*/
static void fts3MatchinfoFunc(
  sqlite3_context *pContext,      /* SQLite function call context */
  int nVal,                       /* Size of argument array */
  sqlite3_value **apVal           /* Array of arguments */
){
  Fts3Cursor *pCsr;               /* Cursor handle passed through apVal[0] */
  assert( nVal==1 );
  if( SQLITE_OK==fts3FunctionArg(pContext, "matchinfo", apVal[0], &pCsr) ){

    sqlite3Fts3Matchinfo(pContext, pCsr);
  }
}

/*
** This routine implements the xFindFunction method for the FTS3
** virtual table.
*/
................................................................................
  ** module with sqlite.
  */
  if( SQLITE_OK==rc 
   && SQLITE_OK==(rc = sqlite3Fts3InitHashTable(db, pHash, "fts3_tokenizer"))
   && SQLITE_OK==(rc = sqlite3_overload_function(db, "snippet", -1))
   && SQLITE_OK==(rc = sqlite3_overload_function(db, "offsets", 1))
   && SQLITE_OK==(rc = sqlite3_overload_function(db, "matchinfo", 1))

   && SQLITE_OK==(rc = sqlite3_overload_function(db, "optimize", 1))
  ){
    rc = sqlite3_create_module_v2(
        db, "fts3", &fts3Module, (void *)pHash, hashDestroy
    );
    if( rc==SQLITE_OK ){
      rc = sqlite3_create_module_v2(

*/
static void fts3MatchinfoFunc(
  sqlite3_context *pContext,      /* SQLite function call context */
  int nVal,                       /* Size of argument array */
  sqlite3_value **apVal           /* Array of arguments */
){
  Fts3Cursor *pCsr;               /* Cursor handle passed through apVal[0] */
  assert( nVal==1 || nVal==2 );
  if( SQLITE_OK==fts3FunctionArg(pContext, "matchinfo", apVal[0], &pCsr) ){
    const char *zArg = (nVal>1 ? sqlite3_value_text(apVal[1]) : 0);
    sqlite3Fts3Matchinfo(pContext, pCsr, zArg);
  }
}

/*
** This routine implements the xFindFunction method for the FTS3
** virtual table.
*/
................................................................................
  ** module with sqlite.
  */
  if( SQLITE_OK==rc 
   && SQLITE_OK==(rc = sqlite3Fts3InitHashTable(db, pHash, "fts3_tokenizer"))
   && SQLITE_OK==(rc = sqlite3_overload_function(db, "snippet", -1))
   && SQLITE_OK==(rc = sqlite3_overload_function(db, "offsets", 1))
   && SQLITE_OK==(rc = sqlite3_overload_function(db, "matchinfo", 1))
   && SQLITE_OK==(rc = sqlite3_overload_function(db, "matchinfo", 2))
   && SQLITE_OK==(rc = sqlite3_overload_function(db, "optimize", 1))
  ){
    rc = sqlite3_create_module_v2(
        db, "fts3", &fts3Module, (void *)pHash, hashDestroy
    );
    if( rc==SQLITE_OK ){
      rc = sqlite3_create_module_v2(

struct Fts3Cursor {
  sqlite3_vtab_cursor base;       /* Base class used by SQLite core */
  i16 eSearch;                    /* Search strategy (see below) */
  u8 isEof;                       /* True if at End Of Results */
  u8 isRequireSeek;               /* True if must seek pStmt to %_content row */
  sqlite3_stmt *pStmt;            /* Prepared statement in use by the cursor */
  Fts3Expr *pExpr;                /* Parsed MATCH query string */

  Fts3DeferredToken *pDeferred;   /* Deferred search tokens, if any */
  sqlite3_int64 iPrevId;          /* Previous id read from aDoclist */
  char *pNextId;                  /* Pointer into the body of aDoclist */
  char *aDoclist;                 /* List of docids for full-text queries */
  int nDoclist;                   /* Size of buffer at aDoclist */
  int isMatchinfoNeeded;          /* True when aMatchinfo[] needs filling in */
  u32 *aMatchinfo;                /* Information about most recent match */
  int eEvalmode;                  /* An FTS3_EVAL_XX constant */
  int nRowAvg;                    /* Average size of database rows, in pages */





};

#define FTS3_EVAL_FILTER    0
#define FTS3_EVAL_NEXT      1
#define FTS3_EVAL_MATCHINFO 2

/*
................................................................................
int sqlite3Fts3SegReaderCost(Fts3Cursor *, Fts3SegReader *, int *);
int sqlite3Fts3AllSegdirs(Fts3Table*, sqlite3_stmt **);
int sqlite3Fts3MatchinfoDocsizeLocal(Fts3Cursor*, u32*);
int sqlite3Fts3MatchinfoDocsizeGlobal(Fts3Cursor*, u32*);
int sqlite3Fts3ReadLock(Fts3Table *);
int sqlite3Fts3ReadBlock(Fts3Table*, sqlite3_int64, char **, int*);




void sqlite3Fts3FreeDeferredTokens(Fts3Cursor *);
int sqlite3Fts3DeferToken(Fts3Cursor *, Fts3PhraseToken *, int);
int sqlite3Fts3CacheDeferredDoclists(Fts3Cursor *);
void sqlite3Fts3FreeDeferredDoclists(Fts3Cursor *);
char *sqlite3Fts3DeferredDoclist(Fts3DeferredToken *, int *);

void sqlite3Fts3SegmentsClose(Fts3Table *);
................................................................................
int sqlite3Fts3IsIdChar(char);

/* fts3_snippet.c */
void sqlite3Fts3Offsets(sqlite3_context*, Fts3Cursor*);
void sqlite3Fts3Snippet(sqlite3_context *, Fts3Cursor *, const char *,
  const char *, const char *, int, int
);
void sqlite3Fts3Matchinfo(sqlite3_context *, Fts3Cursor *);

