xref: /sqlite-3.40.0/src/main.c (revision cb6acda9)
1 /*
2 ** 2001 September 15
3 **
4 ** The author disclaims copyright to this source code.  In place of
5 ** a legal notice, here is a blessing:
6 **
7 **    May you do good and not evil.
8 **    May you find forgiveness for yourself and forgive others.
9 **    May you share freely, never taking more than you give.
10 **
11 *************************************************************************
12 ** Main file for the SQLite library.  The routines in this file
13 ** implement the programmer interface to the library.  Routines in
14 ** other files are for internal use by SQLite and should not be
15 ** accessed by users of the library.
16 */
17 #include "sqliteInt.h"
18 
19 #ifdef SQLITE_ENABLE_FTS3
20 # include "fts3.h"
21 #endif
22 #ifdef SQLITE_ENABLE_RTREE
23 # include "rtree.h"
24 #endif
25 #ifdef SQLITE_ENABLE_ICU
26 # include "sqliteicu.h"
27 #endif
28 #ifdef SQLITE_ENABLE_JSON1
29 int sqlite3Json1Init(sqlite3*);
30 #endif
31 #ifdef SQLITE_ENABLE_STMTVTAB
32 int sqlite3StmtVtabInit(sqlite3*);
33 #endif
34 #ifdef SQLITE_ENABLE_FTS5
35 int sqlite3Fts5Init(sqlite3*);
36 #endif
37 
38 #ifndef SQLITE_AMALGAMATION
39 /* IMPLEMENTATION-OF: R-46656-45156 The sqlite3_version[] string constant
40 ** contains the text of SQLITE_VERSION macro.
41 */
42 const char sqlite3_version[] = SQLITE_VERSION;
43 #endif
44 
45 /* IMPLEMENTATION-OF: R-53536-42575 The sqlite3_libversion() function returns
46 ** a pointer to the to the sqlite3_version[] string constant.
47 */
48 const char *sqlite3_libversion(void){ return sqlite3_version; }
49 
50 /* IMPLEMENTATION-OF: R-25063-23286 The sqlite3_sourceid() function returns a
51 ** pointer to a string constant whose value is the same as the
52 ** SQLITE_SOURCE_ID C preprocessor macro. Except if SQLite is built using
53 ** an edited copy of the amalgamation, then the last four characters of
54 ** the hash might be different from SQLITE_SOURCE_ID.
55 */
56 const char *sqlite3_sourceid(void){ return SQLITE_SOURCE_ID; }
57 
58 /* IMPLEMENTATION-OF: R-35210-63508 The sqlite3_libversion_number() function
59 ** returns an integer equal to SQLITE_VERSION_NUMBER.
60 */
61 int sqlite3_libversion_number(void){ return SQLITE_VERSION_NUMBER; }
62 
63 /* IMPLEMENTATION-OF: R-20790-14025 The sqlite3_threadsafe() function returns
64 ** zero if and only if SQLite was compiled with mutexing code omitted due to
65 ** the SQLITE_THREADSAFE compile-time option being set to 0.
66 */
67 int sqlite3_threadsafe(void){ return SQLITE_THREADSAFE; }
68 
69 /*
70 ** When compiling the test fixture or with debugging enabled (on Win32),
71 ** this variable being set to non-zero will cause OSTRACE macros to emit
72 ** extra diagnostic information.
73 */
74 #ifdef SQLITE_HAVE_OS_TRACE
75 # ifndef SQLITE_DEBUG_OS_TRACE
76 #   define SQLITE_DEBUG_OS_TRACE 0
77 # endif
78   int sqlite3OSTrace = SQLITE_DEBUG_OS_TRACE;
79 #endif
80 
81 #if !defined(SQLITE_OMIT_TRACE) && defined(SQLITE_ENABLE_IOTRACE)
82 /*
83 ** If the following function pointer is not NULL and if
84 ** SQLITE_ENABLE_IOTRACE is enabled, then messages describing
85 ** I/O active are written using this function.  These messages
86 ** are intended for debugging activity only.
87 */
88 SQLITE_API void (SQLITE_CDECL *sqlite3IoTrace)(const char*, ...) = 0;
89 #endif
90 
91 /*
92 ** If the following global variable points to a string which is the
93 ** name of a directory, then that directory will be used to store
94 ** temporary files.
95 **
96 ** See also the "PRAGMA temp_store_directory" SQL command.
97 */
98 char *sqlite3_temp_directory = 0;
99 
100 /*
101 ** If the following global variable points to a string which is the
102 ** name of a directory, then that directory will be used to store
103 ** all database files specified with a relative pathname.
104 **
105 ** See also the "PRAGMA data_store_directory" SQL command.
106 */
107 char *sqlite3_data_directory = 0;
108 
109 /*
110 ** Initialize SQLite.
111 **
112 ** This routine must be called to initialize the memory allocation,
113 ** VFS, and mutex subsystems prior to doing any serious work with
114 ** SQLite.  But as long as you do not compile with SQLITE_OMIT_AUTOINIT
115 ** this routine will be called automatically by key routines such as
116 ** sqlite3_open().
117 **
118 ** This routine is a no-op except on its very first call for the process,
119 ** or for the first call after a call to sqlite3_shutdown.
120 **
121 ** The first thread to call this routine runs the initialization to
122 ** completion.  If subsequent threads call this routine before the first
123 ** thread has finished the initialization process, then the subsequent
124 ** threads must block until the first thread finishes with the initialization.
125 **
126 ** The first thread might call this routine recursively.  Recursive
127 ** calls to this routine should not block, of course.  Otherwise the
128 ** initialization process would never complete.
129 **
130 ** Let X be the first thread to enter this routine.  Let Y be some other
131 ** thread.  Then while the initial invocation of this routine by X is
132 ** incomplete, it is required that:
133 **
134 **    *  Calls to this routine from Y must block until the outer-most
135 **       call by X completes.
136 **
137 **    *  Recursive calls to this routine from thread X return immediately
138 **       without blocking.
139 */
140 int sqlite3_initialize(void){
141   MUTEX_LOGIC( sqlite3_mutex *pMaster; )       /* The main static mutex */
142   int rc;                                      /* Result code */
143 #ifdef SQLITE_EXTRA_INIT
144   int bRunExtraInit = 0;                       /* Extra initialization needed */
145 #endif
146 
147 #ifdef SQLITE_OMIT_WSD
148   rc = sqlite3_wsd_init(4096, 24);
149   if( rc!=SQLITE_OK ){
150     return rc;
151   }
152 #endif
153 
154   /* If the following assert() fails on some obscure processor/compiler
155   ** combination, the work-around is to set the correct pointer
156   ** size at compile-time using -DSQLITE_PTRSIZE=n compile-time option */
157   assert( SQLITE_PTRSIZE==sizeof(char*) );
158 
159   /* If SQLite is already completely initialized, then this call
160   ** to sqlite3_initialize() should be a no-op.  But the initialization
161   ** must be complete.  So isInit must not be set until the very end
162   ** of this routine.
163   */
164   if( sqlite3GlobalConfig.isInit ) return SQLITE_OK;
165 
166   /* Make sure the mutex subsystem is initialized.  If unable to
167   ** initialize the mutex subsystem, return early with the error.
168   ** If the system is so sick that we are unable to allocate a mutex,
169   ** there is not much SQLite is going to be able to do.
170   **
171   ** The mutex subsystem must take care of serializing its own
172   ** initialization.
173   */
174   rc = sqlite3MutexInit();
175   if( rc ) return rc;
176 
177   /* Initialize the malloc() system and the recursive pInitMutex mutex.
178   ** This operation is protected by the STATIC_MASTER mutex.  Note that
179   ** MutexAlloc() is called for a static mutex prior to initializing the
180   ** malloc subsystem - this implies that the allocation of a static
181   ** mutex must not require support from the malloc subsystem.
182   */
183   MUTEX_LOGIC( pMaster = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER); )
184   sqlite3_mutex_enter(pMaster);
185   sqlite3GlobalConfig.isMutexInit = 1;
186   if( !sqlite3GlobalConfig.isMallocInit ){
187     rc = sqlite3MallocInit();
188   }
189   if( rc==SQLITE_OK ){
190     sqlite3GlobalConfig.isMallocInit = 1;
191     if( !sqlite3GlobalConfig.pInitMutex ){
192       sqlite3GlobalConfig.pInitMutex =
193            sqlite3MutexAlloc(SQLITE_MUTEX_RECURSIVE);
194       if( sqlite3GlobalConfig.bCoreMutex && !sqlite3GlobalConfig.pInitMutex ){
195         rc = SQLITE_NOMEM_BKPT;
196       }
197     }
198   }
199   if( rc==SQLITE_OK ){
200     sqlite3GlobalConfig.nRefInitMutex++;
201   }
202   sqlite3_mutex_leave(pMaster);
203 
204   /* If rc is not SQLITE_OK at this point, then either the malloc
205   ** subsystem could not be initialized or the system failed to allocate
206   ** the pInitMutex mutex. Return an error in either case.  */
207   if( rc!=SQLITE_OK ){
208     return rc;
209   }
210 
211   /* Do the rest of the initialization under the recursive mutex so
212   ** that we will be able to handle recursive calls into
213   ** sqlite3_initialize().  The recursive calls normally come through
214   ** sqlite3_os_init() when it invokes sqlite3_vfs_register(), but other
215   ** recursive calls might also be possible.
216   **
217   ** IMPLEMENTATION-OF: R-00140-37445 SQLite automatically serializes calls
218   ** to the xInit method, so the xInit method need not be threadsafe.
219   **
220   ** The following mutex is what serializes access to the appdef pcache xInit
221   ** methods.  The sqlite3_pcache_methods.xInit() all is embedded in the
222   ** call to sqlite3PcacheInitialize().
223   */
224   sqlite3_mutex_enter(sqlite3GlobalConfig.pInitMutex);
225   if( sqlite3GlobalConfig.isInit==0 && sqlite3GlobalConfig.inProgress==0 ){
226     sqlite3GlobalConfig.inProgress = 1;
227 #ifdef SQLITE_ENABLE_SQLLOG
228     {
229       extern void sqlite3_init_sqllog(void);
230       sqlite3_init_sqllog();
231     }
232 #endif
233     memset(&sqlite3BuiltinFunctions, 0, sizeof(sqlite3BuiltinFunctions));
234     sqlite3RegisterBuiltinFunctions();
235     if( sqlite3GlobalConfig.isPCacheInit==0 ){
236       rc = sqlite3PcacheInitialize();
237     }
238     if( rc==SQLITE_OK ){
239       sqlite3GlobalConfig.isPCacheInit = 1;
240       rc = sqlite3OsInit();
241     }
242     if( rc==SQLITE_OK ){
243       sqlite3PCacheBufferSetup( sqlite3GlobalConfig.pPage,
244           sqlite3GlobalConfig.szPage, sqlite3GlobalConfig.nPage);
245       sqlite3GlobalConfig.isInit = 1;
246 #ifdef SQLITE_EXTRA_INIT
247       bRunExtraInit = 1;
248 #endif
249     }
250     sqlite3GlobalConfig.inProgress = 0;
251   }
252   sqlite3_mutex_leave(sqlite3GlobalConfig.pInitMutex);
253 
254   /* Go back under the static mutex and clean up the recursive
255   ** mutex to prevent a resource leak.
256   */
257   sqlite3_mutex_enter(pMaster);
258   sqlite3GlobalConfig.nRefInitMutex--;
259   if( sqlite3GlobalConfig.nRefInitMutex<=0 ){
260     assert( sqlite3GlobalConfig.nRefInitMutex==0 );
261     sqlite3_mutex_free(sqlite3GlobalConfig.pInitMutex);
262     sqlite3GlobalConfig.pInitMutex = 0;
263   }
264   sqlite3_mutex_leave(pMaster);
265 
266   /* The following is just a sanity check to make sure SQLite has
267   ** been compiled correctly.  It is important to run this code, but
268   ** we don't want to run it too often and soak up CPU cycles for no
269   ** reason.  So we run it once during initialization.
270   */
271 #ifndef NDEBUG
272 #ifndef SQLITE_OMIT_FLOATING_POINT
273   /* This section of code's only "output" is via assert() statements. */
274   if ( rc==SQLITE_OK ){
275     u64 x = (((u64)1)<<63)-1;
276     double y;
277     assert(sizeof(x)==8);
278     assert(sizeof(x)==sizeof(y));
279     memcpy(&y, &x, 8);
280     assert( sqlite3IsNaN(y) );
281   }
282 #endif
283 #endif
284 
285   /* Do extra initialization steps requested by the SQLITE_EXTRA_INIT
286   ** compile-time option.
287   */
288 #ifdef SQLITE_EXTRA_INIT
289   if( bRunExtraInit ){
290     int SQLITE_EXTRA_INIT(const char*);
291     rc = SQLITE_EXTRA_INIT(0);
292   }
293 #endif
294 
295   return rc;
296 }
297 
298 /*
299 ** Undo the effects of sqlite3_initialize().  Must not be called while
300 ** there are outstanding database connections or memory allocations or
301 ** while any part of SQLite is otherwise in use in any thread.  This
302 ** routine is not threadsafe.  But it is safe to invoke this routine
303 ** on when SQLite is already shut down.  If SQLite is already shut down
304 ** when this routine is invoked, then this routine is a harmless no-op.
305 */
306 int sqlite3_shutdown(void){
307 #ifdef SQLITE_OMIT_WSD
308   int rc = sqlite3_wsd_init(4096, 24);
309   if( rc!=SQLITE_OK ){
310     return rc;
311   }
312 #endif
313 
314   if( sqlite3GlobalConfig.isInit ){
315 #ifdef SQLITE_EXTRA_SHUTDOWN
316     void SQLITE_EXTRA_SHUTDOWN(void);
317     SQLITE_EXTRA_SHUTDOWN();
318 #endif
319     sqlite3_os_end();
320     sqlite3_reset_auto_extension();
321     sqlite3GlobalConfig.isInit = 0;
322   }
323   if( sqlite3GlobalConfig.isPCacheInit ){
324     sqlite3PcacheShutdown();
325     sqlite3GlobalConfig.isPCacheInit = 0;
326   }
327   if( sqlite3GlobalConfig.isMallocInit ){
328     sqlite3MallocEnd();
329     sqlite3GlobalConfig.isMallocInit = 0;
330 
331 #ifndef SQLITE_OMIT_SHUTDOWN_DIRECTORIES
332     /* The heap subsystem has now been shutdown and these values are supposed
333     ** to be NULL or point to memory that was obtained from sqlite3_malloc(),
334     ** which would rely on that heap subsystem; therefore, make sure these
335     ** values cannot refer to heap memory that was just invalidated when the
336     ** heap subsystem was shutdown.  This is only done if the current call to
337     ** this function resulted in the heap subsystem actually being shutdown.
338     */
339     sqlite3_data_directory = 0;
340     sqlite3_temp_directory = 0;
341 #endif
342   }
343   if( sqlite3GlobalConfig.isMutexInit ){
344     sqlite3MutexEnd();
345     sqlite3GlobalConfig.isMutexInit = 0;
346   }
347 
348   return SQLITE_OK;
349 }
350 
351 /*
352 ** This API allows applications to modify the global configuration of
353 ** the SQLite library at run-time.
354 **
355 ** This routine should only be called when there are no outstanding
356 ** database connections or memory allocations.  This routine is not
357 ** threadsafe.  Failure to heed these warnings can lead to unpredictable
358 ** behavior.
359 */
360 int sqlite3_config(int op, ...){
361   va_list ap;
362   int rc = SQLITE_OK;
363 
364   /* sqlite3_config() shall return SQLITE_MISUSE if it is invoked while
365   ** the SQLite library is in use. */
366   if( sqlite3GlobalConfig.isInit ) return SQLITE_MISUSE_BKPT;
367 
368   va_start(ap, op);
369   switch( op ){
370 
371     /* Mutex configuration options are only available in a threadsafe
372     ** compile.
373     */
374 #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0  /* IMP: R-54466-46756 */
375     case SQLITE_CONFIG_SINGLETHREAD: {
376       /* EVIDENCE-OF: R-02748-19096 This option sets the threading mode to
377       ** Single-thread. */
378       sqlite3GlobalConfig.bCoreMutex = 0;  /* Disable mutex on core */
379       sqlite3GlobalConfig.bFullMutex = 0;  /* Disable mutex on connections */
380       break;
381     }
382 #endif
383 #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-20520-54086 */
384     case SQLITE_CONFIG_MULTITHREAD: {
385       /* EVIDENCE-OF: R-14374-42468 This option sets the threading mode to
386       ** Multi-thread. */
387       sqlite3GlobalConfig.bCoreMutex = 1;  /* Enable mutex on core */
388       sqlite3GlobalConfig.bFullMutex = 0;  /* Disable mutex on connections */
389       break;
390     }
391 #endif
392 #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-59593-21810 */
393     case SQLITE_CONFIG_SERIALIZED: {
394       /* EVIDENCE-OF: R-41220-51800 This option sets the threading mode to
395       ** Serialized. */
396       sqlite3GlobalConfig.bCoreMutex = 1;  /* Enable mutex on core */
397       sqlite3GlobalConfig.bFullMutex = 1;  /* Enable mutex on connections */
398       break;
399     }
400 #endif
401 #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-63666-48755 */
402     case SQLITE_CONFIG_MUTEX: {
403       /* Specify an alternative mutex implementation */
404       sqlite3GlobalConfig.mutex = *va_arg(ap, sqlite3_mutex_methods*);
405       break;
406     }
407 #endif
408 #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-14450-37597 */
409     case SQLITE_CONFIG_GETMUTEX: {
410       /* Retrieve the current mutex implementation */
411       *va_arg(ap, sqlite3_mutex_methods*) = sqlite3GlobalConfig.mutex;
412       break;
413     }
414 #endif
415 
416     case SQLITE_CONFIG_MALLOC: {
417       /* EVIDENCE-OF: R-55594-21030 The SQLITE_CONFIG_MALLOC option takes a
418       ** single argument which is a pointer to an instance of the
419       ** sqlite3_mem_methods structure. The argument specifies alternative
420       ** low-level memory allocation routines to be used in place of the memory
421       ** allocation routines built into SQLite. */
422       sqlite3GlobalConfig.m = *va_arg(ap, sqlite3_mem_methods*);
423       break;
424     }
425     case SQLITE_CONFIG_GETMALLOC: {
426       /* EVIDENCE-OF: R-51213-46414 The SQLITE_CONFIG_GETMALLOC option takes a
427       ** single argument which is a pointer to an instance of the
428       ** sqlite3_mem_methods structure. The sqlite3_mem_methods structure is
429       ** filled with the currently defined memory allocation routines. */
430       if( sqlite3GlobalConfig.m.xMalloc==0 ) sqlite3MemSetDefault();
431       *va_arg(ap, sqlite3_mem_methods*) = sqlite3GlobalConfig.m;
432       break;
433     }
434     case SQLITE_CONFIG_MEMSTATUS: {
435       /* EVIDENCE-OF: R-61275-35157 The SQLITE_CONFIG_MEMSTATUS option takes
436       ** single argument of type int, interpreted as a boolean, which enables
437       ** or disables the collection of memory allocation statistics. */
438       sqlite3GlobalConfig.bMemstat = va_arg(ap, int);
439       break;
440     }
441     case SQLITE_CONFIG_SMALL_MALLOC: {
442       sqlite3GlobalConfig.bSmallMalloc = va_arg(ap, int);
443       break;
444     }
445     case SQLITE_CONFIG_PAGECACHE: {
446       /* EVIDENCE-OF: R-18761-36601 There are three arguments to
447       ** SQLITE_CONFIG_PAGECACHE: A pointer to 8-byte aligned memory (pMem),
448       ** the size of each page cache line (sz), and the number of cache lines
449       ** (N). */
450       sqlite3GlobalConfig.pPage = va_arg(ap, void*);
451       sqlite3GlobalConfig.szPage = va_arg(ap, int);
452       sqlite3GlobalConfig.nPage = va_arg(ap, int);
453       break;
454     }
455     case SQLITE_CONFIG_PCACHE_HDRSZ: {
456       /* EVIDENCE-OF: R-39100-27317 The SQLITE_CONFIG_PCACHE_HDRSZ option takes
457       ** a single parameter which is a pointer to an integer and writes into
458       ** that integer the number of extra bytes per page required for each page
459       ** in SQLITE_CONFIG_PAGECACHE. */
460       *va_arg(ap, int*) =
461           sqlite3HeaderSizeBtree() +
462           sqlite3HeaderSizePcache() +
463           sqlite3HeaderSizePcache1();
464       break;
465     }
466 
467     case SQLITE_CONFIG_PCACHE: {
468       /* no-op */
469       break;
470     }
471     case SQLITE_CONFIG_GETPCACHE: {
472       /* now an error */
473       rc = SQLITE_ERROR;
474       break;
475     }
476 
477     case SQLITE_CONFIG_PCACHE2: {
478       /* EVIDENCE-OF: R-63325-48378 The SQLITE_CONFIG_PCACHE2 option takes a
479       ** single argument which is a pointer to an sqlite3_pcache_methods2
480       ** object. This object specifies the interface to a custom page cache
481       ** implementation. */
482       sqlite3GlobalConfig.pcache2 = *va_arg(ap, sqlite3_pcache_methods2*);
483       break;
484     }
485     case SQLITE_CONFIG_GETPCACHE2: {
486       /* EVIDENCE-OF: R-22035-46182 The SQLITE_CONFIG_GETPCACHE2 option takes a
487       ** single argument which is a pointer to an sqlite3_pcache_methods2
488       ** object. SQLite copies of the current page cache implementation into
489       ** that object. */
490       if( sqlite3GlobalConfig.pcache2.xInit==0 ){
491         sqlite3PCacheSetDefault();
492       }
493       *va_arg(ap, sqlite3_pcache_methods2*) = sqlite3GlobalConfig.pcache2;
494       break;
495     }
496 
497 /* EVIDENCE-OF: R-06626-12911 The SQLITE_CONFIG_HEAP option is only
498 ** available if SQLite is compiled with either SQLITE_ENABLE_MEMSYS3 or
499 ** SQLITE_ENABLE_MEMSYS5 and returns SQLITE_ERROR if invoked otherwise. */
500 #if defined(SQLITE_ENABLE_MEMSYS3) || defined(SQLITE_ENABLE_MEMSYS5)
501     case SQLITE_CONFIG_HEAP: {
502       /* EVIDENCE-OF: R-19854-42126 There are three arguments to
503       ** SQLITE_CONFIG_HEAP: An 8-byte aligned pointer to the memory, the
504       ** number of bytes in the memory buffer, and the minimum allocation size.
505       */
506       sqlite3GlobalConfig.pHeap = va_arg(ap, void*);
507       sqlite3GlobalConfig.nHeap = va_arg(ap, int);
508       sqlite3GlobalConfig.mnReq = va_arg(ap, int);
509 
510       if( sqlite3GlobalConfig.mnReq<1 ){
511         sqlite3GlobalConfig.mnReq = 1;
512       }else if( sqlite3GlobalConfig.mnReq>(1<<12) ){
513         /* cap min request size at 2^12 */
514         sqlite3GlobalConfig.mnReq = (1<<12);
515       }
516 
517       if( sqlite3GlobalConfig.pHeap==0 ){
518         /* EVIDENCE-OF: R-49920-60189 If the first pointer (the memory pointer)
519         ** is NULL, then SQLite reverts to using its default memory allocator
520         ** (the system malloc() implementation), undoing any prior invocation of
521         ** SQLITE_CONFIG_MALLOC.
