ladybird/AK/Time.cpp
Diego Iastrubni 18257604eb Lagom: Win32 support baby steps
This is the initial port of Lagom to win32. This will enable developers
to use Lagom as an alternative to vanilla STL/StandardC++Library - which
gives a much richer environment (think QtCore - but modern).

My main incentive - is to have a native Windows Ladybird working.

I am starting with AK, which does not yet fully compile (on mingw). When
AK is compiling (currently fails building StringBuffer.cpp) - I will
continue to LibCore and then the rest of the user space libraries
(excluding the GUI, which will be another different effort).

Most of the code is happily stollen from Andrew Kaster's fork - he
deserves the credit.

Co-authored-by: Andrew Kaster <akaster@serenityos.org>
2022-09-29 17:01:22 +01:00

334 lines
10 KiB
C++

/*
* Copyright (c) 2020, the SerenityOS developers.
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/Checked.h>
#include <AK/Time.h>
// Make a reasonable guess as to which timespec/timeval definition to use.
// It doesn't really matter, since both are identical.
#ifdef KERNEL
# include <Kernel/UnixTypes.h>
#else
# include <sys/time.h>
# include <time.h>
#endif
namespace AK {
int days_in_month(int year, unsigned month)
{
VERIFY(month >= 1 && month <= 12);
if (month == 2)
return is_leap_year(year) ? 29 : 28;
bool is_long_month = (month == 1 || month == 3 || month == 5 || month == 7 || month == 8 || month == 10 || month == 12);
return is_long_month ? 31 : 30;
}
unsigned day_of_week(int year, unsigned month, int day)
{
VERIFY(month >= 1 && month <= 12);
constexpr Array seek_table = { 0, 3, 2, 5, 0, 3, 5, 1, 4, 6, 2, 4 };
if (month < 3)
--year;
return (year + year / 4 - year / 100 + year / 400 + seek_table[month - 1] + day) % 7;
}
Time Time::from_ticks(clock_t ticks, time_t ticks_per_second)
{
auto secs = ticks % ticks_per_second;
i32 nsecs = 1'000'000'000 * (ticks - (ticks_per_second * secs)) / ticks_per_second;
i32 extra_secs = sane_mod(nsecs, 1'000'000'000);
return Time::from_half_sanitized(secs, extra_secs, nsecs);
}
Time Time::from_timespec(const struct timespec& ts)
{
i32 nsecs = ts.tv_nsec;
i32 extra_secs = sane_mod(nsecs, 1'000'000'000);
return Time::from_half_sanitized(ts.tv_sec, extra_secs, nsecs);
}
Time Time::from_timeval(const struct timeval& tv)
{
i32 usecs = tv.tv_usec;
i32 extra_secs = sane_mod(usecs, 1'000'000);
VERIFY(0 <= usecs && usecs < 1'000'000);
return Time::from_half_sanitized(tv.tv_sec, extra_secs, usecs * 1'000);
}
i64 Time::to_truncated_seconds() const
{
VERIFY(m_nanoseconds < 1'000'000'000);
if (m_seconds < 0 && m_nanoseconds) {
// Since m_seconds is negative, adding 1 can't possibly overflow
return m_seconds + 1;
}
return m_seconds;
}
i64 Time::to_truncated_milliseconds() const
{
VERIFY(m_nanoseconds < 1'000'000'000);
Checked<i64> milliseconds((m_seconds < 0) ? m_seconds + 1 : m_seconds);
milliseconds *= 1'000;
milliseconds += m_nanoseconds / 1'000'000;
if (m_seconds < 0) {
if (m_nanoseconds % 1'000'000 != 0) {
// Does not overflow: milliseconds <= 1'999.
milliseconds++;
}
// We dropped one second previously, put it back in now that we have handled the rounding.
milliseconds -= 1'000;
}
if (!milliseconds.has_overflow())
return milliseconds.value();
return m_seconds < 0 ? -0x8000'0000'0000'0000LL : 0x7fff'ffff'ffff'ffffLL;
}
