001/* 002 * Trident - A Multithreaded Server Alternative 003 * Copyright 2014 The TridentSDK Team 004 * 005 * Licensed under the Apache License, Version 2.0 (the "License"); 006 * you may not use this file except in compliance with the License. 007 * You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017 018package net.tridentsdk.server.netty.packet; 019 020import io.netty.buffer.ByteBuf; 021import net.tridentsdk.docs.InternalUseOnly; 022import net.tridentsdk.server.netty.ClientConnection; 023 024/** 025 * Data bearing abstraction that represents a piece of information to communicate between server and client 026 * 027 * @author The TridentSDK Team 028 */ 029public interface Packet { 030 /** 031 * Sets the fields of the packet from the data serialized into the buffer 032 * 033 * @param buf the buffer storing the serialized packet data 034 * @return the this instance of the packet 035 */ 036 Packet decode(ByteBuf buf); 037 038 /** 039 * Serialized the data held by this packet into a buffer 040 * 041 * @param buf the buffer to toPacket to 042 */ 043 void encode(ByteBuf buf); 044 045 /** 046 * Handles the packet after receiving it from a connection, is invoked by the ClientConnection that received it 047 * 048 * <p>Used to allow the packet to notify the {@link net.tridentsdk.server.netty.ClientConnection} 049 * of packets the server receives, and make changes specific to this packet</p> 050 * 051 * @param connection The connection that sent the packet 052 */ 053 @InternalUseOnly 054 void handleReceived(ClientConnection connection); 055 056 /** 057 * Gets the ID of this packet, according to the protocol specification 058 * 059 * @return packet ID 060 */ 061 int id(); 062 063 /** 064 * Returns the packet direction 065 * 066 * @return {@link net.tridentsdk.server.netty.packet.PacketDirection#IN} or 067 * {@link net.tridentsdk.server.netty.packet.PacketDirection#OUT} depending on direction 068 */ 069 PacketDirection direction(); 070}