I attempted to mimic Go's single flight package myself [0]. It doesn't have support for the asynchronous world but I suppose that could be made possible. I also have to mention bradfitz for providing the initial implementation (I think?) to learn from. It's really quite elegant!
Does anyone else think the Rust HTTP ecosystem is becoming increasingly fragmented? I can't keep track of which library is best suited for common operations. Is it a web framework built on hyper? Should I pay attention to tower middleware? Where does tracing fit in?
I actually think it's gone through a period of fragmentation, and is now heading back towards a more unified ecosystem:
- There was a split between tokio and async-std asynchronous executors, but the ecosystem now seems to be coalescing back around tokio.
- There was weird split where Hyper was the de facto http library, but the best web framework was actix-web which wasn't based on hyper. But now there is Axum, an official Tokio project that is good enough to generally recommended for all web projects, and looks to be the project with momentum going forwards.
- Tracing is really the only game in town when it comes to asynchronous logging, and again is part of the Tokio project.
Tower is a bit of a weird one. It's a very general middleware layer which I think does actually provide a very good abstraction. But that abstraction is quite complex, and learning it is in many cases trickier than doing an implementation from scratch. I suspect it might come to play a bigger part in the Rust ecosystem at some point, but for now I'd ignore it.
I don't write Rust professionally, but it was a bummer seeing that this seems to be a place that was figured out (painfully) in ecosystems used heavily for web development--Javascript and Elixir have their own Rack equivalents[2][3]. I hope that Tower plays a similar role to unify the library ecosystem in Rust.
1. https://github.com/rack/rack