SQLite

  $(TOP)/src/test_schema.c \
  $(TOP)/src/test_server.c \
  $(TOP)/src/test_superlock.c \
  $(TOP)/src/test_syscall.c \
  $(TOP)/src/test_tclvar.c \
  $(TOP)/src/test_thread.c \
  $(TOP)/src/test_vfs.c \
  $(TOP)/src/test_windirent.c \
  $(TOP)/src/test_wsd.c       \
  $(TOP)/ext/fts3/fts3_term.c \
  $(TOP)/ext/fts3/fts3_test.c \
  $(TOP)/ext/rbu/test_rbu.c 

# Statically linked extensions
#

  $(TOP)\src\test_schema.c \
  $(TOP)\src\test_server.c \
  $(TOP)\src\test_superlock.c \
  $(TOP)\src\test_syscall.c \
  $(TOP)\src\test_tclvar.c \
  $(TOP)\src\test_thread.c \
  $(TOP)\src\test_vfs.c \
  $(TOP)\src\test_windirent.c \
  $(TOP)\src\test_wsd.c \
  $(TOP)\ext\fts3\fts3_term.c \
  $(TOP)\ext\fts3\fts3_test.c \
  $(TOP)\ext\rbu\test_rbu.c

# Statically linked extensions
#

  char **pzErr                    /* OUT: Error message */
){
  int rc = SQLITE_OK;
  int nCmd = (int)strlen(zCmd);
  if( sqlite3_strnicmp("prefix", zCmd, nCmd)==0 ){
    const int nByte = sizeof(int) * FTS5_MAX_PREFIX_INDEXES;
    const char *p;
    int bFirst = 1;
    if( pConfig->aPrefix==0 ){



      pConfig->aPrefix = sqlite3Fts5MallocZero(&rc, nByte);
      if( rc ) return rc;
    }

    p = zArg;
    while( 1 ){
      int nPre = 0;





      while( p[0]==' ' ) p++;
      if( bFirst==0 && p[0]==',' ){
        p++;
        while( p[0]==' ' ) p++;
      }else if( p[0]=='\0' ){
        break;
      }
      if( p[0]<'0' || p[0]>'9' ){
        *pzErr = sqlite3_mprintf("malformed prefix=... directive");
        rc = SQLITE_ERROR;
        break;
      }

      if( pConfig->nPrefix==FTS5_MAX_PREFIX_INDEXES ){
        *pzErr = sqlite3_mprintf(
            "too many prefix indexes (max %d)", FTS5_MAX_PREFIX_INDEXES
        );
        rc = SQLITE_ERROR;
        break;
      }

      while( p[0]>='0' && p[0]<='9' && nPre<1000 ){
        nPre = nPre*10 + (p[0] - '0');
        p++;
      }

      if( rc==SQLITE_OK && (nPre<=0 || nPre>=1000) ){
        *pzErr = sqlite3_mprintf("prefix length out of range (max 999)");
        rc = SQLITE_ERROR;
        break;
      }

      pConfig->aPrefix[pConfig->nPrefix] = nPre;
      pConfig->nPrefix++;
      bFirst = 0;
    }
    assert( pConfig->nPrefix<=FTS5_MAX_PREFIX_INDEXES );
    return rc;
  }

  if( sqlite3_strnicmp("tokenize", zCmd, nCmd)==0 ){
    const char *p = (const char*)zArg;
    int nArg = (int)strlen(zArg) + 1;
    char **azArg = sqlite3Fts5MallocZero(&rc, sizeof(char*) * nArg);

#-------------------------------------------------------------------------
# Syntax errors in the prefix= option.
#
foreach {tn opt} {
  1 {prefix=x}  
  2 {prefix='x'}
  3 {prefix='$'}
  4 {prefix='1,2,'}
  5 {prefix=',1'}
} {
  set res [list 1 {malformed prefix=... directive}]
  do_catchsql_test 2.$tn "CREATE VIRTUAL TABLE f1 USING fts5(x, $opt)" $res
}

#-------------------------------------------------------------------------
# Syntax errors in the 'rank' option.

do_catchsql_test 5.3 {
  CREATE VIRTUAL TABLE yy USING fts5(x, [y]]);
} {1 {unrecognized token: "]"}}

#-------------------------------------------------------------------------
# Errors in prefix= directives.
#



do_catchsql_test 6.2 {
  CREATE VIRTUAL TABLE abc USING fts5(a, prefix='1, 2, 1001');
} {1 {prefix length out of range (max 999)}}
do_catchsql_test 6.3 {
  CREATE VIRTUAL TAbLE abc USING fts5(a, prefix='1, 2, 0000');
} {1 {prefix length out of range (max 999)}}
do_catchsql_test 6.4 {
  CREATE VIRTUAL TABLE abc USING fts5(a, prefix='1  , 1000000');
} {1 {prefix length out of range (max 999)}}

#-------------------------------------------------------------------------
# Duplicate tokenize= and other options.
#
do_catchsql_test 7.1 {
  CREATE VIRTUAL TABLE abc USING fts5(a, tokenize=porter, tokenize=ascii);
} {1 {multiple tokenize=... directives}}

do_execsql_test 9.3.4 {
  INSERT INTO abc(abc, rank) VALUES('crisismerge', 50000000);
} {}

do_catchsql_test 9.4.1 {
  INSERT INTO abc(abc, rank) VALUES('nosuchoption', 1);
} {1 {SQL logic error or missing database}}

#-------------------------------------------------------------------------
# Too many prefix indexes. Maximum allowed is 31.
#
foreach {tn spec} {
  1 {prefix="1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32"}
  2 {prefix="1 2 3 4", prefix="5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32"}
} {
  set sql "CREATE VIRTUAL TABLE xyz USING fts5(x, $spec)"
  do_catchsql_test 10.$tn $sql {1 {too many prefix indexes (max 31)}}
}

finish_test

  5 x {xb*}
  6 x {xc*}
} {
  set res [db eval "SELECT rowid FROM t5 WHERE gmatch($col, \$pattern)"]
  set query "$col : $pattern"
  do_execsql_test 6.$tn { SELECT rowid FROM t5($query) } $res
}

#-------------------------------------------------------------------------
# Check that the various ways of creating prefix indexes produce the
# same database on disk.
#
save_prng_state
foreach {tn create} {
  1 { CREATE VIRTUAL TABLE tt USING fts5(x, y, prefix="1,2,3") }
  2 { CREATE VIRTUAL TABLE tt USING fts5(x, y, prefix="1 2 3") }
  3 { CREATE VIRTUAL TABLE tt USING fts5(x, y, prefix=1, prefix=2, prefix=3) }
  4 { CREATE VIRTUAL TABLE tt USING fts5(x, y, prefix="1 2", prefix=3) }
} {
  execsql { DROP TABLE IF EXISTS tt }
  restore_prng_state
  execsql $create
  execsql {
    INSERT INTO tt VALUES('cc b ggg ccc aa eee hh', 'aa g b hh a e');
    INSERT INTO tt VALUES('cc bb cc gg j g cc', 'ii jjj ggg jjj cc cc');
    INSERT INTO tt VALUES('h eee cc h iii', 'aaa iii dd iii dd');
    INSERT INTO tt VALUES('jjj hh eee c e b gg', 'j bbb jj ddd jj');
    INSERT INTO tt VALUES('ii hhh aaa ff c hhh iii', 'j cc hh bb e');
    INSERT INTO tt VALUES('e fff hhh i aaa', 'g b aa gg c aa dd');
    INSERT INTO tt VALUES('i aaa ccc gg hhh aa h', 'j bbb bbb d ff');
    INSERT INTO tt VALUES('g f gg ff ff jjj d', 'jjj d j fff fff ee j');
    INSERT INTO tt VALUES('a cc e ccc jjj c', 'ccc iii d bb a eee g');
    INSERT INTO tt VALUES('jj hh hh bb bbb gg', 'j c jjj bb iii f');
    INSERT INTO tt VALUES('a ggg g cc ccc aa', 'jjj j j aaa c');
    INSERT INTO tt VALUES('ddd j dd b i', 'aaa bbb iii ggg ff ccc ddd');
    INSERT INTO tt VALUES('jj ii hh c ii h gg', 'hhh bbb ddd bbb hh g ggg');
    INSERT INTO tt VALUES('aa hhh ccc h ggg ccc', 'iii d jj a ff ii');
  }

  #db eval {SELECT rowid, fts5_decode(rowid, block) aS r FROM tt_data} {puts $r}

  if {$tn==1} {
    set ::checksum [execsql {SELECT md5sum(id, block) FROM tt_data}]
  } else {
    do_execsql_test 7.$tn {
      SELECT md5sum(id, block) FROM tt_data
    } [list $::checksum]
  }
}

finish_test

  $(TOP)/src/test_server.c \
  $(TOP)/src/test_sqllog.c \
  $(TOP)/src/test_superlock.c \
  $(TOP)/src/test_syscall.c \
  $(TOP)/src/test_tclvar.c \
  $(TOP)/src/test_thread.c \
  $(TOP)/src/test_vfs.c \
  $(TOP)/src/test_windirent.c \
  $(TOP)/src/test_wsd.c

# Extensions to be statically loaded.
#
TESTSRC += \
  $(TOP)/ext/misc/amatch.c \
  $(TOP)/ext/misc/closure.c \

  if( v==0 || NEVER(pTab==0) ){
    return;
  }
  if( pTab->tnum==0 ){
    /* Do not gather statistics on views or virtual tables */
    return;
  }
  if( sqlite3_strlike("sqlite_%", pTab->zName, 0)==0 ){
    /* Do not gather statistics on system tables */
    return;
  }
  assert( sqlite3BtreeHoldsAllMutexes(db) );
  iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
  assert( iDb>=0 );
  assert( sqlite3SchemaMutexHeld(db, iDb, 0) );

#include "sqliteInt.h"

/* Size of the Bitvec structure in bytes. */
#define BITVEC_SZ        512

/* Round the union size down to the nearest pointer boundary, since that's how 
** it will be aligned within the Bitvec struct. */
#define BITVEC_USIZE \
    (((BITVEC_SZ-(3*sizeof(u32)))/sizeof(Bitvec*))*sizeof(Bitvec*))

/* Type of the array "element" for the bitmap representation. 
** Should be a power of 2, and ideally, evenly divide into BITVEC_USIZE. 
** Setting this to the "natural word" size of your CPU may improve
** performance. */
#define BITVEC_TELEM     u8
/* Size, in bits, of the bitmap element. */

    if( zDbase ){
      sqlite3ErrorMsg(pParse, "%s: %s.%s", zMsg, zDbase, zName);
    }else{
      sqlite3ErrorMsg(pParse, "%s: %s", zMsg, zName);
    }
    pParse->checkSchema = 1;
  }






  return p;
}

/*
** Locate the table identified by *p.
**
** This is a wrapper around sqlite3LocateTable(). The difference between

}

/*
** Add the list of function arguments to the SrcList entry for a
** table-valued-function.
*/
void sqlite3SrcListFuncArgs(Parse *pParse, SrcList *p, ExprList *pList){
  if( p ){
    struct SrcList_item *pItem = &p->a[p->nSrc-1];
    assert( pItem->fg.notIndexed==0 );
    assert( pItem->fg.isIndexedBy==0 );
    assert( pItem->fg.isTabFunc==0 );
    pItem->u1.pFuncArg = pList;
    pItem->fg.isTabFunc = 1;
  }else{

  "IGNORE_AFP_LOCK_ERRORS",
#endif
#if SQLITE_IGNORE_FLOCK_LOCK_ERRORS
  "IGNORE_FLOCK_LOCK_ERRORS",
#endif
#ifdef SQLITE_INT64_TYPE
  "INT64_TYPE",
#endif
#ifdef SQLITE_LIKE_DOESNT_MATCH_BLOBS
  "LIKE_DOESNT_MATCH_BLOBS",
#endif
#if SQLITE_LOCK_TRACE
  "LOCK_TRACE",
#endif
#if defined(SQLITE_MAX_MMAP_SIZE) && !defined(SQLITE_MAX_MMAP_SIZE_xc)
  "MAX_MMAP_SIZE=" CTIMEOPT_VAL(SQLITE_MAX_MMAP_SIZE),
#endif

  */
  if( !ExprHasProperty(pExpr, EP_VarSelect) ){
    jmpIfDynamic = sqlite3CodeOnce(pParse); VdbeCoverage(v);
  }

#ifndef SQLITE_OMIT_EXPLAIN
  if( pParse->explain==2 ){
    char *zMsg = sqlite3MPrintf(pParse->db, "EXECUTE %s%s SUBQUERY %d",
        jmpIfDynamic>=0?"":"CORRELATED ",
        pExpr->op==TK_IN?"LIST":"SCALAR",
        pParse->iNextSelectId
    );
    sqlite3VdbeAddOp4(v, OP_Explain, pParse->iSelectId, 0, 0, zMsg, P4_DYNAMIC);
  }
#endif

  switch( pExpr->op ){
    case TK_IN: {

      return 1;
    }
    if( pB->op==TK_COLLATE && sqlite3ExprCompare(pA, pB->pLeft, iTab)<2 ){
      return 1;
    }
    return 2;
  }
  if( pA->op!=TK_COLUMN && pA->op!=TK_AGG_COLUMN && pA->u.zToken ){
    if( pA->op==TK_FUNCTION ){
      if( sqlite3StrICmp(pA->u.zToken,pB->u.zToken)!=0 ) return 2;
    }else if( strcmp(pA->u.zToken,pB->u.zToken)!=0 ){
      return pA->op==TK_COLLATE ? 1 : 2;
    }
  }
  if( (pA->flags & EP_Distinct)!=(pB->flags & EP_Distinct) ) return 2;

/*
** The sqlite3_strglob() interface.
*/
int sqlite3_strglob(const char *zGlobPattern, const char *zString){
  return patternCompare((u8*)zGlobPattern, (u8*)zString, &globInfo, 0)==0;
}

/*
** The sqlite3_strlike() interface.
*/
int sqlite3_strlike(const char *zPattern, const char *zStr, unsigned int esc){
  return patternCompare((u8*)zPattern, (u8*)zStr, &likeInfoNorm, esc)==0;
}

/*
** Count the number of times that the LIKE operator (or GLOB which is
** just a variation of LIKE) gets called.  This is used for testing
** only.
*/
#ifdef SQLITE_TEST

  sqlite3_value **argv
){
  const unsigned char *zA, *zB;
  u32 escape = 0;
  int nPat;
  sqlite3 *db = sqlite3_context_db_handle(context);

#ifdef SQLITE_LIKE_DOESNT_MATCH_BLOBS
  if( sqlite3_value_type(argv[0])==SQLITE_BLOB
   || sqlite3_value_type(argv[1])==SQLITE_BLOB
  ){
#ifdef SQLITE_TEST
    sqlite3_like_count++;
#endif
    sqlite3_result_int(context, 0);
    return;
  }
#endif
  zB = sqlite3_value_text(argv[0]);
  zA = sqlite3_value_text(argv[1]);

  /* Limit the length of the LIKE or GLOB pattern to avoid problems
  ** of deep recursion and N*N behavior in patternCompare().
  */
  nPat = sqlite3_value_bytes(argv[0]);

    pPager = sqlite3BtreePager(pBtree);
    assert( pPager!=0 );
    fd = sqlite3PagerFile(pPager);
    assert( fd!=0 );
    if( op==SQLITE_FCNTL_FILE_POINTER ){
      *(sqlite3_file**)pArg = fd;
      rc = SQLITE_OK;
    }else if( op==SQLITE_FCNTL_VFS_POINTER ){
      *(sqlite3_vfs**)pArg = sqlite3PagerVfs(pPager);
      rc = SQLITE_OK;
    }else if( fd->pMethods ){
      rc = sqlite3OsFileControl(fd, op, pArg);
    }else{
      rc = SQLITE_NOTFOUND;
    }
    sqlite3BtreeLeave(pBtree);
  }

  ** power of two that we can represent using 32-bit signed integers.
  */
  if( nByte > 0x40000000 ){
    return 0;
  }

  /* Round nByte up to the next valid power of two */
  for(iFullSz=mem5.szAtom,iLogsize=0; iFullSz<nByte; iFullSz*=2,iLogsize++){}

  /* Make sure mem5.aiFreelist[iLogsize] contains at least one free
  ** block.  If not, then split a block of the next larger power of
  ** two in order to create a new free block of size iLogsize.
  */
  for(iBin=iLogsize; iBin<=LOGMAX && mem5.aiFreelist[iBin]<0; iBin++){}
  if( iBin>LOGMAX ){

#if SQLITE_MUTEX_NREF
  volatile int nRef;         /* Number of entrances */
  volatile pthread_t owner;  /* Thread that is within this mutex */
  int trace;                 /* True to trace changes */
#endif
};
#if SQLITE_MUTEX_NREF
#define SQLITE3_MUTEX_INITIALIZER {PTHREAD_MUTEX_INITIALIZER,0,0,(pthread_t)0,0}
#else
#define SQLITE3_MUTEX_INITIALIZER { PTHREAD_MUTEX_INITIALIZER }
#endif

/*
** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routine are
** intended for use only inside assert() statements.  On some platforms,

#else
# define UNIXFILE_DIRSYNC    0x00
#endif
#define UNIXFILE_PSOW        0x10     /* SQLITE_IOCAP_POWERSAFE_OVERWRITE */
#define UNIXFILE_DELETE      0x20     /* Delete on close */
#define UNIXFILE_URI         0x40     /* Filename might have query parameters */
#define UNIXFILE_NOLOCK      0x80     /* Do no file locking */



/*
** Include code that is common to all os_*.c files
*/
#include "os_common.h"

/*

** The safest way to deal with the problem is to always use this wrapper
** which always has the same well-defined interface.
*/
static int posixOpen(const char *zFile, int flags, int mode){
  return open(zFile, flags, mode);
}














/* Forward reference */
static int openDirectory(const char*, int*);
static int unixGetpagesize(void);

/*
** Many system calls are accessed through pointer-to-functions so that
** they may be overridden at runtime to facilitate fault injection during

  { "pwrite64",     (sqlite3_syscall_ptr)pwrite64,   0  },
#else
  { "pwrite64",     (sqlite3_syscall_ptr)0,          0  },
#endif
#define osPwrite64  ((ssize_t(*)(int,const void*,size_t,off_t))\
                    aSyscall[13].pCurrent)

  { "fchmod",       (sqlite3_syscall_ptr)fchmod,          0  },
#define osFchmod    ((int(*)(int,mode_t))aSyscall[14].pCurrent)

#if defined(HAVE_POSIX_FALLOCATE) && HAVE_POSIX_FALLOCATE
  { "fallocate",    (sqlite3_syscall_ptr)posix_fallocate,  0 },
#else
  { "fallocate",    (sqlite3_syscall_ptr)0,                0 },
#endif

  { "mkdir",        (sqlite3_syscall_ptr)mkdir,           0 },
#define osMkdir     ((int(*)(const char*,mode_t))aSyscall[18].pCurrent)

  { "rmdir",        (sqlite3_syscall_ptr)rmdir,           0 },
#define osRmdir     ((int(*)(const char*))aSyscall[19].pCurrent)

  { "fchown",       (sqlite3_syscall_ptr)fchown,          0 },
#define osFchown    ((int(*)(int,uid_t,gid_t))aSyscall[20].pCurrent)

  { "geteuid",      (sqlite3_syscall_ptr)geteuid,         0 },
#define osGeteuid   ((uid_t(*)(void))aSyscall[21].pCurrent)

#if !defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0
  { "mmap",       (sqlite3_syscall_ptr)mmap,     0 },
#define osMmap ((void*(*)(void*,size_t,int,int,int,off_t))aSyscall[22].pCurrent)

  { "munmap",       (sqlite3_syscall_ptr)munmap,          0 },
#define osMunmap ((void*(*)(void*,size_t))aSyscall[23].pCurrent)

#if HAVE_MREMAP
  { "mremap",       (sqlite3_syscall_ptr)mremap,          0 },
#else
  { "mremap",       (sqlite3_syscall_ptr)0,               0 },
#endif
#define osMremap ((void*(*)(void*,size_t,size_t,int,...))aSyscall[24].pCurrent)

  { "getpagesize",  (sqlite3_syscall_ptr)unixGetpagesize, 0 },
#define osGetpagesize ((int(*)(void))aSyscall[25].pCurrent)

  { "readlink",     (sqlite3_syscall_ptr)readlink,        0 },
#define osReadlink ((ssize_t(*)(const char*,char*,size_t))aSyscall[26].pCurrent)

#endif

}; /* End of the overrideable system calls */


/*
** On some systems, calls to fchown() will trigger a message in a security
** log if they come from non-root processes.  So avoid calling fchown() if
** we are not running as root.
*/
static int robustFchown(int fd, uid_t uid, gid_t gid){
#if OS_VXWORKS
  return 0;
#else
  return osGeteuid() ? 0 : osFchown(fd,uid,gid);
#endif
}

/*
** This is the xSetSystemCall() method of sqlite3_vfs for all of the
** "unix" VFSes.  Return SQLITE_OK opon successfully updating the
** system call pointer, or SQLITE_NOTFOUND if there is no configurable
** system call named zName.
*/
static int unixSetSystemCall(

** and a variety of "please close the file descriptor NOW" errors into 
** SQLITE_IOERR
** 
** Errors during initialization of locks, or file system support for locks,
** should handle ENOLCK, ENOTSUP, EOPNOTSUPP separately.
*/
static int sqliteErrorFromPosixError(int posixError, int sqliteIOErr) {
  assert( (sqliteIOErr == SQLITE_IOERR_LOCK) || 
          (sqliteIOErr == SQLITE_IOERR_UNLOCK) || 
          (sqliteIOErr == SQLITE_IOERR_RDLOCK) ||
          (sqliteIOErr == SQLITE_IOERR_CHECKRESERVEDLOCK) );
  switch (posixError) {












  case EACCES: 



  case EAGAIN:
  case ETIMEDOUT:
  case EBUSY:
  case EINTR:
  case ENOLCK:  
    /* random NFS retry error, unless during file system support 
     * introspection, in which it actually means what it says */
    return SQLITE_BUSY;
    









  case EPERM: 
    return SQLITE_PERM;
    























  default: 
    return sqliteIOErr;
  }
}


/******************************************************************************

/*
** A lists of all unixInodeInfo objects.
*/
static unixInodeInfo *inodeList = 0;

/*
**
** This function - unixLogErrorAtLine(), is only ever called via the macro
** unixLogError().
**
** It is invoked after an error occurs in an OS function and errno has been
** set. It logs a message using sqlite3_log() containing the current value of
** errno and, if possible, the human-readable equivalent from strerror() or
** strerror_r().
**

  /* Get low-level information about the file that we can used to
  ** create a unique name for the file.
  */
  fd = pFile->h;
  rc = osFstat(fd, &statbuf);
  if( rc!=0 ){
    storeLastErrno(pFile, errno);
#if defined(EOVERFLOW) && defined(SQLITE_DISABLE_LFS)
    if( pFile->lastErrno==EOVERFLOW ) return SQLITE_NOLFS;
#endif
    return SQLITE_IOERR;
  }

#ifdef __APPLE__
  /* On OS X on an msdos filesystem, the inode number is reported

** (3) The file has not been renamed or unlinked
**
** Issue sqlite3_log(SQLITE_WARNING,...) messages if anything is not right.
*/
static void verifyDbFile(unixFile *pFile){
  struct stat buf;
  int rc;





  rc = osFstat(pFile->h, &buf);
  if( rc!=0 ){
    sqlite3_log(SQLITE_WARNING, "cannot fstat db file %s", pFile->zPath);

    return;
  }
  if( buf.st_nlink==0 && (pFile->ctrlFlags & UNIXFILE_DELETE)==0 ){
    sqlite3_log(SQLITE_WARNING, "file unlinked while open: %s", pFile->zPath);

    return;
  }
  if( buf.st_nlink>1 ){
    sqlite3_log(SQLITE_WARNING, "multiple links to file: %s", pFile->zPath);

    return;
  }
  if( fileHasMoved(pFile) ){
    sqlite3_log(SQLITE_WARNING, "file renamed while open: %s", pFile->zPath);

    return;
  }
}


/*
** This routine checks if there is a RESERVED lock held on the specified
** file by this or any other process. If such a lock is held, set *pResOut
** to a non-zero value otherwise *pResOut is set to zero.  The return value
** is set to SQLITE_OK unless an I/O error occurs during lock checking.
*/
static int unixCheckReservedLock(sqlite3_file *id, int *pResOut){
  int rc = SQLITE_OK;
  int reserved = 0;
  unixFile *pFile = (unixFile*)id;

  SimulateIOError( return SQLITE_IOERR_CHECKRESERVEDLOCK; );

  assert( pFile );
  assert( pFile->eFileLock<=SHARED_LOCK );
  unixEnterMutex(); /* Because pFile->pInode is shared across threads */

  /* Check if a thread in this process holds such a lock */
  if( pFile->pInode->eFileLock>SHARED_LOCK ){
    reserved = 1;
  }

** to fcntl() fails. In this case, errno is set appropriately (by fcntl()).
*/
static int unixFileLock(unixFile *pFile, struct flock *pLock){
  int rc;
  unixInodeInfo *pInode = pFile->pInode;
  assert( unixMutexHeld() );
  assert( pInode!=0 );

  if( (pFile->ctrlFlags & (UNIXFILE_EXCL|UNIXFILE_RDONLY))==UNIXFILE_EXCL ){

    if( pInode->bProcessLock==0 ){
      struct flock lock;
      assert( pInode->nLock==0 );
      lock.l_whence = SEEK_SET;
      lock.l_start = SHARED_FIRST;
      lock.l_len = SHARED_SIZE;
      lock.l_type = F_WRLCK;

        lock.l_type = F_UNLCK;
        lock.l_whence = SEEK_SET;
        lock.l_start = SHARED_FIRST;
        lock.l_len = divSize;
        if( unixFileLock(pFile, &lock)==(-1) ){
          tErrno = errno;
          rc = SQLITE_IOERR_UNLOCK;

          storeLastErrno(pFile, tErrno);

          goto end_unlock;
        }
        lock.l_type = F_RDLCK;
        lock.l_whence = SEEK_SET;
        lock.l_start = SHARED_FIRST;
        lock.l_len = divSize;
        if( unixFileLock(pFile, &lock)==(-1) ){

        lock.l_type = F_UNLCK;
        lock.l_whence = SEEK_SET;
        lock.l_start = SHARED_FIRST+divSize;
        lock.l_len = SHARED_SIZE-divSize;
        if( unixFileLock(pFile, &lock)==(-1) ){
          tErrno = errno;
          rc = SQLITE_IOERR_UNLOCK;

          storeLastErrno(pFile, tErrno);

          goto end_unlock;
        }
      }else
#endif /* defined(__APPLE__) && SQLITE_ENABLE_LOCKING_STYLE */
      {
        lock.l_type = F_RDLCK;
        lock.l_whence = SEEK_SET;

  int rc = SQLITE_OK;
  int reserved = 0;
  unixFile *pFile = (unixFile*)id;

