Re-implement unread counts (again) (#8059)

1 files changed, 18 insertions, 15 deletions

diff --git a/synapse/handlers/sync.py b/synapse/handlers/sync.py
index 9a86eb01c9..43fc40fc2f 100644
--- a/synapse/handlers/sync.py
+++ b/synapse/handlers/sync.py
@@ -95,7 +95,12 @@ class TimelineBatch:
     __bool__ = __nonzero__  # python3
 
 
-@attr.s(slots=True, frozen=True)
+# We can't freeze this class, because we need to update it after it's instantiated to
+# update its unread count. This is because we calculate the unread count for a room only
+# if there are updates for it, which we check after the instance has been created.
+# This should not be a big deal because we update the notification counts afterwards as
+# well anyway.
+@attr.s(slots=True)
 class JoinedSyncResult:
     room_id = attr.ib(type=str)
     timeline = attr.ib(type=TimelineBatch)
@@ -104,6 +109,7 @@ class JoinedSyncResult:
     account_data = attr.ib(type=List[JsonDict])
     unread_notifications = attr.ib(type=JsonDict)
     summary = attr.ib(type=Optional[JsonDict])
+    unread_count = attr.ib(type=int)
 
     def __nonzero__(self) -> bool:
         """Make the result appear empty if there are no updates. This is used
@@ -931,7 +937,7 @@ class SyncHandler(object):
 
     async def unread_notifs_for_room_id(
         self, room_id: str, sync_config: SyncConfig
-    ) -> Optional[Dict[str, str]]:
+    ) -> Dict[str, int]:
         with Measure(self.clock, "unread_notifs_for_room_id"):
             last_unread_event_id = await self.store.get_last_receipt_event_id_for_user(
                 user_id=sync_config.user.to_string(),
@@ -939,15 +945,10 @@ class SyncHandler(object):
                 receipt_type="m.read",
             )
 
-            if last_unread_event_id:
-                notifs = await self.store.get_unread_event_push_actions_by_room_for_user(
-                    room_id, sync_config.user.to_string(), last_unread_event_id
-                )
-                return notifs
-
-        # There is no new information in this period, so your notification
-        # count is whatever it was last time.
-        return None
+            notifs = await self.store.get_unread_event_push_actions_by_room_for_user(
+                room_id, sync_config.user.to_string(), last_unread_event_id
+            )
+            return notifs
 
     async def generate_sync_result(
         self,
@@ -1886,7 +1887,7 @@ class SyncHandler(object):
             )
 
         if room_builder.rtype == "joined":
-            unread_notifications = {}  # type: Dict[str, str]
+            unread_notifications = {}  # type: Dict[str, int]
             room_sync = JoinedSyncResult(
                 room_id=room_id,
                 timeline=batch,
@@ -1895,14 +1896,16 @@ class SyncHandler(object):
                 account_data=account_data_events,
                 unread_notifications=unread_notifications,
                 summary=summary,
+                unread_count=0,
             )
 
             if room_sync or always_include:
                 notifs = await self.unread_notifs_for_room_id(room_id, sync_config)
 
-                if notifs is not None:
-                    unread_notifications["notification_count"] = notifs["notify_count"]
-                    unread_notifications["highlight_count"] = notifs["highlight_count"]
+                unread_notifications["notification_count"] = notifs["notify_count"]
+                unread_notifications["highlight_count"] = notifs["highlight_count"]
+
+                room_sync.unread_count = notifs["unread_count"]
 
                 sync_result_builder.joined.append(room_sync)