Fossil

  void *notUsed,
  int nKey1, const void *pKey1,
  int nKey2, const void *pKey2
){
  const unsigned char *zA = (const unsigned char*)pKey1;
  const unsigned char *zB = (const unsigned char*)pKey2;
  int i=0, j=0, x;
  (void)notUsed;
  while( i<nKey1 && j<nKey2 ){
    x = zA[i] - zB[j];
    if( isdigit(zA[i]) ){
      int k;
      if( !isdigit(zB[j]) ) return x;
      while( i<nKey1 && zA[i]=='0' ){ i++; }
      while( j<nKey2 && zB[j]=='0' ){ j++; }

        zEQP = sqlite3_mprintf("EXPLAIN QUERY PLAN %s", zStmtSql);
        rc = sqlite3_prepare_v2(db, zEQP, -1, &pExplain, 0);
        if( rc==SQLITE_OK ){
          while( sqlite3_step(pExplain)==SQLITE_ROW ){
            const char *zEQPLine = (const char*)sqlite3_column_text(pExplain,3);
            int iEqpId = sqlite3_column_int(pExplain, 0);
            int iParentId = sqlite3_column_int(pExplain, 1);
            if( zEQPLine==0 ) zEQPLine = "";
            if( zEQPLine[0]=='-' ) eqp_render(pArg);
            eqp_append(pArg, iEqpId, iParentId, zEQPLine);
          }
          eqp_render(pArg);
        }
        sqlite3_finalize(pExplain);
        sqlite3_free(zEQP);

  unsigned char aHdr[100];
  open_db(p, 0);
  if( p->db==0 ) return 1;
  rc = sqlite3_prepare_v2(p->db,
             "SELECT data FROM sqlite_dbpage(?1) WHERE pgno=1",
             -1, &pStmt, 0);
  if( rc ){




    utf8_printf(stderr, "error: %s\n", sqlite3_errmsg(p->db));

    sqlite3_finalize(pStmt);
    return 1;
  }
  sqlite3_bind_text(pStmt, 1, zDb, -1, SQLITE_STATIC);
  if( sqlite3_step(pStmt)==SQLITE_ROW
   && sqlite3_column_bytes(pStmt,0)>100
  ){

   || (c=='e' && n==5 && strcmp(azArg[0],"excel")==0)
  ){
    const char *zFile = 0;
    int bTxtMode = 0;
    int i;
    int eMode = 0;
    int bBOM = 0;
    int bOnce = 0;  /* 0: .output, 1: .once, 2: .excel */

    if( c=='e' ){
      eMode = 'x';
      bOnce = 2;
    }else if( strncmp(azArg[0],"once",n)==0 ){
      bOnce = 1;
    }

#endif
#if SQLITE_ENABLE_ATOMIC_WRITE
  "ENABLE_ATOMIC_WRITE",
#endif
#if SQLITE_ENABLE_BATCH_ATOMIC_WRITE
  "ENABLE_BATCH_ATOMIC_WRITE",
#endif
#if SQLITE_ENABLE_BYTECODE_VTAB
  "ENABLE_BYTECODE_VTAB",
#endif
#if SQLITE_ENABLE_CEROD
  "ENABLE_CEROD=" CTIMEOPT_VAL(SQLITE_ENABLE_CEROD),
#endif
#if SQLITE_ENABLE_COLUMN_METADATA
  "ENABLE_COLUMN_METADATA",
#endif
#if SQLITE_ENABLE_COLUMN_USED_MASK

#endif
#if SQLITE_OMIT_BETWEEN_OPTIMIZATION
  "OMIT_BETWEEN_OPTIMIZATION",
#endif
#if SQLITE_OMIT_BLOB_LITERAL
  "OMIT_BLOB_LITERAL",
#endif



#if SQLITE_OMIT_CAST
  "OMIT_CAST",
#endif
#if SQLITE_OMIT_CHECK
  "OMIT_CHECK",
#endif
#if SQLITE_OMIT_COMPLETE

**
** See also: [sqlite3_libversion()],
** [sqlite3_libversion_number()], [sqlite3_sourceid()],
** [sqlite_version()] and [sqlite_source_id()].
*/
#define SQLITE_VERSION        "3.32.0"
#define SQLITE_VERSION_NUMBER 3032000
#define SQLITE_SOURCE_ID      "2020-05-04 19:52:00 8eee591d3cb9fadfd5cac5543bd66ef9cb371a72d3ad3241fb3bfd67fb216eda"

/*
** CAPI3REF: Run-Time Library Version Numbers
** KEYWORDS: sqlite3_version sqlite3_sourceid
**
** These interfaces provide the same information as the [SQLITE_VERSION],
** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros

**
** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors
** for the [sqlite3] object.
** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if
** the [sqlite3] object is successfully destroyed and all associated
** resources are deallocated.
**
** Ideally, applications should [sqlite3_finalize | finalize] all
** [prepared statements], [sqlite3_blob_close | close] all [BLOB handles], and 
** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated
** with the [sqlite3] object prior to attempting to close the object.
** ^If the database connection is associated with unfinalized prepared
** statements, BLOB handlers, and/or unfinished sqlite3_backup objects then
** sqlite3_close() will leave the database connection open and return
** [SQLITE_BUSY]. ^If sqlite3_close_v2() is called with unfinalized prepared
** statements, unclosed BLOB handlers, and/or unfinished sqlite3_backups,
** it returns [SQLITE_OK] regardless, but instead of deallocating the database
** connection immediately, it marks the database connection as an unusable
** "zombie" and makes arrangements to automatically deallocate the database
** connection after all prepared statements are finalized, all BLOB handles
** are closed, and all backups have finished. The sqlite3_close_v2() interface
** is intended for use with host languages that are garbage collected, and
** where the order in which destructors are called is arbitrary.










**
** ^If an [sqlite3] object is destroyed while a transaction is open,
** the transaction is automatically rolled back.
**
** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)]
** must be either a NULL
** pointer or an [sqlite3] object pointer obtained

#define SQLITE_IOERR_GETTEMPPATH       (SQLITE_IOERR | (25<<8))
#define SQLITE_IOERR_CONVPATH          (SQLITE_IOERR | (26<<8))
#define SQLITE_IOERR_VNODE             (SQLITE_IOERR | (27<<8))
#define SQLITE_IOERR_AUTH              (SQLITE_IOERR | (28<<8))
#define SQLITE_IOERR_BEGIN_ATOMIC      (SQLITE_IOERR | (29<<8))
#define SQLITE_IOERR_COMMIT_ATOMIC     (SQLITE_IOERR | (30<<8))
#define SQLITE_IOERR_ROLLBACK_ATOMIC   (SQLITE_IOERR | (31<<8))
#define SQLITE_IOERR_DATA              (SQLITE_IOERR | (32<<8))
#define SQLITE_LOCKED_SHAREDCACHE      (SQLITE_LOCKED |  (1<<8))
#define SQLITE_LOCKED_VTAB             (SQLITE_LOCKED |  (2<<8))
#define SQLITE_BUSY_RECOVERY           (SQLITE_BUSY   |  (1<<8))
#define SQLITE_BUSY_SNAPSHOT           (SQLITE_BUSY   |  (2<<8))
#define SQLITE_CANTOPEN_NOTEMPDIR      (SQLITE_CANTOPEN | (1<<8))
#define SQLITE_CANTOPEN_ISDIR          (SQLITE_CANTOPEN | (2<<8))
#define SQLITE_CANTOPEN_FULLPATH       (SQLITE_CANTOPEN | (3<<8))

** omits changes made by other database connections.  The
** [PRAGMA data_version] command provides a mechanism to detect changes to
** a single attached database that occur due to other database connections,
** but omits changes implemented by the database connection on which it is
** called.  This file control is the only mechanism to detect changes that
** happen either internally or externally and that are associated with
** a particular attached database.
**
** <li>[[SQLITE_FCNTL_CKPT_START]]
** The [SQLITE_FCNTL_CKPT_START] opcode is invoked from within a checkpoint
** in wal mode before the client starts to copy pages from the wal
** file to the database file.
**
** <li>[[SQLITE_FCNTL_CKPT_DONE]]
** The [SQLITE_FCNTL_CKPT_DONE] opcode is invoked from within a checkpoint
** in wal mode after the client has finished copying pages from the wal
** file to the database file, but before the *-shm file is updated to
** record the fact that the pages have been checkpointed.
** </ul>

#define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE    32
#define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE  33
#define SQLITE_FCNTL_LOCK_TIMEOUT           34
#define SQLITE_FCNTL_DATA_VERSION           35
#define SQLITE_FCNTL_SIZE_LIMIT             36
#define SQLITE_FCNTL_CKPT_DONE              37
#define SQLITE_FCNTL_RESERVE_BYTES          38
#define SQLITE_FCNTL_CKPT_START             39

/* deprecated names */
#define SQLITE_GET_LOCKPROXYFILE      SQLITE_FCNTL_GET_LOCKPROXYFILE
#define SQLITE_SET_LOCKPROXYFILE      SQLITE_FCNTL_SET_LOCKPROXYFILE
#define SQLITE_LAST_ERRNO             SQLITE_FCNTL_LAST_ERRNO

/*
** CAPI3REF: Obtain Values For URI Parameters
**
** These are utility routines, useful to [VFS|custom VFS implementations],
** that check if a database file was a URI that contained a specific query 
** parameter, and if so obtains the value of that query parameter.
**
** The first parameter to these interfaces (hereafter referred to
** as F) must be one of:
** <ul>
** <li> A database filename pointer created by the SQLite core and
** passed into the xOpen() method of a VFS implemention, or
** <li> A filename obtained from [sqlite3_db_filename()], or
** <li> A new filename constructed using [sqlite3_create_filename()].
** </ul>
** If the F parameter is not one of the above, then the behavior is
** undefined and probably undesirable.  Older versions of SQLite were
** more tolerant of invalid F parameters than newer versions.
**
** If F is a suitable filename (as described in the previous paragraph)
** and if P is the name of the query parameter, then
** sqlite3_uri_parameter(F,P) returns the value of the P
** parameter if it exists or a NULL pointer if P does not appear as a 
** query parameter on F.  If P is a query parameter of F and it
** has no explicit value, then sqlite3_uri_parameter(F,P) returns
** a pointer to an empty string.
**

** return value from [sqlite3_db_filename()], then the result is
** undefined and is likely a memory access violation.
*/
SQLITE_API const char *sqlite3_filename_database(const char*);
SQLITE_API const char *sqlite3_filename_journal(const char*);
SQLITE_API const char *sqlite3_filename_wal(const char*);

/*
** CAPI3REF:  Database File Corresponding To A Journal
**
** ^If X is the name of a rollback or WAL-mode journal file that is
** passed into the xOpen method of [sqlite3_vfs], then 
** sqlite3_database_file_object(X) returns a pointer to the [sqlite3_file]
** object that represents the main database file.
**
** This routine is intended for use in custom [VFS] implementations
** only.  It is not a general-purpose interface.
** The argument sqlite3_file_object(X) must be a filename pointer that
** has been passed into [sqlite3_vfs].xOpen method where the 
** flags parameter to xOpen contains one of the bits
** [SQLITE_OPEN_MAIN_JOURNAL] or [SQLITE_OPEN_WAL].  Any other use
** of this routine results in undefined and probably undesirable
** behavior.
*/
SQLITE_API sqlite3_file *sqlite3_database_file_object(const char*);

/*
** CAPI3REF: Create and Destroy VFS Filenames
**
** These interfces are provided for use by [VFS shim] implementations and
** are not useful outside of that context.
**
** The sqlite3_create_filename(D,J,W,N,P) allocates memory to hold a version of

** pointer if N is zero.  None of the 2*N pointers in the P array may be
** NULL pointers and key pointers should not be empty strings.
** None of the D, J, or W parameters to sqlite3_create_filename(D,J,W,N,P) may
** be NULL pointers, though they can be empty strings.
**
** The sqlite3_free_filename(Y) routine releases a memory allocation
** previously obtained from sqlite3_create_filename().  Invoking
** sqlite3_free_filename(Y) where Y is a NULL pointer is a harmless no-op.
**
** If the Y parameter to sqlite3_free_filename(Y) is anything other
** than a NULL pointer or a pointer previously acquired from
** sqlite3_create_filename(), then bad things such as heap
** corruption or segfaults may occur. The value Y should be 
** used again after sqlite3_free_filename(Y) has been called.  This means
** that if the [sqlite3_vfs.xOpen()] method of a VFS has been called using Y,

SQLITE_PRIVATE int sqlite3HeaderSizeBtree(void);

#ifndef NDEBUG
SQLITE_PRIVATE int sqlite3BtreeCursorIsValid(BtCursor*);
#endif
SQLITE_PRIVATE int sqlite3BtreeCursorIsValidNN(BtCursor*);


SQLITE_PRIVATE int sqlite3BtreeCount(sqlite3*, BtCursor*, i64*);


#ifdef SQLITE_TEST
SQLITE_PRIVATE int sqlite3BtreeCursorInfo(BtCursor*, int*, int);
SQLITE_PRIVATE void sqlite3BtreeCursorList(Btree*);
#endif

#ifndef SQLITE_OMIT_WAL

typedef int (*RecordCompare)(int,const void*,UnpackedRecord*);
SQLITE_PRIVATE RecordCompare sqlite3VdbeFindCompare(UnpackedRecord*);

SQLITE_PRIVATE void sqlite3VdbeLinkSubProgram(Vdbe *, SubProgram *);
SQLITE_PRIVATE int sqlite3VdbeHasSubProgram(Vdbe*);

SQLITE_PRIVATE int sqlite3NotPureFunc(sqlite3_context*);
#ifdef SQLITE_ENABLE_BYTECODE_VTAB
SQLITE_PRIVATE int sqlite3VdbeBytecodeVtabInit(sqlite3*);
#endif

/* Use SQLITE_ENABLE_COMMENTS to enable generation of extra comments on
** each VDBE opcode.
**
** Use the SQLITE_ENABLE_MODULE_COMMENTS macro to see some extra no-op
** comments in VDBE programs that show key decision points in the code
** generator.

