xref: /sqlite-3.40.0/src/main.c (revision 77ea2230)
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 #ifndef SQLITE_OMIT_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 #ifndef SQLITE_OMIT_DESERIALIZE
724     case SQLITE_CONFIG_MEMDB_MAXSIZE: {
725       sqlite3GlobalConfig.mxMemdbSize = va_arg(ap, sqlite3_int64);
726       break;
727     }
728 #endif /* SQLITE_OMIT_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 && sqlite3BtreeTxnState(pBt)==SQLITE_TXN_WRITE ){
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 sqlite3_int64 sqlite3_changes64(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 int sqlite3_changes(sqlite3 *db){
1099   return (int)sqlite3_changes64(db);
1100 }
1101 
1102 /*
1103 ** Return the number of changes since the database handle was opened.
1104 */
1105 sqlite3_int64 sqlite3_total_changes64(sqlite3 *db){
1106 #ifdef SQLITE_ENABLE_API_ARMOR
1107   if( !sqlite3SafetyCheckOk(db) ){
1108     (void)SQLITE_MISUSE_BKPT;
1109     return 0;
1110   }
1111 #endif
1112   return db->nTotalChange;
1113 }
1114 int sqlite3_total_changes(sqlite3 *db){
1115   return (int)sqlite3_total_changes64(db);
1116 }
1117 
1118 /*
1119 ** Close all open savepoints. This function only manipulates fields of the
1120 ** database handle object, it does not close any savepoints that may be open
1121 ** at the b-tree/pager level.
1122 */
1123 void sqlite3CloseSavepoints(sqlite3 *db){
1124   while( db->pSavepoint ){
1125     Savepoint *pTmp = db->pSavepoint;
1126     db->pSavepoint = pTmp->pNext;
1127     sqlite3DbFree(db, pTmp);
1128   }
1129   db->nSavepoint = 0;
1130   db->nStatement = 0;
1131   db->isTransactionSavepoint = 0;
1132 }
1133 
1134 /*
1135 ** Invoke the destructor function associated with FuncDef p, if any. Except,
1136 ** if this is not the last copy of the function, do not invoke it. Multiple
1137 ** copies of a single function are created when create_function() is called
1138 ** with SQLITE_ANY as the encoding.
1139 */
1140 static void functionDestroy(sqlite3 *db, FuncDef *p){
1141   FuncDestructor *pDestructor = p->u.pDestructor;
1142   if( pDestructor ){
1143     pDestructor->nRef--;
1144     if( pDestructor->nRef==0 ){
1145       pDestructor->xDestroy(pDestructor->pUserData);
1146       sqlite3DbFree(db, pDestructor);
1147     }
1148   }
1149 }
1150 
1151 /*
1152 ** Disconnect all sqlite3_vtab objects that belong to database connection
1153 ** db. This is called when db is being closed.
1154 */
1155 static void disconnectAllVtab(sqlite3 *db){
1156 #ifndef SQLITE_OMIT_VIRTUALTABLE
1157   int i;
1158   HashElem *p;
1159   sqlite3BtreeEnterAll(db);
1160   for(i=0; i<db->nDb; i++){
1161     Schema *pSchema = db->aDb[i].pSchema;
1162     if( pSchema ){
1163       for(p=sqliteHashFirst(&pSchema->tblHash); p; p=sqliteHashNext(p)){
1164         Table *pTab = (Table *)sqliteHashData(p);
1165         if( IsVirtual(pTab) ) sqlite3VtabDisconnect(db, pTab);
1166       }
1167     }
1168   }
1169   for(p=sqliteHashFirst(&db->aModule); p; p=sqliteHashNext(p)){
1170     Module *pMod = (Module *)sqliteHashData(p);
1171     if( pMod->pEpoTab ){
1172       sqlite3VtabDisconnect(db, pMod->pEpoTab);
1173     }
1174   }
1175   sqlite3VtabUnlockList(db);
1176   sqlite3BtreeLeaveAll(db);
1177 #else
1178   UNUSED_PARAMETER(db);
1179 #endif
1180 }
1181 
1182 /*
1183 ** Return TRUE if database connection db has unfinalized prepared
1184 ** statements or unfinished sqlite3_backup objects.
1185 */
1186 static int connectionIsBusy(sqlite3 *db){
1187   int j;
1188   assert( sqlite3_mutex_held(db->mutex) );
1189   if( db->pVdbe ) return 1;
1190   for(j=0; j<db->nDb; j++){
1191     Btree *pBt = db->aDb[j].pBt;
1192     if( pBt && sqlite3BtreeIsInBackup(pBt) ) return 1;
1193   }
1194   return 0;
1195 }
1196 
1197 /*
1198 ** Close an existing SQLite database
1199 */
1200 static int sqlite3Close(sqlite3 *db, int forceZombie){
1201   if( !db ){
1202     /* EVIDENCE-OF: R-63257-11740 Calling sqlite3_close() or
1203     ** sqlite3_close_v2() with a NULL pointer argument is a harmless no-op. */
1204     return SQLITE_OK;
1205   }
1206   if( !sqlite3SafetyCheckSickOrOk(db) ){
1207     return SQLITE_MISUSE_BKPT;
1208   }
1209   sqlite3_mutex_enter(db->mutex);
1210   if( db->mTrace & SQLITE_TRACE_CLOSE ){
1211     db->trace.xV2(SQLITE_TRACE_CLOSE, db->pTraceArg, db, 0);
1212   }
1213 
1214   /* Force xDisconnect calls on all virtual tables */
1215   disconnectAllVtab(db);
1216 
1217   /* If a transaction is open, the disconnectAllVtab() call above
1218   ** will not have called the xDisconnect() method on any virtual
1219   ** tables in the db->aVTrans[] array. The following sqlite3VtabRollback()
1220   ** call will do so. We need to do this before the check for active
1221   ** SQL statements below, as the v-table implementation may be storing
1222   ** some prepared statements internally.
1223   */
1224   sqlite3VtabRollback(db);
1225 
1226   /* Legacy behavior (sqlite3_close() behavior) is to return
1227   ** SQLITE_BUSY if the connection can not be closed immediately.
1228   */
1229   if( !forceZombie && connectionIsBusy(db) ){
1230     sqlite3ErrorWithMsg(db, SQLITE_BUSY, "unable to close due to unfinalized "
1231        "statements or unfinished backups");
1232     sqlite3_mutex_leave(db->mutex);
1233     return SQLITE_BUSY;
1234   }
1235 
1236 #ifdef SQLITE_ENABLE_SQLLOG
1237   if( sqlite3GlobalConfig.xSqllog ){
1238     /* Closing the handle. Fourth parameter is passed the value 2. */
1239     sqlite3GlobalConfig.xSqllog(sqlite3GlobalConfig.pSqllogArg, db, 0, 2);
1240   }
1241 #endif
1242 
1243   /* Convert the connection into a zombie and then close it.
1244   */
1245   db->magic = SQLITE_MAGIC_ZOMBIE;
1246   sqlite3LeaveMutexAndCloseZombie(db);
1247   return SQLITE_OK;
1248 }
1249 
1250 /*
1251 ** Return the transaction state for a single databse, or the maximum
1252 ** transaction state over all attached databases if zSchema is null.
1253 */
1254 int sqlite3_txn_state(sqlite3 *db, const char *zSchema){
1255   int iDb, nDb;
1256   int iTxn = -1;
1257 #ifdef SQLITE_ENABLE_API_ARMOR
1258   if( !sqlite3SafetyCheckOk(db) ){
1259     (void)SQLITE_MISUSE_BKPT;
1260     return -1;
1261   }
1262 #endif
1263   sqlite3_mutex_enter(db->mutex);
1264   if( zSchema ){
1265     nDb = iDb = sqlite3FindDbName(db, zSchema);
1266     if( iDb<0 ) nDb--;
1267   }else{
1268     iDb = 0;
1269     nDb = db->nDb-1;
1270   }
1271   for(; iDb<=nDb; iDb++){
1272     Btree *pBt = db->aDb[iDb].pBt;
1273     int x = pBt!=0 ? sqlite3BtreeTxnState(pBt) : SQLITE_TXN_NONE;
1274     if( x>iTxn ) iTxn = x;
1275   }
1276   sqlite3_mutex_leave(db->mutex);
1277   return iTxn;
1278 }
1279 
1280 /*
1281 ** Two variations on the public interface for closing a database
1282 ** connection. The sqlite3_close() version returns SQLITE_BUSY and
1283 ** leaves the connection open if there are unfinalized prepared
1284 ** statements or unfinished sqlite3_backups.  The sqlite3_close_v2()
1285 ** version forces the connection to become a zombie if there are
1286 ** unclosed resources, and arranges for deallocation when the last
1287 ** prepare statement or sqlite3_backup closes.
1288 */
1289 int sqlite3_close(sqlite3 *db){ return sqlite3Close(db,0); }
1290 int sqlite3_close_v2(sqlite3 *db){ return sqlite3Close(db,1); }
1291 
1292 
1293 /*
1294 ** Close the mutex on database connection db.
1295 **
1296 ** Furthermore, if database connection db is a zombie (meaning that there
1297 ** has been a prior call to sqlite3_close(db) or sqlite3_close_v2(db)) and
1298 ** every sqlite3_stmt has now been finalized and every sqlite3_backup has
1299 ** finished, then free all resources.
1300 */
1301 void sqlite3LeaveMutexAndCloseZombie(sqlite3 *db){
1302   HashElem *i;                    /* Hash table iterator */
1303   int j;
1304 
1305   /* If there are outstanding sqlite3_stmt or sqlite3_backup objects
1306   ** or if the connection has not yet been closed by sqlite3_close_v2(),
1307   ** then just leave the mutex and return.
1308   */
1309   if( db->magic!=SQLITE_MAGIC_ZOMBIE || connectionIsBusy(db) ){
1310     sqlite3_mutex_leave(db->mutex);
1311     return;
1312   }
1313 
1314   /* If we reach this point, it means that the database connection has
1315   ** closed all sqlite3_stmt and sqlite3_backup objects and has been
1316   ** passed to sqlite3_close (meaning that it is a zombie).  Therefore,
1317   ** go ahead and free all resources.
1318   */
1319 
1320   /* If a transaction is open, roll it back. This also ensures that if
1321   ** any database schemas have been modified by an uncommitted transaction
1322   ** they are reset. And that the required b-tree mutex is held to make
1323   ** the pager rollback and schema reset an atomic operation. */
1324   sqlite3RollbackAll(db, SQLITE_OK);
1325 
1326   /* Free any outstanding Savepoint structures. */
1327   sqlite3CloseSavepoints(db);
1328 
1329   /* Close all database connections */
1330   for(j=0; j<db->nDb; j++){
1331     struct Db *pDb = &db->aDb[j];
1332     if( pDb->pBt ){
1333       sqlite3BtreeClose(pDb->pBt);
1334       pDb->pBt = 0;
1335       if( j!=1 ){
1336         pDb->pSchema = 0;
1337       }
1338     }
1339   }
1340   /* Clear the TEMP schema separately and last */
1341   if( db->aDb[1].pSchema ){
1342     sqlite3SchemaClear(db->aDb[1].pSchema);
1343   }
1344   sqlite3VtabUnlockList(db);
1345 
1346   /* Free up the array of auxiliary databases */
1347   sqlite3CollapseDatabaseArray(db);
1348   assert( db->nDb<=2 );
1349   assert( db->aDb==db->aDbStatic );
1350 
1351   /* Tell the code in notify.c that the connection no longer holds any
1352   ** locks and does not require any further unlock-notify callbacks.
1353   */
1354   sqlite3ConnectionClosed(db);
1355 
1356   for(i=sqliteHashFirst(&db->aFunc); i; i=sqliteHashNext(i)){
1357     FuncDef *pNext, *p;
1358     p = sqliteHashData(i);
1359     do{
1360       functionDestroy(db, p);
1361       pNext = p->pNext;
1362       sqlite3DbFree(db, p);
1363       p = pNext;
1364     }while( p );
1365   }
1366   sqlite3HashClear(&db->aFunc);
1367   for(i=sqliteHashFirst(&db->aCollSeq); i; i=sqliteHashNext(i)){
1368     CollSeq *pColl = (CollSeq *)sqliteHashData(i);
1369     /* Invoke any destructors registered for collation sequence user data. */
1370     for(j=0; j<3; j++){
1371       if( pColl[j].xDel ){
1372         pColl[j].xDel(pColl[j].pUser);
1373       }
1374     }
1375     sqlite3DbFree(db, pColl);
1376   }
1377   sqlite3HashClear(&db->aCollSeq);
1378 #ifndef SQLITE_OMIT_VIRTUALTABLE
1379   for(i=sqliteHashFirst(&db->aModule); i; i=sqliteHashNext(i)){
1380     Module *pMod = (Module *)sqliteHashData(i);
1381     sqlite3VtabEponymousTableClear(db, pMod);
1382     sqlite3VtabModuleUnref(db, pMod);
1383   }
1384   sqlite3HashClear(&db->aModule);
1385 #endif
1386 
1387   sqlite3Error(db, SQLITE_OK); /* Deallocates any cached error strings. */
1388   sqlite3ValueFree(db->pErr);
1389   sqlite3CloseExtensions(db);
1390 #if SQLITE_USER_AUTHENTICATION
1391   sqlite3_free(db->auth.zAuthUser);
1392   sqlite3_free(db->auth.zAuthPW);
1393 #endif
1394 
1395   db->magic = SQLITE_MAGIC_ERROR;
1396 
1397   /* The temp-database schema is allocated differently from the other schema
1398   ** objects (using sqliteMalloc() directly, instead of sqlite3BtreeSchema()).
1399   ** So it needs to be freed here. Todo: Why not roll the temp schema into
1400   ** the same sqliteMalloc() as the one that allocates the database
1401   ** structure?
1402   */
1403   sqlite3DbFree(db, db->aDb[1].pSchema);
1404   sqlite3_mutex_leave(db->mutex);
1405   db->magic = SQLITE_MAGIC_CLOSED;
1406   sqlite3_mutex_free(db->mutex);
1407   assert( sqlite3LookasideUsed(db,0)==0 );
1408   if( db->lookaside.bMalloced ){
1409     sqlite3_free(db->lookaside.pStart);
1410   }
1411   sqlite3_free(db);
1412 }
1413 
1414 /*
1415 ** Rollback all database files.  If tripCode is not SQLITE_OK, then
1416 ** any write cursors are invalidated ("tripped" - as in "tripping a circuit
1417 ** breaker") and made to return tripCode if there are any further
1418 ** attempts to use that cursor.  Read cursors remain open and valid
1419 ** but are "saved" in case the table pages are moved around.
1420 */
1421 void sqlite3RollbackAll(sqlite3 *db, int tripCode){
1422   int i;
1423   int inTrans = 0;
1424   int schemaChange;
1425   assert( sqlite3_mutex_held(db->mutex) );
1426   sqlite3BeginBenignMalloc();
1427 
1428   /* Obtain all b-tree mutexes before making any calls to BtreeRollback().
1429   ** This is important in case the transaction being rolled back has
1430   ** modified the database schema. If the b-tree mutexes are not taken
1431   ** here, then another shared-cache connection might sneak in between
1432   ** the database rollback and schema reset, which can cause false
1433   ** corruption reports in some cases.  */
1434   sqlite3BtreeEnterAll(db);
1435   schemaChange = (db->mDbFlags & DBFLAG_SchemaChange)!=0 && db->init.busy==0;
1436 
1437   for(i=0; i<db->nDb; i++){
1438     Btree *p = db->aDb[i].pBt;
1439     if( p ){
1440       if( sqlite3BtreeTxnState(p)==SQLITE_TXN_WRITE ){
1441         inTrans = 1;
1442       }
1443       sqlite3BtreeRollback(p, tripCode, !schemaChange);
1444     }
1445   }
1446   sqlite3VtabRollback(db);
1447   sqlite3EndBenignMalloc();
1448 
1449   if( schemaChange ){
1450     sqlite3ExpirePreparedStatements(db, 0);
1451     sqlite3ResetAllSchemasOfConnection(db);
1452   }
1453   sqlite3BtreeLeaveAll(db);
1454 
1455   /* Any deferred constraint violations have now been resolved. */
1456   db->nDeferredCons = 0;
1457   db->nDeferredImmCons = 0;
1458   db->flags &= ~(u64)SQLITE_DeferFKs;
1459 
1460   /* If one has been configured, invoke the rollback-hook callback */
1461   if( db->xRollbackCallback && (inTrans || !db->autoCommit) ){
1462     db->xRollbackCallback(db->pRollbackArg);
1463   }
1464 }
1465 
1466 /*
1467 ** Return a static string containing the name corresponding to the error code
1468 ** specified in the argument.
