Express.js and WebAssembly

WebAssembly (Wasm) is a binary instruction format that allows high-performance execution of code on web browsers. This guide covers key concepts, examples, and best practices for integrating WebAssembly with Express.js applications.

Key Concepts of WebAssembly

• WebAssembly (Wasm): A binary instruction format for a stack-based virtual machine, designed for high-performance execution of code on web browsers.
• Modules: WebAssembly code is organized into modules that contain functions and data.
• Compilation: WebAssembly modules are compiled from languages like C, C++, and Rust.
• Integration: WebAssembly can be integrated with JavaScript to enhance performance-critical parts of web applications.

Setting Up the Project

Initialize a new Express.js project and set up a simple WebAssembly module:

// Initialize a new project
// npm init -y

// Install Express
// npm install express

// Create the project structure
// mkdir src wasm
// touch src/index.js wasm/add.c .gitignore

// .gitignore
node_modules

Creating a WebAssembly Module

Create a simple WebAssembly module in C:

Example: add.c

// wasm/add.c
int add(int a, int b) {
    return a + b;
}

Compiling the WebAssembly Module

Compile the C code to WebAssembly using Emscripten:

// Install Emscripten
// Follow the instructions at https://emscripten.org/docs/getting_started/downloads.html

// Compile add.c to WebAssembly
// emcc wasm/add.c -s WASM=1 -o src/add.js

Creating the Express Application

Create a simple Express application that uses the compiled WebAssembly module:

Example: index.js

// src/index.js
const express = require('express');
const app = express();
const port = 3000;

app.use(express.static('public'));

app.get('/', (req, res) => {
    res.sendFile(__dirname + '/index.html');
});

app.listen(port, () => {
    console.log(`Server running at http://localhost:${port}/`);
});

Creating the HTML and JavaScript

Create the HTML and JavaScript to load and use the WebAssembly module:

Example: index.html

// src/index.html



    
    
    


    
WebAssembly with Express.js
    
Result: