xref: /sqlite-3.40.0/src/main.c (revision dee0359d)
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;
1142   assert( (p->funcFlags & SQLITE_FUNC_BUILTIN)==0 );
1143   pDestructor = p->u.pDestructor;
1144   if( pDestructor ){
1145     pDestructor->nRef--;
1146     if( pDestructor->nRef==0 ){
1147       pDestructor->xDestroy(pDestructor->pUserData);
1148       sqlite3DbFree(db, pDestructor);
1149     }
1150   }
1151 }
1152 
1153 /*
1154 ** Disconnect all sqlite3_vtab objects that belong to database connection
1155 ** db. This is called when db is being closed.
1156 */
1157 static void disconnectAllVtab(sqlite3 *db){
1158 #ifndef SQLITE_OMIT_VIRTUALTABLE
1159   int i;
1160   HashElem *p;
1161   sqlite3BtreeEnterAll(db);
1162   for(i=0; i<db->nDb; i++){
1163     Schema *pSchema = db->aDb[i].pSchema;
1164     if( pSchema ){
1165       for(p=sqliteHashFirst(&pSchema->tblHash); p; p=sqliteHashNext(p)){
1166         Table *pTab = (Table *)sqliteHashData(p);
1167         if( IsVirtual(pTab) ) sqlite3VtabDisconnect(db, pTab);
1168       }
1169     }
1170   }
1171   for(p=sqliteHashFirst(&db->aModule); p; p=sqliteHashNext(p)){
1172     Module *pMod = (Module *)sqliteHashData(p);
1173     if( pMod->pEpoTab ){
1174       sqlite3VtabDisconnect(db, pMod->pEpoTab);
1175     }
1176   }
1177   sqlite3VtabUnlockList(db);
1178   sqlite3BtreeLeaveAll(db);
1179 #else
1180   UNUSED_PARAMETER(db);
1181 #endif
1182 }
1183 
1184 /*
1185 ** Return TRUE if database connection db has unfinalized prepared
1186 ** statements or unfinished sqlite3_backup objects.
1187 */
1188 static int connectionIsBusy(sqlite3 *db){
1189   int j;
1190   assert( sqlite3_mutex_held(db->mutex) );
1191   if( db->pVdbe ) return 1;
1192   for(j=0; j<db->nDb; j++){
1193     Btree *pBt = db->aDb[j].pBt;
1194     if( pBt && sqlite3BtreeIsInBackup(pBt) ) return 1;
1195   }
1196   return 0;
1197 }
1198 
1199 /*
1200 ** Close an existing SQLite database
1201 */
1202 static int sqlite3Close(sqlite3 *db, int forceZombie){
1203   if( !db ){
1204     /* EVIDENCE-OF: R-63257-11740 Calling sqlite3_close() or
1205     ** sqlite3_close_v2() with a NULL pointer argument is a harmless no-op. */
1206     return SQLITE_OK;
1207   }
1208   if( !sqlite3SafetyCheckSickOrOk(db) ){
1209     return SQLITE_MISUSE_BKPT;
1210   }
1211   sqlite3_mutex_enter(db->mutex);
1212   if( db->mTrace & SQLITE_TRACE_CLOSE ){
1213     db->trace.xV2(SQLITE_TRACE_CLOSE, db->pTraceArg, db, 0);
1214   }
1215 
1216   /* Force xDisconnect calls on all virtual tables */
1217   disconnectAllVtab(db);
1218 
1219   /* If a transaction is open, the disconnectAllVtab() call above
1220   ** will not have called the xDisconnect() method on any virtual
1221   ** tables in the db->aVTrans[] array. The following sqlite3VtabRollback()
1222   ** call will do so. We need to do this before the check for active
1223   ** SQL statements below, as the v-table implementation may be storing
1224   ** some prepared statements internally.
1225   */
1226   sqlite3VtabRollback(db);
1227 
1228   /* Legacy behavior (sqlite3_close() behavior) is to return
1229   ** SQLITE_BUSY if the connection can not be closed immediately.
1230   */
1231   if( !forceZombie && connectionIsBusy(db) ){
1232     sqlite3ErrorWithMsg(db, SQLITE_BUSY, "unable to close due to unfinalized "
1233        "statements or unfinished backups");
1234     sqlite3_mutex_leave(db->mutex);
1235     return SQLITE_BUSY;
1236   }
1237 
1238 #ifdef SQLITE_ENABLE_SQLLOG
1239   if( sqlite3GlobalConfig.xSqllog ){
1240     /* Closing the handle. Fourth parameter is passed the value 2. */
1241     sqlite3GlobalConfig.xSqllog(sqlite3GlobalConfig.pSqllogArg, db, 0, 2);
1242   }
1243 #endif
1244 
1245   /* Convert the connection into a zombie and then close it.
1246   */
1247   db->eOpenState = SQLITE_STATE_ZOMBIE;
1248   sqlite3LeaveMutexAndCloseZombie(db);
1249   return SQLITE_OK;
1250 }
1251 
1252 /*
1253 ** Return the transaction state for a single databse, or the maximum
1254 ** transaction state over all attached databases if zSchema is null.
1255 */
1256 int sqlite3_txn_state(sqlite3 *db, const char *zSchema){
1257   int iDb, nDb;
1258   int iTxn = -1;
1259 #ifdef SQLITE_ENABLE_API_ARMOR
1260   if( !sqlite3SafetyCheckOk(db) ){
1261     (void)SQLITE_MISUSE_BKPT;
1262     return -1;
1263   }
1264 #endif
1265   sqlite3_mutex_enter(db->mutex);
1266   if( zSchema ){
1267     nDb = iDb = sqlite3FindDbName(db, zSchema);
1268     if( iDb<0 ) nDb--;
1269   }else{
1270     iDb = 0;
1271     nDb = db->nDb-1;
1272   }
1273   for(; iDb<=nDb; iDb++){
1274     Btree *pBt = db->aDb[iDb].pBt;
1275     int x = pBt!=0 ? sqlite3BtreeTxnState(pBt) : SQLITE_TXN_NONE;
1276     if( x>iTxn ) iTxn = x;
1277   }
1278   sqlite3_mutex_leave(db->mutex);
1279   return iTxn;
1280 }
1281 
1282 /*
1283 ** Two variations on the public interface for closing a database
1284 ** connection. The sqlite3_close() version returns SQLITE_BUSY and
1285 ** leaves the connection open if there are unfinalized prepared
1286 ** statements or unfinished sqlite3_backups.  The sqlite3_close_v2()
1287 ** version forces the connection to become a zombie if there are
1288 ** unclosed resources, and arranges for deallocation when the last
1289 ** prepare statement or sqlite3_backup closes.
1290 */
1291 int sqlite3_close(sqlite3 *db){ return sqlite3Close(db,0); }
1292 int sqlite3_close_v2(sqlite3 *db){ return sqlite3Close(db,1); }
1293 
1294 
1295 /*
1296 ** Close the mutex on database connection db.
1297 **
1298 ** Furthermore, if database connection db is a zombie (meaning that there
1299 ** has been a prior call to sqlite3_close(db) or sqlite3_close_v2(db)) and
1300 ** every sqlite3_stmt has now been finalized and every sqlite3_backup has
1301 ** finished, then free all resources.
1302 */
1303 void sqlite3LeaveMutexAndCloseZombie(sqlite3 *db){
1304   HashElem *i;                    /* Hash table iterator */
1305   int j;
1306 
1307   /* If there are outstanding sqlite3_stmt or sqlite3_backup objects
1308   ** or if the connection has not yet been closed by sqlite3_close_v2(),
1309   ** then just leave the mutex and return.
1310   */
1311   if( db->eOpenState!=SQLITE_STATE_ZOMBIE || connectionIsBusy(db) ){
1312     sqlite3_mutex_leave(db->mutex);
1313     return;
1314   }
1315 
1316   /* If we reach this point, it means that the database connection has
1317   ** closed all sqlite3_stmt and sqlite3_backup objects and has been
1318   ** passed to sqlite3_close (meaning that it is a zombie).  Therefore,
1319   ** go ahead and free all resources.
1320   */
1321 
1322   /* If a transaction is open, roll it back. This also ensures that if
1323   ** any database schemas have been modified by an uncommitted transaction
1324   ** they are reset. And that the required b-tree mutex is held to make
1325   ** the pager rollback and schema reset an atomic operation. */
1326   sqlite3RollbackAll(db, SQLITE_OK);
1327 
1328   /* Free any outstanding Savepoint structures. */
1329   sqlite3CloseSavepoints(db);
1330 
1331   /* Close all database connections */
1332   for(j=0; j<db->nDb; j++){
1333     struct Db *pDb = &db->aDb[j];
1334     if( pDb->pBt ){
1335       sqlite3BtreeClose(pDb->pBt);
1336       pDb->pBt = 0;
1337       if( j!=1 ){
1338         pDb->pSchema = 0;
1339       }
1340     }
1341   }
1342   /* Clear the TEMP schema separately and last */
1343   if( db->aDb[1].pSchema ){
1344     sqlite3SchemaClear(db->aDb[1].pSchema);
1345   }
1346   sqlite3VtabUnlockList(db);
1347 
1348   /* Free up the array of auxiliary databases */
1349   sqlite3CollapseDatabaseArray(db);
1350   assert( db->nDb<=2 );
1351   assert( db->aDb==db->aDbStatic );
1352 
1353   /* Tell the code in notify.c that the connection no longer holds any
1354   ** locks and does not require any further unlock-notify callbacks.
1355   */
1356   sqlite3ConnectionClosed(db);
1357 
1358   for(i=sqliteHashFirst(&db->aFunc); i; i=sqliteHashNext(i)){
1359     FuncDef *pNext, *p;
1360     p = sqliteHashData(i);
1361     do{
1362       functionDestroy(db, p);
1363       pNext = p->pNext;
1364       sqlite3DbFree(db, p);
1365       p = pNext;
1366     }while( p );
1367   }
1368   sqlite3HashClear(&db->aFunc);
1369   for(i=sqliteHashFirst(&db->aCollSeq); i; i=sqliteHashNext(i)){
1370     CollSeq *pColl = (CollSeq *)sqliteHashData(i);
1371     /* Invoke any destructors registered for collation sequence user data. */
1372     for(j=0; j<3; j++){
1373       if( pColl[j].xDel ){
1374         pColl[j].xDel(pColl[j].pUser);
1375       }
1376     }
1377     sqlite3DbFree(db, pColl);
1378   }
1379   sqlite3HashClear(&db->aCollSeq);
1380 #ifndef SQLITE_OMIT_VIRTUALTABLE
1381   for(i=sqliteHashFirst(&db->aModule); i; i=sqliteHashNext(i)){
1382     Module *pMod = (Module *)sqliteHashData(i);
1383     sqlite3VtabEponymousTableClear(db, pMod);
1384     sqlite3VtabModuleUnref(db, pMod);
1385   }
1386   sqlite3HashClear(&db->aModule);
1387 #endif
1388 
1389   sqlite3Error(db, SQLITE_OK); /* Deallocates any cached error strings. */
1390   sqlite3ValueFree(db->pErr);
1391   sqlite3CloseExtensions(db);
1392 #if SQLITE_USER_AUTHENTICATION
1393   sqlite3_free(db->auth.zAuthUser);
1394   sqlite3_free(db->auth.zAuthPW);
1395 #endif
1396 
1397   db->eOpenState = SQLITE_STATE_ERROR;
1398 
1399   /* The temp-database schema is allocated differently from the other schema
1400   ** objects (using sqliteMalloc() directly, instead of sqlite3BtreeSchema()).
1401   ** So it needs to be freed here. Todo: Why not roll the temp schema into
1402   ** the same sqliteMalloc() as the one that allocates the database
1403   ** structure?
1404   */
1405   sqlite3DbFree(db, db->aDb[1].pSchema);
1406   sqlite3_mutex_leave(db->mutex);
1407   db->eOpenState = SQLITE_STATE_CLOSED;
1408   sqlite3_mutex_free(db->mutex);
1409   assert( sqlite3LookasideUsed(db,0)==0 );
1410   if( db->lookaside.bMalloced ){
1411     sqlite3_free(db->lookaside.pStart);
1412   }
1413   sqlite3_free(db);
1414 }
1415 
1416 /*
1417 ** Rollback all database files.  If tripCode is not SQLITE_OK, then
1418 ** any write cursors are invalidated ("tripped" - as in "tripping a circuit
1419 ** breaker") and made to return tripCode if there are any further
1420 ** attempts to use that cursor.  Read cursors remain open and valid
1421 ** but are "saved" in case the table pages are moved around.
1422 */
1423 void sqlite3RollbackAll(sqlite3 *db, int tripCode){
1424   int i;
1425   int inTrans = 0;
1426   int schemaChange;
1427   assert( sqlite3_mutex_held(db->mutex) );
1428   sqlite3BeginBenignMalloc();
1429 
1430   /* Obtain all b-tree mutexes before making any calls to BtreeRollback().
1431   ** This is important in case the transaction being rolled back has
1432   ** modified the database schema. If the b-tree mutexes are not taken
1433   ** here, then another shared-cache connection might sneak in between
1434   ** the database rollback and schema reset, which can cause false
1435   ** corruption reports in some cases.  */
1436   sqlite3BtreeEnterAll(db);
1437   schemaChange = (db->mDbFlags & DBFLAG_SchemaChange)!=0 && db->init.busy==0;
1438 
1439   for(i=0; i<db->nDb; i++){
1440     Btree *p = db->aDb[i].pBt;
1441     if( p ){
1442       if( sqlite3BtreeTxnState(p)==SQLITE_TXN_WRITE ){
1443         inTrans = 1;
1444       }
1445       sqlite3BtreeRollback(p, tripCode, !schemaChange);
1446     }
1447   }
1448   sqlite3VtabRollback(db);
1449   sqlite3EndBenignMalloc();
1450 
1451   if( schemaChange ){
1452     sqlite3ExpirePreparedStatements(db, 0);
1453     sqlite3ResetAllSchemasOfConnection(db);
1454   }
1455   sqlite3BtreeLeaveAll(db);
1456 
1457   /* Any deferred constraint violations have now been resolved. */
1458   db->nDeferredCons = 0;
1459   db->nDeferredImmCons = 0;
1460   db->flags &= ~(u64)SQLITE_DeferFKs;
1461 
1462   /* If one has been configured, invoke the rollback-hook callback */
1463   if( db->xRollbackCallback && (inTrans || !db->autoCommit) ){
1464     db->xRollbackCallback(db->pRollbackArg);
1465   }
1466 }
1467 
1468 /*
1469 ** Return a static string containing the name corresponding to the error code
1470 ** specified in the argument.
1471 */
1472 #if defined(SQLITE_NEED_ERR_NAME)
1473 const char *sqlite3ErrName(int rc){
1474   const char *zName = 0;
1475   int i, origRc = rc;
1476   for(i=0; i<2 && zName==0; i++, rc &= 0xff){
1477     switch( rc ){
1478       case SQLITE_OK:                 zName = "SQLITE_OK";                break;
1479       case SQLITE_ERROR:              zName = "SQLITE_ERROR";             break;
1480       case SQLITE_ERROR_SNAPSHOT:     zName = "SQLITE_ERROR_SNAPSHOT";    break;
1481       case SQLITE_INTERNAL:           zName = "SQLITE_INTERNAL";          break;
1482       case SQLITE_PERM:               zName = "SQLITE_PERM";              break;
1483       case SQLITE_ABORT:              zName = "SQLITE_ABORT";             break;
1484       case SQLITE_ABORT_ROLLBACK:     zName = "SQLITE_ABORT_ROLLBACK";    break;
1485       case SQLITE_BUSY:               zName = "SQLITE_BUSY";              break;
1486       case SQLITE_BUSY_RECOVERY:      zName = "SQLITE_BUSY_RECOVERY";     break;
1487       case SQLITE_BUSY_SNAPSHOT:      zName = "SQLITE_BUSY_SNAPSHOT";     break;
1488       case SQLITE_LOCKED:             zName = "SQLITE_LOCKED";            break;
1489       case SQLITE_LOCKED_SHAREDCACHE: zName = "SQLITE_LOCKED_SHAREDCACHE";break;
1490       case SQLITE_NOMEM:              zName = "SQLITE_NOMEM";             break;
1491       case SQLITE_READONLY:           zName = "SQLITE_READONLY";          break;
1492       case SQLITE_READONLY_RECOVERY:  zName = "SQLITE_READONLY_RECOVERY"; break;
1493       case SQLITE_READONLY_CANTINIT:  zName = "SQLITE_READONLY_CANTINIT"; break;
1494       case SQLITE_READONLY_ROLLBACK:  zName = "SQLITE_READONLY_ROLLBACK"; break;
1495       case SQLITE_READONLY_DBMOVED:   zName = "SQLITE_READONLY_DBMOVED";  break;
1496       case SQLITE_READONLY_DIRECTORY: zName = "SQLITE_READONLY_DIRECTORY";break;
1497       case SQLITE_INTERRUPT:          zName = "SQLITE_INTERRUPT";         break;
1498       case SQLITE_IOERR:              zName = "SQLITE_IOERR";             break;
1499       case SQLITE_IOERR_READ:         zName = "SQLITE_IOERR_READ";        break;
1500       case SQLITE_IOERR_SHORT_READ:   zName = "SQLITE_IOERR_SHORT_READ";  break;
1501       case SQLITE_IOERR_WRITE:        zName = "SQLITE_IOERR_WRITE";       break;
1502       case SQLITE_IOERR_FSYNC:        zName = "SQLITE_IOERR_FSYNC";       break;
1503       case SQLITE_IOERR_DIR_FSYNC:    zName = "SQLITE_IOERR_DIR_FSYNC";   break;
1504       case SQLITE_IOERR_TRUNCATE:     zName = "SQLITE_IOERR_TRUNCATE";    break;
1505       case SQLITE_IOERR_FSTAT:        zName = "SQLITE_IOERR_FSTAT";       break;
1506       case SQLITE_IOERR_UNLOCK:       zName = "SQLITE_IOERR_UNLOCK";      break;
1507       case SQLITE_IOERR_RDLOCK:       zName = "SQLITE_IOERR_RDLOCK";      break;
1508       case SQLITE_IOERR_DELETE:       zName = "SQLITE_IOERR_DELETE";      break;
1509       case SQLITE_IOERR_NOMEM:        zName = "SQLITE_IOERR_NOMEM";       break;
1510       case SQLITE_IOERR_ACCESS:       zName = "SQLITE_IOERR_ACCESS";      break;
1511       case SQLITE_IOERR_CHECKRESERVEDLOCK:
1512                                 zName = "SQLITE_IOERR_CHECKRESERVEDLOCK"; break;
1513       case SQLITE_IOERR_LOCK:         zName = "SQLITE_IOERR_LOCK";        break;
1514       case SQLITE_IOERR_CLOSE:        zName = "SQLITE_IOERR_CLOSE";       break;
1515       case SQLITE_IOERR_DIR_CLOSE:    zName = "SQLITE_IOERR_DIR_CLOSE";   break;
1516       case SQLITE_IOERR_SHMOPEN:      zName = "SQLITE_IOERR_SHMOPEN";     break;
1517       case SQLITE_IOERR_SHMSIZE:      zName = "SQLITE_IOERR_SHMSIZE";     break;
1518       case SQLITE_IOERR_SHMLOCK:      zName = "SQLITE_IOERR_SHMLOCK";     break;
1519       case SQLITE_IOERR_SHMMAP:       zName = "SQLITE_IOERR_SHMMAP";      break;
1520       case SQLITE_IOERR_SEEK:         zName = "SQLITE_IOERR_SEEK";        break;
1521       case SQLITE_IOERR_DELETE_NOENT: zName = "SQLITE_IOERR_DELETE_NOENT";break;
1522       case SQLITE_IOERR_MMAP:         zName = "SQLITE_IOERR_MMAP";        break;
1523       case SQLITE_IOERR_GETTEMPPATH:  zName = "SQLITE_IOERR_GETTEMPPATH"; break;
1524       case SQLITE_IOERR_CONVPATH:     zName = "SQLITE_IOERR_CONVPATH";    break;
1525       case SQLITE_CORRUPT:            zName = "SQLITE_CORRUPT";           break;
1526       case SQLITE_CORRUPT_VTAB:       zName = "SQLITE_CORRUPT_VTAB";      break;
1527       case SQLITE_NOTFOUND:           zName = "SQLITE_NOTFOUND";          break;
1528       case SQLITE_FULL:               zName = "SQLITE_FULL";              break;
1529       case SQLITE_CANTOPEN:           zName = "SQLITE_CANTOPEN";          break;
1530       case SQLITE_CANTOPEN_NOTEMPDIR: zName = "SQLITE_CANTOPEN_NOTEMPDIR";break;
1531       case SQLITE_CANTOPEN_ISDIR:     zName = "SQLITE_CANTOPEN_ISDIR";    break;
1532       case SQLITE_CANTOPEN_FULLPATH:  zName = "SQLITE_CANTOPEN_FULLPATH"; break;
1533       case SQLITE_CANTOPEN_CONVPATH:  zName = "SQLITE_CANTOPEN_CONVPATH"; break;
1534       case SQLITE_CANTOPEN_SYMLINK:   zName = "SQLITE_CANTOPEN_SYMLINK";  break;
1535       case SQLITE_PROTOCOL:           zName = "SQLITE_PROTOCOL";          break;
1536       case SQLITE_EMPTY:              zName = "SQLITE_EMPTY";             break;
1537       case SQLITE_SCHEMA:             zName = "SQLITE_SCHEMA";            break;
1538       case SQLITE_TOOBIG:             zName = "SQLITE_TOOBIG";            break;
1539       case SQLITE_CONSTRAINT:         zName = "SQLITE_CONSTRAINT";        break;
1540       case SQLITE_CONSTRAINT_UNIQUE:  zName = "SQLITE_CONSTRAINT_UNIQUE"; break;
1541       case SQLITE_CONSTRAINT_TRIGGER: zName = "SQLITE_CONSTRAINT_TRIGGER";break;
1542       case SQLITE_CONSTRAINT_FOREIGNKEY:
1543                                 zName = "SQLITE_CONSTRAINT_FOREIGNKEY";   break;
1544       case SQLITE_CONSTRAINT_CHECK:   zName = "SQLITE_CONSTRAINT_CHECK";  break;
1545       case SQLITE_CONSTRAINT_PRIMARYKEY:
1546                                 zName = "SQLITE_CONSTRAINT_PRIMARYKEY";   break;
1547       case SQLITE_CONSTRAINT_NOTNULL: zName = "SQLITE_CONSTRAINT_NOTNULL";break;
1548       case SQLITE_CONSTRAINT_COMMITHOOK:
1549                                 zName = "SQLITE_CONSTRAINT_COMMITHOOK";   break;
1550       case SQLITE_CONSTRAINT_VTAB:    zName = "SQLITE_CONSTRAINT_VTAB";   break;
1551       case SQLITE_CONSTRAINT_FUNCTION:
1552                                 zName = "SQLITE_CONSTRAINT_FUNCTION";     break;
1553       case SQLITE_CONSTRAINT_ROWID:   zName = "SQLITE_CONSTRAINT_ROWID";  break;
1554       case SQLITE_MISMATCH:           zName = "SQLITE_MISMATCH";          break;
1555       case SQLITE_MISUSE:             zName = "SQLITE_MISUSE";            break;
1556       case SQLITE_NOLFS:              zName = "SQLITE_NOLFS";             break;
1557       case SQLITE_AUTH:               zName = "SQLITE_AUTH";              break;
1558       case SQLITE_FORMAT:             zName = "SQLITE_FORMAT";            break;
1559       case SQLITE_RANGE:              zName = "SQLITE_RANGE";             break;
1560       case SQLITE_NOTADB:             zName = "SQLITE_NOTADB";            break;
1561       case SQLITE_ROW:                zName = "SQLITE_ROW";               break;
1562       case SQLITE_NOTICE:             zName = "SQLITE_NOTICE";            break;
1563       case SQLITE_NOTICE_RECOVER_WAL: zName = "SQLITE_NOTICE_RECOVER_WAL";break;
1564       case SQLITE_NOTICE_RECOVER_ROLLBACK:
1565                                 zName = "SQLITE_NOTICE_RECOVER_ROLLBACK"; break;
1566       case SQLITE_WARNING:            zName = "SQLITE_WARNING";           break;
1567       case SQLITE_WARNING_AUTOINDEX:  zName = "SQLITE_WARNING_AUTOINDEX"; break;
1568       case SQLITE_DONE:               zName = "SQLITE_DONE";              break;
1569     }
1570   }
1571   if( zName==0 ){
1572     static char zBuf[50];
1573     sqlite3_snprintf(sizeof(zBuf), zBuf, "SQLITE_UNKNOWN(%d)", origRc);
1574     zName = zBuf;
1575   }
1576   return zName;
1577 }
1578 #endif
1579 
1580 /*
1581 ** Return a static string that describes the kind of error specified in the
1582 ** argument.
