BlockContentUuidLookup.php

<?php

namespace Drupal\block_content;

use Drupal\Core\Cache\CacheBackendInterface;
use Drupal\Core\Cache\CacheCollector;
use Drupal\Core\Entity\EntityTypeManagerInterface;
use Drupal\Core\Lock\LockBackendInterface;

/**
 * A cache collector that caches IDs for block_content UUIDs.
 *
 * As block_content entities are used as block plugin derivatives, it is a
 * fairly safe limitation that there are not hundreds of them, a site will
 * likely run into problems with too many block content entities in other places
 * than a cache that only stores UUID's and IDs. The same assumption is not true
 * for other content entities.
 *
 * @internal
 */
class BlockContentUuidLookup extends CacheCollector {
    
    /**
     * The entity type manager.
     *
     * @var \Drupal\Core\Entity\EntityTypeManagerInterface
     */
    protected $entityTypeManager;
    
    /**
     * Constructs a BlockContentUuidLookup instance.
     *
     * @param \Drupal\Core\Cache\CacheBackendInterface $cache
     *   The cache backend.
     * @param \Drupal\Core\Lock\LockBackendInterface $lock
     *   The lock backend.
     * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
     *   The entity type manager.
     */
    public function __construct(CacheBackendInterface $cache, LockBackendInterface $lock, EntityTypeManagerInterface $entity_type_manager) {
        parent::__construct('block_content_uuid', $cache, $lock);
        $this->entityTypeManager = $entity_type_manager;
    }
    
    /**
     * {@inheritdoc}
     */
    protected function resolveCacheMiss($key) {
        $ids = $this->entityTypeManager
            ->getStorage('block_content')
            ->getQuery()
            ->accessCheck(FALSE)
            ->condition('uuid', $key)
            ->execute();
        // Only cache if there is a match, otherwise creating new entities would
        // require to invalidate the cache.
        $id = reset($ids);
        if ($id) {
            $this->storage[$key] = $id;
            $this->persist($key);
        }
        return $id;
    }

}