/*
 * Copyright (C) 2011 The Guava Authors
 *
 * Licensed 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 com.google.common.util.concurrent;

import com.google.common.annotations.GwtIncompatible;
import com.google.common.collect.ForwardingObject;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.util.Collection;
import java.util.List;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;

An executor service which forwards all its method calls to another executor service. Subclasses
should override one or more methods to modify the behavior of the backing executor service as
desired per the decorator pattern.
Author:
Kurt Alfred Kluever
Since:
10.0/**
 * An executor service which forwards all its method calls to another executor service. Subclasses
 * should override one or more methods to modify the behavior of the backing executor service as
 * desired per the <a href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
 *
 * @author Kurt Alfred Kluever
 * @since 10.0
 */
@CanIgnoreReturnValue // TODO(cpovirk): Consider being more strict.
@GwtIncompatible
public abstract class ForwardingExecutorService extends ForwardingObject
    implements ExecutorService {
  
Constructor for use by subclasses. /** Constructor for use by subclasses. */
  protected ForwardingExecutorService() {}

  @Override
  protected abstract ExecutorService delegate();

  @Override
  public boolean awaitTermination(long timeout, TimeUnit unit) throws InterruptedException {
    return delegate().awaitTermination(timeout, unit);
  }

  @Override
  public <T> List<Future<T>> invokeAll(Collection<? extends Callable<T>> tasks)
      throws InterruptedException {
    return delegate().invokeAll(tasks);
  }

  @Override
  public <T> List<Future<T>> invokeAll(
      Collection<? extends Callable<T>> tasks, long timeout, TimeUnit unit)
      throws InterruptedException {
    return delegate().invokeAll(tasks, timeout, unit);
  }

  @Override
  public <T> T invokeAny(Collection<? extends Callable<T>> tasks)
      throws InterruptedException, ExecutionException {
    return delegate().invokeAny(tasks);
  }

  @Override
  public <T> T invokeAny(Collection<? extends Callable<T>> tasks, long timeout, TimeUnit unit)
      throws InterruptedException, ExecutionException, TimeoutException {
    return delegate().invokeAny(tasks, timeout, unit);
  }

  @Override
  public boolean isShutdown() {
    return delegate().isShutdown();
  }

  @Override
  public boolean isTerminated() {
    return delegate().isTerminated();
  }

  @Override
  public void shutdown() {
    delegate().shutdown();
  }

  @Override
  public List<Runnable> shutdownNow() {
    return delegate().shutdownNow();
  }

  @Override
  public void execute(Runnable command) {
    delegate().execute(command);
  }

  public <T> Future<T> submit(Callable<T> task) {
    return delegate().submit(task);
  }

  @Override
  public Future<?> submit(Runnable task) {
    return delegate().submit(task);
  }

  @Override
  public <T> Future<T> submit(Runnable task, T result) {
    return delegate().submit(task, result);
  }
}