/**
* reinsert the given <code>extension</code> before the <code>next</code> one in the ring
*
* @param extension
* @param next
*/
public final void relink(
final MinExtension<NodeType, EdgeType> extension,
final MinExtension<NodeType, EdgeType> next) {
extension.backward = next.backward;
next.backward.forward = extension;
extension.forward = next;
next.backward = extension;
}
/**
* remove the given <code>extension</code> from the ring
*
* @param extension
* @return the extension after the removed one
*/
public final MinExtension<NodeType, EdgeType> unlink(
final MinExtension<NodeType, EdgeType> extension) {
final MinExtension<NodeType, EdgeType> next = extension.forward;
// remove ack
extension.backward.forward = next;
next.backward = extension.backward;
extension.forward = extension.backward = null;
return next;
}
/**
* finally remove the given <code>extension</code>
*
* @param extension
* @return <code>true</code>, if removed correctly
*/
public boolean removeAndFree(final MinExtension<NodeType, EdgeType> extension) {
if (extension.forward == null || extension.backward == null) {
return false;
}
extension.forward.backward = extension.backward;
extension.backward.forward = extension.forward;
extension.backward = extension.forward = null;
extension.release(tenv);
--size;
return true;
}
/**
* inserts the given <code>extension</code>
*
* @param extension
* @return <code>true</code>, if correctly added
*/
public boolean add(final MinExtension<NodeType, EdgeType> extension) {
if (extension.forward != null || extension.backward != null) {
return false;
}
MinExtension<NodeType, EdgeType> ack = this;
while (ack.forward.compareTo(extension) < 0) {
ack = ack.forward;
}
extension.forward = ack.forward;
extension.backward = ack;
ack.forward = extension.forward.backward = extension;
++size;
return true;
}
/**
* finally remove the given <code>extension</code> and all extensions that are connected with the
* given on
*
* @param ext
* @return <code>true</code>, if removed correctly
*/
public boolean removeAndFreeAll(MinExtension<NodeType, EdgeType> ext) {
boolean ret = true;
while (ext != null) {
final MinExtension<NodeType, EdgeType> next = (MinExtension<NodeType, EdgeType>) ext.next;
ext.next = null;
ret = ret && removeAndFree(ext);
ext = next;
}
return ret;
}
