NonSortTestMR.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.hadoop.mapred.nativetask.nonsorttest;

import java.io.ByteArrayOutputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.util.Arrays;
import java.util.StringTokenizer;

import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.Reducer;

public class NonSortTestMR {

  public static class Map extends Mapper<Object, Text, Text, IntWritable> {
    private final static IntWritable one = new IntWritable(1);
    private final Text word = new Text();

    @Override
    public void map(Object key, Text value, Context context)
      throws IOException, InterruptedException {
      final String line = value.toString();
      final StringTokenizer tokenizer = new StringTokenizer(line);
      while (tokenizer.hasMoreTokens()) {
        word.set(tokenizer.nextToken());
        context.write(word, one);
      }
    }
  }

  public static class KeyHashSumReduce extends Reducer<Text, IntWritable, Text, LongWritable> {
    long sum = 0;
    ByteArrayOutputStream os = new ByteArrayOutputStream();
    DataOutputStream dos = new DataOutputStream(os);

    @Override
    public void reduce(Text key, Iterable<IntWritable> values, Context context) throws IOException,
    InterruptedException {
      for (final IntWritable val : values) {
        os.reset();
        key.write(dos);
        final int hash = Arrays.hashCode(os.toByteArray());
        sum += hash;
      }
    }

    @Override
    public void cleanup(Context context) throws IOException, InterruptedException {
      context.write(new Text("NonSortTest"), new LongWritable(sum));
    }
  }

}