Many hyperlinks are disabled.
Use anonymous login
to enable hyperlinks.
Overview
Comment: | Begin adding code to make the log file circular. |
---|---|
Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA1: |
ec6dda0ade61f1511404fb0f4145d8cc |
User & Date: | dan 2013-10-26 19:58:34.163 |
Context
2013-10-28
| ||
10:47 | Fix some problems with circular logs. check-in: 4b36a0245f user: dan tags: trunk | |
2013-10-26
| ||
19:58 | Begin adding code to make the log file circular. check-in: ec6dda0ade user: dan tags: trunk | |
12:44 | Use sqlite4_malloc instead of malloc in test fixture for num check-in: 3f6924e784 user: peterreid tags: trunk | |
Changes
Changes to src/bt_log.c.
︙ | ︙ | |||
17 18 19 20 21 22 23 24 25 26 27 28 29 30 | #include <assert.h> #include <stdio.h> #include <stddef.h> /* Magic values identifying WAL file header */ #define BT_WAL_MAGIC 0xBEE1CA62 #define BT_WAL_VERSION 0x00000001 typedef struct BtWalHdr BtWalHdr; typedef struct BtShmHdr BtShmHdr; typedef struct BtCkptHdr BtCkptHdr; typedef struct BtFrameHdr BtFrameHdr; typedef struct BtShm BtShm; | > > > > | 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 | #include <assert.h> #include <stdio.h> #include <stddef.h> /* Magic values identifying WAL file header */ #define BT_WAL_MAGIC 0xBEE1CA62 #define BT_WAL_VERSION 0x00000001 /* Wrap the log around if there is a block of this many free frames at ** the start of the file. */ #define BT_NWRAPLOG 100 typedef struct BtWalHdr BtWalHdr; typedef struct BtShmHdr BtShmHdr; typedef struct BtCkptHdr BtCkptHdr; typedef struct BtFrameHdr BtFrameHdr; typedef struct BtShm BtShm; |
︙ | ︙ | |||
47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 | u32 iFirstFrame; /* First frame of log (numbered from 1) */ u32 aCksum[2]; /* Checksum of all prior fields */ }; /* ** WAL Frame header. All fields are stored in big-endian order. */ struct BtFrameHdr { u32 pgno; /* Page number of this frame */ u32 ctrl; /* Next frame pointer and commit bit */ u32 aCksum[2]; /* Frame checksum */ }; #define BT_FRAME_COMMIT 0x80000000 /* ** Shared memory header. Shared memory begins with two copies of ** this structure. All fields are stored in machine byte-order. */ struct BtShmHdr { u32 aLog[6]; /* First/last frames for each log region */ int nSector; /* Sector size assumed for WAL file */ u32 aFrameCksum[2]; /* Checksum of previous frame */ | > > > > > > > | | 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 82 83 84 85 86 87 88 89 | u32 iFirstFrame; /* First frame of log (numbered from 1) */ u32 aCksum[2]; /* Checksum of all prior fields */ }; /* ** WAL Frame header. All fields are stored in big-endian order. ** ** ctrl: ** The most-significant-bit (BT_FRAME_COMMIT) of this field is set for ** a commit frame and clear for all others. The other 31 bits contain ** the frame number of the next frame in the log. */ struct BtFrameHdr { u32 pgno; /* Page number of this frame */ u32 ctrl; /* Next frame pointer and commit bit */ u32 aCksum[2]; /* Frame checksum */ }; #define BT_FRAME_COMMIT 0x80000000 /* ** Shared memory header. Shared memory begins with two copies of ** this structure. All fields are stored in machine byte-order. */ struct BtShmHdr { u32 aLog[6]; /* First/last frames for each log region */ int nSector; /* Sector size assumed for WAL file */ int iHashSide; /* Hash table side for region (c) of log */ u32 aFrameCksum[2]; /* Checksum of previous frame */ u32 iNextFrame; /* Location to write next log frame to */ int padding; /* So that this structure is 8-byte aligned */ u32 aCksum[2]; /* Object checksum */ }; /* ** A single instance of this structure follows the two BtShmHdr structures ** in shared memory. ** |
︙ | ︙ | |||
