Introduction to Asynckit

Asynckit is a powerful JavaScript library that simplifies the process of handling asynchronous operations. By offering a collection of utility functions, Asynckit allows developers to manage concurrent tasks efficiently. Below, we’ll explore various APIs provided by Asynckit and demonstrate their usage through code snippets.

Parallel Execution with parallel

  const asynckit = require('asynckit');
  const tasks = [1, 2, 3, 4];

  asynckit.parallel(tasks, function (item, done) {
    setTimeout(() => {
      console.log('Processing item', item);
      done(null, item * 2);
    }, 1000);
  }, function (err, results) {
    console.log('All tasks completed:', results);
  });

Series Execution with series

  const asynckit = require('asynckit');
  const tasks = [1, 2, 3, 4];

  asynckit.series(tasks, function (item, done) {
    setTimeout(() => {
      console.log('Processing item', item);
      done(null, item * 2);
    }, 1000);
  }, function (err, results) {
    console.log('Series tasks completed:', results);
  });

Waterfall Execution with waterfall

  const asynckit = require('asynckit');

  asynckit.waterfall([
    function (callback) {
      setTimeout(() => {
        console.log('Task 1');
        callback(null, 1);
      }, 1000);
    },
    function (result, callback) {
      setTimeout(() => {
        console.log('Task 2, result from task 1:', result);
        callback(null, result + 1);
      }, 1000);
    },
    function (result, callback) {
      setTimeout(() => {
        console.log('Task 3, result from task 2:', result);
        callback(null, result + 1);
      }, 1000);
    }
  ], function (err, finalResult) {
    console.log('All tasks completed. Final result:', finalResult);
  });

Applying eachOf for Object Iteration

  const asynckit = require('asynckit');
  const tasks = {
    task1: 1,
    task2: 2,
    task3: 3,
    task4: 4
  };

  asynckit.eachOf(tasks, function (value, key, done) {
    setTimeout(() => {
      console.log('Processing', key, 'with value', value);
      done(null, value * 2);
    }, 1000);
  }, function (err, results) {
    console.log('All object tasks completed:', results);
  });

Comprehensive App Example

Let’s build a simple application that demonstrates the combined usage of Asynckit’s APIs.

  const asynckit = require('asynckit');

  const fetchData = function (done) {
    setTimeout(() => {
      console.log('Fetching data');
      done(null, [1, 2, 3, 4]);
    }, 1000);
  };

  const processData = function (data, done) {
    asynckit.parallel(data, function (item, callback) {
      setTimeout(() => {
        console.log('Processing item', item);
        callback(null, item * 2);
      }, 1000);
    }, done);
  };

  asynckit.waterfall([
    fetchData,
    processData
  ], function (err, finalResult) {
    console.log('App completed. Final processed data:', finalResult);
  });

In this example, we first fetch data using a simulated asynchronous call, then process the fetched data items in parallel, and finally log the processed results.

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