xref: /sqlite-3.40.0/src/main.c (revision a8e41eca)
1 /*
2 ** 2001 September 15
3 **
4 ** The author disclaims copyright to this source code.  In place of
5 ** a legal notice, here is a blessing:
6 **
7 **    May you do good and not evil.
8 **    May you find forgiveness for yourself and forgive others.
9 **    May you share freely, never taking more than you give.
10 **
11 *************************************************************************
12 ** Main file for the SQLite library.  The routines in this file
13 ** implement the programmer interface to the library.  Routines in
14 ** other files are for internal use by SQLite and should not be
15 ** accessed by users of the library.
16 */
17 #include "sqliteInt.h"
18 
19 #ifdef SQLITE_ENABLE_FTS3
20 # include "fts3.h"
21 #endif
22 #ifdef SQLITE_ENABLE_RTREE
23 # include "rtree.h"
24 #endif
25 #if defined(SQLITE_ENABLE_ICU) || defined(SQLITE_ENABLE_ICU_COLLATIONS)
26 # include "sqliteicu.h"
27 #endif
28 
29 /*
30 ** This is an extension initializer that is a no-op and always
31 ** succeeds, except that it fails if the fault-simulation is set
32 ** to 500.
33 */
34 static int sqlite3TestExtInit(sqlite3 *db){
35   (void)db;
36   return sqlite3FaultSim(500);
37 }
38 
39 
40 /*
41 ** Forward declarations of external module initializer functions
42 ** for modules that need them.
43 */
44 #ifdef SQLITE_ENABLE_FTS1
45 int sqlite3Fts1Init(sqlite3*);
46 #endif
47 #ifdef SQLITE_ENABLE_FTS2
48 int sqlite3Fts2Init(sqlite3*);
49 #endif
50 #ifdef SQLITE_ENABLE_FTS5
51 int sqlite3Fts5Init(sqlite3*);
52 #endif
53 #ifdef SQLITE_ENABLE_JSON1
54 int sqlite3Json1Init(sqlite3*);
55 #endif
56 #ifdef SQLITE_ENABLE_STMTVTAB
57 int sqlite3StmtVtabInit(sqlite3*);
58 #endif
59 
60 /*
61 ** An array of pointers to extension initializer functions for
62 ** built-in extensions.
63 */
64 static int (*const sqlite3BuiltinExtensions[])(sqlite3*) = {
65 #ifdef SQLITE_ENABLE_FTS1
66   sqlite3Fts1Init,
67 #endif
68 #ifdef SQLITE_ENABLE_FTS2
69   sqlite3Fts2Init,
70 #endif
71 #ifdef SQLITE_ENABLE_FTS3
72   sqlite3Fts3Init,
73 #endif
74 #ifdef SQLITE_ENABLE_FTS5
75   sqlite3Fts5Init,
76 #endif
77 #if defined(SQLITE_ENABLE_ICU) || defined(SQLITE_ENABLE_ICU_COLLATIONS)
78   sqlite3IcuInit,
79 #endif
80 #ifdef SQLITE_ENABLE_RTREE
81   sqlite3RtreeInit,
82 #endif
83 #ifdef SQLITE_ENABLE_DBPAGE_VTAB
84   sqlite3DbpageRegister,
85 #endif
86 #ifdef SQLITE_ENABLE_DBSTAT_VTAB
87   sqlite3DbstatRegister,
88 #endif
89   sqlite3TestExtInit,
90 #ifdef SQLITE_ENABLE_JSON1
91   sqlite3Json1Init,
92 #endif
93 #ifdef SQLITE_ENABLE_STMTVTAB
94   sqlite3StmtVtabInit,
95 #endif
96 #ifdef SQLITE_ENABLE_BYTECODE_VTAB
97   sqlite3VdbeBytecodeVtabInit,
98 #endif
99 };
100 
101 #ifndef SQLITE_AMALGAMATION
102 /* IMPLEMENTATION-OF: R-46656-45156 The sqlite3_version[] string constant
103 ** contains the text of SQLITE_VERSION macro.
104 */
105 const char sqlite3_version[] = SQLITE_VERSION;
106 #endif
107 
108 /* IMPLEMENTATION-OF: R-53536-42575 The sqlite3_libversion() function returns
109 ** a pointer to the to the sqlite3_version[] string constant.
110 */
111 const char *sqlite3_libversion(void){ return sqlite3_version; }
112 
113 /* IMPLEMENTATION-OF: R-25063-23286 The sqlite3_sourceid() function returns a
114 ** pointer to a string constant whose value is the same as the
115 ** SQLITE_SOURCE_ID C preprocessor macro. Except if SQLite is built using
116 ** an edited copy of the amalgamation, then the last four characters of
117 ** the hash might be different from SQLITE_SOURCE_ID.
118 */
119 const char *sqlite3_sourceid(void){ return SQLITE_SOURCE_ID; }
120 
121 /* IMPLEMENTATION-OF: R-35210-63508 The sqlite3_libversion_number() function
122 ** returns an integer equal to SQLITE_VERSION_NUMBER.
123 */
124 int sqlite3_libversion_number(void){ return SQLITE_VERSION_NUMBER; }
125 
126 /* IMPLEMENTATION-OF: R-20790-14025 The sqlite3_threadsafe() function returns
127 ** zero if and only if SQLite was compiled with mutexing code omitted due to
128 ** the SQLITE_THREADSAFE compile-time option being set to 0.
129 */
130 int sqlite3_threadsafe(void){ return SQLITE_THREADSAFE; }
131 
132 /*
133 ** When compiling the test fixture or with debugging enabled (on Win32),
134 ** this variable being set to non-zero will cause OSTRACE macros to emit
135 ** extra diagnostic information.
136 */
137 #ifdef SQLITE_HAVE_OS_TRACE
138 # ifndef SQLITE_DEBUG_OS_TRACE
139 #   define SQLITE_DEBUG_OS_TRACE 0
140 # endif
141   int sqlite3OSTrace = SQLITE_DEBUG_OS_TRACE;
142 #endif
143 
144 #if !defined(SQLITE_OMIT_TRACE) && defined(SQLITE_ENABLE_IOTRACE)
145 /*
146 ** If the following function pointer is not NULL and if
147 ** SQLITE_ENABLE_IOTRACE is enabled, then messages describing
148 ** I/O active are written using this function.  These messages
149 ** are intended for debugging activity only.
150 */
151 SQLITE_API void (SQLITE_CDECL *sqlite3IoTrace)(const char*, ...) = 0;
152 #endif
153 
154 /*
155 ** If the following global variable points to a string which is the
156 ** name of a directory, then that directory will be used to store
157 ** temporary files.
158 **
159 ** See also the "PRAGMA temp_store_directory" SQL command.
160 */
161 char *sqlite3_temp_directory = 0;
162 
163 /*
164 ** If the following global variable points to a string which is the
165 ** name of a directory, then that directory will be used to store
166 ** all database files specified with a relative pathname.
167 **
168 ** See also the "PRAGMA data_store_directory" SQL command.
169 */
170 char *sqlite3_data_directory = 0;
171 
172 /*
173 ** Initialize SQLite.
174 **
175 ** This routine must be called to initialize the memory allocation,
176 ** VFS, and mutex subsystems prior to doing any serious work with
177 ** SQLite.  But as long as you do not compile with SQLITE_OMIT_AUTOINIT
178 ** this routine will be called automatically by key routines such as
179 ** sqlite3_open().
180 **
181 ** This routine is a no-op except on its very first call for the process,
182 ** or for the first call after a call to sqlite3_shutdown.
183 **
184 ** The first thread to call this routine runs the initialization to
185 ** completion.  If subsequent threads call this routine before the first
186 ** thread has finished the initialization process, then the subsequent
187 ** threads must block until the first thread finishes with the initialization.
188 **
189 ** The first thread might call this routine recursively.  Recursive
190 ** calls to this routine should not block, of course.  Otherwise the
191 ** initialization process would never complete.
192 **
193 ** Let X be the first thread to enter this routine.  Let Y be some other
194 ** thread.  Then while the initial invocation of this routine by X is
195 ** incomplete, it is required that:
196 **
197 **    *  Calls to this routine from Y must block until the outer-most
198 **       call by X completes.
199 **
200 **    *  Recursive calls to this routine from thread X return immediately
201 **       without blocking.
202 */
203 int sqlite3_initialize(void){
204   MUTEX_LOGIC( sqlite3_mutex *pMaster; )       /* The main static mutex */
205   int rc;                                      /* Result code */
206 #ifdef SQLITE_EXTRA_INIT
207   int bRunExtraInit = 0;                       /* Extra initialization needed */
208 #endif
209 
210 #ifdef SQLITE_OMIT_WSD
211   rc = sqlite3_wsd_init(4096, 24);
212   if( rc!=SQLITE_OK ){
213     return rc;
214   }
215 #endif
216 
217   /* If the following assert() fails on some obscure processor/compiler
218   ** combination, the work-around is to set the correct pointer
219   ** size at compile-time using -DSQLITE_PTRSIZE=n compile-time option */
220   assert( SQLITE_PTRSIZE==sizeof(char*) );
221 
222   /* If SQLite is already completely initialized, then this call
223   ** to sqlite3_initialize() should be a no-op.  But the initialization
224   ** must be complete.  So isInit must not be set until the very end
225   ** of this routine.
226   */
227   if( sqlite3GlobalConfig.isInit ){
228     sqlite3MemoryBarrier();
229     return SQLITE_OK;
230   }
231 
232   /* Make sure the mutex subsystem is initialized.  If unable to
233   ** initialize the mutex subsystem, return early with the error.
234   ** If the system is so sick that we are unable to allocate a mutex,
235   ** there is not much SQLite is going to be able to do.
236   **
237   ** The mutex subsystem must take care of serializing its own
238   ** initialization.
239   */
240   rc = sqlite3MutexInit();
241   if( rc ) return rc;
242 
243   /* Initialize the malloc() system and the recursive pInitMutex mutex.
244   ** This operation is protected by the STATIC_MASTER mutex.  Note that
245   ** MutexAlloc() is called for a static mutex prior to initializing the
246   ** malloc subsystem - this implies that the allocation of a static
247   ** mutex must not require support from the malloc subsystem.
248   */
249   MUTEX_LOGIC( pMaster = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER); )
250   sqlite3_mutex_enter(pMaster);
251   sqlite3GlobalConfig.isMutexInit = 1;
252   if( !sqlite3GlobalConfig.isMallocInit ){
253     rc = sqlite3MallocInit();
254   }
255   if( rc==SQLITE_OK ){
256     sqlite3GlobalConfig.isMallocInit = 1;
257     if( !sqlite3GlobalConfig.pInitMutex ){
258       sqlite3GlobalConfig.pInitMutex =
259            sqlite3MutexAlloc(SQLITE_MUTEX_RECURSIVE);
260       if( sqlite3GlobalConfig.bCoreMutex && !sqlite3GlobalConfig.pInitMutex ){
261         rc = SQLITE_NOMEM_BKPT;
262       }
263     }
264   }
265   if( rc==SQLITE_OK ){
266     sqlite3GlobalConfig.nRefInitMutex++;
267   }
268   sqlite3_mutex_leave(pMaster);
269 
270   /* If rc is not SQLITE_OK at this point, then either the malloc
271   ** subsystem could not be initialized or the system failed to allocate
272   ** the pInitMutex mutex. Return an error in either case.  */
273   if( rc!=SQLITE_OK ){
274     return rc;
275   }
276 
277   /* Do the rest of the initialization under the recursive mutex so
278   ** that we will be able to handle recursive calls into
279   ** sqlite3_initialize().  The recursive calls normally come through
280   ** sqlite3_os_init() when it invokes sqlite3_vfs_register(), but other
281   ** recursive calls might also be possible.
282   **
283   ** IMPLEMENTATION-OF: R-00140-37445 SQLite automatically serializes calls
284   ** to the xInit method, so the xInit method need not be threadsafe.
285   **
286   ** The following mutex is what serializes access to the appdef pcache xInit
287   ** methods.  The sqlite3_pcache_methods.xInit() all is embedded in the
288   ** call to sqlite3PcacheInitialize().
289   */
290   sqlite3_mutex_enter(sqlite3GlobalConfig.pInitMutex);
291   if( sqlite3GlobalConfig.isInit==0 && sqlite3GlobalConfig.inProgress==0 ){
292     sqlite3GlobalConfig.inProgress = 1;
293 #ifdef SQLITE_ENABLE_SQLLOG
294     {
295       extern void sqlite3_init_sqllog(void);
296       sqlite3_init_sqllog();
297     }
298 #endif
299     memset(&sqlite3BuiltinFunctions, 0, sizeof(sqlite3BuiltinFunctions));
300     sqlite3RegisterBuiltinFunctions();
301     if( sqlite3GlobalConfig.isPCacheInit==0 ){
302       rc = sqlite3PcacheInitialize();
303     }
304     if( rc==SQLITE_OK ){
305       sqlite3GlobalConfig.isPCacheInit = 1;
306       rc = sqlite3OsInit();
307     }
308 #ifdef SQLITE_ENABLE_DESERIALIZE
309     if( rc==SQLITE_OK ){
310       rc = sqlite3MemdbInit();
311     }
312 #endif
313     if( rc==SQLITE_OK ){
314       sqlite3PCacheBufferSetup( sqlite3GlobalConfig.pPage,
315           sqlite3GlobalConfig.szPage, sqlite3GlobalConfig.nPage);
316       sqlite3GlobalConfig.isInit = 1;
317 #ifdef SQLITE_EXTRA_INIT
318       bRunExtraInit = 1;
319 #endif
320     }
321     sqlite3GlobalConfig.inProgress = 0;
322   }
323   sqlite3_mutex_leave(sqlite3GlobalConfig.pInitMutex);
324 
325   /* Go back under the static mutex and clean up the recursive
326   ** mutex to prevent a resource leak.
327   */
328   sqlite3_mutex_enter(pMaster);
329   sqlite3GlobalConfig.nRefInitMutex--;
330   if( sqlite3GlobalConfig.nRefInitMutex<=0 ){
331     assert( sqlite3GlobalConfig.nRefInitMutex==0 );
332     sqlite3_mutex_free(sqlite3GlobalConfig.pInitMutex);
333     sqlite3GlobalConfig.pInitMutex = 0;
334   }
335   sqlite3_mutex_leave(pMaster);
336 
337   /* The following is just a sanity check to make sure SQLite has
338   ** been compiled correctly.  It is important to run this code, but
339   ** we don't want to run it too often and soak up CPU cycles for no
340   ** reason.  So we run it once during initialization.
341   */
342 #ifndef NDEBUG
343 #ifndef SQLITE_OMIT_FLOATING_POINT
344   /* This section of code's only "output" is via assert() statements. */
345   if( rc==SQLITE_OK ){
346     u64 x = (((u64)1)<<63)-1;
347     double y;
348     assert(sizeof(x)==8);
349     assert(sizeof(x)==sizeof(y));
350     memcpy(&y, &x, 8);
351     assert( sqlite3IsNaN(y) );
352   }
353 #endif
354 #endif
355 
356   /* Do extra initialization steps requested by the SQLITE_EXTRA_INIT
357   ** compile-time option.
358   */
359 #ifdef SQLITE_EXTRA_INIT
360   if( bRunExtraInit ){
361     int SQLITE_EXTRA_INIT(const char*);
362     rc = SQLITE_EXTRA_INIT(0);
363   }
364 #endif
365 
366   return rc;
367 }
368 
369 /*
370 ** Undo the effects of sqlite3_initialize().  Must not be called while
371 ** there are outstanding database connections or memory allocations or
372 ** while any part of SQLite is otherwise in use in any thread.  This
373 ** routine is not threadsafe.  But it is safe to invoke this routine
374 ** on when SQLite is already shut down.  If SQLite is already shut down
375 ** when this routine is invoked, then this routine is a harmless no-op.
376 */
377 int sqlite3_shutdown(void){
378 #ifdef SQLITE_OMIT_WSD
379   int rc = sqlite3_wsd_init(4096, 24);
380   if( rc!=SQLITE_OK ){
381     return rc;
382   }
383 #endif
384 
385   if( sqlite3GlobalConfig.isInit ){
386 #ifdef SQLITE_EXTRA_SHUTDOWN
387     void SQLITE_EXTRA_SHUTDOWN(void);
388     SQLITE_EXTRA_SHUTDOWN();
389 #endif
390     sqlite3_os_end();
391     sqlite3_reset_auto_extension();
392     sqlite3GlobalConfig.isInit = 0;
393   }
394   if( sqlite3GlobalConfig.isPCacheInit ){
395     sqlite3PcacheShutdown();
396     sqlite3GlobalConfig.isPCacheInit = 0;
397   }
398   if( sqlite3GlobalConfig.isMallocInit ){
399     sqlite3MallocEnd();
400     sqlite3GlobalConfig.isMallocInit = 0;
401 
402 #ifndef SQLITE_OMIT_SHUTDOWN_DIRECTORIES
403     /* The heap subsystem has now been shutdown and these values are supposed
404     ** to be NULL or point to memory that was obtained from sqlite3_malloc(),
405     ** which would rely on that heap subsystem; therefore, make sure these
406     ** values cannot refer to heap memory that was just invalidated when the
407     ** heap subsystem was shutdown.  This is only done if the current call to
408     ** this function resulted in the heap subsystem actually being shutdown.
409     */
410     sqlite3_data_directory = 0;
411     sqlite3_temp_directory = 0;
412 #endif
413   }
414   if( sqlite3GlobalConfig.isMutexInit ){
415     sqlite3MutexEnd();
416     sqlite3GlobalConfig.isMutexInit = 0;
417   }
418 
419   return SQLITE_OK;
420 }
421 
422 /*
423 ** This API allows applications to modify the global configuration of
424 ** the SQLite library at run-time.
425 **
426 ** This routine should only be called when there are no outstanding
427 ** database connections or memory allocations.  This routine is not
428 ** threadsafe.  Failure to heed these warnings can lead to unpredictable
429 ** behavior.
430 */
431 int sqlite3_config(int op, ...){
432   va_list ap;
433   int rc = SQLITE_OK;
434 
435   /* sqlite3_config() shall return SQLITE_MISUSE if it is invoked while
436   ** the SQLite library is in use. */
437   if( sqlite3GlobalConfig.isInit ) return SQLITE_MISUSE_BKPT;
438 
439   va_start(ap, op);
440   switch( op ){
441 
442     /* Mutex configuration options are only available in a threadsafe
443     ** compile.
444     */
445 #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0  /* IMP: R-54466-46756 */
446     case SQLITE_CONFIG_SINGLETHREAD: {
447       /* EVIDENCE-OF: R-02748-19096 This option sets the threading mode to
448       ** Single-thread. */
449       sqlite3GlobalConfig.bCoreMutex = 0;  /* Disable mutex on core */
450       sqlite3GlobalConfig.bFullMutex = 0;  /* Disable mutex on connections */
451       break;
452     }
453 #endif
454 #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-20520-54086 */
455     case SQLITE_CONFIG_MULTITHREAD: {
456       /* EVIDENCE-OF: R-14374-42468 This option sets the threading mode to
457       ** Multi-thread. */
458       sqlite3GlobalConfig.bCoreMutex = 1;  /* Enable mutex on core */
459       sqlite3GlobalConfig.bFullMutex = 0;  /* Disable mutex on connections */
460       break;
461     }
462 #endif
463 #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-59593-21810 */
464     case SQLITE_CONFIG_SERIALIZED: {
465       /* EVIDENCE-OF: R-41220-51800 This option sets the threading mode to
466       ** Serialized. */
467       sqlite3GlobalConfig.bCoreMutex = 1;  /* Enable mutex on core */
468       sqlite3GlobalConfig.bFullMutex = 1;  /* Enable mutex on connections */
469       break;
470     }
471 #endif
472 #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-63666-48755 */
473     case SQLITE_CONFIG_MUTEX: {
474       /* Specify an alternative mutex implementation */
475       sqlite3GlobalConfig.mutex = *va_arg(ap, sqlite3_mutex_methods*);
476       break;
477     }
478 #endif
479 #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-14450-37597 */
480     case SQLITE_CONFIG_GETMUTEX: {
481       /* Retrieve the current mutex implementation */
482       *va_arg(ap, sqlite3_mutex_methods*) = sqlite3GlobalConfig.mutex;
483       break;
484     }
485 #endif
486 
487     case SQLITE_CONFIG_MALLOC: {
488       /* EVIDENCE-OF: R-55594-21030 The SQLITE_CONFIG_MALLOC option takes a
489       ** single argument which is a pointer to an instance of the
490       ** sqlite3_mem_methods structure. The argument specifies alternative
491       ** low-level memory allocation routines to be used in place of the memory
492       ** allocation routines built into SQLite. */
493       sqlite3GlobalConfig.m = *va_arg(ap, sqlite3_mem_methods*);
494       break;
495     }
496     case SQLITE_CONFIG_GETMALLOC: {
497       /* EVIDENCE-OF: R-51213-46414 The SQLITE_CONFIG_GETMALLOC option takes a
498       ** single argument which is a pointer to an instance of the
499       ** sqlite3_mem_methods structure. The sqlite3_mem_methods structure is
500       ** filled with the currently defined memory allocation routines. */
501       if( sqlite3GlobalConfig.m.xMalloc==0 ) sqlite3MemSetDefault();
502       *va_arg(ap, sqlite3_mem_methods*) = sqlite3GlobalConfig.m;
503       break;
504     }
505     case SQLITE_CONFIG_MEMSTATUS: {
506       /* EVIDENCE-OF: R-61275-35157 The SQLITE_CONFIG_MEMSTATUS option takes
507       ** single argument of type int, interpreted as a boolean, which enables
508       ** or disables the collection of memory allocation statistics. */
509       sqlite3GlobalConfig.bMemstat = va_arg(ap, int);
510       break;
511     }
512     case SQLITE_CONFIG_SMALL_MALLOC: {
513       sqlite3GlobalConfig.bSmallMalloc = va_arg(ap, int);
514       break;
515     }
516     case SQLITE_CONFIG_PAGECACHE: {
517       /* EVIDENCE-OF: R-18761-36601 There are three arguments to
518       ** SQLITE_CONFIG_PAGECACHE: A pointer to 8-byte aligned memory (pMem),
519       ** the size of each page cache line (sz), and the number of cache lines
520       ** (N). */
521       sqlite3GlobalConfig.pPage = va_arg(ap, void*);
522       sqlite3GlobalConfig.szPage = va_arg(ap, int);
523       sqlite3GlobalConfig.nPage = va_arg(ap, int);
524       break;
525     }
526     case SQLITE_CONFIG_PCACHE_HDRSZ: {
527       /* EVIDENCE-OF: R-39100-27317 The SQLITE_CONFIG_PCACHE_HDRSZ option takes
528       ** a single parameter which is a pointer to an integer and writes into
529       ** that integer the number of extra bytes per page required for each page
530       ** in SQLITE_CONFIG_PAGECACHE. */
531       *va_arg(ap, int*) =
532           sqlite3HeaderSizeBtree() +
533           sqlite3HeaderSizePcache() +
534           sqlite3HeaderSizePcache1();
535       break;
536     }
537 
538     case SQLITE_CONFIG_PCACHE: {
539       /* no-op */
540       break;
541     }
542     case SQLITE_CONFIG_GETPCACHE: {
543       /* now an error */
544       rc = SQLITE_ERROR;
545       break;
546     }
547 
548     case SQLITE_CONFIG_PCACHE2: {
549       /* EVIDENCE-OF: R-63325-48378 The SQLITE_CONFIG_PCACHE2 option takes a
550       ** single argument which is a pointer to an sqlite3_pcache_methods2
551       ** object. This object specifies the interface to a custom page cache
552       ** implementation. */
553       sqlite3GlobalConfig.pcache2 = *va_arg(ap, sqlite3_pcache_methods2*);
554       break;
555     }
556     case SQLITE_CONFIG_GETPCACHE2: {
557       /* EVIDENCE-OF: R-22035-46182 The SQLITE_CONFIG_GETPCACHE2 option takes a
558       ** single argument which is a pointer to an sqlite3_pcache_methods2
559       ** object. SQLite copies of the current page cache implementation into
560       ** that object. */
561       if( sqlite3GlobalConfig.pcache2.xInit==0 ){
562         sqlite3PCacheSetDefault();
563       }
564       *va_arg(ap, sqlite3_pcache_methods2*) = sqlite3GlobalConfig.pcache2;
565       break;
566     }
567 
568 /* EVIDENCE-OF: R-06626-12911 The SQLITE_CONFIG_HEAP option is only
569 ** available if SQLite is compiled with either SQLITE_ENABLE_MEMSYS3 or
570 ** SQLITE_ENABLE_MEMSYS5 and returns SQLITE_ERROR if invoked otherwise. */
571 #if defined(SQLITE_ENABLE_MEMSYS3) || defined(SQLITE_ENABLE_MEMSYS5)
572     case SQLITE_CONFIG_HEAP: {
573       /* EVIDENCE-OF: R-19854-42126 There are three arguments to
574       ** SQLITE_CONFIG_HEAP: An 8-byte aligned pointer to the memory, the
575       ** number of bytes in the memory buffer, and the minimum allocation size.
576       */
577       sqlite3GlobalConfig.pHeap = va_arg(ap, void*);
578       sqlite3GlobalConfig.nHeap = va_arg(ap, int);
579       sqlite3GlobalConfig.mnReq = va_arg(ap, int);
580 
581       if( sqlite3GlobalConfig.mnReq<1 ){
582         sqlite3GlobalConfig.mnReq = 1;
583       }else if( sqlite3GlobalConfig.mnReq>(1<<12) ){
584         /* cap min request size at 2^12 */
585         sqlite3GlobalConfig.mnReq = (1<<12);
586       }
587 
588       if( sqlite3GlobalConfig.pHeap==0 ){
589         /* EVIDENCE-OF: R-49920-60189 If the first pointer (the memory pointer)
590         ** is NULL, then SQLite reverts to using its default memory allocator
591         ** (the system malloc() implementation), undoing any prior invocation of
592         ** SQLITE_CONFIG_MALLOC.
