fn check()

in neqo-http3/src/settings.rs [252:296]
41 lines of code
9 McCabe index (conditional complexity)

    fn check(&self, token: &[u8]) -> ZeroRttCheckResult {
        let mut dec = Decoder::from(token);

        // Read and check the version.
        if let Some(version) = dec.decode_varint() {
            if version != SETTINGS_ZERO_RTT_VERSION {
                return ZeroRttCheckResult::Reject;
            }
        } else {
            return ZeroRttCheckResult::Fail;
        }

        // Now treat the rest as a settings frame.
        let mut settings = HSettings::new(&[]);
        if settings.decode_frame_contents(&mut dec).is_err() {
            return ZeroRttCheckResult::Fail;
        }
        if settings.iter().all(|setting| match setting.setting_type {
            HSettingType::BlockedStreams => {
                u64::from(self.settings.get_max_blocked_streams()) >= setting.value
            }
            HSettingType::MaxTableCapacity => {
                self.settings.get_max_table_size_decoder() >= setting.value
            }
            HSettingType::EnableWebTransport => {
                if setting.value > 1 {
                    return false;
                }
                let value = setting.value == 1;
                self.settings.get_webtransport() || !value
            }
            HSettingType::EnableH3Datagram => {
                if setting.value > 1 {
                    return false;
                }
                let value = setting.value == 1;
                self.settings.get_http3_datagram() || !value
            }
            HSettingType::MaxHeaderListSize => true,
        }) {
            ZeroRttCheckResult::Accept
        } else {
            ZeroRttCheckResult::Reject
        }
    }