gdbstub VS Rouille, Rust web server middleware

now integrate gdbstub to support debugging code inside the emulator :)

Shameless plug, but have you considered integrating gdbstub rather than rolling your own debugger? I know a couple folks out there have successfully integrated it into their PS1 emulators with great success.

I've worked really hard to keep gdbstub panic free in its minimal configuration, going so far as to write some informal scripts that parse rustc's asm output to scan for the presence of panicking code paths.

crates.io | docs | repo

As a totally shameless plug, I'm the maintainer of gdbstub, a bare-metal, no_std, no_alloc, and size-optimized implementation of the GDB Remote Serial Protocol. One of the major changes slated for the upcoming release 0.6 is support for a new state-machine based API, which makes it possible to drive gdbstub directly via bare metal interrupt handlers (i.e: send/recv data over UART, handling breakpoints via the undefined instruction trap interrupt, etc...).

Continue working on a new API in gdbstub that'll make it easier to use directly from an interrupt handler when debugging code in a no_std, bare-metal OS environment.

I ran into almost this exact same problem while working on gdbstub, whereby I an API that allowed users to mix/match protocol features however they wanted, while also preventing users from accidentally implementing mutually-exclusive features. Moreover, I wanted to have a "zero cost" way to enable/disable API features without relying on cargo features. The solution I came up with is something I've been calling "Inlineable Dyn Extension Traits", or IDETs.

For a concrete example of how smart the Rust compiler is, I have a small writeup + test-repo that benchmarks a technique I came up with while working on gdbstub that [ab]uses the compiler's devirtualization and inlining optimizations to create runtime feature flags that are entirely compiled out if hard-coded to false at runtime.

Your CRUD web application server almost certainly doesn't need async Rust. Using a blocking HTTP server is not "might be a good idea", it simply is a good idea.

I recommend Rouille for this: https://github.com/tomaka/rouille. In case you are worried about performance, check the benchmark. Blocking Rouille is faster than builtin async server in Node.js.

As you say, the majority of the web ecosystem in Rust has moved to async - but if you’re happy to stray a bit from the beaten path then rouille might do the trick.

In strongly typed languages like Rust, composing smaller libraries is usually quite painless, so you don't need a large framework.

Personally for backend Rust I use rouille[0] for the server (it's very simple and async-free), askama[1] for compile-time HTML templates and (if a SPA is unavoidable, as that is of course always to be avoided if at all possible) yew[2] for client-side WASM.

Now this stack is what I like personally, but there are many options that you can combine, some more full-featured than others. Check out https://www.arewewebyet.org/ for a partial overview.

[0]: https://github.com/tomaka/rouille

[1]: https://github.com/djc/askama

[2]: https://yew.rs/

rouille

I'd like to put in a word for a simple, sync framework such as rouille. The compile times are much, much better, the number of dependencies is much smaller, the stuff it's built on (the standard library) is extensively tested and extremely reliable. Kernel context switches are slower than userspace thread scheduling, but not much slower, and as long as your services aren't just shoving bytes from one place to another (i.e. actually doing some computation) the time taken for a context switch vanishes into noise. A lot of benchmarks test how quickly a web service can move bytes, which (if your business logic is non-trivial) actually isn't the most critical factor.

I don't have any Rust-relevant experience here, but if I wanted to build a web server in Rust and was okay with "reasonable" performance, I'd probably give rouille a try first.

Rouille is fairly solid in my experience. Save the pain of async and spend it building software that works. Honestly with Rust's lack of GC you get predictable response times already.

How would you differentiate it from let's say Rouille ?