whitered / ratekeeper

Ratekeeper is a library for scheduling rate-limited actions.

Ratekeeper

Ratekeeper is a library for scheduling rate-limited actions. It supports complex rate limits and estimates time left to resetting limits.

Installation

Add ratekeeper as dependency in mix.exs

def deps do
    [{:ratekeeper, "~> 0.2"}]
end

Usage

Limits can be set in config:

config :ratekeeper, :limits, %{"myapi.org" => [{1000, 5}, {60_000, 100}]}

or at runtime:

Ratekeeper.add_limit "myapi.org", 1000, 5
Ratekeeper.add_limit "myapi.org", 60_000, 100

This sets limits to 5 requests per 1 second and 100 requests per minute.

Appoint a request to rate limited api:

case Ratekeeper.register("myapi.org", 10_000) do
  nil ->
    raise "Rate limits exceeded, request not allowed in next 10 seconds"
  delay ->
    :timer.sleep(delay)
    MyApi.do_request()
end

Full documentation can be found at https://hexdocs.pm/ratekeeper.