| 'use strict'; |
| |
| var $TypeError = require('es-errors/type'); |
| |
| var IsFixedLengthArrayBuffer = require('./IsFixedLengthArrayBuffer'); |
| var IsViewOutOfBounds = require('./IsViewOutOfBounds'); |
| |
| 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-getviewbytelength |
| |
| module.exports = function GetViewByteLength(viewRecord) { |
| if (!isDataViewWithBufferWitnessRecord(viewRecord)) { |
| throw new $TypeError('Assertion failed: `viewRecord` must be a DataView with Buffer Witness Record'); |
| } |
| |
| if (IsViewOutOfBounds(viewRecord)) { |
| throw new $TypeError('Assertion failed: `viewRecord` is out of bounds'); // step 1 |
| } |
| |
| var view = viewRecord['[[Object]]']; // step 2 |
| |
| var viewByteLength = dataViewByteLength(view); // view.[[ByteLength]] |
| if (viewByteLength !== 'AUTO') { |
| return viewByteLength; // step 3 |
| } |
| |
| if (IsFixedLengthArrayBuffer(dataViewBuffer(view))) { |
| throw new $TypeError('Assertion failed: DataView’s ArrayBuffer is not fixed length'); // step 4 |
| } |
| |
| var byteOffset = dataViewByteOffset(view); // step 5 |
| |
| var byteLength = viewRecord['[[CachedBufferByteLength]]']; // step 6 |
| |
| if (byteLength === 'DETACHED') { |
| throw new $TypeError('Assertion failed: DataView’s ArrayBuffer is detached'); // step 7 |
| } |
| |
| return byteLength - byteOffset; // step 8 |
| }; |