Convert gen.db to use abstract base classes

gramps/gen/db/undoredo.py

@@ -3,11 +3,12 @@
 # Standard python modules
 #
 #-------------------------------------------------------------------------
+from abc import ABCMeta, abstractmethod
 import time
 import pickle
 from collections import deque
 
-class DbUndo:
+class DbUndo(metaclass=ABCMeta):
     """
     Base class for the Gramps undo/redo manager.  Needs to be subclassed
     for use with a real backend.
@@ -65,56 +66,56 @@ class DbUndo:
             self.close()
         return exc_type is None
 
+    @abstractmethod
     def open(self, value):
         """
         Open the backing storage.  Needs to be overridden in the derived
         class.
         """
-        raise NotImplementedError
 
+    @abstractmethod
     def close(self):
         """
         Close the backing storage.  Needs to be overridden in the derived
         class.
         """
-        raise NotImplementedError
 
+    @abstractmethod
     def append(self, value):
         """
         Add a new entry on the end.  Needs to be overridden in the derived
         class.
         """
-        raise NotImplementedError
 
+    @abstractmethod
     def __getitem__(self, index):
         """
         Returns an entry by index number.  Needs to be overridden in the
         derived class.
         """
-        raise NotImplementedError
 
+    @abstractmethod
     def __setitem__(self, index, value):
         """
         Set an entry to a value.  Needs to be overridden in the derived class.
         """
-        raise NotImplementedError
 
+    @abstractmethod
     def __len__(self):
         """
         Returns the number of entries.  Needs to be overridden in the derived
         class.
         """
-        raise NotImplementedError
 
-    def __redo(self, update_history):
+    @abstractmethod
+    def _redo(self, update_history):
         """
         """
-        raise NotImplementedError
 
-    def __undo(self, update_history):
+    @abstractmethod
+    def _undo(self, update_history):
         """
         """
-        raise NotImplementedError
 
     def commit(self, txn, msg):
         """

gramps/plugins/database/dbapi.py

@@ -2014,3 +2014,60 @@ class DBAPI(DbGeneric):
         summary = super().get_summary()
         summary.update(self.dbapi.__class__.get_summary())
         return summary
+
+    # TODO: The following abstract methods need implementing.
+    # See bug #9547.
+
+    def add_family_event(event, transaction):
+        pass
+
+    def add_person_event(event, transaction):
+        pass
+
+    def all_handles(table):
+        pass
+
+    def commit_base(obj, data_map, key, transaction, change_time):
+        pass
+
+    def commit_family_event(event, transaction, change_time):
+        pass
+
+    def commit_personal_event(event, transaction, change_time):
+        pass
+
+    def delete_primary_from_reference_map(handle, transaction):
+        pass
+
+    def get_from_handle(handle, class_type, data_map):
+        pass
+
+    def get_reference_map_cursor():
+        pass
+
+    def get_reference_map_primary_cursor():
+        pass
+
+    def get_reference_map_referenced_cursor():
+        pass
+
+    def gramps_upgrade():
+        pass
+
+    def need_schema_upgrade():
+        pass
+
+    def set_auto_remove():
+        pass
+
+    def set_redo_callback(callback):
+        pass
+
+    def set_undo_callback(callback):
+        pass
+
+    def sort_surname_list():
+        pass
+
+    def update_reference_map(obj, transaction):
+        pass