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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: set ts=8 sts=2 et sw=2 tw=80:
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
#ifndef builtin_temporal_TemporalTypes_h
#define builtin_temporal_TemporalTypes_h
#include "mozilla/Assertions.h"
#include "mozilla/CheckedInt.h"
#include <cmath>
#include <stdint.h>
#include <type_traits>
#include <utility>
#include "jstypes.h"
#include "builtin/temporal/Int128.h"
#include "builtin/temporal/TemporalUnit.h"
namespace js::temporal {
// Use __builtin_assume when available, otherwise fall back to
// __builtin_unreachable.
#if defined __has_builtin
# if __has_builtin(__builtin_assume)
# define JS_ASSUME(x) __builtin_assume(x)
# elif __has_builtin(__builtin_unreachable)
# define JS_ASSUME(x) \
if (!(x)) __builtin_unreachable()
# else
# endif
#endif
// Fallback to no-op if neither built-in is available.
#ifndef JS_ASSUME
# define JS_ASSUME(x) \
do { \
} while (false)
#endif
/**
* Struct to represent a seconds and nanoseconds value. The nanoseconds value
* is normalized to the range [0, 999'999'999].
*/
template <typename Derived>
struct SecondsAndNanoseconds {
// Seconds part in the range allowed by the derived class.
int64_t seconds = 0;
// Nanoseconds part in the range [0, 999'999'999].
int32_t nanoseconds = 0;
constexpr bool operator==(const SecondsAndNanoseconds& other) const {
return seconds == other.seconds && nanoseconds == other.nanoseconds;
}
constexpr bool operator<(const SecondsAndNanoseconds& other) const {
// The compiler can optimize expressions like |epochNs < EpochNanoseconds{}|
// to a single right-shift operation when we propagate the range of
// nanoseconds.
JS_ASSUME(nanoseconds >= 0);
JS_ASSUME(other.nanoseconds >= 0);
return (seconds < other.seconds) ||
(seconds == other.seconds && nanoseconds < other.nanoseconds);
}
// Other operators are implemented in terms of operator== and operator<.
constexpr bool operator!=(const SecondsAndNanoseconds& other) const {
return !(*this == other);
}
constexpr bool operator>(const SecondsAndNanoseconds& other) const {
return other < *this;
}
constexpr bool operator<=(const SecondsAndNanoseconds& other) const {
return !(other < *this);
}
constexpr bool operator>=(const SecondsAndNanoseconds& other) const {
return !(*this < other);
}
protected:
template <typename T, typename U, class R = Derived>
static constexpr R add(const SecondsAndNanoseconds<T>& self,
const SecondsAndNanoseconds<U>& other) {
// The caller needs to make sure integer overflow won't happen. CheckedInt
// will assert on overflow and we intentionally don't try to recover from
// overflow in this method.
mozilla::CheckedInt64 secs = self.seconds;
secs += other.seconds;
mozilla::CheckedInt32 nanos = self.nanoseconds;
nanos += other.nanoseconds;
if (nanos.value() >= 1'000'000'000) {
secs += 1;
nanos -= 1'000'000'000;
}
MOZ_ASSERT(0 <= nanos.value() && nanos.value() < 1'000'000'000);
return {{secs.value(), nanos.value()}};
}
template <class T, class U, class R = Derived>
static constexpr R subtract(const SecondsAndNanoseconds<T>& self,
const SecondsAndNanoseconds<U>& other) {
// The caller needs to make sure integer underflow won't happen. CheckedInt
// will assert on underflow and we intentionally don't try to recover from
// underflow in this method.
mozilla::CheckedInt64 secs = self.seconds;
secs -= other.seconds;
mozilla::CheckedInt32 nanos = self.nanoseconds;
nanos -= other.nanoseconds;
if (nanos.value() < 0) {
secs -= 1;
nanos += 1'000'000'000;
}
MOZ_ASSERT(0 <= nanos.value() && nanos.value() < 1'000'000'000);
return {{secs.value(), nanos.value()}};
}
static constexpr Derived negate(const Derived& self) {
return subtract(Derived{}, self);
}
public:
/**
* Denormalize the seconds and nanoseconds components.
*
* Negative nanoseconds are represented as the difference to 1'000'000'000.
* Convert these back to their absolute value and adjust the seconds part
* accordingly.
*
* For example the nanoseconds duration `-1n` is represented as the duration
* `{seconds: -1, nanoseconds: 999'999'999}`.
*/
constexpr std::pair<int64_t, int32_t> denormalize() const {
int64_t sec = seconds;
int32_t nanos = nanoseconds;
if (sec < 0 && nanos > 0) {
sec += 1;
nanos -= 1'000'000'000;
}
return {sec, nanos};
}
/**
* Return the absolute value.
