rkyv VS tokio

And before you ask: This only provides partial zero-copy support in strings and byte arrays like serde. But it's not like rkyv which constructs validated references into the data.

Regarding JSON, what kind of other implementation do you have in mind? I've seen e.g. `rkyv` which looks really neat (https://github.com/rkyv/rkyv/issues/85). So far `serde_json` is providing a clean surface API but maybe there's best solution?

Thank you for your concern. I've done plenty of projects that go beyond a "Hello World" such as a GPU accelerated password cracker. I am starting soon a C++/Rust job. I already contributed to codebases I didn't write.

rkyv is awesome because it supports full zero-copy deserialization. You can serialize your HashMap to a file. Later you can directly use the HashMap from the file without creating and populating a new HashMap in memory (rkyv directly indexes into the raw bytes). For even faster access times you can even mmap the file.

I had the same problem when trying to deserialize a big struct with rkyv: see rkyv#277.

Any chance of working with zero-copy deserialization frameworks? like https://github.com/rkyv/rkyv or capnproto

Hi, you seem to know a bit about Sanakirja!

It stores 4kb blobs, right? Does Pijul first parses the data (copying it to other allocations), or uses the data as is? I mean, there are some libraries like cap'n'proto[0] and rkyv[1] that can directly use the file contents as an in-memory data structure, I was wondering if Pijul did anything like that.

I mean, is this btree page [2] stored exactly like this on disk, and does Pijul exploits that to avoid further copying data?

(I guess there's a trouble with compression there: to decompress you really need to write in another buffer)

Also, is the I/O done with something that prevent userspace copies like mmap or io_uring, or does it eventually calls read() to copy the data to its own buffer?

I want to build something like Sanakirja, but with those features, so I'm wondering if there's any overlap.

[0] https://github.com/capnproto/capnproto-rust

[1] https://github.com/rkyv/rkyv

[2] https://docs.rs/sanakirja-core/latest/sanakirja_core/btree/p...

I think https://github.com/rkyv/rkyv does this. Also capnproto like was mentioned here, and perhaps https://docs.rs/zerocopy/0.6.1/zerocopy/index.html too

It's been two months since the last major rkyv release, and three months since the last major feature release. After all that time, I'm proud to announce that rkyv 0.7 is finally out!

After roughly two months of work, rkyv 0.5 is finally out!

Being able to control nondeterminism is particularly useful for testing and debugging. This allows creating reproducible test environments, as well as discrete-event simulation for faster-than-real-time simulation of time delays. For example, Cardano uses a simulation environment for the IO monad that closely follows core Haskell packages; Sui has a simulator based on madsim that provides an API-compatible replacement for the Tokio runtime and intercepts various POSIX API calls in order to enforce determinism. Both allow running the same code in production as in the simulator for testing.

tokio / hyper / toml / serde / serde_json / json5 / console

tokio - An asynchronous runtime for Rust

3. Tokio

The AWS SDK makes use of the async capabilities in the Tokio library. So when you see async in front of a fn that function is capable of executing asynchronously.

Petar is also looking at implementing concurrency the way it is in Go to have a fully functional virtual machine as it is in the spec. This would likely attract more external contributors to developing the VM. One advantage of Rust is that, with the concurrency model, there is already an extensive library called Tokio which he can use. Petar stresses that this isn’t easy, but he believes it’s achievable, at least as a research topic around determinism and concurrency.

Another thing to point out is that async is a thing in Rust. I'm not going to begin to dive into this paradigm in this article, but know it's handled by the awesome Tokio framework.

So I started by using Tokio, a popular async runtime. The docs and samples helped me get a simple outbound TCP connection working. The Rust async book also had a lot of good explanations, both practical and digging into the details of what a runtime does.

Regarding the quote:

> The Original Sin of Rust async programming is making it multi-threaded by default. If premature optimization is the root of all evil, this is the mother of all premature optimizations, and it curses all your code with the unholy Send + 'static, or worse yet Send + Sync + 'static, which just kills all the joy of actually writing Rust.

Agree about the melodramatic tone. I also don't think removing the Send + Sync really makes that big a difference. It's the 'static that bothers me the most. I want scoped concurrency. Something like <https://github.com/tokio-rs/tokio/issues/2596>.

Another thing I really hate about Rust async right now is the poor instrumentation. I'm having a production problem at work right now in which some tasks just get stuck. I wish I could do the equivalent of `gdb; thread apply all bt`. Looking forward to <https://github.com/tokio-rs/tokio/issues/5638> landing at least. It exists right now but is experimental and in my experience sometimes panics. I'm actually writing a PR today to at least use the experimental version on SIGTERM to see what's going on, on the theory that if it crashes oh well, we're shutting down anyway.

Neither of these complaints would be addressed by taking away work stealing. In fact, I could keep doing down my list, and taking away work stealing wouldn't really help with much of anything.

The PHP <-> Rust bindings are provided by https://github.com/Nicelocal/ext-php-rs/ (our fork of https://github.com/davidcole1340/ext-php-rs with a bunch of UX improvements :).

php-tokio's integrates the https://revolt.run event loop with the https://tokio.rs event loop; async functionality is provided by the two event loops, in combination with PHP fibers through revolt's suspension API (I could've directly used the PHP Fiber API to provide coroutine suspension, but it was a tad easier with revolt's suspension API (https://revolt.run/fibers), since it also handles the base case of suspension in the main fiber).