void movetofront(CacheNode node)
{
if (node == head)
{
return;
}
if (node == tail)
{
tail = tail.prev;// tail is moving once step behind
}
if (node.next != null)
{
node.next.prev = node.prev;
}
node.prev.next = node.next;
node.prev = null;
node.next = head;
head.prev = node;
head = node;
}
void movetoend(CacheNode node)
{
if (node == head)
{
return;
}
if (node == tail)
{
tail = tail.prev;
}
if (node.next != null)
{
node.next.prev = node.prev;
}
node.prev.next = node.next;
node.prev = null;
node.next = head;
head.prev = node;
head = node;
}