//日志内容
$content = [
    'date:' => date("Ymd H:i:s"),
    'get:' => $request->get,
    'post:' => $request->post,
    'header:' => $request->header,
];
//存入文件
swoole_async_writefile(__DIR__."/access.log", json_encode($content).PHP_EOL, function($filename){
    // todo
}, FILE_APPEND);