MallocSize(pStart)/sz;
671   }else{
672     pStart = pBuf;
673   }
674   db->lookaside.pStart = pStart;
675   db->lookaside.pFree = 0;
676   db->lookaside.sz = (u16)sz;
677   if( pStart ){
678     int i;
679     LookasideSlot *p;
680     assert( sz > (int)sizeof(LookasideSlot*) );
681     p = (LookasideSlot*)pStart;
682     for(i=cnt-1; i>=0; i--){
683       p->pNext = db->lookaside.pFree;
684       db->lookaside.pFree = p;
685       p = (LookasideSlot*)&((u8*)p)[sz];
686     }
687     db->lookaside.pEnd = p;
688     db->lookaside.bEnabled = 1;
689     db->lookaside.bMalloced = pBuf==0 ?1:0;
690   }else{
691     db->lookaside.pStart = db;
692     db->lookaside.pEnd = db;
693     db->lookaside.bEnabled = 0;
694     db->lookaside.bMalloced = 0;
695   }
696 #endif /* SQLITE_OMIT_LOOKASIDE */
697   return SQLITE_OK;
698 }
699 
700 /*
701 ** Return the mutex associated with a database connection.
702 */
703 sqlite3_mutex *sqlite3_db_mutex(sqlite3 *db){
704 #ifdef SQLITE_ENABLE_API_ARMOR
705   if( !sqlite3SafetyCheckOk(db) ){
706     (void)SQLITE_MISUSE_BKPT;
707     return 0;
708   }
709 #endif
710   return db->mutex;
711 }
712 
713 /*
714 ** Free up as much memory as we can from the given database
715 ** connection.
716 */
717 int sqlite3_db_release_memory(sqlite3 *db){
718   int i;
719 
720 #ifdef SQLITE_ENABLE_API_ARMOR
721   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
722 #endif
723   sqlite3_mutex_enter(db->mutex);
724   sqlite3BtreeEnterAll(db);
725   for(i=0; i<db->nDb; i++){
726     Btree *pBt = db->aDb[i].pBt;
727     if( pBt ){
728       Pager *pPager = sqlite3BtreePager(pBt);
729       sqlite3PagerShrink(pPager);
730     }
731   }
732   sqlite3BtreeLeaveAll(db);
733   sqlite3_mutex_leave(db->mutex);
734   return SQLITE_OK;
735 }
736 
737 /*
738 ** Configuration settings for an individual database connection
739 */
740 int sqlite3_db_config(sqlite3 *db, int op, ...){
741   va_list ap;
742   int rc;
743   va_start(ap, op);
744   switch( op ){
745     case SQLITE_DBCONFIG_LOOKASIDE: {
746       void *pBuf = va_arg(ap, void*); /* IMP: R-26835-10964 */
747       int sz = va_arg(ap, int);       /* IMP: R-47871-25994 */
748       int cnt = va_arg(ap, int);      /* IMP: R-04460-53386 */
749       rc = setupLookaside(db, pBuf, sz, cnt);
750       break;
751     }
752     default: {
753       static const struct {
754         int op;      /* The opcode */
755         u32 mask;    /* Mask of the bit in sqlite3.flags to set/clear */
756       } aFlagOp[] = {
757         { SQLITE_DBCONFIG_ENABLE_FKEY,    SQLITE_ForeignKeys    },
758         { SQLITE_DBCONFIG_ENABLE_TRIGGER, SQLITE_EnableTrigger  },
759       };
760       unsigned int i;
761       rc = SQLITE_ERROR; /* IMP: R-42790-23372 */
762       for(i=0; i<ArraySize(aFlagOp); i++){
763         if( aFlagOp[i].op==op ){
764           int onoff = va_arg(ap, int);
765           int *pRes = va_arg(ap, int*);
766           int oldFlags = db->flags;
767           if( onoff>0 ){
768             db->flags |= aFlagOp[i].mask;
769           }else if( onoff==0 ){
770             db->flags &= ~aFlagOp[i].mask;
771           }
772           if( oldFlags!=db->flags ){
773             sqlite3ExpirePreparedStatements(db);
774           }
775           if( pRes ){
776             *pRes = (db->flags & aFlagOp[i].mask)!=0;
777           }
778           rc = SQLITE_OK;
779           break;
780         }
781       }
782       break;
783     }
784   }
785   va_end(ap);
786   return rc;
787 }
788 
789 
790 /*
791 ** Return true if the buffer z[0..n-1] contains all spaces.
792 */
793 static int allSpaces(const char *z, int n){
794   while( n>0 && z[n-1]==' ' ){ n--; }
795   return n==0;
796 }
797 
798 /*
799 ** This is the default collating function named "BINARY" which is always
800 ** available.
801 **
802 ** If the padFlag argument is not NULL then space padding at the end
803 ** of strings is ignored.  This implements the RTRIM collation.
804 */
805 static int binCollFunc(
806   void *padFlag,
807   int nKey1, const void *pKey1,
808   int nKey2, const void *pKey2
809 ){
810   int rc, n;
811   n = nKey1<nKey2 ? nKey1 : nKey2;
812   /* EVIDENCE-OF: R-65033-28449 The built-in BINARY collation compares
813   ** strings byte by byte using the memcmp() function from the standard C
814   ** library. */
815   rc = memcmp(pKey1, pKey2, n);
816   if( rc==0 ){
817     if( padFlag
818      && allSpaces(((char*)pKey1)+n, nKey1-n)
819      && allSpaces(((char*)pKey2)+n, nKey2-n)
820     ){
821       /* EVIDENCE-OF: R-31624-24737 RTRIM is like BINARY except that extra
822       ** spaces at the end of either string do not change the result. In other
823       ** words, strings will compare equal to one another as long as they
824       ** differ only in the number of spaces at the end.
825       */
826     }else{
827       rc = nKey1 - nKey2;
828     }
829   }
830   return rc;
831 }
832 
833 /*
834 ** Another built-in collating sequence: NOCASE.
835 **
836 ** This collating sequence is intended to be used for "case independent
837 ** comparison". SQLite's knowledge of upper and lower case equivalents
838 ** extends only to the 26 characters used in the English language.
839 **
840 ** At the moment there is only a UTF-8 implementation.
841 */
842 static int nocaseCollatingFunc(
843   void *NotUsed,
844   int nKey1, const void *pKey1,
845   int nKey2, const void *pKey2
846 ){
847   int r = sqlite3StrNICmp(
848       (const char *)pKey1, (const char *)pKey2, (nKey1<nKey2)?nKey1:nKey2);
849   UNUSED_PARAMETER(NotUsed);
850   if( 0==r ){
851     r = nKey1-nKey2;
852   }
853   return r;
854 }
855 
856 /*
857 ** Return the ROWID of the most recent insert
858 */
859 sqlite_int64 sqlite3_last_insert_rowid(sqlite3 *db){
860 #ifdef SQLITE_ENABLE_API_ARMOR
861   if( !sqlite3SafetyCheckOk(db) ){
862     (void)SQLITE_MISUSE_BKPT;
863     return 0;
864   }
865 #endif
866   return db->lastRowid;
867 }
868 
869 /*
870 ** Return the number of changes in the most recent call to sqlite3_exec().
871 */
872 int sqlite3_changes(sqlite3 *db){
873 #ifdef SQLITE_ENABLE_API_ARMOR
874   if( !sqlite3SafetyCheckOk(db) ){
875     (void)SQLITE_MISUSE_BKPT;
876     return 0;
877   }
878 #endif
879   return db->nChange;
880 }
881 
882 /*
883 ** Return the number of changes since the database handle was opened.
884 */
885 int sqlite3_total_changes(sqlite3 *db){
886 #ifdef SQLITE_ENABLE_API_ARMOR
887   if( !sqlite3SafetyCheckOk(db) ){
888     (void)SQLITE_MISUSE_BKPT;
889     return 0;
890   }
891 #endif
892   return db->nTotalChange;
893 }
894 
895 /*
896 ** Close all open savepoints. This function only manipulates fields of the
897 ** database handle object, it does not close any savepoints that may be open
898 ** at the b-tree/pager level.
899 */
900 void sqlite3CloseSavepoints(sqlite3 *db){
901   while( db->pSavepoint ){
902     Savepoint *pTmp = db->pSavepoint;
903     db->pSavepoint = pTmp->pNext;
904     sqlite3DbFree(db, pTmp);
905   }
906   db->nSavepoint = 0;
907   db->nStatement = 0;
908   db->isTransactionSavepoint = 0;
909 }
910 
911 /*
912 ** Invoke the destructor function associated with FuncDef p, if any. Except,
913 ** if this is not the last copy of the function, do not invoke it. Multiple
914 ** copies of a single function are created when create_function() is called
915 ** with SQLITE_ANY as the encoding.
916 */
917 static void functionDestroy(sqlite3 *db, FuncDef *p){
918   FuncDestructor *pDestructor = p->pDestructor;
919   if( pDestructor ){
920     pDestructor->nRef--;
921     if( pDestructor->nRef==0 ){
922       pDestructor->xDestroy(pDestructor->pUserData);
923       sqlite3DbFree(db, pDestructor);
924     }
925   }
926 }
927 
928 /*
929 ** Disconnect all sqlite3_vtab objects that belong to database connection
930 ** db. This is called when db is being closed.
931 */
932 static void disconnectAllVtab(sqlite3 *db){
933 #ifndef SQLITE_OMIT_VIRTUALTABLE
934   int i;
935   sqlite3BtreeEnterAll(db);
936   for(i=0; i<db->nDb; i++){
937     Schema *pSchema = db->aDb[i].pSchema;
938     if( db->aDb[i].pSchema ){
939       HashElem *p;
940       for(p=sqliteHashFirst(&pSchema->tblHash); p; p=sqliteHashNext(p)){
941         Table *pTab = (Table *)sqliteHashData(p);
942         if( IsVirtual(pTab) ) sqlite3VtabDisconnect(db, pTab);
943       }
944     }
945   }
946   sqlite3VtabUnlockList(db);
947   sqlite3BtreeLeaveAll(db);
948 #else
949   UNUSED_PARAMETER(db);
950 #endif
951 }
952 
953 /*
954 ** Return TRUE if database connection db has unfinalized prepared
955 ** statements or unfinished sqlite3_backup objects.
956 */
957 static int connectionIsBusy(sqlite3 *db){
958   int j;
959   assert( sqlite3_mutex_held(db->mutex) );
960   if( db->pVdbe ) return 1;
961   for(j=0; j<db->nDb; j++){
962     Btree *pBt = db->aDb[j].pBt;
963     if( pBt && sqlite3BtreeIsInBackup(pBt) ) return 1;
964   }
965   return 0;
966 }
967 
968 /*
969 ** Close an existing SQLite database
970 */
971 static int sqlite3Close(sqlite3 *db, int forceZombie){
972   if( !db ){
973     /* EVIDENCE-OF: R-63257-11740 Calling sqlite3_close() or
974     ** sqlite3_close_v2() with a NULL pointer argument is a harmless no-op. */
975     return SQLITE_OK;
976   }
977   if( !sqlite3SafetyCheckSickOrOk(db) ){
978     return SQLITE_MISUSE_BKPT;
979   }
980   sqlite3_mutex_enter(db->mutex);
981 
982   /* Force xDisconnect calls on all virtual tables */
983   disconnectAllVtab(db);
984 
985   /* If a transaction is open, the disconnectAllVtab() call above
986   ** will not have called the xDisconnect() method on any virtual
987   ** tables in the db->aVTrans[] array. The following sqlite3VtabRollback()
988   ** call will do so. We need to do this before the check for active
989   ** SQL statements below, as the v-table implementation may be storing
990   ** some prepared statements internally.
991   */
992   sqlite3VtabRollback(db);
993 
994   /* Legacy behavior (sqlite3_close() behavior) is to return
995   ** SQLITE_BUSY if the connection can not be closed immediately.
996   */
997   if( !forceZombie && connectionIsBusy(db) ){
998     sqlite3ErrorWithMsg(db, SQLITE_BUSY, "unable to close due to unfinalized "
999        "statements or unfinished backups");
1000     sqlite3_mutex_leave(db->mutex);
1001     return SQLITE_BUSY;
1002   }
1003 
1004 #ifdef SQLITE_ENABLE_SQLLOG
1005   if( sqlite3GlobalConfig.xSqllog ){
1006     /* Closing the handle. Fourth parameter is passed the value 2. */
1007     sqlite3GlobalConfig.xSqllog(sqlite3GlobalConfig.pSqllogArg, db, 0, 2);
1008   }
1009 #endif
1010 
1011   /* Convert the connection into a zombie and then close it.
1012   */
1013   db->magic = SQLITE_MAGIC_ZOMBIE;
1014   sqlite3LeaveMutexAndCloseZombie(db);
1015   return SQLITE_OK;
1016 }
1017 
1018 /*
1019 ** Two variations on the public interface for closing a database
1020 ** connection. The sqlite3_close() version returns SQLITE_BUSY and
1021 ** leaves the connection option if there are unfinalized prepared
1022 ** statements or unfinished sqlite3_backups.  The sqlite3_close_v2()
1023 ** version forces the connection to become a zombie if there are
1024 ** unclosed resources, and arranges for deallocation when the last
1025 ** prepare statement or sqlite3_backup closes.
1026 */
1027 int sqlite3_close(sqlite3 *db){ return sqlite3Close(db,0); }
1028 int sqlite3_close_v2(sqlite3 *db){ return sqlite3Close(db,1); }
1029 
1030 
1031 /*
1032 ** Close the mutex on database connection db.
1033 **
1034 ** Furthermore, if database connection db is a zombie (meaning that there
1035 ** has been a prior call to sqlite3_close(db) or sqlite3_close_v2(db)) and
1036 ** every sqlite3_stmt has now been finalized and every sqlite3_backup has
1037 ** finished, then free all resources.
1038 */
1039 void sqlite3LeaveMutexAndCloseZombie(sqlite3 *db){
1040   HashElem *i;                    /* Hash table iterator */
1041   int j;
1042 
1043   /* If there are outstanding sqlite3_stmt or sqlite3_backup objects
1044   ** or if the connection has not yet been closed by sqlite3_close_v2(),
1045   ** then just leave the mutex and return.
1046   */
1047   if( db->magic!=SQLITE_MAGIC_ZOMBIE || connectionIsBusy(db) ){
1048     sqlite3_mutex_leave(db->mutex);
1049     return;
1050   }
1051 
1052   /* If we reach this point, it means that the database connection has
1053   ** closed all sqlite3_stmt and sqlite3_backup objects and has been
1054   ** passed to sqlite3_close (meaning that it is a zombie).  Therefore,
1055   ** go ahead and free all resources.
1056   */
1057 
1058   /* If a transaction is open, roll it back. This also ensures that if
1059   ** any database schemas have been modified by an uncommitted transaction
1060   ** they are reset. And that the required b-tree mutex is held to make
1061   ** the pager rollback and schema reset an atomic operation. */
1062   sqlite3RollbackAll(db, SQLITE_OK);
1063 
1064   /* Free any outstanding Savepoint structures. */
1065   sqlite3CloseSavepoints(db);
1066 
1067   /* Close all database connections */
1068   for(j=0; j<db->nDb; j++){
1069     struct Db *pDb = &db->aDb[j];
1070     if( pDb->pBt ){
1071       sqlite3BtreeClose(pDb->pBt);
1072       pDb->pBt = 0;
1073       if( j!=1 ){
1074         pDb->pSchema = 0;
1075       }
1076     }
1077   }
1078   /* Clear the TEMP schema separately and last */
1079   if( db->aDb[1].pSchema ){
1080     sqlite3SchemaClear(db->aDb[1].pSchema);
1081   }
1082   sqlite3VtabUnlockList(db);
1083 
1084   /* Free up the array of auxiliary databases */
1085   sqlite3CollapseDatabaseArray(db);
1086   assert( db->nDb<=2 );
1087   assert( db->aDb==db->aDbStatic );
1088 
1089   /* Tell the code in notify.c that the connection no longer holds any
1090   ** locks and does not require any further unlock-notify callbacks.
1091   */
1092   sqlite3ConnectionClosed(db);
1093 
1094   for(j=0; j<ArraySize(db->aFunc.a); j++){
1095     FuncDef *pNext, *pHash, *p;
1096     for(p=db->aFunc.a[j]; p; p=pHash){
1097       pHash = p->pHash;
1098       while( p ){
1099         functionDestroy(db, p);
1100         pNext = p->pNext;
1101         sqlite3DbFree(db, p);
1102         p = pNext;
1103       }
1104     }
1105   }
1106   for(i=sqliteHashFirst(&db->aCollSeq); i; i=sqliteHashNext(i)){
1107     CollSeq *pColl = (CollSeq *)sqliteHashData(i);
1108     /* Invoke any destructors registered for collation sequence user data. */
1109     for(j=0; j<3; j++){
1110       if( pColl[j].xDel ){
1111         pColl[j].xDel(pColl[j].pUser);
1112       }
1113     }
1114     sqlite3DbFree(db, pColl);
1115   }
1116   sqlite3HashClear(&db->aCollSeq);
1117 #ifndef SQLITE_OMIT_VIRTUALTABLE
1118   for(i=sqliteHashFirst(&db->aModule); i; i=sqliteHashNext(i)){
1119     Module *pMod = (Module *)sqliteHashData(i);
1120     if( pMod->xDestroy ){
1121       pMod->xDestroy(pMod->pAux);
1122     }
1123     sqlite3DbFree(db, pMod);
1124   }
1125   sqlite3HashClear(&db->aModule);
1126 #endif
1127 
1128   sqlite3Error(db, SQLITE_OK); /* Deallocates any cached error strings. */
1129   sqlite3ValueFree(db->pErr);
1130   sqlite3CloseExtensions(db);
1131 #if SQLITE_USER_AUTHENTICATION
1132   sqlite3_free(db->auth.zAuthUser);
1133   sqlite3_free(db->auth.zAuthPW);
1134 #endif
1135 
1136   db->magic = SQLITE_MAGIC_ERROR;
1137 
1138   /* The temp-database schema is allocated differently from the other schema
1139   ** objects (using sqliteMalloc() directly, instead of sqlite3BtreeSchema()).
