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Diffstat (limited to 'src/libstd/time.rs')
| -rw-r--r-- | src/libstd/time.rs | 827 |
1 files changed, 0 insertions, 827 deletions
diff --git a/src/libstd/time.rs b/src/libstd/time.rs deleted file mode 100644 index 9f4fa89cd55..00000000000 --- a/src/libstd/time.rs +++ /dev/null @@ -1,827 +0,0 @@ -//! 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)); -//! ``` - -#![stable(feature = "time", since = "1.3.0")] - -use crate::cmp; -use crate::error::Error; -use crate::fmt; -use crate::ops::{Add, AddAssign, Sub, SubAssign}; -use crate::sys::time; -use crate::sys_common::mutex::Mutex; -use crate::sys_common::FromInner; - -#[stable(feature = "time", since = "1.3.0")] -pub use core::time::Duration; - -/// A measurement of a monotonically nondecreasing clock. -/// Opaque and useful only with `Duration`. -/// -/// Instants are always guaranteed to be no less than any previously measured -/// instant when created, and are often useful for tasks such as measuring -/// benchmarks or timing how long an operation takes. -/// -/// Note, however, that instants are not guaranteed to be **steady**. In other -/// words, each tick of the underlying clock may not be the same length (e.g. -/// some seconds may be longer than others). An instant may jump forwards or -/// experience time dilation (slow down or speed up), but it will never go -/// backwards. -/// -/// Instants are opaque types that can only be compared to one another. There is -/// no method to get "the number of seconds" from an instant. Instead, it only -/// allows measuring the duration between two instants (or comparing two -/// instants). -/// -/// The size of an `Instant` struct may vary depending on the target operating -/// system. -/// -/// Example: -/// -/// ```no_run -/// use std::time::{Duration, Instant}; -/// use std::thread::sleep; -/// -/// fn main() { -/// let now = Instant::now(); -/// -/// // we sleep for 2 seconds -/// sleep(Duration::new(2, 0)); -/// // it prints '2' -/// println!("{}", now.elapsed().as_secs()); -/// } -/// ``` -/// -/// # OS-specific behaviors -/// -/// An `Instant` is a wrapper around system-specific types and it may behave -/// differently depending on the underlying operating system. For example, -/// the following snippet is fine on Linux but panics on macOS: -/// -/// ```no_run -/// use std::time::{Instant, Duration}; -/// -/// let now = Instant::now(); -/// let max_nanoseconds = u64::MAX / 1_000_000_000; -/// let duration = Duration::new(max_nanoseconds, 0); -/// println!("{:?}", now + duration); -/// ``` -/// -/// # Underlying System calls -/// Currently, the following system calls are being used to get the current time using `now()`: -/// -/// | Platform | System call | -/// |:---------:|:--------------------------------------------------------------------:| -/// | CloudABI | [clock_time_get (Monotonic Clock)] | -/// | SGX | [`insecure_time` usercall]. More information on [timekeeping in SGX] | -/// | UNIX | [clock_gettime (Monotonic Clock)] | -/// | Darwin | [mach_absolute_time] | -/// | VXWorks | [clock_gettime (Monotonic Clock)] | -/// | WASI | [__wasi_clock_time_get (Monotonic Clock)] | -/// | Windows | [QueryPerformanceCounter] | -/// -/// [QueryPerformanceCounter]: https://docs.microsoft.com/en-us/windows/win32/api/profileapi/nf-profileapi-queryperformancecounter -/// [`insecure_time` usercall]: https://edp.fortanix.com/docs/api/fortanix_sgx_abi/struct.Usercalls.html#method.insecure_time -/// [timekeeping in SGX]: https://edp.fortanix.com/docs/concepts/rust-std/#codestdtimecode -/// [__wasi_clock_time_get (Monotonic Clock)]: https://github.com/WebAssembly/WASI/blob/master/phases/snapshot/docs.md#clock_time_get -/// [clock_gettime (Monotonic Clock)]: https://linux.die.net/man/3/clock_gettime -/// [mach_absolute_time]: https://developer.apple.com/library/archive/documentation/Darwin/Conceptual/KernelProgramming/services/services.html -/// [clock_time_get (Monotonic Clock)]: https://nuxi.nl/cloudabi/#clock_time_get -/// -/// **Disclaimer:** These system calls might change over time. -/// -#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)] -#[stable(feature = "time2", since = "1.8.0")] -pub struct Instant(time::Instant); - -/// A measurement of the system clock, useful for talking to -/// external entities like the file system or other processes. -/// -/// Distinct from the [`Instant`] type, this time measurement **is not -/// monotonic**. This means that you can save a file to the file system, then -/// save another file to the file system, **and the second file has a -/// `SystemTime` measurement earlier than the first**. In other words, an -/// operation that happens after another operation in real time may have an -/// earlier `SystemTime`! -/// -/// Consequently, comparing two `SystemTime` instances to learn about the -/// duration between them returns a [`Result`] instead of an infallible [`Duration`] -/// to indicate that this sort of time drift may happen and needs to be handled. -/// -/// Although a `SystemTime` cannot be directly inspected, the [`UNIX_EPOCH`] -/// constant is provided in this module as an anchor in time to learn -/// information about a `SystemTime`. By calculating the duration from this -/// fixed point in time, a `SystemTime` can be converted to a human-readable time, -/// or perhaps some other string representation. -/// -/// The size of a `SystemTime` struct may vary depending on the target operating -/// system. -/// -/// [`Instant`]: ../../std/time/struct.Instant.html -/// [`Result`]: ../../std/result/enum.Result.html -/// [`Duration`]: ../../std/time/struct.Duration.html -/// [`UNIX_EPOCH`]: ../../std/time/constant.UNIX_EPOCH.html -/// -/// Example: -/// -/// ```no_run -/// use std::time::{Duration, SystemTime}; -/// use std::thread::sleep; -/// -/// fn main() { -/// let now = SystemTime::now(); -/// -/// // we sleep for 2 seconds -/// sleep(Duration::new(2, 0)); -/// match now.elapsed() { -/// Ok(elapsed) => { -/// // it prints '2' -/// println!("{}", elapsed.as_secs()); -/// } -/// Err(e) => { -/// // an error occurred! -/// println!("Error: {:?}", e); -/// } -/// } -/// } -/// ``` -/// -/// # Underlying System calls -/// Currently, the following system calls are being used to get the current time using `now()`: -/// -/// | Platform | System call | -/// |:---------:|:--------------------------------------------------------------------:| -/// | CloudABI | [clock_time_get (Realtime Clock)] | -/// | SGX | [`insecure_time` usercall]. More information on [timekeeping in SGX] | -/// | UNIX | [clock_gettime (Realtime Clock)] | -/// | DARWIN | [gettimeofday] | -/// | VXWorks | [clock_gettime (Realtime Clock)] | -/// | WASI | [__wasi_clock_time_get (Realtime Clock)] | -/// | Windows | [GetSystemTimeAsFileTime] | -/// -/// [clock_time_get (Realtime Clock)]: https://nuxi.nl/cloudabi/#clock_time_get -/// [`insecure_time` usercall]: https://edp.fortanix.com/docs/api/fortanix_sgx_abi/struct.Usercalls.html#method.insecure_time -/// [timekeeping in SGX]: https://edp.fortanix.com/docs/concepts/rust-std/#codestdtimecode -/// [gettimeofday]: http://man7.org/linux/man-pages/man2/gettimeofday.2.html -/// [clock_gettime (Realtime Clock)]: https://linux.die.net/man/3/clock_gettime -/// [__wasi_clock_time_get (Realtime Clock)]: https://github.com/WebAssembly/WASI/blob/master/phases/snapshot/docs.md#clock_time_get -/// [GetSystemTimeAsFileTime]: https://docs.microsoft.com/en-us/windows/win32/api/sysinfoapi/nf-sysinfoapi-getsystemtimeasfiletime -/// -/// **Disclaimer:** These system calls might change over time. -/// -#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)] -#[stable(feature = "time2", since = "1.8.0")] -pub struct SystemTime(time::SystemTime); - -/// An error returned from the `duration_since` and `elapsed` methods on -/// `SystemTime`, used to learn how far in the opposite direction a system time -/// lies. -/// -/// # Examples -/// -/// ```no_run -/// use std::thread::sleep; -/// use std::time::{Duration, SystemTime}; -/// -/// let sys_time = SystemTime::now(); -/// sleep(Duration::from_secs(1)); -/// let new_sys_time = SystemTime::now(); -/// match sys_time.duration_since(new_sys_time) { -/// Ok(_) => {} -/// Err(e) => println!("SystemTimeError difference: {:?}", e.duration()), -/// } -/// ``` -#[derive(Clone, Debug)] -#[stable(feature = "time2", since = "1.8.0")] -pub struct SystemTimeError(Duration); - -impl Instant { - /// Returns an instant corresponding to "now". - /// - /// # Examples - /// - /// ``` - /// use std::time::Instant; - /// - /// let now = Instant::now(); - /// ``` - #[stable(feature = "time2", since = "1.8.0")] - pub fn now() -> Instant { - let os_now = time::Instant::now(); - - // And here we come upon a sad state of affairs. The whole point of - // `Instant` is that it's monotonically increasing. We've found in the - // wild, however, that it's not actually monotonically increasing for - // one reason or another. These appear to be OS and hardware level bugs, - // and there's not really a whole lot we can do about them. Here's a - // taste of what we've found: - // - // * #48514 - OpenBSD, x86_64 - // * #49281 - linux arm64 and s390x - // * #51648 - windows, x86 - // * #56560 - windows, x86_64, AWS - // * #56612 - windows, x86, vm (?) - // * #56940 - linux, arm64 - // * https://bugzilla.mozilla.org/show_bug.cgi?id=1487778 - a similar - // Firefox bug - // - // It seems that this just happens a lot in the wild. - // We're seeing panics across various platforms where consecutive calls - // to `Instant::now`, such as via the `elapsed` function, are panicking - // as they're going backwards. Placed here is a last-ditch effort to try - // to fix things up. We keep a global "latest now" instance which is - // returned instead of what the OS says if the OS goes backwards. - // - // To hopefully mitigate the impact of this, a few platforms are - // excluded as "these at least haven't gone backwards yet". - if time::Instant::actually_monotonic() { - return Instant(os_now); - } - - static LOCK: Mutex = Mutex::new(); - static mut LAST_NOW: time::Instant = time::Instant::zero(); - unsafe { - let _lock = LOCK.lock(); - let now = cmp::max(LAST_NOW, os_now); - LAST_NOW = now; - Instant(now) - } - } - - /// Returns the amount of time elapsed from another instant to this one. - /// - /// # Panics - /// - /// This function will panic if `earlier` is later than `self`. - /// - /// # Examples - /// - /// ```no_run - /// use std::time::{Duration, Instant}; - /// use std::thread::sleep; - /// - /// let now = Instant::now(); - /// sleep(Duration::new(1, 0)); - /// let new_now = Instant::now(); - /// println!("{:?