1 // Copyright 2012-2017 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
10 #![stable(feature = "duration_core", since = "1.24.0")]
12 //! Temporal quantification.
17 //! use std::time::Duration;
19 //! let five_seconds = Duration::new(5, 0);
20 //! // both declarations are equivalent
21 //! assert_eq!(Duration::new(5, 0), Duration::from_secs(5));
25 use ops::{Add, Sub, Mul, Div, AddAssign, SubAssign, MulAssign, DivAssign};
27 const NANOS_PER_SEC: u32 = 1_000_000_000;
28 const NANOS_PER_MILLI: u32 = 1_000_000;
29 const NANOS_PER_MICRO: u32 = 1_000;
30 const MILLIS_PER_SEC: u64 = 1_000;
31 const MICROS_PER_SEC: u64 = 1_000_000;
33 /// A `Duration` type to represent a span of time, typically used for system
36 /// Each `Duration` is composed of a whole number of seconds and a fractional part
37 /// represented in nanoseconds. If the underlying system does not support
38 /// nanosecond-level precision, APIs binding a system timeout will typically round up
39 /// the number of nanoseconds.
41 /// `Duration`s implement many common traits, including [`Add`], [`Sub`], and other
44 /// [`Add`]: ../../std/ops/trait.Add.html
45 /// [`Sub`]: ../../std/ops/trait.Sub.html
46 /// [`ops`]: ../../std/ops/index.html
51 /// use std::time::Duration;
53 /// let five_seconds = Duration::new(5, 0);
54 /// let five_seconds_and_five_nanos = five_seconds + Duration::new(0, 5);
56 /// assert_eq!(five_seconds_and_five_nanos.as_secs(), 5);
57 /// assert_eq!(five_seconds_and_five_nanos.subsec_nanos(), 5);
59 /// let ten_millis = Duration::from_millis(10);
61 #[stable(feature = "duration_core", since = "1.24.0")]
62 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Debug, Hash, Default)]
65 nanos: u32, // Always 0 <= nanos < NANOS_PER_SEC
69 /// Creates a new `Duration` from the specified number of whole seconds and
70 /// additional nanoseconds.
72 /// If the number of nanoseconds is greater than 1 billion (the number of
73 /// nanoseconds in a second), then it will carry over into the seconds provided.
77 /// This constructor will panic if the carry from the nanoseconds overflows
78 /// the seconds counter.
83 /// use std::time::Duration;
85 /// let five_seconds = Duration::new(5, 0);
87 #[stable(feature = "duration", since = "1.3.0")]
89 pub fn new(secs: u64, nanos: u32) -> Duration {
90 let secs = secs.checked_add((nanos / NANOS_PER_SEC) as u64)
91 .expect("overflow in Duration::new");
92 let nanos = nanos % NANOS_PER_SEC;
93 Duration { secs: secs, nanos: nanos }
96 /// Creates a new `Duration` from the specified number of whole seconds.
101 /// use std::time::Duration;
103 /// let duration = Duration::from_secs(5);
105 /// assert_eq!(5, duration.as_secs());
106 /// assert_eq!(0, duration.subsec_nanos());
108 #[stable(feature = "duration", since = "1.3.0")]
110 pub const fn from_secs(secs: u64) -> Duration {
111 Duration { secs: secs, nanos: 0 }
114 /// Creates a new `Duration` from the specified number of milliseconds.
119 /// use std::time::Duration;
121 /// let duration = Duration::from_millis(2569);
123 /// assert_eq!(2, duration.as_secs());
124 /// assert_eq!(569_000_000, duration.subsec_nanos());
126 #[stable(feature = "duration", since = "1.3.0")]
128 pub const fn from_millis(millis: u64) -> Duration {
130 secs: millis / MILLIS_PER_SEC,
131 nanos: ((millis % MILLIS_PER_SEC) as u32) * NANOS_PER_MILLI,
135 /// Creates a new `Duration` from the specified number of microseconds.
