xref: /sqlite-3.40.0/src/main.c (revision 5f0d37b5)
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 *pMainMtx; )      /* 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_MAIN 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( pMainMtx = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MAIN); )
250   sqlite3_mutex_enter(pMainMtx);
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(pMainMtx);
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       sqlite3MemoryBarrier();
317       sqlite3GlobalConfig.isInit = 1;
318 #ifdef SQLITE_EXTRA_INIT
319       bRunExtraInit = 1;
320 #endif
321     }
322     sqlite3GlobalConfig.inProgress = 0;
323   }
324   sqlite3_mutex_leave(sqlite3GlobalConfig.pInitMutex);
325 
326   /* Go back under the static mutex and clean up the recursive
327   ** mutex to prevent a resource leak.
328   */
329   sqlite3_mutex_enter(pMainMtx);
330   sqlite3GlobalConfig.nRefInitMutex--;
331   if( sqlite3GlobalConfig.nRefInitMutex<=0 ){
332     assert( sqlite3GlobalConfig.nRefInitMutex==0 );
333     sqlite3_mutex_free(sqlite3GlobalConfig.pInitMutex);
334     sqlite3GlobalConfig.pInitMutex = 0;
335   }
336   sqlite3_mutex_leave(pMainMtx);
337 
338   /* The following is just a sanity check to make sure SQLite has
339   ** been compiled correctly.  It is important to run this code, but
340   ** we don't want to run it too often and soak up CPU cycles for no
341   ** reason.  So we run it once during initialization.
342   */
343 #ifndef NDEBUG
344 #ifndef SQLITE_OMIT_FLOATING_POINT
345   /* This section of code's only "output" is via assert() statements. */
346   if( rc==SQLITE_OK ){
347     u64 x = (((u64)1)<<63)-1;
348     double y;
349     assert(sizeof(x)==8);
350     assert(sizeof(x)==sizeof(y));
351     memcpy(&y, &x, 8);
352     assert( sqlite3IsNaN(y) );
353   }
354 #endif
355 #endif
356 
357   /* Do extra initialization steps requested by the SQLITE_EXTRA_INIT
358   ** compile-time option.
359   */
360 #ifdef SQLITE_EXTRA_INIT
361   if( bRunExtraInit ){
362     int SQLITE_EXTRA_INIT(const char*);
363     rc = SQLITE_EXTRA_INIT(0);
364   }
365 #endif
366 
367   return rc;
368 }
369 
370 /*
371 ** Undo the effects of sqlite3_initialize().  Must not be called while
372 ** there are outstanding database connections or memory allocations or
373 ** while any part of SQLite is otherwise in use in any thread.  This
374 ** routine is not threadsafe.  But it is safe to invoke this routine
375 ** on when SQLite is already shut down.  If SQLite is already shut down
376 ** when this routine is invoked, then this routine is a harmless no-op.
377 */
378 int sqlite3_shutdown(void){
379 #ifdef SQLITE_OMIT_WSD
380   int rc = sqlite3_wsd_init(4096, 24);
381   if( rc!=SQLITE_OK ){
382     return rc;
383   }
384 #endif
385 
386   if( sqlite3GlobalConfig.isInit ){
387 #ifdef SQLITE_EXTRA_SHUTDOWN
388     void SQLITE_EXTRA_SHUTDOWN(void);
389     SQLITE_EXTRA_SHUTDOWN();
390 #endif
391     sqlite3_os_end();
392     sqlite3_reset_auto_extension();
393     sqlite3GlobalConfig.isInit = 0;
394   }
395   if( sqlite3GlobalConfig.isPCacheInit ){
396     sqlite3PcacheShutdown();
397     sqlite3GlobalConfig.isPCacheInit = 0;
398   }
399   if( sqlite3GlobalConfig.isMallocInit ){
400     sqlite3MallocEnd();
401     sqlite3GlobalConfig.isMallocInit = 0;
402 
403 #ifndef SQLITE_OMIT_SHUTDOWN_DIRECTORIES
404     /* The heap subsystem has now been shutdown and these values are supposed
405     ** to be NULL or point to memory that was obtained from sqlite3_malloc(),
406     ** which would rely on that heap subsystem; therefore, make sure these
407     ** values cannot refer to heap memory that was just invalidated when the
408     ** heap subsystem was shutdown.  This is only done if the current call to
409     ** this function resulted in the heap subsystem actually being shutdown.
410     */
411     sqlite3_data_directory = 0;
412     sqlite3_temp_directory = 0;
413 #endif
414   }
415   if( sqlite3GlobalConfig.isMutexInit ){
416     sqlite3MutexEnd();
417     sqlite3GlobalConfig.isMutexInit = 0;
418   }
419 
420   return SQLITE_OK;
421 }
422 
423 /*
424 ** This API allows applications to modify the global configuration of
425 ** the SQLite library at run-time.
426 **
427 ** This routine should only be called when there are no outstanding
428 ** database connections or memory allocations.  This routine is not
429 ** threadsafe.  Failure to heed these warnings can lead to unpredictable
430 ** behavior.
431 */
432 int sqlite3_config(int op, ...){
433   va_list ap;
434   int rc = SQLITE_OK;
435 
436   /* sqlite3_config() shall return SQLITE_MISUSE if it is invoked while
437   ** the SQLite library is in use. */
438   if( sqlite3GlobalConfig.isInit ) return SQLITE_MISUSE_BKPT;
439 
440   va_start(ap, op);
441   switch( op ){
442 
443     /* Mutex configuration options are only available in a threadsafe
444     ** compile.
445     */
446 #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0  /* IMP: R-54466-46756 */
447     case SQLITE_CONFIG_SINGLETHREAD: {
448       /* EVIDENCE-OF: R-02748-19096 This option sets the threading mode to
449       ** Single-thread. */
450       sqlite3GlobalConfig.bCoreMutex = 0;  /* Disable mutex on core */
451       sqlite3GlobalConfig.bFullMutex = 0;  /* Disable mutex on connections */
452       break;
453     }
454 #endif
455 #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-20520-54086 */
456     case SQLITE_CONFIG_MULTITHREAD: {
457       /* EVIDENCE-OF: R-14374-42468 This option sets the threading mode to
458       ** Multi-thread. */
459       sqlite3GlobalConfig.bCoreMutex = 1;  /* Enable mutex on core */
460       sqlite3GlobalConfig.bFullMutex = 0;  /* Disable mutex on connections */
461       break;
462     }
463 #endif
464 #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-59593-21810 */
465     case SQLITE_CONFIG_SERIALIZED: {
466       /* EVIDENCE-OF: R-41220-51800 This option sets the threading mode to
467       ** Serialized. */
468       sqlite3GlobalConfig.bCoreMutex = 1;  /* Enable mutex on core */
469       sqlite3GlobalConfig.bFullMutex = 1;  /* Enable mutex on connections */
470       break;
471     }
472 #endif
473 #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-63666-48755 */
474     case SQLITE_CONFIG_MUTEX: {
475       /* Specify an alternative mutex implementation */
476       sqlite3GlobalConfig.mutex = *va_arg(ap, sqlite3_mutex_methods*);
477       break;
478     }
479 #endif
480 #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-14450-37597 */
481     case SQLITE_CONFIG_GETMUTEX: {
482       /* Retrieve the current mutex implementation */
483       *va_arg(ap, sqlite3_mutex_methods*) = sqlite3GlobalConfig.mutex;
484       break;
485     }
486 #endif
487 
488     case SQLITE_CONFIG_MALLOC: {
489       /* EVIDENCE-OF: R-55594-21030 The SQLITE_CONFIG_MALLOC option takes a
490       ** single argument which is a pointer to an instance of the
491       ** sqlite3_mem_methods structure. The argument specifies alternative
492       ** low-level memory allocation routines to be used in place of the memory
493       ** allocation routines built into SQLite. */
494       sqlite3GlobalConfig.m = *va_arg(ap, sqlite3_mem_methods*);
495       break;
496     }
497     case SQLITE_CONFIG_GETMALLOC: {
498       /* EVIDENCE-OF: R-51213-46414 The SQLITE_CONFIG_GETMALLOC option takes a
499       ** single argument which is a pointer to an instance of the
500       ** sqlite3_mem_methods structure. The sqlite3_mem_methods structure is
501       ** filled with the currently defined memory allocation routines. */
502       if( sqlite3GlobalConfig.m.xMalloc==0 ) sqlite3MemSetDefault();
503       *va_arg(ap, sqlite3_mem_methods*) = sqlite3GlobalConfig.m;
504       break;
505     }
506     case SQLITE_CONFIG_MEMSTATUS: {
507       /* EVIDENCE-OF: R-61275-35157 The SQLITE_CONFIG_MEMSTATUS option takes
508       ** single argument of type int, interpreted as a boolean, which enables
509       ** or disables the collection of memory allocation statistics. */
510       sqlite3GlobalConfig.bMemstat = va_arg(ap, int);
511       break;
512     }
513     case SQLITE_CONFIG_SMALL_MALLOC: {
514       sqlite3GlobalConfig.bSmallMalloc = va_arg(ap, int);
515       break;
516     }
517     case SQLITE_CONFIG_PAGECACHE: {
518       /* EVIDENCE-OF: R-18761-36601 There are three arguments to
519       ** SQLITE_CONFIG_PAGECACHE: A pointer to 8-byte aligned memory (pMem),
520       ** the size of each page cache line (sz), and the number of cache lines
521       ** (N). */
522       sqlite3GlobalConfig.pPage = va_arg(ap, void*);
523       sqlite3GlobalConfig.szPage = va_arg(ap, int);
524       sqlite3GlobalConfig.nPage = va_arg(ap, int);
525       break;
526     }
527     case SQLITE_CONFIG_PCACHE_HDRSZ: {
528       /* EVIDENCE-OF: R-39100-27317 The SQLITE_CONFIG_PCACHE_HDRSZ option takes
529       ** a single parameter which is a pointer to an integer and writes into
530       ** that integer the number of extra bytes per page required for each page
531       ** in SQLITE_CONFIG_PAGECACHE. */
532       *va_arg(ap, int*) =
533           sqlite3HeaderSizeBtree() +
534           sqlite3HeaderSizePcache() +
535           sqlite3HeaderSizePcache1();
536       break;
537     }
538 
539     case SQLITE_CONFIG_PCACHE: {
540       /* no-op */
541       break;
542     }
543     case SQLITE_CONFIG_GETPCACHE: {
544       /* now an error */
545       rc = SQLITE_ERROR;
546       break;
547     }
548 
549     case SQLITE_CONFIG_PCACHE2: {
550       /* EVIDENCE-OF: R-63325-48378 The SQLITE_CONFIG_PCACHE2 option takes a
551       ** single argument which is a pointer to an sqlite3_pcache_methods2
552       ** object. This object specifies the interface to a custom page cache
553       ** implementation. */
554       sqlite3GlobalConfig.pcache2 = *va_arg(ap, sqlite3_pcache_methods2*);
555       break;
556     }
557     case SQLITE_CONFIG_GETPCACHE2: {
558       /* EVIDENCE-OF: R-22035-46182 The SQLITE_CONFIG_GETPCACHE2 option takes a
559       ** single argument which is a pointer to an sqlite3_pcache_methods2
560       ** object. SQLite copies of the current page cache implementation into
561       ** that object. */
562       if( sqlite3GlobalConfig.pcache2.xInit==0 ){
563         sqlite3PCacheSetDefault();
564       }
565       *va_arg(ap, sqlite3_pcache_methods2*) = sqlite3GlobalConfig.pcache2;
566       break;
567     }
568 
569 /* EVIDENCE-OF: R-06626-12911 The SQLITE_CONFIG_HEAP option is only
570 ** available if SQLite is compiled with either SQLITE_ENABLE_MEMSYS3 or
571 ** SQLITE_ENABLE_MEMSYS5 and returns SQLITE_ERROR if invoked otherwise. */
572 #if defined(SQLITE_ENABLE_MEMSYS3) || defined(SQLITE_ENABLE_MEMSYS5)
573     case SQLITE_CONFIG_HEAP: {
574       /* EVIDENCE-OF: R-19854-42126 There are three arguments to
575       ** SQLITE_CONFIG_HEAP: An 8-byte aligned pointer to the memory, the
576       ** number of bytes in the memory buffer, and the minimum allocation size.
577       */
578       sqlite3GlobalConfig.pHeap = va_arg(ap, void*);
579       sqlite3GlobalConfig.nHeap = va_arg(ap, int);
580       sqlite3GlobalConfig.mnReq = va_arg(ap, int);
581 
582       if( sqlite3GlobalConfig.mnReq<1 ){
583         sqlite3GlobalConfig.mnReq = 1;
584       }else if( sqlite3GlobalConfig.mnReq>(1<<12) ){
585         /* cap min request size at 2^12 */
586         sqlite3GlobalConfig.mnReq = (1<<12);
587       }
588 
589       if( sqlite3GlobalConfig.pHeap==0 ){
590         /* EVIDENCE-OF: R-49920-60189 If the first pointer (the memory pointer)
591         ** is NULL, then SQLite reverts to using its default memory allocator
592         ** (the system malloc() implementation), undoing any prior invocation of
593         ** SQLITE_CONFIG_MALLOC.
594         **
595         ** Setting sqlite3GlobalConfig.m to all zeros will cause malloc to
596         ** revert to its default implementation when sqlite3_initialize() is run
597         */
598         memset(&sqlite3GlobalConfig.m, 0, sizeof(sqlite3GlobalConfig.m));
599       }else{
600         /* EVIDENCE-OF: R-61006-08918 If the memory pointer is not NULL then the
601         ** alternative memory allocator is engaged to handle all of SQLites
602         ** memory allocation needs. */
603 #ifdef SQLITE_ENABLE_MEMSYS3
604         sqlite3GlobalConfig.m = *sqlite3MemGetMemsys3();
605 #endif
606 #ifdef SQLITE_ENABLE_MEMSYS5
607         sqlite3GlobalConfig.m = *sqlite3MemGetMemsys5();
608 #endif
609       }
610       break;
611     }
612 #endif
613 
614     case SQLITE_CONFIG_LOOKASIDE: {
615       sqlite3GlobalConfig.szLookaside = va_arg(ap, int);
616       sqlite3GlobalConfig.nLookaside = va_arg(ap, int);
617       break;
618     }
619 
620     /* Record a pointer to the logger function and its first argument.
621     ** The default is NULL.  Logging is disabled if the function pointer is
622     ** NULL.
623     */
624     case SQLITE_CONFIG_LOG: {
625       /* MSVC is picky about pulling func ptrs from va lists.
626       ** http://support.microsoft.com/kb/47961
627       ** sqlite3GlobalConfig.xLog = va_arg(ap, void(*)(void*,int,const char*));
628       */
629       typedef void(*LOGFUNC_t)(void*,int,const char*);
630       sqlite3GlobalConfig.xLog = va_arg(ap, LOGFUNC_t);
631       sqlite3GlobalConfig.pLogArg = va_arg(ap, void*);
632       break;
633     }
634 
635     /* EVIDENCE-OF: R-55548-33817 The compile-time setting for URI filenames
636     ** can be changed at start-time using the
637     ** sqlite3_config(SQLITE_CONFIG_URI,1) or
638     ** sqlite3_config(SQLITE_CONFIG_URI,0) configuration calls.
639     */
640     case SQLITE_CONFIG_URI: {
641       /* EVIDENCE-OF: R-25451-61125 The SQLITE_CONFIG_URI option takes a single
642       ** argument of type int. If non-zero, then URI handling is globally
643       ** enabled. If the parameter is zero, then URI handling is globally
644       ** disabled. */
645       sqlite3GlobalConfig.bOpenUri = va_arg(ap, int);
646       break;
647     }
648 
649     case SQLITE_CONFIG_COVERING_INDEX_SCAN: {
650       /* EVIDENCE-OF: R-36592-02772 The SQLITE_CONFIG_COVERING_INDEX_SCAN
651       ** option takes a single integer argument which is interpreted as a
652       ** boolean in order to enable or disable the use of covering indices for
653       ** full table scans in the query optimizer. */
654       sqlite3GlobalConfig.bUseCis = va_arg(ap, int);
655       break;
656     }
657 
658 #ifdef SQLITE_ENABLE_SQLLOG
659     case SQLITE_CONFIG_SQLLOG: {
660       typedef void(*SQLLOGFUNC_t)(void*, sqlite3*, const char*, int);
661       sqlite3GlobalConfig.xSqllog = va_arg(ap, SQLLOGFUNC_t);
662       sqlite3GlobalConfig.pSqllogArg = va_arg(ap, void *);
663       break;
664     }
665 #endif
666 
667     case SQLITE_CONFIG_MMAP_SIZE: {
668       /* EVIDENCE-OF: R-58063-38258 SQLITE_CONFIG_MMAP_SIZE takes two 64-bit
669       ** integer (sqlite3_int64) values that are the default mmap size limit
670       ** (the default setting for PRAGMA mmap_size) and the maximum allowed
671       ** mmap size limit. */
672       sqlite3_int64 szMmap = va_arg(ap, sqlite3_int64);
673       sqlite3_int64 mxMmap = va_arg(ap, sqlite3_int64);
674       /* EVIDENCE-OF: R-53367-43190 If either argument to this option is
675       ** negative, then that argument is changed to its compile-time default.
676       **
677       ** EVIDENCE-OF: R-34993-45031 The maximum allowed mmap size will be
678       ** silently truncated if necessary so that it does not exceed the
679       ** compile-time maximum mmap size set by the SQLITE_MAX_MMAP_SIZE
680       ** compile-time option.
681       */
682       if( mxMmap<0 || mxMmap>SQLITE_MAX_MMAP_SIZE ){
683         mxMmap = SQLITE_MAX_MMAP_SIZE;
684       }
685       if( szMmap<0 ) szMmap = SQLITE_DEFAULT_MMAP_SIZE;
686       if( szMmap>mxMmap) szMmap = mxMmap;
687       sqlite3GlobalConfig.mxMmap = mxMmap;
688       sqlite3GlobalConfig.szMmap = szMmap;
689       break;
690     }
691 
692 #if SQLITE_OS_WIN && defined(SQLITE_WIN32_MALLOC) /* IMP: R-04780-55815 */
693     case SQLITE_CONFIG_WIN32_HEAPSIZE: {
694       /* EVIDENCE-OF: R-34926-03360 SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit
695       ** unsigned integer value that specifies the maximum size of the created
696       ** heap. */
697       sqlite3GlobalConfig.nHeap = va_arg(ap, int);
698       break;
699     }
700 #endif
701 
702     case SQLITE_CONFIG_PMASZ: {
703       sqlite3GlobalConfig.szPma = va_arg(ap, unsigned int);
704       break;
705     }
706 
707     case SQLITE_CONFIG_STMTJRNL_SPILL: {
708       sqlite3GlobalConfig.nStmtSpill = va_arg(ap, int);
709       break;
710     }
711 
712 #ifdef SQLITE_ENABLE_SORTER_REFERENCES
713     case SQLITE_CONFIG_SORTERREF_SIZE: {
714       int iVal = va_arg(ap, int);
715       if( iVal<0 ){
716         iVal = SQLITE_DEFAULT_SORTERREF_SIZE;
717       }
718       sqlite3GlobalConfig.szSorterRef = (u32)iVal;
719       break;
720     }
721 #endif /* SQLITE_ENABLE_SORTER_REFERENCES */
722 
723 #ifdef SQLITE_ENABLE_DESERIALIZE
724     case SQLITE_CONFIG_MEMDB_MAXSIZE: {
725       sqlite3GlobalConfig.mxMemdbSize = va_arg(ap, sqlite3_int64);
726       break;
727     }
728 #endif /* SQLITE_ENABLE_DESERIALIZE */
729 
730     default: {
731       rc = SQLITE_ERROR;
732       break;
733     }
734   }
735   va_end(ap);
736   return rc;
737 }
738 
739 /*
740 ** Set up the lookaside buffers for a database connection.
741 ** Return SQLITE_OK on success.
742 ** If lookaside is already active, return SQLITE_BUSY.
743 **
744 ** The sz parameter is the number of bytes in each lookaside slot.
745 ** The cnt parameter is the number of slots.  If pStart is NULL the
746 ** space for the lookaside memory is obtained from sqlite3_malloc().
747 ** If pStart is not NULL then it is sz*cnt bytes of memory to use for
748 ** the lookaside memory.
749 */
750 static int setupLookaside(sqlite3 *db, void *pBuf, int sz, int cnt){
751 #ifndef SQLITE_OMIT_LOOKASIDE
752   void *pStart;
753   sqlite3_int64 szAlloc = sz*(sqlite3_int64)cnt;
754   int nBig;   /* Number of full-size slots */
755   int nSm;    /* Number smaller LOOKASIDE_SMALL-byte slots */
756 
757   if( sqlite3LookasideUsed(db,0)>0 ){
758     return SQLITE_BUSY;
759   }
760   /* Free any existing lookaside buffer for this handle before
761   ** allocating a new one so we don't have to have space for
762   ** both at the same time.
763   */
764   if( db->lookaside.bMalloced ){
765     sqlite3_free(db->lookaside.pStart);
766   }
767   /* The size of a lookaside slot after ROUNDDOWN8 needs to be larger
768   ** than a pointer to be useful.
769   */
770   sz = ROUNDDOWN8(sz);  /* IMP: R-33038-09382 */
771   if( sz<=(int)sizeof(LookasideSlot*) ) sz = 0;
772   if( cnt<0 ) cnt = 0;
773   if( sz==0 || cnt==0 ){
774     sz = 0;
775     pStart = 0;
776   }else if( pBuf==0 ){
777     sqlite3BeginBenignMalloc();
778     pStart = sqlite3Malloc( szAlloc );  /* IMP: R-61949-35727 */
779     sqlite3EndBenignMalloc();
780     if( pStart ) szAlloc = sqlite3MallocSize(pStart);
781   }else{
782     pStart = pBuf;
783   }
784 #ifndef SQLITE_OMIT_TWOSIZE_LOOKASIDE
785   if( sz>=LOOKASIDE_SMALL*3 ){
786     nBig = szAlloc/(3*LOOKASIDE_SMALL+sz);
787     nSm = (szAlloc - sz*nBig)/LOOKASIDE_SMALL;
788   }else if( sz>=LOOKASIDE_SMALL*2 ){
789     nBig = szAlloc/(LOOKASIDE_SMALL+sz);
790     nSm = (szAlloc - sz*nBig)/LOOKASIDE_SMALL;
791   }else
792 #endif /* SQLITE_OMIT_TWOSIZE_LOOKASIDE */
793   if( sz>0 ){
794     nBig = szAlloc/sz;
795     nSm = 0;
796   }else{
797     nBig = nSm = 0;
798   }
799   db->lookaside.pStart = pStart;
800   db->lookaside.pInit = 0;
801   db->lookaside.pFree = 0;
802   db->lookaside.sz = (u16)sz;
803   db->lookaside.szTrue = (u16)sz;
804   if( pStart ){
805     int i;
806     LookasideSlot *p;
807     assert( sz > (int)sizeof(LookasideSlot*) );
808     p = (LookasideSlot*)pStart;
809     for(i=0; i<nBig; i++){
810       p->pNext = db->lookaside.pInit;
811       db->lookaside.pInit = p;
812       p = (LookasideSlot*)&((u8*)p)[sz];
813     }
814 #ifndef SQLITE_OMIT_TWOSIZE_LOOKASIDE
815     db->lookaside.pSmallInit = 0;
816     db->lookaside.pSmallFree = 0;
817     db->lookaside.pMiddle = p;
818     for(i=0; i<nSm; i++){
819       p->pNext = db->lookaside.pSmallInit;
820       db->lookaside.pSmallInit = p;
821       p = (LookasideSlot*)&((u8*)p)[LOOKASIDE_SMALL];
822     }
823 #endif /* SQLITE_OMIT_TWOSIZE_LOOKASIDE */
824     assert( ((uptr)p)<=szAlloc + (uptr)pStart );
825     db->lookaside.pEnd = p;
826     db->lookaside.bDisable = 0;
827     db->lookaside.bMalloced = pBuf==0 ?1:0;
828     db->lookaside.nSlot = nBig+nSm;
829   }else{
830     db->lookaside.pStart = db;
831 #ifndef SQLITE_OMIT_TWOSIZE_LOOKASIDE
832     db->lookaside.pSmallInit = 0;
833     db->lookaside.pSmallFree = 0;
834     db->lookaside.pMiddle = db;
835 #endif /* SQLITE_OMIT_TWOSIZE_LOOKASIDE */
836     db->lookaside.pEnd = db;
837     db->lookaside.bDisable = 1;
838     db->lookaside.sz = 0;
839     db->lookaside.bMalloced = 0;
840     db->lookaside.nSlot = 0;
841   }
842   assert( sqlite3LookasideUsed(db,0)==0 );
843 #endif /* SQLITE_OMIT_LOOKASIDE */
844   return SQLITE_OK;
845 }
846 
847 /*
848 ** Return the mutex associated with a database connection.
