Cargo.lock

@@ -36,15 +36,6 @@ dependencies = [
  "serde_json",
 ]
 
-[[package]]
-name = "gg-g_counter"
-version = "0.0.1"
-dependencies = [
- "nebkor-maelstrom",
- "rand",
- "serde_json",
-]
-
 [[package]]
 name = "gg-uid"
 version = "0.0.1"

Cargo.toml

@@ -1,5 +1,5 @@
 [workspace]
-members = ["gg-echo", "gg-uid", "gg-broadcast", "nebkor-maelstrom", "gg-g_counter"]
+members = ["gg-echo", "gg-uid", "gg-broadcast", "nebkor-maelstrom"]
 resolver = "2"
 
 [workspace.package]
@@ -9,5 +9,3 @@ license-file = "LICENSE.md"
 
 [workspace.dependencies]
 serde_json = "1"
-rand = "0.8"
-

gg-broadcast/Cargo.toml

@@ -8,4 +8,4 @@ license-file.workspace = true
 [dependencies]
 serde_json.workspace = true
 nebkor-maelstrom = { path = "../nebkor-maelstrom" }
-rand.workspace = true
+rand = "0.8.5"

gg-broadcast/src/main.rs

@@ -1,6 +1,7 @@
 use std::{
     collections::{HashMap, HashSet},
-    sync::{Arc, Mutex},
+    io::BufRead,
+    sync::{mpsc::channel, Arc, Mutex},
     thread,
     time::Duration,
 };
@@ -9,18 +10,28 @@ use nebkor_maelstrom::{protocol::Payload, Body, Message, Node, Runner};
 use rand::Rng;
 
 fn main() {
+    let out = std::io::stdout();
+    let std_in = Arc::new(std::io::stdin());
+
+    let (tx, rx) = channel();
+    let input = tx.clone();
+
+    let i = thread::spawn(move || {
+        let g = std_in.lock();
+        for line in g.lines().map_while(Result::ok) {
+            if let Ok(msg) = serde_json::from_str::<Message>(&line) {
+                input.send(msg).unwrap();
+            }
+        }
+    });
+
     let node = BCaster::default();
     let node = Arc::new(Mutex::new(node));
 
-    let runner = Runner::new(node);
+    let runner = Runner::new(node, out);
     let runner = &runner;
 
-    runner.run(Some(Box::new(on_init)));
-}
-
-fn on_init(runner: &Runner) {
-    let tx = runner.get_backdoor();
-    thread::spawn(move || loop {
+    let g = thread::spawn(move || loop {
         let millis = rand::thread_rng().gen_range(400..=800);
         thread::sleep(Duration::from_millis(millis));
         let body = Body::from_type("do_gossip");
@@ -30,6 +41,10 @@ fn on_init(runner: &Runner) {
         };
         tx.send(msg).unwrap();
     });
+
+    runner.run(rx);
+    let _ = i.join();
+    let _ = g.join();
 }
 
 #[derive(Clone, Default)]
@@ -91,7 +106,7 @@ impl BCaster {
 }
 
 impl Node for BCaster {
-    fn handle(&mut self, runner: &Runner, req: Message) {
+    fn handle(&mut self, runner: &Runner, req: &Message) {
         let typ = req.body.typ.as_str();
         let frm = req.src.as_str();
         let nid = runner.node_id();
@@ -106,7 +121,7 @@ impl Node for BCaster {
                 if let Some(val) = val {
                     self.store.insert(val);
                     let body = Body::from_type("broadcast_ok");
-                    runner.reply(&req, body);
+                    runner.reply(req, body);
                 }
             }
             "read" => {
@@ -116,12 +131,12 @@ impl Node for BCaster {
                     .collect();
                 let body = Body::from_type("read_ok").with_payload(payload);
 
-                runner.reply(&req, body);
+                runner.reply(req, body);
             }
             "topology" => {
                 self.topology(runner.nodes(), nid);
                 let body = Body::from_type("topology_ok");
-                runner.reply(&req, body);
+                runner.reply(req, body);
             }
             "gossip" => {
                 let goss = req

gg-echo/src/main.rs

@@ -1,25 +1,44 @@
-use std::sync::{Arc, Mutex};
+use std::{
+    io::BufRead,
+    sync::{mpsc::channel, Arc, Mutex},
+    thread,
+};
 
 use nebkor_maelstrom::{Body, Message, Node, Runner};
 
 struct Echo;
 
