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Overview
Comment:Remove two lines of unnecessary code, for a very small performance increase and size decrease.
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SHA3-256: 15824ccda0f110794a479b58fbf36082d8c383f34bae9dc0921d96547fb37869
User & Date: drh 2018-12-03 01:58:02.016
Context
2018-12-03
14:58
Update the autoconf makefile for MSVC. (check-in: 675aba1f8b user: mistachkin tags: trunk)
01:58
Remove two lines of unnecessary code, for a very small performance increase and size decrease. (check-in: 15824ccda0 user: drh tags: trunk)
01:47
Fix a parser bug in the use of parentheses around table-valued functions. (check-in: 58a51123d1 user: drh tags: trunk)
Changes
Unified Diff Ignore Whitespace Patch
Changes to src/pcache1.c.
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  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)








>








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  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)
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  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;
}










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>








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  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;
}
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  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;








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  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;
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  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;








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  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;
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