/*
    * 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;
  
  import io.netty.buffer.ByteBufAllocator;
  import io.netty.util.UniqueName;
  import io.netty.util.internal.PlatformDependent;
  
  import java.net.InetAddress;
  import java.net.NetworkInterface;
  import java.util.concurrent.ConcurrentMap;
  
  import static io.netty.util.internal.ObjectUtil.checkNotNull;
  
  /**
   * A {@link ChannelOption} allows to configure a {@link ChannelConfig} in a type-safe
   * way. Which {@link ChannelOption} is supported depends on the actual implementation
   * of {@link ChannelConfig} and may depend on the nature of the transport it belongs
   * to.
   *
   * @param <T>   the type of the value which is valid for the {@link ChannelOption}
   */
  @SuppressWarnings("deprecation")
  public class ChannelOption<T> extends UniqueName {
  
      @SuppressWarnings("rawtypes")
      private static final ConcurrentMap<String, ChannelOption> names = PlatformDependent.newConcurrentHashMap();
  
      public static final ChannelOption<ByteBufAllocator> ALLOCATOR = valueOf("ALLOCATOR");
      public static final ChannelOption<RecvByteBufAllocator> RCVBUF_ALLOCATOR = valueOf("RCVBUF_ALLOCATOR");
      public static final ChannelOption<MessageSizeEstimator> MESSAGE_SIZE_ESTIMATOR = valueOf("MESSAGE_SIZE_ESTIMATOR");
  
      public static final ChannelOption<Integer> CONNECT_TIMEOUT_MILLIS = valueOf("CONNECT_TIMEOUT_MILLIS");
      public static final ChannelOption<Integer> MAX_MESSAGES_PER_READ = valueOf("MAX_MESSAGES_PER_READ");
      public static final ChannelOption<Integer> WRITE_SPIN_COUNT = valueOf("WRITE_SPIN_COUNT");
      public static final ChannelOption<Integer> WRITE_BUFFER_HIGH_WATER_MARK = valueOf("WRITE_BUFFER_HIGH_WATER_MARK");
      public static final ChannelOption<Integer> WRITE_BUFFER_LOW_WATER_MARK = valueOf("WRITE_BUFFER_LOW_WATER_MARK");
  
      public static final ChannelOption<Boolean> ALLOW_HALF_CLOSURE = valueOf("ALLOW_HALF_CLOSURE");
      public static final ChannelOption<Boolean> AUTO_READ = valueOf("AUTO_READ");
  
      /**
       * @deprecated  Auto close will be removed in a future release.
       *
       * If {@code true} then the {@link Channel} is closed automatically and immediately on write failure.
       * The default value is {@code true}.
       */
      @Deprecated
      public static final ChannelOption<Boolean> AUTO_CLOSE = valueOf("AUTO_CLOSE");
  
      public static final ChannelOption<Boolean> SO_BROADCAST = valueOf("SO_BROADCAST");
      public static final ChannelOption<Boolean> SO_KEEPALIVE = valueOf("SO_KEEPALIVE");
      public static final ChannelOption<Integer> SO_SNDBUF = valueOf("SO_SNDBUF");
      public static final ChannelOption<Integer> SO_RCVBUF = valueOf("SO_RCVBUF");
      public static final ChannelOption<Boolean> SO_REUSEADDR = valueOf("SO_REUSEADDR");
      public static final ChannelOption<Integer> SO_LINGER = valueOf("SO_LINGER");
      public static final ChannelOption<Integer> SO_BACKLOG = valueOf("SO_BACKLOG");
      public static final ChannelOption<Integer> SO_TIMEOUT = valueOf("SO_TIMEOUT");
  
      public static final ChannelOption<Integer> IP_TOS = valueOf("IP_TOS");
      public static final ChannelOption<InetAddress> IP_MULTICAST_ADDR = valueOf("IP_MULTICAST_ADDR");
      public static final ChannelOption<NetworkInterface> IP_MULTICAST_IF = valueOf("IP_MULTICAST_IF");
      public static final ChannelOption<Integer> IP_MULTICAST_TTL = valueOf("IP_MULTICAST_TTL");
      public static final ChannelOption<Boolean> IP_MULTICAST_LOOP_DISABLED = valueOf("IP_MULTICAST_LOOP_DISABLED");
  
      public static final ChannelOption<Boolean> TCP_NODELAY = valueOf("TCP_NODELAY");
  
      @Deprecated
      public static final ChannelOption<Long> AIO_READ_TIMEOUT = valueOf("AIO_READ_TIMEOUT");
      @Deprecated
      public static final ChannelOption<Long> AIO_WRITE_TIMEOUT = valueOf("AIO_WRITE_TIMEOUT");
  
      @Deprecated
      public static final ChannelOption<Boolean> DATAGRAM_CHANNEL_ACTIVE_ON_REGISTRATION =
              valueOf("DATAGRAM_CHANNEL_ACTIVE_ON_REGISTRATION");
  
      public static final ChannelOption<Boolean> SINGLE_EVENTEXECUTOR_PER_GROUP =
              valueOf("SINGLE_EVENTEXECUTOR_PER_GROUP");
  
      /**
       * Creates a new {@link ChannelOption} with the specified {@param name} or return the already existing
       * {@link ChannelOption} for the given name.
       */
      @SuppressWarnings("unchecked")
      public static <T> ChannelOption<T> valueOf(String name) {
          checkNotNull(name, "name");
         ChannelOption<T> option = names.get(name);
         if (option == null) {
             option = new ChannelOption<T>(name);
             ChannelOption<T> old = names.putIfAbsent(name, option);
             if (old != null) {
                 option = old;
             }
         }
         return option;
     }
 
     /**
      * Returns {@code true} if a {@link ChannelOption} exists for the given {@code name}.
      */
     public static boolean exists(String name) {
         checkNotNull(name, "name");
         return names.containsKey(name);
     }
 
     /**
      * Creates a new {@link ChannelOption} for the given {@param name} or fail with an
      * {@link IllegalArgumentException} if a {@link ChannelOption} for the given {@param name} exists.
      */
     @SuppressWarnings("unchecked")
     public static <T> ChannelOption<T> newInstance(String name) {
         checkNotNull(name, "name");
         ChannelOption<T> option = new ChannelOption<T>(name);
         ChannelOption<T> old = names.putIfAbsent(name, option);
         if (old != null) {
             throw new IllegalArgumentException(String.format("'%s' is already in use", name));
         }
         return option;
     }
 
     /**
      * @deprecated Use {@link #valueOf(String)} instead.
      */
     @Deprecated
     protected ChannelOption(String name) {
         super(name);
     }
 
     /**
      * Validate the value which is set for the {@link ChannelOption}. Sub-classes
      * may override this for special checks.
      */
     public void validate(T value) {
         if (value == null) {
             throw new NullPointerException("value");
         }
     }
 }