Remove legacy code of single user device resync api (#15418)

* Removed single-user resync usage and updated it to use multi-user counterpart

Signed-off-by: Alok Kumar Singh alokaks601@gmail.com

6 files changed, 26 insertions, 122 deletions

diff --git a/changelog.d/15418.misc b/changelog.d/15418.misc
new file mode 100644
index 0000000000..ca6f995a9c
--- /dev/null
+++ b/changelog.d/15418.misc
@@ -0,0 +1 @@
+Always use multi-user device resync replication endpoints.
\ No newline at end of file
diff --git a/synapse/handlers/device.py b/synapse/handlers/device.py
index ae1d9337ad..b9d3b7fbc6 100644
--- a/synapse/handlers/device.py
+++ b/synapse/handlers/device.py
@@ -14,7 +14,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import logging
-from http import HTTPStatus
 from typing import (
     TYPE_CHECKING,
     Any,
@@ -921,12 +920,8 @@ class DeviceListWorkerUpdater:
     def __init__(self, hs: "HomeServer"):
         from synapse.replication.http.devices import (
             ReplicationMultiUserDevicesResyncRestServlet,
-            ReplicationUserDevicesResyncRestServlet,
         )
 
-        self._user_device_resync_client = (
-            ReplicationUserDevicesResyncRestServlet.make_client(hs)
-        )
         self._multi_user_device_resync_client = (
             ReplicationMultiUserDevicesResyncRestServlet.make_client(hs)
         )
@@ -948,37 +943,7 @@ class DeviceListWorkerUpdater:
             # Shortcut empty requests
             return {}
 
-        try:
-            return await self._multi_user_device_resync_client(user_ids=user_ids)
-        except SynapseError as err:
-            if not (
-                err.code == HTTPStatus.NOT_FOUND and err.errcode == Codes.UNRECOGNIZED
-            ):
-                raise
-
-            # Fall back to single requests
-            result: Dict[str, Optional[JsonDict]] = {}
-            for user_id in user_ids:
-                result[user_id] = await self._user_device_resync_client(user_id=user_id)
-            return result
-
-    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
-            None when we weren't able to fetch the device info for some reason,
-            e.g. due to a connection problem.
-        """
-        return (await self.multi_user_device_resync([user_id]))[user_id]
+        return await self._multi_user_device_resync_client(user_ids=user_ids)
 
 
 class DeviceListUpdater(DeviceListWorkerUpdater):
@@ -1131,7 +1096,7 @@ class DeviceListUpdater(DeviceListWorkerUpdater):
                 )
 
             if resync:
-                await self.user_device_resync(user_id)
+                await self.multi_user_device_resync([user_id])
             else:
                 # Simply update the single device, since we know that is the only
                 # change (because of the single prev_id matching the current cache)
@@ -1198,10 +1163,9 @@ class DeviceListUpdater(DeviceListWorkerUpdater):
             for user_id in need_resync:
                 try:
                     # Try to resync the current user's devices list.
-                    result = await self.user_device_resync(
-                        user_id=user_id,
-                        mark_failed_as_stale=False,
-                    )
+                    result = (await self.multi_user_device_resync([user_id], False))[
+                        user_id
+                    ]
 
                     # user_device_resync only returns a result if it managed to
                     # successfully resync and update the database. Updating the table
@@ -1260,18 +1224,6 @@ class DeviceListUpdater(DeviceListWorkerUpdater):
 
         return result
 
-    async def user_device_resync(
-        self, user_id: str, mark_failed_as_stale: bool = True
-    ) -> Optional[JsonDict]:
-        result, failed = await self._user_device_resync_returning_failed(user_id)
-
-        if failed and mark_failed_as_stale:
-            # Mark the remote user's device list as stale so we know we need to retry
-            # it later.
-            await self.store.mark_remote_users_device_caches_as_stale((user_id,))
-
-        return result
-
     async def _user_device_resync_returning_failed(
         self, user_id: str
     ) -> Tuple[Optional[JsonDict], bool]:
diff --git a/synapse/handlers/devicemessage.py b/synapse/handlers/devicemessage.py
index 00c403db49..3caf9b31cc 100644
--- a/synapse/handlers/devicemessage.py
+++ b/synapse/handlers/devicemessage.py
@@ -25,7 +25,9 @@ from synapse.logging.opentracing import (
     log_kv,
     set_tag,
 )
-from synapse.replication.http.devices import ReplicationUserDevicesResyncRestServlet
+from synapse.replication.http.devices import (
+    ReplicationMultiUserDevicesResyncRestServlet,
+)
 from synapse.types import JsonDict, Requester, StreamKeyType, UserID, get_domain_from_id
 from synapse.util import json_encoder
 from synapse.util.stringutils import random_string
@@ -71,12 +73,12 @@ class DeviceMessageHandler:
         # sync. We do all device list resyncing on the master instance, so if
         # we're on a worker we hit the device resync replication API.
         if hs.config.worker.worker_app is None:
-            self._user_device_resync = (
-                hs.get_device_handler().device_list_updater.user_device_resync
+            self._multi_user_device_resync = (
+                hs.get_device_handler().device_list_updater.multi_user_device_resync
             )
         else:
-            self._user_device_resync = (
-                ReplicationUserDevicesResyncRestServlet.make_client(hs)
+            self._multi_user_device_resync = (
+                ReplicationMultiUserDevicesResyncRestServlet.make_client(hs)
             )
 
