Rename _get_e2e_device_keys_txn (#8222)

... to `_get_e2e_device_keys_and_signatures_txn`, to better reflect what it
does.

Author: richvdh

changelog.d/8222.misc

@@ -0,0 +1 @@
+Refactor queries for device keys and cross-signatures.

synapse/storage/databases/main/devices.py

@@ -256,8 +256,8 @@ async def _get_device_update_edus_by_remote(
         """
         devices = (
             await self.db_pool.runInteraction(
-                "_get_e2e_device_keys_txn",
-                self._get_e2e_device_keys_txn,
+                "get_e2e_device_keys_and_signatures_txn",
+                self._get_e2e_device_keys_and_signatures_txn,
                 query_map.keys(),
                 include_all_devices=True,
                 include_deleted_devices=True,

synapse/storage/databases/main/end_to_end_keys.py

@@ -51,7 +51,7 @@ def _get_e2e_device_keys_for_federation_query_txn(
     ) -> Tuple[int, List[JsonDict]]:
         now_stream_id = self.get_device_stream_token()
 
-        devices = self._get_e2e_device_keys_txn(txn, [(user_id, None)])
+        devices = self._get_e2e_device_keys_and_signatures_txn(txn, [(user_id, None)])
 
         if devices:
             user_devices = devices[user_id]
@@ -96,7 +96,9 @@ async def get_e2e_device_keys_for_cs_api(
             return {}
 
         results = await self.db_pool.runInteraction(
-            "get_e2e_device_keys", self._get_e2e_device_keys_txn, query_list,
+            "get_e2e_device_keys_and_signatures_txn",
+            self._get_e2e_device_keys_and_signatures_txn,
+            query_list,
         )
 
         # Build the result structure, un-jsonify the results, and add the
@@ -120,9 +122,9 @@ async def get_e2e_device_keys_for_cs_api(
         return rv
 
     @trace
-    def _get_e2e_device_keys_txn(
+    def _get_e2e_device_keys_and_signatures_txn(
         self, txn, query_list, include_all_devices=False, include_deleted_devices=False
-    ):
+    ) -> Dict[str, Dict[str, Optional[Dict]]]:
         set_tag("include_all_devices", include_all_devices)
         set_tag("include_deleted_devices", include_deleted_devices)