// adjust the keys of node, which is used during the final phase of the BulkLoad algorithm
void
MT::AdjKeys (GiSTnode *node)
{
if (node->Path().IsRoot()) {
return;
}
GiSTpath parentPath = node->Path();
parentPath.MakeParent ();
GiSTnode *parentNode = ReadNode (parentPath);
GiSTentry *parentEntry = parentNode->SearchPtr(node->Path().Page()); // parent entry
assert (parentEntry != NULL);
GiSTentry *unionEntry = node->Union();
unionEntry->SetPtr(node->Path().Page());
((MTkey *) unionEntry->Key())->distance = ((MTkey *) parentEntry->Key())->distance; // necessary to keep track of the distance from the parent
if (!parentEntry->IsEqual(*unionEntry)) { // replace this entry
parentNode->DeleteEntry(parentEntry->Position());
parentNode->Insert(*unionEntry);
WriteNode (parentNode);
AdjKeys (parentNode);
}
delete unionEntry;
delete parentEntry;
delete parentNode;
}
void
GiST::InsertHelper(const GiSTentry &entry,
int level, // level of tree at which to insert
int *splitvec) // a vector to trigger Split instead of forced reinsert
{
GiSTnode *leaf;
int overflow=0;
leaf=ChooseSubtree(GiSTRootPage, entry, level);
leaf->Insert(entry);
if (leaf->IsOverFull(*store)) {
if(ForcedReinsert()&&!leaf->Path().IsRoot()&&(!splitvec||!splitvec[level])) {
int split[GIST_MAX_LEVELS];
// R*-tree-style forced reinsert
for(int i=0; i<GIST_MAX_LEVELS; i++) split[i]=0;
OverflowTreatment(leaf, entry, split);
overflow=1;
}
else Split(&leaf, entry);
if(leaf->IsOverFull(*store)) {
// we only should get here if we reinserted, and the node re-filled
assert(overflow);
leaf->DeleteEntry(entry.Position());
Split(&leaf, entry);
}
}
else WriteNode(leaf);
if(!overflow) AdjustKeys(leaf, NULL);
delete leaf;
}
void
GiST::Delete (const GiSTpredicate& pred)
{
GiSTcursor *c = Search (pred);
GiSTentry *e;
do {
if (c == NULL) {
return;
}
e = c->Next();
GiSTpath path = c->Path();
delete c;
if (e == NULL) {
return;
}
// Read in the node that this belongs to
GiSTnode *node = ReadNode (path);
node->DeleteEntry(e->Position());
WriteNode (node);
int condensed = CondenseTree (node);
delete node;
if (condensed) {
ShortenTree ();
// because the tree changed, we need to search all over again!
// XXX - this is inefficient! users may want to avoid condensing.
c = Search (pred);
}
} while (e != NULL);
}
void
GiST::AdjustKeys (GiSTnode *node, GiSTnode **parent)
{
if (node->Path().IsRoot()) {
return;
}
GiSTnode *P;
// Read in node's parent
if (parent == NULL) {
GiSTpath parent_path = node->Path();
parent_path.MakeParent ();
P = ReadNode (parent_path);
parent = &P;
} else {
P = *parent;
}
// Get the old entry pointing to node
GiSTentry *entry = P->SearchPtr(node->Path().Page());
assert (entry != NULL);
// Get union of node
GiSTentry *actual = node->Union();
WriteNode(node); // added by myself for the splitted = false;
actual->SetPtr(node->Path().Page());
if (!entry->IsEqual(*actual)) {
int pos = entry->Position();
P->DeleteEntry(pos);
P->InsertBefore(*actual, pos);
// A split may be necessary.
// XXX: should we do Forced Reinsert here too?
if (P->IsOverFull(*store)) {
Split (parent, *actual);
GiSTpage page = node->Path().Page();
node->Path() = P->Path();
node->Path().MakeChild(page);
} else {
WriteNode (P);
AdjustKeys (P, NULL);
}
}
if (parent == &P) {
delete P;
}
delete actual;
delete entry;
}
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;
}
// handle underfull leaf nodes
int
GiST::CondenseTree (GiSTnode *leaf)
{
GiSTlist<GiSTentry*> Q;
int deleted = 0;
// Must be condensing a leaf
assert (leaf->IsLeaf());
while (!leaf->Path().IsRoot()) {
GiSTpath parent_path = leaf->Path();
parent_path.MakeParent ();
GiSTnode *P = ReadNode (parent_path);
GiSTentry *En = P->SearchPtr(leaf->Path().Page());
assert (En != NULL);
// Handle under-full node
if (leaf->IsUnderFull(*store)) {
if (!IsOrdered()) {
TruePredicate truePredicate;
GiSTlist<GiSTentry*> list = leaf->Search(truePredicate);
while (!list.IsEmpty()) {
GiSTentry *e = list.RemoveFront();
Q.Append (e);
}
P->DeleteEntry(En->Position());
WriteNode (P);
deleted = 1;
AdjustKeys (P, NULL);
} else {
// Try to borrow entries, else coalesce with a neighbor
GiSTpage neighbor_page = P->SearchNeighbors(leaf->Path().Page()); // right and then left
if (neighbor_page != 0) {
GiSTpath neighbor_path = leaf->Path();
neighbor_path.MakeSibling (neighbor_page);
GiSTnode *neighbor;
if (leaf->Sibling() == neighbor_page) { // RIGHT sibling...
neighbor = ReadNode (neighbor_path);
} else { // LEFT sibling
neighbor = leaf;
leaf = ReadNode (neighbor_path);
}
leaf->Coalesce(*neighbor);
// If not overfull, coalesce, kill right node
if (!leaf->IsOverFull(*store)) {
leaf->SetSibling(neighbor->Sibling());
WriteNode (leaf);
// Delete the neighbor from parent
GiSTentry *e = P->SearchPtr(neighbor->Path().Page());
P->DeleteEntry(e->Position());
WriteNode (P);
delete e;
store->Deallocate(neighbor->Path().Page());
deleted = 1;
} else { // If overfull, split (same as borrowing)
GiSTnode *node2 = leaf->PickSplit();
node2->Path() = neighbor->Path();
node2->SetSibling(neighbor->Sibling());
WriteNode (leaf);
WriteNode (node2);
AdjustKeys (node2, &P);
delete node2;
deleted = 1;
}
delete neighbor;
}
}
}
// Adjust covering predicate
if (!deleted) {
AdjustKeys (leaf, &P);
}
parent_path = leaf->Path();
parent_path.MakeParent ();
delete leaf;
// Propagate deletes
if (!deleted) {
break;
}
leaf = P;
}
// Re-insert orphaned entries
while (!Q.IsEmpty()) {
GiSTentry *e = Q.RemoveFront ();
InsertHelper (*e, e->Level());
delete e;
}
return (deleted);
}