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Overview
| Comment: | Simplifications to blobSeekToRow(). |
|---|---|
| Downloads: | Tarball | ZIP archive | SQL archive |
| Timelines: | family | ancestors | descendants | both | micro-optimizations |
| Files: | files | file ages | folders |
| SHA1: |
495ea824093ff535734c22c3115384c0 |
| User & Date: | drh 2017-01-31 19:02:15 |
Context
|
2017-01-31
| ||
| 19:10 | Very small performance improvements and size reductions in sqlite3VdbeExec() and blobSeekToRow(). (check-in: 85dddf2b user: drh tags: trunk) | |
| 19:02 | Simplifications to blobSeekToRow(). (Closed-Leaf check-in: 495ea824 user: drh tags: micro-optimizations) | |
| 16:49 | Remove a C99-style comment. Fixes to the kvtest-speed.sh script. (check-in: 91eb6b62 user: drh tags: micro-optimizations) | |
Changes
Changes to src/vdbeblob.c.
51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 |
** calls to sqlite3_blob_read(), blob_write() or blob_reopen() will
** immediately return SQLITE_ABORT.
*/
static int blobSeekToRow(Incrblob *p, sqlite3_int64 iRow, char **pzErr){
int rc; /* Error code */
char *zErr = 0; /* Error message */
Vdbe *v = (Vdbe *)p->pStmt;
sqlite3 *db = v->db;
/* Set the value of register r[1] in the SQL statement to integer iRow.
** This is done directly as a performance optimization
*/
v->aMem[1].flags = MEM_Int;
v->aMem[1].u.i = iRow;
/* If the statement has been run before (and is paused at the OP_ResultRow)
** then back it up to the point where it does the OP_SeekRowid. This could
** have been down with an extra OP_Goto, but simply setting the program
** counter is faster. */
if( v->pc>3 ){
v->pc = 3;
db->nVdbeExec++;
rc = sqlite3VdbeExec((Vdbe*)p->pStmt);
db->nVdbeExec--;
}else{
rc = sqlite3_step(p->pStmt);
}
if( rc==SQLITE_ROW ){
VdbeCursor *pC = v->apCsr[0];
u32 type = pC->nHdrParsed>p->iCol ? pC->aType[p->iCol] : 0;
testcase( pC->nHdrParsed==p->iCol );
|
< < | < |
51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 |
** calls to sqlite3_blob_read(), blob_write() or blob_reopen() will
** immediately return SQLITE_ABORT.
*/
static int blobSeekToRow(Incrblob *p, sqlite3_int64 iRow, char **pzErr){
int rc; /* Error code */
char *zErr = 0; /* Error message */
Vdbe *v = (Vdbe *)p->pStmt;
/* Set the value of register r[1] in the SQL statement to integer iRow.
** This is done directly as a performance optimization
*/
v->aMem[1].flags = MEM_Int;
v->aMem[1].u.i = iRow;
/* If the statement has been run before (and is paused at the OP_ResultRow)
** then back it up to the point where it does the OP_SeekRowid. This could
** have been down with an extra OP_Goto, but simply setting the program
** counter is faster. */
if( v->pc>3 ){
v->pc = 3;
rc = sqlite3VdbeExec(v);
}else{
rc = sqlite3_step(p->pStmt);
}
if( rc==SQLITE_ROW ){
VdbeCursor *pC = v->apCsr[0];
u32 type = pC->nHdrParsed>p->iCol ? pC->aType[p->iCol] : 0;
testcase( pC->nHdrParsed==p->iCol );
|