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Change the way ^ tokens work in FTS so that the filtering is done as part of reading the FTS index instead of waiting until an entire doclist has been retrieved and then filtering it.

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FossilOrigin-Name: 9b58c59eb4efaa38ce50a3ce1b52f9ba578c71d6
This commit is contained in:
dan
2011-10-19 11:57:13 +00:00
parent 8653fa8504
commit d17f70a624
5 changed files with 72 additions and 72 deletions
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97
ext/fts3/fts3.c
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@ -2348,65 +2348,53 @@ static void fts3DoclistPhraseMerge(
}
/*
** When this function is called, pList points to a doclist containing position
** data, length *pnList bytes. This removes all entries from the doclist that
** do not correspond to the first token in a column and overwrites pList
** with the result. *pnList is set to the length of the new doclist before
** returning.
**
** If bDescDoclist is true, then both the input and output are in descending
** order. Otherwise, ascending.
** Argument pList points to a position list nList bytes in size. This
** function checks to see if the position list contains any entries for
** a token in position 0 (of any column). If so, it writes argument iDelta
** to the output buffer pOut, followed by a position list consisting only
** of the entries from pList at position 0, and terminated by an 0x00 byte.
** The value returned is the number of bytes written to pOut (if any).
*/
static void fts3DoclistFirstFilter(
int bDescDoclist, /* True if pList is a descending doclist */
char *pList, /* Buffer containing doclist */
int *pnList /* IN/OUT: Size of doclist */
int sqlite3Fts3FirstFilter(
sqlite3_int64 iDelta, /* Varint that may be written to pOut */
char *pList, /* Position list (no 0x00 term) */
int nList, /* Size of pList in bytes */
char *pOut /* Write output here */
){
int nOut = 0;
int bWritten = 0; /* True once iDelta has been written */
char *p = pList;
char *pOut = pList;
char *pEnd = &pList[*pnList];
char *pEnd = &pList[nList];
sqlite3_int64 iDoc;
sqlite3_int64 iPrev;
int bFirstOut = 0;
fts3GetDeltaVarint3(&p, pEnd, 0, &iDoc);
while( p ){
int bWritten = 0;
if( *p!=0x01 ){
if( *p==0x02 ){
fts3PutDeltaVarint3(&pOut, bDescDoclist, &iPrev, &bFirstOut, iDoc);
*pOut++ = 0x02;
bWritten = 1;
}
fts3ColumnlistCopy(0, &p);
if( *p!=0x01 ){
if( *p==0x02 ){
nOut += sqlite3Fts3PutVarint(&pOut[nOut], iDelta);
pOut[nOut++] = 0x02;
bWritten = 1;
}
while( *p==0x01 ){
sqlite3_int64 iCol;
p++;
p += sqlite3Fts3GetVarint(p, &iCol);
if( *p==0x02 ){
if( bWritten==0 ){
fts3PutDeltaVarint3(&pOut, bDescDoclist, &iPrev, &bFirstOut, iDoc);
bWritten = 1;
}
*pOut++ = 0x01;
pOut += sqlite3Fts3PutVarint(pOut, iCol);
*pOut++ = 0x02;
}
fts3ColumnlistCopy(0, &p);
}
if( bWritten ){
*pOut++ = 0x00;
}
assert( *p==0x00 );
p++;
fts3GetDeltaVarint3(&p, pEnd, bDescDoclist, &iDoc);
fts3ColumnlistCopy(0, &p);
}
*pnList = (pOut - pList);
while( p<pEnd && *p==0x01 ){
sqlite3_int64 iCol;
p++;
p += sqlite3Fts3GetVarint(p, &iCol);
if( *p==0x02 ){
if( bWritten==0 ){
nOut += sqlite3Fts3PutVarint(&pOut[nOut], iDelta);
bWritten = 1;
}
pOut[nOut++] = 0x01;
nOut += sqlite3Fts3PutVarint(&pOut[nOut], iCol);
pOut[nOut++] = 0x02;
}
fts3ColumnlistCopy(0, &p);
}
if( bWritten ){
pOut[nOut++] = 0x00;
}
return nOut;
}
@ -2765,6 +2753,7 @@ static int fts3TermSelect(
filter.flags = FTS3_SEGMENT_IGNORE_EMPTY | FTS3_SEGMENT_REQUIRE_POS
| (pTok->isPrefix ? FTS3_SEGMENT_PREFIX : 0)
| (pTok->bFirst ? FTS3_SEGMENT_FIRST : 0)
| (iColumn<p->nColumn ? FTS3_SEGMENT_COLUMN_FILTER : 0);
filter.iCol = iColumn;
filter.zTerm = pTok->z;
@ -3580,10 +3569,6 @@ static void fts3EvalPhraseMergeToken(
){
assert( iToken!=p->iDoclistToken );
if( p->aToken[iToken].bFirst ){
fts3DoclistFirstFilter(pTab->bDescIdx, pList, &nList);
}
if( pList==0 ){
sqlite3_free(p->doclist.aAll);
p->doclist.aAll = 0;