splitwise / cacheable

A quick way to make cacheable method calls in Ruby
MIT License
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Memoizaiton for consequent method calls on the same object #15

Open Envek opened 11 months ago

Envek commented 11 months ago

As far as I can tell from source code there is no memoization of fetched cache value for later cached method calls on the same object. Is it on purpose?

To be honest, this behavior seems to be pretty surprising:

class Foo
  include Cacheable
  cacheable :bar

  def bar
    "foo"
  end
end

foo = Foo.new

foo.bar # cache read and deserialization
foo.bar # cache read and deserialization
foo.bar # cache read and deserialization

Context: recently I saw a Rails app in the wild that cached some ActiveRecord model methods that in turn returned another ActiveRecord objects. And some places got terribly slow due to dozens of repeated calls to retrieve and deserialize which is especially slow and compute-intensive for AR objects, see this blog post for details (and yes, I know that doing so is a bad idea per se). So I had to get rid of cacheable in favor of pure memoization or manual caching with following memoization.

mgod commented 11 months ago

You should be able to add your own cache adapter based on the :memory adapter that uses memoization and falls back on some other cache like the Rails.cache.