  SimulateIOError( return SQLITE_IOERR_CHECKRESERVEDLOCK; );
  
  assert( pFile );









  reserved = osAccess((const char*)pFile->lockingContext, 0)==0;

  OSTRACE(("TEST WR-LOCK %d %d %d (dotlock)\n", pFile->h, rc, reserved));
  *pResOut = reserved;
  return rc;
}

/*
** Lock the file with the lock specified by parameter eFileLock - one

  if( rc<0 ){
    /* failed to open/create the lock directory */
    int tErrno = errno;
    if( EEXIST == tErrno ){
      rc = SQLITE_BUSY;
    } else {
      rc = sqliteErrorFromPosixError(tErrno, SQLITE_IOERR_LOCK);
      if( rc!=SQLITE_BUSY ){
        storeLastErrno(pFile, tErrno);
      }
    }
    return rc;
  } 
  
  /* got it, set the type and return ok */

    pFile->eFileLock = SHARED_LOCK;
    return SQLITE_OK;
  }
  
  /* To fully unlock the database, delete the lock file */
  assert( eFileLock==NO_LOCK );
  rc = osRmdir(zLockFile);

  if( rc<0 ){
    int tErrno = errno;

    if( tErrno==ENOENT ){
      rc = SQLITE_OK;
    }else{
      rc = SQLITE_IOERR_UNLOCK;
      storeLastErrno(pFile, tErrno);
    }
    return rc; 
  }
  pFile->eFileLock = NO_LOCK;
  return SQLITE_OK;
}

/*
** Close a file.  Make sure the lock has been released before closing.
*/
static int dotlockClose(sqlite3_file *id) {


  unixFile *pFile = (unixFile*)id;
  assert( id!=0 );
  dotlockUnlock(id, NO_LOCK);
  sqlite3_free(pFile->lockingContext);
  return closeUnixFile(id);


}
/****************** End of the dot-file lock implementation *******************
******************************************************************************/

/******************************************************************************
************************** Begin flock Locking ********************************
**

    if( !lrc ){
      /* got the lock, unlock it */
      lrc = robust_flock(pFile->h, LOCK_UN);
      if ( lrc ) {
        int tErrno = errno;
        /* unlock failed with an error */
        lrc = SQLITE_IOERR_UNLOCK; 

        storeLastErrno(pFile, tErrno);
        rc = lrc;

      }
    } else {
      int tErrno = errno;
      reserved = 1;
      /* someone else might have it reserved */
      lrc = sqliteErrorFromPosixError(tErrno, SQLITE_IOERR_LOCK); 
      if( IS_LOCK_ERROR(lrc) ){

  }
}

/*
** Close a file.
*/
static int flockClose(sqlite3_file *id) {

  assert( id!=0 );
  flockUnlock(id, NO_LOCK);
  return closeUnixFile(id);


}

#endif /* SQLITE_ENABLE_LOCKING_STYLE && !OS_VXWORK */

/******************* End of the flock lock implementation *********************
******************************************************************************/

}

/*
** Close a file & cleanup AFP specific locking context 
*/
static int afpClose(sqlite3_file *id) {
  int rc = SQLITE_OK;

  unixFile *pFile = (unixFile*)id;
  assert( id!=0 );
  afpUnlock(id, NO_LOCK);
  unixEnterMutex();
  if( pFile->pInode && pFile->pInode->nLock ){
    /* If there are outstanding locks, do not actually close the file just
    ** yet because that would clear those locks.  Instead, add the file
    ** descriptor to pInode->aPending.  It will be automatically closed when
    ** the last lock is cleared.
    */
    setPendingFd(pFile);
  }
  releaseInodeInfo(pFile);
  sqlite3_free(pFile->lockingContext);
  rc = closeUnixFile(id);
  unixLeaveMutex();

  return rc;
}

#endif /* defined(__APPLE__) && SQLITE_ENABLE_LOCKING_STYLE */
/*
** The code above is the AFP lock implementation.  The code is specific
** to MacOSX and does not work on other unix platforms.  No alternative

    got = osPread(id->h, pBuf, cnt, offset);
    SimulateIOError( got = -1 );
#elif defined(USE_PREAD64)
    got = osPread64(id->h, pBuf, cnt, offset);
    SimulateIOError( got = -1 );
#else
    newOffset = lseek(id->h, offset, SEEK_SET);
    SimulateIOError( newOffset = -1 );
    if( newOffset<0 ){

      storeLastErrno((unixFile*)id, errno);



      return -1;
    }
    got = osRead(id->h, pBuf, cnt);
#endif
    if( got==cnt ) break;
    if( got<0 ){
      if( errno==EINTR ){ got = 1; continue; }

  int nBuf,                       /* Size of buffer pBuf in bytes */
  int *piErrno                    /* OUT: Error number if error occurs */
){
  int rc = 0;                     /* Value returned by system call */

  assert( nBuf==(nBuf&0x1ffff) );
  assert( fd>2 );
  assert( piErrno!=0 );
  nBuf &= 0x1ffff;
  TIMER_START;

#if defined(USE_PREAD)
  do{ rc = (int)osPwrite(fd, pBuf, nBuf, iOff); }while( rc<0 && errno==EINTR );
#elif defined(USE_PREAD64)
  do{ rc = (int)osPwrite64(fd, pBuf, nBuf, iOff);}while( rc<0 && errno==EINTR);
#else
  do{
    i64 iSeek = lseek(fd, iOff, SEEK_SET);
    SimulateIOError( iSeek = -1 );

    if( iSeek<0 ){

      rc = -1;
      break;
    }
    rc = osWrite(fd, pBuf, nBuf);
  }while( rc<0 && errno==EINTR );
#endif

  TIMER_END;
  OSTRACE(("WRITE   %-3d %5d %7lld %llu\n", fd, rc, iOff, TIMER_ELAPSED));

  if( rc<0 ) *piErrno = errno;
  return rc;
}


/*
** Seek to the offset in id->offset then read cnt bytes into pBuf.
** Return the number of bytes actually read.  Update the offset.

  */
#ifdef SQLITE_TEST
  if( fullSync ) sqlite3_fullsync_count++;
  sqlite3_sync_count++;
#endif

  /* If we compiled with the SQLITE_NO_SYNC flag, then syncing is a
  ** no-op.  But go ahead and call fstat() to validate the file
  ** descriptor as we need a method to provoke a failure during
  ** coverate testing.
  */
#ifdef SQLITE_NO_SYNC
  {
    struct stat buf;
    rc = osFstat(fd, &buf);
  }
#elif HAVE_FULLFSYNC
  if( fullSync ){
    rc = osFcntl(fd, F_FULLFSYNC, 0);
  }else{
    rc = 1;
  }
  /* If the FULLFSYNC failed, fall back to attempting an fsync().

static int openDirectory(const char *zFilename, int *pFd){
  int ii;
  int fd = -1;
  char zDirname[MAX_PATHNAME+1];

  sqlite3_snprintf(MAX_PATHNAME, zDirname, "%s", zFilename);
  for(ii=(int)strlen(zDirname); ii>1 && zDirname[ii]!='/'; ii--);
  if( ii>1 ){
    zDirname[ii] = '\0';
    fd = robust_open(zDirname, O_RDONLY|O_BINARY, 0);
    if( fd>=0 ){
      OSTRACE(("OPENDIR %-3d %s\n", fd, zDirname));
    }
  }
  *pFd = fd;
  if( fd>=0 ) return SQLITE_OK;
  return unixLogError(SQLITE_CANTOPEN_BKPT, "openDirectory", zDirname);
}

/*
** Make sure all writes to a particular file are committed to disk.
**
** If dataOnly==0 then both the file itself and its metadata (file
** size, access time, etc) are synced.  If dataOnly!=0 then only the

  ** are unable to fsync a directory, so ignore errors on the fsync.
  */
  if( pFile->ctrlFlags & UNIXFILE_DIRSYNC ){
    int dirfd;
    OSTRACE(("DIRSYNC %s (have_fullfsync=%d fullsync=%d)\n", pFile->zPath,
            HAVE_FULLFSYNC, isFullsync));
    rc = osOpenDirectory(pFile->zPath, &dirfd);
    if( rc==SQLITE_OK ){
      full_fsync(dirfd, 0, 0);
      robust_close(pFile, dirfd, __LINE__);
    }else{
      assert( rc==SQLITE_CANTOPEN );
      rc = SQLITE_OK;
    }
    pFile->ctrlFlags &= ~UNIXFILE_DIRSYNC;
  }
  return rc;
}

      ** This is a similar technique to that used by glibc on systems
      ** that do not have a real fallocate() call.
      */
      int nBlk = buf.st_blksize;  /* File-system block size */
      int nWrite = 0;             /* Number of bytes written by seekAndWrite */
      i64 iWrite;                 /* Next offset to write to */

      iWrite = (buf.st_size/nBlk)*nBlk + nBlk - 1;
      assert( iWrite>=buf.st_size );

      assert( ((iWrite+1)%nBlk)==0 );
      for(/*no-op*/; iWrite<nSize+nBlk-1; iWrite+=nBlk ){
        if( iWrite>=nSize ) iWrite = nSize - 1;
        nWrite = seekAndWrite(pFile, iWrite, "", 1);
        if( nWrite!=1 ) return SQLITE_IOERR_WRITE;
      }




#endif
    }
  }

#if SQLITE_MAX_MMAP_SIZE>0
  if( pFile->mmapSizeMax>0 && nByte>pFile->mmapSize ){
    int rc;

/*
** Information and control of an open file handle.
*/
static int unixFileControl(sqlite3_file *id, int op, void *pArg){
  unixFile *pFile = (unixFile*)id;
  switch( op ){




    case SQLITE_FCNTL_LOCKSTATE: {
      *(int*)pArg = pFile->eFileLock;
      return SQLITE_OK;
    }
    case SQLITE_FCNTL_LAST_ERRNO: {
      *(int*)pArg = pFile->lastErrno;
      return SQLITE_OK;

  pShmNode = pFile->pInode->pShmNode;
  assert( sqlite3_mutex_held(pShmNode->mutex) || pShmNode->nRef==0 );

  /* Shared locks never span more than one byte */
  assert( n==1 || lockType!=F_RDLCK );

  /* Locks are within range */
  assert( n>=1 && n<=SQLITE_SHM_NLOCK );

  if( pShmNode->h>=0 ){

    /* Initialize the locking parameters */
    memset(&f, 0, sizeof(f));
    f.l_type = lockType;
    f.l_whence = SEEK_SET;
    f.l_start = ofst;
    f.l_len = n;


    rc = osFcntl(pShmNode->h, F_SETLK, &f);
    rc = (rc!=(-1)) ? SQLITE_OK : SQLITE_BUSY;

  }

  /* Update the global lock state and do debug tracing */
#ifdef SQLITE_DEBUG
  { u16 mask;
  OSTRACE(("SHM-LOCK "));
  mask = ofst>31 ? 0xffff : (1<<(ofst+n)) - (1<<ofst);

**
** This is not a VFS shared-memory method; it is a utility function called
** by VFS shared-memory methods.
*/
static void unixShmPurge(unixFile *pFd){
  unixShmNode *p = pFd->pInode->pShmNode;
  assert( unixMutexHeld() );
  if( p && ALWAYS(p->nRef==0) ){
    int nShmPerMap = unixShmRegionPerMap();
    int i;
    assert( p->pInode==pFd->pInode );
    sqlite3_mutex_free(p->mutex);
    for(i=0; i<p->nRegion; i+=nShmPerMap){
      if( p->h>=0 ){
        osMunmap(p->apRegion[i], p->szRegion);

    const char *zBasePath = pDbFd->zPath;
#endif

    /* Call fstat() to figure out the permissions on the database file. If
    ** a new *-shm file is created, an attempt will be made to create it
    ** with the same permissions.
    */
    if( osFstat(pDbFd->h, &sStat) ){
      rc = SQLITE_IOERR_FSTAT;
      goto shm_open_err;
    }

#ifdef SQLITE_SHM_DIRECTORY
    nShmFilename = sizeof(SQLITE_SHM_DIRECTORY) + 31;
#else

        goto shm_open_err;
      }

      /* If this process is running as root, make sure that the SHM file
      ** is owned by the same user that owns the original database.  Otherwise,
      ** the original owner will not be able to connect.
      */
      robustFchown(pShmNode->h, sStat.st_uid, sStat.st_gid);
  
      /* Check to see if another process is holding the dead-man switch.
      ** If not, truncate the file to zero length. 
      */
      rc = SQLITE_OK;
      if( unixShmSystemLock(pDbFd, F_WRLCK, UNIX_SHM_DMS, 1)==SQLITE_OK ){
        if( robust_ftruncate(pShmNode->h, 0) ){

        else{
          static const int pgsz = 4096;
          int iPg;

          /* Write to the last byte of each newly allocated or extended page */
          assert( (nByte % pgsz)==0 );
          for(iPg=(sStat.st_size/pgsz); iPg<(nByte/pgsz); iPg++){
            int x = 0;
            if( seekAndWriteFd(pShmNode->h, iPg*pgsz + pgsz-1, "", 1, &x)!=1 ){
              const char *zFile = pShmNode->zFilename;
              rc = unixLogError(SQLITE_IOERR_SHMSIZE, "write", zFile);
              goto shmpage_out;
            }
          }
        }
      }

** created mapping is either the requested size or the value configured 
** using SQLITE_FCNTL_MMAP_LIMIT, whichever is smaller.
**
** SQLITE_OK is returned if no error occurs (even if the mapping is not
** recreated as a result of outstanding references) or an SQLite error
** code otherwise.
*/
static int unixMapfile(unixFile *pFd, i64 nMap){



  assert( nMap>=0 || pFd->nFetchOut==0 );
  assert( nMap>0 || (pFd->mmapSize==0 && pFd->pMapRegion==0) );
  if( pFd->nFetchOut>0 ) return SQLITE_OK;

  if( nMap<0 ){
    struct stat statbuf;          /* Low-level file information */
    if( osFstat(pFd->h, &statbuf) ){

      return SQLITE_IOERR_FSTAT;
    }
    nMap = statbuf.st_size;
  }
  if( nMap>pFd->mmapSizeMax ){
    nMap = pFd->mmapSizeMax;
  }

  assert( nMap>0 || (pFd->mmapSize==0 && pFd->pMapRegion==0) );
  if( nMap!=pFd->mmapSize ){

    unixRemapfile(pFd, nMap);



  }

  return SQLITE_OK;
}
#endif /* SQLITE_MAX_MMAP_SIZE>0 */

/*

** Return the name of a directory in which to put temporary files.
** If no suitable temporary file directory can be found, return NULL.
*/
static const char *unixTempFileDir(void){
  static const char *azDirs[] = {
     0,
     0,

     "/var/tmp",
     "/usr/tmp",
     "/tmp",

     "."
  };
  unsigned int i;
  struct stat buf;
  const char *zDir = sqlite3_temp_directory;

  if( !azDirs[0] ) azDirs[0] = getenv("SQLITE_TMPDIR");
  if( !azDirs[1] ) azDirs[1] = getenv("TMPDIR");

  for(i=0; i<sizeof(azDirs)/sizeof(azDirs[0]); zDir=azDirs[i++]){
    if( zDir==0 ) continue;
    if( osStat(zDir, &buf) ) continue;
    if( !S_ISDIR(buf.st_mode) ) continue;
    if( osAccess(zDir, 07) ) continue;
    break;
  }
  return zDir;
}

/*
** Create a temporary file name in zBuf.  zBuf must be allocated
** by the calling process and must be big enough to hold at least
** pVfs->mxPathname bytes.
*/
static int unixGetTempname(int nBuf, char *zBuf){





  const char *zDir;
  int iLimit = 0;

  /* It's odd to simulate an io-error here, but really this is just
  ** using the io-error infrastructure to test that SQLite handles this
  ** function failing. 
  */
  SimulateIOError( return SQLITE_IOERR );

  zDir = unixTempFileDir();









  do{


    u64 r;
    sqlite3_randomness(sizeof(r), &r);



    assert( nBuf>2 );
    zBuf[nBuf-2] = 0;
    sqlite3_snprintf(nBuf, zBuf, "%s/"SQLITE_TEMP_FILE_PREFIX"%llx%c",
                     zDir, r, 0);
    if( zBuf[nBuf-2]!=0 || (iLimit++)>10 ) return SQLITE_ERROR;
  }while( osAccess(zBuf,0)==0 );
  return SQLITE_OK;
}

#if SQLITE_ENABLE_LOCKING_STYLE && defined(__APPLE__)
/*
** Routine to transform a unixFile into a proxy-locking unixFile.

    ** URIs with parameters.  Hence, they can always be passed into
    ** sqlite3_uri_parameter(). */
    assert( (flags & SQLITE_OPEN_URI) || zName[strlen(zName)+1]==0 );

  }else if( !zName ){
    /* If zName is NULL, the upper layer is requesting a temp file. */
    assert(isDelete && !syncDir);
    rc = unixGetTempname(pVfs->mxPathname, zTmpname);
    if( rc!=SQLITE_OK ){
      return rc;
    }
    zName = zTmpname;

    /* Generated temporary filenames are always double-zero terminated
    ** for use by sqlite3_uri_parameter(). */

    if( rc!=SQLITE_OK ){
      assert( !p->pUnused );
      assert( eType==SQLITE_OPEN_WAL || eType==SQLITE_OPEN_MAIN_JOURNAL );
      return rc;
    }
    fd = robust_open(zName, openFlags, openMode);
    OSTRACE(("OPENX   %-3d %s 0%o\n", fd, zName, openFlags));
    assert( !isExclusive || (openFlags & O_CREAT)!=0 );
    if( fd<0 && errno!=EISDIR && isReadWrite ){
      /* Failed to open the file for read/write access. Try read-only. */
      flags &= ~(SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE);
      openFlags &= ~(O_RDWR|O_CREAT);
      flags |= SQLITE_OPEN_READONLY;
      openFlags |= O_RDONLY;
      isReadonly = 1;
      fd = robust_open(zName, openFlags, openMode);
    }
    if( fd<0 ){
      rc = unixLogError(SQLITE_CANTOPEN_BKPT, "open", zName);
      goto open_finished;
    }

    /* If this process is running as root and if creating a new rollback
    ** journal or WAL file, set the ownership of the journal or WAL to be
    ** the same as the original database.
    */
    if( flags & (SQLITE_OPEN_WAL|SQLITE_OPEN_MAIN_JOURNAL) ){
      robustFchown(fd, uid, gid);
    }
  }
  assert( fd>=0 );
  if( pOutFlags ){
    *pOutFlags = flags;
  }

#else
      if( fsync(fd) )
#endif
      {
        rc = unixLogError(SQLITE_IOERR_DIR_FSYNC, "fsync", zPath);
      }
      robust_close(0, fd, __LINE__);
    }else{
      assert( rc==SQLITE_CANTOPEN );
      rc = SQLITE_OK;
    }
  }
#endif
  return rc;
}

*/
static int unixAccess(
  sqlite3_vfs *NotUsed,   /* The VFS containing this xAccess method */
  const char *zPath,      /* Path of the file to examine */
  int flags,              /* What do we want to learn about the zPath file? */
  int *pResOut            /* Write result boolean here */
){

  UNUSED_PARAMETER(NotUsed);
  SimulateIOError( return SQLITE_IOERR_ACCESS; );
  assert( pResOut!=0 );











  /* The spec says there are three possible values for flags.  But only
  ** two of them are actually used */
  assert( flags==SQLITE_ACCESS_EXISTS || flags==SQLITE_ACCESS_READWRITE );


  if( flags==SQLITE_ACCESS_EXISTS ){
    struct stat buf;
    *pResOut = (0==osStat(zPath, &buf) && buf.st_size>0);
  }else{
    *pResOut = osAccess(zPath, W_OK|R_OK)==0;

  }
  return SQLITE_OK;
}


/*
** Turn a relative pathname into a full pathname. The relative path

  ** zPath is copied directly into zOut. Either way, nByte is left set to
  ** the size of the string copied into zOut[] in bytes.  */
  nByte = osReadlink(zPath, zOut, nOut-1);
  if( nByte<0 ){
    if( errno!=EINVAL && errno!=ENOENT ){
      return unixLogError(SQLITE_CANTOPEN_BKPT, "readlink", zPath);
    }

    sqlite3_snprintf(nOut, zOut, "%s", zPath);
    nByte = sqlite3Strlen30(zOut);
  }else{
    zOut[nByte] = '\0';
  }

  /* If buffer zOut[] now contains an absolute path there is nothing more
  ** to do. If it contains a relative path, do the following:

  **     follows the '/'.
  **
  ** This code is written so that if the combination of the CWD and relative
  ** path are larger than the allocated size of zOut[] the CWD is silently
  ** truncated to make it fit. This is Ok, as SQLite refuses to open any
  ** file for which this function returns a full path larger than (nOut-8)
  ** bytes in size.  */
  testcase( nByte==nOut-5 );
  testcase( nByte==nOut-4 );
  if( zOut[0]!='/' && nByte<nOut-4 ){
    int nCwd;
    int nRem = nOut-nByte-1;
    memmove(&zOut[nRem], zOut, nByte+1);
    zOut[nRem-1] = '\0';
    if( osGetcwd(zOut, nRem-1)==0 ){
      return unixLogError(SQLITE_CANTOPEN_BKPT, "getcwd", zPath);
    }

  *piNow = ((sqlite3_int64)t)*1000 + unixEpoch;
#elif OS_VXWORKS
  struct timespec sNow;
  clock_gettime(CLOCK_REALTIME, &sNow);
  *piNow = unixEpoch + 1000*(sqlite3_int64)sNow.tv_sec + sNow.tv_nsec/1000000;
#else
  struct timeval sNow;
  (void)gettimeofday(&sNow, 0);  /* Cannot fail given valid arguments */
  *piNow = unixEpoch + 1000*(sqlite3_int64)sNow.tv_sec + sNow.tv_usec/1000;



#endif

#ifdef SQLITE_TEST
  if( sqlite3_current_time ){
    *piNow = 1000*(sqlite3_int64)sqlite3_current_time + unixEpoch;
  }
#endif
  UNUSED_PARAMETER(NotUsed);
  return rc;
}

#if 0 /* Not used */
/*
** Find the current time (in Universal Coordinated Time).  Write the
** current time and date as a Julian Day number into *prNow and
** return 0.  Return 1 if the time and date cannot be found.
*/
static int unixCurrentTime(sqlite3_vfs *NotUsed, double *prNow){
  sqlite3_int64 i = 0;
  int rc;
  UNUSED_PARAMETER(NotUsed);
  rc = unixCurrentTimeInt64(0, &i);
  *prNow = i/86400000.0;
  return rc;
}
#else
# define unixCurrentTime 0
#endif

#if 0  /* Not used */
/*
** We added the xGetLastError() method with the intention of providing
** better low-level error messages when operating-system problems come up
** during SQLite operation.  But so far, none of that has been implemented
** in the core.  So this routine is never called.  For now, it is merely
** a place-holder.
*/
static int unixGetLastError(sqlite3_vfs *NotUsed, int NotUsed2, char *NotUsed3){
  UNUSED_PARAMETER(NotUsed);
  UNUSED_PARAMETER(NotUsed2);
  UNUSED_PARAMETER(NotUsed3);
  return 0;
}
#else
# define unixGetLastError 0
#endif


/*
************************ End of sqlite3_vfs methods ***************************
******************************************************************************/

/******************************************************************************

          }
        }
      }
      start=i+1;
    }
    buf[i] = lockPath[i];
  }
  OSTRACE(("CREATELOCKPATH  proxy lock path=%s pid=%d\n",lockPath,osGetpid(0)));
  return 0;
}

/*
** Create a new VFS file descriptor (stored in memory obtained from
** sqlite3_malloc) and open the file named "path" in the file descriptor.
**

  return rc;
}

/*
** Close a file that uses proxy locks.
*/
static int proxyClose(sqlite3_file *id) {
  if( ALWAYS(id) ){
    unixFile *pFile = (unixFile*)id;
    proxyLockingContext *pCtx = (proxyLockingContext *)pFile->lockingContext;
    unixFile *lockProxy = pCtx->lockProxy;
    unixFile *conchFile = pCtx->conchFile;
    int rc = SQLITE_OK;
    
    if( lockProxy ){

    UNIXVFS("unix-proxy",    proxyIoFinder ),
#endif
  };
  unsigned int i;          /* Loop counter */

  /* Double-check that the aSyscall[] array has been constructed
  ** correctly.  See ticket [bb3a86e890c8e96ab] */
  assert( ArraySize(aSyscall)==27 );

  /* Register all VFSes defined in the aVfs[] array */
  for(i=0; i<(sizeof(aVfs)/sizeof(sqlite3_vfs)); i++){
    sqlite3_vfs_register(&aVfs[i], i==0);
  }
  return SQLITE_OK; 
}

  OSTRACE(("TEST-WR-LOCK file=%p, pResOut=%p\n", pFile->h, pResOut));

  assert( id!=0 );
  if( pFile->locktype>=RESERVED_LOCK ){
    res = 1;
    OSTRACE(("TEST-WR-LOCK file=%p, result=%d (local)\n", pFile->h, res));
  }else{
    res = winLockFile(&pFile->h, SQLITE_LOCKFILEEX_FLAGS,RESERVED_BYTE,0,1,0);
    if( res ){
      winUnlockFile(&pFile->h, RESERVED_BYTE, 0, 1, 0);
    }
    res = !res;
    OSTRACE(("TEST-WR-LOCK file=%p, result=%d (remote)\n", pFile->h, res));
  }
  *pResOut = res;

const char *sqlite3PagerFilename(Pager *pPager, int nullIfMemDb){
  return (nullIfMemDb && pPager->memDb) ? "" : pPager->zFilename;
}

/*
** Return the VFS structure for the pager.
*/
sqlite3_vfs *sqlite3PagerVfs(Pager *pPager){
  return pPager->pVfs;
}

/*
** Return the file handle for the database file associated
** with the pager.  This might return NULL if the file has
** not yet been opened.

u8 sqlite3PagerIsreadonly(Pager*);
u32 sqlite3PagerDataVersion(Pager*);
#ifdef SQLITE_DEBUG
  int sqlite3PagerRefcount(Pager*);
#endif
int sqlite3PagerMemUsed(Pager*);
const char *sqlite3PagerFilename(Pager*, int);
sqlite3_vfs *sqlite3PagerVfs(Pager*);
sqlite3_file *sqlite3PagerFile(Pager*);
const char *sqlite3PagerJournalname(Pager*);
int sqlite3PagerNosync(Pager*);
void *sqlite3PagerTempSpace(Pager*);
int sqlite3PagerIsMemdb(Pager*);
void sqlite3PagerCacheStat(Pager *, int, int, int *);
void sqlite3PagerClearCache(Pager *);

