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;
}
}
}
internal CompoundDocument(Stream stream, FileHeader header)
{
this.FileStorage = stream;
this.Reader = new BinaryReader(this.FileStorage);
if (stream.CanWrite)
{
this.Writer = new BinaryWriter(this.FileStorage, Encoding.Unicode);
}
this.Header = header;
this.SectorSize = (int)Math.Pow(2, Header.SectorSizeInPot);
this.ShortSectorSize = (int)Math.Pow(2, Header.ShortSectorSizeInPot);
this.TotalSectors = stream.Length == 0 ? 0
: (int)(stream.Length - 512) / this.SectorSize;
this.MasterSectorAllocation = new MasterSectorAllocation(this);
this.SectorAllocation = new SectorAllocation(this);
this.ShortSectorAllocation = new ShortSectorAllocation(this);
}