| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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 at |
| * |
| * 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 org.apache.hyracks.algebricks.rewriter.rules; |
| |
| import org.apache.commons.lang3.mutable.Mutable; |
| |
| import org.apache.hyracks.algebricks.common.exceptions.AlgebricksException; |
| import org.apache.hyracks.algebricks.core.algebra.base.ILogicalOperator; |
| import org.apache.hyracks.algebricks.core.algebra.base.IOptimizationContext; |
| import org.apache.hyracks.algebricks.core.algebra.base.LogicalOperatorTag; |
| import org.apache.hyracks.algebricks.core.algebra.operators.logical.AbstractLogicalOperator; |
| import org.apache.hyracks.algebricks.core.algebra.operators.logical.DataSourceScanOperator; |
| import org.apache.hyracks.algebricks.core.algebra.operators.logical.ProjectOperator; |
| import org.apache.hyracks.algebricks.core.rewriter.base.IAlgebraicRewriteRule; |
| |
| public class PushProjectIntoDataSourceScanRule 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.getInputs().size() <= 0) |
| return false; |
| AbstractLogicalOperator project = (AbstractLogicalOperator) op.getInputs().get(0).getValue(); |
| if (project.getOperatorTag() != LogicalOperatorTag.PROJECT) |
| return false; |
| AbstractLogicalOperator exchange = (AbstractLogicalOperator) project.getInputs().get(0).getValue(); |
| if (exchange.getOperatorTag() != LogicalOperatorTag.EXCHANGE) |
| return false; |
| AbstractLogicalOperator inputOp = (AbstractLogicalOperator) exchange.getInputs().get(0).getValue(); |
| if (inputOp.getOperatorTag() != LogicalOperatorTag.DATASOURCESCAN) |
| return false; |
| DataSourceScanOperator scanOp = (DataSourceScanOperator) inputOp; |
| ProjectOperator projectOp = (ProjectOperator) project; |
| scanOp.addProjectVariables(projectOp.getVariables()); |
| if (op.getOperatorTag() != LogicalOperatorTag.EXCHANGE) { |
| op.getInputs().set(0, project.getInputs().get(0)); |
| } else { |
| op.getInputs().set(0, exchange.getInputs().get(0)); |
| } |
| return true; |
| } |
| } |