140 /// #![feature(duration_from_micros)]
141 /// use std::time::Duration;
143 /// let duration = Duration::from_micros(1_000_002);
145 /// assert_eq!(1, duration.as_secs());
146 /// assert_eq!(2000, duration.subsec_nanos());
148 #[unstable(feature = "duration_from_micros", issue = "44400")]
150 pub const fn from_micros(micros: u64) -> Duration {
152 secs: micros / MICROS_PER_SEC,
153 nanos: ((micros % MICROS_PER_SEC) as u32) * NANOS_PER_MICRO,
157 /// Creates a new `Duration` from the specified number of nanoseconds.
162 /// #![feature(duration_extras)]
163 /// use std::time::Duration;
165 /// let duration = Duration::from_nanos(1_000_000_123);
167 /// assert_eq!(1, duration.as_secs());
168 /// assert_eq!(123, duration.subsec_nanos());
170 #[unstable(feature = "duration_extras", issue = "46507")]
172 pub const fn from_nanos(nanos: u64) -> Duration {
174 secs: nanos / (NANOS_PER_SEC as u64),
175 nanos: (nanos % (NANOS_PER_SEC as u64)) as u32,
179 /// Returns the number of _whole_ seconds contained by this `Duration`.
181 /// The returned value does not include the fractional (nanosecond) part of the
182 /// duration, which can be obtained using [`subsec_nanos`].
187 /// use std::time::Duration;
189 /// let duration = Duration::new(5, 730023852);
190 /// assert_eq!(duration.as_secs(), 5);
193 /// To determine the total number of seconds represented by the `Duration`,
194 /// use `as_secs` in combination with [`subsec_nanos`]:
197 /// use std::time::Duration;
199 /// let duration = Duration::new(5, 730023852);
201 /// assert_eq!(5.730023852,
202 /// duration.as_secs() as f64
203 /// + duration.subsec_nanos() as f64 * 1e-9);
206 /// [`subsec_nanos`]: #method.subsec_nanos
207 #[stable(feature = "duration", since = "1.3.0")]
209 pub fn as_secs(&self) -> u64 { self.secs }
211 /// Returns the fractional part of this `Duration`, in milliseconds.
213 /// This method does **not** return the length of the duration when
214 /// represented by milliseconds. The returned number always represents a
215 /// fractional portion of a second (i.e. it is less than one thousand).
220 /// #![feature(duration_extras)]
221 /// use std::time::Duration;
223 /// let duration = Duration::from_millis(5432);
224 /// assert_eq!(duration.as_secs(), 5);
225 /// assert_eq!(duration.subsec_millis(), 432);
227 #[unstable(feature = "duration_extras", issue = "46507")]
229 pub fn subsec_millis(&self) -> u32 { self.nanos / NANOS_PER_MILLI }
231 /// Returns the fractional part of this `Duration`, in microseconds.
233 /// This method does **not** return the length of the duration when
234 /// represented by microseconds. The returned number always represents a
235 /// fractional portion of a second (i.e. it is less than one million).
240 /// #![feature(duration_extras, duration_from_micros)]
241 /// use std::time::Duration;
243 /// let duration = Duration::from_micros(1_234_567);
244 /// assert_eq!(duration.as_secs(), 1);
245 /// assert_eq!(duration.subsec_micros(), 234_567);
247 #[unstable(feature = "duration_extras", issue = "46507")]
249 pub fn subsec_micros(&self) -> u32 { self.nanos / NANOS_PER_MICRO }
251 /// Returns the fractional part of this `Duration`, in nanoseconds.
253 /// This method does **not** return the length of the duration when
254 /// represented by nanoseconds. The returned number always represents a
255 /// fractional portion of a second (i.e. it is less than one billion).
