benchmark_hashes.rb

require 'benchmark'
 

module Helper1
  def twitterized_type(type)
    case type
      when :alert
        "warning"
      when :error
        "error"
      when :notice
        "info"
      when :success
        "success"
      else
        type.to_s
    end
  end
  module_function :twitterized_type
end

module Helper2
  def twitterized_type(type)
    {
      alert:   'warning',
      error:   'error',
      notice:  'info',
      success: 'success'
    }.fetch(type, type.to_s)
  end  
  module_function :twitterized_type
end

module Helper3
  def twitterized_type(type)
    {
      alert:   'warning',
      error:   'error',
      notice:  'info',
      success: 'success'
    }[type] || type.to_s
  end  
  module_function :twitterized_type
end

module Helper4
  TT={
      alert:   'warning',
      error:   'error',
      notice:  'info',
      success: 'success'
    }
  def twitterized_type(type)
    TT.fetch(type, type.to_s)
  end  
  module_function :twitterized_type
end

module Helper5
  
  def twitterized_type(type)
  tt ||= {
      alert:   'warning',
      error:   'error',
      notice:  'info',
      success: 'success'
    }
    tt.fetch(type, type.to_s)
  end  
  module_function :twitterized_type
end


n = 500000

Benchmark.bm(7) do |x|
  x.report('case statement')  { n.times { |i| Helper1.twitterized_type(:success) } }
  x.report('hash lookup   ')  { n.times { |i| Helper2.twitterized_type(:success) } }
  x.report('hash lookup 2 ')  { n.times { |i| Helper3.twitterized_type(:success) } }
  x.report('hash lookup defined once ')  { n.times { |i| Helper4.twitterized_type(:success) } }
  x.report('hash lookup cached ')  { n.times { |i| Helper4.twitterized_type(:success) } }

  x.report('when not exist: case statement')  { n.times { |i| Helper1.twitterized_type(:non_existent) } }
  x.report('when not exist: hash lookup   ')  { n.times { |i| Helper2.twitterized_type(:non_existent) } }
  x.report('when not exist: hash lookup 2 ')  { n.times { |i| Helper3.twitterized_type(:non_existent) } }
 x.report('when not exist: hash lookup defined once ')  { n.times { |i| Helper4.twitterized_type(:non_existent) } }
  x.report('hash lookup cached ')  { n.times { |i| Helper4.twitterized_type(:non_existent) } }

end