refactored endpoints.api.subscribe to use abstracted data interface

endpoints/api/subscribe_models_interface.py

@@ -0,0 +1,26 @@
+from abc import ABCMeta, abstractmethod
+from six import add_metaclass
+
+
+@add_metaclass(ABCMeta)
+class SubscribeInterface(object):
+  """
+  Interface that represents all data store interactions required by the subscribe API endpoint.
+  """
+  @abstractmethod
+  def get_private_repo_count(self, username):
+    """
+    Returns the number of private repositories for a given username or namespace.
+    """
+
+  @abstractmethod
+  def create_unique_notification(self, kind_name, target_username, metadata={}):
+    """
+    Creates a notification using the given parameters.
+    """
+
+  @abstractmethod
+  def delete_notifications_by_kind(self, target_username, kind_name):
+    """
+    Remove notifications for a target based on given kind.
+    """