1583 */
1584 const char *sqlite3ErrStr(int rc){
1585   static const char* const aMsg[] = {
1586     /* SQLITE_OK          */ "not an error",
1587     /* SQLITE_ERROR       */ "SQL logic error",
1588     /* SQLITE_INTERNAL    */ 0,
1589     /* SQLITE_PERM        */ "access permission denied",
1590     /* SQLITE_ABORT       */ "query aborted",
1591     /* SQLITE_BUSY        */ "database is locked",
1592     /* SQLITE_LOCKED      */ "database table is locked",
1593     /* SQLITE_NOMEM       */ "out of memory",
1594     /* SQLITE_READONLY    */ "attempt to write a readonly database",
1595     /* SQLITE_INTERRUPT   */ "interrupted",
1596     /* SQLITE_IOERR       */ "disk I/O error",
1597     /* SQLITE_CORRUPT     */ "database disk image is malformed",
1598     /* SQLITE_NOTFOUND    */ "unknown operation",
1599     /* SQLITE_FULL        */ "database or disk is full",
1600     /* SQLITE_CANTOPEN    */ "unable to open database file",
1601     /* SQLITE_PROTOCOL    */ "locking protocol",
1602     /* SQLITE_EMPTY       */ 0,
1603     /* SQLITE_SCHEMA      */ "database schema has changed",
1604     /* SQLITE_TOOBIG      */ "string or blob too big",
1605     /* SQLITE_CONSTRAINT  */ "constraint failed",
1606     /* SQLITE_MISMATCH    */ "datatype mismatch",
1607     /* SQLITE_MISUSE      */ "bad parameter or other API misuse",
1608 #ifdef SQLITE_DISABLE_LFS
1609     /* SQLITE_NOLFS       */ "large file support is disabled",
1610 #else
1611     /* SQLITE_NOLFS       */ 0,
1612 #endif
1613     /* SQLITE_AUTH        */ "authorization denied",
1614     /* SQLITE_FORMAT      */ 0,
1615     /* SQLITE_RANGE       */ "column index out of range",
1616     /* SQLITE_NOTADB      */ "file is not a database",
1617     /* SQLITE_NOTICE      */ "notification message",
1618     /* SQLITE_WARNING     */ "warning message",
1619   };
1620   const char *zErr = "unknown error";
1621   switch( rc ){
1622     case SQLITE_ABORT_ROLLBACK: {
1623       zErr = "abort due to ROLLBACK";
1624       break;
1625     }
1626     case SQLITE_ROW: {
1627       zErr = "another row available";
1628       break;
1629     }
1630     case SQLITE_DONE: {
1631       zErr = "no more rows available";
1632       break;
1633     }
1634     default: {
1635       rc &= 0xff;
1636       if( ALWAYS(rc>=0) && rc<ArraySize(aMsg) && aMsg[rc]!=0 ){
1637         zErr = aMsg[rc];
1638       }
1639       break;
1640     }
1641   }
1642   return zErr;
1643 }
1644 
1645 /*
1646 ** This routine implements a busy callback that sleeps and tries
1647 ** again until a timeout value is reached.  The timeout value is
1648 ** an integer number of milliseconds passed in as the first
1649 ** argument.
1650 **
1651 ** Return non-zero to retry the lock.  Return zero to stop trying
1652 ** and cause SQLite to return SQLITE_BUSY.
1653 */
1654 static int sqliteDefaultBusyCallback(
1655   void *ptr,               /* Database connection */
1656   int count                /* Number of times table has been busy */
1657 ){
1658 #if SQLITE_OS_WIN || HAVE_USLEEP
1659   /* This case is for systems that have support for sleeping for fractions of
1660   ** a second.  Examples:  All windows systems, unix systems with usleep() */
1661   static const u8 delays[] =
1662      { 1, 2, 5, 10, 15, 20, 25, 25,  25,  50,  50, 100 };
1663   static const u8 totals[] =
1664      { 0, 1, 3,  8, 18, 33, 53, 78, 103, 128, 178, 228 };
1665 # define NDELAY ArraySize(delays)
1666   sqlite3 *db = (sqlite3 *)ptr;
1667   int tmout = db->busyTimeout;
1668   int delay, prior;
1669 
1670   assert( count>=0 );
1671   if( count < NDELAY ){
1672     delay = delays[count];
1673     prior = totals[count];
1674   }else{
1675     delay = delays[NDELAY-1];
1676     prior = totals[NDELAY-1] + delay*(count-(NDELAY-1));
1677   }
1678   if( prior + delay > tmout ){
1679     delay = tmout - prior;
1680     if( delay<=0 ) return 0;
1681   }
1682   sqlite3OsSleep(db->pVfs, delay*1000);
1683   return 1;
1684 #else
1685   /* This case for unix systems that lack usleep() support.  Sleeping
1686   ** must be done in increments of whole seconds */
1687   sqlite3 *db = (sqlite3 *)ptr;
1688   int tmout = ((sqlite3 *)ptr)->busyTimeout;
1689   if( (count+1)*1000 > tmout ){
1690     return 0;
1691   }
1692   sqlite3OsSleep(db->pVfs, 1000000);
1693   return 1;
1694 #endif
1695 }
1696 
1697 /*
1698 ** Invoke the given busy handler.
1699 **
1700 ** This routine is called when an operation failed to acquire a
1701 ** lock on VFS file pFile.
1702 **
1703 ** If this routine returns non-zero, the lock is retried.  If it
1704 ** returns 0, the operation aborts with an SQLITE_BUSY error.
1705 */
1706 int sqlite3InvokeBusyHandler(BusyHandler *p){
1707   int rc;
1708   if( p->xBusyHandler==0 || p->nBusy<0 ) return 0;
1709   rc = p->xBusyHandler(p->pBusyArg, p->nBusy);
1710   if( rc==0 ){
1711     p->nBusy = -1;
1712   }else{
1713     p->nBusy++;
1714   }
1715   return rc;
1716 }
1717 
1718 /*
1719 ** This routine sets the busy callback for an Sqlite database to the
1720 ** given callback function with the given argument.
1721 */
1722 int sqlite3_busy_handler(
1723   sqlite3 *db,
1724   int (*xBusy)(void*,int),
1725   void *pArg
1726 ){
1727 #ifdef SQLITE_ENABLE_API_ARMOR
1728   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
1729 #endif
1730   sqlite3_mutex_enter(db->mutex);
1731   db->busyHandler.xBusyHandler = xBusy;
1732   db->busyHandler.pBusyArg = pArg;
1733   db->busyHandler.nBusy = 0;
1734   db->busyTimeout = 0;
1735   sqlite3_mutex_leave(db->mutex);
1736   return SQLITE_OK;
1737 }
1738 
1739 #ifndef SQLITE_OMIT_PROGRESS_CALLBACK
1740 /*
1741 ** This routine sets the progress callback for an Sqlite database to the
1742 ** given callback function with the given argument. The progress callback will
1743 ** be invoked every nOps opcodes.
1744 */
1745 void sqlite3_progress_handler(
1746   sqlite3 *db,
1747   int nOps,
1748   int (*xProgress)(void*),
1749   void *pArg
1750 ){
1751 #ifdef SQLITE_ENABLE_API_ARMOR
1752   if( !sqlite3SafetyCheckOk(db) ){
1753     (void)SQLITE_MISUSE_BKPT;
1754     return;
1755   }
1756 #endif
1757   sqlite3_mutex_enter(db->mutex);
1758   if( nOps>0 ){
1759     db->xProgress = xProgress;
1760     db->nProgressOps = (unsigned)nOps;
1761     db->pProgressArg = pArg;
1762   }else{
1763     db->xProgress = 0;
1764     db->nProgressOps = 0;
1765     db->pProgressArg = 0;
1766   }
1767   sqlite3_mutex_leave(db->mutex);
1768 }
1769 #endif
1770 
1771 
1772 /*
1773 ** This routine installs a default busy handler that waits for the
1774 ** specified number of milliseconds before returning 0.
1775 */
1776 int sqlite3_busy_timeout(sqlite3 *db, int ms){
1777 #ifdef SQLITE_ENABLE_API_ARMOR
1778   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
1779 #endif
1780   if( ms>0 ){
1781     sqlite3_busy_handler(db, (int(*)(void*,int))sqliteDefaultBusyCallback,
1782                              (void*)db);
1783     db->busyTimeout = ms;
1784   }else{
1785     sqlite3_busy_handler(db, 0, 0);
1786   }
1787   return SQLITE_OK;
1788 }
1789 
1790 /*
1791 ** Cause any pending operation to stop at its earliest opportunity.
1792 */
1793 void sqlite3_interrupt(sqlite3 *db){
1794 #ifdef SQLITE_ENABLE_API_ARMOR
1795   if( !sqlite3SafetyCheckOk(db) && (db==0 || db->eOpenState!=SQLITE_STATE_ZOMBIE) ){
1796     (void)SQLITE_MISUSE_BKPT;
1797     return;
1798   }
1799 #endif
1800   AtomicStore(&db->u1.isInterrupted, 1);
1801 }
1802 
1803 
1804 /*
1805 ** This function is exactly the same as sqlite3_create_function(), except
1806 ** that it is designed to be called by internal code. The difference is
1807 ** that if a malloc() fails in sqlite3_create_function(), an error code
1808 ** is returned and the mallocFailed flag cleared.
1809 */
1810 int sqlite3CreateFunc(
1811   sqlite3 *db,
1812   const char *zFunctionName,
1813   int nArg,
1814   int enc,
1815   void *pUserData,
1816   void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
1817   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
1818   void (*xFinal)(sqlite3_context*),
1819   void (*xValue)(sqlite3_context*),
1820   void (*xInverse)(sqlite3_context*,int,sqlite3_value **),
1821   FuncDestructor *pDestructor
1822 ){
1823   FuncDef *p;
1824   int extraFlags;
1825 
1826   assert( sqlite3_mutex_held(db->mutex) );
1827   assert( xValue==0 || xSFunc==0 );
1828   if( zFunctionName==0                /* Must have a valid name */
1829    || (xSFunc!=0 && xFinal!=0)        /* Not both xSFunc and xFinal */
1830    || ((xFinal==0)!=(xStep==0))       /* Both or neither of xFinal and xStep */
1831    || ((xValue==0)!=(xInverse==0))    /* Both or neither of xValue, xInverse */
1832    || (nArg<-1 || nArg>SQLITE_MAX_FUNCTION_ARG)
1833    || (255<sqlite3Strlen30(zFunctionName))
1834   ){
1835     return SQLITE_MISUSE_BKPT;
1836   }
1837 
1838   assert( SQLITE_FUNC_CONSTANT==SQLITE_DETERMINISTIC );
1839   assert( SQLITE_FUNC_DIRECT==SQLITE_DIRECTONLY );
1840   extraFlags = enc &  (SQLITE_DETERMINISTIC|SQLITE_DIRECTONLY|
1841                        SQLITE_SUBTYPE|SQLITE_INNOCUOUS);
1842   enc &= (SQLITE_FUNC_ENCMASK|SQLITE_ANY);
1843 
1844   /* The SQLITE_INNOCUOUS flag is the same bit as SQLITE_FUNC_UNSAFE.  But
1845   ** the meaning is inverted.  So flip the bit. */
1846   assert( SQLITE_FUNC_UNSAFE==SQLITE_INNOCUOUS );
1847   extraFlags ^= SQLITE_FUNC_UNSAFE;
1848 
1849 
1850 #ifndef SQLITE_OMIT_UTF16
1851   /* If SQLITE_UTF16 is specified as the encoding type, transform this
1852   ** to one of SQLITE_UTF16LE or SQLITE_UTF16BE using the
1853   ** SQLITE_UTF16NATIVE macro. SQLITE_UTF16 is not used internally.
1854   **
1855   ** If SQLITE_ANY is specified, add three versions of the function
1856   ** to the hash table.
1857   */
1858   switch( enc ){
1859     case SQLITE_UTF16:
1860       enc = SQLITE_UTF16NATIVE;
1861       break;
1862     case SQLITE_ANY: {
1863       int rc;
1864       rc = sqlite3CreateFunc(db, zFunctionName, nArg,
1865            (SQLITE_UTF8|extraFlags)^SQLITE_FUNC_UNSAFE,
1866            pUserData, xSFunc, xStep, xFinal, xValue, xInverse, pDestructor);
1867       if( rc==SQLITE_OK ){
1868         rc = sqlite3CreateFunc(db, zFunctionName, nArg,
1869              (SQLITE_UTF16LE|extraFlags)^SQLITE_FUNC_UNSAFE,
1870              pUserData, xSFunc, xStep, xFinal, xValue, xInverse, pDestructor);
1871       }
1872       if( rc!=SQLITE_OK ){
1873         return rc;
1874       }
1875       enc = SQLITE_UTF16BE;
1876       break;
1877     }
1878     case SQLITE_UTF8:
1879     case SQLITE_UTF16LE:
1880     case SQLITE_UTF16BE:
1881       break;
1882     default:
1883       enc = SQLITE_UTF8;
1884       break;
1885   }
1886 #else
1887   enc = SQLITE_UTF8;
1888 #endif
1889 
1890   /* Check if an existing function is being overridden or deleted. If so,
1891   ** and there are active VMs, then return SQLITE_BUSY. If a function
1892   ** is being overridden/deleted but there are no active VMs, allow the
1893   ** operation to continue but invalidate all precompiled statements.
1894   */
1895   p = sqlite3FindFunction(db, zFunctionName, nArg, (u8)enc, 0);
1896   if( p && (p->funcFlags & SQLITE_FUNC_ENCMASK)==(u32)enc && p->nArg==nArg ){
1897     if( db->nVdbeActive ){
1898       sqlite3ErrorWithMsg(db, SQLITE_BUSY,
1899         "unable to delete/modify user-function due to active statements");
1900       assert( !db->mallocFailed );
1901       return SQLITE_BUSY;
1902     }else{
1903       sqlite3ExpirePreparedStatements(db, 0);
1904     }
1905   }else if( xSFunc==0 && xFinal==0 ){
1906     /* Trying to delete a function that does not exist.  This is a no-op.
1907     ** https://sqlite.org/forum/forumpost/726219164b */
1908     return SQLITE_OK;
1909   }
1910 
1911   p = sqlite3FindFunction(db, zFunctionName, nArg, (u8)enc, 1);
1912   assert(p || db->mallocFailed);
1913   if( !p ){
1914     return SQLITE_NOMEM_BKPT;
1915   }
1916 
1917   /* If an older version of the function with a configured destructor is
1918   ** being replaced invoke the destructor function here. */
1919   functionDestroy(db, p);
1920 
1921   if( pDestructor ){
1922     pDestructor->nRef++;
1923   }
1924   p->u.pDestructor = pDestructor;
1925   p->funcFlags = (p->funcFlags & SQLITE_FUNC_ENCMASK) | extraFlags;
1926   testcase( p->funcFlags & SQLITE_DETERMINISTIC );
1927   testcase( p->funcFlags & SQLITE_DIRECTONLY );
1928   p->xSFunc = xSFunc ? xSFunc : xStep;
1929   p->xFinalize = xFinal;
1930   p->xValue = xValue;
1931   p->xInverse = xInverse;
1932   p->pUserData = pUserData;
1933   p->nArg = (u16)nArg;
1934   return SQLITE_OK;
1935 }
1936 
1937 /*
1938 ** Worker function used by utf-8 APIs that create new functions:
1939 **
1940 **    sqlite3_create_function()
1941 **    sqlite3_create_function_v2()
1942 **    sqlite3_create_window_function()
1943 */
1944 static int createFunctionApi(
1945   sqlite3 *db,
1946   const char *zFunc,
1947   int nArg,
1948   int enc,
1949   void *p,
1950   void (*xSFunc)(sqlite3_context*,int,sqlite3_value**),
1951   void (*xStep)(sqlite3_context*,int,sqlite3_value**),
1952   void (*xFinal)(sqlite3_context*),
1953   void (*xValue)(sqlite3_context*),
1954   void (*xInverse)(sqlite3_context*,int,sqlite3_value**),
1955   void(*xDestroy)(void*)
1956 ){
1957   int rc = SQLITE_ERROR;
1958   FuncDestructor *pArg = 0;
1959 
1960 #ifdef SQLITE_ENABLE_API_ARMOR
1961   if( !sqlite3SafetyCheckOk(db) ){
1962     return SQLITE_MISUSE_BKPT;
1963   }
1964 #endif
1965   sqlite3_mutex_enter(db->mutex);
1966   if( xDestroy ){
1967     pArg = (FuncDestructor *)sqlite3Malloc(sizeof(FuncDestructor));
1968     if( !pArg ){
1969       sqlite3OomFault(db);
1970       xDestroy(p);
1971       goto out;
1972     }
1973     pArg->nRef = 0;
1974     pArg->xDestroy = xDestroy;
1975     pArg->pUserData = p;
1976   }
1977   rc = sqlite3CreateFunc(db, zFunc, nArg, enc, p,
1978       xSFunc, xStep, xFinal, xValue, xInverse, pArg
1979   );
1980   if( pArg && pArg->nRef==0 ){
1981     assert( rc!=SQLITE_OK || (xStep==0 && xFinal==0) );
1982     xDestroy(p);
1983     sqlite3_free(pArg);
1984   }
1985 
1986  out:
1987   rc = sqlite3ApiExit(db, rc);
1988   sqlite3_mutex_leave(db->mutex);
1989   return rc;
1990 }
1991 
1992 /*
1993 ** Create new user functions.
