| /* |
| * 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.rewriter.rules; |
| |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| 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.algebra.base.IOptimizationContext; |
| import edu.uci.ics.hyracks.algebricks.core.algebra.base.LogicalOperatorTag; |
| import edu.uci.ics.hyracks.algebricks.core.algebra.base.LogicalVariable; |
| import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.ConstantExpression; |
| import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.AbstractBinaryJoinOperator; |
| import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.AbstractLogicalOperator; |
| import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.visitors.VariableUtilities; |
| import edu.uci.ics.hyracks.algebricks.core.rewriter.base.IAlgebraicRewriteRule; |
| |
| public class PushAssignDownThroughProductRule implements IAlgebraicRewriteRule { |
| |
| @Override |
| public boolean rewritePre(Mutable<ILogicalOperator> opRef, IOptimizationContext context) throws AlgebricksException { |
| return false; |
| } |
| |
| @Override |
| public boolean rewritePost(Mutable<ILogicalOperator> opRef, IOptimizationContext context) |
| throws AlgebricksException { |
| AbstractLogicalOperator op1 = (AbstractLogicalOperator) opRef.getValue(); |
| if (op1.getOperatorTag() != LogicalOperatorTag.ASSIGN) { |
| return false; |
| } |
| Mutable<ILogicalOperator> op2Ref = op1.getInputs().get(0); |
| AbstractLogicalOperator op2 = (AbstractLogicalOperator) op2Ref.getValue(); |
| if (op2.getOperatorTag() != LogicalOperatorTag.INNERJOIN) { |
| return false; |
| } |
| AbstractBinaryJoinOperator join = (AbstractBinaryJoinOperator) op2; |
| if (join.getCondition().getValue() != ConstantExpression.TRUE) { |
| return false; |
| } |
| |
| List<LogicalVariable> used = new ArrayList<LogicalVariable>(); |
| VariableUtilities.getUsedVariables(op1, used); |
| |
| Mutable<ILogicalOperator> b0Ref = op2.getInputs().get(0); |
| ILogicalOperator b0 = b0Ref.getValue(); |
| List<LogicalVariable> b0Scm = new ArrayList<LogicalVariable>(); |
| VariableUtilities.getLiveVariables(b0, b0Scm); |
| if (b0Scm.containsAll(used)) { |
| // push assign on left branch |
| op2Ref.setValue(b0); |
| b0Ref.setValue(op1); |
| opRef.setValue(op2); |
| return true; |
| } else { |
| Mutable<ILogicalOperator> b1Ref = op2.getInputs().get(1); |
| ILogicalOperator b1 = b1Ref.getValue(); |
| List<LogicalVariable> b1Scm = new ArrayList<LogicalVariable>(); |
| VariableUtilities.getLiveVariables(b1, b1Scm); |
| if (b1Scm.containsAll(used)) { |
| // push assign on right branch |
| op2Ref.setValue(b1); |
| b1Ref.setValue(op1); |
| opRef.setValue(op2); |
| return true; |
| } else { |
| return false; |
| } |
| } |
| } |
| |
| } |