Class: Ramaze::Reloader

Inherits:
Object show all
Includes:
Hooks
Defined in:
lib/ramaze/reloader.rb,
lib/ramaze/reloader/watch_stat.rb,
lib/ramaze/reloader/watch_inotify.rb

Overview

High performant source reloader

This class acts as Rack middleware.

It does not depend on Ramaze itself, but you might have to adjust the Reloader::Hooks module or include your own module to override the hooks. You also might have to set the Log constant.

Currently, it uses RInotify if available and falls back to using File.stat.

Please note that this will not reload files in the background, it does so only when actively called In case of Ramaze 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.

After every reload the OPTIONS hash will be checked for changed options and assigned to the instance, so you may change options during the lifetime of your application.

A number of hooks will be executed during the reload cycle, see Ramaze::ReloaderHooks for more information.

Defined Under Namespace

Modules: Hooks Classes: WatchInotify, WatchStat

Constant Summary collapse

OPTIONS = 
{
  # At most check every n seconds
  # nil/false will never trigger the reload cycle
  # 0 will cycle on every call
  :cooldown => 2,

  # Compiled files cannot be reloaded during runtime
  :ignore => /\.so$/,

  # Run cycle in a Thread.exclusive, by default no threads are used.
  :thread => false,

  # If you assign a block here it will be instance_evaled instead of
  # calling cycle. This allows you to use for example EventMachine for
  # well performing asynchronous cycling.
  :control => nil, # lambda{ cycle },
}

Instance Method Summary collapse

Methods included from Hooks

#after_cycle, #after_safe_load, #after_safe_load_failed, #after_safe_load_succeed, #before_cycle, #before_safe_load

Constructor Details

#initialize(app) ⇒ Reloader

Returns a new instance of Reloader.



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# File 'lib/ramaze/reloader.rb', line 63

def initialize(app)
  @app = app
  @files = {}
  @watcher = Watcher.new
  options_reload
end

Instance Method Details

#call(env) ⇒ Object 



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# File 'lib/ramaze/reloader.rb', line 75

def call(env)
  options_reload

  @watcher.call(@cooldown) do
    if @control
      instance_eval(&@control)
    elsif @thread
      Thread.exclusive{ cycle }
    else
      cycle
    end
  end

  @app.call(env)
end

#cycle ⇒ Object 



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# File 'lib/ramaze/reloader.rb', line 91

def cycle
  before_cycle

  rotation{|file| @watcher.watch(file) }
  @watcher.changed_files{|f| safe_load(f) }

  after_cycle
end

#figure_path(file, paths) ⇒ Object 



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# File 'lib/ramaze/reloader.rb', line 123

def figure_path(file, paths)
  if Pathname.new(file).absolute?
    return File.exist?(file) ? file : nil
  end

  paths.each do |possible_path|
    full_path = File.join(possible_path, file)
    return full_path if File.exist?(full_path)
  end
  nil
end

#options_reload ⇒ Object 



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# File 'lib/ramaze/reloader.rb', line 70

def options_reload
  @cooldown, @ignore, @control, @thread =
    OPTIONS.values_at(:cooldown, :ignore, :control, :thread)
end

#rotation ⇒ Object 



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# File 'lib/ramaze/reloader.rb', line 110

def rotation
  files = [$0, __FILE__, *$LOADED_FEATURES].uniq
  paths = ['./', *$LOAD_PATH].uniq

  files.each do |file|
    next if file =~ @ignore
    if not @files.has_key?(file) and path = figure_path(file, paths)
      @files[file] = path
      yield path
    end
  end
end

#safe_load(file) ⇒ Object

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



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# File 'lib/ramaze/reloader.rb', line 101

def safe_load(file)
  before_safe_load(file)
  load(file)
  after_safe_load_succeed(file)
rescue Object => ex
  Log.error(ex)
  after_safe_load_failed(file, ex)
end