Motivation:
The Http2DefaultFrameWriter copies all contents into a buffer (or uses a CompositeBuffer in 1 case) and then writes that buffer to the socket. There is an opportunity to avoid the copy operations and write directly to the socket.
Modifications:
- Http2DefaultFrameWriter should avoid copy operations where possible.
- The Http2FrameWriter interface should be clarified to indicate that ByteBuf objects will be released.
Result:
Hopefully less allocation/copy leads to memory and throughput performance benefit.
Motivation:
Http2Stream has several methods that provide state information. We need
to simplify how state is used and consolidate as many of these fields as
possible.
Modifications:
Since we already have a concept of a stream being active or inactive,
I'm now separating the deactivation of a stream from the act of closing
it. The reason for this is the case of sending a frame with
endOfStream=true. In this case we want to close the stream immediately
in order to disallow further writing, but we don't want to mark the
stream as inactive until the write has completed since the inactive
event triggers the flow controller to cancel any pending writes on the
stream.
With deactivation separated out, we are able to eliminate most of the
additional state methods with the exception of `isResetSent`. This is
still required because we need to ignore inbound frames in this case (as
per the spec), since the remote endpoint may not yet know that the
stream has been closed.
Result:
Fixes#3382
Motivation:
Previously flow-controller had to know the implementation details of each frame type in order to write it correctly. That concern is more correctly handled by the encoder. By encapsulating the payload types to be flow-controlled it will be easier to add support for extension types later. This change also fixes#3353.
Modifications:
Add interface FlowControlled which is now delivered to flow-controller.
Implement this interface for HEADERS and DATA
Refactor and improve tests for flow-control.
Result:
Flow control semantics are more cleanly separated for data encoding and implementation is simpler overall.
Motivation:
A downstream consumer of Netty failed as emitting zero-length http2 data frames in a unit test resulted in assertion errors in Http2LocalFlowController. Since zero-length frames are valid, an assertion that http2 data frame length must be positive is invalid.
Modifications:
Assertions of data length in Http2LocalFlowController now permit zero.
Result:
Those running netty with assertions on can now emit zero length http2 data frames.
Motivation:
HTTP/2 codec was implemented in master branch.
Since, master is not yet stable and will be some time before it gets released, backporting it to 4.1, enables people to use the codec with a stable netty version.
Modification:
The code has been copied from master branch as is, with minor modifications to suit the `ChannelHandler` API in 4.x.
Apart from that change, there are two backward incompatible API changes included, namely,
- Added an abstract method:
`public abstract Map.Entry<CharSequence, CharSequence> forEachEntry(EntryVisitor<CharSequence> visitor)
throws Exception;`
to `HttpHeaders` and implemented the same in `DefaultHttpHeaders` as a delegate to the internal `TextHeader` instance.
- Added a method:
`FullHttpMessage copy(ByteBuf newContent);`
in `FullHttpMessage` with the implementations copied from relevant places in the master branch.
- Added missing abstract method related to setting/adding short values to `HttpHeaders`
Result:
HTTP/2 codec can be used with netty 4.1
