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Overview
| Comment: | Use a lookup table to compute the content length for serial types less than 128, for a 1.2% performance improvement. |
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| Downloads: | Tarball | ZIP archive | SQL archive |
| Timelines: | family | ancestors | descendants | both | trunk |
| Files: | files | file ages | folders |
| SHA1: | 3395724814099d28829ef6875ca1ba77d6fe7ffa |
| User & Date: | drh 2015-10-16 14:23:42 |
Context
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2015-10-16
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| 14:54 | Have the sqlite3VdbeSerialType() function go ahead and compute the serial length as well, since it is always needed. This avoids unnecessary calls to sqlite3VdbeSerialTypeLen(). check-in: 2ad72be1 user: drh tags: trunk | |
| 14:23 | Use a lookup table to compute the content length for serial types less than 128, for a 1.2% performance improvement. check-in: 33957248 user: drh tags: trunk | |
| 13:50 | Simplify the OP_Column logic slightly. One very small performance improvement added. check-in: 0114b45d user: drh tags: trunk | |
Changes
Changes to src/vdbe.c.
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Mem *pDest; /* Where to write the extracted value */ Mem sMem; /* For storing the record being decoded */ const u8 *zData; /* Part of the record being decoded */ 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 */ u16 fx; /* pDest->flags value */ Mem *pReg; /* PseudoTable input register */ p2 = pOp->p2; assert( pOp->p3>0 && pOp->p3<=(p->nMem-p->nCursor) ); ................................................................................ offset64 = aOffset[i]; zHdr = zData + pC->iHdrOffset; zEndHdr = zData + aOffset[0]; assert( i<=p2 && zHdr<zEndHdr ); do{ if( (t = zHdr[0])<0x80 ){ zHdr++; }else{ zHdr += sqlite3GetVarint32(zHdr, &t); } pC->aType[i] = t; szField = sqlite3VdbeSerialTypeLen(t); offset64 += szField; i++; aOffset[i] = (u32)(offset64 & 0xffffffff); }while( i<=p2 && zHdr<zEndHdr ); pC->nHdrParsed = i; pC->iHdrOffset = (u32)(zHdr - zData); if( pC->aRow==0 ) sqlite3VdbeMemRelease(&sMem); /* The record is corrupt if any of the following are true: |
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Mem *pDest; /* Where to write the extracted value */ Mem sMem; /* For storing the record being decoded */ const u8 *zData; /* Part of the record being decoded */ 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 avail; /* Number of bytes of available data */ u32 t; /* A type code from the record header */ u16 fx; /* pDest->flags value */ Mem *pReg; /* PseudoTable input register */ p2 = pOp->p2; assert( pOp->p3>0 && pOp->p3<=(p->nMem-p->nCursor) ); ................................................................................ offset64 = aOffset[i]; zHdr = zData + pC->iHdrOffset; zEndHdr = zData + aOffset[0]; assert( i<=p2 && zHdr<zEndHdr ); do{ if( (t = zHdr[0])<0x80 ){ zHdr++; offset64 += sqlite3VdbeOneByteSerialTypeLen(t); }else{ zHdr += sqlite3GetVarint32(zHdr, &t); offset64 += sqlite3VdbeSerialTypeLen(t); } pC->aType[i++] = t; aOffset[i] = (u32)(offset64 & 0xffffffff); }while( i<=p2 && zHdr<zEndHdr ); pC->nHdrParsed = i; pC->iHdrOffset = (u32)(zHdr - zData); if( pC->aRow==0 ) sqlite3VdbeMemRelease(&sMem); /* The record is corrupt if any of the following are true: |
Changes to src/vdbeInt.h.
