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Overview
Comment: | Factor out the code that generates a co-routine for evaluating the SELECT on the RHS of an INSERT statement so that the same code can potentially be reused in other places. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA1: |
a93ee09cdc15987848bf9023e69892ce |
User & Date: | drh 2012-09-15 13:29:23.328 |
Context
2012-09-15
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13:39 | Make sure the name of rollback journal files are double-zero terminated when they are passed into the VFS. (check-in: 8711a8447d user: drh tags: trunk) | |
13:29 | Factor out the code that generates a co-routine for evaluating the SELECT on the RHS of an INSERT statement so that the same code can potentially be reused in other places. (check-in: a93ee09cdc user: drh tags: trunk) | |
2012-09-13
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19:59 | Improved alignment of fields in the Expr object gives an 8-byte size reduction on 64-bit machines. (check-in: 6b252a0d1a user: drh tags: trunk) | |
Changes
Changes to src/insert.c.
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315 316 317 318 319 320 321 322 323 324 325 326 327 328 | ** If SQLITE_OMIT_AUTOINCREMENT is defined, then the three routines ** above are all no-ops */ # define autoIncBegin(A,B,C) (0) # define autoIncStep(A,B,C) #endif /* SQLITE_OMIT_AUTOINCREMENT */ /* Forward declaration */ static int xferOptimization( Parse *pParse, /* Parser context */ Table *pDest, /* The table we are inserting into */ Select *pSelect, /* A SELECT statement to use as the data source */ int onError, /* How to handle constraint errors */ | > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > | 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 | ** If SQLITE_OMIT_AUTOINCREMENT is defined, then the three routines ** above are all no-ops */ # define autoIncBegin(A,B,C) (0) # define autoIncStep(A,B,C) #endif /* SQLITE_OMIT_AUTOINCREMENT */ /* ** Generate code for a co-routine that will evaluate a subquery one ** row at a time. ** ** The pSelect parameter is the subquery that the co-routine will evaluation. ** Information about the location of co-routine and the registers it will use ** is returned by filling in the pDest object. ** ** Registers are allocated as follows: ** ** pDest->iSDParm The register holding the next entry-point of the ** co-routine. Run the co-routine to its next breakpoint ** by calling "OP_Yield $X" where $X is pDest->iSDParm. ** ** pDest->iSDParm+1 The register holding the "completed" flag for the ** co-routine. This register is 0 if the previous Yield ** generated a new result row, or 1 if the subquery ** has completed. If the Yield is called again ** after this register becomes 1, then the VDBE will ** halt with an SQLITE_INTERNAL error. ** ** pDest->iSdst First result register. ** ** pDest->nSdst Number of result registers. ** ** This routine handles all of the register allocation and fills in the ** pDest structure appropriately. ** ** Here is a schematic of the generated code assuming that X is the ** co-routine entry-point register reg[pDest->iSDParm], that EOF is the ** completed flag reg[pDest->iSDParm+1], and R and S are the range of ** registers that hold the result set, reg[pDest->iSdst] through ** reg[pDest->iSdst+pDest->nSdst-1]: ** ** X <- A ** EOF <- 0 ** goto B ** A: setup for the SELECT ** loop rows in the SELECT ** load results into registers R..S ** yield X ** end loop ** cleanup after the SELECT ** EOF <- 1 ** yield X ** halt-error ** B: ** ** To use this subroutine, the caller generates code as follows: ** ** [ Co-routine generated by this subroutine, shown above ] ** S: yield X ** if EOF goto E ** if skip this row, goto C ** if terminate loop, goto E ** deal with this row ** C: goto S ** E: */ int sqlite3CodeCoroutine(Parse *pParse, Select *pSelect, SelectDest *pDest){ int regYield; /* Register holding co-routine entry-point */ int regEof; /* Register holding co-routine completion flag */ int addrTop; /* Top of the co-routine */ int j1; /* Jump instruction */ int rc; /* Result