  VTable *pDisconnect;          /* Disconnect these in next sqlite3_prepare() */
#endif
  Hash aFunc;                   /* Hash table of connection functions */
  Hash aCollSeq;                /* All collating sequences */
  BusyHandler busyHandler;      /* Busy callback */
  Db aDbStatic[2];              /* Static space for the 2 default backends */
  Savepoint *pSavepoint;        /* List of active savepoints */
  int nAnalysisLimit;           /* Number of index rows to ANALYZE */
  int busyTimeout;              /* Busy handler timeout, in msec */
  int nSavepoint;               /* Number of non-transaction savepoints */
  int nStatement;               /* Number of nested statement-transactions  */
  i64 nDeferredCons;            /* Net deferred constraints this transaction. */
  i64 nDeferredImmCons;         /* Net deferred immediate constraints */
  int *pnBytesFreed;            /* If not NULL, increment this in DbFree() */
#ifdef SQLITE_ENABLE_UNLOCK_NOTIFY

#endif

/*
** VDBE_DISPLAY_P4 is true or false depending on whether or not the
** "explain" P4 display logic is enabled.
*/
#if !defined(SQLITE_OMIT_EXPLAIN) || !defined(NDEBUG) \
     || defined(VDBE_PROFILE) || defined(SQLITE_DEBUG) \
     || defined(SQLITE_ENABLE_BYTECODE_VTAB)
# define VDBE_DISPLAY_P4 1
#else
# define VDBE_DISPLAY_P4 0
#endif

/*
** SQL is translated into a sequence of instructions to be

SQLITE_PRIVATE u32 sqlite3VdbeSerialGet(const unsigned char*, u32, Mem*);
SQLITE_PRIVATE void sqlite3VdbeDeleteAuxData(sqlite3*, AuxData**, int, int);

int sqlite2BtreeKeyCompare(BtCursor *, const void *, int, int, int *);
SQLITE_PRIVATE int sqlite3VdbeIdxKeyCompare(sqlite3*,VdbeCursor*,UnpackedRecord*,int*);
SQLITE_PRIVATE int sqlite3VdbeIdxRowid(sqlite3*, BtCursor*, i64*);
SQLITE_PRIVATE int sqlite3VdbeExec(Vdbe*);
#if !defined(SQLITE_OMIT_EXPLAIN) || defined(SQLITE_ENABLE_BYTECODE_VTAB)
SQLITE_PRIVATE int sqlite3VdbeNextOpcode(Vdbe*,Mem*,int,int*,int*,Op**);
SQLITE_PRIVATE char *sqlite3VdbeDisplayP4(sqlite3*,Op*);
#endif
#if defined(SQLITE_ENABLE_EXPLAIN_COMMENTS)
SQLITE_PRIVATE char *sqlite3VdbeDisplayComment(sqlite3*,const Op*,const char*);
#endif
#if !defined(SQLITE_OMIT_EXPLAIN)
SQLITE_PRIVATE int sqlite3VdbeList(Vdbe*);
#endif
SQLITE_PRIVATE int sqlite3VdbeHalt(Vdbe*);
SQLITE_PRIVATE int sqlite3VdbeChangeEncoding(Mem *, int);
SQLITE_PRIVATE int sqlite3VdbeMemTooBig(Mem*);
SQLITE_PRIVATE int sqlite3VdbeMemCopy(Mem*, const Mem*);
SQLITE_PRIVATE void sqlite3VdbeMemShallowCopy(Mem*, const Mem*, int);

SQLITE_PRIVATE int sqlite3VdbeMemFromBtree(BtCursor*,u32,u32,Mem*);
SQLITE_PRIVATE int sqlite3VdbeMemFromBtreeZeroOffset(BtCursor*,u32,Mem*);
SQLITE_PRIVATE void sqlite3VdbeMemRelease(Mem *p);
SQLITE_PRIVATE int sqlite3VdbeMemFinalize(Mem*, FuncDef*);
#ifndef SQLITE_OMIT_WINDOWFUNC
SQLITE_PRIVATE int sqlite3VdbeMemAggValue(Mem*, Mem*, FuncDef*);
#endif
#if !defined(SQLITE_OMIT_EXPLAIN) || defined(SQLITE_ENABLE_BYTECODE_VTAB)
SQLITE_PRIVATE const char *sqlite3OpcodeName(int);
#endif
SQLITE_PRIVATE int sqlite3VdbeMemGrow(Mem *pMem, int n, int preserve);
SQLITE_PRIVATE int sqlite3VdbeMemClearAndResize(Mem *pMem, int n);
SQLITE_PRIVATE int sqlite3VdbeCloseStatement(Vdbe *, int);
#ifdef SQLITE_DEBUG
SQLITE_PRIVATE int sqlite3VdbeFrameIsValid(VdbeFrame*);

    return priorLimit;
  }
  if( mem0.hardLimit>0 && (n>mem0.hardLimit || n==0) ){
    n = mem0.hardLimit;
  }
  mem0.alarmThreshold = n;
  nUsed = sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED);
  AtomicStore(&mem0.nearlyFull, n>0 && n<=nUsed);
  sqlite3_mutex_leave(mem0.mutex);
  excess = sqlite3_memory_used() - n;
  if( excess>0 ) sqlite3_release_memory((int)(excess & 0x7fffffff));
  return priorLimit;
}
SQLITE_API void sqlite3_soft_heap_limit(int n){
  if( n<0 ) n = 0;

/*
** Return true if the heap is currently under memory pressure - in other
** words if the amount of heap used is close to the limit set by
** sqlite3_soft_heap_limit().
*/
SQLITE_PRIVATE int sqlite3HeapNearlyFull(void){
  return AtomicLoad(&mem0.nearlyFull);
}

/*
** Deinitialize the memory allocation subsystem.
*/
SQLITE_PRIVATE void sqlite3MallocEnd(void){
  if( sqlite3GlobalConfig.m.xShutdown ){

  ** following xRoundup() call. */
  nFull = sqlite3GlobalConfig.m.xRoundup(n);

  sqlite3StatusHighwater(SQLITE_STATUS_MALLOC_SIZE, n);
  if( mem0.alarmThreshold>0 ){
    sqlite3_int64 nUsed = sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED);
    if( nUsed >= mem0.alarmThreshold - nFull ){
      AtomicStore(&mem0.nearlyFull, 1);
      sqlite3MallocAlarm(nFull);
      if( mem0.hardLimit ){
        nUsed = sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED);
        if( nUsed >= mem0.hardLimit - nFull ){
          *pp = 0;
          return;
        }
      }
    }else{
      AtomicStore(&mem0.nearlyFull, 0);
    }
  }
  p = sqlite3GlobalConfig.m.xMalloc(nFull);
#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
  if( p==0 && mem0.alarmThreshold>0 ){
    sqlite3MallocAlarm(nFull);
    p = sqlite3GlobalConfig.m.xMalloc(nFull);

    if( rc!=SQLITE_OK ){
      goto delmaster_out;
    }
    if( exists ){
      /* One of the journals pointed to by the master journal exists.
      ** Open it and check if it points at the master journal. If
      ** so, return without deleting the master journal file.
      ** NB:  zJournal is really a MAIN_JOURNAL.  But call it a 
      ** MASTER_JOURNAL here so that the VFS will not send the zJournal
      ** name into sqlite3_database_file_object().
      */
      int c;
      int flags = (SQLITE_OPEN_READONLY|SQLITE_OPEN_MASTER_JOURNAL);
      rc = sqlite3OsOpen(pVfs, zJournal, pJournal, flags, 0);
      if( rc!=SQLITE_OK ){
        goto delmaster_out;
      }

      rc = readMasterJournal(pJournal, zMasterPtr, nMasterPtr);
      sqlite3OsClose(pJournal);

  ** file name. The layout in memory is as follows:
  **
  **     Pager object                    (sizeof(Pager) bytes)
  **     PCache object                   (sqlite3PcacheSize() bytes)
  **     Database file handle            (pVfs->szOsFile bytes)
  **     Sub-journal file handle         (journalFileSize bytes)
  **     Main journal file handle        (journalFileSize bytes)
  **     Ptr back to the Pager           (sizeof(Pager*) bytes)
  **     \0\0\0\0 database prefix        (4 bytes)
  **     Database file name              (nPathname+1 bytes)
  **     URI query parameters            (nUriByte bytes)
  **     Journal filename                (nPathname+8+1 bytes)
  **     WAL filename                    (nPathname+4+1 bytes)
  **     \0\0\0 terminator               (3 bytes)
  **

  ** changes here, be sure to change it there as well.
  */
  pPtr = (u8 *)sqlite3MallocZero(
    ROUND8(sizeof(*pPager)) +            /* Pager structure */
    ROUND8(pcacheSize) +                 /* PCache object */
    ROUND8(pVfs->szOsFile) +             /* The main db file */
    journalFileSize * 2 +                /* The two journal files */
    sizeof(pPager) +                     /* Space to hold a pointer */
    4 +                                  /* Database prefix */
    nPathname + 1 +                      /* database filename */
    nUriByte +                           /* query parameters */
    nPathname + 8 + 1 +                  /* Journal filename */
#ifndef SQLITE_OMIT_WAL
    nPathname + 4 + 1 +                  /* WAL filename */
#endif
    3                                    /* Terminator */
  );
  assert( EIGHT_BYTE_ALIGNMENT(SQLITE_INT_TO_PTR(journalFileSize)) );
  if( !pPtr ){
    sqlite3DbFree(0, zPathname);
    return SQLITE_NOMEM_BKPT;
  }
  pPager = (Pager*)pPtr;                  pPtr += ROUND8(sizeof(*pPager));
  pPager->pPCache = (PCache*)pPtr;        pPtr += ROUND8(pcacheSize);
  pPager->fd = (sqlite3_file*)pPtr;       pPtr += ROUND8(pVfs->szOsFile);
  pPager->sjfd = (sqlite3_file*)pPtr;     pPtr += journalFileSize;
  pPager->jfd =  (sqlite3_file*)pPtr;     pPtr += journalFileSize;
  assert( EIGHT_BYTE_ALIGNMENT(pPager->jfd) );
  memcpy(pPtr, &pPager, sizeof(pPager));  pPtr += sizeof(pPager);

  /* Fill in the Pager.zFilename and pPager.zQueryParam fields */
                                          pPtr += 4;  /* Skip zero prefix */
  pPager->zFilename = (char*)pPtr;
  if( nPathname>0 ){
    memcpy(pPtr, zPathname, nPathname);   pPtr += nPathname + 1;
    if( zUri ){

  /* memset(pPager->aHash, 0, sizeof(pPager->aHash)); */
  /* pPager->szMmap = SQLITE_DEFAULT_MMAP_SIZE // will be set by btree.c */

  *ppPager = pPager;
  return SQLITE_OK;
}

/*
** Return the sqlite3_file for the main database given the name
** of the corresonding WAL or Journal name as passed into
** xOpen.
*/
SQLITE_API sqlite3_file *sqlite3_database_file_object(const char *zName){
  Pager *pPager;
  while( zName[-1]!=0 || zName[-2]!=0 || zName[-3]!=0 || zName[-4]!=0 ){
    zName--;
  }
  pPager = *(Pager**)(zName - 4 - sizeof(Pager*));
  return pPager->fd;
}


/*
** This function is called after transitioning from PAGER_UNLOCK to
** PAGER_SHARED state. It tests if there is a hot journal present in
** the file-system for the given pager. A hot journal is one that 
** needs to be played back. According to this function, a hot-journal

      /* If the database may grow as a result of this checkpoint, hint
      ** about the eventual size of the db file to the VFS layer.
      */
      if( rc==SQLITE_OK ){
        i64 nReq = ((i64)mxPage * szPage);
        i64 nSize;                    /* Current size of database file */
        sqlite3OsFileControl(pWal->pDbFd, SQLITE_FCNTL_CKPT_START, 0);
        rc = sqlite3OsFileSize(pWal->pDbFd, &nSize);
        if( rc==SQLITE_OK && nSize<nReq ){
          sqlite3OsFileControlHint(pWal->pDbFd, SQLITE_FCNTL_SIZE_HINT, &nReq);
        }
      }

        rc = sqlite3OsRead(pWal->pWalFd, zBuf, szPage, iOffset);
        if( rc!=SQLITE_OK ) break;
        iOffset = (iDbpage-1)*(i64)szPage;
        testcase( IS_BIG_INT(iOffset) );
        rc = sqlite3OsWrite(pWal->pDbFd, zBuf, szPage, iOffset);
        if( rc!=SQLITE_OK ) break;
      }
      sqlite3OsFileControl(pWal->pDbFd, SQLITE_FCNTL_CKPT_DONE, 0);

      /* If work was actually accomplished... */
      if( rc==SQLITE_OK ){
        if( mxSafeFrame==walIndexHdr(pWal)->mxFrame ){
          i64 szDb = pWal->hdr.nPage*(i64)szPage;
          testcase( IS_BIG_INT(szDb) );
          rc = sqlite3OsTruncate(pWal->pDbFd, szDb);
          if( rc==SQLITE_OK ){
            rc = sqlite3OsSync(pWal->pDbFd, CKPT_SYNC_FLAGS(sync_flags));
          }
        }




        if( rc==SQLITE_OK ){
          pInfo->nBackfill = mxSafeFrame;
        }
      }

      /* Release the reader lock held while backfilling */
      walUnlockExclusive(pWal, WAL_READ_LOCK(0), 1);

  return n;
}

/*
** Return the number of bytes of space at the end of every page that
** are intentually left unused.  This is the "reserved" space that is
** sometimes used by extensions.
**
** The value returned is the larger of the current reserve size and
** the latest reserve size requested by SQLITE_FILECTRL_RESERVE_BYTES.
** The amount of reserve can only grow - never shrink.
*/
SQLITE_PRIVATE int sqlite3BtreeGetRequestedReserve(Btree *p){
  int n;
  sqlite3BtreeEnter(p);
  n = ((int)p->pBt->nReserveWanted) - 1;
  if( n<0 ) n = sqlite3BtreeGetReserveNoMutex(p);
  sqlite3BtreeLeave(p);

    }
#endif
  }
  sqlite3BtreeLeave(p);
  return rc;
}


/*
** The first argument, pCur, is a cursor opened on some b-tree. Count the
** number of entries in the b-tree and write the result to *pnEntry.
**
** SQLITE_OK is returned if the operation is successfully executed. 
** Otherwise, if an error is encountered (i.e. an IO error or database
** corruption) an SQLite error code is returned.

      rc = moveToChild(pCur, get4byte(findCell(pPage, iIdx)));
    }
  }

  /* An error has occurred. Return an error code. */
  return rc;
}


/*
** Return the pager associated with a BTree.  This routine is used for
** testing and debugging only.
*/
SQLITE_PRIVATE Pager *sqlite3BtreePager(Btree *p){
  return p->pBt->pPager;

** Some translation occurs:
**
**       "PX"      ->  "r[X]"
**       "PX@PY"   ->  "r[X..X+Y-1]"  or "r[x]" if y is 0 or 1
**       "PX@PY+1" ->  "r[X..X+Y]"    or "r[x]" if y is 0
**       "PY..PY"  ->  "r[X..Y]"      or "r[x]" if y<=x
*/
SQLITE_PRIVATE char *sqlite3VdbeDisplayComment(
  sqlite3 *db,       /* Optional - Oom error reporting only */
  const Op *pOp,     /* The opcode to be commented */
  const char *zP4    /* Previously obtained value for P4 */


){
  const char *zOpName;
  const char *zSynopsis;
  int nOpName;
  int ii;
  char zAlt[50];
  StrAccum x;


  sqlite3StrAccumInit(&x, 0, 0, 0, SQLITE_MAX_LENGTH);
  zOpName = sqlite3OpcodeName(pOp->opcode);
  nOpName = sqlite3Strlen30(zOpName);
  if( zOpName[nOpName+1] ){
    int seenCom = 0;
    char c;
    zSynopsis = zOpName += nOpName + 1;
    if( strncmp(zSynopsis,"IF ",3)==0 ){

    }
    if( !seenCom && pOp->zComment ){
      sqlite3_str_appendf(&x, "; %s", pOp->zComment);
    }
  }else if( pOp->zComment ){
    sqlite3_str_appendall(&x, pOp->zComment);
  }
  if( (x.accError & SQLITE_NOMEM)!=0 && db!=0 ){
    sqlite3OomFault(db);
  }
  return sqlite3StrAccumFinish(&x);

