1 #![stable(feature = "duration_core", since = "1.25.0")]
3 //! Temporal quantification.
8 //! use std::time::Duration;
10 //! let five_seconds = Duration::new(5, 0);
11 //! // both declarations are equivalent
12 //! assert_eq!(Duration::new(5, 0), Duration::from_secs(5));
16 use crate::ops::{Add, AddAssign, Div, DivAssign, Mul, MulAssign, Sub, SubAssign};
17 use crate::{fmt, u64};
19 const NANOS_PER_SEC: u32 = 1_000_000_000;
20 const NANOS_PER_MILLI: u32 = 1_000_000;
21 const NANOS_PER_MICRO: u32 = 1_000;
22 const MILLIS_PER_SEC: u64 = 1_000;
23 const MICROS_PER_SEC: u64 = 1_000_000;
25 /// A `Duration` type to represent a span of time, typically used for system
28 /// Each `Duration` is composed of a whole number of seconds and a fractional part
29 /// represented in nanoseconds. If the underlying system does not support
30 /// nanosecond-level precision, APIs binding a system timeout will typically round up
31 /// the number of nanoseconds.
33 /// `Duration`s implement many common traits, including [`Add`], [`Sub`], and other
36 /// [`Add`]: ../../std/ops/trait.Add.html
37 /// [`Sub`]: ../../std/ops/trait.Sub.html
38 /// [`ops`]: ../../std/ops/index.html
43 /// use std::time::Duration;
45 /// let five_seconds = Duration::new(5, 0);
46 /// let five_seconds_and_five_nanos = five_seconds + Duration::new(0, 5);
48 /// assert_eq!(five_seconds_and_five_nanos.as_secs(), 5);
49 /// assert_eq!(five_seconds_and_five_nanos.subsec_nanos(), 5);
51 /// let ten_millis = Duration::from_millis(10);
53 #[stable(feature = "duration", since = "1.3.0")]
54 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Default)]
57 nanos: u32, // Always 0 <= nanos < NANOS_PER_SEC
61 /// The duration of one second.
66 /// #![feature(duration_constants)]
67 /// use std::time::Duration;
69 /// assert_eq!(Duration::SECOND, Duration::from_secs(1));
71 #[unstable(feature = "duration_constants", issue = "57391")]
72 pub const SECOND: Duration = Duration::from_secs(1);
74 /// The duration of one millisecond.
79 /// #![feature(duration_constants)]
80 /// use std::time::Duration;
82 /// assert_eq!(Duration::MILLISECOND, Duration::from_millis(1));
84 #[unstable(feature = "duration_constants", issue = "57391")]
85 pub const MILLISECOND: Duration = Duration::from_millis(1);
87 /// The duration of one microsecond.
92 /// #![feature(duration_constants)]
93 /// use std::time::Duration;
95 /// assert_eq!(Duration::MICROSECOND, Duration::from_micros(1));
97 #[unstable(feature = "duration_constants", issue = "57391")]
98 pub const MICROSECOND: Duration = Duration::from_micros(1);
100 /// The duration of one nanosecond.
105 /// #![feature(duration_constants)]
106 /// use std::time::Duration;
108 /// assert_eq!(Duration::NANOSECOND, Duration::from_nanos(1));
110 #[unstable(feature = "duration_constants", issue = "57391")]
111 pub const NANOSECOND: Duration = Duration::from_nanos(1);
113 /// Creates a new `Duration` from the specified number of whole seconds and
114 /// additional nanoseconds.
116 /// If the number of nanoseconds is greater than 1 billion (the number of
117 /// nanoseconds in a second), then it will carry over into the seconds provided.
121 /// This constructor will panic if the carry from the nanoseconds overflows
122 /// the seconds counter.
127 /// use std::time::Duration;
129 /// let five_seconds = Duration::new(5, 0);
131 #[stable(feature = "duration", since = "1.3.0")]
133 #[rustc_const_stable(feature = "duration_consts", since = "1.32.0")]
134 pub fn new(secs: u64, nanos: u32) -> Duration {
136 secs.checked_add((nanos / NANOS_PER_SEC) as u64).expect("overflow in Duration::new");
137 let nanos = nanos % NANOS_PER_SEC;
138 Duration { secs, nanos }
141 /// Creates a new `Duration` from the specified number of whole seconds.
