xref: /sqlite-3.40.0/src/main.c (revision aeb4e6ee)
1 /*
2 ** 2001 September 15
3 **
4 ** The author disclaims copyright to this source code.  In place of
5 ** a legal notice, here is a blessing:
6 **
7 **    May you do good and not evil.
8 **    May you find forgiveness for yourself and forgive others.
9 **    May you share freely, never taking more than you give.
10 **
11 *************************************************************************
12 ** Main file for the SQLite library.  The routines in this file
13 ** implement the programmer interface to the library.  Routines in
14 ** other files are for internal use by SQLite and should not be
15 ** accessed by users of the library.
16 */
17 #include "sqliteInt.h"
18 
19 #ifdef SQLITE_ENABLE_FTS3
20 # include "fts3.h"
21 #endif
22 #ifdef SQLITE_ENABLE_RTREE
23 # include "rtree.h"
24 #endif
25 #if defined(SQLITE_ENABLE_ICU) || defined(SQLITE_ENABLE_ICU_COLLATIONS)
26 # include "sqliteicu.h"
27 #endif
28 
29 /*
30 ** This is an extension initializer that is a no-op and always
31 ** succeeds, except that it fails if the fault-simulation is set
32 ** to 500.
33 */
34 static int sqlite3TestExtInit(sqlite3 *db){
35   (void)db;
36   return sqlite3FaultSim(500);
37 }
38 
39 
40 /*
41 ** Forward declarations of external module initializer functions
42 ** for modules that need them.
43 */
44 #ifdef SQLITE_ENABLE_FTS1
45 int sqlite3Fts1Init(sqlite3*);
46 #endif
47 #ifdef SQLITE_ENABLE_FTS2
48 int sqlite3Fts2Init(sqlite3*);
49 #endif
50 #ifdef SQLITE_ENABLE_FTS5
51 int sqlite3Fts5Init(sqlite3*);
52 #endif
53 #ifdef SQLITE_ENABLE_JSON1
54 int sqlite3Json1Init(sqlite3*);
55 #endif
56 #ifdef SQLITE_ENABLE_STMTVTAB
57 int sqlite3StmtVtabInit(sqlite3*);
58 #endif
59 
60 /*
61 ** An array of pointers to extension initializer functions for
62 ** built-in extensions.
63 */
64 static int (*const sqlite3BuiltinExtensions[])(sqlite3*) = {
65 #ifdef SQLITE_ENABLE_FTS1
66   sqlite3Fts1Init,
67 #endif
68 #ifdef SQLITE_ENABLE_FTS2
69   sqlite3Fts2Init,
70 #endif
71 #ifdef SQLITE_ENABLE_FTS3
72   sqlite3Fts3Init,
73 #endif
74 #ifdef SQLITE_ENABLE_FTS5
75   sqlite3Fts5Init,
76 #endif
77 #if defined(SQLITE_ENABLE_ICU) || defined(SQLITE_ENABLE_ICU_COLLATIONS)
78   sqlite3IcuInit,
79 #endif
80 #ifdef SQLITE_ENABLE_RTREE
81   sqlite3RtreeInit,
82 #endif
83 #ifdef SQLITE_ENABLE_DBPAGE_VTAB
84   sqlite3DbpageRegister,
85 #endif
86 #ifdef SQLITE_ENABLE_DBSTAT_VTAB
87   sqlite3DbstatRegister,
88 #endif
89   sqlite3TestExtInit,
90 #ifdef SQLITE_ENABLE_JSON1
91   sqlite3Json1Init,
92 #endif
93 #ifdef SQLITE_ENABLE_STMTVTAB
94   sqlite3StmtVtabInit,
95 #endif
96 #ifdef SQLITE_ENABLE_BYTECODE_VTAB
97   sqlite3VdbeBytecodeVtabInit,
98 #endif
99 };
100 
101 #ifndef SQLITE_AMALGAMATION
102 /* IMPLEMENTATION-OF: R-46656-45156 The sqlite3_version[] string constant
103 ** contains the text of SQLITE_VERSION macro.
104 */
105 const char sqlite3_version[] = SQLITE_VERSION;
106 #endif
107 
108 /* IMPLEMENTATION-OF: R-53536-42575 The sqlite3_libversion() function returns
109 ** a pointer to the to the sqlite3_version[] string constant.
110 */
111 const char *sqlite3_libversion(void){ return sqlite3_version; }
112 
113 /* IMPLEMENTATION-OF: R-25063-23286 The sqlite3_sourceid() function returns a
114 ** pointer to a string constant whose value is the same as the
115 ** SQLITE_SOURCE_ID C preprocessor macro. Except if SQLite is built using
116 ** an edited copy of the amalgamation, then the last four characters of
117 ** the hash might be different from SQLITE_SOURCE_ID.
118 */
119 const char *sqlite3_sourceid(void){ return SQLITE_SOURCE_ID; }
120 
121 /* IMPLEMENTATION-OF: R-35210-63508 The sqlite3_libversion_number() function
122 ** returns an integer equal to SQLITE_VERSION_NUMBER.
123 */
124 int sqlite3_libversion_number(void){ return SQLITE_VERSION_NUMBER; }
125 
126 /* IMPLEMENTATION-OF: R-20790-14025 The sqlite3_threadsafe() function returns
127 ** zero if and only if SQLite was compiled with mutexing code omitted due to
128 ** the SQLITE_THREADSAFE compile-time option being set to 0.
129 */
130 int sqlite3_threadsafe(void){ return SQLITE_THREADSAFE; }
131 
132 /*
133 ** When compiling the test fixture or with debugging enabled (on Win32),
134 ** this variable being set to non-zero will cause OSTRACE macros to emit
135 ** extra diagnostic information.
136 */
137 #ifdef SQLITE_HAVE_OS_TRACE
138 # ifndef SQLITE_DEBUG_OS_TRACE
139 #   define SQLITE_DEBUG_OS_TRACE 0
140 # endif
141   int sqlite3OSTrace = SQLITE_DEBUG_OS_TRACE;
142 #endif
143 
144 #if !defined(SQLITE_OMIT_TRACE) && defined(SQLITE_ENABLE_IOTRACE)
145 /*
146 ** If the following function pointer is not NULL and if
147 ** SQLITE_ENABLE_IOTRACE is enabled, then messages describing
148 ** I/O active are written using this function.  These messages
149 ** are intended for debugging activity only.
150 */
151 SQLITE_API void (SQLITE_CDECL *sqlite3IoTrace)(const char*, ...) = 0;
152 #endif
153 
154 /*
155 ** If the following global variable points to a string which is the
156 ** name of a directory, then that directory will be used to store
157 ** temporary files.
158 **
159 ** See also the "PRAGMA temp_store_directory" SQL command.
160 */
161 char *sqlite3_temp_directory = 0;
162 
163 /*
164 ** If the following global variable points to a string which is the
165 ** name of a directory, then that directory will be used to store
166 ** all database files specified with a relative pathname.
167 **
168 ** See also the "PRAGMA data_store_directory" SQL command.
169 */
170 char *sqlite3_data_directory = 0;
171 
172 /*
173 ** Initialize SQLite.
174 **
175 ** This routine must be called to initialize the memory allocation,
176 ** VFS, and mutex subsystems prior to doing any serious work with
177 ** SQLite.  But as long as you do not compile with SQLITE_OMIT_AUTOINIT
178 ** this routine will be called automatically by key routines such as
179 ** sqlite3_open().
180 **
181 ** This routine is a no-op except on its very first call for the process,
182 ** or for the first call after a call to sqlite3_shutdown.
183 **
184 ** The first thread to call this routine runs the initialization to
185 ** completion.  If subsequent threads call this routine before the first
186 ** thread has finished the initialization process, then the subsequent
187 ** threads must block until the first thread finishes with the initialization.
188 **
189 ** The first thread might call this routine recursively.  Recursive
190 ** calls to this routine should not block, of course.  Otherwise the
191 ** initialization process would never complete.
192 **
193 ** Let X be the first thread to enter this routine.  Let Y be some other
194 ** thread.  Then while the initial invocation of this routine by X is
195 ** incomplete, it is required that:
196 **
197 **    *  Calls to this routine from Y must block until the outer-most
198 **       call by X completes.
199 **
200 **    *  Recursive calls to this routine from thread X return immediately
201 **       without blocking.
202 */
203 int sqlite3_initialize(void){
204   MUTEX_LOGIC( sqlite3_mutex *pMainMtx; )      /* The main static mutex */
205   int rc;                                      /* Result code */
206 #ifdef SQLITE_EXTRA_INIT
207   int bRunExtraInit = 0;                       /* Extra initialization needed */
208 #endif
209 
210 #ifdef SQLITE_OMIT_WSD
211   rc = sqlite3_wsd_init(4096, 24);
212   if( rc!=SQLITE_OK ){
213     return rc;
214   }
215 #endif
216 
217   /* If the following assert() fails on some obscure processor/compiler
218   ** combination, the work-around is to set the correct pointer
219   ** size at compile-time using -DSQLITE_PTRSIZE=n compile-time option */
220   assert( SQLITE_PTRSIZE==sizeof(char*) );
221 
222   /* If SQLite is already completely initialized, then this call
223   ** to sqlite3_initialize() should be a no-op.  But the initialization
224   ** must be complete.  So isInit must not be set until the very end
225   ** of this routine.
226   */
227   if( sqlite3GlobalConfig.isInit ){
228     sqlite3MemoryBarrier();
229     return SQLITE_OK;
230   }
231 
232   /* Make sure the mutex subsystem is initialized.  If unable to
233   ** initialize the mutex subsystem, return early with the error.
234   ** If the system is so sick that we are unable to allocate a mutex,
235   ** there is not much SQLite is going to be able to do.
236   **
237   ** The mutex subsystem must take care of serializing its own
238   ** initialization.
239   */
240   rc = sqlite3MutexInit();
241   if( rc ) return rc;
242 
243   /* Initialize the malloc() system and the recursive pInitMutex mutex.
244   ** This operation is protected by the STATIC_MAIN mutex.  Note that
245   ** MutexAlloc() is called for a static mutex prior to initializing the
246   ** malloc subsystem - this implies that the allocation of a static
247   ** mutex must not require support from the malloc subsystem.
248   */
249   MUTEX_LOGIC( pMainMtx = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MAIN); )
250   sqlite3_mutex_enter(pMainMtx);
251   sqlite3GlobalConfig.isMutexInit = 1;
252   if( !sqlite3GlobalConfig.isMallocInit ){
253     rc = sqlite3MallocInit();
254   }
255   if( rc==SQLITE_OK ){
256     sqlite3GlobalConfig.isMallocInit = 1;
257     if( !sqlite3GlobalConfig.pInitMutex ){
258       sqlite3GlobalConfig.pInitMutex =
259            sqlite3MutexAlloc(SQLITE_MUTEX_RECURSIVE);
260       if( sqlite3GlobalConfig.bCoreMutex && !sqlite3GlobalConfig.pInitMutex ){
261         rc = SQLITE_NOMEM_BKPT;
262       }
263     }
264   }
265   if( rc==SQLITE_OK ){
266     sqlite3GlobalConfig.nRefInitMutex++;
267   }
268   sqlite3_mutex_leave(pMainMtx);
269 
270   /* If rc is not SQLITE_OK at this point, then either the malloc
271   ** subsystem could not be initialized or the system failed to allocate
272   ** the pInitMutex mutex. Return an error in either case.  */
273   if( rc!=SQLITE_OK ){
274     return rc;
275   }
276 
277   /* Do the rest of the initialization under the recursive mutex so
278   ** that we will be able to handle recursive calls into
279   ** sqlite3_initialize().  The recursive calls normally come through
280   ** sqlite3_os_init() when it invokes sqlite3_vfs_register(), but other
281   ** recursive calls might also be possible.
282   **
283   ** IMPLEMENTATION-OF: R-00140-37445 SQLite automatically serializes calls
284   ** to the xInit method, so the xInit method need not be threadsafe.
285   **
286   ** The following mutex is what serializes access to the appdef pcache xInit
287   ** methods.  The sqlite3_pcache_methods.xInit() all is embedded in the
288   ** call to sqlite3PcacheInitialize().
289   */
290   sqlite3_mutex_enter(sqlite3GlobalConfig.pInitMutex);
291   if( sqlite3GlobalConfig.isInit==0 && sqlite3GlobalConfig.inProgress==0 ){
292     sqlite3GlobalConfig.inProgress = 1;
293 #ifdef SQLITE_ENABLE_SQLLOG
294     {
295       extern void sqlite3_init_sqllog(void);
296       sqlite3_init_sqllog();
297     }
298 #endif
299     memset(&sqlite3BuiltinFunctions, 0, sizeof(sqlite3BuiltinFunctions));
300     sqlite3RegisterBuiltinFunctions();
301     if( sqlite3GlobalConfig.isPCacheInit==0 ){
302       rc = sqlite3PcacheInitialize();
303     }
304     if( rc==SQLITE_OK ){
305       sqlite3GlobalConfig.isPCacheInit = 1;
306       rc = sqlite3OsInit();
307     }
308 #ifdef SQLITE_ENABLE_DESERIALIZE
309     if( rc==SQLITE_OK ){
310       rc = sqlite3MemdbInit();
311     }
312 #endif
313     if( rc==SQLITE_OK ){
314       sqlite3PCacheBufferSetup( sqlite3GlobalConfig.pPage,
315           sqlite3GlobalConfig.szPage, sqlite3GlobalConfig.nPage);
316       sqlite3MemoryBarrier();
317       sqlite3GlobalConfig.isInit = 1;
318 #ifdef SQLITE_EXTRA_INIT
319       bRunExtraInit = 1;
320 #endif
321     }
322     sqlite3GlobalConfig.inProgress = 0;
323   }
324   sqlite3_mutex_leave(sqlite3GlobalConfig.pInitMutex);
325 
326   /* Go back under the static mutex and clean up the recursive
327   ** mutex to prevent a resource leak.
328   */
329   sqlite3_mutex_enter(pMainMtx);
330   sqlite3GlobalConfig.nRefInitMutex--;
331   if( sqlite3GlobalConfig.nRefInitMutex<=0 ){
332     assert( sqlite3GlobalConfig.nRefInitMutex==0 );
333     sqlite3_mutex_free(sqlite3GlobalConfig.pInitMutex);
334     sqlite3GlobalConfig.pInitMutex = 0;
335   }
336   sqlite3_mutex_leave(pMainMtx);
337 
338   /* The following is just a sanity check to make sure SQLite has
339   ** been compiled correctly.  It is important to run this code, but
340   ** we don't want to run it too often and soak up CPU cycles for no
341   ** reason.  So we run it once during initialization.
342   */
343 #ifndef NDEBUG
344 #ifndef SQLITE_OMIT_FLOATING_POINT
345   /* This section of code's only "output" is via assert() statements. */
346   if( rc==SQLITE_OK ){
347     u64 x = (((u64)1)<<63)-1;
348     double y;
349     assert(sizeof(x)==8);
350     assert(sizeof(x)==sizeof(y));
351     memcpy(&y, &x, 8);
352     assert( sqlite3IsNaN(y) );
353   }
354 #endif
355 #endif
356 
357   /* Do extra initialization steps requested by the SQLITE_EXTRA_INIT
358   ** compile-time option.
359   */
360 #ifdef SQLITE_EXTRA_INIT
361   if( bRunExtraInit ){
362     int SQLITE_EXTRA_INIT(const char*);
363     rc = SQLITE_EXTRA_INIT(0);
364   }
365 #endif
366 
367   return rc;
368 }
369 
370 /*
371 ** Undo the effects of sqlite3_initialize().  Must not be called while
372 ** there are outstanding database connections or memory allocations or
373 ** while any part of SQLite is otherwise in use in any thread.  This
374 ** routine is not threadsafe.  But it is safe to invoke this routine
375 ** on when SQLite is already shut down.  If SQLite is already shut down
376 ** when this routine is invoked, then this routine is a harmless no-op.
377 */
378 int sqlite3_shutdown(void){
379 #ifdef SQLITE_OMIT_WSD
380   int rc = sqlite3_wsd_init(4096, 24);
381   if( rc!=SQLITE_OK ){
382     return rc;
383   }
384 #endif
385 
386   if( sqlite3GlobalConfig.isInit ){
387 #ifdef SQLITE_EXTRA_SHUTDOWN
388     void SQLITE_EXTRA_SHUTDOWN(void);
389     SQLITE_EXTRA_SHUTDOWN();
390 #endif
391     sqlite3_os_end();
392     sqlite3_reset_auto_extension();
393     sqlite3GlobalConfig.isInit = 0;
394   }
395   if( sqlite3GlobalConfig.isPCacheInit ){
396     sqlite3PcacheShutdown();
397     sqlite3GlobalConfig.isPCacheInit = 0;
398   }
399   if( sqlite3GlobalConfig.isMallocInit ){
400     sqlite3MallocEnd();
401     sqlite3GlobalConfig.isMallocInit = 0;
402 
403 #ifndef SQLITE_OMIT_SHUTDOWN_DIRECTORIES
404     /* The heap subsystem has now been shutdown and these values are supposed
405     ** to be NULL or point to memory that was obtained from sqlite3_malloc(),
406     ** which would rely on that heap subsystem; therefore, make sure these
407     ** values cannot refer to heap memory that was just invalidated when the
408     ** heap subsystem was shutdown.  This is only done if the current call to
409     ** this function resulted in the heap subsystem actually being shutdown.
410     */
411     sqlite3_data_directory = 0;
412     sqlite3_temp_directory = 0;
413 #endif
414   }
415   if( sqlite3GlobalConfig.isMutexInit ){
416     sqlite3MutexEnd();
417     sqlite3GlobalConfig.isMutexInit = 0;
418   }
419 
420   return SQLITE_OK;
421 }
422 
423 /*
424 ** This API allows applications to modify the global configuration of
425 ** the SQLite library at run-time.
426 **
427 ** This routine should only be called when there are no outstanding
428 ** database connections or memory allocations.  This routine is not
429 ** threadsafe.  Failure to heed these warnings can lead to unpredictable
430 ** behavior.
431 */
432 int sqlite3_config(int op, ...){
433   va_list ap;
434   int rc = SQLITE_OK;
435 
436   /* sqlite3_config() shall return SQLITE_MISUSE if it is invoked while
437   ** the SQLite library is in use. */
438   if( sqlite3GlobalConfig.isInit ) return SQLITE_MISUSE_BKPT;
439 
440   va_start(ap, op);
441   switch( op ){
442 
443     /* Mutex configuration options are only available in a threadsafe
444     ** compile.
445     */
446 #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0  /* IMP: R-54466-46756 */
447     case SQLITE_CONFIG_SINGLETHREAD: {
448       /* EVIDENCE-OF: R-02748-19096 This option sets the threading mode to
449       ** Single-thread. */
450       sqlite3GlobalConfig.bCoreMutex = 0;  /* Disable mutex on core */
451       sqlite3GlobalConfig.bFullMutex = 0;  /* Disable mutex on connections */
452       break;
453     }
454 #endif
455 #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-20520-54086 */
456     case SQLITE_CONFIG_MULTITHREAD: {
457       /* EVIDENCE-OF: R-14374-42468 This option sets the threading mode to
458       ** Multi-thread. */
459       sqlite3GlobalConfig.bCoreMutex = 1;  /* Enable mutex on core */
460       sqlite3GlobalConfig.bFullMutex = 0;  /* Disable mutex on connections */
461       break;
462     }
463 #endif
464 #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-59593-21810 */
465     case SQLITE_CONFIG_SERIALIZED: {
466       /* EVIDENCE-OF: R-41220-51800 This option sets the threading mode to
467       ** Serialized. */
468       sqlite3GlobalConfig.bCoreMutex = 1;  /* Enable mutex on core */
469       sqlite3GlobalConfig.bFullMutex = 1;  /* Enable mutex on connections */
470       break;
471     }
472 #endif
473 #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-63666-48755 */
474     case SQLITE_CONFIG_MUTEX: {
475       /* Specify an alternative mutex implementation */
476       sqlite3GlobalConfig.mutex = *va_arg(ap, sqlite3_mutex_methods*);
477       break;
478     }
479 #endif
480 #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-14450-37597 */
481     case SQLITE_CONFIG_GETMUTEX: {
482       /* Retrieve the current mutex implementation */
483       *va_arg(ap, sqlite3_mutex_methods*) = sqlite3GlobalConfig.mutex;
484       break;
485     }
486 #endif
487 
488     case SQLITE_CONFIG_MALLOC: {
489       /* EVIDENCE-OF: R-55594-21030 The SQLITE_CONFIG_MALLOC option takes a
490       ** single argument which is a pointer to an instance of the
491       ** sqlite3_mem_methods structure. The argument specifies alternative
492       ** low-level memory allocation routines to be used in place of the memory
493       ** allocation routines built into SQLite. */
494       sqlite3GlobalConfig.m = *va_arg(ap, sqlite3_mem_methods*);
495       break;
496     }
497     case SQLITE_CONFIG_GETMALLOC: {
498       /* EVIDENCE-OF: R-51213-46414 The SQLITE_CONFIG_GETMALLOC option takes a
499       ** single argument which is a pointer to an instance of the
500       ** sqlite3_mem_methods structure. The sqlite3_mem_methods structure is
501       ** filled with the currently defined memory allocation routines. */
502       if( sqlite3GlobalConfig.m.xMalloc==0 ) sqlite3MemSetDefault();
503       *va_arg(ap, sqlite3_mem_methods*) = sqlite3GlobalConfig.m;
504       break;
505     }
506     case SQLITE_CONFIG_MEMSTATUS: {
507       /* EVIDENCE-OF: R-61275-35157 The SQLITE_CONFIG_MEMSTATUS option takes
508       ** single argument of type int, interpreted as a boolean, which enables
509       ** or disables the collection of memory allocation statistics. */
510       sqlite3GlobalConfig.bMemstat = va_arg(ap, int);
511       break;
512     }
513     case SQLITE_CONFIG_SMALL_MALLOC: {
514       sqlite3GlobalConfig.bSmallMalloc = va_arg(ap, int);
515       break;
516     }
517     case SQLITE_CONFIG_PAGECACHE: {
518       /* EVIDENCE-OF: R-18761-36601 There are three arguments to
519       ** SQLITE_CONFIG_PAGECACHE: A pointer to 8-byte aligned memory (pMem),
520       ** the size of each page cache line (sz), and the number of cache lines
521       ** (N). */
522       sqlite3GlobalConfig.pPage = va_arg(ap, void*);
523       sqlite3GlobalConfig.szPage = va_arg(ap, int);
524       sqlite3GlobalConfig.nPage = va_arg(ap, int);
525       break;
526     }
527     case SQLITE_CONFIG_PCACHE_HDRSZ: {
528       /* EVIDENCE-OF: R-39100-27317 The SQLITE_CONFIG_PCACHE_HDRSZ option takes
529       ** a single parameter which is a pointer to an integer and writes into
530       ** that integer the number of extra bytes per page required for each page
531       ** in SQLITE_CONFIG_PAGECACHE. */
532       *va_arg(ap, int*) =
533           sqlite3HeaderSizeBtree() +
534           sqlite3HeaderSizePcache() +
535           sqlite3HeaderSizePcache1();
536       break;
537     }
538 
539     case SQLITE_CONFIG_PCACHE: {
540       /* no-op */
541       break;
542     }
543     case SQLITE_CONFIG_GETPCACHE: {
544       /* now an error */
545       rc = SQLITE_ERROR;
546       break;
547     }
548 
549     case SQLITE_CONFIG_PCACHE2: {
550       /* EVIDENCE-OF: R-63325-48378 The SQLITE_CONFIG_PCACHE2 option takes a
551       ** single argument which is a pointer to an sqlite3_pcache_methods2
552       ** object. This object specifies the interface to a custom page cache
553       ** implementation. */
554       sqlite3GlobalConfig.pcache2 = *va_arg(ap, sqlite3_pcache_methods2*);
555       break;
556     }
557     case SQLITE_CONFIG_GETPCACHE2: {
558       /* EVIDENCE-OF: R-22035-46182 The SQLITE_CONFIG_GETPCACHE2 option takes a
559       ** single argument which is a pointer to an sqlite3_pcache_methods2
560       ** object. SQLite copies of the current page cache implementation into
561       ** that object. */
562       if( sqlite3GlobalConfig.pcache2.xInit==0 ){
563         sqlite3PCacheSetDefault();
564       }
565       *va_arg(ap, sqlite3_pcache_methods2*) = sqlite3GlobalConfig.pcache2;
566       break;
567     }
568 
569 /* EVIDENCE-OF: R-06626-12911 The SQLITE_CONFIG_HEAP option is only
570 ** available if SQLite is compiled with either SQLITE_ENABLE_MEMSYS3 or
571 ** SQLITE_ENABLE_MEMSYS5 and returns SQLITE_ERROR if invoked otherwise. */
572 #if defined(SQLITE_ENABLE_MEMSYS3) || defined(SQLITE_ENABLE_MEMSYS5)
573     case SQLITE_CONFIG_HEAP: {
574       /* EVIDENCE-OF: R-19854-42126 There are three arguments to
575       ** SQLITE_CONFIG_HEAP: An 8-byte aligned pointer to the memory, the
576       ** number of bytes in the memory buffer, and the minimum allocation size.
