Extract a Packet interface from DataPacket

this is in preparation for clientbound/serverbound packet separation. I did this already on another branch, but the changeset was dependent on a massive refactor to split apart packets and binarystream which i'm still not fully happy with.

src/pocketmine/network/mcpe/NetworkSession.php

@@ -34,8 +34,8 @@ use pocketmine\network\mcpe\handler\PreSpawnSessionHandler;
 use pocketmine\network\mcpe\handler\ResourcePacksSessionHandler;
 use pocketmine\network\mcpe\handler\SessionHandler;
 use pocketmine\network\mcpe\handler\SimpleSessionHandler;
-use pocketmine\network\mcpe\protocol\DataPacket;
 use pocketmine\network\mcpe\protocol\DisconnectPacket;
+use pocketmine\network\mcpe\protocol\Packet;
 use pocketmine\network\mcpe\protocol\PacketPool;
 use pocketmine\network\mcpe\protocol\PlayStatusPacket;
 use pocketmine\network\mcpe\protocol\ServerToClientHandshakePacket;
@@ -209,11 +209,11 @@ class NetworkSession{
 	}
 
 	/**
-	 * @param DataPacket $packet
+	 * @param Packet $packet
 	 *
 	 * @throws BadPacketException
 	 */
-	public function handleDataPacket(DataPacket $packet) : void{
+	public function handleDataPacket(Packet $packet) : void{
 		$timings = Timings::getReceiveDataPacketTimings($packet);
 		$timings->startTiming();
 
@@ -237,7 +237,7 @@ class NetworkSession{
 		$timings->stopTiming();
 	}
 
-	public function sendDataPacket(DataPacket $packet, bool $immediate = false) : bool{
+	public function sendDataPacket(Packet $packet, bool $immediate = false) : bool{
 		$timings = Timings::getSendDataPacketTimings($packet);
 		$timings->startTiming();
 		try{
@@ -260,9 +260,9 @@ class NetworkSession{
 
 	/**
 	 * @internal
-	 * @param DataPacket $packet
+	 * @param Packet $packet
 	 */
-	public function addToSendBuffer(DataPacket $packet) : void{
+	public function addToSendBuffer(Packet $packet) : void{
 		$timings = Timings::getSendDataPacketTimings($packet);
 		$timings->startTiming();
 		try{

src/pocketmine/network/mcpe/PacketStream.php

@@ -23,19 +23,19 @@ declare(strict_types=1);
 
 namespace pocketmine\network\mcpe;
 
-use pocketmine\network\mcpe\protocol\DataPacket;
+use pocketmine\network\mcpe\protocol\Packet;
 use pocketmine\network\mcpe\protocol\PacketPool;
 
 class PacketStream extends NetworkBinaryStream{
 
-	public function putPacket(DataPacket $packet) : void{
-		if(!$packet->isEncoded){
+	public function putPacket(Packet $packet) : void{
+		if(!$packet->isEncoded()){
 			$packet->encode();
 		}
 		$this->putString($packet->getBuffer());
 	}
 
-	public function getPacket() : DataPacket{
+	public function getPacket() : Packet{
 		return PacketPool::getPacket($this->getString());
 	}
 }

src/pocketmine/network/mcpe/protocol/DataPacket.php

@@ -36,12 +36,12 @@ use function is_object;
 use function is_string;
 use function method_exists;
 
-abstract class DataPacket extends NetworkBinaryStream{
+abstract class DataPacket extends NetworkBinaryStream implements Packet{
 
 	public const NETWORK_ID = 0;
 
 	/** @var bool */
-	public $isEncoded = false;
+	private $isEncoded = false;
 
 	/** @var int */
 	public $senderSubId = 0;
@@ -108,6 +108,10 @@ abstract class DataPacket extends NetworkBinaryStream{
 		$this->isEncoded = true;
 	}
 
+	final public function isEncoded() : bool{
+		return $this->isEncoded;
+	}
+
 	protected function encodeHeader() : void{
 		$this->putUnsignedVarInt(static::NETWORK_ID);
 	}

src/pocketmine/network/mcpe/protocol/Packet.php

@@ -0,0 +1,82 @@
+<?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\protocol;
+
+use pocketmine\network\BadPacketException;
+use pocketmine\network\mcpe\handler\SessionHandler;
+
+interface Packet{
+
+	public function setOffset(int $offset) : void;
+
+	public function setBuffer(string $buffer = "", int $offset = 0);
+
+	public function getOffset() : int;
+
+	public function getBuffer() : string;
+
+	/**
+	 * Returns whether the offset has reached the end of the buffer.
+	 * @return bool
+	 */
+	public function feof() : bool;
+
+	public function pid() : int;
+
+	public function getName() : string;
+
+	public function canBeSentBeforeLogin() : bool;
+
+	/**
+	 * Returns whether the packet may legally have unread bytes left in the buffer.
+	 * @return bool
+	 */
+	public function mayHaveUnreadBytes() : bool;
+
+	/**
+	 * @throws BadPacketException
+	 */
+	public function decode() : void;
+
+	public function encode() : void;
+
+	public function isEncoded() : bool;
+
+	/**
+	 * Performs handling for this packet. Usually you'll want an appropriately named method in the session handler for
+	 * this.
+	 *
+	 * This method returns a bool to indicate whether the packet was handled or not. If the packet was unhandled, a
+	 * debug message will be logged with a hexdump of the packet.
+	 *
+	 * Typically this method returns the return value of the handler in the supplied SessionHandler. See other packets
+	 * for examples how to implement this.
+	 *
+	 * @param SessionHandler $handler
+	 *
+	 * @return bool true if the packet was handled successfully, false if not.
+	 * @throws BadPacketException if broken data was found in the packet
+	 */
+	public function handle(SessionHandler $handler) : bool;
+}

src/pocketmine/network/mcpe/protocol/PacketPool.php

@@ -28,7 +28,7 @@ use pocketmine\utils\Binary;
 use pocketmine\utils\BinaryDataException;
 
 class PacketPool{
-	/** @var \SplFixedArray<DataPacket> */
+	/** @var \SplFixedArray<Packet> */
 	protected static $pool = null;
 
 	public static function init() : void{
@@ -158,28 +158,28 @@ class PacketPool{
 	}
 
 	/**
-	 * @param DataPacket $packet
+	 * @param Packet $packet
 	 */
-	public static function registerPacket(DataPacket $packet) : void{
+	public static function registerPacket(Packet $packet) : void{
 		static::$pool[$packet->pid()] = clone $packet;
 	}
 
 	/**
 	 * @param int $pid
 	 *
-	 * @return DataPacket
+	 * @return Packet
 	 */
-	public static function getPacketById(int $pid) : DataPacket{
+	public static function getPacketById(int $pid) : Packet{
 		return isset(static::$pool[$pid]) ? clone static::$pool[$pid] : new UnknownPacket();
 	}
 
 	/**
 	 * @param string $buffer
 	 *
-	 * @return DataPacket
+	 * @return Packet
 	 * @throws BadPacketException
 	 */
-	public static function getPacket(string $buffer) : DataPacket{
+	public static function getPacket(string $buffer) : Packet{
 		$offset = 0;
 		try{
 			$pk = static::getPacketById(Binary::readUnsignedVarInt($buffer, $offset));