HTTP Streaming on Heroku with Rails 3.1 & Unicorn

Inspired by the RailsCast on HTTP Streaming, I've decided to turn it on on my server. However, the listen 3000 :tcp_nopush => false line that Ryan suggests adding to my unicorn.rb doesn't play well with Heroku (they don't let you specify a port). Is streaming supported on Her开发者_开发问答oku, and how do I turn it on?

Heroku tells your application what port to listen on via the environment variable PORT. Check for this environment variable in your unicorn.rb.

port = ENV["PORT"].to_i
listen port, :tcp_nopush => false