| /* |
| * Copyright 2009-2010 by The Regents of the University of California |
| * 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 from |
| * |
| * 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 edu.uci.ics.pregelix.example.utils; |
| |
| import java.io.IOException; |
| import java.util.Iterator; |
| |
| import org.apache.hadoop.fs.Path; |
| import org.apache.hadoop.io.LongWritable; |
| import org.apache.hadoop.io.NullWritable; |
| import org.apache.hadoop.io.Text; |
| import org.apache.hadoop.mapred.FileInputFormat; |
| import org.apache.hadoop.mapred.FileOutputFormat; |
| import org.apache.hadoop.mapred.JobClient; |
| 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.Reducer; |
| import org.apache.hadoop.mapred.Reporter; |
| import org.apache.hadoop.mapred.TextInputFormat; |
| |
| @SuppressWarnings("deprecation") |
| public class VertexAggregator { |
| |
| public static class MapRecordOnly extends MapReduceBase implements |
| Mapper<LongWritable, Text, NullWritable, LongWritable> { |
| private final NullWritable nullValue = NullWritable.get(); |
| private final LongWritable count = new LongWritable(1); |
| |
| public void map(LongWritable id, Text inputValue, OutputCollector<NullWritable, LongWritable> output, |
| Reporter reporter) throws IOException { |
| output.collect(nullValue, count); |
| } |
| } |
| |
| public static class CombineRecordOnly extends MapReduceBase implements |
| Reducer<NullWritable, LongWritable, NullWritable, LongWritable> { |
| private final NullWritable nullValue = NullWritable.get(); |
| |
| public void reduce(NullWritable inputKey, Iterator<LongWritable> inputValue, |
| OutputCollector<NullWritable, LongWritable> output, Reporter reporter) throws IOException { |
| long count = 0; |
| while (inputValue.hasNext()) |
| count += inputValue.next().get(); |
| output.collect(nullValue, new LongWritable(count)); |
| } |
| } |
| |
| public static class ReduceRecordOnly extends MapReduceBase implements |
| Reducer<NullWritable, LongWritable, NullWritable, Text> { |
| private final NullWritable nullValue = NullWritable.get(); |
| |
| public void reduce(NullWritable inputKey, Iterator<LongWritable> inputValue, |
| OutputCollector<NullWritable, Text> output, Reporter reporter) throws IOException { |
| long count = 0; |
| while (inputValue.hasNext()) |
| count += inputValue.next().get(); |
| output.collect(nullValue, new Text(Long.toString(count))); |
| } |
| } |
| |
| public static void main(String[] args) throws IOException { |
| JobConf job = new JobConf(VertexAggregator.class); |
| |
| job.setJobName(VertexAggregator.class.getSimpleName()); |
| job.setMapperClass(MapRecordOnly.class); |
| job.setCombinerClass(CombineRecordOnly.class); |
| job.setReducerClass(ReduceRecordOnly.class); |
| job.setMapOutputKeyClass(NullWritable.class); |
| job.setMapOutputValueClass(LongWritable.class); |
| |
| job.setInputFormat(TextInputFormat.class); |
| FileInputFormat.setInputPaths(job, args[0]); |
| FileOutputFormat.setOutputPath(job, new Path(args[1])); |
| job.setNumReduceTasks(Integer.parseInt(args[2])); |
| JobClient.runJob(job); |
| } |
| } |