added queue for loading and offline storage of parsed info

fpjs/render/queue.js

@@ -0,0 +1,167 @@
+FP.Queue = function(worker, concurrency){
+	this._q = [];
+	this._tasks = {};
+	this.idCount = 0;
+	this.concurrency = 0;
+
+	this.workers = [];
+	this.available = [];
+	
+	if(typeof(worker) === "string") {
+		this.workerStr = worker;
+		this.addWorkers(concurrency || 1);
+	}
+	
+	if(typeof(worker) === "function") {
+		this.workerFunction = worker;
+		this.addFakeWorkers(concurrency || 1);
+	}
+	
+}
+
+FP.Queue.prototype.addWorkers = function(concurrency){
+	var min = this.concurrency,
+		max = min + concurrency;
+		
+	//-- Stop running jobs or something?
+	
+	for(var i=min; i < concurrency; i++){
+		var worker = new Worker(this.workerStr);
+		this.workers.push(worker); //-- Add new work
+		this.available.push(i);	//-- Make available to start tasks
+	}
+	
+	this.concurrency = concurrency;
+
+}
+
+FP.Queue.prototype.addFakeWorkers = function(concurrency){
+	var min = this.concurrency,
+		max = min + concurrency;
+
+	//-- Stop running jobs or something?
+
+	for(var i=min; i < concurrency; i++){
+		var worker = new FP.FakeWorker(this.workerFunction);
+		this.workers.push(worker); //-- Add new work
+		this.available.push(i);	//-- Make available to start tasks
+	}
+	
+	this.concurrency = concurrency;
+}
+
+FP.Queue.prototype.add = function(msg, callback, priority){
+	var ID = this.idCount;
+	//-- Add to task object : maybe check for dups
+	this._tasks[ID] = {
+		"msg": msg,
+		"callback": callback || function(){}
+	}
+	
+	//-- Add id to queue
+	if(!priority){
+		this._q.push(ID);
+	}else{
+		this._q.unshift(ID);
+		if(!this.running) this.run();
+	}
+	
+	//-- Increment ID for next task
+	this.idCount++;
+	
+	
+	
+	return ID;
+}
+
+FP.Queue.prototype.addGroup = function(group, callback){
+	var that = this,
+		counter = group.length,
+		after = function(){
+			counter--;
+			if(counter <= 0) callback();
+		};
+		
+	group.forEach(function(msg){
+		that.add(msg, after);
+	});
+
+	if(!this.running) this.run();
+	
+	return after;
+}
+
+FP.Queue.prototype.run = function(id){
+	if(this.running) return;
+	this.running = true;
+
+	while(this.available.length) {
+	  var next = this.next();
+	  if(!next) break; //-- no tasks left or error
+	}
+	
+}
+
+FP.Queue.prototype.find = function(msg){
+	
+}
+
+FP.Queue.prototype.next = function(){
+	var that = this,
+		curr = this._q.shift(),
+		task, 
+		workerID, 
+		worker;
+
+	if(typeof(curr) === "undefined"){
+		//-- Nothing left on queue
+		this.running = false;
+		return false; 
+	}
+	
+	task = this._tasks[curr];
+	workerID = this.available.pop();
+	worker = this.workers[workerID];
+	
+	//-- give worker new task
+	worker.postMessage(task.msg);
+	
+	//-- listen for worker response
+	worker.onmessage = function(e){
+		var data = e.data;
+
+		task.callback(data);
+		delete that._tasks[curr]; //-- Remove task
+		
+		that.available.push(workerID);
+		that.next();
+	}
+	
+	return worker;
+}
+
+FP.Queue.prototype.empty = function(){
+	this._q = [];
+	this._tasks = {};
+	//-- TODO: close workers
+}
+
+//-- A super simplistic fake worker, is passed a function instead of a script
+
+FP.FakeWorker = function(func){
+	this.func = func;
+}
+
+FP.FakeWorker.prototype.postMessage = function(msg){
+	setTimeout(function(){
+		this.func(msg, this.onmessage);
+	}.bind(this), 1);
+}
+
+FP.FakeWorker.prototype.onmessage = function(e){
+
+}
+
+FP.FakeWorker.prototype.close = function(e){
+
+}