com.github.jmabuin.blaspark.io.RowPerLineRecordReader.java Source code

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Here is the source code for com.github.jmabuin.blaspark.io.RowPerLineRecordReader.java

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/**
 * Copyright 2017 Jos Manuel Abun Mosquera <josemanuel.abuin@usc.es>
 *
 * This file is part of BLASpark.
 *
 * BLASpark 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.
 *
 * BLASpark 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 BLASpark. If not, see <http://www.gnu.org/licenses/>.
 */

package com.github.jmabuin.blaspark.io;

import java.io.IOException;

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.LineRecordReader;

/**
 * This class define a custom RecordReader for RowPerLine files for the
 * Hadoop MapReduce framework.
    
 * @author Jos M. Abun
 */
public class RowPerLineRecordReader extends RecordReader<Long, double[]> {

    // input data comes from lrr
    private LineRecordReader lrr = null;

    private Long key = 0L;
    private double[] value;

    private boolean firstSplit = false;

    @Override
    public void close() throws IOException {
        this.lrr.close();
    }

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

    @Override
    public double[] getCurrentValue() throws IOException, InterruptedException {
        return value;
    }

    @Override
    public float getProgress() throws IOException, InterruptedException {
        return this.lrr.getProgress();
    }

    @Override
    public void initialize(final InputSplit inputSplit, final TaskAttemptContext taskAttemptContext)
            throws IOException, InterruptedException {
        this.lrr = new LineRecordReader();
        this.lrr.initialize(inputSplit, taskAttemptContext);

    }

    @Override
    public boolean nextKeyValue() throws IOException, InterruptedException {
        boolean found = false;

        while (!found) {

            if (!this.lrr.nextKeyValue()) {
                return false;
            }

            final String s = this.lrr.getCurrentValue().toString().trim();

            //System.out.println("nextKeyValue() s="+s);

            // Prevent empty lines
            if (s.length() == 0) {
                continue;
            }

            if (s.charAt(0) == '%') {
                this.firstSplit = true;
                //this.firstValues = true;
            } else {
                //To skip the first values in the first split, that are the matrix row number, col number and not zero values
                if (!this.firstSplit) {
                    String[] dataLine = s.split(":");

                    if (dataLine.length != 2) {
                        return false;
                    }

                    this.key = Long.parseLong(dataLine[0]);

                    String doubleValuesString[] = dataLine[1].split(",");

                    double[] doubleValues = new double[doubleValuesString.length];

                    int i = 0;

                    for (String newValue : doubleValuesString) {
                        doubleValues[i] = Double.parseDouble(newValue);

                        i++;
                    }

                    this.value = doubleValues.clone();
                    found = true;
                } else {
                    this.firstSplit = false;
                }
            }

        } //end-while

        return true;
    }

}