diamond-types VS meetings

> I think far more interesting these days would be projects like Veilid, Hyphanet's Locutus

I have not assessed Veilid yet but it's on my list and at a first glance seems like a very serious and informed attempt. I'm personal friends with Freenet / Hyphanet's Ian Clarke and spoke with him about Locutus when he was just getting started. It sounded awesome then and I will give this a second look too, though when he explained it to me it sounded like it had the same limitations with deletion that Nostr or the global IPFS network would have. It does seem important to note here that both Veilid and Locutus are much less mature and battle-tested than libp2p and Tor and have less Lindy longevity (longevity as a function of age.) We already suffer a lot from being on the bleeding edge, so it's nice to limit the number of bleeding edge tools we use. Libp2p, notably, has been rock solid for us and barely a time drain at all, apart from some unexpected interactions with Tor which are mostly about the lack of an official first-class Tor transport, which is specific to our use case and should start to change soon when Tor's Arti is ready.

> and ultimately Nostr -- even though not truly P2P in that sense -- which already happens to have a first try going with nostrchat.io.

Nostr and Bluesky both seem very promising for the open-world use case of social networking, and it has been amazing to see Nostr grow so rapidly as a community. I am rooting for this project and we might use it someday in Quiet for public feeds. Timed deletion is the user requirement that drives me away from building Quiet on Nostr. Based on conversations I've had with users doing sensitive work (and based on my own experience as a founder of Fight for the Future) timed deletion is extremely important to team security, and for deletion to be meaningful one needs more control over where the data is relayed than what Nostr provides in the default mode. A group that wanted trustworthy timed deletion would have to control their own private Nostr relay. Technically, a Tor relay could subvert the timed deletion of some Quiet messages just by capturing all traffic, but this is much less of a worry.

> If P2P is something that is truly desired, I feel like projects like Briar (https://briarproject.org/how-it-works/) have solved this with Bramble (https://code.briarproject.org/briar/briar-spec/blob/master/p...) more eloquently than it could be done on top of IPFS.

Bramble could work for us and I would recommend that anyone look into it. Briar is probably the most similar thing to Quiet that exists right now. There are big differences between Quiet and Briar, but we could definitely build Quiet on Bramble if it adequately supports iOS. My worry would be its maturity as a tool for people building things other than Briar. That could be worth the risk though and I do recommend anyone else reading this thread look at Bramble if you are doing something similar.

> I could nevertheless imagine it being overtaken fairly quickly by other projects sporting a rather lightweight and more managable basis, that allows for increased development speed and ultimately for faster iteration on features that users might wish for (e.g. DMs, @-mentions, message deletion, mobile clients, you-name-it) -- without the need to invest heavily into e.g. performance (or reliability!) issues of the underlying framework.

This is definitely something we will keep an eye on, and thank you for the thoughtful advice! My guess is that as soon as we have a significant number of real users we will need to build things that don't happen to be supported by whatever stack we choose (whether that is our current stack, Bramble, Veilid, Automerge, etc.) So the question is what's the easiest one to maintain and adapt. So far libp2p and IPFS have both been good in that department: implementations in many languages, active development, an absence of major problems showing signs of maturity (especially in libp2p), etc.

Also, my 2 cents are (for anyone following along) that if I had to do this all over again I would use Tor + Libp2p + Automerge. Libp2p and Gossipsub are solid, flexible, and will be around a while. No need to reinvent the wheel. The conceptual framework behind Automerge and Briar/Bramble are pretty similar (sync state!) but the Automerge team exists to serve people building other apps, while the Bramble team mostly focuses on Briar AFAIK. What's nice about Automerge is that the community around it (Ink & Switch, Martin Kleppmann, and other academics) is all at the academic frontier, so the level of thought and anticipation of user needs that goes into their decisions is very thorough, even if the implementations lag behind the papers. If I was doing real-time text I would also look at the Briar project and Seph Gentle's work on Diamond Types, since that's where the most thought has gone into the raw performance you need for text CRDTs that can handle large documents: https://github.com/josephg/diamond-types

But I think thats about it. Maybe there's more manually specified types in "normal" rust because most functions are smaller than that. But, it doesn't feel so bad. In this case I could probably even remove the explicit type annotation for that queue definition if I wanted to, but it makes the compiler's errors better leaving it in.

