perf(exporter): 优化分片数据统计实现并发查询

- 引入sync包实现并发控制
- 使用信号量限制最大并发数为10
- 针对每个时间范围启动goroutine并行执行查询
- 利用互斥锁保护total计数的安全更新
- 等待所有并发查询完成后返回总计数结果

server/internal/exporter/stream.go

@@ -7,6 +7,7 @@ import (
 	"server/internal/schema"
 	"server/internal/utils"
 	"strings"
+	"sync"
 	"time"
 )
 
@@ -228,15 +229,32 @@ func CountRowsFastChunked(db *sql.DB, ds, main string, filters map[string]interf
 		})
 	}
 
+	// 并行查询所有分片，最多10个并发
 	var total int64
+	var mu sync.Mutex
+	var wg sync.WaitGroup
+	semaphore := make(chan struct{}, 10) // 控制最多10个并发查询
+
 	for _, rg := range ranges {
+		wg.Add(1)
+		go func(rangeVal [2]string) {
+			defer wg.Done()
+			semaphore <- struct{}{}        // 获取信号量
+			defer func() { <-semaphore }() // 释放信号量
+
 			fl := map[string]interface{}{}
 			for k, v := range filters {
 				fl[k] = v
 			}
-		fl["create_time_between"] = []string{rg[0], rg[1]}
+			fl["create_time_between"] = []string{rangeVal[0], rangeVal[1]}
-		total += CountRowsFast(db, ds, main, fl)
+			count := CountRowsFast(db, ds, main, fl)
+
+			mu.Lock()
+			total += count
+			mu.Unlock()
+		}(rg)
 	}
+	wg.Wait()
 	return total
 }