chore: sync local updates

mengyamonitor-backend-client/latency.go

@@ -0,0 +1,78 @@
+package main
+
+import (
+	"fmt"
+	"net"
+	"strings"
+	"time"
+)
+
+// LatencyInfo 延迟信息（均由采集端在本机测量）
+type LatencyInfo struct {
+	ClientToServer float64           `json:"clientToServer"` // 采集器 → 监控中心 gRPC 地址的 TCP 建连耗时（ms），失败为 -1
+	External       map[string]string `json:"external"`       // 采集器对外站点的 TCP 建连耗时（同 checkExternalLatency）
+}
+
+// normalizeGRPCDialTarget strips common grpc-go target prefixes; expects host:port or [ipv6]:port.
+func normalizeGRPCDialTarget(addr string) string {
+	a := strings.TrimSpace(addr)
+	a = strings.TrimPrefix(a, "dns:///")
+	a = strings.TrimPrefix(a, "dns://")
+	return strings.TrimSpace(a)
+}
+
+// measureCollectorToCentralTCP returns TCP connect time in ms to the central gRPC dial target, or -1 on failure.
+func measureCollectorToCentralTCP(grpcAddr string, timeout time.Duration) float64 {
+	target := normalizeGRPCDialTarget(grpcAddr)
+	if target == "" || strings.HasPrefix(strings.ToLower(target), "unix:") {
+		return -1
+	}
+	start := time.Now()
+	conn, err := net.DialTimeout("tcp", target, timeout)
+	if err != nil {
+		return -1
+	}
+	_ = conn.Close()
+	return float64(time.Since(start).Microseconds()) / 1000.0
+}
+
+// checkExternalLatency 检测外部网站延迟
+func checkExternalLatency(host string, timeout time.Duration) string {
+	start := time.Now()
+	
+	// 尝试 TCP 连接 80 端口
+	conn, err := net.DialTimeout("tcp", host+":80", timeout)
+	if err != nil {
+		// 如果 80 端口失败，尝试 443 (HTTPS)
+		conn, err = net.DialTimeout("tcp", host+":443", timeout)
+		if err != nil {
+			return "超时"
+		}
+	}
+	defer conn.Close()
+
+	// 使用微秒换算，避免 Milliseconds() 截断成 0 ms 误导用户
+	ms := float64(time.Since(start).Microseconds()) / 1000.0
+	if ms < 1 {
+		return fmt.Sprintf("%.1f ms", ms)
+	}
+	return fmt.Sprintf("%.0f ms", ms)
+}
+
+// readExternalLatencies 读取外部网站延迟
+func readExternalLatencies() map[string]string {
+	latencies := make(map[string]string)
+	timeout := 3 * time.Second
+
+	// 检测百度
+	latencies["baidu.com"] = checkExternalLatency("baidu.com", timeout)
+
+	// 检测谷歌
+	latencies["google.com"] = checkExternalLatency("google.com", timeout)
+
+	// 检测 GitHub
+	latencies["github.com"] = checkExternalLatency("github.com", timeout)
+
+	return latencies
+}
+