com.caucho.hessian.mux.MuxInputStream Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of hessian Show documentation
Fork of Hessian by Caucho Technology.
The newest version!
/*
 * 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
 *    [email protected].
 *
 * 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.hessian.mux;

import java.io.IOException;
import java.io.InputStream;

/**
 * Input stream to a specific channel.
 */
public class MuxInputStream extends InputStream {
  private MuxServer server;
  protected InputStream is;
  private int channel;
  
  private String url;
  
  private int chunkLength;

  /**
   * Null argument constructor.
   */
  public MuxInputStream()
  {
  }

  /**
   * Initialize the multiplexor with input and output streams.
   */
  protected void init(MuxServer server, int channel)
    throws IOException
  {
    this.server = server;
    this.channel = channel;

    this.url = null;

    chunkLength = 0;
  }

  /**
   * Gets the raw input stream.  Clients will normally not call
   * this.
   */
  protected InputStream getInputStream()
    throws IOException
  {
    if (is == null && server != null)
      is = server.readChannel(channel);
    
    return is;
  }

  void setInputStream(InputStream is)
  {
    this.is = is;
  }

  /**
   * Gets the channel of the connection.
   */
  public int getChannel()
  {
    return channel;
  }

  /**
   * Returns the request's URL
   */
  public String getURL()
  {
    return url;
  }

  /**
   * Writes a data byte to the output stream.
   */
  public int read()
    throws IOException
  {
    if (chunkLength <= 0) {
      readToData(false);

      if (chunkLength <= 0)
        return -1;
    }
    
    chunkLength--;
    return is.read();
  }

  /**
   * Complete writing to the stream, closing the channel.
   */
  public void close()
    throws IOException
  {
    skipToEnd();
  }

  /**
   * Skips data until the end of the channel.
   */
  private void skipToEnd()
    throws IOException
  {
    InputStream is = getInputStream();
    
    if (is == null)
      return;

    if (chunkLength > 0)
      is.skip(chunkLength);

    for (int tag = is.read(); tag >= 0; tag = is.read()) {
      switch (tag) {
      case 'Y':
        server.freeReadLock();
        this.is = is = server.readChannel(channel);
        if (is == null) {
          this.server = null;
          return;
        }
        break;
        
      case 'Q':
        server.freeReadLock();
        this.is = null;
        this.server = null;
        return;

      case -1:
        server.freeReadLock();
        this.is = null;
        this.server = null;
        return;
        
      default:
        int length = (is.read() << 8) + is.read();
        is.skip(length);
        break;
      }
    }
  }

  /**
   * Reads tags, until getting data.
   */
  void readToData(boolean returnOnYield)
    throws IOException
  {
    InputStream is = getInputStream();
    
    if (is == null)
      return;
    
    for (int tag = is.read(); tag >= 0; tag = is.read()) {
      switch (tag) {
      case 'Y':
        server.freeReadLock();
        if (returnOnYield)
          return;
        server.readChannel(channel);
        break;
        
      case 'Q':
        server.freeReadLock();
        this.is = null;
        this.server = null;
        return;
        
      case 'U':
        this.url = readUTF();
        break;

      case 'D':
        chunkLength = (is.read() << 8) + is.read();
        return;

      default:
        readTag(tag);
        break;
      }
    }
  }

  /**
   * Subclasses will extend this to read values.
   */
  protected void readTag(int tag)
    throws IOException
  {
    int length = (is.read() << 8) + is.read();
    is.skip(length);
  }

  /**
   * Reads a UTF-8 string.
   *
   * @return the utf-8 encoded string
   */
  protected String readUTF()
    throws IOException
  {
    int len = (is.read() << 8) + is.read();

    StringBuffer sb = new StringBuffer();

    while (len > 0) {
      int d1 = is.read();

      if (d1 < 0)
        return sb.toString();
      else if (d1 < 0x80) {
        len--;
        sb.append((char) d1);
      }
      else if ((d1 & 0xe0) == 0xc0) {
        len -= 2;
        sb.append(((d1 & 0x1f) << 6) + (is.read() & 0x3f));
      }
      else if ((d1 & 0xf0) == 0xe0) {
        len -= 3;
        sb.append(((d1 & 0x0f) << 12) +
                  ((is.read() & 0x3f) << 6) +
                  (is.read() & 0x3f));
      }
      else
        throw new IOException("utf-8 encoding error");
    }

    return sb.toString();
  }
}