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, 25 insertions, 0 deletions

diff --git a/activesupport/lib/active_support/lazy_load_hooks.rb b/activesupport/lib/active_support/lazy_load_hooks.rb
new file mode 100644
index 0000000000..36acfda524
--- /dev/null
+++ b/activesupport/lib/active_support/lazy_load_hooks.rb
@@ -0,0 +1,25 @@
+module ActiveSupport
+  module LazyLoadHooks
+    def _setup_base_hooks
+      @base_hooks ||= Hash.new {|h,k| h[k] = [] }
+      @base ||= {}
+    end
+
+    def base_hook(name = nil, &block)
+      _setup_base_hooks
+
+      if base = @base[name]
+        base.instance_eval(&block)
+      else
+        @base_hooks[name] << block
+      end
+    end
+
+    def run_base_hooks(base, name = nil)
+      _setup_base_hooks
+
+      @base_hooks[name].each { |hook| base.instance_eval(&hook) } if @base_hooks
+      @base[name] = base
+    end
+  end
+end
\ No newline at end of file