[1] https://github.com/josephg/diamond-types/blob/66025b99dbe390...

diamond-types (for reference for others [0]) still only supports plain text, is that right? I was thinking of using it for more general use cases such as an offline habit tracker, which isn't text of course, but I was interested to hear more on the progress towards other data types such as generic JSON data.

Currently for this use case I've been using autosurgeon [1] so far which has a nice Rust API for structs, even if it might be slower than yjs (or yrs, its Rust implementation) or diamond-types.

[0] https://github.com/josephg/diamond-types

[1] https://github.com/automerge/autosurgeon

I'm working on a CRDT to solve this problem too[1]. How do you plan on implementing collaborative text editing on top of your event-reordering system? Off the top of my head I can't think of a way to implement text on your proposed system which would be performant and simple.

[1] https://github.com/josephg/diamond-types

For example, this file implements a complex iterator via a struct and really complex next() method. This file was about 1/3rd the size before I manually rewrote it into a "continuation passing" style. I find it significantly harder to read and maintain in its current form.

> In this case, the bottleneck at 9 million LoC is not CPU cycles but memory usage. That's where I am considering pushing down into WebAssembly

How often does this come up in practice? I can't think of many files I've opened which were 9 million lines long. And you say "LoC" (lines of code). Are you doing syntax highlighting on 9 million lines of source code in javascript? Thats impressive!

> I guess my point is why do you need balanced trees? Is this a CRDT specific thing? Can you implement CRDT with just an array of lines / gap buffer?

Of course! Its just going to be slower. I made a simple reference implementation of Yjs, Automerge and Sync9's list types in javascript here[1]. This code is not optimized, and it takes 30 seconds to process an editing trace that diamond types (in native rust) takes 0.01 seconds to process. We could speed that up - yjs does the same thing in 1 second. But I don't think javascript will ever run as fast as optimized rust code.

The b-tree in diamond types is used for merging. If you're merging 2 branches, we need to map insert locations from the incoming branch into positions in the target (merged) branch. As items are inserted, the mapping changes dynamically. The benchmark I've been using for this is how long it takes to replay (and re-merge) all the changes in the most edited file in the nodejs git repository. That file has just shy of 1M single character insert / delete operations. If you're curious, the causal graph of changes looks like this[2].

Currently it takes 250ms to re-merge the entire causal graph. This is much slower than I'd like, but we can cache the merged positions in about 4kb on disk or something so we only need to do it once. I also want to replace the b-tree with a skip list. I think that'll make the code faster and smaller.

A gap buffer in javascript might work ok... if you're keen, I'd love to see that benchmark. The code to port is here: [3]

> Undo support -> In which case, you only have to stack / remember the set of commands and not have to store the state on every change. I'm not sure if this overlaps with the data structure choice, other than implementation details.

Yeah, I basically never store a snapshot of the state. Not on every change. Not really at all. Everything involves sending around patches. But you can't just roll back the changes when you undo.

Eg: I type "aaa" at position 0 (the start of the document). You type "bbb" at the start of the document. The document is now "bbbaaa". I hit undo. What should happen? Surely, we delete the "aaa" - now at position 3.

Translating from position 0 to position 3 is essentially the same algorithm we need to run in order to merge.

> I was just looking into TypedArrays.

I tried optimizing a physics library a few years ago by putting everything in typedarrays and it was weirdly slower than using raw javascript arrays. I have no idea why - but maybe thats fixed now.

TypedArrays are useful, but they're no panacea. You could probably write a custom b-tree on top of a typedarray in javascript if you really want to - assuming your data also fits into typedarrays. But at that point you may as well just use wasm. It'll be way faster and more ergonomic.

[1] https://github.com/josephg/reference-crdts

[2] https://home.seph.codes/public/node_graph.svg

[3] https://github.com/josephg/diamond-types/tree/master/src/lis...

Hi everyone! Author here. I'm happy to answer questions.

