Struct Topic 

pub struct Topic { /* private fields */ }

Handle to a joined gossip topic with auto-discovery.

Manages bootstrap, publishing, bubble detection, and split-brain recovery. Can be split into sender and receiver for message exchange.

Implementations

impl Topic

pub async fn new( record_publisher: RecordPublisher, gossip: Gossip, async_bootstrap: bool, ) -> Result<Self>

Create and initialize a new topic with auto-discovery.

Arguments

• record_publisher - Record publisher for DHT operations
• gossip - Gossip instance for topic subscription
• async_bootstrap - If false, awaits until bootstrap completes

pub async fn split(&self) -> Result<(GossipSender, GossipReceiver)>

Split into sender and receiver for message exchange.

Examples found in repository

examples/simple.rs (line 49)

async fn main() -> Result<()> {
    // Generate a new random secret key
    let secret_key = SecretKey::generate(&mut rand::rng());

    // Set up endpoint with discovery enabled
    let endpoint = Endpoint::builder()
        .secret_key(secret_key.clone())
        .discovery_n0()
        .bind()
        .await?;

    // Initialize gossip with auto-discovery
    let gossip = Gossip::builder().spawn(endpoint.clone());

    // Set up protocol router
    let _router = iroh::protocol::Router::builder(endpoint.clone())
        .accept(iroh_gossip::ALPN, gossip.clone())
        .spawn();

    let topic_id = TopicId::new("my-iroh-gossip-topic".to_string());
    let initial_secret = b"my-initial-secret".to_vec();

    // Split into sink (sending) and stream (receiving)

    let record_publisher = RecordPublisher::new(
        topic_id.clone(),
        endpoint.node_id().public(),
        secret_key.secret().clone(),
        None,
        initial_secret,
    );

    let topic = gossip
        .subscribe_and_join_with_auto_discovery(record_publisher)
        .await?;

    println!("[joined topic]");

    // Do something with the gossip topic
    // (bonus: GossipSender and GossipReceiver are safely clonable)
    let (_gossip_sender, _gossip_receiver) = topic.split().await?;

    Ok(())
}

examples/e2e_test.rs (line 41)

async fn main() -> Result<()> {
    // Generate a new random secret key
    let secret_key = SecretKey::generate(&mut rand::rng());

    // Set up endpoint with discovery enabled
    let endpoint = Endpoint::builder()
        .secret_key(secret_key.clone())
        .discovery_n0()
        .bind()
        .await?;

    // Initialize gossip with auto-discovery
    let gossip = Gossip::builder().spawn(endpoint.clone());

    // Set up protocol router
    let _router = iroh::protocol::Router::builder(endpoint.clone())
        .accept(iroh_gossip::ALPN, gossip.clone())
        .spawn();

    let topic_id = TopicId::new("my-iroh-gossip-topic".to_string());
    let initial_secret = b"my-initial-secret".to_vec();

    let record_publisher = RecordPublisher::new(
        topic_id.clone(),
        endpoint.node_id().public(),
        secret_key.secret().clone(),
        None,
        initial_secret,
    );
    let (gossip_sender, gossip_receiver) = gossip
        .subscribe_and_join_with_auto_discovery(record_publisher)
        .await?
        .split()
        .await?;

    tokio::spawn(async move {
        while let Some(Ok(event)) = gossip_receiver.next().await {
            println!("event: {event:?}");
        }
    });

    tokio::time::sleep(std::time::Duration::from_secs(3)).await;
    gossip_sender
        .broadcast(format!("hi from {}", endpoint.node_id()).into())
        .await?;

    println!("[joined topic]");

    tokio::time::sleep(std::time::Duration::from_secs(10)).await;

    println!("[finished]");

    // successfully joined
    // exit with code 0
    Ok(())
}

examples/chat_no_wait.rs (line 41)

async fn main() -> Result<()> {
    // Generate a new random secret key
    let secret_key = SecretKey::generate(&mut rand::rng());

    // Set up endpoint with discovery enabled
    let endpoint = Endpoint::builder()
        .secret_key(secret_key.clone())
        .discovery_n0()
        .bind()
        .await?;

    // Initialize gossip with auto-discovery
    let gossip = Gossip::builder().spawn(endpoint.clone());

    // Set up protocol router
    let _router = iroh::protocol::Router::builder(endpoint.clone())
        .accept(iroh_gossip::ALPN, gossip.clone())
        .spawn();

    let topic_id = TopicId::new("my-iroh-gossip-topic".to_string());
    let initial_secret = b"my-initial-secret".to_vec();

    let record_publisher = RecordPublisher::new(
        topic_id.clone(),
        endpoint.node_id().public(),
        secret_key.secret().clone(),
        None,
        initial_secret,
    );
    let (gossip_sender, gossip_receiver) = gossip
        .subscribe_and_join_with_auto_discovery_no_wait(record_publisher)
        .await?
        .split()
        .await?;

    println!("Joined topic");

    // Spawn listener for incoming messages
    tokio::spawn(async move {
        while let Some(Ok(event)) = gossip_receiver.next().await {
            if let Event::Received(msg) = event {
                println!(
                    "\nMessage from {}: {}",
                    &msg.delivered_from.to_string()[0..8],
                    String::from_utf8(msg.content.to_vec()).unwrap()
                );
            } else if let Event::NeighborUp(peer) = event {
                println!("\nJoined by {}", &peer.to_string()[0..8]);
            }
        }
    });

