**   This exists in order to allow the fts5_index.c module to return a 
**   decent error message if it encounters a file-format version it does
**   not understand.
**
** bColumnsize:
**   True if the %_docsize table is created.
**






*/
struct Fts5Config {
  sqlite3 *db;                    /* Database handle */
  char *zDb;                      /* Database holding FTS index (e.g. "main") */
  char *zName;                    /* Name of FTS index */
  int nCol;                       /* Number of columns */
  char **azCol;                   /* Column names */
................................................................................
  int nAutomerge;                 /* 'automerge' setting */
  int nCrisisMerge;               /* Maximum allowed segments per level */
  char *zRank;                    /* Name of rank function */
  char *zRankArgs;                /* Arguments to rank function */

  /* If non-NULL, points to sqlite3_vtab.base.zErrmsg. Often NULL. */
  char **pzErrmsg;




};

/* Current expected value of %_config table 'version' field */
#define FTS5_CURRENT_VERSION 3

#define FTS5_CONTENT_NORMAL   0
#define FTS5_CONTENT_NONE     1
#define FTS5_CONTENT_EXTERNAL 2



................................................................................
** Discard any data stored in the in-memory hash tables. Do not write it
** to the database. Additionally, assume that the contents of the %_data
** table may have changed on disk. So any in-memory caches of %_data 
** records must be invalidated.
*/
int sqlite3Fts5IndexRollback(Fts5Index *p);

/*
** Retrieve and clear the current error code, respectively.
*/
int sqlite3Fts5IndexErrcode(Fts5Index*);
void sqlite3Fts5IndexReset(Fts5Index*);

/*
** Get or set the "averages" values.
*/
int sqlite3Fts5IndexGetAverages(Fts5Index *p, i64 *pnRow, i64 *anSize);
int sqlite3Fts5IndexSetAverages(Fts5Index *p, const u8*, int);

/*
................................................................................
/**************************************************************************
** Interface to code in fts5_tokenizer.c. 
*/

int sqlite3Fts5TokenizerInit(fts5_api*);
/*
** End of interface to code in fts5_tokenizer.c.
**************************************************************************/

/**************************************************************************
** Interface to code in fts5_sorter.c. 
*/
typedef struct Fts5Sorter Fts5Sorter;

int sqlite3Fts5SorterNew(Fts5Expr *pExpr, Fts5Sorter **pp);

/*
** End of interface to code in fts5_sorter.c.
**************************************************************************/

/**************************************************************************
** Interface to code in fts5_vocab.c. 
*/

int sqlite3Fts5VocabInit(Fts5Global*, sqlite3*);

**   This exists in order to allow the fts5_index.c module to return a 
**   decent error message if it encounters a file-format version it does
**   not understand.
**
** bColumnsize:
**   True if the %_docsize table is created.
**
** bPrefixIndex:
**   This is only used for debugging. If set to false, any prefix indexes
**   are ignored. This value is configured using:
**
**       INSERT INTO tbl(tbl, rank) VALUES('prefix-index', $bPrefixIndex);
**
*/
struct Fts5Config {
  sqlite3 *db;                    /* Database handle */
  char *zDb;                      /* Database holding FTS index (e.g. "main") */
  char *zName;                    /* Name of FTS index */
  int nCol;                       /* Number of columns */
  char **azCol;                   /* Column names */
................................................................................
  int nAutomerge;                 /* 'automerge' setting */
  int nCrisisMerge;               /* Maximum allowed segments per level */
  char *zRank;                    /* Name of rank function */
  char *zRankArgs;                /* Arguments to rank function */

  /* If non-NULL, points to sqlite3_vtab.base.zErrmsg. Often NULL. */
  char **pzErrmsg;

#ifdef SQLITE_DEBUG
  int bPrefixIndex;               /* True to use prefix-indexes */
#endif
};

/* Current expected value of %_config table 'version' field */
#define FTS5_CURRENT_VERSION 4

#define FTS5_CONTENT_NORMAL   0
#define FTS5_CONTENT_NONE     1
#define FTS5_CONTENT_EXTERNAL 2



................................................................................
** Discard any data stored in the in-memory hash tables. Do not write it
** to the database. Additionally, assume that the contents of the %_data
** table may have changed on disk. So any in-memory caches of %_data 
** records must be invalidated.
*/
int sqlite3Fts5IndexRollback(Fts5Index *p);







/*
** Get or set the "averages" values.
*/
int sqlite3Fts5IndexGetAverages(Fts5Index *p, i64 *pnRow, i64 *anSize);
int sqlite3Fts5IndexSetAverages(Fts5Index *p, const u8*, int);

/*
................................................................................
/**************************************************************************
** Interface to code in fts5_tokenizer.c. 
*/

int sqlite3Fts5TokenizerInit(fts5_api*);
/*
** End of interface to code in fts5_tokenizer.c.











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

/**************************************************************************
** Interface to code in fts5_vocab.c. 
*/

int sqlite3Fts5VocabInit(Fts5Global*, sqlite3*);

*/



#include "fts5Int.h"

int sqlite3Fts5BufferGrow(int *pRc, Fts5Buffer *pBuf, int nByte){
  /* A no-op if an error has already occurred */
  if( *pRc ) return 1;

  if( (pBuf->n + nByte) > pBuf->nSpace ){
    u8 *pNew;
    int nNew = pBuf->nSpace ? pBuf->nSpace*2 : 64;




    while( nNew<(pBuf->n + nByte) ){
      nNew = nNew * 2;
    }
    pNew = sqlite3_realloc(pBuf->p, nNew);
    if( pNew==0 ){
      *pRc = SQLITE_NOMEM;
      return 1;

*/



#include "fts5Int.h"

int sqlite3Fts5BufferGrow(int *pRc, Fts5Buffer *pBuf, int nByte){



  if( (pBuf->n + nByte) > pBuf->nSpace ){
    u8 *pNew;
    int nNew = pBuf->nSpace ? pBuf->nSpace*2 : 64;

    /* A no-op if an error has already occurred */
    if( *pRc ) return 1;

    while( nNew<(pBuf->n + nByte) ){
      nNew = nNew * 2;
    }
    pNew = sqlite3_realloc(pBuf->p, nNew);
    if( pNew==0 ){
      *pRc = SQLITE_NOMEM;
      return 1;

  nByte = nArg * (sizeof(char*) + sizeof(u8));
  pRet->azCol = (char**)sqlite3Fts5MallocZero(&rc, nByte);
  pRet->abUnindexed = (u8*)&pRet->azCol[nArg];
  pRet->zDb = sqlite3Fts5Strndup(&rc, azArg[1], -1);
  pRet->zName = sqlite3Fts5Strndup(&rc, azArg[2], -1);
  pRet->bColumnsize = 1;



  if( rc==SQLITE_OK && sqlite3_stricmp(pRet->zName, FTS5_RANK_NAME)==0 ){
    *pzErr = sqlite3_mprintf("reserved fts5 table name: %s", pRet->zName);
    rc = SQLITE_ERROR;
  }

  for(i=3; rc==SQLITE_OK && i<nArg; i++){
    const char *zOrig = azArg[i];

  nByte = nArg * (sizeof(char*) + sizeof(u8));
  pRet->azCol = (char**)sqlite3Fts5MallocZero(&rc, nByte);
  pRet->abUnindexed = (u8*)&pRet->azCol[nArg];
  pRet->zDb = sqlite3Fts5Strndup(&rc, azArg[1], -1);
  pRet->zName = sqlite3Fts5Strndup(&rc, azArg[2], -1);
  pRet->bColumnsize = 1;
#ifdef SQLITE_DEBUG
  pRet->bPrefixIndex = 1;
#endif
  if( rc==SQLITE_OK && sqlite3_stricmp(pRet->zName, FTS5_RANK_NAME)==0 ){
    *pzErr = sqlite3_mprintf("reserved fts5 table name: %s", pRet->zName);
    rc = SQLITE_ERROR;
  }

  for(i=3; rc==SQLITE_OK && i<nArg; i++){
    const char *zOrig = azArg[i];

*/
static int fts5ExprSynonymPoslist(
  Fts5ExprTerm *pTerm, 
  i64 iRowid,
  int *pbDel,                     /* OUT: Caller should sqlite3_free(*pa) */
  u8 **pa, int *pn
){
  Fts5PoslistWriter writer = {0};
  Fts5PoslistReader aStatic[4];
  Fts5PoslistReader *aIter = aStatic;
  int nIter = 0;
  int nAlloc = 4;
  int rc = SQLITE_OK;
  Fts5ExprTerm *p;

................................................................................
static int fts5ExprNearAdvanceFirst(
  Fts5Expr *pExpr,                /* Expression pPhrase belongs to */
  Fts5ExprNode *pNode,            /* FTS5_STRING or FTS5_TERM node */
  int bFromValid,
  i64 iFrom 
){
  Fts5ExprTerm *pTerm = &pNode->pNear->apPhrase[0]->aTerm[0];
  int rc;

  if( pTerm->pSynonym ){
    int bEof = 1;
    Fts5ExprTerm *p;

    /* Find the firstest rowid any synonym points to. */
    i64 iRowid = fts5ExprSynonymRowid(pTerm, pExpr->bDesc, 0);
................................................................................
  do {
    bMatch = 1;
    for(i=0; i<pNear->nPhrase; i++){
      Fts5ExprPhrase *pPhrase = pNear->apPhrase[i];
      for(j=0; j<pPhrase->nTerm; j++){
        Fts5ExprTerm *pTerm = &pPhrase->aTerm[j];
        if( pTerm->pSynonym ){
          Fts5ExprTerm *p;
          int bEof = 1;
          i64 iRowid = fts5ExprSynonymRowid(pTerm, bDesc, 0);
          if( iRowid==iLast ) continue;
          bMatch = 0;
          if( fts5ExprSynonymAdvanceto(pTerm, bDesc, &iLast, &rc) ){
            pNode->bEof = 1;
            return rc;
          }
................................................................................
  Fts5Config *pConfig,
  Fts5Expr *pExpr, 
  int iPhrase, 
  Fts5Expr **ppNew
){
  int rc = SQLITE_OK;             /* Return code */
  Fts5ExprPhrase *pOrig;          /* The phrase extracted from pExpr */
  Fts5ExprPhrase *pCopy;          /* Copy of pOrig */
  int i;                          /* Used to iterate through phrase terms */

  Fts5Expr *pNew = 0;             /* Expression to return via *ppNew */
  Fts5ExprPhrase **apPhrase;      /* pNew->apPhrase */
  Fts5ExprNode *pNode;            /* pNew->pRoot */
  Fts5ExprNearset *pNear;         /* pNew->pRoot->pNear */

  TokenCtx sCtx = {0,0};          /* Context object for fts5ParseTokenize */


  pOrig = pExpr->apExprPhrase[iPhrase];

  pNew = (Fts5Expr*)sqlite3Fts5MallocZero(&rc, sizeof(Fts5Expr));

*/
static int fts5ExprSynonymPoslist(
  Fts5ExprTerm *pTerm, 
  i64 iRowid,
  int *pbDel,                     /* OUT: Caller should sqlite3_free(*pa) */
  u8 **pa, int *pn
){

  Fts5PoslistReader aStatic[4];
  Fts5PoslistReader *aIter = aStatic;
  int nIter = 0;
  int nAlloc = 4;
  int rc = SQLITE_OK;
  Fts5ExprTerm *p;

................................................................................
static int fts5ExprNearAdvanceFirst(
  Fts5Expr *pExpr,                /* Expression pPhrase belongs to */
  Fts5ExprNode *pNode,            /* FTS5_STRING or FTS5_TERM node */
  int bFromValid,
  i64 iFrom 
){
  Fts5ExprTerm *pTerm = &pNode->pNear->apPhrase[0]->aTerm[0];
  int rc = SQLITE_OK;

  if( pTerm->pSynonym ){
    int bEof = 1;
    Fts5ExprTerm *p;

    /* Find the firstest rowid any synonym points to. */
    i64 iRowid = fts5ExprSynonymRowid(pTerm, pExpr->bDesc, 0);
................................................................................
  do {
    bMatch = 1;
    for(i=0; i<pNear->nPhrase; i++){
      Fts5ExprPhrase *pPhrase = pNear->apPhrase[i];
      for(j=0; j<pPhrase->nTerm; j++){
        Fts5ExprTerm *pTerm = &pPhrase->aTerm[j];
        if( pTerm->pSynonym ){


          i64 iRowid = fts5ExprSynonymRowid(pTerm, bDesc, 0);
          if( iRowid==iLast ) continue;
          bMatch = 0;
          if( fts5ExprSynonymAdvanceto(pTerm, bDesc, &iLast, &rc) ){
            pNode->bEof = 1;
            return rc;
          }
................................................................................
  Fts5Config *pConfig,
  Fts5Expr *pExpr, 
  int iPhrase, 
  Fts5Expr **ppNew
){
  int rc = SQLITE_OK;             /* Return code */
  Fts5ExprPhrase *pOrig;          /* The phrase extracted from pExpr */

  int i;                          /* Used to iterate through phrase terms */

  Fts5Expr *pNew = 0;             /* Expression to return via *ppNew */




  TokenCtx sCtx = {0,0};          /* Context object for fts5ParseTokenize */


  pOrig = pExpr->apExprPhrase[iPhrase];

  pNew = (Fts5Expr*)sqlite3Fts5MallocZero(&rc, sizeof(Fts5Expr));

**
**   Then, for each level from 0 to nMax:
**
**     + number of input segments in ongoing merge.
**     + total number of segments in level.
**     + for each segment from oldest to newest:
**         + segment id (always > 0)
**         + b-tree height (1 -> root is leaf, 2 -> root is parent of leaf etc.)
**         + first leaf page number (often 1, always greater than 0)
**         + final leaf page number
**
** 2. The Averages Record:
**
**   A single record within the %_data table. The data is a list of varints.
**   The first value is the number of rows in the index. Then, for each column
**   from left to right, the total number of tokens in the column for all 
**   rows of the table.
**
** 3. Segment leaves:
**
**   TERM DOCLIST FORMAT:
**
**     Most of each segment leaf is taken up by term/doclist data. The 
**     general format of the term/doclist data is:

**
**         varint : size of first term
**         blob:    first term data
**         doclist: first doclist
**         zero-or-more {
**           varint:  number of bytes in common with previous term
**           varint:  number of bytes of new term data (nNew)
................................................................................
**
**         varint:  first rowid
**         poslist: first poslist
**         zero-or-more {
**           varint:  rowid delta (always > 0)
**           poslist: next poslist
**         }
**         0x00 byte
**
**     poslist format:
**
**         varint: size of poslist in bytes multiplied by 2, not including
**                 this field. Plus 1 if this entry carries the "delete" flag.
**         collist: collist for column 0
**         zero-or-more {
................................................................................
**     collist format:
**
**         varint: first offset + 2
**         zero-or-more {
**           varint: offset delta + 2
**         }
**
**   PAGINATION
**
**     The format described above is only accurate if the entire term/doclist

















**     data fits on a single leaf page. If this is not the case, the format
**     is changed in two ways:
**
**       + if the first rowid on a page occurs before the first term, it
**         is stored as a literal value:
**
**             varint:  first rowid
**
**       + the first term on each page is stored in the same way as the
**         very first term of the segment:
**
**             varint : size of first term
**             blob:    first term data
**
**     Each leaf page begins with:
**
**       + 2-byte unsigned containing offset to first rowid (or 0).
**       + 2-byte unsigned containing offset to first term (or 0).
**
**   Followed by term/doclist data.
**
** 4. Segment interior nodes:
**
**   The interior nodes turn the list of leaves into a b+tree. 
**
**   Each interior node begins with a varint - the page number of the left
**   most child node. Following this, for each leaf page except the first,
**   the interior nodes contain:
**
**     a) If the leaf page contains at least one term, then a term-prefix that
**        is greater than all previous terms, and less than or equal to the
**        first term on the leaf page.
**
**     b) If the leaf page no terms, a record indicating how many consecutive
**        leaves contain no terms, and whether or not there is an associated
**        by-rowid index record.
**
**   By definition, there is never more than one type (b) record in a row.
**   Type (b) records only ever appear on height=1 pages - immediate parents
**   of leaves. Only type (a) records are pushed to higher levels.
**
**   Term format:
**
**     * Number of bytes in common with previous term plus 2, as a varint.
**     * Number of bytes of new term data, as a varint.
**     * new term data.
**
**   No-term format:
**
**     * either an 0x00 or 0x01 byte. If the value 0x01 is used, then there 
**       is an associated index-by-rowid record.
**     * the number of zero-term leaves as a varint.
**
** 5. Segment doclist indexes:
**
**   Doclist indexes are themselves b-trees, however they usually consist of
**   a single leaf record only. The format of each doclist index leaf page 
**   is:
**
**     * Flags byte. Bits are:
................................................................................
/*
** Rowids for the averages and structure records in the %_data table.
*/
#define FTS5_AVERAGES_ROWID     1    /* Rowid used for the averages record */
#define FTS5_STRUCTURE_ROWID   10    /* The structure record */

/*
** Macros determining the rowids used by segment nodes. All nodes in all
** segments for all indexes (the regular FTS index and any prefix indexes)
** are stored in the %_data table with large positive rowids.

**
** The %_data table may contain up to (1<<FTS5_SEGMENT_INDEX_BITS) 
** indexes - one regular term index and zero or more prefix indexes.
**

** Each segment in an index has a unique id greater than zero.
**
** Each node in a segment b-tree is assigned a "page number" that is unique
** within nodes of its height within the segment (leaf nodes have a height 
** of 0, parents 1, etc.). Page numbers are allocated sequentially so that
** a nodes page number is always one more than its left sibling.
**
** The rowid for a node is then found using the FTS5_SEGMENT_ROWID() macro
** below. The FTS5_SEGMENT_*_BITS macros define the number of bits used
** to encode the three FTS5_SEGMENT_ROWID() arguments. This module returns
** SQLITE_FULL and fails the current operation if they ever prove too small.
*/
#define FTS5_DATA_ID_B     16     /* Max seg id number 65535 */
#define FTS5_DATA_DLI_B     1     /* Doclist-index flag (1 bit) */
#define FTS5_DATA_HEIGHT_B  5     /* Max b-tree height of 32 */
#define FTS5_DATA_PAGE_B   31     /* Max page number of 2147483648 */

#define fts5_dri(segid, dlidx, height, pgno) (                                 \
 ((i64)(segid)  << (FTS5_DATA_PAGE_B+FTS5_DATA_HEIGHT_B+FTS5_DATA_DLI_B)) +    \
 ((i64)(dlidx)  << (FTS5_DATA_PAGE_B + FTS5_DATA_HEIGHT_B)) +                  \
 ((i64)(height) << (FTS5_DATA_PAGE_B)) +                                       \
 ((i64)(pgno))                                                                 \
)

#define FTS5_SEGMENT_ROWID(segid, height, pgno) fts5_dri(segid, 0, height, pgno)
#define FTS5_DLIDX_ROWID(segid, height, pgno)   fts5_dri(segid, 1, height, pgno)

/*
** Maximum segments permitted in a single index 
*/
#define FTS5_MAX_SEGMENT 2000

#ifdef SQLITE_DEBUG
................................................................................
typedef struct Fts5SegWriter Fts5SegWriter;
typedef struct Fts5Structure Fts5Structure;
typedef struct Fts5StructureLevel Fts5StructureLevel;
typedef struct Fts5StructureSegment Fts5StructureSegment;

struct Fts5Data {
  u8 *p;                          /* Pointer to buffer containing record */
  int n;                          /* Size of record in bytes */

};

/*
** One object per %_data table.
*/
struct Fts5Index {
  Fts5Config *pConfig;            /* Virtual table configuration */
................................................................................
/*
** The contents of the "structure" record for each index are represented
** using an Fts5Structure record in memory. Which uses instances of the 
** other Fts5StructureXXX types as components.
*/
struct Fts5StructureSegment {
  int iSegid;                     /* Segment id */
  int nHeight;                    /* Height of segment b-tree */
  int pgnoFirst;                  /* First leaf page number in segment */
  int pgnoLast;                   /* Last leaf page number in segment */
};
struct Fts5StructureLevel {
  int nMerge;                     /* Number of segments in incr-merge */
  int nSeg;                       /* Total number of segments on level */
  Fts5StructureSegment *aSeg;     /* Array of segments. aSeg[0] is oldest. */
................................................................................
};

/*
** An object of type Fts5SegWriter is used to write to segments.
*/
struct Fts5PageWriter {
  int pgno;                       /* Page number for this page */

  Fts5Buffer buf;                 /* Buffer containing page data */

  Fts5Buffer term;                /* Buffer containing previous term on page */
};
struct Fts5DlidxWriter {
  int pgno;                       /* Page number for this page */
  int bPrevValid;                 /* True if iPrev is valid */
  i64 iPrev;                      /* Previous rowid value written to page */
  Fts5Buffer buf;                 /* Buffer containing page data */
................................................................................
};
struct Fts5SegWriter {
  int iSegid;                     /* Segid to write to */
  Fts5PageWriter writer;          /* PageWriter object */
  i64 iPrevRowid;                 /* Previous rowid written to current leaf */
  u8 bFirstRowidInDoclist;        /* True if next rowid is first in doclist */
  u8 bFirstRowidInPage;           /* True if next rowid is first in page */

  u8 bFirstTermInPage;            /* True if next term will be first in leaf */
  int nLeafWritten;               /* Number of leaf pages written */
  int nEmpty;                     /* Number of contiguous term-less nodes */

  int nDlidx;                     /* Allocated size of aDlidx[] array */
  Fts5DlidxWriter *aDlidx;        /* Array of Fts5DlidxWriter objects */

................................................................................
**
** iRowidOffset/nRowidOffset/aRowidOffset:
**     These are used if the FTS5_SEGITER_REVERSE flag is set.
**
**     For each rowid on the page corresponding to the current term, the
**     corresponding aRowidOffset[] entry is set to the byte offset of the
**     start of the "position-list-size" field within the page.



*/
struct Fts5SegIter {
  Fts5StructureSegment *pSeg;     /* Segment to iterate through */
  int flags;                      /* Mask of configuration flags */
  int iLeafPgno;                  /* Current leaf page number */
  Fts5Data *pLeaf;                /* Current leaf data */
  Fts5Data *pNextLeaf;            /* Leaf page (iLeafPgno+1) */
  int iLeafOffset;                /* Byte offset within current leaf */

  /* The page and offset from which the current term was read. The offset 
  ** is the offset of the first rowid in the current doclist.  */
  int iTermLeafPgno;
  int iTermLeafOffset;




  /* The following are only used if the FTS5_SEGITER_REVERSE flag is set. */
  int iRowidOffset;               /* Current entry in aRowidOffset[] */
  int nRowidOffset;               /* Allocated size of aRowidOffset[] array */
  int *aRowidOffset;              /* Array of offset to rowid fields */

  Fts5DlidxIter *pDlidx;          /* If there is a doclist-index */
................................................................................

  /* Variables populated based on current entry. */
  Fts5Buffer term;                /* Current term */
  i64 iRowid;                     /* Current rowid */
  int nPos;                       /* Number of bytes in current position list */
  int bDel;                       /* True if the delete flag is set */
};









#define FTS5_SEGITER_ONETERM 0x01
#define FTS5_SEGITER_REVERSE 0x02













/*
** poslist:
**   Used by sqlite3Fts5IterPoslist() when the poslist needs to be buffered.
**   There is no way to tell if this is populated or not.
*/
struct Fts5IndexIter {
  Fts5Index *pIndex;              /* Index that owns this iterator */
................................................................................
){
  int nCmp = MIN(nLeft, nRight);
  int res = memcmp(pLeft, pRight, nCmp);
  return (res==0 ? (nLeft - nRight) : res);
}
#endif







/*
** Close the read-only blob handle, if it is open.
*/
static void fts5CloseReader(Fts5Index *p){
  if( p->pReader ){
    sqlite3_blob *pReader = p->pReader;
................................................................................

    if( rc==SQLITE_OK ){
      u8 *aOut = 0;               /* Read blob data into this buffer */
      int nByte = sqlite3_blob_bytes(p->pReader);
      int nAlloc = sizeof(Fts5Data) + nByte + FTS5_DATA_PADDING;
      pRet = (Fts5Data*)sqlite3_malloc(nAlloc);
      if( pRet ){
        pRet->n = nByte;
        aOut = pRet->p = (u8*)&pRet[1];
      }else{
        rc = SQLITE_NOMEM;
      }

      if( rc==SQLITE_OK ){
        rc = sqlite3_blob_read(p->pReader, aOut, nByte, 0);
      }
      if( rc!=SQLITE_OK ){
        sqlite3_free(pRet);
        pRet = 0;



      }
    }
    p->rc = rc;
    p->nRead++;
  }

  assert( (pRet==0)==(p->rc!=SQLITE_OK) );
................................................................................
/*
** INSERT OR REPLACE a record into the %_data table.
*/
static void fts5DataWrite(Fts5Index *p, i64 iRowid, const u8 *pData, int nData){
  if( p->rc!=SQLITE_OK ) return;

  if( p->pWriter==0 ){
    int rc = SQLITE_OK;
    Fts5Config *pConfig = p->pConfig;
    fts5IndexPrepareStmt(p, &p->pWriter, sqlite3_mprintf(
          "REPLACE INTO '%q'.'%q_data'(id, block) VALUES(?,?)", 
          pConfig->zDb, pConfig->zName
    ));
    if( p->rc ) return;
  }
................................................................................
  p->rc = sqlite3_reset(p->pDeleter);
}

/*
** Remove all records associated with segment iSegid.
*/
static void fts5DataRemoveSegment(Fts5Index *p, int iSegid){
  i64 iFirst = FTS5_SEGMENT_ROWID(iSegid, 0, 0);
  i64 iLast = FTS5_SEGMENT_ROWID(iSegid+1, 0, 0)-1;
  fts5DataDelete(p, iFirst, iLast);
  if( p->pIdxDeleter==0 ){
    Fts5Config *pConfig = p->pConfig;
    fts5IndexPrepareStmt(p, &p->pIdxDeleter, sqlite3_mprintf(
          "DELETE FROM '%q'.'%q_idx' WHERE segid=?",
          pConfig->zDb, pConfig->zName
    ));
................................................................................
          nTotal * sizeof(Fts5StructureSegment)
      );

      if( rc==SQLITE_OK ){
        pLvl->nSeg = nTotal;
        for(iSeg=0; iSeg<nTotal; iSeg++){
          i += fts5GetVarint32(&pData[i], pLvl->aSeg[iSeg].iSegid);
          i += fts5GetVarint32(&pData[i], pLvl->aSeg[iSeg].nHeight);
          i += fts5GetVarint32(&pData[i], pLvl->aSeg[iSeg].pgnoFirst);
          i += fts5GetVarint32(&pData[i], pLvl->aSeg[iSeg].pgnoLast);
        }
      }else{
        fts5StructureRelease(pRet);
        pRet = 0;
      }
................................................................................
** is called, it is a no-op.
*/
static Fts5Structure *fts5StructureRead(Fts5Index *p){
  Fts5Config *pConfig = p->pConfig;
  Fts5Structure *pRet = 0;        /* Object to return */
  int iCookie;                    /* Configuration cookie */
  Fts5Data *pData;
  Fts5Buffer buf = {0, 0, 0};

  pData = fts5DataRead(p, FTS5_STRUCTURE_ROWID);
  if( p->rc ) return 0;

  memset(&pData->p[pData->n], 0, FTS5_DATA_PADDING);
  p->rc = fts5StructureDecode(pData->p, pData->n, &iCookie, &pRet);
  if( p->rc==SQLITE_OK && pConfig->iCookie!=iCookie ){
    p->rc = sqlite3Fts5ConfigLoad(pConfig, iCookie);
  }

  fts5DataRelease(pData);
  if( p->rc!=SQLITE_OK ){
    fts5StructureRelease(pRet);
................................................................................
      Fts5StructureLevel *pLvl = &pStruct->aLevel[iLvl];
      fts5BufferAppendVarint(&p->rc, &buf, pLvl->nMerge);
      fts5BufferAppendVarint(&p->rc, &buf, pLvl->nSeg);
      assert( pLvl->nMerge<=pLvl->nSeg );

      for(iSeg=0; iSeg<pLvl->nSeg; iSeg++){
        fts5BufferAppendVarint(&p->rc, &buf, pLvl->aSeg[iSeg].iSegid);
        fts5BufferAppendVarint(&p->rc, &buf, pLvl->aSeg[iSeg].nHeight);
        fts5BufferAppendVarint(&p->rc, &buf, pLvl->aSeg[iSeg].pgnoFirst);
        fts5BufferAppendVarint(&p->rc, &buf, pLvl->aSeg[iSeg].pgnoLast);
      }
    }

    fts5DataWrite(p, FTS5_STRUCTURE_ROWID, buf.p, buf.n);
    fts5BufferFree(&buf);
................................................................................
){
  if( p->rc==SQLITE_OK ){
    int iTst;
    int iPromote = -1;
    int szPromote = 0;            /* Promote anything this size or smaller */
    Fts5StructureSegment *pSeg;   /* Segment just written */
    int szSeg;                    /* Size of segment just written */




    pSeg = &pStruct->aLevel[iLvl].aSeg[pStruct->aLevel[iLvl].nSeg-1];
    szSeg = (1 + pSeg->pgnoLast - pSeg->pgnoFirst);

    /* Check for condition (a) */
    for(iTst=iLvl-1; iTst>=0 && pStruct->aLevel[iTst].nSeg==0; iTst--);
    if( iTst>=0 ){
      int i;
................................................................................
    assert( pLvl->bEof==0 );
    pLvl->iOff = 1;
    pLvl->iOff += fts5GetVarint32(&pData->p[1], pLvl->iLeafPgno);
    pLvl->iOff += fts5GetVarint(&pData->p[pLvl->iOff], (u64*)&pLvl->iRowid);
    pLvl->iFirstOff = pLvl->iOff;
  }else{
    int iOff;
    for(iOff=pLvl->iOff; iOff<pData->n; iOff++){
      if( pData->p[iOff] ) break; 
    }

    if( iOff<pData->n ){
      i64 iVal;
      pLvl->iLeafPgno += (iOff - pLvl->iOff) + 1;
      iOff += fts5GetVarint(&pData->p[iOff], (u64*)&iVal);
      pLvl->iRowid += iVal;
      pLvl->iOff = iOff;
    }else{
      pLvl->bEof = 1;
................................................................................
static i64 fts5DlidxIterRowid(Fts5DlidxIter *pIter){
  return pIter->aLvl[0].iRowid;
}
static int fts5DlidxIterPgno(Fts5DlidxIter *pIter){
  return pIter->aLvl[0].iLeafPgno;
}

static void fts5LeafHeader(Fts5Data *pLeaf, int *piRowid, int *piTerm){
  *piRowid = (int)fts5GetU16(&pLeaf->p[0]);
  *piTerm = (int)fts5GetU16(&pLeaf->p[2]);
}

/*
** Load the next leaf page into the segment iterator.
*/
static void fts5SegIterNextPage(
  Fts5Index *p,                   /* FTS5 backend object */
  Fts5SegIter *pIter              /* Iterator to advance to next page */
){

  Fts5StructureSegment *pSeg = pIter->pSeg;
  fts5DataRelease(pIter->pLeaf);
  pIter->iLeafPgno++;
  if( pIter->pNextLeaf ){
    assert( pIter->iLeafPgno<=pSeg->pgnoLast );
    pIter->pLeaf = pIter->pNextLeaf;
    pIter->pNextLeaf = 0;
  }else if( pIter->iLeafPgno<=pSeg->pgnoLast ){
    pIter->pLeaf = fts5DataRead(p, 
        FTS5_SEGMENT_ROWID(pSeg->iSegid, 0, pIter->iLeafPgno)
    );
  }else{
    pIter->pLeaf = 0;












  }
}

/*
** Argument p points to a buffer containing a varint to be interpreted as a
** position list size field. Read the varint and return the number of bytes
** read. Before returning, set *pnSz to the number of bytes in the position
................................................................................
**
** Leave Fts5SegIter.iLeafOffset pointing to the first byte of the 
** position list content (if any).
*/
static void fts5SegIterLoadNPos(Fts5Index *p, Fts5SegIter *pIter){
  if( p->rc==SQLITE_OK ){
    int iOff = pIter->iLeafOffset;  /* Offset to read at */

    if( iOff>=pIter->pLeaf->n ){
      p->rc = FTS5_CORRUPT;
    }else{
      const u8 *a = &pIter->pLeaf->p[iOff];
      pIter->iLeafOffset += fts5GetPoslistSize(a, &pIter->nPos, &pIter->bDel);
    }
  }
}

static void fts5SegIterLoadRowid(Fts5Index *p, Fts5SegIter *pIter){
  u8 *a = pIter->pLeaf->p;        /* Buffer to read data from */
  int iOff = pIter->iLeafOffset;


  if( iOff>=pIter->pLeaf->n ){
    fts5SegIterNextPage(p, pIter);
    if( pIter->pLeaf==0 ){
      if( p->rc==SQLITE_OK ) p->rc = FTS5_CORRUPT;
      return;
    }
    iOff = 4;
    a = pIter->pLeaf->p;
................................................................................
  iOff += fts5GetVarint32(&a[iOff], nNew);
  pIter->term.n = nKeep;
  fts5BufferAppendBlob(&p->rc, &pIter->term, nNew, &a[iOff]);
  iOff += nNew;
  pIter->iTermLeafOffset = iOff;
  pIter->iTermLeafPgno = pIter->iLeafPgno;
  pIter->iLeafOffset = iOff;









  fts5SegIterLoadRowid(p, pIter);
}

/*
** Initialize the iterator object pIter to iterate through the entries in
** segment pSeg. The iterator is left pointing to the first entry when 
................................................................................
    memset(pIter, 0, sizeof(*pIter));
    pIter->pSeg = pSeg;
    pIter->iLeafPgno = pSeg->pgnoFirst-1;
    fts5SegIterNextPage(p, pIter);
  }

  if( p->rc==SQLITE_OK ){
    u8 *a = pIter->pLeaf->p;
    pIter->iLeafOffset = fts5GetU16(&a[2]);



    fts5SegIterLoadTerm(p, pIter, 0);
    fts5SegIterLoadNPos(p, pIter);
  }
}

/*
** This function is only ever called on iterators created by calls to
................................................................................
** This function advances the iterator so that it points to the last 
** relevant rowid on the page and, if necessary, initializes the 
** aRowidOffset[] and iRowidOffset variables. At this point the iterator
** is in its regular state - Fts5SegIter.iLeafOffset points to the first
** byte of the position list content associated with said rowid.
*/
static void fts5SegIterReverseInitPage(Fts5Index *p, Fts5SegIter *pIter){
  int n = pIter->pLeaf->n;
  int i = pIter->iLeafOffset;
  u8 *a = pIter->pLeaf->p;
  int iRowidOffset = 0;






  while( 1 ){
    i64 iDelta = 0;
    int nPos;
    int bDummy;

    i += fts5GetPoslistSize(&a[i], &nPos, &bDummy);
    i += nPos;
    if( i>=n ) break;
    i += fts5GetVarint(&a[i], (u64*)&iDelta);
    if( iDelta==0 ) break;
    pIter->iRowid += iDelta;

    if( iRowidOffset>=pIter->nRowidOffset ){
      int nNew = pIter->nRowidOffset + 8;
      int *aNew = (int*)sqlite3_realloc(pIter->aRowidOffset, nNew*sizeof(int));
      if( aNew==0 ){
        p->rc = SQLITE_NOMEM;
................................................................................

  fts5DataRelease(pIter->pLeaf);
  pIter->pLeaf = 0;
  while( p->rc==SQLITE_OK && pIter->iLeafPgno>pIter->iTermLeafPgno ){
    Fts5Data *pNew;
    pIter->iLeafPgno--;
    pNew = fts5DataRead(p, FTS5_SEGMENT_ROWID(
          pIter->pSeg->iSegid, 0, pIter->iLeafPgno
    ));
    if( pNew ){



      if( pIter->iLeafPgno==pIter->iTermLeafPgno ){
        if( pIter->iTermLeafOffset<pNew->n ){

          pIter->pLeaf = pNew;
          pIter->iLeafOffset = pIter->iTermLeafOffset;
        }
      }else{
        int iRowidOff, dummy;
        fts5LeafHeader(pNew, &iRowidOff, &dummy);

        if( iRowidOff ){
          pIter->pLeaf = pNew;
          pIter->iLeafOffset = iRowidOff;
        }
      }

      if( pIter->pLeaf ){
................................................................................
      }else{
        fts5DataRelease(pNew);
      }
    }
  }

  if( pIter->pLeaf ){

    fts5SegIterReverseInitPage(p, pIter);
  }
}

/*
** Return true if the iterator passed as the second argument currently
** points to a delete marker. A delete marker is an entry with a 0 byte
................................................................................
      Fts5Data *pLeaf = pIter->pLeaf;
      int iOff;
      int bNewTerm = 0;
      int nKeep = 0;

      /* Search for the end of the position list within the current page. */
      u8 *a = pLeaf->p;
      int n = pLeaf->n;


      iOff = pIter->iLeafOffset + pIter->nPos;

      if( iOff<n ){
        /* The next entry is on the current page */
        u64 iDelta;
        iOff += sqlite3Fts5GetVarint(&a[iOff], &iDelta);
        pIter->iLeafOffset = iOff;
        if( iDelta==0 ){
          bNewTerm = 1;
          if( iOff>=n ){
            fts5SegIterNextPage(p, pIter);
            pIter->iLeafOffset = 4;
          }else if( iOff!=fts5GetU16(&a[2]) ){
            pIter->iLeafOffset += fts5GetVarint32(&a[iOff], nKeep);
          }
        }else{


          pIter->iRowid += iDelta;

        }


      }else if( pIter->pSeg==0 ){
        const u8 *pList = 0;
        const char *zTerm = 0;
        int nList = 0;
        if( 0==(pIter->flags & FTS5_SEGITER_ONETERM) ){
          sqlite3Fts5HashScanNext(p->pHash);
          sqlite3Fts5HashScanEntry(p->pHash, &zTerm, &pList, &nList);
        }
        if( pList==0 ){
          fts5DataRelease(pIter->pLeaf);
          pIter->pLeaf = 0;
        }else{
          pIter->pLeaf->p = (u8*)pList;
          pIter->pLeaf->n = nList;


          sqlite3Fts5BufferSet(&p->rc, &pIter->term, strlen(zTerm), (u8*)zTerm);
          pIter->iLeafOffset = fts5GetVarint(pList, (u64*)&pIter->iRowid);
        }
      }else{
        iOff = 0;
        /* Next entry is not on the current page */
        while( iOff==0 ){
          fts5SegIterNextPage(p, pIter);
          pLeaf = pIter->pLeaf;
          if( pLeaf==0 ) break;
          if( (iOff = fts5GetU16(&pLeaf->p[0])) && iOff<pLeaf->n ){

            iOff += sqlite3Fts5GetVarint(&pLeaf->p[iOff], (u64*)&pIter->iRowid);
            pIter->iLeafOffset = iOff;
          }
          else if( (iOff = fts5GetU16(&pLeaf->p[2])) ){











            pIter->iLeafOffset = iOff;

            bNewTerm = 1;
          }
          if( iOff>=pLeaf->n ){
            p->rc = FTS5_CORRUPT;
            return;
          }
        }
      }

      /* Check if the iterator is now at EOF. If so, return early. */
................................................................................
  Fts5DlidxIter *pDlidx = pIter->pDlidx;
  Fts5Data *pLast = 0;
  int pgnoLast = 0;

  if( pDlidx ){
    int iSegid = pIter->pSeg->iSegid;
    pgnoLast = fts5DlidxIterPgno(pDlidx);
    pLast = fts5DataRead(p, FTS5_SEGMENT_ROWID(iSegid, 0, pgnoLast));
  }else{
    int iOff;                               /* Byte offset within pLeaf */
    Fts5Data *pLeaf = pIter->pLeaf;         /* Current leaf data */

    /* Currently, Fts5SegIter.iLeafOffset (and iOff) points to the first 
    ** byte of position-list content for the current rowid. Back it up
    ** so that it points to the start of the position-list size field. */
    pIter->iLeafOffset -= sqlite3Fts5GetVarintLen(pIter->nPos*2+pIter->bDel);
    iOff = pIter->iLeafOffset;
    assert( iOff>=4 );

    /* Search for a new term within the current leaf. If one can be found,
    ** then this page contains the largest rowid for the current term. */
    while( iOff<pLeaf->n ){
      int nPos;
      i64 iDelta;
      int bDummy;

      /* Read the position-list size field */
      iOff += fts5GetPoslistSize(&pLeaf->p[iOff], &nPos, &bDummy);
      iOff += nPos;
      if( iOff>=pLeaf->n ) break;

      /* Rowid delta. Or, if 0x00, the end of doclist marker. */
      nPos = fts5GetVarint(&pLeaf->p[iOff], (u64*)&iDelta);
      if( iDelta==0 ) break;
      iOff += nPos;
    }

    /* If this condition is true then the largest rowid for the current
    ** term may not be stored on the current page. So search forward to
    ** see where said rowid really is.  */
    if( iOff>=pLeaf->n ){
      int pgno;
      Fts5StructureSegment *pSeg = pIter->pSeg;

      /* The last rowid in the doclist may not be on the current page. Search
      ** forward to find the page containing the last rowid.  */
      for(pgno=pIter->iLeafPgno+1; !p->rc && pgno<=pSeg->pgnoLast; pgno++){
        i64 iAbs = FTS5_SEGMENT_ROWID(pSeg->iSegid, 0, pgno);
        Fts5Data *pNew = fts5DataRead(p, iAbs);
        if( pNew ){
          int iRowid, iTerm;
          fts5LeafHeader(pNew, &iRowid, &iTerm);

          if( iRowid ){
            SWAPVAL(Fts5Data*, pNew, pLast);
            pgnoLast = pgno;
          }
          fts5DataRelease(pNew);
          if( iTerm ) break;
        }
      }
    }
  }

  /* If pLast is NULL at this point, then the last rowid for this doclist
  ** lies on the page currently indicated by the iterator. In this case 
................................................................................
  ** field associated with the first relevant rowid on the page.
  **
  ** Or, if pLast is non-NULL, then it is the page that contains the last
  ** rowid. In this case configure the iterator so that it points to the
  ** first rowid on this page.
  */
  if( pLast ){
    int dummy;
    int iOff;
    fts5DataRelease(pIter->pLeaf);
    pIter->pLeaf = pLast;
    pIter->iLeafPgno = pgnoLast;
    fts5LeafHeader(pLast, &iOff, &dummy);
    iOff += fts5GetVarint(&pLast->p[iOff], (u64*)&pIter->iRowid);
    pIter->iLeafOffset = iOff;







  }

  fts5SegIterReverseInitPage(p, pIter);
}

/*
** Iterator pIter currently points to the first rowid of a doclist.
................................................................................

  assert( pIter->flags & FTS5_SEGITER_ONETERM );
  assert( pIter->pDlidx==0 );

  /* Check if the current doclist ends on this page. If it does, return
  ** early without loading the doclist-index (as it belongs to a different
  ** term. */
  if( pIter->iTermLeafPgno==pIter->iLeafPgno ){
    int iOff = pIter->iLeafOffset + pIter->nPos;
    while( iOff<pLeaf->n ){
      int bDummy;
      int nPos;
      i64 iDelta;

      /* iOff is currently the offset of the start of position list data */
      iOff += fts5GetVarint(&pLeaf->p[iOff], (u64*)&iDelta);
      if( iDelta==0 ) return;
      assert_nc( iOff<pLeaf->n );
      iOff += fts5GetPoslistSize(&pLeaf->p[iOff], &nPos, &bDummy);
      iOff += nPos;
    }
  }

  pIter->pDlidx = fts5DlidxIterInit(p, bRev, iSeg, pIter->iTermLeafPgno);
}

#define fts5IndexGetVarint32(a, iOff, nVal) {     \
  nVal = a[iOff++];                               \
  if( nVal & 0x80 ){                              \
    iOff--;                                       \
    iOff += fts5GetVarint32(&a[iOff], nVal);      \
  }                                               \
}

#define fts5IndexSkipVarint(a, iOff) {            \
  int iEnd = iOff+9;                              \
  while( (a[iOff++] & 0x80) && iOff<iEnd );       \
}
................................................................................
  Fts5Index *p,                   /* Leave any error code here */
  int bGe,                        /* True for a >= search */
  Fts5SegIter *pIter,             /* Iterator to seek */
  const u8 *pTerm, int nTerm      /* Term to search for */
){
  int iOff;
  const u8 *a = pIter->pLeaf->p;

  int n = pIter->pLeaf->n;

  int nMatch = 0;
  int nKeep = 0;
  int nNew = 0;




  assert( p->rc==SQLITE_OK );
  assert( pIter->pLeaf );

  iOff = fts5GetU16(&a[2]);
  if( iOff<4 || iOff>=n ){
    p->rc = FTS5_CORRUPT;
    return;

  }

  while( 1 ){
    int i;
    int nCmp;

    /* Figure out how many new bytes are in this term */
    fts5IndexGetVarint32(a, iOff, nNew);

    if( nKeep<nMatch ){
      goto search_failed;
    }

    assert( nKeep>=nMatch );
    if( nKeep==nMatch ){


      nCmp = MIN(nNew, nTerm-nMatch);
      for(i=0; i<nCmp; i++){
        if( a[iOff+i]!=pTerm[nMatch+i] ) break;
      }
      nMatch += i;

      if( nTerm==nMatch ){
................................................................................
        }else{
          goto search_failed;
        }
      }else if( i<nNew && a[iOff+i]>pTerm[nMatch] ){
        goto search_failed;
      }
    }
    iOff += nNew;


    /* Skip past the doclist. If the end of the page is reached, bail out. */
    while( 1 ){
      int nPos;

      /* Skip past rowid delta */
      fts5IndexSkipVarint(a, iOff);

      /* Skip past position list */
      fts5IndexGetVarint32(a, iOff, nPos);

      iOff += (nPos >> 1);
      if( iOff>=(n-1) ){
        iOff = n;
        goto search_failed;
      }

      /* If this is the end of the doclist, break out of the loop */
      if( a[iOff]==0x00 ){
        iOff++;
        break;
      }
    };

    /* Read the nKeep field of the next term. */
    fts5IndexGetVarint32(a, iOff, nKeep);
  }

 search_failed:
  if( bGe==0 ){
    fts5DataRelease(pIter->pLeaf);
    pIter->pLeaf = 0;
    return;
  }else if( iOff>=n ){
    do {
      fts5SegIterNextPage(p, pIter);
      if( pIter->pLeaf==0 ) return;
      a = pIter->pLeaf->p;
      iOff = fts5GetU16(&a[2]);
      if( iOff ){
        if( iOff<4 || iOff>=n ){
          p->rc = FTS5_CORRUPT;
        }else{
          nKeep = 0;
          iOff += fts5GetVarint32(&a[iOff], nNew);
          break;
        }
      }
    }while( 1 );
  }

 search_success:

  pIter->iLeafOffset = iOff + nNew;
  pIter->iTermLeafOffset = pIter->iLeafOffset;
  pIter->iTermLeafPgno = pIter->iLeafPgno;

  fts5BufferSet(&p->rc, &pIter->term, nKeep, pTerm);
  fts5BufferAppendBlob(&p->rc, &pIter->term, nNew, &a[iOff]);










  fts5SegIterLoadRowid(p, pIter);
  fts5SegIterLoadNPos(p, pIter);
}

/*
** Initialize the object pIter to point to term pTerm/nTerm within segment
** pSeg. If there is no such term in the index, the iterator is set to EOF.
................................................................................

  if( pList ){
    Fts5Data *pLeaf;
    sqlite3Fts5BufferSet(&p->rc, &pIter->term, n, z);
    pLeaf = fts5IdxMalloc(p, sizeof(Fts5Data));
    if( pLeaf==0 ) return;
    pLeaf->p = (u8*)pList;
    pLeaf->n = nList;
    pIter->pLeaf = pLeaf;
    pIter->iLeafOffset = fts5GetVarint(pLeaf->p, (u64*)&pIter->iRowid);


    if( flags & FTS5INDEX_QUERY_DESC ){
      pIter->flags |= FTS5_SEGITER_REVERSE;
      fts5SegIterReverseInitPage(p, pIter);
    }else{
      fts5SegIterLoadNPos(p, pIter);
    }
................................................................................
    pIter->iLeafPgno = iLeafPgno-1;
    fts5SegIterNextPage(p, pIter);
    assert( p->rc!=SQLITE_OK || pIter->iLeafPgno==iLeafPgno );

    if( p->rc==SQLITE_OK ){
      int iOff;
      u8 *a = pIter->pLeaf->p;
      int n = pIter->pLeaf->n;

      iOff = fts5GetU16(&a[0]);
      if( iOff<4 || iOff>=n ){
        p->rc = FTS5_CORRUPT;
      }else{
        iOff += fts5GetVarint(&a[iOff], (u64*)&pIter->iRowid);
        pIter->iLeafOffset = iOff;
        fts5SegIterLoadNPos(p, pIter);
      }
................................................................................
){
  Fts5IndexIter *pNew;
  pNew = fts5MultiIterAlloc(p, 2);
  if( pNew ){
    Fts5SegIter *pIter = &pNew->aSeg[1];

    pIter->flags = FTS5_SEGITER_ONETERM;
    if( pData->n>0 ){
      pIter->pLeaf = pData;
      pIter->iLeafOffset = fts5GetVarint(pData->p, (u64*)&pIter->iRowid);

      pNew->aFirst[1].iFirst = 1;
      if( bDesc ){
        pNew->bRev = 1;
        pIter->flags |= FTS5_SEGITER_REVERSE;
        fts5SegIterReverseInitPage(p, pIter);
      }else{
        fts5SegIterLoadNPos(p, pIter);
................................................................................
  Fts5SegIter *pSeg,              /* Poslist of this iterator */
  void *pCtx,                     /* Context pointer for xChunk callback */
  void (*xChunk)(Fts5Index*, void*, const u8*, int)
){
  int nRem = pSeg->nPos;          /* Number of bytes still to come */
  Fts5Data *pData = 0;
  u8 *pChunk = &pSeg->pLeaf->p[pSeg->iLeafOffset];
  int nChunk = MIN(nRem, pSeg->pLeaf->n - pSeg->iLeafOffset);
  int pgno = pSeg->iLeafPgno;
  int pgnoSave = 0;

  if( (pSeg->flags & FTS5_SEGITER_REVERSE)==0 ){
    pgnoSave = pgno+1;
  }

................................................................................
    xChunk(p, pCtx, pChunk, nChunk);
    nRem -= nChunk;
    fts5DataRelease(pData);
    if( nRem<=0 ){
      break;
    }else{
      pgno++;
      pData = fts5DataRead(p, FTS5_SEGMENT_ROWID(pSeg->pSeg->iSegid, 0, pgno));
      if( pData==0 ) break;
      pChunk = &pData->p[4];
      nChunk = MIN(nRem, pData->n - 4);
      if( pgno==pgnoSave ){
        assert( pSeg->pNextLeaf==0 );
        pSeg->pNextLeaf = pData;
        pData = 0;
      }
    }
  }
................................................................................
}

static void fts5WriteFlushLeaf(Fts5Index *p, Fts5SegWriter *pWriter){
  static const u8 zero[] = { 0x00, 0x00, 0x00, 0x00 };
  Fts5PageWriter *pPage = &pWriter->writer;
  i64 iRowid;







  if( pWriter->bFirstTermInPage ){
    /* No term was written to this page. */
    assert( 0==fts5GetU16(&pPage->buf.p[2]) );

    fts5WriteBtreeNoTerm(p, pWriter);



  }

  /* Write the current page to the db. */
  iRowid = FTS5_SEGMENT_ROWID(pWriter->iSegid, 0, pPage->pgno);
  fts5DataWrite(p, iRowid, pPage->buf.p, pPage->buf.n);

  /* Initialize the next page. */
  fts5BufferZero(&pPage->buf);

  fts5BufferAppendBlob(&p->rc, &pPage->buf, 4, zero);

  pPage->pgno++;

  /* Increase the leaves written counter */
  pWriter->nLeafWritten++;

  /* The new leaf holds no terms or rowids */
  pWriter->bFirstTermInPage = 1;
................................................................................
static void fts5WriteAppendTerm(
  Fts5Index *p, 
  Fts5SegWriter *pWriter,
  int nTerm, const u8 *pTerm 
){
  int nPrefix;                    /* Bytes of prefix compression for term */
  Fts5PageWriter *pPage = &pWriter->writer;

  assert( pPage->buf.n==0 || pPage->buf.n>4 );
  if( pPage->buf.n==0 ){
    /* Zero the first term and first rowid fields */
    static const u8 zero[] = { 0x00, 0x00, 0x00, 0x00 };
    fts5BufferAppendBlob(&p->rc, &pPage->buf, 4, zero);
    assert( pWriter->bFirstTermInPage );
  }
  if( p->rc ) return;
  
  if( pWriter->bFirstTermInPage ){
    /* Update the "first term" field of the page header. */
    assert( pPage->buf.p[2]==0 && pPage->buf.p[3]==0 );
    fts5PutU16(&pPage->buf.p[2], pPage->buf.n);











    nPrefix = 0;
    if( pPage->pgno!=1 ){
      /* This is the first term on a leaf that is not the leftmost leaf in
      ** the segment b-tree. In this case it is necessary to add a term to
      ** the b-tree hierarchy that is (a) larger than the largest term 
      ** already written to the segment and (b) smaller than or equal to
      ** this term. In other words, a prefix of (pTerm/nTerm) that is one
................................................................................
  pWriter->bFirstTermInPage = 0;

  pWriter->bFirstRowidInPage = 0;
  pWriter->bFirstRowidInDoclist = 1;

  assert( p->rc || (pWriter->nDlidx>0 && pWriter->aDlidx[0].buf.n==0) );
  pWriter->aDlidx[0].pgno = pPage->pgno;

  /* If the current leaf page is full, flush it to disk. */
  if( pPage->buf.n>=p->pConfig->pgsz ){
    fts5WriteFlushLeaf(p, pWriter);
  }
}

/*
** Append a rowid and position-list size field to the writers output. 
*/
static void fts5WriteAppendRowid(
  Fts5Index *p, 
  Fts5SegWriter *pWriter,
  i64 iRowid,
  int nPos
){
  if( p->rc==SQLITE_OK ){
    Fts5PageWriter *pPage = &pWriter->writer;





    /* If this is to be the first rowid written to the page, set the 
    ** rowid-pointer in the page-header. Also append a value to the dlidx
    ** buffer, in case a doclist-index is required.  */
    if( pWriter->bFirstRowidInPage ){
      fts5PutU16(pPage->buf.p, pPage->buf.n);
      fts5WriteDlidxAppend(p, pWriter, iRowid);
................................................................................
      fts5BufferAppendVarint(&p->rc, &pPage->buf, iRowid - pWriter->iPrevRowid);
    }
    pWriter->iPrevRowid = iRowid;
    pWriter->bFirstRowidInDoclist = 0;
    pWriter->bFirstRowidInPage = 0;

    fts5BufferAppendVarint(&p->rc, &pPage->buf, nPos);

    if( pPage->buf.n>=p->pConfig->pgsz ){
      fts5WriteFlushLeaf(p, pWriter);
    }
  }
}

static void fts5WriteAppendPoslistData(
  Fts5Index *p, 
  Fts5SegWriter *pWriter, 
  const u8 *aData, 
................................................................................
  int nData
){
  Fts5PageWriter *pPage = &pWriter->writer;
  const u8 *a = aData;
  int n = nData;
  
  assert( p->pConfig->pgsz>0 );
  while( p->rc==SQLITE_OK && (pPage->buf.n + n)>=p->pConfig->pgsz ){


    int nReq = p->pConfig->pgsz - pPage->buf.n;
    int nCopy = 0;
    while( nCopy<nReq ){
      i64 dummy;
      nCopy += fts5GetVarint(&a[nCopy], (u64*)&dummy);
    }
    fts5BufferAppendBlob(&p->rc, &pPage->buf, nCopy, a);
    a += nCopy;
................................................................................
    fts5WriteFlushLeaf(p, pWriter);
  }
  if( n>0 ){
    fts5BufferAppendBlob(&p->rc, &pPage->buf, n, a);
  }
}

static void fts5WriteAppendZerobyte(Fts5Index *p, Fts5SegWriter *pWriter){
  fts5BufferAppendVarint(&p->rc, &pWriter->writer.buf, 0);
}

/*
** Flush any data cached by the writer object to the database. Free any
** allocations associated with the writer.
*/
static void fts5WriteFinish(
  Fts5Index *p, 
  Fts5SegWriter *pWriter,         /* Writer object */
  int *pnHeight,                  /* OUT: Height of the b-tree */
  int *pnLeaf                     /* OUT: Number of leaf pages in b-tree */
){
  int i;
  Fts5PageWriter *pLeaf = &pWriter->writer;
  if( p->rc==SQLITE_OK ){
    if( pLeaf->pgno==1 && pLeaf->buf.n==0 ){
      *pnLeaf = 0;
      *pnHeight = 0;
    }else{
      if( pLeaf->buf.n>4 ){
        fts5WriteFlushLeaf(p, pWriter);
      }
      *pnLeaf = pLeaf->pgno-1;

      fts5WriteFlushBtree(p, pWriter);
      *pnHeight = 0;
    }
  }
  fts5BufferFree(&pLeaf->term);
  fts5BufferFree(&pLeaf->buf);

  fts5BufferFree(&pWriter->btterm);

  for(i=0; i<pWriter->nDlidx; i++){
    sqlite3Fts5BufferFree(&pWriter->aDlidx[i].buf);
  }
  sqlite3_free(pWriter->aDlidx);
}

static void fts5WriteInit(
  Fts5Index *p, 
  Fts5SegWriter *pWriter, 
  int iSegid
){


  memset(pWriter, 0, sizeof(Fts5SegWriter));
  pWriter->iSegid = iSegid;

  fts5WriteDlidxGrow(p, pWriter, 1);
  pWriter->writer.pgno = 1;
  pWriter->bFirstTermInPage = 1;
  pWriter->iBtPage = 1;





  if( p->pIdxWriter==0 ){
    Fts5Config *pConfig = p->pConfig;
    fts5IndexPrepareStmt(p, &p->pIdxWriter, sqlite3_mprintf(
          "INSERT INTO '%q'.'%q_idx'(segid,term,pgno) VALUES(?,?,?)", 
          pConfig->zDb, pConfig->zName
    ));
  }

  if( p->rc==SQLITE_OK ){







    sqlite3_bind_int(p->pIdxWriter, 1, pWriter->iSegid);
  }
}

/*
** Iterator pIter was used to iterate through the input segments of on an
** incremental merge operation. This function is called if the incremental
................................................................................
      pSeg->pSeg->pgnoLast = 0;
      pSeg->pSeg->pgnoFirst = 0;
    }else{
      int iOff = pSeg->iTermLeafOffset;     /* Offset on new first leaf page */
      i64 iLeafRowid;
      Fts5Data *pData;
      int iId = pSeg->pSeg->iSegid;
      u8 aHdr[4] = {0x00, 0x00, 0x00, 0x04};

      iLeafRowid = FTS5_SEGMENT_ROWID(iId, 0, pSeg->iTermLeafPgno);
      pData = fts5DataRead(p, iLeafRowid);
      if( pData ){
        fts5BufferZero(&buf);

        fts5BufferAppendBlob(&p->rc, &buf, sizeof(aHdr), aHdr);
        fts5BufferAppendVarint(&p->rc, &buf, pSeg->term.n);
        fts5BufferAppendBlob(&p->rc, &buf, pSeg->term.n, pSeg->term.p);













        fts5BufferAppendBlob(&p->rc, &buf, pData->n - iOff, &pData->p[iOff]);




        fts5DataRelease(pData);
        pSeg->pSeg->pgnoFirst = pSeg->iTermLeafPgno;
        fts5DataDelete(p, FTS5_SEGMENT_ROWID(iId, 0, 1), iLeafRowid);
        fts5DataWrite(p, iLeafRowid, buf.p, buf.n);
      }
    }
  }
  fts5BufferFree(&buf);
}

................................................................................
  Fts5StructureLevel *pLvlOut;
  Fts5IndexIter *pIter = 0;       /* Iterator to read input data */
  int nRem = pnRem ? *pnRem : 0;  /* Output leaf pages left to write */
  int nInput;                     /* Number of input segments */
  Fts5SegWriter writer;           /* Writer object */
  Fts5StructureSegment *pSeg;     /* Output segment */
  Fts5Buffer term;
  int bRequireDoclistTerm = 0;    /* Doclist terminator (0x00) required */
  int bOldest;                    /* True if the output segment is the oldest */

  assert( iLvl<pStruct->nLevel );
  assert( pLvl->nMerge<=pLvl->nSeg );

  memset(&writer, 0, sizeof(Fts5SegWriter));
  memset(&term, 0, sizeof(Fts5Buffer));
................................................................................
    pTerm = fts5MultiIterTerm(pIter, &nTerm);
    if( nTerm!=term.n || memcmp(pTerm, term.p, nTerm) ){
      if( pnRem && writer.nLeafWritten>nRem ){
        break;
      }

      /* This is a new term. Append a term to the output segment. */
      if( bRequireDoclistTerm ){
        fts5WriteAppendZerobyte(p, &writer);
      }
      fts5WriteAppendTerm(p, &writer, nTerm, pTerm);
      fts5BufferSet(&p->rc, &term, nTerm, pTerm);
      bRequireDoclistTerm = 1;
    }

