fugit/instant.rs
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use crate::duration::Duration;
use crate::helpers::{self, Helpers};
use core::cmp::Ordering;
use core::ops;
/// Represents an instant in time.
///
/// The generic `T` can either be `u32` or `u64`, and the const generics represent the ratio of the
/// ticks contained within the instant: `instant in seconds = NOM / DENOM * ticks`
#[derive(Clone, Copy, Debug)]
pub struct Instant<T, const NOM: u32, const DENOM: u32> {
ticks: T,
}
macro_rules! impl_instant_for_integer {
($i:ty) => {
impl<const NOM: u32, const DENOM: u32> Instant<$i, NOM, DENOM> {
/// Create an `Instant` from a ticks value.
///
/// ```
/// # use fugit::*;
#[doc = concat!("let _i = Instant::<", stringify!($i), ", 1, 1_000>::from_ticks(1);")]
/// ```
#[inline]
pub const fn from_ticks(ticks: $i) -> Self {
helpers::greater_than_0::<NOM>();
helpers::greater_than_0::<DENOM>();
Instant { ticks }
}
/// Extract the ticks from an `Instant`.
///
/// ```
/// # use fugit::*;
#[doc = concat!("let i = Instant::<", stringify!($i), ", 1, 1_000>::from_ticks(234);")]
///
/// assert_eq!(i.ticks(), 234);
/// ```
#[inline]
pub const fn ticks(&self) -> $i {
self.ticks
}
/// Const comparison of `Instant`s.
///
/// ```
/// # use fugit::*;
#[doc = concat!("let i1 = Instant::<", stringify!($i), ", 1, 1_000>::from_ticks(1);")]
#[doc = concat!("let i2 = Instant::<", stringify!($i), ", 1, 1_000>::from_ticks(2);")]
///
/// assert_eq!(i1.const_cmp(i2), core::cmp::Ordering::Less);
/// ```
///
/// This function takes into account that ticks might wrap around. If the absolute
/// values of `self` and `other` differ by more than half the possible range, it is
/// assumed that an overflow occured and the result is reversed:
///
/// ```
/// # use fugit::*;
#[doc = concat!("let i1 = Instant::<", stringify!($i), ", 1, 1_000>::from_ticks(", stringify!($i),"::MAX);")]
#[doc = concat!("let i2 = Instant::<", stringify!($i), ", 1, 1_000>::from_ticks(1);")]
///
/// assert_eq!(i1.const_cmp(i2), core::cmp::Ordering::Less);
/// ```
#[inline]
pub const fn const_cmp(self, other: Self) -> Ordering {
if self.ticks == other.ticks {
Ordering::Equal
} else {
let v = self.ticks.wrapping_sub(other.ticks);
// not using `v.cmp(<$i>::MAX / 2).reverse()` due to `cmp` being non-const
if v > <$i>::MAX / 2 {
Ordering::Less
} else if v < <$i>::MAX / 2 {
Ordering::Greater
} else {
Ordering::Equal
}
}
}
/// Duration between since the start of the `Instant`. This assumes an instant which
/// won't wrap within the execution of the program.
///
/// ```
/// # use fugit::*;
#[doc = concat!("let i = Instant::<", stringify!($i), ", 1, 1_000>::from_ticks(11);")]
///
/// assert_eq!(i.duration_since_epoch().ticks(), 11);
/// ```
#[inline]
pub const fn duration_since_epoch(self) -> Duration<$i, NOM, DENOM> {
Duration::<$i, NOM, DENOM>::from_ticks(self.ticks())
}
/// Duration between `Instant`s.
///
/// ```
/// # use fugit::*;
#[doc = concat!("let i1 = Instant::<", stringify!($i), ", 1, 1_000>::from_ticks(1);")]
#[doc = concat!("let i2 = Instant::<", stringify!($i), ", 1, 1_000>::from_ticks(2);")]
///
/// assert_eq!(i1.checked_duration_since(i2), None);
/// assert_eq!(i2.checked_duration_since(i1).unwrap().ticks(), 1);
/// ```
#[inline]
pub const fn checked_duration_since(
self,
other: Self,
) -> Option<Duration<$i, NOM, DENOM>> {
match self.const_cmp(other) {
Ordering::Greater | Ordering::Equal => {
Some(Duration::<$i, NOM, DENOM>::from_ticks(
self.ticks.wrapping_sub(other.ticks),
))
}
Ordering::Less => None,
}
}
/// Subtract a `Duration` from an `Instant` while checking for overflow.
