Make the jukebox less of a heap

server/ctrlsubsonic/handlers_common.go

@@ -348,17 +348,14 @@ func (c *Controller) ServeJukebox(r *http.Request) *spec.Response {
 		c.Jukebox.Start()
 	case "skip":
 		index, err := params.GetInt("index")
-		var skipCurrent bool
 		if err != nil {
-			skipCurrent = true
+			return spec.NewError(10, "please provide an index for skip actions")
 		}
-		c.Jukebox.Skip(index, skipCurrent)
+		c.Jukebox.Skip(index)
 	case "get":
 		sub := spec.NewResponse()
 		sub.JukeboxPlaylist = c.Jukebox.GetTracks()
 		return sub
-	default:
-		return spec.NewError(10, "unknown value `%s` for parameter 'action'", act)
 	}
 	// all actions except get are expected to return a status
 	sub := spec.NewResponse()

server/jukebox/jukebox.go

@@ -29,18 +29,42 @@ type Jukebox struct {
 	playing   bool
 	sr        beep.SampleRate
 	// used to notify the player to re read the members
-	updates chan struct{}
+	updates chan update
 	quit    chan struct{}
 	done    chan bool
 	info    *strmInfo
+	speaker chan updateSpeaker
 	sync.Mutex
 }
 
+type updateType string
+
+const (
+	set    updateType = "set"
+	clear  updateType = "clear"
+	skip   updateType = "skip"
+	add    updateType = "add"
+	remove updateType = "remove"
+	stop   updateType = "stop"
+	start  updateType = "start"
+)
+
+type update struct {
+	action updateType
+	index  int
+	tracks []*db.Track
+}
+
+type updateSpeaker struct {
+	index int
+}
+
 func New(musicPath string) *Jukebox {
 	return &Jukebox{
 		musicPath: musicPath,
 		sr:        beep.SampleRate(48000),
-		updates:   make(chan struct{}),
+		updates:   make(chan update),
+		speaker:   make(chan updateSpeaker, 1),
 		done:      make(chan bool),
 		quit:      make(chan struct{}),
 	}
@@ -54,8 +78,10 @@ func (j *Jukebox) Listen() error {
 		select {
 		case <-j.quit:
 			return nil
-		case <-j.updates:
+		case update := <-j.updates:
-			j.doUpdate()
+			j.doUpdate(update)
+		case speaker := <-j.speaker:
+			j.doUpdateSpeaker(speaker)
 		}
 	}
 }
@@ -64,40 +90,76 @@ func (j *Jukebox) Quit() {
 	j.quit <- struct{}{}
 }
 
-func (j *Jukebox) doUpdate() {
+func (j *Jukebox) doUpdate(u update) {
-	var streamer beep.Streamer
-	var format beep.Format
-	if j.index >= len(j.playlist) {
 	j.Lock()
-		j.index = 0
+	switch u.action {
-		j.playing = false
+	case set:
+		if j.playing {
+			speaker.Clear()
+		}
+		speaker.Clear()
+		if len(u.tracks) == 0 {
+			j.playlist = []*db.Track{}
 			j.Unlock()
 			return
 		}
-	j.Lock()
+		j.playlist = u.tracks
+		j.index = 0
+		j.playing = true
+		j.Unlock()
+		j.speaker <- updateSpeaker{j.index}
+	case clear:
+		speaker.Clear()
+		j.playing = false
+		j.playlist = []*db.Track{}
+		j.Unlock()
+	case skip:
+		speaker.Clear()
+		j.index = u.index
+		j.Unlock()
+		j.speaker <- updateSpeaker{j.index}
+	case add:
+		j.playlist = append(j.playlist, u.tracks...)
+	case remove:
+		if u.index < 0 || u.index > len(j.playlist) {
+			return
+		}
+		j.playlist = append(j.playlist[:u.index], j.playlist[u.index+1:]...)
+		j.Unlock()
+	case stop:
+		j.playing = false
+		j.info.ctrlStrmr.Paused = true
+		j.Unlock()
+	case start:
+		j.playing = true
+		j.info.ctrlStrmr.Paused = false
+		j.Unlock()
+	}
+}
+
+func (j *Jukebox) doUpdateSpeaker(su updateSpeaker) error {
+	if su.index > len(j.playlist)-1 {
+		j.playing = false
+		return nil
+	}
 	f, err := os.Open(path.Join(
 		j.musicPath,
-		j.playlist[j.index].RelPath(),
+		j.playlist[su.index].RelPath(),
 	))
-	j.Unlock()
 	if err != nil {
-		j.incIndex()
+		return err
-		return
 	}
-	switch j.playlist[j.index].Ext() {
+	var streamer beep.Streamer
+	var format beep.Format
+	switch j.playlist[su.index].Ext() {
 	case "mp3":
 		streamer, format, err = mp3.Decode(f)
 	case "flac":
 		streamer, format, err = flac.Decode(f)
-	default:
-		j.incIndex()
-		return
 	}
 	if err != nil {
-		j.incIndex()
+		return err
-		return
 	}
-	if j.playing {
 	j.Lock()
 	{
 		j.info = &strmInfo{}
@@ -110,79 +172,49 @@ func (j *Jukebox) doUpdate() {
 	}
 	j.Unlock()
 	speaker.Play(beep.Seq(&j.info.ctrlStrmr, beep.Callback(func() {
-			j.done <- false
+		j.speaker <- updateSpeaker{su.index + 1}
 	})))
-		if v := <-j.done; v {
+	return nil
-			return
-		}
-		j.Lock()
-		j.index++
-		if j.index >= len(j.playlist) {
-			j.index = 0
-			j.playing = false
-			j.Unlock()
-			return
-		}
-		j.Unlock()
-		// in a go routine as otherwise this hangs as the
-		go func() {
-			j.updates <- struct{}{}
-		}()
-	}
-}
-
-func (j *Jukebox) incIndex() {
-	j.Lock()
-	defer j.Unlock()
-	j.index++
 }
 
