gistfile1.txt

require 'rubygems'
require 'redis'
require 'json'
require 'eventmachine'

class RedisLoop
  class << self
    attr_accessor :queues
    def start(opts={}, &blk)
      EM.run {
        RedisLoop.queues = []
        interval = opts.delete(:interval) || 0.5
        redis = Redis.new(opts)
        blk.call(redis)
        EM.add_periodic_timer(interval) {
          RedisLoop.queues.each do |q|
            count = 0
            while (count < 5) && (work = redis.lpop(q[0]))
              count += 1
              if Symbol === q[2]
                q[1].__send__(q[2], work)
              else
                q[2].call(work)
              end
            end
          end
        }
      }
    end
  end
end

class RedisAgent
  def subscribe(queue, callback=nil, &blk)
    RedisLoop.queues << [queue.to_s, self, (blk ? blk : callback)]
  end
end

class MyWorker < RedisAgent
  def initialize(redis)
    @redis = redis
    subscribe 'foo' do |work|
      work_on_foo(work)
    end
    
    subscribe 'bar' do |work|
      work_on_bar(work)
    end
  end
  def work_on_foo(work)
     p work
  end
  
  def work_on_bar(work)
     p work
  end
end

RedisLoop.start :host => '127.0.0.1' do |r|
  MyWorker.new(r)
end

# in another process with redis loaded
redis.rpush 'foo', 'some work for foo'
redis.rpush 'bar', 'some work for bar'