PHP异步处理及在Drupal中的应用（续）

/**
 * Output text & set php in async mode.
 *
 * @param $output
 *  string - Text to output to open connection.
 * @param $wait
 *  bool - Wait 1 second?
 * @param $content_type
 *  string - Content type header.
 */
function boost_async_opp($output, $wait = TRUE, $content_type = "text/html; charset=utf-8", $length = 0) {
  // Calculate Content Lenght
  if ($length == 0) {
    $output .= "\n";
    $length = (mb_strlen($output, '8bit')-1);
  }
  // Prime php for background operations
  $loop = 0;
  while (ob_get_level() && $loop < 25) {
    ob_end_clean();
    $loop++;
  }
  header("Connection: close");
  ignore_user_abort();
 
  // Output headers & data
  ob_start();
  header("Content-type: " . $content_type);
  header("Expires: Sun, 19 Nov 1978 05:00:00 GMT");
  header("Cache-Control: no-cache");
  header("Cache-Control: must-revalidate");
  header("Content-Length: " . $length);
  header("Connection: close");
  print($output);
  ob_end_flush();
  flush();
  // wait for 1 second
  if ($wait) {
    sleep(1);
  }
 
  // text returned and connection closed.
  // Do background processing. Time taken after should not effect page load times.
}

//基本示例：
 $output = get_output(); //get output for page
 boost_async_opp($output, FALSE, 'text/html; charset=utf-8'); //send $output
 //do some operations
 
 //Ajax/JSON 示例：
 $output = Drupal_json($data);
 boost_async_opp($output, FALSE, 'text/javascript; charset=utf-8'); //send json
 //继续其他操作