auth.py 文件源码

def get_auth(factory=Auth, key=_auth_registry_key, request=None):
    """Returns an instance of :class:`Auth` from the request registry.

    It'll try to get it from the current request registry, and if it is not
    registered it'll be instantiated and registered. A second call to this
    function will return the same instance.

    :param factory:
        The callable used to build and register the instance if it is not yet
        registered. The default is the class :class:`Auth` itself.
    :param key:
        The key used to store the instance in the registry. A default is used
        if it is not set.
    :param request:
        A :class:`webapp2.Request` instance used to store the instance. The
        active request is used if it is not set.
    """
    request = request or webapp2.get_request()
    auth = request.registry.get(key)
    if not auth:
        auth = request.registry[key] = factory(request)

    return auth