# File lib/nanoc/cli/commands/compile.rb, line 290
      def start
        Nanoc::NotificationCenter.on(:compilation_started) do |rep|
          @rep_times[rep.raw_path] = Time.now
        end
        Nanoc::NotificationCenter.on(:compilation_ended) do |rep|
          @rep_times[rep.raw_path] = Time.now - @rep_times[rep.raw_path]
        end
        Nanoc::NotificationCenter.on(:rep_written) do |rep, path, is_created, is_modified|
          action = (is_created ? :create : (is_modified ? :update : :identical))
          level  = (is_created ? :high   : (is_modified ? :high   : :low))
          duration = Time.now - @rep_times[rep.raw_path] if @rep_times[rep.raw_path]
          Nanoc::CLI::Logger.instance.file(level, action, path, duration)
        end
      end