[#199] Get virtual objects from metabase

Virtual objects are obtained differently with
relative lookup in parent bucket.

Signed-off-by: Alex Vanin <alexey@nspcc.ru>

pkg/local_object_storage/metabase/v2/get.go

@@ -1,6 +1,9 @@
 package meta
 
 import (
+	"fmt"
+
+	"github.com/nspcc-dev/neofs-api-go/pkg/container"
 	objectSDK "github.com/nspcc-dev/neofs-api-go/pkg/object"
 	"github.com/nspcc-dev/neofs-node/pkg/core/object"
 	"go.etcd.io/bbolt"
@@ -17,8 +20,8 @@ func (db *DB) Get(addr *objectSDK.Address) (obj *object.Object, err error) {
 	return obj, err
 }
 
-func (db *DB) get(tx *bbolt.Tx, addr *objectSDK.Address) (obj *object.Object, err error) {
+func (db *DB) get(tx *bbolt.Tx, addr *objectSDK.Address) (*object.Object, error) {
-	obj = object.New()
+	obj := object.New()
 	key := objectKey(addr.ObjectID())
 	cid := addr.ContainerID()
 
@@ -44,7 +47,8 @@ func (db *DB) get(tx *bbolt.Tx, addr *objectSDK.Address) (obj *object.Object, er
 		return obj, obj.Unmarshal(data)
 	}
 
-	return nil, ErrNotFound
+	// if not found then check if object is a virtual
+	return getVirtualObject(tx, cid, key)
 }
 
 func getFromBucket(tx *bbolt.Tx, name, key []byte) []byte {
@@ -55,3 +59,38 @@ func getFromBucket(tx *bbolt.Tx, name, key []byte) []byte {
 
 	return bkt.Get(key)
 }
+
+func getVirtualObject(tx *bbolt.Tx, cid *container.ID, key []byte) (*object.Object, error) {
+	parentBucket := tx.Bucket(parentBucketName(cid))
+	if parentBucket == nil {
+		return nil, ErrNotFound
+	}
+
+	relativeLst, err := decodeList(parentBucket.Get(key))
+	if err != nil {
+		return nil, err
+	}
+
+	if len(relativeLst) == 0 { // this should never happen though
+		return nil, ErrNotFound
+	}
+
+	// pick last item, for now there is not difference which address to pick
+	// but later list might be sorted so first or last value can be more
+	// prioritized to choose
+	virtualOID := relativeLst[len(relativeLst)-1]
+	data := getFromBucket(tx, primaryBucketName(cid), virtualOID)
+
+	child := object.New()
+
+	err = child.Unmarshal(data)
+	if err != nil {
+		return nil, fmt.Errorf("can't unmarshal child with parent: %w", err)
+	}
+
+	if child.GetParent() == nil { // this should never happen though
+		return nil, ErrNotFound
+	}
+
+	return child.GetParent(), nil
+}

pkg/local_object_storage/metabase/v2/get_test.go

@@ -1,6 +1,7 @@
 package meta_test
 
 import (
+	"bytes"
 	"testing"
 
 	objectSDK "github.com/nspcc-dev/neofs-api-go/pkg/object"
@@ -13,51 +14,83 @@ func TestDB_Get(t *testing.T) {
 	defer releaseDB(db)
 
 	raw := generateRawObject(t)
+
+	// equal fails on diff of <nil> attributes and <{}> attributes,
+	/* so we make non empty attribute slice in parent*/
 	addAttribute(raw, "foo", "bar")
 
 	t.Run("object not found", func(t *testing.T) {
-		obj := object.NewFromV2(raw.ToV2())
+		_, err := db.Get(raw.Object().Address())
-
-		_, err := db.Get(obj.Address())
 		require.Error(t, err)
 	})
 
 	t.Run("put regular object", func(t *testing.T) {
-		obj := object.NewFromV2(raw.ToV2())
+		err := db.Put(raw.Object(), nil)
-
-		err := db.Put(obj, nil)
 		require.NoError(t, err)
 
-		newObj, err := db.Get(obj.Address())
+		newObj, err := db.Get(raw.Object().Address())
 		require.NoError(t, err)
-		require.Equal(t, obj, newObj)
+		require.Equal(t, raw.Object(), newObj)
 	})
 
 	t.Run("put tombstone object", func(t *testing.T) {
 		raw.SetType(objectSDK.TypeTombstone)
 		raw.SetID(testOID())
 
-		obj := object.NewFromV2(raw.ToV2())
+		err := db.Put(raw.Object(), nil)
-
-		err := db.Put(obj, nil)
 		require.NoError(t, err)
 
-		newObj, err := db.Get(obj.Address())
+		newObj, err := db.Get(raw.Object().Address())
 		require.NoError(t, err)
-		require.Equal(t, obj, newObj)
+		require.Equal(t, raw.Object(), newObj)
 	})
 
 	t.Run("put storage group object", func(t *testing.T) {
 		raw.SetType(objectSDK.TypeStorageGroup)
 		raw.SetID(testOID())
 
-		obj := object.NewFromV2(raw.ToV2())
+		err := db.Put(raw.Object(), nil)
-
-		err := db.Put(obj, nil)
 		require.NoError(t, err)
 
-		newObj, err := db.Get(obj.Address())
+		newObj, err := db.Get(raw.Object().Address())
 		require.NoError(t, err)
-		require.Equal(t, obj, newObj)
+		require.Equal(t, raw.Object(), newObj)
+	})
+
+	t.Run("put virtual object", func(t *testing.T) {
+		cid := testCID()
+		parent := generateRawObjectWithCID(t, cid)
+		addAttribute(parent, "foo", "bar")
+
+		child := generateRawObjectWithCID(t, cid)
+		child.SetParent(parent.Object().SDK())
+		child.SetParentID(parent.Object().Address().ObjectID())
+
+		err := db.Put(child.Object(), nil)
+		require.NoError(t, err)
+
+		newParent, err := db.Get(parent.Object().Address())
+		require.NoError(t, err)
+		require.True(t, binaryEqual(parent.Object(), newParent))
+
+		newChild, err := db.Get(child.Object().Address())
+		require.NoError(t, err)
+		require.True(t, binaryEqual(child.Object(), newChild))
 	})
 }
+
+// binary equal is used when object contains empty lists in the structure and
+// requre.Equal fails on comparing <nil> and []{} lists.
+func binaryEqual(a, b *object.Object) bool {
+	binaryA, err := a.Marshal()
+	if err != nil {
+		return false
+	}
+
+	binaryB, err := b.Marshal()
+	if err != nil {
+		return false
+	}
+
+	return bytes.Equal(binaryA, binaryB)
+}