mirror of https://github.com/sussy-code/smov.git
46 lines
2.0 KiB
JavaScript
46 lines
2.0 KiB
JavaScript
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/* port of https://github.com/beautify-web/js-beautify/blob/master/python/jsbeautifier/unpackers/packer.py (MIT) */
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const unpacker = {
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unpack: function (str) {
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var params = unpacker.filterargs(str);
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var payload = params[0], symtab = params[1], radix = params[2], count = params[3];
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if (count !== symtab.length) {
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throw new Error("Malformed p.a.c.k.e.r. symtab. (" + count + " != " + symtab.length + ")");
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}
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var unbase = unpacker.unbaser(radix);
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var lookup = (word) => symtab[unbase(word)] || word;
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var source = payload.replace(/\b\w+\b/g, lookup);
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return source;
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},
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filterargs: function(str) {
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/* [\s\S] insteadof . because javascript has no dotall modifier */
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var juicers = [
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/}\('([\s\S]*)', *(\d+), *(\d+), *'([\s\S]*)'\.split\('\|'\), *(\d+), *([\s\S]*)\)\)/,
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/}\('([\s\S]*)', *(\d+), *(\d+), *'([\s\S]*)'\.split\('\|'\)/
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];
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for (var c = 0; c < juicers.length; ++c) {
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var m, juicer = juicers[c];
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// eslint-disable-next-line no-cond-assign
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if (m = juicer.exec(str)) {
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return [m[1], m[4].split('|'), parseInt(m[2]), parseInt(m[3])];
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}
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}
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throw new Error("Could not make sense of p.a.c.k.e.r data (unexpected code structure)");
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},
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alphabet: {
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62: "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ",
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95: '!"#$%&\'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~'
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},
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unbaser: function(base)
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{
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if (2 <= base <= 36) return (str) => parseInt(str, base);
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var dictionary = {};
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var alphabet = unpacker.alphabet[base];
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if (!alphabet) throw new Error("Unsupported encoding");
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for (var c = 0; c < alphabet.length; ++alphabet) {
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dictionary[alphabet[c]] = c;
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}
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return (str) => str.split("").reverse().reduce((cipher, ind) => Math.pow(base, ind) * dictionary[cipher]);
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}
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};
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export { unpacker };
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