Function runSpeedTestSimple

main.go:349–412

runSpeedTestSimple 简单速度测试，返回 (峰值速度 kB/s, TCP延迟ms, 三字码头)

(ip string, port int, useTLS bool)

// runSpeedTestSimple 简单速度测试，返回 (峰值速度 kB/s, TCP延迟ms, 三字码头)
func runSpeedTestSimple(ip string, port int, useTLS bool) (int, int, string) {
	var tcpMs int
	transport := &http.Transport{
		DialContext: func(ctx context.Context, network, addr string) (net.Conn, error) {
			start := time.Now()
			conn, err := net.Dial("tcp", net.JoinHostPort(ip, strconv.Itoa(port)))
			if err == nil {
				tcpMs = int(time.Since(start).Milliseconds())
			}
			return conn, err
		},
	}
	if useTLS {
		transport.TLSClientConfig = &tls.Config{ServerName: speedTestDomain}
	}
	client := &http.Client{
		Transport: transport,
		Timeout:   5 * time.Second,
	}

	scheme := "http"
	if useTLS {
		scheme = "https"
	}
	testURL := fmt.Sprintf("%s://%s/%s", scheme, speedTestDomain, speedTestFile)

	resp, err := client.Get(testURL)
	if err != nil {
		return 0, 0, ""
	}
	defer resp.Body.Close()

	cfRay := resp.Header.Get("CF-RAY")
	dataCenter := extractDataCenter(cfRay)

	buf := make([]byte, 32*1024)
	var totalBytes int64
	var windowBytes int64
	windowStart := time.Now()
	maxSpeed := 0

	for {
		n, err := resp.Body.Read(buf)
		totalBytes += int64(n)
		windowBytes += int64(n)
		if err != nil {
			break
		}

		elapsed := time.Since(windowStart).Seconds()
		if elapsed >= 1.0 {
			speedKB := int(float64(windowBytes) / 1024 / elapsed)
			if speedKB > maxSpeed {
				maxSpeed = speedKB
			}
			windowBytes = 0
			windowStart = time.Now()
		}