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Overview
Comment: | Refactor local object and method names in vdbesort.c so that their names more closely reflect their actual use. |
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SHA1: |
d284e30eb1db144965fa85566e4234e3 |
User & Date: | drh 2014-04-03 02:54:27.677 |
Context
2014-04-03
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14:29 | Fix minor errors causing compilation to fail with SQLITE_MAX_WORKER_THREADS set to a value greater than zero. (check-in: 0561272abf user: dan tags: threads) | |
02:54 | Refactor local object and method names in vdbesort.c so that their names more closely reflect their actual use. (check-in: d284e30eb1 user: drh tags: threads) | |
2014-04-02
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18:58 | Add a big introductory comment to vdbesort.c explaining its operation at a high level. Also adjust some symbolic names and fix other comment issues in that file. (check-in: eef60f1bf5 user: drh tags: threads) | |
Changes
Changes to src/vdbesort.c.
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87 88 89 90 91 92 93 | */ #include "sqliteInt.h" #include "vdbeInt.h" /* ** Private objects used by the sorter */ | | | > | | < | | | | | | | | | | | | < < < < < < | | | | | | | | | | 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 | */ #include "sqliteInt.h" #include "vdbeInt.h" /* ** Private objects used by the sorter */ typedef struct MergeEngine MergeEngine; /* Merge PMAs together */ typedef struct PmaReader PmaReader; /* Incrementally read one PMA */ typedef struct PmaWriter PmaWriter; /* Incrementally write on PMA */ typedef struct SorterRecord SorterRecord; /* A record being sorted */ typedef struct SortSubtask SortSubtask; /* A sub-task in the sort process */ /* ** Candidate values for SortSubtask.eWork */ #define SORT_SUBTASK_SORT 1 /* Sort records on pList */ #define SORT_SUBTASK_TO_PMA 2 /* Xfer pList to Packed-Memory-Array pTemp1 */ #define SORT_SUBTASK_CONS 3 /* Consolidate multiple PMAs */ /* ** Sorting is divided up into smaller subtasks. Each subtask is controlled ** by an instance of this object. A Subtask might run in either the main thread ** or in a background thread. ** ** Exactly VdbeSorter.nTask instances of this object are allocated ** as part of each VdbeSorter object. Instances are never allocated any other ** way. VdbeSorter.nTask is set to the number of worker threads allowed ** (see SQLITE_CONFIG_WORKER_THREADS) plus one (the main thread). ** ** When a background thread is launched to perform work, SortSubtask.bDone ** is set to 0 and the SortSubtask.pTask variable set to point to the ** thread handle. SortSubtask.bDone is set to 1 (to indicate to the main ** thread that joining SortSubtask.pTask will not block) before the thread ** exits. SortSubtask.pTask and bDone are always cleared after the ** background thread has been joined. ** ** One object (specifically, VdbeSorter.aTask[VdbeSorter.nTask-1]) ** is reserved for the foreground thread. ** ** The nature of the work performed is determined by SortSubtask.eWork, ** as follows: ** ** SORT_SUBTASK_SORT: ** Sort the linked list of records at SortSubtask.pList. ** ** SORT_SUBTASK_TO_PMA: ** Sort the linked list of records at SortSubtask.pList, and write ** the results to a new PMA in temp file SortSubtask.pTemp1. Open ** the temp file if it is not already open. ** ** SORT_SUBTASK_CONS: ** Merge existing PMAs until SortSubtask.nConsolidate or fewer ** remain in temp file SortSubtask.pTemp1. */ struct SortSubtask { SQLiteThread *pThread; /* Thread handle, or NULL */ int bDone; /* Set to true by pTask when finished */ sqlite3_vfs *pVfs; /* VFS used to open temporary files */ KeyInfo *pKeyInfo; /* How to compare records */ UnpackedRecord *pUnpacked; /* Space to unpack a record */ int pgsz; /* Main database page size */ u8 eWork; /* One of the SORT_SUBTASK_* constants */ int nConsolidate; /* For SORT_SUBTASK_CONS, max final PMAs */ SorterRecord *pList; /* List of records for pTask to sort */ int nInMemory; /* Expected size of PMA based on pList */ u8 *aListMemory; /* Records memory (or NULL) */ int nPMA; /* Number of PMAs currently in pTemp1 */ i64 iTemp1Off; /* Offset to write to in pTemp1 */ sqlite3_file *pTemp1; /* File to write PMAs to, or NULL */ }; /* ** The MergeEngine object is used to combine two or more smaller PMAs into ** one big PMA using a merge operation. Separate PMAs all need to be ** combined into one big PMA in order to be able to step through the sorted ** records in order. ** ** The aIter[] array contains a PmaReader object for each of the PMAs being ** merged. An aIter[] object either points to a valid key or else is at EOF. ** For the purposes of the paragraphs below, we assume that the array is ** actually N elements in size, where N is the smallest power of 2 greater ** to or equal to the number of PMAs being merged. The extra aIter[] elements ** are treated as if they are empty (always at EOF). ** ** The aTree[] array is also N elements in size. The value of N is stored in ** the MergeEngine.nTree variable. ** ** The final (N/2) elements of aTree[] contain the results of comparing ** pairs of PMA keys together. Element i contains the result of ** comparing aIter[2*i-N] and aIter[2*i-N+1]. Whichever key is smaller, the ** aTree element is set to the index of it. ** ** For the purposes of this comparison, EOF is considered greater than any ** other key value. If the keys are equal (only possible with two EOF ** values), it doesn't matter which index is stored. ** |