 impl Node for Echo {
-    fn handle(&mut self, runner: &Runner, msg: Message) {
+    fn handle(&mut self, runner: &Runner, msg: &Message) {
         let typ = &msg.body.typ;
         if typ.as_str() == "echo" {
             let body = Body::from_type("echo_ok").with_payload(msg.body.payload.clone());
-            runner.reply(&msg, body);
+            runner.reply(msg, body);
         }
     }
 }
 
 fn main() {
+    let out = std::io::stdout();
+    let std_in = Arc::new(std::io::stdin());
+
+    let (tx, rx) = channel();
+
+    let i = thread::spawn(move || {
+        let g = std_in.lock();
+        for line in g.lines().map_while(Result::ok) {
+            if let Ok(msg) = serde_json::from_str::<Message>(&line) {
+                tx.send(msg).unwrap();
+            }
+        }
+    });
+
     let node = Echo;
 
     let node = Arc::new(Mutex::new(node));
 
-    let runner = Runner::new(node);
+    let runner = Runner::new(node, out);
 
-    runner.run(None);
+    runner.run(rx);
+    i.join().unwrap();
 }

gg-g_counter/Cargo.toml

@@ -1,12 +0,0 @@
-[package]
-name = "gg-g_counter"
-edition = "2021"
-version.workspace = true
-authors.workspace = true
-license-file.workspace = true
-
-[dependencies]
-serde_json.workspace = true
-nebkor-maelstrom = { path = "../nebkor-maelstrom" }
-rand.workspace = true
-

gg-g_counter/src/main.rs

@@ -1,85 +0,0 @@
-use std::sync::{Arc, Mutex};
-
-use nebkor_maelstrom::{mk_payload, Body, Message, Node, Runner};
-
-const KEY: &str = "COUNTER";
-
-#[derive(Clone, Default)]
-struct Counter;
-
-fn main() {
-    let node = Counter;
-    let node = Arc::new(Mutex::new(node));
-
-    let runner = Runner::new(node);
-
-    let on_init = |rnr: &Runner| {
-        let payload = mk_payload(&[
-            ("key", KEY.into()),
-            ("from", 0i64.into()),
-            ("to", 0i64.into()),
-            ("create_if_not_exists", true.into()),
-        ]);
-        let body = Body::from_type("cas").with_payload(payload);
-        rnr.send("seq-kv", body);
-    };
-
-    let on_init = Box::new(on_init);
-
-    runner.run(Some(on_init));
-}
-
-impl Node for Counter {
-    fn handle<'slf>(&'slf mut self, runner: &'slf Runner, req: Message) {
-        let read_payload = mk_payload(&[("key", KEY.into())]);
-        let read_body = Body::from_type("read").with_payload(read_payload);
-        let typ = req.body.typ.as_str();
-        //let frm = req.src.clone();
-        //let msg_id = req.body.msg_id.to_owned();
-        match typ {
-            "add" => {
-                let delta = req.body.payload.get("delta").unwrap().as_i64().unwrap();
-                let cur = runner
-                    .rpc("seq-kv", read_body)
-                    .recv()
-                    .unwrap()
-                    .body
-                    .payload
-                    .get("value")
-                    .cloned()
-                    .unwrap()
-                    .as_i64()
-                    .unwrap();
-                let cas_payload = mk_payload(&[
-                    ("key", KEY.into()),
-                    ("from", cur.into()),
-                    ("to", (cur + delta).into()),
-                ]);
-                // ERRORS BE HERE
-                runner
-                    .rpc("seq-kv", Body::from_type("cas").with_payload(cas_payload))
-                    .recv()
-                    .unwrap();
-                runner.reply(&req, Body::from_type("add_ok"));
-            }
-            "read" => {
-                let payload = mk_payload(&[("key", KEY.into())]);
-                let body = Body::from_type("read").with_payload(payload);
-                let val = runner
-                    .rpc("seq-kv", body)
-                    .recv()
-                    .unwrap()
-                    .body
-                    .payload
-                    .get("value")
-                    .cloned()
-                    .unwrap();
-                let body = Body::from_type("read_ok").with_payload(mk_payload(&[("value", val)]));
-                runner.reply(&req, body);
-            }
-            _ => {
-                eprintln!("unknown type: {req:?}");
-            }
-        }
-    }
-}

gg-uid/src/main.rs

@@ -1,21 +1,40 @@
-use std::sync::{Arc, Mutex};
+use std::{
+    io::BufRead,
+    sync::{mpsc::channel, Arc, Mutex},
+    thread,
+};
 
 use nebkor_maelstrom::{protocol::Payload, Body, Message, Node, Runner};
 
 fn main() {
+    let out = std::io::stdout();
+    let std_in = Arc::new(std::io::stdin());
+
+    let (tx, rx) = channel();
+
+    let i = thread::spawn(move || {
+        let g = std_in.lock();
+        for line in g.lines().map_while(Result::ok) {
+            if let Ok(msg) = serde_json::from_str::<Message>(&line) {
+                tx.send(msg).unwrap();
+            }
+        }
+    });
+
     let node = GenUid;
     let node = Arc::new(Mutex::new(node));
 
