PHP在调用googledirectionsapi时在mysql循环中崩溃

我在MySQL搜索查询中运行以下函数，通常可以找到大约100个结果。该函数使用googleapi检索两个位置之间的距离。

这个问题看起来像是循环使脚本崩溃，超过10个结果。

有什么办法解决这个问题吗？

暂停谷歌回拨？

任何有帮助的建议。

function get_driving_information($start, $finish, $raw = false)
{
    if(strcmp($start, $finish) == 0)
    {
        $time = 0;
        if($raw)
        {
            $time .= ' seconds';
        }
        return array('distance' => 0, 'time' => $time);
    }
    $start  = urlencode($start);
    $finish = urlencode($finish);
    $distance   = 'unknown';
    $time       = 'unknown';
    $url = 'http://maps.googleapis.com/maps/api/directions/xml?origin='.$start.'&destination='.$finish.'&sensor=false';
    if($data = file_get_contents($url))
    {
        $xml = new SimpleXMLElement($data);
        if(isset($xml->route->leg->duration->value) AND (int)$xml->route->leg->duration->value > 0)
        {
            if($raw==true)
            {
                $distance = (string)$xml->route->leg->distance->text;
                $time     = (string)$xml->route->leg->duration->text;
            }
            if($raw=="miles")
            {
                $distance = (string)$xml->route->leg->distance->value / 1000 / 1.609344;
                $distance = number_format($distance,1)." miles";
                $time     = (string)$xml->route->leg->duration->text;
            }
            else
            {
                $distance = (int)$xml->route->leg->distance->value / 1000 / 1.609344; 
                $time     = (int)$xml->route->leg->duration->value;
            }
        }
        else
        {
            throw new Exception('Could not find that route');
        }
        //return array('distance' => $distance, 'time' => $time);
        return $distance;
    }
    else
    {
        throw new Exception('Could not resolve URL');
    }
}