In oggtag a prefix Ogg was removed from funtions and consts. Also added the consts that hold len of sequences.

pkg/oggtag/oggtag.go

@@ -13,11 +13,13 @@ import (
 )
 
 const bufferLength = 4096
-const OggMagicSequence = "OggS"
+const MagicSequence = "OggS"
-const OggVorbisSequence = "vorbis"
+const MagicSequenceLen = len(MagicSequence)
+const VorbisSequence = "vorbis"
+const VorbisSequenceLen = len(VorbisSequence)
 
 // OggReadFile returns a head of an OGG file, and a buffer contains last frame.
-func OggReadFile(path string) (buf_start, buf_end []byte, _ error) {
+func ReadFile(path string) (buf_start, buf_end []byte, _ error) {
 	f, err := os.Open(path)
 	if err != nil {
 		return nil, nil, err
@@ -49,7 +51,7 @@ func OggReadFile(path string) (buf_start, buf_end []byte, _ error) {
 			return nil, nil, err
 		}
 
-		if bytes.Contains(buf_end, []byte(OggMagicSequence)) {
+		if bytes.Contains(buf_end, []byte(MagicSequence)) {
 			break
 		}
 	}
@@ -63,7 +65,7 @@ func OggReadFile(path string) (buf_start, buf_end []byte, _ error) {
 // It is a simple implementation that doesn't parse a header and instead just
 // looking for a certain tag preceded with three zero bytes and ends with
 // an = character.
-func OggGetTag(buf []byte, tag string) string {
+func GetTag(buf []byte, tag string) string {
 	tagIdx := bytes.Index(buf, append([]byte{0, 0, 0}, (tag+"=")...))
 	if tagIdx == -1 {
 		tagIdx = bytes.Index(buf, append([]byte{0, 0, 0}, (strings.ToUpper(tag)+"=")...))
@@ -79,15 +81,15 @@ func OggGetTag(buf []byte, tag string) string {
 }
 
 // OggGetDuration returns song's duration in milliseconds.
-func OggGetDuration(buf_start, buf_end []byte) time.Duration {
+func GetDuration(buf_start, buf_end []byte) time.Duration {
-	rateIdx := bytes.Index(buf_start, []byte(OggVorbisSequence)) +
+	rateIdx := bytes.Index(buf_start, []byte(VorbisSequence)) +
-		len(OggVorbisSequence) + 5
+		VorbisSequenceLen + 5
 	rateBytes := buf_start[rateIdx : rateIdx+4]
 	rate := int32(rateBytes[0]) + int32(rateBytes[1])<<8 +
 		int32(rateBytes[2])<<16 + int32(rateBytes[3])<<24
 
-	granuleIdx := bytes.LastIndex(buf_end, []byte(OggMagicSequence)) +
+	granuleIdx := bytes.LastIndex(buf_end, []byte(MagicSequence)) +
-		len(OggMagicSequence) + 2
+		MagicSequenceLen + 2
 	granuleBytes := buf_end[granuleIdx : granuleIdx+8]
 	granule := int64(granuleBytes[0]) + int64(granuleBytes[1])<<8 +
 		int64(granuleBytes[2])<<16 + int64(granuleBytes[3])<<24 +

pkg/oggtag/oggtag_test.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"os"
 	"testing"
+	"time"
 )
 
 const bufferSize = 4096
@@ -11,54 +12,55 @@ const sampleSong = "/mnt/data/appdata/radio/fallback.ogg"
 const sampleArtist = "breskina"
 const sampleTitle = "Песня про мечты"
 
-func TestOggGetTag(t *testing.T) {
+func TestGetTag(t *testing.T) {
 	f, _ := os.Open(sampleSong)
 	buf := make([]byte, bufferSize)
 	f.Read(buf)
-	tag := OggGetTag(buf, "artist")
+	tag := GetTag(buf, "artist")
 	if tag != sampleArtist {
 		t.Error(tag, "!=", sampleArtist)
 	}
-	tag = OggGetTag(buf, "title")
+	tag = GetTag(buf, "title")
 	if tag != sampleTitle {
 		t.Error(tag, "!=", sampleTitle)
 	}
 }
 
-func BenchmarkOggGetTag(b *testing.B) {
+func BenchmarkGetTag(b *testing.B) {
 	f, _ := os.Open(sampleSong)
 	buf := make([]byte, bufferSize)
 	f.Read(buf)
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
-		OggGetTag(buf, "artist")
+		GetTag(buf, "artist")
 	}
 }
 
-func TestOggReadFile(t *testing.T) {
+func TestReadFile(t *testing.T) {
-	bs, bf, err := OggReadFile(sampleSong)
+	bs, bf, err := ReadFile(sampleSong)
 	if err != nil {
 		t.Error(err)
 	}
 
-	t.Log("bs = ", len(bs), "; bf =", len(bf), "bf(OggS) =", bytes.LastIndex(bf, []byte("OggS")))
+	t.Log("bs = ", len(bs), "; bf =", len(bf), "bf(S) =", bytes.LastIndex(bf, []byte("S")))
 }
 
-func BenchmarkOggGetDuration(b *testing.B) {
+func BenchmarkGetDuration(b *testing.B) {
-	bs, bf, err := OggReadFile(sampleSong)
+	bs, bf, err := ReadFile(sampleSong)
 	if err != nil {
 		b.Error(err)
 	}
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
-		OggGetDuration(bs, bf)
+		GetDuration(bs, bf)
 	}
 }
 
-func TestOggGetDuration(t *testing.T) {
+func TestGetDuration(t *testing.T) {
-	bs, bf, err := OggReadFile(sampleSong)
+	bs, bf, err := ReadFile(sampleSong)
 	if err != nil {
 		t.Error(err)
 	}
-	t.Log(OggGetDuration(bs, bf))
+	dur := GetDuration(bs, bf)
+	t.Log(dur, ((dur)/time.Second)*time.Second, dur.Milliseconds())
 }