bedrock-protocol/src/serializer/PacketSerializer.php

<?php
 
/*
 * This file is part of BedrockProtocol.
 * Copyright (C) 2014-2022 PocketMine Team <https://github.com/pmmp/BedrockProtocol>
 *
 * BedrockProtocol 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.
 */
 
declare(strict_types=1);
 
namespace pocketmine\network\mcpe\protocol\serializer;
 
use pocketmine\math\Vector3;
use pocketmine\nbt\NbtDataException;
use pocketmine\nbt\tag\CompoundTag;
use pocketmine\nbt\TreeRoot;
use pocketmine\network\mcpe\protocol\PacketDecodeException;
use pocketmine\network\mcpe\protocol\types\BlockPosition;
use pocketmine\network\mcpe\protocol\types\BoolGameRule;
use pocketmine\network\mcpe\protocol\types\command\CommandOriginData;
use pocketmine\network\mcpe\protocol\types\entity\Attribute;
use pocketmine\network\mcpe\protocol\types\entity\AttributeModifier;
use pocketmine\network\mcpe\protocol\types\entity\BlockPosMetadataProperty;
use pocketmine\network\mcpe\protocol\types\entity\ByteMetadataProperty;
use pocketmine\network\mcpe\protocol\types\entity\CompoundTagMetadataProperty;
use pocketmine\network\mcpe\protocol\types\entity\EntityLink;
use pocketmine\network\mcpe\protocol\types\entity\FloatMetadataProperty;
use pocketmine\network\mcpe\protocol\types\entity\IntMetadataProperty;
use pocketmine\network\mcpe\protocol\types\entity\LongMetadataProperty;
use pocketmine\network\mcpe\protocol\types\entity\MetadataProperty;
use pocketmine\network\mcpe\protocol\types\entity\ShortMetadataProperty;
use pocketmine\network\mcpe\protocol\types\entity\StringMetadataProperty;
use pocketmine\network\mcpe\protocol\types\entity\Vec3MetadataProperty;
use pocketmine\network\mcpe\protocol\types\FloatGameRule;
use pocketmine\network\mcpe\protocol\types\GameRule;
use pocketmine\network\mcpe\protocol\types\IntGameRule;
use pocketmine\network\mcpe\protocol\types\inventory\ItemStack;
use pocketmine\network\mcpe\protocol\types\inventory\ItemStackWrapper;
use pocketmine\network\mcpe\protocol\types\recipe\ComplexAliasItemDescriptor;
use pocketmine\network\mcpe\protocol\types\recipe\IntIdMetaItemDescriptor;
use pocketmine\network\mcpe\protocol\types\recipe\ItemDescriptorType;
use pocketmine\network\mcpe\protocol\types\recipe\MolangItemDescriptor;
use pocketmine\network\mcpe\protocol\types\recipe\RecipeIngredient;
use pocketmine\network\mcpe\protocol\types\recipe\StringIdMetaItemDescriptor;
use pocketmine\network\mcpe\protocol\types\recipe\TagItemDescriptor;
use pocketmine\network\mcpe\protocol\types\skin\PersonaPieceTintColor;
use pocketmine\network\mcpe\protocol\types\skin\PersonaSkinPiece;
use pocketmine\network\mcpe\protocol\types\skin\SkinAnimation;
use pocketmine\network\mcpe\protocol\types\skin\SkinData;
use pocketmine\network\mcpe\protocol\types\skin\SkinImage;
use pocketmine\network\mcpe\protocol\types\StructureEditorData;
use pocketmine\network\mcpe\protocol\types\StructureSettings;
use pocketmine\utils\Binary;
use pocketmine\utils\BinaryDataException;
use pocketmine\utils\BinaryStream;
use Ramsey\Uuid\Uuid;
use Ramsey\Uuid\UuidInterface;
use function count;
use function strlen;
use function strrev;
use function substr;
 
class PacketSerializer extends BinaryStream{
    protected function __construct(string $buffer = "", int $offset = 0){
        //overridden to change visibility
        parent::__construct($buffer, $offset);
    }
 
    public static function encoder() : self{
        return new self();
    }
 
    public static function decoder(string $buffer, int $offset) : self{
        return new self($buffer, $offset);
    }
 
    public function getString() : string{
        return $this->get($this->getUnsignedVarInt());
    }
 
    public function putString(string $v) : void{
        $this->putUnsignedVarInt(strlen($v));
        $this->put($v);
    }
 
