fn create_audiounit()

in src/backend/mod.rs [1217:1270]
47 lines of code
8 McCabe index (conditional complexity)

fn create_audiounit(device: &device_info) -> Result<AudioUnit> {
    assert!(device
        .flags
        .intersects(device_flags::DEV_INPUT | device_flags::DEV_OUTPUT));
    assert!(!device
        .flags
        .contains(device_flags::DEV_INPUT | device_flags::DEV_OUTPUT));
    debug_assert_running_serially();

    let unit = create_blank_audiounit()?;
    let mut bus = AU_OUT_BUS;

    if device.flags.contains(device_flags::DEV_INPUT) {
        // Input only.
        if let Err(e) = enable_audiounit_scope(unit, DeviceType::INPUT, true) {
            cubeb_log!("Failed to enable audiounit input scope. Error: {}", e);
            dispose_audio_unit(unit);
            return Err(Error::error());
        }
        if let Err(e) = enable_audiounit_scope(unit, DeviceType::OUTPUT, false) {
            cubeb_log!("Failed to disable audiounit output scope. Error: {}", e);
            dispose_audio_unit(unit);
            return Err(Error::error());
        }
        bus = AU_IN_BUS;
    }

    if device.flags.contains(device_flags::DEV_OUTPUT) {
        // Output only.
        if let Err(e) = enable_audiounit_scope(unit, DeviceType::OUTPUT, true) {
            cubeb_log!("Failed to enable audiounit output scope. Error: {}", e);
            dispose_audio_unit(unit);
            return Err(Error::error());
        }
        if let Err(e) = enable_audiounit_scope(unit, DeviceType::INPUT, false) {
            cubeb_log!("Failed to disable audiounit input scope. Error: {}", e);
            dispose_audio_unit(unit);
            return Err(Error::error());
        }
        bus = AU_OUT_BUS;
    }

    if let Err(e) = set_device_to_audiounit(unit, device.id, bus) {
        cubeb_log!(
            "Failed to set device {} to the created audiounit. Error: {}",
            device.id,
            e
        );
        dispose_audio_unit(unit);
        return Err(Error::error());
    }

    Ok(unit)
}