Function NewProtocolSelector

connection/protocol.go:223–260

(
	protocolFlag string,
	accountTag string,
	tunnelTokenProvided bool,
	protocolFetcher edgediscovery.PercentageFetcher,
	resolveTTL time.Duration,
	log *zerolog.Logger,
)

}

func NewProtocolSelector(
	protocolFlag string,
	accountTag string,
	tunnelTokenProvided bool,
	protocolFetcher edgediscovery.PercentageFetcher,
	resolveTTL time.Duration,
	log *zerolog.Logger,
) (ProtocolSelector, error) {
	threshold := switchThreshold(accountTag)
	fetchedProtocol, err := getProtocol(ProtocolList, protocolFetcher, threshold)
	log.Debug().Msgf("Fetched protocol: %s", fetchedProtocol)
	if err != nil {
		log.Warn().Msg("Unable to lookup protocol percentage.")
		// Falling through here since 'auto' is handled in the switch and failing
		// to do the protocol lookup isn't a failure since it can be triggered again
		// after the TTL.
	}

	// If the user picks a protocol, then we stick to it no matter what.
	switch protocolFlag {
	case "h2mux":
		// Any users still requesting h2mux will be upgraded to http2 instead
		log.Warn().Msg("h2mux is no longer a supported protocol: upgrading edge connection to http2. Please remove '--protocol h2mux' from runtime arguments to remove this warning.")
		return &staticProtocolSelector{current: HTTP2}, nil
	case QUIC.String():
		return &staticProtocolSelector{current: QUIC}, nil
	case HTTP2.String():
		return &staticProtocolSelector{current: HTTP2}, nil
	case AutoSelectFlag:
		// When a --token is provided, we want to start with QUIC but have fallback to HTTP2
		if tunnelTokenProvided {
			return newDefaultProtocolSelector(QUIC), nil
		}
		return newRemoteProtocolSelector(fetchedProtocol, ProtocolList, threshold, protocolFetcher, resolveTTL, log), nil
	}

	return nil, fmt.Errorf("unknown protocol %s, %s", protocolFlag, AvailableProtocolFlagMessage)
}

func switchThreshold(accountTag string) int32 {
	h := fnv.New32a()