// Enqueue send a message to the topic. All subscriptions receive a copy
// of the message.
func (t *Topic) Enqueue(f *frame.Frame) {
switch t.subs.Len() {
case 0:
// no subscription, so do nothing
case 1:
// only one subscription, so can send the frame
// without copying
sub := t.subs.Front().Value.(Subscription)
sub.SendTopicFrame(f)
default:
// more than one subscription, send clone for
// all subscriptions except the last, which can
// have the frame without copying
for e := t.subs.Front(); e != nil; e = e.Next() {
sub := e.Value.(Subscription)
if e.Next() == nil {
// the last in the list, send the frame
// without copying
sub.SendTopicFrame(f)
} else {
sub.SendTopicFrame(f.Clone())
}
}
}
}