I wrote this a couple years ago. Since then I've been working on my own CRDT called Diamond Types[1], which uses a lot of these ideas to be bonkers fast. I've built several OT based collaborative editing systems, and diamond types is much faster than any of them - though rust and wasm might be the real MVPs here. I wrote a follow-up to this article last year when I got that working, talking about how some of the optimizations work. That article is here[2].

A fair bit has changed since I wrote that article. Yjs has started a rewrite in rust (called yrs[3]). And Automerge has apparently dramatically improved performance based on some of the ideas I talk about in this article. Oh, and diamond types has been rewritten from the ground up. Its now about 5x faster than it was last year, by completely changing the internal structure. But thats a story for another day.

Unfortunately I still only support collaborative text editing. Adding full JSON support comes soon, after I document some more of the tricks I'm doing. Its really fun work!

Why do I only support collaborative text editing? Because I care about performance, and text CRDT performance is hard because you have so many individual changes. (One for each keystroke!). Making text editing fast means everything is fast. But we've still got to do the work. To make that happen, my plan is to add full JSON editing support to diamond types using shelf[4]. Shelf is a super simple CRDT which fits in 100 lines of javascript.

[1] https://github.com/josephg/diamond-types/

[2] https://josephg.com/blog/crdts-go-brrr/

[3] https://github.com/y-crdt/y-crdt/tree/main/yrs

[4] https://github.com/dglittle/shelf

Yep. I've done something very similar on top of Diamond Types for a little personal wiki. This page[1] is synced between all users who have the page open. Its a remarkably small piece of code, outside of the CRDT library itself (which is in rust via wasm). The way it works is:

- On page load, the server sends the whole CRDT document to the browser, and the server streams changes from that point onwards.

- When a change happens in the browser, it makes that change locally then and sends anything the server doesn't know about upstream.

- Whenever the server finds out about a new change, it re-broadcasts that change to any subscribed browser streams.

I'm using the braid HTTP protocol for changes - but we could easily switch to a SSE or websocket solution. It doesn't really matter.

At the moment I'm just using flat files for storage, but there's nothing stopping you using a database instead, except that its a bit awkward to use efficient CRDT packing techniques in a database.

[1] https://wiki.seph.codes/hn

Code is here, if anyone is interested. The whole thing is a few hundred lines all up: https://github.com/josephg/diamond-types/tree/0cb5d7ecf49364...

With each change we just send the missing operations. Https://wiki.seph.codes/reddit if you want to mess around and see it in action via wasm. The code which runs this wiki is here.

Another way to trace allocations in rust is to inject some code in a global allocator. Then you can use any in-program code you like to print / track / trace allocations. For example, I wrote this code in a library I’m working on so I can track and print out how many total bytes have been allocated, and how many allocation calls have been made.

WASI Co-chair here. Nothing in WASI is "somehow blocked by Google", or indeed blocked by anyone at all. Graphics support in WASI hasn't been developed simply because nobody has put energy into developing graphics support in WASI.

At the end of 2023 we counted around 40 contributors who have been working on WASI specifications and implementations: https://github.com/WebAssembly/meetings/blob/main/wasi/2023/... . That is a great growth for our project from a few years ago when that issue was filed, but as you can see from what people are working on, its all much more foundational pieces than a graphics interface. Also, if you look at who is employing those contributors, its largely vendors who are interested in WASI in the context of serverless. That doesn't mean WASI is limited to only serverless, but that has been the focus from contributors so far.

By rolling out WASI on top of the WASM Component Model we have built a sound foundation for creating WASI proposals that support more problem domains, such as embedded systems (@mc_woods and his colleagues are helping with this), or graphics if someone is interested in putting in the work. Our guide to how to create proposals is found here: https://github.com/WebAssembly/WASI/blob/main/Contributing.m... .

For me, the huge missing link (that is fortunately being worked on!) is being able to (in a performant way) have a good answer for "host code wants to do some blocking operation, WASM should suspend during the operation".

This _should_ be gotten thanks to work on stack switching in WASM. As of the most recent working group meeting on this [0], it seems like V8 has made a good amount of progress on this. They published a thing back in January[1] on this, and hopefully if things go well and this is available across WASM engines then there will be one less "JS-ism" (everything async) that causes issues for transpilation.

[0]: https://github.com/WebAssembly/meetings/blob/main/stack/2023...

