| /* |
| * Copyright 2009-2013 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.hivesterix.optimizer.rules; |
| |
| import java.util.ArrayList; |
| import java.util.HashSet; |
| import java.util.List; |
| import java.util.Set; |
| |
| import org.apache.commons.lang3.mutable.Mutable; |
| import org.apache.commons.lang3.mutable.MutableObject; |
| |
| 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.ProjectOperator; |
| import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.visitors.VariableUtilities; |
| import edu.uci.ics.hyracks.algebricks.core.rewriter.base.IAlgebraicRewriteRule; |
| |
| public class IntroduceEarlyProjectRule 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 op = (AbstractLogicalOperator) opRef.getValue(); |
| if (op.getOperatorTag() != LogicalOperatorTag.PROJECT) { |
| return false; |
| } |
| AbstractLogicalOperator middleOp = (AbstractLogicalOperator) op.getInputs().get(0).getValue(); |
| List<LogicalVariable> deliveredVars = new ArrayList<LogicalVariable>(); |
| List<LogicalVariable> usedVars = new ArrayList<LogicalVariable>(); |
| List<LogicalVariable> producedVars = new ArrayList<LogicalVariable>(); |
| |
| VariableUtilities.getUsedVariables(op, deliveredVars); |
| VariableUtilities.getUsedVariables(middleOp, usedVars); |
| VariableUtilities.getProducedVariables(middleOp, producedVars); |
| |
| Set<LogicalVariable> requiredVariables = new HashSet<LogicalVariable>(); |
| requiredVariables.addAll(deliveredVars); |
| requiredVariables.addAll(usedVars); |
| requiredVariables.removeAll(producedVars); |
| |
| if (middleOp.getInputs().size() <= 0 || middleOp.getInputs().size() > 1) |
| return false; |
| |
| AbstractLogicalOperator targetOp = (AbstractLogicalOperator) middleOp.getInputs().get(0).getValue(); |
| if (targetOp.getOperatorTag() != LogicalOperatorTag.DATASOURCESCAN) |
| return false; |
| |
| Set<LogicalVariable> deliveredEarlyVars = new HashSet<LogicalVariable>(); |
| VariableUtilities.getLiveVariables(targetOp, deliveredEarlyVars); |
| |
| deliveredEarlyVars.removeAll(requiredVariables); |
| if (deliveredEarlyVars.size() > 0) { |
| ArrayList<LogicalVariable> requiredVars = new ArrayList<LogicalVariable>(); |
| requiredVars.addAll(requiredVariables); |
| ILogicalOperator earlyProjectOp = new ProjectOperator(requiredVars); |
| Mutable<ILogicalOperator> earlyProjectOpRef = new MutableObject<ILogicalOperator>(earlyProjectOp); |
| Mutable<ILogicalOperator> targetRef = middleOp.getInputs().get(0); |
| middleOp.getInputs().set(0, earlyProjectOpRef); |
| earlyProjectOp.getInputs().add(targetRef); |
| context.computeAndSetTypeEnvironmentForOperator(earlyProjectOp); |
| return true; |
| } |
| return false; |
| } |
| } |