Non-blocking IO support with Ruby 3.x fiber scheduler

[dbackeus]

No idea about the feasibility of this but would be really nice if ethon could enable non-blocking IO when using a Ruby 3.x fiber scheduler the same way as Ruby's native IO libraries.

For example the following will execute in ~2 seconds:

require "fiber_scheduler"
require "open-uri"

Fiber.set_scheduler(FiberScheduler.new)

Fiber.schedule do
  URI.open("https://httpbin.org/delay/2")
end

Fiber.schedule do
  URI.open("https://httpbin.org/delay/2")
end

While using ethon will block on each HTTP request and execute in ~4 seconds:

require "fiber_scheduler"
require "ethon"

Fiber.schedule do
  Ethon::Easy.new(url: "https://httpbin.org/delay/2").perform
end

Fiber.schedule do
  Ethon::Easy.new(url: "https://httpbin.org/delay/2").perform
end

These examples assume using Ruby 3.1.x with the fiber_scheduler gem installed.

Supporting non blocking IO will be important for eg. typhoeus to remain popular while more and more Ruby code migrates towards using fibers for more efficient IO.

[hanshasselberg]

Ethon is a little bit different because it is a wrapper for libcurl. Libcurl however already supports parallel requests and so does Ethon via Multi: https://rubydoc.info/github/typhoeus/ethon/Ethon/Multi. And Typhoeus via Hydra: https://github.com/typhoeus/typhoeus/#making-parallel-requests.

I don't think we can add support for fiber. But I might be wrong and I am would be happy to learn about a way to do it.