}
#endif /* SQLITE_ENABLE_EXPLAIN_COMMENTS */

#if VDBE_DISPLAY_P4 && defined(SQLITE_ENABLE_CURSOR_HINTS)
/*
** Translate the P4.pExpr value for an OP_CursorHint opcode into text
** that can be displayed in the P4 column of EXPLAIN output.
*/
static void displayP4Expr(StrAccum *p, Expr *pExpr){

#if VDBE_DISPLAY_P4
/*
** Compute a string that describes the P4 parameter for an opcode.
** Use zTemp for any required temporary buffer space.
*/
SQLITE_PRIVATE char *sqlite3VdbeDisplayP4(sqlite3 *db, Op *pOp){
  char *zP4 = 0;
  StrAccum x;

  sqlite3StrAccumInit(&x, 0, 0, 0, SQLITE_MAX_LENGTH);
  switch( pOp->p4type ){
    case P4_KEYINFO: {
      int j;
      KeyInfo *pKeyInfo = pOp->p4.pKeyInfo;
      assert( pKeyInfo->aSortFlags!=0 );
      sqlite3_str_appendf(&x, "k(%d", pKeyInfo->nKeyField);
      for(j=0; j<pKeyInfo->nKeyField; j++){

#endif
    case P4_INTARRAY: {
      int i;
      int *ai = pOp->p4.ai;
      int n = ai[0];   /* The first element of an INTARRAY is always the
                       ** count of the number of elements to follow */
      for(i=1; i<=n; i++){
        sqlite3_str_appendf(&x, "%c%d", (i==1 ? '[' : ','), ai[i]);
      }

      sqlite3_str_append(&x, "]", 1);
      break;
    }
    case P4_SUBPROGRAM: {
      zP4 = "program";
      break;
    }
    case P4_DYNBLOB:
    case P4_ADVANCE: {

      break;
    }
    case P4_TABLE: {
      zP4 = pOp->p4.pTab->zName;
      break;
    }
    default: {
      zP4 = pOp->p4.z;



    }
  }
  if( zP4 ) sqlite3_str_appendall(&x, zP4);
  if( (x.accError & SQLITE_NOMEM)!=0 ){
    sqlite3OomFault(db);
  }
  return sqlite3StrAccumFinish(&x);


}
#endif /* VDBE_DISPLAY_P4 */

/*
** Declare to the Vdbe that the BTree object at db->aDb[i] is used.
**
** The prepared statements need to know in advance the complete set of

#if defined(VDBE_PROFILE) || defined(SQLITE_DEBUG)
/*
** Print a single opcode.  This routine is used for debugging only.
*/
SQLITE_PRIVATE void sqlite3VdbePrintOp(FILE *pOut, int pc, VdbeOp *pOp){
  char *zP4;
  char *zCom;
  sqlite3 dummyDb;
  static const char *zFormat1 = "%4d %-13s %4d %4d %4d %-13s %.2X %s\n";
  if( pOut==0 ) pOut = stdout;
  dummyDb.mallocFailed = 1;
  zP4 = sqlite3VdbeDisplayP4(&dummyDb, pOp);
#ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
  zCom = sqlite3VdbeDisplayComment(0, pOp, zP4);
#else
  zCom = 0;
#endif
  /* NB:  The sqlite3OpcodeName() function is implemented by code created
  ** by the mkopcodeh.awk and mkopcodec.awk scripts which extract the
  ** information from the vdbe.c source text */
  fprintf(pOut, zFormat1, pc, 
      sqlite3OpcodeName(pOp->opcode), pOp->p1, pOp->p2, pOp->p3, 
      zP4 ? zP4 : "", pOp->p5,
      zCom ? zCom : ""
  );
  fflush(pOut);
  sqlite3_free(zP4);
  sqlite3_free(zCom);
}
#endif

/*
** Initialize an array of N Mem element.
*/
static void initMemArray(Mem *p, int N, sqlite3 *db, u16 flags){

SQLITE_PRIVATE void sqlite3VdbeFrameMemDel(void *pArg){
  VdbeFrame *pFrame = (VdbeFrame*)pArg;
  assert( sqlite3VdbeFrameIsValid(pFrame) );
  pFrame->pParent = pFrame->v->pDelFrame;
  pFrame->v->pDelFrame = pFrame;
}

#if defined(SQLITE_ENABLE_BYTECODE_VTAB) || !defined(SQLITE_OMIT_EXPLAIN)
/*
** Locate the next opcode to be displayed in EXPLAIN or EXPLAIN
** QUERY PLAN output.
**
** Return SQLITE_ROW on success.  Return SQLITE_DONE if there are no
** more opcodes to be displayed.
*/
SQLITE_PRIVATE int sqlite3VdbeNextOpcode(
  Vdbe *p,         /* The statement being explained */
  Mem *pSub,       /* Storage for keeping track of subprogram nesting */
  int eMode,       /* 0: normal.  1: EQP.  2:  TablesUsed */
  int *piPc,       /* IN/OUT: Current rowid.  Overwritten with next rowid */
  int *piAddr,     /* OUT: Write index into (*paOp)[] here */
  Op **paOp        /* OUT: Write the opcode array here */
){
  int nRow;                            /* Stop when row count reaches this */
  int nSub = 0;                        /* Number of sub-vdbes seen so far */
  SubProgram **apSub = 0;              /* Array of sub-vdbes */
  int i;                               /* Next instruction address */
  int rc = SQLITE_OK;                  /* Result code */
  Op *aOp = 0;                         /* Opcode array */
  int iPc;                             /* Rowid.  Copy of value in *piPc */

  /* When the number of output rows reaches nRow, that means the
  ** listing has finished and sqlite3_step() should return SQLITE_DONE.
  ** nRow is the sum of the number of rows in the main program, plus
  ** the sum of the number of rows in all trigger subprograms encountered
  ** so far.  The nRow value will increase as new trigger subprograms are
  ** encountered, but p->pc will eventually catch up to nRow.
  */
  nRow = p->nOp;
  if( pSub!=0 ){
    if( pSub->flags&MEM_Blob ){
      /* pSub is initiallly NULL.  It is initialized to a BLOB by
      ** the P4_SUBPROGRAM processing logic below */
      nSub = pSub->n/sizeof(Vdbe*);
      apSub = (SubProgram **)pSub->z;
    }
    for(i=0; i<nSub; i++){
      nRow += apSub[i]->nOp;
    }
  }
  iPc = *piPc;
  while(1){  /* Loop exits via break */
    i = iPc++;
    if( i>=nRow ){
      p->rc = SQLITE_OK;
      rc = SQLITE_DONE;
      break;
    }
    if( i<p->nOp ){
      /* The rowid is small enough that we are still in the
      ** main program. */
      aOp = p->aOp;
    }else{
      /* We are currently listing subprograms.  Figure out which one and
      ** pick up the appropriate opcode. */
      int j;
      i -= p->nOp;
      assert( apSub!=0 );
      assert( nSub>0 );
      for(j=0; i>=apSub[j]->nOp; j++){
        i -= apSub[j]->nOp;
        assert( i<apSub[j]->nOp || j+1<nSub );
      }
      aOp = apSub[j]->aOp;
    }

    /* When an OP_Program opcode is encounter (the only opcode that has
    ** a P4_SUBPROGRAM argument), expand the size of the array of subprograms
    ** kept in p->aMem[9].z to hold the new program - assuming this subprogram
    ** has not already been seen.
    */
    if( pSub!=0 && aOp[i].p4type==P4_SUBPROGRAM ){
      int nByte = (nSub+1)*sizeof(SubProgram*);
      int j;
      for(j=0; j<nSub; j++){
        if( apSub[j]==aOp[i].p4.pProgram ) break;
      }
      if( j==nSub ){
        p->rc = sqlite3VdbeMemGrow(pSub, nByte, nSub!=0);
        if( p->rc!=SQLITE_OK ){
          rc = SQLITE_ERROR;
          break;
        }
        apSub = (SubProgram **)pSub->z;
        apSub[nSub++] = aOp[i].p4.pProgram;
        MemSetTypeFlag(pSub, MEM_Blob);
        pSub->n = nSub*sizeof(SubProgram*);
        nRow += aOp[i].p4.pProgram->nOp;
      }
    }
    if( eMode==0 ) break;
#ifdef SQLITE_ENABLE_BYTECODE_VTAB
    if( eMode==2 ){
      Op *pOp = aOp + i;
      if( pOp->opcode==OP_OpenRead ) break;
      if( pOp->opcode==OP_OpenWrite && (pOp->p5 & OPFLAG_P2ISREG)==0 ) break;
      if( pOp->opcode==OP_ReopenIdx ) break;      
    }else
#endif
    {
      assert( eMode==1 );
      if( aOp[i].opcode==OP_Explain ) break;
      if( aOp[i].opcode==OP_Init && iPc>1 ) break;
    }
  }
  *piPc = iPc;
  *piAddr = i;
  *paOp = aOp;
  return rc;
}
#endif /* SQLITE_ENABLE_BYTECODE_VTAB || !SQLITE_OMIT_EXPLAIN */


/*
** Delete a VdbeFrame object and its contents. VdbeFrame objects are
** allocated by the OP_Program opcode in sqlite3VdbeExec().
*/
SQLITE_PRIVATE void sqlite3VdbeFrameDelete(VdbeFrame *p){
  int i;

**
** When p->explain==1, first the main program is listed, then each of
** the trigger subprograms are listed one by one.
*/
SQLITE_PRIVATE int sqlite3VdbeList(
  Vdbe *p                   /* The VDBE */
){



  Mem *pSub = 0;                       /* Memory cell hold array of subprogs */
  sqlite3 *db = p->db;                 /* The database connection */
  int i;                               /* Loop counter */
  int rc = SQLITE_OK;                  /* Return code */
  Mem *pMem = &p->aMem[1];             /* First Mem of result set */
  int bListSubprogs = (p->explain==1 || (db->flags & SQLITE_TriggerEQP)!=0);
  Op *aOp;                             /* Array of opcodes */
  Op *pOp;                             /* Current opcode */

  assert( p->explain );
  assert( p->magic==VDBE_MAGIC_RUN );
  assert( p->rc==SQLITE_OK || p->rc==SQLITE_BUSY || p->rc==SQLITE_NOMEM );

  /* Even though this opcode does not use dynamic strings for
  ** the result, result columns may become dynamic if the user calls
  ** sqlite3_column_text16(), causing a translation to UTF-16 encoding.
  */
  releaseMemArray(pMem, 8);
  p->pResultSet = 0;

  if( p->rc==SQLITE_NOMEM ){
    /* This happens if a malloc() inside a call to sqlite3_column_text() or
    ** sqlite3_column_text16() failed.  */
    sqlite3OomFault(db);
    return SQLITE_ERROR;
  }









  if( bListSubprogs ){
    /* The first 8 memory cells are used for the result set.  So we will
    ** commandeer the 9th cell to use as storage for an array of pointers
    ** to trigger subprograms.  The VDBE is guaranteed to have at least 9
    ** cells.  */
    assert( p->nMem>9 );
    pSub = &p->aMem[9];






















  }else{




    pSub = 0;




  }


  /* Figure out which opcode is next to display */












  rc = sqlite3VdbeNextOpcode(p, pSub, p->explain==2, &p->pc, &i, &aOp);
















  if( rc==SQLITE_OK ){
    pOp = aOp + i;
    if( AtomicLoad(&db->u1.isInterrupted) ){
      p->rc = SQLITE_INTERRUPT;
      rc = SQLITE_ERROR;
      sqlite3VdbeError(p, sqlite3ErrStr(p->rc));
    }else{
      char *zP4 = sqlite3VdbeDisplayP4(db, pOp);
      if( p->explain==2 ){



        sqlite3VdbeMemSetInt64(pMem, pOp->p1);







        sqlite3VdbeMemSetInt64(pMem+1, pOp->p2);



        sqlite3VdbeMemSetInt64(pMem+2, pOp->p3);



        sqlite3VdbeMemSetStr(pMem+3, zP4, -1, SQLITE_UTF8, sqlite3_free);     



        p->nResColumn = 4;









      }else{
        sqlite3VdbeMemSetInt64(pMem+0, i);
        sqlite3VdbeMemSetStr(pMem+1, (char*)sqlite3OpcodeName(pOp->opcode),
                             -1, SQLITE_UTF8, SQLITE_STATIC);

        sqlite3VdbeMemSetInt64(pMem+2, pOp->p1);
        sqlite3VdbeMemSetInt64(pMem+3, pOp->p2);

        sqlite3VdbeMemSetInt64(pMem+4, pOp->p3);







        /* pMem+5 for p4 is done last */
        sqlite3VdbeMemSetInt64(pMem+6, pOp->p5);
#ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
        {
          char *zCom = sqlite3VdbeDisplayComment(db, pOp, zP4);

          sqlite3VdbeMemSetStr(pMem+7, zCom, -1, SQLITE_UTF8, sqlite3_free);
        }



#else

        sqlite3VdbeMemSetNull(pMem+7);
#endif

        sqlite3VdbeMemSetStr(pMem+5, zP4, -1, SQLITE_UTF8, sqlite3_free);
        p->nResColumn = 8;
      }
      p->pResultSet = pMem;
      if( db->mallocFailed ){
        p->rc = SQLITE_NOMEM;
        rc = SQLITE_ERROR;
      }else{
        p->rc = SQLITE_OK;
        rc = SQLITE_ROW;
      }
    }
  }
  return rc;
}
#endif /* SQLITE_OMIT_EXPLAIN */

#ifdef SQLITE_DEBUG

    i64 offset = 0;
    int res;
    int retryCount = 0;
    int nMainFile;

    /* Select a master journal file name */
    nMainFile = sqlite3Strlen30(zMainFile);
    zMaster = sqlite3MPrintf(db, "%.4c%s%.16c", 0,zMainFile,0);
    if( zMaster==0 ) return SQLITE_NOMEM_BKPT;
    zMaster += 4;
    do {
      u32 iRandom;
      if( retryCount ){
        if( retryCount>100 ){
          sqlite3_log(SQLITE_FULL, "MJ delete: %s", zMaster);
          sqlite3OsDelete(pVfs, zMaster, 0);
          break;

      /* Open the master journal. */
      rc = sqlite3OsOpenMalloc(pVfs, zMaster, &pMaster, 
          SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE|
          SQLITE_OPEN_EXCLUSIVE|SQLITE_OPEN_MASTER_JOURNAL, 0
      );
    }
    if( rc!=SQLITE_OK ){
      sqlite3DbFree(db, zMaster-4);
      return rc;
    }
 
    /* Write the name of each database file in the transaction into the new
    ** master journal file. If an error occurs at this point close
    ** and delete the master journal file. All the individual journal files
    ** still have 'null' as the master journal pointer, so they will roll

        }
        assert( zFile[0]!=0 );
        rc = sqlite3OsWrite(pMaster, zFile, sqlite3Strlen30(zFile)+1, offset);
        offset += sqlite3Strlen30(zFile)+1;
        if( rc!=SQLITE_OK ){
          sqlite3OsCloseFree(pMaster);
          sqlite3OsDelete(pVfs, zMaster, 0);
          sqlite3DbFree(db, zMaster-4);
          return rc;
        }
      }
    }

