Define an abstract class for database storage classes.

Define DbStorageAbstract, an abstract class from which classes PgStorage, SQLiteStorage etc. will be inheriting. For now, the methods are not implemented in the abstract class.

pywps/inout/storage.py

@@ -35,6 +35,24 @@ def store(self, output):
         """
         pass
 
+class DbStorageAbstract(object):
+    """Database storage abstract class
+    """
+
+    __metaclass__ = ABCMeta
+
+    @abstractmethod
+    def store(self, output):
+
+        pass
+
+
+    @abstractmethod
+    def _store_output(self, file_name, identifier):
+
+        pass
+
+
 
 class DummyStorage(StorageAbstract):
     """Dummy empty storage implementation, does nothing