Added Base8 Implementation

base8.go

@@ -0,0 +1,51 @@
+package multibase
+
+import (
+	"fmt"
+	"strconv"
+)
+
+func octalEncodeToString(src []byte) string {
+	dst := make([]byte, len(src)*3)
+	octalEncode(dst, src)
+	return string(dst)
+}
+
+var octalTable = [8]byte{
+	'0', '1', '2', '3', '4', '5', '6', '7',
+}
+
+func octalEncode(dst, src []byte) int {
+	for i, v := range src {
+		dst[i*3+2] = octalTable[v&0x7]
+		v = v >> 3
+		dst[i*3+1] = octalTable[v&0x7]
+		v = v >> 3
+		dst[i*3] = octalTable[v&0x7]
+		v = v >> 3
+	}
+
+	return len(src) * 3
+}
+
+// decodeOctalString takes an octal string and gives byte array of decimals
+func decodeOctalString(s string) ([]byte, error) {
+	if len(s)%3 != 0 {
+		return nil, fmt.Errorf("cannot decode multibase: %s",
+			"length should be a multiple of 3")
+	}
+
+	data := make([]byte, len(s)/3)
+
+	for i, dstIndex := 0, 0; i < len(s); i = i + 3 {
+		value, err := strconv.ParseInt(s[i:i+3], 8, 16)
+		if err != nil {
+			return nil, fmt.Errorf("error while conversion: %s", err)
+		}
+
+		data[dstIndex] = byte(value)
+		dstIndex++
+	}
+
+	return data, nil
+}

encoder.go

@@ -48,6 +48,7 @@ func EncoderByName(str string) (Encoder, error) {
 	return Encoder{base}, nil
 }
 
+// Encoding returns the Encoder's encoding
 func (p Encoder) Encoding() Encoding {
 	return p.enc
 }

multibase.go

@@ -42,6 +42,7 @@ const (
 // specified in standard are left out
 var Encodings = map[string]Encoding{
 	"identity":          0x00,
+	"base8":             '7',
 	"base16":            'f',
 	"base16upper":       'F',
 	"base32":            'b',
@@ -60,8 +61,10 @@ var Encodings = map[string]Encoding{
 	"base64urlpad":      'U',
 }
 
+// EncodingToStr is the reverse map to get string representation given encoding
 var EncodingToStr = map[Encoding]string{
 	0x00: "identity",
+	'7':  "base8",
 	'f':  "base16",
 	'F':  "base16upper",
 	'b':  "base32",
@@ -92,6 +95,8 @@ func Encode(base Encoding, data []byte) (string, error) {
 	case Identity:
 		// 0x00 inside a string is OK in golang and causes no problems with the length calculation.
 		return string(Identity) + string(data), nil
+	case Base8:
+		return string(Base8) + octalEncodeToString(data), nil
 	case Base16:
 		return string(Base16) + hex.EncodeToString(data), nil
 	case Base16Upper:
@@ -141,6 +146,9 @@ func Decode(data string) (Encoding, []byte, error) {
 	switch enc {
 	case Identity:
 		return Identity, []byte(data[1:]), nil
+	case Base8:
+		bytes, err := decodeOctalString(data[1:])
+		return enc, bytes, err
 	case Base16, Base16Upper:
 		bytes, err := hex.DecodeString(data[1:])
 		return enc, bytes, err

multibase_test.go

@@ -24,6 +24,7 @@ func TestMap(t *testing.T) {
 var sampleBytes = []byte("Decentralize everything!!!")
 var encodedSamples = map[Encoding]string{
 	Identity:          string(0x00) + "Decentralize everything!!!",
+	Base8:             "7104145143145156164162141154151172145040145166145162171164150151156147041041041",
 	Base16:            "f446563656e7472616c697a652065766572797468696e67212121",
 	Base16Upper:       "F446563656E7472616C697A652065766572797468696E67212121",
 	Base32:            "birswgzloorzgc3djpjssazlwmvzhs5dinfxgoijbee",
@@ -82,7 +83,7 @@ func TestRoundTrip(t *testing.T) {
 	buf := make([]byte, 17)
 	rand.Read(buf)
 
-	baseList := []Encoding{Identity, Base16, Base32, Base32hex, Base32pad, Base32hexPad, Base58BTC, Base58Flickr, Base64pad, Base64urlPad}
+	baseList := []Encoding{Identity, Base8, Base16, Base32, Base32hex, Base32pad, Base32hexPad, Base58BTC, Base58Flickr, Base64pad, Base64urlPad}
 
 	for _, base := range baseList {
 		enc, err := Encode(base, buf)
@@ -96,17 +97,17 @@ func TestRoundTrip(t *testing.T) {
 		}
 
 		if e != base {
-			t.Fatal("got wrong encoding out")
+			t.Fatal("got wrong encoding output")
 		}
 
 		if !bytes.Equal(buf, out) {
-			t.Fatal("input wasnt the same as output", buf, out)
+			t.Fatal("input wasn't the same as output", buf, out)
 		}
 	}
 
 	_, _, err := Decode("")
 	if err == nil {
-		t.Fatal("shouldnt be able to decode empty string")
+		t.Fatal("shouldn't be able to decode empty string")
 	}
 }
 
@@ -117,6 +118,7 @@ func BenchmarkRoundTrip(b *testing.B) {
 
 	bases := map[string]Encoding{
 		"Identity":          Identity,
+		"Base8":             Base8,
 		"Base16":            Base16,
 		"Base16Upper":       Base16Upper,
 		"Base32":            Base32,
@@ -149,11 +151,11 @@ func BenchmarkRoundTrip(b *testing.B) {
 				}
 
 				if e != base {
-					b.Fatal("got wrong encoding out")
+					b.Fatal("got wrong encoding output")
 				}
 
 				if !bytes.Equal(buf, out) {
-					b.Fatal("input wasnt the same as output", buf, out)
+					b.Fatal("input wasn't the same as output", buf, out)
 				}
 			}
 		})