<!--

//[1] http://www.ripe.net/ripe/meetings/ripe-60/presentations/Aben-Measuring_IPv6_at_web_clients_and_caching_resolvers.pdf

// script heavily inspired by Sander Stefann's http://ipv6test.max.nl/
// kudos to Sander!
// Ajax code contributed by the fine folks at APNIC (Geoff Huston)
// This script will make a webbrowser do a limited number of queries to a test platform
// to assess IPv4 vs IPv6 preparedness of the webbrowser and the 
// caching resolver that the webbrowser is using
// comments/questions to: eaben@ripe.net

var __wdm_obj;

function WDM (site_id) {
 this.site_id = site_id;
 this.version='8';
 this.timeoutMsec=5000; // 5 sec
 this.no_check_interval=86400000; // 1 day
 this.timeout=false;
 this.domainSuffix='.wdm.sg.ripe.net';
 // r=rr's returned,t=transport, 4=ipv6, 6=ipv6, d=dual stack
 this.tests = ['rd.td','r4.t6','r6.t4','r4.t4'];
 // randomise
 fisher_yates_shuffle( this.tests );
 this.now = new Date();
 this.test_time=this.now.getTime()+(this.now.getTimezoneOffset()*60000);
 this.test_id=Math.floor(Math.random()*Math.pow(2,31));

 // cookie parsing
 this.cookie_last_run=undefined;

 var a_all_cookies=document.cookie.split(';');
 for(i=0;i<a_all_cookies.length;i++) {
   var a_temp_cookie=a_all_cookies[i].split('=');
   var cookie_name=a_temp_cookie[0].replace(/^\s+|\s+$/g,'');
   if(cookie_name=='wdm_last_run'){ 
     this.cookie_last_run = parseInt(unescape(a_temp_cookie[1].replace(/^\s+|\s+$/g,'')));
   }
 }
 __wdm_obj=this;
}


function fisher_yates_shuffle ( list ) {
 var i = list.length;
 if ( i == 0 ) return false;
 while ( --i ) {
    var j = Math.floor( Math.random() * ( i + 1 ) );
    var tmp_i = list[i];
    var tmp_j = list[j];
    list[i] = tmp_j;
    list[j] = tmp_i;
  }
}

WDM.prototype.setCookies=function(){
 // set last_run cookie
 var expire=new Date(this.now.getTime()+ this.no_check_interval );
 document.cookie='wdm_last_run='+this.now.getTime()+';expires='+expire.toGMTString()+';path=/';
}

WDM.prototype.run=function(forced){
 if(!forced && this.cookie_last_run ) { return };
 var oldonload=window.onload;
 var me=this;
 window.onload=function(){
   if(typeof oldonload=='function') oldonload();
   me.startTest();
 }
 this.setCookies(); // set regardless of fail or not
}

WDM.prototype.gih_ajax=function(URL){
   var req = null;

   try { req = new XMLHttpRequest(); } catch (e) { req = null; }
   if (!req) try { req = new ActiveXObject('Msxml2.XMLHTTP'); }
       catch (e) { req = null; }
   if (!req) try { req = new ActiveXObject('Microsoft.XMLHTTP'); }
       catch (e) { req = null; }

   try {
       req.open('GET', URL, true);
       req.send(null);
   } catch (e) {
       req = document.createElement('img');
       req.src = URL;
   }
   return req;
}


WDM.prototype.startTest=function(){
 var test_id = '__wdm_'+this.test_id;
 var prefix = 'u' +this.test_time + '.' + 
              's' + this.test_id + '.' + 
              'i' + this.site_id + '.' + 
              'v' + this.version;
 var infix = '/1x1.gif?'+prefix;
 // http://c1234.s1234.i1.v1.r4.t4.wdm.ripe.net?1x1.gif?c1234.s1234.i1.v1.r4.t4
 for(i=0;i<(this.tests.length);i++) {
   this.gih_ajax( "http://"+prefix+'.'+this.tests[i]+this.domainSuffix + infix + '.' + this.tests[i] );
 }
}

var wdm_test = new WDM(60);
wdm_test.run();

//-->