SplPriorityQueue.php

<?php

declare(strict_types=1);

/*
 * CoreShop
 *
 * This source file is available under two different licenses:
 *  - GNU General Public License version 3 (GPLv3)
 *  - CoreShop Commercial License (CCL)
 * Full copyright and license information is available in
 * LICENSE.md which is distributed with this source code.
 *
 * @copyright  Copyright (c) CoreShop GmbH (https://www.coreshop.org)
 * @license    https://www.coreshop.org/license     GPLv3 and CCL
 *
 */

namespace CoreShop\Component\Pimcore;

use function array_key_exists;
use function get_debug_type;
use function is_array;
use const PHP_INT_MAX;
use ReturnTypeWillChange;
use Serializable;
use function serialize;
use function sprintf;
use UnexpectedValueException;
use function unserialize;

/**
 * Serializable version of SplPriorityQueue
 *
 * Also, provides predictable heap order for datums added with the same priority
 * (i.e., they will be emitted in the same order they are enqueued).
 *
 * @template TValue
 * @template TPriority of int
 *
 * @extends \SplPriorityQueue<TPriority, TValue>
 */
class SplPriorityQueue extends \SplPriorityQueue implements Serializable
{
    /** @var int Seed used to ensure queue order for items of the same priority */
    protected $serial = PHP_INT_MAX;

    /**
     * Insert a value with a given priority
     *
     * Utilizes {@var $serial} to ensure that values of equal priority are
     * emitted in the same order in which they are inserted.
     *
     * @param  TValue    $value
     * @param  TPriority $priority
     */
    #[ReturnTypeWillChange] // Inherited return type should be bool
    public function insert($value, $priority)
    {
        if (!is_array($priority)) {
            $priority = [$priority, $this->serial--];
        }

        parent::insert($value, $priority);
    }

    /**
     * Serialize to an array
     *
     * Array will be priority => data pairs
     *
     * @return list<TValue>
     */
    public function toArray()
    {
        $array = [];
        foreach (clone $this as $item) {
            $array[] = $item;
        }

        return $array;
    }

    /**
     * Serialize
     *
     * @return string
     */
    public function serialize()
    {
        return serialize($this->__serialize());
    }

    /**
     * Magic method used for serializing of an instance.
     *
     * @return array
     */
    public function __serialize()
    {
        $clone = clone $this;
        $clone->setExtractFlags(self::EXTR_BOTH);

        $data = [];
        foreach ($clone as $item) {
            $data[] = $item;
        }

        return $data;
    }

    /**
     * Deserialize
     *
     * @param  string $data
     */
    public function unserialize($data)
    {
        $toUnserialize = unserialize($data);
        if (!is_array($toUnserialize)) {
            throw new UnexpectedValueException(sprintf(
                'Cannot deserialize %s instance; corrupt serialization data',
                self::class,
            ));
        }

        $this->__unserialize($toUnserialize);
    }

    /**
     * Magic method used to rebuild an instance.
     *
     * @param array<array-key, mixed> $data Data array.
     */
    public function __unserialize($data)
    {
        $this->serial = PHP_INT_MAX;

        foreach ($data as $item) {
            if (!is_array($item)) {
                throw new UnexpectedValueException(sprintf(
                    'Cannot deserialize %s instance: corrupt item; expected array, received %s',
                    self::class,
                    get_debug_type($item),
                ));
            }

            if (!array_key_exists('data', $item)) {
                throw new UnexpectedValueException(sprintf(
                    'Cannot deserialize %s instance: corrupt item; missing "data" element',
                    self::class,
                ));
            }

            $priority = 1;
            if (array_key_exists('priority', $item)) {
                $priority = (int) $item['priority'];
            }

            $this->insert($item['data'], $priority);
        }
    }
}