Struct Subscription 

pub struct Subscription { /* private fields */ }

A lightweight handle returned from Connection::subscribe that packages the subscription id, destination, and the receiving side of the subscription.

The Subscription provides convenience helpers for acknowledging or negative-acknowledging messages; these delegate to the underlying Connection handle.

Implementations

impl Subscription

pub fn id(&self) -> &str

Returns the local subscription id.

pub fn destination(&self) -> &str

Returns the destination this subscription listens to.

pub fn into_receiver(self) -> Receiver<Frame>

Consume the Subscription and return the underlying receiver so the caller can drive message handling directly.

The subscription stays active: the caller now owns the stream, so Drop does not send an UNSUBSCRIBE. Call Connection::unsubscribe with the id if you later want to stop it.

pub async fn ack(&self, message_id: &str) -> Result<(), ConnError>

Acknowledge a message by its message-id header. Delegates to Connection::ack using the local subscription id.

pub async fn nack(&self, message_id: &str) -> Result<(), ConnError>

Negative-acknowledge a message by its message-id header.

pub async fn unsubscribe(self) -> Result<(), ConnError>

Consume the subscription and unsubscribe from the server.

This is a convenience that calls Connection::unsubscribe with the local subscription id and drops the receiver. It confirms nothing beyond queuing the UNSUBSCRIBE; the returned error means either the id was no longer registered locally (for example the subscription had already been abandoned after repeated broker errors) or the frame could not be queued. Dropping the handle instead does the same thing on a best-effort basis (see the Drop impl).

Trait Implementations

impl Drop for Subscription

fn drop(&mut self)

Best-effort UNSUBSCRIBE when the handle is dropped without an explicit unsubscribe.

A dropped handle means the caller is done receiving, so the broker-side subscription should stop rather than linger and keep delivering (and be replayed on reconnect). Drop cannot .await, so this is best-effort via Connection::unsubscribe_best_effort. It is skipped when the subscription was already unsubscribed or when the receiver was handed off through into_receiver.

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.

impl Stream for Subscription

type Item = Frame

Values yielded by the stream.

fn poll_next( self: Pin<&mut Self>, cx: &mut Context<'_>, ) -> Poll<Option<Self::Item>>

Attempt to pull out the next value of this stream, registering the current task for wakeup if the value is not yet available, and returning None if the stream is exhausted.

fn size_hint(&self) -> (usize, Option<usize>)

Returns the bounds on the remaining length of the stream.