146 /// use std::time::Duration;
148 /// let duration = Duration::from_secs(5);
150 /// assert_eq!(5, duration.as_secs());
151 /// assert_eq!(0, duration.subsec_nanos());
153 #[stable(feature = "duration", since = "1.3.0")]
156 #[rustc_const_stable(feature = "duration_consts", since = "1.32.0")]
157 pub const fn from_secs(secs: u64) -> Duration {
158 Duration { secs, nanos: 0 }
161 /// Creates a new `Duration` from the specified number of milliseconds.
166 /// use std::time::Duration;
168 /// let duration = Duration::from_millis(2569);
170 /// assert_eq!(2, duration.as_secs());
171 /// assert_eq!(569_000_000, duration.subsec_nanos());
173 #[stable(feature = "duration", since = "1.3.0")]
175 #[rustc_const_stable(feature = "duration_consts", since = "1.32.0")]
176 pub const fn from_millis(millis: u64) -> Duration {
178 secs: millis / MILLIS_PER_SEC,
179 nanos: ((millis % MILLIS_PER_SEC) as u32) * NANOS_PER_MILLI,
183 /// Creates a new `Duration` from the specified number of microseconds.
188 /// use std::time::Duration;
190 /// let duration = Duration::from_micros(1_000_002);
192 /// assert_eq!(1, duration.as_secs());
193 /// assert_eq!(2000, duration.subsec_nanos());
195 #[stable(feature = "duration_from_micros", since = "1.27.0")]
197 #[rustc_const_stable(feature = "duration_consts", since = "1.32.0")]
198 pub const fn from_micros(micros: u64) -> Duration {
200 secs: micros / MICROS_PER_SEC,
201 nanos: ((micros % MICROS_PER_SEC) as u32) * NANOS_PER_MICRO,
205 /// Creates a new `Duration` from the specified number of nanoseconds.
210 /// use std::time::Duration;
212 /// let duration = Duration::from_nanos(1_000_000_123);
214 /// assert_eq!(1, duration.as_secs());
215 /// assert_eq!(123, duration.subsec_nanos());
217 #[stable(feature = "duration_extras", since = "1.27.0")]
219 #[rustc_const_stable(feature = "duration_consts", since = "1.32.0")]
220 pub const fn from_nanos(nanos: u64) -> Duration {
222 secs: nanos / (NANOS_PER_SEC as u64),
223 nanos: (nanos % (NANOS_PER_SEC as u64)) as u32,
227 /// Returns the number of _whole_ seconds contained by this `Duration`.
229 /// The returned value does not include the fractional (nanosecond) part of the
230 /// duration, which can be obtained using [`subsec_nanos`].
235 /// use std::time::Duration;
237 /// let duration = Duration::new(5, 730023852);
238 /// assert_eq!(duration.as_secs(), 5);
241 /// To determine the total number of seconds represented by the `Duration`,
242 /// use `as_secs` in combination with [`subsec_nanos`]:
245 /// use std::time::Duration;
247 /// let duration = Duration::new(5, 730023852);
249 /// assert_eq!(5.730023852,
250 /// duration.as_secs() as f64
251 /// + duration.subsec_nanos() as f64 * 1e-9);
254 /// [`subsec_nanos`]: #method.subsec_nanos
255 #[stable(feature = "duration", since = "1.3.0")]
256 #[rustc_const_stable(feature = "duration", since = "1.32.0")]
258 pub const fn as_secs(&self) -> u64 {
262 /// Returns the fractional part of this `Duration`, in whole milliseconds.
264 /// This method does **not** return the length of the duration when
265 /// represented by milliseconds. The returned number always represents a
266 /// fractional portion of a second (i.e., it is less than one thousand).
271 /// use std::time::Duration;
273 /// let duration = Duration::from_millis(5432);
274 /// assert_eq!(duration.as_secs(), 5);
275 /// assert_eq!(duration.subsec_millis(), 432);
277 #[stable(feature = "duration_extras", since = "1.27.0")]
278 #[rustc_const_stable(feature = "duration_extras", since = "1.32.0")]
280 pub const fn subsec_millis(&self) -> u32 {
281 self.nanos / NANOS_PER_MILLI
284 /// Returns the fractional part of this `Duration`, in whole microseconds.
