Function mz_storage::render::upsert::stage_input

fn stage_input<T, O>(
    stash: &mut Vec<(T, UpsertKey, Reverse<O>, Option<Result<Row, UpsertError>>)>,
    data: &mut Vec<((UpsertKey, Option<Result<Row, UpsertError>>, O), T, Diff)>,
    input_upper: &Antichain<T>,
    resume_upper: &Antichain<T>,
    storage_shrink_upsert_unused_buffers_by_ratio: usize
)where
    T: PartialOrder,
    O: Ord,

Helper method for upsert_inner used to stage data updates from the input timely edge.