function F($name, $value = '', $path = false)
{
    static $_cache = array();
    require_cache(ADDON_PATH . "/libs/Multi/SimpleFile.php");
    if (!$path) {
        $path = SITE_PATH . '/_runtime/_cache/';
    }
    $name = C('DATA_CACHE_PREFIX') . $name;
    SimpleFile::setRoot($path);
    $file = new SimpleFile($name);
    if ('' !== $value) {
        if (is_null($value)) {
            // 删除缓存
            return $file->rm();
        } else {
            $value = serialize($value);
            return $file->save($value);
        }
    }
    if (isset($_cache[$name])) {
        return $_cache[$name];
    }
    // 获取缓存数据
    $value = unserialize($file->read());
    if ($value) {
        $_cache[$name] = $value;
    }
    return $value;
}