    /* Append the rowid to the output */
    /* WRITEPOSLISTSIZE */
    nPos = pSegIter->nPos*2 + pSegIter->bDel;
    fts5WriteAppendRowid(p, &writer, fts5MultiIterRowid(pIter), nPos);

    /* Append the position-list data to the output */
    fts5ChunkIterate(p, pSegIter, (void*)&writer, fts5MergeChunkCallback);
  }

  /* Flush the last leaf page to disk. Set the output segment b-tree height
  ** and last leaf page number at the same time.  */
  fts5WriteFinish(p, &writer, &pSeg->nHeight, &pSeg->pgnoLast);

  if( fts5MultiIterEof(p, pIter) ){
    int i;

    /* Remove the redundant segments from the %_data table */
    for(i=0; i<nInput; i++){
      fts5DataRemoveSegment(p, pLvl->aSeg[i].iSegid);
................................................................................
  const int nCrisis = p->pConfig->nCrisisMerge;
  Fts5Structure *pStruct = *ppStruct;
  int iLvl = 0;

  assert( p->rc!=SQLITE_OK || pStruct->nLevel>0 );
  while( p->rc==SQLITE_OK && pStruct->aLevel[iLvl].nSeg>=nCrisis ){
    fts5IndexMergeLevel(p, &pStruct, iLvl, 0);

    fts5StructurePromote(p, iLvl+1, pStruct);
    iLvl++;
  }
  *ppStruct = pStruct;
}

static int fts5IndexReturn(Fts5Index *p){
................................................................................
** in a 32-bit integer. Return the size of the largest prefix of this 
** list nMax bytes or less in size.
*/
static int fts5PoslistPrefix(const u8 *aBuf, int nMax){
  int ret;
  u32 dummy;
  ret = fts5GetVarint32(aBuf, dummy);

  while( 1 ){
    int i = fts5GetVarint32(&aBuf[ret], dummy);
    if( (ret + i) > nMax ) break;
    ret += i;

  }
  return ret;
}

#define fts5BufferSafeAppendBlob(pBuf, pBlob, nBlob) { \
  assert( pBuf->nSpace>=(pBuf->n+nBlob) );             \
  memcpy(&pBuf->p[pBuf->n], pBlob, nBlob);             \
................................................................................
  pStruct = fts5StructureRead(p);
  iSegid = fts5AllocateSegid(p, pStruct);

  if( iSegid ){
    const int pgsz = p->pConfig->pgsz;

    Fts5StructureSegment *pSeg;   /* New segment within pStruct */
    int nHeight;                  /* Height of new segment b-tree */
    Fts5Buffer *pBuf;             /* Buffer in which to assemble leaf page */
    const u8 *zPrev = 0;


    Fts5SegWriter writer;
    fts5WriteInit(p, &writer, iSegid);

    /* Pre-allocate the buffer used to assemble leaf pages to the target
    ** page size.  */
    assert( pgsz>0 );
    pBuf = &writer.writer.buf;
    fts5BufferGrow(&p->rc, pBuf, pgsz + 20);



    /* Begin scanning through hash table entries. This loop runs once for each
    ** term/doclist currently stored within the hash table. */
    if( p->rc==SQLITE_OK ){
      memset(pBuf->p, 0, 4);
      pBuf->n = 4;
      p->rc = sqlite3Fts5HashScanInit(pHash, 0, 0);
    }
    while( p->rc==SQLITE_OK && 0==sqlite3Fts5HashScanEof(pHash) ){
      const char *zTerm;          /* Buffer containing term */
      int nTerm;                  /* Size of zTerm in bytes */
      const u8 *pDoclist;         /* Pointer to doclist for this term */
      int nDoclist;               /* Size of doclist in bytes */
      int nSuffix;                /* Size of term suffix */


      sqlite3Fts5HashScanEntry(pHash, &zTerm, &pDoclist, &nDoclist);
      nTerm = strlen(zTerm);


      /* Decide if the term will fit on the current leaf. If it will not, 
      ** flush the leaf to disk here.  */
      if( pBuf->n>4 && (pBuf->n + nTerm + 2) > pgsz ){
        fts5WriteFlushLeaf(p, &writer);
        pBuf = &writer.writer.buf;
        if( (nTerm + 32) > pBuf->nSpace ){
          fts5BufferGrow(&p->rc, pBuf, nTerm + 32 - pBuf->n);
          if( p->rc ) break;
        }
      }

      /* Write the term to the leaf. And if it is the first on the leaf, and
      ** the leaf is not page number 1, push it up into the b-tree hierarchy 
      ** as well.  */
      if( writer.bFirstTermInPage==0 ){
        int nPre = fts5PrefixCompress(nTerm, zPrev, nTerm, (const u8*)zTerm);
        pBuf->n += sqlite3Fts5PutVarint(&pBuf->p[pBuf->n], nPre);
        nSuffix = nTerm - nPre;
      }else{
        fts5PutU16(&pBuf->p[2], pBuf->n);
        writer.bFirstTermInPage = 0;
        if( writer.writer.pgno!=1 ){
          int nPre = fts5PrefixCompress(nTerm, zPrev, nTerm, (const u8*)zTerm);
          fts5WriteBtreeTerm(p, &writer, nPre+1, (const u8*)zTerm);
          pBuf = &writer.writer.buf;
          assert( nPre<nTerm );
        }
        nSuffix = nTerm;
      }
      pBuf->n += sqlite3Fts5PutVarint(&pBuf->p[pBuf->n], nSuffix);
      fts5BufferSafeAppendBlob(pBuf, (const u8*)&zTerm[nTerm-nSuffix], nSuffix);

      /* We just wrote a term into page writer.aWriter[0].pgno. If a 
      ** doclist-index is to be generated for this doclist, it will be
      ** associated with this page. */
      assert( writer.nDlidx>0 && writer.aDlidx[0].buf.n==0 );
      writer.aDlidx[0].pgno = writer.writer.pgno;

      if( pgsz>=(pBuf->n + nDoclist + 1) ){
        /* The entire doclist will fit on the current leaf. */
        fts5BufferSafeAppendBlob(pBuf, pDoclist, nDoclist);
      }else{
        i64 iRowid = 0;
        i64 iDelta = 0;
        int iOff = 0;

        writer.bFirstRowidInPage = 0;

        /* The entire doclist will not fit on this leaf. The following 
        ** loop iterates through the poslists that make up the current 
        ** doclist.  */
        while( p->rc==SQLITE_OK && iOff<nDoclist ){
          int nPos;
          int nCopy;
          int bDummy;
................................................................................
            writer.bFirstRowidInPage = 0;
            fts5WriteDlidxAppend(p, &writer, iRowid);
          }else{
            pBuf->n += sqlite3Fts5PutVarint(&pBuf->p[pBuf->n], iDelta);
          }
          assert( pBuf->n<=pBuf->nSpace );

          if( (pBuf->n + nCopy) <= pgsz ){
            /* The entire poslist will fit on the current leaf. So copy
            ** it in one go. */
            fts5BufferSafeAppendBlob(pBuf, &pDoclist[iOff], nCopy);
          }else{
            /* The entire poslist will not fit on this leaf. So it needs
            ** to be broken into sections. The only qualification being
            ** that each varint must be stored contiguously.  */
            const u8 *pPoslist = &pDoclist[iOff];
            int iPos = 0;
            while( p->rc==SQLITE_OK ){
              int nSpace = pgsz - pBuf->n;
              int n = 0;
              if( (nCopy - iPos)<=nSpace ){
                n = nCopy - iPos;
              }else{
                n = fts5PoslistPrefix(&pPoslist[iPos], nSpace);
              }
              assert( n>0 );
              fts5BufferSafeAppendBlob(pBuf, &pPoslist[iPos], n);
              iPos += n;
              if( pBuf->n>=pgsz ){
                fts5WriteFlushLeaf(p, &writer);
                pBuf = &writer.writer.buf;
              }
              if( iPos>=nCopy ) break;
            }
          }
          iOff += nCopy;
        }
      }


      pBuf->p[pBuf->n++] = '\0';
      assert( pBuf->n<=pBuf->nSpace );
      zPrev = (const u8*)zTerm;
      sqlite3Fts5HashScanNext(pHash);
    }
    sqlite3Fts5HashClear(pHash);
    fts5WriteFinish(p, &writer, &nHeight, &pgnoLast);

    /* Update the Fts5Structure. It is written back to the database by the
    ** fts5StructureRelease() call below.  */
    if( pStruct->nLevel==0 ){
      fts5StructureAddLevel(&p->rc, &pStruct);
    }
    fts5StructureExtendLevel(&p->rc, pStruct, 0, 1, 0);
    if( p->rc==SQLITE_OK ){
      pSeg = &pStruct->aLevel[0].aSeg[ pStruct->aLevel[0].nSeg++ ];
      pSeg->iSegid = iSegid;
      pSeg->nHeight = nHeight;
      pSeg->pgnoFirst = 1;
      pSeg->pgnoLast = pgnoLast;
      pStruct->nSegment++;
    }
    fts5StructurePromote(p, 0, pStruct);
  }

................................................................................
}

static void fts5PoslistCallback(
  Fts5Index *p, 
  void *pCtx, 
  const u8 *pChunk, int nChunk
){


  fts5BufferAppendBlob(&p->rc, (Fts5Buffer*)pCtx, nChunk, pChunk);

}

/*
** Iterator pIter currently points to a valid entry (not EOF). This
** function appends the position list data for the current entry to
** buffer pBuf. It does not make a copy of the position-list size
** field.
................................................................................
    for(fts5MultiIterNew(p, pStruct, 1, flags, pToken, nToken, -1, 0, &p1);
        fts5MultiIterEof(p, p1)==0;
        fts5MultiIterNext(p, p1, 0, 0)
    ){
      i64 iRowid = fts5MultiIterRowid(p1);
      int nTerm;
      const u8 *pTerm = fts5MultiIterTerm(p1, &nTerm);
      assert( memcmp(pToken, pTerm, MIN(nToken, nTerm))<=0 );
      if( nTerm<nToken || memcmp(pToken, pTerm, nToken) ) break;

      if( doclist.n>0 && iRowid<=iLastRowid ){
        for(i=0; p->rc==SQLITE_OK && doclist.n; i++){
          assert( i<nBuf );
          if( aBuf[i].n==0 ){
            fts5BufferSwap(&doclist, &aBuf[i]);
................................................................................
      fts5BufferFree(&aBuf[i]);
    }
    fts5MultiIterFree(p, p1);

    pData = fts5IdxMalloc(p, sizeof(Fts5Data) + doclist.n);
    if( pData ){
      pData->p = (u8*)&pData[1];
      pData->n = doclist.n;
      memcpy(pData->p, doclist.p, doclist.n);
      fts5MultiIterNew2(p, pData, bDesc, ppIter);
    }
    fts5BufferFree(&doclist);
  }

  fts5StructureRelease(pStruct);
................................................................................
       || (flags & FTS5INDEX_QUERY_SCAN)==FTS5INDEX_QUERY_SCAN
  );

  if( sqlite3Fts5BufferGrow(&p->rc, &buf, nToken+1)==0 ){
    memcpy(&buf.p[1], pToken, nToken);

#ifdef SQLITE_DEBUG





    if( flags & FTS5INDEX_QUERY_TEST_NOIDX ){
      assert( flags & FTS5INDEX_QUERY_PREFIX );
      iIdx = 1+pConfig->nPrefix;
    }else
#endif
    if( flags & FTS5INDEX_QUERY_PREFIX ){
      int nChar = fts5IndexCharlen(pToken, nToken);
      for(iIdx=1; iIdx<=pConfig->nPrefix; iIdx++){
................................................................................
  int *pn,                        /* OUT: Size of position-list in bytes */
  i64 *piRowid                    /* OUT: Current rowid */
){
  Fts5SegIter *pSeg = &pIter->aSeg[ pIter->aFirst[1].iFirst ];
  assert( pIter->pIndex->rc==SQLITE_OK );
  *piRowid = pSeg->iRowid;
  *pn = pSeg->nPos;
  if( pSeg->iLeafOffset+pSeg->nPos <= pSeg->pLeaf->n ){
    *pp = &pSeg->pLeaf->p[pSeg->iLeafOffset];
  }else{
    fts5BufferZero(&pIter->poslist);
    fts5SegiterPoslist(pIter->pIndex, pSeg, &pIter->poslist);
    *pp = pIter->poslist.p;
  }
  return fts5IndexReturn(pIter->pIndex);
................................................................................
int sqlite3Fts5IndexGetAverages(Fts5Index *p, i64 *pnRow, i64 *anSize){
  int nCol = p->pConfig->nCol;
  Fts5Data *pData;

  *pnRow = 0;
  memset(anSize, 0, sizeof(i64) * nCol);
  pData = fts5DataRead(p, FTS5_AVERAGES_ROWID);
  if( p->rc==SQLITE_OK && pData->n ){
    int i = 0;
    int iCol;
    i += fts5GetVarint(&pData->p[i], (u64*)pnRow);
    for(iCol=0; i<pData->n && iCol<nCol; iCol++){
      i += fts5GetVarint(&pData->p[i], (u64*)&anSize[iCol]);
    }
  }

  fts5DataRelease(pData);
  return fts5IndexReturn(p);
}
................................................................................
    if( rc==SQLITE_OK ){
      int f = flags|FTS5INDEX_QUERY_DESC;
      rc = fts5QueryCksum(p, iIdx, zTerm, nTerm, f, &ck2);
    }
    if( rc==SQLITE_OK && ck1!=ck2 ) rc = FTS5_CORRUPT;

    /* If this is a prefix query, check that the results returned if the
    ** the index is disabled are the same. In both ASC and DESC order. */






    if( iIdx>0 && rc==SQLITE_OK ){
      int f = flags|FTS5INDEX_QUERY_TEST_NOIDX;
      ck2 = 0;
      rc = fts5QueryCksum(p, iIdx, zTerm, nTerm, f, &ck2);
      if( rc==SQLITE_OK && ck1!=ck2 ) rc = FTS5_CORRUPT;
    }
    if( iIdx>0 && rc==SQLITE_OK ){
      int f = flags|FTS5INDEX_QUERY_TEST_NOIDX|FTS5INDEX_QUERY_DESC;
      ck2 = 0;
      rc = fts5QueryCksum(p, iIdx, zTerm, nTerm, f, &ck2);
      if( rc==SQLITE_OK && ck1!=ck2 ) rc = FTS5_CORRUPT;

    }

    cksum3 ^= ck1;
    fts5BufferSet(&rc, pPrev, n, (const u8*)z);

    if( rc==SQLITE_OK && cksum3!=expected ){
      rc = FTS5_CORRUPT;
................................................................................
  int iLast
){
  int i;

  /* Now check that the iter.nEmpty leaves following the current leaf
  ** (a) exist and (b) contain no terms. */
  for(i=iFirst; p->rc==SQLITE_OK && i<=iLast; i++){
    Fts5Data *pLeaf = fts5DataRead(p, FTS5_SEGMENT_ROWID(pSeg->iSegid, 0, i));
    if( pLeaf ){
      if( 0!=fts5GetU16(&pLeaf->p[2]) ) p->rc = FTS5_CORRUPT;
      if( i>=iNoRowid && 0!=fts5GetU16(&pLeaf->p[0]) ) p->rc = FTS5_CORRUPT;
    }
    fts5DataRelease(pLeaf);









































    if( p->rc ) break;


  }
}







static void fts5IndexIntegrityCheckSegment(
  Fts5Index *p,                   /* FTS5 backend object */
  Fts5StructureSegment *pSeg      /* Segment to check internal consistency */
){
  Fts5Config *pConfig = p->pConfig;
  sqlite3_stmt *pStmt = 0;
................................................................................
  int rc2;
  int iIdxPrevLeaf = pSeg->pgnoFirst-1;
  int iDlidxPrevLeaf = pSeg->pgnoLast;

  if( pSeg->pgnoFirst==0 ) return;

  fts5IndexPrepareStmt(p, &pStmt, sqlite3_mprintf(
      "SELECT segid, term, (pgno>>1), (pgno & 1) FROM '%q'.'%q_idx' WHERE segid=%d",
      pConfig->zDb, pConfig->zName, pSeg->iSegid
  ));

  /* Iterate through the b-tree hierarchy.  */
  while( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){
    i64 iRow;                     /* Rowid for this leaf */
    Fts5Data *pLeaf;              /* Data for this leaf */
    int iOff;                     /* Offset of first term on leaf */

    int nIdxTerm = sqlite3_column_bytes(pStmt, 1);
    const char *zIdxTerm = (const char*)sqlite3_column_text(pStmt, 1);
    int iIdxLeaf = sqlite3_column_int(pStmt, 2);
    int bIdxDlidx = sqlite3_column_int(pStmt, 3);

    /* If the leaf in question has already been trimmed from the segment, 
    ** ignore this b-tree entry. Otherwise, load it into memory. */
    if( iIdxLeaf<pSeg->pgnoFirst ) continue;
    iRow = FTS5_SEGMENT_ROWID(pSeg->iSegid, 0, iIdxLeaf);
    pLeaf = fts5DataRead(p, iRow);
    if( pLeaf==0 ) break;

    /* Check that the leaf contains at least one term, and that it is equal
    ** to or larger than the split-key in zIdxTerm.  Also check that if there
    ** is also a rowid pointer within the leaf page header, it points to a
    ** location before the term.  */
    iOff = fts5GetU16(&pLeaf->p[2]);
    if( iOff==0 ){
      p->rc = FTS5_CORRUPT;
    }else{

      int iRowidOff;
      int nTerm;                  /* Size of term on leaf in bytes */
      int res;                    /* Comparison of term and split-key */


      iRowidOff = fts5GetU16(&pLeaf->p[0]);
      if( iRowidOff>=iOff ){
        p->rc = FTS5_CORRUPT;
      }else{
        iOff += fts5GetVarint32(&pLeaf->p[iOff], nTerm);
        res = memcmp(&pLeaf->p[iOff], zIdxTerm, MIN(nTerm, nIdxTerm));
        if( res==0 ) res = nTerm - nIdxTerm;
        if( res<0 ) p->rc = FTS5_CORRUPT;
      }


    }
    fts5DataRelease(pLeaf);
    if( p->rc ) break;


    /* Now check that the iter.nEmpty leaves following the current leaf
    ** (a) exist and (b) contain no terms. */
................................................................................
      for(pDlidx=fts5DlidxIterInit(p, 0, iSegid, iIdxLeaf);
          fts5DlidxIterEof(p, pDlidx)==0;
          fts5DlidxIterNext(p, pDlidx)
      ){

        /* Check any rowid-less pages that occur before the current leaf. */
        for(iPg=iPrevLeaf+1; iPg<fts5DlidxIterPgno(pDlidx); iPg++){
          iKey = FTS5_SEGMENT_ROWID(iSegid, 0, iPg);
          pLeaf = fts5DataRead(p, iKey);
          if( pLeaf ){
            if( fts5GetU16(&pLeaf->p[0])!=0 ) p->rc = FTS5_CORRUPT;
            fts5DataRelease(pLeaf);
          }
        }
        iPrevLeaf = fts5DlidxIterPgno(pDlidx);

        /* Check that the leaf page indicated by the iterator really does
        ** contain the rowid suggested by the same. */
        iKey = FTS5_SEGMENT_ROWID(iSegid, 0, iPrevLeaf);
        pLeaf = fts5DataRead(p, iKey);
        if( pLeaf ){
          i64 iRowid;
          int iRowidOff = fts5GetU16(&pLeaf->p[0]);

          if( iRowidOff>=pLeaf->n ){
            p->rc = FTS5_CORRUPT;
          }else{
            fts5GetVarint(&pLeaf->p[iRowidOff], (u64*)&iRowid);
            if( iRowid!=fts5DlidxIterRowid(pDlidx) ) p->rc = FTS5_CORRUPT;
          }
          fts5DataRelease(pLeaf);
        }
................................................................................
  for(iLvl=0; iLvl<p->nLevel; iLvl++){
    Fts5StructureLevel *pLvl = &p->aLevel[iLvl];
    sqlite3Fts5BufferAppendPrintf(pRc, pBuf, 
        " {lvl=%d nMerge=%d nSeg=%d", iLvl, pLvl->nMerge, pLvl->nSeg
    );
    for(iSeg=0; iSeg<pLvl->nSeg; iSeg++){
      Fts5StructureSegment *pSeg = &pLvl->aSeg[iSeg];
      sqlite3Fts5BufferAppendPrintf(pRc, pBuf, 
          " {id=%d h=%d leaves=%d..%d}", pSeg->iSegid, pSeg->nHeight, 
          pSeg->pgnoFirst, pSeg->pgnoLast
      );
    }
    sqlite3Fts5BufferAppendPrintf(pRc, pBuf, "}");
  }
}

/*
................................................................................
** may or may not finish within the buffer. This function appends a text
** representation of the part of the doclist that is present to buffer
** pBuf. 
**
** The return value is the number of bytes read from the input buffer.
*/
static int fts5DecodeDoclist(int *pRc, Fts5Buffer *pBuf, const u8 *a, int n){
  i64 iDocid;
  int iOff = 0;


  iOff = sqlite3Fts5GetVarint(&a[iOff], (u64*)&iDocid);
  sqlite3Fts5BufferAppendPrintf(pRc, pBuf, " rowid=%lld", iDocid);

  while( iOff<n ){
    int nPos;
    int bDummy;
    iOff += fts5GetPoslistSize(&a[iOff], &nPos, &bDummy);
    iOff += fts5DecodePoslist(pRc, pBuf, &a[iOff], MIN(n-iOff, nPos));
    if( iOff<n ){
      i64 iDelta;
      iOff += sqlite3Fts5GetVarint(&a[iOff], (u64*)&iDelta);
      if( iDelta==0 ) return iOff;
      iDocid += iDelta;
      sqlite3Fts5BufferAppendPrintf(pRc, pBuf, " rowid=%lld", iDocid);
    }
  }

  return iOff;
}

/*
................................................................................
  Fts5Buffer s;                   /* Build up text to return here */
  int rc = SQLITE_OK;             /* Return code */
  int nSpace = 0;

  assert( nArg==2 );
  memset(&s, 0, sizeof(Fts5Buffer));
  iRowid = sqlite3_value_int64(apVal[0]);




  n = sqlite3_value_bytes(apVal[1]);
  aBlob = sqlite3_value_blob(apVal[1]);

  nSpace = n + FTS5_DATA_ZERO_PADDING;
  a = (u8*)sqlite3Fts5MallocZero(&rc, nSpace);
  if( a==0 ) goto decode_out;
  memcpy(a, aBlob, n);


  fts5DecodeRowid(iRowid, &iSegid, &bDlidx, &iHeight, &iPgno);

  fts5DebugRowid(&rc, &s, iRowid);
  if( bDlidx ){
    Fts5Data dlidx;
    Fts5DlidxLvl lvl;

    dlidx.p = a;
    dlidx.n = n;

    memset(&lvl, 0, sizeof(Fts5DlidxLvl));
    lvl.pData = &dlidx;
    lvl.iLeafPgno = iPgno;

    for(fts5DlidxLvlNext(&lvl); lvl.bEof==0; fts5DlidxLvlNext(&lvl)){
      sqlite3Fts5BufferAppendPrintf(&rc, &s, 
................................................................................
  }else if( iSegid==0 ){
    if( iRowid==FTS5_AVERAGES_ROWID ){
      /* todo */
    }else{
      fts5DecodeStructure(&rc, &s, a, n);
    }
  }else{
    Fts5Buffer term;



    int iTermOff = 0;
    int iRowidOff = 0;
    int iOff;
    int nKeep = 0;

    memset(&term, 0, sizeof(Fts5Buffer));

    if( n>=4 ){
      iRowidOff = fts5GetU16(&a[0]);
      iTermOff = fts5GetU16(&a[2]);
    }else{
      sqlite3Fts5BufferSet(&rc, &s, 8, (const u8*)"corrupt");
      goto decode_out;





    }



    if( iRowidOff ){
      iOff = iRowidOff;
    }else if( iTermOff ){
      iOff = iTermOff;
    }else{
      iOff = n;
    }
    fts5DecodePoslist(&rc, &s, &a[4], iOff-4);

    assert( iRowidOff==0 || iOff==iRowidOff );
    if( iRowidOff ){



      iOff += fts5DecodeDoclist(&rc, &s, &a[iOff], n-iOff);
    }





    assert( iTermOff==0 || iOff==iTermOff );




    while( iOff<n ){

      int nByte;





      iOff += fts5GetVarint32(&a[iOff], nByte);
      term.n= nKeep;


      fts5BufferAppendBlob(&rc, &term, nByte, &a[iOff]);
      iOff += nByte;

      sqlite3Fts5BufferAppendPrintf(
          &rc, &s, " term=%.*s", term.n, (const char*)term.p
          );
      iOff += fts5DecodeDoclist(&rc, &s, &a[iOff], n-iOff);
      if( iOff<n ){
        iOff += fts5GetVarint32(&a[iOff], nKeep);
      }
    }
    fts5BufferFree(&term);
  }
  
 decode_out:
  sqlite3_free(a);
  if( rc==SQLITE_OK ){
    sqlite3_result_text(pCtx, (const char*)s.p, s.n, SQLITE_TRANSIENT);
................................................................................
  const char *zArg;
  if( nArg==0 ){
    sqlite3_result_error(pCtx, "should be: fts5_rowid(subject, ....)", -1);
  }else{
    zArg = (const char*)sqlite3_value_text(apVal[0]);
    if( 0==sqlite3_stricmp(zArg, "segment") ){
      i64 iRowid;
      int segid, height, pgno;
      if( nArg!=4 ){
        sqlite3_result_error(pCtx, 
            "should be: fts5_rowid('segment', segid, height, pgno))", -1
        );
      }else{
        segid = sqlite3_value_int(apVal[1]);
        height = sqlite3_value_int(apVal[2]);
        pgno = sqlite3_value_int(apVal[3]);
        iRowid = FTS5_SEGMENT_ROWID(segid, height, pgno);
        sqlite3_result_int64(pCtx, iRowid);
      }
    }else {
      sqlite3_result_error(pCtx, 
        "first arg to fts5_rowid() must be 'segment' "
        "or 'start-of-index'"
        , -1
      );
    }
  }
}

/*
** This is called as part of registering the FTS5 module with database

**
**   Then, for each level from 0 to nMax:
**
**     + number of input segments in ongoing merge.
**     + total number of segments in level.
**     + for each segment from oldest to newest:
**         + segment id (always > 0)

**         + first leaf page number (often 1, always greater than 0)
**         + final leaf page number
**
** 2. The Averages Record:
**
**   A single record within the %_data table. The data is a list of varints.
**   The first value is the number of rows in the index. Then, for each column
**   from left to right, the total number of tokens in the column for all
**   rows of the table.
**
** 3. Segment leaves:
**
**   TERM/DOCLIST FORMAT:
**
**     Most of each segment leaf is taken up by term/doclist data. The 
**     general format of term/doclist, starting with the first term
**     on the leaf page, is:
**
**         varint : size of first term
**         blob:    first term data
**         doclist: first doclist
**         zero-or-more {
**           varint:  number of bytes in common with previous term
**           varint:  number of bytes of new term data (nNew)
................................................................................
**
**         varint:  first rowid
**         poslist: first poslist
**         zero-or-more {
**           varint:  rowid delta (always > 0)
**           poslist: next poslist
**         }

**
**     poslist format:
**
**         varint: size of poslist in bytes multiplied by 2, not including
**                 this field. Plus 1 if this entry carries the "delete" flag.
**         collist: collist for column 0
**         zero-or-more {
................................................................................
**     collist format:
**
**         varint: first offset + 2
**         zero-or-more {
**           varint: offset delta + 2
**         }
**
**   PAGE FORMAT
**
**     Each leaf page begins with a 4-byte header containing 2 16-bit 
**     unsigned integer fields in big-endian format. They are:
**
**       * The byte offset of the first rowid on the page, if it exists
**         and occurs before the first term (otherwise 0).
**
**       * The byte offset of the start of the page footer. If the page
**         footer is 0 bytes in size, then this field is the same as the
**         size of the leaf page in bytes.
**
**     The page footer consists of a single varint for each term located
**     on the page. Each varint is the byte offset of the current term
**     within the page, delta-compressed against the previous value. In
**     other words, the first varint in the footer is the byte offset of
**     the first term, the second is the byte offset of the second less that
**     of the first, and so on.
**
**     The term/doclist format described above is accurate if the entire
**     term/doclist data fits on a single leaf page. If this is not the case,
**     the format is changed in two ways:
**
**       + if the first rowid on a page occurs before the first term, it
**         is stored as a literal value:
**
**             varint:  first rowid
**
**       + the first term on each page is stored in the same way as the
**         very first term of the segment:
**
**             varint : size of first term
**             blob:    first term data
**







































** 5. Segment doclist indexes:
**
**   Doclist indexes are themselves b-trees, however they usually consist of
**   a single leaf record only. The format of each doclist index leaf page 
**   is:
**
**     * Flags byte. Bits are:
................................................................................
/*
** Rowids for the averages and structure records in the %_data table.
*/
#define FTS5_AVERAGES_ROWID     1    /* Rowid used for the averages record */
#define FTS5_STRUCTURE_ROWID   10    /* The structure record */

/*
** Macros determining the rowids used by segment leaves and dlidx leaves

** and nodes. All nodes and leaves are stored in the %_data table with large
** positive rowids.
**
** Each segment has a unique non-zero 16-bit id.

**
** The rowid for each segment leaf is found by passing the segment id and 
** the leaf page number to the FTS5_SEGMENT_ROWID macro. Leaves are numbered
** sequentially starting from 1.









*/
#define FTS5_DATA_ID_B     16     /* Max seg id number 65535 */
#define FTS5_DATA_DLI_B     1     /* Doclist-index flag (1 bit) */
#define FTS5_DATA_HEIGHT_B  5     /* Max dlidx tree height of 32 */
#define FTS5_DATA_PAGE_B   31     /* Max page number of 2147483648 */

#define fts5_dri(segid, dlidx, height, pgno) (                                 \
 ((i64)(segid)  << (FTS5_DATA_PAGE_B+FTS5_DATA_HEIGHT_B+FTS5_DATA_DLI_B)) +    \
 ((i64)(dlidx)  << (FTS5_DATA_PAGE_B + FTS5_DATA_HEIGHT_B)) +                  \
 ((i64)(height) << (FTS5_DATA_PAGE_B)) +                                       \
 ((i64)(pgno))                                                                 \
)

#define FTS5_SEGMENT_ROWID(segid, pgno)       fts5_dri(segid, 0, 0, pgno)
#define FTS5_DLIDX_ROWID(segid, height, pgno) fts5_dri(segid, 1, height, pgno)

/*
** Maximum segments permitted in a single index 
*/
#define FTS5_MAX_SEGMENT 2000

#ifdef SQLITE_DEBUG
................................................................................
typedef struct Fts5SegWriter Fts5SegWriter;
typedef struct Fts5Structure Fts5Structure;
typedef struct Fts5StructureLevel Fts5StructureLevel;
typedef struct Fts5StructureSegment Fts5StructureSegment;

struct Fts5Data {
  u8 *p;                          /* Pointer to buffer containing record */
  int nn;                         /* Size of record in bytes */
  int szLeaf;                     /* Size of leaf without page-index */
};

/*
** One object per %_data table.
*/
struct Fts5Index {
  Fts5Config *pConfig;            /* Virtual table configuration */
................................................................................
/*
** The contents of the "structure" record for each index are represented
** using an Fts5Structure record in memory. Which uses instances of the 
** other Fts5StructureXXX types as components.
*/
struct Fts5StructureSegment {
  int iSegid;                     /* Segment id */

  int pgnoFirst;                  /* First leaf page number in segment */
  int pgnoLast;                   /* Last leaf page number in segment */
};
struct Fts5StructureLevel {
  int nMerge;                     /* Number of segments in incr-merge */
  int nSeg;                       /* Total number of segments on level */
  Fts5StructureSegment *aSeg;     /* Array of segments. aSeg[0] is oldest. */
................................................................................
};

/*
** An object of type Fts5SegWriter is used to write to segments.
*/
struct Fts5PageWriter {
  int pgno;                       /* Page number for this page */
  int iPrevPgidx;                 /* Previous value written into pgidx */
  Fts5Buffer buf;                 /* Buffer containing leaf data */
  Fts5Buffer pgidx;               /* Buffer containing page-index */
  Fts5Buffer term;                /* Buffer containing previous term on page */
};
struct Fts5DlidxWriter {
  int pgno;                       /* Page number for this page */
  int bPrevValid;                 /* True if iPrev is valid */
  i64 iPrev;                      /* Previous rowid value written to page */
  Fts5Buffer buf;                 /* Buffer containing page data */
................................................................................
};
struct Fts5SegWriter {
  int iSegid;                     /* Segid to write to */
  Fts5PageWriter writer;          /* PageWriter object */
  i64 iPrevRowid;                 /* Previous rowid written to current leaf */
  u8 bFirstRowidInDoclist;        /* True if next rowid is first in doclist */
  u8 bFirstRowidInPage;           /* True if next rowid is first in page */
  /* TODO1: Can use (writer.pgidx.n==0) instead of bFirstTermInPage */
  u8 bFirstTermInPage;            /* True if next term will be first in leaf */
  int nLeafWritten;               /* Number of leaf pages written */
  int nEmpty;                     /* Number of contiguous term-less nodes */

  int nDlidx;                     /* Allocated size of aDlidx[] array */
  Fts5DlidxWriter *aDlidx;        /* Array of Fts5DlidxWriter objects */

................................................................................
**
** iRowidOffset/nRowidOffset/aRowidOffset:
**     These are used if the FTS5_SEGITER_REVERSE flag is set.
**
**     For each rowid on the page corresponding to the current term, the
**     corresponding aRowidOffset[] entry is set to the byte offset of the
**     start of the "position-list-size" field within the page.
**
** iTermIdx:
**     Index of current term on iTermLeafPgno.
*/
struct Fts5SegIter {
  Fts5StructureSegment *pSeg;     /* Segment to iterate through */
  int flags;                      /* Mask of configuration flags */
  int iLeafPgno;                  /* Current leaf page number */
  Fts5Data *pLeaf;                /* Current leaf data */
  Fts5Data *pNextLeaf;            /* Leaf page (iLeafPgno+1) */
  int iLeafOffset;                /* Byte offset within current leaf */

  /* The page and offset from which the current term was read. The offset 
  ** is the offset of the first rowid in the current doclist.  */
  int iTermLeafPgno;
  int iTermLeafOffset;

  int iPgidxOff;                  /* Next offset in pgidx */
  int iEndofDoclist;

  /* The following are only used if the FTS5_SEGITER_REVERSE flag is set. */
  int iRowidOffset;               /* Current entry in aRowidOffset[] */
  int nRowidOffset;               /* Allocated size of aRowidOffset[] array */
  int *aRowidOffset;              /* Array of offset to rowid fields */

  Fts5DlidxIter *pDlidx;          /* If there is a doclist-index */
................................................................................

  /* Variables populated based on current entry. */
  Fts5Buffer term;                /* Current term */
  i64 iRowid;                     /* Current rowid */
  int nPos;                       /* Number of bytes in current position list */
  int bDel;                       /* True if the delete flag is set */
};

/*
** Argument is a pointer to an Fts5Data structure that contains a 
** leaf page.
*/
#define ASSERT_SZLEAF_OK(x) assert( \
    (x)->szLeaf==(x)->nn || (x)->szLeaf==fts5GetU16(&(x)->p[2]) \
)

#define FTS5_SEGITER_ONETERM 0x01
#define FTS5_SEGITER_REVERSE 0x02


/* 
** Argument is a pointer to an Fts5Data structure that contains a leaf
** page. This macro evaluates to true if the leaf contains no terms, or
** false if it contains at least one term.
*/
#define fts5LeafIsTermless(x) ((x)->szLeaf >= (x)->nn)

#define fts5LeafTermOff(x, i) (fts5GetU16(&(x)->p[(x)->szLeaf + (i)*2]))

#define fts5LeafFirstRowidOff(x) (fts5GetU16((x)->p))

/*
** poslist:
**   Used by sqlite3Fts5IterPoslist() when the poslist needs to be buffered.
**   There is no way to tell if this is populated or not.
*/
struct Fts5IndexIter {
  Fts5Index *pIndex;              /* Index that owns this iterator */
................................................................................
){
  int nCmp = MIN(nLeft, nRight);
  int res = memcmp(pLeft, pRight, nCmp);
  return (res==0 ? (nLeft - nRight) : res);
}
#endif

static int fts5LeafFirstTermOff(Fts5Data *pLeaf){
  int ret;
  fts5GetVarint32(&pLeaf->p[pLeaf->szLeaf], ret);
  return ret;
}

/*
** Close the read-only blob handle, if it is open.
*/
static void fts5CloseReader(Fts5Index *p){
  if( p->pReader ){
    sqlite3_blob *pReader = p->pReader;
................................................................................

    if( rc==SQLITE_OK ){
      u8 *aOut = 0;               /* Read blob data into this buffer */
      int nByte = sqlite3_blob_bytes(p->pReader);
      int nAlloc = sizeof(Fts5Data) + nByte + FTS5_DATA_PADDING;
      pRet = (Fts5Data*)sqlite3_malloc(nAlloc);
      if( pRet ){
        pRet->nn = nByte;
        aOut = pRet->p = (u8*)&pRet[1];
      }else{
        rc = SQLITE_NOMEM;
      }

      if( rc==SQLITE_OK ){
        rc = sqlite3_blob_read(p->pReader, aOut, nByte, 0);
      }
      if( rc!=SQLITE_OK ){
        sqlite3_free(pRet);
        pRet = 0;
      }else{
        /* TODO1: Fix this */
        pRet->szLeaf = fts5GetU16(&pRet->p[2]);
      }
    }
    p->rc = rc;
    p->nRead++;
  }

  assert( (pRet==0)==(p->rc!=SQLITE_OK) );
................................................................................
/*
** INSERT OR REPLACE a record into the %_data table.
*/
static void fts5DataWrite(Fts5Index *p, i64 iRowid, const u8 *pData, int nData){
  if( p->rc!=SQLITE_OK ) return;

  if( p->pWriter==0 ){

    Fts5Config *pConfig = p->pConfig;
    fts5IndexPrepareStmt(p, &p->pWriter, sqlite3_mprintf(
          "REPLACE INTO '%q'.'%q_data'(id, block) VALUES(?,?)", 
          pConfig->zDb, pConfig->zName
    ));
    if( p->rc ) return;
  }
................................................................................
  p->rc = sqlite3_reset(p->pDeleter);
}

/*
** Remove all records associated with segment iSegid.
*/
static void fts5DataRemoveSegment(Fts5Index *p, int iSegid){
  i64 iFirst = FTS5_SEGMENT_ROWID(iSegid, 0);
  i64 iLast = FTS5_SEGMENT_ROWID(iSegid+1, 0)-1;
  fts5DataDelete(p, iFirst, iLast);
  if( p->pIdxDeleter==0 ){
    Fts5Config *pConfig = p->pConfig;
    fts5IndexPrepareStmt(p, &p->pIdxDeleter, sqlite3_mprintf(
          "DELETE FROM '%q'.'%q_idx' WHERE segid=?",
          pConfig->zDb, pConfig->zName
    ));
................................................................................
          nTotal * sizeof(Fts5StructureSegment)
      );

      if( rc==SQLITE_OK ){
        pLvl->nSeg = nTotal;
        for(iSeg=0; iSeg<nTotal; iSeg++){
          i += fts5GetVarint32(&pData[i], pLvl->aSeg[iSeg].iSegid);

          i += fts5GetVarint32(&pData[i], pLvl->aSeg[iSeg].pgnoFirst);
          i += fts5GetVarint32(&pData[i], pLvl->aSeg[iSeg].pgnoLast);
        }
      }else{
        fts5StructureRelease(pRet);
        pRet = 0;
      }
................................................................................
** is called, it is a no-op.
*/
static Fts5Structure *fts5StructureRead(Fts5Index *p){
  Fts5Config *pConfig = p->pConfig;
  Fts5Structure *pRet = 0;        /* Object to return */
  int iCookie;                    /* Configuration cookie */
  Fts5Data *pData;


  pData = fts5DataRead(p, FTS5_STRUCTURE_ROWID);
  if( p->rc ) return 0;
  /* TODO: Do we need this if the leaf-index is appended? Probably... */
  memset(&pData->p[pData->nn], 0, FTS5_DATA_PADDING);
  p->rc = fts5StructureDecode(pData->p, pData->nn, &iCookie, &pRet);
  if( p->rc==SQLITE_OK && pConfig->iCookie!=iCookie ){
    p->rc = sqlite3Fts5ConfigLoad(pConfig, iCookie);
  }

  fts5DataRelease(pData);
  if( p->rc!=SQLITE_OK ){
    fts5StructureRelease(pRet);
................................................................................
      Fts5StructureLevel *pLvl = &pStruct->aLevel[iLvl];
      fts5BufferAppendVarint(&p->rc, &buf, pLvl->nMerge);
      fts5BufferAppendVarint(&p->rc, &buf, pLvl->nSeg);
      assert( pLvl->nMerge<=pLvl->nSeg );

      for(iSeg=0; iSeg<pLvl->nSeg; iSeg++){
        fts5BufferAppendVarint(&p->rc, &buf, pLvl->aSeg[iSeg].iSegid);

        fts5BufferAppendVarint(&p->rc, &buf, pLvl->aSeg[iSeg].pgnoFirst);
        fts5BufferAppendVarint(&p->rc, &buf, pLvl->aSeg[iSeg].pgnoLast);
      }
    }

    fts5DataWrite(p, FTS5_STRUCTURE_ROWID, buf.p, buf.n);
    fts5BufferFree(&buf);
................................................................................
){
  if( p->rc==SQLITE_OK ){
    int iTst;
    int iPromote = -1;
    int szPromote = 0;            /* Promote anything this size or smaller */
    Fts5StructureSegment *pSeg;   /* Segment just written */
    int szSeg;                    /* Size of segment just written */
    int nSeg = pStruct->aLevel[iLvl].nSeg;


    if( nSeg==0 ) return;
    pSeg = &pStruct->aLevel[iLvl].aSeg[pStruct->aLevel[iLvl].nSeg-1];
    szSeg = (1 + pSeg->pgnoLast - pSeg->pgnoFirst);

    /* Check for condition (a) */
    for(iTst=iLvl-1; iTst>=0 && pStruct->aLevel[iTst].nSeg==0; iTst--);
    if( iTst>=0 ){
      int i;
................................................................................
    assert( pLvl->bEof==0 );
    pLvl->iOff = 1;
    pLvl->iOff += fts5GetVarint32(&pData->p[1], pLvl->iLeafPgno);
    pLvl->iOff += fts5GetVarint(&pData->p[pLvl->iOff], (u64*)&pLvl->iRowid);
    pLvl->iFirstOff = pLvl->iOff;
  }else{
    int iOff;
    for(iOff=pLvl->iOff; iOff<pData->nn; iOff++){
      if( pData->p[iOff] ) break; 
    }

    if( iOff<pData->nn ){
      i64 iVal;
      pLvl->iLeafPgno += (iOff - pLvl->iOff) + 1;
      iOff += fts5GetVarint(&pData->p[iOff], (u64*)&iVal);
      pLvl->iRowid += iVal;
      pLvl->iOff = iOff;
    }else{
      pLvl->bEof = 1;
................................................................................
static i64 fts5DlidxIterRowid(Fts5DlidxIter *pIter){
  return pIter->aLvl[0].iRowid;
}
static int fts5DlidxIterPgno(Fts5DlidxIter *pIter){
  return pIter->aLvl[0].iLeafPgno;
}






/*
** Load the next leaf page into the segment iterator.
*/
static void fts5SegIterNextPage(
  Fts5Index *p,                   /* FTS5 backend object */
  Fts5SegIter *pIter              /* Iterator to advance to next page */
){
  Fts5Data *pLeaf;
  Fts5StructureSegment *pSeg = pIter->pSeg;
  fts5DataRelease(pIter->pLeaf);
  pIter->iLeafPgno++;
  if( pIter->pNextLeaf ){

    pIter->pLeaf = pIter->pNextLeaf;
    pIter->pNextLeaf = 0;
  }else if( pIter->iLeafPgno<=pSeg->pgnoLast ){
    pIter->pLeaf = fts5DataRead(p, 
        FTS5_SEGMENT_ROWID(pSeg->iSegid, pIter->iLeafPgno)
    );
  }else{
    pIter->pLeaf = 0;
  }
  pLeaf = pIter->pLeaf;

  if( pLeaf ){
    pIter->iPgidxOff = pLeaf->szLeaf;
    if( fts5LeafIsTermless(pLeaf) ){
      pIter->iEndofDoclist = pLeaf->nn+1;
    }else{
      pIter->iPgidxOff += fts5GetVarint32(&pLeaf->p[pIter->iPgidxOff],
          pIter->iEndofDoclist
      );
    }
  }
}

/*
** Argument p points to a buffer containing a varint to be interpreted as a
** position list size field. Read the varint and return the number of bytes
** read. Before returning, set *pnSz to the number of bytes in the position
................................................................................
**
** Leave Fts5SegIter.iLeafOffset pointing to the first byte of the 
** position list content (if any).
*/
static void fts5SegIterLoadNPos(Fts5Index *p, Fts5SegIter *pIter){
  if( p->rc==SQLITE_OK ){
    int iOff = pIter->iLeafOffset;  /* Offset to read at */
    ASSERT_SZLEAF_OK(pIter->pLeaf);
    if( iOff>=pIter->pLeaf->szLeaf ){
      p->rc = FTS5_CORRUPT;
    }else{
      const u8 *a = &pIter->pLeaf->p[iOff];
      pIter->iLeafOffset += fts5GetPoslistSize(a, &pIter->nPos, &pIter->bDel);
    }
  }
}

static void fts5SegIterLoadRowid(Fts5Index *p, Fts5SegIter *pIter){
  u8 *a = pIter->pLeaf->p;        /* Buffer to read data from */
  int iOff = pIter->iLeafOffset;

  ASSERT_SZLEAF_OK(pIter->pLeaf);
  if( iOff>=pIter->pLeaf->szLeaf ){
    fts5SegIterNextPage(p, pIter);
    if( pIter->pLeaf==0 ){
      if( p->rc==SQLITE_OK ) p->rc = FTS5_CORRUPT;
      return;
    }
    iOff = 4;
    a = pIter->pLeaf->p;
................................................................................
  iOff += fts5GetVarint32(&a[iOff], nNew);
  pIter->term.n = nKeep;
  fts5BufferAppendBlob(&p->rc, &pIter->term, nNew, &a[iOff]);
  iOff += nNew;
  pIter->iTermLeafOffset = iOff;
  pIter->iTermLeafPgno = pIter->iLeafPgno;
  pIter->iLeafOffset = iOff;

  if( pIter->iPgidxOff>=pIter->pLeaf->nn ){
    pIter->iEndofDoclist = pIter->pLeaf->nn+1;
  }else{
    int nExtra;
    pIter->iPgidxOff += fts5GetVarint32(&a[pIter->iPgidxOff], nExtra);
    pIter->iEndofDoclist += nExtra;
  }

  fts5SegIterLoadRowid(p, pIter);
}

/*
** Initialize the iterator object pIter to iterate through the entries in
** segment pSeg. The iterator is left pointing to the first entry when 
................................................................................
    memset(pIter, 0, sizeof(*pIter));
    pIter->pSeg = pSeg;
    pIter->iLeafPgno = pSeg->pgnoFirst-1;
    fts5SegIterNextPage(p, pIter);
  }

  if( p->rc==SQLITE_OK ){

    pIter->iLeafOffset = 4;
    assert_nc( pIter->pLeaf->nn>4 );
    assert( fts5LeafFirstTermOff(pIter->pLeaf)==4 );
    pIter->iPgidxOff = pIter->pLeaf->szLeaf+1;
    fts5SegIterLoadTerm(p, pIter, 0);
    fts5SegIterLoadNPos(p, pIter);
  }
}

/*
** This function is only ever called on iterators created by calls to
................................................................................
** This function advances the iterator so that it points to the last 
** relevant rowid on the page and, if necessary, initializes the 
** aRowidOffset[] and iRowidOffset variables. At this point the iterator
** is in its regular state - Fts5SegIter.iLeafOffset points to the first
** byte of the position list content associated with said rowid.
*/
static void fts5SegIterReverseInitPage(Fts5Index *p, Fts5SegIter *pIter){
  int n = pIter->pLeaf->szLeaf;
  int i = pIter->iLeafOffset;
  u8 *a = pIter->pLeaf->p;
  int iRowidOffset = 0;

  if( n>pIter->iEndofDoclist ){
    n = pIter->iEndofDoclist;
  }

  ASSERT_SZLEAF_OK(pIter->pLeaf);
  while( 1 ){
    i64 iDelta = 0;
    int nPos;
    int bDummy;

    i += fts5GetPoslistSize(&a[i], &nPos, &bDummy);
    i += nPos;
    if( i>=n ) break;
    i += fts5GetVarint(&a[i], (u64*)&iDelta);

    pIter->iRowid += iDelta;

    if( iRowidOffset>=pIter->nRowidOffset ){
      int nNew = pIter->nRowidOffset + 8;
      int *aNew = (int*)sqlite3_realloc(pIter->aRowidOffset, nNew*sizeof(int));
      if( aNew==0 ){
        p->rc = SQLITE_NOMEM;
................................................................................

  fts5DataRelease(pIter->pLeaf);
  pIter->pLeaf = 0;
  while( p->rc==SQLITE_OK && pIter->iLeafPgno>pIter->iTermLeafPgno ){
    Fts5Data *pNew;
    pIter->iLeafPgno--;
    pNew = fts5DataRead(p, FTS5_SEGMENT_ROWID(
          pIter->pSeg->iSegid, pIter->iLeafPgno
    ));
    if( pNew ){
      /* iTermLeafOffset may be equal to szLeaf if the term is the last
      ** thing on the page - i.e. the first rowid is on the following page.
      ** In this case leaf pIter->pLeaf==0, this iterator is at EOF. */
      if( pIter->iLeafPgno==pIter->iTermLeafPgno 
       && pIter->iTermLeafOffset<pNew->szLeaf 
      ){
        pIter->pLeaf = pNew;
        pIter->iLeafOffset = pIter->iTermLeafOffset;

      }else{
        int iRowidOff;

        iRowidOff = fts5LeafFirstRowidOff(pNew);
        if( iRowidOff ){
          pIter->pLeaf = pNew;
          pIter->iLeafOffset = iRowidOff;
        }
      }

      if( pIter->pLeaf ){
................................................................................
      }else{
        fts5DataRelease(pNew);
      }
    }
  }

  if( pIter->pLeaf ){
    pIter->iEndofDoclist = pIter->pLeaf->nn+1;
    fts5SegIterReverseInitPage(p, pIter);
  }
}

/*
** Return true if the iterator passed as the second argument currently
** points to a delete marker. A delete marker is an entry with a 0 byte
................................................................................
      Fts5Data *pLeaf = pIter->pLeaf;
      int iOff;
      int bNewTerm = 0;
      int nKeep = 0;

      /* Search for the end of the position list within the current page. */
      u8 *a = pLeaf->p;
      int n = pLeaf->szLeaf;

      ASSERT_SZLEAF_OK(pLeaf);
      iOff = pIter->iLeafOffset + pIter->nPos;

      if( iOff<n ){
        /* The next entry is on the current page. */
        assert_nc( iOff<=pIter->iEndofDoclist );
        if( iOff>=pIter->iEndofDoclist ){


          bNewTerm = 1;



          if( iOff!=fts5LeafFirstTermOff(pLeaf) ){
            iOff += fts5GetVarint32(&a[iOff], nKeep);
          }
        }else{
          u64 iDelta;
          iOff += sqlite3Fts5GetVarint(&a[iOff], &iDelta);
          pIter->iRowid += iDelta;
          assert_nc( iDelta>0 );
        }
        pIter->iLeafOffset = iOff;

      }else if( pIter->pSeg==0 ){
        const u8 *pList = 0;
        const char *zTerm = 0;
        int nList = 0;
        if( 0==(pIter->flags & FTS5_SEGITER_ONETERM) ){
          sqlite3Fts5HashScanNext(p->pHash);
          sqlite3Fts5HashScanEntry(p->pHash, &zTerm, &pList, &nList);
        }
        if( pList==0 ){
          fts5DataRelease(pIter->pLeaf);
          pIter->pLeaf = 0;
        }else{
          pIter->pLeaf->p = (u8*)pList;
          pIter->pLeaf->nn = nList;
          pIter->pLeaf->szLeaf = nList;
          pIter->iEndofDoclist = nList+1;
          sqlite3Fts5BufferSet(&p->rc, &pIter->term, strlen(zTerm), (u8*)zTerm);
          pIter->iLeafOffset = fts5GetVarint(pList, (u64*)&pIter->iRowid);
        }
      }else{
        iOff = 0;
        /* Next entry is not on the current page */
        while( iOff==0 ){
          fts5SegIterNextPage(p, pIter);
          pLeaf = pIter->pLeaf;
          if( pLeaf==0 ) break;
          ASSERT_SZLEAF_OK(pLeaf);
          if( (iOff = fts5LeafFirstRowidOff(pLeaf)) && iOff<pLeaf->szLeaf ){
            iOff += sqlite3Fts5GetVarint(&pLeaf->p[iOff], (u64*)&pIter->iRowid);
            pIter->iLeafOffset = iOff;


            if( pLeaf->nn>pLeaf->szLeaf ){
              pIter->iPgidxOff = pLeaf->szLeaf + fts5GetVarint32(
                  &pLeaf->p[pLeaf->szLeaf], pIter->iEndofDoclist
              );
            }

          }
          else if( pLeaf->nn>pLeaf->szLeaf ){
            pIter->iPgidxOff = pLeaf->szLeaf + fts5GetVarint32(
                &pLeaf->p[pLeaf->szLeaf], iOff
            );
            pIter->iLeafOffset = iOff;
            pIter->iEndofDoclist = iOff;
            bNewTerm = 1;
          }
          if( iOff>=pLeaf->szLeaf ){
            p->rc = FTS5_CORRUPT;
            return;
          }
        }
      }

      /* Check if the iterator is now at EOF. If so, return early. */
................................................................................
  Fts5DlidxIter *pDlidx = pIter->pDlidx;
  Fts5Data *pLast = 0;
  int pgnoLast = 0;

  if( pDlidx ){
    int iSegid = pIter->pSeg->iSegid;
    pgnoLast = fts5DlidxIterPgno(pDlidx);
    pLast = fts5DataRead(p, FTS5_SEGMENT_ROWID(iSegid, pgnoLast));
  }else{

    Fts5Data *pLeaf = pIter->pLeaf;         /* Current leaf data */

    /* Currently, Fts5SegIter.iLeafOffset points to the first byte of
    ** position-list content for the current rowid. Back it up so that it
    ** points to the start of the position-list size field. */
    pIter->iLeafOffset -= sqlite3Fts5GetVarintLen(pIter->nPos*2+pIter->bDel);





















    /* If this condition is true then the largest rowid for the current
    ** term may not be stored on the current page. So search forward to
    ** see where said rowid really is.  */
    if( pIter->iEndofDoclist>=pLeaf->szLeaf ){
      int pgno;
      Fts5StructureSegment *pSeg = pIter->pSeg;

      /* The last rowid in the doclist may not be on the current page. Search
      ** forward to find the page containing the last rowid.  */
      for(pgno=pIter->iLeafPgno+1; !p->rc && pgno<=pSeg->pgnoLast; pgno++){
        i64 iAbs = FTS5_SEGMENT_ROWID(pSeg->iSegid, pgno);
        Fts5Data *pNew = fts5DataRead(p, iAbs);
        if( pNew ){
          int iRowid, bTermless;
          iRowid = fts5LeafFirstRowidOff(pNew);
          bTermless = fts5LeafIsTermless(pNew);
          if( iRowid ){
            SWAPVAL(Fts5Data*, pNew, pLast);
            pgnoLast = pgno;
          }
          fts5DataRelease(pNew);
          if( bTermless==0 ) break;
        }
      }
    }
  }

  /* If pLast is NULL at this point, then the last rowid for this doclist
  ** lies on the page currently indicated by the iterator. In this case 
................................................................................
  ** field associated with the first relevant rowid on the page.
  **
  ** Or, if pLast is non-NULL, then it is the page that contains the last
  ** rowid. In this case configure the iterator so that it points to the
  ** first rowid on this page.
  */
  if( pLast ){

    int iOff;
    fts5DataRelease(pIter->pLeaf);
    pIter->pLeaf = pLast;
    pIter->iLeafPgno = pgnoLast;
    iOff = fts5LeafFirstRowidOff(pLast);
    iOff += fts5GetVarint(&pLast->p[iOff], (u64*)&pIter->iRowid);
    pIter->iLeafOffset = iOff;

    if( fts5LeafIsTermless(pLast) ){
      pIter->iEndofDoclist = pLast->nn+1;
    }else{
      pIter->iEndofDoclist = fts5LeafFirstTermOff(pLast);
    }

  }

  fts5SegIterReverseInitPage(p, pIter);
}

/*
** Iterator pIter currently points to the first rowid of a doclist.
................................................................................

  assert( pIter->flags & FTS5_SEGITER_ONETERM );
  assert( pIter->pDlidx==0 );

  /* Check if the current doclist ends on this page. If it does, return
  ** early without loading the doclist-index (as it belongs to a different
  ** term. */
  if( pIter->iTermLeafPgno==pIter->iLeafPgno 
   && pIter->iEndofDoclist<pLeaf->szLeaf 
  ){






    return;




  }

  pIter->pDlidx = fts5DlidxIterInit(p, bRev, iSeg, pIter->iTermLeafPgno);
}

#define fts5IndexGetVarint32(a, iOff, nVal) {     \
  nVal = (a)[iOff++];                             \
  if( nVal & 0x80 ){                              \
    iOff--;                                       \
    iOff += fts5GetVarint32(&(a)[iOff], nVal);    \
  }                                               \
}

#define fts5IndexSkipVarint(a, iOff) {            \
  int iEnd = iOff+9;                              \
  while( (a[iOff++] & 0x80) && iOff<iEnd );       \
}
................................................................................
  Fts5Index *p,                   /* Leave any error code here */
  int bGe,                        /* True for a >= search */
  Fts5SegIter *pIter,             /* Iterator to seek */
  const u8 *pTerm, int nTerm      /* Term to search for */
){
  int iOff;
  const u8 *a = pIter->pLeaf->p;
  int szLeaf = pIter->pLeaf->szLeaf;
  int n = pIter->pLeaf->nn;

  int nMatch = 0;
  int nKeep = 0;
  int nNew = 0;
  int iTermOff;
  int iPgidx;                     /* Current offset in pgidx */
  int bEndOfPage = 0;

  assert( p->rc==SQLITE_OK );




  iPgidx = szLeaf;
  iPgidx += fts5GetVarint32(&a[iPgidx], iTermOff);
  iOff = iTermOff;


  while( 1 ){



    /* Figure out how many new bytes are in this term */
    fts5IndexGetVarint32(a, iOff, nNew);

    if( nKeep<nMatch ){
      goto search_failed;
    }

    assert( nKeep>=nMatch );
    if( nKeep==nMatch ){
      int nCmp;
      int i;
      nCmp = MIN(nNew, nTerm-nMatch);
      for(i=0; i<nCmp; i++){
        if( a[iOff+i]!=pTerm[nMatch+i] ) break;
      }
      nMatch += i;

      if( nTerm==nMatch ){
................................................................................
        }else{
          goto search_failed;
        }
      }else if( i<nNew && a[iOff+i]>pTerm[nMatch] ){
        goto search_failed;
      }
    }


    if( iPgidx>=n ){
      bEndOfPage = 1;
      break;

    }





    iPgidx += fts5GetVarint32(&a[iPgidx], nKeep);
    iTermOff += nKeep;

    iOff = iTermOff;










    /* Read the nKeep field of the next term. */
    fts5IndexGetVarint32(a, iOff, nKeep);
  }

 search_failed:
  if( bGe==0 ){
    fts5DataRelease(pIter->pLeaf);
    pIter->pLeaf = 0;
    return;
  }else if( bEndOfPage ){
    do {
      fts5SegIterNextPage(p, pIter);
      if( pIter->pLeaf==0 ) return;
      a = pIter->pLeaf->p;
      if( fts5LeafIsTermless(pIter->pLeaf)==0 ){
        fts5GetVarint32(&pIter->pLeaf->p[pIter->pLeaf->szLeaf], iOff);
        if( iOff<4 || iOff>=pIter->pLeaf->szLeaf ){
          p->rc = FTS5_CORRUPT;
        }else{
          nKeep = 0;
          iOff += fts5GetVarint32(&a[iOff], nNew);
          break;
        }
      }
    }while( 1 );
  }

 search_success:

  pIter->iLeafOffset = iOff + nNew;
  pIter->iTermLeafOffset = pIter->iLeafOffset;
  pIter->iTermLeafPgno = pIter->iLeafPgno;

  fts5BufferSet(&p->rc, &pIter->term, nKeep, pTerm);
  fts5BufferAppendBlob(&p->rc, &pIter->term, nNew, &a[iOff]);

  if( iPgidx>=n ){
    pIter->iEndofDoclist = pIter->pLeaf->nn+1;
  }else{
    int nExtra;
    iPgidx += fts5GetVarint32(&a[iPgidx], nExtra);
    pIter->iEndofDoclist = iTermOff + nExtra;
  }
  pIter->iPgidxOff = iPgidx;

  fts5SegIterLoadRowid(p, pIter);
  fts5SegIterLoadNPos(p, pIter);
}

/*
** Initialize the object pIter to point to term pTerm/nTerm within segment
** pSeg. If there is no such term in the index, the iterator is set to EOF.
................................................................................

