Authset.java Source code

Introduction

Here is the source code for Authset.java

Source

/**
 * 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.examples;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.HashSet;
import java.util.StringTokenizer;
import java.util.zip.GZIPInputStream;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.filecache.DistributedCache;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.Reducer;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.util.GenericOptionsParser;

public class Authset {

    public static class TokenizerMapper extends Mapper<Object, Text, IntWritable, IntWritable> {

        HashSet<Integer> partial_hubs;
        IntWritable mkey = new IntWritable();
        IntWritable one = new IntWritable(1);

        protected void setup(Context context) throws IOException {
            partial_hubs = new HashSet<Integer>();
            /*
            Path[] files = DistributedCache.getLocalCacheFiles(context
                 .getConfiguration());
                
            if (files == null || files.length == 0) {
              throw new RuntimeException(
                    "User information is not set in DistributedCache");
            }
            */
            // Read all files in the DistributedCache
            //for (Path p : files) {
            BufferedReader rdr = new BufferedReader(
                    new InputStreamReader(new FileInputStream(new File("partial_hubs.txt"))));
            String line;
            // For each record in the user file
            while ((line = rdr.readLine()) != null) {

                // Get the user ID for this record

                Integer node = Integer.parseInt(line.trim());
                partial_hubs.add(node);
            }
            //}

        }

        public void map(Object key, Text value, Context context) throws IOException, InterruptedException {
            StringTokenizer itr = new StringTokenizer(value.toString());
            Integer node = Integer.parseInt(itr.nextToken());
            if (partial_hubs.contains(node)) {
                while (itr.hasMoreTokens()) {
                    mkey.set(Integer.parseInt(itr.nextToken()));
                    context.write(mkey, one);
                }
            }

        }
    }

    public static class IntSumReducer extends Reducer<IntWritable, IntWritable, IntWritable, NullWritable> {
        private IntWritable result = new IntWritable();
        private int min_threshold = 1500;

        public void reduce(IntWritable key, Iterable<IntWritable> values, Context context)
                throws IOException, InterruptedException {
            int count = 0;
            for (IntWritable i : values)
                count++;
            if (count >= min_threshold)
                context.write(key, NullWritable.get());

        }

    }

    public static void main(String[] args) throws Exception {
        Configuration conf = new Configuration();
        String[] otherArgs = new GenericOptionsParser(conf, args).getRemainingArgs();
        if (otherArgs.length < 2) {
            System.err.println("Usage: wordcount <in> [<in>...] <out>");
            System.exit(2);
        }
        Job job = new Job(conf, "word count");
        job.setJarByClass(Authset.class);
        job.setMapperClass(TokenizerMapper.class);
        //job.setCombinerClass(IntSumReducer.class);
        job.setReducerClass(IntSumReducer.class);
        job.setOutputKeyClass(IntWritable.class);
        job.setOutputValueClass(NullWritable.class);
        job.setMapOutputKeyClass(IntWritable.class);
        job.setMapOutputValueClass(IntWritable.class);
        job.setNumReduceTasks(10);
        for (int i = 0; i < otherArgs.length - 1; ++i) {
            FileInputFormat.addInputPath(job, new Path(otherArgs[i]));
        }
        FileOutputFormat.setOutputPath(job, new Path(otherArgs[otherArgs.length - 1]));
        //DistributedCache.addCacheFile(new Path(otherArgs[0]).toUri(),
        //job.getConfiguration());

        //DistributedCache.setLocalFiles(job.getConfiguration(), otherArgs[0]);
        System.exit(job.waitForCompletion(true) ? 0 : 1);
    }
}