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| 1 | +/* |
| 2 | + * The MIT License (MIT) |
| 3 | + * |
| 4 | + * Copyright (c) 2021 Denis Kuzmin <x-3F@outlook.com> github/3F |
| 5 | + * Copyright (c) sandbox contributors https://github.com/3F/sandbox/graphs/contributors |
| 6 | + * |
| 7 | + * Permission is hereby granted, free of charge, to any person obtaining a copy |
| 8 | + * of this software and associated documentation files (the "Software"), to deal |
| 9 | + * in the Software without restriction, including without limitation the rights |
| 10 | + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| 11 | + * copies of the Software, and to permit persons to whom the Software is |
| 12 | + * furnished to do so, subject to the following conditions: |
| 13 | + * |
| 14 | + * The above copyright notice and this permission notice shall be included in |
| 15 | + * all copies or substantial portions of the Software. |
| 16 | + * |
| 17 | + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| 18 | + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| 19 | + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| 20 | + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| 21 | + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| 22 | + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| 23 | + * THE SOFTWARE. |
| 24 | +*/ |
| 25 | + |
| 26 | +using net.r_eg.sandbox.algorithms; |
| 27 | + |
| 28 | +namespace net.r_eg.sandbox.Hash |
| 29 | +{ |
| 30 | + public static class FNV1a |
| 31 | + { |
| 32 | + private const ulong OFS64 = 0xcbf29ce484222325; |
| 33 | + private const ulong PRIME64 = 0x00000100000001B3; |
| 34 | + |
| 35 | + private const uint P128_B = 0x01000000, P128_D = 0x0000013B, P128_BD = 0xFFFEC5; |
| 36 | + |
| 37 | + public static ulong GetHash128LX4Cnh(string input, out ulong low) |
| 38 | + { |
| 39 | + ulong a = 0x6c62272e, b = 0x07bb0142, c = 0x62b82175, d = 0x6295c58d; |
| 40 | + |
| 41 | + ulong f = 0, fLm = 0; |
| 42 | + unchecked |
| 43 | + { |
| 44 | + for(int i = 0; i < input.Length; ++i) |
| 45 | + { |
| 46 | + d ^= input[i]; |
| 47 | + |
| 48 | + // Below is an optimized implementation (limited) of the LX4Cnh algorithm specially for Fnv1a128 |
| 49 | + // (c) Denis Kuzmin <x-3F@outlook.com> github/3F |
| 50 | + |
| 51 | + f = b * P128_B; |
| 52 | + |
| 53 | + ulong v = (uint)f; |
| 54 | + |
| 55 | + f = (f >> 32) + v; |
| 56 | + |
| 57 | + if(a > b) |
| 58 | + { |
| 59 | + f += (uint)((a - b) * P128_B); |
| 60 | + } |
| 61 | + else if(a < b) |
| 62 | + { |
| 63 | + f -= (uint)((b - a) * P128_B); |
| 64 | + } |
| 65 | + |
| 66 | + ulong fHigh = (f << 32) + (uint)v; |
| 67 | + ulong r2 = d * P128_D; |
| 68 | + |
| 69 | + v = (r2 >> 32) + (r2 & 0xFFF_FFFF_FFFF_FFFF); |
| 70 | + |
| 71 | + f = (r2 & 0xF000_0000_0000_0000) >> 32; |
| 72 | + |
| 73 | + if(c > d) |
| 74 | + { |
| 75 | + fLm = v; |
| 76 | + v += (c - d) * P128_D; |
| 77 | + if(fLm > v) f += 0x100000000; |
| 78 | + } |
| 79 | + else if(c < d) |
| 80 | + { |
| 81 | + fLm = v; |
| 82 | + v -= (d - c) * P128_D; |
| 83 | + if(fLm < v) f -= 0x100000000; |
| 84 | + } |
| 85 | + |
| 86 | + fLm = (((ulong)(uint)v) << 32) + (uint)r2; |
| 87 | + |
| 88 | + f = fHigh + fLm + f + (v >> 32); |
| 89 | + |
| 90 | + fHigh = (a << 32) + b; //fa |
| 91 | + v = (c << 32) + d; //fb |
| 92 | + |
| 93 | + if(fHigh < v) |
| 94 | + { |
| 95 | + f += (v - fHigh) * P128_BD; |
| 96 | + } |
| 97 | + else if(fHigh > v) |
| 98 | + { |
| 99 | + f -= (fHigh - v) * P128_BD; |
| 100 | + } |
| 101 | + |
| 102 | + a = f >> 32; |
| 103 | + b = (uint)f; |
| 104 | + c = fLm >> 32; |
| 105 | + d = (uint)fLm; |
| 106 | + } |
| 107 | + } |
| 108 | + |
| 109 | + low = fLm; |
| 110 | + return f; |
| 111 | + } |
| 112 | + |
| 113 | + public static ulong GetHash64(string input) |
| 114 | + { |
| 115 | + ulong hash = OFS64; |
| 116 | + |
| 117 | + unchecked |
| 118 | + { |
| 119 | + for(int i = 0; i < input.Length; ++i) |
| 120 | + { |
| 121 | + hash = (hash ^ input[i]) * PRIME64; |
| 122 | + } |
| 123 | + } |
| 124 | + |
| 125 | + return hash; |
| 126 | + } |
| 127 | + |
| 128 | + public static ulong GetHash128Call(string input, out ulong low) |
| 129 | + { |
| 130 | + uint a = 0x6c62272e, b = 0x07bb0142, c = 0x62b82175, d = 0x6295c58d; |
| 131 | + |
| 132 | + ulong f = 0; low = 0; |
| 133 | + unchecked |
| 134 | + { |
| 135 | + for(int i = 0; i < input.Length; ++i) |
| 136 | + { |
| 137 | + d ^= input[i]; |
| 138 | + |
| 139 | + f = LodgeX4CorrNoHigh.Multiply(a, b, c, d, 0, P128_B, 0, P128_D, out low); |
| 140 | + |
| 141 | + a = (uint)(f >> 32); |
| 142 | + b = (uint)f; |
| 143 | + c = (uint)(low >> 32); |
| 144 | + d = (uint)low; |
| 145 | + } |
| 146 | + } |
| 147 | + |
| 148 | + return f; |
| 149 | + } |
| 150 | + } |
| 151 | +} |
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