High performant source reloader
This class acts as Rack middleware.
What makes it especially suited for use in a production environment is that any file will only be checked once and there will only be made one system call stat(2).
Please note that this will not reload files in the background, it does so only when actively called.
It is performing a check/reload cycle at the start of every request, but also respects a cool down time, during which nothing will be done.
# File lib/rack/reloader.rb, line 23 def initialize(app, cooldown = 10, backend = Stat) @app = app @cooldown = cooldown @last = (Time.now - cooldown) @cache = {} @mtimes = {} extend backend end
# File lib/rack/reloader.rb, line 33 def call(env) if @cooldown and Time.now > @last + @cooldown if Thread.list.size > 1 Thread.exclusive{ reload! } else reload! end @last = Time.now end @app.call(env) end
# File lib/rack/reloader.rb, line 47 def reload!(stderr = $stderr) rotation do |file, mtime| previous_mtime = @mtimes[file] ||= mtime safe_load(file, mtime, stderr) if mtime > previous_mtime end end
A safe Kernel::load, issuing the hooks depending on the results
# File lib/rack/reloader.rb, line 55 def safe_load(file, mtime, stderr = $stderr) load(file) stderr.puts "#{self.class}: reloaded `#{file}'" file rescue LoadError, SyntaxError => ex stderr.puts ex ensure @mtimes[file] = mtime end