  if( pList ){
    Fts5Data *pLeaf;
    sqlite3Fts5BufferSet(&p->rc, &pIter->term, n, z);
    pLeaf = fts5IdxMalloc(p, sizeof(Fts5Data));
    if( pLeaf==0 ) return;
    pLeaf->p = (u8*)pList;
    pLeaf->nn = pLeaf->szLeaf = nList;
    pIter->pLeaf = pLeaf;
    pIter->iLeafOffset = fts5GetVarint(pLeaf->p, (u64*)&pIter->iRowid);
    pIter->iEndofDoclist = pLeaf->nn+1;

    if( flags & FTS5INDEX_QUERY_DESC ){
      pIter->flags |= FTS5_SEGITER_REVERSE;
      fts5SegIterReverseInitPage(p, pIter);
    }else{
      fts5SegIterLoadNPos(p, pIter);
    }
................................................................................
    pIter->iLeafPgno = iLeafPgno-1;
    fts5SegIterNextPage(p, pIter);
    assert( p->rc!=SQLITE_OK || pIter->iLeafPgno==iLeafPgno );

    if( p->rc==SQLITE_OK ){
      int iOff;
      u8 *a = pIter->pLeaf->p;
      int n = pIter->pLeaf->szLeaf;

      iOff = fts5LeafFirstRowidOff(pIter->pLeaf);
      if( iOff<4 || iOff>=n ){
        p->rc = FTS5_CORRUPT;
      }else{
        iOff += fts5GetVarint(&a[iOff], (u64*)&pIter->iRowid);
        pIter->iLeafOffset = iOff;
        fts5SegIterLoadNPos(p, pIter);
      }
................................................................................
){
  Fts5IndexIter *pNew;
  pNew = fts5MultiIterAlloc(p, 2);
  if( pNew ){
    Fts5SegIter *pIter = &pNew->aSeg[1];

    pIter->flags = FTS5_SEGITER_ONETERM;
    if( pData->szLeaf>0 ){
      pIter->pLeaf = pData;
      pIter->iLeafOffset = fts5GetVarint(pData->p, (u64*)&pIter->iRowid);
      pIter->iEndofDoclist = pData->nn;
      pNew->aFirst[1].iFirst = 1;
      if( bDesc ){
        pNew->bRev = 1;
        pIter->flags |= FTS5_SEGITER_REVERSE;
        fts5SegIterReverseInitPage(p, pIter);
      }else{
        fts5SegIterLoadNPos(p, pIter);
................................................................................
  Fts5SegIter *pSeg,              /* Poslist of this iterator */
  void *pCtx,                     /* Context pointer for xChunk callback */
  void (*xChunk)(Fts5Index*, void*, const u8*, int)
){
  int nRem = pSeg->nPos;          /* Number of bytes still to come */
  Fts5Data *pData = 0;
  u8 *pChunk = &pSeg->pLeaf->p[pSeg->iLeafOffset];
  int nChunk = MIN(nRem, pSeg->pLeaf->szLeaf - pSeg->iLeafOffset);
  int pgno = pSeg->iLeafPgno;
  int pgnoSave = 0;

  if( (pSeg->flags & FTS5_SEGITER_REVERSE)==0 ){
    pgnoSave = pgno+1;
  }

................................................................................
    xChunk(p, pCtx, pChunk, nChunk);
    nRem -= nChunk;
    fts5DataRelease(pData);
    if( nRem<=0 ){
      break;
    }else{
      pgno++;
      pData = fts5DataRead(p, FTS5_SEGMENT_ROWID(pSeg->pSeg->iSegid, pgno));
      if( pData==0 ) break;
      pChunk = &pData->p[4];
      nChunk = MIN(nRem, pData->szLeaf - 4);
      if( pgno==pgnoSave ){
        assert( pSeg->pNextLeaf==0 );
        pSeg->pNextLeaf = pData;
        pData = 0;
      }
    }
  }
................................................................................
}

static void fts5WriteFlushLeaf(Fts5Index *p, Fts5SegWriter *pWriter){
  static const u8 zero[] = { 0x00, 0x00, 0x00, 0x00 };
  Fts5PageWriter *pPage = &pWriter->writer;
  i64 iRowid;

  assert( (pPage->pgidx.n==0)==(pWriter->bFirstTermInPage) );

  /* Set the szLeaf header field. */
  assert( 0==fts5GetU16(&pPage->buf.p[2]) );
  fts5PutU16(&pPage->buf.p[2], pPage->buf.n);

  if( pWriter->bFirstTermInPage ){
    /* No term was written to this page. */

    assert( pPage->pgidx.n==0 );
    fts5WriteBtreeNoTerm(p, pWriter);
  }else{
    /* Append the pgidx to the page buffer. Set the szLeaf header field. */
    fts5BufferAppendBlob(&p->rc, &pPage->buf, pPage->pgidx.n, pPage->pgidx.p);
  }

  /* Write the page out to disk */
  iRowid = FTS5_SEGMENT_ROWID(pWriter->iSegid, pPage->pgno);
  fts5DataWrite(p, iRowid, pPage->buf.p, pPage->buf.n);

  /* Initialize the next page. */
  fts5BufferZero(&pPage->buf);
  fts5BufferZero(&pPage->pgidx);
  fts5BufferAppendBlob(&p->rc, &pPage->buf, 4, zero);
  pPage->iPrevPgidx = 0;
  pPage->pgno++;

  /* Increase the leaves written counter */
  pWriter->nLeafWritten++;

  /* The new leaf holds no terms or rowids */
  pWriter->bFirstTermInPage = 1;
................................................................................
static void fts5WriteAppendTerm(
  Fts5Index *p, 
  Fts5SegWriter *pWriter,
  int nTerm, const u8 *pTerm 
){
  int nPrefix;                    /* Bytes of prefix compression for term */
  Fts5PageWriter *pPage = &pWriter->writer;
  Fts5Buffer *pPgidx = &pWriter->writer.pgidx;

  assert( p->rc==SQLITE_OK );
  assert( pPage->buf.n>=4 );
  assert( pPage->buf.n>4 || pWriter->bFirstTermInPage );

  /* If the current leaf page is full, flush it to disk. */
  if( (pPage->buf.n + pPgidx->n + nTerm + 2)>=p->pConfig->pgsz ){
    if( pPage->buf.n>4 ){
      fts5WriteFlushLeaf(p, pWriter);
    }
    fts5BufferGrow(&p->rc, &pPage->buf, nTerm+FTS5_DATA_PADDING);
  }
  
  /* TODO1: Updating pgidx here. */
  pPgidx->n += sqlite3Fts5PutVarint(
      &pPgidx->p[pPgidx->n], pPage->buf.n - pPage->iPrevPgidx
  );
  pPage->iPrevPgidx = pPage->buf.n;
#if 0
  fts5PutU16(&pPgidx->p[pPgidx->n], pPage->buf.n);
  pPgidx->n += 2;
#endif

  if( pWriter->bFirstTermInPage ){
    nPrefix = 0;
    if( pPage->pgno!=1 ){
      /* This is the first term on a leaf that is not the leftmost leaf in
      ** the segment b-tree. In this case it is necessary to add a term to
      ** the b-tree hierarchy that is (a) larger than the largest term 
      ** already written to the segment and (b) smaller than or equal to
      ** this term. In other words, a prefix of (pTerm/nTerm) that is one
................................................................................
  pWriter->bFirstTermInPage = 0;

  pWriter->bFirstRowidInPage = 0;
  pWriter->bFirstRowidInDoclist = 1;

  assert( p->rc || (pWriter->nDlidx>0 && pWriter->aDlidx[0].buf.n==0) );
  pWriter->aDlidx[0].pgno = pPage->pgno;





}

/*
** Append a rowid and position-list size field to the writers output. 
*/
static void fts5WriteAppendRowid(
  Fts5Index *p, 
  Fts5SegWriter *pWriter,
  i64 iRowid,
  int nPos
){
  if( p->rc==SQLITE_OK ){
    Fts5PageWriter *pPage = &pWriter->writer;

    if( (pPage->buf.n + pPage->pgidx.n)>=p->pConfig->pgsz ){
      fts5WriteFlushLeaf(p, pWriter);
    }

    /* If this is to be the first rowid written to the page, set the 
    ** rowid-pointer in the page-header. Also append a value to the dlidx
    ** buffer, in case a doclist-index is required.  */
    if( pWriter->bFirstRowidInPage ){
      fts5PutU16(pPage->buf.p, pPage->buf.n);
      fts5WriteDlidxAppend(p, pWriter, iRowid);
................................................................................
      fts5BufferAppendVarint(&p->rc, &pPage->buf, iRowid - pWriter->iPrevRowid);
    }
    pWriter->iPrevRowid = iRowid;
    pWriter->bFirstRowidInDoclist = 0;
    pWriter->bFirstRowidInPage = 0;

    fts5BufferAppendVarint(&p->rc, &pPage->buf, nPos);




  }
}

static void fts5WriteAppendPoslistData(
  Fts5Index *p, 
  Fts5SegWriter *pWriter, 
  const u8 *aData, 
................................................................................
  int nData
){
  Fts5PageWriter *pPage = &pWriter->writer;
  const u8 *a = aData;
  int n = nData;
  
  assert( p->pConfig->pgsz>0 );
  while( p->rc==SQLITE_OK 
     && (pPage->buf.n + pPage->pgidx.n + n)>=p->pConfig->pgsz 
  ){
    int nReq = p->pConfig->pgsz - pPage->buf.n - pPage->pgidx.n;
    int nCopy = 0;
    while( nCopy<nReq ){
      i64 dummy;
      nCopy += fts5GetVarint(&a[nCopy], (u64*)&dummy);
    }
    fts5BufferAppendBlob(&p->rc, &pPage->buf, nCopy, a);
    a += nCopy;
................................................................................
    fts5WriteFlushLeaf(p, pWriter);
  }
  if( n>0 ){
    fts5BufferAppendBlob(&p->rc, &pPage->buf, n, a);
  }
}





/*
** Flush any data cached by the writer object to the database. Free any
** allocations associated with the writer.
*/
static void fts5WriteFinish(
  Fts5Index *p, 
  Fts5SegWriter *pWriter,         /* Writer object */

  int *pnLeaf                     /* OUT: Number of leaf pages in b-tree */
){
  int i;
  Fts5PageWriter *pLeaf = &pWriter->writer;
  if( p->rc==SQLITE_OK ){
    assert( pLeaf->pgno>=1 );



    if( pLeaf->buf.n>4 ){
      fts5WriteFlushLeaf(p, pWriter);
    }
    *pnLeaf = pLeaf->pgno-1;

    fts5WriteFlushBtree(p, pWriter);


  }
  fts5BufferFree(&pLeaf->term);
  fts5BufferFree(&pLeaf->buf);
  fts5BufferFree(&pLeaf->pgidx);
  fts5BufferFree(&pWriter->btterm);

  for(i=0; i<pWriter->nDlidx; i++){
    sqlite3Fts5BufferFree(&pWriter->aDlidx[i].buf);
  }
  sqlite3_free(pWriter->aDlidx);
}

static void fts5WriteInit(
  Fts5Index *p, 
  Fts5SegWriter *pWriter, 
  int iSegid
){
  const int nBuffer = p->pConfig->pgsz + FTS5_DATA_PADDING;

  memset(pWriter, 0, sizeof(Fts5SegWriter));
  pWriter->iSegid = iSegid;

  fts5WriteDlidxGrow(p, pWriter, 1);
  pWriter->writer.pgno = 1;
  pWriter->bFirstTermInPage = 1;
  pWriter->iBtPage = 1;

  /* Grow the two buffers to pgsz + padding bytes in size. */
  fts5BufferGrow(&p->rc, &pWriter->writer.pgidx, nBuffer);
  fts5BufferGrow(&p->rc, &pWriter->writer.buf, nBuffer);

  if( p->pIdxWriter==0 ){
    Fts5Config *pConfig = p->pConfig;
    fts5IndexPrepareStmt(p, &p->pIdxWriter, sqlite3_mprintf(
          "INSERT INTO '%q'.'%q_idx'(segid,term,pgno) VALUES(?,?,?)", 
          pConfig->zDb, pConfig->zName
    ));
  }

  if( p->rc==SQLITE_OK ){
    /* Initialize the 4-byte leaf-page header to 0x00. */
    memset(pWriter->writer.buf.p, 0, 4);
    pWriter->writer.buf.n = 4;

    /* Bind the current output segment id to the index-writer. This is an
    ** optimization over binding the same value over and over as rows are
    ** inserted into %_idx by the current writer.  */
    sqlite3_bind_int(p->pIdxWriter, 1, pWriter->iSegid);
  }
}

/*
** Iterator pIter was used to iterate through the input segments of on an
** incremental merge operation. This function is called if the incremental
................................................................................
      pSeg->pSeg->pgnoLast = 0;
      pSeg->pSeg->pgnoFirst = 0;
    }else{
      int iOff = pSeg->iTermLeafOffset;     /* Offset on new first leaf page */
      i64 iLeafRowid;
      Fts5Data *pData;
      int iId = pSeg->pSeg->iSegid;
      u8 aHdr[4] = {0x00, 0x00, 0x00, 0x00};

      iLeafRowid = FTS5_SEGMENT_ROWID(iId, pSeg->iTermLeafPgno);
      pData = fts5DataRead(p, iLeafRowid);
      if( pData ){
        fts5BufferZero(&buf);
        fts5BufferGrow(&p->rc, &buf, pData->nn);
        fts5BufferAppendBlob(&p->rc, &buf, sizeof(aHdr), aHdr);
        fts5BufferAppendVarint(&p->rc, &buf, pSeg->term.n);
        fts5BufferAppendBlob(&p->rc, &buf, pSeg->term.n, pSeg->term.p);
        fts5BufferAppendBlob(&p->rc, &buf, pData->szLeaf-iOff, &pData->p[iOff]);
        if( p->rc==SQLITE_OK ){
          /* Set the szLeaf field */
          fts5PutU16(&buf.p[2], buf.n);
        }

        /* Set up the new page-index array */
        fts5BufferAppendVarint(&p->rc, &buf, 4);
        if( pSeg->iLeafPgno==pSeg->iTermLeafPgno 
         && pSeg->iEndofDoclist<pData->szLeaf 
        ){
          int nDiff = pData->szLeaf - pSeg->iEndofDoclist;
          fts5BufferAppendVarint(&p->rc, &buf, buf.n - 1 - nDiff - 4);
          fts5BufferAppendBlob(&p->rc, &buf, 
              pData->nn - pSeg->iPgidxOff, &pData->p[pSeg->iPgidxOff]
          );
        }

        fts5DataRelease(pData);
        pSeg->pSeg->pgnoFirst = pSeg->iTermLeafPgno;
        fts5DataDelete(p, FTS5_SEGMENT_ROWID(iId, 1), iLeafRowid);
        fts5DataWrite(p, iLeafRowid, buf.p, buf.n);
      }
    }
  }
  fts5BufferFree(&buf);
}

................................................................................
  Fts5StructureLevel *pLvlOut;
  Fts5IndexIter *pIter = 0;       /* Iterator to read input data */
  int nRem = pnRem ? *pnRem : 0;  /* Output leaf pages left to write */
  int nInput;                     /* Number of input segments */
  Fts5SegWriter writer;           /* Writer object */
  Fts5StructureSegment *pSeg;     /* Output segment */
  Fts5Buffer term;

  int bOldest;                    /* True if the output segment is the oldest */

  assert( iLvl<pStruct->nLevel );
  assert( pLvl->nMerge<=pLvl->nSeg );

  memset(&writer, 0, sizeof(Fts5SegWriter));
  memset(&term, 0, sizeof(Fts5Buffer));
................................................................................
    pTerm = fts5MultiIterTerm(pIter, &nTerm);
    if( nTerm!=term.n || memcmp(pTerm, term.p, nTerm) ){
      if( pnRem && writer.nLeafWritten>nRem ){
        break;
      }

      /* This is a new term. Append a term to the output segment. */



      fts5WriteAppendTerm(p, &writer, nTerm, pTerm);
      fts5BufferSet(&p->rc, &term, nTerm, pTerm);

    }

    /* Append the rowid to the output */
    /* WRITEPOSLISTSIZE */
    nPos = pSegIter->nPos*2 + pSegIter->bDel;
    fts5WriteAppendRowid(p, &writer, fts5MultiIterRowid(pIter), nPos);

    /* Append the position-list data to the output */
    fts5ChunkIterate(p, pSegIter, (void*)&writer, fts5MergeChunkCallback);
  }

  /* Flush the last leaf page to disk. Set the output segment b-tree height
  ** and last leaf page number at the same time.  */
  fts5WriteFinish(p, &writer, &pSeg->pgnoLast);

  if( fts5MultiIterEof(p, pIter) ){
    int i;

    /* Remove the redundant segments from the %_data table */
    for(i=0; i<nInput; i++){
      fts5DataRemoveSegment(p, pLvl->aSeg[i].iSegid);
................................................................................
  const int nCrisis = p->pConfig->nCrisisMerge;
  Fts5Structure *pStruct = *ppStruct;
  int iLvl = 0;

  assert( p->rc!=SQLITE_OK || pStruct->nLevel>0 );
  while( p->rc==SQLITE_OK && pStruct->aLevel[iLvl].nSeg>=nCrisis ){
    fts5IndexMergeLevel(p, &pStruct, iLvl, 0);
    assert( p->rc!=SQLITE_OK || pStruct->nLevel>(iLvl+1) );
    fts5StructurePromote(p, iLvl+1, pStruct);
    iLvl++;
  }
  *ppStruct = pStruct;
}

static int fts5IndexReturn(Fts5Index *p){
................................................................................
** in a 32-bit integer. Return the size of the largest prefix of this 
** list nMax bytes or less in size.
*/
static int fts5PoslistPrefix(const u8 *aBuf, int nMax){
  int ret;
  u32 dummy;
  ret = fts5GetVarint32(aBuf, dummy);
  if( ret<nMax ){
    while( 1 ){
      int i = fts5GetVarint32(&aBuf[ret], dummy);
      if( (ret + i) > nMax ) break;
      ret += i;
    }
  }
  return ret;
}

#define fts5BufferSafeAppendBlob(pBuf, pBlob, nBlob) { \
  assert( pBuf->nSpace>=(pBuf->n+nBlob) );             \
  memcpy(&pBuf->p[pBuf->n], pBlob, nBlob);             \
................................................................................
  pStruct = fts5StructureRead(p);
  iSegid = fts5AllocateSegid(p, pStruct);

  if( iSegid ){
    const int pgsz = p->pConfig->pgsz;

    Fts5StructureSegment *pSeg;   /* New segment within pStruct */

    Fts5Buffer *pBuf;             /* Buffer in which to assemble leaf page */

    Fts5Buffer *pPgidx;           /* Buffer in which to assemble pgidx */

    Fts5SegWriter writer;
    fts5WriteInit(p, &writer, iSegid);

    pBuf = &writer.writer.buf;
    pPgidx = &writer.writer.pgidx;

    /* fts5WriteInit() should have initialized the buffers to (most likely)
    ** the maximum space required. */
    assert( p->rc || pBuf->nSpace>=(pgsz + FTS5_DATA_PADDING) );
    assert( p->rc || pPgidx->nSpace>=(pgsz + FTS5_DATA_PADDING) );

    /* Begin scanning through hash table entries. This loop runs once for each
    ** term/doclist currently stored within the hash table. */
    if( p->rc==SQLITE_OK ){


      p->rc = sqlite3Fts5HashScanInit(pHash, 0, 0);
    }
    while( p->rc==SQLITE_OK && 0==sqlite3Fts5HashScanEof(pHash) ){
      const char *zTerm;          /* Buffer containing term */

      const u8 *pDoclist;         /* Pointer to doclist for this term */
      int nDoclist;               /* Size of doclist in bytes */


      /* Write the term for this entry to disk. */
      sqlite3Fts5HashScanEntry(pHash, &zTerm, &pDoclist, &nDoclist);

      fts5WriteAppendTerm(p, &writer, strlen(zTerm), (const u8*)zTerm);















      assert( writer.bFirstRowidInPage==0 );























      if( pgsz>=(pBuf->n + pPgidx->n + nDoclist + 1) ){
        /* The entire doclist will fit on the current leaf. */
        fts5BufferSafeAppendBlob(pBuf, pDoclist, nDoclist);
      }else{
        i64 iRowid = 0;
        i64 iDelta = 0;
        int iOff = 0;



        /* The entire doclist will not fit on this leaf. The following 
        ** loop iterates through the poslists that make up the current 
        ** doclist.  */
        while( p->rc==SQLITE_OK && iOff<nDoclist ){
          int nPos;
          int nCopy;
          int bDummy;
................................................................................
            writer.bFirstRowidInPage = 0;
            fts5WriteDlidxAppend(p, &writer, iRowid);
          }else{
            pBuf->n += sqlite3Fts5PutVarint(&pBuf->p[pBuf->n], iDelta);
          }
          assert( pBuf->n<=pBuf->nSpace );

          if( (pBuf->n + pPgidx->n + nCopy) <= pgsz ){
            /* The entire poslist will fit on the current leaf. So copy
            ** it in one go. */
            fts5BufferSafeAppendBlob(pBuf, &pDoclist[iOff], nCopy);
          }else{
            /* The entire poslist will not fit on this leaf. So it needs
            ** to be broken into sections. The only qualification being
            ** that each varint must be stored contiguously.  */
            const u8 *pPoslist = &pDoclist[iOff];
            int iPos = 0;
            while( p->rc==SQLITE_OK ){
              int nSpace = pgsz - pBuf->n - pPgidx->n;
              int n = 0;
              if( (nCopy - iPos)<=nSpace ){
                n = nCopy - iPos;
              }else{
                n = fts5PoslistPrefix(&pPoslist[iPos], nSpace);
              }
              assert( n>0 );
              fts5BufferSafeAppendBlob(pBuf, &pPoslist[iPos], n);
              iPos += n;
              if( (pBuf->n + pPgidx->n)>=pgsz ){
                fts5WriteFlushLeaf(p, &writer);

              }
              if( iPos>=nCopy ) break;
            }
          }
          iOff += nCopy;
        }
      }

      /* TODO2: Doclist terminator written here. */
      /* pBuf->p[pBuf->n++] = '\0'; */
      assert( pBuf->n<=pBuf->nSpace );

      sqlite3Fts5HashScanNext(pHash);
    }
    sqlite3Fts5HashClear(pHash);
    fts5WriteFinish(p, &writer, &pgnoLast);

    /* Update the Fts5Structure. It is written back to the database by the
    ** fts5StructureRelease() call below.  */
    if( pStruct->nLevel==0 ){
      fts5StructureAddLevel(&p->rc, &pStruct);
    }
    fts5StructureExtendLevel(&p->rc, pStruct, 0, 1, 0);
    if( p->rc==SQLITE_OK ){
      pSeg = &pStruct->aLevel[0].aSeg[ pStruct->aLevel[0].nSeg++ ];
      pSeg->iSegid = iSegid;

      pSeg->pgnoFirst = 1;
      pSeg->pgnoLast = pgnoLast;
      pStruct->nSegment++;
    }
    fts5StructurePromote(p, 0, pStruct);
  }

................................................................................
}

static void fts5PoslistCallback(
  Fts5Index *p, 
  void *pCtx, 
  const u8 *pChunk, int nChunk
){
  assert_nc( nChunk>=0 );
  if( nChunk>0 ){
    fts5BufferAppendBlob(&p->rc, (Fts5Buffer*)pCtx, nChunk, pChunk);
  }
}

/*
** Iterator pIter currently points to a valid entry (not EOF). This
** function appends the position list data for the current entry to
** buffer pBuf. It does not make a copy of the position-list size
** field.
................................................................................
    for(fts5MultiIterNew(p, pStruct, 1, flags, pToken, nToken, -1, 0, &p1);
        fts5MultiIterEof(p, p1)==0;
        fts5MultiIterNext(p, p1, 0, 0)
    ){
      i64 iRowid = fts5MultiIterRowid(p1);
      int nTerm;
      const u8 *pTerm = fts5MultiIterTerm(p1, &nTerm);
      assert_nc( memcmp(pToken, pTerm, MIN(nToken, nTerm))<=0 );
      if( nTerm<nToken || memcmp(pToken, pTerm, nToken) ) break;

      if( doclist.n>0 && iRowid<=iLastRowid ){
        for(i=0; p->rc==SQLITE_OK && doclist.n; i++){
          assert( i<nBuf );
          if( aBuf[i].n==0 ){
            fts5BufferSwap(&doclist, &aBuf[i]);
................................................................................
      fts5BufferFree(&aBuf[i]);
    }
    fts5MultiIterFree(p, p1);

    pData = fts5IdxMalloc(p, sizeof(Fts5Data) + doclist.n);
    if( pData ){
      pData->p = (u8*)&pData[1];
      pData->nn = pData->szLeaf = doclist.n;
      memcpy(pData->p, doclist.p, doclist.n);
      fts5MultiIterNew2(p, pData, bDesc, ppIter);
    }
    fts5BufferFree(&doclist);
  }

  fts5StructureRelease(pStruct);
................................................................................
       || (flags & FTS5INDEX_QUERY_SCAN)==FTS5INDEX_QUERY_SCAN
  );

  if( sqlite3Fts5BufferGrow(&p->rc, &buf, nToken+1)==0 ){
    memcpy(&buf.p[1], pToken, nToken);

#ifdef SQLITE_DEBUG
    /* If the QUERY_TEST_NOIDX flag was specified, then this must be a
    ** prefix-query. Instead of using a prefix-index (if one exists), 
    ** evaluate the prefix query using the main FTS index. This is used
    ** for internal sanity checking by the integrity-check in debug 
    ** mode only.  */
    if( pConfig->bPrefixIndex==0 || (flags & FTS5INDEX_QUERY_TEST_NOIDX) ){
      assert( flags & FTS5INDEX_QUERY_PREFIX );
      iIdx = 1+pConfig->nPrefix;
    }else
#endif
    if( flags & FTS5INDEX_QUERY_PREFIX ){
      int nChar = fts5IndexCharlen(pToken, nToken);
      for(iIdx=1; iIdx<=pConfig->nPrefix; iIdx++){
................................................................................
  int *pn,                        /* OUT: Size of position-list in bytes */
  i64 *piRowid                    /* OUT: Current rowid */
){
  Fts5SegIter *pSeg = &pIter->aSeg[ pIter->aFirst[1].iFirst ];
  assert( pIter->pIndex->rc==SQLITE_OK );
  *piRowid = pSeg->iRowid;
  *pn = pSeg->nPos;
  if( pSeg->iLeafOffset+pSeg->nPos <= pSeg->pLeaf->szLeaf ){
    *pp = &pSeg->pLeaf->p[pSeg->iLeafOffset];
  }else{
    fts5BufferZero(&pIter->poslist);
    fts5SegiterPoslist(pIter->pIndex, pSeg, &pIter->poslist);
    *pp = pIter->poslist.p;
  }
  return fts5IndexReturn(pIter->pIndex);
................................................................................
int sqlite3Fts5IndexGetAverages(Fts5Index *p, i64 *pnRow, i64 *anSize){
  int nCol = p->pConfig->nCol;
  Fts5Data *pData;

  *pnRow = 0;
  memset(anSize, 0, sizeof(i64) * nCol);
  pData = fts5DataRead(p, FTS5_AVERAGES_ROWID);
  if( p->rc==SQLITE_OK && pData->nn ){
    int i = 0;
    int iCol;
    i += fts5GetVarint(&pData->p[i], (u64*)pnRow);
    for(iCol=0; i<pData->nn && iCol<nCol; iCol++){
      i += fts5GetVarint(&pData->p[i], (u64*)&anSize[iCol]);
    }
  }

  fts5DataRelease(pData);
  return fts5IndexReturn(p);
}
................................................................................
    if( rc==SQLITE_OK ){
      int f = flags|FTS5INDEX_QUERY_DESC;
      rc = fts5QueryCksum(p, iIdx, zTerm, nTerm, f, &ck2);
    }
    if( rc==SQLITE_OK && ck1!=ck2 ) rc = FTS5_CORRUPT;

    /* If this is a prefix query, check that the results returned if the
    ** the index is disabled are the same. In both ASC and DESC order. 
    **
    ** This check may only be performed if the hash table is empty. This
    ** is because the hash table only supports a single scan query at
    ** a time, and the multi-iter loop from which this function is called
    ** is already performing such a scan. */
    if( p->nPendingData==0 ){
      if( iIdx>0 && rc==SQLITE_OK ){
        int f = flags|FTS5INDEX_QUERY_TEST_NOIDX;
        ck2 = 0;
        rc = fts5QueryCksum(p, iIdx, zTerm, nTerm, f, &ck2);
        if( rc==SQLITE_OK && ck1!=ck2 ) rc = FTS5_CORRUPT;
      }
      if( iIdx>0 && rc==SQLITE_OK ){
        int f = flags|FTS5INDEX_QUERY_TEST_NOIDX|FTS5INDEX_QUERY_DESC;
        ck2 = 0;
        rc = fts5QueryCksum(p, iIdx, zTerm, nTerm, f, &ck2);
        if( rc==SQLITE_OK && ck1!=ck2 ) rc = FTS5_CORRUPT;
      }
    }

    cksum3 ^= ck1;
    fts5BufferSet(&rc, pPrev, n, (const u8*)z);

    if( rc==SQLITE_OK && cksum3!=expected ){
      rc = FTS5_CORRUPT;
................................................................................
  int iLast
){
  int i;

  /* Now check that the iter.nEmpty leaves following the current leaf
  ** (a) exist and (b) contain no terms. */
  for(i=iFirst; p->rc==SQLITE_OK && i<=iLast; i++){
    Fts5Data *pLeaf = fts5DataRead(p, FTS5_SEGMENT_ROWID(pSeg->iSegid, i));
    if( pLeaf ){
      if( !fts5LeafIsTermless(pLeaf) ) p->rc = FTS5_CORRUPT;
      if( i>=iNoRowid && 0!=fts5LeafFirstRowidOff(pLeaf) ) p->rc = FTS5_CORRUPT;
    }
    fts5DataRelease(pLeaf);
  }
}

static void fts5IntegrityCheckPgidx(Fts5Index *p, Fts5Data *pLeaf){
  int iTermOff = 0;
  int ii;

  Fts5Buffer buf1 = {0,0,0};
  Fts5Buffer buf2 = {0,0,0};

  ii = pLeaf->szLeaf;
  while( ii<pLeaf->nn && p->rc==SQLITE_OK ){
    int res;
    int iOff;
    int nIncr;

    ii += fts5GetVarint32(&pLeaf->p[ii], nIncr);
    iTermOff += nIncr;
    iOff = iTermOff;

    if( iOff>=pLeaf->szLeaf ){
      p->rc = FTS5_CORRUPT;
    }else if( iTermOff==nIncr ){
      int nByte;
      iOff += fts5GetVarint32(&pLeaf->p[iOff], nByte);
      if( (iOff+nByte)>pLeaf->szLeaf ){
        p->rc = FTS5_CORRUPT;
      }else{
        fts5BufferSet(&p->rc, &buf1, nByte, &pLeaf->p[iOff]);
      }
    }else{
      int nKeep, nByte;
      iOff += fts5GetVarint32(&pLeaf->p[iOff], nKeep);
      iOff += fts5GetVarint32(&pLeaf->p[iOff], nByte);
      if( nKeep>buf1.n || (iOff+nByte)>pLeaf->szLeaf ){
        p->rc = FTS5_CORRUPT;
      }else{
        buf1.n = nKeep;
        fts5BufferAppendBlob(&p->rc, &buf1, nByte, &pLeaf->p[iOff]);
      }

      if( p->rc==SQLITE_OK ){
        res = fts5BufferCompare(&buf1, &buf2);
        if( res<=0 ) p->rc = FTS5_CORRUPT;
      }
    }
    fts5BufferSet(&p->rc, &buf2, buf1.n, buf1.p);
  }

  fts5BufferFree(&buf1);
  fts5BufferFree(&buf2);
}

static void fts5IndexIntegrityCheckSegment(
  Fts5Index *p,                   /* FTS5 backend object */
  Fts5StructureSegment *pSeg      /* Segment to check internal consistency */
){
  Fts5Config *pConfig = p->pConfig;
  sqlite3_stmt *pStmt = 0;
................................................................................
  int rc2;
  int iIdxPrevLeaf = pSeg->pgnoFirst-1;
  int iDlidxPrevLeaf = pSeg->pgnoLast;

  if( pSeg->pgnoFirst==0 ) return;

  fts5IndexPrepareStmt(p, &pStmt, sqlite3_mprintf(
      "SELECT segid, term, (pgno>>1), (pgno&1) FROM %Q.'%q_idx' WHERE segid=%d",
      pConfig->zDb, pConfig->zName, pSeg->iSegid
  ));

  /* Iterate through the b-tree hierarchy.  */
  while( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){
    i64 iRow;                     /* Rowid for this leaf */
    Fts5Data *pLeaf;              /* Data for this leaf */


    int nIdxTerm = sqlite3_column_bytes(pStmt, 1);
    const char *zIdxTerm = (const char*)sqlite3_column_text(pStmt, 1);
    int iIdxLeaf = sqlite3_column_int(pStmt, 2);
    int bIdxDlidx = sqlite3_column_int(pStmt, 3);

    /* If the leaf in question has already been trimmed from the segment, 
    ** ignore this b-tree entry. Otherwise, load it into memory. */
    if( iIdxLeaf<pSeg->pgnoFirst ) continue;
    iRow = FTS5_SEGMENT_ROWID(pSeg->iSegid, iIdxLeaf);
    pLeaf = fts5DataRead(p, iRow);
    if( pLeaf==0 ) break;

    /* Check that the leaf contains at least one term, and that it is equal
    ** to or larger than the split-key in zIdxTerm.  Also check that if there
    ** is also a rowid pointer within the leaf page header, it points to a
    ** location before the term.  */
    if( pLeaf->nn<=pLeaf->szLeaf ){

      p->rc = FTS5_CORRUPT;
    }else{
      int iOff;                   /* Offset of first term on leaf */
      int iRowidOff;              /* Offset of first rowid on leaf */
      int nTerm;                  /* Size of term on leaf in bytes */
      int res;                    /* Comparison of term and split-key */

      iOff = fts5LeafFirstTermOff(pLeaf);
      iRowidOff = fts5LeafFirstRowidOff(pLeaf);
      if( iRowidOff>=iOff ){
        p->rc = FTS5_CORRUPT;
      }else{
        iOff += fts5GetVarint32(&pLeaf->p[iOff], nTerm);
        res = memcmp(&pLeaf->p[iOff], zIdxTerm, MIN(nTerm, nIdxTerm));
        if( res==0 ) res = nTerm - nIdxTerm;
        if( res<0 ) p->rc = FTS5_CORRUPT;
      }

      fts5IntegrityCheckPgidx(p, pLeaf);
    }
    fts5DataRelease(pLeaf);
    if( p->rc ) break;


    /* Now check that the iter.nEmpty leaves following the current leaf
    ** (a) exist and (b) contain no terms. */
................................................................................
      for(pDlidx=fts5DlidxIterInit(p, 0, iSegid, iIdxLeaf);
          fts5DlidxIterEof(p, pDlidx)==0;
          fts5DlidxIterNext(p, pDlidx)
      ){

        /* Check any rowid-less pages that occur before the current leaf. */
        for(iPg=iPrevLeaf+1; iPg<fts5DlidxIterPgno(pDlidx); iPg++){
          iKey = FTS5_SEGMENT_ROWID(iSegid, iPg);
          pLeaf = fts5DataRead(p, iKey);
          if( pLeaf ){
            if( fts5LeafFirstRowidOff(pLeaf)!=0 ) p->rc = FTS5_CORRUPT;
            fts5DataRelease(pLeaf);
          }
        }
        iPrevLeaf = fts5DlidxIterPgno(pDlidx);

        /* Check that the leaf page indicated by the iterator really does
        ** contain the rowid suggested by the same. */
        iKey = FTS5_SEGMENT_ROWID(iSegid, iPrevLeaf);
        pLeaf = fts5DataRead(p, iKey);
        if( pLeaf ){
          i64 iRowid;
          int iRowidOff = fts5LeafFirstRowidOff(pLeaf);
          ASSERT_SZLEAF_OK(pLeaf);
          if( iRowidOff>=pLeaf->szLeaf ){
            p->rc = FTS5_CORRUPT;
          }else{
            fts5GetVarint(&pLeaf->p[iRowidOff], (u64*)&iRowid);
            if( iRowid!=fts5DlidxIterRowid(pDlidx) ) p->rc = FTS5_CORRUPT;
          }
          fts5DataRelease(pLeaf);
        }
................................................................................
  for(iLvl=0; iLvl<p->nLevel; iLvl++){
    Fts5StructureLevel *pLvl = &p->aLevel[iLvl];
    sqlite3Fts5BufferAppendPrintf(pRc, pBuf, 
        " {lvl=%d nMerge=%d nSeg=%d", iLvl, pLvl->nMerge, pLvl->nSeg
    );
    for(iSeg=0; iSeg<pLvl->nSeg; iSeg++){
      Fts5StructureSegment *pSeg = &pLvl->aSeg[iSeg];
      sqlite3Fts5BufferAppendPrintf(pRc, pBuf, " {id=%d leaves=%d..%d}", 

          pSeg->iSegid, pSeg->pgnoFirst, pSeg->pgnoLast
      );
    }
    sqlite3Fts5BufferAppendPrintf(pRc, pBuf, "}");
  }
}

/*
................................................................................
** may or may not finish within the buffer. This function appends a text
** representation of the part of the doclist that is present to buffer
** pBuf. 
**
** The return value is the number of bytes read from the input buffer.
*/
static int fts5DecodeDoclist(int *pRc, Fts5Buffer *pBuf, const u8 *a, int n){
  i64 iDocid = 0;
  int iOff = 0;

  if( n>0 ){
    iOff = sqlite3Fts5GetVarint(a, (u64*)&iDocid);
    sqlite3Fts5BufferAppendPrintf(pRc, pBuf, " id=%lld", iDocid);
  }
  while( iOff<n ){
    int nPos;
    int bDummy;
    iOff += fts5GetPoslistSize(&a[iOff], &nPos, &bDummy);
    iOff += fts5DecodePoslist(pRc, pBuf, &a[iOff], MIN(n-iOff, nPos));
    if( iOff<n ){
      i64 iDelta;
      iOff += sqlite3Fts5GetVarint(&a[iOff], (u64*)&iDelta);

      iDocid += iDelta;
      sqlite3Fts5BufferAppendPrintf(pRc, pBuf, " id=%lld", iDocid);
    }
  }

  return iOff;
}

/*
................................................................................
  Fts5Buffer s;                   /* Build up text to return here */
  int rc = SQLITE_OK;             /* Return code */
  int nSpace = 0;

  assert( nArg==2 );
  memset(&s, 0, sizeof(Fts5Buffer));
  iRowid = sqlite3_value_int64(apVal[0]);

  /* Make a copy of the second argument (a blob) in aBlob[]. The aBlob[]
  ** copy is followed by FTS5_DATA_ZERO_PADDING 0x00 bytes, which prevents
  ** buffer overreads even if the record is corrupt.  */
  n = sqlite3_value_bytes(apVal[1]);
  aBlob = sqlite3_value_blob(apVal[1]);

  nSpace = n + FTS5_DATA_ZERO_PADDING;
  a = (u8*)sqlite3Fts5MallocZero(&rc, nSpace);
  if( a==0 ) goto decode_out;
  memcpy(a, aBlob, n);


  fts5DecodeRowid(iRowid, &iSegid, &bDlidx, &iHeight, &iPgno);

  fts5DebugRowid(&rc, &s, iRowid);
  if( bDlidx ){
    Fts5Data dlidx;
    Fts5DlidxLvl lvl;

    dlidx.p = a;
    dlidx.nn = n;

    memset(&lvl, 0, sizeof(Fts5DlidxLvl));
    lvl.pData = &dlidx;
    lvl.iLeafPgno = iPgno;

    for(fts5DlidxLvlNext(&lvl); lvl.bEof==0; fts5DlidxLvlNext(&lvl)){
      sqlite3Fts5BufferAppendPrintf(&rc, &s, 
................................................................................
  }else if( iSegid==0 ){
    if( iRowid==FTS5_AVERAGES_ROWID ){
      /* todo */
    }else{
      fts5DecodeStructure(&rc, &s, a, n);
    }
  }else{
    Fts5Buffer term;              /* Current term read from page */
    int szLeaf;                   /* Offset of pgidx in a[] */
    int iPgidxOff;
    int iPgidxPrev = 0;           /* Previous value read from pgidx */
    int iTermOff = 0;
    int iRowidOff = 0;
    int iOff;
    int nDoclist;

    memset(&term, 0, sizeof(Fts5Buffer));

    if( n<4 ){



      sqlite3Fts5BufferSet(&rc, &s, 8, (const u8*)"corrupt");
      goto decode_out;
    }else{
      iRowidOff = fts5GetU16(&a[0]);
      iPgidxOff = szLeaf = fts5GetU16(&a[2]);
      if( iPgidxOff<n ){
        fts5GetVarint32(&a[iPgidxOff], iTermOff);
      }
    }

    /* Decode the position list tail at the start of the page */
    if( iRowidOff!=0 ){
      iOff = iRowidOff;
    }else if( iTermOff!=0 ){
      iOff = iTermOff;
    }else{
      iOff = szLeaf;
    }
    fts5DecodePoslist(&rc, &s, &a[4], iOff-4);



    /* Decode any more doclist data that appears on the page before the
    ** first term. */
    nDoclist = (iTermOff ? iTermOff : szLeaf) - iOff;
    fts5DecodeDoclist(&rc, &s, &a[iOff], nDoclist);

    while( iPgidxOff<n ){
      int bFirst = (iPgidxOff==szLeaf);     /* True for first term on page */
      int nByte;                            /* Bytes of data */
      int iEnd;
      

      iPgidxOff += fts5GetVarint32(&a[iPgidxOff], nByte);
      iPgidxPrev += nByte;
      iOff = iPgidxPrev;

      if( iPgidxOff<n ){
        fts5GetVarint32(&a[iPgidxOff], nByte);
        iEnd = iPgidxPrev + nByte;
      }else{
        iEnd = szLeaf;
      }

      if( bFirst==0 ){
        iOff += fts5GetVarint32(&a[iOff], nByte);
        term.n = nByte;
      }
      iOff += fts5GetVarint32(&a[iOff], nByte);
      fts5BufferAppendBlob(&rc, &term, nByte, &a[iOff]);
      iOff += nByte;

      sqlite3Fts5BufferAppendPrintf(
          &rc, &s, " term=%.*s", term.n, (const char*)term.p
      );
      iOff += fts5DecodeDoclist(&rc, &s, &a[iOff], iEnd-iOff);


    }

    fts5BufferFree(&term);
  }
  
 decode_out:
  sqlite3_free(a);
  if( rc==SQLITE_OK ){
    sqlite3_result_text(pCtx, (const char*)s.p, s.n, SQLITE_TRANSIENT);
................................................................................
  const char *zArg;
  if( nArg==0 ){
    sqlite3_result_error(pCtx, "should be: fts5_rowid(subject, ....)", -1);
  }else{
    zArg = (const char*)sqlite3_value_text(apVal[0]);
    if( 0==sqlite3_stricmp(zArg, "segment") ){
      i64 iRowid;
      int segid, pgno;
      if( nArg!=3 ){
        sqlite3_result_error(pCtx, 
            "should be: fts5_rowid('segment', segid, pgno))", -1
        );
      }else{
        segid = sqlite3_value_int(apVal[1]);

        pgno = sqlite3_value_int(apVal[2]);
        iRowid = FTS5_SEGMENT_ROWID(segid, pgno);
        sqlite3_result_int64(pCtx, iRowid);
      }
    }else{
      sqlite3_result_error(pCtx, 
        "first arg to fts5_rowid() must be 'segment'" , -1


      );
    }
  }
}

/*
** This is called as part of registering the FTS5 module with database

** structures should not be corrupt. Otherwise, true. If it is false, extra
** assert() conditions in the fts5 code are activated - conditions that are
** only true if it is guaranteed that the fts5 database is not corrupt.
*/
int sqlite3_fts5_may_be_corrupt = 1;


typedef struct Fts5Table Fts5Table;

typedef struct Fts5Cursor Fts5Cursor;
typedef struct Fts5Auxiliary Fts5Auxiliary;
typedef struct Fts5Auxdata Fts5Auxdata;

typedef struct Fts5TokenizerModule Fts5TokenizerModule;

/*
** NOTES ON TRANSACTIONS: 
**
** SQLite invokes the following virtual table methods as transactions are 
** opened and closed by the user:
................................................................................
  }else if( 0==sqlite3_stricmp("optimize", z) ){
    rc = sqlite3Fts5StorageOptimize(pTab->pStorage);
  }else if( 0==sqlite3_stricmp("merge", z) ){
    int nMerge = sqlite3_value_int(pVal);
    rc = sqlite3Fts5StorageMerge(pTab->pStorage, nMerge);
  }else if( 0==sqlite3_stricmp("integrity-check", z) ){
    rc = sqlite3Fts5StorageIntegrity(pTab->pStorage);




  }else{
    rc = sqlite3Fts5IndexLoadConfig(pTab->pIndex);
    if( rc==SQLITE_OK ){
      rc = sqlite3Fts5ConfigSetValue(pTab->pConfig, z, pVal, &bError);
    }
    if( rc==SQLITE_OK ){
      if( bError ){

** structures should not be corrupt. Otherwise, true. If it is false, extra
** assert() conditions in the fts5 code are activated - conditions that are
** only true if it is guaranteed that the fts5 database is not corrupt.
*/
int sqlite3_fts5_may_be_corrupt = 1;


typedef struct Fts5Auxdata Fts5Auxdata;
typedef struct Fts5Auxiliary Fts5Auxiliary;
typedef struct Fts5Cursor Fts5Cursor;
typedef struct Fts5Sorter Fts5Sorter;
typedef struct Fts5Table Fts5Table;

typedef struct Fts5TokenizerModule Fts5TokenizerModule;

/*
** NOTES ON TRANSACTIONS: 
**
** SQLite invokes the following virtual table methods as transactions are 
** opened and closed by the user:
................................................................................
  }else if( 0==sqlite3_stricmp("optimize", z) ){
    rc = sqlite3Fts5StorageOptimize(pTab->pStorage);
  }else if( 0==sqlite3_stricmp("merge", z) ){
    int nMerge = sqlite3_value_int(pVal);
    rc = sqlite3Fts5StorageMerge(pTab->pStorage, nMerge);
  }else if( 0==sqlite3_stricmp("integrity-check", z) ){
    rc = sqlite3Fts5StorageIntegrity(pTab->pStorage);
#ifdef SQLITE_DEBUG
  }else if( 0==sqlite3_stricmp("prefix-index", z) ){
    pConfig->bPrefixIndex = sqlite3_value_int(pVal);
#endif
  }else{
    rc = sqlite3Fts5IndexLoadConfig(pTab->pIndex);
    if( rc==SQLITE_OK ){
      rc = sqlite3Fts5ConfigSetValue(pTab->pConfig, z, pVal, &bError);
    }
    if( rc==SQLITE_OK ){
      if( bError ){

}
do_execsql_test 2.1 {
  INSERT INTO t1 VALUES('a b c', 'd e f');
}

do_test 2.2 {
  execsql { SELECT fts5_decode(id, block) FROM t1_data WHERE id==10 }
} {/{{structure} {lvl=0 nMerge=0 nSeg=1 {id=[0123456789]* h=0 leaves=1..1}}}/}

foreach w {a b c d e f} {
  do_execsql_test 2.3.$w.asc {
    SELECT rowid FROM t1 WHERE t1 MATCH $w;
  } {1}
  do_execsql_test 2.3.$w.desc {
    SELECT rowid FROM t1 WHERE t1 MATCH $w ORDER BY rowid DESC;
................................................................................
  do_execsql_test 5.$i.1 { INSERT INTO t1 VALUES($x, $y) }
  do_execsql_test 5.$i.2 { INSERT INTO t1(t1) VALUES('integrity-check') }
  if {[set_test_counter errors]} break
}

#-------------------------------------------------------------------------
#
breakpoint
reset_db
do_execsql_test 6.0 {
  CREATE VIRTUAL TABLE t1 USING fts5(x,y);
  INSERT INTO t1(t1, rank) VALUES('pgsz', 32);
}

do_execsql_test 6.1 {
................................................................................
      set y [doc]
      set z [doc]
      set rowid [expr int(rand() * 100)]
      execsql { REPLACE INTO t1(rowid,x,y,z) VALUES($rowid, $x, $y, $z) }
    }
    execsql { INSERT INTO t1(t1) VALUES('integrity-check'); }
  } {}

}

#-------------------------------------------------------------------------
#
reset_db
do_execsql_test 8.0 {
  CREATE VIRTUAL TABLE t1 USING fts5(x, prefix="1,2,3");

}
do_execsql_test 2.1 {
  INSERT INTO t1 VALUES('a b c', 'd e f');
}

do_test 2.2 {
  execsql { SELECT fts5_decode(id, block) FROM t1_data WHERE id==10 }
} {/{{structure} {lvl=0 nMerge=0 nSeg=1 {id=[0123456789]* leaves=1..1}}}/}

foreach w {a b c d e f} {
  do_execsql_test 2.3.$w.asc {
    SELECT rowid FROM t1 WHERE t1 MATCH $w;
  } {1}
  do_execsql_test 2.3.$w.desc {
    SELECT rowid FROM t1 WHERE t1 MATCH $w ORDER BY rowid DESC;
................................................................................
  do_execsql_test 5.$i.1 { INSERT INTO t1 VALUES($x, $y) }
  do_execsql_test 5.$i.2 { INSERT INTO t1(t1) VALUES('integrity-check') }
  if {[set_test_counter errors]} break
}

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

reset_db
do_execsql_test 6.0 {
  CREATE VIRTUAL TABLE t1 USING fts5(x,y);
  INSERT INTO t1(t1, rank) VALUES('pgsz', 32);
}

do_execsql_test 6.1 {
................................................................................
      set y [doc]
      set z [doc]
      set rowid [expr int(rand() * 100)]
      execsql { REPLACE INTO t1(rowid,x,y,z) VALUES($rowid, $x, $y, $z) }
    }
    execsql { INSERT INTO t1(t1) VALUES('integrity-check'); }
  } {}
  if {[set_test_counter errors]} break
}

#-------------------------------------------------------------------------
#
reset_db
do_execsql_test 8.0 {
  CREATE VIRTUAL TABLE t1 USING fts5(x, prefix="1,2,3");

        }
      }
      if {$bMatch} { lappend ret $rowid }
    }
    return $ret
  }




  
  foreach {bAsc sql} {
    1 {SELECT rowid FROM t1 WHERE t1 MATCH $prefix}
    0 {SELECT rowid FROM t1 WHERE t1 MATCH $prefix ORDER BY rowid DESC}
  } {
    foreach {tn prefix} {
      1  {a*} 2 {ab*} 3 {abc*} 4 {abcd*} 5 {abcde*} 

        }
      }
      if {$bMatch} { lappend ret $rowid }
    }
    return $ret
  }

  do_execsql_test $T.integrity {
    INSERT INTO t1(t1) VALUES('integrity-check');
  }
  
  foreach {bAsc sql} {
    1 {SELECT rowid FROM t1 WHERE t1 MATCH $prefix}
    0 {SELECT rowid FROM t1 WHERE t1 MATCH $prefix ORDER BY rowid DESC}
  } {
    foreach {tn prefix} {
      1  {a*} 2 {ab*} 3 {abc*} 4 {abcd*} 5 {abcde*} 

  finish_test
  return
}

do_execsql_test 1.1 {
  CREATE VIRTUAL TABLE ft1 USING fts5(x);
  SELECT * FROM ft1_config;
} {version 3}

do_execsql_test 1.2 {
  INSERT INTO ft1(ft1, rank) VALUES('pgsz', 32);
  SELECT * FROM ft1_config;
} {pgsz 32 version 3}

do_execsql_test 1.3 {
  INSERT INTO ft1(ft1, rank) VALUES('pgsz', 64);
  SELECT * FROM ft1_config;
} {pgsz 64 version 3}

#--------------------------------------------------------------------------
# Test the logic for parsing the rank() function definition.
#
foreach {tn defn} {
  1 "fname()"
  2 "fname(1)"

  finish_test
  return
}

do_execsql_test 1.1 {
  CREATE VIRTUAL TABLE ft1 USING fts5(x);
  SELECT * FROM ft1_config;
} {version 4}

do_execsql_test 1.2 {
  INSERT INTO ft1(ft1, rank) VALUES('pgsz', 32);
  SELECT * FROM ft1_config;
} {pgsz 32 version 4}

do_execsql_test 1.3 {
  INSERT INTO ft1(ft1, rank) VALUES('pgsz', 64);
  SELECT * FROM ft1_config;
} {pgsz 64 version 4}

#--------------------------------------------------------------------------
# Test the logic for parsing the rank() function definition.
#
foreach {tn defn} {
  1 "fname()"
  2 "fname(1)"

db_save

do_execsql_test 1.2 { INSERT INTO t1(t1) VALUES('integrity-check') }
set segid [lindex [fts5_level_segids t1] 0]

do_test 1.3 {
  execsql {
    DELETE FROM t1_data WHERE rowid = fts5_rowid('segment', $segid, 0, 4);
  }
  catchsql { INSERT INTO t1(t1) VALUES('integrity-check') }
} {1 {database disk image is malformed}}

do_test 1.4 {
  db_restore_and_reopen
  execsql {
    UPDATE t1_data set block = X'00000000' || substr(block, 5) WHERE
    rowid = fts5_rowid('segment', $segid, 0, 4);
  }
  catchsql { INSERT INTO t1(t1) VALUES('integrity-check') }
} {1 {database disk image is malformed}}

db_restore_and_reopen
#db eval {SELECT rowid, fts5_decode(rowid, block) aS r FROM t1_data} {puts $r}

db_save

do_execsql_test 1.2 { INSERT INTO t1(t1) VALUES('integrity-check') }
set segid [lindex [fts5_level_segids t1] 0]

do_test 1.3 {
  execsql {
    DELETE FROM t1_data WHERE rowid = fts5_rowid('segment', $segid, 4);
  }
  catchsql { INSERT INTO t1(t1) VALUES('integrity-check') }
} {1 {database disk image is malformed}}

do_test 1.4 {
  db_restore_and_reopen
  execsql {
    UPDATE t1_data set block = X'00000000' || substr(block, 5) WHERE
    rowid = fts5_rowid('segment', $segid, 4);
  }
  catchsql { INSERT INTO t1(t1) VALUES('integrity-check') }
} {1 {database disk image is malformed}}

db_restore_and_reopen
#db eval {SELECT rowid, fts5_decode(rowid, block) aS r FROM t1_data} {puts $r}

      if {$res == "1 {database disk image is malformed}"} {incr nCorrupt}
      set {} 1
    } {1}

    execsql ROLLBACK
  }

  do_test 4.$tn.x { expr $nCorrupt>0 } 1
}

}

set doc [string repeat "A B C " 1000]
do_execsql_test 4.0 {
  CREATE VIRTUAL TABLE x5 USING fts5(tt);
  INSERT INTO x5(x5, rank) VALUES('pgsz', 32);
  WITH ii(i) AS (SELECT 1 UNION ALL SELECT i+1 FROM ii WHERE i<10) 
  INSERT INTO x5 SELECT $doc FROM ii;
}

foreach {tn hdr} {
................................................................................
  1 "\x00\x01"
} {
  set tn2 0
  set nCorrupt 0
  foreach rowid [db eval {SELECT rowid FROM x5_data WHERE rowid>10}] {
    if {$rowid & $mask} continue
    incr tn2
    do_test 4.$tn.$tn2 {
      execsql BEGIN

      set fd [db incrblob main x5_data block $rowid]
      fconfigure $fd -encoding binary -translation binary
      puts -nonewline $fd $hdr
      close $fd

................................................................................

    execsql ROLLBACK
  }
}

#--------------------------------------------------------------------
reset_db
do_execsql_test 5.1 {
  CREATE VIRTUAL TABLE x5 USING fts5(tt);
  INSERT INTO x5 VALUES('a');
  INSERT INTO x5 VALUES('a a');
  INSERT INTO x5 VALUES('a a a');
  INSERT INTO x5 VALUES('a a a a');

  UPDATE x5_docsize SET sz = X'' WHERE id=3;
}
proc colsize {cmd i} { 
  $cmd xColumnSize $i
}
sqlite3_fts5_create_function db colsize colsize

do_catchsql_test 5.2 {
  SELECT colsize(x5, 0) FROM x5 WHERE x5 MATCH 'a'
} {1 SQLITE_CORRUPT_VTAB}


sqlite3_fts5_may_be_corrupt 0
finish_test

      if {$res == "1 {database disk image is malformed}"} {incr nCorrupt}
      set {} 1
    } {1}

    execsql ROLLBACK
  }

  # do_test 4.$tn.x { expr $nCorrupt>0 } 1
}

}

set doc [string repeat "A B C " 1000]
do_execsql_test 5.0 {
  CREATE VIRTUAL TABLE x5 USING fts5(tt);
  INSERT INTO x5(x5, rank) VALUES('pgsz', 32);
  WITH ii(i) AS (SELECT 1 UNION ALL SELECT i+1 FROM ii WHERE i<10) 
  INSERT INTO x5 SELECT $doc FROM ii;
}

foreach {tn hdr} {
................................................................................
  1 "\x00\x01"
} {
  set tn2 0
  set nCorrupt 0
  foreach rowid [db eval {SELECT rowid FROM x5_data WHERE rowid>10}] {
    if {$rowid & $mask} continue
    incr tn2
    do_test 5.$tn.$tn2 {
      execsql BEGIN

      set fd [db incrblob main x5_data block $rowid]
      fconfigure $fd -encoding binary -translation binary
      puts -nonewline $fd $hdr
      close $fd

................................................................................

    execsql ROLLBACK
  }
}

#--------------------------------------------------------------------
reset_db
do_execsql_test 6.1 {
  CREATE VIRTUAL TABLE x5 USING fts5(tt);
  INSERT INTO x5 VALUES('a');
  INSERT INTO x5 VALUES('a a');
  INSERT INTO x5 VALUES('a a a');
  INSERT INTO x5 VALUES('a a a a');

  UPDATE x5_docsize SET sz = X'' WHERE id=3;
}
proc colsize {cmd i} { 
  $cmd xColumnSize $i
}
sqlite3_fts5_create_function db colsize colsize

do_catchsql_test 6.2 {
  SELECT colsize(x5, 0) FROM x5 WHERE x5 MATCH 'a'
} {1 SQLITE_CORRUPT_VTAB}


sqlite3_fts5_may_be_corrupt 0
finish_test

# If SQLITE_ENABLE_FTS5 is defined, omit this file.
ifcapable !fts5 {
  finish_test
  return
}
sqlite3_fts5_may_be_corrupt 1














# Create a simple FTS5 table containing 100 documents. Each document 
# contains 10 terms, each of which start with the character "x".
#
expr srand(0)
db func rnddoc fts5_rnddoc
do_execsql_test 1.0 {
  CREATE VIRTUAL TABLE t1 USING fts5(x);
  INSERT INTO t1(t1, rank) VALUES('pgsz', 64);
  WITH ii(i) AS (SELECT 1 UNION SELECT i+1 FROM ii WHERE i<100)
  INSERT INTO t1 SELECT rnddoc(10) FROM ii;
}
set mask [expr 31 << 31]

do_test 1.1 {
  # Pick out the rowid of the right-most b-tree leaf in the new segment.
  set rowid [db one {
    SELECT max(rowid) FROM t1_data WHERE ((rowid>>31) & 0x0F)==1
  }]
  set L [db one {SELECT length(block) FROM t1_data WHERE rowid = $rowid}]
................................................................................
  SELECT length(block) FROM t2_data WHERE id=1;
} {6}
do_execsql_test 2.2 {
  INSERT INTO t2 VALUES(rnddoc(10));
  SELECT length(block) FROM t2_data WHERE id=1;
} {2}
































































































































































































































































sqlite3_fts5_may_be_corrupt 0
finish_test

# If SQLITE_ENABLE_FTS5 is defined, omit this file.
ifcapable !fts5 {
  finish_test
  return
}
sqlite3_fts5_may_be_corrupt 1

proc create_t1 {} {
  expr srand(0)
  db func rnddoc fts5_rnddoc
  db eval {
    CREATE VIRTUAL TABLE t1 USING fts5(x);
    INSERT INTO t1(t1, rank) VALUES('pgsz', 64);
    WITH ii(i) AS (SELECT 1 UNION SELECT i+1 FROM ii WHERE i<100)
      INSERT INTO t1 SELECT rnddoc(10) FROM ii;
  }
}

if 1 {

# Create a simple FTS5 table containing 100 documents. Each document 
# contains 10 terms, each of which start with the character "x".
#


do_test 1.0 { create_t1 } {}







do_test 1.1 {
  # Pick out the rowid of the right-most b-tree leaf in the new segment.
  set rowid [db one {
    SELECT max(rowid) FROM t1_data WHERE ((rowid>>31) & 0x0F)==1
  }]
  set L [db one {SELECT length(block) FROM t1_data WHERE rowid = $rowid}]
................................................................................
  SELECT length(block) FROM t2_data WHERE id=1;
} {6}
do_execsql_test 2.2 {
  INSERT INTO t2 VALUES(rnddoc(10));
  SELECT length(block) FROM t2_data WHERE id=1;
} {2}


