status: only touch path we may need to check
This patch gets rid of whole-tree cache refresh and untracked file
search. Instead only specified path will be looked at.
Again some numbers on gentoo-x86, ~80k files:
Unmodified Git:
$ time git st eclass/
nothing to commit (working directory clean)
real 0m3.211s
user 0m1.977s
sys 0m1.135s
Modified Git:
$ time ~/w/git/git st eclass/
nothing to commit (working directory clean)
real 0m1.587s
user 0m1.426s
sys 0m0.111s
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>