private void initTree(Tree tree) {
        _currentVolume = tree.getVolume();
        _currentTree = tree;
        _holes.clear();
        _treeDepth = tree.getDepth();
        for (int index = Exchange.MAX_TREE_DEPTH; --index >= 0;) {
            _edgeBuffers[index] = null;
            _edgePages[index] = 0;
            _edgeKeys[index] = null;
            _edgePositions[index] = 0;
        }
    }