[#947] engine: Evacuate trees to local shards

Signed-off-by: Dmitrii Stepanov <d.stepanov@yadro.com>

pkg/local_object_storage/pilorama/forest.go

@@ -311,3 +311,27 @@ func (f *memoryForest) TreeListTrees(_ context.Context, prm TreeListTreesPrm) (*
 	}
 	return &result, nil
 }
+
+// TreeApplyStream implements ForestStorage.
+func (f *memoryForest) TreeApplyStream(ctx context.Context, cnr cid.ID, treeID string, source <-chan *Move) error {
+	fullID := cnr.String() + "/" + treeID
+	s, ok := f.treeMap[fullID]
+	if !ok {
+		s = newMemoryTree()
+		f.treeMap[fullID] = s
+	}
+
+	for {
+		select {
+		case <-ctx.Done():
+			return ctx.Err()
+		case m, ok := <-source:
+			if !ok {
+				return nil
+			}
+			if e := s.Apply(m); e != nil {
+				return e
+			}
+		}
+	}
+}