cache: add fake_lstat()

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>

1 files changed, 27 insertions, 0 deletions

diff --git a/statinfo.c b/statinfo.c
index 17bb8966c3..45156109de 100644
--- a/statinfo.c
+++ b/statinfo.c
@@ -15,6 +15,33 @@ void fill_stat_data(struct stat_data *sd, struct stat *st)
 	sd->sd_size = st->st_size;
 }
 
+static void set_times(struct stat *st, const struct stat_data *sd)
+{
+	st->st_ctime = sd->sd_ctime.sec;
+	st->st_mtime = sd->sd_mtime.sec;
+#ifdef NO_NSEC
+	; /* nothing */
+#else
+#ifdef USE_ST_TIMESPEC
+	st->st_ctimespec.tv_nsec = sd->sd_ctime.nsec;
+	st->st_mtimespec.tv_nsec = sd->sd_mtime.nsec;
+#else
+	st->st_ctim.tv_nsec = sd->sd_ctime.nsec;
+	st->st_mtim.tv_nsec = sd->sd_mtime.nsec;
+#endif
+#endif
+}
+
+void fake_lstat_data(const struct stat_data *sd, struct stat *st)
+{
+	set_times(st, sd);
+	st->st_dev = sd->sd_dev;
+	st->st_ino = sd->sd_ino;
+	st->st_uid = sd->sd_uid;
+	st->st_gid = sd->sd_gid;
+	st->st_size = sd->sd_size;
+}
+
 int match_stat_data(const struct stat_data *sd, struct stat *st)
 {
 	int changed = 0;