/*
* 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.IOException;
import java.io.InputStream;
/**
* This class define an InputStream that concatenate InputStream.
* @since 1.0
* @author Laurent Jourdren
*/
public abstract class AbstractConcatInputStream extends InputStream {
private InputStream is;
/**
* Test if there is an other InputStream to concatenate
* @return true if an other InputStream is available
*/
protected abstract boolean hasNextInputStream();
/**
* Get the next InputStream to concatenate
* @return the next InputStream to concatenate
* @throws IOException if an error occurs while creating InputStream
*/
protected abstract InputStream nextInputStream() throws IOException;
@Override
public boolean markSupported() {
return false;
}
@Override
public int read() throws IOException {
if (this.is == null) {
if (!hasNextInputStream()) {
return -1;
}
this.is = nextInputStream();
}
int b = this.is.read();
if (b == -1) {
if (!hasNextInputStream()) {
return -1;
}
this.is.close();
this.is = nextInputStream();
return read();
}
return b;
}
@Override
public int read(final byte[] b, final int off, final int len)
throws IOException {
// No input stream
if (this.is == null) {
if (!hasNextInputStream()) {
return -1;
}
this.is = nextInputStream();
}
final int l = this.is.read(b, off, len);
// Nothing to read
if (l == -1) {
if (!hasNextInputStream()) {
return -1;
}
this.is.close();
this.is = nextInputStream();
return read(b, off, len);
}
// read the start of the next stream if needed
if (l < len) {
for (int i = l; i < len; i++) {
final int b2 = read();
if (b2 == -1) {
return i;
}
b[i] = (byte) b2;
}
return len;
}
// return the number of byte read
return l;
}
@Override
public int read(final byte[] b) throws IOException {
return read(b, 0, b.length);
}
@Override
public void close() throws IOException {
if (this.is != null) {
this.is.close();
}
}
}