// The core ZeroMQ messaging loop. Handles requests and responses
// asynchronously using the router socket. Every request is delegated to
// a goroutine for maximum concurrency.
//
// `gozmq` does currently not support copy-free messages/frames. This
// means that every message passing through this function needs to be
// copied in-memory. If this becomes a bottleneck in the future,
// multiple router sockets can be hooked to this final router to scale
// message copying.
//
// TODO: Make this a type function of `Server` to remove a lot of
// parameters.
func loopServer(estore *eventstore.EventStore, evpubsock, frontend zmq.Socket,
stop chan bool) {
toPoll := zmq.PollItems{
zmq.PollItem{Socket: &frontend, zmq.Events: zmq.POLLIN},
}
pubchan := make(chan eventstore.StoredEvent)
estore.RegisterPublishedEventsChannel(pubchan)
go publishAllSavedEvents(pubchan, evpubsock)
defer close(pubchan)
pollchan := make(chan zmqPollResult)
respchan := make(chan zMsg)
pollCancel := make(chan bool)
defer stopPoller(pollCancel)
go asyncPoll(pollchan, toPoll, pollCancel)
for {
select {
case res := <-pollchan:
if res.err != nil {
log.Println("Could not poll:", res.err)
}
if res.err == nil && toPoll[0].REvents&zmq.POLLIN != 0 {
msg, _ := toPoll[0].Socket.RecvMultipart(0)
zmsg := zMsg(msg)
go handleRequest(respchan, estore, zmsg)
}
go asyncPoll(pollchan, toPoll, pollCancel)
case frames := <-respchan:
if err := frontend.SendMultipart(frames, 0); err != nil {
log.Println(err)
}
case <-stop:
log.Println("Server asked to stop. Stopping...")
return
}
}
}
