Enum SessionPolicy 

#[non_exhaustive]
pub enum SessionPolicy {
    CleanPerConnection,
    Resume,
    ResumeFor(Duration),
}

What happens to the MQTT session across connections.

Modeled on MQTT 5 semantics (clean_start + session expiry) with a documented MQTT 3.1.1 mapping, per the dual-protocol API design.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

CleanPerConnection

Start fresh on every connect; the broker discards state on disconnect.

v4: clean_session = true. v5: clean_start = true, session expiry 0.

Resume

Resume the previous session; the broker keeps state indefinitely.

v4: clean_session = false. v5: clean_start = false, session never expires. Requires a non-empty client_id.

ResumeFor(Duration)

Resume the previous session; the broker keeps state for the given time after disconnect.

MQTT 5 only (session expiry interval, rounded up to whole seconds). On MQTT 3.1.1 this is not representable and connect returns a configuration error rather than silently degrading.

Trait Implementations

impl Clone for SessionPolicy

fn clone(&self) -> SessionPolicy

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for SessionPolicy

impl Debug for SessionPolicy

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

Formats the value using the given formatter.

impl Default for SessionPolicy

fn default() -> SessionPolicy

Returns the “default value” for a type.

impl Eq for SessionPolicy

impl PartialEq for SessionPolicy

fn eq(&self, other: &SessionPolicy) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for SessionPolicy