我试图将用户活动保存在一个json文件中，但当文件大小变大，多个用户同时工作时，json文件会删除旧记录。
这是我的特质

trait CustomLogActivity
{
    protected static function bootCustomLogActivity()
    {
        foreach (static::getModelEvents() as $event) {
            static::$event(function ($model) use ($event) {
                $model->recordActivity($event);
            });
        }
    }
    protected static function getModelEvents()
    {
        return ['created', 'updated', 'deleted'];
    }

    protected function recordActivity($event)
    {
        $activity = [
            'user_id' => Auth::id(),
            'type' => $event,
            'subject' => (new \ReflectionClass($this))->getShortName(),
            'timestamp' => now()
        ];

        if ($event === 'updated') {
            $activity['old_properties'] = $this->getOriginal();
            $activity['new_properties'] = $this->getAttributes();
        } else {
            $activity['properties'] = $this->getAttributes();
        }
        $this->appendToLog($activity);
    }

    protected function appendToLog($activity)
    {
        $logFile = 'activity.json';
        $log = json_encode($activity);
        Storage::append($logFile, $log);
    }

    protected function getActivityType($event)
    {
        $type = strtolower((new \ReflectionClass($this))->getShortName());

        return "{$event}_{$type}";
    }
}