105 106 107 108 109 110 111 | ** Log handle used by bt_pager.c to access functionality implemented by ** this module. */ struct BtLog { BtLock *pLock; /* Lock object associated with this log */ bt_file *pFd; /* File handle open on WAL file */ BtShmHdr snapshot; /* Current snapshot of shm-header */ | < > | 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 | ** Log handle used by bt_pager.c to access functionality implemented by ** this module. */ struct BtLog { BtLock *pLock; /* Lock object associated with this log */ bt_file *pFd; /* File handle open on WAL file */ BtShmHdr snapshot; /* Current snapshot of shm-header */ int nShm; /* Size of apShm[] array */ u8 **apShm; /* Array of mapped shared-memory blocks */ int nWrapLog; /* Wrap if this many free frames at start */ }; typedef u16 ht_slot; /* ** Number of entries in each hash table bar the first. */ |
︙ | ︙ | |||
151 152 153 154 155 156 157 158 159 160 161 162 163 164 | ** returns the value that would be produced by intepreting the 4 bytes ** of the input value as a little-endian integer. */ #define BYTESWAP32(x) ( \ (((x)&0x000000FF)<<24) + (((x)&0x0000FF00)<<8) \ + (((x)&0x00FF0000)>>8) + (((x)&0xFF000000)>>24) \ ) /* ** Generate or extend an 8 byte checksum based on the data in ** array aByte[] and the initial values of aIn[0] and aIn[1] (or ** initial values of 0 and 0 if aIn==NULL). ** ** The checksum is written back into aOut[] before returning. | > > > > > > > > | 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 | ** returns the value that would be produced by intepreting the 4 bytes ** of the input value as a little-endian integer. */ #define BYTESWAP32(x) ( \ (((x)&0x000000FF)<<24) + (((x)&0x0000FF00)<<8) \ + (((x)&0x00FF0000)>>8) + (((x)&0xFF000000)>>24) \ ) static void btLogDebugTopology(char *zStr, u32 *aLog){ fprintf(stderr, "%s: %d..%d %d..%d %d..%d\n", zStr, (int)aLog[0], (int)aLog[1], (int)aLog[2], (int)aLog[3], (int)aLog[4], (int)aLog[5] ); fflush(stderr); } /* ** Generate or extend an 8 byte checksum based on the data in ** array aByte[] and the initial values of aIn[0] and aIn[1] (or ** initial values of 0 and 0 if aIn==NULL). ** ** The checksum is written back into aOut[] before returning. |
︙ | ︙ | |||
332 333 334 335 336 337 338 | btLogChecksum(1, aBuf, pgsz, aCksum, aCksum); if( aCksum[0]!=fhdr.aCksum[0] || aCksum[1]!=fhdr.aCksum[1] ) break; } if( rc==SQLITE4_OK ){ rc = xFrame(pLog, pCtx, iFrame, &fhdr); } | | > | > > | | 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 | btLogChecksum(1, aBuf, pgsz, aCksum, aCksum); if( aCksum[0]!=fhdr.aCksum[0] || aCksum[1]!=fhdr.aCksum[1] ) break; } if( rc==SQLITE4_OK ){ rc = xFrame(pLog, pCtx, iFrame, &fhdr); } iFrame = (fhdr.ctrl & ~BT_FRAME_COMMIT); } return rc; } /* ** Locate the iHash'th hash table in shared memory. Return it. */ static int btLogFindHash( BtLog *pLog, /* Log handle */ int iSide, /* Which set of hash slots to return */ int iHash, /* Hash table (numbered from 0) to find */ ht_slot **paHash, /* OUT: Pointer to hash slots */ u32 **paPgno, /* OUT: Pointer to page number array */ u32 *piZero /* OUT: Frame associated with *paPgno[0] */ ){ int rc; /* Return code */ assert( iSide==0 || iSide==1 ); rc = btLogMapShm(pLog, iHash); if( rc==SQLITE4_OK ){ u8 *aChunk = pLog->apShm[iHash]; u32 *aPgno; u32 iZero; *paHash = (ht_slot*)&aChunk[iSide?HASHTABLE_OFFSET_1:HASHTABLE_OFFSET_2]; if( iHash==0 ){ aPgno = (u32*)&aChunk[sizeof(BtShm)]; iZero = 1; }else{ aPgno = (u32*)aChunk; iZero = 1 + HASHTABLE_NFRAME_ONE + (HASHTABLE_NFRAME * (iHash-1)); } |
︙ | ︙ | |||
