On Sun, Jul 15, 2012 at 11:07 AM, Jeremy Dunck <jdu...@gmail.com> wrote: > > That is indeed what I meant, but I think Anssi's probably right that > this belongs in contribute_to_class instead of a new adhoc thing in > ModelBase.__new__. > > I'll take a swing at making this change. > > Opened related ticket: https://code.djangoproject.com/ticket/18627
OK, I have a very rough cut w/ all tests passing here: https://github.com/jdunck/django/tree/18627_pre_init I poked in a flag, sys.JDUNCK_NEW, which can be turned on/off for old and new implementation - this is poked in at django.__init__ To test performance, using tests/test_sqlite modified with: INSTALLED_APPS = [ 'regressiontests.model_fields' ] and DATABASES['default']['name'] = ':memory:' Testing the pre_init hook: timeit.Timer(""" for i in names: models.Person(name=i) """, """ from django.core.management import call_command from regressiontests.model_fields import models call_command('syncdb') names = [str(i) for i in range(1000)] """).timeit(1000) Under the existing signal usage: 24.609718084335327 Under the new approach avoiding signal usage: 18.074234008789062 I'd expect post_init to be a smaller gain since the destination function has more overhead, but still a gain. Note that the pre_init and post_init signals are still fired -- it's just that django as-shipped won't use any listeners on them, so the Model.__init__ performance improves. In some cases, object construction currently is larger than query time - a simple 'select x from y limit 1000' would have similar overhead to this. Also, note that this gain would be seen on all models in any project using GFK or ImageField but no other pre_init or post_init hooks - not just those models which have the fields. With this switch, only the models with the hooking fields have the related overhead. Feedback welcome. -- You received this message because you are subscribed to the Google Groups "Django developers" group. To post to this group, send email to django-developers@googlegroups.com. To unsubscribe from this group, send email to django-developers+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/django-developers?hl=en.