1469 */
1470 #if defined(SQLITE_NEED_ERR_NAME)
1471 const char *sqlite3ErrName(int rc){
1472   const char *zName = 0;
1473   int i, origRc = rc;
1474   for(i=0; i<2 && zName==0; i++, rc &= 0xff){
1475     switch( rc ){
1476       case SQLITE_OK:                 zName = "SQLITE_OK";                break;
1477       case SQLITE_ERROR:              zName = "SQLITE_ERROR";             break;
1478       case SQLITE_ERROR_SNAPSHOT:     zName = "SQLITE_ERROR_SNAPSHOT";    break;
1479       case SQLITE_INTERNAL:           zName = "SQLITE_INTERNAL";          break;
1480       case SQLITE_PERM:               zName = "SQLITE_PERM";              break;
1481       case SQLITE_ABORT:              zName = "SQLITE_ABORT";             break;
1482       case SQLITE_ABORT_ROLLBACK:     zName = "SQLITE_ABORT_ROLLBACK";    break;
1483       case SQLITE_BUSY:               zName = "SQLITE_BUSY";              break;
1484       case SQLITE_BUSY_RECOVERY:      zName = "SQLITE_BUSY_RECOVERY";     break;
1485       case SQLITE_BUSY_SNAPSHOT:      zName = "SQLITE_BUSY_SNAPSHOT";     break;
1486       case SQLITE_LOCKED:             zName = "SQLITE_LOCKED";            break;
1487       case SQLITE_LOCKED_SHAREDCACHE: zName = "SQLITE_LOCKED_SHAREDCACHE";break;
1488       case SQLITE_NOMEM:              zName = "SQLITE_NOMEM";             break;
1489       case SQLITE_READONLY:           zName = "SQLITE_READONLY";          break;
1490       case SQLITE_READONLY_RECOVERY:  zName = "SQLITE_READONLY_RECOVERY"; break;
1491       case SQLITE_READONLY_CANTINIT:  zName = "SQLITE_READONLY_CANTINIT"; break;
1492       case SQLITE_READONLY_ROLLBACK:  zName = "SQLITE_READONLY_ROLLBACK"; break;
1493       case SQLITE_READONLY_DBMOVED:   zName = "SQLITE_READONLY_DBMOVED";  break;
1494       case SQLITE_READONLY_DIRECTORY: zName = "SQLITE_READONLY_DIRECTORY";break;
1495       case SQLITE_INTERRUPT:          zName = "SQLITE_INTERRUPT";         break;
1496       case SQLITE_IOERR:              zName = "SQLITE_IOERR";             break;
1497       case SQLITE_IOERR_READ:         zName = "SQLITE_IOERR_READ";        break;
1498       case SQLITE_IOERR_SHORT_READ:   zName = "SQLITE_IOERR_SHORT_READ";  break;
1499       case SQLITE_IOERR_WRITE:        zName = "SQLITE_IOERR_WRITE";       break;
1500       case SQLITE_IOERR_FSYNC:        zName = "SQLITE_IOERR_FSYNC";       break;
1501       case SQLITE_IOERR_DIR_FSYNC:    zName = "SQLITE_IOERR_DIR_FSYNC";   break;
1502       case SQLITE_IOERR_TRUNCATE:     zName = "SQLITE_IOERR_TRUNCATE";    break;
1503       case SQLITE_IOERR_FSTAT:        zName = "SQLITE_IOERR_FSTAT";       break;
1504       case SQLITE_IOERR_UNLOCK:       zName = "SQLITE_IOERR_UNLOCK";      break;
1505       case SQLITE_IOERR_RDLOCK:       zName = "SQLITE_IOERR_RDLOCK";      break;
1506       case SQLITE_IOERR_DELETE:       zName = "SQLITE_IOERR_DELETE";      break;
1507       case SQLITE_IOERR_NOMEM:        zName = "SQLITE_IOERR_NOMEM";       break;
1508       case SQLITE_IOERR_ACCESS:       zName = "SQLITE_IOERR_ACCESS";      break;
1509       case SQLITE_IOERR_CHECKRESERVEDLOCK:
1510                                 zName = "SQLITE_IOERR_CHECKRESERVEDLOCK"; break;
1511       case SQLITE_IOERR_LOCK:         zName = "SQLITE_IOERR_LOCK";        break;
1512       case SQLITE_IOERR_CLOSE:        zName = "SQLITE_IOERR_CLOSE";       break;
1513       case SQLITE_IOERR_DIR_CLOSE:    zName = "SQLITE_IOERR_DIR_CLOSE";   break;
1514       case SQLITE_IOERR_SHMOPEN:      zName = "SQLITE_IOERR_SHMOPEN";     break;
1515       case SQLITE_IOERR_SHMSIZE:      zName = "SQLITE_IOERR_SHMSIZE";     break;
1516       case SQLITE_IOERR_SHMLOCK:      zName = "SQLITE_IOERR_SHMLOCK";     break;
1517       case SQLITE_IOERR_SHMMAP:       zName = "SQLITE_IOERR_SHMMAP";      break;
1518       case SQLITE_IOERR_SEEK:         zName = "SQLITE_IOERR_SEEK";        break;
1519       case SQLITE_IOERR_DELETE_NOENT: zName = "SQLITE_IOERR_DELETE_NOENT";break;
1520       case SQLITE_IOERR_MMAP:         zName = "SQLITE_IOERR_MMAP";        break;
1521       case SQLITE_IOERR_GETTEMPPATH:  zName = "SQLITE_IOERR_GETTEMPPATH"; break;
1522       case SQLITE_IOERR_CONVPATH:     zName = "SQLITE_IOERR_CONVPATH";    break;
1523       case SQLITE_CORRUPT:            zName = "SQLITE_CORRUPT";           break;
1524       case SQLITE_CORRUPT_VTAB:       zName = "SQLITE_CORRUPT_VTAB";      break;
1525       case SQLITE_NOTFOUND:           zName = "SQLITE_NOTFOUND";          break;
1526       case SQLITE_FULL:               zName = "SQLITE_FULL";              break;
1527       case SQLITE_CANTOPEN:           zName = "SQLITE_CANTOPEN";          break;
1528       case SQLITE_CANTOPEN_NOTEMPDIR: zName = "SQLITE_CANTOPEN_NOTEMPDIR";break;
1529       case SQLITE_CANTOPEN_ISDIR:     zName = "SQLITE_CANTOPEN_ISDIR";    break;
1530       case SQLITE_CANTOPEN_FULLPATH:  zName = "SQLITE_CANTOPEN_FULLPATH"; break;
1531       case SQLITE_CANTOPEN_CONVPATH:  zName = "SQLITE_CANTOPEN_CONVPATH"; break;
1532       case SQLITE_CANTOPEN_SYMLINK:   zName = "SQLITE_CANTOPEN_SYMLINK";  break;
1533       case SQLITE_PROTOCOL:           zName = "SQLITE_PROTOCOL";          break;
1534       case SQLITE_EMPTY:              zName = "SQLITE_EMPTY";             break;
1535       case SQLITE_SCHEMA:             zName = "SQLITE_SCHEMA";            break;
1536       case SQLITE_TOOBIG:             zName = "SQLITE_TOOBIG";            break;
1537       case SQLITE_CONSTRAINT:         zName = "SQLITE_CONSTRAINT";        break;
1538       case SQLITE_CONSTRAINT_UNIQUE:  zName = "SQLITE_CONSTRAINT_UNIQUE"; break;
1539       case SQLITE_CONSTRAINT_TRIGGER: zName = "SQLITE_CONSTRAINT_TRIGGER";break;
1540       case SQLITE_CONSTRAINT_FOREIGNKEY:
1541                                 zName = "SQLITE_CONSTRAINT_FOREIGNKEY";   break;
1542       case SQLITE_CONSTRAINT_CHECK:   zName = "SQLITE_CONSTRAINT_CHECK";  break;
1543       case SQLITE_CONSTRAINT_PRIMARYKEY:
1544                                 zName = "SQLITE_CONSTRAINT_PRIMARYKEY";   break;
1545       case SQLITE_CONSTRAINT_NOTNULL: zName = "SQLITE_CONSTRAINT_NOTNULL";break;
1546       case SQLITE_CONSTRAINT_COMMITHOOK:
1547                                 zName = "SQLITE_CONSTRAINT_COMMITHOOK";   break;
1548       case SQLITE_CONSTRAINT_VTAB:    zName = "SQLITE_CONSTRAINT_VTAB";   break;
1549       case SQLITE_CONSTRAINT_FUNCTION:
1550                                 zName = "SQLITE_CONSTRAINT_FUNCTION";     break;
1551       case SQLITE_CONSTRAINT_ROWID:   zName = "SQLITE_CONSTRAINT_ROWID";  break;
1552       case SQLITE_MISMATCH:           zName = "SQLITE_MISMATCH";          break;
1553       case SQLITE_MISUSE:             zName = "SQLITE_MISUSE";            break;
1554       case SQLITE_NOLFS:              zName = "SQLITE_NOLFS";             break;
1555       case SQLITE_AUTH:               zName = "SQLITE_AUTH";              break;
1556       case SQLITE_FORMAT:             zName = "SQLITE_FORMAT";            break;
1557       case SQLITE_RANGE:              zName = "SQLITE_RANGE";             break;
1558       case SQLITE_NOTADB:             zName = "SQLITE_NOTADB";            break;
1559       case SQLITE_ROW:                zName = "SQLITE_ROW";               break;
1560       case SQLITE_NOTICE:             zName = "SQLITE_NOTICE";            break;
1561       case SQLITE_NOTICE_RECOVER_WAL: zName = "SQLITE_NOTICE_RECOVER_WAL";break;
1562       case SQLITE_NOTICE_RECOVER_ROLLBACK:
1563                                 zName = "SQLITE_NOTICE_RECOVER_ROLLBACK"; break;
1564       case SQLITE_WARNING:            zName = "SQLITE_WARNING";           break;
1565       case SQLITE_WARNING_AUTOINDEX:  zName = "SQLITE_WARNING_AUTOINDEX"; break;
1566       case SQLITE_DONE:               zName = "SQLITE_DONE";              break;
1567     }
1568   }
1569   if( zName==0 ){
1570     static char zBuf[50];
1571     sqlite3_snprintf(sizeof(zBuf), zBuf, "SQLITE_UNKNOWN(%d)", origRc);
1572     zName = zBuf;
1573   }
1574   return zName;
1575 }
1576 #endif
1577 
1578 /*
1579 ** Return a static string that describes the kind of error specified in the
1580 ** argument.
1581 */
1582 const char *sqlite3ErrStr(int rc){
1583   static const char* const aMsg[] = {
1584     /* SQLITE_OK          */ "not an error",
1585     /* SQLITE_ERROR       */ "SQL logic error",
1586     /* SQLITE_INTERNAL    */ 0,
1587     /* SQLITE_PERM        */ "access permission denied",
1588     /* SQLITE_ABORT       */ "query aborted",
1589     /* SQLITE_BUSY        */ "database is locked",
1590     /* SQLITE_LOCKED      */ "database table is locked",
1591     /* SQLITE_NOMEM       */ "out of memory",
1592     /* SQLITE_READONLY    */ "attempt to write a readonly database",
1593     /* SQLITE_INTERRUPT   */ "interrupted",
1594     /* SQLITE_IOERR       */ "disk I/O error",
1595     /* SQLITE_CORRUPT     */ "database disk image is malformed",
1596     /* SQLITE_NOTFOUND    */ "unknown operation",
1597     /* SQLITE_FULL        */ "database or disk is full",
1598     /* SQLITE_CANTOPEN    */ "unable to open database file",
1599     /* SQLITE_PROTOCOL    */ "locking protocol",
1600     /* SQLITE_EMPTY       */ 0,
1601     /* SQLITE_SCHEMA      */ "database schema has changed",
1602     /* SQLITE_TOOBIG      */ "string or blob too big",
1603     /* SQLITE_CONSTRAINT  */ "constraint failed",
1604     /* SQLITE_MISMATCH    */ "datatype mismatch",
1605     /* SQLITE_MISUSE      */ "bad parameter or other API misuse",
1606 #ifdef SQLITE_DISABLE_LFS
1607     /* SQLITE_NOLFS       */ "large file support is disabled",
1608 #else
1609     /* SQLITE_NOLFS       */ 0,
1610 #endif
1611     /* SQLITE_AUTH        */ "authorization denied",
1612     /* SQLITE_FORMAT      */ 0,
1613     /* SQLITE_RANGE       */ "column index out of range",
1614     /* SQLITE_NOTADB      */ "file is not a database",
1615     /* SQLITE_NOTICE      */ "notification message",
1616     /* SQLITE_WARNING     */ "warning message",
1617   };
1618   const char *zErr = "unknown error";
1619   switch( rc ){
1620     case SQLITE_ABORT_ROLLBACK: {
1621       zErr = "abort due to ROLLBACK";
1622       break;
1623     }
1624     case SQLITE_ROW: {
1625       zErr = "another row available";
1626       break;
1627     }
1628     case SQLITE_DONE: {
1629       zErr = "no more rows available";
1630       break;
1631     }
1632     default: {
1633       rc &= 0xff;
1634       if( ALWAYS(rc>=0) && rc<ArraySize(aMsg) && aMsg[rc]!=0 ){
1635         zErr = aMsg[rc];
1636       }
1637       break;
1638     }
1639   }
1640   return zErr;
1641 }
1642 
1643 /*
1644 ** This routine implements a busy callback that sleeps and tries
1645 ** again until a timeout value is reached.  The timeout value is
1646 ** an integer number of milliseconds passed in as the first
1647 ** argument.
1648 **
1649 ** Return non-zero to retry the lock.  Return zero to stop trying
1650 ** and cause SQLite to return SQLITE_BUSY.
1651 */
1652 static int sqliteDefaultBusyCallback(
1653   void *ptr,               /* Database connection */
1654   int count                /* Number of times table has been busy */
1655 ){
1656 #if SQLITE_OS_WIN || HAVE_USLEEP
1657   /* This case is for systems that have support for sleeping for fractions of
1658   ** a second.  Examples:  All windows systems, unix systems with usleep() */
1659   static const u8 delays[] =
1660      { 1, 2, 5, 10, 15, 20, 25, 25,  25,  50,  50, 100 };
1661   static const u8 totals[] =
1662      { 0, 1, 3,  8, 18, 33, 53, 78, 103, 128, 178, 228 };
1663 # define NDELAY ArraySize(delays)
1664   sqlite3 *db = (sqlite3 *)ptr;
1665   int tmout = db->busyTimeout;
1666   int delay, prior;
1667 
1668   assert( count>=0 );
1669   if( count < NDELAY ){
1670     delay = delays[count];
1671     prior = totals[count];
1672   }else{
1673     delay = delays[NDELAY-1];
1674     prior = totals[NDELAY-1] + delay*(count-(NDELAY-1));
1675   }
1676   if( prior + delay > tmout ){
1677     delay = tmout - prior;
1678     if( delay<=0 ) return 0;
1679   }
1680   sqlite3OsSleep(db->pVfs, delay*1000);
1681   return 1;
1682 #else
1683   /* This case for unix systems that lack usleep() support.  Sleeping
1684   ** must be done in increments of whole seconds */
1685   sqlite3 *db = (sqlite3 *)ptr;
1686   int tmout = ((sqlite3 *)ptr)->busyTimeout;
1687   if( (count+1)*1000 > tmout ){
1688     return 0;
1689   }
1690   sqlite3OsSleep(db->pVfs, 1000000);
1691   return 1;
1692 #endif
1693 }
1694 
1695 /*
1696 ** Invoke the given busy handler.
1697 **
1698 ** This routine is called when an operation failed to acquire a
1699 ** lock on VFS file pFile.
1700 **
1701 ** If this routine returns non-zero, the lock is retried.  If it
1702 ** returns 0, the operation aborts with an SQLITE_BUSY error.
1703 */
1704 int sqlite3InvokeBusyHandler(BusyHandler *p){
1705   int rc;
1706   if( p->xBusyHandler==0 || p->nBusy<0 ) return 0;
1707   rc = p->xBusyHandler(p->pBusyArg, p->nBusy);
1708   if( rc==0 ){
1709     p->nBusy = -1;
1710   }else{
1711     p->nBusy++;
1712   }
1713   return rc;
1714 }
1715 
1716 /*
1717 ** This routine sets the busy callback for an Sqlite database to the
1718 ** given callback function with the given argument.
1719 */
1720 int sqlite3_busy_handler(
1721   sqlite3 *db,
1722   int (*xBusy)(void*,int),
1723   void *pArg
1724 ){
1725 #ifdef SQLITE_ENABLE_API_ARMOR
1726   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
1727 #endif
1728   sqlite3_mutex_enter(db->mutex);
1729   db->busyHandler.xBusyHandler = xBusy;
1730   db->busyHandler.pBusyArg = pArg;
1731   db->busyHandler.nBusy = 0;
1732   db->busyTimeout = 0;
1733   sqlite3_mutex_leave(db->mutex);
1734   return SQLITE_OK;
1735 }
1736 
1737 #ifndef SQLITE_OMIT_PROGRESS_CALLBACK
1738 /*
1739 ** This routine sets the progress callback for an Sqlite database to the
1740 ** given callback function with the given argument. The progress callback will
1741 ** be invoked every nOps opcodes.
1742 */
1743 void sqlite3_progress_handler(
1744   sqlite3 *db,
1745   int nOps,
1746   int (*xProgress)(void*),
1747   void *pArg
1748 ){
1749 #ifdef SQLITE_ENABLE_API_ARMOR
1750   if( !sqlite3SafetyCheckOk(db) ){
1751     (void)SQLITE_MISUSE_BKPT;
1752     return;
1753   }
1754 #endif
1755   sqlite3_mutex_enter(db->mutex);
1756   if( nOps>0 ){
1757     db->xProgress = xProgress;
1758     db->nProgressOps = (unsigned)nOps;
1759     db->pProgressArg = pArg;
1760   }else{
1761     db->xProgress = 0;
1762     db->nProgressOps = 0;
1763     db->pProgressArg = 0;
1764   }
1765   sqlite3_mutex_leave(db->mutex);
1766 }
1767 #endif
1768 
1769 
1770 /*
1771 ** This routine installs a default busy handler that waits for the
1772 ** specified number of milliseconds before returning 0.
1773 */
1774 int sqlite3_busy_timeout(sqlite3 *db, int ms){
1775 #ifdef SQLITE_ENABLE_API_ARMOR
1776   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
1777 #endif
1778   if( ms>0 ){
1779     sqlite3_busy_handler(db, (int(*)(void*,int))sqliteDefaultBusyCallback,
1780                              (void*)db);
1781     db->busyTimeout = ms;
1782   }else{
1783     sqlite3_busy_handler(db, 0, 0);
1784   }
1785   return SQLITE_OK;
1786 }
1787 
1788 /*
1789 ** Cause any pending operation to stop at its earliest opportunity.
1790 */
1791 void sqlite3_interrupt(sqlite3 *db){
1792 #ifdef SQLITE_ENABLE_API_ARMOR
1793   if( !sqlite3SafetyCheckOk(db) && (db==0 || db->magic!=SQLITE_MAGIC_ZOMBIE) ){
1794     (void)SQLITE_MISUSE_BKPT;
1795     return;
1796   }
1797 #endif
1798   AtomicStore(&db->u1.isInterrupted, 1);
1799 }
1800 
1801 
1802 /*
1803 ** This function is exactly the same as sqlite3_create_function(), except
1804 ** that it is designed to be called by internal code. The difference is
1805 ** that if a malloc() fails in sqlite3_create_function(), an error code
1806 ** is returned and the mallocFailed flag cleared.
1807 */
1808 int sqlite3CreateFunc(
1809   sqlite3 *db,
1810   const char *zFunctionName,
1811   int nArg,
1812   int enc,
1813   void *pUserData,
1814   void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
1815   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
1816   void (*xFinal)(sqlite3_context*),
1817   void (*xValue)(sqlite3_context*),
1818   void (*xInverse)(sqlite3_context*,int,sqlite3_value **),
1819   FuncDestructor *pDestructor
1820 ){
1821   FuncDef *p;
1822   int nName;
1823   int extraFlags;
1824 
1825   assert( sqlite3_mutex_held(db->mutex) );
1826   assert( xValue==0 || xSFunc==0 );
1827   if( zFunctionName==0                /* Must have a valid name */
1828    || (xSFunc!=0 && xFinal!=0)        /* Not both xSFunc and xFinal */
1829    || ((xFinal==0)!=(xStep==0))       /* Both or neither of xFinal and xStep */
1830    || ((xValue==0)!=(xInverse==0))    /* Both or neither of xValue, xInverse */
1831    || (nArg<-1 || nArg>SQLITE_MAX_FUNCTION_ARG)
1832    || (255<(nName = sqlite3Strlen30( zFunctionName)))
1833   ){
1834     return SQLITE_MISUSE_BKPT;
1835   }
1836 
1837   assert( SQLITE_FUNC_CONSTANT==SQLITE_DETERMINISTIC );
1838   assert( SQLITE_FUNC_DIRECT==SQLITE_DIRECTONLY );
1839   extraFlags = enc &  (SQLITE_DETERMINISTIC|SQLITE_DIRECTONLY|
1840                        SQLITE_SUBTYPE|SQLITE_INNOCUOUS);
1841   enc &= (SQLITE_FUNC_ENCMASK|SQLITE_ANY);
1842 
1843   /* The SQLITE_INNOCUOUS flag is the same bit as SQLITE_FUNC_UNSAFE.  But
1844   ** the meaning is inverted.  So flip the bit. */
1845   assert( SQLITE_FUNC_UNSAFE==SQLITE_INNOCUOUS );
1846   extraFlags ^= SQLITE_FUNC_UNSAFE;
1847 
1848 
1849 #ifndef SQLITE_OMIT_UTF16
1850   /* If SQLITE_UTF16 is specified as the encoding type, transform this
1851   ** to one of SQLITE_UTF16LE or SQLITE_UTF16BE using the
1852   ** SQLITE_UTF16NATIVE macro. SQLITE_UTF16 is not used internally.
1853   **
1854   ** If SQLITE_ANY is specified, add three versions of the function
1855   ** to the hash table.
1856   */
1857   if( enc==SQLITE_UTF16 ){
1858     enc = SQLITE_UTF16NATIVE;
1859   }else if( enc==SQLITE_ANY ){
1860     int rc;
1861     rc = sqlite3CreateFunc(db, zFunctionName, nArg,
1862          (SQLITE_UTF8|extraFlags)^SQLITE_FUNC_UNSAFE,
1863          pUserData, xSFunc, xStep, xFinal, xValue, xInverse, pDestructor);
1864     if( rc==SQLITE_OK ){
1865       rc = sqlite3CreateFunc(db, zFunctionName, nArg,
1866            (SQLITE_UTF16LE|extraFlags)^SQLITE_FUNC_UNSAFE,
1867            pUserData, xSFunc, xStep, xFinal, xValue, xInverse, pDestructor);
1868     }
1869     if( rc!=SQLITE_OK ){
1870       return rc;
1871     }
1872     enc = SQLITE_UTF16BE;
1873   }
1874 #else
1875   enc = SQLITE_UTF8;
1876 #endif
1877 
1878   /* Check if an existing function is being overridden or deleted. If so,
1879   ** and there are active VMs, then return SQLITE_BUSY. If a function
1880   ** is being overridden/deleted but there are no active VMs, allow the
1881   ** operation to continue but invalidate all precompiled statements.
1882   */
1883   p = sqlite3FindFunction(db, zFunctionName, nArg, (u8)enc, 0);
1884   if( p && (p->funcFlags & SQLITE_FUNC_ENCMASK)==(u32)enc && p->nArg==nArg ){
1885     if( db->nVdbeActive ){
1886       sqlite3ErrorWithMsg(db, SQLITE_BUSY,
1887         "unable to delete/modify user-function due to active statements");
1888       assert( !db->mallocFailed );
1889       return SQLITE_BUSY;
1890     }else{
1891       sqlite3ExpirePreparedStatements(db, 0);
1892     }
1893   }else if( xSFunc==0 && xFinal==0 ){
1894     /* Trying to delete a function that does not exist.  This is a no-op.
