Struct ReaderBuilder 

pub struct ReaderBuilder<'a, E: Engine = TokioEngine> { /* private fields */ }

Builder for a Reader.

Mirrors org.apache.pulsar.client.api.ReaderBuilder. Internally a Reader is just a non-durable Exclusive consumer with an auto-generated subscription name — there’s no dedicated wire command, so the protocol layer doesn’t need any extra plumbing.

Phantom-generic over E: Engine (defaults to crate::TokioEngine). Wraps a ConsumerBuilder<E>; the impl methods stay tokio-bound until the SubscribeApi dispatch path lands in the Builder lift sub-PR.

Implementations

impl<'a, E: Engine> ReaderBuilder<'a, E>

pub fn subscription_name(self, name: impl Into<String>) -> Self

Override the auto-generated subscription name. Rarely needed — Reader subscriptions are not visible on the broker dashboard anyway.

pub fn receiver_queue_size(self, size: usize) -> Self

Set the receiver queue size.

pub fn name(self, name: impl Into<String>) -> Self

Set the consumer name advertised to the broker.

pub fn start_position(self, position: InitialPosition) -> Self

Choose where the reader starts when its non-durable subscription is fresh. Defaults to pb::command_subscribe::InitialPosition::Latest.

pub fn read_compacted(self, on: bool) -> Self

Read from the compacted (key-deduplicated) view of the topic. Mirrors Java ReaderBuilder#readCompacted. Required for compacted-topic readers.

pub fn start_message_id(self, id: MessageId) -> Self

Override the initial message id the reader starts from. Mirrors Java ReaderBuilder#startMessageId. Pass magnetar_proto::MessageId::EARLIEST / magnetar_proto::MessageId::LATEST for the sentinel positions.

pub fn property(self, key: impl Into<String>, value: impl Into<String>) -> Self

Mirrors ConsumerBuilder::property. The reader’s underlying consumer carries the (key, value) pair on its CommandSubscribe.metadata.

pub fn start_message_rollback_duration(self, seconds: u64) -> Self

Roll the reader cursor back by seconds at create time. Mirrors Java ReaderBuilder#startMessageIdInclusive rollback knob.

pub async fn create( self, ) -> Result<Reader<<E::ClientState as SubscribeApi>::Consumer>, PulsarError>

where E::ClientState: SubscribeApi,

Create the reader via the engine-generic crate::SubscribeApi dispatch path. Returns Reader<<E::ClientState as SubscribeApi>::Consumer> — resolves to Reader<magnetar_runtime_tokio::Consumer> (the default Reader<> alias) under the default E = TokioEngine.

Errors

• PulsarError::Other on broker rejection or wire failure.

impl ReaderBuilder<'_, TokioEngine>

Tokio-engine-specific ReaderBuilder methods that depend on the tokio MessageDecryptor extension (PIP-4).

pub fn encryption(self, decryptor: Arc<dyn MessageDecryptor>) -> Self

Mirrors Java ReaderBuilder#cryptoKeyReader — supplies a PIP-4 decryptor for the reader’s underlying subscription.

Trait Implementations

impl<E: Engine> Debug for ReaderBuilder<'_, E>

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

Formats the value using the given formatter.