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| 1 | +using System; |
| 2 | +using System.Text; |
| 3 | +using System.Runtime.CompilerServices; |
| 4 | + |
| 5 | +namespace Unity.Netcode |
| 6 | +{ |
| 7 | + internal static class XXHash |
| 8 | + { |
| 9 | + [MethodImpl(MethodImplOptions.AggressiveInlining)] |
| 10 | + public static unsafe uint Hash32(byte* input, int length, uint seed = 0) |
| 11 | + { |
| 12 | + unchecked |
| 13 | + { |
| 14 | + const uint prime1 = 2654435761u; |
| 15 | + const uint prime2 = 2246822519u; |
| 16 | + const uint prime3 = 3266489917u; |
| 17 | + const uint prime4 = 0668265263u; |
| 18 | + const uint prime5 = 0374761393u; |
| 19 | + |
| 20 | + uint hash = seed + prime5; |
| 21 | + |
| 22 | + if (length >= 16) |
| 23 | + { |
| 24 | + uint val0 = seed + prime1 + prime2; |
| 25 | + uint val1 = seed + prime2; |
| 26 | + uint val2 = seed + 0; |
| 27 | + uint val3 = seed - prime1; |
| 28 | + |
| 29 | + int count = length >> 4; |
| 30 | + for (int i = 0; i < count; i++) |
| 31 | + { |
| 32 | + var pos0 = *(uint*)(input + 0); |
| 33 | + var pos1 = *(uint*)(input + 4); |
| 34 | + var pos2 = *(uint*)(input + 8); |
| 35 | + var pos3 = *(uint*)(input + 12); |
| 36 | + |
| 37 | + val0 += pos0 * prime2; |
| 38 | + val0 = (val0 << 13) | (val0 >> (32 - 13)); |
| 39 | + val0 *= prime1; |
| 40 | + |
| 41 | + val1 += pos1 * prime2; |
| 42 | + val1 = (val1 << 13) | (val1 >> (32 - 13)); |
| 43 | + val1 *= prime1; |
| 44 | + |
| 45 | + val2 += pos2 * prime2; |
| 46 | + val2 = (val2 << 13) | (val2 >> (32 - 13)); |
| 47 | + val2 *= prime1; |
| 48 | + |
| 49 | + val3 += pos3 * prime2; |
| 50 | + val3 = (val3 << 13) | (val3 >> (32 - 13)); |
| 51 | + val3 *= prime1; |
| 52 | + |
| 53 | + input += 16; |
| 54 | + } |
| 55 | + |
| 56 | + hash = ((val0 << 01) | (val0 >> (32 - 01))) + |
| 57 | + ((val1 << 07) | (val1 >> (32 - 07))) + |
| 58 | + ((val2 << 12) | (val2 >> (32 - 12))) + |
| 59 | + ((val3 << 18) | (val3 >> (32 - 18))); |
| 60 | + } |
| 61 | + |
| 62 | + hash += (uint)length; |
| 63 | + |
| 64 | + length &= 15; |
| 65 | + while (length >= 4) |
| 66 | + { |
| 67 | + hash += *(uint*)input * prime3; |
| 68 | + hash = ((hash << 17) | (hash >> (32 - 17))) * prime4; |
| 69 | + input += 4; |
| 70 | + length -= 4; |
| 71 | + } |
| 72 | + while (length > 0) |
| 73 | + { |
| 74 | + hash += *input * prime5; |
| 75 | + hash = ((hash << 11) | (hash >> (32 - 11))) * prime1; |
| 76 | + ++input; |
| 77 | + --length; |
| 78 | + } |
| 79 | + |
| 80 | + hash ^= hash >> 15; |
| 81 | + hash *= prime2; |
| 82 | + hash ^= hash >> 13; |
| 83 | + hash *= prime3; |
| 84 | + hash ^= hash >> 16; |
| 85 | + |
| 86 | + return hash; |
| 87 | + } |
| 88 | + } |
| 89 | + |
