/// <returns>
/// the split node if this node is split
/// or this if the first key has changed
/// </returns>
public Db4objects.Db4o.Internal.Btree.BTreeNode Add(Transaction trans, IPreparedComparison
preparedComparison, object obj)
{
ByteArrayBuffer reader = PrepareRead(trans);
Searcher s = Search(trans, preparedComparison, reader);
if (_isLeaf)
{
PrepareWrite(trans);
SetStateDirty();
if (WasRemoved(trans, s))
{
CancelRemoval(trans, obj, s.Cursor());
return(null);
}
if (s.Count() > 0 && !s.BeforeFirst())
{
s.MoveForward();
}
PrepareInsert(s.Cursor());
_keys[s.Cursor()] = ApplyNewAddPatch(trans, obj);
}
else
{
Db4objects.Db4o.Internal.Btree.BTreeNode childNode = Child(reader, s.Cursor());
Db4objects.Db4o.Internal.Btree.BTreeNode childNodeOrSplit = childNode.Add(trans,
preparedComparison, obj);
if (childNodeOrSplit == null)
{
return(null);
}
PrepareWrite(trans);
SetStateDirty();
_keys[s.Cursor()] = childNode._keys[0];
if (childNode != childNodeOrSplit)
{
int splitCursor = s.Cursor() + 1;
PrepareInsert(splitCursor);
_keys[splitCursor] = childNodeOrSplit._keys[0];
_children[splitCursor] = childNodeOrSplit;
}
}
if (MustSplit())
{
return(Split(trans));
}
if (s.Cursor() == 0)
{
return(this);
}
return(null);
}
