src/common/time.c

   1 /*
   2  * Copyright (C) 2013 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License, version 2 only, as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc., 51
  15  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  16  */
  17
  18 #include <common/time.h>
  19 #include <common/error.h>
  20 #include <common/macros.h>
  21 #include <stddef.h>
  22 #include <stdint.h>
  23 #include <limits.h>
  24 #include <errno.h>
  25 #include <pthread.h>
  26 #include <locale.h>
  27 #include <string.h>
  28
  29 static bool utf8_output_supported;
  30
  31 LTTNG_HIDDEN
  32 bool locale_supports_utf8(void)
  33 {
  34         return utf8_output_supported;
  35 }
  36
  37 LTTNG_HIDDEN
  38 int timespec_to_ms(struct timespec ts, unsigned long *ms)
  39 {
  40         unsigned long res, remain_ms;
  41
  42         if (ts.tv_sec > ULONG_MAX / MSEC_PER_SEC) {
  43                 errno = EOVERFLOW;
  44                 return -1;      /* multiplication overflow */
  45         }
  46         res = ts.tv_sec * MSEC_PER_SEC;
  47         remain_ms = ULONG_MAX - res;
  48         if (ts.tv_nsec / NSEC_PER_MSEC > remain_ms) {
  49                 errno = EOVERFLOW;
  50                 return -1;      /* addition overflow */
  51         }
  52         res += ts.tv_nsec / NSEC_PER_MSEC;
  53         *ms = res;
  54         return 0;
  55 }
  56
  57 LTTNG_HIDDEN
  58 struct timespec timespec_abs_diff(struct timespec t1, struct timespec t2)
  59 {
  60         uint64_t ts1 = (uint64_t) t1.tv_sec * (uint64_t) NSEC_PER_SEC +
  61                         (uint64_t) t1.tv_nsec;
  62         uint64_t ts2 = (uint64_t) t2.tv_sec * (uint64_t) NSEC_PER_SEC +
  63                         (uint64_t) t2.tv_nsec;
  64         uint64_t diff = max(ts1, ts2) - min(ts1, ts2);
  65         struct timespec res;
  66
  67         res.tv_sec = diff / (uint64_t) NSEC_PER_SEC;
  68         res.tv_nsec = diff % (uint64_t) NSEC_PER_SEC;
  69         return res;
  70 }
  71
  72 LTTNG_HIDDEN
  73 int time_t_to_ISO8601(char *dest, size_t dest_size, time_t time)
  74 {
  75         int ret;
  76         struct tm tm, *timeinfo;
  77
  78         if (dest_size < ISO8601_LEN) {
  79                 ERR("Failed to format time to ISO8601 destination too small");
  80                 ret = -1;
  81                 goto end;
  82         }
  83
  84         timeinfo = localtime_r(&time, &tm);
  85         if (!timeinfo) {
  86                 PERROR("localtime");
  87                 ret = -1;
  88                 goto end;
  89         }
  90
  91         ret = strftime(dest, dest_size, ISO8601_FORMAT, timeinfo);
  92         if (ret == 0) {
  93                 ERR("Failed to format time to ISO8601");
  94                 ret = -1;
  95                 goto end;
  96         }
  97
  98         ret = 0;
  99 end:
 100         return ret;
 101 }
 102
 103 static
 104 void __attribute__((constructor)) init_locale_utf8_support(void)
 105 {
 106         const char *program_locale = setlocale(LC_ALL, NULL);
 107         const char *lang = getenv("LANG");
 108
 109         if (program_locale && strstr(program_locale, "utf8")) {
 110                 utf8_output_supported = true;
 111         } else if (lang && strstr(lang, "utf8")) {
 112                 utf8_output_supported = true;
 113         }
 114 }