Merge pull request #19 from lambdaclass/default_handlers

ElFantasma · web-flow · commit c6f757c0cc07 · 2025-06-30T15:27:34.000-03:00
Added default implementation for handle_cast and handle_call
diff --git a/concurrency/src/error.rs b/concurrency/src/error.rs
@@ -0,0 +1,36 @@
+use std::{error::Error as StdError, fmt::Display};
+
+#[derive(Debug)]
+pub enum GenServerError {
+    Callback,
+    Initialization,
+    Server,
+    CallMsgUnused,
+    CastMsgUnused,
+}
+
+impl<T> From<spawned_rt::threads::mpsc::SendError<T>> for GenServerError {
+    fn from(_value: spawned_rt::threads::mpsc::SendError<T>) -> Self {
+        Self::Server
+    }
+}
+
+impl<T> From<spawned_rt::tasks::mpsc::SendError<T>> for GenServerError {
+    fn from(_value: spawned_rt::tasks::mpsc::SendError<T>) -> Self {
+        Self::Server
+    }
+}
+
+impl Display for GenServerError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Self::Callback => write!(f, "Callback Error"),
+            Self::Initialization => write!(f, "Initialization Error"),
+            Self::Server => write!(f, "Server Error"),
+            Self::CallMsgUnused => write!(f, "Unsupported Call Messages on this GenServer"),
+            Self::CastMsgUnused => write!(f, "Unsupported Cast Messages on this GenServer"),
+        }
+    }
+}
+
+impl StdError for GenServerError {}
diff --git a/concurrency/src/lib.rs b/concurrency/src/lib.rs
@@ -1,5 +1,6 @@
 //! spawned concurrency
 //! Some basic traits and structs to implement concurrent code à-la-Erlang.
-
+pub mod error;
+pub mod messages;
 pub mod tasks;
 pub mod threads;
diff --git a/concurrency/src/messages.rs b/concurrency/src/messages.rs
@@ -0,0 +1,2 @@
+#[derive(Clone)]
+pub struct Unused;
diff --git a/concurrency/src/tasks/error.rs b/concurrency/src/tasks/error.rs
diff --git a/concurrency/src/tasks/gen_server.rs b/concurrency/src/tasks/gen_server.rs
@@ -4,7 +4,7 @@ use futures::future::FutureExt as _;
 use spawned_rt::tasks::{self as rt, mpsc, oneshot};
 use std::{fmt::Debug, future::Future, panic::AssertUnwindSafe};
 
-use super::error::GenServerError;
+use crate::error::GenServerError;
 
 #[derive(Debug)]
 pub struct GenServerHandle<G: GenServer + 'static> {
@@ -93,11 +93,13 @@ pub enum GenServerInMsg<G: GenServer> {
 
 pub enum CallResponse<G: GenServer> {
     Reply(G::State, G::OutMsg),
+    Unused,
     Stop(G::OutMsg),
 }
 
 pub enum CastResponse<G: GenServer> {
     NoReply(G::State),
+    Unused,
     Stop,
 }
 
@@ -181,7 +183,7 @@ where
         handle: &GenServerHandle<Self>,
         rx: &mut mpsc::Receiver<GenServerInMsg<Self>>,
         state: Self::State,
-    ) -> impl std::future::Future<Output = Result<(Self::State, bool), GenServerError>> + Send {
+    ) -> impl Future<Output = Result<(Self::State, bool), GenServerError>> + Send {
         async move {
             let message = rx.recv().await;
 
@@ -200,17 +202,21 @@ where
                                     (true, new_state, Ok(response))
                                 }
                                 CallResponse::Stop(response) => (false, state_clone, Ok(response)),
+                                CallResponse::Unused => {
+                                    tracing::error!("GenServer received unexpected CallMessage");
+                                    (false, state_clone, Err(GenServerError::CallMsgUnused))
+                                }
                             },
                             Err(error) => {
-                                tracing::trace!(
+                                tracing::error!(
                                     "Error in callback, reverting state - Error: '{error:?}'"
                                 );
                                 (true, state_clone, Err(GenServerError::Callback))
                             }
                         };
                     // Send response back
                     if sender.send(response).is_err() {
-                        tracing::trace!(
+                        tracing::error!(
                             "GenServer failed to send response back, client must have died"
                         )
                     };
@@ -224,6 +230,10 @@ where
                         Ok(response) => match response {
                             CastResponse::NoReply(new_state) => (true, new_state),
                             CastResponse::Stop => (false, state_clone),
+                            CastResponse::Unused => {
+                                tracing::error!("GenServer received unexpected CastMessage");
+                                (false, state_clone)
+                            }
                         },
                         Err(error) => {
                             tracing::trace!(
@@ -244,17 +254,21 @@ where
 
