37 lines
1.5 KiB
JavaScript
37 lines
1.5 KiB
JavaScript
'use strict';
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var $ = require('../internals/export');
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var fails = require('../internals/fails');
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var ArrayBufferModule = require('../internals/array-buffer');
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var anObject = require('../internals/an-object');
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var toAbsoluteIndex = require('../internals/to-absolute-index');
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var toLength = require('../internals/to-length');
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var speciesConstructor = require('../internals/species-constructor');
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var ArrayBuffer = ArrayBufferModule.ArrayBuffer;
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var DataView = ArrayBufferModule.DataView;
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var nativeArrayBufferSlice = ArrayBuffer.prototype.slice;
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var INCORRECT_SLICE = fails(function () {
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return !new ArrayBuffer(2).slice(1, undefined).byteLength;
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});
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// `ArrayBuffer.prototype.slice` method
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// https://tc39.es/ecma262/#sec-arraybuffer.prototype.slice
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$({ target: 'ArrayBuffer', proto: true, unsafe: true, forced: INCORRECT_SLICE }, {
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slice: function slice(start, end) {
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if (nativeArrayBufferSlice !== undefined && end === undefined) {
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return nativeArrayBufferSlice.call(anObject(this), start); // FF fix
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}
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var length = anObject(this).byteLength;
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var first = toAbsoluteIndex(start, length);
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var fin = toAbsoluteIndex(end === undefined ? length : end, length);
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var result = new (speciesConstructor(this, ArrayBuffer))(toLength(fin - first));
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var viewSource = new DataView(this);
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var viewTarget = new DataView(result);
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var index = 0;
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while (first < fin) {
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viewTarget.setUint8(index++, viewSource.getUint8(first++));
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} return result;
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}
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});
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