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Monorepo for Tangled tangled.org
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2.3 kB · 84 lines
Rust
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pub use knot_types::UnixMicros;
pub trait Clock: Send + Sync + 'static { fn now_unix_micros(&self) -> UnixMicros;}
impl<T: Clock + ?Sized> Clock for Arc<T> { fn now_unix_micros(&self) -> UnixMicros { (**self).now_unix_micros() }}
pub struct SystemClock;
impl Clock for SystemClock { fn now_unix_micros(&self) -> UnixMicros { let micros = SystemTime::now() .duration_since(UNIX_EPOCH) .map(|elapsed| elapsed.as_micros() as u64) .unwrap_or(0); UnixMicros::new(micros) }}
pub struct ManualClock { micros: AtomicU64,}
impl ManualClock { pub fn new(start: UnixMicros) -> Self { Self { micros: AtomicU64::new(start.get()), } }
pub fn advance(&self, delta: Duration) { self.micros .fetch_add(delta.as_micros() as u64, Ordering::SeqCst); }}
impl Clock for ManualClock { fn now_unix_micros(&self) -> UnixMicros { UnixMicros::new(self.micros.load(Ordering::SeqCst)) }}
#[cfg(test)]mod tests { use super::*;
#[test] fn manual_clock_advances() { let clock = ManualClock::new(UnixMicros::new(1_000)); assert_eq!(clock.now_unix_micros().get(), 1_000); clock.advance(Duration::from_micros(500)); assert_eq!(clock.now_unix_micros().get(), 1_500); }
#[test] fn manual_clock_same_start_same_sequence() { let one = ManualClock::new(UnixMicros::new(1_000)); let two = ManualClock::new(UnixMicros::new(1_000)); let advances = [10, 250, 7, 1_000]; advances.iter().for_each(|&step| { one.advance(Duration::from_micros(step)); two.advance(Duration::from_micros(step)); assert_eq!(one.now_unix_micros(), two.now_unix_micros()); }); }
#[test] fn a_shared_clock_advances_through_the_trait_object() { let shared = Arc::new(ManualClock::new(UnixMicros::new(1_000))); let view: Arc<dyn Clock> = Arc::clone(&shared) as Arc<dyn Clock>; assert_eq!(view.now_unix_micros().get(), 1_000); shared.advance(Duration::from_micros(250)); assert_eq!(view.now_unix_micros().get(), 1_250); }}