Module: WardenOpenidBearer::CacheMixin

Included in:
DiscoveredConfig, Strategy
Defined in:
lib/warden_openid_bearer/cache_mixin.rb

Overview

We don’t need an overengineered approach based on the Rails cache. No, really.

Instance Method Summary collapse

Instance Method Details

#cached_by(*keys, &do_it) ⇒ Object 



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# File 'lib/warden_openid_bearer/cache_mixin.rb', line 7

def cached_by(*keys, &do_it)
  @__cache_mixin__cache ||= {}

  caller_method = caller(1..1).first[/`.*'/][1..-2]
  keys.unshift(caller_method)

  first_keys = keys.slice!(0, keys.length - 1).join("|")
  last_key = keys[0]

  last_key_is_value_type = last_key.is_a? String
  cache = @__cache_mixin__cache[first_keys] ||= if last_key_is_value_type
            {}
          else
            # Use the ::ObjectSpace::WeakMap private API, because the
            # endeavor of reinventing weak maps on top of (public)
            # WeakRef's would be called an inversion of abstraction and
            # would be considered harmful. Sue me (I have unit tests).
            ::ObjectSpace::WeakMap.new
          end

  now = Time.now

  if (cached = cache[last_key])
    unless respond_to?(:cache_timeout) && now - cached[:fetched_at] > cache_timeout
      return cached[:payload]
    end
  end

  retval = do_it.call
  cache[last_key] = {payload: retval, fetched_at: now}
  retval
end