ruby-grape / grape / 26468366305

97%

master: 97%

Pull #2740

github

Lazy-allocate `@api_class` and `@point_in_time_copies` on InheritableSetting

`InheritableSetting#initialize` used to eagerly allocate both fields up
front. Neither is touched on most settings layers:

- `@api_class` is only written by external code (e.g. plugins) via
  `setting.api_class[:k] = v`; nothing in `lib/` writes to it.
- `@point_in_time_copies` only fills up on settings that get cloned via
  `point_in_time_copy` — typically the API-class-level setting, not the
  per-endpoint copies that make up the bulk of allocations at boot.

Switch both to memoizing readers (`@x ||= …`), drop the eager init, and
rewrite the `inherit_from` propagation loop to access the ivar directly
with `&.each` so the no-copies path doesn't allocate the Array just to
iterate zero elements.

Measured against master:

  Grape::Util::InheritableSetting.new × 100
    before: 1600 objects, 183.6 kB
    after:  1400 objects, 164.1 kB   (-11%)

Stacks with #2739 (lazy `@new_values`) for compounded boot-time savings.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

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