olahol / spawn.js

Tiny javascript library for spinning up one off web workers.

spawn.js

A tiny javascript library for spinning up one off web workers.

Examples

Hello world:

spawn(function (done) {
  done(null, "Hello world!")
}, function (err, msg) {
  console.log(msg);
});

Calculate a sequence of the first 100000 fibonacci numbers:

var fib = function (n, done) {
  var fibs = [0,1];

  for (var i = 0; i < n - 2; i++) {
    fibs.push(fibs.slice(-1)[0] + fibs.slice(-2, -1)[0]);
  }

  done(null, fibs);
};

var start = new Date()
  , n = 1000000;

spawn(fib, n, function (err, result) {
  if (err) { return console.log(err); }

  var ms = (new Date()).getTime() - start.getTime();
  console.log("took", ms, "ms to calculate a", result.length
              , "long fibonacci sequence");
});

Documentation

spawn(fn, [args..], cb)

Create a one off web worker with function fn passing in an optional number of arguments args. The last argument to fn is a callback done which takes as its first argument an error. cb is called when done is called from the web worker, done also terminates the web worker. Errors thrown in the web worker are captured in the first parameter to cb.