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Avoid some unnecessary calls to sqlite3VdbeRecordUnpack() that were being made when merging data from two or more temp files together in vdbesort.c

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FossilOrigin-Name: 707ea170b3e26965b7e3982f7554d122d130b9a6
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dan
2014-03-19 20:01:25 +00:00
parent 0e682099a1
commit 344510e62b
3 changed files with 55 additions and 14 deletions
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53
src/vdbesort.c
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@@ -956,14 +956,55 @@ 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 */
*pbEof = (pSorter->aIter[pSorter->aTree[1]].pFile==0);
/* 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
);
}
/* 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] = (pIter1 - pSorter->aIter);
pIter2 = &pSorter->aIter[ pSorter->aTree[i ^ 0x0001] ];
pKey2 = pIter2->aKey;
}else{
if( pIter1->pFile ) pKey2 = 0;
pSorter->aTree[i] = (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;