**         SQLITE_CONFIG_PAGECACHE.
**    (3)  PCache-local bulk allocation.
**
** The third case is a chunk of heap memory (defaulting to 100 pages worth)
** that is allocated when the page cache is created.  The size of the local
** bulk allocation can be adjusted using 
**
**     sqlite3_config(SQLITE_CONFIG_PAGECACHE, (void*)0, 0, N).
**
** If N is positive, then N pages worth of memory are allocated using a single
** sqlite3Malloc() call and that memory is used for the first N pages allocated.
** Or if N is negative, then -1024*N bytes of memory are allocated and used
** for as many pages as can be accomodated.
**
** Only one of (2) or (3) can be used.  Once the memory available to (2) or

      while( c>='0' && c<='9' ){
        wx = wx*10 + c - '0';
        c = *++fmt;
      }
      testcase( wx>0x7fffffff );
      width = wx & 0x7fffffff;
    }
    assert( width>=0 );
#ifdef SQLITE_PRINTF_PRECISION_LIMIT
    if( width>SQLITE_PRINTF_PRECISION_LIMIT ){
      width = SQLITE_PRINTF_PRECISION_LIMIT;
    }
#endif

    /* Get the precision */
    if( c=='.' ){
      c = *++fmt;
      if( c=='*' ){
        if( bArgList ){
          precision = (int)getIntArg(pArgList);

        }
        testcase( px>0x7fffffff );
        precision = px & 0x7fffffff;
      }
    }else{
      precision = -1;
    }
    assert( precision>=(-1) );
#ifdef SQLITE_PRINTF_PRECISION_LIMIT
    if( precision>SQLITE_PRINTF_PRECISION_LIMIT ){
      precision = SQLITE_PRINTF_PRECISION_LIMIT;
    }
#endif


    /* Get the conversion type modifier */
    if( c=='l' ){
      flag_long = 1;
      c = *++fmt;
      if( c=='l' ){
        flag_longlong = 1;
        c = *++fmt;

** list rather than a single expression.
*/
int sqlite3ResolveExprListNames( 
  NameContext *pNC,       /* Namespace to resolve expressions in. */
  ExprList *pList         /* The expression list to be analyzed. */
){
  int i;
  if( pList ){
    for(i=0; i<pList->nExpr; i++){
      if( sqlite3ResolveExprNames(pNC, pList->a[i].pExpr) ) return WRC_Abort;
    }
  }
  return WRC_Continue;
}

/*
** Resolve all names in all expressions of a SELECT and in all
** decendents of the SELECT, including compounds off of p->pPrior,

  u8 estWidth = 1;
#ifdef SQLITE_ENABLE_COLUMN_METADATA
  char const *zOrigDb = 0;
  char const *zOrigTab = 0;
  char const *zOrigCol = 0;
#endif

  assert( pExpr!=0 );
  assert( pNC->pSrcList!=0 );
  switch( pExpr->op ){
    case TK_AGG_COLUMN:
    case TK_COLUMN: {
      /* The expression is a column. Locate the table the column is being
      ** extracted from in NameContext.pSrcList. This table may be real
      ** database table or a subquery.
      */

#ifndef SQLITE_OMIT_EXPLAIN
  /* If this is an EXPLAIN, skip this step */
  if( pParse->explain ){
    return;
  }
#endif

  assert( pTabList!=0 );
  if( pParse->colNamesSet || NEVER(v==0) || db->mallocFailed ) return;
  pParse->colNamesSet = 1;
  fullNames = (db->flags & SQLITE_FullColNames)!=0;
  shortNames = (db->flags & SQLITE_ShortColNames)!=0;
  sqlite3VdbeSetNumCols(v, pEList->nExpr);
  for(i=0; i<pEList->nExpr; i++){
    Expr *p;
    p = pEList->a[i].pExpr;
    if( NEVER(p==0) ) continue;
    if( pEList->a[i].zName ){
      char *zName = pEList->a[i].zName;
      sqlite3VdbeSetColName(v, i, COLNAME_NAME, zName, SQLITE_TRANSIENT);
    }else if( p->op==TK_COLUMN || p->op==TK_AGG_COLUMN ){
      Table *pTab;
      char *zCol;
      int iCol = p->iColumn;
      for(j=0; ALWAYS(j<pTabList->nSrc); j++){
        if( pTabList->a[j].iCursor==p->iTable ) break;
      }
      assert( j<pTabList->nSrc );

    nCol = pEList->nExpr;
    aCol = sqlite3DbMallocZero(db, sizeof(aCol[0])*nCol);
    testcase( aCol==0 );
  }else{
    nCol = 0;
    aCol = 0;
  }
  assert( nCol==(i16)nCol );
  *pnCol = nCol;
  *paCol = aCol;

  for(i=0, pCol=aCol; i<nCol && !db->mallocFailed; i++, pCol++){
    /* Get an appropriate name for the column
    */
    p = sqlite3ExprSkipCollate(pEList->a[i].pExpr);

      assert( unionTab==dest.iSDParm || dest.eDest!=priorOp );
      if( dest.eDest!=priorOp ){
        int iCont, iBreak, iStart;
        assert( p->pEList );
        if( dest.eDest==SRT_Output ){
          Select *pFirst = p;
          while( pFirst->pPrior ) pFirst = pFirst->pPrior;
          generateColumnNames(pParse, pFirst->pSrc, pFirst->pEList);
        }
        iBreak = sqlite3VdbeMakeLabel(v);
        iCont = sqlite3VdbeMakeLabel(v);
        computeLimitRegisters(pParse, p, iBreak);
        sqlite3VdbeAddOp2(v, OP_Rewind, unionTab, iBreak); VdbeCoverage(v);
        iStart = sqlite3VdbeCurrentAddr(v);
        selectInnerLoop(pParse, p, p->pEList, unionTab,

      /* Generate code to take the intersection of the two temporary
      ** tables.
      */
      assert( p->pEList );
      if( dest.eDest==SRT_Output ){
        Select *pFirst = p;
        while( pFirst->pPrior ) pFirst = pFirst->pPrior;
        generateColumnNames(pParse, pFirst->pSrc, pFirst->pEList);
      }
      iBreak = sqlite3VdbeMakeLabel(v);
      iCont = sqlite3VdbeMakeLabel(v);
      computeLimitRegisters(pParse, p, iBreak);
      sqlite3VdbeAddOp2(v, OP_Rewind, tab1, iBreak); VdbeCoverage(v);
      r1 = sqlite3GetTempReg(pParse);
      iStart = sqlite3VdbeAddOp2(v, OP_RowKey, tab1, r1);

  sqlite3VdbeResolveLabel(v, labelEnd);

  /* Set the number of output columns
  */
  if( pDest->eDest==SRT_Output ){
    Select *pFirst = pPrior;
    while( pFirst->pPrior ) pFirst = pFirst->pPrior;
    generateColumnNames(pParse, pFirst->pSrc, pFirst->pEList);
  }

  /* Reassembly the compound query so that it will be freed correctly
  ** by the calling function */
  if( p->pPrior ){
    sqlite3SelectDelete(db, p->pPrior);
  }

    }

    /* Transfer the FROM clause terms from the subquery into the
    ** outer query.
    */
    for(i=0; i<nSubSrc; i++){
      sqlite3IdListDelete(db, pSrc->a[i+iFrom].pUsing);
      assert( pSrc->a[i+iFrom].fg.isTabFunc==0 );
      pSrc->a[i+iFrom] = pSubSrc->a[i];
      memset(&pSubSrc->a[i], 0, sizeof(pSubSrc->a[i]));
    }
    pSrc->a[iFrom].fg.jointype = jointype;
  
    /* Now begin substituting subquery result set expressions for 
    ** references to the iParent in the outer query.

  p->selFlags |= SF_Converted;
  assert( pNew->pPrior!=0 );
  pNew->pPrior->pNext = pNew;
  pNew->pLimit = 0;
  pNew->pOffset = 0;
  return WRC_Continue;
}

/*
** Check to see if the FROM clause term pFrom has table-valued function
** arguments.  If it does, leave an error message in pParse and return
** non-zero, since pFrom is not allowed to be a table-valued function.
*/
static int cannotBeFunction(Parse *pParse, struct SrcList_item *pFrom){
  if( pFrom->fg.isTabFunc ){
    sqlite3ErrorMsg(pParse, "'%s' is not a function", pFrom->zName);
    return 1;
  }
  return 0;
}

#ifndef SQLITE_OMIT_CTE
/*
** Argument pWith (which may be NULL) points to a linked list of nested 
** WITH contexts, from inner to outermost. If the table identified by 
** FROM clause element pItem is really a common-table-expression (CTE) 
** then return a pointer to the CTE definition for that table. Otherwise

    ** recursive reference to CTE pCte. Leave an error in pParse and return
    ** early. If pCte->zCteErr is NULL, then this is not a recursive reference.
    ** In this case, proceed.  */
    if( pCte->zCteErr ){
      sqlite3ErrorMsg(pParse, pCte->zCteErr, pCte->zName);
      return SQLITE_ERROR;
    }
    if( cannotBeFunction(pParse, pFrom) ) return SQLITE_ERROR;

    assert( pFrom->pTab==0 );
    pFrom->pTab = pTab = sqlite3DbMallocZero(db, sizeof(Table));
    if( pTab==0 ) return WRC_Abort;
    pTab->nRef = 1;
    pTab->zName = sqlite3DbStrDup(db, pCte->zName);
    pTab->iPKey = -1;

      if( pTab->nRef==0xffff ){
        sqlite3ErrorMsg(pParse, "too many references to \"%s\": max 65535",
           pTab->zName);
        pFrom->pTab = 0;
        return WRC_Abort;
      }
      pTab->nRef++;
      if( !IsVirtual(pTab) && cannotBeFunction(pParse, pFrom) ){
        return WRC_Abort;
      }
#if !defined(SQLITE_OMIT_VIEW) || !defined (SQLITE_OMIT_VIRTUALTABLE)
      if( IsVirtual(pTab) || pTab->pSelect ){
        i16 nCol;
        if( sqlite3ViewGetColumnNames(pParse, pTab) ) return WRC_Abort;
        assert( pFrom->pSelect==0 );




        pFrom->pSelect = sqlite3SelectDup(db, pTab->pSelect, 0);
        sqlite3SelectSetName(pFrom->pSelect, pTab->zName);
        nCol = pTab->nCol;
        pTab->nCol = -1;
        sqlite3WalkSelect(pWalker, pFrom->pSelect);
        pTab->nCol = nCol;
      }

    }
    sqlite3ExprListDelete(db, pEList);
    p->pEList = pNew;
  }
#if SQLITE_MAX_COLUMN
  if( p->pEList && p->pEList->nExpr>db->aLimit[SQLITE_LIMIT_COLUMN] ){
    sqlite3ErrorMsg(pParse, "too many columns in result set");
    return WRC_Abort;
  }
#endif
  return WRC_Continue;
}

/*
** No-op routine for the parse-tree walker.

  ".system CMD ARGS...    Run CMD ARGS... in a system shell\n"
  ".tables ?TABLE?        List names of tables\n"
  "                         If TABLE specified, only list tables matching\n"
  "                         LIKE pattern TABLE.\n"
  ".timeout MS            Try opening locked tables for MS milliseconds\n"
  ".timer on|off          Turn SQL timer on or off\n"
  ".trace FILE|off        Output each SQL statement as it is run\n"
  ".vfsinfo ?AUX?         Information about the top-level VFS\n"
  ".vfsname ?AUX?         Print the name of the VFS stack\n"
  ".width NUM1 NUM2 ...   Set column widths for \"column\" mode\n"
  "                         Negative values right-justify\n"
;

/* Forward reference */
static int process_input(ShellState *p, FILE *in);

  }else
#endif /* SQLITE_USER_AUTHENTICATION */

  if( c=='v' && strncmp(azArg[0], "version", n)==0 ){
    fprintf(p->out, "SQLite %s %s\n" /*extra-version-info*/,
        sqlite3_libversion(), sqlite3_sourceid());
  }else

  if( c=='v' && strncmp(azArg[0], "vfsinfo", n)==0 ){
    const char *zDbName = nArg==2 ? azArg[1] : "main";
    sqlite3_vfs *pVfs;
    if( p->db ){
      sqlite3_file_control(p->db, zDbName, SQLITE_FCNTL_VFS_POINTER, &pVfs);
      if( pVfs ){
        fprintf(p->out, "vfs.zName      = \"%s\"\n", pVfs->zName);
        fprintf(p->out, "vfs.iVersion   = %d\n", pVfs->iVersion);
        fprintf(p->out, "vfs.szOsFile   = %d\n", pVfs->szOsFile);
        fprintf(p->out, "vfs.mxPathname = %d\n", pVfs->mxPathname);
      }
    }
  }else

  if( c=='v' && strncmp(azArg[0], "vfsname", n)==0 ){
    const char *zDbName = nArg==2 ? azArg[1] : "main";
    char *zVfsName = 0;
    if( p->db ){
      sqlite3_file_control(p->db, zDbName, SQLITE_FCNTL_VFSNAME, &zVfsName);
      if( zVfsName ){

** [sqlite3_malloc()] and the result is stored in the char* variable
** that the fourth parameter of [sqlite3_file_control()] points to.
** The caller is responsible for freeing the memory when done.  As with
** all file-control actions, there is no guarantee that this will actually
** do anything.  Callers should initialize the char* variable to a NULL
** pointer in case this file-control is not implemented.  This file-control
** is intended for diagnostic use only.
**
** <li>[[SQLITE_FCNTL_VFS_POINTER]]
** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level
** [VFSes] currently in use.  ^(The argument X in
** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be
** of type "[sqlite3_vfs] **".  This opcodes will set *X
** to a pointer to the top-level VFS.^)
** ^When there are multiple VFS shims in the stack, this opcode finds the
** upper-most shim only.
**
** <li>[[SQLITE_FCNTL_PRAGMA]]
** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 
** file control is sent to the open [sqlite3_file] object corresponding
** to the database file to which the pragma statement refers. ^The argument
** to the [SQLITE_FCNTL_PRAGMA] file control is an array of
** pointers to strings (char**) in which the second element of the array

#define SQLITE_FCNTL_HAS_MOVED              20
#define SQLITE_FCNTL_SYNC                   21
#define SQLITE_FCNTL_COMMIT_PHASETWO        22
#define SQLITE_FCNTL_WIN32_SET_HANDLE       23
#define SQLITE_FCNTL_WAL_BLOCK              24
#define SQLITE_FCNTL_ZIPVFS                 25
#define SQLITE_FCNTL_RBU                    26
#define SQLITE_FCNTL_VFS_POINTER            27

/* 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

** and makes other simplifications to the WHERE clause in an attempt to
** get as many WHERE clause terms into the form shown above as possible.
** ^The aConstraint[] array only reports WHERE clause terms that are
** relevant to the particular virtual table being queried.
**
** ^Information about the ORDER BY clause is stored in aOrderBy[].
** ^Each term of aOrderBy records a column of the ORDER BY clause.
**
** The colUsed field indicates which columns of the virtual table may be
** required by the current scan. Virtual table columns are numbered from
** zero in the order in which they appear within the CREATE TABLE statement
** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62),
** the corresponding bit is set within the colUsed mask if the column may be
** required by SQLite. If the table has at least 64 columns and any column
** to the right of the first 63 is required, then bit 63 of colUsed is also
** set. In other words, column iCol may be required if the expression
** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 
** non-zero.
**
** The [xBestIndex] method must fill aConstraintUsage[] with information
** about what parameters to pass to xFilter.  ^If argvIndex>0 then
** the right-hand side of the corresponding aConstraint[] is evaluated
** and becomes the argvIndex-th entry in argv.  ^(If aConstraintUsage[].omit
** is true, then the constraint is assumed to be fully handled by the
** virtual table and is not checked again by SQLite.)^

  int needToFreeIdxStr;      /* Free idxStr using sqlite3_free() if true */
  int orderByConsumed;       /* True if output is already ordered */
  double estimatedCost;           /* Estimated cost of using this index */
  /* Fields below are only available in SQLite 3.8.2 and later */
  sqlite3_int64 estimatedRows;    /* Estimated number of rows returned */
  /* Fields below are only available in SQLite 3.9.0 and later */
  int idxFlags;              /* Mask of SQLITE_INDEX_SCAN_* flags */
  /* Fields below are only available in SQLite 3.10.0 and later */
  sqlite3_uint64 colUsed;    /* Input: Mask of columns used by statement */
};

/*
** CAPI3REF: Virtual Table Scan Flags
*/
#define SQLITE_INDEX_SCAN_UNIQUE      1     /* Scan visits at most 1 row */

/*
** CAPI3REF: Virtual Table Constraint Operator Codes
**
** These macros defined the allowed values for the
** [sqlite3_index_info].aConstraint[].op field.  Each value represents
** an operator that is part of a constraint term in the wHERE clause of
** a query that uses a [virtual table].
*/
#define SQLITE_INDEX_CONSTRAINT_EQ      2
#define SQLITE_INDEX_CONSTRAINT_GT      4
#define SQLITE_INDEX_CONSTRAINT_LE      8
#define SQLITE_INDEX_CONSTRAINT_LT     16
#define SQLITE_INDEX_CONSTRAINT_GE     32
#define SQLITE_INDEX_CONSTRAINT_MATCH  64
#define SQLITE_INDEX_CONSTRAINT_LIKE   65
#define SQLITE_INDEX_CONSTRAINT_GLOB   66
#define SQLITE_INDEX_CONSTRAINT_REGEXP 67

/*
** CAPI3REF: Register A Virtual Table Implementation
** METHOD: sqlite3
**
** ^These routines are used to register a new [virtual table module] name.
** ^Module names must be registered before

*/
int sqlite3_stricmp(const char *, const char *);
int sqlite3_strnicmp(const char *, const char *, int);

/*
** CAPI3REF: String Globbing
*
** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if
** string X matches the [GLOB] pattern P.
** ^The definition of [GLOB] pattern matching used in
** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the
** SQL dialect understood by SQLite.  ^The [sqlite3_strglob(P,X)] function
** is case sensitive.
**
** Note that this routine returns zero on a match and non-zero if the strings
** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
**
** See also: [sqlite3_strlike()].
*/
int sqlite3_strglob(const char *zGlob, const char *zStr);

/*
** CAPI3REF: String LIKE Matching
*
** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if
** string X matches the [LIKE] pattern P with escape character E.
** ^The definition of [LIKE] pattern matching used in
** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E"
** operator in the SQL dialect understood by SQLite.  ^For "X LIKE P" without
** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0.
** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case
** insensitive - equivalent upper and lower case ASCII characters match
** one another.
**
** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though
** only ASCII characters are case folded.
**
** Note that this routine returns zero on a match and non-zero if the strings
** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
**
** See also: [sqlite3_strglob()].
*/
int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc);

/*
** CAPI3REF: Error Logging Interface
**
** ^The [sqlite3_log()] interface writes a message into the [error log]
** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
** ^If logging is enabled, the zFormat string and subsequent arguments are

  sqlite3_value *(*value_dup)(const sqlite3_value*);
  void (*value_free)(sqlite3_value*);
  int (*result_zeroblob64)(sqlite3_context*,sqlite3_uint64);
  int (*bind_zeroblob64)(sqlite3_stmt*, int, sqlite3_uint64);
  /* Version 3.9.0 and later */
  unsigned int (*value_subtype)(sqlite3_value*);
  void (*result_subtype)(sqlite3_context*,unsigned int);
  /* Version 3.10.0 and later */
  int (*strlike)(const char*,const char*,unsigned int);
};

/*
** The following macros redefine the API routines so that they are
** redirected through the global sqlite3_api structure.
**
** This header file is also used by the loadext.c source file

#define sqlite3_value_dup              sqlite3_api->value_dup
#define sqlite3_value_free             sqlite3_api->value_free
#define sqlite3_result_zeroblob64      sqlite3_api->result_zeroblob64
#define sqlite3_bind_zeroblob64        sqlite3_api->bind_zeroblob64
/* Version 3.9.0 and later */
#define sqlite3_value_subtype          sqlite3_api->value_subtype
#define sqlite3_result_subtype         sqlite3_api->result_subtype
/* Version 3.10.0 and later */
#define sqlite3_strlike                sqlite3_api->strlike
#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;

    }
  }
  *pzStr = zIn;
  if( doFree ){
    sqlite3_free(zAppend);
  }
}

/*
** This function returns a pointer to an sqlite3_malloc()ed buffer 
** containing the select-list (the thing between keywords SELECT and FROM)
** to query the underlying real table with for the scan described by
** argument pIdxInfo.
**
** If the current SQLite version is earlier than 3.10.0, this is just "*"
** (select all columns). Or, for version 3.10.0 and greater, the list of
** columns identified by the pIdxInfo->colUsed mask.
*/
static char *echoSelectList(echo_vtab *pTab, sqlite3_index_info *pIdxInfo){
  char *zRet = 0;
  if( sqlite3_libversion_number()<3010000 ){
    zRet = sqlite3_mprintf(", *");
  }else{
    int i;
    for(i=0; i<pTab->nCol; i++){
      if( pIdxInfo->colUsed & ((sqlite3_uint64)1 << (i>=63 ? 63 : i)) ){
        zRet = sqlite3_mprintf("%z, %s", zRet, pTab->aCol[i]);
      }else{
        zRet = sqlite3_mprintf("%z, NULL", zRet);
      }
      if( !zRet ) break;
    }
  }
  return zRet;
}

/*
** The echo module implements the subset of query constraints and sort
** orders that may take advantage of SQLite indices on the underlying
** real table. For example, if the real table is declared as:
**
**     CREATE TABLE real(a, b, c);

**
** where the <where-clause> and <order-by-clause> are determined
** by the contents of the structure pointed to by the pIdxInfo argument.
*/
static int echoBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
  int ii;
  char *zQuery = 0;
  char *zCol = 0;
  char *zNew;
  int nArg = 0;
  const char *zSep = "WHERE";
  echo_vtab *pVtab = (echo_vtab *)tab;
  sqlite3_stmt *pStmt = 0;
  Tcl_Interp *interp = pVtab->interp;

    nRow = sqlite3_column_int(pStmt, 0);
    rc = sqlite3_finalize(pStmt);
    if( rc!=SQLITE_OK ){
      return rc;
    }
  }

  zCol = echoSelectList(pVtab, pIdxInfo);
  if( !zCol ) return SQLITE_NOMEM;
  zQuery = sqlite3_mprintf("SELECT rowid%z FROM %Q", zCol, pVtab->zTableName);
  if( !zQuery ) return SQLITE_NOMEM;


  for(ii=0; ii<pIdxInfo->nConstraint; ii++){
    const struct sqlite3_index_constraint *pConstraint;
    struct sqlite3_index_constraint_usage *pUsage;
    int iCol;

    pConstraint = &pIdxInfo->aConstraint[ii];
    pUsage = &pIdxInfo->aConstraintUsage[ii];

        case SQLITE_INDEX_CONSTRAINT_GT:
          zOp = ">"; break;
        case SQLITE_INDEX_CONSTRAINT_LE:
          zOp = "<="; break;
        case SQLITE_INDEX_CONSTRAINT_GE:
          zOp = ">="; break;
        case SQLITE_INDEX_CONSTRAINT_MATCH:
          /* Purposely translate the MATCH operator into a LIKE, which
          ** will be used by the next block of code to construct a new
          ** query.  It should also be noted here that the next block
          ** of code requires the first letter of this operator to be
          ** in upper-case to trigger the special MATCH handling (i.e.
          ** wrapping the bound parameter with literal '%'s).
          */
          zOp = "LIKE"; break;
        case SQLITE_INDEX_CONSTRAINT_LIKE:
          zOp = "like"; break;
        case SQLITE_INDEX_CONSTRAINT_GLOB:
          zOp = "glob"; break;
        case SQLITE_INDEX_CONSTRAINT_REGEXP:
          zOp = "regexp"; break;
      }
      if( zOp[0]=='L' ){
        zNew = sqlite3_mprintf(" %s %s LIKE (SELECT '%%'||?||'%%')", 
                               zSep, zCol);
      } else {
        zNew = sqlite3_mprintf(" %s %s %s ?", zSep, zCol, zOp);
      }

#endif

#ifdef SQLITE_ENABLE_JSON1
  Tcl_SetVar2(interp, "sqlite_options", "json1", "1", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "json1", "0", TCL_GLOBAL_ONLY);
#endif

#ifdef SQLITE_LIKE_DOESNT_MATCH_BLOBS
  Tcl_SetVar2(interp, "sqlite_options", "like_match_blobs", "0", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "like_match_blobs", "1", TCL_GLOBAL_ONLY);
#endif

#ifdef SQLITE_OMIT_ATTACH
  Tcl_SetVar2(interp, "sqlite_options", "attach", "0", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "attach", "1", TCL_GLOBAL_ONLY);
#endif

**
**   CREATE TABLE idx(id INTEGER PRIMARY KEY, path TEXT);
**   INSERT INTO idx VALUES(4, '/etc/passwd');
**
** Adding the row to the idx table automatically creates a row in the 
** virtual table with rowid=4, path=/etc/passwd and a text field that 
** contains data read from file /etc/passwd on disk.
**
*************************************************************************
** Virtual table module "fsdir"
**
** This module is designed to be used as a read-only eponymous virtual table.
** Its schema is as follows:
**
**   CREATE TABLE fsdir(dir TEXT, name TEXT);
**
** When queried, a WHERE term of the form "dir = $dir" must be provided. The
** virtual table then appears to have one row for each entry in file-system
** directory $dir. Column dir contains a copy of $dir, and column "name"
** contains the name of the directory entry.
**
** If the specified $dir cannot be opened or is not a directory, it is not
** an error. The virtual table appears to be empty in this case.
**
*************************************************************************
** Virtual table module "fstree"
**
** This module is also a read-only eponymous virtual table with the 
** following schema:
**
**   CREATE TABLE fstree(path TEXT, size INT, data BLOB);
**
** Running a "SELECT * FROM fstree" query on this table returns the entire
** contents of the file-system, starting at "/". To restrict the search
** space, the virtual table supports LIKE and GLOB constraints on the
** 'path' column. For example:
**
**   SELECT * FROM fstree WHERE path LIKE '/home/dan/sqlite/%'
*/
#include "sqliteInt.h"
#include "tcl.h"

#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

#if SQLITE_OS_UNIX
# include <unistd.h>
# include <dirent.h>
# ifndef DIRENT
#  define DIRENT dirent
# endif
#endif
#if SQLITE_OS_WIN
# include <io.h>
# include "test_windirent.h"
# ifndef S_ISREG
#  define S_ISREG(mode) (((mode) & S_IFMT) == S_IFREG)
# endif
#endif

#ifndef SQLITE_OMIT_VIRTUALTABLE

typedef struct fs_vtab fs_vtab;
typedef struct fs_cursor fs_cursor;

struct fs_cursor {
  sqlite3_vtab_cursor base;
  sqlite3_stmt *pStmt;
  char *zBuf;
  int nBuf;
  int nAlloc;
};

