lcars-library-node/library/util/random.js

NodeJS module for creating a library for the LCARS dashboard system

/**
 * Provides static references to randomization functions.
 * @class Random
 * @constructor
 * @static
 */
var configuration = require("a-configuration");

/**
 * Quick reference array for generating random strings
 * @private
 * @property alphanumeric
 * @type Array
 */
var alphanumeric = ["0","1","2","3","4","5","6","7","8","9","A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z","a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"];

/**
 * Return a floating point number.
 * @method float
 * @param {Number} range The range/spread in which the returned number
 * 		should originate.
 * @param {Number} [min] The minimum starting value to offset the returned
 * 		number specified by the range. If omitted, the returned number is
 * 		between 0 and this value.
 * @return {Number} A number from within the specified range.
 */
this.float = function(range, min) {
	if(min) {
		return Math.random() * range + min;
	}
	return Math.random() * range;
};

/**
 * Return an integer point number.
 * @method int
 * @param {Number} range The range/spread in which the returned numbenr
 * 		should originate.
 * @param {Number} [min] The minimum starting value to offset the returned
 * 		number specified by the range. If omitted, the returned number is
 * 		between 0 and this value.
 * @return {Integer} A number from within the specified range.
 */
this.int = function(range, min) {
	if(min) {
		return Math.floor(Math.random() * range) + min;
	}
	return Math.floor(Math.random() * range);
};

/**
 * Return a String of the specified length.
 * @method string
 * @param {Number} len The length of the String to return.
 * @return {String} A string with the specified length.
 */
this.string = function(len) {
	if(len) {
		var string = alphanumeric[this.int(alphanumeric.length)];
		while(string.length < len) {
			string += alphanumeric[this.int(alphanumeric.length)];
		}
		return string;
	} else {
		return null;
	}
};

/**
 * Return an identifier for Terminals.
 * @method terminalID
 * @param {Number} [now] Timestamp for marking the ID strictly for uniqueness. Defaults to Date.now().
 * @return {String} A string for identifying a terminal. 
 */
this.terminalID = function(now) {
	return "terminal:" + (now || Date.now()) + ":" + this.string(19);
};

/**
 * Return an identifier for Sessions.
 * @method sessionID
 * @param {Number} [now] Timestamp for marking the ID strictly for uniqueness. Defaults to Date.now().
 * @return {String} A string for identifying a session. 
 */
this.sessionID = function(now) {
	return "session:" + (now || Date.now()) + ":" + this.string(51);
};

/**
 * Return an identifier for Exceptions.
 * @method exceptionID
 * @param {Number} [now] Timestamp for marking the ID strictly for uniqueness. Defaults to Date.now().
 * @return {String} A string for identifying a exception. 
 */
this.exceptionID = function(now) {
	return "exception:" + (now || Date.now()) + ":" + this.string(19);
};

/**
 * Return an identifier for Events.
 * @method eventID
 * @param {Number} [now] Timestamp for marking the ID strictly for uniqueness. Defaults to Date.now().
 * @return {String} A string for identifying an event. 
 */
this.eventID = function(now) {
	return "event:" + (now || Date.now()) + ":" + this.string(19);
};

/**
 * Return an identifier for Events.
 * @method elementID
 * @param {Number} [now] Timestamp for marking the ID strictly for uniqueness. Defaults to Date.now().
 * @return {String} A string for identifying an element. 
 */
this.elementID = function(now) {
	return "element:" + (now || Date.now()) + ":" + this.string(19);
};

/**
 * Return an identifier for Events.
 * @method edgeID
 * @param {Number} [now] Timestamp for marking the ID strictly for uniqueness. Defaults to Date.now().
 * @return {String} A string for identifying an edge. 
 */
this.edgeID = function(now) {
	return "edge:" + (now || Date.now()) + ":" + this.string(19);
};

/**
 * Return an identifier for Sets.
 * @method setID
 * @param {Number} [now] Timestamp for marking the ID strictly for uniqueness. Defaults to Date.now().
 * @return {String} A string for identifying a set. 
 */
this.setID = function(now) {
	return "set:" + (now || Date.now()) + ":" + this.string(19);
};