Struct PulsarContext 

pub struct PulsarContext { /* private fields */ }

The per-delivery context of a Pulsar subscription: this message’s position in the topic’s retained log, and the subscription’s own seeker.

The runtime builds one per dispatched delivery (see BuildContext), and handlers read its fields by key - Position and SeekHandle - through the Ctx extractor or ctx.context(..). A body that repositions its own subscription names this type as its C axis and needs nothing else.

Building it costs no allocation: the position is the delivery’s message id, and the seeker is a clone of the channel to the subscription’s driver task.

Examples

use ruststream_pulsar::prelude::*;
use serde::Deserialize;

#[derive(Deserialize)]
struct Job {
    id: u64,
    rewind: bool,
}

/// Logs where each job sits, and replays the retained backlog when a job asks for it.
#[subscriber(PulsarSubscription::new("jobs", "workers"))]
async fn work(job: &Job, ctx: &mut Context<'_, PulsarContext>) -> HandlerOutcome {
    tracing::info!(job = job.id, position = ?ctx.context(Position), "job received");
    if job.rewind
        && ctx
            .context(SeekHandle)
            .seek(PulsarPosition::earliest())
            .await
            .is_err()
    {
        return HandlerOutcome::retry();
    }
    HandlerOutcome::ack()
}

Trait Implementations

impl BuildContext<PulsarMessage> for PulsarContext

fn build(msg: &PulsarMessage) -> Self

Builds the context value by reading fields out of msg.

impl Debug for PulsarContext

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

Formats the value using the given formatter.

impl Field<PulsarContext> for Position

type Value<'a> = &'a PulsarPosition

The value read through this key, borrowed from the source for 'a.

fn get(self, src: &PulsarContext) -> &PulsarPosition

Reads this key’s field out of src.

impl Field<PulsarContext> for SeekHandle

type Value<'a> = &'a PulsarSeeker

The value read through this key, borrowed from the source for 'a.

fn get(self, src: &PulsarContext) -> &PulsarSeeker

Reads this key’s field out of src.