ac.keio.sslab.nlp.lda.RowIdJob.java Source code

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Here is the source code for ac.keio.sslab.nlp.lda.RowIdJob.java

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/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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
 * <p/>
 * http://www.apache.org/licenses/LICENSE-2.0
 * <p/>
 * 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 ac.keio.sslab.nlp.lda;

import java.util.List;
import java.util.Map;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.SequenceFile;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.util.ToolRunner;
import org.apache.mahout.common.AbstractJob;
import org.apache.mahout.common.Pair;
import org.apache.mahout.common.iterator.sequencefile.PathFilters;
import org.apache.mahout.common.iterator.sequencefile.PathType;
import org.apache.mahout.common.iterator.sequencefile.SequenceFileDirIterable;
import org.apache.mahout.math.VectorWritable;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Converts a vector representation of documents into a {@code document x terms} matrix.
 * The input data is in {@code SequenceFile<Text,VectorWritable>} format (as generated by
 * {@link org.apache.mahout.vectorizer.SparseVectorsFromSequenceFiles SparseVectorsFromSequenceFiles}
 * or by {@link org.apache.mahout.vectorizer.EncodedVectorsFromSequenceFiles EncodedVectorsFromSequenceFiles})
 * and generates the following two files as output:
 * <ul><li>A file called "matrix" of format {@code SequenceFile<IntWritable,VectorWritable>}.</li>
 * <li>A file called "docIndex" of format {@code SequenceFile<IntWritable,Text>}.</li></ul>
 * The input file can be regenerated by joining the two output files on the generated int key.
 * In other words, {@code RowIdJob} replaces the document text ids by integers.
 * The original document text ids can still be retrieved from the "docIndex".
 */
public class RowIdJob extends AbstractJob {
    private static final Logger log = LoggerFactory.getLogger(RowIdJob.class);

    @SuppressWarnings("deprecation")
    @Override
    public int run(String[] args) throws Exception {

        addInputOption();
        addOutputOption();

        Map<String, List<String>> parsedArgs = parseArguments(args);
        if (parsedArgs == null) {
            return -1;
        }

        Configuration conf = getConf();
        FileSystem fs = FileSystem.get(conf);

        Path outputPath = getOutputPath();
        Path indexPath = new Path(outputPath, "docIndex");
        Path matrixPath = new Path(outputPath, "matrix");

        try (SequenceFile.Writer indexWriter = SequenceFile.createWriter(fs, conf, indexPath, IntWritable.class,
                Text.class);
                SequenceFile.Writer matrixWriter = SequenceFile.createWriter(fs, conf, matrixPath,
                        IntWritable.class, VectorWritable.class)) {
            IntWritable docId = new IntWritable();
            int i = 0;
            int numCols = 0;
            for (Pair<Text, VectorWritable> record : new SequenceFileDirIterable<Text, VectorWritable>(
                    getInputPath(), PathType.LIST, PathFilters.logsCRCFilter(), null, true, conf)) {
                VectorWritable value = record.getSecond();
                docId.set(i);
                indexWriter.append(docId, record.getFirst());
                matrixWriter.append(docId, value);
                i++;
                numCols = value.get().size();
            }

            log.info("Wrote out matrix with {} rows and {} columns to {}", i, numCols, matrixPath);
            return 0;
        }
    }

    public static void main(String[] args) throws Exception {
        ToolRunner.run(new RowIdJob(), args);
    }

}