Merge pull request #2054 from matrix-org/erikj/user_iter_cursor

Reduce some CPU work on DB threads

1 files changed, 5 insertions, 5 deletions

diff --git a/synapse/storage/deviceinbox.py b/synapse/storage/deviceinbox.py

index 7925cb5f1b..2714519d21 100644
--- a/synapse/storage/deviceinbox.py
+++ b/synapse/storage/deviceinbox.py
@@ -178,7 +178,7 @@ class DeviceInboxStore(BackgroundUpdateStore):
                 )
                 txn.execute(sql, (user_id,))
                 message_json = ujson.dumps(messages_by_device["*"])
-                for row in txn.fetchall():
+                for row in txn:
                     # Add the message for all devices for this user on this
                     # server.
                     device = row[0]
@@ -195,7 +195,7 @@ class DeviceInboxStore(BackgroundUpdateStore):
                 # TODO: Maybe this needs to be done in batches if there are
                 # too many local devices for a given user.
                 txn.execute(sql, [user_id] + devices)
-                for row in txn.fetchall():
+                for row in txn:
                     # Only insert into the local inbox if the device exists on
                     # this server
                     device = row[0]
@@ -251,7 +251,7 @@ class DeviceInboxStore(BackgroundUpdateStore):
                 user_id, device_id, last_stream_id, current_stream_id, limit
             ))
             messages = []
-            for row in txn.fetchall():
+            for row in txn:
                 stream_pos = row[0]
                 messages.append(ujson.loads(row[1]))
             if len(messages) < limit:
@@ -340,7 +340,7 @@ class DeviceInboxStore(BackgroundUpdateStore):
                 " ORDER BY stream_id ASC"
             )
             txn.execute(sql, (last_pos, upper_pos))
-            rows.extend(txn.fetchall())
+            rows.extend(txn)
 
             return rows
 
@@ -384,7 +384,7 @@ class DeviceInboxStore(BackgroundUpdateStore):
                 destination, last_stream_id, current_stream_id, limit
             ))
             messages = []
-            for row in txn.fetchall():
+            for row in txn:
                 stream_pos = row[0]
                 messages.append(ujson.loads(row[1]))
             if len(messages) < limit: