double_method

double_method.rb

require 'benchmark'
require 'active_support'

module Hello
  extend ActiveSupport::Concern

  BENCH_ITERS = 1_000_000

  included do
    double_method :hello_double, :hello
    alias hello_alias hello
    alias_method :hello_alias_method, :hello
    define_method :hello_define_method, instance_method(:hello)
  end

  module ClassMethods
    def double_method(double_name, orig_name) # <----------------- all this gist about this guy
      self.class_eval <<-RUBY
        def #{double_name}(*args, &block)
          #{orig_name}(*args, &block)
        end
      RUBY
    end
  end

  def hello
    'hello world'
  end

  def test
    puts "Test for #{self.class.to_s}"
    puts "  alias:          #{hello_alias}"
    puts "  alias_method:   #{hello_alias_method}"
    puts "  define_method:  #{hello_define_method}"
    puts "  double_method:  #{hello_double}"
    self
  end

  def benchmark
    puts "Benchmark for #{self.class.to_s}"
    bench_orig          = Benchmark.measure { BENCH_ITERS.times { hello } }
    bench_alias         = Benchmark.measure { BENCH_ITERS.times { hello_alias } }
    bench_alias_method  = Benchmark.measure { BENCH_ITERS.times { hello_alias_method } }
    bench_define_method = Benchmark.measure { BENCH_ITERS.times { hello_define_method } }
    bench_double        = Benchmark.measure { BENCH_ITERS.times { hello_double } }
    puts "  original:       #{bench_orig}"
    puts "  alias:          #{bench_alias}"
    puts "  alias_method:   #{bench_alias_method}"
    puts "  define_method:  #{bench_define_method}"
    puts "  double_method:  #{bench_double}"
    self
  end
end

class A
  include Hello
end

class B < A
  include Hello

  def hello
    'overridden hello'
  end
end

A.new.test.benchmark
B.new.test.benchmark

# Example output:
#
# Test for A
#   alias:          hello world
#   alias_method:   hello world
#   define_method:  hello world
#   double_method:  hello world
# Benchmark for A
#   original:         0.150000   0.000000   0.150000 (  0.144486)
#   alias:            0.140000   0.000000   0.140000 (  0.144081)
#   alias_method:     0.140000   0.000000   0.140000 (  0.141664)
#   define_method:    0.150000   0.000000   0.150000 (  0.141005)
#   double_method:    0.260000   0.000000   0.260000 (  0.268172)
# Test for B
#   alias:          hello world
#   alias_method:   hello world
#   define_method:  hello world
#   double_method:  overridden hello
# Benchmark for B
#   original:         0.150000   0.000000   0.150000 (  0.145959)
#   alias:            0.140000   0.000000   0.140000 (  0.143349)
#   alias_method:     0.150000   0.000000   0.150000 (  0.147040)
#   define_method:    0.150000   0.000000   0.150000 (  0.146973)
#   double_method:    0.260000   0.000000   0.260000 (  0.262837)