#-------------------------------------------------------------------------
# Test that missing leaf pages are recognized as corruption.
#
reset_db
do_test 3.0 { create_t1 } {}

do_execsql_test 3.1 {
  SELECT count(*) FROM t1_data;
} {105}

proc do_3_test {tn} {
  set i 0
  foreach ::rowid [db eval "SELECT rowid FROM t1_data WHERE rowid>100"] {
    incr i
    do_test $tn.$i {
      db eval BEGIN
      db eval {DELETE FROM t1_data WHERE rowid = $::rowid}
      list [
        catch { db eval {SELECT rowid FROM t1 WHERE t1 MATCH 'x*'} } msg
      ] $msg
    } {1 {database disk image is malformed}}
    catch { db eval ROLLBACK }
  }
}

do_3_test 3.2

do_execsql_test 3.3 {
  INSERT INTO t1(t1, rank) VALUES('pgsz', 32);
  INSERT INTO t1 SELECT x FROM t1;
  INSERT INTO t1(t1) VALUES('optimize');
} {}

do_3_test 3.4

do_test 3.5 {
  execsql { 
    DELETE FROM t1;
    INSERT INTO t1(t1, rank) VALUES('pgsz', 40);
  }
  for {set i 0} {$i < 1000} {incr i} {
    set rnd [expr int(rand() * 1000)]
    set doc [string repeat "x$rnd " [expr int(rand() * 3) + 1]]
    execsql { INSERT INTO t1(rowid, x) VALUES($i, $doc) }
  }
} {}

do_3_test 3.6

do_test 3.7 {
  execsql {
    INSERT INTO t1(t1, rank) VALUES('pgsz', 40);
    INSERT INTO t1 SELECT x FROM t1;
    INSERT INTO t1(t1) VALUES('optimize');
  }
} {}

do_3_test 3.8

do_test 3.9 {
  execsql { 
    DELETE FROM t1;
    INSERT INTO t1(t1, rank) VALUES('pgsz', 32);
  }
  for {set i 0} {$i < 100} {incr i} {
    set rnd [expr int(rand() * 100)]
    set doc "x[string repeat $rnd 20]"
    execsql { INSERT INTO t1(rowid, x) VALUES($i, $doc) }
  }
} {}

do_3_test 3.10

#-------------------------------------------------------------------------
# Test that segments that end unexpectedly are identified as corruption.
#
reset_db
do_test 4.0 {
  execsql { 
    CREATE VIRTUAL TABLE t1 USING fts5(x);
    INSERT INTO t1(t1, rank) VALUES('pgsz', 32);
  }
  for {set i 0} {$i < 100} {incr i} {
    set rnd [expr int(rand() * 100)]
    set doc "x[string repeat $rnd 20]"
    execsql { INSERT INTO t1(rowid, x) VALUES($i, $doc) }
  }
  execsql { INSERT INTO t1(t1) VALUES('optimize') }
} {}

set nErr 0
for {set i 1} {1} {incr i} {
  set struct [db one {SELECT block FROM t1_data WHERE id=10}]
  binary scan $struct c* var
  set end [lindex $var end]
  if {$end<=$i} break
  lset var end [expr $end - $i]
  set struct [binary format c* $var]
  db eval {
    BEGIN;
    UPDATE t1_data SET block = $struct WHERE id=10;
  }
  do_test 4.1.$i {
    incr nErr [catch { db eval { SELECT rowid FROM t1 WHERE t1 MATCH 'x*' } }]
    set {} {}
  } {}
  catch { db eval ROLLBACK }
}
do_test 4.1.x { expr $nErr>45 } 1

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

# The first argument passed to this command must be a binary blob 
# containing an FTS5 leaf page. This command returns a copy of this
# blob, with the pgidx of the leaf page replaced by a single varint
# containing value $iVal.
#
proc rewrite_pgidx {blob iVal} {
  binary scan $blob SS off1 szLeaf
  if {$iVal<0 || $iVal>=128} {
    error "$iVal out of range!"
  } else {
    set pgidx [binary format c $iVal]
  }

  binary format a${szLeaf}a* $blob $pgidx
}

reset_db
do_execsql_test 5.1 {
  CREATE VIRTUAL TABLE x1 USING fts5(x);
  INSERT INTO x1(x1, rank) VALUES('pgsz', 40);
  BEGIN;
  INSERT INTO x1 VALUES('xaaa xabb xccc xcdd xeee xeff xggg xghh xiii xijj');
  INSERT INTO x1 SELECT x FROM x1;
  INSERT INTO x1 SELECT x FROM x1;
  INSERT INTO x1 SELECT x FROM x1;
  INSERT INTO x1 SELECT x FROM x1;
  INSERT INTO x1(x1) VALUES('optimize');
  COMMIT;
}

#db eval { SELECT fts5_decode(id, block) b from x1_data } { puts $b }
#
db func rewrite_pgidx rewrite_pgidx  
set i 0
foreach rowid [db eval {SELECT rowid FROM x1_data WHERE rowid>100}] {
  foreach val {2 100} {
    do_test 5.2.$val.[incr i] {
      catchsql {
        BEGIN;
        UPDATE x1_data SET block=rewrite_pgidx(block, $val) WHERE id=$rowid;
        SELECT rowid FROM x1 WHERE x1 MATCH 'xa*';
        SELECT rowid FROM x1 WHERE x1 MATCH 'xb*';
        SELECT rowid FROM x1 WHERE x1 MATCH 'xc*';
        SELECT rowid FROM x1 WHERE x1 MATCH 'xd*';
        SELECT rowid FROM x1 WHERE x1 MATCH 'xe*';
        SELECT rowid FROM x1 WHERE x1 MATCH 'xf*';
        SELECT rowid FROM x1 WHERE x1 MATCH 'xg*';
        SELECT rowid FROM x1 WHERE x1 MATCH 'xh*';
        SELECT rowid FROM x1 WHERE x1 MATCH 'xi*';
      }
      set {} {}
    } {}
    catch { db eval ROLLBACK }
  }
}

}

#------------------------------------------------------------------------
#
reset_db
do_execsql_test 6.1.0 {
  CREATE VIRTUAL TABLE t1 USING fts5(a);
  INSERT INTO t1 VALUES('bbbbb ccccc');
  SELECT quote(block) FROM t1_data WHERE rowid>100;
} {X'000000180630626262626201020201056363636363010203040A'}
do_execsql_test 6.1.1 {
  UPDATE t1_data SET block = 
  X'000000180630626262626201020201056161616161010203040A'
  WHERE rowid>100;
}
do_catchsql_test 6.1.2 {
  INSERT INTO t1(t1) VALUES('integrity-check');
} {1 {database disk image is malformed}}

#-------
reset_db
do_execsql_test 6.2.0 {
  CREATE VIRTUAL TABLE t1 USING fts5(a);
  INSERT INTO t1(t1, rank) VALUES('pgsz', 32);
  INSERT INTO t1 VALUES('aa bb cc dd ee');
  SELECT pgno, quote(term) FROM t1_idx;
} {2 X'' 4 X'3064'}
do_execsql_test 6.2.1 {
  UPDATE t1_idx SET term = X'3065' WHERE pgno=4;
}
do_catchsql_test 6.2.2 {
  INSERT INTO t1(t1) VALUES('integrity-check');
} {1 {database disk image is malformed}}

#-------
reset_db
do_execsql_test 6.3.0 {
  CREATE VIRTUAL TABLE t1 USING fts5(a);
  INSERT INTO t1 VALUES('abc abcdef abcdefghi');
  SELECT quote(block) FROM t1_data WHERE id>100;
}    {X'0000001C043061626301020204036465660102030703676869010204040808'}
do_execsql_test 6.3.1 {
  BEGIN;
    UPDATE t1_data SET block = 
      X'0000001C043061626301020204036465660102035003676869010204040808'
      ------------------------------------------^^---------------------
    WHERE id>100;
}
do_catchsql_test 6.3.2 {
  INSERT INTO t1(t1) VALUES('integrity-check');
} {1 {database disk image is malformed}}
do_execsql_test 6.3.3 {
  ROLLBACK;
  BEGIN;
    UPDATE t1_data SET block = 
      X'0000001C043061626301020204036465660102030750676869010204040808'
      --------------------------------------------^^-------------------
    WHERE id>100;
}
do_catchsql_test 6.3.3 {
  INSERT INTO t1(t1) VALUES('integrity-check');
} {1 {database disk image is malformed}}
do_execsql_test 6.3.4 {
  ROLLBACK;
  BEGIN;
    UPDATE t1_data SET block = 
      X'0000001C043061626301020204036465660102030707676869010204040850'
      --------------------------------------------------------------^^-
    WHERE id>100;
}
do_catchsql_test 6.3.5 {
  INSERT INTO t1(t1) VALUES('integrity-check');
} {1 {database disk image is malformed}}
do_execsql_test 6.3.6 {
  ROLLBACK;
  BEGIN;
    UPDATE t1_data SET block = 
      X'0000001C503061626301020204036465660102030707676869010204040808'
      ----------^^-----------------------------------------------------
    WHERE id>100;
}
do_catchsql_test 6.3.5 {
  INSERT INTO t1(t1) VALUES('integrity-check');
} {1 {database disk image is malformed}}

sqlite3_fts5_may_be_corrupt 0
finish_test

  return
}

if { $tcl_platform(wordSize)<8 } {
  finish_test
  return
}



proc do_fb_test {tn sql res} {
  set res2 [lsort -integer -decr $res]
  uplevel [list do_execsql_test $tn.1 $sql $res]
  uplevel [list do_execsql_test $tn.2 "$sql ORDER BY rowid DESC" $res2]
}

................................................................................
  breakpoint
  do_execsql_test $tn.2 {
    SELECT rowid FROM t1 WHERE t1 MATCH 'b AND a' ORDER BY rowid DESC
  } {1}
}

do_dlidx_test2 2.1 [expr 20] [expr 1<<57] [expr (1<<57) + 128]
































































finish_test

  return
}

if { $tcl_platform(wordSize)<8 } {
  finish_test
  return
}

if 1 {

proc do_fb_test {tn sql res} {
  set res2 [lsort -integer -decr $res]
  uplevel [list do_execsql_test $tn.1 $sql $res]
  uplevel [list do_execsql_test $tn.2 "$sql ORDER BY rowid DESC" $res2]
}

................................................................................
  breakpoint
  do_execsql_test $tn.2 {
    SELECT rowid FROM t1 WHERE t1 MATCH 'b AND a' ORDER BY rowid DESC
  } {1}
}

do_dlidx_test2 2.1 [expr 20] [expr 1<<57] [expr (1<<57) + 128]

}

#--------------------------------------------------------------------
#
reset_db

set ::vocab [list \
  IteratorpItercurrentlypointstothefirstrowidofadoclist \
  Thereisadoclistindexassociatedwiththefinaltermonthecurrent \
  pageIfthecurrenttermisthelasttermonthepageloadthe \
  doclistindexfromdiskandinitializeaniteratoratpIterpDlidx \
  IteratorpItercurrentlypointstothefirstrowidofadoclist \
  Thereisadoclistindexassociatedwiththefinaltermonthecurrent \
  pageIfthecurrenttermisthelasttermonthepageloadthe \
  doclistindexfromdiskandinitializeaniteratoratpIterpDlidx \
]
proc rnddoc {} {
  global vocab
  set nVocab [llength $vocab]
  set ret [list]
  for {set i 0} {$i < 64} {incr i} {
    lappend ret [lindex $vocab [expr $i % $nVocab]]
  }
  set ret
}
db func rnddoc rnddoc

do_execsql_test 3.1 {
  CREATE VIRTUAL TABLE abc USING fts5(a);
  INSERT INTO abc(abc, rank) VALUES('pgsz', 32);

  INSERT INTO abc VALUES ( rnddoc() );
  INSERT INTO abc VALUES ( rnddoc() );
  INSERT INTO abc VALUES ( rnddoc() );
  INSERT INTO abc VALUES ( rnddoc() );

  INSERT INTO abc SELECT rnddoc() FROM abc;
  INSERT INTO abc SELECT rnddoc() FROM abc;
}



do_execsql_test 3.2 {
  SELECT rowid FROM abc WHERE abc 
  MATCH 'IteratorpItercurrentlypointstothefirstrowidofadoclist' 
  ORDER BY rowid DESC;
} {16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1}

do_execsql_test 3.2 {
  INSERT INTO abc(abc) VALUES('integrity-check');
  INSERT INTO abc(abc) VALUES('optimize');
  INSERT INTO abc(abc) VALUES('integrity-check');
}

set v [lindex $vocab 0]
set i 0
foreach v $vocab {
  do_execsql_test 3.3.[incr i] {
    SELECT rowid FROM abc WHERE abc MATCH $v
  } {1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16}
}


finish_test

#*************************************************************************
#
# This file is focused on OOM errors.
#

source [file join [file dirname [info script]] fts5_common.tcl]
source $testdir/malloc_common.tcl
set testprefix fts5fault2

# If SQLITE_ENABLE_FTS3 is defined, omit this file.
ifcapable !fts5 {
  finish_test
  return
}



#-------------------------------------------------------------------------
# Test fault-injection on a query that uses xColumnSize() on columnsize=0
# table.
#
do_execsql_test 1.0 {
  CREATE VIRTUAL TABLE t1 USING fts5(x, columnsize=0);
................................................................................

fts5_aux_test_functions db
do_faultsim_test 1 -faults oom* -body {
  execsql { SELECT fts5_test_columnsize(t1) FROM t1 WHERE t1 MATCH 'b' }
} -test {
  faultsim_test_result {0 {7 4 10}} {1 SQLITE_NOMEM}
}













































finish_test

#*************************************************************************
#
# This file is focused on OOM errors.
#

source [file join [file dirname [info script]] fts5_common.tcl]
source $testdir/malloc_common.tcl
set testprefix fts5fault7

# If SQLITE_ENABLE_FTS3 is defined, omit this file.
ifcapable !fts5 {
  finish_test
  return
}

if 1 {

#-------------------------------------------------------------------------
# Test fault-injection on a query that uses xColumnSize() on columnsize=0
# table.
#
do_execsql_test 1.0 {
  CREATE VIRTUAL TABLE t1 USING fts5(x, columnsize=0);
................................................................................

fts5_aux_test_functions db
do_faultsim_test 1 -faults oom* -body {
  execsql { SELECT fts5_test_columnsize(t1) FROM t1 WHERE t1 MATCH 'b' }
} -test {
  faultsim_test_result {0 {7 4 10}} {1 SQLITE_NOMEM}
}

}

#-------------------------------------------------------------------------
# Test fault-injection when a segment is promoted.
#
do_execsql_test 1.0 {
  CREATE VIRTUAL TABLE t2 USING fts5(a);
  INSERT INTO t2(t2, rank) VALUES('automerge', 0);
  INSERT INTO t2(t2, rank) VALUES('crisismerge', 4);
  INSERT INTO t2(t2, rank) VALUES('pgsz', 40);

  INSERT INTO t2 VALUES('a b c');
  INSERT INTO t2 VALUES('d e f');
  INSERT INTO t2 VALUES('f e d');
  INSERT INTO t2 VALUES('c b a');

  INSERT INTO t2 VALUES('a b c');
  INSERT INTO t2 VALUES('d e f');
  INSERT INTO t2 VALUES('f e d');
  INSERT INTO t2 VALUES('c b a');
} {}

faultsim_save_and_close
do_faultsim_test 1 -faults oom-t* -prep {
  faultsim_restore_and_reopen
  db eval {
    BEGIN;
    INSERT INTO t2 VALUES('c d c g g f');
    INSERT INTO t2 VALUES('c d g b f d');
    INSERT INTO t2 VALUES('c c f d e d');
    INSERT INTO t2 VALUES('e a f c e f');
    INSERT INTO t2 VALUES('c g f b b d');
    INSERT INTO t2 VALUES('d a g a b b');
    INSERT INTO t2 VALUES('e f a b c e');
    INSERT INTO t2 VALUES('e c a g c d');
    INSERT INTO t2 VALUES('g b d d e b');
    INSERT INTO t2 VALUES('e a d a e d');
  }
} -body {
  db eval COMMIT
} -test {
  faultsim_test_result {0 {}}
}

finish_test

do_catchsql_test 1.1 {
  SELECT fts5_rowid()
} {1 {should be: fts5_rowid(subject, ....)}}

do_catchsql_test 1.2 {
  SELECT fts5_rowid('segment')
} {1 {should be: fts5_rowid('segment', segid, height, pgno))}}

do_execsql_test 1.3 {
  SELECT fts5_rowid('segment', 1, 1, 1)
} {139586437121}

do_catchsql_test 1.4 {
  SELECT fts5_rowid('nosucharg');
} {1 {first arg to fts5_rowid() must be 'segment' or 'start-of-index'}} 


#-------------------------------------------------------------------------
# Tests of the fts5_decode() function.
#
reset_db
do_execsql_test 2.1 { 
................................................................................
} $res

# This is really a corruption test...
#do_execsql_test 2.7 {
#  UPDATE x1_data SET block = X'';
#  SELECT count(fts5_decode(rowid, block)) FROM x1_data;
#} $res





#-------------------------------------------------------------------------
# Tests with very large tokens.
#
set strlist [list \
  "[string repeat x 400]"                       \
  "[string repeat x 300][string repeat w 100]"  \

do_catchsql_test 1.1 {
  SELECT fts5_rowid()
} {1 {should be: fts5_rowid(subject, ....)}}

do_catchsql_test 1.2 {
  SELECT fts5_rowid('segment')
} {1 {should be: fts5_rowid('segment', segid, pgno))}}

do_execsql_test 1.3 {
  SELECT fts5_rowid('segment', 1, 1)
} {137438953473}

do_catchsql_test 1.4 {
  SELECT fts5_rowid('nosucharg');
} {1 {first arg to fts5_rowid() must be 'segment'}} 


#-------------------------------------------------------------------------
# Tests of the fts5_decode() function.
#
reset_db
do_execsql_test 2.1 { 
................................................................................
} $res

# This is really a corruption test...
#do_execsql_test 2.7 {
#  UPDATE x1_data SET block = X'';
#  SELECT count(fts5_decode(rowid, block)) FROM x1_data;
#} $res

do_execsql_test 2.8 {
  SELECT fts5_decode(fts5_rowid('segment', 1000, 1), X'AB')
} {corrupt}

#-------------------------------------------------------------------------
# Tests with very large tokens.
#
set strlist [list \
  "[string repeat x 400]"                       \
  "[string repeat x 300][string repeat w 100]"  \

# 2015 September 05
#
# 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.
#
#*************************************************************************
#

source [file join [file dirname [info script]] fts5_common.tcl]
set testprefix fts5simple

# If SQLITE_ENABLE_FTS5 is defined, omit this file.
ifcapable !fts5 {
  finish_test
  return
}

if 1 {
#-------------------------------------------------------------------------
#
set doc "x x [string repeat {y } 50]z z"
do_execsql_test 1.0 {
  CREATE VIRTUAL TABLE t1 USING fts5(x);
  INSERT INTO t1(t1, rank) VALUES('pgsz', 32);
  BEGIN;
    INSERT INTO t1 VALUES($doc);
  COMMIT;
}

do_execsql_test 1.1 {
  INSERT INTO t1(t1) VALUES('integrity-check');
}

#-------------------------------------------------------------------------
#
reset_db
do_execsql_test 2.0 {
  CREATE VIRTUAL TABLE t1 USING fts5(x);
  INSERT INTO t1(t1, rank) VALUES('pgsz', 32);
  INSERT INTO t1 VALUES('a b c');
  INSERT INTO t1 VALUES('d e f');
  INSERT INTO t1(t1) VALUES('optimize');
}

do_execsql_test 2.1 {
  INSERT INTO t1(t1) VALUES('integrity-check');
} {}


#-------------------------------------------------------------------------
#
reset_db
do_execsql_test 3.0 {
  CREATE VIRTUAL TABLE t1 USING fts5(x, prefix='1,2');
  INSERT INTO t1(t1, rank) VALUES('pgsz', 32);
  BEGIN;
  INSERT INTO t1 VALUES('one');
  SELECT * FROM t1 WHERE t1 MATCH 'o*';
} {one}

do_execsql_test 3.1 {
  INSERT INTO t1(t1) VALUES('integrity-check');
} {}

#-------------------------------------------------------------------------
reset_db
do_execsql_test 4.1 {
  CREATE VIRTUAL TABLE t11 USING fts5(content);
  INSERT INTO t11(t11, rank) VALUES('pgsz', 32);
  INSERT INTO t11 VALUES('another');
  INSERT INTO t11 VALUES('string');
  INSERT INTO t11 VALUES('of');
  INSERT INTO t11 VALUES('text');
}
do_test 4.2 {
  execsql { INSERT INTO t11(t11) VALUES('optimize') }
} {}
do_execsql_test 4.3 {
  INSERT INTO t11(t11) VALUES('integrity-check');
} {}

#db eval { SELECT fts5_decode(rowid, block) as x FROM t11_data } { puts $x }

#-------------------------------------------------------------------------
reset_db
set doc [string repeat "x y " 5]
do_execsql_test 5.1 {
  CREATE VIRTUAL TABLE yy USING fts5(content);
  INSERT INTO yy(yy, rank) VALUES('pgsz', 32);
  BEGIN;
    INSERT INTO yy VALUES($doc);
    INSERT INTO yy VALUES($doc);
    INSERT INTO yy VALUES($doc);
    INSERT INTO yy VALUES($doc);
    INSERT INTO yy VALUES($doc);
    INSERT INTO yy VALUES($doc);
    INSERT INTO yy VALUES($doc);
    INSERT INTO yy VALUES($doc);
  COMMIT;
}

do_execsql_test 5.2 {
  SELECT rowid FROM yy WHERE yy MATCH 'y' ORDER BY rowid ASC
} {1 2 3 4 5 6 7 8}

do_execsql_test 5.3 {
  SELECT rowid FROM yy WHERE yy MATCH 'y' ORDER BY rowid DESC
} {8 7 6 5 4 3 2 1}

#db eval { SELECT fts5_decode(rowid, block) as x FROM yy_data } { puts $x }

#-------------------------------------------------------------------------
reset_db
do_execsql_test 5.1 {
  CREATE VIRTUAL TABLE tt USING fts5(content);
  INSERT INTO tt(tt, rank) VALUES('pgsz', 32);
  INSERT INTO tt VALUES('aa');
}

do_execsql_test 5.2 {
  SELECT rowid FROM tt WHERE tt MATCH 'a*';
} {1}

do_execsql_test 5.3 {
  DELETE FROM tt;
  BEGIN;
    INSERT INTO tt VALUES('aa');
    INSERT INTO tt VALUES('ab');
  COMMIT;
} {}

do_execsql_test 5.4 {
  SELECT rowid FROM tt WHERE tt MATCH 'a*';
} {1 2}

}

do_execsql_test 5.5 {
  DELETE FROM tt;
  BEGIN;
    INSERT INTO tt VALUES('aa');
    INSERT INTO tt VALUES('ab');
    INSERT INTO tt VALUES('aa');
    INSERT INTO tt VALUES('ab');
    INSERT INTO tt VALUES('aa');
    INSERT INTO tt VALUES('ab');
    INSERT INTO tt VALUES('aa');
    INSERT INTO tt VALUES('ab');
  COMMIT;
  SELECT rowid FROM tt WHERE tt MATCH 'a*';
} {1 2 3 4 5 6 7 8}

do_execsql_test 5.6 {
  INSERT INTO tt(tt) VALUES('integrity-check');
}

reset_db
do_execsql_test 5.7 {
  CREATE VIRTUAL TABLE tt USING fts5(content);
  INSERT INTO tt(tt, rank) VALUES('pgsz', 32);
  INSERT INTO tt VALUES('aa ab ac ad ae af');
}

do_execsql_test 5.8 {
  SELECT rowid FROM tt WHERE tt MATCH 'a*';
} {1}

finish_test

do_execsql_test 1.1 {
  CREATE VIRTUAL TABLE t1 USING fts5(one);
  INSERT INTO t1 VALUES('a b c d');
} {}

do_execsql_test 1.2 {
  SELECT * FROM t1_config WHERE k='version'
} {version 3}

do_execsql_test 1.3 {
  SELECT rowid FROM t1 WHERE t1 MATCH 'a';
} {1}

do_execsql_test 1.4 {
  UPDATE t1_config set v=4 WHERE k='version';
} 

do_test 1.5 {
  db close
  sqlite3 db test.db
  catchsql { SELECT * FROM t1 WHERE t1 MATCH 'a' }
} {1 {invalid fts5 file format (found 4, expected 3) - run 'rebuild'}}

do_test 1.6 {
  db close
  sqlite3 db test.db
  catchsql { INSERT INTO t1 VALUES('x y z') }
} {1 {invalid fts5 file format (found 4, expected 3) - run 'rebuild'}}

do_test 1.7 {
  execsql { DELETE FROM t1_config WHERE k='version' }
  db close
  sqlite3 db test.db
  catchsql { SELECT * FROM t1 WHERE t1 MATCH 'a' }
} {1 {invalid fts5 file format (found 0, expected 3) - run 'rebuild'}}


finish_test

do_execsql_test 1.1 {
  CREATE VIRTUAL TABLE t1 USING fts5(one);
  INSERT INTO t1 VALUES('a b c d');
} {}

do_execsql_test 1.2 {
  SELECT * FROM t1_config WHERE k='version'
} {version 4}

do_execsql_test 1.3 {
  SELECT rowid FROM t1 WHERE t1 MATCH 'a';
} {1}

do_execsql_test 1.4 {
  UPDATE t1_config set v=5 WHERE k='version';
} 

do_test 1.5 {
  db close
  sqlite3 db test.db
  catchsql { SELECT * FROM t1 WHERE t1 MATCH 'a' }
} {1 {invalid fts5 file format (found 5, expected 4) - run 'rebuild'}}

do_test 1.6 {
  db close
  sqlite3 db test.db
  catchsql { INSERT INTO t1 VALUES('x y z') }
} {1 {invalid fts5 file format (found 5, expected 4) - run 'rebuild'}}

do_test 1.7 {
  execsql { DELETE FROM t1_config WHERE k='version' }
  db close
  sqlite3 db test.db
  catchsql { SELECT * FROM t1 WHERE t1 MATCH 'a' }
} {1 {invalid fts5 file format (found 0, expected 4) - run 'rebuild'}}


finish_test

  foreach f [glob -nocomplain -dir $dir *] {
    if {$::O(limit) && $::nRow>=$::O(limit)} break
    if {[file isdir $f]} {
      load_hierachy $f
    } else {
      db eval { INSERT INTO t1 VALUES($f, loadfile($f)) }
      incr ::nRow







      if {($::nRow % $::nRowPerDot)==0} {
        puts -nonewline .
        if {($::nRow % (65*$::nRowPerDot))==0} { puts "" }
        flush stdout
      }

................................................................................
  puts stderr "  -fts5        (use fts5)"
  puts stderr "  -porter      (use porter tokenizer)"
  puts stderr "  -delete      (delete the database file before starting)"
  puts stderr "  -limit N     (load no more than N documents)"
  puts stderr "  -automerge N (set the automerge parameter to N)"
  puts stderr "  -crisismerge N (set the crisismerge parameter to N)"
  puts stderr "  -prefix PREFIX (comma separated prefix= argument)"

  exit 1
}

set O(vtab)       fts5
set O(tok)        ""
set O(limit)      0
set O(delete)     0
set O(automerge)  -1
set O(crisismerge)  -1
set O(prefix)     ""


if {[llength $argv]<2} usage
set nOpt [expr {[llength $argv]-2}]
for {set i 0} {$i < $nOpt} {incr i} {
  set arg [lindex $argv $i]
  switch -- [lindex $argv $i] {
    -fts4 {
................................................................................
      set O(delete) 1
    }

    -limit {
      if { [incr i]>=$nOpt } usage
      set O(limit) [lindex $argv $i]
    }





    
    -automerge {
      if { [incr i]>=$nOpt } usage
      set O(automerge) [lindex $argv $i]
    }

    -crisismerge {
................................................................................
}

set dbfile [lindex $argv end-1]
if {$O(delete)} { file delete -force $dbfile }
sqlite3 db $dbfile
catch { load_static_extension db fts5 }
db func loadfile loadfile


db transaction {

  set pref ""
  if {$O(prefix)!=""} { set pref ", prefix='$O(prefix)'" }
  catch {
    db eval "CREATE VIRTUAL TABLE t1 USING $O(vtab) (path, content$O(tok)$pref)"
    db eval "INSERT INTO t1(t1, rank) VALUES('pgsz', 4050);"
  }
  if {$O(automerge)>=0} {
................................................................................
  if {$O(crisismerge)>=0} {
    if {$O(vtab) == "fts5"} {
      db eval {INSERT INTO t1(t1, rank) VALUES('crisismerge', $O(crisismerge))}
    } else {
    }
  }
  load_hierachy [lindex $argv end]
}

  foreach f [glob -nocomplain -dir $dir *] {
    if {$::O(limit) && $::nRow>=$::O(limit)} break
    if {[file isdir $f]} {
      load_hierachy $f
    } else {
      db eval { INSERT INTO t1 VALUES($f, loadfile($f)) }
      incr ::nRow

      if {$::O(trans) && ($::nRow % $::O(trans))==0} {
        db eval { COMMIT }
        db eval { INSERT INTO t1(t1) VALUES('integrity-check') }
        db eval { BEGIN }
      }

      if {($::nRow % $::nRowPerDot)==0} {
        puts -nonewline .
        if {($::nRow % (65*$::nRowPerDot))==0} { puts "" }
        flush stdout
      }

................................................................................
  puts stderr "  -fts5        (use fts5)"
  puts stderr "  -porter      (use porter tokenizer)"
  puts stderr "  -delete      (delete the database file before starting)"
  puts stderr "  -limit N     (load no more than N documents)"
  puts stderr "  -automerge N (set the automerge parameter to N)"
  puts stderr "  -crisismerge N (set the crisismerge parameter to N)"
  puts stderr "  -prefix PREFIX (comma separated prefix= argument)"
  puts stderr "  -trans N     (commit after N inserts - 0 == never)"
  exit 1
}

set O(vtab)       fts5
set O(tok)        ""
set O(limit)      0
set O(delete)     0
set O(automerge)  -1
set O(crisismerge)  -1
set O(prefix)     ""
set O(trans)      0

if {[llength $argv]<2} usage
set nOpt [expr {[llength $argv]-2}]
for {set i 0} {$i < $nOpt} {incr i} {
  set arg [lindex $argv $i]
  switch -- [lindex $argv $i] {
    -fts4 {
................................................................................
      set O(delete) 1
    }

    -limit {
      if { [incr i]>=$nOpt } usage
      set O(limit) [lindex $argv $i]
    }

    -trans {
      if { [incr i]>=$nOpt } usage
      set O(trans) [lindex $argv $i]
    }
    
    -automerge {
      if { [incr i]>=$nOpt } usage
      set O(automerge) [lindex $argv $i]
    }

    -crisismerge {
................................................................................
}

set dbfile [lindex $argv end-1]
if {$O(delete)} { file delete -force $dbfile }
sqlite3 db $dbfile
catch { load_static_extension db fts5 }
db func loadfile loadfile
db eval "PRAGMA page_size=4096"


db eval BEGIN
  set pref ""
  if {$O(prefix)!=""} { set pref ", prefix='$O(prefix)'" }
  catch {
    db eval "CREATE VIRTUAL TABLE t1 USING $O(vtab) (path, content$O(tok)$pref)"
    db eval "INSERT INTO t1(t1, rank) VALUES('pgsz', 4050);"
  }
  if {$O(automerge)>=0} {
................................................................................
  if {$O(crisismerge)>=0} {
    if {$O(vtab) == "fts5"} {
      db eval {INSERT INTO t1(t1, rank) VALUES('crisismerge', $O(crisismerge))}
    } else {
    }
  }
  load_hierachy [lindex $argv end]
db eval COMMIT

#define JSON_FALSE    2
#define JSON_INT      3
#define JSON_REAL     4
#define JSON_STRING   5
#define JSON_ARRAY    6
#define JSON_OBJECT   7




/*
** Names of the various JSON types:
*/
static const char * const jsonType[] = {
  "null", "true", "false", "integer", "real", "text", "array", "object"
};

................................................................................
/* Bit values for the JsonNode.jnFlag field
*/
#define JNODE_RAW     0x01         /* Content is raw, not JSON encoded */
#define JNODE_ESCAPE  0x02         /* Content is text with \ escapes */
#define JNODE_REMOVE  0x04         /* Do not output */
#define JNODE_REPLACE 0x08         /* Replace with JsonNode.iVal */
#define JNODE_APPEND  0x10         /* More ARRAY/OBJECT entries at u.iAppend */
#define JNODE_JSON    0x20         /* Treat REPLACE as JSON text */


/* A single node of parsed JSON
*/
struct JsonNode {
  u8 eType;              /* One of the JSON_ type values */
  u8 jnFlags;            /* JNODE flags */
................................................................................

/*
** Append a function parameter value to the JSON string under 
** construction.
*/
static void jsonAppendValue(
  JsonString *p,                 /* Append to this JSON string */
  sqlite3_value *pValue,         /* Value to append */
  u8 textIsJson                  /* Try to treat text values as JSON */
){
  switch( sqlite3_value_type(pValue) ){
    case SQLITE_NULL: {
      jsonAppendRaw(p, "null", 4);
      break;
    }
    case SQLITE_INTEGER:
................................................................................
      u32 n = (u32)sqlite3_value_bytes(pValue);
      jsonAppendRaw(p, z, n);
      break;
    }
    case SQLITE_TEXT: {
      const char *z = (const char*)sqlite3_value_text(pValue);
      u32 n = (u32)sqlite3_value_bytes(pValue);
      if( textIsJson ){
        jsonAppendRaw(p, z, n);
      }else{
        jsonAppendString(p, z, n);
      }
      break;
    }
    default: {
................................................................................
      u32 j = 1;
      jsonAppendChar(pOut, '[');
      for(;;){
        while( j<=pNode->n ){
          if( pNode[j].jnFlags & (JNODE_REMOVE|JNODE_REPLACE) ){
            if( pNode[j].jnFlags & JNODE_REPLACE ){
              jsonAppendSeparator(pOut);
              jsonAppendValue(pOut, aReplace[pNode[j].iVal],
                              (pNode[j].jnFlags & JNODE_JSON)!=0);
            }
          }else{
            jsonAppendSeparator(pOut);
            jsonRenderNode(&pNode[j], pOut, aReplace);
          }
          j += jsonNodeSize(&pNode[j]);
        }
................................................................................
      for(;;){
        while( j<=pNode->n ){
          if( (pNode[j+1].jnFlags & JNODE_REMOVE)==0 ){
            jsonAppendSeparator(pOut);
            jsonRenderNode(&pNode[j], pOut, aReplace);
            jsonAppendChar(pOut, ':');
            if( pNode[j+1].jnFlags & JNODE_REPLACE ){
              jsonAppendValue(pOut, aReplace[pNode[j+1].iVal],
                              (pNode[j+1].jnFlags & JNODE_JSON)!=0);
            }else{
              jsonRenderNode(&pNode[j+1], pOut, aReplace);
            }
          }
          j += 1 + jsonNodeSize(&pNode[j+1]);
        }
        if( (pNode->jnFlags & JNODE_APPEND)==0 ) break;
................................................................................
  sqlite3_context *pCtx,      /* Return value for this function */
  sqlite3_value **aReplace    /* Array of replacement values */
){
  JsonString s;
  jsonInit(&s, pCtx);
  jsonRenderNode(pNode, &s, aReplace);
  jsonResult(&s);

}

/*
** Make the JsonNode the return value of the function.
*/
static void jsonReturn(
  JsonNode *pNode,            /* Node to return */
................................................................................
                if( c>='0' && c<='9' ) v = v*16 + c - '0';
                else if( c>='A' && c<='F' ) v = v*16 + c - 'A' + 10;
                else if( c>='a' && c<='f' ) v = v*16 + c - 'a' + 10;
                else break;
              }
              if( v==0 ) break;
              if( v<=0x7f ){
                zOut[j++] = v;
              }else if( v<=0x7ff ){
                zOut[j++] = 0xc0 | (v>>6);
                zOut[j++] = 0x80 | (v&0x3f);
              }else{
                zOut[j++] = 0xe0 | (v>>12);
                zOut[j++] = 0x80 | ((v>>6)&0x3f);
                zOut[j++] = 0x80 | (v&0x3f);
              }
            }else{
              if( c=='b' ){
                c = '\b';
              }else if( c=='f' ){
................................................................................
** non-whitespace character is ']'.
*/
static int jsonParseValue(JsonParse *pParse, u32 i){
  char c;
  u32 j;
  int iThis;
  int x;

  while( isspace(pParse->zJson[i]) ){ i++; }
  if( (c = pParse->zJson[i])==0 ) return 0;
  if( c=='{' ){
    /* Parse object */
    iThis = jsonParseAddNode(pParse, JSON_OBJECT, 0, 0);
    if( iThis<0 ) return -1;
    for(j=i+1;;j++){
................................................................................
      while( isspace(pParse->zJson[j]) ){ j++; }
      x = jsonParseValue(pParse, j);
      if( x<0 ){
        if( x==(-2) && pParse->nNode==(u32)iThis+1 ) return j+1;
        return -1;
      }
      if( pParse->oom ) return -1;
      if( pParse->aNode[pParse->nNode-1].eType!=JSON_STRING ) return -1;


      j = x;
      while( isspace(pParse->zJson[j]) ){ j++; }
      if( pParse->zJson[j]!=':' ) return -1;
      j++;
      x = jsonParseValue(pParse, j);
      if( x<0 ) return -1;
      j = x;
................................................................................
** Return NULL if not found or if there is an error.
**
** On an error, write an error message into pCtx and increment the
** pParse->nErr counter.
**
** If pApnd!=NULL then try to append missing nodes and set *pApnd = 1 if
** nodes are appended.
**
** If the path starts with $$ then set *pFlags to JNODE_REPLACE|JNODE_JSON
** as a single to the caller that the input text to be inserted should be 
** interpreted as JSON rather than as ordinary text.
*/
static JsonNode *jsonLookup(
  JsonParse *pParse,      /* The JSON to search */
  const char *zPath,      /* The path to search */
  int *pApnd,             /* Append nodes to complete path if not NULL */
  sqlite3_context *pCtx,  /* Report errors here, if not NULL */
  u8 *pFlags              /* Write JNODE_REPLACE or _REPLACE|_JSON here */
){
  const char *zErr = 0;
  JsonNode *pNode = 0;
  u8 fg = JNODE_REPLACE;

  if( zPath==0 ) return 0;
  if( zPath[0]!='$' ){
    zErr = zPath;
    goto lookup_err;
  }
  zPath++;
  if( zPath[0]=='$' ){
    if( pFlags==0 ){
      zErr = zPath;
      goto lookup_err;
    }
    zPath++;
    fg = JNODE_REPLACE|JNODE_JSON;
  }
  if( pFlags ) *pFlags = fg;
  pNode = jsonLookupStep(pParse, 0, zPath, pApnd, &zErr);
  return pNode;

lookup_err:
  pParse->nErr++;
  if( zErr!=0 && pCtx!=0 ){
    char *z = jsonPathSyntaxError(zErr);
................................................................................
    if( z ){
      sqlite3_result_error(pCtx, z, -1);
      sqlite3_free(z);
    }else{
      sqlite3_result_error_nomem(pCtx);
    }
  }
  if( pFlags ) *pFlags = fg;
  return 0;
}


/*
** Report the wrong number of arguments for json_insert(), json_replace()
** or json_set().
................................................................................
  u32 i;

  assert( argc==1 );
  if( jsonParse(&x, ctx, (const char*)sqlite3_value_text(argv[0])) ) return;
  jsonParseFindParents(&x);
  jsonInit(&s, ctx);
  for(i=0; i<x.nNode; i++){







    jsonPrintf(100, &s,"node %3u: %7s n=%-4d up=%d\n",
               i, jsonType[x.aNode[i].eType], x.aNode[i].n, x.aUp[i]);
    if( x.aNode[i].u.zJContent!=0 ){
      jsonAppendRaw(&s, "    text: ", 10);
      jsonAppendRaw(&s, x.aNode[i].u.zJContent, x.aNode[i].n);
      jsonAppendRaw(&s, "\n", 1);
    }

  }
  jsonParseReset(&x);
  jsonResult(&s);
}

/*
** The json_test1(JSON) function parses and rebuilds the JSON string.


*/
static void jsonTest1Func(
  sqlite3_context *ctx,
  int argc,
  sqlite3_value **argv
){
  JsonParse x;  /* The parse */
  if( jsonParse(&x, ctx, (const char*)sqlite3_value_text(argv[0])) ) return;
  jsonReturnJson(x.aNode, ctx, 0);
  jsonParseReset(&x);
}

/*
** The json_nodecount(JSON) function returns the number of nodes in the
** input JSON string.
*/
static void jsonNodeCountFunc(
  sqlite3_context *ctx,
  int argc,
  sqlite3_value **argv
){
  JsonParse x;  /* The parse */
  if( jsonParse(&x, ctx, (const char*)sqlite3_value_text(argv[0])) ) return;
  sqlite3_result_int64(ctx, (sqlite3_int64)x.nNode);
  jsonParseReset(&x);
}
#endif /* SQLITE_DEBUG */

/****************************************************************************
** SQL function implementations
****************************************************************************/

................................................................................
  int i;
  JsonString jx;

  jsonInit(&jx, ctx);
  jsonAppendChar(&jx, '[');
  for(i=0; i<argc; i++){
    jsonAppendSeparator(&jx);
    jsonAppendValue(&jx, argv[i], 0);
  }
  jsonAppendChar(&jx, ']');
  jsonResult(&jx);

}


/*
** json_array_length(JSON)
** json_array_length(JSON, PATH)
**
................................................................................
  u32 i;

  if( jsonParse(&x, ctx, (const char*)sqlite3_value_text(argv[0])) ) return;
  if( x.nNode ){
    JsonNode *pNode;
    if( argc==2 ){
      const char *zPath = (const char*)sqlite3_value_text(argv[1]);
      pNode = jsonLookup(&x, zPath, 0, ctx, 0);
    }else{
      pNode = x.aNode;
    }
    if( pNode==0 ){
      x.nErr = 1;
    }else if( pNode->eType==JSON_ARRAY ){
      assert( (pNode->jnFlags & JNODE_APPEND)==0 );
................................................................................

  if( argc<2 ) return;
  if( jsonParse(&x, ctx, (const char*)sqlite3_value_text(argv[0])) ) return;
  jsonInit(&jx, ctx);
  jsonAppendChar(&jx, '[');
  for(i=1; i<argc; i++){
    zPath = (const char*)sqlite3_value_text(argv[i]);
    pNode = jsonLookup(&x, zPath, 0, ctx, 0);
    if( x.nErr ) break;
    if( argc>2 ){
      jsonAppendSeparator(&jx);
      if( pNode ){
        jsonRenderNode(pNode, &jx, 0);
      }else{
        jsonAppendRaw(&jx, "null", 4);
................................................................................
    }else if( pNode ){
      jsonReturn(pNode, ctx, 0);
    }
  }
  if( argc>2 && i==argc ){
    jsonAppendChar(&jx, ']');
    jsonResult(&jx);

  }
  jsonReset(&jx);
  jsonParseReset(&x);
}

/*
** Implementation of the json_object(NAME,VALUE,...) function.  Return a JSON
................................................................................
      return;
    }
    jsonAppendSeparator(&jx);
    z = (const char*)sqlite3_value_text(argv[i]);
    n = (u32)sqlite3_value_bytes(argv[i]);
    jsonAppendString(&jx, z, n);
    jsonAppendChar(&jx, ':');
    jsonAppendValue(&jx, argv[i+1], 0);
  }
  jsonAppendChar(&jx, '}');
  jsonResult(&jx);

}


/*
** json_remove(JSON, PATH, ...)
**
** Remove the named elements from JSON and return the result.  malformed
................................................................................

  if( argc<1 ) return;
  if( jsonParse(&x, ctx, (const char*)sqlite3_value_text(argv[0])) ) return;
  if( x.nNode ){
    for(i=1; i<(u32)argc; i++){
      zPath = (const char*)sqlite3_value_text(argv[i]);
      if( zPath==0 ) goto remove_done;
      pNode = jsonLookup(&x, zPath, 0, ctx, 0);
      if( x.nErr ) goto remove_done;
      if( pNode ) pNode->jnFlags |= JNODE_REMOVE;
    }
    if( (x.aNode[0].jnFlags & JNODE_REMOVE)==0 ){
      jsonReturnJson(x.aNode, ctx, 0);
    }
  }
................................................................................
  if( (argc&1)==0 ) {
    jsonWrongNumArgs(ctx, "replace");
    return;
  }
  if( jsonParse(&x, ctx, (const char*)sqlite3_value_text(argv[0])) ) return;
  if( x.nNode ){
    for(i=1; i<(u32)argc; i+=2){
      u8 jnFlags = JNODE_REPLACE;
      zPath = (const char*)sqlite3_value_text(argv[i]);
      pNode = jsonLookup(&x, zPath, 0, ctx, &jnFlags);
      if( x.nErr ) goto replace_err;
      if( pNode ){
        pNode->jnFlags &= ~JNODE_JSON;
        pNode->jnFlags |= jnFlags;
        pNode->iVal = i+1;
      }
    }
    if( x.aNode[0].jnFlags & JNODE_REPLACE ){
      sqlite3_result_value(ctx, argv[x.aNode[0].iVal]);
    }else{
      jsonReturnJson(x.aNode, ctx, argv);
    }
................................................................................
  if( (argc&1)==0 ) {
    jsonWrongNumArgs(ctx, bIsSet ? "set" : "insert");
    return;
  }
  if( jsonParse(&x, ctx, (const char*)sqlite3_value_text(argv[0])) ) return;
  if( x.nNode ){
    for(i=1; i<(u32)argc; i+=2){
      u8 jnFlags = JNODE_REPLACE;
      zPath = (const char*)sqlite3_value_text(argv[i]);
      bApnd = 0;
      pNode = jsonLookup(&x, zPath, &bApnd, ctx, &jnFlags);
      if( x.oom ){
        sqlite3_result_error_nomem(ctx);
        goto jsonSetDone;
      }else if( x.nErr ){
        goto jsonSetDone;
      }else if( pNode && (bApnd || bIsSet) ){
        pNode->jnFlags &= ~JNODE_JSON;
        pNode->jnFlags |= jnFlags;
        pNode->iVal = i+1;
      }
    }
    if( x.aNode[0].jnFlags & JNODE_REPLACE ){
      sqlite3_result_value(ctx, argv[x.aNode[0].iVal]);
    }else{
      jsonReturnJson(x.aNode, ctx, argv);
    }
................................................................................
  const char *zPath;

  if( jsonParse(&x, ctx, (const char*)sqlite3_value_text(argv[0])) ) return;
  if( x.nNode ){
    JsonNode *pNode;
    if( argc==2 ){
      zPath = (const char*)sqlite3_value_text(argv[1]);
      pNode = jsonLookup(&x, zPath, 0, ctx, 0);
    }else{
      pNode = x.aNode;
    }
    if( pNode ){
      sqlite3_result_text(ctx, jsonType[pNode->eType], -1, SQLITE_STATIC);
    }
  }
................................................................................
  sqlite3_context *ctx,
  int argc,
  sqlite3_value **argv
){
  JsonParse x;          /* The parse */
  int rc = 0;


  if( jsonParse(&x, 0, (const char*)sqlite3_value_text(argv[0]))==0 
   && x.nNode>0
  ){
    rc = 1;
  }
  jsonParseReset(&x);
  sqlite3_result_int(ctx, rc);
................................................................................
/****************************************************************************
** The json_each virtual table
****************************************************************************/
typedef struct JsonEachCursor JsonEachCursor;
struct JsonEachCursor {
  sqlite3_vtab_cursor base;  /* Base class - must be first */
  u32 iRowid;                /* The rowid */

  u32 i;                     /* Index in sParse.aNode[] of current row */
  u32 iEnd;                  /* EOF when i equals or exceeds this value */
  u8 eType;                  /* Type of top-level element */
  u8 bRecursive;             /* True for json_tree().  False for json_each() */
  char *zJson;               /* Input JSON */
  char *zPath;               /* Path by which to filter zJson */
  JsonParse sParse;          /* Parse of the input JSON */
};

/* Constructor for the json_each virtual table */
static int jsonEachConnect(
  sqlite3 *db,
  void *pAux,
................................................................................
#define JEACH_KEY     0
#define JEACH_VALUE   1
#define JEACH_TYPE    2
#define JEACH_ATOM    3
#define JEACH_ID      4
#define JEACH_PARENT  5
#define JEACH_FULLKEY 6

#define JEACH_JSON    7
#define JEACH_PATH    8

  UNUSED_PARAM(pzErr);
  UNUSED_PARAM(argv);
  UNUSED_PARAM(argc);
  UNUSED_PARAM(pAux);
  rc = sqlite3_declare_vtab(db, 
     "CREATE TABLE x(key,value,type,atom,id,parent,fullkey,"
                    "json HIDDEN,path HIDDEN)");
  if( rc==SQLITE_OK ){
    pNew = *ppVtab = sqlite3_malloc( sizeof(*pNew) );
    if( pNew==0 ) return SQLITE_NOMEM;
    memset(pNew, 0, sizeof(*pNew));
  }
  return rc;
}
................................................................................
  return rc;
}

/* Reset a JsonEachCursor back to its original state.  Free any memory
** held. */
static void jsonEachCursorReset(JsonEachCursor *p){
  sqlite3_free(p->zJson);
  sqlite3_free(p->zPath);
  jsonParseReset(&p->sParse);
  p->iRowid = 0;
  p->i = 0;
  p->iEnd = 0;
  p->eType = 0;
  p->zJson = 0;
  p->zPath = 0;
}

/* Destructor for a jsonEachCursor object */
static int jsonEachClose(sqlite3_vtab_cursor *cur){
  JsonEachCursor *p = (JsonEachCursor*)cur;
  jsonEachCursorReset(p);
  sqlite3_free(cur);
................................................................................
  return p->i >= p->iEnd;
}

/* Advance the cursor to the next element for json_tree() */
static int jsonEachNext(sqlite3_vtab_cursor *cur){
  JsonEachCursor *p = (JsonEachCursor*)cur;
  if( p->bRecursive ){
    if( p->i==0 ){
      p->i = 1;
    }else{
      u32 iUp = p->sParse.aUp[p->i];
      JsonNode *pUp = &p->sParse.aNode[iUp];
      p->i++;
      if( pUp->eType==JSON_OBJECT && (pUp->n + iUp >= p->i) ) p->i++;
    }
    p->iRowid++;
    if( p->i<p->sParse.nNode ){
      u32 iUp = p->sParse.aUp[p->i];
      JsonNode *pUp = &p->sParse.aNode[iUp];
      p->eType = pUp->eType;
      if( pUp->eType==JSON_ARRAY ){
        if( iUp==p->i-1 ){
          pUp->u.iKey = 0;
        }else{
................................................................................
  jsonEachComputePath(p, pStr, iUp);
  pNode = &p->sParse.aNode[i];
  pUp = &p->sParse.aNode[iUp];
  if( pUp->eType==JSON_ARRAY ){
    jsonPrintf(30, pStr, "[%d]", pUp->u.iKey);
  }else{
    assert( pUp->eType==JSON_OBJECT );
    if( pNode->eType>=JSON_ARRAY ) pNode--;
    assert( pNode->eType==JSON_STRING );

    jsonPrintf(pNode->n+1, pStr, ".%.*s", pNode->n-2, pNode->u.zJContent+1);
  }
}

/* Return the value of a column */
static int jsonEachColumn(
  sqlite3_vtab_cursor *cur,   /* The cursor */
................................................................................
          iKey = p->iRowid;
        }
        sqlite3_result_int64(ctx, (sqlite3_int64)iKey);
      }
      break;
    }
    case JEACH_VALUE: {
      if( p->eType==JSON_OBJECT && p->i>0 ) pThis++;
      jsonReturn(pThis, ctx, 0);
      break;
    }
    case JEACH_TYPE: {
      if( p->eType==JSON_OBJECT && p->i>0 ) pThis++;
      sqlite3_result_text(ctx, jsonType[pThis->eType], -1, SQLITE_STATIC);
      break;
    }
    case JEACH_ATOM: {
      if( p->eType==JSON_OBJECT && p->i>0 ) pThis++;
      if( pThis->eType>=JSON_ARRAY ) break;
      jsonReturn(pThis, ctx, 0);
      break;
    }
    case JEACH_ID: {
      sqlite3_result_int64(ctx, (sqlite3_int64)p->i + (p->eType==JSON_OBJECT));

      break;
    }
    case JEACH_PARENT: {
      if( p->i>0 && p->bRecursive ){
        sqlite3_result_int64(ctx, (sqlite3_int64)p->sParse.aUp[p->i]);
      }
      break;
    }
    case JEACH_FULLKEY: {
      JsonString x;
      jsonInit(&x, ctx);
      if( p->bRecursive ){
        jsonEachComputePath(p, &x, p->i);
      }else{
        if( p->zPath ){
          jsonAppendRaw(&x, p->zPath, (int)strlen(p->zPath));
        }else{
          jsonAppendChar(&x, '$');
        }
        if( p->eType==JSON_ARRAY ){
          jsonPrintf(30, &x, "[%d]", p->iRowid);
        }else{
          jsonPrintf(pThis->n, &x, ".%.*s", pThis->n-2, pThis->u.zJContent+1);
        }
      }
      jsonResult(&x);
      break;
    }
    case JEACH_PATH: {
      const char *zPath = p->zPath;
       if( zPath==0 ){
        if( p->bRecursive ){
          JsonString x;
          jsonInit(&x, ctx);
          jsonEachComputePath(p, &x, p->sParse.aUp[p->i]);
          jsonResult(&x);
          break;
        }
        zPath = "$";


      }



      sqlite3_result_text(ctx, zPath, -1, SQLITE_STATIC);
      break;
    }
    default: {
      assert( i==JEACH_JSON );
      sqlite3_result_text(ctx, p->sParse.zJson, -1, SQLITE_STATIC);
      break;
    }
................................................................................
  JsonEachCursor *p = (JsonEachCursor*)cur;
  *pRowid = p->iRowid;
  return SQLITE_OK;
}

/* The query strategy is to look for an equality constraint on the json
** column.  Without such a constraint, the table cannot operate.  idxNum is
** 1 if the constraint is found, 3 if the constraint and zPath are found,
** and 0 otherwise.
*/
static int jsonEachBestIndex(
  sqlite3_vtab *tab,
  sqlite3_index_info *pIdxInfo
){
  int i;
  int jsonIdx = -1;
  int pathIdx = -1;
  const struct sqlite3_index_constraint *pConstraint;

  UNUSED_PARAM(tab);
  pConstraint = pIdxInfo->aConstraint;
  for(i=0; i<pIdxInfo->nConstraint; i++, pConstraint++){
    if( pConstraint->usable==0 ) continue;
    if( pConstraint->op!=SQLITE_INDEX_CONSTRAINT_EQ ) continue;
    switch( pConstraint->iColumn ){
      case JEACH_JSON:   jsonIdx = i;    break;
      case JEACH_PATH:   pathIdx = i;    break;
      default:           /* no-op */     break;
    }
  }
  if( jsonIdx<0 ){
    pIdxInfo->idxNum = 0;
    pIdxInfo->estimatedCost = 1e99;
  }else{
    pIdxInfo->estimatedCost = 1.0;
    pIdxInfo->aConstraintUsage[jsonIdx].argvIndex = 1;
    pIdxInfo->aConstraintUsage[jsonIdx].omit = 1;
    if( pathIdx<0 ){
      pIdxInfo->idxNum = 1;
    }else{
      pIdxInfo->aConstraintUsage[pathIdx].argvIndex = 2;
      pIdxInfo->aConstraintUsage[pathIdx].omit = 1;
      pIdxInfo->idxNum = 3;
    }
  }
  return SQLITE_OK;
}

/* Start a search on a new JSON string */
................................................................................
static int jsonEachFilter(
  sqlite3_vtab_cursor *cur,
  int idxNum, const char *idxStr,
  int argc, sqlite3_value **argv
){
  JsonEachCursor *p = (JsonEachCursor*)cur;
  const char *z;
  const char *zPath;
  sqlite3_int64 n;

  UNUSED_PARAM(idxStr);
  UNUSED_PARAM(argc);
  jsonEachCursorReset(p);
  if( idxNum==0 ) return SQLITE_OK;
  z = (const char*)sqlite3_value_text(argv[0]);
  if( z==0 ) return SQLITE_OK;
  if( idxNum&2 ){
    zPath = (const char*)sqlite3_value_text(argv[1]);
    if( zPath==0 ) return SQLITE_OK;
    if( zPath[0]!='$' ){
      sqlite3_free(cur->pVtab->zErrMsg);
      cur->pVtab->zErrMsg = jsonPathSyntaxError(zPath);
      return cur->pVtab->zErrMsg ? SQLITE_ERROR : SQLITE_NOMEM;
    }
  }
  n = sqlite3_value_bytes(argv[0]);
  p->zJson = sqlite3_malloc64( n+1 );
  if( p->zJson==0 ) return SQLITE_NOMEM;
  memcpy(p->zJson, z, (size_t)n+1);
................................................................................
  }else if( p->bRecursive && jsonParseFindParents(&p->sParse) ){
    jsonEachCursorReset(p);
    return SQLITE_NOMEM;
  }else{
    JsonNode *pNode;
    if( idxNum==3 ){
      const char *zErr = 0;
      p->bRecursive = 0;
      n = sqlite3_value_bytes(argv[1]);
      p->zPath = sqlite3_malloc64( n+1 );
      if( p->zPath==0 ) return SQLITE_NOMEM;
      memcpy(p->zPath, zPath, (size_t)n+1);

      pNode = jsonLookupStep(&p->sParse, 0, p->zPath+1, 0, &zErr);
      if( p->sParse.nErr ){
        sqlite3_free(cur->pVtab->zErrMsg);
        cur->pVtab->zErrMsg = jsonPathSyntaxError(zErr);
        jsonEachCursorReset(p);
        return cur->pVtab->zErrMsg ? SQLITE_ERROR : SQLITE_NOMEM;
      }else if( pNode==0 ){
        return SQLITE_OK;
      }
    }else{
      pNode = p->sParse.aNode;
    }
    p->i = (int)(pNode - p->sParse.aNode);
    p->eType = pNode->eType;
    if( p->eType>=JSON_ARRAY ){
      pNode->u.iKey = 0;
      p->iEnd = p->i + pNode->n + 1;
      if( !p->bRecursive ) p->i++;






    }else{
      p->iEnd = p->i+1;
    }
  }
  return p->sParse.oom ? SQLITE_NOMEM : SQLITE_OK;
}

................................................................................
  unsigned int i;
  static const struct {
     const char *zName;
     int nArg;
     int flag;
     void (*xFunc)(sqlite3_context*,int,sqlite3_value**);
  } aFunc[] = {

    { "json_array",          -1, 0,   jsonArrayFunc         },
    { "json_array_length",    1, 0,   jsonArrayLengthFunc   },
    { "json_array_length",    2, 0,   jsonArrayLengthFunc   },
    { "json_extract",        -1, 0,   jsonExtractFunc       },
    { "json_insert",         -1, 0,   jsonSetFunc           },
    { "json_object",         -1, 0,   jsonObjectFunc        },
    { "json_remove",         -1, 0,   jsonRemoveFunc        },
................................................................................
    { "json_type",            2, 0,   jsonTypeFunc          },
    { "json_valid",           1, 0,   jsonValidFunc         },

#if SQLITE_DEBUG
    /* DEBUG and TESTING functions */
    { "json_parse",           1, 0,   jsonParseFunc         },
    { "json_test1",           1, 0,   jsonTest1Func         },
    { "json_nodecount",       1, 0,   jsonNodeCountFunc     },
#endif
  };
#ifndef SQLITE_OMIT_VIRTUALTABLE
  static const struct {
     const char *zName;
     sqlite3_module *pModule;
  } aMod[] = {

#define JSON_FALSE    2
#define JSON_INT      3
#define JSON_REAL     4
#define JSON_STRING   5
#define JSON_ARRAY    6
#define JSON_OBJECT   7

/* The "subtype" set for JSON values */
#define JSON_SUBTYPE  74    /* Ascii for "J" */

/*
** Names of the various JSON types:
*/
static const char * const jsonType[] = {
  "null", "true", "false", "integer", "real", "text", "array", "object"
};

................................................................................
/* Bit values for the JsonNode.jnFlag field
*/
#define JNODE_RAW     0x01         /* Content is raw, not JSON encoded */
#define JNODE_ESCAPE  0x02         /* Content is text with \ escapes */
#define JNODE_REMOVE  0x04         /* Do not output */
#define JNODE_REPLACE 0x08         /* Replace with JsonNode.iVal */
#define JNODE_APPEND  0x10         /* More ARRAY/OBJECT entries at u.iAppend */
#define JNODE_LABEL   0x20         /* Is a label of an object */


/* A single node of parsed JSON
*/
struct JsonNode {
  u8 eType;              /* One of the JSON_ type values */
  u8 jnFlags;            /* JNODE flags */
................................................................................

