prototk
I wanted to be able to annotate a struct and automatically generate all the protocol buffers for it. I explicitly did not want to rely upon a build.rs or worse, files generated upon check-in.
Concretely, I wanted something that looks like this:
#[derive(Debug, Default, Message)]
pub enum Error {
#[prototk(278528, message)]
#[default]
Success {
#[prototk(1, message)]
core: ErrorCore,
},
#[prototk(278529, message)]
SerializationError {
#[prototk(1, message)]
core: ErrorCore,
#[prototk(2, message)]
err: prototk::Error,
#[prototk(3, string)]
context: String,
},
#[prototk(278530, message)]
UnknownServerName {
#[prototk(1, message)]
core: ErrorCore,
#[prototk(2, string)]
name: String,
},
#[prototk(278531, message)]
UnknownMethodName {
#[prototk(1, message)]
core: ErrorCore,
#[prototk(2, string)]
name: String,
},
#[prototk(278532, message)]
RequestTooLarge {
#[prototk(1, message)]
core: ErrorCore,
#[prototk(2, uint64)]
size: u64,
},
}
The equivalent code in protocol buffers requires many intermediate structs—-one per variation on the enum fields. Prototk will automatically act as if the intermediate type was synthesized. This enables enums like the above to serialize and deserialize easily:
// serialize
let err = Error::UnknownServerName {
core: ErrorCore::new("robert@rescrv.net", "unknown server name", &UNKOWN_SERVER_NAME_COUNTER),
name: "FooRpcServer",
};
let buf = stack_pack(err).to_vec()
// deserialize
let up = Unpacker::new(buf);
let err: Error = up.unpack()?;
Prototk is currently available on cargo at version 0.1.0.