PacketBatch.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 pmmp\encoding\ByteBufferReader;
use pmmp\encoding\ByteBufferWriter;
use pmmp\encoding\DataDecodeException;
use pmmp\encoding\VarInt;
use pocketmine\network\mcpe\protocol\Packet;
use pocketmine\network\mcpe\protocol\PacketDecodeException;
use pocketmine\network\mcpe\protocol\PacketPool;
use function strlen;
 
class PacketBatch{
 
    private function __construct(){
        //NOOP
    }
 
    final public static function decodeRaw(ByteBufferReader $in) : \Generator{
        $c = 0;
        while($in->getUnreadLength() > 0){
            try{
                $length = VarInt::readUnsignedInt($in);
                $buffer = $in->readByteArray($length);
            }catch(DataDecodeException $e){
                throw new PacketDecodeException("Error decoding packet $c in batch: " . $e->getMessage(), 0, $e);
            }
            yield $buffer;
            $c++;
        }
    }
 
    final public static function encodeRaw(ByteBufferWriter $out, array $packets) : void{
        foreach($packets as $packet){
            VarInt::writeUnsignedInt($out, strlen($packet));
            $out->writeByteArray($packet);
        }
    }
 
    final public static function decodePackets(ByteBufferReader $in, PacketPool $packetPool) : \Generator{
        $c = 0;
        foreach(self::decodeRaw($in) as $packetBuffer){
            $packet = $packetPool->getPacket($packetBuffer);
            if($packet !== null){
                try{
                    //TODO: this could use a view with a start and end offset to avoid extra string allocations
                    //currently ByteBufferReader doesn't support this
                    $packet->decode(new ByteBufferReader($packetBuffer));
                }catch(PacketDecodeException $e){
                    throw new PacketDecodeException("Error decoding packet $c in batch: " . $e->getMessage(), 0, $e);
                }
                yield $packet;
            }else{
                throw new PacketDecodeException("Unknown packet $c in batch");
            }
            $c++;
        }
    }
 
    final public static function encodePackets(ByteBufferWriter $out, array $packets) : void{
        foreach($packets as $packet){
            $serializer = new ByteBufferWriter();
            $packet->encode($serializer);
            //this may require a copy, so don't call it twice
            $packetBuffer = $serializer->getData();
            VarInt::writeUnsignedInt($out, strlen($packetBuffer));
            $out->writeByteArray($packetBuffer);
        }
    }
}