/*
** Append a function parameter value to the JSON string under 
** construction.
*/
static void jsonAppendValue(
  JsonString *p,                 /* Append to this JSON string */
  sqlite3_value *pValue          /* Value to append */

){
  switch( sqlite3_value_type(pValue) ){
    case SQLITE_NULL: {
      jsonAppendRaw(p, "null", 4);
      break;
    }
    case SQLITE_INTEGER:
................................................................................
      u32 n = (u32)sqlite3_value_bytes(pValue);
      jsonAppendRaw(p, z, n);
      break;
    }
    case SQLITE_TEXT: {
      const char *z = (const char*)sqlite3_value_text(pValue);
      u32 n = (u32)sqlite3_value_bytes(pValue);
      if( sqlite3_value_subtype(pValue)==JSON_SUBTYPE ){
        jsonAppendRaw(p, z, n);
      }else{
        jsonAppendString(p, z, n);
      }
      break;
    }
    default: {
................................................................................
      u32 j = 1;
      jsonAppendChar(pOut, '[');
      for(;;){
        while( j<=pNode->n ){
          if( pNode[j].jnFlags & (JNODE_REMOVE|JNODE_REPLACE) ){
            if( pNode[j].jnFlags & JNODE_REPLACE ){
              jsonAppendSeparator(pOut);
              jsonAppendValue(pOut, aReplace[pNode[j].iVal]);

            }
          }else{
            jsonAppendSeparator(pOut);
            jsonRenderNode(&pNode[j], pOut, aReplace);
          }
          j += jsonNodeSize(&pNode[j]);
        }
................................................................................
      for(;;){
        while( j<=pNode->n ){
          if( (pNode[j+1].jnFlags & JNODE_REMOVE)==0 ){
            jsonAppendSeparator(pOut);
            jsonRenderNode(&pNode[j], pOut, aReplace);
            jsonAppendChar(pOut, ':');
            if( pNode[j+1].jnFlags & JNODE_REPLACE ){
              jsonAppendValue(pOut, aReplace[pNode[j+1].iVal]);

            }else{
              jsonRenderNode(&pNode[j+1], pOut, aReplace);
            }
          }
          j += 1 + jsonNodeSize(&pNode[j+1]);
        }
        if( (pNode->jnFlags & JNODE_APPEND)==0 ) break;
................................................................................
  sqlite3_context *pCtx,      /* Return value for this function */
  sqlite3_value **aReplace    /* Array of replacement values */
){
  JsonString s;
  jsonInit(&s, pCtx);
  jsonRenderNode(pNode, &s, aReplace);
  jsonResult(&s);
  sqlite3_result_subtype(pCtx, JSON_SUBTYPE);
}

/*
** Make the JsonNode the return value of the function.
*/
static void jsonReturn(
  JsonNode *pNode,            /* Node to return */
................................................................................
                if( c>='0' && c<='9' ) v = v*16 + c - '0';
                else if( c>='A' && c<='F' ) v = v*16 + c - 'A' + 10;
                else if( c>='a' && c<='f' ) v = v*16 + c - 'a' + 10;
                else break;
              }
              if( v==0 ) break;
              if( v<=0x7f ){
                zOut[j++] = (char)v;
              }else if( v<=0x7ff ){
                zOut[j++] = (char)(0xc0 | (v>>6));
                zOut[j++] = 0x80 | (v&0x3f);
              }else{
                zOut[j++] = (char)(0xe0 | (v>>12));
                zOut[j++] = 0x80 | ((v>>6)&0x3f);
                zOut[j++] = 0x80 | (v&0x3f);
              }
            }else{
              if( c=='b' ){
                c = '\b';
              }else if( c=='f' ){
................................................................................
** non-whitespace character is ']'.
*/
static int jsonParseValue(JsonParse *pParse, u32 i){
  char c;
  u32 j;
  int iThis;
  int x;
  JsonNode *pNode;
  while( isspace(pParse->zJson[i]) ){ i++; }
  if( (c = pParse->zJson[i])==0 ) return 0;
  if( c=='{' ){
    /* Parse object */
    iThis = jsonParseAddNode(pParse, JSON_OBJECT, 0, 0);
    if( iThis<0 ) return -1;
    for(j=i+1;;j++){
................................................................................
      while( isspace(pParse->zJson[j]) ){ j++; }
      x = jsonParseValue(pParse, j);
      if( x<0 ){
        if( x==(-2) && pParse->nNode==(u32)iThis+1 ) return j+1;
        return -1;
      }
      if( pParse->oom ) return -1;
      pNode = &pParse->aNode[pParse->nNode-1];
      if( pNode->eType!=JSON_STRING ) return -1;
      pNode->jnFlags |= JNODE_LABEL;
      j = x;
      while( isspace(pParse->zJson[j]) ){ j++; }
      if( pParse->zJson[j]!=':' ) return -1;
      j++;
      x = jsonParseValue(pParse, j);
      if( x<0 ) return -1;
      j = x;
................................................................................
** Return NULL if not found or if there is an error.
**
** On an error, write an error message into pCtx and increment the
** pParse->nErr counter.
**
** If pApnd!=NULL then try to append missing nodes and set *pApnd = 1 if
** nodes are appended.




*/
static JsonNode *jsonLookup(
  JsonParse *pParse,      /* The JSON to search */
  const char *zPath,      /* The path to search */
  int *pApnd,             /* Append nodes to complete path if not NULL */
  sqlite3_context *pCtx   /* Report errors here, if not NULL */

){
  const char *zErr = 0;
  JsonNode *pNode = 0;


  if( zPath==0 ) return 0;
  if( zPath[0]!='$' ){
    zErr = zPath;
    goto lookup_err;
  }
  zPath++;









  pNode = jsonLookupStep(pParse, 0, zPath, pApnd, &zErr);
  return pNode;

lookup_err:
  pParse->nErr++;
  if( zErr!=0 && pCtx!=0 ){
    char *z = jsonPathSyntaxError(zErr);
................................................................................
    if( z ){
      sqlite3_result_error(pCtx, z, -1);
      sqlite3_free(z);
    }else{
      sqlite3_result_error_nomem(pCtx);
    }
  }

  return 0;
}


/*
** Report the wrong number of arguments for json_insert(), json_replace()
** or json_set().
................................................................................
  u32 i;

  assert( argc==1 );
  if( jsonParse(&x, ctx, (const char*)sqlite3_value_text(argv[0])) ) return;
  jsonParseFindParents(&x);
  jsonInit(&s, ctx);
  for(i=0; i<x.nNode; i++){
    const char *zType;
    if( x.aNode[i].jnFlags & JNODE_LABEL ){
      assert( x.aNode[i].eType==JSON_STRING );
      zType = "label";
    }else{
      zType = jsonType[x.aNode[i].eType];
    }
    jsonPrintf(100, &s,"node %3u: %7s n=%-4d up=%-4d",
               i, zType, x.aNode[i].n, x.aUp[i]);
    if( x.aNode[i].u.zJContent!=0 ){
      jsonAppendRaw(&s, " ", 1);
      jsonAppendRaw(&s, x.aNode[i].u.zJContent, x.aNode[i].n);

    }
    jsonAppendRaw(&s, "\n", 1);
  }
  jsonParseReset(&x);
  jsonResult(&s);
}

/*
** The json_test1(JSON) function return true (1) if the input is JSON
** text generated by another json function.  It returns (0) if the input
** is not known to be JSON.
*/
static void jsonTest1Func(
  sqlite3_context *ctx,
  int argc,
  sqlite3_value **argv
){
  UNUSED_PARAM(argc);
  sqlite3_result_int(ctx, sqlite3_value_subtype(argv[0])==JSON_SUBTYPE);

















}
#endif /* SQLITE_DEBUG */

/****************************************************************************
** SQL function implementations
****************************************************************************/

................................................................................
  int i;
  JsonString jx;

  jsonInit(&jx, ctx);
  jsonAppendChar(&jx, '[');
  for(i=0; i<argc; i++){
    jsonAppendSeparator(&jx);
    jsonAppendValue(&jx, argv[i]);
  }
  jsonAppendChar(&jx, ']');
  jsonResult(&jx);
  sqlite3_result_subtype(ctx, JSON_SUBTYPE);
}


/*
** json_array_length(JSON)
** json_array_length(JSON, PATH)
**
................................................................................
  u32 i;

  if( jsonParse(&x, ctx, (const char*)sqlite3_value_text(argv[0])) ) return;
  if( x.nNode ){
    JsonNode *pNode;
    if( argc==2 ){
      const char *zPath = (const char*)sqlite3_value_text(argv[1]);
      pNode = jsonLookup(&x, zPath, 0, ctx);
    }else{
      pNode = x.aNode;
    }
    if( pNode==0 ){
      x.nErr = 1;
    }else if( pNode->eType==JSON_ARRAY ){
      assert( (pNode->jnFlags & JNODE_APPEND)==0 );
................................................................................

  if( argc<2 ) return;
  if( jsonParse(&x, ctx, (const char*)sqlite3_value_text(argv[0])) ) return;
  jsonInit(&jx, ctx);
  jsonAppendChar(&jx, '[');
  for(i=1; i<argc; i++){
    zPath = (const char*)sqlite3_value_text(argv[i]);
    pNode = jsonLookup(&x, zPath, 0, ctx);
    if( x.nErr ) break;
    if( argc>2 ){
      jsonAppendSeparator(&jx);
      if( pNode ){
        jsonRenderNode(pNode, &jx, 0);
      }else{
        jsonAppendRaw(&jx, "null", 4);
................................................................................
    }else if( pNode ){
      jsonReturn(pNode, ctx, 0);
    }
  }
  if( argc>2 && i==argc ){
    jsonAppendChar(&jx, ']');
    jsonResult(&jx);
    sqlite3_result_subtype(ctx, JSON_SUBTYPE);
  }
  jsonReset(&jx);
  jsonParseReset(&x);
}

/*
** Implementation of the json_object(NAME,VALUE,...) function.  Return a JSON
................................................................................
      return;
    }
    jsonAppendSeparator(&jx);
    z = (const char*)sqlite3_value_text(argv[i]);
    n = (u32)sqlite3_value_bytes(argv[i]);
    jsonAppendString(&jx, z, n);
    jsonAppendChar(&jx, ':');
    jsonAppendValue(&jx, argv[i+1]);
  }
  jsonAppendChar(&jx, '}');
  jsonResult(&jx);
  sqlite3_result_subtype(ctx, JSON_SUBTYPE);
}


/*
** json_remove(JSON, PATH, ...)
**
** Remove the named elements from JSON and return the result.  malformed
................................................................................

  if( argc<1 ) return;
  if( jsonParse(&x, ctx, (const char*)sqlite3_value_text(argv[0])) ) return;
  if( x.nNode ){
    for(i=1; i<(u32)argc; i++){
      zPath = (const char*)sqlite3_value_text(argv[i]);
      if( zPath==0 ) goto remove_done;
      pNode = jsonLookup(&x, zPath, 0, ctx);
      if( x.nErr ) goto remove_done;
      if( pNode ) pNode->jnFlags |= JNODE_REMOVE;
    }
    if( (x.aNode[0].jnFlags & JNODE_REMOVE)==0 ){
      jsonReturnJson(x.aNode, ctx, 0);
    }
  }
................................................................................
  if( (argc&1)==0 ) {
    jsonWrongNumArgs(ctx, "replace");
    return;
  }
  if( jsonParse(&x, ctx, (const char*)sqlite3_value_text(argv[0])) ) return;
  if( x.nNode ){
    for(i=1; i<(u32)argc; i+=2){

      zPath = (const char*)sqlite3_value_text(argv[i]);
      pNode = jsonLookup(&x, zPath, 0, ctx);
      if( x.nErr ) goto replace_err;
      if( pNode ){

        pNode->jnFlags |= (u8)JNODE_REPLACE;
        pNode->iVal = (u8)(i+1);
      }
    }
    if( x.aNode[0].jnFlags & JNODE_REPLACE ){
      sqlite3_result_value(ctx, argv[x.aNode[0].iVal]);
    }else{
      jsonReturnJson(x.aNode, ctx, argv);
    }
................................................................................
  if( (argc&1)==0 ) {
    jsonWrongNumArgs(ctx, bIsSet ? "set" : "insert");
    return;
  }
  if( jsonParse(&x, ctx, (const char*)sqlite3_value_text(argv[0])) ) return;
  if( x.nNode ){
    for(i=1; i<(u32)argc; i+=2){

      zPath = (const char*)sqlite3_value_text(argv[i]);
      bApnd = 0;
      pNode = jsonLookup(&x, zPath, &bApnd, ctx);
      if( x.oom ){
        sqlite3_result_error_nomem(ctx);
        goto jsonSetDone;
      }else if( x.nErr ){
        goto jsonSetDone;
      }else if( pNode && (bApnd || bIsSet) ){

        pNode->jnFlags |= (u8)JNODE_REPLACE;
        pNode->iVal = (u8)(i+1);
      }
    }
    if( x.aNode[0].jnFlags & JNODE_REPLACE ){
      sqlite3_result_value(ctx, argv[x.aNode[0].iVal]);
    }else{
      jsonReturnJson(x.aNode, ctx, argv);
    }
................................................................................
  const char *zPath;

  if( jsonParse(&x, ctx, (const char*)sqlite3_value_text(argv[0])) ) return;
  if( x.nNode ){
    JsonNode *pNode;
    if( argc==2 ){
      zPath = (const char*)sqlite3_value_text(argv[1]);
      pNode = jsonLookup(&x, zPath, 0, ctx);
    }else{
      pNode = x.aNode;
    }
    if( pNode ){
      sqlite3_result_text(ctx, jsonType[pNode->eType], -1, SQLITE_STATIC);
    }
  }
................................................................................
  sqlite3_context *ctx,
  int argc,
  sqlite3_value **argv
){
  JsonParse x;          /* The parse */
  int rc = 0;

  UNUSED_PARAM(argc);
  if( jsonParse(&x, 0, (const char*)sqlite3_value_text(argv[0]))==0 
   && x.nNode>0
  ){
    rc = 1;
  }
  jsonParseReset(&x);
  sqlite3_result_int(ctx, rc);
................................................................................
/****************************************************************************
** The json_each virtual table
****************************************************************************/
typedef struct JsonEachCursor JsonEachCursor;
struct JsonEachCursor {
  sqlite3_vtab_cursor base;  /* Base class - must be first */
  u32 iRowid;                /* The rowid */
  u32 iBegin;                /* The first node of the scan */
  u32 i;                     /* Index in sParse.aNode[] of current row */
  u32 iEnd;                  /* EOF when i equals or exceeds this value */
  u8 eType;                  /* Type of top-level element */
  u8 bRecursive;             /* True for json_tree().  False for json_each() */
  char *zJson;               /* Input JSON */
  char *zRoot;               /* Path by which to filter zJson */
  JsonParse sParse;          /* Parse of the input JSON */
};

/* Constructor for the json_each virtual table */
static int jsonEachConnect(
  sqlite3 *db,
  void *pAux,
................................................................................
#define JEACH_KEY     0
#define JEACH_VALUE   1
#define JEACH_TYPE    2
#define JEACH_ATOM    3
#define JEACH_ID      4
#define JEACH_PARENT  5
#define JEACH_FULLKEY 6
#define JEACH_PATH    7
#define JEACH_JSON    8
#define JEACH_ROOT    9

  UNUSED_PARAM(pzErr);
  UNUSED_PARAM(argv);
  UNUSED_PARAM(argc);
  UNUSED_PARAM(pAux);
  rc = sqlite3_declare_vtab(db, 
     "CREATE TABLE x(key,value,type,atom,id,parent,fullkey,path,"
                    "json HIDDEN,root HIDDEN)");
  if( rc==SQLITE_OK ){
    pNew = *ppVtab = sqlite3_malloc( sizeof(*pNew) );
    if( pNew==0 ) return SQLITE_NOMEM;
    memset(pNew, 0, sizeof(*pNew));
  }
  return rc;
}
................................................................................
  return rc;
}

/* Reset a JsonEachCursor back to its original state.  Free any memory
** held. */
static void jsonEachCursorReset(JsonEachCursor *p){
  sqlite3_free(p->zJson);
  sqlite3_free(p->zRoot);
  jsonParseReset(&p->sParse);
  p->iRowid = 0;
  p->i = 0;
  p->iEnd = 0;
  p->eType = 0;
  p->zJson = 0;
  p->zRoot = 0;
}

/* Destructor for a jsonEachCursor object */
static int jsonEachClose(sqlite3_vtab_cursor *cur){
  JsonEachCursor *p = (JsonEachCursor*)cur;
  jsonEachCursorReset(p);
  sqlite3_free(cur);
................................................................................
  return p->i >= p->iEnd;
}

/* Advance the cursor to the next element for json_tree() */
static int jsonEachNext(sqlite3_vtab_cursor *cur){
  JsonEachCursor *p = (JsonEachCursor*)cur;
  if( p->bRecursive ){
    if( p->sParse.aNode[p->i].jnFlags & JNODE_LABEL ) p->i++;




    p->i++;


    p->iRowid++;
    if( p->i<p->iEnd ){
      u32 iUp = p->sParse.aUp[p->i];
      JsonNode *pUp = &p->sParse.aNode[iUp];
      p->eType = pUp->eType;
      if( pUp->eType==JSON_ARRAY ){
        if( iUp==p->i-1 ){
          pUp->u.iKey = 0;
        }else{
................................................................................
  jsonEachComputePath(p, pStr, iUp);
  pNode = &p->sParse.aNode[i];
  pUp = &p->sParse.aNode[iUp];
  if( pUp->eType==JSON_ARRAY ){
    jsonPrintf(30, pStr, "[%d]", pUp->u.iKey);
  }else{
    assert( pUp->eType==JSON_OBJECT );
    if( (pNode->jnFlags & JNODE_LABEL)==0 ) pNode--;
    assert( pNode->eType==JSON_STRING );
    assert( pNode->jnFlags & JNODE_LABEL );
    jsonPrintf(pNode->n+1, pStr, ".%.*s", pNode->n-2, pNode->u.zJContent+1);
  }
}

/* Return the value of a column */
static int jsonEachColumn(
  sqlite3_vtab_cursor *cur,   /* The cursor */
................................................................................
          iKey = p->iRowid;
        }
        sqlite3_result_int64(ctx, (sqlite3_int64)iKey);
      }
      break;
    }
    case JEACH_VALUE: {
      if( pThis->jnFlags & JNODE_LABEL ) pThis++;
      jsonReturn(pThis, ctx, 0);
      break;
    }
    case JEACH_TYPE: {
      if( pThis->jnFlags & JNODE_LABEL ) pThis++;
      sqlite3_result_text(ctx, jsonType[pThis->eType], -1, SQLITE_STATIC);
      break;
    }
    case JEACH_ATOM: {
      if( pThis->jnFlags & JNODE_LABEL ) pThis++;
      if( pThis->eType>=JSON_ARRAY ) break;
      jsonReturn(pThis, ctx, 0);
      break;
    }
    case JEACH_ID: {
      sqlite3_result_int64(ctx, 
         (sqlite3_int64)p->i + ((pThis->jnFlags & JNODE_LABEL)!=0));
      break;
    }
    case JEACH_PARENT: {
      if( p->i>p->iBegin && p->bRecursive ){
        sqlite3_result_int64(ctx, (sqlite3_int64)p->sParse.aUp[p->i]);
      }
      break;
    }
    case JEACH_FULLKEY: {
      JsonString x;
      jsonInit(&x, ctx);
      if( p->bRecursive ){
        jsonEachComputePath(p, &x, p->i);
      }else{
        if( p->zRoot ){
          jsonAppendRaw(&x, p->zRoot, (int)strlen(p->zRoot));
        }else{
          jsonAppendChar(&x, '$');
        }
        if( p->eType==JSON_ARRAY ){
          jsonPrintf(30, &x, "[%d]", p->iRowid);
        }else{
          jsonPrintf(pThis->n, &x, ".%.*s", pThis->n-2, pThis->u.zJContent+1);
        }
      }
      jsonResult(&x);
      break;
    }
    case JEACH_PATH: {


      if( p->bRecursive ){
        JsonString x;
        jsonInit(&x, ctx);
        jsonEachComputePath(p, &x, p->sParse.aUp[p->i]);
        jsonResult(&x);
        break;
      }

      /* For json_each() path and root are the same so fall through
      ** into the root case */
    }
    case JEACH_ROOT: {
      const char *zRoot = p->zRoot;
       if( zRoot==0 ) zRoot = "$";
      sqlite3_result_text(ctx, zRoot, -1, SQLITE_STATIC);
      break;
    }
    default: {
      assert( i==JEACH_JSON );
      sqlite3_result_text(ctx, p->sParse.zJson, -1, SQLITE_STATIC);
      break;
    }
................................................................................
  JsonEachCursor *p = (JsonEachCursor*)cur;
  *pRowid = p->iRowid;
  return SQLITE_OK;
}

/* The query strategy is to look for an equality constraint on the json
** column.  Without such a constraint, the table cannot operate.  idxNum is
** 1 if the constraint is found, 3 if the constraint and zRoot are found,
** and 0 otherwise.
*/
static int jsonEachBestIndex(
  sqlite3_vtab *tab,
  sqlite3_index_info *pIdxInfo
){
  int i;
  int jsonIdx = -1;
  int rootIdx = -1;
  const struct sqlite3_index_constraint *pConstraint;

  UNUSED_PARAM(tab);
  pConstraint = pIdxInfo->aConstraint;
  for(i=0; i<pIdxInfo->nConstraint; i++, pConstraint++){
    if( pConstraint->usable==0 ) continue;
    if( pConstraint->op!=SQLITE_INDEX_CONSTRAINT_EQ ) continue;
    switch( pConstraint->iColumn ){
      case JEACH_JSON:   jsonIdx = i;    break;
      case JEACH_ROOT:   rootIdx = i;    break;
      default:           /* no-op */     break;
    }
  }
  if( jsonIdx<0 ){
    pIdxInfo->idxNum = 0;
    pIdxInfo->estimatedCost = 1e99;
  }else{
    pIdxInfo->estimatedCost = 1.0;
    pIdxInfo->aConstraintUsage[jsonIdx].argvIndex = 1;
    pIdxInfo->aConstraintUsage[jsonIdx].omit = 1;
    if( rootIdx<0 ){
      pIdxInfo->idxNum = 1;
    }else{
      pIdxInfo->aConstraintUsage[rootIdx].argvIndex = 2;
      pIdxInfo->aConstraintUsage[rootIdx].omit = 1;
      pIdxInfo->idxNum = 3;
    }
  }
  return SQLITE_OK;
}

/* Start a search on a new JSON string */
................................................................................
static int jsonEachFilter(
  sqlite3_vtab_cursor *cur,
  int idxNum, const char *idxStr,
  int argc, sqlite3_value **argv
){
  JsonEachCursor *p = (JsonEachCursor*)cur;
  const char *z;
  const char *zRoot = 0;
  sqlite3_int64 n;

  UNUSED_PARAM(idxStr);
  UNUSED_PARAM(argc);
  jsonEachCursorReset(p);
  if( idxNum==0 ) return SQLITE_OK;
  z = (const char*)sqlite3_value_text(argv[0]);
  if( z==0 ) return SQLITE_OK;
  if( idxNum&2 ){
    zRoot = (const char*)sqlite3_value_text(argv[1]);
    if( zRoot==0 ) return SQLITE_OK;
    if( zRoot[0]!='$' ){
      sqlite3_free(cur->pVtab->zErrMsg);
      cur->pVtab->zErrMsg = jsonPathSyntaxError(zRoot);
      return cur->pVtab->zErrMsg ? SQLITE_ERROR : SQLITE_NOMEM;
    }
  }
  n = sqlite3_value_bytes(argv[0]);
  p->zJson = sqlite3_malloc64( n+1 );
  if( p->zJson==0 ) return SQLITE_NOMEM;
  memcpy(p->zJson, z, (size_t)n+1);
................................................................................
  }else if( p->bRecursive && jsonParseFindParents(&p->sParse) ){
    jsonEachCursorReset(p);
    return SQLITE_NOMEM;
  }else{
    JsonNode *pNode;
    if( idxNum==3 ){
      const char *zErr = 0;

      n = sqlite3_value_bytes(argv[1]);
      p->zRoot = sqlite3_malloc64( n+1 );
      if( p->zRoot==0 ) return SQLITE_NOMEM;

      memcpy(p->zRoot, zRoot, (size_t)n+1);
      pNode = jsonLookupStep(&p->sParse, 0, p->zRoot+1, 0, &zErr);
      if( p->sParse.nErr ){
        sqlite3_free(cur->pVtab->zErrMsg);
        cur->pVtab->zErrMsg = jsonPathSyntaxError(zErr);
        jsonEachCursorReset(p);
        return cur->pVtab->zErrMsg ? SQLITE_ERROR : SQLITE_NOMEM;
      }else if( pNode==0 ){
        return SQLITE_OK;
      }
    }else{
      pNode = p->sParse.aNode;
    }
    p->iBegin = p->i = (int)(pNode - p->sParse.aNode);
    p->eType = pNode->eType;
    if( p->eType>=JSON_ARRAY ){
      pNode->u.iKey = 0;
      p->iEnd = p->i + pNode->n + 1;
      if( p->bRecursive ){
        if( p->i>0 && (p->sParse.aNode[p->i-1].jnFlags & JNODE_LABEL)!=0 ){
          p->i--;
        }
      }else{
        p->i++;
      }
    }else{
      p->iEnd = p->i+1;
    }
  }
  return p->sParse.oom ? SQLITE_NOMEM : SQLITE_OK;
}

................................................................................
  unsigned int i;
  static const struct {
     const char *zName;
     int nArg;
     int flag;
     void (*xFunc)(sqlite3_context*,int,sqlite3_value**);
  } aFunc[] = {
    { "json",                 1, 0,   jsonRemoveFunc        },
    { "json_array",          -1, 0,   jsonArrayFunc         },
    { "json_array_length",    1, 0,   jsonArrayLengthFunc   },
    { "json_array_length",    2, 0,   jsonArrayLengthFunc   },
    { "json_extract",        -1, 0,   jsonExtractFunc       },
    { "json_insert",         -1, 0,   jsonSetFunc           },
    { "json_object",         -1, 0,   jsonObjectFunc        },
    { "json_remove",         -1, 0,   jsonRemoveFunc        },
................................................................................
    { "json_type",            2, 0,   jsonTypeFunc          },
    { "json_valid",           1, 0,   jsonValidFunc         },

#if SQLITE_DEBUG
    /* DEBUG and TESTING functions */
    { "json_parse",           1, 0,   jsonParseFunc         },
    { "json_test1",           1, 0,   jsonTest1Func         },

#endif
  };
#ifndef SQLITE_OMIT_VIRTUALTABLE
  static const struct {
     const char *zName;
     sqlite3_module *pModule;
  } aMod[] = {

  for(i=0; i<=pCur->iPage; i++){
    releasePage(pCur->apPage[i]);
    pCur->apPage[i] = 0;
  }
  pCur->iPage = -1;
}













































/*
** Save the current cursor position in the variables BtCursor.nKey 
** and BtCursor.pKey. The cursor's state is set to CURSOR_REQUIRESEEK.
**
** The caller must ensure that the cursor is valid (has eState==CURSOR_VALID)
** prior to calling this routine.  
................................................................................
  assert( cursorHoldsMutex(pCur) );

  if( pCur->eState==CURSOR_SKIPNEXT ){
    pCur->eState = CURSOR_VALID;
  }else{
    pCur->skipNext = 0;
  }
  rc = sqlite3BtreeKeySize(pCur, &pCur->nKey);
  assert( rc==SQLITE_OK );  /* KeySize() cannot fail */

  /* If this is an intKey table, then the above call to BtreeKeySize()
  ** stores the integer key in pCur->nKey. In this case this value is
  ** all that is required. Otherwise, if pCur is not open on an intKey
  ** table, then malloc space for and store the pCur->nKey bytes of key 
  ** data.
  */
  if( 0==pCur->curIntKey ){
    void *pKey = sqlite3Malloc( pCur->nKey );
    if( pKey ){
      rc = sqlite3BtreeKey(pCur, 0, (int)pCur->nKey, pKey);
      if( rc==SQLITE_OK ){
        pCur->pKey = pKey;
      }else{
        sqlite3_free(pKey);
      }
    }else{
      rc = SQLITE_NOMEM;
    }
  }
  assert( !pCur->curIntKey || !pCur->pKey );


  if( rc==SQLITE_OK ){
    btreeReleaseAllCursorPages(pCur);
    pCur->eState = CURSOR_REQUIRESEEK;
  }

  invalidateOverflowCache(pCur);
  return rc;
................................................................................
  assert( pCur->apPage[pCur->iPage]->nOverflow==0 );

end_insert:
  return rc;
}

/*
** Delete the entry that the cursor is pointing to.  The cursor

** is left pointing at an arbitrary location.




*/
int sqlite3BtreeDelete(BtCursor *pCur){
  Btree *p = pCur->pBtree;
  BtShared *pBt = p->pBt;              
  int rc;                              /* Return code */
  MemPage *pPage;                      /* Page to delete cell from */
  unsigned char *pCell;                /* Pointer to cell to delete */
  int iCellIdx;                        /* Index of cell to delete */
  int iCellDepth;                      /* Depth of node containing pCell */ 
  u16 szCell;                          /* Size of the cell being deleted */


  assert( cursorHoldsMutex(pCur) );
  assert( pBt->inTransaction==TRANS_WRITE );
  assert( (pBt->btsFlags & BTS_READ_ONLY)==0 );
  assert( pCur->curFlags & BTCF_WriteFlag );
  assert( hasSharedCacheTableLock(p, pCur->pgnoRoot, pCur->pKeyInfo!=0, 2) );
  assert( !hasReadConflicts(p, pCur->pgnoRoot) );
................................................................................
  if( !pPage->leaf ){
    int notUsed = 0;
    rc = sqlite3BtreePrevious(pCur, &notUsed);
    if( rc ) return rc;
  }

  /* Save the positions of any other cursors open on this table before
  ** making any modifications. Make the page containing the entry to be 
  ** deleted writable. Then free any overflow pages associated with the 
  ** entry and finally remove the cell itself from within the page.  
  */
  if( pCur->curFlags & BTCF_Multiple ){
    rc = saveAllCursors(pBt, pCur->pgnoRoot, pCur);
    if( rc ) return rc;
  }

  /* If this is a delete operation to remove a row from a table b-tree,
  ** invalidate any incrblob cursors open on the row being deleted.  */
  if( pCur->pKeyInfo==0 ){
    invalidateIncrblobCursors(p, pCur->info.nKey, 0);
  }


























  rc = sqlite3PagerWrite(pPage->pDbPage);
  if( rc ) return rc;
  rc = clearCell(pPage, pCell, &szCell);
  dropCell(pPage, iCellIdx, szCell, &rc);
  if( rc ) return rc;

  /* If the cell deleted was not located on a leaf page, then the cursor
................................................................................
    while( pCur->iPage>iCellDepth ){
      releasePage(pCur->apPage[pCur->iPage--]);
    }
    rc = balance(pCur);
  }

  if( rc==SQLITE_OK ){











    moveToRoot(pCur);




  }
  return rc;
}

/*
** Create a new BTree table.  Write into *piTable the page
** number for the root page of the new table.

  for(i=0; i<=pCur->iPage; i++){
    releasePage(pCur->apPage[i]);
    pCur->apPage[i] = 0;
  }
  pCur->iPage = -1;
}

/*
** The cursor passed as the only argument must point to a valid entry
** when this function is called (i.e. have eState==CURSOR_VALID). This
** function saves the current cursor key in variables pCur->nKey and
** pCur->pKey. SQLITE_OK is returned if successful or an SQLite error 
** code otherwise.
**
** If the cursor is open on an intkey table, then the integer key
** (the rowid) is stored in pCur->nKey and pCur->pKey is left set to
** NULL. If the cursor is open on a non-intkey table, then pCur->pKey is 
** set to point to a malloced buffer pCur->nKey bytes in size containing 
** the key.
*/
static int saveCursorKey(BtCursor *pCur){
  int rc;
  assert( CURSOR_VALID==pCur->eState );
  assert( 0==pCur->pKey );
  assert( cursorHoldsMutex(pCur) );

  rc = sqlite3BtreeKeySize(pCur, &pCur->nKey);
  assert( rc==SQLITE_OK );  /* KeySize() cannot fail */

  /* If this is an intKey table, then the above call to BtreeKeySize()
  ** stores the integer key in pCur->nKey. In this case this value is
  ** all that is required. Otherwise, if pCur is not open on an intKey
  ** table, then malloc space for and store the pCur->nKey bytes of key 
  ** data.  */
  if( 0==pCur->curIntKey ){
    void *pKey = sqlite3Malloc( pCur->nKey );
    if( pKey ){
      rc = sqlite3BtreeKey(pCur, 0, (int)pCur->nKey, pKey);
      if( rc==SQLITE_OK ){
        pCur->pKey = pKey;
      }else{
        sqlite3_free(pKey);
      }
    }else{
      rc = SQLITE_NOMEM;
    }
  }
  assert( !pCur->curIntKey || !pCur->pKey );
  return rc;
}

/*
** Save the current cursor position in the variables BtCursor.nKey 
** and BtCursor.pKey. The cursor's state is set to CURSOR_REQUIRESEEK.
**
** The caller must ensure that the cursor is valid (has eState==CURSOR_VALID)
** prior to calling this routine.  
................................................................................
  assert( cursorHoldsMutex(pCur) );

  if( pCur->eState==CURSOR_SKIPNEXT ){
    pCur->eState = CURSOR_VALID;
  }else{
    pCur->skipNext = 0;
  }
























  rc = saveCursorKey(pCur);
  if( rc==SQLITE_OK ){
    btreeReleaseAllCursorPages(pCur);
    pCur->eState = CURSOR_REQUIRESEEK;
  }

  invalidateOverflowCache(pCur);
  return rc;
................................................................................
  assert( pCur->apPage[pCur->iPage]->nOverflow==0 );

end_insert:
  return rc;
}

/*
** Delete the entry that the cursor is pointing to. 
**
** If the second parameter is zero, then the cursor is left pointing at an
** arbitrary location after the delete. If it is non-zero, then the cursor 
** is left in a state such that the next call to BtreeNext() or BtreePrev()
** moves it to the same row as it would if the call to BtreeDelete() had
** been omitted.
*/
int sqlite3BtreeDelete(BtCursor *pCur, int bPreserve){
  Btree *p = pCur->pBtree;
  BtShared *pBt = p->pBt;              
  int rc;                              /* Return code */
  MemPage *pPage;                      /* Page to delete cell from */
  unsigned char *pCell;                /* Pointer to cell to delete */
  int iCellIdx;                        /* Index of cell to delete */
  int iCellDepth;                      /* Depth of node containing pCell */ 
  u16 szCell;                          /* Size of the cell being deleted */
  int bSkipnext = 0;                   /* Leaf cursor in SKIPNEXT state */

  assert( cursorHoldsMutex(pCur) );
  assert( pBt->inTransaction==TRANS_WRITE );
  assert( (pBt->btsFlags & BTS_READ_ONLY)==0 );
  assert( pCur->curFlags & BTCF_WriteFlag );
  assert( hasSharedCacheTableLock(p, pCur->pgnoRoot, pCur->pKeyInfo!=0, 2) );
  assert( !hasReadConflicts(p, pCur->pgnoRoot) );
................................................................................
  if( !pPage->leaf ){
    int notUsed = 0;
    rc = sqlite3BtreePrevious(pCur, &notUsed);
    if( rc ) return rc;
  }

  /* Save the positions of any other cursors open on this table before
  ** making any modifications.  */



  if( pCur->curFlags & BTCF_Multiple ){
    rc = saveAllCursors(pBt, pCur->pgnoRoot, pCur);
    if( rc ) return rc;
  }

  /* If this is a delete operation to remove a row from a table b-tree,
  ** invalidate any incrblob cursors open on the row being deleted.  */
  if( pCur->pKeyInfo==0 ){
    invalidateIncrblobCursors(p, pCur->info.nKey, 0);
  }

  /* If the bPreserve flag is set to true, then the cursor position must
  ** be preserved following this delete operation. If the current delete
  ** will cause a b-tree rebalance, then this is done by saving the cursor
  ** key and leaving the cursor in CURSOR_REQUIRESEEK state before 
  ** returning. 
  **
  ** Or, if the current delete will not cause a rebalance, then the cursor
  ** will be left in CURSOR_SKIPNEXT state pointing to the entry immediately
  ** before or after the deleted entry. In this case set bSkipnext to true.  */
  if( bPreserve ){
    if( !pPage->leaf 
     || (pPage->nFree+cellSizePtr(pPage,pCell)+2)>(int)(pBt->usableSize*2/3)
    ){
      /* A b-tree rebalance will be required after deleting this entry.
      ** Save the cursor key.  */
      rc = saveCursorKey(pCur);
      if( rc ) return rc;
    }else{
      bSkipnext = 1;
    }
  }

  /* Make the page containing the entry to be deleted writable. Then free any
  ** overflow pages associated with the entry and finally remove the cell
  ** itself from within the page.  */
  rc = sqlite3PagerWrite(pPage->pDbPage);
  if( rc ) return rc;
  rc = clearCell(pPage, pCell, &szCell);
  dropCell(pPage, iCellIdx, szCell, &rc);
  if( rc ) return rc;

  /* If the cell deleted was not located on a leaf page, then the cursor
................................................................................
    while( pCur->iPage>iCellDepth ){
      releasePage(pCur->apPage[pCur->iPage--]);
    }
    rc = balance(pCur);
  }

  if( rc==SQLITE_OK ){
    if( bSkipnext ){
      assert( bPreserve && pCur->iPage==iCellDepth );
      assert( pPage->nCell>0 && iCellIdx<=pPage->nCell );
      pCur->eState = CURSOR_SKIPNEXT;
      if( iCellIdx>=pPage->nCell ){
        pCur->skipNext = -1;
        pCur->aiIdx[iCellDepth] = pPage->nCell-1;
      }else{
        pCur->skipNext = 1;
      }
    }else{
      rc = moveToRoot(pCur);
      if( bPreserve ){
        pCur->eState = CURSOR_REQUIRESEEK;
      }
    }
  }
  return rc;
}

/*
** Create a new BTree table.  Write into *piTable the page
** number for the root page of the new table.

  UnpackedRecord *pUnKey,
  i64 intKey,
  int bias,
  int *pRes
);
int sqlite3BtreeCursorHasMoved(BtCursor*);
int sqlite3BtreeCursorRestore(BtCursor*, int*);
int sqlite3BtreeDelete(BtCursor*);
int sqlite3BtreeInsert(BtCursor*, const void *pKey, i64 nKey,
                                  const void *pData, int nData,
                                  int nZero, int bias, int seekResult);
int sqlite3BtreeFirst(BtCursor*, int *pRes);
int sqlite3BtreeLast(BtCursor*, int *pRes);
int sqlite3BtreeNext(BtCursor*, int *pRes);
int sqlite3BtreeEof(BtCursor*);

  UnpackedRecord *pUnKey,
  i64 intKey,
  int bias,
  int *pRes
);
int sqlite3BtreeCursorHasMoved(BtCursor*);
int sqlite3BtreeCursorRestore(BtCursor*, int*);
int sqlite3BtreeDelete(BtCursor*, int);
int sqlite3BtreeInsert(BtCursor*, const void *pKey, i64 nKey,
                                  const void *pData, int nData,
                                  int nZero, int bias, int seekResult);
int sqlite3BtreeFirst(BtCursor*, int *pRes);
int sqlite3BtreeLast(BtCursor*, int *pRes);
int sqlite3BtreeNext(BtCursor*, int *pRes);
int sqlite3BtreeEof(BtCursor*);

    return 0;
  }

  p = sqlite3FindTable(pParse->db, zName, zDbase);
  if( p==0 ){
    const char *zMsg = isView ? "no such view" : "no such table";
#ifndef SQLITE_OMIT_VIRTUALTABLE

    /* If zName is the not the name of a table in the schema created using
    ** CREATE, then check to see if it is the name of an virtual table that
    ** can be an eponymous virtual table. */
    Module *pMod = (Module*)sqlite3HashFind(&pParse->db->aModule, zName);
    if( pMod && sqlite3VtabEponymousTableInit(pParse, pMod) ){
      return pMod->pEpoTab;

    }
#endif
    if( zDbase ){
      sqlite3ErrorMsg(pParse, "%s: %s.%s", zMsg, zDbase, zName);
    }else{
      sqlite3ErrorMsg(pParse, "%s: %s", zMsg, zName);
    }
    pParse->checkSchema = 1;
  }
#if SQLITE_USER_AUTHENICATION
  else if( pParse->db->auth.authLevel<UAUTH_User ){
    sqlite3ErrorMsg(pParse, "user not authenticated");
    p = 0;
  }
#endif
  return p;
}
................................................................................
  ** indices.  Hence, the record number for the table must be allocated
  ** now.
  */
  if( !db->init.busy && (v = sqlite3GetVdbe(pParse))!=0 ){
    int j1;
    int fileFormat;
    int reg1, reg2, reg3;


    sqlite3BeginWriteOperation(pParse, 1, iDb);

#ifndef SQLITE_OMIT_VIRTUALTABLE
    if( isVirtual ){
      sqlite3VdbeAddOp0(v, OP_VBegin);
    }
#endif
................................................................................
    }else
#endif
    {
      pParse->addrCrTab = sqlite3VdbeAddOp2(v, OP_CreateTable, iDb, reg2);
    }
    sqlite3OpenMasterTable(pParse, iDb);
    sqlite3VdbeAddOp2(v, OP_NewRowid, 0, reg1);
    sqlite3VdbeAddOp2(v, OP_Null, 0, reg3);
    sqlite3VdbeAddOp3(v, OP_Insert, 0, reg3, reg1);
    sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
    sqlite3VdbeAddOp0(v, OP_Close);
  }

  /* Normal (non-error) return. */
  return;

    return 0;
  }

  p = sqlite3FindTable(pParse->db, zName, zDbase);
  if( p==0 ){
    const char *zMsg = isView ? "no such view" : "no such table";
#ifndef SQLITE_OMIT_VIRTUALTABLE
    if( sqlite3FindDbName(pParse->db, zDbase)<1 ){
      /* If zName is the not the name of a table in the schema created using
      ** CREATE, then check to see if it is the name of an virtual table that
      ** can be an eponymous virtual table. */
      Module *pMod = (Module*)sqlite3HashFind(&pParse->db->aModule, zName);
      if( pMod && sqlite3VtabEponymousTableInit(pParse, pMod) ){
        return pMod->pEpoTab;
      }
    }
#endif
    if( zDbase ){
      sqlite3ErrorMsg(pParse, "%s: %s.%s", zMsg, zDbase, zName);
    }else{
      sqlite3ErrorMsg(pParse, "%s: %s", zMsg, zName);
    }
    pParse->checkSchema = 1;
  }
#if SQLITE_USER_AUTHENTICATION
  else if( pParse->db->auth.authLevel<UAUTH_User ){
    sqlite3ErrorMsg(pParse, "user not authenticated");
    p = 0;
  }
#endif
  return p;
}
................................................................................
  ** indices.  Hence, the record number for the table must be allocated
  ** now.
  */
  if( !db->init.busy && (v = sqlite3GetVdbe(pParse))!=0 ){
    int j1;
    int fileFormat;
    int reg1, reg2, reg3;
    /* nullRow[] is an OP_Record encoding of a row containing 5 NULLs */
    static const char nullRow[] = { 6, 0, 0, 0, 0, 0 };
    sqlite3BeginWriteOperation(pParse, 1, iDb);

#ifndef SQLITE_OMIT_VIRTUALTABLE
    if( isVirtual ){
      sqlite3VdbeAddOp0(v, OP_VBegin);
    }
#endif
................................................................................
    }else
#endif
    {
      pParse->addrCrTab = sqlite3VdbeAddOp2(v, OP_CreateTable, iDb, reg2);
    }
    sqlite3OpenMasterTable(pParse, iDb);
    sqlite3VdbeAddOp2(v, OP_NewRowid, 0, reg1);
    sqlite3VdbeAddOp4(v, OP_Blob, 6, reg3, 0, nullRow, P4_STATIC);
    sqlite3VdbeAddOp3(v, OP_Insert, 0, reg3, reg1);
    sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
    sqlite3VdbeAddOp0(v, OP_Close);
  }

  /* Normal (non-error) return. */
  return;

**
** This file contains an implementation of the "dbstat" virtual table.
**
** The dbstat virtual table is used to extract low-level formatting
** information from an SQLite database in order to implement the
** "sqlite3_analyzer" utility.  See the ../tool/spaceanal.tcl script
** for an example implementation.



*/

#include "sqliteInt.h"   /* Requires access to internal data structures */
#if (defined(SQLITE_ENABLE_DBSTAT_VTAB) || defined(SQLITE_TEST)) \
    && !defined(SQLITE_OMIT_VIRTUALTABLE)

/*
................................................................................
  "  pageno     INTEGER,          /* Page number */"                        \
  "  pagetype   STRING,           /* 'internal', 'leaf' or 'overflow' */"   \
  "  ncell      INTEGER,          /* Cells on page (0 for overflow) */"     \
  "  payload    INTEGER,          /* Bytes of payload on this page */"      \
  "  unused     INTEGER,          /* Bytes of unused space on this page */" \
  "  mx_payload INTEGER,          /* Largest payload size of all cells */"  \
  "  pgoffset   INTEGER,          /* Offset of page in file */"             \
  "  pgsize     INTEGER           /* Size of the page */"                   \

  ");"


typedef struct StatTable StatTable;
typedef struct StatCursor StatCursor;
typedef struct StatPage StatPage;
typedef struct StatCell StatCell;
................................................................................
  int nMxPayload;                 /* Largest payload of any cell on this page */
};

struct StatCursor {
  sqlite3_vtab_cursor base;
  sqlite3_stmt *pStmt;            /* Iterates through set of root pages */
  int isEof;                      /* After pStmt has returned SQLITE_DONE */


  StatPage aPage[32];
  int iPage;                      /* Current entry in aPage[] */

  /* Values to return. */
  char *zName;                    /* Value of 'name' column */
  char *zPath;                    /* Value of 'path' column */
................................................................................
static int statDisconnect(sqlite3_vtab *pVtab){
  sqlite3_free(pVtab);
  return SQLITE_OK;
}

/*
** There is no "best-index". This virtual table always does a linear
** scan of the binary VFS log file.



*/
static int statBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){





















  /* Records are always returned in ascending order of (name, path). 
  ** If this will satisfy the client, set the orderByConsumed flag so that 
  ** SQLite does not do an external sort.
  */
  if( ( pIdxInfo->nOrderBy==1
     && pIdxInfo->aOrderBy[0].iColumn==0
................................................................................
     && pIdxInfo->aOrderBy[1].iColumn==1
     && pIdxInfo->aOrderBy[1].desc==0
     )
  ){
    pIdxInfo->orderByConsumed = 1;
  }

  pIdxInfo->estimatedCost = 10.0;
  return SQLITE_OK;
}

/*
** Open a new statvfs cursor.
*/
static int statOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
  StatTable *pTab = (StatTable *)pVTab;
  StatCursor *pCsr;
  int rc;

  pCsr = (StatCursor *)sqlite3_malloc64(sizeof(StatCursor));
  if( pCsr==0 ){
    rc = SQLITE_NOMEM;
  }else{
    char *zSql;
    memset(pCsr, 0, sizeof(StatCursor));
    pCsr->base.pVtab = pVTab;

    zSql = sqlite3_mprintf(
        "SELECT 'sqlite_master' AS name, 1 AS rootpage, 'table' AS type"
        "  UNION ALL  "
        "SELECT name, rootpage, type"
        "  FROM \"%w\".sqlite_master WHERE rootpage!=0"
        "  ORDER BY name", pTab->db->aDb[pTab->iDb].zName);
    if( zSql==0 ){
      rc = SQLITE_NOMEM;
    }else{
      rc = sqlite3_prepare_v2(pTab->db, zSql, -1, &pCsr->pStmt, 0);
      sqlite3_free(zSql);
    }
    if( rc!=SQLITE_OK ){
      sqlite3_free(pCsr);
      pCsr = 0;
    }

  }

  *ppCursor = (sqlite3_vtab_cursor *)pCsr;
  return rc;
}

static void statClearPage(StatPage *p){
  int i;
  if( p->aCell ){
    for(i=0; i<p->nCell; i++){
      sqlite3_free(p->aCell[i].aOvfl);
................................................................................
  sqlite3_reset(pCsr->pStmt);
  for(i=0; i<ArraySize(pCsr->aPage); i++){
    statClearPage(&pCsr->aPage[i]);
  }
  pCsr->iPage = 0;
  sqlite3_free(pCsr->zPath);
  pCsr->zPath = 0;

}

/*
** Close a statvfs cursor.
*/
static int statClose(sqlite3_vtab_cursor *pCursor){
  StatCursor *pCsr = (StatCursor *)pCursor;
................................................................................
*/
static int statNext(sqlite3_vtab_cursor *pCursor){
  int rc;
  int nPayload;
  char *z;
  StatCursor *pCsr = (StatCursor *)pCursor;
  StatTable *pTab = (StatTable *)pCursor->pVtab;
  Btree *pBt = pTab->db->aDb[pTab->iDb].pBt;
  Pager *pPager = sqlite3BtreePager(pBt);

  sqlite3_free(pCsr->zPath);
  pCsr->zPath = 0;

statNextRestart:
  if( pCsr->aPage[0].pPg==0 ){
................................................................................

static int statFilter(
  sqlite3_vtab_cursor *pCursor, 
  int idxNum, const char *idxStr,
  int argc, sqlite3_value **argv
){
  StatCursor *pCsr = (StatCursor *)pCursor;
















  statResetCsr(pCsr);

















  return statNext(pCursor);


}

static int statColumn(
  sqlite3_vtab_cursor *pCursor, 
  sqlite3_context *ctx, 
  int i
){
................................................................................
      break;
    case 7:            /* mx_payload */
      sqlite3_result_int(ctx, pCsr->nMxPayload);
      break;
    case 8:            /* pgoffset */
      sqlite3_result_int64(ctx, pCsr->iOffset);
      break;
    default:           /* pgsize */
      assert( i==9 );
      sqlite3_result_int(ctx, pCsr->szPage);
      break;






  }
  return SQLITE_OK;
}

static int statRowid(sqlite3_vtab_cursor *pCursor, sqlite_int64 *pRowid){
  StatCursor *pCsr = (StatCursor *)pCursor;
  *pRowid = pCsr->iPageno;

**
** This file contains an implementation of the "dbstat" virtual table.
**
** The dbstat virtual table is used to extract low-level formatting
** information from an SQLite database in order to implement the
** "sqlite3_analyzer" utility.  See the ../tool/spaceanal.tcl script
** for an example implementation.
**
** Additional information is available on the "dbstat.html" page of the
** official SQLite documentation.
*/

#include "sqliteInt.h"   /* Requires access to internal data structures */
#if (defined(SQLITE_ENABLE_DBSTAT_VTAB) || defined(SQLITE_TEST)) \
    && !defined(SQLITE_OMIT_VIRTUALTABLE)

/*
................................................................................
  "  pageno     INTEGER,          /* Page number */"                        \
  "  pagetype   STRING,           /* 'internal', 'leaf' or 'overflow' */"   \
  "  ncell      INTEGER,          /* Cells on page (0 for overflow) */"     \
  "  payload    INTEGER,          /* Bytes of payload on this page */"      \
  "  unused     INTEGER,          /* Bytes of unused space on this page */" \
  "  mx_payload INTEGER,          /* Largest payload size of all cells */"  \
  "  pgoffset   INTEGER,          /* Offset of page in file */"             \
  "  pgsize     INTEGER,          /* Size of the page */"                   \
  "  schema     TEXT HIDDEN       /* Database schema being analyzed */"     \
  ");"


typedef struct StatTable StatTable;
typedef struct StatCursor StatCursor;
typedef struct StatPage StatPage;
typedef struct StatCell StatCell;
................................................................................
  int nMxPayload;                 /* Largest payload of any cell on this page */
};

struct StatCursor {
  sqlite3_vtab_cursor base;
  sqlite3_stmt *pStmt;            /* Iterates through set of root pages */
  int isEof;                      /* After pStmt has returned SQLITE_DONE */
  int iDb;                        /* Schema used for this query */

  StatPage aPage[32];
  int iPage;                      /* Current entry in aPage[] */

  /* Values to return. */
  char *zName;                    /* Value of 'name' column */
  char *zPath;                    /* Value of 'path' column */
................................................................................
static int statDisconnect(sqlite3_vtab *pVtab){
  sqlite3_free(pVtab);
  return SQLITE_OK;
}

/*
** There is no "best-index". This virtual table always does a linear
** scan.  However, a schema=? constraint should cause this table to
** operate on a different database schema, so check for it.
**
** idxNum is normally 0, but will be 1 if a schema=? constraint exists.
*/
static int statBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
  int i;

  pIdxInfo->estimatedCost = 1.0e6;  /* Initial cost estimate */

  /* Look for a valid schema=? constraint.  If found, change the idxNum to
  ** 1 and request the value of that constraint be sent to xFilter.  And
  ** lower the cost estimate to encourage the constrained version to be
  ** used.
  */
  for(i=0; i<pIdxInfo->nConstraint; i++){
    if( pIdxInfo->aConstraint[i].usable==0 ) continue;
    if( pIdxInfo->aConstraint[i].op!=SQLITE_INDEX_CONSTRAINT_EQ ) continue;
    if( pIdxInfo->aConstraint[i].iColumn!=10 ) continue;
    pIdxInfo->idxNum = 1;
    pIdxInfo->estimatedCost = 1.0;
    pIdxInfo->aConstraintUsage[i].argvIndex = 1;
    pIdxInfo->aConstraintUsage[i].omit = 1;
    break;
  }


  /* Records are always returned in ascending order of (name, path). 
  ** If this will satisfy the client, set the orderByConsumed flag so that 
  ** SQLite does not do an external sort.
  */
  if( ( pIdxInfo->nOrderBy==1
     && pIdxInfo->aOrderBy[0].iColumn==0
................................................................................
     && pIdxInfo->aOrderBy[1].iColumn==1
     && pIdxInfo->aOrderBy[1].desc==0
     )
  ){
    pIdxInfo->orderByConsumed = 1;
  }


  return SQLITE_OK;
}

/*
** Open a new statvfs cursor.
*/
static int statOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
  StatTable *pTab = (StatTable *)pVTab;
  StatCursor *pCsr;


  pCsr = (StatCursor *)sqlite3_malloc64(sizeof(StatCursor));
  if( pCsr==0 ){
    return SQLITE_NOMEM;
  }else{

    memset(pCsr, 0, sizeof(StatCursor));
    pCsr->base.pVtab = pVTab;

















    pCsr->iDb = pTab->iDb;
  }

  *ppCursor = (sqlite3_vtab_cursor *)pCsr;
  return SQLITE_OK;
}

static void statClearPage(StatPage *p){
  int i;
  if( p->aCell ){
    for(i=0; i<p->nCell; i++){
      sqlite3_free(p->aCell[i].aOvfl);
................................................................................
  sqlite3_reset(pCsr->pStmt);
  for(i=0; i<ArraySize(pCsr->aPage); i++){
    statClearPage(&pCsr->aPage[i]);
  }
  pCsr->iPage = 0;
  sqlite3_free(pCsr->zPath);
  pCsr->zPath = 0;
  pCsr->isEof = 0;
}

/*
** Close a statvfs cursor.
*/
static int statClose(sqlite3_vtab_cursor *pCursor){
  StatCursor *pCsr = (StatCursor *)pCursor;
................................................................................
*/
static int statNext(sqlite3_vtab_cursor *pCursor){
  int rc;
  int nPayload;
  char *z;
  StatCursor *pCsr = (StatCursor *)pCursor;
  StatTable *pTab = (StatTable *)pCursor->pVtab;
  Btree *pBt = pTab->db->aDb[pCsr->iDb].pBt;
  Pager *pPager = sqlite3BtreePager(pBt);

  sqlite3_free(pCsr->zPath);
  pCsr->zPath = 0;

statNextRestart:
  if( pCsr->aPage[0].pPg==0 ){
................................................................................

static int statFilter(
  sqlite3_vtab_cursor *pCursor, 
  int idxNum, const char *idxStr,
  int argc, sqlite3_value **argv
){
  StatCursor *pCsr = (StatCursor *)pCursor;
  StatTable *pTab = (StatTable*)(pCursor->pVtab);
  char *zSql;
  int rc = SQLITE_OK;
  char *zMaster;

  if( idxNum==1 ){
    const char *zDbase = (const char*)sqlite3_value_text(argv[0]);
    pCsr->iDb = sqlite3FindDbName(pTab->db, zDbase);
    if( pCsr->iDb<0 ){
      sqlite3_free(pCursor->pVtab->zErrMsg);
      pCursor->pVtab->zErrMsg = sqlite3_mprintf("no such schema: %s", zDbase);
      return pCursor->pVtab->zErrMsg ? SQLITE_ERROR : SQLITE_NOMEM;
    }
  }else{
    pCsr->iDb = pTab->iDb;
  }
  statResetCsr(pCsr);
  sqlite3_finalize(pCsr->pStmt);
  pCsr->pStmt = 0;
  zMaster = pCsr->iDb==1 ? "sqlite_temp_master" : "sqlite_master";
  zSql = sqlite3_mprintf(
      "SELECT 'sqlite_master' AS name, 1 AS rootpage, 'table' AS type"
      "  UNION ALL  "
      "SELECT name, rootpage, type"
      "  FROM \"%w\".%s WHERE rootpage!=0"
      "  ORDER BY name", pTab->db->aDb[pCsr->iDb].zName, zMaster);
  if( zSql==0 ){
    return SQLITE_NOMEM;
  }else{
    rc = sqlite3_prepare_v2(pTab->db, zSql, -1, &pCsr->pStmt, 0);
    sqlite3_free(zSql);
  }

  if( rc==SQLITE_OK ){
    rc = statNext(pCursor);
  }
  return rc;
}

static int statColumn(
  sqlite3_vtab_cursor *pCursor, 
  sqlite3_context *ctx, 
  int i
){
................................................................................
      break;
    case 7:            /* mx_payload */
      sqlite3_result_int(ctx, pCsr->nMxPayload);
      break;
    case 8:            /* pgoffset */
      sqlite3_result_int64(ctx, pCsr->iOffset);
      break;
    case 9:            /* pgsize */

      sqlite3_result_int(ctx, pCsr->szPage);
      break;
    default: {          /* schema */
      sqlite3 *db = sqlite3_context_db_handle(ctx);
      int iDb = pCsr->iDb;
      sqlite3_result_text(ctx, db->aDb[iDb].zName, -1, SQLITE_STATIC);
      break;
    }
  }
  return SQLITE_OK;
}

static int statRowid(sqlite3_vtab_cursor *pCursor, sqlite_int64 *pRowid){
  StatCursor *pCsr = (StatCursor *)pCursor;
  *pRowid = pCsr->iPageno;

  int nIdx;              /* Number of indices */
  sqlite3 *db;           /* Main database structure */
  AuthContext sContext;  /* Authorization context */
  NameContext sNC;       /* Name context to resolve expressions in */
  int iDb;               /* Database number */
  int memCnt = -1;       /* Memory cell used for change counting */
  int rcauth;            /* Value returned by authorization callback */
  int okOnePass;         /* True for one-pass algorithm without the FIFO */
  int aiCurOnePass[2];   /* The write cursors opened by WHERE_ONEPASS */
  u8 *aToOpen = 0;       /* Open cursor iTabCur+j if aToOpen[j] is true */
  Index *pPk;            /* The PRIMARY KEY index on the table */
  int iPk = 0;           /* First of nPk registers holding PRIMARY KEY value */
  i16 nPk = 1;           /* Number of columns in the PRIMARY KEY */
  int iKey;              /* Memory cell holding key of row to be deleted */
  i16 nKey;              /* Number of memory cells in the row key */
  int iEphCur = 0;       /* Ephemeral table holding all primary key values */
  int iRowSet = 0;       /* Register for rowset of rows to delete */
  int addrBypass = 0;    /* Address of jump over the delete logic */
  int addrLoop = 0;      /* Top of the delete loop */
  int addrDelete = 0;    /* Jump directly to the delete logic */
  int addrEphOpen = 0;   /* Instruction to open the Ephemeral table */
 
#ifndef SQLITE_OMIT_TRIGGER
  int isView;                  /* True if attempting to delete from a view */
  Trigger *pTrigger;           /* List of table triggers, if required */

#endif

  memset(&sContext, 0, sizeof(sContext));
  db = pParse->db;
  if( pParse->nErr || db->mallocFailed ){
    goto delete_from_cleanup;
  }
................................................................................

