Files
pretix_cgo/src/pretix/base/services/async.py
2016-11-20 15:19:31 +01:00

56 lines
1.6 KiB
Python

"""
This code has been taken from
https://blog.hypertrack.io/2016/10/08/dealing-with-database-transactions-in-django-celery/
Usage:
from pretix.base.services.async import TransactionAwareTask
@task(base=TransactionAwareTask)
def task_…():
"""
import cProfile
import os
import random
import time
from django.conf import settings
from django.db import transaction
from pretix.celery import app
class ProfiledTask(app.Task):
abstract = True
def __call__(self, *args, **kwargs):
if settings.PROFILING_RATE > 0 and random.random() < settings.PROFILING_RATE / 100:
profiler = cProfile.Profile()
profiler.enable()
starttime = time.time()
ret = super().__call__(*args, **kwargs)
profiler.disable()
tottime = time.time() - starttime
profiler.dump_stats(os.path.join(settings.PROFILE_DIR, '{time:.0f}_{tottime:.3f}_celery_{t}.pstat'.format(
t=self.name, tottime=tottime, time=time.time()
)))
return ret
else:
return super().__call__(*args, **kwargs)
class TransactionAwareTask(ProfiledTask):
"""
Task class which is aware of django db transactions and only executes tasks
after transaction has been committed
"""
abstract = True
def apply_async(self, *args, **kwargs):
"""
Unlike the default task in celery, this task does not return an async
result
"""
transaction.on_commit(
lambda: super(TransactionAwareTask, self).apply_async(*args, **kwargs)
)