849 */
850 sqlite3_mutex *sqlite3_db_mutex(sqlite3 *db){
851 #ifdef SQLITE_ENABLE_API_ARMOR
852   if( !sqlite3SafetyCheckOk(db) ){
853     (void)SQLITE_MISUSE_BKPT;
854     return 0;
855   }
856 #endif
857   return db->mutex;
858 }
859 
860 /*
861 ** Free up as much memory as we can from the given database
862 ** connection.
863 */
864 int sqlite3_db_release_memory(sqlite3 *db){
865   int i;
866 
867 #ifdef SQLITE_ENABLE_API_ARMOR
868   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
869 #endif
870   sqlite3_mutex_enter(db->mutex);
871   sqlite3BtreeEnterAll(db);
872   for(i=0; i<db->nDb; i++){
873     Btree *pBt = db->aDb[i].pBt;
874     if( pBt ){
875       Pager *pPager = sqlite3BtreePager(pBt);
876       sqlite3PagerShrink(pPager);
877     }
878   }
879   sqlite3BtreeLeaveAll(db);
880   sqlite3_mutex_leave(db->mutex);
881   return SQLITE_OK;
882 }
883 
884 /*
885 ** Flush any dirty pages in the pager-cache for any attached database
886 ** to disk.
887 */
888 int sqlite3_db_cacheflush(sqlite3 *db){
889   int i;
890   int rc = SQLITE_OK;
891   int bSeenBusy = 0;
892 
893 #ifdef SQLITE_ENABLE_API_ARMOR
894   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
895 #endif
896   sqlite3_mutex_enter(db->mutex);
897   sqlite3BtreeEnterAll(db);
898   for(i=0; rc==SQLITE_OK && i<db->nDb; i++){
899     Btree *pBt = db->aDb[i].pBt;
900     if( pBt && sqlite3BtreeIsInTrans(pBt) ){
901       Pager *pPager = sqlite3BtreePager(pBt);
902       rc = sqlite3PagerFlush(pPager);
903       if( rc==SQLITE_BUSY ){
904         bSeenBusy = 1;
905         rc = SQLITE_OK;
906       }
907     }
908   }
909   sqlite3BtreeLeaveAll(db);
910   sqlite3_mutex_leave(db->mutex);
911   return ((rc==SQLITE_OK && bSeenBusy) ? SQLITE_BUSY : rc);
912 }
913 
914 /*
915 ** Configuration settings for an individual database connection
916 */
917 int sqlite3_db_config(sqlite3 *db, int op, ...){
918   va_list ap;
919   int rc;
920   va_start(ap, op);
921   switch( op ){
922     case SQLITE_DBCONFIG_MAINDBNAME: {
923       /* IMP: R-06824-28531 */
924       /* IMP: R-36257-52125 */
925       db->aDb[0].zDbSName = va_arg(ap,char*);
926       rc = SQLITE_OK;
927       break;
928     }
929     case SQLITE_DBCONFIG_LOOKASIDE: {
930       void *pBuf = va_arg(ap, void*); /* IMP: R-26835-10964 */
931       int sz = va_arg(ap, int);       /* IMP: R-47871-25994 */
932       int cnt = va_arg(ap, int);      /* IMP: R-04460-53386 */
933       rc = setupLookaside(db, pBuf, sz, cnt);
934       break;
935     }
936     default: {
937       static const struct {
938         int op;      /* The opcode */
939         u32 mask;    /* Mask of the bit in sqlite3.flags to set/clear */
940       } aFlagOp[] = {
941         { SQLITE_DBCONFIG_ENABLE_FKEY,           SQLITE_ForeignKeys    },
942         { SQLITE_DBCONFIG_ENABLE_TRIGGER,        SQLITE_EnableTrigger  },
943         { SQLITE_DBCONFIG_ENABLE_VIEW,           SQLITE_EnableView     },
944         { SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER, SQLITE_Fts3Tokenizer  },
945         { SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION, SQLITE_LoadExtension  },
946         { SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE,      SQLITE_NoCkptOnClose  },
947         { SQLITE_DBCONFIG_ENABLE_QPSG,           SQLITE_EnableQPSG     },
948         { SQLITE_DBCONFIG_TRIGGER_EQP,           SQLITE_TriggerEQP     },
949         { SQLITE_DBCONFIG_RESET_DATABASE,        SQLITE_ResetDatabase  },
950         { SQLITE_DBCONFIG_DEFENSIVE,             SQLITE_Defensive      },
951         { SQLITE_DBCONFIG_WRITABLE_SCHEMA,       SQLITE_WriteSchema|
952                                                  SQLITE_NoSchemaError  },
953         { SQLITE_DBCONFIG_LEGACY_ALTER_TABLE,    SQLITE_LegacyAlter    },
954         { SQLITE_DBCONFIG_DQS_DDL,               SQLITE_DqsDDL         },
955         { SQLITE_DBCONFIG_DQS_DML,               SQLITE_DqsDML         },
956         { SQLITE_DBCONFIG_LEGACY_FILE_FORMAT,    SQLITE_LegacyFileFmt  },
957         { SQLITE_DBCONFIG_TRUSTED_SCHEMA,        SQLITE_TrustedSchema  },
958       };
959       unsigned int i;
960       rc = SQLITE_ERROR; /* IMP: R-42790-23372 */
961       for(i=0; i<ArraySize(aFlagOp); i++){
962         if( aFlagOp[i].op==op ){
963           int onoff = va_arg(ap, int);
964           int *pRes = va_arg(ap, int*);
965           u64 oldFlags = db->flags;
966           if( onoff>0 ){
967             db->flags |= aFlagOp[i].mask;
968           }else if( onoff==0 ){
969             db->flags &= ~(u64)aFlagOp[i].mask;
970           }
971           if( oldFlags!=db->flags ){
972             sqlite3ExpirePreparedStatements(db, 0);
973           }
974           if( pRes ){
975             *pRes = (db->flags & aFlagOp[i].mask)!=0;
976           }
977           rc = SQLITE_OK;
978           break;
979         }
980       }
981       break;
982     }
983   }
984   va_end(ap);
985   return rc;
986 }
987 
988 /*
989 ** This is the default collating function named "BINARY" which is always
990 ** available.
991 */
992 static int binCollFunc(
993   void *NotUsed,
994   int nKey1, const void *pKey1,
995   int nKey2, const void *pKey2
996 ){
997   int rc, n;
998   UNUSED_PARAMETER(NotUsed);
999   n = nKey1<nKey2 ? nKey1 : nKey2;
1000   /* EVIDENCE-OF: R-65033-28449 The built-in BINARY collation compares
1001   ** strings byte by byte using the memcmp() function from the standard C
1002   ** library. */
1003   assert( pKey1 && pKey2 );
1004   rc = memcmp(pKey1, pKey2, n);
1005   if( rc==0 ){
1006     rc = nKey1 - nKey2;
1007   }
1008   return rc;
1009 }
1010 
1011 /*
1012 ** This is the collating function named "RTRIM" which is always
1013 ** available.  Ignore trailing spaces.
1014 */
1015 static int rtrimCollFunc(
1016   void *pUser,
1017   int nKey1, const void *pKey1,
1018   int nKey2, const void *pKey2
1019 ){
1020   const u8 *pK1 = (const u8*)pKey1;
1021   const u8 *pK2 = (const u8*)pKey2;
1022   while( nKey1 && pK1[nKey1-1]==' ' ) nKey1--;
1023   while( nKey2 && pK2[nKey2-1]==' ' ) nKey2--;
1024   return binCollFunc(pUser, nKey1, pKey1, nKey2, pKey2);
1025 }
1026 
1027 /*
1028 ** Return true if CollSeq is the default built-in BINARY.
1029 */
1030 int sqlite3IsBinary(const CollSeq *p){
1031   assert( p==0 || p->xCmp!=binCollFunc || strcmp(p->zName,"BINARY")==0 );
1032   return p==0 || p->xCmp==binCollFunc;
1033 }
1034 
1035 /*
1036 ** Another built-in collating sequence: NOCASE.
1037 **
1038 ** This collating sequence is intended to be used for "case independent
1039 ** comparison". SQLite's knowledge of upper and lower case equivalents
1040 ** extends only to the 26 characters used in the English language.
1041 **
1042 ** At the moment there is only a UTF-8 implementation.
1043 */
1044 static int nocaseCollatingFunc(
1045   void *NotUsed,
1046   int nKey1, const void *pKey1,
1047   int nKey2, const void *pKey2
1048 ){
1049   int r = sqlite3StrNICmp(
1050       (const char *)pKey1, (const char *)pKey2, (nKey1<nKey2)?nKey1:nKey2);
1051   UNUSED_PARAMETER(NotUsed);
1052   if( 0==r ){
1053     r = nKey1-nKey2;
1054   }
1055   return r;
1056 }
1057 
1058 /*
1059 ** Return the ROWID of the most recent insert
1060 */
1061 sqlite_int64 sqlite3_last_insert_rowid(sqlite3 *db){
1062 #ifdef SQLITE_ENABLE_API_ARMOR
1063   if( !sqlite3SafetyCheckOk(db) ){
1064     (void)SQLITE_MISUSE_BKPT;
1065     return 0;
1066   }
1067 #endif
1068   return db->lastRowid;
1069 }
1070 
1071 /*
1072 ** Set the value returned by the sqlite3_last_insert_rowid() API function.
1073 */
1074 void sqlite3_set_last_insert_rowid(sqlite3 *db, sqlite3_int64 iRowid){
1075 #ifdef SQLITE_ENABLE_API_ARMOR
1076   if( !sqlite3SafetyCheckOk(db) ){
1077     (void)SQLITE_MISUSE_BKPT;
1078     return;
1079   }
1080 #endif
1081   sqlite3_mutex_enter(db->mutex);
1082   db->lastRowid = iRowid;
1083   sqlite3_mutex_leave(db->mutex);
1084 }
1085 
1086 /*
1087 ** Return the number of changes in the most recent call to sqlite3_exec().
1088 */
1089 int sqlite3_changes(sqlite3 *db){
1090 #ifdef SQLITE_ENABLE_API_ARMOR
1091   if( !sqlite3SafetyCheckOk(db) ){
1092     (void)SQLITE_MISUSE_BKPT;
1093     return 0;
1094   }
1095 #endif
1096   return db->nChange;
1097 }
1098 
1099 /*
1100 ** Return the number of changes since the database handle was opened.
1101 */
1102 int sqlite3_total_changes(sqlite3 *db){
1103 #ifdef SQLITE_ENABLE_API_ARMOR
1104   if( !sqlite3SafetyCheckOk(db) ){
1105     (void)SQLITE_MISUSE_BKPT;
1106     return 0;
1107   }
1108 #endif
1109   return db->nTotalChange;
1110 }
1111 
1112 /*
1113 ** Close all open savepoints. This function only manipulates fields of the
1114 ** database handle object, it does not close any savepoints that may be open
1115 ** at the b-tree/pager level.
1116 */
1117 void sqlite3CloseSavepoints(sqlite3 *db){
1118   while( db->pSavepoint ){
1119     Savepoint *pTmp = db->pSavepoint;
1120     db->pSavepoint = pTmp->pNext;
1121     sqlite3DbFree(db, pTmp);
1122   }
1123   db->nSavepoint = 0;
1124   db->nStatement = 0;
1125   db->isTransactionSavepoint = 0;
1126 }
1127 
1128 /*
1129 ** Invoke the destructor function associated with FuncDef p, if any. Except,
1130 ** if this is not the last copy of the function, do not invoke it. Multiple
1131 ** copies of a single function are created when create_function() is called
1132 ** with SQLITE_ANY as the encoding.
1133 */
1134 static void functionDestroy(sqlite3 *db, FuncDef *p){
1135   FuncDestructor *pDestructor = p->u.pDestructor;
1136   if( pDestructor ){
1137     pDestructor->nRef--;
1138     if( pDestructor->nRef==0 ){
1139       pDestructor->xDestroy(pDestructor->pUserData);
1140       sqlite3DbFree(db, pDestructor);
1141     }
1142   }
1143 }
1144 
1145 /*
1146 ** Disconnect all sqlite3_vtab objects that belong to database connection
1147 ** db. This is called when db is being closed.
1148 */
1149 static void disconnectAllVtab(sqlite3 *db){
1150 #ifndef SQLITE_OMIT_VIRTUALTABLE
1151   int i;
1152   HashElem *p;
1153   sqlite3BtreeEnterAll(db);
1154   for(i=0; i<db->nDb; i++){
1155     Schema *pSchema = db->aDb[i].pSchema;
1156     if( pSchema ){
1157       for(p=sqliteHashFirst(&pSchema->tblHash); p; p=sqliteHashNext(p)){
1158         Table *pTab = (Table *)sqliteHashData(p);
1159         if( IsVirtual(pTab) ) sqlite3VtabDisconnect(db, pTab);
1160       }
1161     }
1162   }
1163   for(p=sqliteHashFirst(&db->aModule); p; p=sqliteHashNext(p)){
1164     Module *pMod = (Module *)sqliteHashData(p);
1165     if( pMod->pEpoTab ){
1166       sqlite3VtabDisconnect(db, pMod->pEpoTab);
1167     }
1168   }
1169   sqlite3VtabUnlockList(db);
1170   sqlite3BtreeLeaveAll(db);
1171 #else
1172   UNUSED_PARAMETER(db);
1173 #endif
1174 }
1175 
1176 /*
1177 ** Return TRUE if database connection db has unfinalized prepared
1178 ** statements or unfinished sqlite3_backup objects.
1179 */
1180 static int connectionIsBusy(sqlite3 *db){
1181   int j;
1182   assert( sqlite3_mutex_held(db->mutex) );
1183   if( db->pVdbe ) return 1;
1184   for(j=0; j<db->nDb; j++){
1185     Btree *pBt = db->aDb[j].pBt;
1186     if( pBt && sqlite3BtreeIsInBackup(pBt) ) return 1;
1187   }
1188   return 0;
1189 }
1190 
1191 /*
1192 ** Close an existing SQLite database
1193 */
1194 static int sqlite3Close(sqlite3 *db, int forceZombie){
1195   if( !db ){
1196     /* EVIDENCE-OF: R-63257-11740 Calling sqlite3_close() or
1197     ** sqlite3_close_v2() with a NULL pointer argument is a harmless no-op. */
1198     return SQLITE_OK;
1199   }
1200   if( !sqlite3SafetyCheckSickOrOk(db) ){
1201     return SQLITE_MISUSE_BKPT;
1202   }
1203   sqlite3_mutex_enter(db->mutex);
1204   if( db->mTrace & SQLITE_TRACE_CLOSE ){
1205     db->xTrace(SQLITE_TRACE_CLOSE, db->pTraceArg, db, 0);
1206   }
1207 
1208   /* Force xDisconnect calls on all virtual tables */
1209   disconnectAllVtab(db);
1210 
1211   /* If a transaction is open, the disconnectAllVtab() call above
1212   ** will not have called the xDisconnect() method on any virtual
1213   ** tables in the db->aVTrans[] array. The following sqlite3VtabRollback()
1214   ** call will do so. We need to do this before the check for active
1215   ** SQL statements below, as the v-table implementation may be storing
1216   ** some prepared statements internally.
1217   */
1218   sqlite3VtabRollback(db);
1219 
1220   /* Legacy behavior (sqlite3_close() behavior) is to return
1221   ** SQLITE_BUSY if the connection can not be closed immediately.
1222   */
1223   if( !forceZombie && connectionIsBusy(db) ){
1224     sqlite3ErrorWithMsg(db, SQLITE_BUSY, "unable to close due to unfinalized "
1225        "statements or unfinished backups");
1226     sqlite3_mutex_leave(db->mutex);
1227     return SQLITE_BUSY;
1228   }
1229 
1230 #ifdef SQLITE_ENABLE_SQLLOG
1231   if( sqlite3GlobalConfig.xSqllog ){
1232     /* Closing the handle. Fourth parameter is passed the value 2. */
1233     sqlite3GlobalConfig.xSqllog(sqlite3GlobalConfig.pSqllogArg, db, 0, 2);
1234   }
1235 #endif
1236 
1237   /* Convert the connection into a zombie and then close it.
1238   */
1239   db->magic = SQLITE_MAGIC_ZOMBIE;
1240   sqlite3LeaveMutexAndCloseZombie(db);
1241   return SQLITE_OK;
1242 }
1243 
1244 /*
1245 ** Two variations on the public interface for closing a database
1246 ** connection. The sqlite3_close() version returns SQLITE_BUSY and
1247 ** leaves the connection option if there are unfinalized prepared
1248 ** statements or unfinished sqlite3_backups.  The sqlite3_close_v2()
1249 ** version forces the connection to become a zombie if there are
1250 ** unclosed resources, and arranges for deallocation when the last
1251 ** prepare statement or sqlite3_backup closes.
1252 */
1253 int sqlite3_close(sqlite3 *db){ return sqlite3Close(db,0); }
1254 int sqlite3_close_v2(sqlite3 *db){ return sqlite3Close(db,1); }
1255 
1256 
1257 /*
1258 ** Close the mutex on database connection db.
1259 **
1260 ** Furthermore, if database connection db is a zombie (meaning that there
1261 ** has been a prior call to sqlite3_close(db) or sqlite3_close_v2(db)) and
1262 ** every sqlite3_stmt has now been finalized and every sqlite3_backup has
1263 ** finished, then free all resources.
1264 */
1265 void sqlite3LeaveMutexAndCloseZombie(sqlite3 *db){
1266   HashElem *i;                    /* Hash table iterator */
1267   int j;
1268 
1269   /* If there are outstanding sqlite3_stmt or sqlite3_backup objects
1270   ** or if the connection has not yet been closed by sqlite3_close_v2(),
1271   ** then just leave the mutex and return.
1272   */
1273   if( db->magic!=SQLITE_MAGIC_ZOMBIE || connectionIsBusy(db) ){
1274     sqlite3_mutex_leave(db->mutex);
1275     return;
1276   }
1277 
1278   /* If we reach this point, it means that the database connection has
1279   ** closed all sqlite3_stmt and sqlite3_backup objects and has been
1280   ** passed to sqlite3_close (meaning that it is a zombie).  Therefore,
1281   ** go ahead and free all resources.
1282   */
1283 
1284   /* If a transaction is open, roll it back. This also ensures that if
1285   ** any database schemas have been modified by an uncommitted transaction
1286   ** they are reset. And that the required b-tree mutex is held to make
1287   ** the pager rollback and schema reset an atomic operation. */
1288   sqlite3RollbackAll(db, SQLITE_OK);
1289 
1290   /* Free any outstanding Savepoint structures. */
1291   sqlite3CloseSavepoints(db);
1292 
1293   /* Close all database connections */
1294   for(j=0; j<db->nDb; j++){
1295     struct Db *pDb = &db->aDb[j];
1296     if( pDb->pBt ){
1297       sqlite3BtreeClose(pDb->pBt);
1298       pDb->pBt = 0;
1299       if( j!=1 ){
1300         pDb->pSchema = 0;
1301       }
1302     }
1303   }
1304   /* Clear the TEMP schema separately and last */
1305   if( db->aDb[1].pSchema ){
1306     sqlite3SchemaClear(db->aDb[1].pSchema);
1307   }
1308   sqlite3VtabUnlockList(db);
1309 
1310   /* Free up the array of auxiliary databases */
1311   sqlite3CollapseDatabaseArray(db);
1312   assert( db->nDb<=2 );
1313   assert( db->aDb==db->aDbStatic );
1314 
1315   /* Tell the code in notify.c that the connection no longer holds any
1316   ** locks and does not require any further unlock-notify callbacks.
1317   */
1318   sqlite3ConnectionClosed(db);
1319 
1320   for(i=sqliteHashFirst(&db->aFunc); i; i=sqliteHashNext(i)){
1321     FuncDef *pNext, *p;
1322     p = sqliteHashData(i);
1323     do{
1324       functionDestroy(db, p);
1325       pNext = p->pNext;
1326       sqlite3DbFree(db, p);
1327       p = pNext;
1328     }while( p );
1329   }
1330   sqlite3HashClear(&db->aFunc);
1331   for(i=sqliteHashFirst(&db->aCollSeq); i; i=sqliteHashNext(i)){
1332     CollSeq *pColl = (CollSeq *)sqliteHashData(i);
1333     /* Invoke any destructors registered for collation sequence user data. */
1334     for(j=0; j<3; j++){
1335       if( pColl[j].xDel ){
1336         pColl[j].xDel(pColl[j].pUser);
1337       }
1338     }
1339     sqlite3DbFree(db, pColl);
1340   }
1341   sqlite3HashClear(&db->aCollSeq);
1342 #ifndef SQLITE_OMIT_VIRTUALTABLE
1343   for(i=sqliteHashFirst(&db->aModule); i; i=sqliteHashNext(i)){
1344     Module *pMod = (Module *)sqliteHashData(i);
1345     sqlite3VtabEponymousTableClear(db, pMod);
1346     sqlite3VtabModuleUnref(db, pMod);
1347   }
1348   sqlite3HashClear(&db->aModule);
1349 #endif
1350 
1351   sqlite3Error(db, SQLITE_OK); /* Deallocates any cached error strings. */
1352   sqlite3ValueFree(db->pErr);
1353   sqlite3CloseExtensions(db);
1354 #if SQLITE_USER_AUTHENTICATION
1355   sqlite3_free(db->auth.zAuthUser);
1356   sqlite3_free(db->auth.zAuthPW);
1357 #endif
1358 
1359   db->magic = SQLITE_MAGIC_ERROR;
1360 
1361   /* The temp-database schema is allocated differently from the other schema
1362   ** objects (using sqliteMalloc() directly, instead of sqlite3BtreeSchema()).
1363   ** So it needs to be freed here. Todo: Why not roll the temp schema into
1364   ** the same sqliteMalloc() as the one that allocates the database
1365   ** structure?
1366   */
1367   sqlite3DbFree(db, db->aDb[1].pSchema);
1368   sqlite3_mutex_leave(db->mutex);
1369   db->magic = SQLITE_MAGIC_CLOSED;
1370   sqlite3_mutex_free(db->mutex);
1371   assert( sqlite3LookasideUsed(db,0)==0 );
1372   if( db->lookaside.bMalloced ){
1373     sqlite3_free(db->lookaside.pStart);
1374   }
1375   sqlite3_free(db);
1376 }
1377 
1378 /*
1379 ** Rollback all database files.  If tripCode is not SQLITE_OK, then
1380 ** any write cursors are invalidated ("tripped" - as in "tripping a circuit
1381 ** breaker") and made to return tripCode if there are any further
1382 ** attempts to use that cursor.  Read cursors remain open and valid
1383 ** but are "saved" in case the table pages are moved around.
1384 */
1385 void sqlite3RollbackAll(sqlite3 *db, int tripCode){
1386   int i;
1387   int inTrans = 0;
1388   int schemaChange;
1389   assert( sqlite3_mutex_held(db->mutex) );
1390   sqlite3BeginBenignMalloc();
1391 
1392   /* Obtain all b-tree mutexes before making any calls to BtreeRollback().
