Struct PulsarMessage 

pub struct PulsarMessage { /* private fields */ }

A message delivered by a PulsarSubscriber.

ack acknowledges; nack(requeue = true) asks the broker to redeliver, which is what drives the delivery count towards the subscription’s dead-letter policy. nack(requeue = false) acknowledges too: Pulsar settles a message by acknowledging it or asking for it again, and a poison message leaves through the dead-letter policy, reached by repeated redelivery. The client queues acknowledgements asynchronously, so Ok means “queued”, not “broker confirmed”.

nack_after(delay) is the delayed form, and the delay is this process’s: Pulsar’s negative acknowledgement carries none, so the delivery is held unacknowledged until the delay is over and the negative acknowledgement goes out then. The redelivery itself is the broker’s, and so is the count it advances.

Implementations

impl PulsarMessage

pub fn topic(&self) -> &str

The topic this message arrived on, named the way its subscription named it: as written in PulsarSubscription::new or topics, and by its full name for a pattern, whose topics the client finds by listing their full names. A partitioned topic adds its partition suffix.

Trait Implementations

impl BuildBatchContext<PulsarMessage> for PulsarBatchContext

fn build(first: &PulsarMessage) -> Self

Builds the context value by reading subscription-scoped fields out of the batch’s first delivery, or out of the batch itself where it lends its values as one slice.

impl BuildContext<PulsarMessage> for PulsarContext

fn build(msg: &PulsarMessage) -> Self

Builds the context value by reading fields out of msg.

impl Debug for PulsarMessage

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

Formats the value using the given formatter.

impl IncomingMessage for PulsarMessage

fn supports_nack_after(&self) -> bool

The delay is kept by this process rather than by the broker, and that is still native delayed redelivery as far as the framework is concerned: no copy of the message is published, and the redelivery that follows is the broker’s own, counted by the consumer’s dead-letter policy like any other.

fn nack_after( self, delay: Duration, ) -> impl Future<Output = Result<(), AckError>> + Send

Holds the delivery unacknowledged for delay, then negatively acknowledges it so the broker redelivers.

The wait runs on a task of its own, started by the subscription’s driver on the runtime the broker connected on: the dispatch loop must not stop for it, and a handler on a dedicated thread may settle from a runtime that stops before the delay is out. The delivery’s settlement channel keeps the driver alive until the wait is over. Ok therefore means the delay was accepted, not that the redelivery has happened yet.

Errors

Returns AckError::Broker when the delay is not shorter than the subscription’s ack_timeout, which would redeliver the message before the delay was over, or when the subscription is gone (its driver task has shut down, or in process the broker did).

Cancel safety

At-most-once over the delay window: the message is unacknowledged throughout, so a process that exits before the wait ends loses only the wait. The broker redelivers the message once the consumer’s ack_timeout elapses, and at once where the consumer disconnects.

fn payload(&self) -> &[u8]

Returns the raw payload of the message.

fn headers(&self) -> &HeaderMap

Returns the headers attached to the message.

async fn ack(self) -> Result<(), AckError>

Acknowledges successful processing. Consumes the message handle.

async fn nack(self, requeue: bool) -> Result<(), AckError>

Negatively acknowledges the message. When requeue is true the broker should redeliver according to its own retry policy; when false it should drop or dead-letter the message.

fn partition_key(&self) -> Option<&[u8]>

Returns the routing key the broker partitioned this message by, or None when the message carries no key.

fn redelivery_count(&self) -> Option<u64>

How many times the broker has delivered this message, counting this delivery. None where the transport counts nothing.

fn decode_error(&self) -> Option<&CodecError>

The error the broker met while reading this delivery, or None when it read the delivery whole.

impl Partitioned for PulsarMessage

fn partition_key(&self) -> Option<&[u8]>

Returns the partition key for this item, or None if the broker should pick a partition.

impl Positioned for PulsarMessage

type Position = PulsarPosition

The position type, matching the subscription’s Seeker::Position.

fn position(&self) -> PulsarPosition

Returns the position of this delivery; seeking to it redelivers this message.