         # a rate limiter for room key requests.  The keys are
@@ -198,7 +200,7 @@ class DeviceMessageHandler:
             await self.store.mark_remote_users_device_caches_as_stale((sender_user_id,))
 
             # Immediately attempt a resync in the background
-            run_in_background(self._user_device_resync, user_id=sender_user_id)
+            run_in_background(self._multi_user_device_resync, user_ids=[sender_user_id])
 
     async def send_device_message(
         self,
diff --git a/synapse/handlers/federation_event.py b/synapse/handlers/federation_event.py
index 8d5be81a92..06609fab93 100644
--- a/synapse/handlers/federation_event.py
+++ b/synapse/handlers/federation_event.py
@@ -70,7 +70,9 @@ from synapse.logging.opentracing import (
     trace,
 )
 from synapse.metrics.background_process_metrics import run_as_background_process
-from synapse.replication.http.devices import ReplicationUserDevicesResyncRestServlet
+from synapse.replication.http.devices import (
+    ReplicationMultiUserDevicesResyncRestServlet,
+)
 from synapse.replication.http.federation import (
     ReplicationFederationSendEventsRestServlet,
 )
@@ -167,8 +169,8 @@ class FederationEventHandler:
 
         self._send_events = ReplicationFederationSendEventsRestServlet.make_client(hs)
         if hs.config.worker.worker_app:
-            self._user_device_resync = (
-                ReplicationUserDevicesResyncRestServlet.make_client(hs)
+            self._multi_user_device_resync = (
+                ReplicationMultiUserDevicesResyncRestServlet.make_client(hs)
             )
         else:
             self._device_list_updater = hs.get_device_handler().device_list_updater
@@ -1487,9 +1489,11 @@ class FederationEventHandler:
 
             # Immediately attempt a resync in the background
             if self._config.worker.worker_app:
-                await self._user_device_resync(user_id=sender)
+                await self._multi_user_device_resync(user_ids=[sender])
             else:
-                await self._device_list_updater.user_device_resync(sender)
+                await self._device_list_updater.multi_user_device_resync(
+                    user_ids=[sender]
+                )
         except Exception:
             logger.exception("Failed to resync device for %s", sender)
 
diff --git a/synapse/replication/http/devices.py b/synapse/replication/http/devices.py
index cc3929dcf5..f874f072f9 100644
--- a/synapse/replication/http/devices.py
+++ b/synapse/replication/http/devices.py
@@ -28,62 +28,6 @@ if TYPE_CHECKING:
 logger = logging.getLogger(__name__)
 
 
-class ReplicationUserDevicesResyncRestServlet(ReplicationEndpoint):
-    """Ask master to resync the device list for a user by contacting their
-    server.
-
-    This must happen on master so that the results can be correctly cached in
-    the database and streamed to workers.
-
-    Request format:
-
-        POST /_synapse/replication/user_device_resync/:user_id
-
-        {}
-
-    Response is equivalent to ` /_matrix/federation/v1/user/devices/:user_id`
-    response, e.g.:
-
-        {
-            "user_id": "@alice:example.org",
-            "devices": [
-                {
-                    "device_id": "JLAFKJWSCS",
-                    "keys": { ... },
-                    "device_display_name": "Alice's Mobile Phone"
-                }
-            ]
-        }
-    """
-
-    NAME = "user_device_resync"
-    PATH_ARGS = ("user_id",)
-    CACHE = False
-
-    def __init__(self, hs: "HomeServer"):
-        super().__init__(hs)
-
-        from synapse.handlers.device import DeviceHandler
-
-        handler = hs.get_device_handler()
-        assert isinstance(handler, DeviceHandler)
-        self.device_list_updater = handler.device_list_updater
-
-        self.store = hs.get_datastores().main
-        self.clock = hs.get_clock()
-
-    @staticmethod
-    async def _serialize_payload(user_id: str) -> JsonDict:  # type: ignore[override]
-        return {}
-
-    async def _handle_request(  # type: ignore[override]
-        self, request: Request, content: JsonDict, user_id: str
-    ) -> Tuple[int, Optional[JsonDict]]:
-        user_devices = await self.device_list_updater.user_device_resync(user_id)
-
-        return 200, user_devices
-
-
 class ReplicationMultiUserDevicesResyncRestServlet(ReplicationEndpoint):
     """Ask master to resync the device list for multiple users from the same
     remote server by contacting their server.
@@ -216,6 +160,5 @@ class ReplicationUploadKeysForUserRestServlet(ReplicationEndpoint):
 
 
 def register_servlets(hs: "HomeServer", http_server: HttpServer) -> None:
-    ReplicationUserDevicesResyncRestServlet(hs).register(http_server)
     ReplicationMultiUserDevicesResyncRestServlet(hs).register(http_server)
     ReplicationUploadKeysForUserRestServlet(hs).register(http_server)
diff --git a/tests/test_federation.py b/tests/test_federation.py
index 46d2f99eac..6d15ac7597 100644
--- a/tests/test_federation.py
+++ b/tests/test_federation.py
@@ -267,7 +267,9 @@ class MessageAcceptTests(unittest.HomeserverTestCase):
         # Resync the device list.
         device_handler = self.hs.get_device_handler()
         self.get_success(
-            device_handler.device_list_updater.user_device_resync(remote_user_id),
+            device_handler.device_list_updater.multi_user_device_resync(
+                [remote_user_id]
+            ),
         )
 
         # Retrieve the cross-signing keys for this user.