    public function getUUID() : UuidInterface{
        //This is two little-endian longs: bytes 7-0 followed by bytes 15-8
        $p1 = strrev($this->get(8));
        $p2 = strrev($this->get(8));
        return Uuid::fromBytes($p1 . $p2);
    }
 
    public function putUUID(UuidInterface $uuid) : void{
        $bytes = $uuid->getBytes();
        $this->put(strrev(substr($bytes, 0, 8)));
        $this->put(strrev(substr($bytes, 8, 8)));
    }
 
    public function getSkin() : SkinData{
        $skinId = $this->getString();
        $skinPlayFabId = $this->getString();
        $skinResourcePatch = $this->getString();
        $skinData = $this->getSkinImage();
        $animationCount = $this->getLInt();
        $animations = [];
        for($i = 0; $i < $animationCount; ++$i){
            $skinImage = $this->getSkinImage();
            $animationType = $this->getLInt();
            $animationFrames = $this->getLFloat();
            $expressionType = $this->getLInt();
            $animations[] = new SkinAnimation($skinImage, $animationType, $animationFrames, $expressionType);
        }
        $capeData = $this->getSkinImage();
        $geometryData = $this->getString();
        $geometryDataVersion = $this->getString();
        $animationData = $this->getString();
        $capeId = $this->getString();
        $fullSkinId = $this->getString();
        $armSize = $this->getString();
        $skinColor = $this->getString();
        $personaPieceCount = $this->getLInt();
        $personaPieces = [];
        for($i = 0; $i < $personaPieceCount; ++$i){
            $pieceId = $this->getString();
            $pieceType = $this->getString();
            $packId = $this->getString();
            $isDefaultPiece = $this->getBool();
            $productId = $this->getString();
            $personaPieces[] = new PersonaSkinPiece($pieceId, $pieceType, $packId, $isDefaultPiece, $productId);
        }
        $pieceTintColorCount = $this->getLInt();
        $pieceTintColors = [];
        for($i = 0; $i < $pieceTintColorCount; ++$i){
            $pieceType = $this->getString();
            $colorCount = $this->getLInt();
            $colors = [];
            for($j = 0; $j < $colorCount; ++$j){
                $colors[] = $this->getString();
            }
            $pieceTintColors[] = new PersonaPieceTintColor(
                $pieceType,
                $colors
            );
        }
 
        $premium = $this->getBool();
        $persona = $this->getBool();
        $capeOnClassic = $this->getBool();
        $isPrimaryUser = $this->getBool();
        $override = $this->getBool();
 
        return new SkinData(
            $skinId,
            $skinPlayFabId,
            $skinResourcePatch,
            $skinData,
            $animations,
            $capeData,
            $geometryData,
            $geometryDataVersion,
            $animationData,
            $capeId,
            $fullSkinId,
            $armSize,
            $skinColor,
            $personaPieces,
            $pieceTintColors,
            true,
            $premium,
            $persona,
            $capeOnClassic,
            $isPrimaryUser,
            $override,
        );
    }
 
    public function putSkin(SkinData $skin) : void{
        $this->putString($skin->getSkinId());
        $this->putString($skin->getPlayFabId());
        $this->putString($skin->getResourcePatch());
        $this->putSkinImage($skin->getSkinImage());
        $this->putLInt(count($skin->getAnimations()));
        foreach($skin->getAnimations() as $animation){
            $this->putSkinImage($animation->getImage());
            $this->putLInt($animation->getType());
            $this->putLFloat($animation->getFrames());
            $this->putLInt($animation->getExpressionType());
        }
        $this->putSkinImage($skin->getCapeImage());
        $this->putString($skin->getGeometryData());
        $this->putString($skin->getGeometryDataEngineVersion());
        $this->putString($skin->getAnimationData());
        $this->putString($skin->getCapeId());
        $this->putString($skin->getFullSkinId());
        $this->putString($skin->getArmSize());
        $this->putString($skin->getSkinColor());
        $this->putLInt(count($skin->getPersonaPieces()));
        foreach($skin->getPersonaPieces() as $piece){
            $this->putString($piece->getPieceId());
            $this->putString($piece->getPieceType());
            $this->putString($piece->getPackId());
            $this->putBool($piece->isDefaultPiece());
            $this->putString($piece->getProductId());
        }
        $this->putLInt(count($skin->getPieceTintColors()));
        foreach($skin->getPieceTintColors() as $tint){
            $this->putString($tint->getPieceType());
            $this->putLInt(count($tint->getColors()));
            foreach($tint->getColors() as $color){
                $this->putString($color);
            }
        }
        $this->putBool($skin->isPremium());
        $this->putBool($skin->isPersona());
        $this->putBool($skin->isPersonaCapeOnClassic());
        $this->putBool($skin->isPrimaryUser());
        $this->putBool($skin->isOverride());
    }
 
