Benchmark String#freeze

freeze_benchmark.rb

#!/usr/bin/env ruby

# Based on http://blog.honeybadger.io/when-to-use-freeze-and-frozen-in-ruby/#reducing-object-allocations
# but for Ruby 1.9.3
require 'benchmark'
class FreezeBenchmark
  NORMAL = 'NORMAL'
  FROZEN = 'FROZEN'.freeze

  def self.init(n = 100000)
    Benchmark.bm do |x|
      x.report("normal") { n.times { get_string(false) } }
      x.report("frozen") { n.times { get_string(true)  } }
    end
  end

  private

  def self.get_string(use_frozen)
    return use_frozen ? FROZEN : NORMAL
  end

end
FreezeBenchmark.init

# Results with MRI 1.9.3p551:
#        user     system      total        real
# normal  0.010000   0.000000   0.010000 (  0.012295)
# frozen  0.010000   0.000000   0.010000 (  0.009562)

# Results with MRI 2.2.7p470:
#        user     system      total        real
# normal  0.010000   0.000000   0.010000 (  0.007917)
# frozen  0.010000   0.000000   0.010000 (  0.007820)

# Results with MRI 2.4.1p111:
#        user     system      total        real
# normal  0.010000   0.000000   0.010000 (  0.007662)
# frozen  0.010000   0.000000   0.010000 (  0.006562)