incubator-nuttx/libc/time/lib_mktime.c

142 lines
5.2 KiB
C

/****************************************************************************
* libc/time/lib_mktime.c
*
* Copyright (C) 2007, 2009, 2011 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <time.h>
#include <debug.h>
#include <nuttx/time.h>
/****************************************************************************
* Definitions
****************************************************************************/
/****************************************************************************
* Private Type Declarations
****************************************************************************/
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
/****************************************************************************
* Public Constant Data
****************************************************************************/
/****************************************************************************
* Public Variables
****************************************************************************/
/****************************************************************************
* Private Variables
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Function: mktime
*
* Description:
* Time conversion (based on the POSIX API)
*
****************************************************************************/
#ifdef CONFIG_GREGORIAN_TIME
time_t mktime(const struct tm *tp)
{
time_t ret;
time_t jdn;
/* Get the EPOCH-relative julian date from the calendar year,
* month, and date
*/
jdn = clock_calendar2utc(tp->tm_year+1900, tp->tm_mon+1, tp->tm_mday);
sdbg("jdn=%d tm_year=%d tm_mon=%d tm_mday=%d\n",
(int)jdn, tp->tm_year, tp->tm_mon, tp->tm_mday);
/* Return the seconds into the julian day. */
ret = ((jdn*24 + tp->tm_hour)*60 + tp->tm_min)*60 + tp->tm_sec;
sdbg("ret=%d tm_hour=%d tm_min=%d tm_sec=%d\n",
(int)ret, tp->tm_hour, tp->tm_min, tp->tm_sec);
return ret;
}
#else
/* Simple version that only works for dates within a (relatively) small range
* from the epoch. It does not handle earlier days or longer days where leap
* seconds, etc. apply.
*/
time_t mktime(const struct tm *tp)
{
unsigned int days;
/* Years since epoch in units of days (ignoring leap years). */
days = (tp->tm_year - 70) * 365;
/* Add in the extra days for the leap years prior to the current year. */
days += (tp->tm_year - 69) >> 2;
/* Add in the days up to the beginning of this month. */
days += (time_t)clock_daysbeforemonth(tp->tm_mon, clock_isleapyear(tp->tm_year + 1900));
/* Add in the days since the beginning of this month (days are 1-based). */
days += tp->tm_mday - 1;
/* Then convert the seconds and add in hours, minutes, and seconds */
return ((days * 24 + tp->tm_hour) * 60 + tp->tm_min) * 60 + tp->tm_sec;
}
#endif /* CONFIG_GREGORIAN_TIME */