blob: 2ece2150e6bedceac1d934f59d9d199ed8185dbe [file] [log] [blame]
#![stable(feature = "duration_core", since = "1.25.0")]
//! Temporal quantification.
//!
//! Example:
//!
//! ```
//! use std::time::Duration;
//!
//! let five_seconds = Duration::new(5, 0);
//! // both declarations are equivalent
//! assert_eq!(Duration::new(5, 0), Duration::from_secs(5));
//! ```
use crate::iter::Sum;
use crate::ops::{Add, AddAssign, Div, DivAssign, Mul, MulAssign, Sub, SubAssign};
use crate::{fmt, u64};
const NANOS_PER_SEC: u32 = 1_000_000_000;
const NANOS_PER_MILLI: u32 = 1_000_000;
const NANOS_PER_MICRO: u32 = 1_000;
const MILLIS_PER_SEC: u64 = 1_000;
const MICROS_PER_SEC: u64 = 1_000_000;
/// A `Duration` type to represent a span of time, typically used for system
/// timeouts.
///
/// Each `Duration` is composed of a whole number of seconds and a fractional part
/// represented in nanoseconds. If the underlying system does not support
/// nanosecond-level precision, APIs binding a system timeout will typically round up
/// the number of nanoseconds.
///
/// `Duration`s implement many common traits, including [`Add`], [`Sub`], and other
/// [`ops`] traits.
///
/// [`Add`]: ../../std/ops/trait.Add.html
/// [`Sub`]: ../../std/ops/trait.Sub.html
/// [`ops`]: ../../std/ops/index.html
///
/// # Examples
///
/// ```
/// use std::time::Duration;
///
/// let five_seconds = Duration::new(5, 0);
/// let five_seconds_and_five_nanos = five_seconds + Duration::new(0, 5);
///
/// assert_eq!(five_seconds_and_five_nanos.as_secs(), 5);
/// assert_eq!(five_seconds_and_five_nanos.subsec_nanos(), 5);
///
/// let ten_millis = Duration::from_millis(10);
/// ```
#[stable(feature = "duration", since = "1.3.0")]
#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Default)]
pub struct Duration {
secs: u64,
nanos: u32, // Always 0 <= nanos < NANOS_PER_SEC
}
impl Duration {
/// The duration of one second.
///
/// # Examples
///
/// ```
/// #![feature(duration_constants)]
/// use std::time::Duration;
///
/// assert_eq!(Duration::SECOND, Duration::from_secs(1));
/// ```
#[unstable(feature = "duration_constants", issue = "57391")]
pub const SECOND: Duration = Duration::from_secs(1);
/// The duration of one millisecond.
///
/// # Examples
///
/// ```
/// #![feature(duration_constants)]
/// use std::time::Duration;
///
/// assert_eq!(Duration::MILLISECOND, Duration::from_millis(1));
/// ```
#[unstable(feature = "duration_constants", issue = "57391")]
pub const MILLISECOND: Duration = Duration::from_millis(1);
/// The duration of one microsecond.
///
/// # Examples
///
/// ```
/// #![feature(duration_constants)]
/// use std::time::Duration;
///
/// assert_eq!(Duration::MICROSECOND, Duration::from_micros(1));
/// ```
#[unstable(feature = "duration_constants", issue = "57391")]
pub const MICROSECOND: Duration = Duration::from_micros(1);
/// The duration of one nanosecond.
///
/// # Examples
///
/// ```
/// #![feature(duration_constants)]
/// use std::time::Duration;
///
/// assert_eq!(Duration::NANOSECOND, Duration::from_nanos(1));
/// ```
#[unstable(feature = "duration_constants", issue = "57391")]
pub const NANOSECOND: Duration = Duration::from_nanos(1);
/// Creates a new `Duration` from the specified number of whole seconds and
/// additional nanoseconds.
///
/// If the number of nanoseconds is greater than 1 billion (the number of
/// nanoseconds in a second), then it will carry over into the seconds provided.
///
/// # Panics
///
/// This constructor will panic if the carry from the nanoseconds overflows
/// the seconds counter.
