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Overview
Comment: | Further updates to the sqlite3_pcache_methods documentation, plus the addition of a few evidence marks related to pcache. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA1: |
34edb54bb03ad4e54f2e4de12d767e6f |
User & Date: | drh 2010-09-09 18:25:34.000 |
Context
2010-09-09
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19:02 | Add test cases to e_select.test. (check-in: 5e73f7b2b7 user: dan tags: trunk) | |
18:25 | Further updates to the sqlite3_pcache_methods documentation, plus the addition of a few evidence marks related to pcache. (check-in: 34edb54bb0 user: drh tags: trunk) | |
17:43 | Make sure memory statistics are enabled for the dbstatus.test script. (check-in: 35b943a0fc user: drh tags: trunk) | |
Changes
Changes to src/main.c.
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169 170 171 172 173 174 175 176 177 178 179 180 181 182 | } /* Do the rest of the initialization under the recursive mutex so ** that we will be able to handle recursive calls into ** sqlite3_initialize(). The recursive calls normally come through ** sqlite3_os_init() when it invokes sqlite3_vfs_register(), but other ** recursive calls might also be possible. */ sqlite3_mutex_enter(sqlite3GlobalConfig.pInitMutex); if( sqlite3GlobalConfig.isInit==0 && sqlite3GlobalConfig.inProgress==0 ){ FuncDefHash *pHash = &GLOBAL(FuncDefHash, sqlite3GlobalFunctions); sqlite3GlobalConfig.inProgress = 1; memset(pHash, 0, sizeof(sqlite3GlobalFunctions)); sqlite3RegisterGlobalFunctions(); | > > > > > > > | 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 | } /* Do the rest of the initialization under the recursive mutex so ** that we will be able to handle recursive calls into ** sqlite3_initialize(). The recursive calls normally come through ** sqlite3_os_init() when it invokes sqlite3_vfs_register(), but other ** recursive calls might also be possible. ** ** IMPLEMENTATION-OF: R-00140-37445 SQLite automatically serializes calls ** to the xInit method, so the xInit method need not be threadsafe. ** ** The following mutex is what serializes access to the appdef pcache xInit ** methods. The sqlite3_pcache_methods.xInit() all is embedded in the ** call to sqlite3PcacheInitialize(). */ sqlite3_mutex_enter(sqlite3GlobalConfig.pInitMutex); if( sqlite3GlobalConfig.isInit==0 && sqlite3GlobalConfig.inProgress==0 ){ FuncDefHash *pHash = &GLOBAL(FuncDefHash, sqlite3GlobalFunctions); sqlite3GlobalConfig.inProgress = 1; memset(pHash, 0, sizeof(sqlite3GlobalFunctions)); sqlite3RegisterGlobalFunctions(); |
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Changes to src/pcache.c.
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138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 | /*************************************************** General Interfaces ****** ** ** Initialize and shutdown the page cache subsystem. Neither of these ** functions are threadsafe. */ int sqlite3PcacheInitialize(void){ if( sqlite3GlobalConfig.pcache.xInit==0 ){ sqlite3PCacheSetDefault(); } return sqlite3GlobalConfig.pcache.xInit(sqlite3GlobalConfig.pcache.pArg); } void sqlite3PcacheShutdown(void){ if( sqlite3GlobalConfig.pcache.xShutdown ){ sqlite3GlobalConfig.pcache.xShutdown(sqlite3GlobalConfig.pcache.pArg); } } /* ** Return the size in bytes of a PCache object. */ | > > > > | 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 | /*************************************************** General Interfaces ****** ** ** Initialize and shutdown the page cache subsystem. Neither of these ** functions are threadsafe. */ int sqlite3PcacheInitialize(void){ if( sqlite3GlobalConfig.pcache.xInit==0 ){ /* IMPLEMENTATION-OF: R-26801-64137 If the xInit() method is NULL, then the ** built-in default page cache is used instead of the application defined ** page cache. */ sqlite3PCacheSetDefault(); } return sqlite3GlobalConfig.pcache.xInit(sqlite3GlobalConfig.pcache.pArg); } void sqlite3PcacheShutdown(void){ if( sqlite3GlobalConfig.pcache.xShutdown ){ /* IMPLEMENTATION-OF: R-26000-56589 The xShutdown() method may be NULL. */ sqlite3GlobalConfig.pcache.xShutdown(sqlite3GlobalConfig.pcache.pArg); } } /* ** Return the size in bytes of a PCache object. */ |
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Changes to src/sqlite.h.in.