}", new_now.duration_since(now)); - /// ``` - #[stable(feature = "time2", since = "1.8.0")] - pub fn duration_since(&self, earlier: Instant) -> Duration { - self.0.checked_sub_instant(&earlier.0).expect("supplied instant is later than self") - } - - /// Returns the amount of time elapsed from another instant to this one, - /// or None if that instant is later than this one. - /// - /// # Examples - /// - /// ```no_run - /// use std::time::{Duration, Instant}; - /// use std::thread::sleep; - /// - /// let now = Instant::now(); - /// sleep(Duration::new(1, 0)); - /// let new_now = Instant::now(); - /// println!("{:?}", new_now.checked_duration_since(now)); - /// println!("{:?}", now.checked_duration_since(new_now)); // None - /// ``` - #[stable(feature = "checked_duration_since", since = "1.39.0")] - pub fn checked_duration_since(&self, earlier: Instant) -> Option<Duration> { - self.0.checked_sub_instant(&earlier.0) - } - - /// Returns the amount of time elapsed from another instant to this one, - /// or zero duration if that instant is later than this one. - /// - /// # Examples - /// - /// ```no_run - /// use std::time::{Duration, Instant}; - /// use std::thread::sleep; - /// - /// let now = Instant::now(); - /// sleep(Duration::new(1, 0)); - /// let new_now = Instant::now(); - /// println!("{:?}", new_now.saturating_duration_since(now)); - /// println!("{:?}", now.saturating_duration_since(new_now)); // 0ns - /// ``` - #[stable(feature = "checked_duration_since", since = "1.39.0")] - pub fn saturating_duration_since(&self, earlier: Instant) -> Duration { - self.checked_duration_since(earlier).unwrap_or(Duration::new(0, 0)) - } - - /// Returns the amount of time elapsed since this instant was created. - /// - /// # Panics - /// - /// This function may panic if the current time is earlier than this - /// instant, which is something that can happen if an `Instant` is - /// produced synthetically. - /// - /// # Examples - /// - /// ```no_run - /// use std::thread::sleep; - /// use std::time::{Duration, Instant}; - /// - /// let instant = Instant::now(); - /// let three_secs = Duration::from_secs(3); - /// sleep(three_secs); - /// assert!(instant.elapsed() >= three_secs); - /// ``` - #[stable(feature = "time2", since = "1.8.0")] - pub fn elapsed(&self) -> Duration { - Instant::now() - *self - } - - /// Returns `Some(t)` where `t` is the time `self + duration` if `t` can be represented as - /// `Instant` (which means it's inside the bounds of the underlying data structure), `None` - /// otherwise. - #[stable(feature = "time_checked_add", since = "1.34.0")] - pub fn checked_add(&self, duration: Duration) -> Option<Instant> { - self.0.checked_add_duration(&duration).map(Instant) - } - - /// Returns `Some(t)` where `t` is the time `self - duration` if `t` can be represented as - /// `Instant` (which means it's inside the bounds of the underlying data structure), `None` - /// otherwise. - #[stable(feature = "time_checked_add", since = "1.34.0")] - pub fn checked_sub(&self, duration: Duration) -> Option<Instant> { - self.0.checked_sub_duration(&duration).map(Instant) - } -} - -#[stable(feature = "time2", since = "1.8.0")] -impl Add<Duration> for Instant { - type Output = Instant; - - /// # Panics - /// - /// This function may panic if the resulting point in time cannot be represented by the - /// underlying data structure. See [`checked_add`] for a version without panic. - /// - /// [`checked_add`]: ../../std/time/struct.Instant.html#method.checked_add - fn add(self, other: Duration) -> Instant { - self.checked_add(other).expect("overflow when adding duration to instant") - } -} - -#[stable(feature = "time_augmented_assignment", since = "1.9.0")] -impl AddAssign<Duration> for Instant { - fn add_assign(&mut self, other: Duration) { - *self = *self + other; - } -} - -#[stable(feature = "time2", since = "1.8.0")] -impl Sub<Duration> for Instant { - type