/// <summary>Called by DoSingleOperation to split a full node, then retry the add operation.</summary>
/// <remarks>Same arguments and return value as DoSingleOperation.</remarks>
internal virtual int SplitAndAdd(ref AListSingleOperation <K, T> op, out AListNode <K, T> splitLeft, out AListNode <K, T> splitRight)
{
// Tell DoSingleOperation not to send notifications to the observer
op.AggregateChanged |= 2;
int divAt = _list.Count >> 1;
var mid = _list[divAt];
var left = new BListLeaf <K, T>(_maxNodeSize, _list.CopySection(0, divAt));
var right = new BListLeaf <K, T>(_maxNodeSize, _list.CopySection(divAt, _list.Count - divAt));
int sizeChange;
if (op.CompareToKey(mid, op.Key) >= 0)
{
sizeChange = left.DoSingleOperation(ref op, out splitLeft, out splitRight);
}
else
{
op.BaseIndex += left.TotalCount;
sizeChange = right.DoSingleOperation(ref op, out splitLeft, out splitRight);
}
op.AggregateChanged &= unchecked ((byte)~2);
// (splitLeft may be non-null, meaning that the highest key changed, which doesn't matter here.)
Debug.Assert(splitRight == null);
Debug.Assert(sizeChange == 1);
splitLeft = left;
splitRight = right;
return(sizeChange);
}
