micropython/lib/timeutils/timeutils.h

/*
 * This file is part of the MicroPython project, http://micropython.org/
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 2013, 2014 Damien P. George
 * Copyright (c) 2015 Daniel Campora
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
#ifndef MICROPY_INCLUDED_LIB_TIMEUTILS_TIMEUTILS_H
#define MICROPY_INCLUDED_LIB_TIMEUTILS_TIMEUTILS_H

// The number of seconds between 1970/1/1 and 2000/1/1 is calculated using:
// time.mktime((2000,1,1,0,0,0,0,0,0)) - time.mktime((1970,1,1,0,0,0,0,0,0))
#define TIMEUTILS_SECONDS_1970_TO_2000 (946684800ULL)

typedef struct _timeutils_struct_time_t {
    uint16_t tm_year;       // i.e. 2014
    uint8_t tm_mon;         // 1..12
    uint8_t tm_mday;        // 1..31
    uint8_t tm_hour;        // 0..23
    uint8_t tm_min;         // 0..59
    uint8_t tm_sec;         // 0..59
    uint8_t tm_wday;        // 0..6  0 = Monday
    uint16_t tm_yday;       // 1..366
} timeutils_struct_time_t;

bool timeutils_is_leap_year(mp_uint_t year);
mp_uint_t timeutils_days_in_month(mp_uint_t year, mp_uint_t month);
mp_uint_t timeutils_year_day(mp_uint_t year, mp_uint_t month, mp_uint_t date);

void timeutils_seconds_since_2000_to_struct_time(mp_uint_t t,
    timeutils_struct_time_t *tm);

mp_uint_t timeutils_seconds_since_2000(mp_uint_t year, mp_uint_t month,
    mp_uint_t date, mp_uint_t hour, mp_uint_t minute, mp_uint_t second);

mp_uint_t timeutils_mktime_2000(mp_uint_t year, mp_int_t month, mp_int_t mday,
    mp_int_t hours, mp_int_t minutes, mp_int_t seconds);

// Select the Epoch used by the port.
#if MICROPY_EPOCH_IS_1970

static inline void timeutils_seconds_since_epoch_to_struct_time(uint64_t t, timeutils_struct_time_t *tm) {
    // TODO this will give incorrect results for dates before 2000/1/1
    return timeutils_seconds_since_2000_to_struct_time(t - TIMEUTILS_SECONDS_1970_TO_2000, tm);
}

static inline uint64_t timeutils_mktime(mp_uint_t year, mp_int_t month, mp_int_t mday, mp_int_t hours, mp_int_t minutes, mp_int_t seconds) {
    return timeutils_mktime_2000(year, month, mday, hours, minutes, seconds) + TIMEUTILS_SECONDS_1970_TO_2000;
}

static inline uint64_t timeutils_seconds_since_epoch(mp_uint_t year, mp_uint_t month,
    mp_uint_t date, mp_uint_t hour, mp_uint_t minute, mp_uint_t second) {
    return timeutils_seconds_since_2000(year, month, date, hour, minute, second) + TIMEUTILS_SECONDS_1970_TO_2000;
}

static inline mp_uint_t timeutils_seconds_since_epoch_from_nanoseconds_since_1970(uint64_t ns) {
    return ns / 1000000000ULL;
}

static inline uint64_t timeutils_nanoseconds_since_epoch_to_nanoseconds_since_1970(uint64_t ns) {
    return ns;
}

#else // Epoch is 2000

#define timeutils_seconds_since_epoch_to_struct_time timeutils_seconds_since_2000_to_struct_time
#define timeutils_seconds_since_epoch timeutils_seconds_since_2000
#define timeutils_mktime timeutils_mktime_2000

static inline uint64_t timeutils_seconds_since_epoch_to_nanoseconds_since_1970(mp_uint_t s) {
    return ((uint64_t)s + TIMEUTILS_SECONDS_1970_TO_2000) * 1000000000ULL;
}

static inline mp_uint_t timeutils_seconds_since_epoch_from_nanoseconds_since_1970(uint64_t ns) {
    return ns / 1000000000ULL - TIMEUTILS_SECONDS_1970_TO_2000;
}

static inline int64_t timeutils_nanoseconds_since_epoch_to_nanoseconds_since_1970(int64_t ns) {
    return ns + TIMEUTILS_SECONDS_1970_TO_2000 * 1000000000ULL;
}

#endif

#endif // MICROPY_INCLUDED_LIB_TIMEUTILS_TIMEUTILS_H