From 76d40f490411ce1a0a208acb4242678b0cb4afb3 Mon Sep 17 00:00:00 2001
From: Erik Johnston <erik@matrix.org>
Date: Thu, 26 Jan 2017 16:39:33 +0000
Subject: [PATCH] Handle users leaving rooms

---
 synapse/handlers/device.py | 17 ++++++++++++++++-
 synapse/storage/devices.py |  8 ++++++++
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/synapse/handlers/device.py b/synapse/handlers/device.py
index a2ffd273bf..1116dfd27c 100644
--- a/synapse/handlers/device.py
+++ b/synapse/handlers/device.py
@@ -42,6 +42,8 @@ class DeviceHandler(BaseHandler):
             "user_devices", self.on_federation_query_user_devices,
         )
 
+        hs.get_distributor().observe("user_left_room", self.user_left_room)
+
     @defer.inlineCallbacks
     def check_device_registered(self, user_id, device_id,
                                 initial_device_display_name=None):
@@ -246,7 +248,11 @@ class DeviceHandler(BaseHandler):
             logger.warning("Got device list update edu for %r from %r", user_id, origin)
             return
 
-        logger.info("Got edu: %r", edu_content)
+        rooms = yield self.store.get_rooms_for_user(user_id)
+        if not rooms:
+            # We don't share any rooms with this user. Ignore update, as we
+            # probably won't get any further updates.
+            return
 
         with (yield self._remote_edue_linearizer.queue(user_id)):
             # If the prev id matches whats in our cache table, then we don't need
@@ -288,6 +294,15 @@ class DeviceHandler(BaseHandler):
             "devices": devices,
         })
 
+    @defer.inlineCallbacks
+    def user_left_room(self, user, room_id):
+        user_id = user.to_string()
+        rooms = yield self.store.get_rooms_for_user(user_id)
+        if not rooms:
+            # We no longer share rooms with this user, so we'll no longer
+            # receive device updates. Mark this in DB.
+            yield self.store.mark_remote_user_device_list_as_unsubscribed(user_id)
+
 
 def _update_device_from_client_ips(device, client_ips):
     ip = client_ips.get((device["user_id"], device["device_id"]), {})
diff --git a/synapse/storage/devices.py b/synapse/storage/devices.py
index cf38dbaa3c..1c48c3af99 100644
--- a/synapse/storage/devices.py
+++ b/synapse/storage/devices.py
@@ -150,6 +150,14 @@ class DeviceStore(SQLBaseStore):
             allow_none=True,
         )
 
+    def mark_remote_user_device_list_as_unsubscribed(self, user_id):
+        return self._simple_delete(
+            table="device_lists_remote_extremeties",
+            keyvalues={
+                "user_id": user_id,
+            },
+        )
+
     def update_remote_device_list_cache_entry(self, user_id, device_id, content,
                                               stream_id):
         """Updates a single user's device in the cache.