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5437 5438 5439 5440 5441 5442 5443 | ** ** ^(The xInit() method is called once for each effective ** call to [sqlite3_initialize()])^ ** (usually only once during the lifetime of the process). ^(The xInit() ** method is passed a copy of the sqlite3_pcache_methods.pArg value.)^ ** The intent of the xInit() method is to set up global data structures ** required by the custom page cache implementation. | | < | > | 5437 5438 5439 5440 5441 5442 5443 5444 5445 5446 5447 5448 5449 5450 5451 5452 5453 | ** ** ^(The xInit() method is called once for each effective ** call to [sqlite3_initialize()])^ ** (usually only once during the lifetime of the process). ^(The xInit() ** method is passed a copy of the sqlite3_pcache_methods.pArg value.)^ ** The intent of the xInit() method is to set up global data structures ** required by the custom page cache implementation. ** ^(If the xInit() method is NULL, then the ** built-in default page cache is used instead of the application defined ** page cache.)^ ** ** ^The xShutdown() method is called by [sqlite3_shutdown()]. ** It can be used to clean up ** any outstanding resources before process shutdown, if required. ** ^The xShutdown() method may be NULL. ** ** ^SQLite automatically serializes calls to the xInit method, |
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5484 5485 5486 5487 5488 5489 5490 | ** ^(The xCachesize() method may be called at any time by SQLite to set the ** suggested maximum cache-size (number of pages stored by) the cache ** instance passed as the first argument. This is the value configured using ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable ** parameter, the implementation is not required to do anything with this ** value; it is advisory only. ** | | | | | | | | | | | | > | | < < | | < | | | | | | | | | 5484 5485 5486 5487 5488 5489 5490 5491 5492 5493 5494 5495 5496 5497 5498 5499 5500 5501 5502 5503 5504 5505 5506 5507 5508 5509 5510 5511 5512 5513 5514 5515 5516 5517 5518 5519 5520 5521 5522 5523 5524 5525 5526 5527 5528 5529 5530 5531 5532 5533 5534 5535 5536 5537 5538 5539 5540 5541 5542 5543 5544 5545 5546 5547 5548 5549 | ** ^(The xCachesize() method may be called at any time by SQLite to set the ** suggested maximum cache-size (number of pages stored by) the cache ** instance passed as the first argument. This is the value configured using ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable ** parameter, the implementation is not required to do anything with this ** value; it is advisory only. ** ** The xPagecount() method must return the number of pages currently ** stored in the cache, both pinned and unpinned. ** ** The xFetch() method locates a page in the cache and returns a pointer to ** the page, or a NULL pointer. ** A "page", in this context, means a buffer of szPage bytes aligned at an ** 8-byte boundary. The page to be fetched is determined by the key. ^The ** mimimum key value is 1. After it has been retrieved using xFetch, the page ** is considered to be "pinned". ** ** If the requested page is already in the page cache, then the page cache ** implementation must return a pointer to the page buffer with its content ** intact. If the requested page is not already in the cache, then the ** behavior of the cache implementation should use the value of the createFlag ** parameter to help it determined what action to take: ** ** <table border=1 width=85% align=center> ** <tr><th> createFlag <th> Behaviour when page is not already in cache ** <tr><td> 0 <td> Do not allocate a new page. Return NULL. ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. ** Otherwise return NULL. ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return ** NULL if allocating a new page is effectively impossible. ** </table> ** ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite ** will only use a createFlag of 2 after a prior call with a createFlag of 1 ** failed.)^ In between the to xFetch() calls, SQLite may ** attempt to unpin one or more cache pages by spilling the content of ** pinned pages to disk and synching the operating system disk cache. ** ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page ** as its second argument. If the third parameter, discard, is non-zero, ** then the page must be evicted from the cache. ** ^If the discard parameter is ** zero, then the page may be discarded or retained at the discretion of ** page cache implementation. ^The page cache implementation ** may choose to evict unpinned pages at any time. ** ** The cache must not perform any reference counting. A single ** call to xUnpin() unpins the page regardless of the number of prior calls ** to xFetch(). ** ** The xRekey() method is used to change the key value associated with the ** page passed as the second argument. If the cache ** previously contains an entry associated with newKey, it must be ** discarded. ^Any prior cache entry associated with newKey is guaranteed not ** to be pinned. ** ** When SQLite calls the xTruncate() method, the cache must discard all ** existing cache entries with page numbers (keys) greater than or equal ** to the value of the iLimit parameter passed to xTruncate(). If any ** of these pages are pinned, they are implicitly unpinned, meaning that ** they can be safely discarded. ** ** ^The xDestroy() method is used to delete a cache allocated by xCreate(). ** All resources associated with the specified cache should be freed. ^After ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] ** handle invalid, and will not use it with any other sqlite3_pcache_methods |
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