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2 |
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7 |
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8 |
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9 |
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10 | const FNV_PRIMES = {
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11 | 32: 16_777_619n,
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12 | 64: 1_099_511_628_211n,
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13 | 128: 309_485_009_821_345_068_724_781_371n,
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14 | 256: 374_144_419_156_711_147_060_143_317_175_368_453_031_918_731_002_211n,
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15 | 512: 35_835_915_874_844_867_368_919_076_489_095_108_449_946_327_955_754_392_558_399_825_615_420_669_938_882_575_126_094_039_892_345_713_852_759n,
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16 | 1024: 5_016_456_510_113_118_655_434_598_811_035_278_955_030_765_345_404_790_744_303_017_523_831_112_055_108_147_451_509_157_692_220_295_382_716_162_651_878_526_895_249_385_292_291_816_524_375_083_746_691_371_804_094_271_873_160_484_737_966_720_260_389_217_684_476_157_468_082_573n,
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17 | };
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18 |
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19 | const FNV_OFFSETS = {
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20 | 32: 2_166_136_261n,
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21 | 64: 14_695_981_039_346_656_037n,
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22 | 128: 144_066_263_297_769_815_596_495_629_667_062_367_629n,
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23 | 256: 100_029_257_958_052_580_907_070_968_620_625_704_837_092_796_014_241_193_945_225_284_501_741_471_925_557n,
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24 | 512: 9_659_303_129_496_669_498_009_435_400_716_310_466_090_418_745_672_637_896_108_374_329_434_462_657_994_582_932_197_716_438_449_813_051_892_206_539_805_784_495_328_239_340_083_876_191_928_701_583_869_517_785n,
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25 | 1024: 14_197_795_064_947_621_068_722_070_641_403_218_320_880_622_795_441_933_960_878_474_914_617_582_723_252_296_732_303_717_722_150_864_096_521_202_355_549_365_628_174_669_108_571_814_760_471_015_076_148_029_755_969_804_077_320_157_692_458_563_003_215_304_957_150_157_403_644_460_363_550_505_412_711_285_966_361_610_267_868_082_893_823_963_790_439_336_411_086_884_584_107_735_010_676_915n,
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26 | };
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27 |
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28 |
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29 | exports.fnv1a = function fnv1a(string, {size = 32} = {}) {
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30 | if (!FNV_PRIMES[size]) {
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31 | throw new Error('The `size` option must be one of 32, 64, 128, 256, 512, or 1024');
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32 | }
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33 |
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34 | let hash = FNV_OFFSETS[size];
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35 | const fnvPrime = FNV_PRIMES[size];
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36 |
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37 |
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38 | let isUnicoded = false;
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39 |
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40 | for (let index = 0; index < string.length; index++) {
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41 | let characterCode = string.charCodeAt(index);
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42 |
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43 |
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44 | if (characterCode > 0x7F && !isUnicoded) {
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45 | string = unescape(encodeURIComponent(string));
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46 | characterCode = string.charCodeAt(index);
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47 | isUnicoded = true;
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48 | }
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49 |
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50 | hash ^= BigInt(characterCode);
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51 | hash = BigInt.asUintN(size, hash * fnvPrime);
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52 | }
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53 |
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54 | return hash;
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55 | } |
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