404 405 406 407 408 409 410 411 412 413 414 415 | */ static int btLogHashInsert(BtLog *pLog, u32 pgno, u32 iFrame){ int iHash; /* Index of hash table to update */ int rc = SQLITE4_OK; /* Return code */ ht_slot *aHash; /* Hash slots */ u32 *aPgno; /* Page array for updated hash table */ u32 iZero; /* Zero-offset of updated hash table */ assert( iFrame>=1 && pgno>=1 ); /* Find the required hash table */ iHash = btLogFrameHash(pLog, iFrame); | > | > > > > | 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 | */ static int btLogHashInsert(BtLog *pLog, u32 pgno, u32 iFrame){ int iHash; /* Index of hash table to update */ int rc = SQLITE4_OK; /* Return code */ ht_slot *aHash; /* Hash slots */ u32 *aPgno; /* Page array for updated hash table */ u32 iZero; /* Zero-offset of updated hash table */ int iSide = pLog->snapshot.iHashSide; assert( iFrame>=1 && pgno>=1 ); /* Find the required hash table */ iHash = btLogFrameHash(pLog, iFrame); rc = btLogFindHash(pLog, iSide, iHash, &aHash, &aPgno, &iZero); /* Update the hash table */ if( rc==SQLITE4_OK ){ int iSlot; int nCollide = HASHTABLE_NSLOT*2; aPgno[iFrame-iZero] = pgno; if( iFrame==iZero ){ memset(aHash, 0, sizeof(ht_slot) * HASHTABLE_NSLOT); } for(iSlot=btLogHashKey(pLog,pgno); ; iSlot=btLogHashNext(pLog, iSlot)){ if( aHash[iSlot]==0 ){ aHash[iSlot] = (iFrame-iZero+1); break; } if( (nCollide--)==0 ) return btErrorBkpt(SQLITE4_CORRUPT); |
︙ | ︙ | |||
437 438 439 440 441 442 443 444 445 | ** Remove everything following frame iFrame from the iHash'th hash table. */ static int btLogHashRollback(BtLog *pLog, int iHash, u32 iFrame){ const int nPgno = (iHash==0 ? HASHTABLE_NFRAME_ONE : HASHTABLE_NFRAME); ht_slot *aHash; /* Hash slots */ u32 *aPgno; /* Page array for updated hash table */ u32 iZero; /* Zero-offset of updated hash table */ int rc; | > | | > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > | > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > | 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 | ** Remove everything following frame iFrame from the iHash'th hash table. */ static int btLogHashRollback(BtLog *pLog, int iHash, u32 iFrame){ const int nPgno = (iHash==0 ? HASHTABLE_NFRAME_ONE : HASHTABLE_NFRAME); ht_slot *aHash; /* Hash slots */ u32 *aPgno; /* Page array for updated hash table */ u32 iZero; /* Zero-offset of updated hash table */ int iSide = pLog->snapshot.iHashSide; int rc; rc = btLogFindHash(pLog, iSide, iHash, &aHash, &aPgno, &iZero); if( rc==SQLITE4_OK ){ int i; ht_slot iMax; iMax = (iFrame - iZero) + 1; for(i=0; i<HASHTABLE_NSLOT; i++){ if( aHash[i]>iMax ) aHash[i] = 0; } memset(&aPgno[iMax], 0, (nPgno-iMax)*sizeof(u32)); } return rc; } /* ** Return true if log is completely empty (as it is if a file zero bytes ** in size has been opened or created). */ static int btLogIsEmpty(BtLog *pLog){ return (pLog->snapshot.aLog[4]==0 && pLog->snapshot.iNextFrame==0); } typedef struct FrameRecoverCtx FrameRecoverCtx; struct FrameRecoverCtx { u32 iLast; /* Frame containing last commit flag in log */ u32 iNextFrame; /* Frame that follows frame iLast */ }; static int btLogRecoverFrame( BtLog *pLog, /* Log module handle */ void *pCtx, /* woints to type u32 - pgno of last commit*/ u32 iFrame, /* Frame number */ BtFrameHdr *pHdr /* Frame header */ ){ if( btLogIsEmpty(pLog) ){ /* This is the first frame recovered. It is therefore both the first ** and last frame of log region (c). */ pLog->snapshot.aLog[4] = iFrame; pLog->snapshot.aLog[5] = iFrame; }else{ u32 iExpect = pLog->snapshot.aLog[5]+1; if( iFrame==iExpect ){ pLog->snapshot.aLog[5] = iFrame; }else if( iFrame<iExpect ){ assert( iFrame==1 ); assert( pLog->snapshot.aLog[0]==0 && pLog->snapshot.aLog[1]==0 ); pLog->snapshot.aLog[0] = pLog->snapshot.aLog[4]; pLog->snapshot.aLog[1] = pLog->snapshot.aLog[5]; pLog->snapshot.aLog[4] = iFrame; pLog->snapshot.aLog[5] = iFrame; pLog->snapshot.iHashSide = (pLog->snapshot.iHashSide + 1) % 2; }else{ assert( pLog->snapshot.aLog[2]==0 && pLog->snapshot.aLog[3]==0 ); pLog->snapshot.aLog[2] = pLog->snapshot.aLog[4]; pLog->snapshot.aLog[3] = pLog->snapshot.aLog[5]; pLog->snapshot.aLog[4] = iFrame; pLog->snapshot.aLog[5] = iFrame; } } btLogHashInsert(pLog, pHdr->pgno, iFrame); if( pHdr->ctrl & BT_FRAME_COMMIT ){ FrameRecoverCtx *pFRC = (FrameRecoverCtx*)pCtx; pFRC->iLast = iFrame; pFRC->iNextFrame = (pHdr->ctrl & ~BT_FRAME_COMMIT); memcpy(pLog->snapshot.aFrameCksum, pHdr->aCksum, sizeof(pHdr->aCksum)); } #if 0 fprintf(stderr, "recovered frame=%d pgno=%d\n", iFrame, pHdr->pgno); fflush(stderr); #endif return 0; } /* ** This function is called as part of log recovery. The log file has ** already been scanned and the log topology (pLog->snapshot.aLog[]) ** shared-memory hash tables have been populated with data corresponding ** to the entire set of valid frames recovered from the log file - ** including uncommitted frames. This function removes the uncommitted ** frames from the log topology and shared hash tables. */ static int btLogRollbackRecovery(BtLog *pLog, FrameRecoverCtx *pCtx){ u32 iLast = pCtx->iLast; /* Last committed frame in log file */ u32 *aLog = pLog->snapshot.aLog;/* Log file topology */ while( iLast<aLog[4] || iLast>aLog[5] ){ if( aLog[2] ){ aLog[5] = aLog[3]; aLog[4] = aLog[2]; if( aLog[0] && aLog[0]<aLog[4] ){ aLog[3] = aLog[1]; aLog[2] = aLog[0]; aLog[0] = aLog[1] = 0; }else{ aLog[2] = aLog[3] = 0; } }else{ aLog[5] = aLog[1]; aLog[4] = aLog[0]; aLog[0] = aLog[1] = 0; pLog->snapshot.iHashSide = (pLog->snapshot.iHashSide + 1) % 2; } } aLog[5] = iLast; return btLogHashRollback(pLog, btLogFrameHash(pLog, iLast), iLast); } /* ** Run log recovery. In other words, read the log file from disk and ** initialize the shared-memory accordingly. */ static int btLogRecover(BtLog *pLog){ bt_env *pVfs = pLog->pLock->pVfs; |
︙ | ︙ | |||
521 522 523 524 525 526 527 | pHdr = &hdr1; iSlot = 1; } } if( rc==SQLITE4_NOTFOUND ) rc = SQLITE4_OK; } | | | | > > > > > > > > | > | > > > > > | < | > | > | < < > | 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 | pHdr = &hdr1; iSlot = 1; } } if( rc==SQLITE4_NOTFOUND ) rc = SQLITE4_OK; } /* If a header was successfully read from the file, attempt to ** recover frames from the log file. */ if( pHdr ){ /* The following iterates through all readable frames in the log file. ** It populates pLog->snapshot.aLog[] with the log topology and the ** shared hash-tables with the pgno->frame mapping. The FrameRecoverCtx ** object is populated with the frame number and "next frame" pointer of ** the last commit-frame in the log (if any). Additionally, the ** pLog->snapshot.aFrameCksum[] variables are populated with the checksum ** beloging to the frame header of the last commit-frame in the log. */ FrameRecoverCtx ctx = {0, 0}; rc = btLogTraverse(pLog, pHdr, btLogRecoverFrame, (void*)&ctx); if( rc==SQLITE4_OK ){ if( ctx.iLast==0 ){ /* No transactions recovered from the log file. */ btLogZeroSnapshot(pLog); }else{ /* One or more transactions were recovered from the log file. */ BtShm *pShm = btLogShm(pLog); pShm->ckpt.iWalHdr = (iSlot<<2) + pHdr->iCnt; pShm->ckpt.iFirstRead = pHdr->iFirstFrame; pShm->ckpt.iFirstRecover = pHdr->iFirstFrame; rc = btLogRollbackRecovery(pLog, &ctx); pLog->snapshot.iNextFrame = ctx.iNextFrame; } } } return rc; } /* |
︙ | ︙ | |||