1994 */
1995 int sqlite3_create_function(
1996   sqlite3 *db,
1997   const char *zFunc,
1998   int nArg,
1999   int enc,
2000   void *p,
2001   void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
2002   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
2003   void (*xFinal)(sqlite3_context*)
2004 ){
2005   return createFunctionApi(db, zFunc, nArg, enc, p, xSFunc, xStep,
2006                                     xFinal, 0, 0, 0);
2007 }
2008 int sqlite3_create_function_v2(
2009   sqlite3 *db,
2010   const char *zFunc,
2011   int nArg,
2012   int enc,
2013   void *p,
2014   void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
2015   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
2016   void (*xFinal)(sqlite3_context*),
2017   void (*xDestroy)(void *)
2018 ){
2019   return createFunctionApi(db, zFunc, nArg, enc, p, xSFunc, xStep,
2020                                     xFinal, 0, 0, xDestroy);
2021 }
2022 int sqlite3_create_window_function(
2023   sqlite3 *db,
2024   const char *zFunc,
2025   int nArg,
2026   int enc,
2027   void *p,
2028   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
2029   void (*xFinal)(sqlite3_context*),
2030   void (*xValue)(sqlite3_context*),
2031   void (*xInverse)(sqlite3_context*,int,sqlite3_value **),
2032   void (*xDestroy)(void *)
2033 ){
2034   return createFunctionApi(db, zFunc, nArg, enc, p, 0, xStep,
2035                                     xFinal, xValue, xInverse, xDestroy);
2036 }
2037 
2038 #ifndef SQLITE_OMIT_UTF16
2039 int sqlite3_create_function16(
2040   sqlite3 *db,
2041   const void *zFunctionName,
2042   int nArg,
2043   int eTextRep,
2044   void *p,
2045   void (*xSFunc)(sqlite3_context*,int,sqlite3_value**),
2046   void (*xStep)(sqlite3_context*,int,sqlite3_value**),
2047   void (*xFinal)(sqlite3_context*)
2048 ){
2049   int rc;
2050   char *zFunc8;
2051 
2052 #ifdef SQLITE_ENABLE_API_ARMOR
2053   if( !sqlite3SafetyCheckOk(db) || zFunctionName==0 ) return SQLITE_MISUSE_BKPT;
2054 #endif
2055   sqlite3_mutex_enter(db->mutex);
2056   assert( !db->mallocFailed );
2057   zFunc8 = sqlite3Utf16to8(db, zFunctionName, -1, SQLITE_UTF16NATIVE);
2058   rc = sqlite3CreateFunc(db, zFunc8, nArg, eTextRep, p, xSFunc,xStep,xFinal,0,0,0);
2059   sqlite3DbFree(db, zFunc8);
2060   rc = sqlite3ApiExit(db, rc);
2061   sqlite3_mutex_leave(db->mutex);
2062   return rc;
2063 }
2064 #endif
2065 
2066 
2067 /*
2068 ** The following is the implementation of an SQL function that always
2069 ** fails with an error message stating that the function is used in the
2070 ** wrong context.  The sqlite3_overload_function() API might construct
2071 ** SQL function that use this routine so that the functions will exist
2072 ** for name resolution but are actually overloaded by the xFindFunction
2073 ** method of virtual tables.
2074 */
2075 static void sqlite3InvalidFunction(
2076   sqlite3_context *context,  /* The function calling context */
2077   int NotUsed,               /* Number of arguments to the function */
2078   sqlite3_value **NotUsed2   /* Value of each argument */
2079 ){
2080   const char *zName = (const char*)sqlite3_user_data(context);
2081   char *zErr;
2082   UNUSED_PARAMETER2(NotUsed, NotUsed2);
2083   zErr = sqlite3_mprintf(
2084       "unable to use function %s in the requested context", zName);
2085   sqlite3_result_error(context, zErr, -1);
2086   sqlite3_free(zErr);
2087 }
2088 
2089 /*
2090 ** Declare that a function has been overloaded by a virtual table.
2091 **
2092 ** If the function already exists as a regular global function, then
2093 ** this routine is a no-op.  If the function does not exist, then create
2094 ** a new one that always throws a run-time error.
2095 **
2096 ** When virtual tables intend to provide an overloaded function, they
2097 ** should call this routine to make sure the global function exists.
2098 ** A global function must exist in order for name resolution to work
2099 ** properly.
2100 */
2101 int sqlite3_overload_function(
2102   sqlite3 *db,
2103   const char *zName,
2104   int nArg
2105 ){
2106   int rc;
2107   char *zCopy;
2108 
2109 #ifdef SQLITE_ENABLE_API_ARMOR
2110   if( !sqlite3SafetyCheckOk(db) || zName==0 || nArg<-2 ){
2111     return SQLITE_MISUSE_BKPT;
2112   }
2113 #endif
2114   sqlite3_mutex_enter(db->mutex);
2115   rc = sqlite3FindFunction(db, zName, nArg, SQLITE_UTF8, 0)!=0;
2116   sqlite3_mutex_leave(db->mutex);
2117   if( rc ) return SQLITE_OK;
2118   zCopy = sqlite3_mprintf(zName);
2119   if( zCopy==0 ) return SQLITE_NOMEM;
2120   return sqlite3_create_function_v2(db, zName, nArg, SQLITE_UTF8,
2121                            zCopy, sqlite3InvalidFunction, 0, 0, sqlite3_free);
2122 }
2123 
2124 #ifndef SQLITE_OMIT_TRACE
2125 /*
2126 ** Register a trace function.  The pArg from the previously registered trace
2127 ** is returned.
2128 **
2129 ** A NULL trace function means that no tracing is executes.  A non-NULL
2130 ** trace is a pointer to a function that is invoked at the start of each
2131 ** SQL statement.
2132 */
2133 #ifndef SQLITE_OMIT_DEPRECATED
2134 void *sqlite3_trace(sqlite3 *db, void(*xTrace)(void*,const char*), void *pArg){
2135   void *pOld;
2136 
2137 #ifdef SQLITE_ENABLE_API_ARMOR
2138   if( !sqlite3SafetyCheckOk(db) ){
2139     (void)SQLITE_MISUSE_BKPT;
2140     return 0;
2141   }
2142 #endif
2143   sqlite3_mutex_enter(db->mutex);
2144   pOld = db->pTraceArg;
2145   db->mTrace = xTrace ? SQLITE_TRACE_LEGACY : 0;
2146   db->trace.xLegacy = xTrace;
2147   db->pTraceArg = pArg;
2148   sqlite3_mutex_leave(db->mutex);
2149   return pOld;
2150 }
2151 #endif /* SQLITE_OMIT_DEPRECATED */
2152 
2153 /* Register a trace callback using the version-2 interface.
2154 */
2155 int sqlite3_trace_v2(
2156   sqlite3 *db,                               /* Trace this connection */
2157   unsigned mTrace,                           /* Mask of events to be traced */
2158   int(*xTrace)(unsigned,void*,void*,void*),  /* Callback to invoke */
2159   void *pArg                                 /* Context */
2160 ){
2161 #ifdef SQLITE_ENABLE_API_ARMOR
2162   if( !sqlite3SafetyCheckOk(db) ){
2163     return SQLITE_MISUSE_BKPT;
2164   }
2165 #endif
2166   sqlite3_mutex_enter(db->mutex);
2167   if( mTrace==0 ) xTrace = 0;
2168   if( xTrace==0 ) mTrace = 0;
2169   db->mTrace = mTrace;
2170   db->trace.xV2 = xTrace;
2171   db->pTraceArg = pArg;
2172   sqlite3_mutex_leave(db->mutex);
2173   return SQLITE_OK;
2174 }
2175 
2176 #ifndef SQLITE_OMIT_DEPRECATED
2177 /*
2178 ** Register a profile function.  The pArg from the previously registered
2179 ** profile function is returned.
2180 **
2181 ** A NULL profile function means that no profiling is executes.  A non-NULL
2182 ** profile is a pointer to a function that is invoked at the conclusion of
2183 ** each SQL statement that is run.
2184 */
2185 void *sqlite3_profile(
2186   sqlite3 *db,
2187   void (*xProfile)(void*,const char*,sqlite_uint64),
2188   void *pArg
2189 ){
2190   void *pOld;
2191 
2192 #ifdef SQLITE_ENABLE_API_ARMOR
2193   if( !sqlite3SafetyCheckOk(db) ){
2194     (void)SQLITE_MISUSE_BKPT;
2195     return 0;
2196   }
2197 #endif
2198   sqlite3_mutex_enter(db->mutex);
2199   pOld = db->pProfileArg;
2200   db->xProfile = xProfile;
2201   db->pProfileArg = pArg;
2202   db->mTrace &= SQLITE_TRACE_NONLEGACY_MASK;
2203   if( db->xProfile ) db->mTrace |= SQLITE_TRACE_XPROFILE;
2204   sqlite3_mutex_leave(db->mutex);
2205   return pOld;
2206 }
2207 #endif /* SQLITE_OMIT_DEPRECATED */
2208 #endif /* SQLITE_OMIT_TRACE */
2209 
2210 /*
2211 ** Register a function to be invoked when a transaction commits.
2212 ** If the invoked function returns non-zero, then the commit becomes a
2213 ** rollback.
2214 */
2215 void *sqlite3_commit_hook(
2216   sqlite3 *db,              /* Attach the hook to this database */
2217   int (*xCallback)(void*),  /* Function to invoke on each commit */
2218   void *pArg                /* Argument to the function */
2219 ){
2220   void *pOld;
2221 
2222 #ifdef SQLITE_ENABLE_API_ARMOR
2223   if( !sqlite3SafetyCheckOk(db) ){
2224     (void)SQLITE_MISUSE_BKPT;
2225     return 0;
2226   }
2227 #endif
2228   sqlite3_mutex_enter(db->mutex);
2229   pOld = db->pCommitArg;
2230   db->xCommitCallback = xCallback;
2231   db->pCommitArg = pArg;
2232   sqlite3_mutex_leave(db->mutex);
2233   return pOld;
2234 }
2235 
2236 /*
2237 ** Register a callback to be invoked each time a row is updated,
2238 ** inserted or deleted using this database connection.
2239 */
2240 void *sqlite3_update_hook(
2241   sqlite3 *db,              /* Attach the hook to this database */
2242   void (*xCallback)(void*,int,char const *,char const *,sqlite_int64),
2243   void *pArg                /* Argument to the function */
2244 ){
2245   void *pRet;
2246 
2247 #ifdef SQLITE_ENABLE_API_ARMOR
2248   if( !sqlite3SafetyCheckOk(db) ){
2249     (void)SQLITE_MISUSE_BKPT;
2250     return 0;
2251   }
2252 #endif
2253   sqlite3_mutex_enter(db->mutex);
2254   pRet = db->pUpdateArg;
2255   db->xUpdateCallback = xCallback;
2256   db->pUpdateArg = pArg;
2257   sqlite3_mutex_leave(db->mutex);
2258   return pRet;
2259 }
2260 
2261 /*
2262 ** Register a callback to be invoked each time a transaction is rolled
2263 ** back by this database connection.
2264 */
2265 void *sqlite3_rollback_hook(
2266   sqlite3 *db,              /* Attach the hook to this database */
2267   void (*xCallback)(void*), /* Callback function */
2268   void *pArg                /* Argument to the function */
2269 ){
2270   void *pRet;
2271 
2272 #ifdef SQLITE_ENABLE_API_ARMOR
2273   if( !sqlite3SafetyCheckOk(db) ){
2274     (void)SQLITE_MISUSE_BKPT;
2275     return 0;
2276   }
2277 #endif
2278   sqlite3_mutex_enter(db->mutex);
2279   pRet = db->pRollbackArg;
2280   db->xRollbackCallback = xCallback;
2281   db->pRollbackArg = pArg;
2282   sqlite3_mutex_leave(db->mutex);
2283   return pRet;
2284 }
2285 
2286 #ifdef SQLITE_ENABLE_PREUPDATE_HOOK
2287 /*
2288 ** Register a callback to be invoked each time a row is updated,
2289 ** inserted or deleted using this database connection.
2290 */
2291 void *sqlite3_preupdate_hook(
2292   sqlite3 *db,              /* Attach the hook to this database */
2293   void(*xCallback)(         /* Callback function */
2294     void*,sqlite3*,int,char const*,char const*,sqlite3_int64,sqlite3_int64),
2295   void *pArg                /* First callback argument */
2296 ){
2297   void *pRet;
2298   sqlite3_mutex_enter(db->mutex);
2299   pRet = db->pPreUpdateArg;
2300   db->xPreUpdateCallback = xCallback;
2301   db->pPreUpdateArg = pArg;
2302   sqlite3_mutex_leave(db->mutex);
2303   return pRet;
2304 }
2305 #endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
2306 
2307 #ifndef SQLITE_OMIT_WAL
2308 /*
2309 ** The sqlite3_wal_hook() callback registered by sqlite3_wal_autocheckpoint().
2310 ** Invoke sqlite3_wal_checkpoint if the number of frames in the log file
2311 ** is greater than sqlite3.pWalArg cast to an integer (the value configured by
2312 ** wal_autocheckpoint()).
2313 */
2314 int sqlite3WalDefaultHook(
2315   void *pClientData,     /* Argument */
2316   sqlite3 *db,           /* Connection */
2317   const char *zDb,       /* Database */
2318   int nFrame             /* Size of WAL */
2319 ){
2320   if( nFrame>=SQLITE_PTR_TO_INT(pClientData) ){
2321     sqlite3BeginBenignMalloc();
2322     sqlite3_wal_checkpoint(db, zDb);
2323     sqlite3EndBenignMalloc();
2324   }
2325   return SQLITE_OK;
2326 }
2327 #endif /* SQLITE_OMIT_WAL */
2328 
2329 /*
2330 ** Configure an sqlite3_wal_hook() callback to automatically checkpoint
2331 ** a database after committing a transaction if there are nFrame or
2332 ** more frames in the log file. Passing zero or a negative value as the
2333 ** nFrame parameter disables automatic checkpoints entirely.
2334 **
2335 ** The callback registered by this function replaces any existing callback
2336 ** registered using sqlite3_wal_hook(). Likewise, registering a callback
2337 ** using sqlite3_wal_hook() disables the automatic checkpoint mechanism
2338 ** configured by this function.
2339 */
2340 int sqlite3_wal_autocheckpoint(sqlite3 *db, int nFrame){
2341 #ifdef SQLITE_OMIT_WAL
2342   UNUSED_PARAMETER(db);
2343   UNUSED_PARAMETER(nFrame);
2344 #else
2345 #ifdef SQLITE_ENABLE_API_ARMOR
2346   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
2347 #endif
2348   if( nFrame>0 ){
2349     sqlite3_wal_hook(db, sqlite3WalDefaultHook, SQLITE_INT_TO_PTR(nFrame));
2350   }else{
2351     sqlite3_wal_hook(db, 0, 0);
2352   }
2353 #endif
2354   return SQLITE_OK;
2355 }
2356 
2357 /*
2358 ** Register a callback to be invoked each time a transaction is written
2359 ** into the write-ahead-log by this database connection.
2360 */
2361 void *sqlite3_wal_hook(
2362   sqlite3 *db,                    /* Attach the hook to this db handle */
2363   int(*xCallback)(void *, sqlite3*, const char*, int),
2364   void *pArg                      /* First argument passed to xCallback() */
2365 ){
2366 #ifndef SQLITE_OMIT_WAL
2367   void *pRet;
2368 #ifdef SQLITE_ENABLE_API_ARMOR
2369   if( !sqlite3SafetyCheckOk(db) ){
2370     (void)SQLITE_MISUSE_BKPT;
2371     return 0;
2372   }
2373 #endif
2374   sqlite3_mutex_enter(db->mutex);
2375   pRet = db->pWalArg;
2376   db->xWalCallback = xCallback;
2377   db->pWalArg = pArg;
2378   sqlite3_mutex_leave(db->mutex);
2379   return pRet;
2380 #else
2381   return 0;
2382 #endif
2383 }
2384 
2385 /*
2386 ** Checkpoint database zDb.
2387 */
2388 int sqlite3_wal_checkpoint_v2(
2389   sqlite3 *db,                    /* Database handle */
2390   const char *zDb,                /* Name of attached database (or NULL) */
2391   int eMode,                      /* SQLITE_CHECKPOINT_* value */
2392   int *pnLog,                     /* OUT: Size of WAL log in frames */
2393   int *pnCkpt                     /* OUT: Total number of frames checkpointed */
2394 ){
2395 #ifdef SQLITE_OMIT_WAL
2396   return SQLITE_OK;
2397 #else
2398   int rc;                         /* Return code */
2399   int iDb;                        /* Schema to checkpoint */
2400 
2401 #ifdef SQLITE_ENABLE_API_ARMOR
2402   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
2403 #endif
2404 
2405   /* Initialize the output variables to -1 in case an error occurs. */
2406   if( pnLog ) *pnLog = -1;
2407   if( pnCkpt ) *pnCkpt = -1;
2408 
2409   assert( SQLITE_CHECKPOINT_PASSIVE==0 );
2410   assert( SQLITE_CHECKPOINT_FULL==1 );
2411   assert( SQLITE_CHECKPOINT_RESTART==2 );
2412   assert( SQLITE_CHECKPOINT_TRUNCATE==3 );
2413   if( eMode<SQLITE_CHECKPOINT_PASSIVE || eMode>SQLITE_CHECKPOINT_TRUNCATE ){
2414     /* EVIDENCE-OF: R-03996-12088 The M parameter must be a valid checkpoint
2415     ** mode: */
2416     return SQLITE_MISUSE;
2417   }
2418 
2419   sqlite3_mutex_enter(db->mutex);
2420   if( zDb && zDb[0] ){
2421     iDb = sqlite3FindDbName(db, zDb);
2422   }else{
2423     iDb = SQLITE_MAX_DB;   /* This means process all schemas */
2424   }
2425   if( iDb<0 ){
2426     rc = SQLITE_ERROR;
2427     sqlite3ErrorWithMsg(db, SQLITE_ERROR, "unknown database: %s", zDb);
2428   }else{
2429     db->busyHandler.nBusy = 0;
2430     rc = sqlite3Checkpoint(db, iDb, eMode, pnLog, pnCkpt);
2431     sqlite3Error(db, rc);
2432   }
2433   rc = sqlite3ApiExit(db, rc);
2434 
2435   /* If there are no active statements, clear the interrupt flag at this
2436   ** point.  */
2437   if( db->nVdbeActive==0 ){
2438     AtomicStore(&db->u1.isInterrupted, 0);
2439   }
2440 
2441   sqlite3_mutex_leave(db->mutex);
2442   return rc;
2443 #endif
2444 }
2445 
2446 
2447 /*
2448 ** Checkpoint database zDb. If zDb is NULL, or if the buffer zDb points
2449 ** to contains a zero-length string, all attached databases are
2450 ** checkpointed.
2451 */
2452 int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb){
2453   /* EVIDENCE-OF: R-41613-20553 The sqlite3_wal_checkpoint(D,X) is equivalent to
2454   ** sqlite3_wal_checkpoint_v2(D,X,SQLITE_CHECKPOINT_PASSIVE,0,0). */
2455   return sqlite3_wal_checkpoint_v2(db,zDb,SQLITE_CHECKPOINT_PASSIVE,0,0);
2456 }
2457 
2458 #ifndef SQLITE_OMIT_WAL
2459 /*
2460 ** Run a checkpoint on database iDb. This is a no-op if database iDb is
2461 ** not currently open in WAL mode.
