feat(metrics): initialize cache and object pool in metrics collector

- Added cache initialization to enhance performance and data retrieval efficiency.
- Introduced an object pool for managing statistics, optimizing memory usage during metrics processing.
- Improved code organization by clarifying initialization steps for cache and monitoring components.

These changes enhance the metrics collector's efficiency and resource management, ensuring better performance in data handling.

internal/metrics/collector.go

@@ -71,6 +71,9 @@ func InitCollector(dbPath string, config *config.Config) error {
 		db:             db,
 	}
 
+	// 先初始化 cache
+	globalCollector.cache = cache.NewCache(constants.CacheTTL)
+
 	// 在初始化时设置最后保存时间
 	lastSaveTime = time.Now()
 
@@ -93,7 +96,7 @@ func InitCollector(dbPath string, config *config.Config) error {
 			lastMetrics.TotalRequests, lastMetrics.TotalErrors, lastMetrics.TotalBytes)
 	}
 
-	globalCollector.cache = cache.NewCache(constants.CacheTTL)
+	// 初始化监控器
 	globalCollector.monitor = monitor.NewMonitor(globalCollector)
 
 	// 如果配置了飞书webhook，则启用飞书告警
@@ -104,6 +107,13 @@ func InitCollector(dbPath string, config *config.Config) error {
 		log.Printf("Feishu alert enabled")
 	}
 
+	// 初始化对象池
+	globalCollector.statsPool = sync.Pool{
+		New: func() interface{} {
+			return make(map[string]interface{}, 20)
+		},
+	}
+
 	// 启动定时保存
 	go func() {
 		time.Sleep(time.Duration(rand.Int63n(60)) * time.Second)
@@ -163,12 +173,6 @@ func InitCollector(dbPath string, config *config.Config) error {
 		log.Println("Database closed successfully")
 	})
 
-	globalCollector.statsPool = sync.Pool{
-		New: func() interface{} {
-			return make(map[string]interface{}, 20)
-		},
-	}
-
 	return nil
 }