use human_units for Duration params

Cargo.lock

@@ -279,6 +279,7 @@ dependencies = [
  "futures-util",
  "glob",
  "hex",
+ "human-units",
  "log",
  "lz4",
  "nix",
@@ -586,6 +587,15 @@ version = "1.10.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6dbf3de79e51f3d586ab4cb9d5c3e2c14aa28ed23d180cf89b4df0454a69cc87"
 
+[[package]]
+name = "human-units"
+version = "0.5.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "47cf34dbcbbb7f1f6589c18e26f15a5a72592750dd5472037eb78fc0f92020d4"
+dependencies = [
+ "paste",
+]
+
 [[package]]
 name = "hyper"
 version = "1.8.1"
@@ -1059,6 +1069,12 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "paste"
+version = "1.0.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "57c0d7b74b563b49d38dae00a0c37d4d6de9b432382b2892f0574ddcae73fd0a"
+
 [[package]]
 name = "percent-encoding"
 version = "2.3.2"

Cargo.toml

@@ -24,6 +24,7 @@ futures = "0.3.31"
 futures-util = "0.3.31"
 glob = "0.3.2"
 hex = "0.4.3"
+human-units = "0.5.3"
 log = "0.4.27"
 lz4 = "1.28.1"
 nix = { version = "0.30.1", features = ["user"] }

src/bin/dkl.rs

@@ -1,8 +1,8 @@
 use clap::{CommandFactory, Parser, Subcommand};
 use eyre::{format_err, Result};
+use human_units::Duration;
 use log::{debug, error};
 use std::net::SocketAddr;
-use std::time::Duration;
 use tokio::fs;
 
 #[derive(Parser)]
@@ -71,12 +71,12 @@ enum Command {
         #[arg(long, short = 'l')]
         listen: Vec<SocketAddr>,
         targets: Vec<SocketAddr>,
-        /// target polling interval, in seconds
-        #[arg(long, default_value = "30")]
-        poll: u16,
-        /// connect or check timeout, in seconds
-        #[arg(long, default_value = "5")]
-        timeout: u16,
+        /// target polling interval
+        #[arg(long, default_value = "30s")]
+        poll: Duration,
+        /// connect or check timeout
+        #[arg(long, default_value = "5s")]
+        timeout: Duration,
     },
 }
 
@@ -147,8 +147,8 @@ async fn main() -> Result<()> {
         } => Ok(dkl::proxy::Proxy {
             listen_addrs: listen,
             targets,
-            poll_interval: Duration::from_secs(poll.into()),
-            timeout: Duration::from_secs(timeout.into()),
+            poll: poll.into(),
+            timeout: timeout.into(),
         }
         .run()
         .await

src/proxy.rs

@@ -1,16 +1,17 @@
-use log::info;
+use log::{info, log_enabled, warn};
 use std::convert::Infallible;
+use std::io;
 use std::net::SocketAddr;
-use std::sync::atomic::Ordering::Relaxed;
-use std::sync::{atomic::AtomicBool, Arc};
+use std::sync::atomic::{AtomicBool, Ordering::Relaxed};
 use std::time::Duration;
 use thiserror::Error;
 use tokio::net::{TcpListener, TcpStream};
+use tokio::time;
 
 pub struct Proxy {
     pub listen_addrs: Vec<SocketAddr>,
     pub targets: Vec<SocketAddr>,
-    pub poll_interval: Duration,
+    pub poll: Duration,
     pub timeout: Duration,
 }
 
@@ -36,76 +37,96 @@ impl Proxy {
 
         // all targets are initially ok (better land on a down one than just fail)
         let targets: Vec<_> = (self.targets.into_iter())
-            .map(|t| TargetStatus(t, AtomicBool::new(true)))
+            .map(|addr| TargetStatus {
+                addr,
+                up: AtomicBool::new(true),
+                timeout: self.timeout,
+            })
             .collect();
-        let targets = Arc::new(targets);
+
+        // the proxy runs forever -> using 'static is not a leak
+        let targets = targets.leak();
 
         for listener in listeners {
-            tokio::spawn(proxy_listener(listener, targets.clone()));
+            tokio::spawn(proxy_listener(listener, targets));
         }
 