1895     ** https://sqlite.org/forum/forumpost/726219164b */
1896     return SQLITE_OK;
1897   }
1898 
1899   p = sqlite3FindFunction(db, zFunctionName, nArg, (u8)enc, 1);
1900   assert(p || db->mallocFailed);
1901   if( !p ){
1902     return SQLITE_NOMEM_BKPT;
1903   }
1904 
1905   /* If an older version of the function with a configured destructor is
1906   ** being replaced invoke the destructor function here. */
1907   functionDestroy(db, p);
1908 
1909   if( pDestructor ){
1910     pDestructor->nRef++;
1911   }
1912   p->u.pDestructor = pDestructor;
1913   p->funcFlags = (p->funcFlags & SQLITE_FUNC_ENCMASK) | extraFlags;
1914   testcase( p->funcFlags & SQLITE_DETERMINISTIC );
1915   testcase( p->funcFlags & SQLITE_DIRECTONLY );
1916   p->xSFunc = xSFunc ? xSFunc : xStep;
1917   p->xFinalize = xFinal;
1918   p->xValue = xValue;
1919   p->xInverse = xInverse;
1920   p->pUserData = pUserData;
1921   p->nArg = (u16)nArg;
1922   return SQLITE_OK;
1923 }
1924 
1925 /*
1926 ** Worker function used by utf-8 APIs that create new functions:
1927 **
1928 **    sqlite3_create_function()
1929 **    sqlite3_create_function_v2()
1930 **    sqlite3_create_window_function()
1931 */
1932 static int createFunctionApi(
1933   sqlite3 *db,
1934   const char *zFunc,
1935   int nArg,
1936   int enc,
1937   void *p,
1938   void (*xSFunc)(sqlite3_context*,int,sqlite3_value**),
1939   void (*xStep)(sqlite3_context*,int,sqlite3_value**),
1940   void (*xFinal)(sqlite3_context*),
1941   void (*xValue)(sqlite3_context*),
1942   void (*xInverse)(sqlite3_context*,int,sqlite3_value**),
1943   void(*xDestroy)(void*)
1944 ){
1945   int rc = SQLITE_ERROR;
1946   FuncDestructor *pArg = 0;
1947 
1948 #ifdef SQLITE_ENABLE_API_ARMOR
1949   if( !sqlite3SafetyCheckOk(db) ){
1950     return SQLITE_MISUSE_BKPT;
1951   }
1952 #endif
1953   sqlite3_mutex_enter(db->mutex);
1954   if( xDestroy ){
1955     pArg = (FuncDestructor *)sqlite3Malloc(sizeof(FuncDestructor));
1956     if( !pArg ){
1957       sqlite3OomFault(db);
1958       xDestroy(p);
1959       goto out;
1960     }
1961     pArg->nRef = 0;
1962     pArg->xDestroy = xDestroy;
1963     pArg->pUserData = p;
1964   }
1965   rc = sqlite3CreateFunc(db, zFunc, nArg, enc, p,
1966       xSFunc, xStep, xFinal, xValue, xInverse, pArg
1967   );
1968   if( pArg && pArg->nRef==0 ){
1969     assert( rc!=SQLITE_OK );
1970     xDestroy(p);
1971     sqlite3_free(pArg);
1972   }
1973 
1974  out:
1975   rc = sqlite3ApiExit(db, rc);
1976   sqlite3_mutex_leave(db->mutex);
1977   return rc;
1978 }
1979 
1980 /*
1981 ** Create new user functions.
1982 */
1983 int sqlite3_create_function(
1984   sqlite3 *db,
1985   const char *zFunc,
1986   int nArg,
1987   int enc,
1988   void *p,
1989   void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
1990   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
1991   void (*xFinal)(sqlite3_context*)
1992 ){
1993   return createFunctionApi(db, zFunc, nArg, enc, p, xSFunc, xStep,
1994                                     xFinal, 0, 0, 0);
1995 }
1996 int sqlite3_create_function_v2(
1997   sqlite3 *db,
1998   const char *zFunc,
1999   int nArg,
2000   int enc,
2001   void *p,
2002   void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
2003   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
2004   void (*xFinal)(sqlite3_context*),
2005   void (*xDestroy)(void *)
2006 ){
2007   return createFunctionApi(db, zFunc, nArg, enc, p, xSFunc, xStep,
2008                                     xFinal, 0, 0, xDestroy);
2009 }
2010 int sqlite3_create_window_function(
2011   sqlite3 *db,
2012   const char *zFunc,
2013   int nArg,
2014   int enc,
2015   void *p,
2016   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
2017   void (*xFinal)(sqlite3_context*),
2018   void (*xValue)(sqlite3_context*),
2019   void (*xInverse)(sqlite3_context*,int,sqlite3_value **),
2020   void (*xDestroy)(void *)
2021 ){
2022   return createFunctionApi(db, zFunc, nArg, enc, p, 0, xStep,
2023                                     xFinal, xValue, xInverse, xDestroy);
2024 }
2025 
2026 #ifndef SQLITE_OMIT_UTF16
2027 int sqlite3_create_function16(
2028   sqlite3 *db,
2029   const void *zFunctionName,
2030   int nArg,
2031   int eTextRep,
2032   void *p,
2033   void (*xSFunc)(sqlite3_context*,int,sqlite3_value**),
2034   void (*xStep)(sqlite3_context*,int,sqlite3_value**),
2035   void (*xFinal)(sqlite3_context*)
2036 ){
2037   int rc;
2038   char *zFunc8;
2039 
2040 #ifdef SQLITE_ENABLE_API_ARMOR
2041   if( !sqlite3SafetyCheckOk(db) || zFunctionName==0 ) return SQLITE_MISUSE_BKPT;
2042 #endif
2043   sqlite3_mutex_enter(db->mutex);
2044   assert( !db->mallocFailed );
2045   zFunc8 = sqlite3Utf16to8(db, zFunctionName, -1, SQLITE_UTF16NATIVE);
2046   rc = sqlite3CreateFunc(db, zFunc8, nArg, eTextRep, p, xSFunc,xStep,xFinal,0,0,0);
2047   sqlite3DbFree(db, zFunc8);
2048   rc = sqlite3ApiExit(db, rc);
2049   sqlite3_mutex_leave(db->mutex);
2050   return rc;
2051 }
2052 #endif
2053 
2054 
2055 /*
2056 ** The following is the implementation of an SQL function that always
2057 ** fails with an error message stating that the function is used in the
2058 ** wrong context.  The sqlite3_overload_function() API might construct
2059 ** SQL function that use this routine so that the functions will exist
2060 ** for name resolution but are actually overloaded by the xFindFunction
2061 ** method of virtual tables.
2062 */
2063 static void sqlite3InvalidFunction(
2064   sqlite3_context *context,  /* The function calling context */
2065   int NotUsed,               /* Number of arguments to the function */
2066   sqlite3_value **NotUsed2   /* Value of each argument */
2067 ){
2068   const char *zName = (const char*)sqlite3_user_data(context);
2069   char *zErr;
2070   UNUSED_PARAMETER2(NotUsed, NotUsed2);
2071   zErr = sqlite3_mprintf(
2072       "unable to use function %s in the requested context", zName);
2073   sqlite3_result_error(context, zErr, -1);
2074   sqlite3_free(zErr);
2075 }
2076 
2077 /*
2078 ** Declare that a function has been overloaded by a virtual table.
2079 **
2080 ** If the function already exists as a regular global function, then
2081 ** this routine is a no-op.  If the function does not exist, then create
2082 ** a new one that always throws a run-time error.
2083 **
2084 ** When virtual tables intend to provide an overloaded function, they
2085 ** should call this routine to make sure the global function exists.
2086 ** A global function must exist in order for name resolution to work
2087 ** properly.
2088 */
2089 int sqlite3_overload_function(
2090   sqlite3 *db,
2091   const char *zName,
2092   int nArg
2093 ){
2094   int rc;
2095   char *zCopy;
2096 
2097 #ifdef SQLITE_ENABLE_API_ARMOR
2098   if( !sqlite3SafetyCheckOk(db) || zName==0 || nArg<-2 ){
2099     return SQLITE_MISUSE_BKPT;
2100   }
2101 #endif
2102   sqlite3_mutex_enter(db->mutex);
2103   rc = sqlite3FindFunction(db, zName, nArg, SQLITE_UTF8, 0)!=0;
2104   sqlite3_mutex_leave(db->mutex);
2105   if( rc ) return SQLITE_OK;
2106   zCopy = sqlite3_mprintf(zName);
2107   if( zCopy==0 ) return SQLITE_NOMEM;
2108   return sqlite3_create_function_v2(db, zName, nArg, SQLITE_UTF8,
2109                            zCopy, sqlite3InvalidFunction, 0, 0, sqlite3_free);
2110 }
2111 
2112 #ifndef SQLITE_OMIT_TRACE
2113 /*
2114 ** Register a trace function.  The pArg from the previously registered trace
2115 ** is returned.
2116 **
2117 ** A NULL trace function means that no tracing is executes.  A non-NULL
2118 ** trace is a pointer to a function that is invoked at the start of each
2119 ** SQL statement.
2120 */
2121 #ifndef SQLITE_OMIT_DEPRECATED
2122 void *sqlite3_trace(sqlite3 *db, void(*xTrace)(void*,const char*), void *pArg){
2123   void *pOld;
2124 
2125 #ifdef SQLITE_ENABLE_API_ARMOR
2126   if( !sqlite3SafetyCheckOk(db) ){
2127     (void)SQLITE_MISUSE_BKPT;
2128     return 0;
2129   }
2130 #endif
2131   sqlite3_mutex_enter(db->mutex);
2132   pOld = db->pTraceArg;
2133   db->mTrace = xTrace ? SQLITE_TRACE_LEGACY : 0;
2134   db->trace.xLegacy = xTrace;
2135   db->pTraceArg = pArg;
2136   sqlite3_mutex_leave(db->mutex);
2137   return pOld;
2138 }
2139 #endif /* SQLITE_OMIT_DEPRECATED */
2140 
2141 /* Register a trace callback using the version-2 interface.
2142 */
2143 int sqlite3_trace_v2(
2144   sqlite3 *db,                               /* Trace this connection */
2145   unsigned mTrace,                           /* Mask of events to be traced */
2146   int(*xTrace)(unsigned,void*,void*,void*),  /* Callback to invoke */
2147   void *pArg                                 /* Context */
2148 ){
2149 #ifdef SQLITE_ENABLE_API_ARMOR
2150   if( !sqlite3SafetyCheckOk(db) ){
2151     return SQLITE_MISUSE_BKPT;
2152   }
2153 #endif
2154   sqlite3_mutex_enter(db->mutex);
2155   if( mTrace==0 ) xTrace = 0;
2156   if( xTrace==0 ) mTrace = 0;
2157   db->mTrace = mTrace;
2158   db->trace.xV2 = xTrace;
2159   db->pTraceArg = pArg;
2160   sqlite3_mutex_leave(db->mutex);
2161   return SQLITE_OK;
2162 }
2163 
2164 #ifndef SQLITE_OMIT_DEPRECATED
2165 /*
2166 ** Register a profile function.  The pArg from the previously registered
2167 ** profile function is returned.
2168 **
2169 ** A NULL profile function means that no profiling is executes.  A non-NULL
2170 ** profile is a pointer to a function that is invoked at the conclusion of
2171 ** each SQL statement that is run.
2172 */
2173 void *sqlite3_profile(
2174   sqlite3 *db,
2175   void (*xProfile)(void*,const char*,sqlite_uint64),
2176   void *pArg
2177 ){
2178   void *pOld;
2179 
2180 #ifdef SQLITE_ENABLE_API_ARMOR
2181   if( !sqlite3SafetyCheckOk(db) ){
2182     (void)SQLITE_MISUSE_BKPT;
2183     return 0;
2184   }
2185 #endif
2186   sqlite3_mutex_enter(db->mutex);
2187   pOld = db->pProfileArg;
2188   db->xProfile = xProfile;
2189   db->pProfileArg = pArg;
2190   db->mTrace &= SQLITE_TRACE_NONLEGACY_MASK;
2191   if( db->xProfile ) db->mTrace |= SQLITE_TRACE_XPROFILE;
2192   sqlite3_mutex_leave(db->mutex);
2193   return pOld;
2194 }
2195 #endif /* SQLITE_OMIT_DEPRECATED */
2196 #endif /* SQLITE_OMIT_TRACE */
2197 
2198 /*
2199 ** Register a function to be invoked when a transaction commits.
2200 ** If the invoked function returns non-zero, then the commit becomes a
2201 ** rollback.
2202 */
2203 void *sqlite3_commit_hook(
2204   sqlite3 *db,              /* Attach the hook to this database */
2205   int (*xCallback)(void*),  /* Function to invoke on each commit */
2206   void *pArg                /* Argument to the function */
2207 ){
2208   void *pOld;
2209 
2210 #ifdef SQLITE_ENABLE_API_ARMOR
2211   if( !sqlite3SafetyCheckOk(db) ){
2212     (void)SQLITE_MISUSE_BKPT;
2213     return 0;
2214   }
2215 #endif
2216   sqlite3_mutex_enter(db->mutex);
2217   pOld = db->pCommitArg;
2218   db->xCommitCallback = xCallback;
2219   db->pCommitArg = pArg;
2220   sqlite3_mutex_leave(db->mutex);
2221   return pOld;
2222 }
2223 
2224 /*
2225 ** Register a callback to be invoked each time a row is updated,
2226 ** inserted or deleted using this database connection.
2227 */
2228 void *sqlite3_update_hook(
2229   sqlite3 *db,              /* Attach the hook to this database */
2230   void (*xCallback)(void*,int,char const *,char const *,sqlite_int64),
2231   void *pArg                /* Argument to the function */
2232 ){
2233   void *pRet;
2234 
2235 #ifdef SQLITE_ENABLE_API_ARMOR
2236   if( !sqlite3SafetyCheckOk(db) ){
2237     (void)SQLITE_MISUSE_BKPT;
2238     return 0;
2239   }
2240 #endif
2241   sqlite3_mutex_enter(db->mutex);
2242   pRet = db->pUpdateArg;
2243   db->xUpdateCallback = xCallback;
2244   db->pUpdateArg = pArg;
2245   sqlite3_mutex_leave(db->mutex);
2246   return pRet;
2247 }
2248 
2249 /*
2250 ** Register a callback to be invoked each time a transaction is rolled
2251 ** back by this database connection.
2252 */
2253 void *sqlite3_rollback_hook(
2254   sqlite3 *db,              /* Attach the hook to this database */
2255   void (*xCallback)(void*), /* Callback function */
2256   void *pArg                /* Argument to the function */
2257 ){
2258   void *pRet;
2259 
2260 #ifdef SQLITE_ENABLE_API_ARMOR
2261   if( !sqlite3SafetyCheckOk(db) ){
2262     (void)SQLITE_MISUSE_BKPT;
2263     return 0;
2264   }
2265 #endif
2266   sqlite3_mutex_enter(db->mutex);
2267   pRet = db->pRollbackArg;
2268   db->xRollbackCallback = xCallback;
2269   db->pRollbackArg = pArg;
2270   sqlite3_mutex_leave(db->mutex);
2271   return pRet;
2272 }
2273 
2274 #ifdef SQLITE_ENABLE_PREUPDATE_HOOK
2275 /*
2276 ** Register a callback to be invoked each time a row is updated,
2277 ** inserted or deleted using this database connection.
2278 */
2279 void *sqlite3_preupdate_hook(
2280   sqlite3 *db,              /* Attach the hook to this database */
2281   void(*xCallback)(         /* Callback function */
2282     void*,sqlite3*,int,char const*,char const*,sqlite3_int64,sqlite3_int64),
2283   void *pArg                /* First callback argument */
2284 ){
2285   void *pRet;
2286   sqlite3_mutex_enter(db->mutex);
2287   pRet = db->pPreUpdateArg;
2288   db->xPreUpdateCallback = xCallback;
2289   db->pPreUpdateArg = pArg;
2290   sqlite3_mutex_leave(db->mutex);
2291   return pRet;
2292 }
2293 #endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
2294 
2295 #ifndef SQLITE_OMIT_WAL
2296 /*
2297 ** The sqlite3_wal_hook() callback registered by sqlite3_wal_autocheckpoint().
2298 ** Invoke sqlite3_wal_checkpoint if the number of frames in the log file
2299 ** is greater than sqlite3.pWalArg cast to an integer (the value configured by
2300 ** wal_autocheckpoint()).
2301 */
2302 int sqlite3WalDefaultHook(
2303   void *pClientData,     /* Argument */
2304   sqlite3 *db,           /* Connection */
2305   const char *zDb,       /* Database */
2306   int nFrame             /* Size of WAL */
2307 ){
2308   if( nFrame>=SQLITE_PTR_TO_INT(pClientData) ){
2309     sqlite3BeginBenignMalloc();
2310     sqlite3_wal_checkpoint(db, zDb);
2311     sqlite3EndBenignMalloc();
2312   }
2313   return SQLITE_OK;
2314 }
2315 #endif /* SQLITE_OMIT_WAL */
2316 
2317 /*
2318 ** Configure an sqlite3_wal_hook() callback to automatically checkpoint
2319 ** a database after committing a transaction if there are nFrame or
2320 ** more frames in the log file. Passing zero or a negative value as the
2321 ** nFrame parameter disables automatic checkpoints entirely.
2322 **
2323 ** The callback registered by this function replaces any existing callback
2324 ** registered using sqlite3_wal_hook(). Likewise, registering a callback
2325 ** using sqlite3_wal_hook() disables the automatic checkpoint mechanism
2326 ** configured by this function.
2327 */
2328 int sqlite3_wal_autocheckpoint(sqlite3 *db, int nFrame){
2329 #ifdef SQLITE_OMIT_WAL
2330   UNUSED_PARAMETER(db);
2331   UNUSED_PARAMETER(nFrame);
2332 #else
2333 #ifdef SQLITE_ENABLE_API_ARMOR
2334   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
2335 #endif
2336   if( nFrame>0 ){
2337     sqlite3_wal_hook(db, sqlite3WalDefaultHook, SQLITE_INT_TO_PTR(nFrame));
2338   }else{
2339     sqlite3_wal_hook(db, 0, 0);
2340   }
2341 #endif
2342   return SQLITE_OK;
2343 }
2344 
2345 /*
2346 ** Register a callback to be invoked each time a transaction is written
2347 ** into the write-ahead-log by this database connection.
2348 */
2349 void *sqlite3_wal_hook(
2350   sqlite3 *db,                    /* Attach the hook to this db handle */
2351   int(*xCallback)(void *, sqlite3*, const char*, int),
2352   void *pArg                      /* First argument passed to xCallback() */
2353 ){
2354 #ifndef SQLITE_OMIT_WAL
2355   void *pRet;
2356 #ifdef SQLITE_ENABLE_API_ARMOR
2357   if( !sqlite3SafetyCheckOk(db) ){
2358     (void)SQLITE_MISUSE_BKPT;
2359     return 0;
2360   }
2361 #endif
2362   sqlite3_mutex_enter(db->mutex);
2363   pRet = db->pWalArg;
2364   db->xWalCallback = xCallback;
2365   db->pWalArg = pArg;
2366   sqlite3_mutex_leave(db->mutex);
2367   return pRet;
2368 #else
2369   return 0;
2370 #endif
2371 }
2372 
2373 /*
2374 ** Checkpoint database zDb.
2375 */
2376 int sqlite3_wal_checkpoint_v2(
2377   sqlite3 *db,                    /* Database handle */
2378   const char *zDb,                /* Name of attached database (or NULL) */
2379   int eMode,                      /* SQLITE_CHECKPOINT_* value */
2380   int *pnLog,                     /* OUT: Size of WAL log in frames */
2381   int *pnCkpt                     /* OUT: Total number of frames checkpointed */
2382 ){
2383 #ifdef SQLITE_OMIT_WAL
2384   return SQLITE_OK;
2385 #else
2386   int rc;                         /* Return code */
2387   int iDb;                        /* Schema to checkpoint */
2388 
2389 #ifdef SQLITE_ENABLE_API_ARMOR
2390   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
2391 #endif
2392 
2393   /* Initialize the output variables to -1 in case an error occurs. */
2394   if( pnLog ) *pnLog = -1;
2395   if( pnCkpt ) *pnCkpt = -1;
2396 
2397   assert( SQLITE_CHECKPOINT_PASSIVE==0 );
2398   assert( SQLITE_CHECKPOINT_FULL==1 );
2399   assert( SQLITE_CHECKPOINT_RESTART==2 );
2400   assert( SQLITE_CHECKPOINT_TRUNCATE==3 );
2401   if( eMode<SQLITE_CHECKPOINT_PASSIVE || eMode>SQLITE_CHECKPOINT_TRUNCATE ){
2402     /* EVIDENCE-OF: R-03996-12088 The M parameter must be a valid checkpoint
2403     ** mode: */
2404     return SQLITE_MISUSE;
2405   }
2406 
2407   sqlite3_mutex_enter(db->mutex);
2408   if( zDb && zDb[0] ){
2409     iDb = sqlite3FindDbName(db, zDb);
2410   }else{
2411     iDb = SQLITE_MAX_DB;   /* This means process all schemas */
2412   }
2413   if( iDb<0 ){
2414     rc = SQLITE_ERROR;
2415     sqlite3ErrorWithMsg(db, SQLITE_ERROR, "unknown database: %s", zDb);
2416   }else{
2417     db->busyHandler.nBusy = 0;
2418     rc = sqlite3Checkpoint(db, iDb, eMode, pnLog, pnCkpt);
2419     sqlite3Error(db, rc);
2420   }
2421   rc = sqlite3ApiExit(db, rc);
2422 
2423   /* If there are no active statements, clear the interrupt flag at this
2424   ** point.  */
2425   if( db->nVdbeActive==0 ){
2426     AtomicStore(&db->u1.isInterrupted, 0);
2427   }
2428 
2429   sqlite3_mutex_leave(db->mutex);
2430   return rc;
2431 #endif
2432 }
2433 
2434 
2435 /*
2436 ** Checkpoint database zDb. If zDb is NULL, or if the buffer zDb points
2437 ** to contains a zero-length string, all attached databases are
2438 ** checkpointed.
