example_worker.rb

class ExampleWorker
  extend ResqueHelper
  
  @queue = :example
  
  def self.perform(user_id)
    logger.info("Checking to see if there are any other jobs queued for user #{user_id}")
    return if already_queued? { |args| args.first == user_id }
  
    # do something expensive...
  end
end