/*************************************************************************
** Start of fsdir implementation.
*/
typedef struct FsdirVtab FsdirVtab;
typedef struct FsdirCsr FsdirCsr;
struct FsdirVtab {
  sqlite3_vtab base;
};

struct FsdirCsr {
  sqlite3_vtab_cursor base;
  char *zDir;                     /* Buffer containing directory scanned */
  DIR *pDir;                      /* Open directory */
  sqlite3_int64 iRowid;
  struct DIRENT entry;            /* Current entry */
};

/*
** This function is the implementation of both the xConnect and xCreate
** methods of the fsdir virtual table.
**
** The argv[] array contains the following:
**
**   argv[0]   -> module name  ("fs")
**   argv[1]   -> database name
**   argv[2]   -> table name
**   argv[...] -> other module argument fields.
*/
static int fsdirConnect(
  sqlite3 *db,
  void *pAux,
  int argc, const char *const*argv,
  sqlite3_vtab **ppVtab,
  char **pzErr
){
  FsdirVtab *pTab;

  if( argc!=3 ){
    *pzErr = sqlite3_mprintf("wrong number of arguments");
    return SQLITE_ERROR;
  }

  pTab = (FsdirVtab *)sqlite3_malloc(sizeof(FsdirVtab));
  if( !pTab ) return SQLITE_NOMEM;
  memset(pTab, 0, sizeof(FsdirVtab));

  *ppVtab = &pTab->base;
  sqlite3_declare_vtab(db, "CREATE TABLE xyz(dir, name);");

  return SQLITE_OK;
}

/*
** xDestroy/xDisconnect implementation.
*/
static int fsdirDisconnect(sqlite3_vtab *pVtab){
  sqlite3_free(pVtab);
  return SQLITE_OK;
}

/*
** xBestIndex implementation. The only constraint supported is:
**
**   (dir = ?)
*/
static int fsdirBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
  int ii;

  pIdxInfo->estimatedCost = 1000000000.0;

  for(ii=0; ii<pIdxInfo->nConstraint; ii++){
    struct sqlite3_index_constraint const *p = &pIdxInfo->aConstraint[ii];
    if( p->iColumn==0 && p->usable && p->op==SQLITE_INDEX_CONSTRAINT_EQ ){
      struct sqlite3_index_constraint_usage *pUsage;
      pUsage = &pIdxInfo->aConstraintUsage[ii];
      pUsage->omit = 1;
      pUsage->argvIndex = 1;
      pIdxInfo->idxNum = 1;
      pIdxInfo->estimatedCost = 1.0;
      break;
    }
  }

  return SQLITE_OK;
}

/*
** xOpen implementation.
**
** Open a new fsdir cursor.
*/
static int fsdirOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
  FsdirCsr *pCur;
  pCur = (FsdirCsr*)sqlite3_malloc(sizeof(FsdirCsr));
  if( pCur==0 ) return SQLITE_NOMEM;
  memset(pCur, 0, sizeof(FsdirCsr));
  *ppCursor = &pCur->base;
  return SQLITE_OK;
}

/*
** Close a fsdir cursor.
*/
static int fsdirClose(sqlite3_vtab_cursor *cur){
  FsdirCsr *pCur = (FsdirCsr*)cur;
  if( pCur->pDir ) closedir(pCur->pDir);
  sqlite3_free(pCur->zDir);
  sqlite3_free(pCur);
  return SQLITE_OK;
}

/*
** Skip the cursor to the next entry.
*/
static int fsdirNext(sqlite3_vtab_cursor *cur){
  FsdirCsr *pCsr = (FsdirCsr*)cur;

  if( pCsr->pDir ){
    struct DIRENT *pRes = 0;
    readdir_r(pCsr->pDir, &pCsr->entry, &pRes);
    if( pRes==0 ){
      closedir(pCsr->pDir);
      pCsr->pDir = 0;
    }
    pCsr->iRowid++;
  }

  return SQLITE_OK;
}

/*
** xFilter method implementation.
*/
static int fsdirFilter(
  sqlite3_vtab_cursor *pVtabCursor, 
  int idxNum, const char *idxStr,
  int argc, sqlite3_value **argv
){
  FsdirCsr *pCsr = (FsdirCsr*)pVtabCursor;
  const char *zDir;
  int nDir;


  if( idxNum!=1 || argc!=1 ){
    return SQLITE_ERROR;
  }

  pCsr->iRowid = 0;
  sqlite3_free(pCsr->zDir);
  if( pCsr->pDir ){
    closedir(pCsr->pDir);
    pCsr->pDir = 0;
  }

  zDir = (const char*)sqlite3_value_text(argv[0]);
  nDir = sqlite3_value_bytes(argv[0]);
  pCsr->zDir = sqlite3_malloc(nDir+1);
  if( pCsr->zDir==0 ) return SQLITE_NOMEM;
  memcpy(pCsr->zDir, zDir, nDir+1);

  pCsr->pDir = opendir(pCsr->zDir);
  return fsdirNext(pVtabCursor); 
}

/*
** xEof method implementation.
*/
static int fsdirEof(sqlite3_vtab_cursor *cur){
  FsdirCsr *pCsr = (FsdirCsr*)cur;
  return pCsr->pDir==0;
}

/*
** xColumn method implementation.
*/
static int fsdirColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){
  FsdirCsr *pCsr = (FsdirCsr*)cur;
  switch( i ){
    case 0: /* dir */
      sqlite3_result_text(ctx, pCsr->zDir, -1, SQLITE_STATIC);
      break;

    case 1: /* name */
      sqlite3_result_text(ctx, pCsr->entry.d_name, -1, SQLITE_TRANSIENT);
      break;

    default:
      assert( 0 );
  }

  return SQLITE_OK;
}

/*
** xRowid method implementation.
*/
static int fsdirRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){
  FsdirCsr *pCsr = (FsdirCsr*)cur;
  *pRowid = pCsr->iRowid;
  return SQLITE_OK;
}
/*
** End of fsdir implementation.
*************************************************************************/

/*************************************************************************
** Start of fstree implementation.
*/
typedef struct FstreeVtab FstreeVtab;
typedef struct FstreeCsr FstreeCsr;
struct FstreeVtab {
  sqlite3_vtab base;
  sqlite3 *db;
};

struct FstreeCsr {
  sqlite3_vtab_cursor base;
  sqlite3_stmt *pStmt;            /* Statement to list paths */
  int fd;                         /* File descriptor open on current path */
};

/*
** This function is the implementation of both the xConnect and xCreate
** methods of the fstree virtual table.
**
** The argv[] array contains the following:
**
**   argv[0]   -> module name  ("fs")
**   argv[1]   -> database name
**   argv[2]   -> table name
**   argv[...] -> other module argument fields.
*/
static int fstreeConnect(
  sqlite3 *db,
  void *pAux,
  int argc, const char *const*argv,
  sqlite3_vtab **ppVtab,
  char **pzErr
){
  FstreeVtab *pTab;

  if( argc!=3 ){
    *pzErr = sqlite3_mprintf("wrong number of arguments");
    return SQLITE_ERROR;
  }

  pTab = (FstreeVtab *)sqlite3_malloc(sizeof(FstreeVtab));
  if( !pTab ) return SQLITE_NOMEM;
  memset(pTab, 0, sizeof(FstreeVtab));
  pTab->db = db;

  *ppVtab = &pTab->base;
  sqlite3_declare_vtab(db, "CREATE TABLE xyz(path, size, data);");

  return SQLITE_OK;
}

/*
** xDestroy/xDisconnect implementation.
*/
static int fstreeDisconnect(sqlite3_vtab *pVtab){
  sqlite3_free(pVtab);
  return SQLITE_OK;
}

/*
** xBestIndex implementation. The only constraint supported is:
**
**   (dir = ?)
*/
static int fstreeBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
  int ii;

  for(ii=0; ii<pIdxInfo->nConstraint; ii++){
    struct sqlite3_index_constraint const *p = &pIdxInfo->aConstraint[ii];
    if( p->iColumn==0 && p->usable && (
          p->op==SQLITE_INDEX_CONSTRAINT_GLOB
       || p->op==SQLITE_INDEX_CONSTRAINT_LIKE
       || p->op==SQLITE_INDEX_CONSTRAINT_EQ
    )){
      struct sqlite3_index_constraint_usage *pUsage;
      pUsage = &pIdxInfo->aConstraintUsage[ii];
      pIdxInfo->idxNum = p->op;
      pUsage->argvIndex = 1;
      pIdxInfo->estimatedCost = 100000.0;
      return SQLITE_OK;
    }
  }

  pIdxInfo->estimatedCost = 1000000000.0;
  return SQLITE_OK;
}

/*
** xOpen implementation.
**
** Open a new fstree cursor.
*/
static int fstreeOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
  FstreeCsr *pCur;
  pCur = (FstreeCsr*)sqlite3_malloc(sizeof(FstreeCsr));
  if( pCur==0 ) return SQLITE_NOMEM;
  memset(pCur, 0, sizeof(FstreeCsr));
  pCur->fd = -1;
  *ppCursor = &pCur->base;
  return SQLITE_OK;
}

static void fstreeCloseFd(FstreeCsr *pCsr){
  if( pCsr->fd>=0 ){
    close(pCsr->fd);
    pCsr->fd = -1;
  }
}

/*
** Close a fstree cursor.
*/
static int fstreeClose(sqlite3_vtab_cursor *cur){
  FstreeCsr *pCsr = (FstreeCsr*)cur;
  sqlite3_finalize(pCsr->pStmt);
  fstreeCloseFd(pCsr);
  sqlite3_free(pCsr);
  return SQLITE_OK;
}

/*
** Skip the cursor to the next entry.
*/
static int fstreeNext(sqlite3_vtab_cursor *cur){
  FstreeCsr *pCsr = (FstreeCsr*)cur;
  int rc;

  fstreeCloseFd(pCsr);
  rc = sqlite3_step(pCsr->pStmt);
  if( rc!=SQLITE_ROW ){
    rc = sqlite3_finalize(pCsr->pStmt);
    pCsr->pStmt = 0;
  }else{
    rc = SQLITE_OK;
    pCsr->fd = open((const char*)sqlite3_column_text(pCsr->pStmt, 0), O_RDONLY);
  }

  return rc;
}

/*
** xFilter method implementation.
*/
static int fstreeFilter(
  sqlite3_vtab_cursor *pVtabCursor, 
  int idxNum, const char *idxStr,
  int argc, sqlite3_value **argv
){
  FstreeCsr *pCsr = (FstreeCsr*)pVtabCursor;
  FstreeVtab *pTab = (FstreeVtab*)(pCsr->base.pVtab);
  int rc;
  const char *zSql = 
"WITH r(d) AS ("
"  SELECT CASE WHEN dir=?2 THEN ?3 ELSE dir END || '/' || name "
"    FROM fsdir WHERE dir=?1 AND name NOT LIKE '.%'"
"  UNION ALL"
"  SELECT dir || '/' || name FROM r, fsdir WHERE dir=d AND name NOT LIKE '.%'"
") SELECT d FROM r;";

  char *zRoot;
  int nRoot;
  char *zPrefix;
  int nPrefix;
  const char *zDir;
  int nDir;
  char aWild[2] = { '\0', '\0' };

#if SQLITE_OS_WIN
  zRoot = sqlite3_mprintf("%s%c", getenv("SystemDrive"), '/');
  nRoot = strlen(zRoot);
  zPrefix = sqlite3_mprintf("%s", getenv("SystemDrive"));
  nPrefix = strlen(zPrefix);
#else
  zRoot = "/";
  nRoot = 1;
  zPrefix = "";
  nPrefix = 0;
#endif

  zDir = zRoot;
  nDir = nRoot;

  fstreeCloseFd(pCsr);
  sqlite3_finalize(pCsr->pStmt);
  pCsr->pStmt = 0;
  rc = sqlite3_prepare_v2(pTab->db, zSql, -1, &pCsr->pStmt, 0);
  if( rc!=SQLITE_OK ) return rc;

  if( idxNum ){
    const char *zQuery = (const char*)sqlite3_value_text(argv[0]);
    switch( idxNum ){
      case SQLITE_INDEX_CONSTRAINT_GLOB:
        aWild[0] = '*';
        aWild[1] = '?';
        break;
      case SQLITE_INDEX_CONSTRAINT_LIKE:
        aWild[0] = '_';
        aWild[1] = '%';
        break;
    }

    if( sqlite3_strnicmp(zQuery, zPrefix, nPrefix)==0 ){
      int i;
      for(i=nPrefix; zQuery[i]; i++){
        if( zQuery[i]==aWild[0] || zQuery[i]==aWild[1] ) break;
        if( zQuery[i]=='/' ) nDir = i;
      }
      zDir = zQuery;
    }
  }

  sqlite3_bind_text(pCsr->pStmt, 1, zDir, nDir, SQLITE_TRANSIENT);
  sqlite3_bind_text(pCsr->pStmt, 2, zRoot, nRoot, SQLITE_TRANSIENT);
  sqlite3_bind_text(pCsr->pStmt, 3, zPrefix, nPrefix, SQLITE_TRANSIENT);

#if SQLITE_OS_WIN
  sqlite3_free(zPrefix);
  sqlite3_free(zRoot);
#endif

  return fstreeNext(pVtabCursor); 
}

/*
** xEof method implementation.
*/
static int fstreeEof(sqlite3_vtab_cursor *cur){
  FstreeCsr *pCsr = (FstreeCsr*)cur;
  return pCsr->pStmt==0;
}

/*
** xColumn method implementation.
*/
static int fstreeColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){
  FstreeCsr *pCsr = (FstreeCsr*)cur;
  if( i==0 ){      /* path */
    sqlite3_result_value(ctx, sqlite3_column_value(pCsr->pStmt, 0));
  }else{
    struct stat sBuf;
    fstat(pCsr->fd, &sBuf);

    if( S_ISREG(sBuf.st_mode) ){
      if( i==1 ){
        sqlite3_result_int64(ctx, sBuf.st_size);
      }else{
        int nRead;
        char *aBuf = sqlite3_malloc(sBuf.st_mode+1);
        if( !aBuf ) return SQLITE_NOMEM;
        nRead = read(pCsr->fd, aBuf, sBuf.st_mode);
        if( nRead!=sBuf.st_mode ){
          return SQLITE_IOERR;
        }
        sqlite3_result_blob(ctx, aBuf, nRead, SQLITE_TRANSIENT);
        sqlite3_free(aBuf);
      }
    }
  }

  return SQLITE_OK;
}

/*
** xRowid method implementation.
*/
static int fstreeRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){
  *pRowid = 0;
  return SQLITE_OK;
}
/*
** End of fstree implementation.
*************************************************************************/




/*
** This function is the implementation of both the xConnect and xCreate
** methods of the fs virtual table.
**
** The argv[] array contains the following:
**

  pVtab->zTbl = (char *)&pVtab[1];
  pVtab->zDb = &pVtab->zTbl[strlen(zTbl)+1];
  pVtab->db = db;
  memcpy(pVtab->zTbl, zTbl, strlen(zTbl));
  memcpy(pVtab->zDb, zDb, strlen(zDb));
  *ppVtab = &pVtab->base;
  sqlite3_declare_vtab(db, "CREATE TABLE x(path TEXT, data TEXT)");

  return SQLITE_OK;
}
/* Note that for this virtual table, the xCreate and xConnect
** methods are identical. */

static int fsDisconnect(sqlite3_vtab *pVtab){

  }
  return rc;
}

static int fsColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){
  fs_cursor *pCur = (fs_cursor*)cur;

  assert( i==0 || i==1 || i==2 );
  if( i==0 ){
    sqlite3_result_value(ctx, sqlite3_column_value(pCur->pStmt, 0));
  }else{
    const char *zFile = (const char *)sqlite3_column_text(pCur->pStmt, 1);
    struct stat sbuf;
    int fd;


    int n;
    fd = open(zFile, O_RDONLY);
    if( fd<0 ) return SQLITE_IOERR;
    fstat(fd, &sbuf);

    if( sbuf.st_size>=pCur->nAlloc ){
      int nNew = sbuf.st_size*2;
      char *zNew;

  0,                           /* xSync */
  0,                           /* xCommit */
  0,                           /* xRollback */
  0,                           /* xFindMethod */
  0,                           /* xRename */
};

static sqlite3_module fsdirModule = {
  0,                              /* iVersion */
  fsdirConnect,                   /* xCreate */
  fsdirConnect,                   /* xConnect */
  fsdirBestIndex,                 /* xBestIndex */
  fsdirDisconnect,                /* xDisconnect */
  fsdirDisconnect,                /* xDestroy */
  fsdirOpen,                      /* xOpen - open a cursor */
  fsdirClose,                     /* xClose - close a cursor */
  fsdirFilter,                    /* xFilter - configure scan constraints */
  fsdirNext,                      /* xNext - advance a cursor */
  fsdirEof,                       /* xEof - check for end of scan */
  fsdirColumn,                    /* xColumn - read data */
  fsdirRowid,                     /* xRowid - read data */
  0,                              /* xUpdate */
  0,                              /* xBegin */
  0,                              /* xSync */
  0,                              /* xCommit */
  0,                              /* xRollback */
  0,                              /* xFindMethod */
  0,                              /* xRename */
};

static sqlite3_module fstreeModule = {
  0,                              /* iVersion */
  fstreeConnect,                  /* xCreate */
  fstreeConnect,                  /* xConnect */
  fstreeBestIndex,                /* xBestIndex */
  fstreeDisconnect,               /* xDisconnect */
  fstreeDisconnect,               /* xDestroy */
  fstreeOpen,                     /* xOpen - open a cursor */
  fstreeClose,                    /* xClose - close a cursor */
  fstreeFilter,                   /* xFilter - configure scan constraints */
  fstreeNext,                     /* xNext - advance a cursor */
  fstreeEof,                      /* xEof - check for end of scan */
  fstreeColumn,                   /* xColumn - read data */
  fstreeRowid,                    /* xRowid - read data */
  0,                              /* xUpdate */
  0,                              /* xBegin */
  0,                              /* xSync */
  0,                              /* xCommit */
  0,                              /* xRollback */
  0,                              /* xFindMethod */
  0,                              /* xRename */
};

/*
** Decode a pointer to an sqlite3 object.
*/
extern int getDbPointer(Tcl_Interp *interp, const char *zA, sqlite3 **ppDb);

/*
** Register the echo virtual table module.

  if( objc!=2 ){
    Tcl_WrongNumArgs(interp, 1, objv, "DB");
    return TCL_ERROR;
  }
  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
#ifndef SQLITE_OMIT_VIRTUALTABLE
  sqlite3_create_module(db, "fs", &fsModule, (void *)interp);
  sqlite3_create_module(db, "fsdir", &fsdirModule, 0);
  sqlite3_create_module(db, "fstree", &fstreeModule, 0);
#endif
  return TCL_OK;
}

#endif

    return TCL_ERROR;
  }
  if( Tcl_GetIntFromObj(interp, objv[1], &sz) ) return TCL_ERROR;
  if( Tcl_GetIntFromObj(interp, objv[2], &N) ) return TCL_ERROR;
  free(buf);
  if( sz<0 ){
    buf = 0;
    rc = sqlite3_config(SQLITE_CONFIG_SCRATCH, (void*)0, 0, 0);
  }else{
    buf = malloc( sz*N + 1 );
    rc = sqlite3_config(SQLITE_CONFIG_SCRATCH, buf, sz, N);
  }
  pResult = Tcl_NewObj();
  Tcl_ListObjAppendElement(0, pResult, Tcl_NewIntObj(rc));
  Tcl_ListObjAppendElement(0, pResult, Tcl_NewIntObj(N));

  /* Set the return value */
  pRes = Tcl_NewObj();
  Tcl_ListObjAppendElement(0, pRes, Tcl_NewIntObj(sqlite3GlobalConfig.szPage));
  Tcl_ListObjAppendElement(0, pRes, Tcl_NewIntObj(sqlite3GlobalConfig.nPage));
  Tcl_SetObjResult(interp, pRes);

  if( sz<0 ){
    sqlite3_config(SQLITE_CONFIG_PAGECACHE, (void*)0, 0, 0);
  }else{
    buf = malloc( sz*N );
    sqlite3_config(SQLITE_CONFIG_PAGECACHE, buf, sz, N);
  }
  return TCL_OK;
}

#include "sqliteInt.h"
#include "tcl.h"
#include <stdlib.h>
#include <string.h>

#ifndef SQLITE_OMIT_VIRTUALTABLE

/*
** Characters that make up the idxStr created by xBestIndex for xFilter.
*/
#define TCLVAR_NAME_EQ      'e'
#define TCLVAR_NAME_MATCH   'm'
#define TCLVAR_VALUE_GLOB   'g'
#define TCLVAR_VALUE_REGEXP 'r'
#define TCLVAR_VALUE_LIKE   'l'

typedef struct tclvar_vtab tclvar_vtab;
typedef struct tclvar_cursor tclvar_cursor;

/* 
** A tclvar virtual-table object 
*/
struct tclvar_vtab {

static int tclvarFilter(
  sqlite3_vtab_cursor *pVtabCursor, 
  int idxNum, const char *idxStr,
  int argc, sqlite3_value **argv
){
  tclvar_cursor *pCur = (tclvar_cursor *)pVtabCursor;
  Tcl_Interp *interp = ((tclvar_vtab *)(pVtabCursor->pVtab))->interp;
  Tcl_Obj *p = Tcl_NewStringObj("tclvar_filter_cmd", -1);

  const char *zEq = "";
  const char *zMatch = "";
  const char *zGlob = "";
  const char *zRegexp = "";
  const char *zLike = "";
  int i;

  for(i=0; idxStr[i]; i++){
    switch( idxStr[i] ){
      case TCLVAR_NAME_EQ:
        zEq = (const char*)sqlite3_value_text(argv[i]);
        break;
      case TCLVAR_NAME_MATCH:
        zMatch = (const char*)sqlite3_value_text(argv[i]);
        break;
      case TCLVAR_VALUE_GLOB:
        zGlob = (const char*)sqlite3_value_text(argv[i]);
        break;
      case TCLVAR_VALUE_REGEXP:
        zRegexp = (const char*)sqlite3_value_text(argv[i]);
        break;
      case TCLVAR_VALUE_LIKE:
        zLike = (const char*)sqlite3_value_text(argv[i]);
        break;
      default:
        assert( 0 );
    }
  }

  Tcl_IncrRefCount(p);
  Tcl_ListObjAppendElement(0, p, Tcl_NewStringObj(zEq, -1));
  Tcl_ListObjAppendElement(0, p, Tcl_NewStringObj(zMatch, -1));
  Tcl_ListObjAppendElement(0, p, Tcl_NewStringObj(zGlob, -1));
  Tcl_ListObjAppendElement(0, p, Tcl_NewStringObj(zRegexp, -1));
  Tcl_ListObjAppendElement(0, p, Tcl_NewStringObj(zLike, -1));

  Tcl_EvalObjEx(interp, p, TCL_EVAL_GLOBAL);
  if( pCur->pList1 ){
    Tcl_DecrRefCount(pCur->pList1);
  }
  if( pCur->pList2 ){
    Tcl_DecrRefCount(pCur->pList2);
    pCur->pList2 = 0;
  }
  pCur->i1 = 0;
  pCur->i2 = 0;
  pCur->pList1 = Tcl_GetObjResult(interp);
  Tcl_IncrRefCount(pCur->pList1);


  Tcl_DecrRefCount(p);
  return tclvarNext(pVtabCursor);
}

static int tclvarColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){
  Tcl_Obj *p1;

}

static int tclvarEof(sqlite3_vtab_cursor *cur){
  tclvar_cursor *pCur = (tclvar_cursor*)cur;
  return (pCur->pList2?0:1);
}

/*
** If nul-terminated string zStr does not already contain the character 
** passed as the second argument, append it and return 0. Or, if there is
** already an instance of x in zStr, do nothing return 1;
**
** There is guaranteed to be enough room in the buffer pointed to by zStr
** for the new character and nul-terminator.
*/
static int tclvarAddToIdxstr(char *zStr, char x){
  int i;
  for(i=0; zStr[i]; i++){
    if( zStr[i]==x ) return 1;
  }
  zStr[i] = x;
  zStr[i+1] = '\0';
  return 0;
}





/*
** Return true if variable $::tclvar_set_omit exists and is set to true.
** False otherwise.
*/
static int tclvarSetOmit(Tcl_Interp *interp){
  int rc;
  int res = 0;
  Tcl_Obj *pRes;
  rc = Tcl_Eval(interp,
    "expr {[info exists ::tclvar_set_omit] && $::tclvar_set_omit}"
  );
  if( rc==TCL_OK ){
    pRes = Tcl_GetObjResult(interp);
    rc = Tcl_GetBooleanFromObj(0, pRes, &res);
  }
  return (rc==TCL_OK && res);
}

/*
** The xBestIndex() method. This virtual table supports the following
** operators:
**
**     name = ?                    (omit flag clear)
**     name MATCH ?                (omit flag set)
**     value GLOB ?                (omit flag set iff $::tclvar_set_omit)
**     value REGEXP ?              (omit flag set iff $::tclvar_set_omit)
**     value LIKE ?                (omit flag set iff $::tclvar_set_omit)
**
** For each constraint present, the corresponding TCLVAR_XXX character is
** appended to the idxStr value. 
*/
static int tclvarBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
  tclvar_vtab *pTab = (tclvar_vtab*)tab;
  int ii;
  char *zStr = sqlite3_malloc(32);
  int iStr = 0;

  if( zStr==0 ) return SQLITE_NOMEM;
  zStr[0] = '\0';

  for(ii=0; ii<pIdxInfo->nConstraint; ii++){
    struct sqlite3_index_constraint const *pCons = &pIdxInfo->aConstraint[ii];


    struct sqlite3_index_constraint_usage *pUsage;
    
    pUsage = &pIdxInfo->aConstraintUsage[ii];
    if( pCons->usable ){
      /* name = ? */
      if( pCons->op==SQLITE_INDEX_CONSTRAINT_EQ && pCons->iColumn==0 ){
        if( 0==tclvarAddToIdxstr(zStr, TCLVAR_NAME_EQ) ){
          pUsage->argvIndex = ++iStr;
          pUsage->omit = 0;
        }
      }

      /* name MATCH ? */
      if( pCons->op==SQLITE_INDEX_CONSTRAINT_MATCH && pCons->iColumn==0 ){
        if( 0==tclvarAddToIdxstr(zStr, TCLVAR_NAME_MATCH) ){
          pUsage->argvIndex = ++iStr;
          pUsage->omit = 1;
        }
      }

      /* value GLOB ? */
      if( pCons->op==SQLITE_INDEX_CONSTRAINT_GLOB && pCons->iColumn==2 ){
        if( 0==tclvarAddToIdxstr(zStr, TCLVAR_VALUE_GLOB) ){
          pUsage->argvIndex = ++iStr;
          pUsage->omit = tclvarSetOmit(pTab->interp);
        }
      }

      /* value REGEXP ? */
      if( pCons->op==SQLITE_INDEX_CONSTRAINT_REGEXP && pCons->iColumn==2 ){
        if( 0==tclvarAddToIdxstr(zStr, TCLVAR_VALUE_REGEXP) ){
          pUsage->argvIndex = ++iStr;
          pUsage->omit = tclvarSetOmit(pTab->interp);
        }
      }

      /* value LIKE ? */
      if( pCons->op==SQLITE_INDEX_CONSTRAINT_LIKE && pCons->iColumn==2 ){
        if( 0==tclvarAddToIdxstr(zStr, TCLVAR_VALUE_LIKE) ){
          pUsage->argvIndex = ++iStr;
          pUsage->omit = tclvarSetOmit(pTab->interp);
        }
      }
    }
  }
  pIdxInfo->idxStr = zStr;
  pIdxInfo->needToFreeIdxStr = 1;

  return SQLITE_OK;
}

/*
** A virtual table module that provides read-only access to a
** Tcl global variable namespace.

