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Overview
Comment: | Small size and performance improvement in pcacheManageDirtyList() by not zeroing the PgHdr.pDirtyNext and PgHdr.pDirtyPrev pointers for PgHdr objects that are not on the dirty list. |
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Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA3-256: |
919863b14859d958d6c078097faae020 |
User & Date: | drh 2017-09-01 12:18:41.125 |
Context
2017-09-01
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12:57 | Remove an obsolete optimization in pcache that due to more recent changes was recently making the code a little slower. (check-in: c4e7e175ee user: drh tags: trunk) | |
12:18 | Small size and performance improvement in pcacheManageDirtyList() by not zeroing the PgHdr.pDirtyNext and PgHdr.pDirtyPrev pointers for PgHdr objects that are not on the dirty list. (check-in: 919863b148 user: drh tags: trunk) | |
2017-08-31
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21:11 | Clarify the documentation about "protected" versus "unprotected" sqlite3_value objects. No changes to code. (check-in: 4094a3410e user: drh tags: trunk) | |
Changes
Changes to src/pcache.c.
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187 188 189 190 191 192 193 | p->pDirty = pPage->pDirtyNext; assert( p->bPurgeable || p->eCreate==2 ); if( p->pDirty==0 ){ /*OPTIMIZATION-IF-TRUE*/ assert( p->bPurgeable==0 || p->eCreate==1 ); p->eCreate = 2; } } | < < | < | 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 | p->pDirty = pPage->pDirtyNext; assert( p->bPurgeable || p->eCreate==2 ); if( p->pDirty==0 ){ /*OPTIMIZATION-IF-TRUE*/ assert( p->bPurgeable==0 || p->eCreate==1 ); p->eCreate = 2; } } } if( addRemove & PCACHE_DIRTYLIST_ADD ){ pPage->pDirtyPrev = 0; pPage->pDirtyNext = p->pDirty; if( pPage->pDirtyNext ){ assert( pPage->pDirtyNext->pDirtyPrev==0 ); pPage->pDirtyNext->pDirtyPrev = pPage; }else{ p->pDirtyTail = pPage; if( p->bPurgeable ){ |
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Changes to src/pcache.h.
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39 40 41 42 43 44 45 46 47 48 49 50 51 52 | ** Elements above, except pCache, are public. All that follow are ** private to pcache.c and should not be accessed by other modules. ** pCache is grouped with the public elements for efficiency. */ i16 nRef; /* Number of users of this page */ PgHdr *pDirtyNext; /* Next element in list of dirty pages */ PgHdr *pDirtyPrev; /* Previous element in list of dirty pages */ }; /* 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 | > > | 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 | ** Elements above, except pCache, are public. All that follow are ** private to pcache.c and should not be accessed by other modules. ** pCache is grouped with the public elements for efficiency. */ i16 nRef; /* Number of users of this page */ PgHdr *pDirtyNext; /* Next element in list of dirty pages */ PgHdr *pDirtyPrev; /* Previous element in list of dirty pages */ /* NB: pDirtyNext and pDirtyPrev are undefined if the ** PgHdr object is not dirty */ }; /* 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 |
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