Batch up replication requests to request the resyncing of remote users's devices.

synapse/handlers/device.py

@@ -14,6 +14,7 @@
 # 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,
@@ -33,6 +34,7 @@
     Codes,
     FederationDeniedError,
     HttpResponseException,
+    InvalidAPICallError,
     RequestSendFailed,
     SynapseError,
 )
@@ -45,6 +47,7 @@
     JsonDict,
     StreamKeyType,
     StreamToken,
+    UserID,
     get_domain_from_id,
     get_verify_key_from_cross_signing_key,
 )
@@ -893,12 +896,41 @@ 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)
+        )
+
+    async def multi_user_device_resync(
+        self, user_ids: List[str], mark_failed_as_stale: bool = True
+    ) -> Dict[str, Optional[JsonDict]]:
+        """
+        Like `user_device_resync` but operates on multiple users **from the same origin**
+        at once.
+
+        Returns:
+            Dict from User ID to the same Dict as `user_device_resync`.
+        """
+        # TODO(BUG): mark_failed_as_stale is not sent.
+        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
@@ -914,6 +946,7 @@ async def user_device_resync(
             request:
             https://matrix.org/docs/spec/server_server/r0.1.2#get-matrix-federation-v1-user-devices-userid
         """
+        # TODO(BUG): mark_failed_as_stale is not sent.
         return await self._user_device_resync_client(user_id=user_id)
 
 
@@ -1160,6 +1193,31 @@ async def _maybe_retry_device_resync(self) -> None:
             # Allow future calls to retry resyncinc out of sync device lists.
             self._resync_retry_in_progress = False
 
+    async def multi_user_device_resync(
+        self, user_ids: List[str], mark_failed_as_stale: bool = True
+    ) -> Dict[str, Optional[JsonDict]]:
+        """
+        Like `user_device_resync` but operates on multiple users **from the same origin**
+        at once.
+
+        Returns:
+            Dict from User ID to the same Dict as `user_device_resync`.
+        """
+        if not user_ids:
+            return {}
+
+        origins = {UserID.from_string(user_id).domain for user_id in user_ids}
+
+        if len(origins) != 1:
+            raise InvalidAPICallError(f"Only one origin permitted, got {origins!r}")
+
+        result = {}
+        # TODO(Perf): Actually batch these up
+        for user_id in user_ids:
+            result[user_id] = await self.user_device_resync(user_id)
+
+        return result
+
     async def user_device_resync(
         self, user_id: str, mark_failed_as_stale: bool = True
     ) -> Optional[JsonDict]: