Hello Qu Comrades (all 3 of you),  

I've started working on an implementation of hooks and thought I would get some feedback before going any further.

https://github.com/bkeepers/qu/compare/master…hooks (https://github.com/bkeepers/qu/compare/master...hooks)

To summarize the major changes: Jobs must now extend Qu::Job. This is something I debated about a lot in the initial implementation of Qu. I initially implemented it as a subclass of Qu::Job, but then decided follow Resque and make jobs simply a class with a perform class method for simplicity's sake. I have since changed my mind and think there's a lot of power in using richer objects for jobs.

The Qu:Job class currently implements 4 hooks (perform, complete, release, failure). Others will be coming soon, but I still need to figure out some implementation details.  A hook is a method that is called before, after, or around one of the events.  Calling `halt` in a before hook will prevent the original action from occurring (example: `halt` in a before_failure hook will prevent the job from being marked as failed) and will stop all other hooks.

Here are some examples of what a job using hooks will look like:

class MyJob < Qu::Job
  attr_reader :thing

  around_perform :timeout  
  before_perform :notify_before_perform
  after_perform :notify_before_perform

  before_failure :ignore_annoying_errors

  def initialize(thing_id)
    @thing = Thing.find(thing_id)
  end

  def perform
    # …
  end

private

  def notify_before_perform
    notifier.announce "Performing job #{id}"
  end

  def notify_after_perform
    notifier.announce "Done performing job #{id}"
  end

  def ignore_annoying_errors(e)
    halt if e < ErrorIDoNotCareAbout
  end

  def timeout
    Timeout.timeout(60) do
      yield
    end
  end
end

So, what do you think so far? Anything you would do differently?

Thanks,
Brandon