//
   //  ========================================================================
   //  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.server;
  
  import java.io.IOException;
  import java.net.InetSocketAddress;
  import java.net.ServerSocket;
  import java.net.Socket;
  import java.net.SocketException;
  import java.nio.channels.Channel;
  import java.nio.channels.SelectionKey;
  import java.nio.channels.Selector;
  import java.nio.channels.ServerSocketChannel;
  import java.nio.channels.SocketChannel;
  import java.util.concurrent.Executor;
  import java.util.concurrent.Future;
  
  import org.eclipse.jetty.io.ByteBufferPool;
  import org.eclipse.jetty.io.Connection;
  import org.eclipse.jetty.io.EndPoint;
  import org.eclipse.jetty.io.SelectChannelEndPoint;
  import org.eclipse.jetty.io.SelectorManager;
  import org.eclipse.jetty.io.SelectorManager.ManagedSelector;
  import org.eclipse.jetty.util.Callback;
  import org.eclipse.jetty.util.annotation.ManagedAttribute;
  import org.eclipse.jetty.util.annotation.ManagedObject;
  import org.eclipse.jetty.util.annotation.Name;
  import org.eclipse.jetty.util.ssl.SslContextFactory;
  import org.eclipse.jetty.util.thread.Scheduler;
  
  /**
   * This {@link Connector} implementation is the primary connector for the
   * Jetty server over TCP/IP.  By the use of various {@link ConnectionFactory} instances it is able
   * to accept connections for HTTP, SPDY and WebSocket, either directly or over SSL.
   * <p>
   * The connector is a fully asynchronous NIO based implementation that by default will
   * use all the commons services (eg {@link Executor}, {@link Scheduler})  of the
   * passed {@link Server} instance, but all services may also be constructor injected
   * into the connector so that it may operate with dedicated or otherwise shared services.
   * <p>
   * <h2>Connection Factories</h2>
   * Various convenience constructors are provided to assist with common configurations of
   * ConnectionFactories, whose generic use is described in {@link AbstractConnector}.
   * If no connection factories are passed, then the connector will
   * default to use a {@link HttpConnectionFactory}.  If an non null {@link SslContextFactory}
   * instance is passed, then this used to instantiate a {@link SslConnectionFactory} which is
   * prepended to the other passed or default factories.
   * <p>
   * <h2>Selectors</h2>
   * The connector will use the {@link Executor} service to execute a number of Selector Tasks,
   * which are implemented to each use a NIO {@link Selector} instance to asynchronously
   * schedule a set of accepted connections.  It is the selector thread that will call the
   * {@link Callback} instances passed in the {@link EndPoint#fillInterested(Callback)} or
   * {@link EndPoint#write(Object, Callback, java.nio.ByteBuffer...)} methods.  It is expected
   * that these callbacks may do some non-blocking IO work, but will always dispatch to the
   * {@link Executor} service any blocking, long running or application tasks.
   * <p>
   * The default number of selectors is equal to the number of processors available to the JVM,
   * which should allow optimal performance even if all the connections used are performing
   * significant non-blocking work in the callback tasks.
   *
   */
  @ManagedObject("HTTP connector using NIO ByteChannels and Selectors")
  public class ServerConnector extends AbstractNetworkConnector
  {
      private final SelectorManager _manager;
      private volatile ServerSocketChannel _acceptChannel;
      private volatile boolean _inheritChannel = false;
      private volatile int _localPort = -1;
      private volatile int _acceptQueueSize = 0;
      private volatile boolean _reuseAddress = true;
      private volatile int _lingerTime = -1;
  
  
      /* ------------------------------------------------------------ */
      /** HTTP Server Connection.
       * <p>Construct a ServerConnector with a private instance of {@link HttpConnectionFactory} as the only factory.</p>
       * @param server The {@link Server} this connector will accept connection for. 
       */
      public ServerConnector(
          @Name("server") Server server)
      {
          this(server,null,null,null,0,0,new HttpConnectionFactory());
     }
 
     /* ------------------------------------------------------------ */
     /** Generic Server Connection with default configuration.
      * <p>Construct a Server Connector with the passed Connection factories.</p>
      * @param server The {@link Server} this connector will accept connection for. 
      * @param factories Zero or more {@link ConnectionFactory} instances used to create and configure connections.
      */
     public ServerConnector(
         @Name("server") Server server,
         @Name("factories") ConnectionFactory... factories)
     {
         this(server,null,null,null,0,0,factories);
     }
 
