Re: [PATCH v7 04/12] fsmonitor: teach git to optionally utilize a file system monitor to speed up detecting new or changed files.

[Junio C Hamano <gitster@pobox.com>]

Ben Peart <benpeart@microsoft.com> writes:

> @@ -344,6 +346,7 @@ struct index_state {
>  	struct hashmap dir_hash;
>  	unsigned char sha1[20];
>  	struct untracked_cache *untracked;
> +	uint64_t fsmonitor_last_update;

This field being zero has more significance than just "we haven't
got any update yet", right?  The way I am reading the code is that
setting it 0 is a way to signal that fsmon has been inactivated.  It
also made me wonder if add_fsmonitor() that silently returns without
doing anything when this field is already non-zero is a bug (in
other words, I couldn't tell what the right answer would be to a
question "shouldn't the caller be avoiding duplicate calls?").

> diff --git a/fsmonitor.c b/fsmonitor.c
> new file mode 100644
> index 0000000000..b8b2d88fe1
> --- /dev/null
> +++ b/fsmonitor.c
> ...

This part was a pleasant read.

Thanks.