diff --git a/packages/backend-common/src/reading/UrlReaderHostMux.ts b/packages/backend-common/src/reading/UrlReaderHostMux.ts new file mode 100644 index 0000000000..446308c54c --- /dev/null +++ b/packages/backend-common/src/reading/UrlReaderHostMux.ts @@ -0,0 +1,40 @@ +/* + * Copyright 2020 Spotify AB + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +import { UrlReader } from './types'; + +/** + * A UrlReader implementation that selects from a set of UrlReaders + * based on the host in the URL. + */ +export class UrlReaderHostMux implements UrlReader { + private readonly readers = new Map(); + + register(host: string, reader: UrlReader): void { + this.readers.set(host, reader); + } + + read(url: string): Promise { + const parsed = new URL(url); + + const reader = this.readers.get(parsed.host); + if (!reader) { + throw new Error(`No reader registered for host ${parsed.host}`); + } + + return reader.read(url); + } +}