577       */
578       sqlite3GlobalConfig.pHeap = va_arg(ap, void*);
579       sqlite3GlobalConfig.nHeap = va_arg(ap, int);
580       sqlite3GlobalConfig.mnReq = va_arg(ap, int);
581 
582       if( sqlite3GlobalConfig.mnReq<1 ){
583         sqlite3GlobalConfig.mnReq = 1;
584       }else if( sqlite3GlobalConfig.mnReq>(1<<12) ){
585         /* cap min request size at 2^12 */
586         sqlite3GlobalConfig.mnReq = (1<<12);
587       }
588 
589       if( sqlite3GlobalConfig.pHeap==0 ){
590         /* EVIDENCE-OF: R-49920-60189 If the first pointer (the memory pointer)
591         ** is NULL, then SQLite reverts to using its default memory allocator
592         ** (the system malloc() implementation), undoing any prior invocation of
593         ** SQLITE_CONFIG_MALLOC.
594         **
595         ** Setting sqlite3GlobalConfig.m to all zeros will cause malloc to
596         ** revert to its default implementation when sqlite3_initialize() is run
597         */
598         memset(&sqlite3GlobalConfig.m, 0, sizeof(sqlite3GlobalConfig.m));
599       }else{
600         /* EVIDENCE-OF: R-61006-08918 If the memory pointer is not NULL then the
601         ** alternative memory allocator is engaged to handle all of SQLites
602         ** memory allocation needs. */
603 #ifdef SQLITE_ENABLE_MEMSYS3
604         sqlite3GlobalConfig.m = *sqlite3MemGetMemsys3();
605 #endif
606 #ifdef SQLITE_ENABLE_MEMSYS5
607         sqlite3GlobalConfig.m = *sqlite3MemGetMemsys5();
608 #endif
609       }
610       break;
611     }
612 #endif
613 
614     case SQLITE_CONFIG_LOOKASIDE: {
615       sqlite3GlobalConfig.szLookaside = va_arg(ap, int);
616       sqlite3GlobalConfig.nLookaside = va_arg(ap, int);
617       break;
618     }
619 
620     /* Record a pointer to the logger function and its first argument.
621     ** The default is NULL.  Logging is disabled if the function pointer is
622     ** NULL.
623     */
624     case SQLITE_CONFIG_LOG: {
625       /* MSVC is picky about pulling func ptrs from va lists.
626       ** http://support.microsoft.com/kb/47961
627       ** sqlite3GlobalConfig.xLog = va_arg(ap, void(*)(void*,int,const char*));
628       */
629       typedef void(*LOGFUNC_t)(void*,int,const char*);
630       sqlite3GlobalConfig.xLog = va_arg(ap, LOGFUNC_t);
631       sqlite3GlobalConfig.pLogArg = va_arg(ap, void*);
632       break;
633     }
634 
635     /* EVIDENCE-OF: R-55548-33817 The compile-time setting for URI filenames
636     ** can be changed at start-time using the
637     ** sqlite3_config(SQLITE_CONFIG_URI,1) or
638     ** sqlite3_config(SQLITE_CONFIG_URI,0) configuration calls.
639     */
640     case SQLITE_CONFIG_URI: {
641       /* EVIDENCE-OF: R-25451-61125 The SQLITE_CONFIG_URI option takes a single
642       ** argument of type int. If non-zero, then URI handling is globally
643       ** enabled. If the parameter is zero, then URI handling is globally
644       ** disabled. */
645       sqlite3GlobalConfig.bOpenUri = va_arg(ap, int);
646       break;
647     }
648 
649     case SQLITE_CONFIG_COVERING_INDEX_SCAN: {
650       /* EVIDENCE-OF: R-36592-02772 The SQLITE_CONFIG_COVERING_INDEX_SCAN
651       ** option takes a single integer argument which is interpreted as a
652       ** boolean in order to enable or disable the use of covering indices for
653       ** full table scans in the query optimizer. */
654       sqlite3GlobalConfig.bUseCis = va_arg(ap, int);
655       break;
656     }
657 
658 #ifdef SQLITE_ENABLE_SQLLOG
659     case SQLITE_CONFIG_SQLLOG: {
660       typedef void(*SQLLOGFUNC_t)(void*, sqlite3*, const char*, int);
661       sqlite3GlobalConfig.xSqllog = va_arg(ap, SQLLOGFUNC_t);
662       sqlite3GlobalConfig.pSqllogArg = va_arg(ap, void *);
663       break;
664     }
665 #endif
666 
667     case SQLITE_CONFIG_MMAP_SIZE: {
668       /* EVIDENCE-OF: R-58063-38258 SQLITE_CONFIG_MMAP_SIZE takes two 64-bit
669       ** integer (sqlite3_int64) values that are the default mmap size limit
670       ** (the default setting for PRAGMA mmap_size) and the maximum allowed
671       ** mmap size limit. */
672       sqlite3_int64 szMmap = va_arg(ap, sqlite3_int64);
673       sqlite3_int64 mxMmap = va_arg(ap, sqlite3_int64);
674       /* EVIDENCE-OF: R-53367-43190 If either argument to this option is
675       ** negative, then that argument is changed to its compile-time default.
676       **
677       ** EVIDENCE-OF: R-34993-45031 The maximum allowed mmap size will be
678       ** silently truncated if necessary so that it does not exceed the
679       ** compile-time maximum mmap size set by the SQLITE_MAX_MMAP_SIZE
680       ** compile-time option.
681       */
682       if( mxMmap<0 || mxMmap>SQLITE_MAX_MMAP_SIZE ){
683         mxMmap = SQLITE_MAX_MMAP_SIZE;
684       }
685       if( szMmap<0 ) szMmap = SQLITE_DEFAULT_MMAP_SIZE;
686       if( szMmap>mxMmap) szMmap = mxMmap;
687       sqlite3GlobalConfig.mxMmap = mxMmap;
688       sqlite3GlobalConfig.szMmap = szMmap;
689       break;
690     }
691 
692 #if SQLITE_OS_WIN && defined(SQLITE_WIN32_MALLOC) /* IMP: R-04780-55815 */
693     case SQLITE_CONFIG_WIN32_HEAPSIZE: {
694       /* EVIDENCE-OF: R-34926-03360 SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit
695       ** unsigned integer value that specifies the maximum size of the created
696       ** heap. */
697       sqlite3GlobalConfig.nHeap = va_arg(ap, int);
698       break;
699     }
700 #endif
701 
702     case SQLITE_CONFIG_PMASZ: {
703       sqlite3GlobalConfig.szPma = va_arg(ap, unsigned int);
704       break;
705     }
706 
707     case SQLITE_CONFIG_STMTJRNL_SPILL: {
708       sqlite3GlobalConfig.nStmtSpill = va_arg(ap, int);
709       break;
710     }
711 
712 #ifdef SQLITE_ENABLE_SORTER_REFERENCES
713     case SQLITE_CONFIG_SORTERREF_SIZE: {
714       int iVal = va_arg(ap, int);
715       if( iVal<0 ){
716         iVal = SQLITE_DEFAULT_SORTERREF_SIZE;
717       }
718       sqlite3GlobalConfig.szSorterRef = (u32)iVal;
719       break;
720     }
721 #endif /* SQLITE_ENABLE_SORTER_REFERENCES */
722 
723 #ifdef SQLITE_ENABLE_DESERIALIZE
724     case SQLITE_CONFIG_MEMDB_MAXSIZE: {
725       sqlite3GlobalConfig.mxMemdbSize = va_arg(ap, sqlite3_int64);
726       break;
727     }
728 #endif /* SQLITE_ENABLE_DESERIALIZE */
729 
730     default: {
731       rc = SQLITE_ERROR;
732       break;
733     }
734   }
735   va_end(ap);
736   return rc;
737 }
738 
739 /*
740 ** Set up the lookaside buffers for a database connection.
741 ** Return SQLITE_OK on success.
742 ** If lookaside is already active, return SQLITE_BUSY.
743 **
744 ** The sz parameter is the number of bytes in each lookaside slot.
745 ** The cnt parameter is the number of slots.  If pStart is NULL the
746 ** space for the lookaside memory is obtained from sqlite3_malloc().
747 ** If pStart is not NULL then it is sz*cnt bytes of memory to use for
748 ** the lookaside memory.
749 */
750 static int setupLookaside(sqlite3 *db, void *pBuf, int sz, int cnt){
751 #ifndef SQLITE_OMIT_LOOKASIDE
752   void *pStart;
753   sqlite3_int64 szAlloc = sz*(sqlite3_int64)cnt;
754   int nBig;   /* Number of full-size slots */
755   int nSm;    /* Number smaller LOOKASIDE_SMALL-byte slots */
756 
757   if( sqlite3LookasideUsed(db,0)>0 ){
758     return SQLITE_BUSY;
759   }
760   /* Free any existing lookaside buffer for this handle before
761   ** allocating a new one so we don't have to have space for
762   ** both at the same time.
763   */
764   if( db->lookaside.bMalloced ){
765     sqlite3_free(db->lookaside.pStart);
766   }
767   /* The size of a lookaside slot after ROUNDDOWN8 needs to be larger
768   ** than a pointer to be useful.
769   */
770   sz = ROUNDDOWN8(sz);  /* IMP: R-33038-09382 */
771   if( sz<=(int)sizeof(LookasideSlot*) ) sz = 0;
772   if( cnt<0 ) cnt = 0;
773   if( sz==0 || cnt==0 ){
774     sz = 0;
775     pStart = 0;
776   }else if( pBuf==0 ){
777     sqlite3BeginBenignMalloc();
778     pStart = sqlite3Malloc( szAlloc );  /* IMP: R-61949-35727 */
779     sqlite3EndBenignMalloc();
780     if( pStart ) szAlloc = sqlite3MallocSize(pStart);
781   }else{
782     pStart = pBuf;
783   }
784 #ifndef SQLITE_OMIT_TWOSIZE_LOOKASIDE
785   if( sz>=LOOKASIDE_SMALL*3 ){
786     nBig = szAlloc/(3*LOOKASIDE_SMALL+sz);
787     nSm = (szAlloc - sz*nBig)/LOOKASIDE_SMALL;
788   }else if( sz>=LOOKASIDE_SMALL*2 ){
789     nBig = szAlloc/(LOOKASIDE_SMALL+sz);
790     nSm = (szAlloc - sz*nBig)/LOOKASIDE_SMALL;
791   }else
792 #endif /* SQLITE_OMIT_TWOSIZE_LOOKASIDE */
793   if( sz>0 ){
794     nBig = szAlloc/sz;
795     nSm = 0;
796   }else{
797     nBig = nSm = 0;
798   }
799   db->lookaside.pStart = pStart;
800   db->lookaside.pInit = 0;
801   db->lookaside.pFree = 0;
802   db->lookaside.sz = (u16)sz;
803   db->lookaside.szTrue = (u16)sz;
804   if( pStart ){
805     int i;
806     LookasideSlot *p;
807     assert( sz > (int)sizeof(LookasideSlot*) );
808     p = (LookasideSlot*)pStart;
809     for(i=0; i<nBig; i++){
810       p->pNext = db->lookaside.pInit;
811       db->lookaside.pInit = p;
812       p = (LookasideSlot*)&((u8*)p)[sz];
813     }
814 #ifndef SQLITE_OMIT_TWOSIZE_LOOKASIDE
815     db->lookaside.pSmallInit = 0;
816     db->lookaside.pSmallFree = 0;
817     db->lookaside.pMiddle = p;
818     for(i=0; i<nSm; i++){
819       p->pNext = db->lookaside.pSmallInit;
820       db->lookaside.pSmallInit = p;
821       p = (LookasideSlot*)&((u8*)p)[LOOKASIDE_SMALL];
822     }
823 #endif /* SQLITE_OMIT_TWOSIZE_LOOKASIDE */
824     assert( ((uptr)p)<=szAlloc + (uptr)pStart );
825     db->lookaside.pEnd = p;
826     db->lookaside.bDisable = 0;
827     db->lookaside.bMalloced = pBuf==0 ?1:0;
828     db->lookaside.nSlot = nBig+nSm;
829   }else{
830     db->lookaside.pStart = db;
831 #ifndef SQLITE_OMIT_TWOSIZE_LOOKASIDE
832     db->lookaside.pSmallInit = 0;
833     db->lookaside.pSmallFree = 0;
834     db->lookaside.pMiddle = db;
835 #endif /* SQLITE_OMIT_TWOSIZE_LOOKASIDE */
836     db->lookaside.pEnd = db;
837     db->lookaside.bDisable = 1;
838     db->lookaside.sz = 0;
839     db->lookaside.bMalloced = 0;
840     db->lookaside.nSlot = 0;
841   }
842   assert( sqlite3LookasideUsed(db,0)==0 );
843 #endif /* SQLITE_OMIT_LOOKASIDE */
844   return SQLITE_OK;
845 }
846 
847 /*
848 ** Return the mutex associated with a database connection.
849 */
850 sqlite3_mutex *sqlite3_db_mutex(sqlite3 *db){
851 #ifdef SQLITE_ENABLE_API_ARMOR
852   if( !sqlite3SafetyCheckOk(db) ){
853     (void)SQLITE_MISUSE_BKPT;
854     return 0;
855   }
856 #endif
857   return db->mutex;
858 }
859 
860 /*
861 ** Free up as much memory as we can from the given database
862 ** connection.
863 */
864 int sqlite3_db_release_memory(sqlite3 *db){
865   int i;
866 
867 #ifdef SQLITE_ENABLE_API_ARMOR
868   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
869 #endif
870   sqlite3_mutex_enter(db->mutex);
871   sqlite3BtreeEnterAll(db);
872   for(i=0; i<db->nDb; i++){
873     Btree *pBt = db->aDb[i].pBt;
874     if( pBt ){
875       Pager *pPager = sqlite3BtreePager(pBt);
876       sqlite3PagerShrink(pPager);
877     }
878   }
879   sqlite3BtreeLeaveAll(db);
880   sqlite3_mutex_leave(db->mutex);
881   return SQLITE_OK;
882 }
883 
884 /*
885 ** Flush any dirty pages in the pager-cache for any attached database
886 ** to disk.
887 */
888 int sqlite3_db_cacheflush(sqlite3 *db){
889   int i;
890   int rc = SQLITE_OK;
891   int bSeenBusy = 0;
892 
893 #ifdef SQLITE_ENABLE_API_ARMOR
894   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
895 #endif
896   sqlite3_mutex_enter(db->mutex);
897   sqlite3BtreeEnterAll(db);
898   for(i=0; rc==SQLITE_OK && i<db->nDb; i++){
899     Btree *pBt = db->aDb[i].pBt;
900     if( pBt && 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 int sqlite3_changes(sqlite3 *db){
1090 #ifdef SQLITE_ENABLE_API_ARMOR
1091   if( !sqlite3SafetyCheckOk(db) ){
1092     (void)SQLITE_MISUSE_BKPT;
1093     return 0;
1094   }
1095 #endif
1096   return db->nChange;
1097 }
1098 
1099 /*
1100 ** Return the number of changes since the database handle was opened.
1101 */
1102 int sqlite3_total_changes(sqlite3 *db){
1103 #ifdef SQLITE_ENABLE_API_ARMOR
1104   if( !sqlite3SafetyCheckOk(db) ){
1105     (void)SQLITE_MISUSE_BKPT;
1106     return 0;
1107   }
1108 #endif
1109   return db->nTotalChange;
1110 }
1111 
1112 /*
1113 ** Close all open savepoints. This function only manipulates fields of the
1114 ** database handle object, it does not close any savepoints that may be open
1115 ** at the b-tree/pager level.
1116 */
1117 void sqlite3CloseSavepoints(sqlite3 *db){
1118   while( db->pSavepoint ){
1119     Savepoint *pTmp = db->pSavepoint;
1120     db->pSavepoint = pTmp->pNext;
1121     sqlite3DbFree(db, pTmp);
1122   }
1123   db->nSavepoint = 0;
1124   db->nStatement = 0;
1125   db->isTransactionSavepoint = 0;
1126 }
1127 
1128 /*
1129 ** Invoke the destructor function associated with FuncDef p, if any. Except,
1130 ** if this is not the last copy of the function, do not invoke it. Multiple
1131 ** copies of a single function are created when create_function() is called
1132 ** with SQLITE_ANY as the encoding.
1133 */
1134 static void functionDestroy(sqlite3 *db, FuncDef *p){
1135   FuncDestructor *pDestructor = p->u.pDestructor;
1136   if( pDestructor ){
1137     pDestructor->nRef--;
1138     if( pDestructor->nRef==0 ){
1139       pDestructor->xDestroy(pDestructor->pUserData);
1140       sqlite3DbFree(db, pDestructor);
1141     }
1142   }
1143 }
1144 
1145 /*
1146 ** Disconnect all sqlite3_vtab objects that belong to database connection
1147 ** db. This is called when db is being closed.
1148 */
1149 static void disconnectAllVtab(sqlite3 *db){
1150 #ifndef SQLITE_OMIT_VIRTUALTABLE
1151   int i;
1152   HashElem *p;
1153   sqlite3BtreeEnterAll(db);
1154   for(i=0; i<db->nDb; i++){
1155     Schema *pSchema = db->aDb[i].pSchema;
1156     if( pSchema ){
1157       for(p=sqliteHashFirst(&pSchema->tblHash); p; p=sqliteHashNext(p)){
1158         Table *pTab = (Table *)sqliteHashData(p);
1159         if( IsVirtual(pTab) ) sqlite3VtabDisconnect(db, pTab);
1160       }
1161     }
1162   }
1163   for(p=sqliteHashFirst(&db->aModule); p; p=sqliteHashNext(p)){
1164     Module *pMod = (Module *)sqliteHashData(p);
1165     if( pMod->pEpoTab ){
1166       sqlite3VtabDisconnect(db, pMod->pEpoTab);
1167     }
1168   }
1169   sqlite3VtabUnlockList(db);
1170   sqlite3BtreeLeaveAll(db);
1171 #else
1172   UNUSED_PARAMETER(db);
1173 #endif
1174 }
1175 
1176 /*
1177 ** Return TRUE if database connection db has unfinalized prepared
1178 ** statements or unfinished sqlite3_backup objects.
1179 */
1180 static int connectionIsBusy(sqlite3 *db){
1181   int j;
1182   assert( sqlite3_mutex_held(db->mutex) );
1183   if( db->pVdbe ) return 1;
1184   for(j=0; j<db->nDb; j++){
1185     Btree *pBt = db->aDb[j].pBt;
1186     if( pBt && sqlite3BtreeIsInBackup(pBt) ) return 1;
1187   }
1188   return 0;
1189 }
1190 
1191 /*
1192 ** Close an existing SQLite database
1193 */
1194 static int sqlite3Close(sqlite3 *db, int forceZombie){
1195   if( !db ){
1196     /* EVIDENCE-OF: R-63257-11740 Calling sqlite3_close() or
1197     ** sqlite3_close_v2() with a NULL pointer argument is a harmless no-op. */
1198     return SQLITE_OK;
1199   }
1200   if( !sqlite3SafetyCheckSickOrOk(db) ){
1201     return SQLITE_MISUSE_BKPT;
1202   }
1203   sqlite3_mutex_enter(db->mutex);
1204   if( db->mTrace & SQLITE_TRACE_CLOSE ){
1205     db->trace.xV2(SQLITE_TRACE_CLOSE, db->pTraceArg, db, 0);
1206   }
1207 
1208   /* Force xDisconnect calls on all virtual tables */
1209   disconnectAllVtab(db);
1210 
1211   /* If a transaction is open, the disconnectAllVtab() call above
1212   ** will not have called the xDisconnect() method on any virtual
1213   ** tables in the db->aVTrans[] array. The following sqlite3VtabRollback()
1214   ** call will do so. We need to do this before the check for active
1215   ** SQL statements below, as the v-table implementation may be storing
1216   ** some prepared statements internally.
1217   */
1218   sqlite3VtabRollback(db);
1219 
1220   /* Legacy behavior (sqlite3_close() behavior) is to return
1221   ** SQLITE_BUSY if the connection can not be closed immediately.
1222   */
1223   if( !forceZombie && connectionIsBusy(db) ){
1224     sqlite3ErrorWithMsg(db, SQLITE_BUSY, "unable to close due to unfinalized "
1225        "statements or unfinished backups");
1226     sqlite3_mutex_leave(db->mutex);
1227     return SQLITE_BUSY;
1228   }
1229 
1230 #ifdef SQLITE_ENABLE_SQLLOG
1231   if( sqlite3GlobalConfig.xSqllog ){
1232     /* Closing the handle. Fourth parameter is passed the value 2. */
1233     sqlite3GlobalConfig.xSqllog(sqlite3GlobalConfig.pSqllogArg, db, 0, 2);
1234   }
1235 #endif
1236 
1237   /* Convert the connection into a zombie and then close it.
1238   */
1239   db->magic = SQLITE_MAGIC_ZOMBIE;
1240   sqlite3LeaveMutexAndCloseZombie(db);
1241   return SQLITE_OK;
1242 }
1243 
1244 /*
1245 ** Return the transaction state for a single databse, or the maximum
1246 ** transaction state over all attached databases if zSchema is null.
1247 */
1248 int sqlite3_txn_state(sqlite3 *db, const char *zSchema){
1249   int iDb, nDb;
1250   int iTxn = -1;
1251 #ifdef SQLITE_ENABLE_API_ARMOR
1252   if( !sqlite3SafetyCheckOk(db) ){
1253     (void)SQLITE_MISUSE_BKPT;
1254     return -1;
1255   }
1256 #endif
1257   sqlite3_mutex_enter(db->mutex);
1258   if( zSchema ){
1259     nDb = iDb = sqlite3FindDbName(db, zSchema);
1260     if( iDb<0 ) nDb--;
1261   }else{
1262     iDb = 0;
1263     nDb = db->nDb-1;
1264   }
1265   for(; iDb<=nDb; iDb++){
1266     Btree *pBt = db->aDb[iDb].pBt;
1267     int x = pBt!=0 ? sqlite3BtreeTxnState(pBt) : SQLITE_TXN_NONE;
1268     if( x>iTxn ) iTxn = x;
1269   }
1270   sqlite3_mutex_leave(db->mutex);
1271   return iTxn;
1272 }
1273 
1274 /*
1275 ** Two variations on the public interface for closing a database
1276 ** connection. The sqlite3_close() version returns SQLITE_BUSY and
1277 ** leaves the connection option if there are unfinalized prepared
1278 ** statements or unfinished sqlite3_backups.  The sqlite3_close_v2()
1279 ** version forces the connection to become a zombie if there are
1280 ** unclosed resources, and arranges for deallocation when the last
1281 ** prepare statement or sqlite3_backup closes.
1282 */
1283 int sqlite3_close(sqlite3 *db){ return sqlite3Close(db,0); }
1284 int sqlite3_close_v2(sqlite3 *db){ return sqlite3Close(db,1); }
1285 
1286 
1287 /*
1288 ** Close the mutex on database connection db.
1289 **
1290 ** Furthermore, if database connection db is a zombie (meaning that there
1291 ** has been a prior call to sqlite3_close(db) or sqlite3_close_v2(db)) and
1292 ** every sqlite3_stmt has now been finalized and every sqlite3_backup has
1293 ** finished, then free all resources.
1294 */
1295 void sqlite3LeaveMutexAndCloseZombie(sqlite3 *db){
1296   HashElem *i;                    /* Hash table iterator */
1297   int j;
1298 
1299   /* If there are outstanding sqlite3_stmt or sqlite3_backup objects
1300   ** or if the connection has not yet been closed by sqlite3_close_v2(),
1301   ** then just leave the mutex and return.
1302   */
1303   if( db->magic!=SQLITE_MAGIC_ZOMBIE || connectionIsBusy(db) ){
1304     sqlite3_mutex_leave(db->mutex);
1305     return;
1306   }
1307 
1308   /* If we reach this point, it means that the database connection has
1309   ** closed all sqlite3_stmt and sqlite3_backup objects and has been
1310   ** passed to sqlite3_close (meaning that it is a zombie).  Therefore,
1311   ** go ahead and free all resources.
1312   */
1313 
1314   /* If a transaction is open, roll it back. This also ensures that if
1315   ** any database schemas have been modified by an uncommitted transaction
1316   ** they are reset. And that the required b-tree mutex is held to make
1317   ** the pager rollback and schema reset an atomic operation. */
1318   sqlite3RollbackAll(db, SQLITE_OK);
1319 
1320   /* Free any outstanding Savepoint structures. */
1321   sqlite3CloseSavepoints(db);
1322 
1323   /* Close all database connections */
1324   for(j=0; j<db->nDb; j++){
1325     struct Db *pDb = &db->aDb[j];
1326     if( pDb->pBt ){
1327       sqlite3BtreeClose(pDb->pBt);
1328       pDb->pBt = 0;
1329       if( j!=1 ){
1330         pDb->pSchema = 0;
1331       }
1332     }
1333   }
1334   /* Clear the TEMP schema separately and last */
1335   if( db->aDb[1].pSchema ){
1336     sqlite3SchemaClear(db->aDb[1].pSchema);
1337   }
1338   sqlite3VtabUnlockList(db);
1339 
1340   /* Free up the array of auxiliary databases */
1341   sqlite3CollapseDatabaseArray(db);
1342   assert( db->nDb<=2 );
1343   assert( db->aDb==db->aDbStatic );
1344 
1345   /* Tell the code in notify.c that the connection no longer holds any
1346   ** locks and does not require any further unlock-notify callbacks.
