Define & document _getDataTID on database manager.

git-svn-id: https://svn.erp5.org/repos/neo/trunk@2300 71dcc9de-d417-0410-9af5-da40c76e7ee4

neo/storage/database/manager.py

@@ -296,6 +296,25 @@ class DatabaseManager(object):
         pack state (True for packed)."""
         raise NotImplementedError
 
+    def _getDataTID(self, oid, tid=None, before_tid=None):
+        """
+        Return a 2-tuple:
+        tid (int)
+            tid corresponding to received parameters
+        serial
+            tid at which actual object data is located
+
+        If 'tid is None', requested object and transaction could
+        not be found.
+        If 'serial is None', requested object exist but has no data (its creation
+        has been undone).
+        If 'tid == serial', it means that requested transaction
+        contains object data.
+        Otherwise, it's an undo transaction which did not involve conflict
+        resolution.
+        """
+        raise NotImplementedError
+
     def findUndoTID(self, oid, tid, undone_tid, transaction_object):
         """
         oid

neo/storage/database/mysqldb.py

@@ -455,22 +455,6 @@ class MySQLDatabaseManager(DatabaseManager):
         return tid, data_serial
 
     def _getDataTID(self, oid, tid=None, before_tid=None):
-        """
-        Return a 2-tuple:
-        tid (int)
-            tid corresponding to received parameters
-        serial
-            tid at which actual object data is located
-
-        If 'tid is None', requested object and transaction could
-        not be found.
-        If 'serial is None', requested object exist but has no data (its creation
-        has been undone).
-        If 'tid == serial', it means that requested transaction
-        contains object data.
-        Otherwise, it's an undo transaction which did not involve conflict
-        resolution.
-        """
         result = self._getObject(oid, tid=tid, before_tid=before_tid)
         if result is None:
             result = (None, None)