generate unique id using timestamp + random bits

- used rs/xid package
- change Players to use id as key
- players with same name can now play concurrently

server/arena/arena.go

@@ -79,14 +79,13 @@ func (a *Arena) CollisionDetection() {
 }
 
 // AddPlayer adds a new player to the arena
-func (a *Arena) AddPlayer(n string, ws *websocket.Conn) error {
+func (a *Arena) AddPlayer(id string, n string, ws *websocket.Conn) error {
 	color, err := a.generateRandomColor()
 	if err != nil {
 		return err
 	}
-
 	position := a.generateCoordinate(models.PlayerRadius)
-	a.Players[n] = models.CreatePlayer(n, position, color, ws)
+	a.Players[id] = models.CreatePlayer(id, n, position, color, ws)
 	return nil
 }
 

server/main.go

@@ -8,6 +8,7 @@ import (
 	"time"
 
 	"github.com/gorilla/websocket"
+	"github.com/rs/xid"
 	"github.com/ubclaunchpad/bumper/server/arena"
 	"github.com/ubclaunchpad/bumper/server/models"
 )
@@ -29,6 +30,11 @@ var upgrader = websocket.Upgrader{
 	},
 }
 
+func genUniqueId() string {
+	id := xid.New()
+	return id.String()
+}
+
 // ServeHTTP handles a connection from a client
 // Upgrades client's connection to WebSocket and listens for messages
 func (g *Game) ServeHTTP(w http.ResponseWriter, r *http.Request) {
@@ -40,12 +46,13 @@ func (g *Game) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	defer ws.Close()
 
 	name := r.URL.Query().Get("name")
+	id := genUniqueId()
 	for {
 		var msg models.Message
 		err := ws.ReadJSON(&msg)
 		if err != nil {
 			log.Printf("%v\n", err)
-			delete(g.Arena.Players, name)
+			delete(g.Arena.Players, id)
 			break
 		}
 
@@ -58,15 +65,15 @@ func (g *Game) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 				continue
 			}
 
-			err := g.Arena.AddPlayer(name, ws)
+			err := g.Arena.AddPlayer(id, name, ws)
 			if err != nil {
 				log.Printf("Error adding player:\n%v", err)
 				continue
 			}
 
 			initialMsg := models.Message{
 				Type: "initial",
-				Data: name,
+				Data: id,
 			}
 			MessageChannel <- initialMsg
 
@@ -77,11 +84,11 @@ func (g *Game) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 				log.Printf("%v\n", err)
 				continue
 			}
-			if _, ok := g.Arena.Players[name]; ok {
+			if _, ok := g.Arena.Players[id]; ok {
 				if kh.IsPressed {
-					g.Arena.Players[name].KeyDownHandler(kh.Key)
+					g.Arena.Players[id].KeyDownHandler(kh.Key)
 				} else {
-					g.Arena.Players[name].KeyUpHandler(kh.Key)
+					g.Arena.Players[id].KeyUpHandler(kh.Key)
 				}
 			}
 
@@ -119,13 +126,13 @@ func tick(g *Game) {
 		}
 
 		// update every client
-		for name := range g.Arena.Players {
-			p := g.Arena.Players[name]
+		for id := range g.Arena.Players {
+			p := g.Arena.Players[id]
 			err := p.SendJSON(&msg)
 			if err != nil {
 				log.Printf("error: %v", err)
 				p.Close()
-				delete(g.Arena.Players, name)
+				delete(g.Arena.Players, id)
 			}
 		}
 	}
@@ -137,8 +144,8 @@ func messageEmitter(g *Game) {
 
 		switch msg.Type {
 		case "initial":
-			name := msg.Data.(string)
-			p := g.Arena.Players[name]
+			id := msg.Data.(string)
+			p := g.Arena.Players[id]
 
 			initalMsg := models.Message{
 				Type: "initial",
@@ -153,23 +160,23 @@ func messageEmitter(g *Game) {
 			if err != nil {
 				log.Printf("error: %v", err)
 				p.Close()
-				delete(g.Arena.Players, name)
+				delete(g.Arena.Players, id)
 			}
 
 		case "death":
-			name := msg.Data.(string)
+			id := msg.Data.(string)
 			deathMsg := models.Message{
 				Type: "death",
 				Data: nil,
 			}
 
-			p := g.Arena.Players[name]
+			p := g.Arena.Players[id]
 			err := p.SendJSON(&deathMsg)
 			if err != nil {
 				log.Printf("error: %v", err)
 				p.Close()
 			}
-			delete(g.Arena.Players, name)
+			delete(g.Arena.Players, id)
 
 		default:
 			log.Println("Unknown message type to emit")

server/models/player.go

@@ -36,6 +36,7 @@ type KeysPressed struct {
 // Player contains data and state about a player's object
 type Player struct {
 	Name     string      `json:"name"`
+	ID       string      `json:"id"`
 	Position Position    `json:"position"`
 	Velocity Velocity    `json:"-"`
 	Color    string      `json:"color"`
@@ -48,9 +49,10 @@ type Player struct {
 
 // CreatePlayer constructs an instance of player with
 // given position, color, and WebSocket connection
-func CreatePlayer(n string, p Position, c string, ws *websocket.Conn) *Player {
+func CreatePlayer(id string, n string, p Position, c string, ws *websocket.Conn) *Player {
 	return &Player{
 		Name:     n,
+		ID:       id,
 		Position: p,
 		Velocity: Velocity{},
 		Color:    c,