///
/// ```
/// # use fugit::*;
#[doc = concat!("let i = Instant::<", stringify!($i), ", 1, 1_000>::from_ticks(1);")]
#[doc = concat!("let d = Duration::<", stringify!($i), ", 1, 1_000>::from_ticks(1);")]
///
/// assert_eq!(i.checked_sub_duration(d).unwrap().ticks(), 0);
/// ```
pub const fn checked_sub_duration<const O_NOM: u32, const O_DENOM: u32>(
self,
other: Duration<$i, O_NOM, O_DENOM>,
) -> Option<Self> {
if Helpers::<NOM, DENOM, O_NOM, O_DENOM>::SAME_BASE {
Some(Instant::<$i, NOM, DENOM>::from_ticks(
self.ticks.wrapping_sub(other.ticks()),
))
} else {
if let Some(lh) = other
.ticks()
.checked_mul(Helpers::<NOM, DENOM, O_NOM, O_DENOM>::LD_TIMES_RN as $i)
{
let ticks = lh / Helpers::<NOM, DENOM, O_NOM, O_DENOM>::RD_TIMES_LN as $i;
Some(Instant::<$i, NOM, DENOM>::from_ticks(
self.ticks.wrapping_sub(ticks),
))
} else {
None
}
}
}
/// Add a `Duration` to an `Instant` while checking for overflow.
///
/// ```
/// # use fugit::*;
#[doc = concat!("let i = Instant::<", stringify!($i), ", 1, 1_000>::from_ticks(1);")]
#[doc = concat!("let d = Duration::<", stringify!($i), ", 1, 1_000>::from_ticks(1);")]
///
/// assert_eq!(i.checked_add_duration(d).unwrap().ticks(), 2);
/// ```
pub const fn checked_add_duration<const O_NOM: u32, const O_DENOM: u32>(
self,
other: Duration<$i, O_NOM, O_DENOM>,
) -> Option<Self> {
if Helpers::<NOM, DENOM, O_NOM, O_DENOM>::SAME_BASE {
Some(Instant::<$i, NOM, DENOM>::from_ticks(
self.ticks.wrapping_add(other.ticks()),
))
} else {
if let Some(lh) = other
.ticks()
.checked_mul(Helpers::<NOM, DENOM, O_NOM, O_DENOM>::LD_TIMES_RN as $i)
{
let ticks = lh / Helpers::<NOM, DENOM, O_NOM, O_DENOM>::RD_TIMES_LN as $i;
Some(Instant::<$i, NOM, DENOM>::from_ticks(
self.ticks.wrapping_add(ticks),
))
} else {
None
}
}
}
}
impl<const NOM: u32, const DENOM: u32> PartialOrd for Instant<$i, NOM, DENOM> {
/// This implementation deviates from the definition of
/// [PartialOrd::partial_cmp](core::cmp::PartialOrd::partial_cmp):
///
/// It takes into account that ticks might wrap around. If the absolute
/// values of `self` and `other` differ by more than half the possible range, it is
/// assumed that an overflow occured and the result is reversed.
///
/// That breaks the transitivity invariant: a < b and b < c no longer implies a < c.
#[inline]
fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
Some(self.const_cmp(*other))
}
}
impl<const NOM: u32, const DENOM: u32> Ord for Instant<$i, NOM, DENOM> {
/// This implementation deviates from the definition of
/// [Ord::cmp](core::cmp::Ord::cmp):
///
/// It takes into account that ticks might wrap around. If the absolute
/// values of `self` and `other` differ by more than half the possible range, it is
/// assumed that an overflow occured and the result is reversed.
///
/// That breaks the transitivity invariant: a < b and b < c no longer implies a < c.