/* fts3_expr.c */
int sqlite3Fts3ExprParse(sqlite3_tokenizer *, 
  char **, int, int, const char *, int, Fts3Expr **
);
void sqlite3Fts3ExprFree(Fts3Expr *);
#ifdef SQLITE_TEST
int sqlite3Fts3ExprInitTestInterface(sqlite3 *db);
#endif

#endif /* _FTSINT_H */

struct Fts3Cursor {
  sqlite3_vtab_cursor base;       /* Base class used by SQLite core */
  i16 eSearch;                    /* Search strategy (see below) */
  u8 isEof;                       /* True if at End Of Results */
  u8 isRequireSeek;               /* True if must seek pStmt to %_content row */
  sqlite3_stmt *pStmt;            /* Prepared statement in use by the cursor */
  Fts3Expr *pExpr;                /* Parsed MATCH query string */
  int nPhrase;                    /* Number of matchable phrases in query */
  Fts3DeferredToken *pDeferred;   /* Deferred search tokens, if any */
  sqlite3_int64 iPrevId;          /* Previous id read from aDoclist */
  char *pNextId;                  /* Pointer into the body of aDoclist */
  char *aDoclist;                 /* List of docids for full-text queries */
  int nDoclist;                   /* Size of buffer at aDoclist */


  int eEvalmode;                  /* An FTS3_EVAL_XX constant */
  int nRowAvg;                    /* Average size of database rows, in pages */

  int isMatchinfoNeeded;          /* True when aMatchinfo[] needs filling in */
  u32 *aMatchinfo;                /* Information about most recent match */
  int nMatchinfo;                 /* Number of elements in aMatchinfo[] */
  char *zMatchinfo;               /* Matchinfo specification */
};

#define FTS3_EVAL_FILTER    0
#define FTS3_EVAL_NEXT      1
#define FTS3_EVAL_MATCHINFO 2

/*
................................................................................
int sqlite3Fts3SegReaderCost(Fts3Cursor *, Fts3SegReader *, int *);
int sqlite3Fts3AllSegdirs(Fts3Table*, sqlite3_stmt **);
int sqlite3Fts3MatchinfoDocsizeLocal(Fts3Cursor*, u32*);
int sqlite3Fts3MatchinfoDocsizeGlobal(Fts3Cursor*, u32*);
int sqlite3Fts3ReadLock(Fts3Table *);
int sqlite3Fts3ReadBlock(Fts3Table*, sqlite3_int64, char **, int*);

int sqlite3Fts3SelectDoctotal(Fts3Table *, sqlite3_stmt **);
int sqlite3Fts3SelectDocsize(Fts3Table *, sqlite3_int64, sqlite3_stmt **);

void sqlite3Fts3FreeDeferredTokens(Fts3Cursor *);
int sqlite3Fts3DeferToken(Fts3Cursor *, Fts3PhraseToken *, int);
int sqlite3Fts3CacheDeferredDoclists(Fts3Cursor *);
void sqlite3Fts3FreeDeferredDoclists(Fts3Cursor *);
char *sqlite3Fts3DeferredDoclist(Fts3DeferredToken *, int *);

void sqlite3Fts3SegmentsClose(Fts3Table *);
................................................................................
int sqlite3Fts3IsIdChar(char);

/* fts3_snippet.c */
void sqlite3Fts3Offsets(sqlite3_context*, Fts3Cursor*);
void sqlite3Fts3Snippet(sqlite3_context *, Fts3Cursor *, const char *,
  const char *, const char *, int, int
);
void sqlite3Fts3Matchinfo(sqlite3_context *, Fts3Cursor *, const char *);

/* fts3_expr.c */
int sqlite3Fts3ExprParse(sqlite3_tokenizer *, 
  char **, int, int, const char *, int, Fts3Expr **
);
void sqlite3Fts3ExprFree(Fts3Expr *);
#ifdef SQLITE_TEST
int sqlite3Fts3ExprInitTestInterface(sqlite3 *db);
#endif

#endif /* _FTSINT_H */

#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)

#include "fts3Int.h"
#include <string.h>
#include <assert.h>


















/*
** Used as an fts3ExprIterate() context when loading phrase doclists to
** Fts3Expr.aDoclist[]/nDoclist.
*/
typedef struct LoadDoclistCtx LoadDoclistCtx;
struct LoadDoclistCtx {
................................................................................
** This type is used as an fts3ExprIterate() context object while 
** accumulating the data returned by the matchinfo() function.
*/
typedef struct MatchInfo MatchInfo;
struct MatchInfo {
  Fts3Cursor *pCursor;            /* FTS3 Cursor */
  int nCol;                       /* Number of columns in table */


  u32 *aMatchinfo;                /* Pre-allocated buffer */
};



/*
** The snippet() and offsets() functions both return text values. An instance
................................................................................
  }
  pCsr++;
  *pp = pCsr;
}

/*
** fts3ExprIterate() callback used to collect the "global" matchinfo stats
** for a single query. The "global" stats are those elements of the matchinfo



** array that are constant for all rows returned by the current query.













*/
static int fts3ExprGlobalMatchinfoCb(
  Fts3Expr *pExpr,                /* Phrase expression node */
  int iPhrase,                    /* Phrase number (numbered from zero) */
  void *pCtx                      /* Pointer to MatchInfo structure */
){
  MatchInfo *p = (MatchInfo *)pCtx;
  Fts3Cursor *pCsr = p->pCursor;
  char *pIter;
  char *pEnd;
  char *pFree = 0;
  const int iStart = 2 + (iPhrase * p->nCol * 3) + 1;

  assert( pExpr->isLoaded );
  assert( pExpr->eType==FTSQUERY_PHRASE );

  if( pCsr->pDeferred ){
    Fts3Phrase *pPhrase = pExpr->pPhrase;
    int ii;
................................................................................
    if( ii<pPhrase->nToken ){
      int nFree = 0;
      int rc = sqlite3Fts3ExprLoadFtDoclist(pCsr, pExpr, &pFree, &nFree);
      if( rc!=SQLITE_OK ) return rc;
      pIter = pFree;
      pEnd = &pFree[nFree];
    }else{
      int nDoc = p->aMatchinfo[2 + 3*p->nCol*p->aMatchinfo[0]];
      for(ii=0; ii<p->nCol; ii++){
        p->aMatchinfo[iStart + ii*3] = nDoc;
        p->aMatchinfo[iStart + ii*3 + 1] = nDoc;
      }
      return SQLITE_OK;
    }
  }else{
    pIter = pExpr->aDoclist;
    pEnd = &pExpr->aDoclist[pExpr->nDoclist];
  }

