Make clone_unchecked return a Result (#4819)

## Motivation

Remove the potential panic in reentrant_collection_view.rs

## Proposal

* Make clone_unchecked return a Result
* Remove dead code

## Test Plan

CI

## Release Plan

- These changes should be backported to the latest `devnet` branch

Author: ma2bd

linera-core/src/chain_worker/state.rs

@@ -248,7 +248,7 @@ where
         &mut self,
     ) -> Result<OwnedRwLockReadGuard<ChainStateView<StorageClient::Context>>, WorkerError> {
         if self.shared_chain_view.is_none() {
-            self.shared_chain_view = Some(Arc::new(RwLock::new(self.chain.clone_unchecked())));
+            self.shared_chain_view = Some(Arc::new(RwLock::new(self.chain.clone_unchecked()?)));
         }
 
         Ok(self

linera-service/src/exporter/runloops/block_processor/mod.rs

@@ -192,7 +192,7 @@ mod test {
             NodeOptions::default(),
             0,
             signal.clone(),
-            exporter_storage.clone(),
+            exporter_storage.clone()?,
             vec![],
         );
         let mut block_processor = BlockProcessor::new(
@@ -328,7 +328,7 @@ mod test {
             NodeOptions::default(),
             0,
             signal.clone(),
-            exporter_storage.clone(),
+            exporter_storage.clone()?,
             vec![],
         );
         let mut block_processor = BlockProcessor::new(
@@ -444,7 +444,7 @@ mod test {
             NodeOptions::default(),
             0,
             signal.clone(),
-            exporter_storage.clone(),
+            exporter_storage.clone()?,
             vec![],
         );
         let mut block_processor = BlockProcessor::new(
@@ -531,7 +531,7 @@ mod test {
             NodeOptions::default(),
             0,
             signal.clone(),
-            exporter_storage.clone(),
+            exporter_storage.clone()?,
             vec![],
         );
         let mut block_processor = BlockProcessor::new(
@@ -640,7 +640,7 @@ mod test {
             NodeOptions::default(),
             0,
             signal.clone(),
-            exporter_storage.clone(),
+            exporter_storage.clone()?,
             vec![],
         );
         let mut block_processor = BlockProcessor::new(

linera-service/src/exporter/runloops/indexer/indexer_exporter.rs

@@ -68,7 +68,7 @@ impl Exporter {
                 self.work_queue_size,
                 destination_state.load(Ordering::Acquire) as usize,
                 outgoing_stream,
-                storage.clone(),
+                storage.clone()?,
             );
 
             let mut acknowledgement_task =

linera-service/src/exporter/runloops/mod.rs

@@ -107,7 +107,7 @@ where
         options,
         limits.work_queue_size.into(),
         shutdown_signal.clone(),
-        exporter_storage.clone(),
+        exporter_storage.clone()?,
         destination_config.destinations.clone(),
     );
 

linera-service/src/exporter/runloops/task_manager.rs

@@ -112,7 +112,8 @@ where
 
     fn spawn(&mut self, id: DestinationId) {
         let exporter_builder = &self.exporters_builder;
-        let join_handle = exporter_builder.spawn(id.clone(), self.storage.clone());
+        let storage = self.storage.clone().expect("Failed to clone storage");
+        let join_handle = exporter_builder.spawn(id.clone(), storage);
         self.join_handles.insert(id, join_handle);
     }
 }

linera-service/src/exporter/runloops/validator_exporter.rs

@@ -62,10 +62,10 @@ impl Exporter {
         let (mut task_queue, task_receiver) = TaskQueue::new(
             self.work_queue_size,
             destination_state.load(Ordering::Acquire) as usize,
-            storage.clone(),
+            storage.clone()?,
         );
 