1393   ** This is important in case the transaction being rolled back has
1394   ** modified the database schema. If the b-tree mutexes are not taken
1395   ** here, then another shared-cache connection might sneak in between
1396   ** the database rollback and schema reset, which can cause false
1397   ** corruption reports in some cases.  */
1398   sqlite3BtreeEnterAll(db);
1399   schemaChange = (db->mDbFlags & DBFLAG_SchemaChange)!=0 && db->init.busy==0;
1400 
1401   for(i=0; i<db->nDb; i++){
1402     Btree *p = db->aDb[i].pBt;
1403     if( p ){
1404       if( sqlite3BtreeIsInTrans(p) ){
1405         inTrans = 1;
1406       }
1407       sqlite3BtreeRollback(p, tripCode, !schemaChange);
1408     }
1409   }
1410   sqlite3VtabRollback(db);
1411   sqlite3EndBenignMalloc();
1412 
1413   if( schemaChange ){
1414     sqlite3ExpirePreparedStatements(db, 0);
1415     sqlite3ResetAllSchemasOfConnection(db);
1416   }
1417   sqlite3BtreeLeaveAll(db);
1418 
1419   /* Any deferred constraint violations have now been resolved. */
1420   db->nDeferredCons = 0;
1421   db->nDeferredImmCons = 0;
1422   db->flags &= ~(u64)SQLITE_DeferFKs;
1423 
1424   /* If one has been configured, invoke the rollback-hook callback */
1425   if( db->xRollbackCallback && (inTrans || !db->autoCommit) ){
1426     db->xRollbackCallback(db->pRollbackArg);
1427   }
1428 }
1429 
1430 /*
1431 ** Return a static string containing the name corresponding to the error code
1432 ** specified in the argument.
1433 */
1434 #if defined(SQLITE_NEED_ERR_NAME)
1435 const char *sqlite3ErrName(int rc){
1436   const char *zName = 0;
1437   int i, origRc = rc;
1438   for(i=0; i<2 && zName==0; i++, rc &= 0xff){
1439     switch( rc ){
1440       case SQLITE_OK:                 zName = "SQLITE_OK";                break;
1441       case SQLITE_ERROR:              zName = "SQLITE_ERROR";             break;
1442       case SQLITE_ERROR_SNAPSHOT:     zName = "SQLITE_ERROR_SNAPSHOT";    break;
1443       case SQLITE_INTERNAL:           zName = "SQLITE_INTERNAL";          break;
1444       case SQLITE_PERM:               zName = "SQLITE_PERM";              break;
1445       case SQLITE_ABORT:              zName = "SQLITE_ABORT";             break;
1446       case SQLITE_ABORT_ROLLBACK:     zName = "SQLITE_ABORT_ROLLBACK";    break;
1447       case SQLITE_BUSY:               zName = "SQLITE_BUSY";              break;
1448       case SQLITE_BUSY_RECOVERY:      zName = "SQLITE_BUSY_RECOVERY";     break;
1449       case SQLITE_BUSY_SNAPSHOT:      zName = "SQLITE_BUSY_SNAPSHOT";     break;
1450       case SQLITE_LOCKED:             zName = "SQLITE_LOCKED";            break;
1451       case SQLITE_LOCKED_SHAREDCACHE: zName = "SQLITE_LOCKED_SHAREDCACHE";break;
1452       case SQLITE_NOMEM:              zName = "SQLITE_NOMEM";             break;
1453       case SQLITE_READONLY:           zName = "SQLITE_READONLY";          break;
1454       case SQLITE_READONLY_RECOVERY:  zName = "SQLITE_READONLY_RECOVERY"; break;
1455       case SQLITE_READONLY_CANTINIT:  zName = "SQLITE_READONLY_CANTINIT"; break;
1456       case SQLITE_READONLY_ROLLBACK:  zName = "SQLITE_READONLY_ROLLBACK"; break;
1457       case SQLITE_READONLY_DBMOVED:   zName = "SQLITE_READONLY_DBMOVED";  break;
1458       case SQLITE_READONLY_DIRECTORY: zName = "SQLITE_READONLY_DIRECTORY";break;
1459       case SQLITE_INTERRUPT:          zName = "SQLITE_INTERRUPT";         break;
1460       case SQLITE_IOERR:              zName = "SQLITE_IOERR";             break;
1461       case SQLITE_IOERR_READ:         zName = "SQLITE_IOERR_READ";        break;
1462       case SQLITE_IOERR_SHORT_READ:   zName = "SQLITE_IOERR_SHORT_READ";  break;
1463       case SQLITE_IOERR_WRITE:        zName = "SQLITE_IOERR_WRITE";       break;
1464       case SQLITE_IOERR_FSYNC:        zName = "SQLITE_IOERR_FSYNC";       break;
1465       case SQLITE_IOERR_DIR_FSYNC:    zName = "SQLITE_IOERR_DIR_FSYNC";   break;
1466       case SQLITE_IOERR_TRUNCATE:     zName = "SQLITE_IOERR_TRUNCATE";    break;
1467       case SQLITE_IOERR_FSTAT:        zName = "SQLITE_IOERR_FSTAT";       break;
1468       case SQLITE_IOERR_UNLOCK:       zName = "SQLITE_IOERR_UNLOCK";      break;
1469       case SQLITE_IOERR_RDLOCK:       zName = "SQLITE_IOERR_RDLOCK";      break;
1470       case SQLITE_IOERR_DELETE:       zName = "SQLITE_IOERR_DELETE";      break;
1471       case SQLITE_IOERR_NOMEM:        zName = "SQLITE_IOERR_NOMEM";       break;
1472       case SQLITE_IOERR_ACCESS:       zName = "SQLITE_IOERR_ACCESS";      break;
1473       case SQLITE_IOERR_CHECKRESERVEDLOCK:
1474                                 zName = "SQLITE_IOERR_CHECKRESERVEDLOCK"; break;
1475       case SQLITE_IOERR_LOCK:         zName = "SQLITE_IOERR_LOCK";        break;
1476       case SQLITE_IOERR_CLOSE:        zName = "SQLITE_IOERR_CLOSE";       break;
1477       case SQLITE_IOERR_DIR_CLOSE:    zName = "SQLITE_IOERR_DIR_CLOSE";   break;
1478       case SQLITE_IOERR_SHMOPEN:      zName = "SQLITE_IOERR_SHMOPEN";     break;
1479       case SQLITE_IOERR_SHMSIZE:      zName = "SQLITE_IOERR_SHMSIZE";     break;
1480       case SQLITE_IOERR_SHMLOCK:      zName = "SQLITE_IOERR_SHMLOCK";     break;
1481       case SQLITE_IOERR_SHMMAP:       zName = "SQLITE_IOERR_SHMMAP";      break;
1482       case SQLITE_IOERR_SEEK:         zName = "SQLITE_IOERR_SEEK";        break;
1483       case SQLITE_IOERR_DELETE_NOENT: zName = "SQLITE_IOERR_DELETE_NOENT";break;
1484       case SQLITE_IOERR_MMAP:         zName = "SQLITE_IOERR_MMAP";        break;
1485       case SQLITE_IOERR_GETTEMPPATH:  zName = "SQLITE_IOERR_GETTEMPPATH"; break;
1486       case SQLITE_IOERR_CONVPATH:     zName = "SQLITE_IOERR_CONVPATH";    break;
1487       case SQLITE_CORRUPT:            zName = "SQLITE_CORRUPT";           break;
1488       case SQLITE_CORRUPT_VTAB:       zName = "SQLITE_CORRUPT_VTAB";      break;
1489       case SQLITE_NOTFOUND:           zName = "SQLITE_NOTFOUND";          break;
1490       case SQLITE_FULL:               zName = "SQLITE_FULL";              break;
1491       case SQLITE_CANTOPEN:           zName = "SQLITE_CANTOPEN";          break;
1492       case SQLITE_CANTOPEN_NOTEMPDIR: zName = "SQLITE_CANTOPEN_NOTEMPDIR";break;
1493       case SQLITE_CANTOPEN_ISDIR:     zName = "SQLITE_CANTOPEN_ISDIR";    break;
1494       case SQLITE_CANTOPEN_FULLPATH:  zName = "SQLITE_CANTOPEN_FULLPATH"; break;
1495       case SQLITE_CANTOPEN_CONVPATH:  zName = "SQLITE_CANTOPEN_CONVPATH"; break;
1496       case SQLITE_CANTOPEN_SYMLINK:   zName = "SQLITE_CANTOPEN_SYMLINK";  break;
1497       case SQLITE_PROTOCOL:           zName = "SQLITE_PROTOCOL";          break;
1498       case SQLITE_EMPTY:              zName = "SQLITE_EMPTY";             break;
1499       case SQLITE_SCHEMA:             zName = "SQLITE_SCHEMA";            break;
1500       case SQLITE_TOOBIG:             zName = "SQLITE_TOOBIG";            break;
1501       case SQLITE_CONSTRAINT:         zName = "SQLITE_CONSTRAINT";        break;
1502       case SQLITE_CONSTRAINT_UNIQUE:  zName = "SQLITE_CONSTRAINT_UNIQUE"; break;
1503       case SQLITE_CONSTRAINT_TRIGGER: zName = "SQLITE_CONSTRAINT_TRIGGER";break;
1504       case SQLITE_CONSTRAINT_FOREIGNKEY:
1505                                 zName = "SQLITE_CONSTRAINT_FOREIGNKEY";   break;
1506       case SQLITE_CONSTRAINT_CHECK:   zName = "SQLITE_CONSTRAINT_CHECK";  break;
1507       case SQLITE_CONSTRAINT_PRIMARYKEY:
1508                                 zName = "SQLITE_CONSTRAINT_PRIMARYKEY";   break;
1509       case SQLITE_CONSTRAINT_NOTNULL: zName = "SQLITE_CONSTRAINT_NOTNULL";break;
1510       case SQLITE_CONSTRAINT_COMMITHOOK:
1511                                 zName = "SQLITE_CONSTRAINT_COMMITHOOK";   break;
1512       case SQLITE_CONSTRAINT_VTAB:    zName = "SQLITE_CONSTRAINT_VTAB";   break;
1513       case SQLITE_CONSTRAINT_FUNCTION:
1514                                 zName = "SQLITE_CONSTRAINT_FUNCTION";     break;
1515       case SQLITE_CONSTRAINT_ROWID:   zName = "SQLITE_CONSTRAINT_ROWID";  break;
1516       case SQLITE_MISMATCH:           zName = "SQLITE_MISMATCH";          break;
1517       case SQLITE_MISUSE:             zName = "SQLITE_MISUSE";            break;
1518       case SQLITE_NOLFS:              zName = "SQLITE_NOLFS";             break;
1519       case SQLITE_AUTH:               zName = "SQLITE_AUTH";              break;
1520       case SQLITE_FORMAT:             zName = "SQLITE_FORMAT";            break;
1521       case SQLITE_RANGE:              zName = "SQLITE_RANGE";             break;
1522       case SQLITE_NOTADB:             zName = "SQLITE_NOTADB";            break;
1523       case SQLITE_ROW:                zName = "SQLITE_ROW";               break;
1524       case SQLITE_NOTICE:             zName = "SQLITE_NOTICE";            break;
1525       case SQLITE_NOTICE_RECOVER_WAL: zName = "SQLITE_NOTICE_RECOVER_WAL";break;
1526       case SQLITE_NOTICE_RECOVER_ROLLBACK:
1527                                 zName = "SQLITE_NOTICE_RECOVER_ROLLBACK"; break;
1528       case SQLITE_WARNING:            zName = "SQLITE_WARNING";           break;
1529       case SQLITE_WARNING_AUTOINDEX:  zName = "SQLITE_WARNING_AUTOINDEX"; break;
1530       case SQLITE_DONE:               zName = "SQLITE_DONE";              break;
1531     }
1532   }
1533   if( zName==0 ){
1534     static char zBuf[50];
1535     sqlite3_snprintf(sizeof(zBuf), zBuf, "SQLITE_UNKNOWN(%d)", origRc);
1536     zName = zBuf;
1537   }
1538   return zName;
1539 }
1540 #endif
1541 
1542 /*
1543 ** Return a static string that describes the kind of error specified in the
1544 ** argument.
1545 */
1546 const char *sqlite3ErrStr(int rc){
1547   static const char* const aMsg[] = {
1548     /* SQLITE_OK          */ "not an error",
1549     /* SQLITE_ERROR       */ "SQL logic error",
1550     /* SQLITE_INTERNAL    */ 0,
1551     /* SQLITE_PERM        */ "access permission denied",
1552     /* SQLITE_ABORT       */ "query aborted",
1553     /* SQLITE_BUSY        */ "database is locked",
1554     /* SQLITE_LOCKED      */ "database table is locked",
1555     /* SQLITE_NOMEM       */ "out of memory",
1556     /* SQLITE_READONLY    */ "attempt to write a readonly database",
1557     /* SQLITE_INTERRUPT   */ "interrupted",
1558     /* SQLITE_IOERR       */ "disk I/O error",
1559     /* SQLITE_CORRUPT     */ "database disk image is malformed",
1560     /* SQLITE_NOTFOUND    */ "unknown operation",
1561     /* SQLITE_FULL        */ "database or disk is full",
1562     /* SQLITE_CANTOPEN    */ "unable to open database file",
1563     /* SQLITE_PROTOCOL    */ "locking protocol",
1564     /* SQLITE_EMPTY       */ 0,
1565     /* SQLITE_SCHEMA      */ "database schema has changed",
1566     /* SQLITE_TOOBIG      */ "string or blob too big",
1567     /* SQLITE_CONSTRAINT  */ "constraint failed",
1568     /* SQLITE_MISMATCH    */ "datatype mismatch",
1569     /* SQLITE_MISUSE      */ "bad parameter or other API misuse",
1570 #ifdef SQLITE_DISABLE_LFS
1571     /* SQLITE_NOLFS       */ "large file support is disabled",
1572 #else
1573     /* SQLITE_NOLFS       */ 0,
1574 #endif
1575     /* SQLITE_AUTH        */ "authorization denied",
1576     /* SQLITE_FORMAT      */ 0,
1577     /* SQLITE_RANGE       */ "column index out of range",
1578     /* SQLITE_NOTADB      */ "file is not a database",
1579     /* SQLITE_NOTICE      */ "notification message",
1580     /* SQLITE_WARNING     */ "warning message",
1581   };
1582   const char *zErr = "unknown error";
1583   switch( rc ){
1584     case SQLITE_ABORT_ROLLBACK: {
1585       zErr = "abort due to ROLLBACK";
1586       break;
1587     }
1588     case SQLITE_ROW: {
1589       zErr = "another row available";
1590       break;
1591     }
1592     case SQLITE_DONE: {
1593       zErr = "no more rows available";
1594       break;
1595     }
1596     default: {
1597       rc &= 0xff;
1598       if( ALWAYS(rc>=0) && rc<ArraySize(aMsg) && aMsg[rc]!=0 ){
1599         zErr = aMsg[rc];
1600       }
1601       break;
1602     }
1603   }
1604   return zErr;
1605 }
1606 
1607 /*
1608 ** This routine implements a busy callback that sleeps and tries
1609 ** again until a timeout value is reached.  The timeout value is
1610 ** an integer number of milliseconds passed in as the first
1611 ** argument.
1612 **
1613 ** Return non-zero to retry the lock.  Return zero to stop trying
1614 ** and cause SQLite to return SQLITE_BUSY.
1615 */
1616 static int sqliteDefaultBusyCallback(
1617   void *ptr,               /* Database connection */
1618   int count                /* Number of times table has been busy */
1619 ){
1620 #if SQLITE_OS_WIN || HAVE_USLEEP
1621   /* This case is for systems that have support for sleeping for fractions of
1622   ** a second.  Examples:  All windows systems, unix systems with usleep() */
1623   static const u8 delays[] =
1624      { 1, 2, 5, 10, 15, 20, 25, 25,  25,  50,  50, 100 };
1625   static const u8 totals[] =
1626      { 0, 1, 3,  8, 18, 33, 53, 78, 103, 128, 178, 228 };
1627 # define NDELAY ArraySize(delays)
1628   sqlite3 *db = (sqlite3 *)ptr;
1629   int tmout = db->busyTimeout;
1630   int delay, prior;
1631 
1632   assert( count>=0 );
1633   if( count < NDELAY ){
1634     delay = delays[count];
1635     prior = totals[count];
1636   }else{
1637     delay = delays[NDELAY-1];
1638     prior = totals[NDELAY-1] + delay*(count-(NDELAY-1));
1639   }
1640   if( prior + delay > tmout ){
1641     delay = tmout - prior;
1642     if( delay<=0 ) return 0;
1643   }
1644   sqlite3OsSleep(db->pVfs, delay*1000);
1645   return 1;
1646 #else
1647   /* This case for unix systems that lack usleep() support.  Sleeping
1648   ** must be done in increments of whole seconds */
1649   sqlite3 *db = (sqlite3 *)ptr;
1650   int tmout = ((sqlite3 *)ptr)->busyTimeout;
1651   if( (count+1)*1000 > tmout ){
1652     return 0;
1653   }
1654   sqlite3OsSleep(db->pVfs, 1000000);
1655   return 1;
1656 #endif
1657 }
1658 
1659 /*
1660 ** Invoke the given busy handler.
1661 **
1662 ** This routine is called when an operation failed to acquire a
1663 ** lock on VFS file pFile.
1664 **
1665 ** If this routine returns non-zero, the lock is retried.  If it
1666 ** returns 0, the operation aborts with an SQLITE_BUSY error.
1667 */
1668 int sqlite3InvokeBusyHandler(BusyHandler *p){
1669   int rc;
1670   if( p->xBusyHandler==0 || p->nBusy<0 ) return 0;
1671   rc = p->xBusyHandler(p->pBusyArg, p->nBusy);
1672   if( rc==0 ){
1673     p->nBusy = -1;
1674   }else{
1675     p->nBusy++;
1676   }
1677   return rc;
1678 }
1679 
1680 /*
1681 ** This routine sets the busy callback for an Sqlite database to the
1682 ** given callback function with the given argument.
1683 */
1684 int sqlite3_busy_handler(
1685   sqlite3 *db,
1686   int (*xBusy)(void*,int),
1687   void *pArg
1688 ){
1689 #ifdef SQLITE_ENABLE_API_ARMOR
1690   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
1691 #endif
1692   sqlite3_mutex_enter(db->mutex);
1693   db->busyHandler.xBusyHandler = xBusy;
1694   db->busyHandler.pBusyArg = pArg;
1695   db->busyHandler.nBusy = 0;
1696   db->busyTimeout = 0;
1697   sqlite3_mutex_leave(db->mutex);
1698   return SQLITE_OK;
1699 }
1700 
1701 #ifndef SQLITE_OMIT_PROGRESS_CALLBACK
1702 /*
1703 ** This routine sets the progress callback for an Sqlite database to the
1704 ** given callback function with the given argument. The progress callback will
1705 ** be invoked every nOps opcodes.
1706 */
1707 void sqlite3_progress_handler(
1708   sqlite3 *db,
1709   int nOps,
1710   int (*xProgress)(void*),
1711   void *pArg
1712 ){
1713 #ifdef SQLITE_ENABLE_API_ARMOR
1714   if( !sqlite3SafetyCheckOk(db) ){
1715     (void)SQLITE_MISUSE_BKPT;
1716     return;
1717   }
1718 #endif
1719   sqlite3_mutex_enter(db->mutex);
1720   if( nOps>0 ){
1721     db->xProgress = xProgress;
1722     db->nProgressOps = (unsigned)nOps;
1723     db->pProgressArg = pArg;
1724   }else{
1725     db->xProgress = 0;
1726     db->nProgressOps = 0;
1727     db->pProgressArg = 0;
1728   }
1729   sqlite3_mutex_leave(db->mutex);
1730 }
1731 #endif
1732 
1733 
1734 /*
1735 ** This routine installs a default busy handler that waits for the
1736 ** specified number of milliseconds before returning 0.
1737 */
1738 int sqlite3_busy_timeout(sqlite3 *db, int ms){
1739 #ifdef SQLITE_ENABLE_API_ARMOR
1740   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
1741 #endif
1742   if( ms>0 ){
1743     sqlite3_busy_handler(db, (int(*)(void*,int))sqliteDefaultBusyCallback,
1744                              (void*)db);
1745     db->busyTimeout = ms;
1746   }else{
1747     sqlite3_busy_handler(db, 0, 0);
1748   }
1749   return SQLITE_OK;
1750 }
1751 
1752 /*
1753 ** Cause any pending operation to stop at its earliest opportunity.
1754 */
1755 void sqlite3_interrupt(sqlite3 *db){
1756 #ifdef SQLITE_ENABLE_API_ARMOR
1757   if( !sqlite3SafetyCheckOk(db) && (db==0 || db->magic!=SQLITE_MAGIC_ZOMBIE) ){
1758     (void)SQLITE_MISUSE_BKPT;
1759     return;
1760   }
1761 #endif
1762   AtomicStore(&db->u1.isInterrupted, 1);
1763 }
1764 
1765 
1766 /*
1767 ** This function is exactly the same as sqlite3_create_function(), except
1768 ** that it is designed to be called by internal code. The difference is
1769 ** that if a malloc() fails in sqlite3_create_function(), an error code
1770 ** is returned and the mallocFailed flag cleared.
1771 */
1772 int sqlite3CreateFunc(
1773   sqlite3 *db,
1774   const char *zFunctionName,
1775   int nArg,
1776   int enc,
1777   void *pUserData,
1778   void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
1779   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
1780   void (*xFinal)(sqlite3_context*),
1781   void (*xValue)(sqlite3_context*),
1782   void (*xInverse)(sqlite3_context*,int,sqlite3_value **),
1783   FuncDestructor *pDestructor
1784 ){
1785   FuncDef *p;
1786   int nName;
1787   int extraFlags;
1788 
1789   assert( sqlite3_mutex_held(db->mutex) );
1790   assert( xValue==0 || xSFunc==0 );
1791   if( zFunctionName==0                /* Must have a valid name */
1792    || (xSFunc!=0 && xFinal!=0)        /* Not both xSFunc and xFinal */
1793    || ((xFinal==0)!=(xStep==0))       /* Both or neither of xFinal and xStep */
1794    || ((xValue==0)!=(xInverse==0))    /* Both or neither of xValue, xInverse */
1795    || (nArg<-1 || nArg>SQLITE_MAX_FUNCTION_ARG)
1796    || (255<(nName = sqlite3Strlen30( zFunctionName)))
1797   ){
1798     return SQLITE_MISUSE_BKPT;
1799   }
1800 
1801   assert( SQLITE_FUNC_CONSTANT==SQLITE_DETERMINISTIC );
1802   assert( SQLITE_FUNC_DIRECT==SQLITE_DIRECTONLY );
1803   extraFlags = enc &  (SQLITE_DETERMINISTIC|SQLITE_DIRECTONLY|
1804                        SQLITE_SUBTYPE|SQLITE_INNOCUOUS);
1805   enc &= (SQLITE_FUNC_ENCMASK|SQLITE_ANY);
1806 
1807   /* The SQLITE_INNOCUOUS flag is the same bit as SQLITE_FUNC_UNSAFE.  But
1808   ** the meaning is inverted.  So flip the bit. */
1809   assert( SQLITE_FUNC_UNSAFE==SQLITE_INNOCUOUS );
1810   extraFlags ^= SQLITE_FUNC_UNSAFE;
1811 
1812 
1813 #ifndef SQLITE_OMIT_UTF16
1814   /* If SQLITE_UTF16 is specified as the encoding type, transform this
1815   ** to one of SQLITE_UTF16LE or SQLITE_UTF16BE using the
1816   ** SQLITE_UTF16NATIVE macro. SQLITE_UTF16 is not used internally.
1817   **
1818   ** If SQLITE_ANY is specified, add three versions of the function
1819   ** to the hash table.
1820   */
1821   if( enc==SQLITE_UTF16 ){
1822     enc = SQLITE_UTF16NATIVE;
1823   }else if( enc==SQLITE_ANY ){
1824     int rc;
1825     rc = sqlite3CreateFunc(db, zFunctionName, nArg,
1826          (SQLITE_UTF8|extraFlags)^SQLITE_FUNC_UNSAFE,
1827          pUserData, xSFunc, xStep, xFinal, xValue, xInverse, pDestructor);
1828     if( rc==SQLITE_OK ){
1829       rc = sqlite3CreateFunc(db, zFunctionName, nArg,
1830            (SQLITE_UTF16LE|extraFlags)^SQLITE_FUNC_UNSAFE,
1831            pUserData, xSFunc, xStep, xFinal, xValue, xInverse, pDestructor);
1832     }
1833     if( rc!=SQLITE_OK ){
1834       return rc;
1835     }
1836     enc = SQLITE_UTF16BE;
1837   }
1838 #else
1839   enc = SQLITE_UTF8;
1840 #endif
1841 
1842   /* Check if an existing function is being overridden or deleted. If so,
1843   ** and there are active VMs, then return SQLITE_BUSY. If a function
1844   ** is being overridden/deleted but there are no active VMs, allow the
1845   ** operation to continue but invalidate all precompiled statements.
