/*******************************************************************************
    * Copyright (c) 2011 Intalio, Inc.
    * ======================================================================
    * All rights reserved. This program and the accompanying materials
    * are made available under the terms of the Eclipse Public License v1.0
    * and Apache License v2.0 which accompanies this distribution.
    *
    *   The Eclipse Public License is available at
    *   http://www.eclipse.org/legal/epl-v10.html
   *
   *   The Apache License v2.0 is available at
   *   http://www.opensource.org/licenses/apache2.0.php
   *
   * You may elect to redistribute this code under either of these licenses.
   *******************************************************************************/
  package org.eclipse.jetty.websocket;
  
  import java.io.IOException;
  import java.util.Map;
  
  public class FragmentExtension extends AbstractExtension
  {
      private int _maxLength=-1;
      private int _minFragments=1;
      
      public FragmentExtension()
      {
          super("fragment");
      }
  
      @Override
      public boolean init(Map<String, String> parameters)
      {
          if(super.init(parameters))
          {
              _maxLength=getInitParameter("maxLength",_maxLength);
              _minFragments=getInitParameter("minFragments",_minFragments);
              return true;
          }
          return false;
      }
  
      @Override
      public void addFrame(byte flags, byte opcode, byte[] content, int offset, int length) throws IOException
      {
          if (getConnection().isControl(opcode))
          {
              super.addFrame(flags,opcode,content,offset,length);
              return;
          }
          
          int fragments=1;
          
          while (_maxLength>0 && length>_maxLength)
          {
              fragments++;
              super.addFrame((byte)(flags&~getConnection().finMask()),opcode,content,offset,_maxLength);
              length-=_maxLength;
              offset+=_maxLength;
              opcode=getConnection().continuationOpcode();
          }
          
          while (fragments<_minFragments)
          {
              int frag=length/2;
              fragments++;
              super.addFrame((byte)(flags&0x7),opcode,content,offset,frag);
              length-=frag;
              offset+=frag;
              opcode=getConnection().continuationOpcode();
          }
  
          super.addFrame((byte)(flags|getConnection().finMask()),opcode,content,offset,length);
      }
      
      
  }