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- 'use strict';
- var $TypeError = require('es-errors/type');
- var GetPrototypeFromConstructor = require('./GetPrototypeFromConstructor');
- var IsConstructor = require('./IsConstructor');
- var IsDetachedBuffer = require('./IsDetachedBuffer');
- var OrdinarySetPrototypeOf = require('./OrdinarySetPrototypeOf');
- var isInteger = require('../helpers/isInteger');
- var isArrayBuffer = require('is-array-buffer');
- var arrayBufferSlice = require('arraybuffer.prototype.slice');
- // https://262.ecma-international.org/12.0/#sec-clonearraybuffer
- module.exports = function CloneArrayBuffer(srcBuffer, srcByteOffset, srcLength, cloneConstructor) {
- if (!isArrayBuffer(srcBuffer)) {
- throw new $TypeError('Assertion failed: `srcBuffer` must be an ArrayBuffer instance');
- }
- if (!isInteger(srcByteOffset) || srcByteOffset < 0) {
- throw new $TypeError('Assertion failed: `srcByteOffset` must be a non-negative integer');
- }
- if (!isInteger(srcLength) || srcLength < 0) {
- throw new $TypeError('Assertion failed: `srcLength` must be a non-negative integer');
- }
- if (!IsConstructor(cloneConstructor)) {
- throw new $TypeError('Assertion failed: `cloneConstructor` must be a constructor');
- }
- // 3. Let targetBuffer be ? AllocateArrayBuffer(cloneConstructor, srcLength).
- var proto = GetPrototypeFromConstructor(cloneConstructor, '%ArrayBufferPrototype%'); // step 3, kinda
- if (IsDetachedBuffer(srcBuffer)) {
- throw new $TypeError('`srcBuffer` must not be a detached ArrayBuffer'); // step 4
- }
- /*
- 5. Let srcBlock be srcBuffer.[[ArrayBufferData]].
- 6. Let targetBlock be targetBuffer.[[ArrayBufferData]].
- 7. Perform CopyDataBlockBytes(targetBlock, 0, srcBlock, srcByteOffset, srcLength).
- */
- var targetBuffer = arrayBufferSlice(srcBuffer, srcByteOffset, srcByteOffset + srcLength); // steps 5-7
- OrdinarySetPrototypeOf(targetBuffer, proto); // step 3
- return targetBuffer; // step 8
- };
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