1 files changed, 71 insertions, 2 deletions

diff --git a/synapse/federation/send_queue.py b/synapse/federation/send_queue.py
index 04d04a4457..0240b339b0 100644
--- a/synapse/federation/send_queue.py
+++ b/synapse/federation/send_queue.py
@@ -55,7 +55,12 @@ class FederationRemoteSendQueue(object):
         self.is_mine_id = hs.is_mine_id
 
         self.presence_map = {}  # Pending presence map user_id -> UserPresenceState
-        self.presence_changed = SortedDict()  # Stream position -> user_id
+        self.presence_changed = SortedDict()  # Stream position -> list[user_id]
+
+        # Stores the destinations we need to explicitly send presence to about a
+        # given user.
+        # Stream position -> (user_id, destinations)
+        self.presence_destinations = SortedDict()
 
         self.keyed_edu = {}  # (destination, key) -> EDU
         self.keyed_edu_changed = SortedDict()  # stream position -> (destination, key)
@@ -77,7 +82,7 @@ class FederationRemoteSendQueue(object):
 
         for queue_name in [
             "presence_map", "presence_changed", "keyed_edu", "keyed_edu_changed",
-            "edus", "device_messages", "pos_time",
+            "edus", "device_messages", "pos_time", "presence_destinations",
         ]:
             register(queue_name, getattr(self, queue_name))
 
@@ -121,6 +126,15 @@ class FederationRemoteSendQueue(object):
                 for user_id in uids
             )
 
+            keys = self.presence_destinations.keys()
+            i = self.presence_destinations.bisect_left(position_to_delete)
+            for key in keys[:i]:
+                del self.presence_destinations[key]
+
+            user_ids.update(
+                user_id for user_id, _ in self.presence_destinations.values()
+            )
+
             to_del = [
                 user_id for user_id in self.presence_map if user_id not in user_ids
             ]
@@ -209,6 +223,20 @@ class FederationRemoteSendQueue(object):
 
         self.notifier.on_new_replication_data()
 
+    def send_presence_to_destinations(self, states, destinations):
+        """As per FederationSender
+
+        Args:
+            states (list[UserPresenceState])
+            destinations (list[str])
+        """
+        for state in states:
+            pos = self._next_pos()
+            self.presence_map.update({state.user_id: state for state in states})
+            self.presence_destinations[pos] = (state.user_id, destinations)
+
+        self.notifier.on_new_replication_data()
+
     def send_device_messages(self, destination):
         """As per FederationSender"""
         pos = self._next_pos()
@@ -261,6 +289,16 @@ class FederationRemoteSendQueue(object):
                 state=self.presence_map[user_id],
             )))
 
+        # Fetch presence to send to destinations
+        i = self.presence_destinations.bisect_right(from_token)
+        j = self.presence_destinations.bisect_right(to_token) + 1
+
+        for pos, (user_id, dests) in self.presence_destinations.items()[i:j]:
+            rows.append((pos, PresenceDestinationsRow(
+                state=self.presence_map[user_id],
+                destinations=list(dests),
+            )))
+
         # Fetch changes keyed edus
         i = self.keyed_edu_changed.bisect_right(from_token)
         j = self.keyed_edu_changed.bisect_right(to_token) + 1
@@ -357,6 +395,29 @@ class PresenceRow(BaseFederationRow, namedtuple("PresenceRow", (
         buff.presence.append(self.state)
 
 
+class PresenceDestinationsRow(BaseFederationRow, namedtuple("PresenceDestinationsRow", (
+    "state",  # UserPresenceState
+    "destinations",  # list[str]
+))):
+    TypeId = "pd"
+
+    @staticmethod
+    def from_data(data):
+        return PresenceDestinationsRow(
+            state=UserPresenceState.from_dict(data["state"]),
+            destinations=data["dests"],
+        )
+
+    def to_data(self):
+        return {
+            "state": self.state.as_dict(),
+            "dests": self.destinations,
+        }
+
+    def add_to_buffer(self, buff):
+        buff.presence_destinations.append((self.state, self.destinations))
+
+
 class KeyedEduRow(BaseFederationRow, namedtuple("KeyedEduRow", (
     "key",  # tuple(str) - the edu key passed to send_edu
     "edu",  # Edu
@@ -428,6 +489,7 @@ TypeToRow = {
     Row.TypeId: Row
     for Row in (
         PresenceRow,
+        PresenceDestinationsRow,
         KeyedEduRow,
         EduRow,
         DeviceRow,
@@ -437,6 +499,7 @@ TypeToRow = {
 
 ParsedFederationStreamData = namedtuple("ParsedFederationStreamData", (
     "presence",  # list(UserPresenceState)
+    "presence_destinations",  # list of tuples of UserPresenceState and destinations
     "keyed_edus",  # dict of destination -> { key -> Edu }
     "edus",  # dict of destination -> [Edu]
     "device_destinations",  # set of destinations
@@ -458,6 +521,7 @@ def process_rows_for_federation(transaction_queue, rows):
 
     buff = ParsedFederationStreamData(
         presence=[],
+        presence_destinations=[],
         keyed_edus={},
         edus={},
         device_destinations=set(),
@@ -476,6 +540,11 @@ def process_rows_for_federation(transaction_queue, rows):
     if buff.presence:
         transaction_queue.send_presence(buff.presence)
 
+    for state, destinations in buff.presence_destinations:
+        transaction_queue.send_presence_to_destinations(
+            states=[state], destinations=destinations,
+        )
+
     for destination, edu_map in iteritems(buff.keyed_edus):
         for key, edu in edu_map.items():
             transaction_queue.send_edu(edu, key)