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  * The inverse of the above.  When we know the cache_entry that
  51  * contains sd is up-to-date, but still need to pretend we called
  52  * lstat() to learn that fact, this function fills "st" enough to
  53  * fool ie_match_stat().
  54  */
  55 void fake_lstat_data(const struct stat_data *sd, struct stat *st);
  56
  57 /*
  58  * Return 0 if st is consistent with a file not having been changed
  59  * since sd was filled.  If there are differences, return a
  60  * combination of MTIME_CHANGED, CTIME_CHANGED, OWNER_CHANGED,
  61  * INODE_CHANGED, and DATA_CHANGED.
  62  */
  63 int match_stat_data(const struct stat_data *sd, struct stat *st);
  64
  65 void stat_validity_clear(struct stat_validity *sv);
  66
  67 /*
  68  * Returns 1 if the path is a regular file (or a symlink to a regular
  69  * file) and matches the saved stat_validity, 0 otherwise.  A missing
  70  * or inaccessible file is considered a match if the struct was just
  71  * initialized, or if the previous update found an inaccessible file.
  72  */
  73 int stat_validity_check(struct stat_validity *sv, const char *path);
  74
  75 /*
  76  * Update the stat_validity from a file opened at descriptor fd. If
  77  * the file is missing, inaccessible, or not a regular file, then
  78  * future calls to stat_validity_check will match iff one of those
  79  * conditions continues to be true.
  80  */
  81 void stat_validity_update(struct stat_validity *sv, int fd);
  82
  83 #if defined(DT_UNKNOWN) && !defined(NO_D_TYPE_IN_DIRENT)
  84 #define DTYPE(de)       ((de)->d_type)
  85 #else
  86 #undef DT_UNKNOWN
  87 #undef DT_DIR
  88 #undef DT_REG
  89 #undef DT_LNK
  90 #define DT_UNKNOWN      0
  91 #define DT_DIR          1
  92 #define DT_REG          2
  93 #define DT_LNK          3
  94 #define DTYPE(de)       DT_UNKNOWN
  95 #endif
  96
  97 #endif