BrowserChannel Ruby Server

An event-driven server for Google Closure Library's goog.BrowserChannel class.

Getting Started

Step 1

Ensure you have a modern Ruby and RubyGems. Version 1.8.6 and higher should work. Run:

gem install thin closure json
thin start

Step 2

Open your web browser and continue from there. Check the thin log for the proper port. It's most likely:

http://localhost:3000/

Getting to Production

The browser is started by attaching a handler to a channel. The channel then connects with a server. The handler is your implementation.

var handler = new goog.net.BrowserChannel.Handler();
handler.channelOpened = function(channel) {
  // fire off a message immediately after connect
  channel.sendMap({message:'data'});
};
handler.channelHandleArray = function(x, data) {
  // messages from the server arrive here
  alert(data[0].message);
};

channel = new goog.net.BrowserChannel();
channel.setHandler(handler);
channel.connect('demo.test', 'demo.channel');

The server is a Rack application for the thin server. Other Rack servers do not support event-driven multi chunk responses. Thin also enables use of the epoll/kqueue interface which allows for tens of thousands of open connections. Expect 500-1000 requests per second on a single core of modern hardware.

# for config.ru
require 'browser_channel'
require 'browser_test_channel'
map '/demo.channel' do
  run BrowserChannel::Server.new, :handler => MyHandler
end
map '/demo.test' do
  run BrowserTestChannel::Server.new
end

Just like the browser side, there's a handler for your implementation.

class MyHandler < BrowserChanner::Handler
  # this is an echo server
  def call post_data
    requests = decode_post_data post_data
    requests.each { |r| @session << [r] }
  end
  # called when channel session is final
  def terminate
  end
end

Be sure not to deploy the Closure Script build tool or debug tools like Rack::Reloader. These will severely affect performance and security. Check your middleware if you're not seeing the benchmarks you expect.