Track notification counts per thread (implement MSC3773). (#13776)

When retrieving counts of notifications segment the results based on the
thread ID, but choose whether to return them as individual threads or as
a single summed field by letting the client opt-in via a sync flag.

The summarization code is also updated to be per thread, instead of per
room.

changelog.d/13776.feature

@@ -0,0 +1 @@
+Experimental support for thread-specific notifications ([MSC3773](https://github.com/matrix-org/matrix-spec-proposals/pull/3773)).

synapse/api/constants.py

@@ -31,6 +31,9 @@
 # the maximum length for a user id is 255 characters
 MAX_USERID_LENGTH = 255
 
+# Constant value used for the pseudo-thread which is the main timeline.
+MAIN_TIMELINE: Final = "main"
+
 
 class Membership:
 

synapse/api/filtering.py

@@ -84,6 +84,7 @@
         "contains_url": {"type": "boolean"},
         "lazy_load_members": {"type": "boolean"},
         "include_redundant_members": {"type": "boolean"},
+        "org.matrix.msc3773.unread_thread_notifications": {"type": "boolean"},
         # Include or exclude events with the provided labels.
         # cf https://github.com/matrix-org/matrix-doc/pull/2326
         "org.matrix.labels": {"type": "array", "items": {"type": "string"}},
@@ -240,6 +241,9 @@ def lazy_load_members(self) -> bool:
     def include_redundant_members(self) -> bool:
         return self._room_state_filter.include_redundant_members
 
+    def unread_thread_notifications(self) -> bool:
+        return self._room_timeline_filter.unread_thread_notifications
+
     async def filter_presence(
         self, events: Iterable[UserPresenceState]
     ) -> List[UserPresenceState]:
@@ -304,6 +308,12 @@ def __init__(self, hs: "HomeServer", filter_json: JsonDict):
         self.include_redundant_members = filter_json.get(
             "include_redundant_members", False
         )
+        if hs.config.experimental.msc3773_enabled:
+            self.unread_thread_notifications: bool = filter_json.get(
+                "org.matrix.msc3773.unread_thread_notifications", False
+            )
+        else:
+            self.unread_thread_notifications = False
 
         self.types = filter_json.get("types", None)
         self.not_types = filter_json.get("not_types", [])

synapse/config/experimental.py

@@ -99,6 +99,8 @@ def read_config(self, config: JsonDict, **kwargs: Any) -> None:
         self.msc3771_enabled: bool = experimental.get("msc3771_enabled", False)
         # MSC3772: A push rule for mutual relations.
         self.msc3772_enabled: bool = experimental.get("msc3772_enabled", False)
+        # MSC3773: Thread notifications
+        self.msc3773_enabled: bool = experimental.get("msc3773_enabled", False)
 
         # MSC3715: dir param on /relations.
         self.msc3715_enabled: bool = experimental.get("msc3715_enabled", False)

synapse/handlers/sync.py

@@ -40,7 +40,7 @@
 from synapse.logging.context import current_context
 from synapse.logging.opentracing import SynapseTags, log_kv, set_tag, start_active_span
 from synapse.push.clientformat import format_push_rules_for_user
-from synapse.storage.databases.main.event_push_actions import NotifCounts
+from synapse.storage.databases.main.event_push_actions import RoomNotifCounts
 from synapse.storage.roommember import MemberSummary
 from synapse.storage.state import StateFilter
 from synapse.types import (
@@ -128,6 +128,7 @@ class JoinedSyncResult:
     ephemeral: List[JsonDict]
     account_data: List[JsonDict]
     unread_notifications: JsonDict
+    unread_thread_notifications: JsonDict
     summary: Optional[JsonDict]
     unread_count: int
 
@@ -278,6 +279,8 @@ def __init__(self, hs: "HomeServer"):
 
         self.rooms_to_exclude = hs.config.server.rooms_to_exclude_from_sync
 
+        self._msc3773_enabled = hs.config.experimental.msc3773_enabled
+
     async def wait_for_sync_for_user(
         self,
         requester: Requester,
@@ -1288,7 +1291,7 @@ async def _find_missing_partial_state_memberships(
 
     async def unread_notifs_for_room_id(
         self, room_id: str, sync_config: SyncConfig
-    ) -> NotifCounts:
+    ) -> RoomNotifCounts:
         with Measure(self.clock, "unread_notifs_for_room_id"):
 
             return await self.store.get_unread_event_push_actions_by_room_for_user(
@@ -2353,17 +2356,44 @@ async def _generate_room_entry(
                     ephemeral=ephemeral,
                     account_data=account_data_events,
                     unread_notifications=unread_notifications,
+                    unread_thread_notifications={},
                     summary=summary,
                     unread_count=0,
                 )
 
                 if room_sync or always_include:
                     notifs = await self.unread_notifs_for_room_id(room_id, sync_config)
 
