000001  /*
000002  ** 2001 September 15
000003  **
000004  ** The author disclaims copyright to this source code.  In place of
000005  ** a legal notice, here is a blessing:
000006  **
000007  **    May you do good and not evil.
000008  **    May you find forgiveness for yourself and forgive others.
000009  **    May you share freely, never taking more than you give.
000010  **
000011  *************************************************************************
000012  ** Main file for the SQLite library.  The routines in this file
000013  ** implement the programmer interface to the library.  Routines in
000014  ** other files are for internal use by SQLite and should not be
000015  ** accessed by users of the library.
000016  */
000017  #include "sqliteInt.h"
000018  
000019  #ifdef SQLITE_ENABLE_FTS3
000020  # include "fts3.h"
000021  #endif
000022  #ifdef SQLITE_ENABLE_RTREE
000023  # include "rtree.h"
000024  #endif
000025  #if defined(SQLITE_ENABLE_ICU) || defined(SQLITE_ENABLE_ICU_COLLATIONS)
000026  # include "sqliteicu.h"
000027  #endif
000028  #ifdef SQLITE_ENABLE_JSON1
000029  int sqlite3Json1Init(sqlite3*);
000030  #endif
000031  #ifdef SQLITE_ENABLE_STMTVTAB
000032  int sqlite3StmtVtabInit(sqlite3*);
000033  #endif
000034  #ifdef SQLITE_ENABLE_FTS5
000035  int sqlite3Fts5Init(sqlite3*);
000036  #endif
000037  
000038  #ifndef SQLITE_AMALGAMATION
000039  /* IMPLEMENTATION-OF: R-46656-45156 The sqlite3_version[] string constant
000040  ** contains the text of SQLITE_VERSION macro. 
000041  */
000042  const char sqlite3_version[] = SQLITE_VERSION;
000043  #endif
000044  
000045  /* IMPLEMENTATION-OF: R-53536-42575 The sqlite3_libversion() function returns
000046  ** a pointer to the to the sqlite3_version[] string constant. 
000047  */
000048  const char *sqlite3_libversion(void){ return sqlite3_version; }
000049  
000050  /* IMPLEMENTATION-OF: R-25063-23286 The sqlite3_sourceid() function returns a
000051  ** pointer to a string constant whose value is the same as the
000052  ** SQLITE_SOURCE_ID C preprocessor macro. Except if SQLite is built using
000053  ** an edited copy of the amalgamation, then the last four characters of
000054  ** the hash might be different from SQLITE_SOURCE_ID.
000055  */
000056  const char *sqlite3_sourceid(void){ return SQLITE_SOURCE_ID; }
000057  
000058  /* IMPLEMENTATION-OF: R-35210-63508 The sqlite3_libversion_number() function
000059  ** returns an integer equal to SQLITE_VERSION_NUMBER.
000060  */
000061  int sqlite3_libversion_number(void){ return SQLITE_VERSION_NUMBER; }
000062  
000063  /* IMPLEMENTATION-OF: R-20790-14025 The sqlite3_threadsafe() function returns
000064  ** zero if and only if SQLite was compiled with mutexing code omitted due to
000065  ** the SQLITE_THREADSAFE compile-time option being set to 0.
000066  */
000067  int sqlite3_threadsafe(void){ return SQLITE_THREADSAFE; }
000068  
000069  /*
000070  ** When compiling the test fixture or with debugging enabled (on Win32),
000071  ** this variable being set to non-zero will cause OSTRACE macros to emit
000072  ** extra diagnostic information.
000073  */
000074  #ifdef SQLITE_HAVE_OS_TRACE
000075  # ifndef SQLITE_DEBUG_OS_TRACE
000076  #   define SQLITE_DEBUG_OS_TRACE 0
000077  # endif
000078    int sqlite3OSTrace = SQLITE_DEBUG_OS_TRACE;
000079  #endif
000080  
000081  #if !defined(SQLITE_OMIT_TRACE) && defined(SQLITE_ENABLE_IOTRACE)
000082  /*
000083  ** If the following function pointer is not NULL and if
000084  ** SQLITE_ENABLE_IOTRACE is enabled, then messages describing
000085  ** I/O active are written using this function.  These messages
000086  ** are intended for debugging activity only.
000087  */
000088  SQLITE_API void (SQLITE_CDECL *sqlite3IoTrace)(const char*, ...) = 0;
000089  #endif
000090  
000091  /*
000092  ** If the following global variable points to a string which is the
000093  ** name of a directory, then that directory will be used to store
000094  ** temporary files.
000095  **
000096  ** See also the "PRAGMA temp_store_directory" SQL command.
000097  */
000098  char *sqlite3_temp_directory = 0;
000099  
000100  /*
000101  ** If the following global variable points to a string which is the
000102  ** name of a directory, then that directory will be used to store
000103  ** all database files specified with a relative pathname.
000104  **
000105  ** See also the "PRAGMA data_store_directory" SQL command.
000106  */
000107  char *sqlite3_data_directory = 0;
000108  
000109  /*
000110  ** Initialize SQLite.  
000111  **
000112  ** This routine must be called to initialize the memory allocation,
000113  ** VFS, and mutex subsystems prior to doing any serious work with
000114  ** SQLite.  But as long as you do not compile with SQLITE_OMIT_AUTOINIT
000115  ** this routine will be called automatically by key routines such as
000116  ** sqlite3_open().  
000117  **
000118  ** This routine is a no-op except on its very first call for the process,
000119  ** or for the first call after a call to sqlite3_shutdown.
000120  **
000121  ** The first thread to call this routine runs the initialization to
000122  ** completion.  If subsequent threads call this routine before the first
000123  ** thread has finished the initialization process, then the subsequent
000124  ** threads must block until the first thread finishes with the initialization.
000125  **
000126  ** The first thread might call this routine recursively.  Recursive
000127  ** calls to this routine should not block, of course.  Otherwise the
000128  ** initialization process would never complete.
000129  **
000130  ** Let X be the first thread to enter this routine.  Let Y be some other
000131  ** thread.  Then while the initial invocation of this routine by X is
000132  ** incomplete, it is required that:
000133  **
000134  **    *  Calls to this routine from Y must block until the outer-most
000135  **       call by X completes.
000136  **
000137  **    *  Recursive calls to this routine from thread X return immediately
000138  **       without blocking.
000139  */
000140  int sqlite3_initialize(void){
000141    MUTEX_LOGIC( sqlite3_mutex *pMaster; )       /* The main static mutex */
000142    int rc;                                      /* Result code */
000143  #ifdef SQLITE_EXTRA_INIT
000144    int bRunExtraInit = 0;                       /* Extra initialization needed */
000145  #endif
000146  
000147  #ifdef SQLITE_OMIT_WSD
000148    rc = sqlite3_wsd_init(4096, 24);
000149    if( rc!=SQLITE_OK ){
000150      return rc;
000151    }
000152  #endif
000153  
000154    /* If the following assert() fails on some obscure processor/compiler
000155    ** combination, the work-around is to set the correct pointer
000156    ** size at compile-time using -DSQLITE_PTRSIZE=n compile-time option */
000157    assert( SQLITE_PTRSIZE==sizeof(char*) );
000158  
000159    /* If SQLite is already completely initialized, then this call
000160    ** to sqlite3_initialize() should be a no-op.  But the initialization
000161    ** must be complete.  So isInit must not be set until the very end
000162    ** of this routine.
000163    */
000164    if( sqlite3GlobalConfig.isInit ) return SQLITE_OK;
000165  
000166    /* Make sure the mutex subsystem is initialized.  If unable to 
000167    ** initialize the mutex subsystem, return early with the error.
000168    ** If the system is so sick that we are unable to allocate a mutex,
000169    ** there is not much SQLite is going to be able to do.
000170    **
000171    ** The mutex subsystem must take care of serializing its own
000172    ** initialization.
000173    */
000174    rc = sqlite3MutexInit();
000175    if( rc ) return rc;
000176  
000177    /* Initialize the malloc() system and the recursive pInitMutex mutex.
000178    ** This operation is protected by the STATIC_MASTER mutex.  Note that
000179    ** MutexAlloc() is called for a static mutex prior to initializing the
000180    ** malloc subsystem - this implies that the allocation of a static
000181    ** mutex must not require support from the malloc subsystem.
000182    */
000183    MUTEX_LOGIC( pMaster = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER); )
000184    sqlite3_mutex_enter(pMaster);
000185    sqlite3GlobalConfig.isMutexInit = 1;
000186    if( !sqlite3GlobalConfig.isMallocInit ){
000187      rc = sqlite3MallocInit();
000188    }
000189    if( rc==SQLITE_OK ){
000190      sqlite3GlobalConfig.isMallocInit = 1;
000191      if( !sqlite3GlobalConfig.pInitMutex ){
000192        sqlite3GlobalConfig.pInitMutex =
000193             sqlite3MutexAlloc(SQLITE_MUTEX_RECURSIVE);
000194        if( sqlite3GlobalConfig.bCoreMutex && !sqlite3GlobalConfig.pInitMutex ){
000195          rc = SQLITE_NOMEM_BKPT;
000196        }
000197      }
000198    }
000199    if( rc==SQLITE_OK ){
000200      sqlite3GlobalConfig.nRefInitMutex++;
000201    }
000202    sqlite3_mutex_leave(pMaster);
000203  
000204    /* If rc is not SQLITE_OK at this point, then either the malloc
000205    ** subsystem could not be initialized or the system failed to allocate
000206    ** the pInitMutex mutex. Return an error in either case.  */
000207    if( rc!=SQLITE_OK ){
000208      return rc;
000209    }
000210  
000211    /* Do the rest of the initialization under the recursive mutex so
000212    ** that we will be able to handle recursive calls into
000213    ** sqlite3_initialize().  The recursive calls normally come through
000214    ** sqlite3_os_init() when it invokes sqlite3_vfs_register(), but other
000215    ** recursive calls might also be possible.
000216    **
000217    ** IMPLEMENTATION-OF: R-00140-37445 SQLite automatically serializes calls
000218    ** to the xInit method, so the xInit method need not be threadsafe.
000219    **
000220    ** The following mutex is what serializes access to the appdef pcache xInit
000221    ** methods.  The sqlite3_pcache_methods.xInit() all is embedded in the
000222    ** call to sqlite3PcacheInitialize().
000223    */
000224    sqlite3_mutex_enter(sqlite3GlobalConfig.pInitMutex);
000225    if( sqlite3GlobalConfig.isInit==0 && sqlite3GlobalConfig.inProgress==0 ){
000226      sqlite3GlobalConfig.inProgress = 1;
000227  #ifdef SQLITE_ENABLE_SQLLOG
000228      {
000229        extern void sqlite3_init_sqllog(void);
000230        sqlite3_init_sqllog();
000231      }
000232  #endif
000233      memset(&sqlite3BuiltinFunctions, 0, sizeof(sqlite3BuiltinFunctions));
000234      sqlite3RegisterBuiltinFunctions();
000235      if( sqlite3GlobalConfig.isPCacheInit==0 ){
000236        rc = sqlite3PcacheInitialize();
000237      }
000238      if( rc==SQLITE_OK ){
000239        sqlite3GlobalConfig.isPCacheInit = 1;
000240        rc = sqlite3OsInit();
000241      }
000242  #ifdef SQLITE_ENABLE_DESERIALIZE
000243      if( rc==SQLITE_OK ){
000244        rc = sqlite3MemdbInit();
000245      }
000246  #endif
000247      if( rc==SQLITE_OK ){
000248        sqlite3PCacheBufferSetup( sqlite3GlobalConfig.pPage, 
000249            sqlite3GlobalConfig.szPage, sqlite3GlobalConfig.nPage);
000250        sqlite3GlobalConfig.isInit = 1;
000251  #ifdef SQLITE_EXTRA_INIT
000252        bRunExtraInit = 1;
000253  #endif
000254      }
000255      sqlite3GlobalConfig.inProgress = 0;
000256    }
000257    sqlite3_mutex_leave(sqlite3GlobalConfig.pInitMutex);
000258  
000259    /* Go back under the static mutex and clean up the recursive
000260    ** mutex to prevent a resource leak.
000261    */
000262    sqlite3_mutex_enter(pMaster);
000263    sqlite3GlobalConfig.nRefInitMutex--;
000264    if( sqlite3GlobalConfig.nRefInitMutex<=0 ){
000265      assert( sqlite3GlobalConfig.nRefInitMutex==0 );
000266      sqlite3_mutex_free(sqlite3GlobalConfig.pInitMutex);
000267      sqlite3GlobalConfig.pInitMutex = 0;
000268    }
000269    sqlite3_mutex_leave(pMaster);
000270  
000271    /* The following is just a sanity check to make sure SQLite has
000272    ** been compiled correctly.  It is important to run this code, but
000273    ** we don't want to run it too often and soak up CPU cycles for no
000274    ** reason.  So we run it once during initialization.
000275    */
000276  #ifndef NDEBUG
000277  #ifndef SQLITE_OMIT_FLOATING_POINT
000278    /* This section of code's only "output" is via assert() statements. */
000279    if( rc==SQLITE_OK ){
000280      u64 x = (((u64)1)<<63)-1;
000281      double y;
000282      assert(sizeof(x)==8);
000283      assert(sizeof(x)==sizeof(y));
000284      memcpy(&y, &x, 8);
000285      assert( sqlite3IsNaN(y) );
000286    }
000287  #endif
000288  #endif
000289  
000290    /* Do extra initialization steps requested by the SQLITE_EXTRA_INIT
000291    ** compile-time option.
000292    */
000293  #ifdef SQLITE_EXTRA_INIT
000294    if( bRunExtraInit ){
000295      int SQLITE_EXTRA_INIT(const char*);
000296      rc = SQLITE_EXTRA_INIT(0);
000297    }
000298  #endif
000299  
000300    return rc;
000301  }
000302  
000303  /*
000304  ** Undo the effects of sqlite3_initialize().  Must not be called while
000305  ** there are outstanding database connections or memory allocations or
000306  ** while any part of SQLite is otherwise in use in any thread.  This
000307  ** routine is not threadsafe.  But it is safe to invoke this routine
000308  ** on when SQLite is already shut down.  If SQLite is already shut down
000309  ** when this routine is invoked, then this routine is a harmless no-op.
000310  */
000311  int sqlite3_shutdown(void){
000312  #ifdef SQLITE_OMIT_WSD
000313    int rc = sqlite3_wsd_init(4096, 24);
000314    if( rc!=SQLITE_OK ){
000315      return rc;
000316    }
000317  #endif
000318  
000319    if( sqlite3GlobalConfig.isInit ){
000320  #ifdef SQLITE_EXTRA_SHUTDOWN
000321      void SQLITE_EXTRA_SHUTDOWN(void);
000322      SQLITE_EXTRA_SHUTDOWN();
000323  #endif
000324      sqlite3_os_end();
000325      sqlite3_reset_auto_extension();
000326      sqlite3GlobalConfig.isInit = 0;
000327    }
000328    if( sqlite3GlobalConfig.isPCacheInit ){
000329      sqlite3PcacheShutdown();
000330      sqlite3GlobalConfig.isPCacheInit = 0;
000331    }
000332    if( sqlite3GlobalConfig.isMallocInit ){
000333      sqlite3MallocEnd();
000334      sqlite3GlobalConfig.isMallocInit = 0;
000335  
000336  #ifndef SQLITE_OMIT_SHUTDOWN_DIRECTORIES
000337      /* The heap subsystem has now been shutdown and these values are supposed
000338      ** to be NULL or point to memory that was obtained from sqlite3_malloc(),
000339      ** which would rely on that heap subsystem; therefore, make sure these
000340      ** values cannot refer to heap memory that was just invalidated when the
000341      ** heap subsystem was shutdown.  This is only done if the current call to
000342      ** this function resulted in the heap subsystem actually being shutdown.
000343      */
000344      sqlite3_data_directory = 0;
000345      sqlite3_temp_directory = 0;
000346  #endif
000347    }
000348    if( sqlite3GlobalConfig.isMutexInit ){
000349      sqlite3MutexEnd();
000350      sqlite3GlobalConfig.isMutexInit = 0;
000351    }
000352  
000353    return SQLITE_OK;
000354  }
000355  
000356  /*
000357  ** This API allows applications to modify the global configuration of
000358  ** the SQLite library at run-time.
000359  **
000360  ** This routine should only be called when there are no outstanding
000361  ** database connections or memory allocations.  This routine is not
000362  ** threadsafe.  Failure to heed these warnings can lead to unpredictable
000363  ** behavior.
000364  */
000365  int sqlite3_config(int op, ...){
000366    va_list ap;
000367    int rc = SQLITE_OK;
000368  
000369    /* sqlite3_config() shall return SQLITE_MISUSE if it is invoked while
000370    ** the SQLite library is in use. */
000371    if( sqlite3GlobalConfig.isInit ) return SQLITE_MISUSE_BKPT;
000372  
000373    va_start(ap, op);
000374    switch( op ){
000375  
000376      /* Mutex configuration options are only available in a threadsafe
000377      ** compile.
000378      */
000379  #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0  /* IMP: R-54466-46756 */
000380      case SQLITE_CONFIG_SINGLETHREAD: {
000381        /* EVIDENCE-OF: R-02748-19096 This option sets the threading mode to
000382        ** Single-thread. */
000383        sqlite3GlobalConfig.bCoreMutex = 0;  /* Disable mutex on core */
000384        sqlite3GlobalConfig.bFullMutex = 0;  /* Disable mutex on connections */
000385        break;
000386      }
000387  #endif
000388  #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-20520-54086 */
000389      case SQLITE_CONFIG_MULTITHREAD: {
000390        /* EVIDENCE-OF: R-14374-42468 This option sets the threading mode to
000391        ** Multi-thread. */
000392        sqlite3GlobalConfig.bCoreMutex = 1;  /* Enable mutex on core */
000393        sqlite3GlobalConfig.bFullMutex = 0;  /* Disable mutex on connections */
000394        break;
000395      }
000396  #endif
000397  #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-59593-21810 */
000398      case SQLITE_CONFIG_SERIALIZED: {
000399        /* EVIDENCE-OF: R-41220-51800 This option sets the threading mode to
000400        ** Serialized. */
000401        sqlite3GlobalConfig.bCoreMutex = 1;  /* Enable mutex on core */
000402        sqlite3GlobalConfig.bFullMutex = 1;  /* Enable mutex on connections */
000403        break;
000404      }
000405  #endif
000406  #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-63666-48755 */
000407      case SQLITE_CONFIG_MUTEX: {
000408        /* Specify an alternative mutex implementation */
000409        sqlite3GlobalConfig.mutex = *va_arg(ap, sqlite3_mutex_methods*);
000410        break;
000411      }
000412  #endif
000413  #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-14450-37597 */
000414      case SQLITE_CONFIG_GETMUTEX: {
000415        /* Retrieve the current mutex implementation */
000416        *va_arg(ap, sqlite3_mutex_methods*) = sqlite3GlobalConfig.mutex;
000417        break;
000418      }
000419  #endif
000420  
000421      case SQLITE_CONFIG_MALLOC: {
000422        /* EVIDENCE-OF: R-55594-21030 The SQLITE_CONFIG_MALLOC option takes a
000423        ** single argument which is a pointer to an instance of the
000424        ** sqlite3_mem_methods structure. The argument specifies alternative
000425        ** low-level memory allocation routines to be used in place of the memory
000426        ** allocation routines built into SQLite. */
000427        sqlite3GlobalConfig.m = *va_arg(ap, sqlite3_mem_methods*);
000428        break;
000429      }
000430      case SQLITE_CONFIG_GETMALLOC: {
000431        /* EVIDENCE-OF: R-51213-46414 The SQLITE_CONFIG_GETMALLOC option takes a
000432        ** single argument which is a pointer to an instance of the
000433        ** sqlite3_mem_methods structure. The sqlite3_mem_methods structure is
000434        ** filled with the currently defined memory allocation routines. */
000435        if( sqlite3GlobalConfig.m.xMalloc==0 ) sqlite3MemSetDefault();
000436        *va_arg(ap, sqlite3_mem_methods*) = sqlite3GlobalConfig.m;
000437        break;
000438      }
000439      case SQLITE_CONFIG_MEMSTATUS: {
000440        /* EVIDENCE-OF: R-61275-35157 The SQLITE_CONFIG_MEMSTATUS option takes
000441        ** single argument of type int, interpreted as a boolean, which enables
000442        ** or disables the collection of memory allocation statistics. */
000443        sqlite3GlobalConfig.bMemstat = va_arg(ap, int);
000444        break;
000445      }
000446      case SQLITE_CONFIG_SMALL_MALLOC: {
000447        sqlite3GlobalConfig.bSmallMalloc = va_arg(ap, int);
000448        break;
000449      }
000450      case SQLITE_CONFIG_PAGECACHE: {
000451        /* EVIDENCE-OF: R-18761-36601 There are three arguments to
000452        ** SQLITE_CONFIG_PAGECACHE: A pointer to 8-byte aligned memory (pMem),
000453        ** the size of each page cache line (sz), and the number of cache lines
000454        ** (N). */
000455        sqlite3GlobalConfig.pPage = va_arg(ap, void*);
000456        sqlite3GlobalConfig.szPage = va_arg(ap, int);
000457        sqlite3GlobalConfig.nPage = va_arg(ap, int);
000458        break;
000459      }
000460      case SQLITE_CONFIG_PCACHE_HDRSZ: {
000461        /* EVIDENCE-OF: R-39100-27317 The SQLITE_CONFIG_PCACHE_HDRSZ option takes
000462        ** a single parameter which is a pointer to an integer and writes into
000463        ** that integer the number of extra bytes per page required for each page
000464        ** in SQLITE_CONFIG_PAGECACHE. */
000465        *va_arg(ap, int*) = 
000466            sqlite3HeaderSizeBtree() +
000467            sqlite3HeaderSizePcache() +
000468            sqlite3HeaderSizePcache1();
000469        break;
000470      }
000471  
000472      case SQLITE_CONFIG_PCACHE: {
000473        /* no-op */
000474        break;
000475      }
000476      case SQLITE_CONFIG_GETPCACHE: {
000477        /* now an error */
000478        rc = SQLITE_ERROR;
000479        break;
000480      }
000481  
000482      case SQLITE_CONFIG_PCACHE2: {
000483        /* EVIDENCE-OF: R-63325-48378 The SQLITE_CONFIG_PCACHE2 option takes a
000484        ** single argument which is a pointer to an sqlite3_pcache_methods2
000485        ** object. This object specifies the interface to a custom page cache
000486        ** implementation. */
000487        sqlite3GlobalConfig.pcache2 = *va_arg(ap, sqlite3_pcache_methods2*);
000488        break;
000489      }
000490      case SQLITE_CONFIG_GETPCACHE2: {
000491        /* EVIDENCE-OF: R-22035-46182 The SQLITE_CONFIG_GETPCACHE2 option takes a
000492        ** single argument which is a pointer to an sqlite3_pcache_methods2
000493        ** object. SQLite copies of the current page cache implementation into
000494        ** that object. */
000495        if( sqlite3GlobalConfig.pcache2.xInit==0 ){
000496          sqlite3PCacheSetDefault();
000497        }
000498        *va_arg(ap, sqlite3_pcache_methods2*) = sqlite3GlobalConfig.pcache2;
000499        break;
000500      }
000501  
000502  /* EVIDENCE-OF: R-06626-12911 The SQLITE_CONFIG_HEAP option is only
000503  ** available if SQLite is compiled with either SQLITE_ENABLE_MEMSYS3 or
000504  ** SQLITE_ENABLE_MEMSYS5 and returns SQLITE_ERROR if invoked otherwise. */
000505  #if defined(SQLITE_ENABLE_MEMSYS3) || defined(SQLITE_ENABLE_MEMSYS5)
000506      case SQLITE_CONFIG_HEAP: {
000507        /* EVIDENCE-OF: R-19854-42126 There are three arguments to
000508        ** SQLITE_CONFIG_HEAP: An 8-byte aligned pointer to the memory, the
000509        ** number of bytes in the memory buffer, and the minimum allocation size.
000510        */
000511        sqlite3GlobalConfig.pHeap = va_arg(ap, void*);
000512        sqlite3GlobalConfig.nHeap = va_arg(ap, int);
000513        sqlite3GlobalConfig.mnReq = va_arg(ap, int);
000514  
000515        if( sqlite3GlobalConfig.mnReq<1 ){
000516          sqlite3GlobalConfig.mnReq = 1;
000517        }else if( sqlite3GlobalConfig.mnReq>(1<<12) ){
000518          /* cap min request size at 2^12 */
000519          sqlite3GlobalConfig.mnReq = (1<<12);
000520        }
000521  
000522        if( sqlite3GlobalConfig.pHeap==0 ){
000523          /* EVIDENCE-OF: R-49920-60189 If the first pointer (the memory pointer)
000524          ** is NULL, then SQLite reverts to using its default memory allocator
000525          ** (the system malloc() implementation), undoing any prior invocation of
000526          ** SQLITE_CONFIG_MALLOC.
