gistfile1.rb

require 'benchmark'

class InfoDesk
  def flights
    puts "flights"
  end

  def trains
    puts "trains"
  end

  def hotels
    puts "hotels"
  end
end

class Sign
  def initialize
    @desk = InfoDesk.new
    @methods = @desk.class.instance_methods(false)
  end

  def method_missing(name, *args)
    return super unless @desk.respond_to? name

    return "Out for lunch" if false
    @desk.send(name, *args)
  end

  def respond_to_missing?(method, include_private)
     @methods.include? method || super
  end
end

class Sign2 < Sign
  def respond_to_missing?(method, include_private)
    false
  end

  def respond_to?(method)
    @desk.respond_to?(method) || super
  end
end


s = Sign.new
s2 = Sign2.new

Benchmark.bmbm do |x|
  x.report("respond_to_missing?") { 999999.times{ s.respond_to? :trains } }
  x.report("respond_to?") { 999999.times{ s2.respond_to? :trains } }
end

# RUBY 1.9.2-p0
#lite@lite-debian:~$ ruby respond.rb
#Rehearsal -------------------------------------------------------
#respond_to_missing?   0.800000   0.000000   0.800000 (  0.835451)
#respond_to?           0.480000   0.000000   0.480000 (  0.532853)
#---------------------------------------------- total: 1.280000sec
#
#                          user     system      total        real
#respond_to_missing?   0.810000   0.000000   0.810000 (  0.880678)
#respond_to?           0.470000   0.000000   0.470000 (  0.497812)

# RUBY 1.8.7-p302
#lite@lite-debian:~$ ruby respond.rb
#Rehearsal -------------------------------------------------------
#respond_to_missing?   0.440000   0.000000   0.440000 (  0.443771)
#respond_to?           0.970000   0.000000   0.970000 (  0.967982)
#---------------------------------------------- total: 1.410000sec
#
#                          user     system      total        real
#respond_to_missing?   0.430000   0.000000   0.430000 (  0.437821)
#respond_to?           0.940000   0.000000   0.940000 (  0.940762)

# JRUBY 1.5.5
#Rehearsal -------------------------------------------------------
#respond_to_missing?   0.573000   0.000000   0.573000 (  0.475000)
#respond_to?           0.594000   0.000000   0.594000 (  0.595000)
#---------------------------------------------- total: 1.167000sec
#
#                          user     system      total        real
#respond_to_missing?   0.152000   0.000000   0.152000 (  0.152000)
#respond_to?           0.283000   0.000000   0.283000 (  0.283000)

# rbx rubinius 1.2.4dev
#Rehearsal -------------------------------------------------------
#respond_to_missing?   0.252015   0.000000   0.252015 (  0.251117)
#respond_to?           0.264016   0.000000   0.264016 (  0.265055)
#---------------------------------------------- total: 0.516031sec
#
#                          user     system      total        real
#respond_to_missing?   0.200012   0.000000   0.200012 (  0.198520)
#respond_to?           0.220014   0.000000   0.220014 (  0.218376)