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Overview
| Comment: | Another simplification to the OP_MakeRecord opcode, making it slightly faster and very slightly smaller. |
|---|---|
| Downloads: | Tarball | ZIP archive |
| Timelines: | family | ancestors | descendants | both | trunk |
| Files: | files | file ages | folders |
| SHA1: |
f2f5a3ce9d075c4b1ac586c5db3a623d |
| User & Date: | drh 2013-12-08 23:33:28.824 |
Context
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2013-12-09
| ||
| 00:47 | Use putVarint32() instead of putVarint() for a quantity that can never exceed 2GiB - 1. (check-in: 6996fb3444 user: drh tags: trunk) | |
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2013-12-08
| ||
| 23:33 | Another simplification to the OP_MakeRecord opcode, making it slightly faster and very slightly smaller. (check-in: f2f5a3ce9d user: drh tags: trunk) | |
| 22:59 | Avoid unnecessary calls to sqlite3VarintLen() from the OP_MakeRecord opcode. (check-in: 7a234fc3c5 user: drh tags: trunk) | |
Changes
Changes to src/vdbe.c.
| ︙ | ︙ | |||
2556 2557 2558 2559 2560 2561 2562 | int nVarint; /* Number of bytes in a varint */ u32 serial_type; /* Type field */ Mem *pData0; /* First field to be combined into the record */ Mem *pLast; /* Last field of the record */ int nField; /* Number of fields in the record */ char *zAffinity; /* The affinity string for the record */ int file_format; /* File format to use for encoding */ | | > | 2556 2557 2558 2559 2560 2561 2562 2563 2564 2565 2566 2567 2568 2569 2570 2571 | int nVarint; /* Number of bytes in a varint */ u32 serial_type; /* Type field */ Mem *pData0; /* First field to be combined into the record */ Mem *pLast; /* Last field of the record */ int nField; /* Number of fields in the record */ char *zAffinity; /* The affinity string for the record */ int file_format; /* File format to use for encoding */ int i; /* Space used in zNewRecord[] header */ int j; /* Space used in zNewRecord[] content */ int len; /* Length of a field */ /* Assuming the record contains N fields, the record format looks ** like this: ** ** ------------------------------------------------------------------------ ** | hdr-size | type 0 | type 1 | ... | type N-1 | data0 | ... | data N-1 | |
| ︙ | ︙ | |||
2593 2594 2595 2596 2597 2598 2599 | assert( pOp->p3<pOp->p1 || pOp->p3>=pOp->p1+pOp->p2 ); pOut = &aMem[pOp->p3]; memAboutToChange(p, pOut); /* Loop through the elements that will make up the record to figure ** out how much space is required for the new record. */ | | > > | > > | > > | 2594 2595 2596 2597 2598 2599 2600 2601 2602 2603 2604 2605 2606 2607 2608 2609 2610 2611 2612 2613 2614 2615 2616 2617 2618 2619 2620 2621 2622 2623 2624 2625 2626 2627 2628 2629 2630 2631 2632 2633 2634 2635 |
assert( pOp->p3<pOp->p1 || pOp->p3>=pOp->p1+pOp->p2 );
pOut = &aMem[pOp->p3];
memAboutToChange(p, pOut);
/* Loop through the elements that will make up the record to figure
** out how much space is required for the new record.
*/
assert( pData0<=pLast );
pRec = pData0;
do{
assert( memIsValid(pRec) );
if( zAffinity ){
applyAffinity(pRec, zAffinity[pRec-pData0], encoding);
}
if( (pRec->flags&MEM_Zero)!=0 && pRec->n>0 ){
sqlite3VdbeMemExpandBlob(pRec);
}
serial_type = sqlite3VdbeSerialType(pRec, file_format);
len = sqlite3VdbeSerialTypeLen(serial_type);
nData += len;
testcase( serial_type==127 );
testcase( serial_type==128 );
nHdr += serial_type<=127 ? 1 : sqlite3VarintLen(serial_type);
if( pRec->flags & MEM_Zero ){
/* Only pure zero-filled BLOBs can be input to this Opcode.
** We do not allow blobs with a prefix and a zero-filled tail. */
nZero += pRec->u.nZero;
}else if( len ){
nZero = 0;
}
}while( (++pRec)<=pLast );
/* Add the initial header varint and total the size */
testcase( nHdr==126 );
testcase( nHdr==127 );
if( nHdr<=126 ){
/* The common case */
nHdr += 1;
}else{
/* Rare case of a really large header */
nVarint = sqlite3VarintLen(nHdr);
nHdr += nVarint;
|
| ︙ | ︙ | |||
2641 2642 2643 2644 2645 2646 2647 |
if( sqlite3VdbeMemGrow(pOut, (int)nByte, 0) ){
goto no_mem;
}
zNewRecord = (u8 *)pOut->z;
/* Write the record */
i = putVarint32(zNewRecord, nHdr);
| > | > > < < | < > | > | 2648 2649 2650 2651 2652 2653 2654 2655 2656 2657 2658 2659 2660 2661 2662 2663 2664 2665 2666 2667 2668 2669 2670 2671 |
if( sqlite3VdbeMemGrow(pOut, (int)nByte, 0) ){
goto no_mem;
}
zNewRecord = (u8 *)pOut->z;
/* Write the record */
i = putVarint32(zNewRecord, nHdr);
j = nHdr;
assert( pData0<=pLast );
pRec = pData0;
do{
serial_type = sqlite3VdbeSerialType(pRec, file_format);
i += putVarint32(&zNewRecord[i], serial_type); /* serial type */
j += sqlite3VdbeSerialPut(&zNewRecord[j], (int)(nByte-j), pRec,file_format);
}while( (++pRec)<=pLast );
assert( i==nHdr );
assert( j==nByte );
assert( pOp->p3>0 && pOp->p3<=(p->nMem-p->nCursor) );
pOut->n = (int)nByte;
pOut->flags = MEM_Blob | MEM_Dyn;
pOut->xDel = 0;
if( nZero ){
pOut->u.nZero = nZero;
|
| ︙ | ︙ |