///
/// # Examples
///
/// ```
/// use std::time::Duration;
///
/// let five_seconds = Duration::new(5, 0);
/// ```
#[stable(feature = "duration", since = "1.3.0")]
#[inline]
#[rustc_const_stable(feature = "duration_consts", since = "1.32.0")]
pub fn new(secs: u64, nanos: u32) -> Duration {
let secs =
secs.checked_add((nanos / NANOS_PER_SEC) as u64).expect("overflow in Duration::new");
let nanos = nanos % NANOS_PER_SEC;
Duration { secs, nanos }
}
/// Creates a new `Duration` from the specified number of whole seconds.
///
/// # Examples
///
/// ```
/// use std::time::Duration;
///
/// let duration = Duration::from_secs(5);
///
/// assert_eq!(5, duration.as_secs());
/// assert_eq!(0, duration.subsec_nanos());
/// ```
#[stable(feature = "duration", since = "1.3.0")]
#[inline]
#[rustc_promotable]
#[rustc_const_stable(feature = "duration_consts", since = "1.32.0")]
pub const fn from_secs(secs: u64) -> Duration {
Duration { secs, nanos: 0 }
}
/// Creates a new `Duration` from the specified number of milliseconds.
///
/// # Examples
///
/// ```
/// use std::time::Duration;
///
/// let duration = Duration::from_millis(2569);
///
/// assert_eq!(2, duration.as_secs());
/// assert_eq!(569_000_000, duration.subsec_nanos());
/// ```
#[stable(feature = "duration", since = "1.3.0")]
#[inline]
#[rustc_const_stable(feature = "duration_consts", since = "1.32.0")]
pub const fn from_millis(millis: u64) -> Duration {
Duration {
secs: millis / MILLIS_PER_SEC,
nanos: ((millis % MILLIS_PER_SEC) as u32) * NANOS_PER_MILLI,
}
}
/// Creates a new `Duration` from the specified number of microseconds.
///
/// # Examples
///
/// ```
/// use std::time::Duration;
///
/// let duration = Duration::from_micros(1_000_002);
///
/// assert_eq!(1, duration.as_secs());
/// assert_eq!(2000, duration.subsec_nanos());
/// ```
#[stable(feature = "duration_from_micros", since = "1.27.0")]
#[inline]
#[rustc_const_stable(feature = "duration_consts", since = "1.32.0")]
pub const fn from_micros(micros: u64) -> Duration {
Duration {
secs: micros / MICROS_PER_SEC,
nanos: ((micros % MICROS_PER_SEC) as u32) * NANOS_PER_MICRO,
}
}
/// Creates a new `Duration` from the specified number of nanoseconds.
///
/// # Examples
///
/// ```
/// use std::time::Duration;
///
/// let duration = Duration::from_nanos(1_000_000_123);
///
/// assert_eq!(1, duration.as_secs());
/// assert_eq!(123, duration.subsec_nanos());
/// ```
#[stable(feature = "duration_extras", since = "1.27.0")]
#[inline]
#[rustc_const_stable(feature = "duration_consts", since = "1.32.0")]
pub const fn from_nanos(nanos: u64) -> Duration {
Duration {
secs: nanos / (NANOS_PER_SEC as u64),
nanos: (nanos % (NANOS_PER_SEC as u64)) as u32,
}
}
/// Returns the number of _whole_ seconds contained by this `Duration`.
///
/// The returned value does not include the fractional (nanosecond) part of the
/// duration, which can be obtained using [`subsec_nanos`].
///
/// # Examples
///
/// ```
/// use std::time::Duration;
///
/// let duration = Duration::new(5, 730023852);
/// assert_eq!(duration.as_secs(), 5);
/// ```
///
/// To determine the total number of seconds represented by the `Duration`,
/// use `as_secs` in combination with [`subsec_nanos`]:
///
/// ```
/// use std::time::Duration;
///
/// let duration = Duration::new(5, 730023852);
///
/// assert_eq!(5.730023852,
/// duration.as_secs() as f64
/// + duration.subsec_nanos() as f64 * 1e-9);
/// ```
///
/// [`subsec_nanos`]: #method.subsec_nanos
#[stable(feature = "duration", since = "1.3.0")]
#[rustc_const_stable(feature = "duration", since = "1.32.0")]
#[inline]
pub const fn as_secs(&self) -> u64 {
self.secs
}
/// Returns the fractional part of this `Duration`, in whole milliseconds.
