mirror of
https://github.com/spacebarchat/server.git
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67 lines
1.7 KiB
TypeScript
67 lines
1.7 KiB
TypeScript
/*
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Spacebar: A FOSS re-implementation and extension of the Discord.com backend.
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Copyright (C) 2023 Spacebar and Spacebar Contributors
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU Affero General Public License as published
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by the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU Affero General Public License for more details.
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You should have received a copy of the GNU Affero General Public License
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along with this program. If not, see <https://www.gnu.org/licenses/>.
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*/
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const alphabet =
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"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+";
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// binary to string lookup table
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const b2s = alphabet.split("");
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// string to binary lookup table
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// 123 == 'z'.charCodeAt(0) + 1
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const s2b = new Array(123);
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for (let i = 0; i < alphabet.length; i++) {
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s2b[alphabet.charCodeAt(i)] = i;
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}
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// number to base64
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export const ntob = (n: number): string => {
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if (n < 0) return `-${ntob(-n)}`;
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let lo = n >>> 0;
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let hi = (n / 4294967296) >>> 0;
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let right = "";
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while (hi > 0) {
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right = b2s[0x3f & lo] + right;
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lo >>>= 6;
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lo |= (0x3f & hi) << 26;
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hi >>>= 6;
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}
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let left = "";
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do {
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left = b2s[0x3f & lo] + left;
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lo >>>= 6;
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} while (lo > 0);
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return left + right;
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};
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// base64 to number
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export const bton = (base64: string) => {
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let number = 0;
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const sign = base64.charAt(0) === "-" ? 1 : 0;
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for (let i = sign; i < base64.length; i++) {
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number = number * 64 + s2b[base64.charCodeAt(i)];
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}
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return sign ? -number : number;
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};
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