Struct Snapshot 

pub struct Snapshot<T> {
    slot: Arc<SnapshotSlot<T>>,
}

The producing end of a Snapshot: keeps the newest value for however many readers are subscribed.

Cloning shares the slot. It keeps the newest value whether or not anyone is subscribed, so a reader that arrives after a publish still finds it instead of waiting for the next one.

Fields

slot: Arc<SnapshotSlot<T>>

Implementations

impl<T> Snapshot<T>

pub fn new() -> Snapshot<T>

A slot nobody is subscribed to yet.

pub fn publish(&self, value: T) -> usize

Replace the value, and answer how many readers are subscribed.

The value is kept even with none subscribed, so one that subscribes later still finds the newest publish. A collector uses the answer to prune its own subscription: at zero, nobody is left to read it.

pub fn reader(&self) -> SnapshotReader<T>

A reader of this slot. The snapshot stays a slot as long as any reader or the producing handle is alive.

pub fn has_readers(&self) -> bool

Whether a reader is subscribed.

Trait Implementations

impl<T> Clone for Snapshot<T>

fn clone(&self) -> Snapshot<T>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T> Debug for Snapshot<T>

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

Formats the value using the given formatter.

impl<T> Default for Snapshot<T>

fn default() -> Snapshot<T>

Returns the “default value” for a type.