bool UpdateData::BuildPacket(WorldPacket *packet, bool hasTransport)
{
    //ByteBuffer buf(m_data.size() + 10 + m_outOfRangeGUIDs.size()*8);
    ByteBuffer buf(4 + 1 + (m_outOfRangeGUIDs.empty() ? 0 : 1 + 4 + 9 * m_outOfRangeGUIDs.size()) + m_data.size());

    buf << uint32(!m_outOfRangeGUIDs.empty() ? m_blockCount + 1 : m_blockCount);
    buf << uint8(hasTransport ? 1 : 0);

    if (!m_outOfRangeGUIDs.empty())
    {
        buf << uint8(UPDATETYPE_OUT_OF_RANGE_OBJECTS);
        buf << uint32(m_outOfRangeGUIDs.size());

        for (std::set<uint64>::const_iterator i = m_outOfRangeGUIDs.begin();
            i != m_outOfRangeGUIDs.end(); i++)
        {
            //buf.appendPackGUID(*i);
            buf << uint8(0xFF);
            buf << uint64(*i);
        }
    }

    buf.append(m_data);

    packet->clear();

    if (m_data.size() > 50)
    {
        uint32 destsize = buf.size() + buf.size()/10 + 16;
        packet->resize(destsize);

        packet->put(0, (uint32)buf.size());

        Compress(const_cast<uint8*>(packet->contents()) + sizeof(uint32),
            &destsize,
            (void*)buf.contents(),
            buf.size());
        if (destsize == 0)
            return false;

        packet->resize(destsize + sizeof(uint32));
        packet->SetOpcode(SMSG_COMPRESSED_UPDATE_OBJECT);
    }
    else
    {
        packet->append(buf);
        packet->SetOpcode(SMSG_UPDATE_OBJECT);
    }

    return true;
}