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Remove the VdbeCursor.lastRowid cache of the current rowid, since maintaining

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the correct cache value uses more CPU cycles than just recomputing the rowid
on the occasions when it is actually needed.  Replace it with the
VdbeCursor.aOffset field which used to be computed from VdbeCursor.aType
when needed. Saves 100 bytes of code space and runs 0.2% faster.

FossilOrigin-Name: 91384a7d727ef0f285cd430e829ba9f3852db50e
This commit is contained in:
drh
2014-10-12 22:37:22 +00:00
parent c81aa2e120
commit b53a5a9e50
5 changed files with 28 additions and 51 deletions
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56
src/vdbe.c
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@@ -214,6 +214,7 @@ static VdbeCursor *allocateCursor(
memset(pCx, 0, sizeof(VdbeCursor));
pCx->iDb = iDb;
pCx->nField = nField;
pCx->aOffset = &pCx->aType[nField];
if( isBtreeCursor ){
pCx->pCursor = (BtCursor*)
&pMem->z[ROUND8(sizeof(VdbeCursor))+2*sizeof(u32)*nField];
@@ -2276,7 +2277,7 @@ case OP_Column: {
pC = p->apCsr[pOp->p1];
assert( pC!=0 );
assert( p2<pC->nField );
aOffset = pC->aType + pC->nField;
aOffset = pC->aOffset;
#ifndef SQLITE_OMIT_VIRTUALTABLE
assert( pC->pVtabCursor==0 ); /* OP_Column never called on virtual table */
#endif
@@ -3563,7 +3564,6 @@ case OP_SeekGT: { /* jump, in3 */
applyNumericAffinity(pIn3, 0);
}
iKey = sqlite3VdbeIntValue(pIn3);
pC->rowidIsValid = 0;
/* If the P3 value could not be converted into an integer without
** loss of information, then special processing is required... */
@@ -3599,13 +3599,10 @@ case OP_SeekGT: { /* jump, in3 */
}
}
rc = sqlite3BtreeMovetoUnpacked(pC->pCursor, 0, (u64)iKey, 0, &res);
pC->movetoTarget = iKey; /* Used by OP_Delete */
if( rc!=SQLITE_OK ){
goto abort_due_to_error;
}
if( res==0 ){
pC->rowidIsValid = 1;
pC->lastRowid = iKey;
}
}else{
nField = pOp->p4.i;
assert( pOp->p4type==P4_INT32 );
@@ -3635,7 +3632,6 @@ case OP_SeekGT: { /* jump, in3 */
if( rc!=SQLITE_OK ){
goto abort_due_to_error;
}
pC->rowidIsValid = 0;
}
pC->deferredMoveto = 0;
pC->cacheStatus = CACHE_STALE;
@@ -3647,7 +3643,6 @@ case OP_SeekGT: { /* jump, in3 */
res = 0;
rc = sqlite3BtreeNext(pC->pCursor, &res);
if( rc!=SQLITE_OK ) goto abort_due_to_error;
pC->rowidIsValid = 0;
}else{
res = 0;
}
@@ -3657,7 +3652,6 @@ case OP_SeekGT: { /* jump, in3 */
res = 0;
rc = sqlite3BtreePrevious(pC->pCursor, &res);
if( rc!=SQLITE_OK ) goto abort_due_to_error;
pC->rowidIsValid = 0;
}else{
/* res might be negative because the table is empty. Check to
** see if this is the case.
@@ -3694,7 +3688,6 @@ case OP_Seek: { /* in2 */
pC->nullRow = 0;
pIn2 = &aMem[pOp->p2];
pC->movetoTarget = sqlite3VdbeIntValue(pIn2);
pC->rowidIsValid = 0;
pC->deferredMoveto = 1;
break;
}
@@ -3880,15 +3873,13 @@ case OP_NotExists: { /* jump, in3 */
res = 0;
iKey = pIn3->u.i;
rc = sqlite3BtreeMovetoUnpacked(pCrsr, 0, iKey, 0, &res);
pC->lastRowid = pIn3->u.i;
pC->rowidIsValid = res==0 ?1:0;
pC->movetoTarget = iKey; /* Used by OP_Delete */
pC->nullRow = 0;
pC->cacheStatus = CACHE_STALE;
pC->deferredMoveto = 0;
VdbeBranchTaken(res!=0,2);
if( res!=0 ){
pc = pOp->p2 - 1;
assert( pC->rowidIsValid==0 );
}
pC->seekResult = res;
break;
@@ -4036,7 +4027,6 @@ case OP_NewRowid: { /* out2-prerelease */
}
assert( v>0 ); /* EV: R-40812-03570 */
}
pC->rowidIsValid = 0;
pC->deferredMoveto = 0;
pC->cacheStatus = CACHE_STALE;
}
@@ -4141,7 +4131,6 @@ case OP_InsertInt: {
pData->z, pData->n, nZero,
(pOp->p5 & OPFLAG_APPEND)!=0, seekResult
);
pC->rowidIsValid = 0;
pC->deferredMoveto = 0;
pC->cacheStatus = CACHE_STALE;
