/*
    * Copyright 2012 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.local;
  
  import io.netty.channel.Channel;
  import io.netty.channel.ChannelException;
  import io.netty.util.internal.PlatformDependent;
  import io.netty.util.internal.StringUtil;
  
  import java.net.SocketAddress;
  import java.util.concurrent.ConcurrentMap;
  
  final class LocalChannelRegistry {
  
      private static final ConcurrentMap<LocalAddress, Channel> boundChannels = PlatformDependent.newConcurrentHashMap();
  
      static LocalAddress register(
              Channel channel, LocalAddress oldLocalAddress, SocketAddress localAddress) {
          if (oldLocalAddress != null) {
              throw new ChannelException("already bound");
          }
          if (!(localAddress instanceof LocalAddress)) {
              throw new ChannelException("unsupported address type: " + StringUtil.simpleClassName(localAddress));
          }
  
          LocalAddress addr = (LocalAddress) localAddress;
          if (LocalAddress.ANY.equals(addr)) {
              addr = new LocalAddress(channel);
          }
  
          Channel boundChannel = boundChannels.putIfAbsent(addr, channel);
          if (boundChannel != null) {
              throw new ChannelException("address already in use by: " + boundChannel);
          }
          return addr;
      }
  
      static Channel get(SocketAddress localAddress) {
          return boundChannels.get(localAddress);
      }
  
      static void unregister(LocalAddress localAddress) {
          boundChannels.remove(localAddress);
      }
  
      private LocalChannelRegistry() {
          // Unused
      }
  }