bayeux.rack

Bayeux (COMET or long-polling) protocol server as a Sinatra application. Light weight and high scalability are achieved by using the asynchronous Rack extensions added to Thin by async_sinatra.

Because it uses async_sinatra, which uses EventMachine, it won’t work in Passenger. Sorry about that, but Apache doesn’t really like long-polling anyhow. Use Thin.

You can see a video presentation of this code here: www.youtube.com/watch?v=Bhj9QOfNd4c

Usage

See github.com/cjheath/jquery.comet for an example of usage and for a COMET client in Javascript.

class MyServer < Bayeux
  configure do
    # The default :public is inside the Bayeux gem
    set :public, File.dirname(__FILE__)
  end

  def deliver message
    case channel_name = message['channel']
    when '/my/interesting/channel'

data = message if data == ‘ping’ publish :channel => channel_name, :data => ‘pong’ else super end

else

super

    end
  end
end

Installing

gem install bayeux-rack

License

The MIT license.

Developing

Fork on github github.com/cjheath/bayeux-rack or just clone to play:

git clone git://github.com/cjheath/bayeux-rack.git

Patches welcome! Fork and send a pull request. Please follow coding conventions already in use. Please use jslint if you can. There are currently no warnings, please keep it that way.

Status

Current release has a happy path (working ok). Significant drawbacks to be fixed are:

• Server-side timeout of long-polls to avoid possible loss of sent messages

• Detecting multiple connections (tabs?) from the same browser, to fall back to callback polling.