git/statinfo.c
Junio C Hamano 01f86ebb95 Merge branch 'jc/fake-lstat'
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()
2023-12-27 14:52:24 -08:00

131 lines
3.0 KiB
C

#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);
}
}