A new helper to let us pretend that we called lstat() when we know
our cache_entry is up-to-date via fsmonitor.
* jc/fake-lstat:
cache: add fake_lstat()
The index stores file sizes using a uint32_t. This causes any file
that is a multiple of 2^32 to have a cached file size of zero.
Zero is a special value used by racily clean. This causes git to
rehash every file that is a multiple of 2^32 every time git status
or git commit is run.
This patch mitigates the problem by making all files that are a
multiple of 2^32 appear to have a size of 1<<31 instead of zero.
The value of 1<<31 is chosen to keep it as far away from zero
as possible to help prevent things getting mixed up with unpatched
versions of git.
An example would be to have a 2^32 sized file in the index of
patched git. Patched git would save the file as 2^31 in the cache.
An unpatched git would very much see the file has changed in size
and force it to rehash the file, which is safe. The file would
have to grow or shrink by exactly 2^31 and retain all of its
ctime, mtime, and other attributes for old git to not notice
the change.
This patch does not change the behavior of any file that is not
an exact multiple of 2^32.
Signed-off-by: Jason D. Hatton <jhatton@globalfinishing.com>
Signed-off-by: brian m. carlson <bk2204@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
At times, we may already know that a path represented by a
cache_entry ce has no changes via some out-of-line means, like
fsmonitor, and yet need the control to go through a codepath that
requires us to have "struct stat" obtained by lstat() on the path,
for various purposes (e.g. "ie_match_stat()" wants cached stat-info
is still current wrt "struct stat", "diff" wants to know st_mode).
The callers of lstat() on a tracked file, when its cache_entry knows
it is up-to-date, can instead call this helper to pretend that it
called lstat() by faking the "struct stat" information.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
These functions do not depend upon struct cache_entry or struct
index_state in any way, and it seems more logical to break them out into
this file, especially since statinfo.h already has the struct stat_data
declaration.
Diff best viewed with `--color-moved`.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
