blobovnicza: Fix write error at zero depth

Previously, blobovnicza tree with depth=0 (i.e. group of DBs without
subdirectories) failed to write any object. There was a mistake in code
which worked incorrectly for depth=0 particular case.

Fix `iterateDeepest` method iterating over paths to DBs as if they were
directories. From now it passes current directory only.

Signed-off-by: Leonard Lyubich <[email protected]>

pkg/local_object_storage/blobstor/blobovniczatree/iterate.go

@@ -75,11 +75,13 @@ func (b *Blobovniczas) iterateSortedLeaves(addr *oid.Address, f func(string) (bo
 
 // iterator over directories with Blobovniczas sorted by weight.
 func (b *Blobovniczas) iterateDeepest(addr oid.Address, f func(string) (bool, error)) error {
-	depth := b.blzShallowDepth
-	if depth > 0 {
-		depth--
+	if b.blzShallowDepth == 0 {
+		_, err := f(".")
+		return err
 	}
 
+	depth := b.blzShallowDepth - 1
+
 	_, err := b.iterateSorted(
 		&addr,
 		make([]string, 0, depth),

pkg/local_object_storage/blobstor/blobovniczatree/put_test.go

@@ -0,0 +1,39 @@
+package blobovniczatree_test
+
+import (
+	"testing"
+
+	. "github.com/nspcc-dev/neofs-node/pkg/local_object_storage/blobstor/blobovniczatree"
+	"github.com/nspcc-dev/neofs-node/pkg/local_object_storage/blobstor/common"
+	oidtest "github.com/nspcc-dev/neofs-sdk-go/object/id/test"
+	objecttest "github.com/nspcc-dev/neofs-sdk-go/object/test"
+	"github.com/stretchr/testify/require"
+)
+
+func TestSingleDir(t *testing.T) {
+	tree := NewBlobovniczaTree(
+		WithRootPath(t.TempDir()),
+		WithBlobovniczaShallowDepth(0),
+		WithBlobovniczaShallowWidth(10),
+	)
+
+	require.NoError(t, tree.Open(false))
+	defer func() { _ = tree.Close() }()
+	require.NoError(t, tree.Init())
+
+	bObj, err := objecttest.Object(t).Marshal()
+	require.NoError(t, err)
+
+	putPrm := common.PutPrm{
+		Address: oidtest.Address(),
+		RawData: bObj,
+	}
+
+	_, err = tree.Put(putPrm)
+	require.NoError(t, err)
+
+	_, err = tree.Get(common.GetPrm{
+		Address: putPrm.Address,
+	})
+	require.NoError(t, err)
+}