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/*
 * Copyright 2012 Jeanfrancois Arcand
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */
// $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 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.
 * 
 *
 * @author Thomas Pornin
 * @version $Revision: 105 $
 */

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);
    }
}