1140   ** So it needs to be freed here. Todo: Why not roll the temp schema into
1141   ** the same sqliteMalloc() as the one that allocates the database
1142   ** structure?
1143   */
1144   sqlite3DbFree(db, db->aDb[1].pSchema);
1145   sqlite3_mutex_leave(db->mutex);
1146   db->magic = SQLITE_MAGIC_CLOSED;
1147   sqlite3_mutex_free(db->mutex);
1148   assert( db->lookaside.nOut==0 );  /* Fails on a lookaside memory leak */
1149   if( db->lookaside.bMalloced ){
1150     sqlite3_free(db->lookaside.pStart);
1151   }
1152   sqlite3_free(db);
1153 }
1154 
1155 /*
1156 ** Rollback all database files.  If tripCode is not SQLITE_OK, then
1157 ** any write cursors are invalidated ("tripped" - as in "tripping a circuit
1158 ** breaker") and made to return tripCode if there are any further
1159 ** attempts to use that cursor.  Read cursors remain open and valid
1160 ** but are "saved" in case the table pages are moved around.
1161 */
1162 void sqlite3RollbackAll(sqlite3 *db, int tripCode){
1163   int i;
1164   int inTrans = 0;
1165   int schemaChange;
1166   assert( sqlite3_mutex_held(db->mutex) );
1167   sqlite3BeginBenignMalloc();
1168 
1169   /* Obtain all b-tree mutexes before making any calls to BtreeRollback().
1170   ** This is important in case the transaction being rolled back has
1171   ** modified the database schema. If the b-tree mutexes are not taken
1172   ** here, then another shared-cache connection might sneak in between
1173   ** the database rollback and schema reset, which can cause false
1174   ** corruption reports in some cases.  */
1175   sqlite3BtreeEnterAll(db);
1176   schemaChange = (db->flags & SQLITE_InternChanges)!=0 && db->init.busy==0;
1177 
1178   for(i=0; i<db->nDb; i++){
1179     Btree *p = db->aDb[i].pBt;
1180     if( p ){
1181       if( sqlite3BtreeIsInTrans(p) ){
1182         inTrans = 1;
1183       }
1184       sqlite3BtreeRollback(p, tripCode, !schemaChange);
1185     }
1186   }
1187   sqlite3VtabRollback(db);
1188   sqlite3EndBenignMalloc();
1189 
1190   if( (db->flags&SQLITE_InternChanges)!=0 && db->init.busy==0 ){
1191     sqlite3ExpirePreparedStatements(db);
1192     sqlite3ResetAllSchemasOfConnection(db);
1193   }
1194   sqlite3BtreeLeaveAll(db);
1195 
1196   /* Any deferred constraint violations have now been resolved. */
1197   db->nDeferredCons = 0;
1198   db->nDeferredImmCons = 0;
1199   db->flags &= ~SQLITE_DeferFKs;
1200 
1201   /* If one has been configured, invoke the rollback-hook callback */
1202   if( db->xRollbackCallback && (inTrans || !db->autoCommit) ){
1203     db->xRollbackCallback(db->pRollbackArg);
1204   }
1205 }
1206 
1207 /*
1208 ** Return a static string containing the name corresponding to the error code
1209 ** specified in the argument.
1210 */
1211 #if defined(SQLITE_NEED_ERR_NAME)
1212 const char *sqlite3ErrName(int rc){
1213   const char *zName = 0;
1214   int i, origRc = rc;
1215   for(i=0; i<2 && zName==0; i++, rc &= 0xff){
1216     switch( rc ){
1217       case SQLITE_OK:                 zName = "SQLITE_OK";                break;
1218       case SQLITE_ERROR:              zName = "SQLITE_ERROR";             break;
1219       case SQLITE_INTERNAL:           zName = "SQLITE_INTERNAL";          break;
1220       case SQLITE_PERM:               zName = "SQLITE_PERM";              break;
1221       case SQLITE_ABORT:              zName = "SQLITE_ABORT";             break;
1222       case SQLITE_ABORT_ROLLBACK:     zName = "SQLITE_ABORT_ROLLBACK";    break;
1223       case SQLITE_BUSY:               zName = "SQLITE_BUSY";              break;
1224       case SQLITE_BUSY_RECOVERY:      zName = "SQLITE_BUSY_RECOVERY";     break;
1225       case SQLITE_BUSY_SNAPSHOT:      zName = "SQLITE_BUSY_SNAPSHOT";     break;
1226       case SQLITE_LOCKED:             zName = "SQLITE_LOCKED";            break;
1227       case SQLITE_LOCKED_SHAREDCACHE: zName = "SQLITE_LOCKED_SHAREDCACHE";break;
1228       case SQLITE_NOMEM:              zName = "SQLITE_NOMEM";             break;
1229       case SQLITE_READONLY:           zName = "SQLITE_READONLY";          break;
1230       case SQLITE_READONLY_RECOVERY:  zName = "SQLITE_READONLY_RECOVERY"; break;
1231       case SQLITE_READONLY_CANTLOCK:  zName = "SQLITE_READONLY_CANTLOCK"; break;
1232       case SQLITE_READONLY_ROLLBACK:  zName = "SQLITE_READONLY_ROLLBACK"; break;
1233       case SQLITE_READONLY_DBMOVED:   zName = "SQLITE_READONLY_DBMOVED";  break;
1234       case SQLITE_INTERRUPT:          zName = "SQLITE_INTERRUPT";         break;
1235       case SQLITE_IOERR:              zName = "SQLITE_IOERR";             break;
1236       case SQLITE_IOERR_READ:         zName = "SQLITE_IOERR_READ";        break;
1237       case SQLITE_IOERR_SHORT_READ:   zName = "SQLITE_IOERR_SHORT_READ";  break;
1238       case SQLITE_IOERR_WRITE:        zName = "SQLITE_IOERR_WRITE";       break;
1239       case SQLITE_IOERR_FSYNC:        zName = "SQLITE_IOERR_FSYNC";       break;
1240       case SQLITE_IOERR_DIR_FSYNC:    zName = "SQLITE_IOERR_DIR_FSYNC";   break;
1241       case SQLITE_IOERR_TRUNCATE:     zName = "SQLITE_IOERR_TRUNCATE";    break;
1242       case SQLITE_IOERR_FSTAT:        zName = "SQLITE_IOERR_FSTAT";       break;
1243       case SQLITE_IOERR_UNLOCK:       zName = "SQLITE_IOERR_UNLOCK";      break;
1244       case SQLITE_IOERR_RDLOCK:       zName = "SQLITE_IOERR_RDLOCK";      break;
1245       case SQLITE_IOERR_DELETE:       zName = "SQLITE_IOERR_DELETE";      break;
1246       case SQLITE_IOERR_NOMEM:        zName = "SQLITE_IOERR_NOMEM";       break;
1247       case SQLITE_IOERR_ACCESS:       zName = "SQLITE_IOERR_ACCESS";      break;
1248       case SQLITE_IOERR_CHECKRESERVEDLOCK:
1249                                 zName = "SQLITE_IOERR_CHECKRESERVEDLOCK"; break;
1250       case SQLITE_IOERR_LOCK:         zName = "SQLITE_IOERR_LOCK";        break;
1251       case SQLITE_IOERR_CLOSE:        zName = "SQLITE_IOERR_CLOSE";       break;
1252       case SQLITE_IOERR_DIR_CLOSE:    zName = "SQLITE_IOERR_DIR_CLOSE";   break;
1253       case SQLITE_IOERR_SHMOPEN:      zName = "SQLITE_IOERR_SHMOPEN";     break;
1254       case SQLITE_IOERR_SHMSIZE:      zName = "SQLITE_IOERR_SHMSIZE";     break;
1255       case SQLITE_IOERR_SHMLOCK:      zName = "SQLITE_IOERR_SHMLOCK";     break;
1256       case SQLITE_IOERR_SHMMAP:       zName = "SQLITE_IOERR_SHMMAP";      break;
1257       case SQLITE_IOERR_SEEK:         zName = "SQLITE_IOERR_SEEK";        break;
1258       case SQLITE_IOERR_DELETE_NOENT: zName = "SQLITE_IOERR_DELETE_NOENT";break;
1259       case SQLITE_IOERR_MMAP:         zName = "SQLITE_IOERR_MMAP";        break;
1260       case SQLITE_IOERR_GETTEMPPATH:  zName = "SQLITE_IOERR_GETTEMPPATH"; break;
1261       case SQLITE_IOERR_CONVPATH:     zName = "SQLITE_IOERR_CONVPATH";    break;
1262       case SQLITE_CORRUPT:            zName = "SQLITE_CORRUPT";           break;
1263       case SQLITE_CORRUPT_VTAB:       zName = "SQLITE_CORRUPT_VTAB";      break;
1264       case SQLITE_NOTFOUND:           zName = "SQLITE_NOTFOUND";          break;
1265       case SQLITE_FULL:               zName = "SQLITE_FULL";              break;
1266       case SQLITE_CANTOPEN:           zName = "SQLITE_CANTOPEN";          break;
1267       case SQLITE_CANTOPEN_NOTEMPDIR: zName = "SQLITE_CANTOPEN_NOTEMPDIR";break;
1268       case SQLITE_CANTOPEN_ISDIR:     zName = "SQLITE_CANTOPEN_ISDIR";    break;
1269       case SQLITE_CANTOPEN_FULLPATH:  zName = "SQLITE_CANTOPEN_FULLPATH"; break;
1270       case SQLITE_CANTOPEN_CONVPATH:  zName = "SQLITE_CANTOPEN_CONVPATH"; break;
1271       case SQLITE_PROTOCOL:           zName = "SQLITE_PROTOCOL";          break;
1272       case SQLITE_EMPTY:              zName = "SQLITE_EMPTY";             break;
1273       case SQLITE_SCHEMA:             zName = "SQLITE_SCHEMA";            break;
1274       case SQLITE_TOOBIG:             zName = "SQLITE_TOOBIG";            break;
1275       case SQLITE_CONSTRAINT:         zName = "SQLITE_CONSTRAINT";        break;
1276       case SQLITE_CONSTRAINT_UNIQUE:  zName = "SQLITE_CONSTRAINT_UNIQUE"; break;
1277       case SQLITE_CONSTRAINT_TRIGGER: zName = "SQLITE_CONSTRAINT_TRIGGER";break;
1278       case SQLITE_CONSTRAINT_FOREIGNKEY:
1279                                 zName = "SQLITE_CONSTRAINT_FOREIGNKEY";   break;
1280       case SQLITE_CONSTRAINT_CHECK:   zName = "SQLITE_CONSTRAINT_CHECK";  break;
1281       case SQLITE_CONSTRAINT_PRIMARYKEY:
1282                                 zName = "SQLITE_CONSTRAINT_PRIMARYKEY";   break;
1283       case SQLITE_CONSTRAINT_NOTNULL: zName = "SQLITE_CONSTRAINT_NOTNULL";break;
1284       case SQLITE_CONSTRAINT_COMMITHOOK:
1285                                 zName = "SQLITE_CONSTRAINT_COMMITHOOK";   break;
1286       case SQLITE_CONSTRAINT_VTAB:    zName = "SQLITE_CONSTRAINT_VTAB";   break;
1287       case SQLITE_CONSTRAINT_FUNCTION:
1288                                 zName = "SQLITE_CONSTRAINT_FUNCTION";     break;
1289       case SQLITE_CONSTRAINT_ROWID:   zName = "SQLITE_CONSTRAINT_ROWID";  break;
1290       case SQLITE_MISMATCH:           zName = "SQLITE_MISMATCH";          break;
1291       case SQLITE_MISUSE:             zName = "SQLITE_MISUSE";            break;
1292       case SQLITE_NOLFS:              zName = "SQLITE_NOLFS";             break;
1293       case SQLITE_AUTH:               zName = "SQLITE_AUTH";              break;
1294       case SQLITE_FORMAT:             zName = "SQLITE_FORMAT";            break;
1295       case SQLITE_RANGE:              zName = "SQLITE_RANGE";             break;
1296       case SQLITE_NOTADB:             zName = "SQLITE_NOTADB";            break;
1297       case SQLITE_ROW:                zName = "SQLITE_ROW";               break;
1298       case SQLITE_NOTICE:             zName = "SQLITE_NOTICE";            break;
1299       case SQLITE_NOTICE_RECOVER_WAL: zName = "SQLITE_NOTICE_RECOVER_WAL";break;
1300       case SQLITE_NOTICE_RECOVER_ROLLBACK:
1301                                 zName = "SQLITE_NOTICE_RECOVER_ROLLBACK"; break;
1302       case SQLITE_WARNING:            zName = "SQLITE_WARNING";           break;
1303       case SQLITE_WARNING_AUTOINDEX:  zName = "SQLITE_WARNING_AUTOINDEX"; break;
1304       case SQLITE_DONE:               zName = "SQLITE_DONE";              break;
1305     }
1306   }
1307   if( zName==0 ){
1308     static char zBuf[50];
1309     sqlite3_snprintf(sizeof(zBuf), zBuf, "SQLITE_UNKNOWN(%d)", origRc);
1310     zName = zBuf;
1311   }
1312   return zName;
1313 }
1314 #endif
1315 
1316 /*
1317 ** Return a static string that describes the kind of error specified in the
1318 ** argument.
1319 */
1320 const char *sqlite3ErrStr(int rc){
1321   static const char* const aMsg[] = {
1322     /* SQLITE_OK          */ "not an error",
1323     /* SQLITE_ERROR       */ "SQL logic error or missing database",
1324     /* SQLITE_INTERNAL    */ 0,
1325     /* SQLITE_PERM        */ "access permission denied",
1326     /* SQLITE_ABORT       */ "callback requested query abort",
1327     /* SQLITE_BUSY        */ "database is locked",
1328     /* SQLITE_LOCKED      */ "database table is locked",
1329     /* SQLITE_NOMEM       */ "out of memory",
1330     /* SQLITE_READONLY    */ "attempt to write a readonly database",
1331     /* SQLITE_INTERRUPT   */ "interrupted",
1332     /* SQLITE_IOERR       */ "disk I/O error",
1333     /* SQLITE_CORRUPT     */ "database disk image is malformed",
1334     /* SQLITE_NOTFOUND    */ "unknown operation",
1335     /* SQLITE_FULL        */ "database or disk is full",
1336     /* SQLITE_CANTOPEN    */ "unable to open database file",
1337     /* SQLITE_PROTOCOL    */ "locking protocol",
1338     /* SQLITE_EMPTY       */ "table contains no data",
1339     /* SQLITE_SCHEMA      */ "database schema has changed",
1340     /* SQLITE_TOOBIG      */ "string or blob too big",
1341     /* SQLITE_CONSTRAINT  */ "constraint failed",
1342     /* SQLITE_MISMATCH    */ "datatype mismatch",
1343     /* SQLITE_MISUSE      */ "library routine called out of sequence",
1344     /* SQLITE_NOLFS       */ "large file support is disabled",
1345     /* SQLITE_AUTH        */ "authorization denied",
1346     /* SQLITE_FORMAT      */ "auxiliary database format error",
1347     /* SQLITE_RANGE       */ "bind or column index out of range",
1348     /* SQLITE_NOTADB      */ "file is encrypted or is not a database",
1349   };
1350   const char *zErr = "unknown error";
1351   switch( rc ){
1352     case SQLITE_ABORT_ROLLBACK: {
1353       zErr = "abort due to ROLLBACK";
1354       break;
1355     }
1356     default: {
1357       rc &= 0xff;
1358       if( ALWAYS(rc>=0) && rc<ArraySize(aMsg) && aMsg[rc]!=0 ){
1359         zErr = aMsg[rc];
1360       }
1361       break;
1362     }
1363   }
1364   return zErr;
1365 }
1366 
1367 /*
1368 ** This routine implements a busy callback that sleeps and tries
1369 ** again until a timeout value is reached.  The timeout value is
1370 ** an integer number of milliseconds passed in as the first
1371 ** argument.
1372 */
1373 static int sqliteDefaultBusyCallback(
1374  void *ptr,               /* Database connection */
1375  int count                /* Number of times table has been busy */
1376 ){
1377 #if SQLITE_OS_WIN || HAVE_USLEEP
1378   static const u8 delays[] =
1379      { 1, 2, 5, 10, 15, 20, 25, 25,  25,  50,  50, 100 };
1380   static const u8 totals[] =
1381      { 0, 1, 3,  8, 18, 33, 53, 78, 103, 128, 178, 228 };
1382 # define NDELAY ArraySize(delays)
1383   sqlite3 *db = (sqlite3 *)ptr;
1384   int timeout = db->busyTimeout;
1385   int delay, prior;
1386 
1387   assert( count>=0 );
1388   if( count < NDELAY ){
1389     delay = delays[count];
1390     prior = totals[count];
1391   }else{
1392     delay = delays[NDELAY-1];
1393     prior = totals[NDELAY-1] + delay*(count-(NDELAY-1));
1394   }
1395   if( prior + delay > timeout ){
1396     delay = timeout - prior;
1397     if( delay<=0 ) return 0;
1398   }
1399   sqlite3OsSleep(db->pVfs, delay*1000);
1400   return 1;
1401 #else
1402   sqlite3 *db = (sqlite3 *)ptr;
1403   int timeout = ((sqlite3 *)ptr)->busyTimeout;
1404   if( (count+1)*1000 > timeout ){
1405     return 0;
1406   }
1407   sqlite3OsSleep(db->pVfs, 1000000);
1408   return 1;
1409 #endif
1410 }
1411 
1412 /*
1413 ** Invoke the given busy handler.
