/*
* $Id$
*
* Copyright (C) 2003-2015 JNode.org
*
* This library 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 2.1 of the License, or
* (at your option) any later version.
*
* This library 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 library; If not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
package org.jnode.apps.vmware.disk.handler.sparse;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
import org.apache.log4j.Logger;
import org.jnode.apps.vmware.disk.IOUtils;
import org.jnode.apps.vmware.disk.handler.UnsupportedFormatException;
/**
* Wrote from the 'Virtual Disk Format 1.0' specifications (from VMWare).
*
* @author Fabien DUMINY (fduminy at jnode dot org)
*
*/
public class SparseExtentHeaderRW {
static final Logger LOG = Logger.getLogger(SparseExtentHeaderRW.class);
private static final byte singleEndLineChar = '\n';
private static final byte nonEndLineChar = ' ';
private static final byte doubleEndLineChar1 = '\r';
private static final byte doubleEndLineChar2 = '\n';
private static final int PAD_SIZE = 435;
private static final int MAGIC_NUMBER = 0x564d444b;
private static final int VERSION = 1;
private static final byte TRUE = (byte) 1;
private static final byte FALSE = (byte) 0;
private static final int numGTEsPerGT = 512;
/**
*
* @param bb
* @return
* @throws IOException
* @throws UnsupportedFormatException
*/
public SparseExtentHeader read(ByteBuffer bb) throws IOException, UnsupportedFormatException {
// TODO optimise the size
// ByteBuffer bb = IOUtils.getByteBuffer(raf, 1024);
SparseExtentHeader header = new SparseExtentHeader();
int magicNum = bb.getInt();
LOG.debug("magicNum=" + Long.toHexString(magicNum));
if (magicNum != MAGIC_NUMBER) {
throw new UnsupportedFormatException("not the magic number");
}
int version = bb.getInt();
if (version != VERSION) {
throw new IOException("bad version number (found:" + version + ")");
}
int flags = bb.getInt();
header.setValidNewLineDetectionTest((flags & 0x01) == 0x01); // bit 0
header.setRedundantGrainTableWillBeUsed((flags & 0x02) == 0x02); // bit
// 1
header.setCapacity(bb.getLong());
header.setGrainSize(bb.getLong());
header.setDescriptorOffset(bb.getLong());
header.setDescriptorSize(bb.getLong());
LOG.debug("read: offset(NumGTEsPerGT)=" + bb.position());
int nb = bb.getInt();
if (nb != numGTEsPerGT) {
throw new IOException("bad number of entries per grain table (found:" + nb + ")");
}
header.setNumGTEsPerGT(nb);
header.setRgdOffset(bb.getLong());
LOG.debug("read: offset(GdOffset)=" + bb.position());
header.setGdOffset(bb.getLong());
header.setOverHead(bb.getLong());
header.setUncleanShutdown(bb.get() == TRUE);
LOG.debug("read: offset(singleEndLineChar)=" + bb.position());
byte b = bb.get();
if (b != singleEndLineChar) {
throw new IOException("file corrupted after a FTP (singleEndLineChar=" + b + ")");
}
b = bb.get();
if (b != nonEndLineChar) {
throw new IOException("file corrupted after a FTP (nonEndLineChar=" + b + ")");
}
b = bb.get();
if (b != doubleEndLineChar1) {
throw new IOException("file corrupted after a FTP (doubleEndLineChar1=" + b + ")");
}
b = bb.get();
if (b != doubleEndLineChar2) {
throw new IOException("file corrupted after a FTP (doubleEndLineChar2=" + b + ")");
}
if (bb.remaining() < PAD_SIZE) {
throw new UnsupportedFormatException("bad pad size (size=" + bb.remaining() + ")");
}
// additional/computed attributes
IOUtils.computeGrainTableCoverage(header);
if (header.getGrainSize() <= 8) {
throw new IOException("grainSize must be greater than 8 (actual:" +
header.getGrainSize() + ")");
}
if (!IOUtils.isPowerOf2(header.getGrainSize())) {
throw new IOException("grainSize must be a power of 2 (actual:" +
header.getGrainSize() + ")");
}
// TODO: according to the spec the following test shouldn't fail but
// **it is actually failing**
// if((header.getCapacity() % header.getGrainSize()) != 0)
// {
// throw new IOException("capacity must be a multiple of grainSize
// (actual grainSize:"+header.getGrainSize()+", actual
// capacity="+header.getCapacity()+")");
// }
LOG.debug("header=" + header);
return header;
}
/**
*
* @param channel
* @param header
* @throws IOException
*/
public void write(FileChannel channel, SparseExtentHeader header) throws IOException {
ByteBuffer bb = IOUtils.allocate(1024);
bb.putInt(MAGIC_NUMBER);
bb.putInt(VERSION);
int flags = 0;
if (header.isValidNewLineDetectionTest()) {
flags &= 0x01; // bit 0
}
if (header.isRedundantGrainTableWillBeUsed()) {
flags &= 0x02; // bit 1
}
bb.putInt(flags);
bb.putLong(header.getCapacity());
bb.putLong(header.getGrainSize());
bb.putLong(header.getDescriptorOffset());
bb.putLong(header.getDescriptorSize());
LOG.debug("write: offset(NumGTEsPerGT)=" + bb.position());
bb.putInt(header.getNumGTEsPerGT());
bb.putLong(header.getRgdOffset());
LOG.debug("write: offset(GdOffset)=" + bb.position());
bb.putLong(header.getGdOffset());
bb.putLong(header.getOverHead());
bb.put(header.isUncleanShutdown() ? TRUE : FALSE);
LOG.debug("write: offset(singleEndLineChar)=" + bb.position());
bb.put(singleEndLineChar);
bb.put(nonEndLineChar);
bb.put(doubleEndLineChar1);
bb.put(doubleEndLineChar2);
for (int i = 0; i < PAD_SIZE; i++) {
bb.put((byte) 0);
}
bb.limit(bb.position());
bb.rewind();
LOG.debug("write: buffer=" + bb);
channel.write(bb);
}
}