/**
 * 获取当前日期带毫秒
 * @return string
 */
function ts_time() {
    date_default_timezone_set('PRC');
    $mtimestamp = sprintf("%.3f", microtime(true)); // 带毫秒的时间戳

    $timestamp = floor($mtimestamp); // 时间戳
    $milliseconds = round(($mtimestamp - $timestamp) * 1000); // 毫秒

    $datetime = date("Y-m-d H:i:s", $timestamp) . '.' . $milliseconds;
    return $datetime;// 2018-04-16 13:26:14.820
}