522         **
523         ** Setting sqlite3GlobalConfig.m to all zeros will cause malloc to
524         ** revert to its default implementation when sqlite3_initialize() is run
525         */
526         memset(&sqlite3GlobalConfig.m, 0, sizeof(sqlite3GlobalConfig.m));
527       }else{
528         /* EVIDENCE-OF: R-61006-08918 If the memory pointer is not NULL then the
529         ** alternative memory allocator is engaged to handle all of SQLites
530         ** memory allocation needs. */
531 #ifdef SQLITE_ENABLE_MEMSYS3
532         sqlite3GlobalConfig.m = *sqlite3MemGetMemsys3();
533 #endif
534 #ifdef SQLITE_ENABLE_MEMSYS5
535         sqlite3GlobalConfig.m = *sqlite3MemGetMemsys5();
536 #endif
537       }
538       break;
539     }
540 #endif
541 
542     case SQLITE_CONFIG_LOOKASIDE: {
543       sqlite3GlobalConfig.szLookaside = va_arg(ap, int);
544       sqlite3GlobalConfig.nLookaside = va_arg(ap, int);
545       break;
546     }
547 
548     /* Record a pointer to the logger function and its first argument.
549     ** The default is NULL.  Logging is disabled if the function pointer is
550     ** NULL.
551     */
552     case SQLITE_CONFIG_LOG: {
553       /* MSVC is picky about pulling func ptrs from va lists.
554       ** http://support.microsoft.com/kb/47961
555       ** sqlite3GlobalConfig.xLog = va_arg(ap, void(*)(void*,int,const char*));
556       */
557       typedef void(*LOGFUNC_t)(void*,int,const char*);
558       sqlite3GlobalConfig.xLog = va_arg(ap, LOGFUNC_t);
559       sqlite3GlobalConfig.pLogArg = va_arg(ap, void*);
560       break;
561     }
562 
563     /* EVIDENCE-OF: R-55548-33817 The compile-time setting for URI filenames
564     ** can be changed at start-time using the
565     ** sqlite3_config(SQLITE_CONFIG_URI,1) or
566     ** sqlite3_config(SQLITE_CONFIG_URI,0) configuration calls.
567     */
568     case SQLITE_CONFIG_URI: {
569       /* EVIDENCE-OF: R-25451-61125 The SQLITE_CONFIG_URI option takes a single
570       ** argument of type int. If non-zero, then URI handling is globally
571       ** enabled. If the parameter is zero, then URI handling is globally
572       ** disabled. */
573       sqlite3GlobalConfig.bOpenUri = va_arg(ap, int);
574       break;
575     }
576 
577     case SQLITE_CONFIG_COVERING_INDEX_SCAN: {
578       /* EVIDENCE-OF: R-36592-02772 The SQLITE_CONFIG_COVERING_INDEX_SCAN
579       ** option takes a single integer argument which is interpreted as a
580       ** boolean in order to enable or disable the use of covering indices for
581       ** full table scans in the query optimizer. */
582       sqlite3GlobalConfig.bUseCis = va_arg(ap, int);
583       break;
584     }
585 
586 #ifdef SQLITE_ENABLE_SQLLOG
587     case SQLITE_CONFIG_SQLLOG: {
588       typedef void(*SQLLOGFUNC_t)(void*, sqlite3*, const char*, int);
589       sqlite3GlobalConfig.xSqllog = va_arg(ap, SQLLOGFUNC_t);
590       sqlite3GlobalConfig.pSqllogArg = va_arg(ap, void *);
591       break;
592     }
593 #endif
594 
595     case SQLITE_CONFIG_MMAP_SIZE: {
596       /* EVIDENCE-OF: R-58063-38258 SQLITE_CONFIG_MMAP_SIZE takes two 64-bit
597       ** integer (sqlite3_int64) values that are the default mmap size limit
598       ** (the default setting for PRAGMA mmap_size) and the maximum allowed
599       ** mmap size limit. */
600       sqlite3_int64 szMmap = va_arg(ap, sqlite3_int64);
601       sqlite3_int64 mxMmap = va_arg(ap, sqlite3_int64);
602       /* EVIDENCE-OF: R-53367-43190 If either argument to this option is
603       ** negative, then that argument is changed to its compile-time default.
604       **
605       ** EVIDENCE-OF: R-34993-45031 The maximum allowed mmap size will be
606       ** silently truncated if necessary so that it does not exceed the
607       ** compile-time maximum mmap size set by the SQLITE_MAX_MMAP_SIZE
608       ** compile-time option.
609       */
610       if( mxMmap<0 || mxMmap>SQLITE_MAX_MMAP_SIZE ){
611         mxMmap = SQLITE_MAX_MMAP_SIZE;
612       }
613       if( szMmap<0 ) szMmap = SQLITE_DEFAULT_MMAP_SIZE;
614       if( szMmap>mxMmap) szMmap = mxMmap;
615       sqlite3GlobalConfig.mxMmap = mxMmap;
616       sqlite3GlobalConfig.szMmap = szMmap;
617       break;
618     }
619 
620 #if SQLITE_OS_WIN && defined(SQLITE_WIN32_MALLOC) /* IMP: R-04780-55815 */
621     case SQLITE_CONFIG_WIN32_HEAPSIZE: {
622       /* EVIDENCE-OF: R-34926-03360 SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit
623       ** unsigned integer value that specifies the maximum size of the created
624       ** heap. */
625       sqlite3GlobalConfig.nHeap = va_arg(ap, int);
626       break;
627     }
628 #endif
629 
630     case SQLITE_CONFIG_PMASZ: {
631       sqlite3GlobalConfig.szPma = va_arg(ap, unsigned int);
632       break;
633     }
634 
635     case SQLITE_CONFIG_STMTJRNL_SPILL: {
636       sqlite3GlobalConfig.nStmtSpill = va_arg(ap, int);
637       break;
638     }
639 
640     default: {
641       rc = SQLITE_ERROR;
642       break;
643     }
644   }
645   va_end(ap);
646   return rc;
647 }
648 
649 /*
650 ** Set up the lookaside buffers for a database connection.
651 ** Return SQLITE_OK on success.
652 ** If lookaside is already active, return SQLITE_BUSY.
653 **
654 ** The sz parameter is the number of bytes in each lookaside slot.
655 ** The cnt parameter is the number of slots.  If pStart is NULL the
656 ** space for the lookaside memory is obtained from sqlite3_malloc().
657 ** If pStart is not NULL then it is sz*cnt bytes of memory to use for
658 ** the lookaside memory.
659 */
660 static int setupLookaside(sqlite3 *db, void *pBuf, int sz, int cnt){
661 #ifndef SQLITE_OMIT_LOOKASIDE
662   void *pStart;
663 
664   if( sqlite3LookasideUsed(db,0)>0 ){
665     return SQLITE_BUSY;
666   }
667   /* Free any existing lookaside buffer for this handle before
668   ** allocating a new one so we don't have to have space for
669   ** both at the same time.
670   */
671   if( db->lookaside.bMalloced ){
672     sqlite3_free(db->lookaside.pStart);
673   }
674   /* The size of a lookaside slot after ROUNDDOWN8 needs to be larger
675   ** than a pointer to be useful.
676   */
677   sz = ROUNDDOWN8(sz);  /* IMP: R-33038-09382 */
678   if( sz<=(int)sizeof(LookasideSlot*) ) sz = 0;
679   if( cnt<0 ) cnt = 0;
680   if( sz==0 || cnt==0 ){
681     sz = 0;
682     pStart = 0;
683   }else if( pBuf==0 ){
684     sqlite3BeginBenignMalloc();
685     pStart = sqlite3Malloc( sz*cnt );  /* IMP: R-61949-35727 */
686     sqlite3EndBenignMalloc();
687     if( pStart ) cnt = sqlite3MallocSize(pStart)/sz;
688   }else{
689     pStart = pBuf;
690   }
691   db->lookaside.pStart = pStart;
692   db->lookaside.pInit = 0;
693   db->lookaside.pFree = 0;
694   db->lookaside.sz = (u16)sz;
695   if( pStart ){
696     int i;
697     LookasideSlot *p;
698     assert( sz > (int)sizeof(LookasideSlot*) );
699     db->lookaside.nSlot = cnt;
700     p = (LookasideSlot*)pStart;
701     for(i=cnt-1; i>=0; i--){
702       p->pNext = db->lookaside.pInit;
703       db->lookaside.pInit = p;
704       p = (LookasideSlot*)&((u8*)p)[sz];
705     }
706     db->lookaside.pEnd = p;
707     db->lookaside.bDisable = 0;
708     db->lookaside.bMalloced = pBuf==0 ?1:0;
709   }else{
710     db->lookaside.pStart = db;
711     db->lookaside.pEnd = db;
712     db->lookaside.bDisable = 1;
713     db->lookaside.bMalloced = 0;
714     db->lookaside.nSlot = 0;
715   }
716 #endif /* SQLITE_OMIT_LOOKASIDE */
717   return SQLITE_OK;
718 }
719 
720 /*
721 ** Return the mutex associated with a database connection.
722 */
723 sqlite3_mutex *sqlite3_db_mutex(sqlite3 *db){
724 #ifdef SQLITE_ENABLE_API_ARMOR
725   if( !sqlite3SafetyCheckOk(db) ){
726     (void)SQLITE_MISUSE_BKPT;
727     return 0;
728   }
729 #endif
730   return db->mutex;
731 }
732 
733 /*
734 ** Free up as much memory as we can from the given database
735 ** connection.
736 */
737 int sqlite3_db_release_memory(sqlite3 *db){
738   int i;
739 
740 #ifdef SQLITE_ENABLE_API_ARMOR
741   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
742 #endif
743   sqlite3_mutex_enter(db->mutex);
744   sqlite3BtreeEnterAll(db);
745   for(i=0; i<db->nDb; i++){
746     Btree *pBt = db->aDb[i].pBt;
747     if( pBt ){
748       Pager *pPager = sqlite3BtreePager(pBt);
749       sqlite3PagerShrink(pPager);
750     }
751   }
752   sqlite3BtreeLeaveAll(db);
753   sqlite3_mutex_leave(db->mutex);
754   return SQLITE_OK;
755 }
756 
757 /*
758 ** Flush any dirty pages in the pager-cache for any attached database
759 ** to disk.
760 */
761 int sqlite3_db_cacheflush(sqlite3 *db){
762   int i;
763   int rc = SQLITE_OK;
764   int bSeenBusy = 0;
765 
766 #ifdef SQLITE_ENABLE_API_ARMOR
767   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
768 #endif
769   sqlite3_mutex_enter(db->mutex);
770   sqlite3BtreeEnterAll(db);
771   for(i=0; rc==SQLITE_OK && i<db->nDb; i++){
772     Btree *pBt = db->aDb[i].pBt;
773     if( pBt && sqlite3BtreeIsInTrans(pBt) ){
774       Pager *pPager = sqlite3BtreePager(pBt);
775       rc = sqlite3PagerFlush(pPager);
776       if( rc==SQLITE_BUSY ){
777         bSeenBusy = 1;
778         rc = SQLITE_OK;
779       }
780     }
781   }
782   sqlite3BtreeLeaveAll(db);
783   sqlite3_mutex_leave(db->mutex);
784   return ((rc==SQLITE_OK && bSeenBusy) ? SQLITE_BUSY : rc);
785 }
786 
787 /*
788 ** Configuration settings for an individual database connection
789 */
790 int sqlite3_db_config(sqlite3 *db, int op, ...){
791   va_list ap;
792   int rc;
793   va_start(ap, op);
794   switch( op ){
795     case SQLITE_DBCONFIG_MAINDBNAME: {
796       /* IMP: R-06824-28531 */
797       /* IMP: R-36257-52125 */
798       db->aDb[0].zDbSName = va_arg(ap,char*);
799       rc = SQLITE_OK;
800       break;
801     }
802     case SQLITE_DBCONFIG_LOOKASIDE: {
803       void *pBuf = va_arg(ap, void*); /* IMP: R-26835-10964 */
804       int sz = va_arg(ap, int);       /* IMP: R-47871-25994 */
805       int cnt = va_arg(ap, int);      /* IMP: R-04460-53386 */
806       rc = setupLookaside(db, pBuf, sz, cnt);
807       break;
808     }
809     default: {
810       static const struct {
811         int op;      /* The opcode */
812         u32 mask;    /* Mask of the bit in sqlite3.flags to set/clear */
813       } aFlagOp[] = {
814         { SQLITE_DBCONFIG_ENABLE_FKEY,           SQLITE_ForeignKeys    },
815         { SQLITE_DBCONFIG_ENABLE_TRIGGER,        SQLITE_EnableTrigger  },
816         { SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER, SQLITE_Fts3Tokenizer  },
817         { SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION, SQLITE_LoadExtension  },
818         { SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE,      SQLITE_NoCkptOnClose  },
819         { SQLITE_DBCONFIG_ENABLE_QPSG,           SQLITE_EnableQPSG     },
820       };
821       unsigned int i;
822       rc = SQLITE_ERROR; /* IMP: R-42790-23372 */
823       for(i=0; i<ArraySize(aFlagOp); i++){
824         if( aFlagOp[i].op==op ){
825           int onoff = va_arg(ap, int);
826           int *pRes = va_arg(ap, int*);
827           u32 oldFlags = db->flags;
828           if( onoff>0 ){
829             db->flags |= aFlagOp[i].mask;
830           }else if( onoff==0 ){
831             db->flags &= ~aFlagOp[i].mask;
832           }
833           if( oldFlags!=db->flags ){
834             sqlite3ExpirePreparedStatements(db);
835           }
836           if( pRes ){
837             *pRes = (db->flags & aFlagOp[i].mask)!=0;
838           }
839           rc = SQLITE_OK;
840           break;
841         }
842       }
843       break;
844     }
845   }
846   va_end(ap);
847   return rc;
848 }
849 
850 
851 /*
852 ** Return true if the buffer z[0..n-1] contains all spaces.
853 */
854 static int allSpaces(const char *z, int n){
855   while( n>0 && z[n-1]==' ' ){ n--; }
856   return n==0;
857 }
858 
859 /*
860 ** This is the default collating function named "BINARY" which is always
861 ** available.
862 **
863 ** If the padFlag argument is not NULL then space padding at the end
864 ** of strings is ignored.  This implements the RTRIM collation.
865 */
866 static int binCollFunc(
867   void *padFlag,
868   int nKey1, const void *pKey1,
869   int nKey2, const void *pKey2
870 ){
871   int rc, n;
872   n = nKey1<nKey2 ? nKey1 : nKey2;
873   /* EVIDENCE-OF: R-65033-28449 The built-in BINARY collation compares
874   ** strings byte by byte using the memcmp() function from the standard C
875   ** library. */
876   assert( pKey1 && pKey2 );
877   rc = memcmp(pKey1, pKey2, n);
878   if( rc==0 ){
879     if( padFlag
880      && allSpaces(((char*)pKey1)+n, nKey1-n)
881      && allSpaces(((char*)pKey2)+n, nKey2-n)
882     ){
883       /* EVIDENCE-OF: R-31624-24737 RTRIM is like BINARY except that extra
884       ** spaces at the end of either string do not change the result. In other
885       ** words, strings will compare equal to one another as long as they
886       ** differ only in the number of spaces at the end.
887       */
888     }else{
889       rc = nKey1 - nKey2;
890     }
891   }
892   return rc;
893 }
894 
895 /*
896 ** Another built-in collating sequence: NOCASE.
897 **
898 ** This collating sequence is intended to be used for "case independent
899 ** comparison". SQLite's knowledge of upper and lower case equivalents
900 ** extends only to the 26 characters used in the English language.
901 **
902 ** At the moment there is only a UTF-8 implementation.
903 */
904 static int nocaseCollatingFunc(
905   void *NotUsed,
906   int nKey1, const void *pKey1,
907   int nKey2, const void *pKey2
908 ){
909   int r = sqlite3StrNICmp(
910       (const char *)pKey1, (const char *)pKey2, (nKey1<nKey2)?nKey1:nKey2);
911   UNUSED_PARAMETER(NotUsed);
912   if( 0==r ){
913     r = nKey1-nKey2;
914   }
915   return r;
916 }
917 
918 /*
919 ** Return the ROWID of the most recent insert
920 */
921 sqlite_int64 sqlite3_last_insert_rowid(sqlite3 *db){
922 #ifdef SQLITE_ENABLE_API_ARMOR
923   if( !sqlite3SafetyCheckOk(db) ){
924     (void)SQLITE_MISUSE_BKPT;
925     return 0;
926   }
927 #endif
928   return db->lastRowid;
929 }
930 
931 /*
932 ** Set the value returned by the sqlite3_last_insert_rowid() API function.
933 */
934 void sqlite3_set_last_insert_rowid(sqlite3 *db, sqlite3_int64 iRowid){
935 #ifdef SQLITE_ENABLE_API_ARMOR
936   if( !sqlite3SafetyCheckOk(db) ){
937     (void)SQLITE_MISUSE_BKPT;
938     return;
939   }
940 #endif
941   sqlite3_mutex_enter(db->mutex);
942   db->lastRowid = iRowid;
943   sqlite3_mutex_leave(db->mutex);
944 }
945 
946 /*
947 ** Return the number of changes in the most recent call to sqlite3_exec().
948 */
949 int sqlite3_changes(sqlite3 *db){
950 #ifdef SQLITE_ENABLE_API_ARMOR
951   if( !sqlite3SafetyCheckOk(db) ){
952     (void)SQLITE_MISUSE_BKPT;
953     return 0;
954   }
955 #endif
956   return db->nChange;
957 }
958 
959 /*
960 ** Return the number of changes since the database handle was opened.
961 */
962 int sqlite3_total_changes(sqlite3 *db){
963 #ifdef SQLITE_ENABLE_API_ARMOR
964   if( !sqlite3SafetyCheckOk(db) ){
965     (void)SQLITE_MISUSE_BKPT;
966     return 0;
967   }
968 #endif
969   return db->nTotalChange;
970 }
971 
972 /*
973 ** Close all open savepoints. This function only manipulates fields of the
974 ** database handle object, it does not close any savepoints that may be open
975 ** at the b-tree/pager level.
976 */
977 void sqlite3CloseSavepoints(sqlite3 *db){
978   while( db->pSavepoint ){
979     Savepoint *pTmp = db->pSavepoint;
980     db->pSavepoint = pTmp->pNext;
981     sqlite3DbFree(db, pTmp);
982   }
983   db->nSavepoint = 0;
984   db->nStatement = 0;
985   db->isTransactionSavepoint = 0;
986 }
987 
988 /*
989 ** Invoke the destructor function associated with FuncDef p, if any. Except,
990 ** if this is not the last copy of the function, do not invoke it. Multiple
991 ** copies of a single function are created when create_function() is called
992 ** with SQLITE_ANY as the encoding.
993 */
994 static void functionDestroy(sqlite3 *db, FuncDef *p){
995   FuncDestructor *pDestructor = p->u.pDestructor;
996   if( pDestructor ){
997     pDestructor->nRef--;
998     if( pDestructor->nRef==0 ){
999       pDestructor->xDestroy(pDestructor->pUserData);
1000       sqlite3DbFree(db, pDestructor);
1001     }
1002   }
1003 }
1004 
1005 /*
1006 ** Disconnect all sqlite3_vtab objects that belong to database connection
1007 ** db. This is called when db is being closed.
1008 */
1009 static void disconnectAllVtab(sqlite3 *db){
1010 #ifndef SQLITE_OMIT_VIRTUALTABLE
1011   int i;
1012   HashElem *p;
1013   sqlite3BtreeEnterAll(db);
1014   for(i=0; i<db->nDb; i++){
1015     Schema *pSchema = db->aDb[i].pSchema;
1016     if( db->aDb[i].pSchema ){
1017       for(p=sqliteHashFirst(&pSchema->tblHash); p; p=sqliteHashNext(p)){
1018         Table *pTab = (Table *)sqliteHashData(p);
1019         if( IsVirtual(pTab) ) sqlite3VtabDisconnect(db, pTab);
1020       }
1021     }
1022   }
1023   for(p=sqliteHashFirst(&db->aModule); p; p=sqliteHashNext(p)){
1024     Module *pMod = (Module *)sqliteHashData(p);
1025     if( pMod->pEpoTab ){
1026       sqlite3VtabDisconnect(db, pMod->pEpoTab);
1027     }
1028   }
1029   sqlite3VtabUnlockList(db);
1030   sqlite3BtreeLeaveAll(db);
1031 #else
1032   UNUSED_PARAMETER(db);
1033 #endif
1034 }
1035 
1036 /*
1037 ** Return TRUE if database connection db has unfinalized prepared
1038 ** statements or unfinished sqlite3_backup objects.
1039 */
1040 static int connectionIsBusy(sqlite3 *db){
1041   int j;
1042   assert( sqlite3_mutex_held(db->mutex) );
1043   if( db->pVdbe ) return 1;
1044   for(j=0; j<db->nDb; j++){
1045     Btree *pBt = db->aDb[j].pBt;
1046     if( pBt && sqlite3BtreeIsInBackup(pBt) ) return 1;
1047   }
1048   return 0;
1049 }
1050 
1051 /*
1052 ** Close an existing SQLite database
1053 */
1054 static int sqlite3Close(sqlite3 *db, int forceZombie){
1055   if( !db ){
1056     /* EVIDENCE-OF: R-63257-11740 Calling sqlite3_close() or
1057     ** sqlite3_close_v2() with a NULL pointer argument is a harmless no-op. */
1058     return SQLITE_OK;
1059   }
1060   if( !sqlite3SafetyCheckSickOrOk(db) ){
1061     return SQLITE_MISUSE_BKPT;
1062   }
1063   sqlite3_mutex_enter(db->mutex);
1064   if( db->mTrace & SQLITE_TRACE_CLOSE ){
1065     db->xTrace(SQLITE_TRACE_CLOSE, db->pTraceArg, db, 0);
1066   }
1067 
1068   /* Force xDisconnect calls on all virtual tables */
1069   disconnectAllVtab(db);
1070 
1071   /* If a transaction is open, the disconnectAllVtab() call above
1072   ** will not have called the xDisconnect() method on any virtual
1073   ** tables in the db->aVTrans[] array. The following sqlite3VtabRollback()
1074   ** call will do so. We need to do this before the check for active
1075   ** SQL statements below, as the v-table implementation may be storing
1076   ** some prepared statements internally.
1077   */
1078   sqlite3VtabRollback(db);
1079 
1080   /* Legacy behavior (sqlite3_close() behavior) is to return
1081   ** SQLITE_BUSY if the connection can not be closed immediately.
1082   */
1083   if( !forceZombie && connectionIsBusy(db) ){
1084     sqlite3ErrorWithMsg(db, SQLITE_BUSY, "unable to close due to unfinalized "
1085        "statements or unfinished backups");
1086     sqlite3_mutex_leave(db->mutex);
1087     return SQLITE_BUSY;
1088   }
1089 
1090 #ifdef SQLITE_ENABLE_SQLLOG
1091   if( sqlite3GlobalConfig.xSqllog ){
1092     /* Closing the handle. Fourth parameter is passed the value 2. */
1093     sqlite3GlobalConfig.xSqllog(sqlite3GlobalConfig.pSqllogArg, db, 0, 2);
1094   }
1095 #endif
1096 
1097   /* Convert the connection into a zombie and then close it.
