private void AppendStreamData(int startSID, int streamLength, byte[] data)
        {
            int sid      = startSID;
            int next_sid = SectorAllocation.GetNextSectorID(sid);
            int index    = 0;

            while (next_sid != SID.EOC)
            {
                sid      = next_sid;
                next_sid = SectorAllocation.GetNextSectorID(sid);
                index   += SectorSize;
            }
            if (index < streamLength)
            {
                int position = streamLength - index;
                int length   = SectorSize - position;
                if (data.Length <= length)
                {
                    WriteInSector(sid, position, data, 0, data.Length);
                }
                else
                {
                    WriteInSector(sid, position, data, 0, length);
                    next_sid = AllocateDataSectorAfter(sid);
                    byte[] remained_data = new byte[data.Length - length];
                    Array.Copy(data, length, remained_data, 0, remained_data.Length);
                    WriteStreamData(next_sid, remained_data);
                }
            }
            else
            {
                next_sid = AllocateDataSectorAfter(sid);
                WriteStreamData(next_sid, data);
            }
        }
        internal void WriteStreamData(int startSID, byte[] data)
        {
            int prev_sid = SID.EOC;
            int sid      = startSID;
            int index    = 0;

            while (index < data.Length)
            {
                if (sid == SID.EOC)
                {
                    if (prev_sid == SID.EOC)
                    {
                        sid = this.AllocateDataSector();
                    }
                    else
                    {
                        sid = this.AllocateDataSectorAfter(prev_sid);
                    }
                }
                int offset = GetSectorOffset(sid);
                Writer.BaseStream.Position = offset;
                if (index + SectorSize < data.Length)
                {
                    Writer.Write(data, index, SectorSize);
                }
                else
                {
                    Writer.Write(data, index, data.Length - index);
                }
                index   += SectorSize;
                prev_sid = sid;
                sid      = this.SectorAllocation.GetNextSectorID(prev_sid);
            }
            if (sid != SID.EOC && prev_sid != SID.EOC)
            {
                SectorAllocation.LinkSectorID(prev_sid, SID.EOC);
                while (sid != SID.EOC)
                {
                    int next_sid = SectorAllocation.GetNextSectorID(sid);
                    SectorAllocation.LinkSectorID(sid, SID.Free);
                    sid = next_sid;
                }
            }
        }