| 'use strict'; |
| |
| var $TypeError = require('es-errors/type'); |
| |
| // https://262.ecma-international.org/15.0/#sec-arraybufferbytelength |
| |
| var IsDetachedBuffer = require('./IsDetachedBuffer'); |
| |
| var isArrayBuffer = require('is-array-buffer'); |
| var isSharedArrayBuffer = require('is-shared-array-buffer'); |
| var arrayBufferByteLength = require('array-buffer-byte-length'); |
| |
| var callBound = require('call-bound'); |
| var $sabByteLength = callBound('SharedArrayBuffer.prototype.byteLength', true); |
| |
| var isGrowable = false; // TODO: support this |
| |
| module.exports = function ArrayBufferByteLength(arrayBuffer, order) { |
| var isSAB = isSharedArrayBuffer(arrayBuffer); |
| if (!isArrayBuffer(arrayBuffer) && !isSAB) { |
| throw new $TypeError('Assertion failed: `arrayBuffer` must be an ArrayBuffer or a SharedArrayBuffer'); |
| } |
| if (order !== 'SEQ-CST' && order !== 'UNORDERED') { |
| throw new $TypeError('Assertion failed: `order` must be ~SEQ-CST~ or ~UNORDERED~'); |
| } |
| |
| // 1. If IsSharedArrayBuffer(arrayBuffer) is true and arrayBuffer has an [[ArrayBufferByteLengthData]] internal slot, then |
| // TODO: see if IsFixedLengthArrayBuffer can be used here in the spec instead |
| if (isSAB && isGrowable) { // step 1 |
| // a. Let bufferByteLengthBlock be arrayBuffer.[[ArrayBufferByteLengthData]]. |
| // b. Let rawLength be GetRawBytesFromSharedBlock(bufferByteLengthBlock, 0, BIGUINT64, true, order). |
| // c. Let isLittleEndian be the value of the [[LittleEndian]] field of the surrounding agent's Agent Record. |
| // d. Return ℝ(RawBytesToNumeric(BIGUINT64, rawLength, isLittleEndian)). |
| } |
| |
| if (IsDetachedBuffer(arrayBuffer)) { |
| throw new $TypeError('Assertion failed: `arrayBuffer` must not be detached'); // step 2 |
| } |
| |
| return isSAB ? $sabByteLength(arrayBuffer) : arrayBufferByteLength(arrayBuffer); |
| }; |