[#164] sdk/object: Add parent ID getter and setter

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

pkg/object/raw.go

@@ -110,6 +110,11 @@ func (o *RawObject) SetChildren(v ...*ID) {
 	o.setChildren(v...)
 }
 
+// SetParentID sets identifier of the parent object.
+func (o *RawObject) SetParentID(v *ID) {
+	o.setParentID(v)
+}
+
 // SetParent sets parent object w/o payload.
 func (o *RawObject) SetParent(v *Object) {
 	o.setParent(v)

pkg/object/raw_test.go

@@ -251,3 +251,12 @@ func TestRawObject_CutPayload(t *testing.T) {
 	require.Equal(t, p2, o2.GetPayload())
 	require.Equal(t, p1, o1.GetPayload())
 }
+
+func TestRawObject_SetParentID(t *testing.T) {
+	obj := NewRaw()
+
+	id := randID(t)
+	obj.setParentID(id)
+
+	require.Equal(t, id, obj.GetParentID())
+}

pkg/object/rw.go

@@ -251,6 +251,22 @@ func (o *rwObject) setChildren(v ...*ID) {
 	})
 }
 
+// GetParentID returns identifier of the parent object.
+func (o *rwObject) GetParentID() *ID {
+	return NewIDFromV2(
+		(*object.Object)(o).
+			GetHeader().
+			GetSplit().
+			GetParent(),
+	)
+}
+
+func (o *rwObject) setParentID(v *ID) {
+	o.setSplitFields(func(split *object.SplitHeader) {
+		split.SetParent(v.ToV2())
+	})
+}
+
 // GetParent returns parent object w/o payload.
 func (o *rwObject) GetParent() *Object {
 	h := (*object.Object)(o).