2439 */
2440 int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb){
2441   /* EVIDENCE-OF: R-41613-20553 The sqlite3_wal_checkpoint(D,X) is equivalent to
2442   ** sqlite3_wal_checkpoint_v2(D,X,SQLITE_CHECKPOINT_PASSIVE,0,0). */
2443   return sqlite3_wal_checkpoint_v2(db,zDb,SQLITE_CHECKPOINT_PASSIVE,0,0);
2444 }
2445 
2446 #ifndef SQLITE_OMIT_WAL
2447 /*
2448 ** Run a checkpoint on database iDb. This is a no-op if database iDb is
2449 ** not currently open in WAL mode.
2450 **
2451 ** If a transaction is open on the database being checkpointed, this
2452 ** function returns SQLITE_LOCKED and a checkpoint is not attempted. If
2453 ** an error occurs while running the checkpoint, an SQLite error code is
2454 ** returned (i.e. SQLITE_IOERR). Otherwise, SQLITE_OK.
2455 **
2456 ** The mutex on database handle db should be held by the caller. The mutex
2457 ** associated with the specific b-tree being checkpointed is taken by
2458 ** this function while the checkpoint is running.
2459 **
2460 ** If iDb is passed SQLITE_MAX_DB then all attached databases are
2461 ** checkpointed. If an error is encountered it is returned immediately -
2462 ** no attempt is made to checkpoint any remaining databases.
2463 **
2464 ** Parameter eMode is one of SQLITE_CHECKPOINT_PASSIVE, FULL, RESTART
2465 ** or TRUNCATE.
2466 */
2467 int sqlite3Checkpoint(sqlite3 *db, int iDb, int eMode, int *pnLog, int *pnCkpt){
2468   int rc = SQLITE_OK;             /* Return code */
2469   int i;                          /* Used to iterate through attached dbs */
2470   int bBusy = 0;                  /* True if SQLITE_BUSY has been encountered */
2471 
2472   assert( sqlite3_mutex_held(db->mutex) );
2473   assert( !pnLog || *pnLog==-1 );
2474   assert( !pnCkpt || *pnCkpt==-1 );
2475   testcase( iDb==SQLITE_MAX_ATTACHED ); /* See forum post a006d86f72 */
2476   testcase( iDb==SQLITE_MAX_DB );
2477 
2478   for(i=0; i<db->nDb && rc==SQLITE_OK; i++){
2479     if( i==iDb || iDb==SQLITE_MAX_DB ){
2480       rc = sqlite3BtreeCheckpoint(db->aDb[i].pBt, eMode, pnLog, pnCkpt);
2481       pnLog = 0;
2482       pnCkpt = 0;
2483       if( rc==SQLITE_BUSY ){
2484         bBusy = 1;
2485         rc = SQLITE_OK;
2486       }
2487     }
2488   }
2489 
2490   return (rc==SQLITE_OK && bBusy) ? SQLITE_BUSY : rc;
2491 }
2492 #endif /* SQLITE_OMIT_WAL */
2493 
2494 /*
2495 ** This function returns true if main-memory should be used instead of
2496 ** a temporary file for transient pager files and statement journals.
2497 ** The value returned depends on the value of db->temp_store (runtime
2498 ** parameter) and the compile time value of SQLITE_TEMP_STORE. The
2499 ** following table describes the relationship between these two values
2500 ** and this functions return value.
2501 **
2502 **   SQLITE_TEMP_STORE     db->temp_store     Location of temporary database
2503 **   -----------------     --------------     ------------------------------
2504 **   0                     any                file      (return 0)
2505 **   1                     1                  file      (return 0)
2506 **   1                     2                  memory    (return 1)
2507 **   1                     0                  file      (return 0)
2508 **   2                     1                  file      (return 0)
2509 **   2                     2                  memory    (return 1)
2510 **   2                     0                  memory    (return 1)
2511 **   3                     any                memory    (return 1)
2512 */
2513 int sqlite3TempInMemory(const sqlite3 *db){
2514 #if SQLITE_TEMP_STORE==1
2515   return ( db->temp_store==2 );
2516 #endif
2517 #if SQLITE_TEMP_STORE==2
2518   return ( db->temp_store!=1 );
2519 #endif
2520 #if SQLITE_TEMP_STORE==3
2521   UNUSED_PARAMETER(db);
2522   return 1;
2523 #endif
2524 #if SQLITE_TEMP_STORE<1 || SQLITE_TEMP_STORE>3
2525   UNUSED_PARAMETER(db);
2526   return 0;
2527 #endif
2528 }
2529 
2530 /*
2531 ** Return UTF-8 encoded English language explanation of the most recent
2532 ** error.
2533 */
2534 const char *sqlite3_errmsg(sqlite3 *db){
2535   const char *z;
2536   if( !db ){
2537     return sqlite3ErrStr(SQLITE_NOMEM_BKPT);
2538   }
2539   if( !sqlite3SafetyCheckSickOrOk(db) ){
2540     return sqlite3ErrStr(SQLITE_MISUSE_BKPT);
2541   }
2542   sqlite3_mutex_enter(db->mutex);
2543   if( db->mallocFailed ){
2544     z = sqlite3ErrStr(SQLITE_NOMEM_BKPT);
2545   }else{
2546     testcase( db->pErr==0 );
2547     z = db->errCode ? (char*)sqlite3_value_text(db->pErr) : 0;
2548     assert( !db->mallocFailed );
2549     if( z==0 ){
2550       z = sqlite3ErrStr(db->errCode);
2551     }
2552   }
2553   sqlite3_mutex_leave(db->mutex);
2554   return z;
2555 }
2556 
2557 #ifndef SQLITE_OMIT_UTF16
2558 /*
2559 ** Return UTF-16 encoded English language explanation of the most recent
2560 ** error.
2561 */
2562 const void *sqlite3_errmsg16(sqlite3 *db){
2563   static const u16 outOfMem[] = {
2564     'o', 'u', 't', ' ', 'o', 'f', ' ', 'm', 'e', 'm', 'o', 'r', 'y', 0
2565   };
2566   static const u16 misuse[] = {
2567     'b', 'a', 'd', ' ', 'p', 'a', 'r', 'a', 'm', 'e', 't', 'e', 'r', ' ',
2568     'o', 'r', ' ', 'o', 't', 'h', 'e', 'r', ' ', 'A', 'P', 'I', ' ',
2569     'm', 'i', 's', 'u', 's', 'e', 0
2570   };
2571 
2572   const void *z;
2573   if( !db ){
2574     return (void *)outOfMem;
2575   }
2576   if( !sqlite3SafetyCheckSickOrOk(db) ){
2577     return (void *)misuse;
2578   }
2579   sqlite3_mutex_enter(db->mutex);
2580   if( db->mallocFailed ){
2581     z = (void *)outOfMem;
2582   }else{
2583     z = sqlite3_value_text16(db->pErr);
2584     if( z==0 ){
2585       sqlite3ErrorWithMsg(db, db->errCode, sqlite3ErrStr(db->errCode));
2586       z = sqlite3_value_text16(db->pErr);
2587     }
2588     /* A malloc() may have failed within the call to sqlite3_value_text16()
2589     ** above. If this is the case, then the db->mallocFailed flag needs to
2590     ** be cleared before returning. Do this directly, instead of via
2591     ** sqlite3ApiExit(), to avoid setting the database handle error message.
2592     */
2593     sqlite3OomClear(db);
2594   }
2595   sqlite3_mutex_leave(db->mutex);
2596   return z;
2597 }
2598 #endif /* SQLITE_OMIT_UTF16 */
2599 
2600 /*
2601 ** Return the most recent error code generated by an SQLite routine. If NULL is
2602 ** passed to this function, we assume a malloc() failed during sqlite3_open().
2603 */
2604 int sqlite3_errcode(sqlite3 *db){
2605   if( db && !sqlite3SafetyCheckSickOrOk(db) ){
2606     return SQLITE_MISUSE_BKPT;
2607   }
2608   if( !db || db->mallocFailed ){
2609     return SQLITE_NOMEM_BKPT;
2610   }
2611   return db->errCode & db->errMask;
2612 }
2613 int sqlite3_extended_errcode(sqlite3 *db){
2614   if( db && !sqlite3SafetyCheckSickOrOk(db) ){
2615     return SQLITE_MISUSE_BKPT;
2616   }
2617   if( !db || db->mallocFailed ){
2618     return SQLITE_NOMEM_BKPT;
2619   }
2620   return db->errCode;
2621 }
2622 int sqlite3_system_errno(sqlite3 *db){
2623   return db ? db->iSysErrno : 0;
2624 }
2625 
2626 /*
2627 ** Return a string that describes the kind of error specified in the
2628 ** argument.  For now, this simply calls the internal sqlite3ErrStr()
2629 ** function.
2630 */
2631 const char *sqlite3_errstr(int rc){
2632   return sqlite3ErrStr(rc);
2633 }
2634 
2635 /*
2636 ** Create a new collating function for database "db".  The name is zName
2637 ** and the encoding is enc.
2638 */
2639 static int createCollation(
2640   sqlite3* db,
2641   const char *zName,
2642   u8 enc,
2643   void* pCtx,
2644   int(*xCompare)(void*,int,const void*,int,const void*),
2645   void(*xDel)(void*)
2646 ){
2647   CollSeq *pColl;
2648   int enc2;
2649 
2650   assert( sqlite3_mutex_held(db->mutex) );
2651 
2652   /* If SQLITE_UTF16 is specified as the encoding type, transform this
2653   ** to one of SQLITE_UTF16LE or SQLITE_UTF16BE using the
2654   ** SQLITE_UTF16NATIVE macro. SQLITE_UTF16 is not used internally.
2655   */
2656   enc2 = enc;
2657   testcase( enc2==SQLITE_UTF16 );
2658   testcase( enc2==SQLITE_UTF16_ALIGNED );
2659   if( enc2==SQLITE_UTF16 || enc2==SQLITE_UTF16_ALIGNED ){
2660     enc2 = SQLITE_UTF16NATIVE;
2661   }
2662   if( enc2<SQLITE_UTF8 || enc2>SQLITE_UTF16BE ){
2663     return SQLITE_MISUSE_BKPT;
2664   }
2665 
2666   /* Check if this call is removing or replacing an existing collation
2667   ** sequence. If so, and there are active VMs, return busy. If there
2668   ** are no active VMs, invalidate any pre-compiled statements.
2669   */
2670   pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, 0);
2671   if( pColl && pColl->xCmp ){
2672     if( db->nVdbeActive ){
2673       sqlite3ErrorWithMsg(db, SQLITE_BUSY,
2674         "unable to delete/modify collation sequence due to active statements");
2675       return SQLITE_BUSY;
2676     }
2677     sqlite3ExpirePreparedStatements(db, 0);
2678 
2679     /* If collation sequence pColl was created directly by a call to
2680     ** sqlite3_create_collation, and not generated by synthCollSeq(),
2681     ** then any copies made by synthCollSeq() need to be invalidated.
2682     ** Also, collation destructor - CollSeq.xDel() - function may need
2683     ** to be called.
2684     */
2685     if( (pColl->enc & ~SQLITE_UTF16_ALIGNED)==enc2 ){
2686       CollSeq *aColl = sqlite3HashFind(&db->aCollSeq, zName);
2687       int j;
2688       for(j=0; j<3; j++){
2689         CollSeq *p = &aColl[j];
2690         if( p->enc==pColl->enc ){
2691           if( p->xDel ){
2692             p->xDel(p->pUser);
2693           }
2694           p->xCmp = 0;
2695         }
2696       }
2697     }
2698   }
2699 
2700   pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, 1);
2701   if( pColl==0 ) return SQLITE_NOMEM_BKPT;
2702   pColl->xCmp = xCompare;
2703   pColl->pUser = pCtx;
2704   pColl->xDel = xDel;
2705   pColl->enc = (u8)(enc2 | (enc & SQLITE_UTF16_ALIGNED));
2706   sqlite3Error(db, SQLITE_OK);
2707   return SQLITE_OK;
2708 }
2709 
2710 
2711 /*
2712 ** This array defines hard upper bounds on limit values.  The
2713 ** initializer must be kept in sync with the SQLITE_LIMIT_*
2714 ** #defines in sqlite3.h.
2715 */
2716 static const int aHardLimit[] = {
2717   SQLITE_MAX_LENGTH,
2718   SQLITE_MAX_SQL_LENGTH,
2719   SQLITE_MAX_COLUMN,
2720   SQLITE_MAX_EXPR_DEPTH,
2721   SQLITE_MAX_COMPOUND_SELECT,
2722   SQLITE_MAX_VDBE_OP,
2723   SQLITE_MAX_FUNCTION_ARG,
2724   SQLITE_MAX_ATTACHED,
2725   SQLITE_MAX_LIKE_PATTERN_LENGTH,
2726   SQLITE_MAX_VARIABLE_NUMBER,      /* IMP: R-38091-32352 */
2727   SQLITE_MAX_TRIGGER_DEPTH,
2728   SQLITE_MAX_WORKER_THREADS,
2729 };
2730 
2731 /*
2732 ** Make sure the hard limits are set to reasonable values
2733 */
2734 #if SQLITE_MAX_LENGTH<100
2735 # error SQLITE_MAX_LENGTH must be at least 100
2736 #endif
2737 #if SQLITE_MAX_SQL_LENGTH<100
2738 # error SQLITE_MAX_SQL_LENGTH must be at least 100
2739 #endif
2740 #if SQLITE_MAX_SQL_LENGTH>SQLITE_MAX_LENGTH
2741 # error SQLITE_MAX_SQL_LENGTH must not be greater than SQLITE_MAX_LENGTH
2742 #endif
2743 #if SQLITE_MAX_COMPOUND_SELECT<2
2744 # error SQLITE_MAX_COMPOUND_SELECT must be at least 2
2745 #endif
2746 #if SQLITE_MAX_VDBE_OP<40
2747 # error SQLITE_MAX_VDBE_OP must be at least 40
2748 #endif
2749 #if SQLITE_MAX_FUNCTION_ARG<0 || SQLITE_MAX_FUNCTION_ARG>127
2750 # error SQLITE_MAX_FUNCTION_ARG must be between 0 and 127
2751 #endif
2752 #if SQLITE_MAX_ATTACHED<0 || SQLITE_MAX_ATTACHED>125
2753 # error SQLITE_MAX_ATTACHED must be between 0 and 125
2754 #endif
2755 #if SQLITE_MAX_LIKE_PATTERN_LENGTH<1
2756 # error SQLITE_MAX_LIKE_PATTERN_LENGTH must be at least 1
2757 #endif
2758 #if SQLITE_MAX_COLUMN>32767
2759 # error SQLITE_MAX_COLUMN must not exceed 32767
2760 #endif
2761 #if SQLITE_MAX_TRIGGER_DEPTH<1
2762 # error SQLITE_MAX_TRIGGER_DEPTH must be at least 1
2763 #endif
2764 #if SQLITE_MAX_WORKER_THREADS<0 || SQLITE_MAX_WORKER_THREADS>50
2765 # error SQLITE_MAX_WORKER_THREADS must be between 0 and 50
2766 #endif
2767 
2768 
2769 /*
2770 ** Change the value of a limit.  Report the old value.
2771 ** If an invalid limit index is supplied, report -1.
2772 ** Make no changes but still report the old value if the
2773 ** new limit is negative.
2774 **
2775 ** A new lower limit does not shrink existing constructs.
2776 ** It merely prevents new constructs that exceed the limit
2777 ** from forming.
2778 */
2779 int sqlite3_limit(sqlite3 *db, int limitId, int newLimit){
2780   int oldLimit;
2781 
2782 #ifdef SQLITE_ENABLE_API_ARMOR
2783   if( !sqlite3SafetyCheckOk(db) ){
2784     (void)SQLITE_MISUSE_BKPT;
2785     return -1;
2786   }
2787 #endif
2788 
2789   /* EVIDENCE-OF: R-30189-54097 For each limit category SQLITE_LIMIT_NAME
2790   ** there is a hard upper bound set at compile-time by a C preprocessor
2791   ** macro called SQLITE_MAX_NAME. (The "_LIMIT_" in the name is changed to
2792   ** "_MAX_".)
2793   */
2794   assert( aHardLimit[SQLITE_LIMIT_LENGTH]==SQLITE_MAX_LENGTH );
2795   assert( aHardLimit[SQLITE_LIMIT_SQL_LENGTH]==SQLITE_MAX_SQL_LENGTH );
2796   assert( aHardLimit[SQLITE_LIMIT_COLUMN]==SQLITE_MAX_COLUMN );
2797   assert( aHardLimit[SQLITE_LIMIT_EXPR_DEPTH]==SQLITE_MAX_EXPR_DEPTH );
2798   assert( aHardLimit[SQLITE_LIMIT_COMPOUND_SELECT]==SQLITE_MAX_COMPOUND_SELECT);
2799   assert( aHardLimit[SQLITE_LIMIT_VDBE_OP]==SQLITE_MAX_VDBE_OP );
2800   assert( aHardLimit[SQLITE_LIMIT_FUNCTION_ARG]==SQLITE_MAX_FUNCTION_ARG );
2801   assert( aHardLimit[SQLITE_LIMIT_ATTACHED]==SQLITE_MAX_ATTACHED );
2802   assert( aHardLimit[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]==
2803                                                SQLITE_MAX_LIKE_PATTERN_LENGTH );
2804   assert( aHardLimit[SQLITE_LIMIT_VARIABLE_NUMBER]==SQLITE_MAX_VARIABLE_NUMBER);
2805   assert( aHardLimit[SQLITE_LIMIT_TRIGGER_DEPTH]==SQLITE_MAX_TRIGGER_DEPTH );
2806   assert( aHardLimit[SQLITE_LIMIT_WORKER_THREADS]==SQLITE_MAX_WORKER_THREADS );
2807   assert( SQLITE_LIMIT_WORKER_THREADS==(SQLITE_N_LIMIT-1) );
2808 
2809 
2810   if( limitId<0 || limitId>=SQLITE_N_LIMIT ){
2811     return -1;
2812   }
2813   oldLimit = db->aLimit[limitId];
2814   if( newLimit>=0 ){                   /* IMP: R-52476-28732 */
2815     if( newLimit>aHardLimit[limitId] ){
2816       newLimit = aHardLimit[limitId];  /* IMP: R-51463-25634 */
2817     }
2818     db->aLimit[limitId] = newLimit;
2819   }
2820   return oldLimit;                     /* IMP: R-53341-35419 */
2821 }
2822 
2823 /*
2824 ** This function is used to parse both URIs and non-URI filenames passed by the
2825 ** user to API functions sqlite3_open() or sqlite3_open_v2(), and for database
2826 ** URIs specified as part of ATTACH statements.
2827 **
2828 ** The first argument to this function is the name of the VFS to use (or
2829 ** a NULL to signify the default VFS) if the URI does not contain a "vfs=xxx"
2830 ** query parameter. The second argument contains the URI (or non-URI filename)
2831 ** itself. When this function is called the *pFlags variable should contain
2832 ** the default flags to open the database handle with. The value stored in
2833 ** *pFlags may be updated before returning if the URI filename contains
2834 ** "cache=xxx" or "mode=xxx" query parameters.
2835 **
2836 ** If successful, SQLITE_OK is returned. In this case *ppVfs is set to point to
2837 ** the VFS that should be used to open the database file. *pzFile is set to
2838 ** point to a buffer containing the name of the file to open.  The value
2839 ** stored in *pzFile is a database name acceptable to sqlite3_uri_parameter()
2840 ** and is in the same format as names created using sqlite3_create_filename().
