Split trait Sender into Sender + CloneSender

Signed-off-by: Didier Wenzek <didier.wenzek@free.fr>

Author: didier-wenzek

crates/core/tedge_actors/src/builders.rs

@@ -77,14 +77,14 @@
 //!   using an `impl From<SourceMessage> for SinkMessage`. This flexibility allows an actor to receive
 //!   messages from several independent sources (see the [fan_in_message_type](crate::fan_in_message_type) macro).
 use crate::mpsc;
+use crate::CloneSender;
 use crate::DynSender;
 use crate::LoggingReceiver;
 use crate::LoggingSender;
 use crate::MappingSender;
 use crate::Message;
 use crate::NullSender;
 use crate::RuntimeRequest;
-use crate::Sender;
 use crate::SimpleMessageBox;
 use std::convert::Infallible;
 use std::fmt::Debug;

crates/core/tedge_actors/src/channels.rs

@@ -7,21 +7,38 @@ use futures::SinkExt;
 
 /// A sender of messages of type `M`
 ///
-/// Actors don't access directly the `mpsc::Sender` of their peers,
+/// Actors don't get direct access to the `mpsc::Sender` of their peers,
 /// but use intermediate senders that adapt the messages when sent.
-pub type DynSender<M> = Box<dyn Sender<M>>;
+pub type DynSender<M> = Box<dyn CloneSender<M>>;
 
 #[async_trait]
 pub trait Sender<M>: 'static + Send + Sync {
     /// Send a message to the receiver behind this sender,
     /// returning an error if the receiver is no more expecting messages
     async fn send(&mut self, message: M) -> Result<(), ChannelError>;
+}
 
+pub trait CloneSender<M>: Sender<M> {
     /// Clone this sender in order to send messages to the same receiver from another actor
     fn sender_clone(&self) -> DynSender<M>;
+
+    /// Clone a cast of this sender into a `Box<dyn Sender<M>>`
+    ///
+    /// This is a workaround for https://github.com/rust-lang/rust/issues/65991
+    fn sender(&self) -> Box<dyn Sender<M>>;
+}
+
+impl<M, S: Clone + Sender<M>> CloneSender<M> for S {
+    fn sender_clone(&self) -> DynSender<M> {
+        Box::new(self.clone())
+    }
+
+    fn sender(&self) -> Box<dyn Sender<M>> {
+        Box::new(self.clone())
+    }
 }
 
-impl<M: Message> Clone for DynSender<M> {
+impl<M: 'static> Clone for DynSender<M> {
     fn clone(&self) -> Self {
         self.sender_clone()
     }
@@ -39,10 +56,6 @@ impl<M: Message, N: Message + Into<M>> Sender<N> for mpsc::Sender<M> {
     async fn send(&mut self, message: N) -> Result<(), ChannelError> {
         Ok(SinkExt::send(&mut self, message.into()).await?)
     }
-
-    fn sender_clone(&self) -> DynSender<N> {
-        Box::new(self.clone())
-    }
 }
 
 /// An `mpsc::UnboundedSender<M>` is a `DynSender<N>` provided `N` implements `Into<M>`
@@ -88,24 +101,17 @@ impl<M: Message, N: Message + Into<M>> Sender<N> for DynSender<M> {
     async fn send(&mut self, message: N) -> Result<(), ChannelError> {
         Ok(self.as_mut().send(message.into()).await?)
     }
-
-    fn sender_clone(&self) -> DynSender<N> {
-        Box::new(self.as_ref().sender_clone())
-    }
 }
 
 /// A sender that discards messages instead of sending them
+#[derive(Clone)]
 pub struct NullSender;
 
 #[async_trait]
 impl<M: Message> Sender<M> for NullSender {
     async fn send(&mut self, _message: M) -> Result<(), ChannelError> {
         Ok(())
     }
-
-    fn sender_clone(&self) -> DynSender<M> {
-        Box::new(NullSender)
-    }
 }
 
 impl<M: Message> From<NullSender> for DynSender<M> {
@@ -120,6 +126,15 @@ pub struct MappingSender<F, M> {
     cast: std::sync::Arc<F>,
 }
 
+impl<F, M: 'static> Clone for MappingSender<F, M> {
+    fn clone(&self) -> Self {
+        MappingSender {
+            inner: self.inner.clone(),
+            cast: self.cast.clone(),
+        }
+    }
+}
+
 impl<F, M> MappingSender<F, M> {
     pub fn new(inner: DynSender<M>, cast: F) -> Self {
         MappingSender {
@@ -144,13 +159,6 @@ where
         }
         Ok(())
     }
-
-    fn sender_clone(&self) -> DynSender<M> {
-        Box::new(MappingSender {
-            inner: self.inner.sender_clone(),
-            cast: self.cast.clone(),
-        })
-    }
 }
 
 impl<M, N, NS, F> From<MappingSender<F, N>> for DynSender<M>

crates/core/tedge_actors/src/message_boxes.rs

@@ -91,6 +91,7 @@
 //!
 use crate::channels::Sender;
 use crate::ChannelError;
+use crate::CloneSender;
 use crate::DynSender;
 use crate::Message;
 use crate::RuntimeRequest;
@@ -218,34 +219,27 @@ pub struct LoggingSender<Output> {
     sender: DynSender<Output>,
 }
 