///
/// This method does **not** return the length of the duration when
/// represented by milliseconds. The returned number always represents a
/// fractional portion of a second (i.e., it is less than one thousand).
///
/// # Examples
///
/// ```
/// use std::time::Duration;
///
/// let duration = Duration::from_millis(5432);
/// assert_eq!(duration.as_secs(), 5);
/// assert_eq!(duration.subsec_millis(), 432);
/// ```
#[stable(feature = "duration_extras", since = "1.27.0")]
#[rustc_const_stable(feature = "duration_extras", since = "1.32.0")]
#[inline]
pub const fn subsec_millis(&self) -> u32 {
self.nanos / NANOS_PER_MILLI
}
/// Returns the fractional part of this `Duration`, in whole microseconds.
///
/// This method does **not** return the length of the duration when
/// represented by microseconds. The returned number always represents a
/// fractional portion of a second (i.e., it is less than one million).
///
/// # Examples
///
/// ```
/// use std::time::Duration;
///
/// let duration = Duration::from_micros(1_234_567);
/// assert_eq!(duration.as_secs(), 1);
/// assert_eq!(duration.subsec_micros(), 234_567);
/// ```
#[stable(feature = "duration_extras", since = "1.27.0")]
#[rustc_const_stable(feature = "duration_extras", since = "1.32.0")]
#[inline]
pub const fn subsec_micros(&self) -> u32 {
self.nanos / NANOS_PER_MICRO
}
/// Returns the fractional part of this `Duration`, in nanoseconds.
///
/// This method does **not** return the length of the duration when
/// represented by nanoseconds. The returned number always represents a
/// fractional portion of a second (i.e., it is less than one billion).
///
/// # Examples
///
/// ```
/// use std::time::Duration;
///
/// let duration = Duration::from_millis(5010);
/// assert_eq!(duration.as_secs(), 5);
/// assert_eq!(duration.subsec_nanos(), 10_000_000);
/// ```
#[stable(feature = "duration", since = "1.3.0")]
#[rustc_const_stable(feature = "duration", since = "1.32.0")]
#[inline]
pub const fn subsec_nanos(&self) -> u32 {
self.nanos
}
/// Returns the total number of whole milliseconds contained by this `Duration`.
///
/// # Examples
///
/// ```
/// use std::time::Duration;
///
/// let duration = Duration::new(5, 730023852);
/// assert_eq!(duration.as_millis(), 5730);
/// ```
#[stable(feature = "duration_as_u128", since = "1.33.0")]
#[rustc_const_stable(feature = "duration_as_u128", since = "1.33.0")]
#[inline]
pub const fn as_millis(&self) -> u128 {
self.secs as u128 * MILLIS_PER_SEC as u128 + (self.nanos / NANOS_PER_MILLI) as u128
}
/// Returns the total number of whole microseconds contained by this `Duration`.
///
/// # Examples
///
/// ```
/// use std::time::Duration;
///
/// let duration = Duration::new(5, 730023852);
/// assert_eq!(duration.as_micros(), 5730023);
/// ```
#[stable(feature = "duration_as_u128", since = "1.33.0")]
#[rustc_const_stable(feature = "duration_as_u128", since = "1.33.0")]
#[inline]
pub const fn as_micros(&self) -> u128 {
self.secs as u128 * MICROS_PER_SEC as u128 + (self.nanos / NANOS_PER_MICRO) as u128
}
/// Returns the total number of nanoseconds contained by this `Duration`.
