xref: /sqlite-3.40.0/src/main.c (revision 7d4c94bc)
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->eOpenState = SQLITE_STATE_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->eOpenState!=SQLITE_STATE_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->eOpenState = SQLITE_STATE_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->eOpenState = SQLITE_STATE_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->eOpenState!=SQLITE_STATE_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 extraFlags;
1823 
1824   assert( sqlite3_mutex_held(db->mutex) );
1825   assert( xValue==0 || xSFunc==0 );
1826   if( zFunctionName==0                /* Must have a valid name */
1827    || (xSFunc!=0 && xFinal!=0)        /* Not both xSFunc and xFinal */
1828    || ((xFinal==0)!=(xStep==0))       /* Both or neither of xFinal and xStep */
1829    || ((xValue==0)!=(xInverse==0))    /* Both or neither of xValue, xInverse */
1830    || (nArg<-1 || nArg>SQLITE_MAX_FUNCTION_ARG)
1831    || (255<sqlite3Strlen30(zFunctionName))
1832   ){
1833     return SQLITE_MISUSE_BKPT;
1834   }
1835 
1836   assert( SQLITE_FUNC_CONSTANT==SQLITE_DETERMINISTIC );
1837   assert( SQLITE_FUNC_DIRECT==SQLITE_DIRECTONLY );
1838   extraFlags = enc &  (SQLITE_DETERMINISTIC|SQLITE_DIRECTONLY|
1839                        SQLITE_SUBTYPE|SQLITE_INNOCUOUS);
1840   enc &= (SQLITE_FUNC_ENCMASK|SQLITE_ANY);
1841 
1842   /* The SQLITE_INNOCUOUS flag is the same bit as SQLITE_FUNC_UNSAFE.  But
1843   ** the meaning is inverted.  So flip the bit. */
1844   assert( SQLITE_FUNC_UNSAFE==SQLITE_INNOCUOUS );
1845   extraFlags ^= SQLITE_FUNC_UNSAFE;
1846 
1847 
1848 #ifndef SQLITE_OMIT_UTF16
1849   /* If SQLITE_UTF16 is specified as the encoding type, transform this
1850   ** to one of SQLITE_UTF16LE or SQLITE_UTF16BE using the
1851   ** SQLITE_UTF16NATIVE macro. SQLITE_UTF16 is not used internally.
1852   **
1853   ** If SQLITE_ANY is specified, add three versions of the function
1854   ** to the hash table.
1855   */
1856   switch( enc ){
1857     case SQLITE_UTF16:
1858       enc = SQLITE_UTF16NATIVE;
1859       break;
1860     case SQLITE_ANY: {
1861       int rc;
1862       rc = sqlite3CreateFunc(db, zFunctionName, nArg,
1863            (SQLITE_UTF8|extraFlags)^SQLITE_FUNC_UNSAFE,
1864            pUserData, xSFunc, xStep, xFinal, xValue, xInverse, pDestructor);
1865       if( rc==SQLITE_OK ){
1866         rc = sqlite3CreateFunc(db, zFunctionName, nArg,
1867              (SQLITE_UTF16LE|extraFlags)^SQLITE_FUNC_UNSAFE,
1868              pUserData, xSFunc, xStep, xFinal, xValue, xInverse, pDestructor);
1869       }
1870       if( rc!=SQLITE_OK ){
1871         return rc;
1872       }
1873       enc = SQLITE_UTF16BE;
1874       break;
1875     }
1876     case SQLITE_UTF8:
1877     case SQLITE_UTF16LE:
1878     case SQLITE_UTF16BE:
1879       break;
1880     default:
1881       enc = SQLITE_UTF8;
1882       break;
1883   }
1884 #else
1885   enc = SQLITE_UTF8;
1886 #endif
1887 
1888   /* Check if an existing function is being overridden or deleted. If so,
1889   ** and there are active VMs, then return SQLITE_BUSY. If a function
1890   ** is being overridden/deleted but there are no active VMs, allow the
1891   ** operation to continue but invalidate all precompiled statements.
1892   */
1893   p = sqlite3FindFunction(db, zFunctionName, nArg, (u8)enc, 0);
1894   if( p && (p->funcFlags & SQLITE_FUNC_ENCMASK)==(u32)enc && p->nArg==nArg ){
1895     if( db->nVdbeActive ){
1896       sqlite3ErrorWithMsg(db, SQLITE_BUSY,
1897         "unable to delete/modify user-function due to active statements");
1898       assert( !db->mallocFailed );
1899       return SQLITE_BUSY;
1900     }else{
1901       sqlite3ExpirePreparedStatements(db, 0);
1902     }
1903   }else if( xSFunc==0 && xFinal==0 ){
1904     /* Trying to delete a function that does not exist.  This is a no-op.
1905     ** https://sqlite.org/forum/forumpost/726219164b */
1906     return SQLITE_OK;
1907   }
1908 
1909   p = sqlite3FindFunction(db, zFunctionName, nArg, (u8)enc, 1);
1910   assert(p || db->mallocFailed);
1911   if( !p ){
1912     return SQLITE_NOMEM_BKPT;
1913   }
1914 
1915   /* If an older version of the function with a configured destructor is
1916   ** being replaced invoke the destructor function here. */
1917   functionDestroy(db, p);
1918 
1919   if( pDestructor ){
1920     pDestructor->nRef++;
1921   }
1922   p->u.pDestructor = pDestructor;
1923   p->funcFlags = (p->funcFlags & SQLITE_FUNC_ENCMASK) | extraFlags;
1924   testcase( p->funcFlags & SQLITE_DETERMINISTIC );
1925   testcase( p->funcFlags & SQLITE_DIRECTONLY );
1926   p->xSFunc = xSFunc ? xSFunc : xStep;
1927   p->xFinalize = xFinal;
1928   p->xValue = xValue;
1929   p->xInverse = xInverse;
1930   p->pUserData = pUserData;
1931   p->nArg = (u16)nArg;
1932   return SQLITE_OK;
1933 }
1934 
1935 /*
1936 ** Worker function used by utf-8 APIs that create new functions:
1937 **
1938 **    sqlite3_create_function()
1939 **    sqlite3_create_function_v2()
1940 **    sqlite3_create_window_function()
1941 */
1942 static int createFunctionApi(
1943   sqlite3 *db,
1944   const char *zFunc,
1945   int nArg,
1946   int enc,
1947   void *p,
1948   void (*xSFunc)(sqlite3_context*,int,sqlite3_value**),
1949   void (*xStep)(sqlite3_context*,int,sqlite3_value**),
1950   void (*xFinal)(sqlite3_context*),
1951   void (*xValue)(sqlite3_context*),
1952   void (*xInverse)(sqlite3_context*,int,sqlite3_value**),
1953   void(*xDestroy)(void*)
1954 ){
1955   int rc = SQLITE_ERROR;
1956   FuncDestructor *pArg = 0;
1957 
1958 #ifdef SQLITE_ENABLE_API_ARMOR
1959   if( !sqlite3SafetyCheckOk(db) ){
1960     return SQLITE_MISUSE_BKPT;
1961   }
1962 #endif
1963   sqlite3_mutex_enter(db->mutex);
1964   if( xDestroy ){
1965     pArg = (FuncDestructor *)sqlite3Malloc(sizeof(FuncDestructor));
1966     if( !pArg ){
1967       sqlite3OomFault(db);
1968       xDestroy(p);
1969       goto out;
1970     }
1971     pArg->nRef = 0;
1972     pArg->xDestroy = xDestroy;
1973     pArg->pUserData = p;
1974   }
1975   rc = sqlite3CreateFunc(db, zFunc, nArg, enc, p,
1976       xSFunc, xStep, xFinal, xValue, xInverse, pArg
1977   );
1978   if( pArg && pArg->nRef==0 ){
1979     assert( rc!=SQLITE_OK || (xStep==0 && xFinal==0) );
1980     xDestroy(p);
1981     sqlite3_free(pArg);
1982   }
1983 
1984  out:
1985   rc = sqlite3ApiExit(db, rc);
1986   sqlite3_mutex_leave(db->mutex);
1987   return rc;
1988 }
1989 
1990 /*
1991 ** Create new user functions.
1992 */
1993 int sqlite3_create_function(
1994   sqlite3 *db,
1995   const char *zFunc,
1996   int nArg,
1997   int enc,
1998   void *p,
1999   void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
2000   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
2001   void (*xFinal)(sqlite3_context*)
2002 ){
2003   return createFunctionApi(db, zFunc, nArg, enc, p, xSFunc, xStep,
2004                                     xFinal, 0, 0, 0);
2005 }
2006 int sqlite3_create_function_v2(
2007   sqlite3 *db,
2008   const char *zFunc,
2009   int nArg,
2010   int enc,
2011   void *p,
2012   void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
2013   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
2014   void (*xFinal)(sqlite3_context*),
2015   void (*xDestroy)(void *)
2016 ){
2017   return createFunctionApi(db, zFunc, nArg, enc, p, xSFunc, xStep,
2018                                     xFinal, 0, 0, xDestroy);
2019 }
2020 int sqlite3_create_window_function(
2021   sqlite3 *db,
2022   const char *zFunc,
2023   int nArg,
2024   int enc,
2025   void *p,
2026   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
2027   void (*xFinal)(sqlite3_context*),
2028   void (*xValue)(sqlite3_context*),
2029   void (*xInverse)(sqlite3_context*,int,sqlite3_value **),
2030   void (*xDestroy)(void *)
2031 ){
2032   return createFunctionApi(db, zFunc, nArg, enc, p, 0, xStep,
2033                                     xFinal, xValue, xInverse, xDestroy);
2034 }
2035 
2036 #ifndef SQLITE_OMIT_UTF16
2037 int sqlite3_create_function16(
2038   sqlite3 *db,
2039   const void *zFunctionName,
2040   int nArg,
2041   int eTextRep,
2042   void *p,
2043   void (*xSFunc)(sqlite3_context*,int,sqlite3_value**),
2044   void (*xStep)(sqlite3_context*,int,sqlite3_value**),
2045   void (*xFinal)(sqlite3_context*)
2046 ){
2047   int rc;
2048   char *zFunc8;
2049 
2050 #ifdef SQLITE_ENABLE_API_ARMOR
2051   if( !sqlite3SafetyCheckOk(db) || zFunctionName==0 ) return SQLITE_MISUSE_BKPT;
2052 #endif
2053   sqlite3_mutex_enter(db->mutex);
2054   assert( !db->mallocFailed );
2055   zFunc8 = sqlite3Utf16to8(db, zFunctionName, -1, SQLITE_UTF16NATIVE);
2056   rc = sqlite3CreateFunc(db, zFunc8, nArg, eTextRep, p, xSFunc,xStep,xFinal,0,0,0);
2057   sqlite3DbFree(db, zFunc8);
2058   rc = sqlite3ApiExit(db, rc);
2059   sqlite3_mutex_leave(db->mutex);
2060   return rc;
2061 }
2062 #endif
2063 
2064 
2065 /*
2066 ** The following is the implementation of an SQL function that always
2067 ** fails with an error message stating that the function is used in the
2068 ** wrong context.  The sqlite3_overload_function() API might construct
2069 ** SQL function that use this routine so that the functions will exist
2070 ** for name resolution but are actually overloaded by the xFindFunction
2071 ** method of virtual tables.
2072 */
2073 static void sqlite3InvalidFunction(
2074   sqlite3_context *context,  /* The function calling context */
2075   int NotUsed,               /* Number of arguments to the function */
2076   sqlite3_value **NotUsed2   /* Value of each argument */
2077 ){
2078   const char *zName = (const char*)sqlite3_user_data(context);
2079   char *zErr;
2080   UNUSED_PARAMETER2(NotUsed, NotUsed2);
2081   zErr = sqlite3_mprintf(
2082       "unable to use function %s in the requested context", zName);
2083   sqlite3_result_error(context, zErr, -1);
2084   sqlite3_free(zErr);
2085 }
2086 
2087 /*
2088 ** Declare that a function has been overloaded by a virtual table.
2089 **
2090 ** If the function already exists as a regular global function, then
2091 ** this routine is a no-op.  If the function does not exist, then create
2092 ** a new one that always throws a run-time error.
2093 **
2094 ** When virtual tables intend to provide an overloaded function, they
2095 ** should call this routine to make sure the global function exists.
2096 ** A global function must exist in order for name resolution to work
2097 ** properly.
2098 */
2099 int sqlite3_overload_function(
2100   sqlite3 *db,
2101   const char *zName,
2102   int nArg
2103 ){
2104   int rc;
2105   char *zCopy;
2106 
2107 #ifdef SQLITE_ENABLE_API_ARMOR
2108   if( !sqlite3SafetyCheckOk(db) || zName==0 || nArg<-2 ){
2109     return SQLITE_MISUSE_BKPT;
2110   }
2111 #endif
2112   sqlite3_mutex_enter(db->mutex);
2113   rc = sqlite3FindFunction(db, zName, nArg, SQLITE_UTF8, 0)!=0;
2114   sqlite3_mutex_leave(db->mutex);
2115   if( rc ) return SQLITE_OK;
2116   zCopy = sqlite3_mprintf(zName);
2117   if( zCopy==0 ) return SQLITE_NOMEM;
2118   return sqlite3_create_function_v2(db, zName, nArg, SQLITE_UTF8,
2119                            zCopy, sqlite3InvalidFunction, 0, 0, sqlite3_free);
2120 }
2121 
2122 #ifndef SQLITE_OMIT_TRACE
2123 /*
2124 ** Register a trace function.  The pArg from the previously registered trace
2125 ** is returned.
2126 **
2127 ** A NULL trace function means that no tracing is executes.  A non-NULL
2128 ** trace is a pointer to a function that is invoked at the start of each
2129 ** SQL statement.
2130 */
2131 #ifndef SQLITE_OMIT_DEPRECATED
2132 void *sqlite3_trace(sqlite3 *db, void(*xTrace)(void*,const char*), void *pArg){
2133   void *pOld;
2134 
2135 #ifdef SQLITE_ENABLE_API_ARMOR
2136   if( !sqlite3SafetyCheckOk(db) ){
2137     (void)SQLITE_MISUSE_BKPT;
2138     return 0;
2139   }
2140 #endif
2141   sqlite3_mutex_enter(db->mutex);
2142   pOld = db->pTraceArg;
2143   db->mTrace = xTrace ? SQLITE_TRACE_LEGACY : 0;
2144   db->trace.xLegacy = xTrace;
2145   db->pTraceArg = pArg;
2146   sqlite3_mutex_leave(db->mutex);
2147   return pOld;
2148 }
2149 #endif /* SQLITE_OMIT_DEPRECATED */
2150 
2151 /* Register a trace callback using the version-2 interface.
2152 */
2153 int sqlite3_trace_v2(
2154   sqlite3 *db,                               /* Trace this connection */
2155   unsigned mTrace,                           /* Mask of events to be traced */
2156   int(*xTrace)(unsigned,void*,void*,void*),  /* Callback to invoke */
2157   void *pArg                                 /* Context */
2158 ){
2159 #ifdef SQLITE_ENABLE_API_ARMOR
2160   if( !sqlite3SafetyCheckOk(db) ){
2161     return SQLITE_MISUSE_BKPT;
2162   }
2163 #endif
2164   sqlite3_mutex_enter(db->mutex);
2165   if( mTrace==0 ) xTrace = 0;
2166   if( xTrace==0 ) mTrace = 0;
2167   db->mTrace = mTrace;
2168   db->trace.xV2 = xTrace;
2169   db->pTraceArg = pArg;
2170   sqlite3_mutex_leave(db->mutex);
2171   return SQLITE_OK;
2172 }
2173 
2174 #ifndef SQLITE_OMIT_DEPRECATED
2175 /*
2176 ** Register a profile function.  The pArg from the previously registered
2177 ** profile function is returned.
2178 **
2179 ** A NULL profile function means that no profiling is executes.  A non-NULL
2180 ** profile is a pointer to a function that is invoked at the conclusion of
2181 ** each SQL statement that is run.
