Look for already existing Delayed::Job

dj.rb

class Delayed::Job
  scope :waiting, lambda{where(failed_at: nil).where(locked_at: nil)}

  def self.include?(object, method_name = nil, queue = :default)
    object_class = object.respond_to?(:id) ? object.class : object
    object_id = object.respond_to?(:id) && object.id
    waiting.where(queue: queue).detect do |job|
      o = job.payload_object.object
      m = method_name.present? ? job.payload_object.method_name : nil
      o_class = o.respond_to?(:id) ? o.class : o
      o_id = o.respond_to?(:id) && o.id

      o_class == object_class &&
        o_id == object_id &&
        m == method_name
    end
  end

  # quick and dirty
  def self.find_by_object(object, queue = :default)
    where(queue: queue).where("handler like '%#{object.class.name}%id: #{object.id}%'").first
  end
end