Yet another one Rust crate for implementing nodes for https://github.com/jepsen-io/maelstrom and solve https://fly.io/dist-sys/ challenges.
Maelstrom is a platform for learning distributed systems. It is build around Jepsen and Elle to ensure no properties are violated. With maelstrom you build nodes that form distributed system that can process different workloads.
```bash $ cargo build --examples $ maelstrom test -w echo --bin ./target/debug/examples/echo --node-count 1 --time-limit 10 --log-stderr ````
implementation:
```rust use asynctrait::asynctrait; use maelstrom::protocol::Message; use maelstrom::{Node, Result, Runtime}; use std::sync::Arc;
pub(crate) fn main() -> Result<()> { Runtime::init(try_main()) }
async fn trymain() -> Result<()> { let handler = Arc::new(Handler::default()); Runtime::new().withhandler(handler).run().await }
struct Handler {}
impl Node for Handler { async fn process(&self, runtime: Runtime, req: Message) -> Result<()> { if req.gettype() == "echo" { let echo = req.body.clone().withtype("echo_ok"); return runtime.reply(req, echo).await; }
done(runtime, message)
}
} ```
spec:
receiving
{
"src": "c1",
"dest": "n1",
"body": {
"type": "echo",
"msg_id": 1,
"echo": "Please echo 35"
}
}
send back the same msg with body.type == echo_ok.
{
"src": "n1",
"dest": "c1",
"body": {
"type": "echo_ok",
"msg_id": 1,
"in_reply_to": 1,
"echo": "Please echo 35"
}
}
```bash $ cargo build --examples $ RUST_LOG=debug maelstrom test -w broadcast --bin ./target/debug/examples/broadcast --node-count 2 --time-limit 20 --rate 10 --log-stderr ````
implementation:
```bash
impl Node for Handler {
async fn process(&self, runtime: Runtime, req: Message) -> Result<()> {
let msg: Result
return runtime.reply_ok(req).await;
}
Ok(Request::Topology { topology }) => {
let neighbours = topology.get(runtime.node_id()).unwrap();
self.inner.lock().unwrap().t = neighbours.clone();
info!("My neighbors are {:?}", neighbours);
return runtime.reply_ok(req).await;
}
_ => done(runtime, req),
}
}
} ```
```bash $ cargo build --examples $ RUSTLOG=debug ~/Projects/maelstrom/maelstrom test -w lin-kv --bin ./target/debug/examples/linkv --node-count 4 --concurrency 2n --time-limit 10 --rate 100 --log-stderr ````
implementation:
```rust
impl Node for Handler {
async fn process(&self, runtime: Runtime, req: Message) -> Result<()> {
let (ctx, handler) = Context::new();
let msg: Result
fn handler(runtime: Runtime) -> Handler { Handler { s: lin_kv(runtime) } } ```
bash
$ cargo build --examples
$ RUST_LOG=debug ~/Projects/maelstrom/maelstrom test -w g-set --bin ./target/debug/examples/g_set --node-count 2 --concurrency 2n --time-limit 20 --rate 10 --log-stderr
implementation:
```rust
impl Node for Handler {
async fn process(&self, runtime: Runtime, req: Message) -> Result<()> {
let msg: Result
```rust use asynctrait::asynctrait; use maelstrom::kv::{linkv, Storage, KV}; use maelstrom::protocol::Message; use maelstrom::{done, Node, Result, Runtime}; use tokiocontext::context::Context;
struct Handler { s: Storage, }
impl Node for Handler {
async fn process(&self, runtime: Runtime, req: Message) -> Result<()> {
let (ctx, handler) = Context::new();
let msg: Result
fn handler(runtime: Runtime) -> Handler { Handler { s: lin_kv(runtime) } } ```
```rust use asynctrait::asynctrait; use maelstrom::protocol::Message; use maelstrom::{Node, Result, Runtime}; use serde::{Deserialize, Serialize}; use std::sync::{Arc, Mutex};
struct Handler {}
impl Node for Handler { async fn process(&self, runtime: Runtime, req: Message) -> Result<()> { let (mut ctx, handler) = Context::withtimeout(Duration::from_secs(1));
// 1.
