module Monus::BuiltInMetric::EmCallbacks

Public Instance Methods

activate() click to toggle source
# File lib/monus/built_in_metrics/em_callbacks.rb, line 2
def activate
  @interval = Monus.options.dig(:em_callbacks_metric_options, :interval) || 1

  begin
    require 'lspace/eventmachine'
  rescue LoadError
    raise LoadError, 'in order to use em_callbacks metric you should add `lspace` gem to your Gemfile'
  end

  timings = []

  LSpace.around_filter do |&block|
    time = Process.clock_gettime(Process::CLOCK_MONOTONIC)
    begin
      block.call
    ensure
      delta = Process.clock_gettime(Process::CLOCK_MONOTONIC) - time
      timings.push(delta)
    end
  end

  Monus.engine.every @interval do
    slice = timings.slice!(0..-1)

    next if slice.empty?

    number = slice.size
    maximum = slice.max
    total = slice.sum

    Monus.write em_callbacks_number: number,
                em_callbacks_maximum: maximum,
                em_callbacks_total: total
  end
end