#[inline]
fn cmp(&self, other: &Self) -> Ordering {
self.const_cmp(*other)
}
}
impl<const NOM: u32, const DENOM: u32> PartialEq for Instant<$i, NOM, DENOM> {
#[inline]
fn eq(&self, other: &Self) -> bool {
self.ticks.eq(&other.ticks)
}
}
impl<const NOM: u32, const DENOM: u32> Eq for Instant<$i, NOM, DENOM> {}
// Instant - Instant = Duration
// We have limited this to use same numerator and denominator in both left and right hand sides,
// this allows for the extension traits to work. For usage with different fraction, use
// `checked_duration_since`.
impl<const NOM: u32, const DENOM: u32> ops::Sub<Instant<$i, NOM, DENOM>>
for Instant<$i, NOM, DENOM>
{
type Output = Duration<$i, NOM, DENOM>;
#[inline]
fn sub(self, other: Self) -> Self::Output {
if let Some(v) = self.checked_duration_since(other) {
v
} else {
panic!("Sub failed! Other > self");
}
}
}
// Instant - Duration = Instant
// We have limited this to use same numerator and denominator in both left and right hand sides,
// this allows for the extension traits to work. For usage with different fraction, use
// `checked_sub_duration`.
impl<const NOM: u32, const DENOM: u32> ops::Sub<Duration<$i, NOM, DENOM>>
for Instant<$i, NOM, DENOM>
{
type Output = Instant<$i, NOM, DENOM>;
#[inline]
fn sub(self, other: Duration<$i, NOM, DENOM>) -> Self::Output {
if let Some(v) = self.checked_sub_duration(other) {
v
} else {
panic!("Sub failed! Overflow");
}
}
}
// Instant -= Duration
// We have limited this to use same numerator and denominator in both left and right hand sides,
// this allows for the extension traits to work. For usage with different fraction, use
// `checked_sub_duration`.
impl<const NOM: u32, const DENOM: u32> ops::SubAssign<Duration<$i, NOM, DENOM>>
for Instant<$i, NOM, DENOM>
{
#[inline]
fn sub_assign(&mut self, other: Duration<$i, NOM, DENOM>) {
*self = *self - other;
}
}
// Instant + Duration = Instant
// We have limited this to use same numerator and denominator in both left and right hand sides,
// this allows for the extension traits to work. For usage with different fraction, use
// `checked_add_duration`.
impl<const NOM: u32, const DENOM: u32> ops::Add<Duration<$i, NOM, DENOM>>
for Instant<$i, NOM, DENOM>
{
type Output = Instant<$i, NOM, DENOM>;
#[inline]
fn add(self, other: Duration<$i, NOM, DENOM>) -> Self::Output {
if let Some(v) = self.checked_add_duration(other) {
v
} else {
panic!("Add failed! Overflow");
}
}
}
// Instant += Duration
// We have limited this to use same numerator and denominator in both left and right hand sides,
// this allows for the extension traits to work. For usage with different fraction, use
// `checked_add_duration`.