  /* Figure out if we have any triggers and if the table being
  ** deleted from is a view
  */
#ifndef SQLITE_OMIT_TRIGGER
  pTrigger = sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0, 0);
  isView = pTab->pSelect!=0;

#else
# define pTrigger 0
# define isView 0

#endif
#ifdef SQLITE_OMIT_VIEW
# undef isView
# define isView 0
#endif

  /* If pTab is really a view, make sure it has been initialized.
................................................................................
  }

#ifndef SQLITE_OMIT_TRUNCATE_OPTIMIZATION
  /* Special case: A DELETE without a WHERE clause deletes everything.
  ** It is easier just to erase the whole table. Prior to version 3.6.5,
  ** this optimization caused the row change count (the value returned by 
  ** API function sqlite3_count_changes) to be set incorrectly.  */
  if( rcauth==SQLITE_OK && pWhere==0 && !pTrigger && !IsVirtual(pTab) 
   && 0==sqlite3FkRequired(pParse, pTab, 0, 0)


  ){
    assert( !isView );
    sqlite3TableLock(pParse, iDb, pTab->tnum, 1, pTab->zName);
    if( HasRowid(pTab) ){
      sqlite3VdbeAddOp4(v, OP_Clear, pTab->tnum, iDb, memCnt,
                        pTab->zName, P4_STATIC);
    }
................................................................................
    for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
      assert( pIdx->pSchema==pTab->pSchema );
      sqlite3VdbeAddOp2(v, OP_Clear, pIdx->tnum, iDb);
    }
  }else
#endif /* SQLITE_OMIT_TRUNCATE_OPTIMIZATION */
  {


    if( HasRowid(pTab) ){
      /* For a rowid table, initialize the RowSet to an empty set */
      pPk = 0;
      nPk = 1;
      iRowSet = ++pParse->nMem;
      sqlite3VdbeAddOp2(v, OP_Null, 0, iRowSet);
    }else{
................................................................................
      pParse->nMem += nPk;
      iEphCur = pParse->nTab++;
      addrEphOpen = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, iEphCur, nPk);
      sqlite3VdbeSetP4KeyInfo(pParse, pPk);
    }
  
    /* Construct a query to find the rowid or primary key for every row
    ** to be deleted, based on the WHERE clause.





    */
    pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0, 0, 
                               WHERE_ONEPASS_DESIRED|WHERE_DUPLICATES_OK,
                               iTabCur+1);
    if( pWInfo==0 ) goto delete_from_cleanup;
    okOnePass = sqlite3WhereOkOnePass(pWInfo, aiCurOnePass);

  
    /* Keep track of the number of rows to be deleted */
    if( db->flags & SQLITE_CountRows ){
      sqlite3VdbeAddOp2(v, OP_AddImm, memCnt, 1);
    }
  
    /* Extract the rowid or primary key for the current row */
................................................................................
      iKey = iPk;
    }else{
      iKey = pParse->nMem + 1;
      iKey = sqlite3ExprCodeGetColumn(pParse, pTab, -1, iTabCur, iKey, 0);
      if( iKey>pParse->nMem ) pParse->nMem = iKey;
    }
  
    if( okOnePass ){
      /* For ONEPASS, no need to store the rowid/primary-key.  There is only
      ** one, so just keep it in its register(s) and fall through to the
      ** delete code.
      */
      nKey = nPk; /* OP_Found will use an unpacked key */
      aToOpen = sqlite3DbMallocRaw(db, nIdx+2);
      if( aToOpen==0 ){
        sqlite3WhereEnd(pWInfo);
        goto delete_from_cleanup;
      }
      memset(aToOpen, 1, nIdx+1);
      aToOpen[nIdx+1] = 0;
      if( aiCurOnePass[0]>=0 ) aToOpen[aiCurOnePass[0]-iTabCur] = 0;
      if( aiCurOnePass[1]>=0 ) aToOpen[aiCurOnePass[1]-iTabCur] = 0;
      if( addrEphOpen ) sqlite3VdbeChangeToNoop(v, addrEphOpen);
      addrDelete = sqlite3VdbeAddOp0(v, OP_Goto); /* Jump to DELETE logic */
    }else if( pPk ){
      /* Construct a composite key for the row to be deleted and remember it */
      iKey = ++pParse->nMem;
      nKey = 0;   /* Zero tells OP_Found to use a composite key */
      sqlite3VdbeAddOp4(v, OP_MakeRecord, iPk, nPk, iKey,
                        sqlite3IndexAffinityStr(pParse->db, pPk), nPk);
      sqlite3VdbeAddOp2(v, OP_IdxInsert, iEphCur, iKey);
    }else{
      /* Get the rowid of the row to be deleted and remember it in the RowSet */
      nKey = 1;  /* OP_Seek always uses a single rowid */
      sqlite3VdbeAddOp2(v, OP_RowSetAdd, iRowSet, iKey);
    }
  


    /* End of the WHERE loop */
    sqlite3WhereEnd(pWInfo);
    if( okOnePass ){
      /* Bypass the delete logic below if the WHERE loop found zero rows */
      addrBypass = sqlite3VdbeMakeLabel(v);
      sqlite3VdbeGoto(v, addrBypass);
      sqlite3VdbeJumpHere(v, addrDelete);
    }
  
    /* Unless this is a view, open cursors for the table we are 
    ** deleting from and all its indices. If this is a view, then the
    ** only effect this statement has is to fire the INSTEAD OF 
    ** triggers.
    */
    if( !isView ){




      testcase( IsVirtual(pTab) );
      sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenWrite, iTabCur, aToOpen,
                                 &iDataCur, &iIdxCur);
      assert( pPk || IsVirtual(pTab) || iDataCur==iTabCur );
      assert( pPk || IsVirtual(pTab) || iIdxCur==iDataCur+1 );

    }
  
    /* Set up a loop over the rowids/primary-keys that were found in the
    ** where-clause loop above.
    */
    if( okOnePass ){
      /* Just one row.  Hence the top-of-loop is a no-op */
      assert( nKey==nPk );  /* OP_Found will use an unpacked key */
      assert( !IsVirtual(pTab) );
      if( aToOpen[iDataCur-iTabCur] ){
        assert( pPk!=0 || pTab->pSelect!=0 );
        sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, addrBypass, iKey, nKey);
        VdbeCoverage(v);
      }
    }else if( pPk ){
      addrLoop = sqlite3VdbeAddOp1(v, OP_Rewind, iEphCur); VdbeCoverage(v);
................................................................................
      sqlite3VdbeAddOp4(v, OP_VUpdate, 0, 1, iKey, pVTab, P4_VTAB);
      sqlite3VdbeChangeP5(v, OE_Abort);
      sqlite3MayAbort(pParse);
    }else
#endif
    {
      int count = (pParse->nested==0);    /* True to count changes */




      sqlite3GenerateRowDelete(pParse, pTab, pTrigger, iDataCur, iIdxCur,
                               iKey, nKey, count, OE_Default, okOnePass);
    }
  
    /* End of the loop over all rowids/primary-keys. */
    if( okOnePass ){
      sqlite3VdbeResolveLabel(v, addrBypass);

    }else if( pPk ){
      sqlite3VdbeAddOp2(v, OP_Next, iEphCur, addrLoop+1); VdbeCoverage(v);
      sqlite3VdbeJumpHere(v, addrLoop);
    }else{
      sqlite3VdbeGoto(v, addrLoop);
      sqlite3VdbeJumpHere(v, addrLoop);
    }     
................................................................................
**   2.  Read/write cursors for all indices of pTab must be open as
**       cursor number iIdxCur+i for the i-th index.
**
**   3.  The primary key for the row to be deleted must be stored in a
**       sequence of nPk memory cells starting at iPk.  If nPk==0 that means
**       that a search record formed from OP_MakeRecord is contained in the
**       single memory location iPk.



















*/
void sqlite3GenerateRowDelete(
  Parse *pParse,     /* Parsing context */
  Table *pTab,       /* Table containing the row to be deleted */
  Trigger *pTrigger, /* List of triggers to (potentially) fire */
  int iDataCur,      /* Cursor from which column data is extracted */
  int iIdxCur,       /* First index cursor */
  int iPk,           /* First memory cell containing the PRIMARY KEY */
  i16 nPk,           /* Number of PRIMARY KEY memory cells */
  u8 count,          /* If non-zero, increment the row change counter */
  u8 onconf,         /* Default ON CONFLICT policy for triggers */
  u8 bNoSeek         /* iDataCur is already pointing to the row to delete */

){
  Vdbe *v = pParse->pVdbe;        /* Vdbe */
  int iOld = 0;                   /* First register in OLD.* array */
  int iLabel;                     /* Label resolved to end of generated code */
  u8 opSeek;                      /* Seek opcode */

  /* Vdbe is guaranteed to have been allocated by this stage. */
................................................................................
                         iDataCur, iIdxCur, iPk, (int)nPk));

  /* Seek cursor iCur to the row to delete. If this row no longer exists 
  ** (this can happen if a trigger program has already deleted it), do
  ** not attempt to delete it or fire any DELETE triggers.  */
  iLabel = sqlite3VdbeMakeLabel(v);
  opSeek = HasRowid(pTab) ? OP_NotExists : OP_NotFound;
  if( !bNoSeek ){
    sqlite3VdbeAddOp4Int(v, opSeek, iDataCur, iLabel, iPk, nPk);
    VdbeCoverageIf(v, opSeek==OP_NotExists);
    VdbeCoverageIf(v, opSeek==OP_NotFound);
  }
 
  /* If there are any triggers to fire, allocate a range of registers to
  ** use for the old.* references in the triggers.  */
................................................................................
    sqlite3FkCheck(pParse, pTab, iOld, 0, 0, 0);
  }

  /* Delete the index and table entries. Skip this step if pTab is really
  ** a view (in which case the only effect of the DELETE statement is to
  ** fire the INSTEAD OF triggers).  */ 
  if( pTab->pSelect==0 ){
    sqlite3GenerateRowIndexDelete(pParse, pTab, iDataCur, iIdxCur, 0);
    sqlite3VdbeAddOp2(v, OP_Delete, iDataCur, (count?OPFLAG_NCHANGE:0));
    if( count ){
      sqlite3VdbeChangeP4(v, -1, pTab->zName, P4_TRANSIENT);
    }




  }

  /* Do any ON CASCADE, SET NULL or SET DEFAULT operations required to
  ** handle rows (possibly in other tables) that refer via a foreign key
  ** to the row just deleted. */ 
  sqlite3FkActions(pParse, pTab, 0, iOld, 0, 0);

................................................................................
**       that is to be deleted.
*/
void sqlite3GenerateRowIndexDelete(
  Parse *pParse,     /* Parsing and code generating context */
  Table *pTab,       /* Table containing the row to be deleted */
  int iDataCur,      /* Cursor of table holding data. */
  int iIdxCur,       /* First index cursor */
  int *aRegIdx       /* Only delete if aRegIdx!=0 && aRegIdx[i]>0 */

){
  int i;             /* Index loop counter */
  int r1 = -1;       /* Register holding an index key */
  int iPartIdxLabel; /* Jump destination for skipping partial index entries */
  Index *pIdx;       /* Current index */
  Index *pPrior = 0; /* Prior index */
  Vdbe *v;           /* The prepared statement under construction */
................................................................................

  v = pParse->pVdbe;
  pPk = HasRowid(pTab) ? 0 : sqlite3PrimaryKeyIndex(pTab);
  for(i=0, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
    assert( iIdxCur+i!=iDataCur || pPk==pIdx );
    if( aRegIdx!=0 && aRegIdx[i]==0 ) continue;
    if( pIdx==pPk ) continue;

    VdbeModuleComment((v, "GenRowIdxDel for %s", pIdx->zName));
    r1 = sqlite3GenerateIndexKey(pParse, pIdx, iDataCur, 0, 1,
                                 &iPartIdxLabel, pPrior, r1);
    sqlite3VdbeAddOp3(v, OP_IdxDelete, iIdxCur+i, r1,
                      pIdx->uniqNotNull ? pIdx->nKeyCol : pIdx->nColumn);
    sqlite3ResolvePartIdxLabel(pParse, iPartIdxLabel);
    pPrior = pIdx;
  }
}

/*
** Generate code that will assemble an index key and stores it in register

  int nIdx;              /* Number of indices */
  sqlite3 *db;           /* Main database structure */
  AuthContext sContext;  /* Authorization context */
  NameContext sNC;       /* Name context to resolve expressions in */
  int iDb;               /* Database number */
  int memCnt = -1;       /* Memory cell used for change counting */
  int rcauth;            /* Value returned by authorization callback */
  int eOnePass;          /* ONEPASS_OFF or _SINGLE or _MULTI */
  int aiCurOnePass[2];   /* The write cursors opened by WHERE_ONEPASS */
  u8 *aToOpen = 0;       /* Open cursor iTabCur+j if aToOpen[j] is true */
  Index *pPk;            /* The PRIMARY KEY index on the table */
  int iPk = 0;           /* First of nPk registers holding PRIMARY KEY value */
  i16 nPk = 1;           /* Number of columns in the PRIMARY KEY */
  int iKey;              /* Memory cell holding key of row to be deleted */
  i16 nKey;              /* Number of memory cells in the row key */
  int iEphCur = 0;       /* Ephemeral table holding all primary key values */
  int iRowSet = 0;       /* Register for rowset of rows to delete */
  int addrBypass = 0;    /* Address of jump over the delete logic */
  int addrLoop = 0;      /* Top of the delete loop */

  int addrEphOpen = 0;   /* Instruction to open the Ephemeral table */
 
#ifndef SQLITE_OMIT_TRIGGER
  int isView;                  /* True if attempting to delete from a view */
  Trigger *pTrigger;           /* List of table triggers, if required */
  int bComplex;                /* True if there are either triggers or FKs */
#endif

  memset(&sContext, 0, sizeof(sContext));
  db = pParse->db;
  if( pParse->nErr || db->mallocFailed ){
    goto delete_from_cleanup;
  }
................................................................................

  /* Figure out if we have any triggers and if the table being
  ** deleted from is a view
  */
#ifndef SQLITE_OMIT_TRIGGER
  pTrigger = sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0, 0);
  isView = pTab->pSelect!=0;
  bComplex = pTrigger || sqlite3FkRequired(pParse, pTab, 0, 0);
#else
# define pTrigger 0
# define isView 0
# define bComplex 0
#endif
#ifdef SQLITE_OMIT_VIEW
# undef isView
# define isView 0
#endif

  /* If pTab is really a view, make sure it has been initialized.
................................................................................
  }

#ifndef SQLITE_OMIT_TRUNCATE_OPTIMIZATION
  /* Special case: A DELETE without a WHERE clause deletes everything.
  ** It is easier just to erase the whole table. Prior to version 3.6.5,
  ** this optimization caused the row change count (the value returned by 
  ** API function sqlite3_count_changes) to be set incorrectly.  */
  if( rcauth==SQLITE_OK
   && pWhere==0
   && !bComplex
   && !IsVirtual(pTab)
  ){
    assert( !isView );
    sqlite3TableLock(pParse, iDb, pTab->tnum, 1, pTab->zName);
    if( HasRowid(pTab) ){
      sqlite3VdbeAddOp4(v, OP_Clear, pTab->tnum, iDb, memCnt,
                        pTab->zName, P4_STATIC);
    }
................................................................................
    for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
      assert( pIdx->pSchema==pTab->pSchema );
      sqlite3VdbeAddOp2(v, OP_Clear, pIdx->tnum, iDb);
    }
  }else
#endif /* SQLITE_OMIT_TRUNCATE_OPTIMIZATION */
  {
    u16 wcf = WHERE_ONEPASS_DESIRED|WHERE_DUPLICATES_OK;
    wcf |= (bComplex ? 0 : WHERE_ONEPASS_MULTIROW);
    if( HasRowid(pTab) ){
      /* For a rowid table, initialize the RowSet to an empty set */
      pPk = 0;
      nPk = 1;
      iRowSet = ++pParse->nMem;
      sqlite3VdbeAddOp2(v, OP_Null, 0, iRowSet);
    }else{
................................................................................
      pParse->nMem += nPk;
      iEphCur = pParse->nTab++;
      addrEphOpen = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, iEphCur, nPk);
      sqlite3VdbeSetP4KeyInfo(pParse, pPk);
    }
  
    /* Construct a query to find the rowid or primary key for every row
    ** to be deleted, based on the WHERE clause. Set variable eOnePass
    ** to indicate the strategy used to implement this delete:
    **
    **  ONEPASS_OFF:    Two-pass approach - use a FIFO for rowids/PK values.
    **  ONEPASS_SINGLE: One-pass approach - at most one row deleted.
    **  ONEPASS_MULTI:  One-pass approach - any number of rows may be deleted.
    */
    pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0, 0, wcf, iTabCur+1);


    if( pWInfo==0 ) goto delete_from_cleanup;
    eOnePass = sqlite3WhereOkOnePass(pWInfo, aiCurOnePass);
    assert( IsVirtual(pTab)==0 || eOnePass==ONEPASS_OFF );
  
    /* Keep track of the number of rows to be deleted */
    if( db->flags & SQLITE_CountRows ){
      sqlite3VdbeAddOp2(v, OP_AddImm, memCnt, 1);
    }
  
    /* Extract the rowid or primary key for the current row */
................................................................................
      iKey = iPk;
    }else{
      iKey = pParse->nMem + 1;
      iKey = sqlite3ExprCodeGetColumn(pParse, pTab, -1, iTabCur, iKey, 0);
      if( iKey>pParse->nMem ) pParse->nMem = iKey;
    }
  
    if( eOnePass!=ONEPASS_OFF ){
      /* For ONEPASS, no need to store the rowid/primary-key. There is only
      ** one, so just keep it in its register(s) and fall through to the
      ** delete code.  */

      nKey = nPk; /* OP_Found will use an unpacked key */
      aToOpen = sqlite3DbMallocRaw(db, nIdx+2);
      if( aToOpen==0 ){
        sqlite3WhereEnd(pWInfo);
        goto delete_from_cleanup;
      }
      memset(aToOpen, 1, nIdx+1);
      aToOpen[nIdx+1] = 0;
      if( aiCurOnePass[0]>=0 ) aToOpen[aiCurOnePass[0]-iTabCur] = 0;
      if( aiCurOnePass[1]>=0 ) aToOpen[aiCurOnePass[1]-iTabCur] = 0;
      if( addrEphOpen ) sqlite3VdbeChangeToNoop(v, addrEphOpen);
    }else{
      if( pPk ){
        /* Add the PK key for this row to the temporary table */
        iKey = ++pParse->nMem;
        nKey = 0;   /* Zero tells OP_Found to use a composite key */
        sqlite3VdbeAddOp4(v, OP_MakeRecord, iPk, nPk, iKey,
            sqlite3IndexAffinityStr(pParse->db, pPk), nPk);
        sqlite3VdbeAddOp2(v, OP_IdxInsert, iEphCur, iKey);
      }else{
        /* Add the rowid of the row to be deleted to the RowSet */
        nKey = 1;  /* OP_Seek always uses a single rowid */
        sqlite3VdbeAddOp2(v, OP_RowSetAdd, iRowSet, iKey);
      }
    }
  
    /* If this DELETE cannot use the ONEPASS strategy, this is the 
    ** end of the WHERE loop */


    if( eOnePass!=ONEPASS_OFF ){
      addrBypass = sqlite3VdbeMakeLabel(v);
    }else{
      sqlite3WhereEnd(pWInfo);
    }
  
    /* Unless this is a view, open cursors for the table we are 
    ** deleting from and all its indices. If this is a view, then the
    ** only effect this statement has is to fire the INSTEAD OF 
    ** triggers.
    */
    if( !isView ){
      int iAddrOnce = 0;
      if( eOnePass==ONEPASS_MULTI ){
        iAddrOnce = sqlite3CodeOnce(pParse); VdbeCoverage(v);
      }
      testcase( IsVirtual(pTab) );
      sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenWrite, iTabCur, aToOpen,
                                 &iDataCur, &iIdxCur);
      assert( pPk || IsVirtual(pTab) || iDataCur==iTabCur );
      assert( pPk || IsVirtual(pTab) || iIdxCur==iDataCur+1 );
      if( eOnePass==ONEPASS_MULTI ) sqlite3VdbeJumpHere(v, iAddrOnce);
    }
  
    /* Set up a loop over the rowids/primary-keys that were found in the
    ** where-clause loop above.
    */
    if( eOnePass!=ONEPASS_OFF ){

      assert( nKey==nPk );  /* OP_Found will use an unpacked key */

      if( aToOpen[iDataCur-iTabCur] ){
        assert( pPk!=0 || pTab->pSelect!=0 );
        sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, addrBypass, iKey, nKey);
        VdbeCoverage(v);
      }
    }else if( pPk ){
      addrLoop = sqlite3VdbeAddOp1(v, OP_Rewind, iEphCur); VdbeCoverage(v);
................................................................................
      sqlite3VdbeAddOp4(v, OP_VUpdate, 0, 1, iKey, pVTab, P4_VTAB);
      sqlite3VdbeChangeP5(v, OE_Abort);
      sqlite3MayAbort(pParse);
    }else
#endif
    {
      int count = (pParse->nested==0);    /* True to count changes */
      int iIdxNoSeek = -1;
      if( bComplex==0 && aiCurOnePass[1]!=iDataCur ){
        iIdxNoSeek = aiCurOnePass[1];
      }
      sqlite3GenerateRowDelete(pParse, pTab, pTrigger, iDataCur, iIdxCur,
          iKey, nKey, count, OE_Default, eOnePass, iIdxNoSeek);
    }
  
    /* End of the loop over all rowids/primary-keys. */
    if( eOnePass!=ONEPASS_OFF ){
      sqlite3VdbeResolveLabel(v, addrBypass);
      sqlite3WhereEnd(pWInfo);
    }else if( pPk ){
      sqlite3VdbeAddOp2(v, OP_Next, iEphCur, addrLoop+1); VdbeCoverage(v);
      sqlite3VdbeJumpHere(v, addrLoop);
    }else{
      sqlite3VdbeGoto(v, addrLoop);
      sqlite3VdbeJumpHere(v, addrLoop);
    }     
................................................................................
**   2.  Read/write cursors for all indices of pTab must be open as
**       cursor number iIdxCur+i for the i-th index.
**
**   3.  The primary key for the row to be deleted must be stored in a
**       sequence of nPk memory cells starting at iPk.  If nPk==0 that means
**       that a search record formed from OP_MakeRecord is contained in the
**       single memory location iPk.
**
** eMode:
**   Parameter eMode may be passed either ONEPASS_OFF (0), ONEPASS_SINGLE, or
**   ONEPASS_MULTI.  If eMode is not ONEPASS_OFF, then the cursor
**   iDataCur already points to the row to delete. If eMode is ONEPASS_OFF
**   then this function must seek iDataCur to the entry identified by iPk
**   and nPk before reading from it.
**
**   If eMode is ONEPASS_MULTI, then this call is being made as part
**   of a ONEPASS delete that affects multiple rows. In this case, if 
**   iIdxNoSeek is a valid cursor number (>=0), then its position should
**   be preserved following the delete operation. Or, if iIdxNoSeek is not
**   a valid cursor number, the position of iDataCur should be preserved
**   instead.
**
** iIdxNoSeek:
**   If iIdxNoSeek is a valid cursor number (>=0), then it identifies an
**   index cursor (from within array of cursors starting at iIdxCur) that
**   already points to the index entry to be deleted.
*/
void sqlite3GenerateRowDelete(
  Parse *pParse,     /* Parsing context */
  Table *pTab,       /* Table containing the row to be deleted */
  Trigger *pTrigger, /* List of triggers to (potentially) fire */
  int iDataCur,      /* Cursor from which column data is extracted */
  int iIdxCur,       /* First index cursor */
  int iPk,           /* First memory cell containing the PRIMARY KEY */
  i16 nPk,           /* Number of PRIMARY KEY memory cells */
  u8 count,          /* If non-zero, increment the row change counter */
  u8 onconf,         /* Default ON CONFLICT policy for triggers */
  u8 eMode,          /* ONEPASS_OFF, _SINGLE, or _MULTI.  See above */
  int iIdxNoSeek     /* Cursor number of cursor that does not need seeking */
){
  Vdbe *v = pParse->pVdbe;        /* Vdbe */
  int iOld = 0;                   /* First register in OLD.* array */
  int iLabel;                     /* Label resolved to end of generated code */
  u8 opSeek;                      /* Seek opcode */

  /* Vdbe is guaranteed to have been allocated by this stage. */
................................................................................
                         iDataCur, iIdxCur, iPk, (int)nPk));

  /* Seek cursor iCur to the row to delete. If this row no longer exists 
  ** (this can happen if a trigger program has already deleted it), do
  ** not attempt to delete it or fire any DELETE triggers.  */
  iLabel = sqlite3VdbeMakeLabel(v);
  opSeek = HasRowid(pTab) ? OP_NotExists : OP_NotFound;
  if( eMode==ONEPASS_OFF ){
    sqlite3VdbeAddOp4Int(v, opSeek, iDataCur, iLabel, iPk, nPk);
    VdbeCoverageIf(v, opSeek==OP_NotExists);
    VdbeCoverageIf(v, opSeek==OP_NotFound);
  }
 
  /* If there are any triggers to fire, allocate a range of registers to
  ** use for the old.* references in the triggers.  */
................................................................................
    sqlite3FkCheck(pParse, pTab, iOld, 0, 0, 0);
  }

  /* Delete the index and table entries. Skip this step if pTab is really
  ** a view (in which case the only effect of the DELETE statement is to
  ** fire the INSTEAD OF triggers).  */ 
  if( pTab->pSelect==0 ){
    sqlite3GenerateRowIndexDelete(pParse, pTab, iDataCur, iIdxCur,0,iIdxNoSeek);
    sqlite3VdbeAddOp2(v, OP_Delete, iDataCur, (count?OPFLAG_NCHANGE:0));
    if( count ){
      sqlite3VdbeChangeP4(v, -1, pTab->zName, P4_TRANSIENT);
    }
    if( iIdxNoSeek>=0 ){
      sqlite3VdbeAddOp1(v, OP_Delete, iIdxNoSeek);
    }
    sqlite3VdbeChangeP5(v, eMode==ONEPASS_MULTI);
  }

  /* Do any ON CASCADE, SET NULL or SET DEFAULT operations required to
  ** handle rows (possibly in other tables) that refer via a foreign key
  ** to the row just deleted. */ 
  sqlite3FkActions(pParse, pTab, 0, iOld, 0, 0);

................................................................................
**       that is to be deleted.
*/
void sqlite3GenerateRowIndexDelete(
  Parse *pParse,     /* Parsing and code generating context */
  Table *pTab,       /* Table containing the row to be deleted */
  int iDataCur,      /* Cursor of table holding data. */
  int iIdxCur,       /* First index cursor */
  int *aRegIdx,      /* Only delete if aRegIdx!=0 && aRegIdx[i]>0 */
  int iIdxNoSeek     /* Do not delete from this cursor */
){
  int i;             /* Index loop counter */
  int r1 = -1;       /* Register holding an index key */
  int iPartIdxLabel; /* Jump destination for skipping partial index entries */
  Index *pIdx;       /* Current index */
  Index *pPrior = 0; /* Prior index */
  Vdbe *v;           /* The prepared statement under construction */
................................................................................

  v = pParse->pVdbe;
  pPk = HasRowid(pTab) ? 0 : sqlite3PrimaryKeyIndex(pTab);
  for(i=0, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
    assert( iIdxCur+i!=iDataCur || pPk==pIdx );
    if( aRegIdx!=0 && aRegIdx[i]==0 ) continue;
    if( pIdx==pPk ) continue;
    if( iIdxCur+i==iIdxNoSeek ) continue;
    VdbeModuleComment((v, "GenRowIdxDel for %s", pIdx->zName));
    r1 = sqlite3GenerateIndexKey(pParse, pIdx, iDataCur, 0, 1,
        &iPartIdxLabel, pPrior, r1);
    sqlite3VdbeAddOp3(v, OP_IdxDelete, iIdxCur+i, r1,
        pIdx->uniqNotNull ? pIdx->nKeyCol : pIdx->nColumn);
    sqlite3ResolvePartIdxLabel(pParse, iPartIdxLabel);
    pPrior = pIdx;
  }
}

/*
** Generate code that will assemble an index key and stores it in register

        Trigger *pTrigger = 0;
        if( db->flags&SQLITE_RecTriggers ){
          pTrigger = sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0, 0);
        }
        if( pTrigger || sqlite3FkRequired(pParse, pTab, 0, 0) ){
          sqlite3MultiWrite(pParse);
          sqlite3GenerateRowDelete(pParse, pTab, pTrigger, iDataCur, iIdxCur,
                                   regNewData, 1, 0, OE_Replace, 1);


        }else if( pTab->pIndex ){
          sqlite3MultiWrite(pParse);
          sqlite3GenerateRowIndexDelete(pParse, pTab, iDataCur, iIdxCur, 0);

        }
        seenReplace = 1;
        break;
      }
      case OE_Ignore: {
        /*assert( seenReplace==0 );*/
        sqlite3VdbeGoto(v, ignoreDest);
................................................................................
        Trigger *pTrigger = 0;
        assert( onError==OE_Replace );
        sqlite3MultiWrite(pParse);
        if( db->flags&SQLITE_RecTriggers ){
          pTrigger = sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0, 0);
        }
        sqlite3GenerateRowDelete(pParse, pTab, pTrigger, iDataCur, iIdxCur,
                                 regR, nPkField, 0, OE_Replace, pIdx==pPk);

        seenReplace = 1;
        break;
      }
    }
    sqlite3VdbeResolveLabel(v, addrUniqueOk);
    sqlite3ReleaseTempRange(pParse, regIdx, pIdx->nColumn);
    if( regR!=regIdx ) sqlite3ReleaseTempRange(pParse, regR, nPkField);

        Trigger *pTrigger = 0;
        if( db->flags&SQLITE_RecTriggers ){
          pTrigger = sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0, 0);
        }
        if( pTrigger || sqlite3FkRequired(pParse, pTab, 0, 0) ){
          sqlite3MultiWrite(pParse);
          sqlite3GenerateRowDelete(pParse, pTab, pTrigger, iDataCur, iIdxCur,
                                   regNewData, 1, 0, OE_Replace,
                                   ONEPASS_SINGLE, -1);
        }else{
          if( pTab->pIndex ){
            sqlite3MultiWrite(pParse);
            sqlite3GenerateRowIndexDelete(pParse, pTab, iDataCur, iIdxCur,0,-1);
          }
        }
        seenReplace = 1;
        break;
      }
      case OE_Ignore: {
        /*assert( seenReplace==0 );*/
        sqlite3VdbeGoto(v, ignoreDest);
................................................................................
        Trigger *pTrigger = 0;
        assert( onError==OE_Replace );
        sqlite3MultiWrite(pParse);
        if( db->flags&SQLITE_RecTriggers ){
          pTrigger = sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0, 0);
        }
        sqlite3GenerateRowDelete(pParse, pTab, pTrigger, iDataCur, iIdxCur,
            regR, nPkField, 0, OE_Replace,
            (pIdx==pPk ? ONEPASS_SINGLE : ONEPASS_OFF), -1);
        seenReplace = 1;
        break;
      }
    }
    sqlite3VdbeResolveLabel(v, addrUniqueOk);
    sqlite3ReleaseTempRange(pParse, regIdx, pIdx->nColumn);
    if( regR!=regIdx ) sqlite3ReleaseTempRange(pParse, regR, nPkField);

  sqlite3_result_blob64,
  sqlite3_result_text64,
  sqlite3_strglob,
  /* Version 3.8.11 and later */
  (sqlite3_value*(*)(const sqlite3_value*))sqlite3_value_dup,
  sqlite3_value_free,
  sqlite3_result_zeroblob64,
  sqlite3_bind_zeroblob64



};

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

  sqlite3_result_blob64,
  sqlite3_result_text64,
  sqlite3_strglob,
  /* Version 3.8.11 and later */
  (sqlite3_value*(*)(const sqlite3_value*))sqlite3_value_dup,
  sqlite3_value_free,
  sqlite3_result_zeroblob64,
  sqlite3_bind_zeroblob64,
  /* Version 3.8.12 and later */
  sqlite3_value_subtype,
  sqlite3_result_subtype
};

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

} ScratchFreeslot;

/*
** State information local to the memory allocation subsystem.
*/
static SQLITE_WSD struct Mem0Global {
  sqlite3_mutex *mutex;         /* Mutex to serialize access */
  sqlite3_int64 alarmThreshold;  /* The soft heap limit */

  /*
  ** Pointers to the end of sqlite3GlobalConfig.pScratch memory
  ** (so that a range test can be used to determine if an allocation
  ** being freed came from pScratch) and a pointer to the list of
  ** unused scratch allocations.
  */
................................................................................
/*
** Return the memory allocator mutex. sqlite3_status() needs it.
*/
sqlite3_mutex *sqlite3MallocMutex(void){
  return mem0.mutex;
}

/*
** Return the amount of memory currently in use.
*/
static sqlite3_int64 memInUse(void){
  assert( sqlite3_mutex_held(mem0.mutex) );
  return sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED);
}

/*
** Called when the soft heap limit is exceeded for an allocation
** of nBytes.
*/
#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
static void sqlite3HeapLimitExceeded(int nByte){
  sqlite3_int64 excess = memInUse() + nByte - mem0.alarmThreshold;
  sqlite3_mutex_leave(mem0.mutex);
  sqlite3_release_memory((int)(excess & 0x7fffffff));
  sqlite3_mutex_enter(mem0.mutex);
}
#else
# define sqlite3HeapLimitExceeded(X)  /* no-op */
#endif

/*
** Check to see if increasing the total memory usage by nNew bytes
** will exceed the soft heap limit.  
**
** If the soft heap limit is exceeded, set the mem0.nearlyFull flag
** and invoke sqlite3HeapLimitExceeded() to try to free up some
** memory.
*/
static void sqlite3CheckSoftHeapLimit(int nNew){
  assert( sqlite3_mutex_held(mem0.mutex) );
  if( mem0.alarmThreshold>0 ){
    if( mem0.alarmThreshold-nNew >= memInUse() ){
      mem0.nearlyFull = 1;
      sqlite3HeapLimitExceeded(nNew);
    }else{
      mem0.nearlyFull = 0;
    }
  }
}

#ifndef SQLITE_OMIT_DEPRECATED
/*
** Deprecated external interface.  First deprecated 2007-11-05.  Changed
** into a no-op on 2015-09-02.


*/
int sqlite3_memory_alarm(
  void(*xCallback)(void *pArg, sqlite3_int64 used,int N),
  void *pArg,
  sqlite3_int64 iThreshold
){



  return SQLITE_OK;
}
#endif

/*
** Set the soft heap-size limit for the library. Passing a zero or 
** negative value indicates no limit.
*/
sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 n){
  sqlite3_int64 priorLimit;


#ifndef SQLITE_OMIT_AUTOINIT
  int rc = sqlite3_initialize();
  if( rc ) return -1;
#endif
  sqlite3_mutex_enter(mem0.mutex);
  priorLimit = mem0.alarmThreshold;
  if( n>0 ){
    mem0.alarmThreshold = n;
    sqlite3CheckSoftHeapLimit(0);
  }else if( n==0 ){

    mem0.alarmThreshold = 0;

    mem0.nearlyFull = 0;
  }
  sqlite3_mutex_leave(mem0.mutex);


  return priorLimit;
}
void sqlite3_soft_heap_limit(int n){
  if( n<0 ) n = 0;
  sqlite3_soft_heap_limit64(n);
}

................................................................................
** or since the most recent reset.
*/
sqlite3_int64 sqlite3_memory_highwater(int resetFlag){
  sqlite3_int64 res, mx;
  sqlite3_status64(SQLITE_STATUS_MEMORY_USED, &res, &mx, resetFlag);
  return mx;
}











/*
** Do a memory allocation with statistics and alarms.  Assume the
** lock is already held.
*/
static int mallocWithAlarm(int n, void **pp){
  int nFull;
  void *p;
  assert( sqlite3_mutex_held(mem0.mutex) );
  nFull = sqlite3GlobalConfig.m.xRoundup(n);
  sqlite3StatusSet(SQLITE_STATUS_MALLOC_SIZE, n);
  sqlite3CheckSoftHeapLimit(nFull);








  p = sqlite3GlobalConfig.m.xMalloc(nFull);
#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
  if( p==0 && mem0.alarmThreshold ){
    sqlite3HeapLimitExceeded(nFull);

    p = sqlite3GlobalConfig.m.xMalloc(nFull);
  }
#endif
  if( p ){
    nFull = sqlite3MallocSize(p);
    sqlite3StatusUp(SQLITE_STATUS_MEMORY_USED, nFull);
    sqlite3StatusUp(SQLITE_STATUS_MALLOC_COUNT, 1);
................................................................................
  nNew = sqlite3GlobalConfig.m.xRoundup((int)nBytes);
  if( nOld==nNew ){
    pNew = pOld;
  }else if( sqlite3GlobalConfig.bMemstat ){
    sqlite3_mutex_enter(mem0.mutex);
    sqlite3StatusSet(SQLITE_STATUS_MALLOC_SIZE, (int)nBytes);
    nDiff = nNew - nOld;
    sqlite3CheckSoftHeapLimit(nDiff);



    pNew = sqlite3GlobalConfig.m.xRealloc(pOld, nNew);
#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
    if( pNew==0 && mem0.alarmThreshold ){
      sqlite3HeapLimitExceeded((int)nBytes);
      pNew = sqlite3GlobalConfig.m.xRealloc(pOld, nNew);
    }
#endif
    if( pNew ){
      nNew = sqlite3MallocSize(pNew);
      sqlite3StatusUp(SQLITE_STATUS_MEMORY_USED, nNew-nOld);
    }
    sqlite3_mutex_leave(mem0.mutex);
  }else{
    pNew = sqlite3GlobalConfig.m.xRealloc(pOld, nNew);

} ScratchFreeslot;

/*
** State information local to the memory allocation subsystem.
*/
static SQLITE_WSD struct Mem0Global {
  sqlite3_mutex *mutex;         /* Mutex to serialize access */
  sqlite3_int64 alarmThreshold; /* The soft heap limit */

  /*
  ** Pointers to the end of sqlite3GlobalConfig.pScratch memory
  ** (so that a range test can be used to determine if an allocation
  ** being freed came from pScratch) and a pointer to the list of
  ** unused scratch allocations.
  */
................................................................................
/*
** Return the memory allocator mutex. sqlite3_status() needs it.
*/
sqlite3_mutex *sqlite3MallocMutex(void){
  return mem0.mutex;
}












































#ifndef SQLITE_OMIT_DEPRECATED
/*
** Deprecated external interface.  It used to set an alarm callback

** that was invoked when memory usage grew too large.  Now it is a
** no-op.
*/
int sqlite3_memory_alarm(
  void(*xCallback)(void *pArg, sqlite3_int64 used,int N),
  void *pArg,
  sqlite3_int64 iThreshold
){
  (void)xCallback;
  (void)pArg;
  (void)iThreshold;
  return SQLITE_OK;
}
#endif

/*
** Set the soft heap-size limit for the library. Passing a zero or 
** negative value indicates no limit.
*/
sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 n){
  sqlite3_int64 priorLimit;
  sqlite3_int64 excess;
  sqlite3_int64 nUsed;
#ifndef SQLITE_OMIT_AUTOINIT
  int rc = sqlite3_initialize();
  if( rc ) return -1;
#endif
  sqlite3_mutex_enter(mem0.mutex);
  priorLimit = mem0.alarmThreshold;
  if( n<0 ){
    sqlite3_mutex_leave(mem0.mutex);
    return priorLimit;

  }
  mem0.alarmThreshold = n;
  nUsed = sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED);
  mem0.nearlyFull = (n>0 && n<=nUsed);

  sqlite3_mutex_leave(mem0.mutex);
  excess = sqlite3_memory_used() - n;
  if( excess>0 ) sqlite3_release_memory((int)(excess & 0x7fffffff));
  return priorLimit;
}
void sqlite3_soft_heap_limit(int n){
  if( n<0 ) n = 0;
  sqlite3_soft_heap_limit64(n);
}

................................................................................
** or since the most recent reset.
*/
sqlite3_int64 sqlite3_memory_highwater(int resetFlag){
  sqlite3_int64 res, mx;
  sqlite3_status64(SQLITE_STATUS_MEMORY_USED, &res, &mx, resetFlag);
  return mx;
}

/*
** Trigger the alarm 
*/
static void sqlite3MallocAlarm(int nByte){
  if( mem0.alarmThreshold<=0 ) return;
  sqlite3_mutex_leave(mem0.mutex);
  sqlite3_release_memory(nByte);
  sqlite3_mutex_enter(mem0.mutex);
}

/*
** Do a memory allocation with statistics and alarms.  Assume the
** lock is already held.
*/
static int mallocWithAlarm(int n, void **pp){
  int nFull;
  void *p;
  assert( sqlite3_mutex_held(mem0.mutex) );
  nFull = sqlite3GlobalConfig.m.xRoundup(n);
  sqlite3StatusSet(SQLITE_STATUS_MALLOC_SIZE, n);
  if( mem0.alarmThreshold>0 ){
    sqlite3_int64 nUsed = sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED);
    if( nUsed >= mem0.alarmThreshold - nFull ){
      mem0.nearlyFull = 1;
      sqlite3MallocAlarm(nFull);
    }else{
      mem0.nearlyFull = 0;
    }
  }
  p = sqlite3GlobalConfig.m.xMalloc(nFull);
#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
  if( p==0 && mem0.alarmThreshold>0 ){

    sqlite3MallocAlarm(nFull);
    p = sqlite3GlobalConfig.m.xMalloc(nFull);
  }
#endif
  if( p ){
    nFull = sqlite3MallocSize(p);
    sqlite3StatusUp(SQLITE_STATUS_MEMORY_USED, nFull);
    sqlite3StatusUp(SQLITE_STATUS_MALLOC_COUNT, 1);
................................................................................
  nNew = sqlite3GlobalConfig.m.xRoundup((int)nBytes);
  if( nOld==nNew ){
    pNew = pOld;
  }else if( sqlite3GlobalConfig.bMemstat ){
    sqlite3_mutex_enter(mem0.mutex);
    sqlite3StatusSet(SQLITE_STATUS_MALLOC_SIZE, (int)nBytes);
    nDiff = nNew - nOld;
    if( sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED) >= 
          mem0.alarmThreshold-nDiff ){
      sqlite3MallocAlarm(nDiff);
    }
    pNew = sqlite3GlobalConfig.m.xRealloc(pOld, nNew);

    if( pNew==0 && mem0.alarmThreshold>0 ){
      sqlite3MallocAlarm((int)nBytes);
      pNew = sqlite3GlobalConfig.m.xRealloc(pOld, nNew);
    }

    if( pNew ){
      nNew = sqlite3MallocSize(pNew);
      sqlite3StatusUp(SQLITE_STATUS_MEMORY_USED, nNew-nOld);
    }
    sqlite3_mutex_leave(mem0.mutex);
  }else{
    pNew = sqlite3GlobalConfig.m.xRealloc(pOld, nNew);

#if defined(SQLITE_DEBUG) && !defined(SQLITE_MUTEX_OMIT)
/*
** For debugging purposes, record when the mutex subsystem is initialized
** and uninitialized so that we can assert() if there is an attempt to
** allocate a mutex while the system is uninitialized.
*/
static SQLITE_WSD int mutexIsInit = 0;
#endif /* SQLITE_DEBUG */


#ifndef SQLITE_MUTEX_OMIT
/*
** Initialize the mutex system.
*/
int sqlite3MutexInit(void){ 
................................................................................
    pTo->xMutexTry = pFrom->xMutexTry;
    pTo->xMutexLeave = pFrom->xMutexLeave;
    pTo->xMutexHeld = pFrom->xMutexHeld;
    pTo->xMutexNotheld = pFrom->xMutexNotheld;
    sqlite3MemoryBarrier();
    pTo->xMutexAlloc = pFrom->xMutexAlloc;
  }

  rc = sqlite3GlobalConfig.mutex.xMutexInit();

#ifdef SQLITE_DEBUG
  GLOBAL(int, mutexIsInit) = 1;
#endif

  return rc;
................................................................................
** Retrieve a pointer to a static mutex or allocate a new dynamic one.
*/
sqlite3_mutex *sqlite3_mutex_alloc(int id){
#ifndef SQLITE_OMIT_AUTOINIT
  if( id<=SQLITE_MUTEX_RECURSIVE && sqlite3_initialize() ) return 0;
  if( id>SQLITE_MUTEX_RECURSIVE && sqlite3MutexInit() ) return 0;
#endif

  return sqlite3GlobalConfig.mutex.xMutexAlloc(id);
}

sqlite3_mutex *sqlite3MutexAlloc(int id){
  if( !sqlite3GlobalConfig.bCoreMutex ){
    return 0;
  }
  assert( GLOBAL(int, mutexIsInit) );

  return sqlite3GlobalConfig.mutex.xMutexAlloc(id);
}

/*
** Free a dynamic mutex.
*/
void sqlite3_mutex_free(sqlite3_mutex *p){
  if( p ){

    sqlite3GlobalConfig.mutex.xMutexFree(p);
  }
}

/*
** Obtain the mutex p. If some other thread already has the mutex, block
** until it can be obtained.
*/
void sqlite3_mutex_enter(sqlite3_mutex *p){
  if( p ){

    sqlite3GlobalConfig.mutex.xMutexEnter(p);
  }
}

/*
** Obtain the mutex p. If successful, return SQLITE_OK. Otherwise, if another
** thread holds the mutex and it cannot be obtained, return SQLITE_BUSY.
*/
int sqlite3_mutex_try(sqlite3_mutex *p){
  int rc = SQLITE_OK;
  if( p ){

    return sqlite3GlobalConfig.mutex.xMutexTry(p);
  }
  return rc;
}

/*
** The sqlite3_mutex_leave() routine exits a mutex that was previously
** entered by the same thread.  The behavior is undefined if the mutex 
** is not currently entered. If a NULL pointer is passed as an argument
** this function is a no-op.
*/
void sqlite3_mutex_leave(sqlite3_mutex *p){
  if( p ){

    sqlite3GlobalConfig.mutex.xMutexLeave(p);
  }
}

#ifndef NDEBUG
/*
** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routine are
** intended for use inside assert() statements.
*/
int sqlite3_mutex_held(sqlite3_mutex *p){

  return p==0 || sqlite3GlobalConfig.mutex.xMutexHeld(p);
}
int sqlite3_mutex_notheld(sqlite3_mutex *p){

  return p==0 || sqlite3GlobalConfig.mutex.xMutexNotheld(p);
}
#endif

#endif /* !defined(SQLITE_MUTEX_OMIT) */

#if defined(SQLITE_DEBUG) && !defined(SQLITE_MUTEX_OMIT)
/*
** For debugging purposes, record when the mutex subsystem is initialized
** and uninitialized so that we can assert() if there is an attempt to
** allocate a mutex while the system is uninitialized.
*/
static SQLITE_WSD int mutexIsInit = 0;
#endif /* SQLITE_DEBUG && !defined(SQLITE_MUTEX_OMIT) */


#ifndef SQLITE_MUTEX_OMIT
/*
** Initialize the mutex system.
*/
int sqlite3MutexInit(void){ 
................................................................................
    pTo->xMutexTry = pFrom->xMutexTry;
    pTo->xMutexLeave = pFrom->xMutexLeave;
    pTo->xMutexHeld = pFrom->xMutexHeld;
    pTo->xMutexNotheld = pFrom->xMutexNotheld;
    sqlite3MemoryBarrier();
    pTo->xMutexAlloc = pFrom->xMutexAlloc;
  }
  assert( sqlite3GlobalConfig.mutex.xMutexInit );
  rc = sqlite3GlobalConfig.mutex.xMutexInit();

#ifdef SQLITE_DEBUG
  GLOBAL(int, mutexIsInit) = 1;
#endif

  return rc;
................................................................................
** Retrieve a pointer to a static mutex or allocate a new dynamic one.
*/
sqlite3_mutex *sqlite3_mutex_alloc(int id){
#ifndef SQLITE_OMIT_AUTOINIT
  if( id<=SQLITE_MUTEX_RECURSIVE && sqlite3_initialize() ) return 0;
  if( id>SQLITE_MUTEX_RECURSIVE && sqlite3MutexInit() ) return 0;
#endif
  assert( sqlite3GlobalConfig.mutex.xMutexAlloc );
  return sqlite3GlobalConfig.mutex.xMutexAlloc(id);
}

sqlite3_mutex *sqlite3MutexAlloc(int id){
  if( !sqlite3GlobalConfig.bCoreMutex ){
    return 0;
  }
  assert( GLOBAL(int, mutexIsInit) );
  assert( sqlite3GlobalConfig.mutex.xMutexAlloc );
  return sqlite3GlobalConfig.mutex.xMutexAlloc(id);
}

/*
** Free a dynamic mutex.
*/
void sqlite3_mutex_free(sqlite3_mutex *p){
  if( p ){
    assert( sqlite3GlobalConfig.mutex.xMutexFree );
    sqlite3GlobalConfig.mutex.xMutexFree(p);
  }
}

/*
** Obtain the mutex p. If some other thread already has the mutex, block
** until it can be obtained.
*/
void sqlite3_mutex_enter(sqlite3_mutex *p){
  if( p ){
    assert( sqlite3GlobalConfig.mutex.xMutexEnter );
    sqlite3GlobalConfig.mutex.xMutexEnter(p);
  }
}

/*
** Obtain the mutex p. If successful, return SQLITE_OK. Otherwise, if another
** thread holds the mutex and it cannot be obtained, return SQLITE_BUSY.
*/
int sqlite3_mutex_try(sqlite3_mutex *p){
  int rc = SQLITE_OK;
  if( p ){
    assert( sqlite3GlobalConfig.mutex.xMutexTry );
    return sqlite3GlobalConfig.mutex.xMutexTry(p);
  }
  return rc;
}

/*
** The sqlite3_mutex_leave() routine exits a mutex that was previously
** entered by the same thread.  The behavior is undefined if the mutex 
** is not currently entered. If a NULL pointer is passed as an argument
** this function is a no-op.
*/
void sqlite3_mutex_leave(sqlite3_mutex *p){
  if( p ){
    assert( sqlite3GlobalConfig.mutex.xMutexLeave );
    sqlite3GlobalConfig.mutex.xMutexLeave(p);
  }
}

#ifndef NDEBUG
/*
** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routine are
** intended for use inside assert() statements.
*/
int sqlite3_mutex_held(sqlite3_mutex *p){
  assert( p==0 || sqlite3GlobalConfig.mutex.xMutexHeld );
  return p==0 || sqlite3GlobalConfig.mutex.xMutexHeld(p);
}
int sqlite3_mutex_notheld(sqlite3_mutex *p){
  assert( p==0 || sqlite3GlobalConfig.mutex.xMutexNotheld );
  return p==0 || sqlite3GlobalConfig.mutex.xMutexNotheld(p);
}
#endif

#endif /* !defined(SQLITE_MUTEX_OMIT) */

#define sqlite3_mutex_try(X)      SQLITE_OK
#define sqlite3_mutex_leave(X)    
#define sqlite3_mutex_held(X)     ((void)(X),1)
#define sqlite3_mutex_notheld(X)  ((void)(X),1)
#define sqlite3MutexAlloc(X)      ((sqlite3_mutex*)8)
#define sqlite3MutexInit()        SQLITE_OK
#define sqlite3MutexEnd()
#define sqlite3MemoryBarrier()    
#define MUTEX_LOGIC(X)
#else
#define MUTEX_LOGIC(X)            X
#endif /* defined(SQLITE_MUTEX_OMIT) */

#define sqlite3_mutex_try(X)      SQLITE_OK
#define sqlite3_mutex_leave(X)    
#define sqlite3_mutex_held(X)     ((void)(X),1)
#define sqlite3_mutex_notheld(X)  ((void)(X),1)
#define sqlite3MutexAlloc(X)      ((sqlite3_mutex*)8)
#define sqlite3MutexInit()        SQLITE_OK
#define sqlite3MutexEnd()

#define MUTEX_LOGIC(X)
#else
#define MUTEX_LOGIC(X)            X
#endif /* defined(SQLITE_MUTEX_OMIT) */

/*
** Try to provide a memory barrier operation, needed for initialization only.
*/
void sqlite3MemoryBarrier(void){
#if defined(SQLITE_MEMORY_BARRIER)
  SQLITE_MEMORY_BARRIER;
#elif defined(__GNUC__)
  __sync_synchronize();
#endif
}

/*
** Initialize and deinitialize the mutex subsystem.
*/

/*
** Try to provide a memory barrier operation, needed for initialization only.
*/
void sqlite3MemoryBarrier(void){
#if defined(SQLITE_MEMORY_BARRIER)
  SQLITE_MEMORY_BARRIER;
#elif defined(__GNUC__) && GCC_VERSION>=4001000
  __sync_synchronize();
#endif
}

/*
** Initialize and deinitialize the mutex subsystem.
*/

  int nFree = 0;
  assert( sqlite3_mutex_notheld(pcache1.grp.mutex) );
  assert( sqlite3_mutex_notheld(pcache1.mutex) );
  if( sqlite3GlobalConfig.nPage==0 ){
    PgHdr1 *p;
    pcache1EnterMutex(&pcache1.grp);
    while( (nReq<0 || nFree<nReq)
       &&  (p=pcache1.grp.lru.pLruPrev)->isAnchor==0

    ){
      nFree += pcache1MemSize(p->page.pBuf);
#ifdef SQLITE_PCACHE_SEPARATE_HEADER
      nFree += sqlite3MemSize(p);
#endif
      assert( p->isPinned==0 );
      pcache1PinPage(p);
................................................................................
  int *pnCurrent,      /* OUT: Total number of pages cached */
  int *pnMax,          /* OUT: Global maximum cache size */
  int *pnMin,          /* OUT: Sum of PCache1.nMin for purgeable caches */
  int *pnRecyclable    /* OUT: Total number of pages available for recycling */
){
  PgHdr1 *p;
  int nRecyclable = 0;
  for(p=pcache1.grp.lru.pLruNext; !p->isAnchor; p=p->pLruNext){
    assert( p->isPinned==0 );
    nRecyclable++;
  }
  *pnCurrent = pcache1.grp.nCurrentPage;
  *pnMax = (int)pcache1.grp.nMaxPage;
  *pnMin = (int)pcache1.grp.nMinPage;
  *pnRecyclable = nRecyclable;
}
#endif

  int nFree = 0;
  assert( sqlite3_mutex_notheld(pcache1.grp.mutex) );
  assert( sqlite3_mutex_notheld(pcache1.mutex) );
  if( sqlite3GlobalConfig.nPage==0 ){
    PgHdr1 *p;
    pcache1EnterMutex(&pcache1.grp);
    while( (nReq<0 || nFree<nReq)
       &&  (p=pcache1.grp.lru.pLruPrev)!=0
       &&  p->isAnchor==0
    ){
      nFree += pcache1MemSize(p->page.pBuf);
#ifdef SQLITE_PCACHE_SEPARATE_HEADER
      nFree += sqlite3MemSize(p);
#endif
      assert( p->isPinned==0 );
      pcache1PinPage(p);
................................................................................
  int *pnCurrent,      /* OUT: Total number of pages cached */
  int *pnMax,          /* OUT: Global maximum cache size */
  int *pnMin,          /* OUT: Sum of PCache1.nMin for purgeable caches */
  int *pnRecyclable    /* OUT: Total number of pages available for recycling */
){
  PgHdr1 *p;
  int nRecyclable = 0;
  for(p=pcache1.grp.lru.pLruNext; p && !p->isAnchor; p=p->pLruNext){
    assert( p->isPinned==0 );
    nRecyclable++;
  }
  *pnCurrent = pcache1.grp.nCurrentPage;
  *pnMax = (int)pcache1.grp.nMaxPage;
  *pnMin = (int)pcache1.grp.nMinPage;
  *pnRecyclable = nRecyclable;
}
#endif

** KEYWORDS: sqlite3_version, sqlite3_sourceid
**
** These interfaces provide the same information as the [SQLITE_VERSION],
** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
** but are associated with the library instead of the header file.  ^(Cautious
** programmers might include assert() statements in their application to
** verify that values returned by these interfaces match the macros in
** the header, and thus insure that the application is
** compiled with matching library and header files.
**
** <blockquote><pre>
** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 );
** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
** </pre></blockquote>)^
................................................................................
** to an empty string, or a pointer that contains only whitespace and/or 
** SQL comments, then no SQL statements are evaluated and the database
** is not changed.
**
** Restrictions:
**
** <ul>
** <li> The application must insure that the 1st parameter to sqlite3_exec()
**      is a valid and open [database connection].
** <li> The application must not close the [database connection] specified by
**      the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
** <li> The application must not modify the SQL statement text passed into
**      the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
** </ul>
*/
................................................................................
**
** The sqlite3_config() interface is used to make global configuration
** changes to SQLite in order to tune SQLite to the specific needs of
** the application.  The default configuration is recommended for most
** applications and so this routine is usually not necessary.  It is
** provided to support rare applications with unusual needs.
**
** The sqlite3_config() interface is not threadsafe.  The application
** must insure that no other SQLite interfaces are invoked by other
** threads while sqlite3_config() is running.  Furthermore, sqlite3_config()


** may only be invoked prior to library initialization using
** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
** [sqlite3_shutdown()] then it will return SQLITE_MISUSE.
** Note, however, that ^sqlite3_config() can be called as part of the
** implementation of an application-defined [sqlite3_os_init()].
**
................................................................................
const unsigned char *sqlite3_value_text(sqlite3_value*);
const void *sqlite3_value_text16(sqlite3_value*);
const void *sqlite3_value_text16le(sqlite3_value*);
const void *sqlite3_value_text16be(sqlite3_value*);
int sqlite3_value_type(sqlite3_value*);
int sqlite3_value_numeric_type(sqlite3_value*);

















/*
** CAPI3REF: Copy And Free SQL Values
** METHOD: sqlite3_value
**
** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value]
** object D and returns a pointer to that copy.  ^The [sqlite3_value] returned
** is a [protected sqlite3_value] object even if the input is not.
................................................................................
void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
void sqlite3_result_zeroblob(sqlite3_context*, int n);
int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n);
















/*
** CAPI3REF: Define New Collating Sequences
** METHOD: sqlite3
**
** ^These functions add, remove, or modify a [collation] associated
** with the [database connection] specified as the first argument.
**
................................................................................
** <li>  SQLITE_MUTEX_STATIC_OPEN
** <li>  SQLITE_MUTEX_STATIC_PRNG
** <li>  SQLITE_MUTEX_STATIC_LRU
** <li>  SQLITE_MUTEX_STATIC_PMEM
** <li>  SQLITE_MUTEX_STATIC_APP1
** <li>  SQLITE_MUTEX_STATIC_APP2
** <li>  SQLITE_MUTEX_STATIC_APP3



** </ul>
**
** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
** cause sqlite3_mutex_alloc() to create
** a new mutex.  ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
** The mutex implementation does not need to make a distinction

** KEYWORDS: sqlite3_version, sqlite3_sourceid
**
** These interfaces provide the same information as the [SQLITE_VERSION],
** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
** but are associated with the library instead of the header file.  ^(Cautious
** programmers might include assert() statements in their application to
** verify that values returned by these interfaces match the macros in
** the header, and thus ensure that the application is
** compiled with matching library and header files.
**
** <blockquote><pre>
** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 );
** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
** </pre></blockquote>)^
................................................................................
** to an empty string, or a pointer that contains only whitespace and/or 
** SQL comments, then no SQL statements are evaluated and the database
** is not changed.
**
** Restrictions:
**
** <ul>
** <li> The application must ensure that the 1st parameter to sqlite3_exec()
**      is a valid and open [database connection].
** <li> The application must not close the [database connection] specified by
**      the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
** <li> The application must not modify the SQL statement text passed into
**      the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
** </ul>
*/
................................................................................
**
** The sqlite3_config() interface is used to make global configuration
** changes to SQLite in order to tune SQLite to the specific needs of
** the application.  The default configuration is recommended for most
** applications and so this routine is usually not necessary.  It is
** provided to support rare applications with unusual needs.
**
** <b>The sqlite3_config() interface is not threadsafe. The application
** must ensure that no other SQLite interfaces are invoked by other
** threads while sqlite3_config() is running.</b>
**
** The sqlite3_config() interface
** may only be invoked prior to library initialization using
** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
** [sqlite3_shutdown()] then it will return SQLITE_MISUSE.
** Note, however, that ^sqlite3_config() can be called as part of the
** implementation of an application-defined [sqlite3_os_init()].
**
................................................................................
const unsigned char *sqlite3_value_text(sqlite3_value*);
const void *sqlite3_value_text16(sqlite3_value*);
const void *sqlite3_value_text16le(sqlite3_value*);
const void *sqlite3_value_text16be(sqlite3_value*);
int sqlite3_value_type(sqlite3_value*);
int sqlite3_value_numeric_type(sqlite3_value*);

/*
** CAPI3REF: Obtaining SQL Values
** METHOD: sqlite3_value
**
** The sqlite3_value_subtype(V) function returns the subtype for
** an [application-defined SQL function] argument V.  The subtype
** information can be used to pass a limited amount of context from
** one SQL function to another.  Use the [sqlite3_result_subtype()]
** routine to set the subtype for the return value of an SQL function.
**
** SQLite makes no use of subtype itself.  It merely passes the subtype
** from the result of one [application-defined SQL function] into the
** input of another.
*/
unsigned int sqlite3_value_subtype(sqlite3_value*);

/*
** CAPI3REF: Copy And Free SQL Values
** METHOD: sqlite3_value
**
** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value]
** object D and returns a pointer to that copy.  ^The [sqlite3_value] returned
** is a [protected sqlite3_value] object even if the input is not.
................................................................................
void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
void sqlite3_result_zeroblob(sqlite3_context*, int n);
int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n);


/*
** CAPI3REF: Setting The Subtype Of An SQL Function
** METHOD: sqlite3_context
**
** The sqlite3_result_subtype(C,T) function causes the subtype of
** the result from the [application-defined SQL function] with 
** [sqlite3_context] C to be the value T.  Only the lower 8 bits 
** of the subtype T are preserved in current versions of SQLite;
** higher order bits are discarded.
** The number of subtype bytes preserved by SQLite might increase
** in future releases of SQLite.
*/
void sqlite3_result_subtype(sqlite3_context*,unsigned int);

/*
** CAPI3REF: Define New Collating Sequences
** METHOD: sqlite3
**
** ^These functions add, remove, or modify a [collation] associated
** with the [database connection] specified as the first argument.
**
................................................................................
** <li>  SQLITE_MUTEX_STATIC_OPEN
** <li>  SQLITE_MUTEX_STATIC_PRNG
** <li>  SQLITE_MUTEX_STATIC_LRU
** <li>  SQLITE_MUTEX_STATIC_PMEM
** <li>  SQLITE_MUTEX_STATIC_APP1
** <li>  SQLITE_MUTEX_STATIC_APP2
** <li>  SQLITE_MUTEX_STATIC_APP3
** <li>  SQLITE_MUTEX_STATIC_VFS1
** <li>  SQLITE_MUTEX_STATIC_VFS2
** <li>  SQLITE_MUTEX_STATIC_VFS3
** </ul>
**
** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
** cause sqlite3_mutex_alloc() to create
** a new mutex.  ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
** The mutex implementation does not need to make a distinction

                         void(*)(void*), unsigned char);
  int (*strglob)(const char*,const char*);
  /* Version 3.8.11 and later */
  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);



};

/*
** 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
** (part of the main SQLite library - not an extension) so that
** it can get access to the sqlite3_api_routines structure
** definition.  But the main library does not want to redefine
** the API.  So the redefinition macros are only valid if the
** SQLITE_CORE macros is undefined.
*/
#ifndef SQLITE_CORE
#define sqlite3_aggregate_context      sqlite3_api->aggregate_context
#ifndef SQLITE_OMIT_DEPRECATED
#define sqlite3_aggregate_count        sqlite3_api->aggregate_count
#endif
#define sqlite3_bind_blob              sqlite3_api->bind_blob
#define sqlite3_bind_double            sqlite3_api->bind_double
#define sqlite3_bind_int               sqlite3_api->bind_int
................................................................................
#define sqlite3_result_text64          sqlite3_api->result_text64
#define sqlite3_strglob                sqlite3_api->strglob
/* Version 3.8.11 and later */
#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
#endif /* SQLITE_CORE */




#ifndef SQLITE_CORE

  /* 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;
# define SQLITE_EXTENSION_INIT3     \
    extern const sqlite3_api_routines *sqlite3_api;
#else

                         void(*)(void*), unsigned char);
  int (*strglob)(const char*,const char*);
  /* Version 3.8.11 and later */
  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 3.8.12 and later */
  unsigned int (*value_subtype)(sqlite3_value*);
  void (*result_subtype)(sqlite3_context*,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
** (part of the main SQLite library - not an extension) so that
** it can get access to the sqlite3_api_routines structure
** definition.  But the main library does not want to redefine
** the API.  So the redefinition macros are only valid if the
** SQLITE_CORE macros is undefined.
*/
#if !defined(SQLITE_CORE) && !defined(SQLITE_OMIT_LOAD_EXTENSION)
#define sqlite3_aggregate_context      sqlite3_api->aggregate_context
#ifndef SQLITE_OMIT_DEPRECATED
#define sqlite3_aggregate_count        sqlite3_api->aggregate_count
#endif
#define sqlite3_bind_blob              sqlite3_api->bind_blob
#define sqlite3_bind_double            sqlite3_api->bind_double
#define sqlite3_bind_int               sqlite3_api->bind_int
................................................................................
#define sqlite3_result_text64          sqlite3_api->result_text64
#define sqlite3_strglob                sqlite3_api->strglob
/* Version 3.8.11 and later */
#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 3.8.12 and later */
#define sqlite3_value_subtype          sqlite3_api->value_subtype
#define sqlite3_result_subtype         sqlite3_api->result_subtype
#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;
# define SQLITE_EXTENSION_INIT3     \
    extern const sqlite3_api_routines *sqlite3_api;
#else

#define WHERE_ONETABLE_ONLY    0x0040 /* Only code the 1st table in pTabList */
#define WHERE_NO_AUTOINDEX     0x0080 /* Disallow automatic indexes */
#define WHERE_GROUPBY          0x0100 /* pOrderBy is really a GROUP BY */
#define WHERE_DISTINCTBY       0x0200 /* pOrderby is really a DISTINCT clause */
#define WHERE_WANT_DISTINCT    0x0400 /* All output needs to be distinct */
#define WHERE_SORTBYGROUP      0x0800 /* Support sqlite3WhereIsSorted() */
#define WHERE_REOPEN_IDX       0x1000 /* Try to use OP_ReopenIdx */


/* Allowed return values from sqlite3WhereIsDistinct()
*/
#define WHERE_DISTINCT_NOOP      0  /* DISTINCT keyword not used */
#define WHERE_DISTINCT_UNIQUE    1  /* No duplicates */
#define WHERE_DISTINCT_ORDERED   2  /* All duplicates are adjacent */
#define WHERE_DISTINCT_UNORDERED 3  /* Duplicates are scattered */
................................................................................

