Hamerkop - Experimental caching server based off of io_uring

This is an experiment in writing the networking part of a cache server using io_uring to run the needed network calls asynchronously. The main parts are composed of two projects:

1. uring - A binding to the io_uring APIs, and
2. hamerkop - An async executor built on top of uring.

This is meant more as an exploratory playground to figure out how to make use this API to build the networking component of the cache server while maintaining a consistently low latency the entire time.

Since this repo is meant to be experimentation around writing a cache server there are also experiments in writing some of the other components that are part of a well-functioning cache:

1. metrics - A distributed metrics registration crate that allows metrics to be created declare anywhere as globals (using the appropriate registration macro) and then accessed as a global list when needed.
2. tokenreplace - A find-and-replace macro that runs after other attribute macros have been expanded.

Examples

hamerkop/examples contains two examples showing how the library could be used. These are respectively a pingserver and an echo server. They were developed on linux 5.10 but may work a few versions earlier than that.

To run them do one of

cargo run --examples echoserver
cargo run --examples pingserver

and then the respective server will start listening on port 8000.