    /* Sync the master journal file. If the IOCAP_SEQUENTIAL device
    ** flag is set this is not required.
    */
    if( 0==(sqlite3OsDeviceCharacteristics(pMaster)&SQLITE_IOCAP_SEQUENTIAL)
     && SQLITE_OK!=(rc = sqlite3OsSync(pMaster, SQLITE_SYNC_NORMAL))
    ){
      sqlite3OsCloseFree(pMaster);
      sqlite3OsDelete(pVfs, zMaster, 0);
      sqlite3DbFree(db, zMaster-4);
      return rc;
    }

    /* Sync all the db files involved in the transaction. The same call
    ** sets the master journal pointer in each individual journal. If
    ** an error occurs here, do not delete the master journal file.
    **

      if( pBt ){
        rc = sqlite3BtreeCommitPhaseOne(pBt, zMaster);
      }
    }
    sqlite3OsCloseFree(pMaster);
    assert( rc!=SQLITE_BUSY );
    if( rc!=SQLITE_OK ){
      sqlite3DbFree(db, zMaster-4);
      return rc;
    }

    /* Delete the master journal file. This commits the transaction. After
    ** doing this the directory is synced again before any individual
    ** transaction files are deleted.
    */
    rc = sqlite3OsDelete(pVfs, zMaster, 1);
    sqlite3DbFree(db, zMaster-4);
    zMaster = 0;
    if( rc ){
      return rc;
    }

    /* All files and directories have already been synced, so the following
    ** calls to sqlite3BtreeCommitPhaseTwo() are only closing files and

  assert( nByte==(int)(zPayload - (u8*)pOut->z) );

  assert( pOp->p3>0 && pOp->p3<=(p->nMem+1 - p->nCursor) );
  REGISTER_TRACE(pOp->p3, pOut);
  break;
}

/* Opcode: Count P1 P2 p3 * *
** Synopsis: r[P2]=count()
**
** Store the number of entries (an integer value) in the table or index 
** opened by cursor P1 in register P2.
**
** If P3==0, then an exact count is obtained, which involves visiting
** every btree page of the table.  But if P3 is non-zero, an estimate
** is returned based on the current cursor position.  
*/

case OP_Count: {         /* out2 */
  i64 nEntry;
  BtCursor *pCrsr;

  assert( p->apCsr[pOp->p1]->eCurType==CURTYPE_BTREE );
  pCrsr = p->apCsr[pOp->p1]->uc.pCursor;
  assert( pCrsr );
  if( pOp->p3 ){
    nEntry = sqlite3BtreeRowCountEst(pCrsr);
  }else{
    nEntry = 0;  /* Not needed.  Only used to silence a warning. */
    rc = sqlite3BtreeCount(db, pCrsr, &nEntry);
    if( rc ) goto abort_due_to_error;
  }
  pOut = out2Prerelease(p, pOp);
  pOut->u.i = nEntry;
  goto check_for_interrupt;
}


/* Opcode: Savepoint P1 * * P4 *
**
** Open, release or rollback the savepoint named by parameter P4, depending
** on the value of P1. To open a new savepoint set P1==0 (SAVEPOINT_BEGIN).
** To release (commit) an existing savepoint set P1==1 (SAVEPOINT_RELEASE).
** To rollback an existing savepoint set P1==2 (SAVEPOINT_ROLLBACK).

  }

  *pRes = sqlite3VdbeRecordCompare(pVal->n, pVal->z, r2);
  return SQLITE_OK;
}

/************** End of vdbesort.c ********************************************/
/************** Begin file vdbevtab.c ****************************************/
/*
** 2020-03-23
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** This file implements virtual-tables for examining the bytecode content
** of a prepared statement.
*/
#ifdef SQLITE_ENABLE_BYTECODE_VTAB
/* #include "sqliteInt.h" */
/* #include "vdbeInt.h" */

/* An instance of the bytecode() table-valued function.
*/
typedef struct bytecodevtab bytecodevtab;
struct bytecodevtab {
  sqlite3_vtab base;     /* Base class - must be first */
  sqlite3 *db;           /* Database connection */
  int bTablesUsed;       /* 2 for tables_used().  0 for bytecode(). */
};

/* A cursor for scanning through the bytecode
*/
typedef struct bytecodevtab_cursor bytecodevtab_cursor;
struct bytecodevtab_cursor {
  sqlite3_vtab_cursor base;  /* Base class - must be first */
  sqlite3_stmt *pStmt;       /* The statement whose bytecode is displayed */
  int iRowid;                /* The rowid of the output table */
  int iAddr;                 /* Address */
  int needFinalize;          /* Cursors owns pStmt and must finalize it */
  int showSubprograms;       /* Provide a listing of subprograms */
  Op *aOp;                   /* Operand array */
  char *zP4;                 /* Rendered P4 value */
  const char *zType;         /* tables_used.type */
  const char *zSchema;       /* tables_used.schema */
  const char *zName;         /* tables_used.name */
  Mem sub;                   /* Subprograms */
};

/*
** Create a new bytecode() table-valued function.
*/
static int bytecodevtabConnect(
  sqlite3 *db,
  void *pAux,
  int argc, const char *const*argv,
  sqlite3_vtab **ppVtab,
  char **pzErr
){
  bytecodevtab *pNew;
  int rc;
  int isTabUsed = pAux!=0;
  const char *azSchema[2] = {
    /* bytecode() schema */
    "CREATE TABLE x("
      "addr INT,"
      "opcode TEXT,"
      "p1 INT,"
      "p2 INT,"
      "p3 INT,"
      "p4 TEXT,"
      "p5 INT,"
      "comment TEXT,"
      "subprog TEXT," 
      "stmt HIDDEN"
    ");",

    /* Tables_used() schema */
    "CREATE TABLE x("
      "type TEXT,"
      "schema TEXT,"
      "name TEXT,"
      "wr INT,"
      "subprog TEXT," 
      "stmt HIDDEN"
   ");"
  };

  rc = sqlite3_declare_vtab(db, azSchema[isTabUsed]);
  if( rc==SQLITE_OK ){
    pNew = sqlite3_malloc( sizeof(*pNew) );
    *ppVtab = (sqlite3_vtab*)pNew;
    if( pNew==0 ) return SQLITE_NOMEM;
    memset(pNew, 0, sizeof(*pNew));
    pNew->db = db;
    pNew->bTablesUsed = isTabUsed*2;
  }
  return rc;
}

/*
** This method is the destructor for bytecodevtab objects.
*/
static int bytecodevtabDisconnect(sqlite3_vtab *pVtab){
  bytecodevtab *p = (bytecodevtab*)pVtab;
  sqlite3_free(p);
  return SQLITE_OK;
}

/*
** Constructor for a new bytecodevtab_cursor object.
*/
static int bytecodevtabOpen(sqlite3_vtab *p, sqlite3_vtab_cursor **ppCursor){
  bytecodevtab *pVTab = (bytecodevtab*)p;
  bytecodevtab_cursor *pCur;
  pCur = sqlite3_malloc( sizeof(*pCur) );
  if( pCur==0 ) return SQLITE_NOMEM;
  memset(pCur, 0, sizeof(*pCur));
  sqlite3VdbeMemInit(&pCur->sub, pVTab->db, 1);
  *ppCursor = &pCur->base;
  return SQLITE_OK;
}

/*
** Clear all internal content from a bytecodevtab cursor.
*/
static void bytecodevtabCursorClear(bytecodevtab_cursor *pCur){
  sqlite3_free(pCur->zP4);
  pCur->zP4 = 0;
  sqlite3VdbeMemRelease(&pCur->sub);
  sqlite3VdbeMemSetNull(&pCur->sub);
  if( pCur->needFinalize ){
    sqlite3_finalize(pCur->pStmt);
  }
  pCur->pStmt = 0;
  pCur->needFinalize = 0;
  pCur->zType = 0;
  pCur->zSchema = 0;
  pCur->zName = 0;
}

/*
** Destructor for a bytecodevtab_cursor.
*/
static int bytecodevtabClose(sqlite3_vtab_cursor *cur){
  bytecodevtab_cursor *pCur = (bytecodevtab_cursor*)cur;
  bytecodevtabCursorClear(pCur);
  sqlite3_free(pCur);
  return SQLITE_OK;
}


/*
** Advance a bytecodevtab_cursor to its next row of output.
*/
static int bytecodevtabNext(sqlite3_vtab_cursor *cur){
  bytecodevtab_cursor *pCur = (bytecodevtab_cursor*)cur;
  bytecodevtab *pTab = (bytecodevtab*)cur->pVtab;
  int rc;
  if( pCur->zP4 ){
    sqlite3_free(pCur->zP4);
    pCur->zP4 = 0;
  }
  if( pCur->zName ){
    pCur->zName = 0;
    pCur->zType = 0;
    pCur->zSchema = 0;
  }
  rc = sqlite3VdbeNextOpcode(
           (Vdbe*)pCur->pStmt, 
           pCur->showSubprograms ? &pCur->sub : 0,
           pTab->bTablesUsed,
           &pCur->iRowid,
           &pCur->iAddr,
           &pCur->aOp);
  if( rc!=SQLITE_OK ){
    sqlite3VdbeMemSetNull(&pCur->sub);
    pCur->aOp = 0;
  }
  return SQLITE_OK;
}

/*
** Return TRUE if the cursor has been moved off of the last
** row of output.
*/
static int bytecodevtabEof(sqlite3_vtab_cursor *cur){
  bytecodevtab_cursor *pCur = (bytecodevtab_cursor*)cur;
  return pCur->aOp==0;
}

/*
** Return values of columns for the row at which the bytecodevtab_cursor
** is currently pointing.
*/
static int bytecodevtabColumn(
  sqlite3_vtab_cursor *cur,   /* The cursor */
  sqlite3_context *ctx,       /* First argument to sqlite3_result_...() */
  int i                       /* Which column to return */
){
  bytecodevtab_cursor *pCur = (bytecodevtab_cursor*)cur;
  bytecodevtab *pVTab = (bytecodevtab*)cur->pVtab;
  Op *pOp = pCur->aOp + pCur->iAddr;
  if( pVTab->bTablesUsed ){
    if( i==4 ){
      i = 8;
    }else{
      if( i<=2 && pCur->zType==0 ){
        Schema *pSchema;
        HashElem *k;
        int iDb = pOp->p3;
        int iRoot = pOp->p2;
        sqlite3 *db = pVTab->db;
        pSchema = db->aDb[iDb].pSchema;
        pCur->zSchema = db->aDb[iDb].zDbSName;
        for(k=sqliteHashFirst(&pSchema->tblHash); k; k=sqliteHashNext(k)){
          Table *pTab = (Table*)sqliteHashData(k);
          if( !IsVirtual(pTab) && pTab->tnum==iRoot ){
            pCur->zName = pTab->zName;
            pCur->zType = "table";
            break;
          }
        }
        if( pCur->zName==0 ){
          for(k=sqliteHashFirst(&pSchema->idxHash); k; k=sqliteHashNext(k)){
            Index *pIdx = (Index*)sqliteHashData(k);
            if( pIdx->tnum==iRoot ){
              pCur->zName = pIdx->zName;
              pCur->zType = "index";
            }
          }
        }
      }
      i += 10;
    }
  }
  switch( i ){
    case 0:   /* addr */
      sqlite3_result_int(ctx, pCur->iAddr);
      break;
    case 1:   /* opcode */
      sqlite3_result_text(ctx, (char*)sqlite3OpcodeName(pOp->opcode),
                          -1, SQLITE_STATIC);
      break;
    case 2:   /* p1 */
      sqlite3_result_int(ctx, pOp->p1);
      break;
    case 3:   /* p2 */
      sqlite3_result_int(ctx, pOp->p2);
      break;
    case 4:   /* p3 */
      sqlite3_result_int(ctx, pOp->p3);
      break;
    case 5:   /* p4 */
    case 7:   /* comment */
      if( pCur->zP4==0 ){
        pCur->zP4 = sqlite3VdbeDisplayP4(pVTab->db, pOp);
      }
      if( i==5 ){
        sqlite3_result_text(ctx, pCur->zP4, -1, SQLITE_STATIC);
      }else{
#ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
        char *zCom = sqlite3VdbeDisplayComment(pVTab->db, pOp, pCur->zP4);
        sqlite3_result_text(ctx, zCom, -1, sqlite3_free);
#endif
      }
      break;
    case 6:     /* p5 */
      sqlite3_result_int(ctx, pOp->p5);
      break;
    case 8: {   /* subprog */
      Op *aOp = pCur->aOp;
      assert( aOp[0].opcode==OP_Init );
      assert( aOp[0].p4.z==0 || strncmp(aOp[0].p4.z,"-" "- ",3)==0 );
      if( pCur->iRowid==pCur->iAddr+1 ){
        break;  /* Result is NULL for the main program */
      }else if( aOp[0].p4.z!=0 ){
         sqlite3_result_text(ctx, aOp[0].p4.z+3, -1, SQLITE_STATIC);
      }else{
         sqlite3_result_text(ctx, "(FK)", 4, SQLITE_STATIC);
      }
      break;
    }
    case 10:  /* tables_used.type */
      sqlite3_result_text(ctx, pCur->zType, -1, SQLITE_STATIC);
      break;
    case 11:  /* tables_used.schema */
      sqlite3_result_text(ctx, pCur->zSchema, -1, SQLITE_STATIC);
      break;
    case 12:  /* tables_used.name */
      sqlite3_result_text(ctx, pCur->zName, -1, SQLITE_STATIC);
      break;
    case 13:  /* tables_used.wr */
      sqlite3_result_int(ctx, pOp->opcode==OP_OpenWrite);
      break;
  }
  return SQLITE_OK;
}

/*
** Return the rowid for the current row.  In this implementation, the
** rowid is the same as the output value.
*/
static int bytecodevtabRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){
  bytecodevtab_cursor *pCur = (bytecodevtab_cursor*)cur;
  *pRowid = pCur->iRowid;
  return SQLITE_OK;
}

/*
** Initialize a cursor.
**
**    idxNum==0     means show all subprograms
**    idxNum==1     means show only the main bytecode and omit subprograms.
*/
static int bytecodevtabFilter(
  sqlite3_vtab_cursor *pVtabCursor, 
  int idxNum, const char *idxStr,
  int argc, sqlite3_value **argv
){
  bytecodevtab_cursor *pCur = (bytecodevtab_cursor *)pVtabCursor;
  bytecodevtab *pVTab = (bytecodevtab *)pVtabCursor->pVtab;
  int rc = SQLITE_OK;

  bytecodevtabCursorClear(pCur);
  pCur->iRowid = 0;
  pCur->iAddr = 0;
  pCur->showSubprograms = idxNum==0;
  assert( argc==1 );
  if( sqlite3_value_type(argv[0])==SQLITE_TEXT ){
    const char *zSql = (const char*)sqlite3_value_text(argv[0]);
    if( zSql==0 ){
      rc = SQLITE_NOMEM;
    }else{
      rc = sqlite3_prepare_v2(pVTab->db, zSql, -1, &pCur->pStmt, 0);
      pCur->needFinalize = 1;
    }
  }else{
    pCur->pStmt = (sqlite3_stmt*)sqlite3_value_pointer(argv[0],"stmt-pointer");
  }
  if( pCur->pStmt==0 ){
    pVTab->base.zErrMsg = sqlite3_mprintf(
       "argument to %s() is not a valid SQL statement",
       pVTab->bTablesUsed ? "tables_used" : "bytecode"
    );
    rc = SQLITE_ERROR;
  }else{
    bytecodevtabNext(pVtabCursor);
  }
  return rc;
}