2182 */
2183 void *sqlite3_profile(
2184   sqlite3 *db,
2185   void (*xProfile)(void*,const char*,sqlite_uint64),
2186   void *pArg
2187 ){
2188   void *pOld;
2189 
2190 #ifdef SQLITE_ENABLE_API_ARMOR
2191   if( !sqlite3SafetyCheckOk(db) ){
2192     (void)SQLITE_MISUSE_BKPT;
2193     return 0;
2194   }
2195 #endif
2196   sqlite3_mutex_enter(db->mutex);
2197   pOld = db->pProfileArg;
2198   db->xProfile = xProfile;
2199   db->pProfileArg = pArg;
2200   db->mTrace &= SQLITE_TRACE_NONLEGACY_MASK;
2201   if( db->xProfile ) db->mTrace |= SQLITE_TRACE_XPROFILE;
2202   sqlite3_mutex_leave(db->mutex);
2203   return pOld;
2204 }
2205 #endif /* SQLITE_OMIT_DEPRECATED */
2206 #endif /* SQLITE_OMIT_TRACE */
2207 
2208 /*
2209 ** Register a function to be invoked when a transaction commits.
2210 ** If the invoked function returns non-zero, then the commit becomes a
2211 ** rollback.
2212 */
2213 void *sqlite3_commit_hook(
2214   sqlite3 *db,              /* Attach the hook to this database */
2215   int (*xCallback)(void*),  /* Function to invoke on each commit */
2216   void *pArg                /* Argument to the function */
2217 ){
2218   void *pOld;
2219 
2220 #ifdef SQLITE_ENABLE_API_ARMOR
2221   if( !sqlite3SafetyCheckOk(db) ){
2222     (void)SQLITE_MISUSE_BKPT;
2223     return 0;
2224   }
2225 #endif
2226   sqlite3_mutex_enter(db->mutex);
2227   pOld = db->pCommitArg;
2228   db->xCommitCallback = xCallback;
2229   db->pCommitArg = pArg;
2230   sqlite3_mutex_leave(db->mutex);
2231   return pOld;
2232 }
2233 
2234 /*
2235 ** Register a callback to be invoked each time a row is updated,
2236 ** inserted or deleted using this database connection.
2237 */
2238 void *sqlite3_update_hook(
2239   sqlite3 *db,              /* Attach the hook to this database */
2240   void (*xCallback)(void*,int,char const *,char const *,sqlite_int64),
2241   void *pArg                /* Argument to the function */
2242 ){
2243   void *pRet;
2244 
2245 #ifdef SQLITE_ENABLE_API_ARMOR
2246   if( !sqlite3SafetyCheckOk(db) ){
2247     (void)SQLITE_MISUSE_BKPT;
2248     return 0;
2249   }
2250 #endif
2251   sqlite3_mutex_enter(db->mutex);
2252   pRet = db->pUpdateArg;
2253   db->xUpdateCallback = xCallback;
2254   db->pUpdateArg = pArg;
2255   sqlite3_mutex_leave(db->mutex);
2256   return pRet;
2257 }
2258 
2259 /*
2260 ** Register a callback to be invoked each time a transaction is rolled
2261 ** back by this database connection.
2262 */
2263 void *sqlite3_rollback_hook(
2264   sqlite3 *db,              /* Attach the hook to this database */
2265   void (*xCallback)(void*), /* Callback function */
2266   void *pArg                /* Argument to the function */
2267 ){
2268   void *pRet;
2269 
2270 #ifdef SQLITE_ENABLE_API_ARMOR
2271   if( !sqlite3SafetyCheckOk(db) ){
2272     (void)SQLITE_MISUSE_BKPT;
2273     return 0;
2274   }
2275 #endif
2276   sqlite3_mutex_enter(db->mutex);
2277   pRet = db->pRollbackArg;
2278   db->xRollbackCallback = xCallback;
2279   db->pRollbackArg = pArg;
2280   sqlite3_mutex_leave(db->mutex);
2281   return pRet;
2282 }
2283 
2284 #ifdef SQLITE_ENABLE_PREUPDATE_HOOK
2285 /*
2286 ** Register a callback to be invoked each time a row is updated,
2287 ** inserted or deleted using this database connection.
2288 */
2289 void *sqlite3_preupdate_hook(
2290   sqlite3 *db,              /* Attach the hook to this database */
2291   void(*xCallback)(         /* Callback function */
2292     void*,sqlite3*,int,char const*,char const*,sqlite3_int64,sqlite3_int64),
2293   void *pArg                /* First callback argument */
2294 ){
2295   void *pRet;
2296   sqlite3_mutex_enter(db->mutex);
2297   pRet = db->pPreUpdateArg;
2298   db->xPreUpdateCallback = xCallback;
2299   db->pPreUpdateArg = pArg;
2300   sqlite3_mutex_leave(db->mutex);
2301   return pRet;
2302 }
2303 #endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
2304 
2305 #ifndef SQLITE_OMIT_WAL
2306 /*
2307 ** The sqlite3_wal_hook() callback registered by sqlite3_wal_autocheckpoint().
2308 ** Invoke sqlite3_wal_checkpoint if the number of frames in the log file
2309 ** is greater than sqlite3.pWalArg cast to an integer (the value configured by
2310 ** wal_autocheckpoint()).
2311 */
2312 int sqlite3WalDefaultHook(
2313   void *pClientData,     /* Argument */
2314   sqlite3 *db,           /* Connection */
2315   const char *zDb,       /* Database */
2316   int nFrame             /* Size of WAL */
2317 ){
2318   if( nFrame>=SQLITE_PTR_TO_INT(pClientData) ){
2319     sqlite3BeginBenignMalloc();
2320     sqlite3_wal_checkpoint(db, zDb);
2321     sqlite3EndBenignMalloc();
2322   }
2323   return SQLITE_OK;
2324 }
2325 #endif /* SQLITE_OMIT_WAL */
2326 
2327 /*
2328 ** Configure an sqlite3_wal_hook() callback to automatically checkpoint
2329 ** a database after committing a transaction if there are nFrame or
2330 ** more frames in the log file. Passing zero or a negative value as the
2331 ** nFrame parameter disables automatic checkpoints entirely.
2332 **
2333 ** The callback registered by this function replaces any existing callback
2334 ** registered using sqlite3_wal_hook(). Likewise, registering a callback
2335 ** using sqlite3_wal_hook() disables the automatic checkpoint mechanism
2336 ** configured by this function.
2337 */
2338 int sqlite3_wal_autocheckpoint(sqlite3 *db, int nFrame){
2339 #ifdef SQLITE_OMIT_WAL
2340   UNUSED_PARAMETER(db);
2341   UNUSED_PARAMETER(nFrame);
2342 #else
2343 #ifdef SQLITE_ENABLE_API_ARMOR
2344   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
2345 #endif
2346   if( nFrame>0 ){
2347     sqlite3_wal_hook(db, sqlite3WalDefaultHook, SQLITE_INT_TO_PTR(nFrame));
2348   }else{
2349     sqlite3_wal_hook(db, 0, 0);
2350   }
2351 #endif
2352   return SQLITE_OK;
2353 }
2354 
2355 /*
2356 ** Register a callback to be invoked each time a transaction is written
2357 ** into the write-ahead-log by this database connection.
2358 */
2359 void *sqlite3_wal_hook(
2360   sqlite3 *db,                    /* Attach the hook to this db handle */
2361   int(*xCallback)(void *, sqlite3*, const char*, int),
2362   void *pArg                      /* First argument passed to xCallback() */
2363 ){
2364 #ifndef SQLITE_OMIT_WAL
2365   void *pRet;
2366 #ifdef SQLITE_ENABLE_API_ARMOR
2367   if( !sqlite3SafetyCheckOk(db) ){
2368     (void)SQLITE_MISUSE_BKPT;
2369     return 0;
2370   }
2371 #endif
2372   sqlite3_mutex_enter(db->mutex);
2373   pRet = db->pWalArg;
2374   db->xWalCallback = xCallback;
2375   db->pWalArg = pArg;
2376   sqlite3_mutex_leave(db->mutex);
2377   return pRet;
2378 #else
2379   return 0;
2380 #endif
2381 }
2382 
2383 /*
2384 ** Checkpoint database zDb.
2385 */
2386 int sqlite3_wal_checkpoint_v2(
2387   sqlite3 *db,                    /* Database handle */
2388   const char *zDb,                /* Name of attached database (or NULL) */
2389   int eMode,                      /* SQLITE_CHECKPOINT_* value */
2390   int *pnLog,                     /* OUT: Size of WAL log in frames */
2391   int *pnCkpt                     /* OUT: Total number of frames checkpointed */
2392 ){
2393 #ifdef SQLITE_OMIT_WAL
2394   return SQLITE_OK;
2395 #else
2396   int rc;                         /* Return code */
2397   int iDb;                        /* Schema to checkpoint */
2398 
2399 #ifdef SQLITE_ENABLE_API_ARMOR
2400   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
2401 #endif
2402 
2403   /* Initialize the output variables to -1 in case an error occurs. */
2404   if( pnLog ) *pnLog = -1;
2405   if( pnCkpt ) *pnCkpt = -1;
2406 
2407   assert( SQLITE_CHECKPOINT_PASSIVE==0 );
2408   assert( SQLITE_CHECKPOINT_FULL==1 );
2409   assert( SQLITE_CHECKPOINT_RESTART==2 );
2410   assert( SQLITE_CHECKPOINT_TRUNCATE==3 );
2411   if( eMode<SQLITE_CHECKPOINT_PASSIVE || eMode>SQLITE_CHECKPOINT_TRUNCATE ){
2412     /* EVIDENCE-OF: R-03996-12088 The M parameter must be a valid checkpoint
2413     ** mode: */
2414     return SQLITE_MISUSE;
2415   }
2416 
2417   sqlite3_mutex_enter(db->mutex);
2418   if( zDb && zDb[0] ){
2419     iDb = sqlite3FindDbName(db, zDb);
2420   }else{
2421     iDb = SQLITE_MAX_DB;   /* This means process all schemas */
2422   }
2423   if( iDb<0 ){
2424     rc = SQLITE_ERROR;
2425     sqlite3ErrorWithMsg(db, SQLITE_ERROR, "unknown database: %s", zDb);
2426   }else{
2427     db->busyHandler.nBusy = 0;
2428     rc = sqlite3Checkpoint(db, iDb, eMode, pnLog, pnCkpt);
2429     sqlite3Error(db, rc);
2430   }
2431   rc = sqlite3ApiExit(db, rc);
2432 
2433   /* If there are no active statements, clear the interrupt flag at this
2434   ** point.  */
2435   if( db->nVdbeActive==0 ){
2436     AtomicStore(&db->u1.isInterrupted, 0);
2437   }
2438 
2439   sqlite3_mutex_leave(db->mutex);
2440   return rc;
2441 #endif
2442 }
2443 
2444 
2445 /*
2446 ** Checkpoint database zDb. If zDb is NULL, or if the buffer zDb points
2447 ** to contains a zero-length string, all attached databases are
2448 ** checkpointed.
2449 */
2450 int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb){
2451   /* EVIDENCE-OF: R-41613-20553 The sqlite3_wal_checkpoint(D,X) is equivalent to
2452   ** sqlite3_wal_checkpoint_v2(D,X,SQLITE_CHECKPOINT_PASSIVE,0,0). */
2453   return sqlite3_wal_checkpoint_v2(db,zDb,SQLITE_CHECKPOINT_PASSIVE,0,0);
2454 }
2455 
2456 #ifndef SQLITE_OMIT_WAL
2457 /*
2458 ** Run a checkpoint on database iDb. This is a no-op if database iDb is
2459 ** not currently open in WAL mode.
2460 **
2461 ** If a transaction is open on the database being checkpointed, this
2462 ** function returns SQLITE_LOCKED and a checkpoint is not attempted. If
2463 ** an error occurs while running the checkpoint, an SQLite error code is
2464 ** returned (i.e. SQLITE_IOERR). Otherwise, SQLITE_OK.
2465 **
2466 ** The mutex on database handle db should be held by the caller. The mutex
2467 ** associated with the specific b-tree being checkpointed is taken by
2468 ** this function while the checkpoint is running.
2469 **
2470 ** If iDb is passed SQLITE_MAX_DB then all attached databases are
2471 ** checkpointed. If an error is encountered it is returned immediately -
2472 ** no attempt is made to checkpoint any remaining databases.
2473 **
2474 ** Parameter eMode is one of SQLITE_CHECKPOINT_PASSIVE, FULL, RESTART
2475 ** or TRUNCATE.
2476 */
2477 int sqlite3Checkpoint(sqlite3 *db, int iDb, int eMode, int *pnLog, int *pnCkpt){
2478   int rc = SQLITE_OK;             /* Return code */
2479   int i;                          /* Used to iterate through attached dbs */
2480   int bBusy = 0;                  /* True if SQLITE_BUSY has been encountered */
2481 
2482   assert( sqlite3_mutex_held(db->mutex) );
2483   assert( !pnLog || *pnLog==-1 );
2484   assert( !pnCkpt || *pnCkpt==-1 );
2485   testcase( iDb==SQLITE_MAX_ATTACHED ); /* See forum post a006d86f72 */
2486   testcase( iDb==SQLITE_MAX_DB );
2487 
2488   for(i=0; i<db->nDb && rc==SQLITE_OK; i++){
2489     if( i==iDb || iDb==SQLITE_MAX_DB ){
2490       rc = sqlite3BtreeCheckpoint(db->aDb[i].pBt, eMode, pnLog, pnCkpt);
2491       pnLog = 0;
2492       pnCkpt = 0;
2493       if( rc==SQLITE_BUSY ){
2494         bBusy = 1;
2495         rc = SQLITE_OK;
2496       }
2497     }
2498   }
2499 
2500   return (rc==SQLITE_OK && bBusy) ? SQLITE_BUSY : rc;
2501 }
2502 #endif /* SQLITE_OMIT_WAL */
2503 
2504 /*
2505 ** This function returns true if main-memory should be used instead of
2506 ** a temporary file for transient pager files and statement journals.
2507 ** The value returned depends on the value of db->temp_store (runtime
2508 ** parameter) and the compile time value of SQLITE_TEMP_STORE. The
2509 ** following table describes the relationship between these two values
2510 ** and this functions return value.
2511 **
2512 **   SQLITE_TEMP_STORE     db->temp_store     Location of temporary database
2513 **   -----------------     --------------     ------------------------------
2514 **   0                     any                file      (return 0)
2515 **   1                     1                  file      (return 0)
2516 **   1                     2                  memory    (return 1)
2517 **   1                     0                  file      (return 0)
2518 **   2                     1                  file      (return 0)
2519 **   2                     2                  memory    (return 1)
2520 **   2                     0                  memory    (return 1)
2521 **   3                     any                memory    (return 1)
2522 */
2523 int sqlite3TempInMemory(const sqlite3 *db){
2524 #if SQLITE_TEMP_STORE==1
2525   return ( db->temp_store==2 );
2526 #endif
2527 #if SQLITE_TEMP_STORE==2
2528   return ( db->temp_store!=1 );
2529 #endif
2530 #if SQLITE_TEMP_STORE==3
2531   UNUSED_PARAMETER(db);
2532   return 1;
2533 #endif
2534 #if SQLITE_TEMP_STORE<1 || SQLITE_TEMP_STORE>3
2535   UNUSED_PARAMETER(db);
2536   return 0;
2537 #endif
2538 }
2539 
2540 /*
2541 ** Return UTF-8 encoded English language explanation of the most recent
2542 ** error.
2543 */
2544 const char *sqlite3_errmsg(sqlite3 *db){
2545   const char *z;
2546   if( !db ){
2547     return sqlite3ErrStr(SQLITE_NOMEM_BKPT);
2548   }
2549   if( !sqlite3SafetyCheckSickOrOk(db) ){
2550     return sqlite3ErrStr(SQLITE_MISUSE_BKPT);
2551   }
2552   sqlite3_mutex_enter(db->mutex);
2553   if( db->mallocFailed ){
2554     z = sqlite3ErrStr(SQLITE_NOMEM_BKPT);
2555   }else{
2556     testcase( db->pErr==0 );
2557     z = db->errCode ? (char*)sqlite3_value_text(db->pErr) : 0;
2558     assert( !db->mallocFailed );
2559     if( z==0 ){
2560       z = sqlite3ErrStr(db->errCode);
2561     }
2562   }
2563   sqlite3_mutex_leave(db->mutex);
2564   return z;
2565 }
2566 
2567 #ifndef SQLITE_OMIT_UTF16
2568 /*
2569 ** Return UTF-16 encoded English language explanation of the most recent
2570 ** error.