1347   */
1348   sqlite3ConnectionClosed(db);
1349 
1350   for(i=sqliteHashFirst(&db->aFunc); i; i=sqliteHashNext(i)){
1351     FuncDef *pNext, *p;
1352     p = sqliteHashData(i);
1353     do{
1354       functionDestroy(db, p);
1355       pNext = p->pNext;
1356       sqlite3DbFree(db, p);
1357       p = pNext;
1358     }while( p );
1359   }
1360   sqlite3HashClear(&db->aFunc);
1361   for(i=sqliteHashFirst(&db->aCollSeq); i; i=sqliteHashNext(i)){
1362     CollSeq *pColl = (CollSeq *)sqliteHashData(i);
1363     /* Invoke any destructors registered for collation sequence user data. */
1364     for(j=0; j<3; j++){
1365       if( pColl[j].xDel ){
1366         pColl[j].xDel(pColl[j].pUser);
1367       }
1368     }
1369     sqlite3DbFree(db, pColl);
1370   }
1371   sqlite3HashClear(&db->aCollSeq);
1372 #ifndef SQLITE_OMIT_VIRTUALTABLE
1373   for(i=sqliteHashFirst(&db->aModule); i; i=sqliteHashNext(i)){
1374     Module *pMod = (Module *)sqliteHashData(i);
1375     sqlite3VtabEponymousTableClear(db, pMod);
1376     sqlite3VtabModuleUnref(db, pMod);
1377   }
1378   sqlite3HashClear(&db->aModule);
1379 #endif
1380 
1381   sqlite3Error(db, SQLITE_OK); /* Deallocates any cached error strings. */
1382   sqlite3ValueFree(db->pErr);
1383   sqlite3CloseExtensions(db);
1384 #if SQLITE_USER_AUTHENTICATION
1385   sqlite3_free(db->auth.zAuthUser);
1386   sqlite3_free(db->auth.zAuthPW);
1387 #endif
1388 
1389   db->magic = SQLITE_MAGIC_ERROR;
1390 
1391   /* The temp-database schema is allocated differently from the other schema
1392   ** objects (using sqliteMalloc() directly, instead of sqlite3BtreeSchema()).
1393   ** So it needs to be freed here. Todo: Why not roll the temp schema into
1394   ** the same sqliteMalloc() as the one that allocates the database
1395   ** structure?
1396   */
1397   sqlite3DbFree(db, db->aDb[1].pSchema);
1398   sqlite3_mutex_leave(db->mutex);
1399   db->magic = SQLITE_MAGIC_CLOSED;
1400   sqlite3_mutex_free(db->mutex);
1401   assert( sqlite3LookasideUsed(db,0)==0 );
1402   if( db->lookaside.bMalloced ){
1403     sqlite3_free(db->lookaside.pStart);
1404   }
1405   sqlite3_free(db);
1406 }
1407 
1408 /*
1409 ** Rollback all database files.  If tripCode is not SQLITE_OK, then
1410 ** any write cursors are invalidated ("tripped" - as in "tripping a circuit
1411 ** breaker") and made to return tripCode if there are any further
1412 ** attempts to use that cursor.  Read cursors remain open and valid
1413 ** but are "saved" in case the table pages are moved around.
1414 */
1415 void sqlite3RollbackAll(sqlite3 *db, int tripCode){
1416   int i;
1417   int inTrans = 0;
1418   int schemaChange;
1419   assert( sqlite3_mutex_held(db->mutex) );
1420   sqlite3BeginBenignMalloc();
1421 
1422   /* Obtain all b-tree mutexes before making any calls to BtreeRollback().
1423   ** This is important in case the transaction being rolled back has
1424   ** modified the database schema. If the b-tree mutexes are not taken
1425   ** here, then another shared-cache connection might sneak in between
1426   ** the database rollback and schema reset, which can cause false
1427   ** corruption reports in some cases.  */
1428   sqlite3BtreeEnterAll(db);
1429   schemaChange = (db->mDbFlags & DBFLAG_SchemaChange)!=0 && db->init.busy==0;
1430 
1431   for(i=0; i<db->nDb; i++){
1432     Btree *p = db->aDb[i].pBt;
1433     if( p ){
1434       if( sqlite3BtreeTxnState(p)==SQLITE_TXN_WRITE ){
1435         inTrans = 1;
1436       }
1437       sqlite3BtreeRollback(p, tripCode, !schemaChange);
1438     }
1439   }
1440   sqlite3VtabRollback(db);
1441   sqlite3EndBenignMalloc();
1442 
1443   if( schemaChange ){
1444     sqlite3ExpirePreparedStatements(db, 0);
1445     sqlite3ResetAllSchemasOfConnection(db);
1446   }
1447   sqlite3BtreeLeaveAll(db);
1448 
1449   /* Any deferred constraint violations have now been resolved. */
1450   db->nDeferredCons = 0;
1451   db->nDeferredImmCons = 0;
1452   db->flags &= ~(u64)SQLITE_DeferFKs;
1453 
1454   /* If one has been configured, invoke the rollback-hook callback */
1455   if( db->xRollbackCallback && (inTrans || !db->autoCommit) ){
1456     db->xRollbackCallback(db->pRollbackArg);
1457   }
1458 }
1459 
1460 /*
1461 ** Return a static string containing the name corresponding to the error code
1462 ** specified in the argument.
1463 */
1464 #if defined(SQLITE_NEED_ERR_NAME)
1465 const char *sqlite3ErrName(int rc){
1466   const char *zName = 0;
1467   int i, origRc = rc;
1468   for(i=0; i<2 && zName==0; i++, rc &= 0xff){
1469     switch( rc ){
1470       case SQLITE_OK:                 zName = "SQLITE_OK";                break;
1471       case SQLITE_ERROR:              zName = "SQLITE_ERROR";             break;
1472       case SQLITE_ERROR_SNAPSHOT:     zName = "SQLITE_ERROR_SNAPSHOT";    break;
1473       case SQLITE_INTERNAL:           zName = "SQLITE_INTERNAL";          break;
1474       case SQLITE_PERM:               zName = "SQLITE_PERM";              break;
1475       case SQLITE_ABORT:              zName = "SQLITE_ABORT";             break;
1476       case SQLITE_ABORT_ROLLBACK:     zName = "SQLITE_ABORT_ROLLBACK";    break;
1477       case SQLITE_BUSY:               zName = "SQLITE_BUSY";              break;
1478       case SQLITE_BUSY_RECOVERY:      zName = "SQLITE_BUSY_RECOVERY";     break;
1479       case SQLITE_BUSY_SNAPSHOT:      zName = "SQLITE_BUSY_SNAPSHOT";     break;
1480       case SQLITE_LOCKED:             zName = "SQLITE_LOCKED";            break;
1481       case SQLITE_LOCKED_SHAREDCACHE: zName = "SQLITE_LOCKED_SHAREDCACHE";break;
1482       case SQLITE_NOMEM:              zName = "SQLITE_NOMEM";             break;
1483       case SQLITE_READONLY:           zName = "SQLITE_READONLY";          break;
1484       case SQLITE_READONLY_RECOVERY:  zName = "SQLITE_READONLY_RECOVERY"; break;
1485       case SQLITE_READONLY_CANTINIT:  zName = "SQLITE_READONLY_CANTINIT"; break;
1486       case SQLITE_READONLY_ROLLBACK:  zName = "SQLITE_READONLY_ROLLBACK"; break;
1487       case SQLITE_READONLY_DBMOVED:   zName = "SQLITE_READONLY_DBMOVED";  break;
1488       case SQLITE_READONLY_DIRECTORY: zName = "SQLITE_READONLY_DIRECTORY";break;
1489       case SQLITE_INTERRUPT:          zName = "SQLITE_INTERRUPT";         break;
1490       case SQLITE_IOERR:              zName = "SQLITE_IOERR";             break;
1491       case SQLITE_IOERR_READ:         zName = "SQLITE_IOERR_READ";        break;
1492       case SQLITE_IOERR_SHORT_READ:   zName = "SQLITE_IOERR_SHORT_READ";  break;
1493       case SQLITE_IOERR_WRITE:        zName = "SQLITE_IOERR_WRITE";       break;
1494       case SQLITE_IOERR_FSYNC:        zName = "SQLITE_IOERR_FSYNC";       break;
1495       case SQLITE_IOERR_DIR_FSYNC:    zName = "SQLITE_IOERR_DIR_FSYNC";   break;
1496       case SQLITE_IOERR_TRUNCATE:     zName = "SQLITE_IOERR_TRUNCATE";    break;
1497       case SQLITE_IOERR_FSTAT:        zName = "SQLITE_IOERR_FSTAT";       break;
1498       case SQLITE_IOERR_UNLOCK:       zName = "SQLITE_IOERR_UNLOCK";      break;
1499       case SQLITE_IOERR_RDLOCK:       zName = "SQLITE_IOERR_RDLOCK";      break;
1500       case SQLITE_IOERR_DELETE:       zName = "SQLITE_IOERR_DELETE";      break;
1501       case SQLITE_IOERR_NOMEM:        zName = "SQLITE_IOERR_NOMEM";       break;
1502       case SQLITE_IOERR_ACCESS:       zName = "SQLITE_IOERR_ACCESS";      break;
1503       case SQLITE_IOERR_CHECKRESERVEDLOCK:
1504                                 zName = "SQLITE_IOERR_CHECKRESERVEDLOCK"; break;
1505       case SQLITE_IOERR_LOCK:         zName = "SQLITE_IOERR_LOCK";        break;
1506       case SQLITE_IOERR_CLOSE:        zName = "SQLITE_IOERR_CLOSE";       break;
1507       case SQLITE_IOERR_DIR_CLOSE:    zName = "SQLITE_IOERR_DIR_CLOSE";   break;
1508       case SQLITE_IOERR_SHMOPEN:      zName = "SQLITE_IOERR_SHMOPEN";     break;
1509       case SQLITE_IOERR_SHMSIZE:      zName = "SQLITE_IOERR_SHMSIZE";     break;
1510       case SQLITE_IOERR_SHMLOCK:      zName = "SQLITE_IOERR_SHMLOCK";     break;
1511       case SQLITE_IOERR_SHMMAP:       zName = "SQLITE_IOERR_SHMMAP";      break;
1512       case SQLITE_IOERR_SEEK:         zName = "SQLITE_IOERR_SEEK";        break;
1513       case SQLITE_IOERR_DELETE_NOENT: zName = "SQLITE_IOERR_DELETE_NOENT";break;
1514       case SQLITE_IOERR_MMAP:         zName = "SQLITE_IOERR_MMAP";        break;
1515       case SQLITE_IOERR_GETTEMPPATH:  zName = "SQLITE_IOERR_GETTEMPPATH"; break;
1516       case SQLITE_IOERR_CONVPATH:     zName = "SQLITE_IOERR_CONVPATH";    break;
1517       case SQLITE_CORRUPT:            zName = "SQLITE_CORRUPT";           break;
1518       case SQLITE_CORRUPT_VTAB:       zName = "SQLITE_CORRUPT_VTAB";      break;
1519       case SQLITE_NOTFOUND:           zName = "SQLITE_NOTFOUND";          break;
1520       case SQLITE_FULL:               zName = "SQLITE_FULL";              break;
1521       case SQLITE_CANTOPEN:           zName = "SQLITE_CANTOPEN";          break;
1522       case SQLITE_CANTOPEN_NOTEMPDIR: zName = "SQLITE_CANTOPEN_NOTEMPDIR";break;
1523       case SQLITE_CANTOPEN_ISDIR:     zName = "SQLITE_CANTOPEN_ISDIR";    break;
1524       case SQLITE_CANTOPEN_FULLPATH:  zName = "SQLITE_CANTOPEN_FULLPATH"; break;
1525       case SQLITE_CANTOPEN_CONVPATH:  zName = "SQLITE_CANTOPEN_CONVPATH"; break;
1526       case SQLITE_CANTOPEN_SYMLINK:   zName = "SQLITE_CANTOPEN_SYMLINK";  break;
1527       case SQLITE_PROTOCOL:           zName = "SQLITE_PROTOCOL";          break;
1528       case SQLITE_EMPTY:              zName = "SQLITE_EMPTY";             break;
1529       case SQLITE_SCHEMA:             zName = "SQLITE_SCHEMA";            break;
1530       case SQLITE_TOOBIG:             zName = "SQLITE_TOOBIG";            break;
1531       case SQLITE_CONSTRAINT:         zName = "SQLITE_CONSTRAINT";        break;
1532       case SQLITE_CONSTRAINT_UNIQUE:  zName = "SQLITE_CONSTRAINT_UNIQUE"; break;
1533       case SQLITE_CONSTRAINT_TRIGGER: zName = "SQLITE_CONSTRAINT_TRIGGER";break;
1534       case SQLITE_CONSTRAINT_FOREIGNKEY:
1535                                 zName = "SQLITE_CONSTRAINT_FOREIGNKEY";   break;
1536       case SQLITE_CONSTRAINT_CHECK:   zName = "SQLITE_CONSTRAINT_CHECK";  break;
1537       case SQLITE_CONSTRAINT_PRIMARYKEY:
1538                                 zName = "SQLITE_CONSTRAINT_PRIMARYKEY";   break;
1539       case SQLITE_CONSTRAINT_NOTNULL: zName = "SQLITE_CONSTRAINT_NOTNULL";break;
1540       case SQLITE_CONSTRAINT_COMMITHOOK:
1541                                 zName = "SQLITE_CONSTRAINT_COMMITHOOK";   break;
1542       case SQLITE_CONSTRAINT_VTAB:    zName = "SQLITE_CONSTRAINT_VTAB";   break;
1543       case SQLITE_CONSTRAINT_FUNCTION:
1544                                 zName = "SQLITE_CONSTRAINT_FUNCTION";     break;
1545       case SQLITE_CONSTRAINT_ROWID:   zName = "SQLITE_CONSTRAINT_ROWID";  break;
1546       case SQLITE_MISMATCH:           zName = "SQLITE_MISMATCH";          break;
1547       case SQLITE_MISUSE:             zName = "SQLITE_MISUSE";            break;
1548       case SQLITE_NOLFS:              zName = "SQLITE_NOLFS";             break;
1549       case SQLITE_AUTH:               zName = "SQLITE_AUTH";              break;
1550       case SQLITE_FORMAT:             zName = "SQLITE_FORMAT";            break;
1551       case SQLITE_RANGE:              zName = "SQLITE_RANGE";             break;
1552       case SQLITE_NOTADB:             zName = "SQLITE_NOTADB";            break;
1553       case SQLITE_ROW:                zName = "SQLITE_ROW";               break;
1554       case SQLITE_NOTICE:             zName = "SQLITE_NOTICE";            break;
1555       case SQLITE_NOTICE_RECOVER_WAL: zName = "SQLITE_NOTICE_RECOVER_WAL";break;
1556       case SQLITE_NOTICE_RECOVER_ROLLBACK:
1557                                 zName = "SQLITE_NOTICE_RECOVER_ROLLBACK"; break;
1558       case SQLITE_WARNING:            zName = "SQLITE_WARNING";           break;
1559       case SQLITE_WARNING_AUTOINDEX:  zName = "SQLITE_WARNING_AUTOINDEX"; break;
1560       case SQLITE_DONE:               zName = "SQLITE_DONE";              break;
1561     }
1562   }
1563   if( zName==0 ){
1564     static char zBuf[50];
1565     sqlite3_snprintf(sizeof(zBuf), zBuf, "SQLITE_UNKNOWN(%d)", origRc);
1566     zName = zBuf;
1567   }
1568   return zName;
1569 }
1570 #endif
1571 
1572 /*
1573 ** Return a static string that describes the kind of error specified in the
1574 ** argument.
1575 */
1576 const char *sqlite3ErrStr(int rc){
1577   static const char* const aMsg[] = {
1578     /* SQLITE_OK          */ "not an error",
1579     /* SQLITE_ERROR       */ "SQL logic error",
1580     /* SQLITE_INTERNAL    */ 0,
1581     /* SQLITE_PERM        */ "access permission denied",
1582     /* SQLITE_ABORT       */ "query aborted",
1583     /* SQLITE_BUSY        */ "database is locked",
1584     /* SQLITE_LOCKED      */ "database table is locked",
1585     /* SQLITE_NOMEM       */ "out of memory",
1586     /* SQLITE_READONLY    */ "attempt to write a readonly database",
1587     /* SQLITE_INTERRUPT   */ "interrupted",
1588     /* SQLITE_IOERR       */ "disk I/O error",
1589     /* SQLITE_CORRUPT     */ "database disk image is malformed",
1590     /* SQLITE_NOTFOUND    */ "unknown operation",
1591     /* SQLITE_FULL        */ "database or disk is full",
1592     /* SQLITE_CANTOPEN    */ "unable to open database file",
1593     /* SQLITE_PROTOCOL    */ "locking protocol",
1594     /* SQLITE_EMPTY       */ 0,
1595     /* SQLITE_SCHEMA      */ "database schema has changed",
1596     /* SQLITE_TOOBIG      */ "string or blob too big",
1597     /* SQLITE_CONSTRAINT  */ "constraint failed",
1598     /* SQLITE_MISMATCH    */ "datatype mismatch",
1599     /* SQLITE_MISUSE      */ "bad parameter or other API misuse",
1600 #ifdef SQLITE_DISABLE_LFS
1601     /* SQLITE_NOLFS       */ "large file support is disabled",
1602 #else
1603     /* SQLITE_NOLFS       */ 0,
1604 #endif
1605     /* SQLITE_AUTH        */ "authorization denied",
1606     /* SQLITE_FORMAT      */ 0,
1607     /* SQLITE_RANGE       */ "column index out of range",
1608     /* SQLITE_NOTADB      */ "file is not a database",
1609     /* SQLITE_NOTICE      */ "notification message",
1610     /* SQLITE_WARNING     */ "warning message",
1611   };
1612   const char *zErr = "unknown error";
1613   switch( rc ){
1614     case SQLITE_ABORT_ROLLBACK: {
1615       zErr = "abort due to ROLLBACK";
1616       break;
1617     }
1618     case SQLITE_ROW: {
1619       zErr = "another row available";
1620       break;
1621     }
1622     case SQLITE_DONE: {
1623       zErr = "no more rows available";
1624       break;
1625     }
1626     default: {
1627       rc &= 0xff;
1628       if( ALWAYS(rc>=0) && rc<ArraySize(aMsg) && aMsg[rc]!=0 ){
1629         zErr = aMsg[rc];
1630       }
1631       break;
1632     }
1633   }
1634   return zErr;
1635 }
1636 
1637 /*
1638 ** This routine implements a busy callback that sleeps and tries
1639 ** again until a timeout value is reached.  The timeout value is
1640 ** an integer number of milliseconds passed in as the first
1641 ** argument.
1642 **
1643 ** Return non-zero to retry the lock.  Return zero to stop trying
1644 ** and cause SQLite to return SQLITE_BUSY.
1645 */
1646 static int sqliteDefaultBusyCallback(
1647   void *ptr,               /* Database connection */
1648   int count                /* Number of times table has been busy */
1649 ){
1650 #if SQLITE_OS_WIN || HAVE_USLEEP
1651   /* This case is for systems that have support for sleeping for fractions of
1652   ** a second.  Examples:  All windows systems, unix systems with usleep() */
1653   static const u8 delays[] =
1654      { 1, 2, 5, 10, 15, 20, 25, 25,  25,  50,  50, 100 };
1655   static const u8 totals[] =
1656      { 0, 1, 3,  8, 18, 33, 53, 78, 103, 128, 178, 228 };
1657 # define NDELAY ArraySize(delays)
1658   sqlite3 *db = (sqlite3 *)ptr;
1659   int tmout = db->busyTimeout;
1660   int delay, prior;
1661 
1662   assert( count>=0 );
1663   if( count < NDELAY ){
1664     delay = delays[count];
1665     prior = totals[count];
1666   }else{
1667     delay = delays[NDELAY-1];
1668     prior = totals[NDELAY-1] + delay*(count-(NDELAY-1));
1669   }
1670   if( prior + delay > tmout ){
1671     delay = tmout - prior;
1672     if( delay<=0 ) return 0;
1673   }
1674   sqlite3OsSleep(db->pVfs, delay*1000);
1675   return 1;
1676 #else
1677   /* This case for unix systems that lack usleep() support.  Sleeping
1678   ** must be done in increments of whole seconds */
1679   sqlite3 *db = (sqlite3 *)ptr;
1680   int tmout = ((sqlite3 *)ptr)->busyTimeout;
1681   if( (count+1)*1000 > tmout ){
1682     return 0;
1683   }
1684   sqlite3OsSleep(db->pVfs, 1000000);
1685   return 1;
1686 #endif
1687 }
1688 
1689 /*
1690 ** Invoke the given busy handler.
1691 **
1692 ** This routine is called when an operation failed to acquire a
1693 ** lock on VFS file pFile.
1694 **
1695 ** If this routine returns non-zero, the lock is retried.  If it
1696 ** returns 0, the operation aborts with an SQLITE_BUSY error.
1697 */
1698 int sqlite3InvokeBusyHandler(BusyHandler *p){
1699   int rc;
1700   if( p->xBusyHandler==0 || p->nBusy<0 ) return 0;
1701   rc = p->xBusyHandler(p->pBusyArg, p->nBusy);
1702   if( rc==0 ){
1703     p->nBusy = -1;
1704   }else{
1705     p->nBusy++;
1706   }
1707   return rc;
1708 }
1709 
1710 /*
1711 ** This routine sets the busy callback for an Sqlite database to the
1712 ** given callback function with the given argument.
1713 */
1714 int sqlite3_busy_handler(
1715   sqlite3 *db,
1716   int (*xBusy)(void*,int),
1717   void *pArg
1718 ){
1719 #ifdef SQLITE_ENABLE_API_ARMOR
1720   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
1721 #endif
1722   sqlite3_mutex_enter(db->mutex);
1723   db->busyHandler.xBusyHandler = xBusy;
1724   db->busyHandler.pBusyArg = pArg;
1725   db->busyHandler.nBusy = 0;
1726   db->busyTimeout = 0;
1727   sqlite3_mutex_leave(db->mutex);
1728   return SQLITE_OK;
1729 }
1730 
1731 #ifndef SQLITE_OMIT_PROGRESS_CALLBACK
1732 /*
1733 ** This routine sets the progress callback for an Sqlite database to the
1734 ** given callback function with the given argument. The progress callback will
1735 ** be invoked every nOps opcodes.
1736 */
1737 void sqlite3_progress_handler(
1738   sqlite3 *db,
1739   int nOps,
1740   int (*xProgress)(void*),
1741   void *pArg
1742 ){
1743 #ifdef SQLITE_ENABLE_API_ARMOR
1744   if( !sqlite3SafetyCheckOk(db) ){
1745     (void)SQLITE_MISUSE_BKPT;
1746     return;
1747   }
1748 #endif
1749   sqlite3_mutex_enter(db->mutex);
1750   if( nOps>0 ){
1751     db->xProgress = xProgress;
1752     db->nProgressOps = (unsigned)nOps;
1753     db->pProgressArg = pArg;
1754   }else{
1755     db->xProgress = 0;
1756     db->nProgressOps = 0;
1757     db->pProgressArg = 0;
1758   }
1759   sqlite3_mutex_leave(db->mutex);
1760 }
1761 #endif
1762 
1763 
1764 /*
1765 ** This routine installs a default busy handler that waits for the
1766 ** specified number of milliseconds before returning 0.
1767 */
1768 int sqlite3_busy_timeout(sqlite3 *db, int ms){
1769 #ifdef SQLITE_ENABLE_API_ARMOR
1770   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
1771 #endif
1772   if( ms>0 ){
1773     sqlite3_busy_handler(db, (int(*)(void*,int))sqliteDefaultBusyCallback,
1774                              (void*)db);
1775     db->busyTimeout = ms;
1776   }else{
1777     sqlite3_busy_handler(db, 0, 0);
1778   }
1779   return SQLITE_OK;
1780 }
1781 
1782 /*
1783 ** Cause any pending operation to stop at its earliest opportunity.
1784 */
1785 void sqlite3_interrupt(sqlite3 *db){
1786 #ifdef SQLITE_ENABLE_API_ARMOR
1787   if( !sqlite3SafetyCheckOk(db) && (db==0 || db->magic!=SQLITE_MAGIC_ZOMBIE) ){
1788     (void)SQLITE_MISUSE_BKPT;
1789     return;
1790   }
1791 #endif
1792   AtomicStore(&db->u1.isInterrupted, 1);
1793 }
1794 
1795 
1796 /*
1797 ** This function is exactly the same as sqlite3_create_function(), except
1798 ** that it is designed to be called by internal code. The difference is
1799 ** that if a malloc() fails in sqlite3_create_function(), an error code
1800 ** is returned and the mallocFailed flag cleared.
