actix_rt::time

# Struct Instant

    pub struct Instant { /* private fields */ }

Expand description

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.

## §Note

This type wraps the inner `std` variant and is used to align the Tokio clock for uses of `now()`. This can be useful for testing where you can take advantage of `time::pause()` and `time::advance()`.

## Implementations§

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### impl Instant

#### pub fn now() -> Instant

Returns an instant corresponding to “now”.

##### §Examples

    use tokio::time::Instant;

    let now = Instant::now();

#### pub fn from_std(std: Instant) -> Instant

Create a `tokio::time::Instant` from a `std::time::Instant`.

#### pub fn into_std(self) -> Instant

Convert the value into a `std::time::Instant`.

#### pub fn duration_since(&self, earlier: Instant) -> Duration

Returns the amount of time elapsed from another instant to this one, or zero duration if that instant is later than this one.

#### pub fn checked_duration_since(&self, earlier: Instant) -> Option<Duration>

Returns the amount of time elapsed from another instant to this one, or None if that instant is later than this one.

##### §Examples

    use tokio::time::{Duration, Instant, sleep};

    #[tokio::main]
    async fn main() {
        let now = Instant::now();
        sleep(Duration::new(1, 0)).await;
        let new_now = Instant::now();
        println!("{:?}", new_now.checked_duration_since(now));
        println!("{:?}", now.checked_duration_since(new_now)); // None
    }

#### pub fn saturating_duration_since(&self, earlier: Instant) -> Duration

Returns the amount of time elapsed from another instant to this one, or zero duration if that instant is later than this one.

##### §Examples

    use tokio::time::{Duration, Instant, sleep};

    #[tokio::main]
    async fn main() {
        let now = Instant::now();
        sleep(Duration::new(1, 0)).await;
        let new_now = Instant::now();
        println!("{:?}", new_now.saturating_duration_since(now));
        println!("{:?}", now.saturating_duration_since(new_now)); // 0ns
    }

#### pub fn elapsed(&self) -> Duration

Returns the amount of time elapsed since this instant was created, or zero duration if that this instant is in the future.

##### §Examples

    use tokio::time::{Duration, Instant, sleep};

    #[tokio::main]
    async fn main() {
        let instant = Instant::now();
        let three_secs = Duration::from_secs(3);
        sleep(three_secs).await;
        assert!(instant.elapsed() >= three_secs);
    }

#### pub fn checked_add(&self, duration: Duration) -> Option<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.

#### pub fn checked_sub(&self, duration: Duration) -> Option<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.

## Trait Implementations§

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### impl Add<Duration> for Instant

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#### type Output = Instant

The resulting type after applying the `+` operator.
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#### fn add(self, other: Duration) -> Instant

Performs the `+` operation. Read more
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### impl AddAssign<Duration> for Instant

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#### fn add_assign(&mut self, rhs: Duration)

Performs the `+=` operation. Read more
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### impl Clone for Instant

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#### fn clone(&self) -> Instant

Returns a copy of the value. Read more
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#### fn clone_from(&mut self, source: &Self)

Performs copy-assignment from `source`. Read more
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### impl Debug for Instant

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#### fn fmt(&self, fmt: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter. Read more
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### impl From<Instant> for Instant

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#### fn from(time: Instant) -> Instant

Converts to this type from the input type.
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### impl Hash for Instant

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#### fn hash<__H>(&self, state: &mut __H)
where __H: Hasher,

Feeds this value into the given `Hasher`. Read more
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#### fn hash_slice<H>(data: &[Self], state: &mut H)
where H: Hasher, Self: Sized,

Feeds a slice of this type into the given `Hasher`. Read more
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### impl Ord for Instant

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#### fn cmp(&self, other: &Instant) -> Ordering

This method returns an `Ordering` between `self` and `other`. Read more
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#### fn max(self, other: Self) -> Self
where Self: Sized,

Compares and returns the maximum of two values. Read more
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#### fn min(self, other: Self) -> Self
where Self: Sized,

Compares and returns the minimum of two values. Read more
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#### fn clamp(self, min: Self, max: Self) -> Self
where Self: Sized,

Restrict a value to a certain interval. Read more
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### impl PartialEq for Instant

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#### fn eq(&self, other: &Instant) -> bool

Tests for `self` and `other` values to be equal, and is used by `==`.
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#### fn ne(&self, other: &Rhs) -> bool

Tests for `!=`. The default implementation is almost always sufficient, and should not be overridden without very good reason.
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### impl PartialOrd for Instant

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#### fn partial_cmp(&self, other: &Instant) -> Option<Ordering>

This method returns an ordering between `self` and `other` values if one exists. Read more
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#### fn lt(&self, other: &Rhs) -> bool

Tests less than (for `self` and `other`) and is used by the `<` operator. Read more
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#### fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for `self` and `other`) and is used by the `<=` operator. Read more
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#### fn gt(&self, other: &Rhs) -> bool

Tests greater than (for `self` and `other`) and is used by the `>` operator. Read more
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#### fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for `self` and `other`) and is used by the `>=` operator. Read more
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### impl Sub<Duration> for Instant

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#### type Output = Instant

The resulting type after applying the `-` operator.
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#### fn sub(self, rhs: Duration) -> Instant

Performs the `-` operation. Read more
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### impl Sub for Instant

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#### type Output = Duration

The resulting type after applying the `-` operator.
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#### fn sub(self, rhs: Instant) -> Duration

Performs the `-` operation. Read more
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### impl SubAssign<Duration> for Instant

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#### fn sub_assign(&mut self, rhs: Duration)

Performs the `-=` operation. Read more
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### impl Copy for Instant

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### impl Eq for Instant

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### impl StructuralPartialEq for Instant

## Auto Trait Implementations§

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### impl Freeze for Instant

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### impl RefUnwindSafe for Instant

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### impl Send for Instant

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### impl Sync for Instant

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### impl Unpin for Instant

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### impl UnwindSafe for Instant

## Blanket Implementations§

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### impl<T> Any for T
where T: 'static + ?Sized,

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#### fn type_id(&self) -> TypeId

Gets the `TypeId` of `self`. Read more
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### impl<T> Borrow<T> for T
where T: ?Sized,

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#### fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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### impl<T> BorrowMut<T> for T
where T: ?Sized,

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#### fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
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### impl<T> CloneToUninit for T
where T: Clone,

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#### unsafe fn clone_to_uninit(&self, dst: *mut T)

🔬This is a nightly-only experimental API. (`clone_to_uninit`)
Performs copy-assignment from `self` to `dst`. Read more
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### impl<T> From<T> for T

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#### fn from(t: T) -> T

Returns the argument unchanged.

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### impl<T, U> Into<U> for T
where U: From<T>,

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#### fn into(self) -> U

Calls `U::from(self)`.

That is, this conversion is whatever the implementation of `From<T> for U` chooses to do.

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### impl<T> ToOwned for T
where T: Clone,

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#### type Owned = T

The resulting type after obtaining ownership.
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#### fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more
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#### fn clone_into(&self, target: &mut T)

Uses borrowed data to replace owned data, usually by cloning. Read more
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### impl<T, U> TryFrom<U> for T
where U: Into<T>,

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#### type Error = Infallible

The type returned in the event of a conversion error.
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#### fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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### impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

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#### type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
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#### fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.