39 lines
914 B
JavaScript
39 lines
914 B
JavaScript
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const MszRandomInt = function(min, max) {
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let ret = 0;
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const range = max - min;
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const bitsNeeded = Math.ceil(Math.log2(range));
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if(bitsNeeded > 53)
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return -1;
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const bytesNeeded = Math.ceil(bitsNeeded / 8),
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mask = Math.pow(2, bitsNeeded) - 1;
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const bytes = new Uint8Array(bytesNeeded);
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crypto.getRandomValues(bytes);
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let p = (bytesNeeded - 1) * 8;
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for(let i = 0; i < bytesNeeded; ++i) {
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ret += bytes[i] * Math.pow(2, p);
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p -= 8;
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}
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ret &= mask;
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if(ret >= range)
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return MszRandomInt(min, max);
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return min + ret;
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};
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const MszUniqueStr = (function() {
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const chars = 'AaBbCcDdEeFfGgHhIiJjKkLlMmNnOoPpQqRrSsTtUuVvWwXxYyZz0123456789';
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return function(length) {
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let str = '';
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for(let i = 0; i < length; ++i)
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str += chars[MszRandomInt(0, chars.length)];
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return str;
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};
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})();
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