func (f *impl) Link(ctx *context.T, sc ifc.BridgeLinkServerCall, topics []ifc.Topic) error {
ctx.Info("Link for topics ", topics)
done := make(chan error, 2)
cc, mu, err := mqttConnect()
if err != nil {
return err
}
// transmitter: do mqtt subscribe, then copy messages to output stream
go func() {
done <- transmitter(topics, sc.SendStream(), cc, mu)
}()
// receiver: read the input stream and copy to mqtt via cc.Publish
go func() {
done <- receiver(sc.RecvStream(), cc, mu)
}()
err = <-done
// Stop sender by closing cc.Incoming
cc.Disconnect()
return err
}
// AllFunc runs a server, advertises it, scans for other servers and makes an
// Echo RPC to every advertised remote server.
func AllFunc(ctx *context.T, output io.Writer) error {
ls := rpc.ListenSpec{Proxy: "proxy"}
addRegisteredProto(&ls, "tcp", ":0")
addRegisteredProto(&ls, "bt", "/0")
fmt.Fprintf(output, "Listening on: %+v (and proxy)\n", ls.Addrs)
ctx, server, err := v23.WithNewServer(
v23.WithListenSpec(ctx, ls),
mountName(ctx, "all"),
&echoServer{},
security.AllowEveryone())
if err != nil {
return err
}
ad := &discovery.Advertisement{
InterfaceName: interfaceName,
Attributes: discovery.Attributes{
"Hello": "There",
},
}
d, err := v23.NewDiscovery(ctx)
if err != nil {
return err
}
stoppedAd, err := libdiscovery.AdvertiseServer(ctx, d, server, "", ad, nil)
if err != nil {
return err
}
updates, err := d.Scan(ctx, "v.InterfaceName=\""+interfaceName+"\"")
if err != nil {
return err
}
var (
status = server.Status()
counter = 0
peerByAdId = make(map[discovery.AdId]*peer)
lastCall = make(map[discovery.AdId]time.Time)
callResults = make(chan string)
activeCalls = 0
quit = false
myaddrs = serverAddrs(status)
ticker = time.NewTicker(time.Second)
call = func(p *peer) {
counter++
activeCalls++
lastCall[p.adId] = time.Now()
go func(msg string) {
summary, err := p.call(ctx, msg)
if err != nil {
ctx.Infof("Failed to call [%v]: %v", p.description, err)
callResults <- ""
return
}
callResults <- summary
}(fmt.Sprintf("Hello #%d", counter))
}
statRequest = make(chan chan<- string)
)
defer ticker.Stop()
stats.NewStringFunc(vangoStat, func() string {
r := make(chan string)
statRequest <- r
return <-r
})
defer stats.Delete(vangoStat)
fmt.Fprintln(output, "My AdID:", ad.Id)
fmt.Fprintln(output, "My addrs:", myaddrs)
ctx.Infof("SERVER STATUS: %+v", status)
for !quit {
select {
case <-ctx.Done():
quit = true
case <-status.Dirty:
status = server.Status()
newaddrs := serverAddrs(status)
changed := len(newaddrs) != len(myaddrs)
if !changed {
for i := range newaddrs {
if newaddrs[i] != myaddrs[i] {
changed = true
break
}
}
}
if changed {
myaddrs = newaddrs
fmt.Fprintln(output, "My addrs:", myaddrs)
}
ctx.Infof("SERVER STATUS: %+v", status)
case u, scanning := <-updates:
if !scanning {
fmt.Fprintln(output, "SCANNING STOPPED")
quit = true
break
}
if u.IsLost() {
if p, ok := peerByAdId[u.Id()]; ok {
fmt.Fprintln(output, "LOST:", p.description)
}
delete(peerByAdId, u.Id())
delete(lastCall, u.Id())
break
}
p, err := newPeer(ctx, u)
if err != nil {
ctx.Info(err)
break
}
peerByAdId[p.adId] = p
fmt.Fprintln(output, "FOUND:", p.description)
call(p)
case r := <-callResults:
activeCalls--
if len(r) > 0 {
fmt.Fprintln(output, r)
}
case <-stoppedAd:
fmt.Fprintln(output, "STOPPED ADVERTISING")
stoppedAd = nil
case <-ticker.C:
// Call all peers that haven't been called in a while
now := time.Now()
for id, t := range lastCall {
if now.Sub(t) > rpcTimeout {
call(peerByAdId[id])
}
}
case s := <-statRequest:
idx := 1
ret := new(bytes.Buffer)
fmt.Fprintln(ret, "ACTIVE CALLS:", activeCalls)
fmt.Fprintln(ret, "PEERS")
for id, p := range peerByAdId {
fmt.Fprintf(ret, "%2d) %s -- %v\n", idx, p.description, lastCall[id])
}
s <- ret.String()
}
}
fmt.Println(output, "EXITING: Cleaning up")
for activeCalls > 0 {
<-callResults
activeCalls--
}
// Exhaust the scanned updates queue.
// (The channel will be closed as a by-product of the context being Done).
for range updates {
}
fmt.Fprintln(output, "EXITING: Done")
return nil
}