/**
* This file is part of muCommander, http://www.mucommander.com
* Copyright (C) 2002-2016 Maxence Bernard
*
* muCommander is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* muCommander 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package com.mucommander.commons.file.archive.zip.provider;
import java.io.IOException;
import java.io.OutputStream;
import java.util.zip.CRC32;
/**
* ZipEntryOutputStream is an abstract <code>OutputStream</code> used for compressing a Zip entry's data to an
* underlying OutputStream.
*
* <p>The CRC32 checksum is calculated on-the-fly as data gets written to the stream, {@link #getCrc()} returns the
* current checksum value. The {@link #getTotalIn()} and {@link #getTotalOut()} methods keep track of the uncompressed
* and compressed of the supplied data.</p>
*
* <p>There currently are two implementations of this class:
* <ul>
* <li>{@link com.mucommander.commons.file.archive.zip.provider.DeflatedOutputStream}: implements the DEFLATED compression method
* </li>
* <li>{@link com.mucommander.commons.file.archive.zip.provider.StoredOutputStream}: implements the STORED compression method
* (i.e. no compression)</li>
* </ul>
* </p>
*
* <p>--------------------------------------------------------------------------------------------------------------<br>
* <br>
* This class is based off the <code>org.apache.tools.zip</code> package of the <i>Apache Ant</i> project. The Ant
* code has been modified under the terms of the Apache License which you can find in the bundled muCommander license
* file. It was forked at version 1.7.0 of Ant.</p>
*
* @author Maxence Bernard
*/
public abstract class ZipEntryOutputStream extends OutputStream {
/** The underlying stream where the compressed data is sent */
protected OutputStream out;
/** Compression method (DEFLATED or STORED) */
protected int method;
/** The CRC32 instance that calculates the checksum */
protected CRC32 crc = new CRC32();
/**
* Creates a new <code>EntryOutputStream</code> that writes compressed data to the given <code>OutputStream</code>
* and automatically updates the supplied <code>CRC32</code> checksum.
*
* @param out the OutputStream where the compressed data is sent to
* @param method the compression method, {@link ZipConstants#DEFLATED} or {@link ZipConstants#STORED}
*/
public ZipEntryOutputStream(OutputStream out, int method) {
this.out = out;
this.method = method;
}
/**
* Returns the compression method used for writing the supplied data.
*
* @return the compression method used for writing the supplied data
*/
public int getMethod() {
return method;
}
/**
* Returns the CRC value of the data written so far.
*
* @return the CRC value of the data written so far.
*/
public long getCrc() {
return crc.getValue();
}
/////////////////////////////////////////
// Partial OutputStream implementation //
/////////////////////////////////////////
@Override
public void write(int b) throws IOException {
byte[] array = new byte[1];
array[0] = (byte) (b & 0xff);
write(array, 0, 1);
}
/**
* Flushes the underlying <code>OutputStream</code>.
*/
@Override
public void flush() throws IOException {
out.flush();
}
//////////////////////
// Abstract methods //
//////////////////////
/**
* Returns the uncompressed size of the data written so far.
*
* @return the uncompressed size of the data written so far
*/
public abstract int getTotalIn();
/**
* Returns the compressed size of the data written so far.
*
* @return the compressed size of the data written so far
*/
public abstract int getTotalOut();
}