private HashMap<String,Integer> loadMap() throws Exception
{
VIntValueReader kr = new VIntValueReader(_file);
final HashMap<String,Integer> result = new HashMap<String,Integer>();
kr.readAll(new KeyValueReader.ValueCallback<Long>() {
@Override
public void handleEntry(byte[] key, Long value) {
// platform-dependant is ok; only have ascii chars:
result.put(new String(key), Integer.valueOf(value.intValue()));
}