1098   */
1099   db->magic = SQLITE_MAGIC_ZOMBIE;
1100   sqlite3LeaveMutexAndCloseZombie(db);
1101   return SQLITE_OK;
1102 }
1103 
1104 /*
1105 ** Two variations on the public interface for closing a database
1106 ** connection. The sqlite3_close() version returns SQLITE_BUSY and
1107 ** leaves the connection option if there are unfinalized prepared
1108 ** statements or unfinished sqlite3_backups.  The sqlite3_close_v2()
1109 ** version forces the connection to become a zombie if there are
1110 ** unclosed resources, and arranges for deallocation when the last
1111 ** prepare statement or sqlite3_backup closes.
1112 */
1113 int sqlite3_close(sqlite3 *db){ return sqlite3Close(db,0); }
1114 int sqlite3_close_v2(sqlite3 *db){ return sqlite3Close(db,1); }
1115 
1116 
1117 /*
1118 ** Close the mutex on database connection db.
1119 **
1120 ** Furthermore, if database connection db is a zombie (meaning that there
1121 ** has been a prior call to sqlite3_close(db) or sqlite3_close_v2(db)) and
1122 ** every sqlite3_stmt has now been finalized and every sqlite3_backup has
1123 ** finished, then free all resources.
1124 */
1125 void sqlite3LeaveMutexAndCloseZombie(sqlite3 *db){
1126   HashElem *i;                    /* Hash table iterator */
1127   int j;
1128 
1129   /* If there are outstanding sqlite3_stmt or sqlite3_backup objects
1130   ** or if the connection has not yet been closed by sqlite3_close_v2(),
1131   ** then just leave the mutex and return.
1132   */
1133   if( db->magic!=SQLITE_MAGIC_ZOMBIE || connectionIsBusy(db) ){
1134     sqlite3_mutex_leave(db->mutex);
1135     return;
1136   }
1137 
1138   /* If we reach this point, it means that the database connection has
1139   ** closed all sqlite3_stmt and sqlite3_backup objects and has been
1140   ** passed to sqlite3_close (meaning that it is a zombie).  Therefore,
1141   ** go ahead and free all resources.
1142   */
1143 
1144   /* If a transaction is open, roll it back. This also ensures that if
1145   ** any database schemas have been modified by an uncommitted transaction
1146   ** they are reset. And that the required b-tree mutex is held to make
1147   ** the pager rollback and schema reset an atomic operation. */
1148   sqlite3RollbackAll(db, SQLITE_OK);
1149 
1150   /* Free any outstanding Savepoint structures. */
1151   sqlite3CloseSavepoints(db);
1152 
1153   /* Close all database connections */
1154   for(j=0; j<db->nDb; j++){
1155     struct Db *pDb = &db->aDb[j];
1156     if( pDb->pBt ){
1157       sqlite3BtreeClose(pDb->pBt);
1158       pDb->pBt = 0;
1159       if( j!=1 ){
1160         pDb->pSchema = 0;
1161       }
1162     }
1163   }
1164   /* Clear the TEMP schema separately and last */
1165   if( db->aDb[1].pSchema ){
1166     sqlite3SchemaClear(db->aDb[1].pSchema);
1167   }
1168   sqlite3VtabUnlockList(db);
1169 
1170   /* Free up the array of auxiliary databases */
1171   sqlite3CollapseDatabaseArray(db);
1172   assert( db->nDb<=2 );
1173   assert( db->aDb==db->aDbStatic );
1174 
1175   /* Tell the code in notify.c that the connection no longer holds any
1176   ** locks and does not require any further unlock-notify callbacks.
1177   */
1178   sqlite3ConnectionClosed(db);
1179 
1180   for(i=sqliteHashFirst(&db->aFunc); i; i=sqliteHashNext(i)){
1181     FuncDef *pNext, *p;
1182     p = sqliteHashData(i);
1183     do{
1184       functionDestroy(db, p);
1185       pNext = p->pNext;
1186       sqlite3DbFree(db, p);
1187       p = pNext;
1188     }while( p );
1189   }
1190   sqlite3HashClear(&db->aFunc);
1191   for(i=sqliteHashFirst(&db->aCollSeq); i; i=sqliteHashNext(i)){
1192     CollSeq *pColl = (CollSeq *)sqliteHashData(i);
1193     /* Invoke any destructors registered for collation sequence user data. */
1194     for(j=0; j<3; j++){
1195       if( pColl[j].xDel ){
1196         pColl[j].xDel(pColl[j].pUser);
1197       }
1198     }
1199     sqlite3DbFree(db, pColl);
1200   }
1201   sqlite3HashClear(&db->aCollSeq);
1202 #ifndef SQLITE_OMIT_VIRTUALTABLE
1203   for(i=sqliteHashFirst(&db->aModule); i; i=sqliteHashNext(i)){
1204     Module *pMod = (Module *)sqliteHashData(i);
1205     if( pMod->xDestroy ){
1206       pMod->xDestroy(pMod->pAux);
1207     }
1208     sqlite3VtabEponymousTableClear(db, pMod);
1209     sqlite3DbFree(db, pMod);
1210   }
1211   sqlite3HashClear(&db->aModule);
1212 #endif
1213 
1214   sqlite3Error(db, SQLITE_OK); /* Deallocates any cached error strings. */
1215   sqlite3ValueFree(db->pErr);
1216   sqlite3CloseExtensions(db);
1217 #if SQLITE_USER_AUTHENTICATION
1218   sqlite3_free(db->auth.zAuthUser);
1219   sqlite3_free(db->auth.zAuthPW);
1220 #endif
1221 
1222   db->magic = SQLITE_MAGIC_ERROR;
1223 
1224   /* The temp-database schema is allocated differently from the other schema
1225   ** objects (using sqliteMalloc() directly, instead of sqlite3BtreeSchema()).
1226   ** So it needs to be freed here. Todo: Why not roll the temp schema into
1227   ** the same sqliteMalloc() as the one that allocates the database
1228   ** structure?
1229   */
1230   sqlite3DbFree(db, db->aDb[1].pSchema);
1231   sqlite3_mutex_leave(db->mutex);
1232   db->magic = SQLITE_MAGIC_CLOSED;
1233   sqlite3_mutex_free(db->mutex);
1234   assert( sqlite3LookasideUsed(db,0)==0 );
1235   if( db->lookaside.bMalloced ){
1236     sqlite3_free(db->lookaside.pStart);
1237   }
1238   sqlite3_free(db);
1239 }
1240 
1241 /*
1242 ** Rollback all database files.  If tripCode is not SQLITE_OK, then
1243 ** any write cursors are invalidated ("tripped" - as in "tripping a circuit
1244 ** breaker") and made to return tripCode if there are any further
1245 ** attempts to use that cursor.  Read cursors remain open and valid
1246 ** but are "saved" in case the table pages are moved around.
1247 */
1248 void sqlite3RollbackAll(sqlite3 *db, int tripCode){
1249   int i;
1250   int inTrans = 0;
1251   int schemaChange;
1252   assert( sqlite3_mutex_held(db->mutex) );
1253   sqlite3BeginBenignMalloc();
1254 
1255   /* Obtain all b-tree mutexes before making any calls to BtreeRollback().
1256   ** This is important in case the transaction being rolled back has
1257   ** modified the database schema. If the b-tree mutexes are not taken
1258   ** here, then another shared-cache connection might sneak in between
1259   ** the database rollback and schema reset, which can cause false
1260   ** corruption reports in some cases.  */
1261   sqlite3BtreeEnterAll(db);
1262   schemaChange = (db->mDbFlags & DBFLAG_SchemaChange)!=0 && db->init.busy==0;
1263 
1264   for(i=0; i<db->nDb; i++){
1265     Btree *p = db->aDb[i].pBt;
1266     if( p ){
1267       if( sqlite3BtreeIsInTrans(p) ){
1268         inTrans = 1;
1269       }
1270       sqlite3BtreeRollback(p, tripCode, !schemaChange);
1271     }
1272   }
1273   sqlite3VtabRollback(db);
1274   sqlite3EndBenignMalloc();
1275 
1276   if( (db->mDbFlags&DBFLAG_SchemaChange)!=0 && db->init.busy==0 ){
1277     sqlite3ExpirePreparedStatements(db);
1278     sqlite3ResetAllSchemasOfConnection(db);
1279   }
1280   sqlite3BtreeLeaveAll(db);
1281 
1282   /* Any deferred constraint violations have now been resolved. */
1283   db->nDeferredCons = 0;
1284   db->nDeferredImmCons = 0;
1285   db->flags &= ~SQLITE_DeferFKs;
1286 
1287   /* If one has been configured, invoke the rollback-hook callback */
1288   if( db->xRollbackCallback && (inTrans || !db->autoCommit) ){
1289     db->xRollbackCallback(db->pRollbackArg);
1290   }
1291 }
1292 
1293 /*
1294 ** Return a static string containing the name corresponding to the error code
1295 ** specified in the argument.
1296 */
1297 #if defined(SQLITE_NEED_ERR_NAME)
1298 const char *sqlite3ErrName(int rc){
1299   const char *zName = 0;
1300   int i, origRc = rc;
1301   for(i=0; i<2 && zName==0; i++, rc &= 0xff){
1302     switch( rc ){
1303       case SQLITE_OK:                 zName = "SQLITE_OK";                break;
1304       case SQLITE_ERROR:              zName = "SQLITE_ERROR";             break;
1305       case SQLITE_INTERNAL:           zName = "SQLITE_INTERNAL";          break;
1306       case SQLITE_PERM:               zName = "SQLITE_PERM";              break;
1307       case SQLITE_ABORT:              zName = "SQLITE_ABORT";             break;
1308       case SQLITE_ABORT_ROLLBACK:     zName = "SQLITE_ABORT_ROLLBACK";    break;
1309       case SQLITE_BUSY:               zName = "SQLITE_BUSY";              break;
1310       case SQLITE_BUSY_RECOVERY:      zName = "SQLITE_BUSY_RECOVERY";     break;
1311       case SQLITE_BUSY_SNAPSHOT:      zName = "SQLITE_BUSY_SNAPSHOT";     break;
1312       case SQLITE_LOCKED:             zName = "SQLITE_LOCKED";            break;
1313       case SQLITE_LOCKED_SHAREDCACHE: zName = "SQLITE_LOCKED_SHAREDCACHE";break;
1314       case SQLITE_NOMEM:              zName = "SQLITE_NOMEM";             break;
1315       case SQLITE_READONLY:           zName = "SQLITE_READONLY";          break;
1316       case SQLITE_READONLY_RECOVERY:  zName = "SQLITE_READONLY_RECOVERY"; break;
1317       case SQLITE_READONLY_CANTINIT:  zName = "SQLITE_READONLY_CANTINIT"; break;
1318       case SQLITE_READONLY_ROLLBACK:  zName = "SQLITE_READONLY_ROLLBACK"; break;
1319       case SQLITE_READONLY_DBMOVED:   zName = "SQLITE_READONLY_DBMOVED";  break;
1320       case SQLITE_INTERRUPT:          zName = "SQLITE_INTERRUPT";         break;
1321       case SQLITE_IOERR:              zName = "SQLITE_IOERR";             break;
1322       case SQLITE_IOERR_READ:         zName = "SQLITE_IOERR_READ";        break;
1323       case SQLITE_IOERR_SHORT_READ:   zName = "SQLITE_IOERR_SHORT_READ";  break;
1324       case SQLITE_IOERR_WRITE:        zName = "SQLITE_IOERR_WRITE";       break;
1325       case SQLITE_IOERR_FSYNC:        zName = "SQLITE_IOERR_FSYNC";       break;
1326       case SQLITE_IOERR_DIR_FSYNC:    zName = "SQLITE_IOERR_DIR_FSYNC";   break;
1327       case SQLITE_IOERR_TRUNCATE:     zName = "SQLITE_IOERR_TRUNCATE";    break;
1328       case SQLITE_IOERR_FSTAT:        zName = "SQLITE_IOERR_FSTAT";       break;
1329       case SQLITE_IOERR_UNLOCK:       zName = "SQLITE_IOERR_UNLOCK";      break;
1330       case SQLITE_IOERR_RDLOCK:       zName = "SQLITE_IOERR_RDLOCK";      break;
1331       case SQLITE_IOERR_DELETE:       zName = "SQLITE_IOERR_DELETE";      break;
1332       case SQLITE_IOERR_NOMEM:        zName = "SQLITE_IOERR_NOMEM";       break;
1333       case SQLITE_IOERR_ACCESS:       zName = "SQLITE_IOERR_ACCESS";      break;
1334       case SQLITE_IOERR_CHECKRESERVEDLOCK:
1335                                 zName = "SQLITE_IOERR_CHECKRESERVEDLOCK"; break;
1336       case SQLITE_IOERR_LOCK:         zName = "SQLITE_IOERR_LOCK";        break;
1337       case SQLITE_IOERR_CLOSE:        zName = "SQLITE_IOERR_CLOSE";       break;
1338       case SQLITE_IOERR_DIR_CLOSE:    zName = "SQLITE_IOERR_DIR_CLOSE";   break;
1339       case SQLITE_IOERR_SHMOPEN:      zName = "SQLITE_IOERR_SHMOPEN";     break;
1340       case SQLITE_IOERR_SHMSIZE:      zName = "SQLITE_IOERR_SHMSIZE";     break;
1341       case SQLITE_IOERR_SHMLOCK:      zName = "SQLITE_IOERR_SHMLOCK";     break;
1342       case SQLITE_IOERR_SHMMAP:       zName = "SQLITE_IOERR_SHMMAP";      break;
1343       case SQLITE_IOERR_SEEK:         zName = "SQLITE_IOERR_SEEK";        break;
1344       case SQLITE_IOERR_DELETE_NOENT: zName = "SQLITE_IOERR_DELETE_NOENT";break;
1345       case SQLITE_IOERR_MMAP:         zName = "SQLITE_IOERR_MMAP";        break;
1346       case SQLITE_IOERR_GETTEMPPATH:  zName = "SQLITE_IOERR_GETTEMPPATH"; break;
1347       case SQLITE_IOERR_CONVPATH:     zName = "SQLITE_IOERR_CONVPATH";    break;
1348       case SQLITE_CORRUPT:            zName = "SQLITE_CORRUPT";           break;
1349       case SQLITE_CORRUPT_VTAB:       zName = "SQLITE_CORRUPT_VTAB";      break;
1350       case SQLITE_NOTFOUND:           zName = "SQLITE_NOTFOUND";          break;
1351       case SQLITE_FULL:               zName = "SQLITE_FULL";              break;
1352       case SQLITE_CANTOPEN:           zName = "SQLITE_CANTOPEN";          break;
1353       case SQLITE_CANTOPEN_NOTEMPDIR: zName = "SQLITE_CANTOPEN_NOTEMPDIR";break;
1354       case SQLITE_CANTOPEN_ISDIR:     zName = "SQLITE_CANTOPEN_ISDIR";    break;
1355       case SQLITE_CANTOPEN_FULLPATH:  zName = "SQLITE_CANTOPEN_FULLPATH"; break;
1356       case SQLITE_CANTOPEN_CONVPATH:  zName = "SQLITE_CANTOPEN_CONVPATH"; break;
1357       case SQLITE_PROTOCOL:           zName = "SQLITE_PROTOCOL";          break;
1358       case SQLITE_EMPTY:              zName = "SQLITE_EMPTY";             break;
1359       case SQLITE_SCHEMA:             zName = "SQLITE_SCHEMA";            break;
1360       case SQLITE_TOOBIG:             zName = "SQLITE_TOOBIG";            break;
1361       case SQLITE_CONSTRAINT:         zName = "SQLITE_CONSTRAINT";        break;
1362       case SQLITE_CONSTRAINT_UNIQUE:  zName = "SQLITE_CONSTRAINT_UNIQUE"; break;
1363       case SQLITE_CONSTRAINT_TRIGGER: zName = "SQLITE_CONSTRAINT_TRIGGER";break;
1364       case SQLITE_CONSTRAINT_FOREIGNKEY:
1365                                 zName = "SQLITE_CONSTRAINT_FOREIGNKEY";   break;
1366       case SQLITE_CONSTRAINT_CHECK:   zName = "SQLITE_CONSTRAINT_CHECK";  break;
1367       case SQLITE_CONSTRAINT_PRIMARYKEY:
1368                                 zName = "SQLITE_CONSTRAINT_PRIMARYKEY";   break;
1369       case SQLITE_CONSTRAINT_NOTNULL: zName = "SQLITE_CONSTRAINT_NOTNULL";break;
1370       case SQLITE_CONSTRAINT_COMMITHOOK:
1371                                 zName = "SQLITE_CONSTRAINT_COMMITHOOK";   break;
1372       case SQLITE_CONSTRAINT_VTAB:    zName = "SQLITE_CONSTRAINT_VTAB";   break;
1373       case SQLITE_CONSTRAINT_FUNCTION:
1374                                 zName = "SQLITE_CONSTRAINT_FUNCTION";     break;
1375       case SQLITE_CONSTRAINT_ROWID:   zName = "SQLITE_CONSTRAINT_ROWID";  break;
1376       case SQLITE_MISMATCH:           zName = "SQLITE_MISMATCH";          break;
1377       case SQLITE_MISUSE:             zName = "SQLITE_MISUSE";            break;
1378       case SQLITE_NOLFS:              zName = "SQLITE_NOLFS";             break;
1379       case SQLITE_AUTH:               zName = "SQLITE_AUTH";              break;
1380       case SQLITE_FORMAT:             zName = "SQLITE_FORMAT";            break;
1381       case SQLITE_RANGE:              zName = "SQLITE_RANGE";             break;
1382       case SQLITE_NOTADB:             zName = "SQLITE_NOTADB";            break;
1383       case SQLITE_ROW:                zName = "SQLITE_ROW";               break;
1384       case SQLITE_NOTICE:             zName = "SQLITE_NOTICE";            break;
1385       case SQLITE_NOTICE_RECOVER_WAL: zName = "SQLITE_NOTICE_RECOVER_WAL";break;
1386       case SQLITE_NOTICE_RECOVER_ROLLBACK:
1387                                 zName = "SQLITE_NOTICE_RECOVER_ROLLBACK"; break;
1388       case SQLITE_WARNING:            zName = "SQLITE_WARNING";           break;
1389       case SQLITE_WARNING_AUTOINDEX:  zName = "SQLITE_WARNING_AUTOINDEX"; break;
1390       case SQLITE_DONE:               zName = "SQLITE_DONE";              break;
1391     }
1392   }
1393   if( zName==0 ){
1394     static char zBuf[50];
1395     sqlite3_snprintf(sizeof(zBuf), zBuf, "SQLITE_UNKNOWN(%d)", origRc);
1396     zName = zBuf;
1397   }
1398   return zName;
1399 }
1400 #endif
1401 
1402 /*
1403 ** Return a static string that describes the kind of error specified in the
1404 ** argument.
1405 */
1406 const char *sqlite3ErrStr(int rc){
1407   static const char* const aMsg[] = {
1408     /* SQLITE_OK          */ "not an error",
1409     /* SQLITE_ERROR       */ "SQL logic error",
1410     /* SQLITE_INTERNAL    */ 0,
1411     /* SQLITE_PERM        */ "access permission denied",
1412     /* SQLITE_ABORT       */ "query aborted",
1413     /* SQLITE_BUSY        */ "database is locked",
1414     /* SQLITE_LOCKED      */ "database table is locked",
1415     /* SQLITE_NOMEM       */ "out of memory",
1416     /* SQLITE_READONLY    */ "attempt to write a readonly database",
1417     /* SQLITE_INTERRUPT   */ "interrupted",
1418     /* SQLITE_IOERR       */ "disk I/O error",
1419     /* SQLITE_CORRUPT     */ "database disk image is malformed",
1420     /* SQLITE_NOTFOUND    */ "unknown operation",
1421     /* SQLITE_FULL        */ "database or disk is full",
1422     /* SQLITE_CANTOPEN    */ "unable to open database file",
1423     /* SQLITE_PROTOCOL    */ "locking protocol",
1424     /* SQLITE_EMPTY       */ 0,
1425     /* SQLITE_SCHEMA      */ "database schema has changed",
1426     /* SQLITE_TOOBIG      */ "string or blob too big",
1427     /* SQLITE_CONSTRAINT  */ "constraint failed",
1428     /* SQLITE_MISMATCH    */ "datatype mismatch",
1429     /* SQLITE_MISUSE      */ "bad parameter or other API misuse",
1430 #ifdef SQLITE_DISABLE_LFS
1431     /* SQLITE_NOLFS       */ "large file support is disabled",
1432 #else
1433     /* SQLITE_NOLFS       */ 0,
1434 #endif
1435     /* SQLITE_AUTH        */ "authorization denied",
1436     /* SQLITE_FORMAT      */ 0,
1437     /* SQLITE_RANGE       */ "column index out of range",
1438     /* SQLITE_NOTADB      */ "file is not a database",
1439   };
1440   const char *zErr = "unknown error";
1441   switch( rc ){
1442     case SQLITE_ABORT_ROLLBACK: {
1443       zErr = "abort due to ROLLBACK";
1444       break;
1445     }
1446     default: {
1447       rc &= 0xff;
1448       if( ALWAYS(rc>=0) && rc<ArraySize(aMsg) && aMsg[rc]!=0 ){
1449         zErr = aMsg[rc];
1450       }
1451       break;
1452     }
1453   }
1454   return zErr;
1455 }
1456 
1457 /*
1458 ** This routine implements a busy callback that sleeps and tries
1459 ** again until a timeout value is reached.  The timeout value is
1460 ** an integer number of milliseconds passed in as the first
1461 ** argument.
1462 */
1463 static int sqliteDefaultBusyCallback(
1464  void *ptr,               /* Database connection */
1465  int count                /* Number of times table has been busy */
1466 ){
1467 #if SQLITE_OS_WIN || HAVE_USLEEP
1468   static const u8 delays[] =
1469      { 1, 2, 5, 10, 15, 20, 25, 25,  25,  50,  50, 100 };
1470   static const u8 totals[] =
1471      { 0, 1, 3,  8, 18, 33, 53, 78, 103, 128, 178, 228 };
1472 # define NDELAY ArraySize(delays)
1473   sqlite3 *db = (sqlite3 *)ptr;
1474   int timeout = db->busyTimeout;
1475   int delay, prior;
1476 
1477   assert( count>=0 );
1478   if( count < NDELAY ){
1479     delay = delays[count];
1480     prior = totals[count];
1481   }else{
1482     delay = delays[NDELAY-1];
1483     prior = totals[NDELAY-1] + delay*(count-(NDELAY-1));
1484   }
1485   if( prior + delay > timeout ){
1486     delay = timeout - prior;
1487     if( delay<=0 ) return 0;
1488   }
1489   sqlite3OsSleep(db->pVfs, delay*1000);
1490   return 1;
1491 #else
1492   sqlite3 *db = (sqlite3 *)ptr;
1493   int timeout = ((sqlite3 *)ptr)->busyTimeout;
1494   if( (count+1)*1000 > timeout ){
1495     return 0;
1496   }
1497   sqlite3OsSleep(db->pVfs, 1000000);
1498   return 1;
1499 #endif
1500 }
1501 
1502 /*
1503 ** Invoke the given busy handler.
