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Overview
Comment: | Reduce the CPU load imposed by sqlit3VdbeCursorMoveto() by factoring out some of its functions and by avoiding unnecessary calls. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA1: |
c2799aece17d347c64217a0e407bb10e |
User & Date: | drh 2014-10-13 16:02:20.134 |
Context
2014-10-13
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17:42 | Three small optimizations to vdbeaux.c. (check-in: 04892f8ba6 user: drh tags: trunk) | |
16:02 | Reduce the CPU load imposed by sqlit3VdbeCursorMoveto() by factoring out some of its functions and by avoiding unnecessary calls. (check-in: c2799aece1 user: drh tags: trunk) | |
13:00 | Remove the OPFLAG_CLEARCACHE flag from OP_Column. In its place, change the P3 parameter of OP_SorterData to be the index of the pseudo-table cursor whose record header cache is to be cleared. This gives a small size reduction and performance increase. (check-in: 20062f4942 user: drh tags: trunk) | |
Changes
Changes to src/btree.c.
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772 773 774 775 776 777 778 | ** ** Calling this routine with a NULL cursor pointer returns false. ** ** Use the separate sqlite3BtreeCursorRestore() routine to restore a cursor ** back to where it ought to be if this routine returns true. */ int sqlite3BtreeCursorHasMoved(BtCursor *pCur){ | | | 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 | ** ** Calling this routine with a NULL cursor pointer returns false. ** ** Use the separate sqlite3BtreeCursorRestore() routine to restore a cursor ** back to where it ought to be if this routine returns true. */ int sqlite3BtreeCursorHasMoved(BtCursor *pCur){ return pCur->eState!=CURSOR_VALID; } /* ** This routine restores a cursor back to its original position after it ** has been moved by some outside activity (such as a btree rebalance or ** a row having been deleted out from under the cursor). ** |
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Changes to src/vdbe.c.
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4309 4310 4311 4312 4313 4314 4315 | assert( pC->isTable || pOp->opcode!=OP_RowData ); assert( pC->isTable==0 || pOp->opcode==OP_RowData ); assert( pC!=0 ); assert( pC->nullRow==0 ); assert( pC->pseudoTableReg==0 ); assert( pC->pCursor!=0 ); pCrsr = pC->pCursor; | < > > > | < > > | > | 4309 4310 4311 4312 4313 4314 4315 4316 4317 4318 4319 4320 4321 4322 4323 4324 4325 4326 4327 4328 4329 4330 4331 4332 4333 4334 4335 4336 | assert( pC->isTable || pOp->opcode!=OP_RowData ); assert( pC->isTable==0 || pOp->opcode==OP_RowData ); assert( pC!=0 ); assert( pC->nullRow==0 ); assert( pC->pseudoTableReg==0 ); assert( pC->pCursor!=0 ); pCrsr = pC->pCursor; /* The OP_RowKey and OP_RowData opcodes always follow OP_NotExists or ** OP_Rewind/Op_Next with no intervening instructions that might invalidate ** the cursor. If this where not the case, on of the following assert()s ** would fail. Should this ever change (because of changes in the code ** generator) then the fix would be to insert a call to ** sqlite3VdbeCursorMoveto(). */ assert( pC->deferredMoveto==0 ); assert( sqlite3BtreeCursorIsValid(pCrsr) ); #if 0 /* Not required due to the previous to assert() statements */ rc = sqlite3VdbeCursorMoveto(pC); if( rc!=SQLITE_OK ) goto abort_due_to_error; #endif if( pC->isTable==0 ){ assert( !pC->isTable ); VVA_ONLY(rc =) sqlite3BtreeKeySize(pCrsr, &n64); assert( rc==SQLITE_OK ); /* True because of CursorMoveto() call above */ if( n64>db->aLimit[SQLITE_LIMIT_LENGTH] ){ goto too_big; |
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4387 4388 4389 4390 4391 4392 4393 | pModule = pVtab->pModule; assert( pModule->xRowid ); rc = pModule->xRowid(pC->pVtabCursor, &v); sqlite3VtabImportErrmsg(p, pVtab); #endif /* SQLITE_OMIT_VIRTUALTABLE */ }else{ assert( pC->pCursor!=0 ); | | | | 4391 4392 4393 4394 4395 4396 4397 4398 4399 4400 4401 4402 4403 4404 4405 4406 4407 4408 | pModule = pVtab->pModule; assert( pModule->xRowid ); rc = pModule->xRowid(pC->pVtabCursor, &v); sqlite3VtabImportErrmsg(p, pVtab); #endif /* SQLITE_OMIT_VIRTUALTABLE */ }else{ assert( pC->pCursor!=0 ); rc = sqlite3VdbeCursorRestore(pC); if( rc ) goto abort_due_to_error; rc = sqlite3BtreeKeySize(pC->pCursor, &v); assert( rc==SQLITE_OK ); /* Always so because of CursorRestore() above */ } pOut->u.i = v; break; } /* Opcode: NullRow P1 * * * * ** |
