| /* |
| * Copyright 2009-2010 by The Regents of the University of California |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * you may obtain a copy of the License from |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package edu.uci.ics.hyracks.algebricks.compiler.rewriter.rulecontrollers; |
| |
| import java.util.Collection; |
| |
| import org.apache.commons.lang3.mutable.Mutable; |
| |
| import edu.uci.ics.hyracks.algebricks.common.exceptions.AlgebricksException; |
| import edu.uci.ics.hyracks.algebricks.core.algebra.base.ILogicalOperator; |
| import edu.uci.ics.hyracks.algebricks.core.rewriter.base.AbstractRuleController; |
| import edu.uci.ics.hyracks.algebricks.core.rewriter.base.IAlgebraicRewriteRule; |
| |
| /** |
| * |
| * Runs each rule until it produces no changes. Then the whole collection of |
| * rules is run again until no change is made. |
| * |
| * |
| * @author Nicola |
| * |
| */ |
| |
| public class PrioritizedRuleController extends AbstractRuleController { |
| |
| public PrioritizedRuleController() { |
| super(); |
| } |
| |
| @Override |
| public boolean rewriteWithRuleCollection(Mutable<ILogicalOperator> root, Collection<IAlgebraicRewriteRule> rules) |
| throws AlgebricksException { |
| boolean anyRuleFired = false; |
| boolean anyChange = false; |
| do { |
| anyChange = false; |
| for (IAlgebraicRewriteRule r : rules) { |
| while (true) { |
| boolean ruleFired = rewriteOperatorRef(root, r); |
| if (ruleFired) { |
| anyChange = true; |
| anyRuleFired = true; |
| } else { |
| break; // go to next rule |
| } |
| } |
| } |
| } while (anyChange); |
| return anyRuleFired; |
| } |
| } |