glance/glance/image_cache/drivers/common.py

91 lines
2.7 KiB
Python

# Copyright 2023 OpenStack Foundation
# 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.
"""
Common code which will be used in SQLite and centralzed_db driver until SQLite
driver is removed from glance.
"""
from contextlib import contextmanager
import sqlite3
from eventlet import sleep
from eventlet import timeout
from oslo_log import log as logging
from glance.i18n import _LE
LOG = logging.getLogger(__name__)
DEFAULT_SQL_CALL_TIMEOUT = 2
def dict_factory(cur, row):
return {col[0]: row[idx] for idx, col in enumerate(cur.description)}
class SqliteConnection(sqlite3.Connection):
"""
SQLite DB Connection handler that plays well with eventlet,
slightly modified from Swift's similar code.
"""
def __init__(self, *args, **kwargs):
self.timeout_seconds = kwargs.get('timeout', DEFAULT_SQL_CALL_TIMEOUT)
kwargs['timeout'] = 0
sqlite3.Connection.__init__(self, *args, **kwargs)
def _timeout(self, call):
with timeout.Timeout(self.timeout_seconds):
while True:
try:
return call()
except sqlite3.OperationalError as e:
if 'locked' not in str(e):
raise
sleep(0.05)
def execute(self, *args, **kwargs):
return self._timeout(lambda: sqlite3.Connection.execute(
self, *args, **kwargs))
def commit(self):
return self._timeout(lambda: sqlite3.Connection.commit(self))
@contextmanager
def get_db(db_path):
"""
Returns a context manager that produces a database connection that
self-closes and calls rollback if an error occurs while using the
database connection
"""
conn = sqlite3.connect(db_path, check_same_thread=False,
factory=SqliteConnection)
conn.row_factory = sqlite3.Row
conn.text_factory = str
conn.execute('PRAGMA synchronous = NORMAL')
conn.execute('PRAGMA count_changes = OFF')
conn.execute('PRAGMA temp_store = MEMORY')
try:
yield conn
except sqlite3.DatabaseError as e:
msg = _LE("Error executing SQLite call. Got error: %s") % e
LOG.error(msg)
conn.rollback()
finally:
conn.close()