enet

go-enet

Enet bindings for Go using cgo.

Installation

First, you might need to install enet as a dependency:

• Windows: Nothing to do - should work out of the box with the supplied headers and library.
• Linux: Install the enet development package with your package manager.
  • On Debian-based systems: apt install libenet-dev
• MacOS: Install the enet package with brew: brew install enet

Since this module uses cgo, you must also make sure you have a C compiler in your PATH. For Linux and Mac, this is usually pretty straight forward. On Windows, you may have to use something like MSYS2.

When ready, get the module like this:

$ go get github.com/codecat/go-enet

Usage

import "github.com/codecat/go-enet"

The API is mostly the same as the C API, except it's more object-oriented.

Server example

This is a basic server example that responds to packets "ping" and "bye".

package main

import (
	"github.com/codecat/go-enet"
	"github.com/codecat/go-libs/log"
)

func main() {
	// Initialize enet
	enet.Initialize()

	// Create a host listening on 0.0.0.0:8095
	host, err := enet.NewHost(enet.NewListenAddress(8095), 32, 1, 0, 0)
	if err != nil {
		log.Error("Couldn't create host: %s", err.Error())
		return
	}

	// The event loop
	for true {
		// Wait until the next event
		ev := host.Service(1000)

		// Do nothing if we didn't get any event
		if ev.GetType() == enet.EventNone {
			continue
		}

		switch ev.GetType() {
		case enet.EventConnect: // A new peer has connected
			log.Info("New peer connected: %s", ev.GetPeer().GetAddress())

		case enet.EventDisconnect: // A connected peer has disconnected
			log.Info("Peer disconnected: %s", ev.GetPeer().GetAddress())

		case enet.EventReceive: // A peer sent us some data
			// Get the packet
			packet := ev.GetPacket()

			// We must destroy the packet when we're done with it
			defer packet.Destroy()

			// Get the bytes in the packet
			packetBytes := packet.GetData()

			// Respond "pong" to "ping"
			if string(packetBytes) == "ping" {
				ev.GetPeer().SendString("pong", ev.GetChannelID(), enet.PacketFlagReliable)
				continue
			}

			// Disconnect the peer if they say "bye"
			if string(packetBytes) == "bye" {
				log.Info("Bye!")
				ev.GetPeer().Disconnect(0)
				continue
			}
		}
	}

	// Destroy the host when we're done with it
	host.Destroy()

	// Uninitialize enet
	enet.Deinitialize()
}

Client example

This is a basic client example that sends a ping to the server every second that there is no event.

package main

import (
	"github.com/codecat/go-enet"
	"github.com/codecat/go-libs/log"
)

func main() {
	// Initialize enet
	enet.Initialize()

	// Create a client host
	client, err := enet.NewHost(nil, 1, 1, 0, 0)
	if err != nil {
		log.Error("Couldn't create host: %s", err.Error())
		return
	}

	// Connect the client host to the server
	peer, err := client.Connect(enet.NewAddress("127.0.0.1", 8095), 1, 0)
	if err != nil {
		log.Error("Couldn't connect: %s", err.Error())
		return
	}

	// The event loop
	for true {
		// Wait until the next event
		ev := client.Service(1000)

		// Send a ping if we didn't get any event
		if ev.GetType() == enet.EventNone {
			peer.SendString("ping", 0, enet.PacketFlagReliable)
			continue
		}

		switch ev.GetType() {
		case enet.EventConnect: // We connected to the server
			log.Info("Connected to the server!")

		case enet.EventDisconnect: // We disconnected from the server
			log.Info("Lost connection to the server!")

		case enet.EventReceive: // The server sent us data
			packet := ev.GetPacket()
			log.Info("Received %d bytes from server", len(packet.GetData()))
			packet.Destroy()
		}
	}

	// Destroy the host when we're done with it
	client.Destroy()

	// Uninitialize enet
	enet.Deinitialize()
}