Second Level Cache, QueryCache, Eviction

[wtorsi]

Eviction non builded before queryCache is not allowed, or not performed in DefaultCache.
What is the reason for this limitation?

/**
     * {@inheritdoc}
     */
    public function evictQueryRegion($regionName = null)
    {
        if ($regionName === null && $this->defaultQueryCache !== null) {
            $this->defaultQueryCache->clear();

            return;
        }


        if (isset($this->queryCaches[$regionName])) {
            $this->queryCaches[$regionName]->clear();
        }
    }

According to that limitation, firstly I must create cache before clearing, using getQueryCache($region) from EntityManager::$cache, like below:

public function evictQueryCache(string $region)
    {
        $cache = $this->em->getCache();
        $region = $cache->getQueryCache($region);
        $cache->evictQueryRegion($region);
        $region->clear();
    }

What is the reason for this limitation?

[lcobucci]

@wtorsi why are you trying to do that? L2C should control eviction automatically (when you manipulate entities ofc).

[wtorsi]

Ok, I'll try to describe
I got

/**
 * @ORM\Entity(repositoryClass="AppBundle\Entity\Repository\CategoryRepository")
 * @ORM\Cache(usage="NONSTRICT_READ_WRITE")
 */
class Category 
{

    /**
     * @var integer
     * @ORM\Column(type="integer")
     * @ORM\Id
     * @ORM\GeneratedValue
     */
    protected $id;
    /**
     * @var Media[]
     * @ORM\Cache(usage="NONSTRICT_READ_WRITE")
     * @ORM\OneToMany(targetEntity="AppBundle\Entity\Media", cascade={"remove"}, mappedBy="category")
     * @ORM\OrderBy({"sortOrder" = "ASC"})
     */
    private $medias;
}

And accordingly I have

/**
 * @ORM\Entity(repositoryClass="AppBundle\Entity\Repository\MediaRepository")
 * @ORM\Cache(usage="NONSTRICT_READ_WRITE")
 */
class Media
{
    /**
     * @var integer
     * @ORM\Column(type="integer")
     * @ORM\Id
     * @ORM\GeneratedValue
     */
    private $id;
    /**
     * @var Category
     * @ORM\Cache(usage="NONSTRICT_READ_WRITE")
     * @ORM\ManyToOne(targetEntity="AppBundle\Entity\Category", inversedBy="medias")
     * @ORM\JoinColumn(name="category_id", referencedColumnName="id", nullable=false, onDelete="CASCADE")
     */
    private $category;
}

In my controller, I'm trying to get Category with Medias , sorted by sortOrder
using this query

public function findByTag(bool $enabled = true)
    {
        $qb = $this->createQueryBuilder("c", "c.id");
        $qb
            ->setCacheable(true)
            ->setCacheRegion(CategoryCache::CACHE_QUERY_CATEGORY)
            ->setLifetime(3600);

        $qb
            ->leftJoin("c.medias", "m")->addSelect("m")
            ->where($qb->expr()->eq("c.enabled", ":enabled"))
            ->andWhere($qb->expr()->eq("c.tag", ":tag"))
            ->setParameter("enabled", $enabled)
            ->setParameter("tag", $tag)
            ->orderBy("c.sortOrder");

        return $qb->getQuery()->getResult();
    }

Regions
Media is stored in media_region,
Category is stored in category_region,
QueryBuilder Query is stored in query_cache_region

And now the problem.
In case if I only change order of Media entity, I want that my order of joined entities in query also changed, but this is not working, because, I think, category_region is not changed.

\\ Doctrine\ORM\Cache\DefaultQueryCache;

/** @var $key QueryCacheKey */ 
$entry = $this->region->get($key); // CacheProvider returns cached sortOrder 
....
// $key with region set by root entity Category, so it is passed
 if ( ! $this->validator->isValid($key, $entry)) {
            $this->region->evict($key);
            return null;
}
....
foreach ($entry['associations'] as $name => $assoc) {
    ....
    foreach ($assoc['list'] as $assocIndex => $assocId) { // cached sortOrder :(
        if (($assocEntry = $assocRegion->get($assocKey = new EntityCacheKey($assoc['targetEntity'], $assocId))) === null) {
            ....
            return null; //not called,  and everything is ok
        }
    }
    ....
}

Setting custom region for query_builder is just a solution to not clear all cache for all builders.
Also, clearing association cache for CategoryEntity (my first thought, and I hope best solution) did not help, because there is no checks for that in hydration block in DefaultQueryCache code.

[lcobucci]

@wtorsi sorry by the very huge delay!

We fixed several L2C bugs so would you mind checking this again using the latest version of master or even with the changes of #6244 (if it's not merged yet)?