decorator_benchmark.rb

require 'benchmark'

class Coffee
  def cost
    2
  end

  def origin
    "Colombia"
  end
end

module PORO
  class Milk
    def initialize(component)
      @component = component
    end
    
    def cost
      @component.cost + 0.4
    end
  end

  class Sugar
    def initialize(component)
      @component = component
    end
    
    def cost
      @component.cost + 0.2
    end
  end
end

module Decorator
  def initialize(component)
    @component = component
  end

  def method_missing(meth, *args)
    if @component.respond_to?(meth)
      @component.send(meth, *args)
    else
      super
    end
  end

  def respond_to?(meth)
    @component.respond_to?(meth)
  end
end

module MM
  class Milk
    include Decorator
    
    def cost
      @component.cost + 0.4
    end
  end
  class Sugar
    include Decorator
    
    def cost
      @component.cost + 0.2
    end
  end
end

module Inher
  class CoffeeWithSugar < Coffee
    def cost
      super + 0.2
    end
  end

  class CoffeeWithSugarAndMilk < CoffeeWithSugar
    def cost
      super + 0.4
    end
  end
end

iterations = 1_000_000
coffee = Coffee.new
poro = PORO::Sugar.new(PORO::Milk.new(coffee))
mm = MM::Sugar.new(MM::Milk.new(coffee))
inher = Inher::CoffeeWithSugarAndMilk.new

Benchmark.bm do |bm|

  bm.report("PORO") do
    iterations.times do
      poro.cost
    end
  end

  bm.report("MM  ") do
    iterations.times do
      mm.cost
    end
  end

  bm.report("inhe") do
    iterations.times do
      inher.cost
    end
  end
  
end