netty5/transport/src/main/java/io/netty/channel/ChannelOutboundHandlerAdapter.java
Norman Maurer 8f7ef1cabb
Skip execution of Channel*Handler method if annotated with @Skip and … (#8988)
Motivation:

Invoking ChannelHandlers is not free and can result in some overhead when the ChannelPipeline becomes very long. This is especially true if most handlers will just forward the call to the next handler in the pipeline. When the user extends Channel*HandlerAdapter we can easily detect if can just skip the handler and invoke the next handler in the pipeline directly. This reduce the overhead of dispatch but also reduce the call-stack in many cases.

This backports https://github.com/netty/netty/pull/8723 and https://github.com/netty/netty/pull/8987 to 4.1

Modifications:

Detect if we can skip the handler when walking the pipeline.

Result:

Reduce overhead for long pipelines.

Benchmark                                       (extraHandlers)   Mode  Cnt       Score      Error  Units
DefaultChannelPipelineBenchmark.propagateEventOld             4  thrpt   10  267313.031 ± 9131.140  ops/s
DefaultChannelPipelineBenchmark.propagateEvent                4  thrpt   10  824825.673 ± 12727.594  ops/s
2019-04-09 09:36:52 +02:00

128 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.ChannelHandlerMask.Skip;
import java.net.SocketAddress;
/**
* Skeleton implementation of a {@link ChannelOutboundHandler}. This implementation just forwards each method call via
* the {@link ChannelHandlerContext}.
*/
public class ChannelOutboundHandlerAdapter extends ChannelHandlerAdapter implements ChannelOutboundHandler {
/**
* Calls {@link ChannelHandlerContext#bind(SocketAddress, ChannelPromise)} to forward
* to the next {@link ChannelOutboundHandler} in the {@link ChannelPipeline}.
*
* Sub-classes may override this method to change behavior.
*/
@Skip
@Override
public void bind(ChannelHandlerContext ctx, SocketAddress localAddress,
ChannelPromise promise) throws Exception {
ctx.bind(localAddress, promise);
}
/**
* Calls {@link ChannelHandlerContext#connect(SocketAddress, SocketAddress, ChannelPromise)} to forward
* to the next {@link ChannelOutboundHandler} in the {@link ChannelPipeline}.
*
* Sub-classes may override this method to change behavior.
*/
@Skip
@Override
public void connect(ChannelHandlerContext ctx, SocketAddress remoteAddress,
SocketAddress localAddress, ChannelPromise promise) throws Exception {
ctx.connect(remoteAddress, localAddress, promise);
}
/**
* Calls {@link ChannelHandlerContext#disconnect(ChannelPromise)} to forward
* to the next {@link ChannelOutboundHandler} in the {@link ChannelPipeline}.
*
* Sub-classes may override this method to change behavior.
*/
@Skip
@Override
public void disconnect(ChannelHandlerContext ctx, ChannelPromise promise)
throws Exception {
ctx.disconnect(promise);
}
/**
* Calls {@link ChannelHandlerContext#close(ChannelPromise)} to forward
* to the next {@link ChannelOutboundHandler} in the {@link ChannelPipeline}.
*
* Sub-classes may override this method to change behavior.
*/
@Skip
@Override
public void close(ChannelHandlerContext ctx, ChannelPromise promise)
throws Exception {
ctx.close(promise);
}
/**
* Calls {@link ChannelHandlerContext#deregister(ChannelPromise)} to forward
* to the next {@link ChannelOutboundHandler} in the {@link ChannelPipeline}.
*
* Sub-classes may override this method to change behavior.
*/
@Skip
@Override
public void deregister(ChannelHandlerContext ctx, ChannelPromise promise) throws Exception {
ctx.deregister(promise);
}
/**
* Calls {@link ChannelHandlerContext#read()} to forward
* to the next {@link ChannelOutboundHandler} in the {@link ChannelPipeline}.
*
* Sub-classes may override this method to change behavior.
*/
@Skip
@Override
public void read(ChannelHandlerContext ctx) throws Exception {
ctx.read();
}
/**
* Calls {@link ChannelHandlerContext#write(Object, ChannelPromise)} to forward
* to the next {@link ChannelOutboundHandler} in the {@link ChannelPipeline}.
*
* Sub-classes may override this method to change behavior.
*/
@Skip
@Override
public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise) throws Exception {
ctx.write(msg, promise);
}
/**
* Calls {@link ChannelHandlerContext#flush()} to forward
* to the next {@link ChannelOutboundHandler} in the {@link ChannelPipeline}.
*
* Sub-classes may override this method to change behavior.
*/
@Skip
@Override
public void flush(ChannelHandlerContext ctx) throws Exception {
ctx.flush();
}
}