Output = Instant; - - fn sub(self, other: Duration) -> Instant { - self.checked_sub(other).expect("overflow when subtracting duration from instant") - } -} - -#[stable(feature = "time_augmented_assignment", since = "1.9.0")] -impl SubAssign<Duration> for Instant { - fn sub_assign(&mut self, other: Duration) { - *self = *self - other; - } -} - -#[stable(feature = "time2", since = "1.8.0")] -impl Sub<Instant> for Instant { - type Output = Duration; - - fn sub(self, other: Instant) -> Duration { - self.duration_since(other) - } -} - -#[stable(feature = "time2", since = "1.8.0")] -impl fmt::Debug for Instant { - fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { - self.0.fmt(f) - } -} - -impl SystemTime { - /// An anchor in time which can be used to create new `SystemTime` instances or - /// learn about where in time a `SystemTime` lies. - /// - /// This constant is defined to be "1970-01-01 00:00:00 UTC" on all systems with - /// respect to the system clock. Using `duration_since` on an existing - /// `SystemTime` instance can tell how far away from this point in time a - /// measurement lies, and using `UNIX_EPOCH + duration` can be used to create a - /// `SystemTime` instance to represent another fixed point in time. - /// - /// # Examples - /// - /// ```no_run - /// use std::time::SystemTime; - /// - /// match SystemTime::now().duration_since(SystemTime::UNIX_EPOCH) { - /// Ok(n) => println!("1970-01-01 00:00:00 UTC was {} seconds ago!", n.as_secs()), - /// Err(_) => panic!("SystemTime before UNIX EPOCH!"), - /// } - /// ``` - #[stable(feature = "assoc_unix_epoch", since = "1.28.0")] - pub const UNIX_EPOCH: SystemTime = UNIX_EPOCH; - - /// Returns the system time corresponding to "now". - /// - /// # Examples - /// - /// ``` - /// use std::time::SystemTime; - /// - /// let sys_time = SystemTime::now(); - /// ``` - #[stable(feature = "time2", since = "1.8.0")] - pub fn now() -> SystemTime { - SystemTime(time::SystemTime::now()) - } - - /// Returns the amount of time elapsed from an earlier point in time. - /// - /// This function may fail because measurements taken earlier are not - /// guaranteed to always be before later measurements (due to anomalies such - /// as the system clock being adjusted either forwards or backwards). - /// [`Instant`] can be used to measure elapsed time without this risk of failure. - /// - /// If successful, [`Ok`]`(`[`Duration`]`)` is returned where the duration represents - /// the amount of time elapsed from the specified measurement to this one. - /// - /// Returns an [`Err`] if `earlier` is later than `self`, and the error - /// contains how far from `self` the time is. - /// - /// [`Ok`]: ../../std/result/enum.Result.html#variant.Ok - /// [`Duration`]: ../../std/time/struct.Duration.html - /// [`Err`]: ../../std/result/enum.Result.html#variant.Err - /// [`Instant`]: ../../std/time/struct.Instant.html - /// - /// # Examples - /// - /// ``` - /// use std::time::SystemTime; - /// - /// let sys_time = SystemTime::now(); - /// let difference = sys_time.duration_since(sys_time) - /// .expect("Clock may have gone backwards"); - /// println!("{:?