Struct Stamped 

pub struct Stamped<T> { /* private fields */ }

A signal wrapper that stamps every write with the time it happened, so a reader can ask how old the value is.

The read-side half of write freshness. The monitor side already exists: writes: [X observed beat] with a beat_timeout: reports a node that has not written recently. Stamped gives the consumer the same fact at the point of use — age, is_fresh, read_fresh — for the case the monitor cannot cover: a value that is still being written but must not be trusted past a certain age. What neither can tell is whether a fresh value is valid; a plausible-looking drift needs a consumer that understands the value.

Writes go through w, reads through r; there is deliberately no Deref, so an unstamped write path does not exist. It records the time and nothing else — compose Stamped<Counted<T>> when the write count matters too. Costs one AtomicU32 and one AtomicBool beside the wrapped value. The stamp is Instant ticks truncated to u32, like the node heartbeat: ages are exact up to u32::MAX ticks.

Implementations

impl<T> Stamped<T>

pub const fn new(inner: T) -> Self

Wrap inner, never written.

pub fn w(&self) -> &T

Borrow the inner signal for a write, stamping now.

pub fn r(&self) -> &T

Borrow the inner signal for a read.

pub fn inner(&self) -> &T

Borrow the inner signal without touching the stamp.

pub fn age(&self) -> Option<Duration>

Time since the last stamped write, None until the first.

pub fn is_fresh(&self, max_age: Duration) -> bool

Has the signal been written within max_age?

pub fn read_fresh(&self, max_age: Duration) -> Option<&T>

The inner signal if it was written within max_age, else None.

Trait Implementations

impl<T: Observable> Observable for Stamped<T>

Available on crate feature coupling-observe only.

fn change_token(&self) -> u32

Return a token that changes when the signal is written.

impl<T: Sink> Sink for Stamped<T>

Available on crate feature dataflow only.

type Item = <T as Sink>::Item

The value type written into the signal.

fn put(&self, v: T::Item)

Write v into the signal.

impl<T: Source> Source for Stamped<T>

Available on crate feature dataflow only.

type Item = <T as Source>::Item

The value type read from the signal.

fn get(&self) -> T::Item

Return a snapshot of the signal’s current value.