i64 Time::to_truncated_microseconds() const
{
VERIFY(m_nanoseconds < 1'000'000'000);
Checked<i64> microseconds((m_seconds < 0) ? m_seconds + 1 : m_seconds);
microseconds *= 1'000'000;
microseconds += m_nanoseconds / 1'000;
if (m_seconds < 0) {
if (m_nanoseconds % 1'000 != 0) {
// Does not overflow: microseconds <= 1'999'999.
microseconds++;
}
// We dropped one second previously, put it back in now that we have handled the rounding.
microseconds -= 1'000'000;
}
if (!microseconds.has_overflow())
return microseconds.value();
return m_seconds < 0 ? -0x8000'0000'0000'0000LL : 0x7fff'ffff'ffff'ffffLL;
}
i64 Time::to_seconds() const
{
VERIFY(m_nanoseconds < 1'000'000'000);
if (m_seconds >= 0 && m_nanoseconds) {
Checked<i64> seconds(m_seconds);
seconds++;
return seconds.has_overflow() ? 0x7fff'ffff'ffff'ffffLL : seconds.value();
}
return m_seconds;
}
i64 Time::to_milliseconds() const
{
VERIFY(m_nanoseconds < 1'000'000'000);
Checked<i64> milliseconds((m_seconds < 0) ? m_seconds + 1 : m_seconds);
milliseconds *= 1'000;
milliseconds += m_nanoseconds / 1'000'000;
if (m_seconds >= 0 && m_nanoseconds % 1'000'000 != 0)
milliseconds++;
if (m_seconds < 0) {
// We dropped one second previously, put it back in now that we have handled the rounding.
milliseconds -= 1'000;
}
if (!milliseconds.has_overflow())
return milliseconds.value();
return m_seconds < 0 ? -0x8000'0000'0000'0000LL : 0x7fff'ffff'ffff'ffffLL;
}
i64 Time::to_microseconds() const
{
VERIFY(m_nanoseconds < 1'000'000'000);
Checked<i64> microseconds((m_seconds < 0) ? m_seconds + 1 : m_seconds);
microseconds *= 1'000'000;
microseconds += m_nanoseconds / 1'000;
if (m_seconds >= 0 && m_nanoseconds % 1'000 != 0)
microseconds++;
if (m_seconds < 0) {
// We dropped one second previously, put it back in now that we have handled the rounding.
microseconds -= 1'000'000;
}
if (!microseconds.has_overflow())
return microseconds.value();
return m_seconds < 0 ? -0x8000'0000'0000'0000LL : 0x7fff'ffff'ffff'ffffLL;
}
i64 Time::to_nanoseconds() const
{
VERIFY(m_nanoseconds < 1'000'000'000);
Checked<i64> nanoseconds((m_seconds < 0) ? m_seconds + 1 : m_seconds);
nanoseconds *= 1'000'000'000;
nanoseconds += m_nanoseconds;
if (m_seconds < 0) {
// We dropped one second previously, put it back in now that we have handled the rounding.
nanoseconds -= 1'000'000'000;
}
if (!nanoseconds.has_overflow())
return nanoseconds.value();
return m_seconds < 0 ? -0x8000'0000'0000'0000LL : 0x7fff'ffff'ffff'ffffLL;
}
timespec Time::to_timespec() const
{
VERIFY(m_nanoseconds < 1'000'000'000);
return { static_cast<time_t>(m_seconds), static_cast<long>(m_nanoseconds) };
}
timeval Time::to_timeval() const
{
VERIFY(m_nanoseconds < 1'000'000'000);
// This is done because winsock defines tv_sec and tv_usec as long, and Linux64 as long int.
using sec_type = decltype(declval<timeval>().tv_sec);
using usec_type = decltype(declval<timeval>().tv_usec);
return { static_cast<sec_type>(m_seconds), static_cast<usec_type>(m_nanoseconds) / 1000 };
}
Time Time::operator+(Time const& other) const
{
VERIFY(m_nanoseconds < 1'000'000'000);
VERIFY(other.m_nanoseconds < 1'000'000'000);
u32 new_nsecs = m_nanoseconds + other.m_nanoseconds;
u32 extra_secs = new_nsecs / 1'000'000'000;
new_nsecs %= 1'000'000'000;
i64 this_secs = m_seconds;
i64 other_secs = other.m_seconds;
// We would like to just add "this_secs + other_secs + extra_secs".
