co-work

The tinest work library for JavaScript ever.

Getting Started

On the server

Install the module with: npm install co-work

var worker = require('co-work');
worker.work(slots, routines, argsArray); 

In the browser

Download the production version or the development version.

In your web page:

<script src="dist/co-work.min.js"></script>
<script>
work(slots, routines, argsArray, callback);
</script>

In your code, you can attach co-work's methods to any object.

<script>
var exports = MyPackage.utils;
</script>
<script src="dist/co-work.min.js"></script>
<script>
MyPackage.utils.work(slots, routines, argsArray, callback);
</script>

Examples

The example bellow will execute the function asyncJob for argsArray.length times. Each time with a position from the argsArray. In this case, the work function guarantees that no more than three routines are executed concurrently.

var worker = require('co-work.js'),
    Q = require('q'),
    argsArray = ['foo','bar','baz','qux','quux','garply','waldo',
                    'fred','plugh','xyzzy','thud'],
    asyncRoutine = function(param1) {
            
        var deferred = Q.defer(), promise = deferred.promise;
    
        setTimeout(function() {
            console.log(param1 + ': This command is running asynchronously');
            deferred.resolve(param1);
        }, 1);
    
        // required to return a promise
        return promise;
    }
    callback = function() {
        console.log("Callback at the end");
    };

// Run no more than three concurrently
worker.work(3, asyncRoutine, argsArray, callback);

This is specially useful for routines like, reading many files asynchronously, in order to avoid EMFILE, too many open files 1 or EMFILE, too many open files 2 os example.

Deferred! return a promise object

Always remember to return a promise object from your async function. In order to kwnow when your routine is done, Co-Work will require you return a promise object like Q's promise, jQuery.Deferred()'s promise, or another one that implements this pattern.

API

worker.work(slots, routines[, argsArray|callback]) // Alias: batch
worker.work(slots, routines, argsArray[, callback]) // Alias: batch

    slots: (number) 
        Number of maximum jobs you want to execute concurrently;
    
    routines: (function|Array<function>) 
        function: The job you want to execute repeatedly . If you pass a function as routines parameter, this function will be executed for argsArray.length times
        Array<function>: The jobs you want to execute. If you pass an Array<function> as routines parameter, these functions will all be executed concurrently, restricted, obviously, by slots;
    
    argsArray: (Array) (optional)
        Array that contains the parameters to be iterated;
    
    callback: (function) (optional)
        Callback function called after all jobs execution

Contributing

In lieu of a formal styleguide, take care to maintain the existing coding style. Add unit tests for any new or changed functionality. Lint and test your code using Grunt.

Also, please don't edit files in the "dist" subdirectory as they are generated via Grunt. You'll find source code in the "lib" subdirectory!

Release History

• 0.4.0 Callback optional parameter
• 0.2.0 Args array parameter API fix release
• 0.1.4 Initial release

License

Copyright (c) 2015 Thiago Andrade
Licensed under the MIT license.