README.md

marcotte-wasm

Create Layers of host-agnostic system functionality for your WebAssembly (Wasm) application.

(Currently supports Filesystem Layers)

Example Usage

Take this rust code:

use std::fs;

pub fn scale(ctx: &mut Context) -> Result<&mut Context, Box<dyn std::error::Error>> {
    let filename = "example.txt".to_string();

    // open()
    let mut file = File::open(&filename).expect("Unable to open file");

    let s = "\n\n\n We are interacting with a filesystem!!!\n\n\n";

    let bytes = s.as_bytes();

    // write()
    file.write(&bytes);

    // read()
    let contents = file.read_to_string()?;

    ctx.response().set_body(format!("\nfile: {} ", contents));

    Ok(ctx)
    // close()
}

This will not be able to run in Core Wasm, because it relies on underlying libc interfaces, and syscalls provided by a kernel. marcotte (aliased: mwasm) can create these layers in pure webassembly, and allow your program to run (mostly) as if it were compiled to a native platform.

Running mwasm open read write close --full Will generate everything this code needs to run, in a pure WebAssembly Environment.

How it works

This cli relies on wasm-vfs and wasm-libc to create the libc interface layer, and the "Syscall" functionality all within a consumable Wasm Component.

Installation

clone and cargo build --release and drop the generated binary in your /usr/bin (or, your preferred) directory.

Limitations

Many, as this is a work-in-progress, experimental tool, but notably:

• Networking Layers
• Size Limitations
• Complete Filesystem Abstractions

Please see the repo's issues for more information on these.