@Override
public CRDTMessage remove(UnorderedNode<T> subtree) throws PreconditionException {
if (wcp.lookup().getRoot() == subtree) throw new PreconditionException("Removing root");
if (!wcp.lookup().contains(subtree))
throw new PreconditionException("Removing node " + subtree + " not in the tree");
CRDTMessage msg = null;
for (List<T> w : wcp.toBeRemoved(subtree)) {
CRDTMessage del = words.remove(w);
msg = msg == null ? del : msg.concat(del);
}
return msg;
}
@Override
public CRDTMessage add(UnorderedNode<T> father, T element) throws PreconditionException {
if (!wcp.lookup().contains(father))
throw new PreconditionException("Adding node " + element + " with father not in the tree");
if (father.getChild(element) != null)
throw new PreconditionException("Adding node " + element + " already present under father");
CRDTMessage msg = null;
for (List<T> wf : wcp.addMapping(father)) {
List<T> w = new Word(wf, element);
CRDTMessage add = words.add(w);
msg = msg == null ? add : msg.concat(add);
}
return msg;
}
@Override
public UnorderedNode<T> getRoot() {
return (UnorderedNode<T>) wcp.lookup().getRoot();
}
@Override
public Tree<T> lookup() {
return wcp.lookup();
}
@Override
public synchronized void addObserver(Observer obsrvr) {
super.addObserver(obsrvr);
((HashTree<T>) wcp.lookup()).addObserver(obsrvr);
}