Return a key for the current request url.

        :return: The storage key for the current url
        :rettype: string

def get_key_from_request(self):
        '''Return a key for the current request url.

        :return: The storage key for the current url
        :rettype: string
        '''

        path = "result:%s" % self.context.request.url

        if self.is_auto_webp():
            path += '/webp'

        return path