     /* ------------------------------------------------------------ */
     /** HTTP Server Connection.
      * <p>Construct a ServerConnector with a private instance of {@link HttpConnectionFactory} as the primary protocol</p>.
      * @param server The {@link Server} this connector will accept connection for. 
      * @param sslContextFactory If non null, then a {@link SslConnectionFactory} is instantiated and prepended to the 
      * list of HTTP Connection Factory.
      */
     public ServerConnector(
         @Name("server") Server server,
         @Name("sslContextFactory") SslContextFactory sslContextFactory)
     {
         this(server,null,null,null,0,0,AbstractConnectionFactory.getFactories(sslContextFactory,new HttpConnectionFactory()));
     }
 
     /* ------------------------------------------------------------ */
     /** Generic SSL Server Connection.
      * @param server The {@link Server} this connector will accept connection for. 
      * @param sslContextFactory If non null, then a {@link SslConnectionFactory} is instantiated and prepended to the 
      * list of ConnectionFactories, with the first factory being the default protocol for the SslConnectionFactory.
      * @param factories Zero or more {@link ConnectionFactory} instances used to create and configure connections.
      */
     public ServerConnector(
         @Name("server") Server server,
         @Name("sslContextFactory") SslContextFactory sslContextFactory,
         @Name("factories") ConnectionFactory... factories)
     {
         this(server,null,null,null,0,0,AbstractConnectionFactory.getFactories(sslContextFactory,factories));
     }
 
     /** Generic Server Connection.
      * @param server    
      *          The server this connector will be accept connection for.  
      * @param executor  
      *          An executor used to run tasks for handling requests, acceptors and selectors. I
      *          If null then use the servers executor
      * @param scheduler 
      *          A scheduler used to schedule timeouts. If null then use the servers scheduler
      * @param bufferPool
      *          A ByteBuffer pool used to allocate buffers.  If null then create a private pool with default configuration.
      * @param acceptors 
      *          the number of acceptor threads to use, or 0 for a default value. Acceptors accept new TCP/IP connections.
      * @param selectors
      *          the number of selector threads, or 0 for a default value. Selectors notice and schedule established connection that can make IO progress.
      * @param factories 
      *          Zero or more {@link ConnectionFactory} instances used to create and configure connections.
      */
     public ServerConnector(
         @Name("server") Server server,
         @Name("executor") Executor executor,
         @Name("scheduler") Scheduler scheduler,
         @Name("bufferPool") ByteBufferPool bufferPool,
         @Name("acceptors") int acceptors,
         @Name("selectors") int selectors,
         @Name("factories") ConnectionFactory... factories)
     {
         super(server,executor,scheduler,bufferPool,acceptors,factories);
         _manager = new ServerConnectorManager(getExecutor(), getScheduler(), selectors > 0 ? selectors : Runtime.getRuntime().availableProcessors());
         addBean(_manager, true);
     }
 
     @Override
     public boolean isOpen()
     {
         ServerSocketChannel channel = _acceptChannel;
         return channel!=null && channel.isOpen();
     }
 
     /**
      * @return whether this connector uses a channel inherited from the JVM.
      * @see System#inheritedChannel()
      */
     public boolean isInheritChannel()
     {
         return _inheritChannel;
     }
 
     /**
      * <p>Sets whether this connector uses a channel inherited from the JVM.</p>
      * <p>If true, the connector first tries to inherit from a channel provided by the system.
      * If there is no inherited channel available, or if the inherited channel is not usable,
      * then it will fall back using {@link ServerSocketChannel}.</p>
      * <p>Use it with xinetd/inetd, to launch an instance of Jetty on demand. The port
      * used to access pages on the Jetty instance is the same as the port used to
      * launch Jetty.</p>
      *
      * @param inheritChannel whether this connector uses a channel inherited from the JVM.
      */
     public void setInheritChannel(boolean inheritChannel)
     {
         _inheritChannel = inheritChannel;
     }
 
     @Override
     public void open() throws IOException
     {
         if (_acceptChannel == null)
         {
             ServerSocketChannel serverChannel = null;
             if (isInheritChannel())
             {
                 Channel channel = System.inheritedChannel();
                 if (channel instanceof ServerSocketChannel)
                     serverChannel = (ServerSocketChannel)channel;
                 else
                     LOG.warn("Unable to use System.inheritedChannel() [{}]. Trying a new ServerSocketChannel at {}:{}", channel, getHost(), getPort());
             }
 
             if (serverChannel == null)
             {
                 serverChannel = ServerSocketChannel.open();
 
