statinfo.h

   1 #ifndef STATINFO_H
   2 #define STATINFO_H
   3
   4 struct index_state;
   5
   6 /*
   7  * The "cache_time" is just the low 32 bits of the
   8  * time. It doesn't matter if it overflows - we only
   9  * check it for equality in the 32 bits we save.
  10  */
  11 struct cache_time {
  12         uint32_t sec;
  13         uint32_t nsec;
  14 };
  15
  16 struct stat_data {
  17         struct cache_time sd_ctime;
  18         struct cache_time sd_mtime;
  19         unsigned int sd_dev;
  20         unsigned int sd_ino;
  21         unsigned int sd_uid;
  22         unsigned int sd_gid;
  23         unsigned int sd_size;
  24 };
  25
  26 /*
  27  * A struct to encapsulate the concept of whether a file has changed
  28  * since we last checked it. This uses criteria similar to those used
  29  * for the index.
  30  */
  31 struct stat_validity {
  32         struct stat_data *sd;
  33 };
  34
  35 #define MTIME_CHANGED   0x0001
  36 #define CTIME_CHANGED   0x0002
  37 #define OWNER_CHANGED   0x0004
  38 #define MODE_CHANGED    0x0008
  39 #define INODE_CHANGED   0x0010
  40 #define DATA_CHANGED    0x0020
  41 #define TYPE_CHANGED    0x0040
  42
  43 /*
  44  * Record to sd the data from st that we use to check whether a file
  45  * might have changed.
  46  */
  47 void fill_stat_data(struct stat_data *sd, struct stat *st);
  48
  49 /*
  50  * Return 0 if st is consistent with a file not having been changed
  51  * since sd was filled.  If there are differences, return a
  52  * combination of MTIME_CHANGED, CTIME_CHANGED, OWNER_CHANGED,
  53  * INODE_CHANGED, and DATA_CHANGED.
  54  */
  55 int match_stat_data(const struct stat_data *sd, struct stat *st);
  56
  57 void stat_validity_clear(struct stat_validity *sv);
  58
  59 /*
  60  * Returns 1 if the path is a regular file (or a symlink to a regular
  61  * file) and matches the saved stat_validity, 0 otherwise.  A missing
  62  * or inaccessible file is considered a match if the struct was just
  63  * initialized, or if the previous update found an inaccessible file.
  64  */
  65 int stat_validity_check(struct stat_validity *sv, const char *path);
  66
  67 /*
  68  * Update the stat_validity from a file opened at descriptor fd. If
  69  * the file is missing, inaccessible, or not a regular file, then
  70  * future calls to stat_validity_check will match iff one of those
  71  * conditions continues to be true.
  72  */
  73 void stat_validity_update(struct stat_validity *sv, int fd);
  74
  75 #endif