/*
    * Copyright (c) 2005, The K-Wf Grid Consortium
    * Fraunhofer Institute for Computer Architecture and Software Technology
    * See http://www.kwfgrid.eu and http://www.first.fraunhofer.de for more details.
    */
   package net.kwfgrid.gwes.uiproxy;
   
   import java.util.*;
   
  /**
     Default implementation of buffer. Just a simple FIFO mechanism.
     This buffer supports the following properties:
     <ul>
     <li>Buffer.size</li>
     </ul>
   */
  public class DefaultBuffer extends AbstractBuffer {
      protected List _content;
      protected boolean _overflow;
  
      public DefaultBuffer() {
  	super();
  	_content = new ArrayList(getSize());
  	_overflow = false;
      }
           
      public synchronized void handle(Object message) {
  	if (shouldHandle(message)) {
  	    if (_content.size()>=getSize()) _overflow = true;
  	    else _content.add(message);
  	}
      }
      
      public synchronized Object[] read() throws BufferException {
  	if (_overflow) throw new BufferOverflowException(this);
  	Object[] messages = _content.toArray();
  	_content.clear();
  	return messages;
      }
      
      /**
         Determine if this buffer should handle the specified message.
         The default implementation always returns <code>true</code>. 
         Subclasses must override this method in order to sort out messages of interest.
       */
      protected boolean shouldHandle(Object message) {
  	return true;
      }
  }