redirect-8.x-1.x-dev/modules/redirect_404/redirect_404.module

<?php

/**
 * @file
 * Module file for redirect_404.
 */

use Drupal\Core\Form\FormStateInterface;
use Drupal\Core\Language\LanguageInterface;
use Drupal\Core\Url;
use Drupal\redirect\Entity\Redirect;

/**
 * Implements hook_cron().
 *
 * Adds clean up job to drop the irrelevant rows from the redirect_404 table.
 */
function redirect_404_cron() {
  /** @var \Drupal\redirect_404\SqlRedirectNotFoundStorage $redirect_storage */
  $redirect_storage = \Drupal::service('redirect.not_found_storage');
  $redirect_storage->purgeOldRequests();

  $last_daily_reset = \Drupal::state()->get('redirect_404.last_daily_reset', 0);

  if (date('d', $last_daily_reset) != date('d')) {
    $redirect_storage->resetDailyCount();

    \Drupal::state()->set('redirect_404.last_daily_reset', \Drupal::time()->getRequestTime());
  }
}

/**
 * Implements hook_form_FORM_ID_alter() for system_logging_settings().
 */
function redirect_404_form_redirect_settings_form_alter(&$form, FormStateInterface $form_state, $form_id) {
  $config = \Drupal::configFactory()->getEditable('redirect_404.settings');

  $row_limits = [100, 1000, 10000, 100000, 1000000];
  $form['row_limit'] = [
    '#type' => 'select',
    '#title' => t('404 error database logs to keep'),
    '#default_value' => $config->get('row_limit'),
    '#options' => [0 => t('All')] + array_combine($row_limits, $row_limits),
    '#description' => t('The maximum number of 404 error logs to keep in the database log. Requires a <a href=":cron">cron maintenance task</a>.', [':cron' => Url::fromRoute('system.status')->toString()]),
  ];

  $form['reset_404'] = [
    '#type' => 'submit',
    '#value' => t('Clear all 404 log entries'),
    '#submit' => ['redirect_404_reset_submit'],
  ];

  $ignored_pages = $config->get('pages');
  // Add a new path to be ignored, if there is an ignore argument in the query.
  if ($path_to_ignore = \Drupal::request()->query->get('ignore')) {
    $ignored_pages .= $path_to_ignore;
  }

  // Replace '\r\n' with '\n' to keep consistency in tests.
  // See: https://www.drupal.org/project/redirect/issues/3244924
  $ignored_pages = str_replace("\r\n", "\n", $ignored_pages);

  $form['ignore_pages'] = [
    '#type' => 'textarea',
    '#title' => t('Pages to ignore'),
    '#default_value' => $ignored_pages,
    '#description' => t("Specify pages by using their paths. Enter one path per line. The '*' character is a wildcard. An example path is %user-wildcard for every user page. %front is the front page.", [
      '%user-wildcard' => '/user/*',
      '%front' => '<front>',
    ]),
  ];

  $form['clear_ignored'] = [
    '#type' => 'checkbox',
    '#title' => t('Clear ignored 404 log entries when saving this form'),
    '#default_value' => FALSE,
  ];

  $form['suppress_404'] = [
    '#type' => 'checkbox',
    '#title' => t("Suppress 'page not found' log messages"),
    '#default_value' => $config->get('suppress_404'),
    '#description' => t("Prevents logging 'page not found' events. Can be safely enabled when redirect_404 module is used, which stores them separately, nothing else relies on those messages."),
  ];

  $form['#submit'][] = 'redirect_404_logging_settings_submit';
}

/**
 * Form submission handler for system_logging_settings().
 *
 * @see redirect_404_form_redirect_settings_form_alter()
 */
function redirect_404_logging_settings_submit($form, FormStateInterface $form_state) {
  // Make sure to store the 'pages to ignore' with the leading slash.
  $ignore_pages = explode(PHP_EOL, $form_state->getValue('ignore_pages'));
  $pages = '';
  foreach ($ignore_pages as $page) {
    if (!empty($page)) {
      $pages .= '/' . ltrim($page, '/') . "\n";
    }
  }

  \Drupal::configFactory()
    ->getEditable('redirect_404.settings')
    ->set('row_limit', $form_state->getValue('row_limit'))
    ->set('pages', $pages)
    ->set('suppress_404', $form_state->getValue('suppress_404'))
    ->save();

  // Remove the filtered out items.
  /** @var \Drupal\redirect_404\RedirectNotFoundStorageInterface $redirect_storage */
  $redirect_storage = \Drupal::service('redirect.not_found_storage');
  foreach ($ignore_pages as $ignore_page) {
    $redirect_storage->resolveLogRequest(trim($ignore_page));
  }
}

/**
 * Implements hook_ENTITY_TYPE_presave() for redirect entities.
 */
function redirect_404_redirect_presave(Redirect $redirect) {
  $path = $redirect->getSourcePathWithQuery();
  $langcode = $redirect->get('language')->value;

  if ($langcode == LanguageInterface::LANGCODE_NOT_SPECIFIED) {
    $langcode = NULL;
  }

  // Mark a potentially existing log entry for this path as resolved.
  \Drupal::service('redirect.not_found_storage')->resolveLogRequest($path, $langcode);
}

/**
 * Submit Handler for resetting all the 404 logs from Database.
 */
function redirect_404_reset_submit() {
  \Drupal::database()->truncate('redirect_404')->execute();
}