1504 **
1505 ** This routine is called when an operation failed with a lock.
1506 ** If this routine returns non-zero, the lock is retried.  If it
1507 ** returns 0, the operation aborts with an SQLITE_BUSY error.
1508 */
1509 int sqlite3InvokeBusyHandler(BusyHandler *p){
1510   int rc;
1511   if( NEVER(p==0) || p->xFunc==0 || p->nBusy<0 ) return 0;
1512   rc = p->xFunc(p->pArg, p->nBusy);
1513   if( rc==0 ){
1514     p->nBusy = -1;
1515   }else{
1516     p->nBusy++;
1517   }
1518   return rc;
1519 }
1520 
1521 /*
1522 ** This routine sets the busy callback for an Sqlite database to the
1523 ** given callback function with the given argument.
1524 */
1525 int sqlite3_busy_handler(
1526   sqlite3 *db,
1527   int (*xBusy)(void*,int),
1528   void *pArg
1529 ){
1530 #ifdef SQLITE_ENABLE_API_ARMOR
1531   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
1532 #endif
1533   sqlite3_mutex_enter(db->mutex);
1534   db->busyHandler.xFunc = xBusy;
1535   db->busyHandler.pArg = pArg;
1536   db->busyHandler.nBusy = 0;
1537   db->busyTimeout = 0;
1538   sqlite3_mutex_leave(db->mutex);
1539   return SQLITE_OK;
1540 }
1541 
1542 #ifndef SQLITE_OMIT_PROGRESS_CALLBACK
1543 /*
1544 ** This routine sets the progress callback for an Sqlite database to the
1545 ** given callback function with the given argument. The progress callback will
1546 ** be invoked every nOps opcodes.
1547 */
1548 void sqlite3_progress_handler(
1549   sqlite3 *db,
1550   int nOps,
1551   int (*xProgress)(void*),
1552   void *pArg
1553 ){
1554 #ifdef SQLITE_ENABLE_API_ARMOR
1555   if( !sqlite3SafetyCheckOk(db) ){
1556     (void)SQLITE_MISUSE_BKPT;
1557     return;
1558   }
1559 #endif
1560   sqlite3_mutex_enter(db->mutex);
1561   if( nOps>0 ){
1562     db->xProgress = xProgress;
1563     db->nProgressOps = (unsigned)nOps;
1564     db->pProgressArg = pArg;
1565   }else{
1566     db->xProgress = 0;
1567     db->nProgressOps = 0;
1568     db->pProgressArg = 0;
1569   }
1570   sqlite3_mutex_leave(db->mutex);
1571 }
1572 #endif
1573 
1574 
1575 /*
1576 ** This routine installs a default busy handler that waits for the
1577 ** specified number of milliseconds before returning 0.
1578 */
1579 int sqlite3_busy_timeout(sqlite3 *db, int ms){
1580 #ifdef SQLITE_ENABLE_API_ARMOR
1581   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
1582 #endif
1583   if( ms>0 ){
1584     sqlite3_busy_handler(db, sqliteDefaultBusyCallback, (void*)db);
1585     db->busyTimeout = ms;
1586   }else{
1587     sqlite3_busy_handler(db, 0, 0);
1588   }
1589   return SQLITE_OK;
1590 }
1591 
1592 /*
1593 ** Cause any pending operation to stop at its earliest opportunity.
1594 */
1595 void sqlite3_interrupt(sqlite3 *db){
1596 #ifdef SQLITE_ENABLE_API_ARMOR
1597   if( !sqlite3SafetyCheckOk(db) && (db==0 || db->magic!=SQLITE_MAGIC_ZOMBIE) ){
1598     (void)SQLITE_MISUSE_BKPT;
1599     return;
1600   }
1601 #endif
1602   db->u1.isInterrupted = 1;
1603 }
1604 
1605 
1606 /*
1607 ** This function is exactly the same as sqlite3_create_function(), except
1608 ** that it is designed to be called by internal code. The difference is
1609 ** that if a malloc() fails in sqlite3_create_function(), an error code
1610 ** is returned and the mallocFailed flag cleared.
1611 */
1612 int sqlite3CreateFunc(
1613   sqlite3 *db,
1614   const char *zFunctionName,
1615   int nArg,
1616   int enc,
1617   void *pUserData,
1618   void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
1619   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
1620   void (*xFinal)(sqlite3_context*),
1621   FuncDestructor *pDestructor
1622 ){
1623   FuncDef *p;
1624   int nName;
1625   int extraFlags;
1626 
1627   assert( sqlite3_mutex_held(db->mutex) );
1628   if( zFunctionName==0 ||
1629       (xSFunc && (xFinal || xStep)) ||
1630       (!xSFunc && (xFinal && !xStep)) ||
1631       (!xSFunc && (!xFinal && xStep)) ||
1632       (nArg<-1 || nArg>SQLITE_MAX_FUNCTION_ARG) ||
1633       (255<(nName = sqlite3Strlen30( zFunctionName))) ){
1634     return SQLITE_MISUSE_BKPT;
1635   }
1636 
1637   assert( SQLITE_FUNC_CONSTANT==SQLITE_DETERMINISTIC );
1638   extraFlags = enc &  SQLITE_DETERMINISTIC;
1639   enc &= (SQLITE_FUNC_ENCMASK|SQLITE_ANY);
1640 
1641 #ifndef SQLITE_OMIT_UTF16
1642   /* If SQLITE_UTF16 is specified as the encoding type, transform this
1643   ** to one of SQLITE_UTF16LE or SQLITE_UTF16BE using the
1644   ** SQLITE_UTF16NATIVE macro. SQLITE_UTF16 is not used internally.
1645   **
1646   ** If SQLITE_ANY is specified, add three versions of the function
1647   ** to the hash table.
1648   */
1649   if( enc==SQLITE_UTF16 ){
1650     enc = SQLITE_UTF16NATIVE;
1651   }else if( enc==SQLITE_ANY ){
1652     int rc;
1653     rc = sqlite3CreateFunc(db, zFunctionName, nArg, SQLITE_UTF8|extraFlags,
1654          pUserData, xSFunc, xStep, xFinal, pDestructor);
1655     if( rc==SQLITE_OK ){
1656       rc = sqlite3CreateFunc(db, zFunctionName, nArg, SQLITE_UTF16LE|extraFlags,
1657           pUserData, xSFunc, xStep, xFinal, pDestructor);
1658     }
1659     if( rc!=SQLITE_OK ){
1660       return rc;
1661     }
1662     enc = SQLITE_UTF16BE;
1663   }
1664 #else
1665   enc = SQLITE_UTF8;
1666 #endif
1667 
1668   /* Check if an existing function is being overridden or deleted. If so,
1669   ** and there are active VMs, then return SQLITE_BUSY. If a function
1670   ** is being overridden/deleted but there are no active VMs, allow the
1671   ** operation to continue but invalidate all precompiled statements.
1672   */
1673   p = sqlite3FindFunction(db, zFunctionName, nArg, (u8)enc, 0);
1674   if( p && (p->funcFlags & SQLITE_FUNC_ENCMASK)==enc && p->nArg==nArg ){
1675     if( db->nVdbeActive ){
1676       sqlite3ErrorWithMsg(db, SQLITE_BUSY,
1677         "unable to delete/modify user-function due to active statements");
1678       assert( !db->mallocFailed );
1679       return SQLITE_BUSY;
1680     }else{
1681       sqlite3ExpirePreparedStatements(db);
1682     }
1683   }
1684 
1685   p = sqlite3FindFunction(db, zFunctionName, nArg, (u8)enc, 1);
1686   assert(p || db->mallocFailed);
1687   if( !p ){
1688     return SQLITE_NOMEM_BKPT;
1689   }
1690 
1691   /* If an older version of the function with a configured destructor is
1692   ** being replaced invoke the destructor function here. */
1693   functionDestroy(db, p);
1694 
1695   if( pDestructor ){
1696     pDestructor->nRef++;
1697   }
1698   p->u.pDestructor = pDestructor;
1699   p->funcFlags = (p->funcFlags & SQLITE_FUNC_ENCMASK) | extraFlags;
1700   testcase( p->funcFlags & SQLITE_DETERMINISTIC );
1701   p->xSFunc = xSFunc ? xSFunc : xStep;
1702   p->xFinalize = xFinal;
1703   p->pUserData = pUserData;
1704   p->nArg = (u16)nArg;
1705   return SQLITE_OK;
1706 }
1707 
1708 /*
1709 ** Create new user functions.
1710 */
1711 int sqlite3_create_function(
1712   sqlite3 *db,
1713   const char *zFunc,
1714   int nArg,
1715   int enc,
1716   void *p,
1717   void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
1718   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
1719   void (*xFinal)(sqlite3_context*)
1720 ){
1721   return sqlite3_create_function_v2(db, zFunc, nArg, enc, p, xSFunc, xStep,
1722                                     xFinal, 0);
1723 }
1724 
1725 int sqlite3_create_function_v2(
1726   sqlite3 *db,
1727   const char *zFunc,
1728   int nArg,
1729   int enc,
1730   void *p,
1731   void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
1732   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
1733   void (*xFinal)(sqlite3_context*),
1734   void (*xDestroy)(void *)
1735 ){
1736   int rc = SQLITE_ERROR;
1737   FuncDestructor *pArg = 0;
1738 
1739 #ifdef SQLITE_ENABLE_API_ARMOR
1740   if( !sqlite3SafetyCheckOk(db) ){
1741     return SQLITE_MISUSE_BKPT;
1742   }
1743 #endif
1744   sqlite3_mutex_enter(db->mutex);
1745   if( xDestroy ){
1746     pArg = (FuncDestructor *)sqlite3DbMallocZero(db, sizeof(FuncDestructor));
1747     if( !pArg ){
1748       xDestroy(p);
1749       goto out;
1750     }
1751     pArg->xDestroy = xDestroy;
1752     pArg->pUserData = p;
1753   }
1754   rc = sqlite3CreateFunc(db, zFunc, nArg, enc, p, xSFunc, xStep, xFinal, pArg);
1755   if( pArg && pArg->nRef==0 ){
1756     assert( rc!=SQLITE_OK );
1757     xDestroy(p);
1758     sqlite3DbFree(db, pArg);
1759   }
1760 
1761  out:
1762   rc = sqlite3ApiExit(db, rc);
1763   sqlite3_mutex_leave(db->mutex);
1764   return rc;
1765 }
1766 
1767 #ifndef SQLITE_OMIT_UTF16
1768 int sqlite3_create_function16(
1769   sqlite3 *db,
1770   const void *zFunctionName,
1771   int nArg,
1772   int eTextRep,
1773   void *p,
1774   void (*xSFunc)(sqlite3_context*,int,sqlite3_value**),
1775   void (*xStep)(sqlite3_context*,int,sqlite3_value**),
1776   void (*xFinal)(sqlite3_context*)
1777 ){
1778   int rc;
1779   char *zFunc8;
1780 
1781 #ifdef SQLITE_ENABLE_API_ARMOR
1782   if( !sqlite3SafetyCheckOk(db) || zFunctionName==0 ) return SQLITE_MISUSE_BKPT;
1783 #endif
1784   sqlite3_mutex_enter(db->mutex);
1785   assert( !db->mallocFailed );
1786   zFunc8 = sqlite3Utf16to8(db, zFunctionName, -1, SQLITE_UTF16NATIVE);
1787   rc = sqlite3CreateFunc(db, zFunc8, nArg, eTextRep, p, xSFunc,xStep,xFinal,0);
1788   sqlite3DbFree(db, zFunc8);
1789   rc = sqlite3ApiExit(db, rc);
1790   sqlite3_mutex_leave(db->mutex);
1791   return rc;
1792 }
1793 #endif
1794 
1795 
1796 /*
1797 ** Declare that a function has been overloaded by a virtual table.
1798 **
1799 ** If the function already exists as a regular global function, then
1800 ** this routine is a no-op.  If the function does not exist, then create
1801 ** a new one that always throws a run-time error.
1802 **
1803 ** When virtual tables intend to provide an overloaded function, they
1804 ** should call this routine to make sure the global function exists.
1805 ** A global function must exist in order for name resolution to work
1806 ** properly.
1807 */
1808 int sqlite3_overload_function(
1809   sqlite3 *db,
1810   const char *zName,
1811   int nArg
1812 ){
1813   int rc = SQLITE_OK;
1814 
1815 #ifdef SQLITE_ENABLE_API_ARMOR
1816   if( !sqlite3SafetyCheckOk(db) || zName==0 || nArg<-2 ){
1817     return SQLITE_MISUSE_BKPT;
1818   }
1819 #endif
1820   sqlite3_mutex_enter(db->mutex);
1821   if( sqlite3FindFunction(db, zName, nArg, SQLITE_UTF8, 0)==0 ){
1822     rc = sqlite3CreateFunc(db, zName, nArg, SQLITE_UTF8,
1823                            0, sqlite3InvalidFunction, 0, 0, 0);
1824   }
1825   rc = sqlite3ApiExit(db, rc);
1826   sqlite3_mutex_leave(db->mutex);
1827   return rc;
1828 }
1829 
1830 #ifndef SQLITE_OMIT_TRACE
1831 /*
1832 ** Register a trace function.  The pArg from the previously registered trace
1833 ** is returned.
1834 **
1835 ** A NULL trace function means that no tracing is executes.  A non-NULL
1836 ** trace is a pointer to a function that is invoked at the start of each
1837 ** SQL statement.
1838 */
1839 #ifndef SQLITE_OMIT_DEPRECATED
1840 void *sqlite3_trace(sqlite3 *db, void(*xTrace)(void*,const char*), void *pArg){
1841   void *pOld;
1842 
1843 #ifdef SQLITE_ENABLE_API_ARMOR
1844   if( !sqlite3SafetyCheckOk(db) ){
1845     (void)SQLITE_MISUSE_BKPT;
1846     return 0;
1847   }
1848 #endif
1849   sqlite3_mutex_enter(db->mutex);
1850   pOld = db->pTraceArg;
1851   db->mTrace = xTrace ? SQLITE_TRACE_LEGACY : 0;
1852   db->xTrace = (int(*)(u32,void*,void*,void*))xTrace;
1853   db->pTraceArg = pArg;
1854   sqlite3_mutex_leave(db->mutex);
1855   return pOld;
1856 }
1857 #endif /* SQLITE_OMIT_DEPRECATED */
1858 
1859 /* Register a trace callback using the version-2 interface.
1860 */
1861 int sqlite3_trace_v2(
1862   sqlite3 *db,                               /* Trace this connection */
1863   unsigned mTrace,                           /* Mask of events to be traced */
1864   int(*xTrace)(unsigned,void*,void*,void*),  /* Callback to invoke */
1865   void *pArg                                 /* Context */
1866 ){
1867 #ifdef SQLITE_ENABLE_API_ARMOR
1868   if( !sqlite3SafetyCheckOk(db) ){
1869     return SQLITE_MISUSE_BKPT;
1870   }
1871 #endif
1872   sqlite3_mutex_enter(db->mutex);
1873   if( mTrace==0 ) xTrace = 0;
1874   if( xTrace==0 ) mTrace = 0;
1875   db->mTrace = mTrace;
1876   db->xTrace = xTrace;
1877   db->pTraceArg = pArg;
1878   sqlite3_mutex_leave(db->mutex);
1879   return SQLITE_OK;
1880 }
1881 
1882 #ifndef SQLITE_OMIT_DEPRECATED
1883 /*
1884 ** Register a profile function.  The pArg from the previously registered
1885 ** profile function is returned.
1886 **
1887 ** A NULL profile function means that no profiling is executes.  A non-NULL
1888 ** profile is a pointer to a function that is invoked at the conclusion of
1889 ** each SQL statement that is run.
1890 */
1891 void *sqlite3_profile(
1892   sqlite3 *db,
1893   void (*xProfile)(void*,const char*,sqlite_uint64),
1894   void *pArg
1895 ){
1896   void *pOld;
1897 
1898 #ifdef SQLITE_ENABLE_API_ARMOR
1899   if( !sqlite3SafetyCheckOk(db) ){
1900     (void)SQLITE_MISUSE_BKPT;
1901     return 0;
1902   }
1903 #endif
1904   sqlite3_mutex_enter(db->mutex);
1905   pOld = db->pProfileArg;
1906   db->xProfile = xProfile;
1907   db->pProfileArg = pArg;
1908   sqlite3_mutex_leave(db->mutex);
1909   return pOld;
1910 }
1911 #endif /* SQLITE_OMIT_DEPRECATED */
1912 #endif /* SQLITE_OMIT_TRACE */
1913 
1914 /*
1915 ** Register a function to be invoked when a transaction commits.
1916 ** If the invoked function returns non-zero, then the commit becomes a
1917 ** rollback.
1918 */
1919 void *sqlite3_commit_hook(
1920   sqlite3 *db,              /* Attach the hook to this database */
1921   int (*xCallback)(void*),  /* Function to invoke on each commit */
1922   void *pArg                /* Argument to the function */
1923 ){
1924   void *pOld;
1925 
1926 #ifdef SQLITE_ENABLE_API_ARMOR
1927   if( !sqlite3SafetyCheckOk(db) ){
1928     (void)SQLITE_MISUSE_BKPT;
1929     return 0;
1930   }
1931 #endif
1932   sqlite3_mutex_enter(db->mutex);
1933   pOld = db->pCommitArg;
1934   db->xCommitCallback = xCallback;
1935   db->pCommitArg = pArg;
1936   sqlite3_mutex_leave(db->mutex);
1937   return pOld;
1938 }
1939 
1940 /*
1941 ** Register a callback to be invoked each time a row is updated,
1942 ** inserted or deleted using this database connection.
1943 */
1944 void *sqlite3_update_hook(
1945   sqlite3 *db,              /* Attach the hook to this database */
1946   void (*xCallback)(void*,int,char const *,char const *,sqlite_int64),
1947   void *pArg                /* Argument to the function */
1948 ){
1949   void *pRet;
1950 
1951 #ifdef SQLITE_ENABLE_API_ARMOR
1952   if( !sqlite3SafetyCheckOk(db) ){
1953     (void)SQLITE_MISUSE_BKPT;
1954     return 0;
1955   }
1956 #endif
1957   sqlite3_mutex_enter(db->mutex);
1958   pRet = db->pUpdateArg;
1959   db->xUpdateCallback = xCallback;
1960   db->pUpdateArg = pArg;
1961   sqlite3_mutex_leave(db->mutex);
1962   return pRet;
1963 }
1964 
1965 /*
1966 ** Register a callback to be invoked each time a transaction is rolled
1967 ** back by this database connection.
1968 */
1969 void *sqlite3_rollback_hook(
1970   sqlite3 *db,              /* Attach the hook to this database */
1971   void (*xCallback)(void*), /* Callback function */
1972   void *pArg                /* Argument to the function */
1973 ){
1974   void *pRet;
1975 
1976 #ifdef SQLITE_ENABLE_API_ARMOR
1977   if( !sqlite3SafetyCheckOk(db) ){
1978     (void)SQLITE_MISUSE_BKPT;
1979     return 0;
1980   }
1981 #endif
1982   sqlite3_mutex_enter(db->mutex);
1983   pRet = db->pRollbackArg;
1984   db->xRollbackCallback = xCallback;
1985   db->pRollbackArg = pArg;
1986   sqlite3_mutex_leave(db->mutex);
1987   return pRet;
1988 }
1989 
1990 #ifdef SQLITE_ENABLE_PREUPDATE_HOOK
1991 /*
1992 ** Register a callback to be invoked each time a row is updated,
1993 ** inserted or deleted using this database connection.
1994 */
1995 void *sqlite3_preupdate_hook(
1996   sqlite3 *db,              /* Attach the hook to this database */
1997   void(*xCallback)(         /* Callback function */
1998     void*,sqlite3*,int,char const*,char const*,sqlite3_int64,sqlite3_int64),
1999   void *pArg                /* First callback argument */
2000 ){
2001   void *pRet;
2002   sqlite3_mutex_enter(db->mutex);
2003   pRet = db->pPreUpdateArg;
2004   db->xPreUpdateCallback = xCallback;
2005   db->pPreUpdateArg = pArg;
2006   sqlite3_mutex_leave(db->mutex);
2007   return pRet;
2008 }
2009 #endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
2010 
2011 #ifndef SQLITE_OMIT_WAL
2012 /*
2013 ** The sqlite3_wal_hook() callback registered by sqlite3_wal_autocheckpoint().
2014 ** Invoke sqlite3_wal_checkpoint if the number of frames in the log file
2015 ** is greater than sqlite3.pWalArg cast to an integer (the value configured by
2016 ** wal_autocheckpoint()).
2017 */
2018 int sqlite3WalDefaultHook(
2019   void *pClientData,     /* Argument */
2020   sqlite3 *db,           /* Connection */
2021   const char *zDb,       /* Database */
2022   int nFrame             /* Size of WAL */
2023 ){
2024   if( nFrame>=SQLITE_PTR_TO_INT(pClientData) ){
2025     sqlite3BeginBenignMalloc();
2026     sqlite3_wal_checkpoint(db, zDb);
2027     sqlite3EndBenignMalloc();
2028   }
2029   return SQLITE_OK;
2030 }
2031 #endif /* SQLITE_OMIT_WAL */
2032 
2033 /*
2034 ** Configure an sqlite3_wal_hook() callback to automatically checkpoint
2035 ** a database after committing a transaction if there are nFrame or
2036 ** more frames in the log file. Passing zero or a negative value as the
2037 ** nFrame parameter disables automatic checkpoints entirely.
2038 **
2039 ** The callback registered by this function replaces any existing callback
2040 ** registered using sqlite3_wal_hook(). Likewise, registering a callback
2041 ** using sqlite3_wal_hook() disables the automatic checkpoint mechanism
2042 ** configured by this function.
2043 */
2044 int sqlite3_wal_autocheckpoint(sqlite3 *db, int nFrame){
2045 #ifdef SQLITE_OMIT_WAL
2046   UNUSED_PARAMETER(db);
2047   UNUSED_PARAMETER(nFrame);
2048 #else
2049 #ifdef SQLITE_ENABLE_API_ARMOR
2050   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
2051 #endif
2052   if( nFrame>0 ){
2053     sqlite3_wal_hook(db, sqlite3WalDefaultHook, SQLITE_INT_TO_PTR(nFrame));
2054   }else{
2055     sqlite3_wal_hook(db, 0, 0);
2056   }
2057 #endif
2058   return SQLITE_OK;
2059 }
2060 
2061 /*
2062 ** Register a callback to be invoked each time a transaction is written
2063 ** into the write-ahead-log by this database connection.
2064 */
2065 void *sqlite3_wal_hook(
2066   sqlite3 *db,                    /* Attach the hook to this db handle */
2067   int(*xCallback)(void *, sqlite3*, const char*, int),
2068   void *pArg                      /* First argument passed to xCallback() */
2069 ){
2070 #ifndef SQLITE_OMIT_WAL
2071   void *pRet;
2072 #ifdef SQLITE_ENABLE_API_ARMOR
2073   if( !sqlite3SafetyCheckOk(db) ){
2074     (void)SQLITE_MISUSE_BKPT;
2075     return 0;
2076   }
2077 #endif
2078   sqlite3_mutex_enter(db->mutex);
2079   pRet = db->pWalArg;
2080   db->xWalCallback = xCallback;
2081   db->pWalArg = pArg;
2082   sqlite3_mutex_leave(db->mutex);
2083   return pRet;
2084 #else
2085   return 0;
2086 #endif
2087 }
2088 
2089 /*
2090 ** Checkpoint database zDb.
