static long raf_findEndOfLine(RandomAccessFile raf, long pos, int bufSize) ctex {
  byte[] buf = new byte[bufSize];
  long length = raf.length();
  while (pos < length) {
    raf.seek(pos);
    raf.readFully(buf, 0, (int) min(length-pos, bufSize));
    int idx = indexOf_byteArray(buf, (byte) '\n');
    if (idx >= 0) ret pos+idx+1;
    pos = start+bufSize;
  }
  ret length;
}