public void ChecksumFor255CharsAStringIsCorrect(Crc16CcittInitialValue initialValue, ushort expected)
{
var s = new string('A', 256);
var input = s.ToCharArray().Select(c => (byte)c).ToArray();
testChecksum(input, initialValue, expected);
}
private static void testChecksum(byte[] input, Crc16CcittInitialValue initialValue, ushort expected)
{
var checksum = new Crc16CcittChecksum(initialValue) as IChecksum;
var crc = checksum.Calculate(input);
var actual = BitConverter.ToUInt16(crc, 0);
Assert.That(actual, Is.EqualTo(expected), string.Format("expected 0x{0:X} but was 0x{1:X}", expected, actual));
}
public Crc16CcittChecksum(Crc16CcittInitialValue initialValue)
{
this.m_InitialValue = (ushort)initialValue;
for (int i = 0; i < table.Length; ++i)
{
ushort temp = 0;
var a = (ushort)(i << 8);
for (int j = 0; j < 8; ++j)
{
if (((temp ^ a) & 0x8000) != 0)
{
temp = (ushort)((temp << 1) ^ poly);
}
else
{
temp <<= 1;
}
a <<= 1;
}
table[i] = temp;
}
}
public void ChecksumForReferenceStringIsCorrect(Crc16CcittInitialValue initialValue, ushort expected)
{
var input = "123456789".ToCharArray().Select(c => (byte)c).ToArray();
testChecksum(input, initialValue, expected);
}
public void ChecksumForCharAArratIsCorrect(Crc16CcittInitialValue initialValue, ushort expected)
{
byte[] input = new byte[] { (byte)'A' };
testChecksum(input, initialValue, expected);
}