2571 */
2572 const void *sqlite3_errmsg16(sqlite3 *db){
2573   static const u16 outOfMem[] = {
2574     'o', 'u', 't', ' ', 'o', 'f', ' ', 'm', 'e', 'm', 'o', 'r', 'y', 0
2575   };
2576   static const u16 misuse[] = {
2577     'b', 'a', 'd', ' ', 'p', 'a', 'r', 'a', 'm', 'e', 't', 'e', 'r', ' ',
2578     'o', 'r', ' ', 'o', 't', 'h', 'e', 'r', ' ', 'A', 'P', 'I', ' ',
2579     'm', 'i', 's', 'u', 's', 'e', 0
2580   };
2581 
2582   const void *z;
2583   if( !db ){
2584     return (void *)outOfMem;
2585   }
2586   if( !sqlite3SafetyCheckSickOrOk(db) ){
2587     return (void *)misuse;
2588   }
2589   sqlite3_mutex_enter(db->mutex);
2590   if( db->mallocFailed ){
2591     z = (void *)outOfMem;
2592   }else{
2593     z = sqlite3_value_text16(db->pErr);
2594     if( z==0 ){
2595       sqlite3ErrorWithMsg(db, db->errCode, sqlite3ErrStr(db->errCode));
2596       z = sqlite3_value_text16(db->pErr);
2597     }
2598     /* A malloc() may have failed within the call to sqlite3_value_text16()
2599     ** above. If this is the case, then the db->mallocFailed flag needs to
2600     ** be cleared before returning. Do this directly, instead of via
2601     ** sqlite3ApiExit(), to avoid setting the database handle error message.
2602     */
2603     sqlite3OomClear(db);
2604   }
2605   sqlite3_mutex_leave(db->mutex);
2606   return z;
2607 }
2608 #endif /* SQLITE_OMIT_UTF16 */
2609 
2610 /*
2611 ** Return the most recent error code generated by an SQLite routine. If NULL is
2612 ** passed to this function, we assume a malloc() failed during sqlite3_open().
2613 */
2614 int sqlite3_errcode(sqlite3 *db){
2615   if( db && !sqlite3SafetyCheckSickOrOk(db) ){
2616     return SQLITE_MISUSE_BKPT;
2617   }
2618   if( !db || db->mallocFailed ){
2619     return SQLITE_NOMEM_BKPT;
2620   }
2621   return db->errCode & db->errMask;
2622 }
2623 int sqlite3_extended_errcode(sqlite3 *db){
2624   if( db && !sqlite3SafetyCheckSickOrOk(db) ){
2625     return SQLITE_MISUSE_BKPT;
2626   }
2627   if( !db || db->mallocFailed ){
2628     return SQLITE_NOMEM_BKPT;
2629   }
2630   return db->errCode;
2631 }
2632 int sqlite3_system_errno(sqlite3 *db){
2633   return db ? db->iSysErrno : 0;
2634 }
2635 
2636 /*
2637 ** Return a string that describes the kind of error specified in the
2638 ** argument.  For now, this simply calls the internal sqlite3ErrStr()
2639 ** function.
2640 */
2641 const char *sqlite3_errstr(int rc){
2642   return sqlite3ErrStr(rc);
2643 }
2644 
2645 /*
2646 ** Create a new collating function for database "db".  The name is zName
2647 ** and the encoding is enc.
2648 */
2649 static int createCollation(
2650   sqlite3* db,
2651   const char *zName,
2652   u8 enc,
2653   void* pCtx,
2654   int(*xCompare)(void*,int,const void*,int,const void*),
2655   void(*xDel)(void*)
2656 ){
2657   CollSeq *pColl;
2658   int enc2;
2659 
2660   assert( sqlite3_mutex_held(db->mutex) );
2661 
2662   /* If SQLITE_UTF16 is specified as the encoding type, transform this
2663   ** to one of SQLITE_UTF16LE or SQLITE_UTF16BE using the
2664   ** SQLITE_UTF16NATIVE macro. SQLITE_UTF16 is not used internally.
2665   */
2666   enc2 = enc;
2667   testcase( enc2==SQLITE_UTF16 );
2668   testcase( enc2==SQLITE_UTF16_ALIGNED );
2669   if( enc2==SQLITE_UTF16 || enc2==SQLITE_UTF16_ALIGNED ){
2670     enc2 = SQLITE_UTF16NATIVE;
2671   }
2672   if( enc2<SQLITE_UTF8 || enc2>SQLITE_UTF16BE ){
2673     return SQLITE_MISUSE_BKPT;
2674   }
2675 
2676   /* Check if this call is removing or replacing an existing collation
2677   ** sequence. If so, and there are active VMs, return busy. If there
2678   ** are no active VMs, invalidate any pre-compiled statements.
2679   */
2680   pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, 0);
2681   if( pColl && pColl->xCmp ){
2682     if( db->nVdbeActive ){
2683       sqlite3ErrorWithMsg(db, SQLITE_BUSY,
2684         "unable to delete/modify collation sequence due to active statements");
2685       return SQLITE_BUSY;
2686     }
2687     sqlite3ExpirePreparedStatements(db, 0);
2688 
2689     /* If collation sequence pColl was created directly by a call to
2690     ** sqlite3_create_collation, and not generated by synthCollSeq(),
2691     ** then any copies made by synthCollSeq() need to be invalidated.
2692     ** Also, collation destructor - CollSeq.xDel() - function may need
2693     ** to be called.
2694     */
2695     if( (pColl->enc & ~SQLITE_UTF16_ALIGNED)==enc2 ){
2696       CollSeq *aColl = sqlite3HashFind(&db->aCollSeq, zName);
2697       int j;
2698       for(j=0; j<3; j++){
2699         CollSeq *p = &aColl[j];
2700         if( p->enc==pColl->enc ){
2701           if( p->xDel ){
2702             p->xDel(p->pUser);
2703           }
2704           p->xCmp = 0;
2705         }
2706       }
2707     }
2708   }
2709 
2710   pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, 1);
2711   if( pColl==0 ) return SQLITE_NOMEM_BKPT;
2712   pColl->xCmp = xCompare;
2713   pColl->pUser = pCtx;
2714   pColl->xDel = xDel;
2715   pColl->enc = (u8)(enc2 | (enc & SQLITE_UTF16_ALIGNED));
2716   sqlite3Error(db, SQLITE_OK);
2717   return SQLITE_OK;
2718 }
2719 
2720 
2721 /*
2722 ** This array defines hard upper bounds on limit values.  The
2723 ** initializer must be kept in sync with the SQLITE_LIMIT_*
2724 ** #defines in sqlite3.h.
2725 */
2726 static const int aHardLimit[] = {
2727   SQLITE_MAX_LENGTH,
2728   SQLITE_MAX_SQL_LENGTH,
2729   SQLITE_MAX_COLUMN,
2730   SQLITE_MAX_EXPR_DEPTH,
2731   SQLITE_MAX_COMPOUND_SELECT,
2732   SQLITE_MAX_VDBE_OP,
2733   SQLITE_MAX_FUNCTION_ARG,
2734   SQLITE_MAX_ATTACHED,
2735   SQLITE_MAX_LIKE_PATTERN_LENGTH,
2736   SQLITE_MAX_VARIABLE_NUMBER,      /* IMP: R-38091-32352 */
2737   SQLITE_MAX_TRIGGER_DEPTH,
2738   SQLITE_MAX_WORKER_THREADS,
2739 };
2740 
2741 /*
2742 ** Make sure the hard limits are set to reasonable values
2743 */
2744 #if SQLITE_MAX_LENGTH<100
2745 # error SQLITE_MAX_LENGTH must be at least 100
2746 #endif
2747 #if SQLITE_MAX_SQL_LENGTH<100
2748 # error SQLITE_MAX_SQL_LENGTH must be at least 100
2749 #endif
2750 #if SQLITE_MAX_SQL_LENGTH>SQLITE_MAX_LENGTH
2751 # error SQLITE_MAX_SQL_LENGTH must not be greater than SQLITE_MAX_LENGTH
2752 #endif
2753 #if SQLITE_MAX_COMPOUND_SELECT<2
2754 # error SQLITE_MAX_COMPOUND_SELECT must be at least 2
2755 #endif
2756 #if SQLITE_MAX_VDBE_OP<40
2757 # error SQLITE_MAX_VDBE_OP must be at least 40
2758 #endif
2759 #if SQLITE_MAX_FUNCTION_ARG<0 || SQLITE_MAX_FUNCTION_ARG>127
2760 # error SQLITE_MAX_FUNCTION_ARG must be between 0 and 127
2761 #endif
2762 #if SQLITE_MAX_ATTACHED<0 || SQLITE_MAX_ATTACHED>125
2763 # error SQLITE_MAX_ATTACHED must be between 0 and 125
2764 #endif
2765 #if SQLITE_MAX_LIKE_PATTERN_LENGTH<1
2766 # error SQLITE_MAX_LIKE_PATTERN_LENGTH must be at least 1
2767 #endif
2768 #if SQLITE_MAX_COLUMN>32767
2769 # error SQLITE_MAX_COLUMN must not exceed 32767
2770 #endif
2771 #if SQLITE_MAX_TRIGGER_DEPTH<1
2772 # error SQLITE_MAX_TRIGGER_DEPTH must be at least 1
2773 #endif
2774 #if SQLITE_MAX_WORKER_THREADS<0 || SQLITE_MAX_WORKER_THREADS>50
2775 # error SQLITE_MAX_WORKER_THREADS must be between 0 and 50
2776 #endif
2777 
2778 
2779 /*
2780 ** Change the value of a limit.  Report the old value.
2781 ** If an invalid limit index is supplied, report -1.
2782 ** Make no changes but still report the old value if the
2783 ** new limit is negative.
2784 **
2785 ** A new lower limit does not shrink existing constructs.
2786 ** It merely prevents new constructs that exceed the limit
2787 ** from forming.
2788 */
2789 int sqlite3_limit(sqlite3 *db, int limitId, int newLimit){
2790   int oldLimit;
2791 
2792 #ifdef SQLITE_ENABLE_API_ARMOR
2793   if( !sqlite3SafetyCheckOk(db) ){
2794     (void)SQLITE_MISUSE_BKPT;
2795     return -1;
2796   }
2797 #endif
2798 
2799   /* EVIDENCE-OF: R-30189-54097 For each limit category SQLITE_LIMIT_NAME
2800   ** there is a hard upper bound set at compile-time by a C preprocessor
2801   ** macro called SQLITE_MAX_NAME. (The "_LIMIT_" in the name is changed to
2802   ** "_MAX_".)
2803   */
2804   assert( aHardLimit[SQLITE_LIMIT_LENGTH]==SQLITE_MAX_LENGTH );
2805   assert( aHardLimit[SQLITE_LIMIT_SQL_LENGTH]==SQLITE_MAX_SQL_LENGTH );
2806   assert( aHardLimit[SQLITE_LIMIT_COLUMN]==SQLITE_MAX_COLUMN );
2807   assert( aHardLimit[SQLITE_LIMIT_EXPR_DEPTH]==SQLITE_MAX_EXPR_DEPTH );
2808   assert( aHardLimit[SQLITE_LIMIT_COMPOUND_SELECT]==SQLITE_MAX_COMPOUND_SELECT);
2809   assert( aHardLimit[SQLITE_LIMIT_VDBE_OP]==SQLITE_MAX_VDBE_OP );
2810   assert( aHardLimit[SQLITE_LIMIT_FUNCTION_ARG]==SQLITE_MAX_FUNCTION_ARG );
2811   assert( aHardLimit[SQLITE_LIMIT_ATTACHED]==SQLITE_MAX_ATTACHED );
2812   assert( aHardLimit[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]==
2813                                                SQLITE_MAX_LIKE_PATTERN_LENGTH );
2814   assert( aHardLimit[SQLITE_LIMIT_VARIABLE_NUMBER]==SQLITE_MAX_VARIABLE_NUMBER);
2815   assert( aHardLimit[SQLITE_LIMIT_TRIGGER_DEPTH]==SQLITE_MAX_TRIGGER_DEPTH );
2816   assert( aHardLimit[SQLITE_LIMIT_WORKER_THREADS]==SQLITE_MAX_WORKER_THREADS );
2817   assert( SQLITE_LIMIT_WORKER_THREADS==(SQLITE_N_LIMIT-1) );
2818 
2819 
2820   if( limitId<0 || limitId>=SQLITE_N_LIMIT ){
2821     return -1;
2822   }
2823   oldLimit = db->aLimit[limitId];
2824   if( newLimit>=0 ){                   /* IMP: R-52476-28732 */
2825     if( newLimit>aHardLimit[limitId] ){
2826       newLimit = aHardLimit[limitId];  /* IMP: R-51463-25634 */
2827     }
2828     db->aLimit[limitId] = newLimit;
2829   }
2830   return oldLimit;                     /* IMP: R-53341-35419 */
2831 }
2832 
2833 /*
2834 ** This function is used to parse both URIs and non-URI filenames passed by the
2835 ** user to API functions sqlite3_open() or sqlite3_open_v2(), and for database
2836 ** URIs specified as part of ATTACH statements.
2837 **
2838 ** The first argument to this function is the name of the VFS to use (or
2839 ** a NULL to signify the default VFS) if the URI does not contain a "vfs=xxx"
2840 ** query parameter. The second argument contains the URI (or non-URI filename)
2841 ** itself. When this function is called the *pFlags variable should contain
2842 ** the default flags to open the database handle with. The value stored in
2843 ** *pFlags may be updated before returning if the URI filename contains
2844 ** "cache=xxx" or "mode=xxx" query parameters.
2845 **
2846 ** If successful, SQLITE_OK is returned. In this case *ppVfs is set to point to
2847 ** the VFS that should be used to open the database file. *pzFile is set to
2848 ** point to a buffer containing the name of the file to open.  The value
2849 ** stored in *pzFile is a database name acceptable to sqlite3_uri_parameter()
2850 ** and is in the same format as names created using sqlite3_create_filename().
2851 ** The caller must invoke sqlite3_free_filename() (not sqlite3_free()!) on
2852 ** the value returned in *pzFile to avoid a memory leak.
2853 **
2854 ** If an error occurs, then an SQLite error code is returned and *pzErrMsg
2855 ** may be set to point to a buffer containing an English language error
2856 ** message. It is the responsibility of the caller to eventually release
2857 ** this buffer by calling sqlite3_free().
2858 */
2859 int sqlite3ParseUri(
2860   const char *zDefaultVfs,        /* VFS to use if no "vfs=xxx" query option */
2861   const char *zUri,               /* Nul-terminated URI to parse */
2862   unsigned int *pFlags,           /* IN/OUT: SQLITE_OPEN_XXX flags */
2863   sqlite3_vfs **ppVfs,            /* OUT: VFS to use */
2864   char **pzFile,                  /* OUT: Filename component of URI */
2865   char **pzErrMsg                 /* OUT: Error message (if rc!=SQLITE_OK) */
2866 ){
2867   int rc = SQLITE_OK;
2868   unsigned int flags = *pFlags;
2869   const char *zVfs = zDefaultVfs;
2870   char *zFile;
2871   char c;
2872   int nUri = sqlite3Strlen30(zUri);
2873 
2874   assert( *pzErrMsg==0 );
2875 
2876   if( ((flags & SQLITE_OPEN_URI)             /* IMP: R-48725-32206 */
2877             || sqlite3GlobalConfig.bOpenUri) /* IMP: R-51689-46548 */
2878    && nUri>=5 && memcmp(zUri, "file:", 5)==0 /* IMP: R-57884-37496 */
2879   ){
2880     char *zOpt;
2881     int eState;                   /* Parser state when parsing URI */
2882     int iIn;                      /* Input character index */
2883     int iOut = 0;                 /* Output character index */
2884     u64 nByte = nUri+8;           /* Bytes of space to allocate */
2885 
2886     /* Make sure the SQLITE_OPEN_URI flag is set to indicate to the VFS xOpen
2887     ** method that there may be extra parameters following the file-name.  */
2888     flags |= SQLITE_OPEN_URI;
2889 
2890     for(iIn=0; iIn<nUri; iIn++) nByte += (zUri[iIn]=='&');
2891     zFile = sqlite3_malloc64(nByte);
2892     if( !zFile ) return SQLITE_NOMEM_BKPT;
2893 
2894     memset(zFile, 0, 4);  /* 4-byte of 0x00 is the start of DB name marker */
2895     zFile += 4;
2896 
2897     iIn = 5;
2898 #ifdef SQLITE_ALLOW_URI_AUTHORITY
2899     if( strncmp(zUri+5, "///", 3)==0 ){
2900       iIn = 7;
2901       /* The following condition causes URIs with five leading / characters
2902       ** like file://///host/path to be converted into UNCs like //host/path.
