gistfile1.rb

# http://blog.uu59.org/2011-10-03-sinatra-stream.html

require "rubygems"
require "sinatra"

set :server, :thin # 注: :keep_openが使えるのはイベントベースのサーバだけなのでthinを明示的に指定してる
connections = []

get '/' do
 # keep stream open
 stream(:keep_open) { |out| connections << out }
end

post '/' do
 # write to all open streams
 connections.each { |out| out << params[:message] << "\n" }
 "message sent"
end