netty5/example/src/main/java/io/netty/example/http2/helloworld/multiplex/server/Http2OrHttpHandler.java
Eric Anderson e24a5d8839 Map HTTP/2 Streams to Channels
Motivation:

This allows using handlers for Streams in normal Netty-style. Frames are
read/written to the channel as messages, not directly as a
callback/method call. Handlers allow mixing and can ease HTTP/1 and
HTTP/2 interoperability by eventually supporting HTTP/1 handlers in
HTTP/2 and vise versa.

Modifications:

New handler Http2MultiplexCodec that converts from the current HTTP/2
API to a message-based API and child channels for streams.

Result:

The basics are done for server-side: new streams trigger creation of new
channels in much the same appearance to how new connections trigger new
channel creation. The basic frames HEADERS and DATA are handled, but
also GOAWAY and RST_STREAM.

Inbound flow control is implemented, but outbound is not. That will be
done later, along with not completing write promises on the child
channel until the write actually completes on the parent.

There is not yet support for outbound priority/weight, push promises,
and many other features.

There is a generic Object that may be set on stream frames. This also
paves the way for client-side support which needs a way to refer to
yet-to-be-created streams (due to how HEADERS allocates a stream id, and
the allocation order must be the same as transmission order).
2016-03-25 12:14:44 -07:00

54 lines
2.2 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.example.http2.helloworld.multiplex.server;
import io.netty.channel.ChannelHandlerContext;
import io.netty.example.http2.helloworld.server.HelloWorldHttp1Handler;
import io.netty.handler.codec.http.HttpObjectAggregator;
import io.netty.handler.codec.http.HttpServerCodec;
import io.netty.handler.codec.http2.Http2MultiplexCodec;
import io.netty.handler.ssl.ApplicationProtocolNames;
import io.netty.handler.ssl.ApplicationProtocolNegotiationHandler;
/**
* Negotiates with the browser if HTTP2 or HTTP is going to be used. Once decided, the Netty
* pipeline is setup with the correct handlers for the selected protocol.
*/
public class Http2OrHttpHandler extends ApplicationProtocolNegotiationHandler {
private static final int MAX_CONTENT_LENGTH = 1024 * 100;
protected Http2OrHttpHandler() {
super(ApplicationProtocolNames.HTTP_1_1);
}
@Override
protected void configurePipeline(ChannelHandlerContext ctx, String protocol) throws Exception {
if (ApplicationProtocolNames.HTTP_2.equals(protocol)) {
ctx.pipeline().addLast(new Http2MultiplexCodec(true, new HelloWorldHttp2Handler()));
return;
}
if (ApplicationProtocolNames.HTTP_1_1.equals(protocol)) {
ctx.pipeline().addLast(new HttpServerCodec(),
new HttpObjectAggregator(MAX_CONTENT_LENGTH),
new HelloWorldHttp1Handler("ALPN Negotiation"));
return;
}
throw new IllegalStateException("unknown protocol: " + protocol);
}
}