actix VS libpnet

9. Actix

I think it's fairer to say the language got so much more powerful that there wasn't any point making actors a language feature when they can be built from existing orthogonal language features. You're probably looking for actix (not actix-web, just actix). There's also Lunatic built in Rust but supporting any actors compiled to WebAssembly.

Actix is an actor framework for developing concurrent applications built on top of the Tokio asynchronous runtime. It allows multiple actors to run on a single thread, but also allows actors to run on multiple threads via Arbiters. Actors can communicate with each other by sequentially exchanging typed messages.

I’ve seen frameworks for c++ (https://seastar.io/) and rust (https://github.com/actix/actix) which support what you’re describing out of the box.

The actix repository on github doesn't seem to be very active, and everyone seems to be focused on actix-web instead, is anyone out there using plain actix or any other actor-model implementation in Rust?

Rust is also another possibility: it's basically C++ but more modern with added features and safety. It can be tricky to write mathematical stuff in it, because you may not care too much about all the safety concerns Rust forces you to handle, but it can be useful to catch bugs ahead of times. Sadly, Rust seems to have no library for running programs on clusters of PCs, except maybe this one, which takes the Actor model implemented by Actix and runs it on a cluster. I don't know how tricky it is to use the Actor model for a scientific simulation, tho.

I'd just use Actix for that. Make your state an actor and make it a StreamHandler for each of these sources, and that's it - now you just implement the business logic for handling each message in the StreamHandler::handle methods.

However, this isn't even 50% of what's out there: Need raw parallel power (and maybe don't need an async runtime)? Checkout Rayon. Need simple Actors for concurrent processing? Checkout Actix. Need a larger Actor system for fault tolerance/CQRS messaging? Checkout Riker. Damn, I sound like a youtube advert 🤦 - For real though, this is the tip of the concurrency iceberg. There is so much more - and it's growing.

Hey, I'm looking for the best way to do packet capture in Rust. I've looked at both libpnet and pcap crates, and they both seem way less mature and with less functionality than the PcapPlusPlus library, which seems to be the golden suite of packet capture and manipulation.

> I mentioned really briefly that tcpdump lets you save pcap files. This is awesome because literally every network analysis tool in the universe understands pcap files. pcap files are like freshly baked chocolate chip cookies. Everybody loves them.

OMG, yes, very well put. When I get a bug report with a pcap file I know I'll be able to know exactly what happened.

Speaking of which: for one of my libraries, I want to make a diagnostic tool that replays an interaction. My library mostly operates at the TCP level (also some UDP), so I need to reconstruct the TCP flows in my tool to feed to my library. Either I need an easy-to-use Rust library to do that directly from pcap files [1] or some format that represents bytes moving over the flow (like sets of lines with a timestamp, flow id, and pretty hexdump of the bytes) with a tool that produces it from pcap. This seems like something that should exist? Wireshark's “Analyze > Follow > TCP Stream”’s “Save As…” with "hex dump" is kind of what I want, but it doesn't have timestamps, and it doesn't have a way to put everything (multiple flows, UDP packets also) in one file.

[1] https://crates.io/crates/pnet looks promising but it wasn't as obvious as I hoped how to plug it in for what I want.

libpnet provides a cross-platform API for low level networking using Rust.