asa-git/forked-worker-pool

/**
 * Provides a simple implementation for forked workers.
 */

//TODO: allow streams of data (thus bigger set of data)to be piped to and from the pool.
 
var EventEmitter = require('events').EventEmitter;
var util = require('util');

/**
 * Constructor of a Forked Worker.
 */
function ForkedWorker() {
    if (!(this instanceof ForkedWorker)) {
        return new ForkedWorker();
    }
    var self = this;
    process
        .on('message', function(message) {
            if (message.event === 'data') {
                process.nextTick(function() {
                    self.emit(
                        'data',
                        message.data,
                        function dataCallBack(err, data) {
                            if (process.connected) {
                                if (err) {
                                    process.send({ event: 'error', instanceId: process.pid, data: err });
                                } else {
                                    process.send({ event: 'data', instanceId: process.pid, data: data });
                                }
                                
                            }
                        });
                });
            }
        })
        .on('disconnect', function() {
            self.emit('disconnect');
        });
}
util.inherits(ForkedWorker, EventEmitter);

/**
 * Notifies the pool this worker is initialized and ready to process data.
 */
ForkedWorker.prototype.start = function() {
    if (process.connected) {
        process.send({ event: 'started', instanceId: process.pid });
    }
    return this;
};

module.exports = ForkedWorker;