/**
* process subscriber commands
* when feed command is received, data must be received within 30 seconds or subscriber will unsubscribe
*/
func (s *Subscriber) subscriberCommandProcess(h *Hub) {
l.If("subscriber process - %s - start", s.id)
defer l.If("subscriber process - %s - end", s.id)
for {
select {
case subscriberCommand := <-s.commandListener:
switch subscriberCommand.command {
case SubscriberStop:
l.If("subscriber process - %s - stop", s.id)
return
case SubscriberFeed:
l.If("subscriber process - %s - feed", s.id)
select {
case s.feedListener <- subscriberCommand.SubscriberFeedCommand:
case <-time.After(30 * time.Second):
l.Wf("subscriber process - %s - feed timedout", s.id)
h.subscriberCommandListener <- HubSubscriberRequest{Unsubscribe, s.id, nil, nil}
return
}
}
case <-time.After(30 * time.Second):
l.If("subscriber process - %s - alive", s.id)
}
}
}
/**
* handles adding, removing, cleaning and feeding subscribers
*/
func (h *Hub) subscribersProcess() {
l.I("subscribers process - starting")
for {
select {
case newData := <-h.subscriberFeedListener:
l.If("subscribers process - newData", newData)
for _, subscriber := range h.subscribers {
if subscriber.channels[newData.channelData.ChannelName] != nil {
select {
case subscriber.commandListener <- SubscriberControlCommand{SubscriberFeed, CreateSingleFeedCommad(string(newData.operation), newData.channelData.ChannelName, newData.channelData.Data, newData.channelData.DataVersion)}:
default:
l.Wf("subscribers process - did not deliver new data to %s - queue full", subscriber.id)
}
}
}
case subscriberCommand := <-h.subscriberCommandListener:
switch subscriberCommand.command {
case Subscribe:
l.I("subscribers process - subscribe")
newSubscriber := h.createSubscriber(subscriberCommand.channels)
subscriberCommand.responseListener <- newSubscriber
case Unsubscribe:
l.If("subscribers process - %s - unsubscribe", subscriberCommand.subscriberId)
h.deleteSubscriber(subscriberCommand.subscriberId)
subscriberCommand.responseListener <- Subscriber{}
case SubscribeToChannels:
l.If("subscribers process - %s - subscribe to channels", subscriberCommand.subscriberId, subscriberCommand.channels)
if subscriber, found := h.subscribers[subscriberCommand.subscriberId]; found == true {
h.addChannelsToSubscriber(subscriberCommand.channels, subscriber)
subscriberCommand.responseListener <- *subscriber
} else {
subscriberCommand.responseListener <- Subscriber{}
}
case UnsubscribeFromChannels:
l.If("subscribers process - %s - unsubscribe from channels", subscriberCommand.subscriberId, subscriberCommand.channels)
if subscriber, found := h.subscribers[subscriberCommand.subscriberId]; found == true {
h.removeChannelsFromSubscriber(subscriberCommand.channels, subscriber)
subscriberCommand.responseListener <- *subscriber
} else {
subscriberCommand.responseListener <- Subscriber{}
}
case CleanupSubscribers:
var cleanupStartTime = time.Now().Unix()
for id, subscriber := range h.subscribers {
if cleanupStartTime-subscriber.lastRequest > secondsToKeepSubscriberAlive {
l.If("subscribers process - found dead subscriber %s", id)
h.deleteSubscriber(id)
}
}
}
case <-time.After(30 * time.Second):
l.If("subscribers process - alive")
}
}
l.I("subscribers process - stopped")
}
func (h *Hub) onServeFileRequest(m DataMediator, file string) {
b, err := ioutil.ReadFile("web/" + file)
if err != nil {
l.Wf("file not found %s", "web/"+file)
}
if err == nil {
l.Df("found file %s", file)
m.WriteResponse(string(b), "plain")
}
}
func (m *WebSocketHandler) reader() {
l.I("wsreader process - starting")
var subscriberId string = "anonymous"
for {
var message string
err := websocket.Message.Receive(m.ws, &message)
if err != nil {
l.If("wsreader process - %s - error reading from socket: %s", subscriberId, err.Error())
break
}
l.If("wsreader process - read from socket %s", string(message))
var command = new(WebSocketCommand)
err = json.Unmarshal([]byte(message), command)
if err != nil {
l.Ef("wsreader process - %s - error unmarshal commad %s", subscriberId, err.Error())
break
}
var mediator = WebSocketDataMediator{send: m.send, command: *command, RequestId: command.RequestId}
// special commands - keep alive and subscribe
if command.Command == "keepAlive" {
var subscriber = m.hub.subscribers[m.subscriber.id]
// subscriber not found
if subscriber == nil {
l.Wf("wsreader process - %s - timed out!", subscriberId)
break
} else {
subscriber.lastRequest = time.Now().Unix()
}
} else if command.Command == "subscribe" {
var channels = strings.Split(mediator.ReadParameter("channels"), ",")
var responseListener = make(chan Subscriber)
m.hub.subscriberCommandListener <- HubSubscriberRequest{command: Subscribe, channels: channels, responseListener: responseListener}
m.subscriber = <-responseListener
subscriberId = m.subscriber.id
go m.writer()
mediator.WriteResponse(map[string]interface{}{"command": "subscribe", "subscriberId": m.subscriber.id}, "json")
close(responseListener)
} else {
m.hub.route(command.Command, &mediator)
}
}
m.closeListener <- true
l.If("wsreader process - %s - stopped", subscriberId)
m.ws.Close()
}
func main() {
path, err := os.Getwd()
if err != nil {
panic(err)
}
l.If("current app path: %s", path)
var processes = runtime.NumCPU()
runtime.GOMAXPROCS(processes)
l.If("using processes %d", processes)
l.I("server started.")
restartLisnener := make(chan string)
hub := comet.NewHub()
for {
go httpServerProcess(hub, restartLisnener)
reason := <-restartLisnener
l.Wf("web server restarted: %s", reason)
}
}