From 958cdf65ae90d26236d1815bbba804729595ec7a Mon Sep 17 00:00:00 2001
From: Mariusz Felisiak <felisiak.mariusz@gmail.com>
Date: Fri, 14 May 2021 11:53:17 +0200
Subject: [PATCH] Fixed #32747 -- Prevented initialization of unused caches.
Thanks Alexander Ebral for the report.
Regression in 98e05ccde440cc9b768952cc10bc8285f4924e1f.
---
django/core/cache/__init__.py | 9 ++++++++-
docs/releases/3.2.4.txt | 3 +++
tests/cache/tests.py | 30 ++++++++++++++++++++++++++++++
3 files changed, 41 insertions(+), 1 deletion(-)
diff --git a/django/core/cache/__init__.py b/django/core/cache/__init__.py
index 05ef3897d0..a311b50af6 100644
--- a/django/core/cache/__init__.py
+++ b/django/core/cache/__init__.py
@@ -43,6 +43,13 @@ class CacheHandler(BaseConnectionHandler):
) from e
return backend_cls(location, params)
+ def all(self, initialized_only=False):
+ return [
+ self[alias] for alias in self
+ # If initialized_only is True, return only initialized caches.
+ if not initialized_only or hasattr(self._connections, alias)
+ ]
+
caches = CacheHandler()
@@ -52,7 +59,7 @@ cache = ConnectionProxy(caches, DEFAULT_CACHE_ALIAS)
def close_caches(**kwargs):
# Some caches need to do a cleanup at the end of a request cycle. If not
# implemented in a particular backend cache.close() is a no-op.
- for cache in caches.all():
+ for cache in caches.all(initialized_only=True):
cache.close()
diff --git a/docs/releases/3.2.4.txt b/docs/releases/3.2.4.txt
index 068798e6ed..dac726e961 100644
--- a/docs/releases/3.2.4.txt
+++ b/docs/releases/3.2.4.txt
@@ -15,3 +15,6 @@ Bugfixes
* Fixed a bug in Django 3.2 where a system check would crash on an abstract
model (:ticket:`32733`).
+
+* Prevented unnecessary initialization of unused caches following a regression
+ in Django 3.2 (:ticket:`32747`).
diff --git a/tests/cache/tests.py b/tests/cache/tests.py
index c189e26e70..65a8f12fc7 100644
--- a/tests/cache/tests.py
+++ b/tests/cache/tests.py
@@ -1723,6 +1723,19 @@ class CacheClosingTests(SimpleTestCase):
signals.request_finished.send(self.__class__)
self.assertTrue(cache.closed)
+ def test_close_only_initialized(self):
+ with self.settings(CACHES={
+ 'cache_1': {
+ 'BACKEND': 'cache.closeable_cache.CacheClass',
+ },
+ 'cache_2': {
+ 'BACKEND': 'cache.closeable_cache.CacheClass',
+ },
+ }):
+ self.assertEqual(caches.all(initialized_only=True), [])
+ signals.request_finished.send(self.__class__)
+ self.assertEqual(caches.all(initialized_only=True), [])
+
DEFAULT_MEMORY_CACHES_SETTINGS = {
'default': {
@@ -2625,3 +2638,20 @@ class CacheHandlerTest(SimpleTestCase):
)
with self.assertRaisesMessage(InvalidCacheBackendError, msg):
test_caches['invalid_backend']
+
+ def test_all(self):
+ test_caches = CacheHandler({
+ 'cache_1': {
+ 'BACKEND': 'django.core.cache.backends.dummy.DummyCache',
+ },
+ 'cache_2': {
+ 'BACKEND': 'django.core.cache.backends.dummy.DummyCache',
+ },
+ })
+ self.assertEqual(test_caches.all(initialized_only=True), [])
+ cache_1 = test_caches['cache_1']
+ self.assertEqual(test_caches.all(initialized_only=True), [cache_1])
+ self.assertEqual(len(test_caches.all()), 2)
+ # .all() initializes all caches.
+ self.assertEqual(len(test_caches.all(initialized_only=True)), 2)
+ self.assertEqual(test_caches.all(), test_caches.all(initialized_only=True))