2091 */
2092 int sqlite3_wal_checkpoint_v2(
2093   sqlite3 *db,                    /* Database handle */
2094   const char *zDb,                /* Name of attached database (or NULL) */
2095   int eMode,                      /* SQLITE_CHECKPOINT_* value */
2096   int *pnLog,                     /* OUT: Size of WAL log in frames */
2097   int *pnCkpt                     /* OUT: Total number of frames checkpointed */
2098 ){
2099 #ifdef SQLITE_OMIT_WAL
2100   return SQLITE_OK;
2101 #else
2102   int rc;                         /* Return code */
2103   int iDb = SQLITE_MAX_ATTACHED;  /* sqlite3.aDb[] index of db to checkpoint */
2104 
2105 #ifdef SQLITE_ENABLE_API_ARMOR
2106   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
2107 #endif
2108 
2109   /* Initialize the output variables to -1 in case an error occurs. */
2110   if( pnLog ) *pnLog = -1;
2111   if( pnCkpt ) *pnCkpt = -1;
2112 
2113   assert( SQLITE_CHECKPOINT_PASSIVE==0 );
2114   assert( SQLITE_CHECKPOINT_FULL==1 );
2115   assert( SQLITE_CHECKPOINT_RESTART==2 );
2116   assert( SQLITE_CHECKPOINT_TRUNCATE==3 );
2117   if( eMode<SQLITE_CHECKPOINT_PASSIVE || eMode>SQLITE_CHECKPOINT_TRUNCATE ){
2118     /* EVIDENCE-OF: R-03996-12088 The M parameter must be a valid checkpoint
2119     ** mode: */
2120     return SQLITE_MISUSE;
2121   }
2122 
2123   sqlite3_mutex_enter(db->mutex);
2124   if( zDb && zDb[0] ){
2125     iDb = sqlite3FindDbName(db, zDb);
2126   }
2127   if( iDb<0 ){
2128     rc = SQLITE_ERROR;
2129     sqlite3ErrorWithMsg(db, SQLITE_ERROR, "unknown database: %s", zDb);
2130   }else{
2131     db->busyHandler.nBusy = 0;
2132     rc = sqlite3Checkpoint(db, iDb, eMode, pnLog, pnCkpt);
2133     sqlite3Error(db, rc);
2134   }
2135   rc = sqlite3ApiExit(db, rc);
2136 
2137   /* If there are no active statements, clear the interrupt flag at this
2138   ** point.  */
2139   if( db->nVdbeActive==0 ){
2140     db->u1.isInterrupted = 0;
2141   }
2142 
2143   sqlite3_mutex_leave(db->mutex);
2144   return rc;
2145 #endif
2146 }
2147 
2148 
2149 /*
2150 ** Checkpoint database zDb. If zDb is NULL, or if the buffer zDb points
2151 ** to contains a zero-length string, all attached databases are
2152 ** checkpointed.
2153 */
2154 int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb){
2155   /* EVIDENCE-OF: R-41613-20553 The sqlite3_wal_checkpoint(D,X) is equivalent to
2156   ** sqlite3_wal_checkpoint_v2(D,X,SQLITE_CHECKPOINT_PASSIVE,0,0). */
2157   return sqlite3_wal_checkpoint_v2(db,zDb,SQLITE_CHECKPOINT_PASSIVE,0,0);
2158 }
2159 
2160 #ifndef SQLITE_OMIT_WAL
2161 /*
2162 ** Run a checkpoint on database iDb. This is a no-op if database iDb is
2163 ** not currently open in WAL mode.
2164 **
2165 ** If a transaction is open on the database being checkpointed, this
2166 ** function returns SQLITE_LOCKED and a checkpoint is not attempted. If
2167 ** an error occurs while running the checkpoint, an SQLite error code is
2168 ** returned (i.e. SQLITE_IOERR). Otherwise, SQLITE_OK.
2169 **
2170 ** The mutex on database handle db should be held by the caller. The mutex
2171 ** associated with the specific b-tree being checkpointed is taken by
2172 ** this function while the checkpoint is running.
2173 **
2174 ** If iDb is passed SQLITE_MAX_ATTACHED, then all attached databases are
2175 ** checkpointed. If an error is encountered it is returned immediately -
2176 ** no attempt is made to checkpoint any remaining databases.
2177 **
2178 ** Parameter eMode is one of SQLITE_CHECKPOINT_PASSIVE, FULL, RESTART
2179 ** or TRUNCATE.
2180 */
2181 int sqlite3Checkpoint(sqlite3 *db, int iDb, int eMode, int *pnLog, int *pnCkpt){
2182   int rc = SQLITE_OK;             /* Return code */
2183   int i;                          /* Used to iterate through attached dbs */
2184   int bBusy = 0;                  /* True if SQLITE_BUSY has been encountered */
2185 
2186   assert( sqlite3_mutex_held(db->mutex) );
2187   assert( !pnLog || *pnLog==-1 );
2188   assert( !pnCkpt || *pnCkpt==-1 );
2189 
2190   for(i=0; i<db->nDb && rc==SQLITE_OK; i++){
2191     if( i==iDb || iDb==SQLITE_MAX_ATTACHED ){
2192       rc = sqlite3BtreeCheckpoint(db->aDb[i].pBt, eMode, pnLog, pnCkpt);
2193       pnLog = 0;
2194       pnCkpt = 0;
2195       if( rc==SQLITE_BUSY ){
2196         bBusy = 1;
2197         rc = SQLITE_OK;
2198       }
2199     }
2200   }
2201 
2202   return (rc==SQLITE_OK && bBusy) ? SQLITE_BUSY : rc;
2203 }
2204 #endif /* SQLITE_OMIT_WAL */
2205 
2206 /*
2207 ** This function returns true if main-memory should be used instead of
2208 ** a temporary file for transient pager files and statement journals.
2209 ** The value returned depends on the value of db->temp_store (runtime
2210 ** parameter) and the compile time value of SQLITE_TEMP_STORE. The
2211 ** following table describes the relationship between these two values
2212 ** and this functions return value.
2213 **
2214 **   SQLITE_TEMP_STORE     db->temp_store     Location of temporary database
2215 **   -----------------     --------------     ------------------------------
2216 **   0                     any                file      (return 0)
2217 **   1                     1                  file      (return 0)
2218 **   1                     2                  memory    (return 1)
2219 **   1                     0                  file      (return 0)
2220 **   2                     1                  file      (return 0)
2221 **   2                     2                  memory    (return 1)
2222 **   2                     0                  memory    (return 1)
2223 **   3                     any                memory    (return 1)
2224 */
2225 int sqlite3TempInMemory(const sqlite3 *db){
2226 #if SQLITE_TEMP_STORE==1
2227   return ( db->temp_store==2 );
2228 #endif
2229 #if SQLITE_TEMP_STORE==2
2230   return ( db->temp_store!=1 );
2231 #endif
2232 #if SQLITE_TEMP_STORE==3
2233   UNUSED_PARAMETER(db);
2234   return 1;
2235 #endif
2236 #if SQLITE_TEMP_STORE<1 || SQLITE_TEMP_STORE>3
2237   UNUSED_PARAMETER(db);
2238   return 0;
2239 #endif
2240 }
2241 
2242 /*
2243 ** Return UTF-8 encoded English language explanation of the most recent
2244 ** error.
2245 */
2246 const char *sqlite3_errmsg(sqlite3 *db){
2247   const char *z;
2248   if( !db ){
2249     return sqlite3ErrStr(SQLITE_NOMEM_BKPT);
2250   }
2251   if( !sqlite3SafetyCheckSickOrOk(db) ){
2252     return sqlite3ErrStr(SQLITE_MISUSE_BKPT);
2253   }
2254   sqlite3_mutex_enter(db->mutex);
2255   if( db->mallocFailed ){
2256     z = sqlite3ErrStr(SQLITE_NOMEM_BKPT);
2257   }else{
2258     testcase( db->pErr==0 );
2259     z = (char*)sqlite3_value_text(db->pErr);
2260     assert( !db->mallocFailed );
2261     if( z==0 ){
2262       z = sqlite3ErrStr(db->errCode);
2263     }
2264   }
2265   sqlite3_mutex_leave(db->mutex);
2266   return z;
2267 }
2268 
2269 #ifndef SQLITE_OMIT_UTF16
2270 /*
2271 ** Return UTF-16 encoded English language explanation of the most recent
2272 ** error.
2273 */
2274 const void *sqlite3_errmsg16(sqlite3 *db){
2275   static const u16 outOfMem[] = {
2276     'o', 'u', 't', ' ', 'o', 'f', ' ', 'm', 'e', 'm', 'o', 'r', 'y', 0
2277   };
2278   static const u16 misuse[] = {
2279     'b', 'a', 'd', ' ', 'p', 'a', 'r', 'a', 'm', 'e', 't', 'e', 'r', ' ',
2280     'o', 'r', ' ', 'o', 't', 'h', 'e', 'r', ' ', 'A', 'P', 'I', ' ',
2281     'm', 'i', 's', 'u', 's', 'e', 0
2282   };
2283 
2284   const void *z;
2285   if( !db ){
2286     return (void *)outOfMem;
2287   }
2288   if( !sqlite3SafetyCheckSickOrOk(db) ){
2289     return (void *)misuse;
2290   }
2291   sqlite3_mutex_enter(db->mutex);
2292   if( db->mallocFailed ){
2293     z = (void *)outOfMem;
2294   }else{
2295     z = sqlite3_value_text16(db->pErr);
2296     if( z==0 ){
2297       sqlite3ErrorWithMsg(db, db->errCode, sqlite3ErrStr(db->errCode));
2298       z = sqlite3_value_text16(db->pErr);
2299     }
2300     /* A malloc() may have failed within the call to sqlite3_value_text16()
2301     ** above. If this is the case, then the db->mallocFailed flag needs to
2302     ** be cleared before returning. Do this directly, instead of via
2303     ** sqlite3ApiExit(), to avoid setting the database handle error message.
2304     */
2305     sqlite3OomClear(db);
2306   }
2307   sqlite3_mutex_leave(db->mutex);
2308   return z;
2309 }
2310 #endif /* SQLITE_OMIT_UTF16 */
2311 
2312 /*
2313 ** Return the most recent error code generated by an SQLite routine. If NULL is
2314 ** passed to this function, we assume a malloc() failed during sqlite3_open().
2315 */
2316 int sqlite3_errcode(sqlite3 *db){
2317   if( db && !sqlite3SafetyCheckSickOrOk(db) ){
2318     return SQLITE_MISUSE_BKPT;
2319   }
2320   if( !db || db->mallocFailed ){
2321     return SQLITE_NOMEM_BKPT;
2322   }
2323   return db->errCode & db->errMask;
2324 }
2325 int sqlite3_extended_errcode(sqlite3 *db){
2326   if( db && !sqlite3SafetyCheckSickOrOk(db) ){
2327     return SQLITE_MISUSE_BKPT;
2328   }
2329   if( !db || db->mallocFailed ){
2330     return SQLITE_NOMEM_BKPT;
2331   }
2332   return db->errCode;
2333 }
2334 int sqlite3_system_errno(sqlite3 *db){
2335   return db ? db->iSysErrno : 0;
2336 }
2337 
2338 /*
2339 ** Return a string that describes the kind of error specified in the
2340 ** argument.  For now, this simply calls the internal sqlite3ErrStr()
2341 ** function.
2342 */
2343 const char *sqlite3_errstr(int rc){
2344   return sqlite3ErrStr(rc);
2345 }
2346 
2347 /*
2348 ** Create a new collating function for database "db".  The name is zName
2349 ** and the encoding is enc.
2350 */
2351 static int createCollation(
2352   sqlite3* db,
2353   const char *zName,
2354   u8 enc,
2355   void* pCtx,
2356   int(*xCompare)(void*,int,const void*,int,const void*),
2357   void(*xDel)(void*)
2358 ){
2359   CollSeq *pColl;
2360   int enc2;
2361 
2362   assert( sqlite3_mutex_held(db->mutex) );
2363 
2364   /* If SQLITE_UTF16 is specified as the encoding type, transform this
2365   ** to one of SQLITE_UTF16LE or SQLITE_UTF16BE using the
2366   ** SQLITE_UTF16NATIVE macro. SQLITE_UTF16 is not used internally.
2367   */
2368   enc2 = enc;
2369   testcase( enc2==SQLITE_UTF16 );
2370   testcase( enc2==SQLITE_UTF16_ALIGNED );
2371   if( enc2==SQLITE_UTF16 || enc2==SQLITE_UTF16_ALIGNED ){
2372     enc2 = SQLITE_UTF16NATIVE;
2373   }
2374   if( enc2<SQLITE_UTF8 || enc2>SQLITE_UTF16BE ){
2375     return SQLITE_MISUSE_BKPT;
2376   }
2377 
2378   /* Check if this call is removing or replacing an existing collation
2379   ** sequence. If so, and there are active VMs, return busy. If there
2380   ** are no active VMs, invalidate any pre-compiled statements.
2381   */
2382   pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, 0);
2383   if( pColl && pColl->xCmp ){
2384     if( db->nVdbeActive ){
2385       sqlite3ErrorWithMsg(db, SQLITE_BUSY,
2386         "unable to delete/modify collation sequence due to active statements");
2387       return SQLITE_BUSY;
2388     }
2389     sqlite3ExpirePreparedStatements(db);
2390 
2391     /* If collation sequence pColl was created directly by a call to
2392     ** sqlite3_create_collation, and not generated by synthCollSeq(),
2393     ** then any copies made by synthCollSeq() need to be invalidated.
2394     ** Also, collation destructor - CollSeq.xDel() - function may need
2395     ** to be called.
2396     */
2397     if( (pColl->enc & ~SQLITE_UTF16_ALIGNED)==enc2 ){
2398       CollSeq *aColl = sqlite3HashFind(&db->aCollSeq, zName);
2399       int j;
2400       for(j=0; j<3; j++){
2401         CollSeq *p = &aColl[j];
2402         if( p->enc==pColl->enc ){
2403           if( p->xDel ){
2404             p->xDel(p->pUser);
2405           }
2406           p->xCmp = 0;
2407         }
2408       }
2409     }
2410   }
2411 
2412   pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, 1);
2413   if( pColl==0 ) return SQLITE_NOMEM_BKPT;
2414   pColl->xCmp = xCompare;
2415   pColl->pUser = pCtx;
2416   pColl->xDel = xDel;
2417   pColl->enc = (u8)(enc2 | (enc & SQLITE_UTF16_ALIGNED));
2418   sqlite3Error(db, SQLITE_OK);
2419   return SQLITE_OK;
2420 }
2421 
2422 
2423 /*
2424 ** This array defines hard upper bounds on limit values.  The
2425 ** initializer must be kept in sync with the SQLITE_LIMIT_*
2426 ** #defines in sqlite3.h.
2427 */
2428 static const int aHardLimit[] = {
2429   SQLITE_MAX_LENGTH,
2430   SQLITE_MAX_SQL_LENGTH,
2431   SQLITE_MAX_COLUMN,
2432   SQLITE_MAX_EXPR_DEPTH,
2433   SQLITE_MAX_COMPOUND_SELECT,
2434   SQLITE_MAX_VDBE_OP,
2435   SQLITE_MAX_FUNCTION_ARG,
2436   SQLITE_MAX_ATTACHED,
2437   SQLITE_MAX_LIKE_PATTERN_LENGTH,
2438   SQLITE_MAX_VARIABLE_NUMBER,      /* IMP: R-38091-32352 */
2439   SQLITE_MAX_TRIGGER_DEPTH,
2440   SQLITE_MAX_WORKER_THREADS,
2441 };
2442 
2443 /*
2444 ** Make sure the hard limits are set to reasonable values
2445 */
2446 #if SQLITE_MAX_LENGTH<100
2447 # error SQLITE_MAX_LENGTH must be at least 100
2448 #endif
2449 #if SQLITE_MAX_SQL_LENGTH<100
2450 # error SQLITE_MAX_SQL_LENGTH must be at least 100
2451 #endif
2452 #if SQLITE_MAX_SQL_LENGTH>SQLITE_MAX_LENGTH
2453 # error SQLITE_MAX_SQL_LENGTH must not be greater than SQLITE_MAX_LENGTH
2454 #endif
2455 #if SQLITE_MAX_COMPOUND_SELECT<2
2456 # error SQLITE_MAX_COMPOUND_SELECT must be at least 2
2457 #endif
2458 #if SQLITE_MAX_VDBE_OP<40
2459 # error SQLITE_MAX_VDBE_OP must be at least 40
2460 #endif
2461 #if SQLITE_MAX_FUNCTION_ARG<0 || SQLITE_MAX_FUNCTION_ARG>127
2462 # error SQLITE_MAX_FUNCTION_ARG must be between 0 and 127
2463 #endif
2464 #if SQLITE_MAX_ATTACHED<0 || SQLITE_MAX_ATTACHED>125
2465 # error SQLITE_MAX_ATTACHED must be between 0 and 125
2466 #endif
2467 #if SQLITE_MAX_LIKE_PATTERN_LENGTH<1
2468 # error SQLITE_MAX_LIKE_PATTERN_LENGTH must be at least 1
2469 #endif
2470 #if SQLITE_MAX_COLUMN>32767
2471 # error SQLITE_MAX_COLUMN must not exceed 32767
2472 #endif
2473 #if SQLITE_MAX_TRIGGER_DEPTH<1
2474 # error SQLITE_MAX_TRIGGER_DEPTH must be at least 1
2475 #endif
2476 #if SQLITE_MAX_WORKER_THREADS<0 || SQLITE_MAX_WORKER_THREADS>50
2477 # error SQLITE_MAX_WORKER_THREADS must be between 0 and 50
2478 #endif
2479 
2480 
2481 /*
2482 ** Change the value of a limit.  Report the old value.
2483 ** If an invalid limit index is supplied, report -1.
2484 ** Make no changes but still report the old value if the
2485 ** new limit is negative.
2486 **
2487 ** A new lower limit does not shrink existing constructs.
2488 ** It merely prevents new constructs that exceed the limit
2489 ** from forming.
2490 */
2491 int sqlite3_limit(sqlite3 *db, int limitId, int newLimit){
2492   int oldLimit;
2493 
2494 #ifdef SQLITE_ENABLE_API_ARMOR
2495   if( !sqlite3SafetyCheckOk(db) ){
2496     (void)SQLITE_MISUSE_BKPT;
2497     return -1;
2498   }
2499 #endif
2500 
2501   /* EVIDENCE-OF: R-30189-54097 For each limit category SQLITE_LIMIT_NAME
2502   ** there is a hard upper bound set at compile-time by a C preprocessor
2503   ** macro called SQLITE_MAX_NAME. (The "_LIMIT_" in the name is changed to
2504   ** "_MAX_".)
2505   */
2506   assert( aHardLimit[SQLITE_LIMIT_LENGTH]==SQLITE_MAX_LENGTH );
2507   assert( aHardLimit[SQLITE_LIMIT_SQL_LENGTH]==SQLITE_MAX_SQL_LENGTH );
2508   assert( aHardLimit[SQLITE_LIMIT_COLUMN]==SQLITE_MAX_COLUMN );
2509   assert( aHardLimit[SQLITE_LIMIT_EXPR_DEPTH]==SQLITE_MAX_EXPR_DEPTH );
2510   assert( aHardLimit[SQLITE_LIMIT_COMPOUND_SELECT]==SQLITE_MAX_COMPOUND_SELECT);
2511   assert( aHardLimit[SQLITE_LIMIT_VDBE_OP]==SQLITE_MAX_VDBE_OP );
2512   assert( aHardLimit[SQLITE_LIMIT_FUNCTION_ARG]==SQLITE_MAX_FUNCTION_ARG );
2513   assert( aHardLimit[SQLITE_LIMIT_ATTACHED]==SQLITE_MAX_ATTACHED );
2514   assert( aHardLimit[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]==
2515                                                SQLITE_MAX_LIKE_PATTERN_LENGTH );
2516   assert( aHardLimit[SQLITE_LIMIT_VARIABLE_NUMBER]==SQLITE_MAX_VARIABLE_NUMBER);
2517   assert( aHardLimit[SQLITE_LIMIT_TRIGGER_DEPTH]==SQLITE_MAX_TRIGGER_DEPTH );
2518   assert( aHardLimit[SQLITE_LIMIT_WORKER_THREADS]==SQLITE_MAX_WORKER_THREADS );
2519   assert( SQLITE_LIMIT_WORKER_THREADS==(SQLITE_N_LIMIT-1) );
2520 
2521 
2522   if( limitId<0 || limitId>=SQLITE_N_LIMIT ){
2523     return -1;
2524   }
2525   oldLimit = db->aLimit[limitId];
2526   if( newLimit>=0 ){                   /* IMP: R-52476-28732 */
2527     if( newLimit>aHardLimit[limitId] ){
2528       newLimit = aHardLimit[limitId];  /* IMP: R-51463-25634 */
2529     }
2530     db->aLimit[limitId] = newLimit;
2531   }
2532   return oldLimit;                     /* IMP: R-53341-35419 */
2533 }
2534 
2535 /*
2536 ** This function is used to parse both URIs and non-URI filenames passed by the
2537 ** user to API functions sqlite3_open() or sqlite3_open_v2(), and for database
2538 ** URIs specified as part of ATTACH statements.
2539 **
2540 ** The first argument to this function is the name of the VFS to use (or
2541 ** a NULL to signify the default VFS) if the URI does not contain a "vfs=xxx"
2542 ** query parameter. The second argument contains the URI (or non-URI filename)
2543 ** itself. When this function is called the *pFlags variable should contain
2544 ** the default flags to open the database handle with. The value stored in
2545 ** *pFlags may be updated before returning if the URI filename contains
2546 ** "cache=xxx" or "mode=xxx" query parameters.
2547 **
2548 ** If successful, SQLITE_OK is returned. In this case *ppVfs is set to point to
2549 ** the VFS that should be used to open the database file. *pzFile is set to
2550 ** point to a buffer containing the name of the file to open. It is the
2551 ** responsibility of the caller to eventually call sqlite3_free() to release
2552 ** this buffer.
2553 **
2554 ** If an error occurs, then an SQLite error code is returned and *pzErrMsg
2555 ** may be set to point to a buffer containing an English language error
2556 ** message. It is the responsibility of the caller to eventually release
2557 ** this buffer by calling sqlite3_free().
