You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
88 lines
1.5 KiB
C++
88 lines
1.5 KiB
C++
// SPDX-License-Identifier: BSD-2-Clause
|
|
// Copyright CM4all GmbH
|
|
// author: Max Kellermann <mk@cm4all.com>
|
|
|
|
#include "Math.hxx"
|
|
#include "Calendar.hxx"
|
|
#include "Convert.hxx"
|
|
|
|
#include <time.h>
|
|
|
|
std::chrono::system_clock::time_point
|
|
PrecedingMidnightLocal(std::chrono::system_clock::time_point t) noexcept
|
|
try {
|
|
auto tm = LocalTime(t);
|
|
tm.tm_sec = 0;
|
|
tm.tm_min = 0;
|
|
tm.tm_hour = 0;
|
|
return MakeTime(tm);
|
|
} catch (...) {
|
|
/* best-effort fallback for this exotic error condition */
|
|
return t;
|
|
}
|
|
|
|
static void
|
|
IncrementMonth(struct tm &tm) noexcept
|
|
{
|
|
++tm.tm_mon;
|
|
|
|
if (tm.tm_mon >= 12) {
|
|
/* roll over to next year */
|
|
tm.tm_mon = 0;
|
|
++tm.tm_year;
|
|
}
|
|
}
|
|
|
|
void
|
|
EndOfMonth(struct tm &tm) noexcept
|
|
{
|
|
tm.tm_sec = 0;
|
|
tm.tm_min = 0;
|
|
tm.tm_hour = 0;
|
|
tm.tm_mday = 1;
|
|
IncrementMonth(tm);
|
|
}
|
|
|
|
void
|
|
IncrementDay(struct tm &tm) noexcept
|
|
{
|
|
const unsigned max_day = DaysInMonth(tm.tm_mon + 1, tm.tm_year + 1900);
|
|
|
|
++tm.tm_mday;
|
|
|
|
if ((unsigned)tm.tm_mday > max_day) {
|
|
/* roll over to next month */
|
|
tm.tm_mday = 1;
|
|
IncrementMonth(tm);
|
|
}
|
|
|
|
++tm.tm_wday;
|
|
if (tm.tm_wday >= 7)
|
|
tm.tm_wday = 0;
|
|
}
|
|
|
|
void
|
|
DecrementDay(struct tm &tm) noexcept
|
|
{
|
|
--tm.tm_mday;
|
|
|
|
if (tm.tm_mday < 1) {
|
|
/* roll over to previous month */
|
|
|
|
--tm.tm_mon;
|
|
if (tm.tm_mon < 0) {
|
|
/* roll over to previous eyar */
|
|
tm.tm_mon = 11;
|
|
--tm.tm_year;
|
|
}
|
|
|
|
const unsigned max_day = DaysInMonth(tm.tm_mon + 1,
|
|
tm.tm_year + 1900);
|
|
tm.tm_mday = max_day;
|
|
}
|
|
|
|
--tm.tm_wday;
|
|
if (tm.tm_wday < 0)
|
|
tm.tm_wday = 6;
|
|
}
|