genericbte.java

一个小型网络仿真器的实现

        else {
          String comptype=(String)paramlist;
          java.util.List targets=new java.util.ArrayList();
          for(i=0;i<intports.length;i++) {
            SimComponent thecomp=(SimComponent)app_ports.get(intports[i]);
            if(thecomp.getClass().getName().equals(comptype)) targets.add(intports[i]);
          }
          return (Integer [])targets.toArray(new Integer[0]);
        }
    }
    return null;
  }

///////////////////// private methods ////////////////////////////////

  private void b_create() {
    b_cell_count=0;

    records=new java.util.HashMap();
    r_records=new java.util.HashMap();
    ftable=new java.util.HashMap();
    r_ftable=new java.util.HashMap();

    //Initialize the parameters
    long ctick=theSim.now();
    b_oqsize=new SimParamInt("Max Output Queue Size (-1=inf)",this,ctick,false,true,-1);
    b_log_factor=new SimParamInt("Logging every (ticks) (e.g. 1, 100)",this,ctick,false,true,0);
    b_cc=new SimParamInt("Cells Received",this,ctick,true,false,0);

    addParameter(b_oqsize);
    addParameter(b_log_factor);
    addParameter(b_cc);

    app_ports=new java.util.HashMap();
  }

  private void b_ready(SimEvent e) {
    if(voport!=null && voport.to_link==e.getSource()) {
      voport.link_busy=false;
      b_schedule_output();
    }
  }

  private void b_schedule_output() {
    Cell icell=null;

    if(voport.link_busy) return;

    if(!voport.sigQueue.isEmpty()) {
      icell=(Cell)voport.sigQueue.remove(0);
    }
    else if(!voport.vbr.ptr.isEmpty()) {
      icell=(Cell)voport.vbr.ptr.remove(0);
      voport.vbr.iq.setValue(voport.vbr.ptr.size(),theSim.now(),b_log_factor.getValue());
    }
    else if(!voport.abr.ptr.isEmpty()) {
      icell=(Cell)voport.abr.ptr.remove(0);
      voport.abr.iq.setValue(voport.abr.ptr.size(),theSim.now(),b_log_factor.getValue());
    }

    if(icell!=null) {
      theSim.enqueue(new SimEvent(SimProvider.EV_RECEIVE,this,voport.to_link,theSim.now(),icell));
      voport.link_busy=true;
    }
  }

//helper function, check whether an NSAP is a local interface
  private boolean targetMe(String calledNSAP) {
    if(voport==null) return false;
    if(calledNSAP.equals(voport.nsap.getValue())) return true;
    return false;
  }

  private void b_receive_uni(SimEvent e) {
    UNIInfo uni=(UNIInfo)e.getParams();

    //note: this can only be received from Application!

    switch(uni.msgtype) {
      case UNIInfo.UNI_SETUP:
        //first, check whether it's a local call...
        if(targetMe(uni.calledNSAP)) {
          //don't allow that, so send release_complete
          UNIInfo newuni=new UNIInfo();
          newuni.callref=uni.callref+65535; //reverse direction must set "flag"...
          newuni.msgtype=UNIInfo.UNI_RELEASE_COMPLETE;
          theSim.enqueue(new SimEvent(SimProvider.EV_RECEIVE_UNI,this,
            e.getSource(),theSim.now(),newuni));
          return;
        }

        //else, add a new record
        CallRecord newrec=new CallRecord();
        newrec.key=null; //not assigned yet...
        newrec.appcomp=(SimComponent)e.getSource();
        newrec.callref=uni.callref; //this IS the app_port !
        newrec.contype=uni.contype;

        records.put(new Integer(newrec.callref),newrec);

        //must send out the only link...
        if(voport!=null) { //safety check
          voport.sigQueue.addAll(voport.aal.sendData(uni,120,0,5));
          b_schedule_output();
        }
        break;

      case UNIInfo.UNI_RELEASE:
        //got the RELEASE message, so delete the call record
        //right now, assume ALWAYS release by source...
        //(although the GenericATMSwitch allows release by any party, but...)
        CallRecord rec=(CallRecord)records.remove(new Integer(uni.callref));
        ftable.remove(rec.key);

        if(voport!=null) {//safety check
          voport.sigQueue.addAll(voport.aal.sendData(uni,20,0,5));
          b_schedule_output();
        }
        break;
    }
  }

  private void b_receive(SimEvent e) {
    Cell cell=(Cell)e.getParams();

    CallRecord rec;
    SimComponent src=(SimComponent)e.getSource();
    SimComponent dest;

  //update total received cell, including those from local applications
    b_cell_count++;
    b_cc.setValue(b_cell_count,theSim.now(),b_log_factor.getValue());

    if(src.getCompClass().equals("Application")) {
      //look up first...
      rec=(CallRecord)ftable.get(new CallRecordKey(cell.vpi,cell.vci));
      if(rec==null) return; //no record!! Can't be....

