optimize encodeUUID

database_sql.go

@@ -30,7 +30,8 @@ func DatabaseSQLValue(ci *ConnInfo, src Value) (interface{}, error) {
 }
 
 func EncodeValueText(src TextEncoder) (interface{}, error) {
-	buf, err := src.EncodeText(nil, make([]byte, 0, 32))
+	var encBuf [36]byte
+	buf, err := src.EncodeText(nil, encBuf[:])
 	if err != nil {
 		return nil, err
 	}

uuid.go

@@ -84,7 +84,7 @@ func (src *UUID) AssignTo(dst interface{}) error {
 			copy(*v, src.Bytes[:])
 			return nil
 		case *string:
-			*v = encodeUUID(src.Bytes)
+			*v = string(encodeUUID(src.Bytes))
 			return nil
 		default:
 			if nextDst, retry := GetAssignToDstType(v); retry {
@@ -120,8 +120,21 @@ func parseUUID(src string) (dst [16]byte, err error) {
 }
 
 // encodeUUID converts a uuid byte array to UUID standard string form.
-func encodeUUID(src [16]byte) string {
-	return fmt.Sprintf("%x-%x-%x-%x-%x", src[0:4], src[4:6], src[6:8], src[8:10], src[10:16])
+func encodeUUID(src [16]byte) (dst []byte) {
+	var buf [36]byte
+	dst = buf[:]
+
+	hex.Encode(dst, src[:4])
+	buf[8] = '-'
+	hex.Encode(dst[9:13], src[4:6])
+	buf[13] = '-'
+	hex.Encode(dst[14:18], src[6:8])
+	buf[18] = '-'
+	hex.Encode(dst[19:23], src[8:10])
+	buf[23] = '-'
+	hex.Encode(dst[24:], src[10:])
+
+	return
 }
 
 func (dst *UUID) DecodeText(ci *ConnInfo, src []byte) error {
@@ -209,7 +222,7 @@ func (src UUID) MarshalJSON() ([]byte, error) {
 	case Present:
 		var buff bytes.Buffer
 		buff.WriteByte('"')
-		buff.WriteString(encodeUUID(src.Bytes))
+		buff.Write(encodeUUID(src.Bytes))
 		buff.WriteByte('"')
 		return buff.Bytes(), nil
 	case Null: