co.nubetech.hiho.mapred.input.FileStreamRecordReader.java Source code

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Here is the source code for co.nubetech.hiho.mapred.input.FileStreamRecordReader.java

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/**
 * Copyright 2010 Nube Technologies
 *
 * 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 co.nubetech.hiho.mapred.input;

import java.io.IOException;

import org.apache.hadoop.fs.FSDataInputStream;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IOUtils;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapred.FileSplit;
import org.apache.hadoop.mapred.InputSplit;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.RecordReader;
import org.apache.hadoop.mapred.Reporter;
import org.apache.log4j.Logger;

/**
 * Updated version of {@link co.nubetech.hiho.mapreduce.lib.input.FileStreamInputFormat}.
 *
 */
public class FileStreamRecordReader implements RecordReader<Text, FSDataInputStream> {
    private FileSplit split;
    private FSDataInputStream stream;
    private boolean isRead = false;
    private String fileName;
    private JobConf configuration;
    private Reporter reporter;

    final static Logger logger = Logger
            .getLogger(co.nubetech.hiho.mapreduce.lib.input.FileStreamRecordReader.class);

    public FileStreamRecordReader(InputSplit split, JobConf conf, Reporter reporter) throws IOException {
        this.reporter = reporter;
        initialize(split, conf);
    }

    public void initialize(InputSplit genericSplit, JobConf conf) throws IOException {
        this.split = (FileSplit) genericSplit;
        this.configuration = conf;

    }

    @Override
    public void close() throws IOException {
        if (stream != null) {
            IOUtils.closeStream(stream);
        }
    }

    @Override
    public Text createKey() {
        logger.debug("Creating key");
        return new Text();
    }

    @Override
    public FSDataInputStream createValue() {
        logger.debug("Creating value");
        FSDataInputStream stream = null;
        Path file = split.getPath();
        logger.debug("Path is " + file);
        fileName = file.getName();
        try {
            FileSystem fs = file.getFileSystem(configuration);
            stream = new FSDataInputStream(fs.open(file));
        } catch (IOException e) {
            e.printStackTrace();
        }
        logger.debug("Opened stream");
        return stream;
    }

    @Override
    public float getProgress() throws IOException {
        return 0f;
        // dummy
    }

    @Override
    public boolean next(Text key, FSDataInputStream stream) throws IOException {
        logger.debug("Inside next");
        if (isRead) {
            return false;
        } else {
            key.set(fileName);
            isRead = true;
            return true;
        }
    }

    @Override
    public long getPos() throws IOException {
        // TODO Auto-generated method stub
        return 0;
    }
}