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4748 4749 4750 4751 4752 4753 4754 | assert( pOp->p1>=0 && pOp->p1<p->nCursor ); pC = p->apCsr[pOp->p1]; assert( pC!=0 ); pCrsr = pC->pCursor; assert( pCrsr!=0 ); pOut->flags = MEM_Null; | > > > > > > > | | | < | 4752 4753 4754 4755 4756 4757 4758 4759 4760 4761 4762 4763 4764 4765 4766 4767 4768 4769 4770 4771 4772 4773 4774 4775 | assert( pOp->p1>=0 && pOp->p1<p->nCursor ); pC = p->apCsr[pOp->p1]; assert( pC!=0 ); pCrsr = pC->pCursor; assert( pCrsr!=0 ); pOut->flags = MEM_Null; assert( pC->isTable==0 ); assert( pC->deferredMoveto==0 ); /* sqlite3VbeCursorRestore() can only fail if the record has been deleted ** out from under the cursor. That will never happend for an IdxRowid ** opcode, hence the NEVER() arround the check of the return value. */ rc = sqlite3VdbeCursorRestore(pC); if( NEVER(rc!=SQLITE_OK) ) goto abort_due_to_error; if( !pC->nullRow ){ rowid = 0; /* Not needed. Only used to silence a warning. */ rc = sqlite3VdbeIdxRowid(db, pCrsr, &rowid); if( rc!=SQLITE_OK ){ goto abort_due_to_error; } pOut->u.i = rowid; |
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Changes to src/vdbeInt.h.
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379 380 381 382 383 384 385 386 387 388 389 390 391 392 | /* ** Function prototypes */ void sqlite3VdbeFreeCursor(Vdbe *, VdbeCursor*); void sqliteVdbePopStack(Vdbe*,int); int sqlite3VdbeCursorMoveto(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*); | > | 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 | /* ** Function prototypes */ void sqlite3VdbeFreeCursor(Vdbe *, VdbeCursor*); 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*); |
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Changes to src/vdbeaux.c.
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2739 2740 2741 2742 2743 2744 2745 2746 2747 2748 2749 2750 2751 2752 2753 2754 2755 2756 2757 2758 2759 2760 2761 2762 2763 | assert( p->pCursor!=0 ); assert( sqlite3BtreeCursorHasMoved(p->pCursor) ); rc = sqlite3BtreeCursorRestore(p->pCursor, &isDifferentRow); p->cacheStatus = CACHE_STALE; if( isDifferentRow ) p->nullRow = 1; return rc; } /* ** Make sure the cursor p is ready to read or write the row to which it ** was last positioned. Return an error code if an OOM fault or I/O error ** prevents us from positioning the cursor to its correct position. ** ** If a MoveTo operation is pending on the given cursor, then do that ** MoveTo now. If no move is pending, check to see if the row has been ** deleted out from under the cursor and if it has, mark the row as ** a NULL row. ** ** If the cursor is already pointing to the correct row and that row has ** not been deleted out from under the cursor, then this routine is a no-op. */ int sqlite3VdbeCursorMoveto(VdbeCursor *p){ if( p->deferredMoveto ){ return handleDeferredMoveto(p); } | > > > > > > > > > > > | | 2739 2740 2741 2742 2743 2744 2745 2746 2747 2748 2749 2750 2751 2752 2753 2754 2755 2756 2757 2758 2759 2760 2761 2762 2763 2764 2765 2766 2767 2768 2769 2770 2771 2772 2773 2774 2775 2776 2777 2778 2779 2780 2781 2782 | assert( p->pCursor!=0 ); assert( sqlite3BtreeCursorHasMoved(p->pCursor) ); rc = sqlite3BtreeCursorRestore(p->pCursor, &isDifferentRow); p->cacheStatus = CACHE_STALE; if( isDifferentRow ) p->nullRow = 1; return rc; } /* ** Check to ensure that the cursor is valid. Restore the cursor ** if need be. Return any I/O error from the restore operation. */ int sqlite3VdbeCursorRestore(VdbeCursor *p){ if( sqlite3BtreeCursorHasMoved(p->pCursor) ){ return handleMovedCursor(p); } return SQLITE_OK; } /* ** Make sure the cursor p is ready to read or write the row to which it ** was last positioned. Return an error code if an OOM fault or I/O error ** prevents us from positioning the cursor to its correct position. ** ** If a MoveTo operation is pending on the given cursor, then do that ** MoveTo now. If no move is pending, check to see if the row has been ** deleted out from under the cursor and if it has, mark the row as ** a NULL row. ** ** If the cursor is already pointing to the correct row and that row has ** not been deleted out from under the cursor, then this routine is a no-op. */ int sqlite3VdbeCursorMoveto(VdbeCursor *p){ if( p->deferredMoveto ){ return handleDeferredMoveto(p); } if( p->pCursor && sqlite3BtreeCursorHasMoved(p->pCursor) ){ return handleMovedCursor(p); } return SQLITE_OK; } /* ** The following functions: |
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