[#1143] blobstor: Implement existsSmall check

Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>

pkg/local_object_storage/blobstor/exists_test.go

@@ -0,0 +1,78 @@
+package blobstor
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	objectCore "github.com/nspcc-dev/neofs-node/pkg/core/object"
+	objectSDK "github.com/nspcc-dev/neofs-sdk-go/object"
+	"github.com/stretchr/testify/require"
+)
+
+func TestExists(t *testing.T) {
+	dir, err := os.MkdirTemp("", "neofs*")
+	require.NoError(t, err)
+	t.Cleanup(func() { _ = os.RemoveAll(dir) })
+
+	const smallSizeLimit = 512
+
+	b := New(WithRootPath(dir),
+		WithSmallSizeLimit(smallSizeLimit),
+		WithBlobovniczaShallowWidth(1)) // default width is 16, slow init
+	require.NoError(t, b.Open())
+	require.NoError(t, b.Init())
+
+	objects := []*objectSDK.Object{
+		testObject(smallSizeLimit / 2),
+		testObject(smallSizeLimit + 1),
+	}
+
+	for i := range objects {
+		prm := new(PutPrm)
+		prm.SetObject(objects[i])
+		_, err = b.Put(prm)
+		require.NoError(t, err)
+	}
+
+	prm := new(ExistsPrm)
+	for i := range objects {
+		prm.SetAddress(objectCore.AddressOf(objects[i]))
+
+		res, err := b.Exists(prm)
+		require.NoError(t, err)
+		require.True(t, res.Exists())
+	}
+
+	prm.SetAddress(testAddress())
+	res, err := b.Exists(prm)
+	require.NoError(t, err)
+	require.False(t, res.Exists())
+
+	t.Run("corrupt direcrory", func(t *testing.T) {
+		var bigDir string
+		de, err := os.ReadDir(dir)
+		require.NoError(t, err)
+		for i := range de {
+			if de[i].Name() != blobovniczaDir {
+				bigDir = filepath.Join(dir, de[i].Name())
+				break
+			}
+		}
+		require.NotEmpty(t, bigDir)
+
+		require.NoError(t, os.Chmod(dir, 0))
+		t.Cleanup(func() { require.NoError(t, os.Chmod(dir, b.fsTree.Permissions)) })
+
+		// Object exists, first error is logged.
+		prm.SetAddress(objectCore.AddressOf(objects[0]))
+		res, err := b.Exists(prm)
+		require.NoError(t, err)
+		require.True(t, res.Exists())
+
+		// Object doesn't exist, first error is returned.
+		prm.SetAddress(objectCore.AddressOf(objects[1]))
+		_, err = b.Exists(prm)
+		require.Error(t, err)
+	})
+}