//
   //  ========================================================================
   //  Copyright (c) 1995-2013 Mort Bay Consulting Pty. Ltd.
   //  ------------------------------------------------------------------------
   //  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.common.message;
  
  import java.io.IOException;
  import java.io.Reader;
  import java.nio.ByteBuffer;
  
  import org.eclipse.jetty.util.Utf8StringBuilder;
  import org.eclipse.jetty.websocket.common.events.AnnotatedEventDriver;
  
  /**
   * Support class for reading text message data as an Reader.
   * <p>
   * Due to the spec, this reader is forced to use the UTF8 charset.
   */
  public class MessageReader extends Reader implements MessageAppender
  {
      private final AnnotatedEventDriver driver;
      private final Utf8StringBuilder utf;
      private int size;
      private boolean finished;
      private boolean needsNotification;
  
      public MessageReader(AnnotatedEventDriver driver)
      {
          this.driver = driver;
          this.utf = new Utf8StringBuilder();
          size = 0;
          finished = false;
          needsNotification = true;
      }
  
      @Override
      public void appendMessage(ByteBuffer payload) throws IOException
      {
          if (finished)
          {
              throw new IOException("Cannot append to finished buffer");
          }
  
          if (payload == null)
          {
              // empty payload is valid
              return;
          }
  
          driver.getPolicy().assertValidMessageSize(size + payload.remaining());
          size += payload.remaining();
  
          synchronized (utf)
          {
              utf.append(payload);
          }
  
          if (needsNotification)
          {
              needsNotification = true;
              this.driver.onReader(this);
          }
      }
  
      @Override
      public void close() throws IOException
      {
          finished = true;
      }
  
      @Override
      public void messageComplete()
      {
          finished = true;
      }
  
      @Override
      public int read(char[] cbuf, int off, int len) throws IOException
      {
          // TODO Auto-generated method stub
          return 0;
      }
  }