286 /// This method does **not** return the length of the duration when
287 /// represented by microseconds. The returned number always represents a
288 /// fractional portion of a second (i.e., it is less than one million).
293 /// use std::time::Duration;
295 /// let duration = Duration::from_micros(1_234_567);
296 /// assert_eq!(duration.as_secs(), 1);
297 /// assert_eq!(duration.subsec_micros(), 234_567);
299 #[stable(feature = "duration_extras", since = "1.27.0")]
300 #[rustc_const_stable(feature = "duration_extras", since = "1.32.0")]
302 pub const fn subsec_micros(&self) -> u32 {
303 self.nanos / NANOS_PER_MICRO
306 /// Returns the fractional part of this `Duration`, in nanoseconds.
308 /// This method does **not** return the length of the duration when
309 /// represented by nanoseconds. The returned number always represents a
310 /// fractional portion of a second (i.e., it is less than one billion).
315 /// use std::time::Duration;
317 /// let duration = Duration::from_millis(5010);
318 /// assert_eq!(duration.as_secs(), 5);
319 /// assert_eq!(duration.subsec_nanos(), 10_000_000);
321 #[stable(feature = "duration", since = "1.3.0")]
322 #[rustc_const_stable(feature = "duration", since = "1.32.0")]
324 pub const fn subsec_nanos(&self) -> u32 {
328 /// Returns the total number of whole milliseconds contained by this `Duration`.
333 /// use std::time::Duration;
335 /// let duration = Duration::new(5, 730023852);
336 /// assert_eq!(duration.as_millis(), 5730);
338 #[stable(feature = "duration_as_u128", since = "1.33.0")]
339 #[rustc_const_stable(feature = "duration_as_u128", since = "1.33.0")]
341 pub const fn as_millis(&self) -> u128 {
342 self.secs as u128 * MILLIS_PER_SEC as u128 + (self.nanos / NANOS_PER_MILLI) as u128
345 /// Returns the total number of whole microseconds contained by this `Duration`.
350 /// use std::time::Duration;
352 /// let duration = Duration::new(5, 730023852);
353 /// assert_eq!(duration.as_micros(), 5730023);
355 #[stable(feature = "duration_as_u128", since = "1.33.0")]
356 #[rustc_const_stable(feature = "duration_as_u128", since = "1.33.0")]
358 pub const fn as_micros(&self) -> u128 {
359 self.secs as u128 * MICROS_PER_SEC as u128 + (self.nanos / NANOS_PER_MICRO) as u128
362 /// Returns the total number of nanoseconds contained by this `Duration`.
367 /// use std::time::Duration;
369 /// let duration = Duration::new(5, 730023852);
370 /// assert_eq!(duration.as_nanos(), 5730023852);
372 #[stable(feature = "duration_as_u128", since = "1.33.0")]
373 #[rustc_const_stable(feature = "duration_as_u128", since = "1.33.0")]
375 pub const fn as_nanos(&self) -> u128 {
376 self.secs as u128 * NANOS_PER_SEC as u128 + self.nanos as u128
379 /// Checked `Duration` addition. Computes `self + other`, returning [`None`]
380 /// if overflow occurred.
382 /// [`None`]: ../../std/option/enum.Option.html#variant.None
389 /// use std::time::Duration;
391 /// assert_eq!(Duration::new(0, 0).checked_add(Duration::new(0, 1)), Some(Duration::new(0, 1)));
392 /// assert_eq!(Duration::new(1, 0).checked_add(Duration::new(std::u64::MAX, 0)), None);
394 #[stable(feature = "duration_checked_ops", since = "1.16.0")]
396 pub fn checked_add(self, rhs: Duration) -> Option<Duration> {
397 if let Some(mut secs) = self.secs.checked_add(rhs.secs) {
398 let mut nanos = self.nanos + rhs.nanos;
399 if nanos >= NANOS_PER_SEC {
400 nanos -= NANOS_PER_SEC;
401 if let Some(new_secs) = secs.checked_add(1) {
407 debug_assert!(nanos < NANOS_PER_SEC);
408 Some(Duration { secs, nanos })
414 /// Checked `Duration` subtraction. Computes `self - other`, returning [`None`]
415 /// if the result would be negative or if overflow occurred.