*/
constexpr Derived abs() const {
auto [sec, nanos] = denormalize();
return {{std::abs(sec), std::abs(nanos)}};
}
/**
* Return the 24-hour days value, rounded towards zero.
*/
constexpr int64_t toDays() const {
auto [sec, nanos] = denormalize();
return sec / ToSeconds(TemporalUnit::Day);
}
/**
* Return the milliseconds value, rounded towards zero.
*/
constexpr int64_t toMilliseconds() const {
auto [sec, nanos] = denormalize();
return (sec * 1'000) + (nanos / 1'000'000);
}
/**
* Return the microseconds value, rounded towards zero.
*/
constexpr Int128 toMicroseconds() const {
auto [sec, nanos] = denormalize();
return Int128{sec} * Int128{ToMicroseconds(TemporalUnit::Second)} +
Int128{nanos / 1'000};
}
/**
* Return the nanoseconds value.
*/
constexpr Int128 toNanoseconds() const {
return Int128{seconds} * Int128{ToNanoseconds(TemporalUnit::Second)} +
Int128{nanoseconds};
}
/**
* Cast to a different representation.
*/
template <class Other>
constexpr Other to() const {
static_assert(std::is_base_of_v<SecondsAndNanoseconds<Other>, Other>);
return Other{{seconds, nanoseconds}};
}
/**
* Create from a days value.
*/
static constexpr Derived fromDays(int64_t days) {
return {{days * ToSeconds(TemporalUnit::Day), 0}};
}
/**
* Create from a minutes value.
*/
static constexpr Derived fromMinutes(int64_t minutes) {
return {{minutes * ToSeconds(TemporalUnit::Minute), 0}};
}
/**
* Create from a milliseconds value.
*/
static constexpr Derived fromMilliseconds(int64_t milliseconds) {
int64_t seconds = milliseconds / 1'000;
int32_t millis = int32_t(milliseconds % 1'000);
if (millis < 0) {
seconds -= 1;
millis += 1'000;
}
return {{seconds, millis * 1'000'000}};
}
/**
* Create from a nanoseconds value.
*/
static constexpr Derived fromNanoseconds(int64_t nanoseconds) {
int64_t seconds = nanoseconds / 1'000'000'000;
int32_t nanos = int32_t(nanoseconds % 1'000'000'000);
if (nanos < 0) {
seconds -= 1;
nanos += 1'000'000'000;
}
return {{seconds, nanos}};
}
/**
* Create from a nanoseconds value.
*/
static Derived fromNanoseconds(const Int128& nanoseconds) {
auto div = nanoseconds.divrem(Int128{1'000'000'000});
int64_t seconds = int64_t(div.first);
int32_t nanos = int32_t(div.second);
if (nanos < 0) {
seconds -= 1;
nanos += 1'000'000'000;
}
return {{seconds, nanos}};
}
};
#undef JS_ASSUME
/**
* EpochDuration represents a duration of time between two epoch nanoseconds,
* measured in nanoseconds.
*/
struct EpochDuration final : SecondsAndNanoseconds<EpochDuration> {
constexpr EpochDuration& operator+=(const EpochDuration& other) {
*this = add(*this, other);
return *this;
}
constexpr EpochDuration& operator-=(const EpochDuration& other) {
*this = subtract(*this, other);
return *this;
}
constexpr EpochDuration operator+(const EpochDuration& other) const {
return add(*this, other);
}
constexpr EpochDuration operator-(const EpochDuration& other) const {
return subtract(*this, other);
}
constexpr EpochDuration operator-() const { return negate(*this); }
/**
* Returns the maximum epoch duration value.
*/
static constexpr EpochDuration max() {
// The limit is 2×8.64 × 10^21 nanoseconds, which is 2×8.64 × 10^12 seconds.
constexpr int64_t seconds = 2 * 8'640'000'000'000;
constexpr int64_t nanos = 0;
return {{seconds, nanos}};
}
/**
* Returns the minimum epoch duration value.
*/
static constexpr EpochDuration min() { return -max(); }
};
/**
* EpochNanoseconds represents a time since the epoch value, measured in
* nanoseconds.
*
* EpochNanoseconds supports a range of ±8.64 × 10^21 nanoseconds, covering
* ±10^8 days in either direction relative to midnight at the beginning of
* 1 January 1970 UTC. This matches the range supported by JavaScript Date
* objects.