| 90 | + [MethodImpl(MethodImplOptions.AggressiveInlining)] |
| 91 | + public static unsafe ulong Hash64(byte* input, int length, uint seed = 0) |
| 92 | + { |
| 93 | + unchecked |
| 94 | + { |
| 95 | + const ulong prime1 = 11400714785074694791ul; |
| 96 | + const ulong prime2 = 14029467366897019727ul; |
| 97 | + const ulong prime3 = 01609587929392839161ul; |
| 98 | + const ulong prime4 = 09650029242287828579ul; |
| 99 | + const ulong prime5 = 02870177450012600261ul; |
| 100 | + |
| 101 | + ulong hash = seed + prime5; |
| 102 | + |
| 103 | + if (length >= 32) |
| 104 | + { |
| 105 | + ulong val0 = seed + prime1 + prime2; |
| 106 | + ulong val1 = seed + prime2; |
| 107 | + ulong val2 = seed + 0; |
| 108 | + ulong val3 = seed - prime1; |
| 109 | + |
| 110 | + int count = length >> 5; |
| 111 | + for (int i = 0; i < count; i++) |
| 112 | + { |
| 113 | + var pos0 = *(ulong*)(input + 0); |
| 114 | + var pos1 = *(ulong*)(input + 8); |
| 115 | + var pos2 = *(ulong*)(input + 16); |
| 116 | + var pos3 = *(ulong*)(input + 24); |
| 117 | + |
| 118 | + val0 += pos0 * prime2; |
| 119 | + val0 = (val0 << 31) | (val0 >> (64 - 31)); |
| 120 | + val0 *= prime1; |
| 121 | + |
| 122 | + val1 += pos1 * prime2; |
| 123 | + val1 = (val1 << 31) | (val1 >> (64 - 31)); |
| 124 | + val1 *= prime1; |
| 125 | + |
| 126 | + val2 += pos2 * prime2; |
| 127 | + val2 = (val2 << 31) | (val2 >> (64 - 31)); |
| 128 | + val2 *= prime1; |
| 129 | + |
| 130 | + val3 += pos3 * prime2; |
| 131 | + val3 = (val3 << 31) | (val3 >> (64 - 31)); |
| 132 | + val3 *= prime1; |
| 133 | + |
| 134 | + input += 32; |
| 135 | + } |
| 136 | + |
| 137 | + hash = ((val0 << 01) | (val0 >> (64 - 01))) + |
| 138 | + ((val1 << 07) | (val1 >> (64 - 07))) + |
| 139 | + ((val2 << 12) | (val2 >> (64 - 12))) + |
| 140 | + ((val3 << 18) | (val3 >> (64 - 18))); |
| 141 | + |
| 142 | + val0 *= prime2; |
| 143 | + val0 = (val0 << 31) | (val0 >> (64 - 31)); |
| 144 | + val0 *= prime1; |
| 145 | + hash ^= val0; |
| 146 | + hash = hash * prime1 + prime4; |
| 147 | + |
| 148 | + val1 *= prime2; |
| 149 | + val1 = (val1 << 31) | (val1 >> (64 - 31)); |
| 150 | + val1 *= prime1; |
| 151 | + hash ^= val1; |
| 152 | + hash = hash * prime1 + prime4; |
| 153 | + |
| 154 | + val2 *= prime2; |
| 155 | + val2 = (val2 << 31) | (val2 >> (64 - 31)); |
| 156 | + val2 *= prime1; |
| 157 | + hash ^= val2; |
| 158 | + hash = hash * prime1 + prime4; |
| 159 | + |
| 160 | + val3 *= prime2; |
| 161 | + val3 = (val3 << 31) | (val3 >> (64 - 31)); |
| 162 | + val3 *= prime1; |
| 163 | + hash ^= val3; |
| 164 | + hash = hash * prime1 + prime4; |
| 165 | + } |
| 166 | + |
| 167 | + hash += (ulong)length; |
| 168 | + |
| 169 | + length &= 31; |
| 170 | + while (length >= 8) |
