/*
* Copyright (C) 2009 eXo Platform SAS.
*
* This 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 software 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 software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.exoplatform.services.jcr.impl.dataflow.serialization;
import org.exoplatform.services.jcr.dataflow.serialization.ObjectReader;
import org.exoplatform.services.jcr.dataflow.serialization.SerializationConstants;
import org.exoplatform.services.jcr.impl.Constants;
import org.exoplatform.services.jcr.impl.util.io.PrivilegedFileHelper;
import java.io.EOFException;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.StreamCorruptedException;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
/**
* Created by The eXo Platform SAS. <br/>
* Date: 15.04.2009
*
* @author <a href="mailto:peter.nedonosko@exoplatform.com.ua">Peter Nedonosko</a>
* @version $Id: FileObjectReaderImpl.java 34801 2009-07-31 15:44:50Z dkatayev $
*/
public class FileObjectReaderImpl implements ObjectReader
{
/**
* The file channel to reading.
*/
private final FileChannel channel;
/**
* FileObjectReaderImpl constructor.
*
* @param file
* Source file to reading
* @throws FileNotFoundException
* if file does not exist
*/
public FileObjectReaderImpl(File file) throws FileNotFoundException
{
this.channel = PrivilegedFileHelper.fileInputStream(file).getChannel();
}
/**
* {@inheritDoc}
*/
public void close() throws IOException
{
channel.close();
}
/**
* Reads a sequence of bytes from file into the given buffer.
*
* @param dst
* buffer
* @throws IOException
* if any Exception is occurred
*/
private void readFully(ByteBuffer dst) throws IOException
{
int r = channel.read(dst);
if (r < 0)
throw new EOFException();
if (r < dst.capacity() && r > 0)
throw new StreamCorruptedException("Unexpected EOF in middle of data block.");
}
/**
* {@inheritDoc}
*/
public boolean readBoolean() throws IOException
{
int v = readInt();
if (v < 0) // TODO ?
throw new EOFException();
return v != 0;
}
/**
* {@inheritDoc}
*/
public byte readByte() throws IOException
{
ByteBuffer dst = ByteBuffer.allocate(1);
readFully(dst);
return dst.get();
}
/**
* {@inheritDoc}
*/
public void readFully(byte[] b) throws IOException
{
ByteBuffer dst = ByteBuffer.wrap(b);
readFully(dst);
}
/**
* {@inheritDoc}
*/
public int readInt() throws IOException
{
ByteBuffer dst = ByteBuffer.allocate(4);
readFully(dst);
return dst.asIntBuffer().get();
}
/**
* {@inheritDoc}
*/
public long readLong() throws IOException
{
ByteBuffer dst = ByteBuffer.allocate(8);
readFully(dst);
return dst.asLongBuffer().get();
}
/**
* {@inheritDoc}
*/
public String readString() throws IOException
{
ByteBuffer dst = ByteBuffer.allocate(readInt());
readFully(dst);
return new String(dst.array(), Constants.DEFAULT_ENCODING);
}
/**
* {@inheritDoc}
*/
public long skip(long n) throws IOException
{
if (n <= 0)
return 0;
channel.position(channel.position() + n);
return n;
}
/**
* {@inheritDoc}
*/
public long read(OutputStream stream, long length) throws IOException
{
if (stream instanceof FileOutputStream)
{
// use NIO
return channel.transferTo(0, length, ((FileOutputStream)stream).getChannel());
}
else
{
// bytes copy
ByteBuffer buff = ByteBuffer.allocate(SerializationConstants.INTERNAL_BUFFER_SIZE);
int r;
int readed = 0;
while ((r = channel.read(buff)) <= 0)
{
stream.write(buff.array(), 0, r);
buff.rewind();
readed += r;
}
return readed;
}
}
}