417 /// [`None`]: ../../std/option/enum.Option.html#variant.None
424 /// use std::time::Duration;
426 /// assert_eq!(Duration::new(0, 1).checked_sub(Duration::new(0, 0)), Some(Duration::new(0, 1)));
427 /// assert_eq!(Duration::new(0, 0).checked_sub(Duration::new(0, 1)), None);
429 #[stable(feature = "duration_checked_ops", since = "1.16.0")]
431 pub fn checked_sub(self, rhs: Duration) -> Option<Duration> {
432 if let Some(mut secs) = self.secs.checked_sub(rhs.secs) {
433 let nanos = if self.nanos >= rhs.nanos {
434 self.nanos - rhs.nanos
436 if let Some(sub_secs) = secs.checked_sub(1) {
438 self.nanos + NANOS_PER_SEC - rhs.nanos
443 debug_assert!(nanos < NANOS_PER_SEC);
444 Some(Duration { secs, nanos })
450 /// Checked `Duration` multiplication. Computes `self * other`, returning
451 /// [`None`] if overflow occurred.
453 /// [`None`]: ../../std/option/enum.Option.html#variant.None
460 /// use std::time::Duration;
462 /// assert_eq!(Duration::new(0, 500_000_001).checked_mul(2), Some(Duration::new(1, 2)));
463 /// assert_eq!(Duration::new(std::u64::MAX - 1, 0).checked_mul(2), None);
465 #[stable(feature = "duration_checked_ops", since = "1.16.0")]
467 pub fn checked_mul(self, rhs: u32) -> Option<Duration> {
468 // Multiply nanoseconds as u64, because it cannot overflow that way.
469 let total_nanos = self.nanos as u64 * rhs as u64;
470 let extra_secs = total_nanos / (NANOS_PER_SEC as u64);
471 let nanos = (total_nanos % (NANOS_PER_SEC as u64)) as u32;
473 self.secs.checked_mul(rhs as u64).and_then(|s| s.checked_add(extra_secs))
475 debug_assert!(nanos < NANOS_PER_SEC);
476 Some(Duration { secs, nanos })
482 /// Checked `Duration` division. Computes `self / other`, returning [`None`]
485 /// [`None`]: ../../std/option/enum.Option.html#variant.None
492 /// use std::time::Duration;
494 /// assert_eq!(Duration::new(2, 0).checked_div(2), Some(Duration::new(1, 0)));
495 /// assert_eq!(Duration::new(1, 0).checked_div(2), Some(Duration::new(0, 500_000_000)));
496 /// assert_eq!(Duration::new(2, 0).checked_div(0), None);
498 #[stable(feature = "duration_checked_ops", since = "1.16.0")]
500 pub fn checked_div(self, rhs: u32) -> Option<Duration> {
502 let secs = self.secs / (rhs as u64);
503 let carry = self.secs - secs * (rhs as u64);
504 let extra_nanos = carry * (NANOS_PER_SEC as u64) / (rhs as u64);
505 let nanos = self.nanos / rhs + (extra_nanos as u32);
506 debug_assert!(nanos < NANOS_PER_SEC);
507 Some(Duration { secs, nanos })
513 /// Returns the number of seconds contained by this `Duration` as `f64`.
515 /// The returned value does include the fractional (nanosecond) part of the duration.
519 /// use std::time::Duration;
521 /// let dur = Duration::new(2, 700_000_000);
522 /// assert_eq!(dur.as_secs_f64(), 2.7);
524 #[stable(feature = "duration_float", since = "1.38.0")]
526 pub fn as_secs_f64(&self) -> f64 {
527 (self.secs as f64) + (self.nanos as f64) / (NANOS_PER_SEC as f64)
530 /// Returns the number of seconds contained by this `Duration` as `f32`.
532 /// The returned value does include the fractional (nanosecond) part of the duration.
536 /// use std::time::Duration;
538 /// let dur = Duration::new(2, 700_000_000);
539 /// assert_eq!(dur.as_secs_f32(), 2.7);
541 #[stable(feature = "duration_float", since = "1.38.0")]
543 pub fn as_secs_f32(&self) -> f32 {
544 (self.secs as f32) + (self.nanos as f32) / (NANOS_PER_SEC as f32)
547 /// Creates a new `Duration` from the specified number of seconds represented
551 /// This constructor will panic if `secs` is not finite, negative or overflows `Duration`.
