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https://github.com/retspen/webvirtcloud
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33 lines
748 B
JavaScript
33 lines
748 B
JavaScript
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"use strict";
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Object.defineProperty(exports, "__esModule", {
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value: true
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});
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exports.default = adler32;
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// Note: adler32 takes 12% for level 0 and 2% for level 6.
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// It doesn't worth to make additional optimizationa as in original.
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// Small size is preferable.
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function adler32(adler, buf, len, pos) {
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var s1 = adler & 0xffff | 0,
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s2 = adler >>> 16 & 0xffff | 0,
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n = 0;
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while (len !== 0) {
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// Set limit ~ twice less than 5552, to keep
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// s2 in 31-bits, because we force signed ints.
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// in other case %= will fail.
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n = len > 2000 ? 2000 : len;
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len -= n;
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do {
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s1 = s1 + buf[pos++] | 0;
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s2 = s2 + s1 | 0;
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} while (--n);
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s1 %= 65521;
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s2 %= 65521;
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}
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return s1 | s2 << 16 | 0;
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}
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