561 562 563 564 565 566 567 568 569 570 571 572 573 574 | pLog = sqlite4_malloc(pEnv, sizeof(BtLog)); if( pLog==0 ){ rc = SQLITE4_NOMEM; goto open_out; } memset(pLog, 0, sizeof(BtLog)); pLog->pLock = (BtLock*)pPager; zWal = sqlite4BtPagerFilename(pPager, BT_PAGERFILE_LOG); rc = pVfs->xOpen(pEnv, pVfs, zWal, 0, &pLog->pFd); if( rc==SQLITE4_OK && bRecover ){ rc = btLogMapShm(pLog, 0); if( rc==SQLITE4_OK ){ | > | 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 | pLog = sqlite4_malloc(pEnv, sizeof(BtLog)); if( pLog==0 ){ rc = SQLITE4_NOMEM; goto open_out; } memset(pLog, 0, sizeof(BtLog)); pLog->pLock = (BtLock*)pPager; pLog->nWrapLog = BT_NWRAPLOG; zWal = sqlite4BtPagerFilename(pPager, BT_PAGERFILE_LOG); rc = pVfs->xOpen(pEnv, pVfs, zWal, 0, &pLog->pFd); if( rc==SQLITE4_OK && bRecover ){ rc = btLogMapShm(pLog, 0); if( rc==SQLITE4_OK ){ |
︙ | ︙ | |||
627 628 629 630 631 632 633 | /* Write the object to disk */ iOff = iHdr * pLog->snapshot.nSector; rc = btLogWriteData(pLog, iOff, (u8*)pHdr, sizeof(BtWalHdr)); return rc; } | | > > > > > > | | 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 | /* Write the object to disk */ iOff = iHdr * pLog->snapshot.nSector; rc = btLogWriteData(pLog, iOff, (u8*)pHdr, sizeof(BtWalHdr)); return rc; } static int btLogHashSearch( BtLog *pLog, /* Log module handle */ int iSide, /* 0 or 1 - the side of hash table to read */ int iHash, /* Index of hash to query */ u32 pgno, /* query for this page number */ u32 *piFrame /* OUT: Frame number for matching entry */ ){ ht_slot *aHash; u32 *aPgno; u32 iZero; int rc; rc = btLogFindHash(pLog, iSide, iHash, &aHash, &aPgno, &iZero); if( rc==SQLITE4_OK ){ int nCollide = HASHTABLE_NSLOT*2; int iSlot; u32 iFrame = 0; iSlot=btLogHashKey(pLog, pgno); for( ; aHash[iSlot]; iSlot=btLogHashNext(pLog, iSlot)){ |
︙ | ︙ | |||
656 657 658 659 660 661 662 | rc = SQLITE4_NOTFOUND; } } return rc; } | < < < > > > > > > > > > | | > > | | > > > > | 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 | rc = SQLITE4_NOTFOUND; } } return rc; } /* ** Attempt to read data for page pgno from the log file. If successful, ** the data is written into buffer aData[] (which must be at least as ** large as a database page). In this case SQLITE4_OK is returned. ** ** If the log does not contain any version of page pgno, SQLITE4_NOTFOUND ** is returned and the contents of buffer aData[] are not modified. ** ** If any other error occurs, an SQLite4 error code is returned. The final ** state of buffer aData[] is undefined in this case. */ int sqlite4BtLogRead(BtLog *pLog, u32 pgno, u8 *aData){ const int pgsz = sqlite4BtPagerPagesize((BtPager*)(pLog->pLock)); int rc = SQLITE4_NOTFOUND; u32 iFrame = 0; int i; /* Loop through regions (c), (b) and (a) of the log file. In that order. */ for(i=2; i>=0; i--){ u32 iLo = pLog->snapshot.aLog[i*2+0]; u32 iHi = pLog->snapshot.aLog[i*2+1]; int iSide; int iHash; int iHashLast; iHash = btLogFrameHash(pLog, iHi); iHashLast = btLogFrameHash(pLog, iLo); iSide = (pLog->snapshot.iHashSide + (i==0)) % 2; for( ; rc==SQLITE4_NOTFOUND && iHash>=iHashLast && iFrame==0; iHash--){ rc = btLogHashSearch(pLog, iSide, iHash, pgno, &iFrame); if( rc==SQLITE4_OK && (iFrame<iLo || iFrame>iHi) ){ rc = SQLITE4_NOTFOUND; } } } if( rc==SQLITE4_OK && iFrame!=0 ){ bt_env *pVfs = pLog->pLock->pVfs; i64 iOff; assert( rc==SQLITE4_OK ); iOff = btLogFrameOffset(pLog, pgsz, iFrame); |
︙ | ︙ | |||
