From efbc2ffe6a1ee5ec38a4396305561d6515d0943e Mon Sep 17 00:00:00 2001 From: littleblack111 Date: Fri, 30 Aug 2024 17:21:18 +0800 Subject: node fixes, updates --- node_modules/webpack/lib/util/numberHash.js | 95 +++++++++++++++++++++++++++++ 1 file changed, 95 insertions(+) create mode 100644 node_modules/webpack/lib/util/numberHash.js (limited to 'node_modules/webpack/lib/util/numberHash.js') diff --git a/node_modules/webpack/lib/util/numberHash.js b/node_modules/webpack/lib/util/numberHash.js new file mode 100644 index 00000000..950d14bf --- /dev/null +++ b/node_modules/webpack/lib/util/numberHash.js @@ -0,0 +1,95 @@ +/* + MIT License http://www.opensource.org/licenses/mit-license.php + Author Tobias Koppers @sokra +*/ + +"use strict"; + +/** + * Threshold for switching from 32-bit to 64-bit hashing. This is selected to ensure that the bias towards lower modulo results when using 32-bit hashing is <0.5%. + * @type {number} + */ +const FNV_64_THRESHOLD = 1 << 24; + +/** + * The FNV-1a offset basis for 32-bit hash values. + * @type {number} + */ +const FNV_OFFSET_32 = 2166136261; +/** + * The FNV-1a prime for 32-bit hash values. + * @type {number} + */ +const FNV_PRIME_32 = 16777619; +/** + * The mask for a positive 32-bit signed integer. + * @type {number} + */ +const MASK_31 = 0x7fffffff; + +/** + * The FNV-1a offset basis for 64-bit hash values. + * @type {bigint} + */ +const FNV_OFFSET_64 = BigInt("0xCBF29CE484222325"); +/** + * The FNV-1a prime for 64-bit hash values. + * @type {bigint} + */ +const FNV_PRIME_64 = BigInt("0x100000001B3"); + +/** + * Computes a 32-bit FNV-1a hash value for the given string. + * See https://en.wikipedia.org/wiki/Fowler%E2%80%93Noll%E2%80%93Vo_hash_function + * @param {string} str The input string to hash + * @returns {number} - The computed hash value. + */ +function fnv1a32(str) { + let hash = FNV_OFFSET_32; + for (let i = 0, len = str.length; i < len; i++) { + hash ^= str.charCodeAt(i); + // Use Math.imul to do c-style 32-bit multiplication and keep only the 32 least significant bits + hash = Math.imul(hash, FNV_PRIME_32); + } + // Force the result to be positive + return hash & MASK_31; +} + +/** + * Computes a 64-bit FNV-1a hash value for the given string. + * See https://en.wikipedia.org/wiki/Fowler%E2%80%93Noll%E2%80%93Vo_hash_function + * @param {string} str The input string to hash + * @returns {bigint} - The computed hash value. + */ +function fnv1a64(str) { + let hash = FNV_OFFSET_64; + for (let i = 0, len = str.length; i < len; i++) { + hash ^= BigInt(str.charCodeAt(i)); + hash = BigInt.asUintN(64, hash * FNV_PRIME_64); + } + return hash; +} + +/** + * Computes a hash value for the given string and range. This hashing algorithm is a modified + * version of the [FNV-1a algorithm](https://en.wikipedia.org/wiki/Fowler%E2%80%93Noll%E2%80%93Vo_hash_function). + * It is optimized for speed and does **not** generate a cryptographic hash value. + * + * We use `numberHash` in `lib/ids/IdHelpers.js` to generate hash values for the module identifier. The generated + * hash is used as a prefix for the module id's to avoid collisions with other modules. + * @param {string} str The input string to hash. + * @param {number} range The range of the hash value (0 to range-1). + * @returns {number} - The computed hash value. + * @example + * ```js + * const numberHash = require("webpack/lib/util/numberHash"); + * numberHash("hello", 1000); // 73 + * numberHash("hello world"); // 72 + * ``` + */ +module.exports = (str, range) => { + if (range < FNV_64_THRESHOLD) { + return fnv1a32(str) % range; + } + return Number(fnv1a64(str) % BigInt(range)); +}; -- cgit v1.2.3