    private function getSkinImage() : SkinImage{
        $width = $this->getLInt();
        $height = $this->getLInt();
        $data = $this->getString();
        try{
            return new SkinImage($height, $width, $data);
        }catch(\InvalidArgumentException $e){
            throw new PacketDecodeException($e->getMessage(), 0, $e);
        }
    }
 
    private function putSkinImage(SkinImage $image) : void{
        $this->putLInt($image->getWidth());
        $this->putLInt($image->getHeight());
        $this->putString($image->getData());
    }
 
    private function getItemStackHeader() : array{
        $id = $this->getVarInt();
        if($id === 0){
            return [0, 0, 0];
        }
 
        $count = $this->getLShort();
        $meta = $this->getUnsignedVarInt();
 
        return [$id, $count, $meta];
    }
 
    private function putItemStackHeader(ItemStack $itemStack) : bool{
        if($itemStack->getId() === 0){
            $this->putVarInt(0);
            return false;
        }
 
        $this->putVarInt($itemStack->getId());
        $this->putLShort($itemStack->getCount());
        $this->putUnsignedVarInt($itemStack->getMeta());
 
        return true;
    }
 
    private function getItemStackFooter(int $id, int $meta, int $count) : ItemStack{
        $blockRuntimeId = $this->getVarInt();
        $rawExtraData = $this->getString();
 
        return new ItemStack($id, $meta, $count, $blockRuntimeId, $rawExtraData);
    }
 
    private function putItemStackFooter(ItemStack $itemStack) : void{
        $this->putVarInt($itemStack->getBlockRuntimeId());
        $this->putString($itemStack->getRawExtraData());
    }
 
    public function getItemStackWithoutStackId() : ItemStack{
        [$id, $count, $meta] = $this->getItemStackHeader();
 
        return $id !== 0 ? $this->getItemStackFooter($id, $meta, $count) : ItemStack::null();
 
    }
 
    public function putItemStackWithoutStackId(ItemStack $itemStack) : void{
        if($this->putItemStackHeader($itemStack)){
            $this->putItemStackFooter($itemStack);
        }
    }
 
    public function getItemStackWrapper() : ItemStackWrapper{
        [$id, $count, $meta] = $this->getItemStackHeader();
        if($id === 0){
            return new ItemStackWrapper(0, ItemStack::null());
        }
 
        $hasNetId = $this->getBool();
        $stackId = $hasNetId ? $this->readServerItemStackId() : 0;
 
        $itemStack = $this->getItemStackFooter($id, $meta, $count);
 
        return new ItemStackWrapper($stackId, $itemStack);
    }
 
    public function putItemStackWrapper(ItemStackWrapper $itemStackWrapper) : void{
        $itemStack = $itemStackWrapper->getItemStack();
        if($this->putItemStackHeader($itemStack)){
            $hasNetId = $itemStackWrapper->getStackId() !== 0;
            $this->putBool($hasNetId);
            if($hasNetId){
                $this->writeServerItemStackId($itemStackWrapper->getStackId());
            }
 
            $this->putItemStackFooter($itemStack);
        }
    }
 
    public function getRecipeIngredient() : RecipeIngredient{
        $descriptorType = $this->getByte();
        $descriptor = match($descriptorType){
            ItemDescriptorType::INT_ID_META => IntIdMetaItemDescriptor::read($this),
            ItemDescriptorType::STRING_ID_META => StringIdMetaItemDescriptor::read($this),
            ItemDescriptorType::TAG => TagItemDescriptor::read($this),
            ItemDescriptorType::MOLANG => MolangItemDescriptor::read($this),
            ItemDescriptorType::COMPLEX_ALIAS => ComplexAliasItemDescriptor::read($this),
            default => null
        };
        $count = $this->getVarInt();
 
        return new RecipeIngredient($descriptor, $count);
    }
 
    public function putRecipeIngredient(RecipeIngredient $ingredient) : void{
        $type = $ingredient->getDescriptor();
 