000527          **
000528          ** Setting sqlite3GlobalConfig.m to all zeros will cause malloc to
000529          ** revert to its default implementation when sqlite3_initialize() is run
000530          */
000531          memset(&sqlite3GlobalConfig.m, 0, sizeof(sqlite3GlobalConfig.m));
000532        }else{
000533          /* EVIDENCE-OF: R-61006-08918 If the memory pointer is not NULL then the
000534          ** alternative memory allocator is engaged to handle all of SQLites
000535          ** memory allocation needs. */
000536  #ifdef SQLITE_ENABLE_MEMSYS3
000537          sqlite3GlobalConfig.m = *sqlite3MemGetMemsys3();
000538  #endif
000539  #ifdef SQLITE_ENABLE_MEMSYS5
000540          sqlite3GlobalConfig.m = *sqlite3MemGetMemsys5();
000541  #endif
000542        }
000543        break;
000544      }
000545  #endif
000546  
000547      case SQLITE_CONFIG_LOOKASIDE: {
000548        sqlite3GlobalConfig.szLookaside = va_arg(ap, int);
000549        sqlite3GlobalConfig.nLookaside = va_arg(ap, int);
000550        break;
000551      }
000552      
000553      /* Record a pointer to the logger function and its first argument.
000554      ** The default is NULL.  Logging is disabled if the function pointer is
000555      ** NULL.
000556      */
000557      case SQLITE_CONFIG_LOG: {
000558        /* MSVC is picky about pulling func ptrs from va lists.
000559        ** http://support.microsoft.com/kb/47961
000560        ** sqlite3GlobalConfig.xLog = va_arg(ap, void(*)(void*,int,const char*));
000561        */
000562        typedef void(*LOGFUNC_t)(void*,int,const char*);
000563        sqlite3GlobalConfig.xLog = va_arg(ap, LOGFUNC_t);
000564        sqlite3GlobalConfig.pLogArg = va_arg(ap, void*);
000565        break;
000566      }
000567  
000568      /* EVIDENCE-OF: R-55548-33817 The compile-time setting for URI filenames
000569      ** can be changed at start-time using the
000570      ** sqlite3_config(SQLITE_CONFIG_URI,1) or
000571      ** sqlite3_config(SQLITE_CONFIG_URI,0) configuration calls.
000572      */
000573      case SQLITE_CONFIG_URI: {
000574        /* EVIDENCE-OF: R-25451-61125 The SQLITE_CONFIG_URI option takes a single
000575        ** argument of type int. If non-zero, then URI handling is globally
000576        ** enabled. If the parameter is zero, then URI handling is globally
000577        ** disabled. */
000578        sqlite3GlobalConfig.bOpenUri = va_arg(ap, int);
000579        break;
000580      }
000581  
000582      case SQLITE_CONFIG_COVERING_INDEX_SCAN: {
000583        /* EVIDENCE-OF: R-36592-02772 The SQLITE_CONFIG_COVERING_INDEX_SCAN
000584        ** option takes a single integer argument which is interpreted as a
000585        ** boolean in order to enable or disable the use of covering indices for
000586        ** full table scans in the query optimizer. */
000587        sqlite3GlobalConfig.bUseCis = va_arg(ap, int);
000588        break;
000589      }
000590  
000591  #ifdef SQLITE_ENABLE_SQLLOG
000592      case SQLITE_CONFIG_SQLLOG: {
000593        typedef void(*SQLLOGFUNC_t)(void*, sqlite3*, const char*, int);
000594        sqlite3GlobalConfig.xSqllog = va_arg(ap, SQLLOGFUNC_t);
000595        sqlite3GlobalConfig.pSqllogArg = va_arg(ap, void *);
000596        break;
000597      }
000598  #endif
000599  
000600      case SQLITE_CONFIG_MMAP_SIZE: {
000601        /* EVIDENCE-OF: R-58063-38258 SQLITE_CONFIG_MMAP_SIZE takes two 64-bit
000602        ** integer (sqlite3_int64) values that are the default mmap size limit
000603        ** (the default setting for PRAGMA mmap_size) and the maximum allowed
000604        ** mmap size limit. */
000605        sqlite3_int64 szMmap = va_arg(ap, sqlite3_int64);
000606        sqlite3_int64 mxMmap = va_arg(ap, sqlite3_int64);
000607        /* EVIDENCE-OF: R-53367-43190 If either argument to this option is
000608        ** negative, then that argument is changed to its compile-time default.
000609        **
000610        ** EVIDENCE-OF: R-34993-45031 The maximum allowed mmap size will be
000611        ** silently truncated if necessary so that it does not exceed the
000612        ** compile-time maximum mmap size set by the SQLITE_MAX_MMAP_SIZE
000613        ** compile-time option.
000614        */
000615        if( mxMmap<0 || mxMmap>SQLITE_MAX_MMAP_SIZE ){
000616          mxMmap = SQLITE_MAX_MMAP_SIZE;
000617        }
000618        if( szMmap<0 ) szMmap = SQLITE_DEFAULT_MMAP_SIZE;
000619        if( szMmap>mxMmap) szMmap = mxMmap;
000620        sqlite3GlobalConfig.mxMmap = mxMmap;
000621        sqlite3GlobalConfig.szMmap = szMmap;
000622        break;
000623      }
000624  
000625  #if SQLITE_OS_WIN && defined(SQLITE_WIN32_MALLOC) /* IMP: R-04780-55815 */
000626      case SQLITE_CONFIG_WIN32_HEAPSIZE: {
000627        /* EVIDENCE-OF: R-34926-03360 SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit
000628        ** unsigned integer value that specifies the maximum size of the created
000629        ** heap. */
000630        sqlite3GlobalConfig.nHeap = va_arg(ap, int);
000631        break;
000632      }
000633  #endif
000634  
000635      case SQLITE_CONFIG_PMASZ: {
000636        sqlite3GlobalConfig.szPma = va_arg(ap, unsigned int);
000637        break;
000638      }
000639  
000640      case SQLITE_CONFIG_STMTJRNL_SPILL: {
000641        sqlite3GlobalConfig.nStmtSpill = va_arg(ap, int);
000642        break;
000643      }
000644  
000645  #ifdef SQLITE_ENABLE_SORTER_REFERENCES
000646      case SQLITE_CONFIG_SORTERREF_SIZE: {
000647        int iVal = va_arg(ap, int);
000648        if( iVal<0 ){
000649          iVal = SQLITE_DEFAULT_SORTERREF_SIZE;
000650        }
000651        sqlite3GlobalConfig.szSorterRef = (u32)iVal;
000652        break;
000653      }
000654  #endif /* SQLITE_ENABLE_SORTER_REFERENCES */
000655  
000656  #ifdef SQLITE_ENABLE_DESERIALIZE
000657      case SQLITE_CONFIG_MEMDB_MAXSIZE: {
000658        sqlite3GlobalConfig.mxMemdbSize = va_arg(ap, sqlite3_int64);
000659        break;
000660      }
000661  #endif /* SQLITE_ENABLE_DESERIALIZE */
000662  
000663      default: {
000664        rc = SQLITE_ERROR;
000665        break;
000666      }
000667    }
000668    va_end(ap);
000669    return rc;
000670  }
000671  
000672  /*
000673  ** Set up the lookaside buffers for a database connection.
000674  ** Return SQLITE_OK on success.  
000675  ** If lookaside is already active, return SQLITE_BUSY.
000676  **
000677  ** The sz parameter is the number of bytes in each lookaside slot.
000678  ** The cnt parameter is the number of slots.  If pStart is NULL the
000679  ** space for the lookaside memory is obtained from sqlite3_malloc().
000680  ** If pStart is not NULL then it is sz*cnt bytes of memory to use for
000681  ** the lookaside memory.
000682  */
000683  static int setupLookaside(sqlite3 *db, void *pBuf, int sz, int cnt){
000684  #ifndef SQLITE_OMIT_LOOKASIDE
000685    void *pStart;
000686    
000687    if( sqlite3LookasideUsed(db,0)>0 ){
000688      return SQLITE_BUSY;
000689    }
000690    /* Free any existing lookaside buffer for this handle before
000691    ** allocating a new one so we don't have to have space for 
000692    ** both at the same time.
000693    */
000694    if( db->lookaside.bMalloced ){
000695      sqlite3_free(db->lookaside.pStart);
000696    }
000697    /* The size of a lookaside slot after ROUNDDOWN8 needs to be larger
000698    ** than a pointer to be useful.
000699    */
000700    sz = ROUNDDOWN8(sz);  /* IMP: R-33038-09382 */
000701    if( sz<=(int)sizeof(LookasideSlot*) ) sz = 0;
000702    if( cnt<0 ) cnt = 0;
000703    if( sz==0 || cnt==0 ){
000704      sz = 0;
000705      pStart = 0;
000706    }else if( pBuf==0 ){
000707      sqlite3BeginBenignMalloc();
000708      pStart = sqlite3Malloc( sz*(sqlite3_int64)cnt );  /* IMP: R-61949-35727 */
000709      sqlite3EndBenignMalloc();
000710      if( pStart ) cnt = sqlite3MallocSize(pStart)/sz;
000711    }else{
000712      pStart = pBuf;
000713    }
000714    db->lookaside.pStart = pStart;
000715    db->lookaside.pInit = 0;
000716    db->lookaside.pFree = 0;
000717    db->lookaside.sz = (u16)sz;
000718    db->lookaside.szTrue = (u16)sz;
000719    if( pStart ){
000720      int i;
000721      LookasideSlot *p;
000722      assert( sz > (int)sizeof(LookasideSlot*) );
000723      db->lookaside.nSlot = cnt;
000724      p = (LookasideSlot*)pStart;
000725      for(i=cnt-1; i>=0; i--){
000726        p->pNext = db->lookaside.pInit;
000727        db->lookaside.pInit = p;
000728        p = (LookasideSlot*)&((u8*)p)[sz];
000729      }
000730      db->lookaside.pEnd = p;
000731      db->lookaside.bDisable = 0;
000732      db->lookaside.bMalloced = pBuf==0 ?1:0;
000733    }else{
000734      db->lookaside.pStart = db;
000735      db->lookaside.pEnd = db;
000736      db->lookaside.bDisable = 1;
000737      db->lookaside.sz = 0;
000738      db->lookaside.bMalloced = 0;
000739      db->lookaside.nSlot = 0;
000740    }
000741  #endif /* SQLITE_OMIT_LOOKASIDE */
000742    return SQLITE_OK;
000743  }
000744  
000745  /*
000746  ** Return the mutex associated with a database connection.
000747  */
000748  sqlite3_mutex *sqlite3_db_mutex(sqlite3 *db){
000749  #ifdef SQLITE_ENABLE_API_ARMOR
000750    if( !sqlite3SafetyCheckOk(db) ){
000751      (void)SQLITE_MISUSE_BKPT;
000752      return 0;
000753    }
000754  #endif
000755    return db->mutex;
000756  }
000757  
000758  /*
000759  ** Free up as much memory as we can from the given database
000760  ** connection.
000761  */
000762  int sqlite3_db_release_memory(sqlite3 *db){
000763    int i;
000764  
000765  #ifdef SQLITE_ENABLE_API_ARMOR
000766    if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
000767  #endif
000768    sqlite3_mutex_enter(db->mutex);
000769    sqlite3BtreeEnterAll(db);
000770    for(i=0; i<db->nDb; i++){
000771      Btree *pBt = db->aDb[i].pBt;
000772      if( pBt ){
000773        Pager *pPager = sqlite3BtreePager(pBt);
000774        sqlite3PagerShrink(pPager);
000775      }
000776    }
000777    sqlite3BtreeLeaveAll(db);
000778    sqlite3_mutex_leave(db->mutex);
000779    return SQLITE_OK;
000780  }
000781  
000782  /*
000783  ** Flush any dirty pages in the pager-cache for any attached database
000784  ** to disk.
000785  */
000786  int sqlite3_db_cacheflush(sqlite3 *db){
000787    int i;
000788    int rc = SQLITE_OK;
000789    int bSeenBusy = 0;
000790  
000791  #ifdef SQLITE_ENABLE_API_ARMOR
000792    if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
000793  #endif
000794    sqlite3_mutex_enter(db->mutex);
000795    sqlite3BtreeEnterAll(db);
000796    for(i=0; rc==SQLITE_OK && i<db->nDb; i++){
000797      Btree *pBt = db->aDb[i].pBt;
000798      if( pBt && sqlite3BtreeIsInTrans(pBt) ){
000799        Pager *pPager = sqlite3BtreePager(pBt);
000800        rc = sqlite3PagerFlush(pPager);
000801        if( rc==SQLITE_BUSY ){
000802          bSeenBusy = 1;
000803          rc = SQLITE_OK;
000804        }
000805      }
000806    }
000807    sqlite3BtreeLeaveAll(db);
000808    sqlite3_mutex_leave(db->mutex);
000809    return ((rc==SQLITE_OK && bSeenBusy) ? SQLITE_BUSY : rc);
000810  }
000811  
000812  /*
000813  ** Configuration settings for an individual database connection
000814  */
000815  int sqlite3_db_config(sqlite3 *db, int op, ...){
000816    va_list ap;
000817    int rc;
000818    va_start(ap, op);
000819    switch( op ){
000820      case SQLITE_DBCONFIG_MAINDBNAME: {
000821        /* IMP: R-06824-28531 */
000822        /* IMP: R-36257-52125 */
000823        db->aDb[0].zDbSName = va_arg(ap,char*);
000824        rc = SQLITE_OK;
000825        break;
000826      }
000827      case SQLITE_DBCONFIG_LOOKASIDE: {
000828        void *pBuf = va_arg(ap, void*); /* IMP: R-26835-10964 */
000829        int sz = va_arg(ap, int);       /* IMP: R-47871-25994 */
000830        int cnt = va_arg(ap, int);      /* IMP: R-04460-53386 */
000831        rc = setupLookaside(db, pBuf, sz, cnt);
000832        break;
000833      }
000834      default: {
000835        static const struct {
000836          int op;      /* The opcode */
000837          u32 mask;    /* Mask of the bit in sqlite3.flags to set/clear */
000838        } aFlagOp[] = {
000839          { SQLITE_DBCONFIG_ENABLE_FKEY,           SQLITE_ForeignKeys    },
000840          { SQLITE_DBCONFIG_ENABLE_TRIGGER,        SQLITE_EnableTrigger  },
000841          { SQLITE_DBCONFIG_ENABLE_VIEW,           SQLITE_EnableView     },
000842          { SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER, SQLITE_Fts3Tokenizer  },
000843          { SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION, SQLITE_LoadExtension  },
000844          { SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE,      SQLITE_NoCkptOnClose  },
000845          { SQLITE_DBCONFIG_ENABLE_QPSG,           SQLITE_EnableQPSG     },
000846          { SQLITE_DBCONFIG_TRIGGER_EQP,           SQLITE_TriggerEQP     },
000847          { SQLITE_DBCONFIG_RESET_DATABASE,        SQLITE_ResetDatabase  },
000848          { SQLITE_DBCONFIG_DEFENSIVE,             SQLITE_Defensive      },
000849          { SQLITE_DBCONFIG_WRITABLE_SCHEMA,       SQLITE_WriteSchema|
000850                                                   SQLITE_NoSchemaError  },
000851          { SQLITE_DBCONFIG_LEGACY_ALTER_TABLE,    SQLITE_LegacyAlter    },
000852          { SQLITE_DBCONFIG_DQS_DDL,               SQLITE_DqsDDL         },
000853          { SQLITE_DBCONFIG_DQS_DML,               SQLITE_DqsDML         },
000854          { SQLITE_DBCONFIG_LEGACY_FILE_FORMAT,    SQLITE_LegacyFileFmt  },
000855        };
000856        unsigned int i;
000857        rc = SQLITE_ERROR; /* IMP: R-42790-23372 */
000858        for(i=0; i<ArraySize(aFlagOp); i++){
000859          if( aFlagOp[i].op==op ){
000860            int onoff = va_arg(ap, int);
000861            int *pRes = va_arg(ap, int*);
000862            u64 oldFlags = db->flags;
000863            if( onoff>0 ){
000864              db->flags |= aFlagOp[i].mask;
000865            }else if( onoff==0 ){
000866              db->flags &= ~(u64)aFlagOp[i].mask;
000867            }
000868            if( oldFlags!=db->flags ){
000869              sqlite3ExpirePreparedStatements(db, 0);
000870            }
000871            if( pRes ){
000872              *pRes = (db->flags & aFlagOp[i].mask)!=0;
000873            }
000874            rc = SQLITE_OK;
000875            break;
000876          }
000877        }
000878        break;
000879      }
000880    }
000881    va_end(ap);
000882    return rc;
000883  }
000884  
000885  /*
000886  ** This is the default collating function named "BINARY" which is always
000887  ** available.
000888  */
000889  static int binCollFunc(
000890    void *NotUsed,
000891    int nKey1, const void *pKey1,
000892    int nKey2, const void *pKey2
000893  ){
000894    int rc, n;
000895    UNUSED_PARAMETER(NotUsed);
000896    n = nKey1<nKey2 ? nKey1 : nKey2;
000897    /* EVIDENCE-OF: R-65033-28449 The built-in BINARY collation compares
000898    ** strings byte by byte using the memcmp() function from the standard C
000899    ** library. */
000900    assert( pKey1 && pKey2 );
000901    rc = memcmp(pKey1, pKey2, n);
000902    if( rc==0 ){
000903      rc = nKey1 - nKey2;
000904    }
000905    return rc;
000906  }
000907  
000908  /*
000909  ** This is the collating function named "RTRIM" which is always
000910  ** available.  Ignore trailing spaces.
000911  */
000912  static int rtrimCollFunc(
000913    void *pUser,
000914    int nKey1, const void *pKey1,
000915    int nKey2, const void *pKey2
000916  ){
000917    const u8 *pK1 = (const u8*)pKey1;
000918    const u8 *pK2 = (const u8*)pKey2;
000919    while( nKey1 && pK1[nKey1-1]==' ' ) nKey1--;
000920    while( nKey2 && pK2[nKey2-1]==' ' ) nKey2--;
000921    return binCollFunc(pUser, nKey1, pKey1, nKey2, pKey2);
000922  }
000923  
000924  /*
000925  ** Return true if CollSeq is the default built-in BINARY.
000926  */
000927  int sqlite3IsBinary(const CollSeq *p){
000928    assert( p==0 || p->xCmp!=binCollFunc || strcmp(p->zName,"BINARY")==0 );
000929    return p==0 || p->xCmp==binCollFunc;
000930  }
000931  
000932  /*
000933  ** Another built-in collating sequence: NOCASE. 
000934  **
000935  ** This collating sequence is intended to be used for "case independent
000936  ** comparison". SQLite's knowledge of upper and lower case equivalents
000937  ** extends only to the 26 characters used in the English language.
000938  **
000939  ** At the moment there is only a UTF-8 implementation.
000940  */
000941  static int nocaseCollatingFunc(
000942    void *NotUsed,
000943    int nKey1, const void *pKey1,
000944    int nKey2, const void *pKey2
000945  ){
000946    int r = sqlite3StrNICmp(
000947        (const char *)pKey1, (const char *)pKey2, (nKey1<nKey2)?nKey1:nKey2);
000948    UNUSED_PARAMETER(NotUsed);
000949    if( 0==r ){
000950      r = nKey1-nKey2;
000951    }
000952    return r;
000953  }
000954  
000955  /*
000956  ** Return the ROWID of the most recent insert
000957  */
000958  sqlite_int64 sqlite3_last_insert_rowid(sqlite3 *db){
000959  #ifdef SQLITE_ENABLE_API_ARMOR
000960    if( !sqlite3SafetyCheckOk(db) ){
000961      (void)SQLITE_MISUSE_BKPT;
000962      return 0;
000963    }
000964  #endif
000965    return db->lastRowid;
000966  }
000967  
000968  /*
000969  ** Set the value returned by the sqlite3_last_insert_rowid() API function.
000970  */
000971  void sqlite3_set_last_insert_rowid(sqlite3 *db, sqlite3_int64 iRowid){
000972  #ifdef SQLITE_ENABLE_API_ARMOR
000973    if( !sqlite3SafetyCheckOk(db) ){
000974      (void)SQLITE_MISUSE_BKPT;
000975      return;
000976    }
000977  #endif
000978    sqlite3_mutex_enter(db->mutex);
000979    db->lastRowid = iRowid;
000980    sqlite3_mutex_leave(db->mutex);
000981  }
000982  
000983  /*
000984  ** Return the number of changes in the most recent call to sqlite3_exec().
000985  */
000986  int sqlite3_changes(sqlite3 *db){
000987  #ifdef SQLITE_ENABLE_API_ARMOR
000988    if( !sqlite3SafetyCheckOk(db) ){
000989      (void)SQLITE_MISUSE_BKPT;
000990      return 0;
000991    }
000992  #endif
000993    return db->nChange;
000994  }
000995  
000996  /*
000997  ** Return the number of changes since the database handle was opened.
000998  */
000999  int sqlite3_total_changes(sqlite3 *db){
001000  #ifdef SQLITE_ENABLE_API_ARMOR
001001    if( !sqlite3SafetyCheckOk(db) ){
001002      (void)SQLITE_MISUSE_BKPT;
001003      return 0;
001004    }
001005  #endif
001006    return db->nTotalChange;
001007  }
001008  
001009  /*
001010  ** Close all open savepoints. This function only manipulates fields of the
001011  ** database handle object, it does not close any savepoints that may be open
001012  ** at the b-tree/pager level.
001013  */
001014  void sqlite3CloseSavepoints(sqlite3 *db){
001015    while( db->pSavepoint ){
001016      Savepoint *pTmp = db->pSavepoint;
001017      db->pSavepoint = pTmp->pNext;
001018      sqlite3DbFree(db, pTmp);
001019    }
001020    db->nSavepoint = 0;
001021    db->nStatement = 0;
001022    db->isTransactionSavepoint = 0;
001023  }
001024  
001025  /*
001026  ** Invoke the destructor function associated with FuncDef p, if any. Except,
001027  ** if this is not the last copy of the function, do not invoke it. Multiple
001028  ** copies of a single function are created when create_function() is called
001029  ** with SQLITE_ANY as the encoding.
001030  */
001031  static void functionDestroy(sqlite3 *db, FuncDef *p){
001032    FuncDestructor *pDestructor = p->u.pDestructor;
001033    if( pDestructor ){
001034      pDestructor->nRef--;
001035      if( pDestructor->nRef==0 ){
001036        pDestructor->xDestroy(pDestructor->pUserData);
001037        sqlite3DbFree(db, pDestructor);
001038      }
001039    }
001040  }
001041  
001042  /*
001043  ** Disconnect all sqlite3_vtab objects that belong to database connection
001044  ** db. This is called when db is being closed.
001045  */
001046  static void disconnectAllVtab(sqlite3 *db){
001047  #ifndef SQLITE_OMIT_VIRTUALTABLE
001048    int i;
001049    HashElem *p;
001050    sqlite3BtreeEnterAll(db);
001051    for(i=0; i<db->nDb; i++){
001052      Schema *pSchema = db->aDb[i].pSchema;
001053      if( pSchema ){
001054        for(p=sqliteHashFirst(&pSchema->tblHash); p; p=sqliteHashNext(p)){
001055          Table *pTab = (Table *)sqliteHashData(p);
001056          if( IsVirtual(pTab) ) sqlite3VtabDisconnect(db, pTab);
001057        }
001058      }
001059    }
001060    for(p=sqliteHashFirst(&db->aModule); p; p=sqliteHashNext(p)){
001061      Module *pMod = (Module *)sqliteHashData(p);
001062      if( pMod->pEpoTab ){
001063        sqlite3VtabDisconnect(db, pMod->pEpoTab);
001064      }
001065    }
001066    sqlite3VtabUnlockList(db);
001067    sqlite3BtreeLeaveAll(db);
001068  #else
001069    UNUSED_PARAMETER(db);
001070  #endif
001071  }
001072  
001073  /*
001074  ** Return TRUE if database connection db has unfinalized prepared
001075  ** statements or unfinished sqlite3_backup objects.  
001076  */
001077  static int connectionIsBusy(sqlite3 *db){
001078    int j;
001079    assert( sqlite3_mutex_held(db->mutex) );
001080    if( db->pVdbe ) return 1;
001081    for(j=0; j<db->nDb; j++){
001082      Btree *pBt = db->aDb[j].pBt;
001083      if( pBt && sqlite3BtreeIsInBackup(pBt) ) return 1;
001084    }
001085    return 0;
001086  }
001087  
001088  /*
001089  ** Close an existing SQLite database
001090  */
001091  static int sqlite3Close(sqlite3 *db, int forceZombie){
001092    if( !db ){
001093      /* EVIDENCE-OF: R-63257-11740 Calling sqlite3_close() or
001094      ** sqlite3_close_v2() with a NULL pointer argument is a harmless no-op. */
001095      return SQLITE_OK;
001096    }
001097    if( !sqlite3SafetyCheckSickOrOk(db) ){
001098      return SQLITE_MISUSE_BKPT;
001099    }
001100    sqlite3_mutex_enter(db->mutex);
001101    if( db->mTrace & SQLITE_TRACE_CLOSE ){
001102      db->xTrace(SQLITE_TRACE_CLOSE, db->pTraceArg, db, 0);
001103    }
001104  
001105    /* Force xDisconnect calls on all virtual tables */
001106    disconnectAllVtab(db);
001107  
001108    /* If a transaction is open, the disconnectAllVtab() call above
001109    ** will not have called the xDisconnect() method on any virtual
001110    ** tables in the db->aVTrans[] array. The following sqlite3VtabRollback()
001111    ** call will do so. We need to do this before the check for active
001112    ** SQL statements below, as the v-table implementation may be storing
001113    ** some prepared statements internally.
001114    */
001115    sqlite3VtabRollback(db);
001116  
001117    /* Legacy behavior (sqlite3_close() behavior) is to return
001118    ** SQLITE_BUSY if the connection can not be closed immediately.
