public XnbFile <T> Deserialize <T>(Stream stream)
{
if (stream == null)
{
throw new ArgumentNullException(nameof(stream));
}
var xnbResult = new XnbFile <T>();
var xnbStreamReader = new XnbStreamReader(stream);
// check if file starts with XNB
ValidatePrefix(xnbStreamReader);
// read the XNB target OS
xnbResult.XnbTargetOs = ReadTargetOs(xnbStreamReader);
// read the XNB format version
xnbResult.FormatVersion = ReadFormatVersion(xnbStreamReader);
// read the XNB flag
var flags = xnbResult.Flags = ReadFlags(xnbStreamReader);
// read the file size
var size = xnbResult.Size = (int)xnbStreamReader.ReadUInt32();
// check if encoded. If so, decode stream
xnbStreamReader = DecodeXnbStreamReader(xnbStreamReader, flags, size);
var xnbReaderManager = new XnbReaderManager();
xnbReaderManager.ReadReaders(xnbStreamReader);
// ensure there are no shared resources
var sharedResourcesCount = xnbStreamReader.Read7BitEncodedInt();
if (sharedResourcesCount != 0)
{
throw new NotSupportedException("Shared resources are not supported");
}
int readerIndex = xnbStreamReader.Read7BitEncodedInt();
var reader = xnbReaderManager.XnbReaderFromIndex(readerIndex);
if (reader == null)
{
xnbResult.Content = default(T);
}
else if (reader.Read(xnbReaderManager, xnbStreamReader) is T content)
{
xnbResult.Content = content;
}
else
{
throw new XnbException("Invalid type");
}
return(xnbResult);
}
private void ValidatePrefix(XnbStreamReader xnbStreamReader)
{
var prefix = new string(xnbStreamReader.ReadChars(3));
if (prefix != "XNB")
{
throw new XnbException($"Invalid XnbDictionary message, expected XNB, found {prefix}");
}
}
private XnbFormatVersion ReadFormatVersion(XnbStreamReader xnbStreamReader)
{
var formatIndicator = xnbStreamReader.ReadByte();
switch (formatIndicator)
{
case 0x3:
return(XnbFormatVersion.XnaGameStudio30);
case 0x4:
return(XnbFormatVersion.XnaGameStudio31);
case 0x5:
return(XnbFormatVersion.XnaGameStudio40);
default:
return(new XnbFormatVersion(null, 0));
}
}
private XnbTargetOs ReadTargetOs(XnbStreamReader xnbStreamReader)
{
var target = xnbStreamReader.ReadChar();
switch (target)
{
case 'w':
return(XnbTargetOs.MicrosoftWindow);
case 'm':
return(XnbTargetOs.WindowsPhone);
case 'x':
return(XnbTargetOs.Xbox360);
default:
return(XnbTargetOs.Unknown);
}
}
private XnbStreamReader DecodeXnbStreamReader(XnbStreamReader endcodedXnbStreamReader, XnbFlags flags, int size)
{
// check if file size is equal to stream size
if (endcodedXnbStreamReader.BaseStream.Length != size)
{
throw new XnbException("XNB file has been truncated!");
}
// check if stream is compressed
if (!flags.HasFlag(XnbFlags.ContentCompressedLzx))
{
return(endcodedXnbStreamReader);
}
var decompressedSize = (int)endcodedXnbStreamReader.ReadUInt32();
var compressedSize = size - XnbCompressedPrologueSize;
var decompressedStream = new LzxDecoderStream(endcodedXnbStreamReader.BaseStream, decompressedSize, compressedSize);
return(new XnbStreamReader(decompressedStream));
}
public void ReadReaders(XnbStreamReader streamReader)
{
lock (_xnbTypeReaders)
{
if (_resolvedReaders)
{
throw new XnbException("Already resolved readers");
}
_resolvedReaders = true;
int readerCount = streamReader.Read7BitEncodedInt();
for (var i = 0; i < readerCount; i++)
{
string readerName = streamReader.ReadString();
int version = streamReader.ReadInt32();
Type readerType = XnbTypeReaderTypeResolver.ResolveFromName(readerName);
XnbTypeReader reader = XnbReaderFactory.CreateReaderFromType(readerType);
_xnbTypeReaders.Add(reader);
}
}
}
public abstract object Read(XnbReaderManager xnbReaderManager, XnbStreamReader xnbStreamReader);
private XnbFlags ReadFlags(XnbStreamReader xnbStreamReader)
{
return((XnbFlags)xnbStreamReader.ReadByte());
}
