如何在p-limit中使用pendingCount？

Question

当我对 API 进行大量调用时，我想要一种方法来限制我同时执行的调用量。

我发现 p-limit 可以完美满足我的需求 https://www.npmjs.com/package/p-limit

现在，我想将当前进度输出给用户。我看到这个库有一个pendingCount属性，但我不知道如何使用它。

任何帮助将不胜感激。

How to use the limit.pendingCount variable in p-limit?有一个类似的问题，但编辑后的答案没有使用pendingCount

我希望能够写“我们仍然缺少 n 个 API 调用”

这是我当前的代码（简化）：

import pLimit from 'p-limit';

const aPromise = [];
const urls = [
"https://www.google.com/search?q=1",
"https://www.google.com/search?q=2",
"https://www.google.com/search?q=3",
"https://www.google.com/search?q=4",
"https://www.google.com/search?q=5",
"https://www.google.com/search?q=6",
"https://www.google.com/search?q=7",
"https://www.google.com/search?q=8"
];

const limit = pLimit(3);

for (const url of urls) {

    try {
        aPromise.push(limit(() => fetch(url)));
    } catch (error) {
        console.error('An error occurred:', error);
    }

}

const res = await Promise.allSettled(aPromise);

for (const x of res) {
    if (x.status == "fulfilled") {
        //process results
    } else if (x.status == "rejected") {
        console.log(`${x.reason}`);
    }
}

添加解决方案，谢谢西蒙

import pLimit from 'p-limit';

const aPromise = [];
const urls = [
"https://www.google.com/search?q=1",
"https://www.google.com/search?q=2",
"https://www.google.com/search?q=3",
"https://www.google.com/search?q=4",
"https://www.google.com/search?q=5",
"https://www.google.com/search?q=6",
"https://www.google.com/search?q=7",
"https://www.google.com/search?q=8"
];

const limit = pLimit(3);

for (const url of urls) {

    try {
        aPromise.push(limit(() => fetch(url)));
    } catch (error) {
        console.error('An error occurred:', error);
    }

}

let nProgressInterval = setInterval( () => {
    printProgress(Math.round(100 - limit.pendingCount * 100 / aPromise.length))
}, 1000);

const res = await Promise.allSettled(aPromise);

clearInterval(nProgressInterval);
nProgressInterval = null;

for (const x of res) {
    if (x.status == "fulfilled") {
        //process results
    } else if (x.status == "rejected") {
        console.log(`${x.reason}`);
    }
}

// This will write the progress number in the same position
function printProgress(progress) {
    process.stdout.clearLine(0);
    process.stdout.cursorTo(0);
    process.stdout.write(`Progreso ${progress}%`);
}

Answer 1

添加解决方案，谢谢西蒙

import pLimit from 'p-limit';

const aPromise = [];
const urls = [
"https://www.google.com/search?q=1",
"https://www.google.com/search?q=2",
"https://www.google.com/search?q=3",
"https://www.google.com/search?q=4",
"https://www.google.com/search?q=5",
"https://www.google.com/search?q=6",
"https://www.google.com/search?q=7",
"https://www.google.com/search?q=8"
];

const limit = pLimit(3);

for (const url of urls) {

    try {
        aPromise.push(limit(() => fetch(url)));
    } catch (error) {
        console.error('An error occurred:', error);
    }

}

let nProgressInterval = setInterval( () => {
    printProgress(Math.round(100 - limit.pendingCount * 100 / aPromise.length))
}, 1000);

const res = await Promise.allSettled(aPromise);

clearInterval(nProgressInterval);
nProgressInterval = null;

for (const x of res) {
    if (x.status == "fulfilled") {
        //process results
    } else if (x.status == "rejected") {
        console.log(`${x.reason}`);
    }
}

// This will write the progress number in the same position
function printProgress(progress) {
    process.stdout.clearLine(0);
    process.stdout.cursorTo(0);
    process.stdout.write(`Progreso ${progress}%`);
}