src/common/time.c

   1 /*
   2  * Copyright (C) 2013 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   3  *
   4  * SPDX-License-Identifier: GPL-2.0-only
   5  *
   6  */
   7
   8 #include <common/time.h>
   9 #include <common/error.h>
  10 #include <common/macros.h>
  11 #include <common/error.h>
  12 #include <common/compat/errno.h>
  13 #include <stddef.h>
  14 #include <stdint.h>
  15 #include <limits.h>
  16 #include <pthread.h>
  17 #include <locale.h>
  18 #include <string.h>
  19
  20 static bool utf8_output_supported;
  21
  22 bool locale_supports_utf8(void)
  23 {
  24         return utf8_output_supported;
  25 }
  26
  27 int timespec_to_ms(struct timespec ts, unsigned long *ms)
  28 {
  29         unsigned long res, remain_ms;
  30
  31         if (ts.tv_sec > ULONG_MAX / MSEC_PER_SEC) {
  32                 errno = EOVERFLOW;
  33                 return -1;      /* multiplication overflow */
  34         }
  35         res = ts.tv_sec * MSEC_PER_SEC;
  36         remain_ms = ULONG_MAX - res;
  37         if (ts.tv_nsec / NSEC_PER_MSEC > remain_ms) {
  38                 errno = EOVERFLOW;
  39                 return -1;      /* addition overflow */
  40         }
  41         res += ts.tv_nsec / NSEC_PER_MSEC;
  42         *ms = res;
  43         return 0;
  44 }
  45
  46 struct timespec timespec_abs_diff(struct timespec t1, struct timespec t2)
  47 {
  48         uint64_t ts1 = (uint64_t) t1.tv_sec * (uint64_t) NSEC_PER_SEC +
  49                         (uint64_t) t1.tv_nsec;
  50         uint64_t ts2 = (uint64_t) t2.tv_sec * (uint64_t) NSEC_PER_SEC +
  51                         (uint64_t) t2.tv_nsec;
  52         uint64_t diff = max(ts1, ts2) - min(ts1, ts2);
  53         struct timespec res;
  54
  55         res.tv_sec = diff / (uint64_t) NSEC_PER_SEC;
  56         res.tv_nsec = diff % (uint64_t) NSEC_PER_SEC;
  57         return res;
  58 }
  59
  60 static
  61 void __attribute__((constructor)) init_locale_utf8_support(void)
  62 {
  63         const char *program_locale = setlocale(LC_ALL, NULL);
  64         const char *lang = getenv("LANG");
  65
  66         if (program_locale && strstr(program_locale, "utf8")) {
  67                 utf8_output_supported = true;
  68         } else if (lang && strstr(lang, "utf8")) {
  69                 utf8_output_supported = true;
  70         }
  71 }
  72
  73 int time_to_iso8601_str(time_t time, char *str, size_t len)
  74 {
  75         int ret = 0;
  76         struct tm *tm_result;
  77         struct tm tm_storage;
  78         size_t strf_ret;
  79
  80         if (len < ISO8601_STR_LEN) {
  81                 ERR("Buffer too short to format ISO 8601 timestamp: %zu bytes provided when at least %zu are needed",
  82                                 len, ISO8601_STR_LEN);
  83                 ret = -1;
  84                 goto end;
  85         }
  86
  87         tm_result = localtime_r(&time, &tm_storage);
  88         if (!tm_result) {
  89                 ret = -1;
  90                 PERROR("Failed to break down timestamp to tm structure");
  91                 goto end;
  92         }
  93
  94         strf_ret = strftime(str, len, "%Y%m%dT%H%M%S%z", tm_result);
  95         if (strf_ret == 0) {
  96                 ret = -1;
  97                 ERR("Failed to format timestamp as local time");
  98                 goto end;
  99         }
 100 end:
 101         return ret;
 102 }
 103
 104 int time_to_datetime_str(time_t time, char *str, size_t len)
 105 {
 106         int ret = 0;
 107         struct tm *tm_result;
 108         struct tm tm_storage;
 109         size_t strf_ret;
 110
 111         if (len < DATETIME_STR_LEN) {
 112                 ERR("Buffer too short to format to datetime: %zu bytes provided when at least %zu are needed",
 113                                 len, DATETIME_STR_LEN);
 114                 ret = -1;
 115                 goto end;
 116         }
 117
 118         tm_result = localtime_r(&time, &tm_storage);
 119         if (!tm_result) {
 120                 ret = -1;
 121                 PERROR("Failed to break down timestamp to tm structure");
 122                 goto end;
 123         }
 124
 125         strf_ret = strftime(str, len, "%Y%m%d-%H%M%S", tm_result);
 126         if (strf_ret == 0) {
 127                 ret = -1;
 128                 ERR("Failed to format timestamp as local time");
 129                 goto end;
 130         }
 131 end:
 132         return ret;
 133 }