Revert "Improve perf of sync device lists" (#17207)

Reverts element-hq/synapse#17191

1 files changed, 15 insertions, 2 deletions

diff --git a/synapse/storage/databases/main/devices.py b/synapse/storage/databases/main/devices.py

index d98f0593bc..8dbcb3f5a0 100644
--- a/synapse/storage/databases/main/devices.py
+++ b/synapse/storage/databases/main/devices.py
@@ -70,7 +70,10 @@ from synapse.types import (
 from synapse.util import json_decoder, json_encoder
 from synapse.util.caches.descriptors import cached, cachedList
 from synapse.util.caches.lrucache import LruCache
-from synapse.util.caches.stream_change_cache import StreamChangeCache
+from synapse.util.caches.stream_change_cache import (
+    AllEntitiesChangedResult,
+    StreamChangeCache,
+)
 from synapse.util.cancellation import cancellable
 from synapse.util.iterutils import batch_iter
 from synapse.util.stringutils import shortstr
@@ -829,6 +832,16 @@ class DeviceWorkerStore(RoomMemberWorkerStore, EndToEndKeyWorkerStore):
         )
         return {device[0]: db_to_json(device[1]) for device in devices}
 
+    def get_cached_device_list_changes(
+        self,
+        from_key: int,
+    ) -> AllEntitiesChangedResult:
+        """Get set of users whose devices have changed since `from_key`, or None
+        if that information is not in our cache.
+        """
+
+        return self._device_list_stream_cache.get_all_entities_changed(from_key)
+
     @cancellable
     async def get_all_devices_changed(
         self,
@@ -1462,7 +1475,7 @@ class DeviceWorkerStore(RoomMemberWorkerStore, EndToEndKeyWorkerStore):
 
         sql = """
             SELECT DISTINCT user_id FROM device_lists_changes_in_room
-            WHERE {clause} AND stream_id > ?
+            WHERE {clause} AND stream_id >= ?
         """
 
         def _get_device_list_changes_in_rooms_txn(