}", difference); - /// ``` - #[stable(feature = "time2", since = "1.8.0")] - pub fn duration_since(&self, earlier: SystemTime) -> Result<Duration, SystemTimeError> { - self.0.sub_time(&earlier.0).map_err(SystemTimeError) - } - - /// Returns the difference between the clock time when this - /// system time was created, and the current clock time. - /// - /// This function may fail as the underlying system clock is susceptible to - /// drift and updates (e.g., the system clock could go backwards), so this - /// function may not always succeed. If successful, [`Ok`]`(`[`Duration`]`)` is - /// returned where the duration represents the amount of time elapsed from - /// this time measurement to the current time. - /// - /// To measure elapsed time reliably, use [`Instant`] instead. - /// - /// Returns an [`Err`] if `self` is later than the current system time, and - /// the error contains how far from the current system time `self` is. - /// - /// [`Ok`]: ../../std/result/enum.Result.html#variant.Ok - /// [`Duration`]: ../../std/time/struct.Duration.html - /// [`Err`]: ../../std/result/enum.Result.html#variant.Err - /// [`Instant`]: ../../std/time/struct.Instant.html - /// - /// # Examples - /// - /// ```no_run - /// use std::thread::sleep; - /// use std::time::{Duration, SystemTime}; - /// - /// let sys_time = SystemTime::now(); - /// let one_sec = Duration::from_secs(1); - /// sleep(one_sec); - /// assert!(sys_time.elapsed().unwrap() >= one_sec); - /// ``` - #[stable(feature = "time2", since = "1.8.0")] - pub fn elapsed(&self) -> Result<Duration, SystemTimeError> { - SystemTime::now().duration_since(*self) - } - - /// Returns `Some(t)` where `t` is the time `self + duration` if `t` can be represented as - /// `SystemTime` (which means it's inside the bounds of the underlying data structure), `None` - /// otherwise. - #[stable(feature = "time_checked_add", since = "1.34.0")] - pub fn checked_add(&self, duration: Duration) -> Option<SystemTime> { - self.0.checked_add_duration(&duration).map(SystemTime) - } - - /// Returns `Some(t)` where `t` is the time `self - duration` if `t` can be represented as - /// `SystemTime` (which means it's inside the bounds of the underlying data structure), `None` - /// otherwise. - #[stable(feature = "time_checked_add", since = "1.34.0")] - pub fn checked_sub(&self, duration: Duration) -> Option<SystemTime> { - self.0.checked_sub_duration(&duration).map(SystemTime) - } -} - -#[stable(feature = "time2", since = "1.8.0")] -impl Add<Duration> for SystemTime { - type Output = SystemTime; - - /// # Panics - /// - /// This function may panic if the resulting point in time cannot be represented by the - /// underlying data structure. See [`checked_add`] for a version without panic. - /// - /// [`checked_add`]: ../../std/time/struct.SystemTime.html#method.checked_add - fn add(self, dur: Duration) -> SystemTime { - self.checked_add(dur).expect("overflow when adding duration to instant") - } -} - -#[stable(feature = "time_augmented_assignment", since = "1.9.0")] -impl AddAssign<Duration> for SystemTime { - fn add_assign(&mut self, other: Duration) { - *self = *self + other; - } -} - -#[stable(feature = "time2", since = "1.8.0")] -impl Sub<Duration> for SystemTime { - type Output = SystemTime; - - fn sub(self, dur: Duration) -> SystemTime { - self.checked_sub(dur).expect("overflow when subtracting duration from instant") - } -} - -#[stable(feature = "time_augmented_assignment", since = "1.9.0")] -impl SubAssign<Duration> for SystemTime { - fn sub_assign(&mut self, other: Duration) { - *self = *self - other; - } -} - -#[stable(feature = "time2", since = "1.8.0")] -impl fmt::Debug for SystemTime { - fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { - self.0.fmt(f) - } -} - -/// An anchor in time which can be used to create new `SystemTime` instances or -/// learn about where in time a `SystemTime` lies. -/// -/// This constant is defined to be "1970-01-01 00:00:00 UTC" on all systems with -/// respect to the system clock. Using `duration_since` on an existing -/// [`SystemTime`] instance can tell how far away from this point in time a -/// measurement lies, and using `UNIX_EPOCH + duration` can be used to create a -/// [`SystemTime`] instance to represent another fixed point in time. -/// -/// [`SystemTime`]: ../../std/time/struct.SystemTime.html -/// -/// # Examples -/// -/// ```no_run -/// use std::time::{SystemTime, UNIX_EPOCH}; -/// -/// match SystemTime::now().duration_since(UNIX_EPOCH) { -/// Ok(n) => println!