Struct Eventual

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

The entry point for getting the latest snapshots of values written by an EventualWriter. It supports multiple styles of observation.

Implementations

impl<T> Eventual<T>

where T: Value,

pub fn new() -> (EventualWriter<T>, Self)

Create a reader/writer pair.

pub fn from_value(value: T) -> Self

Create an eventual having a final value. This is useful for creating “mock” eventuals to pass into consumers.

pub fn spawn<F, Fut>(f: F) -> Self

where F: "static + Send + FnOnce(EventualWriter<T>) -> Fut, Fut: Future<Output = Result<Never, Closed>> + Send,

A helper for spawning a task which writes to an eventual. These are used extensively within the library for eventuals which update continuously over time.

pub fn subscribe(&self) -> EventualReader<T>

Subscribe to present and future snapshots of the value in this Eventual. Generally speaking the observations of snapshots take into account the state of the reader such that:

• The same observation is not made redundantly (same value twice in a row)
• The observations always move forward in time
• The final observation will always be eventually consistent with the final write.

pub fn value(&self) -> ValueFuture<T>

Get a future that resolves with a snapshot of the present value of the Eventual, if any, or a future snapshot if none is available. Which snapshot is returned depends on when the Future is polled (as opposed to when the Future is created)

pub fn value_immediate(&self) -> Option<T>

Get a snapshot of the current value of this Eventual, if any, without waiting.

Trait Implementations

impl<T> Clone for Eventual<T>

fn clone(&self) -> Self

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<T> IntoReader for &Eventual<T>

where T: Value,

type Output = T

fn into_reader(self) -> EventualReader<Self::Output>

impl<T> IntoReader for Eventual<T>

where T: Value,

type Output = T

fn into_reader(self) -> EventualReader<Self::Output>