mymodule.post_update.php

<?php

/**
 * @file
 * Post Update hooks for the mymodule module.
 */

use Drupal\Core\Database\Database;
use Drupal\Core\Site\Settings;
use Drupal\redirect\Entity\Redirect;

/**
 * Updates redirect hashes after patch #2879648.
 *
 * @see https://www.drupal.org/project/redirect/issues/2879648#comment-13345751
 */
function mymodule_post_update_update_redirect_hashes(&$sandbox) {
  if (!isset($sandbox['progress'])) {
    $redirect_count = Database::getConnection()
      ->query('SELECT COUNT(rid) FROM {redirect}')
      ->fetchField();
    if (empty($redirect_count)) {
      return t('There were no redirects to update.');
    }

    $sandbox['progress'] = 0;
    $sandbox['updated'] = 0;
    $sandbox['deleted'] = 0;
    $sandbox['current_rid'] = 0;
    $sandbox['limit'] = Settings::get('entity_update_batch_size', 50);
    $sandbox['max'] = $redirect_count;
  }

  // Get redirects in groups keeps this process within resource limits.
  $redirect_ids = Database::getConnection()
    ->select('redirect', 'r')
    ->fields('r', ['rid'])
    ->condition('rid', $sandbox['current_rid'], '>')
    ->range(0, $sandbox['limit'])
    ->orderBy('rid', 'ASC')
    ->execute()
    ->fetchCol();

  // Get the redirect storage controller so we can call preSave() below.
  /** @var \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager */
  $entity_storage = Drupal::service('entity_type.manager')->getStorage('redirect');

  // Use preSave() to determine whether a redirect's hash has changed and only
  // update it if it has.
  foreach (Redirect::loadMultiple($redirect_ids) as $redirect) {
    $old_hash = $redirect->getHash();
    $redirect->preSave($entity_storage);
    $new_hash = $redirect->getHash();

    if ($old_hash !== $new_hash) {
      // Check if the hash already exists.
      $existing = Database::getConnection()
        ->select('redirect', 'r')
        ->fields('r', ['rid'])
        ->condition('hash', $new_hash)
        ->execute()
        ->fetchField();

      if ($existing !== FALSE) {
        // If so, delete this redirect.
        $redirect->delete();
        $sandbox['deleted']++;
      }
      else {
        // Otherwise, update it.
        $redirect->save();
        $sandbox['updated']++;
      }
    }
    $sandbox['progress']++;
    $sandbox['current_rid'] = $redirect->id();
  }

  // Update the batch progress.
  $sandbox['#finished'] = empty($sandbox['max']) ? 1 : $sandbox['progress'] / $sandbox['max'];
  if ($sandbox['#finished'] >= 1) {
    return t('Updated redirects: %updated, deleted redirects: %deleted.', [
      '%updated' => $sandbox['updated'],
      '%deleted' => $sandbox['deleted'],
    ]);
  }
}