| /* |
| * 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.pig.backend.hadoop.executionengine.physicalLayer.expressionOperators; |
| |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| import org.apache.pig.impl.plan.OperatorKey; |
| import org.apache.pig.backend.hadoop.executionengine.physicalLayer.plans.PhyPlanVisitor; |
| import org.apache.pig.backend.hadoop.executionengine.physicalLayer.plans.PhysicalPlan; |
| import org.apache.pig.backend.hadoop.executionengine.physicalLayer.expressionOperators.ExpressionOperator; |
| import org.apache.pig.impl.plan.VisitorException; |
| |
| public abstract class UnaryExpressionOperator extends ExpressionOperator { |
| |
| ExpressionOperator expr; |
| private transient List<ExpressionOperator> child; |
| |
| public UnaryExpressionOperator(OperatorKey k, int rp) { |
| super(k, rp); |
| |
| } |
| |
| public UnaryExpressionOperator(OperatorKey k) { |
| super(k); |
| |
| } |
| |
| @Override |
| public boolean supportsMultipleInputs() { |
| // TODO Auto-generated method stub |
| return false; |
| } |
| |
| /** |
| * Set the contained expression to the be the input value. |
| */ |
| public void setInputAsExpr(PhysicalPlan plan) { |
| expr = (ExpressionOperator)plan.getPredecessors(this).get(0); |
| } |
| |
| /** |
| * Set the contained expression explicitly. This is mostly for testing. |
| * @param e Expression to contain. |
| */ |
| public void setExpr(ExpressionOperator e) { |
| expr = e; |
| } |
| |
| /** |
| * Get the contained expression. |
| * @return contained expression. |
| */ |
| public ExpressionOperator getExpr() { |
| return expr; |
| } |
| |
| protected void cloneHelper(UnaryExpressionOperator op) { |
| // Don't clone this, as it is just a reference to something already in |
| // the plan. |
| expr = op.expr; |
| resultType = op.getResultType(); |
| } |
| |
| /** |
| * Get child expression of this expression |
| */ |
| @Override |
| public List<ExpressionOperator> getChildExpressions() { |
| if (child == null) { |
| child = new ArrayList<ExpressionOperator>(); |
| child.add(expr); |
| } |
| |
| return child; |
| } |
| |
| } |