// removes the leftmost leaf from the tree
public override IMemTreeNode SnipLeftLeaf()
{
IMemTreeNode newLeftChild = leftChild.SnipLeftLeaf();
if (newLeftChild == null)
{ // leftChild is a leaf node
return(rightChild);
}
else
{
leftChild = newLeftChild;
contiguousBlocks = (leftChild.ContiguousBlocks < rightChild.ContiguousBlocks) ? rightChild.ContiguousBlocks : leftChild.ContiguousBlocks;
return(this);
}
}
private IMemTreeNode Merge()
{
if (rightChild is ContentNode)
{
if (leftChild is ContentNode)
{
// if they're both contentnodes, we can just substitute them with a single new contentnode
return(new ContentNode()
{
FirstBlock = leftChild.FirstBlock, LastBlock = rightChild.LastBlock
});
}
else
{ // right is a contentnode, but left isn't
// merge the right contentnode into the lefttree
leftChild.ExpandRightLeaf(rightChild.LastBlock - leftChild.RightLeaf.LastBlock);
return(leftChild);
}
}
else if (leftChild is ContentNode)
{ // left is a contentnode, but right isn't
// merge the left contentnode into the righttree
rightChild.ExpandLeftLeaf(rightChild.LeftLeaf.FirstBlock - leftChild.FirstBlock);
return(rightChild);
}
else
{ // both left and right are index nodes. f**k it.
// snip the leftmost leaf off the right tree
IMemTreeNode snipped = rightChild.LeftLeaf;
rightChild = rightChild.SnipLeftLeaf();
// append that to the rightmost leaf of the left tree
leftChild.RightLeaf.LastBlock = snipped.LastBlock;
contiguousBlocks = (leftChild.ContiguousBlocks < rightChild.ContiguousBlocks) ? rightChild.ContiguousBlocks : leftChild.ContiguousBlocks;
return(this);
}
}
