BrowserFS

I think JupyterLite is using localStorage by default. But there are File System APIs for WASM and some external projects[0], I don't think they're yet integrated. [0] https://github.com/jvilk/BrowserFS

it uses the [0]File System API of emscripten. i think it is possible to pipe via stdin somehow but i have no experience with any of this stuff but am interested to do something similar myself. although i don't want to transcode but repackage input streams for browser consumption. I also found [1]this which implements various filesystem backends in a compatible way afaict although the XHR backend [2]requires some index file i would like to avoid and its also not clear to me if this will actually stream data and/or use range requests. [0] https://emscripten.org/docs/api_reference/Filesystem-API.htm... [1] https://github.com/jvilk/BrowserFS [2] https://github.com/jvilk/BrowserFS/blob/a96aa2d417995dac7d37...

I vaguely recall something like that, a virtual file system using browser local storage. A search yields: > BrowserFS is an in-browser file system that emulates the Node JS file system API and supports storing and retrieving files from various backends. https://github.com/jvilk/BrowserFS It supports storage backends such as: in memory, LocalStorage, IndexDB, HTTP, or the FileSystem API.

BrowserFS has a few different APIs integrated. Not the lightest library though. https://github.com/jvilk/BrowserFS/blob/master/README.md

You're right; when it is running in the browser, isomorphic-git does not have access to the operating system's file system. Instead, it uses BrowserFS [1], which emulates a file system abstraction on top of arbitrary storage backends. It supports IndexedDB, localStorage, and Dropbox, among others. (Disclaimer: I am the author of BrowserFS.) [1] https://github.com/jvilk/BrowserFS

There is BrowserFS https://github.com/jvilk/BrowserFS

I'm a huge fan of the work here & strongly strongly believe in file-system oriented architectures. Being able to use a wide number of existing "server side" libraries in the browser could be a huge win. And this has interesting server side applications too, where one can use the same Node.js code but target diverse & interesting backends & overlayed systems. Having a virtual-fs is an incredibly powerful and useful concept. "Everything is a file!" still sounds like a great idea. Alas BrowserFS lacks Streams support. Given how async oriented and streams based a lot of new JS tends to be, that is a huge sticking point for me, and a glaring exception that will rule out using a very sizable number of existing packages that otherwise would benefit greatly from BrowserFS. Issue 124, Support streams: https://github.com/jvilk/BrowserFS/issues/124

Doppio (https://github.com/plasma-umass/doppio) is exactly this: a POSIX layer (for a single process), while Browsix is a Unix layer. Both are JS only. Doppio implements a ton of libc functionality, enough to host a full JVM interpreter (see http://plasma-umass.github.io/doppio-demo/). Doppio contains BrowserFS (available separately as https://github.com/jvilk/BrowserFS), an in-browser file system that abstracts over local storage and lets you mount remote filesystems like Dropbox, Zip files, and more. Archive.org is using it for all of its DOS and Windows games.

Haha, I've actually tried to do this. The only missing link, I believe, is to add a Nashorn/Rhino backend to BrowserFS (Doppio's file system library) so that Doppio can access the filesystem that Rhino is running in to load the JDK. If that sounds like fun, I take pull requests [0]. :) [0] https://github.com/jvilk/browserfs

Yeah, Doppio needs to download the entire JDK to run, since it's a full-featured JVM (JRE for running Java programs, JDK for javac so it can compile them). Compressed, it's ~30MB. The authors of this project can preload the JDK with a progress bar and stash it into IndexedDB, since Doppio's file system, BrowserFS, supports arbitrary backends [1]. [1] https://github.com/jvilk/browserfs

I actually embarked on a similar Python VM called Ninia [1] awhile back, but shelved it as other projects became more important. Ninia supports multiple threads and preempts execution to give the browser breathing space, just like my JVM in JavaScript, DoppioJVM [2]. One of the challenges of Python is its objects are quite complex/ad-hoc, and can be overridden by the user. I mapped out [3] how I wanted to map Python objects to JavaScript objects, but never had the time to implement it fully. (That document covers Python 2.7; I'm sure there are differences for 3.) It looks like this project has a lot of work to do if it wants to have parity with a native Python VM! But that's part of the fun of writing these things. Best of luck on the VM! If you need a file system to plug into the VM for loading modules/implementing the FS API, do check o

I think your work is amazing and you should link to it: https://github.com/jvilk/BrowserFS