Rethinking the beep.Streamer interfaces

examples/doppler-stereo-room/main.go

@@ -8,6 +8,7 @@ import (
 	"unicode"
 
 	"github.com/gdamore/tcell/v2"
+
 	"github.com/gopxl/beep"
 	"github.com/gopxl/beep/effects"
 	"github.com/gopxl/beep/mp3"
@@ -157,15 +158,17 @@ func main() {
 		fmt.Fprintf(os.Stderr, "Usage: %s song.mp3\n", os.Args[0])
 		os.Exit(1)
 	}
+
 	f, err := os.Open(os.Args[1])
 	if err != nil {
 		report(err)
 	}
+	defer f.Close()
+
 	streamer, format, err := mp3.Decode(f)
 	if err != nil {
 		report(err)
 	}
-	defer streamer.Close()
 
 	speaker.Init(format.SampleRate, format.SampleRate.N(time.Second/30))
 

examples/midi/main.go

@@ -24,6 +24,8 @@ func main() {
 	if err != nil {
 		log.Fatal(err)
 	}
+	defer soundFontFile.Close()
+
 	soundFont, err := midi.NewSoundFont(soundFontFile)
 	if err != nil {
 		log.Fatal(err)
@@ -34,6 +36,8 @@ func main() {
 	if err != nil {
 		log.Fatal(err)
 	}
+	defer midiFile.Close()
+
 	s, format, err := midi.Decode(midiFile, soundFont, sampleRate)
 	if err != nil {
 		log.Fatal(err)

examples/speedy-player/main.go

@@ -156,15 +156,17 @@ func main() {
 		fmt.Fprintf(os.Stderr, "Usage: %s song.mp3\n", os.Args[0])
 		os.Exit(1)
 	}
+
 	f, err := os.Open(os.Args[1])
 	if err != nil {
 		report(err)
 	}
+	defer f.Close()
+
 	streamer, format, err := mp3.Decode(f)
 	if err != nil {
 		report(err)
 	}
-	defer streamer.Close()
 
 	speaker.Init(format.SampleRate, format.SampleRate.N(time.Second/30))
 

examples/tutorial/1-hello-beep/a/main.go

@@ -15,12 +15,12 @@ func main() {
 	if err != nil {
 		log.Fatal(err)
 	}
+	defer f.Close()
 
 	streamer, format, err := mp3.Decode(f)
 	if err != nil {
 		log.Fatal(err)
 	}
-	defer streamer.Close()
 
 	speaker.Init(format.SampleRate, format.SampleRate.N(time.Second/10))
 

examples/tutorial/1-hello-beep/b/main.go

@@ -15,12 +15,12 @@ func main() {
 	if err != nil {
 		log.Fatal(err)
 	}
+	defer f.Close()
 
 	streamer, format, err := mp3.Decode(f)
 	if err != nil {
 		log.Fatal(err)
 	}
-	defer streamer.Close()
 
 	sr := format.SampleRate * 2
 	speaker.Init(sr, sr.N(time.Second/10))

examples/tutorial/2-composing-and-controlling/a/main.go

@@ -16,12 +16,12 @@ func main() {
 	if err != nil {
 		log.Fatal(err)
 	}
+	defer f.Close()
 
 	streamer, format, err := mp3.Decode(f)
 	if err != nil {
 		log.Fatal(err)
 	}
-	defer streamer.Close()
 
 	speaker.Init(format.SampleRate, format.SampleRate.N(time.Second/10))
 

examples/tutorial/2-composing-and-controlling/b/main.go

@@ -16,12 +16,12 @@ func main() {
 	if err != nil {
 		log.Fatal(err)
 	}
+	defer f.Close()
 
 	streamer, format, err := mp3.Decode(f)
 	if err != nil {
 		log.Fatal(err)
 	}
-	defer streamer.Close()
 
 	speaker.Init(format.SampleRate, format.SampleRate.N(time.Second/10))
 

examples/tutorial/2-composing-and-controlling/c/main.go

@@ -16,12 +16,12 @@ func main() {
 	if err != nil {
 		log.Fatal(err)
 	}
+	defer f.Close()
 
 	streamer, format, err := mp3.Decode(f)
 	if err != nil {
 		log.Fatal(err)
 	}
-	defer streamer.Close()
 
 	speaker.Init(format.SampleRate, format.SampleRate.N(time.Second/10))
 

examples/tutorial/2-composing-and-controlling/d/main.go

@@ -17,12 +17,12 @@ func main() {
 	if err != nil {
 		log.Fatal(err)
 	}
+	defer f.Close()
 
 	streamer, format, err := mp3.Decode(f)
 	if err != nil {
 		log.Fatal(err)
 	}
-	defer streamer.Close()
 
 	speaker.Init(format.SampleRate, format.SampleRate.N(time.Second/10))
 

examples/tutorial/3-to-buffer-or-not-to-buffer/main.go

@@ -26,7 +26,7 @@ func main() {
 
 	buffer := beep.NewBuffer(format)
 	buffer.Append(streamer)
-	streamer.Close()
+	f.Close()
 
 	for {
 		fmt.Print("Press [ENTER] to fire a gunshot! ")

flac/decode.go

@@ -10,20 +10,10 @@ import (
 	"github.com/gopxl/beep"
 )
 
