JS: Global Pub Sub

global.js

var global = {

	// pub sub lifted from http://jsperf.com/pub-sub-implementations/13
	cache: {},

	publish: function(topic, args) {
		var self = this;
		if (self.cache[topic]) {
			var currentCache = self.cache[topic],
				currentArgs = args || [];

			// make sure currentAgs is an array
			if (!$.isArray(currentArgs)) currentArgs = $.makeArray(currentArgs);

			for (var i = 0, j = currentCache.length; i < j; i++) {
				var callback = currentCache[i][0],
					context = currentCache[i][1];
				callback.apply(context, currentArgs);
			}
		}
	},

	subscribe: function(topic, callback, context) {
		var self = this;
		context = context || $;
		if (!self.cache[topic]) {
			self.cache[topic] = [];
		}
		self.cache[topic].push([callback, context]);
		return [topic, callback, context];
	},

	unsubscribe: function(handle) {
		var self = this;
		var topic = handle[0];
		if (self.cache[topic]) {
			var currentCache = self.cache[topic];
			for (var i = 0, j = currentCache.length; i < j; i++) {
				if (currentCache[i] === handle[1]) {
					currentCache.splice(i, 1);
				}
			}
		}
	}
};