      if(voport!=null) {
        if(rec.contype==UNIInfo.CON_ABR || rec.contype==UNIInfo.CON_UBR) {
          if((voport.abr.ptr.size()<b_oqsize.getValue()) || (b_oqsize.getValue()==-1)) {
            voport.abr.ptr.add(cell);
            voport.abr.iq.setValue(voport.abr.ptr.size(),theSim.now(),b_log_factor.getValue());
            b_schedule_output();
          }
          else //drop it if queue full
            voport.abr.dq.setValue(voport.abr.dq.getValue()+1,theSim.now(),b_log_factor.getValue());
        }
        else {
          if((voport.vbr.ptr.size()<b_oqsize.getValue()) || (b_oqsize.getValue()==-1)) {
            voport.vbr.ptr.add(cell);
            voport.vbr.iq.setValue(voport.vbr.ptr.size(),theSim.now(),b_log_factor.getValue());
            b_schedule_output();
          }
          else //drop it if queue full
            voport.vbr.dq.setValue(voport.vbr.dq.getValue()+1,theSim.now(),b_log_factor.getValue());
        }
      }
    }
    else if(src.getCompClass().equals("Link")) {
      rec=(CallRecord)r_ftable.get(new CallRecordKey(cell.vpi,cell.vci));
      if(rec==null) { //no record...
        //check for signaling cells
        if(cell.vpi==0 && cell.vci==5) {
          if(voport.aal.receiveCell(cell)==1) {
            UNIInfo uni=(UNIInfo)cell.payload;

            switch(uni.msgtype) {
              case UNIInfo.UNI_SETUP:
                //call request from others
                dest=(SimComponent)app_ports.get(new Integer(uni.calledport));
                if(dest==null) { //oops, port doesn't exist...
                  //send RELEASE COMPLETE
                  UNIInfo newuni=new UNIInfo();
                  newuni.callref=uni.callref+65535; //reverse direction must set "flag"...
                  newuni.msgtype=UNIInfo.UNI_RELEASE_COMPLETE;
                  voport.sigQueue.addAll(voport.aal.sendData(newuni,20,0,5));
                  b_schedule_output();
                  return;
                }

                //should add record
                CallRecord newrec=new CallRecord();
                newrec.key=new CallRecordKey(uni.newvpi,uni.newvci);
                newrec.appcomp=dest;
                newrec.callref=uni.callref;
                newrec.contype=uni.contype;

                r_ftable.put(newrec.key,newrec);
                r_records.put(new Integer(newrec.callref),newrec);

                //and send back CONNECT (just accept all calls)
                UNIInfo newuni=new UNIInfo();
                newuni.callref=uni.callref+65535;
                newuni.msgtype=UNIInfo.UNI_CONNECT;
                voport.sigQueue.addAll(voport.aal.sendData(newuni,20,0,5));
                b_schedule_output();

                //pass through to the app
                theSim.enqueue(new SimEvent(SimProvider.EV_RECEIVE_UNI,this,dest,theSim.now(),uni));
                break;

              case UNIInfo.UNI_CALL_PROCEEDING:
                //call_proceeding for call setup from this bte,
                //now grab the vpi/vci
                rec=(CallRecord)records.get(new Integer(uni.callref-65535));
                rec.key=new CallRecordKey(uni.newvpi,uni.newvci);
                ftable.put(rec.key,rec);

                //pass through to the app
                theSim.enqueue(new SimEvent(SimProvider.EV_RECEIVE_UNI,this,rec.appcomp,theSim.now(),uni));
                break;

              case UNIInfo.UNI_RELEASE_COMPLETE:
                //must be call reject for call setup from this bte,
                //must delete the record
                rec=(CallRecord)records.get(new Integer(uni.callref-65535));
                ftable.remove(rec.key);
                records.remove(new Integer(rec.callref));

                //pass through to the app
                theSim.enqueue(new SimEvent(SimProvider.EV_RECEIVE_UNI,this,rec.appcomp,theSim.now(),uni));
                break;

              case UNIInfo.UNI_RELEASE:
                //release from others
                //(again, assume release ONLY from source...)
                //must delete the record
                rec=(CallRecord)r_records.get(new Integer(uni.callref));
                r_ftable.remove(rec.key);
                r_records.remove(new Integer(rec.callref));

                //pass through to the app
                theSim.enqueue(new SimEvent(SimProvider.EV_RECEIVE_UNI,this,rec.appcomp,theSim.now(),uni));
                break;

              case UNIInfo.UNI_CONNECT:
                //call accepted, just pass through to the app
                rec=(CallRecord)records.get(new Integer(uni.callref-65535));
                theSim.enqueue(new SimEvent(SimProvider.EV_RECEIVE_UNI,this,rec.appcomp,theSim.now(),uni));
                break;
            }
          }
        }
        //else, drop it (just ignore...)
        return;
      }

      theSim.enqueue(new SimEvent(SimProvider.EV_RECEIVE,this,rec.appcomp,theSim.now(),cell));
    }
  }
}