SEtherApp Class Reference

#include <SEtherApp.h>

Inheritance diagram for SEtherApp:

List of all members.

Protected Member Functions
virtual void	initialize (int stage)
virtual int	numInitStages () const
virtual void	handleMessage (cMessage *msg)
virtual void	finish ()
virtual void	choosePublication ()
virtual bool	genInformationItem ()
Protected Attributes
double	psProportion
	The proportion between publishing and subscribing (future use).

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Detailed Description

The Subscribe Ethernet Application class header The Subscribe Ethernet Application. This simple application acts more like a sink, apart from the fact that it is able to subscribe to Information Items existing or not in the Information Item Table of the simulation ground.

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Member Function Documentation

void SEtherApp::choosePublication

(

)

[protected, virtual]

Chooses a random publication from the Information Item Table, according to the popularity of each element. Afterwards, the application module tries to subscribe to this publication (although it might be already subscribed).

                                  {

        //Try to receive a published request for an Information Item
        InformationItem *publication=returnRandII();
        if(publication!=NULL) {

                //Inform the Global Information Item Table
                if(iit->addSubElement(publication,this->getParentModule())) {

                        ev << this->getParentModule()->getFullName() << ": Existing Information Item met with new subscription!" << endl;

                        subscriptionItem subitem;
                        subitem.ii=publication;
                        subscriptions.push_back(subitem);
                }
        }
        //If non returned for any reason print an error message
        else {
                ev << this->getParentModule()->getFullName() << ": Tried to find publication but list was empty!" << endl;
        }
}

void SEtherApp::finish

(

)

[protected, virtual]

The finish function of the application. Just calls the finish function of the base class.

Reimplemented from BasePSApp.

{
    BasePSApp::finish();
}

bool SEtherApp::genInformationItem

(

)

[protected, virtual]

It generates a information Item and places it into the subscriptions table of the subscriber, and informs the Information Item Table module, if exists.

                                   {
        //Create subscription item
        subscriptionItem subitem;

        /************Cancel afterwards!!!*************/
        //Generate random ID
        char ID[PURSUIT_ID_LEN+1];
        for(int i=0;i<PURSUIT_ID_LEN;i++)
        {
                        ID[i]=(char)(1+intrand(255));
        }
        //Put string end character
        ID[PURSUIT_ID_LEN] = '\0';

        InformationItem *II=new InformationItem("0457A0B220ABF100",ID);
        //InformationItem *II=new InformationItem("0457A0B220ABF100","BGA%£FD");

        //Assign the successfully created Information Item in the subscription
        subitem.ii=II;

        //Create randomly Meta-data for the future Information Item
        //TODO: Find a method for generating these metadata
        subitem.qos[QoS_BW_M]=(uint16_t)datarate->doubleValue();
        subitem.qos[QoS_FLOW]=1;

        /* First the Topology Manager has to be informed of the new Information Item
         * and it's meta data. This happens to avoid finding paths without being
         * informed of the QoS requirements of each item. If there is a mistake,
         * such as the Information Item already exists, the Topology Manager will
         * not accept the packet. The same information lies on the rendezvous table.*/
        publishMetaDataPacket(subitem);

        /***Inform the Global Information Item Table***/
        if(iit->addSubElement(II,this->getParentModule())) {
                //Add the successfully created Information Item
                subitem.ii=II;

                subscriptions.push_back(subitem);
                return true;
        }
        /**********************************************/

        return false;
}

void SEtherApp::handleMessage

(

cMessage *

msg

)

[protected, virtual]

Handles incoming messages for the subscriber application. It actually only records their statistics and deletes them.

Reimplemented from BasePSApp.

{
        if (msg->isSelfMessage())
        {
                //Self message to create or delete a new subscription
                if(strcmp(msg->getFullName(),"choosePublisher")==0) {
                        //Decide whether to make new subscription
                        double now=simTime().dbl();
                        //Get a random variable according the the Gaussian distribution
                        double subPeak=normal(this->par("actPeak").doubleValue(),PEAK_DEV);

                        //Try to create a new subscription, if the random variable is close enough to the current time.
                        //To create a periodical functionality, the modulo of the current time is taken for the time
                        //period equal to three times the mean value of the Gaussian random variable.
                        if(subPeak-(2*PEAK_DEV+1)<fmod(now,3*subPeak) && subPeak+(2*PEAK_DEV+1)>fmod(now,3*subPeak)) {
                                if(dblrand()<0.8) {
                                        choosePublication();
                                }
                                else {
                                        genInformationItem();
                                }
                        }
                        //Or delete an old one if the current time is close enough the the double of the Gaussian mean.
                        //Notice that a bit more space is given to the removing of subscriptions, since it creates
                        //better results.
                        else if(2*subPeak-(2*PEAK_DEV+2)<fmod(now,3*subPeak) && 2*subPeak+(2*PEAK_DEV+2)>fmod(now,3*subPeak)) {
                                cancelInformationItem(UNSUBSCRIBE_INFO);
                        }

                        simtime_t st = par("subInterval").doubleValue();
                        // Send packet with a small jitter
                        simtime_t jitter = dblrand() * MAXJITTER;
                        scheduleAt(simTime()+st+jitter, msg);
                }
        }
        else {
                EV << "Received packet `" << msg->getName() << "'\n";

                packetsReceived++;
                simtime_t lastEED = simTime() - msg->getCreationTime();
                eedVector.record(lastEED);
                eedStats.collect(lastEED);

                //Left here for future use
                PSEtherAppMsg *req = check_and_cast<PSEtherAppMsg *>(msg);
                Ieee802Ctrl *ctrl = check_and_cast<Ieee802Ctrl *>(req->removeControlInfo());
                //MACAddress srcAddr = ctrl->getSrc();

                delete ctrl;
                delete req;
        }
}

void SEtherApp::initialize

(

int

stage

)

[protected, virtual]

Initialization function of the subscriber application. Schedules the initial self messages and is able to create some initial subscriptions.

Reimplemented from BasePSApp.

{
        BasePSApp::initialize(stage);
        if(stage==1) {
                //Read the proportion of choosing publishers against adding subscribers
                psProportion = simulation.getSystemModule()->par("PubSubProportion");
                if(psProportion<0 || psProportion>1)
                        psProportion=0.5;

                //Generate self message for choosing a subscriber to publish for
                cMessage *choosePubmsg = new cMessage("choosePublisher");
                simtime_t st = par("subInterval").doubleValue();
                // Send packet with a small jitter
                simtime_t jitter = dblrand() * MAXJITTER;
                scheduleAt(simTime()+st+jitter, choosePubmsg);
        }
}

virtual int SEtherApp::numInitStages

(

)

const [inline, protected, virtual]

Returns the number of the initialization stages.

Reimplemented from BasePSApp.

{return 5;}

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Member Data Documentation

double SEtherApp::psProportion [protected]

The proportion between publishing and subscribing (future use).

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The documentation for this class was generated from the following files:

• SEtherApp.h
• SEtherApp.cc