260 /// use std::time::Duration;
262 /// let duration = Duration::from_millis(5010);
263 /// assert_eq!(duration.as_secs(), 5);
264 /// assert_eq!(duration.subsec_nanos(), 10_000_000);
266 #[stable(feature = "duration", since = "1.3.0")]
268 pub fn subsec_nanos(&self) -> u32 { self.nanos }
270 /// Checked `Duration` addition. Computes `self + other`, returning [`None`]
271 /// if overflow occurred.
273 /// [`None`]: ../../std/option/enum.Option.html#variant.None
280 /// use std::time::Duration;
282 /// assert_eq!(Duration::new(0, 0).checked_add(Duration::new(0, 1)), Some(Duration::new(0, 1)));
283 /// assert_eq!(Duration::new(1, 0).checked_add(Duration::new(std::u64::MAX, 0)), None);
285 #[stable(feature = "duration_checked_ops", since = "1.16.0")]
287 pub fn checked_add(self, rhs: Duration) -> Option<Duration> {
288 if let Some(mut secs) = self.secs.checked_add(rhs.secs) {
289 let mut nanos = self.nanos + rhs.nanos;
290 if nanos >= NANOS_PER_SEC {
291 nanos -= NANOS_PER_SEC;
292 if let Some(new_secs) = secs.checked_add(1) {
298 debug_assert!(nanos < NANOS_PER_SEC);
308 /// Checked `Duration` subtraction. Computes `self - other`, returning [`None`]
309 /// if the result would be negative or if overflow occurred.
311 /// [`None`]: ../../std/option/enum.Option.html#variant.None
318 /// use std::time::Duration;
320 /// assert_eq!(Duration::new(0, 1).checked_sub(Duration::new(0, 0)), Some(Duration::new(0, 1)));
321 /// assert_eq!(Duration::new(0, 0).checked_sub(Duration::new(0, 1)), None);
323 #[stable(feature = "duration_checked_ops", since = "1.16.0")]
325 pub fn checked_sub(self, rhs: Duration) -> Option<Duration> {
326 if let Some(mut secs) = self.secs.checked_sub(rhs.secs) {
327 let nanos = if self.nanos >= rhs.nanos {
328 self.nanos - rhs.nanos
330 if let Some(sub_secs) = secs.checked_sub(1) {
332 self.nanos + NANOS_PER_SEC - rhs.nanos
337 debug_assert!(nanos < NANOS_PER_SEC);
338 Some(Duration { secs: secs, nanos: nanos })
344 /// Checked `Duration` multiplication. Computes `self * other`, returning
345 /// [`None`] if overflow occurred.
347 /// [`None`]: ../../std/option/enum.Option.html#variant.None
354 /// use std::time::Duration;
356 /// assert_eq!(Duration::new(0, 500_000_001).checked_mul(2), Some(Duration::new(1, 2)));
357 /// assert_eq!(Duration::new(std::u64::MAX - 1, 0).checked_mul(2), None);
359 #[stable(feature = "duration_checked_ops", since = "1.16.0")]
361 pub fn checked_mul(self, rhs: u32) -> Option<Duration> {
362 // Multiply nanoseconds as u64, because it cannot overflow that way.
