do not mess with cached data directly in packets

src/network/mcpe/StaticPacketCache.php

@@ -0,0 +1,69 @@
+<?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\network\mcpe;
+
+use pocketmine\network\mcpe\protocol\AvailableActorIdentifiersPacket;
+use pocketmine\network\mcpe\protocol\BiomeDefinitionListPacket;
+use pocketmine\network\mcpe\protocol\serializer\NetworkNbtSerializer;
+use pocketmine\network\mcpe\protocol\types\CacheableNbt;
+use pocketmine\utils\SingletonTrait;
+use function file_get_contents;
+
+class StaticPacketCache{
+	use SingletonTrait;
+
+	/** @var BiomeDefinitionListPacket */
+	private $biomeDefs;
+	/** @var AvailableActorIdentifiersPacket */
+	private $availableActorIdentifiers;
+
+	/**
+	 * @phpstan-return CacheableNbt<\pocketmine\nbt\tag\CompoundTag>
+	 */
+	private static function loadCompoundFromFile(string $filePath) : CacheableNbt{
+		$rawNbt = @file_get_contents($filePath);
+		if($rawNbt === false) throw new \RuntimeException("Failed to read file");
+		return new CacheableNbt((new NetworkNbtSerializer())->read($rawNbt)->mustGetCompoundTag());
+	}
+
+	private static function make() : self{
+		return new self(
+			BiomeDefinitionListPacket::create(self::loadCompoundFromFile(\pocketmine\RESOURCE_PATH . '/vanilla/biome_definitions.nbt')),
+			AvailableActorIdentifiersPacket::create(self::loadCompoundFromFile(\pocketmine\RESOURCE_PATH . '/vanilla/entity_identifiers.nbt'))
+		);
+	}
+
+	public function __construct(BiomeDefinitionListPacket $biomeDefs, AvailableActorIdentifiersPacket $availableActorIdentifiers){
+		$this->biomeDefs = $biomeDefs;
+		$this->availableActorIdentifiers = $availableActorIdentifiers;
+	}
+
+	public function getBiomeDefs() : BiomeDefinitionListPacket{
+		return $this->biomeDefs;
+	}
+
+	public function getAvailableActorIdentifiers() : AvailableActorIdentifiersPacket{
+		return $this->availableActorIdentifiers;
+	}
+}

src/network/mcpe/handler/PreSpawnPacketHandler.php

@@ -25,12 +25,11 @@ namespace pocketmine\network\mcpe\handler;
 
 use pocketmine\network\mcpe\convert\RuntimeBlockMapping;
 use pocketmine\network\mcpe\NetworkSession;
-use pocketmine\network\mcpe\protocol\AvailableActorIdentifiersPacket;
-use pocketmine\network\mcpe\protocol\BiomeDefinitionListPacket;
 use pocketmine\network\mcpe\protocol\RequestChunkRadiusPacket;
 use pocketmine\network\mcpe\protocol\SetLocalPlayerAsInitializedPacket;
 use pocketmine\network\mcpe\protocol\StartGamePacket;
 use pocketmine\network\mcpe\protocol\types\DimensionIds;
+use pocketmine\network\mcpe\StaticPacketCache;
 use pocketmine\player\Player;
 use pocketmine\Server;
 
@@ -82,8 +81,8 @@ class PreSpawnPacketHandler extends PacketHandler{
 
 		$this->session->sendDataPacket($pk);
 
-		$this->session->sendDataPacket(new AvailableActorIdentifiersPacket());
+		$this->session->sendDataPacket(StaticPacketCache::getInstance()->getAvailableActorIdentifiers());
-		$this->session->sendDataPacket(new BiomeDefinitionListPacket());
+		$this->session->sendDataPacket(StaticPacketCache::getInstance()->getBiomeDefs());
 
 		$this->player->setImmobile(); //HACK: fix client-side falling pre-spawn
 

src/network/mcpe/protocol/AvailableActorIdentifiersPacket.php

@@ -25,28 +25,41 @@ namespace pocketmine\network\mcpe\protocol;
 
