These changes allow an RPCHandler to receive an upload as a stream of
data, without having to buffer the entire message in the FrameDecoder.
The primary use case is for replicating large blocks. By itself, this change is adding dead-code that is not being used -- it is a step towards SPARK-24296.
Added unit tests for handling streaming data, including successfully sending data, and failures in reading the stream with concurrent requests.
Summary of changes:
* Introduce a new UploadStream RPC which is sent to push a large payload as a stream (in contrast, the pre-existing StreamRequest and StreamResponse RPCs are used for pull-based streaming).
* Generalize RpcHandler.receive() to support requests which contain streams.
* Generalize StreamInterceptor to handle both request and response messages (previously it only handled responses).
* Introduce StdChannelListener to abstract away common logging logic in ChannelFuture listeners.
Author: Imran Rashid <irashid@cloudera.com>
Closes#21346 from squito/upload_stream.
16f2c3ea46