Struct Subscription 

pub struct Subscription { /* private fields */ }

A live attribute subscription. Await events with Self::next; dropping the handle cancels the subscription (best-effort).

Steady-state SubscriptionEvent::Reports are buffered in a bounded channel (capacity SUBSCRIPTION_CHANNEL_CAP, 256) so a device — whose reporting cadence and per-report size are attacker-controlled — cannot drive unbounded controller memory growth. If the consumer does not call Self::next promptly and the buffer fills, excess reports are dropped and a SubscriptionEvent::Lagged event reports how many were lost.

Control events (SubscriptionEvent::Established and SubscriptionEvent::Resubscribing) travel on a separate, low-volume channel and are delivered reliably even while reports are being dropped; they are also prioritised by Self::next.

Implementations

impl Subscription

pub async fn next(&mut self) -> Option<SubscriptionEvent>

Await the next subscription event, or None once the subscription has ended (cancelled, or the controller task stopped).

Control events (SubscriptionEvent::Established / SubscriptionEvent::Resubscribing) are prioritised over buffered reports, so a re-establishment is observed promptly even behind a backlog.

pub async fn cancel(self) -> Result<(), Error>

Cancel the subscription explicitly and stop receiving reports.

Errors

Returns Error::ControllerStopped if the owning task has already stopped (the subscription is effectively cancelled either way).

Trait Implementations

impl Drop for Subscription

fn drop(&mut self)

Executes the destructor for this type.

fn pin_drop(self: Pin<&mut Self>)

🔬This is a nightly-only experimental API. (pin_ergonomics)

Execute the destructor for this type, but different to Drop::drop, it requires self to be pinned.