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 LTTNG_HIDDEN
  23 bool locale_supports_utf8(void)
  24 {
  25         return utf8_output_supported;
  26 }
  27
  28 LTTNG_HIDDEN
  29 int timespec_to_ms(struct timespec ts, unsigned long *ms)
  30 {
  31         unsigned long res, remain_ms;
  32
  33         if (ts.tv_sec > ULONG_MAX / MSEC_PER_SEC) {
  34                 errno = EOVERFLOW;
  35                 return -1;      /* multiplication overflow */
  36         }
  37         res = ts.tv_sec * MSEC_PER_SEC;
  38         remain_ms = ULONG_MAX - res;
  39         if (ts.tv_nsec / NSEC_PER_MSEC > remain_ms) {
  40                 errno = EOVERFLOW;
  41                 return -1;      /* addition overflow */
  42         }
  43         res += ts.tv_nsec / NSEC_PER_MSEC;
  44         *ms = res;
  45         return 0;
  46 }
  47
  48 LTTNG_HIDDEN
  49 struct timespec timespec_abs_diff(struct timespec t1, struct timespec t2)
  50 {
  51         uint64_t ts1 = (uint64_t) t1.tv_sec * (uint64_t) NSEC_PER_SEC +
  52                         (uint64_t) t1.tv_nsec;
  53         uint64_t ts2 = (uint64_t) t2.tv_sec * (uint64_t) NSEC_PER_SEC +
  54                         (uint64_t) t2.tv_nsec;
  55         uint64_t diff = max(ts1, ts2) - min(ts1, ts2);
  56         struct timespec res;
  57
  58         res.tv_sec = diff / (uint64_t) NSEC_PER_SEC;
  59         res.tv_nsec = diff % (uint64_t) NSEC_PER_SEC;
  60         return res;
  61 }
  62
  63 static
  64 void __attribute__((constructor)) init_locale_utf8_support(void)
  65 {
  66         const char *program_locale = setlocale(LC_ALL, NULL);
  67         const char *lang = getenv("LANG");
  68
  69         if (program_locale && strstr(program_locale, "utf8")) {
  70                 utf8_output_supported = true;
  71         } else if (lang && strstr(lang, "utf8")) {
  72                 utf8_output_supported = true;
  73         }
  74 }
  75
  76 LTTNG_HIDDEN
  77 int time_to_iso8601_str(time_t time, char *str, size_t len)
  78 {
  79         int ret = 0;
  80         struct tm *tm_result;
  81         struct tm tm_storage;
  82         size_t strf_ret;
  83
  84         if (len < ISO8601_STR_LEN) {
  85                 ERR("Buffer too short to format ISO 8601 timestamp: %zu bytes provided when at least %zu are needed",
  86                                 len, ISO8601_STR_LEN);
  87                 ret = -1;
  88                 goto end;
  89         }
  90
  91         tm_result = localtime_r(&time, &tm_storage);
  92         if (!tm_result) {
  93                 ret = -1;
  94                 PERROR("Failed to break down timestamp to tm structure");
  95                 goto end;
  96         }
  97
  98         strf_ret = strftime(str, len, "%Y%m%dT%H%M%S%z", tm_result);
  99         if (strf_ret == 0) {
 100                 ret = -1;
 101                 ERR("Failed to format timestamp as local time");
 102                 goto end;
 103         }
 104 end:
 105         return ret;
 106 }
 107
 108 LTTNG_HIDDEN
 109 int time_to_datetime_str(time_t time, char *str, size_t len)
 110 {
 111         int ret = 0;
 112         struct tm *tm_result;
 113         struct tm tm_storage;
 114         size_t strf_ret;
 115
 116         if (len < DATETIME_STR_LEN) {
 117                 ERR("Buffer too short to format to datetime: %zu bytes provided when at least %zu are needed",
 118                                 len, DATETIME_STR_LEN);
 119                 ret = -1;
 120                 goto end;
 121         }
 122
 123         tm_result = localtime_r(&time, &tm_storage);
 124         if (!tm_result) {
 125                 ret = -1;
 126                 PERROR("Failed to break down timestamp to tm structure");
 127                 goto end;
 128         }
 129
 130         strf_ret = strftime(str, len, "%Y%m%d-%H%M%S", tm_result);
 131         if (strf_ret == 0) {
 132                 ret = -1;
 133                 ERR("Failed to format timestamp as local time");
 134                 goto end;
 135         }
 136 end:
 137         return ret;
 138 }