X2 Dome interface protocol buffer WIP

[AnthonyHorton]

I've started an attempt to translate the TSX X2 Dome interface specification into protocol buffer .proto format so that we can use the grpc tools to generate template code for the X2 plugin & Raspberry Pi code.

[wtgee]

Seems straightforward.

[wtgee]

The spec doesn't call for it but do we want to be returning a common status object or something for all these?

[AnthonyHorton]

Probably. Have been pondering how best to handle the fact that this interface definition is coming from old school C-ish C++ code where every function returns an integer, which may or may not be meaningful, and all the substantial return values are retrieved by passing in pointers as arguments. Probably should include the integer return value in the response 'message' for all of these.

[wtgee]

Suggested change

	rpc UnPark (Empty) returns (Empty);
	rpc Unpark (Empty) returns (Empty);

The spec doesn't capitalize the 'P' here. Feel free to ignore if you wanted it this way though.

[AnthonyHorton]

Oops. No, was trying to copy the formatting from the interface definition.

[wtgee]

Suggested change

	rpc UnParkComplete (Empty) returns (IsComplete);
	rpc UnparkComplete (Empty) returns (IsComplete);

[wtgee]

Ideally this could be generic and not just X2, right? Wondering if we should make the class (and file) name more generic.

[AnthonyHorton]

Well, in a way it is generic in as much as these are the sorts of RPC's, requests and responses that you might expect most domes to use. This protocol buffer file is intended to correspond directly to the X2 plugin Dome interface though, so that the template client code generated by the C++ version of the grpc tools could be used to write an actual X2 plugin.

[lspitler]

@AnthonyHorton how can @fergusL and I move this forward? Is it just running your initial config using grpc?

[fergusL]

I'm just going to merge this and open a new PR with the stuff I've done on top of this