hub.go

package main

// import "log"

type hub struct {
	// Registered clients
	clients map[*client]bool

	// Inbound messages
	broadcast chan string

	// Register requests
	register chan *client

	// Unregister requests
	unregister chan *client

	content string
}

var h = hub{
	broadcast:   make(chan string),
	register:    make(chan *client),
	unregister:  make(chan *client),
	clients: make(map[*client]bool),
	content:  	 "",
}

func (h *hub) run() {

	for { //forever
		select {
		case c := <-h.register:
			h.clients[c] = true
			c.send <- []byte(h.content)
			break

		case c := <-h.unregister:
			_, ok := h.clients[c]
			if ok {
				delete(h.clients, c)
				close(c.send)
			}
			break

		case m := <-h.broadcast:
			h.content = m
			h.broadcastMessage()
			break
		}
	}
}

func (h *hub) broadcastMessage() {
	for c := range h.clients {
		select {
		case c.send <- []byte(h.content):
			break

		// We can't reach the client
		default:
			close(c.send)
			delete(h.clients, c)
		}
	}
}