/
rate_queue.rb
71 lines (52 loc) · 1.09 KB
/
rate_queue.rb
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# frozen_string_literal: true
module Limiter
class RateQueue
EPOCH = 0.0
def initialize(size, interval: 60, balanced: false, &blk)
@size = size
@interval = interval
@balanced = balanced
@mutex = Mutex.new
@blk = blk
reset
end
def reset
@mutex.synchronize do
@ring = @balanced ? balanced_ring : unbalanced_ring
@head = 0
end
end
def shift
time = nil
@mutex.synchronize do
time = @ring[@head]
sleep_until(time + @interval)
@ring[@head] = clock.time
@head = (@head + 1) % @size
end
time
end
private
def sleep_until(time)
interval = time - clock.time
return unless interval.positive?
@blk&.call
clock.sleep(interval)
end
def clock
Clock
end
def unbalanced_ring
Array.new(@size, EPOCH)
end
def balanced_ring
(0...@size).map { |i| base_time + (gap * i) }
end
def gap
@interval.to_f / @size.to_f
end
def base_time
clock.time - @interval
end
end
end