code */ Vdbe *v; /* VDBE under construction */ regYield = ++pParse->nMem; regEof = ++pParse->nMem; v = sqlite3GetVdbe(pParse); addrTop = sqlite3VdbeCurrentAddr(v); sqlite3VdbeAddOp2(v, OP_Integer, addrTop+2, regYield); /* X <- A */ VdbeComment((v, "Co-routine entry point")); sqlite3VdbeAddOp2(v, OP_Integer, 0, regEof); /* EOF <- 0 */ VdbeComment((v, "Co-routine completion flag")); sqlite3SelectDestInit(pDest, SRT_Coroutine, regYield); j1 = sqlite3VdbeAddOp2(v, OP_Goto, 0, 0); rc = sqlite3Select(pParse, pSelect, pDest); assert( pParse->nErr==0 || rc ); if( pParse->db->mallocFailed && rc==SQLITE_OK ) rc = SQLITE_NOMEM; if( rc ) return rc; sqlite3VdbeAddOp2(v, OP_Integer, 1, regEof); /* EOF <- 1 */ sqlite3VdbeAddOp1(v, OP_Yield, regYield); /* yield X */ sqlite3VdbeAddOp2(v, OP_Halt, SQLITE_INTERNAL, OE_Abort); VdbeComment((v, "End of coroutine")); sqlite3VdbeJumpHere(v, j1); /* label B: */ return rc; } /* Forward declaration */ static int xferOptimization( Parse *pParse, /* Parser context */ Table *pDest, /* The table we are inserting into */ Select *pSelect, /* A SELECT statement to use as the data source */ int onError, /* How to handle constraint errors */ |
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564 565 566 567 568 569 570 | /* Figure out how many columns of data are supplied. If the data ** is coming from a SELECT statement, then generate a co-routine that ** produces a single row of the SELECT on each invocation. The ** co-routine is the common header to the 3rd and 4th templates. */ if( pSelect ){ | | < < < < < < < < < < < < < < < < < | < < < < < < < < < < < < < < < | < < | | < < < < < | | 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 | /* Figure out how many columns of data are supplied. If the data ** is coming from a SELECT statement, then generate a co-routine that ** produces a single row of the SELECT on each invocation. The ** co-routine is the common header to the 3rd and 4th templates. */ if( pSelect ){ /* Data is coming from a SELECT. Generate a co-routine to run that ** SELECT. */ int rc = sqlite3CodeCoroutine(pParse, pSelect, &dest); if( rc ) goto insert_cleanup; regEof = dest.iSDParm + 1; regFromSelect = dest.iSdst; assert( pSelect->pEList ); nColumn = pSelect->pEList->nExpr; assert( dest.nSdst==nColumn ); /* Set useTempTable to TRUE if the result of the SELECT statement ** should be written into a temporary table (template 4). Set to |
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Changes to src/sqliteInt.h.
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2776 2777 2778 2779 2780 2781 2782 2783 2784 2785 2786 2787 2788 2789 | #ifndef SQLITE_OMIT_AUTOINCREMENT void sqlite3AutoincrementBegin(Parse *pParse); void sqlite3AutoincrementEnd(Parse *pParse); #else # define sqlite3AutoincrementBegin(X) # define sqlite3AutoincrementEnd(X) #endif void sqlite3Insert(Parse*, SrcList*, ExprList*, Select*, IdList*, int); void *sqlite3ArrayAllocate(sqlite3*,void*,int,int*,int*); IdList *sqlite3IdListAppend(sqlite3*, IdList*, Token*); int sqlite3IdListIndex(IdList*,const char*); SrcList *sqlite3SrcListEnlarge(sqlite3*, SrcList*, int, int); SrcList *sqlite3SrcListAppend(sqlite3*, SrcList*, Token*, Token*); SrcList *sqlite3SrcListAppendFromTerm(Parse*, SrcList*, Token*, Token*, | > | 2776 2777 2778 2779 2780 2781 2782 2783 2784 2785 2786 2787 2788 2789 2790 | #ifndef SQLITE_OMIT_AUTOINCREMENT void sqlite3AutoincrementBegin(Parse *pParse); void sqlite3AutoincrementEnd(Parse *pParse); #else # define sqlite3AutoincrementBegin(X) # define sqlite3AutoincrementEnd(X) #endif int sqlite3CodeCoroutine(Parse*, Select*, SelectDest*); void sqlite3Insert(Parse*, SrcList*, ExprList*, Select*, IdList*, int); void *sqlite3ArrayAllocate(sqlite3*,void*,int,int*,int*); IdList *sqlite3IdListAppend(sqlite3*, IdList*, Token*); int sqlite3IdListIndex(IdList*,const char*); SrcList *sqlite3SrcListEnlarge(sqlite3*, SrcList*, int, int); SrcList *sqlite3SrcListAppend(sqlite3*, SrcList*, Token*, Token*); SrcList *sqlite3SrcListAppendFromTerm(Parse*, SrcList*, Token*, Token*, |
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