(author here) I'm just adding data-race free parallelism support to this right now to switch my website over to using it! For those familiar with OCaml syntax, the OxCaml parse function is fun:

    val parse : buffer -> len:int -> #(status * request * header list) @ local

This takes in a buffer and returns an unboxed tuple on the stack, so there's no GC activity involved beyond stack management for each HTTP request.

https://github.com/avsm/httpz/blob/main/lib/httpz.mli#L154