/* * Copyright (C) 2023 Yomitan Authors * Copyright (C) 2021-2022 Yomichan Authors * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <https://www.gnu.org/licenses/>. */ /** * Class containing generic ArrayBuffer utility functions. */ class ArrayBufferUtil { /** * Decodes the contents of an ArrayBuffer using UTF8. * @param {ArrayBuffer} arrayBuffer The input ArrayBuffer. * @returns {string} A UTF8-decoded string. */ static arrayBufferUtf8Decode(arrayBuffer) { try { return new TextDecoder('utf-8').decode(arrayBuffer); } catch (e) { return decodeURIComponent(escape(this.arrayBufferToBinaryString(arrayBuffer))); } } /** * Converts the contents of an ArrayBuffer to a base64 string. * @param {ArrayBuffer} arrayBuffer The input ArrayBuffer. * @returns {string} A base64 string representing the binary content. */ static arrayBufferToBase64(arrayBuffer) { return btoa(this.arrayBufferToBinaryString(arrayBuffer)); } /** * Converts the contents of an ArrayBuffer to a binary string. * @param {ArrayBuffer} arrayBuffer The input ArrayBuffer. * @returns {string} A string representing the binary content. */ static arrayBufferToBinaryString(arrayBuffer) { const bytes = new Uint8Array(arrayBuffer); try { return String.fromCharCode(...bytes); } catch (e) { let binary = ''; for (let i = 0, ii = bytes.byteLength; i < ii; ++i) { binary += String.fromCharCode(bytes[i]); } return binary; } } /** * Converts a base64 string to an ArrayBuffer. * @param {string} content The binary content string encoded in base64. * @returns {ArrayBuffer} A new `ArrayBuffer` object corresponding to the specified content. */ static base64ToArrayBuffer(content) { const binaryContent = atob(content); const length = binaryContent.length; const array = new Uint8Array(length); for (let i = 0; i < length; ++i) { array[i] = binaryContent.charCodeAt(i); } return array.buffer; } }