spork-master/src/org/apache/pig/backend/hadoop/executionengine/mapReduceLayer/plans/ScalarPhyFinder.java
/*
 * 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.mapReduceLayer.plans;

import java.util.ArrayList;
import java.util.List;

import org.apache.pig.backend.hadoop.executionengine.physicalLayer.PhysicalOperator;
import org.apache.pig.backend.hadoop.executionengine.physicalLayer.expressionOperators.POUserFunc;
import org.apache.pig.backend.hadoop.executionengine.physicalLayer.plans.PhyPlanVisitor;
import org.apache.pig.backend.hadoop.executionengine.physicalLayer.plans.PhysicalPlan;
import org.apache.pig.impl.plan.DepthFirstWalker;
import org.apache.pig.impl.plan.VisitorException;

public class ScalarPhyFinder extends PhyPlanVisitor {

    List<PhysicalOperator> scalars = new ArrayList<PhysicalOperator>();
    
    public ScalarPhyFinder(PhysicalPlan plan) {
        super(plan, new DepthFirstWalker<PhysicalOperator, PhysicalPlan>(plan));
    }

    public List<PhysicalOperator> getScalars() {
        return scalars;
    }

    @Override
    public void visitUserFunc(POUserFunc userFunc) throws VisitorException {
        if(userFunc.getReferencedOperator() != null) {
            scalars.add(userFunc.getReferencedOperator());
        }
    }
}
