HandlerList.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\event;
 
use pocketmine\plugin\Plugin;
use function array_merge;
use function krsort;
use function spl_object_id;
use const SORT_NUMERIC;
 
class HandlerList{
    private array $handlerSlots = [];
 
    private array $affectedHandlerCaches = [];
 
    public function __construct(
        private string $class,
        private ?HandlerList $parentList,
        private RegisteredListenerCache $handlerCache = new RegisteredListenerCache()
    ){
        for($list = $this; $list !== null; $list = $list->parentList){
            $list->affectedHandlerCaches[spl_object_id($this->handlerCache)] = $this->handlerCache;
        }
    }
 
    public function register(RegisteredListener $listener) : void{
        if(isset($this->handlerSlots[$listener->getPriority()][spl_object_id($listener)])){
            throw new \InvalidArgumentException("This listener is already registered to priority {$listener->getPriority()} of event {$this->class}");
        }
        $this->handlerSlots[$listener->getPriority()][spl_object_id($listener)] = $listener;
        $this->invalidateAffectedCaches();
    }
 
    public function registerAll(array $listeners) : void{
        foreach($listeners as $listener){
            $this->register($listener);
        }
        $this->invalidateAffectedCaches();
    }
 
    public function unregister(RegisteredListener|Plugin|Listener $object) : void{
        if($object instanceof Plugin || $object instanceof Listener){
            foreach($this->handlerSlots as $priority => $list){
                foreach($list as $hash => $listener){
                    if(($object instanceof Plugin && $listener->getPlugin() === $object)
                        || ($object instanceof Listener && (new \ReflectionFunction($listener->getHandler()))->getClosureThis() === $object) //this doesn't even need to be a listener :D
                    ){
                        unset($this->handlerSlots[$priority][$hash]);
                    }
                }
            }
        }else{
            unset($this->handlerSlots[$object->getPriority()][spl_object_id($object)]);
        }
        $this->invalidateAffectedCaches();
    }
 
    public function clear() : void{
        $this->handlerSlots = [];
        $this->invalidateAffectedCaches();
    }
 
    public function getListenersByPriority(int $priority) : array{
        return $this->handlerSlots[$priority] ?? [];
    }
 
    public function getParent() : ?HandlerList{
        return $this->parentList;
    }
 
    private function invalidateAffectedCaches() : void{
        foreach($this->affectedHandlerCaches as $cache){
            $cache->list = null;
        }
    }
 
    public function getListenerList() : array{
        if($this->handlerCache->list !== null){
            return $this->handlerCache->list;
        }
 
        $handlerLists = [];
        for($currentList = $this; $currentList !== null; $currentList = $currentList->parentList){
            $handlerLists[] = $currentList;
        }
 
        $listenersByPriority = [];
        foreach($handlerLists as $currentList){
            foreach($currentList->handlerSlots as $priority => $listeners){
                $listenersByPriority[$priority] = array_merge($listenersByPriority[$priority] ?? [], $listeners);
            }
        }
 
        //TODO: why on earth do the priorities have higher values for lower priority?
        krsort($listenersByPriority, SORT_NUMERIC);
 
        return $this->handlerCache->list = array_merge(...$listenersByPriority);
    }
}