//
   //  ========================================================================
   //  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.spdy.client;
  
  import java.io.IOException;
  import java.nio.ByteBuffer;
  import java.util.concurrent.Executor;
  
  import org.eclipse.jetty.io.AbstractConnection;
  import org.eclipse.jetty.io.ByteBufferPool;
  import org.eclipse.jetty.io.EndPoint;
  import org.eclipse.jetty.io.RuntimeIOException;
  import org.eclipse.jetty.spdy.Controller;
  import org.eclipse.jetty.spdy.ISession;
  import org.eclipse.jetty.spdy.IdleListener;
  import org.eclipse.jetty.spdy.api.GoAwayInfo;
  import org.eclipse.jetty.spdy.parser.Parser;
  import org.eclipse.jetty.util.Callback;
  import org.eclipse.jetty.util.log.Log;
  import org.eclipse.jetty.util.log.Logger;
  
  public class SPDYConnection extends AbstractConnection implements Controller, IdleListener
  {
      private static final Logger LOG = Log.getLogger(SPDYConnection.class);
      private final ByteBufferPool bufferPool;
      private final Parser parser;
      private final int bufferSize;
      private volatile ISession session;
      private volatile boolean idle = false;
  
      public SPDYConnection(EndPoint endPoint, ByteBufferPool bufferPool, Parser parser, Executor executor,
                            boolean executeOnFillable)
      {
          this(endPoint, bufferPool, parser, executor, executeOnFillable, 8192);
      }
  
      public SPDYConnection(EndPoint endPoint, ByteBufferPool bufferPool, Parser parser, Executor executor,
                            boolean executeOnFillable, int bufferSize)
      {
          // Since SPDY is multiplexed, onFillable() must never block while calling application code. In fact,
          // the SPDY code always dispatches to a new thread when calling application code,
          // so here we can safely pass false as last parameter, and avoid to dispatch to onFillable(). The IO
          // operation (read, parse, etc.) will not block and will be fast in almost all cases. Big uploads to a server
          // however might block the Selector thread for a long time and therefore block other connections to be read.
          // This might be a good reason to set executeOnFillable to true.
          //
          // Due to a jvm bug we've had a Selector thread being stuck at
          // sun.nio.ch.FileDispatcherImpl.preClose0(Native Method). That's why we now default executeOnFillable to
          // true even if for most use cases it is faster to not dispatch the IO events.
          super(endPoint, executor, executeOnFillable);
          this.bufferPool = bufferPool;
          this.parser = parser;
          onIdle(true);
          this.bufferSize = bufferSize;
      }
  
      @Override
      public void onOpen()
      {
          super.onOpen();
          fillInterested();
      }
  
      @Override
      public void onFillable()
      {
          ByteBuffer buffer = bufferPool.acquire(bufferSize, false);
          boolean readMore = read(buffer) == 0;
          bufferPool.release(buffer);
          if (readMore)
              fillInterested();
      }
  
      protected int read(ByteBuffer buffer)
      {
          EndPoint endPoint = getEndPoint();
          while (true)
          {
              int filled = fill(endPoint, buffer);
              LOG.debug("Read {} bytes", filled);
              if (filled == 0)
              {
                  return 0;
             }
             else if (filled < 0)
             {
                 shutdown(session);
                 return -1;
             }
             else
             {
                 parser.parse(buffer);
             }
         }
     }
 
     private int fill(EndPoint endPoint, ByteBuffer buffer)
     {
         try
         {
             if (endPoint.isInputShutdown())
                 return -1;
             return endPoint.fill(buffer);
         }
         catch (IOException x)
         {
             endPoint.close();
             throw new RuntimeIOException(x);
         }
     }
 
     @Override
     public void write(ByteBuffer buffer, final Callback callback)
     {
         EndPoint endPoint = getEndPoint();
         endPoint.write(callback, buffer);
     }
 
     @Override
     public void close()
     {
         goAway(session);
     }
 
     @Override
     public void close(boolean onlyOutput)
     {
         EndPoint endPoint = getEndPoint();
         // We need to gently close first, to allow
         // SSL close alerts to be sent by Jetty
         LOG.debug("Shutting down output {}", endPoint);
         endPoint.shutdownOutput();
         if (!onlyOutput)
         {
             LOG.debug("Closing {}", endPoint);
             endPoint.close();
         }
     }
 
     @Override
     public void onIdle(boolean idle)
     {
         this.idle = idle;
     }
 
     @Override
     protected boolean onReadTimeout()
     {
         boolean idle = this.idle;
         LOG.debug("Idle timeout on {}, idle={}", this, idle);
         if (idle)
             goAway(session);
         return false;
     }
 
     protected void goAway(ISession session)
     {
         if (session != null)
             session.goAway(new GoAwayInfo(), new Callback.Adapter());
     }
 
     private void shutdown(ISession session)
     {
         if (session != null && !getEndPoint().isOutputShutdown())
             session.shutdown();
     }
 
     protected ISession getSession()
     {
         return session;
     }
 
     public void setSession(ISession session)
     {
         this.session = session;
     }
 }