///
/// # Examples
///
/// ```
/// use std::time::Duration;
///
/// let duration = Duration::new(5, 730023852);
/// assert_eq!(duration.as_nanos(), 5730023852);
/// ```
#[stable(feature = "duration_as_u128", since = "1.33.0")]
#[rustc_const_stable(feature = "duration_as_u128", since = "1.33.0")]
#[inline]
pub const fn as_nanos(&self) -> u128 {
self.secs as u128 * NANOS_PER_SEC as u128 + self.nanos as u128
}
/// Checked `Duration` addition. Computes `self + other`, returning [`None`]
/// if overflow occurred.
///
/// [`None`]: ../../std/option/enum.Option.html#variant.None
///
/// # Examples
///
/// Basic usage:
///
/// ```
/// use std::time::Duration;
///
/// assert_eq!(Duration::new(0, 0).checked_add(Duration::new(0, 1)), Some(Duration::new(0, 1)));
/// assert_eq!(Duration::new(1, 0).checked_add(Duration::new(std::u64::MAX, 0)), None);
/// ```
#[stable(feature = "duration_checked_ops", since = "1.16.0")]
#[inline]
pub fn checked_add(self, rhs: Duration) -> Option<Duration> {
if let Some(mut secs) = self.secs.checked_add(rhs.secs) {
let mut nanos = self.nanos + rhs.nanos;
if nanos >= NANOS_PER_SEC {
nanos -= NANOS_PER_SEC;
if let Some(new_secs) = secs.checked_add(1) {
secs = new_secs;
} else {
return None;
}
}
debug_assert!(nanos < NANOS_PER_SEC);
Some(Duration { secs, nanos })
} else {
None
}
}
/// Checked `Duration` subtraction. Computes `self - other`, returning [`None`]
/// if the result would be negative or if overflow occurred.
///
/// [`None`]: ../../std/option/enum.Option.html#variant.None
///
/// # Examples
///
/// Basic usage:
///
/// ```
/// use std::time::Duration;
///
/// assert_eq!(Duration::new(0, 1).checked_sub(Duration::new(0, 0)), Some(Duration::new(0, 1)));
/// assert_eq!(Duration::new(0, 0).checked_sub(Duration::new(0, 1)), None);
/// ```
#[stable(feature = "duration_checked_ops", since = "1.16.0")]
#[inline]
pub fn checked_sub(self, rhs: Duration) -> Option<Duration> {
if let Some(mut secs) = self.secs.checked_sub(rhs.secs) {
let nanos = if self.nanos >= rhs.nanos {
self.nanos - rhs.nanos
} else {
if let Some(sub_secs) = secs.checked_sub(1) {
secs = sub_secs;
self.nanos + NANOS_PER_SEC - rhs.nanos
} else {
return None;
}
};
debug_assert!(nanos < NANOS_PER_SEC);
Some(Duration { secs, nanos })
} else {
None
}
}
/// Checked `Duration` multiplication. Computes `self * other`, returning
/// [`None`] if overflow occurred.
///
/// [`None`]: ../../std/option/enum.Option.html#variant.None
///
/// # Examples
///
/// Basic usage:
///
/// ```
/// use std::time::Duration;
///
/// assert_eq!(Duration::new(0, 500_000_001).checked_mul(2), Some(Duration::new(1, 2)));
/// assert_eq!(Duration::new(std::u64::MAX - 1, 0).checked_mul(2), None);
/// ```
#[stable(feature = "duration_checked_ops", since = "1.16.0")]
#[inline]
pub fn checked_mul(self, rhs: u32) -> Option<Duration> {
// Multiply nanoseconds as u64, because it cannot overflow that way.
let total_nanos = self.nanos as u64 * rhs as u64;
let extra_secs = total_nanos / (NANOS_PER_SEC as u64);
let nanos = (total_nanos % (NANOS_PER_SEC as u64)) as u32;
if let Some(secs) =
self.secs.checked_mul(rhs as u64).and_then(|s| s.checked_add(extra_secs))
{
debug_assert!(nanos < NANOS_PER_SEC);
Some(Duration { secs, nanos })
} else {
None
}
}
/// Checked `Duration` division. Computes `self / other`, returning [`None`]
/// if `other == 0`.
