/*
* Copyright (C) 2012 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.collect;
import java.util.
Collection;
import java.util.concurrent.
BlockingDeque;
import java.util.concurrent.
TimeUnit;
/**
* A {@link BlockingDeque} which forwards all its method calls to another {@code BlockingDeque}.
* Subclasses should override one or more methods to modify the behavior of the backing deque as
* desired per the <a href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
*
* <p><b>Warning:</b> The methods of {@code ForwardingBlockingDeque} forward
* <b>indiscriminately</b> to the methods of the delegate. For example, overriding {@link #add}
* alone <b>will not</b> change the behaviour of {@link #offer} which can lead to unexpected
* behaviour. In this case, you should override {@code offer} as well, either providing your own
* implementation, or delegating to the provided {@code standardOffer} method.
*
* <p>
* The {@code standard} methods are not guaranteed to be thread-safe, even when all of the methods
* that they depend on are thread-safe.
*
* @author Emily Soldal
* @since 14.0
*/
public abstract class
ForwardingBlockingDeque<E>
extends
ForwardingDeque<E> implements
BlockingDeque<E> {
/** Constructor for use by subclasses. */
protected
ForwardingBlockingDeque() {}
@
Override protected abstract
BlockingDeque<E>
delegate();
@
Override
public int
remainingCapacity() {
return
delegate().
remainingCapacity();
}
@
Override
public void
putFirst(E
e) throws
InterruptedException {
delegate().
putFirst(
e);
}
@
Override
public void
putLast(E
e) throws
InterruptedException {
delegate().
putLast(
e);
}
@
Override
public boolean
offerFirst(E
e, long
timeout,
TimeUnit unit) throws
InterruptedException {
return
delegate().
offerFirst(
e,
timeout,
unit);
}
@
Override
public boolean
offerLast(E
e, long
timeout,
TimeUnit unit) throws
InterruptedException {
return
delegate().
offerLast(
e,
timeout,
unit);
}
@
Override
public E
takeFirst() throws
InterruptedException {
return
delegate().
takeFirst();
}
@
Override
public E
takeLast() throws
InterruptedException {
return
delegate().
takeLast();
}
@
Override
public E
pollFirst(long
timeout,
TimeUnit unit) throws
InterruptedException {
return
delegate().
pollFirst(
timeout,
unit);
}
@
Override
public E
pollLast(long
timeout,
TimeUnit unit) throws
InterruptedException {
return
delegate().
pollLast(
timeout,
unit);
}
@
Override
public void
put(E
e) throws
InterruptedException {
delegate().
put(
e);
}
@
Override
public boolean
offer(E
e, long
timeout,
TimeUnit unit) throws
InterruptedException {
return
delegate().
offer(
e,
timeout,
unit);
}
@
Override
public E
take() throws
InterruptedException {
return
delegate().
take();
}
@
Override
public E
poll(long
timeout,
TimeUnit unit) throws
InterruptedException {
return
delegate().
poll(
timeout,
unit);
}
@
Override
public int
drainTo(
Collection<? super E>
c) {
return
delegate().
drainTo(
c);
}
@
Override
public int
drainTo(
Collection<? super E>
c, int
maxElements) {
return
delegate().
drainTo(
c,
maxElements);
}
}