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226 227 228 229 230 231 232 | ** ** aTree[] = { X, 0 0, 6 0, 3, 5, 6 } ** ** In other words, each time we advance to the next sorter element, log2(N) ** key comparison operations are required, where N is the number of segments ** being merged (rounded up to the next power of 2). */ | | | | | | | | | > | | | > | | < > > | | | | > | | | | | | | 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 | ** ** aTree[] = { X, 0 0, 6 0, 3, 5, 6 } ** ** In other words, each time we advance to the next sorter element, log2(N) ** key comparison operations are required, where N is the number of segments ** being merged (rounded up to the next power of 2). */ struct MergeEngine { int nTree; /* Used size of aTree/aIter (power of 2) */ int *aTree; /* Current state of incremental merge */ PmaReader *aIter; /* Array of iterators to merge data from */ }; /* ** Main sorter structure. A single instance of this is allocated for each ** sorter cursor created by the VDBE. */ struct VdbeSorter { int nInMemory; /* Current size of pRecord list as PMA */ int mnPmaSize; /* Minimum PMA size, in bytes */ int mxPmaSize; /* Maximum PMA size, in bytes. 0==no limit */ int bUsePMA; /* True if one or more PMAs created */ SorterRecord *pRecord; /* Head of in-memory record list */ MergeEngine *pMerger; /* For final merge of PMAs (by caller) */ u8 *aMemory; /* Block of memory to alloc records from */ int iMemory; /* Offset of first free byte in aMemory */ int nMemory; /* Size of aMemory allocation in bytes */ int iPrev; /* Previous thread used to flush PMA */ int nTask; /* Size of aTask[] array */ SortSubtask aTask[1]; /* One or more subtasks */ }; /* ** An instance of the following object is used to read records out of a ** PMA, in sorted order. The next key to be read is cached in nKey/aKey. ** pFile==0 at EOF. */ struct PmaReader { i64 iReadOff; /* Current read offset */ i64 iEof; /* 1 byte past EOF for this iterator */ int nAlloc; /* Bytes of space at aAlloc */ int nKey; /* Number of bytes in key */ sqlite3_file *pFile; /* File iterator is reading from */ u8 *aAlloc; /* Allocated space */ u8 *aKey; /* Pointer to current key */ u8 *aBuffer; /* Current read buffer */ int nBuffer; /* Size of read buffer in bytes */ u8 *aMap; /* Pointer to mapping of entire file */ }; /* ** An instance of this object is used for writing a PMA. ** ** The PMA is written one record at a time. Each record is of an arbitrary ** size. But I/O is more efficient if it occurs in page-sized blocks where ** each block is aligned on a page boundary. This object caches writes to ** the PMA so that aligned, page-size blocks are written. */ struct PmaWriter { int eFWErr; /* Non-zero if in an error state */ u8 *aBuffer; /* Pointer to write buffer */ int nBuffer; /* Size of write buffer in bytes */ int iBufStart; /* First byte of buffer to write */ int iBufEnd; /* Last byte of buffer to write */ i64 iWriteOff; /* Offset of start of buffer in file */ sqlite3_file *pFile; /* File to write to */ }; /* ** This object is the header on a single record while that record is being ** held in memory and prior to being written out as part of a PMA. ** ** How the linked list is connected depends on how memory is being managed ** by this module. If using a separate allocation for each in-memory record ** (VdbeSorter.aMemory==0), then the list is always connected using the ** SorterRecord.u.pNext pointers. ** ** Or, if using the single large allocation method (VdbeSorter.aMemory!=0), ** then while records are being accumulated the list is linked using the ** SorterRecord.u.iNext offset. This is because the aMemory[] array may ** be sqlite3Realloc()ed while records are being accumulated. Once the VM ** has finished passing records to the sorter, or when the in-memory buffer ** is full, the list is sorted. As part of the sorting process, it is ** converted to use the SorterRecord.u.pNext pointers. See function ** vdbeSorterSort() for details. */ struct SorterRecord { int nVal; /* Size of the record in bytes */ union { SorterRecord *pNext; /* Pointer to next record in list */ int iNext; /* Offset within aMemory of next record */ } u; /* The data for the record immediately follows this header */ }; /* Return a pointer to the buffer containing the record data for SorterRecord ** object p. Should be used as if: ** ** void *SRVAL(SorterRecord *p) { return (void*)&p[1]; } */ #define SRVAL(p) ((void*)((SorterRecord*)(p) + 1)) /* The minimum PMA size is set to this value multiplied by the database ** page size in bytes. */ #define SORTER_MIN_WORKING 10 /* Maximum number of PMAs that a single MergeEngine can merge */ #define SORTER_MAX_MERGE_COUNT 16 /* ** Free all memory belonging to the PmaReader object passed as the second ** argument. All structure