2558 */
2559 int sqlite3ParseUri(
2560   const char *zDefaultVfs,        /* VFS to use if no "vfs=xxx" query option */
2561   const char *zUri,               /* Nul-terminated URI to parse */
2562   unsigned int *pFlags,           /* IN/OUT: SQLITE_OPEN_XXX flags */
2563   sqlite3_vfs **ppVfs,            /* OUT: VFS to use */
2564   char **pzFile,                  /* OUT: Filename component of URI */
2565   char **pzErrMsg                 /* OUT: Error message (if rc!=SQLITE_OK) */
2566 ){
2567   int rc = SQLITE_OK;
2568   unsigned int flags = *pFlags;
2569   const char *zVfs = zDefaultVfs;
2570   char *zFile;
2571   char c;
2572   int nUri = sqlite3Strlen30(zUri);
2573 
2574   assert( *pzErrMsg==0 );
2575 
2576   if( ((flags & SQLITE_OPEN_URI)             /* IMP: R-48725-32206 */
2577             || sqlite3GlobalConfig.bOpenUri) /* IMP: R-51689-46548 */
2578    && nUri>=5 && memcmp(zUri, "file:", 5)==0 /* IMP: R-57884-37496 */
2579   ){
2580     char *zOpt;
2581     int eState;                   /* Parser state when parsing URI */
2582     int iIn;                      /* Input character index */
2583     int iOut = 0;                 /* Output character index */
2584     u64 nByte = nUri+2;           /* Bytes of space to allocate */
2585 
2586     /* Make sure the SQLITE_OPEN_URI flag is set to indicate to the VFS xOpen
2587     ** method that there may be extra parameters following the file-name.  */
2588     flags |= SQLITE_OPEN_URI;
2589 
2590     for(iIn=0; iIn<nUri; iIn++) nByte += (zUri[iIn]=='&');
2591     zFile = sqlite3_malloc64(nByte);
2592     if( !zFile ) return SQLITE_NOMEM_BKPT;
2593 
2594     iIn = 5;
2595 #ifdef SQLITE_ALLOW_URI_AUTHORITY
2596     if( strncmp(zUri+5, "///", 3)==0 ){
2597       iIn = 7;
2598       /* The following condition causes URIs with five leading / characters
2599       ** like file://///host/path to be converted into UNCs like //host/path.
2600       ** The correct URI for that UNC has only two or four leading / characters
2601       ** file://host/path or file:////host/path.  But 5 leading slashes is a
2602       ** common error, we are told, so we handle it as a special case. */
2603       if( strncmp(zUri+7, "///", 3)==0 ){ iIn++; }
2604     }else if( strncmp(zUri+5, "//localhost/", 12)==0 ){
2605       iIn = 16;
2606     }
2607 #else
2608     /* Discard the scheme and authority segments of the URI. */
2609     if( zUri[5]=='/' && zUri[6]=='/' ){
2610       iIn = 7;
2611       while( zUri[iIn] && zUri[iIn]!='/' ) iIn++;
2612       if( iIn!=7 && (iIn!=16 || memcmp("localhost", &zUri[7], 9)) ){
2613         *pzErrMsg = sqlite3_mprintf("invalid uri authority: %.*s",
2614             iIn-7, &zUri[7]);
2615         rc = SQLITE_ERROR;
2616         goto parse_uri_out;
2617       }
2618     }
2619 #endif
2620 
2621     /* Copy the filename and any query parameters into the zFile buffer.
2622     ** Decode %HH escape codes along the way.
2623     **
2624     ** Within this loop, variable eState may be set to 0, 1 or 2, depending
2625     ** on the parsing context. As follows:
2626     **
2627     **   0: Parsing file-name.
2628     **   1: Parsing name section of a name=value query parameter.
2629     **   2: Parsing value section of a name=value query parameter.
2630     */
2631     eState = 0;
2632     while( (c = zUri[iIn])!=0 && c!='#' ){
2633       iIn++;
2634       if( c=='%'
2635        && sqlite3Isxdigit(zUri[iIn])
2636        && sqlite3Isxdigit(zUri[iIn+1])
2637       ){
2638         int octet = (sqlite3HexToInt(zUri[iIn++]) << 4);
2639         octet += sqlite3HexToInt(zUri[iIn++]);
2640 
2641         assert( octet>=0 && octet<256 );
2642         if( octet==0 ){
2643 #ifndef SQLITE_ENABLE_URI_00_ERROR
2644           /* This branch is taken when "%00" appears within the URI. In this
2645           ** case we ignore all text in the remainder of the path, name or
2646           ** value currently being parsed. So ignore the current character
2647           ** and skip to the next "?", "=" or "&", as appropriate. */
2648           while( (c = zUri[iIn])!=0 && c!='#'
2649               && (eState!=0 || c!='?')
2650               && (eState!=1 || (c!='=' && c!='&'))
2651               && (eState!=2 || c!='&')
2652           ){
2653             iIn++;
2654           }
2655           continue;
2656 #else
2657           /* If ENABLE_URI_00_ERROR is defined, "%00" in a URI is an error. */
2658           *pzErrMsg = sqlite3_mprintf("unexpected %%00 in uri");
2659           rc = SQLITE_ERROR;
2660           goto parse_uri_out;
2661 #endif
2662         }
2663         c = octet;
2664       }else if( eState==1 && (c=='&' || c=='=') ){
2665         if( zFile[iOut-1]==0 ){
2666           /* An empty option name. Ignore this option altogether. */
2667           while( zUri[iIn] && zUri[iIn]!='#' && zUri[iIn-1]!='&' ) iIn++;
2668           continue;
2669         }
2670         if( c=='&' ){
2671           zFile[iOut++] = '\0';
2672         }else{
2673           eState = 2;
2674         }
2675         c = 0;
2676       }else if( (eState==0 && c=='?') || (eState==2 && c=='&') ){
2677         c = 0;
2678         eState = 1;
2679       }
2680       zFile[iOut++] = c;
2681     }
2682     if( eState==1 ) zFile[iOut++] = '\0';
2683     zFile[iOut++] = '\0';
2684     zFile[iOut++] = '\0';
2685 
2686     /* Check if there were any options specified that should be interpreted
2687     ** here. Options that are interpreted here include "vfs" and those that
2688     ** correspond to flags that may be passed to the sqlite3_open_v2()
2689     ** method. */
2690     zOpt = &zFile[sqlite3Strlen30(zFile)+1];
2691     while( zOpt[0] ){
2692       int nOpt = sqlite3Strlen30(zOpt);
2693       char *zVal = &zOpt[nOpt+1];
2694       int nVal = sqlite3Strlen30(zVal);
2695 
2696       if( nOpt==3 && memcmp("vfs", zOpt, 3)==0 ){
2697         zVfs = zVal;
2698       }else{
2699         struct OpenMode {
2700           const char *z;
2701           int mode;
2702         } *aMode = 0;
2703         char *zModeType = 0;
2704         int mask = 0;
2705         int limit = 0;
2706 
2707         if( nOpt==5 && memcmp("cache", zOpt, 5)==0 ){
2708           static struct OpenMode aCacheMode[] = {
2709             { "shared",  SQLITE_OPEN_SHAREDCACHE },
2710             { "private", SQLITE_OPEN_PRIVATECACHE },
2711             { 0, 0 }
2712           };
2713 
2714           mask = SQLITE_OPEN_SHAREDCACHE|SQLITE_OPEN_PRIVATECACHE;
2715           aMode = aCacheMode;
2716           limit = mask;
2717           zModeType = "cache";
2718         }
2719         if( nOpt==4 && memcmp("mode", zOpt, 4)==0 ){
2720           static struct OpenMode aOpenMode[] = {
2721             { "ro",  SQLITE_OPEN_READONLY },
2722             { "rw",  SQLITE_OPEN_READWRITE },
2723             { "rwc", SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE },
2724             { "memory", SQLITE_OPEN_MEMORY },
2725             { 0, 0 }
2726           };
2727 
2728           mask = SQLITE_OPEN_READONLY | SQLITE_OPEN_READWRITE
2729                    | SQLITE_OPEN_CREATE | SQLITE_OPEN_MEMORY;
2730           aMode = aOpenMode;
2731           limit = mask & flags;
2732           zModeType = "access";
2733         }
2734 
2735         if( aMode ){
2736           int i;
2737           int mode = 0;
2738           for(i=0; aMode[i].z; i++){
2739             const char *z = aMode[i].z;
2740             if( nVal==sqlite3Strlen30(z) && 0==memcmp(zVal, z, nVal) ){
2741               mode = aMode[i].mode;
2742               break;
2743             }
2744           }
2745           if( mode==0 ){
2746             *pzErrMsg = sqlite3_mprintf("no such %s mode: %s", zModeType, zVal);
2747             rc = SQLITE_ERROR;
2748             goto parse_uri_out;
2749           }
2750           if( (mode & ~SQLITE_OPEN_MEMORY)>limit ){
2751             *pzErrMsg = sqlite3_mprintf("%s mode not allowed: %s",
2752                                         zModeType, zVal);
2753             rc = SQLITE_PERM;
2754             goto parse_uri_out;
2755           }
2756           flags = (flags & ~mask) | mode;
2757         }
2758       }
2759 
2760       zOpt = &zVal[nVal+1];
2761     }
2762 
2763   }else{
2764     zFile = sqlite3_malloc64(nUri+2);
2765     if( !zFile ) return SQLITE_NOMEM_BKPT;
2766     if( nUri ){
2767       memcpy(zFile, zUri, nUri);
2768     }
2769     zFile[nUri] = '\0';
2770     zFile[nUri+1] = '\0';
2771     flags &= ~SQLITE_OPEN_URI;
2772   }
2773 
2774   *ppVfs = sqlite3_vfs_find(zVfs);
2775   if( *ppVfs==0 ){
2776     *pzErrMsg = sqlite3_mprintf("no such vfs: %s", zVfs);
2777     rc = SQLITE_ERROR;
2778   }
2779  parse_uri_out:
2780   if( rc!=SQLITE_OK ){
2781     sqlite3_free(zFile);
2782     zFile = 0;
2783   }
2784   *pFlags = flags;
2785   *pzFile = zFile;
2786   return rc;
2787 }
2788 
2789 
2790 /*
2791 ** This routine does the work of opening a database on behalf of
2792 ** sqlite3_open() and sqlite3_open16(). The database filename "zFilename"
2793 ** is UTF-8 encoded.
2794 */
2795 static int openDatabase(
2796   const char *zFilename, /* Database filename UTF-8 encoded */
2797   sqlite3 **ppDb,        /* OUT: Returned database handle */
2798   unsigned int flags,    /* Operational flags */
2799   const char *zVfs       /* Name of the VFS to use */
2800 ){
2801   sqlite3 *db;                    /* Store allocated handle here */
2802   int rc;                         /* Return code */
2803   int isThreadsafe;               /* True for threadsafe connections */
2804   char *zOpen = 0;                /* Filename argument to pass to BtreeOpen() */
2805   char *zErrMsg = 0;              /* Error message from sqlite3ParseUri() */
2806 
2807 #ifdef SQLITE_ENABLE_API_ARMOR
2808   if( ppDb==0 ) return SQLITE_MISUSE_BKPT;
2809 #endif
2810   *ppDb = 0;
2811 #ifndef SQLITE_OMIT_AUTOINIT
2812   rc = sqlite3_initialize();
2813   if( rc ) return rc;
2814 #endif
2815 
2816   if( sqlite3GlobalConfig.bCoreMutex==0 ){
2817     isThreadsafe = 0;
2818   }else if( flags & SQLITE_OPEN_NOMUTEX ){
2819     isThreadsafe = 0;
2820   }else if( flags & SQLITE_OPEN_FULLMUTEX ){
2821     isThreadsafe = 1;
2822   }else{
2823     isThreadsafe = sqlite3GlobalConfig.bFullMutex;
2824   }
2825 
2826   if( flags & SQLITE_OPEN_PRIVATECACHE ){
2827     flags &= ~SQLITE_OPEN_SHAREDCACHE;
2828   }else if( sqlite3GlobalConfig.sharedCacheEnabled ){
2829     flags |= SQLITE_OPEN_SHAREDCACHE;
2830   }
2831 
2832   /* Remove harmful bits from the flags parameter
2833   **
2834   ** The SQLITE_OPEN_NOMUTEX and SQLITE_OPEN_FULLMUTEX flags were
2835   ** dealt with in the previous code block.  Besides these, the only
2836   ** valid input flags for sqlite3_open_v2() are SQLITE_OPEN_READONLY,
2837   ** SQLITE_OPEN_READWRITE, SQLITE_OPEN_CREATE, SQLITE_OPEN_SHAREDCACHE,
2838   ** SQLITE_OPEN_PRIVATECACHE, and some reserved bits.  Silently mask
2839   ** off all other flags.
2840   */
2841   flags &=  ~( SQLITE_OPEN_DELETEONCLOSE |
2842                SQLITE_OPEN_EXCLUSIVE |
2843                SQLITE_OPEN_MAIN_DB |
2844                SQLITE_OPEN_TEMP_DB |
2845                SQLITE_OPEN_TRANSIENT_DB |
2846                SQLITE_OPEN_MAIN_JOURNAL |
2847                SQLITE_OPEN_TEMP_JOURNAL |
2848                SQLITE_OPEN_SUBJOURNAL |
2849                SQLITE_OPEN_MASTER_JOURNAL |
2850                SQLITE_OPEN_NOMUTEX |
2851                SQLITE_OPEN_FULLMUTEX |
2852                SQLITE_OPEN_WAL
2853              );
2854 
2855   /* Allocate the sqlite data structure */
2856   db = sqlite3MallocZero( sizeof(sqlite3) );
2857   if( db==0 ) goto opendb_out;
2858   if( isThreadsafe
2859 #ifdef SQLITE_ENABLE_MULTITHREADED_CHECKS
2860    || sqlite3GlobalConfig.bCoreMutex
2861 #endif
2862   ){
2863     db->mutex = sqlite3MutexAlloc(SQLITE_MUTEX_RECURSIVE);
2864     if( db->mutex==0 ){
2865       sqlite3_free(db);
2866       db = 0;
2867       goto opendb_out;
2868     }
2869     if( isThreadsafe==0 ){
2870       sqlite3MutexWarnOnContention(db->mutex);
2871     }
2872   }
2873   sqlite3_mutex_enter(db->mutex);
2874   db->errMask = 0xff;
2875   db->nDb = 2;
2876   db->magic = SQLITE_MAGIC_BUSY;
2877   db->aDb = db->aDbStatic;
2878 
2879   assert( sizeof(db->aLimit)==sizeof(aHardLimit) );
2880   memcpy(db->aLimit, aHardLimit, sizeof(db->aLimit));
2881   db->aLimit[SQLITE_LIMIT_WORKER_THREADS] = SQLITE_DEFAULT_WORKER_THREADS;
2882   db->autoCommit = 1;
2883   db->nextAutovac = -1;
2884   db->szMmap = sqlite3GlobalConfig.szMmap;
2885   db->nextPagesize = 0;
2886   db->nMaxSorterMmap = 0x7FFFFFFF;
2887   db->flags |= SQLITE_ShortColNames | SQLITE_EnableTrigger | SQLITE_CacheSpill
2888 #if !defined(SQLITE_DEFAULT_AUTOMATIC_INDEX) || SQLITE_DEFAULT_AUTOMATIC_INDEX
2889                  | SQLITE_AutoIndex
2890 #endif
2891 #if SQLITE_DEFAULT_CKPTFULLFSYNC
2892                  | SQLITE_CkptFullFSync
2893 #endif
2894 #if SQLITE_DEFAULT_FILE_FORMAT<4
2895                  | SQLITE_LegacyFileFmt
2896 #endif
2897 #ifdef SQLITE_ENABLE_LOAD_EXTENSION
2898                  | SQLITE_LoadExtension
2899 #endif
2900 #if SQLITE_DEFAULT_RECURSIVE_TRIGGERS
2901                  | SQLITE_RecTriggers
2902 #endif
2903 #if defined(SQLITE_DEFAULT_FOREIGN_KEYS) && SQLITE_DEFAULT_FOREIGN_KEYS
2904                  | SQLITE_ForeignKeys
2905 #endif
2906 #if defined(SQLITE_REVERSE_UNORDERED_SELECTS)
2907                  | SQLITE_ReverseOrder
2908 #endif
2909 #if defined(SQLITE_ENABLE_OVERSIZE_CELL_CHECK)
2910                  | SQLITE_CellSizeCk
2911 #endif
2912 #if defined(SQLITE_ENABLE_FTS3_TOKENIZER)
2913                  | SQLITE_Fts3Tokenizer
2914 #endif
2915 #if defined(SQLITE_ENABLE_QPSG)
2916                  | SQLITE_EnableQPSG
2917 #endif
2918       ;
2919   sqlite3HashInit(&db->aCollSeq);
2920 #ifndef SQLITE_OMIT_VIRTUALTABLE
2921   sqlite3HashInit(&db->aModule);
2922 #endif
2923 
2924   /* Add the default collation sequence BINARY. BINARY works for both UTF-8
2925   ** and UTF-16, so add a version for each to avoid any unnecessary
2926   ** conversions. The only error that can occur here is a malloc() failure.
2927   **
2928   ** EVIDENCE-OF: R-52786-44878 SQLite defines three built-in collating
2929   ** functions:
2930   */
2931   createCollation(db, sqlite3StrBINARY, SQLITE_UTF8, 0, binCollFunc, 0);
2932   createCollation(db, sqlite3StrBINARY, SQLITE_UTF16BE, 0, binCollFunc, 0);
2933   createCollation(db, sqlite3StrBINARY, SQLITE_UTF16LE, 0, binCollFunc, 0);
2934   createCollation(db, "NOCASE", SQLITE_UTF8, 0, nocaseCollatingFunc, 0);
2935   createCollation(db, "RTRIM", SQLITE_UTF8, (void*)1, binCollFunc, 0);
2936   if( db->mallocFailed ){
2937     goto opendb_out;
2938   }
2939   /* EVIDENCE-OF: R-08308-17224 The default collating function for all
2940   ** strings is BINARY.
2941   */
2942   db->pDfltColl = sqlite3FindCollSeq(db, SQLITE_UTF8, sqlite3StrBINARY, 0);
2943   assert( db->pDfltColl!=0 );
2944 
2945   /* Parse the filename/URI argument
2946   **
2947   ** Only allow sensible combinations of bits in the flags argument.
2948   ** Throw an error if any non-sense combination is used.  If we
2949   ** do not block illegal combinations here, it could trigger
2950   ** assert() statements in deeper layers.  Sensible combinations
2951   ** are:
2952   **
2953   **  1:  SQLITE_OPEN_READONLY
2954   **  2:  SQLITE_OPEN_READWRITE
2955   **  6:  SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE
2956   */
2957   db->openFlags = flags;
2958   assert( SQLITE_OPEN_READONLY  == 0x01 );
2959   assert( SQLITE_OPEN_READWRITE == 0x02 );
2960   assert( SQLITE_OPEN_CREATE    == 0x04 );
2961   testcase( (1<<(flags&7))==0x02 ); /* READONLY */
2962   testcase( (1<<(flags&7))==0x04 ); /* READWRITE */
2963   testcase( (1<<(flags&7))==0x40 ); /* READWRITE | CREATE */
2964   if( ((1<<(flags&7)) & 0x46)==0 ){
2965     rc = SQLITE_MISUSE_BKPT;  /* IMP: R-65497-44594 */
2966   }else{
2967     rc = sqlite3ParseUri(zVfs, zFilename, &flags, &db->pVfs, &zOpen, &zErrMsg);
2968   }
2969   if( rc!=SQLITE_OK ){
2970     if( rc==SQLITE_NOMEM ) sqlite3OomFault(db);
2971     sqlite3ErrorWithMsg(db, rc, zErrMsg ? "%s" : 0, zErrMsg);
2972     sqlite3_free(zErrMsg);
2973     goto opendb_out;
2974   }
2975 
2976   /* Open the backend database driver */
2977   rc = sqlite3BtreeOpen(db->pVfs, zOpen, db, &db->aDb[0].pBt, 0,
2978                         flags | SQLITE_OPEN_MAIN_DB);
2979   if( rc!=SQLITE_OK ){
2980     if( rc==SQLITE_IOERR_NOMEM ){
2981       rc = SQLITE_NOMEM_BKPT;
2982     }
2983     sqlite3Error(db, rc);
2984     goto opendb_out;
2985   }
2986   sqlite3BtreeEnter(db->aDb[0].pBt);
2987   db->aDb[0].pSchema = sqlite3SchemaGet(db, db->aDb[0].pBt);
2988   if( !db->mallocFailed ) ENC(db) = SCHEMA_ENC(db);
2989   sqlite3BtreeLeave(db->aDb[0].pBt);
2990   db->aDb[1].pSchema = sqlite3SchemaGet(db, 0);
2991 
2992   /* The default safety_level for the main database is FULL; for the temp
2993   ** database it is OFF. This matches the pager layer defaults.
2994   */
2995   db->aDb[0].zDbSName = "main";
2996   db->aDb[0].safety_level = SQLITE_DEFAULT_SYNCHRONOUS+1;
2997   db->aDb[1].zDbSName = "temp";
2998   db->aDb[1].safety_level = PAGER_SYNCHRONOUS_OFF;
2999 
3000   db->magic = SQLITE_MAGIC_OPEN;
3001   if( db->mallocFailed ){
3002     goto opendb_out;
3003   }
3004 
3005   /* Register all built-in functions, but do not attempt to read the
3006   ** database schema yet. This is delayed until the first time the database
3007   ** is accessed.
3008   */
3009   sqlite3Error(db, SQLITE_OK);
3010   sqlite3RegisterPerConnectionBuiltinFunctions(db);
3011   rc = sqlite3_errcode(db);
3012 
3013 #ifdef SQLITE_ENABLE_FTS5
3014   /* Register any built-in FTS5 module before loading the automatic
3015   ** extensions. This allows automatic extensions to register FTS5
3016   ** tokenizers and auxiliary functions.  */
3017   if( !db->mallocFailed && rc==SQLITE_OK ){
3018     rc = sqlite3Fts5Init(db);
3019   }
3020 #endif
3021 
3022   /* Load automatic extensions - extensions that have been registered
3023   ** using the sqlite3_automatic_extension() API.
3024   */
3025   if( rc==SQLITE_OK ){
3026     sqlite3AutoLoadExtensions(db);
3027     rc = sqlite3_errcode(db);
3028     if( rc!=SQLITE_OK ){
3029       goto opendb_out;
3030     }
3031   }
3032 
3033 #ifdef SQLITE_ENABLE_FTS1
3034   if( !db->mallocFailed ){
3035     extern int sqlite3Fts1Init(sqlite3*);
3036     rc = sqlite3Fts1Init(db);
3037   }
3038 #endif
3039 
3040 #ifdef SQLITE_ENABLE_FTS2
3041   if( !db->mallocFailed && rc==SQLITE_OK ){
3042     extern int sqlite3Fts2Init(sqlite3*);
3043     rc = sqlite3Fts2Init(db);
3044   }
3045 #endif
3046 
3047 #ifdef SQLITE_ENABLE_FTS3 /* automatically defined by SQLITE_ENABLE_FTS4 */
3048   if( !db->mallocFailed && rc==SQLITE_OK ){
3049     rc = sqlite3Fts3Init(db);
3050   }
3051 #endif
3052 
3053 #ifdef SQLITE_ENABLE_ICU
3054   if( !db->mallocFailed && rc==SQLITE_OK ){
3055     rc = sqlite3IcuInit(db);
3056   }
3057 #endif
3058 
3059 #ifdef SQLITE_ENABLE_RTREE
3060   if( !db->mallocFailed && rc==SQLITE_OK){
3061     rc = sqlite3RtreeInit(db);
3062   }
3063 #endif
3064 
3065 #ifdef SQLITE_ENABLE_DBPAGE_VTAB
3066   if( !db->mallocFailed && rc==SQLITE_OK){
3067     rc = sqlite3DbpageRegister(db);
3068   }
3069 #endif
3070 
3071 #ifdef SQLITE_ENABLE_DBSTAT_VTAB
3072   if( !db->mallocFailed && rc==SQLITE_OK){
3073     rc = sqlite3DbstatRegister(db);
3074   }
3075 #endif
3076 
3077 #ifdef SQLITE_ENABLE_JSON1
3078   if( !db->mallocFailed && rc==SQLITE_OK){
3079     rc = sqlite3Json1Init(db);
3080   }
3081 #endif
3082 
3083 #ifdef SQLITE_ENABLE_STMTVTAB
3084   if( !db->mallocFailed && rc==SQLITE_OK){
3085     rc = sqlite3StmtVtabInit(db);
3086   }
3087 #endif
3088 
3089   /* -DSQLITE_DEFAULT_LOCKING_MODE=1 makes EXCLUSIVE the default locking
3090   ** mode.  -DSQLITE_DEFAULT_LOCKING_MODE=0 make NORMAL the default locking
3091   ** mode.  Doing nothing at all also makes NORMAL the default.
