libgit2 / libgit2/libgit2sharp
RewriteHistory extremely slow
还没有人认领这个 Issue。
- 主要语言
- C#
- 星标
- 3.5k
- 派生
- 925
- PR 合并指标
- 30 天内没有已合并 PR
描述
Reproduction steps
Find a repo with 3000+ commits
Run the below code against that repo to rewrite the repo history:
private static void RewriteHistory(string repoPath, ICollection<string> subFolders)
{
using (var repo = new Repository(repoPath))
{
var refs = repo.Refs.Where(r => r.CanonicalName.EndsWith("develop")).OrderBy(r => r.CanonicalName).ToList();
var commits = repo.Commits.QueryBy(new CommitFilter { IncludeReachableFrom = refs }).ToArray();
var count = 0;
var stopwatch = Stopwatch.StartNew();
Logger.InfoFormat("Found {0} commits", commits.Length);
Logger.InfoFormat("Rewrite history started");
repo.Refs.RewriteHistory(new RewriteHistoryOptions
{
OnError = OnError,
OnSucceeding = OnSucceeding,
PruneEmptyCommits = true,
CommitTreeRewriter = commit =>
{
Logger.InfoFormat("Commit {0}/{1}", ++count, commits.Length);
var tree = TreeDefinition.From(commit);
foreach (var treeEntry in commit.Tree)
{
var match = subFolders.FirstOrDefault(s => treeEntry.Path.StartsWithIgnoreCase(s));
if (match == null)
tree.Remove(treeEntry.Path);
}
return tree;
}
}, commits);
Logger.InfoFormat("Rewrite history ended. Took {0}", stopwatch.Elapsed);
repo.Reset(ResetMode.Hard, repo.Head.Commits.First());
}
}
Expected behavior
This should take a reasonable time. I expect it to take a few minutes for sure but not hours. For example when running something similar in git from the command like it takes minutes. I'm sorry I don't have specific times but I can try to provide more data to compare performance if necessary.
Actual behavior
This takes 1h 43 minutes of which 1h 40 to just start the rewrite and about a couple of minutes to go through all the commits.
INFO : Found 3486 commits
INFO : Rewrite history started
[between these two log messages there is a 1h 40m gap]
INFO : Commit 1/3486
INFO : Commit 2/3486
...
INFO : Rewrite history ended. Took 01:43:51.5536779
Version of LibGit2Sharp (release number or SHA1)
0.26.0 + 2.0.267 (native)
Operating system(s) tested; .NET runtime tested
.net 4.6.1 - Win 2012R2
贡献指南
从这里开始
- 先读完整个 Issue,再读项目的贡献指南。
- 在 Issue 下留言说明你要接手 —— 这能避免两个人做同样的事。
- Fork 仓库,在一个分支上完成修改。
- 提交 Pull Request,并在描述里引用这个 Issue 编号。
调研方向
首先,使用包含 3,000 多个提交的 repository 重现该报告,并测量“Rewrite history started”与第一个 CommitTreeRewriter callback 之间的延迟。检查 issue 中显示的 RewriteHistory 调用及其 CommitTreeRewriter 设置。当相同的历史重写在几分钟而不是几小时内完成,同时保留报告中的 pruning 行为时,即表示完成。
由索引模型根据 Issue 内容生成。
评估
- 技术栈
- csharp, git
- 领域
- devtools, performance
- Issue 类型
- 缺陷
- 难度
- 4/5
- 预计耗时
- 3-5 天
- 活跃度
- 停滞
- 描述清晰度
- 基本清楚
- 新手友好度
- 35/100