netty5/transport/src/main/java/io/netty/channel/DefaultChannelPromise.java
Norman Maurer 217fb0de05 [#2618] Introduce ChannelPromise.unvoid() and ChannelFuture.isVoid()
Motivation:

There is no way for a ChannelHandler to check if the passed in ChannelPromise for a write(...) call is a VoidChannelPromise. This is a problem as some handlers need to add listeners to the ChannelPromise which is not possible in the case of a VoidChannelPromise.

Modification:

- Introduce ChannelFuture.isVoid() which will return true if it is not possible to add listeners or wait on the result.
- Add ChannelPromise.unvoid() which allows to create a ChannelFuture out of a void ChannelFuture which supports all the operations.

Result:

It's now easy to write ChannelHandler implementations which also works when a void ChannelPromise is used.
2014-07-03 14:17:12 +02:00

171 lines
4.3 KiB
Java

/*
* 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.channel.ChannelFlushPromiseNotifier.FlushCheckpoint;
import io.netty.util.concurrent.DefaultPromise;
import io.netty.util.concurrent.EventExecutor;
import io.netty.util.concurrent.Future;
import io.netty.util.concurrent.GenericFutureListener;
/**
* The default {@link ChannelPromise} implementation. It is recommended to use {@link Channel#newPromise()} to create
* a new {@link ChannelPromise} rather than calling the constructor explicitly.
*/
public class DefaultChannelPromise extends DefaultPromise<Void> implements ChannelPromise, FlushCheckpoint {
private final Channel channel;
private long checkpoint;
/**
* Creates a new instance.
*
* @param channel
* the {@link Channel} associated with this future
*/
public DefaultChannelPromise(Channel channel) {
this.channel = channel;
}
/**
* Creates a new instance.
*
* @param channel
* the {@link Channel} associated with this future
*/
public DefaultChannelPromise(Channel channel, EventExecutor executor) {
super(executor);
this.channel = channel;
}
@Override
protected EventExecutor executor() {
EventExecutor e = super.executor();
if (e == null) {
return channel().eventLoop();
} else {
return e;
}
}
@Override
public Channel channel() {
return channel;
}
@Override
public ChannelPromise setSuccess() {
return setSuccess(null);
}
@Override
public ChannelPromise setSuccess(Void result) {
super.setSuccess(result);
return this;
}
@Override
public boolean trySuccess() {
return trySuccess(null);
}
@Override
public ChannelPromise setFailure(Throwable cause) {
super.setFailure(cause);
return this;
}
@Override
public ChannelPromise addListener(GenericFutureListener<? extends Future<? super Void>> listener) {
super.addListener(listener);
return this;
}
@Override
public ChannelPromise addListeners(GenericFutureListener<? extends Future<? super Void>>... listeners) {
super.addListeners(listeners);
return this;
}
@Override
public ChannelPromise removeListener(GenericFutureListener<? extends Future<? super Void>> listener) {
super.removeListener(listener);
return this;
}
@Override
public ChannelPromise removeListeners(GenericFutureListener<? extends Future<? super Void>>... listeners) {
super.removeListeners(listeners);
return this;
}
@Override
public ChannelPromise sync() throws InterruptedException {
super.sync();
return this;
}
@Override
public ChannelPromise syncUninterruptibly() {
super.syncUninterruptibly();
return this;
}
@Override
public ChannelPromise await() throws InterruptedException {
super.await();
return this;
}
@Override
public ChannelPromise awaitUninterruptibly() {
super.awaitUninterruptibly();
return this;
}
@Override
public long flushCheckpoint() {
return checkpoint;
}
@Override
public void flushCheckpoint(long checkpoint) {
this.checkpoint = checkpoint;
}
@Override
public ChannelPromise promise() {
return this;
}
@Override
protected void checkDeadLock() {
if (channel().isRegistered()) {
super.checkDeadLock();
}
}
@Override
public ChannelPromise unvoid() {
return this;
}
@Override
public boolean isVoid() {
return false;
}
}