001119    */
001120    if( !forceZombie && connectionIsBusy(db) ){
001121      sqlite3ErrorWithMsg(db, SQLITE_BUSY, "unable to close due to unfinalized "
001122         "statements or unfinished backups");
001123      sqlite3_mutex_leave(db->mutex);
001124      return SQLITE_BUSY;
001125    }
001126  
001127  #ifdef SQLITE_ENABLE_SQLLOG
001128    if( sqlite3GlobalConfig.xSqllog ){
001129      /* Closing the handle. Fourth parameter is passed the value 2. */
001130      sqlite3GlobalConfig.xSqllog(sqlite3GlobalConfig.pSqllogArg, db, 0, 2);
001131    }
001132  #endif
001133  
001134    /* Convert the connection into a zombie and then close it.
001135    */
001136    db->magic = SQLITE_MAGIC_ZOMBIE;
001137    sqlite3LeaveMutexAndCloseZombie(db);
001138    return SQLITE_OK;
001139  }
001140  
001141  /*
001142  ** Two variations on the public interface for closing a database
001143  ** connection. The sqlite3_close() version returns SQLITE_BUSY and
001144  ** leaves the connection option if there are unfinalized prepared
001145  ** statements or unfinished sqlite3_backups.  The sqlite3_close_v2()
001146  ** version forces the connection to become a zombie if there are
001147  ** unclosed resources, and arranges for deallocation when the last
001148  ** prepare statement or sqlite3_backup closes.
001149  */
001150  int sqlite3_close(sqlite3 *db){ return sqlite3Close(db,0); }
001151  int sqlite3_close_v2(sqlite3 *db){ return sqlite3Close(db,1); }
001152  
001153  
001154  /*
001155  ** Close the mutex on database connection db.
001156  **
001157  ** Furthermore, if database connection db is a zombie (meaning that there
001158  ** has been a prior call to sqlite3_close(db) or sqlite3_close_v2(db)) and
001159  ** every sqlite3_stmt has now been finalized and every sqlite3_backup has
001160  ** finished, then free all resources.
001161  */
001162  void sqlite3LeaveMutexAndCloseZombie(sqlite3 *db){
001163    HashElem *i;                    /* Hash table iterator */
001164    int j;
001165  
001166    /* If there are outstanding sqlite3_stmt or sqlite3_backup objects
001167    ** or if the connection has not yet been closed by sqlite3_close_v2(),
001168    ** then just leave the mutex and return.
001169    */
001170    if( db->magic!=SQLITE_MAGIC_ZOMBIE || connectionIsBusy(db) ){
001171      sqlite3_mutex_leave(db->mutex);
001172      return;
001173    }
001174  
001175    /* If we reach this point, it means that the database connection has
001176    ** closed all sqlite3_stmt and sqlite3_backup objects and has been
001177    ** passed to sqlite3_close (meaning that it is a zombie).  Therefore,
001178    ** go ahead and free all resources.
001179    */
001180  
001181    /* If a transaction is open, roll it back. This also ensures that if
001182    ** any database schemas have been modified by an uncommitted transaction
001183    ** they are reset. And that the required b-tree mutex is held to make
001184    ** the pager rollback and schema reset an atomic operation. */
001185    sqlite3RollbackAll(db, SQLITE_OK);
001186  
001187    /* Free any outstanding Savepoint structures. */
001188    sqlite3CloseSavepoints(db);
001189  
001190    /* Close all database connections */
001191    for(j=0; j<db->nDb; j++){
001192      struct Db *pDb = &db->aDb[j];
001193      if( pDb->pBt ){
001194        sqlite3BtreeClose(pDb->pBt);
001195        pDb->pBt = 0;
001196        if( j!=1 ){
001197          pDb->pSchema = 0;
001198        }
001199      }
001200    }
001201    /* Clear the TEMP schema separately and last */
001202    if( db->aDb[1].pSchema ){
001203      sqlite3SchemaClear(db->aDb[1].pSchema);
001204    }
001205    sqlite3VtabUnlockList(db);
001206  
001207    /* Free up the array of auxiliary databases */
001208    sqlite3CollapseDatabaseArray(db);
001209    assert( db->nDb<=2 );
001210    assert( db->aDb==db->aDbStatic );
001211  
001212    /* Tell the code in notify.c that the connection no longer holds any
001213    ** locks and does not require any further unlock-notify callbacks.
001214    */
001215    sqlite3ConnectionClosed(db);
001216  
001217    for(i=sqliteHashFirst(&db->aFunc); i; i=sqliteHashNext(i)){
001218      FuncDef *pNext, *p;
001219      p = sqliteHashData(i);
001220      do{
001221        functionDestroy(db, p);
001222        pNext = p->pNext;
001223        sqlite3DbFree(db, p);
001224        p = pNext;
001225      }while( p );
001226    }
001227    sqlite3HashClear(&db->aFunc);
001228    for(i=sqliteHashFirst(&db->aCollSeq); i; i=sqliteHashNext(i)){
001229      CollSeq *pColl = (CollSeq *)sqliteHashData(i);
001230      /* Invoke any destructors registered for collation sequence user data. */
001231      for(j=0; j<3; j++){
001232        if( pColl[j].xDel ){
001233          pColl[j].xDel(pColl[j].pUser);
001234        }
001235      }
001236      sqlite3DbFree(db, pColl);
001237    }
001238    sqlite3HashClear(&db->aCollSeq);
001239  #ifndef SQLITE_OMIT_VIRTUALTABLE
001240    for(i=sqliteHashFirst(&db->aModule); i; i=sqliteHashNext(i)){
001241      Module *pMod = (Module *)sqliteHashData(i);
001242      sqlite3VtabEponymousTableClear(db, pMod);
001243      sqlite3VtabModuleUnref(db, pMod);
001244    }
001245    sqlite3HashClear(&db->aModule);
001246  #endif
001247  
001248    sqlite3Error(db, SQLITE_OK); /* Deallocates any cached error strings. */
001249    sqlite3ValueFree(db->pErr);
001250    sqlite3CloseExtensions(db);
001251  #if SQLITE_USER_AUTHENTICATION
001252    sqlite3_free(db->auth.zAuthUser);
001253    sqlite3_free(db->auth.zAuthPW);
001254  #endif
001255  
001256    db->magic = SQLITE_MAGIC_ERROR;
001257  
001258    /* The temp-database schema is allocated differently from the other schema
001259    ** objects (using sqliteMalloc() directly, instead of sqlite3BtreeSchema()).
001260    ** So it needs to be freed here. Todo: Why not roll the temp schema into
001261    ** the same sqliteMalloc() as the one that allocates the database 
001262    ** structure?
001263    */
001264    sqlite3DbFree(db, db->aDb[1].pSchema);
001265    sqlite3_mutex_leave(db->mutex);
001266    db->magic = SQLITE_MAGIC_CLOSED;
001267    sqlite3_mutex_free(db->mutex);
001268    assert( sqlite3LookasideUsed(db,0)==0 );
001269    if( db->lookaside.bMalloced ){
001270      sqlite3_free(db->lookaside.pStart);
001271    }
001272    sqlite3_free(db);
001273  }
001274  
001275  /*
001276  ** Rollback all database files.  If tripCode is not SQLITE_OK, then
001277  ** any write cursors are invalidated ("tripped" - as in "tripping a circuit
001278  ** breaker") and made to return tripCode if there are any further
001279  ** attempts to use that cursor.  Read cursors remain open and valid
001280  ** but are "saved" in case the table pages are moved around.
001281  */
001282  void sqlite3RollbackAll(sqlite3 *db, int tripCode){
001283    int i;
001284    int inTrans = 0;
001285    int schemaChange;
001286    assert( sqlite3_mutex_held(db->mutex) );
001287    sqlite3BeginBenignMalloc();
001288  
001289    /* Obtain all b-tree mutexes before making any calls to BtreeRollback(). 
001290    ** This is important in case the transaction being rolled back has
001291    ** modified the database schema. If the b-tree mutexes are not taken
001292    ** here, then another shared-cache connection might sneak in between
001293    ** the database rollback and schema reset, which can cause false
001294    ** corruption reports in some cases.  */
001295    sqlite3BtreeEnterAll(db);
001296    schemaChange = (db->mDbFlags & DBFLAG_SchemaChange)!=0 && db->init.busy==0;
001297  
001298    for(i=0; i<db->nDb; i++){
001299      Btree *p = db->aDb[i].pBt;
001300      if( p ){
001301        if( sqlite3BtreeIsInTrans(p) ){
001302          inTrans = 1;
001303        }
001304        sqlite3BtreeRollback(p, tripCode, !schemaChange);
001305      }
001306    }
001307    sqlite3VtabRollback(db);
001308    sqlite3EndBenignMalloc();
001309  
001310    if( schemaChange ){
001311      sqlite3ExpirePreparedStatements(db, 0);
001312      sqlite3ResetAllSchemasOfConnection(db);
001313    }
001314    sqlite3BtreeLeaveAll(db);
001315  
001316    /* Any deferred constraint violations have now been resolved. */
001317    db->nDeferredCons = 0;
001318    db->nDeferredImmCons = 0;
001319    db->flags &= ~(u64)SQLITE_DeferFKs;
001320  
001321    /* If one has been configured, invoke the rollback-hook callback */
001322    if( db->xRollbackCallback && (inTrans || !db->autoCommit) ){
001323      db->xRollbackCallback(db->pRollbackArg);
001324    }
001325  }
001326  
001327  /*
001328  ** Return a static string containing the name corresponding to the error code
001329  ** specified in the argument.
001330  */
001331  #if defined(SQLITE_NEED_ERR_NAME)
001332  const char *sqlite3ErrName(int rc){
001333    const char *zName = 0;
001334    int i, origRc = rc;
001335    for(i=0; i<2 && zName==0; i++, rc &= 0xff){
001336      switch( rc ){
001337        case SQLITE_OK:                 zName = "SQLITE_OK";                break;
001338        case SQLITE_ERROR:              zName = "SQLITE_ERROR";             break;
001339        case SQLITE_ERROR_SNAPSHOT:     zName = "SQLITE_ERROR_SNAPSHOT";    break;
001340        case SQLITE_INTERNAL:           zName = "SQLITE_INTERNAL";          break;
001341        case SQLITE_PERM:               zName = "SQLITE_PERM";              break;
001342        case SQLITE_ABORT:              zName = "SQLITE_ABORT";             break;
001343        case SQLITE_ABORT_ROLLBACK:     zName = "SQLITE_ABORT_ROLLBACK";    break;
001344        case SQLITE_BUSY:               zName = "SQLITE_BUSY";              break;
001345        case SQLITE_BUSY_RECOVERY:      zName = "SQLITE_BUSY_RECOVERY";     break;
001346        case SQLITE_BUSY_SNAPSHOT:      zName = "SQLITE_BUSY_SNAPSHOT";     break;
001347        case SQLITE_LOCKED:             zName = "SQLITE_LOCKED";            break;
001348        case SQLITE_LOCKED_SHAREDCACHE: zName = "SQLITE_LOCKED_SHAREDCACHE";break;
001349        case SQLITE_NOMEM:              zName = "SQLITE_NOMEM";             break;
001350        case SQLITE_READONLY:           zName = "SQLITE_READONLY";          break;
001351        case SQLITE_READONLY_RECOVERY:  zName = "SQLITE_READONLY_RECOVERY"; break;
001352        case SQLITE_READONLY_CANTINIT:  zName = "SQLITE_READONLY_CANTINIT"; break;
001353        case SQLITE_READONLY_ROLLBACK:  zName = "SQLITE_READONLY_ROLLBACK"; break;
001354        case SQLITE_READONLY_DBMOVED:   zName = "SQLITE_READONLY_DBMOVED";  break;
001355        case SQLITE_READONLY_DIRECTORY: zName = "SQLITE_READONLY_DIRECTORY";break;
001356        case SQLITE_INTERRUPT:          zName = "SQLITE_INTERRUPT";         break;
001357        case SQLITE_IOERR:              zName = "SQLITE_IOERR";             break;
001358        case SQLITE_IOERR_READ:         zName = "SQLITE_IOERR_READ";        break;
001359        case SQLITE_IOERR_SHORT_READ:   zName = "SQLITE_IOERR_SHORT_READ";  break;
001360        case SQLITE_IOERR_WRITE:        zName = "SQLITE_IOERR_WRITE";       break;
001361        case SQLITE_IOERR_FSYNC:        zName = "SQLITE_IOERR_FSYNC";       break;
001362        case SQLITE_IOERR_DIR_FSYNC:    zName = "SQLITE_IOERR_DIR_FSYNC";   break;
001363        case SQLITE_IOERR_TRUNCATE:     zName = "SQLITE_IOERR_TRUNCATE";    break;
001364        case SQLITE_IOERR_FSTAT:        zName = "SQLITE_IOERR_FSTAT";       break;
001365        case SQLITE_IOERR_UNLOCK:       zName = "SQLITE_IOERR_UNLOCK";      break;
001366        case SQLITE_IOERR_RDLOCK:       zName = "SQLITE_IOERR_RDLOCK";      break;
001367        case SQLITE_IOERR_DELETE:       zName = "SQLITE_IOERR_DELETE";      break;
001368        case SQLITE_IOERR_NOMEM:        zName = "SQLITE_IOERR_NOMEM";       break;
001369        case SQLITE_IOERR_ACCESS:       zName = "SQLITE_IOERR_ACCESS";      break;
001370        case SQLITE_IOERR_CHECKRESERVEDLOCK:
001371                                  zName = "SQLITE_IOERR_CHECKRESERVEDLOCK"; break;
001372        case SQLITE_IOERR_LOCK:         zName = "SQLITE_IOERR_LOCK";        break;
001373        case SQLITE_IOERR_CLOSE:        zName = "SQLITE_IOERR_CLOSE";       break;
001374        case SQLITE_IOERR_DIR_CLOSE:    zName = "SQLITE_IOERR_DIR_CLOSE";   break;
001375        case SQLITE_IOERR_SHMOPEN:      zName = "SQLITE_IOERR_SHMOPEN";     break;
001376        case SQLITE_IOERR_SHMSIZE:      zName = "SQLITE_IOERR_SHMSIZE";     break;
001377        case SQLITE_IOERR_SHMLOCK:      zName = "SQLITE_IOERR_SHMLOCK";     break;
001378        case SQLITE_IOERR_SHMMAP:       zName = "SQLITE_IOERR_SHMMAP";      break;
001379        case SQLITE_IOERR_SEEK:         zName = "SQLITE_IOERR_SEEK";        break;
001380        case SQLITE_IOERR_DELETE_NOENT: zName = "SQLITE_IOERR_DELETE_NOENT";break;
001381        case SQLITE_IOERR_MMAP:         zName = "SQLITE_IOERR_MMAP";        break;
001382        case SQLITE_IOERR_GETTEMPPATH:  zName = "SQLITE_IOERR_GETTEMPPATH"; break;
001383        case SQLITE_IOERR_CONVPATH:     zName = "SQLITE_IOERR_CONVPATH";    break;
001384        case SQLITE_CORRUPT:            zName = "SQLITE_CORRUPT";           break;
001385        case SQLITE_CORRUPT_VTAB:       zName = "SQLITE_CORRUPT_VTAB";      break;
001386        case SQLITE_NOTFOUND:           zName = "SQLITE_NOTFOUND";          break;
001387        case SQLITE_FULL:               zName = "SQLITE_FULL";              break;
001388        case SQLITE_CANTOPEN:           zName = "SQLITE_CANTOPEN";          break;
001389        case SQLITE_CANTOPEN_NOTEMPDIR: zName = "SQLITE_CANTOPEN_NOTEMPDIR";break;
001390        case SQLITE_CANTOPEN_ISDIR:     zName = "SQLITE_CANTOPEN_ISDIR";    break;
001391        case SQLITE_CANTOPEN_FULLPATH:  zName = "SQLITE_CANTOPEN_FULLPATH"; break;
001392        case SQLITE_CANTOPEN_CONVPATH:  zName = "SQLITE_CANTOPEN_CONVPATH"; break;
001393        case SQLITE_CANTOPEN_SYMLINK:   zName = "SQLITE_CANTOPEN_SYMLINK";  break;
001394        case SQLITE_PROTOCOL:           zName = "SQLITE_PROTOCOL";          break;
001395        case SQLITE_EMPTY:              zName = "SQLITE_EMPTY";             break;
001396        case SQLITE_SCHEMA:             zName = "SQLITE_SCHEMA";            break;
001397        case SQLITE_TOOBIG:             zName = "SQLITE_TOOBIG";            break;
001398        case SQLITE_CONSTRAINT:         zName = "SQLITE_CONSTRAINT";        break;
001399        case SQLITE_CONSTRAINT_UNIQUE:  zName = "SQLITE_CONSTRAINT_UNIQUE"; break;
001400        case SQLITE_CONSTRAINT_TRIGGER: zName = "SQLITE_CONSTRAINT_TRIGGER";break;
001401        case SQLITE_CONSTRAINT_FOREIGNKEY:
001402                                  zName = "SQLITE_CONSTRAINT_FOREIGNKEY";   break;
001403        case SQLITE_CONSTRAINT_CHECK:   zName = "SQLITE_CONSTRAINT_CHECK";  break;
001404        case SQLITE_CONSTRAINT_PRIMARYKEY:
001405                                  zName = "SQLITE_CONSTRAINT_PRIMARYKEY";   break;
001406        case SQLITE_CONSTRAINT_NOTNULL: zName = "SQLITE_CONSTRAINT_NOTNULL";break;
001407        case SQLITE_CONSTRAINT_COMMITHOOK:
001408                                  zName = "SQLITE_CONSTRAINT_COMMITHOOK";   break;
001409        case SQLITE_CONSTRAINT_VTAB:    zName = "SQLITE_CONSTRAINT_VTAB";   break;
001410        case SQLITE_CONSTRAINT_FUNCTION:
001411                                  zName = "SQLITE_CONSTRAINT_FUNCTION";     break;
001412        case SQLITE_CONSTRAINT_ROWID:   zName = "SQLITE_CONSTRAINT_ROWID";  break;
001413        case SQLITE_MISMATCH:           zName = "SQLITE_MISMATCH";          break;
001414        case SQLITE_MISUSE:             zName = "SQLITE_MISUSE";            break;
001415        case SQLITE_NOLFS:              zName = "SQLITE_NOLFS";             break;
001416        case SQLITE_AUTH:               zName = "SQLITE_AUTH";              break;
001417        case SQLITE_FORMAT:             zName = "SQLITE_FORMAT";            break;
001418        case SQLITE_RANGE:              zName = "SQLITE_RANGE";             break;
001419        case SQLITE_NOTADB:             zName = "SQLITE_NOTADB";            break;
001420        case SQLITE_ROW:                zName = "SQLITE_ROW";               break;
001421        case SQLITE_NOTICE:             zName = "SQLITE_NOTICE";            break;
001422        case SQLITE_NOTICE_RECOVER_WAL: zName = "SQLITE_NOTICE_RECOVER_WAL";break;
001423        case SQLITE_NOTICE_RECOVER_ROLLBACK:
001424                                  zName = "SQLITE_NOTICE_RECOVER_ROLLBACK"; break;
001425        case SQLITE_WARNING:            zName = "SQLITE_WARNING";           break;
001426        case SQLITE_WARNING_AUTOINDEX:  zName = "SQLITE_WARNING_AUTOINDEX"; break;
001427        case SQLITE_DONE:               zName = "SQLITE_DONE";              break;
001428      }
001429    }
001430    if( zName==0 ){
001431      static char zBuf[50];
001432      sqlite3_snprintf(sizeof(zBuf), zBuf, "SQLITE_UNKNOWN(%d)", origRc);
001433      zName = zBuf;
001434    }
001435    return zName;
001436  }
001437  #endif
001438  
001439  /*
001440  ** Return a static string that describes the kind of error specified in the
001441  ** argument.
001442  */
001443  const char *sqlite3ErrStr(int rc){
001444    static const char* const aMsg[] = {
001445      /* SQLITE_OK          */ "not an error",
001446      /* SQLITE_ERROR       */ "SQL logic error",
001447      /* SQLITE_INTERNAL    */ 0,
001448      /* SQLITE_PERM        */ "access permission denied",
001449      /* SQLITE_ABORT       */ "query aborted",
001450      /* SQLITE_BUSY        */ "database is locked",
001451      /* SQLITE_LOCKED      */ "database table is locked",
001452      /* SQLITE_NOMEM       */ "out of memory",
001453      /* SQLITE_READONLY    */ "attempt to write a readonly database",
001454      /* SQLITE_INTERRUPT   */ "interrupted",
001455      /* SQLITE_IOERR       */ "disk I/O error",
001456      /* SQLITE_CORRUPT     */ "database disk image is malformed",
001457      /* SQLITE_NOTFOUND    */ "unknown operation",
001458      /* SQLITE_FULL        */ "database or disk is full",
001459      /* SQLITE_CANTOPEN    */ "unable to open database file",
001460      /* SQLITE_PROTOCOL    */ "locking protocol",
001461      /* SQLITE_EMPTY       */ 0,
001462      /* SQLITE_SCHEMA      */ "database schema has changed",
001463      /* SQLITE_TOOBIG      */ "string or blob too big",
001464      /* SQLITE_CONSTRAINT  */ "constraint failed",
001465      /* SQLITE_MISMATCH    */ "datatype mismatch",
001466      /* SQLITE_MISUSE      */ "bad parameter or other API misuse",
001467  #ifdef SQLITE_DISABLE_LFS
001468      /* SQLITE_NOLFS       */ "large file support is disabled",
001469  #else
001470      /* SQLITE_NOLFS       */ 0,
001471  #endif
001472      /* SQLITE_AUTH        */ "authorization denied",
001473      /* SQLITE_FORMAT      */ 0,
001474      /* SQLITE_RANGE       */ "column index out of range",
001475      /* SQLITE_NOTADB      */ "file is not a database",
001476      /* SQLITE_NOTICE      */ "notification message",
001477      /* SQLITE_WARNING     */ "warning message",
001478    };
001479    const char *zErr = "unknown error";
001480    switch( rc ){
001481      case SQLITE_ABORT_ROLLBACK: {
001482        zErr = "abort due to ROLLBACK";
001483        break;
001484      }
001485      case SQLITE_ROW: {
001486        zErr = "another row available";
001487        break;
001488      }
001489      case SQLITE_DONE: {
001490        zErr = "no more rows available";
001491        break;
001492      }
001493      default: {
001494        rc &= 0xff;
001495        if( ALWAYS(rc>=0) && rc<ArraySize(aMsg) && aMsg[rc]!=0 ){
001496          zErr = aMsg[rc];
001497        }
001498        break;
001499      }
001500    }
001501    return zErr;
001502  }
001503  
001504  /*
001505  ** This routine implements a busy callback that sleeps and tries
001506  ** again until a timeout value is reached.  The timeout value is
001507  ** an integer number of milliseconds passed in as the first
001508  ** argument.
001509  **
001510  ** Return non-zero to retry the lock.  Return zero to stop trying
001511  ** and cause SQLite to return SQLITE_BUSY.
001512  */
001513  static int sqliteDefaultBusyCallback(
001514    void *ptr,               /* Database connection */
001515    int count,               /* Number of times table has been busy */
001516    sqlite3_file *pFile      /* The file on which the lock occurred */
001517  ){
001518  #if SQLITE_OS_WIN || HAVE_USLEEP
001519    /* This case is for systems that have support for sleeping for fractions of
001520    ** a second.  Examples:  All windows systems, unix systems with usleep() */
001521    static const u8 delays[] =
001522       { 1, 2, 5, 10, 15, 20, 25, 25,  25,  50,  50, 100 };
001523    static const u8 totals[] =
001524       { 0, 1, 3,  8, 18, 33, 53, 78, 103, 128, 178, 228 };
001525  # define NDELAY ArraySize(delays)
001526    sqlite3 *db = (sqlite3 *)ptr;
001527    int tmout = db->busyTimeout;
001528    int delay, prior;
001529  
001530  #ifdef SQLITE_ENABLE_SETLK_TIMEOUT
001531    if( sqlite3OsFileControl(pFile,SQLITE_FCNTL_LOCK_TIMEOUT,&tmout)==SQLITE_OK ){
001532      if( count ){
001533        tmout = 0;
001534        sqlite3OsFileControl(pFile, SQLITE_FCNTL_LOCK_TIMEOUT, &tmout);
001535        return 0;
001536      }else{
001537        return 1;
001538      }
001539    }
001540  #else
001541    UNUSED_PARAMETER(pFile);
001542  #endif
001543    assert( count>=0 );
001544    if( count < NDELAY ){
001545      delay = delays[count];
001546      prior = totals[count];
001547    }else{
001548      delay = delays[NDELAY-1];
001549      prior = totals[NDELAY-1] + delay*(count-(NDELAY-1));
001550    }
001551    if( prior + delay > tmout ){
001552      delay = tmout - prior;
001553      if( delay<=0 ) return 0;
001554    }
001555    sqlite3OsSleep(db->pVfs, delay*1000);
001556    return 1;
001557  #else
001558    /* This case for unix systems that lack usleep() support.  Sleeping
001559    ** must be done in increments of whole seconds */
001560    sqlite3 *db = (sqlite3 *)ptr;
001561    int tmout = ((sqlite3 *)ptr)->busyTimeout;
001562    UNUSED_PARAMETER(pFile);
001563    if( (count+1)*1000 > tmout ){
001564      return 0;
001565    }
001566    sqlite3OsSleep(db->pVfs, 1000000);
001567    return 1;
001568  #endif
001569  }
001570  
001571  /*
001572  ** Invoke the given busy handler.
001573  **
001574  ** This routine is called when an operation failed to acquire a
001575  ** lock on VFS file pFile.