fields are set to zero before returning. */ static void vdbePmaReaderClear(PmaReader *pIter){ sqlite3_free(pIter->aAlloc); sqlite3_free(pIter->aBuffer); if( pIter->aMap ) sqlite3OsUnfetch(pIter->pFile, 0, pIter->aMap); memset(pIter, 0, sizeof(PmaReader)); } /* ** Read nByte bytes of data from the stream of data iterated by object p. ** If successful, set *ppOut to point to a buffer containing the data ** and return SQLITE_OK. Otherwise, if an error occurs, return an SQLite ** error code. ** ** The buffer indicated by *ppOut may only be considered valid until the ** next call to this function. */ static int vdbePmaReadBlob( PmaReader *p, /* Iterator */ int nByte, /* Bytes of data to read */ u8 **ppOut /* OUT: Pointer to buffer containing data */ ){ int iBuf; /* Offset within buffer to read from */ int nAvail; /* Bytes of data available in buffer */ if( p->aMap ){ |
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415 416 417 418 419 420 421 | memcpy(p->aAlloc, &p->aBuffer[iBuf], nAvail); p->iReadOff += nAvail; nRem = nByte - nAvail; /* The following loop copies up to p->nBuffer bytes per iteration into ** the p->aAlloc[] buffer. */ while( nRem>0 ){ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | > > > > | | 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 | memcpy(p->aAlloc, &p->aBuffer[iBuf], nAvail); p->iReadOff += nAvail; nRem = nByte - nAvail; /* The following loop copies up to p->nBuffer bytes per iteration into ** the p->aAlloc[] buffer. */ while( nRem>0 ){ int rc; /* vdbePmaReadBlob() return code */ int nCopy; /* Number of bytes to copy */ u8 *aNext; /* Pointer to buffer to copy data from */ nCopy = nRem; if( nRem>p->nBuffer ) nCopy = p->nBuffer; rc = vdbePmaReadBlob(p, nCopy, &aNext); if( rc!=SQLITE_OK ) return rc; assert( aNext!=p->aAlloc ); memcpy(&p->aAlloc[nByte - nRem], aNext, nCopy); nRem -= nCopy; } *ppOut = p->aAlloc; } return SQLITE_OK; } /* ** Read a varint from the stream of data accessed by p. Set *pnOut to ** the value read. */ static int vdbePmaReadVarint(PmaReader *p, u64 *pnOut){ int iBuf; if( p->aMap ){ p->iReadOff += sqlite3GetVarint(&p->aMap[p->iReadOff], pnOut); }else{ iBuf = p->iReadOff % p->nBuffer; if( iBuf && (p->nBuffer-iBuf)>=9 ){ p->iReadOff += sqlite3GetVarint(&p->aBuffer[iBuf], pnOut); }else{ u8 aVarint[16], *a; int i = 0, rc; do{ rc = vdbePmaReadBlob(p, 1, &a); if( rc ) return rc; aVarint[(i++)&0xf] = a[0]; }while( (a[0]&0x80)!=0 ); sqlite3GetVarint(aVarint, pnOut); } } return SQLITE_OK; } /* ** Advance iterator pIter to the next key in its PMA. Return SQLITE_OK if ** no error occurs, or an SQLite error code if one does. */ static int vdbePmaReaderNext(PmaReader *pIter){ int rc; /* Return Code */ u64 nRec = 0; /* Size of record in bytes */ if( pIter->iReadOff>=pIter->iEof ){ /* This is an EOF condition */ vdbePmaReaderClear(pIter); return SQLITE_OK; } rc = vdbePmaReadVarint(pIter, &nRec); if( rc==SQLITE_OK ){ pIter->nKey = (int)nRec; rc = vdbePmaReadBlob(pIter, (int)nRec, &pIter->aKey); } return rc; } /* ** Initialize iterator pIter to scan through the PMA stored in file pFile ** starting at offset iStart and ending at offset iEof-1. This function ** leaves the iterator pointing to the first key in the PMA (or EOF if the ** PMA is empty). */ static int vdbePmaReaderInit( SortSubtask *pTask, /* Thread context */ i64 iStart, /* Start offset in pTask->pTemp1 */ PmaReader *pIter, /* Iterator to populate */ i64 *pnByte /* IN/OUT: Increment this value by PMA size */ ){ int rc = SQLITE_OK; int nBuf = pTask->pgsz; void *pMap = 0; /* Mapping of temp file */ assert( pTask->iTemp1Off>iStart ); assert( pIter->aAlloc==0 ); assert( pIter->aBuffer==0 ); pIter->pFile = pTask->pTemp1; pIter->iReadOff = iStart; pIter->nAlloc = 128; pIter->aAlloc = (u8*)sqlite3Malloc(pIter->nAlloc); if( pIter->aAlloc ){ /* Try to xFetch() a mapping of the entire temp file. If this is possible, ** the PMA will be read via the mapping. Otherwise, use xRead(). */ rc = sqlite3OsFetch(pIter->pFile, 0, pTask->iTemp1Off, &pMap); }else{ rc = SQLITE_NOMEM; } if( rc==SQLITE_OK ){ if( pMap ){ pIter->aMap = (u8*)pMap; }else{ pIter->nBuffer = nBuf; pIter->aBuffer = (u8*)sqlite3Malloc(nBuf); if( !pIter->aBuffer ){ rc = SQLITE_NOMEM; }else{ int iBuf = iStart % nBuf; if( iBuf ){ int nRead = nBuf - iBuf; if( (iStart + nRead) > pTask->iTemp1Off ){ nRead = (int)(pTask->iTemp1Off - iStart); } rc = sqlite3OsRead( pTask->pTemp1, &pIter->aBuffer[iBuf], nRead, iStart ); assert( rc!