Files
zulip/zerver/lib/db.py
Anders Kaseorg 365fe0b3d5 python: Sort imports with isort.
Fixes #2665.

Regenerated by tabbott with `lint --fix` after a rebase and change in
parameters.

Note from tabbott: In a few cases, this converts technical debt in the
form of unsorted imports into different technical debt in the form of
our largest files having very long, ugly import sequences at the
start.  I expect this change will increase pressure for us to split
those files, which isn't a bad thing.

Signed-off-by: Anders Kaseorg <anders@zulip.com>
2020-06-11 16:45:32 -07:00

55 lines
2.0 KiB
Python

import time
from typing import Any, Callable, Dict, Iterable, List, Mapping, Optional, Sequence, TypeVar, Union
from psycopg2.extensions import connection, cursor
from psycopg2.sql import Composable
CursorObj = TypeVar('CursorObj', bound=cursor)
Query = Union[str, Composable]
Params = Union[Sequence[object], Mapping[str, object]]
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], CursorObj],
sql: Query,
params: ParamsT) -> CursorObj:
start = time.time()
try:
return action(sql, params)
finally:
stop = time.time()
duration = stop - start
self.connection.queries.append({
'time': f"{duration:.3f}",
})
class TimeTrackingCursor(cursor):
"""A psycopg2 cursor class that tracks the time spent executing queries."""
def execute(self, query: Query,
vars: Optional[Params]=None) -> 'TimeTrackingCursor':
return wrapper_execute(self, super().execute, query, vars)
def executemany(self, query: Query,
vars: Iterable[Params]) -> 'TimeTrackingCursor': # nocoverage
return wrapper_execute(self, super().executemany, query, vars)
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)
def cursor(self, *args: Any, **kwargs: Any) -> TimeTrackingCursor:
kwargs.setdefault('cursor_factory', TimeTrackingCursor)
return connection.cursor(self, *args, **kwargs)
def reset_queries() -> None:
from django.db import connections
for conn in connections.all():
if conn.connection is not None:
conn.connection.queries = []