public void ShouldDifferOnBitSwitch()
{
var adler32 = new Adler32();
var hash1 = adler32.ComputeHash(Encoding.Default.GetBytes("00001"));
var hash2 = adler32.ComputeHash(Encoding.Default.GetBytes("00010"));
CollectionAssert.AreNotEqual(hash1, hash2);
}
private static bool VerifyEntry(ArcEntry entry, IProgress?progress)
{
var buffer = ArrayPool <byte> .Shared.Rent(BufferSize);
try
{
using var inputStream = entry.Open();
var hash = new Adler32();
while (true)
{
var bytesInBuffer = inputStream.Read(buffer);
if (bytesInBuffer == 0)
{
break;
}
hash.ComputeHash(buffer, 0, bytesInBuffer);
progress?.AddValue(bytesInBuffer);
}
return(entry.Hash == hash.Hash);
}
finally
{
ArrayPool <byte> .Shared.Return(buffer);
}
}
public static void Compress(Stream originalStream, Stream compressedStream)
{
uint checksum = 0;
using (var checksumStream = new MemoryStream())
{
var position = originalStream.Position;
originalStream.CopyTo(checksumStream);
originalStream.Seek(position, SeekOrigin.Begin);
var buffer = checksumStream.ToArray();
checksum = Adler32.ComputeHash(buffer);
}
compressedStream.Write(new byte[] { 0x78, 0x9C }, 0, 2);
using (var compressionStream = new DeflateStream(compressedStream, CompressionLevel.Optimal, true))
{
originalStream.Seek(0, SeekOrigin.Begin);
originalStream.CopyTo(compressionStream);
}
compressedStream.Write(new byte[]
{
(byte)(checksum >> 24),
(byte)(checksum >> 16),
(byte)(checksum >> 8),
(byte)checksum
}, 0, 4);
}
public void ShouldReturnSameHashForMultipleCalls()
{
var adler32 = new Adler32();
byte[] previous = null;
for (int i = 0; i < 100; i++)
{
var actual = adler32.ComputeHash(
Encoding.Default.GetBytes("Lorem ipsum dolor sit amet, consectetur adipiscing elit. Mauris porta ex quis volutpat hendrerit. Vivamus consequat venenatis velit sit amet varius."));
if (previous != null)
{
CollectionAssert.AreEqual(previous, actual);
}
previous = actual;
}
}