39 lines
1.6 KiB
JavaScript
39 lines
1.6 KiB
JavaScript
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'use strict';
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var $TypeError = require('es-errors/type');
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// https://tc39.es/ecma262/#sec-arraybufferbytelength
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var IsDetachedBuffer = require('./IsDetachedBuffer');
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var isArrayBuffer = require('is-array-buffer');
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var isSharedArrayBuffer = require('is-shared-array-buffer');
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var arrayBufferByteLength = require('array-buffer-byte-length');
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var isGrowable = false; // TODO: support this
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module.exports = function ArrayBufferByteLength(arrayBuffer, order) {
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var isSAB = isSharedArrayBuffer(arrayBuffer);
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if (!isArrayBuffer(arrayBuffer) && !isSAB) {
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throw new $TypeError('Assertion failed: `arrayBuffer` must be an ArrayBuffer or a SharedArrayBuffer');
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}
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if (order !== 'SEQ-CST' && order !== 'UNORDERED') {
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throw new $TypeError('Assertion failed: `order` must be ~SEQ-CST~ or ~UNORDERED~');
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}
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// 1. If IsSharedArrayBuffer(arrayBuffer) is true and arrayBuffer has an [[ArrayBufferByteLengthData]] internal slot, then
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// TODO: see if IsFixedLengthArrayBuffer can be used here in the spec instead
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if (isSAB && isGrowable) { // step 1
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// a. Let bufferByteLengthBlock be arrayBuffer.[[ArrayBufferByteLengthData]].
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// b. Let rawLength be GetRawBytesFromSharedBlock(bufferByteLengthBlock, 0, BIGUINT64, true, order).
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// c. Let isLittleEndian be the value of the [[LittleEndian]] field of the surrounding agent's Agent Record.
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// d. Return ℝ(RawBytesToNumeric(BIGUINT64, rawLength, isLittleEndian)).
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}
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if (IsDetachedBuffer(arrayBuffer)) {
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throw new $TypeError('Assertion failed: `arrayBuffer` must not be detached'); // step 2
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}
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return arrayBufferByteLength(arrayBuffer);
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};
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