/*
* Converts a datetimestruct in UTC to a datetimestruct in local time,
* also returning the timezone offset applied.
*
* Returns 0 on success, -1 on failure.
*/
static int
convert_datetimestruct_utc_to_local(pandas_datetimestruct *out_dts_local,
const pandas_datetimestruct *dts_utc, int *out_timezone_offset)
{
NPY_TIME_T rawtime = 0, localrawtime;
struct tm tm_;
npy_int64 year_correction = 0;
/* Make a copy of the input 'dts' to modify */
*out_dts_local = *dts_utc;
/* HACK: Use a year < 2038 for later years for small time_t */
if (sizeof(NPY_TIME_T) == 4 && out_dts_local->year >= 2038) {
if (is_leapyear(out_dts_local->year)) {
/* 2036 is a leap year */
year_correction = out_dts_local->year - 2036;
out_dts_local->year -= year_correction;
}
else {
/* 2037 is not a leap year */
year_correction = out_dts_local->year - 2037;
out_dts_local->year -= year_correction;
}
}
/*
* Convert everything in 'dts' to a time_t, to minutes precision.
* This is POSIX time, which skips leap-seconds, but because
* we drop the seconds value from the pandas_datetimestruct, everything
* is ok for this operation.
*/
rawtime = (time_t)get_datetimestruct_days(out_dts_local) * 24 * 60 * 60;
rawtime += dts_utc->hour * 60 * 60;
rawtime += dts_utc->min * 60;
/* localtime converts a 'time_t' into a local 'struct tm' */
if (get_localtime(&rawtime, &tm_) < 0) {
return -1;
}
/* Copy back all the values except seconds */
out_dts_local->min = tm_.tm_min;
out_dts_local->hour = tm_.tm_hour;
out_dts_local->day = tm_.tm_mday;
out_dts_local->month = tm_.tm_mon + 1;
out_dts_local->year = tm_.tm_year + 1900;
/* Extract the timezone offset that was applied */
rawtime /= 60;
localrawtime = (time_t)get_datetimestruct_days(out_dts_local) * 24 * 60;
localrawtime += out_dts_local->hour * 60;
localrawtime += out_dts_local->min;
*out_timezone_offset = localrawtime - rawtime;
/* Reapply the year 2038 year correction HACK */
out_dts_local->year += year_correction;
return 0;
}
/*
* Converts a datetime from a datetimestruct to a datetime based
* on some metadata. The date is assumed to be valid.
*
* TODO: If meta->num is really big, there could be overflow
*
* Returns 0 on success, -1 on failure.
*/
int convert_datetimestruct_to_datetime(pandas_datetime_metadata *meta,
const pandas_datetimestruct *dts,
npy_datetime *out) {
npy_datetime ret;
PANDAS_DATETIMEUNIT base = meta->base;
if (base == PANDAS_FR_Y) {
/* Truncate to the year */
ret = dts->year - 1970;
} else if (base == PANDAS_FR_M) {
/* Truncate to the month */
ret = 12 * (dts->year - 1970) + (dts->month - 1);
} else {
/* Otherwise calculate the number of days to start */
npy_int64 days = get_datetimestruct_days(dts);
switch (base) {
case PANDAS_FR_W:
/* Truncate to weeks */
if (days >= 0) {
ret = days / 7;
} else {
ret = (days - 6) / 7;
}
break;
case PANDAS_FR_D:
ret = days;
break;
case PANDAS_FR_h:
ret = days * 24 + dts->hour;
break;
case PANDAS_FR_m:
ret = (days * 24 + dts->hour) * 60 + dts->min;
break;
case PANDAS_FR_s:
ret = ((days * 24 + dts->hour) * 60 + dts->min) * 60 + dts->sec;
break;
case PANDAS_FR_ms:
ret = (((days * 24 + dts->hour) * 60 + dts->min) * 60 +
dts->sec) *
1000 +
dts->us / 1000;
break;
case PANDAS_FR_us:
ret = (((days * 24 + dts->hour) * 60 + dts->min) * 60 +
dts->sec) *
1000000 +
dts->us;
break;
case PANDAS_FR_ns:
ret = ((((days * 24 + dts->hour) * 60 + dts->min) * 60 +
dts->sec) *
1000000 +
dts->us) *
1000 +
dts->ps / 1000;
break;
case PANDAS_FR_ps:
ret = ((((days * 24 + dts->hour) * 60 + dts->min) * 60 +
dts->sec) *
1000000 +
dts->us) *
1000000 +
dts->ps;
break;
case PANDAS_FR_fs:
/* only 2.6 hours */
ret = (((((days * 24 + dts->hour) * 60 + dts->min) * 60 +
dts->sec) *
1000000 +
dts->us) *
1000000 +
dts->ps) *
1000 +
dts->as / 1000;
break;
case PANDAS_FR_as:
/* only 9.2 secs */
ret = (((((days * 24 + dts->hour) * 60 + dts->min) * 60 +
dts->sec) *
1000000 +
dts->us) *
1000000 +
dts->ps) *
1000000 +
dts->as;
break;
default:
/* Something got corrupted */
PyErr_SetString(
PyExc_ValueError,
"NumPy datetime metadata with corrupt unit value");
return -1;
}
}
/* Divide by the multiplier */
if (meta->num > 1) {
if (ret >= 0) {
ret /= meta->num;
} else {
ret = (ret - meta->num + 1) / meta->num;
}
}
*out = ret;
return 0;
}
