Files
zulip/zerver/lib/db.py
Anders Kaseorg 72aeaf8d52 db: Split reset_queries into a new module zerver.lib.db_connections.
Fixes an import cycle that breaks mypy inference with django-stubs:

zproject.settings → zproject.computed_settings → zerver.lib.db →
django.db → django.db.backends.base.base →
django.db.backends.base.features → django.db.models.base →
django.db.models.options → django.contrib.contenttypes.fields →
django.contrib.contenttypes.models → confirmation.models → django.conf
→ zproject.settings

Signed-off-by: Anders Kaseorg <anders@zulip.com>
2024-04-17 16:49:03 -07:00

54 lines
1.7 KiB
Python

import time
from typing import Any, Callable, Dict, Iterable, List, Mapping, Sequence, TypeVar, Union
from psycopg2.extensions import connection, cursor
from psycopg2.sql import Composable
from typing_extensions import TypeAlias, override
CursorObj = TypeVar("CursorObj", bound=cursor)
Query: TypeAlias = Union[str, bytes, Composable]
Params: TypeAlias = Union[Sequence[object], Mapping[str, object], None]
ParamsT = TypeVar("ParamsT")
# Similar to the tracking done in Django's CursorDebugWrapper, but done at the
# psycopg2 cursor level so it works with SQLAlchemy.
def wrapper_execute(
self: CursorObj, action: Callable[[Query, ParamsT], None], sql: Query, params: ParamsT
) -> None:
start = time.time()
try:
action(sql, params)
finally:
stop = time.time()
duration = stop - start
assert isinstance(self.connection, TimeTrackingConnection)
self.connection.queries.append(
{
"time": f"{duration:.3f}",
}
)
class TimeTrackingCursor(cursor):
"""A psycopg2 cursor class that tracks the time spent executing queries."""
@override
def execute(self, query: Query, vars: Params = None) -> None:
wrapper_execute(self, super().execute, query, vars)
@override
def executemany(self, query: Query, vars_list: Iterable[Params]) -> None: # nocoverage
wrapper_execute(self, super().executemany, query, vars_list)
CursorT = TypeVar("CursorT", bound=cursor)
class TimeTrackingConnection(connection):
"""A psycopg2 connection class that uses TimeTrackingCursors."""
def __init__(self, *args: Any, **kwargs: Any) -> None:
self.queries: List[Dict[str, str]] = []
super().__init__(*args, **kwargs)