Extremely simple cache method system for ruby objects

output.txt

Class cache
Output => -3400421267002374593 :: -1797544009241115821 :: 4
  0.000000   0.000000   0.000000 (  4.000965)
Output => -3400421267002374593 :: -1797544009241115821 :: 4
  0.000000   0.000000   0.000000 (  0.000068)
Output => -3400421267002374593 :: -1797544009241115821 :: 4
  0.000000   0.000000   0.000000 (  0.000069)
Output => -3400421267002374593 :: -2043295954666096465 :: 6
  0.000000   0.000000   0.000000 (  6.001122)
Output => -3400421267002374593 :: -2043295954666096465 :: 6
  0.000000   0.000000   0.000000 (  0.000061)
Output => -3400421267002374593 :: -2043295954666096465 :: 6
  0.000000   0.000000   0.000000 (  0.000080)

Instance cache
Output => -4338026385995737381 :: 1636374567177026755 :: 3
  0.000000   0.000000   0.000000 (  3.001247)
Output => -4338026385995737381 :: 1636374567177026755 :: 3
  0.000000   0.010000   0.010000 (  0.000084)
Output => -4338026385995737381 :: 1636374567177026755 :: 3
  0.000000   0.000000   0.000000 (  0.000070)
Output => -4338026385995737381 :: -129914481430179661 :: 5
  0.000000   0.000000   0.000000 (  5.001130)
Output => -4338026385995737381 :: -129914481430179661 :: 5
  0.000000   0.000000   0.000000 (  0.000087)
Output => -4338026385995737381 :: -129914481430179661 :: 5
  0.000000   0.000000   0.000000 (  0.000075)

simple_cache.rb

# -*- encoding: utf-8 -*-

module SimpleCache
  def self.included(base)
    base.class_eval do
      def self.cache
        @_class_cache ||= Pool.new(self)
      end

      def cache
        @_instance_cache ||= Pool.new(self)
      end
    end
  end

  class Pool
    def initialize(host)
      @host = host
      @pool = Hash.new
    end

    def method_missing(method, *args)
      args_key = Marshal.dump(args)
      key = "#{method}__#{args_key.to_s}"

      @pool[key] ||= @host.send(method.to_sym, *args)
    end
  end
end

test.rb

# -*- encoding: utf-8 -*-

require File.expand_path(File.dirname(__FILE__) + '/simple_cache')
require 'benchmark'

class Output
  attr_reader :time, :owner

  def initialize(time, owner)
    @time = time
    @owner = owner
  end

  def to_s(*)
    "Output => #{owner} :: #{hash} :: #{time}"
  end
end

class Test
  include SimpleCache

  def self.expensive(time = 4)
    sleep time

    Output.new(time, hash)
  end

  def expensive(time = 3)
    sleep time

    Output.new(time, hash)
  end
end

puts "Class cache"
puts Benchmark.measure { puts Test.cache.expensive }
puts Benchmark.measure { puts Test.cache.expensive }
puts Benchmark.measure { puts Test.cache.expensive }
puts Benchmark.measure { puts Test.cache.expensive(6) }
puts Benchmark.measure { puts Test.cache.expensive(6) }
puts Benchmark.measure { puts Test.cache.expensive(6) }

puts "\n"
puts "Instance cache"
t = Test.new
puts Benchmark.measure { puts t.cache.expensive }
puts Benchmark.measure { puts t.cache.expensive }
puts Benchmark.measure { puts t.cache.expensive }
puts Benchmark.measure { puts t.cache.expensive(5) }
puts Benchmark.measure { puts t.cache.expensive(5) }
puts Benchmark.measure { puts t.cache.expensive(5) }