| /* |
| * 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.HashSet; |
| 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.operators.logical.AbstractLogicalOperator; |
| import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.AssignOperator; |
| import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.visitors.VariableUtilities; |
| import edu.uci.ics.hyracks.algebricks.core.rewriter.base.IAlgebraicRewriteRule; |
| |
| public class ConsolidateAssignsRule implements IAlgebraicRewriteRule { |
| |
| @Override |
| public boolean rewritePre(Mutable<ILogicalOperator> opRef, IOptimizationContext context) { |
| return false; |
| } |
| |
| @Override |
| public boolean rewritePost(Mutable<ILogicalOperator> opRef, IOptimizationContext context) |
| throws AlgebricksException { |
| AbstractLogicalOperator op = (AbstractLogicalOperator) opRef.getValue(); |
| if (op.getOperatorTag() != LogicalOperatorTag.ASSIGN) { |
| return false; |
| } |
| AssignOperator assign1 = (AssignOperator) op; |
| |
| AbstractLogicalOperator op2 = (AbstractLogicalOperator) assign1.getInputs().get(0).getValue(); |
| if (op2.getOperatorTag() != LogicalOperatorTag.ASSIGN) { |
| return false; |
| } |
| AssignOperator assign2 = (AssignOperator) op2; |
| |
| HashSet<LogicalVariable> used1 = new HashSet<LogicalVariable>(); |
| VariableUtilities.getUsedVariables(assign1, used1); |
| for (LogicalVariable v2 : assign2.getVariables()) { |
| if (used1.contains(v2)) { |
| return false; |
| } |
| } |
| |
| assign1.getVariables().addAll(assign2.getVariables()); |
| assign1.getExpressions().addAll(assign2.getExpressions()); |
| |
| Mutable<ILogicalOperator> botOpRef = assign2.getInputs().get(0); |
| List<Mutable<ILogicalOperator>> asgnInpList = assign1.getInputs(); |
| asgnInpList.clear(); |
| asgnInpList.add(botOpRef); |
| context.computeAndSetTypeEnvironmentForOperator(assign1); |
| return true; |
| } |
| |
| } |