From c48a155e78af8fcd707ea3fdc86f250dfe2c2d36 Mon Sep 17 00:00:00 2001
From: Daniel <845765@qq.com>
Date: Tue, 23 Jan 2024 10:48:31 +0800
Subject: [PATCH] :art: Improve data sync to prevent an old snapshot to
 overwrite the new one https://github.com/siyuan-note/siyuan/issues/10229

---
 entity/index.go | 12 ++++++++++++
 sync.go         | 18 +++++++++++++++++-
 2 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/entity/index.go b/entity/index.go
index 6f5ef5b..d9b1108 100644
--- a/entity/index.go
+++ b/entity/index.go
@@ -16,6 +16,13 @@
 
 package entity
 
+import (
+	"fmt"
+	"time"
+
+	"github.com/dustin/go-humanize"
+)
+
 // Index 描述了快照索引。
 type Index struct {
 	ID           string   `json:"id"`           // Hash
@@ -30,6 +37,11 @@ type Index struct {
 	CheckIndexID string   `json:"checkIndexID"` // Check Index ID
 }
 
+func (index *Index) String() string {
+	return fmt.Sprintf("device=%s/%s, id=%s, files=%d, size=%s, created=%s",
+		index.SystemID, index.SystemOS, index.ID, len(index.Files), humanize.Bytes(uint64(index.Size)), time.UnixMilli(index.Created).Format("2006-01-02 15:04:05"))
+}
+
 // CheckIndex 描述了一个 Index 对应的数据 ID，包括 File ID 和 Chunk ID。
 //
 // 该结构体在数据同步云端时根据本地 Latest Index 生成，在云端服务上用于校验数据完整性。
diff --git a/sync.go b/sync.go
index b717c4c..5082d3b 100644
--- a/sync.go
+++ b/sync.go
@@ -506,10 +506,10 @@ func (repo *Repo) updateCloudIndexes(latest, cloudLatest *entity.Index, trafficS
 		latestRef, downloadErr := repo.downloadCloudObject("refs/latest")
 		if nil == downloadErr {
 			if cloudLatest.ID != string(latestRef) {
+				logging.LogWarnf("cloud latest changed [old=%s, new=%s]", cloudLatest.ID, latestRef)
 				errLock.Lock()
 				errs = append(errs, cloud.ErrCloudIndexChanged)
 				errLock.Unlock()
-				logging.LogWarnf("cloud latest changed [old=%s, new=%s]", cloudLatest.ID, latestRef)
 				return
 			}
 		}
@@ -563,6 +563,22 @@ func (repo *Repo) updateCloudIndexes(latest, cloudLatest *entity.Index, trafficS
 			}
 			if !bytes.Equal(latestData, downloadedData) {
 				logging.LogWarnf("confirm [%d] uploaded cloud [refs/latest] failed [local=%s, downloaded=%s]", i, latestData, downloadedData)
+
+				// 如果是不同设备上传的，则判定为数据已经改变 https://github.com/siyuan-note/siyuan/issues/10229
+				_, latestCloudIndex, downloadIdxErr := repo.downloadCloudIndex(string(downloadedData), context)
+				if nil != downloadIdxErr {
+					logging.LogWarnf("download [refs/latest] failed: %s", downloadIdxErr)
+					continue
+				}
+
+				if nil != latestCloudIndex && latestCloudIndex.SystemID != latest.SystemID {
+					logging.LogWarnf("cloud latest changed, current [%s], cloud [%s]", latest.String(), latestCloudIndex.String())
+					errLock.Lock()
+					errs = append(errs, cloud.ErrCloudIndexChanged)
+					errLock.Unlock()
+					return
+				}
+
 				latestData, length, uploadErr = repo.updateCloudRef("refs/latest", context)
 				if nil != uploadErr {
 					logging.LogWarnf("fix [%d] uploaded cloud [refs/latest, %s] failed: %s", i, latestData, uploadErr)