60 lines
1.7 KiB
JavaScript
60 lines
1.7 KiB
JavaScript
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'use strict';
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Object.defineProperty(exports, '__esModule', { value: true });
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/* eslint-disable */
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// Inspired by https://github.com/garycourt/murmurhash-js
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// Ported from https://github.com/aappleby/smhasher/blob/61a0530f28277f2e850bfc39600ce61d02b518de/src/MurmurHash2.cpp#L37-L86
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function murmur2(str) {
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// 'm' and 'r' are mixing constants generated offline.
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// They're not really 'magic', they just happen to work well.
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// const m = 0x5bd1e995;
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// const r = 24;
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// Initialize the hash
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var h = 0; // Mix 4 bytes at a time into the hash
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var k,
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i = 0,
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len = str.length;
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for (; len >= 4; ++i, len -= 4) {
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k = str.charCodeAt(i) & 0xff | (str.charCodeAt(++i) & 0xff) << 8 | (str.charCodeAt(++i) & 0xff) << 16 | (str.charCodeAt(++i) & 0xff) << 24;
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k =
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/* Math.imul(k, m): */
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(k & 0xffff) * 0x5bd1e995 + ((k >>> 16) * 0xe995 << 16);
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k ^=
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/* k >>> r: */
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k >>> 24;
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h =
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/* Math.imul(k, m): */
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(k & 0xffff) * 0x5bd1e995 + ((k >>> 16) * 0xe995 << 16) ^
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/* Math.imul(h, m): */
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(h & 0xffff) * 0x5bd1e995 + ((h >>> 16) * 0xe995 << 16);
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} // Handle the last few bytes of the input array
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switch (len) {
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case 3:
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h ^= (str.charCodeAt(i + 2) & 0xff) << 16;
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case 2:
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h ^= (str.charCodeAt(i + 1) & 0xff) << 8;
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case 1:
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h ^= str.charCodeAt(i) & 0xff;
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h =
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/* Math.imul(h, m): */
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(h & 0xffff) * 0x5bd1e995 + ((h >>> 16) * 0xe995 << 16);
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} // Do a few final mixes of the hash to ensure the last few
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// bytes are well-incorporated.
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h ^= h >>> 13;
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h =
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/* Math.imul(h, m): */
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(h & 0xffff) * 0x5bd1e995 + ((h >>> 16) * 0xe995 << 16);
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return ((h ^ h >>> 15) >>> 0).toString(36);
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}
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exports["default"] = murmur2;
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