// watch runs a Watch RPC and prints the result stream.
func watch(client pb.GoogleClient, query string) {
ctx, cancel := context.WithCancel(context.Background())
defer cancel()
req := &pb.Request{Query: query} // HL
stream, err := client.Watch(ctx, req) // HL
if err != nil {
log.Fatal(err)
}
for {
res, err := stream.Recv() // HL
if err == io.EOF { // HL
fmt.Println("and now your watch is ended")
return
}
if err != nil {
log.Fatal(err)
}
fmt.Println(res) // HL
}
}
// watchBackend runs Watch on a single backend and sends results on c.
// watchBackend returns when ctx.Done is closed or stream.Recv fails.
func watchBackend(ctx context.Context, backend pb.GoogleClient, req *pb.Request, c chan<- result) {
stream, err := backend.Watch(ctx, req) // HL
if err != nil {
select {
case c <- result{err: err}: // HL
case <-ctx.Done():
}
return
}
for {
res, err := stream.Recv() // HL
select {
case c <- result{res, err}: // HL
if err != nil {
return
}
case <-ctx.Done():
return
}
}
}