Delay worker with delay handler and Rails adapter for Sneakers

delay_worker.rb

#
# enqueue with following parameters hash:
# - headers
#   - work_at - time of execution
#   - work_queue - destination queue for actually doing the work
#
class DelayWorker
  include Sneakers::Worker
  from_queue :treadmill, { handler: Sneakers::Handlers::Delay }

  def work(msg)
    # let the handler do all the work
    reject!
  end
end

sneakers_adapter.rb

require 'sneakers'
require 'thread'

module ActiveJob
  module QueueAdapters
    # == Sneakers adapter for Active Job
    #
    # A high-performance RabbitMQ background processing framework for Ruby.
    # Sneakers is being used in production for both I/O and CPU intensive
    # workloads, and have achieved the goals of high-performance and
    # 0-maintenance, as designed.
    #
    # Read more about Sneakers {here}[https://github.com/jondot/sneakers].
    #
    # To use Sneakers set the queue_adapter config to +:sneakers+.
    #
    #   Rails.application.config.active_job.queue_adapter = :sneakers
    class SneakersAdapter
      @monitor = Monitor.new

      class << self
        def enqueue(job) #:nodoc:
          @monitor.synchronize do
            JobWrapper.from_queue job.queue_name
            JobWrapper.enqueue ActiveSupport::JSON.encode(job.serialize)
          end
        end

        def enqueue_at(job, timestamp) #:nodoc:
          @monitor.synchronize do
            JobWrapper.from_queue :treadmill
            JobWrapper.enqueue ActiveSupport::JSON.encode(job.serialize), headers: { work_at: timestamp, work_queue: job.queue_name }
          end
        end
      end

      class JobWrapper #:nodoc:
        include Sneakers::Worker
        from_queue 'default'

        def work(msg)
          job_data = ActiveSupport::JSON.decode(msg)
          Base.execute job_data
          ack!
        end
      end
    end
  end
end