SQLite: Check-in [6e0298cd]

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Overview

Comment:	This change is not correct for the boundary case of nCellKey==0. Was: Small performance gain and size reduction in sqlite3VdbeIdxKeyCompare().
Downloads:	Tarball \| ZIP archive \| SQL archive
Timelines:	family \| ancestors \| mistake
Files:	files \| file ages \| folders
SHA1:	6e0298cdcb3b900fedac0eebdc7cfd69a763a44b
User & Date:	drh 2015-09-02 12:52:05
Original Comment:	Small performance gain and size reduction in sqlite3VdbeIdxKeyCompare().

Context

2015-09-02
12:52		This change is not correct for the boundary case of nCellKey==0. Was: Small performance gain and size reduction in sqlite3VdbeIdxKeyCompare(). (Closed-Leaf check-in: 6e0298cd user: drh tags: mistake)
2015-09-01
23:51		Very minor optimizations in the unix VFS. (check-in: 6db3ff45 user: drh tags: trunk)

Changes

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Changes to src/vdbeaux.c.

  int rc;
  BtCursor *pCur = pC->pCursor;
  Mem m;

  assert( sqlite3BtreeCursorIsValid(pCur) );
  VVA_ONLY(rc =) sqlite3BtreeKeySize(pCur, &nCellKey);
  assert( rc==SQLITE_OK );    /* pCur is always valid so KeySize cannot fail */
  /* nCellKey will always be between 0 and 0xffffffff because of the way
  ** that btreeParseCellPtr() and sqlite3GetVarint32() are implemented */
  if( nCellKey<=0 || nCellKey>0x7fffffff ){
    *res = 0;
    return SQLITE_CORRUPT_BKPT;
  }

  sqlite3VdbeMemInit(&m, db, 0);
  rc = sqlite3VdbeMemFromBtree(pC->pCursor, 0, (u32)nCellKey, 1, &m);
  if( rc ){
    return rc;
  }
  *res = sqlite3VdbeRecordCompare(m.n, m.z, pUnpacked);
  sqlite3VdbeMemRelease(&m);








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  int rc;
  BtCursor *pCur = pC->pCursor;
  Mem m;

  assert( sqlite3BtreeCursorIsValid(pCur) );
  VVA_ONLY(rc =) sqlite3BtreeKeySize(pCur, &nCellKey);
  assert( rc==SQLITE_OK );    /* pCur is always valid so KeySize cannot fail */
  /* nCellKey will always be between 0 and 0x7fffffff because of the way
  ** that btreeParseCellPtr() and sqlite3GetVarint32() are implemented */
  if( (nCellKey & ~(i64)0x7fffffff)!=0 ){
    *res = 0;
    return SQLITE_CORRUPT_BKPT;
  }
  assert( nCellKey>=0 && nCellKey<=0x7fffffff );
  sqlite3VdbeMemInit(&m, db, 0);
  rc = sqlite3VdbeMemFromBtree(pC->pCursor, 0, (u32)nCellKey, 1, &m);
  if( rc ){
    return rc;
  }
  *res = sqlite3VdbeRecordCompare(m.n, m.z, pUnpacked);
  sqlite3VdbeMemRelease(&m);