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 | int sqlite4BtLogWrite(BtLog *pLog, u32 pgno, u8 *aData, int bCommit){ const int pgsz = sqlite4BtPagerPagesize((BtPager*)(pLog->pLock)); int rc = SQLITE4_OK; u32 iFrame; /* Write this frame (numbered from 1) */ BtFrameHdr frame; /* Header for new frame */ u32 *a; /* Pointer to cksum of previous frame */ i64 iOff; /* Offset of log file to write to */ /* Handle a special case - if the log file is completely empty then ** this writer must write the first header into the WAL file. */ if( btLogIsEmpty(pLog) ){ BtWalHdr hdr; memset(&hdr, 0, sizeof(BtWalHdr)); hdr.iMagic = BT_WAL_MAGIC; hdr.iVersion = BT_WAL_VERSION; hdr.nSector = pLog->snapshot.nSector; hdr.nPgsz = pgsz; hdr.iSalt1 = 22; hdr.iSalt2 = 23; hdr.iFirstFrame = 1; rc = btLogWriteHeader(pLog, 0, &hdr); if( rc!=SQLITE4_OK ) return rc; pLog->snapshot.aFrameCksum[0] = hdr.iSalt1; pLog->snapshot.aFrameCksum[1] = hdr.iSalt2; } | > > > | | > > > > > > > > > > > > > > > > > > > > > > > > > | | | | | | | | | < | | > > > > > > > | | > > > > > > > > > > > > > > | 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 | int sqlite4BtLogWrite(BtLog *pLog, u32 pgno, u8 *aData, int bCommit){ const int pgsz = sqlite4BtPagerPagesize((BtPager*)(pLog->pLock)); int rc = SQLITE4_OK; u32 iFrame; /* Write this frame (numbered from 1) */ BtFrameHdr frame; /* Header for new frame */ u32 *a; /* Pointer to cksum of previous frame */ i64 iOff; /* Offset of log file to write to */ u32 iNextFrame; u32 *aLog = pLog->snapshot.aLog; /* Handle a special case - if the log file is completely empty then ** this writer must write the first header into the WAL file. */ if( btLogIsEmpty(pLog) ){ BtWalHdr hdr; memset(&hdr, 0, sizeof(BtWalHdr)); hdr.iMagic = BT_WAL_MAGIC; hdr.iVersion = BT_WAL_VERSION; hdr.nSector = pLog->snapshot.nSector; hdr.nPgsz = pgsz; hdr.iSalt1 = 22; hdr.iSalt2 = 23; hdr.iFirstFrame = 1; rc = btLogWriteHeader(pLog, 0, &hdr); if( rc!=SQLITE4_OK ) return rc; pLog->snapshot.aFrameCksum[0] = hdr.iSalt1; pLog->snapshot.aFrameCksum[1] = hdr.iSalt2; pLog->snapshot.iNextFrame = 1; } /* Figure out the offset to write the current frame to. */ iFrame = pLog->snapshot.iNextFrame; iOff = btLogFrameOffset(pLog, pgsz, iFrame); /* The current frame will be written to location pLog->snapshot.iNextFrame. ** This code determines where the following frame will be stored. There ** are three possibilities: ** ** 1) The next frame follows the current frame (this is the usual case). ** 2) The next frame is frame 1 - the log wraps around. ** 3) Following the current frame is a block of frames still in use. ** So the next frame will immediately follow this block. */ iNextFrame = pLog->snapshot.iNextFrame + 1; if( iFrame!=1 && aLog[0]==0 && aLog[2]==0 && aLog[4]!=0 && aLog[4]>pLog->nWrapLog ){ /* Case 2) It is possible to wrap the log around */ iNextFrame = 1; }else if( iNextFrame==aLog[0] ){ /* Case 3) It is necessary to jump over some existing log. */ iNextFrame = aLog[1]+1; } if( iNextFrame & 0x80000000 ){ rc = SQLITE4_FULL; }else{ /* Populate the frame header object. */ memset(&frame, 0, sizeof(frame)); frame.pgno = pgno; frame.ctrl = (bCommit ? BT_FRAME_COMMIT : 0) + iNextFrame; a = pLog->snapshot.aFrameCksum; btLogChecksum(1, (u8*)&frame, offsetof(BtFrameHdr,aCksum), a, frame.aCksum); btLogChecksum(1, aData, pgsz, frame.aCksum, frame.aCksum); #if 0 fprintf(stderr, "writing page %d at log offset %d (frame %d)\n", (int)pgno, (int)iOff, (int)iFrame); fflush(stderr); #endif /* Write the frame header to the log file. */ rc = btLogWriteData(pLog, iOff, (u8*)&frame, sizeof(frame)); } pLog->snapshot.iNextFrame = iNextFrame; /* Write the frame contents to the log file. */ if( rc==SQLITE4_OK ){ rc = btLogWriteData(pLog, iOff+sizeof(frame), aData, pgsz); } /* Update the wal index hash tables with the (pgno -> iFrame) record. */ if( rc==SQLITE4_OK ){ if( iFrame==1 ){ pLog->snapshot.iHashSide = (pLog->snapshot.iHashSide+1) %2; } rc = btLogHashInsert(pLog, pgno, iFrame); } /* Update the private copy of the shm-header */ if( rc==SQLITE4_OK ){ btLogDebugTopology("log1", aLog); if( btLogIsEmpty(pLog) ){ assert( iFrame==1 ); aLog[4] = iFrame; }else if( iFrame==1 ){ assert( aLog[0]==0 && aLog[1]==0 && aLog[2]==0 && aLog[3]==0 ); aLog[0] = aLog[4]; aLog[1] = aLog[5]; aLog[4] = iFrame; }else if( iFrame!=aLog[5]+1 ){ assert( iFrame>aLog[5] ); assert( aLog[2]==0 && aLog[3]==0 ); aLog[2] = aLog[4]; aLog[3] = aLog[5]; aLog[4] = iFrame; } aLog[5] = iFrame; memcpy(pLog->snapshot.aFrameCksum, frame.aCksum, sizeof(frame.aCksum)); btLogDebugTopology("log2", aLog); } /* If this is a COMMIT, also update the shared shm-header. */ if( bCommit ){ rc = btLogUpdateSharedHdr(pLog); } |