1846   */
1847   p = sqlite3FindFunction(db, zFunctionName, nArg, (u8)enc, 0);
1848   if( p && (p->funcFlags & SQLITE_FUNC_ENCMASK)==(u32)enc && p->nArg==nArg ){
1849     if( db->nVdbeActive ){
1850       sqlite3ErrorWithMsg(db, SQLITE_BUSY,
1851         "unable to delete/modify user-function due to active statements");
1852       assert( !db->mallocFailed );
1853       return SQLITE_BUSY;
1854     }else{
1855       sqlite3ExpirePreparedStatements(db, 0);
1856     }
1857   }
1858 
1859   p = sqlite3FindFunction(db, zFunctionName, nArg, (u8)enc, 1);
1860   assert(p || db->mallocFailed);
1861   if( !p ){
1862     return SQLITE_NOMEM_BKPT;
1863   }
1864 
1865   /* If an older version of the function with a configured destructor is
1866   ** being replaced invoke the destructor function here. */
1867   functionDestroy(db, p);
1868 
1869   if( pDestructor ){
1870     pDestructor->nRef++;
1871   }
1872   p->u.pDestructor = pDestructor;
1873   p->funcFlags = (p->funcFlags & SQLITE_FUNC_ENCMASK) | extraFlags;
1874   testcase( p->funcFlags & SQLITE_DETERMINISTIC );
1875   testcase( p->funcFlags & SQLITE_DIRECTONLY );
1876   p->xSFunc = xSFunc ? xSFunc : xStep;
1877   p->xFinalize = xFinal;
1878   p->xValue = xValue;
1879   p->xInverse = xInverse;
1880   p->pUserData = pUserData;
1881   p->nArg = (u16)nArg;
1882   return SQLITE_OK;
1883 }
1884 
1885 /*
1886 ** Worker function used by utf-8 APIs that create new functions:
1887 **
1888 **    sqlite3_create_function()
1889 **    sqlite3_create_function_v2()
1890 **    sqlite3_create_window_function()
1891 */
1892 static int createFunctionApi(
1893   sqlite3 *db,
1894   const char *zFunc,
1895   int nArg,
1896   int enc,
1897   void *p,
1898   void (*xSFunc)(sqlite3_context*,int,sqlite3_value**),
1899   void (*xStep)(sqlite3_context*,int,sqlite3_value**),
1900   void (*xFinal)(sqlite3_context*),
1901   void (*xValue)(sqlite3_context*),
1902   void (*xInverse)(sqlite3_context*,int,sqlite3_value**),
1903   void(*xDestroy)(void*)
1904 ){
1905   int rc = SQLITE_ERROR;
1906   FuncDestructor *pArg = 0;
1907 
1908 #ifdef SQLITE_ENABLE_API_ARMOR
1909   if( !sqlite3SafetyCheckOk(db) ){
1910     return SQLITE_MISUSE_BKPT;
1911   }
1912 #endif
1913   sqlite3_mutex_enter(db->mutex);
1914   if( xDestroy ){
1915     pArg = (FuncDestructor *)sqlite3Malloc(sizeof(FuncDestructor));
1916     if( !pArg ){
1917       sqlite3OomFault(db);
1918       xDestroy(p);
1919       goto out;
1920     }
1921     pArg->nRef = 0;
1922     pArg->xDestroy = xDestroy;
1923     pArg->pUserData = p;
1924   }
1925   rc = sqlite3CreateFunc(db, zFunc, nArg, enc, p,
1926       xSFunc, xStep, xFinal, xValue, xInverse, pArg
1927   );
1928   if( pArg && pArg->nRef==0 ){
1929     assert( rc!=SQLITE_OK );
1930     xDestroy(p);
1931     sqlite3_free(pArg);
1932   }
1933 
1934  out:
1935   rc = sqlite3ApiExit(db, rc);
1936   sqlite3_mutex_leave(db->mutex);
1937   return rc;
1938 }
1939 
1940 /*
1941 ** Create new user functions.
1942 */
1943 int sqlite3_create_function(
1944   sqlite3 *db,
1945   const char *zFunc,
1946   int nArg,
1947   int enc,
1948   void *p,
1949   void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
1950   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
1951   void (*xFinal)(sqlite3_context*)
1952 ){
1953   return createFunctionApi(db, zFunc, nArg, enc, p, xSFunc, xStep,
1954                                     xFinal, 0, 0, 0);
1955 }
1956 int sqlite3_create_function_v2(
1957   sqlite3 *db,
1958   const char *zFunc,
1959   int nArg,
1960   int enc,
1961   void *p,
1962   void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
1963   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
1964   void (*xFinal)(sqlite3_context*),
1965   void (*xDestroy)(void *)
1966 ){
1967   return createFunctionApi(db, zFunc, nArg, enc, p, xSFunc, xStep,
1968                                     xFinal, 0, 0, xDestroy);
1969 }
1970 int sqlite3_create_window_function(
1971   sqlite3 *db,
1972   const char *zFunc,
1973   int nArg,
1974   int enc,
1975   void *p,
1976   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
1977   void (*xFinal)(sqlite3_context*),
1978   void (*xValue)(sqlite3_context*),
1979   void (*xInverse)(sqlite3_context*,int,sqlite3_value **),
1980   void (*xDestroy)(void *)
1981 ){
1982   return createFunctionApi(db, zFunc, nArg, enc, p, 0, xStep,
1983                                     xFinal, xValue, xInverse, xDestroy);
1984 }
1985 
1986 #ifndef SQLITE_OMIT_UTF16
1987 int sqlite3_create_function16(
1988   sqlite3 *db,
1989   const void *zFunctionName,
1990   int nArg,
1991   int eTextRep,
1992   void *p,
1993   void (*xSFunc)(sqlite3_context*,int,sqlite3_value**),
1994   void (*xStep)(sqlite3_context*,int,sqlite3_value**),
1995   void (*xFinal)(sqlite3_context*)
1996 ){
1997   int rc;
1998   char *zFunc8;
1999 
2000 #ifdef SQLITE_ENABLE_API_ARMOR
2001   if( !sqlite3SafetyCheckOk(db) || zFunctionName==0 ) return SQLITE_MISUSE_BKPT;
2002 #endif
2003   sqlite3_mutex_enter(db->mutex);
2004   assert( !db->mallocFailed );
2005   zFunc8 = sqlite3Utf16to8(db, zFunctionName, -1, SQLITE_UTF16NATIVE);
2006   rc = sqlite3CreateFunc(db, zFunc8, nArg, eTextRep, p, xSFunc,xStep,xFinal,0,0,0);
2007   sqlite3DbFree(db, zFunc8);
2008   rc = sqlite3ApiExit(db, rc);
2009   sqlite3_mutex_leave(db->mutex);
2010   return rc;
2011 }
2012 #endif
2013 
2014 
2015 /*
2016 ** The following is the implementation of an SQL function that always
2017 ** fails with an error message stating that the function is used in the
2018 ** wrong context.  The sqlite3_overload_function() API might construct
2019 ** SQL function that use this routine so that the functions will exist
2020 ** for name resolution but are actually overloaded by the xFindFunction
2021 ** method of virtual tables.
2022 */
2023 static void sqlite3InvalidFunction(
2024   sqlite3_context *context,  /* The function calling context */
2025   int NotUsed,               /* Number of arguments to the function */
2026   sqlite3_value **NotUsed2   /* Value of each argument */
2027 ){
2028   const char *zName = (const char*)sqlite3_user_data(context);
2029   char *zErr;
2030   UNUSED_PARAMETER2(NotUsed, NotUsed2);
2031   zErr = sqlite3_mprintf(
2032       "unable to use function %s in the requested context", zName);
2033   sqlite3_result_error(context, zErr, -1);
2034   sqlite3_free(zErr);
2035 }
2036 
2037 /*
2038 ** Declare that a function has been overloaded by a virtual table.
2039 **
2040 ** If the function already exists as a regular global function, then
2041 ** this routine is a no-op.  If the function does not exist, then create
2042 ** a new one that always throws a run-time error.
2043 **
2044 ** When virtual tables intend to provide an overloaded function, they
2045 ** should call this routine to make sure the global function exists.
2046 ** A global function must exist in order for name resolution to work
2047 ** properly.
2048 */
2049 int sqlite3_overload_function(
2050   sqlite3 *db,
2051   const char *zName,
2052   int nArg
2053 ){
2054   int rc;
2055   char *zCopy;
2056 
2057 #ifdef SQLITE_ENABLE_API_ARMOR
2058   if( !sqlite3SafetyCheckOk(db) || zName==0 || nArg<-2 ){
2059     return SQLITE_MISUSE_BKPT;
2060   }
2061 #endif
2062   sqlite3_mutex_enter(db->mutex);
2063   rc = sqlite3FindFunction(db, zName, nArg, SQLITE_UTF8, 0)!=0;
2064   sqlite3_mutex_leave(db->mutex);
2065   if( rc ) return SQLITE_OK;
2066   zCopy = sqlite3_mprintf(zName);
2067   if( zCopy==0 ) return SQLITE_NOMEM;
2068   return sqlite3_create_function_v2(db, zName, nArg, SQLITE_UTF8,
2069                            zCopy, sqlite3InvalidFunction, 0, 0, sqlite3_free);
2070 }
2071 
2072 #ifndef SQLITE_OMIT_TRACE
2073 /*
2074 ** Register a trace function.  The pArg from the previously registered trace
2075 ** is returned.
2076 **
2077 ** A NULL trace function means that no tracing is executes.  A non-NULL
2078 ** trace is a pointer to a function that is invoked at the start of each
2079 ** SQL statement.
2080 */
2081 #ifndef SQLITE_OMIT_DEPRECATED
2082 void *sqlite3_trace(sqlite3 *db, void(*xTrace)(void*,const char*), void *pArg){
2083   void *pOld;
2084 
2085 #ifdef SQLITE_ENABLE_API_ARMOR
2086   if( !sqlite3SafetyCheckOk(db) ){
2087     (void)SQLITE_MISUSE_BKPT;
2088     return 0;
2089   }
2090 #endif
2091   sqlite3_mutex_enter(db->mutex);
2092   pOld = db->pTraceArg;
2093   db->mTrace = xTrace ? SQLITE_TRACE_LEGACY : 0;
2094   db->xTrace = (int(*)(u32,void*,void*,void*))xTrace;
2095   db->pTraceArg = pArg;
2096   sqlite3_mutex_leave(db->mutex);
2097   return pOld;
2098 }
2099 #endif /* SQLITE_OMIT_DEPRECATED */
2100 
2101 /* Register a trace callback using the version-2 interface.
2102 */
2103 int sqlite3_trace_v2(
2104   sqlite3 *db,                               /* Trace this connection */
2105   unsigned mTrace,                           /* Mask of events to be traced */
2106   int(*xTrace)(unsigned,void*,void*,void*),  /* Callback to invoke */
2107   void *pArg                                 /* Context */
2108 ){
2109 #ifdef SQLITE_ENABLE_API_ARMOR
2110   if( !sqlite3SafetyCheckOk(db) ){
2111     return SQLITE_MISUSE_BKPT;
2112   }
2113 #endif
2114   sqlite3_mutex_enter(db->mutex);
2115   if( mTrace==0 ) xTrace = 0;
2116   if( xTrace==0 ) mTrace = 0;
2117   db->mTrace = mTrace;
2118   db->xTrace = xTrace;
2119   db->pTraceArg = pArg;
2120   sqlite3_mutex_leave(db->mutex);
2121   return SQLITE_OK;
2122 }
2123 
2124 #ifndef SQLITE_OMIT_DEPRECATED
2125 /*
2126 ** Register a profile function.  The pArg from the previously registered
2127 ** profile function is returned.
2128 **
2129 ** A NULL profile function means that no profiling is executes.  A non-NULL
2130 ** profile is a pointer to a function that is invoked at the conclusion of
2131 ** each SQL statement that is run.
2132 */
2133 void *sqlite3_profile(
2134   sqlite3 *db,
2135   void (*xProfile)(void*,const char*,sqlite_uint64),
2136   void *pArg
2137 ){
2138   void *pOld;
2139 
2140 #ifdef SQLITE_ENABLE_API_ARMOR
2141   if( !sqlite3SafetyCheckOk(db) ){
2142     (void)SQLITE_MISUSE_BKPT;
2143     return 0;
2144   }
2145 #endif
2146   sqlite3_mutex_enter(db->mutex);
2147   pOld = db->pProfileArg;
2148   db->xProfile = xProfile;
2149   db->pProfileArg = pArg;
2150   db->mTrace &= SQLITE_TRACE_NONLEGACY_MASK;
2151   if( db->xProfile ) db->mTrace |= SQLITE_TRACE_XPROFILE;
2152   sqlite3_mutex_leave(db->mutex);
2153   return pOld;
2154 }
2155 #endif /* SQLITE_OMIT_DEPRECATED */
2156 #endif /* SQLITE_OMIT_TRACE */
2157 
2158 /*
2159 ** Register a function to be invoked when a transaction commits.
2160 ** If the invoked function returns non-zero, then the commit becomes a
2161 ** rollback.
2162 */
2163 void *sqlite3_commit_hook(
2164   sqlite3 *db,              /* Attach the hook to this database */
2165   int (*xCallback)(void*),  /* Function to invoke on each commit */
2166   void *pArg                /* Argument to the function */
2167 ){
2168   void *pOld;
2169 
2170 #ifdef SQLITE_ENABLE_API_ARMOR
2171   if( !sqlite3SafetyCheckOk(db) ){
2172     (void)SQLITE_MISUSE_BKPT;
2173     return 0;
2174   }
2175 #endif
2176   sqlite3_mutex_enter(db->mutex);
2177   pOld = db->pCommitArg;
2178   db->xCommitCallback = xCallback;
2179   db->pCommitArg = pArg;
2180   sqlite3_mutex_leave(db->mutex);
2181   return pOld;
2182 }
2183 
2184 /*
2185 ** Register a callback to be invoked each time a row is updated,
2186 ** inserted or deleted using this database connection.
2187 */
2188 void *sqlite3_update_hook(
2189   sqlite3 *db,              /* Attach the hook to this database */
2190   void (*xCallback)(void*,int,char const *,char const *,sqlite_int64),
2191   void *pArg                /* Argument to the function */
2192 ){
2193   void *pRet;
2194 
2195 #ifdef SQLITE_ENABLE_API_ARMOR
2196   if( !sqlite3SafetyCheckOk(db) ){
2197     (void)SQLITE_MISUSE_BKPT;
2198     return 0;
2199   }
2200 #endif
2201   sqlite3_mutex_enter(db->mutex);
2202   pRet = db->pUpdateArg;
2203   db->xUpdateCallback = xCallback;
2204   db->pUpdateArg = pArg;
2205   sqlite3_mutex_leave(db->mutex);
2206   return pRet;
2207 }
2208 
2209 /*
2210 ** Register a callback to be invoked each time a transaction is rolled
2211 ** back by this database connection.
2212 */
2213 void *sqlite3_rollback_hook(
2214   sqlite3 *db,              /* Attach the hook to this database */
2215   void (*xCallback)(void*), /* Callback function */
2216   void *pArg                /* Argument to the function */
2217 ){
2218   void *pRet;
2219 
2220 #ifdef SQLITE_ENABLE_API_ARMOR
2221   if( !sqlite3SafetyCheckOk(db) ){
2222     (void)SQLITE_MISUSE_BKPT;
2223     return 0;
2224   }
2225 #endif
2226   sqlite3_mutex_enter(db->mutex);
2227   pRet = db->pRollbackArg;
2228   db->xRollbackCallback = xCallback;
2229   db->pRollbackArg = pArg;
2230   sqlite3_mutex_leave(db->mutex);
2231   return pRet;
2232 }
2233 
2234 #ifdef SQLITE_ENABLE_PREUPDATE_HOOK
2235 /*
2236 ** Register a callback to be invoked each time a row is updated,
2237 ** inserted or deleted using this database connection.
2238 */
2239 void *sqlite3_preupdate_hook(
2240   sqlite3 *db,              /* Attach the hook to this database */
2241   void(*xCallback)(         /* Callback function */
2242     void*,sqlite3*,int,char const*,char const*,sqlite3_int64,sqlite3_int64),
2243   void *pArg                /* First callback argument */
2244 ){
2245   void *pRet;
2246   sqlite3_mutex_enter(db->mutex);
2247   pRet = db->pPreUpdateArg;
2248   db->xPreUpdateCallback = xCallback;
2249   db->pPreUpdateArg = pArg;
2250   sqlite3_mutex_leave(db->mutex);
2251   return pRet;
2252 }
2253 #endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
2254 
2255 #ifndef SQLITE_OMIT_WAL
2256 /*
2257 ** The sqlite3_wal_hook() callback registered by sqlite3_wal_autocheckpoint().
2258 ** Invoke sqlite3_wal_checkpoint if the number of frames in the log file
2259 ** is greater than sqlite3.pWalArg cast to an integer (the value configured by
2260 ** wal_autocheckpoint()).
2261 */
2262 int sqlite3WalDefaultHook(
2263   void *pClientData,     /* Argument */
2264   sqlite3 *db,           /* Connection */
2265   const char *zDb,       /* Database */
2266   int nFrame             /* Size of WAL */
2267 ){
2268   if( nFrame>=SQLITE_PTR_TO_INT(pClientData) ){
2269     sqlite3BeginBenignMalloc();
2270     sqlite3_wal_checkpoint(db, zDb);
2271     sqlite3EndBenignMalloc();
2272   }
2273   return SQLITE_OK;
2274 }
2275 #endif /* SQLITE_OMIT_WAL */
2276 
2277 /*
2278 ** Configure an sqlite3_wal_hook() callback to automatically checkpoint
2279 ** a database after committing a transaction if there are nFrame or
2280 ** more frames in the log file. Passing zero or a negative value as the
2281 ** nFrame parameter disables automatic checkpoints entirely.
2282 **
2283 ** The callback registered by this function replaces any existing callback
2284 ** registered using sqlite3_wal_hook(). Likewise, registering a callback
2285 ** using sqlite3_wal_hook() disables the automatic checkpoint mechanism
2286 ** configured by this function.
2287 */
2288 int sqlite3_wal_autocheckpoint(sqlite3 *db, int nFrame){
2289 #ifdef SQLITE_OMIT_WAL
2290   UNUSED_PARAMETER(db);
2291   UNUSED_PARAMETER(nFrame);
2292 #else
2293 #ifdef SQLITE_ENABLE_API_ARMOR
2294   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
2295 #endif
2296   if( nFrame>0 ){
2297     sqlite3_wal_hook(db, sqlite3WalDefaultHook, SQLITE_INT_TO_PTR(nFrame));
2298   }else{
2299     sqlite3_wal_hook(db, 0, 0);
2300   }
2301 #endif
2302   return SQLITE_OK;
2303 }
2304 
2305 /*
2306 ** Register a callback to be invoked each time a transaction is written
2307 ** into the write-ahead-log by this database connection.
2308 */
2309 void *sqlite3_wal_hook(
2310   sqlite3 *db,                    /* Attach the hook to this db handle */
2311   int(*xCallback)(void *, sqlite3*, const char*, int),
2312   void *pArg                      /* First argument passed to xCallback() */
2313 ){
2314 #ifndef SQLITE_OMIT_WAL
2315   void *pRet;
2316 #ifdef SQLITE_ENABLE_API_ARMOR
2317   if( !sqlite3SafetyCheckOk(db) ){
2318     (void)SQLITE_MISUSE_BKPT;
2319     return 0;
2320   }
2321 #endif
2322   sqlite3_mutex_enter(db->mutex);
2323   pRet = db->pWalArg;
2324   db->xWalCallback = xCallback;
2325   db->pWalArg = pArg;
2326   sqlite3_mutex_leave(db->mutex);
2327   return pRet;
2328 #else
2329   return 0;
2330 #endif
2331 }
2332 
2333 /*
2334 ** Checkpoint database zDb.
2335 */
2336 int sqlite3_wal_checkpoint_v2(
2337   sqlite3 *db,                    /* Database handle */
2338   const char *zDb,                /* Name of attached database (or NULL) */
2339   int eMode,                      /* SQLITE_CHECKPOINT_* value */
2340   int *pnLog,                     /* OUT: Size of WAL log in frames */
2341   int *pnCkpt                     /* OUT: Total number of frames checkpointed */
2342 ){
2343 #ifdef SQLITE_OMIT_WAL
2344   return SQLITE_OK;
2345 #else
2346   int rc;                         /* Return code */
2347   int iDb = SQLITE_MAX_ATTACHED;  /* sqlite3.aDb[] index of db to checkpoint */
2348 
2349 #ifdef SQLITE_ENABLE_API_ARMOR
2350   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
2351 #endif
2352 
2353   /* Initialize the output variables to -1 in case an error occurs. */
2354   if( pnLog ) *pnLog = -1;
2355   if( pnCkpt ) *pnCkpt = -1;
2356 
2357   assert( SQLITE_CHECKPOINT_PASSIVE==0 );
2358   assert( SQLITE_CHECKPOINT_FULL==1 );
2359   assert( SQLITE_CHECKPOINT_RESTART==2 );
2360   assert( SQLITE_CHECKPOINT_TRUNCATE==3 );
2361   if( eMode<SQLITE_CHECKPOINT_PASSIVE || eMode>SQLITE_CHECKPOINT_TRUNCATE ){
2362     /* EVIDENCE-OF: R-03996-12088 The M parameter must be a valid checkpoint
2363     ** mode: */
2364     return SQLITE_MISUSE;
2365   }
2366 
2367   sqlite3_mutex_enter(db->mutex);
2368   if( zDb && zDb[0] ){
2369     iDb = sqlite3FindDbName(db, zDb);
2370   }
2371   if( iDb<0 ){
2372     rc = SQLITE_ERROR;
2373     sqlite3ErrorWithMsg(db, SQLITE_ERROR, "unknown database: %s", zDb);
2374   }else{
2375     db->busyHandler.nBusy = 0;
2376     rc = sqlite3Checkpoint(db, iDb, eMode, pnLog, pnCkpt);
2377     sqlite3Error(db, rc);
2378   }
2379   rc = sqlite3ApiExit(db, rc);
2380 
2381   /* If there are no active statements, clear the interrupt flag at this
2382   ** point.  */
2383   if( db->nVdbeActive==0 ){
2384     AtomicStore(&db->u1.isInterrupted, 0);
2385   }
2386 
2387   sqlite3_mutex_leave(db->mutex);
2388   return rc;
2389 #endif
2390 }
2391 
2392 
2393 /*
2394 ** Checkpoint database zDb. If zDb is NULL, or if the buffer zDb points
2395 ** to contains a zero-length string, all attached databases are
2396 ** checkpointed.
2397 */
2398 int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb){
2399   /* EVIDENCE-OF: R-41613-20553 The sqlite3_wal_checkpoint(D,X) is equivalent to
2400   ** sqlite3_wal_checkpoint_v2(D,X,SQLITE_CHECKPOINT_PASSIVE,0,0). */
2401   return sqlite3_wal_checkpoint_v2(db,zDb,SQLITE_CHECKPOINT_PASSIVE,0,0);
2402 }
2403 
2404 #ifndef SQLITE_OMIT_WAL
2405 /*
2406 ** Run a checkpoint on database iDb. This is a no-op if database iDb is
2407 ** not currently open in WAL mode.
2408 **
2409 ** If a transaction is open on the database being checkpointed, this
2410 ** function returns SQLITE_LOCKED and a checkpoint is not attempted. If
2411 ** an error occurs while running the checkpoint, an SQLite error code is
2412 ** returned (i.e. SQLITE_IOERR). Otherwise, SQLITE_OK.
2413 **
2414 ** The mutex on database handle db should be held by the caller. The mutex
2415 ** associated with the specific b-tree being checkpointed is taken by
2416 ** this function while the checkpoint is running.