 func (j *Jukebox) SetTracks(tracks []*db.Track) {
-	j.Lock()
+	j.updates <- update{
-	defer j.Unlock()
+		action: set,
-	j.index = 0
+		tracks: tracks,
-	if len(tracks) == 0 {
-		if j.playing {
-			j.done <- true
 	}
-		j.playing = false
-		j.playlist = []*db.Track{}
-		speaker.Clear()
-		return
-	}
-	if j.playing {
-		j.playlist = tracks
-		j.done <- true
-		speaker.Clear()
-		j.updates <- struct{}{}
-		return
-	}
-	j.playlist = tracks
-	j.playing = true
-	j.updates <- struct{}{}
 }
 
 func (j *Jukebox) AddTracks(tracks []*db.Track) {
-	j.Lock()
+	j.updates <- update{
-	j.playlist = append(j.playlist, tracks...)
+		action: add,
-	j.Unlock()
+		tracks: tracks,
-}
+	}
-
-func (j *Jukebox) ClearTracks() {
-	j.Lock()
-	j.index = 0
-	j.playing = false
-	j.playlist = []*db.Track{}
-	j.Unlock()
 }
 
 func (j *Jukebox) RemoveTrack(i int) {
-	j.Lock()
+	j.updates <- update{
-	defer j.Unlock()
+		action: remove,
-	if i < 0 || i > len(j.playlist) {
+		index:  i,
-		return
 	}
-	j.playlist = append(j.playlist[:i], j.playlist[i+1:]...)
+}
+
+func (j *Jukebox) Skip(i int) {
+	j.updates <- update{
+		action: skip,
+		index:  i,
+	}
+}
+
+func (j *Jukebox) ClearTracks() {
+	j.updates <- update{action: clear}
+}
+
+func (j *Jukebox) Stop() {
+	j.updates <- update{action: stop}
+}
+
+func (j *Jukebox) Start() {
+	j.updates <- update{action: start}
 }
 
 func (j *Jukebox) Status() *spec.JukeboxStatus {
@@ -217,35 +249,3 @@ func (j *Jukebox) GetTracks() *spec.JukeboxPlaylist {
 	}
 	return jb
 }
-
-func (j *Jukebox) Stop() {
-	j.Lock()
-	j.playing = false
-	j.info.ctrlStrmr.Paused = true
-	j.Unlock()
-}
-
-func (j *Jukebox) Start() {
-	j.Lock()
-	j.playing = true
-	j.info.ctrlStrmr.Paused = false
-	j.Unlock()
-}
-
-func (j *Jukebox) Skip(i int, skipCurrent bool) {
-	j.Lock()
-	defer j.Unlock()
-	if i == j.index {
-		return
-	}
-	if skipCurrent {
-		j.index++
-	} else {
-		j.index = i
-	}
-	speaker.Clear()
-	if j.playing {
-		j.done <- true
-	}
-	j.updates <- struct{}{}
-}