001576  **
001577  ** If this routine returns non-zero, the lock is retried.  If it
001578  ** returns 0, the operation aborts with an SQLITE_BUSY error.
001579  */
001580  int sqlite3InvokeBusyHandler(BusyHandler *p, sqlite3_file *pFile){
001581    int rc;
001582    if( p->xBusyHandler==0 || p->nBusy<0 ) return 0;
001583    if( p->bExtraFileArg ){
001584      /* Add an extra parameter with the pFile pointer to the end of the
001585      ** callback argument list */
001586      int (*xTra)(void*,int,sqlite3_file*);
001587      xTra = (int(*)(void*,int,sqlite3_file*))p->xBusyHandler;
001588      rc = xTra(p->pBusyArg, p->nBusy, pFile);
001589    }else{
001590      /* Legacy style busy handler callback */
001591      rc = p->xBusyHandler(p->pBusyArg, p->nBusy);
001592    }
001593    if( rc==0 ){
001594      p->nBusy = -1;
001595    }else{
001596      p->nBusy++;
001597    }
001598    return rc; 
001599  }
001600  
001601  /*
001602  ** This routine sets the busy callback for an Sqlite database to the
001603  ** given callback function with the given argument.
001604  */
001605  int sqlite3_busy_handler(
001606    sqlite3 *db,
001607    int (*xBusy)(void*,int),
001608    void *pArg
001609  ){
001610  #ifdef SQLITE_ENABLE_API_ARMOR
001611    if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
001612  #endif
001613    sqlite3_mutex_enter(db->mutex);
001614    db->busyHandler.xBusyHandler = xBusy;
001615    db->busyHandler.pBusyArg = pArg;
001616    db->busyHandler.nBusy = 0;
001617    db->busyHandler.bExtraFileArg = 0;
001618    db->busyTimeout = 0;
001619    sqlite3_mutex_leave(db->mutex);
001620    return SQLITE_OK;
001621  }
001622  
001623  #ifndef SQLITE_OMIT_PROGRESS_CALLBACK
001624  /*
001625  ** This routine sets the progress callback for an Sqlite database to the
001626  ** given callback function with the given argument. The progress callback will
001627  ** be invoked every nOps opcodes.
001628  */
001629  void sqlite3_progress_handler(
001630    sqlite3 *db, 
001631    int nOps,
001632    int (*xProgress)(void*), 
001633    void *pArg
001634  ){
001635  #ifdef SQLITE_ENABLE_API_ARMOR
001636    if( !sqlite3SafetyCheckOk(db) ){
001637      (void)SQLITE_MISUSE_BKPT;
001638      return;
001639    }
001640  #endif
001641    sqlite3_mutex_enter(db->mutex);
001642    if( nOps>0 ){
001643      db->xProgress = xProgress;
001644      db->nProgressOps = (unsigned)nOps;
001645      db->pProgressArg = pArg;
001646    }else{
001647      db->xProgress = 0;
001648      db->nProgressOps = 0;
001649      db->pProgressArg = 0;
001650    }
001651    sqlite3_mutex_leave(db->mutex);
001652  }
001653  #endif
001654  
001655  
001656  /*
001657  ** This routine installs a default busy handler that waits for the
001658  ** specified number of milliseconds before returning 0.
001659  */
001660  int sqlite3_busy_timeout(sqlite3 *db, int ms){
001661  #ifdef SQLITE_ENABLE_API_ARMOR
001662    if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
001663  #endif
001664    if( ms>0 ){
001665      sqlite3_busy_handler(db, (int(*)(void*,int))sqliteDefaultBusyCallback,
001666                               (void*)db);
001667      db->busyTimeout = ms;
001668      db->busyHandler.bExtraFileArg = 1;
001669    }else{
001670      sqlite3_busy_handler(db, 0, 0);
001671    }
001672    return SQLITE_OK;
001673  }
001674  
001675  /*
001676  ** Cause any pending operation to stop at its earliest opportunity.
001677  */
001678  void sqlite3_interrupt(sqlite3 *db){
001679  #ifdef SQLITE_ENABLE_API_ARMOR
001680    if( !sqlite3SafetyCheckOk(db) && (db==0 || db->magic!=SQLITE_MAGIC_ZOMBIE) ){
001681      (void)SQLITE_MISUSE_BKPT;
001682      return;
001683    }
001684  #endif
001685    db->u1.isInterrupted = 1;
001686  }
001687  
001688  
001689  /*
001690  ** This function is exactly the same as sqlite3_create_function(), except
001691  ** that it is designed to be called by internal code. The difference is
001692  ** that if a malloc() fails in sqlite3_create_function(), an error code
001693  ** is returned and the mallocFailed flag cleared. 
001694  */
001695  int sqlite3CreateFunc(
001696    sqlite3 *db,
001697    const char *zFunctionName,
001698    int nArg,
001699    int enc,
001700    void *pUserData,
001701    void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
001702    void (*xStep)(sqlite3_context*,int,sqlite3_value **),
001703    void (*xFinal)(sqlite3_context*),
001704    void (*xValue)(sqlite3_context*),
001705    void (*xInverse)(sqlite3_context*,int,sqlite3_value **),
001706    FuncDestructor *pDestructor
001707  ){
001708    FuncDef *p;
001709    int nName;
001710    int extraFlags;
001711  
001712    assert( sqlite3_mutex_held(db->mutex) );
001713    assert( xValue==0 || xSFunc==0 );
001714    if( zFunctionName==0                /* Must have a valid name */
001715     || (xSFunc!=0 && xFinal!=0)        /* Not both xSFunc and xFinal */
001716     || ((xFinal==0)!=(xStep==0))       /* Both or neither of xFinal and xStep */
001717     || ((xValue==0)!=(xInverse==0))    /* Both or neither of xValue, xInverse */
001718     || (nArg<-1 || nArg>SQLITE_MAX_FUNCTION_ARG)
001719     || (255<(nName = sqlite3Strlen30( zFunctionName)))
001720    ){
001721      return SQLITE_MISUSE_BKPT;
001722    }
001723  
001724    assert( SQLITE_FUNC_CONSTANT==SQLITE_DETERMINISTIC );
001725    assert( SQLITE_FUNC_DIRECT==SQLITE_DIRECTONLY );
001726    extraFlags = enc &  (SQLITE_DETERMINISTIC|SQLITE_DIRECTONLY|SQLITE_SUBTYPE);
001727    enc &= (SQLITE_FUNC_ENCMASK|SQLITE_ANY);
001728    
001729  #ifndef SQLITE_OMIT_UTF16
001730    /* If SQLITE_UTF16 is specified as the encoding type, transform this
001731    ** to one of SQLITE_UTF16LE or SQLITE_UTF16BE using the
001732    ** SQLITE_UTF16NATIVE macro. SQLITE_UTF16 is not used internally.
001733    **
001734    ** If SQLITE_ANY is specified, add three versions of the function
001735    ** to the hash table.
001736    */
001737    if( enc==SQLITE_UTF16 ){
001738      enc = SQLITE_UTF16NATIVE;
001739    }else if( enc==SQLITE_ANY ){
001740      int rc;
001741      rc = sqlite3CreateFunc(db, zFunctionName, nArg, SQLITE_UTF8|extraFlags,
001742           pUserData, xSFunc, xStep, xFinal, xValue, xInverse, pDestructor);
001743      if( rc==SQLITE_OK ){
001744        rc = sqlite3CreateFunc(db, zFunctionName, nArg, SQLITE_UTF16LE|extraFlags,
001745            pUserData, xSFunc, xStep, xFinal, xValue, xInverse, pDestructor);
001746      }
001747      if( rc!=SQLITE_OK ){
001748        return rc;
001749      }
001750      enc = SQLITE_UTF16BE;
001751    }
001752  #else
001753    enc = SQLITE_UTF8;
001754  #endif
001755    
001756    /* Check if an existing function is being overridden or deleted. If so,
001757    ** and there are active VMs, then return SQLITE_BUSY. If a function
001758    ** is being overridden/deleted but there are no active VMs, allow the
001759    ** operation to continue but invalidate all precompiled statements.
001760    */
001761    p = sqlite3FindFunction(db, zFunctionName, nArg, (u8)enc, 0);
001762    if( p && (p->funcFlags & SQLITE_FUNC_ENCMASK)==(u32)enc && p->nArg==nArg ){
001763      if( db->nVdbeActive ){
001764        sqlite3ErrorWithMsg(db, SQLITE_BUSY, 
001765          "unable to delete/modify user-function due to active statements");
001766        assert( !db->mallocFailed );
001767        return SQLITE_BUSY;
001768      }else{
001769        sqlite3ExpirePreparedStatements(db, 0);
001770      }
001771    }
001772  
001773    p = sqlite3FindFunction(db, zFunctionName, nArg, (u8)enc, 1);
001774    assert(p || db->mallocFailed);
001775    if( !p ){
001776      return SQLITE_NOMEM_BKPT;
001777    }
001778  
001779    /* If an older version of the function with a configured destructor is
001780    ** being replaced invoke the destructor function here. */
001781    functionDestroy(db, p);
001782  
001783    if( pDestructor ){
001784      pDestructor->nRef++;
001785    }
001786    p->u.pDestructor = pDestructor;
001787    p->funcFlags = (p->funcFlags & SQLITE_FUNC_ENCMASK) | extraFlags;
001788    testcase( p->funcFlags & SQLITE_DETERMINISTIC );
001789    testcase( p->funcFlags & SQLITE_DIRECTONLY );
001790    p->xSFunc = xSFunc ? xSFunc : xStep;
001791    p->xFinalize = xFinal;
001792    p->xValue = xValue;
001793    p->xInverse = xInverse;
001794    p->pUserData = pUserData;
001795    p->nArg = (u16)nArg;
001796    return SQLITE_OK;
001797  }
001798  
001799  /*
001800  ** Worker function used by utf-8 APIs that create new functions:
001801  **
001802  **    sqlite3_create_function()
001803  **    sqlite3_create_function_v2()
001804  **    sqlite3_create_window_function()
001805  */
001806  static int createFunctionApi(
001807    sqlite3 *db,
001808    const char *zFunc,
001809    int nArg,
001810    int enc,
001811    void *p,
001812    void (*xSFunc)(sqlite3_context*,int,sqlite3_value**),
001813    void (*xStep)(sqlite3_context*,int,sqlite3_value**),
001814    void (*xFinal)(sqlite3_context*),
001815    void (*xValue)(sqlite3_context*),
001816    void (*xInverse)(sqlite3_context*,int,sqlite3_value**),
001817    void(*xDestroy)(void*)
001818  ){
001819    int rc = SQLITE_ERROR;
001820    FuncDestructor *pArg = 0;
001821  
001822  #ifdef SQLITE_ENABLE_API_ARMOR
001823    if( !sqlite3SafetyCheckOk(db) ){
001824      return SQLITE_MISUSE_BKPT;
001825    }
001826  #endif
001827    sqlite3_mutex_enter(db->mutex);
001828    if( xDestroy ){
001829      pArg = (FuncDestructor *)sqlite3Malloc(sizeof(FuncDestructor));
001830      if( !pArg ){
001831        sqlite3OomFault(db);
001832        xDestroy(p);
001833        goto out;
001834      }
001835      pArg->nRef = 0;
001836      pArg->xDestroy = xDestroy;
001837      pArg->pUserData = p;
001838    }
001839    rc = sqlite3CreateFunc(db, zFunc, nArg, enc, p, 
001840        xSFunc, xStep, xFinal, xValue, xInverse, pArg
001841    );
001842    if( pArg && pArg->nRef==0 ){
001843      assert( rc!=SQLITE_OK );
001844      xDestroy(p);
001845      sqlite3_free(pArg);
001846    }
001847  
001848   out:
001849    rc = sqlite3ApiExit(db, rc);
001850    sqlite3_mutex_leave(db->mutex);
001851    return rc;
001852  }
001853  
001854  /*
001855  ** Create new user functions.
001856  */
001857  int sqlite3_create_function(
001858    sqlite3 *db,
001859    const char *zFunc,
001860    int nArg,
001861    int enc,
001862    void *p,
001863    void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
001864    void (*xStep)(sqlite3_context*,int,sqlite3_value **),
001865    void (*xFinal)(sqlite3_context*)
001866  ){
001867    return createFunctionApi(db, zFunc, nArg, enc, p, xSFunc, xStep,
001868                                      xFinal, 0, 0, 0);
001869  }
001870  int sqlite3_create_function_v2(
001871    sqlite3 *db,
001872    const char *zFunc,
001873    int nArg,
001874    int enc,
001875    void *p,
001876    void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
001877    void (*xStep)(sqlite3_context*,int,sqlite3_value **),
001878    void (*xFinal)(sqlite3_context*),
001879    void (*xDestroy)(void *)
001880  ){
001881    return createFunctionApi(db, zFunc, nArg, enc, p, xSFunc, xStep,
001882                                      xFinal, 0, 0, xDestroy);
001883  }
001884  int sqlite3_create_window_function(
001885    sqlite3 *db,
001886    const char *zFunc,
001887    int nArg,
001888    int enc,
001889    void *p,
001890    void (*xStep)(sqlite3_context*,int,sqlite3_value **),
001891    void (*xFinal)(sqlite3_context*),
001892    void (*xValue)(sqlite3_context*),
001893    void (*xInverse)(sqlite3_context*,int,sqlite3_value **),
001894    void (*xDestroy)(void *)
001895  ){
001896    return createFunctionApi(db, zFunc, nArg, enc, p, 0, xStep,
001897                                      xFinal, xValue, xInverse, xDestroy);
001898  }
001899  
001900  #ifndef SQLITE_OMIT_UTF16
001901  int sqlite3_create_function16(
001902    sqlite3 *db,
001903    const void *zFunctionName,
001904    int nArg,
001905    int eTextRep,
001906    void *p,
001907    void (*xSFunc)(sqlite3_context*,int,sqlite3_value**),
001908    void (*xStep)(sqlite3_context*,int,sqlite3_value**),
001909    void (*xFinal)(sqlite3_context*)
001910  ){
001911    int rc;
001912    char *zFunc8;
001913  
001914  #ifdef SQLITE_ENABLE_API_ARMOR
001915    if( !sqlite3SafetyCheckOk(db) || zFunctionName==0 ) return SQLITE_MISUSE_BKPT;
001916  #endif
001917    sqlite3_mutex_enter(db->mutex);
001918    assert( !db->mallocFailed );
001919    zFunc8 = sqlite3Utf16to8(db, zFunctionName, -1, SQLITE_UTF16NATIVE);
001920    rc = sqlite3CreateFunc(db, zFunc8, nArg, eTextRep, p, xSFunc,xStep,xFinal,0,0,0);
001921    sqlite3DbFree(db, zFunc8);
001922    rc = sqlite3ApiExit(db, rc);
001923    sqlite3_mutex_leave(db->mutex);
001924    return rc;
001925  }
001926  #endif
001927  
001928  
001929  /*
001930  ** The following is the implementation of an SQL function that always
001931  ** fails with an error message stating that the function is used in the
001932  ** wrong context.  The sqlite3_overload_function() API might construct
001933  ** SQL function that use this routine so that the functions will exist
001934  ** for name resolution but are actually overloaded by the xFindFunction
001935  ** method of virtual tables.
001936  */
001937  static void sqlite3InvalidFunction(
001938    sqlite3_context *context,  /* The function calling context */
001939    int NotUsed,               /* Number of arguments to the function */
001940    sqlite3_value **NotUsed2   /* Value of each argument */
001941  ){
001942    const char *zName = (const char*)sqlite3_user_data(context);
001943    char *zErr;
001944    UNUSED_PARAMETER2(NotUsed, NotUsed2);
001945    zErr = sqlite3_mprintf(
001946        "unable to use function %s in the requested context", zName);
001947    sqlite3_result_error(context, zErr, -1);
001948    sqlite3_free(zErr);
001949  }
001950  
001951  /*
001952  ** Declare that a function has been overloaded by a virtual table.
001953  **
001954  ** If the function already exists as a regular global function, then
001955  ** this routine is a no-op.  If the function does not exist, then create
001956  ** a new one that always throws a run-time error.  
001957  **
001958  ** When virtual tables intend to provide an overloaded function, they
001959  ** should call this routine to make sure the global function exists.
001960  ** A global function must exist in order for name resolution to work
001961  ** properly.
001962  */
001963  int sqlite3_overload_function(
001964    sqlite3 *db,
001965    const char *zName,
001966    int nArg
001967  ){
001968    int rc;
001969    char *zCopy;
001970  
001971  #ifdef SQLITE_ENABLE_API_ARMOR
001972    if( !sqlite3SafetyCheckOk(db) || zName==0 || nArg<-2 ){
001973      return SQLITE_MISUSE_BKPT;
001974    }
001975  #endif
001976    sqlite3_mutex_enter(db->mutex);
001977    rc = sqlite3FindFunction(db, zName, nArg, SQLITE_UTF8, 0)!=0;
001978    sqlite3_mutex_leave(db->mutex);
001979    if( rc ) return SQLITE_OK;
001980    zCopy = sqlite3_mprintf(zName);
001981    if( zCopy==0 ) return SQLITE_NOMEM;
001982    return sqlite3_create_function_v2(db, zName, nArg, SQLITE_UTF8,
001983                             zCopy, sqlite3InvalidFunction, 0, 0, sqlite3_free);
001984  }
001985  
001986  #ifndef SQLITE_OMIT_TRACE
001987  /*
001988  ** Register a trace function.  The pArg from the previously registered trace
001989  ** is returned.  
001990  **
001991  ** A NULL trace function means that no tracing is executes.  A non-NULL
001992  ** trace is a pointer to a function that is invoked at the start of each
001993  ** SQL statement.
001994  */
001995  #ifndef SQLITE_OMIT_DEPRECATED
001996  void *sqlite3_trace(sqlite3 *db, void(*xTrace)(void*,const char*), void *pArg){
001997    void *pOld;
001998  
001999  #ifdef SQLITE_ENABLE_API_ARMOR
002000    if( !sqlite3SafetyCheckOk(db) ){
002001      (void)SQLITE_MISUSE_BKPT;
002002      return 0;
002003    }
002004  #endif
002005    sqlite3_mutex_enter(db->mutex);
002006    pOld = db->pTraceArg;
002007    db->mTrace = xTrace ? SQLITE_TRACE_LEGACY : 0;
002008    db->xTrace = (int(*)(u32,void*,void*,void*))xTrace;
002009    db->pTraceArg = pArg;
002010    sqlite3_mutex_leave(db->mutex);
002011    return pOld;
002012  }
002013  #endif /* SQLITE_OMIT_DEPRECATED */
002014  
002015  /* Register a trace callback using the version-2 interface.
002016  */
002017  int sqlite3_trace_v2(
002018    sqlite3 *db,                               /* Trace this connection */
002019    unsigned mTrace,                           /* Mask of events to be traced */
002020    int(*xTrace)(unsigned,void*,void*,void*),  /* Callback to invoke */
002021    void *pArg                                 /* Context */
002022  ){
002023  #ifdef SQLITE_ENABLE_API_ARMOR
002024    if( !sqlite3SafetyCheckOk(db) ){
002025      return SQLITE_MISUSE_BKPT;
002026    }
002027  #endif
002028    sqlite3_mutex_enter(db->mutex);
002029    if( mTrace==0 ) xTrace = 0;
002030    if( xTrace==0 ) mTrace = 0;
002031    db->mTrace = mTrace;
002032    db->xTrace = xTrace;
002033    db->pTraceArg = pArg;
002034    sqlite3_mutex_leave(db->mutex);
002035    return SQLITE_OK;
002036  }
002037  
002038  #ifndef SQLITE_OMIT_DEPRECATED
002039  /*
002040  ** Register a profile function.  The pArg from the previously registered 
002041  ** profile function is returned.  
002042  **
002043  ** A NULL profile function means that no profiling is executes.  A non-NULL
002044  ** profile is a pointer to a function that is invoked at the conclusion of
002045  ** each SQL statement that is run.
002046  */
002047  void *sqlite3_profile(
002048    sqlite3 *db,
002049    void (*xProfile)(void*,const char*,sqlite_uint64),
002050    void *pArg
002051  ){
002052    void *pOld;
002053  
002054  #ifdef SQLITE_ENABLE_API_ARMOR
002055    if( !sqlite3SafetyCheckOk(db) ){
002056      (void)SQLITE_MISUSE_BKPT;
002057      return 0;
002058    }
002059  #endif
002060    sqlite3_mutex_enter(db->mutex);
002061    pOld = db->pProfileArg;
002062    db->xProfile = xProfile;
002063    db->pProfileArg = pArg;
002064    db->mTrace &= SQLITE_TRACE_NONLEGACY_MASK;
002065    if( db->xProfile ) db->mTrace |= SQLITE_TRACE_XPROFILE;
002066    sqlite3_mutex_leave(db->mutex);
002067    return pOld;
002068  }
002069  #endif /* SQLITE_OMIT_DEPRECATED */
002070  #endif /* SQLITE_OMIT_TRACE */
002071  
002072  /*
002073  ** Register a function to be invoked when a transaction commits.
002074  ** If the invoked function returns non-zero, then the commit becomes a
002075  ** rollback.
002076  */
002077  void *sqlite3_commit_hook(
002078    sqlite3 *db,              /* Attach the hook to this database */
002079    int (*xCallback)(void*),  /* Function to invoke on each commit */
002080    void *pArg                /* Argument to the function */
002081  ){
002082    void *pOld;
002083  
002084  #ifdef SQLITE_ENABLE_API_ARMOR
002085    if( !sqlite3SafetyCheckOk(db) ){
002086      (void)SQLITE_MISUSE_BKPT;
002087      return 0;
002088    }
002089  #endif
002090    sqlite3_mutex_enter(db->mutex);
002091    pOld = db->pCommitArg;
002092    db->xCommitCallback = xCallback;
002093    db->pCommitArg = pArg;
002094    sqlite3_mutex_leave(db->mutex);
002095    return pOld;
002096  }
002097  
002098  /*
002099  ** Register a callback to be invoked each time a row is updated,
002100  ** inserted or deleted using this database connection.
002101  */
002102  void *sqlite3_update_hook(
002103    sqlite3 *db,              /* Attach the hook to this database */
002104    void (*xCallback)(void*,int,char const *,char const *,sqlite_int64),
002105    void *pArg                /* Argument to the function */
002106  ){
002107    void *pRet;
002108  
002109  #ifdef SQLITE_ENABLE_API_ARMOR
002110    if( !sqlite3SafetyCheckOk(db) ){
002111      (void)SQLITE_MISUSE_BKPT;
002112      return 0;
002113    }
002114  #endif
002115    sqlite3_mutex_enter(db->mutex);
002116    pRet = db->pUpdateArg;
002117    db->xUpdateCallback = xCallback;
002118    db->pUpdateArg = pArg;
002119    sqlite3_mutex_leave(db->mutex);
002120    return pRet;
002121  }
002122  
002123  /*
002124  ** Register a callback to be invoked each time a transaction is rolled
002125  ** back by this database connection.
002126  */
002127  void *sqlite3_rollback_hook(
002128    sqlite3 *db,              /* Attach the hook to this database */
002129    void (*xCallback)(void*), /* Callback function */
002130    void *pArg                /* Argument to the function */
002131  ){
002132    void *pRet;
002133  
002134  #ifdef SQLITE_ENABLE_API_ARMOR
002135    if( !sqlite3SafetyCheckOk(db) ){
002136      (void)SQLITE_MISUSE_BKPT;
002137      return 0;
002138    }
002139  #endif
002140    sqlite3_mutex_enter(db->mutex);
002141    pRet = db->pRollbackArg;
002142    db->xRollbackCallback = xCallback;
002143    db->pRollbackArg = pArg;
002144    sqlite3_mutex_leave(db->mutex);
002145    return pRet;
002146  }
002147  
002148  #ifdef SQLITE_ENABLE_PREUPDATE_HOOK
002149  /*
002150  ** Register a callback to be invoked each time a row is updated,
002151  ** inserted or deleted using this database connection.
002152  */
002153  void *sqlite3_preupdate_hook(
002154    sqlite3 *db,              /* Attach the hook to this database */
002155    void(*xCallback)(         /* Callback function */
002156      void*,sqlite3*,int,char const*,char const*,sqlite3_int64,sqlite3_int64),
002157    void *pArg                /* First callback argument */
002158  ){
002159    void *pRet;
002160    sqlite3_mutex_enter(db->mutex);
002161    pRet = db->pPreUpdateArg;
002162    db->xPreUpdateCallback = xCallback;
002163    db->pPreUpdateArg = pArg;
002164    sqlite3_mutex_leave(db->mutex);
002165    return pRet;
002166  }
002167  #endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
002168  
002169  #ifndef SQLITE_OMIT_WAL
002170  /*
002171  ** The sqlite3_wal_hook() callback registered by sqlite3_wal_autocheckpoint().
002172  ** Invoke sqlite3_wal_checkpoint if the number of frames in the log file
002173  ** is greater than sqlite3.pWalArg cast to an integer (the value configured by
002174  ** wal_autocheckpoint()).
002175  */ 
002176  int sqlite3WalDefaultHook(
002177    void *pClientData,     /* Argument */
002178    sqlite3 *db,           /* Connection */
002179    const char *zDb,       /* Database */
002180    int nFrame             /* Size of WAL */
002181  ){
002182    if( nFrame>=SQLITE_PTR_TO_INT(pClientData) ){
002183      sqlite3BeginBenignMalloc();
002184      sqlite3_wal_checkpoint(db, zDb);
002185      sqlite3EndBenignMalloc();
002186    }
002187    return SQLITE_OK;
002188  }
002189  #endif /* SQLITE_OMIT_WAL */
002190  
002191  /*
002192  ** Configure an sqlite3_wal_hook() callback to automatically checkpoint
002193  ** a database after committing a transaction if there are nFrame or
002194  ** more frames in the log file. Passing zero or a negative value as the
002195  ** nFrame parameter disables automatic checkpoints entirely.