2841 ** The caller must invoke sqlite3_free_filename() (not sqlite3_free()!) on
2842 ** the value returned in *pzFile to avoid a memory leak.
2843 **
2844 ** If an error occurs, then an SQLite error code is returned and *pzErrMsg
2845 ** may be set to point to a buffer containing an English language error
2846 ** message. It is the responsibility of the caller to eventually release
2847 ** this buffer by calling sqlite3_free().
2848 */
2849 int sqlite3ParseUri(
2850   const char *zDefaultVfs,        /* VFS to use if no "vfs=xxx" query option */
2851   const char *zUri,               /* Nul-terminated URI to parse */
2852   unsigned int *pFlags,           /* IN/OUT: SQLITE_OPEN_XXX flags */
2853   sqlite3_vfs **ppVfs,            /* OUT: VFS to use */
2854   char **pzFile,                  /* OUT: Filename component of URI */
2855   char **pzErrMsg                 /* OUT: Error message (if rc!=SQLITE_OK) */
2856 ){
2857   int rc = SQLITE_OK;
2858   unsigned int flags = *pFlags;
2859   const char *zVfs = zDefaultVfs;
2860   char *zFile;
2861   char c;
2862   int nUri = sqlite3Strlen30(zUri);
2863 
2864   assert( *pzErrMsg==0 );
2865 
2866   if( ((flags & SQLITE_OPEN_URI)             /* IMP: R-48725-32206 */
2867             || sqlite3GlobalConfig.bOpenUri) /* IMP: R-51689-46548 */
2868    && nUri>=5 && memcmp(zUri, "file:", 5)==0 /* IMP: R-57884-37496 */
2869   ){
2870     char *zOpt;
2871     int eState;                   /* Parser state when parsing URI */
2872     int iIn;                      /* Input character index */
2873     int iOut = 0;                 /* Output character index */
2874     u64 nByte = nUri+8;           /* Bytes of space to allocate */
2875 
2876     /* Make sure the SQLITE_OPEN_URI flag is set to indicate to the VFS xOpen
2877     ** method that there may be extra parameters following the file-name.  */
2878     flags |= SQLITE_OPEN_URI;
2879 
2880     for(iIn=0; iIn<nUri; iIn++) nByte += (zUri[iIn]=='&');
2881     zFile = sqlite3_malloc64(nByte);
2882     if( !zFile ) return SQLITE_NOMEM_BKPT;
2883 
2884     memset(zFile, 0, 4);  /* 4-byte of 0x00 is the start of DB name marker */
2885     zFile += 4;
2886 
2887     iIn = 5;
2888 #ifdef SQLITE_ALLOW_URI_AUTHORITY
2889     if( strncmp(zUri+5, "///", 3)==0 ){
2890       iIn = 7;
2891       /* The following condition causes URIs with five leading / characters
2892       ** like file://///host/path to be converted into UNCs like //host/path.
2893       ** The correct URI for that UNC has only two or four leading / characters
2894       ** file://host/path or file:////host/path.  But 5 leading slashes is a
2895       ** common error, we are told, so we handle it as a special case. */
2896       if( strncmp(zUri+7, "///", 3)==0 ){ iIn++; }
2897     }else if( strncmp(zUri+5, "//localhost/", 12)==0 ){
2898       iIn = 16;
2899     }
2900 #else
2901     /* Discard the scheme and authority segments of the URI. */
2902     if( zUri[5]=='/' && zUri[6]=='/' ){
2903       iIn = 7;
2904       while( zUri[iIn] && zUri[iIn]!='/' ) iIn++;
2905       if( iIn!=7 && (iIn!=16 || memcmp("localhost", &zUri[7], 9)) ){
2906         *pzErrMsg = sqlite3_mprintf("invalid uri authority: %.*s",
2907             iIn-7, &zUri[7]);
2908         rc = SQLITE_ERROR;
2909         goto parse_uri_out;
2910       }
2911     }
2912 #endif
2913 
2914     /* Copy the filename and any query parameters into the zFile buffer.
2915     ** Decode %HH escape codes along the way.
2916     **
2917     ** Within this loop, variable eState may be set to 0, 1 or 2, depending
2918     ** on the parsing context. As follows:
2919     **
2920     **   0: Parsing file-name.
2921     **   1: Parsing name section of a name=value query parameter.
2922     **   2: Parsing value section of a name=value query parameter.
2923     */
2924     eState = 0;
2925     while( (c = zUri[iIn])!=0 && c!='#' ){
2926       iIn++;
2927       if( c=='%'
2928        && sqlite3Isxdigit(zUri[iIn])
2929        && sqlite3Isxdigit(zUri[iIn+1])
2930       ){
2931         int octet = (sqlite3HexToInt(zUri[iIn++]) << 4);
2932         octet += sqlite3HexToInt(zUri[iIn++]);
2933 
2934         assert( octet>=0 && octet<256 );
2935         if( octet==0 ){
2936 #ifndef SQLITE_ENABLE_URI_00_ERROR
2937           /* This branch is taken when "%00" appears within the URI. In this
2938           ** case we ignore all text in the remainder of the path, name or
2939           ** value currently being parsed. So ignore the current character
2940           ** and skip to the next "?", "=" or "&", as appropriate. */
2941           while( (c = zUri[iIn])!=0 && c!='#'
2942               && (eState!=0 || c!='?')
2943               && (eState!=1 || (c!='=' && c!='&'))
2944               && (eState!=2 || c!='&')
2945           ){
2946             iIn++;
2947           }
2948           continue;
2949 #else
2950           /* If ENABLE_URI_00_ERROR is defined, "%00" in a URI is an error. */
2951           *pzErrMsg = sqlite3_mprintf("unexpected %%00 in uri");
2952           rc = SQLITE_ERROR;
2953           goto parse_uri_out;
2954 #endif
2955         }
2956         c = octet;
2957       }else if( eState==1 && (c=='&' || c=='=') ){
2958         if( zFile[iOut-1]==0 ){
2959           /* An empty option name. Ignore this option altogether. */
2960           while( zUri[iIn] && zUri[iIn]!='#' && zUri[iIn-1]!='&' ) iIn++;
2961           continue;
2962         }
2963         if( c=='&' ){
2964           zFile[iOut++] = '\0';
2965         }else{
2966           eState = 2;
2967         }
2968         c = 0;
2969       }else if( (eState==0 && c=='?') || (eState==2 && c=='&') ){
2970         c = 0;
2971         eState = 1;
2972       }
2973       zFile[iOut++] = c;
2974     }
2975     if( eState==1 ) zFile[iOut++] = '\0';
2976     memset(zFile+iOut, 0, 4); /* end-of-options + empty journal filenames */
2977 
2978     /* Check if there were any options specified that should be interpreted
2979     ** here. Options that are interpreted here include "vfs" and those that
2980     ** correspond to flags that may be passed to the sqlite3_open_v2()
2981     ** method. */
2982     zOpt = &zFile[sqlite3Strlen30(zFile)+1];
2983     while( zOpt[0] ){
2984       int nOpt = sqlite3Strlen30(zOpt);
2985       char *zVal = &zOpt[nOpt+1];
2986       int nVal = sqlite3Strlen30(zVal);
2987 
2988       if( nOpt==3 && memcmp("vfs", zOpt, 3)==0 ){
2989         zVfs = zVal;
2990       }else{
2991         struct OpenMode {
2992           const char *z;
2993           int mode;
2994         } *aMode = 0;
2995         char *zModeType = 0;
2996         int mask = 0;
2997         int limit = 0;
2998 
2999         if( nOpt==5 && memcmp("cache", zOpt, 5)==0 ){
3000           static struct OpenMode aCacheMode[] = {
3001             { "shared",  SQLITE_OPEN_SHAREDCACHE },
3002             { "private", SQLITE_OPEN_PRIVATECACHE },
3003             { 0, 0 }
3004           };
3005 
3006           mask = SQLITE_OPEN_SHAREDCACHE|SQLITE_OPEN_PRIVATECACHE;
3007           aMode = aCacheMode;
3008           limit = mask;
3009           zModeType = "cache";
3010         }
3011         if( nOpt==4 && memcmp("mode", zOpt, 4)==0 ){
3012           static struct OpenMode aOpenMode[] = {
3013             { "ro",  SQLITE_OPEN_READONLY },
3014             { "rw",  SQLITE_OPEN_READWRITE },
3015             { "rwc", SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE },
3016             { "memory", SQLITE_OPEN_MEMORY },
3017             { 0, 0 }
3018           };
3019 
3020           mask = SQLITE_OPEN_READONLY | SQLITE_OPEN_READWRITE
3021                    | SQLITE_OPEN_CREATE | SQLITE_OPEN_MEMORY;
3022           aMode = aOpenMode;
3023           limit = mask & flags;
3024           zModeType = "access";
3025         }
3026 
3027         if( aMode ){
3028           int i;
3029           int mode = 0;
3030           for(i=0; aMode[i].z; i++){
3031             const char *z = aMode[i].z;
3032             if( nVal==sqlite3Strlen30(z) && 0==memcmp(zVal, z, nVal) ){
3033               mode = aMode[i].mode;
3034               break;
3035             }
3036           }
3037           if( mode==0 ){
3038             *pzErrMsg = sqlite3_mprintf("no such %s mode: %s", zModeType, zVal);
3039             rc = SQLITE_ERROR;
3040             goto parse_uri_out;
3041           }
3042           if( (mode & ~SQLITE_OPEN_MEMORY)>limit ){
3043             *pzErrMsg = sqlite3_mprintf("%s mode not allowed: %s",
3044                                         zModeType, zVal);
3045             rc = SQLITE_PERM;
3046             goto parse_uri_out;
3047           }
3048           flags = (flags & ~mask) | mode;
3049         }
3050       }
3051 
3052       zOpt = &zVal[nVal+1];
3053     }
3054 
3055   }else{
3056     zFile = sqlite3_malloc64(nUri+8);
3057     if( !zFile ) return SQLITE_NOMEM_BKPT;
3058     memset(zFile, 0, 4);
3059     zFile += 4;
3060     if( nUri ){
3061       memcpy(zFile, zUri, nUri);
3062     }
3063     memset(zFile+nUri, 0, 4);
3064     flags &= ~SQLITE_OPEN_URI;
3065   }
3066 
3067   *ppVfs = sqlite3_vfs_find(zVfs);
3068   if( *ppVfs==0 ){
3069     *pzErrMsg = sqlite3_mprintf("no such vfs: %s", zVfs);
3070     rc = SQLITE_ERROR;
3071   }
3072  parse_uri_out:
3073   if( rc!=SQLITE_OK ){
3074     sqlite3_free_filename(zFile);
3075     zFile = 0;
3076   }
3077   *pFlags = flags;
3078   *pzFile = zFile;
3079   return rc;
3080 }
3081 
3082 /*
3083 ** This routine does the core work of extracting URI parameters from a
3084 ** database filename for the sqlite3_uri_parameter() interface.
3085 */
3086 static const char *uriParameter(const char *zFilename, const char *zParam){
3087   zFilename += sqlite3Strlen30(zFilename) + 1;
3088   while( zFilename[0] ){
3089     int x = strcmp(zFilename, zParam);
3090     zFilename += sqlite3Strlen30(zFilename) + 1;
3091     if( x==0 ) return zFilename;
3092     zFilename += sqlite3Strlen30(zFilename) + 1;
3093   }
3094   return 0;
3095 }
3096 
3097 
3098 
3099 /*
3100 ** This routine does the work of opening a database on behalf of
3101 ** sqlite3_open() and sqlite3_open16(). The database filename "zFilename"
3102 ** is UTF-8 encoded.
3103 */
3104 static int openDatabase(
3105   const char *zFilename, /* Database filename UTF-8 encoded */
3106   sqlite3 **ppDb,        /* OUT: Returned database handle */
3107   unsigned int flags,    /* Operational flags */
3108   const char *zVfs       /* Name of the VFS to use */
3109 ){
3110   sqlite3 *db;                    /* Store allocated handle here */
3111   int rc;                         /* Return code */
3112   int isThreadsafe;               /* True for threadsafe connections */
3113   char *zOpen = 0;                /* Filename argument to pass to BtreeOpen() */
3114   char *zErrMsg = 0;              /* Error message from sqlite3ParseUri() */
3115   int i;                          /* Loop counter */
3116 
3117 #ifdef SQLITE_ENABLE_API_ARMOR
3118   if( ppDb==0 ) return SQLITE_MISUSE_BKPT;
3119 #endif
3120   *ppDb = 0;
3121 #ifndef SQLITE_OMIT_AUTOINIT
3122   rc = sqlite3_initialize();
3123   if( rc ) return rc;
3124 #endif
3125 
3126   if( sqlite3GlobalConfig.bCoreMutex==0 ){
3127     isThreadsafe = 0;
3128   }else if( flags & SQLITE_OPEN_NOMUTEX ){
3129     isThreadsafe = 0;
3130   }else if( flags & SQLITE_OPEN_FULLMUTEX ){
3131     isThreadsafe = 1;
3132   }else{
3133     isThreadsafe = sqlite3GlobalConfig.bFullMutex;
3134   }
3135 
3136   if( flags & SQLITE_OPEN_PRIVATECACHE ){
3137     flags &= ~SQLITE_OPEN_SHAREDCACHE;
3138   }else if( sqlite3GlobalConfig.sharedCacheEnabled ){
3139     flags |= SQLITE_OPEN_SHAREDCACHE;
3140   }
3141 
3142   /* Remove harmful bits from the flags parameter
3143   **
3144   ** The SQLITE_OPEN_NOMUTEX and SQLITE_OPEN_FULLMUTEX flags were
3145   ** dealt with in the previous code block.  Besides these, the only
3146   ** valid input flags for sqlite3_open_v2() are SQLITE_OPEN_READONLY,
3147   ** SQLITE_OPEN_READWRITE, SQLITE_OPEN_CREATE, SQLITE_OPEN_SHAREDCACHE,
3148   ** SQLITE_OPEN_PRIVATECACHE, and some reserved bits.  Silently mask
3149   ** off all other flags.
3150   */
3151   flags &=  ~( SQLITE_OPEN_DELETEONCLOSE |
3152                SQLITE_OPEN_MAIN_DB |
3153                SQLITE_OPEN_TEMP_DB |
3154                SQLITE_OPEN_TRANSIENT_DB |
3155                SQLITE_OPEN_MAIN_JOURNAL |
3156                SQLITE_OPEN_TEMP_JOURNAL |
3157                SQLITE_OPEN_SUBJOURNAL |
3158                SQLITE_OPEN_SUPER_JOURNAL |
3159                SQLITE_OPEN_NOMUTEX |
3160                SQLITE_OPEN_FULLMUTEX |
3161                SQLITE_OPEN_WAL
3162              );
3163 
3164   /* Allocate the sqlite data structure */
3165   db = sqlite3MallocZero( sizeof(sqlite3) );
3166   if( db==0 ) goto opendb_out;
3167   if( isThreadsafe
3168 #ifdef SQLITE_ENABLE_MULTITHREADED_CHECKS
3169    || sqlite3GlobalConfig.bCoreMutex
3170 #endif
3171   ){
3172     db->mutex = sqlite3MutexAlloc(SQLITE_MUTEX_RECURSIVE);
3173     if( db->mutex==0 ){
3174       sqlite3_free(db);
3175       db = 0;
3176       goto opendb_out;
3177     }
3178     if( isThreadsafe==0 ){
3179       sqlite3MutexWarnOnContention(db->mutex);
3180     }
3181   }
3182   sqlite3_mutex_enter(db->mutex);
3183   db->errMask = 0xff;
3184   db->nDb = 2;
3185   db->magic = SQLITE_MAGIC_BUSY;
3186   db->aDb = db->aDbStatic;
3187   db->lookaside.bDisable = 1;
3188   db->lookaside.sz = 0;
3189 
3190   assert( sizeof(db->aLimit)==sizeof(aHardLimit) );
3191   memcpy(db->aLimit, aHardLimit, sizeof(db->aLimit));
3192   db->aLimit[SQLITE_LIMIT_WORKER_THREADS] = SQLITE_DEFAULT_WORKER_THREADS;
3193   db->autoCommit = 1;
3194   db->nextAutovac = -1;
3195   db->szMmap = sqlite3GlobalConfig.szMmap;
3196   db->nextPagesize = 0;
3197   db->nMaxSorterMmap = 0x7FFFFFFF;
3198   db->flags |= SQLITE_ShortColNames
3199                  | SQLITE_EnableTrigger
3200                  | SQLITE_EnableView
3201                  | SQLITE_CacheSpill
3202 #if !defined(SQLITE_TRUSTED_SCHEMA) || SQLITE_TRUSTED_SCHEMA+0!=0
3203                  | SQLITE_TrustedSchema
3204 #endif
3205 /* The SQLITE_DQS compile-time option determines the default settings
3206 ** for SQLITE_DBCONFIG_DQS_DDL and SQLITE_DBCONFIG_DQS_DML.
3207 **
3208 **    SQLITE_DQS     SQLITE_DBCONFIG_DQS_DDL    SQLITE_DBCONFIG_DQS_DML
3209 **    ----------     -----------------------    -----------------------
3210 **     undefined               on                          on
3211 **         3                   on                          on
3212 **         2                   on                         off
3213 **         1                  off                          on
3214 **         0                  off                         off
3215 **
3216 ** Legacy behavior is 3 (double-quoted string literals are allowed anywhere)
3217 ** and so that is the default.  But developers are encouranged to use
3218 ** -DSQLITE_DQS=0 (best) or -DSQLITE_DQS=1 (second choice) if possible.
3219 */
3220 #if !defined(SQLITE_DQS)
3221 # define SQLITE_DQS 3
3222 #endif
3223 #if (SQLITE_DQS&1)==1
3224                  | SQLITE_DqsDML
3225 #endif
3226 #if (SQLITE_DQS&2)==2
3227                  | SQLITE_DqsDDL
3228 #endif
3229 
3230 #if !defined(SQLITE_DEFAULT_AUTOMATIC_INDEX) || SQLITE_DEFAULT_AUTOMATIC_INDEX
3231                  | SQLITE_AutoIndex
3232 #endif
3233 #if SQLITE_DEFAULT_CKPTFULLFSYNC
3234                  | SQLITE_CkptFullFSync
3235 #endif
3236 #if SQLITE_DEFAULT_FILE_FORMAT<4
3237                  | SQLITE_LegacyFileFmt
3238 #endif
3239 #ifdef SQLITE_ENABLE_LOAD_EXTENSION
3240                  | SQLITE_LoadExtension
3241 #endif
3242 #if SQLITE_DEFAULT_RECURSIVE_TRIGGERS
3243                  | SQLITE_RecTriggers
3244 #endif
3245 #if defined(SQLITE_DEFAULT_FOREIGN_KEYS) && SQLITE_DEFAULT_FOREIGN_KEYS
3246                  | SQLITE_ForeignKeys
3247 #endif
3248 #if defined(SQLITE_REVERSE_UNORDERED_SELECTS)
3249                  | SQLITE_ReverseOrder
3250 #endif
3251 #if defined(SQLITE_ENABLE_OVERSIZE_CELL_CHECK)
3252                  | SQLITE_CellSizeCk
3253 #endif
3254 #if defined(SQLITE_ENABLE_FTS3_TOKENIZER)
3255                  | SQLITE_Fts3Tokenizer
3256 #endif
3257 #if defined(SQLITE_ENABLE_QPSG)
3258                  | SQLITE_EnableQPSG
3259 #endif
3260 #if defined(SQLITE_DEFAULT_DEFENSIVE)
3261                  | SQLITE_Defensive
3262 #endif
3263 #if defined(SQLITE_DEFAULT_LEGACY_ALTER_TABLE)
3264                  | SQLITE_LegacyAlter
3265 #endif
3266       ;
3267   sqlite3HashInit(&db->aCollSeq);
3268 #ifndef SQLITE_OMIT_VIRTUALTABLE
3269   sqlite3HashInit(&db->aModule);
3270 #endif
3271 
3272   /* Add the default collation sequence BINARY. BINARY works for both UTF-8
3273   ** and UTF-16, so add a version for each to avoid any unnecessary
3274   ** conversions. The only error that can occur here is a malloc() failure.
3275   **
3276   ** EVIDENCE-OF: R-52786-44878 SQLite defines three built-in collating
3277   ** functions:
3278   */
3279   createCollation(db, sqlite3StrBINARY, SQLITE_UTF8, 0, binCollFunc, 0);
3280   createCollation(db, sqlite3StrBINARY, SQLITE_UTF16BE, 0, binCollFunc, 0);
3281   createCollation(db, sqlite3StrBINARY, SQLITE_UTF16LE, 0, binCollFunc, 0);
3282   createCollation(db, "NOCASE", SQLITE_UTF8, 0, nocaseCollatingFunc, 0);
3283   createCollation(db, "RTRIM", SQLITE_UTF8, 0, rtrimCollFunc, 0);
3284   if( db->mallocFailed ){
3285     goto opendb_out;
3286   }
3287 
3288   /* Parse the filename/URI argument
3289   **
3290   ** Only allow sensible combinations of bits in the flags argument.