/*
** We must have a single stmt=? constraint that will be passed through
** into the xFilter method.  If there is no valid stmt=? constraint,
** then return an SQLITE_CONSTRAINT error.
*/
static int bytecodevtabBestIndex(
  sqlite3_vtab *tab,
  sqlite3_index_info *pIdxInfo
){
  int i;
  int rc = SQLITE_CONSTRAINT;
  struct sqlite3_index_constraint *p;
  bytecodevtab *pVTab = (bytecodevtab*)tab;
  int iBaseCol = pVTab->bTablesUsed ? 4 : 8;
  pIdxInfo->estimatedCost = (double)100;
  pIdxInfo->estimatedRows = 100;
  pIdxInfo->idxNum = 0;
  for(i=0, p=pIdxInfo->aConstraint; i<pIdxInfo->nConstraint; i++, p++){
    if( p->usable==0 ) continue;
    if( p->op==SQLITE_INDEX_CONSTRAINT_EQ && p->iColumn==iBaseCol+1 ){
      rc = SQLITE_OK;
      pIdxInfo->aConstraintUsage[i].omit = 1;
      pIdxInfo->aConstraintUsage[i].argvIndex = 1;
    }
    if( p->op==SQLITE_INDEX_CONSTRAINT_ISNULL && p->iColumn==iBaseCol ){
      pIdxInfo->aConstraintUsage[i].omit = 1;
      pIdxInfo->idxNum = 1;
    }
  }
  return rc;
}

/*
** This following structure defines all the methods for the 
** virtual table.
*/
static sqlite3_module bytecodevtabModule = {
  /* iVersion    */ 0,
  /* xCreate     */ 0,
  /* xConnect    */ bytecodevtabConnect,
  /* xBestIndex  */ bytecodevtabBestIndex,
  /* xDisconnect */ bytecodevtabDisconnect,
  /* xDestroy    */ 0,
  /* xOpen       */ bytecodevtabOpen,
  /* xClose      */ bytecodevtabClose,
  /* xFilter     */ bytecodevtabFilter,
  /* xNext       */ bytecodevtabNext,
  /* xEof        */ bytecodevtabEof,
  /* xColumn     */ bytecodevtabColumn,
  /* xRowid      */ bytecodevtabRowid,
  /* xUpdate     */ 0,
  /* xBegin      */ 0,
  /* xSync       */ 0,
  /* xCommit     */ 0,
  /* xRollback   */ 0,
  /* xFindMethod */ 0,
  /* xRename     */ 0,
  /* xSavepoint  */ 0,
  /* xRelease    */ 0,
  /* xRollbackTo */ 0,
  /* xShadowName */ 0
};


SQLITE_PRIVATE int sqlite3VdbeBytecodeVtabInit(sqlite3 *db){
  int rc;
  rc = sqlite3_create_module(db, "bytecode", &bytecodevtabModule, 0);
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_module(db, "tables_used", &bytecodevtabModule, &db);
  }
  return rc;
}
#endif /* SQLITE_ENABLE_BYTECODE_VTAB */

/************** End of vdbevtab.c ********************************************/
/************** Begin file memjournal.c **************************************/
/*
** 2008 October 7
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**

** SELECT * FROM t1 WHERE a;
** SELECT a AS b FROM t1 WHERE b;
** SELECT * FROM t1 WHERE (select a from t1);
*/
SQLITE_PRIVATE char sqlite3ExprAffinity(const Expr *pExpr){
  int op;
  while( ExprHasProperty(pExpr, EP_Skip) ){
    assert( pExpr->op==TK_COLLATE || pExpr->op==TK_IF_NULL_ROW );
    pExpr = pExpr->pLeft;
    assert( pExpr!=0 );
  }
  op = pExpr->op;
  if( op==TK_SELECT ){
    assert( pExpr->flags&EP_xIsSelect );
    return sqlite3ExprAffinity(pExpr->x.pSelect->pEList->a[0].pExpr);

}

/*
** Skip over any TK_COLLATE operators.
*/
SQLITE_PRIVATE Expr *sqlite3ExprSkipCollate(Expr *pExpr){
  while( pExpr && ExprHasProperty(pExpr, EP_Skip) ){
    assert( pExpr->op==TK_COLLATE || pExpr->op==TK_IF_NULL_ROW );
    pExpr = pExpr->pLeft;
  }   
  return pExpr;
}

/*
** Skip over any TK_COLLATE operators and/or any unlikely()
** or likelihood() or likely() functions at the root of an
** expression.
*/
SQLITE_PRIVATE Expr *sqlite3ExprSkipCollateAndLikely(Expr *pExpr){
  while( pExpr && ExprHasProperty(pExpr, EP_Skip|EP_Unlikely) ){
    if( ExprHasProperty(pExpr, EP_Unlikely) ){
      assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
      assert( pExpr->x.pList->nExpr>0 );
      assert( pExpr->op==TK_FUNCTION );
      pExpr = pExpr->x.pList->a[0].pExpr;
    }else{
      assert( pExpr->op==TK_COLLATE || pExpr->op==TK_IF_NULL_ROW );
      pExpr = pExpr->pLeft;
    }
  }   
  return pExpr;
}

/*

  };
  int i;
  sqlite3 *db = pParse->db;
  Db *pDb;
  Vdbe *v = sqlite3GetVdbe(pParse);
  int aRoot[ArraySize(aTable)];
  u8 aCreateTbl[ArraySize(aTable)];
#ifdef SQLITE_ENABLE_STAT4
  const int nToOpen = OptimizationEnabled(db,SQLITE_Stat4) ? 2 : 1;
#else
  const int nToOpen = 1;
#endif

  if( v==0 ) return;
  assert( sqlite3BtreeHoldsAllMutexes(db) );
  assert( sqlite3VdbeDb(v)==db );
  pDb = &db->aDb[iDb];

  /* Create new statistic tables if they do not exist, or clear them
  ** if they do already exist.
  */
  for(i=0; i<ArraySize(aTable); i++){
    const char *zTab = aTable[i].zName;
    Table *pStat;
    aCreateTbl[i] = 0;
    if( (pStat = sqlite3FindTable(db, zTab, pDb->zDbSName))==0 ){
      if( i<nToOpen ){
        /* The sqlite_statN table does not exist. Create it. Note that a 
        ** side-effect of the CREATE TABLE statement is to leave the rootpage 
        ** of the new table in register pParse->regRoot. This is important 
        ** because the OpenWrite opcode below will be needing it. */
        sqlite3NestedParse(pParse,
            "CREATE TABLE %Q.%s(%s)", pDb->zDbSName, zTab, aTable[i].zCols
        );
        aRoot[i] = pParse->regRoot;
        aCreateTbl[i] = OPFLAG_P2ISREG;
      }
    }else{
      /* The table already exists. If zWhere is not NULL, delete all entries 
      ** associated with the table zWhere. If zWhere is NULL, delete the
      ** entire contents of the table. */
      aRoot[i] = pStat->tnum;

      sqlite3TableLock(pParse, iDb, aRoot[i], 1, zTab);
      if( zWhere ){
        sqlite3NestedParse(pParse,
           "DELETE FROM %Q.%s WHERE %s=%Q",
           pDb->zDbSName, zTab, zWhereType, zWhere
        );
#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
      }else if( db->xPreUpdateCallback ){
        sqlite3NestedParse(pParse, "DELETE FROM %Q.%s", pDb->zDbSName, zTab);
#endif
      }else{
        /* The sqlite_stat[134] table already exists.  Delete all rows. */
        sqlite3VdbeAddOp2(v, OP_Clear, aRoot[i], iDb);
      }
    }
  }

  /* Open the sqlite_stat[134] tables for writing. */
  for(i=0; i<nToOpen; i++){
    assert( i<ArraySize(aTable) );
    sqlite3VdbeAddOp4Int(v, OP_OpenWrite, iStatCur+i, aRoot[i], iDb, 3);
    sqlite3VdbeChangeP5(v, aCreateTbl[i]);
    VdbeComment((v, aTable[i].zName));
  }
}

  u8 isPSample;                   /* True if a periodic sample */
  int iCol;                       /* If !isPSample, the reason for inclusion */
  u32 iHash;                      /* Tiebreaker hash */
#endif
};                                                    
struct StatAccum {
  sqlite3 *db;              /* Database connection, for malloc() */
  tRowcnt nEst;             /* Estimated number of rows */
  tRowcnt nRow;             /* Number of rows visited so far */
  int nLimit;               /* Analysis row-scan limit */
  int nCol;                 /* Number of columns in index + pk/rowid */
  int nKeyCol;              /* Number of index columns w/o the pk/rowid */
  u8 nSkipAhead;            /* Number of times of skip-ahead */
  StatSample current;       /* Current row as a StatSample */
#ifdef SQLITE_ENABLE_STAT4
  tRowcnt nPSample;         /* How often to do a periodic sample */
  int mxSample;             /* Maximum number of samples to accumulate */
  u32 iPrn;                 /* Pseudo-random number used for sampling */
  StatSample *aBest;        /* Array of nCol best samples */
  int iMin;                 /* Index in a[] of entry with minimum score */

/*
** Reclaim all memory of a StatAccum structure.
*/
static void statAccumDestructor(void *pOld){
  StatAccum *p = (StatAccum*)pOld;
#ifdef SQLITE_ENABLE_STAT4
  if( p->mxSample ){
    int i;
    for(i=0; i<p->nCol; i++) sampleClear(p->db, p->aBest+i);
    for(i=0; i<p->mxSample; i++) sampleClear(p->db, p->a+i);
    sampleClear(p->db, &p->current);
  }
#endif
  sqlite3DbFree(p->db, p);
}

/*
** Implementation of the stat_init(N,K,C,L) SQL function. The four parameters
** are:
**     N:    The number of columns in the index including the rowid/pk (note 1)
**     K:    The number of columns in the index excluding the rowid/pk.
**     C:    Estimated number of rows in the index
**     L:    A limit on the number of rows to scan, or 0 for no-limit 
**
** Note 1:  In the special case of the covering index that implements a
** WITHOUT ROWID table, N is the number of PRIMARY KEY columns, not the
** total number of columns in the table.
**


** For indexes on ordinary rowid tables, N==K+1.  But for indexes on
** WITHOUT ROWID tables, N=K+P where P is the number of columns in the
** PRIMARY KEY of the table.  The covering index that implements the
** original WITHOUT ROWID table as N==K as a special case.
**
** This routine allocates the StatAccum object in heap memory. The return 
** value is a pointer to the StatAccum object.  The datatype of the
** return value is BLOB, but it is really just a pointer to the StatAccum
** object.
*/
static void statInit(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  StatAccum *p;
  int nCol;                       /* Number of columns in index being sampled */
  int nKeyCol;                    /* Number of key columns */
  int nColUp;                     /* nCol rounded up for alignment */
  int n;                          /* Bytes of space to allocate */
  sqlite3 *db = sqlite3_context_db_handle(context);   /* Database connection */
#ifdef SQLITE_ENABLE_STAT4
  /* Maximum number of samples.  0 if STAT4 data is not collected */
  int mxSample = OptimizationEnabled(db,SQLITE_Stat4) ?SQLITE_STAT4_SAMPLES :0;
#endif

  /* Decode the three function arguments */
  UNUSED_PARAMETER(argc);
  nCol = sqlite3_value_int(argv[0]);
  assert( nCol>0 );
  nColUp = sizeof(tRowcnt)<8 ? (nCol+1)&~1 : nCol;
  nKeyCol = sqlite3_value_int(argv[1]);
  assert( nKeyCol<=nCol );
  assert( nKeyCol>0 );

  /* Allocate the space required for the StatAccum object */
  n = sizeof(*p) 
    + sizeof(tRowcnt)*nColUp                  /* StatAccum.anEq */
    + sizeof(tRowcnt)*nColUp;                 /* StatAccum.anDLt */
#ifdef SQLITE_ENABLE_STAT4
  if( mxSample ){
    n += sizeof(tRowcnt)*nColUp                  /* StatAccum.anLt */
      + sizeof(StatSample)*(nCol+mxSample)       /* StatAccum.aBest[], a[] */
      + sizeof(tRowcnt)*3*nColUp*(nCol+mxSample);
  }
#endif

  db = sqlite3_context_db_handle(context);
  p = sqlite3DbMallocZero(db, n);
  if( p==0 ){
    sqlite3_result_error_nomem(context);
    return;
  }

  p->db = db;
  p->nEst = sqlite3_value_int64(argv[2]);
  p->nRow = 0;
  p->nLimit = sqlite3_value_int64(argv[3]);
  p->nCol = nCol;
  p->nKeyCol = nKeyCol;
  p->nSkipAhead = 0;
  p->current.anDLt = (tRowcnt*)&p[1];
  p->current.anEq = &p->current.anDLt[nColUp];

#ifdef SQLITE_ENABLE_STAT4

  p->mxSample = p->nLimit==0 ? mxSample : 0;
  if( mxSample ){
    u8 *pSpace;                     /* Allocated space not yet assigned */
    int i;                          /* Used to iterate through p->aSample[] */

    p->iGet = -1;

    p->nPSample = (tRowcnt)(p->nEst/(mxSample/3+1) + 1);
    p->current.anLt = &p->current.anEq[nColUp];
    p->iPrn = 0x689e962d*(u32)nCol ^ 0xd0944565*(u32)sqlite3_value_int(argv[2]);
  
    /* Set up the StatAccum.a[] and aBest[] arrays */
    p->a = (struct StatSample*)&p->current.anLt[nColUp];
    p->aBest = &p->a[mxSample];
    pSpace = (u8*)(&p->a[mxSample+nCol]);

  /* Return a pointer to the allocated object to the caller.  Note that
  ** only the pointer (the 2nd parameter) matters.  The size of the object
  ** (given by the 3rd parameter) is never used and can be any positive
  ** value. */
  sqlite3_result_blob(context, p, sizeof(*p), statAccumDestructor);
}
static const FuncDef statInitFuncdef = {
  4,               /* nArg */
  SQLITE_UTF8,     /* funcFlags */
  0,               /* pUserData */
  0,               /* pNext */
  statInit,        /* xSFunc */
  0,               /* xFinalize */
  0, 0,            /* xValue, xInverse */
  "stat_init",     /* zName */

** Arguments:
**
**    P     Pointer to the StatAccum object created by stat_init()
**    C     Index of left-most column to differ from previous row
**    R     Rowid for the current row.  Might be a key record for
**          WITHOUT ROWID tables.
**
** The purpose of this routine is to collect statistical data and/or
** samples from the index being analyzed into the StatAccum object.
** The stat_get() SQL function will be used afterwards to
** retrieve the information gathered.
**
** This SQL function usually returns NULL, but might return an integer
** if it wants the byte-code to do special processing.
**
** The R parameter is only used for STAT4
*/
static void statPush(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv

  if( p->nRow==0 ){
    /* This is the first call to this function. Do initialization. */
    for(i=0; i<p->nCol; i++) p->current.anEq[i] = 1;
  }else{
    /* Second and subsequent calls get processed here */
#ifdef SQLITE_ENABLE_STAT4
    if( p->mxSample ) samplePushPrevious(p, iChng);
#endif

