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 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);
}