1801 */
1802 int sqlite3CreateFunc(
1803   sqlite3 *db,
1804   const char *zFunctionName,
1805   int nArg,
1806   int enc,
1807   void *pUserData,
1808   void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
1809   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
1810   void (*xFinal)(sqlite3_context*),
1811   void (*xValue)(sqlite3_context*),
1812   void (*xInverse)(sqlite3_context*,int,sqlite3_value **),
1813   FuncDestructor *pDestructor
1814 ){
1815   FuncDef *p;
1816   int nName;
1817   int extraFlags;
1818 
1819   assert( sqlite3_mutex_held(db->mutex) );
1820   assert( xValue==0 || xSFunc==0 );
1821   if( zFunctionName==0                /* Must have a valid name */
1822    || (xSFunc!=0 && xFinal!=0)        /* Not both xSFunc and xFinal */
1823    || ((xFinal==0)!=(xStep==0))       /* Both or neither of xFinal and xStep */
1824    || ((xValue==0)!=(xInverse==0))    /* Both or neither of xValue, xInverse */
1825    || (nArg<-1 || nArg>SQLITE_MAX_FUNCTION_ARG)
1826    || (255<(nName = sqlite3Strlen30( zFunctionName)))
1827   ){
1828     return SQLITE_MISUSE_BKPT;
1829   }
1830 
1831   assert( SQLITE_FUNC_CONSTANT==SQLITE_DETERMINISTIC );
1832   assert( SQLITE_FUNC_DIRECT==SQLITE_DIRECTONLY );
1833   extraFlags = enc &  (SQLITE_DETERMINISTIC|SQLITE_DIRECTONLY|
1834                        SQLITE_SUBTYPE|SQLITE_INNOCUOUS);
1835   enc &= (SQLITE_FUNC_ENCMASK|SQLITE_ANY);
1836 
1837   /* The SQLITE_INNOCUOUS flag is the same bit as SQLITE_FUNC_UNSAFE.  But
1838   ** the meaning is inverted.  So flip the bit. */
1839   assert( SQLITE_FUNC_UNSAFE==SQLITE_INNOCUOUS );
1840   extraFlags ^= SQLITE_FUNC_UNSAFE;
1841 
1842 
1843 #ifndef SQLITE_OMIT_UTF16
1844   /* If SQLITE_UTF16 is specified as the encoding type, transform this
1845   ** to one of SQLITE_UTF16LE or SQLITE_UTF16BE using the
1846   ** SQLITE_UTF16NATIVE macro. SQLITE_UTF16 is not used internally.
1847   **
1848   ** If SQLITE_ANY is specified, add three versions of the function
1849   ** to the hash table.
1850   */
1851   if( enc==SQLITE_UTF16 ){
1852     enc = SQLITE_UTF16NATIVE;
1853   }else if( enc==SQLITE_ANY ){
1854     int rc;
1855     rc = sqlite3CreateFunc(db, zFunctionName, nArg,
1856          (SQLITE_UTF8|extraFlags)^SQLITE_FUNC_UNSAFE,
1857          pUserData, xSFunc, xStep, xFinal, xValue, xInverse, pDestructor);
1858     if( rc==SQLITE_OK ){
1859       rc = sqlite3CreateFunc(db, zFunctionName, nArg,
1860            (SQLITE_UTF16LE|extraFlags)^SQLITE_FUNC_UNSAFE,
1861            pUserData, xSFunc, xStep, xFinal, xValue, xInverse, pDestructor);
1862     }
1863     if( rc!=SQLITE_OK ){
1864       return rc;
1865     }
1866     enc = SQLITE_UTF16BE;
1867   }
1868 #else
1869   enc = SQLITE_UTF8;
1870 #endif
1871 
1872   /* Check if an existing function is being overridden or deleted. If so,
1873   ** and there are active VMs, then return SQLITE_BUSY. If a function
1874   ** is being overridden/deleted but there are no active VMs, allow the
1875   ** operation to continue but invalidate all precompiled statements.
1876   */
1877   p = sqlite3FindFunction(db, zFunctionName, nArg, (u8)enc, 0);
1878   if( p && (p->funcFlags & SQLITE_FUNC_ENCMASK)==(u32)enc && p->nArg==nArg ){
1879     if( db->nVdbeActive ){
1880       sqlite3ErrorWithMsg(db, SQLITE_BUSY,
1881         "unable to delete/modify user-function due to active statements");
1882       assert( !db->mallocFailed );
1883       return SQLITE_BUSY;
1884     }else{
1885       sqlite3ExpirePreparedStatements(db, 0);
1886     }
1887   }
1888 
1889   p = sqlite3FindFunction(db, zFunctionName, nArg, (u8)enc, 1);
1890   assert(p || db->mallocFailed);
1891   if( !p ){
1892     return SQLITE_NOMEM_BKPT;
1893   }
1894 
1895   /* If an older version of the function with a configured destructor is
1896   ** being replaced invoke the destructor function here. */
1897   functionDestroy(db, p);
1898 
1899   if( pDestructor ){
1900     pDestructor->nRef++;
1901   }
1902   p->u.pDestructor = pDestructor;
1903   p->funcFlags = (p->funcFlags & SQLITE_FUNC_ENCMASK) | extraFlags;
1904   testcase( p->funcFlags & SQLITE_DETERMINISTIC );
1905   testcase( p->funcFlags & SQLITE_DIRECTONLY );
1906   p->xSFunc = xSFunc ? xSFunc : xStep;
1907   p->xFinalize = xFinal;
1908   p->xValue = xValue;
1909   p->xInverse = xInverse;
1910   p->pUserData = pUserData;
1911   p->nArg = (u16)nArg;
1912   return SQLITE_OK;
1913 }
1914 
1915 /*
1916 ** Worker function used by utf-8 APIs that create new functions:
1917 **
1918 **    sqlite3_create_function()
1919 **    sqlite3_create_function_v2()
1920 **    sqlite3_create_window_function()
1921 */
1922 static int createFunctionApi(
1923   sqlite3 *db,
1924   const char *zFunc,
1925   int nArg,
1926   int enc,
1927   void *p,
1928   void (*xSFunc)(sqlite3_context*,int,sqlite3_value**),
1929   void (*xStep)(sqlite3_context*,int,sqlite3_value**),
1930   void (*xFinal)(sqlite3_context*),
1931   void (*xValue)(sqlite3_context*),
1932   void (*xInverse)(sqlite3_context*,int,sqlite3_value**),
1933   void(*xDestroy)(void*)
1934 ){
1935   int rc = SQLITE_ERROR;
1936   FuncDestructor *pArg = 0;
1937 
1938 #ifdef SQLITE_ENABLE_API_ARMOR
1939   if( !sqlite3SafetyCheckOk(db) ){
1940     return SQLITE_MISUSE_BKPT;
1941   }
1942 #endif
1943   sqlite3_mutex_enter(db->mutex);
1944   if( xDestroy ){
1945     pArg = (FuncDestructor *)sqlite3Malloc(sizeof(FuncDestructor));
1946     if( !pArg ){
1947       sqlite3OomFault(db);
1948       xDestroy(p);
1949       goto out;
1950     }
1951     pArg->nRef = 0;
1952     pArg->xDestroy = xDestroy;
1953     pArg->pUserData = p;
1954   }
1955   rc = sqlite3CreateFunc(db, zFunc, nArg, enc, p,
1956       xSFunc, xStep, xFinal, xValue, xInverse, pArg
1957   );
1958   if( pArg && pArg->nRef==0 ){
1959     assert( rc!=SQLITE_OK );
1960     xDestroy(p);
1961     sqlite3_free(pArg);
1962   }
1963 
1964  out:
1965   rc = sqlite3ApiExit(db, rc);
1966   sqlite3_mutex_leave(db->mutex);
1967   return rc;
1968 }
1969 
1970 /*
1971 ** Create new user functions.
1972 */
1973 int sqlite3_create_function(
1974   sqlite3 *db,
1975   const char *zFunc,
1976   int nArg,
1977   int enc,
1978   void *p,
1979   void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
1980   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
1981   void (*xFinal)(sqlite3_context*)
1982 ){
1983   return createFunctionApi(db, zFunc, nArg, enc, p, xSFunc, xStep,
1984                                     xFinal, 0, 0, 0);
1985 }
1986 int sqlite3_create_function_v2(
1987   sqlite3 *db,
1988   const char *zFunc,
1989   int nArg,
1990   int enc,
1991   void *p,
1992   void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
1993   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
1994   void (*xFinal)(sqlite3_context*),
1995   void (*xDestroy)(void *)
1996 ){
1997   return createFunctionApi(db, zFunc, nArg, enc, p, xSFunc, xStep,
1998                                     xFinal, 0, 0, xDestroy);
1999 }
2000 int sqlite3_create_window_function(
2001   sqlite3 *db,
2002   const char *zFunc,
2003   int nArg,
2004   int enc,
2005   void *p,
2006   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
2007   void (*xFinal)(sqlite3_context*),
2008   void (*xValue)(sqlite3_context*),
2009   void (*xInverse)(sqlite3_context*,int,sqlite3_value **),
2010   void (*xDestroy)(void *)
2011 ){
2012   return createFunctionApi(db, zFunc, nArg, enc, p, 0, xStep,
2013                                     xFinal, xValue, xInverse, xDestroy);
2014 }
2015 
2016 #ifndef SQLITE_OMIT_UTF16
2017 int sqlite3_create_function16(
2018   sqlite3 *db,
2019   const void *zFunctionName,
2020   int nArg,
2021   int eTextRep,
2022   void *p,
2023   void (*xSFunc)(sqlite3_context*,int,sqlite3_value**),
2024   void (*xStep)(sqlite3_context*,int,sqlite3_value**),
2025   void (*xFinal)(sqlite3_context*)
2026 ){
2027   int rc;
2028   char *zFunc8;
2029 
2030 #ifdef SQLITE_ENABLE_API_ARMOR
2031   if( !sqlite3SafetyCheckOk(db) || zFunctionName==0 ) return SQLITE_MISUSE_BKPT;
2032 #endif
2033   sqlite3_mutex_enter(db->mutex);
2034   assert( !db->mallocFailed );
2035   zFunc8 = sqlite3Utf16to8(db, zFunctionName, -1, SQLITE_UTF16NATIVE);
2036   rc = sqlite3CreateFunc(db, zFunc8, nArg, eTextRep, p, xSFunc,xStep,xFinal,0,0,0);
2037   sqlite3DbFree(db, zFunc8);
2038   rc = sqlite3ApiExit(db, rc);
2039   sqlite3_mutex_leave(db->mutex);
2040   return rc;
2041 }
2042 #endif
2043 
2044 
2045 /*
2046 ** The following is the implementation of an SQL function that always
2047 ** fails with an error message stating that the function is used in the
2048 ** wrong context.  The sqlite3_overload_function() API might construct
2049 ** SQL function that use this routine so that the functions will exist
2050 ** for name resolution but are actually overloaded by the xFindFunction
2051 ** method of virtual tables.
2052 */
2053 static void sqlite3InvalidFunction(
2054   sqlite3_context *context,  /* The function calling context */
2055   int NotUsed,               /* Number of arguments to the function */
2056   sqlite3_value **NotUsed2   /* Value of each argument */
2057 ){
2058   const char *zName = (const char*)sqlite3_user_data(context);
2059   char *zErr;
2060   UNUSED_PARAMETER2(NotUsed, NotUsed2);
2061   zErr = sqlite3_mprintf(
2062       "unable to use function %s in the requested context", zName);
2063   sqlite3_result_error(context, zErr, -1);
2064   sqlite3_free(zErr);
2065 }
2066 
2067 /*
2068 ** Declare that a function has been overloaded by a virtual table.
2069 **
2070 ** If the function already exists as a regular global function, then
2071 ** this routine is a no-op.  If the function does not exist, then create
2072 ** a new one that always throws a run-time error.
2073 **
2074 ** When virtual tables intend to provide an overloaded function, they
2075 ** should call this routine to make sure the global function exists.
2076 ** A global function must exist in order for name resolution to work
2077 ** properly.
2078 */
2079 int sqlite3_overload_function(
2080   sqlite3 *db,
2081   const char *zName,
2082   int nArg
2083 ){
2084   int rc;
2085   char *zCopy;
2086 
2087 #ifdef SQLITE_ENABLE_API_ARMOR
2088   if( !sqlite3SafetyCheckOk(db) || zName==0 || nArg<-2 ){
2089     return SQLITE_MISUSE_BKPT;
2090   }
2091 #endif
2092   sqlite3_mutex_enter(db->mutex);
2093   rc = sqlite3FindFunction(db, zName, nArg, SQLITE_UTF8, 0)!=0;
2094   sqlite3_mutex_leave(db->mutex);
2095   if( rc ) return SQLITE_OK;
2096   zCopy = sqlite3_mprintf(zName);
2097   if( zCopy==0 ) return SQLITE_NOMEM;
2098   return sqlite3_create_function_v2(db, zName, nArg, SQLITE_UTF8,
2099                            zCopy, sqlite3InvalidFunction, 0, 0, sqlite3_free);
2100 }
2101 
2102 #ifndef SQLITE_OMIT_TRACE
2103 /*
2104 ** Register a trace function.  The pArg from the previously registered trace
2105 ** is returned.
2106 **
2107 ** A NULL trace function means that no tracing is executes.  A non-NULL
2108 ** trace is a pointer to a function that is invoked at the start of each
2109 ** SQL statement.
2110 */
2111 #ifndef SQLITE_OMIT_DEPRECATED
2112 void *sqlite3_trace(sqlite3 *db, void(*xTrace)(void*,const char*), void *pArg){
2113   void *pOld;
2114 
2115 #ifdef SQLITE_ENABLE_API_ARMOR
2116   if( !sqlite3SafetyCheckOk(db) ){
2117     (void)SQLITE_MISUSE_BKPT;
2118     return 0;
2119   }
2120 #endif
2121   sqlite3_mutex_enter(db->mutex);
2122   pOld = db->pTraceArg;
2123   db->mTrace = xTrace ? SQLITE_TRACE_LEGACY : 0;
2124   db->trace.xLegacy = xTrace;
2125   db->pTraceArg = pArg;
2126   sqlite3_mutex_leave(db->mutex);
2127   return pOld;
2128 }
2129 #endif /* SQLITE_OMIT_DEPRECATED */
2130 
2131 /* Register a trace callback using the version-2 interface.
2132 */
2133 int sqlite3_trace_v2(
2134   sqlite3 *db,                               /* Trace this connection */
2135   unsigned mTrace,                           /* Mask of events to be traced */
2136   int(*xTrace)(unsigned,void*,void*,void*),  /* Callback to invoke */
2137   void *pArg                                 /* Context */
2138 ){
2139 #ifdef SQLITE_ENABLE_API_ARMOR
2140   if( !sqlite3SafetyCheckOk(db) ){
2141     return SQLITE_MISUSE_BKPT;
2142   }
2143 #endif
2144   sqlite3_mutex_enter(db->mutex);
2145   if( mTrace==0 ) xTrace = 0;
2146   if( xTrace==0 ) mTrace = 0;
2147   db->mTrace = mTrace;
2148   db->trace.xV2 = xTrace;
2149   db->pTraceArg = pArg;
2150   sqlite3_mutex_leave(db->mutex);
2151   return SQLITE_OK;
2152 }
2153 
2154 #ifndef SQLITE_OMIT_DEPRECATED
2155 /*
2156 ** Register a profile function.  The pArg from the previously registered
2157 ** profile function is returned.
2158 **
2159 ** A NULL profile function means that no profiling is executes.  A non-NULL
2160 ** profile is a pointer to a function that is invoked at the conclusion of
2161 ** each SQL statement that is run.
2162 */
2163 void *sqlite3_profile(
2164   sqlite3 *db,
2165   void (*xProfile)(void*,const char*,sqlite_uint64),
2166   void *pArg
2167 ){
2168   void *pOld;
2169 
2170 #ifdef SQLITE_ENABLE_API_ARMOR
2171   if( !sqlite3SafetyCheckOk(db) ){
2172     (void)SQLITE_MISUSE_BKPT;
2173     return 0;
2174   }
2175 #endif
2176   sqlite3_mutex_enter(db->mutex);
2177   pOld = db->pProfileArg;
2178   db->xProfile = xProfile;
2179   db->pProfileArg = pArg;
2180   db->mTrace &= SQLITE_TRACE_NONLEGACY_MASK;
2181   if( db->xProfile ) db->mTrace |= SQLITE_TRACE_XPROFILE;
2182   sqlite3_mutex_leave(db->mutex);
2183   return pOld;
2184 }
2185 #endif /* SQLITE_OMIT_DEPRECATED */
2186 #endif /* SQLITE_OMIT_TRACE */
2187 
2188 /*
2189 ** Register a function to be invoked when a transaction commits.
2190 ** If the invoked function returns non-zero, then the commit becomes a
2191 ** rollback.
2192 */
2193 void *sqlite3_commit_hook(
2194   sqlite3 *db,              /* Attach the hook to this database */
2195   int (*xCallback)(void*),  /* Function to invoke on each commit */
2196   void *pArg                /* Argument to the function */
2197 ){
2198   void *pOld;
2199 
2200 #ifdef SQLITE_ENABLE_API_ARMOR
2201   if( !sqlite3SafetyCheckOk(db) ){
2202     (void)SQLITE_MISUSE_BKPT;
2203     return 0;
2204   }
2205 #endif
2206   sqlite3_mutex_enter(db->mutex);
2207   pOld = db->pCommitArg;
2208   db->xCommitCallback = xCallback;
2209   db->pCommitArg = pArg;
2210   sqlite3_mutex_leave(db->mutex);
2211   return pOld;
2212 }
2213 
2214 /*
2215 ** Register a callback to be invoked each time a row is updated,
2216 ** inserted or deleted using this database connection.
2217 */
2218 void *sqlite3_update_hook(
2219   sqlite3 *db,              /* Attach the hook to this database */
2220   void (*xCallback)(void*,int,char const *,char const *,sqlite_int64),
2221   void *pArg                /* Argument to the function */
2222 ){
2223   void *pRet;
2224 
2225 #ifdef SQLITE_ENABLE_API_ARMOR
2226   if( !sqlite3SafetyCheckOk(db) ){
2227     (void)SQLITE_MISUSE_BKPT;
2228     return 0;
2229   }
2230 #endif
2231   sqlite3_mutex_enter(db->mutex);
2232   pRet = db->pUpdateArg;
2233   db->xUpdateCallback = xCallback;
2234   db->pUpdateArg = pArg;
2235   sqlite3_mutex_leave(db->mutex);
2236   return pRet;
2237 }
2238 
2239 /*
2240 ** Register a callback to be invoked each time a transaction is rolled
2241 ** back by this database connection.
2242 */
2243 void *sqlite3_rollback_hook(
2244   sqlite3 *db,              /* Attach the hook to this database */
2245   void (*xCallback)(void*), /* Callback function */
2246   void *pArg                /* Argument to the function */
2247 ){
2248   void *pRet;
2249 
2250 #ifdef SQLITE_ENABLE_API_ARMOR
2251   if( !sqlite3SafetyCheckOk(db) ){
2252     (void)SQLITE_MISUSE_BKPT;
2253     return 0;
2254   }
2255 #endif
2256   sqlite3_mutex_enter(db->mutex);
2257   pRet = db->pRollbackArg;
2258   db->xRollbackCallback = xCallback;
2259   db->pRollbackArg = pArg;
2260   sqlite3_mutex_leave(db->mutex);
2261   return pRet;
2262 }
2263 
2264 #ifdef SQLITE_ENABLE_PREUPDATE_HOOK
2265 /*
2266 ** Register a callback to be invoked each time a row is updated,
2267 ** inserted or deleted using this database connection.
2268 */
2269 void *sqlite3_preupdate_hook(
2270   sqlite3 *db,              /* Attach the hook to this database */
2271   void(*xCallback)(         /* Callback function */
2272     void*,sqlite3*,int,char const*,char const*,sqlite3_int64,sqlite3_int64),
2273   void *pArg                /* First callback argument */
2274 ){
2275   void *pRet;
2276   sqlite3_mutex_enter(db->mutex);
2277   pRet = db->pPreUpdateArg;
2278   db->xPreUpdateCallback = xCallback;
2279   db->pPreUpdateArg = pArg;
2280   sqlite3_mutex_leave(db->mutex);
2281   return pRet;
2282 }
2283 #endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
2284 
2285 #ifndef SQLITE_OMIT_WAL
2286 /*
2287 ** The sqlite3_wal_hook() callback registered by sqlite3_wal_autocheckpoint().
2288 ** Invoke sqlite3_wal_checkpoint if the number of frames in the log file
2289 ** is greater than sqlite3.pWalArg cast to an integer (the value configured by
2290 ** wal_autocheckpoint()).
2291 */
2292 int sqlite3WalDefaultHook(
2293   void *pClientData,     /* Argument */
2294   sqlite3 *db,           /* Connection */
2295   const char *zDb,       /* Database */
2296   int nFrame             /* Size of WAL */
2297 ){
2298   if( nFrame>=SQLITE_PTR_TO_INT(pClientData) ){
2299     sqlite3BeginBenignMalloc();
2300     sqlite3_wal_checkpoint(db, zDb);
2301     sqlite3EndBenignMalloc();
2302   }
2303   return SQLITE_OK;
2304 }
2305 #endif /* SQLITE_OMIT_WAL */
2306 
2307 /*
2308 ** Configure an sqlite3_wal_hook() callback to automatically checkpoint
2309 ** a database after committing a transaction if there are nFrame or
2310 ** more frames in the log file. Passing zero or a negative value as the
2311 ** nFrame parameter disables automatic checkpoints entirely.
2312 **
2313 ** The callback registered by this function replaces any existing callback
2314 ** registered using sqlite3_wal_hook(). Likewise, registering a callback
2315 ** using sqlite3_wal_hook() disables the automatic checkpoint mechanism
2316 ** configured by this function.
2317 */
2318 int sqlite3_wal_autocheckpoint(sqlite3 *db, int nFrame){
2319 #ifdef SQLITE_OMIT_WAL
2320   UNUSED_PARAMETER(db);
2321   UNUSED_PARAMETER(nFrame);
2322 #else
2323 #ifdef SQLITE_ENABLE_API_ARMOR
2324   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
2325 #endif
2326   if( nFrame>0 ){
2327     sqlite3_wal_hook(db, sqlite3WalDefaultHook, SQLITE_INT_TO_PTR(nFrame));
2328   }else{
2329     sqlite3_wal_hook(db, 0, 0);
2330   }
2331 #endif
2332   return SQLITE_OK;
2333 }
2334 
2335 /*
2336 ** Register a callback to be invoked each time a transaction is written
2337 ** into the write-ahead-log by this database connection.
2338 */
2339 void *sqlite3_wal_hook(
2340   sqlite3 *db,                    /* Attach the hook to this db handle */
2341   int(*xCallback)(void *, sqlite3*, const char*, int),
2342   void *pArg                      /* First argument passed to xCallback() */
2343 ){
2344 #ifndef SQLITE_OMIT_WAL
2345   void *pRet;
2346 #ifdef SQLITE_ENABLE_API_ARMOR
2347   if( !sqlite3SafetyCheckOk(db) ){
2348     (void)SQLITE_MISUSE_BKPT;
2349     return 0;
2350   }
2351 #endif
2352   sqlite3_mutex_enter(db->mutex);
2353   pRet = db->pWalArg;
2354   db->xWalCallback = xCallback;
2355   db->pWalArg = pArg;
2356   sqlite3_mutex_leave(db->mutex);
2357   return pRet;
2358 #else
2359   return 0;
2360 #endif
2361 }
2362 
2363 /*
2364 ** Checkpoint database zDb.
2365 */
2366 int sqlite3_wal_checkpoint_v2(
2367   sqlite3 *db,                    /* Database handle */
2368   const char *zDb,                /* Name of attached database (or NULL) */
2369   int eMode,                      /* SQLITE_CHECKPOINT_* value */
2370   int *pnLog,                     /* OUT: Size of WAL log in frames */
2371   int *pnCkpt                     /* OUT: Total number of frames checkpointed */
2372 ){
2373 #ifdef SQLITE_OMIT_WAL
2374   return SQLITE_OK;
2375 #else
2376   int rc;                         /* Return code */
2377   int iDb = SQLITE_MAX_ATTACHED;  /* sqlite3.aDb[] index of db to checkpoint */
2378 
2379 #ifdef SQLITE_ENABLE_API_ARMOR
2380   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
2381 #endif
2382 
2383   /* Initialize the output variables to -1 in case an error occurs. */
2384   if( pnLog ) *pnLog = -1;
2385   if( pnCkpt ) *pnCkpt = -1;
2386 
2387   assert( SQLITE_CHECKPOINT_PASSIVE==0 );
2388   assert( SQLITE_CHECKPOINT_FULL==1 );
2389   assert( SQLITE_CHECKPOINT_RESTART==2 );
2390   assert( SQLITE_CHECKPOINT_TRUNCATE==3 );
2391   if( eMode<SQLITE_CHECKPOINT_PASSIVE || eMode>SQLITE_CHECKPOINT_TRUNCATE ){
2392     /* EVIDENCE-OF: R-03996-12088 The M parameter must be a valid checkpoint
2393     ** mode: */
2394     return SQLITE_MISUSE;
2395   }
2396 
2397   sqlite3_mutex_enter(db->mutex);
2398   if( zDb && zDb[0] ){
2399     iDb = sqlite3FindDbName(db, zDb);
2400   }
2401   if( iDb<0 ){
2402     rc = SQLITE_ERROR;
2403     sqlite3ErrorWithMsg(db, SQLITE_ERROR, "unknown database: %s", zDb);
2404   }else{
2405     db->busyHandler.nBusy = 0;
2406     rc = sqlite3Checkpoint(db, iDb, eMode, pnLog, pnCkpt);
2407     sqlite3Error(db, rc);
2408   }
2409   rc = sqlite3ApiExit(db, rc);
2410 
2411   /* If there are no active statements, clear the interrupt flag at this
2412   ** point.  */
2413   if( db->nVdbeActive==0 ){
2414     AtomicStore(&db->u1.isInterrupted, 0);
2415   }
2416 
2417   sqlite3_mutex_leave(db->mutex);
2418   return rc;
2419 #endif
2420 }
2421 
2422 
2423 /*
2424 ** Checkpoint database zDb. If zDb is NULL, or if the buffer zDb points
2425 ** to contains a zero-length string, all attached databases are
2426 ** checkpointed.