  /* Fill in the global hit count matrix row for this phrase. */
  while( pIter<pEnd ){
    while( *pIter++ & 0x80 );      /* Skip past docid. */
    fts3LoadColumnlistCounts(&pIter, &p->aMatchinfo[iStart], 1);
  }

  sqlite3_free(pFree);
  return SQLITE_OK;
}

/*
** fts3ExprIterate() callback used to collect the "local" matchinfo stats
** for a single query. The "local" stats are those elements of the matchinfo
** array that are different for each row returned by the query.
*/
static int fts3ExprLocalMatchinfoCb(
  Fts3Expr *pExpr,                /* Phrase expression node */
  int iPhrase,                    /* Phrase number */
  void *pCtx                      /* Pointer to MatchInfo structure */
){
  MatchInfo *p = (MatchInfo *)pCtx;

  if( pExpr->aDoclist ){
    char *pCsr;
    int iStart = 2 + (iPhrase * p->nCol * 3);
    int i;

    for(i=0; i<p->nCol; i++) p->aMatchinfo[iStart+i*3] = 0;

    pCsr = sqlite3Fts3FindPositions(pExpr, p->pCursor->iPrevId, -1);
    if( pCsr ){
      fts3LoadColumnlistCounts(&pCsr, &p->aMatchinfo[iStart], 0);
    }
  }

  return SQLITE_OK;
}






























































































































































/*
** Populate pCsr->aMatchinfo[] with data for the current row. The 
** 'matchinfo' data is an array of 32-bit unsigned integers (C type u32).
*/
static int fts3GetMatchinfo(Fts3Cursor *pCsr){



  MatchInfo sInfo;
  Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;
  int rc = SQLITE_OK;



  sInfo.pCursor = pCsr;
  sInfo.nCol = pTab->nColumn;





  if( pCsr->aMatchinfo==0 ){





    /* If Fts3Cursor.aMatchinfo[] is NULL, then this is the first time the
    ** matchinfo function has been called for this query. In this case 
    ** allocate the array used to accumulate the matchinfo data and
    ** initialize those elements that are constant for every row.
    */
    int nPhrase;                  /* Number of phrases */

    int nMatchinfo;               /* Number of u32 elements in match-info */



    /* Load doclists for each phrase in the query. */
    rc = fts3ExprLoadDoclists(pCsr, &nPhrase, 0);
    if( rc!=SQLITE_OK ){
      return rc;

    }
    nMatchinfo = 2 + 3*sInfo.nCol*nPhrase;
    if( pTab->bHasDocsize ){
      nMatchinfo += 1 + 2*pTab->nColumn;


    }



    sInfo.aMatchinfo = (u32 *)sqlite3_malloc(sizeof(u32)*nMatchinfo);
    if( !sInfo.aMatchinfo ){ 
      return SQLITE_NOMEM;
    }



    memset(sInfo.aMatchinfo, 0, sizeof(u32)*nMatchinfo);

    /* First element of match-info is the number of phrases in the query */
    sInfo.aMatchinfo[0] = nPhrase;
    sInfo.aMatchinfo[1] = sInfo.nCol;
    if( pTab->bHasDocsize ){
      int ofst = 2 + 3*sInfo.aMatchinfo[0]*sInfo.aMatchinfo[1];
      rc = sqlite3Fts3MatchinfoDocsizeGlobal(pCsr, &sInfo.aMatchinfo[ofst]);
    }
    (void)fts3ExprIterate(pCsr->pExpr, fts3ExprGlobalMatchinfoCb,(void*)&sInfo);
    pCsr->aMatchinfo = sInfo.aMatchinfo;
    pCsr->isMatchinfoNeeded = 1;

  }

  sInfo.aMatchinfo = pCsr->aMatchinfo;

  if( rc==SQLITE_OK && pCsr->isMatchinfoNeeded ){
    (void)fts3ExprIterate(pCsr->pExpr, fts3ExprLocalMatchinfoCb, (void*)&sInfo);
    if( pTab->bHasDocsize ){
      int ofst = 2 + 3*sInfo.aMatchinfo[0]*sInfo.aMatchinfo[1];
      rc = sqlite3Fts3MatchinfoDocsizeLocal(pCsr, &sInfo.aMatchinfo[ofst]);
    }
    pCsr->isMatchinfoNeeded = 0;
  }

  return SQLITE_OK;
}

/*
** Implementation of snippet() function.
*/
void sqlite3Fts3Snippet(
  sqlite3_context *pCtx,          /* SQLite function call context */
................................................................................
  }
  return;
}

/*
** Implementation of matchinfo() function.
*/
void sqlite3Fts3Matchinfo(sqlite3_context *pContext, Fts3Cursor *pCsr){





  int rc;

















  if( !pCsr->pExpr ){
    sqlite3_result_blob(pContext, "", 0, SQLITE_STATIC);
    return;
  }


  rc = fts3GetMatchinfo(pCsr);
  sqlite3Fts3SegmentsClose((Fts3Table *)pCsr->base.pVtab );

  if( rc!=SQLITE_OK ){
    sqlite3_result_error_code(pContext, rc);
  }else{
    Fts3Table *pTab = (Fts3Table*)pCsr->base.pVtab;
    int n = sizeof(u32)*(2+pCsr->aMatchinfo[0]*pCsr->aMatchinfo[1]*3);
    if( pTab->bHasDocsize ){
      n += sizeof(u32)*(1 + 2*pTab->nColumn);
    }
    sqlite3_result_blob(pContext, pCsr->aMatchinfo, n, SQLITE_TRANSIENT);
  }
}

