public async Task ComputeHashAsync_SupportsCancellation()
{
using (CancellationTokenSource cancellationSource = new CancellationTokenSource(100))
using (PositionValueStream stream = new SlowPositionValueStream(10000))
using (HashAlgorithm hash = new SummingTestHashAlgorithm())
{
await Assert.ThrowsAnyAsync <OperationCanceledException>(
() => hash.ComputeHashAsync(stream, cancellationSource.Token));
}
}
public void ComputeHashAsync_RequiresStream()
{
using (HashAlgorithm hash = new SummingTestHashAlgorithm())
{
AssertExtensions.Throws <ArgumentNullException>(
"inputStream",
() =>
{
// Not returning or awaiting the Task, it never got created.
hash.ComputeHashAsync(null);
});
}
}
public void ComputeHashAsync_Disposed()
{
using (PositionValueStream stream = new SlowPositionValueStream(10000))
using (HashAlgorithm hash = new SummingTestHashAlgorithm())
{
hash.Dispose();
Assert.Throws <ObjectDisposedException>(
() =>
{
// Not returning or awaiting the Task, it never got created.
hash.ComputeHashAsync(stream);
});
}
}
public void SpanMethodsUsed_NotOverridden_ArrayMethodsInvoked()
{
byte[] input = Enumerable.Range(0, 1024).Select(i => (byte)i).ToArray();
byte[] output;
int bytesWritten;
var testAlgorithm = new SummingTestHashAlgorithm();
output = new byte[sizeof(long) - 1];
Assert.False(testAlgorithm.TryComputeHash(input, output, out bytesWritten));
Assert.Equal(0, bytesWritten);
Assert.Equal <byte>(new byte[sizeof(long) - 1], output);
output = new byte[sizeof(long)];
Assert.True(testAlgorithm.TryComputeHash(input, output, out bytesWritten));
Assert.Equal(sizeof(long), bytesWritten);
Assert.Equal(input.Sum(b => (long)b), BitConverter.ToInt64(output, 0));
}
public async Task VerifyComputeHashAsync(int size)
{
int fullCycles = size / 256;
int partial = size % 256;
// SUM(0..255) is 32640
const long CycleSum = 32640L;
// The formula for additive sum IS n*(n+1)/2, but size is a count and the first n is 0,
// which happens to turn it into (n-1) * n / 2, aka n * (n - 1) / 2.
long expectedSum = CycleSum * fullCycles + (partial * (partial - 1) / 2);
using (PositionValueStream stream = new PositionValueStream(size))
using (HashAlgorithm hash = new SummingTestHashAlgorithm())
{
byte[] result = await hash.ComputeHashAsync(stream);
byte[] expected = BitConverter.GetBytes(expectedSum);
Assert.Equal(expected, result);
}
}
