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Overview
| Comment: | Remove the use of 64-bit math in the offset computations of the OP_Column opcode for a small performance improvement. |
|---|---|
| Downloads: | Tarball | ZIP archive |
| Timelines: | family | ancestors | descendants | both | trunk |
| Files: | files | file ages | folders |
| SHA1: |
61a2c8d4d64c28119e9f06eb42f9c043 |
| User & Date: | drh 2010-02-05 14:12:54.000 |
References
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2010-02-25
| ||
| 01:47 | Start a new branch for release 3.6.22 plus limited enhancements and fixes. This first check-in includes the performance enhancements of check-ins [26cb1df735], [61a2c8d4d6], and [27dc5b1c52] (check-in: 9588259882 user: drh tags: branch-3.6.22) | |
Context
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2010-02-05
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| 16:28 | Avoid truncating non-in-memory sub-journals when releasing a savepoint for a small performance improvement. (check-in: 27dc5b1c52 user: shaneh tags: trunk) | |
| 14:12 | Remove the use of 64-bit math in the offset computations of the OP_Column opcode for a small performance improvement. (check-in: 61a2c8d4d6 user: drh tags: trunk) | |
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2010-02-04
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| 17:38 | Fix a performance glitch that appears for large transactions. (check-in: 26cb1df735 user: drh tags: trunk) | |
Changes
Changes to src/vdbe.c.
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2064 2065 2066 2067 2068 2069 2070 | int i; /* Loop counter */ char *zData; /* Part of the record being decoded */ Mem *pDest; /* Where to write the extracted value */ Mem sMem; /* For storing the record being decoded */ u8 *zIdx; /* Index into header */ u8 *zEndHdr; /* Pointer to first byte after the header */ u32 offset; /* Offset into the data */ | | | 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 | int i; /* Loop counter */ char *zData; /* Part of the record being decoded */ Mem *pDest; /* Where to write the extracted value */ Mem sMem; /* For storing the record being decoded */ u8 *zIdx; /* Index into header */ u8 *zEndHdr; /* Pointer to first byte after the header */ u32 offset; /* Offset into the data */ u32 szField; /* Number of bytes in the content of a field */ int szHdr; /* Size of the header size field at start of record */ int avail; /* Number of bytes of available data */ Mem *pReg; /* PseudoTable input register */ p1 = pOp->p1; p2 = pOp->p2; |
| ︙ | ︙ | |||
2239 2240 2241 2242 2243 2244 2245 |
zIdx = (u8 *)&zData[szHdr];
/* Scan the header and use it to fill in the aType[] and aOffset[]
** arrays. aType[i] will contain the type integer for the i-th
** column and aOffset[i] will contain the offset from the beginning
** of the record to the start of the data for the i-th column
*/
| < | | > > > > > | | | 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 |
zIdx = (u8 *)&zData[szHdr];
/* Scan the header and use it to fill in the aType[] and aOffset[]
** arrays. aType[i] will contain the type integer for the i-th
** column and aOffset[i] will contain the offset from the beginning
** of the record to the start of the data for the i-th column
*/
for(i=0; i<nField; i++){
if( zIdx<zEndHdr ){
aOffset[i] = offset;
zIdx += getVarint32(zIdx, aType[i]);
szField = sqlite3VdbeSerialTypeLen(aType[i]);
offset += szField;
if( offset<szField ){ /* True if offset overflows */
zIdx = &zEndHdr[1]; /* Forces SQLITE_CORRUPT return below */
break;
}
}else{
/* If i is less that nField, then there are less fields in this
** record than SetNumColumns indicated there are columns in the
** table. Set the offset for any extra columns not present in
** the record to 0. This tells code below to store a NULL
** instead of deserializing a value from the record.
*/
aOffset[i] = 0;
}
}
sqlite3VdbeMemRelease(&sMem);
sMem.flags = MEM_Null;
/* If we have read more header data than was contained in the header,
** or if the end of the last field appears to be past the end of the
** record, or if the end of the last field appears to be before the end
** of the record (when all fields present), then we must be dealing
** with a corrupt database.
*/
if( (zIdx > zEndHdr) || (offset > payloadSize)
|| (zIdx==zEndHdr && offset!=payloadSize) ){
rc = SQLITE_CORRUPT_BKPT;
goto op_column_out;
}
}
/* Get the column information. If aOffset[p2] is non-zero, then
** deserialize the value from the record. If aOffset[p2] is zero,
|
| ︙ | ︙ |