request-multi-streams/examples/request-multi-streams.js

Make multiple http requests. Receive response progress indicators, pipe streams.

'use strict';

const httpMultiStreams = require('../');
const chalk = require('chalk');
const fs = require('fs');

const req1 = {
  options: {
    url:
      'https://cdn.pixabay.com/photo/2014/03/27/21/10/waterfall-299685_1280.jpg',
  },
  numberOfRequests: 10, // Not the same as retries
};

const req2 = {
  options: {
    url: 'http://www.textfiles.com/fun/acronym.txt',
  },
  progressOptions: {
    throttle: 0, // Throttle the progress event to 2000ms, defaults to 1000ms
    delay: 10, // Only start to emit after 1000ms delay, defaults to 0ms
    // lengthHeader: 'x-transfer-length'  // Length header to use, defaults to content-length
  },
  numberOfRequests: 10, // Not the same as retries
};

const reqs = [req1, req2];

function getStreams() {
  const emitters = httpMultiStreams.streams(reqs);

  if (emitters) {
    for (var name in emitters) {
      //listen the events
      emitters[name].on('progress', data => {
        console.log(
          chalk.yellow(
            `Request ${data.reqNumber} for ${data.args.options.url}: ${Number(
              (data.progress.percent * 100).toFixed(1)
            )}% complete`
          )
        );
      });

      emitters[name].on('response', data => {
        console.log(
          chalk.yellow(
            `Request ${data.reqNumber} for ${
              data.args.options.url
            }: got a response`
          )
        );
        if (name === 'http://www.textfiles.com/fun/acronym.txt') {
          data.stream.pipe(
            fs.createWriteStream(`${__dirname}/${data.reqNumber}`)
          );
        }
      });

      emitters[name].on('error', error => {
        console.log(
          chalk.red(
            `Request ${error.reqNumber} for ${
              error.args.options.url
            }: finished on error ${error.error}`
          )
        );
      });

      emitters[name].on('end', end => {
        console.log(
          chalk.green(
            `Request ${end.reqNumber} for ${
              end.args.options.url
            }: finished with sucess`
          )
        );
      });
    }
  }
}

module.exports = getStreams();