///
/// [`None`]: ../../std/option/enum.Option.html#variant.None
///
/// # Examples
///
/// Basic usage:
///
/// ```
/// use std::time::Duration;
///
/// assert_eq!(Duration::new(2, 0).checked_div(2), Some(Duration::new(1, 0)));
/// assert_eq!(Duration::new(1, 0).checked_div(2), Some(Duration::new(0, 500_000_000)));
/// assert_eq!(Duration::new(2, 0).checked_div(0), None);
/// ```
#[stable(feature = "duration_checked_ops", since = "1.16.0")]
#[inline]
pub fn checked_div(self, rhs: u32) -> Option<Duration> {
if rhs != 0 {
let secs = self.secs / (rhs as u64);
let carry = self.secs - secs * (rhs as u64);
let extra_nanos = carry * (NANOS_PER_SEC as u64) / (rhs as u64);
let nanos = self.nanos / rhs + (extra_nanos as u32);
debug_assert!(nanos < NANOS_PER_SEC);
Some(Duration { secs, nanos })
} else {
None
}
}
/// Returns the number of seconds contained by this `Duration` as `f64`.
///
/// The returned value does include the fractional (nanosecond) part of the duration.
///
/// # Examples
/// ```
/// use std::time::Duration;
///
/// let dur = Duration::new(2, 700_000_000);
/// assert_eq!(dur.as_secs_f64(), 2.7);
/// ```
#[stable(feature = "duration_float", since = "1.38.0")]
#[inline]
pub fn as_secs_f64(&self) -> f64 {
(self.secs as f64) + (self.nanos as f64) / (NANOS_PER_SEC as f64)
}
/// Returns the number of seconds contained by this `Duration` as `f32`.
///
/// The returned value does include the fractional (nanosecond) part of the duration.
///
/// # Examples
/// ```
/// use std::time::Duration;
///
/// let dur = Duration::new(2, 700_000_000);
/// assert_eq!(dur.as_secs_f32(), 2.7);
/// ```
#[stable(feature = "duration_float", since = "1.38.0")]
#[inline]
pub fn as_secs_f32(&self) -> f32 {
(self.secs as f32) + (self.nanos as f32) / (NANOS_PER_SEC as f32)
}
/// Creates a new `Duration` from the specified number of seconds represented
/// as `f64`.
///
/// # Panics
/// This constructor will panic if `secs` is not finite, negative or overflows `Duration`.
///
/// # Examples
/// ```
/// use std::time::Duration;
///
/// let dur = Duration::from_secs_f64(2.7);
/// assert_eq!(dur, Duration::new(2, 700_000_000));
/// ```
#[stable(feature = "duration_float", since = "1.38.0")]
#[inline]
pub fn from_secs_f64(secs: f64) -> Duration {
const MAX_NANOS_F64: f64 = ((u64::MAX as u128 + 1) * (NANOS_PER_SEC as u128)) as f64;
let nanos = secs * (NANOS_PER_SEC as f64);
if !nanos.is_finite() {
panic!("got non-finite value when converting float to duration");
}
if nanos >= MAX_NANOS_F64 {
panic!("overflow when converting float to duration");
}
if nanos < 0.0 {
panic!("underflow when converting float to duration");
}
let nanos = nanos as u128;
Duration {
secs: (nanos / (NANOS_PER_SEC as u128)) as u64,
nanos: (nanos % (NANOS_PER_SEC as u128)) as u32,
}
}
/// Creates a new `Duration` from the specified number of seconds represented
/// as `f32`.
///
/// # Panics
/// This constructor will panic if `secs` is not finite, negative or overflows `Duration`.
