1 from django.conf import settings

     2 from django.contrib.sessions.models import Session

     3 from django.contrib.sessions.backends.base import SessionBase

     4 from django.core.exceptions import SuspiciousOperation

     5 import datetime

     6 

     7 class SessionStore(SessionBase):

     8     """

     9     Implements database session store

    10     """

    11     def __init__(self, session_key=None):

    12         super(SessionStore, self).__init__(session_key)

    13 

    14     def load(self):

    15         try:

    16             s = Session.objects.get(

    17                 session_key = self.session_key,

    18                 expire_date__gt=datetime.datetime.now()

    19             )

    20             return self.decode(s.session_data)

    21         except (Session.DoesNotExist, SuspiciousOperation):

    22 

    23             # Create a new session_key for extra security.

    24             self.session_key = self._get_new_session_key()

    25             self._session_cache = {}

    26 

    27             # Save immediately to minimize collision

    28             self.save()

    29             # Ensure the user is notified via a new cookie.

    30             self.modified = True

    31             return {}

    32 

    33     def exists(self, session_key):

    34         try:

    35             Session.objects.get(session_key=session_key)

    36         except Session.DoesNotExist:

    37             return False

    38         return True

    39 

    40     def save(self):

    41         Session.objects.create(

    42             session_key = self.session_key,

    43             session_data = self.encode(self._session),

    44             expire_date = datetime.datetime.now() + datetime.timedelta(seconds=settings.SESSION_COOKIE_AGE)

    45         )

    46 

    47     def delete(self, session_key):

    48         try:

    49             Session.objects.get(session_key=session_key).delete()

    50         except Session.DoesNotExist:

    51             pass