593         **
594         ** Setting sqlite3GlobalConfig.m to all zeros will cause malloc to
595         ** revert to its default implementation when sqlite3_initialize() is run
596         */
597         memset(&sqlite3GlobalConfig.m, 0, sizeof(sqlite3GlobalConfig.m));
598       }else{
599         /* EVIDENCE-OF: R-61006-08918 If the memory pointer is not NULL then the
600         ** alternative memory allocator is engaged to handle all of SQLites
601         ** memory allocation needs. */
602 #ifdef SQLITE_ENABLE_MEMSYS3
603         sqlite3GlobalConfig.m = *sqlite3MemGetMemsys3();
604 #endif
605 #ifdef SQLITE_ENABLE_MEMSYS5
606         sqlite3GlobalConfig.m = *sqlite3MemGetMemsys5();
607 #endif
608       }
609       break;
610     }
611 #endif
612 
613     case SQLITE_CONFIG_LOOKASIDE: {
614       sqlite3GlobalConfig.szLookaside = va_arg(ap, int);
615       sqlite3GlobalConfig.nLookaside = va_arg(ap, int);
616       break;
617     }
618 
619     /* Record a pointer to the logger function and its first argument.
620     ** The default is NULL.  Logging is disabled if the function pointer is
621     ** NULL.
622     */
623     case SQLITE_CONFIG_LOG: {
624       /* MSVC is picky about pulling func ptrs from va lists.
625       ** http://support.microsoft.com/kb/47961
626       ** sqlite3GlobalConfig.xLog = va_arg(ap, void(*)(void*,int,const char*));
627       */
628       typedef void(*LOGFUNC_t)(void*,int,const char*);
629       sqlite3GlobalConfig.xLog = va_arg(ap, LOGFUNC_t);
630       sqlite3GlobalConfig.pLogArg = va_arg(ap, void*);
631       break;
632     }
633 
634     /* EVIDENCE-OF: R-55548-33817 The compile-time setting for URI filenames
635     ** can be changed at start-time using the
636     ** sqlite3_config(SQLITE_CONFIG_URI,1) or
637     ** sqlite3_config(SQLITE_CONFIG_URI,0) configuration calls.
638     */
639     case SQLITE_CONFIG_URI: {
640       /* EVIDENCE-OF: R-25451-61125 The SQLITE_CONFIG_URI option takes a single
641       ** argument of type int. If non-zero, then URI handling is globally
642       ** enabled. If the parameter is zero, then URI handling is globally
643       ** disabled. */
644       sqlite3GlobalConfig.bOpenUri = va_arg(ap, int);
645       break;
646     }
647 
648     case SQLITE_CONFIG_COVERING_INDEX_SCAN: {
649       /* EVIDENCE-OF: R-36592-02772 The SQLITE_CONFIG_COVERING_INDEX_SCAN
650       ** option takes a single integer argument which is interpreted as a
651       ** boolean in order to enable or disable the use of covering indices for
652       ** full table scans in the query optimizer. */
653       sqlite3GlobalConfig.bUseCis = va_arg(ap, int);
654       break;
655     }
656 
657 #ifdef SQLITE_ENABLE_SQLLOG
658     case SQLITE_CONFIG_SQLLOG: {
659       typedef void(*SQLLOGFUNC_t)(void*, sqlite3*, const char*, int);
660       sqlite3GlobalConfig.xSqllog = va_arg(ap, SQLLOGFUNC_t);
661       sqlite3GlobalConfig.pSqllogArg = va_arg(ap, void *);
662       break;
663     }
664 #endif
665 
666     case SQLITE_CONFIG_MMAP_SIZE: {
667       /* EVIDENCE-OF: R-58063-38258 SQLITE_CONFIG_MMAP_SIZE takes two 64-bit
668       ** integer (sqlite3_int64) values that are the default mmap size limit
669       ** (the default setting for PRAGMA mmap_size) and the maximum allowed
670       ** mmap size limit. */
671       sqlite3_int64 szMmap = va_arg(ap, sqlite3_int64);
672       sqlite3_int64 mxMmap = va_arg(ap, sqlite3_int64);
673       /* EVIDENCE-OF: R-53367-43190 If either argument to this option is
674       ** negative, then that argument is changed to its compile-time default.
675       **
676       ** EVIDENCE-OF: R-34993-45031 The maximum allowed mmap size will be
677       ** silently truncated if necessary so that it does not exceed the
678       ** compile-time maximum mmap size set by the SQLITE_MAX_MMAP_SIZE
679       ** compile-time option.
680       */
681       if( mxMmap<0 || mxMmap>SQLITE_MAX_MMAP_SIZE ){
682         mxMmap = SQLITE_MAX_MMAP_SIZE;
683       }
684       if( szMmap<0 ) szMmap = SQLITE_DEFAULT_MMAP_SIZE;
685       if( szMmap>mxMmap) szMmap = mxMmap;
686       sqlite3GlobalConfig.mxMmap = mxMmap;
687       sqlite3GlobalConfig.szMmap = szMmap;
688       break;
689     }
690 
691 #if SQLITE_OS_WIN && defined(SQLITE_WIN32_MALLOC) /* IMP: R-04780-55815 */
692     case SQLITE_CONFIG_WIN32_HEAPSIZE: {
693       /* EVIDENCE-OF: R-34926-03360 SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit
694       ** unsigned integer value that specifies the maximum size of the created
695       ** heap. */
696       sqlite3GlobalConfig.nHeap = va_arg(ap, int);
697       break;
698     }
699 #endif
700 
701     case SQLITE_CONFIG_PMASZ: {
702       sqlite3GlobalConfig.szPma = va_arg(ap, unsigned int);
703       break;
704     }
705 
706     case SQLITE_CONFIG_STMTJRNL_SPILL: {
707       sqlite3GlobalConfig.nStmtSpill = va_arg(ap, int);
708       break;
709     }
710 
711 #ifdef SQLITE_ENABLE_SORTER_REFERENCES
712     case SQLITE_CONFIG_SORTERREF_SIZE: {
713       int iVal = va_arg(ap, int);
714       if( iVal<0 ){
715         iVal = SQLITE_DEFAULT_SORTERREF_SIZE;
716       }
717       sqlite3GlobalConfig.szSorterRef = (u32)iVal;
718       break;
719     }
720 #endif /* SQLITE_ENABLE_SORTER_REFERENCES */
721 
722 #ifdef SQLITE_ENABLE_DESERIALIZE
723     case SQLITE_CONFIG_MEMDB_MAXSIZE: {
724       sqlite3GlobalConfig.mxMemdbSize = va_arg(ap, sqlite3_int64);
725       break;
726     }
727 #endif /* SQLITE_ENABLE_DESERIALIZE */
728 
729     default: {
730       rc = SQLITE_ERROR;
731       break;
732     }
733   }
734   va_end(ap);
735   return rc;
736 }
737 
738 /*
739 ** Set up the lookaside buffers for a database connection.
740 ** Return SQLITE_OK on success.
741 ** If lookaside is already active, return SQLITE_BUSY.
742 **
743 ** The sz parameter is the number of bytes in each lookaside slot.
744 ** The cnt parameter is the number of slots.  If pStart is NULL the
745 ** space for the lookaside memory is obtained from sqlite3_malloc().
746 ** If pStart is not NULL then it is sz*cnt bytes of memory to use for
747 ** the lookaside memory.
748 */
749 static int setupLookaside(sqlite3 *db, void *pBuf, int sz, int cnt){
750 #ifndef SQLITE_OMIT_LOOKASIDE
751   void *pStart;
752   sqlite3_int64 szAlloc = sz*(sqlite3_int64)cnt;
753   int nBig;   /* Number of full-size slots */
754   int nSm;    /* Number smaller LOOKASIDE_SMALL-byte slots */
755 
756   if( sqlite3LookasideUsed(db,0)>0 ){
757     return SQLITE_BUSY;
758   }
759   /* Free any existing lookaside buffer for this handle before
760   ** allocating a new one so we don't have to have space for
761   ** both at the same time.
762   */
763   if( db->lookaside.bMalloced ){
764     sqlite3_free(db->lookaside.pStart);
765   }
766   /* The size of a lookaside slot after ROUNDDOWN8 needs to be larger
767   ** than a pointer to be useful.
768   */
769   sz = ROUNDDOWN8(sz);  /* IMP: R-33038-09382 */
770   if( sz<=(int)sizeof(LookasideSlot*) ) sz = 0;
771   if( cnt<0 ) cnt = 0;
772   if( sz==0 || cnt==0 ){
773     sz = 0;
774     pStart = 0;
775   }else if( pBuf==0 ){
776     sqlite3BeginBenignMalloc();
777     pStart = sqlite3Malloc( szAlloc );  /* IMP: R-61949-35727 */
778     sqlite3EndBenignMalloc();
779     if( pStart ) szAlloc = sqlite3MallocSize(pStart);
780   }else{
781     pStart = pBuf;
782   }
783 #ifndef SQLITE_OMIT_TWOSIZE_LOOKASIDE
784   if( sz>=LOOKASIDE_SMALL*3 ){
785     nBig = szAlloc/(3*LOOKASIDE_SMALL+sz);
786     nSm = (szAlloc - sz*nBig)/LOOKASIDE_SMALL;
787   }else if( sz>=LOOKASIDE_SMALL*2 ){
788     nBig = szAlloc/(LOOKASIDE_SMALL+sz);
789     nSm = (szAlloc - sz*nBig)/LOOKASIDE_SMALL;
790   }else
791 #endif /* SQLITE_OMIT_TWOSIZE_LOOKASIDE */
792   if( sz>0 ){
793     nBig = szAlloc/sz;
794     nSm = 0;
795   }else{
796     nBig = nSm = 0;
797   }
798   db->lookaside.pStart = pStart;
799   db->lookaside.pInit = 0;
800   db->lookaside.pFree = 0;
801   db->lookaside.sz = (u16)sz;
802   db->lookaside.szTrue = (u16)sz;
803   if( pStart ){
804     int i;
805     LookasideSlot *p;
806     assert( sz > (int)sizeof(LookasideSlot*) );
807     p = (LookasideSlot*)pStart;
808     for(i=0; i<nBig; i++){
809       p->pNext = db->lookaside.pInit;
810       db->lookaside.pInit = p;
811       p = (LookasideSlot*)&((u8*)p)[sz];
812     }
813 #ifndef SQLITE_OMIT_TWOSIZE_LOOKASIDE
814     db->lookaside.pSmallInit = 0;
815     db->lookaside.pSmallFree = 0;
816     db->lookaside.pMiddle = p;
817     for(i=0; i<nSm; i++){
818       p->pNext = db->lookaside.pSmallInit;
819       db->lookaside.pSmallInit = p;
820       p = (LookasideSlot*)&((u8*)p)[LOOKASIDE_SMALL];
821     }
822 #endif /* SQLITE_OMIT_TWOSIZE_LOOKASIDE */
823     assert( ((uptr)p)<=szAlloc + (uptr)pStart );
824     db->lookaside.pEnd = p;
825     db->lookaside.bDisable = 0;
826     db->lookaside.bMalloced = pBuf==0 ?1:0;
827     db->lookaside.nSlot = nBig+nSm;
828   }else{
829     db->lookaside.pStart = db;
830 #ifndef SQLITE_OMIT_TWOSIZE_LOOKASIDE
831     db->lookaside.pSmallInit = 0;
832     db->lookaside.pSmallFree = 0;
833     db->lookaside.pMiddle = db;
834 #endif /* SQLITE_OMIT_TWOSIZE_LOOKASIDE */
835     db->lookaside.pEnd = db;
836     db->lookaside.bDisable = 1;
837     db->lookaside.sz = 0;
838     db->lookaside.bMalloced = 0;
839     db->lookaside.nSlot = 0;
840   }
841   assert( sqlite3LookasideUsed(db,0)==0 );
842 #endif /* SQLITE_OMIT_LOOKASIDE */
843   return SQLITE_OK;
844 }
845 
846 /*
847 ** Return the mutex associated with a database connection.
848 */
849 sqlite3_mutex *sqlite3_db_mutex(sqlite3 *db){
850 #ifdef SQLITE_ENABLE_API_ARMOR
851   if( !sqlite3SafetyCheckOk(db) ){
852     (void)SQLITE_MISUSE_BKPT;
853     return 0;
854   }
855 #endif
856   return db->mutex;
857 }
858 
859 /*
860 ** Free up as much memory as we can from the given database
861 ** connection.
862 */
863 int sqlite3_db_release_memory(sqlite3 *db){
864   int i;
865 
866 #ifdef SQLITE_ENABLE_API_ARMOR
867   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
868 #endif
869   sqlite3_mutex_enter(db->mutex);
870   sqlite3BtreeEnterAll(db);
871   for(i=0; i<db->nDb; i++){
872     Btree *pBt = db->aDb[i].pBt;
873     if( pBt ){
874       Pager *pPager = sqlite3BtreePager(pBt);
875       sqlite3PagerShrink(pPager);
876     }
877   }
878   sqlite3BtreeLeaveAll(db);
879   sqlite3_mutex_leave(db->mutex);
880   return SQLITE_OK;
881 }
882 
883 /*
884 ** Flush any dirty pages in the pager-cache for any attached database
885 ** to disk.
886 */
887 int sqlite3_db_cacheflush(sqlite3 *db){
888   int i;
889   int rc = SQLITE_OK;
890   int bSeenBusy = 0;
891 
892 #ifdef SQLITE_ENABLE_API_ARMOR
893   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
894 #endif
895   sqlite3_mutex_enter(db->mutex);
896   sqlite3BtreeEnterAll(db);
897   for(i=0; rc==SQLITE_OK && i<db->nDb; i++){
898     Btree *pBt = db->aDb[i].pBt;
899     if( pBt && sqlite3BtreeIsInTrans(pBt) ){
900       Pager *pPager = sqlite3BtreePager(pBt);
901       rc = sqlite3PagerFlush(pPager);
902       if( rc==SQLITE_BUSY ){
903         bSeenBusy = 1;
904         rc = SQLITE_OK;
905       }
906     }
907   }
908   sqlite3BtreeLeaveAll(db);
909   sqlite3_mutex_leave(db->mutex);
910   return ((rc==SQLITE_OK && bSeenBusy) ? SQLITE_BUSY : rc);
911 }
912 
913 /*
914 ** Configuration settings for an individual database connection
915 */
916 int sqlite3_db_config(sqlite3 *db, int op, ...){
917   va_list ap;
918   int rc;
919   va_start(ap, op);
920   switch( op ){
921     case SQLITE_DBCONFIG_MAINDBNAME: {
922       /* IMP: R-06824-28531 */
923       /* IMP: R-36257-52125 */
924       db->aDb[0].zDbSName = va_arg(ap,char*);
925       rc = SQLITE_OK;
926       break;
927     }
928     case SQLITE_DBCONFIG_LOOKASIDE: {
929       void *pBuf = va_arg(ap, void*); /* IMP: R-26835-10964 */
930       int sz = va_arg(ap, int);       /* IMP: R-47871-25994 */
931       int cnt = va_arg(ap, int);      /* IMP: R-04460-53386 */
932       rc = setupLookaside(db, pBuf, sz, cnt);
933       break;
934     }
935     default: {
936       static const struct {
937         int op;      /* The opcode */
938         u32 mask;    /* Mask of the bit in sqlite3.flags to set/clear */
939       } aFlagOp[] = {
940         { SQLITE_DBCONFIG_ENABLE_FKEY,           SQLITE_ForeignKeys    },
941         { SQLITE_DBCONFIG_ENABLE_TRIGGER,        SQLITE_EnableTrigger  },
942         { SQLITE_DBCONFIG_ENABLE_VIEW,           SQLITE_EnableView     },
943         { SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER, SQLITE_Fts3Tokenizer  },
944         { SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION, SQLITE_LoadExtension  },
945         { SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE,      SQLITE_NoCkptOnClose  },
946         { SQLITE_DBCONFIG_ENABLE_QPSG,           SQLITE_EnableQPSG     },
947         { SQLITE_DBCONFIG_TRIGGER_EQP,           SQLITE_TriggerEQP     },
948         { SQLITE_DBCONFIG_RESET_DATABASE,        SQLITE_ResetDatabase  },
949         { SQLITE_DBCONFIG_DEFENSIVE,             SQLITE_Defensive      },
950         { SQLITE_DBCONFIG_WRITABLE_SCHEMA,       SQLITE_WriteSchema|
951                                                  SQLITE_NoSchemaError  },
952         { SQLITE_DBCONFIG_LEGACY_ALTER_TABLE,    SQLITE_LegacyAlter    },
953         { SQLITE_DBCONFIG_DQS_DDL,               SQLITE_DqsDDL         },
954         { SQLITE_DBCONFIG_DQS_DML,               SQLITE_DqsDML         },
955         { SQLITE_DBCONFIG_LEGACY_FILE_FORMAT,    SQLITE_LegacyFileFmt  },
956         { SQLITE_DBCONFIG_TRUSTED_SCHEMA,        SQLITE_TrustedSchema  },
957       };
958       unsigned int i;
959       rc = SQLITE_ERROR; /* IMP: R-42790-23372 */
960       for(i=0; i<ArraySize(aFlagOp); i++){
961         if( aFlagOp[i].op==op ){
962           int onoff = va_arg(ap, int);
963           int *pRes = va_arg(ap, int*);
964           u64 oldFlags = db->flags;
965           if( onoff>0 ){
966             db->flags |= aFlagOp[i].mask;
967           }else if( onoff==0 ){
968             db->flags &= ~(u64)aFlagOp[i].mask;
969           }
970           if( oldFlags!=db->flags ){
971             sqlite3ExpirePreparedStatements(db, 0);
972           }
973           if( pRes ){
974             *pRes = (db->flags & aFlagOp[i].mask)!=0;
975           }
976           rc = SQLITE_OK;
977           break;
978         }
979       }
980       break;
981     }
982   }
983   va_end(ap);
984   return rc;
985 }
986 
987 /*
988 ** This is the default collating function named "BINARY" which is always
989 ** available.
990 */
991 static int binCollFunc(
992   void *NotUsed,
993   int nKey1, const void *pKey1,
994   int nKey2, const void *pKey2
995 ){
996   int rc, n;
997   UNUSED_PARAMETER(NotUsed);
998   n = nKey1<nKey2 ? nKey1 : nKey2;
999   /* EVIDENCE-OF: R-65033-28449 The built-in BINARY collation compares
1000   ** strings byte by byte using the memcmp() function from the standard C
1001   ** library. */
1002   assert( pKey1 && pKey2 );
1003   rc = memcmp(pKey1, pKey2, n);
1004   if( rc==0 ){
1005     rc = nKey1 - nKey2;
1006   }
1007   return rc;
1008 }
1009 
1010 /*
1011 ** This is the collating function named "RTRIM" which is always
1012 ** available.  Ignore trailing spaces.
1013 */
1014 static int rtrimCollFunc(
1015   void *pUser,
1016   int nKey1, const void *pKey1,
1017   int nKey2, const void *pKey2
1018 ){
1019   const u8 *pK1 = (const u8*)pKey1;
1020   const u8 *pK2 = (const u8*)pKey2;
1021   while( nKey1 && pK1[nKey1-1]==' ' ) nKey1--;
1022   while( nKey2 && pK2[nKey2-1]==' ' ) nKey2--;
1023   return binCollFunc(pUser, nKey1, pKey1, nKey2, pKey2);
1024 }
1025 
1026 /*
1027 ** Return true if CollSeq is the default built-in BINARY.
1028 */
1029 int sqlite3IsBinary(const CollSeq *p){
1030   assert( p==0 || p->xCmp!=binCollFunc || strcmp(p->zName,"BINARY")==0 );
1031   return p==0 || p->xCmp==binCollFunc;
1032 }
1033 
1034 /*
1035 ** Another built-in collating sequence: NOCASE.
1036 **
1037 ** This collating sequence is intended to be used for "case independent
1038 ** comparison". SQLite's knowledge of upper and lower case equivalents
1039 ** extends only to the 26 characters used in the English language.
1040 **
1041 ** At the moment there is only a UTF-8 implementation.
1042 */
1043 static int nocaseCollatingFunc(
1044   void *NotUsed,
1045   int nKey1, const void *pKey1,
1046   int nKey2, const void *pKey2
1047 ){
1048   int r = sqlite3StrNICmp(
1049       (const char *)pKey1, (const char *)pKey2, (nKey1<nKey2)?nKey1:nKey2);
1050   UNUSED_PARAMETER(NotUsed);
1051   if( 0==r ){
1052     r = nKey1-nKey2;
1053   }
1054   return r;
1055 }
1056 
1057 /*
1058 ** Return the ROWID of the most recent insert
1059 */
1060 sqlite_int64 sqlite3_last_insert_rowid(sqlite3 *db){
1061 #ifdef SQLITE_ENABLE_API_ARMOR
1062   if( !sqlite3SafetyCheckOk(db) ){
1063     (void)SQLITE_MISUSE_BKPT;
1064     return 0;
1065   }
1066 #endif
1067   return db->lastRowid;
1068 }
1069 
1070 /*
1071 ** Set the value returned by the sqlite3_last_insert_rowid() API function.
1072 */
1073 void sqlite3_set_last_insert_rowid(sqlite3 *db, sqlite3_int64 iRowid){
1074 #ifdef SQLITE_ENABLE_API_ARMOR
1075   if( !sqlite3SafetyCheckOk(db) ){
1076     (void)SQLITE_MISUSE_BKPT;
1077     return;
1078   }
1079 #endif
1080   sqlite3_mutex_enter(db->mutex);
1081   db->lastRowid = iRowid;
1082   sqlite3_mutex_leave(db->mutex);
1083 }
1084 
1085 /*
1086 ** Return the number of changes in the most recent call to sqlite3_exec().
1087 */
1088 int sqlite3_changes(sqlite3 *db){
1089 #ifdef SQLITE_ENABLE_API_ARMOR
1090   if( !sqlite3SafetyCheckOk(db) ){
1091     (void)SQLITE_MISUSE_BKPT;
1092     return 0;
1093   }
1094 #endif
1095   return db->nChange;
1096 }
1097 
1098 /*
1099 ** Return the number of changes since the database handle was opened.
1100 */
1101 int sqlite3_total_changes(sqlite3 *db){
1102 #ifdef SQLITE_ENABLE_API_ARMOR
1103   if( !sqlite3SafetyCheckOk(db) ){
1104     (void)SQLITE_MISUSE_BKPT;
1105     return 0;
1106   }
1107 #endif
1108   return db->nTotalChange;
1109 }
1110 
1111 /*
1112 ** Close all open savepoints. This function only manipulates fields of the
1113 ** database handle object, it does not close any savepoints that may be open
1114 ** at the b-tree/pager level.
1115 */
1116 void sqlite3CloseSavepoints(sqlite3 *db){
1117   while( db->pSavepoint ){
1118     Savepoint *pTmp = db->pSavepoint;
1119     db->pSavepoint = pTmp->pNext;
1120     sqlite3DbFree(db, pTmp);
1121   }
1122   db->nSavepoint = 0;
1123   db->nStatement = 0;
1124   db->isTransactionSavepoint = 0;
1125 }
1126 
1127 /*
1128 ** Invoke the destructor function associated with FuncDef p, if any. Except,
1129 ** if this is not the last copy of the function, do not invoke it. Multiple
1130 ** copies of a single function are created when create_function() is called
1131 ** with SQLITE_ANY as the encoding.
1132 */
1133 static void functionDestroy(sqlite3 *db, FuncDef *p){
1134   FuncDestructor *pDestructor = p->u.pDestructor;
1135   if( pDestructor ){
1136     pDestructor->nRef--;
1137     if( pDestructor->nRef==0 ){
1138       pDestructor->xDestroy(pDestructor->pUserData);
1139       sqlite3DbFree(db, pDestructor);
1140     }
1141   }
1142 }
1143 
1144 /*
1145 ** Disconnect all sqlite3_vtab objects that belong to database connection
1146 ** db. This is called when db is being closed.
1147 */
1148 static void disconnectAllVtab(sqlite3 *db){
1149 #ifndef SQLITE_OMIT_VIRTUALTABLE
1150   int i;
1151   HashElem *p;
1152   sqlite3BtreeEnterAll(db);
1153   for(i=0; i<db->nDb; i++){
1154     Schema *pSchema = db->aDb[i].pSchema;
1155     if( pSchema ){
1156       for(p=sqliteHashFirst(&pSchema->tblHash); p; p=sqliteHashNext(p)){
1157         Table *pTab = (Table *)sqliteHashData(p);
1158         if( IsVirtual(pTab) ) sqlite3VtabDisconnect(db, pTab);
1159       }
1160     }
1161   }
1162   for(p=sqliteHashFirst(&db->aModule); p; p=sqliteHashNext(p)){
1163     Module *pMod = (Module *)sqliteHashData(p);
1164     if( pMod->pEpoTab ){
1165       sqlite3VtabDisconnect(db, pMod->pEpoTab);
1166     }
1167   }
1168   sqlite3VtabUnlockList(db);
1169   sqlite3BtreeLeaveAll(db);
1170 #else
1171   UNUSED_PARAMETER(db);
1172 #endif
1173 }
1174 
1175 /*
1176 ** Return TRUE if database connection db has unfinalized prepared
1177 ** statements or unfinished sqlite3_backup objects.