#endif

#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)

#include "fts3Int.h"
#include <string.h>
#include <assert.h>

/*
** Characters that may appear in the second argument to matchinfo().
*/
#define FTS3_MATCHINFO_NPHRASE   'p'        /* 1 value */
#define FTS3_MATCHINFO_NCOL      'c'        /* 1 value */
#define FTS3_MATCHINFO_NDOC      'n'        /* 1 value */
#define FTS3_MATCHINFO_AVGLENGTH 'a'        /* nCol values */
#define FTS3_MATCHINFO_LENGTH    'l'        /* nCol values */
#define FTS3_MATCHINFO_LCS       's'        /* nCol values */
#define FTS3_MATCHINFO_HITS      'x'        /* 3*nCol*nPhrase values */

/*
** The default value for the second argument to matchinfo(). 
*/
#define FTS3_MATCHINFO_DEFAULT   "pcx"


/*
** Used as an fts3ExprIterate() context when loading phrase doclists to
** Fts3Expr.aDoclist[]/nDoclist.
*/
typedef struct LoadDoclistCtx LoadDoclistCtx;
struct LoadDoclistCtx {
................................................................................
** This type is used as an fts3ExprIterate() context object while 
** accumulating the data returned by the matchinfo() function.
*/
typedef struct MatchInfo MatchInfo;
struct MatchInfo {
  Fts3Cursor *pCursor;            /* FTS3 Cursor */
  int nCol;                       /* Number of columns in table */
  int nPhrase;                    /* Number of matchable phrases in query */
  sqlite3_int64 nDoc;             /* Number of docs in database */
  u32 *aMatchinfo;                /* Pre-allocated buffer */
};



/*
** The snippet() and offsets() functions both return text values. An instance
................................................................................
  }
  pCsr++;
  *pp = pCsr;
}

/*
** fts3ExprIterate() callback used to collect the "global" matchinfo stats
** for a single query. 
**
** fts3ExprIterate() callback to load the 'global' elements of a
** FTS3_MATCHINFO_HITS matchinfo array. The global stats are those elements 
** of the matchinfo array that are constant for all rows returned by the 
** current query.
**
** Argument pCtx is actually a pointer to a struct of type MatchInfo. This
** function populates Matchinfo.aMatchinfo[] as follows:
**
**   for(iCol=0; iCol<nCol; iCol++){
**     aMatchinfo[3*iPhrase*nCol + 3*iCol + 1] = X;
**     aMatchinfo[3*iPhrase*nCol + 3*iCol + 2] = Y;
**   }
**
** where X is the number of matches for phrase iPhrase is column iCol of all
** rows of the table. Y is the number of rows for which column iCol contains
** at least one instance of phrase iPhrase.
*/
static int fts3ExprGlobalHitsCb(
  Fts3Expr *pExpr,                /* Phrase expression node */
  int iPhrase,                    /* Phrase number (numbered from zero) */
  void *pCtx                      /* Pointer to MatchInfo structure */
){
  MatchInfo *p = (MatchInfo *)pCtx;
  Fts3Cursor *pCsr = p->pCursor;
  char *pIter;
  char *pEnd;
  char *pFree = 0;
  u32 *aOut = &p->aMatchinfo[3*iPhrase*p->nCol];

  assert( pExpr->isLoaded );
  assert( pExpr->eType==FTSQUERY_PHRASE );

  if( pCsr->pDeferred ){
    Fts3Phrase *pPhrase = pExpr->pPhrase;
    int ii;
................................................................................
    if( ii<pPhrase->nToken ){
      int nFree = 0;
      int rc = sqlite3Fts3ExprLoadFtDoclist(pCsr, pExpr, &pFree, &nFree);
      if( rc!=SQLITE_OK ) return rc;
      pIter = pFree;
      pEnd = &pFree[nFree];
    }else{
      int iCol;                   /* Column index */
      for(iCol=0; iCol<p->nCol; iCol++){
        aOut[iCol*3 + 1] = (u32)p->nDoc;
        aOut[iCol*3 + 2] = (u32)p->nDoc;
      }
      return SQLITE_OK;
    }
  }else{
    pIter = pExpr->aDoclist;
    pEnd = &pExpr->aDoclist[pExpr->nDoclist];
  }

  /* Fill in the global hit count matrix row for this phrase. */
  while( pIter<pEnd ){
    while( *pIter++ & 0x80 );      /* Skip past docid. */
    fts3LoadColumnlistCounts(&pIter, &aOut[1], 1);
  }

  sqlite3_free(pFree);
  return SQLITE_OK;
}

/*
** fts3ExprIterate() callback used to collect the "local" part of the
** FTS3_MATCHINFO_HITS array. The local stats are those elements of the 
** array that are different for each row returned by the query.
*/
static int fts3ExprLocalHitsCb(
  Fts3Expr *pExpr,                /* Phrase expression node */
  int iPhrase,                    /* Phrase number */
  void *pCtx                      /* Pointer to MatchInfo structure */
){
  MatchInfo *p = (MatchInfo *)pCtx;

  if( pExpr->aDoclist ){
    char *pCsr;
    int iStart = iPhrase * p->nCol * 3;
    int i;

    for(i=0; i<p->nCol; i++) p->aMatchinfo[iStart+i*3] = 0;

    pCsr = sqlite3Fts3FindPositions(pExpr, p->pCursor->iPrevId, -1);
    if( pCsr ){
      fts3LoadColumnlistCounts(&pCsr, &p->aMatchinfo[iStart], 0);
    }
  }

