A cDatarateChannel extended with throughput calculation. More...

#include <ThruputMeteringChannel.h>

Inheritance diagram for inet::ThruputMeteringChannel:

Public Member Functions
	ThruputMeteringChannel (const char *name=nullptr)
	Constructor. More...

virtual	~ThruputMeteringChannel ()
	Copy constructor. More...

virtual void	initialize () override
	Assignment. More...

virtual void	processMessage (cMessage *msg, simtime_t t, result_t &result) override
	Adds statistics and live display to the channel. More...

Protected Member Functions
virtual void	beginNewInterval (simtime_t now)

virtual void	refreshDisplay () const override

Protected Attributes
const char *	fmt

unsigned int	batchSize

simtime_t	maxInterval

long	numPackets

double	numBits

simtime_t	intvlStartTime

simtime_t	intvlLastPkTime

unsigned long	intvlNumPackets

unsigned long	intvlNumBits

double	currentBitPerSec

double	currentPkPerSec

Detailed Description

A cDatarateChannel extended with throughput calculation.

Values get displayed on the link, using the connection's "t=" display string tag.

The display can be customized with the "format" attribute. In the format string, the following characters will get expanded:

'N': number of packets
'V': volume (in bytes)
'p': current packet/sec
'b': current bandwidth
'u': current channel utilization (%)
'P': average packet/sec on [0,now)
'B': average bandwidth on [0,now)
'U': average channel utilization (%) on [0,now) Other characters are copied verbatim.

"Current" actually means the last measurement interval, which is 10 packets or 0.1s, whichever comes first.

PROBLEM: display only gets updated if there's traffic! (For example, a high pk/sec value might stay displayed even when the link becomes idle!)

Constructor & Destructor Documentation

inet::ThruputMeteringChannel::ThruputMeteringChannel ( const char * name = nullptr )

explicit

Constructor.

                                                                : cDatarateChannel(name)
 {
     fmt = nullptr;
     batchSize = 10;    // packets
     maxInterval = 0.1;    // seconds
 
     numPackets = 0;
     numBits = 0;
 
     intvlStartTime = intvlLastPkTime = 0;
     intvlNumPackets = intvlNumBits = 0;
 
     currentBitPerSec = currentPkPerSec = 0;
 }

inet::ThruputMeteringChannel::~ThruputMeteringChannel ( )

virtual

Copy constructor.

Destructor.

40 {

41 }

Member Function Documentation

void inet::ThruputMeteringChannel::beginNewInterval ( simtime_t now )

protectedvirtual

Referenced by processMessage().

 {
     simtime_t duration = now - intvlStartTime;
 
     // record measurements
     currentBitPerSec = intvlNumBits / duration;
     currentPkPerSec = intvlNumPackets / duration;
 
     // restart counters
     intvlStartTime = now;
     intvlNumPackets = intvlNumBits = 0;
 }

void inet::ThruputMeteringChannel::initialize ( )

overridevirtual

Assignment.

Creates and returns an exact copy of this object. See cObject for more details. Add parameters and initialize the stat variables

 {
     cDatarateChannel::initialize();
     fmt = par("thruputDisplayFormat");
 }

void inet::ThruputMeteringChannel::processMessage	(	cMessage *	msg,
		simtime_t	t,
		result_t &	result
	)

overridevirtual

Adds statistics and live display to the channel.

 {
     cDatarateChannel::processMessage(msg, t, result);
 
     cPacket *pkt = dynamic_cast<cPacket *>(msg);
     // TODO handle disabled state (show with different style?/color? or print "disabled"?)
     if (!pkt || !fmt || *fmt == 0 || result.discard)
         return;
 
     // count packets and bits
     numPackets++;
     numBits += pkt->getBitLength();
 
     // packet should be counted to new interval
     if (intvlNumPackets >= batchSize || t - intvlStartTime >= maxInterval)
         beginNewInterval(t);
 
     intvlNumPackets++;
     intvlNumBits += pkt->getBitLength();
     intvlLastPkTime = t;
 }

void inet::ThruputMeteringChannel::refreshDisplay ( ) const

overrideprotectedvirtual

 {
     // produce label, based on format string
     char buf[200];
     char *p = buf;
     simtime_t tt = getTransmissionFinishTime();
     if (tt == 0)
         tt = simTime();
     double bps = (tt == 0) ? 0 : numBits / tt;
     double bytes;
     for (const char *fp = fmt; *fp && buf + 200 - p > 20; fp++) {
         switch (*fp) {
             case 'N':    // number of packets
                 p += sprintf(p, "%ld", numPackets);
                 break;
 
             case 'V':    // volume (in bytes)
                 bytes = floor(numBits / 8);
                 if (bytes < 1024)
                     p += sprintf(p, "%gB", bytes);
                 else if (bytes < 1024 * 1024)
                     p += sprintf(p, "%.3gKiB", bytes / 1024);
                 else
                     p += sprintf(p, "%.3gMiB", bytes / 1024 / 1024);
                 break;
 
             case 'p':    // current packet/sec
                 p += sprintf(p, "%.3gpps", currentPkPerSec);
                 break;
 
             case 'b':    // current bandwidth
                 if (currentBitPerSec < 1000000)
                     p += sprintf(p, "%.3gk", currentBitPerSec / 1000);
                 else
                     p += sprintf(p, "%.3gM", currentBitPerSec / 1000000);
                 break;
 
             case 'u':    // current channel utilization (%)
                 if (getDatarate() == 0)
                     p += sprintf(p, "n/a");
                 else
                     p += sprintf(p, "%.3g%%", currentBitPerSec / getDatarate() * 100.0);
                 break;
 
             case 'P':    // average packet/sec on [0,now)
                 p += sprintf(p, "%.3gpps", tt == 0 ? 0 : numPackets / tt);
                 break;
 
             case 'B':    // average bandwidth on [0,now)
                 if (bps < 1000000)
                     p += sprintf(p, "%.3gk", bps / 1000);
                 else
                     p += sprintf(p, "%.3gM", bps / 1000000);
                 break;
 
             case 'U':    // average channel utilization (%) on [0,now)
                 if (getDatarate() == 0)
                     p += sprintf(p, "n/a");
                 else
                     p += sprintf(p, "%.3g%%", bps / getDatarate() * 100.0);
                 break;
 
             default:
                 *p++ = *fp;
                 break;
         }
     }
     *p = '\0';
 
     // display label
     getSourceGate()->getDisplayString().setTagArg("t", 0, buf);
 }