/**
 * 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.tez.plan;

import java.util.Iterator;
import java.util.Set;

import org.apache.pig.impl.plan.DependencyOrderWalker;
import org.apache.pig.impl.plan.VisitorException;

import com.google.common.collect.Sets;

public class TezPlanContainerUDFCollector extends TezPlanContainerVisitor {
    private Set<String> udfs = Sets.newHashSet();

    /**
     * @param ps PrintStream to output plan information to
     * @param plan tez plan to print
     */
    public TezPlanContainerUDFCollector(TezPlanContainer planContainer) {
        super(planContainer, new DependencyOrderWalker<TezPlanContainerNode, TezPlanContainer>(planContainer));
    }

    @Override
    public void visitTezPlanContainerNode(TezPlanContainerNode tezPlanContainerNode) throws VisitorException {
        Iterator<TezOperator> it = tezPlanContainerNode.getTezOperPlan().iterator();
        while (it.hasNext()) {
            udfs.addAll(it.next().UDFs);
        }
    }

    public Set<String> getUdfs() {
        return udfs;
    }
}