2417 **
2418 ** If iDb is passed SQLITE_MAX_ATTACHED, then all attached databases are
2419 ** checkpointed. If an error is encountered it is returned immediately -
2420 ** no attempt is made to checkpoint any remaining databases.
2421 **
2422 ** Parameter eMode is one of SQLITE_CHECKPOINT_PASSIVE, FULL, RESTART
2423 ** or TRUNCATE.
2424 */
2425 int sqlite3Checkpoint(sqlite3 *db, int iDb, int eMode, int *pnLog, int *pnCkpt){
2426   int rc = SQLITE_OK;             /* Return code */
2427   int i;                          /* Used to iterate through attached dbs */
2428   int bBusy = 0;                  /* True if SQLITE_BUSY has been encountered */
2429 
2430   assert( sqlite3_mutex_held(db->mutex) );
2431   assert( !pnLog || *pnLog==-1 );
2432   assert( !pnCkpt || *pnCkpt==-1 );
2433 
2434   for(i=0; i<db->nDb && rc==SQLITE_OK; i++){
2435     if( i==iDb || iDb==SQLITE_MAX_ATTACHED ){
2436       rc = sqlite3BtreeCheckpoint(db->aDb[i].pBt, eMode, pnLog, pnCkpt);
2437       pnLog = 0;
2438       pnCkpt = 0;
2439       if( rc==SQLITE_BUSY ){
2440         bBusy = 1;
2441         rc = SQLITE_OK;
2442       }
2443     }
2444   }
2445 
2446   return (rc==SQLITE_OK && bBusy) ? SQLITE_BUSY : rc;
2447 }
2448 #endif /* SQLITE_OMIT_WAL */
2449 
2450 /*
2451 ** This function returns true if main-memory should be used instead of
2452 ** a temporary file for transient pager files and statement journals.
2453 ** The value returned depends on the value of db->temp_store (runtime
2454 ** parameter) and the compile time value of SQLITE_TEMP_STORE. The
2455 ** following table describes the relationship between these two values
2456 ** and this functions return value.
2457 **
2458 **   SQLITE_TEMP_STORE     db->temp_store     Location of temporary database
2459 **   -----------------     --------------     ------------------------------
2460 **   0                     any                file      (return 0)
2461 **   1                     1                  file      (return 0)
2462 **   1                     2                  memory    (return 1)
2463 **   1                     0                  file      (return 0)
2464 **   2                     1                  file      (return 0)
2465 **   2                     2                  memory    (return 1)
2466 **   2                     0                  memory    (return 1)
2467 **   3                     any                memory    (return 1)
2468 */
2469 int sqlite3TempInMemory(const sqlite3 *db){
2470 #if SQLITE_TEMP_STORE==1
2471   return ( db->temp_store==2 );
2472 #endif
2473 #if SQLITE_TEMP_STORE==2
2474   return ( db->temp_store!=1 );
2475 #endif
2476 #if SQLITE_TEMP_STORE==3
2477   UNUSED_PARAMETER(db);
2478   return 1;
2479 #endif
2480 #if SQLITE_TEMP_STORE<1 || SQLITE_TEMP_STORE>3
2481   UNUSED_PARAMETER(db);
2482   return 0;
2483 #endif
2484 }
2485 
2486 /*
2487 ** Return UTF-8 encoded English language explanation of the most recent
2488 ** error.
2489 */
2490 const char *sqlite3_errmsg(sqlite3 *db){
2491   const char *z;
2492   if( !db ){
2493     return sqlite3ErrStr(SQLITE_NOMEM_BKPT);
2494   }
2495   if( !sqlite3SafetyCheckSickOrOk(db) ){
2496     return sqlite3ErrStr(SQLITE_MISUSE_BKPT);
2497   }
2498   sqlite3_mutex_enter(db->mutex);
2499   if( db->mallocFailed ){
2500     z = sqlite3ErrStr(SQLITE_NOMEM_BKPT);
2501   }else{
2502     testcase( db->pErr==0 );
2503     z = db->errCode ? (char*)sqlite3_value_text(db->pErr) : 0;
2504     assert( !db->mallocFailed );
2505     if( z==0 ){
2506       z = sqlite3ErrStr(db->errCode);
2507     }
2508   }
2509   sqlite3_mutex_leave(db->mutex);
2510   return z;
2511 }
2512 
2513 #ifndef SQLITE_OMIT_UTF16
2514 /*
2515 ** Return UTF-16 encoded English language explanation of the most recent
2516 ** error.
2517 */
2518 const void *sqlite3_errmsg16(sqlite3 *db){
2519   static const u16 outOfMem[] = {
2520     'o', 'u', 't', ' ', 'o', 'f', ' ', 'm', 'e', 'm', 'o', 'r', 'y', 0
2521   };
2522   static const u16 misuse[] = {
2523     'b', 'a', 'd', ' ', 'p', 'a', 'r', 'a', 'm', 'e', 't', 'e', 'r', ' ',
2524     'o', 'r', ' ', 'o', 't', 'h', 'e', 'r', ' ', 'A', 'P', 'I', ' ',
2525     'm', 'i', 's', 'u', 's', 'e', 0
2526   };
2527 
2528   const void *z;
2529   if( !db ){
2530     return (void *)outOfMem;
2531   }
2532   if( !sqlite3SafetyCheckSickOrOk(db) ){
2533     return (void *)misuse;
2534   }
2535   sqlite3_mutex_enter(db->mutex);
2536   if( db->mallocFailed ){
2537     z = (void *)outOfMem;
2538   }else{
2539     z = sqlite3_value_text16(db->pErr);
2540     if( z==0 ){
2541       sqlite3ErrorWithMsg(db, db->errCode, sqlite3ErrStr(db->errCode));
2542       z = sqlite3_value_text16(db->pErr);
2543     }
2544     /* A malloc() may have failed within the call to sqlite3_value_text16()
2545     ** above. If this is the case, then the db->mallocFailed flag needs to
2546     ** be cleared before returning. Do this directly, instead of via
2547     ** sqlite3ApiExit(), to avoid setting the database handle error message.
2548     */
2549     sqlite3OomClear(db);
2550   }
2551   sqlite3_mutex_leave(db->mutex);
2552   return z;
2553 }
2554 #endif /* SQLITE_OMIT_UTF16 */
2555 
2556 /*
2557 ** Return the most recent error code generated by an SQLite routine. If NULL is
2558 ** passed to this function, we assume a malloc() failed during sqlite3_open().
2559 */
2560 int sqlite3_errcode(sqlite3 *db){
2561   if( db && !sqlite3SafetyCheckSickOrOk(db) ){
2562     return SQLITE_MISUSE_BKPT;
2563   }
2564   if( !db || db->mallocFailed ){
2565     return SQLITE_NOMEM_BKPT;
2566   }
2567   return db->errCode & db->errMask;
2568 }
2569 int sqlite3_extended_errcode(sqlite3 *db){
2570   if( db && !sqlite3SafetyCheckSickOrOk(db) ){
2571     return SQLITE_MISUSE_BKPT;
2572   }
2573   if( !db || db->mallocFailed ){
2574     return SQLITE_NOMEM_BKPT;
2575   }
2576   return db->errCode;
2577 }
2578 int sqlite3_system_errno(sqlite3 *db){
2579   return db ? db->iSysErrno : 0;
2580 }
2581 
2582 /*
2583 ** Return a string that describes the kind of error specified in the
2584 ** argument.  For now, this simply calls the internal sqlite3ErrStr()
2585 ** function.
2586 */
2587 const char *sqlite3_errstr(int rc){
2588   return sqlite3ErrStr(rc);
2589 }
2590 
2591 /*
2592 ** Create a new collating function for database "db".  The name is zName
2593 ** and the encoding is enc.
2594 */
2595 static int createCollation(
2596   sqlite3* db,
2597   const char *zName,
2598   u8 enc,
2599   void* pCtx,
2600   int(*xCompare)(void*,int,const void*,int,const void*),
2601   void(*xDel)(void*)
2602 ){
2603   CollSeq *pColl;
2604   int enc2;
2605 
2606   assert( sqlite3_mutex_held(db->mutex) );
2607 
2608   /* If SQLITE_UTF16 is specified as the encoding type, transform this
2609   ** to one of SQLITE_UTF16LE or SQLITE_UTF16BE using the
2610   ** SQLITE_UTF16NATIVE macro. SQLITE_UTF16 is not used internally.
2611   */
2612   enc2 = enc;
2613   testcase( enc2==SQLITE_UTF16 );
2614   testcase( enc2==SQLITE_UTF16_ALIGNED );
2615   if( enc2==SQLITE_UTF16 || enc2==SQLITE_UTF16_ALIGNED ){
2616     enc2 = SQLITE_UTF16NATIVE;
2617   }
2618   if( enc2<SQLITE_UTF8 || enc2>SQLITE_UTF16BE ){
2619     return SQLITE_MISUSE_BKPT;
2620   }
2621 
2622   /* Check if this call is removing or replacing an existing collation
2623   ** sequence. If so, and there are active VMs, return busy. If there
2624   ** are no active VMs, invalidate any pre-compiled statements.
2625   */
2626   pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, 0);
2627   if( pColl && pColl->xCmp ){
2628     if( db->nVdbeActive ){
2629       sqlite3ErrorWithMsg(db, SQLITE_BUSY,
2630         "unable to delete/modify collation sequence due to active statements");
2631       return SQLITE_BUSY;
2632     }
2633     sqlite3ExpirePreparedStatements(db, 0);
2634 
2635     /* If collation sequence pColl was created directly by a call to
2636     ** sqlite3_create_collation, and not generated by synthCollSeq(),
2637     ** then any copies made by synthCollSeq() need to be invalidated.
2638     ** Also, collation destructor - CollSeq.xDel() - function may need
2639     ** to be called.
2640     */
2641     if( (pColl->enc & ~SQLITE_UTF16_ALIGNED)==enc2 ){
2642       CollSeq *aColl = sqlite3HashFind(&db->aCollSeq, zName);
2643       int j;
2644       for(j=0; j<3; j++){
2645         CollSeq *p = &aColl[j];
2646         if( p->enc==pColl->enc ){
2647           if( p->xDel ){
2648             p->xDel(p->pUser);
2649           }
2650           p->xCmp = 0;
2651         }
2652       }
2653     }
2654   }
2655 
2656   pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, 1);
2657   if( pColl==0 ) return SQLITE_NOMEM_BKPT;
2658   pColl->xCmp = xCompare;
2659   pColl->pUser = pCtx;
2660   pColl->xDel = xDel;
2661   pColl->enc = (u8)(enc2 | (enc & SQLITE_UTF16_ALIGNED));
2662   sqlite3Error(db, SQLITE_OK);
2663   return SQLITE_OK;
2664 }
2665 
2666 
2667 /*
2668 ** This array defines hard upper bounds on limit values.  The
2669 ** initializer must be kept in sync with the SQLITE_LIMIT_*
2670 ** #defines in sqlite3.h.
2671 */
2672 static const int aHardLimit[] = {
2673   SQLITE_MAX_LENGTH,
2674   SQLITE_MAX_SQL_LENGTH,
2675   SQLITE_MAX_COLUMN,
2676   SQLITE_MAX_EXPR_DEPTH,
2677   SQLITE_MAX_COMPOUND_SELECT,
2678   SQLITE_MAX_VDBE_OP,
2679   SQLITE_MAX_FUNCTION_ARG,
2680   SQLITE_MAX_ATTACHED,
2681   SQLITE_MAX_LIKE_PATTERN_LENGTH,
2682   SQLITE_MAX_VARIABLE_NUMBER,      /* IMP: R-38091-32352 */
2683   SQLITE_MAX_TRIGGER_DEPTH,
2684   SQLITE_MAX_WORKER_THREADS,
2685 };
2686 
2687 /*
2688 ** Make sure the hard limits are set to reasonable values
2689 */
2690 #if SQLITE_MAX_LENGTH<100
2691 # error SQLITE_MAX_LENGTH must be at least 100
2692 #endif
2693 #if SQLITE_MAX_SQL_LENGTH<100
2694 # error SQLITE_MAX_SQL_LENGTH must be at least 100
2695 #endif
2696 #if SQLITE_MAX_SQL_LENGTH>SQLITE_MAX_LENGTH
2697 # error SQLITE_MAX_SQL_LENGTH must not be greater than SQLITE_MAX_LENGTH
2698 #endif
2699 #if SQLITE_MAX_COMPOUND_SELECT<2
2700 # error SQLITE_MAX_COMPOUND_SELECT must be at least 2
2701 #endif
2702 #if SQLITE_MAX_VDBE_OP<40
2703 # error SQLITE_MAX_VDBE_OP must be at least 40
2704 #endif
2705 #if SQLITE_MAX_FUNCTION_ARG<0 || SQLITE_MAX_FUNCTION_ARG>127
2706 # error SQLITE_MAX_FUNCTION_ARG must be between 0 and 127
2707 #endif
2708 #if SQLITE_MAX_ATTACHED<0 || SQLITE_MAX_ATTACHED>125
2709 # error SQLITE_MAX_ATTACHED must be between 0 and 125
2710 #endif
2711 #if SQLITE_MAX_LIKE_PATTERN_LENGTH<1
2712 # error SQLITE_MAX_LIKE_PATTERN_LENGTH must be at least 1
2713 #endif
2714 #if SQLITE_MAX_COLUMN>32767
2715 # error SQLITE_MAX_COLUMN must not exceed 32767
2716 #endif
2717 #if SQLITE_MAX_TRIGGER_DEPTH<1
2718 # error SQLITE_MAX_TRIGGER_DEPTH must be at least 1
2719 #endif
2720 #if SQLITE_MAX_WORKER_THREADS<0 || SQLITE_MAX_WORKER_THREADS>50
2721 # error SQLITE_MAX_WORKER_THREADS must be between 0 and 50
2722 #endif
2723 
2724 
2725 /*
2726 ** Change the value of a limit.  Report the old value.
2727 ** If an invalid limit index is supplied, report -1.
2728 ** Make no changes but still report the old value if the
2729 ** new limit is negative.
2730 **
2731 ** A new lower limit does not shrink existing constructs.
2732 ** It merely prevents new constructs that exceed the limit
2733 ** from forming.
2734 */
2735 int sqlite3_limit(sqlite3 *db, int limitId, int newLimit){
2736   int oldLimit;
2737 
2738 #ifdef SQLITE_ENABLE_API_ARMOR
2739   if( !sqlite3SafetyCheckOk(db) ){
2740     (void)SQLITE_MISUSE_BKPT;
2741     return -1;
2742   }
2743 #endif
2744 
2745   /* EVIDENCE-OF: R-30189-54097 For each limit category SQLITE_LIMIT_NAME
2746   ** there is a hard upper bound set at compile-time by a C preprocessor
2747   ** macro called SQLITE_MAX_NAME. (The "_LIMIT_" in the name is changed to
2748   ** "_MAX_".)
2749   */
2750   assert( aHardLimit[SQLITE_LIMIT_LENGTH]==SQLITE_MAX_LENGTH );
2751   assert( aHardLimit[SQLITE_LIMIT_SQL_LENGTH]==SQLITE_MAX_SQL_LENGTH );
2752   assert( aHardLimit[SQLITE_LIMIT_COLUMN]==SQLITE_MAX_COLUMN );
2753   assert( aHardLimit[SQLITE_LIMIT_EXPR_DEPTH]==SQLITE_MAX_EXPR_DEPTH );
2754   assert( aHardLimit[SQLITE_LIMIT_COMPOUND_SELECT]==SQLITE_MAX_COMPOUND_SELECT);
2755   assert( aHardLimit[SQLITE_LIMIT_VDBE_OP]==SQLITE_MAX_VDBE_OP );
2756   assert( aHardLimit[SQLITE_LIMIT_FUNCTION_ARG]==SQLITE_MAX_FUNCTION_ARG );
2757   assert( aHardLimit[SQLITE_LIMIT_ATTACHED]==SQLITE_MAX_ATTACHED );
2758   assert( aHardLimit[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]==
2759                                                SQLITE_MAX_LIKE_PATTERN_LENGTH );
2760   assert( aHardLimit[SQLITE_LIMIT_VARIABLE_NUMBER]==SQLITE_MAX_VARIABLE_NUMBER);
2761   assert( aHardLimit[SQLITE_LIMIT_TRIGGER_DEPTH]==SQLITE_MAX_TRIGGER_DEPTH );
2762   assert( aHardLimit[SQLITE_LIMIT_WORKER_THREADS]==SQLITE_MAX_WORKER_THREADS );
2763   assert( SQLITE_LIMIT_WORKER_THREADS==(SQLITE_N_LIMIT-1) );
2764 
2765 
2766   if( limitId<0 || limitId>=SQLITE_N_LIMIT ){
2767     return -1;
2768   }
2769   oldLimit = db->aLimit[limitId];
2770   if( newLimit>=0 ){                   /* IMP: R-52476-28732 */
2771     if( newLimit>aHardLimit[limitId] ){
2772       newLimit = aHardLimit[limitId];  /* IMP: R-51463-25634 */
2773     }
2774     db->aLimit[limitId] = newLimit;
2775   }
2776   return oldLimit;                     /* IMP: R-53341-35419 */
2777 }
2778 
2779 /*
2780 ** This function is used to parse both URIs and non-URI filenames passed by the
2781 ** user to API functions sqlite3_open() or sqlite3_open_v2(), and for database
2782 ** URIs specified as part of ATTACH statements.
2783 **
2784 ** The first argument to this function is the name of the VFS to use (or
2785 ** a NULL to signify the default VFS) if the URI does not contain a "vfs=xxx"
2786 ** query parameter. The second argument contains the URI (or non-URI filename)
2787 ** itself. When this function is called the *pFlags variable should contain
2788 ** the default flags to open the database handle with. The value stored in
2789 ** *pFlags may be updated before returning if the URI filename contains
2790 ** "cache=xxx" or "mode=xxx" query parameters.
2791 **
2792 ** If successful, SQLITE_OK is returned. In this case *ppVfs is set to point to
2793 ** the VFS that should be used to open the database file. *pzFile is set to
2794 ** point to a buffer containing the name of the file to open.  The value
2795 ** stored in *pzFile is a database name acceptable to sqlite3_uri_parameter()
2796 ** and is in the same format as names created using sqlite3_create_filename().
2797 ** The caller must invoke sqlite3_free_filename() (not sqlite3_free()!) on
2798 ** the value returned in *pzFile to avoid a memory leak.
2799 **
2800 ** If an error occurs, then an SQLite error code is returned and *pzErrMsg
2801 ** may be set to point to a buffer containing an English language error
2802 ** message. It is the responsibility of the caller to eventually release
2803 ** this buffer by calling sqlite3_free().
2804 */
2805 int sqlite3ParseUri(
2806   const char *zDefaultVfs,        /* VFS to use if no "vfs=xxx" query option */
2807   const char *zUri,               /* Nul-terminated URI to parse */
2808   unsigned int *pFlags,           /* IN/OUT: SQLITE_OPEN_XXX flags */
2809   sqlite3_vfs **ppVfs,            /* OUT: VFS to use */
2810   char **pzFile,                  /* OUT: Filename component of URI */
2811   char **pzErrMsg                 /* OUT: Error message (if rc!=SQLITE_OK) */
2812 ){
2813   int rc = SQLITE_OK;
2814   unsigned int flags = *pFlags;
2815   const char *zVfs = zDefaultVfs;
2816   char *zFile;
2817   char c;
2818   int nUri = sqlite3Strlen30(zUri);
2819 
2820   assert( *pzErrMsg==0 );
2821 
2822   if( ((flags & SQLITE_OPEN_URI)             /* IMP: R-48725-32206 */
2823             || sqlite3GlobalConfig.bOpenUri) /* IMP: R-51689-46548 */
2824    && nUri>=5 && memcmp(zUri, "file:", 5)==0 /* IMP: R-57884-37496 */
2825   ){
2826     char *zOpt;
2827     int eState;                   /* Parser state when parsing URI */
2828     int iIn;                      /* Input character index */
2829     int iOut = 0;                 /* Output character index */
2830     u64 nByte = nUri+8;           /* Bytes of space to allocate */
2831 
2832     /* Make sure the SQLITE_OPEN_URI flag is set to indicate to the VFS xOpen
2833     ** method that there may be extra parameters following the file-name.  */
2834     flags |= SQLITE_OPEN_URI;
2835 
2836     for(iIn=0; iIn<nUri; iIn++) nByte += (zUri[iIn]=='&');
2837     zFile = sqlite3_malloc64(nByte);
2838     if( !zFile ) return SQLITE_NOMEM_BKPT;
2839 
2840     memset(zFile, 0, 4);  /* 4-byte of 0x00 is the start of DB name marker */
2841     zFile += 4;
2842 
2843     iIn = 5;
2844 #ifdef SQLITE_ALLOW_URI_AUTHORITY
2845     if( strncmp(zUri+5, "///", 3)==0 ){
2846       iIn = 7;
2847       /* The following condition causes URIs with five leading / characters
2848       ** like file://///host/path to be converted into UNCs like //host/path.
2849       ** The correct URI for that UNC has only two or four leading / characters
2850       ** file://host/path or file:////host/path.  But 5 leading slashes is a
2851       ** common error, we are told, so we handle it as a special case. */
2852       if( strncmp(zUri+7, "///", 3)==0 ){ iIn++; }
2853     }else if( strncmp(zUri+5, "//localhost/", 12)==0 ){
2854       iIn = 16;
2855     }
2856 #else
2857     /* Discard the scheme and authority segments of the URI. */
2858     if( zUri[5]=='/' && zUri[6]=='/' ){
2859       iIn = 7;
2860       while( zUri[iIn] && zUri[iIn]!='/' ) iIn++;
2861       if( iIn!=7 && (iIn!=16 || memcmp("localhost", &zUri[7], 9)) ){
2862         *pzErrMsg = sqlite3_mprintf("invalid uri authority: %.*s",
2863             iIn-7, &zUri[7]);
2864         rc = SQLITE_ERROR;
2865         goto parse_uri_out;
2866       }
2867     }
2868 #endif
2869 
2870     /* Copy the filename and any query parameters into the zFile buffer.
2871     ** Decode %HH escape codes along the way.
2872     **
2873     ** Within this loop, variable eState may be set to 0, 1 or 2, depending
2874     ** on the parsing context. As follows:
2875     **
2876     **   0: Parsing file-name.
2877     **   1: Parsing name section of a name=value query parameter.
2878     **   2: Parsing value section of a name=value query parameter.
2879     */
2880     eState = 0;
2881     while( (c = zUri[iIn])!=0 && c!='#' ){
2882       iIn++;
2883       if( c=='%'
2884        && sqlite3Isxdigit(zUri[iIn])
2885        && sqlite3Isxdigit(zUri[iIn+1])
2886       ){
2887         int octet = (sqlite3HexToInt(zUri[iIn++]) << 4);
2888         octet += sqlite3HexToInt(zUri[iIn++]);
2889 
2890         assert( octet>=0 && octet<256 );
2891         if( octet==0 ){
2892 #ifndef SQLITE_ENABLE_URI_00_ERROR
2893           /* This branch is taken when "%00" appears within the URI. In this
2894           ** case we ignore all text in the remainder of the path, name or
2895           ** value currently being parsed. So ignore the current character
2896           ** and skip to the next "?", "=" or "&", as appropriate. */
2897           while( (c = zUri[iIn])!=0 && c!='#'
2898               && (eState!=0 || c!='?')