002196  **
002197  ** The callback registered by this function replaces any existing callback
002198  ** registered using sqlite3_wal_hook(). Likewise, registering a callback
002199  ** using sqlite3_wal_hook() disables the automatic checkpoint mechanism
002200  ** configured by this function.
002201  */
002202  int sqlite3_wal_autocheckpoint(sqlite3 *db, int nFrame){
002203  #ifdef SQLITE_OMIT_WAL
002204    UNUSED_PARAMETER(db);
002205    UNUSED_PARAMETER(nFrame);
002206  #else
002207  #ifdef SQLITE_ENABLE_API_ARMOR
002208    if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
002209  #endif
002210    if( nFrame>0 ){
002211      sqlite3_wal_hook(db, sqlite3WalDefaultHook, SQLITE_INT_TO_PTR(nFrame));
002212    }else{
002213      sqlite3_wal_hook(db, 0, 0);
002214    }
002215  #endif
002216    return SQLITE_OK;
002217  }
002218  
002219  /*
002220  ** Register a callback to be invoked each time a transaction is written
002221  ** into the write-ahead-log by this database connection.
002222  */
002223  void *sqlite3_wal_hook(
002224    sqlite3 *db,                    /* Attach the hook to this db handle */
002225    int(*xCallback)(void *, sqlite3*, const char*, int),
002226    void *pArg                      /* First argument passed to xCallback() */
002227  ){
002228  #ifndef SQLITE_OMIT_WAL
002229    void *pRet;
002230  #ifdef SQLITE_ENABLE_API_ARMOR
002231    if( !sqlite3SafetyCheckOk(db) ){
002232      (void)SQLITE_MISUSE_BKPT;
002233      return 0;
002234    }
002235  #endif
002236    sqlite3_mutex_enter(db->mutex);
002237    pRet = db->pWalArg;
002238    db->xWalCallback = xCallback;
002239    db->pWalArg = pArg;
002240    sqlite3_mutex_leave(db->mutex);
002241    return pRet;
002242  #else
002243    return 0;
002244  #endif
002245  }
002246  
002247  /*
002248  ** Checkpoint database zDb.
002249  */
002250  int sqlite3_wal_checkpoint_v2(
002251    sqlite3 *db,                    /* Database handle */
002252    const char *zDb,                /* Name of attached database (or NULL) */
002253    int eMode,                      /* SQLITE_CHECKPOINT_* value */
002254    int *pnLog,                     /* OUT: Size of WAL log in frames */
002255    int *pnCkpt                     /* OUT: Total number of frames checkpointed */
002256  ){
002257  #ifdef SQLITE_OMIT_WAL
002258    return SQLITE_OK;
002259  #else
002260    int rc;                         /* Return code */
002261    int iDb = SQLITE_MAX_ATTACHED;  /* sqlite3.aDb[] index of db to checkpoint */
002262  
002263  #ifdef SQLITE_ENABLE_API_ARMOR
002264    if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
002265  #endif
002266  
002267    /* Initialize the output variables to -1 in case an error occurs. */
002268    if( pnLog ) *pnLog = -1;
002269    if( pnCkpt ) *pnCkpt = -1;
002270  
002271    assert( SQLITE_CHECKPOINT_PASSIVE==0 );
002272    assert( SQLITE_CHECKPOINT_FULL==1 );
002273    assert( SQLITE_CHECKPOINT_RESTART==2 );
002274    assert( SQLITE_CHECKPOINT_TRUNCATE==3 );
002275    if( eMode<SQLITE_CHECKPOINT_PASSIVE || eMode>SQLITE_CHECKPOINT_TRUNCATE ){
002276      /* EVIDENCE-OF: R-03996-12088 The M parameter must be a valid checkpoint
002277      ** mode: */
002278      return SQLITE_MISUSE;
002279    }
002280  
002281    sqlite3_mutex_enter(db->mutex);
002282    if( zDb && zDb[0] ){
002283      iDb = sqlite3FindDbName(db, zDb);
002284    }
002285    if( iDb<0 ){
002286      rc = SQLITE_ERROR;
002287      sqlite3ErrorWithMsg(db, SQLITE_ERROR, "unknown database: %s", zDb);
002288    }else{
002289      db->busyHandler.nBusy = 0;
002290      rc = sqlite3Checkpoint(db, iDb, eMode, pnLog, pnCkpt);
002291      sqlite3Error(db, rc);
002292    }
002293    rc = sqlite3ApiExit(db, rc);
002294  
002295    /* If there are no active statements, clear the interrupt flag at this
002296    ** point.  */
002297    if( db->nVdbeActive==0 ){
002298      db->u1.isInterrupted = 0;
002299    }
002300  
002301    sqlite3_mutex_leave(db->mutex);
002302    return rc;
002303  #endif
002304  }
002305  
002306  
002307  /*
002308  ** Checkpoint database zDb. If zDb is NULL, or if the buffer zDb points
002309  ** to contains a zero-length string, all attached databases are 
002310  ** checkpointed.
002311  */
002312  int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb){
002313    /* EVIDENCE-OF: R-41613-20553 The sqlite3_wal_checkpoint(D,X) is equivalent to
002314    ** sqlite3_wal_checkpoint_v2(D,X,SQLITE_CHECKPOINT_PASSIVE,0,0). */
002315    return sqlite3_wal_checkpoint_v2(db,zDb,SQLITE_CHECKPOINT_PASSIVE,0,0);
002316  }
002317  
002318  #ifndef SQLITE_OMIT_WAL
002319  /*
002320  ** Run a checkpoint on database iDb. This is a no-op if database iDb is
002321  ** not currently open in WAL mode.
002322  **
002323  ** If a transaction is open on the database being checkpointed, this 
002324  ** function returns SQLITE_LOCKED and a checkpoint is not attempted. If 
002325  ** an error occurs while running the checkpoint, an SQLite error code is 
002326  ** returned (i.e. SQLITE_IOERR). Otherwise, SQLITE_OK.
002327  **
002328  ** The mutex on database handle db should be held by the caller. The mutex
002329  ** associated with the specific b-tree being checkpointed is taken by
002330  ** this function while the checkpoint is running.
002331  **
002332  ** If iDb is passed SQLITE_MAX_ATTACHED, then all attached databases are
002333  ** checkpointed. If an error is encountered it is returned immediately -
002334  ** no attempt is made to checkpoint any remaining databases.
002335  **
002336  ** Parameter eMode is one of SQLITE_CHECKPOINT_PASSIVE, FULL, RESTART
002337  ** or TRUNCATE.
002338  */
002339  int sqlite3Checkpoint(sqlite3 *db, int iDb, int eMode, int *pnLog, int *pnCkpt){
002340    int rc = SQLITE_OK;             /* Return code */
002341    int i;                          /* Used to iterate through attached dbs */
002342    int bBusy = 0;                  /* True if SQLITE_BUSY has been encountered */
002343  
002344    assert( sqlite3_mutex_held(db->mutex) );
002345    assert( !pnLog || *pnLog==-1 );
002346    assert( !pnCkpt || *pnCkpt==-1 );
002347  
002348    for(i=0; i<db->nDb && rc==SQLITE_OK; i++){
002349      if( i==iDb || iDb==SQLITE_MAX_ATTACHED ){
002350        rc = sqlite3BtreeCheckpoint(db->aDb[i].pBt, eMode, pnLog, pnCkpt);
002351        pnLog = 0;
002352        pnCkpt = 0;
002353        if( rc==SQLITE_BUSY ){
002354          bBusy = 1;
002355          rc = SQLITE_OK;
002356        }
002357      }
002358    }
002359  
002360    return (rc==SQLITE_OK && bBusy) ? SQLITE_BUSY : rc;
002361  }
002362  #endif /* SQLITE_OMIT_WAL */
002363  
002364  /*
002365  ** This function returns true if main-memory should be used instead of
002366  ** a temporary file for transient pager files and statement journals.
002367  ** The value returned depends on the value of db->temp_store (runtime
002368  ** parameter) and the compile time value of SQLITE_TEMP_STORE. The
002369  ** following table describes the relationship between these two values
002370  ** and this functions return value.
002371  **
002372  **   SQLITE_TEMP_STORE     db->temp_store     Location of temporary database
002373  **   -----------------     --------------     ------------------------------
002374  **   0                     any                file      (return 0)
002375  **   1                     1                  file      (return 0)
002376  **   1                     2                  memory    (return 1)
002377  **   1                     0                  file      (return 0)
002378  **   2                     1                  file      (return 0)
002379  **   2                     2                  memory    (return 1)
002380  **   2                     0                  memory    (return 1)
002381  **   3                     any                memory    (return 1)
002382  */
002383  int sqlite3TempInMemory(const sqlite3 *db){
002384  #if SQLITE_TEMP_STORE==1
002385    return ( db->temp_store==2 );
002386  #endif
002387  #if SQLITE_TEMP_STORE==2
002388    return ( db->temp_store!=1 );
002389  #endif
002390  #if SQLITE_TEMP_STORE==3
002391    UNUSED_PARAMETER(db);
002392    return 1;
002393  #endif
002394  #if SQLITE_TEMP_STORE<1 || SQLITE_TEMP_STORE>3
002395    UNUSED_PARAMETER(db);
002396    return 0;
002397  #endif
002398  }
002399  
002400  /*
002401  ** Return UTF-8 encoded English language explanation of the most recent
002402  ** error.
002403  */
002404  const char *sqlite3_errmsg(sqlite3 *db){
002405    const char *z;
002406    if( !db ){
002407      return sqlite3ErrStr(SQLITE_NOMEM_BKPT);
002408    }
002409    if( !sqlite3SafetyCheckSickOrOk(db) ){
002410      return sqlite3ErrStr(SQLITE_MISUSE_BKPT);
002411    }
002412    sqlite3_mutex_enter(db->mutex);
002413    if( db->mallocFailed ){
002414      z = sqlite3ErrStr(SQLITE_NOMEM_BKPT);
002415    }else{
002416      testcase( db->pErr==0 );
002417      z = db->errCode ? (char*)sqlite3_value_text(db->pErr) : 0;
002418      assert( !db->mallocFailed );
002419      if( z==0 ){
002420        z = sqlite3ErrStr(db->errCode);
002421      }
002422    }
002423    sqlite3_mutex_leave(db->mutex);
002424    return z;
002425  }
002426  
002427  #ifndef SQLITE_OMIT_UTF16
002428  /*
002429  ** Return UTF-16 encoded English language explanation of the most recent
002430  ** error.
002431  */
002432  const void *sqlite3_errmsg16(sqlite3 *db){
002433    static const u16 outOfMem[] = {
002434      'o', 'u', 't', ' ', 'o', 'f', ' ', 'm', 'e', 'm', 'o', 'r', 'y', 0
002435    };
002436    static const u16 misuse[] = {
002437      'b', 'a', 'd', ' ', 'p', 'a', 'r', 'a', 'm', 'e', 't', 'e', 'r', ' ',
002438      'o', 'r', ' ', 'o', 't', 'h', 'e', 'r', ' ', 'A', 'P', 'I', ' ',
002439      'm', 'i', 's', 'u', 's', 'e', 0
002440    };
002441  
002442    const void *z;
002443    if( !db ){
002444      return (void *)outOfMem;
002445    }
002446    if( !sqlite3SafetyCheckSickOrOk(db) ){
002447      return (void *)misuse;
002448    }
002449    sqlite3_mutex_enter(db->mutex);
002450    if( db->mallocFailed ){
002451      z = (void *)outOfMem;
002452    }else{
002453      z = sqlite3_value_text16(db->pErr);
002454      if( z==0 ){
002455        sqlite3ErrorWithMsg(db, db->errCode, sqlite3ErrStr(db->errCode));
002456        z = sqlite3_value_text16(db->pErr);
002457      }
002458      /* A malloc() may have failed within the call to sqlite3_value_text16()
002459      ** above. If this is the case, then the db->mallocFailed flag needs to
002460      ** be cleared before returning. Do this directly, instead of via
002461      ** sqlite3ApiExit(), to avoid setting the database handle error message.
002462      */
002463      sqlite3OomClear(db);
002464    }
002465    sqlite3_mutex_leave(db->mutex);
002466    return z;
002467  }
002468  #endif /* SQLITE_OMIT_UTF16 */
002469  
002470  /*
002471  ** Return the most recent error code generated by an SQLite routine. If NULL is
002472  ** passed to this function, we assume a malloc() failed during sqlite3_open().
002473  */
002474  int sqlite3_errcode(sqlite3 *db){
002475    if( db && !sqlite3SafetyCheckSickOrOk(db) ){
002476      return SQLITE_MISUSE_BKPT;
002477    }
002478    if( !db || db->mallocFailed ){
002479      return SQLITE_NOMEM_BKPT;
002480    }
002481    return db->errCode & db->errMask;
002482  }
002483  int sqlite3_extended_errcode(sqlite3 *db){
002484    if( db && !sqlite3SafetyCheckSickOrOk(db) ){
002485      return SQLITE_MISUSE_BKPT;
002486    }
002487    if( !db || db->mallocFailed ){
002488      return SQLITE_NOMEM_BKPT;
002489    }
002490    return db->errCode;
002491  }
002492  int sqlite3_system_errno(sqlite3 *db){
002493    return db ? db->iSysErrno : 0;
002494  }  
002495  
002496  /*
002497  ** Return a string that describes the kind of error specified in the
002498  ** argument.  For now, this simply calls the internal sqlite3ErrStr()
002499  ** function.
002500  */
002501  const char *sqlite3_errstr(int rc){
002502    return sqlite3ErrStr(rc);
002503  }
002504  
002505  /*
002506  ** Create a new collating function for database "db".  The name is zName
002507  ** and the encoding is enc.
002508  */
002509  static int createCollation(
002510    sqlite3* db,
002511    const char *zName, 
002512    u8 enc,
002513    void* pCtx,
002514    int(*xCompare)(void*,int,const void*,int,const void*),
002515    void(*xDel)(void*)
002516  ){
002517    CollSeq *pColl;
002518    int enc2;
002519    
002520    assert( sqlite3_mutex_held(db->mutex) );
002521  
002522    /* If SQLITE_UTF16 is specified as the encoding type, transform this
002523    ** to one of SQLITE_UTF16LE or SQLITE_UTF16BE using the
002524    ** SQLITE_UTF16NATIVE macro. SQLITE_UTF16 is not used internally.
002525    */
002526    enc2 = enc;
002527    testcase( enc2==SQLITE_UTF16 );
002528    testcase( enc2==SQLITE_UTF16_ALIGNED );
002529    if( enc2==SQLITE_UTF16 || enc2==SQLITE_UTF16_ALIGNED ){
002530      enc2 = SQLITE_UTF16NATIVE;
002531    }
002532    if( enc2<SQLITE_UTF8 || enc2>SQLITE_UTF16BE ){
002533      return SQLITE_MISUSE_BKPT;
002534    }
002535  
002536    /* Check if this call is removing or replacing an existing collation 
002537    ** sequence. If so, and there are active VMs, return busy. If there
002538    ** are no active VMs, invalidate any pre-compiled statements.
002539    */
002540    pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, 0);
002541    if( pColl && pColl->xCmp ){
002542      if( db->nVdbeActive ){
002543        sqlite3ErrorWithMsg(db, SQLITE_BUSY, 
002544          "unable to delete/modify collation sequence due to active statements");
002545        return SQLITE_BUSY;
002546      }
002547      sqlite3ExpirePreparedStatements(db, 0);
002548  
002549      /* If collation sequence pColl was created directly by a call to
002550      ** sqlite3_create_collation, and not generated by synthCollSeq(),
002551      ** then any copies made by synthCollSeq() need to be invalidated.
002552      ** Also, collation destructor - CollSeq.xDel() - function may need
002553      ** to be called.
002554      */ 
002555      if( (pColl->enc & ~SQLITE_UTF16_ALIGNED)==enc2 ){
002556        CollSeq *aColl = sqlite3HashFind(&db->aCollSeq, zName);
002557        int j;
002558        for(j=0; j<3; j++){
002559          CollSeq *p = &aColl[j];
002560          if( p->enc==pColl->enc ){
002561            if( p->xDel ){
002562              p->xDel(p->pUser);
002563            }
002564            p->xCmp = 0;
002565          }
002566        }
002567      }
002568    }
002569  
002570    pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, 1);
002571    if( pColl==0 ) return SQLITE_NOMEM_BKPT;
002572    pColl->xCmp = xCompare;
002573    pColl->pUser = pCtx;
002574    pColl->xDel = xDel;
002575    pColl->enc = (u8)(enc2 | (enc & SQLITE_UTF16_ALIGNED));
002576    sqlite3Error(db, SQLITE_OK);
002577    return SQLITE_OK;
002578  }
002579  
002580  
002581  /*
002582  ** This array defines hard upper bounds on limit values.  The
002583  ** initializer must be kept in sync with the SQLITE_LIMIT_*
002584  ** #defines in sqlite3.h.
002585  */
002586  static const int aHardLimit[] = {
002587    SQLITE_MAX_LENGTH,
002588    SQLITE_MAX_SQL_LENGTH,
002589    SQLITE_MAX_COLUMN,
002590    SQLITE_MAX_EXPR_DEPTH,
002591    SQLITE_MAX_COMPOUND_SELECT,
002592    SQLITE_MAX_VDBE_OP,
002593    SQLITE_MAX_FUNCTION_ARG,
002594    SQLITE_MAX_ATTACHED,
002595    SQLITE_MAX_LIKE_PATTERN_LENGTH,
002596    SQLITE_MAX_VARIABLE_NUMBER,      /* IMP: R-38091-32352 */
002597    SQLITE_MAX_TRIGGER_DEPTH,
002598    SQLITE_MAX_WORKER_THREADS,
002599  };
002600  
002601  /*
002602  ** Make sure the hard limits are set to reasonable values
002603  */
002604  #if SQLITE_MAX_LENGTH<100
002605  # error SQLITE_MAX_LENGTH must be at least 100
002606  #endif
002607  #if SQLITE_MAX_SQL_LENGTH<100
002608  # error SQLITE_MAX_SQL_LENGTH must be at least 100
002609  #endif
002610  #if SQLITE_MAX_SQL_LENGTH>SQLITE_MAX_LENGTH
002611  # error SQLITE_MAX_SQL_LENGTH must not be greater than SQLITE_MAX_LENGTH
002612  #endif
002613  #if SQLITE_MAX_COMPOUND_SELECT<2
002614  # error SQLITE_MAX_COMPOUND_SELECT must be at least 2
002615  #endif
002616  #if SQLITE_MAX_VDBE_OP<40
002617  # error SQLITE_MAX_VDBE_OP must be at least 40
002618  #endif
002619  #if SQLITE_MAX_FUNCTION_ARG<0 || SQLITE_MAX_FUNCTION_ARG>127
002620  # error SQLITE_MAX_FUNCTION_ARG must be between 0 and 127
002621  #endif
002622  #if SQLITE_MAX_ATTACHED<0 || SQLITE_MAX_ATTACHED>125
002623  # error SQLITE_MAX_ATTACHED must be between 0 and 125
002624  #endif
002625  #if SQLITE_MAX_LIKE_PATTERN_LENGTH<1
002626  # error SQLITE_MAX_LIKE_PATTERN_LENGTH must be at least 1
002627  #endif
002628  #if SQLITE_MAX_COLUMN>32767
002629  # error SQLITE_MAX_COLUMN must not exceed 32767
002630  #endif
002631  #if SQLITE_MAX_TRIGGER_DEPTH<1
002632  # error SQLITE_MAX_TRIGGER_DEPTH must be at least 1
002633  #endif
002634  #if SQLITE_MAX_WORKER_THREADS<0 || SQLITE_MAX_WORKER_THREADS>50
002635  # error SQLITE_MAX_WORKER_THREADS must be between 0 and 50
002636  #endif
002637  
002638  
002639  /*
002640  ** Change the value of a limit.  Report the old value.
002641  ** If an invalid limit index is supplied, report -1.
002642  ** Make no changes but still report the old value if the
002643  ** new limit is negative.
002644  **
002645  ** A new lower limit does not shrink existing constructs.
002646  ** It merely prevents new constructs that exceed the limit
002647  ** from forming.
002648  */
002649  int sqlite3_limit(sqlite3 *db, int limitId, int newLimit){
002650    int oldLimit;
002651  
002652  #ifdef SQLITE_ENABLE_API_ARMOR
002653    if( !sqlite3SafetyCheckOk(db) ){
002654      (void)SQLITE_MISUSE_BKPT;
002655      return -1;
002656    }
002657  #endif
002658  
002659    /* EVIDENCE-OF: R-30189-54097 For each limit category SQLITE_LIMIT_NAME
002660    ** there is a hard upper bound set at compile-time by a C preprocessor
002661    ** macro called SQLITE_MAX_NAME. (The "_LIMIT_" in the name is changed to
002662    ** "_MAX_".)
002663    */
002664    assert( aHardLimit[SQLITE_LIMIT_LENGTH]==SQLITE_MAX_LENGTH );
002665    assert( aHardLimit[SQLITE_LIMIT_SQL_LENGTH]==SQLITE_MAX_SQL_LENGTH );
002666    assert( aHardLimit[SQLITE_LIMIT_COLUMN]==SQLITE_MAX_COLUMN );
002667    assert( aHardLimit[SQLITE_LIMIT_EXPR_DEPTH]==SQLITE_MAX_EXPR_DEPTH );
002668    assert( aHardLimit[SQLITE_LIMIT_COMPOUND_SELECT]==SQLITE_MAX_COMPOUND_SELECT);
002669    assert( aHardLimit[SQLITE_LIMIT_VDBE_OP]==SQLITE_MAX_VDBE_OP );
002670    assert( aHardLimit[SQLITE_LIMIT_FUNCTION_ARG]==SQLITE_MAX_FUNCTION_ARG );
002671    assert( aHardLimit[SQLITE_LIMIT_ATTACHED]==SQLITE_MAX_ATTACHED );
002672    assert( aHardLimit[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]==
002673                                                 SQLITE_MAX_LIKE_PATTERN_LENGTH );
002674    assert( aHardLimit[SQLITE_LIMIT_VARIABLE_NUMBER]==SQLITE_MAX_VARIABLE_NUMBER);
002675    assert( aHardLimit[SQLITE_LIMIT_TRIGGER_DEPTH]==SQLITE_MAX_TRIGGER_DEPTH );
002676    assert( aHardLimit[SQLITE_LIMIT_WORKER_THREADS]==SQLITE_MAX_WORKER_THREADS );
002677    assert( SQLITE_LIMIT_WORKER_THREADS==(SQLITE_N_LIMIT-1) );
002678  
002679  
002680    if( limitId<0 || limitId>=SQLITE_N_LIMIT ){
002681      return -1;
002682    }
002683    oldLimit = db->aLimit[limitId];
002684    if( newLimit>=0 ){                   /* IMP: R-52476-28732 */
002685      if( newLimit>aHardLimit[limitId] ){
002686        newLimit = aHardLimit[limitId];  /* IMP: R-51463-25634 */
002687      }
002688      db->aLimit[limitId] = newLimit;
002689    }
002690    return oldLimit;                     /* IMP: R-53341-35419 */
002691  }
002692  
002693  /*
002694  ** This function is used to parse both URIs and non-URI filenames passed by the
002695  ** user to API functions sqlite3_open() or sqlite3_open_v2(), and for database
002696  ** URIs specified as part of ATTACH statements.
002697  **
002698  ** The first argument to this function is the name of the VFS to use (or
002699  ** a NULL to signify the default VFS) if the URI does not contain a "vfs=xxx"
002700  ** query parameter. The second argument contains the URI (or non-URI filename)
002701  ** itself. When this function is called the *pFlags variable should contain
002702  ** the default flags to open the database handle with. The value stored in
002703  ** *pFlags may be updated before returning if the URI filename contains 
002704  ** "cache=xxx" or "mode=xxx" query parameters.
002705  **
002706  ** If successful, SQLITE_OK is returned. In this case *ppVfs is set to point to
002707  ** the VFS that should be used to open the database file. *pzFile is set to
002708  ** point to a buffer containing the name of the file to open. It is the 
002709  ** responsibility of the caller to eventually call sqlite3_free() to release
002710  ** this buffer.
002711  **
002712  ** If an error occurs, then an SQLite error code is returned and *pzErrMsg
002713  ** may be set to point to a buffer containing an English language error 
002714  ** message. It is the responsibility of the caller to eventually release
002715  ** this buffer by calling sqlite3_free().
