Change how set_socket_options works to be an extension trait.

crates/maelstrom-util/src/net.rs

@@ -126,12 +126,18 @@ where
     }
 }
 
-pub fn set_socket_options(socket: &impl AsRawFd) -> Result<()> {
-    let fd = Fd::from_raw(socket.as_raw_fd());
-    linux::setsockopt_tcp_nodelay(&fd, true)?;
-    linux::setsockopt_so_keepalive(&fd, true)?;
-    linux::setsockopt_tcp_keepcnt(&fd, 3)?;
-    linux::setsockopt_tcp_keepidle(&fd, 300)?;
-    linux::setsockopt_tcp_keepintvl(&fd, 300)?;
-    Ok(())
+pub trait AsRawFdExt: Sized {
+    fn set_socket_options(self) -> Result<Self>;
+}
+
+impl<T: AsRawFd> AsRawFdExt for T {
+    fn set_socket_options(self) -> Result<Self> {
+        let fd = Fd::from_raw(self.as_raw_fd());
+        linux::setsockopt_tcp_nodelay(&fd, true)?;
+        linux::setsockopt_so_keepalive(&fd, true)?;
+        linux::setsockopt_tcp_keepcnt(&fd, 3)?;
+        linux::setsockopt_tcp_keepidle(&fd, 300)?;
+        linux::setsockopt_tcp_keepintvl(&fd, 300)?;
+        Ok(self)
+    }
 }

crates/maelstrom-worker/src/artifact_fetcher.rs

@@ -11,7 +11,8 @@ use maelstrom_util::{
     cache::{fs::TempFile as _, GotArtifact},
     config::common::BrokerAddr,
     fs::Fs,
-    io, net,
+    io,
+    net::{self, AsRawFdExt as _},
     sync::Pool,
 };
 use slog::{debug, o, warn, Logger};
@@ -93,8 +94,7 @@ fn main(
             Some(stream) => (stream, true),
             None => {
                 debug!(log, "artifact fetcher connecting to broker");
-                let mut stream = TcpStream::connect(broker_addr.inner())?;
-                net::set_socket_options(&stream)?;
+                let mut stream = TcpStream::connect(broker_addr.inner())?.set_socket_options()?;
 
                 net::write_message_to_socket(&mut stream, Hello::ArtifactFetcher, log)?;
 

crates/maelstrom-worker/src/lib.rs

@@ -23,7 +23,8 @@ use maelstrom_linux::{self as linux};
 use maelstrom_util::{
     cache::{fs::std::Fs as StdFs, CacheDir},
     config::common::Slots,
-    net, signal,
+    net::{self, AsRawFdExt as _},
+    signal,
 };
 use slog::{debug, error, info, Logger};
 use std::{future::Future, process};
@@ -50,14 +51,14 @@ pub async fn main_inner(config: Config, log: Logger) -> Result<()> {
 
     check_open_file_limit(&log, config.slots, 0)?;
 
-    let stream = TcpStream::connect(config.broker.inner())
+    let (read_stream, mut write_stream) = TcpStream::connect(config.broker.inner())
         .await
         .map_err(|err| {
             error!(log, "error connecting to broker"; "error" => %err);
             err
-        })?;
-    net::set_socket_options(&stream)?;
-    let (read_stream, mut write_stream) = stream.into_split();
+        })?
+        .set_socket_options()?
+        .into_split();
     let read_stream = BufReader::new(read_stream);
 
     net::write_message_to_async_socket(