=SQLITE_IOERR_SHORT_READ ); } } } } if( rc==SQLITE_OK ){ u64 nByte; /* Size of PMA in bytes */ pIter->iEof = pTask->iTemp1Off; rc = vdbePmaReadVarint(pIter, &nByte); pIter->iEof = pIter->iReadOff + nByte; *pnByte += nByte; } if( rc==SQLITE_OK ){ rc = vdbePmaReaderNext(pIter); } return rc; } /* ** Compare key1 (buffer pKey1, size nKey1 bytes) with key2 (buffer pKey2, ** size nKey2 bytes). Use (pTask->pKeyInfo) for the collation sequences ** used by the comparison. Return the result of the comparison. ** ** Before returning, object (pTask->pUnpacked) is populated with the ** unpacked version of key2. Or, if pKey2 is passed a NULL pointer, then it ** is assumed that the (pTask->pUnpacked) structure already contains the ** unpacked key to use as key2. ** ** If an OOM error is encountered, (pTask->pUnpacked->error_rc) is set ** to SQLITE_NOMEM. */ static int vdbeSorterCompare( SortSubtask *pTask, /* Subtask context (for pKeyInfo) */ const void *pKey1, int nKey1, /* Left side of comparison */ const void *pKey2, int nKey2 /* Right side of comparison */ ){ UnpackedRecord *r2 = pTask->pUnpacked; if( pKey2 ){ sqlite3VdbeRecordUnpack(pTask->pKeyInfo, nKey2, pKey2, r2); } return sqlite3VdbeRecordCompare(nKey1, pKey1, r2, 0); } /* ** This function is called to compare two iterator keys when merging ** multiple b-tree segments. Parameter iOut is the index of the aTree[] ** value to recalculate. */ static int vdbeSorterDoCompare( SortSubtask *pTask, MergeEngine *pMerger, int iOut ){ int i1; int i2; int iRes; PmaReader *p1; PmaReader *p2; assert( iOut<pMerger->nTree && iOut>0 ); if( iOut>=(pMerger->nTree/2) ){ i1 = (iOut - pMerger->nTree/2) * 2; i2 = i1 + 1; }else{ i1 = pMerger->aTree[iOut*2]; i2 = pMerger->aTree[iOut*2+1]; } p1 = &pMerger->aIter[i1]; p2 = &pMerger->aIter[i2]; if( p1->pFile==0 ){ iRes = i2; }else if( p2->pFile==0 ){ iRes = i1; }else{ int res; assert( pTask->pUnpacked!=0 ); /* allocated in vdbeSortSubtaskMain() */ res = vdbeSorterCompare( pTask, p1->aKey, p1->nKey, p2->aKey, p2->nKey ); if( res<=0 ){ iRes = i1; }else{ iRes = i2; } } pMerger->aTree[iOut] = iRes; return SQLITE_OK; } /* ** Initialize the temporary index cursor just opened as a sorter cursor. */ int sqlite3VdbeSorterInit( sqlite3 *db, /* Database connection (for malloc()) */ int nField, /* Number of key fields in each record */ VdbeCursor *pCsr /* Cursor that holds the new sorter */ ){ int pgsz; /* Page size of main database */ int i; /* Used to iterate through aTask[] */ int mxCache; /* Cache size */ VdbeSorter *pSorter; /* The new sorter */ KeyInfo *pKeyInfo; /* Copy of pCsr->pKeyInfo with db==0 */ int szKeyInfo; /* Size of pCsr->pKeyInfo in bytes */ int sz; /* Size of pSorter in bytes */ int rc = SQLITE_OK; int nWorker = (sqlite3GlobalConfig.bCoreMutex?sqlite3GlobalConfig.nWorker:0); |
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660 661 662 663 664 665 666 | }else{ pKeyInfo = (KeyInfo*)((u8*)pSorter + sz); memcpy(pKeyInfo, pCsr->pKeyInfo, szKeyInfo); pKeyInfo->db = 0; if( nField && nWorker==0 ) pKeyInfo->nField = nField; pgsz = sqlite3BtreeGetPageSize(db->aDb[0].pBt); | | | | | | | | 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 | }else{ pKeyInfo = (KeyInfo*)((u8*)pSorter + sz); memcpy(pKeyInfo, pCsr->pKeyInfo, szKeyInfo); pKeyInfo->db = 0; if( nField && nWorker==0 ) pKeyInfo->nField = nField; pgsz = sqlite3BtreeGetPageSize(db->aDb[0].pBt); pSorter->nTask = nWorker + 1; for(i=0; i<pSorter->nTask; i++){ SortSubtask *pTask = &pSorter->aTask[i]; pTask->pKeyInfo = pKeyInfo; pTask->pVfs = db->pVfs; pTask->pgsz = pgsz; } if( !sqlite3TempInMemory(db) ){ pSorter->mnPmaSize = SORTER_MIN_WORKING * pgsz; mxCache = db->aDb[0].pSchema->cache_size; if( mxCache<SORTER_MIN_WORKING ) mxCache = SORTER_MIN_WORKING; pSorter->mxPmaSize = mxCache * pgsz; |
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702 703 704 705 706 707 708 | for(p=pRecord; p; p=pNext){ pNext = p->u.pNext; sqlite3DbFree(db, p); } } /* | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 | for(p=pRecord; p; p=pNext){ pNext = p->u.pNext; sqlite3DbFree(db, p); } } /* ** Free all resources owned by the object indicated by argument pTask. All ** fields of *pTask are zeroed before returning. */ static void vdbeSortSubtaskCleanup(sqlite3 *db, SortSubtask *pTask){ sqlite3DbFree(db, pTask->pUnpacked); pTask->pUnpacked = 0; if( pTask->aListMemory==0 ){ vdbeSorterRecordFree(0, pTask->pList); }else{ sqlite3_free(pTask->aListMemory); pTask->aListMemory = 0; } pTask->pList = 0; if( pTask->pTemp1 ){ sqlite3OsCloseFree(pTask->pTemp1); pTask->pTemp1 = 0; } } /* ** Join all threads. */ #if SQLITE_MAX_WORKER_THREADS>0 static int vdbeSorterJoinAll(VdbeSorter *pSorter, int rcin){ int rc = rcin; int i; for(i=0; i<pSorter->nTask; i++){ SortSubtask *pTask = &pSorter->aTask[i]; if( pTask->pTask ){ void *pRet; int rc2 = sqlite3ThreadJoin(pTask->pTask, &pRet); pTask->pTask = 0; pTask->bDone = 0; if( rc==SQLITE_OK ) rc = rc2; if( rc==SQLITE_OK ) rc = SQLITE_PTR_TO_INT(pRet); } } return rc; } #else # define vdbeSorterJoinAll(x,rcin) (rcin) #endif /* ** Allocate a new MergeEngine object with space for nIter iterators. */ static MergeEngine *vdbeMergeEngineNew(int nIter){ int N = 2; /* Smallest power of two >= nIter */ int nByte; /* Total bytes of space to allocate */ MergeEngine *pNew; /* Pointer to allocated object to return */ assert( nIter<=SORTER_MAX_MERGE_COUNT ); while( N<nIter ) N += N; nByte = sizeof(MergeEngine) + N * (sizeof(int) + sizeof(PmaReader)); pNew = (MergeEngine*)sqlite3MallocZero(nByte); if( pNew ){ pNew->nTree = N; pNew->aIter = (PmaReader*)&pNew[1]; pNew->aTree = (int*)&pNew->aIter[N]; } return pNew; } /* ** Free the MergeEngine object passed as the only argument. */ static void vdbeMergeEngineFree(MergeEngine *pMerger){ int i; if( pMerger ){ for(i=0; i<pMerger->nTree; i++){ vdbePmaReaderClear(&pMerger->aIter[i]); } } sqlite3_free(pMerger); } /* ** Reset a sorting