3291   ** Throw an error if any non-sense combination is used.  If we
3292   ** do not block illegal combinations here, it could trigger
3293   ** assert() statements in deeper layers.  Sensible combinations
3294   ** are:
3295   **
3296   **  1:  SQLITE_OPEN_READONLY
3297   **  2:  SQLITE_OPEN_READWRITE
3298   **  6:  SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE
3299   */
3300   db->openFlags = flags;
3301   assert( SQLITE_OPEN_READONLY  == 0x01 );
3302   assert( SQLITE_OPEN_READWRITE == 0x02 );
3303   assert( SQLITE_OPEN_CREATE    == 0x04 );
3304   testcase( (1<<(flags&7))==0x02 ); /* READONLY */
3305   testcase( (1<<(flags&7))==0x04 ); /* READWRITE */
3306   testcase( (1<<(flags&7))==0x40 ); /* READWRITE | CREATE */
3307   if( ((1<<(flags&7)) & 0x46)==0 ){
3308     rc = SQLITE_MISUSE_BKPT;  /* IMP: R-18321-05872 */
3309   }else{
3310     rc = sqlite3ParseUri(zVfs, zFilename, &flags, &db->pVfs, &zOpen, &zErrMsg);
3311   }
3312   if( rc!=SQLITE_OK ){
3313     if( rc==SQLITE_NOMEM ) sqlite3OomFault(db);
3314     sqlite3ErrorWithMsg(db, rc, zErrMsg ? "%s" : 0, zErrMsg);
3315     sqlite3_free(zErrMsg);
3316     goto opendb_out;
3317   }
3318 
3319   /* Open the backend database driver */
3320   rc = sqlite3BtreeOpen(db->pVfs, zOpen, db, &db->aDb[0].pBt, 0,
3321                         flags | SQLITE_OPEN_MAIN_DB);
3322   if( rc!=SQLITE_OK ){
3323     if( rc==SQLITE_IOERR_NOMEM ){
3324       rc = SQLITE_NOMEM_BKPT;
3325     }
3326     sqlite3Error(db, rc);
3327     goto opendb_out;
3328   }
3329   sqlite3BtreeEnter(db->aDb[0].pBt);
3330   db->aDb[0].pSchema = sqlite3SchemaGet(db, db->aDb[0].pBt);
3331   if( !db->mallocFailed ){
3332     sqlite3SetTextEncoding(db, SCHEMA_ENC(db));
3333   }
3334   sqlite3BtreeLeave(db->aDb[0].pBt);
3335   db->aDb[1].pSchema = sqlite3SchemaGet(db, 0);
3336 
3337   /* The default safety_level for the main database is FULL; for the temp
3338   ** database it is OFF. This matches the pager layer defaults.
3339   */
3340   db->aDb[0].zDbSName = "main";
3341   db->aDb[0].safety_level = SQLITE_DEFAULT_SYNCHRONOUS+1;
3342   db->aDb[1].zDbSName = "temp";
3343   db->aDb[1].safety_level = PAGER_SYNCHRONOUS_OFF;
3344 
3345   db->magic = SQLITE_MAGIC_OPEN;
3346   if( db->mallocFailed ){
3347     goto opendb_out;
3348   }
3349 
3350   /* Register all built-in functions, but do not attempt to read the
3351   ** database schema yet. This is delayed until the first time the database
3352   ** is accessed.
3353   */
3354   sqlite3Error(db, SQLITE_OK);
3355   sqlite3RegisterPerConnectionBuiltinFunctions(db);
3356   rc = sqlite3_errcode(db);
3357 
3358 
3359   /* Load compiled-in extensions */
3360   for(i=0; rc==SQLITE_OK && i<ArraySize(sqlite3BuiltinExtensions); i++){
3361     rc = sqlite3BuiltinExtensions[i](db);
3362   }
3363 
3364   /* Load automatic extensions - extensions that have been registered
3365   ** using the sqlite3_automatic_extension() API.
3366   */
3367   if( rc==SQLITE_OK ){
3368     sqlite3AutoLoadExtensions(db);
3369     rc = sqlite3_errcode(db);
3370     if( rc!=SQLITE_OK ){
3371       goto opendb_out;
3372     }
3373   }
3374 
3375 #ifdef SQLITE_ENABLE_INTERNAL_FUNCTIONS
3376   /* Testing use only!!! The -DSQLITE_ENABLE_INTERNAL_FUNCTIONS=1 compile-time
3377   ** option gives access to internal functions by default.
3378   ** Testing use only!!! */
3379   db->mDbFlags |= DBFLAG_InternalFunc;
3380 #endif
3381 
3382   /* -DSQLITE_DEFAULT_LOCKING_MODE=1 makes EXCLUSIVE the default locking
3383   ** mode.  -DSQLITE_DEFAULT_LOCKING_MODE=0 make NORMAL the default locking
3384   ** mode.  Doing nothing at all also makes NORMAL the default.
3385   */
3386 #ifdef SQLITE_DEFAULT_LOCKING_MODE
3387   db->dfltLockMode = SQLITE_DEFAULT_LOCKING_MODE;
3388   sqlite3PagerLockingMode(sqlite3BtreePager(db->aDb[0].pBt),
3389                           SQLITE_DEFAULT_LOCKING_MODE);
3390 #endif
3391 
3392   if( rc ) sqlite3Error(db, rc);
3393 
3394   /* Enable the lookaside-malloc subsystem */
3395   setupLookaside(db, 0, sqlite3GlobalConfig.szLookaside,
3396                         sqlite3GlobalConfig.nLookaside);
3397 
3398   sqlite3_wal_autocheckpoint(db, SQLITE_DEFAULT_WAL_AUTOCHECKPOINT);
3399 
3400 opendb_out:
3401   if( db ){
3402     assert( db->mutex!=0 || isThreadsafe==0
3403            || sqlite3GlobalConfig.bFullMutex==0 );
3404     sqlite3_mutex_leave(db->mutex);
3405   }
3406   rc = sqlite3_errcode(db);
3407   assert( db!=0 || rc==SQLITE_NOMEM );
3408   if( rc==SQLITE_NOMEM ){
3409     sqlite3_close(db);
3410     db = 0;
3411   }else if( rc!=SQLITE_OK ){
3412     db->magic = SQLITE_MAGIC_SICK;
3413   }
3414   *ppDb = db;
3415 #ifdef SQLITE_ENABLE_SQLLOG
3416   if( sqlite3GlobalConfig.xSqllog ){
3417     /* Opening a db handle. Fourth parameter is passed 0. */
3418     void *pArg = sqlite3GlobalConfig.pSqllogArg;
3419     sqlite3GlobalConfig.xSqllog(pArg, db, zFilename, 0);
3420   }
3421 #endif
3422   sqlite3_free_filename(zOpen);
3423   return rc & 0xff;
3424 }
3425 
3426 
3427 /*
3428 ** Open a new database handle.
3429 */
3430 int sqlite3_open(
3431   const char *zFilename,
3432   sqlite3 **ppDb
3433 ){
3434   return openDatabase(zFilename, ppDb,
3435                       SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
3436 }
3437 int sqlite3_open_v2(
3438   const char *filename,   /* Database filename (UTF-8) */
3439   sqlite3 **ppDb,         /* OUT: SQLite db handle */
3440   int flags,              /* Flags */
3441   const char *zVfs        /* Name of VFS module to use */
3442 ){
3443   return openDatabase(filename, ppDb, (unsigned int)flags, zVfs);
3444 }
3445 
3446 #ifndef SQLITE_OMIT_UTF16
3447 /*
3448 ** Open a new database handle.
3449 */
3450 int sqlite3_open16(
3451   const void *zFilename,
3452   sqlite3 **ppDb
3453 ){
3454   char const *zFilename8;   /* zFilename encoded in UTF-8 instead of UTF-16 */
3455   sqlite3_value *pVal;
3456   int rc;
3457 
3458 #ifdef SQLITE_ENABLE_API_ARMOR
3459   if( ppDb==0 ) return SQLITE_MISUSE_BKPT;
3460 #endif
3461   *ppDb = 0;
3462 #ifndef SQLITE_OMIT_AUTOINIT
3463   rc = sqlite3_initialize();
3464   if( rc ) return rc;
3465 #endif
3466   if( zFilename==0 ) zFilename = "\000\000";
3467   pVal = sqlite3ValueNew(0);
3468   sqlite3ValueSetStr(pVal, -1, zFilename, SQLITE_UTF16NATIVE, SQLITE_STATIC);
3469   zFilename8 = sqlite3ValueText(pVal, SQLITE_UTF8);
3470   if( zFilename8 ){
3471     rc = openDatabase(zFilename8, ppDb,
3472                       SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
3473     assert( *ppDb || rc==SQLITE_NOMEM );
3474     if( rc==SQLITE_OK && !DbHasProperty(*ppDb, 0, DB_SchemaLoaded) ){
3475       SCHEMA_ENC(*ppDb) = ENC(*ppDb) = SQLITE_UTF16NATIVE;
3476     }
3477   }else{
3478     rc = SQLITE_NOMEM_BKPT;
3479   }
3480   sqlite3ValueFree(pVal);
3481 
3482   return rc & 0xff;
3483 }
3484 #endif /* SQLITE_OMIT_UTF16 */
3485 
3486 /*
3487 ** Register a new collation sequence with the database handle db.
3488 */
3489 int sqlite3_create_collation(
3490   sqlite3* db,
3491   const char *zName,
3492   int enc,
3493   void* pCtx,
3494   int(*xCompare)(void*,int,const void*,int,const void*)
3495 ){
3496   return sqlite3_create_collation_v2(db, zName, enc, pCtx, xCompare, 0);
3497 }
3498 
3499 /*
3500 ** Register a new collation sequence with the database handle db.
3501 */
3502 int sqlite3_create_collation_v2(
3503   sqlite3* db,
3504   const char *zName,
3505   int enc,
3506   void* pCtx,
3507   int(*xCompare)(void*,int,const void*,int,const void*),
3508   void(*xDel)(void*)
3509 ){
3510   int rc;
3511 
3512 #ifdef SQLITE_ENABLE_API_ARMOR
3513   if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
3514 #endif
3515   sqlite3_mutex_enter(db->mutex);
3516   assert( !db->mallocFailed );
3517   rc = createCollation(db, zName, (u8)enc, pCtx, xCompare, xDel);
3518   rc = sqlite3ApiExit(db, rc);
3519   sqlite3_mutex_leave(db->mutex);
3520   return rc;
3521 }
3522 
3523 #ifndef SQLITE_OMIT_UTF16
3524 /*
3525 ** Register a new collation sequence with the database handle db.
3526 */
3527 int sqlite3_create_collation16(
3528   sqlite3* db,
3529   const void *zName,
3530   int enc,
3531   void* pCtx,
3532   int(*xCompare)(void*,int,const void*,int,const void*)
3533 ){
3534   int rc = SQLITE_OK;
3535   char *zName8;
3536 
3537 #ifdef SQLITE_ENABLE_API_ARMOR
3538   if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
3539 #endif
3540   sqlite3_mutex_enter(db->mutex);
3541   assert( !db->mallocFailed );
3542   zName8 = sqlite3Utf16to8(db, zName, -1, SQLITE_UTF16NATIVE);
3543   if( zName8 ){
3544     rc = createCollation(db, zName8, (u8)enc, pCtx, xCompare, 0);
3545     sqlite3DbFree(db, zName8);
3546   }
3547   rc = sqlite3ApiExit(db, rc);
3548   sqlite3_mutex_leave(db->mutex);
3549   return rc;
3550 }
3551 #endif /* SQLITE_OMIT_UTF16 */
3552 
3553 /*
3554 ** Register a collation sequence factory callback with the database handle
3555 ** db. Replace any previously installed collation sequence factory.
3556 */
3557 int sqlite3_collation_needed(
3558   sqlite3 *db,
3559   void *pCollNeededArg,
3560   void(*xCollNeeded)(void*,sqlite3*,int eTextRep,const char*)
3561 ){
3562 #ifdef SQLITE_ENABLE_API_ARMOR
3563   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3564 #endif
3565   sqlite3_mutex_enter(db->mutex);
3566   db->xCollNeeded = xCollNeeded;
3567   db->xCollNeeded16 = 0;
3568   db->pCollNeededArg = pCollNeededArg;
3569   sqlite3_mutex_leave(db->mutex);
3570   return SQLITE_OK;
3571 }
3572 
3573 #ifndef SQLITE_OMIT_UTF16
3574 /*
3575 ** Register a collation sequence factory callback with the database handle
3576 ** db. Replace any previously installed collation sequence factory.
3577 */
3578 int sqlite3_collation_needed16(
3579   sqlite3 *db,
3580   void *pCollNeededArg,
3581   void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*)
3582 ){
3583 #ifdef SQLITE_ENABLE_API_ARMOR
3584   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3585 #endif
3586   sqlite3_mutex_enter(db->mutex);
3587   db->xCollNeeded = 0;
3588   db->xCollNeeded16 = xCollNeeded16;
3589   db->pCollNeededArg = pCollNeededArg;
3590   sqlite3_mutex_leave(db->mutex);
3591   return SQLITE_OK;
3592 }
3593 #endif /* SQLITE_OMIT_UTF16 */
3594 
3595 #ifndef SQLITE_OMIT_DEPRECATED
3596 /*
3597 ** This function is now an anachronism. It used to be used to recover from a
3598 ** malloc() failure, but SQLite now does this automatically.
3599 */
3600 int sqlite3_global_recover(void){
3601   return SQLITE_OK;
3602 }
3603 #endif
3604 
3605 /*
3606 ** Test to see whether or not the database connection is in autocommit
3607 ** mode.  Return TRUE if it is and FALSE if not.  Autocommit mode is on
3608 ** by default.  Autocommit is disabled by a BEGIN statement and reenabled
3609 ** by the next COMMIT or ROLLBACK.
3610 */
3611 int sqlite3_get_autocommit(sqlite3 *db){
3612 #ifdef SQLITE_ENABLE_API_ARMOR
3613   if( !sqlite3SafetyCheckOk(db) ){
3614     (void)SQLITE_MISUSE_BKPT;
3615     return 0;
3616   }
3617 #endif
3618   return db->autoCommit;
3619 }
3620 
3621 /*
3622 ** The following routines are substitutes for constants SQLITE_CORRUPT,
3623 ** SQLITE_MISUSE, SQLITE_CANTOPEN, SQLITE_NOMEM and possibly other error
3624 ** constants.  They serve two purposes:
3625 **
3626 **   1.  Serve as a convenient place to set a breakpoint in a debugger
3627 **       to detect when version error conditions occurs.
3628 **
3629 **   2.  Invoke sqlite3_log() to provide the source code location where
3630 **       a low-level error is first detected.
3631 */
3632 int sqlite3ReportError(int iErr, int lineno, const char *zType){
3633   sqlite3_log(iErr, "%s at line %d of [%.10s]",
3634               zType, lineno, 20+sqlite3_sourceid());
3635   return iErr;
3636 }
3637 int sqlite3CorruptError(int lineno){
3638   testcase( sqlite3GlobalConfig.xLog!=0 );
3639   return sqlite3ReportError(SQLITE_CORRUPT, lineno, "database corruption");
3640 }
3641 int sqlite3MisuseError(int lineno){
3642   testcase( sqlite3GlobalConfig.xLog!=0 );
3643   return sqlite3ReportError(SQLITE_MISUSE, lineno, "misuse");
3644 }
3645 int sqlite3CantopenError(int lineno){
3646   testcase( sqlite3GlobalConfig.xLog!=0 );
3647   return sqlite3ReportError(SQLITE_CANTOPEN, lineno, "cannot open file");
3648 }
3649 #if defined(SQLITE_DEBUG) || defined(SQLITE_ENABLE_CORRUPT_PGNO)
3650 int sqlite3CorruptPgnoError(int lineno, Pgno pgno){
3651   char zMsg[100];
3652   sqlite3_snprintf(sizeof(zMsg), zMsg, "database corruption page %d", pgno);
3653   testcase( sqlite3GlobalConfig.xLog!=0 );
3654   return sqlite3ReportError(SQLITE_CORRUPT, lineno, zMsg);
3655 }
3656 #endif
3657 #ifdef SQLITE_DEBUG
3658 int sqlite3NomemError(int lineno){
3659   testcase( sqlite3GlobalConfig.xLog!=0 );
3660   return sqlite3ReportError(SQLITE_NOMEM, lineno, "OOM");
3661 }
3662 int sqlite3IoerrnomemError(int lineno){
3663   testcase( sqlite3GlobalConfig.xLog!=0 );
3664   return sqlite3ReportError(SQLITE_IOERR_NOMEM, lineno, "I/O OOM error");
3665 }
3666 #endif
3667 
3668 #ifndef SQLITE_OMIT_DEPRECATED
3669 /*
3670 ** This is a convenience routine that makes sure that all thread-specific
3671 ** data for this thread has been deallocated.
3672 **
3673 ** SQLite no longer uses thread-specific data so this routine is now a
3674 ** no-op.  It is retained for historical compatibility.
3675 */
3676 void sqlite3_thread_cleanup(void){
3677 }
3678 #endif
3679 
3680 /*
3681 ** Return meta information about a specific column of a database table.
3682 ** See comment in sqlite3.h (sqlite.h.in) for details.
3683 */
3684 int sqlite3_table_column_metadata(
3685   sqlite3 *db,                /* Connection handle */
3686   const char *zDbName,        /* Database name or NULL */
3687   const char *zTableName,     /* Table name */
3688   const char *zColumnName,    /* Column name */
3689   char const **pzDataType,    /* OUTPUT: Declared data type */
3690   char const **pzCollSeq,     /* OUTPUT: Collation sequence name */
3691   int *pNotNull,              /* OUTPUT: True if NOT NULL constraint exists */
3692   int *pPrimaryKey,           /* OUTPUT: True if column part of PK */
3693   int *pAutoinc               /* OUTPUT: True if column is auto-increment */
3694 ){
3695   int rc;
3696   char *zErrMsg = 0;
3697   Table *pTab = 0;
3698   Column *pCol = 0;
3699   int iCol = 0;
3700   char const *zDataType = 0;
3701   char const *zCollSeq = 0;
3702   int notnull = 0;
3703   int primarykey = 0;
3704   int autoinc = 0;
3705 
3706 
3707 #ifdef SQLITE_ENABLE_API_ARMOR
3708   if( !sqlite3SafetyCheckOk(db) || zTableName==0 ){
3709     return SQLITE_MISUSE_BKPT;
3710   }
3711 #endif
3712 
3713   /* Ensure the database schema has been loaded */
3714   sqlite3_mutex_enter(db->mutex);
3715   sqlite3BtreeEnterAll(db);
3716   rc = sqlite3Init(db, &zErrMsg);
3717   if( SQLITE_OK!=rc ){
3718     goto error_out;
3719   }
3720 
3721   /* Locate the table in question */
3722   pTab = sqlite3FindTable(db, zTableName, zDbName);
3723   if( !pTab || pTab->pSelect ){
3724     pTab = 0;
3725     goto error_out;
3726   }
3727 
3728   /* Find the column for which info is requested */
3729   if( zColumnName==0 ){
3730     /* Query for existance of table only */
3731   }else{
3732     for(iCol=0; iCol<pTab->nCol; iCol++){
3733       pCol = &pTab->aCol[iCol];
3734       if( 0==sqlite3StrICmp(pCol->zName, zColumnName) ){
3735         break;
3736       }
3737     }
3738     if( iCol==pTab->nCol ){
3739       if( HasRowid(pTab) && sqlite3IsRowid(zColumnName) ){
3740         iCol = pTab->iPKey;
3741         pCol = iCol>=0 ? &pTab->aCol[iCol] : 0;
3742       }else{
3743         pTab = 0;
3744         goto error_out;
3745       }
3746     }
3747   }
3748 
3749   /* The following block stores the meta information that will be returned
3750   ** to the caller in local variables zDataType, zCollSeq, notnull, primarykey
3751   ** and autoinc. At this point there are two possibilities:
3752   **
3753   **     1. The specified column name was rowid", "oid" or "_rowid_"
3754   **        and there is no explicitly declared IPK column.
3755   **
3756   **     2. The table is not a view and the column name identified an
3757   **        explicitly declared column. Copy meta information from *pCol.
