forked from Fediversity/fediversity.eu
121 lines
3.7 KiB
JavaScript
Executable file
121 lines
3.7 KiB
JavaScript
Executable file
'use strict';
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// Adapted from:
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// Copyright (c) 2017-2019 Justin Ridgewell, MIT Licensed, https://github.com/jridgewell/safe-decode-string-component
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// Copyright (c) 2008-2009 Bjoern Hoehrmann <bjoern@hoehrmann.de>, MIT Licensed, http://bjoern.hoehrmann.de/utf-8/decoder/dfa/
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const internals = {};
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exports.decode = function (string) {
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let percentPos = string.indexOf('%');
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if (percentPos === -1) {
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return string;
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}
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let decoded = '';
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let last = 0;
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let codepoint = 0;
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let startOfOctets = percentPos;
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let state = internals.utf8.accept;
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while (percentPos > -1 &&
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percentPos < string.length) {
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const high = internals.resolveHex(string[percentPos + 1], 4);
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const low = internals.resolveHex(string[percentPos + 2], 0);
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const byte = high | low;
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const type = internals.utf8.data[byte];
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state = internals.utf8.data[256 + state + type];
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codepoint = (codepoint << 6) | (byte & internals.utf8.data[364 + type]);
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if (state === internals.utf8.accept) {
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decoded += string.slice(last, startOfOctets);
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decoded += codepoint <= 0xFFFF
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? String.fromCharCode(codepoint)
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: String.fromCharCode(0xD7C0 + (codepoint >> 10), 0xDC00 + (codepoint & 0x3FF));
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codepoint = 0;
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last = percentPos + 3;
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percentPos = string.indexOf('%', last);
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startOfOctets = percentPos;
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continue;
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}
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if (state === internals.utf8.reject) {
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return null;
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}
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percentPos += 3;
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if (percentPos >= string.length ||
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string[percentPos] !== '%') {
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return null;
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}
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}
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return decoded + string.slice(last);
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};
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internals.resolveHex = function (char, shift) {
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const i = internals.hex[char];
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return i === undefined ? 255 : i << shift;
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};
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internals.hex = {
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'0': 0, '1': 1, '2': 2, '3': 3, '4': 4,
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'5': 5, '6': 6, '7': 7, '8': 8, '9': 9,
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'a': 10, 'A': 10, 'b': 11, 'B': 11, 'c': 12,
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'C': 12, 'd': 13, 'D': 13, 'e': 14, 'E': 14,
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'f': 15, 'F': 15
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};
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internals.utf8 = {
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accept: 12,
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reject: 0,
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data: [
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// Maps bytes to character to a transition
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0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
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2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
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3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
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3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
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4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
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5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
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6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 8, 7, 7,
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10, 9, 9, 9, 11, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
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// Maps a state to a new state when adding a transition
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0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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12, 0, 0, 0, 0, 24, 36, 48, 60, 72, 84, 96,
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0, 12, 12, 12, 0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 24, 0, 0, 0, 0, 0, 0, 0, 0,
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0, 24, 24, 24, 0, 0, 0, 0, 0, 0, 0, 0,
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0, 24, 24, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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0, 48, 48, 48, 0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 48, 48, 0, 0, 0, 0, 0, 0, 0, 0,
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0, 48, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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// Maps the current transition to a mask that needs to apply to the byte
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0x7F, 0x3F, 0x3F, 0x3F, 0x00, 0x1F, 0x0F, 0x0F, 0x0F, 0x07, 0x07, 0x07
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]
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};
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