2903       ** The correct URI for that UNC has only two or four leading / characters
2904       ** file://host/path or file:////host/path.  But 5 leading slashes is a
2905       ** common error, we are told, so we handle it as a special case. */
2906       if( strncmp(zUri+7, "///", 3)==0 ){ iIn++; }
2907     }else if( strncmp(zUri+5, "//localhost/", 12)==0 ){
2908       iIn = 16;
2909     }
2910 #else
2911     /* Discard the scheme and authority segments of the URI. */
2912     if( zUri[5]=='/' && zUri[6]=='/' ){
2913       iIn = 7;
2914       while( zUri[iIn] && zUri[iIn]!='/' ) iIn++;
2915       if( iIn!=7 && (iIn!=16 || memcmp("localhost", &zUri[7], 9)) ){
2916         *pzErrMsg = sqlite3_mprintf("invalid uri authority: %.*s",
2917             iIn-7, &zUri[7]);
2918         rc = SQLITE_ERROR;
2919         goto parse_uri_out;
2920       }
2921     }
2922 #endif
2923 
2924     /* Copy the filename and any query parameters into the zFile buffer.
2925     ** Decode %HH escape codes along the way.
2926     **
2927     ** Within this loop, variable eState may be set to 0, 1 or 2, depending
2928     ** on the parsing context. As follows:
2929     **
2930     **   0: Parsing file-name.
2931     **   1: Parsing name section of a name=value query parameter.
2932     **   2: Parsing value section of a name=value query parameter.
2933     */
2934     eState = 0;
2935     while( (c = zUri[iIn])!=0 && c!='#' ){
2936       iIn++;
2937       if( c=='%'
2938        && sqlite3Isxdigit(zUri[iIn])
2939        && sqlite3Isxdigit(zUri[iIn+1])
2940       ){
2941         int octet = (sqlite3HexToInt(zUri[iIn++]) << 4);
2942         octet += sqlite3HexToInt(zUri[iIn++]);
2943 
2944         assert( octet>=0 && octet<256 );
2945         if( octet==0 ){
2946 #ifndef SQLITE_ENABLE_URI_00_ERROR
2947           /* This branch is taken when "%00" appears within the URI. In this
2948           ** case we ignore all text in the remainder of the path, name or
2949           ** value currently being parsed. So ignore the current character
2950           ** and skip to the next "?", "=" or "&", as appropriate. */
2951           while( (c = zUri[iIn])!=0 && c!='#'
2952               && (eState!=0 || c!='?')
2953               && (eState!=1 || (c!='=' && c!='&'))
2954               && (eState!=2 || c!='&')
2955           ){
2956             iIn++;
2957           }
2958           continue;
2959 #else
2960           /* If ENABLE_URI_00_ERROR is defined, "%00" in a URI is an error. */
2961           *pzErrMsg = sqlite3_mprintf("unexpected %%00 in uri");
2962           rc = SQLITE_ERROR;
2963           goto parse_uri_out;
2964 #endif
2965         }
2966         c = octet;
2967       }else if( eState==1 && (c=='&' || c=='=') ){
2968         if( zFile[iOut-1]==0 ){
2969           /* An empty option name. Ignore this option altogether. */
2970           while( zUri[iIn] && zUri[iIn]!='#' && zUri[iIn-1]!='&' ) iIn++;
2971           continue;
2972         }
2973         if( c=='&' ){
2974           zFile[iOut++] = '\0';
2975         }else{
2976           eState = 2;
2977         }
2978         c = 0;
2979       }else if( (eState==0 && c=='?') || (eState==2 && c=='&') ){
2980         c = 0;
2981         eState = 1;
2982       }
2983       zFile[iOut++] = c;
2984     }
2985     if( eState==1 ) zFile[iOut++] = '\0';
2986     memset(zFile+iOut, 0, 4); /* end-of-options + empty journal filenames */
2987 
2988     /* Check if there were any options specified that should be interpreted
2989     ** here. Options that are interpreted here include "vfs" and those that
2990     ** correspond to flags that may be passed to the sqlite3_open_v2()
2991     ** method. */
2992     zOpt = &zFile[sqlite3Strlen30(zFile)+1];
2993     while( zOpt[0] ){
2994       int nOpt = sqlite3Strlen30(zOpt);
2995       char *zVal = &zOpt[nOpt+1];
2996       int nVal = sqlite3Strlen30(zVal);
2997 
2998       if( nOpt==3 && memcmp("vfs", zOpt, 3)==0 ){
2999         zVfs = zVal;
3000       }else{
3001         struct OpenMode {
3002           const char *z;
3003           int mode;
3004         } *aMode = 0;
3005         char *zModeType = 0;
3006         int mask = 0;
3007         int limit = 0;
3008 
3009         if( nOpt==5 && memcmp("cache", zOpt, 5)==0 ){
3010           static struct OpenMode aCacheMode[] = {
3011             { "shared",  SQLITE_OPEN_SHAREDCACHE },
3012             { "private", SQLITE_OPEN_PRIVATECACHE },
3013             { 0, 0 }
3014           };
3015 
3016           mask = SQLITE_OPEN_SHAREDCACHE|SQLITE_OPEN_PRIVATECACHE;
3017           aMode = aCacheMode;
3018           limit = mask;
3019           zModeType = "cache";
3020         }
3021         if( nOpt==4 && memcmp("mode", zOpt, 4)==0 ){
3022           static struct OpenMode aOpenMode[] = {
3023             { "ro",  SQLITE_OPEN_READONLY },
3024             { "rw",  SQLITE_OPEN_READWRITE },
3025             { "rwc", SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE },
3026             { "memory", SQLITE_OPEN_MEMORY },
3027             { 0, 0 }
3028           };
3029 
3030           mask = SQLITE_OPEN_READONLY | SQLITE_OPEN_READWRITE
3031                    | SQLITE_OPEN_CREATE | SQLITE_OPEN_MEMORY;
3032           aMode = aOpenMode;
3033           limit = mask & flags;
3034           zModeType = "access";
3035         }
3036 
3037         if( aMode ){
3038           int i;
3039           int mode = 0;
3040           for(i=0; aMode[i].z; i++){
3041             const char *z = aMode[i].z;
3042             if( nVal==sqlite3Strlen30(z) && 0==memcmp(zVal, z, nVal) ){
3043               mode = aMode[i].mode;
3044               break;
3045             }
3046           }
3047           if( mode==0 ){
3048             *pzErrMsg = sqlite3_mprintf("no such %s mode: %s", zModeType, zVal);
3049             rc = SQLITE_ERROR;
3050             goto parse_uri_out;
3051           }
3052           if( (mode & ~SQLITE_OPEN_MEMORY)>limit ){
3053             *pzErrMsg = sqlite3_mprintf("%s mode not allowed: %s",
3054                                         zModeType, zVal);
3055             rc = SQLITE_PERM;
3056             goto parse_uri_out;
3057           }
3058           flags = (flags & ~mask) | mode;
3059         }
3060       }
3061 
3062       zOpt = &zVal[nVal+1];
3063     }
3064 
3065   }else{
3066     zFile = sqlite3_malloc64(nUri+8);
3067     if( !zFile ) return SQLITE_NOMEM_BKPT;
3068     memset(zFile, 0, 4);
3069     zFile += 4;
3070     if( nUri ){
3071       memcpy(zFile, zUri, nUri);
3072     }
3073     memset(zFile+nUri, 0, 4);
3074     flags &= ~SQLITE_OPEN_URI;
3075   }
3076 
3077   *ppVfs = sqlite3_vfs_find(zVfs);
3078   if( *ppVfs==0 ){
3079     *pzErrMsg = sqlite3_mprintf("no such vfs: %s", zVfs);
3080     rc = SQLITE_ERROR;
3081   }
3082  parse_uri_out:
3083   if( rc!=SQLITE_OK ){
3084     sqlite3_free_filename(zFile);
3085     zFile = 0;
3086   }
3087   *pFlags = flags;
3088   *pzFile = zFile;
3089   return rc;
3090 }
3091 
3092 /*
3093 ** This routine does the core work of extracting URI parameters from a
3094 ** database filename for the sqlite3_uri_parameter() interface.
3095 */
3096 static const char *uriParameter(const char *zFilename, const char *zParam){
3097   zFilename += sqlite3Strlen30(zFilename) + 1;
3098   while( ALWAYS(zFilename!=0) && zFilename[0] ){
3099     int x = strcmp(zFilename, zParam);
3100     zFilename += sqlite3Strlen30(zFilename) + 1;
3101     if( x==0 ) return zFilename;
3102     zFilename += sqlite3Strlen30(zFilename) + 1;
3103   }
3104   return 0;
3105 }
3106 
3107 
3108 
3109 /*
3110 ** This routine does the work of opening a database on behalf of
3111 ** sqlite3_open() and sqlite3_open16(). The database filename "zFilename"
3112 ** is UTF-8 encoded.
3113 */
3114 static int openDatabase(
3115   const char *zFilename, /* Database filename UTF-8 encoded */
3116   sqlite3 **ppDb,        /* OUT: Returned database handle */
3117   unsigned int flags,    /* Operational flags */
3118   const char *zVfs       /* Name of the VFS to use */
3119 ){
3120   sqlite3 *db;                    /* Store allocated handle here */
3121   int rc;                         /* Return code */
3122   int isThreadsafe;               /* True for threadsafe connections */
3123   char *zOpen = 0;                /* Filename argument to pass to BtreeOpen() */
3124   char *zErrMsg = 0;              /* Error message from sqlite3ParseUri() */
3125   int i;                          /* Loop counter */
3126 
3127 #ifdef SQLITE_ENABLE_API_ARMOR
3128   if( ppDb==0 ) return SQLITE_MISUSE_BKPT;
3129 #endif
3130   *ppDb = 0;
3131 #ifndef SQLITE_OMIT_AUTOINIT
3132   rc = sqlite3_initialize();
3133   if( rc ) return rc;
3134 #endif
3135 
3136   if( sqlite3GlobalConfig.bCoreMutex==0 ){
3137     isThreadsafe = 0;
3138   }else if( flags & SQLITE_OPEN_NOMUTEX ){
3139     isThreadsafe = 0;
3140   }else if( flags & SQLITE_OPEN_FULLMUTEX ){
3141     isThreadsafe = 1;
3142   }else{
3143     isThreadsafe = sqlite3GlobalConfig.bFullMutex;
3144   }
3145 
3146   if( flags & SQLITE_OPEN_PRIVATECACHE ){
3147     flags &= ~SQLITE_OPEN_SHAREDCACHE;
3148   }else if( sqlite3GlobalConfig.sharedCacheEnabled ){
3149     flags |= SQLITE_OPEN_SHAREDCACHE;
3150   }
3151 
3152   /* Remove harmful bits from the flags parameter
3153   **
3154   ** The SQLITE_OPEN_NOMUTEX and SQLITE_OPEN_FULLMUTEX flags were
3155   ** dealt with in the previous code block.  Besides these, the only
3156   ** valid input flags for sqlite3_open_v2() are SQLITE_OPEN_READONLY,
3157   ** SQLITE_OPEN_READWRITE, SQLITE_OPEN_CREATE, SQLITE_OPEN_SHAREDCACHE,
3158   ** SQLITE_OPEN_PRIVATECACHE, and some reserved bits.  Silently mask
3159   ** off all other flags.
3160   */
3161   flags &=  ~( SQLITE_OPEN_DELETEONCLOSE |
3162                SQLITE_OPEN_MAIN_DB |
3163                SQLITE_OPEN_TEMP_DB |
3164                SQLITE_OPEN_TRANSIENT_DB |
3165                SQLITE_OPEN_MAIN_JOURNAL |
3166                SQLITE_OPEN_TEMP_JOURNAL |
3167                SQLITE_OPEN_SUBJOURNAL |
3168                SQLITE_OPEN_SUPER_JOURNAL |
3169                SQLITE_OPEN_NOMUTEX |
3170                SQLITE_OPEN_FULLMUTEX |
3171                SQLITE_OPEN_WAL
3172              );
3173 
3174   /* Allocate the sqlite data structure */
3175   db = sqlite3MallocZero( sizeof(sqlite3) );
3176   if( db==0 ) goto opendb_out;
3177   if( isThreadsafe
3178 #ifdef SQLITE_ENABLE_MULTITHREADED_CHECKS
3179    || sqlite3GlobalConfig.bCoreMutex
3180 #endif
3181   ){
3182     db->mutex = sqlite3MutexAlloc(SQLITE_MUTEX_RECURSIVE);
3183     if( db->mutex==0 ){
3184       sqlite3_free(db);
3185       db = 0;
3186       goto opendb_out;
3187     }
3188     if( isThreadsafe==0 ){
3189       sqlite3MutexWarnOnContention(db->mutex);
3190     }
3191   }
3192   sqlite3_mutex_enter(db->mutex);
3193   db->errMask = 0xff;
3194   db->nDb = 2;
3195   db->eOpenState = SQLITE_STATE_BUSY;
3196   db->aDb = db->aDbStatic;
3197   db->lookaside.bDisable = 1;
3198   db->lookaside.sz = 0;
3199 
3200   assert( sizeof(db->aLimit)==sizeof(aHardLimit) );
3201   memcpy(db->aLimit, aHardLimit, sizeof(db->aLimit));
3202   db->aLimit[SQLITE_LIMIT_WORKER_THREADS] = SQLITE_DEFAULT_WORKER_THREADS;
3203   db->autoCommit = 1;
3204   db->nextAutovac = -1;
3205   db->szMmap = sqlite3GlobalConfig.szMmap;
3206   db->nextPagesize = 0;
3207   db->init.azInit = sqlite3StdType; /* Any array of string ptrs will do */
3208 #ifdef SQLITE_ENABLE_SORTER_MMAP
3209   /* Beginning with version 3.37.0, using the VFS xFetch() API to memory-map
3210   ** the temporary files used to do external sorts (see code in vdbesort.c)
3211   ** is disabled. It can still be used either by defining
3212   ** SQLITE_ENABLE_SORTER_MMAP at compile time or by using the
3213   ** SQLITE_TESTCTRL_SORTER_MMAP test-control at runtime. */
3214   db->nMaxSorterMmap = 0x7FFFFFFF;
3215 #endif
3216   db->flags |= SQLITE_ShortColNames
3217                  | SQLITE_EnableTrigger
3218                  | SQLITE_EnableView
3219                  | SQLITE_CacheSpill
3220 #if !defined(SQLITE_TRUSTED_SCHEMA) || SQLITE_TRUSTED_SCHEMA+0!=0
3221                  | SQLITE_TrustedSchema
3222 #endif
3223 /* The SQLITE_DQS compile-time option determines the default settings
3224 ** for SQLITE_DBCONFIG_DQS_DDL and SQLITE_DBCONFIG_DQS_DML.
3225 **
3226 **    SQLITE_DQS     SQLITE_DBCONFIG_DQS_DDL    SQLITE_DBCONFIG_DQS_DML
3227 **    ----------     -----------------------    -----------------------
3228 **     undefined               on                          on
3229 **         3                   on                          on
3230 **         2                   on                         off
3231 **         1                  off                          on
3232 **         0                  off                         off
3233 **
3234 ** Legacy behavior is 3 (double-quoted string literals are allowed anywhere)
3235 ** and so that is the default.  But developers are encouranged to use
3236 ** -DSQLITE_DQS=0 (best) or -DSQLITE_DQS=1 (second choice) if possible.