-    let runner = Runner::new(node);
+    let runner = Runner::new(node, out);
 
-    runner.run(None);
+    runner.run(rx);
+    i.join().unwrap();
 }
 
 #[derive(Clone, Default)]
 struct GenUid;
 
 impl Node for GenUid {
-    fn handle(&mut self, runner: &Runner, msg: Message) {
+    fn handle(&mut self, runner: &Runner, msg: &Message) {
         let id = runner.node_id();
         let mid = runner.next_msg_id();
         if msg.body.typ == "generate" {
@@ -26,7 +45,7 @@ impl Node for GenUid {
                 .with_msg_id(mid)
                 .with_payload(payload);
 
-            runner.reply(&msg, body);
+            runner.reply(msg, body);
         }
     }
 }

nebkor-maelstrom/README.md

@@ -1,69 +0,0 @@
-# A synchronous and simple Maelstrom crate
-
-`nebkor-maelstreom` is a lean and simple synchronous library for writing
-[Maelstrom](https://github.com/jepsen-io/maelstrom/tree/0186f398f96564a0453dda97c07daeac67c3d8d7)-compatible
-distributed actors. It has three dependencies:
-
- - serde
- - serde_json
- - serde_repr
- 
-For a simple example, see the [gg-ehco](../gg-echo/src/main.rs) program:
-
-``` rust
-use std::sync::{Arc, Mutex};
-
-use nebkor_maelstrom::{Body, Message, Node, Runner};
-
-struct Echo;
-
-impl Node for Echo {
-    fn handle(&mut self, runner: &Runner, msg: Message) {
-        let typ = &msg.body.typ;
-        if typ.as_str() == "echo" {
-            let body = Body::from_type("echo_ok").with_payload(msg.body.payload.clone());
-            runner.reply(&msg, body);
-        }
-    }
-}
-
-fn main() {
-    let node = Echo;
-
-    let node = Arc::new(Mutex::new(node));
-
-    let runner = Runner::new(node);
-
-    runner.run(None);
-}
-```
-
-## How to use
-
-Create a struct and implement `nebkor_maelstrom::Node` for it, which involves a single method,
-`handle(&mut self, &Runner, Message)`. This method is passed a `Runner` which contains methods like
-`send`, `reply`, and `rpc`.
-
-In your main function, instantiate that struct and wrap it in an `Arc<Mutex<>>`, then 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 received; see the [broadcast](../gg-broadcast/src/main.rs) program for an
-example of that, where it spawns a thread to send periodic messages to the node.
-
-## Design considerations
-
-I wanted the client code to be as simple as possible, with the least amount of boilerplate. Using
-`&mut self` as the receiver for the `handle()` method lets you easily mutate state in your node if
-you need to, without the ceremony of `Rc<Mutex<>>` and the like. Eschewing `async` results in an
-order of magnitude fewer dependencies, and the entire workspace (crate and clients) can be compiled
-in a couple seconds.
-
-## 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!
-
-
-## TODO
-
- - add error handling.

nebkor-maelstrom/src/kv.rs

@@ -1,51 +0,0 @@
-/*
-use std::{rc::Rc, sync::Arc};
-
-use serde_json::Value;
-
-use crate::{mk_payload, Body, Message, Result, Runner};
-
-#[derive(Debug, Default, Clone)]
-pub struct Kv {
-    pub service: String,
-}
-
-impl Kv {
-    pub fn seq() -> Self {
-        Kv {
-            service: "seq-kv".to_string(),
-        }
-    }
-
-    pub fn lin() -> Self {
-        Kv {
-            service: "lin-kv".to_string(),
-        }
-    }
-
-    pub fn lww() -> Self {
-        Kv {
-            service: "lww-kv".to_string(),
-        }
-    }
-
-    pub fn read(&self, runner: &Runner, key: &str) -> Result<Value> {
-        todo!()
-    }
-
-    pub fn write(&self, runner: &Runner, key: &str, val: Value, create: bool) -> Result<()> {
-        todo!()
-    }
-
-    pub fn cas(
-        &self,
-        runner: &Runner,
-        key: &str,
-        from: Value,
-        to: Value,
-        create: bool,
-    ) -> Result<()> {
-        todo!()
-    }
-}
-*/