| 171 | + { |
| 172 | + ulong lane = *(ulong*)input * prime2; |
| 173 | + lane = ((lane << 31) | (lane >> (64 - 31))) * prime1; |
| 174 | + hash ^= lane; |
| 175 | + hash = ((hash << 27) | (hash >> (64 - 27))) * prime1 + prime4; |
| 176 | + input += 8; |
| 177 | + length -= 8; |
| 178 | + } |
| 179 | + if (length >= 4) |
| 180 | + { |
| 181 | + hash ^= *(uint*)input * prime1; |
| 182 | + hash = ((hash << 23) | (hash >> (64 - 23))) * prime2 + prime3; |
| 183 | + input += 4; |
| 184 | + length -= 4; |
| 185 | + } |
| 186 | + while (length > 0) |
| 187 | + { |
| 188 | + hash ^= *input * prime5; |
| 189 | + hash = ((hash << 11) | (hash >> (64 - 11))) * prime1; |
| 190 | + ++input; |
| 191 | + --length; |
| 192 | + } |
| 193 | + |
| 194 | + hash ^= hash >> 33; |
| 195 | + hash *= prime2; |
| 196 | + hash ^= hash >> 29; |
| 197 | + hash *= prime3; |
| 198 | + hash ^= hash >> 32; |
| 199 | + |
| 200 | + return hash; |
| 201 | + } |
| 202 | + } |
| 203 | + |
| 204 | + [MethodImpl(MethodImplOptions.AggressiveInlining)] |
| 205 | + public static uint Hash32(this byte[] buffer) |
| 206 | + { |
| 207 | + int length = buffer.Length; |
| 208 | + unsafe |
| 209 | + { |
| 210 | + fixed (byte* pointer = buffer) |
| 211 | + { |
| 212 | + return Hash32(pointer, length); |
| 213 | + } |
| 214 | + } |
| 215 | + } |
| 216 | + |
| 217 | + [MethodImpl(MethodImplOptions.AggressiveInlining)] |
| 218 | + public static uint Hash32(this string text) => Hash32(Encoding.UTF8.GetBytes(text)); |
| 219 | + |
| 220 | + [MethodImpl(MethodImplOptions.AggressiveInlining)] |
| 221 | + public static uint Hash32(this Type type) => Hash32(type.FullName); |
| 222 | + |
| 223 | + [MethodImpl(MethodImplOptions.AggressiveInlining)] |
| 224 | + public static uint Hash32<T>() => Hash32(typeof(T)); |
| 225 | + |
| 226 | + [MethodImpl(MethodImplOptions.AggressiveInlining)] |
| 227 | + public static ulong Hash64(this byte[] buffer) |
| 228 | + { |
| 229 | + int length = buffer.Length; |
| 230 | + unsafe |
| 231 | + { |
| 232 | + fixed (byte* pointer = buffer) |
| 233 | + { |
| 234 | + return Hash64(pointer, length); |
| 235 | + } |
| 236 | + } |
| 237 | + } |
| 238 | + |
| 239 | + [MethodImpl(MethodImplOptions.AggressiveInlining)] |
| 240 | + public static ulong Hash64(this string text) => Hash64(Encoding.UTF8.GetBytes(text)); |
| 241 | + |
| 242 | + [MethodImpl(MethodImplOptions.AggressiveInlining)] |
| 243 | + public static ulong Hash64(this Type type) => Hash64(type.FullName); |
| 244 | + |
| 245 | + [MethodImpl(MethodImplOptions.AggressiveInlining)] |
| 246 | + public static ulong Hash64<T>() => Hash64(typeof(T)); |
| 247 | + } |
| 248 | +} |
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