/*
* Sifarish: Recommendation Engine
* Author: Pranab Ghosh
*
* 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.
*/
package org.sifarish.common;
import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;
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.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.Tool;
import org.apache.hadoop.util.ToolRunner;
import org.chombo.util.TextTuple;
import org.chombo.util.Utility;
/**
* Converts a correlation in exploded form to a sparse matrix form which is item ID followed by
* a list of ( itemID, correlation) tuples
* @author pranab
*
*/
public class CorrelationMatrixBuilder extends Configured implements Tool {
@Override
public int run(String[] args) throws Exception {
Job job = new Job(getConf());
String jobName = "Correlation natrix builder MR";
job.setJobName(jobName);
job.setJarByClass(CorrelationMatrixBuilder.class);
FileInputFormat.addInputPath(job, new Path(args[0]));
FileOutputFormat.setOutputPath(job, new Path(args[1]));
Utility.setConfiguration(job.getConfiguration());
job.setMapperClass(CorrelationMatrixBuilder.MatrixBuilderMapper.class);
job.setReducerClass(CorrelationMatrixBuilder.MatrixBuilderReducer.class);
job.setMapOutputKeyClass(Text.class);
job.setMapOutputValueClass(TextTuple.class);
int numReducer = job.getConfiguration().getInt("cmb.num.reducer", -1);
numReducer = -1 == numReducer ? job.getConfiguration().getInt("num.reducer", 1) : numReducer;
job.setNumReduceTasks(numReducer);
job.setOutputKeyClass(NullWritable.class);
job.setOutputValueClass(Text.class);
int status = job.waitForCompletion(true) ? 0 : 1;
return status;
}
/**
* @author pranab
*
*/
public static class MatrixBuilderMapper extends Mapper<LongWritable, Text, Text, TextTuple> {
private String fieldDelimRegex;
private String subFieldDelim;
private Text outKey = new Text();
private TextTuple outVal = new TextTuple();
/* (non-Javadoc)
* @see org.apache.hadoop.mapreduce.Mapper#setup(org.apache.hadoop.mapreduce.Mapper.Context)
*/
protected void setup(Context context) throws IOException, InterruptedException {
Configuration config = context.getConfiguration();
fieldDelimRegex = config.get("field.delim.regex", ",");
subFieldDelim = config.get("sub.field.delim", ":");
outVal.setFieldDelim(subFieldDelim);
}
/* (non-Javadoc)
* @see org.apache.hadoop.mapreduce.Mapper#map(KEYIN, VALUEIN, org.apache.hadoop.mapreduce.Mapper.Context)
*/
protected void map(LongWritable key, Text value, Context context)
throws IOException, InterruptedException {
String[] items = value.toString().split(fieldDelimRegex);
//emit for both items
outKey.set(items[0]);
outVal.add(items[1], items[2]);
context.write(outKey, outVal);
outKey.set(items[1]);
outVal.add(items[0], items[2]);
context.write(outKey, outVal);
}
}
/**
* @author pranab
*
*/
public static class MatrixBuilderReducer extends Reducer<Text, TextTuple, NullWritable, Text> {
private String fieldDelimOut;
private StringBuilder stBld = new StringBuilder();;
private Text outVal = new Text();
/* (non-Javadoc)
* @see org.apache.hadoop.mapreduce.Reducer#setup(org.apache.hadoop.mapreduce.Reducer.Context)
*/
protected void setup(Context context) throws IOException, InterruptedException {
Configuration config = context.getConfiguration();
fieldDelimOut = config.get("field.delim.out", ",");
}
/* (non-Javadoc)
* @see org.apache.hadoop.mapreduce.Reducer#reduce(KEYIN, java.lang.Iterable, org.apache.hadoop.mapreduce.Reducer.Context)
*/
protected void reduce(Text key, Iterable<TextTuple> values, Context context)
throws IOException, InterruptedException {
stBld.delete(0, stBld.length());
stBld.append(key.toString());
for (TextTuple value : values){
stBld.append(fieldDelimOut).append(value.toString());
}
outVal.set(stBld.toString());
context.write(NullWritable.get(), outVal);
}
}
/**
* @param args
*/
public static void main(String[] args) throws Exception {
int exitCode = ToolRunner.run(new CorrelationMatrixBuilder(), args);
System.exit(exitCode);
}
}