// ackFollower sends an acknowledgement to the follower.
func (b *Broker) ackFollower(f *Follower) error {
b.lock.Lock()
defer b.lock.Unlock()
ack := new(protocol.Ack)
if b.role != LEADER || f.conn.RemoteAddr().String() == b.Origin() {
log.Warn("Denying follow requests from %s.", f.conn.RemoteAddr())
ack.Status = protocol.StatusFailure
} else {
inner := new(protocol.FollowACK)
inner.Truncate = make(Offsets)
for topic, checkpoint := range b.checkpoints {
log.Info("Checkpoint is %v", checkpoint)
if f.tails[topic] > checkpoint {
inner.Truncate[topic] = checkpoint
f.tails[topic] = checkpoint
}
}
ack.Status = protocol.StatusSuccess
ack.Payload, _ = json.Marshal(inner)
}
return websocket.JSON.Send(f.conn, ack)
}
// producer handles incoming produce requests. Producers may send multiple
// produce requests on the same persistent connection. The function exits when
// an `io.EOF` is received on the connection.
func producer(conn *websocket.Conn) {
defer conn.Close()
for {
var request protocol.ProduceRequest
err := websocket.JSON.Receive(conn, &request)
if err == io.EOF { // graceful shutdown
break
}
if nil != err {
log.Warn("Ignoring invalid message from %v.", conn.RemoteAddr())
continue
}
ack := new(protocol.Ack)
if err := broker.Publish(request.Topic, request.ID, &request.Message); nil != err {
log.Error(err.Error())
ack.Status = protocol.StatusFailure
} else {
ack.Status = protocol.StatusSuccess
}
// TODO: should redirect if this node is not the leader
websocket.JSON.Send(conn, &ack)
}
log.Info("Closed producer connection from %v.", conn.RemoteAddr())
}