git-sync-web 自动提交 2026-09-08 18:21:40

git.go

@@ -87,6 +87,42 @@ func branchExists(path, branch string) bool {
 	return err == nil
 }
 
+// remoteTip 返回远程分支当前指向的 SHA。
+// 优先读本地远程跟踪引用（refs/remotes/<remote>/<branch>，快）；
+// 若本地跟踪引用不可用（个别环境下 ref 存储读写异常），回退用 ls-remote 直查远程。
+func remoteTip(path, remote, branch string) (sha string, exists bool) {
+	if remoteRefExists(path, remote, branch) {
+		out, err := gitRun(path, 15*time.Second, "rev-parse", remote+"/"+branch)
+		if err == nil {
+			return strings.TrimSpace(out), true
+		}
+	}
+	out, err := gitRun(path, 30*time.Second, "ls-remote", remote, "refs/heads/"+branch)
+	if err != nil {
+		return "", false
+	}
+	fields := strings.Fields(strings.TrimSpace(out))
+	if len(fields) < 2 {
+		return "", false
+	}
+	return fields[0], true
+}
+
+// aheadBehindSha 基于远程分支的具体 SHA 计算 (领先, 落后)，不依赖本地跟踪引用
+func aheadBehindSha(path, tip string) (int, int, error) {
+	out, err := gitRun(path, 30*time.Second, "rev-list", "--left-right", "--count", "HEAD..."+tip)
+	if err != nil {
+		return 0, 0, err
+	}
+	parts := strings.Fields(out)
+	if len(parts) != 2 {
+		return 0, 0, fmt.Errorf("无法解析 rev-list 输出: %q", out)
+	}
+	a, _ := strconv.Atoi(parts[0])
+	b, _ := strconv.Atoi(parts[1])
+	return a, b, nil
+}
+
 func dirtyCount(path string) int {
 	out, err := gitRun(path, 30*time.Second, "status", "--porcelain")
 	if err != nil {