/// NextLeaf - This is a pointer to the next leaf in the tree, allowing
/// efficient in-order forward iteration of the tree without traversal.
- const RopePieceBTreeLeaf *NextLeaf;
+ RopePieceBTreeLeaf **PrevLeaf, *NextLeaf;
public:
- RopePieceBTreeLeaf() : RopePieceBTreeNode(true), NumPieces(0), NextLeaf(0){}
+ RopePieceBTreeLeaf() : RopePieceBTreeNode(true), NumPieces(0),
+ PrevLeaf(0), NextLeaf(0) {}
+ ~RopePieceBTreeLeaf() {
+ if (PrevLeaf || NextLeaf)
+ removeFromLeafInOrder();
+ }
bool isFull() const { return NumPieces == 2*WidthFactor; }
}
const RopePieceBTreeLeaf *getNextLeafInOrder() const { return NextLeaf; }
- void setNextLeafInOrder(const RopePieceBTreeLeaf *NL) { NextLeaf = NL; }
+ void insertAfterLeafInOrder(RopePieceBTreeLeaf *Node) {
+ assert(PrevLeaf == 0 && NextLeaf == 0 && "Already in ordering");
+
+ NextLeaf = Node->NextLeaf;
+ if (NextLeaf)
+ NextLeaf->PrevLeaf = &NextLeaf;
+ PrevLeaf = &Node->NextLeaf;
+ Node->NextLeaf = this;
+ }
+
+ void removeFromLeafInOrder() {
+ if (PrevLeaf) {
+ *PrevLeaf = NextLeaf;
+ if (NextLeaf)
+ NextLeaf->PrevLeaf = PrevLeaf;
+ } else if (NextLeaf) {
+ NextLeaf->PrevLeaf = 0;
+ }
+ }
/// FullRecomputeSizeLocally - This method recomputes the 'Size' field by
/// summing the size of all RopePieces.
FullRecomputeSizeLocally();
// Update the list of leaves.
- NewNode->setNextLeafInOrder(this->getNextLeafInOrder());
- this->setNextLeafInOrder(NewNode);
+ NewNode->insertAfterLeafInOrder(this);
// These insertions can't fail.
if (this->size() >= Offset)