SQLite

static int fts3CloseMethod(sqlite3_vtab_cursor *pCursor){
  Fts3Cursor *pCsr = (Fts3Cursor *)pCursor;
  assert( ((Fts3Table *)pCsr->base.pVtab)->pSegments==0 );
  sqlite3_finalize(pCsr->pStmt);
  sqlite3Fts3ExprFree(pCsr->pExpr);
  sqlite3Fts3FreeDeferredTokens(pCsr);
  sqlite3_free(pCsr->aDoclist);
  sqlite3_free(pCsr->aMatchinfo);
  sqlite3Fts3MIBufferFree(pCsr->pMIBuffer);
  assert( ((Fts3Table *)pCsr->base.pVtab)->pSegments==0 );
  sqlite3_free(pCsr);
  return SQLITE_OK;
}

/*
** If pCsr->pStmt has not been prepared (i.e. if pCsr->pStmt==0), then

  if( idxNum & FTS3_HAVE_DOCID_GE ) pDocidGe = apVal[iIdx++];
  if( idxNum & FTS3_HAVE_DOCID_LE ) pDocidLe = apVal[iIdx++];
  assert( iIdx==nVal );

  /* In case the cursor has been used before, clear it now. */
  sqlite3_finalize(pCsr->pStmt);
  sqlite3_free(pCsr->aDoclist);
  sqlite3_free(pCsr->aMatchinfo);
  sqlite3Fts3MIBufferFree(pCsr->pMIBuffer);
  sqlite3Fts3ExprFree(pCsr->pExpr);
  memset(&pCursor[1], 0, sizeof(Fts3Cursor)-sizeof(sqlite3_vtab_cursor));

  /* Set the lower and upper bounds on docids to return */
  pCsr->iMinDocid = fts3DocidRange(pDocidGe, SMALLEST_INT64);
  pCsr->iMaxDocid = fts3DocidRange(pDocidLe, LARGEST_INT64);

typedef struct Fts3Doclist Fts3Doclist;
typedef struct Fts3SegFilter Fts3SegFilter;
typedef struct Fts3DeferredToken Fts3DeferredToken;
typedef struct Fts3SegReader Fts3SegReader;
typedef struct Fts3MultiSegReader Fts3MultiSegReader;

typedef struct MatchinfoBuffer MatchinfoBuffer;

/*
** A connection to a fulltext index is an instance of the following
** structure. The xCreate and xConnect methods create an instance
** of this structure and xDestroy and xDisconnect free that instance.
** All other methods receive a pointer to the structure as one of their
** arguments.
*/

  u8 bDesc;                       /* True to sort in descending order */
  int eEvalmode;                  /* An FTS3_EVAL_XX constant */
  int nRowAvg;                    /* Average size of database rows, in pages */
  sqlite3_int64 nDoc;             /* Documents in table */
  i64 iMinDocid;                  /* Minimum docid to return */
  i64 iMaxDocid;                  /* Maximum docid to return */
  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 */
  MatchinfoBuffer *pMIBuffer;     /* Buffer for matchinfo data */
};

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

/*

  /* The following are used by the fts3_eval.c module. */
  sqlite3_int64 iDocid;      /* Current docid */
  u8 bEof;                   /* True this expression is at EOF already */
  u8 bStart;                 /* True if iDocid is valid */
  u8 bDeferred;              /* True if this expression is entirely deferred */

  /* The following are used by the fts3_snippet.c module. */
  int iPhrase;               /* Index of this phrase in matchinfo() results */
  u32 *aMI;
  u32 *aMI;                  /* See above */
};

/*
** Candidate values for Fts3Query.eType. Note that the order of the first
** four values is in order of precedence when parsing expressions. For 
** example, the following:
**

/* 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 *);
void sqlite3Fts3MIBufferFree(MatchinfoBuffer *p);

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

#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 */
#define FTS3_MATCHINFO_LHITS     'y'        /* nCol*nPhrase values */
#define FTS3_MATCHINFO_LHITS_BM  'b'        /* nCol*nPhrase values */

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

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

/*
** An instance of this structure is used to manage a pair of buffers, each
** (nElem * sizeof(u32)) bytes in size. See the MatchinfoBuffer code below
** for details.
*/
struct MatchinfoBuffer {
  u8 aRef[3];
  int nElem;
  int bGlobal;                    /* Set if global data is loaded */
  char *zMatchinfo;
  u32 aMatchinfo[0];
};


