webstreamr-github/src/extractor/ExtractorRegistry.ts

61 lines
1.9 KiB
TypeScript

import TTLCache from '@isaacs/ttlcache';
import winston from 'winston';
import { Extractor } from './types';
import { Context, CountryCode, UrlResult } from '../types';
import { NotFoundError } from '../error';
export class ExtractorRegistry {
private readonly logger: winston.Logger;
private readonly extractors: Extractor[];
private readonly urlResultCache: TTLCache<string, UrlResult[]>;
public constructor(logger: winston.Logger, extractors: Extractor[]) {
this.logger = logger;
this.extractors = extractors;
this.urlResultCache = new TTLCache({ max: 1024 });
}
public readonly handle = async (ctx: Context, url: URL, countryCode: CountryCode, title?: string | undefined): Promise<UrlResult[]> => {
const extractor = this.extractors.find(extractor => extractor.supports(ctx, url));
if (!extractor) {
return [];
}
const normalizedUrl = extractor.normalize(url);
let urlResults = this.urlResultCache.get(normalizedUrl.href) ?? [];
if (this.urlResultCache.has(normalizedUrl.href)) {
return urlResults.map(urlResult => ({ ...urlResult, ttl: this.urlResultCache.getRemainingTTL(normalizedUrl.href) }));
}
this.logger.info(`Extract stream URL using ${extractor.id} extractor from ${url}`, ctx);
try {
urlResults = await extractor.extract(ctx, normalizedUrl, countryCode, title);
} catch (error) {
if (error instanceof NotFoundError) {
this.urlResultCache.set(normalizedUrl.href, urlResults, { ttl: extractor.ttl });
return [];
}
return [
{
url,
isExternal: true,
error,
label: url.host,
sourceId: `${extractor.id}`,
meta: {
countryCode,
...(title && { title }),
},
},
];
}
this.urlResultCache.set(normalizedUrl.href, urlResults, { ttl: extractor.ttl });
return urlResults;
};
}