update readme

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Joe Ardent 2024-06-05 16:36:40 -07:00
parent c45b179de4
commit 8a31269f45
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@ -8,7 +8,7 @@ distributed actors. It has three dependencies:
- serde_json
- serde_repr
For a simple example, see the [gg-echo](https://git.kittencollective.com/nebkor/chatty-catties/src/branch/main/gg-echo/src/main.rs) program:
For a simple example, see the [echo](https://git.kittencollective.com/nebkor/nebkor-maelstrom/src/branch/main/examples/echo.rs) example:
``` rust
use nebkor_maelstrom::{Body, Message, Node, Runner};
@ -34,6 +34,23 @@ fn main() {
}
```
For a slightly more complicated example, check out the
[broadcast](https://git.kittencollective.com/nebkor/nebkor-maelstrom/src/branch/main/examples/broadcast.rs)
example, which passes the [single-node](https://fly.io/dist-sys/3a/) challenge, but utterly fails
even the friendliest (eg, no partitions or lag) multi-node challenge, so hopefully is not giving too
much away.
## Features
- no async
- minimal boilerplate
- working RPC calls (allowing the main thread to call out to other nodes and receive a reply while
already handling a message)
- proxies for the [Maelstrom KV
services](https://github.com/jepsen-io/maelstrom/blob/main/doc/services.md) that use the RPC
mechanism to provide `read`, `write`, and `cas` operations, and return
`Result<Option<serde_json::Value>, ErrorCode>`s to the caller
## How to use
Create a struct and implement `nebkor_maelstrom::Node` for it, which involves a single method,
@ -41,10 +58,10 @@ Create a struct and implement `nebkor_maelstrom::Node` for it, which involves a
`send`, `reply`, and `rpc`.
In your main function, instantiate that struct and pass that into `Runner::new()` to get a
Runner. The `run()` method takes an optional closure that will be run when the `init` Message is
Runner. The `run()` method takes an optional callback that will be run when the `init` Message is
received; see the
[broadcast](https://git.kittencollective.com/nebkor/chatty-catties/src/commit/af6d2c0b2720669f91a758c8c5755a146a914be4/gg-broadcast/src/main.rs#L10-L30)
program for an example of that, where it spawns a thread to send periodic messages to the node.
[broadcast](https://git.kittencollective.com/nebkor/nebkor-maelstrom/src/commit/c45b179de45ba7e03a884d6c7cdb4c1c2625ae20/examples/broadcast.rs#L8-L20)
example, where it spawns a thread from the callback to send periodic messages to the node.
## Design considerations
@ -54,8 +71,18 @@ you need to, without the ceremony of `Rc<Mutex<>>` and the like. Eschewing `asyn
order of magnitude fewer dependencies, and the entire workspace (crate and clients) can be compiled
in a couple seconds.
It also assumes that some things are infallible. For example, there's liberal `unwrap()`ing when
calling `send()` or `recv()` on MPSC channels, because those kinds of errors are not part of the
Maelstrom protocol; this crate is not a general-purpose network client crate for the real
world. Likewise `stdin` and `stdout` are always assumed to be available and reliable; those two
channels are the physical layer for connecting a node to the Maelstrom router, and failures there
are out of scope for Gossip Glomers.
A final consideration is understandability of the crate itself; you should not have a hard time
diving into its source from your IDE or browser.
## Acknowledgments
I straight-up stole the design of the IO/network system from
[Maelbreaker](https://github.com/rafibayer/maelbreaker/), which allowed me to get a working RPC
call. Thanks!
call. Thanks! And thanks to Nicole for nudging me to publish this.