("1970-01-01 00:00:00 UTC was {} seconds ago!", n.as_secs()), -/// Err(_) => panic!("SystemTime before UNIX EPOCH!"), -/// } -/// ``` -#[stable(feature = "time2", since = "1.8.0")] -pub const UNIX_EPOCH: SystemTime = SystemTime(time::UNIX_EPOCH); - -impl SystemTimeError { - /// Returns the positive duration which represents how far forward the - /// second system time was from the first. - /// - /// A `SystemTimeError` is returned from the [`duration_since`] and [`elapsed`] - /// methods of [`SystemTime`] whenever the second system time represents a point later - /// in time than the `self` of the method call. - /// - /// [`duration_since`]: ../../std/time/struct.SystemTime.html#method.duration_since - /// [`elapsed`]: ../../std/time/struct.SystemTime.html#method.elapsed - /// [`SystemTime`]: ../../std/time/struct.SystemTime.html - /// - /// # Examples - /// - /// ```no_run - /// use std::thread::sleep; - /// use std::time::{Duration, SystemTime}; - /// - /// let sys_time = SystemTime::now(); - /// sleep(Duration::from_secs(1)); - /// let new_sys_time = SystemTime::now(); - /// match sys_time.duration_since(new_sys_time) { - /// Ok(_) => {} - /// Err(e) => println!("SystemTimeError difference: {:?}", e.duration()), - /// } - /// ``` - #[stable(feature = "time2", since = "1.8.0")] - pub fn duration(&self) -> Duration { - self.0 - } -} - -#[stable(feature = "time2", since = "1.8.0")] -impl Error for SystemTimeError { - #[allow(deprecated)] - fn description(&self) -> &str { - "other time was not earlier than self" - } -} - -#[stable(feature = "time2", since = "1.8.0")] -impl fmt::Display for SystemTimeError { - fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { - write!(f, "second time provided was later than self") - } -} - -impl FromInner<time::SystemTime> for SystemTime { - fn from_inner(time: time::SystemTime) -> SystemTime { - SystemTime(time) - } -} - -#[cfg(test)] -mod tests { - use super::{Duration, Instant, SystemTime, UNIX_EPOCH}; - - macro_rules! assert_almost_eq { - ($a:expr, $b:expr) => {{ - let (a, b) = ($a, $b); - if a != b { - let (a, b) = if a > b { (a, b) } else { (b, a) }; - assert!(a - Duration::new(0, 1000) <= b, "{:?} is not almost equal to {:?}", a, b); - } - }}; - } - - #[test] - fn instant_monotonic() { - let a = Instant::now(); - let b = Instant::now(); - assert!(b >= a); - } - - #[test] - fn instant_elapsed() { - let a = Instant::now(); - a.elapsed(); - } - - #[test] - fn instant_math() { - let a = Instant::now(); - let b = Instant::now(); - println!("a: {:?}", a); - println!("b: {:?}", b); - let dur = b.duration_since(a); - println!("dur: {:?}", dur); - assert_almost_eq!(b - dur, a); - assert_almost_eq!(a + dur, b); - - let second = Duration::new(1, 0); - assert_almost_eq!(a - second + second, a); - assert_almost_eq!(a.checked_sub(second).unwrap().checked_add(second).unwrap(), a); - - // checked_add_duration will not panic on overflow - let mut maybe_t = Some(Instant::now()); - let max_duration = Duration::from_secs(u64::MAX); - // in case `Instant` can store `>= now + max_duration`. - for _ in 0..2 { - maybe_t = maybe_t.and_then(|t| t.checked_add(max_duration)); - } - assert_eq!(maybe_t, None); - - // checked_add_duration calculates the right time and will work for another year - let year = Duration::from_secs(60 * 60 * 24 * 365); - assert_eq!