Move prime calculation to web worker.

This commit moves the calculation to a web worker,
so that way it can be handled asynchronously so the web app
can move on and not block.

Author: coderkevin

examples/simple/middleware/primesMiddleware.js

@@ -4,6 +4,7 @@ export const CHECK_NEXT_PRIME = 'CHECK_NEXT_PRIME';
 
 function createPrimesMiddleware() {
 	return ( store ) => ( next ) => ( action ) => {
+
 		switch ( action.type ) {
 			case CHECK_NEXT_PRIME:
 				const { queue } = store.getState().primeState;
@@ -35,18 +36,22 @@ function checkNextPrime( queue, dispatch ) {
 }
 
 function checkPrime( number ) {
+
 	return new Promise(
 		( resolve, reject ) => {
+			// Create a worker to do the actual mathematical operations.
+			const worker = new Worker( '/static/worker-primes.js' );
 
-			for ( let i = 2; i < number; i++ ) {
-				if ( Number.isInteger( number / i ) ) {
-					console.log( number + " is divisible by " + i );
-					resolve( false );
-				}
+			worker.onmessage = function( evt ) {
+				console.log( 'message received from worker.' );
+				console.log( evt );
+				resolve( evt.data );
 			}
 
-			// No numbers below this one divided cleanly, it's prime.
-			resolve( true );
+			console.log( 'Worker created' );
+			console.log( worker );
+
+			worker.postMessage( Number( number ) );
 		}
 	);
 }

examples/simple/webpack.config.js

@@ -3,13 +3,14 @@ var webpack = require( 'webpack' );
 
 module.exports = {
 	devtool: 'cheap-module-source-map',
-	entry: [
-		'webpack-hot-middleware/client',
-		'./index.jsx'
-	],
+	entry: {
+		'hot-middleware': 'webpack-hot-middleware/client',
+		'bundle': './index.jsx',
+		'worker-primes': './workers/worker-primes.js'
+	},
 	output: {
 		path: path.join( __dirname, 'dist' ),
-		filename: 'bundle.js',
+		filename: '[name].js',
 		publicPath: '/static/'
 	},
 	plugins: [

examples/simple/workers/worker-primes.js

@@ -0,0 +1,26 @@
+
+console.log( 'worker script executed.' );
+
+addEventListener( 'message', function( evt ) {
+	const number = evt.data;
+	console.log( 'Checking number' + number );
+
+	postMessage( isPrime( number ) );
+
+	// Our work here is done.
+	close();
+} );
+
+function isPrime( number ) {
+	for ( let i = 2; i < number; i++ ) {
+		if ( Number.isInteger( number / i ) ) {
+			console.log( number + ' is divisible by ' + i );
+			return false;
+		}
+	}
+
+	// No numbers below this one divided cleanly, it's prime.
+	console.log( number + ' is prime.' );
+	return true;
+}
+