[#218] Support SplitInfo structure

Signed-off-by: Alex Vanin <alexey@nspcc.ru>

pkg/client/object.go

@@ -445,6 +445,8 @@ func (c *Client) getObjectV2(ctx context.Context, p *GetObjectParams, opts ...Ca
 			} else {
 				payload = append(payload, v.GetChunk()...)
 			}
+		case *v2object.SplitInfo: // what else can we do here?
+			return nil, errors.New("object not found, split info has been provided")
 		default:
 			panic(fmt.Sprintf("unexpected Get object part type %T", v))
 		}

pkg/object/splitinfo.go

@@ -0,0 +1,49 @@
+package object
+
+import (
+	"github.com/nspcc-dev/neofs-api-go/v2/object"
+)
+
+type SplitInfo object.SplitInfo
+
+func NewSplitInfoFromV2(v2 *object.SplitInfo) *SplitInfo {
+	return (*SplitInfo)(v2)
+}
+
+func NewSplitInfo() *SplitInfo {
+	return NewSplitInfoFromV2(new(object.SplitInfo))
+}
+
+func (s *SplitInfo) ToV2() *object.SplitInfo {
+	return (*object.SplitInfo)(s)
+}
+
+func (s *SplitInfo) SplitID() *SplitID {
+	return NewSplitIDFromV2(
+		(*object.SplitInfo)(s).GetSplitID(),
+	)
+}
+
+func (s *SplitInfo) SetSplitID(v *SplitID) {
+	(*object.SplitInfo)(s).SetSplitID(v.ToV2())
+}
+
+func (s *SplitInfo) LastPart() *ID {
+	return NewIDFromV2(
+		(*object.SplitInfo)(s).GetLastPart(),
+	)
+}
+
+func (s *SplitInfo) SetLastPart(v *ID) {
+	(*object.SplitInfo)(s).SetLastPart(v.ToV2())
+}
+
+func (s *SplitInfo) Link() *ID {
+	return NewIDFromV2(
+		(*object.SplitInfo)(s).GetLink(),
+	)
+}
+
+func (s *SplitInfo) SetLink(v *ID) {
+	(*object.SplitInfo)(s).SetLink(v.ToV2())
+}

pkg/object/splitinfo_test.go

@@ -0,0 +1,42 @@
+package object_test
+
+import (
+	"crypto/rand"
+	"testing"
+
+	"github.com/nspcc-dev/neofs-api-go/pkg/object"
+	"github.com/stretchr/testify/require"
+)
+
+func TestSplitInfo(t *testing.T) {
+	s := object.NewSplitInfo()
+	splitID := object.NewSplitID()
+	lastPart := generateID()
+	link := generateID()
+
+	s.SetSplitID(splitID)
+	require.Equal(t, splitID, s.SplitID())
+
+	s.SetLastPart(lastPart)
+	require.Equal(t, lastPart, s.LastPart())
+
+	s.SetLink(link)
+	require.Equal(t, link, s.Link())
+
+	t.Run("to and from v2", func(t *testing.T) {
+		v2 := s.ToV2()
+		newS := object.NewSplitInfoFromV2(v2)
+
+		require.Equal(t, s, newS)
+	})
+}
+
+func generateID() *object.ID {
+	var buf [32]byte
+	_, _ = rand.Read(buf[:])
+
+	id := object.NewID()
+	id.SetSHA256(buf)
+
+	return id
+}