555 /// use std::time::Duration;
557 /// let dur = Duration::from_secs_f64(2.7);
558 /// assert_eq!(dur, Duration::new(2, 700_000_000));
560 #[stable(feature = "duration_float", since = "1.38.0")]
562 pub fn from_secs_f64(secs: f64) -> Duration {
563 const MAX_NANOS_F64: f64 = ((u64::MAX as u128 + 1) * (NANOS_PER_SEC as u128)) as f64;
564 let nanos = secs * (NANOS_PER_SEC as f64);
565 if !nanos.is_finite() {
566 panic!("got non-finite value when converting float to duration");
568 if nanos >= MAX_NANOS_F64 {
569 panic!("overflow when converting float to duration");
572 panic!("underflow when converting float to duration");
574 let nanos = nanos as u128;
576 secs: (nanos / (NANOS_PER_SEC as u128)) as u64,
577 nanos: (nanos % (NANOS_PER_SEC as u128)) as u32,
581 /// Creates a new `Duration` from the specified number of seconds represented
585 /// This constructor will panic if `secs` is not finite, negative or overflows `Duration`.
589 /// use std::time::Duration;
591 /// let dur = Duration::from_secs_f32(2.7);
592 /// assert_eq!(dur, Duration::new(2, 700_000_000));
594 #[stable(feature = "duration_float", since = "1.38.0")]
596 pub fn from_secs_f32(secs: f32) -> Duration {
597 const MAX_NANOS_F32: f32 = ((u64::MAX as u128 + 1) * (NANOS_PER_SEC as u128)) as f32;
598 let nanos = secs * (NANOS_PER_SEC as f32);
599 if !nanos.is_finite() {
600 panic!("got non-finite value when converting float to duration");
602 if nanos >= MAX_NANOS_F32 {
603 panic!("overflow when converting float to duration");
606 panic!("underflow when converting float to duration");
608 let nanos = nanos as u128;
610 secs: (nanos / (NANOS_PER_SEC as u128)) as u64,
611 nanos: (nanos % (NANOS_PER_SEC as u128)) as u32,
615 /// Multiplies `Duration` by `f64`.
618 /// This method will panic if result is not finite, negative or overflows `Duration`.
622 /// use std::time::Duration;
624 /// let dur = Duration::new(2, 700_000_000);
625 /// assert_eq!(dur.mul_f64(3.14), Duration::new(8, 478_000_000));
626 /// assert_eq!(dur.mul_f64(3.14e5), Duration::new(847_800, 0));
628 #[stable(feature = "duration_float", since = "1.38.0")]
630 pub fn mul_f64(self, rhs: f64) -> Duration {
631 Duration::from_secs_f64(rhs * self.as_secs_f64())
634 /// Multiplies `Duration` by `f32`.
637 /// This method will panic if result is not finite, negative or overflows `Duration`.
641 /// use std::time::Duration;
643 /// let dur = Duration::new(2, 700_000_000);
644 /// // note that due to rounding errors result is slightly different
645 /// // from 8.478 and 847800.0
646 /// assert_eq!(dur.mul_f32(3.14), Duration::new(8, 478_000_640));
647 /// assert_eq!(dur.mul_f32(3.14e5), Duration::new(847799, 969_120_256));
649 #[stable(feature = "duration_float", since = "1.38.0")]
651 pub fn mul_f32(self, rhs: f32) -> Duration {
652 Duration::from_secs_f32(rhs * self.as_secs_f32())
655 /// Divide `Duration` by `f64`.
658 /// This method will panic if result is not finite, negative or overflows `Duration`.
662 /// use std::time::Duration;
664 /// let dur = Duration::new(2, 700_000_000);
665 /// assert_eq!(dur.div_f64(3.14), Duration::new(0, 859_872_611));
666 /// // note that truncation is used, not rounding
667 /// assert_eq!(dur.div_f64(3.14e5), Duration::new(0, 8_598));
669 #[stable(feature = "duration_float", since = "1.38.0")]
671 pub fn div_f64(self, rhs: f64) -> Duration {
672 Duration::from_secs_f64(self.as_secs_f64() / rhs)
675 /// Divide `Duration` by `f32`.
678 /// This method will panic if result is not finite, negative or overflows `Duration`.
