public void add(RecordKey key, RecordUpdate data)
{
byte[] keybytes = key.encode();
byte[] databytes = data.encode();
RecordInfo ri;
ri.record_start_pos = _curPos();
ri.key_len = keybytes.Length;
ri.data_len = databytes.Length;
output.Write(keybytes, 0, keybytes.Length);
output.Write(databytes, 0, databytes.Length);
record_offsets.Add(ri);
}