2462 **
2463 ** If a transaction is open on the database being checkpointed, this
2464 ** function returns SQLITE_LOCKED and a checkpoint is not attempted. If
2465 ** an error occurs while running the checkpoint, an SQLite error code is
2466 ** returned (i.e. SQLITE_IOERR). Otherwise, SQLITE_OK.
2467 **
2468 ** The mutex on database handle db should be held by the caller. The mutex
2469 ** associated with the specific b-tree being checkpointed is taken by
2470 ** this function while the checkpoint is running.
2471 **
2472 ** If iDb is passed SQLITE_MAX_DB then all attached databases are
2473 ** checkpointed. If an error is encountered it is returned immediately -
2474 ** no attempt is made to checkpoint any remaining databases.
2475 **
2476 ** Parameter eMode is one of SQLITE_CHECKPOINT_PASSIVE, FULL, RESTART
2477 ** or TRUNCATE.
2478 */
2479 int sqlite3Checkpoint(sqlite3 *db, int iDb, int eMode, int *pnLog, int *pnCkpt){
2480   int rc = SQLITE_OK;             /* Return code */
2481   int i;                          /* Used to iterate through attached dbs */
2482   int bBusy = 0;                  /* True if SQLITE_BUSY has been encountered */
2483 
2484   assert( sqlite3_mutex_held(db->mutex) );
2485   assert( !pnLog || *pnLog==-1 );
2486   assert( !pnCkpt || *pnCkpt==-1 );
2487   testcase( iDb==SQLITE_MAX_ATTACHED ); /* See forum post a006d86f72 */
2488   testcase( iDb==SQLITE_MAX_DB );
2489 
2490   for(i=0; i<db->nDb && rc==SQLITE_OK; i++){
2491     if( i==iDb || iDb==SQLITE_MAX_DB ){
2492       rc = sqlite3BtreeCheckpoint(db->aDb[i].pBt, eMode, pnLog, pnCkpt);
2493       pnLog = 0;
2494       pnCkpt = 0;
2495       if( rc==SQLITE_BUSY ){
2496         bBusy = 1;
2497         rc = SQLITE_OK;
2498       }
2499     }
2500   }
2501 
2502   return (rc==SQLITE_OK && bBusy) ? SQLITE_BUSY : rc;
2503 }
2504 #endif /* SQLITE_OMIT_WAL */
2505 
2506 /*
2507 ** This function returns true if main-memory should be used instead of
2508 ** a temporary file for transient pager files and statement journals.
2509 ** The value returned depends on the value of db->temp_store (runtime
2510 ** parameter) and the compile time value of SQLITE_TEMP_STORE. The
2511 ** following table describes the relationship between these two values
2512 ** and this functions return value.
2513 **
2514 **   SQLITE_TEMP_STORE     db->temp_store     Location of temporary database
2515 **   -----------------     --------------     ------------------------------
2516 **   0                     any                file      (return 0)
2517 **   1                     1                  file      (return 0)
2518 **   1                     2                  memory    (return 1)
2519 **   1                     0                  file      (return 0)
2520 **   2                     1                  file      (return 0)
2521 **   2                     2                  memory    (return 1)
2522 **   2                     0                  memory    (return 1)
2523 **   3                     any                memory    (return 1)
2524 */
2525 int sqlite3TempInMemory(const sqlite3 *db){
2526 #if SQLITE_TEMP_STORE==1
2527   return ( db->temp_store==2 );
2528 #endif
2529 #if SQLITE_TEMP_STORE==2
2530   return ( db->temp_store!=1 );
2531 #endif
2532 #if SQLITE_TEMP_STORE==3
2533   UNUSED_PARAMETER(db);
2534   return 1;
2535 #endif
2536 #if SQLITE_TEMP_STORE<1 || SQLITE_TEMP_STORE>3
2537   UNUSED_PARAMETER(db);
2538   return 0;
2539 #endif
2540 }
2541 
2542 /*
2543 ** Return UTF-8 encoded English language explanation of the most recent
2544 ** error.
2545 */
2546 const char *sqlite3_errmsg(sqlite3 *db){
2547   const char *z;
2548   if( !db ){
2549     return sqlite3ErrStr(SQLITE_NOMEM_BKPT);
2550   }
2551   if( !sqlite3SafetyCheckSickOrOk(db) ){
2552     return sqlite3ErrStr(SQLITE_MISUSE_BKPT);
2553   }
2554   sqlite3_mutex_enter(db->mutex);
2555   if( db->mallocFailed ){
2556     z = sqlite3ErrStr(SQLITE_NOMEM_BKPT);
2557   }else{
2558     testcase( db->pErr==0 );
2559     z = db->errCode ? (char*)sqlite3_value_text(db->pErr) : 0;
2560     assert( !db->mallocFailed );
2561     if( z==0 ){
2562       z = sqlite3ErrStr(db->errCode);
2563     }
2564   }
2565   sqlite3_mutex_leave(db->mutex);
2566   return z;
2567 }
2568 
2569 #ifndef SQLITE_OMIT_UTF16
2570 /*
2571 ** Return UTF-16 encoded English language explanation of the most recent
2572 ** error.
2573 */
2574 const void *sqlite3_errmsg16(sqlite3 *db){
2575   static const u16 outOfMem[] = {
2576     'o', 'u', 't', ' ', 'o', 'f', ' ', 'm', 'e', 'm', 'o', 'r', 'y', 0
2577   };
2578   static const u16 misuse[] = {
2579     'b', 'a', 'd', ' ', 'p', 'a', 'r', 'a', 'm', 'e', 't', 'e', 'r', ' ',
2580     'o', 'r', ' ', 'o', 't', 'h', 'e', 'r', ' ', 'A', 'P', 'I', ' ',
2581     'm', 'i', 's', 'u', 's', 'e', 0
2582   };
2583 
2584   const void *z;
2585   if( !db ){
2586     return (void *)outOfMem;
2587   }
2588   if( !sqlite3SafetyCheckSickOrOk(db) ){
2589     return (void *)misuse;
2590   }
2591   sqlite3_mutex_enter(db->mutex);
2592   if( db->mallocFailed ){
2593     z = (void *)outOfMem;
2594   }else{
2595     z = sqlite3_value_text16(db->pErr);
2596     if( z==0 ){
2597       sqlite3ErrorWithMsg(db, db->errCode, sqlite3ErrStr(db->errCode));
2598       z = sqlite3_value_text16(db->pErr);
2599     }
2600     /* A malloc() may have failed within the call to sqlite3_value_text16()
2601     ** above. If this is the case, then the db->mallocFailed flag needs to
2602     ** be cleared before returning. Do this directly, instead of via
2603     ** sqlite3ApiExit(), to avoid setting the database handle error message.
2604     */
2605     sqlite3OomClear(db);
2606   }
2607   sqlite3_mutex_leave(db->mutex);
2608   return z;
2609 }
2610 #endif /* SQLITE_OMIT_UTF16 */
2611 
2612 /*
2613 ** Return the most recent error code generated by an SQLite routine. If NULL is
2614 ** passed to this function, we assume a malloc() failed during sqlite3_open().
2615 */
2616 int sqlite3_errcode(sqlite3 *db){
2617   if( db && !sqlite3SafetyCheckSickOrOk(db) ){
2618     return SQLITE_MISUSE_BKPT;
2619   }
2620   if( !db || db->mallocFailed ){
2621     return SQLITE_NOMEM_BKPT;
2622   }
2623   return db->errCode & db->errMask;
2624 }
2625 int sqlite3_extended_errcode(sqlite3 *db){
2626   if( db && !sqlite3SafetyCheckSickOrOk(db) ){
2627     return SQLITE_MISUSE_BKPT;
2628   }
2629   if( !db || db->mallocFailed ){
2630     return SQLITE_NOMEM_BKPT;
2631   }
2632   return db->errCode;
2633 }
2634 int sqlite3_system_errno(sqlite3 *db){
2635   return db ? db->iSysErrno : 0;
2636 }
2637 
2638 /*
2639 ** Return a string that describes the kind of error specified in the
2640 ** argument.  For now, this simply calls the internal sqlite3ErrStr()
2641 ** function.
2642 */
2643 const char *sqlite3_errstr(int rc){
2644   return sqlite3ErrStr(rc);
2645 }
2646 
2647 /*
2648 ** Create a new collating function for database "db".  The name is zName
2649 ** and the encoding is enc.
2650 */
2651 static int createCollation(
2652   sqlite3* db,
2653   const char *zName,
2654   u8 enc,
2655   void* pCtx,
2656   int(*xCompare)(void*,int,const void*,int,const void*),
2657   void(*xDel)(void*)
2658 ){
2659   CollSeq *pColl;
2660   int enc2;
2661 
2662   assert( sqlite3_mutex_held(db->mutex) );
2663 
2664   /* If SQLITE_UTF16 is specified as the encoding type, transform this
2665   ** to one of SQLITE_UTF16LE or SQLITE_UTF16BE using the
2666   ** SQLITE_UTF16NATIVE macro. SQLITE_UTF16 is not used internally.
2667   */
2668   enc2 = enc;
2669   testcase( enc2==SQLITE_UTF16 );
2670   testcase( enc2==SQLITE_UTF16_ALIGNED );
2671   if( enc2==SQLITE_UTF16 || enc2==SQLITE_UTF16_ALIGNED ){
2672     enc2 = SQLITE_UTF16NATIVE;
2673   }
2674   if( enc2<SQLITE_UTF8 || enc2>SQLITE_UTF16BE ){
2675     return SQLITE_MISUSE_BKPT;
2676   }
2677 
2678   /* Check if this call is removing or replacing an existing collation
2679   ** sequence. If so, and there are active VMs, return busy. If there
2680   ** are no active VMs, invalidate any pre-compiled statements.
2681   */
2682   pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, 0);
2683   if( pColl && pColl->xCmp ){
2684     if( db->nVdbeActive ){
2685       sqlite3ErrorWithMsg(db, SQLITE_BUSY,
2686         "unable to delete/modify collation sequence due to active statements");
2687       return SQLITE_BUSY;
2688     }
2689     sqlite3ExpirePreparedStatements(db, 0);
2690 
2691     /* If collation sequence pColl was created directly by a call to
2692     ** sqlite3_create_collation, and not generated by synthCollSeq(),
2693     ** then any copies made by synthCollSeq() need to be invalidated.
2694     ** Also, collation destructor - CollSeq.xDel() - function may need
2695     ** to be called.
2696     */
2697     if( (pColl->enc & ~SQLITE_UTF16_ALIGNED)==enc2 ){
2698       CollSeq *aColl = sqlite3HashFind(&db->aCollSeq, zName);
2699       int j;
2700       for(j=0; j<3; j++){
2701         CollSeq *p = &aColl[j];
2702         if( p->enc==pColl->enc ){
2703           if( p->xDel ){
2704             p->xDel(p->pUser);
2705           }
2706           p->xCmp = 0;
2707         }
2708       }
2709     }
2710   }
2711 
2712   pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, 1);
2713   if( pColl==0 ) return SQLITE_NOMEM_BKPT;
2714   pColl->xCmp = xCompare;
2715   pColl->pUser = pCtx;
2716   pColl->xDel = xDel;
2717   pColl->enc = (u8)(enc2 | (enc & SQLITE_UTF16_ALIGNED));
2718   sqlite3Error(db, SQLITE_OK);
2719   return SQLITE_OK;
2720 }
2721 
2722 
2723 /*
2724 ** This array defines hard upper bounds on limit values.  The
2725 ** initializer must be kept in sync with the SQLITE_LIMIT_*
2726 ** #defines in sqlite3.h.
2727 */
2728 static const int aHardLimit[] = {
2729   SQLITE_MAX_LENGTH,
2730   SQLITE_MAX_SQL_LENGTH,
2731   SQLITE_MAX_COLUMN,
2732   SQLITE_MAX_EXPR_DEPTH,
2733   SQLITE_MAX_COMPOUND_SELECT,
2734   SQLITE_MAX_VDBE_OP,
2735   SQLITE_MAX_FUNCTION_ARG,
2736   SQLITE_MAX_ATTACHED,
2737   SQLITE_MAX_LIKE_PATTERN_LENGTH,
2738   SQLITE_MAX_VARIABLE_NUMBER,      /* IMP: R-38091-32352 */
2739   SQLITE_MAX_TRIGGER_DEPTH,
2740   SQLITE_MAX_WORKER_THREADS,
2741 };
2742 
2743 /*
2744 ** Make sure the hard limits are set to reasonable values
2745 */
2746 #if SQLITE_MAX_LENGTH<100
2747 # error SQLITE_MAX_LENGTH must be at least 100
2748 #endif
2749 #if SQLITE_MAX_SQL_LENGTH<100
2750 # error SQLITE_MAX_SQL_LENGTH must be at least 100
2751 #endif
2752 #if SQLITE_MAX_SQL_LENGTH>SQLITE_MAX_LENGTH
2753 # error SQLITE_MAX_SQL_LENGTH must not be greater than SQLITE_MAX_LENGTH
2754 #endif
2755 #if SQLITE_MAX_COMPOUND_SELECT<2
2756 # error SQLITE_MAX_COMPOUND_SELECT must be at least 2
2757 #endif
2758 #if SQLITE_MAX_VDBE_OP<40
2759 # error SQLITE_MAX_VDBE_OP must be at least 40
2760 #endif
2761 #if SQLITE_MAX_FUNCTION_ARG<0 || SQLITE_MAX_FUNCTION_ARG>127
2762 # error SQLITE_MAX_FUNCTION_ARG must be between 0 and 127
2763 #endif
2764 #if SQLITE_MAX_ATTACHED<0 || SQLITE_MAX_ATTACHED>125
2765 # error SQLITE_MAX_ATTACHED must be between 0 and 125
2766 #endif
2767 #if SQLITE_MAX_LIKE_PATTERN_LENGTH<1
2768 # error SQLITE_MAX_LIKE_PATTERN_LENGTH must be at least 1
2769 #endif
2770 #if SQLITE_MAX_COLUMN>32767
2771 # error SQLITE_MAX_COLUMN must not exceed 32767
2772 #endif
2773 #if SQLITE_MAX_TRIGGER_DEPTH<1
2774 # error SQLITE_MAX_TRIGGER_DEPTH must be at least 1
2775 #endif
2776 #if SQLITE_MAX_WORKER_THREADS<0 || SQLITE_MAX_WORKER_THREADS>50
2777 # error SQLITE_MAX_WORKER_THREADS must be between 0 and 50
2778 #endif
2779 
2780 
2781 /*
2782 ** Change the value of a limit.  Report the old value.
2783 ** If an invalid limit index is supplied, report -1.
2784 ** Make no changes but still report the old value if the
2785 ** new limit is negative.
2786 **
2787 ** A new lower limit does not shrink existing constructs.
2788 ** It merely prevents new constructs that exceed the limit
2789 ** from forming.
2790 */
2791 int sqlite3_limit(sqlite3 *db, int limitId, int newLimit){
2792   int oldLimit;
2793 
2794 #ifdef SQLITE_ENABLE_API_ARMOR
2795   if( !sqlite3SafetyCheckOk(db) ){
2796     (void)SQLITE_MISUSE_BKPT;
2797     return -1;
2798   }
2799 #endif
2800 
2801   /* EVIDENCE-OF: R-30189-54097 For each limit category SQLITE_LIMIT_NAME
2802   ** there is a hard upper bound set at compile-time by a C preprocessor
2803   ** macro called SQLITE_MAX_NAME. (The "_LIMIT_" in the name is changed to
2804   ** "_MAX_".)
2805   */
2806   assert( aHardLimit[SQLITE_LIMIT_LENGTH]==SQLITE_MAX_LENGTH );
2807   assert( aHardLimit[SQLITE_LIMIT_SQL_LENGTH]==SQLITE_MAX_SQL_LENGTH );
2808   assert( aHardLimit[SQLITE_LIMIT_COLUMN]==SQLITE_MAX_COLUMN );
2809   assert( aHardLimit[SQLITE_LIMIT_EXPR_DEPTH]==SQLITE_MAX_EXPR_DEPTH );
2810   assert( aHardLimit[SQLITE_LIMIT_COMPOUND_SELECT]==SQLITE_MAX_COMPOUND_SELECT);
2811   assert( aHardLimit[SQLITE_LIMIT_VDBE_OP]==SQLITE_MAX_VDBE_OP );
2812   assert( aHardLimit[SQLITE_LIMIT_FUNCTION_ARG]==SQLITE_MAX_FUNCTION_ARG );
2813   assert( aHardLimit[SQLITE_LIMIT_ATTACHED]==SQLITE_MAX_ATTACHED );
2814   assert( aHardLimit[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]==
2815                                                SQLITE_MAX_LIKE_PATTERN_LENGTH );
2816   assert( aHardLimit[SQLITE_LIMIT_VARIABLE_NUMBER]==SQLITE_MAX_VARIABLE_NUMBER);
2817   assert( aHardLimit[SQLITE_LIMIT_TRIGGER_DEPTH]==SQLITE_MAX_TRIGGER_DEPTH );
2818   assert( aHardLimit[SQLITE_LIMIT_WORKER_THREADS]==SQLITE_MAX_WORKER_THREADS );
2819   assert( SQLITE_LIMIT_WORKER_THREADS==(SQLITE_N_LIMIT-1) );
2820 
2821 
2822   if( limitId<0 || limitId>=SQLITE_N_LIMIT ){
2823     return -1;
2824   }
2825   oldLimit = db->aLimit[limitId];
2826   if( newLimit>=0 ){                   /* IMP: R-52476-28732 */
2827     if( newLimit>aHardLimit[limitId] ){
2828       newLimit = aHardLimit[limitId];  /* IMP: R-51463-25634 */
2829     }
2830     db->aLimit[limitId] = newLimit;
2831   }
2832   return oldLimit;                     /* IMP: R-53341-35419 */
2833 }
2834 
2835 /*
2836 ** This function is used to parse both URIs and non-URI filenames passed by the
2837 ** user to API functions sqlite3_open() or sqlite3_open_v2(), and for database
2838 ** URIs specified as part of ATTACH statements.
2839 **
2840 ** The first argument to this function is the name of the VFS to use (or
2841 ** a NULL to signify the default VFS) if the URI does not contain a "vfs=xxx"
2842 ** query parameter. The second argument contains the URI (or non-URI filename)
2843 ** itself. When this function is called the *pFlags variable should contain
2844 ** the default flags to open the database handle with. The value stored in
2845 ** *pFlags may be updated before returning if the URI filename contains
2846 ** "cache=xxx" or "mode=xxx" query parameters.
2847 **
2848 ** If successful, SQLITE_OK is returned. In this case *ppVfs is set to point to
2849 ** the VFS that should be used to open the database file. *pzFile is set to
2850 ** point to a buffer containing the name of the file to open.  The value
2851 ** stored in *pzFile is a database name acceptable to sqlite3_uri_parameter()
2852 ** and is in the same format as names created using sqlite3_create_filename().
2853 ** The caller must invoke sqlite3_free_filename() (not sqlite3_free()!) on
2854 ** the value returned in *pzFile to avoid a memory leak.
2855 **
2856 ** If an error occurs, then an SQLite error code is returned and *pzErrMsg
2857 ** may be set to point to a buffer containing an English language error
2858 ** message. It is the responsibility of the caller to eventually release
2859 ** this buffer by calling sqlite3_free().