*/
static int register_tclvar_module(
  ClientData clientData, /* Pointer to sqlite3_enable_XXX function */
  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
  int objc,              /* Number of arguments */
  Tcl_Obj *CONST objv[]  /* Command arguments */
){
  int rc = TCL_OK;
  sqlite3 *db;
  if( objc!=2 ){
    Tcl_WrongNumArgs(interp, 1, objv, "DB");
    return TCL_ERROR;
  }
  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
#ifndef SQLITE_OMIT_VIRTUALTABLE
  sqlite3_create_module(db, "tclvar", &tclvarModule, (void*)interp);
  rc = Tcl_Eval(interp, 
      "proc like {pattern str} {\n"
      "  set p [string map {% * _ ?} $pattern]\n"
      "  string match $p $str\n"
      "}\n"
      "proc tclvar_filter_cmd {eq match glob regexp like} {\n"
      "  set res {}\n"
      "  set pattern $eq\n"
      "  if {$pattern=={}} { set pattern $match }\n"
      "  if {$pattern=={}} { set pattern * }\n"
      "  foreach v [uplevel #0 info vars $pattern] {\n"
      "    if {($glob=={} || [string match $glob [uplevel #0 set $v]])\n"
      "     && ($like=={} || [like $like [uplevel #0 set $v]])\n"
      "     && ($regexp=={} || [regexp $regexp [uplevel #0 set $v]])\n"
      "    } {\n"
      "      lappend res $v\n"
      "    }\n"
      "  }\n"
      "  set res\n"
      "}\n"
  );
#endif
  return rc;
}

#endif


/*
** Register commands with the TCL interpreter.

/*
** 2015 November 30
**
** 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 contains code to implement most of the opendir() family of
** POSIX functions on Win32 using the MSVCRT.
*/

#if defined(_WIN32) && defined(_MSC_VER)

#include "test_windirent.h"

/*
** Implementation of the POSIX opendir() function using the MSVCRT.
*/
LPDIR opendir(
  const char *dirname
){
  struct _finddata_t data;
  LPDIR dirp = (LPDIR)sqlite3_malloc(sizeof(DIR));
  SIZE_T namesize = sizeof(data.name) / sizeof(data.name[0]);

  if( dirp==NULL ) return NULL;
  memset(dirp, 0, sizeof(DIR));

  /* TODO: Remove this if Unix-style root paths are not used. */
  if( sqlite3_stricmp(dirname, "/")==0 ){
    dirname = getenv("SystemDrive");
  }

  _snprintf(data.name, namesize, "%s\\*", dirname);
  dirp->d_handle = _findfirst(data.name, &data);

  if( dirp->d_handle==BAD_INTPTR_T ){
    closedir(dirp);
    return NULL;
  }

  /* TODO: Remove this block to allow hidden and system files. */
  if( data.attrib&_A_HIDDEN || data.attrib&_A_SYSTEM ){
    if( _findnext(dirp->d_handle, &data)==-1 ){
      closedir(dirp);
      return NULL;
    }
  }

  dirp->d_first.d_attributes = data.attrib;
  strncpy(dirp->d_first.d_name, data.name, NAME_MAX);
  dirp->d_first.d_name[NAME_MAX] = '\0';

  return dirp;
}

/*
** Implementation of the POSIX readdir() function using the MSVCRT.
*/
LPDIRENT readdir(
  LPDIR dirp
){
  struct _finddata_t data;

  if( dirp==NULL ) return NULL;

  if( dirp->d_first.d_ino==0 ){
    dirp->d_first.d_ino++;
    dirp->d_next.d_ino++;

    return &dirp->d_first;
  }

next:

  if( _findnext(dirp->d_handle, &data)==-1 ) return NULL;

  /* TODO: Remove this block to allow hidden and system files. */
  if( data.attrib&_A_HIDDEN ) goto next;
  if( data.attrib&_A_SYSTEM ) goto next;

  dirp->d_next.d_ino++;
  dirp->d_next.d_attributes = data.attrib;
  strncpy(dirp->d_next.d_name, data.name, NAME_MAX);
  dirp->d_next.d_name[NAME_MAX] = '\0';

  return &dirp->d_next;
}

/*
** Implementation of the POSIX readdir_r() function using the MSVCRT.
*/
INT readdir_r(
  LPDIR dirp,
  LPDIRENT entry,
  LPDIRENT *result
){
  struct _finddata_t data;

  if( dirp==NULL ) return EBADF;

  if( dirp->d_first.d_ino==0 ){
    dirp->d_first.d_ino++;
    dirp->d_next.d_ino++;

    entry->d_ino = dirp->d_first.d_ino;
    entry->d_attributes = dirp->d_first.d_attributes;
    strncpy(entry->d_name, dirp->d_first.d_name, NAME_MAX);
    entry->d_name[NAME_MAX] = '\0';

    *result = entry;
    return 0;
  }

next:

  if( _findnext(dirp->d_handle, &data)==-1 ){
    *result = NULL;
    return ENOENT;
  }

  /* TODO: Remove this block to allow hidden and system files. */
  if( data.attrib&_A_HIDDEN ) goto next;
  if( data.attrib&_A_SYSTEM ) goto next;

  entry->d_ino = (ino_t)-1; /* not available */
  entry->d_attributes = data.attrib;
  strncpy(entry->d_name, data.name, NAME_MAX);
  entry->d_name[NAME_MAX] = '\0';

  *result = entry;
  return 0;
}

/*
** Implementation of the POSIX closedir() function using the MSVCRT.
*/
INT closedir(
  LPDIR dirp
){
  INT result = 0;

  if( dirp==NULL ) return EINVAL;

  if( dirp->d_handle!=NULL_INTPTR_T && dirp->d_handle!=BAD_INTPTR_T ){
    result = _findclose(dirp->d_handle);
  }

  sqlite3_free(dirp);
  return result;
}

#endif /* defined(WIN32) && defined(_MSC_VER) */

/*
** 2015 November 30
**
** 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 contains declarations for most of the opendir() family of
** POSIX functions on Win32 using the MSVCRT.
*/

#if defined(_WIN32) && defined(_MSC_VER)

/*
** We need several data types from the Windows SDK header.
*/

#define WIN32_LEAN_AND_MEAN
#include "windows.h"

/*
** We need several support functions from the SQLite core.
*/

#include "sqlite3.h"

/*
** We need several things from the ANSI and MSVCRT headers.
*/

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <io.h>
#include <limits.h>

/*
** We may need to provide the "ino_t" type.
*/

#ifndef INO_T_DEFINED
  #define INO_T_DEFINED
  typedef unsigned short ino_t;
#endif

/*
** We need to define "NAME_MAX" if it was not present in "limits.h".
*/

#ifndef NAME_MAX
#  ifdef FILENAME_MAX
#    define NAME_MAX (FILENAME_MAX)
#  else
#    define NAME_MAX (260)
#  endif
#endif

/*
** We need to define "NULL_INTPTR_T" and "BAD_INTPTR_T".
*/

#ifndef NULL_INTPTR_T
#  define NULL_INTPTR_T ((intptr_t)(0))
#endif

#ifndef BAD_INTPTR_T
#  define BAD_INTPTR_T ((intptr_t)(-1))
#endif

/*
** We need to provide the necessary structures and related types.
*/

typedef struct DIRENT DIRENT;
typedef struct DIR DIR;
typedef DIRENT *LPDIRENT;
typedef DIR *LPDIR;

struct DIRENT {
  ino_t d_ino;               /* Sequence number, do not use. */
  unsigned d_attributes;     /* Win32 file attributes. */
  char d_name[NAME_MAX + 1]; /* Name within the directory. */
};

struct DIR {
  intptr_t d_handle; /* Value returned by "_findfirst". */
  DIRENT d_first;    /* DIRENT constructed based on "_findfirst". */
  DIRENT d_next;     /* DIRENT constructed based on "_findnext". */
};

/*
** Finally, we can provide the function prototypes for the opendir(),
** readdir(), readdir_r(), and closedir() POSIX functions.
*/

extern LPDIR opendir(const char *dirname);
extern LPDIRENT readdir(LPDIR dirp);
extern INT readdir_r(LPDIR dirp, LPDIRENT entry, LPDIRENT *result);
extern INT closedir(LPDIR dirp);

#endif /* defined(WIN32) && defined(_MSC_VER) */

#endif
  }
  assert( (chngRowid & chngPk)==0 );
  assert( chngRowid==0 || chngRowid==1 );
  assert( chngPk==0 || chngPk==1 );
  chngKey = chngRowid + chngPk;

  /* The SET expressions are not actually used inside the WHERE loop.  
  ** So reset the colUsed mask. Unless this is a virtual table. In that
  ** case, set all bits of the colUsed mask (to ensure that the virtual
  ** table implementation makes all columns available).
  */
  pTabList->a[0].colUsed = IsVirtual(pTab) ? (Bitmask)-1 : 0;

  hasFK = sqlite3FkRequired(pParse, pTab, aXRef, chngKey);

  /* There is one entry in the aRegIdx[] array for each index on the table
  ** being updated.  Fill in aRegIdx[] with a register number that will hold
  ** the key for accessing each index.
  **

    *pNum = -(i64)u;
  }else{
    *pNum = (i64)u;
  }
  testcase( i==18 );
  testcase( i==19 );
  testcase( i==20 );
  if( (c!=0 && &zNum[i]<zEnd) || (i==0 && zStart==zNum)
       || i>19*incr || nonNum ){
    /* zNum is empty or contains non-numeric text or is longer
    ** than 19 digits (thus guaranteeing that it is too large) */
    return 1;
  }else if( i<19*incr ){
    /* Less than 19 digits, so we know that it fits in 64 bits */
    assert( u<=LARGEST_INT64 );
    return 0;

  p++;
  a = a<<14;
  a |= *p;
  /* a: p0<<28 | p2<<14 | p4 (unmasked) */
  if (!(a&0x80))
  {
    /* we can skip these cause they were (effectively) done above
    ** while calculating s */
    /* a &= (0x7f<<28)|(0x7f<<14)|(0x7f); */
    /* b &= (0x7f<<14)|(0x7f); */
    b = b<<7;
    a |= b;
    s = s>>18;
    *v = ((u64)s)<<32 | a;
    return 5;

** converts an MEM_Ephem string into a string with P.z==P.zMalloc.
*/
#define Deephemeralize(P) \
   if( ((P)->flags&MEM_Ephem)!=0 \
       && sqlite3VdbeMemMakeWriteable(P) ){ goto no_mem;}

/* Return true if the cursor was opened using the OP_OpenSorter opcode. */
#define isSorter(x) ((x)->eCurType==CURTYPE_SORTER)

/*
** Allocate VdbeCursor number iCur.  Return a pointer to it.  Return NULL
** if we run out of memory.
*/
static VdbeCursor *allocateCursor(
  Vdbe *p,              /* The virtual machine */
  int iCur,             /* Index of the new VdbeCursor */
  int nField,           /* Number of fields in the table or index */
  int iDb,              /* Database the cursor belongs to, or -1 */
  u8 eCurType           /* Type of the new cursor */
){
  /* Find the memory cell that will be used to store the blob of memory
  ** required for this VdbeCursor structure. It is convenient to use a 
  ** vdbe memory cell to manage the memory allocation required for a
  ** VdbeCursor structure for the following reasons:
  **
  **   * Sometimes cursor numbers are used for a couple of different

  */
  Mem *pMem = &p->aMem[p->nMem-iCur];

  int nByte;
  VdbeCursor *pCx = 0;
  nByte = 
      ROUND8(sizeof(VdbeCursor)) + 2*sizeof(u32)*nField + 
      (eCurType==CURTYPE_BTREE?sqlite3BtreeCursorSize():0);

  assert( iCur<p->nCursor );
  if( p->apCsr[iCur] ){
    sqlite3VdbeFreeCursor(p, p->apCsr[iCur]);
    p->apCsr[iCur] = 0;
  }
  if( SQLITE_OK==sqlite3VdbeMemClearAndResize(pMem, nByte) ){
    p->apCsr[iCur] = pCx = (VdbeCursor*)pMem->z;
    memset(pCx, 0, sizeof(VdbeCursor));
    pCx->eCurType = eCurType;
    pCx->iDb = iDb;
    pCx->nField = nField;
    pCx->aOffset = &pCx->aType[nField];
    if( eCurType==CURTYPE_BTREE ){
      pCx->uc.pCursor = (BtCursor*)
          &pMem->z[ROUND8(sizeof(VdbeCursor))+2*sizeof(u32)*nField];
      sqlite3BtreeCursorZero(pCx->uc.pCursor);
    }
  }
  return pCx;
}

/*
** Try to convert a value into a numeric representation if we can

  assert( pOp->p4.z!=0 );
  pOut = out2Prerelease(p, pOp);
  pOut->flags = MEM_Str|MEM_Static|MEM_Term;
  pOut->z = pOp->p4.z;
  pOut->n = pOp->p1;
  pOut->enc = encoding;
  UPDATE_MAX_BLOBSIZE(pOut);
#ifndef SQLITE_LIKE_DOESNT_MATCH_BLOBS
  if( pOp->p5 ){
    assert( pOp->p3>0 );
    assert( pOp->p3<=(p->nMem-p->nCursor) );
    pIn3 = &aMem[pOp->p3];
    assert( pIn3->flags & MEM_Int );
    if( pIn3->u.i ) pOut->flags = MEM_Blob|MEM_Static|MEM_Term;
  }
#endif
  break;
}

/* Opcode: Null P1 P2 P3 * *
** Synopsis:  r[P2..P3]=NULL
**
** Write a NULL into registers P2.  If P3 greater than P2, then also write

  pDest = &aMem[pOp->p3];
  memAboutToChange(p, pDest);
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  pC = p->apCsr[pOp->p1];
  assert( pC!=0 );
  assert( p2<pC->nField );
  aOffset = pC->aOffset;
  assert( pC->eCurType!=CURTYPE_VTAB );
  assert( pC->eCurType!=CURTYPE_PSEUDO || pC->nullRow );
  assert( pC->eCurType!=CURTYPE_SORTER );
  pCrsr = pC->uc.pCursor;



  /* If the cursor cache is stale, bring it up-to-date */
  rc = sqlite3VdbeCursorMoveto(pC);
  if( rc ) goto abort_due_to_error;
  if( pC->cacheStatus!=p->cacheCtr ){
    if( pC->nullRow ){
      if( pC->eCurType==CURTYPE_PSEUDO ){
        assert( pC->uc.pseudoTableReg>0 );
        pReg = &aMem[pC->uc.pseudoTableReg];
        assert( pReg->flags & MEM_Blob );
        assert( memIsValid(pReg) );
        pC->payloadSize = pC->szRow = avail = pReg->n;
        pC->aRow = (u8*)pReg->z;
      }else{
        sqlite3VdbeMemSetNull(pDest);
        goto op_column_out;
      }
    }else{
      assert( pC->eCurType==CURTYPE_BTREE );
      assert( pCrsr );
      if( pC->isTable==0 ){
        assert( sqlite3BtreeCursorIsValid(pCrsr) );
        VVA_ONLY(rc =) sqlite3BtreeKeySize(pCrsr, &payloadSize64);
        assert( rc==SQLITE_OK ); /* True because of CursorMoveto() call above */
        /* sqlite3BtreeParseCellPtr() uses getVarint32() to extract the
        ** payload size, so it is impossible for payloadSize64 to be

** opened by cursor P1 in register P2
*/
#ifndef SQLITE_OMIT_BTREECOUNT
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 );
  nEntry = 0;  /* Not needed.  Only used to silence a warning. */
  rc = sqlite3BtreeCount(pCrsr, &nEntry);
  pOut = out2Prerelease(p, pOp);
  pOut->u.i = nEntry;
  break;
}

    nField = pKeyInfo->nField+pKeyInfo->nXField;
  }else if( pOp->p4type==P4_INT32 ){
    nField = pOp->p4.i;
  }
  assert( pOp->p1>=0 );
  assert( nField>=0 );
  testcase( nField==0 );  /* Table with INTEGER PRIMARY KEY and nothing else */
  pCur = allocateCursor(p, pOp->p1, nField, iDb, CURTYPE_BTREE);
  if( pCur==0 ) goto no_mem;
  pCur->nullRow = 1;
  pCur->isOrdered = 1;
  pCur->pgnoRoot = p2;
  rc = sqlite3BtreeCursor(pX, p2, wrFlag, pKeyInfo, pCur->uc.pCursor);
  pCur->pKeyInfo = pKeyInfo;
  /* Set the VdbeCursor.isTable variable. Previous versions of
  ** SQLite used to check if the root-page flags were sane at this point
  ** and report database corruption if they were not, but this check has
  ** since moved into the btree layer.  */  
  pCur->isTable = pOp->p4type!=P4_KEYINFO;

open_cursor_set_hints:
  assert( OPFLAG_BULKCSR==BTREE_BULKLOAD );
  assert( OPFLAG_SEEKEQ==BTREE_SEEK_EQ );
  testcase( pOp->p5 & OPFLAG_BULKCSR );
#ifdef SQLITE_ENABLE_CURSOR_HINT
  testcase( pOp->p2 & OPFLAG_SEEKEQ );
#endif
  sqlite3BtreeCursorHintFlags(pCur->uc.pCursor,
                               (pOp->p5 & (OPFLAG_BULKCSR|OPFLAG_SEEKEQ)));
  break;
}

/* Opcode: OpenEphemeral P1 P2 * P4 P5
** Synopsis: nColumn=P2
**

      SQLITE_OPEN_READWRITE |
      SQLITE_OPEN_CREATE |
      SQLITE_OPEN_EXCLUSIVE |
      SQLITE_OPEN_DELETEONCLOSE |
      SQLITE_OPEN_TRANSIENT_DB;
  assert( pOp->p1>=0 );
  assert( pOp->p2>=0 );
  pCx = allocateCursor(p, pOp->p1, pOp->p2, -1, CURTYPE_BTREE);
  if( pCx==0 ) goto no_mem;
  pCx->nullRow = 1;
  pCx->isEphemeral = 1;
  rc = sqlite3BtreeOpen(db->pVfs, 0, db, &pCx->pBt, 
                        BTREE_OMIT_JOURNAL | BTREE_SINGLE | pOp->p5, vfsFlags);
  if( rc==SQLITE_OK ){
    rc = sqlite3BtreeBeginTrans(pCx->pBt, 1);

      assert( pOp->p4type==P4_KEYINFO );
      rc = sqlite3BtreeCreateTable(pCx->pBt, &pgno, BTREE_BLOBKEY | pOp->p5); 
      if( rc==SQLITE_OK ){
        assert( pgno==MASTER_ROOT+1 );
        assert( pKeyInfo->db==db );
        assert( pKeyInfo->enc==ENC(db) );
        pCx->pKeyInfo = pKeyInfo;
        rc = sqlite3BtreeCursor(pCx->pBt, pgno, BTREE_WRCSR,
                                pKeyInfo, pCx->uc.pCursor);
      }
      pCx->isTable = 0;
    }else{
      rc = sqlite3BtreeCursor(pCx->pBt, MASTER_ROOT, BTREE_WRCSR,
                              0, pCx->uc.pCursor);
      pCx->isTable = 1;
    }
  }
  pCx->isOrdered = (pOp->p5!=BTREE_UNORDERED);
  break;
}

** key is sufficient to produce the required results.
*/
case OP_SorterOpen: {
  VdbeCursor *pCx;

  assert( pOp->p1>=0 );
  assert( pOp->p2>=0 );
  pCx = allocateCursor(p, pOp->p1, pOp->p2, -1, CURTYPE_SORTER);
  if( pCx==0 ) goto no_mem;
  pCx->pKeyInfo = pOp->p4.pKeyInfo;
  assert( pCx->pKeyInfo->db==db );
  assert( pCx->pKeyInfo->enc==ENC(db) );
  rc = sqlite3VdbeSorterInit(db, pOp->p3, pCx);
  break;
}

/* Opcode: SequenceTest P1 P2 * * *
** Synopsis: if( cursor[P1].ctr++ ) pc = P2
**
** P1 is a sorter cursor. If the sequence counter is currently zero, jump
** to P2. Regardless of whether or not the jump is taken, increment the
** the sequence value.
*/
case OP_SequenceTest: {
  VdbeCursor *pC;
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  pC = p->apCsr[pOp->p1];
  assert( isSorter(pC) );
  if( (pC->seqCount++)==0 ){
    goto jump_to_p2;
  }
  break;
}

/* Opcode: OpenPseudo P1 P2 P3 * *

** the pseudo-table.
*/
case OP_OpenPseudo: {
  VdbeCursor *pCx;

  assert( pOp->p1>=0 );
  assert( pOp->p3>=0 );
  pCx = allocateCursor(p, pOp->p1, pOp->p3, -1, CURTYPE_PSEUDO);
  if( pCx==0 ) goto no_mem;
  pCx->nullRow = 1;
  pCx->uc.pseudoTableReg = pOp->p2;
  pCx->isTable = 1;
  assert( pOp->p5==0 );
  break;
}

/* Opcode: Close P1 * * * *
**

** first 63 columns of the table or index that are actually used
** by the cursor.  The high-order bit is set if any column after
** the 64th is used.
*/
case OP_ColumnsUsed: {
  VdbeCursor *pC;
  pC = p->apCsr[pOp->p1];
  assert( pC->eCurType==CURTYPE_BTREE );
  pC->maskUsed = *(u64*)pOp->p4.pI64;
  break;
}
#endif

/* Opcode: SeekGE P1 P2 P3 P4 *
** Synopsis: key=r[P3@P4]

  i64 iKey;          /* The rowid we are to seek to */
  int eqOnly;        /* Only interested in == results */

  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  assert( pOp->p2!=0 );
  pC = p->apCsr[pOp->p1];
  assert( pC!=0 );
  assert( pC->eCurType==CURTYPE_BTREE );
  assert( OP_SeekLE == OP_SeekLT+1 );
  assert( OP_SeekGE == OP_SeekLT+2 );
  assert( OP_SeekGT == OP_SeekLT+3 );
  assert( pC->isOrdered );
  assert( pC->uc.pCursor!=0 );
  oc = pOp->opcode;
  eqOnly = 0;
  pC->nullRow = 0;
#ifdef SQLITE_DEBUG
  pC->seekOp = pOp->opcode;
#endif

  if( pC->isTable ){
    /* The BTREE_SEEK_EQ flag is only set on index cursors */
    assert( sqlite3BtreeCursorHasHint(pC->uc.pCursor, BTREE_SEEK_EQ)==0 );

    /* The input value in P3 might be of any type: integer, real, string,
    ** blob, or NULL.  But it needs to be an integer before we can do
    ** the seek, so convert it. */
    pIn3 = &aMem[pOp->p3];
    if( (pIn3->flags & (MEM_Int|MEM_Real|MEM_Str))==MEM_Str ){
      applyNumericAffinity(pIn3, 0);

      else if( pIn3->u.r>(double)iKey ){
        assert( OP_SeekLE==(OP_SeekLT+1) );
        assert( OP_SeekGT==(OP_SeekGE+1) );
        assert( (OP_SeekLT & 0x0001)==(OP_SeekGE & 0x0001) );
        if( (oc & 0x0001)==(OP_SeekLT & 0x0001) ) oc++;
      }
    } 
    rc = sqlite3BtreeMovetoUnpacked(pC->uc.pCursor, 0, (u64)iKey, 0, &res);
    pC->movetoTarget = iKey;  /* Used by OP_Delete */
    if( rc!=SQLITE_OK ){
      goto abort_due_to_error;
    }
  }else{
    /* For a cursor with the BTREE_SEEK_EQ hint, only the OP_SeekGE and
    ** OP_SeekLE opcodes are allowed, and these must be immediately followed
    ** by an OP_IdxGT or OP_IdxLT opcode, respectively, with the same key.
    */
    if( sqlite3BtreeCursorHasHint(pC->uc.pCursor, BTREE_SEEK_EQ) ){
      eqOnly = 1;
      assert( pOp->opcode==OP_SeekGE || pOp->opcode==OP_SeekLE );
      assert( pOp[1].opcode==OP_IdxLT || pOp[1].opcode==OP_IdxGT );
      assert( pOp[1].p1==pOp[0].p1 );
      assert( pOp[1].p2==pOp[0].p2 );
      assert( pOp[1].p3==pOp[0].p3 );
      assert( pOp[1].p4.i==pOp[0].p4.i );

    r.aMem = &aMem[pOp->p3];
#ifdef SQLITE_DEBUG
    { int i; for(i=0; i<r.nField; i++) assert( memIsValid(&r.aMem[i]) ); }
#endif
    ExpandBlob(r.aMem);
    r.eqSeen = 0;
    rc = sqlite3BtreeMovetoUnpacked(pC->uc.pCursor, &r, 0, 0, &res);
    if( rc!=SQLITE_OK ){
      goto abort_due_to_error;
    }
    if( eqOnly && r.eqSeen==0 ){
      assert( res!=0 );
      goto seek_not_found;
    }
  }
  pC->deferredMoveto = 0;
  pC->cacheStatus = CACHE_STALE;
#ifdef SQLITE_TEST
  sqlite3_search_count++;
#endif
  if( oc>=OP_SeekGE ){  assert( oc==OP_SeekGE || oc==OP_SeekGT );
    if( res<0 || (res==0 && oc==OP_SeekGT) ){
      res = 0;
      rc = sqlite3BtreeNext(pC->uc.pCursor, &res);
      if( rc!=SQLITE_OK ) goto abort_due_to_error;
    }else{
      res = 0;
    }
  }else{
    assert( oc==OP_SeekLT || oc==OP_SeekLE );
    if( res>0 || (res==0 && oc==OP_SeekLT) ){
      res = 0;
      rc = sqlite3BtreePrevious(pC->uc.pCursor, &res);
      if( rc!=SQLITE_OK ) goto abort_due_to_error;
    }else{
      /* res might be negative because the table is empty.  Check to
      ** see if this is the case.
      */
      res = sqlite3BtreeEof(pC->uc.pCursor);
    }
  }
seek_not_found:
  assert( pOp->p2>0 );
  VdbeBranchTaken(res!=0,2);
  if( res ){
    goto jump_to_p2;