nebkor-maelstrom/src/lib.rs

@@ -1,174 +1,66 @@
 use std::{
-    collections::HashMap,
-    io::{BufRead, Write},
+    io::{Stdout, Write},
     sync::{
         atomic::{AtomicU64, AtomicUsize, Ordering},
-        mpsc::{channel, Receiver, Sender},
         Arc, Mutex, OnceLock,
     },
-    thread::{self},
 };
 
 pub mod protocol;
-use protocol::ErrorCode;
-pub use protocol::{Body, Message, Payload};
-use serde_json::Value;
-
-pub mod kv;
+pub use protocol::{Body, Message};
 
 pub type DynNode = Arc<Mutex<dyn Node>>;
-pub type OnInit = Box<dyn Fn(&Runner)>;
-
-pub type Result<T> = std::result::Result<T, ErrorCode>;
-
-pub type RpcPromise = Receiver<Message>;
-
-static MSG_ID: AtomicU64 = AtomicU64::new(0);
 
 pub trait Node {
-    fn handle(&mut self, runner: &Runner, msg: Message);
-}
-
-#[derive(Debug, Clone)]
-pub struct Network {
-    promises: Arc<Mutex<HashMap<u64, Sender<Message>>>>,
-    node_output_tx: Sender<Message>,
-}
-
-impl Network {
-    pub fn new() -> (Self, Receiver<Message>) {
-        let (node_output_tx, node_output_rx) = channel();
-        let net = Self {
-            node_output_tx,
-            promises: Arc::new(Mutex::new(HashMap::default())),
-        };
-        (net, node_output_rx)
-    }
-
-    pub fn send(&self, msg: Message) {
-        self.node_output_tx.send(msg).unwrap();
-    }
-
-    pub fn rpc(&self, msg: Message) -> RpcPromise {
-        let (tx, rx) = channel();
-        {
-            let msg_id = msg.body.msg_id;
-            let mut g = self.promises.lock().unwrap();
-            g.insert(msg_id, tx);
-        }
-        self.send(msg);
-        rx
-    }
+    fn handle(&mut self, runner: &Runner, msg: &Message);
 }
 
 pub struct Runner {
+    msg_id: AtomicU64,
     node: DynNode,
     node_id: OnceLock<String>,
     nodes: OnceLock<Vec<String>>,
-    network: OnceLock<Network>,
-    backdoor: OnceLock<Sender<Message>>,
-    steps: Arc<AtomicUsize>,
+    steps: AtomicUsize,
+    output: Arc<Mutex<Stdout>>,
 }
 
 impl Runner {
-    pub fn new(node: DynNode) -> Self {
+    pub fn new(node: DynNode, output: Stdout) -> Self {
         Runner {
             node,
+            msg_id: AtomicU64::new(1),
             nodes: OnceLock::new(),
             node_id: OnceLock::new(),
-            network: OnceLock::new(),
-            backdoor: OnceLock::new(),
-            steps: Arc::new(AtomicUsize::new(0)),
+            steps: AtomicUsize::new(0),
+            output: Arc::new(Mutex::new(output)),
         }
     }
 
