/*
* Eoulsan development code
*
* This code may be freely distributed and modified under the
* terms of the GNU Lesser General Public License version 2.1 or
* later and CeCILL-C. This should be distributed with the code.
* If you do not have a copy, see:
*
* http://www.gnu.org/licenses/lgpl-2.1.txt
* http://www.cecill.info/licences/Licence_CeCILL-C_V1-en.txt
*
* Copyright for this code is held jointly by the Genomic platform
* of the Institut de Biologie de l'École normale supérieure and
* the individual authors. These should be listed in @author doc
* comments.
*
* For more information on the Eoulsan project and its aims,
* or to join the Eoulsan Google group, visit the home page
* at:
*
* http://outils.genomique.biologie.ens.fr/eoulsan
*
*/
package fr.ens.biologie.genomique.eoulsan.io;
import java.io.FilterInputStream;
import java.io.IOException;
import java.io.InputStream;
import org.apache.hadoop.mapreduce.Counter;
/**
* This class implements a FilterInputStream that inform Hadoop of the progress
* of task using counters.
* @since 1.0
* @author Laurent Jourdren
*/
public final class ProgressCounterInputStream extends FilterInputStream {
private static final int MAX = 10 * 1024 * 1024;
private final Counter counter;
private int sum;
@Override
public final int read() throws IOException {
return incrementCounter(super.read());
}
@Override
public final int read(final byte[] b, final int off, final int len)
throws IOException {
return incrementCounter(super.read(b, off, len));
}
@Override
public final int read(final byte[] b) throws IOException {
return incrementCounter(super.read(b));
}
@Override
public final void close() throws IOException {
super.close();
this.counter.increment(this.sum);
}
//
// Other methods
//
private int incrementCounter(final int bytes) {
this.sum += bytes;
if (this.sum > MAX) {
this.counter.increment(this.sum);
this.sum = 0;
}
return bytes;
}
//
// Constructor
//
public ProgressCounterInputStream(final InputStream is,
final Counter counter) {
super(is);
if (counter == null) {
throw new NullPointerException("The counter to use is null.");
}
this.counter = counter;
}
}