Crate pubsub_rs

A publish-subscribe system for Rust with async/await support.

This crate provides a simple yet powerful publish-subscribe (pubsub) system that allows multiple subscribers to receive messages published to specific topics. It’s designed to be:

• Thread-safe: Uses Arc and DashMap for concurrent access
• Async-friendly: Built with async/await support using async-channel
• Memory efficient: Uses weak references to prevent memory leaks
• Clean shutdown: Automatically cleans up resources when dropped

Features

• Multiple subscribers per topic
• Multiple topics per subscriber
• Thread-safe operations
• Async message delivery
• Automatic cleanup of dropped subscribers
• Graceful shutdown handling

Basic Usage

use pubsub_rs::{Pubsub, PubsubError};

#[tokio::main]
async fn main() {
    let pubsub = Pubsub::new();

    // Subscribe to topics
    let subscriber = pubsub.subscribe(vec!["topic1", "topic2"]).await;

    // Publish messages
    pubsub.publish("topic1", "Hello".to_owned()).await;

    // Receive messages
    let (topic, message) = subscriber.recv().await.unwrap();
    assert_eq!(topic, "topic1");
    assert_eq!(message, "Hello");
}

Error Handling

The main error type is PubsubError, which occurs when:

• The pubsub system has been closed
• A subscriber tries to receive messages after the pubsub system is dropped

Performance Considerations

• Uses DashMap for concurrent topic storage
• Each subscriber has its own async channel
• Message delivery is non-blocking
• Automatic cleanup of dropped subscribers

Safety

• All operations are thread-safe
• Uses Arc for shared ownership
• Uses Weak references to prevent memory leaks
• Proper cleanup on drop

Examples

See the tests module for more comprehensive usage examples.

Structs

Pubsub

A publish-subscribe system that allows multiple subscribers to receive messages published to specific topics.

PubsubError

Error type returned when a Pubsub operation fails.

Subscriber

A subscriber that receives messages for subscribed topics from a Pubsub system.

Traits

PubsubTopic

A trait that defines the requirements for types that can be used as Pubsub topics.