# HG changeset patch
# User Mads Kiilerich <madski@unity3d.com>
# Date 1420502076 -3600
# Node ID b91c5a6327bd0be6d39c9de5898b416e08fa7358
# Parent  89bf1b081cc6449a7b9c0eb5c7b7f1864a0f22b0
comments: optimize notification creation

.append to the sqlalchemy collection is apparently expensive. Setting the
reference the other way around is much faster. Adding a notification for a
single user goes from 0.25 s to 0.001 s.

On a slow repo and a pullrequest with 14 reviewers, adding a comment goes from
8.5 s to 0.8 s.

diff -r 89bf1b081cc6 -r b91c5a6327bd kallithea/model/db.py
--- a/kallithea/model/db.py	Tue Jan 06 00:54:36 2015 +0100
+++ b/kallithea/model/db.py	Tue Jan 06 00:54:36 2015 +0100
@@ -2363,8 +2363,10 @@
         for u in recipients:
             assoc = UserNotification()
             assoc.notification = notification
-            u.notifications.append(assoc)
+            assoc.user_id = u.user_id
+            Session().add(assoc)
         Session().add(notification)
+        Session().flush() # assign notificaiton.notification_id
         return notification
 
     @property