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Clock

win_time_sys

Trait Clock 

Source 
pub trait Clock {
    type Timeline: Timeline;

    // Required method
    fn now(&self) -> TimePoint<Self::Timeline>;
}
Expand description

A way to read “now” on one timeline. Several clocks may share a timeline, differing only in what a reading costs and how fresh it is; their readings compare with each other because they are points on the same timeline.

now takes &self (WT-D-7), so a clock may carry state – a test’s fake clock, or a value it reads once and keeps – and code that is generic over a clock is handed one.

use core::cell::Cell;
use core::num::NonZeroU64;
use win_time_sys::{Clock, TimePoint, Ticks, Timeline};

/// Ticks of one millisecond since some zero.
enum Millis {}
impl Timeline for Millis {
    fn ticks_per_second() -> NonZeroU64 { NonZeroU64::new(1_000).unwrap() }
}

/// A fake clock a test advances by hand.
struct Manual(Cell<u64>);
impl Clock for Manual {
    type Timeline = Millis;
    fn now(&self) -> TimePoint<Millis> { TimePoint::from_ticks(self.0.get()) }
}

fn elapsed<C: Clock>(clock: &C, since: TimePoint<C::Timeline>) -> Ticks<C::Timeline> {
    clock.now() - since
}

let clock = Manual(Cell::new(1_000));
let start = clock.now();
clock.0.set(1_250);
assert_eq!(elapsed(&clock, start).to_duration(), Some(core::time::Duration::from_millis(250)));

Required Associated Types§

Source

type Timeline: Timeline

The timeline this clock reads.

Required Methods§

Source

fn now(&self) -> TimePoint<Self::Timeline>

The current point on the timeline.

Dyn Compatibility§

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors§