X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=sfa%2Fstorage%2Falchemy.py;h=de2e55d9296df31de30a9cdfcdf31a803ef30759;hb=HEAD;hp=30d3e567cc5b4ded0aba73fdf9b0b19e8ac941b2;hpb=23f547bfc848537631535b1677d1409f18ef91cd;p=sfa.git

diff --git a/sfa/storage/alchemy.py b/sfa/storage/alchemy.py
index 30d3e567..de2e55d9 100644
--- a/sfa/storage/alchemy.py
+++ b/sfa/storage/alchemy.py
@@ -1,5 +1,3 @@
-from types import StringTypes
-
 from sqlalchemy import create_engine
 from sqlalchemy.orm import sessionmaker
 
@@ -11,58 +9,75 @@ from sfa.util.sfalogging import logger
 # this module is designed to be loaded when the configured db server is reachable
 # OTOH model can be loaded from anywhere including the client-side
 
+
 class Alchemy:
 
-    def __init__ (self, config):
-        dbname="sfa"
+    def __init__(self, config):
+        dbname = "sfa"
         # will be created lazily on-demand
         self._session = None
         # the former PostgreSQL.py used the psycopg2 directly and was doing
-        #self.connection.set_client_encoding("UNICODE")
+        # self.connection.set_client_encoding("UNICODE")
         # it's unclear how to achieve this in sqlalchemy, nor if it's needed at all
         # http://www.sqlalchemy.org/docs/dialects/postgresql.html#unicode
         # 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_url = "postgresql+psycopg2://%s:%s@:%s/%s"%\
-            (config.SFA_DB_USER,config.SFA_DB_PASSWORD,config.SFA_DB_PORT,dbname)
+        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_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 url in [ unix_url, tcp_url ] :
+        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 url in [unix_url, tcp_url]:
             try:
-                self.engine = create_engine (url)
+                logger.debug("Trying db URL %s" % url)
+                self.engine = create_engine(url)
                 self.check()
-                self.url=url
+                self.url = url
                 return
             except:
                 pass
-        self.engine=None
-        raise Exception,"Could not connect to database"
-                
+        self.engine = None
+        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):
-        self.engine.echo=echo
+    def debug(self, echo):
+        self.engine.echo = echo
 
-    def check (self):
-        self.engine.execute ("select 1").scalar()
+    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)
+            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):
-        if self._session is None: return
+    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
+        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()
-
+alchemy = Alchemy(Config())
+engine = alchemy.engine
+global_dbsession = alchemy.global_session()