Struct SessionExitHandle

pub struct SessionExitHandle(/* private fields */);

Handle used to end an MQTT session.

PLEASE NOTE WELL This struct’s API is designed around negotiating a graceful exit with the MQTT broker. However, this is not actually possible right now due to a bug in underlying MQTT library.

Implementations

impl SessionExitHandle

pub async fn try_exit(&self) -> Result<(), SessionExitError>

Attempt to gracefully end the MQTT session running in the Session that created this handle. This will cause the Session::run() method to return.

Note that a graceful exit requires the Session to be connected to the broker. If the Session is not connected, this method will return an error. If the Session connection has been recently lost, the Session may not yet realize this, and it can take until up to the keep-alive interval for the Session to realize it is disconnected, after which point this method will return an error. Under this circumstance, the attempt was still made, and may eventually succeed even if this method returns the error

Errors

• SessionExitError of kind SessionExitErrorKind::Detached if the Session no longer exists.
• SessionExitError of kind SessionExitErrorKind::BrokerUnavailable if the Session is not connected to the broker.

pub async fn try_exit_timeout( &self, timeout: Duration, ) -> Result<(), SessionExitError>

Attempt to gracefully end the MQTT session running in the Session that created this handle. This will cause the Session::run() method to return.

Note that a graceful exit requires the Session to be connected to the broker. If the Session is not connected, this method will return an error. If the Session connection has been recently lost, the Session may not yet realize this, and it can take until up to the keep-alive interval for the Session to realize it is disconnected, after which point this method will return an error. Under this circumstance, the attempt was still made, and may eventually succeed even if this method returns the error If the graceful Session exit attempt does not complete within the specified timeout, this method will return an error.

Arguments

• timeout - The duration to wait for the graceful exit to complete before returning an error.

Errors

• SessionExitError of kind SessionExitErrorKind::Detached if the Session no longer exists.
• SessionExitError of kind SessionExitErrorKind::BrokerUnavailable if the Session is not connected to the broker within the specified timeout interval.

pub async fn exit_force(&self) -> bool

Forcefully end the MQTT session running in the Session that created this handle. This will cause the Session::run() method to return.

The Session will be granted a period of 1 second to attempt a graceful exit before forcing the exit. If the exit is forced, the broker will not be aware the MQTT session has ended.

Returns true if the exit was graceful, and false if the exit was forced.

Trait Implementations

impl Clone for SessionExitHandle

fn clone(&self) -> SessionExitHandle

Returns a copy of the value.

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

Performs copy-assignment from source.