Add a way to choose the protocol for pickle.

README.rst

@@ -51,7 +51,8 @@ On Django >= 1.3::
             'OPTIONS': {
                 'DB': 1,
                 'PASSWORD': 'yadayada',
-                'PARSER_CLASS': 'redis.connection.HiredisParser'
+                'PARSER_CLASS': 'redis.connection.HiredisParser',
+                'PICKLE_VERSION': 2 # optional, default to 0
             },
         },
     }
@@ -66,7 +67,8 @@ On Django >= 1.3::
             'OPTIONS': {
                 'DB': 1,
                 'PASSWORD': 'yadayada',
-                'PARSER_CLASS': 'redis.connection.HiredisParser'
+                'PARSER_CLASS': 'redis.connection.HiredisParser',
+                'PICKLE_VERSION': 2 # optional, default to 0
             },
         },
     }

redis_cache/cache.py

@@ -76,6 +76,7 @@ def _init(self, server, params):
         super(CacheClass, self).__init__(params)
         self._server = server
         self._params = params
+        self._pickle_version = None
 
         unix_socket_path = None
         if ':' in self.server:
@@ -142,6 +143,20 @@ def parser_class(self):
             raise ImproperlyConfigured("Could not find parser class '%s'" % parser_class)
         return parser_class
 
+    @property
+    def pickle_version(self):
+        """
+        Get the pickle version from the settings and save it for future use
+        """
+        if self._pickle_version is None:
+            _pickle_version = self.options.get('PICKLE_VERSION', 0)
+            try:
+                _pickle_version = int(_pickle_version)
+            except (ValueError, TypeError):
+                raise ImproperlyConfigured("pickle version value must be an integer")
+            self._pickle_version = _pickle_version
+        return self._pickle_version
+
     def __getstate__(self):
         return {'params': self._params, 'server': self._server}
 
@@ -207,7 +222,7 @@ def set(self, key, value, timeout=None, version=None, client=None):
             if int(value) != value:
                 raise TypeError
         except (ValueError, TypeError):
-            result = self._set(key, pickle.dumps(value), int(timeout), client)
+            result = self._set(key, self.pickle(value), int(timeout), client)
         else:
             result = self._set(key, int(value), int(timeout), client)
         # result is a boolean
@@ -241,6 +256,12 @@ def unpickle(self, value):
         value = smart_str(value)
         return pickle.loads(value)
 
+    def pickle(self, value):
+        """
+        Pickle the given value.
+        """
+        return pickle.dumps(value, self.pickle_version)
+
     def get_many(self, keys, version=None):
         """
         Retrieve many keys.