edu.indiana.d2i.htrc.io.index.lucene.LuceneIDFormat.java Source code

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/*
#
# Copyright 2012 The Trustees of Indiana University
#
# 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.
#
# -----------------------------------------------------------------
#
# Project: knn
# File:  LuceneIDFormat.java
# Description:  
#
# -----------------------------------------------------------------
# 
*/

package edu.indiana.d2i.htrc.io.index.lucene;

import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.InputSplit;
import org.apache.hadoop.mapreduce.JobContext;
import org.apache.hadoop.mapreduce.RecordReader;
import org.apache.hadoop.mapreduce.TaskAttemptContext;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.mahout.math.VectorWritable;

import edu.indiana.d2i.htrc.HTRCConstants;
import edu.indiana.d2i.htrc.io.dataapi.IDInputFormat;
import edu.indiana.d2i.htrc.io.dataapi.IDInputSplit;

public class LuceneIDFormat extends FileInputFormat<Text, VectorWritable> {

    private static final Log logger = LogFactory.getLog(LuceneIDFormat.class);

    @Override
    public List<InputSplit> getSplits(JobContext job) throws IOException {
        int numIdsInSplit = job.getConfiguration().getInt(HTRCConstants.MAX_IDNUM_SPLIT, (int) 1e6);

        String line = null;
        IDInputSplit split = new IDInputSplit();
        List<InputSplit> splits = new ArrayList<InputSplit>();
        Path[] dirs = getInputPaths(job);

        try {
            for (int i = 0; i < dirs.length; i++) {
                FileSystem fs = dirs[i].getFileSystem(job.getConfiguration());
                DataInputStream fsinput = new DataInputStream(fs.open(dirs[i]));
                BufferedReader reader = new BufferedReader(new InputStreamReader(fsinput));
                while ((line = reader.readLine()) != null) {
                    split.addID(line);
                    if (split.getLength() >= numIdsInSplit) {
                        splits.add(split);
                        split = new IDInputSplit();
                    }
                }
                reader.close();
            }
            if (split != null && split.getLength() != 0)
                splits.add(split);
        } catch (InterruptedException e) {
            logger.error(e);
        }

        logger.info("#Splits " + splits.size());
        return splits;
    }

    @Override
    public RecordReader<Text, VectorWritable> createRecordReader(InputSplit arg0, TaskAttemptContext arg1)
            throws IOException, InterruptedException {
        return new LuceneRecordReader();
    }
}