1178 */
1179 static int connectionIsBusy(sqlite3 *db){
1180   int j;
1181   assert( sqlite3_mutex_held(db->mutex) );
1182   if( db->pVdbe ) return 1;
1183   for(j=0; j<db->nDb; j++){
1184     Btree *pBt = db->aDb[j].pBt;
1185     if( pBt && sqlite3BtreeIsInBackup(pBt) ) return 1;
1186   }
1187   return 0;
1188 }
1189 
1190 /*
1191 ** Close an existing SQLite database
1192 */
1193 static int sqlite3Close(sqlite3 *db, int forceZombie){
1194   if( !db ){
1195     /* EVIDENCE-OF: R-63257-11740 Calling sqlite3_close() or
1196     ** sqlite3_close_v2() with a NULL pointer argument is a harmless no-op. */
1197     return SQLITE_OK;
1198   }
1199   if( !sqlite3SafetyCheckSickOrOk(db) ){
1200     return SQLITE_MISUSE_BKPT;
1201   }
1202   sqlite3_mutex_enter(db->mutex);
1203   if( db->mTrace & SQLITE_TRACE_CLOSE ){
1204     db->xTrace(SQLITE_TRACE_CLOSE, db->pTraceArg, db, 0);
1205   }
1206 
1207   /* Force xDisconnect calls on all virtual tables */
1208   disconnectAllVtab(db);
1209 
1210   /* If a transaction is open, the disconnectAllVtab() call above
1211   ** will not have called the xDisconnect() method on any virtual
1212   ** tables in the db->aVTrans[] array. The following sqlite3VtabRollback()
1213   ** call will do so. We need to do this before the check for active
1214   ** SQL statements below, as the v-table implementation may be storing
1215   ** some prepared statements internally.
1216   */
1217   sqlite3VtabRollback(db);
1218 
1219   /* Legacy behavior (sqlite3_close() behavior) is to return
1220   ** SQLITE_BUSY if the connection can not be closed immediately.
1221   */
1222   if( !forceZombie && connectionIsBusy(db) ){
1223     sqlite3ErrorWithMsg(db, SQLITE_BUSY, "unable to close due to unfinalized "
1224        "statements or unfinished backups");
1225     sqlite3_mutex_leave(db->mutex);
1226     return SQLITE_BUSY;
1227   }
1228 
1229 #ifdef SQLITE_ENABLE_SQLLOG
1230   if( sqlite3GlobalConfig.xSqllog ){
1231     /* Closing the handle. Fourth parameter is passed the value 2. */
1232     sqlite3GlobalConfig.xSqllog(sqlite3GlobalConfig.pSqllogArg, db, 0, 2);
1233   }
1234 #endif
1235 
1236   /* Convert the connection into a zombie and then close it.
1237   */
1238   db->magic = SQLITE_MAGIC_ZOMBIE;
1239   sqlite3LeaveMutexAndCloseZombie(db);
1240   return SQLITE_OK;
1241 }
1242 
1243 /*
1244 ** Two variations on the public interface for closing a database
1245 ** connection. The sqlite3_close() version returns SQLITE_BUSY and
1246 ** leaves the connection option if there are unfinalized prepared
1247 ** statements or unfinished sqlite3_backups.  The sqlite3_close_v2()
1248 ** version forces the connection to become a zombie if there are
1249 ** unclosed resources, and arranges for deallocation when the last
1250 ** prepare statement or sqlite3_backup closes.
1251 */
1252 int sqlite3_close(sqlite3 *db){ return sqlite3Close(db,0); }
1253 int sqlite3_close_v2(sqlite3 *db){ return sqlite3Close(db,1); }
1254 
1255 
1256 /*
1257 ** Close the mutex on database connection db.
1258 **
1259 ** Furthermore, if database connection db is a zombie (meaning that there
1260 ** has been a prior call to sqlite3_close(db) or sqlite3_close_v2(db)) and
1261 ** every sqlite3_stmt has now been finalized and every sqlite3_backup has
1262 ** finished, then free all resources.
1263 */
1264 void sqlite3LeaveMutexAndCloseZombie(sqlite3 *db){
1265   HashElem *i;                    /* Hash table iterator */
1266   int j;
1267 
1268   /* If there are outstanding sqlite3_stmt or sqlite3_backup objects
1269   ** or if the connection has not yet been closed by sqlite3_close_v2(),
1270   ** then just leave the mutex and return.
1271   */
1272   if( db->magic!=SQLITE_MAGIC_ZOMBIE || connectionIsBusy(db) ){
1273     sqlite3_mutex_leave(db->mutex);
1274     return;
1275   }
1276 
1277   /* If we reach this point, it means that the database connection has
1278   ** closed all sqlite3_stmt and sqlite3_backup objects and has been
1279   ** passed to sqlite3_close (meaning that it is a zombie).  Therefore,
1280   ** go ahead and free all resources.
1281   */
1282 
1283   /* If a transaction is open, roll it back. This also ensures that if
1284   ** any database schemas have been modified by an uncommitted transaction
1285   ** they are reset. And that the required b-tree mutex is held to make
1286   ** the pager rollback and schema reset an atomic operation. */
1287   sqlite3RollbackAll(db, SQLITE_OK);
1288 
1289   /* Free any outstanding Savepoint structures. */
1290   sqlite3CloseSavepoints(db);
1291 
1292   /* Close all database connections */
1293   for(j=0; j<db->nDb; j++){
1294     struct Db *pDb = &db->aDb[j];
1295     if( pDb->pBt ){
1296       sqlite3BtreeClose(pDb->pBt);
1297       pDb->pBt = 0;
1298       if( j!=1 ){
1299         pDb->pSchema = 0;
1300       }
1301     }
1302   }
1303   /* Clear the TEMP schema separately and last */
1304   if( db->aDb[1].pSchema ){
1305     sqlite3SchemaClear(db->aDb[1].pSchema);
1306   }
1307   sqlite3VtabUnlockList(db);
1308 
1309   /* Free up the array of auxiliary databases */
1310   sqlite3CollapseDatabaseArray(db);
1311   assert( db->nDb<=2 );
1312   assert( db->aDb==db->aDbStatic );
1313 
1314   /* Tell the code in notify.c that the connection no longer holds any
1315   ** locks and does not require any further unlock-notify callbacks.
1316   */
1317   sqlite3ConnectionClosed(db);
1318 
1319   for(i=sqliteHashFirst(&db->aFunc); i; i=sqliteHashNext(i)){
1320     FuncDef *pNext, *p;
1321     p = sqliteHashData(i);
1322     do{
1323       functionDestroy(db, p);
1324       pNext = p->pNext;
1325       sqlite3DbFree(db, p);
1326       p = pNext;
1327     }while( p );
1328   }
1329   sqlite3HashClear(&db->aFunc);
1330   for(i=sqliteHashFirst(&db->aCollSeq); i; i=sqliteHashNext(i)){
1331     CollSeq *pColl = (CollSeq *)sqliteHashData(i);
1332     /* Invoke any destructors registered for collation sequence user data. */
1333     for(j=0; j<3; j++){
1334       if( pColl[j].xDel ){
1335         pColl[j].xDel(pColl[j].pUser);
1336       }
1337     }
1338     sqlite3DbFree(db, pColl);
1339   }
1340   sqlite3HashClear(&db->aCollSeq);
1341 #ifndef SQLITE_OMIT_VIRTUALTABLE
1342   for(i=sqliteHashFirst(&db->aModule); i; i=sqliteHashNext(i)){
1343     Module *pMod = (Module *)sqliteHashData(i);
1344     sqlite3VtabEponymousTableClear(db, pMod);
1345     sqlite3VtabModuleUnref(db, pMod);
1346   }
1347   sqlite3HashClear(&db->aModule);
1348 #endif
1349 
1350   sqlite3Error(db, SQLITE_OK); /* Deallocates any cached error strings. */
1351   sqlite3ValueFree(db->pErr);
1352   sqlite3CloseExtensions(db);
1353 #if SQLITE_USER_AUTHENTICATION
1354   sqlite3_free(db->auth.zAuthUser);
1355   sqlite3_free(db->auth.zAuthPW);
1356 #endif
1357 
1358   db->magic = SQLITE_MAGIC_ERROR;
1359 
1360   /* The temp-database schema is allocated differently from the other schema
1361   ** objects (using sqliteMalloc() directly, instead of sqlite3BtreeSchema()).
1362   ** So it needs to be freed here. Todo: Why not roll the temp schema into
1363   ** the same sqliteMalloc() as the one that allocates the database
1364   ** structure?
1365   */
1366   sqlite3DbFree(db, db->aDb[1].pSchema);
1367   sqlite3_mutex_leave(db->mutex);
1368   db->magic = SQLITE_MAGIC_CLOSED;
1369   sqlite3_mutex_free(db->mutex);
1370   assert( sqlite3LookasideUsed(db,0)==0 );
1371   if( db->lookaside.bMalloced ){
1372     sqlite3_free(db->lookaside.pStart);
1373   }
1374   sqlite3_free(db);
1375 }
1376 
1377 /*
1378 ** Rollback all database files.  If tripCode is not SQLITE_OK, then
1379 ** any write cursors are invalidated ("tripped" - as in "tripping a circuit
1380 ** breaker") and made to return tripCode if there are any further
1381 ** attempts to use that cursor.  Read cursors remain open and valid
1382 ** but are "saved" in case the table pages are moved around.
1383 */
1384 void sqlite3RollbackAll(sqlite3 *db, int tripCode){
1385   int i;
1386   int inTrans = 0;
1387   int schemaChange;
1388   assert( sqlite3_mutex_held(db->mutex) );
1389   sqlite3BeginBenignMalloc();
1390 
1391   /* Obtain all b-tree mutexes before making any calls to BtreeRollback().
1392   ** This is important in case the transaction being rolled back has
1393   ** modified the database schema. If the b-tree mutexes are not taken
1394   ** here, then another shared-cache connection might sneak in between
1395   ** the database rollback and schema reset, which can cause false
1396   ** corruption reports in some cases.  */
1397   sqlite3BtreeEnterAll(db);
1398   schemaChange = (db->mDbFlags & DBFLAG_SchemaChange)!=0 && db->init.busy==0;
1399 
1400   for(i=0; i<db->nDb; i++){
1401     Btree *p = db->aDb[i].pBt;
1402     if( p ){
1403       if( sqlite3BtreeIsInTrans(p) ){
1404         inTrans = 1;
1405       }
1406       sqlite3BtreeRollback(p, tripCode, !schemaChange);
1407     }
1408   }
1409   sqlite3VtabRollback(db);
1410   sqlite3EndBenignMalloc();
1411 
1412   if( schemaChange ){
1413     sqlite3ExpirePreparedStatements(db, 0);
1414     sqlite3ResetAllSchemasOfConnection(db);
1415   }
1416   sqlite3BtreeLeaveAll(db);
1417 
1418   /* Any deferred constraint violations have now been resolved. */
1419   db->nDeferredCons = 0;
1420   db->nDeferredImmCons = 0;
1421   db->flags &= ~(u64)SQLITE_DeferFKs;
1422 
1423   /* If one has been configured, invoke the rollback-hook callback */
1424   if( db->xRollbackCallback && (inTrans || !db->autoCommit) ){
1425     db->xRollbackCallback(db->pRollbackArg);
1426   }
1427 }
1428 
1429 /*
1430 ** Return a static string containing the name corresponding to the error code
1431 ** specified in the argument.
1432 */
1433 #if defined(SQLITE_NEED_ERR_NAME)
1434 const char *sqlite3ErrName(int rc){
1435   const char *zName = 0;
1436   int i, origRc = rc;
1437   for(i=0; i<2 && zName==0; i++, rc &= 0xff){
1438     switch( rc ){
1439       case SQLITE_OK:                 zName = "SQLITE_OK";                break;
1440       case SQLITE_ERROR:              zName = "SQLITE_ERROR";             break;
1441       case SQLITE_ERROR_SNAPSHOT:     zName = "SQLITE_ERROR_SNAPSHOT";    break;
1442       case SQLITE_INTERNAL:           zName = "SQLITE_INTERNAL";          break;
1443       case SQLITE_PERM:               zName = "SQLITE_PERM";              break;
1444       case SQLITE_ABORT:              zName = "SQLITE_ABORT";             break;
1445       case SQLITE_ABORT_ROLLBACK:     zName = "SQLITE_ABORT_ROLLBACK";    break;
1446       case SQLITE_BUSY:               zName = "SQLITE_BUSY";              break;
1447       case SQLITE_BUSY_RECOVERY:      zName = "SQLITE_BUSY_RECOVERY";     break;
1448       case SQLITE_BUSY_SNAPSHOT:      zName = "SQLITE_BUSY_SNAPSHOT";     break;
1449       case SQLITE_LOCKED:             zName = "SQLITE_LOCKED";            break;
1450       case SQLITE_LOCKED_SHAREDCACHE: zName = "SQLITE_LOCKED_SHAREDCACHE";break;
1451       case SQLITE_NOMEM:              zName = "SQLITE_NOMEM";             break;
1452       case SQLITE_READONLY:           zName = "SQLITE_READONLY";          break;
1453       case SQLITE_READONLY_RECOVERY:  zName = "SQLITE_READONLY_RECOVERY"; break;
1454       case SQLITE_READONLY_CANTINIT:  zName = "SQLITE_READONLY_CANTINIT"; break;
1455       case SQLITE_READONLY_ROLLBACK:  zName = "SQLITE_READONLY_ROLLBACK"; break;
1456       case SQLITE_READONLY_DBMOVED:   zName = "SQLITE_READONLY_DBMOVED";  break;
1457       case SQLITE_READONLY_DIRECTORY: zName = "SQLITE_READONLY_DIRECTORY";break;
1458       case SQLITE_INTERRUPT:          zName = "SQLITE_INTERRUPT";         break;
1459       case SQLITE_IOERR:              zName = "SQLITE_IOERR";             break;
1460       case SQLITE_IOERR_READ:         zName = "SQLITE_IOERR_READ";        break;
1461       case SQLITE_IOERR_SHORT_READ:   zName = "SQLITE_IOERR_SHORT_READ";  break;
1462       case SQLITE_IOERR_WRITE:        zName = "SQLITE_IOERR_WRITE";       break;
1463       case SQLITE_IOERR_FSYNC:        zName = "SQLITE_IOERR_FSYNC";       break;
1464       case SQLITE_IOERR_DIR_FSYNC:    zName = "SQLITE_IOERR_DIR_FSYNC";   break;
1465       case SQLITE_IOERR_TRUNCATE:     zName = "SQLITE_IOERR_TRUNCATE";    break;
1466       case SQLITE_IOERR_FSTAT:        zName = "SQLITE_IOERR_FSTAT";       break;
1467       case SQLITE_IOERR_UNLOCK:       zName = "SQLITE_IOERR_UNLOCK";      break;
1468       case SQLITE_IOERR_RDLOCK:       zName = "SQLITE_IOERR_RDLOCK";      break;
1469       case SQLITE_IOERR_DELETE:       zName = "SQLITE_IOERR_DELETE";      break;
1470       case SQLITE_IOERR_NOMEM:        zName = "SQLITE_IOERR_NOMEM";       break;
1471       case SQLITE_IOERR_ACCESS:       zName = "SQLITE_IOERR_ACCESS";      break;
1472       case SQLITE_IOERR_CHECKRESERVEDLOCK:
1473                                 zName = "SQLITE_IOERR_CHECKRESERVEDLOCK"; break;
1474       case SQLITE_IOERR_LOCK:         zName = "SQLITE_IOERR_LOCK";        break;
1475       case SQLITE_IOERR_CLOSE:        zName = "SQLITE_IOERR_CLOSE";       break;
1476       case SQLITE_IOERR_DIR_CLOSE:    zName = "SQLITE_IOERR_DIR_CLOSE";   break;
1477       case SQLITE_IOERR_SHMOPEN:      zName = "SQLITE_IOERR_SHMOPEN";     break;
1478       case SQLITE_IOERR_SHMSIZE:      zName = "SQLITE_IOERR_SHMSIZE";     break;
1479       case SQLITE_IOERR_SHMLOCK:      zName = "SQLITE_IOERR_SHMLOCK";     break;
1480       case SQLITE_IOERR_SHMMAP:       zName = "SQLITE_IOERR_SHMMAP";      break;
1481       case SQLITE_IOERR_SEEK:         zName = "SQLITE_IOERR_SEEK";        break;
1482       case SQLITE_IOERR_DELETE_NOENT: zName = "SQLITE_IOERR_DELETE_NOENT";break;
1483       case SQLITE_IOERR_MMAP:         zName = "SQLITE_IOERR_MMAP";        break;
1484       case SQLITE_IOERR_GETTEMPPATH:  zName = "SQLITE_IOERR_GETTEMPPATH"; break;
1485       case SQLITE_IOERR_CONVPATH:     zName = "SQLITE_IOERR_CONVPATH";    break;
1486       case SQLITE_CORRUPT:            zName = "SQLITE_CORRUPT";           break;
1487       case SQLITE_CORRUPT_VTAB:       zName = "SQLITE_CORRUPT_VTAB";      break;
1488       case SQLITE_NOTFOUND:           zName = "SQLITE_NOTFOUND";          break;
1489       case SQLITE_FULL:               zName = "SQLITE_FULL";              break;
1490       case SQLITE_CANTOPEN:           zName = "SQLITE_CANTOPEN";          break;
1491       case SQLITE_CANTOPEN_NOTEMPDIR: zName = "SQLITE_CANTOPEN_NOTEMPDIR";break;
1492       case SQLITE_CANTOPEN_ISDIR:     zName = "SQLITE_CANTOPEN_ISDIR";    break;
1493       case SQLITE_CANTOPEN_FULLPATH:  zName = "SQLITE_CANTOPEN_FULLPATH"; break;
1494       case SQLITE_CANTOPEN_CONVPATH:  zName = "SQLITE_CANTOPEN_CONVPATH"; break;
1495       case SQLITE_CANTOPEN_SYMLINK:   zName = "SQLITE_CANTOPEN_SYMLINK";  break;
1496       case SQLITE_PROTOCOL:           zName = "SQLITE_PROTOCOL";          break;
1497       case SQLITE_EMPTY:              zName = "SQLITE_EMPTY";             break;
1498       case SQLITE_SCHEMA:             zName = "SQLITE_SCHEMA";            break;
1499       case SQLITE_TOOBIG:             zName = "SQLITE_TOOBIG";            break;
1500       case SQLITE_CONSTRAINT:         zName = "SQLITE_CONSTRAINT";        break;
1501       case SQLITE_CONSTRAINT_UNIQUE:  zName = "SQLITE_CONSTRAINT_UNIQUE"; break;
1502       case SQLITE_CONSTRAINT_TRIGGER: zName = "SQLITE_CONSTRAINT_TRIGGER";break;
1503       case SQLITE_CONSTRAINT_FOREIGNKEY:
1504                                 zName = "SQLITE_CONSTRAINT_FOREIGNKEY";   break;
1505       case SQLITE_CONSTRAINT_CHECK:   zName = "SQLITE_CONSTRAINT_CHECK";  break;
1506       case SQLITE_CONSTRAINT_PRIMARYKEY:
1507                                 zName = "SQLITE_CONSTRAINT_PRIMARYKEY";   break;
1508       case SQLITE_CONSTRAINT_NOTNULL: zName = "SQLITE_CONSTRAINT_NOTNULL";break;
1509       case SQLITE_CONSTRAINT_COMMITHOOK:
1510                                 zName = "SQLITE_CONSTRAINT_COMMITHOOK";   break;
1511       case SQLITE_CONSTRAINT_VTAB:    zName = "SQLITE_CONSTRAINT_VTAB";   break;
1512       case SQLITE_CONSTRAINT_FUNCTION:
1513                                 zName = "SQLITE_CONSTRAINT_FUNCTION";     break;
1514       case SQLITE_CONSTRAINT_ROWID:   zName = "SQLITE_CONSTRAINT_ROWID";  break;
1515       case SQLITE_MISMATCH:           zName = "SQLITE_MISMATCH";          break;
1516       case SQLITE_MISUSE:             zName = "SQLITE_MISUSE";            break;
1517       case SQLITE_NOLFS:              zName = "SQLITE_NOLFS";             break;
1518       case SQLITE_AUTH:               zName = "SQLITE_AUTH";              break;
1519       case SQLITE_FORMAT:             zName = "SQLITE_FORMAT";            break;
1520       case SQLITE_RANGE:              zName = "SQLITE_RANGE";             break;
1521       case SQLITE_NOTADB:             zName = "SQLITE_NOTADB";            break;
1522       case SQLITE_ROW:                zName = "SQLITE_ROW";               break;
1523       case SQLITE_NOTICE:             zName = "SQLITE_NOTICE";            break;
1524       case SQLITE_NOTICE_RECOVER_WAL: zName = "SQLITE_NOTICE_RECOVER_WAL";break;
1525       case SQLITE_NOTICE_RECOVER_ROLLBACK:
1526                                 zName = "SQLITE_NOTICE_RECOVER_ROLLBACK"; break;
1527       case SQLITE_WARNING:            zName = "SQLITE_WARNING";           break;
1528       case SQLITE_WARNING_AUTOINDEX:  zName = "SQLITE_WARNING_AUTOINDEX"; break;
1529       case SQLITE_DONE:               zName = "SQLITE_DONE";              break;
1530     }
1531   }
1532   if( zName==0 ){
1533     static char zBuf[50];
1534     sqlite3_snprintf(sizeof(zBuf), zBuf, "SQLITE_UNKNOWN(%d)", origRc);
1535     zName = zBuf;
1536   }
1537   return zName;
1538 }
1539 #endif
1540 
1541 /*
1542 ** Return a static string that describes the kind of error specified in the
1543 ** argument.
1544 */
1545 const char *sqlite3ErrStr(int rc){
1546   static const char* const aMsg[] = {
1547     /* SQLITE_OK          */ "not an error",
1548     /* SQLITE_ERROR       */ "SQL logic error",
1549     /* SQLITE_INTERNAL    */ 0,
1550     /* SQLITE_PERM        */ "access permission denied",
1551     /* SQLITE_ABORT       */ "query aborted",
1552     /* SQLITE_BUSY        */ "database is locked",
1553     /* SQLITE_LOCKED      */ "database table is locked",
1554     /* SQLITE_NOMEM       */ "out of memory",
1555     /* SQLITE_READONLY    */ "attempt to write a readonly database",
1556     /* SQLITE_INTERRUPT   */ "interrupted",
1557     /* SQLITE_IOERR       */ "disk I/O error",
1558     /* SQLITE_CORRUPT     */ "database disk image is malformed",
1559     /* SQLITE_NOTFOUND    */ "unknown operation",
1560     /* SQLITE_FULL        */ "database or disk is full",
1561     /* SQLITE_CANTOPEN    */ "unable to open database file",
1562     /* SQLITE_PROTOCOL    */ "locking protocol",
1563     /* SQLITE_EMPTY       */ 0,
1564     /* SQLITE_SCHEMA      */ "database schema has changed",
1565     /* SQLITE_TOOBIG      */ "string or blob too big",
1566     /* SQLITE_CONSTRAINT  */ "constraint failed",
1567     /* SQLITE_MISMATCH    */ "datatype mismatch",
1568     /* SQLITE_MISUSE      */ "bad parameter or other API misuse",
1569 #ifdef SQLITE_DISABLE_LFS
1570     /* SQLITE_NOLFS       */ "large file support is disabled",
1571 #else
1572     /* SQLITE_NOLFS       */ 0,
1573 #endif
1574     /* SQLITE_AUTH        */ "authorization denied",
1575     /* SQLITE_FORMAT      */ 0,
1576     /* SQLITE_RANGE       */ "column index out of range",
1577     /* SQLITE_NOTADB      */ "file is not a database",
1578     /* SQLITE_NOTICE      */ "notification message",
1579     /* SQLITE_WARNING     */ "warning message",
1580   };
1581   const char *zErr = "unknown error";
1582   switch( rc ){
1583     case SQLITE_ABORT_ROLLBACK: {
1584       zErr = "abort due to ROLLBACK";
1585       break;
1586     }
1587     case SQLITE_ROW: {
1588       zErr = "another row available";
1589       break;
1590     }
1591     case SQLITE_DONE: {
1592       zErr = "no more rows available";
1593       break;
1594     }
1595     default: {
1596       rc &= 0xff;
1597       if( ALWAYS(rc>=0) && rc<ArraySize(aMsg) && aMsg[rc]!=0 ){
1598         zErr = aMsg[rc];
1599       }
1600       break;
1601     }
1602   }
1603   return zErr;
1604 }
1605 
1606 /*
1607 ** This routine implements a busy callback that sleeps and tries
1608 ** again until a timeout value is reached.  The timeout value is
1609 ** an integer number of milliseconds passed in as the first
1610 ** argument.
1611 **
1612 ** Return non-zero to retry the lock.  Return zero to stop trying
1613 ** and cause SQLite to return SQLITE_BUSY.
1614 */
1615 static int sqliteDefaultBusyCallback(
1616   void *ptr,               /* Database connection */
1617   int count                /* Number of times table has been busy */
1618 ){
1619 #if SQLITE_OS_WIN || HAVE_USLEEP
1620   /* This case is for systems that have support for sleeping for fractions of
1621   ** a second.  Examples:  All windows systems, unix systems with usleep() */
1622   static const u8 delays[] =
1623      { 1, 2, 5, 10, 15, 20, 25, 25,  25,  50,  50, 100 };
1624   static const u8 totals[] =
1625      { 0, 1, 3,  8, 18, 33, 53, 78, 103, 128, 178, 228 };
1626 # define NDELAY ArraySize(delays)
1627   sqlite3 *db = (sqlite3 *)ptr;
1628   int tmout = db->busyTimeout;
1629   int delay, prior;
1630 
1631   assert( count>=0 );
1632   if( count < NDELAY ){
1633     delay = delays[count];
1634     prior = totals[count];
1635   }else{
1636     delay = delays[NDELAY-1];
1637     prior = totals[NDELAY-1] + delay*(count-(NDELAY-1));
1638   }
1639   if( prior + delay > tmout ){
1640     delay = tmout - prior;
1641     if( delay<=0 ) return 0;
1642   }
1643   sqlite3OsSleep(db->pVfs, delay*1000);
1644   return 1;
1645 #else
1646   /* This case for unix systems that lack usleep() support.  Sleeping
1647   ** must be done in increments of whole seconds */
1648   sqlite3 *db = (sqlite3 *)ptr;
1649   int tmout = ((sqlite3 *)ptr)->busyTimeout;
1650   if( (count+1)*1000 > tmout ){
1651     return 0;
1652   }
1653   sqlite3OsSleep(db->pVfs, 1000000);
1654   return 1;
1655 #endif
1656 }
1657 
1658 /*
1659 ** Invoke the given busy handler.