/*
** The snippet() and offsets() functions both return text values. An instance
** of the following structure is used to accumulate those values while the
** functions are running. See fts3StringAppend() for details.
*/
typedef struct StrBuffer StrBuffer;
struct StrBuffer {
  char *z;                        /* Pointer to buffer containing string */
  int n;                          /* Length of z in bytes (excl. nul-term) */
  int nAlloc;                     /* Allocated size of buffer z in bytes */
};


/*************************************************************************
** Start of MatchinfoBuffer code.
*/

/*
** Allocate a two-slot MatchinfoBuffer object.
*/
static MatchinfoBuffer *fts3MIBufferNew(int nElem, const char *zMatchinfo){
  MatchinfoBuffer *pRet;
  int nByte = sizeof(u32) * (2*nElem + 2) + sizeof(MatchinfoBuffer);
  int nStr = strlen(zMatchinfo);

  pRet = sqlite3_malloc(nByte + nStr+1);
  if( pRet ){
    memset(pRet, 0, nByte);
    pRet->aMatchinfo[0] = (u8*)(&pRet->aMatchinfo[1]) - (u8*)pRet;
    pRet->aMatchinfo[1+nElem] = pRet->aMatchinfo[0] + sizeof(u32)*(nElem+1);
    pRet->nElem = nElem;
    pRet->zMatchinfo = ((char*)pRet) + nByte;
    memcpy(pRet->zMatchinfo, zMatchinfo, nStr+1);
    pRet->aRef[0] = 1;
  }

  return pRet;
}

static void fts3MIBufferFree(void *p){
  MatchinfoBuffer *pBuf = (MatchinfoBuffer*)((u8*)p - ((u32*)p)[-1]);

  assert( (u32*)p==&pBuf->aMatchinfo[1] 
       || (u32*)p==&pBuf->aMatchinfo[pBuf->nElem+2] 
  );
  if( (u32*)p==&pBuf->aMatchinfo[1] ){
    pBuf->aRef[1] = 0;
  }else{
    pBuf->aRef[2] = 0;
  }

  if( pBuf->aRef[0]==0 && pBuf->aRef[1]==0 && pBuf->aRef[2]==0 ){
    sqlite3_free(pBuf);
  }
}

static void (*fts3MIBufferAlloc(MatchinfoBuffer *p, u32 **paOut))(void*){
  void (*xRet)(void*) = 0;
  u32 *aOut = 0;

  if( p->aRef[1]==0 ){
    p->aRef[1] = 1;
    aOut = &p->aMatchinfo[1];
    xRet = fts3MIBufferFree;
  }
  else if( p->aRef[2]==0 ){
    p->aRef[2] = 1;
    aOut = &p->aMatchinfo[p->nElem+2];
    xRet = fts3MIBufferFree;
  }else{
    aOut = (u32*)sqlite3_malloc(p->nElem * sizeof(u32));
    if( aOut ){
      xRet = sqlite3_free;
      if( p->bGlobal ) memcpy(aOut, &p->aMatchinfo[1], p->nElem*sizeof(u32));
    }
  }

  *paOut = aOut;
  return xRet;
}

static void fts3MIBufferSetGlobal(MatchinfoBuffer *p){
  p->bGlobal = 1;
  memcpy(&p->aMatchinfo[2+p->nElem], &p->aMatchinfo[1], p->nElem*sizeof(u32));
}

/*
** Free a MatchinfoBuffer object allocated using fts3MIBufferNew()
*/
void sqlite3Fts3MIBufferFree(MatchinfoBuffer *p){
  if( p ){
    assert( p->aRef[0]==1 );
    p->aRef[0] = 0;
    if( p->aRef[0]==0 && p->aRef[1]==0 && p->aRef[2]==0 ){
      sqlite3_free(p);
    }
  }
}

/* 
** End of MatchinfoBuffer code.
*************************************************************************/


