mbed official / mbed-dev

mbed library sources. Supersedes mbed-src.

Dependents:   Nucleo_Hello_Encoder BLE_iBeaconScan AM1805_DEMO DISCO-F429ZI_ExportTemplate1 ... more

platform/mbed_mktime.c@187:0387e8f68319, 2018-09-06 (annotated)

Committer:
AnnaBridge
Date:
Thu Sep 06 13:40:20 2018 +0100
Revision:
187:0387e8f68319
Parent:
184:08ed48f1de7f
Child:
189:f392fc9709a3
mbed-dev library. Release version 163

Who changed what in which revision?

UserRevisionLine numberNew contents of line
AnnaBridge 167:e84263d55307 1 /* mbed Microcontroller Library
AnnaBridge 167:e84263d55307 2 * Copyright (c) 2017-2017 ARM Limited
AnnaBridge 167:e84263d55307 3 *
AnnaBridge 167:e84263d55307 4 * Licensed under the Apache License, Version 2.0 (the "License");
AnnaBridge 167:e84263d55307 5 * you may not use this file except in compliance with the License.
AnnaBridge 167:e84263d55307 6 * You may obtain a copy of the License at
AnnaBridge 167:e84263d55307 7 *
AnnaBridge 167:e84263d55307 8 * http://www.apache.org/licenses/LICENSE-2.0
AnnaBridge 167:e84263d55307 9 *
AnnaBridge 167:e84263d55307 10 * Unless required by applicable law or agreed to in writing, software
AnnaBridge 167:e84263d55307 11 * distributed under the License is distributed on an "AS IS" BASIS,
AnnaBridge 167:e84263d55307 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
AnnaBridge 167:e84263d55307 13 * See the License for the specific language governing permissions and
AnnaBridge 167:e84263d55307 14 * limitations under the License.
AnnaBridge 167:e84263d55307 15 */
AnnaBridge 167:e84263d55307 16
AnnaBridge 167:e84263d55307 17 #include "mbed_mktime.h"
AnnaBridge 167:e84263d55307 18
AnnaBridge 184:08ed48f1de7f 19 /* Time constants. */
AnnaBridge 167:e84263d55307 20 #define SECONDS_BY_MINUTES 60
AnnaBridge 167:e84263d55307 21 #define MINUTES_BY_HOUR 60
AnnaBridge 167:e84263d55307 22 #define SECONDS_BY_HOUR (SECONDS_BY_MINUTES * MINUTES_BY_HOUR)
AnnaBridge 187:0387e8f68319 23 #define HOURS_BY_DAY 24
AnnaBridge 167:e84263d55307 24 #define SECONDS_BY_DAY (SECONDS_BY_HOUR * HOURS_BY_DAY)
AnnaBridge 184:08ed48f1de7f 25 #define LAST_VALID_YEAR 206
AnnaBridge 184:08ed48f1de7f 26
AnnaBridge 184:08ed48f1de7f 27 /* Macros which will be used to determine if we are within valid range. */
AnnaBridge 184:08ed48f1de7f 28 #define EDGE_TIMESTAMP_FULL_LEAP_YEAR_SUPPORT 3220095 // 7th of February 1970 at 06:28:15
AnnaBridge 184:08ed48f1de7f 29 #define EDGE_TIMESTAMP_4_YEAR_LEAP_YEAR_SUPPORT 3133695 // 6th of February 1970 at 06:28:15
AnnaBridge 167:e84263d55307 30
AnnaBridge 167:e84263d55307 31 /*
AnnaBridge 187:0387e8f68319 32 * 2 dimensional array containing the number of seconds elapsed before a given
AnnaBridge 167:e84263d55307 33 * month.
