fn remove_lost_packets_persistent_congestion_path_aware()

in quic/s2n-quic-transport/src/recovery/manager/tests.rs [1882:2014]

• 124 lines of code
• 1 McCabe index (conditional complexity)

fn remove_lost_packets_persistent_congestion_path_aware() {
    // Setup:
    let space = PacketNumberSpace::ApplicationData;
    let mut publisher = Publisher::snapshot();
    let (_first_addr, first_path_id, _second_addr, second_path_id, mut manager, mut path_manager) =
        helper_generate_multi_path_manager(space, &mut publisher);
    let ecn = ExplicitCongestionNotification::default();
    let mut context = MockContext::new(&mut path_manager);
    let mut now = time::now();
    let random = &mut random::testing::Generator::default();

    assert_eq!(
        context
            .path_by_id(first_path_id)
            .congestion_controller
            .persistent_congestion,
        None
    );
    assert_eq!(
        context
            .path_by_id(second_path_id)
            .congestion_controller
            .persistent_congestion,
        None
    );

    // create first rtt samples so we can check it later
    context
        .path_mut_by_id(first_path_id)
        .rtt_estimator
        .update_rtt(
            Duration::from_secs(0),
            Duration::from_secs(0),
            now,
            true,
            space,
        );
    context
        .path_mut_by_id(second_path_id)
        .rtt_estimator
        .update_rtt(
            Duration::from_secs(0),
            Duration::from_secs(0),
            now,
            true,
            space,
        );
    assert!(context
        .path_by_id(first_path_id)
        .rtt_estimator
        .first_rtt_sample()
        .is_some());
    assert!(context
        .path_by_id(second_path_id)
        .rtt_estimator
        .first_rtt_sample()
        .is_some());

    now += Duration::from_secs(10);
    let sent_packets_to_remove = PacketNumberRange::new(
        space.new_packet_number(VarInt::from_u8(9)),
        space.new_packet_number(VarInt::from_u8(10)),
    );
    context.set_path_id(first_path_id);
    manager.on_packet_sent(
        sent_packets_to_remove.start(),
        Outcome {
            ack_elicitation: AckElicitation::Eliciting,
            is_congestion_controlled: true,
            bytes_sent: 1,
            bytes_progressed: 0,
        },
        now,
        ecn,
        transmission::Mode::Normal,
        None,
        &mut context,
        &mut publisher,
    );
    context.set_path_id(second_path_id);
    manager.on_packet_sent(
        sent_packets_to_remove.end(),
        Outcome {
            ack_elicitation: AckElicitation::Eliciting,
            is_congestion_controlled: true,
            bytes_sent: 1,
            bytes_progressed: 0,
        },
        now,
        ecn,
        transmission::Mode::Normal,
        None,
        &mut context,
        &mut publisher,
    );

    // Trigger:
    context.set_path_id(second_path_id);
    manager.remove_lost_packets(
        now,
        Duration::from_secs(20),
        sent_packets_to_remove,
        random,
        &mut context,
        &mut publisher,
    );

    // Expectation:
    assert_eq!(
        context
            .path_by_id(first_path_id)
            .congestion_controller
            .persistent_congestion,
        Some(false)
    );
    assert!(context
        .path_by_id(first_path_id)
        .rtt_estimator
        .first_rtt_sample()
        .is_some());
    assert_eq!(
        context
            .path_by_id(second_path_id)
            .congestion_controller
            .persistent_congestion,
        Some(true)
    );
    assert!(context
        .path_by_id(second_path_id)
        .rtt_estimator
        .first_rtt_sample()
        .is_none());
}