/*
** This function is used to help iterate through a position-list. A position
** list is a list of unique integers, sorted from smallest to largest. Each
** element of the list is represented by an FTS3 varint that takes the value
** of the difference between the current element and the previous one plus
** two. For example, to store the position-list:

static int fts3ExprIterate2(
  Fts3Expr *pExpr,                /* Expression to iterate phrases of */
  int *piPhrase,                  /* Pointer to phrase counter */
  int (*x)(Fts3Expr*,int,void*),  /* Callback function to invoke for phrases */
  void *pCtx                      /* Second argument to pass to callback */
){
  int rc;                         /* Return code */
  int eType = pExpr->eType;       /* Type of expression node pExpr */
  int eType = pExpr->eType;     /* Type of expression node pExpr */

  if( eType!=FTSQUERY_PHRASE ){
    assert( pExpr->pLeft && pExpr->pRight );
    rc = fts3ExprIterate2(pExpr->pLeft, piPhrase, x, pCtx);
    if( rc==SQLITE_OK && eType!=FTSQUERY_NOT ){
      rc = fts3ExprIterate2(pExpr->pRight, piPhrase, x, pCtx);
    }

  Fts3Expr *pExpr,                /* Expression to iterate phrases of */
  int (*x)(Fts3Expr*,int,void*),  /* Callback function to invoke for phrases */
  void *pCtx                      /* Second argument to pass to callback */
){
  int iPhrase = 0;                /* Variable used as the phrase counter */
  return fts3ExprIterate2(pExpr, &iPhrase, x, pCtx);
}


/*
** This is an fts3ExprIterate() callback used while loading the doclists
** for each phrase into Fts3Expr.aDoclist[]/nDoclist. See also
** fts3ExprLoadDoclists().
*/
static int fts3ExprLoadDoclistsCb(Fts3Expr *pExpr, int iPhrase, void *ctx){

  if( pnPhrase ) *pnPhrase = sCtx.nPhrase;
  if( pnToken ) *pnToken = sCtx.nToken;
  return rc;
}

static int fts3ExprPhraseCountCb(Fts3Expr *pExpr, int iPhrase, void *ctx){
  (*(int *)ctx)++;
  UNUSED_PARAMETER(pExpr);
  UNUSED_PARAMETER(iPhrase);
  pExpr->iPhrase = iPhrase;
  return SQLITE_OK;
}
static int fts3ExprPhraseCount(Fts3Expr *pExpr){
  int nPhrase = 0;
  (void)fts3ExprIterate(pExpr, fts3ExprPhraseCountCb, (void *)&nPhrase);
  return nPhrase;
}

  ** the set of phrases in the expression to populate the aPhrase[] array.
  */
  sIter.pCsr = pCsr;
  sIter.iCol = iCol;
  sIter.nSnippet = nSnippet;
  sIter.nPhrase = nList;
  sIter.iCurrent = -1;
  rc = fts3ExprIterate(pCsr->pExpr, fts3SnippetFindPositions, (void *)&sIter);
  rc = fts3ExprIterate(pCsr->pExpr, fts3SnippetFindPositions, (void*)&sIter);
  if( rc==SQLITE_OK ){

    /* Set the *pmSeen output variable. */
    for(i=0; i<nList; i++){
      if( sIter.aPhrase[i].pHead ){
        *pmSeen |= (u64)1 << i;
      }

    c = *pEnd++ & 0x80;
    if( !c ) nEntry++;
  }

  *ppCollist = pEnd;
  return nEntry;
}

/*
** This function gathers 'y' or 'b' data for a single phrase.
*/
static void fts3ExprLHits(
  Fts3Expr *pExpr,                /* Phrase expression node */
  MatchInfo *p                    /* Matchinfo context */
){
  Fts3Table *pTab = (Fts3Table *)p->pCursor->base.pVtab;
  int iStart;
  Fts3Phrase *pPhrase = pExpr->pPhrase;
  char *pIter = pPhrase->doclist.pList;
  int iCol = 0;

  assert( p->flag==FTS3_MATCHINFO_LHITS_BM || p->flag==FTS3_MATCHINFO_LHITS );
  if( p->flag==FTS3_MATCHINFO_LHITS ){
    iStart = pExpr->iPhrase * p->nCol;
  }else{
    iStart = pExpr->iPhrase * ((p->nCol + 31) / 32);
  }

  while( 1 ){
    int nHit = fts3ColumnlistCount(&pIter);
    if( (pPhrase->iColumn>=pTab->nColumn || pPhrase->iColumn==iCol) ){
      if( p->flag==FTS3_MATCHINFO_LHITS ){
        p->aMatchinfo[iStart + iCol] = (u32)nHit;
      }else if( nHit ){
        p->aMatchinfo[iStart + (iCol+1)/32] |= (1 << (iCol&0x1F));
      }
    }
    assert( *pIter==0x00 || *pIter==0x01 );
    if( *pIter!=0x01 ) break;
    pIter++;
    pIter += fts3GetVarint32(pIter, &iCol);
  }
}

