Struct TopicRouter 

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

Routes MQTT topics to subscription payloads.

Each subscription pattern is associated with a payload T and a unique SubscriptionId. Delivered topics are matched against all stored patterns (including +/# wildcards); the router also bookkeeps which distinct broker subscriptions are active and at what QoS.

Implementations

impl<T> TopicRouter<T>

pub fn new() -> Self

Creates an empty router with no subscriptions.

pub fn add_subscription( &mut self, topic: TopicPatternPath, qos: impl Into<QoS>, subscription: T, ) -> (bool, SubscriptionId)

Registers a subscription for topic with the given qos and payload.

Returns (needs_subscribe, id): needs_subscribe is true when this is the first subscription for the pattern or it raises the effective QoS, so the caller must (re)subscribe on the broker; id identifies the new subscription for later unsubscribe.

pub fn unsubscribe( &mut self, id: &SubscriptionId, ) -> Result<(bool, TopicPatternPath), TopicRouterError>

Removes the subscription identified by id.

Returns (topic_now_empty, pattern): topic_now_empty is true when no other subscription remains for the pattern, so the caller should unsubscribe it on the broker. Fails with TopicRouterError::SubscriptionNotFound if id is unknown.

pub fn get_subscribers<'a>( &'a self, topic: &TopicPath, ) -> Vec<(&'a SubscriptionId, &'a (TopicPatternPath, QoS), &'a T)>

Returns every subscription whose pattern matches topic.

Each entry is (id, (pattern, qos), payload) for a matching subscription (one delivered topic may match several patterns via +/# wildcards).

pub fn get_active_subscriptions( &self, ) -> impl Iterator<Item = &(TopicPatternPath, QoS)>

Iterates over every active subscription as (pattern, qos).

Patterns are not deduplicated; multiple subscriptions may share one.

pub fn get_topics_for_unsubscribe(&self) -> HashSet<ArcStr>

Get all unique active topic patterns

pub fn get_topics_for_resubscribe(&self) -> HashMap<ArcStr, QoS>

Get all active topic patterns with their maximum QoS Returns unique topics (grouped by pattern) with the highest QoS among all subscribers

pub fn cleanup(&mut self)

Cleanup all internal data structures and close subscriber channels This method is called during shutdown to ensure proper resource cleanup

pub fn get_topic_by_id( &self, id: &SubscriptionId, ) -> Result<&(TopicPatternPath, QoS), TopicRouterError>

Looks up the (pattern, qos) registered for a subscription id.

Fails with TopicRouterError::SubscriptionNotFound if id is unknown.

Trait Implementations

impl<T> Default for TopicRouter<T>

fn default() -> Self

Returns the “default value” for a type.