private void Set(Node x, bool w, Node n)
{
if (w)
{
x.SetLeft(n);
}
else
{
x.SetRight(n);
}
if (n != null)
{
n.SetParent(x);
}
}
public void Delete(object[] row, bool datatoo)
{
Node x = Search(row);
if (x == null)
{
return;
}
Node n;
if (x.GetLeft() == null)
{
n = x.GetRight();
}
else if (x.GetRight() == null)
{
n = x.GetLeft();
}
else
{
Node d = x;
x = x.GetLeft();
// todo: this can be improved
while (x.GetRight() != null)
{
if (Trace.StopEnabled)
{
Trace.Stop();
}
x = x.GetRight();
}
// x will be replaced with n later
n = x.GetLeft();
// swap d and x
int b = x.GetBalance();
x.SetBalance(d.GetBalance());
d.SetBalance(b);
// set x.parent
Node xp = x.GetParent();
Node dp = d.GetParent();
if (d == _root)
{
_root = x;
}
x.SetParent(dp);
if (dp != null)
{
if (dp.GetRight().Equals(d))
{
dp.SetRight(x);
}
else
{
dp.SetLeft(x);
}
}
// for in-memory tables we could use: d.rData=x.rData;
// but not for cached tables
// relink d.parent, x.left, x.right
if (xp == d)
{
d.SetParent(x);
if (d.GetLeft().Equals(x))
{
x.SetLeft(d);
x.SetRight(d.GetRight());
}
else
{
x.SetRight(d);
x.SetLeft(d.GetLeft());
}
}
else
{
d.SetParent(xp);
xp.SetRight(d);
x.SetRight(d.GetRight());
x.SetLeft(d.GetLeft());
}
x.GetRight().SetParent(x);
x.GetLeft().SetParent(x);
// set d.left, d.right
d.SetLeft(n);
if (n != null)
{
n.SetParent(d);
}
d.SetRight(null);
x = d;
}
bool way = From(x);
Replace(x, n);
n = x.GetParent();
x.Delete();
if (datatoo)
{
x.rData.Delete();
}
while (n != null)
{
if (Trace.StopEnabled)
{
Trace.Stop();
}
x = n;
int sign = way ? 1 : -1;
switch (x.GetBalance() * sign)
{
case -1:
x.SetBalance(0);
break;
case 0:
x.SetBalance(sign);
return;
case 1:
Node r = Child(x, !way);
int b = r.GetBalance();
if (b * sign >= 0)
{
Replace(x, r);
Set(x, !way, Child(r, way));
Set(r, way, x);
if (b == 0)
{
x.SetBalance(sign);
r.SetBalance(-sign);
return;
}
x.SetBalance(0);
r.SetBalance(0);
x = r;
}
else
{
Node l = Child(r, way);
Replace(x, l);
b = l.GetBalance();
Set(r, way, Child(l, !way));
Set(l, !way, r);
Set(x, !way, Child(l, way));
Set(l, way, x);
x.SetBalance((b == sign) ? -sign : 0);
r.SetBalance((b == -sign) ? sign : 0);
l.SetBalance(0);
x = l;
}
break;
}
way = From(x);
n = x.GetParent();
}
}
private void Set(Node x, bool w, Node n)
{
if (w)
{
x.SetLeft(n);
}
else
{
x.SetRight(n);
}
if (n != null)
{
n.SetParent(x);
}
}
