void log(int op, Object el) {
LogEntry entry = new LogEntry();
entry.op = op;
entry.el = el;
List<LogEntry> log = txManager.getContext().getCurrent().getTopLevel().getAttribute(S);
if (log == null) {
log = new ArrayList<LogEntry>();
txManager.getContext().getCurrent().getTopLevel().setAttribute(S, log);
}
log.add(entry);
}
HGSortedSet<E> write() {
List<LogEntry> log = txManager.getContext().getCurrent().getTopLevel().getAttribute(S);
if (log == null) // should we copy-on-write?
{
HGSortedSet<E> readOnly = S.get(); // S.getForWrite();
HGSortedSet<E> writeable = cloneSet(readOnly);
S.put(writeable);
}
return S.get();
}