Fix slow performance with S3 jazzband#662 jazzband#301 jazzband#508

sorl/thumbnail/images.py

@@ -18,6 +18,14 @@
 
 url_pat = re.compile(r'^(https?|ftp):\/\/')
 
+STORAGES_CACHE = {}
+
+
+def get_or_create_storage(storage):
+    if storage not in STORAGES_CACHE:
+        STORAGES_CACHE[storage] = get_module_class(storage)()
+    return STORAGES_CACHE[storage]
+
 
 def serialize_image_file(image_file):
     if image_file.size is None:
@@ -33,12 +41,7 @@ def serialize_image_file(image_file):
 
 def deserialize_image_file(s):
     data = deserialize(s)
-
-    class LazyStorage(LazyObject):
-        def _setup(self):
-            self._wrapped = get_module_class(data['storage'])()
-
-    image_file = ImageFile(data['name'], LazyStorage())
+    image_file = ImageFile(data['name'], get_or_create_storage(data['storage']))
     image_file.set_size(data['size'])
     return image_file