Set.Each, also builtin Channel broadcast goroutine

chat/channel.go

@@ -3,6 +3,7 @@ package chat
 import "fmt"
 
 const historyLen = 20
+const channelBuffer = 10
 
 // Channel definition, also a Set of User Items
 type Channel struct {
@@ -10,19 +11,35 @@ type Channel struct {
 	topic     string
 	history   *History
 	users     *Set
-	broadcast chan<- Message
+	broadcast chan Message
 }
 
-func NewChannel(id string, broadcast chan<- Message) *Channel {
+// Create new channel and start broadcasting goroutine.
+func NewChannel(id string) *Channel {
+	broadcast := make(chan Message, channelBuffer)
+
 	ch := Channel{
 		id:        id,
 		broadcast: broadcast,
 		history:   NewHistory(historyLen),
 		users:     NewSet(),
 	}
+
+	go func() {
+		for m := range broadcast {
+			ch.users.Each(func(u Item) {
+				u.(*User).Send(m)
+			})
+		}
+	}()
+
 	return &ch
 }
 
+func (ch *Channel) Close() {
+	close(ch.broadcast)
+}
+
 func (ch *Channel) Send(m Message) {
 	ch.broadcast <- m
 }

chat/channel_test.go

@@ -8,20 +8,12 @@ import (
 func TestChannel(t *testing.T) {
 	var expected, actual []byte
 
-	out := make(chan Message)
-	defer close(out)
-
 	s := &MockScreen{}
 	u := NewUser("foo")
 
-	go func() {
-		for msg := range out {
-			t.Logf("Broadcasted: ", msg.String())
-			u.Send(msg)
-		}
-	}()
+	ch := NewChannel("")
+	defer ch.Close()
 
-	ch := NewChannel("", out)
 	err := ch.Join(u)
 	if err != nil {
 		t.Error(err)

chat/host.go

@@ -24,18 +24,5 @@ func (h *Host) broadcast(ch *Channel, m Message) {
 }
 
 func (h *Host) CreateChannel(id string) *Channel {
-	out := make(chan Message, 20)
-	ch := NewChannel(id, out)
-
-	go func() {
-		for msg := range out {
-			if msg.IsCommand() {
-				go h.handleCommand(msg)
-				continue
-			}
-			h.broadcast(ch, msg)
-		}
-	}()
-
-	return ch
+	return NewChannel(id)
 }

chat/set.go

@@ -87,6 +87,15 @@ func (s *Set) Remove(item Item) error {
 	return nil
 }
 
+// Loop over every item while holding a read lock and apply fn
+func (s *Set) Each(fn func(item Item)) {
+	s.RLock()
+	for _, item := range s.lookup {
+		fn(item)
+	}
+	s.RUnlock()
+}
+
 // List users by prefix, case insensitive
 func (s *Set) ListPrefix(prefix string) []Item {
 	r := []Item{}