as_callbacks.rb

require "benchmark/ips"

require "active_support/callbacks"

class NormalMethod
  def before
    :before
  end

  def perform
    before
    :perform
  end
end

class NaiveMethod

  def initialize
    @before_callbacks = []
    @before_callbacks << lambda { :before }
  end

  def perform
    @before_callbacks.each { |cb| cb.call }
    :perform
  end
end

class CallbackMethod
  include ActiveSupport::Callbacks

  define_callbacks :perform

  set_callback :perform, :before do
    :before
  end

  def perform
    run_callbacks :perform do
      :perform
    end
  end
end



Benchmark.ips do |x|
  x.report("normal w/ init") { NormalMethod.new.perform }
  x.report("naive w/ init")  { NaiveMethod.new.perform }
  x.report("as::cb w/ init") { CallbackMethod.new.perform }

  NORMAL = NormalMethod.new
  NAIEVE = NaiveMethod.new
  CALLBACK = CallbackMethod.new

  x.report("normal w/o init") { NORMAL.perform }
  x.report("naive w/o init")  { NAIEVE.perform }
  x.report("as::cb w/o init") { CALLBACK.perform }
end

results.txt

Warming up --------------------------------------
      normal w/ init   147.639k i/100ms
       naive w/ init    53.250k i/100ms
      as::cb w/ init    10.227k i/100ms
     normal w/o init   175.545k i/100ms
      naive w/o init   149.439k i/100ms
     as::cb w/o init    12.302k i/100ms
Calculating -------------------------------------
      normal w/ init      3.172M (± 9.2%) i/s -     15.797M in   5.036397s
       naive w/ init    803.257k (±21.8%) i/s -      3.834M in   5.041431s
      as::cb w/ init    114.992k (±13.5%) i/s -    562.485k in   5.011706s
     normal w/o init      4.763M (± 4.6%) i/s -     23.874M in   5.022535s
      naive w/o init      2.838M (± 4.0%) i/s -     14.197M in   5.010108s
     as::cb w/o init    140.246k (±11.3%) i/s -    701.214k in   5.070732s