Re: [PATCH 6/6] fsmonitor: Use fsmonitor data in `git diff`
- Date: Thu, 4 Jan 2018 23:46:27 +0100 (STD)
- From: Johannes Schindelin <Johannes.Schindelin@xxxxxx>
- Subject: Re: [PATCH 6/6] fsmonitor: Use fsmonitor data in `git diff`
On Tue, 2 Jan 2018, Alex Vandiver wrote:
> diff --git a/diff-lib.c b/diff-lib.c
> index 8104603a3..13ff00d81 100644
> --- a/diff-lib.c
> +++ b/diff-lib.c
> @@ -95,6 +95,9 @@ int run_diff_files(struct rev_info *revs, unsigned int option)
> diff_set_mnemonic_prefix(&revs->diffopt, "i/", "w/");
> + if (!(option & DIFF_SKIP_FSMONITOR))
> + refresh_fsmonitor(&the_index);
> if (diff_unmerged_stage < 0)
> diff_unmerged_stage = 2;
I read over this hunk five times, and only now am I able to wrap my head
around this: if we do *not* want to skip the fsmonitor data, we refresh
the fsmonitor data in the index.
That feels a bit like an unneeded double negation. Speaking for myself, I
would prefore `DIFF_IGNORE_FSMONITOR` instead, it would feel less like a
double negation then. But I am not a native speaker, so I might be wrong.
> + if (ce->ce_flags & CE_FSMONITOR_VALID && !(option & DIFF_SKIP_FSMONITOR))
> + continue;
Since we do expect this to be called without the DIFF_SKIP_FSMONITOR flag,
I guess it makes sense to order it this way.
I still have troubles to understand why we ignore the fsmonitor data with
`git add`, though... we want to add only modified files, right? I thought
that the fsmonitor data could help performance exactly there (I am
thinking of a certain insanely large code base where a developer might
want to change only one or maybe 3 files out of an entire machine workshop
of files, and with fsmonitor it should be a really fast operation because
it should ignore all but those few files, right?)... Could you maybe try
to help me understand that better?