Add some type annotations in `synapse.storage` (#6987)

I cracked, and added some type definitions in synapse.storage.

1 files changed, 8 insertions, 5 deletions

diff --git a/synapse/storage/engines/sqlite.py b/synapse/storage/engines/sqlite.py
index 641e490697..2bfeefd54e 100644
--- a/synapse/storage/engines/sqlite.py
+++ b/synapse/storage/engines/sqlite.py
@@ -12,16 +12,16 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-
+import sqlite3
 import struct
 import threading
 
+from synapse.storage.engines import BaseDatabaseEngine
 
-class Sqlite3Engine(object):
-    single_threaded = True
 
+class Sqlite3Engine(BaseDatabaseEngine[sqlite3.Connection]):
     def __init__(self, database_module, database_config):
-        self.module = database_module
+        super().__init__(database_module, database_config)
 
         database = database_config.get("args", {}).get("database")
         self._is_in_memory = database in (None, ":memory:",)
@@ -32,6 +32,10 @@ class Sqlite3Engine(object):
         self._current_state_group_id_lock = threading.Lock()
 
     @property
+    def single_threaded(self) -> bool:
+        return True
+
+    @property
     def can_native_upsert(self):
         """
         Do we support native UPSERTs? This requires SQLite3 3.24+, plus some
@@ -68,7 +72,6 @@ class Sqlite3Engine(object):
         return sql
 
     def on_new_connection(self, db_conn):
-
         # We need to import here to avoid an import loop.
         from synapse.storage.prepare_database import prepare_database