3092   */
3093 #ifdef SQLITE_DEFAULT_LOCKING_MODE
3094   db->dfltLockMode = SQLITE_DEFAULT_LOCKING_MODE;
3095   sqlite3PagerLockingMode(sqlite3BtreePager(db->aDb[0].pBt),
3096                           SQLITE_DEFAULT_LOCKING_MODE);
3097 #endif
3098 
3099   if( rc ) sqlite3Error(db, rc);
3100 
3101   /* Enable the lookaside-malloc subsystem */
3102   setupLookaside(db, 0, sqlite3GlobalConfig.szLookaside,
3103                         sqlite3GlobalConfig.nLookaside);
3104 
3105   sqlite3_wal_autocheckpoint(db, SQLITE_DEFAULT_WAL_AUTOCHECKPOINT);
3106 
3107 opendb_out:
3108   if( db ){
3109     assert( db->mutex!=0 || isThreadsafe==0
3110            || sqlite3GlobalConfig.bFullMutex==0 );
3111     sqlite3_mutex_leave(db->mutex);
3112   }
3113   rc = sqlite3_errcode(db);
3114   assert( db!=0 || rc==SQLITE_NOMEM );
3115   if( rc==SQLITE_NOMEM ){
3116     sqlite3_close(db);
3117     db = 0;
3118   }else if( rc!=SQLITE_OK ){
3119     db->magic = SQLITE_MAGIC_SICK;
3120   }
3121   *ppDb = db;
3122 #ifdef SQLITE_ENABLE_SQLLOG
3123   if( sqlite3GlobalConfig.xSqllog ){
3124     /* Opening a db handle. Fourth parameter is passed 0. */
3125     void *pArg = sqlite3GlobalConfig.pSqllogArg;
3126     sqlite3GlobalConfig.xSqllog(pArg, db, zFilename, 0);
3127   }
3128 #endif
3129 #if defined(SQLITE_HAS_CODEC)
3130   if( rc==SQLITE_OK ){
3131     const char *zKey;
3132     if( (zKey = sqlite3_uri_parameter(zOpen, "hexkey"))!=0 && zKey[0] ){
3133       u8 iByte;
3134       int i;
3135       char zDecoded[40];
3136       for(i=0, iByte=0; i<sizeof(zDecoded)*2 && sqlite3Isxdigit(zKey[i]); i++){
3137         iByte = (iByte<<4) + sqlite3HexToInt(zKey[i]);
3138         if( (i&1)!=0 ) zDecoded[i/2] = iByte;
3139       }
3140       sqlite3_key_v2(db, 0, zDecoded, i/2);
3141     }else if( (zKey = sqlite3_uri_parameter(zOpen, "key"))!=0 ){
3142       sqlite3_key_v2(db, 0, zKey, sqlite3Strlen30(zKey));
3143     }
3144   }
3145 #endif
3146   sqlite3_free(zOpen);
3147   return rc & 0xff;
3148 }
3149 
3150 /*
3151 ** Open a new database handle.
3152 */
3153 int sqlite3_open(
3154   const char *zFilename,
3155   sqlite3 **ppDb
3156 ){
3157   return openDatabase(zFilename, ppDb,
3158                       SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
3159 }
3160 int sqlite3_open_v2(
3161   const char *filename,   /* Database filename (UTF-8) */
3162   sqlite3 **ppDb,         /* OUT: SQLite db handle */
3163   int flags,              /* Flags */
3164   const char *zVfs        /* Name of VFS module to use */
3165 ){
3166   return openDatabase(filename, ppDb, (unsigned int)flags, zVfs);
3167 }
3168 
3169 #ifndef SQLITE_OMIT_UTF16
3170 /*
3171 ** Open a new database handle.
3172 */
3173 int sqlite3_open16(
3174   const void *zFilename,
3175   sqlite3 **ppDb
3176 ){
3177   char const *zFilename8;   /* zFilename encoded in UTF-8 instead of UTF-16 */
3178   sqlite3_value *pVal;
3179   int rc;
3180 
3181 #ifdef SQLITE_ENABLE_API_ARMOR
3182   if( ppDb==0 ) return SQLITE_MISUSE_BKPT;
3183 #endif
3184   *ppDb = 0;
3185 #ifndef SQLITE_OMIT_AUTOINIT
3186   rc = sqlite3_initialize();
3187   if( rc ) return rc;
3188 #endif
3189   if( zFilename==0 ) zFilename = "\000\000";
3190   pVal = sqlite3ValueNew(0);
3191   sqlite3ValueSetStr(pVal, -1, zFilename, SQLITE_UTF16NATIVE, SQLITE_STATIC);
3192   zFilename8 = sqlite3ValueText(pVal, SQLITE_UTF8);
3193   if( zFilename8 ){
3194     rc = openDatabase(zFilename8, ppDb,
3195                       SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
3196     assert( *ppDb || rc==SQLITE_NOMEM );
3197     if( rc==SQLITE_OK && !DbHasProperty(*ppDb, 0, DB_SchemaLoaded) ){
3198       SCHEMA_ENC(*ppDb) = ENC(*ppDb) = SQLITE_UTF16NATIVE;
3199     }
3200   }else{
3201     rc = SQLITE_NOMEM_BKPT;
3202   }
3203   sqlite3ValueFree(pVal);
3204 
3205   return rc & 0xff;
3206 }
3207 #endif /* SQLITE_OMIT_UTF16 */
3208 
3209 /*
3210 ** Register a new collation sequence with the database handle db.
3211 */
3212 int sqlite3_create_collation(
3213   sqlite3* db,
3214   const char *zName,
3215   int enc,
3216   void* pCtx,
3217   int(*xCompare)(void*,int,const void*,int,const void*)
3218 ){
3219   return sqlite3_create_collation_v2(db, zName, enc, pCtx, xCompare, 0);
3220 }
3221 
3222 /*
3223 ** Register a new collation sequence with the database handle db.
3224 */
3225 int sqlite3_create_collation_v2(
3226   sqlite3* db,
3227   const char *zName,
3228   int enc,
3229   void* pCtx,
3230   int(*xCompare)(void*,int,const void*,int,const void*),
3231   void(*xDel)(void*)
3232 ){
3233   int rc;
3234 
3235 #ifdef SQLITE_ENABLE_API_ARMOR
3236   if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
3237 #endif
3238   sqlite3_mutex_enter(db->mutex);
3239   assert( !db->mallocFailed );
3240   rc = createCollation(db, zName, (u8)enc, pCtx, xCompare, xDel);
3241   rc = sqlite3ApiExit(db, rc);
3242   sqlite3_mutex_leave(db->mutex);
3243   return rc;
3244 }
3245 
3246 #ifndef SQLITE_OMIT_UTF16
3247 /*
3248 ** Register a new collation sequence with the database handle db.
3249 */
3250 int sqlite3_create_collation16(
3251   sqlite3* db,
3252   const void *zName,
3253   int enc,
3254   void* pCtx,
3255   int(*xCompare)(void*,int,const void*,int,const void*)
3256 ){
3257   int rc = SQLITE_OK;
3258   char *zName8;
3259 
3260 #ifdef SQLITE_ENABLE_API_ARMOR
3261   if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
3262 #endif
3263   sqlite3_mutex_enter(db->mutex);
3264   assert( !db->mallocFailed );
3265   zName8 = sqlite3Utf16to8(db, zName, -1, SQLITE_UTF16NATIVE);
3266   if( zName8 ){
3267     rc = createCollation(db, zName8, (u8)enc, pCtx, xCompare, 0);
3268     sqlite3DbFree(db, zName8);
3269   }
3270   rc = sqlite3ApiExit(db, rc);
3271   sqlite3_mutex_leave(db->mutex);
3272   return rc;
3273 }
3274 #endif /* SQLITE_OMIT_UTF16 */
3275 
3276 /*
3277 ** Register a collation sequence factory callback with the database handle
3278 ** db. Replace any previously installed collation sequence factory.
3279 */
3280 int sqlite3_collation_needed(
3281   sqlite3 *db,
3282   void *pCollNeededArg,
3283   void(*xCollNeeded)(void*,sqlite3*,int eTextRep,const char*)
3284 ){
3285 #ifdef SQLITE_ENABLE_API_ARMOR
3286   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3287 #endif
3288   sqlite3_mutex_enter(db->mutex);
3289   db->xCollNeeded = xCollNeeded;
3290   db->xCollNeeded16 = 0;
3291   db->pCollNeededArg = pCollNeededArg;
3292   sqlite3_mutex_leave(db->mutex);
3293   return SQLITE_OK;
3294 }
3295 
3296 #ifndef SQLITE_OMIT_UTF16
3297 /*
3298 ** Register a collation sequence factory callback with the database handle
3299 ** db. Replace any previously installed collation sequence factory.
3300 */
3301 int sqlite3_collation_needed16(
3302   sqlite3 *db,
3303   void *pCollNeededArg,
3304   void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*)
3305 ){
3306 #ifdef SQLITE_ENABLE_API_ARMOR
3307   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3308 #endif
3309   sqlite3_mutex_enter(db->mutex);
3310   db->xCollNeeded = 0;
3311   db->xCollNeeded16 = xCollNeeded16;
3312   db->pCollNeededArg = pCollNeededArg;
3313   sqlite3_mutex_leave(db->mutex);
3314   return SQLITE_OK;
3315 }
3316 #endif /* SQLITE_OMIT_UTF16 */
3317 
3318 #ifndef SQLITE_OMIT_DEPRECATED
3319 /*
3320 ** This function is now an anachronism. It used to be used to recover from a
3321 ** malloc() failure, but SQLite now does this automatically.
3322 */
3323 int sqlite3_global_recover(void){
3324   return SQLITE_OK;
3325 }
3326 #endif
3327 
3328 /*
3329 ** Test to see whether or not the database connection is in autocommit
3330 ** mode.  Return TRUE if it is and FALSE if not.  Autocommit mode is on
3331 ** by default.  Autocommit is disabled by a BEGIN statement and reenabled
3332 ** by the next COMMIT or ROLLBACK.
3333 */
3334 int sqlite3_get_autocommit(sqlite3 *db){
3335 #ifdef SQLITE_ENABLE_API_ARMOR
3336   if( !sqlite3SafetyCheckOk(db) ){
3337     (void)SQLITE_MISUSE_BKPT;
3338     return 0;
3339   }
3340 #endif
3341   return db->autoCommit;
3342 }
3343 
3344 /*
3345 ** The following routines are substitutes for constants SQLITE_CORRUPT,
3346 ** SQLITE_MISUSE, SQLITE_CANTOPEN, SQLITE_NOMEM and possibly other error
3347 ** constants.  They serve two purposes:
3348 **
3349 **   1.  Serve as a convenient place to set a breakpoint in a debugger
3350 **       to detect when version error conditions occurs.
3351 **
3352 **   2.  Invoke sqlite3_log() to provide the source code location where
3353 **       a low-level error is first detected.
3354 */
3355 int sqlite3ReportError(int iErr, int lineno, const char *zType){
3356   sqlite3_log(iErr, "%s at line %d of [%.10s]",
3357               zType, lineno, 20+sqlite3_sourceid());
3358   return iErr;
3359 }
3360 int sqlite3CorruptError(int lineno){
3361   testcase( sqlite3GlobalConfig.xLog!=0 );
3362   return sqlite3ReportError(SQLITE_CORRUPT, lineno, "database corruption");
3363 }
3364 int sqlite3MisuseError(int lineno){
3365   testcase( sqlite3GlobalConfig.xLog!=0 );
3366   return sqlite3ReportError(SQLITE_MISUSE, lineno, "misuse");
3367 }
3368 int sqlite3CantopenError(int lineno){
3369   testcase( sqlite3GlobalConfig.xLog!=0 );
3370   return sqlite3ReportError(SQLITE_CANTOPEN, lineno, "cannot open file");
3371 }
3372 #ifdef SQLITE_DEBUG
3373 int sqlite3CorruptPgnoError(int lineno, Pgno pgno){
3374   char zMsg[100];
3375   sqlite3_snprintf(sizeof(zMsg), zMsg, "database corruption page %d", pgno);
3376   testcase( sqlite3GlobalConfig.xLog!=0 );
3377   return sqlite3ReportError(SQLITE_CORRUPT, lineno, zMsg);
3378 }
3379 int sqlite3NomemError(int lineno){
3380   testcase( sqlite3GlobalConfig.xLog!=0 );
3381   return sqlite3ReportError(SQLITE_NOMEM, lineno, "OOM");
3382 }
3383 int sqlite3IoerrnomemError(int lineno){
3384   testcase( sqlite3GlobalConfig.xLog!=0 );
3385   return sqlite3ReportError(SQLITE_IOERR_NOMEM, lineno, "I/O OOM error");
3386 }
3387 #endif
3388 
3389 #ifndef SQLITE_OMIT_DEPRECATED
3390 /*
3391 ** This is a convenience routine that makes sure that all thread-specific
3392 ** data for this thread has been deallocated.
3393 **
3394 ** SQLite no longer uses thread-specific data so this routine is now a
3395 ** no-op.  It is retained for historical compatibility.
3396 */
3397 void sqlite3_thread_cleanup(void){
3398 }
3399 #endif
3400 
3401 /*
3402 ** Return meta information about a specific column of a database table.
3403 ** See comment in sqlite3.h (sqlite.h.in) for details.
3404 */
3405 int sqlite3_table_column_metadata(
3406   sqlite3 *db,                /* Connection handle */
3407   const char *zDbName,        /* Database name or NULL */
3408   const char *zTableName,     /* Table name */
3409   const char *zColumnName,    /* Column name */
3410   char const **pzDataType,    /* OUTPUT: Declared data type */
3411   char const **pzCollSeq,     /* OUTPUT: Collation sequence name */
3412   int *pNotNull,              /* OUTPUT: True if NOT NULL constraint exists */
3413   int *pPrimaryKey,           /* OUTPUT: True if column part of PK */
3414   int *pAutoinc               /* OUTPUT: True if column is auto-increment */
3415 ){
3416   int rc;
3417   char *zErrMsg = 0;
3418   Table *pTab = 0;
3419   Column *pCol = 0;
3420   int iCol = 0;
3421   char const *zDataType = 0;
3422   char const *zCollSeq = 0;
3423   int notnull = 0;
3424   int primarykey = 0;
3425   int autoinc = 0;
3426 
3427 
3428 #ifdef SQLITE_ENABLE_API_ARMOR
3429   if( !sqlite3SafetyCheckOk(db) || zTableName==0 ){
3430     return SQLITE_MISUSE_BKPT;
3431   }
3432 #endif
3433 
3434   /* Ensure the database schema has been loaded */
3435   sqlite3_mutex_enter(db->mutex);
3436   sqlite3BtreeEnterAll(db);
3437   rc = sqlite3Init(db, &zErrMsg);
3438   if( SQLITE_OK!=rc ){
3439     goto error_out;
3440   }
3441 
3442   /* Locate the table in question */
3443   pTab = sqlite3FindTable(db, zTableName, zDbName);
3444   if( !pTab || pTab->pSelect ){
3445     pTab = 0;
3446     goto error_out;
3447   }
3448 
3449   /* Find the column for which info is requested */
3450   if( zColumnName==0 ){
3451     /* Query for existance of table only */
3452   }else{
3453     for(iCol=0; iCol<pTab->nCol; iCol++){
3454       pCol = &pTab->aCol[iCol];
3455       if( 0==sqlite3StrICmp(pCol->zName, zColumnName) ){
3456         break;
3457       }
3458     }
3459     if( iCol==pTab->nCol ){
3460       if( HasRowid(pTab) && sqlite3IsRowid(zColumnName) ){
3461         iCol = pTab->iPKey;
3462         pCol = iCol>=0 ? &pTab->aCol[iCol] : 0;
3463       }else{
3464         pTab = 0;
3465         goto error_out;
3466       }
3467     }
3468   }
3469 
3470   /* The following block stores the meta information that will be returned
3471   ** to the caller in local variables zDataType, zCollSeq, notnull, primarykey
3472   ** and autoinc. At this point there are two possibilities:
3473   **
3474   **     1. The specified column name was rowid", "oid" or "_rowid_"
3475   **        and there is no explicitly declared IPK column.
3476   **
3477   **     2. The table is not a view and the column name identified an
3478   **        explicitly declared column. Copy meta information from *pCol.
3479   */
3480   if( pCol ){
3481     zDataType = sqlite3ColumnType(pCol,0);
3482     zCollSeq = pCol->zColl;
3483     notnull = pCol->notNull!=0;
3484     primarykey  = (pCol->colFlags & COLFLAG_PRIMKEY)!=0;
3485     autoinc = pTab->iPKey==iCol && (pTab->tabFlags & TF_Autoincrement)!=0;
3486   }else{
3487     zDataType = "INTEGER";
3488     primarykey = 1;
3489   }
3490   if( !zCollSeq ){
3491     zCollSeq = sqlite3StrBINARY;
3492   }
3493 
3494 error_out:
3495   sqlite3BtreeLeaveAll(db);
3496 
3497   /* Whether the function call succeeded or failed, set the output parameters
3498   ** to whatever their local counterparts contain. If an error did occur,
3499   ** this has the effect of zeroing all output parameters.
3500   */
3501   if( pzDataType ) *pzDataType = zDataType;
3502   if( pzCollSeq ) *pzCollSeq = zCollSeq;
3503   if( pNotNull ) *pNotNull = notnull;
3504   if( pPrimaryKey ) *pPrimaryKey = primarykey;
3505   if( pAutoinc ) *pAutoinc = autoinc;
3506 
3507   if( SQLITE_OK==rc && !pTab ){
3508     sqlite3DbFree(db, zErrMsg);
3509     zErrMsg = sqlite3MPrintf(db, "no such table column: %s.%s", zTableName,
3510         zColumnName);
3511     rc = SQLITE_ERROR;
3512   }
3513   sqlite3ErrorWithMsg(db, rc, (zErrMsg?"%s":0), zErrMsg);
3514   sqlite3DbFree(db, zErrMsg);
3515   rc = sqlite3ApiExit(db, rc);
3516   sqlite3_mutex_leave(db->mutex);
3517   return rc;
3518 }
3519 
3520 /*
3521 ** Sleep for a little while.  Return the amount of time slept.
3522 */
3523 int sqlite3_sleep(int ms){
3524   sqlite3_vfs *pVfs;
3525   int rc;
3526   pVfs = sqlite3_vfs_find(0);
3527   if( pVfs==0 ) return 0;
3528 
3529   /* This function works in milliseconds, but the underlying OsSleep()
3530   ** API uses microseconds. Hence the 1000's.
3531   */
3532   rc = (sqlite3OsSleep(pVfs, 1000*ms)/1000);
3533   return rc;
3534 }
3535 
3536 /*
3537 ** Enable or disable the extended result codes.
3538 */
3539 int sqlite3_extended_result_codes(sqlite3 *db, int onoff){
3540 #ifdef SQLITE_ENABLE_API_ARMOR
3541   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3542 #endif
3543   sqlite3_mutex_enter(db->mutex);
3544   db->errMask = onoff ? 0xffffffff : 0xff;
3545   sqlite3_mutex_leave(db->mutex);
3546   return SQLITE_OK;
3547 }
3548 
3549 /*
3550 ** Invoke the xFileControl method on a particular database.
3551 */
3552 int sqlite3_file_control(sqlite3 *db, const char *zDbName, int op, void *pArg){
3553   int rc = SQLITE_ERROR;
3554   Btree *pBtree;
3555 
3556 #ifdef SQLITE_ENABLE_API_ARMOR
3557   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3558 #endif
3559   sqlite3_mutex_enter(db->mutex);
3560   pBtree = sqlite3DbNameToBtree(db, zDbName);
3561   if( pBtree ){
3562     Pager *pPager;
3563     sqlite3_file *fd;
3564     sqlite3BtreeEnter(pBtree);
3565     pPager = sqlite3BtreePager(pBtree);
3566     assert( pPager!=0 );
3567     fd = sqlite3PagerFile(pPager);
3568     assert( fd!=0 );
3569     if( op==SQLITE_FCNTL_FILE_POINTER ){
3570       *(sqlite3_file**)pArg = fd;
3571       rc = SQLITE_OK;
3572     }else if( op==SQLITE_FCNTL_VFS_POINTER ){
3573       *(sqlite3_vfs**)pArg = sqlite3PagerVfs(pPager);
3574       rc = SQLITE_OK;
3575     }else if( op==SQLITE_FCNTL_JOURNAL_POINTER ){
3576       *(sqlite3_file**)pArg = sqlite3PagerJrnlFile(pPager);
3577       rc = SQLITE_OK;
3578     }else if( fd->pMethods ){
3579       rc = sqlite3OsFileControl(fd, op, pArg);
3580     }else{
3581       rc = SQLITE_NOTFOUND;
3582     }
3583     sqlite3BtreeLeave(pBtree);
3584   }
3585   sqlite3_mutex_leave(db->mutex);
3586   return rc;
3587 }
3588 
3589 /*
3590 ** Interface to the testing logic.
3591 */
3592 int sqlite3_test_control(int op, ...){
3593   int rc = 0;
3594 #ifdef SQLITE_UNTESTABLE
3595   UNUSED_PARAMETER(op);
3596 #else
3597   va_list ap;
3598   va_start(ap, op);
3599   switch( op ){
3600 
3601     /*
3602     ** Save the current state of the PRNG.
3603     */
3604     case SQLITE_TESTCTRL_PRNG_SAVE: {
3605       sqlite3PrngSaveState();
3606       break;
3607     }
3608 
3609     /*
3610     ** Restore the state of the PRNG to the last state saved using
3611     ** PRNG_SAVE.  If PRNG_SAVE has never before been called, then
3612     ** this verb acts like PRNG_RESET.
3613     */
3614     case SQLITE_TESTCTRL_PRNG_RESTORE: {
3615       sqlite3PrngRestoreState();
3616       break;
3617     }
3618 
3619     /*
3620     ** Reset the PRNG back to its uninitialized state.  The next call
3621     ** to sqlite3_randomness() will reseed the PRNG using a single call
3622     ** to the xRandomness method of the default VFS.
3623     */
3624     case SQLITE_TESTCTRL_PRNG_RESET: {
3625       sqlite3_randomness(0,0);
3626       break;
3627     }
3628 
3629     /*
3630     **  sqlite3_test_control(BITVEC_TEST, size, program)
3631     **
3632     ** Run a test against a Bitvec object of size.  The program argument
3633     ** is an array of integers that defines the test.  Return -1 on a
3634     ** memory allocation error, 0 on success, or non-zero for an error.