1660 **
1661 ** This routine is called when an operation failed to acquire a
1662 ** lock on VFS file pFile.
1663 **
1664 ** If this routine returns non-zero, the lock is retried.  If it
1665 ** returns 0, the operation aborts with an SQLITE_BUSY error.
1666 */
1667 int sqlite3InvokeBusyHandler(BusyHandler *p){
1668   int rc;
1669   if( p->xBusyHandler==0 || p->nBusy<0 ) return 0;
1670   rc = p->xBusyHandler(p->pBusyArg, p->nBusy);
1671   if( rc==0 ){
1672     p->nBusy = -1;
1673   }else{
1674     p->nBusy++;
1675   }
1676   return rc;
1677 }
1678 
1679 /*
1680 ** This routine sets the busy callback for an Sqlite database to the
1681 ** given callback function with the given argument.
1682 */
1683 int sqlite3_busy_handler(
1684   sqlite3 *db,
1685   int (*xBusy)(void*,int),
1686   void *pArg
1687 ){
1688 #ifdef SQLITE_ENABLE_API_ARMOR
1689   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
1690 #endif
1691   sqlite3_mutex_enter(db->mutex);
1692   db->busyHandler.xBusyHandler = xBusy;
1693   db->busyHandler.pBusyArg = pArg;
1694   db->busyHandler.nBusy = 0;
1695   db->busyTimeout = 0;
1696   sqlite3_mutex_leave(db->mutex);
1697   return SQLITE_OK;
1698 }
1699 
1700 #ifndef SQLITE_OMIT_PROGRESS_CALLBACK
1701 /*
1702 ** This routine sets the progress callback for an Sqlite database to the
1703 ** given callback function with the given argument. The progress callback will
1704 ** be invoked every nOps opcodes.
1705 */
1706 void sqlite3_progress_handler(
1707   sqlite3 *db,
1708   int nOps,
1709   int (*xProgress)(void*),
1710   void *pArg
1711 ){
1712 #ifdef SQLITE_ENABLE_API_ARMOR
1713   if( !sqlite3SafetyCheckOk(db) ){
1714     (void)SQLITE_MISUSE_BKPT;
1715     return;
1716   }
1717 #endif
1718   sqlite3_mutex_enter(db->mutex);
1719   if( nOps>0 ){
1720     db->xProgress = xProgress;
1721     db->nProgressOps = (unsigned)nOps;
1722     db->pProgressArg = pArg;
1723   }else{
1724     db->xProgress = 0;
1725     db->nProgressOps = 0;
1726     db->pProgressArg = 0;
1727   }
1728   sqlite3_mutex_leave(db->mutex);
1729 }
1730 #endif
1731 
1732 
1733 /*
1734 ** This routine installs a default busy handler that waits for the
1735 ** specified number of milliseconds before returning 0.
1736 */
1737 int sqlite3_busy_timeout(sqlite3 *db, int ms){
1738 #ifdef SQLITE_ENABLE_API_ARMOR
1739   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
1740 #endif
1741   if( ms>0 ){
1742     sqlite3_busy_handler(db, (int(*)(void*,int))sqliteDefaultBusyCallback,
1743                              (void*)db);
1744     db->busyTimeout = ms;
1745   }else{
1746     sqlite3_busy_handler(db, 0, 0);
1747   }
1748   return SQLITE_OK;
1749 }
1750 
1751 /*
1752 ** Cause any pending operation to stop at its earliest opportunity.
1753 */
1754 void sqlite3_interrupt(sqlite3 *db){
1755 #ifdef SQLITE_ENABLE_API_ARMOR
1756   if( !sqlite3SafetyCheckOk(db) && (db==0 || db->magic!=SQLITE_MAGIC_ZOMBIE) ){
1757     (void)SQLITE_MISUSE_BKPT;
1758     return;
1759   }
1760 #endif
1761   AtomicStore(&db->u1.isInterrupted, 1);
1762 }
1763 
1764 
1765 /*
1766 ** This function is exactly the same as sqlite3_create_function(), except
1767 ** that it is designed to be called by internal code. The difference is
1768 ** that if a malloc() fails in sqlite3_create_function(), an error code
1769 ** is returned and the mallocFailed flag cleared.
1770 */
1771 int sqlite3CreateFunc(
1772   sqlite3 *db,
1773   const char *zFunctionName,
1774   int nArg,
1775   int enc,
1776   void *pUserData,
1777   void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
1778   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
1779   void (*xFinal)(sqlite3_context*),
1780   void (*xValue)(sqlite3_context*),
1781   void (*xInverse)(sqlite3_context*,int,sqlite3_value **),
1782   FuncDestructor *pDestructor
1783 ){
1784   FuncDef *p;
1785   int nName;
1786   int extraFlags;
1787 
1788   assert( sqlite3_mutex_held(db->mutex) );
1789   assert( xValue==0 || xSFunc==0 );
1790   if( zFunctionName==0                /* Must have a valid name */
1791    || (xSFunc!=0 && xFinal!=0)        /* Not both xSFunc and xFinal */
1792    || ((xFinal==0)!=(xStep==0))       /* Both or neither of xFinal and xStep */
1793    || ((xValue==0)!=(xInverse==0))    /* Both or neither of xValue, xInverse */
1794    || (nArg<-1 || nArg>SQLITE_MAX_FUNCTION_ARG)
1795    || (255<(nName = sqlite3Strlen30( zFunctionName)))
1796   ){
1797     return SQLITE_MISUSE_BKPT;
1798   }
1799 
1800   assert( SQLITE_FUNC_CONSTANT==SQLITE_DETERMINISTIC );
1801   assert( SQLITE_FUNC_DIRECT==SQLITE_DIRECTONLY );
1802   extraFlags = enc &  (SQLITE_DETERMINISTIC|SQLITE_DIRECTONLY|
1803                        SQLITE_SUBTYPE|SQLITE_INNOCUOUS);
1804   enc &= (SQLITE_FUNC_ENCMASK|SQLITE_ANY);
1805 
1806   /* The SQLITE_INNOCUOUS flag is the same bit as SQLITE_FUNC_UNSAFE.  But
1807   ** the meaning is inverted.  So flip the bit. */
1808   assert( SQLITE_FUNC_UNSAFE==SQLITE_INNOCUOUS );
1809   extraFlags ^= SQLITE_FUNC_UNSAFE;
1810 
1811 
1812 #ifndef SQLITE_OMIT_UTF16
1813   /* If SQLITE_UTF16 is specified as the encoding type, transform this
1814   ** to one of SQLITE_UTF16LE or SQLITE_UTF16BE using the
1815   ** SQLITE_UTF16NATIVE macro. SQLITE_UTF16 is not used internally.
1816   **
1817   ** If SQLITE_ANY is specified, add three versions of the function
1818   ** to the hash table.
1819   */
1820   if( enc==SQLITE_UTF16 ){
1821     enc = SQLITE_UTF16NATIVE;
1822   }else if( enc==SQLITE_ANY ){
1823     int rc;
1824     rc = sqlite3CreateFunc(db, zFunctionName, nArg,
1825          (SQLITE_UTF8|extraFlags)^SQLITE_FUNC_UNSAFE,
1826          pUserData, xSFunc, xStep, xFinal, xValue, xInverse, pDestructor);
1827     if( rc==SQLITE_OK ){
1828       rc = sqlite3CreateFunc(db, zFunctionName, nArg,
1829            (SQLITE_UTF16LE|extraFlags)^SQLITE_FUNC_UNSAFE,
1830            pUserData, xSFunc, xStep, xFinal, xValue, xInverse, pDestructor);
1831     }
1832     if( rc!=SQLITE_OK ){
1833       return rc;
1834     }
1835     enc = SQLITE_UTF16BE;
1836   }
1837 #else
1838   enc = SQLITE_UTF8;
1839 #endif
1840 
1841   /* Check if an existing function is being overridden or deleted. If so,
1842   ** and there are active VMs, then return SQLITE_BUSY. If a function
1843   ** is being overridden/deleted but there are no active VMs, allow the
1844   ** operation to continue but invalidate all precompiled statements.
1845   */
1846   p = sqlite3FindFunction(db, zFunctionName, nArg, (u8)enc, 0);
1847   if( p && (p->funcFlags & SQLITE_FUNC_ENCMASK)==(u32)enc && p->nArg==nArg ){
1848     if( db->nVdbeActive ){
1849       sqlite3ErrorWithMsg(db, SQLITE_BUSY,
1850         "unable to delete/modify user-function due to active statements");
1851       assert( !db->mallocFailed );
1852       return SQLITE_BUSY;
1853     }else{
1854       sqlite3ExpirePreparedStatements(db, 0);
1855     }
1856   }
1857 
1858   p = sqlite3FindFunction(db, zFunctionName, nArg, (u8)enc, 1);
1859   assert(p || db->mallocFailed);
1860   if( !p ){
1861     return SQLITE_NOMEM_BKPT;
1862   }
1863 
1864   /* If an older version of the function with a configured destructor is
1865   ** being replaced invoke the destructor function here. */
1866   functionDestroy(db, p);
1867 
1868   if( pDestructor ){
1869     pDestructor->nRef++;
1870   }
1871   p->u.pDestructor = pDestructor;
1872   p->funcFlags = (p->funcFlags & SQLITE_FUNC_ENCMASK) | extraFlags;
1873   testcase( p->funcFlags & SQLITE_DETERMINISTIC );
1874   testcase( p->funcFlags & SQLITE_DIRECTONLY );
1875   p->xSFunc = xSFunc ? xSFunc : xStep;
1876   p->xFinalize = xFinal;
1877   p->xValue = xValue;
1878   p->xInverse = xInverse;
1879   p->pUserData = pUserData;
1880   p->nArg = (u16)nArg;
1881   return SQLITE_OK;
1882 }
1883 
1884 /*
1885 ** Worker function used by utf-8 APIs that create new functions:
1886 **
1887 **    sqlite3_create_function()
1888 **    sqlite3_create_function_v2()
1889 **    sqlite3_create_window_function()
1890 */
1891 static int createFunctionApi(
1892   sqlite3 *db,
1893   const char *zFunc,
1894   int nArg,
1895   int enc,
1896   void *p,
1897   void (*xSFunc)(sqlite3_context*,int,sqlite3_value**),
1898   void (*xStep)(sqlite3_context*,int,sqlite3_value**),
1899   void (*xFinal)(sqlite3_context*),
1900   void (*xValue)(sqlite3_context*),
1901   void (*xInverse)(sqlite3_context*,int,sqlite3_value**),
1902   void(*xDestroy)(void*)
1903 ){
1904   int rc = SQLITE_ERROR;
1905   FuncDestructor *pArg = 0;
1906 
1907 #ifdef SQLITE_ENABLE_API_ARMOR
1908   if( !sqlite3SafetyCheckOk(db) ){
1909     return SQLITE_MISUSE_BKPT;
1910   }
1911 #endif
1912   sqlite3_mutex_enter(db->mutex);
1913   if( xDestroy ){
1914     pArg = (FuncDestructor *)sqlite3Malloc(sizeof(FuncDestructor));
1915     if( !pArg ){
1916       sqlite3OomFault(db);
1917       xDestroy(p);
1918       goto out;
1919     }
1920     pArg->nRef = 0;
1921     pArg->xDestroy = xDestroy;
1922     pArg->pUserData = p;
1923   }
1924   rc = sqlite3CreateFunc(db, zFunc, nArg, enc, p,
1925       xSFunc, xStep, xFinal, xValue, xInverse, pArg
1926   );
1927   if( pArg && pArg->nRef==0 ){
1928     assert( rc!=SQLITE_OK );
1929     xDestroy(p);
1930     sqlite3_free(pArg);
1931   }
1932 
1933  out:
1934   rc = sqlite3ApiExit(db, rc);
1935   sqlite3_mutex_leave(db->mutex);
1936   return rc;
1937 }
1938 
1939 /*
1940 ** Create new user functions.
1941 */
1942 int sqlite3_create_function(
1943   sqlite3 *db,
1944   const char *zFunc,
1945   int nArg,
1946   int enc,
1947   void *p,
1948   void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
1949   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
1950   void (*xFinal)(sqlite3_context*)
1951 ){
1952   return createFunctionApi(db, zFunc, nArg, enc, p, xSFunc, xStep,
1953                                     xFinal, 0, 0, 0);
1954 }
1955 int sqlite3_create_function_v2(
1956   sqlite3 *db,
1957   const char *zFunc,
1958   int nArg,
1959   int enc,
1960   void *p,
1961   void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
1962   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
1963   void (*xFinal)(sqlite3_context*),
1964   void (*xDestroy)(void *)
1965 ){
1966   return createFunctionApi(db, zFunc, nArg, enc, p, xSFunc, xStep,
1967                                     xFinal, 0, 0, xDestroy);
1968 }
1969 int sqlite3_create_window_function(
1970   sqlite3 *db,
1971   const char *zFunc,
1972   int nArg,
1973   int enc,
1974   void *p,
1975   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
1976   void (*xFinal)(sqlite3_context*),
1977   void (*xValue)(sqlite3_context*),
1978   void (*xInverse)(sqlite3_context*,int,sqlite3_value **),
1979   void (*xDestroy)(void *)
1980 ){
1981   return createFunctionApi(db, zFunc, nArg, enc, p, 0, xStep,
1982                                     xFinal, xValue, xInverse, xDestroy);
1983 }
1984 
1985 #ifndef SQLITE_OMIT_UTF16
1986 int sqlite3_create_function16(
1987   sqlite3 *db,
1988   const void *zFunctionName,
1989   int nArg,
1990   int eTextRep,
1991   void *p,
1992   void (*xSFunc)(sqlite3_context*,int,sqlite3_value**),
1993   void (*xStep)(sqlite3_context*,int,sqlite3_value**),
1994   void (*xFinal)(sqlite3_context*)
1995 ){
1996   int rc;
1997   char *zFunc8;
1998 
1999 #ifdef SQLITE_ENABLE_API_ARMOR
2000   if( !sqlite3SafetyCheckOk(db) || zFunctionName==0 ) return SQLITE_MISUSE_BKPT;
2001 #endif
2002   sqlite3_mutex_enter(db->mutex);
2003   assert( !db->mallocFailed );
2004   zFunc8 = sqlite3Utf16to8(db, zFunctionName, -1, SQLITE_UTF16NATIVE);
2005   rc = sqlite3CreateFunc(db, zFunc8, nArg, eTextRep, p, xSFunc,xStep,xFinal,0,0,0);
2006   sqlite3DbFree(db, zFunc8);
2007   rc = sqlite3ApiExit(db, rc);
2008   sqlite3_mutex_leave(db->mutex);
2009   return rc;
2010 }
2011 #endif
2012 
2013 
2014 /*
2015 ** The following is the implementation of an SQL function that always
2016 ** fails with an error message stating that the function is used in the
2017 ** wrong context.  The sqlite3_overload_function() API might construct
2018 ** SQL function that use this routine so that the functions will exist
2019 ** for name resolution but are actually overloaded by the xFindFunction
2020 ** method of virtual tables.
2021 */
2022 static void sqlite3InvalidFunction(
2023   sqlite3_context *context,  /* The function calling context */
2024   int NotUsed,               /* Number of arguments to the function */
2025   sqlite3_value **NotUsed2   /* Value of each argument */
2026 ){
2027   const char *zName = (const char*)sqlite3_user_data(context);
2028   char *zErr;
2029   UNUSED_PARAMETER2(NotUsed, NotUsed2);
2030   zErr = sqlite3_mprintf(
2031       "unable to use function %s in the requested context", zName);
2032   sqlite3_result_error(context, zErr, -1);
2033   sqlite3_free(zErr);
2034 }
2035 
2036 /*
2037 ** Declare that a function has been overloaded by a virtual table.
2038 **
2039 ** If the function already exists as a regular global function, then
2040 ** this routine is a no-op.  If the function does not exist, then create
2041 ** a new one that always throws a run-time error.
2042 **
2043 ** When virtual tables intend to provide an overloaded function, they
2044 ** should call this routine to make sure the global function exists.
2045 ** A global function must exist in order for name resolution to work
2046 ** properly.
2047 */
2048 int sqlite3_overload_function(
2049   sqlite3 *db,
2050   const char *zName,
2051   int nArg
2052 ){
2053   int rc;
2054   char *zCopy;
2055 
2056 #ifdef SQLITE_ENABLE_API_ARMOR
2057   if( !sqlite3SafetyCheckOk(db) || zName==0 || nArg<-2 ){
2058     return SQLITE_MISUSE_BKPT;
2059   }
2060 #endif
2061   sqlite3_mutex_enter(db->mutex);
2062   rc = sqlite3FindFunction(db, zName, nArg, SQLITE_UTF8, 0)!=0;
2063   sqlite3_mutex_leave(db->mutex);
2064   if( rc ) return SQLITE_OK;
2065   zCopy = sqlite3_mprintf(zName);
2066   if( zCopy==0 ) return SQLITE_NOMEM;
2067   return sqlite3_create_function_v2(db, zName, nArg, SQLITE_UTF8,
2068                            zCopy, sqlite3InvalidFunction, 0, 0, sqlite3_free);
2069 }
2070 
2071 #ifndef SQLITE_OMIT_TRACE
2072 /*
2073 ** Register a trace function.  The pArg from the previously registered trace
2074 ** is returned.
2075 **
2076 ** A NULL trace function means that no tracing is executes.  A non-NULL
2077 ** trace is a pointer to a function that is invoked at the start of each
2078 ** SQL statement.
2079 */
2080 #ifndef SQLITE_OMIT_DEPRECATED
2081 void *sqlite3_trace(sqlite3 *db, void(*xTrace)(void*,const char*), void *pArg){
2082   void *pOld;
2083 
2084 #ifdef SQLITE_ENABLE_API_ARMOR
2085   if( !sqlite3SafetyCheckOk(db) ){
2086     (void)SQLITE_MISUSE_BKPT;
2087     return 0;
2088   }
2089 #endif
2090   sqlite3_mutex_enter(db->mutex);
2091   pOld = db->pTraceArg;
2092   db->mTrace = xTrace ? SQLITE_TRACE_LEGACY : 0;
2093   db->xTrace = (int(*)(u32,void*,void*,void*))xTrace;
2094   db->pTraceArg = pArg;
2095   sqlite3_mutex_leave(db->mutex);
2096   return pOld;
2097 }
2098 #endif /* SQLITE_OMIT_DEPRECATED */
2099 
2100 /* Register a trace callback using the version-2 interface.
2101 */
2102 int sqlite3_trace_v2(
2103   sqlite3 *db,                               /* Trace this connection */
2104   unsigned mTrace,                           /* Mask of events to be traced */
2105   int(*xTrace)(unsigned,void*,void*,void*),  /* Callback to invoke */
2106   void *pArg                                 /* Context */
2107 ){
2108 #ifdef SQLITE_ENABLE_API_ARMOR
2109   if( !sqlite3SafetyCheckOk(db) ){
2110     return SQLITE_MISUSE_BKPT;
2111   }
2112 #endif
2113   sqlite3_mutex_enter(db->mutex);
2114   if( mTrace==0 ) xTrace = 0;
2115   if( xTrace==0 ) mTrace = 0;
2116   db->mTrace = mTrace;
2117   db->xTrace = xTrace;
2118   db->pTraceArg = pArg;
2119   sqlite3_mutex_leave(db->mutex);
2120   return SQLITE_OK;
2121 }
2122 
2123 #ifndef SQLITE_OMIT_DEPRECATED
2124 /*
2125 ** Register a profile function.  The pArg from the previously registered
2126 ** profile function is returned.
2127 **
2128 ** A NULL profile function means that no profiling is executes.  A non-NULL
2129 ** profile is a pointer to a function that is invoked at the conclusion of
2130 ** each SQL statement that is run.
2131 */
2132 void *sqlite3_profile(
2133   sqlite3 *db,
2134   void (*xProfile)(void*,const char*,sqlite_uint64),
2135   void *pArg
2136 ){
2137   void *pOld;
2138 
2139 #ifdef SQLITE_ENABLE_API_ARMOR
2140   if( !sqlite3SafetyCheckOk(db) ){
2141     (void)SQLITE_MISUSE_BKPT;
2142     return 0;
2143   }
2144 #endif
2145   sqlite3_mutex_enter(db->mutex);
2146   pOld = db->pProfileArg;
2147   db->xProfile = xProfile;
2148   db->pProfileArg = pArg;
2149   db->mTrace &= SQLITE_TRACE_NONLEGACY_MASK;
2150   if( db->xProfile ) db->mTrace |= SQLITE_TRACE_XPROFILE;
2151   sqlite3_mutex_leave(db->mutex);
2152   return pOld;
2153 }
2154 #endif /* SQLITE_OMIT_DEPRECATED */
2155 #endif /* SQLITE_OMIT_TRACE */
2156 
2157 /*
2158 ** Register a function to be invoked when a transaction commits.
2159 ** If the invoked function returns non-zero, then the commit becomes a
2160 ** rollback.
2161 */
2162 void *sqlite3_commit_hook(
2163   sqlite3 *db,              /* Attach the hook to this database */
2164   int (*xCallback)(void*),  /* Function to invoke on each commit */
2165   void *pArg                /* Argument to the function */
2166 ){
2167   void *pOld;
2168 
2169 #ifdef SQLITE_ENABLE_API_ARMOR
2170   if( !sqlite3SafetyCheckOk(db) ){
2171     (void)SQLITE_MISUSE_BKPT;
2172     return 0;
2173   }
2174 #endif
2175   sqlite3_mutex_enter(db->mutex);
2176   pOld = db->pCommitArg;
2177   db->xCommitCallback = xCallback;
2178   db->pCommitArg = pArg;
2179   sqlite3_mutex_leave(db->mutex);
2180   return pOld;
2181 }
2182 
2183 /*
2184 ** Register a callback to be invoked each time a row is updated,
2185 ** inserted or deleted using this database connection.
2186 */
2187 void *sqlite3_update_hook(
2188   sqlite3 *db,              /* Attach the hook to this database */
2189   void (*xCallback)(void*,int,char const *,char const *,sqlite_int64),
2190   void *pArg                /* Argument to the function */
2191 ){
2192   void *pRet;
2193 
2194 #ifdef SQLITE_ENABLE_API_ARMOR
2195   if( !sqlite3SafetyCheckOk(db) ){
2196     (void)SQLITE_MISUSE_BKPT;
2197     return 0;
2198   }
2199 #endif
2200   sqlite3_mutex_enter(db->mutex);
2201   pRet = db->pUpdateArg;
2202   db->xUpdateCallback = xCallback;
2203   db->pUpdateArg = pArg;
2204   sqlite3_mutex_leave(db->mutex);
2205   return pRet;
2206 }
2207 
2208 /*
2209 ** Register a callback to be invoked each time a transaction is rolled
2210 ** back by this database connection.
2211 */
2212 void *sqlite3_rollback_hook(
2213   sqlite3 *db,              /* Attach the hook to this database */
2214   void (*xCallback)(void*), /* Callback function */
2215   void *pArg                /* Argument to the function */
2216 ){
2217   void *pRet;
2218 
2219 #ifdef SQLITE_ENABLE_API_ARMOR
2220   if( !sqlite3SafetyCheckOk(db) ){
2221     (void)SQLITE_MISUSE_BKPT;
2222     return 0;
2223   }
2224 #endif
2225   sqlite3_mutex_enter(db->mutex);
2226   pRet = db->pRollbackArg;
2227   db->xRollbackCallback = xCallback;
2228   db->pRollbackArg = pArg;
2229   sqlite3_mutex_leave(db->mutex);
2230   return pRet;
2231 }
2232 
2233 #ifdef SQLITE_ENABLE_PREUPDATE_HOOK
2234 /*
2235 ** Register a callback to be invoked each time a row is updated,
2236 ** inserted or deleted using this database connection.
2237 */
2238 void *sqlite3_preupdate_hook(
2239   sqlite3 *db,              /* Attach the hook to this database */
2240   void(*xCallback)(         /* Callback function */
2241     void*,sqlite3*,int,char const*,char const*,sqlite3_int64,sqlite3_int64),
2242   void *pArg                /* First callback argument */
2243 ){
2244   void *pRet;
2245   sqlite3_mutex_enter(db->mutex);
2246   pRet = db->pPreUpdateArg;
2247   db->xPreUpdateCallback = xCallback;
2248   db->pPreUpdateArg = pArg;
2249   sqlite3_mutex_leave(db->mutex);
2250   return pRet;
2251 }
2252 #endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
2253 
2254 #ifndef SQLITE_OMIT_WAL
2255 /*
2256 ** The sqlite3_wal_hook() callback registered by sqlite3_wal_autocheckpoint().
2257 ** Invoke sqlite3_wal_checkpoint if the number of frames in the log file
2258 ** is greater than sqlite3.pWalArg cast to an integer (the value configured by
2259 ** wal_autocheckpoint()).
2260 */
2261 int sqlite3WalDefaultHook(
2262   void *pClientData,     /* Argument */
2263   sqlite3 *db,           /* Connection */
2264   const char *zDb,       /* Database */
2265   int nFrame             /* Size of WAL */
2266 ){
2267   if( nFrame>=SQLITE_PTR_TO_INT(pClientData) ){
2268     sqlite3BeginBenignMalloc();
2269     sqlite3_wal_checkpoint(db, zDb);
2270     sqlite3EndBenignMalloc();
2271   }
2272   return SQLITE_OK;
2273 }
2274 #endif /* SQLITE_OMIT_WAL */
2275 
2276 /*
2277 ** Configure an sqlite3_wal_hook() callback to automatically checkpoint
2278 ** a database after committing a transaction if there are nFrame or
2279 ** more frames in the log file. Passing zero or a negative value as the
2280 ** nFrame parameter disables automatic checkpoints entirely.
