static int find_next(const CalendarSpec *spec, struct tm *tm) {
struct tm c;
int r;
assert(spec);
assert(tm);
c = *tm;
for (;;) {
/* Normalize the current date */
mktime(&c);
c.tm_isdst = -1;
c.tm_year += 1900;
r = find_matching_component(spec->year, &c.tm_year);
c.tm_year -= 1900;
if (r > 0) {
c.tm_mon = 0;
c.tm_mday = 1;
c.tm_hour = c.tm_min = c.tm_sec = 0;
}
if (r < 0 || tm_out_of_bounds(&c))
return r;
c.tm_mon += 1;
r = find_matching_component(spec->month, &c.tm_mon);
c.tm_mon -= 1;
if (r > 0) {
c.tm_mday = 1;
c.tm_hour = c.tm_min = c.tm_sec = 0;
}
if (r < 0 || tm_out_of_bounds(&c)) {
c.tm_year ++;
c.tm_mon = 0;
c.tm_mday = 1;
c.tm_hour = c.tm_min = c.tm_sec = 0;
continue;
}
r = find_matching_component(spec->day, &c.tm_mday);
if (r > 0)
c.tm_hour = c.tm_min = c.tm_sec = 0;
if (r < 0 || tm_out_of_bounds(&c)) {
c.tm_mon ++;
c.tm_mday = 1;
c.tm_hour = c.tm_min = c.tm_sec = 0;
continue;
}
if (!matches_weekday(spec->weekdays_bits, &c)) {
c.tm_mday++;
c.tm_hour = c.tm_min = c.tm_sec = 0;
continue;
}
r = find_matching_component(spec->hour, &c.tm_hour);
if (r > 0)
c.tm_min = c.tm_sec = 0;
if (r < 0 || tm_out_of_bounds(&c)) {
c.tm_mday ++;
c.tm_hour = c.tm_min = c.tm_sec = 0;
continue;
}
r = find_matching_component(spec->minute, &c.tm_min);
if (r > 0)
c.tm_sec = 0;
if (r < 0 || tm_out_of_bounds(&c)) {
c.tm_hour ++;
c.tm_min = c.tm_sec = 0;
continue;
}
r = find_matching_component(spec->second, &c.tm_sec);
if (r < 0 || tm_out_of_bounds(&c)) {
c.tm_min ++;
c.tm_sec = 0;
continue;
}
*tm = c;
return 0;
}
}
static int find_next(const CalendarSpec *spec, struct tm *tm, usec_t *usec) {
struct tm c;
int tm_usec;
int r;
assert(spec);
assert(tm);
c = *tm;
tm_usec = *usec;
for (;;) {
/* Normalize the current date */
(void) mktime_or_timegm(&c, spec->utc);
c.tm_isdst = spec->dst;
c.tm_year += 1900;
r = find_matching_component(spec, spec->year, &c, &c.tm_year);
c.tm_year -= 1900;
if (r > 0) {
c.tm_mon = 0;
c.tm_mday = 1;
c.tm_hour = c.tm_min = c.tm_sec = tm_usec = 0;
}
if (r < 0)
return r;
if (tm_out_of_bounds(&c, spec->utc))
return -ENOENT;
c.tm_mon += 1;
r = find_matching_component(spec, spec->month, &c, &c.tm_mon);
c.tm_mon -= 1;
if (r > 0) {
c.tm_mday = 1;
c.tm_hour = c.tm_min = c.tm_sec = tm_usec = 0;
}
if (r < 0 || tm_out_of_bounds(&c, spec->utc)) {
c.tm_year++;
c.tm_mon = 0;
c.tm_mday = 1;
c.tm_hour = c.tm_min = c.tm_sec = tm_usec = 0;
continue;
}
r = find_matching_component(spec, spec->day, &c, &c.tm_mday);
if (r > 0)
c.tm_hour = c.tm_min = c.tm_sec = tm_usec = 0;
if (r < 0 || tm_out_of_bounds(&c, spec->utc)) {
c.tm_mon++;
c.tm_mday = 1;
c.tm_hour = c.tm_min = c.tm_sec = tm_usec = 0;
continue;
}
if (!matches_weekday(spec->weekdays_bits, &c, spec->utc)) {
c.tm_mday++;
c.tm_hour = c.tm_min = c.tm_sec = tm_usec = 0;
continue;
}
r = find_matching_component(spec, spec->hour, &c, &c.tm_hour);
if (r > 0)
c.tm_min = c.tm_sec = tm_usec = 0;
if (r < 0 || tm_out_of_bounds(&c, spec->utc)) {
c.tm_mday++;
c.tm_hour = c.tm_min = c.tm_sec = tm_usec = 0;
continue;
}
r = find_matching_component(spec, spec->minute, &c, &c.tm_min);
if (r > 0)
c.tm_sec = tm_usec = 0;
if (r < 0 || tm_out_of_bounds(&c, spec->utc)) {
c.tm_hour++;
c.tm_min = c.tm_sec = tm_usec = 0;
continue;
}
c.tm_sec = c.tm_sec * USEC_PER_SEC + tm_usec;
r = find_matching_component(spec, spec->microsecond, &c, &c.tm_sec);
tm_usec = c.tm_sec % USEC_PER_SEC;
c.tm_sec /= USEC_PER_SEC;
if (r < 0 || tm_out_of_bounds(&c, spec->utc)) {
c.tm_min++;
c.tm_sec = tm_usec = 0;
continue;
}
*tm = c;
*usec = tm_usec;
return 0;
}
}