http.zig VS libevent

I have a somewhat popular HTTP server library for Zig [1]. It started off as a thread-per-connection (with an optional thread pool), but when it became apparent that async wasn't going to be added back into the language any time soon, I switched to using epoll/kqueue.

Both APIs allow you to associate arbitrary data (void ) with the event that you're registering. So when you're notified of the event, you can access this data. In my case, it's a big Conn struct. It contains things like the # of requests on this connection (to enforce a configured max request per connection), a timestamp where it should timeout if there's no activity. The Conn is part of an intrusive linked list, so it has a next: Conn and prev: *Conn. But, what you're probably most curious about, is that it has a Request.State. This has a static buffer ([]u8) that can grow as needed to hold all the received data up until that point (or if we're writing the data, then the buffered data that we have to write). It's important to have a max # of connections and a max request size so you can enforce an upper limit on the maximum memory the library might use. It acts as a state machine to track up to what point it's parsed the request. (since you don't want to have to re-parse the entire request as more bytes trickle in).

It's all half-baked. I can do receiving/sending asynchronously, but the application handler is called synchronously, and if that, for example, calls PG, that's probably also synchronous (since there's no async PG library in Zig). Makes me feel that any modern language needs a cohensive (as in standard library, or de facto standard) concurrency story.

[1] https://github.com/karlseguin/http.zig

I took a year off, and one of the things I did was learn Zig. I've built a number of libraries, including one of the currently more popular HTTP server libraries (https://github.com/karlseguin/http.zig).

A number of my libraries are used for https://www.aolium.com/ which I decided to write for myself.

I try to write a bit every day with the benefit that I can "waste" time digging into things or exploring likely-to-fail paths.

However, you should be able to use a different version of the library that is compatible with your system. Maybe you can install the development package for `libevent` via the system package manager? That should assure a working state. Otherwise you should be able to download a compatible version from https://libevent.org/ (either binary or source and build it yourself).

They're different. Node uses libuv while chromium uses libevent. You're also seeing different APIs for working with the event loop like nextTick() in Node that doesn't exist in browsers.

Unknown OS, continue trying to install? Menu? Develope this area! Querying Versions on https://libevent.org... Please be patient.

app-id: dev.geopjr.Hashbrown runtime: org.gnome.Platform runtime-version: "3.38" sdk: org.gnome.Sdk command: hashbrown finish-args: - --socket=wayland - --socket=fallback-x11 - --share=ipc cleanup: - /include - /lib/pkgconfig - /share/doc - /share/man - "*.a" - "*.la" modules: - name: libevent sources: - type: git url: https://github.com/libevent/libevent.git tag: release-2.1.12-stable - name: hashbrown buildsystem: simple build-commands: - $(pwd)/crystal/bin/crystal build ./src/hashbrown.cr --no-debug --release - install -D -m 0755 hashbrown /app/bin/hashbrown - install -D -m 0644 extra/Hashbrown.desktop /app/share/applications/dev.geopjr.Hashbrown.desktop - install -D -m 0644 extra/icons/logo.svg /app/share/icons/hicolor/scalable/apps/dev.geopjr.Hashbrown.svg - install -D -m 0644 extra/icons/symbolic.svg /app/share/icons/hicolor/symbolic/apps/dev.geopjr.Hashbrown-symbolic.svg post-install: - install -D -m 0644 extra/dev.geopjr.Hashbrown.metainfo.xml /app/share/metainfo/dev.geopjr.Hashbrown.metainfo.xml sources: - type: git url: https://github.com/GeopJr/Hashbrown.git tag: v1.2.0 commit: 02ecf5cc5aacc32fc484fd9e348d2b1220168295 - type: archive dest: crystal/ url: https://github.com/crystal-lang/crystal/releases/download/1.0.0/crystal-1.0.0-1-linux-x86_64.tar.gz sha256: 00211ca77758e99210ec40b8c5517b086d2ff9909e089400f6d847a95e5689a4 - type: git url: https://github.com/jhass/crystal-gobject.git commit: 6468c57f8aa54b71c766d27b1e59e87a09ee8552 dest: lib/gobject - type: git url: https://github.com/elorest/compiled_license.git tag: v0.1.3 commit: f287c2c8c95579688fa5620df954d8cc1272cbbf dest: lib/compiled_license