:param key:

        """

        log.debug('marking %s for invalidation' % key)

        inv_obj = Session.query(cls)\

            .filter(cls.cache_key == key).scalar()

        if inv_obj:

            inv_obj.cache_active = False

        else:

            log.debug('cache key not found in invalidation db -> creating one')

            inv_obj = CacheInvalidation(key)

        try:

            Session.add(inv_obj)

            Session.commit()

        except Exception:

            log.error(traceback.format_exc())

            Session.rollback()

    @classmethod

    def set_valid(cls, key):

        """

        Mark this cache key as active and currently cached

        :param key:

        """

        inv_obj = CacheInvalidation.query()\

            .filter(CacheInvalidation.cache_key == key).scalar()

        inv_obj.cache_active = True

        Session.add(inv_obj)

        Session.commit()

class ChangesetComment(Base, BaseModel):

    __tablename__ = 'changeset_comments'

    __table_args__ = ({'extend_existing':True},)

    comment_id = Column('comment_id', Integer(), nullable=False, primary_key=True)

    repo_id = Column('repo_id', Integer(), ForeignKey('repositories.repo_id'), nullable=False)

    revision = Column('revision', String(40), nullable=False)

    line_no = Column('line_no', Unicode(10), nullable=True)

    f_path = Column('f_path', Unicode(1000), nullable=True)

    user_id = Column('user_id', Integer(), ForeignKey('users.user_id'), nullable=False)

    text = Column('text', Unicode(25000), nullable=False)

    modified_at = Column('modified_at', DateTime(), nullable=False, default=datetime.datetime.now)

    author = relationship('User', lazy='joined')

    repo = relationship('Repository')

    @classmethod

    def get_users(cls, revision):

        """

        Returns user associated with this changesetComment. ie those

        who actually commented

        :param cls:

        :param revision:

        """

        return Session.query(User)\

                .filter(cls.revision == revision)\

                .join(ChangesetComment.author).all()

class Notification(Base, BaseModel):

    __tablename__ = 'notifications'

    TYPE_CHANGESET_COMMENT = u'cs_comment'

    TYPE_MESSAGE = u'message'

    TYPE_MENTION = u'mention'

    TYPE_REGISTRATION = u'registration'

    notification_id = Column('notification_id', Integer(), nullable=False, primary_key=True)

    subject = Column('subject', Unicode(512), nullable=True)

    body = Column('body', Unicode(50000), nullable=True)

    created_by = Column("created_by", Integer(), ForeignKey('users.user_id'), nullable=True)

    created_on = Column('created_on', DateTime(timezone=False), nullable=False, default=datetime.datetime.now)

    type_ = Column('type', Unicode(256))

    created_by_user = relationship('User')

    notifications_to_users = relationship('UserNotification', lazy='joined',

                                          cascade="all, delete, delete-orphan")

    @property

    def recipients(self):

        return [x.user for x in UserNotification.query()\

                .filter(UserNotification.notification == self).all()]

    @classmethod

    def create(cls, created_by, subject, body, recipients, type_=None):

        if type_ is None:

            type_ = Notification.TYPE_MESSAGE

        notification = cls()

        notification.created_by_user = created_by

        notification.subject = subject

        notification.body = body

        notification.type_ = type_

        notification.created_on = datetime.datetime.now()

        for u in recipients:

            assoc = UserNotification()

            assoc.notification = notification

            u.notifications.append(assoc)

        Session.add(notification)

        return notification

    @property

    def description(self):

        from rhodecode.model.notification import NotificationModel

        return NotificationModel().make_description(self)

class UserNotification(Base, BaseModel):