include/stat-time.h

   1 /* stat-related time functions.
   2
   3    Copyright (C) 2005, 2007, 2009-2012 Free Software Foundation, Inc.
   4
   5    This program is free software: you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 3 of the License, or
   8    (at your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  17
  18 /* Written by Paul Eggert.  */
  19
  20 #ifndef STAT_TIME_H
  21 #define STAT_TIME_H 1
  22
  23 #include <sys/stat.h>
  24
  25 #if defined (TIME_H_DEFINES_STRUCT_TIMESPEC)
  26 #  include <time.h>
  27 #elif defined (SYS_TIME_H_DEFINES_STRUCT_TIMESPEC)
  28 #  include <sys/time.h>
  29 #elif defined (PTHREAD_H_DEFINES_STRUCT_TIMESPEC)
  30 #  include <pthread.h>
  31 #endif
  32
  33 #ifndef HAVE_STRUCT_TIMESPEC
  34 struct timespec
  35 {
  36   time_t tv_sec;
  37   long int tv_nsec;
  38 };
  39 #endif
  40
  41 /* STAT_TIMESPEC (ST, ST_XTIM) is the ST_XTIM member for *ST of type
  42    struct timespec, if available.  If not, then STAT_TIMESPEC_NS (ST,
  43    ST_XTIM) is the nanosecond component of the ST_XTIM member for *ST,
  44    if available.  ST_XTIM can be st_atim, st_ctim, st_mtim, or st_birthtim
  45    for access, status change, data modification, or birth (creation)
  46    time respectively.
  47
  48    These macros are private to stat-time.h.  */
  49 #if defined HAVE_STRUCT_STAT_ST_ATIM_TV_NSEC
  50 # ifdef TYPEOF_STRUCT_STAT_ST_ATIM_IS_STRUCT_TIMESPEC
  51 #  define STAT_TIMESPEC(st, st_xtim) ((st)->st_xtim)
  52 # else
  53 #  define STAT_TIMESPEC_NS(st, st_xtim) ((st)->st_xtim.tv_nsec)
  54 # endif
  55 #elif defined HAVE_STRUCT_STAT_ST_ATIMESPEC_TV_NSEC
  56 # define STAT_TIMESPEC(st, st_xtim) ((st)->st_xtim##espec)
  57 #elif defined HAVE_STRUCT_STAT_ST_ATIMENSEC
  58 # define STAT_TIMESPEC_NS(st, st_xtim) ((st)->st_xtim##ensec)
  59 #elif defined HAVE_STRUCT_STAT_ST_ATIM_ST__TIM_TV_NSEC
  60 # define STAT_TIMESPEC_NS(st, st_xtim) ((st)->st_xtim.st__tim.tv_nsec)
  61 #endif
  62
  63 /* Return the nanosecond component of *ST's access time.  */
  64 static inline long int
  65 get_stat_atime_ns (struct stat const *st)
  66 {
  67 # if defined STAT_TIMESPEC
  68   return STAT_TIMESPEC (st, st_atim).tv_nsec;
  69 # elif defined STAT_TIMESPEC_NS
  70   return STAT_TIMESPEC_NS (st, st_atim);
  71 # else
  72   return 0;
  73 # endif
  74 }
  75
  76 /* Return the nanosecond component of *ST's status change time.  */
  77 static inline long int
  78 get_stat_ctime_ns (struct stat const *st)
  79 {
  80 # if defined STAT_TIMESPEC
  81   return STAT_TIMESPEC (st, st_ctim).tv_nsec;
  82 # elif defined STAT_TIMESPEC_NS
  83   return STAT_TIMESPEC_NS (st, st_ctim);
  84 # else
  85   return 0;
  86 # endif
  87 }
  88
  89 /* Return the nanosecond component of *ST's data modification time.  */
  90 static inline long int
  91 get_stat_mtime_ns (struct stat const *st)
  92 {
  93 # if defined STAT_TIMESPEC
  94   return STAT_TIMESPEC (st, st_mtim).tv_nsec;
  95 # elif defined STAT_TIMESPEC_NS
  96   return STAT_TIMESPEC_NS (st, st_mtim);
  97 # else
  98   return 0;
  99 # endif
 100 }
 101
 102 /* Return the nanosecond component of *ST's birth time.  */
 103 static inline long int
 104 get_stat_birthtime_ns (struct stat const *st)
 105 {
 106 # if defined HAVE_STRUCT_STAT_ST_BIRTHTIMESPEC_TV_NSEC
 107   return STAT_TIMESPEC (st, st_birthtim).tv_nsec;