(a + year, a.checked_add(year).unwrap()); - } - - #[test] - fn instant_math_is_associative() { - let now = Instant::now(); - let offset = Duration::from_millis(5); - // Changing the order of instant math shouldn't change the results, - // especially when the expression reduces to X + identity. - assert_eq!((now + offset) - now, (now - now) + offset); - } - - #[test] - #[should_panic] - fn instant_duration_since_panic() { - let a = Instant::now(); - (a - Duration::new(1, 0)).duration_since(a); - } - - #[test] - fn instant_checked_duration_since_nopanic() { - let now = Instant::now(); - let earlier = now - Duration::new(1, 0); - let later = now + Duration::new(1, 0); - assert_eq!(earlier.checked_duration_since(now), None); - assert_eq!(later.checked_duration_since(now), Some(Duration::new(1, 0))); - assert_eq!(now.checked_duration_since(now), Some(Duration::new(0, 0))); - } - - #[test] - fn instant_saturating_duration_since_nopanic() { - let a = Instant::now(); - let ret = (a - Duration::new(1, 0)).saturating_duration_since(a); - assert_eq!(ret, Duration::new(0, 0)); - } - - #[test] - fn system_time_math() { - let a = SystemTime::now(); - let b = SystemTime::now(); - match b.duration_since(a) { - Ok(dur) if dur == Duration::new(0, 0) => { - assert_almost_eq!(a, b); - } - Ok(dur) => { - assert!(b > a); - assert_almost_eq!(b - dur, a); - assert_almost_eq!(a + dur, b); - } - Err(dur) => { - let dur = dur.duration(); - assert!(a > b); - assert_almost_eq!(b + dur, a); - assert_almost_eq!(a - dur, b); - } - } - - let second = Duration::new(1, 0); - assert_almost_eq!(a.duration_since(a - second).unwrap(), second); - assert_almost_eq!(a.duration_since(a + second).unwrap_err().duration(), second); - - assert_almost_eq!(a - second + second, a); - assert_almost_eq!(a.checked_sub(second).unwrap().checked_add(second).unwrap(), a); - - let one_second_from_epoch = UNIX_EPOCH + Duration::new(1, 0); - let one_second_from_epoch2 = - UNIX_EPOCH + Duration::new(0, 500_000_000) + Duration::new(0, 500_000_000); - assert_eq!(one_second_from_epoch, one_second_from_epoch2); - - // checked_add_duration will not panic on overflow - let mut maybe_t = Some(SystemTime::UNIX_EPOCH); - let max_duration = Duration::from_secs(u64::MAX); - // in case `SystemTime` can store `>= UNIX_EPOCH + max_duration`. - for _ in 0..2 { - maybe_t = maybe_t.and_then(|t| t.checked_add(max_duration)); - } - assert_eq!(maybe_t, None); - - // checked_add_duration calculates the right time and will work for another year - let year = Duration::from_secs(60 * 60 * 24 * 365); - assert_eq!(a + year, a.checked_add(year).unwrap()); - } - - #[test] - fn system_time_elapsed() { - let a = SystemTime::now(); - drop(a.elapsed()); - } - - #[test] - fn since_epoch() { - let ts = SystemTime::now(); - let a = ts.duration_since(UNIX_EPOCH + Duration::new(1, 0)).unwrap(); - let b = ts.duration_since(UNIX_EPOCH).unwrap(); - assert!(b > a); - assert_eq!(b - a, Duration::new(1, 0)); - - let thirty_years = Duration::new(1, 0) * 60 * 60 * 24 * 365 * 30; - - // Right now for CI this test is run in an emulator, and apparently the - // aarch64 emulator's sense of time is that we're still living in the - // 70s. This is also true for riscv (also qemu) - // - // Otherwise let's assume that we're all running computers later than - // 2000. - if !cfg!(target_arch = "aarch64") && !cfg!(target_arch = "riscv64") { - assert!(a > thirty_years); - } - - // let's assume that we're all running computers earlier than 2090. - // Should give us ~70 years to fix this! - let hundred_twenty_years = thirty_years * 4; - assert!(a < hundred_twenty_years); - } -} |