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Overview
Comment: | Remove the unused PGHDR_NEED_READ flag. Add invariant checking (during SQLITE_DEBUG builds only) for the PgHdr object. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA1: |
771c5411e9ebcad00fb4b97556b51948 |
User & Date: | drh 2016-05-13 15:22:06.587 |
Context
2016-05-13
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17:22 | Improvements to a comment in the pcache.c file. No changes to code. (check-in: b369980f0c user: drh tags: trunk) | |
15:22 | Remove the unused PGHDR_NEED_READ flag. Add invariant checking (during SQLITE_DEBUG builds only) for the PgHdr object. (check-in: 771c5411e9 user: drh tags: trunk) | |
12:12 | Clarification of the pagerFlushOnCommit() logic. (check-in: 3401d9dcdb user: drh tags: trunk) | |
Changes
Changes to src/pager.c.
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2373 2374 2375 2376 2377 2378 2379 | assert( isSavepnt ); assert( (pPager->doNotSpill & SPILLFLAG_ROLLBACK)==0 ); pPager->doNotSpill |= SPILLFLAG_ROLLBACK; rc = sqlite3PagerGet(pPager, pgno, &pPg, 1); assert( (pPager->doNotSpill & SPILLFLAG_ROLLBACK)!=0 ); pPager->doNotSpill &= ~SPILLFLAG_ROLLBACK; if( rc!=SQLITE_OK ) return rc; | < | 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 | assert( isSavepnt ); assert( (pPager->doNotSpill & SPILLFLAG_ROLLBACK)==0 ); pPager->doNotSpill |= SPILLFLAG_ROLLBACK; rc = sqlite3PagerGet(pPager, pgno, &pPg, 1); assert( (pPager->doNotSpill & SPILLFLAG_ROLLBACK)!=0 ); pPager->doNotSpill &= ~SPILLFLAG_ROLLBACK; if( rc!=SQLITE_OK ) return rc; sqlite3PcacheMakeDirty(pPg); } if( pPg ){ /* No page should ever be explicitly rolled back that is in use, except ** for page 1 which is held in use in order to keep the lock on the ** database active. However such a page may be rolled back as a result ** of an internal error resulting in an automatic call to |
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6001 6002 6003 6004 6005 6006 6007 6008 6009 6010 6011 6012 6013 6014 | void sqlite3PagerDontWrite(PgHdr *pPg){ Pager *pPager = pPg->pPager; if( !pPager->tempFile && (pPg->flags&PGHDR_DIRTY) && pPager->nSavepoint==0 ){ PAGERTRACE(("DONT_WRITE page %d of %d\n", pPg->pgno, PAGERID(pPager))); IOTRACE(("CLEAN %p %d\n", pPager, pPg->pgno)) pPg->flags |= PGHDR_DONT_WRITE; pPg->flags &= ~PGHDR_WRITEABLE; pager_set_pagehash(pPg); } } /* ** This routine is called to increment the value of the database file ** change-counter, stored as a 4-byte big-endian integer starting at | > | 6000 6001 6002 6003 6004 6005 6006 6007 6008 6009 6010 6011 6012 6013 6014 | void sqlite3PagerDontWrite(PgHdr *pPg){ Pager *pPager = pPg->pPager; if( !pPager->tempFile && (pPg->flags&PGHDR_DIRTY) && pPager->nSavepoint==0 ){ PAGERTRACE(("DONT_WRITE page %d of %d\n", pPg->pgno, PAGERID(pPager))); IOTRACE(("CLEAN %p %d\n", pPager, pPg->pgno)) pPg->flags |= PGHDR_DONT_WRITE; pPg->flags &= ~PGHDR_WRITEABLE; testcase( pPg->flags & PGHDR_NEED_SYNC ); pager_set_pagehash(pPg); } } /* ** This routine is called to increment the value of the database file ** change-counter, stored as a 4-byte big-endian integer starting at |
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Changes to src/pcache.c.
