[#13] services/object: Implement Head handlers

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

pkg/services/object/executor.go

@@ -129,8 +129,17 @@ func (s *executorSvc) Put(ctx context.Context) (object.PutObjectStreamer, error)
 	}, nil
 }
 
-func (*executorSvc) Head(context.Context, *object.HeadRequest) (*object.HeadResponse, error) {
-	panic("implement me")
+func (s *executorSvc) Head(ctx context.Context, req *object.HeadRequest) (*object.HeadResponse, error) {
+	respBody, err := s.exec.Head(ctx, req.GetBody())
+	if err != nil {
+		return nil, errors.Wrap(err, "could not execute Head request")
+	}
+
+	resp := new(object.HeadResponse)
+	resp.SetBody(respBody)
+	resp.SetMetaHeader(s.metaHeader)
+
+	return resp, nil
 }
 
 func (s *searchStreamer) Recv() (*object.SearchResponse, error) {

pkg/services/object/sign.go

@@ -17,6 +17,7 @@ type signService struct {
 	getSigService    *util.UnarySignService
 	putService       object.Service
 	rangeSigService  *util.UnarySignService
+	headSigService   *util.UnarySignService
 }
 
 type searchStreamSigner struct {
@@ -65,6 +66,12 @@ func NewSignService(key *ecdsa.PrivateKey, svc object.Service) object.Service {
 				return svc.GetRange(ctx, req.(*object.GetRangeRequest))
 			},
 		),
+		headSigService: util.NewUnarySignService(
+			key,
+			func(ctx context.Context, req interface{}) (interface{}, error) {
+				return svc.Head(ctx, req.(*object.HeadRequest))
+			},
+		),
 	}
 }
 
@@ -126,8 +133,13 @@ func (s *signService) Put(ctx context.Context) (object.PutObjectStreamer, error)
 	}, nil
 }
 
-func (s *signService) Head(context.Context, *object.HeadRequest) (*object.HeadResponse, error) {
-	panic("implement me")
+func (s *signService) Head(ctx context.Context, req *object.HeadRequest) (*object.HeadResponse, error) {
+	resp, err := s.headSigService.HandleUnaryRequest(ctx, req)
+	if err != nil {
+		return nil, err
+	}
+
+	return resp.(*object.HeadResponse), nil
 }
 
 func (s *searchStreamSigner) Recv() (*object.SearchResponse, error) {