43 lines
1.2 KiB
TypeScript
43 lines
1.2 KiB
TypeScript
// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
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import { deferred } from "../async/deferred.ts";
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/**
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* Merge multiple streams into a single one, not taking order into account.
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* If a stream ends before other ones, the other will continue adding data,
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* and the finished one will not add any more data.
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*/
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export function mergeReadableStreams<T>(
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...streams: ReadableStream<T>[]
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): ReadableStream<T> {
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const resolvePromises = streams.map(() => deferred<void>());
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return new ReadableStream<T>({
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start(controller) {
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let mustClose = false;
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Promise.all(resolvePromises)
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.then(() => {
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controller.close();
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})
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.catch((error) => {
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mustClose = true;
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controller.error(error);
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});
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for (const [key, stream] of Object.entries(streams)) {
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(async () => {
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try {
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for await (const data of stream) {
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if (mustClose) {
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break;
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}
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controller.enqueue(data);
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}
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resolvePromises[+key].resolve();
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} catch (error) {
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resolvePromises[+key].reject(error);
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}
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})();
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}
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},
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});
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}
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