2281 **
2282 ** The callback registered by this function replaces any existing callback
2283 ** registered using sqlite3_wal_hook(). Likewise, registering a callback
2284 ** using sqlite3_wal_hook() disables the automatic checkpoint mechanism
2285 ** configured by this function.
2286 */
2287 int sqlite3_wal_autocheckpoint(sqlite3 *db, int nFrame){
2288 #ifdef SQLITE_OMIT_WAL
2289   UNUSED_PARAMETER(db);
2290   UNUSED_PARAMETER(nFrame);
2291 #else
2292 #ifdef SQLITE_ENABLE_API_ARMOR
2293   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
2294 #endif
2295   if( nFrame>0 ){
2296     sqlite3_wal_hook(db, sqlite3WalDefaultHook, SQLITE_INT_TO_PTR(nFrame));
2297   }else{
2298     sqlite3_wal_hook(db, 0, 0);
2299   }
2300 #endif
2301   return SQLITE_OK;
2302 }
2303 
2304 /*
2305 ** Register a callback to be invoked each time a transaction is written
2306 ** into the write-ahead-log by this database connection.
2307 */
2308 void *sqlite3_wal_hook(
2309   sqlite3 *db,                    /* Attach the hook to this db handle */
2310   int(*xCallback)(void *, sqlite3*, const char*, int),
2311   void *pArg                      /* First argument passed to xCallback() */
2312 ){
2313 #ifndef SQLITE_OMIT_WAL
2314   void *pRet;
2315 #ifdef SQLITE_ENABLE_API_ARMOR
2316   if( !sqlite3SafetyCheckOk(db) ){
2317     (void)SQLITE_MISUSE_BKPT;
2318     return 0;
2319   }
2320 #endif
2321   sqlite3_mutex_enter(db->mutex);
2322   pRet = db->pWalArg;
2323   db->xWalCallback = xCallback;
2324   db->pWalArg = pArg;
2325   sqlite3_mutex_leave(db->mutex);
2326   return pRet;
2327 #else
2328   return 0;
2329 #endif
2330 }
2331 
2332 /*
2333 ** Checkpoint database zDb.
2334 */
2335 int sqlite3_wal_checkpoint_v2(
2336   sqlite3 *db,                    /* Database handle */
2337   const char *zDb,                /* Name of attached database (or NULL) */
2338   int eMode,                      /* SQLITE_CHECKPOINT_* value */
2339   int *pnLog,                     /* OUT: Size of WAL log in frames */
2340   int *pnCkpt                     /* OUT: Total number of frames checkpointed */
2341 ){
2342 #ifdef SQLITE_OMIT_WAL
2343   return SQLITE_OK;
2344 #else
2345   int rc;                         /* Return code */
2346   int iDb = SQLITE_MAX_ATTACHED;  /* sqlite3.aDb[] index of db to checkpoint */
2347 
2348 #ifdef SQLITE_ENABLE_API_ARMOR
2349   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
2350 #endif
2351 
2352   /* Initialize the output variables to -1 in case an error occurs. */
2353   if( pnLog ) *pnLog = -1;
2354   if( pnCkpt ) *pnCkpt = -1;
2355 
2356   assert( SQLITE_CHECKPOINT_PASSIVE==0 );
2357   assert( SQLITE_CHECKPOINT_FULL==1 );
2358   assert( SQLITE_CHECKPOINT_RESTART==2 );
2359   assert( SQLITE_CHECKPOINT_TRUNCATE==3 );
2360   if( eMode<SQLITE_CHECKPOINT_PASSIVE || eMode>SQLITE_CHECKPOINT_TRUNCATE ){
2361     /* EVIDENCE-OF: R-03996-12088 The M parameter must be a valid checkpoint
2362     ** mode: */
2363     return SQLITE_MISUSE;
2364   }
2365 
2366   sqlite3_mutex_enter(db->mutex);
2367   if( zDb && zDb[0] ){
2368     iDb = sqlite3FindDbName(db, zDb);
2369   }
2370   if( iDb<0 ){
2371     rc = SQLITE_ERROR;
2372     sqlite3ErrorWithMsg(db, SQLITE_ERROR, "unknown database: %s", zDb);
2373   }else{
2374     db->busyHandler.nBusy = 0;
2375     rc = sqlite3Checkpoint(db, iDb, eMode, pnLog, pnCkpt);
2376     sqlite3Error(db, rc);
2377   }
2378   rc = sqlite3ApiExit(db, rc);
2379 
2380   /* If there are no active statements, clear the interrupt flag at this
2381   ** point.  */
2382   if( db->nVdbeActive==0 ){
2383     AtomicStore(&db->u1.isInterrupted, 0);
2384   }
2385 
2386   sqlite3_mutex_leave(db->mutex);
2387   return rc;
2388 #endif
2389 }
2390 
2391 
2392 /*
2393 ** Checkpoint database zDb. If zDb is NULL, or if the buffer zDb points
2394 ** to contains a zero-length string, all attached databases are
2395 ** checkpointed.
2396 */
2397 int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb){
2398   /* EVIDENCE-OF: R-41613-20553 The sqlite3_wal_checkpoint(D,X) is equivalent to
2399   ** sqlite3_wal_checkpoint_v2(D,X,SQLITE_CHECKPOINT_PASSIVE,0,0). */
2400   return sqlite3_wal_checkpoint_v2(db,zDb,SQLITE_CHECKPOINT_PASSIVE,0,0);
2401 }
2402 
2403 #ifndef SQLITE_OMIT_WAL
2404 /*
2405 ** Run a checkpoint on database iDb. This is a no-op if database iDb is
2406 ** not currently open in WAL mode.
2407 **
2408 ** If a transaction is open on the database being checkpointed, this
2409 ** function returns SQLITE_LOCKED and a checkpoint is not attempted. If
2410 ** an error occurs while running the checkpoint, an SQLite error code is
2411 ** returned (i.e. SQLITE_IOERR). Otherwise, SQLITE_OK.
2412 **
2413 ** The mutex on database handle db should be held by the caller. The mutex
2414 ** associated with the specific b-tree being checkpointed is taken by
2415 ** this function while the checkpoint is running.
2416 **
2417 ** If iDb is passed SQLITE_MAX_ATTACHED, then all attached databases are
2418 ** checkpointed. If an error is encountered it is returned immediately -
2419 ** no attempt is made to checkpoint any remaining databases.
2420 **
2421 ** Parameter eMode is one of SQLITE_CHECKPOINT_PASSIVE, FULL, RESTART
2422 ** or TRUNCATE.
2423 */
2424 int sqlite3Checkpoint(sqlite3 *db, int iDb, int eMode, int *pnLog, int *pnCkpt){
2425   int rc = SQLITE_OK;             /* Return code */
2426   int i;                          /* Used to iterate through attached dbs */
2427   int bBusy = 0;                  /* True if SQLITE_BUSY has been encountered */
2428 
2429   assert( sqlite3_mutex_held(db->mutex) );
2430   assert( !pnLog || *pnLog==-1 );
2431   assert( !pnCkpt || *pnCkpt==-1 );
2432 
2433   for(i=0; i<db->nDb && rc==SQLITE_OK; i++){
2434     if( i==iDb || iDb==SQLITE_MAX_ATTACHED ){
2435       rc = sqlite3BtreeCheckpoint(db->aDb[i].pBt, eMode, pnLog, pnCkpt);
2436       pnLog = 0;
2437       pnCkpt = 0;
2438       if( rc==SQLITE_BUSY ){
2439         bBusy = 1;
2440         rc = SQLITE_OK;
2441       }
2442     }
2443   }
2444 
2445   return (rc==SQLITE_OK && bBusy) ? SQLITE_BUSY : rc;
2446 }
2447 #endif /* SQLITE_OMIT_WAL */
2448 
2449 /*
2450 ** This function returns true if main-memory should be used instead of
2451 ** a temporary file for transient pager files and statement journals.
2452 ** The value returned depends on the value of db->temp_store (runtime
2453 ** parameter) and the compile time value of SQLITE_TEMP_STORE. The
2454 ** following table describes the relationship between these two values
2455 ** and this functions return value.
2456 **
2457 **   SQLITE_TEMP_STORE     db->temp_store     Location of temporary database
2458 **   -----------------     --------------     ------------------------------
2459 **   0                     any                file      (return 0)
2460 **   1                     1                  file      (return 0)
2461 **   1                     2                  memory    (return 1)
2462 **   1                     0                  file      (return 0)
2463 **   2                     1                  file      (return 0)
2464 **   2                     2                  memory    (return 1)
2465 **   2                     0                  memory    (return 1)
2466 **   3                     any                memory    (return 1)
2467 */
2468 int sqlite3TempInMemory(const sqlite3 *db){
2469 #if SQLITE_TEMP_STORE==1
2470   return ( db->temp_store==2 );
2471 #endif
2472 #if SQLITE_TEMP_STORE==2
2473   return ( db->temp_store!=1 );
2474 #endif
2475 #if SQLITE_TEMP_STORE==3
2476   UNUSED_PARAMETER(db);
2477   return 1;
2478 #endif
2479 #if SQLITE_TEMP_STORE<1 || SQLITE_TEMP_STORE>3
2480   UNUSED_PARAMETER(db);
2481   return 0;
2482 #endif
2483 }
2484 
2485 /*
2486 ** Return UTF-8 encoded English language explanation of the most recent
2487 ** error.
2488 */
2489 const char *sqlite3_errmsg(sqlite3 *db){
2490   const char *z;
2491   if( !db ){
2492     return sqlite3ErrStr(SQLITE_NOMEM_BKPT);
2493   }
2494   if( !sqlite3SafetyCheckSickOrOk(db) ){
2495     return sqlite3ErrStr(SQLITE_MISUSE_BKPT);
2496   }
2497   sqlite3_mutex_enter(db->mutex);
2498   if( db->mallocFailed ){
2499     z = sqlite3ErrStr(SQLITE_NOMEM_BKPT);
2500   }else{
2501     testcase( db->pErr==0 );
2502     z = db->errCode ? (char*)sqlite3_value_text(db->pErr) : 0;
2503     assert( !db->mallocFailed );
2504     if( z==0 ){
2505       z = sqlite3ErrStr(db->errCode);
2506     }
2507   }
2508   sqlite3_mutex_leave(db->mutex);
2509   return z;
2510 }
2511 
2512 #ifndef SQLITE_OMIT_UTF16
2513 /*
2514 ** Return UTF-16 encoded English language explanation of the most recent
2515 ** error.
2516 */
2517 const void *sqlite3_errmsg16(sqlite3 *db){
2518   static const u16 outOfMem[] = {
2519     'o', 'u', 't', ' ', 'o', 'f', ' ', 'm', 'e', 'm', 'o', 'r', 'y', 0
2520   };
2521   static const u16 misuse[] = {
2522     'b', 'a', 'd', ' ', 'p', 'a', 'r', 'a', 'm', 'e', 't', 'e', 'r', ' ',
2523     'o', 'r', ' ', 'o', 't', 'h', 'e', 'r', ' ', 'A', 'P', 'I', ' ',
2524     'm', 'i', 's', 'u', 's', 'e', 0
2525   };
2526 
2527   const void *z;
2528   if( !db ){
2529     return (void *)outOfMem;
2530   }
2531   if( !sqlite3SafetyCheckSickOrOk(db) ){
2532     return (void *)misuse;
2533   }
2534   sqlite3_mutex_enter(db->mutex);
2535   if( db->mallocFailed ){
2536     z = (void *)outOfMem;
2537   }else{
2538     z = sqlite3_value_text16(db->pErr);
2539     if( z==0 ){
2540       sqlite3ErrorWithMsg(db, db->errCode, sqlite3ErrStr(db->errCode));
2541       z = sqlite3_value_text16(db->pErr);
2542     }
2543     /* A malloc() may have failed within the call to sqlite3_value_text16()
2544     ** above. If this is the case, then the db->mallocFailed flag needs to
2545     ** be cleared before returning. Do this directly, instead of via
2546     ** sqlite3ApiExit(), to avoid setting the database handle error message.
2547     */
2548     sqlite3OomClear(db);
2549   }
2550   sqlite3_mutex_leave(db->mutex);
2551   return z;
2552 }
2553 #endif /* SQLITE_OMIT_UTF16 */
2554 
2555 /*
2556 ** Return the most recent error code generated by an SQLite routine. If NULL is
2557 ** passed to this function, we assume a malloc() failed during sqlite3_open().
2558 */
2559 int sqlite3_errcode(sqlite3 *db){
2560   if( db && !sqlite3SafetyCheckSickOrOk(db) ){
2561     return SQLITE_MISUSE_BKPT;
2562   }
2563   if( !db || db->mallocFailed ){
2564     return SQLITE_NOMEM_BKPT;
2565   }
2566   return db->errCode & db->errMask;
2567 }
2568 int sqlite3_extended_errcode(sqlite3 *db){
2569   if( db && !sqlite3SafetyCheckSickOrOk(db) ){
2570     return SQLITE_MISUSE_BKPT;
2571   }
2572   if( !db || db->mallocFailed ){
2573     return SQLITE_NOMEM_BKPT;
2574   }
2575   return db->errCode;
2576 }
2577 int sqlite3_system_errno(sqlite3 *db){
2578   return db ? db->iSysErrno : 0;
2579 }
2580 
2581 /*
2582 ** Return a string that describes the kind of error specified in the
2583 ** argument.  For now, this simply calls the internal sqlite3ErrStr()
2584 ** function.
2585 */
2586 const char *sqlite3_errstr(int rc){
2587   return sqlite3ErrStr(rc);
2588 }
2589 
2590 /*
2591 ** Create a new collating function for database "db".  The name is zName
2592 ** and the encoding is enc.
2593 */
2594 static int createCollation(
2595   sqlite3* db,
2596   const char *zName,
2597   u8 enc,
2598   void* pCtx,
2599   int(*xCompare)(void*,int,const void*,int,const void*),
2600   void(*xDel)(void*)
2601 ){
2602   CollSeq *pColl;
2603   int enc2;
2604 
2605   assert( sqlite3_mutex_held(db->mutex) );
2606 
2607   /* If SQLITE_UTF16 is specified as the encoding type, transform this
2608   ** to one of SQLITE_UTF16LE or SQLITE_UTF16BE using the
2609   ** SQLITE_UTF16NATIVE macro. SQLITE_UTF16 is not used internally.
2610   */
2611   enc2 = enc;
2612   testcase( enc2==SQLITE_UTF16 );
2613   testcase( enc2==SQLITE_UTF16_ALIGNED );
2614   if( enc2==SQLITE_UTF16 || enc2==SQLITE_UTF16_ALIGNED ){
2615     enc2 = SQLITE_UTF16NATIVE;
2616   }
2617   if( enc2<SQLITE_UTF8 || enc2>SQLITE_UTF16BE ){
2618     return SQLITE_MISUSE_BKPT;
2619   }
2620 
2621   /* Check if this call is removing or replacing an existing collation
2622   ** sequence. If so, and there are active VMs, return busy. If there
2623   ** are no active VMs, invalidate any pre-compiled statements.
2624   */
2625   pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, 0);
2626   if( pColl && pColl->xCmp ){
2627     if( db->nVdbeActive ){
2628       sqlite3ErrorWithMsg(db, SQLITE_BUSY,
2629         "unable to delete/modify collation sequence due to active statements");
2630       return SQLITE_BUSY;
2631     }
2632     sqlite3ExpirePreparedStatements(db, 0);
2633 
2634     /* If collation sequence pColl was created directly by a call to
2635     ** sqlite3_create_collation, and not generated by synthCollSeq(),
2636     ** then any copies made by synthCollSeq() need to be invalidated.
2637     ** Also, collation destructor - CollSeq.xDel() - function may need
2638     ** to be called.
2639     */
2640     if( (pColl->enc & ~SQLITE_UTF16_ALIGNED)==enc2 ){
2641       CollSeq *aColl = sqlite3HashFind(&db->aCollSeq, zName);
2642       int j;
2643       for(j=0; j<3; j++){
2644         CollSeq *p = &aColl[j];
2645         if( p->enc==pColl->enc ){
2646           if( p->xDel ){
2647             p->xDel(p->pUser);
2648           }
2649           p->xCmp = 0;
2650         }
2651       }
2652     }
2653   }
2654 
2655   pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, 1);
2656   if( pColl==0 ) return SQLITE_NOMEM_BKPT;
2657   pColl->xCmp = xCompare;
2658   pColl->pUser = pCtx;
2659   pColl->xDel = xDel;
2660   pColl->enc = (u8)(enc2 | (enc & SQLITE_UTF16_ALIGNED));
2661   sqlite3Error(db, SQLITE_OK);
2662   return SQLITE_OK;
2663 }
2664 
2665 
2666 /*
2667 ** This array defines hard upper bounds on limit values.  The
2668 ** initializer must be kept in sync with the SQLITE_LIMIT_*
2669 ** #defines in sqlite3.h.
2670 */
2671 static const int aHardLimit[] = {
2672   SQLITE_MAX_LENGTH,
2673   SQLITE_MAX_SQL_LENGTH,
2674   SQLITE_MAX_COLUMN,
2675   SQLITE_MAX_EXPR_DEPTH,
2676   SQLITE_MAX_COMPOUND_SELECT,
2677   SQLITE_MAX_VDBE_OP,
2678   SQLITE_MAX_FUNCTION_ARG,
2679   SQLITE_MAX_ATTACHED,
2680   SQLITE_MAX_LIKE_PATTERN_LENGTH,
2681   SQLITE_MAX_VARIABLE_NUMBER,      /* IMP: R-38091-32352 */
2682   SQLITE_MAX_TRIGGER_DEPTH,
2683   SQLITE_MAX_WORKER_THREADS,
2684 };
2685 
2686 /*
2687 ** Make sure the hard limits are set to reasonable values
2688 */
2689 #if SQLITE_MAX_LENGTH<100
2690 # error SQLITE_MAX_LENGTH must be at least 100
2691 #endif
2692 #if SQLITE_MAX_SQL_LENGTH<100
2693 # error SQLITE_MAX_SQL_LENGTH must be at least 100
2694 #endif
2695 #if SQLITE_MAX_SQL_LENGTH>SQLITE_MAX_LENGTH
2696 # error SQLITE_MAX_SQL_LENGTH must not be greater than SQLITE_MAX_LENGTH
2697 #endif
2698 #if SQLITE_MAX_COMPOUND_SELECT<2
2699 # error SQLITE_MAX_COMPOUND_SELECT must be at least 2
2700 #endif
2701 #if SQLITE_MAX_VDBE_OP<40
2702 # error SQLITE_MAX_VDBE_OP must be at least 40
2703 #endif
2704 #if SQLITE_MAX_FUNCTION_ARG<0 || SQLITE_MAX_FUNCTION_ARG>127
2705 # error SQLITE_MAX_FUNCTION_ARG must be between 0 and 127
2706 #endif
2707 #if SQLITE_MAX_ATTACHED<0 || SQLITE_MAX_ATTACHED>125
2708 # error SQLITE_MAX_ATTACHED must be between 0 and 125
2709 #endif
2710 #if SQLITE_MAX_LIKE_PATTERN_LENGTH<1
2711 # error SQLITE_MAX_LIKE_PATTERN_LENGTH must be at least 1
2712 #endif
2713 #if SQLITE_MAX_COLUMN>32767
2714 # error SQLITE_MAX_COLUMN must not exceed 32767
2715 #endif
2716 #if SQLITE_MAX_TRIGGER_DEPTH<1
2717 # error SQLITE_MAX_TRIGGER_DEPTH must be at least 1
2718 #endif
2719 #if SQLITE_MAX_WORKER_THREADS<0 || SQLITE_MAX_WORKER_THREADS>50
2720 # error SQLITE_MAX_WORKER_THREADS must be between 0 and 50
2721 #endif
2722 
2723 
2724 /*
2725 ** Change the value of a limit.  Report the old value.
2726 ** If an invalid limit index is supplied, report -1.
2727 ** Make no changes but still report the old value if the
2728 ** new limit is negative.
2729 **
2730 ** A new lower limit does not shrink existing constructs.
2731 ** It merely prevents new constructs that exceed the limit
2732 ** from forming.
2733 */
2734 int sqlite3_limit(sqlite3 *db, int limitId, int newLimit){
2735   int oldLimit;
2736 
2737 #ifdef SQLITE_ENABLE_API_ARMOR
2738   if( !sqlite3SafetyCheckOk(db) ){
2739     (void)SQLITE_MISUSE_BKPT;
2740     return -1;
2741   }
2742 #endif
2743 
2744   /* EVIDENCE-OF: R-30189-54097 For each limit category SQLITE_LIMIT_NAME
2745   ** there is a hard upper bound set at compile-time by a C preprocessor
2746   ** macro called SQLITE_MAX_NAME. (The "_LIMIT_" in the name is changed to
2747   ** "_MAX_".)
2748   */
2749   assert( aHardLimit[SQLITE_LIMIT_LENGTH]==SQLITE_MAX_LENGTH );
2750   assert( aHardLimit[SQLITE_LIMIT_SQL_LENGTH]==SQLITE_MAX_SQL_LENGTH );
2751   assert( aHardLimit[SQLITE_LIMIT_COLUMN]==SQLITE_MAX_COLUMN );
2752   assert( aHardLimit[SQLITE_LIMIT_EXPR_DEPTH]==SQLITE_MAX_EXPR_DEPTH );
2753   assert( aHardLimit[SQLITE_LIMIT_COMPOUND_SELECT]==SQLITE_MAX_COMPOUND_SELECT);
2754   assert( aHardLimit[SQLITE_LIMIT_VDBE_OP]==SQLITE_MAX_VDBE_OP );
2755   assert( aHardLimit[SQLITE_LIMIT_FUNCTION_ARG]==SQLITE_MAX_FUNCTION_ARG );
2756   assert( aHardLimit[SQLITE_LIMIT_ATTACHED]==SQLITE_MAX_ATTACHED );
2757   assert( aHardLimit[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]==
2758                                                SQLITE_MAX_LIKE_PATTERN_LENGTH );
2759   assert( aHardLimit[SQLITE_LIMIT_VARIABLE_NUMBER]==SQLITE_MAX_VARIABLE_NUMBER);
2760   assert( aHardLimit[SQLITE_LIMIT_TRIGGER_DEPTH]==SQLITE_MAX_TRIGGER_DEPTH );
2761   assert( aHardLimit[SQLITE_LIMIT_WORKER_THREADS]==SQLITE_MAX_WORKER_THREADS );
2762   assert( SQLITE_LIMIT_WORKER_THREADS==(SQLITE_N_LIMIT-1) );
2763 
2764 
2765   if( limitId<0 || limitId>=SQLITE_N_LIMIT ){
2766     return -1;
2767   }
2768   oldLimit = db->aLimit[limitId];
2769   if( newLimit>=0 ){                   /* IMP: R-52476-28732 */
2770     if( newLimit>aHardLimit[limitId] ){
2771       newLimit = aHardLimit[limitId];  /* IMP: R-51463-25634 */
2772     }
2773     db->aLimit[limitId] = newLimit;
2774   }
2775   return oldLimit;                     /* IMP: R-53341-35419 */
2776 }
2777 
2778 /*
2779 ** This function is used to parse both URIs and non-URI filenames passed by the
2780 ** user to API functions sqlite3_open() or sqlite3_open_v2(), and for database
2781 ** URIs specified as part of ATTACH statements.
2782 **
2783 ** The first argument to this function is the name of the VFS to use (or
2784 ** a NULL to signify the default VFS) if the URI does not contain a "vfs=xxx"
2785 ** query parameter. The second argument contains the URI (or non-URI filename)
2786 ** itself. When this function is called the *pFlags variable should contain
2787 ** the default flags to open the database handle with. The value stored in
2788 ** *pFlags may be updated before returning if the URI filename contains
2789 ** "cache=xxx" or "mode=xxx" query parameters.
2790 **
2791 ** If successful, SQLITE_OK is returned. In this case *ppVfs is set to point to
2792 ** the VFS that should be used to open the database file. *pzFile is set to
2793 ** point to a buffer containing the name of the file to open.  The value
2794 ** stored in *pzFile is a database name acceptable to sqlite3_uri_parameter()
2795 ** and is in the same format as names created using sqlite3_create_filename().
2796 ** The caller must invoke sqlite3_free_filename() (not sqlite3_free()!) on
2797 ** the value returned in *pzFile to avoid a memory leak.
2798 **
2799 ** If an error occurs, then an SQLite error code is returned and *pzErrMsg
2800 ** may be set to point to a buffer containing an English language error
2801 ** message. It is the responsibility of the caller to eventually release
2802 ** this buffer by calling sqlite3_free().
