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   /*
    * 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:
    *
    *   https://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.util.concurrent.AbstractFuture;
  import io.netty.util.concurrent.Future;
  import io.netty.util.concurrent.GenericFutureListener;
  import io.netty.util.internal.ObjectUtil;
  import io.netty.util.internal.UnstableApi;
  
  import java.util.concurrent.TimeUnit;
  
  @UnstableApi
  public final class VoidChannelPromise extends AbstractFuture<Void> implements ChannelPromise {
  
      private final Channel channel;
      // Will be null if we should not propagate exceptions through the pipeline on failure case.
      private final ChannelFutureListener fireExceptionListener;
  
      /**
       * Creates a new instance.
       *
       * @param channel the {@link Channel} associated with this future
       */
      public VoidChannelPromise(final Channel channel, boolean fireException) {
          ObjectUtil.checkNotNull(channel, "channel");
          this.channel = channel;
          if (fireException) {
              fireExceptionListener = new ChannelFutureListener() {
                  @Override
                  public void operationComplete(ChannelFuture future) throws Exception {
                      Throwable cause = future.cause();
                      if (cause != null) {
                          fireException0(cause);
                      }
                  }
              };
          } else {
              fireExceptionListener = null;
          }
      }
  
      @Override
      public VoidChannelPromise addListener(GenericFutureListener<? extends Future<? super Void>> listener) {
          fail();
          return this;
      }
  
      @Override
      public VoidChannelPromise addListeners(GenericFutureListener<? extends Future<? super Void>>... listeners) {
          fail();
          return this;
      }
  
      @Override
      public VoidChannelPromise removeListener(GenericFutureListener<? extends Future<? super Void>> listener) {
          // NOOP
          return this;
      }
  
      @Override
      public VoidChannelPromise removeListeners(GenericFutureListener<? extends Future<? super Void>>... listeners) {
          // NOOP
          return this;
      }
  
      @Override
      public VoidChannelPromise await() throws InterruptedException {
          if (Thread.interrupted()) {
              throw new InterruptedException();
          }
          return this;
      }
  
      @Override
      public boolean await(long timeout, TimeUnit unit) {
          fail();
          return false;
      }
  
      @Override
      public boolean await(long timeoutMillis) {
          fail();
          return false;
      }
  
     @Override
     public VoidChannelPromise awaitUninterruptibly() {
         fail();
         return this;
     }
 
     @Override
     public boolean awaitUninterruptibly(long timeout, TimeUnit unit) {
         fail();
         return false;
     }
 
     @Override
     public boolean awaitUninterruptibly(long timeoutMillis) {
         fail();
         return false;
     }
 
     @Override
     public Channel channel() {
         return channel;
     }
 
     @Override
     public boolean isDone() {
         return false;
     }
 
     @Override
     public boolean isSuccess() {
         return false;
     }
 
     @Override
     public boolean setUncancellable() {
         return true;
     }
 
     @Override
     public boolean isCancellable() {
         return false;
     }
 
     @Override
     public boolean isCancelled() {
         return false;
     }
 
     @Override
     public Throwable cause() {
         return null;
     }
 
     @Override
     public VoidChannelPromise sync() {
         fail();
         return this;
     }
 
     @Override
     public VoidChannelPromise syncUninterruptibly() {
         fail();
         return this;
     }
 
     @Override
     public VoidChannelPromise setFailure(Throwable cause) {
         fireException0(cause);
         return this;
     }
 
     @Override
     public VoidChannelPromise setSuccess() {
         return this;
     }
 
     @Override
     public boolean tryFailure(Throwable cause) {
         fireException0(cause);
         return false;
     }
 
     /**
      * {@inheritDoc}
      *
      * @param mayInterruptIfRunning this value has no effect in this implementation.
      */
     @Override
     public boolean cancel(boolean mayInterruptIfRunning) {
         return false;
     }
 
     @Override
     public boolean trySuccess() {
         return false;
     }
 
     private static void fail() {
         throw new IllegalStateException("void future");
     }
 
     @Override
     public VoidChannelPromise setSuccess(Void result) {
         return this;
     }
 
     @Override
     public boolean trySuccess(Void result) {
         return false;
     }
 
     @Override
     public Void getNow() {
         return null;
     }
 
     @Override
     public ChannelPromise unvoid() {
         ChannelPromise promise = new DefaultChannelPromise(channel);
         if (fireExceptionListener != null) {
             promise.addListener(fireExceptionListener);
         }
         return promise;
     }
 
     @Override
     public boolean isVoid() {
         return true;
     }
 
     private void fireException0(Throwable cause) {
         // Only fire the exception if the channel is open and registered
         // if not the pipeline is not setup and so it would hit the tail
         // of the pipeline.
         // See https://github.com/netty/netty/issues/1517
         if (fireExceptionListener != null && channel.isRegistered()) {
             channel.pipeline().fireExceptionCaught(cause);
         }
     }
 }