 #include <rules/DataPacket.h>
 
+use pocketmine\nbt\NbtDataException;
 use pocketmine\network\mcpe\protocol\serializer\NetworkBinaryStream;
-use function file_get_contents;
+use pocketmine\network\mcpe\protocol\serializer\NetworkNbtSerializer;
+use pocketmine\network\mcpe\protocol\types\CacheableNbt;
 
 class AvailableActorIdentifiersPacket extends DataPacket implements ClientboundPacket{
 	public const NETWORK_ID = ProtocolInfo::AVAILABLE_ACTOR_IDENTIFIERS_PACKET;
 
-	/** @var string|null */
+	/**
-	private static $DEFAULT_NBT_CACHE = null;
+	 * @var CacheableNbt
+	 * @phpstan-var CacheableNbt<\pocketmine\nbt\tag\CompoundTag>
+	 */
+	public $identifiers;
 
-	/** @var string */
+	/**
-	public $namedtag;
+	 * @phpstan-param CacheableNbt<\pocketmine\nbt\tag\CompoundTag> $nbt
+	 */
+	public static function create(CacheableNbt $nbt) : self{
+		$result = new self;
+		$result->identifiers = $nbt;
+		return $result;
+	}
 
 	protected function decodePayload(NetworkBinaryStream $in) : void{
-		$this->namedtag = $in->getRemaining();
+		$offset = $in->getOffset();
+		try{
+			$this->identifiers = new CacheableNbt((new NetworkNbtSerializer())->read($in->getBuffer(), $offset)->mustGetCompoundTag());
+		}catch(NbtDataException $e){
+			throw PacketDecodeException::wrap($e, "Failed decoding actor identifiers");
+		}
+		$in->setOffset($offset);
 	}
 
 	protected function encodePayload(NetworkBinaryStream $out) : void{
-		$out->put(
+		$out->put($this->identifiers->getEncodedNbt());
-			$this->namedtag ??
-			self::$DEFAULT_NBT_CACHE ??
-			(self::$DEFAULT_NBT_CACHE = file_get_contents(\pocketmine\RESOURCE_PATH . '/vanilla/entity_identifiers.nbt'))
-		);
 	}
 
 	public function handle(PacketHandlerInterface $handler) : bool{

src/network/mcpe/protocol/BiomeDefinitionListPacket.php

@@ -25,28 +25,41 @@ namespace pocketmine\network\mcpe\protocol;
 
 #include <rules/DataPacket.h>
 
+use pocketmine\nbt\NbtDataException;
 use pocketmine\network\mcpe\protocol\serializer\NetworkBinaryStream;
-use function file_get_contents;
+use pocketmine\network\mcpe\protocol\serializer\NetworkNbtSerializer;
+use pocketmine\network\mcpe\protocol\types\CacheableNbt;
 
 class BiomeDefinitionListPacket extends DataPacket implements ClientboundPacket{
 	public const NETWORK_ID = ProtocolInfo::BIOME_DEFINITION_LIST_PACKET;
 
-	/** @var string|null */
+	/**
-	private static $DEFAULT_NBT_CACHE = null;
+	 * @var CacheableNbt
+	 * @phpstan-var CacheableNbt<\pocketmine\nbt\tag\CompoundTag>
+	 */
+	public $defs;
 
-	/** @var string */
+	/**
-	public $namedtag;
+	 * @phpstan-param CacheableNbt<\pocketmine\nbt\tag\CompoundTag> $nbt
+	 */
+	public static function create(CacheableNbt $nbt) : self{
+		$result = new self;
+		$result->defs = $nbt;
+		return $result;
+	}
 
 	protected function decodePayload(NetworkBinaryStream $in) : void{
-		$this->namedtag = $in->getRemaining();
+		$offset = $in->getOffset();
+		try{
+			$this->defs = new CacheableNbt((new NetworkNbtSerializer())->read($in->getBuffer(), $offset)->mustGetCompoundTag());
+		}catch(NbtDataException $e){
+			throw PacketDecodeException::wrap($e, "Failed decoding biome definitions");
+		}
+		$in->setOffset($offset);
 	}
 
 	protected function encodePayload(NetworkBinaryStream $out) : void{
-		$out->put(
+		$out->put($this->defs->getEncodedNbt());
-			$this->namedtag ??
-			self::$DEFAULT_NBT_CACHE ??
-			(self::$DEFAULT_NBT_CACHE = file_get_contents(\pocketmine\RESOURCE_PATH . '/vanilla/biome_definitions.nbt'))
-		);
 	}
 
 	public function handle(PacketHandlerInterface $handler) : bool{