PHP静态文件缓存的实现

直接上代码:

class File
{
    private $_dir;
    const EXT = '.txt';
    public function __construct()
    {
        $this->_dir = dirname(__FILE__) . '/files/';
    }
    public function cacheData($key = '', $value = '', $path = '')
    {
        $filename = $this->_dir . $path . $key . self::EXT;
        if ($value !== '') {
            //将$value值写入缓存
            $dir = dirname($filename);
            if (!is_dir($dir)) {
                mkdir($dir);
            }
            return file_put_contents($filename, json_encode($value));
        }
    }
}