[1]: https://v8.dev/blog/jspi

> Whereas the later has only been around since 2015 and was created by a company that subsists off an agreement with a deviant online advertising company.

Mozilla created a precursor technology, but I thought Wasm was developed via the W3C standards process from the start. From the notes of the first meeting, you can see attendees from Adobe, Apple, ARM, Autodesk, Google, Intel, Mozilla, Stanford, and more.

https://github.com/WebAssembly/meetings/blob/main/main/2017/...

Additionally, Wasm has been a W3C standard since 2019.

A bunch of packages like tokio don't work because they transitively depend on net, and WASI doesn't have networking yet (networking is in phase 1 of 5), and it doesn't seem possible to turn off the net feature of transitive dependencies

I think SIMD was a distraction to our conversation, most code doesn't use it and in the future the length agnostic, flexible vectors; https://github.com/WebAssembly/flexible-vectors/blob/master/... are a better solution. They are a lot like RVV; https://github.com/riscv/riscv-v-spec, research around vector processing is why RISC-V exists in the first place!

I was trying to find the smallest Rust Wasm interpreters I could find, I should have read the source first, I only really use wasmtime, but this one looks very interesting, zero deps, zero unsafe.

16.5kloc of Rust https://github.com/rhysd/wain

The most complete wasm env for small devices is wasm3

20kloc of C https://github.com/wasm3/wasm3

I get what you are saying as to be so small that there isn't a place of bugs to hide.

> “There are two ways of constructing a software design: One way is to make it so simple that there are obviously no deficiencies, and the other way is to make it so complicated that there are no obvious deficiencies. The first method is far more difficult.” CAR Hoare

Even a 100 line program can't be guaranteed to be free of bugs. These programs need embedded tests to ensure that the layer below them is functioning as intended. They cannot and should not run open loop. Speaking of 300+ reimplementations, I am sure that RISC-V has already exceeded that. The smallest readable implementation is like 200 lines of code; https://github.com/BrunoLevy/learn-fpga/blob/master/FemtoRV/...

I don't think Wasm suffers from the base extension issue you bring up. It will get larger, but 1.0 has the right algebraic properties to be useful forever. Wasm does require an environment, for archival purposes that environment should be written in Wasm, with api for instantiating more envs passed into the first env. There are two solutions to the Wasm generating and calling Wasm problem. First would be a trampoline, where one returns Wasm from the first Wasm program which is then re-instantiated by the outer env. The other would be to pass in the api to create new Wasm envs over existing memory buffers.

See, https://copy.sh/v86/

MS-DOS, NES or C64 are useful for archival purposes because they are dead, frozen in time along with a large corpus of software. But there is a ton of complexity in implementing those systems with enough fidelity to run software.

Lua, Typed Assembly; https://en.wikipedia.org/wiki/Typed_assembly_language and Sector Lisp; https://github.com/jart/sectorlisp seem to have the right minimalism and compactness for archival purposes. Maybe it is sectorlisp+rv32+wasm.

If there are directions you would like Wasm to go, I really recommend attending the Wasm CG meetings.

https://github.com/WebAssembly/meetings

When it comes to an archival system, I'd like it to be able to run anything from an era, not just specially crafted binaries. I think Wasm meets that goal.

https://gist.github.com/dabeaz/7d8838b54dba5006c58a40fc28da9...

[2]: https://github.com/WebAssembly/meetings/blob/main/process/ph...

The simplest way to get involved is to start attending the biweekly standardization meetings. The agendas are organized here: https://github.com/WebAssembly/meetings

To attend the meetings, first join the W3C WebAssembly Community Group here: https://www.w3.org/groups/cg/webassembly, then email the CG chairs at [email protected] to ask for an invite.

From there you'll get a sense of who folks are so you can pair names with faces when contributing to the various proposal discussions on the many proposal repos listed here: https://github.com/webassembly/proposals.

To get a sense of how things are run and decided, read the process documents here: https://github.com/WebAssembly/meetings/tree/main/process. The TL;DR is that the community group and its subgroups decide everything by consensus via votes during the meetings.

Meetings are scheduled here, along with their planned agendas: https://github.com/WebAssembly/meetings/tree/master/stack/20...