def __call__(self, request):
# Initialize an empty list to cache objects being saved.
_thread_locals.changed_objects = []
# Assign a random unique ID to the request. This will be used to associate multiple object changes made during
# the same request.
request.id = uuid.uuid4()
# Connect our receivers to the post_save and post_delete signals.
post_save.connect(handle_changed_object, dispatch_uid='handle_changed_object')
pre_delete.connect(handle_deleted_object, dispatch_uid='handle_deleted_object')
# Provide a hook for purging the change cache
purge_changelog.connect(purge_objectchange_cache)
# Process the request
response = self.get_response(request)
# If the change cache is empty, there's nothing more we need to do.
if not _thread_locals.changed_objects:
return response
# Create records for any cached objects that were changed.
for instance, action in _thread_locals.changed_objects:
# Refresh cached custom field values
if action in [ObjectChangeActionChoices.ACTION_CREATE, ObjectChangeActionChoices.ACTION_UPDATE]:
if hasattr(instance, 'cache_custom_fields'):
instance.cache_custom_fields()
# Record an ObjectChange if applicable
if hasattr(instance, 'to_objectchange'):
objectchange = instance.to_objectchange(action)
objectchange.user = request.user
objectchange.request_id = request.id
objectchange.save()
# Enqueue webhooks
enqueue_webhooks(instance, request.user, request.id, action)
# Increment metric counters
if action == ObjectChangeActionChoices.ACTION_CREATE:
model_inserts.labels(instance._meta.model_name).inc()
elif action == ObjectChangeActionChoices.ACTION_UPDATE:
model_updates.labels(instance._meta.model_name).inc()
elif action == ObjectChangeActionChoices.ACTION_DELETE:
model_deletes.labels(instance._meta.model_name).inc()
# Housekeeping: 1% chance of clearing out expired ObjectChanges. This applies only to requests which result in
# one or more changes being logged.
if settings.CHANGELOG_RETENTION and random.randint(1, 100) == 1:
cutoff = timezone.now() - timedelta(days=settings.CHANGELOG_RETENTION)
purged_count, _ = ObjectChange.objects.filter(
time__lt=cutoff
).delete()
return response
def _record_object_deleted(request, instance, **kwargs):
# Record that the object was deleted
if hasattr(instance, 'log_change'):
instance.log_change(request.user, request.id,
OBJECTCHANGE_ACTION_DELETE)
# Enqueue webhooks
enqueue_webhooks(instance, request.user, request.id,
OBJECTCHANGE_ACTION_DELETE)
# Increment metric counters
model_deletes.labels(instance._meta.model_name).inc()
def _handle_deleted_object(request, sender, instance, **kwargs):
"""
Fires when an object is deleted.
"""
# Record an ObjectChange if applicable
if hasattr(instance, 'to_objectchange'):
objectchange = instance.to_objectchange(ObjectChangeActionChoices.ACTION_DELETE)
objectchange.user = request.user
objectchange.request_id = request.id
objectchange.save()
# Enqueue webhooks
enqueue_webhooks(instance, request.user, request.id, ObjectChangeActionChoices.ACTION_DELETE)
# Increment metric counters
model_deletes.labels(instance._meta.model_name).inc()
def _record_object_deleted(request, instance, **kwargs):
# Force resolution of request.user in case it's still a SimpleLazyObject. This seems to happen
# occasionally during tests, but haven't been able to determine why.
# Note: We exclude SAML2 login flow deletions, as the call to request.session.flush() throws this assertion
if request.path_info != '/saml2_auth/acs/':
assert request.user.is_authenticated
# Record that the object was deleted
if hasattr(instance, 'log_change'):
instance.log_change(request.user, request.id,
OBJECTCHANGE_ACTION_DELETE)
# Enqueue webhooks
enqueue_webhooks(instance, request.user, request.id,
OBJECTCHANGE_ACTION_DELETE)
# Increment metric counters
model_deletes.labels(instance._meta.model_name).inc()
def _handle_deleted_object(request, sender, instance, **kwargs):
"""
Fires when an object is deleted.
"""
# Ignore object without the right method
if not hasattr(instance, "to_objectchange"):
return
# Record an object change
change = instance.to_objectchange(ObjectChangeAction.DELETE)
change.user = request.user
change.request_id = request.id
change.save()
# Enqueue webhooks
enqueue_webhooks(instance, request.user, request.id, ObjectChangeAction.DELETE)
# Increment metric counters
model_deletes.labels(instance._meta.model_name).inc()