Make many parts of Rails lazy. In order to facilitate this,

add lazy_load_hooks.rb, which allows us to declare code that
should be run at some later time. For instance, this allows
us to defer requiring ActiveRecord::Base at boot time purely
to apply configuration. Instead, we register a hook that should
apply configuration once ActiveRecord::Base is loaded.

With these changes, brings down total boot time of a
new app to 300ms in production and 400ms in dev.

TODO: rename base_hook

1 files changed, 5 insertions, 3 deletions

diff --git a/activesupport/lib/active_support/railtie.rb b/activesupport/lib/active_support/railtie.rb
index 58d11585ba..d2c13e030d 100644
--- a/activesupport/lib/active_support/railtie.rb
+++ b/activesupport/lib/active_support/railtie.rb
@@ -37,10 +37,12 @@ module I18n
     config.i18n.load_path = []
 
     initializer "i18n.initialize" do
-      require 'active_support/i18n'
-
-      ActionDispatch::Callbacks.to_prepare do
+      ActiveSupport.base_hook(:i18n) do
         I18n.reload!
+
+        ActionDispatch::Callbacks.to_prepare do
+          I18n.reload!
+        end
       end
     end