682 /// use std::time::Duration;
684 /// let dur = Duration::new(2, 700_000_000);
685 /// // note that due to rounding errors result is slightly
686 /// // different from 0.859_872_611
687 /// assert_eq!(dur.div_f32(3.14), Duration::new(0, 859_872_576));
688 /// // note that truncation is used, not rounding
689 /// assert_eq!(dur.div_f32(3.14e5), Duration::new(0, 8_598));
691 #[stable(feature = "duration_float", since = "1.38.0")]
693 pub fn div_f32(self, rhs: f32) -> Duration {
694 Duration::from_secs_f32(self.as_secs_f32() / rhs)
697 /// Divide `Duration` by `Duration` and return `f64`.
701 /// #![feature(div_duration)]
702 /// use std::time::Duration;
704 /// let dur1 = Duration::new(2, 700_000_000);
705 /// let dur2 = Duration::new(5, 400_000_000);
706 /// assert_eq!(dur1.div_duration_f64(dur2), 0.5);
708 #[unstable(feature = "div_duration", issue = "63139")]
710 pub fn div_duration_f64(self, rhs: Duration) -> f64 {
711 self.as_secs_f64() / rhs.as_secs_f64()
714 /// Divide `Duration` by `Duration` and return `f32`.
718 /// #![feature(div_duration)]
719 /// use std::time::Duration;
721 /// let dur1 = Duration::new(2, 700_000_000);
722 /// let dur2 = Duration::new(5, 400_000_000);
723 /// assert_eq!(dur1.div_duration_f32(dur2), 0.5);
725 #[unstable(feature = "div_duration", issue = "63139")]
727 pub fn div_duration_f32(self, rhs: Duration) -> f32 {
728 self.as_secs_f32() / rhs.as_secs_f32()
732 #[stable(feature = "duration", since = "1.3.0")]
733 impl Add for Duration {
734 type Output = Duration;
736 fn add(self, rhs: Duration) -> Duration {
737 self.checked_add(rhs).expect("overflow when adding durations")
741 #[stable(feature = "time_augmented_assignment", since = "1.9.0")]
742 impl AddAssign for Duration {
743 fn add_assign(&mut self, rhs: Duration) {
748 #[stable(feature = "duration", since = "1.3.0")]
749 impl Sub for Duration {
750 type Output = Duration;
752 fn sub(self, rhs: Duration) -> Duration {
753 self.checked_sub(rhs).expect("overflow when subtracting durations")
757 #[stable(feature = "time_augmented_assignment", since = "1.9.0")]
758 impl SubAssign for Duration {
759 fn sub_assign(&mut self, rhs: Duration) {
764 #[stable(feature = "duration", since = "1.3.0")]
765 impl Mul<u32> for Duration {
766 type Output = Duration;
768 fn mul(self, rhs: u32) -> Duration {
769 self.checked_mul(rhs).expect("overflow when multiplying duration by scalar")
773 #[stable(feature = "symmetric_u32_duration_mul", since = "1.31.0")]
774 impl Mul<Duration> for u32 {
775 type Output = Duration;
777 fn mul(self, rhs: Duration) -> Duration {
782 #[stable(feature = "time_augmented_assignment", since = "1.9.0")]
783 impl MulAssign<u32> for Duration {
784 fn mul_assign(&mut self, rhs: u32) {
789 #[stable(feature = "duration", since = "1.3.0")]
790 impl Div<u32> for Duration {
791 type Output = Duration;
793 fn div(self, rhs: u32) -> Duration {
794 self.checked_div(rhs).expect("divide by zero error when dividing duration by scalar")
798 #[stable(feature = "time_augmented_assignment", since = "1.9.0")]
799 impl DivAssign<u32> for Duration {
800 fn div_assign(&mut self, rhs: u32) {
805 macro_rules! sum_durations {
807 let mut total_secs: u64 = 0;
808 let mut total_nanos: u64 = 0;
812 total_secs.checked_add(entry.secs).expect("overflow in iter::sum over durations");
813 total_nanos = match total_nanos.checked_add(entry.nanos as u64) {
816 total_secs = total_secs
817 .checked_add(total_nanos / NANOS_PER_SEC as u64)
818 .expect("overflow in iter::sum over durations");
819 (total_nanos % NANOS_PER_SEC as u64) + entry.nanos as u64
823 total_secs = total_secs
824 .checked_add(total_nanos / NANOS_PER_SEC as u64)
825 .expect("overflow in iter::sum over durations");
826 total_nanos = total_nanos % NANOS_PER_SEC as u64;
827 Duration { secs: total_secs, nanos: total_nanos as u32 }
831 #[stable(feature = "duration_sum", since = "1.16.0")]
832 impl Sum for Duration {
833 fn sum<I: Iterator<Item = Duration>>(iter: I) -> Duration {
838 #[stable(feature = "duration_sum", since = "1.16.0")]
839 impl<'a> Sum<&'a Duration> for Duration {
840 fn sum<I: Iterator<Item = &'a Duration>>(iter: I) -> Duration {
845 #[stable(feature = "duration_debug_impl", since = "1.27.0")]
846 impl fmt::Debug for Duration {
847 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
848 /// Formats a floating point number in decimal notation.