2860 */
2861 int sqlite3ParseUri(
2862   const char *zDefaultVfs,        /* VFS to use if no "vfs=xxx" query option */
2863   const char *zUri,               /* Nul-terminated URI to parse */
2864   unsigned int *pFlags,           /* IN/OUT: SQLITE_OPEN_XXX flags */
2865   sqlite3_vfs **ppVfs,            /* OUT: VFS to use */
2866   char **pzFile,                  /* OUT: Filename component of URI */
2867   char **pzErrMsg                 /* OUT: Error message (if rc!=SQLITE_OK) */
2868 ){
2869   int rc = SQLITE_OK;
2870   unsigned int flags = *pFlags;
2871   const char *zVfs = zDefaultVfs;
2872   char *zFile;
2873   char c;
2874   int nUri = sqlite3Strlen30(zUri);
2875 
2876   assert( *pzErrMsg==0 );
2877 
2878   if( ((flags & SQLITE_OPEN_URI)             /* IMP: R-48725-32206 */
2879             || sqlite3GlobalConfig.bOpenUri) /* IMP: R-51689-46548 */
2880    && nUri>=5 && memcmp(zUri, "file:", 5)==0 /* IMP: R-57884-37496 */
2881   ){
2882     char *zOpt;
2883     int eState;                   /* Parser state when parsing URI */
2884     int iIn;                      /* Input character index */
2885     int iOut = 0;                 /* Output character index */
2886     u64 nByte = nUri+8;           /* Bytes of space to allocate */
2887 
2888     /* Make sure the SQLITE_OPEN_URI flag is set to indicate to the VFS xOpen
2889     ** method that there may be extra parameters following the file-name.  */
2890     flags |= SQLITE_OPEN_URI;
2891 
2892     for(iIn=0; iIn<nUri; iIn++) nByte += (zUri[iIn]=='&');
2893     zFile = sqlite3_malloc64(nByte);
2894     if( !zFile ) return SQLITE_NOMEM_BKPT;
2895 
2896     memset(zFile, 0, 4);  /* 4-byte of 0x00 is the start of DB name marker */
2897     zFile += 4;
2898 
2899     iIn = 5;
2900 #ifdef SQLITE_ALLOW_URI_AUTHORITY
2901     if( strncmp(zUri+5, "///", 3)==0 ){
2902       iIn = 7;
2903       /* The following condition causes URIs with five leading / characters
2904       ** like file://///host/path to be converted into UNCs like //host/path.
2905       ** The correct URI for that UNC has only two or four leading / characters
2906       ** file://host/path or file:////host/path.  But 5 leading slashes is a
2907       ** common error, we are told, so we handle it as a special case. */
2908       if( strncmp(zUri+7, "///", 3)==0 ){ iIn++; }
2909     }else if( strncmp(zUri+5, "//localhost/", 12)==0 ){
2910       iIn = 16;
2911     }
2912 #else
2913     /* Discard the scheme and authority segments of the URI. */
2914     if( zUri[5]=='/' && zUri[6]=='/' ){
2915       iIn = 7;
2916       while( zUri[iIn] && zUri[iIn]!='/' ) iIn++;
2917       if( iIn!=7 && (iIn!=16 || memcmp("localhost", &zUri[7], 9)) ){
2918         *pzErrMsg = sqlite3_mprintf("invalid uri authority: %.*s",
2919             iIn-7, &zUri[7]);
2920         rc = SQLITE_ERROR;
2921         goto parse_uri_out;
2922       }
2923     }
2924 #endif
2925 
2926     /* Copy the filename and any query parameters into the zFile buffer.
2927     ** Decode %HH escape codes along the way.
2928     **
2929     ** Within this loop, variable eState may be set to 0, 1 or 2, depending
2930     ** on the parsing context. As follows:
2931     **
2932     **   0: Parsing file-name.
2933     **   1: Parsing name section of a name=value query parameter.
2934     **   2: Parsing value section of a name=value query parameter.
2935     */
2936     eState = 0;
2937     while( (c = zUri[iIn])!=0 && c!='#' ){
2938       iIn++;
2939       if( c=='%'
2940        && sqlite3Isxdigit(zUri[iIn])
2941        && sqlite3Isxdigit(zUri[iIn+1])
2942       ){
2943         int octet = (sqlite3HexToInt(zUri[iIn++]) << 4);
2944         octet += sqlite3HexToInt(zUri[iIn++]);
2945 
2946         assert( octet>=0 && octet<256 );
2947         if( octet==0 ){
2948 #ifndef SQLITE_ENABLE_URI_00_ERROR
2949           /* This branch is taken when "%00" appears within the URI. In this
2950           ** case we ignore all text in the remainder of the path, name or
2951           ** value currently being parsed. So ignore the current character
2952           ** and skip to the next "?", "=" or "&", as appropriate. */
2953           while( (c = zUri[iIn])!=0 && c!='#'
2954               && (eState!=0 || c!='?')
2955               && (eState!=1 || (c!='=' && c!='&'))
2956               && (eState!=2 || c!='&')
2957           ){
2958             iIn++;
2959           }
2960           continue;
2961 #else
2962           /* If ENABLE_URI_00_ERROR is defined, "%00" in a URI is an error. */
2963           *pzErrMsg = sqlite3_mprintf("unexpected %%00 in uri");
2964           rc = SQLITE_ERROR;
2965           goto parse_uri_out;
2966 #endif
2967         }
2968         c = octet;
2969       }else if( eState==1 && (c=='&' || c=='=') ){
2970         if( zFile[iOut-1]==0 ){
2971           /* An empty option name. Ignore this option altogether. */
2972           while( zUri[iIn] && zUri[iIn]!='#' && zUri[iIn-1]!='&' ) iIn++;
2973           continue;
2974         }
2975         if( c=='&' ){
2976           zFile[iOut++] = '\0';
2977         }else{
2978           eState = 2;
2979         }
2980         c = 0;
2981       }else if( (eState==0 && c=='?') || (eState==2 && c=='&') ){
2982         c = 0;
2983         eState = 1;
2984       }
2985       zFile[iOut++] = c;
2986     }
2987     if( eState==1 ) zFile[iOut++] = '\0';
2988     memset(zFile+iOut, 0, 4); /* end-of-options + empty journal filenames */
2989 
2990     /* Check if there were any options specified that should be interpreted
2991     ** here. Options that are interpreted here include "vfs" and those that
2992     ** correspond to flags that may be passed to the sqlite3_open_v2()
2993     ** method. */
2994     zOpt = &zFile[sqlite3Strlen30(zFile)+1];
2995     while( zOpt[0] ){
2996       int nOpt = sqlite3Strlen30(zOpt);
2997       char *zVal = &zOpt[nOpt+1];
2998       int nVal = sqlite3Strlen30(zVal);
2999 
3000       if( nOpt==3 && memcmp("vfs", zOpt, 3)==0 ){
3001         zVfs = zVal;
3002       }else{
3003         struct OpenMode {
3004           const char *z;
3005           int mode;
3006         } *aMode = 0;
3007         char *zModeType = 0;
3008         int mask = 0;
3009         int limit = 0;
3010 
3011         if( nOpt==5 && memcmp("cache", zOpt, 5)==0 ){
3012           static struct OpenMode aCacheMode[] = {
3013             { "shared",  SQLITE_OPEN_SHAREDCACHE },
3014             { "private", SQLITE_OPEN_PRIVATECACHE },
3015             { 0, 0 }
3016           };
3017 
3018           mask = SQLITE_OPEN_SHAREDCACHE|SQLITE_OPEN_PRIVATECACHE;
3019           aMode = aCacheMode;
3020           limit = mask;
3021           zModeType = "cache";
3022         }
3023         if( nOpt==4 && memcmp("mode", zOpt, 4)==0 ){
3024           static struct OpenMode aOpenMode[] = {
3025             { "ro",  SQLITE_OPEN_READONLY },
3026             { "rw",  SQLITE_OPEN_READWRITE },
3027             { "rwc", SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE },
3028             { "memory", SQLITE_OPEN_MEMORY },
3029             { 0, 0 }
3030           };
3031 
3032           mask = SQLITE_OPEN_READONLY | SQLITE_OPEN_READWRITE
3033                    | SQLITE_OPEN_CREATE | SQLITE_OPEN_MEMORY;
3034           aMode = aOpenMode;
3035           limit = mask & flags;
3036           zModeType = "access";
3037         }
3038 
3039         if( aMode ){
3040           int i;
3041           int mode = 0;
3042           for(i=0; aMode[i].z; i++){
3043             const char *z = aMode[i].z;
3044             if( nVal==sqlite3Strlen30(z) && 0==memcmp(zVal, z, nVal) ){
3045               mode = aMode[i].mode;
3046               break;
3047             }
3048           }
3049           if( mode==0 ){
3050             *pzErrMsg = sqlite3_mprintf("no such %s mode: %s", zModeType, zVal);
3051             rc = SQLITE_ERROR;
3052             goto parse_uri_out;
3053           }
3054           if( (mode & ~SQLITE_OPEN_MEMORY)>limit ){
3055             *pzErrMsg = sqlite3_mprintf("%s mode not allowed: %s",
3056                                         zModeType, zVal);
3057             rc = SQLITE_PERM;
3058             goto parse_uri_out;
3059           }
3060           flags = (flags & ~mask) | mode;
3061         }
3062       }
3063 
3064       zOpt = &zVal[nVal+1];
3065     }
3066 
3067   }else{
3068     zFile = sqlite3_malloc64(nUri+8);
3069     if( !zFile ) return SQLITE_NOMEM_BKPT;
3070     memset(zFile, 0, 4);
3071     zFile += 4;
3072     if( nUri ){
3073       memcpy(zFile, zUri, nUri);
3074     }
3075     memset(zFile+nUri, 0, 4);
3076     flags &= ~SQLITE_OPEN_URI;
3077   }
3078 
3079   *ppVfs = sqlite3_vfs_find(zVfs);
3080   if( *ppVfs==0 ){
3081     *pzErrMsg = sqlite3_mprintf("no such vfs: %s", zVfs);
3082     rc = SQLITE_ERROR;
3083   }
3084  parse_uri_out:
3085   if( rc!=SQLITE_OK ){
3086     sqlite3_free_filename(zFile);
3087     zFile = 0;
3088   }
3089   *pFlags = flags;
3090   *pzFile = zFile;
3091   return rc;
3092 }
3093 
3094 /*
3095 ** This routine does the core work of extracting URI parameters from a
3096 ** database filename for the sqlite3_uri_parameter() interface.
3097 */
3098 static const char *uriParameter(const char *zFilename, const char *zParam){
3099   zFilename += sqlite3Strlen30(zFilename) + 1;
3100   while( ALWAYS(zFilename!=0) && zFilename[0] ){
3101     int x = strcmp(zFilename, zParam);
3102     zFilename += sqlite3Strlen30(zFilename) + 1;
3103     if( x==0 ) return zFilename;
3104     zFilename += sqlite3Strlen30(zFilename) + 1;
3105   }
3106   return 0;
3107 }
3108 
3109 
3110 
3111 /*
3112 ** This routine does the work of opening a database on behalf of
3113 ** sqlite3_open() and sqlite3_open16(). The database filename "zFilename"
3114 ** is UTF-8 encoded.
3115 */
3116 static int openDatabase(
3117   const char *zFilename, /* Database filename UTF-8 encoded */
3118   sqlite3 **ppDb,        /* OUT: Returned database handle */
3119   unsigned int flags,    /* Operational flags */
3120   const char *zVfs       /* Name of the VFS to use */
3121 ){
3122   sqlite3 *db;                    /* Store allocated handle here */
3123   int rc;                         /* Return code */
3124   int isThreadsafe;               /* True for threadsafe connections */
3125   char *zOpen = 0;                /* Filename argument to pass to BtreeOpen() */
3126   char *zErrMsg = 0;              /* Error message from sqlite3ParseUri() */
3127   int i;                          /* Loop counter */
3128 
3129 #ifdef SQLITE_ENABLE_API_ARMOR
3130   if( ppDb==0 ) return SQLITE_MISUSE_BKPT;
3131 #endif
3132   *ppDb = 0;
3133 #ifndef SQLITE_OMIT_AUTOINIT
3134   rc = sqlite3_initialize();
3135   if( rc ) return rc;
3136 #endif
3137 
3138   if( sqlite3GlobalConfig.bCoreMutex==0 ){
3139     isThreadsafe = 0;
3140   }else if( flags & SQLITE_OPEN_NOMUTEX ){
3141     isThreadsafe = 0;
3142   }else if( flags & SQLITE_OPEN_FULLMUTEX ){
3143     isThreadsafe = 1;
3144   }else{
3145     isThreadsafe = sqlite3GlobalConfig.bFullMutex;
3146   }
3147 
3148   if( flags & SQLITE_OPEN_PRIVATECACHE ){
3149     flags &= ~SQLITE_OPEN_SHAREDCACHE;
3150   }else if( sqlite3GlobalConfig.sharedCacheEnabled ){
3151     flags |= SQLITE_OPEN_SHAREDCACHE;
3152   }
3153 
3154   /* Remove harmful bits from the flags parameter
3155   **
3156   ** The SQLITE_OPEN_NOMUTEX and SQLITE_OPEN_FULLMUTEX flags were
3157   ** dealt with in the previous code block.  Besides these, the only
3158   ** valid input flags for sqlite3_open_v2() are SQLITE_OPEN_READONLY,
3159   ** SQLITE_OPEN_READWRITE, SQLITE_OPEN_CREATE, SQLITE_OPEN_SHAREDCACHE,
3160   ** SQLITE_OPEN_PRIVATECACHE, and some reserved bits.  Silently mask
3161   ** off all other flags.
3162   */
3163   flags &=  ~( SQLITE_OPEN_DELETEONCLOSE |
3164                SQLITE_OPEN_MAIN_DB |
3165                SQLITE_OPEN_TEMP_DB |
3166                SQLITE_OPEN_TRANSIENT_DB |
3167                SQLITE_OPEN_MAIN_JOURNAL |
3168                SQLITE_OPEN_TEMP_JOURNAL |
3169                SQLITE_OPEN_SUBJOURNAL |
3170                SQLITE_OPEN_SUPER_JOURNAL |
3171                SQLITE_OPEN_NOMUTEX |
3172                SQLITE_OPEN_FULLMUTEX |
3173                SQLITE_OPEN_WAL
3174              );
3175 
3176   /* Allocate the sqlite data structure */
3177   db = sqlite3MallocZero( sizeof(sqlite3) );
3178   if( db==0 ) goto opendb_out;
3179   if( isThreadsafe
3180 #ifdef SQLITE_ENABLE_MULTITHREADED_CHECKS
3181    || sqlite3GlobalConfig.bCoreMutex
3182 #endif
3183   ){
3184     db->mutex = sqlite3MutexAlloc(SQLITE_MUTEX_RECURSIVE);
3185     if( db->mutex==0 ){
3186       sqlite3_free(db);
3187       db = 0;
3188       goto opendb_out;
3189     }
3190     if( isThreadsafe==0 ){
3191       sqlite3MutexWarnOnContention(db->mutex);
3192     }
3193   }
3194   sqlite3_mutex_enter(db->mutex);
3195   db->errMask = 0xff;
3196   db->nDb = 2;
3197   db->eOpenState = SQLITE_STATE_BUSY;
3198   db->aDb = db->aDbStatic;
3199   db->lookaside.bDisable = 1;
3200   db->lookaside.sz = 0;
3201 
3202   assert( sizeof(db->aLimit)==sizeof(aHardLimit) );
3203   memcpy(db->aLimit, aHardLimit, sizeof(db->aLimit));
3204   db->aLimit[SQLITE_LIMIT_WORKER_THREADS] = SQLITE_DEFAULT_WORKER_THREADS;
3205   db->autoCommit = 1;
3206   db->nextAutovac = -1;
3207   db->szMmap = sqlite3GlobalConfig.szMmap;
3208   db->nextPagesize = 0;
3209   db->init.azInit = sqlite3StdType; /* Any array of string ptrs will do */
3210 #ifdef SQLITE_ENABLE_SORTER_MMAP
3211   /* Beginning with version 3.37.0, using the VFS xFetch() API to memory-map
3212   ** the temporary files used to do external sorts (see code in vdbesort.c)
3213   ** is disabled. It can still be used either by defining
3214   ** SQLITE_ENABLE_SORTER_MMAP at compile time or by using the
3215   ** SQLITE_TESTCTRL_SORTER_MMAP test-control at runtime. */
3216   db->nMaxSorterMmap = 0x7FFFFFFF;
3217 #endif
3218   db->flags |= SQLITE_ShortColNames
3219                  | SQLITE_EnableTrigger
3220                  | SQLITE_EnableView
3221                  | SQLITE_CacheSpill
3222 #if !defined(SQLITE_TRUSTED_SCHEMA) || SQLITE_TRUSTED_SCHEMA+0!=0
3223                  | SQLITE_TrustedSchema
3224 #endif
3225 /* The SQLITE_DQS compile-time option determines the default settings
3226 ** for SQLITE_DBCONFIG_DQS_DDL and SQLITE_DBCONFIG_DQS_DML.
3227 **
3228 **    SQLITE_DQS     SQLITE_DBCONFIG_DQS_DDL    SQLITE_DBCONFIG_DQS_DML
3229 **    ----------     -----------------------    -----------------------
3230 **     undefined               on                          on
3231 **         3                   on                          on
3232 **         2                   on                         off
3233 **         1                  off                          on
3234 **         0                  off                         off
3235 **
3236 ** Legacy behavior is 3 (double-quoted string literals are allowed anywhere)
3237 ** and so that is the default.  But developers are encouranged to use
3238 ** -DSQLITE_DQS=0 (best) or -DSQLITE_DQS=1 (second choice) if possible.
3239 */
3240 #if !defined(SQLITE_DQS)
3241 # define SQLITE_DQS 3
3242 #endif
3243 #if (SQLITE_DQS&1)==1
3244                  | SQLITE_DqsDML
3245 #endif
3246 #if (SQLITE_DQS&2)==2
3247                  | SQLITE_DqsDDL
3248 #endif
3249 
3250 #if !defined(SQLITE_DEFAULT_AUTOMATIC_INDEX) || SQLITE_DEFAULT_AUTOMATIC_INDEX
3251                  | SQLITE_AutoIndex
3252 #endif
3253 #if SQLITE_DEFAULT_CKPTFULLFSYNC
3254                  | SQLITE_CkptFullFSync
3255 #endif
3256 #if SQLITE_DEFAULT_FILE_FORMAT<4
3257                  | SQLITE_LegacyFileFmt
3258 #endif
3259 #ifdef SQLITE_ENABLE_LOAD_EXTENSION
3260                  | SQLITE_LoadExtension
3261 #endif
3262 #if SQLITE_DEFAULT_RECURSIVE_TRIGGERS
3263                  | SQLITE_RecTriggers
3264 #endif
3265 #if defined(SQLITE_DEFAULT_FOREIGN_KEYS) && SQLITE_DEFAULT_FOREIGN_KEYS
3266                  | SQLITE_ForeignKeys
3267 #endif
3268 #if defined(SQLITE_REVERSE_UNORDERED_SELECTS)
3269                  | SQLITE_ReverseOrder
3270 #endif
3271 #if defined(SQLITE_ENABLE_OVERSIZE_CELL_CHECK)
3272                  | SQLITE_CellSizeCk
3273 #endif
3274 #if defined(SQLITE_ENABLE_FTS3_TOKENIZER)
3275                  | SQLITE_Fts3Tokenizer
3276 #endif
3277 #if defined(SQLITE_ENABLE_QPSG)
3278                  | SQLITE_EnableQPSG
3279 #endif
3280 #if defined(SQLITE_DEFAULT_DEFENSIVE)
3281                  | SQLITE_Defensive
3282 #endif
3283 #if defined(SQLITE_DEFAULT_LEGACY_ALTER_TABLE)
3284                  | SQLITE_LegacyAlter
3285 #endif
3286       ;
3287   sqlite3HashInit(&db->aCollSeq);
3288 #ifndef SQLITE_OMIT_VIRTUALTABLE
3289   sqlite3HashInit(&db->aModule);
3290 #endif
3291 
3292   /* Add the default collation sequence BINARY. BINARY works for both UTF-8
3293   ** and UTF-16, so add a version for each to avoid any unnecessary
3294   ** conversions. The only error that can occur here is a malloc() failure.
3295   **
3296   ** EVIDENCE-OF: R-52786-44878 SQLite defines three built-in collating
3297   ** functions:
3298   */
3299   createCollation(db, sqlite3StrBINARY, SQLITE_UTF8, 0, binCollFunc, 0);
3300   createCollation(db, sqlite3StrBINARY, SQLITE_UTF16BE, 0, binCollFunc, 0);
3301   createCollation(db, sqlite3StrBINARY, SQLITE_UTF16LE, 0, binCollFunc, 0);
3302   createCollation(db, "NOCASE", SQLITE_UTF8, 0, nocaseCollatingFunc, 0);
3303   createCollation(db, "RTRIM", SQLITE_UTF8, 0, rtrimCollFunc, 0);
3304   if( db->mallocFailed ){
3305     goto opendb_out;
3306   }
3307 
3308   /* Parse the filename/URI argument
3309   **
3310   ** Only allow sensible combinations of bits in the flags argument.