@@ -4178,33 +4167,32 @@ case OP_InsertInt: {
** using OP_NotFound prior to invoking this opcode.
*/
case OP_Delete: {
i64 iKey;
VdbeCursor *pC;
assert( pOp->p1>=0 && pOp->p1<p->nCursor );
pC = p->apCsr[pOp->p1];
assert( pC!=0 );
assert( pC->pCursor!=0 ); /* Only valid for real tables, no pseudotables */
iKey = pC->lastRowid; /* Only used for the update hook */
/* The OP_Delete opcode always follows an OP_NotExists or OP_Last or
** OP_Column on the same table without any intervening operations that
** might move or invalidate the cursor. Hence cursor pC is always pointing
** to the row to be deleted and the sqlite3VdbeCursorMoveto() operation
** below is always a no-op and cannot fail. We will run it anyhow, though,
** to guard against future changes to the code generator.
**/
assert( pC->deferredMoveto==0 );
rc = sqlite3VdbeCursorMoveto(pC);
if( NEVER(rc!=SQLITE_OK) ) goto abort_due_to_error;
#ifdef SQLITE_DEBUG
/* The seek operation that positioned the cursor prior to OP_Delete will
** have also set the pC->movetoTarget field to the rowid of the row that
** is being deleted */
if( pOp->p4.z && pC->isTable ){
i64 iKey = 0;
sqlite3BtreeKeySize(pC->pCursor, &iKey);
assert( pC->movetoTarget==iKey );
}
#endif
rc = sqlite3BtreeDelete(pC->pCursor);
pC->cacheStatus = CACHE_STALE;
/* Invoke the update-hook if required. */
if( rc==SQLITE_OK && db->xUpdateCallback && pOp->p4.z && pC->isTable ){
db->xUpdateCallback(db->pUpdateArg, SQLITE_DELETE,
db->aDb[pC->iDb].zName, pOp->p4.z, iKey);
db->aDb[pC->iDb].zName, pOp->p4.z, pC->movetoTarget);
assert( pC->iDb>=0 );
}
if( pOp->p2 & OPFLAG_NCHANGE ) p->nChange++;
@@ -4396,12 +4384,8 @@ case OP_Rowid: { /* out2-prerelease */
assert( pC->pCursor!=0 );
rc = sqlite3VdbeCursorMoveto(pC);
if( rc ) goto abort_due_to_error;
if( pC->rowidIsValid ){
v = pC->lastRowid;
}else{
rc = sqlite3BtreeKeySize(pC->pCursor, &v);
assert( rc==SQLITE_OK ); /* Always so because of CursorMoveto() above */
}
rc = sqlite3BtreeKeySize(pC->pCursor, &v);
assert( rc==SQLITE_OK ); /* Always so because of CursorMoveto() above */
}
pOut->u.i = v;
break;
@@ -4420,7 +4404,6 @@ case OP_NullRow: {
pC = p->apCsr[pOp->p1];
assert( pC!=0 );
pC->nullRow = 1;
pC->rowidIsValid = 0;
pC->cacheStatus = CACHE_STALE;
if( pC->pCursor ){
sqlite3BtreeClearCursor(pC->pCursor);
@@ -4454,7 +4437,6 @@ case OP_Last: { /* jump */
rc = sqlite3BtreeLast(pCrsr, &res);
pC->nullRow = (u8)res;
pC->deferredMoveto = 0;
pC->rowidIsValid = 0;
pC->cacheStatus = CACHE_STALE;
#ifdef SQLITE_DEBUG
pC->seekOp = OP_Last;
@@ -4521,7 +4503,6 @@ case OP_Rewind: { /* jump */
rc = sqlite3BtreeFirst(pCrsr, &res);
pC->deferredMoveto = 0;
pC->cacheStatus = CACHE_STALE;
pC->rowidIsValid = 0;
}
pC->nullRow = (u8)res;
assert( pOp->p2>0 && pOp->p2<p->nOp );
@@ -4647,7 +4628,6 @@ next_tail:
}else{
pC->nullRow = 1;
}
pC->rowidIsValid = 0;
goto check_for_interrupt;
}