from sqlalchemy.orm import sessionmaker
from sqlalchemy import Column, Integer, String
-from sqlalchemy.orm import relationship, backref
from sqlalchemy import ForeignKey
from sfa.util.sfalogging import logger
# this module is designed to be loaded when the configured db server is reachable
-# OTOH persistentobjs can be loaded from anywhere including the client-side
+# OTOH model can be loaded from anywhere including the client-side
class Alchemy:
# we indeed have /var/lib/pgsql/data/postgresql.conf where
# this setting is unset, it might be an angle to tweak that if need be
# try a unix socket first - omitting the hostname does the trick
- unix_desc = "postgresql+psycopg2://%s:%s@:%s/%s"%\
+ unix_url = "postgresql+psycopg2://%s:%s@:%s/%s"%\
(config.SFA_DB_USER,config.SFA_DB_PASSWORD,config.SFA_DB_PORT,dbname)
# the TCP fallback method
- tcp_desc = "postgresql+psycopg2://%s:%s@%s:%s/%s"%\
+ tcp_url = "postgresql+psycopg2://%s:%s@%s:%s/%s"%\
(config.SFA_DB_USER,config.SFA_DB_PASSWORD,config.SFA_DB_HOST,config.SFA_DB_PORT,dbname)
- for engine_desc in [ unix_desc, tcp_desc ] :
+ for url in [ unix_url, tcp_url ] :
try:
- self.engine = create_engine (engine_desc)
+ logger.debug("Trying db URL %s"%url)
+ self.engine = create_engine (url)
self.check()
+ self.url=url
return
except:
pass
self.engine=None
- raise Exception,"Could not connect to database"
-
+ raise Exception,"Could not connect to database %s as %s with psycopg2"%(dbname,config.SFA_DB_USER)
+
# expects boolean True: debug is ON or False: debug is OFF
def debug (self, echo):
def check (self):
self.engine.execute ("select 1").scalar()
- def session (self):
+ def global_session (self):
if self._session is None:
Session=sessionmaker ()
self._session=Session(bind=self.engine)
+ logger.info('alchemy.global_session created session %s'%self._session)
return self._session
- def close_session (self):
+ def close_global_session (self):
if self._session is None: return
+ logger.info('alchemy.close_global_session %s'%self._session)
self._session.close()
self._session=None
- def commit (self):
- self.session().commit()
-
- def insert (self, stuff, commit=False):
- if isinstance (stuff,list):
- self.session().add_all(stuff)
- else:
- self.session().add(obj)
-
- # for compat with the previous PostgreSQL stuff
- def update (self, record):
- self.commit()
+ # create a dbsession to be managed separately
+ def session (self):
+ Session=sessionmaker()
+ session=Session (bind=self.engine)
+ logger.info('alchemy.session created session %s'%session)
+ return session
- def remove (self, record):
- self.delete(record)
- self.commit()
+ def close_session (self, session):
+ logger.info('alchemy.close_session closed session %s'%session)
+ session.close()
####################
from sfa.util.config import Config
alchemy=Alchemy (Config())
engine=alchemy.engine
-dbsession=alchemy.session()
+global_dbsession=alchemy.global_session()