#ifndef SQLITE_MUTEX_OMIT
  sqlite3_mutex_methods const *sqlite3DefaultMutex(void);
  sqlite3_mutex_methods const *sqlite3NoopMutex(void);
  sqlite3_mutex *sqlite3MutexAlloc(int);
  int sqlite3MutexInit(void);
  int sqlite3MutexEnd(void);


  void sqlite3MemoryBarrier(void);


#endif

sqlite3_int64 sqlite3StatusValue(int);
void sqlite3StatusUp(int, int);
void sqlite3StatusDown(int, int);
void sqlite3StatusSet(int, int);

................................................................................
u64 sqlite3WhereOutputRowCount(WhereInfo*);
int sqlite3WhereIsDistinct(WhereInfo*);
int sqlite3WhereIsOrdered(WhereInfo*);
int sqlite3WhereIsSorted(WhereInfo*);
int sqlite3WhereContinueLabel(WhereInfo*);
int sqlite3WhereBreakLabel(WhereInfo*);
int sqlite3WhereOkOnePass(WhereInfo*, int*);



void sqlite3ExprCodeLoadIndexColumn(Parse*, Index*, int, int, int);
int sqlite3ExprCodeGetColumn(Parse*, Table*, int, int, int, u8);
void sqlite3ExprCodeGetColumnOfTable(Vdbe*, Table*, int, int, int);
void sqlite3ExprCodeMove(Parse*, int, int, int);
void sqlite3ExprCacheStore(Parse*, int, int, int);
void sqlite3ExprCachePush(Parse*);
void sqlite3ExprCachePop(Parse*);
................................................................................
int sqlite3ExprIsConstantNotJoin(Expr*);
int sqlite3ExprIsConstantOrFunction(Expr*, u8);
int sqlite3ExprIsTableConstant(Expr*,int);
int sqlite3ExprIsInteger(Expr*, int*);
int sqlite3ExprCanBeNull(const Expr*);
int sqlite3ExprNeedsNoAffinityChange(const Expr*, char);
int sqlite3IsRowid(const char*);

void sqlite3GenerateRowDelete(Parse*,Table*,Trigger*,int,int,int,i16,u8,u8,u8);
void sqlite3GenerateRowIndexDelete(Parse*, Table*, int, int, int*);
int sqlite3GenerateIndexKey(Parse*, Index*, int, int, int, int*,Index*,int);
void sqlite3ResolvePartIdxLabel(Parse*,int);
void sqlite3GenerateConstraintChecks(Parse*,Table*,int*,int,int,int,int,
                                     u8,u8,int,int*);
void sqlite3CompleteInsertion(Parse*,Table*,int,int,int,int*,int,int,int);
int sqlite3OpenTableAndIndices(Parse*, Table*, int, int, u8*, int*, int*);
void sqlite3BeginWriteOperation(Parse*, int, int);

#define WHERE_ONETABLE_ONLY    0x0040 /* Only code the 1st table in pTabList */
#define WHERE_NO_AUTOINDEX     0x0080 /* Disallow automatic indexes */
#define WHERE_GROUPBY          0x0100 /* pOrderBy is really a GROUP BY */
#define WHERE_DISTINCTBY       0x0200 /* pOrderby is really a DISTINCT clause */
#define WHERE_WANT_DISTINCT    0x0400 /* All output needs to be distinct */
#define WHERE_SORTBYGROUP      0x0800 /* Support sqlite3WhereIsSorted() */
#define WHERE_REOPEN_IDX       0x1000 /* Try to use OP_ReopenIdx */
#define WHERE_ONEPASS_MULTIROW 0x2000 /* ONEPASS is ok with multiple rows */

/* Allowed return values from sqlite3WhereIsDistinct()
*/
#define WHERE_DISTINCT_NOOP      0  /* DISTINCT keyword not used */
#define WHERE_DISTINCT_UNIQUE    1  /* No duplicates */
#define WHERE_DISTINCT_ORDERED   2  /* All duplicates are adjacent */
#define WHERE_DISTINCT_UNORDERED 3  /* Duplicates are scattered */
................................................................................

#ifndef SQLITE_MUTEX_OMIT
  sqlite3_mutex_methods const *sqlite3DefaultMutex(void);
  sqlite3_mutex_methods const *sqlite3NoopMutex(void);
  sqlite3_mutex *sqlite3MutexAlloc(int);
  int sqlite3MutexInit(void);
  int sqlite3MutexEnd(void);
#endif
#if !defined(SQLITE_MUTEX_OMIT) && !defined(SQLITE_MUTEX_NOOP)
  void sqlite3MemoryBarrier(void);
#else
# define sqlite3MemoryBarrier()
#endif

sqlite3_int64 sqlite3StatusValue(int);
void sqlite3StatusUp(int, int);
void sqlite3StatusDown(int, int);
void sqlite3StatusSet(int, int);

................................................................................
u64 sqlite3WhereOutputRowCount(WhereInfo*);
int sqlite3WhereIsDistinct(WhereInfo*);
int sqlite3WhereIsOrdered(WhereInfo*);
int sqlite3WhereIsSorted(WhereInfo*);
int sqlite3WhereContinueLabel(WhereInfo*);
int sqlite3WhereBreakLabel(WhereInfo*);
int sqlite3WhereOkOnePass(WhereInfo*, int*);
#define ONEPASS_OFF      0        /* Use of ONEPASS not allowed */
#define ONEPASS_SINGLE   1        /* ONEPASS valid for a single row update */
#define ONEPASS_MULTI    2        /* ONEPASS is valid for multiple rows */
void sqlite3ExprCodeLoadIndexColumn(Parse*, Index*, int, int, int);
int sqlite3ExprCodeGetColumn(Parse*, Table*, int, int, int, u8);
void sqlite3ExprCodeGetColumnOfTable(Vdbe*, Table*, int, int, int);
void sqlite3ExprCodeMove(Parse*, int, int, int);
void sqlite3ExprCacheStore(Parse*, int, int, int);
void sqlite3ExprCachePush(Parse*);
void sqlite3ExprCachePop(Parse*);
................................................................................
int sqlite3ExprIsConstantNotJoin(Expr*);
int sqlite3ExprIsConstantOrFunction(Expr*, u8);
int sqlite3ExprIsTableConstant(Expr*,int);
int sqlite3ExprIsInteger(Expr*, int*);
int sqlite3ExprCanBeNull(const Expr*);
int sqlite3ExprNeedsNoAffinityChange(const Expr*, char);
int sqlite3IsRowid(const char*);
void sqlite3GenerateRowDelete(
    Parse*,Table*,Trigger*,int,int,int,i16,u8,u8,u8,int);
void sqlite3GenerateRowIndexDelete(Parse*, Table*, int, int, int*, int);
int sqlite3GenerateIndexKey(Parse*, Index*, int, int, int, int*,Index*,int);
void sqlite3ResolvePartIdxLabel(Parse*,int);
void sqlite3GenerateConstraintChecks(Parse*,Table*,int*,int,int,int,int,
                                     u8,u8,int,int*);
void sqlite3CompleteInsertion(Parse*,Table*,int,int,int,int*,int,int,int);
int sqlite3OpenTableAndIndices(Parse*, Table*, int, int, u8*, int*, int*);
void sqlite3BeginWriteOperation(Parse*, int, int);

    }
  }
  zOut[16] = 0;
  sqlite3_result_text(context, zOut, -1, SQLITE_TRANSIENT);
}

/*
** tclcmd: test_extract(record, field)
**
** This function implements an SQL user-function that accepts a blob
** containing a formatted database record as the first argument. The
** second argument is the index of the field within that record to
** extract and return.
*/
static void test_extract(
................................................................................
    }

    if( mem.szMalloc ) sqlite3DbFree(db, mem.zMalloc);
  }
}

/*
** tclcmd: test_decode(record)
**
** This function implements an SQL user-function that accepts a blob
** containing a formatted database record as its only argument. It returns
** a tcl list (type SQLITE_TEXT) containing each of the values stored
** in the record.
*/
static void test_decode(
................................................................................
  }

  sqlite3_result_text(context, Tcl_GetString(pRet), -1, SQLITE_TRANSIENT);
  Tcl_DecrRefCount(pRet);
}

/*


** The implementation of scalar SQL function "test_zeroblob()". This is
** similar to the built-in zeroblob() function, except that it does not
** check that the integer parameter is within range before passing it
** to sqlite3_result_zeroblob().
*/
static void test_zeroblob(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  int nZero = sqlite3_value_int(argv[0]);
  sqlite3_result_zeroblob(context, nZero);
}


























static int registerTestFunctions(sqlite3 *db){
  static const struct {
     char *zName;
     signed char nArg;
     unsigned int eTextRep; /* 1: UTF-16.  0: UTF-8 */
     void (*xFunc)(sqlite3_context*,int,sqlite3_value **);
................................................................................
    { "test_eval",             1, SQLITE_UTF8, test_eval},
    { "test_isolation",        2, SQLITE_UTF8, test_isolation},
    { "test_counter",          1, SQLITE_UTF8, counterFunc},
    { "real2hex",              1, SQLITE_UTF8, real2hex},
    { "test_decode",           1, SQLITE_UTF8, test_decode},
    { "test_extract",          2, SQLITE_UTF8, test_extract},
    { "test_zeroblob",  1, SQLITE_UTF8|SQLITE_DETERMINISTIC, test_zeroblob},


  };
  int i;

  for(i=0; i<sizeof(aFuncs)/sizeof(aFuncs[0]); i++){
    sqlite3_create_function(db, aFuncs[i].zName, aFuncs[i].nArg,
        aFuncs[i].eTextRep, 0, aFuncs[i].xFunc, 0, 0);
  }

    }
  }
  zOut[16] = 0;
  sqlite3_result_text(context, zOut, -1, SQLITE_TRANSIENT);
}

/*
**     test_extract(record, field)
**
** This function implements an SQL user-function that accepts a blob
** containing a formatted database record as the first argument. The
** second argument is the index of the field within that record to
** extract and return.
*/
static void test_extract(
................................................................................
    }

    if( mem.szMalloc ) sqlite3DbFree(db, mem.zMalloc);
  }
}

/*
**      test_decode(record)
**
** This function implements an SQL user-function that accepts a blob
** containing a formatted database record as its only argument. It returns
** a tcl list (type SQLITE_TEXT) containing each of the values stored
** in the record.
*/
static void test_decode(
................................................................................
  }

  sqlite3_result_text(context, Tcl_GetString(pRet), -1, SQLITE_TRANSIENT);
  Tcl_DecrRefCount(pRet);
}

/*
**       test_zeroblob(N)
**
** The implementation of scalar SQL function "test_zeroblob()". This is
** similar to the built-in zeroblob() function, except that it does not
** check that the integer parameter is within range before passing it
** to sqlite3_result_zeroblob().
*/
static void test_zeroblob(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  int nZero = sqlite3_value_int(argv[0]);
  sqlite3_result_zeroblob(context, nZero);
}

/*         test_getsubtype(V)
**
** Return the subtype for value V.
*/
static void test_getsubtype(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  sqlite3_result_int(context, (int)sqlite3_value_subtype(argv[0]));
}

/*         test_setsubtype(V, T)
**
** Return the value V with its subtype changed to T
*/
static void test_setsubtype(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  sqlite3_result_value(context, argv[0]);
  sqlite3_result_subtype(context, (unsigned int)sqlite3_value_int(argv[1]));
}

static int registerTestFunctions(sqlite3 *db){
  static const struct {
     char *zName;
     signed char nArg;
     unsigned int eTextRep; /* 1: UTF-16.  0: UTF-8 */
     void (*xFunc)(sqlite3_context*,int,sqlite3_value **);
................................................................................
    { "test_eval",             1, SQLITE_UTF8, test_eval},
    { "test_isolation",        2, SQLITE_UTF8, test_isolation},
    { "test_counter",          1, SQLITE_UTF8, counterFunc},
    { "real2hex",              1, SQLITE_UTF8, real2hex},
    { "test_decode",           1, SQLITE_UTF8, test_decode},
    { "test_extract",          2, SQLITE_UTF8, test_extract},
    { "test_zeroblob",  1, SQLITE_UTF8|SQLITE_DETERMINISTIC, test_zeroblob},
    { "test_getsubtype",       1, SQLITE_UTF8, test_getsubtype},
    { "test_setsubtype",       2, SQLITE_UTF8, test_setsubtype},
  };
  int i;

  for(i=0; i<sizeof(aFuncs)/sizeof(aFuncs[0]); i++){
    sqlite3_create_function(db, aFuncs[i].zName, aFuncs[i].nArg,
        aFuncs[i].eTextRep, 0, aFuncs[i].xFunc, 0, 0);
  }

      if( pPk ){
        j1 = sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, 0, regKey, nKey);
      }else{
        j1 = sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, 0, regOldRowid);
      }
      VdbeCoverageNeverTaken(v);
    }
    sqlite3GenerateRowIndexDelete(pParse, pTab, iDataCur, iIdxCur, aRegIdx);
  
    /* If changing the record number, delete the old record.  */
    if( hasFK || chngKey || pPk!=0 ){
      sqlite3VdbeAddOp2(v, OP_Delete, iDataCur, 0);
    }
    if( bReplace || chngKey ){
      sqlite3VdbeJumpHere(v, j1);

      if( pPk ){
        j1 = sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, 0, regKey, nKey);
      }else{
        j1 = sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, 0, regOldRowid);
      }
      VdbeCoverageNeverTaken(v);
    }
    sqlite3GenerateRowIndexDelete(pParse, pTab, iDataCur, iIdxCur, aRegIdx, -1);
  
    /* If changing the record number, delete the old record.  */
    if( hasFK || chngKey || pPk!=0 ){
      sqlite3VdbeAddOp2(v, OP_Delete, iDataCur, 0);
    }
    if( bReplace || chngKey ){
      sqlite3VdbeJumpHere(v, j1);

}

/* Opcode: NotExists P1 P2 P3 * *
** Synopsis: intkey=r[P3]
**
** P1 is the index of a cursor open on an SQL table btree (with integer
** keys).  P3 is an integer rowid.  If P1 does not contain a record with
** rowid P3 then jump immediately to P2.  If P1 does contain a record

** with rowid P3 then leave the cursor pointing at that record and fall
** through to the next instruction.
**
** The OP_NotFound opcode performs the same operation on index btrees
** (with arbitrary multi-value keys).
**
** This opcode leaves the cursor in a state where it cannot be advanced
** in either direction.  In other words, the Next and Prev opcodes will
** not work following this opcode.
................................................................................
  assert( pC->isTable );
  assert( pC->pseudoTableReg==0 );
  pCrsr = pC->pCursor;
  assert( pCrsr!=0 );
  res = 0;
  iKey = pIn3->u.i;
  rc = sqlite3BtreeMovetoUnpacked(pCrsr, 0, iKey, 0, &res);

  pC->movetoTarget = iKey;  /* Used by OP_Delete */
  pC->nullRow = 0;
  pC->cacheStatus = CACHE_STALE;
  pC->deferredMoveto = 0;
  VdbeBranchTaken(res!=0,2);
  pC->seekResult = res;





  if( res!=0 ) goto jump_to_p2;


  break;
}

/* Opcode: Sequence P1 P2 * * *
** Synopsis: r[P2]=cursor[P1].ctr++
**
** Find the next available sequence number for cursor P1.
................................................................................
    assert( pC->isTable );
    db->xUpdateCallback(db->pUpdateArg, op, zDb, zTbl, iKey);
    assert( pC->iDb>=0 );
  }
  break;
}

/* Opcode: Delete P1 P2 * P4 *
**
** Delete the record at which the P1 cursor is currently pointing.
**
** The cursor will be left pointing at either the next or the previous
** record in the table. If it is left pointing at the next record, then
** the next Next instruction will be a no-op.  Hence it is OK to delete
** a record from within a Next loop.

**
** If the OPFLAG_NCHANGE flag of P2 is set, then the row change count is
** incremented (otherwise not).
**
** P1 must not be pseudo-table.  It has to be a real table with
** multiple rows.
**
................................................................................
** If P4 is not NULL, then it is the name of the table that P1 is
** pointing to.  The update hook will be invoked, if it exists.
** If P4 is not NULL then the P1 cursor must have been positioned
** using OP_NotFound prior to invoking this opcode.
*/
case OP_Delete: {
  VdbeCursor *pC;


  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  pC = p->apCsr[pOp->p1];
  assert( pC!=0 );
  assert( pC->pCursor!=0 );  /* Only valid for real tables, no pseudotables */
  assert( pC->deferredMoveto==0 );






#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 ){
    i64 iKey = 0;
    sqlite3BtreeKeySize(pC->pCursor, &iKey);
    assert( pC->movetoTarget==iKey ); 
  }
#endif
 
  rc = sqlite3BtreeDelete(pC->pCursor);
  pC->cacheStatus = CACHE_STALE;

  /* Invoke the update-hook if required. */
  if( rc==SQLITE_OK && db->xUpdateCallback && pOp->p4.z && pC->isTable ){
    db->xUpdateCallback(db->pUpdateArg, SQLITE_DELETE,
                        db->aDb[pC->iDb].zName, pOp->p4.z, pC->movetoTarget);
    assert( pC->iDb>=0 );
  }
  if( pOp->p2 & OPFLAG_NCHANGE ) p->nChange++;
  break;
}
................................................................................
  r.default_rc = 0;
  r.aMem = &aMem[pOp->p2];
#ifdef SQLITE_DEBUG
  { int i; for(i=0; i<r.nField; i++) assert( memIsValid(&r.aMem[i]) ); }
#endif
  rc = sqlite3BtreeMovetoUnpacked(pCrsr, &r, 0, 0, &res);
  if( rc==SQLITE_OK && res==0 ){
    rc = sqlite3BtreeDelete(pCrsr);
  }
  assert( pC->deferredMoveto==0 );
  pC->cacheStatus = CACHE_STALE;
  break;
}

/* Opcode: IdxRowid P1 P2 * * *

}

/* Opcode: NotExists P1 P2 P3 * *
** Synopsis: intkey=r[P3]
**
** P1 is the index of a cursor open on an SQL table btree (with integer
** keys).  P3 is an integer rowid.  If P1 does not contain a record with
** rowid P3 then jump immediately to P2.  Or, if P2 is 0, raise an
** SQLITE_CORRUPT error. If P1 does contain a record with rowid P3 then 
** leave the cursor pointing at that record and fall through to the next
** instruction.
**
** The OP_NotFound opcode performs the same operation on index btrees
** (with arbitrary multi-value keys).
**
** This opcode leaves the cursor in a state where it cannot be advanced
** in either direction.  In other words, the Next and Prev opcodes will
** not work following this opcode.
................................................................................
  assert( pC->isTable );
  assert( pC->pseudoTableReg==0 );
  pCrsr = pC->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;
  pC->cacheStatus = CACHE_STALE;
  pC->deferredMoveto = 0;
  VdbeBranchTaken(res!=0,2);
  pC->seekResult = res;
  if( res!=0 ){
    assert( rc==SQLITE_OK );
    if( pOp->p2==0 ){
      rc = SQLITE_CORRUPT_BKPT;
    }else{
      goto jump_to_p2;
    }
  }
  break;
}

/* Opcode: Sequence P1 P2 * * *
** Synopsis: r[P2]=cursor[P1].ctr++
**
** Find the next available sequence number for cursor P1.
................................................................................
    assert( pC->isTable );
    db->xUpdateCallback(db->pUpdateArg, op, zDb, zTbl, iKey);
    assert( pC->iDb>=0 );
  }
  break;
}

/* Opcode: Delete P1 P2 * P4 P5
**
** Delete the record at which the P1 cursor is currently pointing.
**
** If the P5 parameter is non-zero, the cursor will be left pointing at 
** either the next or the previous record in the table. If it is left 
** pointing at the next record, then the next Next instruction will be a 
** no-op. As a result, in this case it is OK to delete a record from within a
** Next loop. If P5 is zero, then the cursor is left in an undefined state.
**
** If the OPFLAG_NCHANGE flag of P2 is set, then the row change count is
** incremented (otherwise not).
**
** P1 must not be pseudo-table.  It has to be a real table with
** multiple rows.
**
................................................................................
** If P4 is not NULL, then it is the name of the table that P1 is
** pointing to.  The update hook will be invoked, if it exists.
** If P4 is not NULL then the P1 cursor must have been positioned
** using OP_NotFound prior to invoking this opcode.
*/
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->pCursor!=0 );  /* Only valid for real tables, no pseudotables */
  assert( pC->deferredMoveto==0 );

  hasUpdateCallback = db->xUpdateCallback && pOp->p4.z && pC->isTable;
  if( pOp->p5 && hasUpdateCallback ){
    sqlite3BtreeKeySize(pC->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->pCursor, &iKey);
    assert( pC->movetoTarget==iKey ); 
  }
#endif
 
  rc = sqlite3BtreeDelete(pC->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 );
  }
  if( pOp->p2 & OPFLAG_NCHANGE ) p->nChange++;
  break;
}
................................................................................
  r.default_rc = 0;
  r.aMem = &aMem[pOp->p2];
#ifdef SQLITE_DEBUG
  { int i; for(i=0; i<r.nField; i++) assert( memIsValid(&r.aMem[i]) ); }
#endif
  rc = sqlite3BtreeMovetoUnpacked(pCrsr, &r, 0, 0, &res);
  if( rc==SQLITE_OK && res==0 ){
    rc = sqlite3BtreeDelete(pCrsr, 0);
  }
  assert( pC->deferredMoveto==0 );
  pC->cacheStatus = CACHE_STALE;
  break;
}

/* Opcode: IdxRowid P1 P2 * * *

    int nZero;          /* Used when bit MEM_Zero is set in flags */
    FuncDef *pDef;      /* Used only when flags==MEM_Agg */
    RowSet *pRowSet;    /* Used only when flags==MEM_RowSet */
    VdbeFrame *pFrame;  /* Used when flags==MEM_Frame */
  } u;
  u16 flags;          /* Some combination of MEM_Null, MEM_Str, MEM_Dyn, etc. */
  u8  enc;            /* SQLITE_UTF8, SQLITE_UTF16BE, SQLITE_UTF16LE */

  int n;              /* Number of characters in string value, excluding '\0' */
  char *z;            /* String or BLOB value */
  /* ShallowCopy only needs to copy the information above */
  char *zMalloc;      /* Space to hold MEM_Str or MEM_Blob if szMalloc>0 */
  int szMalloc;       /* Size of the zMalloc allocation */
  u32 uTemp;          /* Transient storage for serial_type in OP_MakeRecord */
  sqlite3 *db;        /* The associated database connection */

    int nZero;          /* Used when bit MEM_Zero is set in flags */
    FuncDef *pDef;      /* Used only when flags==MEM_Agg */
    RowSet *pRowSet;    /* Used only when flags==MEM_RowSet */
    VdbeFrame *pFrame;  /* Used when flags==MEM_Frame */
  } u;
  u16 flags;          /* Some combination of MEM_Null, MEM_Str, MEM_Dyn, etc. */
  u8  enc;            /* SQLITE_UTF8, SQLITE_UTF16BE, SQLITE_UTF16LE */
  u8  eSubtype;       /* Subtype for this value */
  int n;              /* Number of characters in string value, excluding '\0' */
  char *z;            /* String or BLOB value */
  /* ShallowCopy only needs to copy the information above */
  char *zMalloc;      /* Space to hold MEM_Str or MEM_Blob if szMalloc>0 */
  int szMalloc;       /* Size of the zMalloc allocation */
  u32 uTemp;          /* Transient storage for serial_type in OP_MakeRecord */
  sqlite3 *db;        /* The associated database connection */

  return sqlite3VdbeRealValue((Mem*)pVal);
}
int sqlite3_value_int(sqlite3_value *pVal){
  return (int)sqlite3VdbeIntValue((Mem*)pVal);
}
sqlite_int64 sqlite3_value_int64(sqlite3_value *pVal){
  return sqlite3VdbeIntValue((Mem*)pVal);



}
const unsigned char *sqlite3_value_text(sqlite3_value *pVal){
  return (const unsigned char *)sqlite3ValueText(pVal, SQLITE_UTF8);
}
#ifndef SQLITE_OMIT_UTF16
const void *sqlite3_value_text16(sqlite3_value* pVal){
  return sqlite3ValueText(pVal, SQLITE_UTF16NATIVE);
................................................................................
void sqlite3_result_int64(sqlite3_context *pCtx, i64 iVal){
  assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
  sqlite3VdbeMemSetInt64(pCtx->pOut, iVal);
}
void sqlite3_result_null(sqlite3_context *pCtx){
  assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
  sqlite3VdbeMemSetNull(pCtx->pOut);




}
void sqlite3_result_text(
  sqlite3_context *pCtx, 
  const char *z, 
  int n,
  void (*xDel)(void *)
){
................................................................................
** IMPLEMENTATION-OF: R-46798-50301 The sqlite3_context_db_handle() interface
** returns a copy of the pointer to the database connection (the 1st
** parameter) of the sqlite3_create_function() and
** sqlite3_create_function16() routines that originally registered the
** application defined function.
*/
sqlite3 *sqlite3_context_db_handle(sqlite3_context *p){
  assert( p && p->pFunc );
  return p->pOut->db;
}

/*
** Return the current time for a statement.  If the current time
** is requested more than once within the same run of a single prepared
** statement, the exact same time is returned for each invocation regardless

  return sqlite3VdbeRealValue((Mem*)pVal);
}
int sqlite3_value_int(sqlite3_value *pVal){
  return (int)sqlite3VdbeIntValue((Mem*)pVal);
}
sqlite_int64 sqlite3_value_int64(sqlite3_value *pVal){
  return sqlite3VdbeIntValue((Mem*)pVal);
}
unsigned int sqlite3_value_subtype(sqlite3_value *pVal){
  return ((Mem*)pVal)->eSubtype;
}
const unsigned char *sqlite3_value_text(sqlite3_value *pVal){
  return (const unsigned char *)sqlite3ValueText(pVal, SQLITE_UTF8);
}
#ifndef SQLITE_OMIT_UTF16
const void *sqlite3_value_text16(sqlite3_value* pVal){
  return sqlite3ValueText(pVal, SQLITE_UTF16NATIVE);
................................................................................
void sqlite3_result_int64(sqlite3_context *pCtx, i64 iVal){
  assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
  sqlite3VdbeMemSetInt64(pCtx->pOut, iVal);
}
void sqlite3_result_null(sqlite3_context *pCtx){
  assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
  sqlite3VdbeMemSetNull(pCtx->pOut);
}
void sqlite3_result_subtype(sqlite3_context *pCtx, unsigned int eSubtype){
  assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
  pCtx->pOut->eSubtype = eSubtype & 0xff;
}
void sqlite3_result_text(
  sqlite3_context *pCtx, 
  const char *z, 
  int n,
  void (*xDel)(void *)
){
................................................................................
** IMPLEMENTATION-OF: R-46798-50301 The sqlite3_context_db_handle() interface
** returns a copy of the pointer to the database connection (the 1st
** parameter) of the sqlite3_create_function() and
** sqlite3_create_function16() routines that originally registered the
** application defined function.
*/
sqlite3 *sqlite3_context_db_handle(sqlite3_context *p){
  assert( p && p->pOut );
  return p->pOut->db;
}

/*
** Return the current time for a statement.  If the current time
** is requested more than once within the same run of a single prepared
** statement, the exact same time is returned for each invocation regardless

#ifdef SQLITE_ENABLE_EXPENSIVE_ASSERT
  /* If expensive assert() statements are available, do a linear search
  ** of the wal-index file content. Make sure the results agree with the
  ** result obtained using the hash indexes above.  */
  if( rc==SQLITE_OK ){
    u32 iRead2 = 0;
    u32 iTest;

    for(iTest=iLast; iTest>0; iTest--){
      if( walFramePgno(pWal, iTest)==pgno ){
        iRead2 = iTest;
        break;
      }
    }
    assert( iRead==iRead2 );
  }

#ifdef SQLITE_ENABLE_EXPENSIVE_ASSERT
  /* If expensive assert() statements are available, do a linear search
  ** of the wal-index file content. Make sure the results agree with the
  ** result obtained using the hash indexes above.  */
  if( rc==SQLITE_OK ){
    u32 iRead2 = 0;
    u32 iTest;
    assert( pWal->minFrame>0 );
    for(iTest=iLast; iTest>=pWal->minFrame; iTest--){
      if( walFramePgno(pWal, iTest)==pgno ){
        iRead2 = iTest;
        break;
      }
    }
    assert( iRead==iRead2 );
  }

** out of a WHERE loop.
*/
int sqlite3WhereBreakLabel(WhereInfo *pWInfo){
  return pWInfo->iBreak;
}

/*
** Return TRUE if an UPDATE or DELETE statement can operate directly on
** the rowids returned by a WHERE clause.  Return FALSE if doing an
** UPDATE or DELETE might change subsequent WHERE clause results.


**
** If the ONEPASS optimization is used (if this routine returns true)
** then also write the indices of open cursors used by ONEPASS
** into aiCur[0] and aiCur[1].  iaCur[0] gets the cursor of the data
** table and iaCur[1] gets the cursor used by an auxiliary index.
** Either value may be -1, indicating that cursor is not used.
** Any cursors returned will have been opened for writing.
**
** aiCur[0] and aiCur[1] both get -1 if the where-clause logic is
** unable to use the ONEPASS optimization.
*/
int sqlite3WhereOkOnePass(WhereInfo *pWInfo, int *aiCur){
  memcpy(aiCur, pWInfo->aiCurOnePass, sizeof(int)*2);
  return pWInfo->okOnePass;
}

/*
** Move the content of pSrc into pDest
*/
static void whereOrMove(WhereOrSet *pDest, WhereOrSet *pSrc){
  pDest->n = pSrc->n;
................................................................................
  WhereScan *pScan,       /* The WhereScan object being initialized */
  WhereClause *pWC,       /* The WHERE clause to be scanned */
  int iCur,               /* Cursor to scan for */
  int iColumn,            /* Column to scan for */
  u32 opMask,             /* Operator(s) to scan for */
  Index *pIdx             /* Must be compatible with this index */
){
  int j;

  /* memset(pScan, 0, sizeof(*pScan)); */
  pScan->pOrigWC = pWC;
  pScan->pWC = pWC;
  pScan->pIdxExpr = 0;
  if( pIdx ){
    j = iColumn;
................................................................................
  WhereMaskSet *pMaskSet;    /* The expression mask set */
  WhereLevel *pLevel;        /* A single level in pWInfo->a[] */
  WhereLoop *pLoop;          /* Pointer to a single WhereLoop object */
  int ii;                    /* Loop counter */
  sqlite3 *db;               /* Database connection */
  int rc;                    /* Return code */






  /* Variable initialization */
  db = pParse->db;
  memset(&sWLB, 0, sizeof(sWLB));

  /* An ORDER/GROUP BY clause of more than 63 terms cannot be optimized */
  testcase( pOrderBy && pOrderBy->nExpr==BMS-1 );
................................................................................
  pWInfo->pParse = pParse;
  pWInfo->pTabList = pTabList;
  pWInfo->pOrderBy = pOrderBy;
  pWInfo->pResultSet = pResultSet;
  pWInfo->iBreak = pWInfo->iContinue = sqlite3VdbeMakeLabel(v);
  pWInfo->wctrlFlags = wctrlFlags;
  pWInfo->savedNQueryLoop = pParse->nQueryLoop;

  pMaskSet = &pWInfo->sMaskSet;
  sWLB.pWInfo = pWInfo;
  sWLB.pWC = &pWInfo->sWC;
  sWLB.pNew = (WhereLoop*)(((char*)pWInfo)+nByteWInfo);
  assert( EIGHT_BYTE_ALIGNMENT(sWLB.pNew) );
  whereLoopInit(sWLB.pNew);
#ifdef SQLITE_DEBUG
................................................................................

  /* If the caller is an UPDATE or DELETE statement that is requesting
  ** to use a one-pass algorithm, determine if this is appropriate.
  ** The one-pass algorithm only works if the WHERE clause constrains
  ** the statement to update or delete a single row.
  */
  assert( (wctrlFlags & WHERE_ONEPASS_DESIRED)==0 || pWInfo->nLevel==1 );
  if( (wctrlFlags & WHERE_ONEPASS_DESIRED)!=0 
   && (pWInfo->a[0].pWLoop->wsFlags & WHERE_ONEROW)!=0 ){
    pWInfo->okOnePass = 1;




    if( HasRowid(pTabList->a[0].pTab) ){
      pWInfo->a[0].pWLoop->wsFlags &= ~WHERE_IDX_ONLY;

    }
  }

  /* Open all tables in the pTabList and any indices selected for
  ** searching those tables.
  */
  for(ii=0, pLevel=pWInfo->a; ii<nTabList; ii++, pLevel++){
................................................................................
    }else if( IsVirtual(pTab) ){
      /* noop */
    }else
#endif
    if( (pLoop->wsFlags & WHERE_IDX_ONLY)==0
         && (wctrlFlags & WHERE_OMIT_OPEN_CLOSE)==0 ){
      int op = OP_OpenRead;
      if( pWInfo->okOnePass ){
        op = OP_OpenWrite;
        pWInfo->aiCurOnePass[0] = pTabItem->iCursor;
      };
      sqlite3OpenTable(pParse, pTabItem->iCursor, iDb, pTab, op);
      assert( pTabItem->iCursor==pLevel->iTabCur );
      testcase( !pWInfo->okOnePass && pTab->nCol==BMS-1 );
      testcase( !pWInfo->okOnePass && pTab->nCol==BMS );
      if( !pWInfo->okOnePass && pTab->nCol<BMS && HasRowid(pTab) ){
        Bitmask b = pTabItem->colUsed;
        int n = 0;
        for(; b; b=b>>1, n++){}
        sqlite3VdbeChangeP4(v, sqlite3VdbeCurrentAddr(v)-1, 
                            SQLITE_INT_TO_PTR(n), P4_INT32);
        assert( n<=pTab->nCol );
      }
................................................................................
      if( !HasRowid(pTab) && IsPrimaryKeyIndex(pIx)
       && (wctrlFlags & WHERE_ONETABLE_ONLY)!=0
      ){
        /* This is one term of an OR-optimization using the PRIMARY KEY of a
        ** WITHOUT ROWID table.  No need for a separate index */
        iIndexCur = pLevel->iTabCur;
        op = 0;
      }else if( pWInfo->okOnePass ){
        Index *pJ = pTabItem->pTab->pIndex;
        iIndexCur = iIdxCur;
        assert( wctrlFlags & WHERE_ONEPASS_DESIRED );
        while( ALWAYS(pJ) && pJ!=pIx ){
          iIndexCur++;
          pJ = pJ->pNext;
        }
................................................................................
    ** created for the ONEPASS optimization.
    */
    if( (pTab->tabFlags & TF_Ephemeral)==0
     && pTab->pSelect==0
     && (pWInfo->wctrlFlags & WHERE_OMIT_OPEN_CLOSE)==0
    ){
      int ws = pLoop->wsFlags;
      if( !pWInfo->okOnePass && (ws & WHERE_IDX_ONLY)==0 ){
        sqlite3VdbeAddOp1(v, OP_Close, pTabItem->iCursor);
      }
      if( (ws & WHERE_INDEXED)!=0
       && (ws & (WHERE_IPK|WHERE_AUTO_INDEX))==0 
       && pLevel->iIdxCur!=pWInfo->aiCurOnePass[1]
      ){
        sqlite3VdbeAddOp1(v, OP_Close, pLevel->iIdxCur);

** out of a WHERE loop.
*/
int sqlite3WhereBreakLabel(WhereInfo *pWInfo){
  return pWInfo->iBreak;
}

/*
** Return ONEPASS_OFF (0) if an UPDATE or DELETE statement is unable to
** operate directly on the rowis returned by a WHERE clause.  Return
** ONEPASS_SINGLE (1) if the statement can operation directly because only
** a single row is to be changed.  Return ONEPASS_MULTI (2) if the one-pass
** optimization can be used on multiple 
**
** If the ONEPASS optimization is used (if this routine returns true)
** then also write the indices of open cursors used by ONEPASS
** into aiCur[0] and aiCur[1].  iaCur[0] gets the cursor of the data
** table and iaCur[1] gets the cursor used by an auxiliary index.
** Either value may be -1, indicating that cursor is not used.
** Any cursors returned will have been opened for writing.
**
** aiCur[0] and aiCur[1] both get -1 if the where-clause logic is
** unable to use the ONEPASS optimization.
*/
int sqlite3WhereOkOnePass(WhereInfo *pWInfo, int *aiCur){
  memcpy(aiCur, pWInfo->aiCurOnePass, sizeof(int)*2);
  return pWInfo->eOnePass;
}

/*
** Move the content of pSrc into pDest
*/
static void whereOrMove(WhereOrSet *pDest, WhereOrSet *pSrc){
  pDest->n = pSrc->n;
................................................................................
  WhereScan *pScan,       /* The WhereScan object being initialized */
  WhereClause *pWC,       /* The WHERE clause to be scanned */
  int iCur,               /* Cursor to scan for */
  int iColumn,            /* Column to scan for */
  u32 opMask,             /* Operator(s) to scan for */
  Index *pIdx             /* Must be compatible with this index */
){
  int j = 0;

  /* memset(pScan, 0, sizeof(*pScan)); */
  pScan->pOrigWC = pWC;
  pScan->pWC = pWC;
  pScan->pIdxExpr = 0;
  if( pIdx ){
    j = iColumn;
................................................................................
  WhereMaskSet *pMaskSet;    /* The expression mask set */
  WhereLevel *pLevel;        /* A single level in pWInfo->a[] */
  WhereLoop *pLoop;          /* Pointer to a single WhereLoop object */
  int ii;                    /* Loop counter */
  sqlite3 *db;               /* Database connection */
  int rc;                    /* Return code */

  assert( (wctrlFlags & WHERE_ONEPASS_MULTIROW)==0 || (
        (wctrlFlags & WHERE_ONEPASS_DESIRED)!=0 
     && (wctrlFlags & WHERE_OMIT_OPEN_CLOSE)==0 
  ));

  /* Variable initialization */
  db = pParse->db;
  memset(&sWLB, 0, sizeof(sWLB));

  /* An ORDER/GROUP BY clause of more than 63 terms cannot be optimized */
  testcase( pOrderBy && pOrderBy->nExpr==BMS-1 );
................................................................................
  pWInfo->pParse = pParse;
  pWInfo->pTabList = pTabList;
  pWInfo->pOrderBy = pOrderBy;
  pWInfo->pResultSet = pResultSet;
  pWInfo->iBreak = pWInfo->iContinue = sqlite3VdbeMakeLabel(v);
  pWInfo->wctrlFlags = wctrlFlags;
  pWInfo->savedNQueryLoop = pParse->nQueryLoop;
  assert( pWInfo->eOnePass==ONEPASS_OFF );  /* ONEPASS defaults to OFF */
  pMaskSet = &pWInfo->sMaskSet;
  sWLB.pWInfo = pWInfo;
  sWLB.pWC = &pWInfo->sWC;
  sWLB.pNew = (WhereLoop*)(((char*)pWInfo)+nByteWInfo);
  assert( EIGHT_BYTE_ALIGNMENT(sWLB.pNew) );
  whereLoopInit(sWLB.pNew);
#ifdef SQLITE_DEBUG
................................................................................

  /* If the caller is an UPDATE or DELETE statement that is requesting
  ** to use a one-pass algorithm, determine if this is appropriate.
  ** The one-pass algorithm only works if the WHERE clause constrains
  ** the statement to update or delete a single row.
  */
  assert( (wctrlFlags & WHERE_ONEPASS_DESIRED)==0 || pWInfo->nLevel==1 );
  if( (wctrlFlags & WHERE_ONEPASS_DESIRED)!=0 ){
    int wsFlags = pWInfo->a[0].pWLoop->wsFlags;
    int bOnerow = (wsFlags & WHERE_ONEROW)!=0;
    if( bOnerow || ( (wctrlFlags & WHERE_ONEPASS_MULTIROW)
       && 0==(wsFlags & WHERE_VIRTUALTABLE)
    )){
      pWInfo->eOnePass = bOnerow ? ONEPASS_SINGLE : ONEPASS_MULTI;
      if( HasRowid(pTabList->a[0].pTab) ){
        pWInfo->a[0].pWLoop->wsFlags &= ~WHERE_IDX_ONLY;
      }
    }
  }

  /* Open all tables in the pTabList and any indices selected for
  ** searching those tables.
  */
  for(ii=0, pLevel=pWInfo->a; ii<nTabList; ii++, pLevel++){
................................................................................
    }else if( IsVirtual(pTab) ){
      /* noop */
    }else
#endif
    if( (pLoop->wsFlags & WHERE_IDX_ONLY)==0
         && (wctrlFlags & WHERE_OMIT_OPEN_CLOSE)==0 ){
      int op = OP_OpenRead;
      if( pWInfo->eOnePass!=ONEPASS_OFF ){
        op = OP_OpenWrite;
        pWInfo->aiCurOnePass[0] = pTabItem->iCursor;
      };
      sqlite3OpenTable(pParse, pTabItem->iCursor, iDb, pTab, op);
      assert( pTabItem->iCursor==pLevel->iTabCur );
      testcase( pWInfo->eOnePass==ONEPASS_OFF && pTab->nCol==BMS-1 );
      testcase( pWInfo->eOnePass==ONEPASS_OFF && pTab->nCol==BMS );
      if( pWInfo->eOnePass==ONEPASS_OFF && pTab->nCol<BMS && HasRowid(pTab) ){
        Bitmask b = pTabItem->colUsed;
        int n = 0;
        for(; b; b=b>>1, n++){}
        sqlite3VdbeChangeP4(v, sqlite3VdbeCurrentAddr(v)-1, 
                            SQLITE_INT_TO_PTR(n), P4_INT32);
        assert( n<=pTab->nCol );
      }
................................................................................
      if( !HasRowid(pTab) && IsPrimaryKeyIndex(pIx)
       && (wctrlFlags & WHERE_ONETABLE_ONLY)!=0
      ){
        /* This is one term of an OR-optimization using the PRIMARY KEY of a
        ** WITHOUT ROWID table.  No need for a separate index */
        iIndexCur = pLevel->iTabCur;
        op = 0;
      }else if( pWInfo->eOnePass!=ONEPASS_OFF ){
        Index *pJ = pTabItem->pTab->pIndex;
        iIndexCur = iIdxCur;
        assert( wctrlFlags & WHERE_ONEPASS_DESIRED );
        while( ALWAYS(pJ) && pJ!=pIx ){
          iIndexCur++;
          pJ = pJ->pNext;
        }
................................................................................
    ** created for the ONEPASS optimization.
    */
    if( (pTab->tabFlags & TF_Ephemeral)==0
     && pTab->pSelect==0
     && (pWInfo->wctrlFlags & WHERE_OMIT_OPEN_CLOSE)==0
    ){
      int ws = pLoop->wsFlags;
      if( pWInfo->eOnePass==ONEPASS_OFF && (ws & WHERE_IDX_ONLY)==0 ){
        sqlite3VdbeAddOp1(v, OP_Close, pTabItem->iCursor);
      }
      if( (ws & WHERE_INDEXED)!=0
       && (ws & (WHERE_IPK|WHERE_AUTO_INDEX))==0 
       && pLevel->iIdxCur!=pWInfo->aiCurOnePass[1]
      ){
        sqlite3VdbeAddOp1(v, OP_Close, pLevel->iIdxCur);

  ExprList *pResultSet;     /* Result set. DISTINCT operates on these */
  WhereLoop *pLoops;        /* List of all WhereLoop objects */
  Bitmask revMask;          /* Mask of ORDER BY terms that need reversing */
  LogEst nRowOut;           /* Estimated number of output rows */
  u16 wctrlFlags;           /* Flags originally passed to sqlite3WhereBegin() */
  i8 nOBSat;                /* Number of ORDER BY terms satisfied by indices */
  u8 sorted;                /* True if really sorted (not just grouped) */
  u8 okOnePass;             /* Ok to use one-pass algorithm for UPDATE/DELETE */
  u8 untestedTerms;         /* Not all WHERE terms resolved by outer loop */
  u8 eDistinct;             /* One of the WHERE_DISTINCT_* values below */
  u8 nLevel;                /* Number of nested loop */
  int iTop;                 /* The very beginning of the WHERE loop */
  int iContinue;            /* Jump here to continue with next record */
  int iBreak;               /* Jump here to break out of the loop */
  int savedNQueryLoop;      /* pParse->nQueryLoop outside the WHERE loop */

  ExprList *pResultSet;     /* Result set. DISTINCT operates on these */
  WhereLoop *pLoops;        /* List of all WhereLoop objects */
  Bitmask revMask;          /* Mask of ORDER BY terms that need reversing */
  LogEst nRowOut;           /* Estimated number of output rows */
  u16 wctrlFlags;           /* Flags originally passed to sqlite3WhereBegin() */
  i8 nOBSat;                /* Number of ORDER BY terms satisfied by indices */
  u8 sorted;                /* True if really sorted (not just grouped) */
  u8 eOnePass;              /* ONEPASS_OFF, or _SINGLE, or _MULTI */
  u8 untestedTerms;         /* Not all WHERE terms resolved by outer loop */
  u8 eDistinct;             /* One of the WHERE_DISTINCT_* values below */
  u8 nLevel;                /* Number of nested loop */
  int iTop;                 /* The very beginning of the WHERE loop */
  int iContinue;            /* Jump here to continue with next record */
  int iBreak;               /* Jump here to break out of the loop */
  int savedNQueryLoop;      /* pParse->nQueryLoop outside the WHERE loop */

    disableTerm(pLevel, pRangeEnd);
    if( omitTable ){
      /* pIdx is a covering index.  No need to access the main table. */
    }else if( HasRowid(pIdx->pTable) ){
      iRowidReg = ++pParse->nMem;
      sqlite3VdbeAddOp2(v, OP_IdxRowid, iIdxCur, iRowidReg);
      sqlite3ExprCacheStore(pParse, iCur, -1, iRowidReg);




      sqlite3VdbeAddOp2(v, OP_Seek, iCur, iRowidReg);  /* Deferred seek */

    }else if( iCur!=iIdxCur ){
      Index *pPk = sqlite3PrimaryKeyIndex(pIdx->pTable);
      iRowidReg = sqlite3GetTempRange(pParse, pPk->nKeyCol);
      for(j=0; j<pPk->nKeyCol; j++){
        k = sqlite3ColumnOfIndex(pIdx, pPk->aiColumn[j]);
        sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, k, iRowidReg+j);
      }

    disableTerm(pLevel, pRangeEnd);
    if( omitTable ){
      /* pIdx is a covering index.  No need to access the main table. */
    }else if( HasRowid(pIdx->pTable) ){
      iRowidReg = ++pParse->nMem;
      sqlite3VdbeAddOp2(v, OP_IdxRowid, iIdxCur, iRowidReg);
      sqlite3ExprCacheStore(pParse, iCur, -1, iRowidReg);
      if( pWInfo->eOnePass!=ONEPASS_OFF ){
        sqlite3VdbeAddOp3(v, OP_NotExists, iCur, 0, iRowidReg);
        VdbeCoverage(v);
      }else{
        sqlite3VdbeAddOp2(v, OP_Seek, iCur, iRowidReg);  /* Deferred seek */
      }
    }else if( iCur!=iIdxCur ){
      Index *pPk = sqlite3PrimaryKeyIndex(pIdx->pTable);
      iRowidReg = sqlite3GetTempRange(pParse, pPk->nKeyCol);
      for(j=0; j<pPk->nKeyCol; j++){
        k = sqlite3ColumnOfIndex(pIdx, pPk->aiColumn[j]);
        sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, k, iRowidReg+j);
      }

do_test delete-3.1.6.2 {
  db changes
} 1
do_test delete-3.1.7 {
  execsql {SELECT * FROM table1 ORDER BY f1}
} {1 2 4 16}
integrity_check delete-3.2


# Semantic errors in the WHERE clause
#
do_test delete-4.1 {
  execsql {CREATE TABLE table2(f1 int, f2 int)}
  set v [catch {execsql {DELETE FROM table2 WHERE f3=5}} msg]
  lappend v $msg

do_test delete-3.1.6.2 {
  db changes
} 1
do_test delete-3.1.7 {
  execsql {SELECT * FROM table1 ORDER BY f1}
} {1 2 4 16}
integrity_check delete-3.2


# Semantic errors in the WHERE clause
#
do_test delete-4.1 {
  execsql {CREATE TABLE table2(f1 int, f2 int)}
  set v [catch {execsql {DELETE FROM table2 WHERE f3=5}} msg]
  lappend v $msg

# 2005 August 24
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this script is a test of the DELETE command.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
set testprefix delete4

do_execsql_test 1.1 {
  CREATE TABLE t1(x INTEGER PRIMARY KEY, y);
  INSERT INTO t1 VALUES(1, 0);
  INSERT INTO t1 VALUES(2, 1);
  INSERT INTO t1 VALUES(3, 0);
  INSERT INTO t1 VALUES(4, 1);
  INSERT INTO t1 VALUES(5, 0);
  INSERT INTO t1 VALUES(6, 1);
  INSERT INTO t1 VALUES(7, 0);
  INSERT INTO t1 VALUES(8, 1);
}
do_execsql_test 1.2 {
  DELETE FROM t1 WHERE y=1;
}
do_execsql_test 1.3 {
  SELECT x FROM t1;
} {1 3 5 7}

#-------------------------------------------------------------------------
#
reset_db
do_execsql_test 2.1 {
  CREATE TABLE t1(x INTEGER PRIMARY KEY, y, z);
  INSERT INTO t1 VALUES(1, 0, randomblob(200));
  INSERT INTO t1 VALUES(2, 1, randomblob(200));
  INSERT INTO t1 VALUES(3, 0, randomblob(200));
  INSERT INTO t1 VALUES(4, 1, randomblob(200));
  INSERT INTO t1 VALUES(5, 0, randomblob(200));
  INSERT INTO t1 VALUES(6, 1, randomblob(200));
  INSERT INTO t1 VALUES(7, 0, randomblob(200));
  INSERT INTO t1 VALUES(8, 1, randomblob(200));
}
do_execsql_test 2.2 {
  DELETE FROM t1 WHERE y=1;
}
do_execsql_test 2.3 {
  SELECT x FROM t1;
} {1 3 5 7}


#-------------------------------------------------------------------------
#
reset_db
do_execsql_test 3.1 {
  CREATE TABLE t1(a, b, PRIMARY KEY(a, b)) WITHOUT ROWID;
  INSERT INTO t1 VALUES(1, 2);
  INSERT INTO t1 VALUES(2, 4);
  INSERT INTO t1 VALUES(1, 5);
  DELETE FROM t1 WHERE a=1;
  SELECT * FROM t1;
} {2 4}

#-------------------------------------------------------------------------
# DELETE statement that uses the OR optimization
#
reset_db
do_execsql_test 3.1 {
  CREATE TABLE t1(i INTEGER PRIMARY KEY, a, b);
  CREATE INDEX i1a ON t1(a);
  CREATE INDEX i1b ON t1(b);
  INSERT INTO t1 VALUES(1, 'one', 'i');
  INSERT INTO t1 VALUES(2, 'two', 'ii');
  INSERT INTO t1 VALUES(3, 'three', 'iii');
  INSERT INTO t1 VALUES(4, 'four', 'iv');
  INSERT INTO t1 VALUES(5, 'one', 'i');
  INSERT INTO t1 VALUES(6, 'two', 'ii');
  INSERT INTO t1 VALUES(7, 'three', 'iii');
  INSERT INTO t1 VALUES(8, 'four', 'iv');
} {}

do_execsql_test 3.2 {
  DELETE FROM t1 WHERE a='two' OR b='iv';
}

do_execsql_test 3.3 {
  SELECT i FROM t1 ORDER BY i;
} {1 3 5 7}

do_execsql_test 3.4 { 
  PRAGMA integrity_check; 
} {ok}


finish_test

  2    "CREATE TABLE temp.sqlitehelloworld(x)"   {}
  3    {CREATE TABLE auxa."sqlite"(x, y)}        {}
  4    {CREATE TABLE auxb."sqlite-"(z)}          {}
  5    {CREATE TABLE "SQLITE-TBL"(z)}            {}
}


# EVIDENCE-OF: R-10195-31023 If a <database-name> is specified, it
# must be either "main", "temp", or the name of an attached database.
#
# EVIDENCE-OF: R-39822-07822 In this case the new table is created in
# the named database.
#
#   Test cases 1.2.* test the first of the two requirements above. The
#   second is verified by cases 1.3.*.
#
................................................................................
  array set X [table_list]
  list $X(main) $X(temp) $X(auxa) $X(auxb)
} {
  1    "CREATE TEMP TABLE t1(a, b)"      {{} t1 {} {}}
  2    "CREATE TEMPORARY TABLE t2(a, b)" {{} {t1 t2} {} {}}
}

# EVIDENCE-OF: R-49439-47561 It is an error to specify both a
# <database-name> and the TEMP or TEMPORARY keyword, unless the
# <database-name> is "temp".
#
drop_all_tables
do_createtable_tests 1.5.1 -error {
  temporary table name must be unqualified
} {
  1    "CREATE TEMP TABLE main.t1(a, b)"        {}
  2    "CREATE TEMPORARY TABLE auxa.t2(a, b)"   {}
................................................................................
} {
  1    "CREATE TEMP TABLE temp.t1(a, b)"        {{} t1 {} {}}
  2    "CREATE TEMPORARY TABLE temp.t2(a, b)"   {{} {t1 t2} {} {}}
  3    "CREATE TEMP TABLE TEMP.t3(a, b)"        {{} {t1 t2 t3} {} {}}
  4    "CREATE TEMPORARY TABLE TEMP.xxx(x)"     {{} {t1 t2 t3 xxx} {} {}}
}

# EVIDENCE-OF: R-00917-09393 If no database name is specified and the
# TEMP keyword is not present then the table is created in the main
# database.
#
drop_all_tables
do_createtable_tests 1.6 -tclquery {
  unset -nocomplain X
  array set X [table_list]
  list $X(main) $X(temp) $X(auxa) $X(auxb)
} {

  2    "CREATE TABLE temp.sqlitehelloworld(x)"   {}
  3    {CREATE TABLE auxa."sqlite"(x, y)}        {}
  4    {CREATE TABLE auxb."sqlite-"(z)}          {}
  5    {CREATE TABLE "SQLITE-TBL"(z)}            {}
}


# EVIDENCE-OF: R-18448-33677 If a schema-name is specified, it must be
# either "main", "temp", or the name of an attached database.
#
# EVIDENCE-OF: R-39822-07822 In this case the new table is created in
# the named database.
#
#   Test cases 1.2.* test the first of the two requirements above. The
#   second is verified by cases 1.3.*.
#
................................................................................
  array set X [table_list]
  list $X(main) $X(temp) $X(auxa) $X(auxb)
} {
  1    "CREATE TEMP TABLE t1(a, b)"      {{} t1 {} {}}
  2    "CREATE TEMPORARY TABLE t2(a, b)" {{} {t1 t2} {} {}}
}

# EVIDENCE-OF: R-23976-43329 It is an error to specify both a
# schema-name and the TEMP or TEMPORARY keyword, unless the schema-name
# is "temp".
#
drop_all_tables
do_createtable_tests 1.5.1 -error {
  temporary table name must be unqualified
} {
  1    "CREATE TEMP TABLE main.t1(a, b)"        {}
  2    "CREATE TEMPORARY TABLE auxa.t2(a, b)"   {}
................................................................................
} {
  1    "CREATE TEMP TABLE temp.t1(a, b)"        {{} t1 {} {}}
  2    "CREATE TEMPORARY TABLE temp.t2(a, b)"   {{} {t1 t2} {} {}}
  3    "CREATE TEMP TABLE TEMP.t3(a, b)"        {{} {t1 t2 t3} {} {}}
  4    "CREATE TEMPORARY TABLE TEMP.xxx(x)"     {{} {t1 t2 t3 xxx} {} {}}
}

# EVIDENCE-OF: R-31997-24564 If no schema name is specified and the TEMP
# keyword is not present then the table is created in the main database.

#
drop_all_tables
do_createtable_tests 1.6 -tclquery {
  unset -nocomplain X
  array set X [table_list]
  list $X(main) $X(temp) $X(auxa) $X(auxb)
} {

  }
} {}
do_delete_tests e_delete-1.1 {
  1  "DELETE FROM t1       ; SELECT * FROM t1"       {}
  2  "DELETE FROM main.t2  ; SELECT * FROM t2"       {}
}

# EVIDENCE-OF: R-30203-16177 If a WHERE clause is supplied, then only
# those rows for which the result of evaluating the WHERE clause as a
# boolean expression is true are deleted.