3311   ** Throw an error if any non-sense combination is used.  If we
3312   ** do not block illegal combinations here, it could trigger
3313   ** assert() statements in deeper layers.  Sensible combinations
3314   ** are:
3315   **
3316   **  1:  SQLITE_OPEN_READONLY
3317   **  2:  SQLITE_OPEN_READWRITE
3318   **  6:  SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE
3319   */
3320   db->openFlags = flags;
3321   assert( SQLITE_OPEN_READONLY  == 0x01 );
3322   assert( SQLITE_OPEN_READWRITE == 0x02 );
3323   assert( SQLITE_OPEN_CREATE    == 0x04 );
3324   testcase( (1<<(flags&7))==0x02 ); /* READONLY */
3325   testcase( (1<<(flags&7))==0x04 ); /* READWRITE */
3326   testcase( (1<<(flags&7))==0x40 ); /* READWRITE | CREATE */
3327   if( ((1<<(flags&7)) & 0x46)==0 ){
3328     rc = SQLITE_MISUSE_BKPT;  /* IMP: R-18321-05872 */
3329   }else{
3330     rc = sqlite3ParseUri(zVfs, zFilename, &flags, &db->pVfs, &zOpen, &zErrMsg);
3331   }
3332   if( rc!=SQLITE_OK ){
3333     if( rc==SQLITE_NOMEM ) sqlite3OomFault(db);
3334     sqlite3ErrorWithMsg(db, rc, zErrMsg ? "%s" : 0, zErrMsg);
3335     sqlite3_free(zErrMsg);
3336     goto opendb_out;
3337   }
3338 
3339   /* Open the backend database driver */
3340   rc = sqlite3BtreeOpen(db->pVfs, zOpen, db, &db->aDb[0].pBt, 0,
3341                         flags | SQLITE_OPEN_MAIN_DB);
3342   if( rc!=SQLITE_OK ){
3343     if( rc==SQLITE_IOERR_NOMEM ){
3344       rc = SQLITE_NOMEM_BKPT;
3345     }
3346     sqlite3Error(db, rc);
3347     goto opendb_out;
3348   }
3349   sqlite3BtreeEnter(db->aDb[0].pBt);
3350   db->aDb[0].pSchema = sqlite3SchemaGet(db, db->aDb[0].pBt);
3351   if( !db->mallocFailed ){
3352     sqlite3SetTextEncoding(db, SCHEMA_ENC(db));
3353   }
3354   sqlite3BtreeLeave(db->aDb[0].pBt);
3355   db->aDb[1].pSchema = sqlite3SchemaGet(db, 0);
3356 
3357   /* The default safety_level for the main database is FULL; for the temp
3358   ** database it is OFF. This matches the pager layer defaults.
3359   */
3360   db->aDb[0].zDbSName = "main";
3361   db->aDb[0].safety_level = SQLITE_DEFAULT_SYNCHRONOUS+1;
3362   db->aDb[1].zDbSName = "temp";
3363   db->aDb[1].safety_level = PAGER_SYNCHRONOUS_OFF;
3364 
3365   db->eOpenState = SQLITE_STATE_OPEN;
3366   if( db->mallocFailed ){
3367     goto opendb_out;
3368   }
3369 
3370   /* Register all built-in functions, but do not attempt to read the
3371   ** database schema yet. This is delayed until the first time the database
3372   ** is accessed.
3373   */
3374   sqlite3Error(db, SQLITE_OK);
3375   sqlite3RegisterPerConnectionBuiltinFunctions(db);
3376   rc = sqlite3_errcode(db);
3377 
3378 
3379   /* Load compiled-in extensions */
3380   for(i=0; rc==SQLITE_OK && i<ArraySize(sqlite3BuiltinExtensions); i++){
3381     rc = sqlite3BuiltinExtensions[i](db);
3382   }
3383 
3384   /* Load automatic extensions - extensions that have been registered
3385   ** using the sqlite3_automatic_extension() API.
3386   */
3387   if( rc==SQLITE_OK ){
3388     sqlite3AutoLoadExtensions(db);
3389     rc = sqlite3_errcode(db);
3390     if( rc!=SQLITE_OK ){
3391       goto opendb_out;
3392     }
3393   }
3394 
3395 #ifdef SQLITE_ENABLE_INTERNAL_FUNCTIONS
3396   /* Testing use only!!! The -DSQLITE_ENABLE_INTERNAL_FUNCTIONS=1 compile-time
3397   ** option gives access to internal functions by default.
3398   ** Testing use only!!! */
3399   db->mDbFlags |= DBFLAG_InternalFunc;
3400 #endif
3401 
3402   /* -DSQLITE_DEFAULT_LOCKING_MODE=1 makes EXCLUSIVE the default locking
3403   ** mode.  -DSQLITE_DEFAULT_LOCKING_MODE=0 make NORMAL the default locking
3404   ** mode.  Doing nothing at all also makes NORMAL the default.
3405   */
3406 #ifdef SQLITE_DEFAULT_LOCKING_MODE
3407   db->dfltLockMode = SQLITE_DEFAULT_LOCKING_MODE;
3408   sqlite3PagerLockingMode(sqlite3BtreePager(db->aDb[0].pBt),
3409                           SQLITE_DEFAULT_LOCKING_MODE);
3410 #endif
3411 
3412   if( rc ) sqlite3Error(db, rc);
3413 
3414   /* Enable the lookaside-malloc subsystem */
3415   setupLookaside(db, 0, sqlite3GlobalConfig.szLookaside,
3416                         sqlite3GlobalConfig.nLookaside);
3417 
3418   sqlite3_wal_autocheckpoint(db, SQLITE_DEFAULT_WAL_AUTOCHECKPOINT);
3419 
3420 opendb_out:
3421   if( db ){
3422     assert( db->mutex!=0 || isThreadsafe==0
3423            || sqlite3GlobalConfig.bFullMutex==0 );
3424     sqlite3_mutex_leave(db->mutex);
3425   }
3426   rc = sqlite3_errcode(db);
3427   assert( db!=0 || rc==SQLITE_NOMEM );
3428   if( rc==SQLITE_NOMEM ){
3429     sqlite3_close(db);
3430     db = 0;
3431   }else if( rc!=SQLITE_OK ){
3432     db->eOpenState = SQLITE_STATE_SICK;
3433   }
3434   *ppDb = db;
3435 #ifdef SQLITE_ENABLE_SQLLOG
3436   if( sqlite3GlobalConfig.xSqllog ){
3437     /* Opening a db handle. Fourth parameter is passed 0. */
3438     void *pArg = sqlite3GlobalConfig.pSqllogArg;
3439     sqlite3GlobalConfig.xSqllog(pArg, db, zFilename, 0);
3440   }
3441 #endif
3442   sqlite3_free_filename(zOpen);
3443   return rc & 0xff;
3444 }
3445 
3446 
3447 /*
3448 ** Open a new database handle.
3449 */
3450 int sqlite3_open(
3451   const char *zFilename,
3452   sqlite3 **ppDb
3453 ){
3454   return openDatabase(zFilename, ppDb,
3455                       SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
3456 }
3457 int sqlite3_open_v2(
3458   const char *filename,   /* Database filename (UTF-8) */
3459   sqlite3 **ppDb,         /* OUT: SQLite db handle */
3460   int flags,              /* Flags */
3461   const char *zVfs        /* Name of VFS module to use */
3462 ){
3463   return openDatabase(filename, ppDb, (unsigned int)flags, zVfs);
3464 }
3465 
3466 #ifndef SQLITE_OMIT_UTF16
3467 /*
3468 ** Open a new database handle.
3469 */
3470 int sqlite3_open16(
3471   const void *zFilename,
3472   sqlite3 **ppDb
3473 ){
3474   char const *zFilename8;   /* zFilename encoded in UTF-8 instead of UTF-16 */
3475   sqlite3_value *pVal;
3476   int rc;
3477 
3478 #ifdef SQLITE_ENABLE_API_ARMOR
3479   if( ppDb==0 ) return SQLITE_MISUSE_BKPT;
3480 #endif
3481   *ppDb = 0;
3482 #ifndef SQLITE_OMIT_AUTOINIT
3483   rc = sqlite3_initialize();
3484   if( rc ) return rc;
3485 #endif
3486   if( zFilename==0 ) zFilename = "\000\000";
3487   pVal = sqlite3ValueNew(0);
3488   sqlite3ValueSetStr(pVal, -1, zFilename, SQLITE_UTF16NATIVE, SQLITE_STATIC);
3489   zFilename8 = sqlite3ValueText(pVal, SQLITE_UTF8);
3490   if( zFilename8 ){
3491     rc = openDatabase(zFilename8, ppDb,
3492                       SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
3493     assert( *ppDb || rc==SQLITE_NOMEM );
3494     if( rc==SQLITE_OK && !DbHasProperty(*ppDb, 0, DB_SchemaLoaded) ){
3495       SCHEMA_ENC(*ppDb) = ENC(*ppDb) = SQLITE_UTF16NATIVE;
3496     }
3497   }else{
3498     rc = SQLITE_NOMEM_BKPT;
3499   }
3500   sqlite3ValueFree(pVal);
3501 
3502   return rc & 0xff;
3503 }
3504 #endif /* SQLITE_OMIT_UTF16 */
3505 
3506 /*
3507 ** Register a new collation sequence with the database handle db.
3508 */
3509 int sqlite3_create_collation(
3510   sqlite3* db,
3511   const char *zName,
3512   int enc,
3513   void* pCtx,
3514   int(*xCompare)(void*,int,const void*,int,const void*)
3515 ){
3516   return sqlite3_create_collation_v2(db, zName, enc, pCtx, xCompare, 0);
3517 }
3518 
3519 /*
3520 ** Register a new collation sequence with the database handle db.
3521 */
3522 int sqlite3_create_collation_v2(
3523   sqlite3* db,
3524   const char *zName,
3525   int enc,
3526   void* pCtx,
3527   int(*xCompare)(void*,int,const void*,int,const void*),
3528   void(*xDel)(void*)
3529 ){
3530   int rc;
3531 
3532 #ifdef SQLITE_ENABLE_API_ARMOR
3533   if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
3534 #endif
3535   sqlite3_mutex_enter(db->mutex);
3536   assert( !db->mallocFailed );
3537   rc = createCollation(db, zName, (u8)enc, pCtx, xCompare, xDel);
3538   rc = sqlite3ApiExit(db, rc);
3539   sqlite3_mutex_leave(db->mutex);
3540   return rc;
3541 }
3542 
3543 #ifndef SQLITE_OMIT_UTF16
3544 /*
3545 ** Register a new collation sequence with the database handle db.
3546 */
3547 int sqlite3_create_collation16(
3548   sqlite3* db,
3549   const void *zName,
3550   int enc,
3551   void* pCtx,
3552   int(*xCompare)(void*,int,const void*,int,const void*)
3553 ){
3554   int rc = SQLITE_OK;
3555   char *zName8;
3556 
3557 #ifdef SQLITE_ENABLE_API_ARMOR
3558   if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
3559 #endif
3560   sqlite3_mutex_enter(db->mutex);
3561   assert( !db->mallocFailed );
3562   zName8 = sqlite3Utf16to8(db, zName, -1, SQLITE_UTF16NATIVE);
3563   if( zName8 ){
3564     rc = createCollation(db, zName8, (u8)enc, pCtx, xCompare, 0);
3565     sqlite3DbFree(db, zName8);
3566   }
3567   rc = sqlite3ApiExit(db, rc);
3568   sqlite3_mutex_leave(db->mutex);
3569   return rc;
3570 }
3571 #endif /* SQLITE_OMIT_UTF16 */
3572 
3573 /*
3574 ** Register a collation sequence factory callback with the database handle
3575 ** db. Replace any previously installed collation sequence factory.
3576 */
3577 int sqlite3_collation_needed(
3578   sqlite3 *db,
3579   void *pCollNeededArg,
3580   void(*xCollNeeded)(void*,sqlite3*,int eTextRep,const char*)
3581 ){
3582 #ifdef SQLITE_ENABLE_API_ARMOR
3583   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3584 #endif
3585   sqlite3_mutex_enter(db->mutex);
3586   db->xCollNeeded = xCollNeeded;
3587   db->xCollNeeded16 = 0;
3588   db->pCollNeededArg = pCollNeededArg;
3589   sqlite3_mutex_leave(db->mutex);
3590   return SQLITE_OK;
3591 }
3592 
3593 #ifndef SQLITE_OMIT_UTF16
3594 /*
3595 ** Register a collation sequence factory callback with the database handle
3596 ** db. Replace any previously installed collation sequence factory.
3597 */
3598 int sqlite3_collation_needed16(
3599   sqlite3 *db,
3600   void *pCollNeededArg,
3601   void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*)
3602 ){
3603 #ifdef SQLITE_ENABLE_API_ARMOR
3604   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3605 #endif
3606   sqlite3_mutex_enter(db->mutex);
3607   db->xCollNeeded = 0;
3608   db->xCollNeeded16 = xCollNeeded16;
3609   db->pCollNeededArg = pCollNeededArg;
3610   sqlite3_mutex_leave(db->mutex);
3611   return SQLITE_OK;
3612 }
3613 #endif /* SQLITE_OMIT_UTF16 */
3614 
3615 #ifndef SQLITE_OMIT_DEPRECATED
3616 /*
3617 ** This function is now an anachronism. It used to be used to recover from a
3618 ** malloc() failure, but SQLite now does this automatically.
3619 */
3620 int sqlite3_global_recover(void){
3621   return SQLITE_OK;
3622 }
3623 #endif
3624 
3625 /*
3626 ** Test to see whether or not the database connection is in autocommit
3627 ** mode.  Return TRUE if it is and FALSE if not.  Autocommit mode is on
3628 ** by default.  Autocommit is disabled by a BEGIN statement and reenabled
3629 ** by the next COMMIT or ROLLBACK.
3630 */
3631 int sqlite3_get_autocommit(sqlite3 *db){
3632 #ifdef SQLITE_ENABLE_API_ARMOR
3633   if( !sqlite3SafetyCheckOk(db) ){
3634     (void)SQLITE_MISUSE_BKPT;
3635     return 0;
3636   }
3637 #endif
3638   return db->autoCommit;
3639 }
3640 
3641 /*
3642 ** The following routines are substitutes for constants SQLITE_CORRUPT,
3643 ** SQLITE_MISUSE, SQLITE_CANTOPEN, SQLITE_NOMEM and possibly other error
3644 ** constants.  They serve two purposes:
3645 **
3646 **   1.  Serve as a convenient place to set a breakpoint in a debugger
3647 **       to detect when version error conditions occurs.
3648 **
3649 **   2.  Invoke sqlite3_log() to provide the source code location where
3650 **       a low-level error is first detected.
3651 */
3652 int sqlite3ReportError(int iErr, int lineno, const char *zType){
3653   sqlite3_log(iErr, "%s at line %d of [%.10s]",
3654               zType, lineno, 20+sqlite3_sourceid());
3655   return iErr;
3656 }
3657 int sqlite3CorruptError(int lineno){
3658   testcase( sqlite3GlobalConfig.xLog!=0 );
3659   return sqlite3ReportError(SQLITE_CORRUPT, lineno, "database corruption");
3660 }
3661 int sqlite3MisuseError(int lineno){
3662   testcase( sqlite3GlobalConfig.xLog!=0 );
3663   return sqlite3ReportError(SQLITE_MISUSE, lineno, "misuse");
3664 }
3665 int sqlite3CantopenError(int lineno){
3666   testcase( sqlite3GlobalConfig.xLog!=0 );
3667   return sqlite3ReportError(SQLITE_CANTOPEN, lineno, "cannot open file");
3668 }
3669 #if defined(SQLITE_DEBUG) || defined(SQLITE_ENABLE_CORRUPT_PGNO)
3670 int sqlite3CorruptPgnoError(int lineno, Pgno pgno){
3671   char zMsg[100];
3672   sqlite3_snprintf(sizeof(zMsg), zMsg, "database corruption page %d", pgno);
3673   testcase( sqlite3GlobalConfig.xLog!=0 );
3674   return sqlite3ReportError(SQLITE_CORRUPT, lineno, zMsg);
3675 }
3676 #endif
3677 #ifdef SQLITE_DEBUG
3678 int sqlite3NomemError(int lineno){
3679   testcase( sqlite3GlobalConfig.xLog!=0 );
3680   return sqlite3ReportError(SQLITE_NOMEM, lineno, "OOM");
3681 }
3682 int sqlite3IoerrnomemError(int lineno){
3683   testcase( sqlite3GlobalConfig.xLog!=0 );
3684   return sqlite3ReportError(SQLITE_IOERR_NOMEM, lineno, "I/O OOM error");
3685 }
3686 #endif
3687 
3688 #ifndef SQLITE_OMIT_DEPRECATED
3689 /*
3690 ** This is a convenience routine that makes sure that all thread-specific
3691 ** data for this thread has been deallocated.
3692 **
3693 ** SQLite no longer uses thread-specific data so this routine is now a
3694 ** no-op.  It is retained for historical compatibility.
3695 */
3696 void sqlite3_thread_cleanup(void){
3697 }
3698 #endif
3699 
3700 /*
3701 ** Return meta information about a specific column of a database table.
3702 ** See comment in sqlite3.h (sqlite.h.in) for details.
3703 */
3704 int sqlite3_table_column_metadata(
3705   sqlite3 *db,                /* Connection handle */
3706   const char *zDbName,        /* Database name or NULL */
3707   const char *zTableName,     /* Table name */
3708   const char *zColumnName,    /* Column name */
3709   char const **pzDataType,    /* OUTPUT: Declared data type */
3710   char const **pzCollSeq,     /* OUTPUT: Collation sequence name */
3711   int *pNotNull,              /* OUTPUT: True if NOT NULL constraint exists */
3712   int *pPrimaryKey,           /* OUTPUT: True if column part of PK */
3713   int *pAutoinc               /* OUTPUT: True if column is auto-increment */
3714 ){
3715   int rc;
3716   char *zErrMsg = 0;
3717   Table *pTab = 0;
3718   Column *pCol = 0;
3719   int iCol = 0;
3720   char const *zDataType = 0;
3721   char const *zCollSeq = 0;
3722   int notnull = 0;
3723   int primarykey = 0;
3724   int autoinc = 0;
3725 
3726 
3727 #ifdef SQLITE_ENABLE_API_ARMOR
3728   if( !sqlite3SafetyCheckOk(db) || zTableName==0 ){
3729     return SQLITE_MISUSE_BKPT;
3730   }
3731 #endif
3732 
3733   /* Ensure the database schema has been loaded */
3734   sqlite3_mutex_enter(db->mutex);
3735   sqlite3BtreeEnterAll(db);
3736   rc = sqlite3Init(db, &zErrMsg);
3737   if( SQLITE_OK!=rc ){
3738     goto error_out;
3739   }
3740 
3741   /* Locate the table in question */
3742   pTab = sqlite3FindTable(db, zTableName, zDbName);
3743   if( !pTab || IsView(pTab) ){
3744     pTab = 0;
3745     goto error_out;
3746   }
3747 
3748   /* Find the column for which info is requested */
3749   if( zColumnName==0 ){
3750     /* Query for existance of table only */
3751   }else{
3752     for(iCol=0; iCol<pTab->nCol; iCol++){
3753       pCol = &pTab->aCol[iCol];
3754       if( 0==sqlite3StrICmp(pCol->zCnName, zColumnName) ){
3755         break;
3756       }
3757     }
3758     if( iCol==pTab->nCol ){
3759       if( HasRowid(pTab) && sqlite3IsRowid(zColumnName) ){
3760         iCol = pTab->iPKey;
3761         pCol = iCol>=0 ? &pTab->aCol[iCol] : 0;
3762       }else{
3763         pTab = 0;
3764         goto error_out;
3765       }
3766     }
3767   }
3768 
3769   /* The following block stores the meta information that will be returned
3770   ** to the caller in local variables zDataType, zCollSeq, notnull, primarykey
3771   ** and autoinc. At this point there are two possibilities:
3772   **
3773   **     1. The specified column name was rowid", "oid" or "_rowid_"
3774   **        and there is no explicitly declared IPK column.
3775   **
3776   **     2. The table is not a view and the column name identified an
3777   **        explicitly declared column. Copy meta information from *pCol.
3778   */
3779   if( pCol ){
3780     zDataType = sqlite3ColumnType(pCol,0);
3781     zCollSeq = sqlite3ColumnColl(pCol);
3782     notnull = pCol->notNull!=0;
3783     primarykey  = (pCol->colFlags & COLFLAG_PRIMKEY)!=0;
3784     autoinc = pTab->iPKey==iCol && (pTab->tabFlags & TF_Autoincrement)!=0;
3785   }else{
3786     zDataType = "INTEGER";
3787     primarykey = 1;
3788   }
3789   if( !zCollSeq ){
3790     zCollSeq = sqlite3StrBINARY;
3791   }
3792 
3793 error_out:
3794   sqlite3BtreeLeaveAll(db);
3795 
3796   /* Whether the function call succeeded or failed, set the output parameters
3797   ** to whatever their local counterparts contain. If an error did occur,
3798   ** this has the effect of zeroing all output parameters.