002716  */
002717  int sqlite3ParseUri(
002718    const char *zDefaultVfs,        /* VFS to use if no "vfs=xxx" query option */
002719    const char *zUri,               /* Nul-terminated URI to parse */
002720    unsigned int *pFlags,           /* IN/OUT: SQLITE_OPEN_XXX flags */
002721    sqlite3_vfs **ppVfs,            /* OUT: VFS to use */ 
002722    char **pzFile,                  /* OUT: Filename component of URI */
002723    char **pzErrMsg                 /* OUT: Error message (if rc!=SQLITE_OK) */
002724  ){
002725    int rc = SQLITE_OK;
002726    unsigned int flags = *pFlags;
002727    const char *zVfs = zDefaultVfs;
002728    char *zFile;
002729    char c;
002730    int nUri = sqlite3Strlen30(zUri);
002731  
002732    assert( *pzErrMsg==0 );
002733  
002734    if( ((flags & SQLITE_OPEN_URI)             /* IMP: R-48725-32206 */
002735              || sqlite3GlobalConfig.bOpenUri) /* IMP: R-51689-46548 */
002736     && nUri>=5 && memcmp(zUri, "file:", 5)==0 /* IMP: R-57884-37496 */
002737    ){
002738      char *zOpt;
002739      int eState;                   /* Parser state when parsing URI */
002740      int iIn;                      /* Input character index */
002741      int iOut = 0;                 /* Output character index */
002742      u64 nByte = nUri+2;           /* Bytes of space to allocate */
002743  
002744      /* Make sure the SQLITE_OPEN_URI flag is set to indicate to the VFS xOpen 
002745      ** method that there may be extra parameters following the file-name.  */
002746      flags |= SQLITE_OPEN_URI;
002747  
002748      for(iIn=0; iIn<nUri; iIn++) nByte += (zUri[iIn]=='&');
002749      zFile = sqlite3_malloc64(nByte);
002750      if( !zFile ) return SQLITE_NOMEM_BKPT;
002751  
002752      iIn = 5;
002753  #ifdef SQLITE_ALLOW_URI_AUTHORITY
002754      if( strncmp(zUri+5, "///", 3)==0 ){
002755        iIn = 7;
002756        /* The following condition causes URIs with five leading / characters
002757        ** like file://///host/path to be converted into UNCs like //host/path.
002758        ** The correct URI for that UNC has only two or four leading / characters
002759        ** file://host/path or file:////host/path.  But 5 leading slashes is a 
002760        ** common error, we are told, so we handle it as a special case. */
002761        if( strncmp(zUri+7, "///", 3)==0 ){ iIn++; }
002762      }else if( strncmp(zUri+5, "//localhost/", 12)==0 ){
002763        iIn = 16;
002764      }
002765  #else
002766      /* Discard the scheme and authority segments of the URI. */
002767      if( zUri[5]=='/' && zUri[6]=='/' ){
002768        iIn = 7;
002769        while( zUri[iIn] && zUri[iIn]!='/' ) iIn++;
002770        if( iIn!=7 && (iIn!=16 || memcmp("localhost", &zUri[7], 9)) ){
002771          *pzErrMsg = sqlite3_mprintf("invalid uri authority: %.*s", 
002772              iIn-7, &zUri[7]);
002773          rc = SQLITE_ERROR;
002774          goto parse_uri_out;
002775        }
002776      }
002777  #endif
002778  
002779      /* Copy the filename and any query parameters into the zFile buffer. 
002780      ** Decode %HH escape codes along the way. 
002781      **
002782      ** Within this loop, variable eState may be set to 0, 1 or 2, depending
002783      ** on the parsing context. As follows:
002784      **
002785      **   0: Parsing file-name.
002786      **   1: Parsing name section of a name=value query parameter.
002787      **   2: Parsing value section of a name=value query parameter.
002788      */
002789      eState = 0;
002790      while( (c = zUri[iIn])!=0 && c!='#' ){
002791        iIn++;
002792        if( c=='%' 
002793         && sqlite3Isxdigit(zUri[iIn]) 
002794         && sqlite3Isxdigit(zUri[iIn+1]) 
002795        ){
002796          int octet = (sqlite3HexToInt(zUri[iIn++]) << 4);
002797          octet += sqlite3HexToInt(zUri[iIn++]);
002798  
002799          assert( octet>=0 && octet<256 );
002800          if( octet==0 ){
002801  #ifndef SQLITE_ENABLE_URI_00_ERROR
002802            /* This branch is taken when "%00" appears within the URI. In this
002803            ** case we ignore all text in the remainder of the path, name or
002804            ** value currently being parsed. So ignore the current character
002805            ** and skip to the next "?", "=" or "&", as appropriate. */
002806            while( (c = zUri[iIn])!=0 && c!='#' 
002807                && (eState!=0 || c!='?')
002808                && (eState!=1 || (c!='=' && c!='&'))
002809                && (eState!=2 || c!='&')
002810            ){
002811              iIn++;
002812            }
002813            continue;
002814  #else
002815            /* If ENABLE_URI_00_ERROR is defined, "%00" in a URI is an error. */
002816            *pzErrMsg = sqlite3_mprintf("unexpected %%00 in uri");
002817            rc = SQLITE_ERROR;
002818            goto parse_uri_out;
002819  #endif
002820          }
002821          c = octet;
002822        }else if( eState==1 && (c=='&' || c=='=') ){
002823          if( zFile[iOut-1]==0 ){
002824            /* An empty option name. Ignore this option altogether. */
002825            while( zUri[iIn] && zUri[iIn]!='#' && zUri[iIn-1]!='&' ) iIn++;
002826            continue;
002827          }
002828          if( c=='&' ){
002829            zFile[iOut++] = '\0';
002830          }else{
002831            eState = 2;
002832          }
002833          c = 0;
002834        }else if( (eState==0 && c=='?') || (eState==2 && c=='&') ){
002835          c = 0;
002836          eState = 1;
002837        }
002838        zFile[iOut++] = c;
002839      }
002840      if( eState==1 ) zFile[iOut++] = '\0';
002841      zFile[iOut++] = '\0';
002842      zFile[iOut++] = '\0';
002843  
002844      /* Check if there were any options specified that should be interpreted 
002845      ** here. Options that are interpreted here include "vfs" and those that
002846      ** correspond to flags that may be passed to the sqlite3_open_v2()
002847      ** method. */
002848      zOpt = &zFile[sqlite3Strlen30(zFile)+1];
002849      while( zOpt[0] ){
002850        int nOpt = sqlite3Strlen30(zOpt);
002851        char *zVal = &zOpt[nOpt+1];
002852        int nVal = sqlite3Strlen30(zVal);
002853  
002854        if( nOpt==3 && memcmp("vfs", zOpt, 3)==0 ){
002855          zVfs = zVal;
002856        }else{
002857          struct OpenMode {
002858            const char *z;
002859            int mode;
002860          } *aMode = 0;
002861          char *zModeType = 0;
002862          int mask = 0;
002863          int limit = 0;
002864  
002865          if( nOpt==5 && memcmp("cache", zOpt, 5)==0 ){
002866            static struct OpenMode aCacheMode[] = {
002867              { "shared",  SQLITE_OPEN_SHAREDCACHE },
002868              { "private", SQLITE_OPEN_PRIVATECACHE },
002869              { 0, 0 }
002870            };
002871  
002872            mask = SQLITE_OPEN_SHAREDCACHE|SQLITE_OPEN_PRIVATECACHE;
002873            aMode = aCacheMode;
002874            limit = mask;
002875            zModeType = "cache";
002876          }
002877          if( nOpt==4 && memcmp("mode", zOpt, 4)==0 ){
002878            static struct OpenMode aOpenMode[] = {
002879              { "ro",  SQLITE_OPEN_READONLY },
002880              { "rw",  SQLITE_OPEN_READWRITE }, 
002881              { "rwc", SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE },
002882              { "memory", SQLITE_OPEN_MEMORY },
002883              { 0, 0 }
002884            };
002885  
002886            mask = SQLITE_OPEN_READONLY | SQLITE_OPEN_READWRITE
002887                     | SQLITE_OPEN_CREATE | SQLITE_OPEN_MEMORY;
002888            aMode = aOpenMode;
002889            limit = mask & flags;
002890            zModeType = "access";
002891          }
002892  
002893          if( aMode ){
002894            int i;
002895            int mode = 0;
002896            for(i=0; aMode[i].z; i++){
002897              const char *z = aMode[i].z;
002898              if( nVal==sqlite3Strlen30(z) && 0==memcmp(zVal, z, nVal) ){
002899                mode = aMode[i].mode;
002900                break;
002901              }
002902            }
002903            if( mode==0 ){
002904              *pzErrMsg = sqlite3_mprintf("no such %s mode: %s", zModeType, zVal);
002905              rc = SQLITE_ERROR;
002906              goto parse_uri_out;
002907            }
002908            if( (mode & ~SQLITE_OPEN_MEMORY)>limit ){
002909              *pzErrMsg = sqlite3_mprintf("%s mode not allowed: %s",
002910                                          zModeType, zVal);
002911              rc = SQLITE_PERM;
002912              goto parse_uri_out;
002913            }
002914            flags = (flags & ~mask) | mode;
002915          }
002916        }
002917  
002918        zOpt = &zVal[nVal+1];
002919      }
002920  
002921    }else{
002922      zFile = sqlite3_malloc64(nUri+2);
002923      if( !zFile ) return SQLITE_NOMEM_BKPT;
002924      if( nUri ){
002925        memcpy(zFile, zUri, nUri);
002926      }
002927      zFile[nUri] = '\0';
002928      zFile[nUri+1] = '\0';
002929      flags &= ~SQLITE_OPEN_URI;
002930    }
002931  
002932    *ppVfs = sqlite3_vfs_find(zVfs);
002933    if( *ppVfs==0 ){
002934      *pzErrMsg = sqlite3_mprintf("no such vfs: %s", zVfs);
002935      rc = SQLITE_ERROR;
002936    }
002937   parse_uri_out:
002938    if( rc!=SQLITE_OK ){
002939      sqlite3_free(zFile);
002940      zFile = 0;
002941    }
002942    *pFlags = flags;
002943    *pzFile = zFile;
002944    return rc;
002945  }
002946  
002947  #if defined(SQLITE_HAS_CODEC)
002948  /*
002949  ** Process URI filename query parameters relevant to the SQLite Encryption
002950  ** Extension.  Return true if any of the relevant query parameters are
002951  ** seen and return false if not.
002952  */
002953  int sqlite3CodecQueryParameters(
002954    sqlite3 *db,           /* Database connection */
002955    const char *zDb,       /* Which schema is being created/attached */
002956    const char *zUri       /* URI filename */
002957  ){
002958    const char *zKey;
002959    if( (zKey = sqlite3_uri_parameter(zUri, "hexkey"))!=0 && zKey[0] ){
002960      u8 iByte;
002961      int i;
002962      char zDecoded[40];
002963      for(i=0, iByte=0; i<sizeof(zDecoded)*2 && sqlite3Isxdigit(zKey[i]); i++){
002964        iByte = (iByte<<4) + sqlite3HexToInt(zKey[i]);
002965        if( (i&1)!=0 ) zDecoded[i/2] = iByte;
002966      }
002967      sqlite3_key_v2(db, zDb, zDecoded, i/2);
002968      return 1;
002969    }else if( (zKey = sqlite3_uri_parameter(zUri, "key"))!=0 ){
002970      sqlite3_key_v2(db, zDb, zKey, sqlite3Strlen30(zKey));
002971      return 1;
002972    }else if( (zKey = sqlite3_uri_parameter(zUri, "textkey"))!=0 ){
002973      sqlite3_key_v2(db, zDb, zKey, -1);
002974      return 1;
002975    }else{
002976      return 0;
002977    }
002978  }
002979  #endif
002980  
002981  
002982  /*
002983  ** This routine does the work of opening a database on behalf of
002984  ** sqlite3_open() and sqlite3_open16(). The database filename "zFilename"  
002985  ** is UTF-8 encoded.
002986  */
002987  static int openDatabase(
002988    const char *zFilename, /* Database filename UTF-8 encoded */
002989    sqlite3 **ppDb,        /* OUT: Returned database handle */
002990    unsigned int flags,    /* Operational flags */
002991    const char *zVfs       /* Name of the VFS to use */
002992  ){
002993    sqlite3 *db;                    /* Store allocated handle here */
002994    int rc;                         /* Return code */
002995    int isThreadsafe;               /* True for threadsafe connections */
002996    char *zOpen = 0;                /* Filename argument to pass to BtreeOpen() */
002997    char *zErrMsg = 0;              /* Error message from sqlite3ParseUri() */
002998  
002999  #ifdef SQLITE_ENABLE_API_ARMOR
003000    if( ppDb==0 ) return SQLITE_MISUSE_BKPT;
003001  #endif
003002    *ppDb = 0;
003003  #ifndef SQLITE_OMIT_AUTOINIT
003004    rc = sqlite3_initialize();
003005    if( rc ) return rc;
003006  #endif
003007  
003008    if( sqlite3GlobalConfig.bCoreMutex==0 ){
003009      isThreadsafe = 0;
003010    }else if( flags & SQLITE_OPEN_NOMUTEX ){
003011      isThreadsafe = 0;
003012    }else if( flags & SQLITE_OPEN_FULLMUTEX ){
003013      isThreadsafe = 1;
003014    }else{
003015      isThreadsafe = sqlite3GlobalConfig.bFullMutex;
003016    }
003017  
003018    if( flags & SQLITE_OPEN_PRIVATECACHE ){
003019      flags &= ~SQLITE_OPEN_SHAREDCACHE;
003020    }else if( sqlite3GlobalConfig.sharedCacheEnabled ){
003021      flags |= SQLITE_OPEN_SHAREDCACHE;
003022    }
003023  
003024    /* Remove harmful bits from the flags parameter
003025    **
003026    ** The SQLITE_OPEN_NOMUTEX and SQLITE_OPEN_FULLMUTEX flags were
003027    ** dealt with in the previous code block.  Besides these, the only
003028    ** valid input flags for sqlite3_open_v2() are SQLITE_OPEN_READONLY,
003029    ** SQLITE_OPEN_READWRITE, SQLITE_OPEN_CREATE, SQLITE_OPEN_SHAREDCACHE,
003030    ** SQLITE_OPEN_PRIVATECACHE, and some reserved bits.  Silently mask
003031    ** off all other flags.
003032    */
003033    flags &=  ~( SQLITE_OPEN_DELETEONCLOSE |
003034                 SQLITE_OPEN_EXCLUSIVE |
003035                 SQLITE_OPEN_MAIN_DB |
003036                 SQLITE_OPEN_TEMP_DB | 
003037                 SQLITE_OPEN_TRANSIENT_DB | 
003038                 SQLITE_OPEN_MAIN_JOURNAL | 
003039                 SQLITE_OPEN_TEMP_JOURNAL | 
003040                 SQLITE_OPEN_SUBJOURNAL | 
003041                 SQLITE_OPEN_MASTER_JOURNAL |
003042                 SQLITE_OPEN_NOMUTEX |
003043                 SQLITE_OPEN_FULLMUTEX |
003044                 SQLITE_OPEN_WAL
003045               );
003046  
003047    /* Allocate the sqlite data structure */
003048    db = sqlite3MallocZero( sizeof(sqlite3) );
003049    if( db==0 ) goto opendb_out;
003050    if( isThreadsafe 
003051  #ifdef SQLITE_ENABLE_MULTITHREADED_CHECKS
003052     || sqlite3GlobalConfig.bCoreMutex
003053  #endif
003054    ){
003055      db->mutex = sqlite3MutexAlloc(SQLITE_MUTEX_RECURSIVE);
003056      if( db->mutex==0 ){
003057        sqlite3_free(db);
003058        db = 0;
003059        goto opendb_out;
003060      }
003061      if( isThreadsafe==0 ){
003062        sqlite3MutexWarnOnContention(db->mutex);
003063      }
003064    }
003065    sqlite3_mutex_enter(db->mutex);
003066    db->errMask = 0xff;
003067    db->nDb = 2;
003068    db->magic = SQLITE_MAGIC_BUSY;
003069    db->aDb = db->aDbStatic;
003070    db->lookaside.bDisable = 1;
003071    db->lookaside.sz = 0;
003072  
003073    assert( sizeof(db->aLimit)==sizeof(aHardLimit) );
003074    memcpy(db->aLimit, aHardLimit, sizeof(db->aLimit));
003075    db->aLimit[SQLITE_LIMIT_WORKER_THREADS] = SQLITE_DEFAULT_WORKER_THREADS;
003076    db->autoCommit = 1;
003077    db->nextAutovac = -1;
003078    db->szMmap = sqlite3GlobalConfig.szMmap;
003079    db->nextPagesize = 0;
003080    db->nMaxSorterMmap = 0x7FFFFFFF;
003081    db->flags |= SQLITE_ShortColNames
003082                   | SQLITE_EnableTrigger
003083                   | SQLITE_EnableView
003084                   | SQLITE_CacheSpill
003085  
003086  /* The SQLITE_DQS compile-time option determines the default settings
003087  ** for SQLITE_DBCONFIG_DQS_DDL and SQLITE_DBCONFIG_DQS_DML.
003088  **
003089  **    SQLITE_DQS     SQLITE_DBCONFIG_DQS_DDL    SQLITE_DBCONFIG_DQS_DML
003090  **    ----------     -----------------------    -----------------------
003091  **     undefined               on                          on   
003092  **         3                   on                          on
003093  **         2                   on                         off
003094  **         1                  off                          on
003095  **         0                  off                         off
003096  **
003097  ** Legacy behavior is 3 (double-quoted string literals are allowed anywhere)
003098  ** and so that is the default.  But developers are encouranged to use
003099  ** -DSQLITE_DQS=0 (best) or -DSQLITE_DQS=1 (second choice) if possible.
003100  */
003101  #if !defined(SQLITE_DQS)
003102  # define SQLITE_DQS 3
003103  #endif
003104  #if (SQLITE_DQS&1)==1
003105                   | SQLITE_DqsDML
003106  #endif
003107  #if (SQLITE_DQS&2)==2
003108                   | SQLITE_DqsDDL
003109  #endif
003110  
003111  #if !defined(SQLITE_DEFAULT_AUTOMATIC_INDEX) || SQLITE_DEFAULT_AUTOMATIC_INDEX
003112                   | SQLITE_AutoIndex
003113  #endif
003114  #if SQLITE_DEFAULT_CKPTFULLFSYNC
003115                   | SQLITE_CkptFullFSync
003116  #endif
003117  #if SQLITE_DEFAULT_FILE_FORMAT<4
003118                   | SQLITE_LegacyFileFmt
003119  #endif
003120  #ifdef SQLITE_ENABLE_LOAD_EXTENSION
003121                   | SQLITE_LoadExtension
003122  #endif
003123  #if SQLITE_DEFAULT_RECURSIVE_TRIGGERS
003124                   | SQLITE_RecTriggers
003125  #endif
003126  #if defined(SQLITE_DEFAULT_FOREIGN_KEYS) && SQLITE_DEFAULT_FOREIGN_KEYS
003127                   | SQLITE_ForeignKeys
003128  #endif
003129  #if defined(SQLITE_REVERSE_UNORDERED_SELECTS)
003130                   | SQLITE_ReverseOrder
003131  #endif
003132  #if defined(SQLITE_ENABLE_OVERSIZE_CELL_CHECK)
003133                   | SQLITE_CellSizeCk
003134  #endif
003135  #if defined(SQLITE_ENABLE_FTS3_TOKENIZER)
003136                   | SQLITE_Fts3Tokenizer
003137  #endif
003138  #if defined(SQLITE_ENABLE_QPSG)
003139                   | SQLITE_EnableQPSG
003140  #endif
003141  #if defined(SQLITE_DEFAULT_DEFENSIVE)
003142                   | SQLITE_Defensive
003143  #endif
003144        ;
003145    sqlite3HashInit(&db->aCollSeq);
003146  #ifndef SQLITE_OMIT_VIRTUALTABLE
003147    sqlite3HashInit(&db->aModule);
003148  #endif
003149  
003150    /* Add the default collation sequence BINARY. BINARY works for both UTF-8
003151    ** and UTF-16, so add a version for each to avoid any unnecessary
003152    ** conversions. The only error that can occur here is a malloc() failure.
003153    **
003154    ** EVIDENCE-OF: R-52786-44878 SQLite defines three built-in collating
003155    ** functions:
003156    */
003157    createCollation(db, sqlite3StrBINARY, SQLITE_UTF8, 0, binCollFunc, 0);
003158    createCollation(db, sqlite3StrBINARY, SQLITE_UTF16BE, 0, binCollFunc, 0);
003159    createCollation(db, sqlite3StrBINARY, SQLITE_UTF16LE, 0, binCollFunc, 0);
003160    createCollation(db, "NOCASE", SQLITE_UTF8, 0, nocaseCollatingFunc, 0);
003161    createCollation(db, "RTRIM", SQLITE_UTF8, 0, rtrimCollFunc, 0);
003162    if( db->mallocFailed ){
003163      goto opendb_out;
003164    }
003165    /* EVIDENCE-OF: R-08308-17224 The default collating function for all
003166    ** strings is BINARY. 
003167    */
003168    db->pDfltColl = sqlite3FindCollSeq(db, SQLITE_UTF8, sqlite3StrBINARY, 0);
003169    assert( db->pDfltColl!=0 );
003170  
003171    /* Parse the filename/URI argument
003172    **
003173    ** Only allow sensible combinations of bits in the flags argument.  
003174    ** Throw an error if any non-sense combination is used.  If we
003175    ** do not block illegal combinations here, it could trigger
003176    ** assert() statements in deeper layers.  Sensible combinations
003177    ** are:
003178    **
003179    **  1:  SQLITE_OPEN_READONLY
003180    **  2:  SQLITE_OPEN_READWRITE
003181    **  6:  SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE
003182    */
003183    db->openFlags = flags;
003184    assert( SQLITE_OPEN_READONLY  == 0x01 );
003185    assert( SQLITE_OPEN_READWRITE == 0x02 );
003186    assert( SQLITE_OPEN_CREATE    == 0x04 );
003187    testcase( (1<<(flags&7))==0x02 ); /* READONLY */
003188    testcase( (1<<(flags&7))==0x04 ); /* READWRITE */
003189    testcase( (1<<(flags&7))==0x40 ); /* READWRITE | CREATE */
003190    if( ((1<<(flags&7)) & 0x46)==0 ){
003191      rc = SQLITE_MISUSE_BKPT;  /* IMP: R-65497-44594 */
003192    }else{
003193      rc = sqlite3ParseUri(zVfs, zFilename, &flags, &db->pVfs, &zOpen, &zErrMsg);
003194    }
003195    if( rc!=SQLITE_OK ){
003196      if( rc==SQLITE_NOMEM ) sqlite3OomFault(db);
003197      sqlite3ErrorWithMsg(db, rc, zErrMsg ? "%s" : 0, zErrMsg);
003198      sqlite3_free(zErrMsg);
003199      goto opendb_out;
003200    }
003201  
003202    /* Open the backend database driver */
003203    rc = sqlite3BtreeOpen(db->pVfs, zOpen, db, &db->aDb[0].pBt, 0,
003204                          flags | SQLITE_OPEN_MAIN_DB);
003205    if( rc!=SQLITE_OK ){
003206      if( rc==SQLITE_IOERR_NOMEM ){
003207        rc = SQLITE_NOMEM_BKPT;
003208      }
003209      sqlite3Error(db, rc);
003210      goto opendb_out;
003211    }
003212    sqlite3BtreeEnter(db->aDb[0].pBt);
003213    db->aDb[0].pSchema = sqlite3SchemaGet(db, db->aDb[0].pBt);
003214    if( !db->mallocFailed ) ENC(db) = SCHEMA_ENC(db);
003215    sqlite3BtreeLeave(db->aDb[0].pBt);
003216    db->aDb[1].pSchema = sqlite3SchemaGet(db, 0);
003217  
003218    /* The default safety_level for the main database is FULL; for the temp
003219    ** database it is OFF. This matches the pager layer defaults.  
003220    */
003221    db->aDb[0].zDbSName = "main";
003222    db->aDb[0].safety_level = SQLITE_DEFAULT_SYNCHRONOUS+1;
003223    db->aDb[1].zDbSName = "temp";
003224    db->aDb[1].safety_level = PAGER_SYNCHRONOUS_OFF;
003225  
003226    db->magic = SQLITE_MAGIC_OPEN;
003227    if( db->mallocFailed ){
003228      goto opendb_out;
003229    }
003230  
003231    /* Register all built-in functions, but do not attempt to read the
003232    ** database schema yet. This is delayed until the first time the database
003233    ** is accessed.
003234    */
003235    sqlite3Error(db, SQLITE_OK);
003236    sqlite3RegisterPerConnectionBuiltinFunctions(db);
003237    rc = sqlite3_errcode(db);
003238  
003239  #ifdef SQLITE_ENABLE_FTS5
003240    /* Register any built-in FTS5 module before loading the automatic
003241    ** extensions. This allows automatic extensions to register FTS5 
003242    ** tokenizers and auxiliary functions.  */
003243    if( !db->mallocFailed && rc==SQLITE_OK ){
003244      rc = sqlite3Fts5Init(db);
003245    }
003246  #endif
003247  
003248    /* Load automatic extensions - extensions that have been registered
003249    ** using the sqlite3_automatic_extension() API.
