46 lines
1.5 KiB
JavaScript
46 lines
1.5 KiB
JavaScript
|
'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
|
|||
|
|
};
|