docs: update some UDP server comments

Author: josecelano

src/servers/udp/server/mod.rs

@@ -1,22 +1,4 @@
 //! Module to handle the UDP server instances.
-//!
-//! There are two main types in this module:
-//!
-//! - [`UdpServer`]: a controller to start and stop the server.
-//! - [`Udp`]: the server launcher.
-//!
-//! The `UdpServer` is an state machine for a given configuration. This struct
-//! represents concrete configuration and state. It allows to start and
-//! stop the server but always keeping the same configuration.
-//!
-//! The `Udp` is the server launcher. It's responsible for launching the UDP
-//! but without keeping any state.
-//!
-//! For the time being, the `UdpServer` is only used for testing purposes,
-//! because we want to be able to start and stop the server multiple times, and
-//! we want to know the bound address and the current state of the server.
-//! In production, the `Udp` launcher is used directly.
-
 use std::fmt::Debug;
 
 use super::RawRequest;
@@ -37,7 +19,7 @@ pub mod states;
 ///
 /// Some errors triggered while stopping the server are:
 ///
-/// - The [`UdpServer`] cannot send the shutdown signal to the spawned UDP service thread.
+/// - The [`Server`] cannot send the shutdown signal to the spawned UDP service thread.
 #[derive(Debug)]
 pub enum UdpError {
     /// Any kind of error starting or stopping the server.
@@ -92,7 +74,7 @@ mod tests {
 
         tokio::time::sleep(Duration::from_secs(1)).await;
 
-        assert_eq!(stopped.state.launcher.bind_to, bind_to);
+        assert_eq!(stopped.state.spawner.bind_to, bind_to);
     }
 
     #[tokio::test]
@@ -116,7 +98,7 @@ mod tests {
 
         tokio::time::sleep(Duration::from_secs(1)).await;
 
-        assert_eq!(stopped.state.launcher.bind_to, bind_to);
+        assert_eq!(stopped.state.spawner.bind_to, bind_to);
     }
 }
 

src/servers/udp/server/spawner.rs

@@ -1,3 +1,4 @@
+//! A thin wrapper for tokio spawn to launch the UDP server launcher as a new task.
 use std::net::SocketAddr;
 use std::sync::Arc;
 
@@ -16,21 +17,22 @@ pub struct Spawner {
 }
 
 impl Spawner {
-    /// It spawns a new tasks to run the UDP server instance.
+    /// It spawns a new task to run the UDP server instance.
     ///
     /// # Panics
     ///
     /// It would panic if unable to resolve the `local_addr` from the supplied ´socket´.
-    pub fn start(
+    pub fn spawn_launcher(
         &self,
         tracker: Arc<Tracker>,
         tx_start: oneshot::Sender<Started>,
         rx_halt: oneshot::Receiver<Halted>,
     ) -> JoinHandle<Spawner> {
-        let launcher = Spawner::new(self.bind_to);
+        let spawner = Self::new(self.bind_to);
+
         tokio::spawn(async move {
-            Launcher::run_with_graceful_shutdown(tracker, launcher.bind_to, tx_start, rx_halt).await;
-            launcher
+            Launcher::run_with_graceful_shutdown(tracker, spawner.bind_to, tx_start, rx_halt).await;
+            spawner
         })
     }
 }

src/servers/udp/server/states.rs

@@ -25,7 +25,7 @@ pub type RunningUdpServer = Server<Running>;
 /// A stopped UDP server state.
 
 pub struct Stopped {
-    pub launcher: Spawner,
+    pub spawner: Spawner,
 }
 
 /// A running UDP server state.
@@ -40,9 +40,9 @@ pub struct Running {
 impl Server<Stopped> {
     /// Creates a new `UdpServer` instance in `stopped`state.
     #[must_use]
-    pub fn new(launcher: Spawner) -> Self {
+    pub fn new(spawner: Spawner) -> Self {
         Self {
-            state: Stopped { launcher },
+            state: Stopped { spawner },
         }
     }
 
@@ -64,7 +64,7 @@ impl Server<Stopped> {
         assert!(!tx_halt.is_closed(), "Halt channel for UDP tracker should be open");
 
         // May need to wrap in a task to about a tokio bug.
-        let task = self.state.launcher.start(tracker, tx_start, rx_halt);
+        let task = self.state.spawner.spawn_launcher(tracker, tx_start, rx_halt);
 
         let binding = rx_start.await.expect("it should be able to start the service").address;
         let local_addr = format!("udp://{binding}");
@@ -107,7 +107,7 @@ impl Server<Running> {
         let launcher = self.state.task.await.expect("it should shutdown service");
 
         let stopped_api_server: Server<Stopped> = Server {
-            state: Stopped { launcher },
+            state: Stopped { spawner: launcher },
         };
 
         Ok(stopped_api_server)