| /* |
| * 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.Iterator; |
| |
| 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.ILogicalPlan; |
| 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.operators.logical.AbstractLogicalOperator; |
| import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.InnerJoinOperator; |
| import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.LeftOuterJoinOperator; |
| import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.SubplanOperator; |
| import edu.uci.ics.hyracks.algebricks.core.algebra.util.OperatorPropertiesUtil; |
| import edu.uci.ics.hyracks.algebricks.core.rewriter.base.IAlgebraicRewriteRule; |
| |
| public class InsertOuterJoinRule 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 op0 = (AbstractLogicalOperator) opRef.getValue(); |
| if (op0.getOperatorTag() != LogicalOperatorTag.SUBPLAN) { |
| return false; |
| } |
| SubplanOperator subplan = (SubplanOperator) op0; |
| |
| Iterator<ILogicalPlan> plansIter = subplan.getNestedPlans().iterator(); |
| ILogicalPlan p = null; |
| while (plansIter.hasNext()) { |
| p = plansIter.next(); |
| } |
| if (p == null) { |
| return false; |
| } |
| if (p.getRoots().size() != 1) { |
| return false; |
| } |
| Mutable<ILogicalOperator> subplanRoot = p.getRoots().get(0); |
| AbstractLogicalOperator op1 = (AbstractLogicalOperator) subplanRoot.getValue(); |
| Mutable<ILogicalOperator> opUnder = subplan.getInputs().get(0); |
| |
| if (OperatorPropertiesUtil.isNullTest((AbstractLogicalOperator) opUnder.getValue())) { |
| return false; |
| } |
| |
| switch (op1.getOperatorTag()) { |
| case INNERJOIN: { |
| InnerJoinOperator join = (InnerJoinOperator) op1; |
| Mutable<ILogicalOperator> leftRef = join.getInputs().get(0); |
| Mutable<ILogicalOperator> rightRef = join.getInputs().get(1); |
| Mutable<ILogicalOperator> ntsRef = getNtsAtEndOfPipeline(leftRef); |
| if (ntsRef == null) { |
| ntsRef = getNtsAtEndOfPipeline(rightRef); |
| if (ntsRef == null) { |
| return false; |
| } else { |
| Mutable<ILogicalOperator> t = leftRef; |
| leftRef = rightRef; |
| rightRef = t; |
| } |
| } |
| ntsRef.setValue(opUnder.getValue()); |
| LeftOuterJoinOperator loj = new LeftOuterJoinOperator(join.getCondition()); |
| loj.getInputs().add(leftRef); |
| loj.getInputs().add(rightRef); |
| opRef.setValue(loj); |
| context.computeAndSetTypeEnvironmentForOperator(loj); |
| return true; |
| } |
| case LEFTOUTERJOIN: { |
| LeftOuterJoinOperator join = (LeftOuterJoinOperator) op1; |
| Mutable<ILogicalOperator> leftRef = join.getInputs().get(0); |
| Mutable<ILogicalOperator> ntsRef = getNtsAtEndOfPipeline(leftRef); |
| if (ntsRef == null) { |
| return false; |
| } |
| ntsRef.setValue(opUnder.getValue()); |
| opRef.setValue(join); |
| context.computeAndSetTypeEnvironmentForOperator(join); |
| return true; |
| } |
| default: { |
| return false; |
| } |
| } |
| } |
| |
| private Mutable<ILogicalOperator> getNtsAtEndOfPipeline(Mutable<ILogicalOperator> opRef) { |
| AbstractLogicalOperator op = (AbstractLogicalOperator) opRef.getValue(); |
| if (op.getOperatorTag() == LogicalOperatorTag.NESTEDTUPLESOURCE) { |
| return opRef; |
| } |
| if (op.getInputs().size() != 1) { |
| return null; |
| } |
| return getNtsAtEndOfPipeline(op.getInputs().get(0)); |
| } |
| |
| } |