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Overview
Comment:Remove an obsolete optimization in pcache that due to more recent changes was recently making the code a little slower.
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SHA3-256: c4e7e175eecfd79015f4fae99618dfce6baf97c21bf3c909ea535d4e12dcaaad
User & Date: drh 2017-09-01 12:57:33.041
Context
2017-09-01
14:50
Add the new sqlite3PagerUnrefPageOne() pager method to deal with the special case of unreferencing page1. (check-in: b2e2100cf7 user: drh tags: trunk)
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)
Changes
Unified Diff Ignore Whitespace Patch
Changes to src/pcache.c.
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*/
void SQLITE_NOINLINE sqlite3PcacheRelease(PgHdr *p){
  assert( p->nRef>0 );
  p->pCache->nRefSum--;
  if( (--p->nRef)==0 ){
    if( p->flags&PGHDR_CLEAN ){
      pcacheUnpin(p);
    }else if( p->pDirtyPrev!=0 ){ /*OPTIMIZATION-IF-FALSE*/
      /* Move the page to the head of the dirty list. If p->pDirtyPrev==0,
      ** then page p is already at the head of the dirty list and the
      ** following call would be a no-op. Hence the OPTIMIZATION-IF-FALSE
      ** tag above.  */
      pcacheManageDirtyList(p, PCACHE_DIRTYLIST_FRONT);
    }
  }
}

/*
** Increase the reference count of a supplied page by 1.








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*/
void SQLITE_NOINLINE sqlite3PcacheRelease(PgHdr *p){
  assert( p->nRef>0 );
  p->pCache->nRefSum--;
  if( (--p->nRef)==0 ){
    if( p->flags&PGHDR_CLEAN ){
      pcacheUnpin(p);
    }else{




      pcacheManageDirtyList(p, PCACHE_DIRTYLIST_FRONT);
    }
  }
}

/*
** Increase the reference count of a supplied page by 1.
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