NEXT+COMPLETE RequestResponse Efficiency

[benjchristensen]

Currently request/response requires 2 messages to complete (NEXT + COMPLETE): ;https://github.com/ReactiveSocket/reactivesocket-java/blob/e38b757ca02e597712139dfb9d01ba5dc7079c40/src/main/java/io/reactivesocket/ReactiveSocketServerProtocol.java#L105

The protocol design will support multiple headers (types) being sent in a single frame.

1. We need to at least get NEXT and COMPLETE together in a single frame.
2. Is there a more efficient way to do this in the Java implementation? A stream of 2 can not be optimized like a scalar, synchronous Observable of 1 so will have a higher cost as currently implemented. Capturing NEXT then COMPLETE and knowing to batch them together is more difficult than a special type, such as NEXT_COMPLETE.

I'm not suggesting the network protocol needs a new type, only that we figure out the optimization in Java.

[tmontgomery]

If the responder can package a NEXT and COMPLETE together to hand to the protocol together, then the protocol can batch them into a single frame trivially.

[NiteshKant]

Since we know by stream initiation that a particular request is request-response, do we even need a complete event. Complete is implicit upon receiving a complete data frame(s) including fragmented frames.

[tmontgomery]

@NiteshKant true. For REQUEST_RESPONSE, there is only a single NEXT. If that is the semantic, could possibly collapse it down to just a completed and reassembled NEXT. I.e. a NEXT with the END bit set.

[benjchristensen]

Implemented.