-impl<Output> LoggingSender<Output> {
-    pub fn new(name: String, sender: DynSender<Output>) -> Self {
-        Self { name, sender }
-    }
-}
-
 impl<Output: 'static> Clone for LoggingSender<Output> {
     fn clone(&self) -> Self {
-        Self {
+        LoggingSender {
             name: self.name.clone(),
             sender: self.sender.sender_clone(),
         }
     }
 }
 
+impl<Output> LoggingSender<Output> {
+    pub fn new(name: String, sender: DynSender<Output>) -> Self {
+        Self { name, sender }
+    }
+}
+
 #[async_trait]
-impl<Output: Debug + Send + Sync + 'static> Sender<Output> for LoggingSender<Output> {
+impl<Output: Message + Debug> Sender<Output> for LoggingSender<Output> {
     async fn send(&mut self, message: Output) -> Result<(), ChannelError> {
         log_message_sent(&self.name, &message);
         self.sender.send(message).await
     }
-
-    fn sender_clone(&self) -> DynSender<Output> {
-        Box::new(LoggingSender {
-            name: self.name.clone(),
-            sender: self.sender.clone(),
-        })
-    }
 }
 
 pub fn log_message_sent<I: Debug>(target: &str, message: I) {
@@ -331,7 +325,7 @@ impl<Input: Send + Debug> MessageReceiver<Input> for UnboundedLoggingReceiver<In
 /// - Log sent messages when pushed into the target box
 ///
 /// Such a box is connected to peer actors using a [SimpleMessageBoxBuilder](crate::SimpleMessageBoxBuilder).
-pub struct SimpleMessageBox<Input: Debug, Output> {
+pub struct SimpleMessageBox<Input: Debug, Output: Debug> {
     input_receiver: LoggingReceiver<Input>,
     output_sender: LoggingSender<Output>,
 }
@@ -390,9 +384,15 @@ impl<Input: Message, Output: Message> Sender<Output> for SimpleMessageBox<Input,
     async fn send(&mut self, message: Output) -> Result<(), ChannelError> {
         self.output_sender.send(message).await
     }
+}
 
+impl<Input: Message, Output: Message> CloneSender<Output> for SimpleMessageBox<Input, Output> {
     fn sender_clone(&self) -> DynSender<Output> {
-        self.output_sender.sender_clone()
+        CloneSender::sender_clone(&self.output_sender)
+    }
+
+    fn sender(&self) -> Box<dyn Sender<Output>> {
+        CloneSender::sender(&self.output_sender)
     }
 }
 

crates/core/tedge_actors/src/servers/builders.rs

@@ -2,6 +2,7 @@ use crate::mpsc;
 use crate::Actor;
 use crate::Builder;
 use crate::ClientId;
+use crate::CloneSender;
 use crate::ConcurrentServerActor;
 use crate::ConcurrentServerMessageBox;
 use crate::DynSender;
@@ -13,7 +14,6 @@ use crate::NoConfig;
 use crate::RuntimeError;
 use crate::RuntimeRequest;
 use crate::RuntimeRequestSink;
-use crate::Sender;
 use crate::SenderVec;
 use crate::Server;
 use crate::ServerActor;

crates/core/tedge_actors/src/servers/keyed_messages.rs

@@ -6,11 +6,20 @@ use crate::Sender;
 use async_trait::async_trait;
 
 /// A sender that adds a key to messages on the fly
-pub struct KeyedSender<K: Message + Clone, M: Message> {
+pub struct KeyedSender<K, M> {
     key: K,
     sender: mpsc::Sender<(K, M)>,
 }
 
+impl<K: Clone, M> Clone for KeyedSender<K, M> {
+    fn clone(&self) -> Self {
+        KeyedSender {
+            key: self.key.clone(),
+            sender: self.sender.clone(),
+        }
+    }
+}
+
 impl<K: Message + Clone, M: Message> KeyedSender<K, M> {
     pub fn new_sender(key: K, sender: mpsc::Sender<(K, M)>) -> DynSender<M> {
         Box::new(KeyedSender { key, sender })
@@ -22,20 +31,21 @@ impl<K: Message + Clone, M: Message> Sender<M> for KeyedSender<K, M> {
     async fn send(&mut self, message: M) -> Result<(), ChannelError> {
         self.sender.send((self.key.clone(), message)).await
     }
-
-    fn sender_clone(&self) -> DynSender<M> {
-        Box::new(KeyedSender {
-            key: self.key.clone(),
-            sender: self.sender.clone(),
-        })
-    }
 }
 