cursor back to its original empty state. */ void sqlite3VdbeSorterReset(sqlite3 *db, VdbeSorter *pSorter){ int i; (void)vdbeSorterJoinAll(pSorter, SQLITE_OK); vdbeMergeEngineFree(pSorter->pMerger); pSorter->pMerger = 0; for(i=0; i<pSorter->nTask; i++){ SortSubtask *pTask = &pSorter->aTask[i]; vdbeSortSubtaskCleanup(db, pTask); } if( pSorter->aMemory==0 ){ vdbeSorterRecordFree(0, pSorter->pRecord); } pSorter->pRecord = 0; pSorter->nInMemory = 0; pSorter->bUsePMA = 0; pSorter->iMemory = 0; } /* ** Free any cursor components allocated by sqlite3VdbeSorterXXX routines. */ void sqlite3VdbeSorterClose(sqlite3 *db, VdbeCursor *pCsr){ VdbeSorter *pSorter = pCsr->pSorter; if( pSorter ){ sqlite3VdbeSorterReset(db, pSorter); vdbeMergeEngineFree(pSorter->pMerger); sqlite3_free(pSorter->aMemory); sqlite3DbFree(db, pSorter); pCsr->pSorter = 0; } } /* |
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838 839 840 841 842 843 844 | } /* ** Merge the two sorted lists p1 and p2 into a single list. ** Set *ppOut to the head of the new list. */ static void vdbeSorterMerge( | | | | | | | | | | | | | | | | | | | | 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 | } /* ** Merge the two sorted lists p1 and p2 into a single list. ** Set *ppOut to the head of the new list. */ static void vdbeSorterMerge( SortSubtask *pTask, /* Calling thread context */ SorterRecord *p1, /* First list to merge */ SorterRecord *p2, /* Second list to merge */ SorterRecord **ppOut /* OUT: Head of merged list */ ){ SorterRecord *pFinal = 0; SorterRecord **pp = &pFinal; void *pVal2 = p2 ? SRVAL(p2) : 0; while( p1 && p2 ){ int res; res = vdbeSorterCompare(pTask, SRVAL(p1), p1->nVal, pVal2, p2->nVal); if( res<=0 ){ *pp = p1; pp = &p1->u.pNext; p1 = p1->u.pNext; pVal2 = 0; }else{ *pp = p2; pp = &p2->u.pNext; p2 = p2->u.pNext; if( p2==0 ) break; pVal2 = SRVAL(p2); } } *pp = p1 ? p1 : p2; *ppOut = pFinal; } /* ** Sort the linked list of records headed at pTask->pList. Return ** SQLITE_OK if successful, or an SQLite error code (i.e. SQLITE_NOMEM) if ** an error occurs. */ static int vdbeSorterSort(SortSubtask *pTask){ int i; SorterRecord **aSlot; SorterRecord *p; aSlot = (SorterRecord **)sqlite3MallocZero(64 * sizeof(SorterRecord *)); if( !aSlot ){ return SQLITE_NOMEM; } p = pTask->pList; while( p ){ SorterRecord *pNext; if( pTask->aListMemory ){ if( (u8*)p==pTask->aListMemory ){ pNext = 0; }else{ assert( p->u.iNext<sqlite3MallocSize(pTask->aListMemory) ); pNext = (SorterRecord*)&pTask->aListMemory[p->u.iNext]; } }else{ pNext = p->u.pNext; } p->u.pNext = 0; for(i=0; aSlot[i]; i++){ vdbeSorterMerge(pTask, p, aSlot[i], &p); aSlot[i] = 0; } aSlot[i] = p; p = pNext; } p = 0; for(i=0; i<64; i++){ vdbeSorterMerge(pTask, p, aSlot[i], &p); } pTask->pList = p; sqlite3_free(aSlot); return SQLITE_OK; } /* ** Initialize a PMA-writer object. */ static void vdbePmaWriterInit( sqlite3_file *pFile, /* File to write to */ PmaWriter *p, /* Object to populate */ int nBuf, /* Buffer size */ i64 iStart /* Offset of pFile to begin writing at */ ){ memset(p, 0, sizeof(PmaWriter)); p->aBuffer = (u8*)sqlite3Malloc(nBuf); if( !p->aBuffer ){ p->eFWErr = SQLITE_NOMEM; }else{ p->iBufEnd = p->iBufStart = (iStart % nBuf); p->iWriteOff = iStart - p->iBufStart; p->nBuffer = nBuf; p->pFile = pFile; } } /* ** Write nData bytes of data to the PMA. Return SQLITE_OK ** if successful, or an SQLite error code if an error occurs. */ static void vdbePmaWriteBlob(PmaWriter *p, u8 *pData, int nData){ int nRem = nData; while( nRem>0 && p->eFWErr==0 ){ int nCopy = nRem; if( nCopy>(p->nBuffer - p->iBufEnd) ){ nCopy = p->nBuffer - p->iBufEnd; } |
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965 966 967 968 969 970 971 | assert( p->iBufEnd<p->nBuffer ); nRem -= nCopy; } } /* | | | | | | | | | 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 | assert( p->iBufEnd<p->nBuffer ); nRem -= nCopy; } } /* ** Flush any buffered data to disk and clean up the PMA-writer object. ** The results of using the PMA-writer after this call are undefined. ** Return SQLITE_OK if flushing the buffered data succeeds or is not ** required. Otherwise, return an SQLite error code. ** ** Before returning, set *piEof to the offset immediately following the ** last byte written to the file. */ static int vdbePmaWriterFinish(PmaWriter *p, i64 *piEof){ int rc; if( p->eFWErr==0 && ALWAYS(p->aBuffer) && p->iBufEnd>p->iBufStart ){ p->eFWErr = sqlite3OsWrite(p->pFile, &p->aBuffer[p->iBufStart], p->iBufEnd - p->iBufStart, p->iWriteOff + p->iBufStart ); } *piEof = (p->iWriteOff + p->iBufEnd); sqlite3_free(p->aBuffer); rc = p->eFWErr; memset(p, 0, sizeof(PmaWriter)); return rc; } /* ** Write value iVal encoded as a varint to the PMA. Return ** SQLITE_OK if successful, or an SQLite error code if an error occurs. */ static void vdbePmaWriteVarint(PmaWriter *p, u64 iVal){ int nByte; u8 aByte[10]; nByte = sqlite3PutVarint(aByte, iVal); vdbePmaWriteBlob(p, aByte, nByte); } #if SQLITE_MAX_MMAP_SIZE>0 /* ** The first argument is a file-handle open on a temporary file. The file ** is guaranteed to be nByte bytes or smaller in size. This function ** attempts to extend the file to nByte bytes in size and to ensure that |
