func snapshots(socket *zmq.Socket, srv *clonesrv_t) (err error) {
msg, err := socket.RecvMessage(0)
if err != nil {
return
}
identity := msg[0]
// Request is in second frame of message
request := msg[1]
if request != "ICANHAZ?" {
err = errors.New("E: bad request, aborting")
return
}
subtree := msg[2]
// Send state socket to client
for _, kvmsg := range srv.kvmap {
if key, _ := kvmsg.GetKey(); strings.HasPrefix(key, subtree) {
socket.Send(identity, zmq.SNDMORE)
kvmsg.Send(socket)
}
}
// Now send END message with sequence number
log.Println("I: sending shapshot =", srv.sequence)
socket.Send(identity, zmq.SNDMORE)
kvmsg := kvmsg.NewKvmsg(srv.sequence)
kvmsg.SetKey("KTHXBAI")
kvmsg.SetBody(subtree)
kvmsg.Send(socket)
return
}
func send_hugz(srv *clonesrv_t) (err error) {
kvmsg := kvmsg.NewKvmsg(srv.sequence)
kvmsg.SetKey("HUGZ")
kvmsg.SetBody("")
err = kvmsg.Send(srv.publisher)
return
}
func (agent *agent_t) control_message() (err error) {
msg, e := agent.pipe.RecvMessage(0)
if e != nil {
return e
}
command := msg[0]
msg = msg[1:]
switch command {
case "SUBTREE":
agent.subtree = msg[0]
case "CONNECT":
address := msg[0]
service := msg[1]
if agent.nbr_servers < server_MAX {
serv, _ := strconv.Atoi(service)
agent.server[agent.nbr_servers] = server_new(address, serv, agent.subtree)
agent.nbr_servers++
// We broadcast updates to all known servers
agent.publisher.Connect(fmt.Sprintf("%s:%d", address, serv+2))
} else {
fmt.Printf("E: too many servers (max. %d)\n", server_MAX)
}
case "SET":
// When we set a property, we push the new key-value pair onto
// all our connected servers:
key := msg[0]
value := msg[1]
ttl := msg[2]
// Send key-value pair on to server
kvmsg := kvmsg.NewKvmsg(0)
kvmsg.SetKey(key)
kvmsg.SetUuid()
kvmsg.SetBody(value)
kvmsg.SetProp("ttl", ttl)
kvmsg.Store(agent.kvmap)
kvmsg.Send(agent.publisher)
case "GET":
key := msg[0]
value := ""
if kvmsg, ok := agent.kvmap[key]; ok {
value, _ = kvmsg.GetBody()
}
agent.pipe.SendMessage(value)
}
return
}
func main() {
snapshot, _ := zmq.NewSocket(zmq.DEALER)
snapshot.Connect("tcp://localhost:5556")
subscriber, _ := zmq.NewSocket(zmq.SUB)
subscriber.SetSubscribe(SUBTREE)
subscriber.Connect("tcp://localhost:5557")
publisher, _ := zmq.NewSocket(zmq.PUSH)
publisher.Connect("tcp://localhost:5558")
kvmap := make(map[string]*kvmsg.Kvmsg)
rand.Seed(time.Now().UnixNano())
// We first request a state snapshot:
sequence := int64(0)
snapshot.SendMessage("ICANHAZ?", SUBTREE)
for {
kvmsg, err := kvmsg.RecvKvmsg(snapshot)
if err != nil {
break // Interrupted
}
if key, _ := kvmsg.GetKey(); key == "KTHXBAI" {
sequence, _ := kvmsg.GetSequence()
fmt.Println("I: received snapshot =", sequence)
break // Done
}
kvmsg.Store(kvmap)
}
snapshot.Close()
poller := zmq.NewPoller()
poller.Add(subscriber, zmq.POLLIN)
alarm := time.Now().Add(1000 * time.Millisecond)
for {
tickless := alarm.Sub(time.Now())
if tickless < 0 {
tickless = 0
}
polled, err := poller.Poll(tickless)
if err != nil {
break // Context has been shut down
}
if len(polled) == 1 {
kvmsg, err := kvmsg.RecvKvmsg(subscriber)
if err != nil {
break // Interrupted
}
// Discard out-of-sequence kvmsgs, incl. heartbeats
if seq, _ := kvmsg.GetSequence(); seq > sequence {
sequence = seq
kvmsg.Store(kvmap)
fmt.Println("I: received update =", sequence)
}
}
// If we timed-out, generate a random kvmsg
if time.Now().After(alarm) {
kvmsg := kvmsg.NewKvmsg(0)
kvmsg.SetKey(fmt.Sprintf("%s%d", SUBTREE, rand.Intn(10000)))
kvmsg.SetBody(fmt.Sprint(rand.Intn(1000000)))
kvmsg.SetProp("ttl", fmt.Sprintf("%d", rand.Intn((30)))) // seconds
kvmsg.Send(publisher)
alarm = time.Now().Add(1000 * time.Millisecond)
}
}
fmt.Printf("Interrupted\n%d messages in\n", sequence)
}