[ANN] rev 0.3.0: Now with filesystem monitoring

ruby-talk
1

Rev is a high-performance event library for Ruby, providing event loops for
monitoring network, timer, and now filesystem events. Rev is based on the
libev C library.

http://github.com/tarcieri/rev/

Rev 0.3.0 provides some bugfixes and performance improvements as well as a
slew of new features, including many new extensions to existing APIs that
provide for better integration with the Ruby environment, and a new
filesystem monitoring API built on the facilities provided by the libev
event library, including inotify support on Linux.

The new StatWatcher API allows you to monitor any file or directory for
changes and receive events when changes occur:

-- snip --

class MyStatWatcher < Rev::StatWatcher
  def on_change
    begin
      puts "#{path} has new status #{File.stat(path).inspect}"
    rescue Errno::ENOENT
      puts "#{path} was deleted"
    end
  end
end

watcher = MyStatWatcher.new "interesting/file"
watcher.attach Rev::Loop.default
Rev::Loop.default.run

-- snip --

I know there are many gems already available to provide filesystem
monitoring, such as directory_watcher (
http://github.com/TwP/directory_watcher/tree/master), and that EventMachine
already provides EM.watch_file, but for the Rev users out there, you now
have the same capabilities with Rev's asynchronous event loops.

···

--
Tony Arcieri
Medioh/Nagravision

2

Awesome work Tony!

I for one welcome our new event-loop driven file notification
overlords. Thanks for adding inotify support in an elegant manner.

Blessings,
TwP

···

On Sat, Aug 29, 2009 at 12:12 AM, Tony Arcieri<tony@medioh.com> wrote:

Rev is a high-performance event library for Ruby, providing event loops for
monitoring network, timer, and now filesystem events. Rev is based on the
libev C library.

http://github.com/tarcieri/rev/

Rev 0.3.0 provides some bugfixes and performance improvements as well as a
slew of new features, including many new extensions to existing APIs that
provide for better integration with the Ruby environment, and a new
filesystem monitoring API built on the facilities provided by the libev
event library, including inotify support on Linux.

3

Hi Tony

Does this use fsevents on Mac OSX?

Thanks,
Rob

···

On Sat, Aug 29, 2009 at 2:12 AM, Tony Arcieri <tony@medioh.com> wrote:

Rev is a high-performance event library for Ruby, providing event loops for
monitoring network, timer, and now filesystem events. Rev is based on the
libev C library.

http://github.com/tarcieri/rev/

Rev 0.3.0 provides some bugfixes and performance improvements as well as a
slew of new features, including many new extensions to existing APIs that
provide for better integration with the Ruby environment, and a new
filesystem monitoring API built on the facilities provided by the libev
event library, including inotify support on Linux.

The new StatWatcher API allows you to monitor any file or directory for
changes and receive events when changes occur:

-- snip --

class MyStatWatcher < Rev::StatWatcher
def on_change
   begin
     puts "#{path} has new status #{File.stat(path).inspect}"
   rescue Errno::ENOENT
     puts "#{path} was deleted"
   end
end
end

watcher = MyStatWatcher.new "interesting/file"
watcher.attach Rev::Loop.default
Rev::Loop.default.run

-- snip --

I know there are many gems already available to provide filesystem
monitoring, such as directory_watcher (
http://github.com/TwP/directory_watcher/tree/master\), and that
EventMachine
already provides EM.watch_file, but for the Rev users out there, you now
have the same capabilities with Rev's asynchronous event loops.

--
Tony Arcieri
Medioh/Nagravision

4

Unfortunately on all platforms besides Linux it's just using stat()
periodically, to my knowledge.

If you are interested in having other syscalls supported for filesystem
monitoring, I can ask on the libev mailing list.

···

On Mon, Aug 31, 2009 at 10:48 AM, Rob Sanheim <rsanheim@gmail.com> wrote:

Hi Tony

Does this use fsevents on Mac OSX?

--
Tony Arcieri
Medioh/Nagravision