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1036 1037 1038 1039 1040 1041 1042 | ** * A varint. This varint contains the total number of bytes of content ** in the PMA (not including the varint itself). ** ** * One or more records packed end-to-end in order of ascending keys. ** Each record consists of a varint followed by a blob of data (the ** key). The varint is the number of bytes in the blob of data. */ | | | | | | | | | | | | > | | | | | | | | | | | | | | | | | | | 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 | ** * A varint. This varint contains the total number of bytes of content ** in the PMA (not including the varint itself). ** ** * One or more records packed end-to-end in order of ascending keys. ** Each record consists of a varint followed by a blob of data (the ** key). The varint is the number of bytes in the blob of data. */ static int vdbeSorterListToPMA(SortSubtask *pTask){ int rc = SQLITE_OK; /* Return code */ PmaWriter writer; /* Object used to write to the file */ memset(&writer, 0, sizeof(PmaWriter)); assert( pTask->nInMemory>0 ); /* If the first temporary PMA file has not been opened, open it now. */ if( pTask->pTemp1==0 ){ rc = vdbeSorterOpenTempFile(pTask->pVfs, &pTask->pTemp1); assert( rc!=SQLITE_OK || pTask->pTemp1 ); assert( pTask->iTemp1Off==0 ); assert( pTask->nPMA==0 ); } /* Try to get the file to memory map */ if( rc==SQLITE_OK ){ rc = vdbeSorterExtendFile( pTask->pTemp1, pTask->iTemp1Off + pTask->nInMemory + 9 ); } if( rc==SQLITE_OK ){ SorterRecord *p; SorterRecord *pNext = 0; vdbePmaWriterInit(pTask->pTemp1, &writer, pTask->pgsz, pTask->iTemp1Off); pTask->nPMA++; vdbePmaWriteVarint(&writer, pTask->nInMemory); for(p=pTask->pList; p; p=pNext){ pNext = p->u.pNext; vdbePmaWriteVarint(&writer, p->nVal); vdbePmaWriteBlob(&writer, SRVAL(p), p->nVal); if( pTask->aListMemory==0 ) sqlite3_free(p); } pTask->pList = p; rc = vdbePmaWriterFinish(&writer, &pTask->iTemp1Off); } assert( pTask->pList==0 || rc!=SQLITE_OK ); return rc; } /* ** Advance the MergeEngine iterator passed as the second argument to ** the next entry. Set *pbEof to true if this means the iterator has ** reached EOF. ** ** Return SQLITE_OK if successful or an error code if an error occurs. */ static int vdbeSorterNext( SortSubtask *pTask, MergeEngine *pMerger, int *pbEof ){ int rc; int iPrev = pMerger->aTree[1];/* Index of iterator to advance */ /* Advance the current iterator */ rc = vdbePmaReaderNext(&pMerger->aIter[iPrev]); /* Update contents of aTree[] */ if( rc==SQLITE_OK ){ int i; /* Index of aTree[] to recalculate */ PmaReader *pIter1; /* First iterator to compare */ PmaReader *pIter2; /* Second iterator to compare */ u8 *pKey2; /* To pIter2->aKey, or 0 if record cached */ /* Find the first two iterators to compare. The one that was just ** advanced (iPrev) and the one next to it in the array. */ pIter1 = &pMerger->aIter[(iPrev & 0xFFFE)]; pIter2 = &pMerger->aIter[(iPrev | 0x0001)]; pKey2 = pIter2->aKey; for(i=(pMerger->nTree+iPrev)/2; i>0; i=i/2){ /* Compare pIter1 and pIter2. Store the result in variable iRes. */ int iRes; if( pIter1->pFile==0 ){ iRes = +1; }else if( pIter2->pFile==0 ){ iRes = -1; }else{ iRes = vdbeSorterCompare(pTask, pIter1->aKey, pIter1->nKey, pKey2, pIter2->nKey ); } /* If pIter1 contained the smaller value, set aTree[i] to its index. ** Then set pIter2 to the next iterator to compare to pIter1. In this ** case there is no cache of pIter2 in pTask->pUnpacked, so set ** pKey2 to point to the record belonging to pIter2. ** ** Alternatively, if pIter2 contains the smaller of the two values, ** set aTree[i] to its index and update pIter1. If vdbeSorterCompare() ** was actually called above, then pTask->pUnpacked now contains ** a value equivalent to pIter2. So set pKey2 to NULL to prevent ** vdbeSorterCompare() from decoding pIter2 again. ** ** If the two values were equal, then the value from the oldest ** PMA should be considered smaller. The VdbeSorter.aIter[] array ** is sorted from oldest to newest, so pIter1 contains older values ** than pIter2 iff (pIter1<pIter2). */ |
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1159 1160 1161 1162 1163 1164 1165 | } /* ** The main routine for sorter-thread operations. */ static void *vdbeSortSubtaskMain(void *pCtx){ int rc = SQLITE_OK; | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 | } /* ** The main routine for sorter-thread operations. */ static void *vdbeSortSubtaskMain(void *pCtx){ int rc = SQLITE_OK; SortSubtask *pTask = (SortSubtask*)pCtx; assert( pTask->eWork==SORT_SUBTASK_SORT || pTask->eWork==SORT_SUBTASK_TO_PMA || pTask->eWork==SORT_SUBTASK_CONS ); assert( pTask->bDone==0 ); if( pTask->pUnpacked==0 ){ char *pFree; pTask->pUnpacked = sqlite3VdbeAllocUnpackedRecord( pTask->pKeyInfo, 0, 0, &pFree ); assert( pTask->pUnpacked==(UnpackedRecord*)pFree ); if( pFree==0 ){ rc = SQLITE_NOMEM; goto thread_out; } pTask->pUnpacked->nField = pTask->pKeyInfo->nField; pTask->pUnpacked->errCode = 0; } if( pTask->eWork==SORT_SUBTASK_CONS ){ assert( pTask->pList==0 ); while( pTask->nPMA>pTask->nConsolidate && rc==SQLITE_OK ){ int nIter = MIN(pTask->nPMA, SORTER_MAX_MERGE_COUNT); sqlite3_file *pTemp2 = 0; /* Second temp file to use */ MergeEngine *pMerger; /* Object for reading/merging PMA data */ i64 iReadOff = 0; /* Offset in pTemp1 to read from */ i64 iWriteOff = 0; /* Offset in pTemp2 to write to */ int i; /* Allocate a merger object to merge PMAs together. */ pMerger = vdbeMergeEngineNew(nIter); if( pMerger==0 ){ rc = SQLITE_NOMEM; break; } /* Open a second temp file to write merged data to */ rc = vdbeSorterOpenTempFile(pTask->pVfs, &pTemp2); if( rc==SQLITE_OK ){ rc = vdbeSorterExtendFile(pTemp2, pTask->iTemp1Off); } if( rc!