︙ | ︙ | |||
833 834 835 836 837 838 839 840 | if( rc==SQLITE4_OK && memcmp(&shmhdr, &pLog->snapshot, sizeof(BtShmHdr)) ){ sqlite4BtLockReaderUnlock(pLog->pLock); rc = SQLITE4_NOTFOUND; } } if( rc==SQLITE4_OK ){ BtShm *pShm = btLogShm(pLog); | > > | | > > > > > > | > > > > | > > > > | 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 | if( rc==SQLITE4_OK && memcmp(&shmhdr, &pLog->snapshot, sizeof(BtShmHdr)) ){ sqlite4BtLockReaderUnlock(pLog->pLock); rc = SQLITE4_NOTFOUND; } } if( rc==SQLITE4_OK ){ int iRegion; u32 *aLog = pLog->snapshot.aLog; BtShm *pShm = btLogShm(pLog); u32 iCkpt = pShm->ckpt.iFirstRecover; fprintf(stderr, "iCkpt=%d\n", (int)iCkpt); btLogDebugTopology("log3", aLog); for(iRegion=0; iRegion<3; iRegion++){ if( aLog[iRegion*2] ){ if( iCkpt>=aLog[iRegion*2] && iCkpt<=aLog[iRegion*2+1] ){ aLog[iRegion*2] = iCkpt; break; }else{ aLog[iRegion*2] = 0; aLog[iRegion*2+1] = 0; } } } btLogDebugTopology("log4", aLog); } return rc; } int sqlite4BtLogSnapshotClose(BtLog *pLog){ sqlite4BtLockReaderUnlock(pLog->pLock); |
︙ | ︙ | |||
905 906 907 908 909 910 911 | /* ** Parameters iFirst and iLast are frame numbers for frames that are part ** of the current log. This function scans the wal-index from iFirst to ** iLast (inclusive) and records the set of page numbers that occur once. ** This set is sorted in ascending order and returned via the output ** variables *paPgno and *pnPgno. | < < < | > > | > > > > > > > > > > > > > > | > | | | > > > > > | | | > > > | 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 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 | /* ** Parameters iFirst and iLast are frame numbers for frames that are part ** of the current log. This function scans the wal-index from iFirst to ** iLast (inclusive) and records the set of page numbers that occur once. ** This set is sorted in ascending order and returned via the output ** variables *paPgno and *pnPgno. */ static int btLogGatherPgno( BtLog *pLog, /* Log module handle */ u32 **paPgno, /* OUT: s4_malloc'd array of sorted pgno */ int *pnPgno, /* OUT: Number of entries in *paPgno */ u32 *piLastFrame ){ u32 *aLog = pLog->snapshot.aLog;/* Log file topology */ u32 i; u32 *aPgno; /* Returned array */ u32 *aSpace; /* Temporary space used by merge-sort */ int nMax; int rc = SQLITE4_OK; int iRegion; /* Determine an upper limit on the number of distinct page numbers. This ** limit is used to allocate space for the returned array. */ nMax = 0; for(iRegion=0; iRegion<3; iRegion++){ if( aLog[iRegion*2] ){ nMax += 1 + aLog[iRegion*2+1] - aLog[iRegion*2+0]; } } /* Allocate space to collect all page numbers. */ aPgno = (u32*)sqlite4_malloc(pLog->pLock->pEnv, sizeof(u32)*nMax*2); if( aPgno==0 ) rc = btErrorBkpt(SQLITE4_NOMEM); aSpace = &aPgno[nMax]; /* Copy the required page numbers into the allocated array */ for(iRegion=0; iRegion<3; iRegion++){ u32 iFirst = aLog[iRegion*2]; u32 iLast = aLog[iRegion*2+1]; if( iFirst ){ for(i=iFirst; rc==SQLITE4_OK && i<=iLast; i++){ int iHash = btLogFrameHash(pLog, i); u32 *aPage; ht_slot *aHash; u32 iZero; /* It doesn't matter which 'side' of the hash table is requested here, ** as only the page-number array, not the aHash[] table, will be used. ** And it is the same for both sides. Hence the constant 0 passed as ** the second argument to btLogFindHash(). */ rc = btLogFindHash(pLog, 0, iHash, &aHash, &aPage, &iZero); if( rc==SQLITE4_OK ){ aPgno[i-iFirst] = aPage[i-iZero]; } } *piLastFrame = iLast; } } /* Sort the contents of the array in ascending order. This step also ** eliminates any duplicate page numbers. */ if( rc==SQLITE4_OK ){ btLogMergeSort(aPgno, &nMax, aSpace); |
