/*
* Cloud9: A Hadoop toolkit for working with big data
*
* 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.collection.trec;
import java.io.IOException;
import java.net.URI;
import java.util.Arrays;
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.Configuration;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.filecache.DistributedCache;
import org.apache.hadoop.fs.FSDataOutputStream;
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.Counters;
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.output.FileOutputFormat;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;
import org.apache.log4j.Logger;
import edu.umd.cloud9.collection.DocnoMapping;
/**
* Simple demo program that counts all the documents in the TREC collection. Run without any
* arguments for help.
*
* @author Jimmy Lin
*/
public class CountTrecDocuments extends Configured implements Tool {
private static final Logger LOG = Logger.getLogger(CountTrecDocuments.class);
private static enum Count { DOCS };
private static class MyMapper extends Mapper<LongWritable, TrecDocument, Text, IntWritable> {
private static final Text docid = new Text();
private static final IntWritable one = new IntWritable(1);
private DocnoMapping docMapping;
@Override
public void setup(Context context) {
try {
Configuration conf = context.getConfiguration();
Path[] localFiles = DistributedCache.getLocalCacheFiles(conf);
// Instead of hard-coding the actual concrete DocnoMapping class, have the name of the
// class passed in as a property; this makes the mapper more general.
docMapping = (DocnoMapping) Class.forName(conf.get("DocnoMappingClass")).newInstance();
// Simply assume that the mappings file is the only file in the distributed cache.
docMapping.loadMapping(localFiles[0], FileSystem.getLocal(conf));
} catch (Exception e) {
e.printStackTrace();
throw new RuntimeException("Error initializing DocnoMapping!");
}
}
@Override
public void map(LongWritable key, TrecDocument doc, Context context)
throws IOException, InterruptedException {
context.getCounter(Count.DOCS).increment(1);
docid.set(doc.getDocid());
one.set(docMapping.getDocno(doc.getDocid()));
context.write(docid, one);
}
}
/**
* Creates an instance of this tool.
*/
public CountTrecDocuments() {}
public static final String COLLECTION_OPTION = "collection";
public static final String OUTPUT_OPTION = "output";
public static final String MAPPING_OPTION = "docnoMapping";
public static final String COUNT_OPTION = "countOutput";
/**
* Runs this tool.
*/
@SuppressWarnings("static-access")
public int run(String[] args) throws Exception {
Options options = new Options();
options.addOption(OptionBuilder.withArgName("path").hasArg()
.withDescription("(required) collection path").create(COLLECTION_OPTION));
options.addOption(OptionBuilder.withArgName("path").hasArg()
.withDescription("(required) output path").create(OUTPUT_OPTION));
options.addOption(OptionBuilder.withArgName("path").hasArg()
.withDescription("(required) DocnoMapping data").create(MAPPING_OPTION));
options.addOption(OptionBuilder.withArgName("path").hasArg()
.withDescription("(optional) output file to write the number of records").create(COUNT_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(COLLECTION_OPTION) || !cmdline.hasOption(OUTPUT_OPTION) ||
!cmdline.hasOption(MAPPING_OPTION)) {
HelpFormatter formatter = new HelpFormatter();
formatter.printHelp(this.getClass().getName(), options);
ToolRunner.printGenericCommandUsage(System.out);
return -1;
}
String inputPath = cmdline.getOptionValue(COLLECTION_OPTION);
String outputPath = cmdline.getOptionValue(OUTPUT_OPTION);
String mappingFile = cmdline.getOptionValue(MAPPING_OPTION);
LOG.info("Tool: " + CountTrecDocuments.class.getSimpleName());
LOG.info(" - input: " + inputPath);
LOG.info(" - output dir: " + outputPath);
LOG.info(" - docno mapping file: " + mappingFile);
Job job = new Job(getConf(), CountTrecDocuments.class.getSimpleName());
job.setJarByClass(CountTrecDocuments.class);
job.setNumReduceTasks(0);
// Pass in the class name as a String; this is makes the mapper general in being able to load
// any collection of Indexable objects that has docid/docno mapping specified by a DocnoMapping
// object.
job.getConfiguration().set("DocnoMappingClass", TrecDocnoMapping.class.getCanonicalName());
// Put the mapping file in the distributed cache so each map worker will have it.
DistributedCache.addCacheFile(new URI(mappingFile), job.getConfiguration());
FileInputFormat.setInputPaths(job, new Path(inputPath));
FileOutputFormat.setOutputPath(job, new Path(outputPath));
FileOutputFormat.setCompressOutput(job, false);
job.setInputFormatClass(TrecDocumentInputFormat.class);
job.setOutputKeyClass(Text.class);
job.setOutputValueClass(IntWritable.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);
Counters counters = job.getCounters();
int numDocs = (int) counters.findCounter(Count.DOCS).getValue();
LOG.info("Read " + numDocs + " docs.");
if (cmdline.hasOption(COUNT_OPTION)) {
String f = cmdline.getOptionValue(COUNT_OPTION);
FileSystem fs = FileSystem.get(getConf());
FSDataOutputStream out = fs.create(new Path(f));
out.write(new Integer(numDocs).toString().getBytes());
out.close();
}
return numDocs;
}
/**
* Dispatches command-line arguments to the tool via the {@code ToolRunner}.
*/
public static void main(String[] args) throws Exception {
LOG.info("Running " + CountTrecDocuments.class.getCanonicalName() +
" with args " + Arrays.toString(args));
ToolRunner.run(new CountTrecDocuments(), args);
}
}