1 files changed, 82 insertions, 0 deletions
diff --git a/appengine_django/sessions/backends/db.py b/appengine_django/sessions/backends/db.py
new file mode 100644
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+++ b/appengine_django/sessions/backends/db.py
@@ -0,0 +1,82 @@
+#!/usr/bin/python2.4
+#
+# Copyright 2008 Google Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#  http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from datetime import datetime
+
+from django.contrib.sessions.backends import base
+from django.core.exceptions import SuspiciousOperation
+
+from appengine_django.sessions.models import Session
+
+
+class SessionStore(base.SessionBase):
+  """A key-based session store for Google App Engine."""
+
+  def load(self):
+    session = self._get_session(self.session_key)
+    if session:
+      try:
+        return self.decode(session.session_data)
+      except SuspiciousOperation:
+        # Create a new session_key for extra security.
+        pass
+    self.session_key = self._get_new_session_key()
+    self._session_cache = {}
+    self.save()
+    # Ensure the user is notified via a new cookie.
+    self.modified = True
+    return {}
+
+  def save(self, must_create=False):
+    if must_create and self.exists(self.session_key):
+      raise base.CreateError
+    session = Session(
+        key_name='k:' + self.session_key,
+        session_data = self.encode(self._session),
+        expire_date = self.get_expiry_date())
+    session.put()
+
+  def exists(self, session_key):
+    return Session.get_by_key_name('k:' + session_key) is not None
+
+  def delete(self, session_key=None):
+    if session_key is None:
+      session_key = self._session_key
+    session = self._get_session(session_key=session_key)
+    if session:
+      session.delete()
+
+  def _get_session(self, session_key):
+    session = Session.get_by_key_name('k:' + session_key)
+    if session:
+      if session.expire_date > datetime.now():
+        return session
+      session.delete()
+    return None
+
+  def create(self):
+    while True:
+      self.session_key = self._get_new_session_key()
+      try:
+        # Save immediately to ensure we have a unique entry in the
+        # database.
+        self.save(must_create=True)
+      except base.CreateError:
+        # Key wasn't unique. Try again.
+        continue
+      self.modified = True
+      self._session_cache = {}
+      return