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Further improve performance of unindexed fts5 prefix queries.

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FossilOrigin-Name: c9c6457d8ea911f6cc63967127e58da3146fd3ef
This commit is contained in:
dan
2016-02-04 19:45:19 +00:00
parent be7721d103
commit 4786cf5a20
3 changed files with 87 additions and 69 deletions
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ext/fts5/fts5_index.c
+78 -60
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@@ -4705,76 +4705,94 @@ static void fts5MergePrefixLists(
Fts5Buffer *p2 /* Second list to merge */
){
if( p2->n ){
i64 iLastRowid = 0;
Fts5DoclistIter i1;
Fts5DoclistIter i2;
Fts5Buffer out;
Fts5Buffer tmp;
memset(&out, 0, sizeof(out));
memset(&tmp, 0, sizeof(tmp));
if( p1->n==0 ){
fts5BufferSwap(p1, p2);
}else{
i64 iLastRowid = 0;
Fts5DoclistIter i1;
Fts5DoclistIter i2;
Fts5Buffer out = {0, 0, 0};
Fts5Buffer tmp = {0, 0, 0};
sqlite3Fts5BufferSize(&p->rc, &out, p1->n + p2->n);
fts5DoclistIterInit(p1, &i1);
fts5DoclistIterInit(p2, &i2);
while( p->rc==SQLITE_OK && (i1.aPoslist!=0 || i2.aPoslist!=0) ){
if( i2.aPoslist==0 || (i1.aPoslist && i1.iRowid<i2.iRowid) ){
/* Copy entry from i1 */
fts5MergeAppendDocid(&out, iLastRowid, i1.iRowid);
fts5BufferSafeAppendBlob(&out, i1.aPoslist, i1.nPoslist+i1.nSize);
fts5DoclistIterNext(&i1);
}
else if( i1.aPoslist==0 || i2.iRowid!=i1.iRowid ){
/* Copy entry from i2 */
fts5MergeAppendDocid(&out, iLastRowid, i2.iRowid);
fts5BufferSafeAppendBlob(&out, i2.aPoslist, i2.nPoslist+i2.nSize);
fts5DoclistIterNext(&i2);
}
else{
i64 iPos1 = 0;
i64 iPos2 = 0;
int iOff1 = 0;
int iOff2 = 0;
u8 *a1 = &i1.aPoslist[i1.nSize];
u8 *a2 = &i2.aPoslist[i2.nSize];
if( sqlite3Fts5BufferSize(&p->rc, &out, p1->n + p2->n) ) return;
fts5DoclistIterInit(p1, &i1);
fts5DoclistIterInit(p2, &i2);
Fts5PoslistWriter writer;
memset(&writer, 0, sizeof(writer));
while( 1 ){
/* Merge the two position lists. */
fts5MergeAppendDocid(&out, iLastRowid, i2.iRowid);
fts5BufferZero(&tmp);
if( i1.iRowid<i2.iRowid ){
/* Copy entry from i1 */
fts5MergeAppendDocid(&out, iLastRowid, i1.iRowid);
fts5BufferSafeAppendBlob(&out, i1.aPoslist, i1.nPoslist+i1.nSize);
fts5DoclistIterNext(&i1);
if( i1.aPoslist==0 ) break;
}
else if( i2.iRowid!=i1.iRowid ){
/* Copy entry from i2 */
fts5MergeAppendDocid(&out, iLastRowid, i2.iRowid);
fts5BufferSafeAppendBlob(&out, i2.aPoslist, i2.nPoslist+i2.nSize);
fts5DoclistIterNext(&i2);
if( i2.aPoslist==0 ) break;
}
else{
i64 iPos1 = 0;
i64 iPos2 = 0;
int iOff1 = 0;
int iOff2 = 0;
u8 *a1 = &i1.aPoslist[i1.nSize];
u8 *a2 = &i2.aPoslist[i2.nSize];
sqlite3Fts5PoslistNext64(a1, i1.nPoslist, &iOff1, &iPos1);
sqlite3Fts5PoslistNext64(a2, i2.nPoslist, &iOff2, &iPos2);
Fts5PoslistWriter writer;
memset(&writer, 0, sizeof(writer));
while( p->rc==SQLITE_OK && (iPos1>=0 || iPos2>=0) ){
i64 iNew;
if( iPos2<0 || (iPos1>=0 && iPos1<iPos2) ){
iNew = iPos1;
sqlite3Fts5PoslistNext64(a1, i1.nPoslist, &iOff1, &iPos1);
}else{
iNew = iPos2;
sqlite3Fts5PoslistNext64(a2, i2.nPoslist, &iOff2, &iPos2);
if( iPos1==iPos2 ){
sqlite3Fts5PoslistNext64(a1, i1.nPoslist, &iOff1,&iPos1);
/* Merge the two position lists. */
fts5MergeAppendDocid(&out, iLastRowid, i2.iRowid);
fts5BufferZero(&tmp);
sqlite3Fts5PoslistNext64(a1, i1.nPoslist, &iOff1, &iPos1);
sqlite3Fts5PoslistNext64(a2, i2.nPoslist, &iOff2, &iPos2);
while( iPos1>=0 || iPos2>=0 ){
i64 iNew;
if( iPos2<0 || (iPos1>=0 && iPos1<iPos2) ){
iNew = iPos1;
sqlite3Fts5PoslistNext64(a1, i1.nPoslist, &iOff1, &iPos1);
}else{
iNew = iPos2;
sqlite3Fts5PoslistNext64(a2, i2.nPoslist, &iOff2, &iPos2);
if( iPos1==iPos2 ){
sqlite3Fts5PoslistNext64(a1, i1.nPoslist, &iOff1,&iPos1);
}
}
if( iNew!=writer.iPrev || tmp.n==0 ){
p->rc = sqlite3Fts5PoslistWriterAppend(&tmp, &writer, iNew);
if( p->rc ) goto error_out;
}
}
if( iNew!=writer.iPrev || tmp.n==0 ){
p->rc = sqlite3Fts5PoslistWriterAppend(&tmp, &writer, iNew);
}
/* WRITEPOSLISTSIZE */
fts5BufferSafeAppendVarint(&out, tmp.n * 2);
fts5BufferSafeAppendBlob(&out, tmp.p, tmp.n);
fts5DoclistIterNext(&i1);
fts5DoclistIterNext(&i2);
if( i1.aPoslist==0 || i2.aPoslist==0 ) break;
}
/* WRITEPOSLISTSIZE */
fts5BufferSafeAppendVarint(&out, tmp.n * 2);
fts5BufferSafeAppendBlob(&out, tmp.p, tmp.n);
fts5DoclistIterNext(&i1);
fts5DoclistIterNext(&i2);
}
}
fts5BufferSet(&p->rc, p1, out.n, out.p);
fts5BufferFree(&tmp);
fts5BufferFree(&out);
if( i1.aPoslist ){
fts5MergeAppendDocid(&out, iLastRowid, i1.iRowid);
fts5BufferSafeAppendBlob(&out, i1.aPoslist, i1.aEof - i1.aPoslist);
}
else if( i2.aPoslist ){
fts5MergeAppendDocid(&out, iLastRowid, i2.iRowid);
fts5BufferSafeAppendBlob(&out, i2.aPoslist, i2.aEof - i2.aPoslist);
}
error_out:
fts5BufferSet(&p->rc, p1, out.n, out.p);
fts5BufferFree(&tmp);
fts5BufferFree(&out);
}
}
}