debouncer.rb

module DeBouncer
  def self.extened(base)
    class << base
      @deboucner_module = nil
    end
  end

  def debounce(method_name, time)
    if @debouncer_module
      @debouncer_module.create_debouncer(method_name, time)
    else
      @debouncer_module = Module.new do
        def self.create_debouncer(method_name, time)
          define_method(method_name) do |*args, &block|
            last_invoked_at = instance_variable_get(:"@#{method_name}_last_invoked_at")
            if !last_invoked_at || (Time.now - last_invoked_at)*1000 > time
              instance_variable_set(:"@#{method_name}_last_invoked_at", Time.now)
              self.instance_variable_set(:"@#{method_name}_cached_result",
                super(*args, &block)
              )
            else
              instance_variable_get(:"@#{method_name}_cached_result")
            end
          end
        end
      end
      @debouncer_module.create_debouncer(method_name, time)
      prepend(@debouncer_module)
    end
  end
end

class Foo
  extend DeBouncer
  def initialize
    @i = 0
  end

  def hello
    yield Time.now
  end

  def wow
    puts "********** Calling wow #{Time.now}"
    @i += 1
  end
  debounce :hello, 4000
  debounce :wow, 4000
end