netty5/codec-http2/src/main/java/io/netty/handler/codec/http2/Http2FrameStreamVisitor.java
Norman Maurer 74f24a5c19 Finish work on http2 child channel implementation and http2 frame api.
Motivation:

Our http2 child channel implementation was not 100 % complete and had a few bugs. Beside this the performance overhead was non-trivial.

Modifications:

There are a lot of modifications, the most important....
  * Http2FrameCodec extends Http2ConnectionHandler and Http2MultiplexCodec extends Http2FrameCodec to reduce performance heads and inter-dependencies on handlers in the pipeline
  * Correctly handle outbound flow control for child channels
  * Support unknow frame types in Http2FrameCodec and Http2MultiplexCodec
  * Use a consistent way how to create Http2ConnectionHandler, Http2FrameCodec and Http2MultiplexCodec (via a builder)
  * Remove Http2Codec and Http2CodecBuilder as the user should just use Http2MultipleCodec and Http2MultiplexCodecBuilder now
  * Smart handling of flushes from child channels to reduce overhead
  * Reduce object allocations
  * child channels always use the same EventLoop as the parent Channel to reduce overhead and simplify implementation.
  * Not extend AbstractChannel for the child channel implementation to reduce overhead in terms of performance and memory usage
  * Remove Http2FrameStream.managedState(...) as the user of the child channel api should just use Channel.attr(...)

Result:

Http2MultiplexCodec (and so child channels) and Http2FrameCodec are more correct, faster and more feature complete.
2017-08-11 12:41:28 +02:00

39 lines
1.3 KiB
Java

/*
* Copyright 2016 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.handler.codec.http2;
import io.netty.util.internal.UnstableApi;
/**
* A visitor that allows to iterate over a collection of {@link Http2FrameStream}s.
*/
@UnstableApi
public interface Http2FrameStreamVisitor {
/**
* This method is called once for each stream of the collection.
*
* <p>If an {@link Exception} is thrown, the loop is stopped.
*
* @return <ul>
* <li>{@code true} if the visitor wants to continue the loop and handle the stream.</li>
* <li>{@code false} if the visitor wants to stop handling the stream and abort the loop.</li>
* </ul>
*/
boolean visit(Http2FrameStream stream);
}