RakLib: split PthreadsChannelWriter into two implementations

this gains a very small performance improvement by avoiding unnecessary !== null checks on every packet written in either direction. It's insignificant for sure, but I just found this code in an old stash, so what the heck.

src/network/mcpe/raklib/PthreadsChannelWriter.php

@@ -23,18 +23,12 @@ use raklib\server\ipc\InterThreadChannelWriter;
 final class PthreadsChannelWriter implements InterThreadChannelWriter{
 	/** @var \Threaded */
 	private $buffer;
-	/** @var SleeperNotifier|null */
-	private $notifier;
 
-	public function __construct(\Threaded $buffer, ?SleeperNotifier $notifier = null){
+	public function __construct(\Threaded $buffer){
 		$this->buffer = $buffer;
-		$this->notifier = $notifier;
 	}
 
 	public function write(string $str) : void{
 		$this->buffer[] = $str;
-		if($this->notifier !== null){
-			$this->notifier->wakeupSleeper();
-		}
 	}
 }

src/network/mcpe/raklib/RakLibServer.php

@@ -153,7 +153,7 @@ class RakLibServer extends Thread{
 				$this->maxMtuSize,
 				new SimpleProtocolAcceptor($this->protocolVersion),
 				new UserToRakLibThreadMessageReceiver(new PthreadsChannelReader($this->mainToThreadBuffer)),
-				new RakLibToUserThreadMessageSender(new PthreadsChannelWriter($this->threadToMainBuffer, $this->mainThreadNotifier)),
+				new RakLibToUserThreadMessageSender(new SnoozeAwarePthreadsChannelWriter($this->threadToMainBuffer, $this->mainThreadNotifier)),
 				new ExceptionTraceCleaner($this->mainPath)
 			);
 			$this->synchronized(function() : void{

src/network/mcpe/raklib/SnoozeAwarePthreadsChannelWriter.php

@@ -0,0 +1,42 @@
+<?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\raklib;
+
+use pocketmine\snooze\SleeperNotifier;
+use raklib\server\ipc\InterThreadChannelWriter;
+
+final class SnoozeAwarePthreadsChannelWriter implements InterThreadChannelWriter{
+	private \Threaded $buffer;
+	private SleeperNotifier $notifier;
+
+	public function __construct(\Threaded $buffer, SleeperNotifier $notifier){
+		$this->buffer = $buffer;
+		$this->notifier = $notifier;
+	}
+
+	public function write(string $str) : void{
+		$this->buffer[] = $str;
+		$this->notifier->wakeupSleeper();
+	}
+}