Question

我正在尝试获取执行php脚本的当前剩余时间。

我试过了：

$urls1 = array(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
$total_urls = count($urls1);
foreach ($urls1 as $url) {
  $start_time = microtime(true);
  // here I do some things
  $time_end = microtime(true);
  $execution_time = $time_end - $start_time;
  $current_urls_remaining = $total_urls - 1;
  $total_time = $current_urls_remaining * floatval($execution_time);
  $timeleft = $total_time - floatval($execution_time);
  $db->query("UPDATE sessions SET timeleft = '$timeleft'");
}

//问题是它是用随机数更新的

预期输出

 Iteration 1 - Remaining approximate time let's say 5 second
 Iteration 2 - Remaining approximate time 4 seconds
 Iteration 3 - Remaining approximate time 3.5 seconds
 ...

我很确定我误解了这样做的公式，如果有人可以提供帮助，我将非常感激。我不是在谈论发明人工智能，只需要一个如何获得剩余时间的例子。

Answer 1

你必须递减$total_urls，我认为它应该有用。

例如：

$urls1 = array(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
$total_urls = count($urls1);
foreach ($urls1 as $url) {
  $start_time = microtime(true);
  // here I do some things
  $time_end = microtime(true);
  $execution_time = $time_end - $start_time;
  $current_urls_remaining = --$total_urls;
  $total_time = $current_urls_remaining * floatval($execution_time);
  $timeleft = $total_time; //former: $timeleft = $total_time - floatval($execution_time);
  $db->query("UPDATE sessions SET timeleft = '$timeleft'");
}

你永远不会以这种方式获得准确的价值，因为一旦执行可能会持续0.3秒，而下一次1.2秒会导致2.7s 第一次和9.6s 之后即可。为避免过大的变化，您应该应用平滑滤镜。

PS：当然你应该重命名/重新排列变量名称，因为没有人希望$total_urls减少每次迭代......

编辑：

避免havy变化的一种可能性是，将最后4个值的平均值作为估计持续时间：

$urls1 = array(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
$total_urls = count($urls1);
$sf_last_values = array();
foreach ($urls1 as $url) {
  $start_time = microtime(true);
  // here I do some things
  $time_end = microtime(true);

  $execution_time = $time_end - $start_time;
  $sf_last_values[] = $execution_time;
  if(count($sf_last_values) > 4)
    array_shift($sf_last_values);
  $smoothened_execution_time = array_sum($sf_last_values) / count($sf_last_values);

  $current_urls_remaining = --$total_urls;
  $total_time = $current_urls_remaining * floatval($smoothened_execution_time);
  $timeleft = $total_time; //former: $timeleft = $total_time - floatval($execution_time);
  $db->query("UPDATE sessions SET timeleft = '$timeleft'");
}

获取PHP脚本的剩余时间执行

1 个答案: