Class: Rack::Reloader

Inherits:
Object
  • Object
show all
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.

Defined Under Namespace

Modules: Stat

Instance Method Summary collapse

Constructor Details

#initialize(app, cooldown = 10, backend = Stat) ⇒ Reloader

Returns a new instance of Reloader.

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# 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) ⇒ Object 

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# 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) ⇒ Object 

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# 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) ⇒ Object

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

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# 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