public static int HammingDistance(BitArray hash1, BitArray hash2)
{
if (hash1.Length != hash2.Length)
{
throw new ArgumentException("Can't compare hashes with different length");
}
var d = 0;
var bits = hash1.Xor(hash2);
for (var i = 0; i < bits.Length; i++)
{
d += bits[i] ? 1 : 0;
}
return(d);
}
public static byte[] ToHashBytes(this BitArray bits)
{
var length = (bits.Length - 1) / 8 + 1;
byte[] result = new byte[length];
for (var i = 0; i < result.Length; i++)
{
var index = i * 8;
result[i] = (byte)(
(bits[index + 0] ? 0b10000000 : 0b0) |
(bits[index + 1] ? 0b1000000 : 0b0) |
(bits[index + 2] ? 0b100000 : 0b0) |
(bits[index + 3] ? 0b10000 : 0b0) |
(bits[index + 4] ? 0b1000 : 0b0) |
(bits[index + 5] ? 0b100 : 0b0) |
(bits[index + 6] ? 0b10 : 0b0) |
(bits[index + 7] ? 0b1 : 0b0));
}
return(result);
}
public static string ToHashString(this BitArray bits)
{
var length = (bits.Length - 1) / 8 + 1;
var result = new System.Text.StringBuilder(length * 2);
for (var i = 0; i < length; i++)
{
var index = i * 8;
result.AppendFormat("{0:x2}", (byte)(
(bits[index + 0] ? 0b10000000 : 0b0) |
(bits[index + 1] ? 0b1000000 : 0b0) |
(bits[index + 2] ? 0b100000 : 0b0) |
(bits[index + 3] ? 0b10000 : 0b0) |
(bits[index + 4] ? 0b1000 : 0b0) |
(bits[index + 5] ? 0b100 : 0b0) |
(bits[index + 6] ? 0b10 : 0b0) |
(bits[index + 7] ? 0b1 : 0b0)));
}
return(result.ToString());
}