=SQLITE_OK ){ vdbeMergeEngineFree(pMerger); break; } /* This loop runs once for each output PMA. Each output PMA is made ** of data merged from up to SORTER_MAX_MERGE_COUNT input PMAs. */ for(i=0; i<pTask->nPMA; i+=SORTER_MAX_MERGE_COUNT){ PmaWriter writer; /* Object for writing data to pTemp2 */ i64 nOut = 0; /* Bytes of data in output PMA */ int bEof = 0; int rc2; /* Configure the merger object to read and merge data from the next ** SORTER_MAX_MERGE_COUNT PMAs in pTemp1 (or from all remaining PMAs, ** if that is fewer). */ int iIter; for(iIter=0; iIter<SORTER_MAX_MERGE_COUNT; iIter++){ PmaReader *pIter = &pMerger->aIter[iIter]; rc = vdbePmaReaderInit(pTask, iReadOff, pIter, &nOut); iReadOff = pIter->iEof; if( iReadOff>=pTask->iTemp1Off || rc!=SQLITE_OK ) break; } for(iIter=pMerger->nTree-1; rc==SQLITE_OK && iIter>0; iIter--){ rc = vdbeSorterDoCompare(pTask, pMerger, iIter); } vdbePmaWriterInit(pTemp2, &writer, pTask->pgsz, iWriteOff); vdbePmaWriteVarint(&writer, nOut); while( rc==SQLITE_OK && bEof==0 ){ PmaReader *pIter = &pMerger->aIter[ pMerger->aTree[1] ]; assert( pIter->pFile!=0 ); /* pIter is not at EOF */ vdbePmaWriteVarint(&writer, pIter->nKey); vdbePmaWriteBlob(&writer, pIter->aKey, pIter->nKey); rc = vdbeSorterNext(pTask, pMerger, &bEof); } rc2 = vdbePmaWriterFinish(&writer, &iWriteOff); if( rc==SQLITE_OK ) rc = rc2; } vdbeMergeEngineFree(pMerger); sqlite3OsCloseFree(pTask->pTemp1); pTask->pTemp1 = pTemp2; pTask->nPMA = (i / SORTER_MAX_MERGE_COUNT); pTask->iTemp1Off = iWriteOff; } }else{ /* Sort the pTask->pList list */ rc = vdbeSorterSort(pTask); /* If required, write the list out to a PMA. */ if( rc==SQLITE_OK && pTask->eWork==SORT_SUBTASK_TO_PMA ){ #ifdef SQLITE_DEBUG i64 nExpect = pTask->nInMemory + sqlite3VarintLen(pTask->nInMemory) + pTask->iTemp1Off; #endif rc = vdbeSorterListToPMA(pTask); assert( rc!=SQLITE_OK || (nExpect==pTask->iTemp1Off) ); } } thread_out: pTask->bDone = 1; if( rc==SQLITE_OK && pTask->pUnpacked->errCode ){ assert( pTask->pUnpacked->errCode==SQLITE_NOMEM ); rc = SQLITE_NOMEM; } return SQLITE_INT_TO_PTR(rc); } /* ** Run the activity scheduled by the object passed as the only argument ** in the current thread. */ static int vdbeSorterRunTask(SortSubtask *pTask){ int rc = SQLITE_PTR_TO_INT( vdbeSortSubtaskMain((void*)pTask) ); assert( pTask->bDone ); pTask->bDone = 0; return rc; } /* ** Flush the current contents of VdbeSorter.pRecord to a new PMA, possibly ** using a background thread. ** ** If argument bFg is non-zero, the operation always uses the calling thread. */ static int vdbeSorterFlushPMA(sqlite3 *db, const VdbeCursor *pCsr, int bFg){ VdbeSorter *pSorter = pCsr->pSorter; int rc = SQLITE_OK; int i; SortSubtask *pTask = 0; /* Thread context used to create new PMA */ int nWorker = (pSorter->nTask-1); pSorter->bUsePMA = 1; for(i=0; i<nWorker; i++){ int iTest = (pSorter->iPrev + i + 1) % nWorker; pTask = &pSorter->aTask[iTest]; #if SQLITE_MAX_WORKER_THREADS>0 if( pTask->bDone ){ void *pRet; assert( pTask->pTask ); rc = sqlite3ThreadJoin(pTask->pTask, &pRet); pTask->pTask = 0; pTask->bDone = 0; if( rc==SQLITE_OK ){ rc = SQLITE_PTR_TO_INT(pRet); } } #endif if( pTask->pThread==0 ) break; pTask = 0; } if( pTask==0 ){ pTask = &pSorter->aTask[nWorker]; } pSorter->iPrev = (pTask - pSorter->aTask); if( rc==SQLITE_OK ){ assert( pTask->pThread==0 && pTask->bDone==0 ); pTask->eWork = SORT_SUBTASK_TO_PMA; pTask->pList = pSorter->pRecord; pTask->nInMemory = pSorter->nInMemory; pSorter->nInMemory = 0; pSorter->pRecord = 0; if( pSorter->aMemory ){ u8 *aMem = pTask->aListMemory; pTask->aListMemory = pSorter->aMemory; pSorter->aMemory = aMem; } #if SQLITE_MAX_WORKER_THREADS>0 if( !bFg && pTask!=&pSorter->aTask[nWorker] ){ /* Launch a background thread for this operation */ void *pCtx = (void*)pTask; assert( pSorter->aMemory==0 || pTask->aListMemory!=0 ); if( pTask->aListMemory ){ if( pSorter->aMemory==0 ){ pSorter->aMemory = sqlite3Malloc(pSorter->nMemory); if( pSorter->aMemory==0 ) return SQLITE_NOMEM; }else{ pSorter->nMemory = sqlite3MallocSize(pSorter->aMemory); } } rc = sqlite3ThreadCreate(&pTask->pTask, vdbeSortSubtaskMain, pCtx); }else #endif { /* Use the foreground thread for this operation */ rc = vdbeSorterRunTask(pTask); if( rc==SQLITE_OK ){ u8 *aMem = pTask->aListMemory; pTask->aListMemory = pSorter->aMemory; pSorter->aMemory = aMem; assert( pTask->pList==0 ); } } } return rc; } |
