Redis PubSub client with ruby/cool.io (cool.io is a high performance event library for Ruby built on top of libev)

redis_pubsub.rb

require 'rubygems'
require 'cool.io'
require "redis/connection/command_helper"

class RedisPubsub < Cool.io::TCPSocket
  include ::Redis::Connection::CommandHelper
  event_callback :on_subscribe, :on_unsubscribe, :on_message
  attr_accessor :args
    
  def subscribe(*channels)
    @channels = channels
    return unless @connected
    send_subscribe
  end
  
  def send_subscribe
    # puts "redis SUBSCRIBE " + @channels.join(", ")
    write build_command(['SUBSCRIBE'] + @channels)
  end
  
  def on_connect
    @connected = true
    send_subscribe if @channels
  end
    
  def on_read(data)
    val = []
    data.split.each_with_index { |o,i| val << o if i.even? }
    return if val[1].to_s.length <= 0 || !respond_to?("on_#{val[1]}")
    
    # puts "redis on_read #{val}"
    if @args
      send "on_#{val[1]}", val[2..-1], @args
    else 
      send "on_#{val[1]}", val[2..-1]
    end      
  end
end


##################################################################
# simple example

if $0 == __FILE__
  sub = RedisPubsub.connect('localhost', 6379)
  sub.subscribe :first, :second
  sub.on_message do |data|
    channel, msg = data
    puts "#{channel}: #{msg}"
  end

  sub.attach(Cool.io::Loop.default)
  cool.io.run
end