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49 50 51 52 53 54 55 56 | u8 bPurgeable; /* True if pages are on backing store */ u8 eCreate; /* eCreate value for for xFetch() */ int (*xStress)(void*,PgHdr*); /* Call to try make a page clean */ void *pStress; /* Argument to xStress */ sqlite3_pcache *pCache; /* Pluggable cache module */ }; /* | > | > > > > > | > | > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > | 49 50 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 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 | u8 bPurgeable; /* True if pages are on backing store */ u8 eCreate; /* eCreate value for for xFetch() */ int (*xStress)(void*,PgHdr*); /* Call to try make a page clean */ void *pStress; /* Argument to xStress */ sqlite3_pcache *pCache; /* Pluggable cache module */ }; /********************************** Test and Debug Logic **********************/ /* ** Debug tracing macros. Enable by by changing the "0" to "1" and ** recompiling. ** ** When sqlite3PcacheTrace is 1, single line trace messages are issued. ** When sqlite3PcacheTrace is 2, a dump of the pcache showing all cache entries ** is displayed for many operations, resulting in a lot of output. */ #if defined(SQLITE_DEBUG) && 0 int sqlite3PcacheTrace = 2; /* 0: off 1: simple 2: cache dumps */ int sqlite3PcacheMxDump = 9999; /* Max cache entries for pcacheDump() */ # define pcacheTrace(X) if(sqlite3PcacheTrace){sqlite3DebugPrintf X;} void pcacheDump(PCache *pCache){ int N; int i, j; sqlite3_pcache_page *pLower; PgHdr *pPg; unsigned char *a; if( sqlite3PcacheTrace<2 ) return; if( pCache->pCache==0 ) return; N = sqlite3PcachePagecount(pCache); if( N>sqlite3PcacheMxDump ) N = sqlite3PcacheMxDump; for(i=1; i<=N; i++){ pLower = sqlite3GlobalConfig.pcache2.xFetch(pCache->pCache, i, 0); if( pLower==0 ) continue; pPg = (PgHdr*)pLower->pExtra; printf("%3d: nRef %2d flgs %02x data ", i, pPg->nRef, pPg->flags); a = (unsigned char *)pLower->pBuf; for(j=0; j<12; j++) printf("%02x", a[j]); printf("\n"); if( pPg->pPage==0 ){ sqlite3GlobalConfig.pcache2.xUnpin(pCache->pCache, pLower, 0); } } } #else # define pcacheTrace(X) # define pcacheDump(X) #endif /* ** Check invariants on a PgHdr entry. Return true if everything is OK. ** Return false if any invariant is violated. ** ** This routine is for use inside of assert() statements only. For ** example: ** ** assert( sqlite3PcachePageSanity(pPg) ); */ #if SQLITE_DEBUG int sqlite3PcachePageSanity(PgHdr *pPg){ PCache *pCache; assert( pPg!=0 ); assert( pPg->pgno>0 ); /* Page number is 1 or more */ pCache = pPg->pCache; assert( pCache!=0 ); /* Every page has an associated PCache */ if( pPg->flags & PGHDR_CLEAN ){ assert( (pPg->flags & PGHDR_DIRTY)==0 );/* Cannot be both CLEAN and DIRTY */ assert( pCache->pDirty!=pPg ); /* CLEAN pages not on dirty list */ assert( pCache->pDirtyTail!=pPg ); } /* WRITEABLE pages must also be DIRTY */ if( pPg->flags & PGHDR_WRITEABLE ){ assert( pPg->flags & PGHDR_DIRTY ); /* WRITEABLE implies DIRTY */ } /* NEED_SYNC can be set independently of WRITEABLE. This can happen, ** for example, when using the sqlite3PagerDontWrite() optimization: ** (1) Page X is journalled, and gets WRITEABLE and NEED_SEEK. ** (2) Page X moved to freelist, WRITEABLE is cleared ** (3) Page X reused, WRITEABLE is set again ** If NEED_SYNC had been cleared in step 2, then it would not be reset ** in step 3, and page might be written into the database without first ** syncing the rollback journal, which might cause corruption on a power ** loss. */ return 1; } #endif /* SQLITE_DEBUG */ /********************************** Linked List Management ********************/ /* Allowed values for second argument to pcacheManageDirtyList() */ #define PCACHE_DIRTYLIST_REMOVE 1 /* Remove pPage from dirty list */ #define PCACHE_DIRTYLIST_ADD 2 /* Add pPage to the dirty list */ #define PCACHE_DIRTYLIST_FRONT 3 /* Move pPage to the front of the list */ |