2803 */
2804 int sqlite3ParseUri(
2805   const char *zDefaultVfs,        /* VFS to use if no "vfs=xxx" query option */
2806   const char *zUri,               /* Nul-terminated URI to parse */
2807   unsigned int *pFlags,           /* IN/OUT: SQLITE_OPEN_XXX flags */
2808   sqlite3_vfs **ppVfs,            /* OUT: VFS to use */
2809   char **pzFile,                  /* OUT: Filename component of URI */
2810   char **pzErrMsg                 /* OUT: Error message (if rc!=SQLITE_OK) */
2811 ){
2812   int rc = SQLITE_OK;
2813   unsigned int flags = *pFlags;
2814   const char *zVfs = zDefaultVfs;
2815   char *zFile;
2816   char c;
2817   int nUri = sqlite3Strlen30(zUri);
2818 
2819   assert( *pzErrMsg==0 );
2820 
2821   if( ((flags & SQLITE_OPEN_URI)             /* IMP: R-48725-32206 */
2822             || sqlite3GlobalConfig.bOpenUri) /* IMP: R-51689-46548 */
2823    && nUri>=5 && memcmp(zUri, "file:", 5)==0 /* IMP: R-57884-37496 */
2824   ){
2825     char *zOpt;
2826     int eState;                   /* Parser state when parsing URI */
2827     int iIn;                      /* Input character index */
2828     int iOut = 0;                 /* Output character index */
2829     u64 nByte = nUri+8;           /* Bytes of space to allocate */
2830 
2831     /* Make sure the SQLITE_OPEN_URI flag is set to indicate to the VFS xOpen
2832     ** method that there may be extra parameters following the file-name.  */
2833     flags |= SQLITE_OPEN_URI;
2834 
2835     for(iIn=0; iIn<nUri; iIn++) nByte += (zUri[iIn]=='&');
2836     zFile = sqlite3_malloc64(nByte);
2837     if( !zFile ) return SQLITE_NOMEM_BKPT;
2838 
2839     memset(zFile, 0, 4);  /* 4-byte of 0x00 is the start of DB name marker */
2840     zFile += 4;
2841 
2842     iIn = 5;
2843 #ifdef SQLITE_ALLOW_URI_AUTHORITY
2844     if( strncmp(zUri+5, "///", 3)==0 ){
2845       iIn = 7;
2846       /* The following condition causes URIs with five leading / characters
2847       ** like file://///host/path to be converted into UNCs like //host/path.
2848       ** The correct URI for that UNC has only two or four leading / characters
2849       ** file://host/path or file:////host/path.  But 5 leading slashes is a
2850       ** common error, we are told, so we handle it as a special case. */
2851       if( strncmp(zUri+7, "///", 3)==0 ){ iIn++; }
2852     }else if( strncmp(zUri+5, "//localhost/", 12)==0 ){
2853       iIn = 16;
2854     }
2855 #else
2856     /* Discard the scheme and authority segments of the URI. */
2857     if( zUri[5]=='/' && zUri[6]=='/' ){
2858       iIn = 7;
2859       while( zUri[iIn] && zUri[iIn]!='/' ) iIn++;
2860       if( iIn!=7 && (iIn!=16 || memcmp("localhost", &zUri[7], 9)) ){
2861         *pzErrMsg = sqlite3_mprintf("invalid uri authority: %.*s",
2862             iIn-7, &zUri[7]);
2863         rc = SQLITE_ERROR;
2864         goto parse_uri_out;
2865       }
2866     }
2867 #endif
2868 
2869     /* Copy the filename and any query parameters into the zFile buffer.
2870     ** Decode %HH escape codes along the way.
2871     **
2872     ** Within this loop, variable eState may be set to 0, 1 or 2, depending
2873     ** on the parsing context. As follows:
2874     **
2875     **   0: Parsing file-name.
2876     **   1: Parsing name section of a name=value query parameter.
2877     **   2: Parsing value section of a name=value query parameter.
2878     */
2879     eState = 0;
2880     while( (c = zUri[iIn])!=0 && c!='#' ){
2881       iIn++;
2882       if( c=='%'
2883        && sqlite3Isxdigit(zUri[iIn])
2884        && sqlite3Isxdigit(zUri[iIn+1])
2885       ){
2886         int octet = (sqlite3HexToInt(zUri[iIn++]) << 4);
2887         octet += sqlite3HexToInt(zUri[iIn++]);
2888 
2889         assert( octet>=0 && octet<256 );
2890         if( octet==0 ){
2891 #ifndef SQLITE_ENABLE_URI_00_ERROR
2892           /* This branch is taken when "%00" appears within the URI. In this
2893           ** case we ignore all text in the remainder of the path, name or
2894           ** value currently being parsed. So ignore the current character
2895           ** and skip to the next "?", "=" or "&", as appropriate. */
2896           while( (c = zUri[iIn])!=0 && c!='#'
2897               && (eState!=0 || c!='?')
2898               && (eState!=1 || (c!='=' && c!='&'))
2899               && (eState!=2 || c!='&')
2900           ){
2901             iIn++;
2902           }
2903           continue;
2904 #else
2905           /* If ENABLE_URI_00_ERROR is defined, "%00" in a URI is an error. */
2906           *pzErrMsg = sqlite3_mprintf("unexpected %%00 in uri");
2907           rc = SQLITE_ERROR;
2908           goto parse_uri_out;
2909 #endif
2910         }
2911         c = octet;
2912       }else if( eState==1 && (c=='&' || c=='=') ){
2913         if( zFile[iOut-1]==0 ){
2914           /* An empty option name. Ignore this option altogether. */
2915           while( zUri[iIn] && zUri[iIn]!='#' && zUri[iIn-1]!='&' ) iIn++;
2916           continue;
2917         }
2918         if( c=='&' ){
2919           zFile[iOut++] = '\0';
2920         }else{
2921           eState = 2;
2922         }
2923         c = 0;
2924       }else if( (eState==0 && c=='?') || (eState==2 && c=='&') ){
2925         c = 0;
2926         eState = 1;
2927       }
2928       zFile[iOut++] = c;
2929     }
2930     if( eState==1 ) zFile[iOut++] = '\0';
2931     memset(zFile+iOut, 0, 4); /* end-of-options + empty journal filenames */
2932 
2933     /* Check if there were any options specified that should be interpreted
2934     ** here. Options that are interpreted here include "vfs" and those that
2935     ** correspond to flags that may be passed to the sqlite3_open_v2()
2936     ** method. */
2937     zOpt = &zFile[sqlite3Strlen30(zFile)+1];
2938     while( zOpt[0] ){
2939       int nOpt = sqlite3Strlen30(zOpt);
2940       char *zVal = &zOpt[nOpt+1];
2941       int nVal = sqlite3Strlen30(zVal);
2942 
2943       if( nOpt==3 && memcmp("vfs", zOpt, 3)==0 ){
2944         zVfs = zVal;
2945       }else{
2946         struct OpenMode {
2947           const char *z;
2948           int mode;
2949         } *aMode = 0;
2950         char *zModeType = 0;
2951         int mask = 0;
2952         int limit = 0;
2953 
2954         if( nOpt==5 && memcmp("cache", zOpt, 5)==0 ){
2955           static struct OpenMode aCacheMode[] = {
2956             { "shared",  SQLITE_OPEN_SHAREDCACHE },
2957             { "private", SQLITE_OPEN_PRIVATECACHE },
2958             { 0, 0 }
2959           };
2960 
2961           mask = SQLITE_OPEN_SHAREDCACHE|SQLITE_OPEN_PRIVATECACHE;
2962           aMode = aCacheMode;
2963           limit = mask;
2964           zModeType = "cache";
2965         }
2966         if( nOpt==4 && memcmp("mode", zOpt, 4)==0 ){
2967           static struct OpenMode aOpenMode[] = {
2968             { "ro",  SQLITE_OPEN_READONLY },
2969             { "rw",  SQLITE_OPEN_READWRITE },
2970             { "rwc", SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE },
2971             { "memory", SQLITE_OPEN_MEMORY },
2972             { 0, 0 }
2973           };
2974 
2975           mask = SQLITE_OPEN_READONLY | SQLITE_OPEN_READWRITE
2976                    | SQLITE_OPEN_CREATE | SQLITE_OPEN_MEMORY;
2977           aMode = aOpenMode;
2978           limit = mask & flags;
2979           zModeType = "access";
2980         }
2981 
2982         if( aMode ){
2983           int i;
2984           int mode = 0;
2985           for(i=0; aMode[i].z; i++){
2986             const char *z = aMode[i].z;
2987             if( nVal==sqlite3Strlen30(z) && 0==memcmp(zVal, z, nVal) ){
2988               mode = aMode[i].mode;
2989               break;
2990             }
2991           }
2992           if( mode==0 ){
2993             *pzErrMsg = sqlite3_mprintf("no such %s mode: %s", zModeType, zVal);
2994             rc = SQLITE_ERROR;
2995             goto parse_uri_out;
2996           }
2997           if( (mode & ~SQLITE_OPEN_MEMORY)>limit ){
2998             *pzErrMsg = sqlite3_mprintf("%s mode not allowed: %s",
2999                                         zModeType, zVal);
3000             rc = SQLITE_PERM;
3001             goto parse_uri_out;
3002           }
3003           flags = (flags & ~mask) | mode;
3004         }
3005       }
3006 
3007       zOpt = &zVal[nVal+1];
3008     }
3009 
3010   }else{
3011     zFile = sqlite3_malloc64(nUri+8);
3012     if( !zFile ) return SQLITE_NOMEM_BKPT;
3013     memset(zFile, 0, 4);
3014     zFile += 4;
3015     if( nUri ){
3016       memcpy(zFile, zUri, nUri);
3017     }
3018     memset(zFile+nUri, 0, 4);
3019     flags &= ~SQLITE_OPEN_URI;
3020   }
3021 
3022   *ppVfs = sqlite3_vfs_find(zVfs);
3023   if( *ppVfs==0 ){
3024     *pzErrMsg = sqlite3_mprintf("no such vfs: %s", zVfs);
3025     rc = SQLITE_ERROR;
3026   }
3027  parse_uri_out:
3028   if( rc!=SQLITE_OK ){
3029     sqlite3_free_filename(zFile);
3030     zFile = 0;
3031   }
3032   *pFlags = flags;
3033   *pzFile = zFile;
3034   return rc;
3035 }
3036 
3037 /*
3038 ** This routine does the core work of extracting URI parameters from a
3039 ** database filename for the sqlite3_uri_parameter() interface.
3040 */
3041 static const char *uriParameter(const char *zFilename, const char *zParam){
3042   zFilename += sqlite3Strlen30(zFilename) + 1;
3043   while( zFilename[0] ){
3044     int x = strcmp(zFilename, zParam);
3045     zFilename += sqlite3Strlen30(zFilename) + 1;
3046     if( x==0 ) return zFilename;
3047     zFilename += sqlite3Strlen30(zFilename) + 1;
3048   }
3049   return 0;
3050 }
3051 
3052 
3053 
3054 /*
3055 ** This routine does the work of opening a database on behalf of
3056 ** sqlite3_open() and sqlite3_open16(). The database filename "zFilename"
3057 ** is UTF-8 encoded.
3058 */
3059 static int openDatabase(
3060   const char *zFilename, /* Database filename UTF-8 encoded */
3061   sqlite3 **ppDb,        /* OUT: Returned database handle */
3062   unsigned int flags,    /* Operational flags */
3063   const char *zVfs       /* Name of the VFS to use */
3064 ){
3065   sqlite3 *db;                    /* Store allocated handle here */
3066   int rc;                         /* Return code */
3067   int isThreadsafe;               /* True for threadsafe connections */
3068   char *zOpen = 0;                /* Filename argument to pass to BtreeOpen() */
3069   char *zErrMsg = 0;              /* Error message from sqlite3ParseUri() */
3070   int i;                          /* Loop counter */
3071 
3072 #ifdef SQLITE_ENABLE_API_ARMOR
3073   if( ppDb==0 ) return SQLITE_MISUSE_BKPT;
3074 #endif
3075   *ppDb = 0;
3076 #ifndef SQLITE_OMIT_AUTOINIT
3077   rc = sqlite3_initialize();
3078   if( rc ) return rc;
3079 #endif
3080 
3081   if( sqlite3GlobalConfig.bCoreMutex==0 ){
3082     isThreadsafe = 0;
3083   }else if( flags & SQLITE_OPEN_NOMUTEX ){
3084     isThreadsafe = 0;
3085   }else if( flags & SQLITE_OPEN_FULLMUTEX ){
3086     isThreadsafe = 1;
3087   }else{
3088     isThreadsafe = sqlite3GlobalConfig.bFullMutex;
3089   }
3090 
3091   if( flags & SQLITE_OPEN_PRIVATECACHE ){
3092     flags &= ~SQLITE_OPEN_SHAREDCACHE;
3093   }else if( sqlite3GlobalConfig.sharedCacheEnabled ){
3094     flags |= SQLITE_OPEN_SHAREDCACHE;
3095   }
3096 
3097   /* Remove harmful bits from the flags parameter
3098   **
3099   ** The SQLITE_OPEN_NOMUTEX and SQLITE_OPEN_FULLMUTEX flags were
3100   ** dealt with in the previous code block.  Besides these, the only
3101   ** valid input flags for sqlite3_open_v2() are SQLITE_OPEN_READONLY,
3102   ** SQLITE_OPEN_READWRITE, SQLITE_OPEN_CREATE, SQLITE_OPEN_SHAREDCACHE,
3103   ** SQLITE_OPEN_PRIVATECACHE, and some reserved bits.  Silently mask
3104   ** off all other flags.
3105   */
3106   flags &=  ~( SQLITE_OPEN_DELETEONCLOSE |
3107                SQLITE_OPEN_EXCLUSIVE |
3108                SQLITE_OPEN_MAIN_DB |
3109                SQLITE_OPEN_TEMP_DB |
3110                SQLITE_OPEN_TRANSIENT_DB |
3111                SQLITE_OPEN_MAIN_JOURNAL |
3112                SQLITE_OPEN_TEMP_JOURNAL |
3113                SQLITE_OPEN_SUBJOURNAL |
3114                SQLITE_OPEN_MASTER_JOURNAL |
3115                SQLITE_OPEN_NOMUTEX |
3116                SQLITE_OPEN_FULLMUTEX |
3117                SQLITE_OPEN_WAL
3118              );
3119 
3120   /* Allocate the sqlite data structure */
3121   db = sqlite3MallocZero( sizeof(sqlite3) );
3122   if( db==0 ) goto opendb_out;
3123   if( isThreadsafe
3124 #ifdef SQLITE_ENABLE_MULTITHREADED_CHECKS
3125    || sqlite3GlobalConfig.bCoreMutex
3126 #endif
3127   ){
3128     db->mutex = sqlite3MutexAlloc(SQLITE_MUTEX_RECURSIVE);
3129     if( db->mutex==0 ){
3130       sqlite3_free(db);
3131       db = 0;
3132       goto opendb_out;
3133     }
3134     if( isThreadsafe==0 ){
3135       sqlite3MutexWarnOnContention(db->mutex);
3136     }
3137   }
3138   sqlite3_mutex_enter(db->mutex);
3139   db->errMask = 0xff;
3140   db->nDb = 2;
3141   db->magic = SQLITE_MAGIC_BUSY;
3142   db->aDb = db->aDbStatic;
3143   db->lookaside.bDisable = 1;
3144   db->lookaside.sz = 0;
3145 
3146   assert( sizeof(db->aLimit)==sizeof(aHardLimit) );
3147   memcpy(db->aLimit, aHardLimit, sizeof(db->aLimit));
3148   db->aLimit[SQLITE_LIMIT_WORKER_THREADS] = SQLITE_DEFAULT_WORKER_THREADS;
3149   db->autoCommit = 1;
3150   db->nextAutovac = -1;
3151   db->szMmap = sqlite3GlobalConfig.szMmap;
3152   db->nextPagesize = 0;
3153   db->nMaxSorterMmap = 0x7FFFFFFF;
3154   db->flags |= SQLITE_ShortColNames
3155                  | SQLITE_EnableTrigger
3156                  | SQLITE_EnableView
3157                  | SQLITE_CacheSpill
3158 #if !defined(SQLITE_TRUSTED_SCHEMA) || SQLITE_TRUSTED_SCHEMA+0!=0
3159                  | SQLITE_TrustedSchema
3160 #endif
3161 /* The SQLITE_DQS compile-time option determines the default settings
3162 ** for SQLITE_DBCONFIG_DQS_DDL and SQLITE_DBCONFIG_DQS_DML.
3163 **
3164 **    SQLITE_DQS     SQLITE_DBCONFIG_DQS_DDL    SQLITE_DBCONFIG_DQS_DML
3165 **    ----------     -----------------------    -----------------------
3166 **     undefined               on                          on
3167 **         3                   on                          on
3168 **         2                   on                         off
3169 **         1                  off                          on
3170 **         0                  off                         off
3171 **
3172 ** Legacy behavior is 3 (double-quoted string literals are allowed anywhere)
3173 ** and so that is the default.  But developers are encouranged to use
3174 ** -DSQLITE_DQS=0 (best) or -DSQLITE_DQS=1 (second choice) if possible.
3175 */
3176 #if !defined(SQLITE_DQS)
3177 # define SQLITE_DQS 3
3178 #endif
3179 #if (SQLITE_DQS&1)==1
3180                  | SQLITE_DqsDML
3181 #endif
3182 #if (SQLITE_DQS&2)==2
3183                  | SQLITE_DqsDDL
3184 #endif
3185 
3186 #if !defined(SQLITE_DEFAULT_AUTOMATIC_INDEX) || SQLITE_DEFAULT_AUTOMATIC_INDEX
3187                  | SQLITE_AutoIndex
3188 #endif
3189 #if SQLITE_DEFAULT_CKPTFULLFSYNC
3190                  | SQLITE_CkptFullFSync
3191 #endif
3192 #if SQLITE_DEFAULT_FILE_FORMAT<4
3193                  | SQLITE_LegacyFileFmt
3194 #endif
3195 #ifdef SQLITE_ENABLE_LOAD_EXTENSION
3196                  | SQLITE_LoadExtension
3197 #endif
3198 #if SQLITE_DEFAULT_RECURSIVE_TRIGGERS
3199                  | SQLITE_RecTriggers
3200 #endif
3201 #if defined(SQLITE_DEFAULT_FOREIGN_KEYS) && SQLITE_DEFAULT_FOREIGN_KEYS
3202                  | SQLITE_ForeignKeys
3203 #endif
3204 #if defined(SQLITE_REVERSE_UNORDERED_SELECTS)
3205                  | SQLITE_ReverseOrder
3206 #endif
3207 #if defined(SQLITE_ENABLE_OVERSIZE_CELL_CHECK)
3208                  | SQLITE_CellSizeCk
3209 #endif
3210 #if defined(SQLITE_ENABLE_FTS3_TOKENIZER)
3211                  | SQLITE_Fts3Tokenizer
3212 #endif
3213 #if defined(SQLITE_ENABLE_QPSG)
3214                  | SQLITE_EnableQPSG
3215 #endif
3216 #if defined(SQLITE_DEFAULT_DEFENSIVE)
3217                  | SQLITE_Defensive
3218 #endif
3219 #if defined(SQLITE_DEFAULT_LEGACY_ALTER_TABLE)
3220                  | SQLITE_LegacyAlter
3221 #endif
3222       ;
3223   sqlite3HashInit(&db->aCollSeq);
3224 #ifndef SQLITE_OMIT_VIRTUALTABLE
3225   sqlite3HashInit(&db->aModule);
3226 #endif
3227 
3228   /* Add the default collation sequence BINARY. BINARY works for both UTF-8
3229   ** and UTF-16, so add a version for each to avoid any unnecessary
3230   ** conversions. The only error that can occur here is a malloc() failure.
3231   **
3232   ** EVIDENCE-OF: R-52786-44878 SQLite defines three built-in collating
3233   ** functions:
3234   */
3235   createCollation(db, sqlite3StrBINARY, SQLITE_UTF8, 0, binCollFunc, 0);
3236   createCollation(db, sqlite3StrBINARY, SQLITE_UTF16BE, 0, binCollFunc, 0);
3237   createCollation(db, sqlite3StrBINARY, SQLITE_UTF16LE, 0, binCollFunc, 0);
3238   createCollation(db, "NOCASE", SQLITE_UTF8, 0, nocaseCollatingFunc, 0);
3239   createCollation(db, "RTRIM", SQLITE_UTF8, 0, rtrimCollFunc, 0);
3240   if( db->mallocFailed ){
3241     goto opendb_out;
3242   }
3243 
3244   /* Parse the filename/URI argument
3245   **
3246   ** Only allow sensible combinations of bits in the flags argument.
3247   ** Throw an error if any non-sense combination is used.  If we
3248   ** do not block illegal combinations here, it could trigger
3249   ** assert() statements in deeper layers.  Sensible combinations
3250   ** are:
3251   **
3252   **  1:  SQLITE_OPEN_READONLY
3253   **  2:  SQLITE_OPEN_READWRITE
3254   **  6:  SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE
3255   */
3256   db->openFlags = flags;
3257   assert( SQLITE_OPEN_READONLY  == 0x01 );
3258   assert( SQLITE_OPEN_READWRITE == 0x02 );
3259   assert( SQLITE_OPEN_CREATE    == 0x04 );
3260   testcase( (1<<(flags&7))==0x02 ); /* READONLY */
3261   testcase( (1<<(flags&7))==0x04 ); /* READWRITE */
3262   testcase( (1<<(flags&7))==0x40 ); /* READWRITE | CREATE */
3263   if( ((1<<(flags&7)) & 0x46)==0 ){
3264     rc = SQLITE_MISUSE_BKPT;  /* IMP: R-65497-44594 */
3265   }else{
3266     rc = sqlite3ParseUri(zVfs, zFilename, &flags, &db->pVfs, &zOpen, &zErrMsg);
3267   }
3268   if( rc!=SQLITE_OK ){
3269     if( rc==SQLITE_NOMEM ) sqlite3OomFault(db);
3270     sqlite3ErrorWithMsg(db, rc, zErrMsg ? "%s" : 0, zErrMsg);
3271     sqlite3_free(zErrMsg);
3272     goto opendb_out;
3273   }
3274 
3275   /* Open the backend database driver */
3276   rc = sqlite3BtreeOpen(db->pVfs, zOpen, db, &db->aDb[0].pBt, 0,
3277                         flags | SQLITE_OPEN_MAIN_DB);
3278   if( rc!=SQLITE_OK ){
3279     if( rc==SQLITE_IOERR_NOMEM ){
3280       rc = SQLITE_NOMEM_BKPT;
3281     }
3282     sqlite3Error(db, rc);
3283     goto opendb_out;
3284   }
3285   sqlite3BtreeEnter(db->aDb[0].pBt);
3286   db->aDb[0].pSchema = sqlite3SchemaGet(db, db->aDb[0].pBt);
3287   if( !db->mallocFailed ){
3288     sqlite3SetTextEncoding(db, SCHEMA_ENC(db));
3289   }
3290   sqlite3BtreeLeave(db->aDb[0].pBt);
3291   db->aDb[1].pSchema = sqlite3SchemaGet(db, 0);
3292 
3293   /* The default safety_level for the main database is FULL; for the temp
3294   ** database it is OFF. This matches the pager layer defaults.
3295   */
3296   db->aDb[0].zDbSName = "main";
3297   db->aDb[0].safety_level = SQLITE_DEFAULT_SYNCHRONOUS+1;
3298   db->aDb[1].zDbSName = "temp";
3299   db->aDb[1].safety_level = PAGER_SYNCHRONOUS_OFF;
3300 
3301   db->magic = SQLITE_MAGIC_OPEN;
3302   if( db->mallocFailed ){
3303     goto opendb_out;
3304   }
3305 
3306   /* Register all built-in functions, but do not attempt to read the
3307   ** database schema yet. This is delayed until the first time the database
3308   ** is accessed.
3309   */
3310   sqlite3Error(db, SQLITE_OK);
3311   sqlite3RegisterPerConnectionBuiltinFunctions(db);
3312   rc = sqlite3_errcode(db);
3313 
3314 
3315   /* Load compiled-in extensions */
3316   for(i=0; rc==SQLITE_OK && i<ArraySize(sqlite3BuiltinExtensions); i++){
3317     rc = sqlite3BuiltinExtensions[i](db);
3318   }
3319 
3320   /* Load automatic extensions - extensions that have been registered
3321   ** using the sqlite3_automatic_extension() API.
3322   */
3323   if( rc==SQLITE_OK ){
3324     sqlite3AutoLoadExtensions(db);
3325     rc = sqlite3_errcode(db);
3326     if( rc!=SQLITE_OK ){
3327       goto opendb_out;
3328     }
3329   }
3330 
3331 #ifdef SQLITE_ENABLE_INTERNAL_FUNCTIONS
3332   /* Testing use only!!! The -DSQLITE_ENABLE_INTERNAL_FUNCTIONS=1 compile-time
3333   ** option gives access to internal functions by default.
3334   ** Testing use only!!! */
3335   db->mDbFlags |= DBFLAG_InternalFunc;
3336 #endif
3337 
3338   /* -DSQLITE_DEFAULT_LOCKING_MODE=1 makes EXCLUSIVE the default locking
3339   ** mode.  -DSQLITE_DEFAULT_LOCKING_MODE=0 make NORMAL the default locking
3340   ** mode.  Doing nothing at all also makes NORMAL the default.
3341   */
3342 #ifdef SQLITE_DEFAULT_LOCKING_MODE
3343   db->dfltLockMode = SQLITE_DEFAULT_LOCKING_MODE;
3344   sqlite3PagerLockingMode(sqlite3BtreePager(db->aDb[0].pBt),
3345                           SQLITE_DEFAULT_LOCKING_MODE);
3346 #endif
3347 
3348   if( rc ) sqlite3Error(db, rc);
3349 
3350   /* Enable the lookaside-malloc subsystem */
3351   setupLookaside(db, 0, sqlite3GlobalConfig.szLookaside,
3352                         sqlite3GlobalConfig.nLookaside);
3353 
3354   sqlite3_wal_autocheckpoint(db, SQLITE_DEFAULT_WAL_AUTOCHECKPOINT);
3355 
3356 opendb_out:
3357   if( db ){
3358     assert( db->mutex!=0 || isThreadsafe==0
3359            || sqlite3GlobalConfig.bFullMutex==0 );
3360     sqlite3_mutex_leave(db->mutex);
3361   }
3362   rc = sqlite3_errcode(db);
3363   assert( db!=0 || rc==SQLITE_NOMEM );
3364   if( rc==SQLITE_NOMEM ){
3365     sqlite3_close(db);
3366     db = 0;
3367   }else if( rc!=SQLITE_OK ){
3368     db->magic = SQLITE_MAGIC_SICK;
3369   }
3370   *ppDb = db;
3371 #ifdef SQLITE_ENABLE_SQLLOG
3372   if( sqlite3GlobalConfig.xSqllog ){
3373     /* Opening a db handle. Fourth parameter is passed 0. */
3374     void *pArg = sqlite3GlobalConfig.pSqllogArg;
3375     sqlite3GlobalConfig.xSqllog(pArg, db, zFilename, 0);
3376   }
3377 #endif
3378   sqlite3_free_filename(zOpen);
3379   return rc & 0xff;
3380 }
3381 
3382 
3383 /*
3384 ** Open a new database handle.