  return SQLITE_OK;
}

static int fts3MatchinfoCheck(
  Fts3Table *pTab, 
  char cArg,
  char **pzErr
){
  if( cArg==FTS3_MATCHINFO_NPHRASE
   || cArg==FTS3_MATCHINFO_NCOL
   || cArg==FTS3_MATCHINFO_NDOC && pTab->bHasStat
   || cArg==FTS3_MATCHINFO_AVGLENGTH && pTab->bHasStat
   || cArg==FTS3_MATCHINFO_LENGTH && pTab->bHasDocsize
   || cArg==FTS3_MATCHINFO_LCS
   || cArg==FTS3_MATCHINFO_HITS
  ){
    return SQLITE_OK;
  }
  *pzErr = sqlite3_mprintf("unrecognized matchinfo request: %c", cArg);
  return SQLITE_ERROR;
}

static int fts3MatchinfoSize(MatchInfo *pInfo, char cArg){
  int nVal;                       /* Number of integers output by cArg */

  switch( cArg ){
    case FTS3_MATCHINFO_NDOC:
    case FTS3_MATCHINFO_NPHRASE: 
    case FTS3_MATCHINFO_NCOL: 
      nVal = 1;
      break;

    case FTS3_MATCHINFO_AVGLENGTH:
    case FTS3_MATCHINFO_LENGTH:
    case FTS3_MATCHINFO_LCS:
      nVal = pInfo->nCol;
      break;

    case FTS3_MATCHINFO_HITS:
      nVal = pInfo->nCol * pInfo->nPhrase * 3;
      break;
  }

  return nVal;
}

static int fts3MatchinfoSelectDoctotal(
  Fts3Table *pTab,
  sqlite3_stmt **ppStmt,
  sqlite3_int64 *pnDoc,
  const char **paLen
){
  sqlite3_stmt *pStmt;
  const char *a;
  sqlite3_int64 nDoc;

  if( !*ppStmt ){
    int rc = sqlite3Fts3SelectDoctotal(pTab, ppStmt);
    if( rc!=SQLITE_OK ) return rc;
  }
  pStmt = *ppStmt;

  a = sqlite3_column_blob(pStmt, 0);
  a += sqlite3Fts3GetVarint(a, &nDoc);
  *pnDoc = (u32)nDoc;

  if( paLen ) *paLen = a;
  return SQLITE_OK;
}
  

static int fts3MatchinfoValues(
  Fts3Cursor *pCsr,               /* FTS3 cursor object */
  int bGlobal,                    /* True to grab the global stats */
  MatchInfo *pInfo,               /* Matchinfo context object */
  const char *zArg                /* Matchinfo format string */
){
  int rc = SQLITE_OK;
  int i;
  Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;

  sqlite3_stmt *pSelect = 0;

  for(i=0; zArg[i]; i++){

    switch( zArg[i] ){
      case FTS3_MATCHINFO_NPHRASE: 
        if( bGlobal ) pInfo->aMatchinfo[0] = pInfo->nPhrase;
        break;

      case FTS3_MATCHINFO_NCOL: 
        if( bGlobal ) pInfo->aMatchinfo[0] = pInfo->nCol;
        break;
        
      case FTS3_MATCHINFO_NDOC:
        if( bGlobal ){
          sqlite3_int64 nDoc;
          rc = fts3MatchinfoSelectDoctotal(pTab, &pSelect, &nDoc, 0);
          pInfo->aMatchinfo[0] = (u32)nDoc;
        }
        break;

      case FTS3_MATCHINFO_AVGLENGTH: 
        if( bGlobal ){
          sqlite3_int64 nDoc;     /* Number of rows in table */
          const char *a;          /* Aggregate column length array */

          rc = fts3MatchinfoSelectDoctotal(pTab, &pSelect, &nDoc, &a);
          if( rc==SQLITE_OK ){
            int iCol;
            for(iCol=0; iCol<pInfo->nCol; iCol++){
              sqlite3_int64 nToken;
              a += sqlite3Fts3GetVarint(a, &nToken);
              pInfo->aMatchinfo[iCol] = ((u32)(nToken&0xffffffff)+nDoc/2)/nDoc;
            }
          }
        }
        break;

      case FTS3_MATCHINFO_LENGTH: {
        sqlite3_stmt *pSelectDocsize = 0;
        rc = sqlite3Fts3SelectDocsize(pTab, pCsr->iPrevId, &pSelectDocsize);
        if( rc==SQLITE_OK ){
          int iCol;
          const char *a = sqlite3_column_blob(pSelectDocsize, 0);
          for(iCol=0; iCol<pInfo->nCol; iCol++){
            sqlite3_int64 nToken;
            a += sqlite3Fts3GetVarint(a, &nToken);
            pInfo->aMatchinfo[iCol] = (u32)nToken;
          }
        }
        sqlite3_reset(pSelectDocsize);
        break;
      }

      case FTS3_MATCHINFO_HITS: {
        Fts3Expr *pExpr = pCsr->pExpr;
        if( bGlobal ){
          if( pCsr->pDeferred ){
            rc = fts3MatchinfoSelectDoctotal(pTab, &pSelect, &pInfo->nDoc, 0);
          }
          (void)fts3ExprIterate(pExpr, fts3ExprGlobalHitsCb,(void*)pInfo);
        }
        (void)fts3ExprIterate(pExpr, fts3ExprLocalHitsCb,(void*)pInfo);
        break;
      }


      default: 
        assert( zArg[i]==FTS3_MATCHINFO_LCS );
    }

    pInfo->aMatchinfo += fts3MatchinfoSize(pInfo, zArg[i]);
  }

  sqlite3_reset(pSelect);
  return rc;
}


/*
** Populate pCsr->aMatchinfo[] with data for the current row. The 
** 'matchinfo' data is an array of 32-bit unsigned integers (C type u32).
*/
static int fts3GetMatchinfo(
  Fts3Cursor *pCsr,               /* FTS3 Cursor object */
  const char *zArg                /* Second argument to matchinfo() function */
){
  MatchInfo sInfo;
  Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;
  int rc = SQLITE_OK;
  int bGlobal = 0;                /* Collect 'global' stats as well as local */

  memset(&sInfo, 0, sizeof(MatchInfo));
  sInfo.pCursor = pCsr;
  sInfo.nCol = pTab->nColumn;

