fn send_stream_get_frame_data()

in neqo-transport/src/send_stream.rs [2588:2673]

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

    fn send_stream_get_frame_data() {
        let conn_fc = connection_fc(100);
        let conn_events = ConnectionEvents::default();

        let mut s = SendStream::new(0.into(), 100, conn_fc, conn_events);
        s.send(&[0; 10]).unwrap();
        s.close();

        let mut ss = SendStreams::default();
        ss.insert(StreamId::from(0), s);

        let mut tokens = Vec::new();
        let mut builder = PacketBuilder::short(Encoder::new(), false, None::<&[u8]>);

        // Write a small frame: no fin.
        let written = builder.len();
        builder.set_limit(written + 6);
        ss.write_frames(
            TransmissionPriority::default(),
            &mut builder,
            &mut tokens,
            &mut FrameStats::default(),
        );
        assert_eq!(builder.len(), written + 6);
        assert_eq!(tokens.len(), 1);
        let f1_token = tokens.remove(0);
        assert!(!as_stream_token(&f1_token).fin);

        // Write the rest: fin.
        let written = builder.len();
        builder.set_limit(written + 200);
        ss.write_frames(
            TransmissionPriority::default(),
            &mut builder,
            &mut tokens,
            &mut FrameStats::default(),
        );
        assert_eq!(builder.len(), written + 10);
        assert_eq!(tokens.len(), 1);
        let f2_token = tokens.remove(0);
        assert!(as_stream_token(&f2_token).fin);

        // Should be no more data to frame.
        let written = builder.len();
        ss.write_frames(
            TransmissionPriority::default(),
            &mut builder,
            &mut tokens,
            &mut FrameStats::default(),
        );
        assert_eq!(builder.len(), written);
        assert!(tokens.is_empty());

        // Mark frame 1 as lost
        ss.lost(as_stream_token(&f1_token));

        // Next frame should not set fin even though stream has fin but frame
        // does not include end of stream
        let written = builder.len();
        ss.write_frames(
            TransmissionPriority::default() + RetransmissionPriority::default(),
            &mut builder,
            &mut tokens,
            &mut FrameStats::default(),
        );
        assert_eq!(builder.len(), written + 7); // Needs a length this time.
        assert_eq!(tokens.len(), 1);
        let f4_token = tokens.remove(0);
        assert!(!as_stream_token(&f4_token).fin);

        // Mark frame 2 as lost
        ss.lost(as_stream_token(&f2_token));

        // Next frame should set fin because it includes end of stream
        let written = builder.len();
        ss.write_frames(
            TransmissionPriority::default() + RetransmissionPriority::default(),
            &mut builder,
            &mut tokens,
            &mut FrameStats::default(),
        );
        assert_eq!(builder.len(), written + 10);
        assert_eq!(tokens.len(), 1);
        let f5_token = tokens.remove(0);
        assert!(as_stream_token(&f5_token).fin);
    }