repo.Commits.QueryBy(filename) slow on large repos

Reproduction steps

1): Clone a large repo 2): run this function on that repo with some random file:

public IEnumerable<string> TestSlow(string filename)
{
    using (var repo = new Repository(repoRoot))
    {
        string path = filename.Substring(repoRoot.Length + 1).Replace("\\", "/");
        foreach (LogEntry entry in repo.Commits.QueryBy(path))
        {
            yield return entry.Commit.Author.ToString();
        }
    }
}

1. run this command on the same file: “git log --follow --oneline – <file>”

Expected behavior

I expect similar time to be taken by TestSlow and the git log command above

Actual behavior

The git log command finishes in about 1.6 ms on my repo The TestSlow command takes about 70 seconds.

Here is what I see in my profiler:

Version of LibGit2Sharp (release number or SHA1)

0.27.0-preview-0017 0.26.1 0.24.1

Operating system(s) tested; .NET runtime tested

.NET Framework 4.7.2 on Windows 10

[blackboxlogic]

@Blueve Could you share your code for parsing the git.exe output?

[Blueve]

Awesome work! I met same issue and I have to wrap a git.exe and use git log to speed up the log reading.