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-rw-r--r--src/vdbesort.c111
1 files changed, 84 insertions, 27 deletions
diff --git a/src/vdbesort.c b/src/vdbesort.c
index fdfc4a7..6a5855f 100644
--- a/src/vdbesort.c
+++ b/src/vdbesort.c
@@ -54,7 +54,7 @@ typedef struct FileWriter FileWriter;
** other key value. If the keys are equal (only possible with two EOF
** values), it doesn't matter which index is stored.
**
-** The (N/4) elements of aTree[] that preceed the final (N/2) described
+** The (N/4) elements of aTree[] that precede the final (N/2) described
** above contains the index of the smallest of each block of 4 iterators.
** And so on. So that aTree[1] contains the index of the iterator that
** currently points to the smallest key value. aTree[0] is unused.
@@ -350,7 +350,6 @@ static int vdbeSorterIterInit(
rc = sqlite3OsRead(
pSorter->pTemp1, &pIter->aBuffer[iBuf], nRead, iStart
);
- assert( rc!=SQLITE_IOERR_SHORT_READ );
}
if( rc==SQLITE_OK ){
@@ -386,7 +385,7 @@ static int vdbeSorterIterInit(
*/
static void vdbeSorterCompare(
const VdbeCursor *pCsr, /* Cursor object (for pKeyInfo) */
- int bOmitRowid, /* Ignore rowid field at end of keys */
+ int nKeyCol, /* Num of columns. 0 means "all" */
const void *pKey1, int nKey1, /* Left side of comparison */
const void *pKey2, int nKey2, /* Right side of comparison */
int *pRes /* OUT: Result of comparison */
@@ -400,19 +399,18 @@ static void vdbeSorterCompare(
sqlite3VdbeRecordUnpack(pKeyInfo, nKey2, pKey2, r2);
}
- if( bOmitRowid ){
- r2->nField = pKeyInfo->nField;
- assert( r2->nField>0 );
- for(i=0; i<r2->nField; i++){
+ if( nKeyCol ){
+ r2->nField = nKeyCol;
+ for(i=0; i<nKeyCol; i++){
if( r2->aMem[i].flags & MEM_Null ){
*pRes = -1;
return;
}
}
- r2->flags |= UNPACKED_PREFIX_MATCH;
+ assert( r2->default_rc==0 );
}
- *pRes = sqlite3VdbeRecordCompare(nKey1, pKey1, r2);
+ *pRes = sqlite3VdbeRecordCompare(nKey1, pKey1, r2, 0);
}
/*
@@ -505,22 +503,39 @@ static void vdbeSorterRecordFree(sqlite3 *db, SorterRecord *pRecord){
}
/*
+** Reset a sorting cursor back to its original empty state.
+*/
+void sqlite3VdbeSorterReset(sqlite3 *db, VdbeSorter *pSorter){
+ if( pSorter->aIter ){
+ int i;
+ for(i=0; i<pSorter->nTree; i++){
+ vdbeSorterIterZero(db, &pSorter->aIter[i]);
+ }
+ sqlite3DbFree(db, pSorter->aIter);
+ pSorter->aIter = 0;
+ }
+ if( pSorter->pTemp1 ){
+ sqlite3OsCloseFree(pSorter->pTemp1);
+ pSorter->pTemp1 = 0;
+ }
+ vdbeSorterRecordFree(db, pSorter->pRecord);
+ pSorter->pRecord = 0;
+ pSorter->iWriteOff = 0;
+ pSorter->iReadOff = 0;
+ pSorter->nInMemory = 0;
+ pSorter->nTree = 0;
+ pSorter->nPMA = 0;
+ pSorter->aTree = 0;