 /// A vector of senders addressed using a sender id attached to each message
-pub struct SenderVec<M: Message> {
+pub struct SenderVec<M> {
     senders: Vec<DynSender<M>>,
 }
 
+impl<M: 'static> Clone for SenderVec<M> {
+    fn clone(&self) -> Self {
+        SenderVec {
+            senders: self.senders.clone(),
+        }
+    }
+}
+
 impl<M: Message> SenderVec<M> {
     pub fn new_sender(senders: Vec<DynSender<M>>) -> DynSender<(usize, M)> {
         Box::new(SenderVec { senders })
@@ -51,9 +61,4 @@ impl<M: Message> Sender<(usize, M)> for SenderVec<M> {
         }
         Ok(())
     }
-
-    fn sender_clone(&self) -> DynSender<(usize, M)> {
-        let senders = self.senders.iter().map(|r| r.sender_clone()).collect();
-        Box::new(SenderVec { senders })
-    }
 }

crates/core/tedge_actors/src/servers/message_boxes.rs

@@ -22,7 +22,7 @@ pub type ServerMessageBox<Request, Response> =
 pub type ClientId = usize;
 
 /// A message box for services that handles requests concurrently
-pub struct ConcurrentServerMessageBox<Request: Debug, Response> {
+pub struct ConcurrentServerMessageBox<Request: Debug, Response: Debug> {
     /// Max concurrent requests
     max_concurrency: usize,
 
@@ -119,7 +119,7 @@ impl<Request: Message, Response: Message> ConcurrentServerMessageBox<Request, Re
 /// and synchronously wait for its response using the `await_response` function.
 ///
 /// Note that this message box sends requests and receive responses.
-pub struct ClientMessageBox<Request, Response: Debug> {
+pub struct ClientMessageBox<Request: Message, Response: Message + Debug> {
     messages: SimpleMessageBox<Response, Request>,
 }
 

crates/core/tedge_actors/src/test_helpers.rs

@@ -318,6 +318,15 @@ pub struct TimedMessageBox<T> {
     inner: T,
 }
 
+impl<T: Clone> Clone for TimedMessageBox<T> {
+    fn clone(&self) -> Self {
+        TimedMessageBox {
+            timeout: self.timeout,
+            inner: self.inner.clone(),
+        }
+    }
+}
+
 #[async_trait]
 impl<T, M> MessageReceiver<M> for TimedMessageBox<T>
 where
@@ -358,10 +367,6 @@ where
     async fn send(&mut self, message: M) -> Result<(), ChannelError> {
         self.inner.send(message).await
     }
-
-    fn sender_clone(&self) -> DynSender<M> {
-        self.inner.sender_clone()
-    }
 }
 
 impl<T> AsRef<T> for TimedMessageBox<T> {

crates/extensions/c8y_mapper_ext/src/converter.rs

@@ -1613,6 +1613,7 @@ pub(crate) mod tests {
     use serde_json::Value;
     use std::str::FromStr;
     use tedge_actors::Builder;
+    use tedge_actors::CloneSender;
     use tedge_actors::LoggingSender;
     use tedge_actors::MessageReceiver;
     use tedge_actors::Sender;

crates/extensions/tedge_timer_ext/src/builder.rs

@@ -72,6 +72,14 @@ struct TimeoutSender<T: Message> {
     inner: DynSender<Timeout<T>>,
 }
 
+impl<T: Message> Clone for TimeoutSender<T> {
+    fn clone(&self) -> Self {
+        TimeoutSender {
+            inner: self.inner.clone(),
+        }
+    }
+}
+
 #[async_trait]
 impl<T: Message> Sender<Timeout<AnyPayload>> for TimeoutSender<T> {
     async fn send(&mut self, message: Timeout<AnyPayload>) -> Result<(), ChannelError> {
@@ -80,18 +88,13 @@ impl<T: Message> Sender<Timeout<AnyPayload>> for TimeoutSender<T> {
         }
         Ok(())
     }
-
-    fn sender_clone(&self) -> DynSender<Timeout<AnyPayload>> {
-        Box::new(TimeoutSender {
-            inner: self.inner.sender_clone(),
-        })
-    }
 }
 
 /// A Sender that translates timeout requests on the wire
 ///
 /// This sender receives `SetTimeout<T>` requests from some actor,
 /// and translates then forwards these messages to the timer actor expecting`Timeout<AnyPayload>`
+#[derive(Clone)]
 struct SetTimeoutSender {
     inner: DynSender<SetTimeout<AnyPayload>>,
 }
@@ -103,10 +106,4 @@ impl<T: Message> Sender<SetTimeout<T>> for SetTimeoutSender {
         let event: AnyPayload = Box::new(request.event);
         self.inner.send(SetTimeout { duration, event }).await
     }
-
-    fn sender_clone(&self) -> DynSender<SetTimeout<T>> {
-        Box::new(SetTimeoutSender {
-            inner: self.inner.sender_clone(),
-        })
-    }
 }