Implement chat history.

client.go

@@ -127,7 +127,7 @@ func startClient(conn *websocket.Conn) (err error) {
 
 	defer close(c.done)
 
-	c.writeCh = make(chan interface{}, 1)
+	c.writeCh = make(chan interface{}, 25)
 	defer func() {
 		if isWSNormalError(err) {
 			err = nil
@@ -693,6 +693,20 @@ func clientLoop(c *client, conn *websocket.Conn) error {
 		cc.action(pushTracksAction{c})
 	}
 
+	h := c.group.getChatHistory()
+	for _, m := range h {
+		err := c.write(clientMessage{
+			Type:     "chat",
+			Id:       m.id,
+			Username: m.user,
+			Value:    m.value,
+			Me:       m.me,
+		})
+		if err != nil {
+			return err
+		}
+	}
+
 	ticker := time.NewTicker(2 * time.Second)
 	defer ticker.Stop()
 
@@ -819,6 +833,7 @@ func handleClientMessage(c *client, m clientMessage) error {
 			log.Printf("ICE: %v", err)
 		}
 	case "chat":
+		c.group.addToChatHistory(m.Id, m.Username, m.Value, m.Me)
 		clients := c.group.getClients(c)
 		for _, cc := range clients {
 			cc.write(m)

group.go

@@ -51,6 +51,13 @@ type client struct {
 	up          map[string]*upConnection
 }
 
+type chatHistoryEntry struct {
+	id    string
+	user  string
+	value string
+	me    bool
+}
+
 type group struct {
 	name        string
 	dead        bool
@@ -58,6 +65,7 @@ type group struct {
 
 	mu      sync.Mutex
 	clients []*client
+	history []chatHistoryEntry
 }
 
 type delPCAction struct {
@@ -259,6 +267,30 @@ func (g *group) Range(f func(c *client) bool) {
 	}
 }
 
+const maxChatHistory = 20
+
+func (g *group) addToChatHistory(id, user, value string, me bool) {
+	g.mu.Lock()
+	defer g.mu.Unlock()
+
+	if len(g.history) >= maxChatHistory {
+		copy(g.history, g.history[1:])
+		g.history = g.history[:len(g.history)-1]
+	}
+	g.history = append(g.history,
+		chatHistoryEntry{id: id, user: user, value: value, me: me},
+	)
+}
+
+func (g *group) getChatHistory() []chatHistoryEntry {
+	g.mu.Lock()
+	g.mu.Unlock()
+
+	h := make([]chatHistoryEntry, len(g.history))
+	copy(h, g.history)
+	return h
+}
+
 type writerDeadError int
 
 func (err writerDeadError) Error() string {

static/sfu.js

@@ -283,6 +283,7 @@ function serverConnect() {
         };
         socket.onopen = function(e) {
             resetUsers();
+            resetChat();
             setConnected(true);
             let up = getUserPass();
             send({
@@ -648,6 +649,11 @@ function addToChatbox(peerId, nick, message, me){
     return message;
 }
 
+function resetChat() {
+    lastMessage = {};
+    document.getElementById('box').textContent = '';
+}
+
 function handleInput() {
     let username = getUsername();
     let input = document.getElementById('input');
@@ -729,6 +735,7 @@ function handleInput() {
     addToChatbox(myid, username, message, me);
     send({
         type: 'chat',
+        id: myid,
         username: username,
         value: message,
         me: me,