850 /// The number is given as the `integer_part` and a fractional part.
851 /// The value of the fractional part is `fractional_part / divisor`. So
852 /// `integer_part` = 3, `fractional_part` = 12 and `divisor` = 100
853 /// represents the number `3.012`. Trailing zeros are omitted.
855 /// `divisor` must not be above 100_000_000. It also should be a power
856 /// of 10, everything else doesn't make sense. `fractional_part` has
857 /// to be less than `10 * divisor`!
859 f: &mut fmt::Formatter<'_>,
860 mut integer_part: u64,
861 mut fractional_part: u32,
864 // Encode the fractional part into a temporary buffer. The buffer
865 // only need to hold 9 elements, because `fractional_part` has to
866 // be smaller than 10^9. The buffer is prefilled with '0' digits
867 // to simplify the code below.
868 let mut buf = [b'0'; 9];
870 // The next digit is written at this position
873 // We keep writing digits into the buffer while there are non-zero
874 // digits left and we haven't written enough digits yet.
875 while fractional_part > 0 && pos < f.precision().unwrap_or(9) {
876 // Write new digit into the buffer
877 buf[pos] = b'0' + (fractional_part / divisor) as u8;
879 fractional_part %= divisor;
884 // If a precision < 9 was specified, there may be some non-zero
885 // digits left that weren't written into the buffer. In that case we
886 // need to perform rounding to match the semantics of printing
887 // normal floating point numbers. However, we only need to do work
888 // when rounding up. This happens if the first digit of the
889 // remaining ones is >= 5.
890 if fractional_part > 0 && fractional_part >= divisor * 5 {
891 // Round up the number contained in the buffer. We go through
892 // the buffer backwards and keep track of the carry.
893 let mut rev_pos = pos;
894 let mut carry = true;
895 while carry && rev_pos > 0 {
898 // If the digit in the buffer is not '9', we just need to
899 // increment it and can stop then (since we don't have a
900 // carry anymore). Otherwise, we set it to '0' (overflow)
902 if buf[rev_pos] < b'9' {
910 // If we still have the carry bit set, that means that we set
911 // the whole buffer to '0's and need to increment the integer
918 // Determine the end of the buffer: if precision is set, we just
919 // use as many digits from the buffer (capped to 9). If it isn't
920 // set, we only use all digits up to the last non-zero one.
921 let end = f.precision().map(|p| crate::cmp::min(p, 9)).unwrap_or(pos);
923 // If we haven't emitted a single fractional digit and the precision
924 // wasn't set to a non-zero value, we don't print the decimal point.
926 write!(f, "{}", integer_part)
928 // SAFETY: We are only writing ASCII digits into the buffer and it was
929 // initialized with '0's, so it contains valid UTF8.
930 let s = unsafe { crate::str::from_utf8_unchecked(&buf[..end]) };
932 // If the user request a precision > 9, we pad '0's at the end.
933 let w = f.precision().unwrap_or(pos);
934 write!(f, "{}.{:0<width$}", integer_part, s, width = w)
938 // Print leading '+' sign if requested
944 fmt_decimal(f, self.secs, self.nanos, 100_000_000)?;
946 } else if self.nanos >= 1_000_000 {
947 fmt_decimal(f, self.nanos as u64 / 1_000_000, self.nanos % 1_000_000, 100_000)?;
949 } else if self.nanos >= 1_000 {
950 fmt_decimal(f, self.nanos as u64 / 1_000, self.nanos % 1_000, 100)?;
953 fmt_decimal(f, self.nanos as u64, 0, 1)?;