As an experiment to wring more performance from the snowflake bridge, I started a rough port of the extor-static-cookie shim to Rust. It's not in what I would call a production-ready state with regard to documentation and tests—I wanted to hack something together quickly in order to decide whether it's worth spending more time on. I am also pretty new to Rust async programming. As a side consideration, I wanted to get an idea of what a pluggable transports library for Rust might look like.
https://gitlab.torproject.org/dcf/extor-static-cookie/-/tree/rust Currently commit 559fb5e292b45d82464bdaf978c6e1783c796e3d
I have the Rust implementation running now (since 2022-02-27 03:00) under the flakey4 instance. The other three instances are running the Go implementation. It's too early to say whether it reduces CPU usage; an hour after being restarted, the flakey4 instance is still catching up to the traffic of the other instances. But it looks like it's stable and functional, at least.