AWS s3下载回调

Is it possible to setup a callback on completion of a download of an object from a S3 bucket? I've looked through the code and see some callbacks for upload and delete, I need to increment a counter when the object is downloaded - I'd like some guarantee that they've downloaded it instead of incrementing the counter BEFORE the download starts.

UPDATE

$s3 = App::make('aws')->get('s3');

if($s3->doesObjectExist('bucket', $url)) {
    return $s3->getObjectUrl('bucket', $url, time() + 500);
}

Currently, the returned object URL is being used in a redirect. Web app is being created w/ Laravel.