s3s: ops: track future size

        let qs = self.qs.unwrap(); // assume: qs has "Signature"

        let presigned_url = PresignedUrlV2::parse(qs).map_err(|err| invalid_request!(err, "missing presigned url v2 fields"))?;

        let method = &self.req_method;

        let uri_s3_path = extract_s3_path(self.host, self.req_uri.path(), self.base_domain)?;

        if time::OffsetDateTime::now_utc() > presigned_url.expires_time {

        let access_key = presigned_url.access_key;

        let secret_key = auth.get_secret_key(access_key).await?;

        let string_to_sign = sig_v2::create_string_to_sign(method, presigned_url.expires_str, &self.hs, &uri_s3_path, self.qs);

        let string_to_sign =

            sig_v2::create_string_to_sign(self.req_method, presigned_url.expires_str, &self.hs, &uri_s3_path, self.qs);

        let signature = sig_v2::calculate_signature(&secret_key, &string_to_sign);

        if signature != presigned_url.signature {

    }

    #[test]

    #[ignore]

    fn track_future_size() {

        macro_rules! future_size {

            ($f:path, $v:expr) => {

            future_size!(prepare,                                   1352),

            future_size!(SignatureContext::check,                   744),

            future_size!(SignatureContext::v2_check,                280),

            future_size!(SignatureContext::v2_check_presigned_url,  184),

            future_size!(SignatureContext::v2_check_presigned_url,  168),

            future_size!(SignatureContext::v2_check_header_auth,    184),

            future_size!(SignatureContext::v4_check,                720),

            future_size!(SignatureContext::v4_check_post_signature, 368),