///
/// # Examples
/// ```
/// use std::time::Duration;
///
/// let dur = Duration::from_secs_f32(2.7);
/// assert_eq!(dur, Duration::new(2, 700_000_000));
/// ```
#[stable(feature = "duration_float", since = "1.38.0")]
#[inline]
pub fn from_secs_f32(secs: f32) -> Duration {
const MAX_NANOS_F32: f32 = ((u64::MAX as u128 + 1) * (NANOS_PER_SEC as u128)) as f32;
let nanos = secs * (NANOS_PER_SEC as f32);
if !nanos.is_finite() {
panic!("got non-finite value when converting float to duration");
}
if nanos >= MAX_NANOS_F32 {
panic!("overflow when converting float to duration");
}
if nanos < 0.0 {
panic!("underflow when converting float to duration");
}
let nanos = nanos as u128;
Duration {
secs: (nanos / (NANOS_PER_SEC as u128)) as u64,
nanos: (nanos % (NANOS_PER_SEC as u128)) as u32,
}
}
/// Multiplies `Duration` by `f64`.
///
/// # Panics
/// This method will panic if result is not finite, negative or overflows `Duration`.
///
/// # Examples
/// ```
/// use std::time::Duration;
///
/// let dur = Duration::new(2, 700_000_000);
/// assert_eq!(dur.mul_f64(3.14), Duration::new(8, 478_000_000));
/// assert_eq!(dur.mul_f64(3.14e5), Duration::new(847_800, 0));
/// ```
#[stable(feature = "duration_float", since = "1.38.0")]
#[inline]
pub fn mul_f64(self, rhs: f64) -> Duration {
Duration::from_secs_f64(rhs * self.as_secs_f64())
}
/// Multiplies `Duration` by `f32`.
///
/// # Panics
/// This method will panic if result is not finite, negative or overflows `Duration`.
///
/// # Examples
/// ```
/// use std::time::Duration;
///
/// let dur = Duration::new(2, 700_000_000);
/// // note that due to rounding errors result is slightly different
/// // from 8.478 and 847800.0
/// assert_eq!(dur.mul_f32(3.14), Duration::new(8, 478_000_640));
/// assert_eq!(dur.mul_f32(3.14e5), Duration::new(847799, 969_120_256));
/// ```
#[stable(feature = "duration_float", since = "1.38.0")]
#[inline]
pub fn mul_f32(self, rhs: f32) -> Duration {
Duration::from_secs_f32(rhs * self.as_secs_f32())
}
/// Divide `Duration` by `f64`.
///
/// # Panics
/// This method will panic if result is not finite, negative or overflows `Duration`.
///
/// # Examples
/// ```
/// use std::time::Duration;
///
/// let dur = Duration::new(2, 700_000_000);
/// assert_eq!(dur.div_f64(3.14), Duration::new(0, 859_872_611));
/// // note that truncation is used, not rounding
/// assert_eq!(dur.div_f64(3.14e5), Duration::new(0, 8_598));
/// ```
#[stable(feature = "duration_float", since = "1.38.0")]
#[inline]
pub fn div_f64(self, rhs: f64) -> Duration {
Duration::from_secs_f64(self.as_secs_f64() / rhs)
}
/// Divide `Duration` by `f32`.
///
/// # Panics
/// This method will panic if result is not finite, negative or overflows `Duration`.
///
/// # Examples
/// ```
/// use std::time::Duration;
///
/// let dur = Duration::new(2, 700_000_000);
/// // note that due to rounding errors result is slightly
/// // different from 0.859_872_611
/// assert_eq!(dur.div_f32(3.14), Duration::new(0, 859_872_576));
/// // note that truncation is used, not rounding
/// assert_eq!(dur.div_f32(3.14e5), Duration::new(0, 8_598));
/// ```
#[stable(feature = "duration_float", since = "1.38.0")]
#[inline]
pub fn div_f32(self, rhs: f32) -> Duration {
Duration::from_secs_f32(self.as_secs_f32() / rhs)
}
/// Divide `Duration` by `Duration` and return `f64`.
///
/// # Examples
/// ```
/// #![feature(div_duration)]
/// use std::time::Duration;
///
/// let dur1 = Duration::new(2, 700_000_000);
/// let dur2 = Duration::new(5, 400_000_000);
/// assert_eq!(dur1.div_duration_f64(dur2), 0.5);
/// ```
#[unstable(feature = "div_duration", issue = "63139")]
#[inline]
pub fn div_duration_f64(self, rhs: Duration) -> f64 {
self.as_secs_f64() / rhs.as_secs_f64()
}
/// Divide `Duration` by `Duration` and return `f32`.
