fix(backend): adjust view count decrement logic in VaildateShare to prevent multiple decrements during concurrent downloads

backend/internal/controllers/download.go

@@ -42,14 +42,8 @@ func DownloadShare(c echo.Context) error {
 		if err != nil {
 			return err
 		}
-		models.SetRedisShareInfo(claims.ShareId, models.RedisShareInfo{
-			ViewNum: shareInfo.ViewNum - 1,
-		})
 		return cc.Attachment(fmt.Sprintf("%s/%s", uploadPath, utils.GetFileId(fileInfo.FileHash, fileInfo.FileSize)), shareInfo.FileName)
 	}
-	models.SetRedisShareInfo(claims.ShareId, models.RedisShareInfo{
-		ViewNum: shareInfo.ViewNum - 1,
-	})
 	return utils.HTTPSuccessHandler(c, map[string]any{
 		"data": shareInfo.Data,
 	})
@@ -105,6 +99,17 @@ func VaildateShare(c echo.Context) error {
 		if fileInfo.FileType != models.FileTypeUpload {
 			return utils.HTTPErrorHandler(c, errors.New("分享文件状态错误"))
 		}
+	}
+	// download_nums 必须放在创建token的时候减掉，不然多线程下载会导致多次减掉
+	latestViewNum := shareInfo.ViewNum - 1
+	// 如果下载次数为0，则设置为-1 防止空值问题
+	if latestViewNum < 1 {
+		latestViewNum = -1
+	}
+	models.SetRedisShareInfo(r.ShareId, models.RedisShareInfo{
+		ViewNum: latestViewNum,
+	})
+	if shareInfo.Type == models.ShareTypeFile {
 		return utils.HTTPSuccessHandler(c, map[string]any{
 			"token": downloadToken,
 		})