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 void CompressAndDecompressTest()
{
String reference = "Hello World 0123456789";
byte[] dataToCompress = Encoding.Unicode.GetBytes(reference);
ZLibCompression zLibCompression = new ZLibCompression();
var compressed = zLibCompression.Compress(dataToCompress);
var decompressed = zLibCompression.Decompress(compressed);
Assert.Equal(reference, Encoding.Unicode.GetString(decompressed));
}
private Stream Decompress(BinaryReader reader)
{
var decompressedData = new MemoryStream();
for (var chunk = 0; chunk < _header.DataBlocksCount; chunk++)
{
var compressedChunkSize = reader.ReadUInt16();
var decompressedChunkSize = reader.ReadUInt16();
var checksum = reader.ReadUInt32();
using var compressedDataStream = new MemoryStream();
reader.BaseStream.CopyTo(compressedDataStream, compressedChunkSize, StreamExtensions.DefaultBufferSize);
compressedDataStream.Position = 0;
var decompressedDataBytes = ZLibCompression.Decompress(compressedDataStream, decompressedChunkSize);
decompressedData.Write(decompressedDataBytes, 0, decompressedDataBytes.Length);
}
return(decompressedData);
}
private Stream GetCompressedStream(Stream baseStream, MpqFileFlags targetFlags, MpqCompressionType compressionType, int targetBlockSize)
{
var resultStream = new MemoryStream();
var singleUnit = targetFlags.HasFlag(MpqFileFlags.SingleUnit);
void TryCompress(uint bytes)
{
var offset = baseStream.Position;
var compressedStream = compressionType switch
{
MpqCompressionType.ZLib => ZLibCompression.Compress(baseStream, (int)bytes, true),
_ => throw new NotSupportedException(),
};
// Add one because CompressionType byte not written yet.
var length = compressedStream.Length + 1;
if (!singleUnit && length >= bytes)
{
baseStream.CopyTo(resultStream, offset, (int)bytes, StreamExtensions.DefaultBufferSize);
}
else
{
resultStream.WriteByte((byte)compressionType);
compressedStream.Position = 0;
compressedStream.CopyTo(resultStream);
}
compressedStream.Dispose();
if (singleUnit)
{
baseStream.Dispose();
}
}
var length = (uint)baseStream.Length;
if ((targetFlags & MpqFileFlags.Compressed) == 0)
{
baseStream.CopyTo(resultStream);
}
else if (singleUnit)
{
TryCompress(length);
}
else
{
var blockCount = (uint)((length + targetBlockSize - 1) / targetBlockSize) + 1;
var blockOffsets = new uint[blockCount];
blockOffsets[0] = 4 * blockCount;
resultStream.Position = blockOffsets[0];
for (var blockIndex = 1; blockIndex < blockCount; blockIndex++)
{
var bytesToCompress = blockIndex + 1 == blockCount ? (uint)(baseStream.Length - baseStream.Position) : (uint)targetBlockSize;
TryCompress(bytesToCompress);
blockOffsets[blockIndex] = (uint)resultStream.Position;
}
resultStream.Position = 0;
using (var writer = new BinaryWriter(resultStream, new System.Text.UTF8Encoding(false, true), true))
{
for (var blockIndex = 0; blockIndex < blockCount; blockIndex++)
{
writer.Write(blockOffsets[blockIndex]);
}
}
}
resultStream.Position = 0;
return(resultStream);
}