#
do_delete_tests e_delete-1.2 {
  1  "DELETE FROM t3 WHERE 1       ; SELECT x FROM t3"       {}
  2  "DELETE FROM main.t4 WHERE 0  ; SELECT x FROM t4"       {1 2 3 4 5}
  3  "DELETE FROM t4 WHERE 0.0     ; SELECT x FROM t4"       {1 2 3 4 5}
  4  "DELETE FROM t4 WHERE NULL    ; SELECT x FROM t4"       {1 2 3 4 5}
  5  "DELETE FROM t4 WHERE y!='two'; SELECT x FROM t4"       {2}
................................................................................
  CREATE TABLE aux2.t10(a, b);  INSERT INTO aux2.t10 VALUES(1, 2);
} {}


# EVIDENCE-OF: R-09681-58560 The table-name specified as part of a
# DELETE statement within a trigger body must be unqualified.
#
# EVIDENCE-OF: R-36771-43788 In other words, the database-name. prefix
# on the table name is not allowed within triggers.
#
do_delete_tests e_delete-2.1 -error {
  qualified table names are not allowed on INSERT, UPDATE, and DELETE statements within triggers
} {
  1 {
      CREATE TRIGGER tr1 AFTER INSERT ON t1 BEGIN
        DELETE FROM main.t2;

  }
} {}
do_delete_tests e_delete-1.1 {
  1  "DELETE FROM t1       ; SELECT * FROM t1"       {}
  2  "DELETE FROM main.t2  ; SELECT * FROM t2"       {}
}

# EVIDENCE-OF: R-26300-50198 If a WHERE clause is supplied, then only
# those rows for which the WHERE clause boolean expression is true are
# deleted.
#
# EVIDENCE-OF: R-23360-48280 Rows for which the expression is false or
# NULL are retained.
#
do_delete_tests e_delete-1.2 {
  1  "DELETE FROM t3 WHERE 1       ; SELECT x FROM t3"       {}
  2  "DELETE FROM main.t4 WHERE 0  ; SELECT x FROM t4"       {1 2 3 4 5}
  3  "DELETE FROM t4 WHERE 0.0     ; SELECT x FROM t4"       {1 2 3 4 5}
  4  "DELETE FROM t4 WHERE NULL    ; SELECT x FROM t4"       {1 2 3 4 5}
  5  "DELETE FROM t4 WHERE y!='two'; SELECT x FROM t4"       {2}
................................................................................
  CREATE TABLE aux2.t10(a, b);  INSERT INTO aux2.t10 VALUES(1, 2);
} {}


# EVIDENCE-OF: R-09681-58560 The table-name specified as part of a
# DELETE statement within a trigger body must be unqualified.
#
# EVIDENCE-OF: R-12275-20298 In other words, the schema-name. prefix on
# the table name is not allowed within triggers.
#
do_delete_tests e_delete-2.1 -error {
  qualified table names are not allowed on INSERT, UPDATE, and DELETE statements within triggers
} {
  1 {
      CREATE TRIGGER tr1 AFTER INSERT ON t1 BEGIN
        DELETE FROM main.t2;

do_execsql_test e_expr-27.1.2 {
  SELECT 
    typeof(CAST(X'555655' as TEXT)), CAST(X'555655' as TEXT),
    typeof(CAST('1.23abc' as REAL)), CAST('1.23abc' as REAL),
    typeof(CAST(4.5 as INTEGER)), CAST(4.5 as INTEGER)
} {text UVU real 1.23 integer 4}

# EVIDENCE-OF: R-27225-65050 If the value of <expr> is NULL, then
# the result of the CAST expression is also NULL.
#
do_expr_test e_expr-27.2.1 { CAST(NULL AS integer) } null {}
do_expr_test e_expr-27.2.2 { CAST(NULL AS text) }    null {}
do_expr_test e_expr-27.2.3 { CAST(NULL AS blob) }    null {}
do_expr_test e_expr-27.2.4 { CAST(NULL AS number) }  null {}

# EVIDENCE-OF: R-31076-23575 Casting a value to a <type-name> with
# no affinity causes the value to be converted into a BLOB.
#
do_expr_test e_expr-27.3.1 { CAST('abc' AS blob)       } blob abc
do_expr_test e_expr-27.3.2 { CAST('def' AS shobblob_x) } blob def
do_expr_test e_expr-27.3.3 { CAST('ghi' AS abbLOb10)   } blob ghi

# EVIDENCE-OF: R-22956-37754 Casting to a BLOB consists of first casting
# the value to TEXT in the encoding of the database connection, then

do_execsql_test e_expr-27.1.2 {
  SELECT 
    typeof(CAST(X'555655' as TEXT)), CAST(X'555655' as TEXT),
    typeof(CAST('1.23abc' as REAL)), CAST('1.23abc' as REAL),
    typeof(CAST(4.5 as INTEGER)), CAST(4.5 as INTEGER)
} {text UVU real 1.23 integer 4}

# EVIDENCE-OF: R-32434-09092 If the value of expr is NULL, then the
# result of the CAST expression is also NULL.
#
do_expr_test e_expr-27.2.1 { CAST(NULL AS integer) } null {}
do_expr_test e_expr-27.2.2 { CAST(NULL AS text) }    null {}
do_expr_test e_expr-27.2.3 { CAST(NULL AS blob) }    null {}
do_expr_test e_expr-27.2.4 { CAST(NULL AS number) }  null {}

# EVIDENCE-OF: R-43522-35548 Casting a value to a type-name with no
# affinity causes the value to be converted into a BLOB.
#
do_expr_test e_expr-27.3.1 { CAST('abc' AS blob)       } blob abc
do_expr_test e_expr-27.3.2 { CAST('def' AS shobblob_x) } blob def
do_expr_test e_expr-27.3.3 { CAST('ghi' AS abbLOb10)   } blob ghi

# EVIDENCE-OF: R-22956-37754 Casting to a BLOB consists of first casting
# the value to TEXT in the encoding of the database connection, then

    2a   "INSERT INTO a2(a, b) VALUES(1, 2)" {}
    2b   "SELECT count(*) FROM a2"           {2}

    3a   "INSERT INTO a2(a) VALUES(3),(4)"   {}
    3b   "SELECT count(*) FROM a2"           {4}
}

# EVIDENCE-OF: R-53616-44976 If no column-list is specified then the
# number of values inserted into each row must be the same as the number
# of columns in the table.
#
#   A test in the block above verifies that if the VALUES list has the
#   correct number of columns (for table a2, 3 columns) works. So these
#   tests just show that other values cause an error.
#
do_insert_tests e_insert-1.2 -error { 
  table %s has %d columns but %d values were supplied
................................................................................
    2a   "INSERT INTO a2 VALUES('abc', NULL, 3*3+1)"      {}
    2b   "SELECT * FROM a2 WHERE oid=last_insert_rowid()" {abc {} 10}

    3a   "INSERT INTO a2 VALUES((SELECT count(*) FROM a2), 'x', 'y')" {}
    3b   "SELECT * FROM a2 WHERE oid=last_insert_rowid()" {2 x y}
}

# EVIDENCE-OF: R-09234-17933 If a column-list is specified, then the
# number of values in each term of the VALUE list must match the number
# of specified columns.
#
do_insert_tests e_insert-1.4 -error { 
  %d values for %d columns
} {
    1    "INSERT INTO a2(a, b, c) VALUES(1)"         {1 3}
    2    "INSERT INTO a2(a, b, c) VALUES(1,2)"       {2 3}
    3    "INSERT INTO a2(a, b, c) VALUES(1,2,3,4)"   {4 3}
................................................................................
  2.2  "REPLACE INTO a4 VALUES(2, 'f')" {}  1 {1 a 3 a 4 e 2 f}
} {
  do_catchsql_test e_insert-4.1.$tn.1 $sql [list [expr {$error!=""}] $error]
  do_execsql_test  e_insert-4.1.$tn.2 {SELECT * FROM a4} [list {*}$data]
  do_test          e_insert-4.1.$tn.3 {sqlite3_get_autocommit db} $ac
}

# EVIDENCE-OF: R-64196-02418 The optional "database-name." prefix on the
# table-name is support for top-level INSERT statements only.
#
# EVIDENCE-OF: R-05731-00924 The table name must be unqualified for
# INSERT statements that occur within CREATE TRIGGER statements.
#
set err {1 {qualified table names are not allowed on INSERT, UPDATE, and DELETE statements within triggers}}

do_catchsql_test e_insert-5.1.1 {

    2a   "INSERT INTO a2(a, b) VALUES(1, 2)" {}
    2b   "SELECT count(*) FROM a2"           {2}

    3a   "INSERT INTO a2(a) VALUES(3),(4)"   {}
    3b   "SELECT count(*) FROM a2"           {4}
}

# EVIDENCE-OF: R-19218-01018 If the column-name list after table-name is
# omitted then the number of values inserted into each row must be the
# same as the number of columns in the table.
#
#   A test in the block above verifies that if the VALUES list has the
#   correct number of columns (for table a2, 3 columns) works. So these
#   tests just show that other values cause an error.
#
do_insert_tests e_insert-1.2 -error { 
  table %s has %d columns but %d values were supplied
................................................................................
    2a   "INSERT INTO a2 VALUES('abc', NULL, 3*3+1)"      {}
    2b   "SELECT * FROM a2 WHERE oid=last_insert_rowid()" {abc {} 10}

    3a   "INSERT INTO a2 VALUES((SELECT count(*) FROM a2), 'x', 'y')" {}
    3b   "SELECT * FROM a2 WHERE oid=last_insert_rowid()" {2 x y}
}

# EVIDENCE-OF: R-21115-58321 If a column-name list is specified, then
# the number of values in each term of the VALUE list must match the
# number of specified columns.
#
do_insert_tests e_insert-1.4 -error { 
  %d values for %d columns
} {
    1    "INSERT INTO a2(a, b, c) VALUES(1)"         {1 3}
    2    "INSERT INTO a2(a, b, c) VALUES(1,2)"       {2 3}
    3    "INSERT INTO a2(a, b, c) VALUES(1,2,3,4)"   {4 3}
................................................................................
  2.2  "REPLACE INTO a4 VALUES(2, 'f')" {}  1 {1 a 3 a 4 e 2 f}
} {
  do_catchsql_test e_insert-4.1.$tn.1 $sql [list [expr {$error!=""}] $error]
  do_execsql_test  e_insert-4.1.$tn.2 {SELECT * FROM a4} [list {*}$data]
  do_test          e_insert-4.1.$tn.3 {sqlite3_get_autocommit db} $ac
}

# EVIDENCE-OF: R-59829-49719 The optional "schema-name." prefix on the
# table-name is supported for top-level INSERT statements only.
#
# EVIDENCE-OF: R-05731-00924 The table name must be unqualified for
# INSERT statements that occur within CREATE TRIGGER statements.
#
set err {1 {qualified table names are not allowed on INSERT, UPDATE, and DELETE statements within triggers}}

do_catchsql_test e_insert-5.1.1 {

test_index 5.37  t1     collA   length
test_index 5.38  t1     collB   value
test_index 5.39  t2     collA   length
test_index 5.40  t2     collB   value
test_index 5.41  aux.t1 collA   length
test_index 5.42  aux.t1 collB   value

# EVIDENCE-OF: R-15639-02023 If no database-name is specified and there
# exists both a table or index and a collation sequence of the specified
# name, SQLite interprets this as a request to rebuild the indices that
# use the named collation sequence.
#
set_collations value length
do_execsql_test e_reindex-2.6.0 {
  CREATE TABLE collA(x);
  CREATE INDEX icolla_a ON collA(x COLLATE collA);
  CREATE INDEX icolla_b ON collA(x COLLATE collB);

test_index 5.37  t1     collA   length
test_index 5.38  t1     collB   value
test_index 5.39  t2     collA   length
test_index 5.40  t2     collB   value
test_index 5.41  aux.t1 collA   length
test_index 5.42  aux.t1 collB   value

# EVIDENCE-OF: R-35892-30289 For a command of the form "REINDEX name", a
# match against collation-name takes precedence over a match against
# index-name or table-name.

#
set_collations value length
do_execsql_test e_reindex-2.6.0 {
  CREATE TABLE collA(x);
  CREATE INDEX icolla_a ON collA(x COLLATE collA);
  CREATE INDEX icolla_b ON collA(x COLLATE collB);

#
resolve_reopen_db
do_execsql_test 1.1 { SELECT * FROM n1 } {temp n1}
do_execsql_test 1.2 { SELECT * FROM n2 } {main n2}
do_execsql_test 1.3 { SELECT * FROM n3 } {at1  n3}
do_execsql_test 1.4 { SELECT * FROM n4 } {at2  n4}

# EVIDENCE-OF: R-54577-28142 If a database name is specified as part of
# an object reference, it must be either "main", or "temp" or the name
# of an attached database.
#
#   Or else it is a "no such table: xxx" error.
#
resolve_reopen_db
do_execsql_test 2.1.1 { SELECT * FROM main.n1 } {main n1}
do_execsql_test 2.1.2 { SELECT * FROM temp.n1 } {temp n1}
do_execsql_test 2.1.3 { SELECT * FROM at1.n1 } {at1 n1}
do_execsql_test 2.1.4 { SELECT * FROM at2.n1 } {at2 n1}

do_catchsql_test 2.2 { SELECT * FROM xxx.n1 } {1 {no such table: xxx.n1}}

# EVIDENCE-OF: R-26223-47623 Like other SQL identifiers, database names
# are case-insensitive.
#
resolve_reopen_db
do_execsql_test 3.1 { SELECT * FROM MAIN.n1 } {main n1}
do_execsql_test 3.2 { SELECT * FROM tEmP.n1 } {temp n1}
do_execsql_test 3.3 { SELECT * FROM aT1.n1 } {at1 n1}
do_execsql_test 3.4 { SELECT * FROM At2.n1 } {at2 n1}

# EVIDENCE-OF: R-15639-28392 If a database name is specified, then only
# the named database is searched for the named object.
#
do_catchsql_test 4.1 { SELECT * FROM temp.n2 } {1 {no such table: temp.n2}}
do_catchsql_test 4.2 { SELECT * FROM main.n2 } {0 {main n2}}
do_catchsql_test 4.3 { SELECT * FROM at1.n2 }  {0 {at1 n2}}
do_catchsql_test 4.4 { SELECT * FROM at2.n2 }  {0 {at2 n2}}

# EVIDENCE-OF: R-08951-19801 When searching database schemas for a named

#
resolve_reopen_db
do_execsql_test 1.1 { SELECT * FROM n1 } {temp n1}
do_execsql_test 1.2 { SELECT * FROM n2 } {main n2}
do_execsql_test 1.3 { SELECT * FROM n3 } {at1  n3}
do_execsql_test 1.4 { SELECT * FROM n4 } {at2  n4}

# EVIDENCE-OF: R-00634-08585 If a schema name is specified as part of an
# object reference, it must be either "main", or "temp" or the
# schema-name of an attached database.
#
#   Or else it is a "no such table: xxx" error.
#
resolve_reopen_db
do_execsql_test 2.1.1 { SELECT * FROM main.n1 } {main n1}
do_execsql_test 2.1.2 { SELECT * FROM temp.n1 } {temp n1}
do_execsql_test 2.1.3 { SELECT * FROM at1.n1 } {at1 n1}
do_execsql_test 2.1.4 { SELECT * FROM at2.n1 } {at2 n1}

do_catchsql_test 2.2 { SELECT * FROM xxx.n1 } {1 {no such table: xxx.n1}}

# EVIDENCE-OF: R-17446-42210 Like other SQL identifiers, schema names
# are case-insensitive.
#
resolve_reopen_db
do_execsql_test 3.1 { SELECT * FROM MAIN.n1 } {main n1}
do_execsql_test 3.2 { SELECT * FROM tEmP.n1 } {temp n1}
do_execsql_test 3.3 { SELECT * FROM aT1.n1 } {at1 n1}
do_execsql_test 3.4 { SELECT * FROM At2.n1 } {at2 n1}

# EVIDENCE-OF: R-14755-58619 If a schema name is specified, then only
# that one schema is searched for the named object.
#
do_catchsql_test 4.1 { SELECT * FROM temp.n2 } {1 {no such table: temp.n2}}
do_catchsql_test 4.2 { SELECT * FROM main.n2 } {0 {main n2}}
do_catchsql_test 4.3 { SELECT * FROM at1.n2 }  {0 {at1 n2}}
do_catchsql_test 4.4 { SELECT * FROM at2.n2 }  {0 {at2 n2}}

# EVIDENCE-OF: R-08951-19801 When searching database schemas for a named

  1  "UPDATE t1 SET b = 'roman' ; SELECT * FROM t1"
     {1 roman  2 roman  3 roman}

  2  "UPDATE t1 SET a = 'greek' ; SELECT * FROM t1"
     {greek roman  greek roman  greek roman}
}

# EVIDENCE-OF: R-42117-40023 Otherwise, the UPDATE affects only those
# rows for which the result of evaluating the WHERE clause expression as
# a boolean expression is true.
#
do_execsql_test e_update-1.3.0 {
  DELETE FROM main.t1;
  INSERT INTO main.t1 VALUES(NULL, '');
  INSERT INTO main.t1 VALUES(1, 'i');
  INSERT INTO main.t1 VALUES(2, 'ii');
  INSERT INTO main.t1 VALUES(3, 'iii');
................................................................................
  SELECT * FROM t2
} {
  1   "UPDATE t2 SET a=b+c"          {5 1 4     14 5 9   11  6 5}
  2   "UPDATE t2 SET a=b, b=a"       {1 5 4     5 14 9    6 11 5}
  3   "UPDATE t2 SET a=c||c, c=NULL" {44 5 {}  99 14 {}  55 11 {}}
}

# EVIDENCE-OF: R-12619-24112 The optional conflict-clause allows the
# user to nominate a specific constraint conflict resolution algorithm
# to use during this one UPDATE command.

#
do_execsql_test e_update-1.8.0 {
  DELETE FROM t3;
  INSERT INTO t3 VALUES(1, 'one');
  INSERT INTO t3 VALUES(2, 'two');
  INSERT INTO t3 VALUES(3, 'three');
  INSERT INTO t3 VALUES(4, 'four');
................................................................................
}



# EVIDENCE-OF: R-12123-54095 The table-name specified as part of an
# UPDATE statement within a trigger body must be unqualified.
#
# EVIDENCE-OF: R-09690-36749 In other words, the database-name. prefix
# on the table name of the UPDATE is not allowed within triggers.
#
do_update_tests e_update-2.1 -error {
  qualified table names are not allowed on INSERT, UPDATE, and DELETE statements within triggers
} {
  1 {
      CREATE TRIGGER tr1 AFTER INSERT ON t1 BEGIN
        UPDATE main.t2 SET a=1, b=2, c=3;

  1  "UPDATE t1 SET b = 'roman' ; SELECT * FROM t1"
     {1 roman  2 roman  3 roman}

  2  "UPDATE t1 SET a = 'greek' ; SELECT * FROM t1"
     {greek roman  greek roman  greek roman}
}

# EVIDENCE-OF: R-58095-46013 Otherwise, the UPDATE affects only those

# rows for which the WHERE clause boolean expression is true.
#
do_execsql_test e_update-1.3.0 {
  DELETE FROM main.t1;
  INSERT INTO main.t1 VALUES(NULL, '');
  INSERT INTO main.t1 VALUES(1, 'i');
  INSERT INTO main.t1 VALUES(2, 'ii');
  INSERT INTO main.t1 VALUES(3, 'iii');
................................................................................
  SELECT * FROM t2
} {
  1   "UPDATE t2 SET a=b+c"          {5 1 4     14 5 9   11  6 5}
  2   "UPDATE t2 SET a=b, b=a"       {1 5 4     5 14 9    6 11 5}
  3   "UPDATE t2 SET a=c||c, c=NULL" {44 5 {}  99 14 {}  55 11 {}}
}

# EVIDENCE-OF: R-28518-13457 The optional "OR action" conflict clause
# that follows the UPDATE keyword allows the user to nominate a specific
# constraint conflict resolution algorithm to use during this one UPDATE
# command.
#
do_execsql_test e_update-1.8.0 {
  DELETE FROM t3;
  INSERT INTO t3 VALUES(1, 'one');
  INSERT INTO t3 VALUES(2, 'two');
  INSERT INTO t3 VALUES(3, 'three');
  INSERT INTO t3 VALUES(4, 'four');
................................................................................
}



# EVIDENCE-OF: R-12123-54095 The table-name specified as part of an
# UPDATE statement within a trigger body must be unqualified.
#
# EVIDENCE-OF: R-43190-62442 In other words, the schema-name. prefix on
# the table name of the UPDATE is not allowed within triggers.
#
do_update_tests e_update-2.1 -error {
  qualified table names are not allowed on INSERT, UPDATE, and DELETE statements within triggers
} {
  1 {
      CREATE TRIGGER tr1 AFTER INSERT ON t1 BEGIN
        UPDATE main.t2 SET a=1, b=2, c=3;

#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.
#
# This file tests the PRAGMA foreign_key_check command.
#
# EVIDENCE-OF: R-01427-50262 PRAGMA database.foreign_key_check; PRAGMA
# database.foreign_key_check(table-name);
#
# EVIDENCE-OF: R-23918-17301 The foreign_key_check pragma checks the
# database, or the table called "table-name", for foreign key
# constraints that are violated and returns one row of output for each
# violation.

set testdir [file dirname $argv0]

#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.
#
# This file tests the PRAGMA foreign_key_check command.
#
# EVIDENCE-OF: R-15402-03103 PRAGMA schema.foreign_key_check; PRAGMA
# schema.foreign_key_check(table-name);
#
# EVIDENCE-OF: R-23918-17301 The foreign_key_check pragma checks the
# database, or the table called "table-name", for foreign key
# constraints that are violated and returns one row of output for each
# violation.

set testdir [file dirname $argv0]

}

# Parser tests. Test that an INDEXED BY or NOT INDEX clause can be 
# attached to a table in the FROM clause, but not to a sub-select or
# SQL view. Also test that specifying an index that does not exist or
# is attached to a different table is detected as an error.
#
# EVIDENCE-OF: R-63761-48810 -- syntax diagram qualified-table-name
# 
# EVIDENCE-OF: R-58230-57098 The "INDEXED BY index-name" phrase
# specifies that the named index must be used in order to look up values
# on the preceding table.
#
do_test indexedby-2.1 {
  execsql { SELECT * FROM t1 NOT INDEXED WHERE a = 'one' AND b = 'two'}
................................................................................
# query planner to use a particular named index on a DELETE, SELECT, or
# UPDATE statement.
#
# Test that "INDEXED BY" can be used in a DELETE statement.
# 
do_execsql_test indexedby-7.1 {
  EXPLAIN QUERY PLAN DELETE FROM t1 WHERE a = 5 
} {0 0 0 {SEARCH TABLE t1 USING COVERING INDEX i1 (a=?)}}
do_execsql_test indexedby-7.2 {
  EXPLAIN QUERY PLAN DELETE FROM t1 NOT INDEXED WHERE a = 5 
} {0 0 0 {SCAN TABLE t1}}
do_execsql_test indexedby-7.3 {
  EXPLAIN QUERY PLAN DELETE FROM t1 INDEXED BY i1 WHERE a = 5 
} {0 0 0 {SEARCH TABLE t1 USING COVERING INDEX i1 (a=?)}}
do_execsql_test indexedby-7.4 {
  EXPLAIN QUERY PLAN DELETE FROM t1 INDEXED BY i1 WHERE a = 5 AND b = 10
} {0 0 0 {SEARCH TABLE t1 USING INDEX i1 (a=?)}}
do_execsql_test indexedby-7.5 {
  EXPLAIN QUERY PLAN DELETE FROM t1 INDEXED BY i2 WHERE a = 5 AND b = 10
} {0 0 0 {SEARCH TABLE t1 USING INDEX i2 (b=?)}}
do_test indexedby-7.6 {

}

# Parser tests. Test that an INDEXED BY or NOT INDEX clause can be 
# attached to a table in the FROM clause, but not to a sub-select or
# SQL view. Also test that specifying an index that does not exist or
# is attached to a different table is detected as an error.
#
# EVIDENCE-OF: R-07004-11522 -- syntax diagram qualified-table-name
# 
# EVIDENCE-OF: R-58230-57098 The "INDEXED BY index-name" phrase
# specifies that the named index must be used in order to look up values
# on the preceding table.
#
do_test indexedby-2.1 {
  execsql { SELECT * FROM t1 NOT INDEXED WHERE a = 'one' AND b = 'two'}
................................................................................
# query planner to use a particular named index on a DELETE, SELECT, or
# UPDATE statement.
#
# Test that "INDEXED BY" can be used in a DELETE statement.
# 
do_execsql_test indexedby-7.1 {
  EXPLAIN QUERY PLAN DELETE FROM t1 WHERE a = 5 
} {0 0 0 {SEARCH TABLE t1 USING INDEX i1 (a=?)}}
do_execsql_test indexedby-7.2 {
  EXPLAIN QUERY PLAN DELETE FROM t1 NOT INDEXED WHERE a = 5 
} {0 0 0 {SCAN TABLE t1}}
do_execsql_test indexedby-7.3 {
  EXPLAIN QUERY PLAN DELETE FROM t1 INDEXED BY i1 WHERE a = 5 
} {0 0 0 {SEARCH TABLE t1 USING INDEX i1 (a=?)}}
do_execsql_test indexedby-7.4 {
  EXPLAIN QUERY PLAN DELETE FROM t1 INDEXED BY i1 WHERE a = 5 AND b = 10
} {0 0 0 {SEARCH TABLE t1 USING INDEX i1 (a=?)}}
do_execsql_test indexedby-7.5 {
  EXPLAIN QUERY PLAN DELETE FROM t1 INDEXED BY i2 WHERE a = 5 AND b = 10
} {0 0 0 {SEARCH TABLE t1 USING INDEX i2 (b=?)}}
do_test indexedby-7.6 {

# SQLite library.
#

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

load_static_extension db json
do_execsql_test json1-1.1 {
  SELECT json_array(1,2.5,null,'hello');
} {[1,2.5,null,"hello"]}












do_execsql_test json1-1.2 {
  SELECT hex(json_array('String "\ Test'));
} {5B22537472696E67205C225C5C2054657374225D}
do_catchsql_test json1-1.3 {
  SELECT json_array(1,2,x'abcd',3);
} {1 {JSON cannot hold BLOB values}}
do_execsql_test json1-1.4 {
................................................................................
  SELECT json_object('a',1,'b',x'abcd');
} {1 {JSON cannot hold BLOB values}}

do_execsql_test json1-3.1 {
  SELECT json_replace('{"a":1,"b":2}','$.a','[3,4,5]');
} {{{"a":"[3,4,5]","b":2}}}
do_execsql_test json1-3.2 {
  SELECT json_replace('{"a":1,"b":2}','$$.a','[3,4,5]');
} {{{"a":[3,4,5],"b":2}}}
do_execsql_test json1-3.3 {
  SELECT json_type(json_set('{"a":1,"b":2}','$.b','{"x":3,"y":4}'),'$.b');
} {text}
do_execsql_test json1-3.4 {
  SELECT json_type(json_set('{"a":1,"b":2}','$$.b','{"x":3,"y":4}'),'$.b');
} {object}

# Per rfc7159, any JSON value is allowed at the top level, and whitespace
# is permitting before and/or after that value.
#
do_execsql_test json1-4.1 {
  CREATE TABLE j1(x);

# SQLite library.
#

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

load_static_extension db json
do_execsql_test json1-1.1.00 {
  SELECT json_array(1,2.5,null,'hello');
} {[1,2.5,null,"hello"]}
do_execsql_test json1-1.1.01 {
  SELECT json_array(1,'{"abc":2.5,"def":null,"ghi":hello}',99);
  -- the second term goes in as a string:
} {[1,"{\\"abc\\":2.5,\\"def\\":null,\\"ghi\\":hello}",99]}
do_execsql_test json1-1.1.02 {
  SELECT json_array(1,json('{"abc":2.5,"def":null,"ghi":"hello"}'),99);
  -- the second term goes in as JSON
} {[1,{"abc":2.5,"def":null,"ghi":"hello"},99]}
do_execsql_test json1-1.1.03 {
  SELECT json_array(1,json_object('abc',2.5,'def',null,'ghi','hello'),99);
  -- the second term goes in as JSON
} {[1,{"abc":2.5,"def":null,"ghi":"hello"},99]}
do_execsql_test json1-1.2 {
  SELECT hex(json_array('String "\ Test'));
} {5B22537472696E67205C225C5C2054657374225D}
do_catchsql_test json1-1.3 {
  SELECT json_array(1,2,x'abcd',3);
} {1 {JSON cannot hold BLOB values}}
do_execsql_test json1-1.4 {
................................................................................
  SELECT json_object('a',1,'b',x'abcd');
} {1 {JSON cannot hold BLOB values}}

do_execsql_test json1-3.1 {
  SELECT json_replace('{"a":1,"b":2}','$.a','[3,4,5]');
} {{{"a":"[3,4,5]","b":2}}}
do_execsql_test json1-3.2 {
  SELECT json_replace('{"a":1,"b":2}','$.a',json('[3,4,5]'));
} {{{"a":[3,4,5],"b":2}}}
do_execsql_test json1-3.3 {
  SELECT json_type(json_set('{"a":1,"b":2}','$.b','{"x":3,"y":4}'),'$.b');
} {text}
do_execsql_test json1-3.4 {
  SELECT json_type(json_set('{"a":1,"b":2}','$.b',json('{"x":3,"y":4}')),'$.b');
} {object}

# Per rfc7159, any JSON value is allowed at the top level, and whitespace
# is permitting before and/or after that value.
#
do_execsql_test json1-4.1 {
  CREATE TABLE j1(x);

# 2015-08-12
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements tests for JSON SQL functions extension to the
# SQLite library.
#
# This file contains tests automatically generated from the json1
# documentation.
#

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

load_static_extension db json
do_execsql_test json102-100 {
  SELECT json_object('ex','[52,3.14159]');
} {{{"ex":"[52,3.14159]"}}}
do_execsql_test json102-110 {
  SELECT json_object('ex',json('[52,3.14159]'));
} {{{"ex":[52,3.14159]}}}
do_execsql_test json102-120 {
  SELECT json_object('ex',json_array(52,3.14159));
} {{{"ex":[52,3.14159]}}}
do_execsql_test json102-130 {
  SELECT json(' { "this" : "is", "a": [ "test" ] } ');
} {{{"this":"is","a":["test"]}}}
do_execsql_test json102-140 {
  SELECT json_array(1,2,'3',4);
} {{[1,2,"3",4]}}
do_execsql_test json102-150 {
  SELECT json_array('[1,2]');
} {{["[1,2]"]}}
do_execsql_test json102-160 {
  SELECT json_array(json_array(1,2));
} {{[[1,2]]}}
do_execsql_test json102-170 {
  SELECT json_array(1,null,'3','[4,5]','{"six":7.7}');
} {{[1,null,"3","[4,5]","{\"six\":7.7}"]}}
do_execsql_test json102-180 {
  SELECT json_array(1,null,'3',json('[4,5]'),json('{"six":7.7}'));
} {{[1,null,"3",[4,5],{"six":7.7}]}}
do_execsql_test json102-190 {
  SELECT json_array_length('[1,2,3,4]');
} {{4}}
do_execsql_test json102-200 {
  SELECT json_array_length('[1,2,3,4]', '$');
} {{4}}
do_execsql_test json102-210 {
  SELECT json_array_length('[1,2,3,4]', '$[2]');
} {{0}}
do_execsql_test json102-220 {
  SELECT json_array_length('{"one":[1,2,3]}');
} {{0}}
do_execsql_test json102-230 {
  SELECT json_array_length('{"one":[1,2,3]}', '$.one');
} {{3}}
do_execsql_test json102-240 {
  SELECT json_array_length('{"one":[1,2,3]}', '$.two');
} {{}}
do_execsql_test json102-250 {
  SELECT json_extract('{"a":2,"c":[4,5,{"f":7}]}', '$');
} {{{"a":2,"c":[4,5,{"f":7}]}}}
do_execsql_test json102-260 {
  SELECT json_extract('{"a":2,"c":[4,5,{"f":7}]}', '$.c');
} {{[4,5,{"f":7}]}}
do_execsql_test json102-270 {
  SELECT json_extract('{"a":2,"c":[4,5,{"f":7}]}', '$.c[2]');
} {{{"f":7}}}
do_execsql_test json102-280 {
  SELECT json_extract('{"a":2,"c":[4,5,{"f":7}]}', '$.c[2].f');
} {{7}}
do_execsql_test json102-290 {
  SELECT json_extract('{"a":2,"c":[4,5],"f":7}','$.c','$.a');
} {{[[4,5],2]}}
do_execsql_test json102-300 {
  SELECT json_extract('{"a":2,"c":[4,5,{"f":7}]}', '$.x');
} {{}}
do_execsql_test json102-310 {
  SELECT json_extract('{"a":2,"c":[4,5,{"f":7}]}', '$.x', '$.a');
} {{[null,2]}}
do_execsql_test json102-320 {
  SELECT json_insert('{"a":2,"c":4}', '$.a', 99);
} {{{"a":2,"c":4}}}
do_execsql_test json102-330 {
  SELECT json_insert('{"a":2,"c":4}', '$.e', 99);
} {{{"a":2,"c":4,"e":99}}}
do_execsql_test json102-340 {
  SELECT json_replace('{"a":2,"c":4}', '$.a', 99);
} {{{"a":99,"c":4}}}
do_execsql_test json102-350 {
  SELECT json_replace('{"a":2,"c":4}', '$.e', 99);
} {{{"a":2,"c":4}}}
do_execsql_test json102-360 {
  SELECT json_set('{"a":2,"c":4}', '$.a', 99);
} {{{"a":99,"c":4}}}
do_execsql_test json102-370 {
  SELECT json_set('{"a":2,"c":4}', '$.e', 99);
} {{{"a":2,"c":4,"e":99}}}
do_execsql_test json102-380 {
  SELECT json_set('{"a":2,"c":4}', '$.c', '[97,96]');
} {{{"a":2,"c":"[97,96]"}}}
do_execsql_test json102-390 {
  SELECT json_set('{"a":2,"c":4}', '$.c', json('[97,96]'));
} {{{"a":2,"c":[97,96]}}}
do_execsql_test json102-400 {
  SELECT json_set('{"a":2,"c":4}', '$.c', json_array(97,96));
} {{{"a":2,"c":[97,96]}}}
do_execsql_test json102-410 {
  SELECT json_object('a',2,'c',4);
} {{{"a":2,"c":4}}}
do_execsql_test json102-420 {
  SELECT json_object('a',2,'c','{e:5}');
} {{{"a":2,"c":"{e:5}"}}}
do_execsql_test json102-430 {
  SELECT json_object('a',2,'c',json_object('e',5));
} {{{"a":2,"c":{"e":5}}}}
do_execsql_test json102-440 {
  SELECT json_remove('[0,1,2,3,4]','$[2]');
} {{[0,1,3,4]}}
do_execsql_test json102-450 {
  SELECT json_remove('[0,1,2,3,4]','$[2]','$[0]');
} {{[1,3,4]}}
do_execsql_test json102-460 {
  SELECT json_remove('[0,1,2,3,4]','$[0]','$[2]');
} {{[1,2,4]}}
do_execsql_test json102-470 {
  SELECT json_remove('{"x":25,"y":42}');
} {{{"x":25,"y":42}}}
do_execsql_test json102-480 {
  SELECT json_remove('{"x":25,"y":42}','$.z');
} {{{"x":25,"y":42}}}
do_execsql_test json102-490 {
  SELECT json_remove('{"x":25,"y":42}','$.y');
} {{{"x":25}}}
do_execsql_test json102-500 {
  SELECT json_remove('{"x":25,"y":42}','$');
} {{}}
do_execsql_test json102-510 {
  SELECT json_type('{"a":[2,3.5,true,false,null,"x"]}');
} {{object}}
do_execsql_test json102-520 {
  SELECT json_type('{"a":[2,3.5,true,false,null,"x"]}','$');
} {{object}}
do_execsql_test json102-530 {
  SELECT json_type('{"a":[2,3.5,true,false,null,"x"]}','$.a');
} {{array}}
do_execsql_test json102-540 {
  SELECT json_type('{"a":[2,3.5,true,false,null,"x"]}','$.a[0]');
} {{integer}}
do_execsql_test json102-550 {
  SELECT json_type('{"a":[2,3.5,true,false,null,"x"]}','$.a[1]');
} {{real}}
do_execsql_test json102-560 {
  SELECT json_type('{"a":[2,3.5,true,false,null,"x"]}','$.a[2]');
} {{true}}
do_execsql_test json102-570 {
  SELECT json_type('{"a":[2,3.5,true,false,null,"x"]}','$.a[3]');
} {{false}}
do_execsql_test json102-580 {
  SELECT json_type('{"a":[2,3.5,true,false,null,"x"]}','$.a[4]');
} {{null}}
do_execsql_test json102-590 {
  SELECT json_type('{"a":[2,3.5,true,false,null,"x"]}','$.a[5]');
} {{text}}
do_execsql_test json102-600 {
  SELECT json_type('{"a":[2,3.5,true,false,null,"x"]}','$.a[6]');
} {{}}
do_execsql_test json102-610 {
  SELECT json_valid(char(123)||'"x":35'||char(125));
} {{1}}
do_execsql_test json102-620 {
  SELECT json_valid(char(123)||'"x":35');
} {{0}}

ifcapable vtab {
do_execsql_test json102-1000 {
  CREATE TABLE user(name,phone);
  INSERT INTO user(name,phone) VALUES
     ('Alice','["919-555-2345","804-555-3621"]'),
     ('Bob','["201-555-8872"]'),
     ('Cindy','["704-555-9983"]'),
     ('Dave','["336-555-8421","704-555-4321","803-911-4421"]');
  SELECT DISTINCT user.name
    FROM user, json_each(user.phone)
   WHERE json_each.value LIKE '704-%'
   ORDER BY 1;
} {Cindy Dave}

do_execsql_test json102-1010 {
  UPDATE user
     SET phone=json_extract(phone,'$[0]')
   WHERE json_array_length(phone)<2;
  SELECT name, substr(phone,1,5) FROM user ORDER BY name;
} {Alice {["919} Bob 201-5 Cindy 704-5 Dave {["336}}
do_execsql_test json102-1011 {
  SELECT name FROM user WHERE phone LIKE '704-%'
  UNION
  SELECT user.name
    FROM user, json_each(user.phone)
   WHERE json_valid(user.phone)
     AND json_each.value LIKE '704-%';
} {Cindy Dave}

do_execsql_test json102-1100 {
  CREATE TABLE big(json JSON);
  INSERT INTO big(json) VALUES('{
    "id":123,
    "stuff":[1,2,3,4],
    "partlist":[
       {"uuid":"bb108722-572e-11e5-9320-7f3b63a4ca74"},
       {"uuid":"c690dc14-572e-11e5-95f9-dfc8861fd535"},
       {"subassembly":[
          {"uuid":"6fa5181e-5721-11e5-a04e-57f3d7b32808"}
       ]}
    ]
  }');
  INSERT INTO big(json) VALUES('{
    "id":456,
    "stuff":["hello","world","xyzzy"],
    "partlist":[
       {"uuid":false},
       {"uuid":"c690dc14-572e-11e5-95f9-dfc8861fd535"}
    ]
  }');
} {}
set correct_answer [list \
    1 {$.id} 123 \
    1 {$.stuff[0]} 1 \
    1 {$.stuff[1]} 2 \
    1 {$.stuff[2]} 3 \
    1 {$.stuff[3]} 4 \
    1 {$.partlist[0].uuid} bb108722-572e-11e5-9320-7f3b63a4ca74 \
    1 {$.partlist[1].uuid} c690dc14-572e-11e5-95f9-dfc8861fd535 \
    1 {$.partlist[2].subassembly[0].uuid} 6fa5181e-5721-11e5-a04e-57f3d7b32808 \
    2 {$.id} 456 \
    2 {$.stuff[0]} hello \
    2 {$.stuff[1]} world \
    2 {$.stuff[2]} xyzzy \
    2 {$.partlist[0].uuid} 0 \
    2 {$.partlist[1].uuid} c690dc14-572e-11e5-95f9-dfc8861fd535]
do_execsql_test json102-1110 {
  SELECT big.rowid, fullkey, value
    FROM big, json_tree(big.json)
   WHERE json_tree.type NOT IN ('object','array')
   ORDER BY +big.rowid, +json_tree.id
} $correct_answer
do_execsql_test json102-1120 {
  SELECT big.rowid, fullkey, atom
    FROM big, json_tree(big.json)
   WHERE atom IS NOT NULL
   ORDER BY +big.rowid, +json_tree.id
} $correct_answer

do_execsql_test json102-1130 {
  SELECT DISTINCT json_extract(big.json,'$.id')
    FROM big, json_tree(big.json,'$.partlist')
   WHERE json_tree.key='uuid'
     AND json_tree.value='6fa5181e-5721-11e5-a04e-57f3d7b32808';
} {123}
do_execsql_test json102-1131 {
  SELECT DISTINCT json_extract(big.json,'$.id')
    FROM big, json_tree(big.json,'$')
   WHERE json_tree.key='uuid'
     AND json_tree.value='6fa5181e-5721-11e5-a04e-57f3d7b32808';
} {123}
do_execsql_test json102-1132 {
  SELECT DISTINCT json_extract(big.json,'$.id')
    FROM big, json_tree(big.json)
   WHERE json_tree.key='uuid'
     AND json_tree.value='6fa5181e-5721-11e5-a04e-57f3d7b32808';
} {123}
} ;# end ifcapable vtab

finish_test

# that the "all.test" script does.
#
db close
delete_file test.db test.db-journal
delete_file test3.db test3.db-journal
sqlite3 db test.db; set DB [sqlite3_connection_pointer db]

# EVIDENCE-OF: R-24197-42751 PRAGMA database.cache_size; PRAGMA
# database.cache_size = pages; PRAGMA database.cache_size = -kibibytes;
# Query or change the suggested maximum number of database disk pages
# that SQLite will hold in memory at once per open database file.
#
ifcapable pager_pragmas {
set DFLT_CACHE_SZ [db one {PRAGMA default_cache_size}]
set TEMP_CACHE_SZ [db one {PRAGMA temp.default_cache_size}]
do_test pragma-1.1 {
................................................................................
#
do_test pragma-6.5.1b {
  capture_pragma db out {PRAGMA index_xinfo(t3i1)}
  db eval {SELECT seqno, cid, name FROM out ORDER BY seqno}
} {0 0 a 1 1 b 2 -1 {}}


# EVIDENCE-OF: R-62725-03366 PRAGMA database.index_info(index-name);
# This pragma returns one row for each key column in the named index.
#
# (The first column of output from PRAGMA index_info is...)
# EVIDENCE-OF: R-34186-52914 The rank of the column within the index. (0
# means left-most.)
#
# (The second column of output from PRAGMA index_info is...)
# EVIDENCE-OF: R-65019-08383 The rank of the column within the table
................................................................................
  {1 b {} 0 {} 2} \
  {2 c {} 0 {} 4} \
]
} ;# ifcapable schema_pragmas
# Miscellaneous tests
#
ifcapable schema_pragmas {
# EVIDENCE-OF: R-63500-32024 PRAGMA database.index_list(table-name);
# This pragma returns one row for each index associated with the given
# table.

do_test pragma-7.1.1 {
  # Make sure a pragma knows to read the schema if it needs to
  db close
  sqlite3 db test.db
  capture_pragma db out "PRAGMA index_list(t3)"
  db eval {SELECT name, "origin" FROM out ORDER BY name DESC}
} {t3i1 c sqlite_autoindex_t3_1 u}
................................................................................
} ;# ifcapable bloblit 

ifcapable pager_pragmas {
  db close
  forcedelete test.db
  sqlite3 db test.db
 
  # EVIDENCE-OF: R-13905-26312 PRAGMA database.page_count; Return the
  # total number of pages in the database file.
  #
  do_test pragma-14.1 {
    execsql { pragma auto_vacuum = 0 }
    execsql { pragma page_count; pragma main.page_count }
  } {0 0}

  do_test pragma-14.2 {
................................................................................
    DROP INDEX i2;
    CREATE INDEX i2 ON t1(c,d,b);
  }
  capture_pragma db2 out {PRAGMA index_info(i2)}
  db2 eval {SELECT cid, name, '|' FROM out ORDER BY seqno}
} {2 c | 3 d | 1 b |}

# EVIDENCE-OF: R-44874-46325 PRAGMA database.index_xinfo(index-name);
# This pragma returns information about every column in an index.
#
# EVIDENCE-OF: R-45970-35618 Unlike this index_info pragma, this pragma
# returns information about every column in the index, not just the key
# columns.
#
do_test 23.2b {
  capture_pragma db2 out {PRAGMA index_xinfo(i2)}
................................................................................
do_test 23.2c {
  db2 eval {PRAGMA index_xinfo(i2)}
} {0 2 c 0 BINARY 1 1 3 d 0 BINARY 1 2 1 b 0 BINARY 1 3 -1 {} 0 BINARY 0}
do_test 23.2d {
  db2 eval {PRAGMA index_xinfo(i2x)}
} {0 3 d 0 nocase 1 1 2 c 1 BINARY 1 2 -1 {} 0 BINARY 0}

# EVIDENCE-OF: R-63500-32024 PRAGMA database.index_list(table-name);
# This pragma returns one row for each index associated with the given
# table.
#
# (The first column of output from PRAGMA index_list is...)
# EVIDENCE-OF: R-02753-24748 A sequence number assigned to each index
# for internal tracking purposes.
#
# (The second column of output from PRAGMA index_list is...)
# EVIDENCE-OF: R-35496-03635 The name of the index.

# that the "all.test" script does.
#
db close
delete_file test.db test.db-journal
delete_file test3.db test3.db-journal
sqlite3 db test.db; set DB [sqlite3_connection_pointer db]

# EVIDENCE-OF: R-13861-56665 PRAGMA schema.cache_size; PRAGMA
# schema.cache_size = pages; PRAGMA schema.cache_size = -kibibytes;
# Query or change the suggested maximum number of database disk pages
# that SQLite will hold in memory at once per open database file.
#
ifcapable pager_pragmas {
set DFLT_CACHE_SZ [db one {PRAGMA default_cache_size}]
set TEMP_CACHE_SZ [db one {PRAGMA temp.default_cache_size}]
do_test pragma-1.1 {
................................................................................
#
do_test pragma-6.5.1b {
  capture_pragma db out {PRAGMA index_xinfo(t3i1)}
  db eval {SELECT seqno, cid, name FROM out ORDER BY seqno}
} {0 0 a 1 1 b 2 -1 {}}


# EVIDENCE-OF: R-29448-60346 PRAGMA schema.index_info(index-name); This
# pragma returns one row for each key column in the named index.
#
# (The first column of output from PRAGMA index_info is...)
# EVIDENCE-OF: R-34186-52914 The rank of the column within the index. (0
# means left-most.)
#
# (The second column of output from PRAGMA index_info is...)
# EVIDENCE-OF: R-65019-08383 The rank of the column within the table
................................................................................
  {1 b {} 0 {} 2} \
  {2 c {} 0 {} 4} \
]
} ;# ifcapable schema_pragmas
# Miscellaneous tests
#
ifcapable schema_pragmas {
# EVIDENCE-OF: R-64103-17776 PRAGMA schema.index_list(table-name); This
# pragma returns one row for each index associated with the given table.

#
do_test pragma-7.1.1 {
  # Make sure a pragma knows to read the schema if it needs to
  db close
  sqlite3 db test.db
  capture_pragma db out "PRAGMA index_list(t3)"
  db eval {SELECT name, "origin" FROM out ORDER BY name DESC}
} {t3i1 c sqlite_autoindex_t3_1 u}
................................................................................
} ;# ifcapable bloblit 

ifcapable pager_pragmas {
  db close
  forcedelete test.db
  sqlite3 db test.db
 
  # EVIDENCE-OF: R-15672-33611 PRAGMA schema.page_count; Return the total
  # number of pages in the database file.
  #
  do_test pragma-14.1 {
    execsql { pragma auto_vacuum = 0 }
    execsql { pragma page_count; pragma main.page_count }
  } {0 0}

  do_test pragma-14.2 {
................................................................................
    DROP INDEX i2;
    CREATE INDEX i2 ON t1(c,d,b);
  }
  capture_pragma db2 out {PRAGMA index_info(i2)}
  db2 eval {SELECT cid, name, '|' FROM out ORDER BY seqno}
} {2 c | 3 d | 1 b |}

# EVIDENCE-OF: R-56143-29319 PRAGMA schema.index_xinfo(index-name); This
# pragma returns information about every column in an index.
#
# EVIDENCE-OF: R-45970-35618 Unlike this index_info pragma, this pragma
# returns information about every column in the index, not just the key
# columns.
#
do_test 23.2b {
  capture_pragma db2 out {PRAGMA index_xinfo(i2)}
................................................................................
do_test 23.2c {
  db2 eval {PRAGMA index_xinfo(i2)}
} {0 2 c 0 BINARY 1 1 3 d 0 BINARY 1 2 1 b 0 BINARY 1 3 -1 {} 0 BINARY 0}
do_test 23.2d {
  db2 eval {PRAGMA index_xinfo(i2x)}
} {0 3 d 0 nocase 1 1 2 c 1 BINARY 1 2 -1 {} 0 BINARY 0}

# EVIDENCE-OF: R-64103-17776 PRAGMA schema.index_list(table-name); This
# pragma returns one row for each index associated with the given table.

#
# (The first column of output from PRAGMA index_list is...)
# EVIDENCE-OF: R-02753-24748 A sequence number assigned to each index
# for internal tracking purposes.
#
# (The second column of output from PRAGMA index_list is...)
# EVIDENCE-OF: R-35496-03635 The name of the index.

db close
delete_file test.db test.db-journal
delete_file test3.db test3.db-journal
sqlite3 db test.db; set DB [sqlite3_connection_pointer db]
db eval {PRAGMA auto_vacuum=0}


# EVIDENCE-OF: R-17887-14874 PRAGMA database.freelist_count; Return the
# number of unused pages in the database file.
#
do_test pragma2-1.1 {
  execsql {
    PRAGMA freelist_count;
  }
} {0}

db close
delete_file test.db test.db-journal
delete_file test3.db test3.db-journal
sqlite3 db test.db; set DB [sqlite3_connection_pointer db]
db eval {PRAGMA auto_vacuum=0}


# EVIDENCE-OF: R-11211-21323 PRAGMA schema.freelist_count; Return the
# number of unused pages in the database file.
#
do_test pragma2-1.1 {
  execsql {
    PRAGMA freelist_count;
  }
} {0}

# Output log
#
set LOG [open releasetest-out.txt w]
proc PUTS {args} {
  if {[llength $args]==2} {
    puts [lindex $args 0] [lindex $args 1]
    puts [lindex $args 0] $::LOG [lindex $args 1]
  } else {
    puts [lindex $args 0]
    puts $::LOG [lindex $args 0]
  }
}
puts $LOG "$argv0 $argv"
set tm0 [clock format [clock seconds] -format {%Y-%m-%d %H:%M:%S} -gmt 1]
................................................................................

  set elapsetime [expr {[clock seconds]-$STARTTIME}]
  set hr [expr {$elapsetime/3600}]
  set min [expr {($elapsetime/60)%60}]
  set sec [expr {$elapsetime%60}]
  set etime [format (%02d:%02d:%02d) $hr $min $sec]
  PUTS [string repeat * 79]

  PUTS "$::NERRCASE failures out of $::NTESTCASE tests in $etime"
  if {$::SQLITE_VERSION ne ""} {
    PUTS "SQLite $::SQLITE_VERSION"
  }
}

main $argv

# Output log
#
set LOG [open releasetest-out.txt w]
proc PUTS {args} {
  if {[llength $args]==2} {
    puts [lindex $args 0] [lindex $args 1]
    puts $::LOG [lindex $args 1]
  } else {
    puts [lindex $args 0]
    puts $::LOG [lindex $args 0]
  }
}
puts $LOG "$argv0 $argv"
set tm0 [clock format [clock seconds] -format {%Y-%m-%d %H:%M:%S} -gmt 1]
................................................................................

  set elapsetime [expr {[clock seconds]-$STARTTIME}]
  set hr [expr {$elapsetime/3600}]
  set min [expr {($elapsetime/60)%60}]
  set sec [expr {$elapsetime%60}]
  set etime [format (%02d:%02d:%02d) $hr $min $sec]
  PUTS [string repeat * 79]
  incr ::NERRCASE $::NERR
  PUTS "$::NERRCASE failures out of $::NTESTCASE tests in $etime"
  if {$::SQLITE_VERSION ne ""} {
    PUTS "SQLite $::SQLITE_VERSION"
  }
}

main $argv

# 2015-09-10
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements tests for sqlite3_value_subtype() and
# sqlite3_result_subtype() interfaces.
#

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

do_execsql_test subtype1-100 {
  SELECT test_getsubtype('hello');
} {0}
do_execsql_test subtype1-110 {
  SELECT test_getsubtype(test_setsubtype('hello',123));
} {123}
do_execsql_test subtype1-120 {
  SELECT typeof(test_setsubtype('hello',123));
} {text}
do_execsql_test subtype1-130 {
  SELECT test_setsubtype('hello',123);
} {hello}

finish_test

  SELECT * FROM generate_series() LIMIT 5;
} {0 1 2 3 4}

do_execsql_test tabfunc01-3.1 {
  SELECT DISTINCT value FROM generate_series(1,x), t1 ORDER BY 1;
} {1 2 3}















finish_test

  SELECT * FROM generate_series() LIMIT 5;
} {0 1 2 3 4}

do_execsql_test tabfunc01-3.1 {
  SELECT DISTINCT value FROM generate_series(1,x), t1 ORDER BY 1;
} {1 2 3}

# Eponymous virtual table exists in the "main" schema only
#
do_execsql_test tabfunc01-4.1 {
  SELECT * FROM main.generate_series(1,4)
} {1 2 3 4}
do_catchsql_test tabfunc01-4.2 {
  SELECT * FROM temp.generate_series(1,4)
} {1 {no such table: temp.generate_series}}
do_catchsql_test tabfunc01-4.3 {
  ATTACH ':memory:' AS aux1;
  CREATE TABLE aux1.t1(a,b,c);
  SELECT * FROM aux1.generate_series(1,4)
} {1 {no such table: aux1.generate_series}}

finish_test

  BEGIN;
  CREATE TABLE t1 AS SELECT zeroblob(2e20);
} {1 {string or blob too big}}
do_execsql_test table-18.2 {
  COMMIT;
  PRAGMA integrity_check;
} {ok}














finish_test

  BEGIN;
  CREATE TABLE t1 AS SELECT zeroblob(2e20);
} {1 {string or blob too big}}
do_execsql_test table-18.2 {
  COMMIT;
  PRAGMA integrity_check;
} {ok}

# 2015-09-09
# Ticket [https://www.sqlite.org/src/info/acd12990885d9276]
# "CREATE TABLE ... AS SELECT ... FROM sqlite_master" fails because the row
# in the sqlite_master table for the next table is initially populated
# with a NULL instead of a record created by OP_Record.
#
do_execsql_test table-19.1 {
  CREATE TABLE t19 AS SELECT * FROM sqlite_master;
  SELECT name FROM t19 ORDER BY name;
} {{} savepoint t10 t11 t12 t13 t16 t2 t3 t3\"xyz t4\"abc t7 t8 t9 tablet8 test1 weird}



finish_test

*/
static int axset_compare(const void *a, const void *b){
  struct axset *p1 = (struct axset*)a;
  struct axset *p2 = (struct axset*)b;
  int c;
  c = p2->nAction - p1->nAction;
  if( c==0 ){
    c = p2->iOrder - p1->iOrder;
  }
  assert( c!=0 || p1==p2 );
  return c;
}

/*
** Write text on "out" that describes the rule "rp".
................................................................................
        if( action<0 ) continue;
        acttab_action(pActtab, ap->sp->index, action);
      }
      stp->iNtOfst = acttab_insert(pActtab);
      if( stp->iNtOfst<mnNtOfst ) mnNtOfst = stp->iNtOfst;
      if( stp->iNtOfst>mxNtOfst ) mxNtOfst = stp->iNtOfst;
    }










  }
  free(ax);

  /* Finish rendering the constants now that the action table has
  ** been computed */
  fprintf(out,"#define YYNSTATE             %d\n",lemp->nxstate);  lineno++;
  fprintf(out,"#define YYNRULE              %d\n",lemp->nrule);  lineno++;
  fprintf(out,"#define YY_MAX_SHIFT         %d\n",lemp->nstate-1);  lineno++;
  fprintf(out,"#define YY_MIN_SHIFTREDUCE   %d\n",lemp->nstate); lineno++;
  i = lemp->nstate + lemp->nrule;
  fprintf(out,"#define YY_MAX_SHIFTREDUCE   %d\n", i-1); lineno++;
  fprintf(out,"#define YY_MIN_REDUCE        %d\n", i); lineno++;
  i = lemp->nstate + lemp->nrule*2;
  fprintf(out,"#define YY_MAX_REDUCE        %d\n", i-1); lineno++;
  fprintf(out,"#define YY_ERROR_ACTION      %d\n", i); lineno++;
................................................................................
** is a possible look-ahead.
*/
void CompressTables(struct lemon *lemp)
{
  struct state *stp;
  struct action *ap, *ap2;
  struct rule *rp, *rp2, *rbest;
  int nbest, n, nshift;
  int i;
  int usesWildcard;

  for(i=0; i<lemp->nstate; i++){
    stp = lemp->sorted[i];
    nbest = 0;
    rbest = 0;

*/
static int axset_compare(const void *a, const void *b){
  struct axset *p1 = (struct axset*)a;
  struct axset *p2 = (struct axset*)b;
  int c;
  c = p2->nAction - p1->nAction;
  if( c==0 ){
    c = p1->iOrder - p2->iOrder;
  }
  assert( c!=0 || p1==p2 );
  return c;
}

/*
** Write text on "out" that describes the rule "rp".
................................................................................
        if( action<0 ) continue;
        acttab_action(pActtab, ap->sp->index, action);
      }
      stp->iNtOfst = acttab_insert(pActtab);
      if( stp->iNtOfst<mnNtOfst ) mnNtOfst = stp->iNtOfst;
      if( stp->iNtOfst>mxNtOfst ) mxNtOfst = stp->iNtOfst;
    }
#if 0  /* Uncomment for a trace of how the yy_action[] table fills out */
    { int jj, nn;
      for(jj=nn=0; jj<pActtab->nAction; jj++){
        if( pActtab->aAction[jj].action<0 ) nn++;
      }
      printf("%4d: State %3d %s n: %2d size: %5d freespace: %d\n",
             i, stp->statenum, ax[i].isTkn ? "Token" : "Var  ",
             ax[i].nAction, pActtab->nAction, nn);
    }
#endif
  }
  free(ax);

  /* Finish rendering the constants now that the action table has
  ** been computed */
  fprintf(out,"#define YYNSTATE             %d\n",lemp->nxstate);  lineno++;
  fprintf(out,"#define YYNRULE              %d\n",lemp->nrule);  lineno++;
  fprintf(out,"#define YY_MAX_SHIFT         %d\n",lemp->nxstate-1); lineno++;
  fprintf(out,"#define YY_MIN_SHIFTREDUCE   %d\n",lemp->nstate); lineno++;
  i = lemp->nstate + lemp->nrule;
  fprintf(out,"#define YY_MAX_SHIFTREDUCE   %d\n", i-1); lineno++;
  fprintf(out,"#define YY_MIN_REDUCE        %d\n", i); lineno++;
  i = lemp->nstate + lemp->nrule*2;
  fprintf(out,"#define YY_MAX_REDUCE        %d\n", i-1); lineno++;
  fprintf(out,"#define YY_ERROR_ACTION      %d\n", i); lineno++;
................................................................................
** is a possible look-ahead.
*/
void CompressTables(struct lemon *lemp)
{
  struct state *stp;
  struct action *ap, *ap2;
  struct rule *rp, *rp2, *rbest;
  int nbest, n;
  int i;
  int usesWildcard;

  for(i=0; i<lemp->nstate; i++){
    stp = lemp->sorted[i];
    nbest = 0;
    rbest = 0;

  return 0
}

# Get the name of the database to analyze
#
proc usage {} {
  set argv0 [file rootname [file tail [info nameofexecutable]]]
  puts stderr "Usage: $argv0 \[--pageinfo] \[--stats] database-name"












  exit 1
}
set file_to_analyze {}
set flags(-pageinfo) 0
set flags(-stats) 0
append argv {}
foreach arg $argv {

  return 0
}

# Get the name of the database to analyze
#
proc usage {} {
  set argv0 [file rootname [file tail [info nameofexecutable]]]
  puts stderr "Usage: $argv0 ?--pageinfo? ?--stats? database-filename"
  puts stderr {
Analyze the SQLite3 database file specified by the "database-filename"
argument and output a report detailing size and storage efficiency
information for the database and its constituent tables and indexes.

Options:

   --stats        Output SQL text that creates a new database containing
                  statistics about the database that was analyzed

   --pageinfo     Show how each page of the database-file is used
}
  exit 1
}
set file_to_analyze {}
set flags(-pageinfo) 0
set flags(-stats) 0
append argv {}
foreach arg $argv {