SQLite

/*
** 2003 April 6
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains code used to implement the PRAGMA command.
**
** $Id: pragma.c,v 1.62 2004/09/02 15:14:01 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

#if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)
# include "pager.h"
# include "btree.h"

  db->temp_store = ts;
  return SQLITE_OK;
}

/*
** Generate code to return a single integer value.
*/
static void returnSingleInt(Parse *pParse, const char *zLabel, int value){
  Vdbe *v = sqlite3GetVdbe(pParse);
  sqlite3VdbeAddOp(v, OP_Integer, value, 0);
  if( pParse->explain==0 ){
    sqlite3VdbeSetNumCols(v, 1);
    sqlite3VdbeSetColName(v, 0, zLabel, P3_STATIC);
  }
  sqlite3VdbeAddOp(v, OP_Callback, 1, 0);
}

/*
** Check to see if zRight and zLeft refer to a pragma that queries
** or changes one of the flags in db->flags.  Return 1 if so and 0 if not.
** Also, implement the pragma.

  for(i=0; i<sizeof(aPragma)/sizeof(aPragma[0]); i++){
    if( sqlite3StrICmp(zLeft, aPragma[i].zName)==0 ){
      sqlite *db = pParse->db;
      Vdbe *v;
      if( zRight==0 ){
        v = sqlite3GetVdbe(pParse);
        if( v ){
          returnSingleInt(pParse,
               aPragma[i].zName, (db->flags&aPragma[i].mask)!=0);
        }
      }else if( getBoolean(zRight) ){
        db->flags |= aPragma[i].mask;
      }else{
        db->flags &= ~aPragma[i].mask;
      }
      return 1;

  ** database page size value.  The value can only be set if
  ** the database has not yet been created.
  */
  if( sqlite3StrICmp(zLeft,"page_size")==0 ){
    Btree *pBt = pDb->pBt;
    if( !zRight ){
      int size = pBt ? sqlite3BtreeGetPageSize(pBt) : 0;
      returnSingleInt(pParse, "page_size", size);
    }else{
      sqlite3BtreeSetPageSize(pBt, atoi(zRight), 0);
    }
  }else

  /*
  **  PRAGMA [database.]cache_size

  ** cache size stored on the disk so the cache size will revert
  ** to its default value when the database is closed and reopened.
  ** N should be a positive integer.
  */
  if( sqlite3StrICmp(zLeft,"cache_size")==0 ){
    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
    if( !zRight ){
      returnSingleInt(pParse, "cache_size", pDb->cache_size);
    }else{
      int size = atoi(zRight);
      if( size<0 ) size = -size;
      pDb->cache_size = size;
      sqlite3BtreeSetCacheSize(pDb->pBt, pDb->cache_size);
    }
  }else

  ** value will be restored the next time the database is opened.
  **
  ** Note that it is possible for the library compile-time options to
  ** override this setting
  */
  if( sqlite3StrICmp(zLeft, "temp_store")==0 ){
    if( !zRight ){
      returnSingleInt(pParse, "temp_store", db->temp_store);
    }else{
      changeTempStorage(pParse, zRight);
    }
  }else

  /*
  **   PRAGMA [database.]synchronous
  **   PRAGMA [database.]synchronous=OFF|ON|NORMAL|FULL
  **
  ** Return or set the local value of the synchronous flag.  Changing
  ** the local value does not make changes to the disk file and the
  ** default value will be restored the next time the database is
  ** opened.
  */
  if( sqlite3StrICmp(zLeft,"synchronous")==0 ){
    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
    if( !zRight ){
      returnSingleInt(pParse, "synchronous", pDb->safety_level-1);
    }else{
      if( !db->autoCommit ){
        sqlite3ErrorMsg(pParse, 
            "Safety level may not be changed inside a transaction");
      }else{
        pDb->safety_level = getSafetyLevel(zRight)+1;
        sqlite3BtreeSetSafetyLevel(pDb->pBt, pDb->safety_level);

# 2004 September 2
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.
# This file implements tests for the page_size PRAGMA.
#
# $Id: pagesize.test,v 1.1 2004/09/02 15:14:01 drh Exp $


set testdir [file dirname $argv0]
source $testdir/tester.tcl

do_test pagesize-1.1 {
  execsql {PRAGMA page_size}
} 1024
do_test pagesize-1.2 {
  catch {execsql {EXPLAIN PRAGMA page_size}}
} 0
do_test pagesize-1.3 {
  execsql {
    CREATE TABLE t1(a);
    PRAGMA page_size=2048;
    PRAGMA page_size;
  }
} 1024
do_test pagesize-1.4 {
  db close
  file delete -force test.db
  sqlite3 db test.db
  execsql {
    PRAGMA page_size=2048;
    CREATE TABLE t1(a);
    PRAGMA page_size;
  }
} 2048
do_test pagesize-1.5 {
  db close
  sqlite3 db test.db
  execsql {
    PRAGMA page_size
  }
} 2048
do_test pagesize-1.6 {
  file size test.db
} 2048



finish_test