[#211] blobstor: Implement no-op GetSmall operation

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

pkg/local_object_storage/blobstor/get_small.go

@@ -0,0 +1,27 @@
+package blobstor
+
+import (
+	"github.com/pkg/errors"
+)
+
+// GetSmallPrm groups the parameters of GetSmallPrm operation.
+type GetSmallPrm struct {
+	address
+	rwBlobovniczaID
+}
+
+// GetBigRes groups resulting values of GetBig operation.
+type GetSmallRes struct {
+	roObject
+}
+
+// GetSmall reads the object from blobovnicza of BLOB storage by address.
+//
+// If blobovnicza ID is not set or set to nil, BlobStor tries to get object
+// from any blobovnicza.
+//
+// Returns any error encountered that
+// did not allow to completely read the object.
+func (b *BlobStor) GetSmall(prm *GetSmallPrm) (*GetSmallRes, error) {
+	return nil, errors.New("method GetSmall is not implemented yet")
+}

pkg/local_object_storage/blobstor/util.go

@@ -3,6 +3,7 @@ package blobstor
 import (
 	objectSDK "github.com/nspcc-dev/neofs-api-go/pkg/object"
 	"github.com/nspcc-dev/neofs-node/pkg/core/object"
+	"github.com/nspcc-dev/neofs-node/pkg/local_object_storage/blobovnicza"
 )
 
 type address struct {
@@ -31,3 +32,21 @@ type rwObject struct {
 func (o *rwObject) SetObject(obj *object.Object) {
 	o.obj = obj
 }
+
+type roBlobovniczaID struct {
+	blobovniczaID *blobovnicza.ID
+}
+
+// BlobovniczaID returns blobovnicza ID.
+func (v roBlobovniczaID) BlobovniczaID() *blobovnicza.ID {
+	return v.blobovniczaID
+}
+
+type rwBlobovniczaID struct {
+	roBlobovniczaID
+}
+
+// SetBlobovniczaID sets blobovnicza ID.
+func (v *rwBlobovniczaID) SetBlobovniczaID(id *blobovnicza.ID) {
+	v.blobovniczaID = id
+}