Resque meta data

I wanted to know how long Resque jobs sit in the queue before getting passed to a worker. This was surprisingly easy to add due the flexibility in Resque.push and Resque::Job. I almost filed a pull request when I ran into one issue.

This would remove the ability of Resque::Job.destroy to destroy a job without scanning through every entry. It didn't look like this functionality is used anywhere though, so I didn't want to spend a bunch of time preparing a pull request.

I put our patch on Gist, and it's currently running production.

I tried to make this ugly patch a well-behaving Resque plugin, but ran into another slight snag. Resque hooks yield the list of job arguments. It makes more sense to me to yield the Resque::Job instances themselves if possible. This way I could access the #queued_at property, or any other meta data I feel like adding. Internally, we're talking about adding a few other bits of metadata, like the user_id or IP of the request that queued the job.

Start with Resque.push and Resque::Job in lib/resque/job.rb, including the destroy implementation and hook behavior referenced in the issue. Review the linked Gist and existing discussion before deciding how queued_at and other metadata should be exposed while preserving job destruction behavior. Done means the metadata and hook API requirements are agreed and covered by appropriate tests.