/*
Copyright (C) SYSTAP, LLC DBA Blazegraph 2006-2016. All rights reserved.
Contact:
SYSTAP, LLC DBA Blazegraph
2501 Calvert ST NW #106
Washington, DC 20008
licenses@blazegraph.com
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; version 2 of the License.
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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
* Created on Aug 18, 2008
*/
package com.bigdata.bop.joinGraph;
import com.bigdata.relation.rule.IRule;
import com.bigdata.relation.rule.eval.IJoinNexus;
/**
* A factory for {@link IEvaluationPlan}s that do not reorder the predicates in
* the tail.
*
* @author <a href="mailto:thompsonbry@users.sourceforge.net">Bryan Thompson</a>
* @version $Id$
*/
public class NOPEvaluationPlanFactory implements IEvaluationPlanFactory {
private static final long serialVersionUID = 0L;
public static final transient NOPEvaluationPlanFactory INSTANCE = new NOPEvaluationPlanFactory();
public IEvaluationPlan newPlan(final IJoinNexus joinNexus, final IRule rule) {
final int tailCount = rule.getTailCount();
final int[] order = new int[tailCount];
for(int i=0; i<tailCount; i++) {
order[i] = i;
}
return new IEvaluationPlan() {
public int[] getOrder() {
return order;
}
public boolean isEmpty() {
return false;
}
public long rangeCount(int tailIndex) {
return joinNexus.getRangeCountFactory().rangeCount(
rule.getTail(tailIndex));
}
};
}
}