无法获得实际的文件大小

Question

我正在开设一个类，其目的是限制用户在任何30秒的时间内只发出10个请求。它利用文件来维护IP地址，持续请求时间。以及他们所做的尝试次数。问题是，无论我尝试什么，我都无法获得文件大小。我尝试过使用clearstatcache()，我尝试使用我在PHP手册的filesize（）页面的注释中找到的函数。

这是代码，它处于当前的调试状态。

// Makes sure user can only try to generate a coupon x number of times over x amount of seconds
class IpChecker{    
    const WAIT_TIME = 30; //seconds until user can try again
    const MAX_TRIES = 10; // maximum tries

    const COUPON_IP = 0;
    const COUPON_TIME = 1;
    const COUPON_TRIES = 2;

    private $ip_data;
    private $path;
    private $fh;
    private $safe;

    public function __construct(){
        clearstatcache();

        $this->path = realpath(dirname(__FILE__))."/ips/.ips";
        $this->fh = fopen($this->path,'w+');
        $this->filesize = $this->realfilesize($this->fh);
        echo "fs: ".$this->filesize; exit;


        $this->getIPs();
        $this->checkIP();
        $this->logRequest();
        fclose($this->fh);
        $this->safe || die(json_encode("You have exhausted all available tries. Please try again later."));
    }

    private function logRequest(){
        $str = "";
        foreach($this->ip_data as $data){
            foreach($data as $col){
                if(self::WAIT_TIME < (time() - $col[self::COUPON_TIME])) $str .= $col."\t";
            }
            $str = rtrim($str, '\t');
            $str .= "\n";
        }
        $str = rtrim($str, '\n');
        try{
            $fw = fwrite($this->fh, $str) || die(json_encode("Unable to check IP"));
        }catch(Exception $e){
            die(json_encode($e));
        }
    }

    private function checkIP(){     
        $IP = $_SERVER['REMOTE_ADDR'];
        $TIME = time();
        $safe = true;
        $user_logged = false;
        echo "<pre>"; var_dump($this->ip_data); exit;
        foreach($this->ip_data as $key=>$data){
            echo "<prE>"; var_dump($data); exit;
//          if($data[$key][self::COUPON_IP] == $IP){
//              $user_logged = true;
//              if(
//                  (($TIME - $data[$key][self::COUPON_TIME]) < self::WAIT_TIME) ||
//                  (self::MAX_TRIES >= $data[$key][self::COUPON_TRIES])
//              ) $safe = false;
//              $this->ip_data[$key][self::COUPON_TRIES] = $this->ip_data[$key][self::COUPON_TRIES]+1;
//              $this->ip_data[$key][self::COUPON_TIME] = $TIME;
//          }
        }
        if(!$user_logged){
            die("user not logged");
            $this->ip_data[] = array(
                self::COUPON_IP => $IP,
                self::COUPON_TIME => $TIME,
                self::COUPON_TRIES => 1
            );
        }
        $this->safe = $safe;
    }

    private function getIPs(){
        $IP_DATA = array();
        echo file_get_contents($this->path); exit;
        // this always returns 0. 
        $size = filesize($this->path);
        echo "filesize: ".$size; exit;
        if($size){
            $IPs = fread($this->fh,$size);
            $IP_ARR = explode("\n",$IPs);
            foreach($IP_ARR as $line) $IP_DATA[] = explode("\t",$line);
        }
        $this->ip_data = $IP_DATA;
    }

    // Copied from the comments in the PHP Manual for filesize()
    public function realfilesize($fp) {
        $return = false;
        if (is_resource($fp)) {
            if (PHP_INT_SIZE < 8) {
                // 32bit
                if (0 === fseek($fp, 0, SEEK_END)) {
                    $return = 0.0;
                    $step = 0x7FFFFFFF;
                    while ($step > 0) {
                        if (0 === fseek($fp, - $step, SEEK_CUR)) {
                            $return += floatval($step);
                        } else {
                            $step >>= 1;
                        }
                    }
                }
            } elseif (0 === fseek($fp, 0, SEEK_END)) {
                // 64bit
                $return = ftell($fp);
            }
        }
        return $return;
    }
}

如何获得真正的文件大小？我在PHP 5.2上。