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Performance optimization for the OP_Column opcode.

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FossilOrigin-Name: 076be5474df628bbbfd2b645adba30e1e093acd0
This commit is contained in:
drh
2015-10-15 21:30:24 +00:00
parent ce78bc6e7e
commit c6ce388301
3 changed files with 15 additions and 18 deletions
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19
src/vdbe.c
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@@ -2368,6 +2368,7 @@ case OP_Column: {
const u8 *zHdr; /* Next unparsed byte of the header */
const u8 *zEndHdr; /* Pointer to first byte after the header */
u32 offset; /* Offset into the data */
u64 offset64; /* 64-bit offset */
u32 szField; /* Number of bytes in the content of a field */
u32 avail; /* Number of bytes of available data */
u32 t; /* A type code from the record header */
@@ -2494,7 +2495,7 @@ case OP_Column: {
/* Fill in pC->aType[i] and aOffset[i] values through the p2-th field. */
i = pC->nHdrParsed;
offset = aOffset[i];
offset64 = aOffset[i];
zHdr = zData + pC->iHdrOffset;
zEndHdr = zData + aOffset[0];
assert( i<=p2 && zHdr<zEndHdr );
@@ -2507,13 +2508,9 @@ case OP_Column: {
}
pC->aType[i] = t;
szField = sqlite3VdbeSerialTypeLen(t);
offset += szField;
if( offset<szField ){ /* True if offset overflows */
zHdr = &zEndHdr[1]; /* Forces SQLITE_CORRUPT return below */
break;
}
offset64 += szField;
i++;
aOffset[i] = offset;
aOffset[i] = (u32)(offset64 & 0xffffffff);
}while( i<=p2 && zHdr<zEndHdr );
pC->nHdrParsed = i;
pC->iHdrOffset = (u32)(zHdr - zData);
@@ -2526,12 +2523,12 @@ case OP_Column: {
** (1) the bytes of the header extend past the declared header size
** (zHdr>zEndHdr)
** (2) the entire header was used but not all data was used
** (zHdr==zEndHdr && offset!=pC->payloadSize)
** (zHdr==zEndHdr && offset64!=pC->payloadSize)
** (3) the end of the data extends beyond the end of the record.
** (offset > pC->payloadSize)
** (offset64 > pC->payloadSize)
*/
if( (zHdr>=zEndHdr && (zHdr>zEndHdr || offset!=pC->payloadSize))
|| (offset > pC->payloadSize)
if( (zHdr>=zEndHdr && (zHdr>zEndHdr || offset64!=pC->payloadSize))
|| (offset64 > pC->payloadSize)
){
rc = SQLITE_CORRUPT_BKPT;
goto op_column_error;