1414 **
1415 ** This routine is called when an operation failed with a lock.
1416 ** If this routine returns non-zero, the lock is retried.  If it
1417 ** returns 0, the operation aborts with an SQLITE_BUSY error.
1418 */
1419 int sqlite3InvokeBusyHandler(BusyHandler *p){
1420   int rc;
1421   if( NEVER(p==0) || p->xFunc==0 || p->nBusy<0 ) return 0;
1422   rc = p->xFunc(p->pArg, p->nBusy);
1423   if( rc==0 ){
1424     p->nBusy = -1;
1425   }else{
1426     p->nBusy++;
1427   }
1428   return rc;
1429 }
1430 
1431 /*
1432 ** This routine sets the busy callback for an Sqlite database to the
1433 ** given callback function with the given argument.
1434 */
1435 int sqlite3_busy_handler(
1436   sqlite3 *db,
1437   int (*xBusy)(void*,int),
1438   void *pArg
1439 ){
1440 #ifdef SQLITE_ENABLE_API_ARMOR
1441   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
1442 #endif
1443   sqlite3_mutex_enter(db->mutex);
1444   db->busyHandler.xFunc = xBusy;
1445   db->busyHandler.pArg = pArg;
1446   db->busyHandler.nBusy = 0;
1447   db->busyTimeout = 0;
1448   sqlite3_mutex_leave(db->mutex);
1449   return SQLITE_OK;
1450 }
1451 
1452 #ifndef SQLITE_OMIT_PROGRESS_CALLBACK
1453 /*
1454 ** This routine sets the progress callback for an Sqlite database to the
1455 ** given callback function with the given argument. The progress callback will
1456 ** be invoked every nOps opcodes.
1457 */
1458 void sqlite3_progress_handler(
1459   sqlite3 *db,
1460   int nOps,
1461   int (*xProgress)(void*),
1462   void *pArg
1463 ){
1464 #ifdef SQLITE_ENABLE_API_ARMOR
1465   if( !sqlite3SafetyCheckOk(db) ){
1466     (void)SQLITE_MISUSE_BKPT;
1467     return;
1468   }
1469 #endif
1470   sqlite3_mutex_enter(db->mutex);
1471   if( nOps>0 ){
1472     db->xProgress = xProgress;
1473     db->nProgressOps = (unsigned)nOps;
1474     db->pProgressArg = pArg;
1475   }else{
1476     db->xProgress = 0;
1477     db->nProgressOps = 0;
1478     db->pProgressArg = 0;
1479   }
1480   sqlite3_mutex_leave(db->mutex);
1481 }
1482 #endif
1483 
1484 
1485 /*
1486 ** This routine installs a default busy handler that waits for the
1487 ** specified number of milliseconds before returning 0.
1488 */
1489 int sqlite3_busy_timeout(sqlite3 *db, int ms){
1490 #ifdef SQLITE_ENABLE_API_ARMOR
1491   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
1492 #endif
1493   if( ms>0 ){
1494     sqlite3_busy_handler(db, sqliteDefaultBusyCallback, (void*)db);
1495     db->busyTimeout = ms;
1496   }else{
1497     sqlite3_busy_handler(db, 0, 0);
1498   }
1499   return SQLITE_OK;
1500 }
1501 
1502 /*
1503 ** Cause any pending operation to stop at its earliest opportunity.
1504 */
1505 void sqlite3_interrupt(sqlite3 *db){
1506 #ifdef SQLITE_ENABLE_API_ARMOR
1507   if( !sqlite3SafetyCheckOk(db) ){
1508     (void)SQLITE_MISUSE_BKPT;
1509     return;
1510   }
1511 #endif
1512   db->u1.isInterrupted = 1;
1513 }
1514 
1515 
1516 /*
1517 ** This function is exactly the same as sqlite3_create_function(), except
1518 ** that it is designed to be called by internal code. The difference is
1519 ** that if a malloc() fails in sqlite3_create_function(), an error code
1520 ** is returned and the mallocFailed flag cleared.
1521 */
1522 int sqlite3CreateFunc(
1523   sqlite3 *db,
1524   const char *zFunctionName,
1525   int nArg,
1526   int enc,
1527   void *pUserData,
1528   void (*xFunc)(sqlite3_context*,int,sqlite3_value **),
1529   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
1530   void (*xFinal)(sqlite3_context*),
1531   FuncDestructor *pDestructor
1532 ){
1533   FuncDef *p;
1534   int nName;
1535   int extraFlags;
1536 
1537   assert( sqlite3_mutex_held(db->mutex) );
1538   if( zFunctionName==0 ||
1539       (xFunc && (xFinal || xStep)) ||
1540       (!xFunc && (xFinal && !xStep)) ||
1541       (!xFunc && (!xFinal && xStep)) ||
1542       (nArg<-1 || nArg>SQLITE_MAX_FUNCTION_ARG) ||
1543       (255<(nName = sqlite3Strlen30( zFunctionName))) ){
1544     return SQLITE_MISUSE_BKPT;
1545   }
1546 
1547   assert( SQLITE_FUNC_CONSTANT==SQLITE_DETERMINISTIC );
1548   extraFlags = enc &  SQLITE_DETERMINISTIC;
1549   enc &= (SQLITE_FUNC_ENCMASK|SQLITE_ANY);
1550 
1551 #ifndef SQLITE_OMIT_UTF16
1552   /* If SQLITE_UTF16 is specified as the encoding type, transform this
1553   ** to one of SQLITE_UTF16LE or SQLITE_UTF16BE using the
1554   ** SQLITE_UTF16NATIVE macro. SQLITE_UTF16 is not used internally.
1555   **
1556   ** If SQLITE_ANY is specified, add three versions of the function
1557   ** to the hash table.
1558   */
1559   if( enc==SQLITE_UTF16 ){
1560     enc = SQLITE_UTF16NATIVE;
1561   }else if( enc==SQLITE_ANY ){
1562     int rc;
1563     rc = sqlite3CreateFunc(db, zFunctionName, nArg, SQLITE_UTF8|extraFlags,
1564          pUserData, xFunc, xStep, xFinal, pDestructor);
1565     if( rc==SQLITE_OK ){
1566       rc = sqlite3CreateFunc(db, zFunctionName, nArg, SQLITE_UTF16LE|extraFlags,
1567           pUserData, xFunc, xStep, xFinal, pDestructor);
1568     }
1569     if( rc!=SQLITE_OK ){
1570       return rc;
1571     }
1572     enc = SQLITE_UTF16BE;
1573   }
1574 #else
1575   enc = SQLITE_UTF8;
1576 #endif
1577 
1578   /* Check if an existing function is being overridden or deleted. If so,
1579   ** and there are active VMs, then return SQLITE_BUSY. If a function
1580   ** is being overridden/deleted but there are no active VMs, allow the
1581   ** operation to continue but invalidate all precompiled statements.
1582   */
1583   p = sqlite3FindFunction(db, zFunctionName, nName, nArg, (u8)enc, 0);
1584   if( p && (p->funcFlags & SQLITE_FUNC_ENCMASK)==enc && p->nArg==nArg ){
1585     if( db->nVdbeActive ){
1586       sqlite3ErrorWithMsg(db, SQLITE_BUSY,
1587         "unable to delete/modify user-function due to active statements");
1588       assert( !db->mallocFailed );
1589       return SQLITE_BUSY;
1590     }else{
1591       sqlite3ExpirePreparedStatements(db);
1592     }
1593   }
1594 
1595   p = sqlite3FindFunction(db, zFunctionName, nName, nArg, (u8)enc, 1);
1596   assert(p || db->mallocFailed);
1597   if( !p ){
1598     return SQLITE_NOMEM;
1599   }
1600 
1601   /* If an older version of the function with a configured destructor is
1602   ** being replaced invoke the destructor function here. */
1603   functionDestroy(db, p);
1604 
1605   if( pDestructor ){
1606     pDestructor->nRef++;
1607   }
1608   p->pDestructor = pDestructor;
1609   p->funcFlags = (p->funcFlags & SQLITE_FUNC_ENCMASK) | extraFlags;
1610   testcase( p->funcFlags & SQLITE_DETERMINISTIC );
1611   p->xFunc = xFunc;
1612   p->xStep = xStep;
1613   p->xFinalize = xFinal;
1614   p->pUserData = pUserData;
1615   p->nArg = (u16)nArg;
1616   return SQLITE_OK;
1617 }
1618 
1619 /*
1620 ** Create new user functions.
1621 */
1622 int sqlite3_create_function(
1623   sqlite3 *db,
1624   const char *zFunc,
1625   int nArg,
1626   int enc,
1627   void *p,
1628   void (*xFunc)(sqlite3_context*,int,sqlite3_value **),
1629   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
1630   void (*xFinal)(sqlite3_context*)
1631 ){
1632   return sqlite3_create_function_v2(db, zFunc, nArg, enc, p, xFunc, xStep,
1633                                     xFinal, 0);
1634 }
1635 
1636 int sqlite3_create_function_v2(
1637   sqlite3 *db,
1638   const char *zFunc,
1639   int nArg,
1640   int enc,
1641   void *p,
1642   void (*xFunc)(sqlite3_context*,int,sqlite3_value **),
1643   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
1644   void (*xFinal)(sqlite3_context*),
1645   void (*xDestroy)(void *)
1646 ){
1647   int rc = SQLITE_ERROR;
1648   FuncDestructor *pArg = 0;
1649 
1650 #ifdef SQLITE_ENABLE_API_ARMOR
1651   if( !sqlite3SafetyCheckOk(db) ){
1652     return SQLITE_MISUSE_BKPT;
1653   }
1654 #endif
1655   sqlite3_mutex_enter(db->mutex);
1656   if( xDestroy ){
1657     pArg = (FuncDestructor *)sqlite3DbMallocZero(db, sizeof(FuncDestructor));
1658     if( !pArg ){
1659       xDestroy(p);
1660       goto out;
1661     }
1662     pArg->xDestroy = xDestroy;
1663     pArg->pUserData = p;
1664   }
1665   rc = sqlite3CreateFunc(db, zFunc, nArg, enc, p, xFunc, xStep, xFinal, pArg);
1666   if( pArg && pArg->nRef==0 ){
1667     assert( rc!=SQLITE_OK );
1668     xDestroy(p);
1669     sqlite3DbFree(db, pArg);
1670   }
1671 
1672  out:
1673   rc = sqlite3ApiExit(db, rc);
1674   sqlite3_mutex_leave(db->mutex);
1675   return rc;
1676 }
1677 
1678 #ifndef SQLITE_OMIT_UTF16
1679 int sqlite3_create_function16(
1680   sqlite3 *db,
1681   const void *zFunctionName,
1682   int nArg,
1683   int eTextRep,
1684   void *p,
1685   void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
1686   void (*xStep)(sqlite3_context*,int,sqlite3_value**),
1687   void (*xFinal)(sqlite3_context*)
1688 ){
1689   int rc;
1690   char *zFunc8;
1691 
1692 #ifdef SQLITE_ENABLE_API_ARMOR
1693   if( !sqlite3SafetyCheckOk(db) || zFunctionName==0 ) return SQLITE_MISUSE_BKPT;
1694 #endif
1695   sqlite3_mutex_enter(db->mutex);
1696   assert( !db->mallocFailed );
1697   zFunc8 = sqlite3Utf16to8(db, zFunctionName, -1, SQLITE_UTF16NATIVE);
1698   rc = sqlite3CreateFunc(db, zFunc8, nArg, eTextRep, p, xFunc, xStep, xFinal,0);
1699   sqlite3DbFree(db, zFunc8);
1700   rc = sqlite3ApiExit(db, rc);
1701   sqlite3_mutex_leave(db->mutex);
1702   return rc;
1703 }
1704 #endif
1705 
1706 
1707 /*
1708 ** Declare that a function has been overloaded by a virtual table.
1709 **
1710 ** If the function already exists as a regular global function, then
1711 ** this routine is a no-op.  If the function does not exist, then create
1712 ** a new one that always throws a run-time error.
1713 **
1714 ** When virtual tables intend to provide an overloaded function, they
1715 ** should call this routine to make sure the global function exists.
1716 ** A global function must exist in order for name resolution to work
1717 ** properly.
1718 */
1719 int sqlite3_overload_function(
1720   sqlite3 *db,
1721   const char *zName,
1722   int nArg
1723 ){
1724   int nName = sqlite3Strlen30(zName);
1725   int rc = SQLITE_OK;
1726 
1727 #ifdef SQLITE_ENABLE_API_ARMOR
1728   if( !sqlite3SafetyCheckOk(db) || zName==0 || nArg<-2 ){
1729     return SQLITE_MISUSE_BKPT;
1730   }
1731 #endif
1732   sqlite3_mutex_enter(db->mutex);
1733   if( sqlite3FindFunction(db, zName, nName, nArg, SQLITE_UTF8, 0)==0 ){
1734     rc = sqlite3CreateFunc(db, zName, nArg, SQLITE_UTF8,
1735                            0, sqlite3InvalidFunction, 0, 0, 0);
1736   }
1737   rc = sqlite3ApiExit(db, rc);
1738   sqlite3_mutex_leave(db->mutex);
1739   return rc;
1740 }
1741 
1742 #ifndef SQLITE_OMIT_TRACE
1743 /*
1744 ** Register a trace function.  The pArg from the previously registered trace
1745 ** is returned.
1746 **
1747 ** A NULL trace function means that no tracing is executes.  A non-NULL
1748 ** trace is a pointer to a function that is invoked at the start of each
1749 ** SQL statement.
1750 */
1751 void *sqlite3_trace(sqlite3 *db, void (*xTrace)(void*,const char*), void *pArg){
1752   void *pOld;
1753 
1754 #ifdef SQLITE_ENABLE_API_ARMOR
1755   if( !sqlite3SafetyCheckOk(db) ){
1756     (void)SQLITE_MISUSE_BKPT;
1757     return 0;
1758   }
1759 #endif
1760   sqlite3_mutex_enter(db->mutex);
1761   pOld = db->pTraceArg;
1762   db->xTrace = xTrace;
1763   db->pTraceArg = pArg;
1764   sqlite3_mutex_leave(db->mutex);
1765   return pOld;
1766 }
1767 /*
1768 ** Register a profile function.  The pArg from the previously registered
1769 ** profile function is returned.
1770 **
1771 ** A NULL profile function means that no profiling is executes.  A non-NULL
1772 ** profile is a pointer to a function that is invoked at the conclusion of
1773 ** each SQL statement that is run.
1774 */
1775 void *sqlite3_profile(
1776   sqlite3 *db,
1777   void (*xProfile)(void*,const char*,sqlite_uint64),
1778   void *pArg
1779 ){
1780   void *pOld;
1781 
1782 #ifdef SQLITE_ENABLE_API_ARMOR
1783   if( !sqlite3SafetyCheckOk(db) ){
1784     (void)SQLITE_MISUSE_BKPT;
1785     return 0;
1786   }
1787 #endif
1788   sqlite3_mutex_enter(db->mutex);
1789   pOld = db->pProfileArg;
1790   db->xProfile = xProfile;
1791   db->pProfileArg = pArg;
1792   sqlite3_mutex_leave(db->mutex);
1793   return pOld;
1794 }
1795 #endif /* SQLITE_OMIT_TRACE */
1796 
1797 /*
1798 ** Register a function to be invoked when a transaction commits.
1799 ** If the invoked function returns non-zero, then the commit becomes a
1800 ** rollback.
1801 */
1802 void *sqlite3_commit_hook(
1803   sqlite3 *db,              /* Attach the hook to this database */
1804   int (*xCallback)(void*),  /* Function to invoke on each commit */
1805   void *pArg                /* Argument to the function */
1806 ){
1807   void *pOld;
1808 
1809 #ifdef SQLITE_ENABLE_API_ARMOR
1810   if( !sqlite3SafetyCheckOk(db) ){
1811     (void)SQLITE_MISUSE_BKPT;
1812     return 0;
1813   }
1814 #endif
1815   sqlite3_mutex_enter(db->mutex);
1816   pOld = db->pCommitArg;
1817   db->xCommitCallback = xCallback;
1818   db->pCommitArg = pArg;
1819   sqlite3_mutex_leave(db->mutex);
1820   return pOld;
1821 }
1822 
1823 /*
1824 ** Register a callback to be invoked each time a row is updated,
1825 ** inserted or deleted using this database connection.
