Struct PubSubBroker 

pub struct PubSubBroker { /* private fields */ }

In-memory pub/sub broker with channel-based messaging, history retention, and glob-pattern subscriptions.

Implementations

impl PubSubBroker

pub fn new(max_history_per_channel: usize) -> Self

Create a new broker that retains up to max_history_per_channel messages per channel.

pub fn publish(&self, channel: &str, message: &str) -> usize

Publish a message to a channel. Returns the number of subscribers that were notified.

pub fn subscribe( &self, channel: &str, callback: Box<dyn Fn(&PubSubMessage) + Send + Sync>, ) -> u64

Subscribe to a channel. Returns a subscription ID that can be used to unsubscribe later.

pub fn unsubscribe(&self, channel: &str, sub_id: u64) -> bool

Unsubscribe from a channel by subscription ID. Returns true if the subscription was found and removed.

pub fn history(&self, channel: &str, limit: usize) -> Vec<PubSubMessage>

Get recent message history for a channel, up to limit messages. Returns messages in chronological order (oldest first).

pub fn channels(&self) -> Vec<(String, usize)>

List all channels that have at least one subscriber, along with their subscriber counts.

pub fn subscriber_count(&self, channel: &str) -> usize

Get the number of subscribers for a specific channel.

pub fn psubscribe( &self, pattern: &str, callback: Box<dyn Fn(&PubSubMessage) + Send + Sync>, ) -> Vec<u64>

Pattern-subscribe: subscribe to all existing channels whose names match a glob pattern. Returns the subscription IDs created (one per matched channel).

Note: this is a snapshot-based pattern subscribe. Channels created after the call will not be matched automatically.

pub fn channels_with_history(&self) -> Vec<String>

List all channels that have history entries (regardless of whether they have active subscribers).