Function prefetch

opensuse-proxy-cache/src/main.rs:1092–1119

(
    prefetch_tx: Sender<PrefetchReq>,
    submit_tx: &Sender<CacheMeta>,
    prefetch_paths: Option<Vec<PrefetchItem>>,
)

#[instrument(skip_all)]
fn prefetch(
    prefetch_tx: Sender<PrefetchReq>,
    submit_tx: &Sender<CacheMeta>,
    prefetch_paths: Option<Vec<PrefetchItem>>,
) {
    if let Some(prefetch) = prefetch_paths {
        for PrefetchItem {
            fetch_url,
            cache_key,
            tmp_file,
            cls,
        } in prefetch.into_iter()
        {
            if prefetch_tx
                .try_send(PrefetchReq {
                    fetch_url,
                    cache_key,
                    tmp_file,
                    submit_tx: submit_tx.clone(),
                    cls,
                })
                .is_err()
            {
                error!("Prefetch task may have died!");
            }
        }
    }
}

#[instrument(skip_all)]
async fn prefetch_dl_task(