Channel-based bspwm communication

1 files changed, 39 insertions, 27 deletions

diff --git a/bspc/bspc.go b/bspc/bspc.go
index 568919e..f3b7ff3 100644
--- a/bspc/bspc.go
+++ b/bspc/bspc.go
@@ -63,11 +63,19 @@ func LoadState() (*State, error) {
 }
 
 type Subscriber struct {
+	Event   chan *Event
+	cleanup chan bool
 	cmd     *exec.Cmd
 	pipe    io.ReadCloser
 	scanner *bufio.Scanner
 }
 
+type Event struct {
+	Err	error
+	Name	string
+	Tokens	[]string
+}
+
 func Subscribe() (*Subscriber, error) {
 	cmd := exec.Command("bspc", "subscribe", "all")
 
@@ -80,20 +88,35 @@ func Subscribe() (*Subscriber, error) {
 		return nil, common.Perror("cmd.Start", err)
 	}
 
-	var ret Subscriber
-	ret.cmd     = cmd
-	ret.pipe    = pipe
-	ret.scanner = bufio.NewScanner(ret.pipe)
-
-	return &ret, nil
+	var s Subscriber
+	s.Event   = make(chan *Event)
+	s.cleanup = make(chan bool)
+	s.cmd     = cmd
+	s.pipe    = pipe
+	s.scanner = bufio.NewScanner(s.pipe)
+
+	go func() {
+		for {
+			select {
+			case <- s.cleanup:
+				s.cmd.Wait()
+				return
+			default:
+				if event := s.get(); event != nil {
+					s.Event <- event
+				}
+			}
+		}
+	}()
+
+	return &s, nil
 }
 
-type Event struct {
-	Name	string
-	Tokens	[]string
+func (s *Subscriber) Close() {
+	s.cleanup <- true
 }
 
-func (s *Subscriber) GetLine() (string, error) {
+func (s *Subscriber) getLine() (string, error) {
 	if s.scanner.Scan() {
 		return s.scanner.Text(), nil
 	}
@@ -105,29 +128,18 @@ func (s *Subscriber) GetLine() (string, error) {
 	return "", nil
 }
 
-func (s *Subscriber) Get() (*Event, error) {
+func (s *Subscriber) get() (*Event) {
 	var line string
 	var err  error
 	for {
-		line, err = s.GetLine()
+		line, err = s.getLine()
 		if line[0] != 'W' { break }
 	}
 
-	if err != nil { return nil, err }
-	if line == "" { return nil, nil }
-	
-	name, tokens, found := strings.Cut(line, " ")
+	if line == "" { return nil }
+	if err != nil { return &Event{err, "", nil} }
 
-	var event Event
-	event.Name   = name
-	event.Tokens = strings.Split(tokens, " ")
-
-	// We do not found. Shut up, compiler.
-	found = !found
-
-	return &event, nil
-}
+	name, tokens, _ := strings.Cut(line, " ")
 
-func (s *Subscriber) Close() error {
-	return s.cmd.Wait()
+	return &Event{nil, name, strings.Split(tokens, " ")}
 }