helper for the resque workers to interact with redis

worker_helper.rb

module WorkerHelper
  REDIS_EXPIRY_TIME = 20.minutes

  def logger
    unless @logger
      @logger = Logger.new(STDOUT)
      @logger.formatter = proc do |severity, datetime, _progname, msg|
        "[#{severity}] #{datetime}: #{msg}\n"
      end
    end
    @logger
  end

  # @yield The work to do asynchronously
  # @param [String, #read] channel the channel to subscribe to
  # @param [String, #read] ok_msg the message to wait for
  # @return [Thread] a thread that is waiting for the ok message from the given block
  def thread_sub(channel, ok_msg = channel)
    Thread.new do
      redis.subscribe(channel) do |on|
        on.subscribe { yield }
        on.message do |_chan, msg|
          fail(msg) unless msg == ok_msg
          redis.unsubscribe
        end
      end
    end
  end

  def wait_for(jobs)
    jobs.each(&:join)
  end

  def publish(channel, msg = channel)
    redis.publish channel, msg
  end

  def store(key, data)
    redis.setex key, WorkerHelper::REDIS_EXPIRY_TIME, data
  end

  def redis
    @redis ||= Redis::Store.new
  end

  def enqueue(job, *params)
    run_queue_immediately? ? job.perform(*params) : Resque.enqueue(job, *params)
  end

  private

  def run_queue_immediately?
    Rails.env == 'test' || ENV['RUN_QUEUE_IMMEDIATELY']
  end
end