| 'use strict'; |
| |
| var $TypeError = require('es-errors/type'); |
| |
| var IsDetachedBuffer = require('./IsDetachedBuffer'); |
| var IsFixedLengthArrayBuffer = require('./IsFixedLengthArrayBuffer'); |
| |
| var isDataViewWithBufferWitnessRecord = require('../helpers/records/data-view-with-buffer-witness-record'); |
| |
| var dataViewBuffer = require('data-view-buffer'); |
| var dataViewByteLength = require('data-view-byte-length'); |
| var dataViewByteOffset = require('data-view-byte-offset'); |
| |
| // https://262.ecma-international.org/15.0/#sec-isviewoutofbounds |
| |
| module.exports = function IsViewOutOfBounds(viewRecord) { |
| if (!isDataViewWithBufferWitnessRecord(viewRecord)) { |
| throw new $TypeError('Assertion failed: `viewRecord` must be a DataView With Buffer Witness Record'); |
| } |
| |
| var view = viewRecord['[[Object]]']; // step 1 |
| |
| var bufferByteLength = viewRecord['[[CachedBufferByteLength]]']; // step 2 |
| |
| if (IsDetachedBuffer(dataViewBuffer(view)) !== (bufferByteLength === 'DETACHED')) { |
| // step 3 |
| throw new $TypeError('Assertion failed: `IsDetachedBuffer(dataViewBuffer(view))` must be true if and only if `bufferByteLength === ~DETACHED~'); |
| } |
| |
| if (bufferByteLength === 'DETACHED') { |
| return true; // step 4 |
| } |
| |
| var byteOffsetStart = dataViewByteOffset(view); // step 5 |
| |
| var isFixed = IsFixedLengthArrayBuffer(dataViewBuffer(view)); |
| |
| var viewByteLength = isFixed ? dataViewByteLength(view) : 'AUTO'; // view.[[ByteLength]] |
| var byteOffsetEnd = viewByteLength === 'AUTO' ? bufferByteLength : byteOffsetStart + viewByteLength; // steps 6 - 7 |
| |
| if (byteOffsetStart > bufferByteLength || byteOffsetEnd > bufferByteLength) { |
| return true; // step 8 |
| } |
| |
| // 9. NOTE: 0-length DataViews are not considered out-of-bounds. |
| |
| return false; // step 10 |
| }; |