Hessian2StreamingInput.java

/*
 * Copyright (c) 2001-2008 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 "Burlap", "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.util.logging.Level;
import java.util.logging.Logger;

/**
 * Input stream for Hessian 2 streaming requests using WebSocket.
 */
public class Hessian2StreamingInput
{
  private static final Logger log
    = Logger.getLogger(Hessian2StreamingInput.class.getName());
  
  private StreamingInputStream _is;
  private Hessian2Input _in;
  
  /**
   * Creates a new Hessian input stream, initialized with an
   * underlying input stream.
   *
   * @param is the underlying output stream.
   */
  public Hessian2StreamingInput(InputStream is)
  {
    _is = new StreamingInputStream(is);
    _in = new Hessian2Input(_is);
  }

  public void setSerializerFactory(SerializerFactory factory)
  {
    _in.setSerializerFactory(factory);
  }

  public boolean isDataAvailable()
  {
    StreamingInputStream is = _is;
    
    return is != null && is.isDataAvailable();
  }

  public Hessian2Input startPacket()
    throws IOException
  {
    if (_is.startPacket()) {
      _in.resetReferences();
      _in.resetBuffer(); // XXX:
      return _in;
    }
    else
      return null;
  }

  public void endPacket()
    throws IOException
  {
    _is.endPacket();
    _in.resetBuffer(); // XXX:
  }

  public Hessian2Input getHessianInput()
  {
    return _in;
  }

  /**
   * Read the next object
   */
  public Object readObject()
    throws IOException
  {
    _is.startPacket();
    
    Object obj = _in.readStreamingObject();

    _is.endPacket();

    return obj;
  }

  /**
   * Close the output.
   */
  public void close()
    throws IOException
  {
    _in.close();
  }

  static class StreamingInputStream extends InputStream {
    private InputStream _is;
    
    private int _length;
    private boolean _isPacketEnd;

    StreamingInputStream(InputStream is)
    {
      _is = is;
    }

    public boolean isDataAvailable()
    {
      try {
	return _is != null && _is.available() > 0;
      } catch (IOException e) {
	log.log(Level.FINER, e.toString(), e);
	
	return true;
      }
    }

    public boolean startPacket()
      throws IOException
    {
      // skip zero-length packets
      do {
	_isPacketEnd = false;
      } while ((_length = readChunkLength(_is)) == 0);

      return _length > 0;
    }

    public void endPacket()
      throws IOException
    {
      while (! _isPacketEnd) {
	if (_length <= 0)
	  _length = readChunkLength(_is);

	if (_length > 0)
	  _is.skip(_length);
      }
    }

    public int read()
      throws IOException
    {
      if (_isPacketEnd)
	throw new IllegalStateException();
      
      InputStream is = _is;
      
      if (_length == 0) {
	_length = readChunkLength(is);

	if (_length <= 0)
	  return -1;
      }

      _length--;
      
      return is.read();
    }

    public int read(byte []buffer, int offset, int length)
      throws IOException
    {
      if (_isPacketEnd)
	throw new IllegalStateException();
      
      InputStream is = _is;
      
      if (_length <= 0) {
	_length = readChunkLength(is);

	if (_length <= 0)
	  return -1;
      }

      int sublen = _length;
      if (length < sublen)
	sublen = length;

      sublen = is.read(buffer, offset, sublen);

      if (sublen < 0)
	return -1;

      _length -= sublen;

      return sublen;
    }

    private int readChunkLength(InputStream is)
      throws IOException
    {
      if (_isPacketEnd)
	return -1;
      
      int length = 0;
	
      int code = is.read();

      if (code < 0) {
        _isPacketEnd = true;
        return -1;
      }
      else if ((code & 0x80) != 0x80) {
	int len = 256;
	StringBuilder sb = new StringBuilder();
	int ch;
	
	while ((len-- > 0 && is.available() > 0 && (ch = is.read()) >= 0))
	  sb.append((char) ch);
	
        throw new IllegalStateException("WebSocket binary must begin with a 0x80 packet at 0x" + Integer.toHexString(code)
                                        + " ("+ (char) code + ")"
					+ " context[" + sb + "]");
      }

      while ((code = is.read()) >= 0) {
	length = (length << 7) + (code & 0x7f);

	if ((code & 0x80) == 0) {
	  if (length == 0)
	    _isPacketEnd = true;

	  return length;
	}
      }

      _isPacketEnd = true;

      return -1;
    }
  }
}