Chore: avoid adding too much pressure on backup source

This commit is contained in:
SukkaW 2025-07-28 00:29:28 +08:00
parent e9567f6488
commit 2954a1b7c4

View File

@ -5,6 +5,7 @@ import { nullthrow } from 'foxts/guard';
import { TextLineStream } from 'foxts/text-line-stream';
import { ProcessLineStream } from './process-line';
import { AdGuardFilterIgnoreUnsupportedLinesStream } from './parse-filter/filters';
import { appendArrayInPlace } from 'foxts/append-array-in-place';
// eslint-disable-next-line sukka/unicorn/custom-error-definition -- typescript is better
class CustomAbortError extends Error {
@ -22,9 +23,9 @@ export async function fetchAssets(
const createFetchFallbackPromise = async (url: string, index: number) => {
if (index >= 0) {
// Most assets can be downloaded within 250ms. To avoid wasting bandwidth, we will wait for 500ms before downloading from the fallback URL.
// To avoid wasting bandwidth, we will wait for a few time before downloading from the fallback URL.
try {
await waitWithAbort(50 + (index + 1) * 150, controller.signal);
await waitWithAbort(200 + (index + 1) * 400, controller.signal);
} catch {
console.log(picocolors.gray('[fetch cancelled early]'), picocolors.gray(url));
throw reusedCustomAbortError;
@ -36,7 +37,9 @@ export async function fetchAssets(
}
const res = await $$fetch(url, { signal: controller.signal, ...defaultRequestInit });
let stream = nullthrow(res.body, url + ' has an empty body').pipeThrough(new TextDecoderStream()).pipeThrough(new TextLineStream({ skipEmptyLines: processLine }));
let stream = nullthrow(res.body, url + ' has an empty body')
.pipeThrough(new TextDecoderStream())
.pipeThrough(new TextLineStream({ skipEmptyLines: processLine }));
if (processLine) {
stream = stream.pipeThrough(new ProcessLineStream());
}
@ -53,11 +56,15 @@ export async function fetchAssets(
return arr;
};
const primaryPromise = createFetchFallbackPromise(url, -1);
if (!fallbackUrls || fallbackUrls.length === 0) {
return createFetchFallbackPromise(url, -1);
return primaryPromise;
}
return Promise.any([
createFetchFallbackPromise(url, -1),
...fallbackUrls.map(createFetchFallbackPromise)
]);
return Promise.any(
appendArrayInPlace(
[primaryPromise],
fallbackUrls.map(createFetchFallbackPromise)
)
);
}