Fixed #21125 -- Removed support for cache URI syntax

django/core/cache/__init__.py

@@ -8,9 +8,9 @@ the abstract BaseCache class in django.core.cache.backends.base.
 
 Client code should not access a cache backend directly; instead it should
 either use the "cache" variable made available here, or it should use the
-get_cache() function made available here. get_cache() takes a backend URI
-(e.g. "memcached://127.0.0.1:11211/") and returns an instance of a backend
-cache class.
+get_cache() function made available here. get_cache() takes a CACHES alias or a
+backend path and config parameters, and returns an instance of a backend cache
+class.
 
 See docs/topics/cache.txt for information on the public API.
 """
@@ -29,78 +29,17 @@ __all__ = [
     'get_cache', 'cache', 'DEFAULT_CACHE_ALIAS'
 ]
 
-# Name for use in settings file --> name of module in "backends" directory.
-# Any backend scheme that is not in this dictionary is treated as a Python
-# import path to a custom backend.
-BACKENDS = {
-    'memcached': 'memcached',
-    'locmem': 'locmem',
-    'file': 'filebased',
-    'db': 'db',
-    'dummy': 'dummy',
-}
-
 DEFAULT_CACHE_ALIAS = 'default'
 
-def parse_backend_uri(backend_uri):
-    """
-    Converts the "backend_uri" into a cache scheme ('db', 'memcached', etc), a
-    host and any extra params that are required for the backend. Returns a
-    (scheme, host, params) tuple.
-    """
-    if backend_uri.find(':') == -1:
-        raise InvalidCacheBackendError("Backend URI must start with scheme://")
-    scheme, rest = backend_uri.split(':', 1)
-    if not rest.startswith('//'):
-        raise InvalidCacheBackendError("Backend URI must start with scheme://")
-
-    host = rest[2:]
-    qpos = rest.find('?')
-    if qpos != -1:
-        params = dict(parse_qsl(rest[qpos+1:]))
-        host = rest[2:qpos]
-    else:
-        params = {}
-    if host.endswith('/'):
-        host = host[:-1]
-
-    return scheme, host, params
-
 if DEFAULT_CACHE_ALIAS not in settings.CACHES:
     raise ImproperlyConfigured("You must define a '%s' cache" % DEFAULT_CACHE_ALIAS)
 
-def parse_backend_conf(backend, **kwargs):
-    """
-    Helper function to parse the backend configuration
-    that doesn't use the URI notation.
-    """
-    # Try to get the CACHES entry for the given backend name first
-    conf = settings.CACHES.get(backend, None)
-    if conf is not None:
-        args = conf.copy()
-        args.update(kwargs)
-        backend = args.pop('BACKEND')
-        location = args.pop('LOCATION', '')
-        return backend, location, args
-    else:
-        try:
-            # Trying to import the given backend, in case it's a dotted path
-            import_by_path(backend)
-        except ImproperlyConfigured as e:
-            raise InvalidCacheBackendError("Could not find backend '%s': %s" % (
-                backend, e))
-        location = kwargs.pop('LOCATION', '')
-        return backend, location, kwargs
 
 def get_cache(backend, **kwargs):
     """
     Function to load a cache backend dynamically. This is flexible by design
     to allow different use cases:
 
-    To load a backend with the old URI-based notation::
-
-        cache = get_cache('locmem://')
-
     To load a backend that is pre-defined in the settings::
 
         cache = get_cache('default')
@@ -114,17 +53,24 @@ def get_cache(backend, **kwargs):
 
