EDIT

function CacheBot(searchTaxaUrl, taxonPageUrl, pageSize, progressCallback, readyCallback, doneCallback, errorCallback){

	var taxonPageUrl = taxonPageUrl;

	var searchTaxaUrl = searchTaxaUrl;

	var pageSize;

	var progress = 0;

	var i = 0;

	var doRun = false;

	var dataPager = null;

//	this.elapsedMillies = 0;

//	this.estimatedMillies = 0;

	/**

	 * Log to the Firebug Console if Firebug is available

	 * @param msg the massage to show in the firebug Console

	 * @return

	 */

	var log = function(msg){

		if (window.console && window.console.firebug){

			console.log(msg);

		}

	}

	/**

	 *

	 * @param data

	 * @param statusText

	 * @return

	 */

	var init = function(data, statusText){

	 	dataPager = data;

	 	if(dataPager != undefined){

	 		progressCallback(progress, null, null, "Ready!");

	 	}

	 	if(readyCallback != undefined){

	 		readyCallback();

	 	}

	 	elapsedMillies = 0;

	 	estimatedMillies = 0;

	};

	/**

	 *

	 * @param callback

	 * @return

	 */

	var requestNextDataPage = function(callback){

		var uri = searchTaxaUrl + escape("&pageSize=" + pageSize);

		if(dataPager != null){

			uri += escape("&page="+ dataPager.nextIndex);

		}

		log('page->'+uri);

		$.ajax({

			url: uri,

			dataType: 'json',

			cache: false, // browser will not cache

			success: callback,

			error: function(XMLHttpRequest, statusText ){

					stop();

					errorCallback(statusText, 'A network error occurred, please start again.', unescape(uri), true);

				}

		});

	}

	/**

	 *

	 */

	this.run = function(lastMillies){

		 //

		var now = new Date();

		var nowMillies = now.getTime();

		if(lastMillies != undefined){

			elapsedMillies += (nowMillies - lastMillies);

			estimatedMillies = (elapsedMillies / i) * dataPager.count;

		}

		var parent = this;

		// get next page of data

		if( i > dataPager.lastRecord - 1 && i < dataPager.count && dataPager.nextIndex != undefined){

			requestNextDataPage(function(data, statusText){

				if(statusText == 'success'){

					dataPager = data;

					parent.run(nowMillies);

				} else {

					parent.stop();

					readyCallback(statusText);

				}

			});

		} else {

			// update the progress callback

			var p = (i / dataPager.count);

			if(p != progress){

				progress = p;

				progressCallback(progress, new Date(elapsedMillies), new Date(estimatedMillies));

			}

			// get new taxon page

			if (doRun == true && i++ < dataPager.count){

				var ri = i - (dataPager.firstRecord);

				var taxon = dataPager.records[ri];

				var taxonUrl = taxonPageUrl + taxon.uuid + '/all';

				log('taxon->'+taxonUrl);

				$.ajax({

					url: taxonUrl,

					cache: false, // browser will not cache

					complete: function(xmlHttpRequest, statusText){

							if(xmlHttpRequest.status != 200){

								errorCallback(statusText, null, unescape(taxonUrl), false);

							}

							parent.run(nowMillies);

						}

				});

				taxon = null;

			} else if(i == dataPager.count) {

				// DONE!

				if(doneCallback != undefined){

					doneCallback();

			 	}

			} else if(doRun == false){

				readyCallback();

			}

		}

	};

	/**

	 *

	 */

	this.start =  function(){

			doRun = true;

			this.run();

		};

	/**

	 *

	 */

    this.stop = function(){

			doRun = false;

		};

	// get list of taxa and initialize the Bot

	progressCallback(0, null, null, "Initializing, please wait ...");

	requestNextDataPage(function(data, statusText){

		init(data, statusText);

	});

}

// -----------------------------------------------------------------------------

$(document).ready(function() {

	var searchTaxaUrl = $('#cdm-settings-cache [name=searchTaxaUrl]').val();

	var taxonPageUrl = $('#cdm-settings-cache [name=taxonPageUrl]').val();

	$('#cdm-settings-cache [name=start]').attr('disabled', 'disabled');

	$('#cdm-settings-cache [name=stop]').attr('disabled', 'disabled');

	$('#cdm-settings-cache #progress').css({background: '#012456', color: '#349AAF', fontSize: '100%', padding: '10px'})

    $('#cdm-settings-cache #progress').html(

    		'<div id="usermessage" style="font-size:95%; width: 50%; float:right; font-weight:light; padding:10px; border-left: 1px solid; height: 3.9em;"></div>'

    		+'<div id="counter" style="font-size:300%; padding:10px;"></div>'

    		+'<div id="time" style="clear:both; border-top:1px solid #349AAF;"></div>'

    		+'<div id="log" style="border-top:1px solid #349AAF; font-size:85%; overflow: auto; white-space:nowrap;"></div>');

	var formatTime = function(date){

		var h = parseInt(date.getTime() / 1000 / 60 / 60);

		var m = parseInt( (date.getTime() / 1000/ 60) % 60);

		var s = parseInt( (date.getTime() / 1000 ) % 60);

		return '' + h +'h '+ m +'m '+ s +'s ';

	}

	var progressCallback = function(progress, elapsedTime, estimatedTime, userMessage){

		var percent = Math.floor(progress * 10000) / 100;

		$('#counter').text(percent + '%');

		if(elapsedTime != null){

			var timehtml =

				'elapsed time: ' + formatTime(elapsedTime)

				+ '<br />estimated time: ' + formatTime(estimatedTime)

				+ '<br />remainig time: ' + formatTime(new Date(estimatedTime.getTime() - elapsedTime.getTime()));

			$('#time').html(timehtml);

		}

		if(userMessage == undefined || userMessage == null ){

			userMessage = '';

		}

		$('#usermessage').html(userMessage);

	}

	var readyCallback = function(message){

		$('#cdm-settings-cache [name=start]').removeAttr('disabled');

		if(message != undefined){

			$('#cdm-settings-cache').append('<div class="error">'+message+'</div>');

		}

	}

	var doneCallback = function(progress){

		var percent = Math.floor(progress * 10000) / 100;

		$('#cdm-settings-cache #progress').text('DONE');

		$('#cdm-settings-cache [name=stop]').removeAttr('disabled');

	}

	var errorCallback = function(errorMessage, userMessage, taxonUrl, doStop){

		var logentry = '<div>' + errorMessage + ' : ' + taxonUrl + '' + '</div>';

		if($('#log div').length == 0){

			$('#log').html(logentry);

		} else {

			$('#log div:last').append(logentry)

		}

		if(userMessage == undefined || userMessage == null ){

			userMessage = '';

		}

		$('#usermessage').html(userMessage);

		if(doStop){

			$('#cdm-settings-cache [name=stop]').attr('disabled', 'disabled');

			$('#cdm-settings-cache [name=start]').removeAttr('disabled');

		}

	}

	var cacheBot = new CacheBot(searchTaxaUrl, taxonPageUrl, 25, progressCallback, readyCallback, doneCallback, errorCallback);

	$('#cdm-settings-cache [name=start]').click(function(){

		cacheBot.start();

		$('#cdm-settings-cache [name=start]').attr('disabled', 'disabled');

		$('#cdm-settings-cache [name=stop]').removeAttr('disabled');

		$('#usermessage').html(' ');

	}).attr('disabled', 'disabled');

	$('#cdm-settings-cache [name=stop]').click(function(){

		cacheBot.stop();

		$('#cdm-settings-cache [name=stop]').attr('disabled', 'disabled');

	}).attr('disabled', 'disabled');

});