Add a type hint for get_device_handler() and fix incorrect types. (#14055)

This was the last untyped handler from the HomeServer object. Since
it was being treated as Any (and thus unchecked) it was being used
incorrectly in a few places.

synapse/handlers/device.py

@@ -65,6 +65,8 @@ DELETE_STALE_DEVICES_INTERVAL_MS = 24 * 60 * 60 * 1000
 
 
 class DeviceWorkerHandler:
+    device_list_updater: "DeviceListWorkerUpdater"
+
     def __init__(self, hs: "HomeServer"):
         self.clock = hs.get_clock()
         self.hs = hs
@@ -76,6 +78,8 @@ class DeviceWorkerHandler:
         self.server_name = hs.hostname
         self._msc3852_enabled = hs.config.experimental.msc3852_enabled
 
+        self.device_list_updater = DeviceListWorkerUpdater(hs)
+
     @trace
     async def get_devices_by_user(self, user_id: str) -> List[JsonDict]:
         """
@@ -99,6 +103,19 @@ class DeviceWorkerHandler:
         log_kv(device_map)
         return devices
 
+    async def get_dehydrated_device(
+        self, user_id: str
+    ) -> Optional[Tuple[str, JsonDict]]:
+        """Retrieve the information for a dehydrated device.
+
+        Args:
+            user_id: the user whose dehydrated device we are looking for
+        Returns:
+            a tuple whose first item is the device ID, and the second item is
+            the dehydrated device information
+        """
+        return await self.store.get_dehydrated_device(user_id)
+
     @trace
     async def get_device(self, user_id: str, device_id: str) -> JsonDict:
         """Retrieve the given device
@@ -127,7 +144,7 @@ class DeviceWorkerHandler:
     @cancellable
     async def get_device_changes_in_shared_rooms(
         self, user_id: str, room_ids: Collection[str], from_token: StreamToken
-    ) -> Collection[str]:
+    ) -> Set[str]:
         """Get the set of users whose devices have changed who share a room with
         the given user.
         """
@@ -320,6 +337,8 @@ class DeviceWorkerHandler:
 
 
 class DeviceHandler(DeviceWorkerHandler):
+    device_list_updater: "DeviceListUpdater"
+
     def __init__(self, hs: "HomeServer"):
         super().__init__(hs)
 
@@ -606,19 +625,6 @@ class DeviceHandler(DeviceWorkerHandler):
             await self.delete_devices(user_id, [old_device_id])
         return device_id
 
-    async def get_dehydrated_device(
-        self, user_id: str
-    ) -> Optional[Tuple[str, JsonDict]]:
-        """Retrieve the information for a dehydrated device.
-
-        Args:
-            user_id: the user whose dehydrated device we are looking for
-        Returns:
-            a tuple whose first item is the device ID, and the second item is
-            the dehydrated device information
-        """
-        return await self.store.get_dehydrated_device(user_id)
-
     async def rehydrate_device(
         self, user_id: str, access_token: str, device_id: str
     ) -> dict:
@@ -882,7 +888,36 @@ def _update_device_from_client_ips(
     )
 
 
-class DeviceListUpdater:
+class DeviceListWorkerUpdater:
+    "Handles incoming device list updates from federation and contacts the main process over replication"
+
+    def __init__(self, hs: "HomeServer"):
+        from synapse.replication.http.devices import (
+            ReplicationUserDevicesResyncRestServlet,
+        )
+
+        self._user_device_resync_client = (
+            ReplicationUserDevicesResyncRestServlet.make_client(hs)
+        )
+
+    async def user_device_resync(
+        self, user_id: str, mark_failed_as_stale: bool = True
+    ) -> Optional[JsonDict]:
+        """Fetches all devices for a user and updates the device cache with them.
+
+        Args:
+            user_id: The user's id whose device_list will be updated.
+            mark_failed_as_stale: Whether to mark the user's device list as stale
+                if the attempt to resync failed.
+        Returns:
+            A dict with device info as under the "devices" in the result of this
+            request:
+            https://matrix.org/docs/spec/server_server/r0.1.2#get-matrix-federation-v1-user-devices-userid
+        """
+        return await self._user_device_resync_client(user_id=user_id)
+
+
+class DeviceListUpdater(DeviceListWorkerUpdater):
     "Handles incoming device list updates from federation and updates the DB"
 
     def __init__(self, hs: "HomeServer", device_handler: DeviceHandler):