SQLite

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

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

    }else{
      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)
  ){
    return SQLITE_OK;
  }
  sqlite3Fts3ErrMsg(pzErr, "unrecognized matchinfo request: %c", cArg);
  return SQLITE_ERROR;
}

      break;

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

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

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

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

      case FTS3_MATCHINFO_LHITS:
        (void)fts3ExprIterate(pCsr->pExpr, fts3ExprLHitsCb, (void*)pInfo);
        break;

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

    JOIN (SELECT 1 AS idx UNION SELECT 2 UNION SELECT 3) AS x
   WHERE t10 MATCH x.idx
     AND matchinfo(t10) not null
   GROUP BY docId
   ORDER BY 1;
} {1 1 one 2 2 two 3 3 three}
  
#---------------------------------------------------------------------------
# Test the 'y' matchinfo flag
#
set sqlite_fts3_enable_parentheses 1
reset_db
do_execsql_test 11.0 {
  CREATE VIRTUAL TABLE tt USING fts3(x, y);
  INSERT INTO tt VALUES('c d a c d d', 'e a g b d a');   -- 1
  INSERT INTO tt VALUES('c c g a e b', 'c g d g e c');   -- 2
  INSERT INTO tt VALUES('b e f d e g', 'b a c b c g');   -- 3
  INSERT INTO tt VALUES('a c f f g d', 'd b f d e g');   -- 4
  INSERT INTO tt VALUES('g a c f c f', 'd g g b c c');   -- 5
  INSERT INTO tt VALUES('g a c e b b', 'd b f b g g');   -- 6
  INSERT INTO tt VALUES('f d a a f c', 'e e a d c f');   -- 7
  INSERT INTO tt VALUES('a c b b g f', 'a b a e d f');   -- 8
  INSERT INTO tt VALUES('b a f e c c', 'f d b b a b');   -- 9
  INSERT INTO tt VALUES('f d c e a c', 'f a f a a f');   -- 10
}

db func mit mit
foreach {tn expr res} {
  1 "a" {
      1 {1 2}   2 {1 0}   3 {0 1}   4 {1 0}   5 {1 0}
      6 {1 0}   7 {2 1}   8 {1 2}   9 {1 1}  10 {1 3}
  }

  2 "b" {
      1 {0 1}   2 {1 0}   3 {1 2}   4 {0 1}   5 {0 1}
      6 {2 2}             8 {2 1}   9 {1 3}            
  }

  3 "y:a" {
      1 {0 2}             3 {0 1}                    
                7 {0 1}   8 {0 2}   9 {0 1}  10 {0 3}
  }

  4 "x:a" {
      1 {1 0}   2 {1 0}             4 {1 0}   5 {1 0}
      6 {1 0}   7 {2 0}   8 {1 0}   9 {1 0}  10 {1 0}
  }

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

  6 "a AND b" {
      1 {1 2 0 1}   2 {1 0 1 0}   3 {0 1 1 2}   4 {1 0 0 1}   5 {1 0 0 1}
      6 {1 0 2 2}                 8 {1 2 2 1}   9 {1 1 1 3}              
  }

  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  {
    SELECT rowid, mit(matchinfo(tt, 'y')) FROM tt WHERE tt MATCH $expr
  } $res
}
set sqlite_fts3_enable_parentheses 0

finish_test