PopulationTask.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\world\generator;
 
use pocketmine\scheduler\AsyncTask;
use pocketmine\utils\AssumptionFailedError;
use pocketmine\world\format\Chunk;
use pocketmine\world\format\io\FastChunkSerializer;
use pocketmine\world\SimpleChunkManager;
use pocketmine\world\World;
use function array_map;
use function igbinary_serialize;
use function igbinary_unserialize;
 
class PopulationTask extends AsyncTask{
    private const TLS_KEY_ON_COMPLETION = "onCompletion";
 
    private ?string $chunk;
 
    private string $adjacentChunks;
 
    public function __construct(
        private int $worldId,
        private int $chunkX,
        private int $chunkZ,
        ?Chunk $chunk,
        array $adjacentChunks,
        \Closure $onCompletion
    ){
        $this->chunk = $chunk !== null ? FastChunkSerializer::serializeTerrain($chunk) : null;
 
        $this->adjacentChunks = igbinary_serialize(array_map(
            fn(?Chunk $c) => $c !== null ? FastChunkSerializer::serializeTerrain($c) : null,
            $adjacentChunks
        )) ?? throw new AssumptionFailedError("igbinary_serialize() returned null");
 
        $this->storeLocal(self::TLS_KEY_ON_COMPLETION, $onCompletion);
    }
 
    public function onRun() : void{
        $context = ThreadLocalGeneratorContext::fetch($this->worldId);
        if($context === null){
            throw new AssumptionFailedError("Generator context should have been initialized before any PopulationTask execution");
        }
        $generator = $context->getGenerator();
        $manager = new SimpleChunkManager($context->getWorldMinY(), $context->getWorldMaxY());
 
        $chunk = $this->chunk !== null ? FastChunkSerializer::deserializeTerrain($this->chunk) : null;
 
        $serialChunks = igbinary_unserialize($this->adjacentChunks);
        $chunks = array_map(
            function(?string $serialized) : ?Chunk{
                if($serialized === null){
                    return null;
                }
                $chunk = FastChunkSerializer::deserializeTerrain($serialized);
                $chunk->clearTerrainDirtyFlags(); //this allows us to avoid sending existing chunks back to the main thread if they haven't changed during generation
                return $chunk;
            },
            $serialChunks
        );
 
        self::setOrGenerateChunk($manager, $generator, $this->chunkX, $this->chunkZ, $chunk);
 
        $resultChunks = []; //this is just to keep phpstan's type inference happy
        foreach($chunks as $relativeChunkHash => $c){
            World::getXZ($relativeChunkHash, $relativeX, $relativeZ);
            $resultChunks[$relativeChunkHash] = self::setOrGenerateChunk($manager, $generator, $this->chunkX + $relativeX, $this->chunkZ + $relativeZ, $c);
        }
        $chunks = $resultChunks;
 
        $generator->populateChunk($manager, $this->chunkX, $this->chunkZ);
        $chunk = $manager->getChunk($this->chunkX, $this->chunkZ);
        if($chunk === null){
            throw new AssumptionFailedError("We just generated this chunk, so it must exist");
        }
        $chunk->setPopulated();
 
        $this->chunk = FastChunkSerializer::serializeTerrain($chunk);
 
        $serialChunks = [];
        foreach($chunks as $relativeChunkHash => $c){
            $serialChunks[$relativeChunkHash] = $c->isTerrainDirty() ? FastChunkSerializer::serializeTerrain($c) : null;
        }
        $this->adjacentChunks = igbinary_serialize($serialChunks) ?? throw new AssumptionFailedError("igbinary_serialize() returned null");
    }
 
    private static function setOrGenerateChunk(SimpleChunkManager $manager, Generator $generator, int $chunkX, int $chunkZ, ?Chunk $chunk) : Chunk{
        $manager->setChunk($chunkX, $chunkZ, $chunk ?? new Chunk([], false));
        if($chunk === null){
            $generator->generateChunk($manager, $chunkX, $chunkZ);
            $chunk = $manager->getChunk($chunkX, $chunkZ);
            if($chunk === null){
                throw new AssumptionFailedError("We just set this chunk, so it must exist");
            }
        }
        return $chunk;
    }
 
    public function onCompletion() : void{
        $onCompletion = $this->fetchLocal(self::TLS_KEY_ON_COMPLETION);
 
        $chunk = $this->chunk !== null ?
            FastChunkSerializer::deserializeTerrain($this->chunk) :
            throw new AssumptionFailedError("Center chunk should never be null");
 
        $serialAdjacentChunks = igbinary_unserialize($this->adjacentChunks);
        $adjacentChunks = [];
        foreach($serialAdjacentChunks as $relativeChunkHash => $c){
            if($c !== null){
                $adjacentChunks[$relativeChunkHash] = FastChunkSerializer::deserializeTerrain($c);
            }
        }
 
        $onCompletion($chunk, $adjacentChunks);
    }
}