3635     ** See the sqlite3BitvecBuiltinTest() for additional information.
3636     */
3637     case SQLITE_TESTCTRL_BITVEC_TEST: {
3638       int sz = va_arg(ap, int);
3639       int *aProg = va_arg(ap, int*);
3640       rc = sqlite3BitvecBuiltinTest(sz, aProg);
3641       break;
3642     }
3643 
3644     /*
3645     **  sqlite3_test_control(FAULT_INSTALL, xCallback)
3646     **
3647     ** Arrange to invoke xCallback() whenever sqlite3FaultSim() is called,
3648     ** if xCallback is not NULL.
3649     **
3650     ** As a test of the fault simulator mechanism itself, sqlite3FaultSim(0)
3651     ** is called immediately after installing the new callback and the return
3652     ** value from sqlite3FaultSim(0) becomes the return from
3653     ** sqlite3_test_control().
3654     */
3655     case SQLITE_TESTCTRL_FAULT_INSTALL: {
3656       /* MSVC is picky about pulling func ptrs from va lists.
3657       ** http://support.microsoft.com/kb/47961
3658       ** sqlite3GlobalConfig.xTestCallback = va_arg(ap, int(*)(int));
3659       */
3660       typedef int(*TESTCALLBACKFUNC_t)(int);
3661       sqlite3GlobalConfig.xTestCallback = va_arg(ap, TESTCALLBACKFUNC_t);
3662       rc = sqlite3FaultSim(0);
3663       break;
3664     }
3665 
3666     /*
3667     **  sqlite3_test_control(BENIGN_MALLOC_HOOKS, xBegin, xEnd)
3668     **
3669     ** Register hooks to call to indicate which malloc() failures
3670     ** are benign.
3671     */
3672     case SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS: {
3673       typedef void (*void_function)(void);
3674       void_function xBenignBegin;
3675       void_function xBenignEnd;
3676       xBenignBegin = va_arg(ap, void_function);
3677       xBenignEnd = va_arg(ap, void_function);
3678       sqlite3BenignMallocHooks(xBenignBegin, xBenignEnd);
3679       break;
3680     }
3681 
3682     /*
3683     **  sqlite3_test_control(SQLITE_TESTCTRL_PENDING_BYTE, unsigned int X)
3684     **
3685     ** Set the PENDING byte to the value in the argument, if X>0.
3686     ** Make no changes if X==0.  Return the value of the pending byte
3687     ** as it existing before this routine was called.
3688     **
3689     ** IMPORTANT:  Changing the PENDING byte from 0x40000000 results in
3690     ** an incompatible database file format.  Changing the PENDING byte
3691     ** while any database connection is open results in undefined and
3692     ** deleterious behavior.
3693     */
3694     case SQLITE_TESTCTRL_PENDING_BYTE: {
3695       rc = PENDING_BYTE;
3696 #ifndef SQLITE_OMIT_WSD
3697       {
3698         unsigned int newVal = va_arg(ap, unsigned int);
3699         if( newVal ) sqlite3PendingByte = newVal;
3700       }
3701 #endif
3702       break;
3703     }
3704 
3705     /*
3706     **  sqlite3_test_control(SQLITE_TESTCTRL_ASSERT, int X)
3707     **
3708     ** This action provides a run-time test to see whether or not
3709     ** assert() was enabled at compile-time.  If X is true and assert()
3710     ** is enabled, then the return value is true.  If X is true and
3711     ** assert() is disabled, then the return value is zero.  If X is
3712     ** false and assert() is enabled, then the assertion fires and the
3713     ** process aborts.  If X is false and assert() is disabled, then the
3714     ** return value is zero.
3715     */
3716     case SQLITE_TESTCTRL_ASSERT: {
3717       volatile int x = 0;
3718       assert( /*side-effects-ok*/ (x = va_arg(ap,int))!=0 );
3719       rc = x;
3720       break;
3721     }
3722 
3723 
3724     /*
3725     **  sqlite3_test_control(SQLITE_TESTCTRL_ALWAYS, int X)
3726     **
3727     ** This action provides a run-time test to see how the ALWAYS and
3728     ** NEVER macros were defined at compile-time.
3729     **
3730     ** The return value is ALWAYS(X) if X is true, or 0 if X is false.
3731     **
3732     ** The recommended test is X==2.  If the return value is 2, that means
3733     ** ALWAYS() and NEVER() are both no-op pass-through macros, which is the
3734     ** default setting.  If the return value is 1, then ALWAYS() is either
3735     ** hard-coded to true or else it asserts if its argument is false.
3736     ** The first behavior (hard-coded to true) is the case if
3737     ** SQLITE_TESTCTRL_ASSERT shows that assert() is disabled and the second
3738     ** behavior (assert if the argument to ALWAYS() is false) is the case if
3739     ** SQLITE_TESTCTRL_ASSERT shows that assert() is enabled.
3740     **
3741     ** The run-time test procedure might look something like this:
3742     **
3743     **    if( sqlite3_test_control(SQLITE_TESTCTRL_ALWAYS, 2)==2 ){
3744     **      // ALWAYS() and NEVER() are no-op pass-through macros
3745     **    }else if( sqlite3_test_control(SQLITE_TESTCTRL_ASSERT, 1) ){
3746     **      // ALWAYS(x) asserts that x is true. NEVER(x) asserts x is false.
3747     **    }else{
3748     **      // ALWAYS(x) is a constant 1.  NEVER(x) is a constant 0.
3749     **    }
3750     */
3751     case SQLITE_TESTCTRL_ALWAYS: {
3752       int x = va_arg(ap,int);
3753       rc = x ? ALWAYS(x) : 0;
3754       break;
3755     }
3756 
3757     /*
3758     **   sqlite3_test_control(SQLITE_TESTCTRL_BYTEORDER);
3759     **
3760     ** The integer returned reveals the byte-order of the computer on which
3761     ** SQLite is running:
3762     **
3763     **       1     big-endian,    determined at run-time
3764     **      10     little-endian, determined at run-time
3765     **  432101     big-endian,    determined at compile-time
3766     **  123410     little-endian, determined at compile-time
3767     */
3768     case SQLITE_TESTCTRL_BYTEORDER: {
3769       rc = SQLITE_BYTEORDER*100 + SQLITE_LITTLEENDIAN*10 + SQLITE_BIGENDIAN;
3770       break;
3771     }
3772 
3773     /*   sqlite3_test_control(SQLITE_TESTCTRL_RESERVE, sqlite3 *db, int N)
3774     **
3775     ** Set the nReserve size to N for the main database on the database
3776     ** connection db.
3777     */
3778     case SQLITE_TESTCTRL_RESERVE: {
3779       sqlite3 *db = va_arg(ap, sqlite3*);
3780       int x = va_arg(ap,int);
3781       sqlite3_mutex_enter(db->mutex);
3782       sqlite3BtreeSetPageSize(db->aDb[0].pBt, 0, x, 0);
3783       sqlite3_mutex_leave(db->mutex);
3784       break;
3785     }
3786 
3787     /*  sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS, sqlite3 *db, int N)
3788     **
3789     ** Enable or disable various optimizations for testing purposes.  The
3790     ** argument N is a bitmask of optimizations to be disabled.  For normal
3791     ** operation N should be 0.  The idea is that a test program (like the
3792     ** SQL Logic Test or SLT test module) can run the same SQL multiple times
3793     ** with various optimizations disabled to verify that the same answer
3794     ** is obtained in every case.
3795     */
3796     case SQLITE_TESTCTRL_OPTIMIZATIONS: {
3797       sqlite3 *db = va_arg(ap, sqlite3*);
3798       db->dbOptFlags = (u16)(va_arg(ap, int) & 0xffff);
3799       break;
3800     }
3801 
3802 #ifdef SQLITE_N_KEYWORD
3803     /* sqlite3_test_control(SQLITE_TESTCTRL_ISKEYWORD, const char *zWord)
3804     **
3805     ** If zWord is a keyword recognized by the parser, then return the
3806     ** number of keywords.  Or if zWord is not a keyword, return 0.
3807     **
3808     ** This test feature is only available in the amalgamation since
3809     ** the SQLITE_N_KEYWORD macro is not defined in this file if SQLite
3810     ** is built using separate source files.
3811     */
3812     case SQLITE_TESTCTRL_ISKEYWORD: {
3813       const char *zWord = va_arg(ap, const char*);
3814       int n = sqlite3Strlen30(zWord);
3815       rc = (sqlite3KeywordCode((u8*)zWord, n)!=TK_ID) ? SQLITE_N_KEYWORD : 0;
3816       break;
3817     }
3818 #endif
3819 
3820     /*   sqlite3_test_control(SQLITE_TESTCTRL_LOCALTIME_FAULT, int onoff);
3821     **
3822     ** If parameter onoff is non-zero, configure the wrappers so that all
3823     ** subsequent calls to localtime() and variants fail. If onoff is zero,
3824     ** undo this setting.
3825     */
3826     case SQLITE_TESTCTRL_LOCALTIME_FAULT: {
3827       sqlite3GlobalConfig.bLocaltimeFault = va_arg(ap, int);
3828       break;
3829     }
3830 
3831     /*   sqlite3_test_control(SQLITE_TESTCTRL_NEVER_CORRUPT, int);
3832     **
3833     ** Set or clear a flag that indicates that the database file is always well-
3834     ** formed and never corrupt.  This flag is clear by default, indicating that
3835     ** database files might have arbitrary corruption.  Setting the flag during
3836     ** testing causes certain assert() statements in the code to be activated
3837     ** that demonstrat invariants on well-formed database files.
3838     */
3839     case SQLITE_TESTCTRL_NEVER_CORRUPT: {
3840       sqlite3GlobalConfig.neverCorrupt = va_arg(ap, int);
3841       break;
3842     }
3843 
3844     /* Set the threshold at which OP_Once counters reset back to zero.
3845     ** By default this is 0x7ffffffe (over 2 billion), but that value is
3846     ** too big to test in a reasonable amount of time, so this control is
3847     ** provided to set a small and easily reachable reset value.
3848     */
3849     case SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD: {
3850       sqlite3GlobalConfig.iOnceResetThreshold = va_arg(ap, int);
3851       break;
3852     }
3853 
3854     /*   sqlite3_test_control(SQLITE_TESTCTRL_VDBE_COVERAGE, xCallback, ptr);
3855     **
3856     ** Set the VDBE coverage callback function to xCallback with context
3857     ** pointer ptr.
3858     */
3859     case SQLITE_TESTCTRL_VDBE_COVERAGE: {
3860 #ifdef SQLITE_VDBE_COVERAGE
3861       typedef void (*branch_callback)(void*,int,u8,u8);
3862       sqlite3GlobalConfig.xVdbeBranch = va_arg(ap,branch_callback);
3863       sqlite3GlobalConfig.pVdbeBranchArg = va_arg(ap,void*);
3864 #endif
3865       break;
3866     }
3867 
3868     /*   sqlite3_test_control(SQLITE_TESTCTRL_SORTER_MMAP, db, nMax); */
3869     case SQLITE_TESTCTRL_SORTER_MMAP: {
3870       sqlite3 *db = va_arg(ap, sqlite3*);
3871       db->nMaxSorterMmap = va_arg(ap, int);
3872       break;
3873     }
3874 
3875     /*   sqlite3_test_control(SQLITE_TESTCTRL_ISINIT);
3876     **
3877     ** Return SQLITE_OK if SQLite has been initialized and SQLITE_ERROR if
3878     ** not.
3879     */
3880     case SQLITE_TESTCTRL_ISINIT: {
3881       if( sqlite3GlobalConfig.isInit==0 ) rc = SQLITE_ERROR;
3882       break;
3883     }
3884 
3885     /*  sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, db, dbName, onOff, tnum);
3886     **
3887     ** This test control is used to create imposter tables.  "db" is a pointer
3888     ** to the database connection.  dbName is the database name (ex: "main" or
3889     ** "temp") which will receive the imposter.  "onOff" turns imposter mode on
3890     ** or off.  "tnum" is the root page of the b-tree to which the imposter
3891     ** table should connect.
3892     **
3893     ** Enable imposter mode only when the schema has already been parsed.  Then
3894     ** run a single CREATE TABLE statement to construct the imposter table in
3895     ** the parsed schema.  Then turn imposter mode back off again.
3896     **
3897     ** If onOff==0 and tnum>0 then reset the schema for all databases, causing
3898     ** the schema to be reparsed the next time it is needed.  This has the
3899     ** effect of erasing all imposter tables.
3900     */
3901     case SQLITE_TESTCTRL_IMPOSTER: {
3902       sqlite3 *db = va_arg(ap, sqlite3*);
3903       sqlite3_mutex_enter(db->mutex);
3904       db->init.iDb = sqlite3FindDbName(db, va_arg(ap,const char*));
3905       db->init.busy = db->init.imposterTable = va_arg(ap,int);
3906       db->init.newTnum = va_arg(ap,int);
3907       if( db->init.busy==0 && db->init.newTnum>0 ){
3908         sqlite3ResetAllSchemasOfConnection(db);
3909       }
3910       sqlite3_mutex_leave(db->mutex);
3911       break;
3912     }
3913   }
3914   va_end(ap);
3915 #endif /* SQLITE_UNTESTABLE */
3916   return rc;
3917 }
3918 
3919 /*
3920 ** This is a utility routine, useful to VFS implementations, that checks
3921 ** to see if a database file was a URI that contained a specific query
3922 ** parameter, and if so obtains the value of the query parameter.
3923 **
3924 ** The zFilename argument is the filename pointer passed into the xOpen()
3925 ** method of a VFS implementation.  The zParam argument is the name of the
3926 ** query parameter we seek.  This routine returns the value of the zParam
3927 ** parameter if it exists.  If the parameter does not exist, this routine
3928 ** returns a NULL pointer.
3929 */
3930 const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam){
3931   if( zFilename==0 || zParam==0 ) return 0;
3932   zFilename += sqlite3Strlen30(zFilename) + 1;
3933   while( zFilename[0] ){
3934     int x = strcmp(zFilename, zParam);
3935     zFilename += sqlite3Strlen30(zFilename) + 1;
3936     if( x==0 ) return zFilename;
3937     zFilename += sqlite3Strlen30(zFilename) + 1;
3938   }
3939   return 0;
3940 }
3941 
3942 /*
3943 ** Return a boolean value for a query parameter.
3944 */
3945 int sqlite3_uri_boolean(const char *zFilename, const char *zParam, int bDflt){
3946   const char *z = sqlite3_uri_parameter(zFilename, zParam);
3947   bDflt = bDflt!=0;
3948   return z ? sqlite3GetBoolean(z, bDflt) : bDflt;
3949 }
3950 
3951 /*
3952 ** Return a 64-bit integer value for a query parameter.
3953 */
3954 sqlite3_int64 sqlite3_uri_int64(
3955   const char *zFilename,    /* Filename as passed to xOpen */
3956   const char *zParam,       /* URI parameter sought */
3957   sqlite3_int64 bDflt       /* return if parameter is missing */
3958 ){
3959   const char *z = sqlite3_uri_parameter(zFilename, zParam);
3960   sqlite3_int64 v;
3961   if( z && sqlite3DecOrHexToI64(z, &v)==0 ){
3962     bDflt = v;
3963   }
3964   return bDflt;
3965 }
3966 
3967 /*
3968 ** Return the Btree pointer identified by zDbName.  Return NULL if not found.
3969 */
3970 Btree *sqlite3DbNameToBtree(sqlite3 *db, const char *zDbName){
3971   int iDb = zDbName ? sqlite3FindDbName(db, zDbName) : 0;
3972   return iDb<0 ? 0 : db->aDb[iDb].pBt;
3973 }
3974 
3975 /*
3976 ** Return the filename of the database associated with a database
3977 ** connection.
3978 */
3979 const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName){
3980   Btree *pBt;
3981 #ifdef SQLITE_ENABLE_API_ARMOR
3982   if( !sqlite3SafetyCheckOk(db) ){
3983     (void)SQLITE_MISUSE_BKPT;
3984     return 0;
3985   }
3986 #endif
3987   pBt = sqlite3DbNameToBtree(db, zDbName);
3988   return pBt ? sqlite3BtreeGetFilename(pBt) : 0;
3989 }
3990 
3991 /*
3992 ** Return 1 if database is read-only or 0 if read/write.  Return -1 if
3993 ** no such database exists.
3994 */
3995 int sqlite3_db_readonly(sqlite3 *db, const char *zDbName){
3996   Btree *pBt;
3997 #ifdef SQLITE_ENABLE_API_ARMOR
3998   if( !sqlite3SafetyCheckOk(db) ){
3999     (void)SQLITE_MISUSE_BKPT;
4000     return -1;
4001   }
4002 #endif
4003   pBt = sqlite3DbNameToBtree(db, zDbName);
4004   return pBt ? sqlite3BtreeIsReadonly(pBt) : -1;
4005 }
4006 
4007 #ifdef SQLITE_ENABLE_SNAPSHOT
4008 /*
4009 ** Obtain a snapshot handle for the snapshot of database zDb currently
4010 ** being read by handle db.
4011 */
4012 int sqlite3_snapshot_get(
4013   sqlite3 *db,
4014   const char *zDb,
4015   sqlite3_snapshot **ppSnapshot
4016 ){
4017   int rc = SQLITE_ERROR;
4018 #ifndef SQLITE_OMIT_WAL
4019 
4020 #ifdef SQLITE_ENABLE_API_ARMOR
4021   if( !sqlite3SafetyCheckOk(db) ){
4022     return SQLITE_MISUSE_BKPT;
4023   }
4024 #endif
4025   sqlite3_mutex_enter(db->mutex);
4026 
4027   if( db->autoCommit==0 ){
4028     int iDb = sqlite3FindDbName(db, zDb);
4029     if( iDb==0 || iDb>1 ){
4030       Btree *pBt = db->aDb[iDb].pBt;
4031       if( 0==sqlite3BtreeIsInTrans(pBt) ){
4032         rc = sqlite3BtreeBeginTrans(pBt, 0);
4033         if( rc==SQLITE_OK ){
4034           rc = sqlite3PagerSnapshotGet(sqlite3BtreePager(pBt), ppSnapshot);
4035         }
4036       }
4037     }
4038   }
4039 
4040   sqlite3_mutex_leave(db->mutex);
4041 #endif   /* SQLITE_OMIT_WAL */
4042   return rc;
4043 }
4044 
4045 /*
4046 ** Open a read-transaction on the snapshot idendified by pSnapshot.
4047 */
4048 int sqlite3_snapshot_open(
4049   sqlite3 *db,
4050   const char *zDb,
4051   sqlite3_snapshot *pSnapshot
4052 ){
4053   int rc = SQLITE_ERROR;
4054 #ifndef SQLITE_OMIT_WAL
4055 
4056 #ifdef SQLITE_ENABLE_API_ARMOR
4057   if( !sqlite3SafetyCheckOk(db) ){
4058     return SQLITE_MISUSE_BKPT;
4059   }
4060 #endif
4061   sqlite3_mutex_enter(db->mutex);
4062   if( db->autoCommit==0 ){
4063     int iDb;
4064     iDb = sqlite3FindDbName(db, zDb);
4065     if( iDb==0 || iDb>1 ){
4066       Btree *pBt = db->aDb[iDb].pBt;
4067       if( 0==sqlite3BtreeIsInReadTrans(pBt) ){
4068         rc = sqlite3PagerSnapshotOpen(sqlite3BtreePager(pBt), pSnapshot);
4069         if( rc==SQLITE_OK ){
4070           rc = sqlite3BtreeBeginTrans(pBt, 0);
4071           sqlite3PagerSnapshotOpen(sqlite3BtreePager(pBt), 0);
4072         }
4073       }
4074     }
4075   }
4076 
4077   sqlite3_mutex_leave(db->mutex);
4078 #endif   /* SQLITE_OMIT_WAL */
4079   return rc;
4080 }
4081 
4082 /*
4083 ** Recover as many snapshots as possible from the wal file associated with
4084 ** schema zDb of database db.
4085 */
4086 int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb){
4087   int rc = SQLITE_ERROR;
4088   int iDb;
4089 #ifndef SQLITE_OMIT_WAL
4090 
4091 #ifdef SQLITE_ENABLE_API_ARMOR
4092   if( !sqlite3SafetyCheckOk(db) ){
4093     return SQLITE_MISUSE_BKPT;
4094   }
4095 #endif
4096 
4097   sqlite3_mutex_enter(db->mutex);
4098   iDb = sqlite3FindDbName(db, zDb);
4099   if( iDb==0 || iDb>1 ){
4100     Btree *pBt = db->aDb[iDb].pBt;
4101     if( 0==sqlite3BtreeIsInReadTrans(pBt) ){
4102       rc = sqlite3BtreeBeginTrans(pBt, 0);
4103       if( rc==SQLITE_OK ){
4104         rc = sqlite3PagerSnapshotRecover(sqlite3BtreePager(pBt));
4105         sqlite3BtreeCommit(pBt);
4106       }
4107     }
4108   }
4109   sqlite3_mutex_leave(db->mutex);
4110 #endif   /* SQLITE_OMIT_WAL */
4111   return rc;
4112 }
4113 
4114 /*
4115 ** Free a snapshot handle obtained from sqlite3_snapshot_get().
4116 */
4117 void sqlite3_snapshot_free(sqlite3_snapshot *pSnapshot){
4118   sqlite3_free(pSnapshot);
4119 }
4120 #endif /* SQLITE_ENABLE_SNAPSHOT */
4121 
4122 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
4123 /*
4124 ** Given the name of a compile-time option, return true if that option
4125 ** was used and false if not.
4126 **
4127 ** The name can optionally begin with "SQLITE_" but the "SQLITE_" prefix
4128 ** is not required for a match.
4129 */
4130 int sqlite3_compileoption_used(const char *zOptName){
4131   int i, n;
4132   int nOpt;
4133   const char **azCompileOpt;
4134 
4135 #if SQLITE_ENABLE_API_ARMOR
4136   if( zOptName==0 ){
4137     (void)SQLITE_MISUSE_BKPT;
4138     return 0;
4139   }
4140 #endif
4141 
4142   azCompileOpt = sqlite3CompileOptions(&nOpt);
4143 
4144   if( sqlite3StrNICmp(zOptName, "SQLITE_", 7)==0 ) zOptName += 7;
4145   n = sqlite3Strlen30(zOptName);
4146 
4147   /* Since nOpt is normally in single digits, a linear search is
4148   ** adequate. No need for a binary search. */
4149   for(i=0; i<nOpt; i++){
4150     if( sqlite3StrNICmp(zOptName, azCompileOpt[i], n)==0
4151      && sqlite3IsIdChar((unsigned char)azCompileOpt[i][n])==0
4152     ){
4153       return 1;
4154     }
4155   }
4156   return 0;
4157 }
4158 
4159 /*
4160 ** Return the N-th compile-time option string.  If N is out of range,
4161 ** return a NULL pointer.
4162 */
4163 const char *sqlite3_compileoption_get(int N){
4164   int nOpt;
4165   const char **azCompileOpt;
4166   azCompileOpt = sqlite3CompileOptions(&nOpt);
4167   if( N>=0 && N<nOpt ){
4168     return azCompileOpt[N];
4169   }
4170   return 0;
4171 }
4172 #endif /* SQLITE_OMIT_COMPILEOPTION_DIAGS */
4173