private static Value128 TypeHash(Type type, string entropy = "", Value128 seed = default)
{
var hash = Hashing.MurmurHash3(type.AssemblyQualifiedName ?? "?") ^
Hashing.MurmurHash3(entropy) ^
seed;
return(hash);
}
public static Value128 MurmurHash3(ulong key, Value128 seed = default)
{
const int len = 4;
var h1 = seed.v1;
var h2 = seed.v2;
//----------
// tail
{
ulong k1 = 0;
k1 = key;
k1 *= C1;
k1 = Rotl64(k1, 31);
k1 *= C2;
h1 ^= k1;
}
//----------
// finalization
h1 ^= len;
h2 ^= len;
h1 += h2;
h2 += h1;
h1 = Fmix64(h1);
h2 = Fmix64(h2);
h1 += h2;
h2 += h1;
var retval = new Value128();
retval.v1 = h1;
retval.v2 = h2;
return(retval);
}
public static Value128 MurmurHash3(StringBuilder key, Value128 seed = default)
{
var len = key.Length * 2; // chars are 16 bits
var blocks = key.Length / 8;
var h1 = seed.v1;
var h2 = seed.v2;
//----------
// body
for (var i = 0; i < blocks; i++)
{
// Get 128 bits from key
ulong k1 = key[i * 8];
k1 |= (ulong)key[i * 8 + 1] << 16;
k1 |= (ulong)key[i * 8 + 2] << 32;
k1 |= (ulong)key[i * 8 + 3] << 48;
ulong k2 = key[i * 8 + 4];
k2 |= (ulong)key[i * 8 + 5] << 16;
k2 |= (ulong)key[i * 8 + 6] << 32;
k2 |= (ulong)key[i * 8 + 7] << 48;
k1 *= C1;
k1 = Rotl64(k1, 31);
k1 *= C2;
h1 ^= k1;
h1 = Rotl64(h1, 27);
h1 += h2;
h1 = h1 * 5 + 0x52dce729;
k2 *= C2;
k2 = Rotl64(k2, 33);
k2 *= C1;
h2 ^= k2;
h2 = Rotl64(h2, 31);
h2 += h1;
h2 = h2 * 5 + 0x38495ab5;
}
//----------
// tail
{
ulong k1 = 0;
ulong k2 = 0;
var offset = blocks * 8;
switch (key.Length & 7) // len & 15
{
case 7:
k2 |= (ulong)key[offset + 6] << 32;
goto case 6;
case 6:
k2 |= (ulong)key[offset + 5] << 16;
goto case 5;
case 5:
k2 |= (ulong)key[offset + 4] << 0;
k2 *= C2;
k2 = Rotl64(k2, 33);
k2 *= C1;
h2 ^= k2;
goto case 4;
case 4:
k1 |= (ulong)key[offset + 3] << 48;
goto case 3;
case 3:
k1 |= (ulong)key[offset + 2] << 32;
goto case 2;
case 2:
k1 |= (ulong)key[offset + 1] << 16;
goto case 1;
case 1:
k1 |= (ulong)key[offset + 0] << 0;
k1 *= C1;
k1 = Rotl64(k1, 31);
k1 *= C2;
h1 ^= k1;
break;
}
}
//----------
// finalization
h1 ^= (ulong)len;
h2 ^= (ulong)len;
h1 += h2;
h2 += h1;
h1 = Fmix64(h1);
h2 = Fmix64(h2);
h1 += h2;
h2 += h1;
var retval = new Value128();
retval.v1 = h1;
retval.v2 = h2;
return(retval);
}
public static Value128 MurmurHash3(byte[] key, Value128 seed = default)
{
var len = key.Length;
var blocks = len / 16;
var h1 = seed.v1;
var h2 = seed.v2;
//----------
// body
for (var i = 0; i < blocks; i++)
{
// Get 128 bits from key
ulong k1 = key[i * 16];
k1 |= (ulong)key[i * 16 + 1] << 8;
k1 |= (ulong)key[i * 16 + 2] << 16;
k1 |= (ulong)key[i * 16 + 3] << 24;
k1 |= (ulong)key[i * 16 + 4] << 32;
k1 |= (ulong)key[i * 16 + 5] << 40;
k1 |= (ulong)key[i * 16 + 6] << 48;
k1 |= (ulong)key[i * 16 + 7] << 56;
ulong k2 = key[i * 16 + 8];
k2 |= (ulong)key[i * 16 + 9] << 8;
k2 |= (ulong)key[i * 16 + 10] << 16;
k2 |= (ulong)key[i * 16 + 11] << 24;
k2 |= (ulong)key[i * 16 + 12] << 32;
k2 |= (ulong)key[i * 16 + 13] << 40;
k2 |= (ulong)key[i * 16 + 14] << 48;
k2 |= (ulong)key[i * 16 + 15] << 56;
k1 *= C1;
k1 = Rotl64(k1, 31);
k1 *= C2;
h1 ^= k1;
h1 = Rotl64(h1, 27);
h1 += h2;
h1 = h1 * 5 + 0x52dce729;
k2 *= C2;
k2 = Rotl64(k2, 33);
k2 *= C1;
h2 ^= k2;
h2 = Rotl64(h2, 31);
h2 += h1;
h2 = h2 * 5 + 0x38495ab5;
}
//----------
// tail
{
ulong k1 = 0;
ulong k2 = 0;
var offset = blocks * 16;
switch (len & ((1u << 4) - 1)) // len & 15
{
case 15:
k2 |= (ulong)key[offset + 14] << 48;
goto case 14;
case 14:
k2 |= (ulong)key[offset + 13] << 40;
goto case 13;
case 13:
k2 |= (ulong)key[offset + 12] << 32;
goto case 12;
case 12:
k2 |= (ulong)key[offset + 11] << 24;
goto case 11;
case 11:
k2 |= (ulong)key[offset + 10] << 16;
goto case 10;
case 10:
k2 |= (ulong)key[offset + 9] << 8;
goto case 9;
case 9:
k2 ^= (ulong)key[8] << 0;
k2 *= C2;
k2 = Rotl64(k2, 33);
k2 *= C1;
h2 ^= k2;
goto case 8;
case 8:
k1 |= (ulong)key[offset + 7] << 56;
goto case 7;
case 7:
k1 |= (ulong)key[offset + 6] << 48;
goto case 6;
case 6:
k1 |= (ulong)key[offset + 5] << 40;
goto case 5;
case 5:
k1 |= (ulong)key[offset + 4] << 32;
goto case 4;
case 4:
k1 |= (ulong)key[offset + 3] << 24;
goto case 3;
case 3:
k1 |= (ulong)key[offset + 2] << 16;
goto case 2;
case 2:
k1 |= (ulong)key[offset + 1] << 8;
goto case 1;
case 1:
k1 ^= (ulong)key[0] << 0;
k1 *= C1;
k1 = Rotl64(k1, 31);
k1 *= C2;
h1 ^= k1;
break;
}
}
//----------
// finalization
h1 ^= (ulong)len;
h2 ^= (ulong)len;
h1 += h2;
h2 += h1;
h1 = Fmix64(h1);
h2 = Fmix64(h2);
h1 += h2;
h2 += h1;
var retval = new Value128();
retval.v1 = h1;
retval.v2 = h2;
return(retval);
}
