[#211] blobstor: Refactor GetBig parameters and result

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

pkg/local_object_storage/blobstor/util.go

@@ -0,0 +1,33 @@
+package blobstor
+
+import (
+	objectSDK "github.com/nspcc-dev/neofs-api-go/pkg/object"
+	"github.com/nspcc-dev/neofs-node/pkg/core/object"
+)
+
+type address struct {
+	addr *objectSDK.Address
+}
+
+// SetAddress sets the address of the requested object.
+func (a *address) SetAddress(addr *objectSDK.Address) {
+	a.addr = addr
+}
+
+type roObject struct {
+	obj *object.Object
+}
+
+// Object returns the object.
+func (o roObject) Object() *object.Object {
+	return o.obj
+}
+
+type rwObject struct {
+	roObject
+}
+
+// SetObject sets the object.
+func (o *rwObject) SetObject(obj *object.Object) {
+	o.obj = obj
+}