     """
     try:
-        if '://' in backend:
-            # for backwards compatibility
-            backend, location, params = parse_backend_uri(backend)
-            if backend in BACKENDS:
-                backend = 'django.core.cache.backends.%s' % BACKENDS[backend]
-            params.update(kwargs)
-            mod = importlib.import_module(backend)
-            backend_cls = mod.CacheClass
+        # Try to get the CACHES entry for the given backend name first
+        try:
+            conf = settings.CACHES[backend]
+        except KeyError:
+            try:
+                # Trying to import the given backend, in case it's a dotted path
+                import_by_path(backend)
+            except ImproperlyConfigured as e:
+                raise InvalidCacheBackendError("Could not find backend '%s': %s" % (
+                    backend, e))
+            location = kwargs.pop('LOCATION', '')
+            params = kwargs
         else:
-            backend, location, params = parse_backend_conf(backend, **kwargs)
-            backend_cls = import_by_path(backend)
+            params = conf.copy()
+            params.update(kwargs)
+            backend = params.pop('BACKEND')
+            location = params.pop('LOCATION', '')
+        backend_cls = import_by_path(backend)
     except (AttributeError, ImportError, ImproperlyConfigured) as e:
         raise InvalidCacheBackendError(
             "Could not find backend '%s': %s" % (backend, e))

docs/releases/1.7.txt

@@ -414,6 +414,10 @@ Miscellaneous
   Rationale behind this is removal of dependency of non-contrib code on
   contrib applications.
 
+* The old cache URI syntax (e.g. ``"locmem://"``) is no longer supported. It
+  still worked, even though it was not documented or officially supported. If
+  you're still using it, please update to the current :setting:`CACHES` syntax.
+
 Features deprecated in 1.7
 ==========================
 

tests/cache/tests.py

@@ -857,10 +857,6 @@ class DBCacheTests(BaseCacheTests, TransactionTestCase):
         self.cache = get_cache(self.backend_name, LOCATION=self._table_name, OPTIONS={'MAX_ENTRIES': 30, 'CULL_FREQUENCY': 0})
         self.perform_cull_test(50, 18)
 
-    def test_old_initialization(self):
-        self.cache = get_cache('db://%s?max_entries=30&cull_frequency=0' % self._table_name)
-        self.perform_cull_test(50, 18)
-
     def test_second_call_doesnt_crash(self):
         with six.assertRaisesRegex(self, management.CommandError,
                 "Cache table 'test cache table' could not be created"):
@@ -956,10 +952,6 @@ class LocMemCacheTests(unittest.TestCase, BaseCacheTests):
         self.cache = get_cache(self.backend_name, OPTIONS={'MAX_ENTRIES': 30, 'CULL_FREQUENCY': 0})
         self.perform_cull_test(50, 19)
 
-    def test_old_initialization(self):
-        self.cache = get_cache('locmem://?max_entries=30&cull_frequency=0')
-        self.perform_cull_test(50, 19)
-
     def test_multiple_caches(self):
         "Check that multiple locmem caches are isolated"
         mirror_cache = get_cache(self.backend_name)
@@ -1075,10 +1067,6 @@ class FileBasedCacheTests(unittest.TestCase, BaseCacheTests):
     def test_cull(self):
         self.perform_cull_test(50, 29)
 
-    def test_old_initialization(self):
-        self.cache = get_cache('file://%s?max_entries=30' % self.dirname)
-        self.perform_cull_test(50, 29)
-
 
 class CustomCacheKeyValidationTests(unittest.TestCase):
     """
@@ -1088,7 +1076,7 @@ class CustomCacheKeyValidationTests(unittest.TestCase):
 
     """
     def test_custom_key_validation(self):
-        cache = get_cache('cache.liberal_backend://')
+        cache = get_cache('cache.liberal_backend.CacheClass')
 
         # this key is both longer than 250 characters, and has spaces
         key = 'some key with spaces' * 15
@@ -1100,10 +1088,6 @@ class CustomCacheKeyValidationTests(unittest.TestCase):
 class GetCacheTests(unittest.TestCase):
 
     def test_simple(self):
-        cache = get_cache('locmem://')
-        from django.core.cache.backends.locmem import LocMemCache
-        self.assertIsInstance(cache, LocMemCache)
-
         from django.core.cache import cache
         self.assertIsInstance(cache, get_cache('default').__class__)