JS Async setInterval

JS Async setInterval

function asyncInterval(){
	var self = this;

	self.interation = {};
	self.interationNumber = 0;
	self.asyncCompleteFlag = false;

	self.checkInterval = undefined;

	self.start = function(toRun, speed){//toRun must be passed asyncInterval, so it can set asyncCompleteFlag
		self.checkInterval = setInterval(function(){
			self.checkComplete(toRun, speed);
		}, 10);
	};

	self.end = function(){
		if(!!self.checkInterval){
			clearInterval(self.checkInterval);
		}

		self.checkInterval = undefined;
		self.asyncCompleteFlag = false;
	};

	self.done = function(){
		self.asyncCompleteFlag = true;
	};

	self.checkComplete = function(toRun, speed){
		if(!!self.interation[self.interationNumber]){//Currently waiting
			var interationStart = self.interation[self.interationNumber];
			var dif = Date.now() - interationStart;

			if(dif >= speed && self.asyncCompleteFlag){//Speed has been met, Async function has completed
				self.interationNumber = self.interationNumber + 1;
				self.asyncCompleteFlag = false;
			}
		} else{//Start new waiting
			self.interation[self.interationNumber] = Date.now();
			toRun(self);
		}
	};
}