server.go

package main

import (
	"github.com/codegangsta/martini"
	"github.com/gorilla/websocket"
	"log"
	"net"
	"net/http"
	"sync"
)

var ActiveClients = make(map[ClientConn]int)
var ActiveClientsRWMutex sync.RWMutex

type ClientConn struct {
	websocket *websocket.Conn
	clientIP  net.Addr
}

func addClient(cc ClientConn) {
	ActiveClientsRWMutex.Lock()
	ActiveClients[cc] = 0
	ActiveClientsRWMutex.Unlock()
}

func deleteClient(cc ClientConn) {
	ActiveClientsRWMutex.Lock()
	delete(ActiveClients, cc)
	ActiveClientsRWMutex.Unlock()
}

func broadcastMessage(messageType int, message []byte) {
	ActiveClientsRWMutex.RLock()
	defer ActiveClientsRWMutex.RUnlock()

	for client, _ := range ActiveClients {
		if err := client.websocket.WriteMessage(messageType, message); err != nil {
			return
		}
	}
}

func main() {
	m := martini.Classic()

	m.Get("/sock", func(w http.ResponseWriter, r *http.Request) {
		log.Println(ActiveClients)
		ws, err := websocket.Upgrade(w, r, nil, 1024, 1024)
		if _, ok := err.(websocket.HandshakeError); ok {
			http.Error(w, "Not a websocket handshake", 400)
			return
		} else if err != nil {
			log.Println(err)
			return
		}
		client := ws.RemoteAddr()
		sockCli := ClientConn{ws, client}
		addClient(sockCli)

		for {
			log.Println(len(ActiveClients), ActiveClients)
			messageType, p, err := ws.ReadMessage()
			if err != nil {
				deleteClient(sockCli)
				log.Println("bye")
				log.Println(err)
				return
			}
			broadcastMessage(messageType, p)
		}
	})
	m.Run()
}