-// Decode takes a Reader containing audio data in FLAC format and returns a StreamSeekCloser,
+// Decode takes an io.Reader containing audio data in FLAC format and returns a StreamSeeker,
 // which streams that audio. The Seek method will panic if r is not io.Seeker.
-//
-// Do not close the supplied Reader, instead, use the Close method of the returned
-// StreamSeekCloser when you want to release the resources.
-func Decode(r io.Reader) (s beep.StreamSeekCloser, format beep.Format, err error) {
+func Decode(r io.Reader) (s beep.StreamSeeker, format beep.Format, err error) {
 	d := decoder{r: r}
-	defer func() { // hacky way to always close r if an error occurred
-		if closer, ok := d.r.(io.Closer); ok {
-			if err != nil {
-				closer.Close()
-			}
-		}
-	}()
 
 	rs, seeker := r.(io.ReadSeeker)
 	if seeker {
@@ -161,13 +151,3 @@ func (d *decoder) Seek(p int) error {
 	d.pos = int(pos)
 	return err
 }
-
-func (d *decoder) Close() error {
-	if closer, ok := d.r.(io.Closer); ok {
-		err := closer.Close()
-		if err != nil {
-			return errors.Wrap(err, "flac")
-		}
-	}
-	return nil
-}

interface.go

@@ -62,25 +62,6 @@ type StreamSeeker interface {
 	Seek(p int) error
 }
 
-// StreamCloser is a Streamer streaming from a resource which needs to be released, such as a file
-// or a network connection.
-type StreamCloser interface {
-	Streamer
-
-	// Close closes the Streamer and releases it's resources. Streamer will no longer stream any
-	// samples.
-	Close() error
-}
-
-// StreamSeekCloser is a union of StreamSeeker and StreamCloser.
-type StreamSeekCloser interface {
-	Streamer
-	Len() int
-	Position() int
-	Seek(p int) error
-	Close() error
-}
-
 // StreamerFunc is a Streamer created by simply wrapping a streaming function (usually a closure,
 // which encloses a time tracking variable). This sometimes simplifies creating new streamers.
 //

midi/decode.go

@@ -17,29 +17,21 @@ const (
 )
 
 // NewSoundFont reads a sound font containing instruments. A sound font is required in order to play MIDI files.
-//
-// NewSoundFont closes the supplied ReadCloser.
-func NewSoundFont(r io.ReadCloser) (*SoundFont, error) {
+func NewSoundFont(r io.Reader) (*SoundFont, error) {
 	sf, err := meltysynth.NewSoundFont(r)
 	if err != nil {
 		return nil, err
 	}
-	err = r.Close()
-	if err != nil {
-		return nil, err
-	}
 	return &SoundFont{sf}, nil
 }
 
 type SoundFont struct {
 	sf *meltysynth.SoundFont
 }
 
-// Decode takes a ReadCloser containing audio data in MIDI format and a SoundFont to synthesize the sounds
+// Decode takes an io.Reader containing audio data in MIDI format and a SoundFont to synthesize the sounds
 // and returns a beep.StreamSeeker, which streams the audio.
-//
-// Decode closes the supplied ReadCloser.
-func Decode(rc io.ReadCloser, sf *SoundFont, sampleRate beep.SampleRate) (s beep.StreamSeeker, format beep.Format, err error) {
+func Decode(r io.Reader, sf *SoundFont, sampleRate beep.SampleRate) (s beep.StreamSeeker, format beep.Format, err error) {
 	defer func() {
 		if err != nil {
 			err = errors.Wrap(err, "midi")
@@ -52,11 +44,7 @@ func Decode(rc io.ReadCloser, sf *SoundFont, sampleRate beep.SampleRate) (s beep
 		return nil, beep.Format{}, err
 	}
 
