Time64_T mktime64(struct TM *input_date) {
struct tm safe_date;
struct TM date;
Time64_T time;
Year year = input_date->tm_year + 1900;
if( date_in_safe_range(input_date, &SYSTEM_MKTIME_MIN, &SYSTEM_MKTIME_MAX) )
{
copy_TM64_to_tm(input_date, &safe_date);
time = (Time64_T)mktime(&safe_date);
/* Correct the possibly out of bound input date */
copy_tm_to_TM64(&safe_date, input_date);
TIME64_TRACE2("mktime64: safe year %ld, %"PRId64" seconds\n", (long)year, time);
return time;
}
/* Have to make the year safe in date else it won't fit in safe_date */
date = *input_date;
date.tm_year = safe_year(year) - 1900;
copy_TM64_to_tm(&date, &safe_date);
time = (Time64_T)mktime(&safe_date);
TIME64_TRACE1("mktime64: %"PRId64" seconds\n", time);
/* Correct the user's possibly out of bound input date */
copy_tm_to_TM64(&safe_date, input_date);
time += seconds_between_years(year, (Year)(safe_date.tm_year + 1900));
TIME64_TRACE1("mktime64 => %"PRId64" seconds\n", time);
return time;
}
static Time64_T seconds_between_years(Year left_year, Year right_year) {
int increment = (left_year > right_year) ? 1 : -1;
Time64_T seconds = 0;
Year cycles;
if( left_year > 2400 ) {
TIME64_TRACE1("year %"PRId64" > 2400\n", left_year);
cycles = (left_year - 2400) / 400;
left_year -= cycles * 400;
seconds += cycles * seconds_in_gregorian_cycle;
}
else if( left_year < 1600 ) {
TIME64_TRACE1("year %"PRId64" < 1600\n", left_year);
cycles = (left_year - 1600) / 400;
left_year += cycles * 400;
seconds += cycles * seconds_in_gregorian_cycle;
}
if (increment > 0) {
TIME64_TRACE2("year %"PRId64" > safe_year %"PRId64"\n", left_year, right_year);
while( left_year != right_year ) {
seconds += length_of_year[IS_LEAP_ABS(right_year)] * 60 * 60 * 24;
right_year++;
}
TIME64_TRACE1("adjust by %"PRId64" days\n", seconds / (60 * 60 * 24));
return seconds;
} else {
TIME64_TRACE2("year %"PRId64" < safe_year %"PRId64"\n", left_year, right_year);
while( left_year != right_year ) {
seconds -= length_of_year[IS_LEAP_ABS(right_year)] * 60 * 60 * 24;
right_year--;
}
TIME64_TRACE1("adjust by %"PRId64" days\n", seconds / (60 * 60 * 24));
return seconds;
}
}
struct TM *localtime64_r (const Time64_T *time, struct TM *local_tm)
{
time_t safe_time;
struct tm safe_date;
struct TM gm_tm;
Year orig_year;
int month_diff;
assert(local_tm != NULL);
/* Use the system localtime() if time_t is small enough */
if( SHOULD_USE_SYSTEM_LOCALTIME(*time) ) {
safe_time = (time_t)*time;
TIME64_TRACE1("Using system localtime for %lld\n", *time);
LOCALTIME_R(&safe_time, &safe_date);
copy_tm_to_TM64(&safe_date, local_tm);
assert(check_tm(local_tm));
return local_tm;
}
if( gmtime64_r(time, &gm_tm) == NULL ) {
TIME64_TRACE1("gmtime64_r returned null for %lld\n", *time);
return NULL;
}
orig_year = gm_tm.tm_year;
if (gm_tm.tm_year > (2037 - 1900) ||
gm_tm.tm_year < (1970 - 1900)
)
{
TIME64_TRACE1("Mapping tm_year %lld to safe_year\n", (Year)gm_tm.tm_year);
gm_tm.tm_year = safe_year((Year)(gm_tm.tm_year + 1900)) - 1900;
}
safe_time = (time_t)timegm64(&gm_tm);
if( LOCALTIME_R(&safe_time, &safe_date) == NULL ) {
TIME64_TRACE1("localtime_r(%d) returned NULL\n", (int)safe_time);
return NULL;
}
copy_tm_to_TM64(&safe_date, local_tm);
local_tm->tm_year = orig_year;
if( local_tm->tm_year != orig_year ) {
TIME64_TRACE2("tm_year overflow: tm_year %lld, orig_year %lld\n",
(Year)local_tm->tm_year, (Year)orig_year);
#ifdef EOVERFLOW
errno = EOVERFLOW;
#endif
return NULL;
}
month_diff = local_tm->tm_mon - gm_tm.tm_mon;
/* When localtime is Dec 31st previous year and
gmtime is Jan 1st next year.
*/
if( month_diff == 11 ) {
local_tm->tm_year--;
}
/* When localtime is Jan 1st, next year and
gmtime is Dec 31st, previous year.
*/
if( month_diff == -11 ) {
local_tm->tm_year++;
}
/* GMT is Jan 1st, xx01 year, but localtime is still Dec 31st
in a non-leap xx00. There is one point in the cycle
we can't account for which the safe xx00 year is a leap
year. So we need to correct for Dec 31st comming out as
the 366th day of the year.
*/
if( !IS_LEAP(local_tm->tm_year) && local_tm->tm_yday == 365 )
local_tm->tm_yday--;
assert(check_tm(local_tm));
return local_tm;
}