db: Use cursor_factory psycopg2 option.

Signed-off-by: Anders Kaseorg <anders@zulip.com>

zerver/lib/db.py

@@ -1,17 +1,5 @@
 import time
-from typing import (
-    Any,
-    Callable,
-    Dict,
-    Iterable,
-    List,
-    Mapping,
-    Optional,
-    Sequence,
-    TypeVar,
-    Union,
-    overload,
-)
+from typing import Any, Callable, Dict, Iterable, List, Mapping, Sequence, TypeVar, Union
 
 from psycopg2.extensions import connection, cursor
 from psycopg2.sql import Composable
@@ -59,30 +47,6 @@ class TimeTrackingConnection(connection):
         self.queries: List[Dict[str, str]] = []
         super().__init__(*args, **kwargs)
 
-    @overload
-    def cursor(
-        self,
-        name: str = ...,
-        *,
-        scrollable: Optional[bool] = ...,
-        withhold: bool = ...,
-    ) -> TimeTrackingCursor:
-        ...
-
-    @overload
-    def cursor(
-        self,
-        name: str = ...,
-        cursor_factory: Callable[..., CursorT] = ...,
-        scrollable: Optional[bool] = ...,
-        withhold: bool = ...,
-    ) -> CursorT:
-        ...
-
-    def cursor(self, *args: object, **kwargs: object) -> cursor:
-        kwargs.setdefault("cursor_factory", TimeTrackingCursor)
-        return super().cursor(*args, **kwargs)
-
 
 def reset_queries() -> None:
     from django.db import connections

zproject/computed_settings.py

@@ -9,7 +9,7 @@ from django.template.loaders import app_directories
 
 import zerver.lib.logging_util
 from scripts.lib.zulip_tools import get_tornado_ports
-from zerver.lib.db import TimeTrackingConnection
+from zerver.lib.db import TimeTrackingConnection, TimeTrackingCursor
 
 from .config import (
     DEPLOY_ROOT,
@@ -289,6 +289,7 @@ DATABASES: Dict[str, Dict[str, Any]] = {
         "CONN_MAX_AGE": 600,
         "OPTIONS": {
             "connection_factory": TimeTrackingConnection,
+            "cursor_factory": TimeTrackingCursor,
         },
     }
 }

zproject/test_extra_settings.py

@@ -4,7 +4,7 @@ from typing import Dict, List, Optional, Tuple
 import ldap
 from django_auth_ldap.config import LDAPSearch
 
-from zerver.lib.db import TimeTrackingConnection
+from zerver.lib.db import TimeTrackingConnection, TimeTrackingCursor
 from zerver.lib.types import SAMLIdPConfigDict
 
 from .config import DEPLOY_ROOT, get_from_file_if_exists
@@ -37,7 +37,10 @@ DATABASES["default"] = {
     "SCHEMA": "zulip",
     "ENGINE": "django.db.backends.postgresql",
     "TEST_NAME": "django_zulip_tests",
-    "OPTIONS": {"connection_factory": TimeTrackingConnection},
+    "OPTIONS": {
+        "connection_factory": TimeTrackingConnection,
+        "cursor_factory": TimeTrackingCursor,
+    },
 }