[OPTI] improved SQLAlchemy sessions management

(using `scoped_session`, removed unnecessary use of Aldjemy)

gargantext/models/users.py

@@ -22,10 +22,8 @@ class User(Base):
     is_active = Column(Boolean())
     date_joined = DateTime(timezone=False)
 
-    def get_contacts(self, session=None):
+    def get_contacts(self):
         """get all contacts in relation with the user"""
-        if session is None:
-            session = Session()
         Friend = aliased(User)
         query = (session
             .query(Friend)
@@ -34,11 +32,9 @@ class User(Base):
         )
         return query.all()
 
-    def get_nodes(self, session=None, nodetype=None):
+    def get_nodes(self, nodetype=None):
         """get all nodes belonging to the user"""
         from .nodes import Node
-        if session is None:
-            session = Session()
         query = (session
             .query(Node)
             .filter(Node.user_id == self.id)

gargantext/util/db.py

-from aldjemy.core import get_engine
 from gargantext import settings
 
 
 # get engine, session, etc.
 
-from sqlalchemy.orm import sessionmaker
+from sqlalchemy.orm import sessionmaker, scoped_session
 from sqlalchemy.ext.declarative import declarative_base
 
 def get_engine():
@@ -18,7 +17,7 @@ engine = get_engine()
 
 Base = declarative_base()
 
-Session = sessionmaker(bind=engine)
+session = scoped_session(sessionmaker(bind=engine))
 
 
 # tools to build models

gargantext/util/db_cache.py

@@ -12,7 +12,6 @@ from gargantext import models
 class ModelCache(dict):
 
     def __init__(self, model, preload=False):
-        self._session = Session()
         self._model = model
         self._columns = [column for column in model.__table__.columns if column.unique or column.primary_key]
         self._columns_names = [column.name for column in self._columns]
@@ -20,7 +19,7 @@ class ModelCache(dict):
             self.preload()
 
     def __del__(self):
-        self._session.close()
+        session.close()
 
     def __missing__(self, key):
         formatted_key = None
@@ -34,7 +33,7 @@ class ModelCache(dict):
         if formatted_key in self:
             self[key] = self[formatted_key]
         else:
-            element = self._session.query(self._model).filter(or_(*conditions)).first()
+            element = session.query(self._model).filter(or_(*conditions)).first()
             if element is None:
                 raise KeyError
             self[key] = element
@@ -42,7 +41,7 @@ class ModelCache(dict):
 
     def preload(self):
         self.clear()
-        for element in self._session.query(self._model).all():
+        for element in session.query(self._model).all():
             for column_name in self._columns_names:
                 key = getattr(element, column_name)
                 self[key] = element

gargantext/views/pages/projects.py

@@ -13,7 +13,6 @@ def overview(request):
     To each project, we can link a resource that can be an image.
     '''
 
-    session = Session()
     user = cache.User[request.user.username]
     project_type = cache.NodeType['Project']
 
@@ -30,10 +29,10 @@ def overview(request):
             session.commit()
 
     # list of projects created by the logged user
-    user_projects = user.get_nodes(session=session, nodetype=project_type)
+    user_projects = user.get_nodes(nodetype=project_type)
 
     # list of contacts of the logged user
-    contacts = user.get_contacts(session=session)
+    contacts = user.get_contacts()
     contacts_projects = []
     for contact in contacts:
         contact_projects = (session

requirements.txt

-Django==1.6.11
+Django==1.9.2
 RandomWords==0.1.12
+SQLAlchemy==1.0.11
 django-pgfields==1.4.4
 django-pgjsonb==0.0.16
 psycopg2==2.6.1