/*
    * Copyright 2014 The Netty Project
    *
    * The Netty Project 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 io.netty.channel.epoll;
  
  import io.netty.channel.Channel;
  import io.netty.channel.EventLoop;
  import io.netty.channel.socket.ServerSocketChannel;
  import io.netty.channel.unix.FileDescriptor;
  import io.netty.channel.unix.Socket;
  
  import java.io.IOException;
  import java.net.InetAddress;
  import java.net.InetSocketAddress;
  import java.net.SocketAddress;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.Map;
  
  import static io.netty.channel.unix.NativeInetAddress.address;
  import static io.netty.channel.unix.Socket.newSocketStream;
  
  /**
   * {@link ServerSocketChannel} implementation that uses linux EPOLL Edge-Triggered Mode for
   * maximal performance.
   */
  public final class EpollServerSocketChannel extends AbstractEpollServerChannel implements ServerSocketChannel {
  
      private final EpollServerSocketChannelConfig config;
      private volatile Collection<InetAddress> tcpMd5SigAddresses = Collections.emptyList();
  
      public EpollServerSocketChannel() {
          super(newSocketStream(), false);
          config = new EpollServerSocketChannelConfig(this);
      }
  
      /**
       * @deprecated Use {@link #EpollServerSocketChannel(Socket, boolean)}.
       * Creates a new {@link EpollServerSocketChannel} from an existing {@link FileDescriptor}.
       */
      @Deprecated
      public EpollServerSocketChannel(FileDescriptor fd) {
          // Must call this constructor to ensure this object's local address is configured correctly.
          // The local address can only be obtained from a Socket object.
          this(new Socket(fd.intValue()));
      }
  
      /**
       * @deprecated Use {@link #EpollServerSocketChannel(Socket, boolean)}.
       * Creates a new {@link EpollServerSocketChannel} from an existing {@link Socket}.
       */
      @Deprecated
      public EpollServerSocketChannel(Socket fd) {
          super(fd);
          config = new EpollServerSocketChannelConfig(this);
      }
  
      public EpollServerSocketChannel(Socket fd, boolean active) {
          super(fd, active);
          config = new EpollServerSocketChannelConfig(this);
      }
  
      @Override
      protected boolean isCompatible(EventLoop loop) {
          return loop instanceof EpollEventLoop;
      }
  
      @Override
      protected void doBind(SocketAddress localAddress) throws Exception {
          super.doBind(localAddress);
          if (Native.IS_SUPPORTING_TCP_FASTOPEN && config.getTcpFastopen() > 0) {
              Native.setTcpFastopen(fd().intValue(), config.getTcpFastopen());
          }
          fd().listen(config.getBacklog());
          active = true;
      }
  
      @Override
      public InetSocketAddress remoteAddress() {
          return (InetSocketAddress) super.remoteAddress();
      }
  
      @Override
      public InetSocketAddress localAddress() {
          return (InetSocketAddress) super.localAddress();
      }
  
     @Override
     public EpollServerSocketChannelConfig config() {
         return config;
     }
 
     @Override
     protected Channel newChildChannel(int fd, byte[] address, int offset, int len) throws Exception {
         return new EpollSocketChannel(this, new Socket(fd), address(address, offset, len));
     }
 
     Collection<InetAddress> tcpMd5SigAddresses() {
         return tcpMd5SigAddresses;
     }
 
     void setTcpMd5Sig(Map<InetAddress, byte[]> keys) throws IOException {
         tcpMd5SigAddresses = TcpMd5Util.newTcpMd5Sigs(this, tcpMd5SigAddresses, keys);
     }
 }