Struct FileContext 

pub struct FileContext { /* private fields */ }

The file transport’s per-delivery context: this delivery’s position in the stream file, and the subscription’s own seeker.

The runtime builds one per delivery, and handlers read its fields by key - Position and SeekHandle. A handler that reads both, or that reads them on the manual path, names this type as its context.

Examples

use ruststream_sea_file::file::prelude::*;
use serde::Deserialize;

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

#[subscriber(FileStream::new("jobs"))]
async fn work(job: &Job, ctx: &mut Context<'_, FileContext>) -> HandlerOutcome {
    if job.id == 0 && ctx.context(SeekHandle).seek(FilePosition::end()).await.is_err() {
        return HandlerOutcome::retry();
    }
    tracing::info!(job.id, position = ?ctx.context(Position), "worked");
    HandlerOutcome::ack()
}

#[ruststream::app]
fn app() -> impl App {
    RustStream::new(AppInfo::new("jobs", "0.1.0"))
        .with_broker(FileBroker::new("/tmp/jobs.ss"), |b| {
            b.include(work);
        })
}

Trait Implementations

impl BuildContext<FileMessage> for FileContext

fn build(msg: &FileMessage) -> Self

Builds the context value by reading fields out of msg.

impl Debug for FileContext

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

Formats the value using the given formatter.

impl Field<FileContext> for Position

type Value<'a> = FilePosition

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

fn get(self, src: &FileContext) -> FilePosition

Reads this key’s field out of src.

impl Field<FileContext> for SeekHandle

type Value<'a> = &'a FileSeeker

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

fn get(self, src: &FileContext) -> &FileSeeker

Reads this key’s field out of src.