/**
 * (C) Copyright IBM Corp. 2010, 2015
 *
 * 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 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 com.ibm.bi.dml.runtime.matrix.mapred;

import java.io.IOException;
import java.util.Iterator;

import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.OutputCollector;
import org.apache.hadoop.mapred.Reducer;
import org.apache.hadoop.mapred.Reporter;

import com.ibm.bi.dml.runtime.matrix.data.MatrixValue;
import com.ibm.bi.dml.runtime.matrix.data.TaggedFirstSecondIndexes;


public class MMCJMRCombiner extends MMCJMRCombinerReducerBase 
implements Reducer<TaggedFirstSecondIndexes, MatrixValue, TaggedFirstSecondIndexes, MatrixValue>
{

	public void reduce(TaggedFirstSecondIndexes indexes, Iterator<MatrixValue> values,
			OutputCollector<TaggedFirstSecondIndexes, MatrixValue> out,
			Reporter report) throws IOException {
	
		//perform aggregate
		MatrixValue aggregateValue=performAggregateInstructions(indexes, values);
		
		if(aggregateValue!=null)
			out.collect(indexes, aggregateValue);
		
	}
	
	public void configure(JobConf job)
	{
		super.configure(job);
	}
}