private static void PostProcess(ref UInt64 h, UInt64[] initValues, ulong dataCount, byte[] remainder)
{
if (dataCount >= 32)
{
h = initValues[0].RotateLeft(1) +
initValues[1].RotateLeft(7) +
initValues[2].RotateLeft(12) +
initValues[3].RotateLeft(18);
for (var x = 0; x < initValues.Length; ++x)
{
initValues[x] *= _primes64[1];
initValues[x] = initValues[x].RotateLeft(31);
initValues[x] *= _primes64[0];
h ^= initValues[x];
h = (h * _primes64[0]) + _primes64[3];
}
}
h += (UInt64)dataCount;
if (remainder != null)
{
// In 8-byte chunks, process all full chunks
for (int x = 0; x < remainder.Length / 8; ++x)
{
h ^= (BitConverter.ToUInt64(remainder, x * 8) * _primes64[1]).RotateLeft(31) * _primes64[0];
h = (h.RotateLeft(27) * _primes64[0]) + _primes64[3];
}
// Process a 4-byte chunk if it exists
if ((remainder.Length % 8) >= 4)
{
h ^= ((UInt64)BitConverter.ToUInt32(remainder, remainder.Length - (remainder.Length % 8))) * _primes64[0];
h = (h.RotateLeft(23) * _primes64[1]) + _primes64[2];
}
// Process last 4 bytes in 1-byte chunks (only runs if data.Length % 4 != 0)
for (int x = remainder.Length - (remainder.Length % 4); x < remainder.Length; ++x)
{
h ^= (UInt64)remainder[x] * _primes64[4];
h = h.RotateLeft(11) * _primes64[0];
}
}
h ^= h >> 33;
h *= _primes64[1];
h ^= h >> 29;
h *= _primes64[2];
h ^= h >> 32;
}
public void RotateLeftTest()
{
UInt64 actual = 3421843292831082394UL;
UInt64 expected = 17856004537878215074UL;
Assert.AreEqual(expected, actual.RotateLeft(4));
}