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435 436 437 438 439 440 441 442 443 444 445 446 447 448 | pPgHdr = (PgHdr *)pPage->pExtra; if( !pPgHdr->pPage ){ return pcacheFetchFinishWithInit(pCache, pgno, pPage); } pCache->nRefSum++; pPgHdr->nRef++; return pPgHdr; } /* ** Decrement the reference count on a page. If the page is clean and the ** reference count drops to 0, then it is made eligible for recycling. */ | > | 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 | pPgHdr = (PgHdr *)pPage->pExtra; if( !pPgHdr->pPage ){ return pcacheFetchFinishWithInit(pCache, pgno, pPage); } pCache->nRefSum++; pPgHdr->nRef++; assert( sqlite3PcachePageSanity(pPgHdr) ); return pPgHdr; } /* ** Decrement the reference count on a page. If the page is clean and the ** reference count drops to 0, then it is made eligible for recycling. */ |
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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 | } /* ** Increase the reference count of a supplied page by 1. */ void sqlite3PcacheRef(PgHdr *p){ assert(p->nRef>0); p->nRef++; p->pCache->nRefSum++; } /* ** Drop a page from the cache. There must be exactly one reference to the ** page. This function deletes that reference, so after it returns the ** page pointed to by p is invalid. */ void sqlite3PcacheDrop(PgHdr *p){ assert( p->nRef==1 ); if( p->flags&PGHDR_DIRTY ){ pcacheManageDirtyList(p, PCACHE_DIRTYLIST_REMOVE); } p->pCache->nRefSum--; sqlite3GlobalConfig.pcache2.xUnpin(p->pCache->pCache, p->pPage, 1); } /* ** Make sure the page is marked as dirty. If it isn't dirty already, ** make it so. */ void sqlite3PcacheMakeDirty(PgHdr *p){ assert( p->nRef>0 ); if( p->flags & (PGHDR_CLEAN|PGHDR_DONT_WRITE) ){ /*OPTIMIZATION-IF-FALSE*/ p->flags &= ~PGHDR_DONT_WRITE; if( p->flags & PGHDR_CLEAN ){ p->flags ^= (PGHDR_DIRTY|PGHDR_CLEAN); pcacheTrace(("%p.DIRTY %d\n",p->pCache,p->pgno)); assert( (p->flags & (PGHDR_DIRTY|PGHDR_CLEAN))==PGHDR_DIRTY ); pcacheManageDirtyList(p, PCACHE_DIRTYLIST_ADD); } } } /* ** Make sure the page is marked as clean. If it isn't clean already, ** make it so. */ void sqlite3PcacheMakeClean(PgHdr *p){ if( ALWAYS((p->flags & PGHDR_DIRTY)!=0) ){ assert( (p->flags & PGHDR_CLEAN)==0 ); pcacheManageDirtyList(p, PCACHE_DIRTYLIST_REMOVE); p->flags &= ~(PGHDR_DIRTY|PGHDR_NEED_SYNC|PGHDR_WRITEABLE); p->flags |= PGHDR_CLEAN; pcacheTrace(("%p.CLEAN %d\n",p->pCache,p->pgno)); if( p->nRef==0 ){ pcacheUnpin(p); } } } /* | > > > > > > | 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 | } /* ** Increase the reference count of a supplied page by 1. */ void sqlite3PcacheRef(PgHdr *p){ assert(p->nRef>0); assert( sqlite3PcachePageSanity(p) ); p->nRef++; p->pCache->nRefSum++; } /* ** Drop a page from the cache. There must be exactly one reference to the ** page. This function deletes that reference, so after it returns the ** page pointed to by p is invalid. */ void sqlite3PcacheDrop(PgHdr *p){ assert( p->nRef==1 ); assert( sqlite3PcachePageSanity(p) ); if( p->flags&PGHDR_DIRTY ){ pcacheManageDirtyList(p, PCACHE_DIRTYLIST_REMOVE); } p->pCache->nRefSum--; sqlite3GlobalConfig.pcache2.xUnpin(p->pCache->pCache, p->pPage, 1); } /* ** Make sure the page is marked as dirty. If it isn't dirty already, ** make it so. */ void sqlite3PcacheMakeDirty(PgHdr *p){ assert( p->nRef>0 ); assert( sqlite3PcachePageSanity(p) ); if( p->flags & (PGHDR_CLEAN|PGHDR_DONT_WRITE) ){ /*OPTIMIZATION-IF-FALSE*/ p->flags &= ~PGHDR_DONT_WRITE; if( p->flags & PGHDR_CLEAN ){ p->flags ^= (PGHDR_DIRTY|PGHDR_CLEAN); pcacheTrace(("%p.DIRTY %d\n",p->pCache,p->pgno)); assert( (p->flags & (PGHDR_DIRTY|PGHDR_CLEAN))==PGHDR_DIRTY ); pcacheManageDirtyList(p, PCACHE_DIRTYLIST_ADD); } assert( sqlite3PcachePageSanity(p) ); } } /* ** Make sure the page is marked as clean. If it isn't clean already, ** make it so. */ void sqlite3PcacheMakeClean(PgHdr *p){ assert( sqlite3PcachePageSanity(p) ); if( ALWAYS((p->flags & PGHDR_DIRTY)!=0) ){ assert( (p->flags & PGHDR_CLEAN)==0 ); pcacheManageDirtyList(p, PCACHE_DIRTYLIST_REMOVE); p->flags &= ~(PGHDR_DIRTY|PGHDR_NEED_SYNC|PGHDR_WRITEABLE); p->flags |= PGHDR_CLEAN; pcacheTrace(("%p.CLEAN %d\n",p->pCache,p->pgno)); assert( sqlite3PcachePageSanity(p) ); if( p->nRef==0 ){ pcacheUnpin(p); } } } /* |