3237 */
3238 #if !defined(SQLITE_DQS)
3239 # define SQLITE_DQS 3
3240 #endif
3241 #if (SQLITE_DQS&1)==1
3242                  | SQLITE_DqsDML
3243 #endif
3244 #if (SQLITE_DQS&2)==2
3245                  | SQLITE_DqsDDL
3246 #endif
3247 
3248 #if !defined(SQLITE_DEFAULT_AUTOMATIC_INDEX) || SQLITE_DEFAULT_AUTOMATIC_INDEX
3249                  | SQLITE_AutoIndex
3250 #endif
3251 #if SQLITE_DEFAULT_CKPTFULLFSYNC
3252                  | SQLITE_CkptFullFSync
3253 #endif
3254 #if SQLITE_DEFAULT_FILE_FORMAT<4
3255                  | SQLITE_LegacyFileFmt
3256 #endif
3257 #ifdef SQLITE_ENABLE_LOAD_EXTENSION
3258                  | SQLITE_LoadExtension
3259 #endif
3260 #if SQLITE_DEFAULT_RECURSIVE_TRIGGERS
3261                  | SQLITE_RecTriggers
3262 #endif
3263 #if defined(SQLITE_DEFAULT_FOREIGN_KEYS) && SQLITE_DEFAULT_FOREIGN_KEYS
3264                  | SQLITE_ForeignKeys
3265 #endif
3266 #if defined(SQLITE_REVERSE_UNORDERED_SELECTS)
3267                  | SQLITE_ReverseOrder
3268 #endif
3269 #if defined(SQLITE_ENABLE_OVERSIZE_CELL_CHECK)
3270                  | SQLITE_CellSizeCk
3271 #endif
3272 #if defined(SQLITE_ENABLE_FTS3_TOKENIZER)
3273                  | SQLITE_Fts3Tokenizer
3274 #endif
3275 #if defined(SQLITE_ENABLE_QPSG)
3276                  | SQLITE_EnableQPSG
3277 #endif
3278 #if defined(SQLITE_DEFAULT_DEFENSIVE)
3279                  | SQLITE_Defensive
3280 #endif
3281 #if defined(SQLITE_DEFAULT_LEGACY_ALTER_TABLE)
3282                  | SQLITE_LegacyAlter
3283 #endif
3284       ;
3285   sqlite3HashInit(&db->aCollSeq);
3286 #ifndef SQLITE_OMIT_VIRTUALTABLE
3287   sqlite3HashInit(&db->aModule);
3288 #endif
3289 
3290   /* Add the default collation sequence BINARY. BINARY works for both UTF-8
3291   ** and UTF-16, so add a version for each to avoid any unnecessary
3292   ** conversions. The only error that can occur here is a malloc() failure.
3293   **
3294   ** EVIDENCE-OF: R-52786-44878 SQLite defines three built-in collating
3295   ** functions:
3296   */
3297   createCollation(db, sqlite3StrBINARY, SQLITE_UTF8, 0, binCollFunc, 0);
3298   createCollation(db, sqlite3StrBINARY, SQLITE_UTF16BE, 0, binCollFunc, 0);
3299   createCollation(db, sqlite3StrBINARY, SQLITE_UTF16LE, 0, binCollFunc, 0);
3300   createCollation(db, "NOCASE", SQLITE_UTF8, 0, nocaseCollatingFunc, 0);
3301   createCollation(db, "RTRIM", SQLITE_UTF8, 0, rtrimCollFunc, 0);
3302   if( db->mallocFailed ){
3303     goto opendb_out;
3304   }
3305 
3306   /* Parse the filename/URI argument
3307   **
3308   ** Only allow sensible combinations of bits in the flags argument.
3309   ** Throw an error if any non-sense combination is used.  If we
3310   ** do not block illegal combinations here, it could trigger
3311   ** assert() statements in deeper layers.  Sensible combinations
3312   ** are:
3313   **
3314   **  1:  SQLITE_OPEN_READONLY
3315   **  2:  SQLITE_OPEN_READWRITE
3316   **  6:  SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE
3317   */
3318   db->openFlags = flags;
3319   assert( SQLITE_OPEN_READONLY  == 0x01 );
3320   assert( SQLITE_OPEN_READWRITE == 0x02 );
3321   assert( SQLITE_OPEN_CREATE    == 0x04 );
3322   testcase( (1<<(flags&7))==0x02 ); /* READONLY */
3323   testcase( (1<<(flags&7))==0x04 ); /* READWRITE */
3324   testcase( (1<<(flags&7))==0x40 ); /* READWRITE | CREATE */
3325   if( ((1<<(flags&7)) & 0x46)==0 ){
3326     rc = SQLITE_MISUSE_BKPT;  /* IMP: R-18321-05872 */
3327   }else{
3328     rc = sqlite3ParseUri(zVfs, zFilename, &flags, &db->pVfs, &zOpen, &zErrMsg);
3329   }
3330   if( rc!=SQLITE_OK ){
3331     if( rc==SQLITE_NOMEM ) sqlite3OomFault(db);
3332     sqlite3ErrorWithMsg(db, rc, zErrMsg ? "%s" : 0, zErrMsg);
3333     sqlite3_free(zErrMsg);
3334     goto opendb_out;
3335   }
3336 
3337   /* Open the backend database driver */
3338   rc = sqlite3BtreeOpen(db->pVfs, zOpen, db, &db->aDb[0].pBt, 0,
3339                         flags | SQLITE_OPEN_MAIN_DB);
3340   if( rc!=SQLITE_OK ){
3341     if( rc==SQLITE_IOERR_NOMEM ){
3342       rc = SQLITE_NOMEM_BKPT;
3343     }
3344     sqlite3Error(db, rc);
3345     goto opendb_out;
3346   }
3347   sqlite3BtreeEnter(db->aDb[0].pBt);
3348   db->aDb[0].pSchema = sqlite3SchemaGet(db, db->aDb[0].pBt);
3349   if( !db->mallocFailed ){
3350     sqlite3SetTextEncoding(db, SCHEMA_ENC(db));
3351   }
3352   sqlite3BtreeLeave(db->aDb[0].pBt);
3353   db->aDb[1].pSchema = sqlite3SchemaGet(db, 0);
3354 
3355   /* The default safety_level for the main database is FULL; for the temp
3356   ** database it is OFF. This matches the pager layer defaults.
3357   */
3358   db->aDb[0].zDbSName = "main";
3359   db->aDb[0].safety_level = SQLITE_DEFAULT_SYNCHRONOUS+1;
3360   db->aDb[1].zDbSName = "temp";
3361   db->aDb[1].safety_level = PAGER_SYNCHRONOUS_OFF;
3362 
3363   db->eOpenState = SQLITE_STATE_OPEN;
3364   if( db->mallocFailed ){
3365     goto opendb_out;
3366   }
3367 
3368   /* Register all built-in functions, but do not attempt to read the
3369   ** database schema yet. This is delayed until the first time the database
3370   ** is accessed.
3371   */
3372   sqlite3Error(db, SQLITE_OK);
3373   sqlite3RegisterPerConnectionBuiltinFunctions(db);
3374   rc = sqlite3_errcode(db);
3375 
3376 
3377   /* Load compiled-in extensions */
3378   for(i=0; rc==SQLITE_OK && i<ArraySize(sqlite3BuiltinExtensions); i++){
3379     rc = sqlite3BuiltinExtensions[i](db);
3380   }
3381 
3382   /* Load automatic extensions - extensions that have been registered
3383   ** using the sqlite3_automatic_extension() API.
3384   */
3385   if( rc==SQLITE_OK ){
3386     sqlite3AutoLoadExtensions(db);
3387     rc = sqlite3_errcode(db);
3388     if( rc!=SQLITE_OK ){
3389       goto opendb_out;
3390     }
3391   }
3392 
3393 #ifdef SQLITE_ENABLE_INTERNAL_FUNCTIONS
3394   /* Testing use only!!! The -DSQLITE_ENABLE_INTERNAL_FUNCTIONS=1 compile-time
3395   ** option gives access to internal functions by default.
3396   ** Testing use only!!! */
3397   db->mDbFlags |= DBFLAG_InternalFunc;
3398 #endif
3399 
3400   /* -DSQLITE_DEFAULT_LOCKING_MODE=1 makes EXCLUSIVE the default locking
3401   ** mode.  -DSQLITE_DEFAULT_LOCKING_MODE=0 make NORMAL the default locking
3402   ** mode.  Doing nothing at all also makes NORMAL the default.
3403   */
3404 #ifdef SQLITE_DEFAULT_LOCKING_MODE
3405   db->dfltLockMode = SQLITE_DEFAULT_LOCKING_MODE;
3406   sqlite3PagerLockingMode(sqlite3BtreePager(db->aDb[0].pBt),
3407                           SQLITE_DEFAULT_LOCKING_MODE);
3408 #endif
3409 
3410   if( rc ) sqlite3Error(db, rc);
3411 
3412   /* Enable the lookaside-malloc subsystem */
3413   setupLookaside(db, 0, sqlite3GlobalConfig.szLookaside,
3414                         sqlite3GlobalConfig.nLookaside);
3415 
3416   sqlite3_wal_autocheckpoint(db, SQLITE_DEFAULT_WAL_AUTOCHECKPOINT);
3417 
3418 opendb_out:
3419   if( db ){
3420     assert( db->mutex!=0 || isThreadsafe==0
3421            || sqlite3GlobalConfig.bFullMutex==0 );
3422     sqlite3_mutex_leave(db->mutex);
3423   }
3424   rc = sqlite3_errcode(db);
3425   assert( db!=0 || rc==SQLITE_NOMEM );
3426   if( rc==SQLITE_NOMEM ){
3427     sqlite3_close(db);
3428     db = 0;
3429   }else if( rc!=SQLITE_OK ){
3430     db->eOpenState = SQLITE_STATE_SICK;
3431   }
3432   *ppDb = db;
3433 #ifdef SQLITE_ENABLE_SQLLOG
3434   if( sqlite3GlobalConfig.xSqllog ){
3435     /* Opening a db handle. Fourth parameter is passed 0. */
3436     void *pArg = sqlite3GlobalConfig.pSqllogArg;
3437     sqlite3GlobalConfig.xSqllog(pArg, db, zFilename, 0);
3438   }
3439 #endif
3440   sqlite3_free_filename(zOpen);
3441   return rc & 0xff;
3442 }
3443 
3444 
3445 /*
3446 ** Open a new database handle.
3447 */
3448 int sqlite3_open(
3449   const char *zFilename,
3450   sqlite3 **ppDb
3451 ){
3452   return openDatabase(zFilename, ppDb,
3453                       SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
3454 }
3455 int sqlite3_open_v2(
3456   const char *filename,   /* Database filename (UTF-8) */
3457   sqlite3 **ppDb,         /* OUT: SQLite db handle */
3458   int flags,              /* Flags */
3459   const char *zVfs        /* Name of VFS module to use */
3460 ){
3461   return openDatabase(filename, ppDb, (unsigned int)flags, zVfs);
3462 }
3463 
3464 #ifndef SQLITE_OMIT_UTF16
3465 /*
3466 ** Open a new database handle.
3467 */
3468 int sqlite3_open16(
3469   const void *zFilename,
3470   sqlite3 **ppDb
3471 ){
3472   char const *zFilename8;   /* zFilename encoded in UTF-8 instead of UTF-16 */
3473   sqlite3_value *pVal;
3474   int rc;
3475 
3476 #ifdef SQLITE_ENABLE_API_ARMOR
3477   if( ppDb==0 ) return SQLITE_MISUSE_BKPT;
3478 #endif
3479   *ppDb = 0;
3480 #ifndef SQLITE_OMIT_AUTOINIT
3481   rc = sqlite3_initialize();
3482   if( rc ) return rc;
3483 #endif
3484   if( zFilename==0 ) zFilename = "\000\000";
3485   pVal = sqlite3ValueNew(0);
3486   sqlite3ValueSetStr(pVal, -1, zFilename, SQLITE_UTF16NATIVE, SQLITE_STATIC);
3487   zFilename8 = sqlite3ValueText(pVal, SQLITE_UTF8);
3488   if( zFilename8 ){
3489     rc = openDatabase(zFilename8, ppDb,
3490                       SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
3491     assert( *ppDb || rc==SQLITE_NOMEM );
3492     if( rc==SQLITE_OK && !DbHasProperty(*ppDb, 0, DB_SchemaLoaded) ){
3493       SCHEMA_ENC(*ppDb) = ENC(*ppDb) = SQLITE_UTF16NATIVE;
3494     }
3495   }else{
3496     rc = SQLITE_NOMEM_BKPT;
3497   }
3498   sqlite3ValueFree(pVal);
3499 
3500   return rc & 0xff;
3501 }
3502 #endif /* SQLITE_OMIT_UTF16 */
3503 
3504 /*
3505 ** Register a new collation sequence with the database handle db.
3506 */
3507 int sqlite3_create_collation(
3508   sqlite3* db,
3509   const char *zName,
3510   int enc,
3511   void* pCtx,
3512   int(*xCompare)(void*,int,const void*,int,const void*)
3513 ){
3514   return sqlite3_create_collation_v2(db, zName, enc, pCtx, xCompare, 0);
3515 }
3516 
3517 /*
3518 ** Register a new collation sequence with the database handle db.
3519 */
3520 int sqlite3_create_collation_v2(
3521   sqlite3* db,
3522   const char *zName,
3523   int enc,
3524   void* pCtx,
3525   int(*xCompare)(void*,int,const void*,int,const void*),
3526   void(*xDel)(void*)
3527 ){
3528   int rc;
3529 
3530 #ifdef SQLITE_ENABLE_API_ARMOR
3531   if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
3532 #endif
3533   sqlite3_mutex_enter(db->mutex);
3534   assert( !db->mallocFailed );
3535   rc = createCollation(db, zName, (u8)enc, pCtx, xCompare, xDel);
3536   rc = sqlite3ApiExit(db, rc);
3537   sqlite3_mutex_leave(db->mutex);
3538   return rc;
3539 }
3540 
3541 #ifndef SQLITE_OMIT_UTF16
3542 /*
3543 ** Register a new collation sequence with the database handle db.
3544 */
3545 int sqlite3_create_collation16(
3546   sqlite3* db,
3547   const void *zName,
3548   int enc,
3549   void* pCtx,
3550   int(*xCompare)(void*,int,const void*,int,const void*)
3551 ){
3552   int rc = SQLITE_OK;
3553   char *zName8;
3554 
3555 #ifdef SQLITE_ENABLE_API_ARMOR
3556   if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
3557 #endif
3558   sqlite3_mutex_enter(db->mutex);
3559   assert( !db->mallocFailed );
3560   zName8 = sqlite3Utf16to8(db, zName, -1, SQLITE_UTF16NATIVE);
3561   if( zName8 ){
3562     rc = createCollation(db, zName8, (u8)enc, pCtx, xCompare, 0);
3563     sqlite3DbFree(db, zName8);
3564   }
3565   rc = sqlite3ApiExit(db, rc);
3566   sqlite3_mutex_leave(db->mutex);
3567   return rc;
3568 }
3569 #endif /* SQLITE_OMIT_UTF16 */
3570 
3571 /*
3572 ** Register a collation sequence factory callback with the database handle
3573 ** db. Replace any previously installed collation sequence factory.
3574 */
3575 int sqlite3_collation_needed(
3576   sqlite3 *db,
3577   void *pCollNeededArg,
3578   void(*xCollNeeded)(void*,sqlite3*,int eTextRep,const char*)
3579 ){
3580 #ifdef SQLITE_ENABLE_API_ARMOR
3581   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3582 #endif
3583   sqlite3_mutex_enter(db->mutex);
3584   db->xCollNeeded = xCollNeeded;
3585   db->xCollNeeded16 = 0;
3586   db->pCollNeededArg = pCollNeededArg;
3587   sqlite3_mutex_leave(db->mutex);
3588   return SQLITE_OK;
3589 }
3590 
3591 #ifndef SQLITE_OMIT_UTF16
3592 /*
3593 ** Register a collation sequence factory callback with the database handle
3594 ** db. Replace any previously installed collation sequence factory.
3595 */
3596 int sqlite3_collation_needed16(
3597   sqlite3 *db,
3598   void *pCollNeededArg,
3599   void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*)
3600 ){
3601 #ifdef SQLITE_ENABLE_API_ARMOR
3602   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3603 #endif
3604   sqlite3_mutex_enter(db->mutex);
3605   db->xCollNeeded = 0;
3606   db->xCollNeeded16 = xCollNeeded16;
3607   db->pCollNeededArg = pCollNeededArg;
3608   sqlite3_mutex_leave(db->mutex);
3609   return SQLITE_OK;
3610 }
3611 #endif /* SQLITE_OMIT_UTF16 */
3612 
3613 #ifndef SQLITE_OMIT_DEPRECATED
3614 /*
3615 ** This function is now an anachronism. It used to be used to recover from a
3616 ** malloc() failure, but SQLite now does this automatically.
