Add basic implementation of local device list changes

synapse/storage/_base.py

@@ -387,6 +387,10 @@ class SQLBaseStore(object):
         Args:
             table : string giving the table name
             values : dict of new column names and values for them
+
+        Returns:
+            bool: Whether the row was inserted or not. Only useful when
+            `or_ignore` is True
         """
         try:
             yield self.runInteraction(
@@ -398,6 +402,8 @@ class SQLBaseStore(object):
             # a cursor after we receive an error from the db.
             if not or_ignore:
                 raise
+            defer.returnValue(False)
+        defer.returnValue(True)
 
     @staticmethod
     def _simple_insert_txn(txn, table, values):