RuntimeEnumMetadata.php

<?php
 
/*
 *
 *  ____            _        _   __  __ _                  __  __ ____
 * |  _ \ ___   ___| | _____| |_|  \/  (_)_ __   ___      |  \/  |  _ \
 * | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
 * |  __/ (_) | (__|   <  __/ |_| |  | | | | | |  __/_____| |  | |  __/
 * |_|   \___/ \___|_|\_\___|\__|_|  |_|_|_| |_|\___|     |_|  |_|_|
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * @author PocketMine Team
 * @link http://www.pocketmine.net/
 *
 *
 */
 
declare(strict_types=1);
 
namespace pocketmine\data\runtime;
 
use function ceil;
use function count;
use function log;
use function spl_object_id;
use function usort;
 
final class RuntimeEnumMetadata{
    public readonly int $bits;
 
    private readonly array $intToEnum;
    private readonly array $enumToInt;
 
    public function __construct(
        array $members
    ){
        usort($members, fn(\UnitEnum $a, \UnitEnum $b) => $a->name <=> $b->name); //sort by name to ensure consistent ordering (and thus consistent bit assignments)
 
        $this->bits = (int) ceil(log(count($members), 2));
        $this->intToEnum = $members; //usort strips keys so this is already a list
 
        $reversed = [];
        foreach($this->intToEnum as $int => $enum){
            $reversed[spl_object_id($enum)] = $int;
        }
 
        $this->enumToInt = $reversed;
    }
 
    public function intToEnum(int $value) : ?object{
        return $this->intToEnum[$value] ?? null;
    }
 
    public function enumToInt(object $enum) : int{
        return $this->enumToInt[spl_object_id($enum)];
    }
 
    private static array $cache = [];
 
    public static function from(\UnitEnum $case) : self{
        $class = $case::class;
        $metadata = self::$cache[$class] ?? null;
        if($metadata === null){
            $cases = $case::cases();
            self::$cache[$class] = $metadata = new self($cases);
        }
 
        return $metadata;
    }
}