        $this->putByte($type?->getTypeId() ?? 0);
        $type?->write($this);
 
        $this->putVarInt($ingredient->getCount());
    }
 
    public function getEntityMetadata() : array{
        $count = $this->getUnsignedVarInt();
        $data = [];
        for($i = 0; $i < $count; ++$i){
            $key = $this->getUnsignedVarInt();
            $type = $this->getUnsignedVarInt();
 
            $data[$key] = $this->readMetadataProperty($type);
        }
 
        return $data;
    }
 
    private function readMetadataProperty(int $type) : MetadataProperty{
        return match($type){
            ByteMetadataProperty::ID => ByteMetadataProperty::read($this),
            ShortMetadataProperty::ID => ShortMetadataProperty::read($this),
            IntMetadataProperty::ID => IntMetadataProperty::read($this),
            FloatMetadataProperty::ID => FloatMetadataProperty::read($this),
            StringMetadataProperty::ID => StringMetadataProperty::read($this),
            CompoundTagMetadataProperty::ID => CompoundTagMetadataProperty::read($this),
            BlockPosMetadataProperty::ID => BlockPosMetadataProperty::read($this),
            LongMetadataProperty::ID => LongMetadataProperty::read($this),
            Vec3MetadataProperty::ID => Vec3MetadataProperty::read($this),
            default => throw new PacketDecodeException("Unknown entity metadata type " . $type),
        };
    }
 
    public function putEntityMetadata(array $metadata) : void{
        $this->putUnsignedVarInt(count($metadata));
        foreach($metadata as $key => $d){
            $this->putUnsignedVarInt($key);
            $this->putUnsignedVarInt($d->getTypeId());
            $d->write($this);
        }
    }
 
    public function getAttributeList() : array{
        $list = [];
        $count = $this->getUnsignedVarInt();
 
        for($i = 0; $i < $count; ++$i){
            $min = $this->getLFloat();
            $max = $this->getLFloat();
            $current = $this->getLFloat();
            $default = $this->getLFloat();
            $id = $this->getString();
 
            $modifiers = [];
            for($j = 0, $modifierCount = $this->getUnsignedVarInt(); $j < $modifierCount; $j++){
                $modifiers[] = AttributeModifier::read($this);
            }
 
            $list[] = new Attribute($id, $min, $max, $current, $default, $modifiers);
        }
 
        return $list;
    }
 
    public function putAttributeList(Attribute ...$attributes) : void{
        $this->putUnsignedVarInt(count($attributes));
        foreach($attributes as $attribute){
            $this->putLFloat($attribute->getMin());
            $this->putLFloat($attribute->getMax());
            $this->putLFloat($attribute->getCurrent());
            $this->putLFloat($attribute->getDefault());
            $this->putString($attribute->getId());
 
            $this->putUnsignedVarInt(count($attribute->getModifiers()));
            foreach($attribute->getModifiers() as $modifier){
                $modifier->write($this);
            }
        }
    }
 
    final public function getActorUniqueId() : int{
        return $this->getVarLong();
    }
 
    public function putActorUniqueId(int $eid) : void{
        $this->putVarLong($eid);
    }
 
    final public function getActorRuntimeId() : int{
        return $this->getUnsignedVarLong();
    }
 
    public function putActorRuntimeId(int $eid) : void{
        $this->putUnsignedVarLong($eid);
    }
 
    public function getBlockPosition() : BlockPosition{
        $x = $this->getVarInt();
        $y = Binary::signInt($this->getUnsignedVarInt()); //Y coordinate may be signed, but it's written unsigned :<
        $z = $this->getVarInt();
        return new BlockPosition($x, $y, $z);
    }
 
    public function putBlockPosition(BlockPosition $blockPosition) : void{
        $this->putVarInt($blockPosition->getX());
        $this->putUnsignedVarInt(Binary::unsignInt($blockPosition->getY())); //Y coordinate may be signed, but it's written unsigned :<
        $this->putVarInt($blockPosition->getZ());
    }
 
    public function getSignedBlockPosition() : BlockPosition{
        $x = $this->getVarInt();
        $y = $this->getVarInt();
        $z = $this->getVarInt();
        return new BlockPosition($x, $y, $z);
    }
 
