@qiniu/miku-delivery-mp-ks/dist/utils/murmur3-32/index.js

Kuaishou Mini Program SDK for Miku Delivery

/**
 * @file MurmurHash3 x86 32-bit implemented in JavaScript.
 * @desc Copy from https://github.com/LinusU/murmur-32/blob/master/index.js for unit-testing (jest problematic with ES Module in node_modules)
 */
import encodeUtf8 from './encode-utf8';
import fmix from './fmix';
const C = new Uint32Array([
    0xcc9e2d51,
    0x1b873593
]);
function rotl(m, n) {
    return (m << n) | (m >>> (32 - n));
}
function body(key, hash) {
    const blocks = (key.byteLength / 4) | 0;
    const view32 = new Uint32Array(key, 0, blocks);
    for (let i = 0; i < blocks; i++) {
        view32[i] = Math.imul(view32[i], C[0]);
        view32[i] = rotl(view32[i], 15);
        view32[i] = Math.imul(view32[i], C[1]);
        hash[0] = (hash[0] ^ view32[i]);
        hash[0] = rotl(hash[0], 13);
        hash[0] = Math.imul(hash[0], 5) + 0xe6546b64;
    }
}
function tail(key, hash) {
    const blocks = (key.byteLength / 4) | 0;
    const reminder = (key.byteLength % 4);
    let k = 0;
    const tail = new Uint8Array(key, blocks * 4, reminder);
    switch (reminder) {
        case 3:
            k = (k ^ (tail[2] << 16));
        // fallthrough
        case 2:
            k = (k ^ (tail[1] << 8));
        // fallthrough
        case 1:
            k = (k ^ (tail[0] << 0));
            k = Math.imul(k, C[0]);
            k = rotl(k, 15);
            k = Math.imul(k, C[1]);
            hash[0] = (hash[0] ^ k);
    }
}
function finalize(key, hash) {
    hash[0] = (hash[0] ^ key.byteLength);
    hash[0] = fmix(hash[0]);
}
export default function murmur(key, seed) {
    seed = (seed ? (seed | 0) : 0);
    if (typeof key === 'string') {
        key = encodeUtf8(key);
    }
    if (!(key instanceof ArrayBuffer)) {
        throw new TypeError('Expected key to be ArrayBuffer or string');
    }
    const hash = new Uint32Array([seed]);
    body(key, hash);
    tail(key, hash);
    finalize(key, hash);
    return hash.buffer;
}