2899               && (eState!=1 || (c!='=' && c!='&'))
2900               && (eState!=2 || c!='&')
2901           ){
2902             iIn++;
2903           }
2904           continue;
2905 #else
2906           /* If ENABLE_URI_00_ERROR is defined, "%00" in a URI is an error. */
2907           *pzErrMsg = sqlite3_mprintf("unexpected %%00 in uri");
2908           rc = SQLITE_ERROR;
2909           goto parse_uri_out;
2910 #endif
2911         }
2912         c = octet;
2913       }else if( eState==1 && (c=='&' || c=='=') ){
2914         if( zFile[iOut-1]==0 ){
2915           /* An empty option name. Ignore this option altogether. */
2916           while( zUri[iIn] && zUri[iIn]!='#' && zUri[iIn-1]!='&' ) iIn++;
2917           continue;
2918         }
2919         if( c=='&' ){
2920           zFile[iOut++] = '\0';
2921         }else{
2922           eState = 2;
2923         }
2924         c = 0;
2925       }else if( (eState==0 && c=='?') || (eState==2 && c=='&') ){
2926         c = 0;
2927         eState = 1;
2928       }
2929       zFile[iOut++] = c;
2930     }
2931     if( eState==1 ) zFile[iOut++] = '\0';
2932     memset(zFile+iOut, 0, 4); /* end-of-options + empty journal filenames */
2933 
2934     /* Check if there were any options specified that should be interpreted
2935     ** here. Options that are interpreted here include "vfs" and those that
2936     ** correspond to flags that may be passed to the sqlite3_open_v2()
2937     ** method. */
2938     zOpt = &zFile[sqlite3Strlen30(zFile)+1];
2939     while( zOpt[0] ){
2940       int nOpt = sqlite3Strlen30(zOpt);
2941       char *zVal = &zOpt[nOpt+1];
2942       int nVal = sqlite3Strlen30(zVal);
2943 
2944       if( nOpt==3 && memcmp("vfs", zOpt, 3)==0 ){
2945         zVfs = zVal;
2946       }else{
2947         struct OpenMode {
2948           const char *z;
2949           int mode;
2950         } *aMode = 0;
2951         char *zModeType = 0;
2952         int mask = 0;
2953         int limit = 0;
2954 
2955         if( nOpt==5 && memcmp("cache", zOpt, 5)==0 ){
2956           static struct OpenMode aCacheMode[] = {
2957             { "shared",  SQLITE_OPEN_SHAREDCACHE },
2958             { "private", SQLITE_OPEN_PRIVATECACHE },
2959             { 0, 0 }
2960           };
2961 
2962           mask = SQLITE_OPEN_SHAREDCACHE|SQLITE_OPEN_PRIVATECACHE;
2963           aMode = aCacheMode;
2964           limit = mask;
2965           zModeType = "cache";
2966         }
2967         if( nOpt==4 && memcmp("mode", zOpt, 4)==0 ){
2968           static struct OpenMode aOpenMode[] = {
2969             { "ro",  SQLITE_OPEN_READONLY },
2970             { "rw",  SQLITE_OPEN_READWRITE },
2971             { "rwc", SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE },
2972             { "memory", SQLITE_OPEN_MEMORY },
2973             { 0, 0 }
2974           };
2975 
2976           mask = SQLITE_OPEN_READONLY | SQLITE_OPEN_READWRITE
2977                    | SQLITE_OPEN_CREATE | SQLITE_OPEN_MEMORY;
2978           aMode = aOpenMode;
2979           limit = mask & flags;
2980           zModeType = "access";
2981         }
2982 
2983         if( aMode ){
2984           int i;
2985           int mode = 0;
2986           for(i=0; aMode[i].z; i++){
2987             const char *z = aMode[i].z;
2988             if( nVal==sqlite3Strlen30(z) && 0==memcmp(zVal, z, nVal) ){
2989               mode = aMode[i].mode;
2990               break;
2991             }
2992           }
2993           if( mode==0 ){
2994             *pzErrMsg = sqlite3_mprintf("no such %s mode: %s", zModeType, zVal);
2995             rc = SQLITE_ERROR;
2996             goto parse_uri_out;
2997           }
2998           if( (mode & ~SQLITE_OPEN_MEMORY)>limit ){
2999             *pzErrMsg = sqlite3_mprintf("%s mode not allowed: %s",
3000                                         zModeType, zVal);
3001             rc = SQLITE_PERM;
3002             goto parse_uri_out;
3003           }
3004           flags = (flags & ~mask) | mode;
3005         }
3006       }
3007 
3008       zOpt = &zVal[nVal+1];
3009     }
3010 
3011   }else{
3012     zFile = sqlite3_malloc64(nUri+8);
3013     if( !zFile ) return SQLITE_NOMEM_BKPT;
3014     memset(zFile, 0, 4);
3015     zFile += 4;
3016     if( nUri ){
3017       memcpy(zFile, zUri, nUri);
3018     }
3019     memset(zFile+nUri, 0, 4);
3020     flags &= ~SQLITE_OPEN_URI;
3021   }
3022 
3023   *ppVfs = sqlite3_vfs_find(zVfs);
3024   if( *ppVfs==0 ){
3025     *pzErrMsg = sqlite3_mprintf("no such vfs: %s", zVfs);
3026     rc = SQLITE_ERROR;
3027   }
3028  parse_uri_out:
3029   if( rc!=SQLITE_OK ){
3030     sqlite3_free_filename(zFile);
3031     zFile = 0;
3032   }
3033   *pFlags = flags;
3034   *pzFile = zFile;
3035   return rc;
3036 }
3037 
3038 /*
3039 ** This routine does the core work of extracting URI parameters from a
3040 ** database filename for the sqlite3_uri_parameter() interface.
3041 */
3042 static const char *uriParameter(const char *zFilename, const char *zParam){
3043   zFilename += sqlite3Strlen30(zFilename) + 1;
3044   while( zFilename[0] ){
3045     int x = strcmp(zFilename, zParam);
3046     zFilename += sqlite3Strlen30(zFilename) + 1;
3047     if( x==0 ) return zFilename;
3048     zFilename += sqlite3Strlen30(zFilename) + 1;
3049   }
3050   return 0;
3051 }
3052 
3053 
3054 
3055 /*
3056 ** This routine does the work of opening a database on behalf of
3057 ** sqlite3_open() and sqlite3_open16(). The database filename "zFilename"
3058 ** is UTF-8 encoded.
3059 */
3060 static int openDatabase(
3061   const char *zFilename, /* Database filename UTF-8 encoded */
3062   sqlite3 **ppDb,        /* OUT: Returned database handle */
3063   unsigned int flags,    /* Operational flags */
3064   const char *zVfs       /* Name of the VFS to use */
3065 ){
3066   sqlite3 *db;                    /* Store allocated handle here */
3067   int rc;                         /* Return code */
3068   int isThreadsafe;               /* True for threadsafe connections */
3069   char *zOpen = 0;                /* Filename argument to pass to BtreeOpen() */
3070   char *zErrMsg = 0;              /* Error message from sqlite3ParseUri() */
3071   int i;                          /* Loop counter */
3072 
3073 #ifdef SQLITE_ENABLE_API_ARMOR
3074   if( ppDb==0 ) return SQLITE_MISUSE_BKPT;
3075 #endif
3076   *ppDb = 0;
3077 #ifndef SQLITE_OMIT_AUTOINIT
3078   rc = sqlite3_initialize();
3079   if( rc ) return rc;
3080 #endif
3081 
3082   if( sqlite3GlobalConfig.bCoreMutex==0 ){
3083     isThreadsafe = 0;
3084   }else if( flags & SQLITE_OPEN_NOMUTEX ){
3085     isThreadsafe = 0;
3086   }else if( flags & SQLITE_OPEN_FULLMUTEX ){
3087     isThreadsafe = 1;
3088   }else{
3089     isThreadsafe = sqlite3GlobalConfig.bFullMutex;
3090   }
3091 
3092   if( flags & SQLITE_OPEN_PRIVATECACHE ){
3093     flags &= ~SQLITE_OPEN_SHAREDCACHE;
3094   }else if( sqlite3GlobalConfig.sharedCacheEnabled ){
3095     flags |= SQLITE_OPEN_SHAREDCACHE;
3096   }
3097 
3098   /* Remove harmful bits from the flags parameter
3099   **
3100   ** The SQLITE_OPEN_NOMUTEX and SQLITE_OPEN_FULLMUTEX flags were
3101   ** dealt with in the previous code block.  Besides these, the only
3102   ** valid input flags for sqlite3_open_v2() are SQLITE_OPEN_READONLY,
3103   ** SQLITE_OPEN_READWRITE, SQLITE_OPEN_CREATE, SQLITE_OPEN_SHAREDCACHE,
3104   ** SQLITE_OPEN_PRIVATECACHE, and some reserved bits.  Silently mask
3105   ** off all other flags.
3106   */
3107   flags &=  ~( SQLITE_OPEN_DELETEONCLOSE |
3108                SQLITE_OPEN_EXCLUSIVE |
3109                SQLITE_OPEN_MAIN_DB |
3110                SQLITE_OPEN_TEMP_DB |
3111                SQLITE_OPEN_TRANSIENT_DB |
3112                SQLITE_OPEN_MAIN_JOURNAL |
3113                SQLITE_OPEN_TEMP_JOURNAL |
3114                SQLITE_OPEN_SUBJOURNAL |
3115                SQLITE_OPEN_SUPER_JOURNAL |
3116                SQLITE_OPEN_NOMUTEX |
3117                SQLITE_OPEN_FULLMUTEX |
3118                SQLITE_OPEN_WAL
3119              );
3120 
3121   /* Allocate the sqlite data structure */
3122   db = sqlite3MallocZero( sizeof(sqlite3) );
3123   if( db==0 ) goto opendb_out;
3124   if( isThreadsafe
3125 #ifdef SQLITE_ENABLE_MULTITHREADED_CHECKS
3126    || sqlite3GlobalConfig.bCoreMutex
3127 #endif
3128   ){
3129     db->mutex = sqlite3MutexAlloc(SQLITE_MUTEX_RECURSIVE);
3130     if( db->mutex==0 ){
3131       sqlite3_free(db);
3132       db = 0;
3133       goto opendb_out;
3134     }
3135     if( isThreadsafe==0 ){
3136       sqlite3MutexWarnOnContention(db->mutex);
3137     }
3138   }
3139   sqlite3_mutex_enter(db->mutex);
3140   db->errMask = 0xff;
3141   db->nDb = 2;
3142   db->magic = SQLITE_MAGIC_BUSY;
3143   db->aDb = db->aDbStatic;
3144   db->lookaside.bDisable = 1;
3145   db->lookaside.sz = 0;
3146 
3147   assert( sizeof(db->aLimit)==sizeof(aHardLimit) );
3148   memcpy(db->aLimit, aHardLimit, sizeof(db->aLimit));
3149   db->aLimit[SQLITE_LIMIT_WORKER_THREADS] = SQLITE_DEFAULT_WORKER_THREADS;
3150   db->autoCommit = 1;
3151   db->nextAutovac = -1;
3152   db->szMmap = sqlite3GlobalConfig.szMmap;
3153   db->nextPagesize = 0;
3154   db->nMaxSorterMmap = 0x7FFFFFFF;
3155   db->flags |= SQLITE_ShortColNames
3156                  | SQLITE_EnableTrigger
3157                  | SQLITE_EnableView
3158                  | SQLITE_CacheSpill
3159 #if !defined(SQLITE_TRUSTED_SCHEMA) || SQLITE_TRUSTED_SCHEMA+0!=0
3160                  | SQLITE_TrustedSchema
3161 #endif
3162 /* The SQLITE_DQS compile-time option determines the default settings
3163 ** for SQLITE_DBCONFIG_DQS_DDL and SQLITE_DBCONFIG_DQS_DML.
3164 **
3165 **    SQLITE_DQS     SQLITE_DBCONFIG_DQS_DDL    SQLITE_DBCONFIG_DQS_DML
3166 **    ----------     -----------------------    -----------------------
3167 **     undefined               on                          on
3168 **         3                   on                          on
3169 **         2                   on                         off
3170 **         1                  off                          on
3171 **         0                  off                         off
3172 **
3173 ** Legacy behavior is 3 (double-quoted string literals are allowed anywhere)
3174 ** and so that is the default.  But developers are encouranged to use
3175 ** -DSQLITE_DQS=0 (best) or -DSQLITE_DQS=1 (second choice) if possible.
3176 */
3177 #if !defined(SQLITE_DQS)
3178 # define SQLITE_DQS 3
3179 #endif
3180 #if (SQLITE_DQS&1)==1
3181                  | SQLITE_DqsDML
3182 #endif
3183 #if (SQLITE_DQS&2)==2
3184                  | SQLITE_DqsDDL
3185 #endif
3186 
3187 #if !defined(SQLITE_DEFAULT_AUTOMATIC_INDEX) || SQLITE_DEFAULT_AUTOMATIC_INDEX
3188                  | SQLITE_AutoIndex
3189 #endif
3190 #if SQLITE_DEFAULT_CKPTFULLFSYNC
3191                  | SQLITE_CkptFullFSync
3192 #endif
3193 #if SQLITE_DEFAULT_FILE_FORMAT<4
3194                  | SQLITE_LegacyFileFmt
3195 #endif
3196 #ifdef SQLITE_ENABLE_LOAD_EXTENSION
3197                  | SQLITE_LoadExtension
3198 #endif
3199 #if SQLITE_DEFAULT_RECURSIVE_TRIGGERS
3200                  | SQLITE_RecTriggers
3201 #endif
3202 #if defined(SQLITE_DEFAULT_FOREIGN_KEYS) && SQLITE_DEFAULT_FOREIGN_KEYS
3203                  | SQLITE_ForeignKeys
3204 #endif
3205 #if defined(SQLITE_REVERSE_UNORDERED_SELECTS)
3206                  | SQLITE_ReverseOrder
3207 #endif
3208 #if defined(SQLITE_ENABLE_OVERSIZE_CELL_CHECK)
3209                  | SQLITE_CellSizeCk
3210 #endif
3211 #if defined(SQLITE_ENABLE_FTS3_TOKENIZER)
3212                  | SQLITE_Fts3Tokenizer
3213 #endif
3214 #if defined(SQLITE_ENABLE_QPSG)
3215                  | SQLITE_EnableQPSG
3216 #endif
3217 #if defined(SQLITE_DEFAULT_DEFENSIVE)
3218                  | SQLITE_Defensive
3219 #endif
3220 #if defined(SQLITE_DEFAULT_LEGACY_ALTER_TABLE)
3221                  | SQLITE_LegacyAlter
3222 #endif
3223       ;
3224   sqlite3HashInit(&db->aCollSeq);
3225 #ifndef SQLITE_OMIT_VIRTUALTABLE
3226   sqlite3HashInit(&db->aModule);
3227 #endif
3228 
3229   /* Add the default collation sequence BINARY. BINARY works for both UTF-8
3230   ** and UTF-16, so add a version for each to avoid any unnecessary
3231   ** conversions. The only error that can occur here is a malloc() failure.
3232   **
3233   ** EVIDENCE-OF: R-52786-44878 SQLite defines three built-in collating
3234   ** functions:
3235   */
3236   createCollation(db, sqlite3StrBINARY, SQLITE_UTF8, 0, binCollFunc, 0);
3237   createCollation(db, sqlite3StrBINARY, SQLITE_UTF16BE, 0, binCollFunc, 0);
3238   createCollation(db, sqlite3StrBINARY, SQLITE_UTF16LE, 0, binCollFunc, 0);
3239   createCollation(db, "NOCASE", SQLITE_UTF8, 0, nocaseCollatingFunc, 0);
3240   createCollation(db, "RTRIM", SQLITE_UTF8, 0, rtrimCollFunc, 0);
3241   if( db->mallocFailed ){
3242     goto opendb_out;
3243   }
3244 
3245   /* Parse the filename/URI argument
3246   **
3247   ** Only allow sensible combinations of bits in the flags argument.
3248   ** Throw an error if any non-sense combination is used.  If we
3249   ** do not block illegal combinations here, it could trigger
3250   ** assert() statements in deeper layers.  Sensible combinations
3251   ** are:
3252   **
3253   **  1:  SQLITE_OPEN_READONLY
3254   **  2:  SQLITE_OPEN_READWRITE
3255   **  6:  SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE
3256   */
3257   db->openFlags = flags;
3258   assert( SQLITE_OPEN_READONLY  == 0x01 );
3259   assert( SQLITE_OPEN_READWRITE == 0x02 );
3260   assert( SQLITE_OPEN_CREATE    == 0x04 );
3261   testcase( (1<<(flags&7))==0x02 ); /* READONLY */
3262   testcase( (1<<(flags&7))==0x04 ); /* READWRITE */
3263   testcase( (1<<(flags&7))==0x40 ); /* READWRITE | CREATE */
3264   if( ((1<<(flags&7)) & 0x46)==0 ){
3265     rc = SQLITE_MISUSE_BKPT;  /* IMP: R-18321-05872 */
3266   }else{
3267     rc = sqlite3ParseUri(zVfs, zFilename, &flags, &db->pVfs, &zOpen, &zErrMsg);
3268   }
3269   if( rc!=SQLITE_OK ){
3270     if( rc==SQLITE_NOMEM ) sqlite3OomFault(db);
3271     sqlite3ErrorWithMsg(db, rc, zErrMsg ? "%s" : 0, zErrMsg);
3272     sqlite3_free(zErrMsg);
3273     goto opendb_out;
3274   }
3275 
3276   /* Open the backend database driver */
3277   rc = sqlite3BtreeOpen(db->pVfs, zOpen, db, &db->aDb[0].pBt, 0,
3278                         flags | SQLITE_OPEN_MAIN_DB);
3279   if( rc!=SQLITE_OK ){
3280     if( rc==SQLITE_IOERR_NOMEM ){
3281       rc = SQLITE_NOMEM_BKPT;
3282     }
3283     sqlite3Error(db, rc);
3284     goto opendb_out;
3285   }
3286   sqlite3BtreeEnter(db->aDb[0].pBt);
3287   db->aDb[0].pSchema = sqlite3SchemaGet(db, db->aDb[0].pBt);
3288   if( !db->mallocFailed ){
3289     sqlite3SetTextEncoding(db, SCHEMA_ENC(db));
3290   }
3291   sqlite3BtreeLeave(db->aDb[0].pBt);
3292   db->aDb[1].pSchema = sqlite3SchemaGet(db, 0);
3293 
3294   /* The default safety_level for the main database is FULL; for the temp
3295   ** database it is OFF. This matches the pager layer defaults.
3296   */
3297   db->aDb[0].zDbSName = "main";
3298   db->aDb[0].safety_level = SQLITE_DEFAULT_SYNCHRONOUS+1;
3299   db->aDb[1].zDbSName = "temp";
3300   db->aDb[1].safety_level = PAGER_SYNCHRONOUS_OFF;
3301 
3302   db->magic = SQLITE_MAGIC_OPEN;
3303   if( db->mallocFailed ){
3304     goto opendb_out;
3305   }
3306 
3307   /* Register all built-in functions, but do not attempt to read the
3308   ** database schema yet. This is delayed until the first time the database
3309   ** is accessed.
3310   */
3311   sqlite3Error(db, SQLITE_OK);
3312   sqlite3RegisterPerConnectionBuiltinFunctions(db);
3313   rc = sqlite3_errcode(db);
3314 
3315 
3316   /* Load compiled-in extensions */
3317   for(i=0; rc==SQLITE_OK && i<ArraySize(sqlite3BuiltinExtensions); i++){
3318     rc = sqlite3BuiltinExtensions[i](db);
3319   }
3320 
3321   /* Load automatic extensions - extensions that have been registered
3322   ** using the sqlite3_automatic_extension() API.
3323   */
3324   if( rc==SQLITE_OK ){
3325     sqlite3AutoLoadExtensions(db);
3326     rc = sqlite3_errcode(db);
3327     if( rc!=SQLITE_OK ){
3328       goto opendb_out;
3329     }
3330   }
3331 
3332 #ifdef SQLITE_ENABLE_INTERNAL_FUNCTIONS
3333   /* Testing use only!!! The -DSQLITE_ENABLE_INTERNAL_FUNCTIONS=1 compile-time
3334   ** option gives access to internal functions by default.
3335   ** Testing use only!!! */
3336   db->mDbFlags |= DBFLAG_InternalFunc;
3337 #endif
3338 
3339   /* -DSQLITE_DEFAULT_LOCKING_MODE=1 makes EXCLUSIVE the default locking
3340   ** mode.  -DSQLITE_DEFAULT_LOCKING_MODE=0 make NORMAL the default locking
3341   ** mode.  Doing nothing at all also makes NORMAL the default.
3342   */
3343 #ifdef SQLITE_DEFAULT_LOCKING_MODE
3344   db->dfltLockMode = SQLITE_DEFAULT_LOCKING_MODE;
3345   sqlite3PagerLockingMode(sqlite3BtreePager(db->aDb[0].pBt),
3346                           SQLITE_DEFAULT_LOCKING_MODE);
3347 #endif
3348 
3349   if( rc ) sqlite3Error(db, rc);
3350 
3351   /* Enable the lookaside-malloc subsystem */
3352   setupLookaside(db, 0, sqlite3GlobalConfig.szLookaside,
3353                         sqlite3GlobalConfig.nLookaside);
3354 
3355   sqlite3_wal_autocheckpoint(db, SQLITE_DEFAULT_WAL_AUTOCHECKPOINT);
3356 
3357 opendb_out:
3358   if( db ){
3359     assert( db->mutex!=0 || isThreadsafe==0
3360            || sqlite3GlobalConfig.bFullMutex==0 );
3361     sqlite3_mutex_leave(db->mutex);
3362   }
3363   rc = sqlite3_errcode(db);
3364   assert( db!=0 || rc==SQLITE_NOMEM );
3365   if( rc==SQLITE_NOMEM ){
3366     sqlite3_close(db);
3367     db = 0;
3368   }else if( rc!=SQLITE_OK ){
3369     db->magic = SQLITE_MAGIC_SICK;
3370   }
3371   *ppDb = db;
3372 #ifdef SQLITE_ENABLE_SQLLOG
3373   if( sqlite3GlobalConfig.xSqllog ){
3374     /* Opening a db handle. Fourth parameter is passed 0. */
3375     void *pArg = sqlite3GlobalConfig.pSqllogArg;
3376     sqlite3GlobalConfig.xSqllog(pArg, db, zFilename, 0);
3377   }
3378 #endif
3379   sqlite3_free_filename(zOpen);
3380   return rc & 0xff;
3381 }
3382 
3383 
3384 /*
3385 ** Open a new database handle.
3386 */
3387 int sqlite3_open(
3388   const char *zFilename,
3389   sqlite3 **ppDb
3390 ){
3391   return openDatabase(zFilename, ppDb,
3392                       SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
3393 }
3394 int sqlite3_open_v2(
3395   const char *filename,   /* Database filename (UTF-8) */
3396   sqlite3 **ppDb,         /* OUT: SQLite db handle */
3397   int flags,              /* Flags */
3398   const char *zVfs        /* Name of VFS module to use */
3399 ){
3400   return openDatabase(filename, ppDb, (unsigned int)flags, zVfs);
3401 }
3402 
3403 #ifndef SQLITE_OMIT_UTF16
3404 /*
3405 ** Open a new database handle.
3406 */
3407 int sqlite3_open16(
3408   const void *zFilename,
3409   sqlite3 **ppDb
3410 ){
3411   char const *zFilename8;   /* zFilename encoded in UTF-8 instead of UTF-16 */
3412   sqlite3_value *pVal;
3413   int rc;
3414 
3415 #ifdef SQLITE_ENABLE_API_ARMOR
3416   if( ppDb==0 ) return SQLITE_MISUSE_BKPT;
3417 #endif
3418   *ppDb = 0;
3419 #ifndef SQLITE_OMIT_AUTOINIT
3420   rc = sqlite3_initialize();
3421   if( rc ) return rc;
3422 #endif
3423   if( zFilename==0 ) zFilename = "\000\000";
3424   pVal = sqlite3ValueNew(0);
3425   sqlite3ValueSetStr(pVal, -1, zFilename, SQLITE_UTF16NATIVE, SQLITE_STATIC);
3426   zFilename8 = sqlite3ValueText(pVal, SQLITE_UTF8);
3427   if( zFilename8 ){
3428     rc = openDatabase(zFilename8, ppDb,
3429                       SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
3430     assert( *ppDb || rc==SQLITE_NOMEM );
3431     if( rc==SQLITE_OK && !DbHasProperty(*ppDb, 0, DB_SchemaLoaded) ){
3432       SCHEMA_ENC(*ppDb) = ENC(*ppDb) = SQLITE_UTF16NATIVE;
3433     }
3434   }else{
3435     rc = SQLITE_NOMEM_BKPT;
3436   }
3437   sqlite3ValueFree(pVal);
3438 
3439   return rc & 0xff;
3440 }
3441 #endif /* SQLITE_OMIT_UTF16 */
3442 
3443 /*
3444 ** Register a new collation sequence with the database handle db.
