Timer Objects for Network Latency

The heart of the Timer class.

I left out a simple tip from my "Tricks I Learned At Apple: Steve Jobs Load Testing" piece about timer objects. Below, is a complete, yet simple, Timer object class I wrote shortly after leaving Apple when I was working with SMS Hayes AT commands and RESTful APIs.

Exponential Notification

Timer objects do nothing more than measure the time it takes for a server's request/response loop to complete. Since this type of call is made over a network, it might finish very quickly (as expected) or, if the network is down or congested, it could take along time. If it takes a long time, the system admins will want to know. A good notification method is not to send an e-mail update or text message every single minute, or so – that ends up flooding people's inboxes. Instead, an exponential notification would be a much better idea. For example, notify the system administrators immediately, then wait one minute before the next notification, then wait two minutes, four minutes, eight minutes, etc. Finally, send a last notification once the issue's fixed.

Initiating the timer is simple...

Timer timer = Timer.startNewTimer();

NSLog.debug.appendln("Start time = " + timer.startTime());

Response response = saleTransaction.submitTransaction();

timer.stop();

NSLog.debug.appendln("Stop time = " + timer.stopTime());

And, lastly, the complete Java timer class is anticlimactic.

package com.woextras;

import com.webobjects.foundation.NSTimestamp;

public class Timer

{

private NSTimestamp _startTime = null;

private NSTimestamp _stopTime = null;

public static Timer startNewTimer()

{

Timer timer = new Timer();

timer.start();

return timer;

}

public void start()

{

_startTime = new NSTimestamp();

}

public void stop()

{

_stopTime = new NSTimestamp();

}

public NSTimestamp startTime()

{

return _startTime;

}

public NSTimestamp stopTime()

{

return _stopTime;

}

public Long elapsedTime()

{

long completionTime = -1;

if (_startTime != null)

{

long startTime = _startTime.getTime();

long stopTime;

if (_stopTime != null)

{

stopTime = _stopTime.getTime();

} else

{

stopTime = new NSTimestamp().getTime();

}

completionTime = (stopTime - startTime) / 1000L;

}

return completionTime;

}

}