func buildRouteServiceArgs(routeServiceConfig *route_service.RouteServiceConfig, routeServiceUrl, forwardedUrlRaw string) (route_service.RouteServiceArgs, error) {
	var routeServiceArgs route_service.RouteServiceArgs
	sig, metadata, err := routeServiceConfig.GenerateSignatureAndMetadata(forwardedUrlRaw)
	if err != nil {
		return routeServiceArgs, err
	}

	routeServiceArgs.UrlString = routeServiceUrl
	routeServiceArgs.Signature = sig
	routeServiceArgs.Metadata = metadata
	routeServiceArgs.ForwardedUrlRaw = forwardedUrlRaw

	rsURL, err := url.Parse(routeServiceUrl)
	if err != nil {
		return routeServiceArgs, err
	}
	routeServiceArgs.ParsedUrl = rsURL

	return routeServiceArgs, nil
}

func (p *proxy) ServeHTTP(responseWriter http.ResponseWriter, request *http.Request) {
	startedAt := time.Now()
	accessLog := access_log.AccessLogRecord{
		Request:           request,
		StartedAt:         startedAt,
		ExtraHeadersToLog: p.ExtraHeadersToLog,
	}

	requestBodyCounter := &countingReadCloser{delegate: request.Body}
	request.Body = requestBodyCounter

	proxyWriter := NewProxyResponseWriter(responseWriter)
	handler := NewRequestHandler(request, proxyWriter, p.reporter, &accessLog)

	defer func() {
		accessLog.RequestBytesReceived = requestBodyCounter.count
		p.accessLogger.Log(accessLog)
	}()

	if !isProtocolSupported(request) {
		handler.HandleUnsupportedProtocol()
		return
	}

	if isLoadBalancerHeartbeat(request) {
		handler.HandleHeartbeat()
		return
	}

	routePool := p.lookup(request)
	if routePool == nil {
		p.reporter.CaptureBadRequest(request)
		handler.HandleMissingRoute()
		return
	}

	stickyEndpointId := p.getStickySession(request)
	iter := &wrappedIterator{
		nested: routePool.Endpoints(stickyEndpointId),

		afterNext: func(endpoint *route.Endpoint) {
			if endpoint != nil {
				handler.Logger().Set("RouteEndpoint", endpoint.ToLogData())
				accessLog.RouteEndpoint = endpoint
				p.reporter.CaptureRoutingRequest(endpoint, request)
			}
		},
	}

	if isTcpUpgrade(request) {
		handler.HandleTcpRequest(iter)
		return
	}

	if isWebSocketUpgrade(request) {
		handler.HandleWebSocketRequest(iter)
		return
	}

	backend := true

	routeServiceUrl := routePool.RouteServiceUrl()
	// Attempted to use a route service when it is not supported
	if routeServiceUrl != "" && !p.routeServiceConfig.RouteServiceEnabled() {
		handler.HandleUnsupportedRouteService()
		return
	}

	var routeServiceArgs route_service.RouteServiceArgs
	if routeServiceUrl != "" {
		rsSignature := request.Header.Get(route_service.RouteServiceSignature)
		if hasBeenToRouteService(routeServiceUrl, rsSignature) {
			// A request from a route service destined for a backend instances
			routeServiceArgs.UrlString = routeServiceUrl
			err := p.routeServiceConfig.ValidateSignature(&request.Header)
			if err != nil {
				handler.HandleBadSignature(err)
				return
			}
		} else {
			var err error

			// should not hardcode http, will be addressed by #100982038
			forwardedUrlRaw := "http" + "://" + request.Host + request.RequestURI
			routeServiceArgs, err = buildRouteServiceArgs(p.routeServiceConfig, routeServiceUrl, forwardedUrlRaw)
			backend = false
			if err != nil {
				handler.HandleRouteServiceFailure(err)
				return
			}
		}
	}

	after := func(rsp *http.Response, endpoint *route.Endpoint, err error) {
		accessLog.FirstByteAt = time.Now()
		if rsp != nil {
			accessLog.StatusCode = rsp.StatusCode
		}

		if p.traceKey != "" && request.Header.Get(router_http.VcapTraceHeader) == p.traceKey {
//.........这里部分代码省略.........