CL_VoidPtr CL_GenericBTree::ItemWithRank (long rank) const
{
short pos;
bool found;
CL_VoidPtr itm;
CL_GenericBTreeNode* tmp_ptr, *p1;
tmp_ptr = _nodeSpace->BorrowRoot ();
if (!tmp_ptr || tmp_ptr->_keyCount <= 0)
return NULL;
rank = minl (maxl (rank, 0), tmp_ptr->_subtreeSize-1);
do {
if (tmp_ptr->_isLeaf) {
assert ((0 <= rank && rank <= tmp_ptr->_keyCount-1),
("Internal error: CL_GenericBTree::ItemWithRank:"
"bad key count %d rank %ld", tmp_ptr->_keyCount, rank));
CL_VoidPtr ret = tmp_ptr->_item[rank];
_nodeSpace->ReturnNode (tmp_ptr);
return ret;
}
// We're in a non-leaf, so find the subtree to descend into
// (if any)
short i;
for (i = 0; i < tmp_ptr->_keyCount; i++) {
p1 = _nodeSpace->BorrowNode (tmp_ptr->_subtree[i]);
if (p1->_subtreeSize > rank)
break;
rank -= p1->_subtreeSize; // Account for i-th subtree
_nodeSpace->ReturnNode (p1);
if (rank == 0) {
// We've got the item we wanted
CL_VoidPtr ret = tmp_ptr->_item[i];
_nodeSpace->ReturnNode (tmp_ptr);
return ret;
}
rank--; // Account for i-th key in node
}
if (i >= tmp_ptr->_keyCount) {
// Descend into rightmost subtree
p1 = _nodeSpace->BorrowNode (tmp_ptr->_subtree[i]);
}
_nodeSpace->ReturnNode (tmp_ptr);
tmp_ptr = p1;
} while (1);
}
static int TDFXReadChipLongMMIO(TDFXPtr pTDFX, int chip, int addr) {
return minl(pTDFX->MMIOBase[chip], addr);
}