3445 */
3446 int sqlite3_create_collation(
3447   sqlite3* db,
3448   const char *zName,
3449   int enc,
3450   void* pCtx,
3451   int(*xCompare)(void*,int,const void*,int,const void*)
3452 ){
3453   return sqlite3_create_collation_v2(db, zName, enc, pCtx, xCompare, 0);
3454 }
3455 
3456 /*
3457 ** Register a new collation sequence with the database handle db.
3458 */
3459 int sqlite3_create_collation_v2(
3460   sqlite3* db,
3461   const char *zName,
3462   int enc,
3463   void* pCtx,
3464   int(*xCompare)(void*,int,const void*,int,const void*),
3465   void(*xDel)(void*)
3466 ){
3467   int rc;
3468 
3469 #ifdef SQLITE_ENABLE_API_ARMOR
3470   if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
3471 #endif
3472   sqlite3_mutex_enter(db->mutex);
3473   assert( !db->mallocFailed );
3474   rc = createCollation(db, zName, (u8)enc, pCtx, xCompare, xDel);
3475   rc = sqlite3ApiExit(db, rc);
3476   sqlite3_mutex_leave(db->mutex);
3477   return rc;
3478 }
3479 
3480 #ifndef SQLITE_OMIT_UTF16
3481 /*
3482 ** Register a new collation sequence with the database handle db.
3483 */
3484 int sqlite3_create_collation16(
3485   sqlite3* db,
3486   const void *zName,
3487   int enc,
3488   void* pCtx,
3489   int(*xCompare)(void*,int,const void*,int,const void*)
3490 ){
3491   int rc = SQLITE_OK;
3492   char *zName8;
3493 
3494 #ifdef SQLITE_ENABLE_API_ARMOR
3495   if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
3496 #endif
3497   sqlite3_mutex_enter(db->mutex);
3498   assert( !db->mallocFailed );
3499   zName8 = sqlite3Utf16to8(db, zName, -1, SQLITE_UTF16NATIVE);
3500   if( zName8 ){
3501     rc = createCollation(db, zName8, (u8)enc, pCtx, xCompare, 0);
3502     sqlite3DbFree(db, zName8);
3503   }
3504   rc = sqlite3ApiExit(db, rc);
3505   sqlite3_mutex_leave(db->mutex);
3506   return rc;
3507 }
3508 #endif /* SQLITE_OMIT_UTF16 */
3509 
3510 /*
3511 ** Register a collation sequence factory callback with the database handle
3512 ** db. Replace any previously installed collation sequence factory.
3513 */
3514 int sqlite3_collation_needed(
3515   sqlite3 *db,
3516   void *pCollNeededArg,
3517   void(*xCollNeeded)(void*,sqlite3*,int eTextRep,const char*)
3518 ){
3519 #ifdef SQLITE_ENABLE_API_ARMOR
3520   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3521 #endif
3522   sqlite3_mutex_enter(db->mutex);
3523   db->xCollNeeded = xCollNeeded;
3524   db->xCollNeeded16 = 0;
3525   db->pCollNeededArg = pCollNeededArg;
3526   sqlite3_mutex_leave(db->mutex);
3527   return SQLITE_OK;
3528 }
3529 
3530 #ifndef SQLITE_OMIT_UTF16
3531 /*
3532 ** Register a collation sequence factory callback with the database handle
3533 ** db. Replace any previously installed collation sequence factory.
3534 */
3535 int sqlite3_collation_needed16(
3536   sqlite3 *db,
3537   void *pCollNeededArg,
3538   void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*)
3539 ){
3540 #ifdef SQLITE_ENABLE_API_ARMOR
3541   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3542 #endif
3543   sqlite3_mutex_enter(db->mutex);
3544   db->xCollNeeded = 0;
3545   db->xCollNeeded16 = xCollNeeded16;
3546   db->pCollNeededArg = pCollNeededArg;
3547   sqlite3_mutex_leave(db->mutex);
3548   return SQLITE_OK;
3549 }
3550 #endif /* SQLITE_OMIT_UTF16 */
3551 
3552 #ifndef SQLITE_OMIT_DEPRECATED
3553 /*
3554 ** This function is now an anachronism. It used to be used to recover from a
3555 ** malloc() failure, but SQLite now does this automatically.
3556 */
3557 int sqlite3_global_recover(void){
3558   return SQLITE_OK;
3559 }
3560 #endif
3561 
3562 /*
3563 ** Test to see whether or not the database connection is in autocommit
3564 ** mode.  Return TRUE if it is and FALSE if not.  Autocommit mode is on
3565 ** by default.  Autocommit is disabled by a BEGIN statement and reenabled
3566 ** by the next COMMIT or ROLLBACK.
3567 */
3568 int sqlite3_get_autocommit(sqlite3 *db){
3569 #ifdef SQLITE_ENABLE_API_ARMOR
3570   if( !sqlite3SafetyCheckOk(db) ){
3571     (void)SQLITE_MISUSE_BKPT;
3572     return 0;
3573   }
3574 #endif
3575   return db->autoCommit;
3576 }
3577 
3578 /*
3579 ** The following routines are substitutes for constants SQLITE_CORRUPT,
3580 ** SQLITE_MISUSE, SQLITE_CANTOPEN, SQLITE_NOMEM and possibly other error
3581 ** constants.  They serve two purposes:
3582 **
3583 **   1.  Serve as a convenient place to set a breakpoint in a debugger
3584 **       to detect when version error conditions occurs.
3585 **
3586 **   2.  Invoke sqlite3_log() to provide the source code location where
3587 **       a low-level error is first detected.
3588 */
3589 int sqlite3ReportError(int iErr, int lineno, const char *zType){
3590   sqlite3_log(iErr, "%s at line %d of [%.10s]",
3591               zType, lineno, 20+sqlite3_sourceid());
3592   return iErr;
3593 }
3594 int sqlite3CorruptError(int lineno){
3595   testcase( sqlite3GlobalConfig.xLog!=0 );
3596   return sqlite3ReportError(SQLITE_CORRUPT, lineno, "database corruption");
3597 }
3598 int sqlite3MisuseError(int lineno){
3599   testcase( sqlite3GlobalConfig.xLog!=0 );
3600   return sqlite3ReportError(SQLITE_MISUSE, lineno, "misuse");
3601 }
3602 int sqlite3CantopenError(int lineno){
3603   testcase( sqlite3GlobalConfig.xLog!=0 );
3604   return sqlite3ReportError(SQLITE_CANTOPEN, lineno, "cannot open file");
3605 }
3606 #if defined(SQLITE_DEBUG) || defined(SQLITE_ENABLE_CORRUPT_PGNO)
3607 int sqlite3CorruptPgnoError(int lineno, Pgno pgno){
3608   char zMsg[100];
3609   sqlite3_snprintf(sizeof(zMsg), zMsg, "database corruption page %d", pgno);
3610   testcase( sqlite3GlobalConfig.xLog!=0 );
3611   return sqlite3ReportError(SQLITE_CORRUPT, lineno, zMsg);
3612 }
3613 #endif
3614 #ifdef SQLITE_DEBUG
3615 int sqlite3NomemError(int lineno){
3616   testcase( sqlite3GlobalConfig.xLog!=0 );
3617   return sqlite3ReportError(SQLITE_NOMEM, lineno, "OOM");
3618 }
3619 int sqlite3IoerrnomemError(int lineno){
3620   testcase( sqlite3GlobalConfig.xLog!=0 );
3621   return sqlite3ReportError(SQLITE_IOERR_NOMEM, lineno, "I/O OOM error");
3622 }
3623 #endif
3624 
3625 #ifndef SQLITE_OMIT_DEPRECATED
3626 /*
3627 ** This is a convenience routine that makes sure that all thread-specific
3628 ** data for this thread has been deallocated.
3629 **
3630 ** SQLite no longer uses thread-specific data so this routine is now a
3631 ** no-op.  It is retained for historical compatibility.
3632 */
3633 void sqlite3_thread_cleanup(void){
3634 }
3635 #endif
3636 
3637 /*
3638 ** Return meta information about a specific column of a database table.
3639 ** See comment in sqlite3.h (sqlite.h.in) for details.
3640 */
3641 int sqlite3_table_column_metadata(
3642   sqlite3 *db,                /* Connection handle */
3643   const char *zDbName,        /* Database name or NULL */
3644   const char *zTableName,     /* Table name */
3645   const char *zColumnName,    /* Column name */
3646   char const **pzDataType,    /* OUTPUT: Declared data type */
3647   char const **pzCollSeq,     /* OUTPUT: Collation sequence name */
3648   int *pNotNull,              /* OUTPUT: True if NOT NULL constraint exists */
3649   int *pPrimaryKey,           /* OUTPUT: True if column part of PK */
3650   int *pAutoinc               /* OUTPUT: True if column is auto-increment */
3651 ){
3652   int rc;
3653   char *zErrMsg = 0;
3654   Table *pTab = 0;
3655   Column *pCol = 0;
3656   int iCol = 0;
3657   char const *zDataType = 0;
3658   char const *zCollSeq = 0;
3659   int notnull = 0;
3660   int primarykey = 0;
3661   int autoinc = 0;
3662 
3663 
3664 #ifdef SQLITE_ENABLE_API_ARMOR
3665   if( !sqlite3SafetyCheckOk(db) || zTableName==0 ){
3666     return SQLITE_MISUSE_BKPT;
3667   }
3668 #endif
3669 
3670   /* Ensure the database schema has been loaded */
3671   sqlite3_mutex_enter(db->mutex);
3672   sqlite3BtreeEnterAll(db);
3673   rc = sqlite3Init(db, &zErrMsg);
3674   if( SQLITE_OK!=rc ){
3675     goto error_out;
3676   }
3677 
3678   /* Locate the table in question */
3679   pTab = sqlite3FindTable(db, zTableName, zDbName);
3680   if( !pTab || pTab->pSelect ){
3681     pTab = 0;
3682     goto error_out;
3683   }
3684 
3685   /* Find the column for which info is requested */
3686   if( zColumnName==0 ){
3687     /* Query for existance of table only */
3688   }else{
3689     for(iCol=0; iCol<pTab->nCol; iCol++){
3690       pCol = &pTab->aCol[iCol];
3691       if( 0==sqlite3StrICmp(pCol->zName, zColumnName) ){
3692         break;
3693       }
3694     }
3695     if( iCol==pTab->nCol ){
3696       if( HasRowid(pTab) && sqlite3IsRowid(zColumnName) ){
3697         iCol = pTab->iPKey;
3698         pCol = iCol>=0 ? &pTab->aCol[iCol] : 0;
3699       }else{
3700         pTab = 0;
3701         goto error_out;
3702       }
3703     }
3704   }
3705 
3706   /* The following block stores the meta information that will be returned
3707   ** to the caller in local variables zDataType, zCollSeq, notnull, primarykey
3708   ** and autoinc. At this point there are two possibilities:
3709   **
3710   **     1. The specified column name was rowid", "oid" or "_rowid_"
3711   **        and there is no explicitly declared IPK column.
3712   **
3713   **     2. The table is not a view and the column name identified an
3714   **        explicitly declared column. Copy meta information from *pCol.
3715   */
3716   if( pCol ){
3717     zDataType = sqlite3ColumnType(pCol,0);
3718     zCollSeq = pCol->zColl;
3719     notnull = pCol->notNull!=0;
3720     primarykey  = (pCol->colFlags & COLFLAG_PRIMKEY)!=0;
3721     autoinc = pTab->iPKey==iCol && (pTab->tabFlags & TF_Autoincrement)!=0;
3722   }else{
3723     zDataType = "INTEGER";
3724     primarykey = 1;
3725   }
3726   if( !zCollSeq ){
3727     zCollSeq = sqlite3StrBINARY;
3728   }
3729 
3730 error_out:
3731   sqlite3BtreeLeaveAll(db);
3732 
3733   /* Whether the function call succeeded or failed, set the output parameters
3734   ** to whatever their local counterparts contain. If an error did occur,
3735   ** this has the effect of zeroing all output parameters.
3736   */
3737   if( pzDataType ) *pzDataType = zDataType;
3738   if( pzCollSeq ) *pzCollSeq = zCollSeq;
3739   if( pNotNull ) *pNotNull = notnull;
3740   if( pPrimaryKey ) *pPrimaryKey = primarykey;
3741   if( pAutoinc ) *pAutoinc = autoinc;
3742 
3743   if( SQLITE_OK==rc && !pTab ){
3744     sqlite3DbFree(db, zErrMsg);
3745     zErrMsg = sqlite3MPrintf(db, "no such table column: %s.%s", zTableName,
3746         zColumnName);
3747     rc = SQLITE_ERROR;
3748   }
3749   sqlite3ErrorWithMsg(db, rc, (zErrMsg?"%s":0), zErrMsg);
3750   sqlite3DbFree(db, zErrMsg);
3751   rc = sqlite3ApiExit(db, rc);
3752   sqlite3_mutex_leave(db->mutex);
3753   return rc;
3754 }
3755 
3756 /*
3757 ** Sleep for a little while.  Return the amount of time slept.
3758 */
3759 int sqlite3_sleep(int ms){
3760   sqlite3_vfs *pVfs;
3761   int rc;
3762   pVfs = sqlite3_vfs_find(0);
3763   if( pVfs==0 ) return 0;
3764 
3765   /* This function works in milliseconds, but the underlying OsSleep()
3766   ** API uses microseconds. Hence the 1000's.
3767   */
3768   rc = (sqlite3OsSleep(pVfs, 1000*ms)/1000);
3769   return rc;
3770 }
3771 
3772 /*
3773 ** Enable or disable the extended result codes.
3774 */
3775 int sqlite3_extended_result_codes(sqlite3 *db, int onoff){
3776 #ifdef SQLITE_ENABLE_API_ARMOR
3777   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3778 #endif
3779   sqlite3_mutex_enter(db->mutex);
3780   db->errMask = onoff ? 0xffffffff : 0xff;
3781   sqlite3_mutex_leave(db->mutex);
3782   return SQLITE_OK;
3783 }
3784 
3785 /*
3786 ** Invoke the xFileControl method on a particular database.
3787 */
3788 int sqlite3_file_control(sqlite3 *db, const char *zDbName, int op, void *pArg){
3789   int rc = SQLITE_ERROR;
3790   Btree *pBtree;
3791 
3792 #ifdef SQLITE_ENABLE_API_ARMOR
3793   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3794 #endif
3795   sqlite3_mutex_enter(db->mutex);
3796   pBtree = sqlite3DbNameToBtree(db, zDbName);
3797   if( pBtree ){
3798     Pager *pPager;
3799     sqlite3_file *fd;
3800     sqlite3BtreeEnter(pBtree);
3801     pPager = sqlite3BtreePager(pBtree);
3802     assert( pPager!=0 );
3803     fd = sqlite3PagerFile(pPager);
3804     assert( fd!=0 );
3805     if( op==SQLITE_FCNTL_FILE_POINTER ){
3806       *(sqlite3_file**)pArg = fd;
3807       rc = SQLITE_OK;
3808     }else if( op==SQLITE_FCNTL_VFS_POINTER ){
3809       *(sqlite3_vfs**)pArg = sqlite3PagerVfs(pPager);
3810       rc = SQLITE_OK;
3811     }else if( op==SQLITE_FCNTL_JOURNAL_POINTER ){
3812       *(sqlite3_file**)pArg = sqlite3PagerJrnlFile(pPager);
3813       rc = SQLITE_OK;
3814     }else if( op==SQLITE_FCNTL_DATA_VERSION ){
3815       *(unsigned int*)pArg = sqlite3PagerDataVersion(pPager);
3816       rc = SQLITE_OK;
3817     }else if( op==SQLITE_FCNTL_RESERVE_BYTES ){
3818       int iNew = *(int*)pArg;
3819       *(int*)pArg = sqlite3BtreeGetRequestedReserve(pBtree);
3820       if( iNew>=0 && iNew<=255 ){
3821         sqlite3BtreeSetPageSize(pBtree, 0, iNew, 0);
3822       }
3823       rc = SQLITE_OK;
3824     }else{
3825       rc = sqlite3OsFileControl(fd, op, pArg);
3826     }
3827     sqlite3BtreeLeave(pBtree);
3828   }
3829   sqlite3_mutex_leave(db->mutex);
3830   return rc;
3831 }
3832 
3833 /*
3834 ** Interface to the testing logic.
3835 */
3836 int sqlite3_test_control(int op, ...){
3837   int rc = 0;
3838 #ifdef SQLITE_UNTESTABLE
3839   UNUSED_PARAMETER(op);
3840 #else
3841   va_list ap;
3842   va_start(ap, op);
3843   switch( op ){
3844 
3845     /*
3846     ** Save the current state of the PRNG.
3847     */
3848     case SQLITE_TESTCTRL_PRNG_SAVE: {
3849       sqlite3PrngSaveState();
3850       break;
3851     }
3852 
3853     /*
3854     ** Restore the state of the PRNG to the last state saved using
3855     ** PRNG_SAVE.  If PRNG_SAVE has never before been called, then
3856     ** this verb acts like PRNG_RESET.
3857     */
3858     case SQLITE_TESTCTRL_PRNG_RESTORE: {
3859       sqlite3PrngRestoreState();
3860       break;
3861     }
3862 
3863     /*  sqlite3_test_control(SQLITE_TESTCTRL_PRNG_SEED, int x, sqlite3 *db);
3864     **
3865     ** Control the seed for the pseudo-random number generator (PRNG) that
3866     ** is built into SQLite.  Cases:
3867     **
3868     **    x!=0 && db!=0       Seed the PRNG to the current value of the
3869     **                        schema cookie in the main database for db, or
3870     **                        x if the schema cookie is zero.  This case
3871     **                        is convenient to use with database fuzzers
3872     **                        as it allows the fuzzer some control over the
3873     **                        the PRNG seed.
3874     **
3875     **    x!=0 && db==0       Seed the PRNG to the value of x.
3876     **
3877     **    x==0 && db==0       Revert to default behavior of using the
3878     **                        xRandomness method on the primary VFS.
3879     **
3880     ** This test-control also resets the PRNG so that the new seed will
3881     ** be used for the next call to sqlite3_randomness().
3882     */
3883 #ifndef SQLITE_OMIT_WSD
3884     case SQLITE_TESTCTRL_PRNG_SEED: {
3885       int x = va_arg(ap, int);
3886       int y;
3887       sqlite3 *db = va_arg(ap, sqlite3*);
3888       assert( db==0 || db->aDb[0].pSchema!=0 );
3889       if( db && (y = db->aDb[0].pSchema->schema_cookie)!=0 ){ x = y; }
3890       sqlite3Config.iPrngSeed = x;
3891       sqlite3_randomness(0,0);
3892       break;
3893     }
3894 #endif
3895 
3896     /*
3897     **  sqlite3_test_control(BITVEC_TEST, size, program)
3898     **
3899     ** Run a test against a Bitvec object of size.  The program argument
3900     ** is an array of integers that defines the test.  Return -1 on a
3901     ** memory allocation error, 0 on success, or non-zero for an error.
3902     ** See the sqlite3BitvecBuiltinTest() for additional information.
3903     */
3904     case SQLITE_TESTCTRL_BITVEC_TEST: {
3905       int sz = va_arg(ap, int);
3906       int *aProg = va_arg(ap, int*);
3907       rc = sqlite3BitvecBuiltinTest(sz, aProg);
3908       break;
3909     }
3910 
3911     /*
3912     **  sqlite3_test_control(FAULT_INSTALL, xCallback)
3913     **
3914     ** Arrange to invoke xCallback() whenever sqlite3FaultSim() is called,
3915     ** if xCallback is not NULL.
3916     **
3917     ** As a test of the fault simulator mechanism itself, sqlite3FaultSim(0)
3918     ** is called immediately after installing the new callback and the return
3919     ** value from sqlite3FaultSim(0) becomes the return from
3920     ** sqlite3_test_control().
3921     */
3922     case SQLITE_TESTCTRL_FAULT_INSTALL: {
3923       /* MSVC is picky about pulling func ptrs from va lists.
3924       ** http://support.microsoft.com/kb/47961
3925       ** sqlite3GlobalConfig.xTestCallback = va_arg(ap, int(*)(int));
3926       */
3927       typedef int(*TESTCALLBACKFUNC_t)(int);
3928       sqlite3GlobalConfig.xTestCallback = va_arg(ap, TESTCALLBACKFUNC_t);
3929       rc = sqlite3FaultSim(0);
3930       break;
3931     }
3932 
3933     /*
3934     **  sqlite3_test_control(BENIGN_MALLOC_HOOKS, xBegin, xEnd)
3935     **
3936     ** Register hooks to call to indicate which malloc() failures
3937     ** are benign.
3938     */
3939     case SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS: {
3940       typedef void (*void_function)(void);
3941       void_function xBenignBegin;
3942       void_function xBenignEnd;
3943       xBenignBegin = va_arg(ap, void_function);
3944       xBenignEnd = va_arg(ap, void_function);
3945       sqlite3BenignMallocHooks(xBenignBegin, xBenignEnd);
3946       break;
3947     }
3948 
3949     /*
3950     **  sqlite3_test_control(SQLITE_TESTCTRL_PENDING_BYTE, unsigned int X)
3951     **
3952     ** Set the PENDING byte to the value in the argument, if X>0.
3953     ** Make no changes if X==0.  Return the value of the pending byte
3954     ** as it existing before this routine was called.
3955     **
3956     ** IMPORTANT:  Changing the PENDING byte from 0x40000000 results in
3957     ** an incompatible database file format.  Changing the PENDING byte
3958     ** while any database connection is open results in undefined and
3959     ** deleterious behavior.
3960     */
3961     case SQLITE_TESTCTRL_PENDING_BYTE: {
3962       rc = PENDING_BYTE;
3963 #ifndef SQLITE_OMIT_WSD
3964       {
3965         unsigned int newVal = va_arg(ap, unsigned int);
3966         if( newVal ) sqlite3PendingByte = newVal;
3967       }
3968 #endif
3969       break;
3970     }
3971 
3972     /*
3973     **  sqlite3_test_control(SQLITE_TESTCTRL_ASSERT, int X)
3974     **
3975     ** This action provides a run-time test to see whether or not
3976     ** assert() was enabled at compile-time.  If X is true and assert()
3977     ** is enabled, then the return value is true.  If X is true and
3978     ** assert() is disabled, then the return value is zero.  If X is
3979     ** false and assert() is enabled, then the assertion fires and the
3980     ** process aborts.  If X is false and assert() is disabled, then the
3981     ** return value is zero.
3982     */
3983     case SQLITE_TESTCTRL_ASSERT: {
3984       volatile int x = 0;
3985       assert( /*side-effects-ok*/ (x = va_arg(ap,int))!=0 );
3986       rc = x;
3987       break;
3988     }
3989 
3990 
3991     /*
3992     **  sqlite3_test_control(SQLITE_TESTCTRL_ALWAYS, int X)
3993     **
3994     ** This action provides a run-time test to see how the ALWAYS and
3995     ** NEVER macros were defined at compile-time.
3996     **
3997     ** The return value is ALWAYS(X) if X is true, or 0 if X is false.
3998     **
3999     ** The recommended test is X==2.  If the return value is 2, that means
4000     ** ALWAYS() and NEVER() are both no-op pass-through macros, which is the
4001     ** default setting.  If the return value is 1, then ALWAYS() is either
4002     ** hard-coded to true or else it asserts if its argument is false.
4003     ** The first behavior (hard-coded to true) is the case if
4004     ** SQLITE_TESTCTRL_ASSERT shows that assert() is disabled and the second
4005     ** behavior (assert if the argument to ALWAYS() is false) is the case if
4006     ** SQLITE_TESTCTRL_ASSERT shows that assert() is enabled.
4007     **
4008     ** The run-time test procedure might look something like this:
4009     **
4010     **    if( sqlite3_test_control(SQLITE_TESTCTRL_ALWAYS, 2)==2 ){
4011     **      // ALWAYS() and NEVER() are no-op pass-through macros
4012     **    }else if( sqlite3_test_control(SQLITE_TESTCTRL_ASSERT, 1) ){
4013     **      // ALWAYS(x) asserts that x is true. NEVER(x) asserts x is false.
4014     **    }else{
4015     **      // ALWAYS(x) is a constant 1.  NEVER(x) is a constant 0.
