zulip/zerver/lib/db.py

58 lines
2.3 KiB
Python

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