A really simple way to move a function or class to a web worker. πŸ‹οΈβ€β™€οΈβ†’ πŸ˜„
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dist raw+umd build Mar 16, 2018
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README.md

Workly πŸ‹οΈβ€β™€οΈβ†’ πŸ˜„

  • A really simple way to move a stand-alone function/class to a worker thread.
  • Or, expose an object or function in a worker to the main thread.
  • All calls are made asynchronous. Works great with async/await.
  • Only 1.01kB gzipped.

Install

Download the latest from dist folder

or from npm:

npm install --save workly

Usage

Moving a function to a worker is really simple.

function busyAdd(a, b) {
  let st = Date.now();
  while (true) {
    if ((Date.now() - st) > 2000) break;
  }
  return a + b;
}

(async () => {
  let workerAdd = workly.proxy(busyAdd);
  console.log(await workerAdd(23, 16)); // 39
  // the busyAdd is executed in a worker so
  // the UI does not get blocked
})();

Or, in fact a Class

class Adder {
  constructor() {
    this.count = 0;
  }
  add(a, b) {
    this.count++;
    return a + b;
  }
}

(async () => {
  let WAdder = workly.proxy(Adder);
  let a = await new WAdder(); // instance created/running in worker
  console.log(await a.count); // 0
  console.log(await a.add(23, 16)); // 39
  console.log(await a.count); // 1
})();

Custom workers

The above examples only work when the class/function is not dependent on the containing scope, i.e. other libraries or global objects. But, you can create a custom worker.js file and move the code in there. In the worker, you can expose your object/function/class using workly.expose method.

In this example, the function depends on moment.js

worker.js

importScripts('https://cdn.jsdelivr.net/npm/moment@2.20.1/moment.min.js', '../dist/workly.min.js');
function friendlyTime(value) {
  return moment(value).calendar(null, {
    sameDay: function (now) {
      if (now - this < 1000 * 60) {
        return "[Just now]";
      } else if (now - this < 1000 * 60 * 60) {
        return "[" + Math.round((now - this) / (1000 * 60)) + " mins ago]";
      } else {
        return '[Today at] LT'
      }
    }
  });
}
workly.expose(friendlyTime);

main.js

(async () => {
  let w = workly.proxy("./worker.js");
  let now = Date.now();
  console.log(now);
  console.log(await w(now));
  console.log(await w(now - (24 * 60 * 60 * 1000)));
  console.log(await w(now - (4 * 24 * 60 * 60 * 1000)));
})();

Caveats

  • If you're not using a custom worker, the function/class being pushed to the worker cannot depend on the containing scope.
  • Since workers do not have access to DOM, DOM manipulation is not supported.
  • Objects passed into functions are not passed by reference, so if the function in the worker updates the passed in object, it will not affect the object in the main scope.

Examples

See the examples folder

License

MIT License (c) Preet Shihn

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