static NbtVersion DetectVersion([NotNull] Stream stream)
{
NbtVersion version = NbtVersion.Legacy;
if (!stream.CanSeek)
{
throw new NotSupportedException("Cannot detect file version on a stream that's not seekable.");
}
int firstByte = stream.ReadByte();
switch (firstByte)
{
case -1:
throw new EndOfStreamException();
case 0x07:
version = NbtVersion.V7;
break;
case 0x08:
version = NbtVersion.V8;
break;
default:
version = NbtVersion.Legacy;
break;
}
stream.Seek(-1, SeekOrigin.Current);
return(version);
}
/// <summary> Loads NBT data from a stream. Existing <c>RootTag</c> will be replaced </summary>
/// <param name="stream"> Stream from which data will be loaded. If compression is set to AutoDetect, this stream must support seeking. </param>
/// <param name="compression"> Compression method to use for loading/saving this file. </param>
/// <param name="version"> Version of the file. </param>
/// <returns> Number of bytes read from the stream. </returns>
/// <exception cref="ArgumentNullException"> <paramref name="stream"/> is <c>null</c>. </exception>
/// <exception cref="ArgumentOutOfRangeException"> If an unrecognized/unsupported value was given for <paramref name="compression"/>. </exception>
/// <exception cref="NotSupportedException"> If <paramref name="compression"/> or <paramref name="version"/> is set to AutoDetect, but the stream is not seekable. </exception>
/// <exception cref="EndOfStreamException"> If file ended earlier than expected. </exception>
/// <exception cref="InvalidDataException"> If file compression could not be detected, decompressing failed, or given stream does not support reading. </exception>
/// <exception cref="NbtFormatException"> If an error occurred while parsing data in NBT format. </exception>
public long LoadFromStream([NotNull] Stream stream, NbtCompression compression, NbtVersion version)
{
return(LoadFromStream(stream, compression, version, null));
}
/// <summary> Loads NBT data from a stream. Existing <c>RootTag</c> will be replaced </summary>
/// <param name="stream"> Stream from which data will be loaded. If compression or file version is set to AutoDetect, this stream must support seeking. </param>
/// <param name="compression"> Compression method to use for loading/saving this file. </param>
/// <param name="version"> Version of the file. </param>
/// <param name="selector"> Optional callback to select which tags to load into memory. Root may not be skipped.
/// No reference is stored to this callback after loading (don't worry about implicitly captured closures). May be <c>null</c>. </param>
/// <returns> Number of bytes read from the stream. </returns>
/// <exception cref="ArgumentNullException"> <paramref name="stream"/> is <c>null</c>. </exception>
/// <exception cref="ArgumentOutOfRangeException"> If an unrecognized/unsupported value was given for <paramref name="compression"/>. </exception>
/// <exception cref="NotSupportedException"> If <paramref name="compression"/> or <paramref name="fileVersion"/> is set to AutoDetect, but the stream is not seekable. </exception>
/// <exception cref="EndOfStreamException"> If file ended earlier than expected. </exception>
/// <exception cref="InvalidDataException"> If file compression could not be detected, decompressing failed, or given stream does not support reading. </exception>
/// <exception cref="NbtFormatException"> If an error occurred while parsing data in NBT format. </exception>
public long LoadFromStream([NotNull] Stream stream, NbtCompression compression, NbtVersion version, [CanBeNull] TagSelector selector)
{
if (stream == null)
{
throw new ArgumentNullException("stream");
}
FileName = null;
if (version == NbtVersion.AutoDetect)
{
FileVersion = DetectVersion(stream);
}
else
{
FileVersion = version;
}
if (FileVersion == NbtVersion.Legacy)
{
// detect compression, based on the first byte
if (compression == NbtCompression.AutoDetect)
{
FileCompression = DetectCompression(stream);
}
else
{
FileCompression = compression;
}
}
else
{
FileCompression = NbtCompression.None;
BigEndian = false;
}
// prepare to count bytes read
long startOffset = 0;
if (stream.CanSeek)
{
startOffset = stream.Position;
}
else
{
stream = new ByteCountingStream(stream);
}
switch (FileCompression)
{
case NbtCompression.GZip:
using (var decStream = new GZipStream(stream, CompressionMode.Decompress, true)) {
if (bufferSize > 0)
{
LoadFromStreamInternal(new BufferedStream(decStream, bufferSize), selector);
}
else
{
LoadFromStreamInternal(decStream, selector);
}
}
break;
case NbtCompression.None:
LoadFromStreamInternal(stream, selector);
break;
case NbtCompression.ZLib:
if (stream.ReadByte() != 0x78)
{
throw new InvalidDataException(WrongZLibHeaderMessage);
}
stream.ReadByte();
using (var decStream = new DeflateStream(stream, CompressionMode.Decompress, true)) {
if (bufferSize > 0)
{
LoadFromStreamInternal(new BufferedStream(decStream, bufferSize), selector);
}
else
{
LoadFromStreamInternal(decStream, selector);
}
}
break;
default:
throw new ArgumentOutOfRangeException("compression");
}
// report bytes read
if (stream.CanSeek)
{
return(stream.Position - startOffset);
}
else
{
return(((ByteCountingStream)stream).BytesRead);
}
}
