When we "git checkout $tree", we pull paths from $tree into
the index, and then check the resulting entries out to the
worktree. Our method for the first step is rather
heavy-handed, though; it clobbers the entire existing index
entry, even if the content is the same. This means we lose
our stat information, leading checkout_entry to later
rewrite the entire file with identical content.
Instead, let's see if we have the identical entry already in
the index, in which case we leave it in place. That lets
checkout_entry do the right thing. Our tests cover two
interesting cases:
1. We make sure that a file which has no changes is not
rewritten.
2. We make sure that we do update a file that is unchanged
in the index (versus $tree), but has working tree
changes. We keep the old index entry, and
checkout_entry is able to realize that our stat
information is out of date.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In checkout_paths() we do this
- for all updated items, call match_pathspec
- for all items, call match_pathspec (inside unmerge_cache)
- for all items, call match_pathspec (for showing "path .. is unmerged)
- for updated items, call match_pathspec and update paths
That's a lot of duplicate match_pathspec(s) and the function is not
exactly cheap to be called so many times, especially on large indexes.
This patch makes it call match_pathspec once per updated index entry,
save the result in ce_flags and reuse the results in the following
loops.
The changes in 0a1283b (checkout $tree $path: do not clobber local
changes in $path not in $tree - 2011-09-30) limit the affected paths
to ones we read from $tree. We do not do anything to other modified
entries in this case, so the "for all items" above could be modified
to "for all updated items". But..
The command's behavior now is modified slightly: unmerged entries that
match $path, but not updated by $tree, are now NOT touched. Although
this should be considered a bug fix, not a regression. A new test is
added for this change.
And while at there, free ps_matched after use.
The following command is tested on webkit, 215k entries. The pattern
is chosen mainly to make match_pathspec sweat:
git checkout -- "*[a-zA-Z]*[a-zA-Z]*[a-zA-Z]*"
before after
real 0m3.493s 0m2.737s
user 0m2.239s 0m1.586s
sys 0m1.252s 0m1.151s
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Checking paths out of a tree is (currently) defined to do:
- Grab the paths from the named tree that match the given pathspec,
and add them to the index;
- Check out the contents from the index for paths that match the
pathspec to the working tree; and while at it
- If the given pathspec did not match anything, suspect a typo from the
command line and error out without updating the index nor the working
tree.
Suppose that the branch you are working on has dir/myfile, and the "other"
branch has dir/other but not dir/myfile. Further imagine that you have
either modified or removed dir/myfile in your working tree, but you have
not run "git add dir/myfile" or "git rm dir/myfile" to tell Git about your
local change. Running
$ git checkout other dir
would add dir/other to the index with the contents taken out of the
"other" branch, and check out the paths from the index that match the
pathspec "dir", namely, "dir/other" and "dir/myfile", overwriting your
local changes to "dir/myfile", even though "other" branch does not even
know about that file.
Fix it by updating the working tree only with the index entries that
was read from the "other" tree.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Jeff King
Nguyễn Thái Ngọc Duy
Junio C Hamano