PartitionMapper.java Source code

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Here is the source code for PartitionMapper.java

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/*
 * Copyright 2012-14 Justin A. Debrabant <debrabant@cs.brown.edu> and Matteo Riondato <matteo@cs.brown.edu>
 *
 * 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.
 *
 */

import java.io.IOException;
import java.util.ArrayList;
import java.util.Hashtable;
import java.util.Random;

import org.apache.hadoop.filecache.DistributedCache;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.ArrayWritable;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.IOUtils;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.MapFile;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.io.Writable;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.MapReduceBase;
import org.apache.hadoop.mapred.Mapper;
import org.apache.hadoop.mapred.OutputCollector;
import org.apache.hadoop.mapred.Reporter;
import org.apache.hadoop.util.ReflectionUtils;

public class PartitionMapper extends MapReduceBase implements Mapper<LongWritable, Text, IntWritable, Text> {
    private int reducersNum;

    @Override
    public void configure(JobConf conf) {
        reducersNum = conf.getInt("PARMM.reducersNum", 64);
    }

    @Override
    public void map(LongWritable lineNum, Text value, OutputCollector<IntWritable, Text> output, Reporter reporter)
            throws IOException {
        Random rand = new Random();

        int key = rand.nextInt(reducersNum);
        output.collect(new IntWritable(key), value);
    }
}