p-gather

Execute Promise in parallel with concurrency support and gather all the results.

p-gather is similar with co-parallel, but p-gather will gather all the result of these Promise, even those Promise throw error.

Installation

$ npm install p-gather

Example

const gather = require('p-gather');
const thread = gather.thread;

function sleep(n) {
  return new Promise(resolve => {
    setTimeout(resolve, n);
  });
}

let index = 0;
async function random() {
  let i = index++;
  await sleep(Math.random() * 100);
  if (Math.random() > 0.5) {
    throw new Error('error');
  }
  return i;
}

(async =>{
  const ret = await gather(thread(random, 10));
  console.log(ret);
})();

=>

[
  { isError: true, error: [Error: error] },
  { isError: true, error: [Error: error] },
  { isError: true, error: [Error: error] },
  { isError: true, error: [Error: error] },
  { isError: true, error: [Error: error] },
  { isError: false, value: 5 },
  { isError: false, value: 6 },
  { isError: false, value: 7 },
  { isError: true, error: [Error: error] },
  { isError: true, error: [Error: error] }
]

API

gather(Promise, [concurrency])

Execute Promise array in parallel, with the given concurrency defaulting to 5, and gather the result

gather.thread(Function, [concurrency])

Run a function in parallel N times. Function must return a Promise Object.

License

MIT