# class Rack::Reloader

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.

### Public Class Methods

new(app, cooldown = 10, backend = Stat) click to toggle source

    # File lib/rack/reloader.rb, line 27
    def initialize(app, cooldown = 10, backend = Stat)
      @app = app
      @cooldown = cooldown
      @last = (Time.now - cooldown)
      @cache = {}
      @mtimes = {}
      @reload_mutex = Mutex.new

      extend backend
    end

### Public Instance Methods

call(env) click to toggle source

    # File lib/rack/reloader.rb, line 38
    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) click to toggle source

    # File lib/rack/reloader.rb, line 52
    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) click to toggle source

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

    # File lib/rack/reloader.rb, line 60
    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