3799   */
3800   if( pzDataType ) *pzDataType = zDataType;
3801   if( pzCollSeq ) *pzCollSeq = zCollSeq;
3802   if( pNotNull ) *pNotNull = notnull;
3803   if( pPrimaryKey ) *pPrimaryKey = primarykey;
3804   if( pAutoinc ) *pAutoinc = autoinc;
3805 
3806   if( SQLITE_OK==rc && !pTab ){
3807     sqlite3DbFree(db, zErrMsg);
3808     zErrMsg = sqlite3MPrintf(db, "no such table column: %s.%s", zTableName,
3809         zColumnName);
3810     rc = SQLITE_ERROR;
3811   }
3812   sqlite3ErrorWithMsg(db, rc, (zErrMsg?"%s":0), zErrMsg);
3813   sqlite3DbFree(db, zErrMsg);
3814   rc = sqlite3ApiExit(db, rc);
3815   sqlite3_mutex_leave(db->mutex);
3816   return rc;
3817 }
3818 
3819 /*
3820 ** Sleep for a little while.  Return the amount of time slept.
3821 */
3822 int sqlite3_sleep(int ms){
3823   sqlite3_vfs *pVfs;
3824   int rc;
3825   pVfs = sqlite3_vfs_find(0);
3826   if( pVfs==0 ) return 0;
3827 
3828   /* This function works in milliseconds, but the underlying OsSleep()
3829   ** API uses microseconds. Hence the 1000's.
3830   */
3831   rc = (sqlite3OsSleep(pVfs, 1000*ms)/1000);
3832   return rc;
3833 }
3834 
3835 /*
3836 ** Enable or disable the extended result codes.
3837 */
3838 int sqlite3_extended_result_codes(sqlite3 *db, int onoff){
3839 #ifdef SQLITE_ENABLE_API_ARMOR
3840   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3841 #endif
3842   sqlite3_mutex_enter(db->mutex);
3843   db->errMask = onoff ? 0xffffffff : 0xff;
3844   sqlite3_mutex_leave(db->mutex);
3845   return SQLITE_OK;
3846 }
3847 
3848 /*
3849 ** Invoke the xFileControl method on a particular database.
3850 */
3851 int sqlite3_file_control(sqlite3 *db, const char *zDbName, int op, void *pArg){
3852   int rc = SQLITE_ERROR;
3853   Btree *pBtree;
3854 
3855 #ifdef SQLITE_ENABLE_API_ARMOR
3856   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3857 #endif
3858   sqlite3_mutex_enter(db->mutex);
3859   pBtree = sqlite3DbNameToBtree(db, zDbName);
3860   if( pBtree ){
3861     Pager *pPager;
3862     sqlite3_file *fd;
3863     sqlite3BtreeEnter(pBtree);
3864     pPager = sqlite3BtreePager(pBtree);
3865     assert( pPager!=0 );
3866     fd = sqlite3PagerFile(pPager);
3867     assert( fd!=0 );
3868     if( op==SQLITE_FCNTL_FILE_POINTER ){
3869       *(sqlite3_file**)pArg = fd;
3870       rc = SQLITE_OK;
3871     }else if( op==SQLITE_FCNTL_VFS_POINTER ){
3872       *(sqlite3_vfs**)pArg = sqlite3PagerVfs(pPager);
3873       rc = SQLITE_OK;
3874     }else if( op==SQLITE_FCNTL_JOURNAL_POINTER ){
3875       *(sqlite3_file**)pArg = sqlite3PagerJrnlFile(pPager);
3876       rc = SQLITE_OK;
3877     }else if( op==SQLITE_FCNTL_DATA_VERSION ){
3878       *(unsigned int*)pArg = sqlite3PagerDataVersion(pPager);
3879       rc = SQLITE_OK;
3880     }else if( op==SQLITE_FCNTL_RESERVE_BYTES ){
3881       int iNew = *(int*)pArg;
3882       *(int*)pArg = sqlite3BtreeGetRequestedReserve(pBtree);
3883       if( iNew>=0 && iNew<=255 ){
3884         sqlite3BtreeSetPageSize(pBtree, 0, iNew, 0);
3885       }
3886       rc = SQLITE_OK;
3887     }else{
3888       int nSave = db->busyHandler.nBusy;
3889       rc = sqlite3OsFileControl(fd, op, pArg);
3890       db->busyHandler.nBusy = nSave;
3891     }
3892     sqlite3BtreeLeave(pBtree);
3893   }
3894   sqlite3_mutex_leave(db->mutex);
3895   return rc;
3896 }
3897 
3898 /*
3899 ** Interface to the testing logic.
3900 */
3901 int sqlite3_test_control(int op, ...){
3902   int rc = 0;
3903 #ifdef SQLITE_UNTESTABLE
3904   UNUSED_PARAMETER(op);
3905 #else
3906   va_list ap;
3907   va_start(ap, op);
3908   switch( op ){
3909 
3910     /*
3911     ** Save the current state of the PRNG.
3912     */
3913     case SQLITE_TESTCTRL_PRNG_SAVE: {
3914       sqlite3PrngSaveState();
3915       break;
3916     }
3917 
3918     /*
3919     ** Restore the state of the PRNG to the last state saved using
3920     ** PRNG_SAVE.  If PRNG_SAVE has never before been called, then
3921     ** this verb acts like PRNG_RESET.
3922     */
3923     case SQLITE_TESTCTRL_PRNG_RESTORE: {
3924       sqlite3PrngRestoreState();
3925       break;
3926     }
3927 
3928     /*  sqlite3_test_control(SQLITE_TESTCTRL_PRNG_SEED, int x, sqlite3 *db);
3929     **
3930     ** Control the seed for the pseudo-random number generator (PRNG) that
3931     ** is built into SQLite.  Cases:
3932     **
3933     **    x!=0 && db!=0       Seed the PRNG to the current value of the
3934     **                        schema cookie in the main database for db, or
3935     **                        x if the schema cookie is zero.  This case
3936     **                        is convenient to use with database fuzzers
3937     **                        as it allows the fuzzer some control over the
3938     **                        the PRNG seed.
3939     **
3940     **    x!=0 && db==0       Seed the PRNG to the value of x.
3941     **
3942     **    x==0 && db==0       Revert to default behavior of using the
3943     **                        xRandomness method on the primary VFS.
3944     **
3945     ** This test-control also resets the PRNG so that the new seed will
3946     ** be used for the next call to sqlite3_randomness().
3947     */
3948 #ifndef SQLITE_OMIT_WSD
3949     case SQLITE_TESTCTRL_PRNG_SEED: {
3950       int x = va_arg(ap, int);
3951       int y;
3952       sqlite3 *db = va_arg(ap, sqlite3*);
3953       assert( db==0 || db->aDb[0].pSchema!=0 );
3954       if( db && (y = db->aDb[0].pSchema->schema_cookie)!=0 ){ x = y; }
3955       sqlite3Config.iPrngSeed = x;
3956       sqlite3_randomness(0,0);
3957       break;
3958     }
3959 #endif
3960 
3961     /*
3962     **  sqlite3_test_control(BITVEC_TEST, size, program)
3963     **
3964     ** Run a test against a Bitvec object of size.  The program argument
3965     ** is an array of integers that defines the test.  Return -1 on a
3966     ** memory allocation error, 0 on success, or non-zero for an error.
3967     ** See the sqlite3BitvecBuiltinTest() for additional information.
3968     */
3969     case SQLITE_TESTCTRL_BITVEC_TEST: {
3970       int sz = va_arg(ap, int);
3971       int *aProg = va_arg(ap, int*);
3972       rc = sqlite3BitvecBuiltinTest(sz, aProg);
3973       break;
3974     }
3975 
3976     /*
3977     **  sqlite3_test_control(FAULT_INSTALL, xCallback)
3978     **
3979     ** Arrange to invoke xCallback() whenever sqlite3FaultSim() is called,
3980     ** if xCallback is not NULL.
3981     **
3982     ** As a test of the fault simulator mechanism itself, sqlite3FaultSim(0)
3983     ** is called immediately after installing the new callback and the return
3984     ** value from sqlite3FaultSim(0) becomes the return from
3985     ** sqlite3_test_control().
3986     */
3987     case SQLITE_TESTCTRL_FAULT_INSTALL: {
3988       /* MSVC is picky about pulling func ptrs from va lists.
3989       ** http://support.microsoft.com/kb/47961
3990       ** sqlite3GlobalConfig.xTestCallback = va_arg(ap, int(*)(int));
3991       */
3992       typedef int(*TESTCALLBACKFUNC_t)(int);
3993       sqlite3GlobalConfig.xTestCallback = va_arg(ap, TESTCALLBACKFUNC_t);
3994       rc = sqlite3FaultSim(0);
3995       break;
3996     }
3997 
3998     /*
3999     **  sqlite3_test_control(BENIGN_MALLOC_HOOKS, xBegin, xEnd)
4000     **
4001     ** Register hooks to call to indicate which malloc() failures
4002     ** are benign.
4003     */
4004     case SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS: {
4005       typedef void (*void_function)(void);
4006       void_function xBenignBegin;
4007       void_function xBenignEnd;
4008       xBenignBegin = va_arg(ap, void_function);
4009       xBenignEnd = va_arg(ap, void_function);
4010       sqlite3BenignMallocHooks(xBenignBegin, xBenignEnd);
4011       break;
4012     }
4013 
4014     /*
4015     **  sqlite3_test_control(SQLITE_TESTCTRL_PENDING_BYTE, unsigned int X)
4016     **
4017     ** Set the PENDING byte to the value in the argument, if X>0.
4018     ** Make no changes if X==0.  Return the value of the pending byte
4019     ** as it existing before this routine was called.
4020     **
4021     ** IMPORTANT:  Changing the PENDING byte from 0x40000000 results in
4022     ** an incompatible database file format.  Changing the PENDING byte
4023     ** while any database connection is open results in undefined and
4024     ** deleterious behavior.
4025     */
4026     case SQLITE_TESTCTRL_PENDING_BYTE: {
4027       rc = PENDING_BYTE;
4028 #ifndef SQLITE_OMIT_WSD
4029       {
4030         unsigned int newVal = va_arg(ap, unsigned int);
4031         if( newVal ) sqlite3PendingByte = newVal;
4032       }
4033 #endif
4034       break;
4035     }
4036 
4037     /*
4038     **  sqlite3_test_control(SQLITE_TESTCTRL_ASSERT, int X)
4039     **
4040     ** This action provides a run-time test to see whether or not
4041     ** assert() was enabled at compile-time.  If X is true and assert()
4042     ** is enabled, then the return value is true.  If X is true and
4043     ** assert() is disabled, then the return value is zero.  If X is
4044     ** false and assert() is enabled, then the assertion fires and the
4045     ** process aborts.  If X is false and assert() is disabled, then the
4046     ** return value is zero.
4047     */
4048     case SQLITE_TESTCTRL_ASSERT: {
4049       volatile int x = 0;
4050       assert( /*side-effects-ok*/ (x = va_arg(ap,int))!=0 );
4051       rc = x;
4052       break;
4053     }
4054 
4055 
4056     /*
4057     **  sqlite3_test_control(SQLITE_TESTCTRL_ALWAYS, int X)
4058     **
4059     ** This action provides a run-time test to see how the ALWAYS and
4060     ** NEVER macros were defined at compile-time.
4061     **
4062     ** The return value is ALWAYS(X) if X is true, or 0 if X is false.
4063     **
4064     ** The recommended test is X==2.  If the return value is 2, that means
4065     ** ALWAYS() and NEVER() are both no-op pass-through macros, which is the
4066     ** default setting.  If the return value is 1, then ALWAYS() is either
4067     ** hard-coded to true or else it asserts if its argument is false.
4068     ** The first behavior (hard-coded to true) is the case if
4069     ** SQLITE_TESTCTRL_ASSERT shows that assert() is disabled and the second
4070     ** behavior (assert if the argument to ALWAYS() is false) is the case if
4071     ** SQLITE_TESTCTRL_ASSERT shows that assert() is enabled.
4072     **
4073     ** The run-time test procedure might look something like this:
4074     **
4075     **    if( sqlite3_test_control(SQLITE_TESTCTRL_ALWAYS, 2)==2 ){
4076     **      // ALWAYS() and NEVER() are no-op pass-through macros
4077     **    }else if( sqlite3_test_control(SQLITE_TESTCTRL_ASSERT, 1) ){
4078     **      // ALWAYS(x) asserts that x is true. NEVER(x) asserts x is false.
4079     **    }else{
4080     **      // ALWAYS(x) is a constant 1.  NEVER(x) is a constant 0.
4081     **    }
4082     */
4083     case SQLITE_TESTCTRL_ALWAYS: {
4084       int x = va_arg(ap,int);
4085       rc = x ? ALWAYS(x) : 0;
4086       break;
4087     }
4088 
4089     /*
4090     **   sqlite3_test_control(SQLITE_TESTCTRL_BYTEORDER);
4091     **
4092     ** The integer returned reveals the byte-order of the computer on which
4093     ** SQLite is running:
4094     **
4095     **       1     big-endian,    determined at run-time
4096     **      10     little-endian, determined at run-time
4097     **  432101     big-endian,    determined at compile-time
4098     **  123410     little-endian, determined at compile-time
4099     */
4100     case SQLITE_TESTCTRL_BYTEORDER: {
4101       rc = SQLITE_BYTEORDER*100 + SQLITE_LITTLEENDIAN*10 + SQLITE_BIGENDIAN;
4102       break;
4103     }
4104 
4105     /*  sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS, sqlite3 *db, int N)
4106     **
4107     ** Enable or disable various optimizations for testing purposes.  The
4108     ** argument N is a bitmask of optimizations to be disabled.  For normal
4109     ** operation N should be 0.  The idea is that a test program (like the
4110     ** SQL Logic Test or SLT test module) can run the same SQL multiple times
4111     ** with various optimizations disabled to verify that the same answer
4112     ** is obtained in every case.
4113     */
4114     case SQLITE_TESTCTRL_OPTIMIZATIONS: {
4115       sqlite3 *db = va_arg(ap, sqlite3*);
4116       db->dbOptFlags = va_arg(ap, u32);
4117       break;
4118     }
4119 
4120     /*   sqlite3_test_control(SQLITE_TESTCTRL_LOCALTIME_FAULT, int onoff);
4121     **
4122     ** If parameter onoff is non-zero, subsequent calls to localtime()
4123     ** and its variants fail. If onoff is zero, undo this setting.
4124     */
4125     case SQLITE_TESTCTRL_LOCALTIME_FAULT: {
4126       sqlite3GlobalConfig.bLocaltimeFault = va_arg(ap, int);
4127       break;
4128     }
4129 
4130     /*   sqlite3_test_control(SQLITE_TESTCTRL_INTERNAL_FUNCTIONS, sqlite3*);
4131     **
4132     ** Toggle the ability to use internal functions on or off for
4133     ** the database connection given in the argument.
4134     */
4135     case SQLITE_TESTCTRL_INTERNAL_FUNCTIONS: {
4136       sqlite3 *db = va_arg(ap, sqlite3*);
4137       db->mDbFlags ^= DBFLAG_InternalFunc;
4138       break;
4139     }
4140 
4141     /*   sqlite3_test_control(SQLITE_TESTCTRL_NEVER_CORRUPT, int);
4142     **
4143     ** Set or clear a flag that indicates that the database file is always well-
4144     ** formed and never corrupt.  This flag is clear by default, indicating that
4145     ** database files might have arbitrary corruption.  Setting the flag during
4146     ** testing causes certain assert() statements in the code to be activated
4147     ** that demonstrat invariants on well-formed database files.
4148     */
4149     case SQLITE_TESTCTRL_NEVER_CORRUPT: {
4150       sqlite3GlobalConfig.neverCorrupt = va_arg(ap, int);
4151       break;
4152     }
4153 
4154     /*   sqlite3_test_control(SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS, int);
4155     **
4156     ** Set or clear a flag that causes SQLite to verify that type, name,
4157     ** and tbl_name fields of the sqlite_schema table.  This is normally
4158     ** on, but it is sometimes useful to turn it off for testing.
4159     **
4160     ** 2020-07-22:  Disabling EXTRA_SCHEMA_CHECKS also disables the
4161     ** verification of rootpage numbers when parsing the schema.  This
4162     ** is useful to make it easier to reach strange internal error states
4163     ** during testing.  The EXTRA_SCHEMA_CHECKS setting is always enabled
4164     ** in production.
4165     */
4166     case SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS: {
4167       sqlite3GlobalConfig.bExtraSchemaChecks = va_arg(ap, int);
4168       break;
4169     }
4170 
4171     /* Set the threshold at which OP_Once counters reset back to zero.
4172     ** By default this is 0x7ffffffe (over 2 billion), but that value is
4173     ** too big to test in a reasonable amount of time, so this control is
4174     ** provided to set a small and easily reachable reset value.
4175     */
4176     case SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD: {
4177       sqlite3GlobalConfig.iOnceResetThreshold = va_arg(ap, int);
4178       break;
4179     }
4180 
4181     /*   sqlite3_test_control(SQLITE_TESTCTRL_VDBE_COVERAGE, xCallback, ptr);
4182     **
4183     ** Set the VDBE coverage callback function to xCallback with context
4184     ** pointer ptr.
4185     */
4186     case SQLITE_TESTCTRL_VDBE_COVERAGE: {
4187 #ifdef SQLITE_VDBE_COVERAGE
4188       typedef void (*branch_callback)(void*,unsigned int,
4189                                       unsigned char,unsigned char);
4190       sqlite3GlobalConfig.xVdbeBranch = va_arg(ap,branch_callback);
4191       sqlite3GlobalConfig.pVdbeBranchArg = va_arg(ap,void*);
4192 #endif
4193       break;
4194     }
4195 
4196     /*   sqlite3_test_control(SQLITE_TESTCTRL_SORTER_MMAP, db, nMax); */
4197     case SQLITE_TESTCTRL_SORTER_MMAP: {
4198       sqlite3 *db = va_arg(ap, sqlite3*);
4199       db->nMaxSorterMmap = va_arg(ap, int);
4200       break;
4201     }
4202 
4203     /*   sqlite3_test_control(SQLITE_TESTCTRL_ISINIT);
4204     **
4205     ** Return SQLITE_OK if SQLite has been initialized and SQLITE_ERROR if
4206     ** not.
4207     */
4208     case SQLITE_TESTCTRL_ISINIT: {
4209       if( sqlite3GlobalConfig.isInit==0 ) rc = SQLITE_ERROR;
4210       break;
4211     }
4212 
4213     /*  sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, db, dbName, onOff, tnum);
4214     **
4215     ** This test control is used to create imposter tables.  "db" is a pointer
4216     ** to the database connection.  dbName is the database name (ex: "main" or
4217     ** "temp") which will receive the imposter.  "onOff" turns imposter mode on
4218     ** or off.  "tnum" is the root page of the b-tree to which the imposter
4219     ** table should connect.
4220     **
4221     ** Enable imposter mode only when the schema has already been parsed.  Then
4222     ** run a single CREATE TABLE statement to construct the imposter table in
4223     ** the parsed schema.  Then turn imposter mode back off again.
4224     **
4225     ** If onOff==0 and tnum>0 then reset the schema for all databases, causing
4226     ** the schema to be reparsed the next time it is needed.  This has the
4227     ** effect of erasing all imposter tables.
4228     */
4229     case SQLITE_TESTCTRL_IMPOSTER: {
4230       sqlite3 *db = va_arg(ap, sqlite3*);
4231       sqlite3_mutex_enter(db->mutex);
4232       db->init.iDb = sqlite3FindDbName(db, va_arg(ap,const char*));
4233       db->init.busy = db->init.imposterTable = va_arg(ap,int);
4234       db->init.newTnum = va_arg(ap,int);
4235       if( db->init.busy==0 && db->init.newTnum>0 ){
4236         sqlite3ResetAllSchemasOfConnection(db);
4237       }
4238       sqlite3_mutex_leave(db->mutex);
4239       break;
4240     }
4241 
4242 #if defined(YYCOVERAGE)
4243     /*  sqlite3_test_control(SQLITE_TESTCTRL_PARSER_COVERAGE, FILE *out)
4244     **
4245     ** This test control (only available when SQLite is compiled with
4246     ** -DYYCOVERAGE) writes a report onto "out" that shows all
4247     ** state/lookahead combinations in the parser state machine
4248     ** which are never exercised.  If any state is missed, make the
4249     ** return code SQLITE_ERROR.