003250    */
003251    if( rc==SQLITE_OK ){
003252      sqlite3AutoLoadExtensions(db);
003253      rc = sqlite3_errcode(db);
003254      if( rc!=SQLITE_OK ){
003255        goto opendb_out;
003256      }
003257    }
003258  
003259  #ifdef SQLITE_ENABLE_FTS1
003260    if( !db->mallocFailed ){
003261      extern int sqlite3Fts1Init(sqlite3*);
003262      rc = sqlite3Fts1Init(db);
003263    }
003264  #endif
003265  
003266  #ifdef SQLITE_ENABLE_FTS2
003267    if( !db->mallocFailed && rc==SQLITE_OK ){
003268      extern int sqlite3Fts2Init(sqlite3*);
003269      rc = sqlite3Fts2Init(db);
003270    }
003271  #endif
003272  
003273  #ifdef SQLITE_ENABLE_FTS3 /* automatically defined by SQLITE_ENABLE_FTS4 */
003274    if( !db->mallocFailed && rc==SQLITE_OK ){
003275      rc = sqlite3Fts3Init(db);
003276    }
003277  #endif
003278  
003279  #if defined(SQLITE_ENABLE_ICU) || defined(SQLITE_ENABLE_ICU_COLLATIONS)
003280    if( !db->mallocFailed && rc==SQLITE_OK ){
003281      rc = sqlite3IcuInit(db);
003282    }
003283  #endif
003284  
003285  #ifdef SQLITE_ENABLE_RTREE
003286    if( !db->mallocFailed && rc==SQLITE_OK){
003287      rc = sqlite3RtreeInit(db);
003288    }
003289  #endif
003290  
003291  #ifdef SQLITE_ENABLE_DBPAGE_VTAB
003292    if( !db->mallocFailed && rc==SQLITE_OK){
003293      rc = sqlite3DbpageRegister(db);
003294    }
003295  #endif
003296  
003297  #ifdef SQLITE_ENABLE_DBSTAT_VTAB
003298    if( !db->mallocFailed && rc==SQLITE_OK){
003299      rc = sqlite3DbstatRegister(db);
003300    }
003301  #endif
003302  
003303  #ifdef SQLITE_ENABLE_JSON1
003304    if( !db->mallocFailed && rc==SQLITE_OK){
003305      rc = sqlite3Json1Init(db);
003306    }
003307  #endif
003308  
003309  #ifdef SQLITE_ENABLE_STMTVTAB
003310    if( !db->mallocFailed && rc==SQLITE_OK){
003311      rc = sqlite3StmtVtabInit(db);
003312    }
003313  #endif
003314  
003315    /* -DSQLITE_DEFAULT_LOCKING_MODE=1 makes EXCLUSIVE the default locking
003316    ** mode.  -DSQLITE_DEFAULT_LOCKING_MODE=0 make NORMAL the default locking
003317    ** mode.  Doing nothing at all also makes NORMAL the default.
003318    */
003319  #ifdef SQLITE_DEFAULT_LOCKING_MODE
003320    db->dfltLockMode = SQLITE_DEFAULT_LOCKING_MODE;
003321    sqlite3PagerLockingMode(sqlite3BtreePager(db->aDb[0].pBt),
003322                            SQLITE_DEFAULT_LOCKING_MODE);
003323  #endif
003324  
003325    if( rc ) sqlite3Error(db, rc);
003326  
003327    /* Enable the lookaside-malloc subsystem */
003328    setupLookaside(db, 0, sqlite3GlobalConfig.szLookaside,
003329                          sqlite3GlobalConfig.nLookaside);
003330  
003331    sqlite3_wal_autocheckpoint(db, SQLITE_DEFAULT_WAL_AUTOCHECKPOINT);
003332  
003333  opendb_out:
003334    if( db ){
003335      assert( db->mutex!=0 || isThreadsafe==0
003336             || sqlite3GlobalConfig.bFullMutex==0 );
003337      sqlite3_mutex_leave(db->mutex);
003338    }
003339    rc = sqlite3_errcode(db);
003340    assert( db!=0 || rc==SQLITE_NOMEM );
003341    if( rc==SQLITE_NOMEM ){
003342      sqlite3_close(db);
003343      db = 0;
003344    }else if( rc!=SQLITE_OK ){
003345      db->magic = SQLITE_MAGIC_SICK;
003346    }
003347    *ppDb = db;
003348  #ifdef SQLITE_ENABLE_SQLLOG
003349    if( sqlite3GlobalConfig.xSqllog ){
003350      /* Opening a db handle. Fourth parameter is passed 0. */
003351      void *pArg = sqlite3GlobalConfig.pSqllogArg;
003352      sqlite3GlobalConfig.xSqllog(pArg, db, zFilename, 0);
003353    }
003354  #endif
003355  #if defined(SQLITE_HAS_CODEC)
003356    if( rc==SQLITE_OK ) sqlite3CodecQueryParameters(db, 0, zOpen);
003357  #endif
003358    sqlite3_free(zOpen);
003359    return rc & 0xff;
003360  }
003361  
003362  
003363  /*
003364  ** Open a new database handle.
003365  */
003366  int sqlite3_open(
003367    const char *zFilename, 
003368    sqlite3 **ppDb 
003369  ){
003370    return openDatabase(zFilename, ppDb,
003371                        SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
003372  }
003373  int sqlite3_open_v2(
003374    const char *filename,   /* Database filename (UTF-8) */
003375    sqlite3 **ppDb,         /* OUT: SQLite db handle */
003376    int flags,              /* Flags */
003377    const char *zVfs        /* Name of VFS module to use */
003378  ){
003379    return openDatabase(filename, ppDb, (unsigned int)flags, zVfs);
003380  }
003381  
003382  #ifndef SQLITE_OMIT_UTF16
003383  /*
003384  ** Open a new database handle.
003385  */
003386  int sqlite3_open16(
003387    const void *zFilename, 
003388    sqlite3 **ppDb
003389  ){
003390    char const *zFilename8;   /* zFilename encoded in UTF-8 instead of UTF-16 */
003391    sqlite3_value *pVal;
003392    int rc;
003393  
003394  #ifdef SQLITE_ENABLE_API_ARMOR
003395    if( ppDb==0 ) return SQLITE_MISUSE_BKPT;
003396  #endif
003397    *ppDb = 0;
003398  #ifndef SQLITE_OMIT_AUTOINIT
003399    rc = sqlite3_initialize();
003400    if( rc ) return rc;
003401  #endif
003402    if( zFilename==0 ) zFilename = "\000\000";
003403    pVal = sqlite3ValueNew(0);
003404    sqlite3ValueSetStr(pVal, -1, zFilename, SQLITE_UTF16NATIVE, SQLITE_STATIC);
003405    zFilename8 = sqlite3ValueText(pVal, SQLITE_UTF8);
003406    if( zFilename8 ){
003407      rc = openDatabase(zFilename8, ppDb,
003408                        SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
003409      assert( *ppDb || rc==SQLITE_NOMEM );
003410      if( rc==SQLITE_OK && !DbHasProperty(*ppDb, 0, DB_SchemaLoaded) ){
003411        SCHEMA_ENC(*ppDb) = ENC(*ppDb) = SQLITE_UTF16NATIVE;
003412      }
003413    }else{
003414      rc = SQLITE_NOMEM_BKPT;
003415    }
003416    sqlite3ValueFree(pVal);
003417  
003418    return rc & 0xff;
003419  }
003420  #endif /* SQLITE_OMIT_UTF16 */
003421  
003422  /*
003423  ** Register a new collation sequence with the database handle db.
003424  */
003425  int sqlite3_create_collation(
003426    sqlite3* db, 
003427    const char *zName, 
003428    int enc, 
003429    void* pCtx,
003430    int(*xCompare)(void*,int,const void*,int,const void*)
003431  ){
003432    return sqlite3_create_collation_v2(db, zName, enc, pCtx, xCompare, 0);
003433  }
003434  
003435  /*
003436  ** Register a new collation sequence with the database handle db.
003437  */
003438  int sqlite3_create_collation_v2(
003439    sqlite3* db, 
003440    const char *zName, 
003441    int enc, 
003442    void* pCtx,
003443    int(*xCompare)(void*,int,const void*,int,const void*),
003444    void(*xDel)(void*)
003445  ){
003446    int rc;
003447  
003448  #ifdef SQLITE_ENABLE_API_ARMOR
003449    if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
003450  #endif
003451    sqlite3_mutex_enter(db->mutex);
003452    assert( !db->mallocFailed );
003453    rc = createCollation(db, zName, (u8)enc, pCtx, xCompare, xDel);
003454    rc = sqlite3ApiExit(db, rc);
003455    sqlite3_mutex_leave(db->mutex);
003456    return rc;
003457  }
003458  
003459  #ifndef SQLITE_OMIT_UTF16
003460  /*
003461  ** Register a new collation sequence with the database handle db.
003462  */
003463  int sqlite3_create_collation16(
003464    sqlite3* db, 
003465    const void *zName,
003466    int enc, 
003467    void* pCtx,
003468    int(*xCompare)(void*,int,const void*,int,const void*)
003469  ){
003470    int rc = SQLITE_OK;
003471    char *zName8;
003472  
003473  #ifdef SQLITE_ENABLE_API_ARMOR
003474    if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
003475  #endif
003476    sqlite3_mutex_enter(db->mutex);
003477    assert( !db->mallocFailed );
003478    zName8 = sqlite3Utf16to8(db, zName, -1, SQLITE_UTF16NATIVE);
003479    if( zName8 ){
003480      rc = createCollation(db, zName8, (u8)enc, pCtx, xCompare, 0);
003481      sqlite3DbFree(db, zName8);
003482    }
003483    rc = sqlite3ApiExit(db, rc);
003484    sqlite3_mutex_leave(db->mutex);
003485    return rc;
003486  }
003487  #endif /* SQLITE_OMIT_UTF16 */
003488  
003489  /*
003490  ** Register a collation sequence factory callback with the database handle
003491  ** db. Replace any previously installed collation sequence factory.
003492  */
003493  int sqlite3_collation_needed(
003494    sqlite3 *db, 
003495    void *pCollNeededArg, 
003496    void(*xCollNeeded)(void*,sqlite3*,int eTextRep,const char*)
003497  ){
003498  #ifdef SQLITE_ENABLE_API_ARMOR
003499    if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
003500  #endif
003501    sqlite3_mutex_enter(db->mutex);
003502    db->xCollNeeded = xCollNeeded;
003503    db->xCollNeeded16 = 0;
003504    db->pCollNeededArg = pCollNeededArg;
003505    sqlite3_mutex_leave(db->mutex);
003506    return SQLITE_OK;
003507  }
003508  
003509  #ifndef SQLITE_OMIT_UTF16
003510  /*
003511  ** Register a collation sequence factory callback with the database handle
003512  ** db. Replace any previously installed collation sequence factory.
003513  */
003514  int sqlite3_collation_needed16(
003515    sqlite3 *db, 
003516    void *pCollNeededArg, 
003517    void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*)
003518  ){
003519  #ifdef SQLITE_ENABLE_API_ARMOR
003520    if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
003521  #endif
003522    sqlite3_mutex_enter(db->mutex);
003523    db->xCollNeeded = 0;
003524    db->xCollNeeded16 = xCollNeeded16;
003525    db->pCollNeededArg = pCollNeededArg;
003526    sqlite3_mutex_leave(db->mutex);
003527    return SQLITE_OK;
003528  }
003529  #endif /* SQLITE_OMIT_UTF16 */
003530  
003531  #ifndef SQLITE_OMIT_DEPRECATED
003532  /*
003533  ** This function is now an anachronism. It used to be used to recover from a
003534  ** malloc() failure, but SQLite now does this automatically.
003535  */
003536  int sqlite3_global_recover(void){
003537    return SQLITE_OK;
003538  }
003539  #endif
003540  
003541  /*
003542  ** Test to see whether or not the database connection is in autocommit
003543  ** mode.  Return TRUE if it is and FALSE if not.  Autocommit mode is on
003544  ** by default.  Autocommit is disabled by a BEGIN statement and reenabled
003545  ** by the next COMMIT or ROLLBACK.
003546  */
003547  int sqlite3_get_autocommit(sqlite3 *db){
003548  #ifdef SQLITE_ENABLE_API_ARMOR
003549    if( !sqlite3SafetyCheckOk(db) ){
003550      (void)SQLITE_MISUSE_BKPT;
003551      return 0;
003552    }
003553  #endif
003554    return db->autoCommit;
003555  }
003556  
003557  /*
003558  ** The following routines are substitutes for constants SQLITE_CORRUPT,
003559  ** SQLITE_MISUSE, SQLITE_CANTOPEN, SQLITE_NOMEM and possibly other error
003560  ** constants.  They serve two purposes:
003561  **
003562  **   1.  Serve as a convenient place to set a breakpoint in a debugger
003563  **       to detect when version error conditions occurs.
003564  **
003565  **   2.  Invoke sqlite3_log() to provide the source code location where
003566  **       a low-level error is first detected.
003567  */
003568  int sqlite3ReportError(int iErr, int lineno, const char *zType){
003569    sqlite3_log(iErr, "%s at line %d of [%.10s]",
003570                zType, lineno, 20+sqlite3_sourceid());
003571    return iErr;
003572  }
003573  int sqlite3CorruptError(int lineno){
003574    testcase( sqlite3GlobalConfig.xLog!=0 );
003575    return sqlite3ReportError(SQLITE_CORRUPT, lineno, "database corruption");
003576  }
003577  int sqlite3MisuseError(int lineno){
003578    testcase( sqlite3GlobalConfig.xLog!=0 );
003579    return sqlite3ReportError(SQLITE_MISUSE, lineno, "misuse");
003580  }
003581  int sqlite3CantopenError(int lineno){
003582    testcase( sqlite3GlobalConfig.xLog!=0 );
003583    return sqlite3ReportError(SQLITE_CANTOPEN, lineno, "cannot open file");
003584  }
003585  #ifdef SQLITE_DEBUG
003586  int sqlite3CorruptPgnoError(int lineno, Pgno pgno){
003587    char zMsg[100];
003588    sqlite3_snprintf(sizeof(zMsg), zMsg, "database corruption page %d", pgno);
003589    testcase( sqlite3GlobalConfig.xLog!=0 );
003590    return sqlite3ReportError(SQLITE_CORRUPT, lineno, zMsg);
003591  }
003592  int sqlite3NomemError(int lineno){
003593    testcase( sqlite3GlobalConfig.xLog!=0 );
003594    return sqlite3ReportError(SQLITE_NOMEM, lineno, "OOM");
003595  }
003596  int sqlite3IoerrnomemError(int lineno){
003597    testcase( sqlite3GlobalConfig.xLog!=0 );
003598    return sqlite3ReportError(SQLITE_IOERR_NOMEM, lineno, "I/O OOM error");
003599  }
003600  #endif
003601  
003602  #ifndef SQLITE_OMIT_DEPRECATED
003603  /*
003604  ** This is a convenience routine that makes sure that all thread-specific
003605  ** data for this thread has been deallocated.
003606  **
003607  ** SQLite no longer uses thread-specific data so this routine is now a
003608  ** no-op.  It is retained for historical compatibility.
003609  */
003610  void sqlite3_thread_cleanup(void){
003611  }
003612  #endif
003613  
003614  /*
003615  ** Return meta information about a specific column of a database table.
003616  ** See comment in sqlite3.h (sqlite.h.in) for details.
003617  */
003618  int sqlite3_table_column_metadata(
003619    sqlite3 *db,                /* Connection handle */
003620    const char *zDbName,        /* Database name or NULL */
003621    const char *zTableName,     /* Table name */
003622    const char *zColumnName,    /* Column name */
003623    char const **pzDataType,    /* OUTPUT: Declared data type */
003624    char const **pzCollSeq,     /* OUTPUT: Collation sequence name */
003625    int *pNotNull,              /* OUTPUT: True if NOT NULL constraint exists */
003626    int *pPrimaryKey,           /* OUTPUT: True if column part of PK */
003627    int *pAutoinc               /* OUTPUT: True if column is auto-increment */
003628  ){
003629    int rc;
003630    char *zErrMsg = 0;
003631    Table *pTab = 0;
003632    Column *pCol = 0;
003633    int iCol = 0;
003634    char const *zDataType = 0;
003635    char const *zCollSeq = 0;
003636    int notnull = 0;
003637    int primarykey = 0;
003638    int autoinc = 0;
003639  
003640  
003641  #ifdef SQLITE_ENABLE_API_ARMOR
003642    if( !sqlite3SafetyCheckOk(db) || zTableName==0 ){
003643      return SQLITE_MISUSE_BKPT;
003644    }
003645  #endif
003646  
003647    /* Ensure the database schema has been loaded */
003648    sqlite3_mutex_enter(db->mutex);
003649    sqlite3BtreeEnterAll(db);
003650    rc = sqlite3Init(db, &zErrMsg);
003651    if( SQLITE_OK!=rc ){
003652      goto error_out;
003653    }
003654  
003655    /* Locate the table in question */
003656    pTab = sqlite3FindTable(db, zTableName, zDbName);
003657    if( !pTab || pTab->pSelect ){
003658      pTab = 0;
003659      goto error_out;
003660    }
003661  
003662    /* Find the column for which info is requested */
003663    if( zColumnName==0 ){
003664      /* Query for existance of table only */
003665    }else{
003666      for(iCol=0; iCol<pTab->nCol; iCol++){
003667        pCol = &pTab->aCol[iCol];
003668        if( 0==sqlite3StrICmp(pCol->zName, zColumnName) ){
003669          break;
003670        }
003671      }
003672      if( iCol==pTab->nCol ){
003673        if( HasRowid(pTab) && sqlite3IsRowid(zColumnName) ){
003674          iCol = pTab->iPKey;
003675          pCol = iCol>=0 ? &pTab->aCol[iCol] : 0;
003676        }else{
003677          pTab = 0;
003678          goto error_out;
003679        }
003680      }
003681    }
003682  
003683    /* The following block stores the meta information that will be returned
003684    ** to the caller in local variables zDataType, zCollSeq, notnull, primarykey
003685    ** and autoinc. At this point there are two possibilities:
003686    ** 
003687    **     1. The specified column name was rowid", "oid" or "_rowid_" 
003688    **        and there is no explicitly declared IPK column. 
003689    **
003690    **     2. The table is not a view and the column name identified an 
003691    **        explicitly declared column. Copy meta information from *pCol.
003692    */ 
003693    if( pCol ){
003694      zDataType = sqlite3ColumnType(pCol,0);
003695      zCollSeq = pCol->zColl;
003696      notnull = pCol->notNull!=0;
003697      primarykey  = (pCol->colFlags & COLFLAG_PRIMKEY)!=0;
003698      autoinc = pTab->iPKey==iCol && (pTab->tabFlags & TF_Autoincrement)!=0;
003699    }else{
003700      zDataType = "INTEGER";
003701      primarykey = 1;
003702    }
003703    if( !zCollSeq ){
003704      zCollSeq = sqlite3StrBINARY;
003705    }
003706  
003707  error_out:
003708    sqlite3BtreeLeaveAll(db);
003709  
003710    /* Whether the function call succeeded or failed, set the output parameters
003711    ** to whatever their local counterparts contain. If an error did occur,
003712    ** this has the effect of zeroing all output parameters.
003713    */
003714    if( pzDataType ) *pzDataType = zDataType;
003715    if( pzCollSeq ) *pzCollSeq = zCollSeq;
003716    if( pNotNull ) *pNotNull = notnull;
003717    if( pPrimaryKey ) *pPrimaryKey = primarykey;
003718    if( pAutoinc ) *pAutoinc = autoinc;
003719  
003720    if( SQLITE_OK==rc && !pTab ){
003721      sqlite3DbFree(db, zErrMsg);
003722      zErrMsg = sqlite3MPrintf(db, "no such table column: %s.%s", zTableName,
003723          zColumnName);
003724      rc = SQLITE_ERROR;
003725    }
003726    sqlite3ErrorWithMsg(db, rc, (zErrMsg?"%s":0), zErrMsg);
003727    sqlite3DbFree(db, zErrMsg);
003728    rc = sqlite3ApiExit(db, rc);
003729    sqlite3_mutex_leave(db->mutex);
003730    return rc;
003731  }
003732  
003733  /*
003734  ** Sleep for a little while.  Return the amount of time slept.
003735  */
003736  int sqlite3_sleep(int ms){
003737    sqlite3_vfs *pVfs;
003738    int rc;
003739    pVfs = sqlite3_vfs_find(0);
003740    if( pVfs==0 ) return 0;
003741  
003742    /* This function works in milliseconds, but the underlying OsSleep() 
003743    ** API uses microseconds. Hence the 1000's.
003744    */
003745    rc = (sqlite3OsSleep(pVfs, 1000*ms)/1000);
003746    return rc;
003747  }
003748  
003749  /*
003750  ** Enable or disable the extended result codes.
003751  */
003752  int sqlite3_extended_result_codes(sqlite3 *db, int onoff){
003753  #ifdef SQLITE_ENABLE_API_ARMOR
003754    if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
003755  #endif
003756    sqlite3_mutex_enter(db->mutex);
003757    db->errMask = onoff ? 0xffffffff : 0xff;
003758    sqlite3_mutex_leave(db->mutex);
003759    return SQLITE_OK;
003760  }
003761  
003762  /*
003763  ** Invoke the xFileControl method on a particular database.
003764  */
003765  int sqlite3_file_control(sqlite3 *db, const char *zDbName, int op, void *pArg){
003766    int rc = SQLITE_ERROR;
003767    Btree *pBtree;
003768  
003769  #ifdef SQLITE_ENABLE_API_ARMOR
003770    if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
003771  #endif
003772    sqlite3_mutex_enter(db->mutex);
003773    pBtree = sqlite3DbNameToBtree(db, zDbName);
003774    if( pBtree ){
003775      Pager *pPager;
003776      sqlite3_file *fd;
003777      sqlite3BtreeEnter(pBtree);
003778      pPager = sqlite3BtreePager(pBtree);
003779      assert( pPager!=0 );
003780      fd = sqlite3PagerFile(pPager);
003781      assert( fd!=0 );
003782      if( op==SQLITE_FCNTL_FILE_POINTER ){
003783        *(sqlite3_file**)pArg = fd;
003784        rc = SQLITE_OK;
003785      }else if( op==SQLITE_FCNTL_VFS_POINTER ){
003786        *(sqlite3_vfs**)pArg = sqlite3PagerVfs(pPager);
003787        rc = SQLITE_OK;
003788      }else if( op==SQLITE_FCNTL_JOURNAL_POINTER ){
003789        *(sqlite3_file**)pArg = sqlite3PagerJrnlFile(pPager);
003790        rc = SQLITE_OK;
003791      }else if( op==SQLITE_FCNTL_DATA_VERSION ){
003792        *(unsigned int*)pArg = sqlite3PagerDataVersion(pPager);
003793        rc = SQLITE_OK;
003794      }else{
003795        rc = sqlite3OsFileControl(fd, op, pArg);
003796      }
003797      sqlite3BtreeLeave(pBtree);
003798    }
003799    sqlite3_mutex_leave(db->mutex);
003800    return rc;
003801  }
003802  
003803  /*
003804  ** Interface to the testing logic.
003805  */
003806  int sqlite3_test_control(int op, ...){
003807    int rc = 0;
003808  #ifdef SQLITE_UNTESTABLE
003809    UNUSED_PARAMETER(op);
003810  #else
003811    va_list ap;
003812    va_start(ap, op);
003813    switch( op ){
003814  
003815      /*
003816      ** Save the current state of the PRNG.
003817      */
003818      case SQLITE_TESTCTRL_PRNG_SAVE: {
003819        sqlite3PrngSaveState();
003820        break;
003821      }
003822  
003823      /*
003824      ** Restore the state of the PRNG to the last state saved using
003825      ** PRNG_SAVE.  If PRNG_SAVE has never before been called, then
003826      ** this verb acts like PRNG_RESET.
003827      */
003828      case SQLITE_TESTCTRL_PRNG_RESTORE: {
003829        sqlite3PrngRestoreState();
003830        break;
003831      }
003832  
003833      /*  sqlite3_test_control(SQLITE_TESTCTRL_PRNG_SEED, int x, sqlite3 *db);
003834      **
003835      ** Control the seed for the pseudo-random number generator (PRNG) that
003836      ** is built into SQLite.  Cases:
003837      **
003838      **    x!=0 && db!=0       Seed the PRNG to the current value of the
003839      **                        schema cookie in the main database for db, or
003840      **                        x if the schema cookie is zero.  This case
003841      **                        is convenient to use with database fuzzers
003842      **                        as it allows the fuzzer some control over the
003843      **                        the PRNG seed.
003844      **
003845      **    x!=0 && db==0       Seed the PRNG to the value of x.
003846      **
003847      **    x==0 && db==0       Revert to default behavior of using the
003848      **                        xRandomness method on the primary VFS.
003849      **
003850      ** This test-control also resets the PRNG so that the new seed will
003851      ** be used for the next call to sqlite3_randomness().
003852      */
003853      case SQLITE_TESTCTRL_PRNG_SEED: {
003854        int x = va_arg(ap, int);
003855        int y;
003856        sqlite3 *db = va_arg(ap, sqlite3*);
003857        assert( db==0 || db->aDb[0].pSchema!=0 );
003858        if( db && (y = db->aDb[0].pSchema->schema_cookie)!=0 ){ x = y; }
003859        sqlite3Config.iPrngSeed = x;
003860        sqlite3_randomness(0,0);
003861        break;
003862      }
003863  
003864      /*
003865      **  sqlite3_test_control(BITVEC_TEST, size, program)
003866      **
003867      ** Run a test against a Bitvec object of size.  The program argument
003868      ** is an array of integers that defines the test.  Return -1 on a
003869      ** memory allocation error, 0 on success, or non-zero for an error.
003870      ** See the sqlite3BitvecBuiltinTest() for additional information.
003871      */
003872      case SQLITE_TESTCTRL_BITVEC_TEST: {
003873        int sz = va_arg(ap, int);
003874        int *aProg = va_arg(ap, int*);
003875        rc = sqlite3BitvecBuiltinTest(sz, aProg);
003876        break;
003877      }
003878  
003879      /*
003880      **  sqlite3_test_control(FAULT_INSTALL, xCallback)
003881      **
003882      ** Arrange to invoke xCallback() whenever sqlite3FaultSim() is called,
003883      ** if xCallback is not NULL.
003884      **
003885      ** As a test of the fault simulator mechanism itself, sqlite3FaultSim(0)
003886      ** is called immediately after installing the new callback and the return
003887      ** value from sqlite3FaultSim(0) becomes the return from
003888      ** sqlite3_test_control().
