/ Check-in [15824ccd]
Login

Many hyperlinks are disabled.
Use anonymous login to enable hyperlinks.

Overview
Comment:Remove two lines of unnecessary code, for a very small performance increase and size decrease.
Downloads: Tarball | ZIP archive | SQL archive
Timelines: family | ancestors | descendants | both | trunk
Files: files | file ages | folders
SHA3-256:15824ccda0f110794a479b58fbf36082d8c383f34bae9dc0921d96547fb37869
User & Date: drh 2018-12-03 01:58:02
Context
2018-12-03
14:58
Update the autoconf makefile for MSVC. check-in: 675aba1f user: mistachkin tags: trunk
01:58
Remove two lines of unnecessary code, for a very small performance increase and size decrease. check-in: 15824ccd user: drh tags: trunk
01:47
Fix a parser bug in the use of parentheses around table-valued functions. check-in: 58a51123 user: drh tags: trunk
Changes
Hide Diffs Unified Diffs Ignore Whitespace Patch

Changes to src/pcache1.c.

98
99
100
101
102
103
104

105
106
107
108
109
110
111
...
566
567
568
569
570
571
572
573

574
575
576
577
578
579
580
...
904
905
906
907
908
909
910
911
912

913
914
915
916
917
918
919
....
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
  unsigned int iKey;             /* Key value (page number) */
  u8 isBulkLocal;                /* This page from bulk local storage */
  u8 isAnchor;                   /* This is the PGroup.lru element */
  PgHdr1 *pNext;                 /* Next in hash table chain */
  PCache1 *pCache;               /* Cache that currently owns this page */
  PgHdr1 *pLruNext;              /* Next in LRU list of unpinned pages */
  PgHdr1 *pLruPrev;              /* Previous in LRU list of unpinned pages */

};

/*
** A page is pinned if it is not on the LRU list.  To be "pinned" means
** that the page is in active use and must not be deallocated.
*/
#define PAGE_IS_PINNED(p)    ((p)->pLruNext==0)
................................................................................
  assert( PAGE_IS_UNPINNED(pPage) );
  assert( pPage->pLruNext );
  assert( pPage->pLruPrev );
  assert( sqlite3_mutex_held(pPage->pCache->pGroup->mutex) );
  pPage->pLruPrev->pLruNext = pPage->pLruNext;
  pPage->pLruNext->pLruPrev = pPage->pLruPrev;
  pPage->pLruNext = 0;
  pPage->pLruPrev = 0;

  assert( pPage->isAnchor==0 );
  assert( pPage->pCache->pGroup->lru.isAnchor==1 );
  pPage->pCache->nRecyclable--;
  return pPage;
}


................................................................................

  if( pPage ){
    unsigned int h = iKey % pCache->nHash;
    pCache->nPage++;
    pPage->iKey = iKey;
    pPage->pNext = pCache->apHash[h];
    pPage->pCache = pCache;
    pPage->pLruPrev = 0;
    pPage->pLruNext = 0;

    *(void **)pPage->page.pExtra = 0;
    pCache->apHash[h] = pPage;
    if( iKey>pCache->iMaxKey ){
      pCache->iMaxKey = iKey;
    }
  }
  return pPage;
................................................................................
 
  assert( pPage->pCache==pCache );
  pcache1EnterMutex(pGroup);

  /* It is an error to call this function if the page is already 
  ** part of the PGroup LRU list.
  */
  assert( pPage->pLruPrev==0 && pPage->pLruNext==0 );
  assert( PAGE_IS_PINNED(pPage) );

  if( reuseUnlikely || pGroup->nPurgeable>pGroup->nMaxPage ){
    pcache1RemoveFromHash(pPage, 1);
  }else{
    /* Add the page to the PGroup LRU list. */
    PgHdr1 **ppFirst = &pGroup->lru.pLruNext;







>







 







|
>







 







|
|
>







 







|







98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
...
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
...
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
....
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
  unsigned int iKey;             /* Key value (page number) */
  u8 isBulkLocal;                /* This page from bulk local storage */
  u8 isAnchor;                   /* This is the PGroup.lru element */
  PgHdr1 *pNext;                 /* Next in hash table chain */
  PCache1 *pCache;               /* Cache that currently owns this page */
  PgHdr1 *pLruNext;              /* Next in LRU list of unpinned pages */
  PgHdr1 *pLruPrev;              /* Previous in LRU list of unpinned pages */
                                 /* NB: pLruPrev is only valid if pLruNext!=0 */
};

/*
** A page is pinned if it is not on the LRU list.  To be "pinned" means
** that the page is in active use and must not be deallocated.
*/
#define PAGE_IS_PINNED(p)    ((p)->pLruNext==0)
................................................................................
  assert( PAGE_IS_UNPINNED(pPage) );
  assert( pPage->pLruNext );
  assert( pPage->pLruPrev );
  assert( sqlite3_mutex_held(pPage->pCache->pGroup->mutex) );
  pPage->pLruPrev->pLruNext = pPage->pLruNext;
  pPage->pLruNext->pLruPrev = pPage->pLruPrev;
  pPage->pLruNext = 0;
  /* pPage->pLruPrev = 0;
  ** No need to clear pLruPrev as it is never accessed if pLruNext is 0 */
  assert( pPage->isAnchor==0 );
  assert( pPage->pCache->pGroup->lru.isAnchor==1 );
  pPage->pCache->nRecyclable--;
  return pPage;
}


................................................................................

  if( pPage ){
    unsigned int h = iKey % pCache->nHash;
    pCache->nPage++;
    pPage->iKey = iKey;
    pPage->pNext = pCache->apHash[h];
    pPage->pCache = pCache;
    pPage->pLruNext = 0;
    /* pPage->pLruPrev = 0;
    ** No need to clear pLruPrev since it is not accessed when pLruNext==0 */
    *(void **)pPage->page.pExtra = 0;
    pCache->apHash[h] = pPage;
    if( iKey>pCache->iMaxKey ){
      pCache->iMaxKey = iKey;
    }
  }
  return pPage;
................................................................................
 
  assert( pPage->pCache==pCache );
  pcache1EnterMutex(pGroup);

  /* It is an error to call this function if the page is already 
  ** part of the PGroup LRU list.
  */
  assert( pPage->pLruNext==0 );
  assert( PAGE_IS_PINNED(pPage) );

  if( reuseUnlikely || pGroup->nPurgeable>pGroup->nMaxPage ){
    pcache1RemoveFromHash(pPage, 1);
  }else{
    /* Add the page to the PGroup LRU list. */
    PgHdr1 **ppFirst = &pGroup->lru.pLruNext;