1826 */
1827 void *sqlite3_update_hook(
1828   sqlite3 *db,              /* Attach the hook to this database */
1829   void (*xCallback)(void*,int,char const *,char const *,sqlite_int64),
1830   void *pArg                /* Argument to the function */
1831 ){
1832   void *pRet;
1833 
1834 #ifdef SQLITE_ENABLE_API_ARMOR
1835   if( !sqlite3SafetyCheckOk(db) ){
1836     (void)SQLITE_MISUSE_BKPT;
1837     return 0;
1838   }
1839 #endif
1840   sqlite3_mutex_enter(db->mutex);
1841   pRet = db->pUpdateArg;
1842   db->xUpdateCallback = xCallback;
1843   db->pUpdateArg = pArg;
1844   sqlite3_mutex_leave(db->mutex);
1845   return pRet;
1846 }
1847 
1848 /*
1849 ** Register a callback to be invoked each time a transaction is rolled
1850 ** back by this database connection.
1851 */
1852 void *sqlite3_rollback_hook(
1853   sqlite3 *db,              /* Attach the hook to this database */
1854   void (*xCallback)(void*), /* Callback function */
1855   void *pArg                /* Argument to the function */
1856 ){
1857   void *pRet;
1858 
1859 #ifdef SQLITE_ENABLE_API_ARMOR
1860   if( !sqlite3SafetyCheckOk(db) ){
1861     (void)SQLITE_MISUSE_BKPT;
1862     return 0;
1863   }
1864 #endif
1865   sqlite3_mutex_enter(db->mutex);
1866   pRet = db->pRollbackArg;
1867   db->xRollbackCallback = xCallback;
1868   db->pRollbackArg = pArg;
1869   sqlite3_mutex_leave(db->mutex);
1870   return pRet;
1871 }
1872 
1873 #ifndef SQLITE_OMIT_WAL
1874 /*
1875 ** The sqlite3_wal_hook() callback registered by sqlite3_wal_autocheckpoint().
1876 ** Invoke sqlite3_wal_checkpoint if the number of frames in the log file
1877 ** is greater than sqlite3.pWalArg cast to an integer (the value configured by
1878 ** wal_autocheckpoint()).
1879 */
1880 int sqlite3WalDefaultHook(
1881   void *pClientData,     /* Argument */
1882   sqlite3 *db,           /* Connection */
1883   const char *zDb,       /* Database */
1884   int nFrame             /* Size of WAL */
1885 ){
1886   if( nFrame>=SQLITE_PTR_TO_INT(pClientData) ){
1887     sqlite3BeginBenignMalloc();
1888     sqlite3_wal_checkpoint(db, zDb);
1889     sqlite3EndBenignMalloc();
1890   }
1891   return SQLITE_OK;
1892 }
1893 #endif /* SQLITE_OMIT_WAL */
1894 
1895 /*
1896 ** Configure an sqlite3_wal_hook() callback to automatically checkpoint
1897 ** a database after committing a transaction if there are nFrame or
1898 ** more frames in the log file. Passing zero or a negative value as the
1899 ** nFrame parameter disables automatic checkpoints entirely.
1900 **
1901 ** The callback registered by this function replaces any existing callback
1902 ** registered using sqlite3_wal_hook(). Likewise, registering a callback
1903 ** using sqlite3_wal_hook() disables the automatic checkpoint mechanism
1904 ** configured by this function.
1905 */
1906 int sqlite3_wal_autocheckpoint(sqlite3 *db, int nFrame){
1907 #ifdef SQLITE_OMIT_WAL
1908   UNUSED_PARAMETER(db);
1909   UNUSED_PARAMETER(nFrame);
1910 #else
1911 #ifdef SQLITE_ENABLE_API_ARMOR
1912   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
1913 #endif
1914   if( nFrame>0 ){
1915     sqlite3_wal_hook(db, sqlite3WalDefaultHook, SQLITE_INT_TO_PTR(nFrame));
1916   }else{
1917     sqlite3_wal_hook(db, 0, 0);
1918   }
1919 #endif
1920   return SQLITE_OK;
1921 }
1922 
1923 /*
1924 ** Register a callback to be invoked each time a transaction is written
1925 ** into the write-ahead-log by this database connection.
1926 */
1927 void *sqlite3_wal_hook(
1928   sqlite3 *db,                    /* Attach the hook to this db handle */
1929   int(*xCallback)(void *, sqlite3*, const char*, int),
1930   void *pArg                      /* First argument passed to xCallback() */
1931 ){
1932 #ifndef SQLITE_OMIT_WAL
1933   void *pRet;
1934 #ifdef SQLITE_ENABLE_API_ARMOR
1935   if( !sqlite3SafetyCheckOk(db) ){
1936     (void)SQLITE_MISUSE_BKPT;
1937     return 0;
1938   }
1939 #endif
1940   sqlite3_mutex_enter(db->mutex);
1941   pRet = db->pWalArg;
1942   db->xWalCallback = xCallback;
1943   db->pWalArg = pArg;
1944   sqlite3_mutex_leave(db->mutex);
1945   return pRet;
1946 #else
1947   return 0;
1948 #endif
1949 }
1950 
1951 /*
1952 ** Checkpoint database zDb.
1953 */
1954 int sqlite3_wal_checkpoint_v2(
1955   sqlite3 *db,                    /* Database handle */
1956   const char *zDb,                /* Name of attached database (or NULL) */
1957   int eMode,                      /* SQLITE_CHECKPOINT_* value */
1958   int *pnLog,                     /* OUT: Size of WAL log in frames */
1959   int *pnCkpt                     /* OUT: Total number of frames checkpointed */
1960 ){
1961 #ifdef SQLITE_OMIT_WAL
1962   return SQLITE_OK;
1963 #else
1964   int rc;                         /* Return code */
1965   int iDb = SQLITE_MAX_ATTACHED;  /* sqlite3.aDb[] index of db to checkpoint */
1966 
1967 #ifdef SQLITE_ENABLE_API_ARMOR
1968   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
1969 #endif
1970 
1971   /* Initialize the output variables to -1 in case an error occurs. */
1972   if( pnLog ) *pnLog = -1;
1973   if( pnCkpt ) *pnCkpt = -1;
1974 
1975   assert( SQLITE_CHECKPOINT_PASSIVE==0 );
1976   assert( SQLITE_CHECKPOINT_FULL==1 );
1977   assert( SQLITE_CHECKPOINT_RESTART==2 );
1978   assert( SQLITE_CHECKPOINT_TRUNCATE==3 );
1979   if( eMode<SQLITE_CHECKPOINT_PASSIVE || eMode>SQLITE_CHECKPOINT_TRUNCATE ){
1980     /* EVIDENCE-OF: R-03996-12088 The M parameter must be a valid checkpoint
1981     ** mode: */
1982     return SQLITE_MISUSE;
1983   }
1984 
1985   sqlite3_mutex_enter(db->mutex);
1986   if( zDb && zDb[0] ){
1987     iDb = sqlite3FindDbName(db, zDb);
1988   }
1989   if( iDb<0 ){
1990     rc = SQLITE_ERROR;
1991     sqlite3ErrorWithMsg(db, SQLITE_ERROR, "unknown database: %s", zDb);
1992   }else{
1993     db->busyHandler.nBusy = 0;
1994     rc = sqlite3Checkpoint(db, iDb, eMode, pnLog, pnCkpt);
1995     sqlite3Error(db, rc);
1996   }
1997   rc = sqlite3ApiExit(db, rc);
1998   sqlite3_mutex_leave(db->mutex);
1999   return rc;
2000 #endif
2001 }
2002 
2003 
2004 /*
2005 ** Checkpoint database zDb. If zDb is NULL, or if the buffer zDb points
2006 ** to contains a zero-length string, all attached databases are
2007 ** checkpointed.
2008 */
2009 int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb){
2010   /* EVIDENCE-OF: R-41613-20553 The sqlite3_wal_checkpoint(D,X) is equivalent to
2011   ** sqlite3_wal_checkpoint_v2(D,X,SQLITE_CHECKPOINT_PASSIVE,0,0). */
2012   return sqlite3_wal_checkpoint_v2(db,zDb,SQLITE_CHECKPOINT_PASSIVE,0,0);
2013 }
2014 
2015 #ifndef SQLITE_OMIT_WAL
2016 /*
2017 ** Run a checkpoint on database iDb. This is a no-op if database iDb is
2018 ** not currently open in WAL mode.
2019 **
2020 ** If a transaction is open on the database being checkpointed, this
2021 ** function returns SQLITE_LOCKED and a checkpoint is not attempted. If
2022 ** an error occurs while running the checkpoint, an SQLite error code is
2023 ** returned (i.e. SQLITE_IOERR). Otherwise, SQLITE_OK.
2024 **
2025 ** The mutex on database handle db should be held by the caller. The mutex
2026 ** associated with the specific b-tree being checkpointed is taken by
2027 ** this function while the checkpoint is running.
2028 **
2029 ** If iDb is passed SQLITE_MAX_ATTACHED, then all attached databases are
2030 ** checkpointed. If an error is encountered it is returned immediately -
2031 ** no attempt is made to checkpoint any remaining databases.
2032 **
2033 ** Parameter eMode is one of SQLITE_CHECKPOINT_PASSIVE, FULL or RESTART.
2034 */
2035 int sqlite3Checkpoint(sqlite3 *db, int iDb, int eMode, int *pnLog, int *pnCkpt){
2036   int rc = SQLITE_OK;             /* Return code */
2037   int i;                          /* Used to iterate through attached dbs */
2038   int bBusy = 0;                  /* True if SQLITE_BUSY has been encountered */
2039 
2040   assert( sqlite3_mutex_held(db->mutex) );
2041   assert( !pnLog || *pnLog==-1 );
2042   assert( !pnCkpt || *pnCkpt==-1 );
2043 
2044   for(i=0; i<db->nDb && rc==SQLITE_OK; i++){
2045     if( i==iDb || iDb==SQLITE_MAX_ATTACHED ){
2046       rc = sqlite3BtreeCheckpoint(db->aDb[i].pBt, eMode, pnLog, pnCkpt);
2047       pnLog = 0;
2048       pnCkpt = 0;
2049       if( rc==SQLITE_BUSY ){
2050         bBusy = 1;
2051         rc = SQLITE_OK;
2052       }
2053     }
2054   }
2055 
2056   return (rc==SQLITE_OK && bBusy) ? SQLITE_BUSY : rc;
2057 }
2058 #endif /* SQLITE_OMIT_WAL */
2059 
2060 /*
2061 ** This function returns true if main-memory should be used instead of
2062 ** a temporary file for transient pager files and statement journals.
2063 ** The value returned depends on the value of db->temp_store (runtime
2064 ** parameter) and the compile time value of SQLITE_TEMP_STORE. The
2065 ** following table describes the relationship between these two values
2066 ** and this functions return value.
2067 **
2068 **   SQLITE_TEMP_STORE     db->temp_store     Location of temporary database
2069 **   -----------------     --------------     ------------------------------
2070 **   0                     any                file      (return 0)
2071 **   1                     1                  file      (return 0)
2072 **   1                     2                  memory    (return 1)
2073 **   1                     0                  file      (return 0)
2074 **   2                     1                  file      (return 0)
2075 **   2                     2                  memory    (return 1)
2076 **   2                     0                  memory    (return 1)
2077 **   3                     any                memory    (return 1)
2078 */
2079 int sqlite3TempInMemory(const sqlite3 *db){
2080 #if SQLITE_TEMP_STORE==1
2081   return ( db->temp_store==2 );
2082 #endif
2083 #if SQLITE_TEMP_STORE==2
2084   return ( db->temp_store!=1 );
2085 #endif
2086 #if SQLITE_TEMP_STORE==3
2087   UNUSED_PARAMETER(db);
2088   return 1;
2089 #endif
2090 #if SQLITE_TEMP_STORE<1 || SQLITE_TEMP_STORE>3
2091   UNUSED_PARAMETER(db);
2092   return 0;
2093 #endif
2094 }
2095 
2096 /*
2097 ** Return UTF-8 encoded English language explanation of the most recent
2098 ** error.
2099 */
2100 const char *sqlite3_errmsg(sqlite3 *db){
2101   const char *z;
2102   if( !db ){
2103     return sqlite3ErrStr(SQLITE_NOMEM);
2104   }
2105   if( !sqlite3SafetyCheckSickOrOk(db) ){
2106     return sqlite3ErrStr(SQLITE_MISUSE_BKPT);
2107   }
2108   sqlite3_mutex_enter(db->mutex);
2109   if( db->mallocFailed ){
2110     z = sqlite3ErrStr(SQLITE_NOMEM);
2111   }else{
2112     testcase( db->pErr==0 );
2113     z = (char*)sqlite3_value_text(db->pErr);
2114     assert( !db->mallocFailed );
2115     if( z==0 ){
2116       z = sqlite3ErrStr(db->errCode);
2117     }
2118   }
2119   sqlite3_mutex_leave(db->mutex);
2120   return z;
2121 }
2122 
2123 #ifndef SQLITE_OMIT_UTF16
2124 /*
2125 ** Return UTF-16 encoded English language explanation of the most recent
2126 ** error.
2127 */
2128 const void *sqlite3_errmsg16(sqlite3 *db){
2129   static const u16 outOfMem[] = {
2130     'o', 'u', 't', ' ', 'o', 'f', ' ', 'm', 'e', 'm', 'o', 'r', 'y', 0
2131   };
2132   static const u16 misuse[] = {
2133     'l', 'i', 'b', 'r', 'a', 'r', 'y', ' ',
2134     'r', 'o', 'u', 't', 'i', 'n', 'e', ' ',
2135     'c', 'a', 'l', 'l', 'e', 'd', ' ',
2136     'o', 'u', 't', ' ',
2137     'o', 'f', ' ',
2138     's', 'e', 'q', 'u', 'e', 'n', 'c', 'e', 0
2139   };
2140 
2141   const void *z;
2142   if( !db ){
2143     return (void *)outOfMem;
2144   }
2145   if( !sqlite3SafetyCheckSickOrOk(db) ){
2146     return (void *)misuse;
2147   }
2148   sqlite3_mutex_enter(db->mutex);
2149   if( db->mallocFailed ){
2150     z = (void *)outOfMem;
2151   }else{
2152     z = sqlite3_value_text16(db->pErr);
2153     if( z==0 ){
2154       sqlite3ErrorWithMsg(db, db->errCode, sqlite3ErrStr(db->errCode));
2155       z = sqlite3_value_text16(db->pErr);
2156     }
2157     /* A malloc() may have failed within the call to sqlite3_value_text16()
2158     ** above. If this is the case, then the db->mallocFailed flag needs to
2159     ** be cleared before returning. Do this directly, instead of via
2160     ** sqlite3ApiExit(), to avoid setting the database handle error message.
2161     */
2162     db->mallocFailed = 0;
2163   }
2164   sqlite3_mutex_leave(db->mutex);
2165   return z;
2166 }
2167 #endif /* SQLITE_OMIT_UTF16 */
2168 
2169 /*
2170 ** Return the most recent error code generated by an SQLite routine. If NULL is
2171 ** passed to this function, we assume a malloc() failed during sqlite3_open().
2172 */
2173 int sqlite3_errcode(sqlite3 *db){
2174   if( db && !sqlite3SafetyCheckSickOrOk(db) ){
2175     return SQLITE_MISUSE_BKPT;
2176   }
2177   if( !db || db->mallocFailed ){
2178     return SQLITE_NOMEM;
2179   }
2180   return db->errCode & db->errMask;
2181 }
2182 int sqlite3_extended_errcode(sqlite3 *db){
2183   if( db && !sqlite3SafetyCheckSickOrOk(db) ){
2184     return SQLITE_MISUSE_BKPT;
2185   }
2186   if( !db || db->mallocFailed ){
2187     return SQLITE_NOMEM;
2188   }
2189   return db->errCode;
2190 }
2191 
2192 /*
2193 ** Return a string that describes the kind of error specified in the
2194 ** argument.  For now, this simply calls the internal sqlite3ErrStr()
2195 ** function.
2196 */
2197 const char *sqlite3_errstr(int rc){
2198   return sqlite3ErrStr(rc);
2199 }
2200 
2201 /*
2202 ** Create a new collating function for database "db".  The name is zName
2203 ** and the encoding is enc.
2204 */
2205 static int createCollation(
2206   sqlite3* db,
2207   const char *zName,
2208   u8 enc,
2209   void* pCtx,
2210   int(*xCompare)(void*,int,const void*,int,const void*),
2211   void(*xDel)(void*)
2212 ){
2213   CollSeq *pColl;
2214   int enc2;
2215 
2216   assert( sqlite3_mutex_held(db->mutex) );
2217 
2218   /* If SQLITE_UTF16 is specified as the encoding type, transform this
2219   ** to one of SQLITE_UTF16LE or SQLITE_UTF16BE using the
2220   ** SQLITE_UTF16NATIVE macro. SQLITE_UTF16 is not used internally.
2221   */
2222   enc2 = enc;
2223   testcase( enc2==SQLITE_UTF16 );
2224   testcase( enc2==SQLITE_UTF16_ALIGNED );
2225   if( enc2==SQLITE_UTF16 || enc2==SQLITE_UTF16_ALIGNED ){
2226     enc2 = SQLITE_UTF16NATIVE;
2227   }
2228   if( enc2<SQLITE_UTF8 || enc2>SQLITE_UTF16BE ){
2229     return SQLITE_MISUSE_BKPT;
2230   }
2231 
2232   /* Check if this call is removing or replacing an existing collation
2233   ** sequence. If so, and there are active VMs, return busy. If there
2234   ** are no active VMs, invalidate any pre-compiled statements.