    /* Update anDLt[], anLt[] and anEq[] to reflect the values that apply
    ** to the current row of the index. */
    for(i=0; i<iChng; i++){
      p->current.anEq[i]++;
    }
    for(i=iChng; i<p->nCol; i++){
      p->current.anDLt[i]++;
#ifdef SQLITE_ENABLE_STAT4
      if( p->mxSample ) p->current.anLt[i] += p->current.anEq[i];
#endif
      p->current.anEq[i] = 1;
    }
  }

  p->nRow++;
#ifdef SQLITE_ENABLE_STAT4
  if( p->mxSample ){
    tRowcnt nLt;
    if( sqlite3_value_type(argv[2])==SQLITE_INTEGER ){
      sampleSetRowidInt64(p->db, &p->current, sqlite3_value_int64(argv[2]));
    }else{
      sampleSetRowid(p->db, &p->current, sqlite3_value_bytes(argv[2]),
                                         sqlite3_value_blob(argv[2]));
    }
    p->current.iHash = p->iPrn = p->iPrn*1103515245 + 12345;




    nLt = p->current.anLt[p->nCol-1];

    /* Check if this is to be a periodic sample. If so, add it. */
    if( (nLt/p->nPSample)!=(nLt+1)/p->nPSample ){
      p->current.isPSample = 1;
      p->current.iCol = 0;
      sampleInsert(p, &p->current, p->nCol-1);
      p->current.isPSample = 0;
    }

    /* Update the aBest[] array. */
    for(i=0; i<(p->nCol-1); i++){
      p->current.iCol = i;
      if( i>=iChng || sampleIsBetterPost(p, &p->current, &p->aBest[i]) ){
        sampleCopy(p, &p->aBest[i], &p->current);
      }
    }
  }else
#endif
  if( p->nLimit && p->nRow>(tRowcnt)p->nLimit*(p->nSkipAhead+1) ){
    p->nSkipAhead++;
    sqlite3_result_int(context, p->current.anDLt[0]>0);
  }
}

static const FuncDef statPushFuncdef = {
  2+IsStat4,       /* nArg */
  SQLITE_UTF8,     /* funcFlags */
  0,               /* pUserData */
  0,               /* pNext */
  statPush,        /* xSFunc */
  0,               /* xFinalize */

  /* STAT4 has a parameter on this routine. */
  int eCall = sqlite3_value_int(argv[1]);
  assert( argc==2 );
  assert( eCall==STAT_GET_STAT1 || eCall==STAT_GET_NEQ 
       || eCall==STAT_GET_ROWID || eCall==STAT_GET_NLT
       || eCall==STAT_GET_NDLT 
  );
  assert( eCall==STAT_GET_STAT1 || p->mxSample );
  if( eCall==STAT_GET_STAT1 )
#else
  assert( argc==1 );
#endif
  {
    /* Return the value to store in the "stat" column of the sqlite_stat1
    ** table for this index.

    char *zRet = sqlite3MallocZero( (p->nKeyCol+1)*25 );
    if( zRet==0 ){
      sqlite3_result_error_nomem(context);
      return;
    }

    sqlite3_snprintf(24, zRet, "%llu", 
        p->nSkipAhead ? (u64)p->nEst : (u64)p->nRow);
    z = zRet + sqlite3Strlen30(zRet);
    for(i=0; i<p->nKeyCol; i++){
      u64 nDistinct = p->current.anDLt[i] + 1;
      u64 iVal = (p->nRow + nDistinct - 1) / nDistinct;
      sqlite3_snprintf(24, z, " %llu", iVal);
      z += sqlite3Strlen30(z);
      assert( p->current.anEq[i] );

  statGet,         /* xSFunc */
  0,               /* xFinalize */
  0, 0,            /* xValue, xInverse */
  "stat_get",      /* zName */
  {0}
};

static void callStatGet(Parse *pParse, int regStat, int iParam, int regOut){
#ifdef SQLITE_ENABLE_STAT4
  sqlite3VdbeAddOp2(pParse->pVdbe, OP_Integer, iParam, regStat+1);
#elif SQLITE_DEBUG
  assert( iParam==STAT_GET_STAT1 );
#else
  UNUSED_PARAMETER( iParam );
#endif
  assert( regOut!=regStat && regOut!=regStat+1 );
  sqlite3VdbeAddFunctionCall(pParse, 0, regStat, regOut, 1+IsStat4,
                             &statGetFuncdef, 0);
}

/*
** Generate code to do an analysis of all indices associated with
** a single table.
*/

  int iTabCur;                 /* Table cursor */
  Vdbe *v;                     /* The virtual machine being built up */
  int i;                       /* Loop counter */
  int jZeroRows = -1;          /* Jump from here if number of rows is zero */
  int iDb;                     /* Index of database containing pTab */
  u8 needTableCnt = 1;         /* True to count the table */
  int regNewRowid = iMem++;    /* Rowid for the inserted record */
  int regStat = iMem++;        /* Register to hold StatAccum object */
  int regChng = iMem++;        /* Index of changed index field */

  int regRowid = iMem++;       /* Rowid argument passed to stat_push() */

  int regTemp = iMem++;        /* Temporary use register */
  int regTemp2 = iMem++;       /* Second temporary use register */
  int regTabname = iMem++;     /* Register containing table name */
  int regIdxname = iMem++;     /* Register containing index name */
  int regStat1 = iMem++;       /* Value for the stat column of sqlite_stat1 */
  int regPrev = iMem;          /* MUST BE LAST (see below) */
#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
  Table *pStat1 = 0; 
#endif

    VdbeComment((v, "%s", pIdx->zName));

    /* Invoke the stat_init() function. The arguments are:
    ** 
    **    (1) the number of columns in the index including the rowid
    **        (or for a WITHOUT ROWID table, the number of PK columns),
    **    (2) the number of columns in the key without the rowid/pk
    **    (3) estimated number of rows in the index,



    */
    sqlite3VdbeAddOp2(v, OP_Integer, nCol, regStat+1);
    assert( regRowid==regStat+2 );
    sqlite3VdbeAddOp2(v, OP_Integer, pIdx->nKeyCol, regRowid);
#ifdef SQLITE_ENABLE_STAT4
    if( OptimizationEnabled(db, SQLITE_Stat4) ){
      sqlite3VdbeAddOp2(v, OP_Count, iIdxCur, regTemp);
      addrRewind = sqlite3VdbeAddOp1(v, OP_Rewind, iIdxCur);
      VdbeCoverage(v);
    }else
#endif
    {
      addrRewind = sqlite3VdbeAddOp1(v, OP_Rewind, iIdxCur);
      VdbeCoverage(v);
      sqlite3VdbeAddOp3(v, OP_Count, iIdxCur, regTemp, 1);
    }
    assert( regTemp2==regStat+4 );
    sqlite3VdbeAddOp2(v, OP_Integer, db->nAnalysisLimit, regTemp2);
    sqlite3VdbeAddFunctionCall(pParse, 0, regStat+1, regStat, 4,
                               &statInitFuncdef, 0);

    /* Implementation of the following:
    **
    **   Rewind csr
    **   if eof(csr) goto end_of_scan;
    **   regChng = 0
    **   goto next_push_0;
    **
    */


    sqlite3VdbeAddOp2(v, OP_Integer, 0, regChng);
    addrNextRow = sqlite3VdbeCurrentAddr(v);

    if( nColTest>0 ){
      int endDistinctTest = sqlite3VdbeMakeLabel(pParse);
      int *aGotoChng;               /* Array of jump instruction addresses */
      aGotoChng = sqlite3DbMallocRawNN(db, sizeof(int)*nColTest);

        sqlite3VdbeAddOp2(v, OP_NotNull, regPrev, endDistinctTest);
        VdbeCoverage(v);
      }
      for(i=0; i<nColTest; i++){
        char *pColl = (char*)sqlite3LocateCollSeq(pParse, pIdx->azColl[i]);
        sqlite3VdbeAddOp2(v, OP_Integer, i, regChng);
        sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, i, regTemp);
        VdbeComment((v, "%s.column(%d)", pIdx->zName, i));
        aGotoChng[i] = 
        sqlite3VdbeAddOp4(v, OP_Ne, regTemp, 0, regPrev+i, pColl, P4_COLLSEQ);
        sqlite3VdbeChangeP5(v, SQLITE_NULLEQ);
        VdbeCoverage(v);
      }
      sqlite3VdbeAddOp2(v, OP_Integer, nColTest, regChng);
      sqlite3VdbeGoto(v, endDistinctTest);
  
  
      /*
      **  chng_addr_0:
      **   regPrev(0) = idx(0)
      **  chng_addr_1:
      **   regPrev(1) = idx(1)
      **  ...
      */
      sqlite3VdbeJumpHere(v, addrNextRow-1);
      for(i=0; i<nColTest; i++){
        sqlite3VdbeJumpHere(v, aGotoChng[i]);
        sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, i, regPrev+i);
        VdbeComment((v, "%s.column(%d)", pIdx->zName, i));
      }
      sqlite3VdbeResolveLabel(v, endDistinctTest);
      sqlite3DbFree(db, aGotoChng);
    }
  
    /*
    **  chng_addr_N:
    **   regRowid = idx(rowid)            // STAT4 only
    **   stat_push(P, regChng, regRowid)  // 3rd parameter STAT4 only
    **   Next csr
    **   if !eof(csr) goto next_row;
    */
#ifdef SQLITE_ENABLE_STAT4
    if( OptimizationEnabled(db, SQLITE_Stat4) ){
      assert( regRowid==(regStat+2) );
      if( HasRowid(pTab) ){
        sqlite3VdbeAddOp2(v, OP_IdxRowid, iIdxCur, regRowid);
      }else{
        Index *pPk = sqlite3PrimaryKeyIndex(pIdx->pTable);
        int j, k, regKey;
        regKey = sqlite3GetTempRange(pParse, pPk->nKeyCol);
        for(j=0; j<pPk->nKeyCol; j++){
          k = sqlite3TableColumnToIndex(pIdx, pPk->aiColumn[j]);
          assert( k>=0 && k<pIdx->nColumn );
          sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, k, regKey+j);
          VdbeComment((v, "%s.column(%d)", pIdx->zName, i));
        }
        sqlite3VdbeAddOp3(v, OP_MakeRecord, regKey, pPk->nKeyCol, regRowid);
        sqlite3ReleaseTempRange(pParse, regKey, pPk->nKeyCol);
      }
    }
#endif
    assert( regChng==(regStat+1) );
    {
      sqlite3VdbeAddFunctionCall(pParse, 1, regStat, regTemp, 2+IsStat4,
                                 &statPushFuncdef, 0);
      if( db->nAnalysisLimit ){
        int j1, j2, j3;
        j1 = sqlite3VdbeAddOp1(v, OP_IsNull, regTemp); VdbeCoverage(v);
        j2 = sqlite3VdbeAddOp1(v, OP_If, regTemp); VdbeCoverage(v);
        j3 = sqlite3VdbeAddOp4Int(v, OP_SeekGT, iIdxCur, 0, regPrev, 1);
        VdbeCoverage(v);
        sqlite3VdbeJumpHere(v, j1);
        sqlite3VdbeAddOp2(v, OP_Next, iIdxCur, addrNextRow); VdbeCoverage(v);
        sqlite3VdbeJumpHere(v, j2);
        sqlite3VdbeJumpHere(v, j3);
      }else{
        sqlite3VdbeAddOp2(v, OP_Next, iIdxCur, addrNextRow); VdbeCoverage(v);
      }
    }

    /* Add the entry to the stat1 table. */
    callStatGet(pParse, regStat, STAT_GET_STAT1, regStat1);
    assert( "BBB"[0]==SQLITE_AFF_TEXT );
    sqlite3VdbeAddOp4(v, OP_MakeRecord, regTabname, 3, regTemp, "BBB", 0);
    sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur, regNewRowid);
    sqlite3VdbeAddOp3(v, OP_Insert, iStatCur, regTemp, regNewRowid);
#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
    sqlite3VdbeChangeP4(v, -1, (char*)pStat1, P4_TABLE);
#endif
    sqlite3VdbeChangeP5(v, OPFLAG_APPEND);

    /* Add the entries to the stat4 table. */
#ifdef SQLITE_ENABLE_STAT4

    if( OptimizationEnabled(db, SQLITE_Stat4) && db->nAnalysisLimit==0 ){
      int regEq = regStat1;
      int regLt = regStat1+1;
      int regDLt = regStat1+2;
      int regSample = regStat1+3;
      int regCol = regStat1+4;
      int regSampleRowid = regCol + nCol;
      int addrNext;
      int addrIsNull;
      u8 seekOp = HasRowid(pTab) ? OP_NotExists : OP_NotFound;

      pParse->nMem = MAX(pParse->nMem, regCol+nCol);

      addrNext = sqlite3VdbeCurrentAddr(v);
      callStatGet(pParse, regStat, STAT_GET_ROWID, regSampleRowid);
      addrIsNull = sqlite3VdbeAddOp1(v, OP_IsNull, regSampleRowid);
      VdbeCoverage(v);
      callStatGet(pParse, regStat, STAT_GET_NEQ, regEq);
      callStatGet(pParse, regStat, STAT_GET_NLT, regLt);
      callStatGet(pParse, regStat, STAT_GET_NDLT, regDLt);
      sqlite3VdbeAddOp4Int(v, seekOp, iTabCur, addrNext, regSampleRowid, 0);
      VdbeCoverage(v);
      for(i=0; i<nCol; i++){
        sqlite3ExprCodeLoadIndexColumn(pParse, pIdx, iTabCur, i, regCol+i);
      }
      sqlite3VdbeAddOp3(v, OP_MakeRecord, regCol, nCol, regSample);
      sqlite3VdbeAddOp3(v, OP_MakeRecord, regTabname, 6, regTemp);

  const char *(*filename_database)(const char*);
  const char *(*filename_journal)(const char*);
  const char *(*filename_wal)(const char*);
  /* Version 3.32.0 and later */
  char *(*create_filename)(const char*,const char*,const char*,
                           int,const char**);
  void (*free_filename)(char*);
  sqlite3_file *(*database_file_object)(const char*);
};

/*
** This is the function signature used for all extension entry points.  It
** is also defined in the file "loadext.c".
*/
typedef int (*sqlite3_loadext_entry)(

#define sqlite3_uri_key                sqlite3_api->uri_key
#define sqlite3_filename_database      sqlite3_api->filename_database
#define sqlite3_filename_journal       sqlite3_api->filename_journal
#define sqlite3_filename_wal           sqlite3_api->filename_wal
/* Version 3.32.0 and later */
#define sqlite3_create_filename        sqlite3_api->create_filename
#define sqlite3_free_filename          sqlite3_api->free_filename
#define sqlite3_database_file_object   sqlite3_api->database_file_object
#endif /* !defined(SQLITE_CORE) && !defined(SQLITE_OMIT_LOAD_EXTENSION) */

#if !defined(SQLITE_CORE) && !defined(SQLITE_OMIT_LOAD_EXTENSION)
  /* This case when the file really is being compiled as a loadable 
  ** extension */
# define SQLITE_EXTENSION_INIT1     const sqlite3_api_routines *sqlite3_api=0;
# define SQLITE_EXTENSION_INIT2(v)  sqlite3_api=v;

  sqlite3_uri_key,
  sqlite3_filename_database,
  sqlite3_filename_journal,
  sqlite3_filename_wal,
  /* Version 3.32.0 and later */
  sqlite3_create_filename,
  sqlite3_free_filename,
  sqlite3_database_file_object,
};

