/*******************************************************************************
*Copyright (c) 2009  Eucalyptus Systems, Inc.
* 
*  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, only version 3 of the License.
* 
* 
*  This file 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, see <http://www.gnu.org/licenses/>.
* 
*  Please contact Eucalyptus Systems, Inc., 130 Castilian
*  Dr., Goleta, CA 93101 USA or visit <http://www.eucalyptus.com/licenses/>
*  if you need additional information or have any questions.
* 
*  This file may incorporate work covered under the following copyright and
*  permission notice:
* 
*    Software License Agreement (BSD License)
* 
*    Copyright (c) 2008, Regents of the University of California
*    All rights reserved.
* 
*    Redistribution and use of this software in source and binary forms, with
*    or without modification, are permitted provided that the following
*    conditions are met:
* 
*      Redistributions of source code must retain the above copyright notice,
*      this list of conditions and the following disclaimer.
* 
*      Redistributions in binary form must reproduce the above copyright
*      notice, this list of conditions and the following disclaimer in the
*      documentation and/or other materials provided with the distribution.
* 
*    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
*    IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
*    TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
*    PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
*    OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
*    EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
*    PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
*    PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
*    LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
*    NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
*    SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. USERS OF
*    THIS SOFTWARE ACKNOWLEDGE THE POSSIBLE PRESENCE OF OTHER OPEN SOURCE
*    LICENSED MATERIAL, COPYRIGHTED MATERIAL OR PATENTED MATERIAL IN THIS
*    SOFTWARE, AND IF ANY SUCH MATERIAL IS DISCOVERED THE PARTY DISCOVERING
*    IT MAY INFORM DR. RICH WOLSKI AT THE UNIVERSITY OF CALIFORNIA, SANTA
*    BARBARA WHO WILL THEN ASCERTAIN THE MOST APPROPRIATE REMEDY, WHICH IN
*    THE REGENTS’ DISCRETION MAY INCLUDE, WITHOUT LIMITATION, REPLACEMENT
*    OF THE CODE SO IDENTIFIED, LICENSING OF THE CODE SO IDENTIFIED, OR
*    WITHDRAWAL OF THE CODE CAPABILITY TO THE EXTENT NEEDED TO COMPLY WITH
*    ANY SUCH LICENSES OR RIGHTS.
*******************************************************************************/
package edu.ucsb.eucalyptus.cloud.ws;

import java.io.ByteArrayOutputStream;
import java.io.RandomAccessFile;
import java.util.zip.GZIPOutputStream;

import org.apache.log4j.Logger;
import org.jboss.netty.buffer.ChannelBuffers;
import org.jboss.netty.handler.stream.ChunkedInput;

import edu.ucsb.eucalyptus.constants.IsData;

public class CompressedChunkedFile implements ChunkedInput, IsData {
	private Logger LOG = Logger.getLogger( CompressedChunkedFile.class );
	private RandomAccessFile file;
	private long offset;
	private int CHUNK_SIZE = 8192;
	private long fileLength;

	public CompressedChunkedFile(RandomAccessFile file, long fileLength) {
		this.file = file;
		this.offset = 0;
		this.fileLength = fileLength;
	}

	public CompressedChunkedFile(RandomAccessFile file, long start, long end, int chunkSize) {
		this.file = file;
		this.offset = start;
		this.fileLength = end;
		CHUNK_SIZE = chunkSize;
	}
	
	@Override
	public void close() throws Exception {
		file.close();
	}

	@Override
	public boolean hasNextChunk() throws Exception {
		return offset < fileLength && file.getChannel().isOpen();
	}

	@Override
	public Object nextChunk() throws Exception {
		long offset = this.offset;
		if (offset >= fileLength) {
			return null;
		}
		int chunkSize = (int) Math.min(CHUNK_SIZE, fileLength - offset);
		byte[] chunk = new byte[chunkSize];
		file.readFully(chunk);
		this.offset = offset + chunkSize;
		ByteArrayOutputStream out = new ByteArrayOutputStream();
		GZIPOutputStream zip = new GZIPOutputStream(out);
		zip.write(chunk);
		zip.close();
		return ChannelBuffers.wrappedBuffer(out.toByteArray());
	}	
}