Simplify unmarshalling.

packages/ipp/rangeofinteger.go

@@ -3,9 +3,9 @@
 package ipp
 
 import (
+	"bufio"
 	"encoding/binary"
 	"fmt"
-	"io"
 
 	log "github.com/sirupsen/logrus"
 )
@@ -44,14 +44,44 @@ func (r *RangeOfInteger) marshal() []byte {
 	return []byte{}
 }
 
+func (r *RangeOfInteger) unmarshal(byteStream *bufio.Reader) error {
+	var length uint16
+	r.values = make([]IRange, 0, 1)
+	binary.Read(byteStream, binary.BigEndian, &length)
+	name := make([]byte, length)
+	if length > 0 {
+		binary.Read(byteStream, binary.BigEndian, name)
+	}
+	r.name = string(name)
+	binary.Read(byteStream, binary.BigEndian, &length)
+	if length != 8 {
+		return fmt.Errorf("wrong value-length of range-of-integer attribute %v", length)
+	}
+	for length > 0 {
+		var i IRange
+		err := binary.Read(byteStream, binary.BigEndian, &i.lower)
+		if err != nil {
+			return err
+		}
+		err = binary.Read(byteStream, binary.BigEndian, &i.upper)
+		if err != nil {
+			return err
+		}
+		r.values = append(r.values, i)
+		next, err := byteStream.Peek(3)
+		if err != nil {
+			break
+		}
+		if next[0] != byte(rangeOfIntegerValueTag) || next[1] != 0x00 || next[2] != 0x00 {
+			break
+		}
+		// Remove the value tag with the zero length from the stream
+		byteStream.Discard(3)
+		binary.Read(byteStream, binary.BigEndian, &length)
+	}
+	return nil
+}
+
 func (r *RangeOfInteger) addValue(v interface{}) {
 	r.values = append(r.values, v.(IRange))
 }
-
-func unmarshalSingleRangeOfInteger(byteStream io.Reader) (string, IRange) {
-	name, data := unmarshalSingleAttribute(byteStream)
-	var r IRange
-	r.lower = int32(binary.BigEndian.Uint32(data[0:4]))
-	r.upper = int32(binary.BigEndian.Uint32(data[4:8]))
-	return name, r
-}