  /* If there is cached matchinfo() data, but the format string for the 
  ** cache does not match the format string for this request, discard 
  ** the cached data. */
  if( pCsr->zMatchinfo && strcmp(pCsr->zMatchinfo, zArg) ){
    assert( pCsr->aMatchinfo );
    sqlite3_free(pCsr->aMatchinfo);
    pCsr->zMatchinfo = 0;
    pCsr->aMatchinfo = 0;
  }

  /* If Fts3Cursor.aMatchinfo[] is NULL, then this is the first time the
  ** matchinfo function has been called for this query. In this case 
  ** allocate the array used to accumulate the matchinfo data and
  ** initialize those elements that are constant for every row.
  */

  if( pCsr->aMatchinfo==0 ){
    int nMatchinfo = 0;           /* Number of u32 elements in match-info */
    int nArg;                     /* Bytes in zArg */
    int i;                        /* Used to iterate through zArg */

    /* Load doclists for each phrase in the query. */
    rc = fts3ExprLoadDoclists(pCsr, &pCsr->nPhrase, 0);
    if( rc!=SQLITE_OK ) return rc;

    sInfo.nPhrase = pCsr->nPhrase;




    for(i=0; zArg[i]; i++){
      nMatchinfo += fts3MatchinfoSize(&sInfo, zArg[i]);
    }

    /* Allocate space for Fts3Cursor.aMatchinfo[] and Fts3Cursor.zMatchinfo. */
    nArg = strlen(zArg);
    pCsr->aMatchinfo = (u32 *)sqlite3_malloc(sizeof(u32)*nMatchinfo + nArg + 1);

    if( !pCsr->aMatchinfo ) return SQLITE_NOMEM;

    pCsr->zMatchinfo = (char *)&pCsr->aMatchinfo[nMatchinfo];
    pCsr->nMatchinfo = nMatchinfo;
    memcpy(pCsr->zMatchinfo, zArg, nArg+1);
    memset(pCsr->aMatchinfo, 0, sizeof(u32)*nMatchinfo);










    pCsr->isMatchinfoNeeded = 1;
    bGlobal = 1;
  }

  sInfo.aMatchinfo = pCsr->aMatchinfo;
  sInfo.nPhrase = pCsr->nPhrase;
  if( rc==SQLITE_OK && pCsr->isMatchinfoNeeded ){

    rc = fts3MatchinfoValues(pCsr, bGlobal, &sInfo, zArg);



    pCsr->isMatchinfoNeeded = 0;
  }

  return rc;
}

/*
** Implementation of snippet() function.
*/
void sqlite3Fts3Snippet(
  sqlite3_context *pCtx,          /* SQLite function call context */
................................................................................
  }
  return;
}

/*
** Implementation of matchinfo() function.
*/
void sqlite3Fts3Matchinfo(
  sqlite3_context *pContext,      /* Function call context */
  Fts3Cursor *pCsr,               /* FTS3 table cursor */
  const char *zArg                /* Second arg to matchinfo() function */
){
  Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;
  int rc;
  int i;
  const char *zFormat;

  if( zArg ){
    for(i=0; zArg[i]; i++){
      char *zErr = 0;
      if( fts3MatchinfoCheck(pTab, zArg[i], &zErr) ){
        sqlite3_result_error(pContext, zErr, -1);
        sqlite3_free(zErr);
        return;
      }
    }
    zFormat = zArg;
  }else{
    zFormat = FTS3_MATCHINFO_DEFAULT;
  }

  if( !pCsr->pExpr ){
    sqlite3_result_blob(pContext, "", 0, SQLITE_STATIC);
    return;
  }

  /* Retrieve matchinfo() data. */
  rc = fts3GetMatchinfo(pCsr, zFormat);
  sqlite3Fts3SegmentsClose(pTab);

  if( rc!=SQLITE_OK ){
    sqlite3_result_error_code(pContext, rc);
  }else{
    int n = pCsr->nMatchinfo * sizeof(u32);




    sqlite3_result_blob(pContext, pCsr->aMatchinfo, n, SQLITE_TRANSIENT);
  }
}

#endif

    for(i=0; rc==SQLITE_OK && i<nParam; i++){
      rc = sqlite3_bind_value(pStmt, i+1, apVal[i]);
    }
  }
  *pp = pStmt;
  return rc;
}














































/*
** Similar to fts3SqlStmt(). Except, after binding the parameters in
** array apVal[] to the SQL statement identified by eStmt, the statement
** is executed.
**
** Returns SQLITE_OK if the statement is successfully executed, or an

    for(i=0; rc==SQLITE_OK && i<nParam; i++){
      rc = sqlite3_bind_value(pStmt, i+1, apVal[i]);
    }
  }
  *pp = pStmt;
  return rc;
}

static int fts3SelectDocsize(
  Fts3Table *pTab,                /* FTS3 table handle */
  int eStmt,                      /* Either SQL_SELECT_DOCSIZE or DOCTOTAL */
  sqlite3_int64 iDocid,           /* Docid to bind for SQL_SELECT_DOCSIZE */
  sqlite3_stmt **ppStmt           /* OUT: Statement handle */
){
  sqlite3_stmt *pStmt = 0;        /* Statement requested from fts3SqlStmt() */
  int rc;                         /* Return code */

  assert( eStmt==SQL_SELECT_DOCSIZE || eStmt==SQL_SELECT_DOCTOTAL );

  rc = fts3SqlStmt(pTab, eStmt, &pStmt, 0);
  if( rc==SQLITE_OK ){
    if( eStmt==SQL_SELECT_DOCSIZE ){
      sqlite3_bind_int64(pStmt, 1, iDocid);
    }
    rc = sqlite3_step(pStmt);
    if( rc!=SQLITE_ROW ){
      rc = sqlite3_reset(pStmt);
      if( rc==SQLITE_OK ) rc = SQLITE_CORRUPT;
      pStmt = 0;
    }else{
      rc = SQLITE_OK;
    }
  }

