room.go

package main

// A room represents a chatting room in a chat app
type room struct {
	clients    map[*client]bool // clients contains all the clients registered in this room
	register   chan *client     // register channel holds clients willing to join this room
	unregister chan *client     // unregister channel holds clients willing to leave this room
	broadcast  chan []byte      // message channel holds incoming messages to be forwarded to all the clients in this room
}

/************************************************************************************
 *	This is a receiver function of type room. It subscribes to the web socket
 *	and read if theres is any message received from the client. Any incoming message
 *	is then sent to the broadcast channel of the room in which the client is currently
 *	chatting.

 **************************************************************************************/
func (r *room) run() {
	for {
		select {
		case c := <-r.register:
			r.clients[c] = true
		case c := <-r.unregister:
			delete(r.clients, c)
			close(c.send)

		case msg := <-r.broadcast:
			for c := range r.clients {
				select {
				case c.send <- msg:
				default:
					close(c.send)
					delete(r.clients, c)
				}

			}
		}
	}
}