Scala example source code file (scheduler.js)

This example Scala source code file (scheduler.js) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Scala tags/keywords

array, array, scheduler, scheduler, this, this

The Scala scheduler.js source code

// © 2010 EPFL/LAMP
// code by Gilles Dubochet

function Scheduler() {
    var scheduler = this;
    var resolution = 0;
    this.timeout = undefined;
    this.queues = new Array(0); // an array of work pacakges indexed by index in the labels table.
    this.labels = new Array(0); // an indexed array of labels indexed by priority. This should be short.
    this.label = function(name, priority) {
        this.name = name;
        this.priority = priority;
    }
    this.work = function(fn, self, args) {
        this.fn = fn;
        this.self = self;
        this.args = args;
    }
    this.addLabel = function(name, priority) {
        var idx = 0;
        while (idx < scheduler.queues.length && scheduler.labels[idx].priority <= priority) { idx = idx + 1; }
        scheduler.labels.splice(idx, 0, new scheduler.label(name, priority));
        scheduler.queues.splice(idx, 0, new Array(0));
    }
    this.clearLabel = function(name) {
        var idx = 0;
        while (idx < scheduler.queues.length && scheduler.labels[idx].name != name) { idx = idx + 1; }
        if (idx < scheduler.queues.length && scheduler.labels[i].name == name) {
            scheduler.labels.splice(idx, 1);
            scheduler.queues.splice(idx, 1);
        }
    }
    this.nextWork = function() {
        var fn = undefined;
        var idx = 0;
        while (idx < scheduler.queues.length && scheduler.queues[idx].length == 0) { idx = idx + 1; }
        if (idx < scheduler.queues.length && scheduler.queues[idx].length > 0) {
            var fn = scheduler.queues[idx].shift();
        }
        return fn;
    }
    this.add = function(labelName, fn, self, args) {
        var doWork = function() {
            scheduler.timeout = setTimeout(function() {
                var work = scheduler.nextWork();
                if (work != undefined) {
                    if (work.args == undefined) { work.args = new Array(0); }
                    work.fn.apply(work.self, work.args);
                    doWork();
                }
                else {
                    scheduler.timeout = undefined;
                }
            }, resolution);
        }
        var idx = 0;
        while (idx < scheduler.labels.length && scheduler.labels[idx].name != labelName) { idx = idx + 1; }
        if (idx < scheduler.queues.length && scheduler.labels[idx].name == labelName) {
            scheduler.queues[idx].push(new scheduler.work(fn, self, args));
            if (scheduler.timeout == undefined) doWork();
        }
        else throw("queue for add is non existant");
    }
    this.clear = function(labelName) {
        var idx = 0;
        while (idx < scheduler.labels.length && scheduler.labels[idx].name != labelName) { idx = idx + 1; }
        if (idx < scheduler.queues.length && scheduler.labels[idx].name == labelName) {
            scheduler.queues[idx] = new Array();
        }
    }
};