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556 557 558 559 560 561 562 563 564 565 566 567 568 569 | /* ** Change the page number of page p to newPgno. */ void sqlite3PcacheMove(PgHdr *p, Pgno newPgno){ PCache *pCache = p->pCache; assert( p->nRef>0 ); assert( newPgno>0 ); pcacheTrace(("%p.MOVE %d -> %d\n",pCache,p->pgno,newPgno)); sqlite3GlobalConfig.pcache2.xRekey(pCache->pCache, p->pPage, p->pgno,newPgno); p->pgno = newPgno; if( (p->flags&PGHDR_DIRTY) && (p->flags&PGHDR_NEED_SYNC) ){ pcacheManageDirtyList(p, PCACHE_DIRTYLIST_FRONT); } } | > | 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 | /* ** Change the page number of page p to newPgno. */ void sqlite3PcacheMove(PgHdr *p, Pgno newPgno){ PCache *pCache = p->pCache; assert( p->nRef>0 ); assert( newPgno>0 ); assert( sqlite3PcachePageSanity(p) ); pcacheTrace(("%p.MOVE %d -> %d\n",pCache,p->pgno,newPgno)); sqlite3GlobalConfig.pcache2.xRekey(pCache->pCache, p->pPage, p->pgno,newPgno); p->pgno = newPgno; if( (p->flags&PGHDR_DIRTY) && (p->flags&PGHDR_NEED_SYNC) ){ pcacheManageDirtyList(p, PCACHE_DIRTYLIST_FRONT); } } |
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Changes to src/pcache.h.
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47 48 49 50 51 52 53 | /* Bit values for PgHdr.flags */ #define PGHDR_CLEAN 0x001 /* Page not on the PCache.pDirty list */ #define PGHDR_DIRTY 0x002 /* Page is on the PCache.pDirty list */ #define PGHDR_WRITEABLE 0x004 /* Journaled and ready to modify */ #define PGHDR_NEED_SYNC 0x008 /* Fsync the rollback journal before ** writing this page to the database */ | < | | | | 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 | /* Bit values for PgHdr.flags */ #define PGHDR_CLEAN 0x001 /* Page not on the PCache.pDirty list */ #define PGHDR_DIRTY 0x002 /* Page is on the PCache.pDirty list */ #define PGHDR_WRITEABLE 0x004 /* Journaled and ready to modify */ #define PGHDR_NEED_SYNC 0x008 /* Fsync the rollback journal before ** writing this page to the database */ #define PGHDR_DONT_WRITE 0x010 /* Do not write content to disk */ #define PGHDR_MMAP 0x020 /* This is an mmap page object */ #define PGHDR_WAL_APPEND 0x040 /* Appended to wal file */ /* Initialize and shutdown the page cache subsystem */ int sqlite3PcacheInitialize(void); void sqlite3PcacheShutdown(void); /* Page cache buffer management: ** These routines implement SQLITE_CONFIG_PAGECACHE. |
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133 134 135 136 137 138 139 140 141 142 143 144 145 146 | #if defined(SQLITE_CHECK_PAGES) || defined(SQLITE_DEBUG) /* Iterate through all dirty pages currently stored in the cache. This ** interface is only available if SQLITE_CHECK_PAGES is defined when the ** library is built. */ void sqlite3PcacheIterateDirty(PCache *pCache, void (*xIter)(PgHdr *)); #endif /* Set and get the suggested cache-size for the specified pager-cache. ** ** If no global maximum is configured, then the system attempts to limit ** the total number of pages cached by purgeable pager-caches to the sum ** of the suggested cache-sizes. */ | > > > > > | 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 | #if defined(SQLITE_CHECK_PAGES) || defined(SQLITE_DEBUG) /* Iterate through all dirty pages currently stored in the cache. This ** interface is only available if SQLITE_CHECK_PAGES is defined when the ** library is built. */ void sqlite3PcacheIterateDirty(PCache *pCache, void (*xIter)(PgHdr *)); #endif #if defined(SQLITE_DEBUG) /* Check invariants on a PgHdr object */ int sqlite3PcachePageSanity(PgHdr*); #endif /* Set and get the suggested cache-size for the specified pager-cache. ** ** If no global maximum is configured, then the system attempts to limit ** the total number of pages cached by purgeable pager-caches to the sum ** of the suggested cache-sizes. */ |
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