Memory leak

[vanilla38]

Hello, I noticed that memory wasnt freed after download is complete, here's my code:

`app.get('/dltorrent', function (req, res) {
var urlObj = url.parse(req.url, true),
query = urlObj.query;

if (query.magnet !== undefined && query.title !== undefined && query.magnet !== 'undefined' && query.title !== 'undefined') {
	var opts = {
		tmp: '/usr/share/nodejs/www/data',
		connections: 10,
		uploads: 0
	}
	
	var engine = torrentStream('magnet:?xt=urn:btih:' + query.magnet, opts);
	engine.on('ready', function() {
		engine.files.forEach(function(file) {
			if (file.name == query.title) {
				var stream = file.createReadStream();
					res.setHeader('Content-disposition', 'attachment; filename=' + query.title);
					res.setHeader('Content-type', mime.lookup(query.title));
					stream.pipe(res);
			}
		});
	});
} else {
	res.end('invalid dl parameters');
}

});`

[vanilla38]

Okay, I noticed that these leaks were caused by:

swarm.add(addr) => torrent-stream index.js Line 702

Any idea on how to solve it ?

[dizel3d]

The leak is reproduced on Linux, not on Windows.
I simplified the leak reproduction, see https://github.com/dizel3d/node-memory-leak-sample
I made 300 iterations and couldn't detect leaking objects using v8-profiler, comparing heap snapshots. It seems the leak has native code roots.