///
/// # Examples
/// ```
/// #![feature(div_duration)]
/// use std::time::Duration;
///
/// let dur1 = Duration::new(2, 700_000_000);
/// let dur2 = Duration::new(5, 400_000_000);
/// assert_eq!(dur1.div_duration_f32(dur2), 0.5);
/// ```
#[unstable(feature = "div_duration", issue = "63139")]
#[inline]
pub fn div_duration_f32(self, rhs: Duration) -> f32 {
self.as_secs_f32() / rhs.as_secs_f32()
}
}
#[stable(feature = "duration", since = "1.3.0")]
impl Add for Duration {
type Output = Duration;
fn add(self, rhs: Duration) -> Duration {
self.checked_add(rhs).expect("overflow when adding durations")
}
}
#[stable(feature = "time_augmented_assignment", since = "1.9.0")]
impl AddAssign for Duration {
fn add_assign(&mut self, rhs: Duration) {
*self = *self + rhs;
}
}
#[stable(feature = "duration", since = "1.3.0")]
impl Sub for Duration {
type Output = Duration;
fn sub(self, rhs: Duration) -> Duration {
self.checked_sub(rhs).expect("overflow when subtracting durations")
}
}
#[stable(feature = "time_augmented_assignment", since = "1.9.0")]
impl SubAssign for Duration {
fn sub_assign(&mut self, rhs: Duration) {
*self = *self - rhs;
}
}
#[stable(feature = "duration", since = "1.3.0")]
impl Mul<u32> for Duration {
type Output = Duration;
fn mul(self, rhs: u32) -> Duration {
self.checked_mul(rhs).expect("overflow when multiplying duration by scalar")
}
}
#[stable(feature = "symmetric_u32_duration_mul", since = "1.31.0")]
impl Mul<Duration> for u32 {
type Output = Duration;
fn mul(self, rhs: Duration) -> Duration {
rhs * self
}
}
#[stable(feature = "time_augmented_assignment", since = "1.9.0")]
impl MulAssign<u32> for Duration {
fn mul_assign(&mut self, rhs: u32) {
*self = *self * rhs;
}
}
#[stable(feature = "duration", since = "1.3.0")]
impl Div<u32> for Duration {
type Output = Duration;
fn div(self, rhs: u32) -> Duration {
self.checked_div(rhs).expect("divide by zero error when dividing duration by scalar")
}
}
#[stable(feature = "time_augmented_assignment", since = "1.9.0")]
impl DivAssign<u32> for Duration {
fn div_assign(&mut self, rhs: u32) {
*self = *self / rhs;
}
}
macro_rules! sum_durations {
($iter:expr) => {{
let mut total_secs: u64 = 0;
let mut total_nanos: u64 = 0;
for entry in $iter {
total_secs =
total_secs.checked_add(entry.secs).expect("overflow in iter::sum over durations");
total_nanos = match total_nanos.checked_add(entry.nanos as u64) {
Some(n) => n,
None => {
total_secs = total_secs
.checked_add(total_nanos / NANOS_PER_SEC as u64)
.expect("overflow in iter::sum over durations");
(total_nanos % NANOS_PER_SEC as u64) + entry.nanos as u64
}
};
}
total_secs = total_secs
.checked_add(total_nanos / NANOS_PER_SEC as u64)
.expect("overflow in iter::sum over durations");
total_nanos = total_nanos % NANOS_PER_SEC as u64;
Duration { secs: total_secs, nanos: total_nanos as u32 }
}};
}
#[stable(feature = "duration_sum", since = "1.16.0")]
impl Sum for Duration {
fn sum<I: Iterator<Item = Duration>>(iter: I) -> Duration {
sum_durations!(iter)
}
}
#[stable(feature = "duration_sum", since = "1.16.0")]
impl<'a> Sum<&'a Duration> for Duration {
fn sum<I: Iterator<Item = &'a Duration>>(iter: I) -> Duration {
sum_durations!(iter)
}
}
#[stable(feature = "duration_debug_impl", since = "1.27.0")]
impl fmt::Debug for Duration {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
/// Formats a floating point number in decimal notation.
