StandardPacketBroadcaster.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\network\mcpe;
 
use pmmp\encoding\ByteBufferWriter;
use pocketmine\event\server\DataPacketSendEvent;
use pocketmine\network\mcpe\protocol\serializer\PacketBatch;
use pocketmine\Server;
use pocketmine\timings\Timings;
use function count;
use function log;
use function spl_object_id;
use function strlen;
 
final class StandardPacketBroadcaster implements PacketBroadcaster{
    public function __construct(
        private Server $server
    ){}
 
    public function broadcastPackets(array $recipients, array $packets) : void{
        //TODO: this shouldn't really be called here, since the broadcaster might be replaced by an alternative
        //implementation that doesn't fire events
        if(DataPacketSendEvent::hasHandlers()){
            $ev = new DataPacketSendEvent($recipients, $packets);
            $ev->call();
            if($ev->isCancelled()){
                return;
            }
            $packets = $ev->getPackets();
        }
 
        $compressors = [];
 
        $targetsByCompressor = [];
        foreach($recipients as $recipient){
            //TODO: different compressors might be compatible, it might not be necessary to split them up by object
            $compressor = $recipient->getCompressor();
            $compressors[spl_object_id($compressor)] = $compressor;
 
            $targetsByCompressor[spl_object_id($compressor)][] = $recipient;
        }
 
        $totalLength = 0;
        $packetBuffers = [];
        $writer = new ByteBufferWriter();
        foreach($packets as $packet){
            $writer->clear(); //memory reuse let's gooooo
            $buffer = NetworkSession::encodePacketTimed($writer, $packet);
            //varint length prefix + packet buffer
            $totalLength += (((int) log(strlen($buffer), 128)) + 1) + strlen($buffer);
            $packetBuffers[] = $buffer;
        }
 
        foreach($targetsByCompressor as $compressorId => $compressorTargets){
            $compressor = $compressors[$compressorId];
 
            $threshold = $compressor->getCompressionThreshold();
            if(count($compressorTargets) > 1 && $threshold !== null && $totalLength >= $threshold){
                //do not prepare shared batch unless we're sure it will be compressed
                $stream = new ByteBufferWriter();
                PacketBatch::encodeRaw($stream, $packetBuffers);
                $batchBuffer = $stream->getData();
 
                $batch = $this->server->prepareBatch($batchBuffer, $compressor, timings: Timings::$playerNetworkSendCompressBroadcast);
                foreach($compressorTargets as $target){
                    $target->queueCompressed($batch);
                }
            }else{
                foreach($compressorTargets as $target){
                    foreach($packetBuffers as $packetBuffer){
                        $target->addToSendBuffer($packetBuffer);
                    }
                }
            }
        }
    }
}