// 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
MT::CollectStats ()
{
GiSTpath path;
path.MakeRoot ();
GiSTnode *node = ReadNode (path);
if (!node->IsLeaf()) {
int maxLevel = node->Level();
double *radii = new double[maxLevel];
int *pages = new int[maxLevel];
for (int i=0; i<maxLevel; i++) {
pages[i] = 0;
radii[i] = 0;
}
TruePredicate truePredicate;
GiSTlist<GiSTentry*> list = node->Search(truePredicate); // retrieve all the entries in this node
double overlap = ((MTnode *)node)->Overlap();
double totalOverlap = overlap;
delete node;
while (!list.IsEmpty()) {
GiSTentry *entry = list.RemoveFront ();
path.MakeChild (entry->Ptr());
node = ReadNode (path);
overlap = ((MTnode *)node)->Overlap();
totalOverlap += overlap;
pages[node->Level()]++;
radii[node->Level()] += ((MTkey *) entry->Key())->MaxRadius();
GiSTlist<GiSTentry*> newlist;
if (!node->IsLeaf()) {
newlist = node->Search(truePredicate); // recurse to next level
}
while (!newlist.IsEmpty()) {
list.Append (newlist.RemoveFront ());
}
path.MakeParent ();
delete entry;
delete node;
}
// output the results
cout << "Level:\tPages:\tAverage_Radius:"<<endl;
int totalPages = 1; // for the root
for (int i=maxLevel-1; i>=0; i--) {
totalPages += pages[i];
cout << i << ":\t" << pages[i] << "\t" << radii[i]/pages[i] << endl;
}
cout << "TotalPages:\t" << totalPages << endl;
cout << "LeafPages:\t" << pages[0] << endl;
cout << "TotalOverlap:\t" << (float)totalOverlap << endl;
delete []radii;
delete []pages;
} else {
delete node;
}
}
