/*
* Cloud9: A MapReduce Library for Hadoop
*
* 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 edu.umd.cloud9.example.bfs;
import java.io.IOException;
import org.apache.commons.cli.CommandLine;
import org.apache.commons.cli.CommandLineParser;
import org.apache.commons.cli.GnuParser;
import org.apache.commons.cli.HelpFormatter;
import org.apache.commons.cli.OptionBuilder;
import org.apache.commons.cli.Options;
import org.apache.commons.cli.ParseException;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.input.TextInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.mapreduce.lib.output.SequenceFileOutputFormat;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;
import org.apache.log4j.Logger;
import edu.umd.cloud9.io.array.ArrayListOfIntsWritable;
/**
* Tool for taking a plain-text encoding of a directed graph and building corresponding Hadoop
* structures for running parallel breadth-first search.
*
* @author Jimmy Lin
*/
public class EncodeBfsGraph extends Configured implements Tool {
private static final Logger LOG = Logger.getLogger(EncodeBfsGraph.class);
private static enum Graph {
Nodes, Edges
};
private static class MyMapper extends Mapper<LongWritable, Text, IntWritable, BfsNode> {
private static final IntWritable nid = new IntWritable();
private static final BfsNode node = new BfsNode();
private static int src;
@Override
public void setup(Context context) {
src = context.getConfiguration().getInt(SRC_OPTION, 0);
node.setType(BfsNode.Type.Complete);
}
@Override
public void map(LongWritable key, Text t, Context context) throws IOException,
InterruptedException {
String[] arr = t.toString().trim().split("\\s+");
int cur = Integer.parseInt(arr[0]);
nid.set(cur);
node.setNodeId(cur);
node.setDistance(cur == src ? 0 : Integer.MAX_VALUE);
if (arr.length == 1) {
node.setAdjacencyList(new ArrayListOfIntsWritable());
} else {
int[] neighbors = new int[arr.length - 1];
for (int i = 1; i < arr.length; i++) {
neighbors[i - 1] = Integer.parseInt(arr[i]);
}
node.setAdjacencyList(new ArrayListOfIntsWritable(neighbors));
}
context.getCounter(Graph.Nodes).increment(1);
context.getCounter(Graph.Edges).increment(arr.length - 1);
context.write(nid, node);
}
}
public EncodeBfsGraph() {
}
private static final String INPUT_OPTION = "input";
private static final String OUTPUT_OPTION = "output";
private static final String SRC_OPTION = "src";
@SuppressWarnings("static-access")
@Override
public int run(String[] args) throws Exception {
Options options = new Options();
options.addOption(OptionBuilder.withArgName("path")
.hasArg().withDescription("XML dump file").create(INPUT_OPTION));
options.addOption(OptionBuilder.withArgName("path")
.hasArg().withDescription("output path").create(OUTPUT_OPTION));
options.addOption(OptionBuilder.withArgName("nodeid")
.hasArg().withDescription("source node").create(SRC_OPTION));
CommandLine cmdline;
CommandLineParser parser = new GnuParser();
try {
cmdline = parser.parse(options, args);
} catch (ParseException exp) {
System.err.println("Error parsing command line: " + exp.getMessage());
return -1;
}
if (!cmdline.hasOption(INPUT_OPTION) || !cmdline.hasOption(OUTPUT_OPTION)
|| !cmdline.hasOption(SRC_OPTION)) {
HelpFormatter formatter = new HelpFormatter();
formatter.printHelp(this.getClass().getName(), options);
ToolRunner.printGenericCommandUsage(System.out);
return -1;
}
String inputPath = cmdline.getOptionValue(INPUT_OPTION);
String outputPath = cmdline.getOptionValue(OUTPUT_OPTION);
int src = Integer.parseInt(cmdline.getOptionValue(SRC_OPTION));
LOG.info("Tool name: " + this.getClass().getName());
LOG.info(" - inputDir: " + inputPath);
LOG.info(" - outputDir: " + outputPath);
LOG.info(" - src: " + src);
Job job = Job.getInstance(getConf());
job.setJobName(String.format("EncodeBfsGraph[%s: %s, %s: %s, %s: %d]",
INPUT_OPTION, inputPath, OUTPUT_OPTION, outputPath, SRC_OPTION, src));
job.setJarByClass(EncodeBfsGraph.class);
job.setNumReduceTasks(0);
job.getConfiguration().setInt(SRC_OPTION, src);
job.getConfiguration().setInt("mapred.min.split.size", 1024 * 1024 * 1024);
FileInputFormat.addInputPath(job, new Path(inputPath));
FileOutputFormat.setOutputPath(job, new Path(outputPath));
job.setInputFormatClass(TextInputFormat.class);
job.setOutputFormatClass(SequenceFileOutputFormat.class);
job.setMapOutputKeyClass(IntWritable.class);
job.setMapOutputValueClass(BfsNode.class);
job.setOutputKeyClass(IntWritable.class);
job.setOutputValueClass(BfsNode.class);
job.setMapperClass(MyMapper.class);
// Delete the output directory if it exists already.
FileSystem.get(job.getConfiguration()).delete(new Path(outputPath), true);
job.waitForCompletion(true);
return 0;
}
/**
* Dispatches command-line arguments to the tool via the <code>ToolRunner</code>.
*/
public static void main(String[] args) throws Exception {
int res = ToolRunner.run(new EncodeBfsGraph(), args);
System.exit(res);
}
}