/*
* JMule - Java file sharing client
* Copyright (C) 2007-2008 JMule team ( jmule@jmule.org / http://jmule.org )
*
* Any parts of this program derived from other projects, or contributed
* by third-party developers are copyrighted by their respective authors.
*
* 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 2
* 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, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
*/
package org.jmule.core.utils;
import static org.jmule.core.edonkey.E2DKConstants.PARTSIZE;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.channels.FileChannel;
import org.jmule.core.edonkey.FileHash;
import org.jmule.core.edonkey.PartHashSet;
/**
*
* @author binary256
* @version $$Revision: 1.2 $$
* Last changed by $$Author: binary255 $$ on $$Date: 2009/09/17 18:32:25 $$
*/
public class MD4FileHasher {
public static PartHashSet calcHashSets(FileChannel fileChannel) {
try {
fileChannel.position(0);
int i;
int c;
long position = 0L;
ByteBuffer hashset;
MD4 msgDigest = new MD4();
ByteBuffer bb = ByteBuffer.allocateDirect(8192).order(ByteOrder.LITTLE_ENDIAN);
ByteBuffer di = ByteBuffer.allocate(16).order(ByteOrder.LITTLE_ENDIAN);
c = (int) ((fileChannel.size() + PARTSIZE - 1) / PARTSIZE);
// we will need space for c Parts
hashset = ByteBuffer.allocate(16 * (c>0?c:1)).order(ByteOrder.LITTLE_ENDIAN);
for (i = 1; i < c; i++) {
while (position <= (i * PARTSIZE - bb.capacity())) {
position+=fileChannel.read(bb, position);
bb.flip();
msgDigest.update(bb);
bb.rewind();
}
if (position < (i * PARTSIZE)) {
bb.limit((int) ((i * PARTSIZE) - position));
position+=fileChannel.read(bb, position);
bb.flip();
msgDigest.update(bb);
bb.rewind();
}
hashset.limit(16 * i);
//update hashset - add a hash
msgDigest.finalDigest(hashset);
}
if (c > 0) {
while (position < (fileChannel.size())) {
position+=fileChannel.read(bb, position);
bb.flip();
msgDigest.update(bb);
bb.rewind();
}
hashset.limit(16 * i);
}
msgDigest.finalDigest(hashset);
hashset.flip();
if (c > 1) {
msgDigest.update(hashset);
msgDigest.finalDigest(di);
} else {
di.put(hashset);
}
di.rewind();
hashset.rewind();
//hashes
byte[][] hashes = new byte[(c!=1)?(c + 1):1][16];
di.get(hashes[0]);
for (int j = 1; j < hashes.length; j++) {
hashset.get(hashes[j]);
}
hashset.rewind();
PartHashSet fileHashSet = new PartHashSet(new FileHash(hashes[0]));
for(int j=1; j < hashes.length;j++){
fileHashSet.add(hashes[j]);
}
return fileHashSet;
} catch (Throwable e) {e.printStackTrace();}
return null;
}
}