3617 */
3618 int sqlite3_global_recover(void){
3619   return SQLITE_OK;
3620 }
3621 #endif
3622 
3623 /*
3624 ** Test to see whether or not the database connection is in autocommit
3625 ** mode.  Return TRUE if it is and FALSE if not.  Autocommit mode is on
3626 ** by default.  Autocommit is disabled by a BEGIN statement and reenabled
3627 ** by the next COMMIT or ROLLBACK.
3628 */
3629 int sqlite3_get_autocommit(sqlite3 *db){
3630 #ifdef SQLITE_ENABLE_API_ARMOR
3631   if( !sqlite3SafetyCheckOk(db) ){
3632     (void)SQLITE_MISUSE_BKPT;
3633     return 0;
3634   }
3635 #endif
3636   return db->autoCommit;
3637 }
3638 
3639 /*
3640 ** The following routines are substitutes for constants SQLITE_CORRUPT,
3641 ** SQLITE_MISUSE, SQLITE_CANTOPEN, SQLITE_NOMEM and possibly other error
3642 ** constants.  They serve two purposes:
3643 **
3644 **   1.  Serve as a convenient place to set a breakpoint in a debugger
3645 **       to detect when version error conditions occurs.
3646 **
3647 **   2.  Invoke sqlite3_log() to provide the source code location where
3648 **       a low-level error is first detected.
3649 */
3650 int sqlite3ReportError(int iErr, int lineno, const char *zType){
3651   sqlite3_log(iErr, "%s at line %d of [%.10s]",
3652               zType, lineno, 20+sqlite3_sourceid());
3653   return iErr;
3654 }
3655 int sqlite3CorruptError(int lineno){
3656   testcase( sqlite3GlobalConfig.xLog!=0 );
3657   return sqlite3ReportError(SQLITE_CORRUPT, lineno, "database corruption");
3658 }
3659 int sqlite3MisuseError(int lineno){
3660   testcase( sqlite3GlobalConfig.xLog!=0 );
3661   return sqlite3ReportError(SQLITE_MISUSE, lineno, "misuse");
3662 }
3663 int sqlite3CantopenError(int lineno){
3664   testcase( sqlite3GlobalConfig.xLog!=0 );
3665   return sqlite3ReportError(SQLITE_CANTOPEN, lineno, "cannot open file");
3666 }
3667 #if defined(SQLITE_DEBUG) || defined(SQLITE_ENABLE_CORRUPT_PGNO)
3668 int sqlite3CorruptPgnoError(int lineno, Pgno pgno){
3669   char zMsg[100];
3670   sqlite3_snprintf(sizeof(zMsg), zMsg, "database corruption page %d", pgno);
3671   testcase( sqlite3GlobalConfig.xLog!=0 );
3672   return sqlite3ReportError(SQLITE_CORRUPT, lineno, zMsg);
3673 }
3674 #endif
3675 #ifdef SQLITE_DEBUG
3676 int sqlite3NomemError(int lineno){
3677   testcase( sqlite3GlobalConfig.xLog!=0 );
3678   return sqlite3ReportError(SQLITE_NOMEM, lineno, "OOM");
3679 }
3680 int sqlite3IoerrnomemError(int lineno){
3681   testcase( sqlite3GlobalConfig.xLog!=0 );
3682   return sqlite3ReportError(SQLITE_IOERR_NOMEM, lineno, "I/O OOM error");
3683 }
3684 #endif
3685 
3686 #ifndef SQLITE_OMIT_DEPRECATED
3687 /*
3688 ** This is a convenience routine that makes sure that all thread-specific
3689 ** data for this thread has been deallocated.
3690 **
3691 ** SQLite no longer uses thread-specific data so this routine is now a
3692 ** no-op.  It is retained for historical compatibility.
3693 */
3694 void sqlite3_thread_cleanup(void){
3695 }
3696 #endif
3697 
3698 /*
3699 ** Return meta information about a specific column of a database table.
3700 ** See comment in sqlite3.h (sqlite.h.in) for details.
3701 */
3702 int sqlite3_table_column_metadata(
3703   sqlite3 *db,                /* Connection handle */
3704   const char *zDbName,        /* Database name or NULL */
3705   const char *zTableName,     /* Table name */
3706   const char *zColumnName,    /* Column name */
3707   char const **pzDataType,    /* OUTPUT: Declared data type */
3708   char const **pzCollSeq,     /* OUTPUT: Collation sequence name */
3709   int *pNotNull,              /* OUTPUT: True if NOT NULL constraint exists */
3710   int *pPrimaryKey,           /* OUTPUT: True if column part of PK */
3711   int *pAutoinc               /* OUTPUT: True if column is auto-increment */
3712 ){
3713   int rc;
3714   char *zErrMsg = 0;
3715   Table *pTab = 0;
3716   Column *pCol = 0;
3717   int iCol = 0;
3718   char const *zDataType = 0;
3719   char const *zCollSeq = 0;
3720   int notnull = 0;
3721   int primarykey = 0;
3722   int autoinc = 0;
3723 
3724 
3725 #ifdef SQLITE_ENABLE_API_ARMOR
3726   if( !sqlite3SafetyCheckOk(db) || zTableName==0 ){
3727     return SQLITE_MISUSE_BKPT;
3728   }
3729 #endif
3730 
3731   /* Ensure the database schema has been loaded */
3732   sqlite3_mutex_enter(db->mutex);
3733   sqlite3BtreeEnterAll(db);
3734   rc = sqlite3Init(db, &zErrMsg);
3735   if( SQLITE_OK!=rc ){
3736     goto error_out;
3737   }
3738 
3739   /* Locate the table in question */
3740   pTab = sqlite3FindTable(db, zTableName, zDbName);
3741   if( !pTab || IsView(pTab) ){
3742     pTab = 0;
3743     goto error_out;
3744   }
3745 
3746   /* Find the column for which info is requested */
3747   if( zColumnName==0 ){
3748     /* Query for existance of table only */
3749   }else{
3750     for(iCol=0; iCol<pTab->nCol; iCol++){
3751       pCol = &pTab->aCol[iCol];
3752       if( 0==sqlite3StrICmp(pCol->zCnName, zColumnName) ){
3753         break;
3754       }
3755     }
3756     if( iCol==pTab->nCol ){
3757       if( HasRowid(pTab) && sqlite3IsRowid(zColumnName) ){
3758         iCol = pTab->iPKey;
3759         pCol = iCol>=0 ? &pTab->aCol[iCol] : 0;
3760       }else{
3761         pTab = 0;
3762         goto error_out;
3763       }
3764     }
3765   }
3766 
3767   /* The following block stores the meta information that will be returned
3768   ** to the caller in local variables zDataType, zCollSeq, notnull, primarykey
3769   ** and autoinc. At this point there are two possibilities:
3770   **
3771   **     1. The specified column name was rowid", "oid" or "_rowid_"
3772   **        and there is no explicitly declared IPK column.
3773   **
3774   **     2. The table is not a view and the column name identified an
3775   **        explicitly declared column. Copy meta information from *pCol.
3776   */
3777   if( pCol ){
3778     zDataType = sqlite3ColumnType(pCol,0);
3779     zCollSeq = sqlite3ColumnColl(pCol);
3780     notnull = pCol->notNull!=0;
3781     primarykey  = (pCol->colFlags & COLFLAG_PRIMKEY)!=0;
3782     autoinc = pTab->iPKey==iCol && (pTab->tabFlags & TF_Autoincrement)!=0;
3783   }else{
3784     zDataType = "INTEGER";
3785     primarykey = 1;
3786   }
3787   if( !zCollSeq ){
3788     zCollSeq = sqlite3StrBINARY;
3789   }
3790 
3791 error_out:
3792   sqlite3BtreeLeaveAll(db);
3793 
3794   /* Whether the function call succeeded or failed, set the output parameters
3795   ** to whatever their local counterparts contain. If an error did occur,
3796   ** this has the effect of zeroing all output parameters.
3797   */
3798   if( pzDataType ) *pzDataType = zDataType;
3799   if( pzCollSeq ) *pzCollSeq = zCollSeq;
3800   if( pNotNull ) *pNotNull = notnull;
3801   if( pPrimaryKey ) *pPrimaryKey = primarykey;
3802   if( pAutoinc ) *pAutoinc = autoinc;
3803 
3804   if( SQLITE_OK==rc && !pTab ){
3805     sqlite3DbFree(db, zErrMsg);
3806     zErrMsg = sqlite3MPrintf(db, "no such table column: %s.%s", zTableName,
3807         zColumnName);
3808     rc = SQLITE_ERROR;
3809   }
3810   sqlite3ErrorWithMsg(db, rc, (zErrMsg?"%s":0), zErrMsg);
3811   sqlite3DbFree(db, zErrMsg);
3812   rc = sqlite3ApiExit(db, rc);
3813   sqlite3_mutex_leave(db->mutex);
3814   return rc;
3815 }
3816 
3817 /*
3818 ** Sleep for a little while.  Return the amount of time slept.
3819 */
3820 int sqlite3_sleep(int ms){
3821   sqlite3_vfs *pVfs;
3822   int rc;
3823   pVfs = sqlite3_vfs_find(0);
3824   if( pVfs==0 ) return 0;
3825 
3826   /* This function works in milliseconds, but the underlying OsSleep()
3827   ** API uses microseconds. Hence the 1000's.
3828   */
3829   rc = (sqlite3OsSleep(pVfs, 1000*ms)/1000);
3830   return rc;
3831 }
3832 
3833 /*
3834 ** Enable or disable the extended result codes.
3835 */
3836 int sqlite3_extended_result_codes(sqlite3 *db, int onoff){
3837 #ifdef SQLITE_ENABLE_API_ARMOR
3838   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3839 #endif
3840   sqlite3_mutex_enter(db->mutex);
3841   db->errMask = onoff ? 0xffffffff : 0xff;
3842   sqlite3_mutex_leave(db->mutex);
3843   return SQLITE_OK;
3844 }
3845 
3846 /*
3847 ** Invoke the xFileControl method on a particular database.
3848 */
3849 int sqlite3_file_control(sqlite3 *db, const char *zDbName, int op, void *pArg){
3850   int rc = SQLITE_ERROR;
3851   Btree *pBtree;
3852 
3853 #ifdef SQLITE_ENABLE_API_ARMOR
3854   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3855 #endif
3856   sqlite3_mutex_enter(db->mutex);
3857   pBtree = sqlite3DbNameToBtree(db, zDbName);
3858   if( pBtree ){
3859     Pager *pPager;
3860     sqlite3_file *fd;
3861     sqlite3BtreeEnter(pBtree);
3862     pPager = sqlite3BtreePager(pBtree);
3863     assert( pPager!=0 );
3864     fd = sqlite3PagerFile(pPager);
3865     assert( fd!=0 );
3866     if( op==SQLITE_FCNTL_FILE_POINTER ){
3867       *(sqlite3_file**)pArg = fd;
3868       rc = SQLITE_OK;
3869     }else if( op==SQLITE_FCNTL_VFS_POINTER ){
3870       *(sqlite3_vfs**)pArg = sqlite3PagerVfs(pPager);
3871       rc = SQLITE_OK;
3872     }else if( op==SQLITE_FCNTL_JOURNAL_POINTER ){
3873       *(sqlite3_file**)pArg = sqlite3PagerJrnlFile(pPager);
3874       rc = SQLITE_OK;
3875     }else if( op==SQLITE_FCNTL_DATA_VERSION ){
3876       *(unsigned int*)pArg = sqlite3PagerDataVersion(pPager);
3877       rc = SQLITE_OK;
3878     }else if( op==SQLITE_FCNTL_RESERVE_BYTES ){
3879       int iNew = *(int*)pArg;
3880       *(int*)pArg = sqlite3BtreeGetRequestedReserve(pBtree);
3881       if( iNew>=0 && iNew<=255 ){
3882         sqlite3BtreeSetPageSize(pBtree, 0, iNew, 0);
3883       }
3884       rc = SQLITE_OK;
3885     }else{
3886       int nSave = db->busyHandler.nBusy;
3887       rc = sqlite3OsFileControl(fd, op, pArg);
3888       db->busyHandler.nBusy = nSave;
3889     }
3890     sqlite3BtreeLeave(pBtree);
3891   }
3892   sqlite3_mutex_leave(db->mutex);
3893   return rc;
3894 }
3895 
3896 /*
3897 ** Interface to the testing logic.
3898 */
3899 int sqlite3_test_control(int op, ...){
3900   int rc = 0;
3901 #ifdef SQLITE_UNTESTABLE
3902   UNUSED_PARAMETER(op);
3903 #else
3904   va_list ap;
3905   va_start(ap, op);
3906   switch( op ){
3907 
3908     /*
3909     ** Save the current state of the PRNG.
3910     */
3911     case SQLITE_TESTCTRL_PRNG_SAVE: {
3912       sqlite3PrngSaveState();
3913       break;
3914     }
3915 
3916     /*
3917     ** Restore the state of the PRNG to the last state saved using
3918     ** PRNG_SAVE.  If PRNG_SAVE has never before been called, then
3919     ** this verb acts like PRNG_RESET.
3920     */
3921     case SQLITE_TESTCTRL_PRNG_RESTORE: {
3922       sqlite3PrngRestoreState();
3923       break;
3924     }
3925 
3926     /*  sqlite3_test_control(SQLITE_TESTCTRL_PRNG_SEED, int x, sqlite3 *db);
3927     **
3928     ** Control the seed for the pseudo-random number generator (PRNG) that
3929     ** is built into SQLite.  Cases:
3930     **
3931     **    x!=0 && db!=0       Seed the PRNG to the current value of the
3932     **                        schema cookie in the main database for db, or
3933     **                        x if the schema cookie is zero.  This case
3934     **                        is convenient to use with database fuzzers
3935     **                        as it allows the fuzzer some control over the
3936     **                        the PRNG seed.
3937     **
3938     **    x!=0 && db==0       Seed the PRNG to the value of x.
3939     **
3940     **    x==0 && db==0       Revert to default behavior of using the
3941     **                        xRandomness method on the primary VFS.
3942     **
3943     ** This test-control also resets the PRNG so that the new seed will
3944     ** be used for the next call to sqlite3_randomness().
3945     */
3946 #ifndef SQLITE_OMIT_WSD
3947     case SQLITE_TESTCTRL_PRNG_SEED: {
3948       int x = va_arg(ap, int);
3949       int y;
3950       sqlite3 *db = va_arg(ap, sqlite3*);
3951       assert( db==0 || db->aDb[0].pSchema!=0 );
3952       if( db && (y = db->aDb[0].pSchema->schema_cookie)!=0 ){ x = y; }
3953       sqlite3Config.iPrngSeed = x;
3954       sqlite3_randomness(0,0);
3955       break;
3956     }
3957 #endif
3958 
3959     /*
3960     **  sqlite3_test_control(BITVEC_TEST, size, program)
3961     **
3962     ** Run a test against a Bitvec object of size.  The program argument
3963     ** is an array of integers that defines the test.  Return -1 on a
3964     ** memory allocation error, 0 on success, or non-zero for an error.
3965     ** See the sqlite3BitvecBuiltinTest() for additional information.
3966     */
3967     case SQLITE_TESTCTRL_BITVEC_TEST: {
3968       int sz = va_arg(ap, int);
3969       int *aProg = va_arg(ap, int*);
3970       rc = sqlite3BitvecBuiltinTest(sz, aProg);
3971       break;
3972     }
3973 
3974     /*
3975     **  sqlite3_test_control(FAULT_INSTALL, xCallback)
3976     **
3977     ** Arrange to invoke xCallback() whenever sqlite3FaultSim() is called,
3978     ** if xCallback is not NULL.
3979     **
3980     ** As a test of the fault simulator mechanism itself, sqlite3FaultSim(0)
3981     ** is called immediately after installing the new callback and the return
3982     ** value from sqlite3FaultSim(0) becomes the return from
3983     ** sqlite3_test_control().
3984     */
3985     case SQLITE_TESTCTRL_FAULT_INSTALL: {
3986       /* MSVC is picky about pulling func ptrs from va lists.
