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Overview
| Comment: | This change turned out to the code slower. Side track it. Was: Tweaks to the OP_Column opcode for clarity of presentation. |
|---|---|
| Downloads: | Tarball | ZIP archive | SQL archive |
| Timelines: | family | ancestors | mistake |
| Files: | files | file ages | folders |
| SHA1: |
4d516240d2e465b21f8e31293b987731 |
| User & Date: | drh 2012-03-28 15:44:11 |
| Original Comment: | Futher tweaks to the OP_Column opcode for clarity of presentation. |
Context
|
2012-03-28
| ||
| 15:44 | This change turned out to the code slower. Side track it. Was: Tweaks to the OP_Column opcode for clarity of presentation. Closed-Leaf check-in: 4d516240 user: drh tags: mistake | |
| 13:41 | Improvements to comments. Minor changes to code in the hot path of OP_Column - with the hope of get a few cycles of performance improvement. check-in: ca093103 user: drh tags: faster-typeof-and-length | |
Changes
Changes to src/vdbe.c.
2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 |
** deserialize the value from the record. If aOffset[p2] is zero,
** then there are not enough fields in the record to satisfy the
** request. In this case, set the value NULL or to P4 if P4 is
** a pointer to a Mem object.
*/
if( aOffset[p2] ){
assert( rc==SQLITE_OK );
if( zRec ){
VdbeMemRelease(pDest);
sqlite3VdbeSerialGet((u8 *)&zRec[aOffset[p2]], aType[p2], pDest);
}else{
t = aType[p2];
len = sqlite3VdbeSerialTypeLen(t);
if( (pOp->p5 & (OPFLAG_LENGTHARG|OPFLAG_TYPEOFARG))!=0
&& ((t>=12 && (t&1)==0) || (pOp->p5 & OPFLAG_TYPEOFARG)!=0)
){
/* Content is irrelevant for the typeof() function and for
** the length(X) function if X is a blob. So we might as well use
** bogus content rather than reading content from disk. NULL works
** for text and blob and whatever is in the payloadSize64 variable
** will work for everything else. */
zData = t<12 ? (char*)&payloadSize64 : 0;
}else{
sqlite3VdbeMemMove(&sMem, pDest);
rc = sqlite3VdbeMemFromBtree(pCrsr, aOffset[p2], len, pC->isIndex,
&sMem);
if( rc!=SQLITE_OK ){
goto op_column_out;
}
zData = sMem.z;
}
sqlite3VdbeSerialGet((u8*)zData, t, pDest);
}
pDest->enc = encoding;
}else{
if( pOp->p4type==P4_MEM ){
sqlite3VdbeMemShallowCopy(pDest, pOp->p4.pMem, MEM_Static);
}else{
MemSetTypeFlag(pDest, MEM_Null);
}
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> | | < < | | | | | | | | | | > | | | | | | | | | < |
2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 |
** deserialize the value from the record. If aOffset[p2] is zero,
** then there are not enough fields in the record to satisfy the
** request. In this case, set the value NULL or to P4 if P4 is
** a pointer to a Mem object.
*/
if( aOffset[p2] ){
assert( rc==SQLITE_OK );
t = aType[p2];
if( zRec ){
VdbeMemRelease(pDest);
zData = &zRec[aOffset[p2]];
}else if(
(pOp->p5 & (OPFLAG_LENGTHARG|OPFLAG_TYPEOFARG))!=0
&& ((t>=12 && (t&1)==0) || (pOp->p5 & OPFLAG_TYPEOFARG)!=0)
){
/* Content is irrelevant for the typeof() function and for
** the length(X) function if X is a blob. So we might as well use
** bogus content rather than reading content from disk. NULL works
** for text and blob and whatever is in the payloadSize64 variable
** will work for everything else. */
zData = t<12 ? (char*)&payloadSize64 : 0;
}else{
len = sqlite3VdbeSerialTypeLen(t);
sqlite3VdbeMemMove(&sMem, pDest);
rc = sqlite3VdbeMemFromBtree(pCrsr, aOffset[p2], len, pC->isIndex,
&sMem);
if( rc!=SQLITE_OK ){
goto op_column_out;
}
zData = sMem.z;
}
sqlite3VdbeSerialGet((u8*)zData, t, pDest);
pDest->enc = encoding;
}else{
if( pOp->p4type==P4_MEM ){
sqlite3VdbeMemShallowCopy(pDest, pOp->p4.pMem, MEM_Static);
}else{
MemSetTypeFlag(pDest, MEM_Null);
}
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