Protobuf serialization

[kesavkolla]

Can we implement protobuf mapping for cloud event? This will help in generating fast serialization and deserialization.

[jcrossley3]

I'm open to it, but know nothing about doing it. Will we have to include generated code? Or integrate that into CI? What are the tradeoffs?

[kesavkolla]

That is true for protobuf we need to create the proto files before hand. CloudEents can have arbitrary payload so might not work.

[Syndlex]

I dont think this is a Problem.
The spec already provides a proto file.
https://github.com/cloudevents/spec/blob/main/cloudevents/formats/cloudevents.proto

I haven't writen Rust jet.
is this the part where you decide for a Serializer?
https://github.com/cloudevents/sdk-rust/blob/main/src/event/v10/format.rs#L103

@kesavkolla do you know the proto generator toolchain in rust?

The only think i do not understand is how we will get a proto payload into the data... But this is answert somewhere in the java SDK.
https://github.com/cloudevents/sdk-java/tree/main/formats/protobuf/src/main

[Lazzaretti]

Hey @Syndlex
Great to see your interest in implementing this!
I would take a look at the Java SDK, too!

Here is the specification for the format: https://github.com/cloudevents/spec/blob/b43a64bf4fa92baee02dad512f23ea5cb77a321c/cloudevents/formats/protobuf-format.md

About the payload question: Please also take a look here: cloudevents/spec#1186

Feel free to create a PR if you like :)

[Syndlex]

Hey @Lazzaretti
The java sdk has multiple published Modules.
Should the rust Lib also be divided in multiple crates?

I think @slinkydeveloper, you are the Maintainer of this Project. Any Architecture input into this Problem?

[Lazzaretti]

Interesting question!
Please start that discussion on Slack if you don't mind :)
#cloudevents-sdk-rust channel under CNCF's Slack workspace.

We are four maintainers on the project: @jcrossley3, @linuxbasic, @slinkydeveloper, @Lazzaretti.

[slinkydeveloper]

Hi,
I'm not very active anymore on this project, but here's my two cents:

• From what I can tell from my experience with rust, features like supporting a different serialization format are shipped in the same crate behind a feature flag, rather than in a separate module. I wouldn't expect a different module for that.
• It would be cool if we could simply integrate with prost by deriving/implementing the prost::Message trait on the Cloudevent object. Perhaps such implementation could simply proxy to the code-generated prost::Message from the proto file provided in the spec repo, so we wouldn't need to expose the protobuf message itself. Perhaps we could implement prost_reflect::ReflectMessage as well, to easily support reflections and DynamicMessage as well).