From efaf9311b332e49dc643de5237b73b1613e627cc Mon Sep 17 00:00:00 2001
From: "Dylan K. Taylor" <dktapps@pmmp.io>
Date: Wed, 30 Apr 2025 17:38:16 +0100
Subject: [PATCH] Extract population business logic from PopulationTask

---
 src/world/generator/PopulationTask.php  | 40 +++----------
 src/world/generator/PopulationUtils.php | 74 +++++++++++++++++++++++++
 2 files changed, 83 insertions(+), 31 deletions(-)
 create mode 100644 src/world/generator/PopulationUtils.php

diff --git a/src/world/generator/PopulationTask.php b/src/world/generator/PopulationTask.php
index bad134324..a8366a306 100644
--- a/src/world/generator/PopulationTask.php
+++ b/src/world/generator/PopulationTask.php
@@ -27,8 +27,6 @@ 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;
@@ -71,8 +69,6 @@ class PopulationTask extends AsyncTask{
 		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;
 
@@ -93,21 +89,15 @@ class PopulationTask extends AsyncTask{
 			$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");
-		}
-		$chunk->setPopulated();
+		[$chunk, $chunks] = PopulationUtils::populateChunkWithAdjacents(
+			$context->getWorldMinY(),
+			$context->getWorldMaxY(),
+			$context->getGenerator(),
+			$this->chunkX,
+			$this->chunkZ,
+			$chunk,
+			$chunks
+		);
 
 		$this->chunk = FastChunkSerializer::serializeTerrain($chunk);
 
@@ -118,18 +108,6 @@ class PopulationTask extends AsyncTask{
 		$this->adjacentChunks = igbinary_serialize($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{
 		/**
 		 * @var \Closure $onCompletion
diff --git a/src/world/generator/PopulationUtils.php b/src/world/generator/PopulationUtils.php
new file mode 100644
index 000000000..84840ee3e
--- /dev/null
+++ b/src/world/generator/PopulationUtils.php
@@ -0,0 +1,74 @@
+<?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\utils\AssumptionFailedError;
+use pocketmine\world\format\Chunk;
+use pocketmine\world\SimpleChunkManager;
+use pocketmine\world\World;
+
+/**
+ * @internal
+ */
+final class PopulationUtils{
+
+	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;
+	}
+
+	/**
+	 * @param Chunk[]|null[] $adjacentChunks
+	 * @phpstan-param array<int, Chunk|null> $adjacentChunks
+	 *
+	 * @return Chunk[]|Chunk[][]
+	 * @phpstan-return array{Chunk, array<int, Chunk>}
+	 */
+	public static function populateChunkWithAdjacents(int $minY, int $maxY, Generator $generator, int $chunkX, int $chunkZ, ?Chunk $centerChunk, array $adjacentChunks) : array{
+		$manager = new SimpleChunkManager($minY, $maxY);
+		self::setOrGenerateChunk($manager, $generator, $chunkX, $chunkZ, $centerChunk);
+
+		$resultChunks = []; //this is just to keep phpstan's type inference happy
+		foreach($adjacentChunks as $relativeChunkHash => $c){
+			World::getXZ($relativeChunkHash, $relativeX, $relativeZ);
+			$resultChunks[$relativeChunkHash] = self::setOrGenerateChunk($manager, $generator, $chunkX + $relativeX, $chunkZ + $relativeZ, $c);
+		}
+		$adjacentChunks = $resultChunks;
+
+		$generator->populateChunk($manager, $chunkX, $chunkZ);
+		$centerChunk = $manager->getChunk($chunkX, $chunkZ);
+		if($centerChunk === null){
+			throw new AssumptionFailedError("We just generated this chunk, so it must exist");
+		}
+		$centerChunk->setPopulated();
+		return [$centerChunk, $adjacentChunks];
+	}
+}