-        let export_task = ExportTask::new(node, storage.clone(), destination_state);
+        let export_task = ExportTask::new(node, storage.clone()?, destination_state);
 
         tokio::select! {
 

linera-service/src/exporter/state.rs

@@ -68,7 +68,7 @@ where
         );
 
         let states = view.destination_states.get().clone();
-        let canonical_state = view.canonical_state.clone_unchecked();
+        let canonical_state = view.canonical_state.clone_unchecked()?;
 
         Ok((view, canonical_state, states))
     }

linera-service/src/exporter/storage.rs

@@ -142,14 +142,14 @@ where
         self.shared_canonical_state.push(block)
     }
 
-    fn clone(&mut self) -> Self {
-        Self {
+    fn clone(&mut self) -> Result<Self, ExporterError> {
+        Ok(Self {
             storage: self.storage.clone(),
-            shared_canonical_state: self.shared_canonical_state.clone(),
+            shared_canonical_state: self.shared_canonical_state.clone()?,
             blobs_cache: self.blobs_cache.clone(),
             blocks_cache: self.blocks_cache.clone(),
             destination_states: self.destination_states.clone(),
-        }
+        })
     }
 }
 
@@ -202,8 +202,8 @@ where
         self.shared_storage.destination_states.load_state(id)
     }
 
-    pub(crate) fn clone(&mut self) -> Self {
-        ExporterStorage::new(self.shared_storage.clone())
+    pub(crate) fn clone(&mut self) -> Result<Self, ExporterError> {
+        Ok(ExporterStorage::new(self.shared_storage.clone()?))
     }
 
     pub(crate) fn get_latest_index(&self) -> usize {
@@ -240,7 +240,7 @@ where
 
         let mut shared_storage =
             SharedStorage::new(storage, canonical_state, destination_states, limits);
-        let exporter_storage = ExporterStorage::new(shared_storage.clone());
+        let exporter_storage = ExporterStorage::new(shared_storage.clone()?);
 
         Ok((
             Self {
@@ -422,13 +422,13 @@ where
         }
     }
 
-    fn clone(&mut self) -> Self {
-        Self {
+    fn clone(&mut self) -> Result<Self, ExporterError> {
+        Ok(Self {
             count: self.count,
             state_cache: self.state_cache.clone(),
             state_updates_buffer: self.state_updates_buffer.clone(),
-            state_context: self.state_context.clone_unchecked(),
-        }
+            state_context: self.state_context.clone_unchecked()?,
+        })
     }
 
     /// Returns the latest index of the canonical state.

linera-service/src/proxy/grpc.rs

@@ -369,9 +369,9 @@ where
             ViewError::KeyTooLong | ViewError::ArithmeticError(_) => {
                 Status::out_of_range(err.to_string())
             }
-            ViewError::NotFound(_)
-            | ViewError::CannotAcquireCollectionEntry
-            | ViewError::MissingEntries => Status::not_found(err.to_string()),
+            ViewError::NotFound(_) | ViewError::MissingEntries => {
+                Status::not_found(err.to_string())
+            }
         };
         status.set_source(Arc::new(err));
         status

linera-views-derive/src/lib.rs

@@ -380,7 +380,7 @@ fn generate_clonable_view_code(input: ItemStruct) -> Result<TokenStream2, Error>
         let name = &field.ident;
         let ty = &field.ty;
         clone_constraints.push(quote! { #ty: ClonableView });
-        clone_fields.push(quote! { #name: self.#name.clone_unchecked() });
+        clone_fields.push(quote! { #name: self.#name.clone_unchecked()? });
     }
 
     Ok(quote! {
@@ -390,10 +390,10 @@ fn generate_clonable_view_code(input: ItemStruct) -> Result<TokenStream2, Error>
             #(#clone_constraints,)*
             Self: linera_views::views::View,
         {
-            fn clone_unchecked(&mut self) -> Self {
-                Self {
+            fn clone_unchecked(&mut self) -> Result<Self, linera_views::ViewError> {
+                Ok(Self {
                     #(#clone_fields,)*
-                }
+                })
             }
         }
     })