3758   */
3759   if( pCol ){
3760     zDataType = sqlite3ColumnType(pCol,0);
3761     zCollSeq = pCol->zColl;
3762     notnull = pCol->notNull!=0;
3763     primarykey  = (pCol->colFlags & COLFLAG_PRIMKEY)!=0;
3764     autoinc = pTab->iPKey==iCol && (pTab->tabFlags & TF_Autoincrement)!=0;
3765   }else{
3766     zDataType = "INTEGER";
3767     primarykey = 1;
3768   }
3769   if( !zCollSeq ){
3770     zCollSeq = sqlite3StrBINARY;
3771   }
3772 
3773 error_out:
3774   sqlite3BtreeLeaveAll(db);
3775 
3776   /* Whether the function call succeeded or failed, set the output parameters
3777   ** to whatever their local counterparts contain. If an error did occur,
3778   ** this has the effect of zeroing all output parameters.
3779   */
3780   if( pzDataType ) *pzDataType = zDataType;
3781   if( pzCollSeq ) *pzCollSeq = zCollSeq;
3782   if( pNotNull ) *pNotNull = notnull;
3783   if( pPrimaryKey ) *pPrimaryKey = primarykey;
3784   if( pAutoinc ) *pAutoinc = autoinc;
3785 
3786   if( SQLITE_OK==rc && !pTab ){
3787     sqlite3DbFree(db, zErrMsg);
3788     zErrMsg = sqlite3MPrintf(db, "no such table column: %s.%s", zTableName,
3789         zColumnName);
3790     rc = SQLITE_ERROR;
3791   }
3792   sqlite3ErrorWithMsg(db, rc, (zErrMsg?"%s":0), zErrMsg);
3793   sqlite3DbFree(db, zErrMsg);
3794   rc = sqlite3ApiExit(db, rc);
3795   sqlite3_mutex_leave(db->mutex);
3796   return rc;
3797 }
3798 
3799 /*
3800 ** Sleep for a little while.  Return the amount of time slept.
3801 */
3802 int sqlite3_sleep(int ms){
3803   sqlite3_vfs *pVfs;
3804   int rc;
3805   pVfs = sqlite3_vfs_find(0);
3806   if( pVfs==0 ) return 0;
3807 
3808   /* This function works in milliseconds, but the underlying OsSleep()
3809   ** API uses microseconds. Hence the 1000's.
3810   */
3811   rc = (sqlite3OsSleep(pVfs, 1000*ms)/1000);
3812   return rc;
3813 }
3814 
3815 /*
3816 ** Enable or disable the extended result codes.
3817 */
3818 int sqlite3_extended_result_codes(sqlite3 *db, int onoff){
3819 #ifdef SQLITE_ENABLE_API_ARMOR
3820   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3821 #endif
3822   sqlite3_mutex_enter(db->mutex);
3823   db->errMask = onoff ? 0xffffffff : 0xff;
3824   sqlite3_mutex_leave(db->mutex);
3825   return SQLITE_OK;
3826 }
3827 
3828 /*
3829 ** Invoke the xFileControl method on a particular database.
3830 */
3831 int sqlite3_file_control(sqlite3 *db, const char *zDbName, int op, void *pArg){
3832   int rc = SQLITE_ERROR;
3833   Btree *pBtree;
3834 
3835 #ifdef SQLITE_ENABLE_API_ARMOR
3836   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3837 #endif
3838   sqlite3_mutex_enter(db->mutex);
3839   pBtree = sqlite3DbNameToBtree(db, zDbName);
3840   if( pBtree ){
3841     Pager *pPager;
3842     sqlite3_file *fd;
3843     sqlite3BtreeEnter(pBtree);
3844     pPager = sqlite3BtreePager(pBtree);
3845     assert( pPager!=0 );
3846     fd = sqlite3PagerFile(pPager);
3847     assert( fd!=0 );
3848     if( op==SQLITE_FCNTL_FILE_POINTER ){
3849       *(sqlite3_file**)pArg = fd;
3850       rc = SQLITE_OK;
3851     }else if( op==SQLITE_FCNTL_VFS_POINTER ){
3852       *(sqlite3_vfs**)pArg = sqlite3PagerVfs(pPager);
3853       rc = SQLITE_OK;
3854     }else if( op==SQLITE_FCNTL_JOURNAL_POINTER ){
3855       *(sqlite3_file**)pArg = sqlite3PagerJrnlFile(pPager);
3856       rc = SQLITE_OK;
3857     }else if( op==SQLITE_FCNTL_DATA_VERSION ){
3858       *(unsigned int*)pArg = sqlite3PagerDataVersion(pPager);
3859       rc = SQLITE_OK;
3860     }else if( op==SQLITE_FCNTL_RESERVE_BYTES ){
3861       int iNew = *(int*)pArg;
3862       *(int*)pArg = sqlite3BtreeGetRequestedReserve(pBtree);
3863       if( iNew>=0 && iNew<=255 ){
3864         sqlite3BtreeSetPageSize(pBtree, 0, iNew, 0);
3865       }
3866       rc = SQLITE_OK;
3867     }else{
3868       int nSave = db->busyHandler.nBusy;
3869       rc = sqlite3OsFileControl(fd, op, pArg);
3870       db->busyHandler.nBusy = nSave;
3871     }
3872     sqlite3BtreeLeave(pBtree);
3873   }
3874   sqlite3_mutex_leave(db->mutex);
3875   return rc;
3876 }
3877 
3878 /*
3879 ** Interface to the testing logic.
3880 */
3881 int sqlite3_test_control(int op, ...){
3882   int rc = 0;
3883 #ifdef SQLITE_UNTESTABLE
3884   UNUSED_PARAMETER(op);
3885 #else
3886   va_list ap;
3887   va_start(ap, op);
3888   switch( op ){
3889 
3890     /*
3891     ** Save the current state of the PRNG.
3892     */
3893     case SQLITE_TESTCTRL_PRNG_SAVE: {
3894       sqlite3PrngSaveState();
3895       break;
3896     }
3897 
3898     /*
3899     ** Restore the state of the PRNG to the last state saved using
3900     ** PRNG_SAVE.  If PRNG_SAVE has never before been called, then
3901     ** this verb acts like PRNG_RESET.
3902     */
3903     case SQLITE_TESTCTRL_PRNG_RESTORE: {
3904       sqlite3PrngRestoreState();
3905       break;
3906     }
3907 
3908     /*  sqlite3_test_control(SQLITE_TESTCTRL_PRNG_SEED, int x, sqlite3 *db);
3909     **
3910     ** Control the seed for the pseudo-random number generator (PRNG) that
3911     ** is built into SQLite.  Cases:
3912     **
3913     **    x!=0 && db!=0       Seed the PRNG to the current value of the
3914     **                        schema cookie in the main database for db, or
3915     **                        x if the schema cookie is zero.  This case
3916     **                        is convenient to use with database fuzzers
3917     **                        as it allows the fuzzer some control over the
3918     **                        the PRNG seed.
3919     **
3920     **    x!=0 && db==0       Seed the PRNG to the value of x.
3921     **
3922     **    x==0 && db==0       Revert to default behavior of using the
3923     **                        xRandomness method on the primary VFS.
3924     **
3925     ** This test-control also resets the PRNG so that the new seed will
3926     ** be used for the next call to sqlite3_randomness().
3927     */
3928 #ifndef SQLITE_OMIT_WSD
3929     case SQLITE_TESTCTRL_PRNG_SEED: {
3930       int x = va_arg(ap, int);
3931       int y;
3932       sqlite3 *db = va_arg(ap, sqlite3*);
3933       assert( db==0 || db->aDb[0].pSchema!=0 );
3934       if( db && (y = db->aDb[0].pSchema->schema_cookie)!=0 ){ x = y; }
3935       sqlite3Config.iPrngSeed = x;
3936       sqlite3_randomness(0,0);
3937       break;
3938     }
3939 #endif
3940 
3941     /*
3942     **  sqlite3_test_control(BITVEC_TEST, size, program)
3943     **
3944     ** Run a test against a Bitvec object of size.  The program argument
3945     ** is an array of integers that defines the test.  Return -1 on a
3946     ** memory allocation error, 0 on success, or non-zero for an error.
3947     ** See the sqlite3BitvecBuiltinTest() for additional information.
3948     */
3949     case SQLITE_TESTCTRL_BITVEC_TEST: {
3950       int sz = va_arg(ap, int);
3951       int *aProg = va_arg(ap, int*);
3952       rc = sqlite3BitvecBuiltinTest(sz, aProg);
3953       break;
3954     }
3955 
3956     /*
3957     **  sqlite3_test_control(FAULT_INSTALL, xCallback)
3958     **
3959     ** Arrange to invoke xCallback() whenever sqlite3FaultSim() is called,
3960     ** if xCallback is not NULL.
3961     **
3962     ** As a test of the fault simulator mechanism itself, sqlite3FaultSim(0)
3963     ** is called immediately after installing the new callback and the return
3964     ** value from sqlite3FaultSim(0) becomes the return from
3965     ** sqlite3_test_control().
3966     */
3967     case SQLITE_TESTCTRL_FAULT_INSTALL: {
3968       /* MSVC is picky about pulling func ptrs from va lists.
3969       ** http://support.microsoft.com/kb/47961
3970       ** sqlite3GlobalConfig.xTestCallback = va_arg(ap, int(*)(int));
3971       */
3972       typedef int(*TESTCALLBACKFUNC_t)(int);
3973       sqlite3GlobalConfig.xTestCallback = va_arg(ap, TESTCALLBACKFUNC_t);
3974       rc = sqlite3FaultSim(0);
3975       break;
3976     }
3977 
3978     /*
3979     **  sqlite3_test_control(BENIGN_MALLOC_HOOKS, xBegin, xEnd)
3980     **
3981     ** Register hooks to call to indicate which malloc() failures
3982     ** are benign.
3983     */
3984     case SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS: {
3985       typedef void (*void_function)(void);
3986       void_function xBenignBegin;
3987       void_function xBenignEnd;
3988       xBenignBegin = va_arg(ap, void_function);
3989       xBenignEnd = va_arg(ap, void_function);
3990       sqlite3BenignMallocHooks(xBenignBegin, xBenignEnd);
3991       break;
3992     }
3993 
3994     /*
3995     **  sqlite3_test_control(SQLITE_TESTCTRL_PENDING_BYTE, unsigned int X)
3996     **
3997     ** Set the PENDING byte to the value in the argument, if X>0.
3998     ** Make no changes if X==0.  Return the value of the pending byte
3999     ** as it existing before this routine was called.
4000     **
4001     ** IMPORTANT:  Changing the PENDING byte from 0x40000000 results in
4002     ** an incompatible database file format.  Changing the PENDING byte
4003     ** while any database connection is open results in undefined and
4004     ** deleterious behavior.
4005     */
4006     case SQLITE_TESTCTRL_PENDING_BYTE: {
4007       rc = PENDING_BYTE;
4008 #ifndef SQLITE_OMIT_WSD
4009       {
4010         unsigned int newVal = va_arg(ap, unsigned int);
4011         if( newVal ) sqlite3PendingByte = newVal;
4012       }
4013 #endif
4014       break;
4015     }
4016 
4017     /*
4018     **  sqlite3_test_control(SQLITE_TESTCTRL_ASSERT, int X)
4019     **
4020     ** This action provides a run-time test to see whether or not
4021     ** assert() was enabled at compile-time.  If X is true and assert()
4022     ** is enabled, then the return value is true.  If X is true and
4023     ** assert() is disabled, then the return value is zero.  If X is
4024     ** false and assert() is enabled, then the assertion fires and the
4025     ** process aborts.  If X is false and assert() is disabled, then the
4026     ** return value is zero.
4027     */
4028     case SQLITE_TESTCTRL_ASSERT: {
4029       volatile int x = 0;
4030       assert( /*side-effects-ok*/ (x = va_arg(ap,int))!=0 );
4031       rc = x;
4032       break;
4033     }
4034 
4035 
4036     /*
4037     **  sqlite3_test_control(SQLITE_TESTCTRL_ALWAYS, int X)
4038     **
4039     ** This action provides a run-time test to see how the ALWAYS and
4040     ** NEVER macros were defined at compile-time.
4041     **
4042     ** The return value is ALWAYS(X) if X is true, or 0 if X is false.
4043     **
4044     ** The recommended test is X==2.  If the return value is 2, that means
4045     ** ALWAYS() and NEVER() are both no-op pass-through macros, which is the
4046     ** default setting.  If the return value is 1, then ALWAYS() is either
4047     ** hard-coded to true or else it asserts if its argument is false.
4048     ** The first behavior (hard-coded to true) is the case if
4049     ** SQLITE_TESTCTRL_ASSERT shows that assert() is disabled and the second
4050     ** behavior (assert if the argument to ALWAYS() is false) is the case if
4051     ** SQLITE_TESTCTRL_ASSERT shows that assert() is enabled.
4052     **
4053     ** The run-time test procedure might look something like this:
4054     **
4055     **    if( sqlite3_test_control(SQLITE_TESTCTRL_ALWAYS, 2)==2 ){
4056     **      // ALWAYS() and NEVER() are no-op pass-through macros
4057     **    }else if( sqlite3_test_control(SQLITE_TESTCTRL_ASSERT, 1) ){
4058     **      // ALWAYS(x) asserts that x is true. NEVER(x) asserts x is false.
4059     **    }else{
4060     **      // ALWAYS(x) is a constant 1.  NEVER(x) is a constant 0.
4061     **    }
4062     */
4063     case SQLITE_TESTCTRL_ALWAYS: {
4064       int x = va_arg(ap,int);
4065       rc = x ? ALWAYS(x) : 0;
4066       break;
4067     }
4068 
4069     /*
4070     **   sqlite3_test_control(SQLITE_TESTCTRL_BYTEORDER);
4071     **
4072     ** The integer returned reveals the byte-order of the computer on which
4073     ** SQLite is running:
4074     **
4075     **       1     big-endian,    determined at run-time
4076     **      10     little-endian, determined at run-time
4077     **  432101     big-endian,    determined at compile-time
4078     **  123410     little-endian, determined at compile-time
4079     */
4080     case SQLITE_TESTCTRL_BYTEORDER: {
4081       rc = SQLITE_BYTEORDER*100 + SQLITE_LITTLEENDIAN*10 + SQLITE_BIGENDIAN;
4082       break;
4083     }
4084 
4085     /*  sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS, sqlite3 *db, int N)
4086     **
4087     ** Enable or disable various optimizations for testing purposes.  The
4088     ** argument N is a bitmask of optimizations to be disabled.  For normal
4089     ** operation N should be 0.  The idea is that a test program (like the
4090     ** SQL Logic Test or SLT test module) can run the same SQL multiple times
4091     ** with various optimizations disabled to verify that the same answer
4092     ** is obtained in every case.
4093     */
4094     case SQLITE_TESTCTRL_OPTIMIZATIONS: {
4095       sqlite3 *db = va_arg(ap, sqlite3*);
4096       db->dbOptFlags = va_arg(ap, u32);
4097       break;
4098     }
4099 
4100     /*   sqlite3_test_control(SQLITE_TESTCTRL_LOCALTIME_FAULT, int onoff);
4101     **
4102     ** If parameter onoff is non-zero, subsequent calls to localtime()
4103     ** and its variants fail. If onoff is zero, undo this setting.
4104     */
4105     case SQLITE_TESTCTRL_LOCALTIME_FAULT: {
4106       sqlite3GlobalConfig.bLocaltimeFault = va_arg(ap, int);
4107       break;
4108     }
4109 
4110     /*   sqlite3_test_control(SQLITE_TESTCTRL_INTERNAL_FUNCTIONS, sqlite3*);
4111     **
4112     ** Toggle the ability to use internal functions on or off for
4113     ** the database connection given in the argument.
4114     */
4115     case SQLITE_TESTCTRL_INTERNAL_FUNCTIONS: {
4116       sqlite3 *db = va_arg(ap, sqlite3*);
4117       db->mDbFlags ^= DBFLAG_InternalFunc;
4118       break;
4119     }
4120 
4121     /*   sqlite3_test_control(SQLITE_TESTCTRL_NEVER_CORRUPT, int);
4122     **
4123     ** Set or clear a flag that indicates that the database file is always well-
4124     ** formed and never corrupt.  This flag is clear by default, indicating that
4125     ** database files might have arbitrary corruption.  Setting the flag during
4126     ** testing causes certain assert() statements in the code to be activated
4127     ** that demonstrat invariants on well-formed database files.
4128     */
4129     case SQLITE_TESTCTRL_NEVER_CORRUPT: {
4130       sqlite3GlobalConfig.neverCorrupt = va_arg(ap, int);
4131       break;
4132     }
4133 
4134     /*   sqlite3_test_control(SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS, int);
4135     **
4136     ** Set or clear a flag that causes SQLite to verify that type, name,
4137     ** and tbl_name fields of the sqlite_schema table.  This is normally
4138     ** on, but it is sometimes useful to turn it off for testing.
4139     **
4140     ** 2020-07-22:  Disabling EXTRA_SCHEMA_CHECKS also disables the
4141     ** verification of rootpage numbers when parsing the schema.  This
4142     ** is useful to make it easier to reach strange internal error states
4143     ** during testing.  The EXTRA_SCHEMA_CHECKS setting is always enabled
4144     ** in production.
4145     */
4146     case SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS: {
4147       sqlite3GlobalConfig.bExtraSchemaChecks = va_arg(ap, int);
4148       break;
4149     }
4150 
4151     /* Set the threshold at which OP_Once counters reset back to zero.
4152     ** By default this is 0x7ffffffe (over 2 billion), but that value is
4153     ** too big to test in a reasonable amount of time, so this control is
4154     ** provided to set a small and easily reachable reset value.
4155     */
4156     case SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD: {
4157       sqlite3GlobalConfig.iOnceResetThreshold = va_arg(ap, int);
4158       break;
4159     }
4160 
4161     /*   sqlite3_test_control(SQLITE_TESTCTRL_VDBE_COVERAGE, xCallback, ptr);
4162     **
4163     ** Set the VDBE coverage callback function to xCallback with context
4164     ** pointer ptr.
4165     */
4166     case SQLITE_TESTCTRL_VDBE_COVERAGE: {
4167 #ifdef SQLITE_VDBE_COVERAGE
4168       typedef void (*branch_callback)(void*,unsigned int,
4169                                       unsigned char,unsigned char);
4170       sqlite3GlobalConfig.xVdbeBranch = va_arg(ap,branch_callback);
4171       sqlite3GlobalConfig.pVdbeBranchArg = va_arg(ap,void*);
4172 #endif
4173       break;
4174     }
4175 
4176     /*   sqlite3_test_control(SQLITE_TESTCTRL_SORTER_MMAP, db, nMax); */
4177     case SQLITE_TESTCTRL_SORTER_MMAP: {
4178       sqlite3 *db = va_arg(ap, sqlite3*);
4179       db->nMaxSorterMmap = va_arg(ap, int);
4180       break;
4181     }
4182 
4183     /*   sqlite3_test_control(SQLITE_TESTCTRL_ISINIT);
4184     **
4185     ** Return SQLITE_OK if SQLite has been initialized and SQLITE_ERROR if
4186     ** not.
4187     */
4188     case SQLITE_TESTCTRL_ISINIT: {
4189       if( sqlite3GlobalConfig.isInit==0 ) rc = SQLITE_ERROR;
4190       break;
4191     }
4192 
4193     /*  sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, db, dbName, onOff, tnum);
4194     **
4195     ** This test control is used to create imposter tables.  "db" is a pointer
4196     ** to the database connection.  dbName is the database name (ex: "main" or
4197     ** "temp") which will receive the imposter.  "onOff" turns imposter mode on
4198     ** or off.  "tnum" is the root page of the b-tree to which the imposter
4199     ** table should connect.
4200     **
4201     ** Enable imposter mode only when the schema has already been parsed.  Then
4202     ** run a single CREATE TABLE statement to construct the imposter table in
4203     ** the parsed schema.  Then turn imposter mode back off again.
4204     **
4205     ** If onOff==0 and tnum>0 then reset the schema for all databases, causing
4206     ** the schema to be reparsed the next time it is needed.  This has the
4207     ** effect of erasing all imposter tables.
