ActiveRecord extension to cache the result of a compute-intensive method inside a store.

cachemire.rb

module Cachemire
  extend ActiveSupport::Concern

  module ClassMethods
    def cache_method(name, &block)
      store_accessor :cache, name
      instance_eval do
        define_method name, &cache_wrap(&block)
      end
    end

    private
    def cache_wrap(&block)
      -> do
        unless value = super()
          value = JSON.dump(instance_eval(&block))
          send "#{__method__}=", value
          save if persisted?
        end
        YAML.load value
      end
    end
  end
end

ActiveRecord::Base.send(:include, Cachemire)

world.rb

class Wolrd < ActiveRecord::Base
  cache_method :get_population_count do
    # Intense stuff...
  end
end

Yo voici une autre implémentation possible. C'est n'a pas exactement le même comportement par contre: https://gist.github.com/phildionne/6728341