Class: Listen::Adapter::Linux

Inherits:
Base
  • Object
show all
Defined in:
lib/listen/adapter/linux.rb

Overview

Listener implementation for Linux inotify.

See Also:

Constant Summary collapse

OS_REGEXP = 
/linux/i
EVENTS = 
[:recursive, :attrib, :create, :delete, :move, :close_write]
WIKI_URL = 
'https://github.com/guard/listen'\
'/wiki/Increasing-the-amount-of-inotify-watchers'
INOTIFY_LIMIT_MESSAGE = 
<<-EOS.gsub(/^\s*/, '')
  FATAL: Listen error: unable to monitor directories for changes.

  Please head to #{WIKI_URL}
  for information on how to solve this issue.
EOS

Instance Attribute Summary

Attributes inherited from Base

#listener

Instance Method Summary collapse

Methods inherited from Base

#_directories, #_log, #_notify_change, #initialize, local_fs?, #start, usable?

Constructor Details

This class inherits a constructor from Listen::Adapter::Base

Instance Method Details

#_callback ⇒ Object (private) 



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# File 'lib/listen/adapter/linux.rb', line 40

def _callback
  lambda do |event|
    # NOTE: avoid using event.absolute_name since new API
    # will need to have a custom recursion implemented
    # to properly match events to configured directories
    path = Pathname.new(event.watcher.path) + event.name

    _log :debug, "inotify: #{event.name} #{path} (#{event.flags.inspect})"

    if /1|true/ =~ ENV['LISTEN_GEM_SIMULATE_FSEVENT']
      if (event.flags & [:moved_to, :moved_from]) || _dir_event?(event)
        _notify_change(:dir, path.dirname)
      else
        _notify_change(:dir, path)
      end
    else
      next if _skip_event?(event)
      cookie_opts = event.cookie.zero? ? {} : { cookie: event.cookie }
      if _dir_event?(event)
        _notify_change(:dir, path, cookie_opts)
      else
        options = { change: _change(event.flags) }
        _notify_change(:file, path, options.merge(cookie_opts))
      end
    end
  end
end

#_change(event_flags) ⇒ Object (private) 



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# File 'lib/listen/adapter/linux.rb', line 78

def _change(event_flags)
  { modified:   [:attrib, :close_write],
    moved_to:   [:moved_to],
    moved_from: [:moved_from],
    added:      [:create],
    removed:    [:delete] }.each do |change, flags|
    return change unless (flags & event_flags).empty?
  end
  nil
end

#_configure ⇒ Object (private) 



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# File 'lib/listen/adapter/linux.rb', line 23

def _configure
  require 'rb-inotify'
  @worker = INotify::Notifier.new
  _directories.each do |path|
    @worker.watch(path.to_s, *EVENTS, &_callback)
  end
rescue Errno::ENOSPC
  # workaround - Celluloid catches abort and prints nothing
  STDERR.puts INOTIFY_LIMIT_MESSAGE
  STDERR.flush
  abort(INOTIFY_LIMIT_MESSAGE)
end

#_dir_event?(event) ⇒ Boolean (private)

Returns:

  • (Boolean) 


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# File 'lib/listen/adapter/linux.rb', line 89

def _dir_event?(event)
  event.flags.include?(:isdir)
end

#_run ⇒ Object (private) 



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# File 'lib/listen/adapter/linux.rb', line 36

def _run
  @worker.run
end

#_skip_event?(event) ⇒ Boolean (private)

Returns:

  • (Boolean) 


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# File 'lib/listen/adapter/linux.rb', line 68

def _skip_event?(event)
  # Event on root directory
  return true if event.name == ''
  # INotify reports changes to files inside directories as events
  # on the directories themselves too.
  #
  # @see http://linux.die.net/man/7/inotify
  _dir_event?(event) && (event.flags & [:close, :modify]).any?
end