                 InetSocketAddress bindAddress = getHost() == null ? new InetSocketAddress(getPort()) : new InetSocketAddress(getHost(), getPort());
                 serverChannel.socket().bind(bindAddress, getAcceptQueueSize());
                 serverChannel.socket().setReuseAddress(getReuseAddress());
 
                 _localPort = serverChannel.socket().getLocalPort();
                 if (_localPort <= 0)
                     throw new IOException("Server channel not bound");
 
                 addBean(serverChannel);
             }
 
             serverChannel.configureBlocking(true);
             addBean(serverChannel);
 
             _acceptChannel = serverChannel;
         }
     }
 
     @Override
     public Future<Void> shutdown()
     {
         // TODO shutdown all the connections
         return super.shutdown();
     }
 
     @Override
     public void close()
     {
         ServerSocketChannel serverChannel = _acceptChannel;
         _acceptChannel = null;
 
         if (serverChannel != null)
         {
             removeBean(serverChannel);
 
             // If the interrupt did not close it, we should close it
             if (serverChannel.isOpen())
             {
                 try
                 {
                     serverChannel.close();
                 }
                 catch (IOException e)
                 {
                     LOG.warn(e);
                 }
             }
         }
         // super.close();
         _localPort = -2;
     }
 
     @Override
     public void accept(int acceptorID) throws IOException
     {
         ServerSocketChannel serverChannel = _acceptChannel;
         if (serverChannel != null && serverChannel.isOpen())
         {
             SocketChannel channel = serverChannel.accept();
             channel.configureBlocking(false);
             Socket socket = channel.socket();
             configure(socket);
             _manager.accept(channel);
         }
     }
 
     protected void configure(Socket socket)
     {
         try
         {
             socket.setTcpNoDelay(true);
             if (_lingerTime >= 0)
                 socket.setSoLinger(true, _lingerTime / 1000);
             else
                 socket.setSoLinger(false, 0);
         }
         catch (SocketException e)
         {
             LOG.ignore(e);
         }
     }
 
     public SelectorManager getSelectorManager()
     {
         return _manager;
     }
 
     @Override
     public Object getTransport()
     {
         return _acceptChannel;
     }
 
     @Override
     @ManagedAttribute("local port")
     public int getLocalPort()
     {
         return _localPort;
     }
 
     protected SelectChannelEndPoint newEndPoint(SocketChannel channel, ManagedSelector selectSet, SelectionKey key) throws IOException
     {
         return new SelectChannelEndPoint(channel, selectSet, key, getScheduler(), getIdleTimeout());
     }
 
     /**
      * @return the linger time
      * @see Socket#getSoLinger()
      */
     @ManagedAttribute("TCP/IP solinger time or -1 to disable")
     public int getSoLingerTime()
     {
         return _lingerTime;
     }
 
     /**
      * @param lingerTime the linger time. Use -1 to disable.
      * @see Socket#setSoLinger(boolean, int)
      */
     public void setSoLingerTime(int lingerTime)
     {
         _lingerTime = lingerTime;
     }
 
     /**
      * @return the accept queue size
      */
     @ManagedAttribute("Accept Queue size")
     public int getAcceptQueueSize()
     {
         return _acceptQueueSize;
     }
 
     /**
      * @param acceptQueueSize the accept queue size (also known as accept backlog)
      */
     public void setAcceptQueueSize(int acceptQueueSize)
     {
         _acceptQueueSize = acceptQueueSize;
     }
 
     /**
      * @return whether the server socket reuses addresses
      * @see ServerSocket#getReuseAddress()
      */
     public boolean getReuseAddress()
     {
         return _reuseAddress;
     }
 
     /**
      * @param reuseAddress whether the server socket reuses addresses
      * @see ServerSocket#setReuseAddress(boolean)
      */
     public void setReuseAddress(boolean reuseAddress)
     {
         _reuseAddress = reuseAddress;
     }
 
     private final class ServerConnectorManager extends SelectorManager
     {
         private ServerConnectorManager(Executor executor, Scheduler scheduler, int selectors)
         {
             super(executor, scheduler, selectors);
         }
 
         @Override
         protected SelectChannelEndPoint newEndPoint(SocketChannel channel, ManagedSelector selectSet, SelectionKey selectionKey) throws IOException
         {
             return ServerConnector.this.newEndPoint(channel, selectSet, selectionKey);
         }
 
         @Override
         public Connection newConnection(SocketChannel channel, EndPoint endpoint, Object attachment) throws IOException
         {
             return getDefaultConnectionFactory().newConnection(ServerConnector.this, endpoint);
         }
     }
 }