Re: Watchman support for git

[David Turner <dturner@twopensource.com>]

On Wed, 2014-05-14 at 05:54 +0700, Duy Nguyen wrote:
> On Wed, May 14, 2014 at 5:38 AM, David Turner <dturner@twopensource.com> wrote:
> > On Mon, 2014-05-12 at 17:45 +0700, Duy Nguyen wrote:
> >> This is your quote from above, moved down a bit:
> >>
> >> > update_fs_cache should only have to update based on what it has learned
> >> > from watchman.  So if no .gitignore has been changed, it should not have
> >> > to do very much work.
> >> >
> >> > I could take the fe_excluded check and move it above the
> >> > last_exclude_matching check in fs_cache_is_excluded; it causes t7300 to
> >> > fail when run under watchman but presumably that's fixable
> >>
> >> So you exclude files early and make the real read_directory() pass do
> >> pretty much nothing. This is probably not a good idea. Assume that I
> >> touch $TOP/.gitignore then do something other than "git status" (or
> >> "git add") then I have to pay read_directory() cost.
> >
> > I'm not sure I understand this. read_directory does something: it checks
> > the fs_cache (instead of the filesystem) for untracked files.
> 
> A lot of commands do read_cache() that that eventually calls
> update_fs_cache, which does part of read_directory's work (the
> fe_excluded thing). But not many of those commands actually call
> read_directory(). It'd better if there's a way to mark that "this
> .gitignore is changed", but delay the actual exclude processsing until
> we are sure read_directory() will be used.

OK, that would be straighforward, I think.