tea.melonie54.xyz/melonie/snowball

Small communication protocol for TCP connections

Example client:

wg := &sync.WaitGroup{}

// Resolve TCP address
tcpAddr, err := net.ResolveTCPAddr("tcp", "127.0.0.1:12345")
if err != nil {
	t.Fatal(err)
}

// Create snowball client
var snow *SnowballClient
snow = NewSnowballClient(wg, 3, tcpAddr, func(packet *packet.SnowballPacket) {
	// Packet receiving logic only packets with `toAddr = 3` will be handled here
	// Packets with `toAddr = 2` are forwarded to all clients from the server but
	// the `toAddr` is changed to match to receiving client ID
	switch packet.Id {
	case 2: 
		// `MakeReply` can be used to create a packet to send back to the return address 
		snow.Send(packet.MakeReply(3, packet.Data))
	}
})

// A WaitGroup can be used to prevent the program from closing
wg.Wait()

// Create and send a packet (with ID: 2) to client (with ID: 4)
// The from address is set to the current client
// A binary packet can be generated using a byte buffer and the functions in `net-byte-utils.go`
buf := new(bytes.Buffer)
utils.WriteString(buf, "hello")
snow.Send(NewSnowballPacketFromBytes(2, 0, 4, buf.Bytes()))

Example server:

wg := &sync.WaitGroup{}

tcpAddr, err := net.ResolveTCPAddr("tcp", "127.0.0.1:12346")
if err != nil {
	t.Fatal(err)
}

var snow *SnowballServer
snow = NewSnowballServer(wg, tcpAddr, func(packet *packet.SnowballPacket) {
	// Packet receiving logic only packets with `toAddr = 1` will be handled here
	// Packets with other addresses are automatically routed to the client
	// Packets with `toAddr = 2` are forwarded to all clients automatically
	switch packet.Id {
	case 2: 
		// `MakeReply` can be used to create a packet to send back to the return address 
		snow.Send(packet.MakeReply(3, packet.Data))
	}
})
if err != nil {
	t.Fatal(err)
}
// `Serve` is non-blocking
snow.Serve()

// A WaitGroup can be used to prevent the program from closing
wg.Wait()

Packet IDs:

• 0x00 - Reserved for the unknown packet
• 0x01 - Reserved for the Hello packet

Client IDs:

• 0x00 - Reserved for the unknown client (if used as fromAddr it is changed to the current client ID before sending)
• 0x01 - Reserved for the server
• 0x02 - Reserved for sending packets to all clients (can be used from the client or server Send methods)