Struct Topic 

pub struct Topic<T: Send + Sync + 'static> { /* private fields */ }

A cloneable stream-native broadcast topic.

Clone the handle for publishers. Each call to Topic::subscribe returns a source blueprint; each materialization registers a fresh subscriber slot. Subscribers observe every element published after their registration, in the same global order as every other subscriber, subject to this topic’s overflow policy.

Capacity is per subscriber and must be greater than zero.

Implementations

impl<T: Send + Sync + 'static> Topic<T>

pub fn new(capacity: usize, overflow: TopicOverflow) -> StreamResult<Self>

Create a new topic with per-subscriber capacity and overflow policy.

Panics if capacity == 0.

pub async fn publish(&self, value: T) -> Result<(), TopicPublishError<T>>

Publish one value, waiting only under TopicOverflow::Backpressure.

The publish linearizes when this call owns its global sequence turn and loads the subscriber-table snapshot. Subscribers in that snapshot receive the value according to the configured overflow policy; subscribers registered later do not. If the topic has no subscribers, the value is accepted and dropped.

pub fn try_publish(&self, value: T) -> Result<(), TopicTryPublishError<T>>

Try to publish one value without awaiting subscriber capacity or an earlier in-flight publisher.

Under TopicOverflow::Backpressure, this returns TopicTryPublishError::Full if any active subscriber in the publish snapshot is full. Under all policies, it returns TopicTryPublishError::Busy if another publisher currently owns an earlier global publish turn.

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

where T: Clone,

Return a source blueprint that registers a fresh subscriber when materialized.

The source emits only elements published after its registration. If the topic is already closed, the materialized source completes immediately.

pub fn subscriber_count(&self) -> usize

Return the number of currently active subscribers.

pub fn close(&self) -> StreamResult<()>

Gracefully close the topic.

Current subscribers drain their queued elements before completing. Publishers that begin after close fail with TopicPublishError::Closed or TopicTryPublishError::Closed.

pub fn is_closed(&self) -> bool

Return true after the topic has closed.

pub async fn closed(&self)

Wait until the topic is closed.

Trait Implementations

impl<T: Send + Sync + 'static> Clone for Topic<T>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T: Send + Sync + 'static> Debug for Topic<T>

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

Formats the value using the given formatter.