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.

Namespace
Methods
C
N
R
S
Class Public methods
new(app, cooldown = 10, backend = Stat)
# File lib/rack/reloader.rb, line 23
def initialize(app, cooldown = 10, backend = Stat)
  @app = app
  @cooldown = cooldown
  @last = (Time.now - cooldown)
  @cache = {}
  @mtimes = {}
  @reload_mutex = Mutex.new

  extend backend
end
Instance Public methods
call(env)
# File lib/rack/reloader.rb, line 34
def call(env)
  if @cooldown and Time.now > @last + @cooldown
    if Thread.list.size > 1
      @reload_mutex.synchronize{ reload! }
    else
      reload!
    end

    @last = Time.now
  end

  @app.call(env)
end
reload!(stderr = $stderr)
# File lib/rack/reloader.rb, line 48
def reload!(stderr = $stderr)
  rotation do |file, mtime|
    previous_mtime = @mtimes[file] ||= mtime
    safe_load(file, mtime, stderr) if mtime > previous_mtime
  end
end
safe_load(file, mtime, stderr = $stderr)

A safe Kernel::load, issuing the hooks depending on the results

# File lib/rack/reloader.rb, line 56
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