AnnaBridge 167:e84263d55307 34 * The second index map to the month while the first map to the type of year:
AnnaBridge 187:0387e8f68319 35 * - 0: non leap year
AnnaBridge 167:e84263d55307 36 * - 1: leap year
AnnaBridge 167:e84263d55307 37 */
AnnaBridge 167:e84263d55307 38 static const uint32_t seconds_before_month[2][12] = {
AnnaBridge 167:e84263d55307 39 {
AnnaBridge 167:e84263d55307 40 0,
AnnaBridge 167:e84263d55307 41 31 * SECONDS_BY_DAY,
AnnaBridge 187:0387e8f68319 42 (31 + 28) *SECONDS_BY_DAY,
AnnaBridge 187:0387e8f68319 43 (31 + 28 + 31) *SECONDS_BY_DAY,
AnnaBridge 187:0387e8f68319 44 (31 + 28 + 31 + 30) *SECONDS_BY_DAY,
AnnaBridge 187:0387e8f68319 45 (31 + 28 + 31 + 30 + 31) *SECONDS_BY_DAY,
AnnaBridge 187:0387e8f68319 46 (31 + 28 + 31 + 30 + 31 + 30) *SECONDS_BY_DAY,
AnnaBridge 187:0387e8f68319 47 (31 + 28 + 31 + 30 + 31 + 30 + 31) *SECONDS_BY_DAY,
AnnaBridge 187:0387e8f68319 48 (31 + 28 + 31 + 30 + 31 + 30 + 31 + 31) *SECONDS_BY_DAY,
AnnaBridge 187:0387e8f68319 49 (31 + 28 + 31 + 30 + 31 + 30 + 31 + 31 + 30) *SECONDS_BY_DAY,
AnnaBridge 187:0387e8f68319 50 (31 + 28 + 31 + 30 + 31 + 30 + 31 + 31 + 30 + 31) *SECONDS_BY_DAY,
AnnaBridge 187:0387e8f68319 51 (31 + 28 + 31 + 30 + 31 + 30 + 31 + 31 + 30 + 31 + 30) *SECONDS_BY_DAY,
AnnaBridge 167:e84263d55307 52 },
AnnaBridge 167:e84263d55307 53 {
AnnaBridge 167:e84263d55307 54 0,
AnnaBridge 167:e84263d55307 55 31 * SECONDS_BY_DAY,
AnnaBridge 187:0387e8f68319 56 (31 + 29) *SECONDS_BY_DAY,
AnnaBridge 187:0387e8f68319 57 (31 + 29 + 31) *SECONDS_BY_DAY,
AnnaBridge 187:0387e8f68319 58 (31 + 29 + 31 + 30) *SECONDS_BY_DAY,
AnnaBridge 187:0387e8f68319 59 (31 + 29 + 31 + 30 + 31) *SECONDS_BY_DAY,
AnnaBridge 187:0387e8f68319 60 (31 + 29 + 31 + 30 + 31 + 30) *SECONDS_BY_DAY,
AnnaBridge 187:0387e8f68319 61 (31 + 29 + 31 + 30 + 31 + 30 + 31) *SECONDS_BY_DAY,
AnnaBridge 187:0387e8f68319 62 (31 + 29 + 31 + 30 + 31 + 30 + 31 + 31) *SECONDS_BY_DAY,
AnnaBridge 187:0387e8f68319 63 (31 + 29 + 31 + 30 + 31 + 30 + 31 + 31 + 30) *SECONDS_BY_DAY,
AnnaBridge 187:0387e8f68319 64 (31 + 29 + 31 + 30 + 31 + 30 + 31 + 31 + 30 + 31) *SECONDS_BY_DAY,
AnnaBridge 187:0387e8f68319 65 (31 + 29 + 31 + 30 + 31 + 30 + 31 + 31 + 30 + 31 + 30) *SECONDS_BY_DAY,
AnnaBridge 167:e84263d55307 66 }
AnnaBridge 167:e84263d55307 67 };
AnnaBridge 167:e84263d55307 68
AnnaBridge 187:0387e8f68319 69 bool _rtc_is_leap_year(int year, rtc_leap_year_support_t leap_year_support)
AnnaBridge 187:0387e8f68319 70 {
AnnaBridge 187:0387e8f68319 71 /*
AnnaBridge 187:0387e8f68319 72 * since in practice, the value manipulated by this algorithm lie in the
AnnaBridge 184:08ed48f1de7f 73 * range: [70 : 206] the algorithm can be reduced to: year % 4 with exception for 200 (year 2100 is not leap year).
