1 files changed, 33 insertions, 7 deletions
diff --git a/synapse/storage/databases/main/signatures.py b/synapse/storage/databases/main/signatures.py
index be191dd870..c8c67953e4 100644
--- a/synapse/storage/databases/main/signatures.py
+++ b/synapse/storage/databases/main/signatures.py
@@ -13,9 +13,12 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from typing import Dict, Iterable, List, Tuple
+
 from unpaddedbase64 import encode_base64
 
 from synapse.storage._base import SQLBaseStore
+from synapse.storage.types import Cursor
 from synapse.util.caches.descriptors import cached, cachedList
 
 
@@ -29,16 +32,37 @@ class SignatureWorkerStore(SQLBaseStore):
     @cachedList(
         cached_method_name="get_event_reference_hash", list_name="event_ids", num_args=1
     )
-    def get_event_reference_hashes(self, event_ids):
+    async def get_event_reference_hashes(
+        self, event_ids: Iterable[str]
+    ) -> Dict[str, Dict[str, bytes]]:
+        """Get all hashes for given events.
+
+        Args:
+            event_ids: The event IDs to get hashes for.
+
+        Returns:
+             A mapping of event ID to a mapping of algorithm to hash.
+        """
+
         def f(txn):
             return {
                 event_id: self._get_event_reference_hashes_txn(txn, event_id)
                 for event_id in event_ids
             }
 
-        return self.db_pool.runInteraction("get_event_reference_hashes", f)
+        return await self.db_pool.runInteraction("get_event_reference_hashes", f)
 
-    async def add_event_hashes(self, event_ids):
+    async def add_event_hashes(
+        self, event_ids: Iterable[str]
+    ) -> List[Tuple[str, Dict[str, str]]]:
+        """
+
+        Args:
+            event_ids: The event IDs
+
+        Returns:
+            A list of tuples of event ID and a mapping of algorithm to base-64 encoded hash.
+        """
         hashes = await self.get_event_reference_hashes(event_ids)
         hashes = {
             e_id: {k: encode_base64(v) for k, v in h.items() if k == "sha256"}
@@ -47,13 +71,15 @@ class SignatureWorkerStore(SQLBaseStore):
 
         return list(hashes.items())
 
-    def _get_event_reference_hashes_txn(self, txn, event_id):
+    def _get_event_reference_hashes_txn(
+        self, txn: Cursor, event_id: str
+    ) -> Dict[str, bytes]:
         """Get all the hashes for a given PDU.
         Args:
-            txn (cursor):
-            event_id (str): Id for the Event.
+            txn:
+            event_id: Id for the Event.
         Returns:
-            A dict[unicode, bytes] of algorithm -> hash.
+            A mapping of algorithm -> hash.
         """
         query = (
             "SELECT algorithm, hash"