2235   */
2236   pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, 0);
2237   if( pColl && pColl->xCmp ){
2238     if( db->nVdbeActive ){
2239       sqlite3ErrorWithMsg(db, SQLITE_BUSY,
2240         "unable to delete/modify collation sequence due to active statements");
2241       return SQLITE_BUSY;
2242     }
2243     sqlite3ExpirePreparedStatements(db);
2244 
2245     /* If collation sequence pColl was created directly by a call to
2246     ** sqlite3_create_collation, and not generated by synthCollSeq(),
2247     ** then any copies made by synthCollSeq() need to be invalidated.
2248     ** Also, collation destructor - CollSeq.xDel() - function may need
2249     ** to be called.
2250     */
2251     if( (pColl->enc & ~SQLITE_UTF16_ALIGNED)==enc2 ){
2252       CollSeq *aColl = sqlite3HashFind(&db->aCollSeq, zName);
2253       int j;
2254       for(j=0; j<3; j++){
2255         CollSeq *p = &aColl[j];
2256         if( p->enc==pColl->enc ){
2257           if( p->xDel ){
2258             p->xDel(p->pUser);
2259           }
2260           p->xCmp = 0;
2261         }
2262       }
2263     }
2264   }
2265 
2266   pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, 1);
2267   if( pColl==0 ) return SQLITE_NOMEM;
2268   pColl->xCmp = xCompare;
2269   pColl->pUser = pCtx;
2270   pColl->xDel = xDel;
2271   pColl->enc = (u8)(enc2 | (enc & SQLITE_UTF16_ALIGNED));
2272   sqlite3Error(db, SQLITE_OK);
2273   return SQLITE_OK;
2274 }
2275 
2276 
2277 /*
2278 ** This array defines hard upper bounds on limit values.  The
2279 ** initializer must be kept in sync with the SQLITE_LIMIT_*
2280 ** #defines in sqlite3.h.
2281 */
2282 static const int aHardLimit[] = {
2283   SQLITE_MAX_LENGTH,
2284   SQLITE_MAX_SQL_LENGTH,
2285   SQLITE_MAX_COLUMN,
2286   SQLITE_MAX_EXPR_DEPTH,
2287   SQLITE_MAX_COMPOUND_SELECT,
2288   SQLITE_MAX_VDBE_OP,
2289   SQLITE_MAX_FUNCTION_ARG,
2290   SQLITE_MAX_ATTACHED,
2291   SQLITE_MAX_LIKE_PATTERN_LENGTH,
2292   SQLITE_MAX_VARIABLE_NUMBER,      /* IMP: R-38091-32352 */
2293   SQLITE_MAX_TRIGGER_DEPTH,
2294   SQLITE_MAX_WORKER_THREADS,
2295 };
2296 
2297 /*
2298 ** Make sure the hard limits are set to reasonable values
2299 */
2300 #if SQLITE_MAX_LENGTH<100
2301 # error SQLITE_MAX_LENGTH must be at least 100
2302 #endif
2303 #if SQLITE_MAX_SQL_LENGTH<100
2304 # error SQLITE_MAX_SQL_LENGTH must be at least 100
2305 #endif
2306 #if SQLITE_MAX_SQL_LENGTH>SQLITE_MAX_LENGTH
2307 # error SQLITE_MAX_SQL_LENGTH must not be greater than SQLITE_MAX_LENGTH
2308 #endif
2309 #if SQLITE_MAX_COMPOUND_SELECT<2
2310 # error SQLITE_MAX_COMPOUND_SELECT must be at least 2
2311 #endif
2312 #if SQLITE_MAX_VDBE_OP<40
2313 # error SQLITE_MAX_VDBE_OP must be at least 40
2314 #endif
2315 #if SQLITE_MAX_FUNCTION_ARG<0 || SQLITE_MAX_FUNCTION_ARG>1000
2316 # error SQLITE_MAX_FUNCTION_ARG must be between 0 and 1000
2317 #endif
2318 #if SQLITE_MAX_ATTACHED<0 || SQLITE_MAX_ATTACHED>125
2319 # error SQLITE_MAX_ATTACHED must be between 0 and 125
2320 #endif
2321 #if SQLITE_MAX_LIKE_PATTERN_LENGTH<1
2322 # error SQLITE_MAX_LIKE_PATTERN_LENGTH must be at least 1
2323 #endif
2324 #if SQLITE_MAX_COLUMN>32767
2325 # error SQLITE_MAX_COLUMN must not exceed 32767
2326 #endif
2327 #if SQLITE_MAX_TRIGGER_DEPTH<1
2328 # error SQLITE_MAX_TRIGGER_DEPTH must be at least 1
2329 #endif
2330 #if SQLITE_MAX_WORKER_THREADS<0 || SQLITE_MAX_WORKER_THREADS>50
2331 # error SQLITE_MAX_WORKER_THREADS must be between 0 and 50
2332 #endif
2333 
2334 
2335 /*
2336 ** Change the value of a limit.  Report the old value.
2337 ** If an invalid limit index is supplied, report -1.
2338 ** Make no changes but still report the old value if the
2339 ** new limit is negative.
2340 **
2341 ** A new lower limit does not shrink existing constructs.
2342 ** It merely prevents new constructs that exceed the limit
2343 ** from forming.
2344 */
2345 int sqlite3_limit(sqlite3 *db, int limitId, int newLimit){
2346   int oldLimit;
2347 
2348 #ifdef SQLITE_ENABLE_API_ARMOR
2349   if( !sqlite3SafetyCheckOk(db) ){
2350     (void)SQLITE_MISUSE_BKPT;
2351     return -1;
2352   }
2353 #endif
2354 
2355   /* EVIDENCE-OF: R-30189-54097 For each limit category SQLITE_LIMIT_NAME
2356   ** there is a hard upper bound set at compile-time by a C preprocessor
2357   ** macro called SQLITE_MAX_NAME. (The "_LIMIT_" in the name is changed to
2358   ** "_MAX_".)
2359   */
2360   assert( aHardLimit[SQLITE_LIMIT_LENGTH]==SQLITE_MAX_LENGTH );
2361   assert( aHardLimit[SQLITE_LIMIT_SQL_LENGTH]==SQLITE_MAX_SQL_LENGTH );
2362   assert( aHardLimit[SQLITE_LIMIT_COLUMN]==SQLITE_MAX_COLUMN );
2363   assert( aHardLimit[SQLITE_LIMIT_EXPR_DEPTH]==SQLITE_MAX_EXPR_DEPTH );
2364   assert( aHardLimit[SQLITE_LIMIT_COMPOUND_SELECT]==SQLITE_MAX_COMPOUND_SELECT);
2365   assert( aHardLimit[SQLITE_LIMIT_VDBE_OP]==SQLITE_MAX_VDBE_OP );
2366   assert( aHardLimit[SQLITE_LIMIT_FUNCTION_ARG]==SQLITE_MAX_FUNCTION_ARG );
2367   assert( aHardLimit[SQLITE_LIMIT_ATTACHED]==SQLITE_MAX_ATTACHED );
2368   assert( aHardLimit[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]==
2369                                                SQLITE_MAX_LIKE_PATTERN_LENGTH );
2370   assert( aHardLimit[SQLITE_LIMIT_VARIABLE_NUMBER]==SQLITE_MAX_VARIABLE_NUMBER);
2371   assert( aHardLimit[SQLITE_LIMIT_TRIGGER_DEPTH]==SQLITE_MAX_TRIGGER_DEPTH );
2372   assert( aHardLimit[SQLITE_LIMIT_WORKER_THREADS]==SQLITE_MAX_WORKER_THREADS );
2373   assert( SQLITE_LIMIT_WORKER_THREADS==(SQLITE_N_LIMIT-1) );
2374 
2375 
2376   if( limitId<0 || limitId>=SQLITE_N_LIMIT ){
2377     return -1;
2378   }
2379   oldLimit = db->aLimit[limitId];
2380   if( newLimit>=0 ){                   /* IMP: R-52476-28732 */
2381     if( newLimit>aHardLimit[limitId] ){
2382       newLimit = aHardLimit[limitId];  /* IMP: R-51463-25634 */
2383     }
2384     db->aLimit[limitId] = newLimit;
2385   }
2386   return oldLimit;                     /* IMP: R-53341-35419 */
2387 }
2388 
2389 /*
2390 ** This function is used to parse both URIs and non-URI filenames passed by the
2391 ** user to API functions sqlite3_open() or sqlite3_open_v2(), and for database
2392 ** URIs specified as part of ATTACH statements.
2393 **
2394 ** The first argument to this function is the name of the VFS to use (or
2395 ** a NULL to signify the default VFS) if the URI does not contain a "vfs=xxx"
2396 ** query parameter. The second argument contains the URI (or non-URI filename)
2397 ** itself. When this function is called the *pFlags variable should contain
2398 ** the default flags to open the database handle with. The value stored in
2399 ** *pFlags may be updated before returning if the URI filename contains
2400 ** "cache=xxx" or "mode=xxx" query parameters.
2401 **
2402 ** If successful, SQLITE_OK is returned. In this case *ppVfs is set to point to
2403 ** the VFS that should be used to open the database file. *pzFile is set to
2404 ** point to a buffer containing the name of the file to open. It is the
2405 ** responsibility of the caller to eventually call sqlite3_free() to release
2406 ** this buffer.
2407 **
2408 ** If an error occurs, then an SQLite error code is returned and *pzErrMsg
2409 ** may be set to point to a buffer containing an English language error
2410 ** message. It is the responsibility of the caller to eventually release
2411 ** this buffer by calling sqlite3_free().
2412 */
2413 int sqlite3ParseUri(
2414   const char *zDefaultVfs,        /* VFS to use if no "vfs=xxx" query option */
2415   const char *zUri,               /* Nul-terminated URI to parse */
2416   unsigned int *pFlags,           /* IN/OUT: SQLITE_OPEN_XXX flags */
2417   sqlite3_vfs **ppVfs,            /* OUT: VFS to use */
2418   char **pzFile,                  /* OUT: Filename component of URI */
2419   char **pzErrMsg                 /* OUT: Error message (if rc!=SQLITE_OK) */
2420 ){
2421   int rc = SQLITE_OK;
2422   unsigned int flags = *pFlags;
2423   const char *zVfs = zDefaultVfs;
2424   char *zFile;
2425   char c;
2426   int nUri = sqlite3Strlen30(zUri);
2427 
2428   assert( *pzErrMsg==0 );
2429 
2430   if( ((flags & SQLITE_OPEN_URI)             /* IMP: R-48725-32206 */
2431             || sqlite3GlobalConfig.bOpenUri) /* IMP: R-51689-46548 */
2432    && nUri>=5 && memcmp(zUri, "file:", 5)==0 /* IMP: R-57884-37496 */
2433   ){
2434     char *zOpt;
2435     int eState;                   /* Parser state when parsing URI */
2436     int iIn;                      /* Input character index */
2437     int iOut = 0;                 /* Output character index */
2438     u64 nByte = nUri+2;           /* Bytes of space to allocate */
2439 
2440     /* Make sure the SQLITE_OPEN_URI flag is set to indicate to the VFS xOpen
2441     ** method that there may be extra parameters following the file-name.  */
2442     flags |= SQLITE_OPEN_URI;
2443 
2444     for(iIn=0; iIn<nUri; iIn++) nByte += (zUri[iIn]=='&');
2445     zFile = sqlite3_malloc64(nByte);
2446     if( !zFile ) return SQLITE_NOMEM;
2447 
2448     iIn = 5;
2449 #ifdef SQLITE_ALLOW_URI_AUTHORITY
2450     if( strncmp(zUri+5, "///", 3)==0 ){
2451       iIn = 7;
2452       /* The following condition causes URIs with five leading / characters
2453       ** like file://///host/path to be converted into UNCs like //host/path.
2454       ** The correct URI for that UNC has only two or four leading / characters
2455       ** file://host/path or file:////host/path.  But 5 leading slashes is a
2456       ** common error, we are told, so we handle it as a special case. */
2457       if( strncmp(zUri+7, "///", 3)==0 ){ iIn++; }
2458     }else if( strncmp(zUri+5, "//localhost/", 12)==0 ){
2459       iIn = 16;
2460     }
2461 #else
2462     /* Discard the scheme and authority segments of the URI. */
2463     if( zUri[5]=='/' && zUri[6]=='/' ){
2464       iIn = 7;
2465       while( zUri[iIn] && zUri[iIn]!='/' ) iIn++;
2466       if( iIn!=7 && (iIn!=16 || memcmp("localhost", &zUri[7], 9)) ){
2467         *pzErrMsg = sqlite3_mprintf("invalid uri authority: %.*s",
2468             iIn-7, &zUri[7]);
2469         rc = SQLITE_ERROR;
2470         goto parse_uri_out;
2471       }
2472     }
2473 #endif
2474 
2475     /* Copy the filename and any query parameters into the zFile buffer.
2476     ** Decode %HH escape codes along the way.
2477     **
2478     ** Within this loop, variable eState may be set to 0, 1 or 2, depending
2479     ** on the parsing context. As follows:
2480     **
2481     **   0: Parsing file-name.
2482     **   1: Parsing name section of a name=value query parameter.
2483     **   2: Parsing value section of a name=value query parameter.
2484     */
2485     eState = 0;
2486     while( (c = zUri[iIn])!=0 && c!='#' ){
2487       iIn++;
2488       if( c=='%'
2489        && sqlite3Isxdigit(zUri[iIn])
2490        && sqlite3Isxdigit(zUri[iIn+1])
2491       ){
2492         int octet = (sqlite3HexToInt(zUri[iIn++]) << 4);
2493         octet += sqlite3HexToInt(zUri[iIn++]);
2494 
2495         assert( octet>=0 && octet<256 );
2496         if( octet==0 ){
2497           /* This branch is taken when "%00" appears within the URI. In this
2498           ** case we ignore all text in the remainder of the path, name or
2499           ** value currently being parsed. So ignore the current character
2500           ** and skip to the next "?", "=" or "&", as appropriate. */
2501           while( (c = zUri[iIn])!=0 && c!='#'
2502               && (eState!=0 || c!='?')
2503               && (eState!=1 || (c!='=' && c!='&'))
2504               && (eState!=2 || c!='&')
2505           ){
2506             iIn++;
2507           }
2508           continue;
2509         }
2510         c = octet;
2511       }else if( eState==1 && (c=='&' || c=='=') ){
2512         if( zFile[iOut-1]==0 ){
2513           /* An empty option name. Ignore this option altogether. */
2514           while( zUri[iIn] && zUri[iIn]!='#' && zUri[iIn-1]!='&' ) iIn++;
2515           continue;
2516         }
2517         if( c=='&' ){
2518           zFile[iOut++] = '\0';
2519         }else{
2520           eState = 2;
2521         }
2522         c = 0;
2523       }else if( (eState==0 && c=='?') || (eState==2 && c=='&') ){
2524         c = 0;
2525         eState = 1;
2526       }
2527       zFile[iOut++] = c;
2528     }
2529     if( eState==1 ) zFile[iOut++] = '\0';
2530     zFile[iOut++] = '\0';
2531     zFile[iOut++] = '\0';
2532 
2533     /* Check if there were any options specified that should be interpreted
2534     ** here. Options that are interpreted here include "vfs" and those that
2535     ** correspond to flags that may be passed to the sqlite3_open_v2()
2536     ** method. */
2537     zOpt = &zFile[sqlite3Strlen30(zFile)+1];
2538     while( zOpt[0] ){
2539       int nOpt = sqlite3Strlen30(zOpt);
2540       char *zVal = &zOpt[nOpt+1];
2541       int nVal = sqlite3Strlen30(zVal);
2542 
2543       if( nOpt==3 && memcmp("vfs", zOpt, 3)==0 ){
2544         zVfs = zVal;
2545       }else{
2546         struct OpenMode {
2547           const char *z;
2548           int mode;
2549         } *aMode = 0;
2550         char *zModeType = 0;
2551         int mask = 0;
2552         int limit = 0;
2553 
2554         if( nOpt==5 && memcmp("cache", zOpt, 5)==0 ){
2555           static struct OpenMode aCacheMode[] = {
2556             { "shared",  SQLITE_OPEN_SHAREDCACHE },
2557             { "private", SQLITE_OPEN_PRIVATECACHE },
2558             { 0, 0 }
2559           };
2560 
2561           mask = SQLITE_OPEN_SHAREDCACHE|SQLITE_OPEN_PRIVATECACHE;
2562           aMode = aCacheMode;
2563           limit = mask;
2564           zModeType = "cache";
2565         }
2566         if( nOpt==4 && memcmp("mode", zOpt, 4)==0 ){
2567           static struct OpenMode aOpenMode[] = {
2568             { "ro",  SQLITE_OPEN_READONLY },
2569             { "rw",  SQLITE_OPEN_READWRITE },
2570             { "rwc", SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE },
2571             { "memory", SQLITE_OPEN_MEMORY },
2572             { 0, 0 }
2573           };
2574 
2575           mask = SQLITE_OPEN_READONLY | SQLITE_OPEN_READWRITE
2576                    | SQLITE_OPEN_CREATE | SQLITE_OPEN_MEMORY;
2577           aMode = aOpenMode;
2578           limit = mask & flags;
2579           zModeType = "access";
2580         }
2581 
2582         if( aMode ){
2583           int i;
2584           int mode = 0;
2585           for(i=0; aMode[i].z; i++){
2586             const char *z = aMode[i].z;
2587             if( nVal==sqlite3Strlen30(z) && 0==memcmp(zVal, z, nVal) ){
2588               mode = aMode[i].mode;
2589               break;
2590             }
2591           }
2592           if( mode==0 ){
2593             *pzErrMsg = sqlite3_mprintf("no such %s mode: %s", zModeType, zVal);
2594             rc = SQLITE_ERROR;
2595             goto parse_uri_out;
2596           }
2597           if( (mode & ~SQLITE_OPEN_MEMORY)>limit ){
2598             *pzErrMsg = sqlite3_mprintf("%s mode not allowed: %s",
2599                                         zModeType, zVal);
2600             rc = SQLITE_PERM;
2601             goto parse_uri_out;
2602           }
2603           flags = (flags & ~mask) | mode;
2604         }
2605       }
2606 
2607       zOpt = &zVal[nVal+1];
2608     }
2609 
2610   }else{
2611     zFile = sqlite3_malloc64(nUri+2);
2612     if( !zFile ) return SQLITE_NOMEM;
2613     memcpy(zFile, zUri, nUri);
2614     zFile[nUri] = '\0';
2615     zFile[nUri+1] = '\0';
2616     flags &= ~SQLITE_OPEN_URI;
2617   }
2618 
2619   *ppVfs = sqlite3_vfs_find(zVfs);
2620   if( *ppVfs==0 ){
2621     *pzErrMsg = sqlite3_mprintf("no such vfs: %s", zVfs);
2622     rc = SQLITE_ERROR;
2623   }
2624  parse_uri_out:
2625   if( rc!=SQLITE_OK ){
2626     sqlite3_free(zFile);
2627     zFile = 0;
2628   }
2629   *pFlags = flags;
2630   *pzFile = zFile;
2631   return rc;
2632 }
2633 
2634 
2635 /*
2636 ** This routine does the work of opening a database on behalf of
2637 ** sqlite3_open() and sqlite3_open16(). The database filename "zFilename"
2638 ** is UTF-8 encoded.
