Files
django-q2/django_q/brokers/orm.py
T
Ilan Steemers 1d12107524 Changed locking mechanism
* all new tasks start as timeouts. This makes the queries a lot simpler.

* In BULK mode, the bulk update for the lock was causing actual database locks.  The lock updates are now iterated.
2015-09-17 18:49:03 +02:00

63 lines
1.7 KiB
Python

from datetime import timedelta
from time import sleep
from django.utils import timezone
from django_q.brokers import Broker
from django_q.models import OrmQ
from django_q.conf import Conf
def _timeout():
return timezone.now() - timedelta(seconds=Conf.RETRY)
class ORM(Broker):
@staticmethod
def get_connection(list_key=Conf.PREFIX):
return OrmQ.objects.using(Conf.ORM)
def queue_size(self):
return self.connection.filter(key=self.list_key, lock__lte=_timeout()).count()
def lock_size(self):
return self.connection.filter(key=self.list_key, lock__gte=_timeout()).count()
def purge_queue(self):
return self.connection.filter(key=self.list_key).delete()
def ping(self):
return True
def info(self):
return 'ORM {}'.format(Conf.ORM)
def fail(self, task_id):
self.delete(task_id)
def enqueue(self, task):
package = self.connection.create(key=self.list_key, payload=task, lock=_timeout())
return package.pk
def dequeue(self):
tasks = self.connection.filter(key=self.list_key, lock__lt=_timeout())[0:Conf.BULK]
if tasks:
task_list = []
lock = timezone.now()
for task in tasks:
task.lock = lock
task.save(update_fields=['lock'])
task_list.append((task.pk, task.payload))
return task_list
# empty queue, spare the cpu
sleep(0.2)
def delete_queue(self):
return self.purge_queue()
def delete(self, task_id):
self.connection.filter(pk=task_id).delete()
def acknowledge(self, task_id):
return self.delete(task_id)