     fn handle_call(
         &mut self,
-        message: Self::CallMsg,
-        handle: &GenServerHandle<Self>,
-        state: Self::State,
-    ) -> impl std::future::Future<Output = CallResponse<Self>> + Send;
+        _message: Self::CallMsg,
+        _handle: &GenServerHandle<Self>,
+        _state: Self::State,
+    ) -> impl Future<Output = CallResponse<Self>> + Send {
+        async { CallResponse::Unused }
+    }
 
     fn handle_cast(
         &mut self,
-        message: Self::CastMsg,
-        handle: &GenServerHandle<Self>,
-        state: Self::State,
-    ) -> impl std::future::Future<Output = CastResponse<Self>> + Send;
+        _message: Self::CastMsg,
+        _handle: &GenServerHandle<Self>,
+        _state: Self::State,
+    ) -> impl Future<Output = CastResponse<Self>> + Send {
+        async { CastResponse::Unused }
+    }
 }
 
 #[cfg(test)]
diff --git a/concurrency/src/tasks/mod.rs b/concurrency/src/tasks/mod.rs
@@ -1,15 +1,13 @@
 //! spawned concurrency
 //! Runtime tasks-based traits and structs to implement concurrent code à-la-Erlang.
 
-mod error;
 mod gen_server;
 mod process;
 mod time;
 
 #[cfg(test)]
 mod timer_tests;
 
-pub use error::GenServerError;
 pub use gen_server::{CallResponse, CastResponse, GenServer, GenServerHandle, GenServerInMsg};
 pub use process::{send, Process, ProcessInfo};
 pub use time::{send_after, send_interval};
diff --git a/concurrency/src/threads/error.rs b/concurrency/src/threads/error.rs
diff --git a/concurrency/src/threads/gen_server.rs b/concurrency/src/threads/gen_server.rs
@@ -6,7 +6,7 @@ use std::{
     panic::{catch_unwind, AssertUnwindSafe},
 };
 
-use super::error::GenServerError;
+use crate::error::GenServerError;
 
 #[derive(Debug)]
 pub struct GenServerHandle<G: GenServer + 'static> {
@@ -71,11 +71,13 @@ pub enum GenServerInMsg<G: GenServer> {
 
 pub enum CallResponse<G: GenServer> {
     Reply(G::State, G::OutMsg),
+    Unused,
     Stop(G::OutMsg),
 }
 
 pub enum CastResponse<G: GenServer> {
     NoReply(G::State),
+    Unused,
     Stop,
 }
 
@@ -169,6 +171,10 @@ where
                                 (true, new_state, Ok(response))
                             }
                             CallResponse::Stop(response) => (false, state_clone, Ok(response)),
+                            CallResponse::Unused => {
+                                tracing::error!("GenServer received unexpected CallMessage");
+                                (false, state_clone, Err(GenServerError::CallMsgUnused))
+                            }
                         },
                         Err(error) => {
                             tracing::trace!(
@@ -190,6 +196,10 @@ where
                     Ok(response) => match response {
                         CastResponse::NoReply(new_state) => (true, new_state),
                         CastResponse::Stop => (false, state_clone),
+                        CastResponse::Unused => {
+                            tracing::error!("GenServer received unexpected CastMessage");
+                            (false, state_clone)
+                        }
                     },
                     Err(error) => {
                         tracing::trace!("Error in callback, reverting state - Error: '{error:?}'");
@@ -207,15 +217,19 @@ where
 
     fn handle_call(
         &mut self,
-        message: Self::CallMsg,
-        handle: &GenServerHandle<Self>,
-        state: Self::State,
-    ) -> CallResponse<Self>;
+        _message: Self::CallMsg,
+        _handle: &GenServerHandle<Self>,
+        _state: Self::State,
+    ) -> CallResponse<Self> {
+        CallResponse::Unused
+    }
 
     fn handle_cast(
         &mut self,
-        message: Self::CastMsg,
-        handle: &GenServerHandle<Self>,
-        state: Self::State,
-    ) -> CastResponse<Self>;
+        _message: Self::CastMsg,
+        _handle: &GenServerHandle<Self>,
+        _state: Self::State,
+    ) -> CastResponse<Self> {
+        CastResponse::Unused
+    }
 }
diff --git a/concurrency/src/threads/mod.rs b/concurrency/src/threads/mod.rs
@@ -1,7 +1,6 @@
 //! spawned concurrency
 //! IO threads-based traits and structs to implement concurrent code à-la-Erlang.
 
