如何减慢发出请求的速度？

Question

I have problem with too fast requesting. When my script makes too many requests per second Google throws an error net::ERR_INSUFFICIENT_RESOURCES

I want to make one request per 20ms. How I can achieve that?

---

This is how my main function look at this moment...

const symbolsArr = reader.result.split("\n").map((str) => str.trim()); //symbolsArr is just rergular array, except it's source is from .txt file
    function loopFunction(error_symbol) {
      for (const symbol of symbolsArr) {
        setTimeout(getData(symbol), 5000); //I tried to use setTimeout but it not helps
      }
      return console.log(error_symbol);
    }
    loopFunction(error_symbols);

---

And my fetcher...

error_symbols = [];

function getData(symbol) {
  fetch(
    `https://cors-anywhere.herokuapp.com/` +
      `https://eodhistoricaldata.com/api/fundamentals/${symbol}?api_token= (don't look at my secret token :))`,
    {
      method: "get",
    }
  )
    .then((res) => {
      if (res.ok) {
        return res.json();
      } else {
        throw new Error(`Symbol ${symbol} is 'empty'`);
      }
    })
    .then((data) => {
      console.log(data);
      var myJSON = JSON.stringify(data);
      saveFile(myJSON, `${symbol}-json.txt`, "text/plain");
    })
    .catch((error) => {
      error_symbols.push(symbol);
      throw error + symbol;
    });
}

Pretty simple, I have to somehow put cooldown on fetcher

Answer 1

try this

const symbolsArr = reader.result.split("\n").map((str) => str.trim()); //symbolsArr is just rergular array, except it's source is from .txt file
async function loopFunction(error_symbol) {
      for (const symbol of symbolsArr) {
        await setTimeout(getData(symbol), 5000); //I tried to use setTimeout but it not helps
      }
      return console.log(error_symbol);
    }
    loopFunction(error_symbols);

the fetch api is using async promises to handle requests.

i am pretty sure u need to set a await to make the loop wait on each loopin till the fulfillment is done.