wikimedia/mediawiki-extensions-Wikibase

<?php

declare( strict_types=1 );
namespace Wikibase\Lib\TermFallbackCache;

use Psr\SimpleCache\CacheInterface;
use Wikibase\DataModel\Entity\EntityId;
use Wikibase\DataModel\Term\TermFallback;
use Wikibase\Lib\Store\TermCacheKeyBuilder;

/**
 * TermFallbackCacheFacade is class to allow for simplified
 * interaction with the shared cache used for storing TermFallback objects
 * (also known as the term fallback cache or formatter cache).
 *
 * The cache returns TermFallbackCacheFacade::NO_VALUE in the
 * case there is no entry in the cache.
 *
 * Storing null values is also allowed as this indicates we
 * have already checked the database for the term but found nothing.
 *
 * @license GPL-2.0-or-later
 */
class TermFallbackCacheFacade {

    use TermFallbackSerializerTrait;
    use TermCacheKeyBuilder;

    public const NO_VALUE = false;

    /**
     * @var CacheInterface
     */
    private $cache;

    /**
     * @var int
     */
    private $cacheTtlInSeconds;

    public function __construct(
        CacheInterface $cache,
        int $cacheTtlInSeconds
    ) {
        $this->cache = $cache;
        $this->cacheTtlInSeconds = $cacheTtlInSeconds;
    }

    /**
     * @param EntityId $targetEntityId
     * @param int $revisionId
     * @param string $languageCode
     * @param string $termType
     * @return false|TermFallback|null
     *  - returning null indicates we have already checked the database and stored it's null response in the cache.
     *  - returning false indicates there is no cache entry.
     */
    public function get( EntityId $targetEntityId, int $revisionId, string $languageCode, string $termType ) {
        $cacheKey = $this->buildCacheKey( $targetEntityId, $revisionId, $languageCode, $termType );
        $termFallback = $this->cache->get( $cacheKey, self::NO_VALUE );

        if ( $termFallback === self::NO_VALUE ) {
            return self::NO_VALUE;
        }

        return $this->unserialize( $termFallback );
    }

    /**
     * @param null|TermFallback $termFallback
     * @param EntityId $targetEntityId
     * @param int $revisionId
     * @param string $languageCode
     * @param string $termType
     */
    public function set(
        ?TermFallback $termFallback,
        EntityId $targetEntityId,
        int $revisionId,
        string $languageCode,
        string $termType
    ): void {
        $cacheKey = $this->buildCacheKey( $targetEntityId, $revisionId, $languageCode, $termType );
        $serialization = $this->serialize( $termFallback );

        $this->cache->set( $cacheKey, $serialization, $this->cacheTtlInSeconds );
    }
}