3987       ** http://support.microsoft.com/kb/47961
3988       ** sqlite3GlobalConfig.xTestCallback = va_arg(ap, int(*)(int));
3989       */
3990       typedef int(*TESTCALLBACKFUNC_t)(int);
3991       sqlite3GlobalConfig.xTestCallback = va_arg(ap, TESTCALLBACKFUNC_t);
3992       rc = sqlite3FaultSim(0);
3993       break;
3994     }
3995 
3996     /*
3997     **  sqlite3_test_control(BENIGN_MALLOC_HOOKS, xBegin, xEnd)
3998     **
3999     ** Register hooks to call to indicate which malloc() failures
4000     ** are benign.
4001     */
4002     case SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS: {
4003       typedef void (*void_function)(void);
4004       void_function xBenignBegin;
4005       void_function xBenignEnd;
4006       xBenignBegin = va_arg(ap, void_function);
4007       xBenignEnd = va_arg(ap, void_function);
4008       sqlite3BenignMallocHooks(xBenignBegin, xBenignEnd);
4009       break;
4010     }
4011 
4012     /*
4013     **  sqlite3_test_control(SQLITE_TESTCTRL_PENDING_BYTE, unsigned int X)
4014     **
4015     ** Set the PENDING byte to the value in the argument, if X>0.
4016     ** Make no changes if X==0.  Return the value of the pending byte
4017     ** as it existing before this routine was called.
4018     **
4019     ** IMPORTANT:  Changing the PENDING byte from 0x40000000 results in
4020     ** an incompatible database file format.  Changing the PENDING byte
4021     ** while any database connection is open results in undefined and
4022     ** deleterious behavior.
4023     */
4024     case SQLITE_TESTCTRL_PENDING_BYTE: {
4025       rc = PENDING_BYTE;
4026 #ifndef SQLITE_OMIT_WSD
4027       {
4028         unsigned int newVal = va_arg(ap, unsigned int);
4029         if( newVal ) sqlite3PendingByte = newVal;
4030       }
4031 #endif
4032       break;
4033     }
4034 
4035     /*
4036     **  sqlite3_test_control(SQLITE_TESTCTRL_ASSERT, int X)
4037     **
4038     ** This action provides a run-time test to see whether or not
4039     ** assert() was enabled at compile-time.  If X is true and assert()
4040     ** is enabled, then the return value is true.  If X is true and
4041     ** assert() is disabled, then the return value is zero.  If X is
4042     ** false and assert() is enabled, then the assertion fires and the
4043     ** process aborts.  If X is false and assert() is disabled, then the
4044     ** return value is zero.
4045     */
4046     case SQLITE_TESTCTRL_ASSERT: {
4047       volatile int x = 0;
4048       assert( /*side-effects-ok*/ (x = va_arg(ap,int))!=0 );
4049       rc = x;
4050       break;
4051     }
4052 
4053 
4054     /*
4055     **  sqlite3_test_control(SQLITE_TESTCTRL_ALWAYS, int X)
4056     **
4057     ** This action provides a run-time test to see how the ALWAYS and
4058     ** NEVER macros were defined at compile-time.
4059     **
4060     ** The return value is ALWAYS(X) if X is true, or 0 if X is false.
4061     **
4062     ** The recommended test is X==2.  If the return value is 2, that means
4063     ** ALWAYS() and NEVER() are both no-op pass-through macros, which is the
4064     ** default setting.  If the return value is 1, then ALWAYS() is either
4065     ** hard-coded to true or else it asserts if its argument is false.
4066     ** The first behavior (hard-coded to true) is the case if
4067     ** SQLITE_TESTCTRL_ASSERT shows that assert() is disabled and the second
4068     ** behavior (assert if the argument to ALWAYS() is false) is the case if
4069     ** SQLITE_TESTCTRL_ASSERT shows that assert() is enabled.
4070     **
4071     ** The run-time test procedure might look something like this:
4072     **
4073     **    if( sqlite3_test_control(SQLITE_TESTCTRL_ALWAYS, 2)==2 ){
4074     **      // ALWAYS() and NEVER() are no-op pass-through macros
4075     **    }else if( sqlite3_test_control(SQLITE_TESTCTRL_ASSERT, 1) ){
4076     **      // ALWAYS(x) asserts that x is true. NEVER(x) asserts x is false.
4077     **    }else{
4078     **      // ALWAYS(x) is a constant 1.  NEVER(x) is a constant 0.
4079     **    }
4080     */
4081     case SQLITE_TESTCTRL_ALWAYS: {
4082       int x = va_arg(ap,int);
4083       rc = x ? ALWAYS(x) : 0;
4084       break;
4085     }
4086 
4087     /*
4088     **   sqlite3_test_control(SQLITE_TESTCTRL_BYTEORDER);
4089     **
4090     ** The integer returned reveals the byte-order of the computer on which
4091     ** SQLite is running:
4092     **
4093     **       1     big-endian,    determined at run-time
4094     **      10     little-endian, determined at run-time
4095     **  432101     big-endian,    determined at compile-time
4096     **  123410     little-endian, determined at compile-time
4097     */
4098     case SQLITE_TESTCTRL_BYTEORDER: {
4099       rc = SQLITE_BYTEORDER*100 + SQLITE_LITTLEENDIAN*10 + SQLITE_BIGENDIAN;
4100       break;
4101     }
4102 
4103     /*  sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS, sqlite3 *db, int N)
4104     **
4105     ** Enable or disable various optimizations for testing purposes.  The
4106     ** argument N is a bitmask of optimizations to be disabled.  For normal
4107     ** operation N should be 0.  The idea is that a test program (like the
4108     ** SQL Logic Test or SLT test module) can run the same SQL multiple times
4109     ** with various optimizations disabled to verify that the same answer
4110     ** is obtained in every case.
4111     */
4112     case SQLITE_TESTCTRL_OPTIMIZATIONS: {
4113       sqlite3 *db = va_arg(ap, sqlite3*);
4114       db->dbOptFlags = va_arg(ap, u32);
4115       break;
4116     }
4117 
4118     /*   sqlite3_test_control(SQLITE_TESTCTRL_LOCALTIME_FAULT, int onoff);
4119     **
4120     ** If parameter onoff is non-zero, subsequent calls to localtime()
4121     ** and its variants fail. If onoff is zero, undo this setting.
4122     */
4123     case SQLITE_TESTCTRL_LOCALTIME_FAULT: {
4124       sqlite3GlobalConfig.bLocaltimeFault = va_arg(ap, int);
4125       break;
4126     }
4127 
4128     /*   sqlite3_test_control(SQLITE_TESTCTRL_INTERNAL_FUNCTIONS, sqlite3*);
4129     **
4130     ** Toggle the ability to use internal functions on or off for
4131     ** the database connection given in the argument.
4132     */
4133     case SQLITE_TESTCTRL_INTERNAL_FUNCTIONS: {
4134       sqlite3 *db = va_arg(ap, sqlite3*);
4135       db->mDbFlags ^= DBFLAG_InternalFunc;
4136       break;
4137     }
4138 
4139     /*   sqlite3_test_control(SQLITE_TESTCTRL_NEVER_CORRUPT, int);
4140     **
4141     ** Set or clear a flag that indicates that the database file is always well-
4142     ** formed and never corrupt.  This flag is clear by default, indicating that
4143     ** database files might have arbitrary corruption.  Setting the flag during
4144     ** testing causes certain assert() statements in the code to be activated
4145     ** that demonstrat invariants on well-formed database files.
4146     */
4147     case SQLITE_TESTCTRL_NEVER_CORRUPT: {
4148       sqlite3GlobalConfig.neverCorrupt = va_arg(ap, int);
4149       break;
4150     }
4151 
4152     /*   sqlite3_test_control(SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS, int);
4153     **
4154     ** Set or clear a flag that causes SQLite to verify that type, name,
4155     ** and tbl_name fields of the sqlite_schema table.  This is normally
4156     ** on, but it is sometimes useful to turn it off for testing.
4157     **
4158     ** 2020-07-22:  Disabling EXTRA_SCHEMA_CHECKS also disables the
4159     ** verification of rootpage numbers when parsing the schema.  This
4160     ** is useful to make it easier to reach strange internal error states
4161     ** during testing.  The EXTRA_SCHEMA_CHECKS setting is always enabled
4162     ** in production.
4163     */
4164     case SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS: {
4165       sqlite3GlobalConfig.bExtraSchemaChecks = va_arg(ap, int);
4166       break;
4167     }
4168 
4169     /* Set the threshold at which OP_Once counters reset back to zero.
4170     ** By default this is 0x7ffffffe (over 2 billion), but that value is
4171     ** too big to test in a reasonable amount of time, so this control is
4172     ** provided to set a small and easily reachable reset value.
4173     */
4174     case SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD: {
4175       sqlite3GlobalConfig.iOnceResetThreshold = va_arg(ap, int);
4176       break;
4177     }
4178 
4179     /*   sqlite3_test_control(SQLITE_TESTCTRL_VDBE_COVERAGE, xCallback, ptr);
4180     **
4181     ** Set the VDBE coverage callback function to xCallback with context
4182     ** pointer ptr.
4183     */
4184     case SQLITE_TESTCTRL_VDBE_COVERAGE: {
4185 #ifdef SQLITE_VDBE_COVERAGE
4186       typedef void (*branch_callback)(void*,unsigned int,
4187                                       unsigned char,unsigned char);
4188       sqlite3GlobalConfig.xVdbeBranch = va_arg(ap,branch_callback);
4189       sqlite3GlobalConfig.pVdbeBranchArg = va_arg(ap,void*);
4190 #endif
4191       break;
4192     }
4193 
4194     /*   sqlite3_test_control(SQLITE_TESTCTRL_SORTER_MMAP, db, nMax); */
4195     case SQLITE_TESTCTRL_SORTER_MMAP: {
4196       sqlite3 *db = va_arg(ap, sqlite3*);
4197       db->nMaxSorterMmap = va_arg(ap, int);
4198       break;
4199     }
4200 
4201     /*   sqlite3_test_control(SQLITE_TESTCTRL_ISINIT);
4202     **
4203     ** Return SQLITE_OK if SQLite has been initialized and SQLITE_ERROR if
4204     ** not.
4205     */
4206     case SQLITE_TESTCTRL_ISINIT: {
4207       if( sqlite3GlobalConfig.isInit==0 ) rc = SQLITE_ERROR;
4208       break;
4209     }
4210 
4211     /*  sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, db, dbName, onOff, tnum);
4212     **
4213     ** This test control is used to create imposter tables.  "db" is a pointer
4214     ** to the database connection.  dbName is the database name (ex: "main" or
4215     ** "temp") which will receive the imposter.  "onOff" turns imposter mode on
4216     ** or off.  "tnum" is the root page of the b-tree to which the imposter
4217     ** table should connect.
4218     **
4219     ** Enable imposter mode only when the schema has already been parsed.  Then
4220     ** run a single CREATE TABLE statement to construct the imposter table in
4221     ** the parsed schema.  Then turn imposter mode back off again.
4222     **
4223     ** If onOff==0 and tnum>0 then reset the schema for all databases, causing
4224     ** the schema to be reparsed the next time it is needed.  This has the
4225     ** effect of erasing all imposter tables.
4226     */
4227     case SQLITE_TESTCTRL_IMPOSTER: {
4228       sqlite3 *db = va_arg(ap, sqlite3*);
4229       sqlite3_mutex_enter(db->mutex);
4230       db->init.iDb = sqlite3FindDbName(db, va_arg(ap,const char*));
4231       db->init.busy = db->init.imposterTable = va_arg(ap,int);
4232       db->init.newTnum = va_arg(ap,int);
4233       if( db->init.busy==0 && db->init.newTnum>0 ){
4234         sqlite3ResetAllSchemasOfConnection(db);
4235       }
4236       sqlite3_mutex_leave(db->mutex);
4237       break;
4238     }
4239 
4240 #if defined(YYCOVERAGE)
4241     /*  sqlite3_test_control(SQLITE_TESTCTRL_PARSER_COVERAGE, FILE *out)
4242     **
4243     ** This test control (only available when SQLite is compiled with
4244     ** -DYYCOVERAGE) writes a report onto "out" that shows all
4245     ** state/lookahead combinations in the parser state machine
4246     ** which are never exercised.  If any state is missed, make the
4247     ** return code SQLITE_ERROR.
4248     */
4249     case SQLITE_TESTCTRL_PARSER_COVERAGE: {
4250       FILE *out = va_arg(ap, FILE*);
4251       if( sqlite3ParserCoverage(out) ) rc = SQLITE_ERROR;
4252       break;
4253     }
4254 #endif /* defined(YYCOVERAGE) */
4255 
4256     /*  sqlite3_test_control(SQLITE_TESTCTRL_RESULT_INTREAL, sqlite3_context*);
4257     **
4258     ** This test-control causes the most recent sqlite3_result_int64() value
4259     ** to be interpreted as a MEM_IntReal instead of as an MEM_Int.  Normally,
4260     ** MEM_IntReal values only arise during an INSERT operation of integer
4261     ** values into a REAL column, so they can be challenging to test.  This
4262     ** test-control enables us to write an intreal() SQL function that can
4263     ** inject an intreal() value at arbitrary places in an SQL statement,
4264     ** for testing purposes.
4265     */
4266     case SQLITE_TESTCTRL_RESULT_INTREAL: {
4267       sqlite3_context *pCtx = va_arg(ap, sqlite3_context*);
4268       sqlite3ResultIntReal(pCtx);
4269       break;
4270     }
4271 
4272     /*  sqlite3_test_control(SQLITE_TESTCTRL_SEEK_COUNT,
4273     **    sqlite3 *db,    // Database connection
4274     **    u64 *pnSeek     // Write seek count here
4275     **  );
4276     **
4277     ** This test-control queries the seek-counter on the "main" database
4278     ** file.  The seek-counter is written into *pnSeek and is then reset.
4279     ** The seek-count is only available if compiled with SQLITE_DEBUG.
4280     */
4281     case SQLITE_TESTCTRL_SEEK_COUNT: {
4282       sqlite3 *db = va_arg(ap, sqlite3*);
4283       u64 *pn = va_arg(ap, sqlite3_uint64*);
4284       *pn = sqlite3BtreeSeekCount(db->aDb->pBt);
4285       (void)db;  /* Silence harmless unused variable warning */
4286       break;
4287     }
4288 
4289     /*  sqlite3_test_control(SQLITE_TESTCTRL_TRACEFLAGS, op, ptr)
4290     **
4291     **  "ptr" is a pointer to a u32.
4292     **
4293     **   op==0       Store the current sqlite3SelectTrace in *ptr
4294     **   op==1       Set sqlite3SelectTrace to the value *ptr
4295     **   op==3       Store the current sqlite3WhereTrace in *ptr
4296     **   op==3       Set sqlite3WhereTrace to the value *ptr
4297     */
4298     case SQLITE_TESTCTRL_TRACEFLAGS: {
4299        int opTrace = va_arg(ap, int);
4300        u32 *ptr = va_arg(ap, u32*);
4301        switch( opTrace ){
4302          case 0:   *ptr = sqlite3SelectTrace;      break;
4303          case 1:   sqlite3SelectTrace = *ptr;      break;
4304          case 2:   *ptr = sqlite3WhereTrace;       break;
4305          case 3:   sqlite3WhereTrace = *ptr;       break;
4306        }
4307        break;
4308     }
4309 
4310 #if defined(SQLITE_DEBUG) && !defined(SQLITE_OMIT_WSD)
4311     /* sqlite3_test_control(SQLITE_TESTCTRL_TUNE, id, *piValue)
4312     **
4313     ** If "id" is an integer between 1 and SQLITE_NTUNE then set the value
4314     ** of the id-th tuning parameter to *piValue.  If "id" is between -1
4315     ** and -SQLITE_NTUNE, then write the current value of the (-id)-th
4316     ** tuning parameter into *piValue.
4317     **
4318     ** Tuning parameters are for use during transient development builds,
4319     ** to help find the best values for constants in the query planner.
4320     ** Access tuning parameters using the Tuning(ID) macro.  Set the
4321     ** parameters in the CLI using ".testctrl tune ID VALUE".
4322     **
4323     ** Transient use only.  Tuning parameters should not be used in
4324     ** checked-in code.