/* True if x is the directory separator character
*/
#if SQLITE_OS_WIN
# define DirSep(X)  ((X)=='/'||(X)=='\\')
#else
# define DirSep(X)  ((X)=='/')
#endif

/*
** Attempt to load an SQLite extension library contained in the file
** zFile.  The entry point is zProc.  zProc may be 0 in which case a
** default entry point name (sqlite3_extension_init) is used.  Use
** of the default name is recommended.
**

    int ncFile = sqlite3Strlen30(zFile);
    zAltEntry = sqlite3_malloc64(ncFile+30);
    if( zAltEntry==0 ){
      sqlite3OsDlClose(pVfs, handle);
      return SQLITE_NOMEM_BKPT;
    }
    memcpy(zAltEntry, "sqlite3_", 8);
    for(iFile=ncFile-1; iFile>=0 && !DirSep(zFile[iFile]); iFile--){}
    iFile++;
    if( sqlite3_strnicmp(zFile+iFile, "lib", 3)==0 ) iFile += 3;
    for(iEntry=8; (c = zFile[iFile])!=0 && c!='.'; iFile++){
      if( sqlite3Isalpha(c) ){
        zAltEntry[iEntry++] = (char)sqlite3UpperToLower[(unsigned)c];
      }
    }

** This file is automatically generated by the script at
** ../tool/mkpragmatab.tcl.  To update the set of pragmas, edit
** that script and rerun it.
*/

/* The various pragma types */
#define PragTyp_ACTIVATE_EXTENSIONS            0
#define PragTyp_ANALYSIS_LIMIT                 1
#define PragTyp_HEADER_VALUE                   2
#define PragTyp_AUTO_VACUUM                    3
#define PragTyp_FLAG                           4
#define PragTyp_BUSY_TIMEOUT                   5
#define PragTyp_CACHE_SIZE                     6
#define PragTyp_CACHE_SPILL                    7
#define PragTyp_CASE_SENSITIVE_LIKE            8
#define PragTyp_COLLATION_LIST                 9
#define PragTyp_COMPILE_OPTIONS               10
#define PragTyp_DATA_STORE_DIRECTORY          11
#define PragTyp_DATABASE_LIST                 12
#define PragTyp_DEFAULT_CACHE_SIZE            13
#define PragTyp_ENCODING                      14
#define PragTyp_FOREIGN_KEY_CHECK             15
#define PragTyp_FOREIGN_KEY_LIST              16
#define PragTyp_FUNCTION_LIST                 17
#define PragTyp_HARD_HEAP_LIMIT               18
#define PragTyp_INCREMENTAL_VACUUM            19
#define PragTyp_INDEX_INFO                    20
#define PragTyp_INDEX_LIST                    21
#define PragTyp_INTEGRITY_CHECK               22
#define PragTyp_JOURNAL_MODE                  23
#define PragTyp_JOURNAL_SIZE_LIMIT            24
#define PragTyp_LOCK_PROXY_FILE               25
#define PragTyp_LOCKING_MODE                  26
#define PragTyp_PAGE_COUNT                    27
#define PragTyp_MMAP_SIZE                     28
#define PragTyp_MODULE_LIST                   29
#define PragTyp_OPTIMIZE                      30
#define PragTyp_PAGE_SIZE                     31
#define PragTyp_PRAGMA_LIST                   32
#define PragTyp_SECURE_DELETE                 33
#define PragTyp_SHRINK_MEMORY                 34
#define PragTyp_SOFT_HEAP_LIMIT               35
#define PragTyp_SYNCHRONOUS                   36
#define PragTyp_TABLE_INFO                    37
#define PragTyp_TEMP_STORE                    38
#define PragTyp_TEMP_STORE_DIRECTORY          39
#define PragTyp_THREADS                       40
#define PragTyp_WAL_AUTOCHECKPOINT            41
#define PragTyp_WAL_CHECKPOINT                42
#define PragTyp_LOCK_STATUS                   43
#define PragTyp_STATS                         44

/* Property flags associated with various pragma. */
#define PragFlg_NeedSchema 0x01 /* Force schema load before running */
#define PragFlg_NoColumns  0x02 /* OP_ResultRow called with zero columns */
#define PragFlg_NoColumns1 0x04 /* zero columns if RHS argument is present */
#define PragFlg_ReadOnly   0x08 /* Read-only HEADER_VALUE */
#define PragFlg_Result0    0x10 /* Acts as query when no argument */

#if defined(SQLITE_ENABLE_CEROD)
 {/* zName:     */ "activate_extensions",
  /* ePragTyp:  */ PragTyp_ACTIVATE_EXTENSIONS,
  /* ePragFlg:  */ 0,
  /* ColNames:  */ 0, 0,
  /* iArg:      */ 0 },
#endif
 {/* zName:     */ "analysis_limit",
  /* ePragTyp:  */ PragTyp_ANALYSIS_LIMIT,
  /* ePragFlg:  */ PragFlg_Result0,
  /* ColNames:  */ 0, 0,
  /* iArg:      */ 0 },
#if !defined(SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS)
 {/* zName:     */ "application_id",
  /* ePragTyp:  */ PragTyp_HEADER_VALUE,
  /* ePragFlg:  */ PragFlg_NoColumns1|PragFlg_Result0,
  /* ColNames:  */ 0, 0,
  /* iArg:      */ BTREE_APPLICATION_ID },
#endif

 {/* zName:     */ "writable_schema",
  /* ePragTyp:  */ PragTyp_FLAG,
  /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,
  /* ColNames:  */ 0, 0,
  /* iArg:      */ SQLITE_WriteSchema|SQLITE_NoSchemaError },
#endif
};
/* Number of pragmas: 67 on by default, 77 total. */

/************** End of pragma.h **********************************************/
/************** Continuing where we left off in pragma.c *********************/

/*
** Interpret the given string as a safety level.  Return 0 for OFF,
** 1 for ON or NORMAL, 2 for FULL, and 3 for EXTRA.  Return 1 for an empty or 

            }
            sqlite3VdbeJumpHere(v, jmp4);
            sqlite3ResolvePartIdxLabel(pParse, jmp3);
          }
        }
        sqlite3VdbeAddOp2(v, OP_Next, iDataCur, loopTop); VdbeCoverage(v);
        sqlite3VdbeJumpHere(v, loopTop-1);

        if( !isQuick ){
          sqlite3VdbeLoadString(v, 2, "wrong # of entries in index ");
          for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
            if( pPk==pIdx ) continue;
            sqlite3VdbeAddOp2(v, OP_Count, iIdxCur+j, 3);
            addr = sqlite3VdbeAddOp3(v, OP_Eq, 8+j, 0, 3); VdbeCoverage(v);
            sqlite3VdbeChangeP5(v, SQLITE_NOTNULL);
            sqlite3VdbeLoadString(v, 4, pIdx->zName);
            sqlite3VdbeAddOp3(v, OP_Concat, 4, 2, 3);
            integrityCheckResultRow(v);
            sqlite3VdbeJumpHere(v, addr);
          }
        }

      } 
    }
    {
      static const int iLn = VDBE_OFFSET_LINENO(2);
      static const VdbeOpList endCode[] = {
        { OP_AddImm,      1, 0,        0},    /* 0 */
        { OP_IfNotZero,   1, 4,        0},    /* 1 */

     && N>=0
    ){
      sqlite3_limit(db, SQLITE_LIMIT_WORKER_THREADS, (int)(N&0x7fffffff));
    }
    returnSingleInt(v, sqlite3_limit(db, SQLITE_LIMIT_WORKER_THREADS, -1));
    break;
  }

  /*
  **   PRAGMA analysis_limit
  **   PRAGMA analysis_limit = N
  **
  ** Configure the maximum number of rows that ANALYZE will examine
  ** in each index that it looks at.  Return the new limit.
  */
  case PragTyp_ANALYSIS_LIMIT: {
    sqlite3_int64 N;
    if( zRight
     && sqlite3DecOrHexToI64(zRight, &N)==SQLITE_OK
     && N>=0
    ){
      db->nAnalysisLimit = (int)(N&0x7fffffff);
    }
    returnSingleInt(v, db->nAnalysisLimit);
    break;
  }

#if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)
  /*
  ** Report the current state of file logs for all databases
  */
  case PragTyp_LOCK_STATUS: {
    static const char *const azLockName[] = {

      }else{
        sqlite3 *db = pSubst->pParse->db;
        if( pSubst->isLeftJoin && pCopy->op!=TK_COLUMN ){
          memset(&ifNullRow, 0, sizeof(ifNullRow));
          ifNullRow.op = TK_IF_NULL_ROW;
          ifNullRow.pLeft = pCopy;
          ifNullRow.iTable = pSubst->iNewTable;
          ifNullRow.flags = EP_Skip;
          pCopy = &ifNullRow;
        }
        testcase( ExprHasProperty(pCopy, EP_Subquery) );
        pNew = sqlite3ExprDup(db, pCopy, 0);
        if( pNew && pSubst->isLeftJoin ){
          ExprSetProperty(pNew, EP_CanBeNull);
        }

      resetAccumulator(pParse, &sAggInfo);
      sqlite3VdbeAddOp2(v, OP_Integer, 0, iUseFlag);
      VdbeComment((v, "indicate accumulator empty"));
      sqlite3VdbeAddOp1(v, OP_Return, regReset);
     
    } /* endif pGroupBy.  Begin aggregate queries without GROUP BY: */
    else {

      Table *pTab;
      if( (pTab = isSimpleCount(p, &sAggInfo))!=0 ){
        /* If isSimpleCount() returns a pointer to a Table structure, then
        ** the SQL statement is of the form:
        **
        **   SELECT count(*) FROM <tbl>
        **

        sqlite3VdbeAddOp4Int(v, OP_OpenRead, iCsr, iRoot, iDb, 1);
        if( pKeyInfo ){
          sqlite3VdbeChangeP4(v, -1, (char *)pKeyInfo, P4_KEYINFO);
        }
        sqlite3VdbeAddOp2(v, OP_Count, iCsr, sAggInfo.aFunc[0].iMem);
        sqlite3VdbeAddOp1(v, OP_Close, iCsr);
        explainSimpleCount(pParse, pTab, pBest);
      }else{


        int regAcc = 0;           /* "populate accumulators" flag */

        /* If there are accumulator registers but no min() or max() functions
        ** without FILTER clauses, allocate register regAcc. Register regAcc
        ** will contain 0 the first time the inner loop runs, and 1 thereafter.
        ** The code generated by updateAccumulator() uses this to ensure
        ** that the accumulator registers are (a) updated only once if

}  /* extern "C" */
#endif  /* __cplusplus */


/************** End of sqliteicu.h *******************************************/
/************** Continuing where we left off in main.c ***********************/
#endif

/*
** This is an extension initializer that is a no-op and always
** succeeds, except that it fails if the fault-simulation is set
** to 500.
*/
static int sqlite3TestExtInit(sqlite3 *db){
  (void)db;
  return sqlite3FaultSim(500);
}


/*
** Forward declarations of external module initializer functions
** for modules that need them.
*/
#ifdef SQLITE_ENABLE_FTS1
SQLITE_PRIVATE int sqlite3Fts1Init(sqlite3*);
#endif
#ifdef SQLITE_ENABLE_FTS2
SQLITE_PRIVATE int sqlite3Fts2Init(sqlite3*);
#endif
#ifdef SQLITE_ENABLE_FTS5
SQLITE_PRIVATE int sqlite3Fts5Init(sqlite3*);
#endif
#ifdef SQLITE_ENABLE_JSON1
SQLITE_PRIVATE int sqlite3Json1Init(sqlite3*);
#endif
#ifdef SQLITE_ENABLE_STMTVTAB
SQLITE_PRIVATE int sqlite3StmtVtabInit(sqlite3*);
#endif

/*
** An array of pointers to extension initializer functions for
** built-in extensions.
*/
static int (*const sqlite3BuiltinExtensions[])(sqlite3*) = {
#ifdef SQLITE_ENABLE_FTS1
  sqlite3Fts1Init,
#endif
#ifdef SQLITE_ENABLE_FTS2
  sqlite3Fts2Init,
#endif
#ifdef SQLITE_ENABLE_FTS3
  sqlite3Fts3Init,
#endif
#ifdef SQLITE_ENABLE_FTS5
  sqlite3Fts5Init,
#endif
#if defined(SQLITE_ENABLE_ICU) || defined(SQLITE_ENABLE_ICU_COLLATIONS)
  sqlite3IcuInit,
#endif
#ifdef SQLITE_ENABLE_RTREE
  sqlite3RtreeInit,
#endif
#ifdef SQLITE_ENABLE_DBPAGE_VTAB
  sqlite3DbpageRegister,
#endif
#ifdef SQLITE_ENABLE_DBSTAT_VTAB
  sqlite3DbstatRegister,
#endif
  sqlite3TestExtInit,
#ifdef SQLITE_ENABLE_JSON1
  sqlite3Json1Init,
#endif
#ifdef SQLITE_ENABLE_STMTVTAB
  sqlite3StmtVtabInit,
#endif
#ifdef SQLITE_ENABLE_BYTECODE_VTAB
  sqlite3VdbeBytecodeVtabInit,
#endif
};

#ifndef SQLITE_AMALGAMATION
/* IMPLEMENTATION-OF: R-46656-45156 The sqlite3_version[] string constant
** contains the text of SQLITE_VERSION macro. 
*/
SQLITE_API const char sqlite3_version[] = SQLITE_VERSION;
#endif

  const char *zVfs       /* Name of the VFS to use */
){
  sqlite3 *db;                    /* Store allocated handle here */
  int rc;                         /* Return code */
  int isThreadsafe;               /* True for threadsafe connections */
  char *zOpen = 0;                /* Filename argument to pass to BtreeOpen() */
  char *zErrMsg = 0;              /* Error message from sqlite3ParseUri() */
  int i;                          /* Loop counter */

#ifdef SQLITE_ENABLE_API_ARMOR
  if( ppDb==0 ) return SQLITE_MISUSE_BKPT;
#endif
  *ppDb = 0;
#ifndef SQLITE_OMIT_AUTOINIT
  rc = sqlite3_initialize();

  ** database schema yet. This is delayed until the first time the database
  ** is accessed.
  */
  sqlite3Error(db, SQLITE_OK);
  sqlite3RegisterPerConnectionBuiltinFunctions(db);
  rc = sqlite3_errcode(db);



  /* Load compiled-in extensions */

  for(i=0; rc==SQLITE_OK && i<ArraySize(sqlite3BuiltinExtensions); i++){
    rc = sqlite3BuiltinExtensions[i](db);
  }


  /* Load automatic extensions - extensions that have been registered
  ** using the sqlite3_automatic_extension() API.
  */
  if( rc==SQLITE_OK ){
    sqlite3AutoLoadExtensions(db);
    rc = sqlite3_errcode(db);
    if( rc!=SQLITE_OK ){
      goto opendb_out;
    }
  }

























































#ifdef SQLITE_ENABLE_INTERNAL_FUNCTIONS
  /* Testing use only!!! The -DSQLITE_ENABLE_INTERNAL_FUNCTIONS=1 compile-time
  ** option gives access to internal functions by default.  
  ** Testing use only!!! */
  db->mDbFlags |= DBFLAG_InternalFunc;
#endif

