A perf test of Ruby's OpenStruct vs a few other options

open_struct_perf_test.rb

# OpenStruct is slow. But if you need/want similar functionality,
# you can achieve it with really good perf results. See the impl
# of NotificationEvent below.
#
# Benchmark results from my Macbook (2.6 GHz Intel Core i5)
#
# Rehearsal -----------------------------------------------------
# Literal             1.060000   0.020000   1.080000 (  1.080056)
# NotificationEvent   1.350000   0.000000   1.350000 (  1.367066)
# OpenStruct         11.500000   0.110000  11.610000 ( 11.646464)
# ------------------------------------------- total: 14.040000sec
#
#                         user     system      total        real
# Literal             1.000000   0.010000   1.010000 (  1.015018)
# NotificationEvent   1.380000   0.010000   1.390000 (  1.395112)
# OpenStruct         11.980000   0.300000  12.280000 ( 12.798998)

require 'benchmark'
require 'ostruct'

class Literal
  attr_reader :event_name, :user, :age

  def initialize(event_name, hash)
    @event_name = event_name
    @user = hash[:user]
    @age = hash[:age]
  end
end

# NotificationEvent is essentially a struct, no methods, just read-only
# properties describing the event.
class NotificationEvent
  attr_reader :event_name

  def initialize(event_name, hash)
    @event_name = event_name
    @hash = hash
  end

  # Exposes hash keys as object properties for easier access and better duck-typing
  def method_missing(mid, *args)
    if args.length > 0
      raise "Property #{mid} does not accept arguments #{args}"
  	end

    @hash.fetch(mid)
  end
end

def test_struct(count)
  x = 0

  for i in 0..count
    evt = yield
    x += evt.age + evt.user.length
  end

  return x
end

def literal_test(count)
  test_struct(count) { Literal.new('foo', user: 'Chris', age: 23) }
end

def notify_test(count)
  test_struct(count) { NotificationEvent.new('foo', user: 'Chris', age: 23) }
end

def open_test(count)
  test_struct(count) { OpenStruct.new(user: 'Chris', age: 23) }
end

Benchmark.bmbm do |x|
  count = 1000000
  x.report('Literal') { literal_test(count) }
  x.report('NotificationEvent') { notify_test(count) }
  x.report('OpenStruct') { open_test(count) }
end