003889      */
003890      case SQLITE_TESTCTRL_FAULT_INSTALL: {
003891        /* MSVC is picky about pulling func ptrs from va lists.
003892        ** http://support.microsoft.com/kb/47961
003893        ** sqlite3GlobalConfig.xTestCallback = va_arg(ap, int(*)(int));
003894        */
003895        typedef int(*TESTCALLBACKFUNC_t)(int);
003896        sqlite3GlobalConfig.xTestCallback = va_arg(ap, TESTCALLBACKFUNC_t);
003897        rc = sqlite3FaultSim(0);
003898        break;
003899      }
003900  
003901      /*
003902      **  sqlite3_test_control(BENIGN_MALLOC_HOOKS, xBegin, xEnd)
003903      **
003904      ** Register hooks to call to indicate which malloc() failures 
003905      ** are benign.
003906      */
003907      case SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS: {
003908        typedef void (*void_function)(void);
003909        void_function xBenignBegin;
003910        void_function xBenignEnd;
003911        xBenignBegin = va_arg(ap, void_function);
003912        xBenignEnd = va_arg(ap, void_function);
003913        sqlite3BenignMallocHooks(xBenignBegin, xBenignEnd);
003914        break;
003915      }
003916  
003917      /*
003918      **  sqlite3_test_control(SQLITE_TESTCTRL_PENDING_BYTE, unsigned int X)
003919      **
003920      ** Set the PENDING byte to the value in the argument, if X>0.
003921      ** Make no changes if X==0.  Return the value of the pending byte
003922      ** as it existing before this routine was called.
003923      **
003924      ** IMPORTANT:  Changing the PENDING byte from 0x40000000 results in
003925      ** an incompatible database file format.  Changing the PENDING byte
003926      ** while any database connection is open results in undefined and
003927      ** deleterious behavior.
003928      */
003929      case SQLITE_TESTCTRL_PENDING_BYTE: {
003930        rc = PENDING_BYTE;
003931  #ifndef SQLITE_OMIT_WSD
003932        {
003933          unsigned int newVal = va_arg(ap, unsigned int);
003934          if( newVal ) sqlite3PendingByte = newVal;
003935        }
003936  #endif
003937        break;
003938      }
003939  
003940      /*
003941      **  sqlite3_test_control(SQLITE_TESTCTRL_ASSERT, int X)
003942      **
003943      ** This action provides a run-time test to see whether or not
003944      ** assert() was enabled at compile-time.  If X is true and assert()
003945      ** is enabled, then the return value is true.  If X is true and
003946      ** assert() is disabled, then the return value is zero.  If X is
003947      ** false and assert() is enabled, then the assertion fires and the
003948      ** process aborts.  If X is false and assert() is disabled, then the
003949      ** return value is zero.
003950      */
003951      case SQLITE_TESTCTRL_ASSERT: {
003952        volatile int x = 0;
003953        assert( /*side-effects-ok*/ (x = va_arg(ap,int))!=0 );
003954        rc = x;
003955        break;
003956      }
003957  
003958  
003959      /*
003960      **  sqlite3_test_control(SQLITE_TESTCTRL_ALWAYS, int X)
003961      **
003962      ** This action provides a run-time test to see how the ALWAYS and
003963      ** NEVER macros were defined at compile-time.
003964      **
003965      ** The return value is ALWAYS(X) if X is true, or 0 if X is false.
003966      **
003967      ** The recommended test is X==2.  If the return value is 2, that means
003968      ** ALWAYS() and NEVER() are both no-op pass-through macros, which is the
003969      ** default setting.  If the return value is 1, then ALWAYS() is either
003970      ** hard-coded to true or else it asserts if its argument is false.
003971      ** The first behavior (hard-coded to true) is the case if
003972      ** SQLITE_TESTCTRL_ASSERT shows that assert() is disabled and the second
003973      ** behavior (assert if the argument to ALWAYS() is false) is the case if
003974      ** SQLITE_TESTCTRL_ASSERT shows that assert() is enabled.
003975      **
003976      ** The run-time test procedure might look something like this:
003977      **
003978      **    if( sqlite3_test_control(SQLITE_TESTCTRL_ALWAYS, 2)==2 ){
003979      **      // ALWAYS() and NEVER() are no-op pass-through macros
003980      **    }else if( sqlite3_test_control(SQLITE_TESTCTRL_ASSERT, 1) ){
003981      **      // ALWAYS(x) asserts that x is true. NEVER(x) asserts x is false.
003982      **    }else{
003983      **      // ALWAYS(x) is a constant 1.  NEVER(x) is a constant 0.
003984      **    }
003985      */
003986      case SQLITE_TESTCTRL_ALWAYS: {
003987        int x = va_arg(ap,int);
003988        rc = x ? ALWAYS(x) : 0;
003989        break;
003990      }
003991  
003992      /*
003993      **   sqlite3_test_control(SQLITE_TESTCTRL_BYTEORDER);
003994      **
003995      ** The integer returned reveals the byte-order of the computer on which
003996      ** SQLite is running:
003997      **
003998      **       1     big-endian,    determined at run-time
003999      **      10     little-endian, determined at run-time
004000      **  432101     big-endian,    determined at compile-time
004001      **  123410     little-endian, determined at compile-time
004002      */ 
004003      case SQLITE_TESTCTRL_BYTEORDER: {
004004        rc = SQLITE_BYTEORDER*100 + SQLITE_LITTLEENDIAN*10 + SQLITE_BIGENDIAN;
004005        break;
004006      }
004007  
004008      /*   sqlite3_test_control(SQLITE_TESTCTRL_RESERVE, sqlite3 *db, int N)
004009      **
004010      ** Set the nReserve size to N for the main database on the database
004011      ** connection db.
004012      */
004013      case SQLITE_TESTCTRL_RESERVE: {
004014        sqlite3 *db = va_arg(ap, sqlite3*);
004015        int x = va_arg(ap,int);
004016        sqlite3_mutex_enter(db->mutex);
004017        sqlite3BtreeSetPageSize(db->aDb[0].pBt, 0, x, 0);
004018        sqlite3_mutex_leave(db->mutex);
004019        break;
004020      }
004021  
004022      /*  sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS, sqlite3 *db, int N)
004023      **
004024      ** Enable or disable various optimizations for testing purposes.  The 
004025      ** argument N is a bitmask of optimizations to be disabled.  For normal
004026      ** operation N should be 0.  The idea is that a test program (like the
004027      ** SQL Logic Test or SLT test module) can run the same SQL multiple times
004028      ** with various optimizations disabled to verify that the same answer
004029      ** is obtained in every case.
004030      */
004031      case SQLITE_TESTCTRL_OPTIMIZATIONS: {
004032        sqlite3 *db = va_arg(ap, sqlite3*);
004033        db->dbOptFlags = (u16)(va_arg(ap, int) & 0xffff);
004034        break;
004035      }
004036  
004037      /*   sqlite3_test_control(SQLITE_TESTCTRL_LOCALTIME_FAULT, int onoff);
004038      **
004039      ** If parameter onoff is non-zero, subsequent calls to localtime()
004040      ** and its variants fail. If onoff is zero, undo this setting.
004041      */
004042      case SQLITE_TESTCTRL_LOCALTIME_FAULT: {
004043        sqlite3GlobalConfig.bLocaltimeFault = va_arg(ap, int);
004044        break;
004045      }
004046  
004047      /*   sqlite3_test_control(SQLITE_TESTCTRL_INTERNAL_FUNCS, int onoff);
004048      **
004049      ** If parameter onoff is non-zero, internal-use-only SQL functions
004050      ** are visible to ordinary SQL.  This is useful for testing but is
004051      ** unsafe because invalid parameters to those internal-use-only functions
004052      ** can result in crashes or segfaults.
004053      */
004054      case SQLITE_TESTCTRL_INTERNAL_FUNCTIONS: {
004055        sqlite3GlobalConfig.bInternalFunctions = va_arg(ap, int);
004056        break;
004057      }
004058  
004059      /*   sqlite3_test_control(SQLITE_TESTCTRL_NEVER_CORRUPT, int);
004060      **
004061      ** Set or clear a flag that indicates that the database file is always well-
004062      ** formed and never corrupt.  This flag is clear by default, indicating that
004063      ** database files might have arbitrary corruption.  Setting the flag during
004064      ** testing causes certain assert() statements in the code to be activated
004065      ** that demonstrat invariants on well-formed database files.
004066      */
004067      case SQLITE_TESTCTRL_NEVER_CORRUPT: {
004068        sqlite3GlobalConfig.neverCorrupt = va_arg(ap, int);
004069        break;
004070      }
004071  
004072      /*   sqlite3_test_control(SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS, int);
004073      **
004074      ** Set or clear a flag that causes SQLite to verify that type, name,
004075      ** and tbl_name fields of the sqlite_master table.  This is normally
004076      ** on, but it is sometimes useful to turn it off for testing.
004077      */
004078      case SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS: {
004079        sqlite3GlobalConfig.bExtraSchemaChecks = va_arg(ap, int);
004080        break;
004081      }
004082  
004083      /* Set the threshold at which OP_Once counters reset back to zero.
004084      ** By default this is 0x7ffffffe (over 2 billion), but that value is
004085      ** too big to test in a reasonable amount of time, so this control is
004086      ** provided to set a small and easily reachable reset value.
004087      */
004088      case SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD: {
004089        sqlite3GlobalConfig.iOnceResetThreshold = va_arg(ap, int);
004090        break;
004091      }
004092  
004093      /*   sqlite3_test_control(SQLITE_TESTCTRL_VDBE_COVERAGE, xCallback, ptr);
004094      **
004095      ** Set the VDBE coverage callback function to xCallback with context 
004096      ** pointer ptr.
004097      */
004098      case SQLITE_TESTCTRL_VDBE_COVERAGE: {
004099  #ifdef SQLITE_VDBE_COVERAGE
004100        typedef void (*branch_callback)(void*,unsigned int,
004101                                        unsigned char,unsigned char);
004102        sqlite3GlobalConfig.xVdbeBranch = va_arg(ap,branch_callback);
004103        sqlite3GlobalConfig.pVdbeBranchArg = va_arg(ap,void*);
004104  #endif
004105        break;
004106      }
004107  
004108      /*   sqlite3_test_control(SQLITE_TESTCTRL_SORTER_MMAP, db, nMax); */
004109      case SQLITE_TESTCTRL_SORTER_MMAP: {
004110        sqlite3 *db = va_arg(ap, sqlite3*);
004111        db->nMaxSorterMmap = va_arg(ap, int);
004112        break;
004113      }
004114  
004115      /*   sqlite3_test_control(SQLITE_TESTCTRL_ISINIT);
004116      **
004117      ** Return SQLITE_OK if SQLite has been initialized and SQLITE_ERROR if
004118      ** not.
004119      */
004120      case SQLITE_TESTCTRL_ISINIT: {
004121        if( sqlite3GlobalConfig.isInit==0 ) rc = SQLITE_ERROR;
004122        break;
004123      }
004124  
004125      /*  sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, db, dbName, onOff, tnum);
004126      **
004127      ** This test control is used to create imposter tables.  "db" is a pointer
004128      ** to the database connection.  dbName is the database name (ex: "main" or
004129      ** "temp") which will receive the imposter.  "onOff" turns imposter mode on
004130      ** or off.  "tnum" is the root page of the b-tree to which the imposter
004131      ** table should connect.
004132      **
004133      ** Enable imposter mode only when the schema has already been parsed.  Then
004134      ** run a single CREATE TABLE statement to construct the imposter table in
004135      ** the parsed schema.  Then turn imposter mode back off again.
004136      **
004137      ** If onOff==0 and tnum>0 then reset the schema for all databases, causing
004138      ** the schema to be reparsed the next time it is needed.  This has the
004139      ** effect of erasing all imposter tables.
004140      */
004141      case SQLITE_TESTCTRL_IMPOSTER: {
004142        sqlite3 *db = va_arg(ap, sqlite3*);
004143        sqlite3_mutex_enter(db->mutex);
004144        db->init.iDb = sqlite3FindDbName(db, va_arg(ap,const char*));
004145        db->init.busy = db->init.imposterTable = va_arg(ap,int);
004146        db->init.newTnum = va_arg(ap,int);
004147        if( db->init.busy==0 && db->init.newTnum>0 ){
004148          sqlite3ResetAllSchemasOfConnection(db);
004149        }
004150        sqlite3_mutex_leave(db->mutex);
004151        break;
004152      }
004153  
004154  #if defined(YYCOVERAGE)
004155      /*  sqlite3_test_control(SQLITE_TESTCTRL_PARSER_COVERAGE, FILE *out)
004156      **
004157      ** This test control (only available when SQLite is compiled with
004158      ** -DYYCOVERAGE) writes a report onto "out" that shows all
004159      ** state/lookahead combinations in the parser state machine
004160      ** which are never exercised.  If any state is missed, make the
004161      ** return code SQLITE_ERROR.
004162      */
004163      case SQLITE_TESTCTRL_PARSER_COVERAGE: {
004164        FILE *out = va_arg(ap, FILE*);
004165        if( sqlite3ParserCoverage(out) ) rc = SQLITE_ERROR;
004166        break;
004167      }
004168  #endif /* defined(YYCOVERAGE) */
004169  
004170      /*  sqlite3_test_control(SQLITE_TESTCTRL_RESULT_INTREAL, sqlite3_context*);
004171      **
004172      ** This test-control causes the most recent sqlite3_result_int64() value
004173      ** to be interpreted as a MEM_IntReal instead of as an MEM_Int.  Normally,
004174      ** MEM_IntReal values only arise during an INSERT operation of integer
004175      ** values into a REAL column, so they can be challenging to test.  This
004176      ** test-control enables us to write an intreal() SQL function that can
004177      ** inject an intreal() value at arbitrary places in an SQL statement,
004178      ** for testing purposes.
004179      */
004180      case SQLITE_TESTCTRL_RESULT_INTREAL: {
004181        sqlite3_context *pCtx = va_arg(ap, sqlite3_context*);
004182        sqlite3ResultIntReal(pCtx);
004183        break;
004184      }
004185    }
004186    va_end(ap);
004187  #endif /* SQLITE_UNTESTABLE */
004188    return rc;
004189  }
004190  
004191  #ifdef SQLITE_DEBUG
004192  /*
004193  ** This routine appears inside assert() statements only.
004194  **
004195  ** Return the number of URI parameters that follow the filename.
004196  */
004197  int sqlite3UriCount(const char *z){
004198    int n = 0;
004199    if( z==0 ) return 0;
004200    z += strlen(z)+1;
004201    while( z[0] ){
004202      z += strlen(z)+1;
004203      z += strlen(z)+1;
004204      n++;
004205    }
004206    return n;
004207  }
004208  #endif /* SQLITE_DEBUG */
004209  
004210  /*
004211  ** This is a utility routine, useful to VFS implementations, that checks
004212  ** to see if a database file was a URI that contained a specific query 
004213  ** parameter, and if so obtains the value of the query parameter.
004214  **
004215  ** The zFilename argument is the filename pointer passed into the xOpen()
004216  ** method of a VFS implementation.  The zParam argument is the name of the
004217  ** query parameter we seek.  This routine returns the value of the zParam
004218  ** parameter if it exists.  If the parameter does not exist, this routine
004219  ** returns a NULL pointer.
004220  */
004221  const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam){
004222    if( zFilename==0 || zParam==0 ) return 0;
004223    zFilename += sqlite3Strlen30(zFilename) + 1;
004224    while( zFilename[0] ){
004225      int x = strcmp(zFilename, zParam);
004226      zFilename += sqlite3Strlen30(zFilename) + 1;
004227      if( x==0 ) return zFilename;
004228      zFilename += sqlite3Strlen30(zFilename) + 1;
004229    }
004230    return 0;
004231  }
004232  
004233  /*
004234  ** Return a boolean value for a query parameter.
004235  */
004236  int sqlite3_uri_boolean(const char *zFilename, const char *zParam, int bDflt){
004237    const char *z = sqlite3_uri_parameter(zFilename, zParam);
004238    bDflt = bDflt!=0;
004239    return z ? sqlite3GetBoolean(z, bDflt) : bDflt;
004240  }
004241  
004242  /*
004243  ** Return a 64-bit integer value for a query parameter.
004244  */
004245  sqlite3_int64 sqlite3_uri_int64(
004246    const char *zFilename,    /* Filename as passed to xOpen */
004247    const char *zParam,       /* URI parameter sought */
004248    sqlite3_int64 bDflt       /* return if parameter is missing */
004249  ){
004250    const char *z = sqlite3_uri_parameter(zFilename, zParam);
004251    sqlite3_int64 v;
004252    if( z && sqlite3DecOrHexToI64(z, &v)==0 ){
004253      bDflt = v;
004254    }
004255    return bDflt;
004256  }
004257  
004258  /*
004259  ** Return the Btree pointer identified by zDbName.  Return NULL if not found.
004260  */
004261  Btree *sqlite3DbNameToBtree(sqlite3 *db, const char *zDbName){
004262    int iDb = zDbName ? sqlite3FindDbName(db, zDbName) : 0;
004263    return iDb<0 ? 0 : db->aDb[iDb].pBt;
004264  }
004265  
004266  /*
004267  ** Return the filename of the database associated with a database
004268  ** connection.
004269  */
004270  const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName){
004271    Btree *pBt;
004272  #ifdef SQLITE_ENABLE_API_ARMOR
004273    if( !sqlite3SafetyCheckOk(db) ){
004274      (void)SQLITE_MISUSE_BKPT;
004275      return 0;
004276    }
004277  #endif
004278    pBt = sqlite3DbNameToBtree(db, zDbName);
004279    return pBt ? sqlite3BtreeGetFilename(pBt) : 0;
004280  }
004281  
004282  /*
004283  ** Return 1 if database is read-only or 0 if read/write.  Return -1 if
004284  ** no such database exists.
004285  */
004286  int sqlite3_db_readonly(sqlite3 *db, const char *zDbName){
004287    Btree *pBt;
004288  #ifdef SQLITE_ENABLE_API_ARMOR
004289    if( !sqlite3SafetyCheckOk(db) ){
004290      (void)SQLITE_MISUSE_BKPT;
004291      return -1;
004292    }
004293  #endif
004294    pBt = sqlite3DbNameToBtree(db, zDbName);
004295    return pBt ? sqlite3BtreeIsReadonly(pBt) : -1;
004296  }
004297  
004298  #ifdef SQLITE_ENABLE_SNAPSHOT
004299  /*
004300  ** Obtain a snapshot handle for the snapshot of database zDb currently 
004301  ** being read by handle db.
004302  */
004303  int sqlite3_snapshot_get(
004304    sqlite3 *db, 
004305    const char *zDb,
004306    sqlite3_snapshot **ppSnapshot
004307  ){
004308    int rc = SQLITE_ERROR;
004309  #ifndef SQLITE_OMIT_WAL
004310  
004311  #ifdef SQLITE_ENABLE_API_ARMOR
004312    if( !sqlite3SafetyCheckOk(db) ){
004313      return SQLITE_MISUSE_BKPT;
004314    }
004315  #endif
004316    sqlite3_mutex_enter(db->mutex);
004317  
004318    if( db->autoCommit==0 ){
004319      int iDb = sqlite3FindDbName(db, zDb);
004320      if( iDb==0 || iDb>1 ){
004321        Btree *pBt = db->aDb[iDb].pBt;
004322        if( 0==sqlite3BtreeIsInTrans(pBt) ){
004323          rc = sqlite3BtreeBeginTrans(pBt, 0, 0);
004324          if( rc==SQLITE_OK ){
004325            rc = sqlite3PagerSnapshotGet(sqlite3BtreePager(pBt), ppSnapshot);
004326          }
004327        }
004328      }
004329    }
004330  
004331    sqlite3_mutex_leave(db->mutex);
004332  #endif   /* SQLITE_OMIT_WAL */
004333    return rc;
004334  }
004335  
004336  /*
004337  ** Open a read-transaction on the snapshot idendified by pSnapshot.
004338  */
004339  int sqlite3_snapshot_open(
004340    sqlite3 *db, 
004341    const char *zDb, 
004342    sqlite3_snapshot *pSnapshot
004343  ){
004344    int rc = SQLITE_ERROR;
004345  #ifndef SQLITE_OMIT_WAL
004346  
004347  #ifdef SQLITE_ENABLE_API_ARMOR
004348    if( !sqlite3SafetyCheckOk(db) ){
004349      return SQLITE_MISUSE_BKPT;
004350    }
004351  #endif
004352    sqlite3_mutex_enter(db->mutex);
004353    if( db->autoCommit==0 ){
004354      int iDb;
004355      iDb = sqlite3FindDbName(db, zDb);
004356      if( iDb==0 || iDb>1 ){
004357        Btree *pBt = db->aDb[iDb].pBt;
004358        if( sqlite3BtreeIsInTrans(pBt)==0 ){
004359          Pager *pPager = sqlite3BtreePager(pBt);
004360          int bUnlock = 0;
004361          if( sqlite3BtreeIsInReadTrans(pBt) ){
004362            if( db->nVdbeActive==0 ){
004363              rc = sqlite3PagerSnapshotCheck(pPager, pSnapshot);
004364              if( rc==SQLITE_OK ){
004365                bUnlock = 1;
004366                rc = sqlite3BtreeCommit(pBt);
004367              }
004368            }
004369          }else{
004370            rc = SQLITE_OK;
004371          }
004372          if( rc==SQLITE_OK ){
004373            rc = sqlite3PagerSnapshotOpen(pPager, pSnapshot);
004374          }
004375          if( rc==SQLITE_OK ){
004376            rc = sqlite3BtreeBeginTrans(pBt, 0, 0);
004377            sqlite3PagerSnapshotOpen(pPager, 0);
004378          }
004379          if( bUnlock ){
004380            sqlite3PagerSnapshotUnlock(pPager);
004381          }
004382        }
004383      }
004384    }
004385  
004386    sqlite3_mutex_leave(db->mutex);
004387  #endif   /* SQLITE_OMIT_WAL */
004388    return rc;
004389  }
004390  
004391  /*
004392  ** Recover as many snapshots as possible from the wal file associated with
004393  ** schema zDb of database db.
004394  */
004395  int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb){
004396    int rc = SQLITE_ERROR;
004397    int iDb;
004398  #ifndef SQLITE_OMIT_WAL
004399  
004400  #ifdef SQLITE_ENABLE_API_ARMOR
004401    if( !sqlite3SafetyCheckOk(db) ){
004402      return SQLITE_MISUSE_BKPT;
004403    }
004404  #endif
004405  
004406    sqlite3_mutex_enter(db->mutex);
004407    iDb = sqlite3FindDbName(db, zDb);
004408    if( iDb==0 || iDb>1 ){
004409      Btree *pBt = db->aDb[iDb].pBt;
004410      if( 0==sqlite3BtreeIsInReadTrans(pBt) ){
004411        rc = sqlite3BtreeBeginTrans(pBt, 0, 0);
004412        if( rc==SQLITE_OK ){
004413          rc = sqlite3PagerSnapshotRecover(sqlite3BtreePager(pBt));
004414          sqlite3BtreeCommit(pBt);
004415        }
004416      }
004417    }
004418    sqlite3_mutex_leave(db->mutex);
004419  #endif   /* SQLITE_OMIT_WAL */
004420    return rc;
004421  }
004422  
004423  /*
004424  ** Free a snapshot handle obtained from sqlite3_snapshot_get().
004425  */
004426  void sqlite3_snapshot_free(sqlite3_snapshot *pSnapshot){
004427    sqlite3_free(pSnapshot);
004428  }
004429  #endif /* SQLITE_ENABLE_SNAPSHOT */
004430  
004431  #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
004432  /*
004433  ** Given the name of a compile-time option, return true if that option
004434  ** was used and false if not.
004435  **
004436  ** The name can optionally begin with "SQLITE_" but the "SQLITE_" prefix
004437  ** is not required for a match.
004438  */
004439  int sqlite3_compileoption_used(const char *zOptName){
004440    int i, n;
004441    int nOpt;
004442    const char **azCompileOpt;
004443   
004444  #if SQLITE_ENABLE_API_ARMOR
004445    if( zOptName==0 ){
004446      (void)SQLITE_MISUSE_BKPT;
004447      return 0;
004448    }
004449  #endif
004450  
004451    azCompileOpt = sqlite3CompileOptions(&nOpt);
004452  
004453    if( sqlite3StrNICmp(zOptName, "SQLITE_", 7)==0 ) zOptName += 7;
004454    n = sqlite3Strlen30(zOptName);
004455  
004456    /* Since nOpt is normally in single digits, a linear search is 
004457    ** adequate. No need for a binary search. */
004458    for(i=0; i<nOpt; i++){
004459      if( sqlite3StrNICmp(zOptName, azCompileOpt[i], n)==0
004460       && sqlite3IsIdChar((unsigned char)azCompileOpt[i][n])==0
004461      ){
004462        return 1;
004463      }
004464    }
004465    return 0;
004466  }
004467  
004468  /*
004469  ** Return the N-th compile-time option string.  If N is out of range,
004470  ** return a NULL pointer.
004471  */
004472  const char *sqlite3_compileoption_get(int N){
004473    int nOpt;
004474    const char **azCompileOpt;
004475    azCompileOpt = sqlite3CompileOptions(&nOpt);
004476    if( N>=0 && N<nOpt ){
004477      return azCompileOpt[N];
004478    }
004479    return 0;
004480  }
004481  #endif /* SQLITE_OMIT_COMPILEOPTION_DIAGS */