| 1 | /** |
| 2 | * Copyright (c) Meta Platforms, Inc. and affiliates. |
| 3 | * |
| 4 | * This source code is licensed under the MIT license found in the |
| 5 | * LICENSE file in the root directory of this source tree. |
| 6 | * |
| 7 | * @flow |
| 8 | */ |
| 9 | |
| 10 | // A pure JS implementation of a string hashing function. We do not use it for |
| 11 | // security or obfuscation purposes, only to create compact hashes. So we |
| 12 | // prioritize speed over collision avoidance. For example, we use this to hash |
| 13 | // the component key path used by useActionState for MPA-style submissions. |
| 14 | // |
| 15 | // In environments where built-in hashing functions are available, we prefer |
| 16 | // those instead. Like Node's crypto module, or Bun.hash. Unfortunately this |
| 17 | // does not include the web standard crypto API because those methods are all |
| 18 | // async. For our purposes, we need it to be sync because the cost of context |
| 19 | // switching is too high to be worth it. |
| 20 | // |
| 21 | // The most popular hashing algorithm that meets these requirements in the JS |
| 22 | // ecosystem is MurmurHash3, and almost all implementations I could find used |
| 23 | // some version of the implementation by Gary Court inlined below. |
| 24 | |
| 25 | export function createFastHashJS(key: string): number { |
| 26 | return murmurhash3_32_gc(key, 0); |
| 27 | } |
| 28 | |
| 29 | /* eslint-disable prefer-const, no-fallthrough */ |
| 30 | |
| 31 | /** |
| 32 | * @license |
| 33 | * |
| 34 | * JS Implementation of MurmurHash3 (r136) (as of May 20, 2011) |
| 35 | * |
| 36 | * Copyright (c) 2011 Gary Court |
| 37 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
| 38 | * of this software and associated documentation files (the "Software"), to deal |
| 39 | * in the Software without restriction, including without limitation the rights |
| 40 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| 41 | * copies of the Software, and to permit persons to whom the Software is |
| 42 | * furnished to do so, subject to the following conditions: |
| 43 | * |
| 44 | * The above copyright notice and this permission notice shall be included in |
| 45 | * all copies or substantial portions of the Software. |
| 46 | * |
| 47 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| 48 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| 49 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| 50 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| 51 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| 52 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE |
| 53 | * SOFTWARE. |
| 54 | */ |
| 55 | |
| 56 | function murmurhash3_32_gc(key: string, seed: number): number { |
| 57 | let remainder, bytes, h1, h1b, c1, c2, k1, i; |
| 58 | |
| 59 | remainder = key.length & 3; // key.length % 4 |
| 60 | bytes = key.length - remainder; |
| 61 | h1 = seed; |
| 62 | c1 = 0xcc9e2d51; |
| 63 | c2 = 0x1b873593; |
| 64 | i = 0; |
| 65 | |
| 66 | while (i < bytes) { |
| 67 | k1 = |
| 68 | (key.charCodeAt(i) & 0xff) | |
| 69 | ((key.charCodeAt(++i) & 0xff) << 8) | |
| 70 | ((key.charCodeAt(++i) & 0xff) << 16) | |
| 71 | ((key.charCodeAt(++i) & 0xff) << 24); |
| 72 | ++i; |
| 73 | |
| 74 | k1 = |
| 75 | ((k1 & 0xffff) * c1 + ((((k1 >>> 16) * c1) & 0xffff) << 16)) & 0xffffffff; |
| 76 | k1 = (k1 << 15) | (k1 >>> 17); |
| 77 | k1 = |
| 78 | ((k1 & 0xffff) * c2 + ((((k1 >>> 16) * c2) & 0xffff) << 16)) & 0xffffffff; |
| 79 | |
| 80 | h1 ^= k1; |
| 81 | h1 = (h1 << 13) | (h1 >>> 19); |
| 82 | h1b = |
| 83 | ((h1 & 0xffff) * 5 + ((((h1 >>> 16) * 5) & 0xffff) << 16)) & 0xffffffff; |
| 84 | h1 = (h1b & 0xffff) + 0x6b64 + ((((h1b >>> 16) + 0xe654) & 0xffff) << 16); |
| 85 | } |
| 86 | |
| 87 | k1 = 0; |
| 88 | |
| 89 | switch (remainder) { |
| 90 | case 3: |
| 91 | k1 ^= (key.charCodeAt(i + 2) & 0xff) << 16; |
| 92 | case 2: |
| 93 | k1 ^= (key.charCodeAt(i + 1) & 0xff) << 8; |
| 94 | case 1: |
| 95 | k1 ^= key.charCodeAt(i) & 0xff; |
| 96 | |
| 97 | k1 = |
| 98 | ((k1 & 0xffff) * c1 + ((((k1 >>> 16) * c1) & 0xffff) << 16)) & |
| 99 | 0xffffffff; |
| 100 | k1 = (k1 << 15) | (k1 >>> 17); |
| 101 | k1 = |
| 102 | ((k1 & 0xffff) * c2 + ((((k1 >>> 16) * c2) & 0xffff) << 16)) & |
| 103 | 0xffffffff; |
| 104 | h1 ^= k1; |
| 105 | } |
| 106 | |
| 107 | h1 ^= key.length; |
| 108 | |
| 109 | h1 ^= h1 >>> 16; |
| 110 | h1 = |
| 111 | ((h1 & 0xffff) * 0x85ebca6b + |
| 112 | ((((h1 >>> 16) * 0x85ebca6b) & 0xffff) << 16)) & |
| 113 | 0xffffffff; |
| 114 | h1 ^= h1 >>> 13; |
| 115 | h1 = |
| 116 | ((h1 & 0xffff) * 0xc2b2ae35 + |
| 117 | ((((h1 >>> 16) * 0xc2b2ae35) & 0xffff) << 16)) & |
| 118 | 0xffffffff; |
| 119 | h1 ^= h1 >>> 16; |
| 120 | |
| 121 | return h1 >>> 0; |
| 122 | } |