2639 */
2640 static int openDatabase(
2641   const char *zFilename, /* Database filename UTF-8 encoded */
2642   sqlite3 **ppDb,        /* OUT: Returned database handle */
2643   unsigned int flags,    /* Operational flags */
2644   const char *zVfs       /* Name of the VFS to use */
2645 ){
2646   sqlite3 *db;                    /* Store allocated handle here */
2647   int rc;                         /* Return code */
2648   int isThreadsafe;               /* True for threadsafe connections */
2649   char *zOpen = 0;                /* Filename argument to pass to BtreeOpen() */
2650   char *zErrMsg = 0;              /* Error message from sqlite3ParseUri() */
2651 
2652 #ifdef SQLITE_ENABLE_API_ARMOR
2653   if( ppDb==0 ) return SQLITE_MISUSE_BKPT;
2654 #endif
2655   *ppDb = 0;
2656 #ifndef SQLITE_OMIT_AUTOINIT
2657   rc = sqlite3_initialize();
2658   if( rc ) return rc;
2659 #endif
2660 
2661   /* Only allow sensible combinations of bits in the flags argument.
2662   ** Throw an error if any non-sense combination is used.  If we
2663   ** do not block illegal combinations here, it could trigger
2664   ** assert() statements in deeper layers.  Sensible combinations
2665   ** are:
2666   **
2667   **  1:  SQLITE_OPEN_READONLY
2668   **  2:  SQLITE_OPEN_READWRITE
2669   **  6:  SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE
2670   */
2671   assert( SQLITE_OPEN_READONLY  == 0x01 );
2672   assert( SQLITE_OPEN_READWRITE == 0x02 );
2673   assert( SQLITE_OPEN_CREATE    == 0x04 );
2674   testcase( (1<<(flags&7))==0x02 ); /* READONLY */
2675   testcase( (1<<(flags&7))==0x04 ); /* READWRITE */
2676   testcase( (1<<(flags&7))==0x40 ); /* READWRITE | CREATE */
2677   if( ((1<<(flags&7)) & 0x46)==0 ){
2678     return SQLITE_MISUSE_BKPT;  /* IMP: R-65497-44594 */
2679   }
2680 
2681   if( sqlite3GlobalConfig.bCoreMutex==0 ){
2682     isThreadsafe = 0;
2683   }else if( flags & SQLITE_OPEN_NOMUTEX ){
2684     isThreadsafe = 0;
2685   }else if( flags & SQLITE_OPEN_FULLMUTEX ){
2686     isThreadsafe = 1;
2687   }else{
2688     isThreadsafe = sqlite3GlobalConfig.bFullMutex;
2689   }
2690   if( flags & SQLITE_OPEN_PRIVATECACHE ){
2691     flags &= ~SQLITE_OPEN_SHAREDCACHE;
2692   }else if( sqlite3GlobalConfig.sharedCacheEnabled ){
2693     flags |= SQLITE_OPEN_SHAREDCACHE;
2694   }
2695 
2696   /* Remove harmful bits from the flags parameter
2697   **
2698   ** The SQLITE_OPEN_NOMUTEX and SQLITE_OPEN_FULLMUTEX flags were
2699   ** dealt with in the previous code block.  Besides these, the only
2700   ** valid input flags for sqlite3_open_v2() are SQLITE_OPEN_READONLY,
2701   ** SQLITE_OPEN_READWRITE, SQLITE_OPEN_CREATE, SQLITE_OPEN_SHAREDCACHE,
2702   ** SQLITE_OPEN_PRIVATECACHE, and some reserved bits.  Silently mask
2703   ** off all other flags.
2704   */
2705   flags &=  ~( SQLITE_OPEN_DELETEONCLOSE |
2706                SQLITE_OPEN_EXCLUSIVE |
2707                SQLITE_OPEN_MAIN_DB |
2708                SQLITE_OPEN_TEMP_DB |
2709                SQLITE_OPEN_TRANSIENT_DB |
2710                SQLITE_OPEN_MAIN_JOURNAL |
2711                SQLITE_OPEN_TEMP_JOURNAL |
2712                SQLITE_OPEN_SUBJOURNAL |
2713                SQLITE_OPEN_MASTER_JOURNAL |
2714                SQLITE_OPEN_NOMUTEX |
2715                SQLITE_OPEN_FULLMUTEX |
2716                SQLITE_OPEN_WAL
2717              );
2718 
2719   /* Allocate the sqlite data structure */
2720   db = sqlite3MallocZero( sizeof(sqlite3) );
2721   if( db==0 ) goto opendb_out;
2722   if( isThreadsafe ){
2723     db->mutex = sqlite3MutexAlloc(SQLITE_MUTEX_RECURSIVE);
2724     if( db->mutex==0 ){
2725       sqlite3_free(db);
2726       db = 0;
2727       goto opendb_out;
2728     }
2729   }
2730   sqlite3_mutex_enter(db->mutex);
2731   db->errMask = 0xff;
2732   db->nDb = 2;
2733   db->magic = SQLITE_MAGIC_BUSY;
2734   db->aDb = db->aDbStatic;
2735 
2736   assert( sizeof(db->aLimit)==sizeof(aHardLimit) );
2737   memcpy(db->aLimit, aHardLimit, sizeof(db->aLimit));
2738   db->aLimit[SQLITE_LIMIT_WORKER_THREADS] = SQLITE_DEFAULT_WORKER_THREADS;
2739   db->autoCommit = 1;
2740   db->nextAutovac = -1;
2741   db->szMmap = sqlite3GlobalConfig.szMmap;
2742   db->nextPagesize = 0;
2743   db->nMaxSorterMmap = 0x7FFFFFFF;
2744   db->flags |= SQLITE_ShortColNames | SQLITE_EnableTrigger | SQLITE_CacheSpill
2745 #if !defined(SQLITE_DEFAULT_AUTOMATIC_INDEX) || SQLITE_DEFAULT_AUTOMATIC_INDEX
2746                  | SQLITE_AutoIndex
2747 #endif
2748 #if SQLITE_DEFAULT_CKPTFULLFSYNC
2749                  | SQLITE_CkptFullFSync
2750 #endif
2751 #if SQLITE_DEFAULT_FILE_FORMAT<4
2752                  | SQLITE_LegacyFileFmt
2753 #endif
2754 #ifdef SQLITE_ENABLE_LOAD_EXTENSION
2755                  | SQLITE_LoadExtension
2756 #endif
2757 #if SQLITE_DEFAULT_RECURSIVE_TRIGGERS
2758                  | SQLITE_RecTriggers
2759 #endif
2760 #if defined(SQLITE_DEFAULT_FOREIGN_KEYS) && SQLITE_DEFAULT_FOREIGN_KEYS
2761                  | SQLITE_ForeignKeys
2762 #endif
2763 #if defined(SQLITE_REVERSE_UNORDERED_SELECTS)
2764                  | SQLITE_ReverseOrder
2765 #endif
2766 #if defined(SQLITE_ENABLE_OVERSIZE_CELL_CHECK)
2767                  | SQLITE_CellSizeCk
2768 #endif
2769       ;
2770   sqlite3HashInit(&db->aCollSeq);
2771 #ifndef SQLITE_OMIT_VIRTUALTABLE
2772   sqlite3HashInit(&db->aModule);
2773 #endif
2774 
2775   /* Add the default collation sequence BINARY. BINARY works for both UTF-8
2776   ** and UTF-16, so add a version for each to avoid any unnecessary
2777   ** conversions. The only error that can occur here is a malloc() failure.
2778   **
2779   ** EVIDENCE-OF: R-52786-44878 SQLite defines three built-in collating
2780   ** functions:
2781   */
2782   createCollation(db, "BINARY", SQLITE_UTF8, 0, binCollFunc, 0);
2783   createCollation(db, "BINARY", SQLITE_UTF16BE, 0, binCollFunc, 0);
2784   createCollation(db, "BINARY", SQLITE_UTF16LE, 0, binCollFunc, 0);
2785   createCollation(db, "NOCASE", SQLITE_UTF8, 0, nocaseCollatingFunc, 0);
2786   createCollation(db, "RTRIM", SQLITE_UTF8, (void*)1, binCollFunc, 0);
2787   if( db->mallocFailed ){
2788     goto opendb_out;
2789   }
2790   /* EVIDENCE-OF: R-08308-17224 The default collating function for all
2791   ** strings is BINARY.
2792   */
2793   db->pDfltColl = sqlite3FindCollSeq(db, SQLITE_UTF8, "BINARY", 0);
2794   assert( db->pDfltColl!=0 );
2795 
2796   /* Parse the filename/URI argument. */
2797   db->openFlags = flags;
2798   rc = sqlite3ParseUri(zVfs, zFilename, &flags, &db->pVfs, &zOpen, &zErrMsg);
2799   if( rc!=SQLITE_OK ){
2800     if( rc==SQLITE_NOMEM ) db->mallocFailed = 1;
2801     sqlite3ErrorWithMsg(db, rc, zErrMsg ? "%s" : 0, zErrMsg);
2802     sqlite3_free(zErrMsg);
2803     goto opendb_out;
2804   }
2805 
2806   /* Open the backend database driver */
2807   rc = sqlite3BtreeOpen(db->pVfs, zOpen, db, &db->aDb[0].pBt, 0,
2808                         flags | SQLITE_OPEN_MAIN_DB);
2809   if( rc!=SQLITE_OK ){
2810     if( rc==SQLITE_IOERR_NOMEM ){
2811       rc = SQLITE_NOMEM;
2812     }
2813     sqlite3Error(db, rc);
2814     goto opendb_out;
2815   }
2816   sqlite3BtreeEnter(db->aDb[0].pBt);
2817   db->aDb[0].pSchema = sqlite3SchemaGet(db, db->aDb[0].pBt);
2818   if( !db->mallocFailed ) ENC(db) = SCHEMA_ENC(db);
2819   sqlite3BtreeLeave(db->aDb[0].pBt);
2820   db->aDb[1].pSchema = sqlite3SchemaGet(db, 0);
2821 
2822   /* The default safety_level for the main database is 'full'; for the temp
2823   ** database it is 'NONE'. This matches the pager layer defaults.
2824   */
2825   db->aDb[0].zName = "main";
2826   db->aDb[0].safety_level = 3;
2827   db->aDb[1].zName = "temp";
2828   db->aDb[1].safety_level = 1;
2829 
2830   db->magic = SQLITE_MAGIC_OPEN;
2831   if( db->mallocFailed ){
2832     goto opendb_out;
2833   }
2834 
2835   /* Register all built-in functions, but do not attempt to read the
2836   ** database schema yet. This is delayed until the first time the database
2837   ** is accessed.
2838   */
2839   sqlite3Error(db, SQLITE_OK);
2840   sqlite3RegisterBuiltinFunctions(db);
2841 
2842   /* Load automatic extensions - extensions that have been registered
2843   ** using the sqlite3_automatic_extension() API.
2844   */
2845   rc = sqlite3_errcode(db);
2846   if( rc==SQLITE_OK ){
2847     sqlite3AutoLoadExtensions(db);
2848     rc = sqlite3_errcode(db);
2849     if( rc!=SQLITE_OK ){
2850       goto opendb_out;
2851     }
2852   }
2853 
2854 #ifdef SQLITE_ENABLE_FTS1
2855   if( !db->mallocFailed ){
2856     extern int sqlite3Fts1Init(sqlite3*);
2857     rc = sqlite3Fts1Init(db);
2858   }
2859 #endif
2860 
2861 #ifdef SQLITE_ENABLE_FTS2
2862   if( !db->mallocFailed && rc==SQLITE_OK ){
2863     extern int sqlite3Fts2Init(sqlite3*);
2864     rc = sqlite3Fts2Init(db);
2865   }
2866 #endif
2867 
2868 #ifdef SQLITE_ENABLE_FTS3
2869   if( !db->mallocFailed && rc==SQLITE_OK ){
2870     rc = sqlite3Fts3Init(db);
2871   }
2872 #endif
2873 
2874 #ifdef SQLITE_ENABLE_ICU
2875   if( !db->mallocFailed && rc==SQLITE_OK ){
2876     rc = sqlite3IcuInit(db);
2877   }
2878 #endif
2879 
2880 #ifdef SQLITE_ENABLE_RTREE
2881   if( !db->mallocFailed && rc==SQLITE_OK){
2882     rc = sqlite3RtreeInit(db);
2883   }
2884 #endif
2885 
2886 #ifdef SQLITE_ENABLE_DBSTAT_VTAB
2887   if( !db->mallocFailed && rc==SQLITE_OK){
2888     rc = sqlite3DbstatRegister(db);
2889   }
2890 #endif
2891 
2892   /* -DSQLITE_DEFAULT_LOCKING_MODE=1 makes EXCLUSIVE the default locking
2893   ** mode.  -DSQLITE_DEFAULT_LOCKING_MODE=0 make NORMAL the default locking
2894   ** mode.  Doing nothing at all also makes NORMAL the default.
2895   */
2896 #ifdef SQLITE_DEFAULT_LOCKING_MODE
2897   db->dfltLockMode = SQLITE_DEFAULT_LOCKING_MODE;
2898   sqlite3PagerLockingMode(sqlite3BtreePager(db->aDb[0].pBt),
2899                           SQLITE_DEFAULT_LOCKING_MODE);
2900 #endif
2901 
2902   if( rc ) sqlite3Error(db, rc);
2903 
2904   /* Enable the lookaside-malloc subsystem */
2905   setupLookaside(db, 0, sqlite3GlobalConfig.szLookaside,
2906                         sqlite3GlobalConfig.nLookaside);
2907 
2908   sqlite3_wal_autocheckpoint(db, SQLITE_DEFAULT_WAL_AUTOCHECKPOINT);
2909 
2910 opendb_out:
2911   sqlite3_free(zOpen);
2912   if( db ){
2913     assert( db->mutex!=0 || isThreadsafe==0
2914            || sqlite3GlobalConfig.bFullMutex==0 );
2915     sqlite3_mutex_leave(db->mutex);
2916   }
2917   rc = sqlite3_errcode(db);
2918   assert( db!=0 || rc==SQLITE_NOMEM );
2919   if( rc==SQLITE_NOMEM ){
2920     sqlite3_close(db);
2921     db = 0;
2922   }else if( rc!=SQLITE_OK ){
2923     db->magic = SQLITE_MAGIC_SICK;
2924   }
2925   *ppDb = db;
2926 #ifdef SQLITE_ENABLE_SQLLOG
2927   if( sqlite3GlobalConfig.xSqllog ){
2928     /* Opening a db handle. Fourth parameter is passed 0. */
2929     void *pArg = sqlite3GlobalConfig.pSqllogArg;
2930     sqlite3GlobalConfig.xSqllog(pArg, db, zFilename, 0);
2931   }
2932 #endif
2933   return rc & 0xff;
2934 }
2935 
2936 /*
2937 ** Open a new database handle.
2938 */
2939 int sqlite3_open(
2940   const char *zFilename,
2941   sqlite3 **ppDb
2942 ){
2943   return openDatabase(zFilename, ppDb,
2944                       SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
2945 }
2946 int sqlite3_open_v2(
2947   const char *filename,   /* Database filename (UTF-8) */
2948   sqlite3 **ppDb,         /* OUT: SQLite db handle */
2949   int flags,              /* Flags */
2950   const char *zVfs        /* Name of VFS module to use */
2951 ){
2952   return openDatabase(filename, ppDb, (unsigned int)flags, zVfs);
2953 }
2954 
2955 #ifndef SQLITE_OMIT_UTF16
2956 /*
2957 ** Open a new database handle.
