Send down device list change notif when member leaves/rejoins room

3 files changed, 55 insertions, 14 deletions

diff --git a/synapse/handlers/device.py b/synapse/handlers/device.py
index ed60d494ff..be120b2f34 100644
--- a/synapse/handlers/device.py
+++ b/synapse/handlers/device.py
@@ -320,7 +320,7 @@ class DeviceHandler(BaseHandler):
 
                 # check if this member has changed since any of the extremities
                 # at the stream_ordering, and add them to the list if so.
-                for state_dict in prev_state_ids.values():
+                for state_dict in prev_state_ids.itervalues():
                     prev_event_id = state_dict.get(key, None)
                     if not prev_event_id or prev_event_id != event_id:
                         possibly_changed.add(state_key)
diff --git a/synapse/handlers/sync.py b/synapse/handlers/sync.py
index e6df1819b9..4ee6109cf8 100644
--- a/synapse/handlers/sync.py
+++ b/synapse/handlers/sync.py
@@ -108,6 +108,16 @@ class InvitedSyncResult(collections.namedtuple("InvitedSyncResult", [
         return True
 
 
+class DeviceLists(collections.namedtuple("DeviceLists", [
+    "changed",   # list of user_ids whose devices may have changed
+    "left",      # list of user_ids whose devices we no longer track
+])):
+    __slots__ = []
+
+    def __nonzero__(self):
+        return bool(self.changed or self.left)
+
+
 class SyncResult(collections.namedtuple("SyncResult", [
     "next_batch",  # Token for the next sync
     "presence",  # List of presence events for the user.
@@ -535,7 +545,7 @@ class SyncHandler(object):
         res = yield self._generate_sync_entry_for_rooms(
             sync_result_builder, account_data_by_room
         )
-        newly_joined_rooms, newly_joined_users = res
+        newly_joined_rooms, newly_joined_users, _, newly_left_users = res
 
         block_all_presence_data = (
             since_token is None and
@@ -549,7 +559,11 @@ class SyncHandler(object):
         yield self._generate_sync_entry_for_to_device(sync_result_builder)
 
         device_lists = yield self._generate_sync_entry_for_device_list(
-            sync_result_builder
+            sync_result_builder,
+            newly_joined_rooms=newly_joined_rooms,
+            newly_joined_users=newly_joined_users,
+            newly_left_rooms=[],
+            newly_left_users=newly_left_users,
         )
 
         device_id = sync_config.device_id
@@ -574,7 +588,9 @@ class SyncHandler(object):
 
     @measure_func("_generate_sync_entry_for_device_list")
     @defer.inlineCallbacks
-    def _generate_sync_entry_for_device_list(self, sync_result_builder):
+    def _generate_sync_entry_for_device_list(self, sync_result_builder,
+                                             newly_joined_rooms, newly_joined_users,
+                                             newly_left_rooms, newly_left_users):
         user_id = sync_result_builder.sync_config.user.to_string()
         since_token = sync_result_builder.since_token
 
@@ -582,16 +598,32 @@ class SyncHandler(object):
             changed = yield self.store.get_user_whose_devices_changed(
                 since_token.device_list_key
             )
-            if not changed:
-                defer.returnValue([])
+
+            # TODO: Check that these users are actually new, i.e. either they
+            # weren't in the previous sync *or* they left and rejoined.
+            changed.update(newly_joined_users)
+
+            # TODO: Add the members from newly_*_rooms
+
+            if not changed and not newly_left_users:
+                defer.returnValue(DeviceLists(
+                    changed=[],
+                    left=newly_left_users,
+                ))
 
             users_who_share_room = yield self.store.get_users_who_share_room_with_user(
                 user_id
             )
 
-            defer.returnValue(users_who_share_room & changed)
+            defer.returnValue(DeviceLists(
+                changed=users_who_share_room & changed,
+                left=set(newly_left_users) - users_who_share_room,
+            ))
         else:
-            defer.returnValue([])
+            defer.returnValue(DeviceLists(
+                changed=[],
+                left=[],
+            ))
 
     @defer.inlineCallbacks
     def _generate_sync_entry_for_to_device(self, sync_result_builder):
@@ -755,8 +787,8 @@ class SyncHandler(object):
             account_data_by_room(dict): Dictionary of per room account data
 
         Returns:
-            Deferred(tuple): Returns a 2-tuple of
-            `(newly_joined_rooms, newly_joined_users)`
+            Deferred(tuple): Returns a 4-tuple of
+            `(newly_joined_rooms, newly_joined_users, newly_left_rooms, newly_left_users)`
         """
         user_id = sync_result_builder.sync_config.user.to_string()
         block_all_room_ephemeral = (
@@ -787,7 +819,7 @@ class SyncHandler(object):
                     )
                     if not tags_by_room:
                         logger.debug("no-oping sync")
-                        defer.returnValue(([], []))
+                        defer.returnValue(([], [], [], []))
 
         ignored_account_data = yield self.store.get_global_account_data_by_type_for_user(
             "m.ignored_user_list", user_id=user_id,
@@ -828,17 +860,24 @@ class SyncHandler(object):
 
         # Now we want to get any newly joined users
         newly_joined_users = set()
+        newly_left_users = set()
         if since_token:
             for joined_sync in sync_result_builder.joined:
                 it = itertools.chain(
-                    joined_sync.timeline.events, joined_sync.state.values()
+                    joined_sync.timeline.events, joined_sync.state.itervalues()
                 )
                 for event in it:
                     if event.type == EventTypes.Member:
                         if event.membership == Membership.JOIN:
                             newly_joined_users.add(event.state_key)
+                        else:
+                            prev_content = event.unsigned.get("prev_content", {})
+                            prev_membership = prev_content.get("membership", None)
+                            if prev_membership == Membership.JOIN:
+                                newly_left_users.add(event.state_key)
 
-        defer.returnValue((newly_joined_rooms, newly_joined_users))
+        newly_left_users -= newly_joined_users
+        defer.returnValue((newly_joined_rooms, newly_joined_users, [], newly_left_users))
 
     @defer.inlineCallbacks
     def _have_rooms_changed(self, sync_result_builder):
@@ -1259,6 +1298,7 @@ class SyncResultBuilder(object):
         self.invited = []
         self.archived = []
         self.device = []
+        self.to_device = []
 
 
 class RoomSyncResultBuilder(object):
diff --git a/synapse/rest/client/v2_alpha/sync.py b/synapse/rest/client/v2_alpha/sync.py
index 2939896f44..978af9c280 100644
--- a/synapse/rest/client/v2_alpha/sync.py
+++ b/synapse/rest/client/v2_alpha/sync.py
@@ -189,7 +189,8 @@ class SyncRestServlet(RestServlet):
             "account_data": {"events": sync_result.account_data},
             "to_device": {"events": sync_result.to_device},
             "device_lists": {
-                "changed": list(sync_result.device_lists),
+                "changed": list(sync_result.device_lists.changed),
+                "left": list(sync_result.device_lists.left),
             },
             "presence": SyncRestServlet.encode_presence(
                 sync_result.presence, time_now