lix-website/themes/lix/assets/bootstrap/node_modules/es-abstract/helpers/bytesAsInteger.js

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2024-04-27 03:39:10 +00:00
'use strict';
var GetIntrinsic = require('get-intrinsic');
var $pow = GetIntrinsic('%Math.pow%');
var $Number = GetIntrinsic('%Number%');
var $BigInt = GetIntrinsic('%BigInt%', true);
module.exports = function bytesAsInteger(rawBytes, elementSize, isUnsigned, isBigInt) {
var Z = isBigInt ? $BigInt : $Number;
// this is common to both branches
var intValue = Z(0);
for (var i = 0; i < rawBytes.length; i++) {
intValue += Z(rawBytes[i] * $pow(2, 8 * i));
}
/*
Let intValue be the byte elements of rawBytes concatenated and interpreted as a bit string encoding of an unsigned little-endian binary number.
*/
if (!isUnsigned) { // steps 5-6
// Let intValue be the byte elements of rawBytes concatenated and interpreted as a bit string encoding of a binary little-endian 2's complement number of bit length elementSize × 8.
var bitLength = elementSize * 8;
if (rawBytes[elementSize - 1] & 0x80) {
intValue -= Z($pow(2, bitLength));
}
}
return intValue; // step 7
};