SQLITE_PRIVATE int sqlite3Fts3VarintLen(sqlite3_uint64);
SQLITE_PRIVATE void sqlite3Fts3Dequote(char *);
SQLITE_PRIVATE void sqlite3Fts3DoclistPrev(int,char*,int,char**,sqlite3_int64*,int*,u8*);
SQLITE_PRIVATE int sqlite3Fts3EvalPhraseStats(Fts3Cursor *, Fts3Expr *, u32 *);
SQLITE_PRIVATE int sqlite3Fts3FirstFilter(sqlite3_int64, char *, int, char *);
SQLITE_PRIVATE void sqlite3Fts3CreateStatTable(int*, Fts3Table*);
SQLITE_PRIVATE int sqlite3Fts3EvalTestDeferred(Fts3Cursor *pCsr, int *pRc);
SQLITE_PRIVATE int sqlite3Fts3ReadInt(const char *z, int *pnOut);

/* fts3_tokenizer.c */
SQLITE_PRIVATE const char *sqlite3Fts3NextToken(const char *, int *);
SQLITE_PRIVATE int sqlite3Fts3InitHashTable(sqlite3 *, Fts3Hash *, const char *);
SQLITE_PRIVATE int sqlite3Fts3InitTokenizer(Fts3Hash *pHash, const char *, 
    sqlite3_tokenizer **, char **
);

  }
  if( p->zLanguageid ){
    fts3Appendf(pRc, &zRet, ", ?");
  }
  sqlite3_free(zFree);
  return zRet;
}

/*
** Buffer z contains a positive integer value encoded as utf-8 text.
** Decode this value and store it in *pnOut, returning the number of bytes
** consumed. If an overflow error occurs return a negative value.
*/
SQLITE_PRIVATE int sqlite3Fts3ReadInt(const char *z, int *pnOut){
  u64 iVal = 0;
  int i;
  for(i=0; z[i]>='0' && z[i]<='9'; i++){
    iVal = iVal*10 + (z[i] - '0');
    if( iVal>0x7FFFFFFF ) return -1;
  }
  *pnOut = (int)iVal;
  return i;
}

/*
** This function interprets the string at (*pp) as a non-negative integer
** value. It reads the integer and sets *pnOut to the value read, then 
** sets *pp to point to the byte immediately following the last byte of
** the integer value.
**
** Only decimal digits ('0'..'9') may be part of an integer value. 
**
** If *pp does not being with a decimal digit SQLITE_ERROR is returned and
** the output value undefined. Otherwise SQLITE_OK is returned.
**
** This function is used when parsing the "prefix=" FTS4 parameter.
*/
static int fts3GobbleInt(const char **pp, int *pnOut){
  const int MAX_NPREFIX = 10000000;

  int nInt = 0;                   /* Output value */
  int nByte;

  nByte = sqlite3Fts3ReadInt(*pp, &nInt);
  if( nInt>MAX_NPREFIX ){
    nInt = 0;

  }
  if( nByte==0 ){
    return SQLITE_ERROR;
  }

  *pnOut = nInt;
  *pp += nByte;
  return SQLITE_OK;
}

/*
** This function is called to allocate an array of Fts3Index structures
** representing the indexes maintained by the current FTS table. FTS tables
** always maintain the main "terms" index, but may also maintain one or

      int nKey = pKey->n;
      char cNext;

      /* If this is a "NEAR" keyword, check for an explicit nearness. */
      if( pKey->eType==FTSQUERY_NEAR ){
        assert( nKey==4 );
        if( zInput[4]=='/' && zInput[5]>='0' && zInput[5]<='9' ){


          nKey += 1+sqlite3Fts3ReadInt(&zInput[nKey+1], &nNear);

        }
      }

      /* At this point this is probably a keyword. But for that to be true,
      ** the next byte must contain either whitespace, an open or close
      ** parenthesis, a quote character, or EOF. 
      */

  i64 *piEndBlock,
  i64 *pnByte
){
  const unsigned char *zText = sqlite3_column_text(pStmt, iCol);
  if( zText ){
    int i;
    int iMul = 1;
    u64 iVal = 0;
    for(i=0; zText[i]>='0' && zText[i]<='9'; i++){
      iVal = iVal*10 + (zText[i] - '0');
    }
    *piEndBlock = (i64)iVal;
    while( zText[i]==' ' ) i++;
    iVal = 0;
    if( zText[i]=='-' ){
      i++;
      iMul = -1;
    }
    for(/* no-op */; zText[i]>='0' && zText[i]<='9'; i++){
      iVal = iVal*10 + (zText[i] - '0');
    }
    *pnByte = ((i64)iVal * (i64)iMul);
  }
}


/*
** A segment of size nByte bytes has just been written to absolute level
** iAbsLevel. Promote any segments that should be promoted as a result.

static void fts5SourceIdFunc(
  sqlite3_context *pCtx,          /* Function call context */
  int nArg,                       /* Number of args */
  sqlite3_value **apUnused        /* Function arguments */
){
  assert( nArg==0 );
  UNUSED_PARAM2(nArg, apUnused);
  sqlite3_result_text(pCtx, "fts5: 2020-05-04 19:52:00 8eee591d3cb9fadfd5cac5543bd66ef9cb371a72d3ad3241fb3bfd67fb216eda", -1, SQLITE_TRANSIENT);
}

/*
** Return true if zName is the extension on one of the shadow tables used
** by this module.
*/
static int fts5ShadowName(const char *zName){

      sqlite3_result_int(ctx, sqlite3_stmt_readonly(pCur->pStmt));
      break;
    }
    case STMT_COLUMN_BUSY: {
      sqlite3_result_int(ctx, sqlite3_stmt_busy(pCur->pStmt));
      break;
    }
    default: {
      assert( i==STMT_COLUMN_MEM );
      i = SQLITE_STMTSTATUS_MEMUSED + 
            STMT_COLUMN_NSCAN - SQLITE_STMTSTATUS_FULLSCAN_STEP;
      /* Fall thru */
    }
    case STMT_COLUMN_NSCAN:
    case STMT_COLUMN_NSORT:
    case STMT_COLUMN_NAIDX:

#endif
  return rc;
}
#endif /* SQLITE_CORE */
#endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_STMTVTAB) */

/************** End of stmt.c ************************************************/
#if __LINE__!=229293
#undef SQLITE_SOURCE_ID
#define SQLITE_SOURCE_ID      "2020-05-04 19:52:00 8eee591d3cb9fadfd5cac5543bd66ef9cb371a72d3ad3241fb3bfd67fb21alt2"
#endif
/* Return the source-id for this library */
SQLITE_API const char *sqlite3_sourceid(void){ return SQLITE_SOURCE_ID; }
/************************** End of sqlite3.c ******************************/

**
** See also: [sqlite3_libversion()],
** [sqlite3_libversion_number()], [sqlite3_sourceid()],
** [sqlite_version()] and [sqlite_source_id()].
*/
#define SQLITE_VERSION        "3.32.0"
#define SQLITE_VERSION_NUMBER 3032000
#define SQLITE_SOURCE_ID      "2020-05-04 19:52:00 8eee591d3cb9fadfd5cac5543bd66ef9cb371a72d3ad3241fb3bfd67fb216eda"

/*
** CAPI3REF: Run-Time Library Version Numbers
** KEYWORDS: sqlite3_version sqlite3_sourceid
**
** These interfaces provide the same information as the [SQLITE_VERSION],
** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros

**
** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors
** for the [sqlite3] object.
** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if
** the [sqlite3] object is successfully destroyed and all associated
** resources are deallocated.
**
** Ideally, applications should [sqlite3_finalize | finalize] all
** [prepared statements], [sqlite3_blob_close | close] all [BLOB handles], and 
** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated
** with the [sqlite3] object prior to attempting to close the object.
** ^If the database connection is associated with unfinalized prepared
** statements, BLOB handlers, and/or unfinished sqlite3_backup objects then
** sqlite3_close() will leave the database connection open and return
** [SQLITE_BUSY]. ^If sqlite3_close_v2() is called with unfinalized prepared
** statements, unclosed BLOB handlers, and/or unfinished sqlite3_backups,
** it returns [SQLITE_OK] regardless, but instead of deallocating the database
** connection immediately, it marks the database connection as an unusable
** "zombie" and makes arrangements to automatically deallocate the database
** connection after all prepared statements are finalized, all BLOB handles
** are closed, and all backups have finished. The sqlite3_close_v2() interface
** is intended for use with host languages that are garbage collected, and
** where the order in which destructors are called is arbitrary.










**
** ^If an [sqlite3] object is destroyed while a transaction is open,
** the transaction is automatically rolled back.
**
** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)]
** must be either a NULL
** pointer or an [sqlite3] object pointer obtained

#define SQLITE_IOERR_GETTEMPPATH       (SQLITE_IOERR | (25<<8))
#define SQLITE_IOERR_CONVPATH          (SQLITE_IOERR | (26<<8))
#define SQLITE_IOERR_VNODE             (SQLITE_IOERR | (27<<8))
#define SQLITE_IOERR_AUTH              (SQLITE_IOERR | (28<<8))
#define SQLITE_IOERR_BEGIN_ATOMIC      (SQLITE_IOERR | (29<<8))
#define SQLITE_IOERR_COMMIT_ATOMIC     (SQLITE_IOERR | (30<<8))
#define SQLITE_IOERR_ROLLBACK_ATOMIC   (SQLITE_IOERR | (31<<8))
#define SQLITE_IOERR_DATA              (SQLITE_IOERR | (32<<8))
#define SQLITE_LOCKED_SHAREDCACHE      (SQLITE_LOCKED |  (1<<8))
#define SQLITE_LOCKED_VTAB             (SQLITE_LOCKED |  (2<<8))
#define SQLITE_BUSY_RECOVERY           (SQLITE_BUSY   |  (1<<8))
#define SQLITE_BUSY_SNAPSHOT           (SQLITE_BUSY   |  (2<<8))
#define SQLITE_CANTOPEN_NOTEMPDIR      (SQLITE_CANTOPEN | (1<<8))
#define SQLITE_CANTOPEN_ISDIR          (SQLITE_CANTOPEN | (2<<8))
#define SQLITE_CANTOPEN_FULLPATH       (SQLITE_CANTOPEN | (3<<8))

** omits changes made by other database connections.  The
** [PRAGMA data_version] command provides a mechanism to detect changes to
** a single attached database that occur due to other database connections,
** but omits changes implemented by the database connection on which it is
** called.  This file control is the only mechanism to detect changes that
** happen either internally or externally and that are associated with
** a particular attached database.
**
** <li>[[SQLITE_FCNTL_CKPT_START]]
** The [SQLITE_FCNTL_CKPT_START] opcode is invoked from within a checkpoint
** in wal mode before the client starts to copy pages from the wal
** file to the database file.
**
** <li>[[SQLITE_FCNTL_CKPT_DONE]]
** The [SQLITE_FCNTL_CKPT_DONE] opcode is invoked from within a checkpoint
** in wal mode after the client has finished copying pages from the wal
** file to the database file, but before the *-shm file is updated to
** record the fact that the pages have been checkpointed.
** </ul>

#define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE    32
#define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE  33
#define SQLITE_FCNTL_LOCK_TIMEOUT           34
#define SQLITE_FCNTL_DATA_VERSION           35
#define SQLITE_FCNTL_SIZE_LIMIT             36
#define SQLITE_FCNTL_CKPT_DONE              37
#define SQLITE_FCNTL_RESERVE_BYTES          38
#define SQLITE_FCNTL_CKPT_START             39

/* deprecated names */
#define SQLITE_GET_LOCKPROXYFILE      SQLITE_FCNTL_GET_LOCKPROXYFILE
#define SQLITE_SET_LOCKPROXYFILE      SQLITE_FCNTL_SET_LOCKPROXYFILE
#define SQLITE_LAST_ERRNO             SQLITE_FCNTL_LAST_ERRNO

/*
** CAPI3REF: Obtain Values For URI Parameters
**
** These are utility routines, useful to [VFS|custom VFS implementations],
** that check if a database file was a URI that contained a specific query 
** parameter, and if so obtains the value of that query parameter.
**
** The first parameter to these interfaces (hereafter referred to
** as F) must be one of:
** <ul>
** <li> A database filename pointer created by the SQLite core and
** passed into the xOpen() method of a VFS implemention, or
** <li> A filename obtained from [sqlite3_db_filename()], or
** <li> A new filename constructed using [sqlite3_create_filename()].
** </ul>
** If the F parameter is not one of the above, then the behavior is
** undefined and probably undesirable.  Older versions of SQLite were
** more tolerant of invalid F parameters than newer versions.
**
** If F is a suitable filename (as described in the previous paragraph)
** and if P is the name of the query parameter, then
** sqlite3_uri_parameter(F,P) returns the value of the P
** parameter if it exists or a NULL pointer if P does not appear as a 
** query parameter on F.  If P is a query parameter of F and it
** has no explicit value, then sqlite3_uri_parameter(F,P) returns
** a pointer to an empty string.
**

** return value from [sqlite3_db_filename()], then the result is
** undefined and is likely a memory access violation.
*/
SQLITE_API const char *sqlite3_filename_database(const char*);
SQLITE_API const char *sqlite3_filename_journal(const char*);
SQLITE_API const char *sqlite3_filename_wal(const char*);

/*
** CAPI3REF:  Database File Corresponding To A Journal
**
** ^If X is the name of a rollback or WAL-mode journal file that is
** passed into the xOpen method of [sqlite3_vfs], then 
** sqlite3_database_file_object(X) returns a pointer to the [sqlite3_file]
** object that represents the main database file.
**
** This routine is intended for use in custom [VFS] implementations
** only.  It is not a general-purpose interface.
** The argument sqlite3_file_object(X) must be a filename pointer that
** has been passed into [sqlite3_vfs].xOpen method where the 
** flags parameter to xOpen contains one of the bits
** [SQLITE_OPEN_MAIN_JOURNAL] or [SQLITE_OPEN_WAL].  Any other use
** of this routine results in undefined and probably undesirable
** behavior.
*/
SQLITE_API sqlite3_file *sqlite3_database_file_object(const char*);

/*
** CAPI3REF: Create and Destroy VFS Filenames
**
** These interfces are provided for use by [VFS shim] implementations and
** are not useful outside of that context.
**
** The sqlite3_create_filename(D,J,W,N,P) allocates memory to hold a version of

** pointer if N is zero.  None of the 2*N pointers in the P array may be
** NULL pointers and key pointers should not be empty strings.
** None of the D, J, or W parameters to sqlite3_create_filename(D,J,W,N,P) may
** be NULL pointers, though they can be empty strings.
**
** The sqlite3_free_filename(Y) routine releases a memory allocation
** previously obtained from sqlite3_create_filename().  Invoking
** sqlite3_free_filename(Y) where Y is a NULL pointer is a harmless no-op.
**
** If the Y parameter to sqlite3_free_filename(Y) is anything other
** than a NULL pointer or a pointer previously acquired from
** sqlite3_create_filename(), then bad things such as heap
** corruption or segfaults may occur. The value Y should be 
** used again after sqlite3_free_filename(Y) has been called.  This means
** that if the [sqlite3_vfs.xOpen()] method of a VFS has been called using Y,