3385 */
3386 int sqlite3_open(
3387   const char *zFilename,
3388   sqlite3 **ppDb
3389 ){
3390   return openDatabase(zFilename, ppDb,
3391                       SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
3392 }
3393 int sqlite3_open_v2(
3394   const char *filename,   /* Database filename (UTF-8) */
3395   sqlite3 **ppDb,         /* OUT: SQLite db handle */
3396   int flags,              /* Flags */
3397   const char *zVfs        /* Name of VFS module to use */
3398 ){
3399   return openDatabase(filename, ppDb, (unsigned int)flags, zVfs);
3400 }
3401 
3402 #ifndef SQLITE_OMIT_UTF16
3403 /*
3404 ** Open a new database handle.
3405 */
3406 int sqlite3_open16(
3407   const void *zFilename,
3408   sqlite3 **ppDb
3409 ){
3410   char const *zFilename8;   /* zFilename encoded in UTF-8 instead of UTF-16 */
3411   sqlite3_value *pVal;
3412   int rc;
3413 
3414 #ifdef SQLITE_ENABLE_API_ARMOR
3415   if( ppDb==0 ) return SQLITE_MISUSE_BKPT;
3416 #endif
3417   *ppDb = 0;
3418 #ifndef SQLITE_OMIT_AUTOINIT
3419   rc = sqlite3_initialize();
3420   if( rc ) return rc;
3421 #endif
3422   if( zFilename==0 ) zFilename = "\000\000";
3423   pVal = sqlite3ValueNew(0);
3424   sqlite3ValueSetStr(pVal, -1, zFilename, SQLITE_UTF16NATIVE, SQLITE_STATIC);
3425   zFilename8 = sqlite3ValueText(pVal, SQLITE_UTF8);
3426   if( zFilename8 ){
3427     rc = openDatabase(zFilename8, ppDb,
3428                       SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
3429     assert( *ppDb || rc==SQLITE_NOMEM );
3430     if( rc==SQLITE_OK && !DbHasProperty(*ppDb, 0, DB_SchemaLoaded) ){
3431       SCHEMA_ENC(*ppDb) = ENC(*ppDb) = SQLITE_UTF16NATIVE;
3432     }
3433   }else{
3434     rc = SQLITE_NOMEM_BKPT;
3435   }
3436   sqlite3ValueFree(pVal);
3437 
3438   return rc & 0xff;
3439 }
3440 #endif /* SQLITE_OMIT_UTF16 */
3441 
3442 /*
3443 ** Register a new collation sequence with the database handle db.
3444 */
3445 int sqlite3_create_collation(
3446   sqlite3* db,
3447   const char *zName,
3448   int enc,
3449   void* pCtx,
3450   int(*xCompare)(void*,int,const void*,int,const void*)
3451 ){
3452   return sqlite3_create_collation_v2(db, zName, enc, pCtx, xCompare, 0);
3453 }
3454 
3455 /*
3456 ** Register a new collation sequence with the database handle db.
3457 */
3458 int sqlite3_create_collation_v2(
3459   sqlite3* db,
3460   const char *zName,
3461   int enc,
3462   void* pCtx,
3463   int(*xCompare)(void*,int,const void*,int,const void*),
3464   void(*xDel)(void*)
3465 ){
3466   int rc;
3467 
3468 #ifdef SQLITE_ENABLE_API_ARMOR
3469   if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
3470 #endif
3471   sqlite3_mutex_enter(db->mutex);
3472   assert( !db->mallocFailed );
3473   rc = createCollation(db, zName, (u8)enc, pCtx, xCompare, xDel);
3474   rc = sqlite3ApiExit(db, rc);
3475   sqlite3_mutex_leave(db->mutex);
3476   return rc;
3477 }
3478 
3479 #ifndef SQLITE_OMIT_UTF16
3480 /*
3481 ** Register a new collation sequence with the database handle db.
3482 */
3483 int sqlite3_create_collation16(
3484   sqlite3* db,
3485   const void *zName,
3486   int enc,
3487   void* pCtx,
3488   int(*xCompare)(void*,int,const void*,int,const void*)
3489 ){
3490   int rc = SQLITE_OK;
3491   char *zName8;
3492 
3493 #ifdef SQLITE_ENABLE_API_ARMOR
3494   if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
3495 #endif
3496   sqlite3_mutex_enter(db->mutex);
3497   assert( !db->mallocFailed );
3498   zName8 = sqlite3Utf16to8(db, zName, -1, SQLITE_UTF16NATIVE);
3499   if( zName8 ){
3500     rc = createCollation(db, zName8, (u8)enc, pCtx, xCompare, 0);
3501     sqlite3DbFree(db, zName8);
3502   }
3503   rc = sqlite3ApiExit(db, rc);
3504   sqlite3_mutex_leave(db->mutex);
3505   return rc;
3506 }
3507 #endif /* SQLITE_OMIT_UTF16 */
3508 
3509 /*
3510 ** Register a collation sequence factory callback with the database handle
3511 ** db. Replace any previously installed collation sequence factory.
3512 */
3513 int sqlite3_collation_needed(
3514   sqlite3 *db,
3515   void *pCollNeededArg,
3516   void(*xCollNeeded)(void*,sqlite3*,int eTextRep,const char*)
3517 ){
3518 #ifdef SQLITE_ENABLE_API_ARMOR
3519   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3520 #endif
3521   sqlite3_mutex_enter(db->mutex);
3522   db->xCollNeeded = xCollNeeded;
3523   db->xCollNeeded16 = 0;
3524   db->pCollNeededArg = pCollNeededArg;
3525   sqlite3_mutex_leave(db->mutex);
3526   return SQLITE_OK;
3527 }
3528 
3529 #ifndef SQLITE_OMIT_UTF16
3530 /*
3531 ** Register a collation sequence factory callback with the database handle
3532 ** db. Replace any previously installed collation sequence factory.
3533 */
3534 int sqlite3_collation_needed16(
3535   sqlite3 *db,
3536   void *pCollNeededArg,
3537   void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*)
3538 ){
3539 #ifdef SQLITE_ENABLE_API_ARMOR
3540   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3541 #endif
3542   sqlite3_mutex_enter(db->mutex);
3543   db->xCollNeeded = 0;
3544   db->xCollNeeded16 = xCollNeeded16;
3545   db->pCollNeededArg = pCollNeededArg;
3546   sqlite3_mutex_leave(db->mutex);
3547   return SQLITE_OK;
3548 }
3549 #endif /* SQLITE_OMIT_UTF16 */
3550 
3551 #ifndef SQLITE_OMIT_DEPRECATED
3552 /*
3553 ** This function is now an anachronism. It used to be used to recover from a
3554 ** malloc() failure, but SQLite now does this automatically.
3555 */
3556 int sqlite3_global_recover(void){
3557   return SQLITE_OK;
3558 }
3559 #endif
3560 
3561 /*
3562 ** Test to see whether or not the database connection is in autocommit
3563 ** mode.  Return TRUE if it is and FALSE if not.  Autocommit mode is on
3564 ** by default.  Autocommit is disabled by a BEGIN statement and reenabled
3565 ** by the next COMMIT or ROLLBACK.
3566 */
3567 int sqlite3_get_autocommit(sqlite3 *db){
3568 #ifdef SQLITE_ENABLE_API_ARMOR
3569   if( !sqlite3SafetyCheckOk(db) ){
3570     (void)SQLITE_MISUSE_BKPT;
3571     return 0;
3572   }
3573 #endif
3574   return db->autoCommit;
3575 }
3576 
3577 /*
3578 ** The following routines are substitutes for constants SQLITE_CORRUPT,
3579 ** SQLITE_MISUSE, SQLITE_CANTOPEN, SQLITE_NOMEM and possibly other error
3580 ** constants.  They serve two purposes:
3581 **
3582 **   1.  Serve as a convenient place to set a breakpoint in a debugger
3583 **       to detect when version error conditions occurs.
3584 **
3585 **   2.  Invoke sqlite3_log() to provide the source code location where
3586 **       a low-level error is first detected.
3587 */
3588 int sqlite3ReportError(int iErr, int lineno, const char *zType){
3589   sqlite3_log(iErr, "%s at line %d of [%.10s]",
3590               zType, lineno, 20+sqlite3_sourceid());
3591   return iErr;
3592 }
3593 int sqlite3CorruptError(int lineno){
3594   testcase( sqlite3GlobalConfig.xLog!=0 );
3595   return sqlite3ReportError(SQLITE_CORRUPT, lineno, "database corruption");
3596 }
3597 int sqlite3MisuseError(int lineno){
3598   testcase( sqlite3GlobalConfig.xLog!=0 );
3599   return sqlite3ReportError(SQLITE_MISUSE, lineno, "misuse");
3600 }
3601 int sqlite3CantopenError(int lineno){
3602   testcase( sqlite3GlobalConfig.xLog!=0 );
3603   return sqlite3ReportError(SQLITE_CANTOPEN, lineno, "cannot open file");
3604 }
3605 #if defined(SQLITE_DEBUG) || defined(SQLITE_ENABLE_CORRUPT_PGNO)
3606 int sqlite3CorruptPgnoError(int lineno, Pgno pgno){
3607   char zMsg[100];
3608   sqlite3_snprintf(sizeof(zMsg), zMsg, "database corruption page %d", pgno);
3609   testcase( sqlite3GlobalConfig.xLog!=0 );
3610   return sqlite3ReportError(SQLITE_CORRUPT, lineno, zMsg);
3611 }
3612 #endif
3613 #ifdef SQLITE_DEBUG
3614 int sqlite3NomemError(int lineno){
3615   testcase( sqlite3GlobalConfig.xLog!=0 );
3616   return sqlite3ReportError(SQLITE_NOMEM, lineno, "OOM");
3617 }
3618 int sqlite3IoerrnomemError(int lineno){
3619   testcase( sqlite3GlobalConfig.xLog!=0 );
3620   return sqlite3ReportError(SQLITE_IOERR_NOMEM, lineno, "I/O OOM error");
3621 }
3622 #endif
3623 
3624 #ifndef SQLITE_OMIT_DEPRECATED
3625 /*
3626 ** This is a convenience routine that makes sure that all thread-specific
3627 ** data for this thread has been deallocated.
3628 **
3629 ** SQLite no longer uses thread-specific data so this routine is now a
3630 ** no-op.  It is retained for historical compatibility.
3631 */
3632 void sqlite3_thread_cleanup(void){
3633 }
3634 #endif
3635 
3636 /*
3637 ** Return meta information about a specific column of a database table.
3638 ** See comment in sqlite3.h (sqlite.h.in) for details.
3639 */
3640 int sqlite3_table_column_metadata(
3641   sqlite3 *db,                /* Connection handle */
3642   const char *zDbName,        /* Database name or NULL */
3643   const char *zTableName,     /* Table name */
3644   const char *zColumnName,    /* Column name */
3645   char const **pzDataType,    /* OUTPUT: Declared data type */
3646   char const **pzCollSeq,     /* OUTPUT: Collation sequence name */
3647   int *pNotNull,              /* OUTPUT: True if NOT NULL constraint exists */
3648   int *pPrimaryKey,           /* OUTPUT: True if column part of PK */
3649   int *pAutoinc               /* OUTPUT: True if column is auto-increment */
3650 ){
3651   int rc;
3652   char *zErrMsg = 0;
3653   Table *pTab = 0;
3654   Column *pCol = 0;
3655   int iCol = 0;
3656   char const *zDataType = 0;
3657   char const *zCollSeq = 0;
3658   int notnull = 0;
3659   int primarykey = 0;
3660   int autoinc = 0;
3661 
3662 
3663 #ifdef SQLITE_ENABLE_API_ARMOR
3664   if( !sqlite3SafetyCheckOk(db) || zTableName==0 ){
3665     return SQLITE_MISUSE_BKPT;
3666   }
3667 #endif
3668 
3669   /* Ensure the database schema has been loaded */
3670   sqlite3_mutex_enter(db->mutex);
3671   sqlite3BtreeEnterAll(db);
3672   rc = sqlite3Init(db, &zErrMsg);
3673   if( SQLITE_OK!=rc ){
3674     goto error_out;
3675   }
3676 
3677   /* Locate the table in question */
3678   pTab = sqlite3FindTable(db, zTableName, zDbName);
3679   if( !pTab || pTab->pSelect ){
3680     pTab = 0;
3681     goto error_out;
3682   }
3683 
3684   /* Find the column for which info is requested */
3685   if( zColumnName==0 ){
3686     /* Query for existance of table only */
3687   }else{
3688     for(iCol=0; iCol<pTab->nCol; iCol++){
3689       pCol = &pTab->aCol[iCol];
3690       if( 0==sqlite3StrICmp(pCol->zName, zColumnName) ){
3691         break;
3692       }
3693     }
3694     if( iCol==pTab->nCol ){
3695       if( HasRowid(pTab) && sqlite3IsRowid(zColumnName) ){
3696         iCol = pTab->iPKey;
3697         pCol = iCol>=0 ? &pTab->aCol[iCol] : 0;
3698       }else{
3699         pTab = 0;
3700         goto error_out;
3701       }
3702     }
3703   }
3704 
3705   /* The following block stores the meta information that will be returned
3706   ** to the caller in local variables zDataType, zCollSeq, notnull, primarykey
3707   ** and autoinc. At this point there are two possibilities:
3708   **
3709   **     1. The specified column name was rowid", "oid" or "_rowid_"
3710   **        and there is no explicitly declared IPK column.
3711   **
3712   **     2. The table is not a view and the column name identified an
3713   **        explicitly declared column. Copy meta information from *pCol.
3714   */
3715   if( pCol ){
3716     zDataType = sqlite3ColumnType(pCol,0);
3717     zCollSeq = pCol->zColl;
3718     notnull = pCol->notNull!=0;
3719     primarykey  = (pCol->colFlags & COLFLAG_PRIMKEY)!=0;
3720     autoinc = pTab->iPKey==iCol && (pTab->tabFlags & TF_Autoincrement)!=0;
3721   }else{
3722     zDataType = "INTEGER";
3723     primarykey = 1;
3724   }
3725   if( !zCollSeq ){
3726     zCollSeq = sqlite3StrBINARY;
3727   }
3728 
3729 error_out:
3730   sqlite3BtreeLeaveAll(db);
3731 
3732   /* Whether the function call succeeded or failed, set the output parameters
3733   ** to whatever their local counterparts contain. If an error did occur,
3734   ** this has the effect of zeroing all output parameters.
3735   */
3736   if( pzDataType ) *pzDataType = zDataType;
3737   if( pzCollSeq ) *pzCollSeq = zCollSeq;
3738   if( pNotNull ) *pNotNull = notnull;
3739   if( pPrimaryKey ) *pPrimaryKey = primarykey;
3740   if( pAutoinc ) *pAutoinc = autoinc;
3741 
3742   if( SQLITE_OK==rc && !pTab ){
3743     sqlite3DbFree(db, zErrMsg);
3744     zErrMsg = sqlite3MPrintf(db, "no such table column: %s.%s", zTableName,
3745         zColumnName);
3746     rc = SQLITE_ERROR;
3747   }
3748   sqlite3ErrorWithMsg(db, rc, (zErrMsg?"%s":0), zErrMsg);
3749   sqlite3DbFree(db, zErrMsg);
3750   rc = sqlite3ApiExit(db, rc);
3751   sqlite3_mutex_leave(db->mutex);
3752   return rc;
3753 }
3754 
3755 /*
3756 ** Sleep for a little while.  Return the amount of time slept.
3757 */
3758 int sqlite3_sleep(int ms){
3759   sqlite3_vfs *pVfs;
3760   int rc;
3761   pVfs = sqlite3_vfs_find(0);
3762   if( pVfs==0 ) return 0;
3763 
3764   /* This function works in milliseconds, but the underlying OsSleep()
3765   ** API uses microseconds. Hence the 1000's.
3766   */
3767   rc = (sqlite3OsSleep(pVfs, 1000*ms)/1000);
3768   return rc;
3769 }
3770 
3771 /*
3772 ** Enable or disable the extended result codes.
3773 */
3774 int sqlite3_extended_result_codes(sqlite3 *db, int onoff){
3775 #ifdef SQLITE_ENABLE_API_ARMOR
3776   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3777 #endif
3778   sqlite3_mutex_enter(db->mutex);
3779   db->errMask = onoff ? 0xffffffff : 0xff;
3780   sqlite3_mutex_leave(db->mutex);
3781   return SQLITE_OK;
3782 }
3783 
3784 /*
3785 ** Invoke the xFileControl method on a particular database.
3786 */
3787 int sqlite3_file_control(sqlite3 *db, const char *zDbName, int op, void *pArg){
3788   int rc = SQLITE_ERROR;
3789   Btree *pBtree;
3790 
3791 #ifdef SQLITE_ENABLE_API_ARMOR
3792   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3793 #endif
3794   sqlite3_mutex_enter(db->mutex);
3795   pBtree = sqlite3DbNameToBtree(db, zDbName);
3796   if( pBtree ){
3797     Pager *pPager;
3798     sqlite3_file *fd;
3799     sqlite3BtreeEnter(pBtree);
3800     pPager = sqlite3BtreePager(pBtree);
3801     assert( pPager!=0 );
3802     fd = sqlite3PagerFile(pPager);
3803     assert( fd!=0 );
3804     if( op==SQLITE_FCNTL_FILE_POINTER ){
3805       *(sqlite3_file**)pArg = fd;
3806       rc = SQLITE_OK;
3807     }else if( op==SQLITE_FCNTL_VFS_POINTER ){
3808       *(sqlite3_vfs**)pArg = sqlite3PagerVfs(pPager);
3809       rc = SQLITE_OK;
3810     }else if( op==SQLITE_FCNTL_JOURNAL_POINTER ){
3811       *(sqlite3_file**)pArg = sqlite3PagerJrnlFile(pPager);
3812       rc = SQLITE_OK;
3813     }else if( op==SQLITE_FCNTL_DATA_VERSION ){
3814       *(unsigned int*)pArg = sqlite3PagerDataVersion(pPager);
3815       rc = SQLITE_OK;
3816     }else if( op==SQLITE_FCNTL_RESERVE_BYTES ){
3817       int iNew = *(int*)pArg;
3818       *(int*)pArg = sqlite3BtreeGetRequestedReserve(pBtree);
3819       if( iNew>=0 && iNew<=255 ){
3820         sqlite3BtreeSetPageSize(pBtree, 0, iNew, 0);
3821       }
3822       rc = SQLITE_OK;
3823     }else{
3824       rc = sqlite3OsFileControl(fd, op, pArg);
3825     }
3826     sqlite3BtreeLeave(pBtree);
3827   }
3828   sqlite3_mutex_leave(db->mutex);
3829   return rc;
3830 }
3831 
3832 /*
3833 ** Interface to the testing logic.
3834 */
3835 int sqlite3_test_control(int op, ...){
3836   int rc = 0;
3837 #ifdef SQLITE_UNTESTABLE
3838   UNUSED_PARAMETER(op);
3839 #else
3840   va_list ap;
3841   va_start(ap, op);
3842   switch( op ){
3843 
3844     /*
3845     ** Save the current state of the PRNG.
3846     */
3847     case SQLITE_TESTCTRL_PRNG_SAVE: {
3848       sqlite3PrngSaveState();
3849       break;
3850     }
3851 
3852     /*
3853     ** Restore the state of the PRNG to the last state saved using
3854     ** PRNG_SAVE.  If PRNG_SAVE has never before been called, then
3855     ** this verb acts like PRNG_RESET.
3856     */
3857     case SQLITE_TESTCTRL_PRNG_RESTORE: {
3858       sqlite3PrngRestoreState();
3859       break;
3860     }
3861 
3862     /*  sqlite3_test_control(SQLITE_TESTCTRL_PRNG_SEED, int x, sqlite3 *db);
3863     **
3864     ** Control the seed for the pseudo-random number generator (PRNG) that
3865     ** is built into SQLite.  Cases:
3866     **
3867     **    x!=0 && db!=0       Seed the PRNG to the current value of the
3868     **                        schema cookie in the main database for db, or
3869     **                        x if the schema cookie is zero.  This case
3870     **                        is convenient to use with database fuzzers
3871     **                        as it allows the fuzzer some control over the
3872     **                        the PRNG seed.
3873     **
3874     **    x!=0 && db==0       Seed the PRNG to the value of x.
3875     **
3876     **    x==0 && db==0       Revert to default behavior of using the
3877     **                        xRandomness method on the primary VFS.
3878     **
3879     ** This test-control also resets the PRNG so that the new seed will
3880     ** be used for the next call to sqlite3_randomness().
3881     */
3882 #ifndef SQLITE_OMIT_WSD
3883     case SQLITE_TESTCTRL_PRNG_SEED: {
3884       int x = va_arg(ap, int);
3885       int y;
3886       sqlite3 *db = va_arg(ap, sqlite3*);
3887       assert( db==0 || db->aDb[0].pSchema!=0 );
3888       if( db && (y = db->aDb[0].pSchema->schema_cookie)!=0 ){ x = y; }
3889       sqlite3Config.iPrngSeed = x;
3890       sqlite3_randomness(0,0);
3891       break;
3892     }
3893 #endif
3894 
3895     /*
3896     **  sqlite3_test_control(BITVEC_TEST, size, program)
3897     **
3898     ** Run a test against a Bitvec object of size.  The program argument
3899     ** is an array of integers that defines the test.  Return -1 on a
3900     ** memory allocation error, 0 on success, or non-zero for an error.
3901     ** See the sqlite3BitvecBuiltinTest() for additional information.
3902     */
3903     case SQLITE_TESTCTRL_BITVEC_TEST: {
3904       int sz = va_arg(ap, int);
3905       int *aProg = va_arg(ap, int*);
3906       rc = sqlite3BitvecBuiltinTest(sz, aProg);
3907       break;
3908     }
3909 
3910     /*
3911     **  sqlite3_test_control(FAULT_INSTALL, xCallback)
3912     **
3913     ** Arrange to invoke xCallback() whenever sqlite3FaultSim() is called,
3914     ** if xCallback is not NULL.
3915     **
3916     ** As a test of the fault simulator mechanism itself, sqlite3FaultSim(0)
3917     ** is called immediately after installing the new callback and the return
3918     ** value from sqlite3FaultSim(0) becomes the return from
3919     ** sqlite3_test_control().
3920     */
3921     case SQLITE_TESTCTRL_FAULT_INSTALL: {
3922       /* MSVC is picky about pulling func ptrs from va lists.
3923       ** http://support.microsoft.com/kb/47961
3924       ** sqlite3GlobalConfig.xTestCallback = va_arg(ap, int(*)(int));
3925       */
3926       typedef int(*TESTCALLBACKFUNC_t)(int);
3927       sqlite3GlobalConfig.xTestCallback = va_arg(ap, TESTCALLBACKFUNC_t);
3928       rc = sqlite3FaultSim(0);
3929       break;
3930     }
3931 
3932     /*
3933     **  sqlite3_test_control(BENIGN_MALLOC_HOOKS, xBegin, xEnd)
3934     **
3935     ** Register hooks to call to indicate which malloc() failures
3936     ** are benign.
3937     */
3938     case SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS: {
3939       typedef void (*void_function)(void);
3940       void_function xBenignBegin;
3941       void_function xBenignEnd;
3942       xBenignBegin = va_arg(ap, void_function);
3943       xBenignEnd = va_arg(ap, void_function);
3944       sqlite3BenignMallocHooks(xBenignBegin, xBenignEnd);
3945       break;
3946     }
3947 
3948     /*
3949     **  sqlite3_test_control(SQLITE_TESTCTRL_PENDING_BYTE, unsigned int X)
3950     **
3951     ** Set the PENDING byte to the value in the argument, if X>0.
3952     ** Make no changes if X==0.  Return the value of the pending byte
3953     ** as it existing before this routine was called.
3954     **
3955     ** IMPORTANT:  Changing the PENDING byte from 0x40000000 results in
3956     ** an incompatible database file format.  Changing the PENDING byte
3957     ** while any database connection is open results in undefined and
3958     ** deleterious behavior.
3959     */
3960     case SQLITE_TESTCTRL_PENDING_BYTE: {
3961       rc = PENDING_BYTE;
3962 #ifndef SQLITE_OMIT_WSD
3963       {
3964         unsigned int newVal = va_arg(ap, unsigned int);
3965         if( newVal ) sqlite3PendingByte = newVal;
3966       }
3967 #endif
3968       break;
3969     }
3970 
3971     /*
3972     **  sqlite3_test_control(SQLITE_TESTCTRL_ASSERT, int X)
3973     **
3974     ** This action provides a run-time test to see whether or not
3975     ** assert() was enabled at compile-time.  If X is true and assert()
3976     ** is enabled, then the return value is true.  If X is true and
3977     ** assert() is disabled, then the return value is zero.  If X is
3978     ** false and assert() is enabled, then the assertion fires and the
3979     ** process aborts.  If X is false and assert() is disabled, then the
3980     ** return value is zero.