4325     */
4326     case SQLITE_TESTCTRL_TUNE: {
4327       int id = va_arg(ap, int);
4328       int *piValue = va_arg(ap, int*);
4329       if( id>0 && id<=SQLITE_NTUNE ){
4330         Tuning(id) = *piValue;
4331       }else if( id<0 && id>=-SQLITE_NTUNE ){
4332         *piValue = Tuning(-id);
4333       }else{
4334         rc = SQLITE_NOTFOUND;
4335       }
4336       break;
4337     }
4338 #endif
4339   }
4340   va_end(ap);
4341 #endif /* SQLITE_UNTESTABLE */
4342   return rc;
4343 }
4344 
4345 /*
4346 ** The Pager stores the Database filename, Journal filename, and WAL filename
4347 ** consecutively in memory, in that order.  The database filename is prefixed
4348 ** by four zero bytes.  Locate the start of the database filename by searching
4349 ** backwards for the first byte following four consecutive zero bytes.
4350 **
4351 ** This only works if the filename passed in was obtained from the Pager.
4352 */
4353 static const char *databaseName(const char *zName){
4354   while( zName[-1]!=0 || zName[-2]!=0 || zName[-3]!=0 || zName[-4]!=0 ){
4355     zName--;
4356   }
4357   return zName;
4358 }
4359 
4360 /*
4361 ** Append text z[] to the end of p[].  Return a pointer to the first
4362 ** character after then zero terminator on the new text in p[].
4363 */
4364 static char *appendText(char *p, const char *z){
4365   size_t n = strlen(z);
4366   memcpy(p, z, n+1);
4367   return p+n+1;
4368 }
4369 
4370 /*
4371 ** Allocate memory to hold names for a database, journal file, WAL file,
4372 ** and query parameters.  The pointer returned is valid for use by
4373 ** sqlite3_filename_database() and sqlite3_uri_parameter() and related
4374 ** functions.
4375 **
4376 ** Memory layout must be compatible with that generated by the pager
4377 ** and expected by sqlite3_uri_parameter() and databaseName().
4378 */
4379 char *sqlite3_create_filename(
4380   const char *zDatabase,
4381   const char *zJournal,
4382   const char *zWal,
4383   int nParam,
4384   const char **azParam
4385 ){
4386   sqlite3_int64 nByte;
4387   int i;
4388   char *pResult, *p;
4389   nByte = strlen(zDatabase) + strlen(zJournal) + strlen(zWal) + 10;
4390   for(i=0; i<nParam*2; i++){
4391     nByte += strlen(azParam[i])+1;
4392   }
4393   pResult = p = sqlite3_malloc64( nByte );
4394   if( p==0 ) return 0;
4395   memset(p, 0, 4);
4396   p += 4;
4397   p = appendText(p, zDatabase);
4398   for(i=0; i<nParam*2; i++){
4399     p = appendText(p, azParam[i]);
4400   }
4401   *(p++) = 0;
4402   p = appendText(p, zJournal);
4403   p = appendText(p, zWal);
4404   *(p++) = 0;
4405   *(p++) = 0;
4406   assert( (sqlite3_int64)(p - pResult)==nByte );
4407   return pResult + 4;
4408 }
4409 
4410 /*
4411 ** Free memory obtained from sqlite3_create_filename().  It is a severe
4412 ** error to call this routine with any parameter other than a pointer
4413 ** previously obtained from sqlite3_create_filename() or a NULL pointer.
4414 */
4415 void sqlite3_free_filename(char *p){
4416   if( p==0 ) return;
4417   p = (char*)databaseName(p);
4418   sqlite3_free(p - 4);
4419 }
4420 
4421 
4422 /*
4423 ** This is a utility routine, useful to VFS implementations, that checks
4424 ** to see if a database file was a URI that contained a specific query
4425 ** parameter, and if so obtains the value of the query parameter.
4426 **
4427 ** The zFilename argument is the filename pointer passed into the xOpen()
4428 ** method of a VFS implementation.  The zParam argument is the name of the
4429 ** query parameter we seek.  This routine returns the value of the zParam
4430 ** parameter if it exists.  If the parameter does not exist, this routine
4431 ** returns a NULL pointer.
4432 */
4433 const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam){
4434   if( zFilename==0 || zParam==0 ) return 0;
4435   zFilename = databaseName(zFilename);
4436   return uriParameter(zFilename, zParam);
4437 }
4438 
4439 /*
4440 ** Return a pointer to the name of Nth query parameter of the filename.
4441 */
4442 const char *sqlite3_uri_key(const char *zFilename, int N){
4443   if( zFilename==0 || N<0 ) return 0;
4444   zFilename = databaseName(zFilename);
4445   zFilename += sqlite3Strlen30(zFilename) + 1;
4446   while( ALWAYS(zFilename) && zFilename[0] && (N--)>0 ){
4447     zFilename += sqlite3Strlen30(zFilename) + 1;
4448     zFilename += sqlite3Strlen30(zFilename) + 1;
4449   }
4450   return zFilename[0] ? zFilename : 0;
4451 }
4452 
4453 /*
4454 ** Return a boolean value for a query parameter.
4455 */
4456 int sqlite3_uri_boolean(const char *zFilename, const char *zParam, int bDflt){
4457   const char *z = sqlite3_uri_parameter(zFilename, zParam);
4458   bDflt = bDflt!=0;
4459   return z ? sqlite3GetBoolean(z, bDflt) : bDflt;
4460 }
4461 
4462 /*
4463 ** Return a 64-bit integer value for a query parameter.
4464 */
4465 sqlite3_int64 sqlite3_uri_int64(
4466   const char *zFilename,    /* Filename as passed to xOpen */
4467   const char *zParam,       /* URI parameter sought */
4468   sqlite3_int64 bDflt       /* return if parameter is missing */
4469 ){
4470   const char *z = sqlite3_uri_parameter(zFilename, zParam);
4471   sqlite3_int64 v;
4472   if( z && sqlite3DecOrHexToI64(z, &v)==0 ){
4473     bDflt = v;
4474   }
4475   return bDflt;
4476 }
4477 
4478 /*
4479 ** Translate a filename that was handed to a VFS routine into the corresponding
4480 ** database, journal, or WAL file.
4481 **
4482 ** It is an error to pass this routine a filename string that was not
4483 ** passed into the VFS from the SQLite core.  Doing so is similar to
4484 ** passing free() a pointer that was not obtained from malloc() - it is
4485 ** an error that we cannot easily detect but that will likely cause memory
4486 ** corruption.
4487 */
4488 const char *sqlite3_filename_database(const char *zFilename){
4489   if( zFilename==0 ) return 0;
4490   return databaseName(zFilename);
4491 }
4492 const char *sqlite3_filename_journal(const char *zFilename){
4493   if( zFilename==0 ) return 0;
4494   zFilename = databaseName(zFilename);
4495   zFilename += sqlite3Strlen30(zFilename) + 1;
4496   while( ALWAYS(zFilename) && zFilename[0] ){
4497     zFilename += sqlite3Strlen30(zFilename) + 1;
4498     zFilename += sqlite3Strlen30(zFilename) + 1;
4499   }
4500   return zFilename + 1;
4501 }
4502 const char *sqlite3_filename_wal(const char *zFilename){
4503 #ifdef SQLITE_OMIT_WAL
4504   return 0;
4505 #else
4506   zFilename = sqlite3_filename_journal(zFilename);
4507   if( zFilename ) zFilename += sqlite3Strlen30(zFilename) + 1;
4508   return zFilename;
4509 #endif
4510 }
4511 
4512 /*
4513 ** Return the Btree pointer identified by zDbName.  Return NULL if not found.
4514 */
4515 Btree *sqlite3DbNameToBtree(sqlite3 *db, const char *zDbName){
4516   int iDb = zDbName ? sqlite3FindDbName(db, zDbName) : 0;
4517   return iDb<0 ? 0 : db->aDb[iDb].pBt;
4518 }
4519 
4520 /*
4521 ** Return the filename of the database associated with a database
4522 ** connection.
4523 */
4524 const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName){
4525   Btree *pBt;
4526 #ifdef SQLITE_ENABLE_API_ARMOR
4527   if( !sqlite3SafetyCheckOk(db) ){
4528     (void)SQLITE_MISUSE_BKPT;
4529     return 0;
4530   }
4531 #endif
4532   pBt = sqlite3DbNameToBtree(db, zDbName);
4533   return pBt ? sqlite3BtreeGetFilename(pBt) : 0;
4534 }
4535 
4536 /*
4537 ** Return 1 if database is read-only or 0 if read/write.  Return -1 if
4538 ** no such database exists.
4539 */
4540 int sqlite3_db_readonly(sqlite3 *db, const char *zDbName){
4541   Btree *pBt;
4542 #ifdef SQLITE_ENABLE_API_ARMOR
4543   if( !sqlite3SafetyCheckOk(db) ){
4544     (void)SQLITE_MISUSE_BKPT;
4545     return -1;
4546   }
4547 #endif
4548   pBt = sqlite3DbNameToBtree(db, zDbName);
4549   return pBt ? sqlite3BtreeIsReadonly(pBt) : -1;
4550 }
4551 
4552 #ifdef SQLITE_ENABLE_SNAPSHOT
4553 /*
4554 ** Obtain a snapshot handle for the snapshot of database zDb currently
4555 ** being read by handle db.
4556 */
4557 int sqlite3_snapshot_get(
4558   sqlite3 *db,
4559   const char *zDb,
4560   sqlite3_snapshot **ppSnapshot
4561 ){
4562   int rc = SQLITE_ERROR;
4563 #ifndef SQLITE_OMIT_WAL
4564 
4565 #ifdef SQLITE_ENABLE_API_ARMOR
4566   if( !sqlite3SafetyCheckOk(db) ){
4567     return SQLITE_MISUSE_BKPT;
4568   }
4569 #endif
4570   sqlite3_mutex_enter(db->mutex);
4571 
4572   if( db->autoCommit==0 ){
4573     int iDb = sqlite3FindDbName(db, zDb);
4574     if( iDb==0 || iDb>1 ){
4575       Btree *pBt = db->aDb[iDb].pBt;
4576       if( SQLITE_TXN_WRITE!=sqlite3BtreeTxnState(pBt) ){
4577         rc = sqlite3BtreeBeginTrans(pBt, 0, 0);
4578         if( rc==SQLITE_OK ){
4579           rc = sqlite3PagerSnapshotGet(sqlite3BtreePager(pBt), ppSnapshot);
4580         }
4581       }
4582     }
4583   }
4584 
4585   sqlite3_mutex_leave(db->mutex);
4586 #endif   /* SQLITE_OMIT_WAL */
4587   return rc;
4588 }
4589 
4590 /*
4591 ** Open a read-transaction on the snapshot idendified by pSnapshot.
4592 */
4593 int sqlite3_snapshot_open(
4594   sqlite3 *db,
4595   const char *zDb,
4596   sqlite3_snapshot *pSnapshot
4597 ){
4598   int rc = SQLITE_ERROR;
4599 #ifndef SQLITE_OMIT_WAL
4600 
4601 #ifdef SQLITE_ENABLE_API_ARMOR
4602   if( !sqlite3SafetyCheckOk(db) ){
4603     return SQLITE_MISUSE_BKPT;
4604   }
4605 #endif
4606   sqlite3_mutex_enter(db->mutex);
4607   if( db->autoCommit==0 ){
4608     int iDb;
4609     iDb = sqlite3FindDbName(db, zDb);
4610     if( iDb==0 || iDb>1 ){
4611       Btree *pBt = db->aDb[iDb].pBt;
4612       if( sqlite3BtreeTxnState(pBt)!=SQLITE_TXN_WRITE ){
4613         Pager *pPager = sqlite3BtreePager(pBt);
4614         int bUnlock = 0;
4615         if( sqlite3BtreeTxnState(pBt)!=SQLITE_TXN_NONE ){
4616           if( db->nVdbeActive==0 ){
4617             rc = sqlite3PagerSnapshotCheck(pPager, pSnapshot);
4618             if( rc==SQLITE_OK ){
4619               bUnlock = 1;
4620               rc = sqlite3BtreeCommit(pBt);
4621             }
4622           }
4623         }else{
4624           rc = SQLITE_OK;
4625         }
4626         if( rc==SQLITE_OK ){
4627           rc = sqlite3PagerSnapshotOpen(pPager, pSnapshot);
4628         }
4629         if( rc==SQLITE_OK ){
4630           rc = sqlite3BtreeBeginTrans(pBt, 0, 0);
4631           sqlite3PagerSnapshotOpen(pPager, 0);
4632         }
4633         if( bUnlock ){
4634           sqlite3PagerSnapshotUnlock(pPager);
4635         }
4636       }
4637     }
4638   }
4639 
4640   sqlite3_mutex_leave(db->mutex);
4641 #endif   /* SQLITE_OMIT_WAL */
4642   return rc;
4643 }
4644 
4645 /*
4646 ** Recover as many snapshots as possible from the wal file associated with
4647 ** schema zDb of database db.
4648 */
4649 int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb){
4650   int rc = SQLITE_ERROR;
4651   int iDb;
4652 #ifndef SQLITE_OMIT_WAL
4653 
4654 #ifdef SQLITE_ENABLE_API_ARMOR
4655   if( !sqlite3SafetyCheckOk(db) ){
4656     return SQLITE_MISUSE_BKPT;
4657   }
4658 #endif
4659 
4660   sqlite3_mutex_enter(db->mutex);
4661   iDb = sqlite3FindDbName(db, zDb);
4662   if( iDb==0 || iDb>1 ){
4663     Btree *pBt = db->aDb[iDb].pBt;
4664     if( SQLITE_TXN_NONE==sqlite3BtreeTxnState(pBt) ){
4665       rc = sqlite3BtreeBeginTrans(pBt, 0, 0);
4666       if( rc==SQLITE_OK ){
4667         rc = sqlite3PagerSnapshotRecover(sqlite3BtreePager(pBt));
4668         sqlite3BtreeCommit(pBt);
4669       }
4670     }
4671   }
4672   sqlite3_mutex_leave(db->mutex);
4673 #endif   /* SQLITE_OMIT_WAL */
4674   return rc;
4675 }
4676 
4677 /*
4678 ** Free a snapshot handle obtained from sqlite3_snapshot_get().
4679 */
4680 void sqlite3_snapshot_free(sqlite3_snapshot *pSnapshot){
4681   sqlite3_free(pSnapshot);
4682 }
4683 #endif /* SQLITE_ENABLE_SNAPSHOT */
4684 
4685 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
4686 /*
4687 ** Given the name of a compile-time option, return true if that option
4688 ** was used and false if not.
4689 **
4690 ** The name can optionally begin with "SQLITE_" but the "SQLITE_" prefix
4691 ** is not required for a match.
4692 */
4693 int sqlite3_compileoption_used(const char *zOptName){
4694   int i, n;
4695   int nOpt;
4696   const char **azCompileOpt;
4697 
4698 #if SQLITE_ENABLE_API_ARMOR
4699   if( zOptName==0 ){
4700     (void)SQLITE_MISUSE_BKPT;
4701     return 0;
4702   }
4703 #endif
4704 
4705   azCompileOpt = sqlite3CompileOptions(&nOpt);
4706 
4707   if( sqlite3StrNICmp(zOptName, "SQLITE_", 7)==0 ) zOptName += 7;
4708   n = sqlite3Strlen30(zOptName);
4709 
4710   /* Since nOpt is normally in single digits, a linear search is
4711   ** adequate. No need for a binary search. */
4712   for(i=0; i<nOpt; i++){
4713     if( sqlite3StrNICmp(zOptName, azCompileOpt[i], n)==0
4714      && sqlite3IsIdChar((unsigned char)azCompileOpt[i][n])==0
4715     ){
4716       return 1;
4717     }
4718   }
4719   return 0;
4720 }
4721 
4722 /*
4723 ** Return the N-th compile-time option string.  If N is out of range,
4724 ** return a NULL pointer.
4725 */
4726 const char *sqlite3_compileoption_get(int N){
4727   int nOpt;
4728   const char **azCompileOpt;
4729   azCompileOpt = sqlite3CompileOptions(&nOpt);
4730   if( N>=0 && N<nOpt ){
4731     return azCompileOpt[N];
4732   }
4733   return 0;
4734 }
4735 #endif /* SQLITE_OMIT_COMPILEOPTION_DIAGS */
4736