1 files changed, 23 insertions, 9 deletions
diff --git a/synapse/storage/_base.py b/synapse/storage/_base.py
index 2f940dbae6..489ce82fae 100644
--- a/synapse/storage/_base.py
+++ b/synapse/storage/_base.py
@@ -86,7 +86,21 @@ _CURRENT_STATE_CACHE_NAME = "cs_cache_fake"
 class LoggingTransaction(object):
     """An object that almost-transparently proxies for the 'txn' object
     passed to the constructor. Adds logging and metrics to the .execute()
-    method."""
+    method.
+
+    Args:
+        txn: The database transcation object to wrap.
+        name (str): The name of this transactions for logging.
+        database_engine (Sqlite3Engine|PostgresEngine)
+        after_callbacks(list|None): A list that callbacks will be appended to
+            that have been added by `call_after` which should be run on
+            successful completion of the transaction. None indicates that no
+            callbacks should be allowed to be scheduled to run.
+        exception_callbacks(list|None): A list that callbacks will be appended
+            to that have been added by `call_on_exception` which should be run
+            if transaction ends with an error. None indicates that no callbacks
+            should be allowed to be scheduled to run.
+    """
 
     __slots__ = [
         "txn",
@@ -97,7 +111,7 @@ class LoggingTransaction(object):
     ]
 
     def __init__(
-        self, txn, name, database_engine, after_callbacks, exception_callbacks
+        self, txn, name, database_engine, after_callbacks=None, exception_callbacks=None
     ):
         object.__setattr__(self, "txn", txn)
         object.__setattr__(self, "name", name)
@@ -499,7 +513,7 @@ class SQLBaseStore(object):
                 after_callback(*after_args, **after_kwargs)
             raise
 
-        defer.returnValue(result)
+        return result
 
     @defer.inlineCallbacks
     def runWithConnection(self, func, *args, **kwargs):
@@ -539,7 +553,7 @@ class SQLBaseStore(object):
         with PreserveLoggingContext():
             result = yield self._db_pool.runWithConnection(inner_func, *args, **kwargs)
 
-        defer.returnValue(result)
+        return result
 
     @staticmethod
     def cursor_to_dict(cursor):
@@ -601,8 +615,8 @@ class SQLBaseStore(object):
             # a cursor after we receive an error from the db.
             if not or_ignore:
                 raise
-            defer.returnValue(False)
-        defer.returnValue(True)
+            return False
+        return True
 
     @staticmethod
     def _simple_insert_txn(txn, table, values):
@@ -694,7 +708,7 @@ class SQLBaseStore(object):
                     insertion_values,
                     lock=lock,
                 )
-                defer.returnValue(result)
+                return result
             except self.database_engine.module.IntegrityError as e:
                 attempts += 1
                 if attempts >= 5:
@@ -1107,7 +1121,7 @@ class SQLBaseStore(object):
         results = []
 
         if not iterable:
-            defer.returnValue(results)
+            return results
 
         # iterables can not be sliced, so convert it to a list first
         it_list = list(iterable)
@@ -1128,7 +1142,7 @@ class SQLBaseStore(object):
 
             results.extend(rows)
 
-        defer.returnValue(results)
+        return results
 
     @classmethod
     def _simple_select_many_txn(cls, txn, table, column, iterable, keyvalues, retcols):