Mehr Speed durch parallele AJAX-Requests

<script type="text/javascript">
var request={
	channels:[],
	channelsize:5,
	querys:[],
	init:function(){
		for(var i=0;i<this.channelsize;i++)this.channels[i]=null;
	},
	/**
	 * send a XMLHttpRequest
	 *
	 * @param uri	The uri of the ressource.
	 * @param post	Post datafield.
	 * @param cb	Callbackfunction for the response.
	 */
	send:function(uri,post,cb){
		this.querys.push({'uri':uri,'post':post,'cb':cb});
		this._run();
	},
	_run:function(){
		if(this.querys.length==0)return;
		for(var i=0;i<this.channelsize;i++){
			if (this.channels[i]===null) {
				var job=this.querys.pop();
				this.channels[i] = new XMLHttpRequest();
				this.channels[i].callback=job.cb;
				this.channels[i].id=i;
				this.channels[i].open((job.post)?'POST':'GET', job.uri, true);
				if(job.post)this.channels[i].setRequestHeader('Content-type','application/x-www-form-urlencoded;Charset=utf-8');
				this.channels[i].onreadystatechange=function(){
					if(this.readyState==4){
						if (this.status==200)eval(this.callback+'(this.responseText)');
						request._clearChannel(this.id);
					}
				}
				this.channels[i].send(job.post);
				break;
			}
		}
	},
	_clearChannel:function(id){this.channels[id]=null;this._run()}
}
request.init();
</script>

<script type="text/javascript">
// mit Post Daten
request.send('example.php','foo=bar&bar=foo','callback');
 
// mit Get Daten
request.send('example.php?foo=bar&bar=foo',null,'callback');
 
// oder beides
request.send('example.php?get=foo', 'post=bar','callback');
</script>

<script type="text/javascript">
function callback(responseText) {
	// Reponse verarbeiten
}
</script>

<script type="text/javascript">
var sendRequest=(function(){
    var channels    = [],
        channelsize = 5,
        querys      = [],
        i;
 
    // init
    for (i = 0; i < channelsize; i += 1) {
        channels[i] = null;
    }
 
    var run = function() {
        // Inhalt zu ergängen
    };
 
    var clearChannel = function(id) {
        // Inhalt zu ergänzen
    };
 
    /**
    * send a XMLHttpRequest
    *
    * @param uri	The uri of the ressource.
    * @param post	Post datafield.
    * @param cb	Callbackfunction for the response.
    */
    var send = function(uri,post,cb){
        querys.push({'uri':uri,'post':post,'cb':cb});
        run();
    };
    return send;
})();
 
 
// Aufruf
sendRequest('exampe.php', 'foo=bar&bar=foo', callback);
</script>