On Tue, 2020-08-25 at 14:23 +0200, Rasmus Villemoes wrote:
> On 25/08/2020 02.09, Joe Perches wrote:
> > If a file exists in git and checkpatch is used without the -f
> > flag for scanning a file, then checkpatch will scan the file
> > assuming it's a patch
[]
> > +sub git_is_single_file {
> > + my ($filename) = @_;
> > +
> > + return 0 if ((which("git") eq "") || !(-e "$gitroot"));
> > +
> > + my $output = `${git_command} ls-files -- $filename`;
> > + my $count = $output =~ tr/\n//;
> > + return $count eq 1 && $output =~ m{^${filename}$};
> > +}
>
> Isn't that somewhat expensive to do for each file?
Just FYI: Not really.
On my 4 year old laptop git ls-files -- <file> takes
about .02 seconds.
$ time git ls-files -- 'net/l2tp/l2tp_ip.c'
net/l2tp/l2tp_ip.c
real 0m0.013s
user 0m0.009s
sys 0m0.004s
Even uncached, it's quite quick.
# sync; echo 3 > /proc/sys/vm/drop_caches
$ time git ls-files -- 'net/l2tp/l2tp_ip.c'
net/l2tp/l2tp_ip.c
real 0m0.079s
user 0m0.004s
sys 0m0.037s
cheers, Joe
