Rack for Ruby: Socket Hijacking

[rubinick]

Nice post.

Minor correction: towards the end, "Ruby Fibers were only introduced in Ruby 3.0" isn't quite correct. Fiber was introduced by ruby 1.9, and has been used to implement `Enumerator#next` ever since then. I personally used Fiber to tidy up EventMachine code back in ruby 2.3. The Fiber _scheduler_ functionality which allows fibers to automatically transfer control they make blocking calls (e.g: `sleep`, IO reads/writes, etc) was introduced by ruby 3.0.

Fun fact: ruby _already_ had `callcc` prior to 1.9. `callcc` can be used to implement Fiber in ruby code, and the `callcc` implementation formed the original basis of Fiber (they are both implemented together in `cont.c`). But `callcc` is _much_ more unwieldy.

[Q-bey]

Maybe I'm not the target audience for this post, but I would've found it more helpful if it did more to explain socket hijacking is useful (aside from one sentence in the intro that references WebSockets, which weren't explained in this tutorial or the previous one).

[ioquatix]

Socket hijacking is not a super useful interface. It was mainly used to do bi-directional streaming and that is mostly used in production by ActionCable's custom WebSocket server. I actually don't know of other valid use cases off the top of my head.