2427 */
2428 int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb){
2429   /* EVIDENCE-OF: R-41613-20553 The sqlite3_wal_checkpoint(D,X) is equivalent to
2430   ** sqlite3_wal_checkpoint_v2(D,X,SQLITE_CHECKPOINT_PASSIVE,0,0). */
2431   return sqlite3_wal_checkpoint_v2(db,zDb,SQLITE_CHECKPOINT_PASSIVE,0,0);
2432 }
2433 
2434 #ifndef SQLITE_OMIT_WAL
2435 /*
2436 ** Run a checkpoint on database iDb. This is a no-op if database iDb is
2437 ** not currently open in WAL mode.
2438 **
2439 ** If a transaction is open on the database being checkpointed, this
2440 ** function returns SQLITE_LOCKED and a checkpoint is not attempted. If
2441 ** an error occurs while running the checkpoint, an SQLite error code is
2442 ** returned (i.e. SQLITE_IOERR). Otherwise, SQLITE_OK.
2443 **
2444 ** The mutex on database handle db should be held by the caller. The mutex
2445 ** associated with the specific b-tree being checkpointed is taken by
2446 ** this function while the checkpoint is running.
2447 **
2448 ** If iDb is passed SQLITE_MAX_ATTACHED, then all attached databases are
2449 ** checkpointed. If an error is encountered it is returned immediately -
2450 ** no attempt is made to checkpoint any remaining databases.
2451 **
2452 ** Parameter eMode is one of SQLITE_CHECKPOINT_PASSIVE, FULL, RESTART
2453 ** or TRUNCATE.
2454 */
2455 int sqlite3Checkpoint(sqlite3 *db, int iDb, int eMode, int *pnLog, int *pnCkpt){
2456   int rc = SQLITE_OK;             /* Return code */
2457   int i;                          /* Used to iterate through attached dbs */
2458   int bBusy = 0;                  /* True if SQLITE_BUSY has been encountered */
2459 
2460   assert( sqlite3_mutex_held(db->mutex) );
2461   assert( !pnLog || *pnLog==-1 );
2462   assert( !pnCkpt || *pnCkpt==-1 );
2463 
2464   for(i=0; i<db->nDb && rc==SQLITE_OK; i++){
2465     if( i==iDb || iDb==SQLITE_MAX_ATTACHED ){
2466       rc = sqlite3BtreeCheckpoint(db->aDb[i].pBt, eMode, pnLog, pnCkpt);
2467       pnLog = 0;
2468       pnCkpt = 0;
2469       if( rc==SQLITE_BUSY ){
2470         bBusy = 1;
2471         rc = SQLITE_OK;
2472       }
2473     }
2474   }
2475 
2476   return (rc==SQLITE_OK && bBusy) ? SQLITE_BUSY : rc;
2477 }
2478 #endif /* SQLITE_OMIT_WAL */
2479 
2480 /*
2481 ** This function returns true if main-memory should be used instead of
2482 ** a temporary file for transient pager files and statement journals.
2483 ** The value returned depends on the value of db->temp_store (runtime
2484 ** parameter) and the compile time value of SQLITE_TEMP_STORE. The
2485 ** following table describes the relationship between these two values
2486 ** and this functions return value.
2487 **
2488 **   SQLITE_TEMP_STORE     db->temp_store     Location of temporary database
2489 **   -----------------     --------------     ------------------------------
2490 **   0                     any                file      (return 0)
2491 **   1                     1                  file      (return 0)
2492 **   1                     2                  memory    (return 1)
2493 **   1                     0                  file      (return 0)
2494 **   2                     1                  file      (return 0)
2495 **   2                     2                  memory    (return 1)
2496 **   2                     0                  memory    (return 1)
2497 **   3                     any                memory    (return 1)
2498 */
2499 int sqlite3TempInMemory(const sqlite3 *db){
2500 #if SQLITE_TEMP_STORE==1
2501   return ( db->temp_store==2 );
2502 #endif
2503 #if SQLITE_TEMP_STORE==2
2504   return ( db->temp_store!=1 );
2505 #endif
2506 #if SQLITE_TEMP_STORE==3
2507   UNUSED_PARAMETER(db);
2508   return 1;
2509 #endif
2510 #if SQLITE_TEMP_STORE<1 || SQLITE_TEMP_STORE>3
2511   UNUSED_PARAMETER(db);
2512   return 0;
2513 #endif
2514 }
2515 
2516 /*
2517 ** Return UTF-8 encoded English language explanation of the most recent
2518 ** error.
2519 */
2520 const char *sqlite3_errmsg(sqlite3 *db){
2521   const char *z;
2522   if( !db ){
2523     return sqlite3ErrStr(SQLITE_NOMEM_BKPT);
2524   }
2525   if( !sqlite3SafetyCheckSickOrOk(db) ){
2526     return sqlite3ErrStr(SQLITE_MISUSE_BKPT);
2527   }
2528   sqlite3_mutex_enter(db->mutex);
2529   if( db->mallocFailed ){
2530     z = sqlite3ErrStr(SQLITE_NOMEM_BKPT);
2531   }else{
2532     testcase( db->pErr==0 );
2533     z = db->errCode ? (char*)sqlite3_value_text(db->pErr) : 0;
2534     assert( !db->mallocFailed );
2535     if( z==0 ){
2536       z = sqlite3ErrStr(db->errCode);
2537     }
2538   }
2539   sqlite3_mutex_leave(db->mutex);
2540   return z;
2541 }
2542 
2543 #ifndef SQLITE_OMIT_UTF16
2544 /*
2545 ** Return UTF-16 encoded English language explanation of the most recent
2546 ** error.
2547 */
2548 const void *sqlite3_errmsg16(sqlite3 *db){
2549   static const u16 outOfMem[] = {
2550     'o', 'u', 't', ' ', 'o', 'f', ' ', 'm', 'e', 'm', 'o', 'r', 'y', 0
2551   };
2552   static const u16 misuse[] = {
2553     'b', 'a', 'd', ' ', 'p', 'a', 'r', 'a', 'm', 'e', 't', 'e', 'r', ' ',
2554     'o', 'r', ' ', 'o', 't', 'h', 'e', 'r', ' ', 'A', 'P', 'I', ' ',
2555     'm', 'i', 's', 'u', 's', 'e', 0
2556   };
2557 
2558   const void *z;
2559   if( !db ){
2560     return (void *)outOfMem;
2561   }
2562   if( !sqlite3SafetyCheckSickOrOk(db) ){
2563     return (void *)misuse;
2564   }
2565   sqlite3_mutex_enter(db->mutex);
2566   if( db->mallocFailed ){
2567     z = (void *)outOfMem;
2568   }else{
2569     z = sqlite3_value_text16(db->pErr);
2570     if( z==0 ){
2571       sqlite3ErrorWithMsg(db, db->errCode, sqlite3ErrStr(db->errCode));
2572       z = sqlite3_value_text16(db->pErr);
2573     }
2574     /* A malloc() may have failed within the call to sqlite3_value_text16()
2575     ** above. If this is the case, then the db->mallocFailed flag needs to
2576     ** be cleared before returning. Do this directly, instead of via
2577     ** sqlite3ApiExit(), to avoid setting the database handle error message.
2578     */
2579     sqlite3OomClear(db);
2580   }
2581   sqlite3_mutex_leave(db->mutex);
2582   return z;
2583 }
2584 #endif /* SQLITE_OMIT_UTF16 */
2585 
2586 /*
2587 ** Return the most recent error code generated by an SQLite routine. If NULL is
2588 ** passed to this function, we assume a malloc() failed during sqlite3_open().
2589 */
2590 int sqlite3_errcode(sqlite3 *db){
2591   if( db && !sqlite3SafetyCheckSickOrOk(db) ){
2592     return SQLITE_MISUSE_BKPT;
2593   }
2594   if( !db || db->mallocFailed ){
2595     return SQLITE_NOMEM_BKPT;
2596   }
2597   return db->errCode & db->errMask;
2598 }
2599 int sqlite3_extended_errcode(sqlite3 *db){
2600   if( db && !sqlite3SafetyCheckSickOrOk(db) ){
2601     return SQLITE_MISUSE_BKPT;
2602   }
2603   if( !db || db->mallocFailed ){
2604     return SQLITE_NOMEM_BKPT;
2605   }
2606   return db->errCode;
2607 }
2608 int sqlite3_system_errno(sqlite3 *db){
2609   return db ? db->iSysErrno : 0;
2610 }
2611 
2612 /*
2613 ** Return a string that describes the kind of error specified in the
2614 ** argument.  For now, this simply calls the internal sqlite3ErrStr()
2615 ** function.
2616 */
2617 const char *sqlite3_errstr(int rc){
2618   return sqlite3ErrStr(rc);
2619 }
2620 
2621 /*
2622 ** Create a new collating function for database "db".  The name is zName
2623 ** and the encoding is enc.
2624 */
2625 static int createCollation(
2626   sqlite3* db,
2627   const char *zName,
2628   u8 enc,
2629   void* pCtx,
2630   int(*xCompare)(void*,int,const void*,int,const void*),
2631   void(*xDel)(void*)
2632 ){
2633   CollSeq *pColl;
2634   int enc2;
2635 
2636   assert( sqlite3_mutex_held(db->mutex) );
2637 
2638   /* If SQLITE_UTF16 is specified as the encoding type, transform this
2639   ** to one of SQLITE_UTF16LE or SQLITE_UTF16BE using the
2640   ** SQLITE_UTF16NATIVE macro. SQLITE_UTF16 is not used internally.
2641   */
2642   enc2 = enc;
2643   testcase( enc2==SQLITE_UTF16 );
2644   testcase( enc2==SQLITE_UTF16_ALIGNED );
2645   if( enc2==SQLITE_UTF16 || enc2==SQLITE_UTF16_ALIGNED ){
2646     enc2 = SQLITE_UTF16NATIVE;
2647   }
2648   if( enc2<SQLITE_UTF8 || enc2>SQLITE_UTF16BE ){
2649     return SQLITE_MISUSE_BKPT;
2650   }
2651 
2652   /* Check if this call is removing or replacing an existing collation
2653   ** sequence. If so, and there are active VMs, return busy. If there
2654   ** are no active VMs, invalidate any pre-compiled statements.
2655   */
2656   pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, 0);
2657   if( pColl && pColl->xCmp ){
2658     if( db->nVdbeActive ){
2659       sqlite3ErrorWithMsg(db, SQLITE_BUSY,
2660         "unable to delete/modify collation sequence due to active statements");
2661       return SQLITE_BUSY;
2662     }
2663     sqlite3ExpirePreparedStatements(db, 0);
2664 
2665     /* If collation sequence pColl was created directly by a call to
2666     ** sqlite3_create_collation, and not generated by synthCollSeq(),
2667     ** then any copies made by synthCollSeq() need to be invalidated.
2668     ** Also, collation destructor - CollSeq.xDel() - function may need
2669     ** to be called.
2670     */
2671     if( (pColl->enc & ~SQLITE_UTF16_ALIGNED)==enc2 ){
2672       CollSeq *aColl = sqlite3HashFind(&db->aCollSeq, zName);
2673       int j;
2674       for(j=0; j<3; j++){
2675         CollSeq *p = &aColl[j];
2676         if( p->enc==pColl->enc ){
2677           if( p->xDel ){
2678             p->xDel(p->pUser);
2679           }
2680           p->xCmp = 0;
2681         }
2682       }
2683     }
2684   }
2685 
2686   pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, 1);
2687   if( pColl==0 ) return SQLITE_NOMEM_BKPT;
2688   pColl->xCmp = xCompare;
2689   pColl->pUser = pCtx;
2690   pColl->xDel = xDel;
2691   pColl->enc = (u8)(enc2 | (enc & SQLITE_UTF16_ALIGNED));
2692   sqlite3Error(db, SQLITE_OK);
2693   return SQLITE_OK;
2694 }
2695 
2696 
2697 /*
2698 ** This array defines hard upper bounds on limit values.  The
2699 ** initializer must be kept in sync with the SQLITE_LIMIT_*
2700 ** #defines in sqlite3.h.
2701 */
2702 static const int aHardLimit[] = {
2703   SQLITE_MAX_LENGTH,
2704   SQLITE_MAX_SQL_LENGTH,
2705   SQLITE_MAX_COLUMN,
2706   SQLITE_MAX_EXPR_DEPTH,
2707   SQLITE_MAX_COMPOUND_SELECT,
2708   SQLITE_MAX_VDBE_OP,
2709   SQLITE_MAX_FUNCTION_ARG,
2710   SQLITE_MAX_ATTACHED,
2711   SQLITE_MAX_LIKE_PATTERN_LENGTH,
2712   SQLITE_MAX_VARIABLE_NUMBER,      /* IMP: R-38091-32352 */
2713   SQLITE_MAX_TRIGGER_DEPTH,
2714   SQLITE_MAX_WORKER_THREADS,
2715 };
2716 
2717 /*
2718 ** Make sure the hard limits are set to reasonable values
2719 */
2720 #if SQLITE_MAX_LENGTH<100
2721 # error SQLITE_MAX_LENGTH must be at least 100
2722 #endif
2723 #if SQLITE_MAX_SQL_LENGTH<100
2724 # error SQLITE_MAX_SQL_LENGTH must be at least 100
2725 #endif
2726 #if SQLITE_MAX_SQL_LENGTH>SQLITE_MAX_LENGTH
2727 # error SQLITE_MAX_SQL_LENGTH must not be greater than SQLITE_MAX_LENGTH
2728 #endif
2729 #if SQLITE_MAX_COMPOUND_SELECT<2
2730 # error SQLITE_MAX_COMPOUND_SELECT must be at least 2
2731 #endif
2732 #if SQLITE_MAX_VDBE_OP<40
2733 # error SQLITE_MAX_VDBE_OP must be at least 40
2734 #endif
2735 #if SQLITE_MAX_FUNCTION_ARG<0 || SQLITE_MAX_FUNCTION_ARG>127
2736 # error SQLITE_MAX_FUNCTION_ARG must be between 0 and 127
2737 #endif
2738 #if SQLITE_MAX_ATTACHED<0 || SQLITE_MAX_ATTACHED>125
2739 # error SQLITE_MAX_ATTACHED must be between 0 and 125
2740 #endif
2741 #if SQLITE_MAX_LIKE_PATTERN_LENGTH<1
2742 # error SQLITE_MAX_LIKE_PATTERN_LENGTH must be at least 1
2743 #endif
2744 #if SQLITE_MAX_COLUMN>32767
2745 # error SQLITE_MAX_COLUMN must not exceed 32767
2746 #endif
2747 #if SQLITE_MAX_TRIGGER_DEPTH<1
2748 # error SQLITE_MAX_TRIGGER_DEPTH must be at least 1
2749 #endif
2750 #if SQLITE_MAX_WORKER_THREADS<0 || SQLITE_MAX_WORKER_THREADS>50
2751 # error SQLITE_MAX_WORKER_THREADS must be between 0 and 50
2752 #endif
2753 
2754 
2755 /*
2756 ** Change the value of a limit.  Report the old value.
2757 ** If an invalid limit index is supplied, report -1.
2758 ** Make no changes but still report the old value if the
2759 ** new limit is negative.
2760 **
2761 ** A new lower limit does not shrink existing constructs.
2762 ** It merely prevents new constructs that exceed the limit
2763 ** from forming.
2764 */
2765 int sqlite3_limit(sqlite3 *db, int limitId, int newLimit){
2766   int oldLimit;
2767 
2768 #ifdef SQLITE_ENABLE_API_ARMOR
2769   if( !sqlite3SafetyCheckOk(db) ){
2770     (void)SQLITE_MISUSE_BKPT;
2771     return -1;
2772   }
2773 #endif
2774 
2775   /* EVIDENCE-OF: R-30189-54097 For each limit category SQLITE_LIMIT_NAME
2776   ** there is a hard upper bound set at compile-time by a C preprocessor
2777   ** macro called SQLITE_MAX_NAME. (The "_LIMIT_" in the name is changed to
2778   ** "_MAX_".)
2779   */
2780   assert( aHardLimit[SQLITE_LIMIT_LENGTH]==SQLITE_MAX_LENGTH );
2781   assert( aHardLimit[SQLITE_LIMIT_SQL_LENGTH]==SQLITE_MAX_SQL_LENGTH );
2782   assert( aHardLimit[SQLITE_LIMIT_COLUMN]==SQLITE_MAX_COLUMN );
2783   assert( aHardLimit[SQLITE_LIMIT_EXPR_DEPTH]==SQLITE_MAX_EXPR_DEPTH );
2784   assert( aHardLimit[SQLITE_LIMIT_COMPOUND_SELECT]==SQLITE_MAX_COMPOUND_SELECT);
2785   assert( aHardLimit[SQLITE_LIMIT_VDBE_OP]==SQLITE_MAX_VDBE_OP );
2786   assert( aHardLimit[SQLITE_LIMIT_FUNCTION_ARG]==SQLITE_MAX_FUNCTION_ARG );
2787   assert( aHardLimit[SQLITE_LIMIT_ATTACHED]==SQLITE_MAX_ATTACHED );
2788   assert( aHardLimit[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]==
2789                                                SQLITE_MAX_LIKE_PATTERN_LENGTH );
2790   assert( aHardLimit[SQLITE_LIMIT_VARIABLE_NUMBER]==SQLITE_MAX_VARIABLE_NUMBER);
2791   assert( aHardLimit[SQLITE_LIMIT_TRIGGER_DEPTH]==SQLITE_MAX_TRIGGER_DEPTH );
2792   assert( aHardLimit[SQLITE_LIMIT_WORKER_THREADS]==SQLITE_MAX_WORKER_THREADS );
2793   assert( SQLITE_LIMIT_WORKER_THREADS==(SQLITE_N_LIMIT-1) );
2794 
2795 
2796   if( limitId<0 || limitId>=SQLITE_N_LIMIT ){
2797     return -1;
2798   }
2799   oldLimit = db->aLimit[limitId];
2800   if( newLimit>=0 ){                   /* IMP: R-52476-28732 */
2801     if( newLimit>aHardLimit[limitId] ){
2802       newLimit = aHardLimit[limitId];  /* IMP: R-51463-25634 */
2803     }
2804     db->aLimit[limitId] = newLimit;
2805   }
2806   return oldLimit;                     /* IMP: R-53341-35419 */
2807 }
2808 
2809 /*
2810 ** This function is used to parse both URIs and non-URI filenames passed by the
2811 ** user to API functions sqlite3_open() or sqlite3_open_v2(), and for database
2812 ** URIs specified as part of ATTACH statements.
2813 **
2814 ** The first argument to this function is the name of the VFS to use (or
2815 ** a NULL to signify the default VFS) if the URI does not contain a "vfs=xxx"
2816 ** query parameter. The second argument contains the URI (or non-URI filename)
2817 ** itself. When this function is called the *pFlags variable should contain
2818 ** the default flags to open the database handle with. The value stored in
2819 ** *pFlags may be updated before returning if the URI filename contains
2820 ** "cache=xxx" or "mode=xxx" query parameters.
2821 **
2822 ** If successful, SQLITE_OK is returned. In this case *ppVfs is set to point to
2823 ** the VFS that should be used to open the database file. *pzFile is set to
2824 ** point to a buffer containing the name of the file to open.  The value
2825 ** stored in *pzFile is a database name acceptable to sqlite3_uri_parameter()
2826 ** and is in the same format as names created using sqlite3_create_filename().
2827 ** The caller must invoke sqlite3_free_filename() (not sqlite3_free()!) on
2828 ** the value returned in *pzFile to avoid a memory leak.
2829 **
2830 ** If an error occurs, then an SQLite error code is returned and *pzErrMsg
2831 ** may be set to point to a buffer containing an English language error
2832 ** message. It is the responsibility of the caller to eventually release
2833 ** this buffer by calling sqlite3_free().
2834 */
2835 int sqlite3ParseUri(
2836   const char *zDefaultVfs,        /* VFS to use if no "vfs=xxx" query option */
2837   const char *zUri,               /* Nul-terminated URI to parse */
2838   unsigned int *pFlags,           /* IN/OUT: SQLITE_OPEN_XXX flags */
2839   sqlite3_vfs **ppVfs,            /* OUT: VFS to use */
2840   char **pzFile,                  /* OUT: Filename component of URI */
2841   char **pzErrMsg                 /* OUT: Error message (if rc!=SQLITE_OK) */
2842 ){
2843   int rc = SQLITE_OK;
2844   unsigned int flags = *pFlags;
2845   const char *zVfs = zDefaultVfs;
2846   char *zFile;
2847   char c;
2848   int nUri = sqlite3Strlen30(zUri);
2849 
2850   assert( *pzErrMsg==0 );
2851 
2852   if( ((flags & SQLITE_OPEN_URI)             /* IMP: R-48725-32206 */
2853             || sqlite3GlobalConfig.bOpenUri) /* IMP: R-51689-46548 */
2854    && nUri>=5 && memcmp(zUri, "file:", 5)==0 /* IMP: R-57884-37496 */
2855   ){
2856     char *zOpt;
2857     int eState;                   /* Parser state when parsing URI */
2858     int iIn;                      /* Input character index */
2859     int iOut = 0;                 /* Output character index */
2860     u64 nByte = nUri+8;           /* Bytes of space to allocate */
2861 
2862     /* Make sure the SQLITE_OPEN_URI flag is set to indicate to the VFS xOpen
2863     ** method that there may be extra parameters following the file-name.  */
2864     flags |= SQLITE_OPEN_URI;
2865 
2866     for(iIn=0; iIn<nUri; iIn++) nByte += (zUri[iIn]=='&');
2867     zFile = sqlite3_malloc64(nByte);
2868     if( !zFile ) return SQLITE_NOMEM_BKPT;
2869 
2870     memset(zFile, 0, 4);  /* 4-byte of 0x00 is the start of DB name marker */
2871     zFile += 4;
2872 
2873     iIn = 5;
2874 #ifdef SQLITE_ALLOW_URI_AUTHORITY
2875     if( strncmp(zUri+5, "///", 3)==0 ){
2876       iIn = 7;
2877       /* The following condition causes URIs with five leading / characters
2878       ** like file://///host/path to be converted into UNCs like //host/path.
2879       ** The correct URI for that UNC has only two or four leading / characters
2880       ** file://host/path or file:////host/path.  But 5 leading slashes is a
2881       ** common error, we are told, so we handle it as a special case. */
2882       if( strncmp(zUri+7, "///", 3)==0 ){ iIn++; }
2883     }else if( strncmp(zUri+5, "//localhost/", 12)==0 ){
2884       iIn = 16;
2885     }
2886 #else
2887     /* Discard the scheme and authority segments of the URI. */
2888     if( zUri[5]=='/' && zUri[6]=='/' ){
2889       iIn = 7;
2890       while( zUri[iIn] && zUri[iIn]!='/' ) iIn++;
2891       if( iIn!=7 && (iIn!=16 || memcmp("localhost", &zUri[7], 9)) ){
2892         *pzErrMsg = sqlite3_mprintf("invalid uri authority: %.*s",
2893             iIn-7, &zUri[7]);
2894         rc = SQLITE_ERROR;
2895         goto parse_uri_out;
2896       }
2897     }
2898 #endif
2899 
2900     /* Copy the filename and any query parameters into the zFile buffer.
2901     ** Decode %HH escape codes along the way.
2902     **
2903     ** Within this loop, variable eState may be set to 0, 1 or 2, depending
2904     ** on the parsing context. As follows:
2905     **
2906     **   0: Parsing file-name.
2907     **   1: Parsing name section of a name=value query parameter.
2908     **   2: Parsing value section of a name=value query parameter.
