From: Derrick Stolee <derrickstolee@xxxxxxxxxx>
The GIT_FORCE_UNTRACKED_CACHE environment variable writes the untracked
cache more frequently than the core.untrackedCache config variable. This
is due to how read_directory() handles the creation of an untracked
cache. The old mechanism required using something like 'git update-index
--untracked-cache' before the index would actually contain an untracked
cache. This was noted as a performance problem on macOS in the past, and
this is a resolution for that issue.
The decision to not write the untracked cache without an environment
variable tracks back to fc9ecbeb9 (dir.c: don't flag the index as dirty
for changes to the untracked cache, 2018-02-05). The motivation of that
change is that writing the index is expensive, and if the untracked
cache is the only thing that needs to be written, then it is more
expensive than the benefit of the cache. However, this also means that
the untracked cache never gets populated, so the user who enabled it via
config does not actually get the extension until running 'git
update-index --untracked-cache' manually or using the environment
variable.
We have had a version of this change in the microsoft/git fork for a few
major releases now. It has been working well to get users into a good
state. Yes, that first index write is slow, but the remaining index
writes are much faster than they would be without this change.
Signed-off-by: Derrick Stolee <derrickstolee@xxxxxxxxxx>
---
dir: force untracked cache with core.untrackedCache
We have seen users in the wild that have had core.untrackedCache
enabled, but never actually have an untracked cache created for them. We
have a test in t7063 that shows git status should write the untracked
cache, so I'm not exactly sure how users are in this state for long.
This patch fixes the situation. I also know of another group that sets
GIT_FORCE_UNTRACKED_CACHE=1 in their developer environment in order to
get this behavior.
-Stolee
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1058%2Fderrickstolee%2Funtracked-cache-write-more-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1058/derrickstolee/untracked-cache-write-more-v1
Pull-Request: https://github.com/gitgitgadget/git/pull/1058
dir.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/dir.c b/dir.c
index d91295f2bcd..79a5f6918c8 100644
--- a/dir.c
+++ b/dir.c
@@ -2936,7 +2936,9 @@ int read_directory(struct dir_struct *dir, struct index_state *istate,
if (force_untracked_cache < 0)
force_untracked_cache =
- git_env_bool("GIT_FORCE_UNTRACKED_CACHE", 0);
+ git_env_bool("GIT_FORCE_UNTRACKED_CACHE", -1);
+ if (force_untracked_cache < 0)
+ force_untracked_cache = (istate->repo->settings.core_untracked_cache == UNTRACKED_CACHE_WRITE);
if (force_untracked_cache &&
dir->untracked == istate->untracked &&
(dir->untracked->dir_opened ||
base-commit: b80121027d1247a0754b3cc46897fee75c050b44
--
gitgitgadget
