com.intel.hadoop.graphbuilder.idnormalize.mapreduce.SortDictMapper.java Source code

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Here is the source code for com.intel.hadoop.graphbuilder.idnormalize.mapreduce.SortDictMapper.java

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/* Copyright (C) 2012 Intel Corporation.
 *     All rights reserved.
 *           
 *  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.
 *
 * For more about this software visit:
 *      http://www.01.org/GraphBuilder 
 */
package com.intel.hadoop.graphbuilder.idnormalize.mapreduce;

import java.io.IOException;
import java.util.NoSuchElementException;
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.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.log4j.Logger;

import com.intel.hadoop.graphbuilder.parser.FieldParser;

/**
 * Mapper function for SortDictMR job 
 * 
 */

public class SortDictMapper extends MapReduceBase implements Mapper<LongWritable, Text, IntWritable, Text> {

    private static final Logger LOG = Logger.getLogger(SortDictMapper.class);

    @Override
    public void configure(JobConf job) {
        super.configure(job);
        this.hashRawVid = job.getBoolean("hashRawVid", true);
        this.numChunks = job.getInt("numChunks", 256);
        try {
            this.vidparser = (FieldParser) Class.forName(job.get("VidParser")).newInstance();
        } catch (InstantiationException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void map(LongWritable key, Text val, OutputCollector<IntWritable, Text> out, Reporter reporter)
            throws IOException {
        String line = val.toString();
        StringTokenizer tokenizer = new StringTokenizer(line);

        try {
            String vid = tokenizer.nextToken();
            if (hashRawVid) { // partition by old vid
                Object rawId = vidparser.getValue(tokenizer.nextToken());
                int hash = rawId.hashCode() % numChunks;
                if (hash < 0)
                    hash += numChunks; // resolving negative hashcode
                out.collect(new IntWritable(hash), val);
            } else { // partition by new vid
                int hash = Long.valueOf(vid).hashCode() % numChunks;
                out.collect(new IntWritable(hash), val);
            }
        } catch (NoSuchElementException e) {
            e.printStackTrace();
            LOG.error("Error parsing vertex dictionary: " + val.toString());
        }

    }

    private FieldParser vidparser;
    private int numChunks;
    private boolean hashRawVid;
}