︙ | ︙ | |||
970 971 972 973 974 975 976 | /* Take the CHECKPOINTER lock. */ rc = sqlite4BtLockCkpt(pLock); if( rc==SQLITE4_OK ){ const int pgsz = sqlite4BtPagerPagesize((BtPager*)pLock); bt_env *pVfs = pLock->pVfs; bt_file *pFd = pLock->pFd; BtShm *pShm; /* Pointer to shared-memory region */ | < > > < < < | > > > > > > | < < | < < < | | | < | | 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 | /* Take the CHECKPOINTER lock. */ rc = sqlite4BtLockCkpt(pLock); if( rc==SQLITE4_OK ){ const int pgsz = sqlite4BtPagerPagesize((BtPager*)pLock); bt_env *pVfs = pLock->pVfs; bt_file *pFd = pLock->pFd; BtShm *pShm; /* Pointer to shared-memory region */ u32 iLast; /* Last frame to checkpoint */ BtFrameHdr fhdr; /* Frame header of frame iLast */ u32 *aPgno = 0; /* Array of page numbers to checkpoint */ int nPgno; /* Number of entries in aPgno[] */ int i; /* Used to loop through aPgno[] */ u8 *aBuf; /* Buffer to load page data into */ u32 iFirstRead; /* First frame not checkpointed */ /* Allocate space to load log data into */ aBuf = sqlite4_malloc(pLock->pEnv, pgsz); if( aBuf==0 ) rc = btErrorBkpt(SQLITE4_NOMEM); /* Figure out the set of page numbers stored in the part of the log ** file being checkpointed. Remove any duplicates and sort them in ** ascending order. */ if( rc==SQLITE4_OK ){ rc = btLogGatherPgno(pLog, &aPgno, &nPgno, &iLast); } if( rc==SQLITE4_OK ){ i64 iOff = btLogFrameOffset(pLog, pgsz, iLast); rc = btLogReadData(pLog, iOff, (u8*)&fhdr, sizeof(BtFrameHdr)); iFirstRead = (fhdr.ctrl & ~BT_FRAME_COMMIT); } /* Copy data from the log file to the database file. */ for(i=0; rc==SQLITE4_OK && i<nPgno; i++){ u32 pgno = aPgno[i]; rc = sqlite4BtLogRead(pLog, pgno, aBuf); if( rc==SQLITE4_OK ){ i64 iOff = (i64)pgsz * (pgno-1); rc = pVfs->xWrite(pFd, iOff, aBuf, pgsz); } } /* Update the first field of the checkpoint-header. This tells readers ** that they need not consider anything that in the log before this ** point (since the data has already been copied into the database ** file). */ if( rc==SQLITE4_OK ){ pShm = btLogShm(pLog); pShm->ckpt.iFirstRead = iFirstRead; pVfs->xShmBarrier(pLog->pFd); } /* Write a new header into the log file. This tells any future recovery ** where it should start reading the log. Once this new header is synced ** to disk, the space cleared by this checkpoint operation can be ** reused. */ if( rc==SQLITE4_OK ){ int iSlot = ((pShm->ckpt.iWalHdr >> 2) + 1) % 2; BtWalHdr hdr; memset(&hdr, 0, sizeof(BtWalHdr)); hdr.iMagic = BT_WAL_MAGIC; hdr.iVersion = BT_WAL_VERSION; hdr.iCnt = (((pShm->ckpt.iWalHdr & 0x03) + 1) % 3); hdr.nSector = pLog->snapshot.nSector; hdr.nPgsz = pgsz; hdr.iFirstFrame = iFirstRead; hdr.iSalt1 = fhdr.aCksum[0]; hdr.iSalt2 = fhdr.aCksum[1]; rc = btLogWriteHeader(pLog, iSlot, &hdr); if( rc==SQLITE4_OK ){ pShm->ckpt.iWalHdr = (iSlot<<2) + hdr.iCnt; } } /* Update the second field of the checkpoint header. This tells future ** writers that it is now safe to recycle pages before this point ** (assuming all live readers are cleared). */ if( rc==SQLITE4_OK ){ pShm->ckpt.iFirstRecover = iFirstRead; pVfs->xShmBarrier(pLog->pFd); } /* Free the buffer and drop the checkpointer lock */ sqlite4_free(pLock->pEnv, aBuf); sqlite4BtLockCkptUnlock(pLog->pLock); } return rc; } |