Class: Async::Throttler

Inherits:
Object
  • Object
show all
Defined in:
lib/async/throttler.rb

Overview

inspired by github.com/negativecode/vines/blob/master/lib/vines/token_bucket.rb

Instance Method Summary collapse

Constructor Details

#initialize(capacity, rate, parent: Async::Task.current) ⇒ Throttler

Returns a new instance of Throttler.

Raises:

  • (ArgumentError) 


5
6
7
8
9
10
11
12
13
14
15
 
# File 'lib/async/throttler.rb', line 5

def initialize(capacity, rate, parent: Async::Task.current)
  raise ArgumentError, "capacity must be > 0" unless capacity.positive?
  raise ArgumentError, "rate must be > 0" unless rate.positive?

  @capacity = capacity
  @tokens = capacity
  @rate = rate
  @parent = parent

  @timestamp = Time.new
end

Instance Method Details

#async(parent: @parent, timeout: 0) ⇒ Object 



28
29
30
31
 
# File 'lib/async/throttler.rb', line 28

def async(parent: @parent, timeout: 0, &)
  wait(timeout:)
  parent.async(&)
end

#wait(timeout: 0) ⇒ Object 



17
18
19
20
21
22
23
24
25
26
 
# File 'lib/async/throttler.rb', line 17

def wait(timeout: 0)
  with_timeout(timeout) do
    while @tokens < 1
      fill!
      sleep(1.0 / @rate)
    end
  end

  @tokens -= 1
end