refactor: 优化指标统计逻辑，减少锁的使用，提高性能

internal/middleware/metrics.go

@@ -1,127 +1,23 @@
 package middleware
 
 import (
-	"sync/atomic"
 	"time"
 
 	"github.com/gin-gonic/gin"
+
+	"anyproxy/internal/metrics"
 )
 
-// 简易 QPS / QPM 统计：使用滑动窗口环形数组按秒/按分钟聚合
-// secondBuckets: 最近 60 秒每秒的请求计数
-// minuteBuckets: 最近 60 分钟每分钟的请求计数
-
-var (
-	secondBuckets [60]atomic.Int64
-	minuteBuckets [60]atomic.Int64
-	lastSecond int64
-	lastMinute int64
-	// 总请求数 (复用可选)
-	totalRequests atomic.Int64
-)
-
-func init() {
-	now := time.Now()
-	lastSecond = now.Unix()
-	lastMinute = now.Unix() / 60
-}
-
-// AddRequest 在收到一个请求时调用，通常在请求完成后计数
-func AddRequest() {
-	now := time.Now()
-	sec := now.Unix()
-	min := sec / 60
-
-	// 处理秒级 bucket
-	oldSec := atomic.LoadInt64(&lastSecond)
-	if sec != oldSec {
-		// 跨秒：清理可能跨越多个秒的间隙
-		if atomic.CompareAndSwapInt64(&lastSecond, oldSec, sec) {
-			steps := int(sec - oldSec)
-			if steps > 60 { steps = 60 }
-			for i := 1; i <= steps; i++ {
-				idx := int((oldSec+int64(i)) % 60)
-				secondBuckets[idx].Store(0)
-			}
-		}
-	}
-	secIdx := int(sec % 60)
-	secondBuckets[secIdx].Add(1)
-
-	// 处理分钟级 bucket
-	oldMin := atomic.LoadInt64(&lastMinute)
-	if min != oldMin {
-		if atomic.CompareAndSwapInt64(&lastMinute, oldMin, min) {
-			steps := int(min - oldMin)
-			if steps > 60 { steps = 60 }
-			for i := 1; i <= steps; i++ {
-				idx := int((oldMin+int64(i)) % 60)
-				minuteBuckets[idx].Store(0)
-			}
-		}
-	}
-	minIdx := int(min % 60)
-	minuteBuckets[minIdx].Add(1)
-
-	totalRequests.Add(1)
-}
-
-// CurrentQPS 返回最近 1 秒（当前秒）的请求数
-func CurrentQPS() int64 {
-	sec := time.Now().Unix()
-	if sec != atomic.LoadInt64(&lastSecond) { return 0 }
-	return secondBuckets[sec%60].Load()
-}
-
-// AvgQPSRecent60 返回最近 60 秒平均 QPS
-func AvgQPSRecent60() float64 {
-	sec := time.Now().Unix()
-	total := int64(0)
-	last := atomic.LoadInt64(&lastSecond)
-	for i := 0; i < 60; i++ {
-		// 只统计在窗口内(未被清零)的 bucket
-		bucketSec := sec - int64(i)
-		if bucketSec <= last && last-bucketSec < 60 {
-			idx := bucketSec % 60
-			total += secondBuckets[idx].Load()
-		}
-	}
-	return float64(total) / 60.0
-}
-
-// CurrentQPM 返回当前分钟的请求数
-func CurrentQPM() int64 {
-	min := time.Now().Unix() / 60
-	if min != atomic.LoadInt64(&lastMinute) { return 0 }
-	return minuteBuckets[min%60].Load()
-}
-
-// AvgQPMRecent60 返回最近 60 分钟的平均 QPM
-func AvgQPMRecent60() float64 {
-	min := time.Now().Unix() / 60
-	total := int64(0)
-	last := atomic.LoadInt64(&lastMinute)
-	for i := 0; i < 60; i++ {
-		bucketMin := min - int64(i)
-		if bucketMin <= last && last-bucketMin < 60 {
-			idx := bucketMin % 60
-			total += minuteBuckets[idx].Load()
-		}
-	}
-	return float64(total) / 60.0
-}
-
-// TotalRequests 返回总请求量（从进程启动以来）
-func TotalRequests() int64 { return totalRequests.Load() }
-
 // MetricsHandler 输出当前指标
 func MetricsHandler(c *gin.Context) {
+	qps := metrics.QPS()
+	qpm := metrics.QPM()
 	c.JSON(200, gin.H{
-		"qps_current": CurrentQPS(),
-		"qps_avg_60s": AvgQPSRecent60(),
-		"qpm_current": CurrentQPM(),
-		"qpm_avg_60m": AvgQPMRecent60(),
-		"total":       TotalRequests(),
+		"qps_current": qps,
+		"qps_avg_60s": float64(qpm) / 60.0,
+		"qpm_current": qpm,
+		"qpm_avg_60m": float64(qpm),
+		"total":       metrics.Total(),
 		"timestamp":   time.Now().Unix(),
 	})
 }