*
* C++ doesn't provide a built-in type capable of storing an integer in the
* range ±8.64 × 10^21, therefore we need to create our own abstraction. This
* struct follows the design of `std::timespec` and splits the epoch nanoseconds
* into a signed seconds part and an unsigned nanoseconds part.
*/
struct EpochNanoseconds final : SecondsAndNanoseconds<EpochNanoseconds> {
constexpr EpochNanoseconds& operator+=(const EpochDuration& other) {
*this = add(*this, other);
return *this;
}
constexpr EpochNanoseconds& operator-=(const EpochDuration& other) {
*this = subtract(*this, other);
return *this;
}
constexpr EpochNanoseconds operator+(const EpochDuration& other) const {
return add(*this, other);
}
constexpr EpochNanoseconds operator-(const EpochDuration& other) const {
return subtract(*this, other);
}
constexpr EpochDuration operator-(const EpochNanoseconds& other) const {
return subtract<EpochNanoseconds, EpochNanoseconds, EpochDuration>(*this,
other);
}
constexpr EpochNanoseconds operator-() const { return negate(*this); }
/**
* Return this epoch nanoseconds as milliseconds from the start of the epoch.
* (Rounds towards negative infinity.)
*/
constexpr int64_t floorToMilliseconds() const {
return (seconds * 1'000) + (nanoseconds / 1'000'000);
}
/**
* Return this epoch nanoseconds as milliseconds from the start of the epoch.
* (Rounds towards positive infinity.)
*/
constexpr int64_t ceilToMilliseconds() const {
return floorToMilliseconds() + int64_t(nanoseconds % 1'000'000 != 0);
}
/**
* Returns the maximum epoch nanoseconds value.
*/
static constexpr EpochNanoseconds max() {
// The limit is 8.64 × 10^21 nanoseconds, which is 8.64 × 10^12 seconds.
constexpr int64_t seconds = 8'640'000'000'000;
constexpr int64_t nanos = 0;
return {{seconds, nanos}};
}
/**
* Returns the minimum epoch nanoseconds value.
*/
static constexpr EpochNanoseconds min() { return -max(); }
};
// Minimum and maximum valid epoch day relative to midnight at the beginning of
// 1 January 1970 UTC.
//
// NOTE in ISODateTimeWithinLimits:
//
// Temporal.PlainDateTime objects can represent points in time within 24 hours
// (8.64 × 10**13 nanoseconds) of the Temporal.Instant boundaries. This ensures
// that a Temporal.Instant object can be converted into a Temporal.PlainDateTime
// object using any time zone.
//
// This limits the maximum valid date-time to +275760-09-13T23:59:59.999Z and
// the minimum valid date-time -271821-04-19T00:00:00.001Z. The corresponding
// maximum and minimum valid date values are therefore +275760-09-13 and
// -271821-04-19. There are exactly 100'000'000 days from 1 January 1970 UTC to
// the maximum valid date and -100'000'001 days to the minimum valid date.
constexpr inline int32_t MinEpochDay = -100'000'001;
constexpr inline int32_t MaxEpochDay = 100'000'000;
static_assert(MinEpochDay ==
EpochNanoseconds::min().seconds / ToSeconds(TemporalUnit::Day) -
1);
static_assert(MaxEpochDay ==
EpochNanoseconds::max().seconds / ToSeconds(TemporalUnit::Day));
// Maximum number of days between two valid epoch days.
constexpr inline int32_t MaxEpochDaysDuration = MaxEpochDay - MinEpochDay;
/**
* ISODate represents a date in the ISO 8601 calendar.
*/
struct ISODate final {
// [-271821, 275760]
//
// Dates are limited to the range of ±100'000'000 days relative to midnight at
// the beginning of 1 January 1970 UTC. This limits valid years to [-271821,
// 275760].
int32_t year = 0;
// [1, 12]
int32_t month = 0;
// [1, 31]
int32_t day = 0;
constexpr bool operator==(const ISODate& other) const {
return year == other.year && month == other.month && day == other.day;
}
constexpr bool operator!=(const ISODate& other) const {
return !(*this == other);
}
constexpr bool operator<(const ISODate& other) const {
if (year != other.year) {
return year < other.year;
}
if (month != other.month) {
return month < other.month;
}
return day < other.day;
}
constexpr bool operator>(const ISODate& other) const { return other < *this; }
constexpr bool operator<=(const ISODate& other) const {
return !(other < *this);
}
constexpr bool operator>=(const ISODate& other) const {
return !(*this < other);
}
/**
* The minimum ISODate within the valid limits is -271821 April, 19.
*/
static constexpr ISODate min() { return {-271821, 4, 19}; }
/**
* The maximum ISODate within the valid limits is 275760 September, 13.
