WebAssembly

WebAssembly (sometimes abbreviated Wasm) defines a portable binary-code format and a corresponding text format for executable programs and software interfaces for facilitating interactions between such programs and their host environment. WebAssembly

• Introduction to WebAssembly • rsms

Assembly languages in general consists of simple and atomic operations that the processor can follow. For example, let's consider the following add.c C code.

#include <stdio.h>

int add(int x, int y) { return x + y; }

int main() {
    printf("Hello World\n");
    printf("1 + 2 = %d \n", add(1, 2));
    return 0;
}

❯ gcc add.c
❯ ./a.out
Hello World
1 + 2 = 3

It is a very straightforward C code that returns the sum of the two integers provided as input. We can convert this C code into WebAssembly with a build tool called Emscripten. After running the following command, we can get the WASM version of the function int add(int x, int y).

emcc add.c -o index.html

We can now create a local server to test this example.

❯ npx serve .

   ┌───────────────────────────────────────────────────┐
   │                                                   │
   │   Serving!                                        │
   │                                                   │
   │   - Local:            http://localhost:3000       │
   │   - On Your Network:  http://192.168.8.100:3000   │
   │                                                   │
   │   Copied local address to clipboard!              │
   │                                                   │
   └───────────────────────────────────────────────────┘

And we can confirm that it is working as expected.

Interesting Implementations

• Satori
• paradust7/minetest-wasm: Experimental Minetest build for WebAssembly/Emscripten

SQLite Wasm in the browser backed by the Origin Private File System - Chrome Developers

• SQLite based on Web Assembly
• Binding a low-level sqlite3 API which is as close to the C one as feasible in terms of usage.
• A higher-level object-oriented API, more akin to sql. js and Node. Js-style implementations speak directly to the low-level API. This API must be used from the same thread as the low-level API.
• A Worker-based API that speaks to the previous APIs via Worker messages. This one is intended for use in the main thread, with the lower-level APIs installed in a Worker thread and talking to them via Worker messages.
• A Promise-based variant of the Worker API that entirely hides the cross-thread communication aspects from the user.
• Support persistent client-side storage using JavaScript APIs, including the Origin Private File System (OPFS).