*/
case OP_Seek: {    /* in2 */
  VdbeCursor *pC;

  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  pC = p->apCsr[pOp->p1];
  assert( pC!=0 );
  assert( pC->eCurType==CURTYPE_BTREE );
  assert( pC->uc.pCursor!=0 );
  assert( pC->isTable );
  pC->nullRow = 0;
  pIn2 = &aMem[pOp->p2];
  pC->movetoTarget = sqlite3VdbeIntValue(pIn2);
  pC->deferredMoveto = 1;
  break;
}

  assert( pOp->p4type==P4_INT32 );
  pC = p->apCsr[pOp->p1];
  assert( pC!=0 );
#ifdef SQLITE_DEBUG
  pC->seekOp = pOp->opcode;
#endif
  pIn3 = &aMem[pOp->p3];
  assert( pC->eCurType==CURTYPE_BTREE );
  assert( pC->uc.pCursor!=0 );
  assert( pC->isTable==0 );
  pFree = 0;
  if( pOp->p4.i>0 ){
    r.pKeyInfo = pC->pKeyInfo;
    r.nField = (u16)pOp->p4.i;
    r.aMem = pIn3;
    for(ii=0; ii<r.nField; ii++){

    for(ii=0; ii<pIdxKey->nField; ii++){
      if( pIdxKey->aMem[ii].flags & MEM_Null ){
        takeJump = 1;
        break;
      }
    }
  }
  rc = sqlite3BtreeMovetoUnpacked(pC->uc.pCursor, pIdxKey, 0, 0, &res);
  sqlite3DbFree(db, pFree);
  if( rc!=SQLITE_OK ){
    break;
  }
  pC->seekResult = res;
  alreadyExists = (res==0);
  pC->nullRow = 1-alreadyExists;

  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  pC = p->apCsr[pOp->p1];
  assert( pC!=0 );
#ifdef SQLITE_DEBUG
  pC->seekOp = 0;
#endif
  assert( pC->isTable );
  assert( pC->eCurType==CURTYPE_BTREE );
  pCrsr = pC->uc.pCursor;
  assert( pCrsr!=0 );
  res = 0;
  iKey = pIn3->u.i;
  rc = sqlite3BtreeMovetoUnpacked(pCrsr, 0, iKey, 0, &res);
  assert( rc==SQLITE_OK || res==0 );
  pC->movetoTarget = iKey;  /* Used by OP_Delete */
  pC->nullRow = 0;

** Write the sequence number into register P2.
** The sequence number on the cursor is incremented after this
** instruction.  
*/
case OP_Sequence: {           /* out2 */
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  assert( p->apCsr[pOp->p1]!=0 );
  assert( p->apCsr[pOp->p1]->eCurType!=CURTYPE_VTAB );
  pOut = out2Prerelease(p, pOp);
  pOut->u.i = p->apCsr[pOp->p1]->seqCount++;
  break;
}


/* Opcode: NewRowid P1 P2 P3 * *

  v = 0;
  res = 0;
  pOut = out2Prerelease(p, pOp);
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  pC = p->apCsr[pOp->p1];
  assert( pC!=0 );
  assert( pC->eCurType==CURTYPE_BTREE );
  assert( pC->uc.pCursor!=0 );
  {
    /* The next rowid or record number (different terms for the same
    ** thing) is obtained in a two-step algorithm.
    **
    ** First we attempt to find the largest existing rowid and add one
    ** to that.  But if the largest existing rowid is already the maximum
    ** positive integer, we have to fall through to the second

    ** Others complain about 0x7ffffffffffffffffLL.  The following macro seems
    ** to provide the constant while making all compilers happy.
    */
#   define MAX_ROWID  (i64)( (((u64)0x7fffffff)<<32) | (u64)0xffffffff )
#endif

    if( !pC->useRandomRowid ){
      rc = sqlite3BtreeLast(pC->uc.pCursor, &res);
      if( rc!=SQLITE_OK ){
        goto abort_due_to_error;
      }
      if( res ){
        v = 1;   /* IMP: R-61914-48074 */
      }else{
        assert( sqlite3BtreeCursorIsValid(pC->uc.pCursor) );
        rc = sqlite3BtreeKeySize(pC->uc.pCursor, &v);
        assert( rc==SQLITE_OK );   /* Cannot fail following BtreeLast() */
        if( v>=MAX_ROWID ){
          pC->useRandomRowid = 1;
        }else{
          v++;   /* IMP: R-29538-34987 */
        }
      }

      ** it finds one that is not previously used. */
      assert( pOp->p3==0 );  /* We cannot be in random rowid mode if this is
                             ** an AUTOINCREMENT table. */
      cnt = 0;
      do{
        sqlite3_randomness(sizeof(v), &v);
        v &= (MAX_ROWID>>1); v++;  /* Ensure that v is greater than zero */
      }while(  ((rc = sqlite3BtreeMovetoUnpacked(pC->uc.pCursor, 0, (u64)v,
                                                 0, &res))==SQLITE_OK)
            && (res==0)
            && (++cnt<100));
      if( rc==SQLITE_OK && res==0 ){
        rc = SQLITE_FULL;   /* IMP: R-38219-53002 */
        goto abort_due_to_error;
      }

  int op;           /* Opcode for update hook: SQLITE_UPDATE or SQLITE_INSERT */

  pData = &aMem[pOp->p2];
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  assert( memIsValid(pData) );
  pC = p->apCsr[pOp->p1];
  assert( pC!=0 );
  assert( pC->eCurType==CURTYPE_BTREE );
  assert( pC->uc.pCursor!=0 );
  assert( pC->isTable );
  REGISTER_TRACE(pOp->p2, pData);

  if( pOp->opcode==OP_Insert ){
    pKey = &aMem[pOp->p3];
    assert( pKey->flags & MEM_Int );
    assert( memIsValid(pKey) );

  }
  seekResult = ((pOp->p5 & OPFLAG_USESEEKRESULT) ? pC->seekResult : 0);
  if( pData->flags & MEM_Zero ){
    nZero = pData->u.nZero;
  }else{
    nZero = 0;
  }
  rc = sqlite3BtreeInsert(pC->uc.pCursor, 0, iKey,
                          pData->z, pData->n, nZero,
                          (pOp->p5 & OPFLAG_APPEND)!=0, seekResult
  );
  pC->deferredMoveto = 0;
  pC->cacheStatus = CACHE_STALE;

  /* Invoke the update-hook if required. */

case OP_Delete: {
  VdbeCursor *pC;
  u8 hasUpdateCallback;

  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  pC = p->apCsr[pOp->p1];
  assert( pC!=0 );
  assert( pC->eCurType==CURTYPE_BTREE );
  assert( pC->uc.pCursor!=0 );
  assert( pC->deferredMoveto==0 );

  hasUpdateCallback = db->xUpdateCallback && pOp->p4.z && pC->isTable;
  if( pOp->p5 && hasUpdateCallback ){
    sqlite3BtreeKeySize(pC->uc.pCursor, &pC->movetoTarget);
  }

#ifdef SQLITE_DEBUG
  /* The seek operation that positioned the cursor prior to OP_Delete will
  ** have also set the pC->movetoTarget field to the rowid of the row that
  ** is being deleted */
  if( pOp->p4.z && pC->isTable && pOp->p5==0 ){
    i64 iKey = 0;
    sqlite3BtreeKeySize(pC->uc.pCursor, &iKey);
    assert( pC->movetoTarget==iKey ); 
  }
#endif
 
  rc = sqlite3BtreeDelete(pC->uc.pCursor, pOp->p5);
  pC->cacheStatus = CACHE_STALE;

  /* Invoke the update-hook if required. */
  if( rc==SQLITE_OK && hasUpdateCallback ){
    db->xUpdateCallback(db->pUpdateArg, SQLITE_DELETE,
                        db->aDb[pC->iDb].zName, pOp->p4.z, pC->movetoTarget);
    assert( pC->iDb>=0 );

  pOut = &aMem[pOp->p2];
  memAboutToChange(p, pOut);

  /* Note that RowKey and RowData are really exactly the same instruction */
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  pC = p->apCsr[pOp->p1];
  assert( pC!=0 );
  assert( pC->eCurType==CURTYPE_BTREE );
  assert( isSorter(pC)==0 );
  assert( pC->isTable || pOp->opcode!=OP_RowData );
  assert( pC->isTable==0 || pOp->opcode==OP_RowData );

  assert( pC->nullRow==0 );

  assert( pC->uc.pCursor!=0 );
  pCrsr = pC->uc.pCursor;

  /* The OP_RowKey and OP_RowData opcodes always follow OP_NotExists or
  ** OP_Rewind/Op_Next with no intervening instructions that might invalidate
  ** the cursor.  If this where not the case, on of the following assert()s
  ** would fail.  Should this ever change (because of changes in the code
  ** generator) then the fix would be to insert a call to
  ** sqlite3VdbeCursorMoveto().

  sqlite3_vtab *pVtab;
  const sqlite3_module *pModule;

  pOut = out2Prerelease(p, pOp);
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  pC = p->apCsr[pOp->p1];
  assert( pC!=0 );
  assert( pC->eCurType!=CURTYPE_PSEUDO || pC->nullRow );
  if( pC->nullRow ){
    pOut->flags = MEM_Null;
    break;
  }else if( pC->deferredMoveto ){
    v = pC->movetoTarget;
#ifndef SQLITE_OMIT_VIRTUALTABLE
  }else if( pC->eCurType==CURTYPE_VTAB ){
    assert( pC->uc.pVCur!=0 );
    pVtab = pC->uc.pVCur->pVtab;
    pModule = pVtab->pModule;
    assert( pModule->xRowid );
    rc = pModule->xRowid(pC->uc.pVCur, &v);
    sqlite3VtabImportErrmsg(p, pVtab);
#endif /* SQLITE_OMIT_VIRTUALTABLE */
  }else{
    assert( pC->eCurType==CURTYPE_BTREE );
    assert( pC->uc.pCursor!=0 );
    rc = sqlite3VdbeCursorRestore(pC);
    if( rc ) goto abort_due_to_error;
    if( pC->nullRow ){
      pOut->flags = MEM_Null;
      break;
    }
    rc = sqlite3BtreeKeySize(pC->uc.pCursor, &v);
    assert( rc==SQLITE_OK );  /* Always so because of CursorRestore() above */
  }
  pOut->u.i = v;
  break;
}

/* Opcode: NullRow P1 * * * *
**
** Move the cursor P1 to a null row.  Any OP_Column operations
** that occur while the cursor is on the null row will always
** write a NULL.
*/
case OP_NullRow: {
  VdbeCursor *pC;

  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  pC = p->apCsr[pOp->p1];
  assert( pC!=0 );
  pC->nullRow = 1;
  pC->cacheStatus = CACHE_STALE;
  if( pC->eCurType==CURTYPE_BTREE ){
    assert( pC->uc.pCursor!=0 );
    sqlite3BtreeClearCursor(pC->uc.pCursor);
  }
  break;
}

/* Opcode: Last P1 P2 P3 * *
**
** The next use of the Rowid or Column or Prev instruction for P1 

  VdbeCursor *pC;
  BtCursor *pCrsr;
  int res;

  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  pC = p->apCsr[pOp->p1];
  assert( pC!=0 );
  assert( pC->eCurType==CURTYPE_BTREE );
  pCrsr = pC->uc.pCursor;
  res = 0;
  assert( pCrsr!=0 );
  rc = sqlite3BtreeLast(pCrsr, &res);
  pC->nullRow = (u8)res;
  pC->deferredMoveto = 0;
  pC->cacheStatus = CACHE_STALE;
  pC->seekResult = pOp->p3;

  res = 1;
#ifdef SQLITE_DEBUG
  pC->seekOp = OP_Rewind;
#endif
  if( isSorter(pC) ){
    rc = sqlite3VdbeSorterRewind(pC, &res);
  }else{
    assert( pC->eCurType==CURTYPE_BTREE );
    pCrsr = pC->uc.pCursor;
    assert( pCrsr );
    rc = sqlite3BtreeFirst(pCrsr, &res);
    pC->deferredMoveto = 0;
    pC->cacheStatus = CACHE_STALE;
  }
  pC->nullRow = (u8)res;
  assert( pOp->p2>0 && pOp->p2<p->nOp );

case OP_Next:          /* jump */
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  assert( pOp->p5<ArraySize(p->aCounter) );
  pC = p->apCsr[pOp->p1];
  res = pOp->p3;
  assert( pC!=0 );
  assert( pC->deferredMoveto==0 );
  assert( pC->eCurType==CURTYPE_BTREE );
  assert( res==0 || (res==1 && pC->isTable==0) );
  testcase( res==1 );
  assert( pOp->opcode!=OP_Next || pOp->p4.xAdvance==sqlite3BtreeNext );
  assert( pOp->opcode!=OP_Prev || pOp->p4.xAdvance==sqlite3BtreePrevious );
  assert( pOp->opcode!=OP_NextIfOpen || pOp->p4.xAdvance==sqlite3BtreeNext );
  assert( pOp->opcode!=OP_PrevIfOpen || pOp->p4.xAdvance==sqlite3BtreePrevious);

  /* The Next opcode is only used after SeekGT, SeekGE, and Rewind.
  ** The Prev opcode is only used after SeekLT, SeekLE, and Last. */
  assert( pOp->opcode!=OP_Next || pOp->opcode!=OP_NextIfOpen
       || pC->seekOp==OP_SeekGT || pC->seekOp==OP_SeekGE
       || pC->seekOp==OP_Rewind || pC->seekOp==OP_Found);
  assert( pOp->opcode!=OP_Prev || pOp->opcode!=OP_PrevIfOpen
       || pC->seekOp==OP_SeekLT || pC->seekOp==OP_SeekLE
       || pC->seekOp==OP_Last );

  rc = pOp->p4.xAdvance(pC->uc.pCursor, &res);
next_tail:
  pC->cacheStatus = CACHE_STALE;
  VdbeBranchTaken(res==0,2);
  if( res==0 ){
    pC->nullRow = 0;
    p->aCounter[pOp->p5]++;
#ifdef SQLITE_TEST

  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  pC = p->apCsr[pOp->p1];
  assert( pC!=0 );
  assert( isSorter(pC)==(pOp->opcode==OP_SorterInsert) );
  pIn2 = &aMem[pOp->p2];
  assert( pIn2->flags & MEM_Blob );
  if( pOp->p5 & OPFLAG_NCHANGE ) p->nChange++;
  assert( pC->eCurType==CURTYPE_BTREE || pOp->opcode==OP_SorterInsert );
  assert( pC->isTable==0 );
  rc = ExpandBlob(pIn2);
  if( rc==SQLITE_OK ){
    if( pOp->opcode==OP_SorterInsert ){
      rc = sqlite3VdbeSorterWrite(pC, pIn2);
    }else{
      nKey = pIn2->n;
      zKey = pIn2->z;
      rc = sqlite3BtreeInsert(pC->uc.pCursor, zKey, nKey, "", 0, 0, pOp->p3, 
          ((pOp->p5 & OPFLAG_USESEEKRESULT) ? pC->seekResult : 0)
          );
      assert( pC->deferredMoveto==0 );
      pC->cacheStatus = CACHE_STALE;
    }
  }
  break;

  UnpackedRecord r;

  assert( pOp->p3>0 );
  assert( pOp->p2>0 && pOp->p2+pOp->p3<=(p->nMem-p->nCursor)+1 );
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  pC = p->apCsr[pOp->p1];
  assert( pC!=0 );
  assert( pC->eCurType==CURTYPE_BTREE );
  pCrsr = pC->uc.pCursor;
  assert( pCrsr!=0 );
  assert( pOp->p5==0 );
  r.pKeyInfo = pC->pKeyInfo;
  r.nField = (u16)pOp->p3;
  r.default_rc = 0;
  r.aMem = &aMem[pOp->p2];
#ifdef SQLITE_DEBUG

  VdbeCursor *pC;
  i64 rowid;

  pOut = out2Prerelease(p, pOp);
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  pC = p->apCsr[pOp->p1];
  assert( pC!=0 );
  assert( pC->eCurType==CURTYPE_BTREE );
  pCrsr = pC->uc.pCursor;
  assert( pCrsr!=0 );
  pOut->flags = MEM_Null;
  assert( pC->isTable==0 );
  assert( pC->deferredMoveto==0 );

  /* sqlite3VbeCursorRestore() can only fail if the record has been deleted
  ** out from under the cursor.  That will never happend for an IdxRowid

  int res;
  UnpackedRecord r;

  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  pC = p->apCsr[pOp->p1];
  assert( pC!=0 );
  assert( pC->isOrdered );
  assert( pC->eCurType==CURTYPE_BTREE );
  assert( pC->uc.pCursor!=0);
  assert( pC->deferredMoveto==0 );
  assert( pOp->p5==0 || pOp->p5==1 );
  assert( pOp->p4type==P4_INT32 );
  r.pKeyInfo = pC->pKeyInfo;
  r.nField = (u16)pOp->p4.i;
  if( pOp->opcode<OP_IdxLT ){
    assert( pOp->opcode==OP_IdxLE || pOp->opcode==OP_IdxGT );

*/
case OP_ResetSorter: {
  VdbeCursor *pC;
 
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  pC = p->apCsr[pOp->p1];
  assert( pC!=0 );
  if( isSorter(pC) ){
    sqlite3VdbeSorterReset(db, pC->uc.pSorter);
  }else{
    assert( pC->eCurType==CURTYPE_BTREE );
    assert( pC->isEphemeral );
    rc = sqlite3BtreeClearTableOfCursor(pC->uc.pCursor);
  }
  break;
}

/* Opcode: CreateTable P1 P2 * * *
** Synopsis: r[P2]=root iDb=P1
**

**
** P4 is a pointer to a virtual table object, an sqlite3_vtab structure.
** P1 is a cursor number.  This opcode opens a cursor to the virtual
** table and stores that cursor in P1.
*/
case OP_VOpen: {
  VdbeCursor *pCur;
  sqlite3_vtab_cursor *pVCur;
  sqlite3_vtab *pVtab;
  const sqlite3_module *pModule;

  assert( p->bIsReader );
  pCur = 0;
  pVCur = 0;
  pVtab = pOp->p4.pVtab->pVtab;
  if( pVtab==0 || NEVER(pVtab->pModule==0) ){
    rc = SQLITE_LOCKED;
    break;
  }
  pModule = pVtab->pModule;
  rc = pModule->xOpen(pVtab, &pVCur);
  sqlite3VtabImportErrmsg(p, pVtab);
  if( SQLITE_OK==rc ){
    /* Initialize sqlite3_vtab_cursor base class */
    pVCur->pVtab = pVtab;

    /* Initialize vdbe cursor object */
    pCur = allocateCursor(p, pOp->p1, 0, -1, CURTYPE_VTAB);
    if( pCur ){
      pCur->uc.pVCur = pVCur;
      pVtab->nRef++;
    }else{
      assert( db->mallocFailed );
      pModule->xClose(pVCur);
      goto no_mem;
    }
  }
  break;
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */

*/
case OP_VFilter: {   /* jump */
  int nArg;
  int iQuery;
  const sqlite3_module *pModule;
  Mem *pQuery;
  Mem *pArgc;
  sqlite3_vtab_cursor *pVCur;
  sqlite3_vtab *pVtab;
  VdbeCursor *pCur;
  int res;
  int i;
  Mem **apArg;

  pQuery = &aMem[pOp->p3];
  pArgc = &pQuery[1];
  pCur = p->apCsr[pOp->p1];
  assert( memIsValid(pQuery) );
  REGISTER_TRACE(pOp->p3, pQuery);
  assert( pCur->eCurType==CURTYPE_VTAB );
  pVCur = pCur->uc.pVCur;
  pVtab = pVCur->pVtab;
  pModule = pVtab->pModule;

  /* Grab the index number and argc parameters */
  assert( (pQuery->flags&MEM_Int)!=0 && pArgc->flags==MEM_Int );
  nArg = (int)pArgc->u.i;
  iQuery = (int)pQuery->u.i;

  /* Invoke the xFilter method */
  res = 0;
  apArg = p->apArg;
  for(i = 0; i<nArg; i++){
    apArg[i] = &pArgc[i+1];
  }
  rc = pModule->xFilter(pVCur, iQuery, pOp->p4.z, nArg, apArg);
  sqlite3VtabImportErrmsg(p, pVtab);
  if( rc==SQLITE_OK ){
    res = pModule->xEof(pVCur);
  }
  pCur->nullRow = 0;
  VdbeBranchTaken(res!=0,2);
  if( res ) goto jump_to_p2;
  break;
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */

case OP_VColumn: {
  sqlite3_vtab *pVtab;
  const sqlite3_module *pModule;
  Mem *pDest;
  sqlite3_context sContext;

  VdbeCursor *pCur = p->apCsr[pOp->p1];
  assert( pCur->eCurType==CURTYPE_VTAB );
  assert( pOp->p3>0 && pOp->p3<=(p->nMem-p->nCursor) );
  pDest = &aMem[pOp->p3];
  memAboutToChange(p, pDest);
  if( pCur->nullRow ){
    sqlite3VdbeMemSetNull(pDest);
    break;
  }
  pVtab = pCur->uc.pVCur->pVtab;
  pModule = pVtab->pModule;
  assert( pModule->xColumn );
  memset(&sContext, 0, sizeof(sContext));
  sContext.pOut = pDest;
  MemSetTypeFlag(pDest, MEM_Null);
  rc = pModule->xColumn(pCur->uc.pVCur, &sContext, pOp->p2);
  sqlite3VtabImportErrmsg(p, pVtab);
  if( sContext.isError ){
    rc = sContext.isError;
  }
  sqlite3VdbeChangeEncoding(pDest, encoding);
  REGISTER_TRACE(pOp->p3, pDest);
  UPDATE_MAX_BLOBSIZE(pDest);

  sqlite3_vtab *pVtab;
  const sqlite3_module *pModule;
  int res;
  VdbeCursor *pCur;

  res = 0;
  pCur = p->apCsr[pOp->p1];
  assert( pCur->eCurType==CURTYPE_VTAB );
  if( pCur->nullRow ){
    break;
  }
  pVtab = pCur->uc.pVCur->pVtab;
  pModule = pVtab->pModule;
  assert( pModule->xNext );

  /* Invoke the xNext() method of the module. There is no way for the
  ** underlying implementation to return an error if one occurs during
  ** xNext(). Instead, if an error occurs, true is returned (indicating that 
  ** data is available) and the error code returned when xColumn or
  ** some other method is next invoked on the save virtual table cursor.
  */
  rc = pModule->xNext(pCur->uc.pVCur);
  sqlite3VtabImportErrmsg(p, pVtab);
  if( rc==SQLITE_OK ){
    res = pModule->xEof(pCur->uc.pVCur);
  }
  VdbeBranchTaken(!res,2);
  if( !res ){
    /* If there is data, jump to P2 */
    goto jump_to_p2_and_check_for_interrupt;
  }
  goto check_for_interrupt;

case OP_CursorHint: {
  VdbeCursor *pC;

  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  assert( pOp->p4type==P4_EXPR );
  pC = p->apCsr[pOp->p1];
  if( pC ){
    assert( pC->eCurType==CURTYPE_BTREE );
    sqlite3BtreeCursorHint(pC->uc.pCursor, BTREE_HINT_RANGE,
                           pOp->p4.pExpr, aMem);
  }
  break;
}
#endif /* SQLITE_ENABLE_CURSOR_HINTS */

/* Opcode: Noop * * * * *
**

/* Opaque type used by the explainer */
typedef struct Explain Explain;

/* Elements of the linked list at Vdbe.pAuxData */
typedef struct AuxData AuxData;

/* Types of VDBE cursors */
#define CURTYPE_BTREE       0
#define CURTYPE_SORTER      1
#define CURTYPE_VTAB        2
#define CURTYPE_PSEUDO      3

/*
** A VdbeCursor is an superclass (a wrapper) for various cursor objects:




**
**      * A b-tree cursor

**          -  In the main database or in an ephemeral database
**          -  On either an index or a table
**      * A sorter
**      * A virtual table

**      * A one-row "pseudotable" stored in a single register
*/
struct VdbeCursor {
  u8 eCurType;          /* One of the CURTYPE_* values above */
  i8 iDb;               /* Index of cursor database in db->aDb[] (or -1) */
  u8 nullRow;           /* True if pointing to a row with no data */

  u8 deferredMoveto;    /* A call to sqlite3BtreeMoveto() is needed */

  u8 isTable;           /* True for rowid tables.  False for indexes */

#ifdef SQLITE_DEBUG
  u8 seekOp;            /* Most recent seek operation on this cursor */
#endif



  Bool isEphemeral:1;   /* True for an ephemeral table */
  Bool useRandomRowid:1;/* Generate new record numbers semi-randomly */

  Bool isOrdered:1;     /* True if the underlying table is BTREE_UNORDERED */
  Pgno pgnoRoot;        /* Root page of the open btree cursor */
  i16 nField;           /* Number of fields in the header */
  u16 nHdrParsed;       /* Number of header fields parsed so far */
  union {
    BtCursor *pCursor;          /* CURTYPE_BTREE.  Btree cursor */
    sqlite3_vtab_cursor *pVCur; /* CURTYPE_VTAB.   Vtab cursor */
    int pseudoTableReg;         /* CURTYPE_PSEUDO. Reg holding content. */
    VdbeSorter *pSorter;        /* CURTYPE_SORTER. Sorter object */
  } uc;
  Btree *pBt;           /* Separate file holding temporary table */
  KeyInfo *pKeyInfo;    /* Info about index keys needed by index cursors */
  int seekResult;       /* Result of previous sqlite3BtreeMoveto() */
  i64 seqCount;         /* Sequence counter */
  i64 movetoTarget;     /* Argument to the deferred sqlite3BtreeMoveto() */

#ifdef SQLITE_ENABLE_COLUMN_USED_MASK
  u64 maskUsed;         /* Mask of columns used by this cursor */
#endif

  /* Cached information about the header for the data record that the
  ** cursor is currently pointing to.  Only valid if cacheStatus matches
  ** Vdbe.cacheCtr.  Vdbe.cacheCtr will never take on the value of

void sqlite3VdbeChangeToNoop(Vdbe *p, int addr){
  if( addr<p->nOp ){
    VdbeOp *pOp = &p->aOp[addr];
    sqlite3 *db = p->db;
    freeP4(db, pOp->p4type, pOp->p4.p);
    memset(pOp, 0, sizeof(pOp[0]));
    pOp->opcode = OP_Noop;

  }
}

/*
** If the last opcode is "op" and it is not a jump destination,
** then remove it.  Return true if and only if an opcode was removed.
*/

