func serveWebsocketIO(
ws *websocket.Conn,
portal binder.Portal,
timeout time.Duration,
logger log.Modular,
stats metrics.Aggregator,
) {
defer portal.Exit(timeout)
// Signal to close
var incomingCloseInt uint32
outgoingCloseChan := make(chan struct{})
// Signals that goroutine is closing
incomingClosedChan := make(chan struct{})
outgoingClosedChan := make(chan struct{})
// Loop incoming messages.
go func() {
var err error
defer func() {
if err != nil {
websocket.JSON.Send(ws, leapSocketServerMessage{
Type: "error",
Error: err.Error(),
})
}
close(incomingClosedChan)
}()
for atomic.LoadUint32(&incomingCloseInt) == 0 {
var msg leapSocketClientMessage
if socketErr := websocket.JSON.Receive(ws, &msg); socketErr != nil {
return
}
switch msg.Command {
case "submit":
if msg.Transform == nil {
err = errors.New("submit error: transform was nil")
return
}
var ver int
if ver, err = portal.SendTransform(*msg.Transform, timeout); err != nil {
return
}
websocket.JSON.Send(ws, leapSocketServerMessage{
Type: "correction",
Version: ver,
})
case "update":
if msg.Position != nil || len(msg.Message) > 0 {
portal.SendMessage(binder.Message{
Content: msg.Message,
Position: msg.Position,
Active: true,
})
}
case "ping":
// Do nothing
default:
err = errors.New("command not recognised")
}
}
}()
// Loop outgoing messages.
go func() {
defer close(outgoingClosedChan)
for {
select {
case <-outgoingCloseChan:
return
case tform, open := <-portal.TransformReadChan():
if !open {
return
}
websocket.JSON.Send(ws, leapSocketServerMessage{
Type: "transforms",
Transforms: []text.OTransform{tform},
})
case msg, open := <-portal.UpdateReadChan():
if !open {
return
}
websocket.JSON.Send(ws, leapSocketServerMessage{
Type: "update",
Updates: []binder.ClientUpdate{msg},
})
}
}
}()
// If one channel closes, close the other, if the socket is being closed then close both.
select {
case <-incomingClosedChan:
close(outgoingCloseChan)
<-outgoingClosedChan
portal.SendMessage(binder.Message{
Active: false,
})
case <-outgoingClosedChan:
atomic.StoreUint32(&incomingCloseInt, 1)
<-incomingClosedChan
portal.SendMessage(binder.Message{
Active: false,
})
}
}
