void MXTree::Split(GiSTnode **node, const GiSTentry& entry)
{
double radii[2], dist, *dists = new double[(*node)->NumEntries()*2];
int pageNums[2], cands[2];
vector<vector<int>> vec(2);
((MXTnode *)(*node))->TestPromotion(radii, &dist, pageNums, cands, dists, vec);
if (Trade((*node)->Path().IsRoot(), radii, dist, pageNums, ((MXTnode *)(*node))->GetPageNum()+1, (*node)->NumEntries())) {
// don't split now
delete[] dists;
GiSTpath oldPath = (*node)->Path();
int startPage = ((*node)->Path().IsRoot() ? rootPage : (*node)->Path().Page());
int pageNum = ((MXTnode *)(*node))->GetPageNum();
((MXTfile *)store)->Deallocate(startPage, pageNum);
startPage = ((MXTfile *)store)->Allocate(++pageNum);
(*node)->Path().MakeSibling(startPage);
rootPage = ((*node)->Path().IsRoot() ? startPage : rootPage);
((MXTnode *)(*node))->SetPageNum(pageNum);
WriteNode(*node);
if (!(*node)->Path().IsRoot() && startPage != oldPath.Page()) {
GiSTpath parentPath = oldPath;
parentPath.MakeParent();
GiSTnode *parentNode = ReadNode(parentPath);
GiSTentry *e = parentNode->SearchPtr(oldPath.Page());
assert(e != NULL);
int pos = e->Position();
e->SetPtr(startPage);
parentNode->DeleteEntry(pos);
parentNode->InsertBefore(*e, pos);
WriteNode(parentNode);
delete parentNode;
delete e;
}
} else {
// split now
bool bLeft = false, bNewRoot = false;
if ((*node)->Path().IsRoot()) {
bNewRoot = true;
(*node)->Path().MakeChild(rootPage);
rootPage = store->Allocate();
}
int oldPageNum = ((MXTnode *)(*node))->GetPageNum();
GiSTnode *node2 = ((MXTnode *)(*node))->PickSplit(cands, dists, vec);
delete[] dists;
int curPageNum = ((MXTnode *)(*node))->GetPageNum();
assert(oldPageNum >= curPageNum);
if (oldPageNum > curPageNum) {
((MXTfile *)store)->Deallocate((*node)->Path().Page()+curPageNum, oldPageNum-curPageNum);
}
node2->Path().MakeSibling(((MXTfile *)store)->Allocate(((MXTnode *)node2)->GetPageNum()));
WriteNode(*node);
WriteNode(node2);
GiSTentry *e = (*node)->SearchPtr(entry.Ptr());
if (e != NULL) {
bLeft = true;
delete e;
}
GiSTentry *e1 = (*node)->Union();
GiSTentry *e2 = node2->Union();
e1->SetPtr((*node)->Path().Page());
e2->SetPtr(node2->Path().Page());
// Create new root if root is being split
if (bNewRoot) {
GiSTnode *root = NewNode(this);
root->SetLevel((*node)->Level() + 1);
root->InsertBefore(*e1, 0);
root->InsertBefore(*e2, 1);
root->Path().MakeRoot();
WriteNode(root);
delete root;
} else {
// Insert entry for N' in parent
GiSTpath parentPath = (*node)->Path();
parentPath.MakeParent();
GiSTnode *parent = ReadNode(parentPath);
// Find the entry for N in parent
GiSTentry *e = parent->SearchPtr((*node)->Path().Page());
assert(e != NULL);
// Insert the new entry right after it
int pos = e->Position();
parent->DeleteEntry(pos);
parent->InsertBefore(*e1, pos);
parent->InsertBefore(*e2, pos+1);
delete e;
if (!parent->IsOverFull(*store)) {
WriteNode(parent);
} else {
Split(&parent, bLeft? *e1: *e2); // parent is the node which contains the entry inserted
GiSTpage page = (*node)->Path().Page();
(*node)->Path() = parent->Path(); // parent's path may change
(*node)->Path().MakeChild(page);
page = node2->Path().Page();
node2->Path() = (*node)->Path();
node2->Path().MakeSibling(page);
}
delete parent;
}
if (!bLeft) {
delete *node;
*node = node2; // return it
} else {
delete node2;
}
delete e1;
delete e2;
}
}
void
GiST::Split (GiSTnode **node, const GiSTentry& entry)
{
int went_left = 0, new_root = 0;
if ((*node)->Path().IsRoot()) {
new_root = 1;
(*node)->Path().MakeChild(store->Allocate());
}
GiSTnode *node2 = (*node)->PickSplit();
node2->Path().MakeSibling(store->Allocate());
GiSTentry *e = (*node)->SearchPtr(entry.Ptr());
if (e != NULL) {
went_left = 1;
delete e;
}
node2->SetSibling((*node)->Sibling());
(*node)->SetSibling(node2->Path().Page());
WriteNode (*node);
WriteNode (node2);
GiSTentry *e1 = (*node)->Union();
GiSTentry *e2 = node2->Union();
e1->SetPtr((*node)->Path().Page());
e2->SetPtr(node2->Path().Page());
// Create new root if root is being split
if (new_root) {
GiSTnode *root = NewNode (this);
root->SetLevel((*node)->Level() + 1);
root->InsertBefore(*e1, 0);
root->InsertBefore(*e2, 1);
root->Path().MakeRoot();
WriteNode (root);
delete root;
} else {
// Insert entry for N' in parent
GiSTpath parent_path = (*node)->Path();
parent_path.MakeParent ();
GiSTnode *parent = ReadNode (parent_path);
// Find the entry for N in parent
GiSTentry *e = parent->SearchPtr((*node)->Path().Page());
assert (e != NULL);
// Insert the new entry right after it
int pos = e->Position();
parent->DeleteEntry(pos);
parent->InsertBefore(*e1, pos);
parent->InsertBefore(*e2, pos+1);
delete e;
if (!parent->IsOverFull(*store)) {
WriteNode (parent);
} else {
Split (&parent, went_left? *e1: *e2);
GiSTpage page = (*node)->Path().Page();
(*node)->Path() = parent->Path(); // parent's path may changed
(*node)->Path().MakeChild (page);
page = node2->Path().Page();
node2->Path() = (*node)->Path();
node2->Path().MakeSibling (page);
}
delete parent;
}
if (!went_left) {
delete *node;
*node = node2; // return it
} else {
delete node2;
}
delete e1;
delete e2;
}