# mysql/gaerdbms.py
# Copyright (C) 2005-2021 the SQLAlchemy authors and contributors
# <see AUTHORS file>
#
# This module is part of SQLAlchemy and is released under
# the MIT License: http://www.opensource.org/licenses/mit-license.php
r"""
.. dialect:: mysql+gaerdbms
:name: Google Cloud SQL
:dbapi: rdbms
:connectstring: mysql+gaerdbms:///<dbname>?instance=<instancename>
:url: https://developers.google.com/appengine/docs/python/cloud-sql/developers-guide
This dialect is based primarily on the :mod:`.mysql.mysqldb` dialect with
minimal changes.
.. deprecated:: 1.0 This dialect is **no longer necessary** for
Google Cloud SQL; the MySQLdb dialect can be used directly.
Cloud SQL now recommends creating connections via the
mysql dialect using the URL format
``mysql+mysqldb://root@/<dbname>?unix_socket=/cloudsql/<projectid>:<instancename>``
Pooling
-------
Google App Engine connections appear to be randomly recycled,
so the dialect does not pool connections. The :class:`.NullPool`
implementation is installed within the :class:`_engine.Engine` by
default.
""" # noqa
import os
import re
from sqlalchemy.util import warn_deprecated
from .mysqldb import MySQLDialect_mysqldb
from ...pool import NullPool
def _is_dev_environment():
return os.environ.get("SERVER_SOFTWARE", "").startswith("Development/")
class MySQLDialect_gaerdbms(MySQLDialect_mysqldb):
@classmethod
def dbapi(cls):
warn_deprecated(
"Google Cloud SQL now recommends creating connections via the "
"MySQLdb dialect directly, using the URL format "
"mysql+mysqldb://root@/<dbname>?unix_socket=/cloudsql/"
"<projectid>:<instancename>"
)
# from django:
# http://code.google.com/p/googleappengine/source/
# browse/trunk/python/google/storage/speckle/
# python/django/backend/base.py#118
# see also [ticket:2649]
# see also http://stackoverflow.com/q/14224679/34549
from google.appengine.api import apiproxy_stub_map
if _is_dev_environment():
from google.appengine.api import rdbms_mysqldb
return rdbms_mysqldb
elif apiproxy_stub_map.apiproxy.GetStub("rdbms"):
from google.storage.speckle.python.api import rdbms_apiproxy
return rdbms_apiproxy
else:
from google.storage.speckle.python.api import rdbms_googleapi
return rdbms_googleapi
@classmethod
def get_pool_class(cls, url):
# Cloud SQL connections die at any moment
return NullPool
def create_connect_args(self, url):
opts = url.translate_connect_args()
if not _is_dev_environment():
# 'dsn' and 'instance' are because we are skipping
# the traditional google.api.rdbms wrapper
opts["dsn"] = ""
opts["instance"] = url.query["instance"]
return [], opts
def _extract_error_code(self, exception):
match = re.compile(r"^(\d+)L?:|^\((\d+)L?,").match(str(exception))
# The rdbms api will wrap then re-raise some types of errors
# making this regex return no matches.
code = match.group(1) or match.group(2) if match else None
if code:
return int(code)
dialect = MySQLDialect_gaerdbms
|