/*
** Gather the results for matchinfo directives 'y' and 'b'.
*/
static void fts3ExprLHitGather(
  Fts3Expr *pExpr,
  MatchInfo *p
){
  assert( (pExpr->pLeft==0)==(pExpr->pRight==0) );
  if( pExpr->bEof==0 && pExpr->iDocid==p->pCursor->iPrevId ){
    if( pExpr->pLeft ){
      fts3ExprLHitGather(pExpr->pLeft, p);
      fts3ExprLHitGather(pExpr->pRight, p);
    }else{
      fts3ExprLHits(pExpr, p);
    }
  }
}

/*
** 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 

      p->aMatchinfo[iStart+i*3] = 0;
    }
  }

  return rc;
}

/*
** fts3ExprIterate() callback used to gather information for the matchinfo
** directive 'y'.
*/
static int fts3ExprLHitsCb(
  Fts3Expr *pExpr,                /* Phrase expression node */
  int iPhrase,                    /* Phrase number */
  void *pCtx                      /* Pointer to MatchInfo structure */
){
  MatchInfo *p = (MatchInfo *)pCtx;
  Fts3Table *pTab = (Fts3Table *)p->pCursor->base.pVtab;
  int rc = SQLITE_OK;
  int iStart = iPhrase * p->nCol;
  Fts3Expr *pEof;                 /* Ancestor node already at EOF */
  
  /* This must be a phrase */
  assert( pExpr->pPhrase );

  /* Initialize all output integers to zero. */
  memset(&p->aMatchinfo[iStart], 0, sizeof(u32) * p->nCol);

  /* Check if this or any parent node is at EOF. If so, then all output
  ** values are zero.  */
  for(pEof=pExpr; pEof && pEof->bEof==0; pEof=pEof->pParent);

  if( pEof==0 && pExpr->iDocid==p->pCursor->iPrevId ){
    Fts3Phrase *pPhrase = pExpr->pPhrase;
    char *pIter = pPhrase->doclist.pList;
    int iCol = 0;

    while( 1 ){
      int nHit = fts3ColumnlistCount(&pIter);
      if( (pPhrase->iColumn>=pTab->nColumn || pPhrase->iColumn==iCol) ){
        p->aMatchinfo[iStart + iCol] = (u32)nHit;
      }
      assert( *pIter==0x00 || *pIter==0x01 );
      if( *pIter!=0x01 ) break;
      pIter++;
      pIter += fts3GetVarint32(pIter, &iCol);
    }
  }

  return rc;
}

static int fts3MatchinfoCheck(
  Fts3Table *pTab, 
  char cArg,
  char **pzErr
){
  if( (cArg==FTS3_MATCHINFO_NPHRASE)
   || (cArg==FTS3_MATCHINFO_NCOL)
   || (cArg==FTS3_MATCHINFO_NDOC && pTab->bFts4)
   || (cArg==FTS3_MATCHINFO_AVGLENGTH && pTab->bFts4)
   || (cArg==FTS3_MATCHINFO_LENGTH && pTab->bHasDocsize)
   || (cArg==FTS3_MATCHINFO_LCS)
   || (cArg==FTS3_MATCHINFO_HITS)
   || (cArg==FTS3_MATCHINFO_LHITS)
   || (cArg==FTS3_MATCHINFO_LHITS_BM)
  ){
    return SQLITE_OK;
  }
  sqlite3Fts3ErrMsg(pzErr, "unrecognized matchinfo request: %c", cArg);
  return SQLITE_ERROR;
}

