[#168] object: Implement binary/JSON encoders/decoders on Attribute

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>

pkg/object/attribute.go

@@ -43,3 +43,35 @@ func (a *Attribute) SetValue(v string) {
 func (a *Attribute) ToV2() *object.Attribute {
 	return (*object.Attribute)(a)
 }
+
+// Marshal marshals Attribute into a protobuf binary form.
+//
+// Buffer is allocated when the argument is empty.
+// Otherwise, the first buffer is used.
+func (d *Attribute) Marshal(b ...[]byte) ([]byte, error) {
+	var buf []byte
+	if len(b) > 0 {
+		buf = b[0]
+	}
+
+	return (*object.Attribute)(d).
+		StableMarshal(buf)
+}
+
+// Unmarshal unmarshals protobuf binary representation of Attribute.
+func (d *Attribute) Unmarshal(data []byte) error {
+	return (*object.Attribute)(d).
+		Unmarshal(data)
+}
+
+// MarshalJSON encodes Attribute to protobuf JSON format.
+func (d *Attribute) MarshalJSON() ([]byte, error) {
+	return (*object.Attribute)(d).
+		MarshalJSON()
+}
+
+// UnmarshalJSON decodes Attribute from protobuf JSON format.
+func (d *Attribute) UnmarshalJSON(data []byte) error {
+	return (*object.Attribute)(d).
+		UnmarshalJSON(data)
+}

pkg/object/attribute_test.go

@@ -21,3 +21,29 @@ func TestAttribute(t *testing.T) {
 	require.Equal(t, key, aV2.GetKey())
 	require.Equal(t, val, aV2.GetValue())
 }
+
+func TestAttributeEncoding(t *testing.T) {
+	a := NewAttribute()
+	a.SetKey("key")
+	a.SetValue("value")
+
+	t.Run("binary", func(t *testing.T) {
+		data, err := a.Marshal()
+		require.NoError(t, err)
+
+		a2 := NewAttribute()
+		require.NoError(t, a2.Unmarshal(data))
+
+		require.Equal(t, a, a2)
+	})
+
+	t.Run("json", func(t *testing.T) {
+		data, err := a.MarshalJSON()
+		require.NoError(t, err)
+
+		a2 := NewAttribute()
+		require.NoError(t, a2.UnmarshalJSON(data))
+
+		require.Equal(t, a, a2)
+	})
+}

v2/object/json.go

@@ -24,3 +24,23 @@ func (h *ShortHeader) UnmarshalJSON(data []byte) error {
 
 	return nil
 }
+
+func (a *Attribute) MarshalJSON() ([]byte, error) {
+	return protojson.MarshalOptions{
+		EmitUnpopulated: true,
+	}.Marshal(
+		AttributeToGRPCMessage(a),
+	)
+}
+
+func (a *Attribute) UnmarshalJSON(data []byte) error {
+	msg := new(object.Header_Attribute)
+
+	if err := protojson.Unmarshal(data, msg); err != nil {
+		return err
+	}
+
+	*a = *AttributeFromGRPCMessage(msg)
+
+	return nil
+}

v2/object/json_test.go

@@ -18,3 +18,15 @@ func TestShortHeaderJSON(t *testing.T) {
 
 	require.Equal(t, h, h2)
 }
+
+func TestAttributeJSON(t *testing.T) {
+	a := generateAttribute("key", "value")
+
+	data, err := a.MarshalJSON()
+	require.NoError(t, err)
+
+	a2 := new(object.Attribute)
+	require.NoError(t, a2.UnmarshalJSON(data))
+
+	require.Equal(t, a, a2)
+}

v2/object/marshal.go

@@ -213,6 +213,17 @@ func (a *Attribute) StableSize() (size int) {
 	return size
 }
 
+func (a *Attribute) Unmarshal(data []byte) error {
+	m := new(object.Header_Attribute)
+	if err := goproto.Unmarshal(data, m); err != nil {
+		return err
+	}
+
+	*a = *AttributeFromGRPCMessage(m)
+
+	return nil
+}
+
 func (h *SplitHeader) StableMarshal(buf []byte) ([]byte, error) {
 	if h == nil {
 		return []byte{}, nil

v2/object/marshal_test.go

@@ -29,16 +29,14 @@ func TestShortHeader_StableMarshal(t *testing.T) {
 
 func TestAttribute_StableMarshal(t *testing.T) {
 	from := generateAttribute("Key", "Value")
-	transport := new(grpc.Header_Attribute)
 
 	t.Run("non empty", func(t *testing.T) {
 		wire, err := from.StableMarshal(nil)
 		require.NoError(t, err)
 
-		err = goproto.Unmarshal(wire, transport)
+		to := new(object.Attribute)
-		require.NoError(t, err)
+		require.NoError(t, to.Unmarshal(wire))
 
-		to := object.AttributeFromGRPCMessage(transport)
 		require.Equal(t, from, to)
 	})
 }