// However, computing this naively may overflow even though the result is in-bounds.
// Example in 8-bit: (-127) + (-2) + (+1) = (-128), which fits in an i8.
// Example in 8-bit, the other way around: (-2) + (127) + (+1) = 126.
// So we do something more sophisticated:
if (extra_secs) {
VERIFY(extra_secs == 1);
if (this_secs != 0x7fff'ffff'ffff'ffff) {
this_secs += 1;
} else if (other_secs != 0x7fff'ffff'ffff'ffff) {
other_secs += 1;
} else {
/* If *both* are INT64_MAX, then adding them will overflow in any case. */
return Time::max();
}
}
Checked<i64> new_secs { this_secs };
new_secs += other_secs;
if (new_secs.has_overflow()) {
if (other_secs > 0)
return Time::max();
else
return Time::min();
}
return Time { new_secs.value(), new_nsecs };
}
Time& Time::operator+=(Time const& other)
{
*this = *this + other;
return *this;
}
Time Time::operator-(Time const& other) const
{
VERIFY(m_nanoseconds < 1'000'000'000);
VERIFY(other.m_nanoseconds < 1'000'000'000);
if (other.m_nanoseconds)
return *this + Time((i64) ~(u64)other.m_seconds, 1'000'000'000 - other.m_nanoseconds);
if (other.m_seconds != (i64)-0x8000'0000'0000'0000)
return *this + Time(-other.m_seconds, 0);
// Only remaining case: We want to subtract -0x8000'0000'0000'0000 seconds,
// i.e. add a very large number.
if (m_seconds >= 0)
return Time::max();
return Time { (m_seconds + 0x4000'0000'0000'0000) + 0x4000'0000'0000'0000, m_nanoseconds };
}
Time& Time::operator-=(Time const& other)
{
*this = *this - other;
return *this;
}
bool Time::operator<(Time const& other) const
{
return m_seconds < other.m_seconds || (m_seconds == other.m_seconds && m_nanoseconds < other.m_nanoseconds);
}
bool Time::operator<=(Time const& other) const
{
return m_seconds < other.m_seconds || (m_seconds == other.m_seconds && m_nanoseconds <= other.m_nanoseconds);
}
bool Time::operator>(Time const& other) const
{
return m_seconds > other.m_seconds || (m_seconds == other.m_seconds && m_nanoseconds > other.m_nanoseconds);
}
bool Time::operator>=(Time const& other) const
{
return m_seconds > other.m_seconds || (m_seconds == other.m_seconds && m_nanoseconds >= other.m_nanoseconds);
}
Time Time::from_half_sanitized(i64 seconds, i32 extra_seconds, u32 nanoseconds)
{
VERIFY(nanoseconds < 1'000'000'000);
if ((seconds <= 0 && extra_seconds > 0) || (seconds >= 0 && extra_seconds < 0)) {
// Opposite signs mean that we can definitely add them together without fear of overflowing i64:
seconds += extra_seconds;
extra_seconds = 0;
}
// Now the only possible way to become invalid is overflowing i64 towards positive infinity:
if (Checked<i64>::addition_would_overflow<i64, i64>(seconds, extra_seconds)) {
if (seconds < 0) {
return Time::min();
} else {
return Time::max();
}
}
return Time { seconds + extra_seconds, nanoseconds };
}
#ifndef KERNEL
namespace {
static Time now_time_from_clock(clockid_t clock_id)
{
timespec now_spec {};
::clock_gettime(clock_id, &now_spec);
return Time::from_timespec(now_spec);
}
}
Time Time::now_realtime()
{
return now_time_from_clock(CLOCK_REALTIME);
}
Time Time::now_realtime_coarse()
{
return now_time_from_clock(CLOCK_REALTIME_COARSE);
}
Time Time::now_monotonic()
{
return now_time_from_clock(CLOCK_MONOTONIC);
}
Time Time::now_monotonic_coarse()
{
return now_time_from_clock(CLOCK_MONOTONIC_COARSE);
}
#endif
}