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

    case FTS3_MATCHINFO_LHITS:
      nVal = pInfo->nCol * pInfo->nPhrase;
      break;

    case FTS3_MATCHINFO_LHITS_BM:
      nVal = pInfo->nPhrase * ((pInfo->nCol + 31) / 32);
      break;

    default:
      assert( cArg==FTS3_MATCHINFO_HITS );
      nVal = pInfo->nCol * pInfo->nPhrase * 3;
      break;
  }

){
  int rc = SQLITE_OK;
  int i;
  Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;
  sqlite3_stmt *pSelect = 0;

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

    pInfo->flag = zArg[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;

      case FTS3_MATCHINFO_LCS:
        rc = fts3ExprLoadDoclists(pCsr, 0, 0);
        if( rc==SQLITE_OK ){
          rc = fts3MatchinfoLcs(pCsr, pInfo);
        }
        break;

      case FTS3_MATCHINFO_LHITS_BM:
      case FTS3_MATCHINFO_LHITS:
        (void)fts3ExprIterate(pCsr->pExpr, fts3ExprLHitsCb, (void*)pInfo);
      case FTS3_MATCHINFO_LHITS: {
        int nZero = fts3MatchinfoSize(pInfo, zArg[i]) * sizeof(u32);
        memset(pInfo->aMatchinfo, 0, nZero);
        fts3ExprLHitGather(pCsr->pExpr, pInfo);
        break;
      }

      default: {
        Fts3Expr *pExpr;
        assert( zArg[i]==FTS3_MATCHINFO_HITS );
        pExpr = pCsr->pExpr;
        rc = fts3ExprLoadDoclists(pCsr, 0, 0);
        if( rc!=SQLITE_OK ) break;

}


/*
** 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(
static void fts3GetMatchinfo(
  sqlite3_context *pCtx,        /* Return results here */
  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 */

  u32 *aOut = 0;
  void (*xDestroyOut)(void*) = 0;

  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) ){
  if( pCsr->pMIBuffer && strcmp(pCsr->pMIBuffer->zMatchinfo, zArg) ){
    assert( pCsr->aMatchinfo );
    sqlite3_free(pCsr->aMatchinfo);
    pCsr->zMatchinfo = 0;
    sqlite3Fts3MIBufferFree(pCsr->pMIBuffer);
    pCsr->pMIBuffer = 0;
    pCsr->aMatchinfo = 0;
  }

  /* If Fts3Cursor.aMatchinfo[] is NULL, then this is the first time the
  /* If Fts3Cursor.pMIBuffer 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 ){
  if( pCsr->pMIBuffer==0 ){
    int nMatchinfo = 0;           /* Number of u32 elements in match-info */
    int nArg;                     /* Bytes in zArg */
    int i;                        /* Used to iterate through zArg */

    /* Determine the number of phrases in the query */
    pCsr->nPhrase = fts3ExprPhraseCount(pCsr->pExpr);
    sInfo.nPhrase = pCsr->nPhrase;

    /* Determine the number of integers in the buffer returned by this call. */
    for(i=0; zArg[i]; i++){
      char *zErr = 0;
      if( fts3MatchinfoCheck(pTab, zArg[i], &zErr) ){
        sqlite3_result_error(pCtx, zErr, -1);
        sqlite3_free(zErr);
        return;
      }
      nMatchinfo += fts3MatchinfoSize(&sInfo, zArg[i]);
    }

    /* Allocate space for Fts3Cursor.aMatchinfo[] and Fts3Cursor.zMatchinfo. */
    nArg = (int)strlen(zArg);
    pCsr->pMIBuffer = fts3MIBufferNew(nMatchinfo, zArg);
    pCsr->aMatchinfo = (u32 *)sqlite3_malloc(sizeof(u32)*nMatchinfo + nArg + 1);
    if( !pCsr->aMatchinfo ) return SQLITE_NOMEM;
    if( !pCsr->pMIBuffer ) rc = 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;
  }

  if( rc==SQLITE_OK ){
    xDestroyOut = fts3MIBufferAlloc(pCsr->pMIBuffer, &aOut);
    if( xDestroyOut==0 ){
      rc = SQLITE_NOMEM;
    }
  }

