#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);

  }

}