30 lines
No EOL
1.1 KiB
JavaScript
30 lines
No EOL
1.1 KiB
JavaScript
import {query} from 'dns-query';
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class FallBackResolver {
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constructor() {
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this._servers = ['1.1.1.1', '8.8.8.8'];
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this._cache = JSON.parse(localStorage.getItem('dns-cache')) || {};
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}
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async query(domain, type) {
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const key = domain + ':' + type;
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if (key in this._cache && this._cache[key].time > Date.now() - 1000 * 60 * 60) {
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const age_seconds = Math.ceil(Date.now() / 1000 - this._cache[key].time / 1000);
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console.log('cache hit', key, this._cache[key].ttl - age_seconds);
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return [this._cache[key].data];
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}
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const result = await query(
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{question: {type: type, name: domain}},
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{
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endpoints: this._servers,
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}
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)
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const first = result.answers[0];
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this._cache[key] = {time: Date.now(), ...first}; // TODO hadle multiple answers
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localStorage.setItem('dns-cache', JSON.stringify(this._cache));
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console.log('cache miss', key, first.ttl);
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return [first.data];
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}
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}
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export default FallBackResolver; |