  if( rc==SQLITE_OK ){
  sInfo.aMatchinfo = pCsr->aMatchinfo;
  sInfo.nPhrase = pCsr->nPhrase;
    sInfo.aMatchinfo = aOut;
    sInfo.nPhrase = pCsr->nPhrase;
  if( pCsr->isMatchinfoNeeded ){
    rc = fts3MatchinfoValues(pCsr, bGlobal, &sInfo, zArg);
    if( bGlobal ){
    pCsr->isMatchinfoNeeded = 0;
  }

  return rc;
      fts3MIBufferSetGlobal(pCsr->pMIBuffer);
    }
  }

  if( rc!=SQLITE_OK ){
    sqlite3_result_error_code(pCtx, rc);
    if( xDestroyOut ) xDestroyOut(aOut);
  }else{
    int n = pCsr->pMIBuffer->nElem * sizeof(u32);
    sqlite3_result_blob(pCtx, aOut, n, xDestroyOut);
  }
}

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

    /* Initialize the contents of sCtx.aTerm[] for column iCol. There is 
    ** no way that this operation can fail, so the return code from
    ** fts3ExprIterate() can be discarded.
    */
    sCtx.iCol = iCol;
    sCtx.iTerm = 0;
    (void)fts3ExprIterate(pCsr->pExpr, fts3ExprTermOffsetInit, (void *)&sCtx);
    (void)fts3ExprIterate(pCsr->pExpr, fts3ExprTermOffsetInit, (void*)&sCtx);

    /* Retreive the text stored in column iCol. If an SQL NULL is stored 
    ** in column iCol, jump immediately to the next iteration of the loop.
    ** If an OOM occurs while retrieving the data (this can happen if SQLite
    ** needs to transform the data from utf-16 to utf-8), return SQLITE_NOMEM 
    ** to the caller. 
    */

*/
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;
  }
  }else{

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

  7 "a OR (a AND b)" {
      1 {1 2 1 2 0 1}   2 {1 0 1 0 1 0}   3 {0 1 0 1 1 2}   4 {1 0 1 0 0 1}   
      5 {1 0 1 0 0 1}   6 {1 0 1 0 2 2}   7 {2 1 0 0 0 0}   8 {1 2 1 2 2 1}   
      9 {1 1 1 1 1 3}  10 {1 3 0 0 0 0}
  }

} {
  do_execsql_test 11.1.$tn  {
  do_execsql_test 11.1.$tn.1  {
    SELECT rowid, mit(matchinfo(tt, 'y')) FROM tt WHERE tt MATCH $expr
  } $res
}

  set r2 [list]
  foreach {rowid L} $res {
    lappend r2 $rowid
    set M [list]
    foreach {a b} $L {
      lappend M [expr ($a ? 1 : 0) + ($b ? 2 : 0)]
    }
    lappend r2 $M
  }

  do_execsql_test 11.1.$tn.2  {
    SELECT rowid, mit(matchinfo(tt, 'b')) FROM tt WHERE tt MATCH $expr
  } $r2
  breakpoint

  do_execsql_test 11.1.$tn.2  {
    SELECT rowid, mit(matchinfo(tt, 'b')) FROM tt WHERE tt MATCH $expr
  } $r2
}
set sqlite_fts3_enable_parentheses 0

#---------------------------------------------------------------------------
# Test the 'b' matchinfo flag
#
set sqlite_fts3_enable_parentheses 1
reset_db
db func mit mit

do_test 12.0 {
  set cols [list]
  for {set i 0} {$i < 50} {incr i} { lappend cols "c$i" }
  execsql "CREATE VIRTUAL TABLE tt USING fts3([join $cols ,])"
} {}

do_execsql_test 12.1 {
  INSERT INTO tt (rowid, c4, c45) VALUES(1, 'abc', 'abc');
  SELECT mit(matchinfo(tt, 'b')) FROM tt WHERE tt MATCH 'abc';
} [list [list [expr 1<<4] [expr 1<<(45-32)]]]

set sqlite_fts3_enable_parentheses 0
finish_test

} {
  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}}
  SELECT matchinfo(t2, 'abcd') FROM t2 WHERE t2 MATCH 'history'
} {1 {unrecognized matchinfo request: d}}

do_execsql_test 5.5 { DROP TABLE t2 }


# Test the snippet() function with 1 to 6 arguments.
# 
do_execsql_test 6.1 {