363 let total_nanos = self.nanos as u64 * rhs as u64;
364 let extra_secs = total_nanos / (NANOS_PER_SEC as u64);
365 let nanos = (total_nanos % (NANOS_PER_SEC as u64)) as u32;
366 if let Some(secs) = self.secs
367 .checked_mul(rhs as u64)
368 .and_then(|s| s.checked_add(extra_secs)) {
369 debug_assert!(nanos < NANOS_PER_SEC);
379 /// Checked `Duration` division. Computes `self / other`, returning [`None`]
382 /// [`None`]: ../../std/option/enum.Option.html#variant.None
389 /// use std::time::Duration;
391 /// assert_eq!(Duration::new(2, 0).checked_div(2), Some(Duration::new(1, 0)));
392 /// assert_eq!(Duration::new(1, 0).checked_div(2), Some(Duration::new(0, 500_000_000)));
393 /// assert_eq!(Duration::new(2, 0).checked_div(0), None);
395 #[stable(feature = "duration_checked_ops", since = "1.16.0")]
397 pub fn checked_div(self, rhs: u32) -> Option<Duration> {
399 let secs = self.secs / (rhs as u64);
400 let carry = self.secs - secs * (rhs as u64);
401 let extra_nanos = carry * (NANOS_PER_SEC as u64) / (rhs as u64);
402 let nanos = self.nanos / rhs + (extra_nanos as u32);
403 debug_assert!(nanos < NANOS_PER_SEC);
404 Some(Duration { secs: secs, nanos: nanos })
411 #[stable(feature = "duration", since = "1.3.0")]
412 impl Add for Duration {
413 type Output = Duration;
415 fn add(self, rhs: Duration) -> Duration {
416 self.checked_add(rhs).expect("overflow when adding durations")
420 #[stable(feature = "time_augmented_assignment", since = "1.9.0")]
421 impl AddAssign for Duration {
422 fn add_assign(&mut self, rhs: Duration) {
427 #[stable(feature = "duration", since = "1.3.0")]
428 impl Sub for Duration {
429 type Output = Duration;
431 fn sub(self, rhs: Duration) -> Duration {
432 self.checked_sub(rhs).expect("overflow when subtracting durations")
436 #[stable(feature = "time_augmented_assignment", since = "1.9.0")]
437 impl SubAssign for Duration {
438 fn sub_assign(&mut self, rhs: Duration) {
443 #[stable(feature = "duration", since = "1.3.0")]
444 impl Mul<u32> for Duration {
445 type Output = Duration;
447 fn mul(self, rhs: u32) -> Duration {
448 self.checked_mul(rhs).expect("overflow when multiplying duration by scalar")
452 #[stable(feature = "time_augmented_assignment", since = "1.9.0")]
453 impl MulAssign<u32> for Duration {
454 fn mul_assign(&mut self, rhs: u32) {
459 #[stable(feature = "duration", since = "1.3.0")]
460 impl Div<u32> for Duration {
461 type Output = Duration;
463 fn div(self, rhs: u32) -> Duration {
464 self.checked_div(rhs).expect("divide by zero error when dividing duration by scalar")
468 #[stable(feature = "time_augmented_assignment", since = "1.9.0")]
469 impl DivAssign<u32> for Duration {
470 fn div_assign(&mut self, rhs: u32) {
475 #[stable(feature = "duration_sum", since = "1.16.0")]
476 impl Sum for Duration {
477 fn sum<I: Iterator<Item=Duration>>(iter: I) -> Duration {
478 iter.fold(Duration::new(0, 0), |a, b| a + b)
482 #[stable(feature = "duration_sum", since = "1.16.0")]
483 impl<'a> Sum<&'a Duration> for Duration {
484 fn sum<I: Iterator<Item=&'a Duration>>(iter: I) -> Duration {
485 iter.fold(Duration::new(0, 0), |a, b| a + *b)
495 assert!(Duration::from_secs(1) != Duration::from_secs(0));
496 assert_eq!(Duration::from_secs(1) + Duration::from_secs(2),
