vendor PriorityQueue.js

fetched from https://github.com/augustohp/Priority-Queue-NodeJS @ afae37d40

lib/riemann/dash/public/vendor/PriorityQueue.js

@@ -0,0 +1,158 @@
+/**
+ * Object to be appended in the priority queue.
+ *
+ * @class
+ * @param 	mixed 	v
+ * @param	integer	p
+ * @author	Augusto Pascutti
+ */
+var QueueItem = function(v, p) {
+	this.value    = v;
+	this.priority = p;
+};
+
+/**
+ * Priority queue class.
+ *
+ * @class
+ * @param 	Function[optional] 	c	Compare function to be used
+ * @param	integer[optional]	m	Max number of elements to hold
+ * @author	Augusto Pascutti
+ */
+var PriorityQueue = function(c, m) { this.init(c, m) };
+PriorityQueue.prototype = {
+	_queue: [],
+	_compare: undefined,
+	_size: 0,
+
+	/**
+	 * Priority queue class constructor.
+	 *
+	 * @class
+	 * @param 	Function[optional] 	compare_function	Compare function to be used
+	 * @param	integer[optional]	maximum_size		Max number of elements to hold
+	 */
+	init: function(compare_function, maximum_size) {
+		this._compare = compare_function || undefined;
+		this._size    = maximum_size || 0 ;
+		this.reset();
+	},
+
+	/**
+	 * Pushes something to the priority queue.
+	 *
+	 * @param 	mixed 		value
+	 * @param 	integer		priority
+	 * @return 	void
+	 */
+	push: function(value, priority) {
+		this._queue.push(new QueueItem(value, priority));
+		this._queue.sort(this.compare());
+		this._maitain();
+	},
+
+	/**
+	 * Removes the most important item and return its value. 
+	 *
+	 * @return mixed
+	 */
+	pop: function() {
+		item = this._queue.shift();
+		this._maitain();
+		return (item) ? item.value : undefined;
+	},
+
+	/**
+	 * Returns most important item value from this queue, without removing it.
+	 *
+	 * @return mixed
+	 */
+	top: function() {
+		item = this._queue[0];
+		return (item) ? item.value : undefined;
+	},
+
+	/**
+	 * Removes the less important item and return its value.
+	 *
+	 * @return mixed
+	 */
+	shift: function() {
+		item = this._queue.pop();
+		this._maitain();
+		return (item) ? item.value : undefined;
+	},
+
+	/**
+	 * Returns the less important item value, without removing it.
+	 *
+	 * @return mixed
+	 */
+	bottom: function() {
+		idx  = this.length-1;
+		item = this._queue[idx];
+		return (item) ? item.value : undefined;
+	},
+	
+	/**
+	 * Returns the ordered queue as an Array.
+	 *
+	 * @return Array
+	 */
+	getArray: function() {
+	    return this._queue || new Array();
+	},
+
+	/**
+	 * Resets the queue.
+	 *
+	 * @return void
+	 */
+	reset: function() {
+		this._queue = [];
+		this._maitain();
+	},
+
+	/**
+	 * Returns the compare function.
+	 * If no compare function is set, defines a default one.
+	 *
+	 * @return Function
+	 */
+	compare: function() {
+		if (!this._compare) {
+			this._compare = function(a,b) {
+				return b.priority - a.priority;
+			};
+		}
+		return this._compare;
+	},
+
+	/**
+	 * Defines a fixed size to the queue.
+	 * Zero for no limit and any other number to set it as the highest number
+	 * of items allowed in this queue.
+	 *
+	 * @param 	integer		i
+	 * @return 	void
+	 */
+	size: function(i) {
+		this._size = i;
+	},
+
+	/**
+	 * Keeps the size of the queue by removing the less important item of it and length
+	 * information atribute.
+     *
+	 * @return void
+	 */
+	_maitain: function() {
+	    this.length = this._queue.length;
+		if ( this._size == 0 ) return;
+		while (this._size < this.length) {
+			this.shift();
+		}
+	},
+};
+
+module.exports = PriorityQueue;

lib/riemann/dash/views/index.erubis

@@ -24,6 +24,7 @@
   <script src="vendor/flot/jquery.flot.canvas.min.js"></script>
   <script src="vendor/flot/jquery.flot.time.min.js"></script>
   <script src="vendor/flot/jquery.flot.stack.min.js"></script>
+  <script src="vendor/PriorityQueue.js"></script>
   <script> // turn underscore templates into mustache style templates
     _.templateSettings = {
       evaluate    : /\{\%([\s\S]+?)\%\}/g,  // {%  eval(js);  %}