EventEmitterFn.js

'use strict'; var fs = require('fs'); var util = require('util'); var EventEmitter = require('events').EventEmitter; var FilesizeWatcher = function(path) { var self = this; if (/^\//.test(path) === false) { process.nextTick(function() { self.emit('error', 'Path does not start with a slash'); }); return; } fs.stat(path, function(err, stats) { self.lastfilesize = stats.size; }); self.interval = setInterval( function() { fs.stat(path, function(err, stats) { if (stats.size > self.lastfilesize) { self.emit('grew', stats.size - self.lastfilesize); self.lastfilesize = stats.size; } if (stats.size < self.lastfilesize) { self.emit('shrank', self.lastfilesize - stats.size); self.lastfilesize = stats.size; } }, 1000); }); }; util.inherits(FilesizeWatcher, EventEmitter); FilesizeWatcher.prototype.stop = function() { clearInterval(this.interval); }; module.exports = FilesizeWatcher;