osprofiler/osprofiler/sqlalchemy.py

76 lines
2.1 KiB
Python

# Copyright 2014 Mirantis Inc.
# All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, 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 contextlib
from osprofiler import profiler
_DISABLED = False
def disable():
"""Disable tracing of all DB queries. Reduce a lot size of profiles."""
global _DISABLED
_DISABLED = True
def enable():
"""add_tracing adds event listeners for sqlalchemy."""
global _DISABLED
_DISABLED = False
def add_tracing(sqlalchemy, engine, name):
"""Add tracing to all sqlalchemy calls."""
if not _DISABLED:
sqlalchemy.event.listen(engine, "before_cursor_execute",
_before_cursor_execute(name))
sqlalchemy.event.listen(engine, "after_cursor_execute",
_after_cursor_execute())
@contextlib.contextmanager
def wrap_session(sqlalchemy, sess):
with sess as s:
if not getattr(s.bind, "traced", False):
add_tracing(sqlalchemy, s.bind, "db")
s.bind.traced = True
yield s
def _before_cursor_execute(name):
"""Add listener that will send trace info before query is executed."""
def handler(conn, cursor, statement, params, context, executemany):
info = {"db": {
"statement": statement,
"params": params}
}
profiler.start(name, info=info)
return handler
def _after_cursor_execute():
"""Add listener that will send trace info after query is executed."""
def handler(conn, cursor, statement, params, context, executemany):
profiler.stop()
return handler