-	mf, err := meltysynth.NewMidiFile(rc)
-	if err != nil {
-		return nil, beep.Format{}, err
-	}
-	err = rc.Close()
+	mf, err := meltysynth.NewMidiFile(r)
 	if err != nil {
 		return nil, beep.Format{}, err
 	}

mp3/decode.go

@@ -5,9 +5,10 @@ import (
 	"fmt"
 	"io"
 
-	"github.com/gopxl/beep"
 	gomp3 "github.com/hajimehoshi/go-mp3"
 	"github.com/pkg/errors"
+
+	"github.com/gopxl/beep"
 )
 
 const (
@@ -16,18 +17,15 @@ const (
 	gomp3BytesPerFrame = gomp3NumChannels * gomp3Precision
 )
 
-// Decode takes a ReadCloser containing audio data in MP3 format and returns a StreamSeekCloser,
+// Decode takes an io.Reader containing audio data in MP3 format and returns a StreamSeeker,
 // which streams that audio. The Seek method will panic if rc is not io.Seeker.
-//
-// Do not close the supplied ReadSeekCloser, instead, use the Close method of the returned
-// StreamSeekCloser when you want to release the resources.
-func Decode(rc io.ReadCloser) (s beep.StreamSeekCloser, format beep.Format, err error) {
+func Decode(r io.Reader) (s beep.StreamSeeker, format beep.Format, err error) {
 	defer func() {
 		if err != nil {
 			err = errors.Wrap(err, "mp3")
 		}
 	}()
-	d, err := gomp3.NewDecoder(rc)
+	d, err := gomp3.NewDecoder(r)
 	if err != nil {
 		return nil, beep.Format{}, err
 	}
@@ -36,15 +34,14 @@ func Decode(rc io.ReadCloser) (s beep.StreamSeekCloser, format beep.Format, err
 		NumChannels: gomp3NumChannels,
 		Precision:   gomp3Precision,
 	}
-	return &decoder{rc, d, format, 0, nil}, format, nil
+	return &decoder{d, format, 0, nil}, format, nil
 }
 
 type decoder struct {
-	closer io.Closer
-	d      *gomp3.Decoder
-	f      beep.Format
-	pos    int
-	err    error
+	d   *gomp3.Decoder
+	f   beep.Format
+	pos int
+	err error
 }
 
 func (d *decoder) Stream(samples [][2]float64) (n int, ok bool) {
@@ -94,11 +91,3 @@ func (d *decoder) Seek(p int) error {
 	d.pos = p * gomp3BytesPerFrame
 	return nil
 }
-
-func (d *decoder) Close() error {
-	err := d.closer.Close()
-	if err != nil {
-		return errors.Wrap(err, "mp3")
-	}
-	return nil
-}

vorbis/decode.go

@@ -14,18 +14,15 @@ const (
 	govorbisPrecision = 2
 )
 
-// Decode takes a ReadCloser containing audio data in ogg/vorbis format and returns a StreamSeekCloser,
+// Decode takes an io.Reader containing audio data in ogg/vorbis format and returns a StreamSeeker,
 // which streams that audio. The Seek method will panic if rc is not io.Seeker.
-//
-// Do not close the supplied ReadSeekCloser, instead, use the Close method of the returned
-// StreamSeekCloser when you want to release the resources.
-func Decode(rc io.ReadCloser) (s beep.StreamSeekCloser, format beep.Format, err error) {
+func Decode(r io.Reader) (s beep.StreamSeeker, format beep.Format, err error) {
 	defer func() {
 		if err != nil {
 			err = errors.Wrap(err, "ogg/vorbis")
 		}
 	}()
-	d, err := oggvorbis.NewReader(rc)
+	d, err := oggvorbis.NewReader(r)
 	if err != nil {
 		return nil, beep.Format{}, err
 	}
@@ -41,14 +38,13 @@ func Decode(rc io.ReadCloser) (s beep.StreamSeekCloser, format beep.Format, err
 		Precision:   govorbisPrecision,
 	}
 
-	return &decoder{rc, d, make([]float32, d.Channels()), nil}, format, nil
+	return &decoder{d, make([]float32, d.Channels()), nil}, format, nil
 }
 
 type decoder struct {
-	closer io.Closer
-	d      *oggvorbis.Reader
-	tmp    []float32
-	err    error
+	d   *oggvorbis.Reader
+	tmp []float32
+	err error
 }
 
 func (d *decoder) Stream(samples [][2]float64) (n int, ok bool) {
@@ -123,11 +119,3 @@ func (d *decoder) Seek(p int) error {
 	}
 	return nil
 }
-
-func (d *decoder) Close() error {
-	err := d.closer.Close()
-	if err != nil {
-		return errors.Wrap(err, "ogg/vorbis")
-	}
-	return nil
-}