2909     */
2910     eState = 0;
2911     while( (c = zUri[iIn])!=0 && c!='#' ){
2912       iIn++;
2913       if( c=='%'
2914        && sqlite3Isxdigit(zUri[iIn])
2915        && sqlite3Isxdigit(zUri[iIn+1])
2916       ){
2917         int octet = (sqlite3HexToInt(zUri[iIn++]) << 4);
2918         octet += sqlite3HexToInt(zUri[iIn++]);
2919 
2920         assert( octet>=0 && octet<256 );
2921         if( octet==0 ){
2922 #ifndef SQLITE_ENABLE_URI_00_ERROR
2923           /* This branch is taken when "%00" appears within the URI. In this
2924           ** case we ignore all text in the remainder of the path, name or
2925           ** value currently being parsed. So ignore the current character
2926           ** and skip to the next "?", "=" or "&", as appropriate. */
2927           while( (c = zUri[iIn])!=0 && c!='#'
2928               && (eState!=0 || c!='?')
2929               && (eState!=1 || (c!='=' && c!='&'))
2930               && (eState!=2 || c!='&')
2931           ){
2932             iIn++;
2933           }
2934           continue;
2935 #else
2936           /* If ENABLE_URI_00_ERROR is defined, "%00" in a URI is an error. */
2937           *pzErrMsg = sqlite3_mprintf("unexpected %%00 in uri");
2938           rc = SQLITE_ERROR;
2939           goto parse_uri_out;
2940 #endif
2941         }
2942         c = octet;
2943       }else if( eState==1 && (c=='&' || c=='=') ){
2944         if( zFile[iOut-1]==0 ){
2945           /* An empty option name. Ignore this option altogether. */
2946           while( zUri[iIn] && zUri[iIn]!='#' && zUri[iIn-1]!='&' ) iIn++;
2947           continue;
2948         }
2949         if( c=='&' ){
2950           zFile[iOut++] = '\0';
2951         }else{
2952           eState = 2;
2953         }
2954         c = 0;
2955       }else if( (eState==0 && c=='?') || (eState==2 && c=='&') ){
2956         c = 0;
2957         eState = 1;
2958       }
2959       zFile[iOut++] = c;
2960     }
2961     if( eState==1 ) zFile[iOut++] = '\0';
2962     memset(zFile+iOut, 0, 4); /* end-of-options + empty journal filenames */
2963 
2964     /* Check if there were any options specified that should be interpreted
2965     ** here. Options that are interpreted here include "vfs" and those that
2966     ** correspond to flags that may be passed to the sqlite3_open_v2()
2967     ** method. */
2968     zOpt = &zFile[sqlite3Strlen30(zFile)+1];
2969     while( zOpt[0] ){
2970       int nOpt = sqlite3Strlen30(zOpt);
2971       char *zVal = &zOpt[nOpt+1];
2972       int nVal = sqlite3Strlen30(zVal);
2973 
2974       if( nOpt==3 && memcmp("vfs", zOpt, 3)==0 ){
2975         zVfs = zVal;
2976       }else{
2977         struct OpenMode {
2978           const char *z;
2979           int mode;
2980         } *aMode = 0;
2981         char *zModeType = 0;
2982         int mask = 0;
2983         int limit = 0;
2984 
2985         if( nOpt==5 && memcmp("cache", zOpt, 5)==0 ){
2986           static struct OpenMode aCacheMode[] = {
2987             { "shared",  SQLITE_OPEN_SHAREDCACHE },
2988             { "private", SQLITE_OPEN_PRIVATECACHE },
2989             { 0, 0 }
2990           };
2991 
2992           mask = SQLITE_OPEN_SHAREDCACHE|SQLITE_OPEN_PRIVATECACHE;
2993           aMode = aCacheMode;
2994           limit = mask;
2995           zModeType = "cache";
2996         }
2997         if( nOpt==4 && memcmp("mode", zOpt, 4)==0 ){
2998           static struct OpenMode aOpenMode[] = {
2999             { "ro",  SQLITE_OPEN_READONLY },
3000             { "rw",  SQLITE_OPEN_READWRITE },
3001             { "rwc", SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE },
3002             { "memory", SQLITE_OPEN_MEMORY },
3003             { 0, 0 }
3004           };
3005 
3006           mask = SQLITE_OPEN_READONLY | SQLITE_OPEN_READWRITE
3007                    | SQLITE_OPEN_CREATE | SQLITE_OPEN_MEMORY;
3008           aMode = aOpenMode;
3009           limit = mask & flags;
3010           zModeType = "access";
3011         }
3012 
3013         if( aMode ){
3014           int i;
3015           int mode = 0;
3016           for(i=0; aMode[i].z; i++){
3017             const char *z = aMode[i].z;
3018             if( nVal==sqlite3Strlen30(z) && 0==memcmp(zVal, z, nVal) ){
3019               mode = aMode[i].mode;
3020               break;
3021             }
3022           }
3023           if( mode==0 ){
3024             *pzErrMsg = sqlite3_mprintf("no such %s mode: %s", zModeType, zVal);
3025             rc = SQLITE_ERROR;
3026             goto parse_uri_out;
3027           }
3028           if( (mode & ~SQLITE_OPEN_MEMORY)>limit ){
3029             *pzErrMsg = sqlite3_mprintf("%s mode not allowed: %s",
3030                                         zModeType, zVal);
3031             rc = SQLITE_PERM;
3032             goto parse_uri_out;
3033           }
3034           flags = (flags & ~mask) | mode;
3035         }
3036       }
3037 
3038       zOpt = &zVal[nVal+1];
3039     }
3040 
3041   }else{
3042     zFile = sqlite3_malloc64(nUri+8);
3043     if( !zFile ) return SQLITE_NOMEM_BKPT;
3044     memset(zFile, 0, 4);
3045     zFile += 4;
3046     if( nUri ){
3047       memcpy(zFile, zUri, nUri);
3048     }
3049     memset(zFile+nUri, 0, 4);
3050     flags &= ~SQLITE_OPEN_URI;
3051   }
3052 
3053   *ppVfs = sqlite3_vfs_find(zVfs);
3054   if( *ppVfs==0 ){
3055     *pzErrMsg = sqlite3_mprintf("no such vfs: %s", zVfs);
3056     rc = SQLITE_ERROR;
3057   }
3058  parse_uri_out:
3059   if( rc!=SQLITE_OK ){
3060     sqlite3_free_filename(zFile);
3061     zFile = 0;
3062   }
3063   *pFlags = flags;
3064   *pzFile = zFile;
3065   return rc;
3066 }
3067 
3068 /*
3069 ** This routine does the core work of extracting URI parameters from a
3070 ** database filename for the sqlite3_uri_parameter() interface.
3071 */
3072 static const char *uriParameter(const char *zFilename, const char *zParam){
3073   zFilename += sqlite3Strlen30(zFilename) + 1;
3074   while( zFilename[0] ){
3075     int x = strcmp(zFilename, zParam);
3076     zFilename += sqlite3Strlen30(zFilename) + 1;
3077     if( x==0 ) return zFilename;
3078     zFilename += sqlite3Strlen30(zFilename) + 1;
3079   }
3080   return 0;
3081 }
3082 
3083 
3084 
3085 /*
3086 ** This routine does the work of opening a database on behalf of
3087 ** sqlite3_open() and sqlite3_open16(). The database filename "zFilename"
3088 ** is UTF-8 encoded.
3089 */
3090 static int openDatabase(
3091   const char *zFilename, /* Database filename UTF-8 encoded */
3092   sqlite3 **ppDb,        /* OUT: Returned database handle */
3093   unsigned int flags,    /* Operational flags */
3094   const char *zVfs       /* Name of the VFS to use */
3095 ){
3096   sqlite3 *db;                    /* Store allocated handle here */
3097   int rc;                         /* Return code */
3098   int isThreadsafe;               /* True for threadsafe connections */
3099   char *zOpen = 0;                /* Filename argument to pass to BtreeOpen() */
3100   char *zErrMsg = 0;              /* Error message from sqlite3ParseUri() */
3101   int i;                          /* Loop counter */
3102 
3103 #ifdef SQLITE_ENABLE_API_ARMOR
3104   if( ppDb==0 ) return SQLITE_MISUSE_BKPT;
3105 #endif
3106   *ppDb = 0;
3107 #ifndef SQLITE_OMIT_AUTOINIT
3108   rc = sqlite3_initialize();
3109   if( rc ) return rc;
3110 #endif
3111 
3112   if( sqlite3GlobalConfig.bCoreMutex==0 ){
3113     isThreadsafe = 0;
3114   }else if( flags & SQLITE_OPEN_NOMUTEX ){
3115     isThreadsafe = 0;
3116   }else if( flags & SQLITE_OPEN_FULLMUTEX ){
3117     isThreadsafe = 1;
3118   }else{
3119     isThreadsafe = sqlite3GlobalConfig.bFullMutex;
3120   }
3121 
3122   if( flags & SQLITE_OPEN_PRIVATECACHE ){
3123     flags &= ~SQLITE_OPEN_SHAREDCACHE;
3124   }else if( sqlite3GlobalConfig.sharedCacheEnabled ){
3125     flags |= SQLITE_OPEN_SHAREDCACHE;
3126   }
3127 
3128   /* Remove harmful bits from the flags parameter
3129   **
3130   ** The SQLITE_OPEN_NOMUTEX and SQLITE_OPEN_FULLMUTEX flags were
3131   ** dealt with in the previous code block.  Besides these, the only
3132   ** valid input flags for sqlite3_open_v2() are SQLITE_OPEN_READONLY,
3133   ** SQLITE_OPEN_READWRITE, SQLITE_OPEN_CREATE, SQLITE_OPEN_SHAREDCACHE,
3134   ** SQLITE_OPEN_PRIVATECACHE, and some reserved bits.  Silently mask
3135   ** off all other flags.
3136   */
3137   flags &=  ~( SQLITE_OPEN_DELETEONCLOSE |
3138                SQLITE_OPEN_EXCLUSIVE |
3139                SQLITE_OPEN_MAIN_DB |
3140                SQLITE_OPEN_TEMP_DB |
3141                SQLITE_OPEN_TRANSIENT_DB |
3142                SQLITE_OPEN_MAIN_JOURNAL |
3143                SQLITE_OPEN_TEMP_JOURNAL |
3144                SQLITE_OPEN_SUBJOURNAL |
3145                SQLITE_OPEN_SUPER_JOURNAL |
3146                SQLITE_OPEN_NOMUTEX |
3147                SQLITE_OPEN_FULLMUTEX |
3148                SQLITE_OPEN_WAL
3149              );
3150 
3151   /* Allocate the sqlite data structure */
3152   db = sqlite3MallocZero( sizeof(sqlite3) );
3153   if( db==0 ) goto opendb_out;
3154   if( isThreadsafe
3155 #ifdef SQLITE_ENABLE_MULTITHREADED_CHECKS
3156    || sqlite3GlobalConfig.bCoreMutex
3157 #endif
3158   ){
3159     db->mutex = sqlite3MutexAlloc(SQLITE_MUTEX_RECURSIVE);
3160     if( db->mutex==0 ){
3161       sqlite3_free(db);
3162       db = 0;
3163       goto opendb_out;
3164     }
3165     if( isThreadsafe==0 ){
3166       sqlite3MutexWarnOnContention(db->mutex);
3167     }
3168   }
3169   sqlite3_mutex_enter(db->mutex);
3170   db->errMask = 0xff;
3171   db->nDb = 2;
3172   db->magic = SQLITE_MAGIC_BUSY;
3173   db->aDb = db->aDbStatic;
3174   db->lookaside.bDisable = 1;
3175   db->lookaside.sz = 0;
3176 
3177   assert( sizeof(db->aLimit)==sizeof(aHardLimit) );
3178   memcpy(db->aLimit, aHardLimit, sizeof(db->aLimit));
3179   db->aLimit[SQLITE_LIMIT_WORKER_THREADS] = SQLITE_DEFAULT_WORKER_THREADS;
3180   db->autoCommit = 1;
3181   db->nextAutovac = -1;
3182   db->szMmap = sqlite3GlobalConfig.szMmap;
3183   db->nextPagesize = 0;
3184   db->nMaxSorterMmap = 0x7FFFFFFF;
3185   db->flags |= SQLITE_ShortColNames
3186                  | SQLITE_EnableTrigger
3187                  | SQLITE_EnableView
3188                  | SQLITE_CacheSpill
3189 #if !defined(SQLITE_TRUSTED_SCHEMA) || SQLITE_TRUSTED_SCHEMA+0!=0
3190                  | SQLITE_TrustedSchema
3191 #endif
3192 /* The SQLITE_DQS compile-time option determines the default settings
3193 ** for SQLITE_DBCONFIG_DQS_DDL and SQLITE_DBCONFIG_DQS_DML.
3194 **
3195 **    SQLITE_DQS     SQLITE_DBCONFIG_DQS_DDL    SQLITE_DBCONFIG_DQS_DML
3196 **    ----------     -----------------------    -----------------------
3197 **     undefined               on                          on
3198 **         3                   on                          on
3199 **         2                   on                         off
3200 **         1                  off                          on
3201 **         0                  off                         off
3202 **
3203 ** Legacy behavior is 3 (double-quoted string literals are allowed anywhere)
3204 ** and so that is the default.  But developers are encouranged to use
3205 ** -DSQLITE_DQS=0 (best) or -DSQLITE_DQS=1 (second choice) if possible.
3206 */
3207 #if !defined(SQLITE_DQS)
3208 # define SQLITE_DQS 3
3209 #endif
3210 #if (SQLITE_DQS&1)==1
3211                  | SQLITE_DqsDML
3212 #endif
3213 #if (SQLITE_DQS&2)==2
3214                  | SQLITE_DqsDDL
3215 #endif
3216 
3217 #if !defined(SQLITE_DEFAULT_AUTOMATIC_INDEX) || SQLITE_DEFAULT_AUTOMATIC_INDEX
3218                  | SQLITE_AutoIndex
3219 #endif
3220 #if SQLITE_DEFAULT_CKPTFULLFSYNC
3221                  | SQLITE_CkptFullFSync
3222 #endif
3223 #if SQLITE_DEFAULT_FILE_FORMAT<4
3224                  | SQLITE_LegacyFileFmt
3225 #endif
3226 #ifdef SQLITE_ENABLE_LOAD_EXTENSION
3227                  | SQLITE_LoadExtension
3228 #endif
3229 #if SQLITE_DEFAULT_RECURSIVE_TRIGGERS
3230                  | SQLITE_RecTriggers
3231 #endif
3232 #if defined(SQLITE_DEFAULT_FOREIGN_KEYS) && SQLITE_DEFAULT_FOREIGN_KEYS
3233                  | SQLITE_ForeignKeys
3234 #endif
3235 #if defined(SQLITE_REVERSE_UNORDERED_SELECTS)
3236                  | SQLITE_ReverseOrder
3237 #endif
3238 #if defined(SQLITE_ENABLE_OVERSIZE_CELL_CHECK)
3239                  | SQLITE_CellSizeCk
3240 #endif
3241 #if defined(SQLITE_ENABLE_FTS3_TOKENIZER)
3242                  | SQLITE_Fts3Tokenizer
3243 #endif
3244 #if defined(SQLITE_ENABLE_QPSG)
3245                  | SQLITE_EnableQPSG
3246 #endif
3247 #if defined(SQLITE_DEFAULT_DEFENSIVE)
3248                  | SQLITE_Defensive
3249 #endif
3250 #if defined(SQLITE_DEFAULT_LEGACY_ALTER_TABLE)
3251                  | SQLITE_LegacyAlter
3252 #endif
3253       ;
3254   sqlite3HashInit(&db->aCollSeq);
3255 #ifndef SQLITE_OMIT_VIRTUALTABLE
3256   sqlite3HashInit(&db->aModule);
3257 #endif
3258 
3259   /* Add the default collation sequence BINARY. BINARY works for both UTF-8
3260   ** and UTF-16, so add a version for each to avoid any unnecessary
3261   ** conversions. The only error that can occur here is a malloc() failure.
3262   **
3263   ** EVIDENCE-OF: R-52786-44878 SQLite defines three built-in collating
3264   ** functions:
3265   */
3266   createCollation(db, sqlite3StrBINARY, SQLITE_UTF8, 0, binCollFunc, 0);
3267   createCollation(db, sqlite3StrBINARY, SQLITE_UTF16BE, 0, binCollFunc, 0);
3268   createCollation(db, sqlite3StrBINARY, SQLITE_UTF16LE, 0, binCollFunc, 0);
3269   createCollation(db, "NOCASE", SQLITE_UTF8, 0, nocaseCollatingFunc, 0);
3270   createCollation(db, "RTRIM", SQLITE_UTF8, 0, rtrimCollFunc, 0);
3271   if( db->mallocFailed ){
3272     goto opendb_out;
3273   }
3274 
3275   /* Parse the filename/URI argument
3276   **
3277   ** Only allow sensible combinations of bits in the flags argument.
3278   ** Throw an error if any non-sense combination is used.  If we
3279   ** do not block illegal combinations here, it could trigger
3280   ** assert() statements in deeper layers.  Sensible combinations
3281   ** are:
3282   **
3283   **  1:  SQLITE_OPEN_READONLY
3284   **  2:  SQLITE_OPEN_READWRITE
3285   **  6:  SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE
3286   */
3287   db->openFlags = flags;
3288   assert( SQLITE_OPEN_READONLY  == 0x01 );
3289   assert( SQLITE_OPEN_READWRITE == 0x02 );
3290   assert( SQLITE_OPEN_CREATE    == 0x04 );
3291   testcase( (1<<(flags&7))==0x02 ); /* READONLY */
3292   testcase( (1<<(flags&7))==0x04 ); /* READWRITE */
3293   testcase( (1<<(flags&7))==0x40 ); /* READWRITE | CREATE */
3294   if( ((1<<(flags&7)) & 0x46)==0 ){
3295     rc = SQLITE_MISUSE_BKPT;  /* IMP: R-18321-05872 */
3296   }else{
3297     rc = sqlite3ParseUri(zVfs, zFilename, &flags, &db->pVfs, &zOpen, &zErrMsg);
3298   }
3299   if( rc!=SQLITE_OK ){
3300     if( rc==SQLITE_NOMEM ) sqlite3OomFault(db);
3301     sqlite3ErrorWithMsg(db, rc, zErrMsg ? "%s" : 0, zErrMsg);
3302     sqlite3_free(zErrMsg);
3303     goto opendb_out;
3304   }
3305 
3306   /* Open the backend database driver */
3307   rc = sqlite3BtreeOpen(db->pVfs, zOpen, db, &db->aDb[0].pBt, 0,
3308                         flags | SQLITE_OPEN_MAIN_DB);
3309   if( rc!=SQLITE_OK ){
3310     if( rc==SQLITE_IOERR_NOMEM ){
3311       rc = SQLITE_NOMEM_BKPT;
3312     }
3313     sqlite3Error(db, rc);
3314     goto opendb_out;
3315   }
3316   sqlite3BtreeEnter(db->aDb[0].pBt);
3317   db->aDb[0].pSchema = sqlite3SchemaGet(db, db->aDb[0].pBt);
3318   if( !db->mallocFailed ){
3319     sqlite3SetTextEncoding(db, SCHEMA_ENC(db));
3320   }
3321   sqlite3BtreeLeave(db->aDb[0].pBt);
3322   db->aDb[1].pSchema = sqlite3SchemaGet(db, 0);
3323 
3324   /* The default safety_level for the main database is FULL; for the temp
3325   ** database it is OFF. This matches the pager layer defaults.
3326   */
3327   db->aDb[0].zDbSName = "main";
3328   db->aDb[0].safety_level = SQLITE_DEFAULT_SYNCHRONOUS+1;
3329   db->aDb[1].zDbSName = "temp";
3330   db->aDb[1].safety_level = PAGER_SYNCHRONOUS_OFF;
3331 
3332   db->magic = SQLITE_MAGIC_OPEN;
3333   if( db->mallocFailed ){
3334     goto opendb_out;
3335   }
3336 
3337   /* Register all built-in functions, but do not attempt to read the
3338   ** database schema yet. This is delayed until the first time the database
3339   ** is accessed.
3340   */
3341   sqlite3Error(db, SQLITE_OK);
3342   sqlite3RegisterPerConnectionBuiltinFunctions(db);
3343   rc = sqlite3_errcode(db);
3344 
3345 
3346   /* Load compiled-in extensions */
3347   for(i=0; rc==SQLITE_OK && i<ArraySize(sqlite3BuiltinExtensions); i++){
3348     rc = sqlite3BuiltinExtensions[i](db);
3349   }
3350 
3351   /* Load automatic extensions - extensions that have been registered
3352   ** using the sqlite3_automatic_extension() API.
3353   */
3354   if( rc==SQLITE_OK ){
3355     sqlite3AutoLoadExtensions(db);
3356     rc = sqlite3_errcode(db);
3357     if( rc!=SQLITE_OK ){
3358       goto opendb_out;
3359     }
3360   }
3361 
3362 #ifdef SQLITE_ENABLE_INTERNAL_FUNCTIONS
3363   /* Testing use only!!! The -DSQLITE_ENABLE_INTERNAL_FUNCTIONS=1 compile-time
3364   ** option gives access to internal functions by default.
3365   ** Testing use only!!! */
3366   db->mDbFlags |= DBFLAG_InternalFunc;
3367 #endif
3368 
3369   /* -DSQLITE_DEFAULT_LOCKING_MODE=1 makes EXCLUSIVE the default locking
3370   ** mode.  -DSQLITE_DEFAULT_LOCKING_MODE=0 make NORMAL the default locking
3371   ** mode.  Doing nothing at all also makes NORMAL the default.
3372   */
3373 #ifdef SQLITE_DEFAULT_LOCKING_MODE
3374   db->dfltLockMode = SQLITE_DEFAULT_LOCKING_MODE;
3375   sqlite3PagerLockingMode(sqlite3BtreePager(db->aDb[0].pBt),
3376                           SQLITE_DEFAULT_LOCKING_MODE);
3377 #endif
3378 
3379   if( rc ) sqlite3Error(db, rc);
3380 
3381   /* Enable the lookaside-malloc subsystem */
3382   setupLookaside(db, 0, sqlite3GlobalConfig.szLookaside,
3383                         sqlite3GlobalConfig.nLookaside);
3384 
3385   sqlite3_wal_autocheckpoint(db, SQLITE_DEFAULT_WAL_AUTOCHECKPOINT);
3386 
3387 opendb_out:
3388   if( db ){
3389     assert( db->mutex!=0 || isThreadsafe==0
3390            || sqlite3GlobalConfig.bFullMutex==0 );
3391     sqlite3_mutex_leave(db->mutex);
3392   }
3393   rc = sqlite3_errcode(db);
3394   assert( db!=0 || rc==SQLITE_NOMEM );
3395   if( rc==SQLITE_NOMEM ){
3396     sqlite3_close(db);
3397     db = 0;
3398   }else if( rc!=SQLITE_OK ){
3399     db->magic = SQLITE_MAGIC_SICK;
3400   }
3401   *ppDb = db;
3402 #ifdef SQLITE_ENABLE_SQLLOG
3403   if( sqlite3GlobalConfig.xSqllog ){
3404     /* Opening a db handle. Fourth parameter is passed 0. */
3405     void *pArg = sqlite3GlobalConfig.pSqllogArg;
3406     sqlite3GlobalConfig.xSqllog(pArg, db, zFilename, 0);
3407   }
3408 #endif
3409   sqlite3_free_filename(zOpen);
3410   return rc & 0xff;
3411 }
3412 
3413 
3414 /*
3415 ** Open a new database handle.
3416 */
3417 int sqlite3_open(
3418   const char *zFilename,
3419   sqlite3 **ppDb
3420 ){
3421   return openDatabase(zFilename, ppDb,
3422                       SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
3423 }
3424 int sqlite3_open_v2(
3425   const char *filename,   /* Database filename (UTF-8) */
3426   sqlite3 **ppDb,         /* OUT: SQLite db handle */
3427   int flags,              /* Flags */
3428   const char *zVfs        /* Name of VFS module to use */
3429 ){
3430   return openDatabase(filename, ppDb, (unsigned int)flags, zVfs);
3431 }
3432 
3433 #ifndef SQLITE_OMIT_UTF16
3434 /*
3435 ** Open a new database handle.
3436 */
3437 int sqlite3_open16(
3438   const void *zFilename,
3439   sqlite3 **ppDb
3440 ){
3441   char const *zFilename8;   /* zFilename encoded in UTF-8 instead of UTF-16 */
3442   sqlite3_value *pVal;
3443   int rc;
3444 
3445 #ifdef SQLITE_ENABLE_API_ARMOR
3446   if( ppDb==0 ) return SQLITE_MISUSE_BKPT;
3447 #endif
3448   *ppDb = 0;
3449 #ifndef SQLITE_OMIT_AUTOINIT
3450   rc = sqlite3_initialize();
3451   if( rc ) return rc;
3452 #endif
3453   if( zFilename==0 ) zFilename = "\000\000";
3454   pVal = sqlite3ValueNew(0);
3455   sqlite3ValueSetStr(pVal, -1, zFilename, SQLITE_UTF16NATIVE, SQLITE_STATIC);
3456   zFilename8 = sqlite3ValueText(pVal, SQLITE_UTF8);
3457   if( zFilename8 ){
3458     rc = openDatabase(zFilename8, ppDb,
3459                       SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
3460     assert( *ppDb || rc==SQLITE_NOMEM );
3461     if( rc==SQLITE_OK && !DbHasProperty(*ppDb, 0, DB_SchemaLoaded) ){
3462       SCHEMA_ENC(*ppDb) = ENC(*ppDb) = SQLITE_UTF16NATIVE;
3463     }
3464   }else{
3465     rc = SQLITE_NOMEM_BKPT;
3466   }
3467   sqlite3ValueFree(pVal);
3468 
3469   return rc & 0xff;
3470 }
3471 #endif /* SQLITE_OMIT_UTF16 */
3472 
3473 /*
3474 ** Register a new collation sequence with the database handle db.