4250     */
4251     case SQLITE_TESTCTRL_PARSER_COVERAGE: {
4252       FILE *out = va_arg(ap, FILE*);
4253       if( sqlite3ParserCoverage(out) ) rc = SQLITE_ERROR;
4254       break;
4255     }
4256 #endif /* defined(YYCOVERAGE) */
4257 
4258     /*  sqlite3_test_control(SQLITE_TESTCTRL_RESULT_INTREAL, sqlite3_context*);
4259     **
4260     ** This test-control causes the most recent sqlite3_result_int64() value
4261     ** to be interpreted as a MEM_IntReal instead of as an MEM_Int.  Normally,
4262     ** MEM_IntReal values only arise during an INSERT operation of integer
4263     ** values into a REAL column, so they can be challenging to test.  This
4264     ** test-control enables us to write an intreal() SQL function that can
4265     ** inject an intreal() value at arbitrary places in an SQL statement,
4266     ** for testing purposes.
4267     */
4268     case SQLITE_TESTCTRL_RESULT_INTREAL: {
4269       sqlite3_context *pCtx = va_arg(ap, sqlite3_context*);
4270       sqlite3ResultIntReal(pCtx);
4271       break;
4272     }
4273 
4274     /*  sqlite3_test_control(SQLITE_TESTCTRL_SEEK_COUNT,
4275     **    sqlite3 *db,    // Database connection
4276     **    u64 *pnSeek     // Write seek count here
4277     **  );
4278     **
4279     ** This test-control queries the seek-counter on the "main" database
4280     ** file.  The seek-counter is written into *pnSeek and is then reset.
4281     ** The seek-count is only available if compiled with SQLITE_DEBUG.
4282     */
4283     case SQLITE_TESTCTRL_SEEK_COUNT: {
4284       sqlite3 *db = va_arg(ap, sqlite3*);
4285       u64 *pn = va_arg(ap, sqlite3_uint64*);
4286       *pn = sqlite3BtreeSeekCount(db->aDb->pBt);
4287       (void)db;  /* Silence harmless unused variable warning */
4288       break;
4289     }
4290 
4291     /*  sqlite3_test_control(SQLITE_TESTCTRL_TRACEFLAGS, op, ptr)
4292     **
4293     **  "ptr" is a pointer to a u32.
4294     **
4295     **   op==0       Store the current sqlite3SelectTrace in *ptr
4296     **   op==1       Set sqlite3SelectTrace to the value *ptr
4297     **   op==3       Store the current sqlite3WhereTrace in *ptr
4298     **   op==3       Set sqlite3WhereTrace to the value *ptr
4299     */
4300     case SQLITE_TESTCTRL_TRACEFLAGS: {
4301        int opTrace = va_arg(ap, int);
4302        u32 *ptr = va_arg(ap, u32*);
4303        switch( opTrace ){
4304          case 0:   *ptr = sqlite3SelectTrace;      break;
4305          case 1:   sqlite3SelectTrace = *ptr;      break;
4306          case 2:   *ptr = sqlite3WhereTrace;       break;
4307          case 3:   sqlite3WhereTrace = *ptr;       break;
4308        }
4309        break;
4310     }
4311 
4312 #if defined(SQLITE_DEBUG) && !defined(SQLITE_OMIT_WSD)
4313     /* sqlite3_test_control(SQLITE_TESTCTRL_TUNE, id, *piValue)
4314     **
4315     ** If "id" is an integer between 1 and SQLITE_NTUNE then set the value
4316     ** of the id-th tuning parameter to *piValue.  If "id" is between -1
4317     ** and -SQLITE_NTUNE, then write the current value of the (-id)-th
4318     ** tuning parameter into *piValue.
4319     **
4320     ** Tuning parameters are for use during transient development builds,
4321     ** to help find the best values for constants in the query planner.
4322     ** Access tuning parameters using the Tuning(ID) macro.  Set the
4323     ** parameters in the CLI using ".testctrl tune ID VALUE".
4324     **
4325     ** Transient use only.  Tuning parameters should not be used in
4326     ** checked-in code.
4327     */
4328     case SQLITE_TESTCTRL_TUNE: {
4329       int id = va_arg(ap, int);
4330       int *piValue = va_arg(ap, int*);
4331       if( id>0 && id<=SQLITE_NTUNE ){
4332         Tuning(id) = *piValue;
4333       }else if( id<0 && id>=-SQLITE_NTUNE ){
4334         *piValue = Tuning(-id);
4335       }else{
4336         rc = SQLITE_NOTFOUND;
4337       }
4338       break;
4339     }
4340 #endif
4341   }
4342   va_end(ap);
4343 #endif /* SQLITE_UNTESTABLE */
4344   return rc;
4345 }
4346 
4347 /*
4348 ** The Pager stores the Database filename, Journal filename, and WAL filename
4349 ** consecutively in memory, in that order.  The database filename is prefixed
4350 ** by four zero bytes.  Locate the start of the database filename by searching
4351 ** backwards for the first byte following four consecutive zero bytes.
4352 **
4353 ** This only works if the filename passed in was obtained from the Pager.
4354 */
4355 static const char *databaseName(const char *zName){
4356   while( zName[-1]!=0 || zName[-2]!=0 || zName[-3]!=0 || zName[-4]!=0 ){
4357     zName--;
4358   }
4359   return zName;
4360 }
4361 
4362 /*
4363 ** Append text z[] to the end of p[].  Return a pointer to the first
4364 ** character after then zero terminator on the new text in p[].
4365 */
4366 static char *appendText(char *p, const char *z){
4367   size_t n = strlen(z);
4368   memcpy(p, z, n+1);
4369   return p+n+1;
4370 }
4371 
4372 /*
4373 ** Allocate memory to hold names for a database, journal file, WAL file,
4374 ** and query parameters.  The pointer returned is valid for use by
4375 ** sqlite3_filename_database() and sqlite3_uri_parameter() and related
4376 ** functions.
4377 **
4378 ** Memory layout must be compatible with that generated by the pager
4379 ** and expected by sqlite3_uri_parameter() and databaseName().
4380 */
4381 char *sqlite3_create_filename(
4382   const char *zDatabase,
4383   const char *zJournal,
4384   const char *zWal,
4385   int nParam,
4386   const char **azParam
4387 ){
4388   sqlite3_int64 nByte;
4389   int i;
4390   char *pResult, *p;
4391   nByte = strlen(zDatabase) + strlen(zJournal) + strlen(zWal) + 10;
4392   for(i=0; i<nParam*2; i++){
4393     nByte += strlen(azParam[i])+1;
4394   }
4395   pResult = p = sqlite3_malloc64( nByte );
4396   if( p==0 ) return 0;
4397   memset(p, 0, 4);
4398   p += 4;
4399   p = appendText(p, zDatabase);
4400   for(i=0; i<nParam*2; i++){
4401     p = appendText(p, azParam[i]);
4402   }
4403   *(p++) = 0;
4404   p = appendText(p, zJournal);
4405   p = appendText(p, zWal);
4406   *(p++) = 0;
4407   *(p++) = 0;
4408   assert( (sqlite3_int64)(p - pResult)==nByte );
4409   return pResult + 4;
4410 }
4411 
4412 /*
4413 ** Free memory obtained from sqlite3_create_filename().  It is a severe
4414 ** error to call this routine with any parameter other than a pointer
4415 ** previously obtained from sqlite3_create_filename() or a NULL pointer.
4416 */
4417 void sqlite3_free_filename(char *p){
4418   if( p==0 ) return;
4419   p = (char*)databaseName(p);
4420   sqlite3_free(p - 4);
4421 }
4422 
4423 
4424 /*
4425 ** This is a utility routine, useful to VFS implementations, that checks
4426 ** to see if a database file was a URI that contained a specific query
4427 ** parameter, and if so obtains the value of the query parameter.
4428 **
4429 ** The zFilename argument is the filename pointer passed into the xOpen()
4430 ** method of a VFS implementation.  The zParam argument is the name of the
4431 ** query parameter we seek.  This routine returns the value of the zParam
4432 ** parameter if it exists.  If the parameter does not exist, this routine
4433 ** returns a NULL pointer.
4434 */
4435 const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam){
4436   if( zFilename==0 || zParam==0 ) return 0;
4437   zFilename = databaseName(zFilename);
4438   return uriParameter(zFilename, zParam);
4439 }
4440 
4441 /*
4442 ** Return a pointer to the name of Nth query parameter of the filename.
4443 */
4444 const char *sqlite3_uri_key(const char *zFilename, int N){
4445   if( zFilename==0 || N<0 ) return 0;
4446   zFilename = databaseName(zFilename);
4447   zFilename += sqlite3Strlen30(zFilename) + 1;
4448   while( ALWAYS(zFilename) && zFilename[0] && (N--)>0 ){
4449     zFilename += sqlite3Strlen30(zFilename) + 1;
4450     zFilename += sqlite3Strlen30(zFilename) + 1;
4451   }
4452   return zFilename[0] ? zFilename : 0;
4453 }
4454 
4455 /*
4456 ** Return a boolean value for a query parameter.
4457 */
4458 int sqlite3_uri_boolean(const char *zFilename, const char *zParam, int bDflt){
4459   const char *z = sqlite3_uri_parameter(zFilename, zParam);
4460   bDflt = bDflt!=0;
4461   return z ? sqlite3GetBoolean(z, bDflt) : bDflt;
4462 }
4463 
4464 /*
4465 ** Return a 64-bit integer value for a query parameter.
4466 */
4467 sqlite3_int64 sqlite3_uri_int64(
4468   const char *zFilename,    /* Filename as passed to xOpen */
4469   const char *zParam,       /* URI parameter sought */
4470   sqlite3_int64 bDflt       /* return if parameter is missing */
4471 ){
4472   const char *z = sqlite3_uri_parameter(zFilename, zParam);
4473   sqlite3_int64 v;
4474   if( z && sqlite3DecOrHexToI64(z, &v)==0 ){
4475     bDflt = v;
4476   }
4477   return bDflt;
4478 }
4479 
4480 /*
4481 ** Translate a filename that was handed to a VFS routine into the corresponding
4482 ** database, journal, or WAL file.
4483 **
4484 ** It is an error to pass this routine a filename string that was not
4485 ** passed into the VFS from the SQLite core.  Doing so is similar to
4486 ** passing free() a pointer that was not obtained from malloc() - it is
4487 ** an error that we cannot easily detect but that will likely cause memory
4488 ** corruption.
4489 */
4490 const char *sqlite3_filename_database(const char *zFilename){
4491   if( zFilename==0 ) return 0;
4492   return databaseName(zFilename);
4493 }
4494 const char *sqlite3_filename_journal(const char *zFilename){
4495   if( zFilename==0 ) return 0;
4496   zFilename = databaseName(zFilename);
4497   zFilename += sqlite3Strlen30(zFilename) + 1;
4498   while( ALWAYS(zFilename) && zFilename[0] ){
4499     zFilename += sqlite3Strlen30(zFilename) + 1;
4500     zFilename += sqlite3Strlen30(zFilename) + 1;
4501   }
4502   return zFilename + 1;
4503 }
4504 const char *sqlite3_filename_wal(const char *zFilename){
4505 #ifdef SQLITE_OMIT_WAL
4506   return 0;
4507 #else
4508   zFilename = sqlite3_filename_journal(zFilename);
4509   if( zFilename ) zFilename += sqlite3Strlen30(zFilename) + 1;
4510   return zFilename;
4511 #endif
4512 }
4513 
4514 /*
4515 ** Return the Btree pointer identified by zDbName.  Return NULL if not found.
4516 */
4517 Btree *sqlite3DbNameToBtree(sqlite3 *db, const char *zDbName){
4518   int iDb = zDbName ? sqlite3FindDbName(db, zDbName) : 0;
4519   return iDb<0 ? 0 : db->aDb[iDb].pBt;
4520 }
4521 
4522 /*
4523 ** Return the filename of the database associated with a database
4524 ** connection.
4525 */
4526 const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName){
4527   Btree *pBt;
4528 #ifdef SQLITE_ENABLE_API_ARMOR
4529   if( !sqlite3SafetyCheckOk(db) ){
4530     (void)SQLITE_MISUSE_BKPT;
4531     return 0;
4532   }
4533 #endif
4534   pBt = sqlite3DbNameToBtree(db, zDbName);
4535   return pBt ? sqlite3BtreeGetFilename(pBt) : 0;
4536 }
4537 
4538 /*
4539 ** Return 1 if database is read-only or 0 if read/write.  Return -1 if
4540 ** no such database exists.
4541 */
4542 int sqlite3_db_readonly(sqlite3 *db, const char *zDbName){
4543   Btree *pBt;
4544 #ifdef SQLITE_ENABLE_API_ARMOR
4545   if( !sqlite3SafetyCheckOk(db) ){
4546     (void)SQLITE_MISUSE_BKPT;
4547     return -1;
4548   }
4549 #endif
4550   pBt = sqlite3DbNameToBtree(db, zDbName);
4551   return pBt ? sqlite3BtreeIsReadonly(pBt) : -1;
4552 }
4553 
4554 #ifdef SQLITE_ENABLE_SNAPSHOT
4555 /*
4556 ** Obtain a snapshot handle for the snapshot of database zDb currently
4557 ** being read by handle db.
4558 */
4559 int sqlite3_snapshot_get(
4560   sqlite3 *db,
4561   const char *zDb,
4562   sqlite3_snapshot **ppSnapshot
4563 ){
4564   int rc = SQLITE_ERROR;
4565 #ifndef SQLITE_OMIT_WAL
4566 
4567 #ifdef SQLITE_ENABLE_API_ARMOR
4568   if( !sqlite3SafetyCheckOk(db) ){
4569     return SQLITE_MISUSE_BKPT;
4570   }
4571 #endif
4572   sqlite3_mutex_enter(db->mutex);
4573 
4574   if( db->autoCommit==0 ){
4575     int iDb = sqlite3FindDbName(db, zDb);
4576     if( iDb==0 || iDb>1 ){
4577       Btree *pBt = db->aDb[iDb].pBt;
4578       if( SQLITE_TXN_WRITE!=sqlite3BtreeTxnState(pBt) ){
4579         rc = sqlite3BtreeBeginTrans(pBt, 0, 0);
4580         if( rc==SQLITE_OK ){
4581           rc = sqlite3PagerSnapshotGet(sqlite3BtreePager(pBt), ppSnapshot);
4582         }
4583       }
4584     }
4585   }
4586 
4587   sqlite3_mutex_leave(db->mutex);
4588 #endif   /* SQLITE_OMIT_WAL */
4589   return rc;
4590 }
4591 
4592 /*
4593 ** Open a read-transaction on the snapshot idendified by pSnapshot.
4594 */
4595 int sqlite3_snapshot_open(
4596   sqlite3 *db,
4597   const char *zDb,
4598   sqlite3_snapshot *pSnapshot
4599 ){
4600   int rc = SQLITE_ERROR;
4601 #ifndef SQLITE_OMIT_WAL
4602 
4603 #ifdef SQLITE_ENABLE_API_ARMOR
4604   if( !sqlite3SafetyCheckOk(db) ){
4605     return SQLITE_MISUSE_BKPT;
4606   }
4607 #endif
4608   sqlite3_mutex_enter(db->mutex);
4609   if( db->autoCommit==0 ){
4610     int iDb;
4611     iDb = sqlite3FindDbName(db, zDb);
4612     if( iDb==0 || iDb>1 ){
4613       Btree *pBt = db->aDb[iDb].pBt;
4614       if( sqlite3BtreeTxnState(pBt)!=SQLITE_TXN_WRITE ){
4615         Pager *pPager = sqlite3BtreePager(pBt);
4616         int bUnlock = 0;
4617         if( sqlite3BtreeTxnState(pBt)!=SQLITE_TXN_NONE ){
4618           if( db->nVdbeActive==0 ){
4619             rc = sqlite3PagerSnapshotCheck(pPager, pSnapshot);
4620             if( rc==SQLITE_OK ){
4621               bUnlock = 1;
4622               rc = sqlite3BtreeCommit(pBt);
4623             }
4624           }
4625         }else{
4626           rc = SQLITE_OK;
4627         }
4628         if( rc==SQLITE_OK ){
4629           rc = sqlite3PagerSnapshotOpen(pPager, pSnapshot);
4630         }
4631         if( rc==SQLITE_OK ){
4632           rc = sqlite3BtreeBeginTrans(pBt, 0, 0);
4633           sqlite3PagerSnapshotOpen(pPager, 0);
4634         }
4635         if( bUnlock ){
4636           sqlite3PagerSnapshotUnlock(pPager);
4637         }
4638       }
4639     }
4640   }
4641 
4642   sqlite3_mutex_leave(db->mutex);
4643 #endif   /* SQLITE_OMIT_WAL */
4644   return rc;
4645 }
4646 
4647 /*
4648 ** Recover as many snapshots as possible from the wal file associated with
4649 ** schema zDb of database db.
4650 */
4651 int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb){
4652   int rc = SQLITE_ERROR;
4653   int iDb;
4654 #ifndef SQLITE_OMIT_WAL
4655 
4656 #ifdef SQLITE_ENABLE_API_ARMOR
4657   if( !sqlite3SafetyCheckOk(db) ){
4658     return SQLITE_MISUSE_BKPT;
4659   }
4660 #endif
4661 
4662   sqlite3_mutex_enter(db->mutex);
4663   iDb = sqlite3FindDbName(db, zDb);
4664   if( iDb==0 || iDb>1 ){
4665     Btree *pBt = db->aDb[iDb].pBt;
4666     if( SQLITE_TXN_NONE==sqlite3BtreeTxnState(pBt) ){
4667       rc = sqlite3BtreeBeginTrans(pBt, 0, 0);
4668       if( rc==SQLITE_OK ){
4669         rc = sqlite3PagerSnapshotRecover(sqlite3BtreePager(pBt));
4670         sqlite3BtreeCommit(pBt);
4671       }
4672     }
4673   }
4674   sqlite3_mutex_leave(db->mutex);
4675 #endif   /* SQLITE_OMIT_WAL */
4676   return rc;
4677 }
4678 
4679 /*
4680 ** Free a snapshot handle obtained from sqlite3_snapshot_get().
4681 */
4682 void sqlite3_snapshot_free(sqlite3_snapshot *pSnapshot){
4683   sqlite3_free(pSnapshot);
4684 }
4685 #endif /* SQLITE_ENABLE_SNAPSHOT */
4686 
4687 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
4688 /*
4689 ** Given the name of a compile-time option, return true if that option
4690 ** was used and false if not.
4691 **
4692 ** The name can optionally begin with "SQLITE_" but the "SQLITE_" prefix
4693 ** is not required for a match.
4694 */
4695 int sqlite3_compileoption_used(const char *zOptName){
4696   int i, n;
4697   int nOpt;
4698   const char **azCompileOpt;
4699 
4700 #if SQLITE_ENABLE_API_ARMOR
4701   if( zOptName==0 ){
4702     (void)SQLITE_MISUSE_BKPT;
4703     return 0;
4704   }
4705 #endif
4706 
4707   azCompileOpt = sqlite3CompileOptions(&nOpt);
4708 
4709   if( sqlite3StrNICmp(zOptName, "SQLITE_", 7)==0 ) zOptName += 7;
4710   n = sqlite3Strlen30(zOptName);
4711 
4712   /* Since nOpt is normally in single digits, a linear search is
4713   ** adequate. No need for a binary search. */
4714   for(i=0; i<nOpt; i++){
4715     if( sqlite3StrNICmp(zOptName, azCompileOpt[i], n)==0
4716      && sqlite3IsIdChar((unsigned char)azCompileOpt[i][n])==0
4717     ){
4718       return 1;
4719     }
4720   }
4721   return 0;
4722 }
4723 
4724 /*
4725 ** Return the N-th compile-time option string.  If N is out of range,
4726 ** return a NULL pointer.
4727 */
4728 const char *sqlite3_compileoption_get(int N){
4729   int nOpt;
4730   const char **azCompileOpt;
4731   azCompileOpt = sqlite3CompileOptions(&nOpt);
4732   if( N>=0 && N<nOpt ){
4733     return azCompileOpt[N];
4734   }
4735   return 0;
4736 }
4737 #endif /* SQLITE_OMIT_COMPILEOPTION_DIAGS */
4738