Struct SubscriptionContext 

pub struct SubscriptionContext<T, E, OR, M, D: Disposable = ()> { /* private fields */ }

Context used by operator observers to serialize model updates and downstream events.

D is the disposal of the source subscription the context owns, and () when it owns none.

Implementations

impl<T, E, OR, M, D: Disposable> SubscriptionContext<T, E, OR, M, D>

pub fn downgrade(&self) -> WeakSubscriptionContext<T, E, OR, M, D>

Creates a non-owning reference to this context.

impl<T, E, OR, M, D> SubscriptionContext<T, E, OR, M, D>

where OR: Observer<T, E>, D: Disposable,

pub fn update<R, DO, const EVENTS_DECIDED: bool>( &self, callback: impl FnOnce(&mut M) -> UpdateOutcome<T, E, R, DO, EVENTS_DECIDED>, ) -> Result<R, DeliveryStopped>

Updates the model and sends the events that update produced, while the context is locked.

An update that emits nothing simply decides no events, and then nothing is sent here.

The callback must not call external APIs or drop values that can re-enter this context. Return such values through UpdateOutcome::with_drop_outside instead. If the context’s delivery has stopped, the callback is not invoked and DeliveryStopped is returned.

pub fn update_flow<DO, const EVENTS_DECIDED: bool>( &self, callback: impl FnOnce(&mut M) -> UpdateOutcome<T, E, (), DO, EVENTS_DECIDED>, ) -> Flow

Self::update for an operator’s on_next, reporting the flow instead of a result.

The flow is what delivering the events the update produced answered, and Flow::Stop when the context has stopped, so an operator observer can return it directly.

pub fn send_next(&self, value: T) -> Flow

Sends value downstream. Returns the flow of the delivery, as Self::send does.

pub fn send_termination(&self, termination: Termination<E>)

Sends termination downstream.

Nothing is answered: a termination is the last event, so the caller is done whether it was delivered, queued behind a running delivery, or rejected by a context that had already stopped — Self::send would say Flow::Stop in every case.

pub fn send(&self, events: EventBatch<T, E>) -> Flow

Sends events downstream, delivering them now or queueing them behind a running delivery.

Returns whether downstream still accepts events. Flow::Stop means the events were rejected and dropped, because the context has stopped or a termination is already queued, or that the stream is over: events carried a termination, or delivering them ended it.

Trait Implementations

impl<T, E, OR, M, D: Disposable> Clone for SubscriptionContext<T, E, OR, M, D>

where SerializedDelivery<T, E, OR, ContextResources<M, D>>: Clone,

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T, E, OR, M, D: Disposable> Debug for SubscriptionContext<T, E, OR, M, D>

where SerializedDelivery<T, E, OR, ContextResources<M, D>>: Debug,

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

Formats the value using the given formatter.