///
/// The number is given as the `integer_part` and a fractional part.
/// The value of the fractional part is `fractional_part / divisor`. So
/// `integer_part` = 3, `fractional_part` = 12 and `divisor` = 100
/// represents the number `3.012`. Trailing zeros are omitted.
///
/// `divisor` must not be above 100_000_000. It also should be a power
/// of 10, everything else doesn't make sense. `fractional_part` has
/// to be less than `10 * divisor`!
fn fmt_decimal(
f: &mut fmt::Formatter<'_>,
mut integer_part: u64,
mut fractional_part: u32,
mut divisor: u32,
) -> fmt::Result {
// Encode the fractional part into a temporary buffer. The buffer
// only need to hold 9 elements, because `fractional_part` has to
// be smaller than 10^9. The buffer is prefilled with '0' digits
// to simplify the code below.
let mut buf = [b'0'; 9];
// The next digit is written at this position
let mut pos = 0;
// We keep writing digits into the buffer while there are non-zero
// digits left and we haven't written enough digits yet.
while fractional_part > 0 && pos < f.precision().unwrap_or(9) {
// Write new digit into the buffer
buf[pos] = b'0' + (fractional_part / divisor) as u8;
fractional_part %= divisor;
divisor /= 10;
pos += 1;
}
// If a precision < 9 was specified, there may be some non-zero
// digits left that weren't written into the buffer. In that case we
// need to perform rounding to match the semantics of printing
// normal floating point numbers. However, we only need to do work
// when rounding up. This happens if the first digit of the
// remaining ones is >= 5.
if fractional_part > 0 && fractional_part >= divisor * 5 {
// Round up the number contained in the buffer. We go through
// the buffer backwards and keep track of the carry.
let mut rev_pos = pos;
let mut carry = true;
while carry && rev_pos > 0 {
rev_pos -= 1;
// If the digit in the buffer is not '9', we just need to
// increment it and can stop then (since we don't have a
// carry anymore). Otherwise, we set it to '0' (overflow)
// and continue.
if buf[rev_pos] < b'9' {
buf[rev_pos] += 1;
carry = false;
} else {
buf[rev_pos] = b'0';
}
}
// If we still have the carry bit set, that means that we set
// the whole buffer to '0's and need to increment the integer
// part.
if carry {
integer_part += 1;
}
}
// Determine the end of the buffer: if precision is set, we just
// use as many digits from the buffer (capped to 9). If it isn't
// set, we only use all digits up to the last non-zero one.
let end = f.precision().map(|p| crate::cmp::min(p, 9)).unwrap_or(pos);
// If we haven't emitted a single fractional digit and the precision
// wasn't set to a non-zero value, we don't print the decimal point.
if end == 0 {
write!(f, "{}", integer_part)
} else {
// SAFETY: We are only writing ASCII digits into the buffer and it was
// initialized with '0's, so it contains valid UTF8.
let s = unsafe { crate::str::from_utf8_unchecked(&buf[..end]) };
// If the user request a precision > 9, we pad '0's at the end.
let w = f.precision().unwrap_or(pos);
write!(f, "{}.{:0<width$}", integer_part, s, width = w)
}
}
// Print leading '+' sign if requested
if f.sign_plus() {
write!(f, "+")?;
}
if self.secs > 0 {
fmt_decimal(f, self.secs, self.nanos, 100_000_000)?;
f.write_str("s")
} else if self.nanos >= 1_000_000 {
fmt_decimal(f, self.nanos as u64 / 1_000_000, self.nanos % 1_000_000, 100_000)?;
f.write_str("ms")
} else if self.nanos >= 1_000 {
fmt_decimal(f, self.nanos as u64 / 1_000, self.nanos % 1_000, 100)?;
f.write_str("┬Ás")
} else {
fmt_decimal(f, self.nanos as u64, 0, 1)?;
f.write_str("ns")
}
}
}