[Ns-developers] Extending WifiHelper object

[Mathieu Lacage]

On Wed, 2009-03-25 at 11:15 +0100, Mirko Banchi wrote:

> >> As you can see the main problems are with parameter list of
> >>
> >> NqosWifiMacHelper::SetDcaParameter
> >> QosWifiMacHelper::SetEdcaParameter
> >>
> >> Which kind of parameter we should use?
> >>
> >> Even if ns3::EdcaTxopN has attributes like "MinCw", "MaxCw" etc, when
> >> SetEdcaParameter is called i haven't in hand the pointer to the specific
> >> queue yet.
> > 
> > Can you do what you do already for SetMsduAggregatorForAc with a factory
> > and create the EdcaTxop object from the helper rather than from the
> > WifiMac object ?
> > 
> 
> It's a problem :( Because EdcaTxopN needs to know for which type of
> WifiMac objects is created. For example in QapWifiMac constructor:

None of the below seem to be problematic: why can't you do this:

class QosWifiMacHelper
{
public:
  void SetEdcaParameter (AccessClass ac,
                         std::string n0, const AttributeValue &v0,
                         ...) {
    if (ac == VO) {
      m_voEdcaFactory.Set (n0, v0);
    }
  }
  ... Install (...) {
    vo_edca = m_voEdcaFactory.Create... ();
    mac->SetVoEdca (vo_edca); // or mac->SetAttribute (..., PointerValue
(vo_edca);
  }
private:
  ObjectFactory m_voEdcaFactory;
};

> 
> QapWifiMac::QapWifiMac ()
> {
>   ...
>   m_voEdcaTxopN->SetTxOkCallback (MakeCallback (&QapWifiMac::TxOk,
>                                                 this));
>   m_voEdcaTxopN->SetTypeOfStation (AP);
>   ....
> }