Struct KafkaTopic 

pub struct KafkaTopic { /* private fields */ }

A subscription to one Kafka topic through one consumer group.

Everything except the topic name is optional; unset options fall back to the librdkafka defaults (this crate does not impose its own). The group can also come from KafkaBroker::default_group; a subscription that ends up with no group at all is a startup error, because Kafka cannot subscribe without one.

Examples

use ruststream_rdkafka::{Commit, KafkaTopic, StartOffset};

let topic = KafkaTopic::new("orders")
    .group("orders-svc")
    .start(StartOffset::Earliest)
    .commit(Commit::Tracked)
    .config("fetch.min.bytes", "1024");
assert_eq!(topic.topic(), "orders");

Implementations

impl KafkaTopic

pub fn new(topic: impl Into<String>) -> Self

Describes a subscription to topic with librdkafka defaults for everything else.

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

The consumer group for this subscription, overriding KafkaBroker::default_group.

pub fn start(self, start: StartOffset) -> Self

Where the group starts when it has no committed offset (see StartOffset).

pub fn commit(self, commit: Commit) -> Self

How processed deliveries are committed (see Commit).

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

Raw librdkafka consumer property passthrough for anything not surfaced as a typed option, applied last (it wins over the typed options and the broker-wide config).

pub fn topic(&self) -> &str

The topic this subscription consumes.

Trait Implementations

impl Clone for KafkaTopic

fn clone(&self) -> KafkaTopic

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for KafkaTopic

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

Formats the value using the given formatter.

impl SubscriptionSource<KafkaBroker> for KafkaTopic

type Subscriber = KafkaSubscriber

The subscriber type this source opens.

fn name(&self) -> &str

The name (subject / channel) this subscription binds to.

async fn subscribe( self, broker: &KafkaBroker, ) -> Result<Self::Subscriber, KafkaError>

Opens the subscription against broker. Called once, after Broker::connect.

impl SubscriptionSource<KafkaTestBroker> for KafkaTopic

Available on crate feature testing only.

type Subscriber = KafkaTestSubscriber

The subscriber type this source opens.

fn name(&self) -> &str

The name (subject / channel) this subscription binds to.

async fn subscribe( self, broker: &KafkaTestBroker, ) -> Result<Self::Subscriber, KafkaError>

Opens the subscription against broker. Called once, after Broker::connect.