-    pub fn run(&self, on_init: Option<OnInit>) {
-        let (stdin_tx, stdin_rx) = channel();
-        let (stdout_tx, stdout_rx) = channel();
-
-        thread::spawn(move || {
-            let stdin = std::io::stdin().lock().lines();
-            for line in stdin {
-                stdin_tx.send(line.unwrap()).unwrap();
-            }
-        });
-
-        thread::spawn(move || {
-            let mut stdout = std::io::stdout().lock();
-            for msg in stdout_rx {
-                writeln!(&mut stdout, "{msg}").unwrap();
-            }
-        });
-
-        self.run_internal(stdout_tx, stdin_rx, on_init);
-    }
-
-    fn run_internal(
-        &self,
-        stdout_tx: Sender<String>,
-        stdin_rx: Receiver<String>,
-        on_init: Option<OnInit>,
-    ) {
-        let (network, node_receiver) = Network::new();
-        let _ = self.network.get_or_init(|| network.clone());
-        self.run_output(stdout_tx, node_receiver);
-        self.run_input(stdin_rx, network, on_init);
-    }
-
-    fn run_input(&self, stdin_rx: Receiver<String>, network: Network, on_init: Option<OnInit>) {
-        let (json_tx, json_rx) = channel();
-        let _ = self.backdoor.get_or_init(|| json_tx.clone());
-
-        thread::spawn(move || {
-            for line in stdin_rx {
-                let msg: Message = serde_json::from_str(&line).unwrap();
-                let irt = msg.body.in_reply_to;
-                if let Some(tx) = network.promises.lock().unwrap().remove(&irt) {
-                    tx.send(msg).unwrap();
-                } else {
-                    json_tx.send(msg).unwrap();
-                }
-            }
-        });
-
-        for msg in json_rx {
-            let mut node = self.node.lock().unwrap();
-            if msg.body.typ.as_str() == "init" {
+    pub fn run(&self, input: std::sync::mpsc::Receiver<Message>) {
+        for msg in input.iter() {
+            self.steps.fetch_add(1, Ordering::SeqCst);
+            let typ = &msg.body.typ;
+            if let "init" = typ.as_str() {
                 self.init(&msg);
                 let body = Body::from_type("init_ok");
                 self.reply(&msg, body);
-                if let Some(ref on_init) = on_init {
-                    on_init(self);
-                }
             } else {
-                node.handle(self, msg);
+                let mut n = self.node.lock().unwrap();
+                n.handle(self, &msg);
             }
         }
     }
 
-    fn run_output(&self, stdout_tx: Sender<String>, node_output_rx: Receiver<Message>) {
-        thread::spawn(move || {
-            while let Ok(msg) = node_output_rx.recv() {
-                let msg = serde_json::to_string(&msg).unwrap();
-                stdout_tx.send(msg).unwrap();
-            }
-        });
-    }
-
-    pub fn get_backdoor(&self) -> Sender<Message> {
-        self.backdoor.get().unwrap().clone()
-    }
-
     pub fn node_id(&self) -> String {
         self.node_id.get().cloned().unwrap_or_default()
     }
 
     pub fn next_msg_id(&self) -> u64 {
-        MSG_ID.fetch_add(1, Ordering::SeqCst)
+        self.msg_id.fetch_add(1, Ordering::SeqCst)
     }
 
     pub fn cur_msg_id(&self) -> u64 {
-        MSG_ID.load(Ordering::SeqCst)
+        self.msg_id.load(Ordering::SeqCst)
     }
 
     pub fn nodes(&self) -> &[String] {
@@ -198,18 +90,18 @@ impl Runner {
             .unwrap()
             .iter()
             .map(|s| s.as_str().unwrap().to_string())
-            .collect();
+            .collect::<Vec<_>>();
 
-        let _ = self.node_id.get_or_init(|| node_id);
-        let _ = self.nodes.get_or_init(|| nodes);
+        let _ = self.node_id.get_or_init(|| node_id.to_owned());
+        let _ = self.nodes.get_or_init(|| nodes.to_vec());
     }
 
     pub fn reply(&self, req: &Message, body: Body) {
         let mut body = body;
-        let dest = req.src.as_str();
+        let dest = req.src.clone();
         let in_reply_to = req.body.msg_id;
         body.in_reply_to = in_reply_to;
-        self.send(dest, body);
+        self.send(&dest, body);
     }
 
     pub fn send(&self, dest: &str, body: Body) {
@@ -222,26 +114,14 @@ impl Runner {
             dest: dest.to_string(),
             body,
         };
-        self.network.get().unwrap().send(msg);
+        let msg = serde_json::to_string(&msg).unwrap();
+        self.writeln(&msg);
     }
 
-    pub fn rpc(&self, dest: &str, body: Body) -> RpcPromise {
-        let mut body = body;
-        if body.msg_id == 0 {
-            body.msg_id = self.next_msg_id();
-        }
-        let msg = Message {
-            src: self.node_id().to_string(),
-            dest: dest.to_string(),
-            body,
-        };
-        self.network.get().unwrap().rpc(msg)
+    fn writeln(&self, msg: &str) {
+        let mut out = self.output.lock().unwrap();
+        let msg = format!("{msg}\n");
+        out.write_all(msg.as_bytes()).unwrap();
+        out.flush().unwrap();
     }
 }
-
-pub fn mk_payload(payload: &[(&str, Value)]) -> Payload {
-    payload
-        .iter()
-        .map(|p| (p.0.to_string(), p.1.clone()))
-        .collect()
-}