require 'thread' module Rack # Rack::Reloader checks on every request, but at most every +secs+ # seconds, if a file loaded changed, and reloads it, logging to # rack.errors. # # It is recommended you use ShowExceptions to catch SyntaxErrors etc. class Reloader def initialize(app, secs=10) @app = app @secs = secs # reload every @secs seconds max @last = Time.now end def call(env) if Time.now > @last + @secs Thread.exclusive { reload!(env['rack.errors']) @last = Time.now } end @app.call(env) end def reload!(stderr=$stderr) need_reload = $LOADED_FEATURES.find_all { |loaded| begin if loaded =~ /\A[.\/]/ # absolute filename or 1.9 abs = loaded else abs = $LOAD_PATH.map { |path| ::File.join(path, loaded) }. find { |file| ::File.exist? file } end if abs ::File.mtime(abs) > @last - @secs rescue false else false end end } need_reload.each { |l| $LOADED_FEATURES.delete l } need_reload.each { |to_load| begin if require to_load stderr.puts "#{self.class}: reloaded `#{to_load}'" end rescue LoadError, SyntaxError => e raise e # Possibly ShowExceptions end } stderr.flush need_reload end end end