HadoopUpdateStreamSerializer.java

package ldbc.snb.datagen.hadoop;

import ldbc.snb.datagen.serializer.PersonSerializer;
import ldbc.snb.datagen.serializer.UpdateEventSerializer;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Reducer;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.input.SequenceFileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.mapreduce.lib.output.SequenceFileOutputFormat;

import java.io.IOException;
import java.io.OutputStream;
import java.util.zip.GZIPOutputStream;

/**
 * Created by aprat on 10/15/14.
 */
public class HadoopUpdateStreamSerializer {
	
	public static class HadoopUpdateStreamSerializerReducer  extends Reducer<LongWritable, Text, LongWritable, Text> {
		
		private int reducerId;                          /** The id of the reducer.**/
		private PersonSerializer personSerializer_;   /** The person serializer **/
		private UpdateEventSerializer updateSerializer_;   
		private OutputStream out;
		
		protected void setup(Context context) {
			Configuration conf = context.getConfiguration();
			int reducerId = Integer.parseInt(conf.get("reducerId"));
			int partitionId = Integer.parseInt(conf.get("partitionId"));
			String streamType = conf.get("streamType");
			try {
				FileSystem fs = FileSystem.get(conf);
				if( Boolean.parseBoolean(conf.get("ldbc.snb.datagen.serializer.compressed")) == true ) {
					Path outFile = new Path(context.getConfiguration().get("ldbc.snb.datagen.serializer.socialNetworkDir")+"/updateStream_"+reducerId+"_"+partitionId+"_"+streamType+".csv.gz");
					out = new GZIPOutputStream( fs.create(outFile));
				} else {
					Path outFile = new Path(context.getConfiguration().get("ldbc.snb.datagen.serializer.socialNetworkDir")+"/updateStream_"+reducerId+"_"+partitionId+"_"+streamType+".csv");
					out = fs.create(outFile);
                }
			} catch( Exception e ) {
				System.err.println(e.getMessage());
				e.printStackTrace();
			}
		}
		
		@Override
		public void reduce(LongWritable key, Iterable<Text> valueSet,Context context)
			throws IOException, InterruptedException {
			for( Text t : valueSet ) {
				out.write(t.toString().getBytes("UTF8"));
			}
			
		}
		protected void cleanup(Context context){
			try {
				out.close();
			} catch( Exception e ) {
				System.err.println(e.getMessage());
			}
		}
	}
	
	
	private Configuration conf;
	
	public HadoopUpdateStreamSerializer( Configuration conf ) {
		this.conf = new Configuration(conf);
	}
	
	public void run( String inputFileName, int reducer, int partition, String type ) throws Exception {
		
		conf.setInt("reducerId", reducer);
		conf.setInt("partitionId", partition);
		conf.set("streamType", type);
		
		Job job = Job.getInstance(conf, "Update Stream Serializer");
		job.setMapOutputKeyClass(LongWritable.class);
		job.setMapOutputValueClass(Text.class);
		job.setOutputKeyClass(LongWritable.class);
		job.setOutputValueClass(Text.class);
        job.setJarByClass(HadoopUpdateStreamSerializerReducer.class);
		job.setReducerClass(HadoopUpdateStreamSerializerReducer.class);
		job.setNumReduceTasks(1);
		job.setInputFormatClass(SequenceFileInputFormat.class);
		job.setOutputFormatClass(SequenceFileOutputFormat.class);
		
		FileInputFormat.setInputPaths(job, new Path(inputFileName));
		FileOutputFormat.setOutputPath(job, new Path(conf.get("ldbc.snb.datagen.serializer.hadoopDir")+"/aux"));
		if(!job.waitForCompletion(true)) {
            throw new Exception();
        }
		
		
		try{
			FileSystem fs = FileSystem.get(conf);
			fs.delete(new Path(conf.get("ldbc.snb.datagen.serializer.hadoopDir")+"/aux"),true);
		} catch(IOException e) {
			System.err.println(e.getMessage());
		}
	}
}