fix memory leak by using a fixed size buffer pool

gumbleopenal/stream.go

@@ -13,7 +13,14 @@ var (
 	ErrState = errors.New("gumbleopenal: invalid state")
 )
 
+type Config struct {
+	Deafen bool
+	Mute   bool
+}
+
 type Stream struct {
+	Config Config
+
 	client *gumble.Client
 	link   gumble.Detacher
 
@@ -25,25 +32,41 @@ type Stream struct {
 	contextSink *openal.Context
 }
 
-func New(client *gumble.Client) (*Stream, error) {
+func Setup(client *gumble.Client, conf Config) (*Stream, error) {
 	s := &Stream{
+		Config:          conf,
 		client:          client,
 		sourceFrameSize: client.Config.AudioFrameSize(),
 	}
 
-	s.deviceSource = openal.CaptureOpenDevice("", gumble.AudioSampleRate, openal.FormatMono16, uint32(s.sourceFrameSize))
+	if !conf.Mute {
+		s.deviceSource = openal.CaptureOpenDevice("", gumble.AudioSampleRate, openal.FormatMono16, uint32(s.sourceFrameSize))
+		s.StartSource()
+	}
 
-	s.deviceSink = openal.OpenDevice("")
-	s.contextSink = s.deviceSink.CreateContext()
-	s.contextSink.Activate()
+	if !conf.Deafen {
+		s.deviceSink = openal.OpenDevice("")
+		s.contextSink = s.deviceSink.CreateContext()
+		s.contextSink.Activate()
 
-	s.link = client.Config.AttachAudio(s)
+		s.link = client.Config.AttachAudio(s)
+	}
 
 	return s, nil
 }
 
+func New(client *gumble.Client) (*Stream, error) {
+	s, err := Setup(client, Config{Mute: true, Deafen: false})
+	if err == nil {
+		s.deviceSource = openal.CaptureOpenDevice("", gumble.AudioSampleRate, openal.FormatMono16, uint32(s.sourceFrameSize))
+	}
+	return s, err
+}
+
 func (s *Stream) Destroy() {
-	s.link.Detach()
+	if s.link != nil {
+		s.link.Detach()
+	}
 	if s.deviceSource != nil {
 		s.StopSource()
 		s.deviceSource.CaptureCloseDevice()
@@ -80,6 +103,14 @@ func (s *Stream) StopSource() error {
 func (s *Stream) OnAudioStream(e *gumble.AudioStreamEvent) {
 	go func() {
 		source := openal.NewSource()
+		emptyBufs := openal.NewBuffers(8)
+		reclaim := func() {
+			if n := source.BuffersProcessed(); n > 0 {
+				reclaimedBufs := make(openal.Buffers, n)
+				source.UnqueueBuffers(reclaimedBufs)
+				emptyBufs = append(emptyBufs, reclaimedBufs...)
+			}
+		}
 		var raw [gumble.AudioMaximumFrameSize * 2]byte
 		for packet := range e.C {
 			samples := len(packet.AudioBuffer)
@@ -89,19 +120,21 @@ func (s *Stream) OnAudioStream(e *gumble.AudioStreamEvent) {
 			for i, value := range packet.AudioBuffer {
 				binary.LittleEndian.PutUint16(raw[i*2:], uint16(value))
 			}
-			for source.BuffersProcessed() > 0 {
-				source.UnqueueBuffer().Delete()
+			reclaim()
+			if len(emptyBufs) == 0 {
+				continue
 			}
-			buffer := openal.NewBuffer()
+			last := len(emptyBufs) - 1
+			buffer := emptyBufs[last]
+			emptyBufs = emptyBufs[:last]
 			buffer.SetData(openal.FormatMono16, raw[:samples*2], gumble.AudioSampleRate)
 			source.QueueBuffer(buffer)
 			if source.State() != openal.Playing {
 				source.Play()
 			}
 		}
-		for source.BuffersProcessed() > 0 {
-			source.UnqueueBuffer().Delete()
-		}
+		reclaim()
+		emptyBufs.Delete()
 		source.Delete()
 	}()
 }