3475 */
3476 int sqlite3_create_collation(
3477   sqlite3* db,
3478   const char *zName,
3479   int enc,
3480   void* pCtx,
3481   int(*xCompare)(void*,int,const void*,int,const void*)
3482 ){
3483   return sqlite3_create_collation_v2(db, zName, enc, pCtx, xCompare, 0);
3484 }
3485 
3486 /*
3487 ** Register a new collation sequence with the database handle db.
3488 */
3489 int sqlite3_create_collation_v2(
3490   sqlite3* db,
3491   const char *zName,
3492   int enc,
3493   void* pCtx,
3494   int(*xCompare)(void*,int,const void*,int,const void*),
3495   void(*xDel)(void*)
3496 ){
3497   int rc;
3498 
3499 #ifdef SQLITE_ENABLE_API_ARMOR
3500   if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
3501 #endif
3502   sqlite3_mutex_enter(db->mutex);
3503   assert( !db->mallocFailed );
3504   rc = createCollation(db, zName, (u8)enc, pCtx, xCompare, xDel);
3505   rc = sqlite3ApiExit(db, rc);
3506   sqlite3_mutex_leave(db->mutex);
3507   return rc;
3508 }
3509 
3510 #ifndef SQLITE_OMIT_UTF16
3511 /*
3512 ** Register a new collation sequence with the database handle db.
3513 */
3514 int sqlite3_create_collation16(
3515   sqlite3* db,
3516   const void *zName,
3517   int enc,
3518   void* pCtx,
3519   int(*xCompare)(void*,int,const void*,int,const void*)
3520 ){
3521   int rc = SQLITE_OK;
3522   char *zName8;
3523 
3524 #ifdef SQLITE_ENABLE_API_ARMOR
3525   if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
3526 #endif
3527   sqlite3_mutex_enter(db->mutex);
3528   assert( !db->mallocFailed );
3529   zName8 = sqlite3Utf16to8(db, zName, -1, SQLITE_UTF16NATIVE);
3530   if( zName8 ){
3531     rc = createCollation(db, zName8, (u8)enc, pCtx, xCompare, 0);
3532     sqlite3DbFree(db, zName8);
3533   }
3534   rc = sqlite3ApiExit(db, rc);
3535   sqlite3_mutex_leave(db->mutex);
3536   return rc;
3537 }
3538 #endif /* SQLITE_OMIT_UTF16 */
3539 
3540 /*
3541 ** Register a collation sequence factory callback with the database handle
3542 ** db. Replace any previously installed collation sequence factory.
3543 */
3544 int sqlite3_collation_needed(
3545   sqlite3 *db,
3546   void *pCollNeededArg,
3547   void(*xCollNeeded)(void*,sqlite3*,int eTextRep,const char*)
3548 ){
3549 #ifdef SQLITE_ENABLE_API_ARMOR
3550   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3551 #endif
3552   sqlite3_mutex_enter(db->mutex);
3553   db->xCollNeeded = xCollNeeded;
3554   db->xCollNeeded16 = 0;
3555   db->pCollNeededArg = pCollNeededArg;
3556   sqlite3_mutex_leave(db->mutex);
3557   return SQLITE_OK;
3558 }
3559 
3560 #ifndef SQLITE_OMIT_UTF16
3561 /*
3562 ** Register a collation sequence factory callback with the database handle
3563 ** db. Replace any previously installed collation sequence factory.
3564 */
3565 int sqlite3_collation_needed16(
3566   sqlite3 *db,
3567   void *pCollNeededArg,
3568   void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*)
3569 ){
3570 #ifdef SQLITE_ENABLE_API_ARMOR
3571   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3572 #endif
3573   sqlite3_mutex_enter(db->mutex);
3574   db->xCollNeeded = 0;
3575   db->xCollNeeded16 = xCollNeeded16;
3576   db->pCollNeededArg = pCollNeededArg;
3577   sqlite3_mutex_leave(db->mutex);
3578   return SQLITE_OK;
3579 }
3580 #endif /* SQLITE_OMIT_UTF16 */
3581 
3582 #ifndef SQLITE_OMIT_DEPRECATED
3583 /*
3584 ** This function is now an anachronism. It used to be used to recover from a
3585 ** malloc() failure, but SQLite now does this automatically.
3586 */
3587 int sqlite3_global_recover(void){
3588   return SQLITE_OK;
3589 }
3590 #endif
3591 
3592 /*
3593 ** Test to see whether or not the database connection is in autocommit
3594 ** mode.  Return TRUE if it is and FALSE if not.  Autocommit mode is on
3595 ** by default.  Autocommit is disabled by a BEGIN statement and reenabled
3596 ** by the next COMMIT or ROLLBACK.
3597 */
3598 int sqlite3_get_autocommit(sqlite3 *db){
3599 #ifdef SQLITE_ENABLE_API_ARMOR
3600   if( !sqlite3SafetyCheckOk(db) ){
3601     (void)SQLITE_MISUSE_BKPT;
3602     return 0;
3603   }
3604 #endif
3605   return db->autoCommit;
3606 }
3607 
3608 /*
3609 ** The following routines are substitutes for constants SQLITE_CORRUPT,
3610 ** SQLITE_MISUSE, SQLITE_CANTOPEN, SQLITE_NOMEM and possibly other error
3611 ** constants.  They serve two purposes:
3612 **
3613 **   1.  Serve as a convenient place to set a breakpoint in a debugger
3614 **       to detect when version error conditions occurs.
3615 **
3616 **   2.  Invoke sqlite3_log() to provide the source code location where
3617 **       a low-level error is first detected.
3618 */
3619 int sqlite3ReportError(int iErr, int lineno, const char *zType){
3620   sqlite3_log(iErr, "%s at line %d of [%.10s]",
3621               zType, lineno, 20+sqlite3_sourceid());
3622   return iErr;
3623 }
3624 int sqlite3CorruptError(int lineno){
3625   testcase( sqlite3GlobalConfig.xLog!=0 );
3626   return sqlite3ReportError(SQLITE_CORRUPT, lineno, "database corruption");
3627 }
3628 int sqlite3MisuseError(int lineno){
3629   testcase( sqlite3GlobalConfig.xLog!=0 );
3630   return sqlite3ReportError(SQLITE_MISUSE, lineno, "misuse");
3631 }
3632 int sqlite3CantopenError(int lineno){
3633   testcase( sqlite3GlobalConfig.xLog!=0 );
3634   return sqlite3ReportError(SQLITE_CANTOPEN, lineno, "cannot open file");
3635 }
3636 #if defined(SQLITE_DEBUG) || defined(SQLITE_ENABLE_CORRUPT_PGNO)
3637 int sqlite3CorruptPgnoError(int lineno, Pgno pgno){
3638   char zMsg[100];
3639   sqlite3_snprintf(sizeof(zMsg), zMsg, "database corruption page %d", pgno);
3640   testcase( sqlite3GlobalConfig.xLog!=0 );
3641   return sqlite3ReportError(SQLITE_CORRUPT, lineno, zMsg);
3642 }
3643 #endif
3644 #ifdef SQLITE_DEBUG
3645 int sqlite3NomemError(int lineno){
3646   testcase( sqlite3GlobalConfig.xLog!=0 );
3647   return sqlite3ReportError(SQLITE_NOMEM, lineno, "OOM");
3648 }
3649 int sqlite3IoerrnomemError(int lineno){
3650   testcase( sqlite3GlobalConfig.xLog!=0 );
3651   return sqlite3ReportError(SQLITE_IOERR_NOMEM, lineno, "I/O OOM error");
3652 }
3653 #endif
3654 
3655 #ifndef SQLITE_OMIT_DEPRECATED
3656 /*
3657 ** This is a convenience routine that makes sure that all thread-specific
3658 ** data for this thread has been deallocated.
3659 **
3660 ** SQLite no longer uses thread-specific data so this routine is now a
3661 ** no-op.  It is retained for historical compatibility.
3662 */
3663 void sqlite3_thread_cleanup(void){
3664 }
3665 #endif
3666 
3667 /*
3668 ** Return meta information about a specific column of a database table.
3669 ** See comment in sqlite3.h (sqlite.h.in) for details.
3670 */
3671 int sqlite3_table_column_metadata(
3672   sqlite3 *db,                /* Connection handle */
3673   const char *zDbName,        /* Database name or NULL */
3674   const char *zTableName,     /* Table name */
3675   const char *zColumnName,    /* Column name */
3676   char const **pzDataType,    /* OUTPUT: Declared data type */
3677   char const **pzCollSeq,     /* OUTPUT: Collation sequence name */
3678   int *pNotNull,              /* OUTPUT: True if NOT NULL constraint exists */
3679   int *pPrimaryKey,           /* OUTPUT: True if column part of PK */
3680   int *pAutoinc               /* OUTPUT: True if column is auto-increment */
3681 ){
3682   int rc;
3683   char *zErrMsg = 0;
3684   Table *pTab = 0;
3685   Column *pCol = 0;
3686   int iCol = 0;
3687   char const *zDataType = 0;
3688   char const *zCollSeq = 0;
3689   int notnull = 0;
3690   int primarykey = 0;
3691   int autoinc = 0;
3692 
3693 
3694 #ifdef SQLITE_ENABLE_API_ARMOR
3695   if( !sqlite3SafetyCheckOk(db) || zTableName==0 ){
3696     return SQLITE_MISUSE_BKPT;
3697   }
3698 #endif
3699 
3700   /* Ensure the database schema has been loaded */
3701   sqlite3_mutex_enter(db->mutex);
3702   sqlite3BtreeEnterAll(db);
3703   rc = sqlite3Init(db, &zErrMsg);
3704   if( SQLITE_OK!=rc ){
3705     goto error_out;
3706   }
3707 
3708   /* Locate the table in question */
3709   pTab = sqlite3FindTable(db, zTableName, zDbName);
3710   if( !pTab || pTab->pSelect ){
3711     pTab = 0;
3712     goto error_out;
3713   }
3714 
3715   /* Find the column for which info is requested */
3716   if( zColumnName==0 ){
3717     /* Query for existance of table only */
3718   }else{
3719     for(iCol=0; iCol<pTab->nCol; iCol++){
3720       pCol = &pTab->aCol[iCol];
3721       if( 0==sqlite3StrICmp(pCol->zName, zColumnName) ){
3722         break;
3723       }
3724     }
3725     if( iCol==pTab->nCol ){
3726       if( HasRowid(pTab) && sqlite3IsRowid(zColumnName) ){
3727         iCol = pTab->iPKey;
3728         pCol = iCol>=0 ? &pTab->aCol[iCol] : 0;
3729       }else{
3730         pTab = 0;
3731         goto error_out;
3732       }
3733     }
3734   }
3735 
3736   /* The following block stores the meta information that will be returned
3737   ** to the caller in local variables zDataType, zCollSeq, notnull, primarykey
3738   ** and autoinc. At this point there are two possibilities:
3739   **
3740   **     1. The specified column name was rowid", "oid" or "_rowid_"
3741   **        and there is no explicitly declared IPK column.
3742   **
3743   **     2. The table is not a view and the column name identified an
3744   **        explicitly declared column. Copy meta information from *pCol.
3745   */
3746   if( pCol ){
3747     zDataType = sqlite3ColumnType(pCol,0);
3748     zCollSeq = pCol->zColl;
3749     notnull = pCol->notNull!=0;
3750     primarykey  = (pCol->colFlags & COLFLAG_PRIMKEY)!=0;
3751     autoinc = pTab->iPKey==iCol && (pTab->tabFlags & TF_Autoincrement)!=0;
3752   }else{
3753     zDataType = "INTEGER";
3754     primarykey = 1;
3755   }
3756   if( !zCollSeq ){
3757     zCollSeq = sqlite3StrBINARY;
3758   }
3759 
3760 error_out:
3761   sqlite3BtreeLeaveAll(db);
3762 
3763   /* Whether the function call succeeded or failed, set the output parameters
3764   ** to whatever their local counterparts contain. If an error did occur,
3765   ** this has the effect of zeroing all output parameters.
3766   */
3767   if( pzDataType ) *pzDataType = zDataType;
3768   if( pzCollSeq ) *pzCollSeq = zCollSeq;
3769   if( pNotNull ) *pNotNull = notnull;
3770   if( pPrimaryKey ) *pPrimaryKey = primarykey;
3771   if( pAutoinc ) *pAutoinc = autoinc;
3772 
3773   if( SQLITE_OK==rc && !pTab ){
3774     sqlite3DbFree(db, zErrMsg);
3775     zErrMsg = sqlite3MPrintf(db, "no such table column: %s.%s", zTableName,
3776         zColumnName);
3777     rc = SQLITE_ERROR;
3778   }
3779   sqlite3ErrorWithMsg(db, rc, (zErrMsg?"%s":0), zErrMsg);
3780   sqlite3DbFree(db, zErrMsg);
3781   rc = sqlite3ApiExit(db, rc);
3782   sqlite3_mutex_leave(db->mutex);
3783   return rc;
3784 }
3785 
3786 /*
3787 ** Sleep for a little while.  Return the amount of time slept.
3788 */
3789 int sqlite3_sleep(int ms){
3790   sqlite3_vfs *pVfs;
3791   int rc;
3792   pVfs = sqlite3_vfs_find(0);
3793   if( pVfs==0 ) return 0;
3794 
3795   /* This function works in milliseconds, but the underlying OsSleep()
3796   ** API uses microseconds. Hence the 1000's.
3797   */
3798   rc = (sqlite3OsSleep(pVfs, 1000*ms)/1000);
3799   return rc;
3800 }
3801 
3802 /*
3803 ** Enable or disable the extended result codes.
3804 */
3805 int sqlite3_extended_result_codes(sqlite3 *db, int onoff){
3806 #ifdef SQLITE_ENABLE_API_ARMOR
3807   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3808 #endif
3809   sqlite3_mutex_enter(db->mutex);
3810   db->errMask = onoff ? 0xffffffff : 0xff;
3811   sqlite3_mutex_leave(db->mutex);
3812   return SQLITE_OK;
3813 }
3814 
3815 /*
3816 ** Invoke the xFileControl method on a particular database.
3817 */
3818 int sqlite3_file_control(sqlite3 *db, const char *zDbName, int op, void *pArg){
3819   int rc = SQLITE_ERROR;
3820   Btree *pBtree;
3821 
3822 #ifdef SQLITE_ENABLE_API_ARMOR
3823   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
3824 #endif
3825   sqlite3_mutex_enter(db->mutex);
3826   pBtree = sqlite3DbNameToBtree(db, zDbName);
3827   if( pBtree ){
3828     Pager *pPager;
3829     sqlite3_file *fd;
3830     sqlite3BtreeEnter(pBtree);
3831     pPager = sqlite3BtreePager(pBtree);
3832     assert( pPager!=0 );
3833     fd = sqlite3PagerFile(pPager);
3834     assert( fd!=0 );
3835     if( op==SQLITE_FCNTL_FILE_POINTER ){
3836       *(sqlite3_file**)pArg = fd;
3837       rc = SQLITE_OK;
3838     }else if( op==SQLITE_FCNTL_VFS_POINTER ){
3839       *(sqlite3_vfs**)pArg = sqlite3PagerVfs(pPager);
3840       rc = SQLITE_OK;
3841     }else if( op==SQLITE_FCNTL_JOURNAL_POINTER ){
3842       *(sqlite3_file**)pArg = sqlite3PagerJrnlFile(pPager);
3843       rc = SQLITE_OK;
3844     }else if( op==SQLITE_FCNTL_DATA_VERSION ){
3845       *(unsigned int*)pArg = sqlite3PagerDataVersion(pPager);
3846       rc = SQLITE_OK;
3847     }else if( op==SQLITE_FCNTL_RESERVE_BYTES ){
3848       int iNew = *(int*)pArg;
3849       *(int*)pArg = sqlite3BtreeGetRequestedReserve(pBtree);
3850       if( iNew>=0 && iNew<=255 ){
3851         sqlite3BtreeSetPageSize(pBtree, 0, iNew, 0);
3852       }
3853       rc = SQLITE_OK;
3854     }else{
3855       int nSave = db->busyHandler.nBusy;
3856       rc = sqlite3OsFileControl(fd, op, pArg);
3857       db->busyHandler.nBusy = nSave;
3858     }
3859     sqlite3BtreeLeave(pBtree);
3860   }
3861   sqlite3_mutex_leave(db->mutex);
3862   return rc;
3863 }
3864 
3865 /*
3866 ** Interface to the testing logic.
3867 */
3868 int sqlite3_test_control(int op, ...){
3869   int rc = 0;
3870 #ifdef SQLITE_UNTESTABLE
3871   UNUSED_PARAMETER(op);
3872 #else
3873   va_list ap;
3874   va_start(ap, op);
3875   switch( op ){
3876 
3877     /*
3878     ** Save the current state of the PRNG.
3879     */
3880     case SQLITE_TESTCTRL_PRNG_SAVE: {
3881       sqlite3PrngSaveState();
3882       break;
3883     }
3884 
3885     /*
3886     ** Restore the state of the PRNG to the last state saved using
3887     ** PRNG_SAVE.  If PRNG_SAVE has never before been called, then
3888     ** this verb acts like PRNG_RESET.
3889     */
3890     case SQLITE_TESTCTRL_PRNG_RESTORE: {
3891       sqlite3PrngRestoreState();
3892       break;
3893     }
3894 
3895     /*  sqlite3_test_control(SQLITE_TESTCTRL_PRNG_SEED, int x, sqlite3 *db);
3896     **
3897     ** Control the seed for the pseudo-random number generator (PRNG) that
3898     ** is built into SQLite.  Cases:
3899     **
3900     **    x!=0 && db!=0       Seed the PRNG to the current value of the
3901     **                        schema cookie in the main database for db, or
3902     **                        x if the schema cookie is zero.  This case
3903     **                        is convenient to use with database fuzzers
3904     **                        as it allows the fuzzer some control over the
3905     **                        the PRNG seed.
3906     **
3907     **    x!=0 && db==0       Seed the PRNG to the value of x.
3908     **
3909     **    x==0 && db==0       Revert to default behavior of using the
3910     **                        xRandomness method on the primary VFS.
3911     **
3912     ** This test-control also resets the PRNG so that the new seed will
3913     ** be used for the next call to sqlite3_randomness().
3914     */
3915 #ifndef SQLITE_OMIT_WSD
3916     case SQLITE_TESTCTRL_PRNG_SEED: {
3917       int x = va_arg(ap, int);
3918       int y;
3919       sqlite3 *db = va_arg(ap, sqlite3*);
3920       assert( db==0 || db->aDb[0].pSchema!=0 );
3921       if( db && (y = db->aDb[0].pSchema->schema_cookie)!=0 ){ x = y; }
3922       sqlite3Config.iPrngSeed = x;
3923       sqlite3_randomness(0,0);
3924       break;
3925     }
3926 #endif
3927 
3928     /*
3929     **  sqlite3_test_control(BITVEC_TEST, size, program)
3930     **
3931     ** Run a test against a Bitvec object of size.  The program argument
3932     ** is an array of integers that defines the test.  Return -1 on a
3933     ** memory allocation error, 0 on success, or non-zero for an error.
3934     ** See the sqlite3BitvecBuiltinTest() for additional information.
3935     */
3936     case SQLITE_TESTCTRL_BITVEC_TEST: {
3937       int sz = va_arg(ap, int);
3938       int *aProg = va_arg(ap, int*);
3939       rc = sqlite3BitvecBuiltinTest(sz, aProg);
3940       break;
3941     }
3942 
3943     /*
3944     **  sqlite3_test_control(FAULT_INSTALL, xCallback)
3945     **
3946     ** Arrange to invoke xCallback() whenever sqlite3FaultSim() is called,
3947     ** if xCallback is not NULL.
3948     **
3949     ** As a test of the fault simulator mechanism itself, sqlite3FaultSim(0)
3950     ** is called immediately after installing the new callback and the return
3951     ** value from sqlite3FaultSim(0) becomes the return from
3952     ** sqlite3_test_control().
3953     */
3954     case SQLITE_TESTCTRL_FAULT_INSTALL: {
3955       /* MSVC is picky about pulling func ptrs from va lists.
3956       ** http://support.microsoft.com/kb/47961
3957       ** sqlite3GlobalConfig.xTestCallback = va_arg(ap, int(*)(int));
3958       */
3959       typedef int(*TESTCALLBACKFUNC_t)(int);
3960       sqlite3GlobalConfig.xTestCallback = va_arg(ap, TESTCALLBACKFUNC_t);
3961       rc = sqlite3FaultSim(0);
3962       break;
3963     }
3964 
3965     /*
3966     **  sqlite3_test_control(BENIGN_MALLOC_HOOKS, xBegin, xEnd)
3967     **
3968     ** Register hooks to call to indicate which malloc() failures
3969     ** are benign.
3970     */
3971     case SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS: {
3972       typedef void (*void_function)(void);
3973       void_function xBenignBegin;
3974       void_function xBenignEnd;
3975       xBenignBegin = va_arg(ap, void_function);
3976       xBenignEnd = va_arg(ap, void_function);
3977       sqlite3BenignMallocHooks(xBenignBegin, xBenignEnd);
3978       break;
3979     }
3980 
3981     /*
3982     **  sqlite3_test_control(SQLITE_TESTCTRL_PENDING_BYTE, unsigned int X)
3983     **
3984     ** Set the PENDING byte to the value in the argument, if X>0.
3985     ** Make no changes if X==0.  Return the value of the pending byte
3986     ** as it existing before this routine was called.
3987     **
3988     ** IMPORTANT:  Changing the PENDING byte from 0x40000000 results in
3989     ** an incompatible database file format.  Changing the PENDING byte
3990     ** while any database connection is open results in undefined and
3991     ** deleterious behavior.
3992     */
3993     case SQLITE_TESTCTRL_PENDING_BYTE: {
3994       rc = PENDING_BYTE;
3995 #ifndef SQLITE_OMIT_WSD
3996       {
3997         unsigned int newVal = va_arg(ap, unsigned int);
3998         if( newVal ) sqlite3PendingByte = newVal;
3999       }
4000 #endif
4001       break;
4002     }
4003 
4004     /*
4005     **  sqlite3_test_control(SQLITE_TESTCTRL_ASSERT, int X)
4006     **
4007     ** This action provides a run-time test to see whether or not
4008     ** assert() was enabled at compile-time.  If X is true and assert()
4009     ** is enabled, then the return value is true.  If X is true and
4010     ** assert() is disabled, then the return value is zero.  If X is
4011     ** false and assert() is enabled, then the assertion fires and the
4012     ** process aborts.  If X is false and assert() is disabled, then the
4013     ** return value is zero.
4014     */
4015     case SQLITE_TESTCTRL_ASSERT: {
4016       volatile int x = 0;
4017       assert( /*side-effects-ok*/ (x = va_arg(ap,int))!=0 );
4018       rc = x;
4019       break;
4020     }
4021 
4022 
4023     /*
4024     **  sqlite3_test_control(SQLITE_TESTCTRL_ALWAYS, int X)
4025     **
4026     ** This action provides a run-time test to see how the ALWAYS and
4027     ** NEVER macros were defined at compile-time.
4028     **
4029     ** The return value is ALWAYS(X) if X is true, or 0 if X is false.
4030     **
4031     ** The recommended test is X==2.  If the return value is 2, that means
4032     ** ALWAYS() and NEVER() are both no-op pass-through macros, which is the
4033     ** default setting.  If the return value is 1, then ALWAYS() is either
4034     ** hard-coded to true or else it asserts if its argument is false.
4035     ** The first behavior (hard-coded to true) is the case if
4036     ** SQLITE_TESTCTRL_ASSERT shows that assert() is disabled and the second
4037     ** behavior (assert if the argument to ALWAYS() is false) is the case if
4038     ** SQLITE_TESTCTRL_ASSERT shows that assert() is enabled.
4039     **
4040     ** The run-time test procedure might look something like this:
4041     **
4042     **    if( sqlite3_test_control(SQLITE_TESTCTRL_ALWAYS, 2)==2 ){
4043     **      // ALWAYS() and NEVER() are no-op pass-through macros
4044     **    }else if( sqlite3_test_control(SQLITE_TESTCTRL_ASSERT, 1) ){
4045     **      // ALWAYS(x) asserts that x is true. NEVER(x) asserts x is false.
4046     **    }else{
4047     **      // ALWAYS(x) is a constant 1.  NEVER(x) is a constant 0.
