Class: Cuetip::Models::QueuedJob

Inherits:
ActiveRecord::Base
  • Object
show all
Defined in:
lib/cuetip/models/queued_job.rb

Constant Summary collapse

PROCESS_IDENTIFIER = 
Socket.gethostname + ":#{Process.pid}"

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.find_and_lock(queued_job_id = nil) ⇒ Object

Simultaneously find an outstanding job and lock it



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# File 'lib/cuetip/models/queued_job.rb', line 33

def self.find_and_lock(queued_job_id = nil)
  lock_id = generate_lock_id
  scope = if queued_job_id
            where(id: queued_job_id)
          else
            self
          end
  count = scope.pending.limit(1).update_all(locked_by: lock_id, locked_at: Time.now)
  QueuedJob.find_by_locked_by(lock_id) if count > 0
end

.generate_lock_id ⇒ Object

Generate a random lock ID to use in the locking process



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# File 'lib/cuetip/models/queued_job.rb', line 28

def self.generate_lock_id
  PROCESS_IDENTIFIER + ':' + rand(1_000_000_000).to_s.rjust(9, '0')
end

Instance Method Details

#requeue(attributes = {}) ⇒ Object

Unlock the job and allow it to be re-run elsewhere.



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# File 'lib/cuetip/models/queued_job.rb', line 19

def requeue(attributes = {})
  self.attributes = attributes
  self.locked_by = nil
  self.locked_at = nil
  save!
  self
end