private void WriteData(Stream stream)
{
if (_originalStream != null)
{
WriteOriginalData(stream);
return;
}
bool closeFileStream = false;
if (_fileStream == null)
{
_fileStream = File.OpenRead(_fileName);
closeFileStream = true;
}
long startPosition = stream.Position;
_uncompressedSize = 0;
_compressedSize = 0;
_crc32 = Crc32Hash.DefaultSeed;
Stream outStream = stream;
if (CompressionMethod == (uint)CompressionType.Deflate)
{
outStream = new DeflateStream(stream, CompressionMode.Compress, CompressionLevel.BestCompression, true);
}
int bytesRead;
var buffer = new byte[WriteBufferSize];
do
{
bytesRead = _fileStream.Read(buffer, 0, WriteBufferSize);
if (bytesRead <= 0)
{
break;
}
_uncompressedSize += (uint)bytesRead;
outStream.Write(buffer, 0, bytesRead);
_crc32 = Crc32Hash.CalculateHash(_crc32, buffer, bytesRead);
} while (bytesRead == WriteBufferSize);
_crc32 ^= Crc32Hash.DefaultSeed;
outStream.Flush();
if (CompressionMethod == (uint)CompressionType.Deflate)
{
outStream.Close();
}
_compressedSize = (uint)(stream.Position - startPosition);
if (closeFileStream)
{
_fileStream.Close();
_fileStream = null;
}
}
public static uint CalculateHash(string fileSystemPath)
{
uint crc32 = Crc32Hash.DefaultSeed;
using (var stream = File.OpenRead(fileSystemPath))
{
int bytesRead;
var buffer = new byte[BufferSize];
do
{
bytesRead = stream.Read(buffer, 0, BufferSize);
if (bytesRead <= 0)
{
break;
}
crc32 = Crc32Hash.CalculateHash(crc32, buffer, bytesRead);
} while (bytesRead == BufferSize);
crc32 ^= Crc32Hash.DefaultSeed;
}
return(crc32);
}
