public unsafe static void HashRandomBytesFor()
{
var rd = new Random(Guid.NewGuid().GetHashCode());
ulong hash1 = 0;
for (int n = 1; n <= 8; n++)
{
byte[] bytes = new byte[n];
for (int i = 0; i < bytes.Length; i++)
{
bytes[i] = (byte)rd.Next(0, byte.MaxValue);
}
long costA = 0;
var w = Stopwatch.StartNew();
fixed(byte * @in = &bytes[0])
{
if (n == 1)
{
for (int i = 0; i < 100000000; i++)
{
//hash1 = FastHash.Hash(bytes);
//hash1 = XXHash64.HashUnroll(@in,n,0);
hash1 = XXHash64.Hash1(@in, 0);
}
costA = w.ElapsedMilliseconds;
}
if (n == 2)
{
for (int i = 0; i < 100000000; i++)
{
hash1 = XXHash64.Hash2(@in, 0);
}
costA = w.ElapsedMilliseconds;
}
if (n == 3)
{
for (int i = 0; i < 100000000; i++)
{
hash1 = XXHash64.Hash3(@in, 0);
}
costA = w.ElapsedMilliseconds;
}
if (n == 4)
{
for (int i = 0; i < 100000000; i++)
{
hash1 = XXHash64.Hash4(@in, 0);
}
costA = w.ElapsedMilliseconds;
}
if (n == 5)
{
for (int i = 0; i < 100000000; i++)
{
hash1 = XXHash64.Hash5(@in, 0);
}
costA = w.ElapsedMilliseconds;
}
if (n == 6)
{
for (int i = 0; i < 100000000; i++)
{
hash1 = XXHash64.Hash6(@in, 0);
}
costA = w.ElapsedMilliseconds;
}
if (n == 7)
{
for (int i = 0; i < 100000000; i++)
{
hash1 = XXHash64.Hash7(@in, 0);
}
costA = w.ElapsedMilliseconds;
}
if (n == 8)
{
for (int i = 0; i < 100000000; i++)
{
hash1 = XXHash64.Hash8(@in, 0);
}
costA = w.ElapsedMilliseconds;
}
w = Stopwatch.StartNew();
for (int i = 0; i < 100000000; i++)
{
hash1 = XXHash64.Hash(@in, n, 0);
}
}
w.Stop();
long costB = w.ElapsedMilliseconds;
Console.WriteLine($"Length:{n.ToString().PadRight(3,' ')} " +
$"FastHash Cost:{costA.ToString().PadRight(5, ' ')} " +
$"XXHash64 Cost:{costB.ToString().PadRight(5, ' ')} " +
$"Times:{((float)costB/costA).ToString("f3").PadRight(5,' ')}");
}
//rd = new Random(Guid.NewGuid().GetHashCode());
//for (int n = 1; n <= 32; n++)
//{
// byte[] bytes = new byte[n];
// for (int i = 0; i < bytes.Length; i++)
// bytes[i] = (byte)rd.Next(0, byte.MaxValue);
// Stopwatch w = Stopwatch.StartNew();
// for (int i = 0; i < 100000000; i++)
// {
// hash1 = XXHash64.Hash(bytes);
// }
// w.Stop();
// Console.WriteLine($"length:{n} XXHash64 cost:{w.ElapsedMilliseconds}");
//}
}