4048     **    }
4049     */
4050     case SQLITE_TESTCTRL_ALWAYS: {
4051       int x = va_arg(ap,int);
4052       rc = x ? ALWAYS(x) : 0;
4053       break;
4054     }
4055 
4056     /*
4057     **   sqlite3_test_control(SQLITE_TESTCTRL_BYTEORDER);
4058     **
4059     ** The integer returned reveals the byte-order of the computer on which
4060     ** SQLite is running:
4061     **
4062     **       1     big-endian,    determined at run-time
4063     **      10     little-endian, determined at run-time
4064     **  432101     big-endian,    determined at compile-time
4065     **  123410     little-endian, determined at compile-time
4066     */
4067     case SQLITE_TESTCTRL_BYTEORDER: {
4068       rc = SQLITE_BYTEORDER*100 + SQLITE_LITTLEENDIAN*10 + SQLITE_BIGENDIAN;
4069       break;
4070     }
4071 
4072     /*  sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS, sqlite3 *db, int N)
4073     **
4074     ** Enable or disable various optimizations for testing purposes.  The
4075     ** argument N is a bitmask of optimizations to be disabled.  For normal
4076     ** operation N should be 0.  The idea is that a test program (like the
4077     ** SQL Logic Test or SLT test module) can run the same SQL multiple times
4078     ** with various optimizations disabled to verify that the same answer
4079     ** is obtained in every case.
4080     */
4081     case SQLITE_TESTCTRL_OPTIMIZATIONS: {
4082       sqlite3 *db = va_arg(ap, sqlite3*);
4083       db->dbOptFlags = (u16)(va_arg(ap, int) & 0xffff);
4084       break;
4085     }
4086 
4087     /*   sqlite3_test_control(SQLITE_TESTCTRL_LOCALTIME_FAULT, int onoff);
4088     **
4089     ** If parameter onoff is non-zero, subsequent calls to localtime()
4090     ** and its variants fail. If onoff is zero, undo this setting.
4091     */
4092     case SQLITE_TESTCTRL_LOCALTIME_FAULT: {
4093       sqlite3GlobalConfig.bLocaltimeFault = va_arg(ap, int);
4094       break;
4095     }
4096 
4097     /*   sqlite3_test_control(SQLITE_TESTCTRL_INTERNAL_FUNCTIONS, sqlite3*);
4098     **
4099     ** Toggle the ability to use internal functions on or off for
4100     ** the database connection given in the argument.
4101     */
4102     case SQLITE_TESTCTRL_INTERNAL_FUNCTIONS: {
4103       sqlite3 *db = va_arg(ap, sqlite3*);
4104       db->mDbFlags ^= DBFLAG_InternalFunc;
4105       break;
4106     }
4107 
4108     /*   sqlite3_test_control(SQLITE_TESTCTRL_NEVER_CORRUPT, int);
4109     **
4110     ** Set or clear a flag that indicates that the database file is always well-
4111     ** formed and never corrupt.  This flag is clear by default, indicating that
4112     ** database files might have arbitrary corruption.  Setting the flag during
4113     ** testing causes certain assert() statements in the code to be activated
4114     ** that demonstrat invariants on well-formed database files.
4115     */
4116     case SQLITE_TESTCTRL_NEVER_CORRUPT: {
4117       sqlite3GlobalConfig.neverCorrupt = va_arg(ap, int);
4118       break;
4119     }
4120 
4121     /*   sqlite3_test_control(SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS, int);
4122     **
4123     ** Set or clear a flag that causes SQLite to verify that type, name,
4124     ** and tbl_name fields of the sqlite_schema table.  This is normally
4125     ** on, but it is sometimes useful to turn it off for testing.
4126     **
4127     ** 2020-07-22:  Disabling EXTRA_SCHEMA_CHECKS also disables the
4128     ** verification of rootpage numbers when parsing the schema.  This
4129     ** is useful to make it easier to reach strange internal error states
4130     ** during testing.  The EXTRA_SCHEMA_CHECKS setting is always enabled
4131     ** in production.
4132     */
4133     case SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS: {
4134       sqlite3GlobalConfig.bExtraSchemaChecks = va_arg(ap, int);
4135       break;
4136     }
4137 
4138     /* Set the threshold at which OP_Once counters reset back to zero.
4139     ** By default this is 0x7ffffffe (over 2 billion), but that value is
4140     ** too big to test in a reasonable amount of time, so this control is
4141     ** provided to set a small and easily reachable reset value.
4142     */
4143     case SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD: {
4144       sqlite3GlobalConfig.iOnceResetThreshold = va_arg(ap, int);
4145       break;
4146     }
4147 
4148     /*   sqlite3_test_control(SQLITE_TESTCTRL_VDBE_COVERAGE, xCallback, ptr);
4149     **
4150     ** Set the VDBE coverage callback function to xCallback with context
4151     ** pointer ptr.
4152     */
4153     case SQLITE_TESTCTRL_VDBE_COVERAGE: {
4154 #ifdef SQLITE_VDBE_COVERAGE
4155       typedef void (*branch_callback)(void*,unsigned int,
4156                                       unsigned char,unsigned char);
4157       sqlite3GlobalConfig.xVdbeBranch = va_arg(ap,branch_callback);
4158       sqlite3GlobalConfig.pVdbeBranchArg = va_arg(ap,void*);
4159 #endif
4160       break;
4161     }
4162 
4163     /*   sqlite3_test_control(SQLITE_TESTCTRL_SORTER_MMAP, db, nMax); */
4164     case SQLITE_TESTCTRL_SORTER_MMAP: {
4165       sqlite3 *db = va_arg(ap, sqlite3*);
4166       db->nMaxSorterMmap = va_arg(ap, int);
4167       break;
4168     }
4169 
4170     /*   sqlite3_test_control(SQLITE_TESTCTRL_ISINIT);
4171     **
4172     ** Return SQLITE_OK if SQLite has been initialized and SQLITE_ERROR if
4173     ** not.
4174     */
4175     case SQLITE_TESTCTRL_ISINIT: {
4176       if( sqlite3GlobalConfig.isInit==0 ) rc = SQLITE_ERROR;
4177       break;
4178     }
4179 
4180     /*  sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, db, dbName, onOff, tnum);
4181     **
4182     ** This test control is used to create imposter tables.  "db" is a pointer
4183     ** to the database connection.  dbName is the database name (ex: "main" or
4184     ** "temp") which will receive the imposter.  "onOff" turns imposter mode on
4185     ** or off.  "tnum" is the root page of the b-tree to which the imposter
4186     ** table should connect.
4187     **
4188     ** Enable imposter mode only when the schema has already been parsed.  Then
4189     ** run a single CREATE TABLE statement to construct the imposter table in
4190     ** the parsed schema.  Then turn imposter mode back off again.
4191     **
4192     ** If onOff==0 and tnum>0 then reset the schema for all databases, causing
4193     ** the schema to be reparsed the next time it is needed.  This has the
4194     ** effect of erasing all imposter tables.
4195     */
4196     case SQLITE_TESTCTRL_IMPOSTER: {
4197       sqlite3 *db = va_arg(ap, sqlite3*);
4198       sqlite3_mutex_enter(db->mutex);
4199       db->init.iDb = sqlite3FindDbName(db, va_arg(ap,const char*));
4200       db->init.busy = db->init.imposterTable = va_arg(ap,int);
4201       db->init.newTnum = va_arg(ap,int);
4202       if( db->init.busy==0 && db->init.newTnum>0 ){
4203         sqlite3ResetAllSchemasOfConnection(db);
4204       }
4205       sqlite3_mutex_leave(db->mutex);
4206       break;
4207     }
4208 
4209 #if defined(YYCOVERAGE)
4210     /*  sqlite3_test_control(SQLITE_TESTCTRL_PARSER_COVERAGE, FILE *out)
4211     **
4212     ** This test control (only available when SQLite is compiled with
4213     ** -DYYCOVERAGE) writes a report onto "out" that shows all
4214     ** state/lookahead combinations in the parser state machine
4215     ** which are never exercised.  If any state is missed, make the
4216     ** return code SQLITE_ERROR.
4217     */
4218     case SQLITE_TESTCTRL_PARSER_COVERAGE: {
4219       FILE *out = va_arg(ap, FILE*);
4220       if( sqlite3ParserCoverage(out) ) rc = SQLITE_ERROR;
4221       break;
4222     }
4223 #endif /* defined(YYCOVERAGE) */
4224 
4225     /*  sqlite3_test_control(SQLITE_TESTCTRL_RESULT_INTREAL, sqlite3_context*);
4226     **
4227     ** This test-control causes the most recent sqlite3_result_int64() value
4228     ** to be interpreted as a MEM_IntReal instead of as an MEM_Int.  Normally,
4229     ** MEM_IntReal values only arise during an INSERT operation of integer
4230     ** values into a REAL column, so they can be challenging to test.  This
4231     ** test-control enables us to write an intreal() SQL function that can
4232     ** inject an intreal() value at arbitrary places in an SQL statement,
4233     ** for testing purposes.
4234     */
4235     case SQLITE_TESTCTRL_RESULT_INTREAL: {
4236       sqlite3_context *pCtx = va_arg(ap, sqlite3_context*);
4237       sqlite3ResultIntReal(pCtx);
4238       break;
4239     }
4240 
4241     /*  sqlite3_test_control(SQLITE_TESTCTRL_SEEK_COUNT,
4242     **    sqlite3 *db,    // Database connection
4243     **    u64 *pnSeek     // Write seek count here
4244     **  );
4245     **
4246     ** This test-control queries the seek-counter on the "main" database
4247     ** file.  The seek-counter is written into *pnSeek and is then reset.
4248     ** The seek-count is only available if compiled with SQLITE_DEBUG.
4249     */
4250     case SQLITE_TESTCTRL_SEEK_COUNT: {
4251       sqlite3 *db = va_arg(ap, sqlite3*);
4252       u64 *pn = va_arg(ap, sqlite3_uint64*);
4253       *pn = sqlite3BtreeSeekCount(db->aDb->pBt);
4254       (void)db;  /* Silence harmless unused variable warning */
4255       break;
4256     }
4257 
4258 
4259   }
4260   va_end(ap);
4261 #endif /* SQLITE_UNTESTABLE */
4262   return rc;
4263 }
4264 
4265 /*
4266 ** The Pager stores the Database filename, Journal filename, and WAL filename
4267 ** consecutively in memory, in that order.  The database filename is prefixed
4268 ** by four zero bytes.  Locate the start of the database filename by searching
4269 ** backwards for the first byte following four consecutive zero bytes.
4270 **
4271 ** This only works if the filename passed in was obtained from the Pager.
4272 */
4273 static const char *databaseName(const char *zName){
4274   while( zName[-1]!=0 || zName[-2]!=0 || zName[-3]!=0 || zName[-4]!=0 ){
4275     zName--;
4276   }
4277   return zName;
4278 }
4279 
4280 /*
4281 ** Append text z[] to the end of p[].  Return a pointer to the first
4282 ** character after then zero terminator on the new text in p[].
4283 */
4284 static char *appendText(char *p, const char *z){
4285   size_t n = strlen(z);
4286   memcpy(p, z, n+1);
4287   return p+n+1;
4288 }
4289 
4290 /*
4291 ** Allocate memory to hold names for a database, journal file, WAL file,
4292 ** and query parameters.  The pointer returned is valid for use by
4293 ** sqlite3_filename_database() and sqlite3_uri_parameter() and related
4294 ** functions.
4295 **
4296 ** Memory layout must be compatible with that generated by the pager
4297 ** and expected by sqlite3_uri_parameter() and databaseName().
4298 */
4299 char *sqlite3_create_filename(
4300   const char *zDatabase,
4301   const char *zJournal,
4302   const char *zWal,
4303   int nParam,
4304   const char **azParam
4305 ){
4306   sqlite3_int64 nByte;
4307   int i;
4308   char *pResult, *p;
4309   nByte = strlen(zDatabase) + strlen(zJournal) + strlen(zWal) + 10;
4310   for(i=0; i<nParam*2; i++){
4311     nByte += strlen(azParam[i])+1;
4312   }
4313   pResult = p = sqlite3_malloc64( nByte );
4314   if( p==0 ) return 0;
4315   memset(p, 0, 4);
4316   p += 4;
4317   p = appendText(p, zDatabase);
4318   for(i=0; i<nParam*2; i++){
4319     p = appendText(p, azParam[i]);
4320   }
4321   *(p++) = 0;
4322   p = appendText(p, zJournal);
4323   p = appendText(p, zWal);
4324   *(p++) = 0;
4325   *(p++) = 0;
4326   assert( (sqlite3_int64)(p - pResult)==nByte );
4327   return pResult + 4;
4328 }
4329 
4330 /*
4331 ** Free memory obtained from sqlite3_create_filename().  It is a severe
4332 ** error to call this routine with any parameter other than a pointer
4333 ** previously obtained from sqlite3_create_filename() or a NULL pointer.
4334 */
4335 void sqlite3_free_filename(char *p){
4336   if( p==0 ) return;
4337   p = (char*)databaseName(p);
4338   sqlite3_free(p - 4);
4339 }
4340 
4341 
4342 /*
4343 ** This is a utility routine, useful to VFS implementations, that checks
4344 ** to see if a database file was a URI that contained a specific query
4345 ** parameter, and if so obtains the value of the query parameter.
4346 **
4347 ** The zFilename argument is the filename pointer passed into the xOpen()
4348 ** method of a VFS implementation.  The zParam argument is the name of the
4349 ** query parameter we seek.  This routine returns the value of the zParam
4350 ** parameter if it exists.  If the parameter does not exist, this routine
4351 ** returns a NULL pointer.
4352 */
4353 const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam){
4354   if( zFilename==0 || zParam==0 ) return 0;
4355   zFilename = databaseName(zFilename);
4356   return uriParameter(zFilename, zParam);
4357 }
4358 
4359 /*
4360 ** Return a pointer to the name of Nth query parameter of the filename.
4361 */
4362 const char *sqlite3_uri_key(const char *zFilename, int N){
4363   if( zFilename==0 || N<0 ) return 0;
4364   zFilename = databaseName(zFilename);
4365   zFilename += sqlite3Strlen30(zFilename) + 1;
4366   while( zFilename[0] && (N--)>0 ){
4367     zFilename += sqlite3Strlen30(zFilename) + 1;
4368     zFilename += sqlite3Strlen30(zFilename) + 1;
4369   }
4370   return zFilename[0] ? zFilename : 0;
4371 }
4372 
4373 /*
4374 ** Return a boolean value for a query parameter.
4375 */
4376 int sqlite3_uri_boolean(const char *zFilename, const char *zParam, int bDflt){
4377   const char *z = sqlite3_uri_parameter(zFilename, zParam);
4378   bDflt = bDflt!=0;
4379   return z ? sqlite3GetBoolean(z, bDflt) : bDflt;
4380 }
4381 
4382 /*
4383 ** Return a 64-bit integer value for a query parameter.
4384 */
4385 sqlite3_int64 sqlite3_uri_int64(
4386   const char *zFilename,    /* Filename as passed to xOpen */
4387   const char *zParam,       /* URI parameter sought */
4388   sqlite3_int64 bDflt       /* return if parameter is missing */
4389 ){
4390   const char *z = sqlite3_uri_parameter(zFilename, zParam);
4391   sqlite3_int64 v;
4392   if( z && sqlite3DecOrHexToI64(z, &v)==0 ){
4393     bDflt = v;
4394   }
4395   return bDflt;
4396 }
4397 
4398 /*
4399 ** Translate a filename that was handed to a VFS routine into the corresponding
4400 ** database, journal, or WAL file.
4401 **
4402 ** It is an error to pass this routine a filename string that was not
4403 ** passed into the VFS from the SQLite core.  Doing so is similar to
4404 ** passing free() a pointer that was not obtained from malloc() - it is
4405 ** an error that we cannot easily detect but that will likely cause memory
4406 ** corruption.
4407 */
4408 const char *sqlite3_filename_database(const char *zFilename){
4409   return databaseName(zFilename);
4410 }
4411 const char *sqlite3_filename_journal(const char *zFilename){
4412   zFilename = databaseName(zFilename);
4413   zFilename += sqlite3Strlen30(zFilename) + 1;
4414   while( zFilename[0] ){
4415     zFilename += sqlite3Strlen30(zFilename) + 1;
4416     zFilename += sqlite3Strlen30(zFilename) + 1;
4417   }
4418   return zFilename + 1;
4419 }
4420 const char *sqlite3_filename_wal(const char *zFilename){
4421 #ifdef SQLITE_OMIT_WAL
4422   return 0;
4423 #else
4424   zFilename = sqlite3_filename_journal(zFilename);
4425   zFilename += sqlite3Strlen30(zFilename) + 1;
4426   return zFilename;
4427 #endif
4428 }
4429 
4430 /*
4431 ** Return the Btree pointer identified by zDbName.  Return NULL if not found.
4432 */
4433 Btree *sqlite3DbNameToBtree(sqlite3 *db, const char *zDbName){
4434   int iDb = zDbName ? sqlite3FindDbName(db, zDbName) : 0;
4435   return iDb<0 ? 0 : db->aDb[iDb].pBt;
4436 }
4437 
4438 /*
4439 ** Return the filename of the database associated with a database
4440 ** connection.
4441 */
4442 const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName){
4443   Btree *pBt;
4444 #ifdef SQLITE_ENABLE_API_ARMOR
4445   if( !sqlite3SafetyCheckOk(db) ){
4446     (void)SQLITE_MISUSE_BKPT;
4447     return 0;
4448   }
4449 #endif
4450   pBt = sqlite3DbNameToBtree(db, zDbName);
4451   return pBt ? sqlite3BtreeGetFilename(pBt) : 0;
4452 }
4453 
4454 /*
4455 ** Return 1 if database is read-only or 0 if read/write.  Return -1 if
4456 ** no such database exists.
4457 */
4458 int sqlite3_db_readonly(sqlite3 *db, const char *zDbName){
4459   Btree *pBt;
4460 #ifdef SQLITE_ENABLE_API_ARMOR
4461   if( !sqlite3SafetyCheckOk(db) ){
4462     (void)SQLITE_MISUSE_BKPT;
4463     return -1;
4464   }
4465 #endif
4466   pBt = sqlite3DbNameToBtree(db, zDbName);
4467   return pBt ? sqlite3BtreeIsReadonly(pBt) : -1;
4468 }
4469 
4470 #ifdef SQLITE_ENABLE_SNAPSHOT
4471 /*
4472 ** Obtain a snapshot handle for the snapshot of database zDb currently
4473 ** being read by handle db.
4474 */
4475 int sqlite3_snapshot_get(
4476   sqlite3 *db,
4477   const char *zDb,
4478   sqlite3_snapshot **ppSnapshot
4479 ){
4480   int rc = SQLITE_ERROR;
4481 #ifndef SQLITE_OMIT_WAL
4482 
4483 #ifdef SQLITE_ENABLE_API_ARMOR
4484   if( !sqlite3SafetyCheckOk(db) ){
4485     return SQLITE_MISUSE_BKPT;
4486   }
4487 #endif
4488   sqlite3_mutex_enter(db->mutex);
4489 
4490   if( db->autoCommit==0 ){
4491     int iDb = sqlite3FindDbName(db, zDb);
4492     if( iDb==0 || iDb>1 ){
4493       Btree *pBt = db->aDb[iDb].pBt;
4494       if( SQLITE_TXN_WRITE!=sqlite3BtreeTxnState(pBt) ){
4495         rc = sqlite3BtreeBeginTrans(pBt, 0, 0);
4496         if( rc==SQLITE_OK ){
4497           rc = sqlite3PagerSnapshotGet(sqlite3BtreePager(pBt), ppSnapshot);
4498         }
4499       }
4500     }
4501   }
4502 
4503   sqlite3_mutex_leave(db->mutex);
4504 #endif   /* SQLITE_OMIT_WAL */
4505   return rc;
4506 }
4507 
4508 /*
4509 ** Open a read-transaction on the snapshot idendified by pSnapshot.
4510 */
4511 int sqlite3_snapshot_open(
4512   sqlite3 *db,
4513   const char *zDb,
4514   sqlite3_snapshot *pSnapshot
4515 ){
4516   int rc = SQLITE_ERROR;
4517 #ifndef SQLITE_OMIT_WAL
4518 
4519 #ifdef SQLITE_ENABLE_API_ARMOR
4520   if( !sqlite3SafetyCheckOk(db) ){
4521     return SQLITE_MISUSE_BKPT;
4522   }
4523 #endif
4524   sqlite3_mutex_enter(db->mutex);
4525   if( db->autoCommit==0 ){
4526     int iDb;
4527     iDb = sqlite3FindDbName(db, zDb);
4528     if( iDb==0 || iDb>1 ){
4529       Btree *pBt = db->aDb[iDb].pBt;
4530       if( sqlite3BtreeTxnState(pBt)!=SQLITE_TXN_WRITE ){
4531         Pager *pPager = sqlite3BtreePager(pBt);
4532         int bUnlock = 0;
4533         if( sqlite3BtreeTxnState(pBt)!=SQLITE_TXN_NONE ){
4534           if( db->nVdbeActive==0 ){
4535             rc = sqlite3PagerSnapshotCheck(pPager, pSnapshot);
4536             if( rc==SQLITE_OK ){
4537               bUnlock = 1;
4538               rc = sqlite3BtreeCommit(pBt);
4539             }
4540           }
4541         }else{
4542           rc = SQLITE_OK;
4543         }
4544         if( rc==SQLITE_OK ){
4545           rc = sqlite3PagerSnapshotOpen(pPager, pSnapshot);
4546         }
4547         if( rc==SQLITE_OK ){
4548           rc = sqlite3BtreeBeginTrans(pBt, 0, 0);
4549           sqlite3PagerSnapshotOpen(pPager, 0);
4550         }
4551         if( bUnlock ){
4552           sqlite3PagerSnapshotUnlock(pPager);
4553         }
4554       }
4555     }
4556   }
4557 
4558   sqlite3_mutex_leave(db->mutex);
4559 #endif   /* SQLITE_OMIT_WAL */
4560   return rc;
4561 }
4562 
4563 /*
4564 ** Recover as many snapshots as possible from the wal file associated with
4565 ** schema zDb of database db.
4566 */
4567 int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb){
4568   int rc = SQLITE_ERROR;
4569   int iDb;
4570 #ifndef SQLITE_OMIT_WAL
4571 
4572 #ifdef SQLITE_ENABLE_API_ARMOR
4573   if( !sqlite3SafetyCheckOk(db) ){
4574     return SQLITE_MISUSE_BKPT;
4575   }
4576 #endif
4577 
4578   sqlite3_mutex_enter(db->mutex);
4579   iDb = sqlite3FindDbName(db, zDb);
4580   if( iDb==0 || iDb>1 ){
4581     Btree *pBt = db->aDb[iDb].pBt;
4582     if( SQLITE_TXN_NONE==sqlite3BtreeTxnState(pBt) ){
4583       rc = sqlite3BtreeBeginTrans(pBt, 0, 0);
4584       if( rc==SQLITE_OK ){
4585         rc = sqlite3PagerSnapshotRecover(sqlite3BtreePager(pBt));
4586         sqlite3BtreeCommit(pBt);
4587       }
4588     }
4589   }
4590   sqlite3_mutex_leave(db->mutex);
4591 #endif   /* SQLITE_OMIT_WAL */
4592   return rc;
4593 }
4594 
4595 /*
4596 ** Free a snapshot handle obtained from sqlite3_snapshot_get().
4597 */
4598 void sqlite3_snapshot_free(sqlite3_snapshot *pSnapshot){
4599   sqlite3_free(pSnapshot);
4600 }
4601 #endif /* SQLITE_ENABLE_SNAPSHOT */
4602 
4603 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
4604 /*
4605 ** Given the name of a compile-time option, return true if that option
4606 ** was used and false if not.
4607 **
4608 ** The name can optionally begin with "SQLITE_" but the "SQLITE_" prefix
4609 ** is not required for a match.
4610 */
4611 int sqlite3_compileoption_used(const char *zOptName){
4612   int i, n;
4613   int nOpt;
4614   const char **azCompileOpt;
4615 
4616 #if SQLITE_ENABLE_API_ARMOR
4617   if( zOptName==0 ){
4618     (void)SQLITE_MISUSE_BKPT;
4619     return 0;
4620   }
4621 #endif
4622 
4623   azCompileOpt = sqlite3CompileOptions(&nOpt);
4624 
4625   if( sqlite3StrNICmp(zOptName, "SQLITE_", 7)==0 ) zOptName += 7;
4626   n = sqlite3Strlen30(zOptName);
4627 
4628   /* Since nOpt is normally in single digits, a linear search is
4629   ** adequate. No need for a binary search. */
4630   for(i=0; i<nOpt; i++){
4631     if( sqlite3StrNICmp(zOptName, azCompileOpt[i], n)==0
4632      && sqlite3IsIdChar((unsigned char)azCompileOpt[i][n])==0
4633     ){
4634       return 1;
4635     }
4636   }
4637   return 0;
4638 }
4639 
4640 /*
4641 ** Return the N-th compile-time option string.  If N is out of range,
4642 ** return a NULL pointer.
4643 */
4644 const char *sqlite3_compileoption_get(int N){
4645   int nOpt;
4646   const char **azCompileOpt;
4647   azCompileOpt = sqlite3CompileOptions(&nOpt);
4648   if( N>=0 && N<nOpt ){
4649     return azCompileOpt[N];
4650   }
4651   return 0;
4652 }
4653 #endif /* SQLITE_OMIT_COMPILEOPTION_DIAGS */
4654