private static MemoryStream Decompress(BinaryReader reader, PackedFileHeader header)
{
var blockCount = header.DataBlocksCount;
var decompressedSize = header.DecompressedSize;
var isReforged = header.IsReforgedReplay;
var decompressedData = new MemoryStream();
for (var chunk = 0; chunk < blockCount; chunk++)
{
var compressedChunkSize = reader.ReadUInt16();
if (isReforged)
{
reader.BaseStream.Seek(2, SeekOrigin.Current);
}
var decompressedChunkSize = reader.ReadUInt16();
var checksum = reader.ReadUInt32();
if (isReforged)
{
reader.BaseStream.Seek(2, SeekOrigin.Current);
}
using var compressedDataStream = new MemoryStream();
reader.BaseStream.CopyTo(compressedDataStream, compressedChunkSize, StreamExtensions.DefaultBufferSize);
compressedDataStream.Position = 0;
var decompressedDataBytes = ZLibCompression.Decompress(compressedDataStream, decompressedChunkSize);
var decompressedDataLength = (chunk + 1 == blockCount) ? (int)(decompressedSize - decompressedData.Length) : decompressedChunkSize;
decompressedData.Write(decompressedDataBytes, 0, decompressedDataLength);
}
decompressedData.Position = 0;
return(decompressedData);
}
public static PackedFile Parse(Stream stream, bool leaveOpen = false)
{
var file = new PackedFile();
using (var reader = new BinaryReader(stream, new UTF8Encoding(false, true), leaveOpen))
{
file._header = PackedFileHeader.FromReader(reader);
file._decompressedData = Decompress(reader, file._header);
}
return(file);
}
public static PackedFileHeader FromReader(BinaryReader reader)
{
if (new string(reader.ReadChars(HeaderString.Length)) != HeaderString)
{
throw new InvalidDataException("Invalid file header.");
}
using var crcStream = new MemoryStream();
using var crcWriter = new BinaryWriter(crcStream);
var header = new PackedFileHeader();
header._dataOffset = reader.ReadUInt32();
header._compressedSize = reader.ReadUInt32();
header._headerVersion = reader.ReadUInt32();
header._decompressedSize = reader.ReadUInt32();
header._dataBlocksCount = reader.ReadUInt32();
crcWriter.WriteString(HeaderString);
crcWriter.Write(header._dataOffset);
crcWriter.Write(header._compressedSize);
crcWriter.Write(header._headerVersion);
crcWriter.Write(header._decompressedSize);
crcWriter.Write(header._dataBlocksCount);
if (header._headerVersion == 0x00)
{
if (header._dataOffset != 0x40)
{
throw new InvalidDataException("Invalid header size.");
}
if (reader.ReadUInt16() != 0)
{
throw new InvalidDataException();
}
header._gameVersion = reader.ReadUInt16();
crcWriter.Write((ushort)0);
crcWriter.Write((ushort)header._gameVersion);
}
else if (header._headerVersion == 0x01)
{
if (header._dataOffset != 0x44)
{
throw new InvalidDataException("Invalid header size.");
}
header._gameIdentifier = reader.ReadUInt32();
header._gameVersion = reader.ReadUInt32();
crcWriter.Write(header._gameIdentifier);
crcWriter.Write(header._gameVersion);
}
else
{
throw new NotSupportedException("Only header version 1 is supported.");
}
header._build = reader.ReadUInt16();
header._flags = reader.ReadUInt16();
header._gameLength = reader.ReadUInt32();
header._checksum = reader.ReadUInt32();
crcWriter.Write(header._build);
crcWriter.Write(header._flags);
crcWriter.Write(header._gameLength);
crcWriter.Write(0U);
crcStream.Position = 0;
var crc = new Ionic.Crc.CRC32().GetCrc32(crcStream);
if (crc != header._checksum)
{
throw new InvalidDataException("CRC failed");
}
return(header);
}
