git/statinfo.c
Patrick Steinhardt 673af418d0 environment: guard state depending on a repository
In "environment.h" we have quite a lot of functions and variables that
either explicitly or implicitly depend on `the_repository`.

The implicit set of stateful declarations includes for example variables
which get populated when parsing a repository's Git configuration. This
set of variables is broken by design, as their state often depends on
the last repository config that has been parsed. So they may or may not
represent the state of `the_repository`.

Fixing that is quite a big undertaking, and later patches in this series
will demonstrate a solution for a first small set of those variables. So
for now, let's guard these with `USE_THE_REPOSITORY_VARIABLE` so that
callers are aware of the implicit dependency.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-09-12 10:15:42 -07:00

133 lines
3.0 KiB
C

#define USE_THE_REPOSITORY_VARIABLE
#include "git-compat-util.h"
#include "environment.h"
#include "statinfo.h"
/*
* Munge st_size into an unsigned int.
*/
static unsigned int munge_st_size(off_t st_size) {
unsigned int sd_size = st_size;
/*
* If the file is an exact multiple of 4 GiB, modify the value so it
* doesn't get marked as racily clean (zero).
*/
if (!sd_size && st_size)
return 0x80000000;
else
return sd_size;
}
void fill_stat_data(struct stat_data *sd, struct stat *st)
{
sd->sd_ctime.sec = (unsigned int)st->st_ctime;
sd->sd_mtime.sec = (unsigned int)st->st_mtime;
sd->sd_ctime.nsec = ST_CTIME_NSEC(*st);
sd->sd_mtime.nsec = ST_MTIME_NSEC(*st);
sd->sd_dev = st->st_dev;
sd->sd_ino = st->st_ino;
sd->sd_uid = st->st_uid;
sd->sd_gid = st->st_gid;
sd->sd_size = munge_st_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;
if (sd->sd_mtime.sec != (unsigned int)st->st_mtime)
changed |= MTIME_CHANGED;
if (trust_ctime && check_stat &&
sd->sd_ctime.sec != (unsigned int)st->st_ctime)
changed |= CTIME_CHANGED;
#ifdef USE_NSEC
if (check_stat && sd->sd_mtime.nsec != ST_MTIME_NSEC(*st))
changed |= MTIME_CHANGED;
if (trust_ctime && check_stat &&
sd->sd_ctime.nsec != ST_CTIME_NSEC(*st))
changed |= CTIME_CHANGED;
#endif
if (check_stat) {
if (sd->sd_uid != (unsigned int) st->st_uid ||
sd->sd_gid != (unsigned int) st->st_gid)
changed |= OWNER_CHANGED;
if (sd->sd_ino != (unsigned int) st->st_ino)
changed |= INODE_CHANGED;
}
#ifdef USE_STDEV
/*
* st_dev breaks on network filesystems where different
* clients will have different views of what "device"
* the filesystem is on
*/
if (check_stat && sd->sd_dev != (unsigned int) st->st_dev)
changed |= INODE_CHANGED;
#endif
if (sd->sd_size != munge_st_size(st->st_size))
changed |= DATA_CHANGED;
return changed;
}
void stat_validity_clear(struct stat_validity *sv)
{
FREE_AND_NULL(sv->sd);
}
int stat_validity_check(struct stat_validity *sv, const char *path)
{
struct stat st;
if (stat(path, &st) < 0)
return sv->sd == NULL;
if (!sv->sd)
return 0;
return S_ISREG(st.st_mode) && !match_stat_data(sv->sd, &st);
}
void stat_validity_update(struct stat_validity *sv, int fd)
{
struct stat st;
if (fstat(fd, &st) < 0 || !S_ISREG(st.st_mode))
stat_validity_clear(sv);
else {
if (!sv->sd)
CALLOC_ARRAY(sv->sd, 1);
fill_stat_data(sv->sd, &st);
}
}