2958 */
2959 int sqlite3_open16(
2960   const void *zFilename,
2961   sqlite3 **ppDb
2962 ){
2963   char const *zFilename8;   /* zFilename encoded in UTF-8 instead of UTF-16 */
2964   sqlite3_value *pVal;
2965   int rc;
2966 
2967 #ifdef SQLITE_ENABLE_API_ARMOR
2968   if( ppDb==0 ) return SQLITE_MISUSE_BKPT;
2969 #endif
2970   *ppDb = 0;
2971 #ifndef SQLITE_OMIT_AUTOINIT
2972   rc = sqlite3_initialize();
2973   if( rc ) return rc;
2974 #endif
2975   if( zFilename==0 ) zFilename = "\000\000";
2976   pVal = sqlite3ValueNew(0);
2977   sqlite3ValueSetStr(pVal, -1, zFilename, SQLITE_UTF16NATIVE, SQLITE_STATIC);
2978   zFilename8 = sqlite3ValueText(pVal, SQLITE_UTF8);
2979   if( zFilename8 ){
2980     rc = openDatabase(zFilename8, ppDb,
2981                       SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
2982     assert( *ppDb || rc==SQLITE_NOMEM );
2983     if( rc==SQLITE_OK && !DbHasProperty(*ppDb, 0, DB_SchemaLoaded) ){
2984       SCHEMA_ENC(*ppDb) = ENC(*ppDb) = SQLITE_UTF16NATIVE;
2985     }
2986   }else{
2987     rc = SQLITE_NOMEM;
2988   }
2989   sqlite3ValueFree(pVal);
2990 
2991   return rc & 0xff;
2992 }
2993 #endif /* SQLITE_OMIT_UTF16 */
2994 
2995 /*
2996 ** Register a new collation sequence with the database handle db.
2997 */
2998 int sqlite3_create_collation(
2999   sqlite3* db,
3000   const char *zName,
3001   int enc,
3002   void* pCtx,
3003   int(*xCompare)(void*,int,const void*,int,const void*)
3004 ){
3005   return sqlite3_create_collation_v2(db, zName, enc, pCtx, xCompare, 0);
3006 }
3007 
3008 /*
3009 ** Register a new collation sequence with the database handle db.
3010 */
3011 int sqlite3_create_collation_v2(
3012   sqlite3* db,
3013   const char *zName,
3014   int enc,
3015   void* pCtx,
3016   int(*xCompare)(void*,int,const void*,int,const void*),
3017   void(*xDel)(void*)
3018 ){
3019   int rc;
3020 
3021 #ifdef SQLITE_ENABLE_API_ARMOR
3022   if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
3023 #endif
3024   sqlite3_mutex_enter(db->mutex);
3025   assert( !db->mallocFailed );
3026   rc = createCollation(db, zName, (u8)enc, pCtx, xCompare, xDel);
3027   rc = sqlite3ApiExit(db, rc);
3028   sqlite3_mutex_leave(db->mutex);
3029   return rc;
3030 }
3031 
3032 #ifndef SQLITE_OMIT_UTF16
3033 /*
3034 ** Register a new collation sequence with the database handle db.
3035 */
3036 int sqlite3_create_collation16(
3037   sqlite3* db,
3038   const void *zName,
3039   int enc,
3040   void* pCtx,
3041   int(*xCompare)(void*,int,const void*,int,const void*)
3042 ){
3043   int rc = SQLITE_OK;
3044   char *zName8;
3045 
3046 #ifdef SQLITE_ENABLE_API_ARMOR
3047   if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
3048 #endif
3049   sqlite3_mutex_enter(db->mutex);
3050   assert( !db->mallocFailed );
3051   zName8 = sqlite3Utf16to8(db, zName, -1, SQLITE_UTF16NATIVE);
3052   if( zName8 ){
3053     rc = createCollation(db, zName8, (u8)enc, pCtx, xCompare, 0);
3054     sqlite3DbFree(db, zName8);
3055   }
3056   rc = sqlite3ApiExit(db, rc);
3057   sqlite3_mutex_leave(db->mutex);
3058   return rc;
3059 }
3060 #endif /* SQLITE_OMIT_UTF16 */
3061 
3062 /*
3063 ** Register a collation sequence factory callback with the database handle
3064 ** db. Replace any previously installed collation sequence factory.
3065 */
3066 int sqlite3_collation_needed(
3067   sqlite3 *db,
3068   void *pCollNeededArg,
3069   void(*xCollNeeded)(void*,sqlite3*,int eTextRep,const char*)
3070 ){
3071 #ifdef SQLITE_ENABLE_API_ARMOR
3072   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3073 #endif
3074   sqlite3_mutex_enter(db->mutex);
3075   db->xCollNeeded = xCollNeeded;
3076   db->xCollNeeded16 = 0;
3077   db->pCollNeededArg = pCollNeededArg;
3078   sqlite3_mutex_leave(db->mutex);
3079   return SQLITE_OK;
3080 }
3081 
3082 #ifndef SQLITE_OMIT_UTF16
3083 /*
3084 ** Register a collation sequence factory callback with the database handle
3085 ** db. Replace any previously installed collation sequence factory.
3086 */
3087 int sqlite3_collation_needed16(
3088   sqlite3 *db,
3089   void *pCollNeededArg,
3090   void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*)
3091 ){
3092 #ifdef SQLITE_ENABLE_API_ARMOR
3093   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3094 #endif
3095   sqlite3_mutex_enter(db->mutex);
3096   db->xCollNeeded = 0;
3097   db->xCollNeeded16 = xCollNeeded16;
3098   db->pCollNeededArg = pCollNeededArg;
3099   sqlite3_mutex_leave(db->mutex);
3100   return SQLITE_OK;
3101 }
3102 #endif /* SQLITE_OMIT_UTF16 */
3103 
3104 #ifndef SQLITE_OMIT_DEPRECATED
3105 /*
3106 ** This function is now an anachronism. It used to be used to recover from a
3107 ** malloc() failure, but SQLite now does this automatically.
3108 */
3109 int sqlite3_global_recover(void){
3110   return SQLITE_OK;
3111 }
3112 #endif
3113 
3114 /*
3115 ** Test to see whether or not the database connection is in autocommit
3116 ** mode.  Return TRUE if it is and FALSE if not.  Autocommit mode is on
3117 ** by default.  Autocommit is disabled by a BEGIN statement and reenabled
3118 ** by the next COMMIT or ROLLBACK.
3119 */
3120 int sqlite3_get_autocommit(sqlite3 *db){
3121 #ifdef SQLITE_ENABLE_API_ARMOR
3122   if( !sqlite3SafetyCheckOk(db) ){
3123     (void)SQLITE_MISUSE_BKPT;
3124     return 0;
3125   }
3126 #endif
3127   return db->autoCommit;
3128 }
3129 
3130 /*
3131 ** The following routines are substitutes for constants SQLITE_CORRUPT,
3132 ** SQLITE_MISUSE, SQLITE_CANTOPEN, SQLITE_IOERR and possibly other error
3133 ** constants.  They serve two purposes:
3134 **
3135 **   1.  Serve as a convenient place to set a breakpoint in a debugger
3136 **       to detect when version error conditions occurs.
3137 **
3138 **   2.  Invoke sqlite3_log() to provide the source code location where
3139 **       a low-level error is first detected.
3140 */
3141 int sqlite3CorruptError(int lineno){
3142   testcase( sqlite3GlobalConfig.xLog!=0 );
3143   sqlite3_log(SQLITE_CORRUPT,
3144               "database corruption at line %d of [%.10s]",
3145               lineno, 20+sqlite3_sourceid());
3146   return SQLITE_CORRUPT;
3147 }
3148 int sqlite3MisuseError(int lineno){
3149   testcase( sqlite3GlobalConfig.xLog!=0 );
3150   sqlite3_log(SQLITE_MISUSE,
3151               "misuse at line %d of [%.10s]",
3152               lineno, 20+sqlite3_sourceid());
3153   return SQLITE_MISUSE;
3154 }
3155 int sqlite3CantopenError(int lineno){
3156   testcase( sqlite3GlobalConfig.xLog!=0 );
3157   sqlite3_log(SQLITE_CANTOPEN,
3158               "cannot open file at line %d of [%.10s]",
3159               lineno, 20+sqlite3_sourceid());
3160   return SQLITE_CANTOPEN;
3161 }
3162 
3163 
3164 #ifndef SQLITE_OMIT_DEPRECATED
3165 /*
3166 ** This is a convenience routine that makes sure that all thread-specific
3167 ** data for this thread has been deallocated.
3168 **
3169 ** SQLite no longer uses thread-specific data so this routine is now a
3170 ** no-op.  It is retained for historical compatibility.
3171 */
3172 void sqlite3_thread_cleanup(void){
3173 }
3174 #endif
3175 
3176 /*
3177 ** Return meta information about a specific column of a database table.
3178 ** See comment in sqlite3.h (sqlite.h.in) for details.
3179 */
3180 int sqlite3_table_column_metadata(
3181   sqlite3 *db,                /* Connection handle */
3182   const char *zDbName,        /* Database name or NULL */
3183   const char *zTableName,     /* Table name */
3184   const char *zColumnName,    /* Column name */
3185   char const **pzDataType,    /* OUTPUT: Declared data type */
3186   char const **pzCollSeq,     /* OUTPUT: Collation sequence name */
3187   int *pNotNull,              /* OUTPUT: True if NOT NULL constraint exists */
3188   int *pPrimaryKey,           /* OUTPUT: True if column part of PK */
3189   int *pAutoinc               /* OUTPUT: True if column is auto-increment */
3190 ){
3191   int rc;
3192   char *zErrMsg = 0;
3193   Table *pTab = 0;
3194   Column *pCol = 0;
3195   int iCol = 0;
3196   char const *zDataType = 0;
3197   char const *zCollSeq = 0;
3198   int notnull = 0;
3199   int primarykey = 0;
3200   int autoinc = 0;
3201 
3202 
3203 #ifdef SQLITE_ENABLE_API_ARMOR
3204   if( !sqlite3SafetyCheckOk(db) || zTableName==0 ){
3205     return SQLITE_MISUSE_BKPT;
3206   }
3207 #endif
3208 
3209   /* Ensure the database schema has been loaded */
3210   sqlite3_mutex_enter(db->mutex);
3211   sqlite3BtreeEnterAll(db);
3212   rc = sqlite3Init(db, &zErrMsg);
3213   if( SQLITE_OK!=rc ){
3214     goto error_out;
3215   }
3216 
3217   /* Locate the table in question */
3218   pTab = sqlite3FindTable(db, zTableName, zDbName);
3219   if( !pTab || pTab->pSelect ){
3220     pTab = 0;
3221     goto error_out;
3222   }
3223 
3224   /* Find the column for which info is requested */
3225   if( zColumnName==0 ){
3226     /* Query for existance of table only */
3227   }else{
3228     for(iCol=0; iCol<pTab->nCol; iCol++){
3229       pCol = &pTab->aCol[iCol];
3230       if( 0==sqlite3StrICmp(pCol->zName, zColumnName) ){
3231         break;
3232       }
3233     }
3234     if( iCol==pTab->nCol ){
3235       if( HasRowid(pTab) && sqlite3IsRowid(zColumnName) ){
3236         iCol = pTab->iPKey;
3237         pCol = iCol>=0 ? &pTab->aCol[iCol] : 0;
3238       }else{
3239         pTab = 0;
3240         goto error_out;
3241       }
3242     }
3243   }
3244 
3245   /* The following block stores the meta information that will be returned
3246   ** to the caller in local variables zDataType, zCollSeq, notnull, primarykey
3247   ** and autoinc. At this point there are two possibilities:
3248   **
3249   **     1. The specified column name was rowid", "oid" or "_rowid_"
3250   **        and there is no explicitly declared IPK column.
3251   **
3252   **     2. The table is not a view and the column name identified an
3253   **        explicitly declared column. Copy meta information from *pCol.
3254   */
3255   if( pCol ){
3256     zDataType = pCol->zType;
3257     zCollSeq = pCol->zColl;
3258     notnull = pCol->notNull!=0;
3259     primarykey  = (pCol->colFlags & COLFLAG_PRIMKEY)!=0;
3260     autoinc = pTab->iPKey==iCol && (pTab->tabFlags & TF_Autoincrement)!=0;
3261   }else{
3262     zDataType = "INTEGER";
3263     primarykey = 1;
3264   }
3265   if( !zCollSeq ){
3266     zCollSeq = "BINARY";
3267   }
3268 
3269 error_out:
3270   sqlite3BtreeLeaveAll(db);
3271 
3272   /* Whether the function call succeeded or failed, set the output parameters
3273   ** to whatever their local counterparts contain. If an error did occur,
3274   ** this has the effect of zeroing all output parameters.
3275   */
3276   if( pzDataType ) *pzDataType = zDataType;
3277   if( pzCollSeq ) *pzCollSeq = zCollSeq;
3278   if( pNotNull ) *pNotNull = notnull;
3279   if( pPrimaryKey ) *pPrimaryKey = primarykey;
3280   if( pAutoinc ) *pAutoinc = autoinc;
3281 
3282   if( SQLITE_OK==rc && !pTab ){
3283     sqlite3DbFree(db, zErrMsg);
3284     zErrMsg = sqlite3MPrintf(db, "no such table column: %s.%s", zTableName,
3285         zColumnName);
3286     rc = SQLITE_ERROR;
3287   }
3288   sqlite3ErrorWithMsg(db, rc, (zErrMsg?"%s":0), zErrMsg);
3289   sqlite3DbFree(db, zErrMsg);
3290   rc = sqlite3ApiExit(db, rc);
3291   sqlite3_mutex_leave(db->mutex);
3292   return rc;
3293 }
3294 
3295 /*
3296 ** Sleep for a little while.  Return the amount of time slept.
3297 */
3298 int sqlite3_sleep(int ms){
3299   sqlite3_vfs *pVfs;
3300   int rc;
3301   pVfs = sqlite3_vfs_find(0);
3302   if( pVfs==0 ) return 0;
3303 
3304   /* This function works in milliseconds, but the underlying OsSleep()
3305   ** API uses microseconds. Hence the 1000's.
3306   */
3307   rc = (sqlite3OsSleep(pVfs, 1000*ms)/1000);
3308   return rc;
3309 }
3310 
3311 /*
3312 ** Enable or disable the extended result codes.
3313 */
3314 int sqlite3_extended_result_codes(sqlite3 *db, int onoff){
3315 #ifdef SQLITE_ENABLE_API_ARMOR
3316   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3317 #endif
3318   sqlite3_mutex_enter(db->mutex);
3319   db->errMask = onoff ? 0xffffffff : 0xff;
3320   sqlite3_mutex_leave(db->mutex);
3321   return SQLITE_OK;
3322 }
3323 
3324 /*
3325 ** Invoke the xFileControl method on a particular database.
3326 */
3327 int sqlite3_file_control(sqlite3 *db, const char *zDbName, int op, void *pArg){
3328   int rc = SQLITE_ERROR;
3329   Btree *pBtree;
3330 
3331 #ifdef SQLITE_ENABLE_API_ARMOR
3332   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3333 #endif
3334   sqlite3_mutex_enter(db->mutex);
3335   pBtree = sqlite3DbNameToBtree(db, zDbName);
3336   if( pBtree ){
3337     Pager *pPager;
3338     sqlite3_file *fd;
3339     sqlite3BtreeEnter(pBtree);
3340     pPager = sqlite3BtreePager(pBtree);
3341     assert( pPager!=0 );
3342     fd = sqlite3PagerFile(pPager);
3343     assert( fd!=0 );
3344     if( op==SQLITE_FCNTL_FILE_POINTER ){
3345       *(sqlite3_file**)pArg = fd;
3346       rc = SQLITE_OK;
3347     }else if( fd->pMethods ){
3348       rc = sqlite3OsFileControl(fd, op, pArg);
3349     }else{
3350       rc = SQLITE_NOTFOUND;
3351     }
3352     sqlite3BtreeLeave(pBtree);
3353   }
3354   sqlite3_mutex_leave(db->mutex);
3355   return rc;
3356 }
3357 
3358 /*
3359 ** Interface to the testing logic.
3360 */
3361 int sqlite3_test_control(int op, ...){
3362   int rc = 0;
3363 #ifdef SQLITE_OMIT_BUILTIN_TEST
3364   UNUSED_PARAMETER(op);
3365 #else
3366   va_list ap;
3367   va_start(ap, op);
3368   switch( op ){
3369 
3370     /*
3371     ** Save the current state of the PRNG.
3372     */
3373     case SQLITE_TESTCTRL_PRNG_SAVE: {
3374       sqlite3PrngSaveState();
3375       break;
3376     }
3377 
3378     /*
3379     ** Restore the state of the PRNG to the last state saved using
3380     ** PRNG_SAVE.  If PRNG_SAVE has never before been called, then
3381     ** this verb acts like PRNG_RESET.
3382     */
3383     case SQLITE_TESTCTRL_PRNG_RESTORE: {
3384       sqlite3PrngRestoreState();
3385       break;
3386     }
3387 
3388     /*
3389     ** Reset the PRNG back to its uninitialized state.  The next call
3390     ** to sqlite3_randomness() will reseed the PRNG using a single call
3391     ** to the xRandomness method of the default VFS.
3392     */
3393     case SQLITE_TESTCTRL_PRNG_RESET: {
3394       sqlite3_randomness(0,0);
3395       break;
3396     }
3397 
3398     /*
3399     **  sqlite3_test_control(BITVEC_TEST, size, program)
3400     **
3401     ** Run a test against a Bitvec object of size.  The program argument
3402     ** is an array of integers that defines the test.  Return -1 on a
3403     ** memory allocation error, 0 on success, or non-zero for an error.