  *ppStmt = pStmt;
  return rc;
}

int sqlite3Fts3SelectDoctotal(
  Fts3Table *pTab,                /* Fts3 table handle */
  sqlite3_stmt **ppStmt           /* OUT: Statement handle */
){
  return fts3SelectDocsize(pTab, SQL_SELECT_DOCTOTAL, 0, ppStmt);
}

int sqlite3Fts3SelectDocsize(
  Fts3Table *pTab,                /* Fts3 table handle */
  sqlite3_int64 iDocid,           /* Docid to read size data for */
  sqlite3_stmt **ppStmt           /* OUT: Statement handle */
){
  return fts3SelectDocsize(pTab, SQL_SELECT_DOCSIZE, iDocid, ppStmt);
}

/*
** Similar to fts3SqlStmt(). Except, after binding the parameters in
** array apVal[] to the SQL statement identified by eStmt, the statement
** is executed.
**
** Returns SQLITE_OK if the statement is successfully executed, or an

} {2}

do_execsql_test 1.2.1 {
  SELECT content FROM t1 WHERE t1 MATCH 'f (e NEAR/2 a)';
} {{a b c d e f a x y}}

do_execsql_test 1.2.2 {
  SELECT snippet(t1, '[', ']'), offsets(t1), mit(matchinfo(t1))
  FROM t1 WHERE t1 MATCH 'f (e NEAR/2 a)';
} [list                              \
   {a b c d [e] [f] [a] x y}         \
   {0 1 8 1 0 0 10 1 0 2 12 1}       \
   [list 3 1   1 1 1   1 8 8   1 8 8   8 5001 9]
]

do_execsql_test 1.2.3 {
  SELECT snippet(t1, '[', ']'), offsets(t1), mit(matchinfo(t1))
  FROM t1 WHERE t1 MATCH 'f (e NEAR/3 a)';
} [list                                 \
   {[a] b c d [e] [f] [a] x y}          \
   {0 2 0 1 0 1 8 1 0 0 10 1 0 2 12 1}  \
   [list 3 1   1 1 1   1 8 8   2 8 8   8 5001 9]
]

................................................................................
  2 { INSERT INTO t2(t2) VALUES('optimize') }
  3 { UPDATE t2_segments SET block = zeroblob(length(block)) 
      WHERE length(block)>10000;
  }
} {
  execsql $sql
  do_execsql_test 2.2.$tn {
    SELECT mit(matchinfo(t2)) FROM t2 WHERE t2 MATCH 'a b';
  } [list                                          \
    [list 2 1  1 54 54  1 3 3  54 372 7]        \
    [list 2 1  1 54 54  1 3 3  54 372 7]        \
  ]
}

do_execsql_test 2.3.1 {
................................................................................
  2 { INSERT INTO t3(t3) VALUES('optimize') }
  3 { UPDATE t3_segments SET block = zeroblob(length(block)) 
      WHERE length(block)>10000;
  }
} {
  execsql $sql
  do_execsql_test 2.4.$tn {
    SELECT docid, mit(matchinfo(t3)) FROM t3 WHERE t3 MATCH '"a b c"';
  } {1 {1 1 1 4 4 11 912 6} 3 {1 1 1 4 4 11 912 6}}
}


finish_test

} {2}

do_execsql_test 1.2.1 {
  SELECT content FROM t1 WHERE t1 MATCH 'f (e NEAR/2 a)';
} {{a b c d e f a x y}}

do_execsql_test 1.2.2 {
  SELECT snippet(t1, '[', ']'), offsets(t1), mit(matchinfo(t1, 'pcxnal'))
  FROM t1 WHERE t1 MATCH 'f (e NEAR/2 a)';
} [list                              \
   {a b c d [e] [f] [a] x y}         \
   {0 1 8 1 0 0 10 1 0 2 12 1}       \
   [list 3 1   1 1 1   1 8 8   1 8 8   8 5001 9]
]

do_execsql_test 1.2.3 {
  SELECT snippet(t1, '[', ']'), offsets(t1), mit(matchinfo(t1, 'pcxnal'))
  FROM t1 WHERE t1 MATCH 'f (e NEAR/3 a)';
} [list                                 \
   {[a] b c d [e] [f] [a] x y}          \
   {0 2 0 1 0 1 8 1 0 0 10 1 0 2 12 1}  \
   [list 3 1   1 1 1   1 8 8   2 8 8   8 5001 9]
]

................................................................................
  2 { INSERT INTO t2(t2) VALUES('optimize') }
  3 { UPDATE t2_segments SET block = zeroblob(length(block)) 
      WHERE length(block)>10000;
  }
} {
  execsql $sql
  do_execsql_test 2.2.$tn {
    SELECT mit(matchinfo(t2, 'pcxnal')) FROM t2 WHERE t2 MATCH 'a b';
  } [list                                          \
    [list 2 1  1 54 54  1 3 3  54 372 7]        \
    [list 2 1  1 54 54  1 3 3  54 372 7]        \
  ]
}

do_execsql_test 2.3.1 {
................................................................................
  2 { INSERT INTO t3(t3) VALUES('optimize') }
  3 { UPDATE t3_segments SET block = zeroblob(length(block)) 
      WHERE length(block)>10000;
  }
} {
  execsql $sql
  do_execsql_test 2.4.$tn {
    SELECT docid, mit(matchinfo(t3, 'pcxnal')) FROM t3 WHERE t3 MATCH '"a b c"';
  } {1 {1 1 1 4 4 11 912 6} 3 {1 1 1 4 4 11 912 6}}
}


finish_test

  INSERT INTO t1(content) VALUES('I wandered lonely as a cloud');
  INSERT INTO t1(content) VALUES('That floats on high o''er vales and hills,');
  INSERT INTO t1(content) VALUES('When all at once I saw a crowd,');
  INSERT INTO t1(content) VALUES('A host, of golden daffodils,');
  SELECT mit(matchinfo(t1)) FROM t1 WHERE t1 MATCH 'I';
} {{1 1 1 2 2} {1 1 1 2 2}}

