/*
* 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 java.util.ArrayList;
import java.util.List;
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.input.FileSplit;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;
import org.chombo.util.SecondarySort;
import org.chombo.util.Tuple;
import org.chombo.util.Utility;
/**
* Aggregates item predicted rating and attribute aggregator. Used by attribute bases diversifier
* @author pranab
*
*/
public class ItemRatingAttributeAggregator extends Configured implements Tool{
@Override
public int run(String[] args) throws Exception {
Job job = new Job(getConf());
String jobName = "Item predicted rating and attribute aggregator MR";
job.setJobName(jobName);
job.setJarByClass(ItemRatingAttributeAggregator.class);
FileInputFormat.addInputPaths(job, args[0]);
FileOutputFormat.setOutputPath(job, new Path(args[1]));
job.setMapperClass(ItemRatingAttributeAggregator.ItemAggregatorMapper.class);
job.setReducerClass(ItemRatingAttributeAggregator.ItemAggregatorReducer.class);
job.setMapOutputKeyClass(Tuple.class);
job.setMapOutputValueClass(Tuple.class);
job.setOutputKeyClass(NullWritable.class);
job.setOutputValueClass(Text.class);
job.setGroupingComparatorClass(SecondarySort.TuplePairGroupComprator.class);
job.setPartitionerClass(SecondarySort.TuplePairPartitioner.class);
Utility.setConfiguration(job.getConfiguration());
int numReducer = job.getConfiguration().getInt("iraa.num.reducer", -1);
numReducer = -1 == numReducer ? job.getConfiguration().getInt("num.reducer", 1) : numReducer;
job.setNumReduceTasks(numReducer);
int status = job.waitForCompletion(true) ? 0 : 1;
return status;
}
/**
* @author pranab
*
*/
public static class ItemAggregatorMapper extends Mapper<LongWritable, Text, Tuple, Tuple> {
private String fieldDelimRegex;
private Tuple keyOut = new Tuple();
private Tuple valOut = new Tuple();
private boolean isMetaDataFileSplit;
private String itemID;
private int[] attrOrdinals;
/* (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", ",");
String metaDataFilePrefix = config.get("iraa.item.metadta.file.prefix", "meta");
isMetaDataFileSplit = ((FileSplit)context.getInputSplit()).getPath().getName().startsWith(metaDataFilePrefix);
if (null != config.get("iraa.item.attr.ordinals")) {
attrOrdinals = Utility.intArrayFromString(config.get("iraa.item.attr.ordinals"));
}
}
/* (non-Javadoc)
* @see org.apache.hadoop.mapreduce.Mapper#map(KEYIN, VALUEIN, org.apache.hadoop.mapreduce.Mapper.Context)
*/
@Override
protected void map(LongWritable key, Text value, Context context)
throws IOException, InterruptedException {
String[] items = value.toString().split(fieldDelimRegex);
keyOut.initialize();
valOut.initialize();
if (isMetaDataFileSplit) {
//items attributes
itemID = items[0];
keyOut.add(itemID, 1);
valOut.append(1);
if (null != attrOrdinals) {
//selected attributes
for (int ordinal : attrOrdinals) {
valOut.append(items[ordinal]);
}
} else {
//all attributes
for (int i = 1; i < items.length; ++i) {
valOut.append(items[i]);
}
}
} else {
//predicted rating
itemID = items[1];
keyOut.add(itemID, 0);
valOut.add(0,items[0], items[2]);
}
context.write(keyOut, valOut);
}
}
/**
* @author pranab
*
*/
public static class ItemAggregatorReducer extends Reducer<Tuple, Tuple, NullWritable, Text> {
private String fieldDelim;
private Text valOut = new Text();
private List<String> users = new ArrayList<String>();
private List<Integer> ratings = new ArrayList<Integer>();
private String itemID;
private StringBuilder stBld = new StringBuilder();
private boolean outputRating;
/* (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();
fieldDelim = config.get("field.delim", ",");
outputRating = config.getBoolean("iraa.output.rating", false);
}
/* (non-Javadoc)
* @see org.apache.hadoop.mapreduce.Reducer#reduce(KEYIN, java.lang.Iterable, org.apache.hadoop.mapreduce.Reducer.Context)
*/
protected void reduce(Tuple key, Iterable<Tuple> values, Context context)
throws IOException, InterruptedException {
users.clear();
if (outputRating) {
ratings.clear();
}
itemID = key.getString(0);
for(Tuple value : values) {
int type = value.getInt(0);
if (0 == type) {
//users for which this item has predicted ratings
users.add(value.getString(1));
if (outputRating) {
ratings.add(value.getInt(2));
}
} else {
//item attributes
String attrs = value.toString(1);
int i = 0;
for (String user : users) {
stBld.delete(0, stBld.length());
stBld.append(user).append(fieldDelim).append(itemID).append(fieldDelim).append(attrs);
if (outputRating) {
stBld.append(fieldDelim).append(ratings.get(i++));
}
valOut.set(stBld.toString());
//userID, itemID, item attribute, ...,..,[rating]
context.write(NullWritable.get(), valOut);
}
}
}
}
}
/**
* @param args
* @throws Exception
*/
public static void main(String[] args) throws Exception {
int exitCode = ToolRunner.run(new ItemRatingAttributeAggregator(), args);
System.exit(exitCode);
}
}