@Override
public void remove_child(ChildPtr ref, byte c) {
assert (refcount <= 1);
// Delete the child, leaving a hole in children. We can't shift children
// because that would require decrementing many elements of keys
int pos = to_uint(keys[to_uint(c)]);
keys[to_uint(c)] = 0;
children[pos - 1].decrement_refcount();
children[pos - 1] = null;
num_children--;
if (num_children == 12) {
ArtNode16 result = new ArtNode16(this);
ref.change(result);
}
}
@Override
public void add_child(ChildPtr ref, byte c, Node child) {
assert (refcount <= 1);
if (this.num_children < 48) {
// Have to do a linear scan because deletion may create holes in
// children array
int pos = 0;
while (children[pos] != null) pos++;
this.children[pos] = child;
child.refcount++;
this.keys[to_uint(c)] = (byte) (pos + 1);
this.num_children++;
} else {
// Copy the node48 into a new node256
ArtNode256 result = new ArtNode256(this);
// Update the parent pointer to the node256
ref.change(result);
// Insert the element into the node256 instead
result.add_child(ref, c, child);
}
}