Function report_populate_active 

pub fn report_populate_active(
    connection: &mut PgConnection,
    corpus_id: i32,
    service_id: i32,
    severity: &str,
) -> bool

Whether a populate job for exactly this (corpus, service, severity) slice is already queued or running — the request path’s pre-check, so a burst of viewers of a still-computing report doesn’t each re-attempt the (bounded) inline aggregation while the background job is already on it.