Drupal 8 - Truncate <title> and <meta title> before suffix

Drupal 8 - Truncate title before suffix

function mytheme_preprocess_html(&$variables) {
    // truncate <title> to 58 characters, including the brand
    $title_length = strlen($variables['head_title']['title']);
    $ti_str_limit = 58;
    $title_suffix = ' | My Company, LLC.';
    $suffix_length = strlen($title_suffix);
    $allowable_length = $ti_str_limit - $suffix_length;
    $allowable_length_w_ellipse = $allowable_length - 3;

    if (strpos($variables['head_title']['title'], $title_suffix) == false) {
      $variables['head_title']['title'] = $title_length > $allowable_length ? substr($variables['head_title']['title'], 0, $allowable_length_w_ellipse) . '...' : $variables['head_title']['title'];
      $variables['head_title']['title'] .= $title_suffix;
    }
}

function mytheme_page_attachments_alter(array &$attachments) {
  foreach($attachments['#attached']['html_head'] as &$head_item) {
    switch ($head_item[1]) {
      case 'title':
        // truncate title metatag to 58 characters, including the brand
        $title_length = strlen($head_item[0]['#attributes']['content']);
        $ti_str_limit = 58;
        $title_suffix = ' | My Company, LLC.';
        $suffix_length = strlen($title_suffix);
        $allowable_length = $ti_str_limit - $suffix_length;
        $allowable_length_w_ellipse = $allowable_length - 3;

        if (strpos($head_item[0]['#attributes']['content'], $title_suffix) == false) {
          $head_item[0]['#attributes']['content'] = $title_length > $allowable_length ? substr($head_item[0]['#attributes']['content'], 0, $allowable_length_w_ellipse) . '...' : $head_item[0]['#attributes']['content'];
          $head_item[0]['#attributes']['content'] .= $title_suffix;
        }
        break;
    }
  }