Deflation.java

/*
 * Copyright (c) 2001-2004 Caucho Technology, Inc.  All rights reserved.
 *
 * The Apache Software License, Version 1.1
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. 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.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:
 *       "This product includes software developed by the
 *        Caucho Technology (http://www.caucho.com/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "Hessian", "Resin", and "Caucho" must not be used to
 *    endorse or promote products derived from this software without prior
 *    written permission. For written permission, please contact
 *    info@caucho.com.
 *
 * 5. Products derived from this software may not be called "Resin"
 *    nor may "Resin" appear in their names without prior written
 *    permission of Caucho Technology.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED 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 CAUCHO TECHNOLOGY OR ITS 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.
 *
 * @author Scott Ferguson
 */

package com.caucho.hessian4.io;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.zip.DeflaterOutputStream;
import java.util.zip.InflaterInputStream;

public class Deflation extends HessianEnvelope {
  public Deflation()
  {
  }

  public Hessian2Output wrap(Hessian2Output out)
    throws IOException
  {
    OutputStream os = new DeflateOutputStream(out);
    
    Hessian2Output filterOut = new Hessian2Output(os);

    filterOut.setCloseStreamOnClose(true);
    
    return filterOut;
  }

  public Hessian2Input unwrap(Hessian2Input in)
    throws IOException
  {
    int version = in.readEnvelope();

    String method = in.readMethod();

    if (! method.equals(getClass().getName()))
      throw new IOException("expected hessian Envelope method '" +
			    getClass().getName() + "' at '" + method + "'");

    return unwrapHeaders(in);
  }

  public Hessian2Input unwrapHeaders(Hessian2Input in)
    throws IOException
  {
    InputStream is = new DeflateInputStream(in);

    Hessian2Input filter = new Hessian2Input(is);
    
    filter.setCloseStreamOnClose(true);
    
    return filter;
  }
  
  static class DeflateOutputStream extends OutputStream {
    private Hessian2Output _out;
    private OutputStream _bodyOut;
    private DeflaterOutputStream _deflateOut;
    
    DeflateOutputStream(Hessian2Output out)
      throws IOException
    {
      _out = out;

      _out.startEnvelope(Deflation.class.getName());
    
      _out.writeInt(0);

      _bodyOut = _out.getBytesOutputStream();
    
      _deflateOut = new DeflaterOutputStream(_bodyOut);
    }
    
    public void write(int ch)
      throws IOException
    {
      _deflateOut.write(ch);
    }
    
    public void write(byte []buffer, int offset, int length)
      throws IOException
    {
      _deflateOut.write(buffer, offset, length);
    }

    public void close()
      throws IOException
    {
      Hessian2Output out = _out;
      _out = null;

      if (out != null) {
	_deflateOut.close();
	_bodyOut.close();

	out.writeInt(0);

        out.completeEnvelope();
          
	out.close();
      }
    }
  }
  
  static class DeflateInputStream extends InputStream {
    private Hessian2Input _in;
    
    private InputStream _bodyIn;
    private InflaterInputStream _inflateIn;
    
    DeflateInputStream(Hessian2Input in)
      throws IOException
    {
      _in = in;

      int len = in.readInt();

      if (len != 0)
        throw new IOException("expected no headers");
      
      _bodyIn = _in.readInputStream();

      _inflateIn = new InflaterInputStream(_bodyIn);
    }
    
    public int read()
      throws IOException
    {
      return _inflateIn.read();
    }
    
    public int read(byte []buffer, int offset, int length)
      throws IOException
    {
      return _inflateIn.read(buffer, offset, length);
    }

    public void close()
      throws IOException
    {
      Hessian2Input in = _in;
      _in = null;

      if (in != null) {
	_inflateIn.close();
	_bodyIn.close();

	int len = in.readInt();

	if (len != 0)
	  throw new IOException("Unexpected footer");

        in.completeEnvelope();

	in.close();
      }
    }
  }
}