497 Duration::from_secs(3));
498 assert_eq!(Duration::from_millis(10) + Duration::from_secs(4),
499 Duration::new(4, 10 * 1_000_000));
500 assert_eq!(Duration::from_millis(4000), Duration::new(4, 0));
505 assert_eq!(Duration::new(0, 0).as_secs(), 0);
506 assert_eq!(Duration::from_secs(1).as_secs(), 1);
507 assert_eq!(Duration::from_millis(999).as_secs(), 0);
508 assert_eq!(Duration::from_millis(1001).as_secs(), 1);
513 assert_eq!(Duration::new(0, 0).subsec_nanos(), 0);
514 assert_eq!(Duration::new(0, 5).subsec_nanos(), 5);
515 assert_eq!(Duration::new(0, 1_000_000_001).subsec_nanos(), 1);
516 assert_eq!(Duration::from_secs(1).subsec_nanos(), 0);
517 assert_eq!(Duration::from_millis(999).subsec_nanos(), 999 * 1_000_000);
518 assert_eq!(Duration::from_millis(1001).subsec_nanos(), 1 * 1_000_000);
523 assert_eq!(Duration::new(0, 0) + Duration::new(0, 1),
524 Duration::new(0, 1));
525 assert_eq!(Duration::new(0, 500_000_000) + Duration::new(0, 500_000_001),
526 Duration::new(1, 1));
531 assert_eq!(Duration::new(0, 0).checked_add(Duration::new(0, 1)),
532 Some(Duration::new(0, 1)));
533 assert_eq!(Duration::new(0, 500_000_000).checked_add(Duration::new(0, 500_000_001)),
534 Some(Duration::new(1, 1)));
535 assert_eq!(Duration::new(1, 0).checked_add(Duration::new(::u64::MAX, 0)), None);
540 assert_eq!(Duration::new(0, 1) - Duration::new(0, 0),
541 Duration::new(0, 1));
542 assert_eq!(Duration::new(0, 500_000_001) - Duration::new(0, 500_000_000),
543 Duration::new(0, 1));
544 assert_eq!(Duration::new(1, 0) - Duration::new(0, 1),
545 Duration::new(0, 999_999_999));
550 let zero = Duration::new(0, 0);
551 let one_nano = Duration::new(0, 1);
552 let one_sec = Duration::new(1, 0);
553 assert_eq!(one_nano.checked_sub(zero), Some(Duration::new(0, 1)));
554 assert_eq!(one_sec.checked_sub(one_nano),
555 Some(Duration::new(0, 999_999_999)));
556 assert_eq!(zero.checked_sub(one_nano), None);
557 assert_eq!(zero.checked_sub(one_sec), None);
560 #[test] #[should_panic]
562 Duration::new(0, 0) - Duration::new(0, 1);
565 #[test] #[should_panic]
567 Duration::new(0, 0) - Duration::new(1, 0);
572 assert_eq!(Duration::new(0, 1) * 2, Duration::new(0, 2));
573 assert_eq!(Duration::new(1, 1) * 3, Duration::new(3, 3));
574 assert_eq!(Duration::new(0, 500_000_001) * 4, Duration::new(2, 4));
575 assert_eq!(Duration::new(0, 500_000_001) * 4000,
576 Duration::new(2000, 4000));
581 assert_eq!(Duration::new(0, 1).checked_mul(2), Some(Duration::new(0, 2)));
582 assert_eq!(Duration::new(1, 1).checked_mul(3), Some(Duration::new(3, 3)));
583 assert_eq!(Duration::new(0, 500_000_001).checked_mul(4), Some(Duration::new(2, 4)));
584 assert_eq!(Duration::new(0, 500_000_001).checked_mul(4000),
585 Some(Duration::new(2000, 4000)));
586 assert_eq!(Duration::new(::u64::MAX - 1, 0).checked_mul(2), None);
591 assert_eq!(Duration::new(0, 1) / 2, Duration::new(0, 0));
592 assert_eq!(Duration::new(1, 1) / 3, Duration::new(0, 333_333_333));
593 assert_eq!(Duration::new(99, 999_999_000) / 100,
594 Duration::new(0, 999_999_990));
599 assert_eq!(Duration::new(2, 0).checked_div(2), Some(Duration::new(1, 0)));
600 assert_eq!(Duration::new(1, 0).checked_div(2), Some(Duration::new(0, 500_000_000)));
601 assert_eq!(Duration::new(2, 0).checked_div(0), None);