public Stream GetStream()
{
Stream stream = new Substream(
new FileStream(ArchiveFilename, FileMode.Open, FileAccess.Read, FileShare.Read),
(long)offset,
length);
switch (Compression)
{
case ArchiveFileCompression.LZ4:
return(new LZ4Stream(stream,
LZ4StreamMode.Decompress));
case ArchiveFileCompression.Zstandard:
byte[] output;
using (MemoryStream buffer = new MemoryStream())
{
stream.CopyTo(buffer);
output = buffer.ToArray();
}
using (ZstdNet.Decompressor zstd = new ZstdNet.Decompressor())
return(new MemoryStream(zstd.Unwrap(output), false)); //, (int)_size
case ArchiveFileCompression.Uncompressed:
return(stream);
default:
throw new InvalidOperationException("Compression type is invalid.");
}
}
public static byte[] GetMd5(Stream stream, long offset, long length)
{
MD5 md5 = MD5.Create();
Substream sub = new Substream(stream, offset, length);
return(md5.ComputeHash(sub));
}