Spaces:
Configuration error
Configuration error
File size: 998 Bytes
5641073 |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 |
'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 : $Number;
// this is common to both branches
var intValue = Z(0);
for (var i = 0; i < rawBytes.length; i++) {
intValue += Z(rawBytes[i]) * Z($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
};
|