Class: Rookout::Augs::AugRateLimiter

Inherits:
Object
  • Object
show all
Defined in:
lib/rookout/augs/aug_rate_limiter.rb

Instance Method Summary collapse

Constructor Details

#initialize(quota, window_size, active_limit) ⇒ AugRateLimiter

Returns a new instance of AugRateLimiter.



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# File 'lib/rookout/augs/aug_rate_limiter.rb', line 7

def initialize quota, window_size, active_limit
  @quota = quota
  @has_quota = !@quota.nil? && (@quota > 0)
  @window_size = window_size
  if active_limit > 0
    @active_weight = quota / active_limit
  else
    @active_weight = 0
  end

  @mutex = Mutex.new
  @active_count = 0
  @windows = {}
end

Instance Method Details

#after_run(start_time) ⇒ Object 



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# File 'lib/rookout/augs/aug_rate_limiter.rb', line 47

def after_run start_time
  if @has_quota
    now_ns = Utils.time_to_nanoseconds start_time
    current_window_key, = timestamp_to_window_keys now_ns
    time_used = Utils.time_to_nanoseconds(Time.now) - now_ns
    time_recorded = time_used > Config.min_rate_limit_value_ns ? time_used : Config.min_rate_limit_value_ns
    @mutex.synchronize { record_usage current_window_key, time_recorded }
  end
  # Reduce active count
  @mutex.synchronize { @active_count -= 1 }
end

#before_run(start_time) ⇒ Object 



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# File 'lib/rookout/augs/aug_rate_limiter.rb', line 22

def before_run start_time
  # If no quota, we can safely exit
  unless @has_quota
    return true
  end
  now_ns = Utils.time_to_nanoseconds start_time
  current_window_key, prev_window_key = timestamp_to_window_keys now_ns

  @mutex.synchronize do
    # Clean old windows
    cleanup now_ns
    usage = current_usage now_ns, current_window_key, prev_window_key
    @active_count += 1

    # If exceeding quota
    if usage > @quota
      warning = Processor::RookError.new Exceptions::RookRuleRateLimited.create
      UserWarnings.notify_warning warning
      return false
    end

    return true
  end
end