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1465 1466 1467 1468 1469 1470 1471 | /* ** Return the total number of PMAs in all temporary files. */ static int vdbeSorterCountPMA(VdbeSorter *pSorter){ int nPMA = 0; int i; | | | | > | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 | /* ** Return the total number of PMAs in all temporary files. */ static int vdbeSorterCountPMA(VdbeSorter *pSorter){ int nPMA = 0; int i; for(i=0; i<pSorter->nTask; i++){ nPMA += pSorter->aTask[i].nPMA; } return nPMA; } /* ** Once the sorter has been populated by calls to sqlite3VdbeSorterWrite, ** this function is called to prepare for iterating through the records ** in sorted order. */ int sqlite3VdbeSorterRewind(sqlite3 *db, const VdbeCursor *pCsr, int *pbEof){ VdbeSorter *pSorter = pCsr->pSorter; int rc = SQLITE_OK; /* Return code */ assert( pSorter ); /* If no data has been written to disk, then do not do so now. Instead, ** sort the VdbeSorter.pRecord list. The vdbe layer will read data directly ** from the in-memory list. */ if( pSorter->bUsePMA==0 ){ if( pSorter->pRecord ){ SortSubtask *pTask = &pSorter->aTask[0]; *pbEof = 0; pTask->pList = pSorter->pRecord; pTask->eWork = SORT_SUBTASK_SORT; assert( pTask->aListMemory==0 ); pTask->aListMemory = pSorter->aMemory; rc = vdbeSorterRunTask(pTask); pTask->aListMemory = 0; pSorter->pRecord = pTask->pList; pTask->pList = 0; }else{ *pbEof = 1; } return rc; } /* Write the current in-memory list to a PMA. */ if( pSorter->pRecord ){ rc = vdbeSorterFlushPMA(db, pCsr, 1); } /* Join all threads */ rc = vdbeSorterJoinAll(pSorter, rc); /* If there are more than SORTER_MAX_MERGE_COUNT PMAs on disk, merge ** some of them together so that this is no longer the case. */ if( vdbeSorterCountPMA(pSorter)>SORTER_MAX_MERGE_COUNT ){ int i; for(i=0; rc==SQLITE_OK && i<pSorter->nTask; i++){ SortSubtask *pTask = &pSorter->aTask[i]; if( pTask->pTemp1 ){ pTask->nConsolidate = SORTER_MAX_MERGE_COUNT / pSorter->nTask; pTask->eWork = SORT_SUBTASK_CONS; #if SQLITE_MAX_WORKER_THREADS>0 if( i<(pSorter->nTask-1) ){ void *pCtx = (void*)pTask; rc = sqlite3ThreadCreate(&pTask->pTask,vdbeSortSubtaskMain,pCtx); }else #endif { rc = vdbeSorterRunTask(pTask); } } } } /* Join all threads */ rc = vdbeSorterJoinAll(pSorter, rc); /* Assuming no errors have occurred, set up a merger structure to read ** and merge all remaining PMAs. */ assert( pSorter->pMerger==0 ); if( rc==SQLITE_OK ){ int nIter = 0; /* Number of iterators used */ int i; MergeEngine *pMerger; for(i=0; i<pSorter->nTask; i++){ nIter += pSorter->aTask[i].nPMA; } pSorter->pMerger = pMerger = vdbeMergeEngineNew(nIter); if( pMerger==0 ){ rc = SQLITE_NOMEM; }else{ int iIter = 0; int iThread = 0; for(iThread=0; iThread<pSorter->nTask; iThread++){ int iPMA; i64 iReadOff = 0; SortSubtask *pTask = &pSorter->aTask[iThread]; for(iPMA=0; iPMA<pTask->nPMA && rc==SQLITE_OK; iPMA++){ i64 nDummy = 0; PmaReader *pIter = &pMerger->aIter[iIter++]; rc = vdbePmaReaderInit(pTask, iReadOff, pIter, &nDummy); iReadOff = pIter->iEof; } } for(i=pMerger->nTree-1; rc==SQLITE_OK && i>0; i--){ rc = vdbeSorterDoCompare(&pSorter->aTask[0], pMerger, i); } } } if( rc==SQLITE_OK ){ *pbEof = (pSorter->pMerger->aIter[pSorter->pMerger->aTree[1]].pFile==0); } return rc; } /* ** Advance to the next element in the sorter. */ int sqlite3VdbeSorterNext(sqlite3 *db, const VdbeCursor *pCsr, int *pbEof){ VdbeSorter *pSorter = pCsr->pSorter; int rc; /* Return code */ if( pSorter->pMerger ){ rc = vdbeSorterNext(&pSorter->aTask[0], pSorter->pMerger, pbEof); }else{ SorterRecord *pFree = pSorter->pRecord; pSorter->pRecord = pFree->u.pNext; pFree->u.pNext = 0; if( pSorter->aMemory==0 ) vdbeSorterRecordFree(db, pFree); *pbEof = !pSorter->pRecord; rc = SQLITE_OK; |
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1607 1608 1609 1610 1611 1612 1613 | */ static void *vdbeSorterRowkey( const VdbeSorter *pSorter, /* Sorter object */ int *pnKey /* OUT: Size of current key in bytes */ ){ void *pKey; if( pSorter->pMerger ){ | | | 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 | */ static void *vdbeSorterRowkey( const VdbeSorter *pSorter, /* Sorter object */ int *pnKey /* OUT: Size of current key in bytes */ ){ void *pKey; if( pSorter->pMerger ){ PmaReader *pIter; pIter = &pSorter->pMerger->aIter[ pSorter->pMerger->aTree[1] ]; *pnKey = pIter->nKey; pKey = pIter->aKey; }else{ *pnKey = pSorter->pRecord->nVal; pKey = SRVAL(pSorter->pRecord); } |
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1659 1660 1661 1662 1663 1664 1665 | int sqlite3VdbeSorterCompare( const VdbeCursor *pCsr, /* Sorter cursor */ Mem *pVal, /* Value to compare to current sorter key */ int nIgnore, /* Ignore this many fields at the end */ int *pRes /* OUT: Result of comparison */ ){ VdbeSorter *pSorter = pCsr->pSorter; | | | 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 | int sqlite3VdbeSorterCompare( const VdbeCursor *pCsr, /* Sorter cursor */ Mem *pVal, /* Value to compare to current sorter key */ int nIgnore, /* Ignore this many fields at the end */ int *pRes /* OUT: Result of comparison */ ){ VdbeSorter *pSorter = pCsr->pSorter; UnpackedRecord *r2 = pSorter->aTask[0].pUnpacked; KeyInfo *pKeyInfo = pCsr->pKeyInfo; int i; void *pKey; int nKey; /* Sorter key to compare pVal with */ assert( r2->nField>=pKeyInfo->nField-nIgnore ); r2->nField = pKeyInfo->nField-nIgnore; |
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