wikimedia/mediawiki-extensions-Wikibase

<?php
declare( strict_types=1 );

namespace Wikibase\Lib\Store;

use Wikimedia\ObjectCache\BagOStuff;

/**
 * ItemOrderProvider implementation, that caches the information
 *
 * @license GPL-2.0-or-later
 * @author Noa Rave
 */
class CachingItemOrderProvider implements ItemOrderProvider {

    /**
     * @var ItemOrderProvider
     */
    private $itemOrderProvider;

    /**
     * The cache to use for caching the Item
     * order.
     *
     * @var BagOStuff
     */
    private $cache;

    /**
     * The cache key under which the cached
     * item order will be stored.
     *
     * @var string
     */
    private $cacheKey;

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

    public function __construct(
        ItemOrderProvider $itemOrderProvider,
        BagOStuff $cache,
        string $cacheKey,
        int $cacheDuration = 3600
    ) {
        $this->itemOrderProvider = $itemOrderProvider;
        $this->cache = $cache;
        $this->cacheKey = $cacheKey;
        $this->cacheDuration = $cacheDuration;
    }

    /**
     * @see ItemOrderProvider::getItemOrder
     * @return int[]|null
     */
    public function getItemOrder(): ?array {
        $cached = $this->cache->getWithSetCallback(
            $this->cache->makeKey( $this->cacheKey ),
            $this->cacheDuration,
            function () {
                $itemOrder = $this->itemOrderProvider->getItemOrder();
                if ( $itemOrder !== null ) {
                    return $itemOrder;
                } else {
                    return false;
                }
            }
        );
        if ( $cached !== false ) {
            return $cached;
        } else {
            return null;
        }
    }

}