/*
* Lokomo OneCMDB - An Open Source Software for Configuration
* Management of Datacenter Resources
*
* Copyright (C) 2006 Lokomo Systems AB
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or (at
* your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301 USA.
*
* Lokomo Systems AB can be contacted via e-mail: info@lokomo.com or via
* paper mail: Lokomo Systems AB, Sv�rdv�gen 27, SE-182 33
* Danderyd, Sweden.
*
*/
package org.onecmdb.core.internal.storage.engine;
import java.util.ArrayList;
import java.util.List;
import org.onecmdb.core.IDataSourceReader;
import org.onecmdb.core.IExpression;
public class QueryEngine implements IDataSourceReader {
public static final int PAGE_SIZE = 10;
private static boolean useCmdbSessionCache = true;
private List<IDataSourceReader> readers;
public List evaluate(IExpression expr) {
List result = new ArrayList();
for (IDataSourceReader reader : getDataSourceReaders()) {
List objects = reader.evaluate(expr);
// TODO: handle paging.
result.addAll(objects);
}
return(result);
}
public Object evaluateToUnique(IExpression expr) {
for (IDataSourceReader reader : getDataSourceReaders()) {
Object o = reader.evaluateToUnique(expr);
if (o != null) {
return(o);
}
}
return(null);
}
public long evaluateTotalCount(IExpression expr) {
long count = 0;
for (IDataSourceReader reader : getDataSourceReaders()) {
count += reader.evaluateTotalCount(expr);
}
return(count);
}
private List<IDataSourceReader> getDataSourceReaders() {
return(this.readers);
}
public void setDataSourceReaders(List<IDataSourceReader> readers) {
this.readers = readers;
}
}