4016     **    }
4017     */
4018     case SQLITE_TESTCTRL_ALWAYS: {
4019       int x = va_arg(ap,int);
4020       rc = x ? ALWAYS(x) : 0;
4021       break;
4022     }
4023 
4024     /*
4025     **   sqlite3_test_control(SQLITE_TESTCTRL_BYTEORDER);
4026     **
4027     ** The integer returned reveals the byte-order of the computer on which
4028     ** SQLite is running:
4029     **
4030     **       1     big-endian,    determined at run-time
4031     **      10     little-endian, determined at run-time
4032     **  432101     big-endian,    determined at compile-time
4033     **  123410     little-endian, determined at compile-time
4034     */
4035     case SQLITE_TESTCTRL_BYTEORDER: {
4036       rc = SQLITE_BYTEORDER*100 + SQLITE_LITTLEENDIAN*10 + SQLITE_BIGENDIAN;
4037       break;
4038     }
4039 
4040     /*  sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS, sqlite3 *db, int N)
4041     **
4042     ** Enable or disable various optimizations for testing purposes.  The
4043     ** argument N is a bitmask of optimizations to be disabled.  For normal
4044     ** operation N should be 0.  The idea is that a test program (like the
4045     ** SQL Logic Test or SLT test module) can run the same SQL multiple times
4046     ** with various optimizations disabled to verify that the same answer
4047     ** is obtained in every case.
4048     */
4049     case SQLITE_TESTCTRL_OPTIMIZATIONS: {
4050       sqlite3 *db = va_arg(ap, sqlite3*);
4051       db->dbOptFlags = (u16)(va_arg(ap, int) & 0xffff);
4052       break;
4053     }
4054 
4055     /*   sqlite3_test_control(SQLITE_TESTCTRL_LOCALTIME_FAULT, int onoff);
4056     **
4057     ** If parameter onoff is non-zero, subsequent calls to localtime()
4058     ** and its variants fail. If onoff is zero, undo this setting.
4059     */
4060     case SQLITE_TESTCTRL_LOCALTIME_FAULT: {
4061       sqlite3GlobalConfig.bLocaltimeFault = va_arg(ap, int);
4062       break;
4063     }
4064 
4065     /*   sqlite3_test_control(SQLITE_TESTCTRL_INTERNAL_FUNCTIONS, sqlite3*);
4066     **
4067     ** Toggle the ability to use internal functions on or off for
4068     ** the database connection given in the argument.
4069     */
4070     case SQLITE_TESTCTRL_INTERNAL_FUNCTIONS: {
4071       sqlite3 *db = va_arg(ap, sqlite3*);
4072       db->mDbFlags ^= DBFLAG_InternalFunc;
4073       break;
4074     }
4075 
4076     /*   sqlite3_test_control(SQLITE_TESTCTRL_NEVER_CORRUPT, int);
4077     **
4078     ** Set or clear a flag that indicates that the database file is always well-
4079     ** formed and never corrupt.  This flag is clear by default, indicating that
4080     ** database files might have arbitrary corruption.  Setting the flag during
4081     ** testing causes certain assert() statements in the code to be activated
4082     ** that demonstrat invariants on well-formed database files.
4083     */
4084     case SQLITE_TESTCTRL_NEVER_CORRUPT: {
4085       sqlite3GlobalConfig.neverCorrupt = va_arg(ap, int);
4086       break;
4087     }
4088 
4089     /*   sqlite3_test_control(SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS, int);
4090     **
4091     ** Set or clear a flag that causes SQLite to verify that type, name,
4092     ** and tbl_name fields of the sqlite_schema table.  This is normally
4093     ** on, but it is sometimes useful to turn it off for testing.
4094     */
4095     case SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS: {
4096       sqlite3GlobalConfig.bExtraSchemaChecks = va_arg(ap, int);
4097       break;
4098     }
4099 
4100     /* Set the threshold at which OP_Once counters reset back to zero.
4101     ** By default this is 0x7ffffffe (over 2 billion), but that value is
4102     ** too big to test in a reasonable amount of time, so this control is
4103     ** provided to set a small and easily reachable reset value.
4104     */
4105     case SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD: {
4106       sqlite3GlobalConfig.iOnceResetThreshold = va_arg(ap, int);
4107       break;
4108     }
4109 
4110     /*   sqlite3_test_control(SQLITE_TESTCTRL_VDBE_COVERAGE, xCallback, ptr);
4111     **
4112     ** Set the VDBE coverage callback function to xCallback with context
4113     ** pointer ptr.
4114     */
4115     case SQLITE_TESTCTRL_VDBE_COVERAGE: {
4116 #ifdef SQLITE_VDBE_COVERAGE
4117       typedef void (*branch_callback)(void*,unsigned int,
4118                                       unsigned char,unsigned char);
4119       sqlite3GlobalConfig.xVdbeBranch = va_arg(ap,branch_callback);
4120       sqlite3GlobalConfig.pVdbeBranchArg = va_arg(ap,void*);
4121 #endif
4122       break;
4123     }
4124 
4125     /*   sqlite3_test_control(SQLITE_TESTCTRL_SORTER_MMAP, db, nMax); */
4126     case SQLITE_TESTCTRL_SORTER_MMAP: {
4127       sqlite3 *db = va_arg(ap, sqlite3*);
4128       db->nMaxSorterMmap = va_arg(ap, int);
4129       break;
4130     }
4131 
4132     /*   sqlite3_test_control(SQLITE_TESTCTRL_ISINIT);
4133     **
4134     ** Return SQLITE_OK if SQLite has been initialized and SQLITE_ERROR if
4135     ** not.
4136     */
4137     case SQLITE_TESTCTRL_ISINIT: {
4138       if( sqlite3GlobalConfig.isInit==0 ) rc = SQLITE_ERROR;
4139       break;
4140     }
4141 
4142     /*  sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, db, dbName, onOff, tnum);
4143     **
4144     ** This test control is used to create imposter tables.  "db" is a pointer
4145     ** to the database connection.  dbName is the database name (ex: "main" or
4146     ** "temp") which will receive the imposter.  "onOff" turns imposter mode on
4147     ** or off.  "tnum" is the root page of the b-tree to which the imposter
4148     ** table should connect.
4149     **
4150     ** Enable imposter mode only when the schema has already been parsed.  Then
4151     ** run a single CREATE TABLE statement to construct the imposter table in
4152     ** the parsed schema.  Then turn imposter mode back off again.
4153     **
4154     ** If onOff==0 and tnum>0 then reset the schema for all databases, causing
4155     ** the schema to be reparsed the next time it is needed.  This has the
4156     ** effect of erasing all imposter tables.
4157     */
4158     case SQLITE_TESTCTRL_IMPOSTER: {
4159       sqlite3 *db = va_arg(ap, sqlite3*);
4160       sqlite3_mutex_enter(db->mutex);
4161       db->init.iDb = sqlite3FindDbName(db, va_arg(ap,const char*));
4162       db->init.busy = db->init.imposterTable = va_arg(ap,int);
4163       db->init.newTnum = va_arg(ap,int);
4164       if( db->init.busy==0 && db->init.newTnum>0 ){
4165         sqlite3ResetAllSchemasOfConnection(db);
4166       }
4167       sqlite3_mutex_leave(db->mutex);
4168       break;
4169     }
4170 
4171 #if defined(YYCOVERAGE)
4172     /*  sqlite3_test_control(SQLITE_TESTCTRL_PARSER_COVERAGE, FILE *out)
4173     **
4174     ** This test control (only available when SQLite is compiled with
4175     ** -DYYCOVERAGE) writes a report onto "out" that shows all
4176     ** state/lookahead combinations in the parser state machine
4177     ** which are never exercised.  If any state is missed, make the
4178     ** return code SQLITE_ERROR.
4179     */
4180     case SQLITE_TESTCTRL_PARSER_COVERAGE: {
4181       FILE *out = va_arg(ap, FILE*);
4182       if( sqlite3ParserCoverage(out) ) rc = SQLITE_ERROR;
4183       break;
4184     }
4185 #endif /* defined(YYCOVERAGE) */
4186 
4187     /*  sqlite3_test_control(SQLITE_TESTCTRL_RESULT_INTREAL, sqlite3_context*);
4188     **
4189     ** This test-control causes the most recent sqlite3_result_int64() value
4190     ** to be interpreted as a MEM_IntReal instead of as an MEM_Int.  Normally,
4191     ** MEM_IntReal values only arise during an INSERT operation of integer
4192     ** values into a REAL column, so they can be challenging to test.  This
4193     ** test-control enables us to write an intreal() SQL function that can
4194     ** inject an intreal() value at arbitrary places in an SQL statement,
4195     ** for testing purposes.
4196     */
4197     case SQLITE_TESTCTRL_RESULT_INTREAL: {
4198       sqlite3_context *pCtx = va_arg(ap, sqlite3_context*);
4199       sqlite3ResultIntReal(pCtx);
4200       break;
4201     }
4202   }
4203   va_end(ap);
4204 #endif /* SQLITE_UNTESTABLE */
4205   return rc;
4206 }
4207 
4208 /*
4209 ** The Pager stores the Database filename, Journal filename, and WAL filename
4210 ** consecutively in memory, in that order.  The database filename is prefixed
4211 ** by four zero bytes.  Locate the start of the database filename by searching
4212 ** backwards for the first byte following four consecutive zero bytes.
4213 **
4214 ** This only works if the filename passed in was obtained from the Pager.
4215 */
4216 static const char *databaseName(const char *zName){
4217   while( zName[-1]!=0 || zName[-2]!=0 || zName[-3]!=0 || zName[-4]!=0 ){
4218     zName--;
4219   }
4220   return zName;
4221 }
4222 
4223 /*
4224 ** Append text z[] to the end of p[].  Return a pointer to the first
4225 ** character after then zero terminator on the new text in p[].
4226 */
4227 static char *appendText(char *p, const char *z){
4228   size_t n = strlen(z);
4229   memcpy(p, z, n+1);
4230   return p+n+1;
4231 }
4232 
4233 /*
4234 ** Allocate memory to hold names for a database, journal file, WAL file,
4235 ** and query parameters.  The pointer returned is valid for use by
4236 ** sqlite3_filename_database() and sqlite3_uri_parameter() and related
4237 ** functions.
4238 **
4239 ** Memory layout must be compatible with that generated by the pager
4240 ** and expected by sqlite3_uri_parameter() and databaseName().
4241 */
4242 char *sqlite3_create_filename(
4243   const char *zDatabase,
4244   const char *zJournal,
4245   const char *zWal,
4246   int nParam,
4247   const char **azParam
4248 ){
4249   sqlite3_int64 nByte;
4250   int i;
4251   char *pResult, *p;
4252   nByte = strlen(zDatabase) + strlen(zJournal) + strlen(zWal) + 10;
4253   for(i=0; i<nParam*2; i++){
4254     nByte += strlen(azParam[i])+1;
4255   }
4256   pResult = p = sqlite3_malloc64( nByte );
4257   if( p==0 ) return 0;
4258   memset(p, 0, 4);
4259   p += 4;
4260   p = appendText(p, zDatabase);
4261   for(i=0; i<nParam*2; i++){
4262     p = appendText(p, azParam[i]);
4263   }
4264   *(p++) = 0;
4265   p = appendText(p, zJournal);
4266   p = appendText(p, zWal);
4267   *(p++) = 0;
4268   *(p++) = 0;
4269   assert( (sqlite3_int64)(p - pResult)==nByte );
4270   return pResult + 4;
4271 }
4272 
4273 /*
4274 ** Free memory obtained from sqlite3_create_filename().  It is a severe
4275 ** error to call this routine with any parameter other than a pointer
4276 ** previously obtained from sqlite3_create_filename() or a NULL pointer.
4277 */
4278 void sqlite3_free_filename(char *p){
4279   if( p==0 ) return;
4280   p = (char*)databaseName(p);
4281   sqlite3_free(p - 4);
4282 }
4283 
4284 
4285 /*
4286 ** This is a utility routine, useful to VFS implementations, that checks
4287 ** to see if a database file was a URI that contained a specific query
4288 ** parameter, and if so obtains the value of the query parameter.
4289 **
4290 ** The zFilename argument is the filename pointer passed into the xOpen()
4291 ** method of a VFS implementation.  The zParam argument is the name of the
4292 ** query parameter we seek.  This routine returns the value of the zParam
4293 ** parameter if it exists.  If the parameter does not exist, this routine
4294 ** returns a NULL pointer.
4295 */
4296 const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam){
4297   if( zFilename==0 || zParam==0 ) return 0;
4298   zFilename = databaseName(zFilename);
4299   return uriParameter(zFilename, zParam);
4300 }
4301 
4302 /*
4303 ** Return a pointer to the name of Nth query parameter of the filename.
4304 */
4305 const char *sqlite3_uri_key(const char *zFilename, int N){
4306   if( zFilename==0 || N<0 ) return 0;
4307   zFilename = databaseName(zFilename);
4308   zFilename += sqlite3Strlen30(zFilename) + 1;
4309   while( zFilename[0] && (N--)>0 ){
4310     zFilename += sqlite3Strlen30(zFilename) + 1;
4311     zFilename += sqlite3Strlen30(zFilename) + 1;
4312   }
4313   return zFilename[0] ? zFilename : 0;
4314 }
4315 
4316 /*
4317 ** Return a boolean value for a query parameter.
4318 */
4319 int sqlite3_uri_boolean(const char *zFilename, const char *zParam, int bDflt){
4320   const char *z = sqlite3_uri_parameter(zFilename, zParam);
4321   bDflt = bDflt!=0;
4322   return z ? sqlite3GetBoolean(z, bDflt) : bDflt;
4323 }
4324 
4325 /*
4326 ** Return a 64-bit integer value for a query parameter.
4327 */
4328 sqlite3_int64 sqlite3_uri_int64(
4329   const char *zFilename,    /* Filename as passed to xOpen */
4330   const char *zParam,       /* URI parameter sought */
4331   sqlite3_int64 bDflt       /* return if parameter is missing */
4332 ){
4333   const char *z = sqlite3_uri_parameter(zFilename, zParam);
4334   sqlite3_int64 v;
4335   if( z && sqlite3DecOrHexToI64(z, &v)==0 ){
4336     bDflt = v;
4337   }
4338   return bDflt;
4339 }
4340 
4341 /*
4342 ** Translate a filename that was handed to a VFS routine into the corresponding
4343 ** database, journal, or WAL file.
4344 **
4345 ** It is an error to pass this routine a filename string that was not
4346 ** passed into the VFS from the SQLite core.  Doing so is similar to
4347 ** passing free() a pointer that was not obtained from malloc() - it is
4348 ** an error that we cannot easily detect but that will likely cause memory
4349 ** corruption.
4350 */
4351 const char *sqlite3_filename_database(const char *zFilename){
4352   return databaseName(zFilename);
4353 }
4354 const char *sqlite3_filename_journal(const char *zFilename){
4355   zFilename = databaseName(zFilename);
4356   zFilename += sqlite3Strlen30(zFilename) + 1;
4357   while( zFilename[0] ){
4358     zFilename += sqlite3Strlen30(zFilename) + 1;
4359     zFilename += sqlite3Strlen30(zFilename) + 1;
4360   }
4361   return zFilename + 1;
4362 }
4363 const char *sqlite3_filename_wal(const char *zFilename){
4364 #ifdef SQLITE_OMIT_WAL
4365   return 0;
4366 #else
4367   zFilename = sqlite3_filename_journal(zFilename);
4368   zFilename += sqlite3Strlen30(zFilename) + 1;
4369   return zFilename;
4370 #endif
4371 }
4372 
4373 /*
4374 ** Return the Btree pointer identified by zDbName.  Return NULL if not found.
4375 */
4376 Btree *sqlite3DbNameToBtree(sqlite3 *db, const char *zDbName){
4377   int iDb = zDbName ? sqlite3FindDbName(db, zDbName) : 0;
4378   return iDb<0 ? 0 : db->aDb[iDb].pBt;
4379 }
4380 
4381 /*
4382 ** Return the filename of the database associated with a database
4383 ** connection.
4384 */
4385 const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName){
4386   Btree *pBt;
4387 #ifdef SQLITE_ENABLE_API_ARMOR
4388   if( !sqlite3SafetyCheckOk(db) ){
4389     (void)SQLITE_MISUSE_BKPT;
4390     return 0;
4391   }
4392 #endif
4393   pBt = sqlite3DbNameToBtree(db, zDbName);
4394   return pBt ? sqlite3BtreeGetFilename(pBt) : 0;
4395 }
4396 
4397 /*
4398 ** Return 1 if database is read-only or 0 if read/write.  Return -1 if
4399 ** no such database exists.
4400 */
4401 int sqlite3_db_readonly(sqlite3 *db, const char *zDbName){
4402   Btree *pBt;
4403 #ifdef SQLITE_ENABLE_API_ARMOR
4404   if( !sqlite3SafetyCheckOk(db) ){
4405     (void)SQLITE_MISUSE_BKPT;
4406     return -1;
4407   }
4408 #endif
4409   pBt = sqlite3DbNameToBtree(db, zDbName);
4410   return pBt ? sqlite3BtreeIsReadonly(pBt) : -1;
4411 }
4412 
4413 #ifdef SQLITE_ENABLE_SNAPSHOT
4414 /*
4415 ** Obtain a snapshot handle for the snapshot of database zDb currently
4416 ** being read by handle db.
4417 */
4418 int sqlite3_snapshot_get(
4419   sqlite3 *db,
4420   const char *zDb,
4421   sqlite3_snapshot **ppSnapshot
4422 ){
4423   int rc = SQLITE_ERROR;
4424 #ifndef SQLITE_OMIT_WAL
4425 
4426 #ifdef SQLITE_ENABLE_API_ARMOR
4427   if( !sqlite3SafetyCheckOk(db) ){
4428     return SQLITE_MISUSE_BKPT;
4429   }
4430 #endif
4431   sqlite3_mutex_enter(db->mutex);
4432 
4433   if( db->autoCommit==0 ){
4434     int iDb = sqlite3FindDbName(db, zDb);
4435     if( iDb==0 || iDb>1 ){
4436       Btree *pBt = db->aDb[iDb].pBt;
4437       if( 0==sqlite3BtreeIsInTrans(pBt) ){
4438         rc = sqlite3BtreeBeginTrans(pBt, 0, 0);
4439         if( rc==SQLITE_OK ){
4440           rc = sqlite3PagerSnapshotGet(sqlite3BtreePager(pBt), ppSnapshot);
4441         }
4442       }
4443     }
4444   }
4445 
4446   sqlite3_mutex_leave(db->mutex);
4447 #endif   /* SQLITE_OMIT_WAL */
4448   return rc;
4449 }
4450 
4451 /*
4452 ** Open a read-transaction on the snapshot idendified by pSnapshot.
4453 */
4454 int sqlite3_snapshot_open(
4455   sqlite3 *db,
4456   const char *zDb,
4457   sqlite3_snapshot *pSnapshot
4458 ){
4459   int rc = SQLITE_ERROR;
4460 #ifndef SQLITE_OMIT_WAL
4461 
4462 #ifdef SQLITE_ENABLE_API_ARMOR
4463   if( !sqlite3SafetyCheckOk(db) ){
4464     return SQLITE_MISUSE_BKPT;
4465   }
4466 #endif
4467   sqlite3_mutex_enter(db->mutex);
4468   if( db->autoCommit==0 ){
4469     int iDb;
4470     iDb = sqlite3FindDbName(db, zDb);
4471     if( iDb==0 || iDb>1 ){
4472       Btree *pBt = db->aDb[iDb].pBt;
4473       if( sqlite3BtreeIsInTrans(pBt)==0 ){
4474         Pager *pPager = sqlite3BtreePager(pBt);
4475         int bUnlock = 0;
4476         if( sqlite3BtreeIsInReadTrans(pBt) ){
4477           if( db->nVdbeActive==0 ){
4478             rc = sqlite3PagerSnapshotCheck(pPager, pSnapshot);
4479             if( rc==SQLITE_OK ){
4480               bUnlock = 1;
4481               rc = sqlite3BtreeCommit(pBt);
4482             }
4483           }
4484         }else{
4485           rc = SQLITE_OK;
4486         }
4487         if( rc==SQLITE_OK ){
4488           rc = sqlite3PagerSnapshotOpen(pPager, pSnapshot);
4489         }
4490         if( rc==SQLITE_OK ){
4491           rc = sqlite3BtreeBeginTrans(pBt, 0, 0);
4492           sqlite3PagerSnapshotOpen(pPager, 0);
4493         }
4494         if( bUnlock ){
4495           sqlite3PagerSnapshotUnlock(pPager);
4496         }
4497       }
4498     }
4499   }
4500 
4501   sqlite3_mutex_leave(db->mutex);
4502 #endif   /* SQLITE_OMIT_WAL */
4503   return rc;
4504 }
4505 
4506 /*
4507 ** Recover as many snapshots as possible from the wal file associated with
4508 ** schema zDb of database db.
4509 */
4510 int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb){
4511   int rc = SQLITE_ERROR;
4512   int iDb;
4513 #ifndef SQLITE_OMIT_WAL
4514 
4515 #ifdef SQLITE_ENABLE_API_ARMOR
4516   if( !sqlite3SafetyCheckOk(db) ){
4517     return SQLITE_MISUSE_BKPT;
4518   }
4519 #endif
4520 
4521   sqlite3_mutex_enter(db->mutex);
4522   iDb = sqlite3FindDbName(db, zDb);
4523   if( iDb==0 || iDb>1 ){
4524     Btree *pBt = db->aDb[iDb].pBt;
4525     if( 0==sqlite3BtreeIsInReadTrans(pBt) ){
4526       rc = sqlite3BtreeBeginTrans(pBt, 0, 0);
4527       if( rc==SQLITE_OK ){
4528         rc = sqlite3PagerSnapshotRecover(sqlite3BtreePager(pBt));
4529         sqlite3BtreeCommit(pBt);
4530       }
4531     }
4532   }
4533   sqlite3_mutex_leave(db->mutex);
4534 #endif   /* SQLITE_OMIT_WAL */
4535   return rc;
4536 }
4537 
4538 /*
4539 ** Free a snapshot handle obtained from sqlite3_snapshot_get().
4540 */
4541 void sqlite3_snapshot_free(sqlite3_snapshot *pSnapshot){
4542   sqlite3_free(pSnapshot);
4543 }
4544 #endif /* SQLITE_ENABLE_SNAPSHOT */
4545 
4546 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
4547 /*
4548 ** Given the name of a compile-time option, return true if that option
4549 ** was used and false if not.
4550 **
4551 ** The name can optionally begin with "SQLITE_" but the "SQLITE_" prefix
4552 ** is not required for a match.
4553 */
4554 int sqlite3_compileoption_used(const char *zOptName){
4555   int i, n;
4556   int nOpt;
4557   const char **azCompileOpt;
4558 
4559 #if SQLITE_ENABLE_API_ARMOR
4560   if( zOptName==0 ){
4561     (void)SQLITE_MISUSE_BKPT;
4562     return 0;
4563   }
4564 #endif
4565 
4566   azCompileOpt = sqlite3CompileOptions(&nOpt);
4567 
4568   if( sqlite3StrNICmp(zOptName, "SQLITE_", 7)==0 ) zOptName += 7;
4569   n = sqlite3Strlen30(zOptName);
4570 
4571   /* Since nOpt is normally in single digits, a linear search is
4572   ** adequate. No need for a binary search. */
4573   for(i=0; i<nOpt; i++){
4574     if( sqlite3StrNICmp(zOptName, azCompileOpt[i], n)==0
4575      && sqlite3IsIdChar((unsigned char)azCompileOpt[i][n])==0
4576     ){
4577       return 1;
4578     }
4579   }
4580   return 0;
4581 }
4582 
4583 /*
4584 ** Return the N-th compile-time option string.  If N is out of range,
4585 ** return a NULL pointer.
4586 */
4587 const char *sqlite3_compileoption_get(int N){
4588   int nOpt;
4589   const char **azCompileOpt;
4590   azCompileOpt = sqlite3CompileOptions(&nOpt);
4591   if( N>=0 && N<nOpt ){
4592     return azCompileOpt[N];
4593   }
4594   return 0;
4595 }
4596 #endif /* SQLITE_OMIT_COMPILEOPTION_DIAGS */
4597