# Now create an FTS4 table that does not specify matchinfo=fts3. The 
# %_docsize table is created in this case and the array of integers returned
# by matchinfo() includes the extra data.
#
do_execsql_test 1.2 {
  CREATE VIRTUAL TABLE t2 USING fts4;
  INSERT INTO t2 SELECT * FROM t1;
  SELECT mit(matchinfo(t2)) FROM t2 WHERE t2 MATCH 'I';
} {{1 1 1 2 2 4 7 6} {1 1 1 2 2 4 7 8}}

# Test some syntax-error handling.
#
do_catchsql_test 2.0 {
  CREATE VIRTUAL TABLE x1 USING fts4(matchinfo=fs3);
} {1 {unrecognized matchinfo: fs3}}
do_catchsql_test 2.1 {

  INSERT INTO t1(content) VALUES('I wandered lonely as a cloud');
  INSERT INTO t1(content) VALUES('That floats on high o''er vales and hills,');
  INSERT INTO t1(content) VALUES('When all at once I saw a crowd,');
  INSERT INTO t1(content) VALUES('A host, of golden daffodils,');
  SELECT mit(matchinfo(t1)) FROM t1 WHERE t1 MATCH 'I';
} {{1 1 1 2 2} {1 1 1 2 2}}

# Now create an FTS4 table that does not specify matchinfo=fts3.


#
do_execsql_test 1.2 {
  CREATE VIRTUAL TABLE t2 USING fts4;
  INSERT INTO t2 SELECT * FROM t1;
  SELECT mit(matchinfo(t2)) FROM t2 WHERE t2 MATCH 'I';
} {{1 1 1 2 2} {1 1 1 2 2}}

# Test some syntax-error handling.
#
do_catchsql_test 2.0 {
  CREATE VIRTUAL TABLE x1 USING fts4(matchinfo=fs3);
} {1 {unrecognized matchinfo: fs3}}
do_catchsql_test 2.1 {

  CREATE VIRTUAL TABLE t2 USING FTS4;
  INSERT INTO t2 VALUES('it was the first time in history');
}
do_select_tests 5.2 -errorformat {
  wrong number of arguments to function %s()
} {
  1 "SELECT matchinfo() FROM t2 WHERE t2 MATCH 'history'"       matchinfo
  2 "SELECT matchinfo(t2, t2) FROM t2 WHERE t2 MATCH 'history'" matchinfo

  3 "SELECT snippet(t2, 1, 2, 3, 4, 5, 6) FROM t2 WHERE t2 MATCH 'history'" 
    snippet
}
do_select_tests 5.3 -errorformat {
  illegal first argument to %s
} {
  1 "SELECT matchinfo(content) FROM t2 WHERE t2 MATCH 'history'" matchinfo
................................................................................
  illegal first argument to %s
} {
  1 "SELECT matchinfo(content) FROM t2 WHERE t2 MATCH 'history'" matchinfo
  2 "SELECT offsets(content) FROM t2 WHERE t2 MATCH 'history'"   offsets
  3 "SELECT snippet(content) FROM t2 WHERE t2 MATCH 'history'"   snippet
  4 "SELECT optimize(content) FROM t2 WHERE t2 MATCH 'history'"  optimize
}




do_execsql_test 5.5 { DROP TABLE t2 }


# Test the snippet() function with 1 to 6 arguments.
# 
do_execsql_test 6.1 {
  CREATE VIRTUAL TABLE t3 USING FTS4(a, b);
  INSERT INTO t3 VALUES('no gestures', 'another intriguing discovery by observing the hand gestures (called beats) people make while speaking. Research has shown that such gestures do more than add visual emphasis to our words (many people gesture while they''re on the telephone, for example); it seems they actually help our brains find words');
}

  CREATE VIRTUAL TABLE t2 USING FTS4;
  INSERT INTO t2 VALUES('it was the first time in history');
}
do_select_tests 5.2 -errorformat {
  wrong number of arguments to function %s()
} {
  1 "SELECT matchinfo() FROM t2 WHERE t2 MATCH 'history'"       matchinfo


  3 "SELECT snippet(t2, 1, 2, 3, 4, 5, 6) FROM t2 WHERE t2 MATCH 'history'" 
    snippet
}
do_select_tests 5.3 -errorformat {
  illegal first argument to %s
} {
  1 "SELECT matchinfo(content) FROM t2 WHERE t2 MATCH 'history'" matchinfo
................................................................................
  illegal first argument to %s
} {
  1 "SELECT matchinfo(content) FROM t2 WHERE t2 MATCH 'history'" matchinfo
  2 "SELECT offsets(content) FROM t2 WHERE t2 MATCH 'history'"   offsets
  3 "SELECT snippet(content) FROM t2 WHERE t2 MATCH 'history'"   snippet
  4 "SELECT optimize(content) FROM t2 WHERE t2 MATCH 'history'"  optimize
}
do_catchsql_test 5.5.1 {
  SELECT matchinfo(t2, 'abc') FROM t2 WHERE t2 MATCH 'history'
} {1 {unrecognized matchinfo request: b}}

do_execsql_test 5.5 { DROP TABLE t2 }


# Test the snippet() function with 1 to 6 arguments.
# 
do_execsql_test 6.1 {
  CREATE VIRTUAL TABLE t3 USING FTS4(a, b);
  INSERT INTO t3 VALUES('no gestures', 'another intriguing discovery by observing the hand gestures (called beats) people make while speaking. Research has shown that such gestures do more than add visual emphasis to our words (many people gesture while they''re on the telephone, for example); it seems they actually help our brains find words');
}