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Transport

pamoja_core::transport

Trait Transport 

Source 
pub trait Transport {
    // Required methods
    fn connect(&mut self) -> impl Future<Output = Result<()>> + Send;
    fn send(
        &mut self,
        topic: &str,
        payload: &[u8],
    ) -> impl Future<Output = Result<()>> + Send;
    fn subscribe(
        &mut self,
        topic: &str,
    ) -> impl Future<Output = Result<()>> + Send;

    // Provided method
    fn send_text(
        &mut self,
        topic: &str,
        text: &str,
    ) -> impl Future<Output = Result<()>> + Send { ... }
}
Expand description

A bidirectional, topic-addressed message transport.

Implementations include MQTT, CoAP, LoRa, serial, and CAN. They are expected to handle reconnection and backpressure internally so that callers see a uniform, protocol-agnostic surface.

This trait is the outbound half of a link: connect, publish, and register interest in a topic. A link that can also deliver what it subscribed to implements Receive as well. The two are separate because not every link listens: a LoRa uplink or a satellite messenger only sends, and it still belongs on a transport ladder.

The returned futures are Send, so a transport can be driven from a task on a multi-threaded runtime and can be erased behind a trait object that is. Both matter in practice: a gateway ticks its links from spawned tasks, and a transport ladder holds rungs of different concrete types in one list. An implementation written as async fn satisfies this as long as everything it holds across an await is Send, which every transport here already is.

Required Methods§

Source

fn connect(&mut self) -> impl Future<Output = Result<()>> + Send

Establishes the connection to the broker, peer, or bus.

§Returns

Ok(()) once the transport is connected and ready to carry traffic.

§Errors

Returns Error::Transport if the connection cannot be established.

Source

fn send( &mut self, topic: &str, payload: &[u8], ) -> impl Future<Output = Result<()>> + Send

Publishes a payload to a topic.

§Arguments
  • topic - the destination topic or channel address.
  • payload - the raw bytes to publish.
§Returns

Ok(()) once the payload has been handed to the transport for delivery.

§Errors

Returns Error::Transport if the payload cannot be sent, or Error::Closed if the transport is not connected.

Source

fn subscribe(&mut self, topic: &str) -> impl Future<Output = Result<()>> + Send

Subscribes to a topic so that matching payloads are routed to this transport.

§Arguments
  • topic - the topic or channel filter to subscribe to.
§Returns

Ok(()) once the subscription is registered with the transport.

§Errors

Returns Error::Transport if the subscription is rejected, or Error::Closed if the transport is not connected.

Provided Methods§

Source

fn send_text( &mut self, topic: &str, text: &str, ) -> impl Future<Output = Result<()>> + Send

Publishes text to a topic: words, or a number written out.

This is send with the text’s UTF-8 bytes, so a reading or a command that is plain text needs no encoding step on either end; the receiver reads it back with Message::text or Message::number.

§Arguments
  • topic - the destination topic.
  • text - the text to publish.
§Returns

Ok(()) once the transport has accepted the message.

§Errors

Whatever send returns.

Dyn Compatibility§

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors§