[PATCH 1/1] unpack-trees: skip lstat based on fsmonitor

From: "Utsav Shah via GitGitGadget" <gitgitgadget@gmail.com>
To: git@vger.kernel.org
Cc: Utsav Shah <ukshah2@illinois.edu>,
	Junio C Hamano <gitster@pobox.com>,
	Utsav Shah <utsav@dropbox.com>
Subject: [PATCH 1/1] unpack-trees: skip lstat based on fsmonitor
Date: Fri, 25 Oct 2019 15:23:28 +0000	[thread overview]
Message-ID: <609c7c5047719a619ba22425dafc6ecd105e2cda.1572017008.git.gitgitgadget@gmail.com> (raw)
In-Reply-To: <pull.424.git.1572017008.gitgitgadget@gmail.com>

From: Utsav Shah <utsav@dropbox.com>

git stash runs git reset --hard as its final step, which can be fairly slow on a large repository.
This change lets us skip that if fsmonitor thinks those files aren't modified.

git stash goes from ~8s -> 2s on my repository after this change.

Signed-off-by: Utsav Shah <utsav@dropbox.com>
---
 unpack-trees.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/unpack-trees.c b/unpack-trees.c
index 33ea7810d8..5d07a2d0ea 100644
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -2384,7 +2384,8 @@ int oneway_merge(const struct cache_entry * const *src,
 
 	if (old && same(old, a)) {
 		int update = 0;
-		if (o->reset && o->update && !ce_uptodate(old) && !ce_skip_worktree(old)) {
+		if (o->reset && o->update && !ce_uptodate(old) && !ce_skip_worktree(old) &&
+		    !(old->ce_flags & CE_FSMONITOR_VALID)) {
 			struct stat st;
 			if (lstat(old->name, &st) ||
 			    ie_match_stat(o->src_index, old, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE))
-- 
gitgitgadget