+}
+
+
+/*
** Free any cursor components allocated by sqlite3VdbeSorterXXX routines.
*/
void sqlite3VdbeSorterClose(sqlite3 *db, VdbeCursor *pCsr){
VdbeSorter *pSorter = pCsr->pSorter;
if( pSorter ){
- if( pSorter->aIter ){
- int i;
- for(i=0; i<pSorter->nTree; i++){
- vdbeSorterIterZero(db, &pSorter->aIter[i]);
- }
- sqlite3DbFree(db, pSorter->aIter);
- }
- if( pSorter->pTemp1 ){
- sqlite3OsCloseFree(pSorter->pTemp1);
- }
- vdbeSorterRecordFree(db, pSorter->pRecord);
+ sqlite3VdbeSorterReset(db, pSorter);
sqlite3DbFree(db, pSorter->pUnpacked);
sqlite3DbFree(db, pSorter);
pCsr->pSorter = 0;
@@ -956,14 +971,55 @@ int sqlite3VdbeSorterNext(sqlite3 *db, const VdbeCursor *pCsr, int *pbEof){
if( pSorter->aTree ){
int iPrev = pSorter->aTree[1];/* Index of iterator to advance */
- int i; /* Index of aTree[] to recalculate */
-
rc = vdbeSorterIterNext(db, &pSorter->aIter[iPrev]);
- for(i=(pSorter->nTree+iPrev)/2; rc==SQLITE_OK && i>0; i=i/2){
- rc = vdbeSorterDoCompare(pCsr, i);
- }
+ if( rc==SQLITE_OK ){
+ int i; /* Index of aTree[] to recalculate */
+ VdbeSorterIter *pIter1; /* First iterator to compare */
+ VdbeSorterIter *pIter2; /* Second iterator to compare */
+ u8 *pKey2; /* To pIter2->aKey, or 0 if record cached */
+
+ /* Find the first two iterators to compare. The one that was just
+ ** advanced (iPrev) and the one next to it in the array. */
+ pIter1 = &pSorter->aIter[(iPrev & 0xFFFE)];
+ pIter2 = &pSorter->aIter[(iPrev | 0x0001)];
+ pKey2 = pIter2->aKey;
+
+ for(i=(pSorter->nTree+iPrev)/2; i>0; i=i/2){
+ /* Compare pIter1 and pIter2. Store the result in variable iRes. */
+ int iRes;
+ if( pIter1->pFile==0 ){
+ iRes = +1;
+ }else if( pIter2->pFile==0 ){
+ iRes = -1;
+ }else{
+ vdbeSorterCompare(pCsr, 0,
+ pIter1->aKey, pIter1->nKey, pKey2, pIter2->nKey, &iRes
+ );
+ }
- *pbEof = (pSorter->aIter[pSorter->aTree[1]].pFile==0);
+ /* If pIter1 contained the smaller value, set aTree[i] to its index.
+ ** Then set pIter2 to the next iterator to compare to pIter1. In this
+ ** case there is no cache of pIter2 in pSorter->pUnpacked, so set
+ ** pKey2 to point to the record belonging to pIter2.
+ **
+ ** Alternatively, if pIter2 contains the smaller of the two values,
+ ** set aTree[i] to its index and update pIter1. If vdbeSorterCompare()
+ ** was actually called above, then pSorter->pUnpacked now contains
+ ** a value equivalent to pIter2. So set pKey2 to NULL to prevent
+ ** vdbeSorterCompare() from decoding pIter2 again. */
+ if( iRes<=0 ){
+ pSorter->aTree[i] = (int)(pIter1 - pSorter->aIter);
+ pIter2 = &pSorter->aIter[ pSorter->aTree[i ^ 0x0001] ];
+ pKey2 = pIter2->aKey;
+ }else{
+ if( pIter1->pFile ) pKey2 = 0;
+ pSorter->aTree[i] = (int)(pIter2 - pSorter->aIter);
+ pIter1 = &pSorter->aIter[ pSorter->aTree[i ^ 0x0001] ];
+ }
+
+ }
+ *pbEof = (pSorter->aIter[pSorter->aTree[1]].pFile==0);
+ }
}else{
SorterRecord *pFree = pSorter->pRecord;
pSorter->pRecord = pFree->pNext;
@@ -1027,12 +1083,13 @@ int sqlite3VdbeSorterRowkey(const VdbeCursor *pCsr, Mem *pOut){
int sqlite3VdbeSorterCompare(
const VdbeCursor *pCsr, /* Sorter cursor */
Mem *pVal, /* Value to compare to current sorter key */
+ int nKeyCol, /* Only compare this many fields */
int *pRes /* OUT: Result of comparison */
){
VdbeSorter *pSorter = pCsr->pSorter;
void *pKey; int nKey; /* Sorter key to compare pVal with */
pKey = vdbeSorterRowkey(pSorter, &nKey);
- vdbeSorterCompare(pCsr, 1, pVal->z, pVal->n, pKey, nKey, pRes);
+ vdbeSorterCompare(pCsr, nKeyCol, pVal->z, pVal->n, pKey, nKey, pRes);
return SQLITE_OK;
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-09 17:42:04 +0000