StreamingController

streaming_controller.rb

class StreamingController < ApplicationController

   include ActionController::Live

   before_filter :require_user

   def index
     Rails.logger.info "streaming#index"
     ActiveRecord::Base.connection_pool.release_connection # current_user already loaded in before filter

     response.headers["Content-Type"] = "text/event-stream"


     response.stream.write "retry: 2000\n\n" # every 2 seconds


     #http://ngauthier.com/2013/02/rails-4-sse-notify-listen.html
     #http://stackoverflow.com/questions/16405520/postgres-listen-notify-rails
     pool = ActiveRecord::Base.connection_pool
     conn = pool.checkout
     channels =  [ 'chat', "user_#{current_user.id}" ]
     channels += current_user.played_games.map{|g| "game_#{g.id}"}

     channels.each do |channel|
      conn.execute "LISTEN #{channel}"
     end

     loop do

       response.stream.write "event: status\n"
       response.stream.write "data: " + {threads: Thread.list.count, db_pool: pool.size, db_cons: pool.connections.size, t: Time.now.strftime("%H:%M:%S")}.to_json + "\n\n"

       conn.raw_connection.wait_for_notify(2) do |event, pid, message|
         hash = JSON.parse(message)
         response.stream.write "event: #{hash['event']}\n"
         response.stream.write "data: #{message}\n\n"
       end

     end

   rescue IOError => e
     Rails.logger.info "Got an exception " + e.inspect
   ensure
     Rails.logger.info "ensuring stuff..."
     if conn
       conn.execute "UNLISTEN *"  # unlisten to all channels
       pool.checkin conn
     end
     #needed? ActiveRecord::Base.clear_active_connections!
     response.stream.close
     Rails.logger.info "...finished ensuring stuff."
   end


end