    // Main input loop for sending messages
    let mut buffer = String::new();
    let stdin = std::io::stdin();
    loop {
        print!("\n> ");
        stdin.read_line(&mut buffer).unwrap();
        gossip_sender
            .broadcast(buffer.clone().replace("\n", "").into())
            .await
            .unwrap();
        println!(" - (sent)");
        buffer.clear();
    }
}

examples/secret_rotation.rs (line 63)

async fn main() -> Result<()> {
    // Generate a new random secret key
    let secret_key = SecretKey::generate(&mut rand::rng());

    // Set up endpoint with discovery enabled
    let endpoint = Endpoint::builder()
        .secret_key(secret_key.clone())
        .discovery_n0()
        .bind()
        .await?;

    // Initialize gossip with auto-discovery
    let gossip = Gossip::builder().spawn(endpoint.clone());

    // Set up protocol router
    let _router = iroh::protocol::Router::builder(endpoint.clone())
        .accept(iroh_gossip::ALPN, gossip.clone())
        .spawn();

    let topic_id = TopicId::new("my-iroh-gossip-topic".to_string());
    let initial_secret = b"my-initial-secret".to_vec();

    // Split into sink (sending) and stream (receiving)

    let record_publisher = RecordPublisher::new(
        topic_id.clone(),
        endpoint.node_id().public(),
        secret_key.secret().clone(),
        Some(RotationHandle::new(MySecretRotation)),
        initial_secret,
    );
    let (gossip_sender, gossip_receiver) = gossip
        .subscribe_and_join_with_auto_discovery(record_publisher)
        .await?
        .split()
        .await?;

    println!("Joined topic");

    // Spawn listener for incoming messages
    tokio::spawn(async move {
        while let Some(Ok(event)) = gossip_receiver.next().await {
            if let Event::Received(msg) = event {
                println!(
                    "\nMessage from {}: {}",
                    &msg.delivered_from.to_string()[0..8],
                    String::from_utf8(msg.content.to_vec()).unwrap()
                );
            } else if let Event::NeighborUp(peer) = event {
                println!("\nJoined by {}", &peer.to_string()[0..8]);
            }
        }
    });

    // Main input loop for sending messages
    let mut buffer = String::new();
    let stdin = std::io::stdin();
    loop {
        print!("\n> ");
        stdin.read_line(&mut buffer).unwrap();
        gossip_sender
            .broadcast(buffer.clone().replace("\n", "").into())
            .await
            .unwrap();
        println!(" - (sent)");
        buffer.clear();
    }
}

examples/chat.rs (line 56)

async fn main() -> Result<()> {

    // tracing init - only show distributed_topic_tracker logs
    use tracing_subscriber::filter::EnvFilter;
    
    tracing_subscriber::fmt()
        .with_thread_ids(true)
        .with_ansi(true)
        .with_env_filter(
            EnvFilter::try_from_default_env()
                .unwrap_or_else(|_| EnvFilter::new("distributed_topic_tracker=debug"))
        )
        .init();

    // Generate a new random secret key
    let secret_key = SecretKey::generate(&mut rand::rng());

    // Set up endpoint with discovery enabled
    let endpoint = Endpoint::builder()
        .secret_key(secret_key.clone())
        .discovery_n0()
        .bind()
        .await?;

    // Initialize gossip with auto-discovery
    let gossip = Gossip::builder().spawn(endpoint.clone());

    // Set up protocol router
    let _router = iroh::protocol::Router::builder(endpoint.clone())
        .accept(iroh_gossip::ALPN, gossip.clone())
        .spawn();

    let topic_id = TopicId::new("my-iroh-gossip-topic".to_string());
    let initial_secret = b"my-initial-secret".to_vec();

    let record_publisher = RecordPublisher::new(
        topic_id.clone(),
        endpoint.node_id().public(),
        secret_key.secret().clone(),
        None,
        initial_secret,
    );

    // Split into sink (sending) and stream (receiving)
    let (gossip_sender, gossip_receiver) = gossip
        .subscribe_and_join_with_auto_discovery(record_publisher)
        .await?
        .split()
        .await?;

    println!("Joined topic");

    // Spawn listener for incoming messages
    tokio::spawn(async move {
        while let Some(Ok(event)) = gossip_receiver.next().await {
            if let Event::Received(msg) = event {
                println!(
                    "\nMessage from {}: {}",
                    &msg.delivered_from.to_string()[0..8],
                    String::from_utf8(msg.content.to_vec()).unwrap()
                );
            } else if let Event::NeighborUp(peer) = event {
                println!("\nJoined by {}", &peer.to_string()[0..8]);
            }
        }
    });

    // Main input loop for sending messages
    let mut buffer = String::new();
    let stdin = std::io::stdin();
    loop {
        print!("\n> ");
        stdin.read_line(&mut buffer).unwrap();
        gossip_sender
            .broadcast(buffer.clone().replace("\n", "").into())
            .await
            .unwrap();
        println!(" - (sent)");
        buffer.clear();
    }
}

pub async fn gossip_sender(&self) -> Result<GossipSender>

Get the gossip sender for this topic.

pub async fn gossip_receiver(&self) -> Result<GossipReceiver>

Get the gossip receiver for this topic.

pub async fn record_creator(&self) -> Result<RecordPublisher>

Get the record publisher for this topic.

Trait Implementations

impl Clone for Topic

fn clone(&self) -> Topic

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Topic

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

Formats the value using the given formatter.