4208     */
4209     case SQLITE_TESTCTRL_IMPOSTER: {
4210       sqlite3 *db = va_arg(ap, sqlite3*);
4211       sqlite3_mutex_enter(db->mutex);
4212       db->init.iDb = sqlite3FindDbName(db, va_arg(ap,const char*));
4213       db->init.busy = db->init.imposterTable = va_arg(ap,int);
4214       db->init.newTnum = va_arg(ap,int);
4215       if( db->init.busy==0 && db->init.newTnum>0 ){
4216         sqlite3ResetAllSchemasOfConnection(db);
4217       }
4218       sqlite3_mutex_leave(db->mutex);
4219       break;
4220     }
4221 
4222 #if defined(YYCOVERAGE)
4223     /*  sqlite3_test_control(SQLITE_TESTCTRL_PARSER_COVERAGE, FILE *out)
4224     **
4225     ** This test control (only available when SQLite is compiled with
4226     ** -DYYCOVERAGE) writes a report onto "out" that shows all
4227     ** state/lookahead combinations in the parser state machine
4228     ** which are never exercised.  If any state is missed, make the
4229     ** return code SQLITE_ERROR.
4230     */
4231     case SQLITE_TESTCTRL_PARSER_COVERAGE: {
4232       FILE *out = va_arg(ap, FILE*);
4233       if( sqlite3ParserCoverage(out) ) rc = SQLITE_ERROR;
4234       break;
4235     }
4236 #endif /* defined(YYCOVERAGE) */
4237 
4238     /*  sqlite3_test_control(SQLITE_TESTCTRL_RESULT_INTREAL, sqlite3_context*);
4239     **
4240     ** This test-control causes the most recent sqlite3_result_int64() value
4241     ** to be interpreted as a MEM_IntReal instead of as an MEM_Int.  Normally,
4242     ** MEM_IntReal values only arise during an INSERT operation of integer
4243     ** values into a REAL column, so they can be challenging to test.  This
4244     ** test-control enables us to write an intreal() SQL function that can
4245     ** inject an intreal() value at arbitrary places in an SQL statement,
4246     ** for testing purposes.
4247     */
4248     case SQLITE_TESTCTRL_RESULT_INTREAL: {
4249       sqlite3_context *pCtx = va_arg(ap, sqlite3_context*);
4250       sqlite3ResultIntReal(pCtx);
4251       break;
4252     }
4253 
4254     /*  sqlite3_test_control(SQLITE_TESTCTRL_SEEK_COUNT,
4255     **    sqlite3 *db,    // Database connection
4256     **    u64 *pnSeek     // Write seek count here
4257     **  );
4258     **
4259     ** This test-control queries the seek-counter on the "main" database
4260     ** file.  The seek-counter is written into *pnSeek and is then reset.
4261     ** The seek-count is only available if compiled with SQLITE_DEBUG.
4262     */
4263     case SQLITE_TESTCTRL_SEEK_COUNT: {
4264       sqlite3 *db = va_arg(ap, sqlite3*);
4265       u64 *pn = va_arg(ap, sqlite3_uint64*);
4266       *pn = sqlite3BtreeSeekCount(db->aDb->pBt);
4267       (void)db;  /* Silence harmless unused variable warning */
4268       break;
4269     }
4270 
4271     /*  sqlite3_test_control(SQLITE_TESTCTRL_TRACEFLAGS, op, ptr)
4272     **
4273     **  "ptr" is a pointer to a u32.
4274     **
4275     **   op==0       Store the current sqlite3SelectTrace in *ptr
4276     **   op==1       Set sqlite3SelectTrace to the value *ptr
4277     **   op==3       Store the current sqlite3WhereTrace in *ptr
4278     **   op==3       Set sqlite3WhereTrace to the value *ptr
4279     */
4280     case SQLITE_TESTCTRL_TRACEFLAGS: {
4281        int opTrace = va_arg(ap, int);
4282        u32 *ptr = va_arg(ap, u32*);
4283        switch( opTrace ){
4284          case 0:   *ptr = sqlite3SelectTrace;      break;
4285          case 1:   sqlite3SelectTrace = *ptr;      break;
4286          case 2:   *ptr = sqlite3WhereTrace;       break;
4287          case 3:   sqlite3WhereTrace = *ptr;       break;
4288        }
4289        break;
4290     }
4291 
4292 #if defined(SQLITE_DEBUG) && !defined(SQLITE_OMIT_WSD)
4293     /* sqlite3_test_control(SQLITE_TESTCTRL_TUNE, id, *piValue)
4294     **
4295     ** If "id" is an integer between 1 and SQLITE_NTUNE then set the value
4296     ** of the id-th tuning parameter to *piValue.  If "id" is between -1
4297     ** and -SQLITE_NTUNE, then write the current value of the (-id)-th
4298     ** tuning parameter into *piValue.
4299     **
4300     ** Tuning parameters are for use during transient development builds,
4301     ** to help find the best values for constants in the query planner.
4302     ** Access tuning parameters using the Tuning(ID) macro.  Set the
4303     ** parameters in the CLI using ".testctrl tune ID VALUE".
4304     **
4305     ** Transient use only.  Tuning parameters should not be used in
4306     ** checked-in code.
4307     */
4308     case SQLITE_TESTCTRL_TUNE: {
4309       int id = va_arg(ap, int);
4310       int *piValue = va_arg(ap, int*);
4311       if( id>0 && id<=SQLITE_NTUNE ){
4312         Tuning(id) = *piValue;
4313       }else if( id<0 && id>=-SQLITE_NTUNE ){
4314         *piValue = Tuning(-id);
4315       }else{
4316         rc = SQLITE_NOTFOUND;
4317       }
4318       break;
4319     }
4320 #endif
4321   }
4322   va_end(ap);
4323 #endif /* SQLITE_UNTESTABLE */
4324   return rc;
4325 }
4326 
4327 /*
4328 ** The Pager stores the Database filename, Journal filename, and WAL filename
4329 ** consecutively in memory, in that order.  The database filename is prefixed
4330 ** by four zero bytes.  Locate the start of the database filename by searching
4331 ** backwards for the first byte following four consecutive zero bytes.
4332 **
4333 ** This only works if the filename passed in was obtained from the Pager.
4334 */
4335 static const char *databaseName(const char *zName){
4336   while( zName[-1]!=0 || zName[-2]!=0 || zName[-3]!=0 || zName[-4]!=0 ){
4337     zName--;
4338   }
4339   return zName;
4340 }
4341 
4342 /*
4343 ** Append text z[] to the end of p[].  Return a pointer to the first
4344 ** character after then zero terminator on the new text in p[].
4345 */
4346 static char *appendText(char *p, const char *z){
4347   size_t n = strlen(z);
4348   memcpy(p, z, n+1);
4349   return p+n+1;
4350 }
4351 
4352 /*
4353 ** Allocate memory to hold names for a database, journal file, WAL file,
4354 ** and query parameters.  The pointer returned is valid for use by
4355 ** sqlite3_filename_database() and sqlite3_uri_parameter() and related
4356 ** functions.
4357 **
4358 ** Memory layout must be compatible with that generated by the pager
4359 ** and expected by sqlite3_uri_parameter() and databaseName().
4360 */
4361 char *sqlite3_create_filename(
4362   const char *zDatabase,
4363   const char *zJournal,
4364   const char *zWal,
4365   int nParam,
4366   const char **azParam
4367 ){
4368   sqlite3_int64 nByte;
4369   int i;
4370   char *pResult, *p;
4371   nByte = strlen(zDatabase) + strlen(zJournal) + strlen(zWal) + 10;
4372   for(i=0; i<nParam*2; i++){
4373     nByte += strlen(azParam[i])+1;
4374   }
4375   pResult = p = sqlite3_malloc64( nByte );
4376   if( p==0 ) return 0;
4377   memset(p, 0, 4);
4378   p += 4;
4379   p = appendText(p, zDatabase);
4380   for(i=0; i<nParam*2; i++){
4381     p = appendText(p, azParam[i]);
4382   }
4383   *(p++) = 0;
4384   p = appendText(p, zJournal);
4385   p = appendText(p, zWal);
4386   *(p++) = 0;
4387   *(p++) = 0;
4388   assert( (sqlite3_int64)(p - pResult)==nByte );
4389   return pResult + 4;
4390 }
4391 
4392 /*
4393 ** Free memory obtained from sqlite3_create_filename().  It is a severe
4394 ** error to call this routine with any parameter other than a pointer
4395 ** previously obtained from sqlite3_create_filename() or a NULL pointer.
4396 */
4397 void sqlite3_free_filename(char *p){
4398   if( p==0 ) return;
4399   p = (char*)databaseName(p);
4400   sqlite3_free(p - 4);
4401 }
4402 
4403 
4404 /*
4405 ** This is a utility routine, useful to VFS implementations, that checks
4406 ** to see if a database file was a URI that contained a specific query
4407 ** parameter, and if so obtains the value of the query parameter.
4408 **
4409 ** The zFilename argument is the filename pointer passed into the xOpen()
4410 ** method of a VFS implementation.  The zParam argument is the name of the
4411 ** query parameter we seek.  This routine returns the value of the zParam
4412 ** parameter if it exists.  If the parameter does not exist, this routine
4413 ** returns a NULL pointer.
4414 */
4415 const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam){
4416   if( zFilename==0 || zParam==0 ) return 0;
4417   zFilename = databaseName(zFilename);
4418   return uriParameter(zFilename, zParam);
4419 }
4420 
4421 /*
4422 ** Return a pointer to the name of Nth query parameter of the filename.
4423 */
4424 const char *sqlite3_uri_key(const char *zFilename, int N){
4425   if( zFilename==0 || N<0 ) return 0;
4426   zFilename = databaseName(zFilename);
4427   zFilename += sqlite3Strlen30(zFilename) + 1;
4428   while( zFilename[0] && (N--)>0 ){
4429     zFilename += sqlite3Strlen30(zFilename) + 1;
4430     zFilename += sqlite3Strlen30(zFilename) + 1;
4431   }
4432   return zFilename[0] ? zFilename : 0;
4433 }
4434 
4435 /*
4436 ** Return a boolean value for a query parameter.
4437 */
4438 int sqlite3_uri_boolean(const char *zFilename, const char *zParam, int bDflt){
4439   const char *z = sqlite3_uri_parameter(zFilename, zParam);
4440   bDflt = bDflt!=0;
4441   return z ? sqlite3GetBoolean(z, bDflt) : bDflt;
4442 }
4443 
4444 /*
4445 ** Return a 64-bit integer value for a query parameter.
4446 */
4447 sqlite3_int64 sqlite3_uri_int64(
4448   const char *zFilename,    /* Filename as passed to xOpen */
4449   const char *zParam,       /* URI parameter sought */
4450   sqlite3_int64 bDflt       /* return if parameter is missing */
4451 ){
4452   const char *z = sqlite3_uri_parameter(zFilename, zParam);
4453   sqlite3_int64 v;
4454   if( z && sqlite3DecOrHexToI64(z, &v)==0 ){
4455     bDflt = v;
4456   }
4457   return bDflt;
4458 }
4459 
4460 /*
4461 ** Translate a filename that was handed to a VFS routine into the corresponding
4462 ** database, journal, or WAL file.
4463 **
4464 ** It is an error to pass this routine a filename string that was not
4465 ** passed into the VFS from the SQLite core.  Doing so is similar to
4466 ** passing free() a pointer that was not obtained from malloc() - it is
4467 ** an error that we cannot easily detect but that will likely cause memory
4468 ** corruption.
4469 */
4470 const char *sqlite3_filename_database(const char *zFilename){
4471   return databaseName(zFilename);
4472 }
4473 const char *sqlite3_filename_journal(const char *zFilename){
4474   zFilename = databaseName(zFilename);
4475   zFilename += sqlite3Strlen30(zFilename) + 1;
4476   while( zFilename[0] ){
4477     zFilename += sqlite3Strlen30(zFilename) + 1;
4478     zFilename += sqlite3Strlen30(zFilename) + 1;
4479   }
4480   return zFilename + 1;
4481 }
4482 const char *sqlite3_filename_wal(const char *zFilename){
4483 #ifdef SQLITE_OMIT_WAL
4484   return 0;
4485 #else
4486   zFilename = sqlite3_filename_journal(zFilename);
4487   zFilename += sqlite3Strlen30(zFilename) + 1;
4488   return zFilename;
4489 #endif
4490 }
4491 
4492 /*
4493 ** Return the Btree pointer identified by zDbName.  Return NULL if not found.
4494 */
4495 Btree *sqlite3DbNameToBtree(sqlite3 *db, const char *zDbName){
4496   int iDb = zDbName ? sqlite3FindDbName(db, zDbName) : 0;
4497   return iDb<0 ? 0 : db->aDb[iDb].pBt;
4498 }
4499 
4500 /*
4501 ** Return the filename of the database associated with a database
4502 ** connection.
4503 */
4504 const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName){
4505   Btree *pBt;
4506 #ifdef SQLITE_ENABLE_API_ARMOR
4507   if( !sqlite3SafetyCheckOk(db) ){
4508     (void)SQLITE_MISUSE_BKPT;
4509     return 0;
4510   }
4511 #endif
4512   pBt = sqlite3DbNameToBtree(db, zDbName);
4513   return pBt ? sqlite3BtreeGetFilename(pBt) : 0;
4514 }
4515 
4516 /*
4517 ** Return 1 if database is read-only or 0 if read/write.  Return -1 if
4518 ** no such database exists.
4519 */
4520 int sqlite3_db_readonly(sqlite3 *db, const char *zDbName){
4521   Btree *pBt;
4522 #ifdef SQLITE_ENABLE_API_ARMOR
4523   if( !sqlite3SafetyCheckOk(db) ){
4524     (void)SQLITE_MISUSE_BKPT;
4525     return -1;
4526   }
4527 #endif
4528   pBt = sqlite3DbNameToBtree(db, zDbName);
4529   return pBt ? sqlite3BtreeIsReadonly(pBt) : -1;
4530 }
4531 
4532 #ifdef SQLITE_ENABLE_SNAPSHOT
4533 /*
4534 ** Obtain a snapshot handle for the snapshot of database zDb currently
4535 ** being read by handle db.
4536 */
4537 int sqlite3_snapshot_get(
4538   sqlite3 *db,
4539   const char *zDb,
4540   sqlite3_snapshot **ppSnapshot
4541 ){
4542   int rc = SQLITE_ERROR;
4543 #ifndef SQLITE_OMIT_WAL
4544 
4545 #ifdef SQLITE_ENABLE_API_ARMOR
4546   if( !sqlite3SafetyCheckOk(db) ){
4547     return SQLITE_MISUSE_BKPT;
4548   }
4549 #endif
4550   sqlite3_mutex_enter(db->mutex);
4551 
4552   if( db->autoCommit==0 ){
4553     int iDb = sqlite3FindDbName(db, zDb);
4554     if( iDb==0 || iDb>1 ){
4555       Btree *pBt = db->aDb[iDb].pBt;
4556       if( SQLITE_TXN_WRITE!=sqlite3BtreeTxnState(pBt) ){
4557         rc = sqlite3BtreeBeginTrans(pBt, 0, 0);
4558         if( rc==SQLITE_OK ){
4559           rc = sqlite3PagerSnapshotGet(sqlite3BtreePager(pBt), ppSnapshot);
4560         }
4561       }
4562     }
4563   }
4564 
4565   sqlite3_mutex_leave(db->mutex);
4566 #endif   /* SQLITE_OMIT_WAL */
4567   return rc;
4568 }
4569 
4570 /*
4571 ** Open a read-transaction on the snapshot idendified by pSnapshot.
4572 */
4573 int sqlite3_snapshot_open(
4574   sqlite3 *db,
4575   const char *zDb,
4576   sqlite3_snapshot *pSnapshot
4577 ){
4578   int rc = SQLITE_ERROR;
4579 #ifndef SQLITE_OMIT_WAL
4580 
4581 #ifdef SQLITE_ENABLE_API_ARMOR
4582   if( !sqlite3SafetyCheckOk(db) ){
4583     return SQLITE_MISUSE_BKPT;
4584   }
4585 #endif
4586   sqlite3_mutex_enter(db->mutex);
4587   if( db->autoCommit==0 ){
4588     int iDb;
4589     iDb = sqlite3FindDbName(db, zDb);
4590     if( iDb==0 || iDb>1 ){
4591       Btree *pBt = db->aDb[iDb].pBt;
4592       if( sqlite3BtreeTxnState(pBt)!=SQLITE_TXN_WRITE ){
4593         Pager *pPager = sqlite3BtreePager(pBt);
4594         int bUnlock = 0;
4595         if( sqlite3BtreeTxnState(pBt)!=SQLITE_TXN_NONE ){
4596           if( db->nVdbeActive==0 ){
4597             rc = sqlite3PagerSnapshotCheck(pPager, pSnapshot);
4598             if( rc==SQLITE_OK ){
4599               bUnlock = 1;
4600               rc = sqlite3BtreeCommit(pBt);
4601             }
4602           }
4603         }else{
4604           rc = SQLITE_OK;
4605         }
4606         if( rc==SQLITE_OK ){
4607           rc = sqlite3PagerSnapshotOpen(pPager, pSnapshot);
4608         }
4609         if( rc==SQLITE_OK ){
4610           rc = sqlite3BtreeBeginTrans(pBt, 0, 0);
4611           sqlite3PagerSnapshotOpen(pPager, 0);
4612         }
4613         if( bUnlock ){
4614           sqlite3PagerSnapshotUnlock(pPager);
4615         }
4616       }
4617     }
4618   }
4619 
4620   sqlite3_mutex_leave(db->mutex);
4621 #endif   /* SQLITE_OMIT_WAL */
4622   return rc;
4623 }
4624 
4625 /*
4626 ** Recover as many snapshots as possible from the wal file associated with
4627 ** schema zDb of database db.
4628 */
4629 int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb){
4630   int rc = SQLITE_ERROR;
4631   int iDb;
4632 #ifndef SQLITE_OMIT_WAL
4633 
4634 #ifdef SQLITE_ENABLE_API_ARMOR
4635   if( !sqlite3SafetyCheckOk(db) ){
4636     return SQLITE_MISUSE_BKPT;
4637   }
4638 #endif
4639 
4640   sqlite3_mutex_enter(db->mutex);
4641   iDb = sqlite3FindDbName(db, zDb);
4642   if( iDb==0 || iDb>1 ){
4643     Btree *pBt = db->aDb[iDb].pBt;
4644     if( SQLITE_TXN_NONE==sqlite3BtreeTxnState(pBt) ){
4645       rc = sqlite3BtreeBeginTrans(pBt, 0, 0);
4646       if( rc==SQLITE_OK ){
4647         rc = sqlite3PagerSnapshotRecover(sqlite3BtreePager(pBt));
4648         sqlite3BtreeCommit(pBt);
4649       }
4650     }
4651   }
4652   sqlite3_mutex_leave(db->mutex);
4653 #endif   /* SQLITE_OMIT_WAL */
4654   return rc;
4655 }
4656 
4657 /*
4658 ** Free a snapshot handle obtained from sqlite3_snapshot_get().
4659 */
4660 void sqlite3_snapshot_free(sqlite3_snapshot *pSnapshot){
4661   sqlite3_free(pSnapshot);
4662 }
4663 #endif /* SQLITE_ENABLE_SNAPSHOT */
4664 
4665 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
4666 /*
4667 ** Given the name of a compile-time option, return true if that option
4668 ** was used and false if not.
4669 **
4670 ** The name can optionally begin with "SQLITE_" but the "SQLITE_" prefix
4671 ** is not required for a match.
4672 */
4673 int sqlite3_compileoption_used(const char *zOptName){
4674   int i, n;
4675   int nOpt;
4676   const char **azCompileOpt;
4677 
4678 #if SQLITE_ENABLE_API_ARMOR
4679   if( zOptName==0 ){
4680     (void)SQLITE_MISUSE_BKPT;
4681     return 0;
4682   }
4683 #endif
4684 
4685   azCompileOpt = sqlite3CompileOptions(&nOpt);
4686 
4687   if( sqlite3StrNICmp(zOptName, "SQLITE_", 7)==0 ) zOptName += 7;
4688   n = sqlite3Strlen30(zOptName);
4689 
4690   /* Since nOpt is normally in single digits, a linear search is
4691   ** adequate. No need for a binary search. */
4692   for(i=0; i<nOpt; i++){
4693     if( sqlite3StrNICmp(zOptName, azCompileOpt[i], n)==0
4694      && sqlite3IsIdChar((unsigned char)azCompileOpt[i][n])==0
4695     ){
4696       return 1;
4697     }
4698   }
4699   return 0;
4700 }
4701 
4702 /*
4703 ** Return the N-th compile-time option string.  If N is out of range,
4704 ** return a NULL pointer.
4705 */
4706 const char *sqlite3_compileoption_get(int N){
4707   int nOpt;
4708   const char **azCompileOpt;
4709   azCompileOpt = sqlite3CompileOptions(&nOpt);
4710   if( N>=0 && N<nOpt ){
4711     return azCompileOpt[N];
4712   }
4713   return 0;
4714 }
4715 #endif /* SQLITE_OMIT_COMPILEOPTION_DIAGS */
4716