基于时间随机返回比率的随机值

$config = array(
    'sohu' => 10,
    'sina' => 30,
    'qq' => 20,
    'baidu' => 20,
);

echo randomBaseTimestamp($config);

function randomBaseTimestamp($data = array()) {
    uasort($data, function ($a, $b) {
        return rand(-1, 1);
    });
    $time = time();
    $total = array_sum($data);
    $mod = $time%$total;
    $result = '';
    foreach($data as $k => $v) {
        $result = $k;
        $mod -= $v;
        if($mod<=0) {
            break;
        }
    }

    return $result;
}