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Overview
Comment:Save a few bytes and a few cycles by setting Vdbe.expmask to zero for statements prepared using legacy interface sqlite3_prepare().
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SHA1: a8fd705258643863493476f8b42ee981608a339f
User & Date: dan 2017-02-23 16:30:16.521
References
2017-03-02
13:13
Make sure the Vdbe.expmask value is set correctly in sqlite3VdbeSwap(). This fixes a problem introduced by [a8fd7052]. (check-in: 29f54b899e user: drh tags: trunk)
Context
2017-02-25
17:47
Optimize defragmentPage() in the case where the page contains either one or two free-blocks and a small number of fragmented bytes. (check-in: 4cd2a9672c user: dan tags: trunk)
2017-02-24
19:58
Optimize defragmentPage() in the case where the page contains either one or two free-blocks and a small number of fragmented bytes. (check-in: 202b1c0276 user: dan tags: defragmentpage-opt)
2017-02-23
16:30
Save a few bytes and a few cycles by setting Vdbe.expmask to zero for statements prepared using legacy interface sqlite3_prepare(). (check-in: a8fd705258 user: dan tags: trunk)
2017-02-22
19:41
Move a branch condition in analyze.c inside an #ifdef SQLITE_ENABLE_STAT4 block. (check-in: d6afd98de3 user: dan tags: trunk)
Changes
Side-by-Side Diff Ignore Whitespace Patch
Changes to src/vdbeapi.c.
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  sqlite3_mutex *mutex = ((Vdbe*)pStmt)->db->mutex;
#endif
  sqlite3_mutex_enter(mutex);
  for(i=0; i<p->nVar; i++){
    sqlite3VdbeMemRelease(&p->aVar[i]);
    p->aVar[i].flags = MEM_Null;
  }
  assert( p->isPrepareV2 || p->expmask==0 );
  if( p->isPrepareV2 && p->expmask ){
  if( p->expmask ){
    p->expired = 1;
  }
  sqlite3_mutex_leave(mutex);
  return rc;
}
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  **
  ** IMPLEMENTATION-OF: R-48440-37595 If the specific value bound to host
  ** parameter in the WHERE clause might influence the choice of query plan
  ** for a statement, then the statement will be automatically recompiled,
  ** as if there had been a schema change, on the first sqlite3_step() call
  ** following any change to the bindings of that parameter.
  */
  if( p->isPrepareV2 &&
     ((i<32 && p->expmask & ((u32)1 << i)) || p->expmask==0xffffffff)
  assert( p->isPrepareV2 || p->expmask==0 );
  if( p->expmask & ((u32)1 << (i&0x001F)) && (i<32 || p->expmask==0xffffffff) ){
  ){
    p->expired = 1;
  }
  return SQLITE_OK;
}

/*
** Bind a text or BLOB value.
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*/
int sqlite3_transfer_bindings(sqlite3_stmt *pFromStmt, sqlite3_stmt *pToStmt){
  Vdbe *pFrom = (Vdbe*)pFromStmt;
  Vdbe *pTo = (Vdbe*)pToStmt;
  if( pFrom->nVar!=pTo->nVar ){
    return SQLITE_ERROR;
  }
  assert( pTo->isPrepareV2 || pTo->expmask==0 );
  if( pTo->isPrepareV2 && pTo->expmask ){
  if( pTo->expmask ){
    pTo->expired = 1;
  }
  assert( pFrom->isPrepareV2 || pFrom->expmask==0 );
  if( pFrom->isPrepareV2 && pFrom->expmask ){
  if( pFrom->expmask ){
    pFrom->expired = 1;
  }
  return sqlite3TransferBindings(pFromStmt, pToStmt);
}
#endif

/*
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Changes to src/vdbeaux.c.
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/*
** Remember the SQL string for a prepared statement.
*/
void sqlite3VdbeSetSql(Vdbe *p, const char *z, int n, int isPrepareV2){
  assert( isPrepareV2==1 || isPrepareV2==0 );
  if( p==0 ) return;
  if( !isPrepareV2 ) p->expmask = 0;
#if defined(SQLITE_OMIT_TRACE) && !defined(SQLITE_ENABLE_SQLLOG)
  if( !isPrepareV2 ) return;
#endif
  assert( p->zSql==0 );
  p->zSql = sqlite3DbStrNDup(p->db, z, n);
  p->isPrepareV2 = (u8)isPrepareV2;
}
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