** Close a VDBE cursor and release all the resources that cursor 
** happens to hold.
*/
void sqlite3VdbeFreeCursor(Vdbe *p, VdbeCursor *pCx){
  if( pCx==0 ){
    return;
  }
  assert( pCx->pBt==0 || pCx->eCurType==CURTYPE_BTREE );
  switch( pCx->eCurType ){
    case CURTYPE_SORTER: {
      sqlite3VdbeSorterClose(p->db, pCx);
      break;
    }
    case CURTYPE_BTREE: {
      if( pCx->pBt ){
        sqlite3BtreeClose(pCx->pBt);
        /* The pCx->pCursor will be close automatically, if it exists, by
        ** the call above. */
      }else{
        assert( pCx->uc.pCursor!=0 );
        sqlite3BtreeCloseCursor(pCx->uc.pCursor);
      }
      break;
    }
#ifndef SQLITE_OMIT_VIRTUALTABLE
    case CURTYPE_VTAB: {
      sqlite3_vtab_cursor *pVCur = pCx->uc.pVCur;
      const sqlite3_module *pModule = pVCur->pVtab->pModule;
      assert( pVCur->pVtab->nRef>0 );
      pVCur->pVtab->nRef--;
      pModule->xClose(pVCur);
      break;
    }
#endif
  }
}

/*
** Close all cursors in the current frame.
*/
static void closeCursorsInFrame(Vdbe *p){
  if( p->apCsr ){

static int SQLITE_NOINLINE handleDeferredMoveto(VdbeCursor *p){
  int res, rc;
#ifdef SQLITE_TEST
  extern int sqlite3_search_count;
#endif
  assert( p->deferredMoveto );
  assert( p->isTable );
  assert( p->eCurType==CURTYPE_BTREE );
  rc = sqlite3BtreeMovetoUnpacked(p->uc.pCursor, 0, p->movetoTarget, 0, &res);
  if( rc ) return rc;
  if( res!=0 ) return SQLITE_CORRUPT_BKPT;
#ifdef SQLITE_TEST
  sqlite3_search_count++;
#endif
  p->deferredMoveto = 0;
  p->cacheStatus = CACHE_STALE;
  return SQLITE_OK;
}

/*
** Something has moved cursor "p" out of place.  Maybe the row it was
** pointed to was deleted out from under it.  Or maybe the btree was
** rebalanced.  Whatever the cause, try to restore "p" to the place it
** is supposed to be pointing.  If the row was deleted out from under the
** cursor, set the cursor to point to a NULL row.
*/
static int SQLITE_NOINLINE handleMovedCursor(VdbeCursor *p){
  int isDifferentRow, rc;
  assert( p->eCurType==CURTYPE_BTREE );
  assert( p->uc.pCursor!=0 );
  assert( sqlite3BtreeCursorHasMoved(p->uc.pCursor) );
  rc = sqlite3BtreeCursorRestore(p->uc.pCursor, &isDifferentRow);
  p->cacheStatus = CACHE_STALE;
  if( isDifferentRow ) p->nullRow = 1;
  return rc;
}

/*
** Check to ensure that the cursor is valid.  Restore the cursor
** if need be.  Return any I/O error from the restore operation.
*/
int sqlite3VdbeCursorRestore(VdbeCursor *p){
  assert( p->eCurType==CURTYPE_BTREE );
  if( sqlite3BtreeCursorHasMoved(p->uc.pCursor) ){
    return handleMovedCursor(p);
  }
  return SQLITE_OK;
}

/*
** Make sure the cursor p is ready to read or write the row to which it
** was last positioned.  Return an error code if an OOM fault or I/O error
** prevents us from positioning the cursor to its correct position.
**
** If a MoveTo operation is pending on the given cursor, then do that
** MoveTo now.  If no move is pending, check to see if the row has been
** deleted out from under the cursor and if it has, mark the row as
** a NULL row.
**
** If the cursor is already pointing to the correct row and that row has
** not been deleted out from under the cursor, then this routine is a no-op.
*/
int sqlite3VdbeCursorMoveto(VdbeCursor *p){
  if( p->eCurType==CURTYPE_BTREE ){
    if( p->deferredMoveto ){
      return handleDeferredMoveto(p);
    }
    if( sqlite3BtreeCursorHasMoved(p->uc.pCursor) ){
      return handleMovedCursor(p);
    }
  }
  return SQLITE_OK;
}

/*
** The following functions:
**

  sqlite3 *db,                     /* Database connection */
  VdbeCursor *pC,                  /* The cursor to compare against */
  UnpackedRecord *pUnpacked,       /* Unpacked version of key */
  int *res                         /* Write the comparison result here */
){
  i64 nCellKey = 0;
  int rc;
  BtCursor *pCur;
  Mem m;

  assert( pC->eCurType==CURTYPE_BTREE );
  pCur = pC->uc.pCursor;
  assert( sqlite3BtreeCursorIsValid(pCur) );
  VVA_ONLY(rc =) sqlite3BtreeKeySize(pCur, &nCellKey);
  assert( rc==SQLITE_OK );    /* pCur is always valid so KeySize cannot fail */
  /* nCellKey will always be between 0 and 0xffffffff because of the way
  ** that btreeParseCellPtr() and sqlite3GetVarint32() are implemented */
  if( nCellKey<=0 || nCellKey>0x7fffffff ){
    *res = 0;
    return SQLITE_CORRUPT_BKPT;
  }
  sqlite3VdbeMemInit(&m, db, 0);
  rc = sqlite3VdbeMemFromBtree(pCur, 0, (u32)nCellKey, 1, &m);
  if( rc ){
    return rc;
  }
  *res = sqlite3VdbeRecordCompare(m.n, m.z, pUnpacked);
  sqlite3VdbeMemRelease(&m);
  return SQLITE_OK;
}

      );
      rc = SQLITE_ERROR;
      sqlite3_finalize(p->pStmt);
      p->pStmt = 0;
    }else{
      p->iOffset = pC->aType[p->iCol + pC->nField];
      p->nByte = sqlite3VdbeSerialTypeLen(type);
      p->pCsr =  pC->uc.pCursor;
      sqlite3BtreeIncrblobCursor(p->pCsr);
    }
  }

  if( rc==SQLITE_ROW ){
    rc = SQLITE_OK;
  }else if( p->pStmt ){

#if SQLITE_MAX_WORKER_THREADS>=SORTER_MAX_MERGE_COUNT
  if( nWorker>=SORTER_MAX_MERGE_COUNT ){
    nWorker = SORTER_MAX_MERGE_COUNT-1;
  }
#endif

  assert( pCsr->pKeyInfo && pCsr->pBt==0 );
  assert( pCsr->eCurType==CURTYPE_SORTER );
  szKeyInfo = sizeof(KeyInfo) + (pCsr->pKeyInfo->nField-1)*sizeof(CollSeq*);
  sz = sizeof(VdbeSorter) + nWorker * sizeof(SortSubtask);

  pSorter = (VdbeSorter*)sqlite3DbMallocZero(db, sz + szKeyInfo);
  pCsr->uc.pSorter = pSorter;
  if( pSorter==0 ){
    rc = SQLITE_NOMEM;
  }else{
    pSorter->pKeyInfo = pKeyInfo = (KeyInfo*)((u8*)pSorter + sz);
    memcpy(pKeyInfo, pCsr->pKeyInfo, szKeyInfo);
    pKeyInfo->db = 0;
    if( nField && nWorker==0 ){

  pSorter->pUnpacked = 0;
}

/*
** Free any cursor components allocated by sqlite3VdbeSorterXXX routines.
*/
void sqlite3VdbeSorterClose(sqlite3 *db, VdbeCursor *pCsr){
  VdbeSorter *pSorter;
  assert( pCsr->eCurType==CURTYPE_SORTER );
  pSorter = pCsr->uc.pSorter;
  if( pSorter ){
    sqlite3VdbeSorterReset(db, pSorter);
    sqlite3_free(pSorter->list.aMemory);
    sqlite3DbFree(db, pSorter);
    pCsr->uc.pSorter = 0;
  }
}

#if SQLITE_MAX_MMAP_SIZE>0
/*
** The first argument is a file-handle open on a temporary file. The file
** is guaranteed to be nByte bytes or smaller in size. This function

/*
** Add a record to the sorter.
*/
int sqlite3VdbeSorterWrite(
  const VdbeCursor *pCsr,         /* Sorter cursor */
  Mem *pVal                       /* Memory cell containing record */
){
  VdbeSorter *pSorter;
  int rc = SQLITE_OK;             /* Return Code */
  SorterRecord *pNew;             /* New list element */

  int bFlush;                     /* True to flush contents of memory to PMA */
  int nReq;                       /* Bytes of memory required */
  int nPMA;                       /* Bytes of PMA space required */
  int t;                          /* serial type of first record field */

  assert( pCsr->eCurType==CURTYPE_SORTER );
  pSorter = pCsr->uc.pSorter;
  getVarint32((const u8*)&pVal->z[1], t);
  if( t>0 && t<10 && t!=7 ){
    pSorter->typeMask &= SORTER_TYPE_INTEGER;
  }else if( t>10 && (t & 0x01) ){
    pSorter->typeMask &= SORTER_TYPE_TEXT;
  }else{
    pSorter->typeMask = 0;

/*
** Once the sorter has been populated by calls to sqlite3VdbeSorterWrite,
** this function is called to prepare for iterating through the records
** in sorted order.
*/
int sqlite3VdbeSorterRewind(const VdbeCursor *pCsr, int *pbEof){
  VdbeSorter *pSorter;
  int rc = SQLITE_OK;             /* Return code */

  assert( pCsr->eCurType==CURTYPE_SORTER );
  pSorter = pCsr->uc.pSorter;
  assert( pSorter );

  /* If no data has been written to disk, then do not do so now. Instead,
  ** sort the VdbeSorter.pRecord list. The vdbe layer will read data directly
  ** from the in-memory list.  */
  if( pSorter->bUsePMA==0 ){
    if( pSorter->list.pList ){

  return rc;
}

/*
** Advance to the next element in the sorter.
*/
int sqlite3VdbeSorterNext(sqlite3 *db, const VdbeCursor *pCsr, int *pbEof){
  VdbeSorter *pSorter;
  int rc;                         /* Return code */

  assert( pCsr->eCurType==CURTYPE_SORTER );
  pSorter = pCsr->uc.pSorter;
  assert( pSorter->bUsePMA || (pSorter->pReader==0 && pSorter->pMerger==0) );
  if( pSorter->bUsePMA ){
    assert( pSorter->pReader==0 || pSorter->pMerger==0 );
    assert( pSorter->bUseThreads==0 || pSorter->pReader );
    assert( pSorter->bUseThreads==1 || pSorter->pMerger );
#if SQLITE_MAX_WORKER_THREADS>0
    if( pSorter->bUseThreads ){

  return pKey;
}

/*
** Copy the current sorter key into the memory cell pOut.
*/
int sqlite3VdbeSorterRowkey(const VdbeCursor *pCsr, Mem *pOut){
  VdbeSorter *pSorter;
  void *pKey; int nKey;           /* Sorter key to copy into pOut */

  assert( pCsr->eCurType==CURTYPE_SORTER );
  pSorter = pCsr->uc.pSorter;
  pKey = vdbeSorterRowkey(pSorter, &nKey);
  if( sqlite3VdbeMemClearAndResize(pOut, nKey) ){
    return SQLITE_NOMEM;
  }
  pOut->n = nKey;
  MemSetTypeFlag(pOut, MEM_Blob);
  memcpy(pOut->z, pKey, nKey);

*/
int sqlite3VdbeSorterCompare(
  const VdbeCursor *pCsr,         /* Sorter cursor */
  Mem *pVal,                      /* Value to compare to current sorter key */
  int nKeyCol,                    /* Compare this many columns */
  int *pRes                       /* OUT: Result of comparison */
){
  VdbeSorter *pSorter;
  UnpackedRecord *r2;
  KeyInfo *pKeyInfo;
  int i;
  void *pKey; int nKey;           /* Sorter key to compare pVal with */

  assert( pCsr->eCurType==CURTYPE_SORTER );
  pSorter = pCsr->uc.pSorter;
  r2 = pSorter->pUnpacked;
  pKeyInfo = pCsr->pKeyInfo;
  if( r2==0 ){
    char *p;
    r2 = pSorter->pUnpacked = sqlite3VdbeAllocUnpackedRecord(pKeyInfo,0,0,&p);
    assert( pSorter->pUnpacked==(UnpackedRecord*)p );
    if( r2==0 ) return SQLITE_NOMEM;
    r2->nField = nKeyCol;
  }

}
static void walUnlockShared(Wal *pWal, int lockIdx){
  if( pWal->exclusiveMode ) return;
  (void)sqlite3OsShmLock(pWal->pDbFd, lockIdx, 1,
                         SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED);
  WALTRACE(("WAL%p: release SHARED-%s\n", pWal, walLockName(lockIdx)));
}
static int walLockExclusive(Wal *pWal, int lockIdx, int n){
  int rc;
  if( pWal->exclusiveMode ) return SQLITE_OK;

  rc = sqlite3OsShmLock(pWal->pDbFd, lockIdx, n,
                        SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE);
  WALTRACE(("WAL%p: acquire EXCLUSIVE-%s cnt=%d %s\n", pWal,
            walLockName(lockIdx), n, rc ? "failed" : "ok"));
  VVA_ONLY( pWal->lockError = (u8)(rc!=SQLITE_OK && rc!=SQLITE_BUSY); )
  return rc;
}

  */
  assert( pWal->ckptLock==1 || pWal->ckptLock==0 );
  assert( WAL_ALL_BUT_WRITE==WAL_WRITE_LOCK+1 );
  assert( WAL_CKPT_LOCK==WAL_ALL_BUT_WRITE );
  assert( pWal->writeLock );
  iLock = WAL_ALL_BUT_WRITE + pWal->ckptLock;
  nLock = SQLITE_SHM_NLOCK - iLock;
  rc = walLockExclusive(pWal, iLock, nLock);
  if( rc ){
    return rc;
  }
  WALTRACE(("WAL%p: recovery begin...\n", pWal));

  memset(&pWal->hdr, 0, sizeof(WalIndexHdr));

  int (*xBusy)(void*),            /* Function to call when busy */
  void *pBusyArg,                 /* Context argument for xBusyHandler */
  int lockIdx,                    /* Offset of first byte to lock */
  int n                           /* Number of bytes to lock */
){
  int rc;
  do {
    rc = walLockExclusive(pWal, lockIdx, n);
  }while( xBusy && rc==SQLITE_BUSY && xBusy(pBusyArg) );
  return rc;
}

/*
** The cache of the wal-index header must be valid to call this function.
** Return the page-size in bytes used by the database.

  assert( badHdr==0 || pWal->writeLock==0 );
  if( badHdr ){
    if( pWal->readOnly & WAL_SHM_RDONLY ){
      if( SQLITE_OK==(rc = walLockShared(pWal, WAL_WRITE_LOCK)) ){
        walUnlockShared(pWal, WAL_WRITE_LOCK);
        rc = SQLITE_READONLY_RECOVERY;
      }
    }else if( SQLITE_OK==(rc = walLockExclusive(pWal, WAL_WRITE_LOCK, 1)) ){
      pWal->writeLock = 1;
      if( SQLITE_OK==(rc = walIndexPage(pWal, 0, &page0)) ){
        badHdr = walIndexTryHdr(pWal, pChanged);
        if( badHdr ){
          /* If the wal-index header is still malformed even while holding
          ** a WRITE lock, it can only mean that the header is corrupted and
          ** needs to be reconstructed.  So run recovery to do exactly that.

  }
  /* There was once an "if" here. The extra "{" is to preserve indentation. */
  {
    if( (pWal->readOnly & WAL_SHM_RDONLY)==0
     && (mxReadMark<pWal->hdr.mxFrame || mxI==0)
    ){
      for(i=1; i<WAL_NREADER; i++){
        rc = walLockExclusive(pWal, WAL_READ_LOCK(i), 1);
        if( rc==SQLITE_OK ){
          mxReadMark = pInfo->aReadMark[i] = pWal->hdr.mxFrame;
          mxI = i;
          walUnlockExclusive(pWal, WAL_READ_LOCK(i), 1);
          break;
        }else if( rc!=SQLITE_BUSY ){
          return rc;

  ** possible. In this case return SQLITE_READONLY. Otherwise, attempt
  ** to grab the WRITER lock. Set Wal.writeLock to true and return
  ** SQLITE_OK if successful, or leave Wal.writeLock clear and return 
  ** an SQLite error code (possibly SQLITE_BUSY) otherwise. */
  if( pWal->readOnly ){
    rc = SQLITE_READONLY;
  }else{
    rc = walLockExclusive(pWal, WAL_WRITE_LOCK, 1);
    if( rc==SQLITE_OK ){
      pWal->writeLock = 1;
    }
  }

  return rc;
}

  if( pWal->readLock==0 ){
    volatile WalCkptInfo *pInfo = walCkptInfo(pWal);
    assert( pInfo->nBackfill==pWal->hdr.mxFrame );
    if( pInfo->nBackfill>0 ){
      u32 salt1;
      sqlite3_randomness(4, &salt1);
      rc = walLockExclusive(pWal, WAL_READ_LOCK(1), WAL_NREADER-1);
      if( rc==SQLITE_OK ){
        /* If all readers are using WAL_READ_LOCK(0) (in other words if no
        ** readers are currently using the WAL), then the transactions
        ** frames will overwrite the start of the existing log. Update the
        ** wal-index header to reflect this.
        **
        ** In theory it would be Ok to update the cache of the header only

  assert( eMode!=SQLITE_CHECKPOINT_PASSIVE || xBusy==0 );

  if( pWal->readOnly ) return SQLITE_READONLY;
  WALTRACE(("WAL%p: checkpoint begins\n", pWal));

  /* IMPLEMENTATION-OF: R-62028-47212 All calls obtain an exclusive 
  ** "checkpoint" lock on the database file. */
  rc = walLockExclusive(pWal, WAL_CKPT_LOCK, 1);
  if( rc ){
    /* EVIDENCE-OF: R-10421-19736 If any other process is running a
    ** checkpoint operation at the same time, the lock cannot be obtained and
    ** SQLITE_BUSY is returned.
    ** EVIDENCE-OF: R-53820-33897 Even if there is a busy-handler configured,
    ** it will not be invoked in this case.
    */

    if( (pTerm->eOperator & ~(WO_ISNULL|WO_EQUIV|WO_IS))==0 ) continue;
    if( pTerm->wtFlags & TERM_VNULL ) continue;
    assert( pTerm->u.leftColumn>=(-1) );
    pIdxCons[j].iColumn = pTerm->u.leftColumn;
    pIdxCons[j].iTermOffset = i;
    op = (u8)pTerm->eOperator & WO_ALL;
    if( op==WO_IN ) op = WO_EQ;
    if( op==WO_MATCH ){
      op = pTerm->eMatchOp;
    }
    pIdxCons[j].op = op;
    /* The direct assignment in the previous line is possible only because
    ** the WO_ and SQLITE_INDEX_CONSTRAINT_ codes are identical.  The
    ** following asserts verify this fact. */
    assert( WO_EQ==SQLITE_INDEX_CONSTRAINT_EQ );
    assert( WO_LT==SQLITE_INDEX_CONSTRAINT_LT );
    assert( WO_LE==SQLITE_INDEX_CONSTRAINT_LE );

    pIdxInfo->idxStr = 0;
    pIdxInfo->idxNum = 0;
    pIdxInfo->needToFreeIdxStr = 0;
    pIdxInfo->orderByConsumed = 0;
    pIdxInfo->estimatedCost = SQLITE_BIG_DBL / (double)2;
    pIdxInfo->estimatedRows = 25;
    pIdxInfo->idxFlags = 0;
    pIdxInfo->colUsed = (sqlite3_int64)pSrc->colUsed;
    rc = vtabBestIndex(pParse, pTab, pIdxInfo);
    if( rc ) goto whereLoopAddVtab_exit;
    pIdxCons = *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint;
    pNew->prereq = mExtra;
    mxTerm = -1;
    assert( pNew->nLSlot>=nConstraint );
    for(i=0; i<nConstraint; i++) pNew->aLTerm[i] = 0;

    sqlite3VdbeResolveLabel(v, pLevel->addrBrk);
    if( pLevel->addrSkip ){
      sqlite3VdbeGoto(v, pLevel->addrSkip);
      VdbeComment((v, "next skip-scan on %s", pLoop->u.btree.pIndex->zName));
      sqlite3VdbeJumpHere(v, pLevel->addrSkip);
      sqlite3VdbeJumpHere(v, pLevel->addrSkip-2);
    }
#ifndef SQLITE_LIKE_DOESNT_MATCH_BLOBS
    if( pLevel->addrLikeRep ){
      int op;
      if( sqlite3VdbeGetOp(v, pLevel->addrLikeRep-1)->p1 ){
        op = OP_DecrJumpZero;
      }else{
        op = OP_JumpZeroIncr;
      }
      sqlite3VdbeAddOp2(v, op, pLevel->iLikeRepCntr, pLevel->addrLikeRep);
      VdbeCoverage(v);
    }
#endif
    if( pLevel->iLeftJoin ){
      addr = sqlite3VdbeAddOp1(v, OP_IfPos, pLevel->iLeftJoin); VdbeCoverage(v);
      assert( (pLoop->wsFlags & WHERE_IDX_ONLY)==0
           || (pLoop->wsFlags & WHERE_INDEXED)!=0 );
      if( (pLoop->wsFlags & WHERE_IDX_ONLY)==0 ){
        sqlite3VdbeAddOp1(v, OP_NullRow, pTabList->a[i].iCursor);
      }

  int iIdxCur;          /* The VDBE cursor used to access pIdx */
  int addrBrk;          /* Jump here to break out of the loop */
  int addrNxt;          /* Jump here to start the next IN combination */
  int addrSkip;         /* Jump here for next iteration of skip-scan */
  int addrCont;         /* Jump here to continue with the next loop cycle */
  int addrFirst;        /* First instruction of interior of the loop */
  int addrBody;         /* Beginning of the body of this loop */
#ifndef SQLITE_LIKE_DOESNT_MATCH_BLOBS
  int iLikeRepCntr;     /* LIKE range processing counter register */
  int addrLikeRep;      /* LIKE range processing address */
#endif
  u8 iFrom;             /* Which entry in the FROM clause */
  u8 op, p3, p5;        /* Opcode, P3 & P5 of the opcode that ends the loop */
  int p1, p2;           /* Operands of the opcode used to ends the loop */
  union {               /* Information that depends on pWLoop->wsFlags */
    struct {
      int nIn;              /* Number of entries in aInLoop[] */
      struct InLoop {

    WhereOrInfo *pOrInfo;   /* Extra information if (eOperator & WO_OR)!=0 */
    WhereAndInfo *pAndInfo; /* Extra information if (eOperator& WO_AND)!=0 */
  } u;
  LogEst truthProb;       /* Probability of truth for this expression */
  u16 eOperator;          /* A WO_xx value describing <op> */
  u16 wtFlags;            /* TERM_xxx bit flags.  See below */
  u8 nChild;              /* Number of children that must disable us */
  u8 eMatchOp;            /* Op for vtab MATCH/LIKE/GLOB/REGEXP terms */
  WhereClause *pWC;       /* The clause this term is part of */
  Bitmask prereqRight;    /* Bitmask of tables used by pExpr->pRight */
  Bitmask prereqAll;      /* Bitmask of tables referenced by pExpr */
};

/*
** Allowed values of WhereTerm.wtFlags

      }
    }
  }
  *pzAff = zAff;
  return regBase;
}

#ifndef SQLITE_LIKE_DOESNT_MATCH_BLOBS
/*
** If the most recently coded instruction is a constant range contraint
** that originated from the LIKE optimization, then change the P3 to be
** pLoop->iLikeRepCntr and set P5.
**
** The LIKE optimization trys to evaluate "x LIKE 'abc%'" as a range
** expression: "x>='ABC' AND x<'abd'".  But this requires that the range
** scan loop run twice, once for strings and a second time for BLOBs.
** The OP_String opcodes on the second pass convert the upper and lower
** bound string contants to blobs.  This routine makes the necessary changes
** to the OP_String opcodes for that to happen.
**
** Except, of course, if SQLITE_LIKE_DOESNT_MATCH_BLOBS is defined, then
** only the one pass through the string space is required, so this routine
** becomes a no-op.
*/
static void whereLikeOptimizationStringFixup(
  Vdbe *v,                /* prepared statement under construction */
  WhereLevel *pLevel,     /* The loop that contains the LIKE operator */
  WhereTerm *pTerm        /* The upper or lower bound just coded */
){
  if( pTerm->wtFlags & TERM_LIKEOPT ){
    VdbeOp *pOp;
    assert( pLevel->iLikeRepCntr>0 );
    pOp = sqlite3VdbeGetOp(v, -1);
    assert( pOp!=0 );
    assert( pOp->opcode==OP_String8 
            || pTerm->pWC->pWInfo->pParse->db->mallocFailed );
    pOp->p3 = pLevel->iLikeRepCntr;
    pOp->p5 = 1;
  }
}
#else
# define whereLikeOptimizationStringFixup(A,B,C)
#endif

#ifdef SQLITE_ENABLE_CURSOR_HINTS
/*
** Information is passed from codeCursorHint() down to individual nodes of
** the expression tree (by sqlite3WalkExpr()) using an instance of this
** structure.
*/

      /* Like optimization range constraints always occur in pairs */
      assert( (pRangeStart->wtFlags & TERM_LIKEOPT)==0 || 
              (pLoop->wsFlags & WHERE_TOP_LIMIT)!=0 );
    }
    if( pLoop->wsFlags & WHERE_TOP_LIMIT ){
      pRangeEnd = pLoop->aLTerm[j++];
      nExtraReg = 1;
#ifndef SQLITE_LIKE_DOESNT_MATCH_BLOBS
      if( (pRangeEnd->wtFlags & TERM_LIKEOPT)!=0 ){
        assert( pRangeStart!=0 );                     /* LIKE opt constraints */
        assert( pRangeStart->wtFlags & TERM_LIKEOPT );   /* occur in pairs */
        pLevel->iLikeRepCntr = ++pParse->nMem;
        testcase( bRev );
        testcase( pIdx->aSortOrder[nEq]==SQLITE_SO_DESC );
        sqlite3VdbeAddOp2(v, OP_Integer,
                          bRev ^ (pIdx->aSortOrder[nEq]==SQLITE_SO_DESC),
                          pLevel->iLikeRepCntr);
        VdbeComment((v, "LIKE loop counter"));
        pLevel->addrLikeRep = sqlite3VdbeCurrentAddr(v);
      }
#endif
      if( pRangeStart==0
       && (j = pIdx->aiColumn[nEq])>=0 
       && pIdx->pTable->aCol[j].notNull==0
      ){
        bSeekPastNull = 1;
      }
    }

