org.interactiverobotics.source_code_crawler.step6.TextFileRecordReader.java Source code

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Here is the source code for org.interactiverobotics.source_code_crawler.step6.TextFileRecordReader.java

Source

/*
 * TextFileRecordReader.java
 *
 * Copyright (C) 2016 Pavel Prokhorov (pavelvpster@gmail.com)
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

package org.interactiverobotics.source_code_crawler.step6;

import java.io.IOException;

import org.apache.hadoop.conf.Configuration;
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;

/**
 * TextFileRecordReader.
 */
public class TextFileRecordReader extends RecordReader<Text, Text> {

    private FileSplit fileSplit;
    private Configuration configuration;
    private Text key = new Text();
    private Text value = new Text();
    private boolean processed = false;

    @Override
    public void initialize(final InputSplit split, final TaskAttemptContext context)
            throws IOException, InterruptedException {
        this.fileSplit = (FileSplit) split;
        this.configuration = context.getConfiguration();
    }

    @Override
    public boolean nextKeyValue() throws IOException, InterruptedException {
        if (!processed) {
            final byte[] contents = new byte[(int) fileSplit.getLength()];
            final Path file = fileSplit.getPath();
            final FileSystem fileSystem = file.getFileSystem(configuration);
            FSDataInputStream in = null;
            try {
                in = fileSystem.open(file);
                IOUtils.readFully(in, contents, 0, contents.length);
                key.set(file.toString());
                value.set(contents, 0, contents.length);
            } finally {
                IOUtils.closeStream(in);
            }
            processed = true;
            return true;
        }
        return false;
    }

    @Override
    public Text getCurrentKey() throws IOException, InterruptedException {
        return key;
    }

    @Override
    public Text getCurrentValue() throws IOException, InterruptedException {
        return value;
    }

    @Override
    public float getProgress() throws IOException {
        return processed ? 1.0f : 0.0f;
    }

    @Override
    public void close() throws IOException {
    }
}