Unused instance variable

[mrduncan]

The @watched_queues instance variable in resque.rb is read but never written to.

The following commit removes it entirely:
mrduncan/resque@298125b9b1aa29d6214e64d44e7803cbacc17193

[defunkt]

This variable is used. I've added a comment to explain: 0f296e3

Cheers!

[mrduncan]

Unless I'm missing something, it looks like @watched_queues is only being read. I can't find anywhere that it's actually being set.

def watch_queue(queue)
  @watched_queues ||= {}
  return if @watched_queues[queue]  # <-- @watched_queues is always empty here
  redis.sadd(:queues, queue.to_s)
end

It seems like the following line should be added to actually cache the queue:

def watch_queue(queue)
  @watched_queues ||= {}
  return if @watched_queues[queue]
  redis.sadd(:queues, queue.to_s)
  @watched_queues[queue.to_s] = true  # <-- Cache it
end

Also, if the queue parameter is ever anything other than a string (I haven't checked to see if that actually ever happens), the following change should probably be made to avoid cache misses:

def watch_queue(queue)
  @watched_queues ||= {}
  return if @watched_queues[queue.to_s]  # <-- Get string for consistency
  redis.sadd(:queues, queue.to_s)
  @watched_queues[queue.to_s] = true
end

[defunkt]

You're right, looks like this needs a bugfix and a testcase.

[mrduncan]

I made an attempt at a fix (mrduncan/resque@6e4233ea6d0b8cba6068f9bb05253470fd0f6253).

The only issue that I see with it is if a queue is removed it could still be in the cache of another process - seems like the Redis set which holds queue names might not get an entry for that queue if a new job is pushed.

[defunkt]

I think you're right about the other processes caching queues. Since this has never actually worked, it's probably a case of premature optimization. I removed it in 02a6ac1

Thanks!