src/common/time.cpp

   1 /*
   2  * Copyright (C) 2013 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   3  *
   4  * SPDX-License-Identifier: LGPL-2.1-only
   5  *
   6  */
   7
   8 #include <common/time.hpp>
   9 #include <common/error.hpp>
  10 #include <common/macros.hpp>
  11 #include <common/error.hpp>
  12 #include <common/compat/errno.hpp>
  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 #include <algorithm>
  20
  21 static bool utf8_output_supported;
  22
  23 bool locale_supports_utf8(void)
  24 {
  25         return utf8_output_supported;
  26 }
  27
  28 int timespec_to_ms(struct timespec ts, unsigned long *ms)
  29 {
  30         unsigned long res, remain_ms;
  31
  32         if (ts.tv_sec > ULONG_MAX / MSEC_PER_SEC) {
  33                 errno = EOVERFLOW;
  34                 return -1;      /* multiplication overflow */
  35         }
  36         res = ts.tv_sec * MSEC_PER_SEC;
  37         remain_ms = ULONG_MAX - res;
  38         if (ts.tv_nsec / NSEC_PER_MSEC > remain_ms) {
  39                 errno = EOVERFLOW;
  40                 return -1;      /* addition overflow */
  41         }
  42         res += ts.tv_nsec / NSEC_PER_MSEC;
  43         *ms = res;
  44         return 0;
  45 }
  46
  47 struct timespec timespec_abs_diff(struct timespec t1, struct timespec t2)
  48 {
  49         uint64_t ts1 = (uint64_t) t1.tv_sec * (uint64_t) NSEC_PER_SEC +
  50                         (uint64_t) t1.tv_nsec;
  51         uint64_t ts2 = (uint64_t) t2.tv_sec * (uint64_t) NSEC_PER_SEC +
  52                         (uint64_t) t2.tv_nsec;
  53         uint64_t diff = std::max(ts1, ts2) - std::min(ts1, ts2);
  54         struct timespec res;
  55
  56         res.tv_sec = diff / (uint64_t) NSEC_PER_SEC;
  57         res.tv_nsec = diff % (uint64_t) NSEC_PER_SEC;
  58         return res;
  59 }
  60
  61 static
  62 void __attribute__((constructor)) init_locale_utf8_support(void)
  63 {
  64         const char *program_locale = setlocale(LC_ALL, NULL);
  65         const char *lang = getenv("LANG");
  66
  67         if (program_locale && strstr(program_locale, "utf8")) {
  68                 utf8_output_supported = true;
  69         } else if (lang && strstr(lang, "utf8")) {
  70                 utf8_output_supported = true;
  71         }
  72 }
  73
  74 int time_to_iso8601_str(time_t time, char *str, size_t len)
  75 {
  76         int ret = 0;
  77         struct tm *tm_result;
  78         struct tm tm_storage;
  79         size_t strf_ret;
  80
  81         if (len < ISO8601_STR_LEN) {
  82                 ERR("Buffer too short to format ISO 8601 timestamp: %zu bytes provided when at least %zu are needed",
  83                                 len, ISO8601_STR_LEN);
  84                 ret = -1;
  85                 goto end;
  86         }
  87
  88         tm_result = localtime_r(&time, &tm_storage);
  89         if (!tm_result) {
  90                 ret = -1;
  91                 PERROR("Failed to break down timestamp to tm structure");
  92                 goto end;
  93         }
  94
  95         strf_ret = strftime(str, len, "%Y%m%dT%H%M%S%z", tm_result);
  96         if (strf_ret == 0) {
  97                 ret = -1;
  98                 ERR("Failed to format timestamp as local time");
  99                 goto end;
 100         }
 101 end:
 102         return ret;
 103 }
 104
 105 int time_to_datetime_str(time_t time, char *str, size_t len)
 106 {
 107         int ret = 0;
 108         struct tm *tm_result;
 109         struct tm tm_storage;
 110         size_t strf_ret;
 111
 112         if (len < DATETIME_STR_LEN) {
 113                 ERR("Buffer too short to format to datetime: %zu bytes provided when at least %zu are needed",
 114                                 len, DATETIME_STR_LEN);
 115                 ret = -1;
 116                 goto end;
 117         }
 118
 119         tm_result = localtime_r(&time, &tm_storage);
 120         if (!tm_result) {
 121                 ret = -1;
 122                 PERROR("Failed to break down timestamp to tm structure");
 123                 goto end;
 124         }
 125
 126         strf_ret = strftime(str, len, "%Y%m%d-%H%M%S", tm_result);
 127         if (strf_ret == 0) {
 128                 ret = -1;
 129                 ERR("Failed to format timestamp as local time");
 130                 goto end;
 131         }
 132 end:
 133         return ret;
 134 }