AnnaBridge 187:0387e8f68319 74 * The algorithm valid over the full range of value is:
AnnaBridge 167:e84263d55307 75
AnnaBridge 167:e84263d55307 76 year = 1900 + year;
AnnaBridge 167:e84263d55307 77 if (year % 4) {
AnnaBridge 167:e84263d55307 78 return false;
AnnaBridge 167:e84263d55307 79 } else if (year % 100) {
AnnaBridge 167:e84263d55307 80 return true;
AnnaBridge 167:e84263d55307 81 } else if (year % 400) {
AnnaBridge 167:e84263d55307 82 return false;
AnnaBridge 167:e84263d55307 83 }
AnnaBridge 167:e84263d55307 84 return true;
AnnaBridge 167:e84263d55307 85
AnnaBridge 187:0387e8f68319 86 */
AnnaBridge 184:08ed48f1de7f 87 if (leap_year_support == RTC_FULL_LEAP_YEAR_SUPPORT && year == 200) {
AnnaBridge 184:08ed48f1de7f 88 return false; // 2100 is not a leap year
AnnaBridge 184:08ed48f1de7f 89 }
AnnaBridge 184:08ed48f1de7f 90
AnnaBridge 167:e84263d55307 91 return (year) % 4 ? false : true;
AnnaBridge 167:e84263d55307 92 }
AnnaBridge 167:e84263d55307 93
AnnaBridge 187:0387e8f68319 94 bool _rtc_maketime(const struct tm *time, time_t *seconds, rtc_leap_year_support_t leap_year_support)
AnnaBridge 187:0387e8f68319 95 {
AnnaBridge 184:08ed48f1de7f 96 if (seconds == NULL || time == NULL) {
AnnaBridge 184:08ed48f1de7f 97 return false;
AnnaBridge 184:08ed48f1de7f 98 }
AnnaBridge 184:08ed48f1de7f 99
AnnaBridge 184:08ed48f1de7f 100 /* Partial check for the upper bound of the range - check years only. Full check will be performed after the
AnnaBridge 184:08ed48f1de7f 101 * elapsed time since the beginning of the year is calculated.
AnnaBridge 184:08ed48f1de7f 102 */
AnnaBridge 184:08ed48f1de7f 103 if ((time->tm_year < 70) || (time->tm_year > LAST_VALID_YEAR)) {
AnnaBridge 184:08ed48f1de7f 104 return false;
AnnaBridge 167:e84263d55307 105 }
AnnaBridge 167:e84263d55307 106
AnnaBridge 167:e84263d55307 107 uint32_t result = time->tm_sec;
AnnaBridge 167:e84263d55307 108 result += time->tm_min * SECONDS_BY_MINUTES;
AnnaBridge 167:e84263d55307 109 result += time->tm_hour * SECONDS_BY_HOUR;
AnnaBridge 167:e84263d55307 110 result += (time->tm_mday - 1) * SECONDS_BY_DAY;
AnnaBridge 184:08ed48f1de7f 111 result += seconds_before_month[_rtc_is_leap_year(time->tm_year, leap_year_support)][time->tm_mon];
AnnaBridge 184:08ed48f1de7f 112
AnnaBridge 184:08ed48f1de7f 113 /* Check if we are within valid range. */
AnnaBridge 184:08ed48f1de7f 114 if (time->tm_year == LAST_VALID_YEAR) {
AnnaBridge 184:08ed48f1de7f 115 if ((leap_year_support == RTC_FULL_LEAP_YEAR_SUPPORT && result > EDGE_TIMESTAMP_FULL_LEAP_YEAR_SUPPORT) ||
AnnaBridge 187:0387e8f68319 116 (leap_year_support == RTC_4_YEAR_LEAP_YEAR_SUPPORT && result > EDGE_TIMESTAMP_4_YEAR_LEAP_YEAR_SUPPORT)) {
AnnaBridge 187:0387e8f68319 117 return false;
AnnaBridge 184:08ed48f1de7f 118 }
AnnaBridge 184:08ed48f1de7f 119 }
AnnaBridge 167:e84263d55307 120
AnnaBridge 187:0387e8f68319 121 if (time->tm_year > 70) {
AnnaBridge 184:08ed48f1de7f 122 /* Valid in the range [70:206]. */
AnnaBridge 167:e84263d55307 123 uint32_t count_of_leap_days = ((time->tm_year - 1) / 4) - (70 / 4);
AnnaBridge 184:08ed48f1de7f 124 if (leap_year_support == RTC_FULL_LEAP_YEAR_SUPPORT) {
AnnaBridge 184:08ed48f1de7f 125 if (time->tm_year > 200) {
AnnaBridge 184:08ed48f1de7f 126 count_of_leap_days--; // 2100 is not a leap year
AnnaBridge 184:08ed48f1de7f 127 }
AnnaBridge 184:08ed48f1de7f 128 }
AnnaBridge 184:08ed48f1de7f 129
AnnaBridge 167:e84263d55307 130 result += (((time->tm_year - 70) * 365) + count_of_leap_days) * SECONDS_BY_DAY;
AnnaBridge 167:e84263d55307 131 }
AnnaBridge 167:e84263d55307 132
AnnaBridge 184:08ed48f1de7f 133 *seconds = result;
AnnaBridge 167:e84263d55307 134
AnnaBridge 184:08ed48f1de7f 135 return true;
AnnaBridge 167:e84263d55307 136 }
AnnaBridge 167:e84263d55307 137
AnnaBridge 187:0387e8f68319 138 bool _rtc_localtime(time_t timestamp, struct tm *time_info, rtc_leap_year_support_t leap_year_support)
AnnaBridge 187:0387e8f68319 139 {
AnnaBridge 184:08ed48f1de7f 140 if (time_info == NULL) {
AnnaBridge 167:e84263d55307 141 return false;
AnnaBridge 184:08ed48f1de7f 142 }
AnnaBridge 184:08ed48f1de7f 143
AnnaBridge 184:08ed48f1de7f 144 uint32_t seconds = (uint32_t)timestamp;
AnnaBridge 167:e84263d55307 145
AnnaBridge 184:08ed48f1de7f 146 time_info->tm_sec = seconds % 60;
AnnaBridge 184:08ed48f1de7f 147 seconds = seconds / 60; // timestamp in minutes
AnnaBridge 184:08ed48f1de7f 148 time_info->tm_min = seconds % 60;
AnnaBridge 184:08ed48f1de7f 149 seconds = seconds / 60; // timestamp in hours
AnnaBridge 184:08ed48f1de7f 150 time_info->tm_hour = seconds % 24;
AnnaBridge 184:08ed48f1de7f 151 seconds = seconds / 24; // timestamp in days;
AnnaBridge 167:e84263d55307 152
AnnaBridge 184:08ed48f1de7f 153 /* Compute the weekday.
