co.nubetech.hiho.mapreduce.lib.input.FileStreamRecordReader.java Source code

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Here is the source code for co.nubetech.hiho.mapreduce.lib.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.mapreduce.lib.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.mapreduce.InputSplit;
import org.apache.hadoop.mapreduce.RecordReader;
import org.apache.hadoop.mapreduce.TaskAttemptContext;
import org.apache.hadoop.mapreduce.lib.input.FileSplit;
import org.apache.log4j.Logger;

public class FileStreamRecordReader extends RecordReader<Text, FSDataInputStream> {
    private FileSplit split;
    private TaskAttemptContext context;
    private FSDataInputStream stream;
    private boolean isRead = false;
    private String fileName;

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

    public FileStreamRecordReader(FileSplit split, TaskAttemptContext context) {
        this.split = split;
        this.context = context;
    }

    public void initialize(InputSplit genericSplit, TaskAttemptContext context) throws IOException {
        this.split = (FileSplit) genericSplit;
        this.context = context;

    }

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

    @Override
    public Text getCurrentKey() {
        return new Text(fileName);
    }

    @Override
    public FSDataInputStream getCurrentValue() {
        logger.debug("Returning value ");
        return stream;
    }

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

    @Override
    public boolean nextKeyValue() throws IOException {
        logger.debug("Inside nextKeyValue");
        if (!isRead) {
            Path file = split.getPath();
            logger.debug("Path is " + file);
            fileName = file.getName();
            FileSystem fs = file.getFileSystem(context.getConfiguration());
            stream = fs.open(file);
            logger.debug("Opened stream");
            isRead = true;
            return true;
        }
        return false;
    }

}