[#220] shard: Implement Open/Init/Close methods

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

pkg/local_object_storage/shard/control.go

@@ -0,0 +1,53 @@
+package shard
+
+import (
+	"github.com/pkg/errors"
+)
+
+// Open opens all Shard's components.
+func (s *Shard) Open() error {
+	for _, component := range []interface {
+		Open() error
+	}{
+		s.blobStor,
+		s.metaBase,
+	} {
+		if err := component.Open(); err != nil {
+			return errors.Wrapf(err, "could not open %s", component)
+		}
+	}
+
+	return nil
+}
+
+// Init initializes all Shard's components.
+func (s *Shard) Init() error {
+	for _, component := range []interface {
+		Init() error
+	}{
+		s.blobStor,
+		s.metaBase,
+	} {
+		if err := component.Init(); err != nil {
+			return errors.Wrapf(err, "could not initialize %s", component)
+		}
+	}
+
+	return nil
+}
+
+// Close releases all Shard's components.
+func (s *Shard) Close() error {
+	for _, component := range []interface {
+		Close() error
+	}{
+		s.blobStor,
+		s.metaBase,
+	} {
+		if err := component.Close(); err != nil {
+			return errors.Wrapf(err, "could not close %s", component)
+		}
+	}
+
+	return nil
+}