61 lines
2.1 KiB
JavaScript
61 lines
2.1 KiB
JavaScript
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"use strict";
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var __importDefault = (this && this.__importDefault) || function (mod) {
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return (mod && mod.__esModule) ? mod : { "default": mod };
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};
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Object.defineProperty(exports, "__esModule", { value: true });
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exports.filetypeextension = exports.filetypemime = exports.filetypename = exports.filetypeinfo = void 0;
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const pattern_tree_1 = __importDefault(require("./model/pattern-tree"));
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const toHex_1 = require("./model/toHex");
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const patternTree = pattern_tree_1.default();
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const filetypeinfo = (bytes) => {
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let tree = patternTree;
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for (const k of Object.keys(tree.offset)) {
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const offset = toHex_1.fromHex(k);
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const offsetExceedsFile = offset >= bytes.length;
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if (offsetExceedsFile) {
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continue;
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}
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const node = patternTree.offset[k];
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const guessed = walkTree(offset, bytes, node);
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if (guessed.length > 0) {
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return guessed;
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}
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}
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if (tree.noOffset === null) {
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return [];
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}
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return walkTree(0, bytes, tree.noOffset);
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};
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exports.filetypeinfo = filetypeinfo;
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const walkTree = (index, bytes, node) => {
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let step = node;
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let guessFile = [];
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while (true) {
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const currentByte = toHex_1.toHex(bytes[index]);
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if (step.bytes["?"] && !step.bytes[currentByte]) {
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step = step.bytes["?"];
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}
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else {
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step = step.bytes[currentByte];
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}
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if (!step) {
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return guessFile;
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}
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if (step && step.matches) {
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guessFile = step.matches.slice(0);
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}
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index += 1;
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}
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};
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exports.default = exports.filetypeinfo;
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const filetypename = (bytes) => exports.filetypeinfo(bytes).map((e) => e.typename);
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exports.filetypename = filetypename;
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const filetypemime = (bytes) => exports.filetypeinfo(bytes)
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.map((e) => (e.mime ? e.mime : null))
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.filter((x) => x !== null);
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exports.filetypemime = filetypemime;
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const filetypeextension = (bytes) => exports.filetypeinfo(bytes)
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.map((e) => (e.extension ? e.extension : null))
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.filter((x) => x !== null);
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exports.filetypeextension = filetypeextension;
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