3981     */
3982     case SQLITE_TESTCTRL_ASSERT: {
3983       volatile int x = 0;
3984       assert( /*side-effects-ok*/ (x = va_arg(ap,int))!=0 );
3985       rc = x;
3986       break;
3987     }
3988 
3989 
3990     /*
3991     **  sqlite3_test_control(SQLITE_TESTCTRL_ALWAYS, int X)
3992     **
3993     ** This action provides a run-time test to see how the ALWAYS and
3994     ** NEVER macros were defined at compile-time.
3995     **
3996     ** The return value is ALWAYS(X) if X is true, or 0 if X is false.
3997     **
3998     ** The recommended test is X==2.  If the return value is 2, that means
3999     ** ALWAYS() and NEVER() are both no-op pass-through macros, which is the
4000     ** default setting.  If the return value is 1, then ALWAYS() is either
4001     ** hard-coded to true or else it asserts if its argument is false.
4002     ** The first behavior (hard-coded to true) is the case if
4003     ** SQLITE_TESTCTRL_ASSERT shows that assert() is disabled and the second
4004     ** behavior (assert if the argument to ALWAYS() is false) is the case if
4005     ** SQLITE_TESTCTRL_ASSERT shows that assert() is enabled.
4006     **
4007     ** The run-time test procedure might look something like this:
4008     **
4009     **    if( sqlite3_test_control(SQLITE_TESTCTRL_ALWAYS, 2)==2 ){
4010     **      // ALWAYS() and NEVER() are no-op pass-through macros
4011     **    }else if( sqlite3_test_control(SQLITE_TESTCTRL_ASSERT, 1) ){
4012     **      // ALWAYS(x) asserts that x is true. NEVER(x) asserts x is false.
4013     **    }else{
4014     **      // ALWAYS(x) is a constant 1.  NEVER(x) is a constant 0.
4015     **    }
4016     */
4017     case SQLITE_TESTCTRL_ALWAYS: {
4018       int x = va_arg(ap,int);
4019       rc = x ? ALWAYS(x) : 0;
4020       break;
4021     }
4022 
4023     /*
4024     **   sqlite3_test_control(SQLITE_TESTCTRL_BYTEORDER);
4025     **
4026     ** The integer returned reveals the byte-order of the computer on which
4027     ** SQLite is running:
4028     **
4029     **       1     big-endian,    determined at run-time
4030     **      10     little-endian, determined at run-time
4031     **  432101     big-endian,    determined at compile-time
4032     **  123410     little-endian, determined at compile-time
4033     */
4034     case SQLITE_TESTCTRL_BYTEORDER: {
4035       rc = SQLITE_BYTEORDER*100 + SQLITE_LITTLEENDIAN*10 + SQLITE_BIGENDIAN;
4036       break;
4037     }
4038 
4039     /*  sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS, sqlite3 *db, int N)
4040     **
4041     ** Enable or disable various optimizations for testing purposes.  The
4042     ** argument N is a bitmask of optimizations to be disabled.  For normal
4043     ** operation N should be 0.  The idea is that a test program (like the
4044     ** SQL Logic Test or SLT test module) can run the same SQL multiple times
4045     ** with various optimizations disabled to verify that the same answer
4046     ** is obtained in every case.
4047     */
4048     case SQLITE_TESTCTRL_OPTIMIZATIONS: {
4049       sqlite3 *db = va_arg(ap, sqlite3*);
4050       db->dbOptFlags = (u16)(va_arg(ap, int) & 0xffff);
4051       break;
4052     }
4053 
4054     /*   sqlite3_test_control(SQLITE_TESTCTRL_LOCALTIME_FAULT, int onoff);
4055     **
4056     ** If parameter onoff is non-zero, subsequent calls to localtime()
4057     ** and its variants fail. If onoff is zero, undo this setting.
4058     */
4059     case SQLITE_TESTCTRL_LOCALTIME_FAULT: {
4060       sqlite3GlobalConfig.bLocaltimeFault = va_arg(ap, int);
4061       break;
4062     }
4063 
4064     /*   sqlite3_test_control(SQLITE_TESTCTRL_INTERNAL_FUNCTIONS, sqlite3*);
4065     **
4066     ** Toggle the ability to use internal functions on or off for
4067     ** the database connection given in the argument.
4068     */
4069     case SQLITE_TESTCTRL_INTERNAL_FUNCTIONS: {
4070       sqlite3 *db = va_arg(ap, sqlite3*);
4071       db->mDbFlags ^= DBFLAG_InternalFunc;
4072       break;
4073     }
4074 
4075     /*   sqlite3_test_control(SQLITE_TESTCTRL_NEVER_CORRUPT, int);
4076     **
4077     ** Set or clear a flag that indicates that the database file is always well-
4078     ** formed and never corrupt.  This flag is clear by default, indicating that
4079     ** database files might have arbitrary corruption.  Setting the flag during
4080     ** testing causes certain assert() statements in the code to be activated
4081     ** that demonstrat invariants on well-formed database files.
4082     */
4083     case SQLITE_TESTCTRL_NEVER_CORRUPT: {
4084       sqlite3GlobalConfig.neverCorrupt = va_arg(ap, int);
4085       break;
4086     }
4087 
4088     /*   sqlite3_test_control(SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS, int);
4089     **
4090     ** Set or clear a flag that causes SQLite to verify that type, name,
4091     ** and tbl_name fields of the sqlite_master table.  This is normally
4092     ** on, but it is sometimes useful to turn it off for testing.
4093     */
4094     case SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS: {
4095       sqlite3GlobalConfig.bExtraSchemaChecks = va_arg(ap, int);
4096       break;
4097     }
4098 
4099     /* Set the threshold at which OP_Once counters reset back to zero.
4100     ** By default this is 0x7ffffffe (over 2 billion), but that value is
4101     ** too big to test in a reasonable amount of time, so this control is
4102     ** provided to set a small and easily reachable reset value.
4103     */
4104     case SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD: {
4105       sqlite3GlobalConfig.iOnceResetThreshold = va_arg(ap, int);
4106       break;
4107     }
4108 
4109     /*   sqlite3_test_control(SQLITE_TESTCTRL_VDBE_COVERAGE, xCallback, ptr);
4110     **
4111     ** Set the VDBE coverage callback function to xCallback with context
4112     ** pointer ptr.
4113     */
4114     case SQLITE_TESTCTRL_VDBE_COVERAGE: {
4115 #ifdef SQLITE_VDBE_COVERAGE
4116       typedef void (*branch_callback)(void*,unsigned int,
4117                                       unsigned char,unsigned char);
4118       sqlite3GlobalConfig.xVdbeBranch = va_arg(ap,branch_callback);
4119       sqlite3GlobalConfig.pVdbeBranchArg = va_arg(ap,void*);
4120 #endif
4121       break;
4122     }
4123 
4124     /*   sqlite3_test_control(SQLITE_TESTCTRL_SORTER_MMAP, db, nMax); */
4125     case SQLITE_TESTCTRL_SORTER_MMAP: {
4126       sqlite3 *db = va_arg(ap, sqlite3*);
4127       db->nMaxSorterMmap = va_arg(ap, int);
4128       break;
4129     }
4130 
4131     /*   sqlite3_test_control(SQLITE_TESTCTRL_ISINIT);
4132     **
4133     ** Return SQLITE_OK if SQLite has been initialized and SQLITE_ERROR if
4134     ** not.
4135     */
4136     case SQLITE_TESTCTRL_ISINIT: {
4137       if( sqlite3GlobalConfig.isInit==0 ) rc = SQLITE_ERROR;
4138       break;
4139     }
4140 
4141     /*  sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, db, dbName, onOff, tnum);
4142     **
4143     ** This test control is used to create imposter tables.  "db" is a pointer
4144     ** to the database connection.  dbName is the database name (ex: "main" or
4145     ** "temp") which will receive the imposter.  "onOff" turns imposter mode on
4146     ** or off.  "tnum" is the root page of the b-tree to which the imposter
4147     ** table should connect.
4148     **
4149     ** Enable imposter mode only when the schema has already been parsed.  Then
4150     ** run a single CREATE TABLE statement to construct the imposter table in
4151     ** the parsed schema.  Then turn imposter mode back off again.
4152     **
4153     ** If onOff==0 and tnum>0 then reset the schema for all databases, causing
4154     ** the schema to be reparsed the next time it is needed.  This has the
4155     ** effect of erasing all imposter tables.
4156     */
4157     case SQLITE_TESTCTRL_IMPOSTER: {
4158       sqlite3 *db = va_arg(ap, sqlite3*);
4159       sqlite3_mutex_enter(db->mutex);
4160       db->init.iDb = sqlite3FindDbName(db, va_arg(ap,const char*));
4161       db->init.busy = db->init.imposterTable = va_arg(ap,int);
4162       db->init.newTnum = va_arg(ap,int);
4163       if( db->init.busy==0 && db->init.newTnum>0 ){
4164         sqlite3ResetAllSchemasOfConnection(db);
4165       }
4166       sqlite3_mutex_leave(db->mutex);
4167       break;
4168     }
4169 
4170 #if defined(YYCOVERAGE)
4171     /*  sqlite3_test_control(SQLITE_TESTCTRL_PARSER_COVERAGE, FILE *out)
4172     **
4173     ** This test control (only available when SQLite is compiled with
4174     ** -DYYCOVERAGE) writes a report onto "out" that shows all
4175     ** state/lookahead combinations in the parser state machine
4176     ** which are never exercised.  If any state is missed, make the
4177     ** return code SQLITE_ERROR.
4178     */
4179     case SQLITE_TESTCTRL_PARSER_COVERAGE: {
4180       FILE *out = va_arg(ap, FILE*);
4181       if( sqlite3ParserCoverage(out) ) rc = SQLITE_ERROR;
4182       break;
4183     }
4184 #endif /* defined(YYCOVERAGE) */
4185 
4186     /*  sqlite3_test_control(SQLITE_TESTCTRL_RESULT_INTREAL, sqlite3_context*);
4187     **
4188     ** This test-control causes the most recent sqlite3_result_int64() value
4189     ** to be interpreted as a MEM_IntReal instead of as an MEM_Int.  Normally,
4190     ** MEM_IntReal values only arise during an INSERT operation of integer
4191     ** values into a REAL column, so they can be challenging to test.  This
4192     ** test-control enables us to write an intreal() SQL function that can
4193     ** inject an intreal() value at arbitrary places in an SQL statement,
4194     ** for testing purposes.
4195     */
4196     case SQLITE_TESTCTRL_RESULT_INTREAL: {
4197       sqlite3_context *pCtx = va_arg(ap, sqlite3_context*);
4198       sqlite3ResultIntReal(pCtx);
4199       break;
4200     }
4201   }
4202   va_end(ap);
4203 #endif /* SQLITE_UNTESTABLE */
4204   return rc;
4205 }
4206 
4207 /*
4208 ** The Pager stores the Database filename, Journal filename, and WAL filename
4209 ** consecutively in memory, in that order.  The database filename is prefixed
4210 ** by four zero bytes.  Locate the start of the database filename by searching
4211 ** backwards for the first byte following four consecutive zero bytes.
4212 **
4213 ** This only works if the filename passed in was obtained from the Pager.
4214 */
4215 static const char *databaseName(const char *zName){
4216   while( zName[-1]!=0 || zName[-2]!=0 || zName[-3]!=0 || zName[-4]!=0 ){
4217     zName--;
4218   }
4219   return zName;
4220 }
4221 
4222 /*
4223 ** Append text z[] to the end of p[].  Return a pointer to the first
4224 ** character after then zero terminator on the new text in p[].
4225 */
4226 static char *appendText(char *p, const char *z){
4227   size_t n = strlen(z);
4228   memcpy(p, z, n+1);
4229   return p+n+1;
4230 }
4231 
4232 /*
4233 ** Allocate memory to hold names for a database, journal file, WAL file,
4234 ** and query parameters.  The pointer returned is valid for use by
4235 ** sqlite3_filename_database() and sqlite3_uri_parameter() and related
4236 ** functions.
4237 **
4238 ** Memory layout must be compatible with that generated by the pager
4239 ** and expected by sqlite3_uri_parameter() and databaseName().
4240 */
4241 char *sqlite3_create_filename(
4242   const char *zDatabase,
4243   const char *zJournal,
4244   const char *zWal,
4245   int nParam,
4246   const char **azParam
4247 ){
4248   sqlite3_int64 nByte;
4249   int i;
4250   char *pResult, *p;
4251   nByte = strlen(zDatabase) + strlen(zJournal) + strlen(zWal) + 10;
4252   for(i=0; i<nParam*2; i++){
4253     nByte += strlen(azParam[i])+1;
4254   }
4255   pResult = p = sqlite3_malloc64( nByte );
4256   if( p==0 ) return 0;
4257   memset(p, 0, 4);
4258   p += 4;
4259   p = appendText(p, zDatabase);
4260   for(i=0; i<nParam*2; i++){
4261     p = appendText(p, azParam[i]);
4262   }
4263   *(p++) = 0;
4264   p = appendText(p, zJournal);
4265   p = appendText(p, zWal);
4266   *(p++) = 0;
4267   *(p++) = 0;
4268   assert( (sqlite3_int64)(p - pResult)==nByte );
4269   return pResult + 4;
4270 }
4271 
4272 /*
4273 ** Free memory obtained from sqlite3_create_filename().  It is a severe
4274 ** error to call this routine with any parameter other than a pointer
4275 ** previously obtained from sqlite3_create_filename() or a NULL pointer.
4276 */
4277 void sqlite3_free_filename(char *p){
4278   if( p==0 ) return;
4279   p = (char*)databaseName(p);
4280   sqlite3_free(p - 4);
4281 }
4282 
4283 
4284 /*
4285 ** This is a utility routine, useful to VFS implementations, that checks
4286 ** to see if a database file was a URI that contained a specific query
4287 ** parameter, and if so obtains the value of the query parameter.
4288 **
4289 ** The zFilename argument is the filename pointer passed into the xOpen()
4290 ** method of a VFS implementation.  The zParam argument is the name of the
4291 ** query parameter we seek.  This routine returns the value of the zParam
4292 ** parameter if it exists.  If the parameter does not exist, this routine
4293 ** returns a NULL pointer.
4294 */
4295 const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam){
4296   if( zFilename==0 || zParam==0 ) return 0;
4297   zFilename = databaseName(zFilename);
4298   return uriParameter(zFilename, zParam);
4299 }
4300 
4301 /*
4302 ** Return a pointer to the name of Nth query parameter of the filename.
4303 */
4304 const char *sqlite3_uri_key(const char *zFilename, int N){
4305   if( zFilename==0 || N<0 ) return 0;
4306   zFilename = databaseName(zFilename);
4307   zFilename += sqlite3Strlen30(zFilename) + 1;
4308   while( zFilename[0] && (N--)>0 ){
4309     zFilename += sqlite3Strlen30(zFilename) + 1;
4310     zFilename += sqlite3Strlen30(zFilename) + 1;
4311   }
4312   return zFilename[0] ? zFilename : 0;
4313 }
4314 
4315 /*
4316 ** Return a boolean value for a query parameter.
4317 */
4318 int sqlite3_uri_boolean(const char *zFilename, const char *zParam, int bDflt){
4319   const char *z = sqlite3_uri_parameter(zFilename, zParam);
4320   bDflt = bDflt!=0;
4321   return z ? sqlite3GetBoolean(z, bDflt) : bDflt;
4322 }
4323 
4324 /*
4325 ** Return a 64-bit integer value for a query parameter.
4326 */
4327 sqlite3_int64 sqlite3_uri_int64(
4328   const char *zFilename,    /* Filename as passed to xOpen */
4329   const char *zParam,       /* URI parameter sought */
4330   sqlite3_int64 bDflt       /* return if parameter is missing */
4331 ){
4332   const char *z = sqlite3_uri_parameter(zFilename, zParam);
4333   sqlite3_int64 v;
4334   if( z && sqlite3DecOrHexToI64(z, &v)==0 ){
4335     bDflt = v;
4336   }
4337   return bDflt;
4338 }
4339 
4340 /*
4341 ** Translate a filename that was handed to a VFS routine into the corresponding
4342 ** database, journal, or WAL file.
4343 **
4344 ** It is an error to pass this routine a filename string that was not
4345 ** passed into the VFS from the SQLite core.  Doing so is similar to
4346 ** passing free() a pointer that was not obtained from malloc() - it is
4347 ** an error that we cannot easily detect but that will likely cause memory
4348 ** corruption.
4349 */
4350 const char *sqlite3_filename_database(const char *zFilename){
4351   return databaseName(zFilename);
4352 }
4353 const char *sqlite3_filename_journal(const char *zFilename){
4354   zFilename = databaseName(zFilename);
4355   zFilename += sqlite3Strlen30(zFilename) + 1;
4356   while( zFilename[0] ){
4357     zFilename += sqlite3Strlen30(zFilename) + 1;
4358     zFilename += sqlite3Strlen30(zFilename) + 1;
4359   }
4360   return zFilename + 1;
4361 }
4362 const char *sqlite3_filename_wal(const char *zFilename){
4363 #ifdef SQLITE_OMIT_WAL
4364   return 0;
4365 #else
4366   zFilename = sqlite3_filename_journal(zFilename);
4367   zFilename += sqlite3Strlen30(zFilename) + 1;
4368   return zFilename;
4369 #endif
4370 }
4371 
4372 /*
4373 ** Return the Btree pointer identified by zDbName.  Return NULL if not found.
4374 */
4375 Btree *sqlite3DbNameToBtree(sqlite3 *db, const char *zDbName){
4376   int iDb = zDbName ? sqlite3FindDbName(db, zDbName) : 0;
4377   return iDb<0 ? 0 : db->aDb[iDb].pBt;
4378 }
4379 
4380 /*
4381 ** Return the filename of the database associated with a database
4382 ** connection.
4383 */
4384 const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName){
4385   Btree *pBt;
4386 #ifdef SQLITE_ENABLE_API_ARMOR
4387   if( !sqlite3SafetyCheckOk(db) ){
4388     (void)SQLITE_MISUSE_BKPT;
4389     return 0;
4390   }
4391 #endif
4392   pBt = sqlite3DbNameToBtree(db, zDbName);
4393   return pBt ? sqlite3BtreeGetFilename(pBt) : 0;
4394 }
4395 
4396 /*
4397 ** Return 1 if database is read-only or 0 if read/write.  Return -1 if
4398 ** no such database exists.
4399 */
4400 int sqlite3_db_readonly(sqlite3 *db, const char *zDbName){
4401   Btree *pBt;
4402 #ifdef SQLITE_ENABLE_API_ARMOR
4403   if( !sqlite3SafetyCheckOk(db) ){
4404     (void)SQLITE_MISUSE_BKPT;
4405     return -1;
4406   }
4407 #endif
4408   pBt = sqlite3DbNameToBtree(db, zDbName);
4409   return pBt ? sqlite3BtreeIsReadonly(pBt) : -1;
4410 }
4411 
4412 #ifdef SQLITE_ENABLE_SNAPSHOT
4413 /*
4414 ** Obtain a snapshot handle for the snapshot of database zDb currently
4415 ** being read by handle db.
4416 */
4417 int sqlite3_snapshot_get(
4418   sqlite3 *db,
4419   const char *zDb,
4420   sqlite3_snapshot **ppSnapshot
4421 ){
4422   int rc = SQLITE_ERROR;
4423 #ifndef SQLITE_OMIT_WAL
4424 
4425 #ifdef SQLITE_ENABLE_API_ARMOR
4426   if( !sqlite3SafetyCheckOk(db) ){
4427     return SQLITE_MISUSE_BKPT;
4428   }
4429 #endif
4430   sqlite3_mutex_enter(db->mutex);
4431 
4432   if( db->autoCommit==0 ){
4433     int iDb = sqlite3FindDbName(db, zDb);
4434     if( iDb==0 || iDb>1 ){
4435       Btree *pBt = db->aDb[iDb].pBt;
4436       if( 0==sqlite3BtreeIsInTrans(pBt) ){
4437         rc = sqlite3BtreeBeginTrans(pBt, 0, 0);
4438         if( rc==SQLITE_OK ){
4439           rc = sqlite3PagerSnapshotGet(sqlite3BtreePager(pBt), ppSnapshot);
4440         }
4441       }
4442     }
4443   }
4444 
4445   sqlite3_mutex_leave(db->mutex);
4446 #endif   /* SQLITE_OMIT_WAL */
4447   return rc;
4448 }
4449 
4450 /*
4451 ** Open a read-transaction on the snapshot idendified by pSnapshot.
4452 */
4453 int sqlite3_snapshot_open(
4454   sqlite3 *db,
4455   const char *zDb,
4456   sqlite3_snapshot *pSnapshot
4457 ){
4458   int rc = SQLITE_ERROR;
4459 #ifndef SQLITE_OMIT_WAL
4460 
4461 #ifdef SQLITE_ENABLE_API_ARMOR
4462   if( !sqlite3SafetyCheckOk(db) ){
4463     return SQLITE_MISUSE_BKPT;
4464   }
4465 #endif
4466   sqlite3_mutex_enter(db->mutex);
4467   if( db->autoCommit==0 ){
4468     int iDb;
4469     iDb = sqlite3FindDbName(db, zDb);
4470     if( iDb==0 || iDb>1 ){
4471       Btree *pBt = db->aDb[iDb].pBt;
4472       if( sqlite3BtreeIsInTrans(pBt)==0 ){
4473         Pager *pPager = sqlite3BtreePager(pBt);
4474         int bUnlock = 0;
4475         if( sqlite3BtreeIsInReadTrans(pBt) ){
4476           if( db->nVdbeActive==0 ){
4477             rc = sqlite3PagerSnapshotCheck(pPager, pSnapshot);
4478             if( rc==SQLITE_OK ){
4479               bUnlock = 1;
4480               rc = sqlite3BtreeCommit(pBt);
4481             }
4482           }
4483         }else{
4484           rc = SQLITE_OK;
4485         }
4486         if( rc==SQLITE_OK ){
4487           rc = sqlite3PagerSnapshotOpen(pPager, pSnapshot);
4488         }
4489         if( rc==SQLITE_OK ){
4490           rc = sqlite3BtreeBeginTrans(pBt, 0, 0);
4491           sqlite3PagerSnapshotOpen(pPager, 0);
4492         }
4493         if( bUnlock ){
4494           sqlite3PagerSnapshotUnlock(pPager);
4495         }
4496       }
4497     }
4498   }
4499 
4500   sqlite3_mutex_leave(db->mutex);
4501 #endif   /* SQLITE_OMIT_WAL */
4502   return rc;
4503 }
4504 
4505 /*
4506 ** Recover as many snapshots as possible from the wal file associated with
4507 ** schema zDb of database db.
4508 */
4509 int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb){
4510   int rc = SQLITE_ERROR;
4511   int iDb;
4512 #ifndef SQLITE_OMIT_WAL
4513 
4514 #ifdef SQLITE_ENABLE_API_ARMOR
4515   if( !sqlite3SafetyCheckOk(db) ){
4516     return SQLITE_MISUSE_BKPT;
4517   }
4518 #endif
4519 
4520   sqlite3_mutex_enter(db->mutex);
4521   iDb = sqlite3FindDbName(db, zDb);
4522   if( iDb==0 || iDb>1 ){
4523     Btree *pBt = db->aDb[iDb].pBt;
4524     if( 0==sqlite3BtreeIsInReadTrans(pBt) ){
4525       rc = sqlite3BtreeBeginTrans(pBt, 0, 0);
4526       if( rc==SQLITE_OK ){
4527         rc = sqlite3PagerSnapshotRecover(sqlite3BtreePager(pBt));
4528         sqlite3BtreeCommit(pBt);
4529       }
4530     }
4531   }
4532   sqlite3_mutex_leave(db->mutex);
4533 #endif   /* SQLITE_OMIT_WAL */
4534   return rc;
4535 }
4536 
4537 /*
4538 ** Free a snapshot handle obtained from sqlite3_snapshot_get().
4539 */
4540 void sqlite3_snapshot_free(sqlite3_snapshot *pSnapshot){
4541   sqlite3_free(pSnapshot);
4542 }
4543 #endif /* SQLITE_ENABLE_SNAPSHOT */
4544 
4545 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
4546 /*
4547 ** Given the name of a compile-time option, return true if that option
4548 ** was used and false if not.
4549 **
4550 ** The name can optionally begin with "SQLITE_" but the "SQLITE_" prefix
4551 ** is not required for a match.
4552 */
4553 int sqlite3_compileoption_used(const char *zOptName){
4554   int i, n;
4555   int nOpt;
4556   const char **azCompileOpt;
4557 
4558 #if SQLITE_ENABLE_API_ARMOR
4559   if( zOptName==0 ){
4560     (void)SQLITE_MISUSE_BKPT;
4561     return 0;
4562   }
4563 #endif
4564 
4565   azCompileOpt = sqlite3CompileOptions(&nOpt);
4566 
4567   if( sqlite3StrNICmp(zOptName, "SQLITE_", 7)==0 ) zOptName += 7;
4568   n = sqlite3Strlen30(zOptName);
4569 
4570   /* Since nOpt is normally in single digits, a linear search is
4571   ** adequate. No need for a binary search. */
4572   for(i=0; i<nOpt; i++){
4573     if( sqlite3StrNICmp(zOptName, azCompileOpt[i], n)==0
4574      && sqlite3IsIdChar((unsigned char)azCompileOpt[i][n])==0
4575     ){
4576       return 1;
4577     }
4578   }
4579   return 0;
4580 }
4581 
4582 /*
4583 ** Return the N-th compile-time option string.  If N is out of range,
4584 ** return a NULL pointer.
4585 */
4586 const char *sqlite3_compileoption_get(int N){
4587   int nOpt;
4588   const char **azCompileOpt;
4589   azCompileOpt = sqlite3CompileOptions(&nOpt);
4590   if( N>=0 && N<nOpt ){
4591     return azCompileOpt[N];
4592   }
4593   return 0;
4594 }
4595 #endif /* SQLITE_OMIT_COMPILEOPTION_DIAGS */
4596