Struct MqttConfig 

pub struct MqttConfig { /* private fields */ }

Connection settings for an MqttTransport.

Construct with MqttConfig::new and refine with the chained setters; every field has a sensible default so only the broker address and client id are required.

Implementations

impl MqttConfig

pub fn new( client_id: impl Into<String>, host: impl Into<String>, port: u16, ) -> Self

Creates a configuration for the given client id and broker address.

Arguments

• client_id - the MQTT client identifier presented to the broker.
• host - the broker hostname or IP address.
• port - the broker TCP port, conventionally 1883 for plaintext MQTT.

Returns

A configuration with a 30-second keep-alive, a request capacity of 64, a default quality of service of QualityOfService::AtLeastOnce, and a packet limit of DEFAULT_MAX_PACKET_SIZE.

pub fn credentials( self, username: impl Into<String>, password: impl Into<String>, ) -> Self

Signs in to the broker with a username and password.

The password travels in the clear unless the connection uses TLS, so a broker reached over a network worth protecting wants both.

Arguments

• username - the name the broker knows the client by.
• password - its password.

Returns

The updated configuration, for chaining.

pub fn last_will(self, will: Will) -> Self

Leaves a message for the broker to publish if the connection ends without a DISCONNECT.

Arguments

• will - the message, its topic, and how it is published.

Returns

The updated configuration, for chaining.

pub fn tls(self, tls: Tls) -> Self

Secures the connection with TLS.

Arguments

• tls - the authorities to trust, and any client certificate to present.

Returns

The updated configuration, for chaining.

pub fn username(&self) -> Option<&str>

Returns the username the client signs in with.

Returns

The username, or None for a client that does not sign in.

pub fn will(&self) -> Option<&Will>

Returns the will the broker holds for this client.

Returns

The will, or None when there is none.

pub fn uses_tls(&self) -> bool

Returns whether the connection uses TLS.

Returns

true once tls has been set.

pub fn max_packet_size(self, bytes: usize) -> Self

Sets the largest packet the connection sends or accepts, in bytes.

A packet is a message’s topic and payload plus a few bytes of framing. A send whose packet would be larger is refused and the connection stays up, but a larger packet arriving from the broker ends the connection, so every client that shares a topic needs a limit that fits it. MQTT itself allows a packet of up to 268,435,455 bytes after its fixed header.

Arguments

• bytes - the limit, which applies to both directions.

Returns

The updated configuration, for chaining.

pub fn keep_alive(self, interval: Duration) -> Self

Sets the keep-alive interval used to hold the connection open.

Arguments

• interval - how often the client pings the broker when otherwise idle.

Returns

The updated configuration, for chaining.

pub fn capacity(self, capacity: usize) -> Self

Sets the bound on outstanding client requests buffered toward the broker.

Arguments

• capacity - the request channel capacity; values below one are clamped to one.

Returns

The updated configuration, for chaining.

pub fn qos(self, qos: QualityOfService) -> Self

Sets the default quality of service for publishes and subscriptions.

Arguments

• qos - the delivery guarantee applied by send and subscribe.

Returns

The updated configuration, for chaining.

Trait Implementations

impl Clone for MqttConfig

fn clone(&self) -> MqttConfig

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for MqttConfig

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

Formats the value using the given formatter.