Is there a way to detect that newer performance optimizations are enabled?

[eamodio]

We are working on a new Commit Graph in GitLens and some newer performance optimizations like the commit-graph and file watching can have a very large impact on performance for some repositories. For example, writing a commit-graph for the linux repo on my machine cut the time to open our Graph from ~8s to ~1 (with the same reduction on paging in new data too).

As far as I can tell, there doesn't seem to be a git command to tell me if there is a commit-graph or tell if maintenance is setup. For the FSMonitor I can read the [core.fsmonitor](https://git-scm.com/docs/git-config#Documentation/git-config.txt-corefsmonitor) setting at least.

Should I be looking for the existence of the commit-graph file itself, but then how could I tell how it was generated, e.g. with --reachable or --changed-paths etc.

Any guidance would be greatly appreciated!

[derrickstolee]

To determine if these things are available, Git itself uses its config and parsing code to detect first "Is this feature enabled?" and second "Is this feature available?"

I mention this in that the commit-graph is enabled by default, but might not actually be written locally. Git's checks are "is core.commitGraph enabled?" and then "does the commit-graph file exist?" You can consider looking into the $GIT_DIR/objects/info/ for a commit-graph file or a commit-graphs directory. Looking into Git at that level is fragile as Git can change things (usually by adding new formats, but not by removing those as possibilities).

[derrickstolee]

Oh, and you can't tell that it was built by --reachable or not, but the --changed-paths option adds extra data to the commit-graph file. I don't think there is any way to find out about that kind of internal information any other way.

[eamodio]

Thanks for the info. Do you know of any plans to track that metadata as to how it was created?