-mod error;
 mod gen_server;
 mod process;
 mod time;
diff --git a/examples/bank/src/server.rs b/examples/bank/src/server.rs
@@ -1,6 +1,9 @@
 use std::collections::HashMap;
 
-use spawned_concurrency::tasks::{CallResponse, CastResponse, GenServer, GenServerHandle};
+use spawned_concurrency::{
+    messages::Unused,
+    tasks::{CallResponse, GenServer, GenServerHandle},
+};
 
 use crate::messages::{BankError, BankInMessage as InMessage, BankOutMessage as OutMessage};
 
@@ -42,7 +45,7 @@ impl Bank {
 
 impl GenServer for Bank {
     type CallMsg = InMessage;
-    type CastMsg = ();
+    type CastMsg = Unused;
     type OutMsg = MsgResult;
     type Error = BankError;
     type State = BankState;
@@ -117,13 +120,4 @@ impl GenServer for Bank {
             Self::CallMsg::Stop => CallResponse::Stop(Ok(OutMessage::Stopped)),
         }
     }
-
-    async fn handle_cast(
-        &mut self,
-        _message: Self::CastMsg,
-        _handle: &BankHandle,
-        state: Self::State,
-    ) -> CastResponse<Self> {
-        CastResponse::NoReply(state)
-    }
 }
diff --git a/examples/bank_threads/src/server.rs b/examples/bank_threads/src/server.rs
@@ -1,6 +1,9 @@
 use std::collections::HashMap;
 
-use spawned_concurrency::threads::{CallResponse, CastResponse, GenServer, GenServerHandle};
+use spawned_concurrency::{
+    messages::Unused,
+    threads::{CallResponse, GenServer, GenServerHandle},
+};
 
 use crate::messages::{BankError, BankInMessage as InMessage, BankOutMessage as OutMessage};
 
@@ -38,7 +41,7 @@ impl Bank {
 
 impl GenServer for Bank {
     type CallMsg = InMessage;
-    type CastMsg = ();
+    type CastMsg = Unused;
     type OutMsg = MsgResult;
     type Error = BankError;
     type State = BankState;
@@ -113,13 +116,4 @@ impl GenServer for Bank {
             Self::CallMsg::Stop => CallResponse::Stop(Ok(OutMessage::Stopped)),
         }
     }
-
-    fn handle_cast(
-        &mut self,
-        _message: Self::CastMsg,
-        _handle: &BankHandle,
-        state: Self::State,
-    ) -> CastResponse<Self> {
-        CastResponse::NoReply(state)
-    }
 }
diff --git a/examples/name_server/src/server.rs b/examples/name_server/src/server.rs
@@ -1,6 +1,9 @@
 use std::collections::HashMap;
 
-use spawned_concurrency::tasks::{CallResponse, CastResponse, GenServer, GenServerHandle};
+use spawned_concurrency::{
+    messages::Unused,
+    tasks::{CallResponse, GenServer, GenServerHandle},
+};
 
 use crate::messages::{NameServerInMessage as InMessage, NameServerOutMessage as OutMessage};
 
@@ -27,7 +30,7 @@ impl NameServer {
 
 impl GenServer for NameServer {
     type CallMsg = InMessage;
-    type CastMsg = ();
+    type CastMsg = Unused;
     type OutMsg = OutMessage;
     type Error = std::fmt::Error;
     type State = NameServerState;
@@ -56,13 +59,4 @@ impl GenServer for NameServer {
             },
         }
     }
-
-    async fn handle_cast(
-        &mut self,
-        _message: Self::CastMsg,
-        _handle: &NameServerHandle,
-        state: Self::State,
-    ) -> CastResponse<Self> {
-        CastResponse::NoReply(state)
-    }
 }
diff --git a/examples/name_server_with_error/src/server.rs b/examples/name_server_with_error/src/server.rs
diff --git a/examples/updater/src/server.rs b/examples/updater/src/server.rs
diff --git a/examples/updater_threads/src/server.rs b/examples/updater_threads/src/server.rs

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,2 @@`
	`1`	`+#[derive(Clone)]`
	`2`	`+pub struct Unused;`