    from SessionStore import SessionStore
    from SessionFileStore import SessionFileStore

    class SessionMemoryStore(SessionStore):
        """Stores the session in memory as a dictionary.

        This is fast and secure when you have one, persistent app server.

        """

        ## Init ##

        def __init__(self, app, restoreFiles=1):
            SessionStore.__init__(self, app)
            self._store = {}
            if restoreFiles == 1:
                filestore = SessionFileStore(app)
                keys = filestore.keys()
                for i in keys:
                    try:
                        self[i] = filestore[i]
                    except Exception:
                        app.handleException()
                filestore.clear()

        ## Access ##

        def __len__(self):
            return len(self._store)

        def __getitem__(self, key):
            return self._store[key]

        def __setitem__(self, key, item):
            self._store[key] = item

        def __delitem__(self, key):
            sess = self[key]
            if not sess.isExpired():
                sess.expiring()
            del self._store[key]

        def has_key(self, key):
            return self._store.has_key(key)

        def keys(self):
            return self._store.keys()

        def clear(self):
            self._store.clear()

        def setdefault(self, key, default):
            # Note, setdefault is atomic so no locking is needed.
            return self._store.setdefault(key, default)

        ## Application support ##

        def storeSession(self, session):
            pass

        def storeAllSessions(self):
            filestore = SessionFileStore(self._app)
            for i in self.keys():
                filestore[i] = self[i]