/*
* $Id$
*
* Copyright (C) 2003-2014 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.io.RandomAccessFile;
import java.nio.ByteBuffer;
import java.nio.IntBuffer;
import java.nio.channels.FileChannel;
import org.apache.log4j.Logger;
import org.jnode.apps.vmware.disk.IOUtils;
import org.jnode.apps.vmware.disk.handler.IOHandler;
/**
* Wrote from the 'Virtual Disk Format 1.0' specifications (from VMWare).
*
* @author Fabien DUMINY (fduminy at jnode dot org)
*
*/
public class AllocationTableRW {
private static final Logger LOG = Logger.getLogger(SparseExtentRW.class);
/**
*
* @param raf
* @param header
* @return
* @throws IOException
*/
public AllocationTable read(RandomAccessFile raf, SparseExtentHeader header) throws IOException {
long nbGrains = header.getCapacity() / header.getGrainSize();
int nbGrainTables = (int) (nbGrains / header.getNumGTEsPerGT());
LOG.debug("read: capacity=" + header.getCapacity() + " grainSize=" + header.getGrainSize() +
" NumGTEsPerGT=" + header.getNumGTEsPerGT() + " => nbGrainTables=" + nbGrainTables);
GrainDirectory grainDirectory = new GrainDirectory(readEntries(raf, nbGrainTables));
GrainTable[] grainTables = new GrainTable[nbGrainTables];
for (int i = 0; i < grainTables.length; i++) {
if (LOG.isDebugEnabled()) {
long pos = raf.getChannel().position();
if ((pos % IOHandler.SECTOR_SIZE) != 0) {
LOG.fatal("read: FATAL: pos not begin of a sector");
}
final long gtOffset = (pos / IOHandler.SECTOR_SIZE);
final long gde = grainDirectory.getEntry(i);
if (gde != gtOffset) {
LOG.fatal("read: FATAL: grainTables[" + i + "] (value:" + gtOffset +
") doesn't match to GrainDirectoryEntry #" + i + "(value:" + gde + ")");
}
raf.getChannel().position(gde);
}
grainTables[i] = new GrainTable(readEntries(raf, header.getNumGTEsPerGT()));
}
return new AllocationTable(grainDirectory, grainTables);
}
/**
*
* @param channel
* @param table
* @throws IOException
*/
public void write(FileChannel channel, AllocationTable table) throws IOException {
write(channel, table.getGrainDirectory());
for (int gtNum = 0; gtNum < table.getNbGrainTables(); gtNum++) {
write(channel, table.getGrainTable(gtNum));
}
}
protected void write(FileChannel channel, EntryArray ea) throws IOException {
ByteBuffer b = IOUtils.allocate(ea.getSize() * IOUtils.INT_SIZE);
IntBuffer ib = b.asIntBuffer();
for (int i = 0; i < ea.getSize(); i++) {
ib.put(ea.getEntry(i));
}
ib.rewind();
channel.write(b);
}
protected int[] readEntries(RandomAccessFile raf, int nbEntries) throws IOException {
IntBuffer bb = IOUtils.getByteBuffer(raf, nbEntries * IOUtils.INT_SIZE).asIntBuffer();
int[] entries = new int[nbEntries];
for (int entryNumber = 0; entryNumber < nbEntries; entryNumber++) {
int entry = bb.get();
if (entry > 0) {
LOG.debug("readEntries: entry[" + entryNumber + "]=" + entry);
}
entries[entryNumber] = entry;
}
return entries;
}
}