    public function putSignedBlockPosition(BlockPosition $blockPosition) : void{
        $this->putVarInt($blockPosition->getX());
        $this->putVarInt($blockPosition->getY());
        $this->putVarInt($blockPosition->getZ());
    }
 
    public function getVector3() : Vector3{
        $x = $this->getLFloat();
        $y = $this->getLFloat();
        $z = $this->getLFloat();
        return new Vector3($x, $y, $z);
    }
 
    public function putVector3Nullable(?Vector3 $vector) : void{
        if($vector !== null){
            $this->putVector3($vector);
        }else{
            $this->putLFloat(0.0);
            $this->putLFloat(0.0);
            $this->putLFloat(0.0);
        }
    }
 
    public function putVector3(Vector3 $vector) : void{
        $this->putLFloat($vector->x);
        $this->putLFloat($vector->y);
        $this->putLFloat($vector->z);
    }
 
    public function getRotationByte() : float{
        return ($this->getByte() * (360 / 256));
    }
 
    public function putRotationByte(float $rotation) : void{
        $this->putByte((int) ($rotation / (360 / 256)));
    }
 
    private function readGameRule(int $type, bool $isPlayerModifiable) : GameRule{
        return match($type){
            BoolGameRule::ID => BoolGameRule::decode($this, $isPlayerModifiable),
            IntGameRule::ID => IntGameRule::decode($this, $isPlayerModifiable),
            FloatGameRule::ID => FloatGameRule::decode($this, $isPlayerModifiable),
            default => throw new PacketDecodeException("Unknown gamerule type $type"),
        };
    }
 
    public function getGameRules() : array{
        $count = $this->getUnsignedVarInt();
        $rules = [];
        for($i = 0; $i < $count; ++$i){
            $name = $this->getString();
            $isPlayerModifiable = $this->getBool();
            $type = $this->getUnsignedVarInt();
            $rules[$name] = $this->readGameRule($type, $isPlayerModifiable);
        }
 
        return $rules;
    }
 
    public function putGameRules(array $rules) : void{
        $this->putUnsignedVarInt(count($rules));
        foreach($rules as $name => $rule){
            $this->putString($name);
            $this->putBool($rule->isPlayerModifiable());
            $this->putUnsignedVarInt($rule->getTypeId());
            $rule->encode($this);
        }
    }
 
    public function getEntityLink() : EntityLink{
        $fromActorUniqueId = $this->getActorUniqueId();
        $toActorUniqueId = $this->getActorUniqueId();
        $type = $this->getByte();
        $immediate = $this->getBool();
        $causedByRider = $this->getBool();
        return new EntityLink($fromActorUniqueId, $toActorUniqueId, $type, $immediate, $causedByRider);
    }
 
    public function putEntityLink(EntityLink $link) : void{
        $this->putActorUniqueId($link->fromActorUniqueId);
        $this->putActorUniqueId($link->toActorUniqueId);
        $this->putByte($link->type);
        $this->putBool($link->immediate);
        $this->putBool($link->causedByRider);
    }
 
    public function getCommandOriginData() : CommandOriginData{
        $result = new CommandOriginData();
 
        $result->type = $this->getUnsignedVarInt();
        $result->uuid = $this->getUUID();
        $result->requestId = $this->getString();
 
        if($result->type === CommandOriginData::ORIGIN_DEV_CONSOLE or $result->type === CommandOriginData::ORIGIN_TEST){
            $result->playerActorUniqueId = $this->getVarLong();
        }
 
        return $result;
    }
 
    public function putCommandOriginData(CommandOriginData $data) : void{
        $this->putUnsignedVarInt($data->type);
        $this->putUUID($data->uuid);
        $this->putString($data->requestId);
 
        if($data->type === CommandOriginData::ORIGIN_DEV_CONSOLE or $data->type === CommandOriginData::ORIGIN_TEST){
            $this->putVarLong($data->playerActorUniqueId);
        }
    }
 
    public function getStructureSettings() : StructureSettings{
        $result = new StructureSettings();
 
        $result->paletteName = $this->getString();
 
        $result->ignoreEntities = $this->getBool();
        $result->ignoreBlocks = $this->getBool();
        $result->allowNonTickingChunks = $this->getBool();
 
        $result->dimensions = $this->getBlockPosition();
        $result->offset = $this->getBlockPosition();
 
