Hacktoberfest 2026:维护者为十月标记出来的 issue,仍然开放、适合新手。 浏览 Hacktoberfest issue

ngclient: Be better with concurrent instances

未关闭
#2,836 7 条评论 0 个 reaction 已指派 0 人 在 GitHub 查看

维护者通常 10 天内回复

还没有人认领这个 Issue。

评估

难度
5/5
预计耗时
一周以上
新手友好度
25/100
Issue 类型
功能
描述清晰度
需要澄清
活跃度
停滞
技术栈
python
领域
backend

调研方向

首先阅读 ngclient 的 Updater 流程,尤其是 refresh()、get_targetinfo() 和 download_target(),并跟踪 metadata 和 target 文件在本地缓存中的读取或写入位置。为跨进程锁的创建、等待、过期锁和锁范围定义并记录并发策略;当这些未决问题都有一致同意的实现路径时,该 issue 即完成。

由索引模型根据 Issue 内容生成。

描述

Users may run multiple updaters at the same time -- it's not useful but it can happen with longer dependency chains like https://github.com/sigstore/sigstore-python/issues/1403: model-signing uses sigstore-python which uses python-tuf...

Currently we don't handle the potential conflicts WRT reading and writing metadata and target files to local cache that result from concurrent updaters. This is especially an issue with windows where concurrent file access leads to issues more often but it can be problematic in linux too -- this is why currently we just document Updater as "should be a singleton".

Possible improvement: lockfile

I think it makes sense to not try to solve this for just a single process but multiple real processes running updaters (something I can easily imagine happening in real life). In that case I think a lock file per repository would be best we can do:

  • check for lock file before reading/writing
  • create lock file, read/write, remove lock file

The reason this hasn't been done is that lockfiles are a pain to do especially cross platform.

Some open questions:

  • what to do when a lock file exists -- log a warning and wait (for how long?)? I don't usually like when libraries wait for things but maybe this works? What if the lock file is stale (let's say hours old)?
  • manually handling lockfiles in a way that works on windows is painful... but we've also done a lot of work to avoid unnecessary dependencies in this project. Using a dependency for this is likely the smaller evil
  • when exactly do we lock?
    • locking for lifetime of Updater probably has annoying side effects and is not expected by users
    • locking for duration of refresh() and get_targetinfo() seems logical at least at first glance. Locking for duration of download_target() is probably less important but could be done
Possible improvement: global state

If we are not interested in multiple processes but just multiple threads with updaters, we could always add some global state tracking... It sounds quite unappealing but possible. I feel like I'd rather advice python-tuf users to use ngclient Updater as a "per-repository-singleton"?

CC @spencerschrock, let me know if you have thoughts

主要语言
Python
星标
1.7k
派生
304
平均合并
9 小时 25 分钟
30 天内合并 PR
14

环境准备

从这里开始

  1. 先读完整个 Issue,再读项目的贡献指南。
  2. 在 Issue 下留言说明你要接手 —— 这能避免两个人做同样的事。
  3. Fork 仓库,在一个分支上完成修改。
  4. 提交 Pull Request,并在描述里引用这个 Issue 编号。

theupdateframework/python-tuf 的其他 Issue

查看 theupdateframework/python-tuf 的全部 Issue

相似的 Issue

更多 Python Issue

把新 issue 发到你的邮箱

精选适合新手参与的 GitHub issue 摘要。