Struct MqttierClient 

pub struct MqttierClient {
    pub client_id: String,
    pub online_topic: String,
    /* private fields */
}

MqttierClient provides an abstracted, Clone-able interface around rumqttc.

Usage contract:

• Construct with MqttierClient::new(...).
• Call run_loop().await once per client to start background tasks.
• Use subscribe(...) to register a subscription and a channel sender for messages.
• Use publish* helpers to publish data; they return a oneshot receiver that will be resolved when the publish completes (or timed out / error).

Fields

client_id: String

online_topic: String

Implementations

impl MqttierClient

pub fn new(mqttier_options: MqttierOptions) -> Result<Self, MqttierError>

Create a new MqttierClient.

Arguments

• hostname - The hostname of the MQTT broker
• port - The port of the MQTT broker
• client_id - Optional client ID. If None, a random UUID will be generated

pub async fn subscribe( &self, topic: String, qos: u8, received_message_tx: Sender<ReceivedMessage>, ) -> Result<usize, MqttierError>

Subscribe to a topic.

Arguments

Arguments:

• topic: topic to subscribe to
• qos: QoS level (0, 1, 2)
• received_message_tx: mpsc Sender that will receive ReceivedMessages for this subscription

Returns: subscription id (usize) on success.

pub async fn publish( &self, topic: String, payload: Vec<u8>, qos: QoS, retain: bool, publish_props: Option<PublishProperties>, ) -> Receiver<PublishResult>

Publish a raw payload to a topic.

Arguments

• topic - The topic to publish to

Arguments:

• topic: topic to publish to
• payload: raw payload bytes
• qos: QoS (use rumqttc::v5::mqttbytes::QoS variants)
• retain: whether to set the retain flag
• publish_props: optional MQTT5 publish properties

Returns: a oneshot::Receiver<PublishResult> that will resolve when the publish completes or errors.

pub async fn publish_string( &self, topic: String, payload: String, qos: u8, retain: bool, publish_props: Option<PublishProperties>, ) -> Receiver<PublishResult>

Publish a UTF-8 string payload to a topic.

Arguments

• topic - The topic to publish to
• payload - The string payload to send
• qos - The QoS level for the message (0, 1, or 2)
• retain - Whether to retain the message
• publish_props - Optional publish properties

Returns

Returns a receiver that will be notified when the message is acknowledged by the broker

pub async fn publish_structure<T: Serialize>( &self, topic: String, payload: T, ) -> Receiver<PublishResult>

Publish a serializable struct as JSON to a topic (QoS 2 by default in helper).

Arguments

• topic - The topic to publish to
• payload - The serializable struct to send as payload
• state_version - The version of the structure

Returns

Returns a receiver that will be notified when the message is acknowledged by the broker

pub async fn publish_request<T: Serialize>( &self, topic: String, payload: T, response_topic: String, correlation_id: Vec<u8>, ) -> Receiver<PublishResult>

Publish a request message to a topic with response topic and correlation id.

Arguments

• topic - The topic to publish to
• payload - The serializable struct to send as payload
• response_topic - The topic where responses should be sent
• correlation_id - The correlation id for matching responses

Returns

Returns a receiver that will be notified when the message is acknowledged by the broker

pub async fn publish_response<T: Serialize>( &self, topic: String, payload: T, correlation_id: Vec<u8>, ) -> Receiver<PublishResult>

Publish a response message to a topic with correlation id.

Arguments

• topic - The topic to publish to
• payload - The serializable struct to send as payload
• correlation_id - The correlation id for matching requests

Returns

Returns a receiver that will be notified when the message is acknowledged by the broker

pub async fn publish_error_response( &self, topic: String, error_message: String, correlation_id: Vec<u8>, return_code: u32, ) -> Receiver<PublishResult>

Publish an error response message to a topic with correlation id.

This sends an empty JSON object {} as the payload, with user properties.

Arguments

• topic - The topic to publish to
• error_message - The error message to send in the DebugMessage user property.
• correlation_id - The correlation id for matching requests
• return_code - The return code to send in the ReturnCode user property

Returns

Returns a receiver that will be notified when the message is acknowledged by the broker.

pub async fn publish_state<T: Serialize>( &self, topic: String, payload: T, state_version: u32, ) -> Receiver<PublishResult>

Publish a state message to a topic. Adds a user property PropertyVersion to the message properties.

Arguments

• topic - The topic to publish to
• payload - The serializable struct to send as payload

Returns

Returns a receiver that will be notified when the message is acknowledged by the broker

pub async fn publish_status<T: Serialize>( &self, topic: String, payload: T, expiry_secs: u32, ) -> Receiver<PublishResult>

pub async fn run_loop(&self) -> Result<(), MqttierError>

Start the run loop for handling MQTT connections and messages

Trait Implementations

impl Clone for MqttierClient

fn clone(&self) -> MqttierClient

Returns a duplicate of the value.

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

Performs copy-assignment from source.