Struct BarrierAlignment 

pub struct BarrierAlignment { /* private fields */ }

Tells a stream thread which barrier group to align on.

Pass one to StreamsApp or to KafkaStreams. The thread then reads the group’s cuts from __barrier_state, holds back every record at or above each partition’s marker offset, and fires the barrier when every assigned partition reaches the cut. At that point it snapshots each task under the cut’s epoch, commits the cut offsets, and calls the listener.

Examples

use std::sync::Arc;

use krabka_client_streams::{
    barrier::{Barrier, BarrierAlignment},
    store::snapshot::FileSnapshotStore,
};

let snapshots = Arc::new(FileSnapshotStore::new("/var/lib/app/state"));
let alignment = BarrierAlignment::on("transactions", snapshots).with_listener(Arc::new(
    |barrier: &Barrier| {
        println!("epoch {}", barrier.cut.epoch);
    },
));

Implementations

impl BarrierAlignment

pub fn on(group: impl Into<String>, snapshots: Arc<dyn SnapshotStore>) -> Self

Aligns on the cuts of group and keeps each cut’s snapshot in snapshots.

pub fn with_listener(self, listener: Arc<dyn BarrierListener>) -> Self

Adds the callback the thread calls after each barrier commit.

pub fn group(&self) -> &str

The barrier group this alignment reads.

pub fn snapshots(&self) -> &Arc<dyn SnapshotStore>

The store that keeps each cut’s snapshot.

pub fn listener(&self) -> Option<&Arc<dyn BarrierListener>>

The callback the thread calls after each barrier commit, when one is set.

Trait Implementations

impl Clone for BarrierAlignment

fn clone(&self) -> BarrierAlignment

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for BarrierAlignment

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

Formats the value using the given formatter.