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void sqliteVdbePopStack(Vdbe*,int); int sqlite3VdbeCursorMoveto(VdbeCursor*); int sqlite3VdbeCursorRestore(VdbeCursor*); #if defined(SQLITE_DEBUG) || defined(VDBE_PROFILE) void sqlite3VdbePrintOp(FILE*, int, Op*); #endif u32 sqlite3VdbeSerialTypeLen(u32); u32 sqlite3VdbeSerialType(Mem*, int); u32 sqlite3VdbeSerialPut(unsigned char*, Mem*, u32); u32 sqlite3VdbeSerialGet(const unsigned char*, u32, Mem*); void sqlite3VdbeDeleteAuxData(Vdbe*, int, int); int sqlite2BtreeKeyCompare(BtCursor *, const void *, int, int, int *); int sqlite3VdbeIdxKeyCompare(sqlite3*,VdbeCursor*,UnpackedRecord*,int*); |
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void sqliteVdbePopStack(Vdbe*,int);
int sqlite3VdbeCursorMoveto(VdbeCursor*);
int sqlite3VdbeCursorRestore(VdbeCursor*);
#if defined(SQLITE_DEBUG) || defined(VDBE_PROFILE)
void sqlite3VdbePrintOp(FILE*, int, Op*);
#endif
u32 sqlite3VdbeSerialTypeLen(u32);
u8 sqlite3VdbeOneByteSerialTypeLen(u8);
u32 sqlite3VdbeSerialType(Mem*, int);
u32 sqlite3VdbeSerialPut(unsigned char*, Mem*, u32);
u32 sqlite3VdbeSerialGet(const unsigned char*, u32, Mem*);
void sqlite3VdbeDeleteAuxData(Vdbe*, int, int);
int sqlite2BtreeKeyCompare(BtCursor *, const void *, int, int, int *);
int sqlite3VdbeIdxKeyCompare(sqlite3*,VdbeCursor*,UnpackedRecord*,int*);
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Changes to src/vdbeaux.c.
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if( flags & MEM_Zero ){
n += pMem->u.nZero;
}
return ((n*2) + 12 + ((flags&MEM_Str)!=0));
}
/*
** The sizes for serial types less than 12
*/
static const u8 sqlite3SmallTypeSizes[] = {
0, 1, 2, 3, 4, 6, 8, 8, 0, 0, 0, 0
};
/*
** Return the length of the data corresponding to the supplied serial-type.
*/
u32 sqlite3VdbeSerialTypeLen(u32 serial_type){
if( serial_type>=12 ){
return (serial_type-12)/2;
}else{
return sqlite3SmallTypeSizes[serial_type];
}
}
/*
** If we are on an architecture with mixed-endian floating
** points (ex: ARM7) then swap the lower 4 bytes with the
** upper 4 bytes. Return the result.
**
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if( flags & MEM_Zero ){
n += pMem->u.nZero;
}
return ((n*2) + 12 + ((flags&MEM_Str)!=0));
}
/*
** The sizes for serial types less than 128
*/
static const u8 sqlite3SmallTypeSizes[] = {
/* 0 1 2 3 4 5 6 7 8 9 */
/* 0 */ 0, 1, 2, 3, 4, 6, 8, 8, 0, 0,
/* 10 */ 0, 0, 0, 0, 1, 1, 2, 2, 3, 3,
/* 20 */ 4, 4, 5, 5, 6, 6, 7, 7, 8, 8,
/* 30 */ 9, 9, 10, 10, 11, 11, 12, 12, 13, 13,
/* 40 */ 14, 14, 15, 15, 16, 16, 17, 17, 18, 18,
/* 50 */ 19, 19, 20, 20, 21, 21, 22, 22, 23, 23,
/* 60 */ 24, 24, 25, 25, 26, 26, 27, 27, 28, 28,
/* 70 */ 29, 29, 30, 30, 31, 31, 32, 32, 33, 33,
/* 80 */ 34, 34, 35, 35, 36, 36, 37, 37, 38, 38,
/* 90 */ 39, 39, 40, 40, 41, 41, 42, 42, 43, 43,
/* 100 */ 44, 44, 45, 45, 46, 46, 47, 47, 48, 48,
/* 110 */ 49, 49, 50, 50, 51, 51, 52, 52, 53, 53,
/* 120 */ 54, 54, 55, 55, 56, 56, 57, 57
};
/*
** Return the length of the data corresponding to the supplied serial-type.
*/
u32 sqlite3VdbeSerialTypeLen(u32 serial_type){
if( serial_type>=128 ){
return (serial_type-12)/2;
}else{
assert( serial_type<12
|| sqlite3SmallTypeSizes[serial_type]==(serial_type - 12)/2 );
return sqlite3SmallTypeSizes[serial_type];
}
}
u8 sqlite3VdbeOneByteSerialTypeLen(u8 serial_type){
assert( serial_type<128 );
return sqlite3SmallTypeSizes[serial_type];
}
/*
** If we are on an architecture with mixed-endian floating
** points (ex: ARM7) then swap the lower 4 bytes with the
** upper 4 bytes. Return the result.
**
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