From f48b128b65b28cca5b23282491af39febf40e2c5 Mon Sep 17 00:00:00 2001
From: keven1024 <keven@fudaoyuan.icu>
Date: Thu, 15 May 2025 23:19:00 +0800
Subject: [PATCH] fix(backend): adjust view count decrement logic in
 VaildateShare to prevent multiple decrements during concurrent downloads

---
 backend/internal/controllers/download.go | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/backend/internal/controllers/download.go b/backend/internal/controllers/download.go
index 40bb466..64a4bfb 100644
--- a/backend/internal/controllers/download.go
+++ b/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,
 		})