Tutorial¶

This tutorial walks you through creating a simple chat application with MafiaNet.

Project Setup¶

Create a new project with the following files:

ChatCommon.h - Shared definitions
ChatServer.cpp - Server application
ChatClient.cpp - Client application

Shared Definitions¶

Create ChatCommon.h:

#pragma once
#include "mafianet/MessageIdentifiers.h"

// Custom message types
enum ChatMessages {
    ID_CHAT_MESSAGE = ID_USER_PACKET_ENUM,
    ID_SERVER_MESSAGE,
};

const unsigned short SERVER_PORT = 60000;
const unsigned short MAX_CLIENTS = 32;

The Server¶

Create ChatServer.cpp:

#include "mafianet/peerinterface.h"
#include "mafianet/BitStream.h"
#include "mafianet/string.h"
#include "ChatCommon.h"
#include <cstdio>

int main() {
    MafiaNet::RakPeerInterface* server = MafiaNet::RakPeerInterface::GetInstance();

    // Start server
    MafiaNet::SocketDescriptor sd(SERVER_PORT, 0);
    MafiaNet::StartupResult result = server->Startup(MAX_CLIENTS, &sd, 1);

    if (result != MafiaNet::RAKNET_STARTED) {
        printf("Failed to start server\n");
        return 1;
    }

    server->SetMaximumIncomingConnections(MAX_CLIENTS);
    printf("Chat server started on port %d\n", SERVER_PORT);

    // Main loop
    while (true) {
        MafiaNet::Packet* packet;
        for (packet = server->Receive(); packet;
             server->DeallocatePacket(packet), packet = server->Receive()) {

            switch (packet->data[0]) {
                case ID_NEW_INCOMING_CONNECTION:
                    printf("Client connected: %s\n",
                           packet->systemAddress.ToString());
                    break;

                case ID_DISCONNECTION_NOTIFICATION:
                case ID_CONNECTION_LOST:
                    printf("Client disconnected: %s\n",
                           packet->systemAddress.ToString());
                    break;

                case ID_CHAT_MESSAGE: {
                    // Read the message
                    MafiaNet::BitStream bs(packet->data, packet->length, false);
                    bs.IgnoreBytes(1);

                    MafiaNet::RakString message;
                    bs.Read(message);

                    printf("[%s]: %s\n",
                           packet->systemAddress.ToString(),
                           message.C_String());

                    // Broadcast to all clients
                    server->Send(&bs, MEDIUM_PRIORITY, RELIABLE_ORDERED,
                                0, packet->systemAddress, true);
                    break;
                }
            }
        }

        // Small sleep to prevent busy loop
        MafiaNet::RakSleep(30);
    }

    MafiaNet::RakPeerInterface::DestroyInstance(server);
    return 0;
}

The Client¶

Create ChatClient.cpp:

#include "mafianet/peerinterface.h"
#include "mafianet/BitStream.h"
#include "mafianet/string.h"
#include "mafianet/Gets.h"
#include "ChatCommon.h"
#include <cstdio>
#include <cstring>

int main() {
    MafiaNet::RakPeerInterface* client = MafiaNet::RakPeerInterface::GetInstance();

    MafiaNet::SocketDescriptor sd;
    client->Startup(1, &sd, 1);

    printf("Enter server IP (or press Enter for localhost): ");
    char serverIP[64];
    Gets(serverIP, sizeof(serverIP));
    if (strlen(serverIP) == 0) {
        strcpy(serverIP, "127.0.0.1");
    }

    printf("Connecting to %s:%d...\n", serverIP, SERVER_PORT);
    client->Connect(serverIP, SERVER_PORT, nullptr, 0);

    bool connected = false;
    char message[256];

    while (true) {
        // Process network packets
        MafiaNet::Packet* packet;
        for (packet = client->Receive(); packet;
             client->DeallocatePacket(packet), packet = client->Receive()) {

            switch (packet->data[0]) {
                case ID_CONNECTION_REQUEST_ACCEPTED:
                    printf("Connected! Type messages and press Enter.\n");
                    connected = true;
                    break;

                case ID_CONNECTION_ATTEMPT_FAILED:
                    printf("Connection failed.\n");
                    return 1;

                case ID_DISCONNECTION_NOTIFICATION:
                case ID_CONNECTION_LOST:
                    printf("Disconnected.\n");
                    connected = false;
                    return 0;

                case ID_CHAT_MESSAGE: {
                    MafiaNet::BitStream bs(packet->data, packet->length, false);
                    bs.IgnoreBytes(1);

                    MafiaNet::RakString msg;
                    bs.Read(msg);
                    printf(">> %s\n", msg.C_String());
                    break;
                }
            }
        }

        // Check for user input (non-blocking)
        if (connected && kbhit()) {
            Gets(message, sizeof(message));
            if (strlen(message) > 0) {
                MafiaNet::BitStream bs;
                bs.Write((MafiaNet::MessageID)ID_CHAT_MESSAGE);
                bs.Write(MafiaNet::RakString(message));
                client->Send(&bs, MEDIUM_PRIORITY, RELIABLE_ORDERED,
                            0, MafiaNet::UNASSIGNED_SYSTEM_ADDRESS, true);
            }
        }

        MafiaNet::RakSleep(30);
    }

    MafiaNet::RakPeerInterface::DestroyInstance(client);
    return 0;
}

Building¶

Link against the MafiaNet library when compiling:

# Linux/macOS
g++ -std=c++17 ChatServer.cpp -o ChatServer -lmafianet -lpthread
g++ -std=c++17 ChatClient.cpp -o ChatClient -lmafianet -lpthread

# Or with CMake
target_link_libraries(ChatServer MafiaNet::MafiaNet)
target_link_libraries(ChatClient MafiaNet::MafiaNet)

Running¶

Start the server: ./ChatServer
Start one or more clients: ./ChatClient
Type messages in clients and see them broadcast to all

Next Steps¶

Enhance this example with:

User names and join/leave notifications
Private messaging
Server commands (kick, ban)
Message history