instrument_template_resolver.rb

if Rails.env.development?
  ActionView::PathSet.class_eval do
    private
    alias_method :__find_all, :_find_all
    def _find_all(*args)
      t1 = Time.now
      __find_all(*args)
    ensure
      t2 = Time.now
      Thread.current["find_template_time"] ||= 0
      Thread.current["find_template_time"] += (t2 - t1) * 1000
    end
  end

  module TemplateResolverControllerRuntime
    extend ActiveSupport::Concern

    private

    def process_action(action, *args)
      Thread.current["find_template_time"] = 0
      super
    end

    def append_info_to_payload(payload)
      super
      payload[:find_template_time] = Thread.current["find_template_time"] || 0
      Thread.current["find_template_time"] = 0
    end

    module ClassMethods # :nodoc:
      def log_process_action(payload)
        messages, find_template_time = super, payload[:find_template_time]
        messages << ("Resolver: %.1fms" % find_template_time.to_f) if find_template_time
        messages
      end
    end
  end

  ActiveSupport.on_load(:action_controller) do
    include TemplateResolverControllerRuntime
  end
end