private SwStorage Process(Stream stream)
{
byte[] blob = StreamHelper.ReadToEnd(m_stream);
int index = 0;
// yet unknown the first bytes
uint header = GetUInt(blob, index);
index += 4;
index += 3; // skip 3 bytes
// there seems to be an key for scrambling strings
uint key = blob[index];
index += 1;
SwStorage storage = new SwStorage(header, key);
for (; index < blob.Length; index++)
{
// TODO: find a way to recognize if the table of contents starts
SwStorageChunkInfo chunk = ReadChunk(storage, blob, index);
if (chunk == null)
{
//readContentTable(blob, index);
break;
}
storage.AddChunk(chunk);
int nextOffset = index + (int)chunk.GetLength();
index = nextOffset - 1; // for !
}
return(storage);
}
public void AddChunk(SwStorageChunkInfo chunk)
{
this.m_chunks.Add(chunk);
}
private static SwStorageChunkInfo ReadChunk(SwStorage storage, byte[] blob, int startIndex)
{
// within a block before offset 0x12 the bytes are yet unknown
int index = startIndex + 0x12;
uint compressedSize = GetUInt(blob, index);
index += 4;
uint uncompressedSize = GetUInt(blob, index);
index += 4;
int nameSize = (int)GetUInt(blob, index);
index += 4;
int namestart = index;
if (namestart + nameSize > blob.Length)
{
// happens if we try to read the content table
return(null);
}
// the stream names are scrambled ;-)
byte[] unrolName = new byte[nameSize];
for (; index < namestart + nameSize; index++)
{
byte unroledByte = Rol(blob[index], (int)storage.Key);
unrolName[index - namestart] = unroledByte;
}
string chunkName = Encoding.UTF8.GetString(unrolName);
if (string.IsNullOrEmpty(chunkName))
{
chunkName = "un_" + Guid.NewGuid().ToString();
}
int compressedDataStart = namestart + nameSize;
SwStorageChunkInfo chunkInfo = new SwStorageChunkInfo();
chunkInfo.ChunkOffset = (uint)startIndex;
chunkInfo.CompressedSize = compressedSize;
chunkInfo.StartCompressedBlock = compressedDataStart;
chunkInfo.ChunkName = chunkName;
chunkInfo.HeaderLength = compressedDataStart - startIndex;
if (uncompressedSize > 0)
{
byte[] uncompressedData = new byte[uncompressedSize];
ZlibCodec inflator = new ZlibCodec();
inflator.InitializeInflate(false);
inflator.InputBuffer = blob;
inflator.AvailableBytesIn = (int)compressedSize;
inflator.AvailableBytesOut = (int)uncompressedSize;
inflator.NextIn = compressedDataStart;
inflator.OutputBuffer = uncompressedData;
inflator.NextOut = 0;
inflator.Inflate(FlushType.Full);
inflator.EndInflate();
chunkInfo.Chunk = uncompressedData;
}
else
{
chunkInfo.Chunk = new byte[0];
}
return(chunkInfo);
}
