/// <inheritdoc />
protected override void HashCore(byte[] array, int ibStart, int cbSize)
{
unsafe
{
fixed(byte *arrayPtr = array)
{
while (cbSize > 0)
{
int bytesToCopy = (int)Math.Min(cbSize, BlockSize - _currentOffset);
if (bytesToCopy < BlockSize)
{
Buffer.BlockCopy(array, ibStart, _buffer, (int)_currentOffset, bytesToCopy);
_currentOffset += (uint)bytesToCopy;
}
else
{
AddBlockHash(MurmurHash3.Create(arrayPtr + ibStart, BlockSize, AlgorithmSeed));
_currentOffset = 0;
}
ibStart += bytesToCopy;
cbSize -= bytesToCopy;
}
}
}
}
/// <inheritdoc />
protected override byte[] HashFinal()
{
// Flush out buffer
if (_currentOffset != 0)
{
unsafe
{
fixed(byte *arrayPtr = _buffer)
{
AddBlockHash(MurmurHash3.Create(arrayPtr, _currentOffset, AlgorithmSeed));
}
}
}
// if there are no blocks add an empty block
if (_currentBlockOffset == 0)
{
return(EmptyHashBytes);
}
else if (_currentBlockOffset > 8)
{
CombineBlockHashes();
}
for (int i = 0; i < 8; i++)
{
finalHash[i] = _blockHashes[i];
}
return(finalHash);
}
private void AddBlockHash(MurmurHash3 hash)
{
hash.GetHashBytes(_blockHashes, _currentBlockOffset);
_currentBlockOffset += 8;
if (_currentBlockOffset == BlockSize)
{
CombineBlockHashes();
}
}
private void CombineBlockHashes()
{
unsafe
{
fixed(byte *arrayPtr = _blockHashes)
{
MurmurHash3 combinedHash = MurmurHash3.Create(arrayPtr, _currentBlockOffset, AlgorithmSeed);
combinedHash.GetHashBytes(_blockHashes, 0);
_currentBlockOffset = 8;
}
}
}