*/
static constexpr ISODate max() { return {275760, 9, 13}; }
};
/**
* Time represents a time value on a 24-hour clock. Leap seconds aren't
* supported.
*/
struct Time final {
// [0, 23]
int32_t hour = 0;
// [0, 59]
int32_t minute = 0;
// [0, 59]
int32_t second = 0;
// [0, 999]
int32_t millisecond = 0;
// [0, 999]
int32_t microsecond = 0;
// [0, 999]
int32_t nanosecond = 0;
constexpr bool operator==(const Time& other) const {
return hour == other.hour && minute == other.minute &&
second == other.second && millisecond == other.millisecond &&
microsecond == other.microsecond && nanosecond == other.nanosecond;
}
constexpr bool operator!=(const Time& other) const {
return !(*this == other);
}
constexpr bool operator<(const Time& other) const {
if (hour != other.hour) {
return hour < other.hour;
}
if (minute != other.minute) {
return minute < other.minute;
}
if (second != other.second) {
return second < other.second;
}
if (millisecond != other.millisecond) {
return millisecond < other.millisecond;
}
if (microsecond != other.microsecond) {
return microsecond < other.microsecond;
}
return nanosecond < other.nanosecond;
}
constexpr bool operator>(const Time& other) const { return other < *this; }
constexpr bool operator<=(const Time& other) const {
return !(other < *this);
}
constexpr bool operator>=(const Time& other) const {
return !(*this < other);
}
};
/**
* ISODateTime represents a date-time value in the ISO 8601 calendar.
*/
struct ISODateTime final {
ISODate date;
Time time;
bool operator==(const ISODateTime& other) const {
return date == other.date && time == other.time;
}
bool operator!=(const ISODateTime& other) const { return !(*this == other); }
constexpr bool operator<(const ISODateTime& other) const {
if (date != other.date) {
return date < other.date;
}
return time < other.time;
}
constexpr bool operator>(const ISODateTime& other) const {
return other < *this;
}
constexpr bool operator<=(const ISODateTime& other) const {
return !(other < *this);
}
constexpr bool operator>=(const ISODateTime& other) const {
return !(*this < other);
}
};
// 32-bit packed date to store an ISO date within PrivateUint32Value.
struct PackedDate final {
static constexpr uint32_t DayBits = 8;
static constexpr uint32_t MonthBits = 4;
static constexpr uint32_t YearBits = 20;
static constexpr uint32_t DayShift = 0;
static constexpr uint32_t MonthShift = DayShift + DayBits;
static constexpr uint32_t YearShift = MonthShift + MonthBits;
uint32_t value = 0;
static constexpr PackedDate pack(const ISODate& date) {
return {uint32_t((date.year << YearShift) | (date.month << MonthShift) |
(date.day << DayShift))};
}
static constexpr ISODate unpack(const PackedDate& date) {
return {
int32_t(date.value) >> YearShift,
int32_t((date.value >> MonthShift) & BitMask(MonthBits)),
int32_t((date.value >> DayShift) & BitMask(DayBits)),
};
}
};
// 47-bit packed time to store a time within DoubleValue.
struct PackedTime final {
static constexpr uint32_t NanosecondBits = 10;
static constexpr uint32_t MicrosecondBits = 10;
static constexpr uint32_t MillisecondBits = 10;
static constexpr uint32_t SecondBits = 6;
static constexpr uint32_t MinuteBits = 6;
static constexpr uint32_t HourBits = 5;
static constexpr uint32_t NanosecondShift = 0;
static constexpr uint32_t MicrosecondShift = NanosecondShift + NanosecondBits;
static constexpr uint32_t MillisecondShift =
MicrosecondShift + MicrosecondBits;
static constexpr uint32_t SecondShift = MillisecondShift + MillisecondBits;
static constexpr uint32_t MinuteShift = SecondShift + SecondBits;
static constexpr uint32_t HourShift = MinuteShift + MinuteBits;
uint64_t value = 0;
static constexpr PackedTime pack(const Time& time) {
return {uint64_t(time.hour) << HourShift |
uint64_t(time.minute) << MinuteShift |
uint64_t(time.second) << SecondShift |
uint64_t(time.millisecond) << MillisecondShift |
uint64_t(time.microsecond) << MicrosecondShift |
uint64_t(time.nanosecond) << NanosecondShift};
}
static constexpr Time unpack(const PackedTime& time) {
return {
int32_t((time.value >> HourShift) & BitMask(HourBits)),
int32_t((time.value >> MinuteShift) & BitMask(MinuteBits)),
int32_t((time.value >> SecondShift) & BitMask(SecondBits)),
int32_t((time.value >> MillisecondShift) & BitMask(MillisecondBits)),
int32_t((time.value >> MicrosecondShift) & BitMask(MicrosecondBits)),
int32_t((time.value >> NanosecondShift) & BitMask(NanosecondBits)),
};
}
};
struct DateDuration;
/**
* Duration represents the difference between dates or times. Each duration
* component is an integer and all components must have the same sign.
