class cListSet {
        const int DIVISIONS = 128;

        List<cListEntry>[] entries = new List<cListEntry>[DIVISIONS];

        public bool Add( cListEntry entry ) {
            int hash = entry.GetHashCode();

            if( entries[hash] == null ) {
                // no entry for this hash group exist, adding new
                entries[hash] = new List<cListEntry>();
                entries[hash].Add( entry );
                return true;

            } else {
                // at least the hash group exists
                List<cListEntry> group = entries[hash];
                int index = group.IndexOf(entry);

                if( index != -1 ) {
                    // entry exists, update
                    group[index].lastupdate = DateTime.Now;
                    return false;

                } else {
                    // entry does not exist, add
                    group.Add( entry );
                    return true;
                }
            }
        }
    }