How to get stats (lines +/-) of diff between index and workdir ?

[Canop]

I'm looking for the equivalent of diff_index_to_workdir, which gives the number of lines added/removed in work directory compared to index.
Is it possible to get it or compute it with gix, starting from a Repository ?

[Byron]

There is a nice example for how to do this with granularity of files here in onefetch.

In order to bring that down to lines granularity one will have to make use of a diff_resource_cache() which unfortunately right now isn't tightly integrated into the index-worktree diff objects yet so it would require some fiddling. Examples are plentiful in the codebase though if you are interested to give it a try nonetheless.

[Byron]

The ObjectID provided as OldOrSource must be the one of a blob, whereas repository.head_id() is a commit. It's interesting it doesn't error, but instead uses an empty blob.
Oh, now I see that it does use the commit data itself. An empty blob may be used if the file doesn't exist (and the ObjectID is null).

[blinxen]

I assumed that I had to specify the commit and gitoxide would magically retrieve the correct file since I also pass the file path to the set_resource. Now it makes a bit more sense but to be honest I am still pretty lost on how to get the object ID of the file from both index and worktree. I can't seem to find any examples on how to work with the index / worktree. Also, why would files that are tracked by git but changed on disk have an object id?

I appreciate the time you take to answer me, I know you are quite busy ;D.

[Byron]

I think the documentation of the function explains it sufficiently well, but if not you are welcome to help make it more clear.
In short, a null object id should be provided if the file should be read from the worktree. Otherwise, it will always be read from the object database.

[blinxen]

After trying out a couple of things, I can see that the documentation was indeed sufficient. My problem here was that when building the cache, I used the default values for the WorktreeRoots struct, which were None. So when trying to access the file in the worktree, gix would always use an empty blob. Thanks for the help!

[Byron]

Thanks for sharing, maybe this is something that should be fixed, as I have trouble seeing a use-case where the ObjectId would be null, and no worktree root is set, which always should mean that it tries to read from disk.
And it's fixed via #1898 .

[Canop]

I understand you refer for example to this : https://github.com/Byron/gitoxide/blob/c4e0a82ec9948ed0d9876a50b156d1ba30e2ad77/gix/tests/object/tree/diff.rs#L11-L53 ?

Does that work for comparing the workdir to the index ?

I'll try. Thanks.

[Byron]

Apologies, but this code would compare two trees with each other, and it has nothing to do with the index file or the work-tree.

[Canop]

BTW, the reason I ask is I'm trying to replace git2 with gix in broot: https://dystroy.org/broot/#check-git-statuses