Jaco Greeff
e832aebb07
* Add toU8a conversions * Add u8a utilities * @polkadot/rlp with encoding * Decoding test runthrough * Update util locations * Convert util-triehash to use util-rlp * Allow keccak from Uint8Array * Pass Uint8Array to keccak input * Update documentation * Skip some doc generation * Update @polkadot/dev * Update doc typo * Update allocations * Retrieve tests from ethereumjs-testing * Simplify test retrieval * Exclude etereumjs-testing from flow
31 lines
882 B
JavaScript
31 lines
882 B
JavaScript
// Copyright 2017-2018 Jaco Greeff
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// This software may be modified and distributed under the terms
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// of the ISC license. See the LICENSE file for details.
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// @flow
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/**
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@name u8aConcat
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@signature u8aConcat (values: Array<Uint8Array>): Uint8Array
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@summary Creates a concatenated Uint8Array from the inputs.
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@description
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Concatenates the input arrays into a single `UInt8Array`.
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@example
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import { u8aConcat } from '@polkadot/util';
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u8aConcat([
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new Uint8Array([1, 2, 3]),
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new Uint8Array([4, 5, 6])
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]); // [1, 2, 3, 4, 5, 6]
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*/
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module.exports = function u8aConcat (list: Array<Uint8Array>): Uint8Array {
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const length = list.reduce((total, item) => total + item.length, 0);
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let offset = 0;
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return list.reduce((result, item) => {
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result.set(item, offset);
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offset += item.length;
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return result;
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}, new Uint8Array(length));
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};
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