private void SeekDir(IndexInput input, long dirOffset)
{
if (_version >= BlockTermsWriter.VERSION_CHECKSUM)
{
input.Seek(input.Length() - CodecUtil.FooterLength() - 8);
dirOffset = input.ReadLong();
}
else if (_version >= BlockTermsWriter.VERSION_APPEND_ONLY)
{
input.Seek(input.Length() - 8);
dirOffset = input.ReadLong();
}
input.Seek(dirOffset);
}