Update high_level_multiplayer.rst

[scotmcp]

Clarifying RPC checksum, and how all RPCs on a script must have matching partners on the target peer's script as well.

[mhilbrunner]

Thanks for contributing! Not sure we should be calling it a checksum - we're just sending an ID based on the function name and path. Functionally, I guess it is a checksum, but that makes me think of something more complex than a simple numerical ID.

We should also maybe mention here that both path and function name must match.

[AThousandShips]

It being a checksum, if it is, could be an implementation detail and shouldn't be mentioned unless it's considered a stable detail, we avoid specifying things like that unless it really matters to leave the option to modify things at need

This is specific for checking the interfaces match, I think saying the names match should be sufficient:

String SceneRPCInterface::get_rpc_md5(const Object *p_obj) {
	const Node *node = Object::cast_to<Node>(p_obj);
	ERR_FAIL_NULL_V(node, "");
	const RPCConfigCache cache = _get_node_config(node);
	String rpc_list;
	for (const KeyValue<uint16_t, RPCConfig> &config : cache.configs) {
		rpc_list += String(config.value.name);
	}
	return rpc_list.md5_text();
}

[scotmcp]

Yeah it is a checksum, and I think due to what I consider why, that it would remain a stable solution. Sending a checksum rather than the strings is much more efficient use of the network. Additionally, we are speaking to network developers, or at least people who want to become. Regarding whether we should mentioned checksum or not, the ERROR message that results specifically says it's a checksum error, so I think it makes sense to be clear about that in the warning box, it would make searching the MultiplayerAPI web page for "checksum", much more direct and get the developer right to the warning message!

I will look at my patch again and see if I can word smith it a little better.

[scotmcp]

I made a new commit.

[scotmcp]

Ok I promise I am done making changes now.

[scotmcp]

Checking in here, is there anything else I need to do?

[mhilbrunner]

Committed the above minor styling improvements and squashed and merged. Thanks and congrats on your first merged contribution! 🎉 Thanks for contributing!

[scotmcp]

Thank you M !!!

[mhilbrunner]

Cherry-picked to 4.2.

[scotmcp]

w00t