string_benchmark.rb

require 'benchmark/ips'

class Cocada
  attr_accessor :string

  def mocked_size
    50
  end
end

Benchmark.ips do |x|
  x.time = 10
  x.warmup = 2

  x.report('accessing attribute reader') do
    cocada = Cocada.new
    cocada.string = ('Lorem Ipsum dolor sit amet' * rand(10))

    cocada.mocked_size
  end

  x.report('live counting') do
    cocada = Cocada.new
    cocada.string = ('Lorem Ipsum dolor sit amet' * rand(10))

    cocada.string.size
  end

  x.compare!
end