        $result->lastTouchedByPlayerID = $this->getActorUniqueId();
        $result->rotation = $this->getByte();
        $result->mirror = $this->getByte();
        $result->animationMode = $this->getByte();
        $result->animationSeconds = $this->getLFloat();
        $result->integrityValue = $this->getLFloat();
        $result->integritySeed = $this->getLInt();
        $result->pivot = $this->getVector3();
 
        return $result;
    }
 
    public function putStructureSettings(StructureSettings $structureSettings) : void{
        $this->putString($structureSettings->paletteName);
 
        $this->putBool($structureSettings->ignoreEntities);
        $this->putBool($structureSettings->ignoreBlocks);
        $this->putBool($structureSettings->allowNonTickingChunks);
 
        $this->putBlockPosition($structureSettings->dimensions);
        $this->putBlockPosition($structureSettings->offset);
 
        $this->putActorUniqueId($structureSettings->lastTouchedByPlayerID);
        $this->putByte($structureSettings->rotation);
        $this->putByte($structureSettings->mirror);
        $this->putByte($structureSettings->animationMode);
        $this->putLFloat($structureSettings->animationSeconds);
        $this->putLFloat($structureSettings->integrityValue);
        $this->putLInt($structureSettings->integritySeed);
        $this->putVector3($structureSettings->pivot);
    }
 
    public function getStructureEditorData() : StructureEditorData{
        $result = new StructureEditorData();
 
        $result->structureName = $this->getString();
        $result->structureDataField = $this->getString();
 
        $result->includePlayers = $this->getBool();
        $result->showBoundingBox = $this->getBool();
 
        $result->structureBlockType = $this->getVarInt();
        $result->structureSettings = $this->getStructureSettings();
        $result->structureRedstoneSaveMode = $this->getVarInt();
 
        return $result;
    }
 
    public function putStructureEditorData(StructureEditorData $structureEditorData) : void{
        $this->putString($structureEditorData->structureName);
        $this->putString($structureEditorData->structureDataField);
 
        $this->putBool($structureEditorData->includePlayers);
        $this->putBool($structureEditorData->showBoundingBox);
 
        $this->putVarInt($structureEditorData->structureBlockType);
        $this->putStructureSettings($structureEditorData->structureSettings);
        $this->putVarInt($structureEditorData->structureRedstoneSaveMode);
    }
 
    public function getNbtRoot() : TreeRoot{
        $offset = $this->getOffset();
        try{
            return (new NetworkNbtSerializer())->read($this->getBuffer(), $offset, 512);
        }catch(NbtDataException $e){
            throw PacketDecodeException::wrap($e, "Failed decoding NBT root");
        }finally{
            $this->setOffset($offset);
        }
    }
 
    public function getNbtCompoundRoot() : CompoundTag{
        try{
            return $this->getNbtRoot()->mustGetCompoundTag();
        }catch(NbtDataException $e){
            throw PacketDecodeException::wrap($e, "Expected TAG_Compound NBT root");
        }
    }
 
    public function readRecipeNetId() : int{
        return $this->getUnsignedVarInt();
    }
 
    public function writeRecipeNetId(int $id) : void{
        $this->putUnsignedVarInt($id);
    }
 
    public function readCreativeItemNetId() : int{
        return $this->getUnsignedVarInt();
    }
 
    public function writeCreativeItemNetId(int $id) : void{
        $this->putUnsignedVarInt($id);
    }
 
    public function readItemStackNetIdVariant() : int{
        return $this->getVarInt();
    }
 
    public function writeItemStackNetIdVariant(int $id) : void{
        $this->putVarInt($id);
    }
 
    public function readItemStackRequestId() : int{
        return $this->getVarInt();
    }
 
    public function writeItemStackRequestId(int $id) : void{
        $this->putVarInt($id);
    }
 
    public function readLegacyItemStackRequestId() : int{
        return $this->getVarInt();
    }
 
    public function writeLegacyItemStackRequestId(int $id) : void{
        $this->putVarInt($id);
    }
 
    public function readServerItemStackId() : int{
        return $this->getVarInt();
    }
 
    public function writeServerItemStackId(int $id) : void{
        $this->putVarInt($id);
    }
 
    public function readOptional(\Closure $reader) : mixed{
        if($this->getBool()){
            return $reader();
        }
        return null;
    }
 
    public function writeOptional(mixed $value, \Closure $writer) : void{
        if($value !== null){
            $this->putBool(true);
            $writer($value);
        }else{
            $this->putBool(false);
        }
    }
}