securityos/node_modules/es-abstract/2024/ValidateAtomicAccess.js

44 lines
1.3 KiB
JavaScript

'use strict';
var $RangeError = require('es-errors/range');
var $TypeError = require('es-errors/type');
var ToIndex = require('./ToIndex');
var TypedArrayElementSize = require('./TypedArrayElementSize');
var TypedArrayLength = require('./TypedArrayLength');
var isTypedArrayWithBufferWitnessRecord = require('../helpers/records/typed-array-with-buffer-witness-record');
var typedArrayByteOffset = require('typed-array-byte-offset');
// https://262.ecma-international.org/15.0/#sec-validateatomicaccess
module.exports = function ValidateAtomicAccess(taRecord, requestIndex) {
if (!isTypedArrayWithBufferWitnessRecord(taRecord)) {
throw new $TypeError('Assertion failed: `taRecord` must be a TypedArray With Buffer Witness Record');
}
var length = TypedArrayLength(taRecord); // step 1
var accessIndex = ToIndex(requestIndex); // step 2
/*
// this assertion can never be reached
if (!(accessIndex >= 0)) {
throw new $TypeError('Assertion failed: accessIndex >= 0'); // step 4
}
*/
if (accessIndex >= length) {
throw new $RangeError('index out of range'); // step 4
}
var typedArray = taRecord['[[Object]]']; // step 5
var elementSize = TypedArrayElementSize(typedArray); // step 6
var offset = typedArrayByteOffset(typedArray); // step 7
return (accessIndex * elementSize) + offset; // step 8
};