3404     ** See the sqlite3BitvecBuiltinTest() for additional information.
3405     */
3406     case SQLITE_TESTCTRL_BITVEC_TEST: {
3407       int sz = va_arg(ap, int);
3408       int *aProg = va_arg(ap, int*);
3409       rc = sqlite3BitvecBuiltinTest(sz, aProg);
3410       break;
3411     }
3412 
3413     /*
3414     **  sqlite3_test_control(FAULT_INSTALL, xCallback)
3415     **
3416     ** Arrange to invoke xCallback() whenever sqlite3FaultSim() is called,
3417     ** if xCallback is not NULL.
3418     **
3419     ** As a test of the fault simulator mechanism itself, sqlite3FaultSim(0)
3420     ** is called immediately after installing the new callback and the return
3421     ** value from sqlite3FaultSim(0) becomes the return from
3422     ** sqlite3_test_control().
3423     */
3424     case SQLITE_TESTCTRL_FAULT_INSTALL: {
3425       /* MSVC is picky about pulling func ptrs from va lists.
3426       ** http://support.microsoft.com/kb/47961
3427       ** sqlite3GlobalConfig.xTestCallback = va_arg(ap, int(*)(int));
3428       */
3429       typedef int(*TESTCALLBACKFUNC_t)(int);
3430       sqlite3GlobalConfig.xTestCallback = va_arg(ap, TESTCALLBACKFUNC_t);
3431       rc = sqlite3FaultSim(0);
3432       break;
3433     }
3434 
3435     /*
3436     **  sqlite3_test_control(BENIGN_MALLOC_HOOKS, xBegin, xEnd)
3437     **
3438     ** Register hooks to call to indicate which malloc() failures
3439     ** are benign.
3440     */
3441     case SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS: {
3442       typedef void (*void_function)(void);
3443       void_function xBenignBegin;
3444       void_function xBenignEnd;
3445       xBenignBegin = va_arg(ap, void_function);
3446       xBenignEnd = va_arg(ap, void_function);
3447       sqlite3BenignMallocHooks(xBenignBegin, xBenignEnd);
3448       break;
3449     }
3450 
3451     /*
3452     **  sqlite3_test_control(SQLITE_TESTCTRL_PENDING_BYTE, unsigned int X)
3453     **
3454     ** Set the PENDING byte to the value in the argument, if X>0.
3455     ** Make no changes if X==0.  Return the value of the pending byte
3456     ** as it existing before this routine was called.
3457     **
3458     ** IMPORTANT:  Changing the PENDING byte from 0x40000000 results in
3459     ** an incompatible database file format.  Changing the PENDING byte
3460     ** while any database connection is open results in undefined and
3461     ** deleterious behavior.
3462     */
3463     case SQLITE_TESTCTRL_PENDING_BYTE: {
3464       rc = PENDING_BYTE;
3465 #ifndef SQLITE_OMIT_WSD
3466       {
3467         unsigned int newVal = va_arg(ap, unsigned int);
3468         if( newVal ) sqlite3PendingByte = newVal;
3469       }
3470 #endif
3471       break;
3472     }
3473 
3474     /*
3475     **  sqlite3_test_control(SQLITE_TESTCTRL_ASSERT, int X)
3476     **
3477     ** This action provides a run-time test to see whether or not
3478     ** assert() was enabled at compile-time.  If X is true and assert()
3479     ** is enabled, then the return value is true.  If X is true and
3480     ** assert() is disabled, then the return value is zero.  If X is
3481     ** false and assert() is enabled, then the assertion fires and the
3482     ** process aborts.  If X is false and assert() is disabled, then the
3483     ** return value is zero.
3484     */
3485     case SQLITE_TESTCTRL_ASSERT: {
3486       volatile int x = 0;
3487       assert( (x = va_arg(ap,int))!=0 );
3488       rc = x;
3489       break;
3490     }
3491 
3492 
3493     /*
3494     **  sqlite3_test_control(SQLITE_TESTCTRL_ALWAYS, int X)
3495     **
3496     ** This action provides a run-time test to see how the ALWAYS and
3497     ** NEVER macros were defined at compile-time.
3498     **
3499     ** The return value is ALWAYS(X).
3500     **
3501     ** The recommended test is X==2.  If the return value is 2, that means
3502     ** ALWAYS() and NEVER() are both no-op pass-through macros, which is the
3503     ** default setting.  If the return value is 1, then ALWAYS() is either
3504     ** hard-coded to true or else it asserts if its argument is false.
3505     ** The first behavior (hard-coded to true) is the case if
3506     ** SQLITE_TESTCTRL_ASSERT shows that assert() is disabled and the second
3507     ** behavior (assert if the argument to ALWAYS() is false) is the case if
3508     ** SQLITE_TESTCTRL_ASSERT shows that assert() is enabled.
3509     **
3510     ** The run-time test procedure might look something like this:
3511     **
3512     **    if( sqlite3_test_control(SQLITE_TESTCTRL_ALWAYS, 2)==2 ){
3513     **      // ALWAYS() and NEVER() are no-op pass-through macros
3514     **    }else if( sqlite3_test_control(SQLITE_TESTCTRL_ASSERT, 1) ){
3515     **      // ALWAYS(x) asserts that x is true. NEVER(x) asserts x is false.
3516     **    }else{
3517     **      // ALWAYS(x) is a constant 1.  NEVER(x) is a constant 0.
3518     **    }
3519     */
3520     case SQLITE_TESTCTRL_ALWAYS: {
3521       int x = va_arg(ap,int);
3522       rc = ALWAYS(x);
3523       break;
3524     }
3525 
3526     /*
3527     **   sqlite3_test_control(SQLITE_TESTCTRL_BYTEORDER);
3528     **
3529     ** The integer returned reveals the byte-order of the computer on which
3530     ** SQLite is running:
3531     **
3532     **       1     big-endian,    determined at run-time
3533     **      10     little-endian, determined at run-time
3534     **  432101     big-endian,    determined at compile-time
3535     **  123410     little-endian, determined at compile-time
3536     */
3537     case SQLITE_TESTCTRL_BYTEORDER: {
3538       rc = SQLITE_BYTEORDER*100 + SQLITE_LITTLEENDIAN*10 + SQLITE_BIGENDIAN;
3539       break;
3540     }
3541 
3542     /*   sqlite3_test_control(SQLITE_TESTCTRL_RESERVE, sqlite3 *db, int N)
3543     **
3544     ** Set the nReserve size to N for the main database on the database
3545     ** connection db.
3546     */
3547     case SQLITE_TESTCTRL_RESERVE: {
3548       sqlite3 *db = va_arg(ap, sqlite3*);
3549       int x = va_arg(ap,int);
3550       sqlite3_mutex_enter(db->mutex);
3551       sqlite3BtreeSetPageSize(db->aDb[0].pBt, 0, x, 0);
3552       sqlite3_mutex_leave(db->mutex);
3553       break;
3554     }
3555 
3556     /*  sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS, sqlite3 *db, int N)
3557     **
3558     ** Enable or disable various optimizations for testing purposes.  The
3559     ** argument N is a bitmask of optimizations to be disabled.  For normal
3560     ** operation N should be 0.  The idea is that a test program (like the
3561     ** SQL Logic Test or SLT test module) can run the same SQL multiple times
3562     ** with various optimizations disabled to verify that the same answer
3563     ** is obtained in every case.
3564     */
3565     case SQLITE_TESTCTRL_OPTIMIZATIONS: {
3566       sqlite3 *db = va_arg(ap, sqlite3*);
3567       db->dbOptFlags = (u16)(va_arg(ap, int) & 0xffff);
3568       break;
3569     }
3570 
3571 #ifdef SQLITE_N_KEYWORD
3572     /* sqlite3_test_control(SQLITE_TESTCTRL_ISKEYWORD, const char *zWord)
3573     **
3574     ** If zWord is a keyword recognized by the parser, then return the
3575     ** number of keywords.  Or if zWord is not a keyword, return 0.
3576     **
3577     ** This test feature is only available in the amalgamation since
3578     ** the SQLITE_N_KEYWORD macro is not defined in this file if SQLite
3579     ** is built using separate source files.
3580     */
3581     case SQLITE_TESTCTRL_ISKEYWORD: {
3582       const char *zWord = va_arg(ap, const char*);
3583       int n = sqlite3Strlen30(zWord);
3584       rc = (sqlite3KeywordCode((u8*)zWord, n)!=TK_ID) ? SQLITE_N_KEYWORD : 0;
3585       break;
3586     }
3587 #endif
3588 
3589     /* sqlite3_test_control(SQLITE_TESTCTRL_SCRATCHMALLOC, sz, &pNew, pFree);
3590     **
3591     ** Pass pFree into sqlite3ScratchFree().
3592     ** If sz>0 then allocate a scratch buffer into pNew.
3593     */
3594     case SQLITE_TESTCTRL_SCRATCHMALLOC: {
3595       void *pFree, **ppNew;
3596       int sz;
3597       sz = va_arg(ap, int);
3598       ppNew = va_arg(ap, void**);
3599       pFree = va_arg(ap, void*);
3600       if( sz ) *ppNew = sqlite3ScratchMalloc(sz);
3601       sqlite3ScratchFree(pFree);
3602       break;
3603     }
3604 
3605     /*   sqlite3_test_control(SQLITE_TESTCTRL_LOCALTIME_FAULT, int onoff);
3606     **
3607     ** If parameter onoff is non-zero, configure the wrappers so that all
3608     ** subsequent calls to localtime() and variants fail. If onoff is zero,
3609     ** undo this setting.
3610     */
3611     case SQLITE_TESTCTRL_LOCALTIME_FAULT: {
3612       sqlite3GlobalConfig.bLocaltimeFault = va_arg(ap, int);
3613       break;
3614     }
3615 
3616     /*   sqlite3_test_control(SQLITE_TESTCTRL_NEVER_CORRUPT, int);
3617     **
3618     ** Set or clear a flag that indicates that the database file is always well-
3619     ** formed and never corrupt.  This flag is clear by default, indicating that
3620     ** database files might have arbitrary corruption.  Setting the flag during
3621     ** testing causes certain assert() statements in the code to be activated
3622     ** that demonstrat invariants on well-formed database files.
3623     */
3624     case SQLITE_TESTCTRL_NEVER_CORRUPT: {
3625       sqlite3GlobalConfig.neverCorrupt = va_arg(ap, int);
3626       break;
3627     }
3628 
3629 
3630     /*   sqlite3_test_control(SQLITE_TESTCTRL_VDBE_COVERAGE, xCallback, ptr);
3631     **
3632     ** Set the VDBE coverage callback function to xCallback with context
3633     ** pointer ptr.
3634     */
3635     case SQLITE_TESTCTRL_VDBE_COVERAGE: {
3636 #ifdef SQLITE_VDBE_COVERAGE
3637       typedef void (*branch_callback)(void*,int,u8,u8);
3638       sqlite3GlobalConfig.xVdbeBranch = va_arg(ap,branch_callback);
3639       sqlite3GlobalConfig.pVdbeBranchArg = va_arg(ap,void*);
3640 #endif
3641       break;
3642     }
3643 
3644     /*   sqlite3_test_control(SQLITE_TESTCTRL_SORTER_MMAP, db, nMax); */
3645     case SQLITE_TESTCTRL_SORTER_MMAP: {
3646       sqlite3 *db = va_arg(ap, sqlite3*);
3647       db->nMaxSorterMmap = va_arg(ap, int);
3648       break;
3649     }
3650 
3651     /*   sqlite3_test_control(SQLITE_TESTCTRL_ISINIT);
3652     **
3653     ** Return SQLITE_OK if SQLite has been initialized and SQLITE_ERROR if
3654     ** not.
3655     */
3656     case SQLITE_TESTCTRL_ISINIT: {
3657       if( sqlite3GlobalConfig.isInit==0 ) rc = SQLITE_ERROR;
3658       break;
3659     }
3660 
3661     /*  sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, db, dbName, onOff, tnum);
3662     **
3663     ** This test control is used to create imposter tables.  "db" is a pointer
3664     ** to the database connection.  dbName is the database name (ex: "main" or
3665     ** "temp") which will receive the imposter.  "onOff" turns imposter mode on
3666     ** or off.  "tnum" is the root page of the b-tree to which the imposter
3667     ** table should connect.
3668     **
3669     ** Enable imposter mode only when the schema has already been parsed.  Then
3670     ** run a single CREATE TABLE statement to construct the imposter table in
3671     ** the parsed schema.  Then turn imposter mode back off again.
3672     **
3673     ** If onOff==0 and tnum>0 then reset the schema for all databases, causing
3674     ** the schema to be reparsed the next time it is needed.  This has the
3675     ** effect of erasing all imposter tables.
3676     */
3677     case SQLITE_TESTCTRL_IMPOSTER: {
3678       sqlite3 *db = va_arg(ap, sqlite3*);
3679       sqlite3_mutex_enter(db->mutex);
3680       db->init.iDb = sqlite3FindDbName(db, va_arg(ap,const char*));
3681       db->init.busy = db->init.imposterTable = va_arg(ap,int);
3682       db->init.newTnum = va_arg(ap,int);
3683       if( db->init.busy==0 && db->init.newTnum>0 ){
3684         sqlite3ResetAllSchemasOfConnection(db);
3685       }
3686       sqlite3_mutex_leave(db->mutex);
3687       break;
3688     }
3689   }
3690   va_end(ap);
3691 #endif /* SQLITE_OMIT_BUILTIN_TEST */
3692   return rc;
3693 }
3694 
3695 /*
3696 ** This is a utility routine, useful to VFS implementations, that checks
3697 ** to see if a database file was a URI that contained a specific query
3698 ** parameter, and if so obtains the value of the query parameter.
3699 **
3700 ** The zFilename argument is the filename pointer passed into the xOpen()
3701 ** method of a VFS implementation.  The zParam argument is the name of the
3702 ** query parameter we seek.  This routine returns the value of the zParam
3703 ** parameter if it exists.  If the parameter does not exist, this routine
3704 ** returns a NULL pointer.
3705 */
3706 const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam){
3707   if( zFilename==0 || zParam==0 ) return 0;
3708   zFilename += sqlite3Strlen30(zFilename) + 1;
3709   while( zFilename[0] ){
3710     int x = strcmp(zFilename, zParam);
3711     zFilename += sqlite3Strlen30(zFilename) + 1;
3712     if( x==0 ) return zFilename;
3713     zFilename += sqlite3Strlen30(zFilename) + 1;
3714   }
3715   return 0;
3716 }
3717 
3718 /*
3719 ** Return a boolean value for a query parameter.
3720 */
3721 int sqlite3_uri_boolean(const char *zFilename, const char *zParam, int bDflt){
3722   const char *z = sqlite3_uri_parameter(zFilename, zParam);
3723   bDflt = bDflt!=0;
3724   return z ? sqlite3GetBoolean(z, bDflt) : bDflt;
3725 }
3726 
3727 /*
3728 ** Return a 64-bit integer value for a query parameter.
3729 */
3730 sqlite3_int64 sqlite3_uri_int64(
3731   const char *zFilename,    /* Filename as passed to xOpen */
3732   const char *zParam,       /* URI parameter sought */
3733   sqlite3_int64 bDflt       /* return if parameter is missing */
3734 ){
3735   const char *z = sqlite3_uri_parameter(zFilename, zParam);
3736   sqlite3_int64 v;
3737   if( z && sqlite3DecOrHexToI64(z, &v)==SQLITE_OK ){
3738     bDflt = v;
3739   }
3740   return bDflt;
3741 }
3742 
3743 /*
3744 ** Return the Btree pointer identified by zDbName.  Return NULL if not found.
3745 */
3746 Btree *sqlite3DbNameToBtree(sqlite3 *db, const char *zDbName){
3747   int i;
3748   for(i=0; i<db->nDb; i++){
3749     if( db->aDb[i].pBt
3750      && (zDbName==0 || sqlite3StrICmp(zDbName, db->aDb[i].zName)==0)
3751     ){
3752       return db->aDb[i].pBt;
3753     }
3754   }
3755   return 0;
3756 }
3757 
3758 /*
3759 ** Return the filename of the database associated with a database
3760 ** connection.
3761 */
3762 const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName){
3763   Btree *pBt;
3764 #ifdef SQLITE_ENABLE_API_ARMOR
3765   if( !sqlite3SafetyCheckOk(db) ){
3766     (void)SQLITE_MISUSE_BKPT;
3767     return 0;
3768   }
3769 #endif
3770   pBt = sqlite3DbNameToBtree(db, zDbName);
3771   return pBt ? sqlite3BtreeGetFilename(pBt) : 0;
3772 }
3773 
3774 /*
3775 ** Return 1 if database is read-only or 0 if read/write.  Return -1 if
3776 ** no such database exists.
3777 */
3778 int sqlite3_db_readonly(sqlite3 *db, const char *zDbName){
3779   Btree *pBt;
3780 #ifdef SQLITE_ENABLE_API_ARMOR
3781   if( !sqlite3SafetyCheckOk(db) ){
3782     (void)SQLITE_MISUSE_BKPT;
3783     return -1;
3784   }
3785 #endif
3786   pBt = sqlite3DbNameToBtree(db, zDbName);
3787   return pBt ? sqlite3BtreeIsReadonly(pBt) : -1;
3788 }
3789