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Class: Rack::Reloader

Relationships & Source Files
Namespace Children
Modules:
Stat
Inherits: Object
Defined in: lib/rack/reloader.rb

Overview

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.

Class Method Summary

Instance Method Summary

Constructor Details

.new(app, cooldown = 10, backend = Stat) ⇒ Reloader

[ GitHub ] 

  


# File 'lib/rack/reloader.rb', line 25



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 Method Details



  

    #call(env)  
  

  [ GitHub ]


  

  


# File 'lib/rack/reloader.rb', line 36



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)  
  

  [ GitHub ]


  

  


# File 'lib/rack/reloader.rb', line 50



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


  



  [ GitHub ]


  

  


# File 'lib/rack/reloader.rb', line 58



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