data queue communication engine

uses Queue() class and file I/O
for multi-user gaming & chat

exec/load/qengine.js

+/*
+	JAVASCRIPT MULTI-USER ENGINE -- BY MCMLXXIX (Matt Johnson) 05/2008
+	USING  FILE I/O FOR USER PRESENCE DETECTION & NAMED QUEUES FOR REAL-TIME MULTIPLAYER DATA
+*/
+
+load("sbbsdefs.js");
+load("logging.js");
+load("funclib.js");
+
+var QueueEngineLog;
+
+function DataQueue(root,name,log_)
+{
+	QueueEngineLog=(log_?log_:new Logger(root,name));
+
+	this.root=root;
+	this.name=name;
+	this.users=[];
+	this.notices=[];
+	this.stream=	new Queue(this.name + "_" + user.number);
+	this.user_file=	new File(this.root + user.number + ".usr");
+	
+	this.ReceiveData=function(ident)
+	{
+		this.UpdateUsers();
+		var data=[];
+		if(this.stream.poll(ident)) {
+			while(this.stream.poll(ident)) 
+			{
+				var incoming_data=this.stream.read(ident);
+				Log("received data from user: " + system.username(incoming_data.user));
+				data.push=incoming_data;
+			}
+		}
+		return data;
+	}
+	this.SendData=function(data,ident)
+	{
+		for(user_ in this.users) 
+		{
+			this.UpdateUsers();
+			this.users[user_].Send(data,ident);
+			Log("sending data to user: " + this.users[user_].user);
+		}
+	}
+	this.UpdateUsers=function()
+	{
+		var user_list=directory(this.root + "*.usr");
+		for(user_ in user_list)
+		{
+			var user_file=user_list[user_];
+			var user_file_name=file_getname(user_file);
+			var user_number=user_file_name.substring(0,user_file_name.indexOf("."));
+			if(!this.users[user_number] && user_number!=user.number) 
+			{
+				var user_queue=this.name+"_"+user_number;
+				this.users[user_number]=new QueueUser(user_number,user_file,user_queue);
+				this.notices.push(system.username(user_number) + " is here.");
+				Log("loaded new user: " + system.username(user_number));
+			}
+		}
+		for(user_ in this.users) 
+		{
+			if(!file_exists(this.users[user_].file))
+			{
+				delete this.users[user_];
+				this.notices.push(system.username(user_) + " has left.");
+				Log("removing absent user: " + system.username(user_));
+			}
+		}
+	}
+	this.Init=function(data)
+	{
+		this.UpdateUsers();
+		this.user_file.open('w+');
+		if(data) this.user_file.writeAll(data);
+		this.user_file.close();
+	}
+	function Log(text)
+	{
+		QueueEngineLog.Log(text);
+	}
+	this.Init();
+}
+function QueueUser(user_number,user_file,user_queue)
+{
+	this.user=user_number;
+	this.file=user_file;
+	this.queue=new Queue(user_queue);
+	this.Send=function(data,ident)
+	{
+		this.queue.write(data,ident);
+	}
+}