class SAEnginePlugin(plugins.SimplePlugin):
"""
SQLAlchemy integration for CherryPy
===================================
Usage:
In your application configuration:
[sqlalchemy]
engine.url = "postgresql+psycopg2://user:password@host/db"
engine.echo = False
engine.echo_pool = False
engine.pool_size = 5
engine.pool_timeout = 30
engine.pool_recycle = -1
engine.max_overflow = 10
engine.convert_unicode = False
metadata.reflect = False
metadata.schema = None
metadata.quote_schema = None
session.autocommit = False
session.autoflush = True
In your code:
SAEnginePlugin(cherrypy.engine, app.config['sqlalchemy'], myengine,
mysession, mymeta).subscribe()
"""
def __init__(self, bus, config, engine=None, session=None, meta=None):
super(SAEnginePlugin, self).__init__(bus)
self.sa_engine = engine
self.sa_meta = meta
self.sa_session = session
self.config = config
self.bus.subscribe('get-session', self.get_session)
self.bus.subscribe('release-session', self.release_session)
def start(self):
self.bus.log('SAEnginePlugin: Starting up DB access')
_config = {}
for (k, v) in self.config.iteritems():
_partition = k.partition('.')
_config.setdefault(_partition[0], {})[_partition[2]] = v
# Engine
if not self.sa_engine:
url = _config['engine'].pop('url')
pool_factory = _config['engine'].pop('poolclass', None)
if pool_factory:
poolclass = getattr(sqlalchemy.pool, pool_factory)
_config['engine']['poolclass'] = poolclass
self.sa_engine = create_engine(url, **_config['engine'])
# Metadata
if not self.sa_meta:
self.sa_meta = MetaData(bind=self.sa_engine,
**_config.get('metadata', {}))
elif not self.sa_meta.is_bound():
self.sa_meta.bind = self.sa_engine
if _config.get('metadata', {}).get('reflect'):
self.sa_meta.reflect()
# Session
if not self.sa_session:
_session = sessionmaker(**_config.get('session', {}))
self.sa_session = scoped_session(_session)
self.sa_session.configure(bind=self.sa_engine)
def stop(self):
self.bus.log('SAEnginePlugin: Stopping down DB access')
self.bus.unsubscribe('get-session', self.get_session)
if self.sa_engine:
self.sa_engine.dispose()
self.sa_engine = None
def get_session(self):
return self.sa_session()
def release_session(self):
self.sa_session.remove()
