still very WIP, but now sends unread_notifications_count in the room object on sync (only actually corrrect in a full sync: hardcoded to 0 in incremental syncs).

synapse/handlers/sync.py

@@ -52,6 +52,7 @@ class JoinedSyncResult(collections.namedtuple("JoinedSyncResult", [
     "state",             # dict[(str, str), FrozenEvent]
     "ephemeral",
     "account_data",
+    "unread_notification_count",
 ])):
     __slots__ = []
 
@@ -64,6 +65,7 @@ class JoinedSyncResult(collections.namedtuple("JoinedSyncResult", [
             or self.state
             or self.ephemeral
             or self.account_data
+            or self.unread_notification_count > 0
         )
 
 
@@ -161,6 +163,18 @@ class SyncHandler(BaseHandler):
         else:
             return self.incremental_sync_with_gap(sync_config, since_token)
 
+    def last_read_event_id_for_room_and_user(self, room_id, user_id, ephemeral_by_room):
+        if room_id not in ephemeral_by_room:
+            return None
+        for e in ephemeral_by_room[room_id]:
+            if e['type'] != 'm.receipt':
+                continue
+            for receipt_event_id,val in e['content'].items():
+                if 'm.read' in val:
+                    if user_id in val['m.read']:
+                        return receipt_event_id
+        return None
+
     @defer.inlineCallbacks
     def full_state_sync(self, sync_config, timeline_since_token):
         """Get a sync for a client which is starting without any state.
@@ -265,6 +279,16 @@ class SyncHandler(BaseHandler):
             room_id, sync_config, now_token, since_token=timeline_since_token
         )
 
+        last_unread_event_id = self.last_read_event_id_for_room_and_user(
+            room_id, sync_config.user.to_string(), ephemeral_by_room
+        )
+
+        notifs = []
+        if last_unread_event_id:
+            notifs = yield self.store.get_unread_event_actions_by_room(
+                room_id, last_unread_event_id
+            )
+
         current_state = yield self.get_state_at(room_id, now_token)
 
         defer.returnValue(JoinedSyncResult(
@@ -275,6 +299,7 @@ class SyncHandler(BaseHandler):
             account_data=self.account_data_for_room(
                 room_id, tags_by_room, account_data_by_room
             ),
+            unread_notification_count=len(notifs)
         ))
 
     def account_data_for_user(self, account_data):
@@ -509,6 +534,7 @@ class SyncHandler(BaseHandler):
                     account_data=self.account_data_for_room(
                         room_id, tags_by_room, account_data_by_room
                     ),
+                    unread_notification_count=0
                 )
                 logger.debug("Result for room %s: %r", room_id, room_sync)
 

synapse/push/action_generator.py

@@ -45,5 +45,5 @@ class ActionGenerator:
             logger.info("actions for user %s: %s", uid, actions)
             if len(actions):
                 self.store.set_actions_for_event(
-                    event['event_id'], uid, None, actions
+                    event, uid, None, actions
                 )

synapse/rest/client/v2_alpha/sync.py

@@ -304,6 +304,7 @@ class SyncRestServlet(RestServlet):
             },
             "state": {"events": serialized_state},
             "account_data": {"events": account_data},
+            "unread_notification_count": room.unread_notification_count
         }
 
         if joined:

synapse/storage/event_actions.py

@@ -24,18 +24,67 @@ logger = logging.getLogger(__name__)
 
 class EventActionsStore(SQLBaseStore):
     @defer.inlineCallbacks
-    def set_actions_for_event(self, event_id, user_id, profile_tag, actions):
+    def set_actions_for_event(self, event, user_id, profile_tag, actions):
         actionsJson = json.dumps(actions)
 
         ret = yield self.runInteraction(
             "_set_actions_for_event",
             self._simple_upsert_txn,
             EventActionsTable.table_name,
-            {'event_id': event_id, 'user_id': user_id, 'profile_tag': profile_tag},
+            {
+                'room_id': event['room_id'],
+                'event_id': event['event_id'],
+                'user_id': user_id,
+                'profile_tag': profile_tag
+            },
             {'actions': actionsJson}
         )
         defer.returnValue(ret)
 
+    @defer.inlineCallbacks
+    def get_unread_event_actions_by_room(self, room_id, last_read_event_id):
+        #events = yield self._get_events(
+        #    [last_read_event_id],
+        #    check_redacted=False
+        #)
+
+        def _get_unread_event_actions_by_room(txn):
+            sql = (
+                "SELECT stream_ordering, topological_ordering"
+                " FROM events"
+                " WHERE room_id = ? AND event_id = ?"
+            )
+            txn.execute(
+                sql, (room_id, last_read_event_id)
+            )
+            results = txn.fetchall()
+            if len(results) == 0:
+                return []
+
+            stream_ordering = results[0][0]
+            topological_ordering = results[0][1]
+
+            sql = (
+                "SELECT ea.actions"
+                " FROM event_actions ea, events e"
+                " WHERE ea.room_id = e.room_id"
+                " AND ea.event_id = e.event_id"
+                " AND ea.room_id = ?"
+                " AND ("
+                "       e.topological_ordering > ?"
+                "       OR (e.topological_ordering == ? AND e.stream_ordering > ?)"
+                ")"
+            )
+            txn.execute(sql,
+                (room_id, topological_ordering, topological_ordering, stream_ordering)
+            )
+            return txn.fetchall()
+
+        ret = yield self.runInteraction(
+            "get_unread_event_actions_by_room",
+            _get_unread_event_actions_by_room
+        )
+        defer.returnValue(ret)
 
 class EventActionsTable(object):
     table_name = "event_actions"

synapse/storage/schema/delta/27/event_actions.sql

@@ -14,12 +14,13 @@
  */
 
 CREATE TABLE IF NOT EXISTS event_actions(
+    room_id TEXT NOT NULL,
     event_id TEXT NOT NULL,
     user_id TEXT NOT NULL,
     profile_tag VARCHAR(32),
     actions TEXT NOT NULL,
-    CONSTRAINT event_id_user_id_profile_tag_uniqueness UNIQUE (event_id, user_id, profile_tag)
+    CONSTRAINT event_id_user_id_profile_tag_uniqueness UNIQUE (room_id, event_id, user_id, profile_tag)
 );
 
 
-CREATE INDEX event_actions_event_id_user_id_profile_tag on event_actions(event_id, user_id, profile_tag);
+CREATE INDEX event_actions_room_id_event_id_user_id_profile_tag on event_actions(room_id, event_id, user_id, profile_tag);