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/*
 *
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright 2007-2008 Sun Microsystems, Inc. All rights reserved.
 *
 * The contents of this file are subject to the terms of either the GNU
 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License. You can obtain
 * a copy of the License at https://glassfish.dev.java.net/public/CDDL+GPL.html
 * or glassfish/bootstrap/legal/LICENSE.txt.  See the License for the specific
 * language governing permissions and limitations under the License.
 *
 * When distributing the software, include this License Header Notice in each
 * file and include the License file at glassfish/bootstrap/legal/LICENSE.txt.
 * Sun designates this particular file as subject to the "Classpath" exception
 * as provided by Sun in the GPL Version 2 section of the License file that
 * accompanied this code.  If applicable, add the following below the License
 * Header, with the fields enclosed by brackets [] replaced by your own
 * identifying information: "Portions Copyrighted [year]
 * [name of copyright owner]"
 *
 * Contributor(s):
 *
 * If you wish your version of this file to be governed by only the CDDL or
 * only the GPL Version 2, indicate your decision by adding "[Contributor]
 * elects to include this software in this distribution under the [CDDL or GPL
 * Version 2] license."  If you don't indicate a single choice of license, a
 * recipient has the option to distribute your version of this file under
 * either the CDDL, the GPL Version 2 or to extend the choice of license to
 * its licensees as provided above.  However, if you add GPL Version 2 code
 * and therefore, elected the GPL Version 2 license, then the option applies
 * only if the new code is made subject to such option by the copyright
 * holder.
 *
 */
// $Id: ZlibOutputStream.java 105 2007-08-07 07:45:45Z pornin $
/*
 * Copyright (c) 2007  Thomas Pornin
 * 
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 * 
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

package org.atmosphere.gwt.server.deflate;

import org.atmosphere.gwt.server.deflate.Deflater;
import java.io.IOException;
import java.io.OutputStream;

/**
 * 
 * This class implements a stream which compresses data into the zlib format (RFC 1950).
 * 
 * 
 * 
 * The compression level can be specified, as a symbolic value identical to what the Deflater class
 * expects. The default compression level is MEDIUM.
 * 
 * 
 * @version $Revision: 105 $
 * @author Thomas Pornin
 */

public class DeflaterOutputStream extends OutputStream {
	
	private Deflater deflater;
	
	/**
	 * Create the stream with the provided transport stream. The default compression level (MEDIUM) is
	 * used.
	 * 
	 * @param out
	 *            the transport stream
	 * @throws IOException
	 *             on I/O error with the transport stream
	 */
	public DeflaterOutputStream(OutputStream out) throws IOException {
		this(out, Deflater.MEDIUM);
	}
	
	/**
	 * Create the stream with the provided transport stream. The provided compression level is used.
	 * 
	 * @param out
	 *            the transport stream
	 * @param level
	 *            the compression level
	 * @throws IOException
	 *             on I/O error with the transport stream
	 */
	public DeflaterOutputStream(OutputStream out, int level) throws IOException {
		deflater = new Deflater(level);
		deflater.setOut(out);
	}
	
	/**
	 * Close this stream; the transport stream is also closed.
	 * 
	 * @throws IOException
	 *             on I/O error with the transport stream
	 */
	@Override
	public void close() throws IOException {
		deflater.terminate();
		deflater.getOut().close();
	}
	
	/**
	 * Flush this stream; the transport stream is also flushed. At the DEFLATE level, a "sync flush" is performed, which
	 * ensures that output bytes written so far on the transport stream are sufficient to recover all the input bytes
	 * currently processed.
	 * 
	 * @throws IOException
	 *             on I/O error with the transport stream
	 */
	@Override
	public void flush() throws IOException {
		deflater.flushSync(true);
		deflater.getOut().flush();
	}
	
	/** @see OutputStream */
	@Override
	public void write(int b) throws IOException {
		write(new byte[] { (byte) b }, 0, 1);
	}
	
	/** @see OutputStream */
	@Override
	public void write(byte[] buf) throws IOException {
		write(buf, 0, buf.length);
	}
	
	/** @see OutputStream */
	@Override
	public void write(byte[] buf, int off, int len) throws IOException {
		deflater.process(buf, off, len);
	}
}