 108 # elif defined HAVE_STRUCT_STAT_ST_BIRTHTIMENSEC
 109   return STAT_TIMESPEC_NS (st, st_birthtim);
 110 # else
 111   /* Avoid a "parameter unused" warning.  */
 112   (void) st;
 113   return 0;
 114 # endif
 115 }
 116
 117 /* Return *ST's access time.  */
 118 static inline struct timespec
 119 get_stat_atime (struct stat const *st)
 120 {
 121 #ifdef STAT_TIMESPEC
 122   return STAT_TIMESPEC (st, st_atim);
 123 #else
 124   struct timespec t;
 125   t.tv_sec = st->st_atime;
 126   t.tv_nsec = get_stat_atime_ns (st);
 127   return t;
 128 #endif
 129 }
 130
 131 /* Return *ST's status change time.  */
 132 static inline struct timespec
 133 get_stat_ctime (struct stat const *st)
 134 {
 135 #ifdef STAT_TIMESPEC
 136   return STAT_TIMESPEC (st, st_ctim);
 137 #else
 138   struct timespec t;
 139   t.tv_sec = st->st_ctime;
 140   t.tv_nsec = get_stat_ctime_ns (st);
 141   return t;
 142 #endif
 143 }
 144
 145 /* Return *ST's data modification time.  */
 146 static inline struct timespec
 147 get_stat_mtime (struct stat const *st)
 148 {
 149 #ifdef STAT_TIMESPEC
 150   return STAT_TIMESPEC (st, st_mtim);
 151 #else
 152   struct timespec t;
 153   t.tv_sec = st->st_mtime;
 154   t.tv_nsec = get_stat_mtime_ns (st);
 155   return t;
 156 #endif
 157 }
 158
 159 static inline int
 160 timespec_cmp (struct timespec a, struct timespec b)
 161 {
 162   return (a.tv_sec < b.tv_sec
 163             ? -1
 164             : (a.tv_sec > b.tv_sec
 165                  ? 1
 166                  : (int) (a.tv_nsec - b.tv_nsec)));
 167 }
 168
 169 /* Return *ST's birth time, if available; otherwise return a value
 170    with tv_sec and tv_nsec both equal to -1.  */
 171 static inline struct timespec
 172 get_stat_birthtime (struct stat const *st)
 173 {
 174   struct timespec t;
 175
 176 #if (defined HAVE_STRUCT_STAT_ST_BIRTHTIMESPEC_TV_NSEC \
 177      || defined HAVE_STRUCT_STAT_ST_BIRTHTIM_TV_NSEC)
 178   t = STAT_TIMESPEC (st, st_birthtim);
 179 #elif defined HAVE_STRUCT_STAT_ST_BIRTHTIMENSEC
 180   t.tv_sec = st->st_birthtime;
 181   t.tv_nsec = st->st_birthtimensec;
 182 #elif (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
 183   /* Native Windows platforms (but not Cygwin) put the "file creation
 184      time" in st_ctime (!).  See
 185      <http://msdn2.microsoft.com/de-de/library/14h5k7ff(VS.80).aspx>.  */
 186   t.tv_sec = st->st_ctime;
 187   t.tv_nsec = 0;
 188 #else
 189   /* Birth time is not supported.  */
 190   t.tv_sec = -1;
 191   t.tv_nsec = -1;
 192   /* Avoid a "parameter unused" warning.  */
 193   (void) st;
 194 #endif
 195
 196 #if (defined HAVE_STRUCT_STAT_ST_BIRTHTIMESPEC_TV_NSEC \
 197      || defined HAVE_STRUCT_STAT_ST_BIRTHTIM_TV_NSEC \
 198      || defined HAVE_STRUCT_STAT_ST_BIRTHTIMENSEC)
 199   /* FreeBSD and NetBSD sometimes signal the absence of knowledge by
 200      using zero.  Attempt to work around this problem.  Alas, this can
 201      report failure even for valid time stamps.  Also, NetBSD
 202      sometimes returns junk in the birth time fields; work around this
 203      bug if it is detected.  */
 204   if (! (t.tv_sec && 0 <= t.tv_nsec && t.tv_nsec < 1000000000))
 205     {
 206       t.tv_sec = -1;
 207       t.tv_nsec = -1;
 208     }
 209 #endif
 210
 211   return t;
 212 }
 213
 214 #endif