-                    unread_notifications["notification_count"] = notifs.notify_count
-                    unread_notifications["highlight_count"] = notifs.highlight_count
+                    # Notifications for the main timeline.
+                    notify_count = notifs.main_timeline.notify_count
+                    highlight_count = notifs.main_timeline.highlight_count
+                    unread_count = notifs.main_timeline.unread_count
 
-                    room_sync.unread_count = notifs.unread_count
+                    # Check the sync configuration.
+                    if (
+                        self._msc3773_enabled
+                        and sync_config.filter_collection.unread_thread_notifications()
+                    ):
+                        # And add info for each thread.
+                        room_sync.unread_thread_notifications = {
+                            thread_id: {
+                                "notification_count": thread_notifs.notify_count,
+                                "highlight_count": thread_notifs.highlight_count,
+                            }
+                            for thread_id, thread_notifs in notifs.threads.items()
+                            if thread_id is not None
+                        }
+
+                    else:
+                        # Combine the unread counts for all threads and main timeline.
+                        for thread_notifs in notifs.threads.values():
+                            notify_count += thread_notifs.notify_count
+                            highlight_count += thread_notifs.highlight_count
+                            unread_count += thread_notifs.unread_count
+
+                    unread_notifications["notification_count"] = notify_count
+                    unread_notifications["highlight_count"] = highlight_count
+                    room_sync.unread_count = unread_count
 
                     sync_result_builder.joined.append(room_sync)
 

synapse/push/bulk_push_rule_evaluator.py

@@ -31,7 +31,7 @@
 
 from prometheus_client import Counter
 
-from synapse.api.constants import EventTypes, Membership, RelationTypes
+from synapse.api.constants import MAIN_TIMELINE, EventTypes, Membership, RelationTypes
 from synapse.event_auth import auth_types_for_event, get_user_power_level
 from synapse.events import EventBase, relation_from_event
 from synapse.events.snapshot import EventContext
@@ -280,7 +280,7 @@ async def action_for_event_by_user(
         # If the event does not have a relation, then cannot have any mutual
         # relations or thread ID.
         relations = {}
-        thread_id = "main"
+        thread_id = MAIN_TIMELINE
         if relation:
             relations = await self._get_mutual_relations(
                 relation.parent_id,

synapse/push/push_tools.py

@@ -39,15 +39,20 @@ async def get_room_unread_count(room_id: str) -> None:
     await concurrently_execute(get_room_unread_count, joins, 10)
 
     for notifs in room_notifs:
-        if notifs.notify_count == 0:
+        # Combine the counts from all the threads.
+        notify_count = notifs.main_timeline.notify_count + sum(
+            n.notify_count for n in notifs.threads.values()
+        )
+
+        if notify_count == 0:
             continue
 
         if group_by_room:
             # return one badge count per conversation
             badge += 1
         else:
             # increment the badge count by the number of unread messages in the room
-            badge += notifs.notify_count
+            badge += notify_count
     return badge
 
 

synapse/rest/client/sync.py

@@ -509,6 +509,10 @@ async def encode_room(
             ephemeral_events = room.ephemeral
             result["ephemeral"] = {"events": ephemeral_events}
             result["unread_notifications"] = room.unread_notifications
+            if room.unread_thread_notifications:
+                result[
+                    "org.matrix.msc3773.unread_thread_notifications"
+                ] = room.unread_thread_notifications
             result["summary"] = room.summary
             if self._msc2654_enabled:
                 result["org.matrix.msc2654.unread_count"] = room.unread_count

synapse/rest/client/versions.py

@@ -103,8 +103,9 @@ def on_GET(self, request: Request) -> Tuple[int, JsonDict]:
                     "org.matrix.msc3030": self.config.experimental.msc3030_enabled,
                     # Adds support for thread relations, per MSC3440.
                     "org.matrix.msc3440.stable": True,  # TODO: remove when "v1.3" is added above
-                    # Support for thread read receipts.
+                    # Support for thread read receipts & notification counts.
                     "org.matrix.msc3771": self.config.experimental.msc3771_enabled,
+                    "org.matrix.msc3773": self.config.experimental.msc3773_enabled,
                     # Allows moderators to fetch redacted event content as described in MSC2815
                     "fi.mau.msc2815": self.config.experimental.msc2815_enabled,
                     # Adds support for login token requests as per MSC3882

synapse/storage/database.py

@@ -94,7 +94,7 @@
     "event_search": "event_search_event_id_idx",
     "local_media_repository_thumbnails": "local_media_repository_thumbnails_method_idx",
     "remote_media_cache_thumbnails": "remote_media_repository_thumbnails_method_idx",
-    "event_push_summary": "event_push_summary_unique_index",
+    "event_push_summary": "event_push_summary_unique_index2",
     "receipts_linearized": "receipts_linearized_unique_index",
     "receipts_graph": "receipts_graph_unique_index",
 }