internal MpqFile(ulong?hashedName, MpqStream mpqStream, MpqFileFlags flags, MpqLocale locale, bool leaveOpen)
{
_name = hashedName;
_mpqStream = mpqStream ?? throw new ArgumentNullException(nameof(mpqStream));
_isStreamOwner = !leaveOpen;
_flags = flags;
_locale = locale;
_compressionType = MpqCompressionType.ZLib;
}
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);
}
internal Stream Transform(MpqFileFlags targetFlags, MpqCompressionType compressionType, uint targetFilePosition, int targetBlockSize)
{
using var memoryStream = new MemoryStream();
CopyTo(memoryStream);
memoryStream.Position = 0;
var fileSize = memoryStream.Length;
using var compressedStream = GetCompressedStream(memoryStream, targetFlags, compressionType, targetBlockSize);
var compressedSize = (uint)compressedStream.Length;
var resultStream = new MemoryStream();
var blockPosCount = (uint)(((int)fileSize + targetBlockSize - 1) / targetBlockSize) + 1;
if (targetFlags.HasFlag(MpqFileFlags.Encrypted) && blockPosCount > 1)
{
var blockPositions = new int[blockPosCount];
var singleUnit = targetFlags.HasFlag(MpqFileFlags.SingleUnit);
var hasBlockPositions = !singleUnit && ((targetFlags & MpqFileFlags.Compressed) != 0);
if (hasBlockPositions)
{
for (var blockIndex = 0; blockIndex < blockPosCount; blockIndex++)
{
using (var br = new BinaryReader(compressedStream, new UTF8Encoding(), true))
{
for (var i = 0; i < blockPosCount; i++)
{
blockPositions[i] = (int)br.ReadUInt32();
}
}
compressedStream.Seek(0, SeekOrigin.Begin);
}
}
else
{
if (singleUnit)
{
blockPosCount = 2;
}
blockPositions[0] = 0;
for (var blockIndex = 2; blockIndex < blockPosCount; blockIndex++)
{
blockPositions[blockIndex - 1] = targetBlockSize * (blockIndex - 1);
}
blockPositions[blockPosCount - 1] = (int)compressedSize;
}
var encryptionSeed = _baseEncryptionSeed;
if (targetFlags.HasFlag(MpqFileFlags.BlockOffsetAdjustedKey))
{
encryptionSeed = MpqEntry.AdjustEncryptionSeed(encryptionSeed, targetFilePosition, (uint)fileSize);
}
var currentOffset = 0;
using (var writer = new BinaryWriter(resultStream, new UTF8Encoding(false, true), true))
{
for (var blockIndex = hasBlockPositions ? 0 : 1; blockIndex < blockPosCount; blockIndex++)
{
var toWrite = blockPositions[blockIndex] - currentOffset;
var data = StormBuffer.EncryptStream(compressedStream, (uint)(encryptionSeed + blockIndex - 1), currentOffset, toWrite);
writer.Write(data);
currentOffset += toWrite;
}
}
}
else
{
compressedStream.CopyTo(resultStream);
}
resultStream.Position = 0;
return(resultStream);
}
