fix(metrics): 优化延迟统计和分布数据处理

- 修复延迟统计分布数据获取逻辑，增加更健壮的类型转换
- 确保延迟分布桶始终存在，即使没有数据
- 在处理器中为空分布数据添加默认初始化
- 优化指标收集器中的延迟桶初始化和数据获取方法

internal/handler/metrics.go

@@ -161,14 +161,31 @@ func (h *ProxyHandler) MetricsHandler(w http.ResponseWriter, r *http.Request) {
 	metrics.LatencyStats.Max = utils.SafeString(latencyStats["max"], "0ms")
 
 	// 处理分布数据
-	if distribution, ok := latencyStats["distribution"].(map[string]interface{}); ok {
+	if stats["latency_stats"] != nil {
+		if distribution, ok := stats["latency_stats"].(map[string]interface{})["distribution"]; ok && distribution != nil {
+			if distributionMap, ok := distribution.(map[string]interface{}); ok {
 				metrics.LatencyStats.Distribution = make(map[string]int64)
-		for k, v := range distribution {
+				for k, v := range distributionMap {
 					if intValue, ok := v.(float64); ok {
 						metrics.LatencyStats.Distribution[k] = int64(intValue)
+					} else if intValue, ok := v.(int64); ok {
+						metrics.LatencyStats.Distribution[k] = intValue
 					}
 				}
 			}
+		}
+	}
+
+	// 如果分布数据为空，初始化一个空的分布
+	if metrics.LatencyStats.Distribution == nil {
+		metrics.LatencyStats.Distribution = make(map[string]int64)
+		// 添加默认的延迟桶
+		metrics.LatencyStats.Distribution["<10ms"] = 0
+		metrics.LatencyStats.Distribution["10-50ms"] = 0
+		metrics.LatencyStats.Distribution["50-200ms"] = 0
+		metrics.LatencyStats.Distribution["200-1000ms"] = 0
+		metrics.LatencyStats.Distribution[">1s"] = 0
+	}
 
 	// 填充错误统计数据
 	metrics.ErrorStats.ClientErrors = clientErrors

internal/metrics/collector.go

@@ -61,11 +61,12 @@ func InitCollector(cfg *config.Config) error {
 		instance.bandwidthStats.history = make(map[string]int64)
 
 		// 初始化延迟分布桶
-		instance.latencyBuckets.Store("<10ms", new(int64))
+		buckets := []string{"<10ms", "10-50ms", "50-200ms", "200-1000ms", ">1s"}
-		instance.latencyBuckets.Store("10-50ms", new(int64))
+		for _, bucket := range buckets {
-		instance.latencyBuckets.Store("50-200ms", new(int64))
+			counter := new(int64)
-		instance.latencyBuckets.Store("200-1000ms", new(int64))
+			*counter = 0
-		instance.latencyBuckets.Store(">1s", new(int64))
+			instance.latencyBuckets.Store(bucket, counter)
+		}
 
 		// 启动数据一致性检查器
 		instance.startConsistencyChecker()
@@ -344,14 +345,20 @@ func (c *Collector) GetStats() map[string]interface{} {
 
 	// 收集延迟分布
 	latencyDistribution := make(map[string]int64)
-	c.latencyBuckets.Range(func(key, value interface{}) bool {
+
-		if counter, ok := value.(*int64); ok {
+	// 确保所有桶都存在，即使计数为0
-			latencyDistribution[key.(string)] = atomic.LoadInt64(counter)
+	buckets := []string{"<10ms", "10-50ms", "50-200ms", "200-1000ms", ">1s"}
+	for _, bucket := range buckets {
+		if counter, ok := c.latencyBuckets.Load(bucket); ok {
+			if counter != nil {
+				latencyDistribution[bucket] = atomic.LoadInt64(counter.(*int64))
 			} else {
-			latencyDistribution[key.(string)] = value.(int64)
+				latencyDistribution[bucket] = 0
+			}
+		} else {
+			latencyDistribution[bucket] = 0
+		}
 	}
-		return true
-	})
 
 	// 获取最近请求记录（使用读锁）
 	recentRequests := c.recentRequests.GetAll()