content: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You under the Apache License, Version 2.0
   * (the "License"); you may not use this file except in compliance with
   * the License.  You may obtain a copy of the License at
   *
   *    http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package org.apache.spark.network.netty;
  
  import java.net.InetSocketAddress;
  
  import io.netty.bootstrap.ServerBootstrap;
  import io.netty.channel.ChannelFuture;
  import io.netty.channel.ChannelOption;
  import io.netty.channel.EventLoopGroup;
  import io.netty.channel.oio.OioEventLoopGroup;
  import io.netty.channel.socket.oio.OioServerSocketChannel;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * Server that accept the path of a file an echo back its content.
   */
  class FileServer {
  
    private static final Logger LOG = LoggerFactory.getLogger(FileServer.class.getName());
  
    private EventLoopGroup bossGroup = null;
    private EventLoopGroup workerGroup = null;
    private ChannelFuture channelFuture = null;
    private int port = 0;
  
    FileServer(PathResolver pResolver, int port) {
      InetSocketAddress addr = new InetSocketAddress(port);
  
      // Configure the server.
      bossGroup = new OioEventLoopGroup();
      workerGroup = new OioEventLoopGroup();
  
      ServerBootstrap bootstrap = new ServerBootstrap();
      bootstrap.group(bossGroup, workerGroup)
          .channel(OioServerSocketChannel.class)
          .option(ChannelOption.SO_BACKLOG, 100)
          .option(ChannelOption.SO_RCVBUF, 1500)
          .childHandler(new FileServerChannelInitializer(pResolver));
      // Start the server.
      channelFuture = bootstrap.bind(addr);
      try {
        // Get the address we bound to.
        InetSocketAddress boundAddress =
          ((InetSocketAddress) channelFuture.sync().channel().localAddress());
        this.port = boundAddress.getPort();
      } catch (InterruptedException ie) {
        this.port = 0;
      }
    }
  
    /**
     * Start the file server asynchronously in a new thread.
     */
    public void start() {
      Thread blockingThread = new Thread() {
        @Override
        public void run() {
          try {
            channelFuture.channel().closeFuture().sync();
            LOG.info("FileServer exiting");
          } catch (InterruptedException e) {
            LOG.error("File server start got interrupted", e);
          }
          // NOTE: bootstrap is shutdown in stop()
        }
      };
      blockingThread.setDaemon(true);
      blockingThread.start();
    }
  
    public int getPort() {
      return port;
    }
  
    public void stop() {
      // Close the bound channel.
      if (channelFuture != null) {
        channelFuture.channel().close().awaitUninterruptibly();
        channelFuture = null;
      }
  
      // Shutdown event groups
      if (bossGroup != null) {
         bossGroup.shutdownGracefully();
         bossGroup = null;
      }
  
      if (workerGroup != null) {
         workerGroup.shutdownGracefully();
         workerGroup = null;
      }
      // TODO: Shutdown all accepted channels as well ?
    }
  }
  