impl<const NOM: u32, const DENOM: u32> ops::AddAssign<Duration<$i, NOM, DENOM>>
for Instant<$i, NOM, DENOM>
{
#[inline]
fn add_assign(&mut self, other: Duration<$i, NOM, DENOM>) {
*self = *self + other;
}
}
#[cfg(feature = "defmt")]
impl<const NOM: u32, const DENOM: u32> defmt::Format for Instant<$i, NOM, DENOM> {
fn format(&self, f: defmt::Formatter) {
if NOM == 3_600 && DENOM == 1 {
defmt::write!(f, "{} h", self.ticks)
} else if NOM == 60 && DENOM == 1 {
defmt::write!(f, "{} min", self.ticks)
} else if NOM == 1 && DENOM == 1 {
defmt::write!(f, "{} s", self.ticks)
} else if NOM == 1 && DENOM == 1_000 {
defmt::write!(f, "{} ms", self.ticks)
} else if NOM == 1 && DENOM == 1_000_000 {
defmt::write!(f, "{} us", self.ticks)
} else if NOM == 1 && DENOM == 1_000_000_000 {
defmt::write!(f, "{} ns", self.ticks)
} else {
defmt::write!(f, "{} ticks @ ({}/{})", self.ticks, NOM, DENOM)
}
}
}
impl<const NOM: u32, const DENOM: u32> core::fmt::Display for Instant<$i, NOM, DENOM> {
fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
if NOM == 3_600 && DENOM == 1 {
write!(f, "{} h", self.ticks)
} else if NOM == 60 && DENOM == 1 {
write!(f, "{} min", self.ticks)
} else if NOM == 1 && DENOM == 1 {
write!(f, "{} s", self.ticks)
} else if NOM == 1 && DENOM == 1_000 {
write!(f, "{} ms", self.ticks)
} else if NOM == 1 && DENOM == 1_000_000 {
write!(f, "{} us", self.ticks)
} else if NOM == 1 && DENOM == 1_000_000_000 {
write!(f, "{} ns", self.ticks)
} else {
write!(f, "{} ticks @ ({}/{})", self.ticks, NOM, DENOM)
}
}
}
};
}
impl_instant_for_integer!(u32);
impl_instant_for_integer!(u64);
//
// Operations between u32 Duration and u64 Instant
//
// Instant - Duration = Instant
// We have limited this to use same numerator and denominator in both left and right hand sides,
// this allows for the extension traits to work. For usage with different fraction, use
// `checked_sub_duration`.
impl<const NOM: u32, const DENOM: u32> ops::Sub<Duration<u32, NOM, DENOM>>
for Instant<u64, NOM, DENOM>
{
type Output = Instant<u64, NOM, DENOM>;
#[inline]
fn sub(self, other: Duration<u32, NOM, DENOM>) -> Self::Output {
if let Some(v) = self.checked_sub_duration(other.into()) {
v
} else {
panic!("Sub failed! Overflow");
}
}
}
// Instant -= Duration
// We have limited this to use same numerator and denominator in both left and right hand sides,
// this allows for the extension traits to work. For usage with different fraction, use
// `checked_sub_duration`.
impl<const NOM: u32, const DENOM: u32> ops::SubAssign<Duration<u32, NOM, DENOM>>
for Instant<u64, NOM, DENOM>
{
#[inline]
fn sub_assign(&mut self, other: Duration<u32, NOM, DENOM>) {
*self = *self - other;
}
}
// Instant + Duration = Instant
// We have limited this to use same numerator and denominator in both left and right hand sides,
// this allows for the extension traits to work. For usage with different fraction, use
// `checked_add_duration`.
impl<const NOM: u32, const DENOM: u32> ops::Add<Duration<u32, NOM, DENOM>>
for Instant<u64, NOM, DENOM>
{
type Output = Instant<u64, NOM, DENOM>;
#[inline]
fn add(self, other: Duration<u32, NOM, DENOM>) -> Self::Output {
if let Some(v) = self.checked_add_duration(other.into()) {
v
} else {
panic!("Add failed! Overflow");
}
}
}
// Instant += Duration
// We have limited this to use same numerator and denominator in both left and right hand sides,
// this allows for the extension traits to work. For usage with different fraction, use
// `checked_add_duration`.
impl<const NOM: u32, const DENOM: u32> ops::AddAssign<Duration<u32, NOM, DENOM>>
for Instant<u64, NOM, DENOM>
{
#[inline]
fn add_assign(&mut self, other: Duration<u32, NOM, DENOM>) {
*self = *self + other;
}
}
// impl<const L_NOM: u32, const L_DENOM: u32, const R_NOM: u32, const R_DENOM: u32>
// ops::Add<Duration<u32, R_NOM, R_DENOM>> for Duration<u64, L_NOM, L_DENOM>
// {
// type Output = Duration<u64, L_NOM, L_DENOM>;
//
// #[inline]
// fn add(self, other: Duration<u32, R_NOM, R_DENOM>) -> Self::Output {
// self.add(Duration::<u64, L_NOM, L_DENOM>::from_ticks(
// other.ticks() as u64
// ))
// }
// }