def key_values(cls, *key_fields, **kwargs):
"""
Get the set of unique values in the configuration table for the given
key[s]. Calling cls.current(*value) for each value in the resulting
list should always produce an entry, though any such entry may have
enabled=False.
Arguments:
key_fields: The positional arguments are the KEY_FIELDS to return. For example if
you had a course embargo configuration where each entry was keyed on (country,
course), then you might want to know "What countries have embargoes configured?"
with cls.key_values('country'), or "Which courses have country restrictions?"
with cls.key_values('course'). You can also leave this unspecified for the
default, which returns the distinct combinations of all keys.
flat: If you pass flat=True as a kwarg, it has the same effect as in Django's
'values_list' method: Instead of returning a list of lists, you'll get one list
of values. This makes sense to use whenever there is only one key being queried.
Return value:
List of lists of each combination of keys found in the database.
e.g. [("Italy", "course-v1:SomeX+some+2015"), ...] for the course embargo example
"""
flat = kwargs.pop('flat', False)
assert not kwargs, "'flat' is the only kwarg accepted"
key_fields = key_fields or cls.KEY_FIELDS
cache_key = cls.key_values_cache_key_name(*key_fields)
cached_response = TieredCache.get_cached_response(cache_key)
if cached_response.is_found:
return cached_response.value
values = list(
cls.objects.values_list(*key_fields,
flat=flat).order_by().distinct())
TieredCache.set_all_tiers(cache_key, values, cls.cache_timeout)
return values
def test_get_cached_response_django_cache_hit(self, mock_cache_get):
mock_cache_get.return_value = EXPECTED_VALUE
cached_response = TieredCache.get_cached_response(TEST_KEY)
self.assertTrue(cached_response.is_found)
self.assertEqual(cached_response.value, EXPECTED_VALUE)
cached_response = self.request_cache.get_cached_response(TEST_KEY)
self.assertTrue(
cached_response.is_found,
'Django cache hit should cache value in request cache.')
def test_get_cached_response_force_cache_miss(self, mock_cache_get):
self.request_cache.set(SHOULD_FORCE_CACHE_MISS_KEY, True)
mock_cache_get.return_value = EXPECTED_VALUE
cached_response = TieredCache.get_cached_response(TEST_KEY)
self.assertFalse(cached_response.is_found)
cached_response = self.request_cache.get_cached_response(TEST_KEY)
self.assertFalse(
cached_response.is_found,
'Forced Django cache miss should not cache value in request cache.'
)
def current(cls, *args):
"""
Return the active configuration entry, either from cache,
from the database, or by creating a new empty entry (which is not
persisted).
"""
cache_key = cls.cache_key_name(*args)
cached_response = TieredCache.get_cached_response(cache_key)
if cached_response.is_found:
return cached_response.value
key_dict = dict(zip(cls.KEY_FIELDS, args))
try:
current = cls.objects.filter(
**key_dict).order_by('-change_date')[0]
except IndexError:
current = cls(**key_dict)
TieredCache.set_all_tiers(cache_key, current, cls.cache_timeout)
return current
def get_routers(self, backend_name):
"""
Bring active routers of a backend.
A queryset for the active configuration entries only. Only useful if backend_name is passed.
This function will return all active routers of a backend.
"""
if not backend_name:
return []
cache_key = get_cache_key(namespace="event_routing_backends",
resource=backend_name)
cached_response = TieredCache.get_cached_response(cache_key)
if cached_response.is_found:
return cached_response.value
current = self.current_set().filter(
backend_name=backend_name, enabled=True).order_by('-change_date')
TieredCache.set_all_tiers(cache_key, current, backend_cache_ttl())
return current
def test_get_cached_response_request_cache_hit(self):
self.request_cache.set(TEST_KEY, EXPECTED_VALUE)
cached_response = TieredCache.get_cached_response(TEST_KEY)
self.assertTrue(cached_response.is_found)
self.assertEqual(cached_response.value, EXPECTED_VALUE)
def test_get_cached_response_all_tier_miss(self):
cached_response = TieredCache.get_cached_response(TEST_KEY)
self.assertFalse(cached_response.is_found)