-        check_targets(targets.clone(), self.poll_interval, self.timeout).await
+        check_targets(targets, self.poll).await
     }
 }
 
-struct TargetStatus(SocketAddr, AtomicBool);
+struct TargetStatus {
+    addr: SocketAddr,
+    up: AtomicBool,
+    timeout: Duration,
+}
 impl TargetStatus {
     fn is_up(&self) -> bool {
-        self.1.load(Relaxed)
+        self.up.load(Relaxed)
+    }
+
+    fn set_up(&self, is_up: bool) {
+        let prev = self.up.swap(is_up, Relaxed);
+        if prev != is_up {
+            if is_up {
+                info!("{} is up", self.addr);
+            } else {
+                warn!("{} is down", self.addr);
+            }
+        }
+    }
+
+    async fn connect(&self) -> io::Result<TcpStream> {
+        let r = match time::timeout(self.timeout, TcpStream::connect(self.addr)).await {
+            Ok(r) => r,
+            Err(e) => Err(io::Error::new(io::ErrorKind::TimedOut, e)),
+        };
+
+        self.set_up(r.is_ok());
+        r
     }
 }
 
-async fn check_targets(targets: Arc<Vec<TargetStatus>>, poll: Duration, timeout: Duration) -> ! {
+async fn check_targets(targets: &'static [TargetStatus], poll: Duration) -> ! {
     use tokio::time;
     let mut poll_ticker = time::interval(poll);
     poll_ticker.set_missed_tick_behavior(time::MissedTickBehavior::Skip);
 
-    let mut first = true;
-
     loop {
         poll_ticker.tick().await;
 
-        for i in 0..targets.len() {
-            let targets = targets.clone();
-            tokio::spawn(async move { check_target(&targets[i], timeout, first).await });
+        let mut tasks = tokio::task::JoinSet::new();
+
+        for target in targets {
+            tasks.spawn(target.connect());
         }
 
-        first = false;
+        tasks.join_all().await;
+
+        if log_enabled!(log::Level::Info) {
+            let mut infos = String::new();
+            for ts in targets.iter() {
+                infos.push_str(&format!("{} ", ts.addr));
+                infos.push_str(if ts.is_up() { "up   " } else { "down " });
             }
-}
-
-async fn check_target(ts: &TargetStatus, timeout: Duration, first: bool) {
-    let target = ts.0;
-
-    let is_up = match tokio::time::timeout(timeout, TcpStream::connect(target)).await {
-        Ok(Ok(_)) => true,
-        _ => false,
-    };
-
-    let prev = ts.1.swap(is_up, Relaxed);
-
-    if first || prev != is_up {
-        if is_up {
-            info!("{target} is up");
-        } else {
-            info!("{target} is down");
+            info!("{infos}");
         }
     }
 }
 
-async fn proxy_listener(listener: TcpListener, targets: Arc<Vec<TargetStatus>>) {
+async fn proxy_listener(listener: TcpListener, targets: &'static [TargetStatus]) {
     let mut rng = fastrand::Rng::new();
 
     loop {
         let mut active = Vec::with_capacity(targets.len());
         let (mut src, _) = listener.accept().await.expect("listener.accept() failed");
 
-        active.extend(targets.iter().filter(|ts| ts.is_up()).map(|ts| ts.0));
+        active.extend((targets.iter().enumerate()).filter_map(|(i, ts)| ts.is_up().then_some(i)));
         rng.shuffle(&mut active);
 
         tokio::spawn(async move {
-            for target in active {
-                if let Ok(mut dst) = TcpStream::connect(target).await {
+            for i in active {
+                if let Ok(mut dst) = targets[i].connect().await {
                     let _ = tokio::io::copy_bidirectional(&mut src, &mut dst).await;
                     break;
                 }