2to3 -f raise

[sfa.git] / sfa / storage / alchemy.py

diff --git a/sfa/storage/alchemy.py b/sfa/storage/alchemy.py
index 7e00116..fb8dfac 100644 (file)
--- a/sfa/storage/alchemy.py
+++ b/sfa/storage/alchemy.py
@@ -4,7 +4,6 @@ from sqlalchemy import create_engine
 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
@@ -15,7 +14,7 @@ from sfa.util.sfalogging import logger
 class Alchemy:
 
     def __init__ (self, config):
-        dbname="sfa"
+        dbname = "sfa"
         # will be created lazily on-demand
         self._session = None
         # the former PostgreSQL.py used the psycopg2 directly and was doing
@@ -32,6 +31,7 @@ class Alchemy:
             (config.SFA_DB_USER,config.SFA_DB_PASSWORD,config.SFA_DB_HOST,config.SFA_DB_PORT,dbname)
         for url in [ unix_url, tcp_url ] :
             try:
+                logger.debug("Trying db URL %s"%url)
                 self.engine = create_engine (url)
                 self.check()
                 self.url=url
@@ -39,8 +39,8 @@ class Alchemy:
             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):
@@ -49,21 +49,34 @@ class Alchemy:
     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.debug('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.debug('alchemy.close_global_session %s'%self._session)
         self._session.close()
         self._session=None
 
+    # create a dbsession to be managed separately
+    def session (self):
+        Session=sessionmaker()
+        session=Session (bind=self.engine)
+        logger.debug('alchemy.session created session %s'%session)
+        return session
+
+    def close_session (self, session):
+        logger.debug('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()