*/
struct Duration final {
// abs(years) < 2**32
double years = 0;
// abs(months) < 2**32
double months = 0;
// abs(weeks) < 2**32
double weeks = 0;
// abs(days) < ⌈(2**53) / (24 * 60 * 60)⌉
double days = 0;
// abs(hours) < ⌈(2**53) / (60 * 60)⌉
double hours = 0;
// abs(minutes) < ⌈(2**53) / 60⌉
double minutes = 0;
// abs(seconds) < (2**53)
double seconds = 0;
// abs(milliseconds) < (2**53) * (1000**1)
double milliseconds = 0;
// abs(microseconds) < (2**53) * (1000**2)
double microseconds = 0;
// abs(nanoseconds) < (2**53) * (1000**3)
double nanoseconds = 0;
constexpr bool operator==(const Duration& other) const {
return years == other.years && months == other.months &&
weeks == other.weeks && days == other.days && hours == other.hours &&
minutes == other.minutes && seconds == other.seconds &&
milliseconds == other.milliseconds &&
microseconds == other.microseconds &&
nanoseconds == other.nanoseconds;
}
constexpr bool operator!=(const Duration& other) const {
return !(*this == other);
}
/**
* Return a new duration with every component negated.
*/
constexpr Duration negate() const {
// Add zero to convert -0 to +0.
return {
-years + (+0.0), -months + (+0.0), -weeks + (+0.0),
-days + (+0.0), -hours + (+0.0), -minutes + (+0.0),
-seconds + (+0.0), -milliseconds + (+0.0), -microseconds + (+0.0),
-nanoseconds + (+0.0),
};
}
/**
* Return the date components of this duration.
*/
inline DateDuration toDateDuration() const;
};
/**
* Date duration represents the difference between dates. Each duration
* component is an integer and all components must have the same sign.
*/
struct DateDuration final {
// abs(years) < 2**32
int64_t years = 0;
// abs(months) < 2**32
int64_t months = 0;
// abs(weeks) < 2**32
int64_t weeks = 0;
// abs(days) < ⌈(2**53) / (24 * 60 * 60)⌉
int64_t days = 0;
constexpr bool operator==(const DateDuration& other) const {
return years == other.years && months == other.months &&
weeks == other.weeks && days == other.days;
}
constexpr bool operator!=(const DateDuration& other) const {
return !(*this == other);
}
constexpr Duration toDuration() const {
return {
double(years),
double(months),
double(weeks),
double(days),
};
}
};
inline DateDuration Duration::toDateDuration() const {
return {int64_t(years), int64_t(months), int64_t(weeks), int64_t(days)};
}
/**
* Time duration with a seconds value in the range
* [-9'007'199'254'740'991, +9'007'199'254'740'991] and a nanoseconds value in
* the range [0, 999'999'999].
*/
struct TimeDuration final : SecondsAndNanoseconds<TimeDuration> {
constexpr TimeDuration& operator+=(const TimeDuration& other) {
*this = add(*this, other);
return *this;
}
constexpr TimeDuration& operator-=(const TimeDuration& other) {
*this = subtract(*this, other);
return *this;
}
constexpr TimeDuration operator+(const TimeDuration& other) const {
return add(*this, other);
}
constexpr TimeDuration operator-(const TimeDuration& other) const {
return subtract(*this, other);
}
constexpr TimeDuration operator-() const { return negate(*this); }
/**
* Returns the maximum time duration value.
*/
static constexpr TimeDuration max() {
constexpr int64_t seconds = 0x1f'ffff'ffff'ffff;
constexpr int64_t nanos = 999'999'999;
return {{seconds, nanos}};
}
/**
* Returns the minimum time duration value.
*/
static constexpr TimeDuration min() { return -max(); }
};
/**
* Internal duration represents the difference between dates or times. Each
* duration component is an integer and all components must have the same sign.
*/
struct InternalDuration final {
DateDuration date;
TimeDuration time;
constexpr bool operator==(const InternalDuration& other) const {
return date == other.date && time == other.time;
}
constexpr bool operator!=(const InternalDuration& other) const {
return !(*this == other);
}
};
} /* namespace js::temporal */
#endif /* builtin_temporal_TemporalTypes_h */