runtime.call_async(node, msg.clone());
// 2. put it into runtime.spawn(async move { ... }) if needed
let res: RPCResult = runtime.rpc(node, msg.clone()).await?;
let msg: Result<Message> = res.await;
// 3. put it into runtime.spawn(async move { ... }) if needed
let mut res: RPCResult = runtime.rpc(node, msg.clone()).await?;
let msg: Message = res.done_with(ctx).await?;
// 4. put it into runtime.spawn(async move { ... }) if needed
let msg = runtime.call(ctx, node, msg.clone()).await?;
// 5. async send variant
// spawn into tokio (instead of runtime) to not to wait
// until it is completed, as it will never be.
let (r0, h0) = (runtime.clone(), self.clone());
tokio::spawn(async move {
loop {
tokio::time::sleep(Duration::from_secs(5)).await;
debug!("emit replication signal");
let s = h0.s.lock().unwrap();
for n in r0.neighbours() {
let msg = Request::ReplicateFull { value: to_seq(&s) };
drop(r0.send_async(n, msg));
}
}
});
return runtime.reply_ok(req).await;
}
} ```
```rust use serde::{Deserialize, Serialize};
struct TopologyRequest {
topology: HashMap
// or
pub enum Message {
Topology {
topology: HashMap
```
```rust use asynctrait::asynctrait; use log::info; use maelstrom::protocol::Message; use maelstrom::{done, Node, Result, Runtime}; use serde::{Deserialize, Serialize}; use serde_json::Value; use std::sync::{Arc, Mutex};
struct Handler { /* ... */ }
impl Node for Handler { async fn process(&self, runtime: Runtime, req: Message) -> Result<()> { if req.gettype() == "echo" { let echo = req.body.clone().withtype("echo_ok"); return runtime.reply(req, echo).await; }
if req.get_type() == "echo" {
let echo = format!("Another echo {}", message.body.msg_id);
let msg = Value::Object(Map::from_iter([("echo".to_string(), Value::String(echo))]));
return runtime.reply(message, msg).await;
}
if req.get_type() == "echo" {
let err = maelstrom::Error::TemporarilyUnavailable {};
let body = ErrorMessageBody::from_error(err);
return runtime.reply(message, body).await;
}
if req.get_type() == "echo" {
let body = MessageBody::default().with_type("echo_ok").with_reply_to(req.body.msg_id);
// send: no response type auto-deduction and no reply_to
return runtime.send(message, body).await;
}
if req.get_type() == "echo" {
return runtime.reply(message, EchoResponse { echo: "blah".to_string() }).await;
}
if req.get_type() == "read" {
let data = self.inner.lock().unwrap().clone();
let msg = ReadResponse { messages: data };
return runtime.reply(req, msg).await;
}
if req.get_type() == "broadcast" {
let raw = Value::Object(req.body.extra.clone());
let mut msg = serde_json::from_value::<BroadcastRequest>(raw)?;
msg.typ = req.body.typ.clone();
return runtime.reply(req, msg).await;
}
if req.get_type() == "broadcast" {
let mut msg = serde_json::from_value::<BroadcastRequest>(req.body.raw())?;
msg.typ = req.body.typ.clone();
return runtime.reply(req, msg).await;
}
if req.get_type() == "broadcast" {
let mut msg = req.body.as_obj::<BroadcastRequest>()?;
msg.typ = req.body.typ.clone();
return runtime.reply(req, msg).await;
}
if req.get_type() == "topology" {
info!("new topology {:?}", req.body.extra.get("topology").unwrap());
return runtime.reply_ok(req).await;
}
done(runtime, message)
}
} ```
Because I am learning Rust and I liked Maelstrom and fly.io pretty much. I wanted to play with different aspects of the language and ecosystem and build an API that will be somewhat convenient and short. I am sorry for my ego.
Thanks Aphyr and guys a lot.