记录PHP的执行时间

网上不少误导信息，实际上这个答案在PHP源码中的Zend文件夹下bench.php是有的

在此纠正下网络上复制粘贴造成的错误。希望后来人少踩点坑。

function getmicrotime()
{
  $t = gettimeofday();
  return ($t['sec'] + $t['usec'] / 1000000);
}

function start_test()
{
  ob_start();
  return getmicrotime();
}

function end_test($start, $name)
{
  global $total;
  $end = getmicrotime();
  ob_end_clean();
  $total += $end-$start;
  $num = number_format($end-$start,3);
  $pad = str_repeat(" ", 24-strlen($name)-strlen($num));

  echo $name.$pad.$num."\n";
  ob_start();
  return getmicrotime();
}

调用

$t0 = $t = start_test();
simple();
$t = end_test($t, "simple");