    }
    pE = pTerm->pExpr;
    assert( pE!=0 );
    if( pLevel->iLeftJoin && !ExprHasProperty(pE, EP_FromJoin) ){
      continue;
    }
    if( pTerm->wtFlags & TERM_LIKECOND ){
#ifdef SQLITE_LIKE_DOESNT_MATCH_BLOBS
      continue;
#else
      assert( pLevel->iLikeRepCntr>0 );
      skipLikeAddr = sqlite3VdbeAddOp1(v, OP_IfNot, pLevel->iLikeRepCntr);
      VdbeCoverage(v);
#endif
    }
    sqlite3ExprIfFalse(pParse, pE, addrCont, SQLITE_JUMPIFNULL);
    if( skipLikeAddr ) sqlite3VdbeJumpHere(v, skipLikeAddr);
    pTerm->wtFlags |= TERM_CODED;
  }

  /* Insert code to test for implied constraints based on transitivity

#endif /* SQLITE_OMIT_LIKE_OPTIMIZATION */


#ifndef SQLITE_OMIT_VIRTUALTABLE
/*
** Check to see if the given expression is of the form
**
**         column OP expr
**
** where OP is one of MATCH, GLOB, LIKE or REGEXP and "column" is a 
** column of a virtual table.
**
** If it is then return TRUE.  If not, return FALSE.
*/
static int isMatchOfColumn(
  Expr *pExpr,                    /* Test this expression */
  unsigned char *peOp2            /* OUT: 0 for MATCH, or else an op2 value */
){
  struct Op2 {
    const char *zOp;
    unsigned char eOp2;
  } aOp[] = {
    { "match",  SQLITE_INDEX_CONSTRAINT_MATCH },
    { "glob",   SQLITE_INDEX_CONSTRAINT_GLOB },
    { "like",   SQLITE_INDEX_CONSTRAINT_LIKE },
    { "regexp", SQLITE_INDEX_CONSTRAINT_REGEXP }
  };
  ExprList *pList;
  Expr *pCol;                     /* Column reference */
  int i;

  if( pExpr->op!=TK_FUNCTION ){
    return 0;
  }
  pList = pExpr->x.pList;
  if( pList==0 || pList->nExpr!=2 ){
    return 0;
  }

  pCol = pList->a[1].pExpr;
  if( pCol->op!=TK_COLUMN || !IsVirtual(pCol->pTab) ){
    return 0;
  }
  for(i=0; i<ArraySize(aOp); i++){
    if( sqlite3StrICmp(pExpr->u.zToken, aOp[i].zOp)==0 ){
      *peOp2 = aOp[i].eOp2;
      return 1;
    }
  }
  return 0;
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */

/*
** If the pBase expression originated in the ON or USING clause of
** a join, then transfer the appropriate markings over to derived.
*/

  Bitmask extraRight = 0;          /* Extra dependencies on LEFT JOIN */
  Expr *pStr1 = 0;                 /* RHS of LIKE/GLOB operator */
  int isComplete = 0;              /* RHS of LIKE/GLOB ends with wildcard */
  int noCase = 0;                  /* uppercase equivalent to lowercase */
  int op;                          /* Top-level operator.  pExpr->op */
  Parse *pParse = pWInfo->pParse;  /* Parsing context */
  sqlite3 *db = pParse->db;        /* Database connection */
  unsigned char eOp2;              /* op2 value for LIKE/REGEXP/GLOB */

  if( db->mallocFailed ){
    return;
  }
  pTerm = &pWC->a[idxTerm];
  pMaskSet = &pWInfo->sMaskSet;
  pExpr = pTerm->pExpr;

#ifndef SQLITE_OMIT_VIRTUALTABLE
  /* Add a WO_MATCH auxiliary term to the constraint set if the
  ** current expression is of the form:  column MATCH expr.
  ** This information is used by the xBestIndex methods of
  ** virtual tables.  The native query optimizer does not attempt
  ** to do anything with MATCH functions.
  */
  if( isMatchOfColumn(pExpr, &eOp2) ){
    int idxNew;
    Expr *pRight, *pLeft;
    WhereTerm *pNewTerm;
    Bitmask prereqColumn, prereqExpr;

    pRight = pExpr->x.pList->a[0].pExpr;
    pLeft = pExpr->x.pList->a[1].pExpr;
    prereqExpr = sqlite3WhereExprUsage(pMaskSet, pRight);
    prereqColumn = sqlite3WhereExprUsage(pMaskSet, pLeft);
    if( (prereqExpr & prereqColumn)==0 ){
      Expr *pNewExpr;
      pNewExpr = sqlite3PExpr(pParse, TK_MATCH, 
                              0, sqlite3ExprDup(db, pRight, 0), 0);
      idxNew = whereClauseInsert(pWC, pNewExpr, TERM_VIRTUAL|TERM_DYNAMIC);
      testcase( idxNew==0 );
      pNewTerm = &pWC->a[idxNew];
      pNewTerm->prereqRight = prereqExpr;
      pNewTerm->leftCursor = pLeft->iTable;
      pNewTerm->u.leftColumn = pLeft->iColumn;
      pNewTerm->eOperator = WO_MATCH;
      pNewTerm->eMatchOp = eOp2;
      markTermAsChild(pWC, idxNew, idxTerm);
      pTerm = &pWC->a[idxTerm];
      pTerm->wtFlags |= TERM_COPIED;
      pNewTerm->prereqAll = pTerm->prereqAll;
    }
  }
#endif /* SQLITE_OMIT_VIRTUALTABLE */

  pWC->nTerm = 0;
  pWC->nSlot = ArraySize(pWC->aStatic);
  pWC->a = pWC->aStatic;
}

/*
** Deallocate a WhereClause structure.  The WhereClause structure
** itself is not freed.  This routine is the inverse of
** sqlite3WhereClauseInit().
*/
void sqlite3WhereClauseClear(WhereClause *pWC){
  int i;
  WhereTerm *a;
  sqlite3 *db = pWC->pWInfo->pParse->db;
  for(i=pWC->nTerm-1, a=pWC->a; i>=0; i--, a++){
    if( a->wtFlags & TERM_DYNAMIC ){

  ExprList *pArgs;
  Expr *pColRef;
  Expr *pTerm;
  if( pItem->fg.isTabFunc==0 ) return;
  pTab = pItem->pTab;
  assert( pTab!=0 );
  pArgs = pItem->u1.pFuncArg;
  if( pArgs==0 ) return;
  for(j=k=0; j<pArgs->nExpr; j++){
    while( k<pTab->nCol && (pTab->aCol[k].colFlags & COLFLAG_HIDDEN)==0 ){k++;}
    if( k>=pTab->nCol ){
      sqlite3ErrorMsg(pParse, "too many arguments on %s() - max %d",
                      pTab->zName, j);
      return;
    }
    pColRef = sqlite3PExpr(pParse, TK_COLUMN, 0, 0, 0);
    if( pColRef==0 ) return;

} {}
do_eqp_test analyze3-2.2 {
  SELECT count(a) FROM t1 WHERE b LIKE 'a%'
} {0 0 0 {SEARCH TABLE t1 USING INDEX i1 (b>? AND b<?)}}
do_eqp_test analyze3-2.3 {
  SELECT count(a) FROM t1 WHERE b LIKE '%a'
} {0 0 0 {SCAN TABLE t1}}

# Return the first argument if like_match_blobs is true (the default)
# or the second argument if not
#
proc ilmb {a b} {
  ifcapable like_match_blobs {return $a}
  return $b
}

do_test analyze3-2.4 {
  sf_execsql { SELECT count(*) FROM t1 WHERE b LIKE 'a%' }
} [list [ilmb 102 101] 0 100]
do_test analyze3-2.5 {
  sf_execsql { SELECT count(*) FROM t1 WHERE b LIKE '%a' }
} {999 999 100}

do_test analyze3-2.6 {
  set like "a%"
  sf_execsql { SELECT count(*) FROM t1 WHERE b LIKE $like }
} [list [ilmb 102 101] 0 100]
do_test analyze3-2.7 {
  set like "%a"
  sf_execsql { SELECT count(*) FROM t1 WHERE b LIKE $like }
} {999 999 100}
do_test analyze3-2.8 {
  set like "a"
  sf_execsql { SELECT count(*) FROM t1 WHERE b LIKE $like }
} [list [ilmb 102 101] 0 0]
do_test analyze3-2.9 {
  set like "ab"
  sf_execsql { SELECT count(*) FROM t1 WHERE b LIKE $like }
} [list [ilmb 12 11] 0 0]
do_test analyze3-2.10 {
  set like "abc"
  sf_execsql { SELECT count(*) FROM t1 WHERE b LIKE $like }
} [list [ilmb 3 2] 0 1]
do_test analyze3-2.11 {
  set like "a_c"
  sf_execsql { SELECT count(*) FROM t1 WHERE b LIKE $like }
} [list [ilmb 102 101] 0 10]


#-------------------------------------------------------------------------
# This block of tests checks that statements are correctly marked as
# expired when the values bound to any parameters that may affect the 
# query plan are modified.
#

# test the new sqlite3_prepare_v2 interface.
#
# $Id: capi3c.test,v 1.23 2009/07/22 07:27:57 danielk1977 Exp $
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
set testprefix capi3c

# Do not use a codec for tests in this file, as the database file is
# manipulated directly using tcl scripts (using the [hexio_write] command).
#
do_not_use_codec

# Return the UTF-16 representation of the supplied UTF-8 string $str.

    FROM (SELECT * FROM t5 ORDER BY c LIMIT 1) ORDER BY b
  }
} {DATETIME}
do_test capi3c-24.3 {
  decltype {SELECT (SELECT x FROM (SELECT t5.a AS x)) FROM t5}
} {INTEGER}


# Further tests of sqlite3_column_decltype():
#
do_execsql_test 25.0 {
  CREATE TABLE t11(a VARCHAR(10), b INTEGER);
  CREATE TABLE t12(a VARCHAR(15), b FLOAT);
}

foreach {tn sql} {
  1 "SELECT * FROM t11 UNION ALL SELECT * FROM t12"
  2 "SELECT * FROM t11 UNION SELECT * FROM t12"
  3 "SELECT * FROM t11 EXCEPT SELECT * FROM t12"
  4 "SELECT * FROM t11 INTERSECT SELECT * FROM t12"

  5 "SELECT * FROM t11 UNION ALL SELECT * FROM t12 ORDER BY 1"
  6 "SELECT * FROM t11 UNION SELECT * FROM t12 ORDER BY 1"
  7 "SELECT * FROM t11 EXCEPT SELECT * FROM t12 ORDER BY 1"
  8 "SELECT * FROM t11 INTERSECT SELECT * FROM t12 ORDER BY 1"
} {
  do_test 25.$tn { decltype $sql } {VARCHAR(10) INTEGER}
}

finish_test

  INSERT INTO kv SELECT NULL, randomblob(750) FROM kv;
  INSERT INTO kv SELECT NULL, randomblob(750) FROM kv;
  INSERT INTO kv SELECT NULL, randomblob(750) FROM kv;
  INSERT INTO kv SELECT NULL, randomblob(750) FROM kv;
  INSERT INTO kv SELECT NULL, randomblob(750) FROM kv;
  DELETE FROM kv WHERE rowid%2;
  PRAGMA freelist_count;
} {wal 34}
do_execsql_test 8.2 { PRAGMA integrity_check } ok
do_execsql_test 8.3 { 
  BEGIN CONCURRENT;
    PRAGMA integrity_check;
} {ok}
do_execsql_test 8.4 { 
    INSERT INTO kv VALUES(1100, 1100);

      COMMIT;
    }
  } {}
}


finish_test

} {1 2 3 4 5 6}
do_execsql_test 5.5 {
  SELECT DISTINCT x FROM t1 ORDER BY x DESC;
} {6 5 4 3 2 1}
do_execsql_test 5.6 {
  SELECT DISTINCT x FROM t1 ORDER BY x;
} {1 2 3 4 5 6}

#-------------------------------------------------------------------------
# 2015-11-23.  Problem discovered by Kostya Serebryany using libFuzzer
#
db close
sqlite3 db :memory:
do_execsql_test 6.1 {
  CREATE TABLE jjj(x);
  SELECT (SELECT 'mmm' UNION SELECT DISTINCT max(name) ORDER BY 1) 
    FROM sqlite_master;
} {jjj}
do_execsql_test 6.2 {
  CREATE TABLE nnn(x);
  SELECT (SELECT 'mmm' UNION SELECT DISTINCT max(name) ORDER BY 1) 
    FROM sqlite_master;
} {mmm}


finish_test

      PRAGMA encoding
    }
  } {UTF-16le}
  do_test enc3-2.2 {
    execsql {
      CREATE TABLE t2(a);
      INSERT INTO t2 VALUES(x'61006200630064006500');
      SELECT CAST(a AS text) FROM t2 WHERE CAST(a AS text) LIKE 'abc%';
    }
  } {abcde}
  do_test enc3-2.3 {
    execsql {
      SELECT CAST(x'61006200630064006500' AS text);
    }
  } {abcde}
  do_test enc3-2.4 {
    execsql {
      SELECT rowid FROM t2
       WHERE CAST(a AS text) LIKE CAST(x'610062002500' AS text);
    }
  } {1}
}

# Try to attach a database with a different encoding.
#
ifcapable {utf16 && shared_cache} {

do_execsql_test 10.1 {
  CREATE TABLE idx(id INTEGER PRIMARY KEY, path TEXT);
  INSERT INTO idx VALUES (1, 't1.txt');
  INSERT INTO idx VALUES (2, 't2.txt');
  INSERT INTO idx VALUES (3, 't3.txt');

  CREATE VIRTUAL TABLE vt USING fs(idx);
  SELECT path, data FROM vt;
} {
  1 {a b c d e f g h i j k l m n o p q r s t u v w x y z} 
  2 {a b c d e f g h i j k l m a b c d e f g h i j k l m}
  3 {n o p q r s t u v w x y z n o p q r s t u v w x y z}
}

do_execsql_test 10.2 {
  SELECT path, data FROM vt WHERE rowid = 2;
} {
  2 {a b c d e f g h i j k l m a b c d e f g h i j k l m}
}

do_execsql_test 10.3 {
  CREATE VIRTUAL TABLE ft USING fts4(content=vt);
  INSERT INTO ft(ft) VALUES('rebuild');

  int nOut,
  char *zOut
){
  sqlite3_snprintf(nOut, zOut, "%s", zFilename);
  return SQLITE_OK;
}






/*
** Register the VFS that reads from the g.aFile[] set of files.
*/
static void inmemVfsRegister(void){
  static sqlite3_vfs inmemVfs;
  sqlite3_vfs *pDefault = sqlite3_vfs_find(0);
  inmemVfs.iVersion = 3;
  inmemVfs.szOsFile = sizeof(VHandle);
  inmemVfs.mxPathname = 200;
  inmemVfs.zName = "inmem";
  inmemVfs.xOpen = inmemOpen;
  inmemVfs.xDelete = inmemDelete;
  inmemVfs.xAccess = inmemAccess;
  inmemVfs.xFullPathname = inmemFullPathname;
  inmemVfs.xRandomness = pDefault->xRandomness;
  inmemVfs.xSleep = pDefault->xSleep;
  inmemVfs.xCurrentTimeInt64 = pDefault->xCurrentTimeInt64;

  sqlite3_vfs_register(&inmemVfs, 0);
};

/*
** Allowed values for the runFlags parameter to runSql()
*/
#define SQL_TRACE  0x0001     /* Print each SQL statement as it is prepared */

} {0}

# Oversized hex literals are rejected
#
do_catchsql_test hexlist-400 {
  SELECT 0x10000000000000000;
} {1 {hex literal too big: 0x10000000000000000}}
do_catchsql_test hexlist-401 {
  SELECT DISTINCT 0x10000000000000000;
} {1 {hex literal too big: 0x10000000000000000}}
do_catchsql_test hexlist-410 {
  DROP TABLE IF EXISTS t1;
  CREATE TABLE t1(x);
  INSERT INTO t1 VALUES(1+0x10000000000000000);
} {1 {hex literal too big: 0x10000000000000000}}

    }
  } {12 123 scan 5 like 6}
  do_test like-10.4 {
    count {
      SELECT a FROM t10 WHERE e LIKE '12%' ORDER BY +a;
    }
  } {12 123 scan 5 like 6}
  ifcapable like_match_blobs {
    do_test like-10.5a {
      count {
        SELECT a FROM t10 WHERE f LIKE '12%' ORDER BY +a;
      }
    } {12 123 scan 4 like 0}
  } else {
    do_test like-10.5b {
      count {
        SELECT a FROM t10 WHERE f LIKE '12%' ORDER BY +a;
      }
    } {12 123 scan 3 like 0}
  }
  do_test like-10.6 {
    count {
      SELECT a FROM t10 WHERE a LIKE '12%' ORDER BY +a;
    }
  } {12 123 scan 5 like 6}
  do_test like-10.10 {
    execsql {

    }
  } {12 123 scan 5 like 6}
  do_test like-10.13 {
    count {
      SELECT a FROM t10b WHERE e GLOB '12*' ORDER BY +a;
    }
  } {12 123 scan 5 like 6}
  ifcapable like_match_blobs {
    do_test like-10.14 {
      count {
        SELECT a FROM t10b WHERE f GLOB '12*' ORDER BY +a;
      }
    } {12 123 scan 4 like 0}
  } else {
    do_test like-10.14 {
      count {
        SELECT a FROM t10b WHERE f GLOB '12*' ORDER BY +a;
      }
    } {12 123 scan 3 like 0}
  }
  do_test like-10.15 {
    count {
      SELECT a FROM t10b WHERE a GLOB '12*' ORDER BY +a;
    }
  } {12 123 scan 5 like 6}
}

#     SELECT 'query-2', x FROM t1 WHERE +x LIKE 'a%';
#
# This script verifies that it works right now.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl

ifcapable !like_match_blobs {
  finish_test
  return
}

do_execsql_test like3-1.1 {
  PRAGMA encoding=UTF8;
  CREATE TABLE t1(a,b TEXT COLLATE nocase);
  INSERT INTO t1(a,b)
     VALUES(1,'abc'),
           (2,'ABX'),

} {X'616265' X'616264' X'616263' 'abe' 'abd' 'abc'}
do_execsql_test like3-4.2 {
  SELECT quote(x) FROM t4 WHERE x LIKE 'ab%' ORDER BY x ASC;
} {'abc' 'abd' 'abe' X'616263' X'616264' X'616265'}
do_execsql_test like3-4.2ck {
  SELECT quote(x) FROM t4 WHERE x LIKE 'ab%' ORDER BY +x ASC;
} {'abc' 'abd' 'abe' X'616263' X'616264' X'616265'}



finish_test

# The following query (provided by Kostya Serebryany) used to take 25
# minutes to prepare.  This has been speeded up to about 250 milliseconds.
#
do_catchsql_test misc1-25.0 {
SELECT-1 UNION  SELECT 5 UNION SELECT 0 UNION SElECT*from(SELECT-5) UNION SELECT*from(SELECT-0) UNION  SELECT:SELECT-0 UNION SELECT-1 UNION SELECT 1 UNION SELECT 1 ORDER BY S  in(WITH K AS(WITH K AS(select'CREINDERcharREADEVIRTUL5TABLECONFLICT !1 USIN'' MFtOR(b38q,eWITH K AS(selectCREATe TABLE t0(a,b,c,d,e, PRIMARY KEY(a,b,c,d,c,a,b,b,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,d,c,a,b,c,e,d,d,c,a,b,b,c,c,a,b,b,c,d,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,a,b,b,c,d,c,a,c,d,c,d,c,e,d,d,c,a,b,b,c,c,a,b,b,E,d,c,d,c,b,c,d,c,d,c,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,a,b,c,e,d,d,c,a,b,b,c,d,d,c,a,b,c,e,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,a,b,c,e,d,d,c,a,b,b,b,c,e,d,d,c,a,b,b,c,c,a,b,b,c,d,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,d,c,e,d,d,c,a,b,b,c,c,a,b,b,E,d,c,d,c,b,c,d,c,d,c,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,c,d'CEIl,k'',ab, g, a,b,o11b, i'nEX/charREDE IVT LR!VABLt5SG',N  ,N in rement,l_vacuum,M&U,'te3(''5l' a,bB,b,l*e)SELECT:SELECT, *,*,*from(( SELECT
$group,:conc ap0,1)fro,(select"",:PBAG,c,a,b,b,c,a,b,c,e,d,d,c,a,b,b,c,d,d,c,a,b,c,e,d,c,d,c,a,b,c,e,c,d,c,d,c,a,b,b,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,d,c,a,b,c,e,d,d,c,a,b,b,c,c,a,b,b,c,d,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,a,b,c,e,d,d,c,a,b,b,b,c,e,d,d,c,a,b,b,c,c,a,b,b,c,d,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,d,c,e,d,d,c,a,b,b,c,c,a,b,b,E,d,c,d,c,b,c,d,c,d,c,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,a,b,c,e,d,d,c,a,b,b,c,d,d,c,a,b,c,e,d,c,d,c,a,b,c,e,c,d,c,d,c,a,b,b,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,d,c,a,b,c,e,d,d,c,a,b,b,c,c,a,b,b,c,d,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,d,c,e,d,d,c,a,b,b,c,c,a,b,b,E,d,c,d,c,b,c,d,c,d,c,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,a,b,c,e,d,d,c,a,b,b,c,d,d,c,a,b,c,e,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,c,d,c,c,a,a,b,d,d,c,a,b,b,c,d,c,a,b,e,e,d,b,c,d,c,a,b,b,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,d,c,a,b,c,e,d,d,c,a,b,b,c,c,a,b,b,c,d,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d, foreign_keysc,d,c,e,d,d,c,a,b,b,c,c,a,b,b,E,d,c,d,c,b,c,d,c,d,c,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,a,b,d,d,c,a,b,b,c,d,c,a,b,e,e,d,b,c,d,c,a,b,b,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,d,c,a,b,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,d,c,e,d,d,c,a,b,b,c,c,a,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,d,c,a,b,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,d,c,e,d,d,c,a,b,b,c,c,a,b,b,E,d,c,d,c,b,c,d,c,d,c,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,a,b,c,e,d,d,c,a,b,b,c,d,d,c,a,b,c,e,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,c,d,c,a,b,d,d,c,a,a,b,d,d,c,a,b,b,c,d,c,a,b,e,e,d,b,c,d,c,a,b,b,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,d,c,a,b,c,e,d,d,c,a,b,b,c,c,a,b,b,c,d,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,d,c,e,d,d,c,a,b,b,c,c,a,b,b,E,d,c,d,c,b,c,d,c,d,c,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,a,b,d,d,c,a,b,b,c,d,c,a,b,e,e,d,b,c,d,c,a,b,b,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,d,c,a,b,c,e,d,d,c,a,b,b,c,c,a,b,b,c,d,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,d,c,e,d,d,c,a,b,b,c,c,a,b,b,E,d,c,d,c,b,c,d,c,d,c,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,a,bb,b,E,d,c,d,c,b,c,d,c,d,c,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,a,b,c,e,d,d,c,a,b,b,c,d,d,c,a,b,c,e,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,c,d,c,a,b,d,d,c,a,a,b,d,d,c,a,b,b,c,d,c,a,b,e,e,d,b,c,d,c,a,b,b,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,MAato_aecSELEC,+?b," "O,"i","a",""b  ,5 ))KEY)SELECT*FROM((k()reaC,k,K) eA,k '' )t ,K  M);
} {1 {'k' is not a function}}


finish_test

do_test sqllimits1-16.2 {
  set ::format "[string repeat A 60][string repeat "%J" $::N]"
  catchsql {
    SELECT strftime($::format, 1);
  }
} {1 {string or blob too big}}

do_catchsql_test sqllimits1.17.0 {
  SELECT *,*,*,*,*,*,*,* FROM (
  SELECT *,*,*,*,*,*,*,* FROM (
  SELECT *,*,*,*,*,*,*,* FROM (
  SELECT *,*,*,*,*,*,*,* FROM (
  SELECT *,*,*,*,*,*,*,* FROM (
    SELECT 1,2,3,4,5,6,7,8,9,10
  )
  ))))
} "1 {too many columns in result set}"


foreach {key value} [array get saved] {
  catch {set $key $value}
}
finish_test

} 1
do_test 2.4 {
  file exists test.db2-wal
} 0
do_execsql_test 2.5 {
  SELECT * FROM t1;
} {1 2}

# Try to open a ridiculously long pathname.  Bug found by
# Kostya Serebryany using libFuzzer on 2015-11-30.
#
do_test 3.1 {
  db close
  catch {sqlite3 db [string repeat [string repeat x 100]/ 6]} res
  set res
} {unable to open database file}


finish_test

#-------------------------------------------------------------------------
# Tests for the xNextSystemCall method.
#
foreach s {
    open close access getcwd stat fstat ftruncate
    fcntl read pread write pwrite fchmod fallocate
    pread64 pwrite64 unlink openDirectory mkdir rmdir 
    statvfs fchown geteuid umask mmap munmap mremap
    getpagesize readlink
} {
  if {[test_syscall exists $s]} {lappend syscall_list $s}
}
do_test 3.1 { lsort [test_syscall list] } [lsort $syscall_list]

#-------------------------------------------------------------------------

  SELECT rowid, * FROM generate_series(0,32,5) ORDER BY +value DESC;
} {7 30 6 25 5 20 4 15 3 10 2 5 1 0}

do_execsql_test tabfunc01-1.20 {
  CREATE VIEW v1(a,b) AS VALUES(1,2),(3,4);
  SELECT * FROM v1;
} {1 2 3 4}
do_catchsql_test tabfunc01-1.21.1 {
  SELECT * FROM v1(55);
} {1 {'v1' is not a function}}
do_catchsql_test tabfunc01-1.21.2 {
  SELECT * FROM v1();
} {1 {'v1' is not a function}}
do_execsql_test tabfunc01-1.22 {
  CREATE VIEW v2(x) AS SELECT value FROM generate_series(1,5);
  SELECT * FROM v2;
} {1 2 3 4 5}
do_catchsql_test tabfunc01-1.23.1 {
  SELECT * FROM v2(55);
} {1 {'v2' is not a function}}
do_catchsql_test tabfunc01-1.23.2 {
  SELECT * FROM v2();
} {1 {'v2' is not a function}}
do_execsql_test tabfunc01-1.24 {
  CREATE TABLE t0(x);
  INSERT INTO t0(x) VALUES(123),(456),(789);
  SELECT * FROM t0 ORDER BY x;
} {123 456 789}
do_catchsql_test tabfunc01-1.25 {
  SELECT * FROM t0(55) ORDER BY x;
} {1 {'t0' is not a function}}
do_catchsql_test tabfunc01-1.26 {
  WITH w0 AS (SELECT * FROM t0)
  INSERT INTO t0(x) SELECT * FROM w0()
} {1 {'w0' is not a function}}

do_execsql_test tabfunc01-2.1 {
  CREATE TABLE t1(x);
  INSERT INTO t1(x) VALUES(2),(3);
  SELECT *, '|' FROM t1, generate_series(1,x) ORDER BY 1, 2
} {2 1 | 2 2 | 3 1 | 3 2 | 3 3 |}
do_execsql_test tabfunc01-2.2 {