AnnaBridge 184:08ed48f1de7f 154 * The 1st of January 1970 was a Thursday which is equal to 4 in the weekday representation ranging from [0:6].
AnnaBridge 184:08ed48f1de7f 155 */
AnnaBridge 184:08ed48f1de7f 156 time_info->tm_wday = (seconds + 4) % 7;
AnnaBridge 167:e84263d55307 157
AnnaBridge 184:08ed48f1de7f 158 /* Years start at 70. */
AnnaBridge 167:e84263d55307 159 time_info->tm_year = 70;
AnnaBridge 187:0387e8f68319 160 while (true) {
AnnaBridge 184:08ed48f1de7f 161 if (_rtc_is_leap_year(time_info->tm_year, leap_year_support) && seconds >= 366) {
AnnaBridge 167:e84263d55307 162 ++time_info->tm_year;
AnnaBridge 184:08ed48f1de7f 163 seconds -= 366;
AnnaBridge 184:08ed48f1de7f 164 } else if (!_rtc_is_leap_year(time_info->tm_year, leap_year_support) && seconds >= 365) {
AnnaBridge 167:e84263d55307 165 ++time_info->tm_year;
AnnaBridge 184:08ed48f1de7f 166 seconds -= 365;
AnnaBridge 167:e84263d55307 167 } else {
AnnaBridge 184:08ed48f1de7f 168 /* The remaining days are less than a years. */
AnnaBridge 167:e84263d55307 169 break;
AnnaBridge 167:e84263d55307 170 }
AnnaBridge 167:e84263d55307 171 }
AnnaBridge 167:e84263d55307 172
AnnaBridge 184:08ed48f1de7f 173 time_info->tm_yday = seconds;
AnnaBridge 167:e84263d55307 174
AnnaBridge 184:08ed48f1de7f 175 /* Convert days into seconds and find the current month. */
AnnaBridge 184:08ed48f1de7f 176 seconds *= SECONDS_BY_DAY;
AnnaBridge 167:e84263d55307 177 time_info->tm_mon = 11;
AnnaBridge 184:08ed48f1de7f 178 bool leap = _rtc_is_leap_year(time_info->tm_year, leap_year_support);
AnnaBridge 167:e84263d55307 179 for (uint32_t i = 0; i < 12; ++i) {
AnnaBridge 184:08ed48f1de7f 180 if ((uint32_t) seconds < seconds_before_month[leap][i]) {
AnnaBridge 167:e84263d55307 181 time_info->tm_mon = i - 1;
AnnaBridge 167:e84263d55307 182 break;
AnnaBridge 167:e84263d55307 183 }
AnnaBridge 167:e84263d55307 184 }
AnnaBridge 167:e84263d55307 185
AnnaBridge 184:08ed48f1de7f 186 /* Remove month from timestamp and compute the number of days.
AnnaBridge 184:08ed48f1de7f 187 * Note: unlike other fields, days are not 0 indexed.
AnnaBridge 184:08ed48f1de7f 188 */
AnnaBridge 184:08ed48f1de7f 189 seconds -= seconds_before_month[leap][time_info->tm_mon];
AnnaBridge 184:08ed48f1de7f 190 time_info->tm_mday = (seconds / SECONDS_BY_DAY) + 1;
AnnaBridge 167:e84263d55307 191
AnnaBridge 167:e84263d55307 192 return true;
AnnaBridge 167:e84263d55307 193 }