Refs #29887 -- Simplified memcached client instantiation.

django/core/cache/backends/memcached.py

@@ -23,17 +23,15 @@ class BaseMemcachedCache(BaseCache):
         self.LibraryValueNotFoundException = value_not_found_exception
 
         self._lib = library
+        self._class = library.Client
         self._options = params.get('OPTIONS') or {}
 
-    @property
+    @cached_property
     def _cache(self):
         """
         Implement transparent thread-safe access to a memcached client.
         """
-        if getattr(self, '_client', None) is None:
-            self._client = self._lib.Client(self._servers, **self._options)
-
-        return self._client
+        return self._class(self._servers, **self._options)
 
     def get_backend_timeout(self, timeout=DEFAULT_TIMEOUT):
         """
@@ -166,14 +164,7 @@ class MemcachedCache(BaseMemcachedCache):
         # incr/decr(), python-memcached < 1.45 raises ValueError.
         import memcache
         super().__init__(server, params, library=memcache, value_not_found_exception=ValueError)
-
-    @property
-    def _cache(self):
-        if getattr(self, '_client', None) is None:
-            client_kwargs = {'pickleProtocol': pickle.HIGHEST_PROTOCOL}
-            client_kwargs.update(self._options)
-            self._client = self._lib.Client(self._servers, **client_kwargs)
-        return self._client
+        self._options = {'pickleProtocol': pickle.HIGHEST_PROTOCOL, **self._options}
 
     def get(self, key, default=None, version=None):
         key = self.make_key(key, version=version)
@@ -201,10 +192,6 @@ class PyLibMCCache(BaseMemcachedCache):
         import pylibmc
         super().__init__(server, params, library=pylibmc, value_not_found_exception=pylibmc.NotFound)
 
-    @cached_property
-    def _cache(self):
-        return self._lib.Client(self._servers, **self._options)
-
     def touch(self, key, timeout=DEFAULT_TIMEOUT, version=None):
         key = self.make_key(key, version=version)
         self.validate_key(key)

tests/cache/tests.py

@@ -1374,7 +1374,7 @@ class BaseMemcachedTests(BaseCacheTests):
         # connection is closed when the request is complete.
         signals.request_finished.disconnect(close_old_connections)
         try:
-            with mock.patch.object(cache._lib.Client, 'disconnect_all', autospec=True) as mock_disconnect:
+            with mock.patch.object(cache._class, 'disconnect_all', autospec=True) as mock_disconnect:
                 signals.request_finished.send(self.__class__)
                 self.assertIs(mock_disconnect.called, self.should_disconnect_on_close)
         finally:
@@ -1383,7 +1383,7 @@ class BaseMemcachedTests(BaseCacheTests):
     def test_set_many_returns_failing_keys(self):
         def fail_set_multi(mapping, *args, **kwargs):
             return mapping.keys()
-        with mock.patch('%s.Client.set_multi' % self.client_library_name, side_effect=fail_set_multi):
+        with mock.patch.object(cache._class, 'set_multi', side_effect=fail_set_multi):
             failing_keys = cache.set_many({'key': 'value'})
             self.assertEqual(failing_keys, ['key'])
 
@@ -1395,7 +1395,6 @@ class BaseMemcachedTests(BaseCacheTests):
 ))
 class MemcachedCacheTests(BaseMemcachedTests, TestCase):
     base_params = MemcachedCache_params
-    client_library_name = 'memcache'
 
     def test_memcached_uses_highest_pickle_version(self):
         # Regression test for #19810
@@ -1427,7 +1426,6 @@ class MemcachedCacheTests(BaseMemcachedTests, TestCase):
 ))
 class PyLibMCCacheTests(BaseMemcachedTests, TestCase):
     base_params = PyLibMCCache_params
-    client_library_name = 'pylibmc'
     # libmemcached manages its own connections.
     should_disconnect_on_close = False